[Federal Register Volume 76, Number 60 (Tuesday, March 29, 2011)]
[Rules and Regulations]
[Pages 17488-17520]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2011-6268]
[[Page 17487]]
Vol. 76
Tuesday,
No. 60
March 29, 2011
Part II
Environmental Protection Agency
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40 CFR Part 82
Protection of Stratospheric Ozone: New Substitute in the Motor Vehicle
Air Conditioning Sector Under the Significant New Alternatives Policy
(SNAP) Program; Final Rule
Federal Register / Vol. 76, No. 60 / Tuesday, March 29, 2011 / Rules
and Regulations
[[Page 17488]]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 82
[EPA-HQ-OAR-2008-0664; FRL-9275-8]
RIN 2060-AP11
Protection of Stratospheric Ozone: New Substitute in the Motor
Vehicle Air Conditioning Sector Under the Significant New Alternatives
Policy (SNAP) Program
AGENCY: Environmental Protection Agency (EPA).
ACTION: Final rule.
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SUMMARY: The Environmental Protection Agency's (EPA) Significant New
Alternatives Policy (SNAP) program is expanding the list of acceptable
substitutes for use in the motor vehicle air conditioning end-use as a
replacement for ozone-depleting substances. The Clean Air Act requires
EPA to review alternatives for ozone-depleting substances and to
disapprove substitutes that present overall risks to human health and
the environment more significant than those presented by other
alternatives that are available or potentially available. The
substitute addressed in this final rule is for use in new passenger
cars and light-duty trucks in the motor vehicle air conditioning end-
use within the refrigeration and air conditioning sector. EPA finds
hydrofluoroolefin (HFO)-1234yf acceptable, subject to use conditions,
as a substitute for chlorofluorocarbon (CFC)-12 in motor vehicle air
conditioning for new passenger cars and light-duty trucks. The
substitute is a non-ozone-depleting gas and consequently does not
contribute to stratospheric ozone depletion.
DATES: This final rule is effective on May 31, 2011. The incorporation
by reference of certain publications listed in the rule is approved by
the Director of the Federal Register as of May 31, 2011.
ADDRESSES: EPA has established a docket for this action under Docket ID
No. EPA-HQ-OAR-2008-0664. All documents in the docket are listed on the
http://www.regulations.gov Web site. Although listed in the index, some
information is not publicly available, e.g., confidential business
information (CBI) or other information whose disclosure is restricted
by statute. Certain other material, such as copyrighted material, is
not placed on the Internet and will be publicly available only in hard
copy form. Publicly available docket materials are available either
electronically through http://www.regulations.gov or in hard copy at
the Air Docket, EPA/DC, EPA West, Room 3334, 1301 Constitution Ave.,
NW., Washington, DC. This Docket Facility is open from 8:30 a.m. to
4:30 p.m., Monday through Friday, excluding legal holidays. The
telephone number for the Public Reading Room is (202) 566-1744, and the
telephone number for the Air Docket is (202) 566-1742.
FOR FURTHER INFORMATION CONTACT: Margaret Sheppard, Stratospheric
Protection Division, Office of Atmospheric Programs; Environmental
Protection Agency, Mail Code 6205J, 1200 Pennsylvania Avenue, NW.,
Washington, DC 20460; telephone number (202) 343-9163, fax number,
(202) 343-2338; e-mail address at [email protected].
Notices and rulemakings under the SNAP program are available on
EPA's Stratospheric Ozone Web site at http://www.epa.gov/ozone/snap/regulations.html. The full list of SNAP decisions in all industrial
sectors is available at http://www.epa.gov/ozone/snap.
SUPPLEMENTARY INFORMATION: This final rule provides motor vehicle
manufacturers and their suppliers an additional refrigerant option for
motor vehicle air conditioning (MVAC) systems in new passenger cars and
light-duty trucks. HFO-1234yf (2,3,3,3-tetrafluoroprop-1-ene), the
refrigerant discussed in this final action, is a non-ozone-depleting
substance.
Table of Contents
I. Does this action apply to me?
II. What abbreviations and acronyms are used in this action?
III. What is EPA's final decision for HFO-1234yf for motor vehicle
air conditioning (MVAC)?
IV. What are the final use conditions and why did EPA finalize these
conditions?
V. Why is EPA finding HFO-1234yf acceptable subject to use
conditions?
VI. What is the relationship between this SNAP rule and other EPA
rules?
A. Significant New Use Rule
B. Rules Under Sections 609 and 608 of the Clean Air Act
VII. What is EPA's response to public comments on the proposal?
A. Acceptability Decision
B. Use Conditions
C. Environmental Impacts
D. Health and Safety Impacts
E. Retrofit Usage
F. Use by ``Do-It-Yourselfers''
G. Servicing Issues
H. Cost, Availability, and Small Business Impacts
VIII. How does the SNAP program work?
A. What are the statutory requirements and authority for the
SNAP program?
B. What are EPA's regulations implementing section 612?
C. How do the regulations for the SNAP program work?
D. Where can I get additional information about the SNAP
program?
IX. Statutory and Executive Order Reviews
A. Executive Order 12866: Regulatory Planning and Review
B. Paperwork Reduction Act
C. Regulatory Flexibility Act
D. Unfunded Mandates Reform Act
E. Executive Order 13132: Federalism
F. Executive Order 13175: Consultation and Coordination With
Indian Tribal Governments
G. Executive Order 13045: Protection of Children From
Environmental Health and Safety Risks
H. Executive Order 13211: Actions That Significantly Affect
Energy Supply, Distribution, or Use
I. National Technology Transfer and Advancement Act
J. Executive Order 12898: Federal Actions To Address
Environmental Justice in Minority Populations and Low-Income
Populations
K. Congressional Review Act
X. References
I. Does this action apply to me?
This final rule regulates the use of the chemical HFO-1234yf
(2,3,3,3-tetrafluoroprop-1-ene, Chemical Abstracts Service Registry
Number [CAS Reg. No.] 754-12-1) as a refrigerant in new motor vehicle
air conditioning (MVAC) systems in new passenger cars and light-duty
trucks. Businesses in this end-use that might want to use HFO-1234yf in
new MVAC systems in the future include:
Automobile manufacturers.
Manufacturers of motor vehicle air conditioners.
Regulated entities may include:
Table 1--Potentially Regulated Entities, by North American Industrial
Classification System (NAICS) Code
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Description of
Category NAICS code regulated entities
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Industry...................... 336111 Automobile
Manufacturing.
Industry...................... 336391 Motor Vehicle Air-
Conditioning
Manufacturing.
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[[Page 17489]]
This table is not intended to be exhaustive, but rather a guide
regarding entities likely to be regulated by this action. If you have
any questions about whether this action applies to a particular entity,
consult the person listed in the preceding section, FOR FURTHER
INFORMATION CONTACT.
II. What abbreviations and acronyms are used in this action?
100-yr--one-hundred year time horizon
AEGL--Acute Exposure Guideline Level
AIST--the National Institute for Advanced Industrial Science and
Technology of Japan
ASHRAE--American Society for Heating, Refrigerating, and Air-
Conditioning Engineers
ATSDR--the U.S. Agency for Toxic Substances and Disease Registry
BAM--Bundesanstalt f[uuml]r Materialforschung und-pr[uuml]fung
(German Federal Institute for Materials Research and Testing)
CAA--Clean Air Act
CAS Reg. No.--Chemical Abstracts Service Registry Number
CBI--Confidential Business Information
CFC--chlorofluorocarbon
CFC-12--the ozone-depleting chemical dichlorodifluoromethane, CAS
Reg. No. 75-71-8
CFD--Computational Fluid Dynamics
CFR--Code of Federal Regulations
cm/s--centimeters per second
CO2--carbon dioxide, CAS Reg. No. 124-38-9
CRP--Cooperative Research Program
DIN--Deutsches Institut f[uuml]r Normung (designation for standards
from the German Institute for Standards)
DIY--``do-it-yourself''
DOT--the United States Department of Transportation
EPA--the United States Environmental Protection Agency
EO--Executive Order
FMEA--Failure Mode and Effect Analysis
FR--Federal Register
GWP--Global Warming Potential
HF--Hydrogen Fluoride, CAS Reg. No. 7664-39-3
HI--Hazard Index
HFC--hydrofluorocarbon
HFC-134a--the chemical 1,1,1,2-tetrafluoroethane, CAS Reg. No. 811-
97-2
HFC-152a--the chemical 1,1-difluoroethane, CAS Reg. No. 75-37-6
HFO--hydrofluoroolefin
HFO-1234yf--the chemical 2,3,3,3-tetrafluoroprop-1-ene, CAS Reg. No.
754-12-1
ISO--International Organization for Standardization
JAMA--Japan Automobile Manufacturers Association
JAPIA--Japan Auto Parts Industries Association
LCA--Lifecycle Analysis
LCCP--Lifecycle Climate Performance
LFL--Lower Flammability Limit
LOAEL--Lowest Observed Adverse Effect Level
mg/L--milligram per liter
MIR--Maximum Incremental Reactivity
mJ--millijoule
mm--millimeter
MOE--Margin of Exposure
MPa--megapascal
MRL--Minimal Risk Level
MVAC--Motor Vehicle Air Conditioning
NAICS--North American Industrial Classification System
ng/L--nanograms per liter
NHTSA--the U.S. National Highway Traffic Safety Administration
NOAEL--No Observed Adverse Effect Level
NOEC--No Observed Effect Concentration
NPRM--Notice of Proposed Rulemaking
NTTAA--National Technology Transfer and Advancement Act
ODP--Ozone Depletion Potential
ODS--zmOzone-Depleting Substance
OEM--Original Equipment Manufacturer
OMB--Office of Management and Budget
OSHA--the United States Occupational Safety and Health
Administration
PAG--Polyalkylene Glycol
PMN--Pre-Manufacture Notice
POCP--Photochemical Ozone Creation Potential
POD--Point of Departure
ppm--parts per million
ppt--parts per trillion
psig--pounds per square inch gauge
R-1234yf--ASHRAE designation for refrigerant HFO-1234yf
R-134a--ASHRAE designation for refrigerant HFC-134a
R-152a--ASHRAE designation for refrigerant HFC-152a
R-744--ASHRAE designation for refrigerant CO2
RCRA--the Resource Conservation and Recovery Act
RFA--Regulatory Flexibility Act
SAE--SAE International, formerly the Society of Automotive Engineers
SBA--the United States Small Business Administration
SIP--State Implementation Plan
SNAP--Significant New Alternatives Policy
SNUN--Significant New Use Notice
SNUR--Significant New Use Rule
SO2--sulfur dioxide, CAS Reg. No. 7446-09-5
TEWI--Total Equivalent Warming Impact
TFA--Trifluoroacetic acid, CF3COOH, also known as
trifluoroethanoic acid, CAS Reg. No. 76-05-1
TSCA--the Toxic Substances Control Act
TWA--Time-Weighted Average
UBA--Umweltbundesamt (German Federal Environment Agency)
UF--Uncertainty Factor
UMRA--Unfunded Mandates Reform Act
VDA--Verband der Automobilindustrie (German Association for the
Automobile Industry)
VOC--Volatile Organic Compound
v/v--volume to volume
WEEL--Workplace Environmental Exposure Limit
III. What is EPA's final decision for HFO-1234yf for motor vehicle air
conditioning (MVAC)?
In this final rule, EPA is finding HFO-1234yf acceptable, subject
to use conditions, as a substitute for CFC-12 in new MVAC systems for
passenger cars and light-duty trucks. This determination does not apply
to the use of HFO-1234yf as a conversion or retrofit for existing MVAC
systems. In addition, it does not apply to the use of HFO-1234yf in the
air conditioning or refrigeration systems of heavy-duty trucks,
refrigerated transport, or off-road vehicles such as agricultural or
construction equipment.
EPA is not mandating the use of HFO-1234yf or any other alternative
for MVAC systems. This final rule is adding HFO-1234yf to the list of
acceptable substitutes, subject to use conditions, in new MVAC systems.
Automobile manufacturers have the option of using any refrigerant
listed as acceptable for this end-use, so long as they meet any
applicable use conditions.
Under this decision, the following enforceable use conditions apply
when HFO-1234yf is used in a new MVAC system for passenger cars and
light-duty trucks:
1. HFO-1234yf MVAC systems must adhere to all of the safety
requirements of SAE \1\ J639 (adopted 2011), including requirements for
a flammable refrigerant warning label, high-pressure compressor cutoff
switch and pressure relief devices, and unique fittings. For
connections with refrigerant containers of 20 lbs or greater, use
fittings consistent with SAE J2844 (adopted 2011).
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\1\ Designates a standard from SAE International, formerly the
Society of Automotive Engineers.
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2. Manufacturers must conduct Failure Mode and Effect Analysis
(FMEA) as provided in SAE J1739 (adopted 2009). Manufacturers must keep
the FMEA on file for at least three years from the date of creation.
IV. What are the final use conditions and why did EPA finalize these
conditions?
Summary of the Use Conditions
The first use condition requires that MVAC systems designed to use
HFO-1234yf must meet the requirements of the 2011 version of the
industry standard SAE J639, ``Safety Standards for Motor Vehicle
Refrigerant Vapor Compression Systems.'' Among other things, this
standard sets safety standards that include unique fittings to connect
refrigerant containers to the MVAC system; a warning label indicating
the refrigerant's identity and indicating that it is a flammable
refrigerant; and requirements for engineering design strategies that
include a high-pressure compressor cutoff switch and pressure relief
devices. This use condition also requires that fittings for refrigerant
[[Page 17490]]
containers of 20 lbs or greater will be consistent with SAE J2844 (same
fittings as for low-side service port in SAE J639).
The second use condition requires the manufacturer of MVAC systems
and vehicles (i.e., the original equipment manufacturer [OEM]) to
conduct and keep records of a risk assessment and failure Failure Mode
and Effects Analysis (FMEA) for at least three years from the date of
creation. There is an existing industry standard, SAE J1739, that gives
guidance on how to do this. It is standard industry practice to perform
the FMEA and to keep it on file while the vehicle is in production and
for several years afterwards (U.S. EPA, 2010a).
Reasons for Revised Use Conditions
EPA proposed five use conditions in the Notice of Proposed
Rulemaking (NPRM) (October 19, 2009; 74 FR 53445). One use condition
required manufacturers to meet all the safety requirements in the
standard SAE J639, ``Safety Standards for Motor Vehicle Refrigerant
Vapor Compression Systems'' and required use of unique servicing
fittings from that standard. Another use condition required automobile
manufacturers to perform Failure Mode and Effect Analysis (FMEA) and to
keep records of the FMEA.
The remaining three proposed use conditions specifically addressed
risks of flammability of HFO-1234yf and indirectly addressed risks of
generating hydrogen fluoride (HF) from combustion of HFO-1234yf. For
the first of those proposed use conditions, which addressed the
passenger compartment, the concentration of HFO-1234yf was not to
exceed the lower flammability limit (LFL) in the free space for more
than 15 seconds. For the second proposed use condition, which addressed
the engine compartment, the concentration of HFO-1234yf was not to
exceed the LFL for any period of time. A third proposed use condition,
which also addressed the engine compartment, would have required
protective devices, isolation and/or ventilation techniques in areas
where there is a potential to generate HFO-1234yf concentrations at or
above 6.2% volume to volume (v/v) in proximity to exhaust manifold
surfaces and hybrid or electric vehicle electric power sources.
EPA based our determination of the appropriate use conditions to
include in the final rule using information in the docket at the time
of proposal, comments received on the proposed rule, and additional
information we have received since the NPRM was published. We provided
additional opportunities for comment on the public comments and
additional information we received with them when we re-opened the
comment period on the proposed rule (74 FR 68558, December 28, 2009; 75
FR 6338, February 9, 2010). First, SAE International's Cooperative
Research Program (hereafter called the SAE CRP) issued a new report on
December 17, 2009 assessing risks of HFO-1234yf and carbon dioxide
(CO2) as refrigerants for MVAC. This report found that the
risks of HFO-1234yf were low overall, and somewhat less than risks for
another potential alternative refrigerant (CO2, also know as
R-744). The December 2009 CRP report found that the greatest risks from
HFO-1234yf are likely to come from generation of HF, both from thermal
decomposition and from ignition, rather than direct fire risks from
ignition of HFO-1234yf (EPA-HQ-OAR-2006-0664-0056.2). (HF is a severe
irritant to the skin, eyes, and respiratory system.) The SAE CRP
estimates risks of excessive HF exposure at approximately 4.6 x
10-12 occurrences per vehicle operating hour and risks of
ignition at approximately 9 x 10-14 occurrences per vehicle
operating hour. These correspond roughly to one occurrence in the
entire U.S. fleet of passenger vehicles over 2 years for HF risks and
one occurrence in the U.S. vehicle fleet every 100 years for
flammability risks.\2\ For comparison, the risk for excessive HF
exposure is less than one ten-thousandth the risk of a highway vehicle
fire and one fortieth or less of the risk of a fatality from deployment
of an airbag during a vehicle collision (EPA-HQ-OAR-2008-0664-0056.2).
Even these estimates may be conservative because they assume that
refrigerant could be released in a collision severe enough to rupture
the evaporator (under the windshield) while the windshield and windows
would remain intact and would prevent ventilation into the passenger
cabin in case of a collision (EPA-HQ-OAR-2006-0664-0056.2).
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\2\ Assumes a fleet of approximately 250 million passenger
vehicles and typical vehicle operation of 500 hours per year.
Sources: U.S. Census, http://www.census.gov/compendia/statab/2010/tables/10s1060.pdf; SAE J2766, as cited in EPA-HQ-OAR-2008-0664-
0056.2.
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Second, we received a number of public comments regarding the
proposed use conditions. Some commenters claimed that the second use
condition concerning concentrations in the engine compartment was
infeasible because in the event of a leak, there would always be some
small volume that would have a concentration over the LFL; these
commenters further stated that exceeding the LFL would not necessarily
create a risk of ignition, because one could have a leak that is not
near a source of heat or flame (EPA-HQ-OAR-2006-0664-0116.2; EPA-HQ-
OAR-2006-0664-0060). Some commenters stated that flammability was not a
significant risk from use of HFO-1234yf, given the results of the SAE
CRP risk assessment (December 17, 2009). These commenters stated that
the use conditions limiting refrigerant concentrations were not
necessary. These commenters also suggested a number of alternative ways
of phrasing the use conditions in order to address risks from HF as
well as flammability. Most of these comments suggested relying on the
performance of a risk assessment and Failure Mode and Effect Analysis
(FMEA) consistent with SAE J1739 to determine appropriate protective
strategies. Other commenters stated that the use conditions were not
sufficiently protective as proposed because of other risks: (1) Risks
due to generation of HF from HFO-1234yf, both from thermal
decomposition and from combustion; (2) risks from direct toxicity of
HFO-1234yf; and (3) risks from flammability of HFO-1234yf because the
LFL becomes lower than 6.2% at temperatures higher than 21 [deg]C (EPA-
HQ-OAR-2006-0664-0088, -0054, -0089, -0097 and -0057).
After evaluating the comments and the additional information made
available to the public through the re-opened comment period, we have
decided not to include the three use conditions that directly address
flammability in the final rule. We believe these use conditions are not
necessary to ensure that overall risks to human health and the
environment from HFO-1234yf will be similar to or less than those of
other available or potentially available refrigerants that EPA has
already listed or proposed as acceptable for MVAC. This is because of
the low overall levels of risk identified for HFO-1234yf from
flammability and from ignition of HF (EPA-HQ-OAR-2008-0664-0056.2). The
highest risk identified for HFO-1234yf is potential consumer exposure
to HF from decomposition and ignition, which is of the same order of
magnitude of risks of HF from the current most common automotive
refrigerant, hydrofluorocarbon (HFC)-134a\3\ (order of magnitude of
10-12 events per vehicle operating hour). EPA previously
[[Page 17491]]
found HFC-134a acceptable for use in new and retrofit MVAC systems (59
FR 13044; March 18, 1994; and 60 FR 31092, June 13, 1995), without use
conditions addressing risks of HF. Since that time, EPA has heard of no
cases where someone has been injured due to exposure to HF from
decomposition of HFC-134a from an MVAC system, and a risk assessment
from the SAE CRP found no published reports in the medical literature
of injuries to fire fighters or vehicle passengers from HF or other
decomposition products of HFC-134a (EPA-HQ-OAR-2008-0664-0008). The
direct risk of flammability from HFO-1234yf is extremely small.
Further, the risks of HFO-1234yf are comparable to or less than the
risks from other available or potentially available alternatives in
this end-use that EPA has already listed or proposed as acceptable
(e.g., HFC-152a,\4\ HFC-134a, and CO2) (EPA-HQ-OAR-2008-
0664-0086.1).
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\3\ HFC-134a is also known as 1,1,1,2-tetrafluoroethane or, when
used as a refrigerant, R-134a. The Chemical Abstracts Service
Registry Number (CAS Reg. No.) is 811-97-2.
\4\ HFC-152a is also known as 1,1-difluoroethane or, when used
as a refrigerant, R-152a. The CAS Reg. No. is 75-37-6.
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We have concluded that the use conditions we are including in the
final rule address the risks from both HF and flammability. Industry
standard SAE J639 (adopted 2011) provides for a pressure relief device
designed to minimize direct impingement of the refrigerant and oil on
hot surfaces and for design of the refrigerant circuit and connections
to avoid refrigerant entering the passenger cabin. These conditions
will mitigate risks of HF generation and ignition. The pressure release
device ensures that pressure in the system will not reach an unsafe
level that might cause an uncontrolled, explosive leak of refrigerant,
such as if the air conditioning system is overcharged. The pressure
release device will reduce the likelihood that refrigerant leaks would
reach hot surfaces that might lead to either ignition or formation of
HF. Designing the refrigerant circuit and connections to avoid
refrigerant entering the passenger cabin ensures that if there is a
leak, the refrigerant is unlikely to enter the passenger cabin. Keeping
refrigerant out of the passenger cabin minimizes the possibility that
there would be sufficient levels of refrigerant to reach flammable
concentrations or that HF would be formed and transported where
passengers might be exposed.
The last proposed use condition, requiring manufacturers to conduct
and keep records of FMEA according to the standard SAE J1739, remains
unchanged.
The proposed use condition regarding conducting and keeping records
of a Failure Mode and Effects Analysis according to the standard SAE
J1739 remains unchanged. We have revised the remaining proposed use
condition by replacing the reference to SAE J639 (adopted 2009) with a
reference to the 2011 version of the standard and to the fittings for
large refrigerant containers in SAE J2844 (2011). This is the most
recent version of the SAE J639 standard, with new provisions designed
specifically to address use of HFO-1234yf.
V. Why is EPA finding HFO-1234yf acceptable subject to use conditions?
EPA is finding HFO-1234yf acceptable subject to use conditions
because the use conditions are necessary to ensure that use of HFO-
1234yf will not have a significantly greater overall impact on human
health and the environment than other available or potentially
available substitutes for CFC-12 in MVAC systems. Examples of other
substitutes that EPA has already found acceptable subject to use
conditions for use in MVAC include HFC-134a and HFC-152a. HFC-134a is
the alternative most widely used in MVAC systems today. EPA has also
proposed to find CO2 (R-744) acceptable subject to use
conditions in MVAC (September 14, 2006; 71 FR 55140).
All alternatives listed as acceptable for use in MVAC systems in
passenger cars and light-duty trucks are required to have unique
fittings under use conditions issued previously under the SNAP Program
at appendix D to subpart G of 40 CFR part 82 (61 FR 54040, October 16,
1996). Thus, all substitutes for use in MVAC systems in passenger cars
and light-duty trucks are subject to those use conditions, at a
minimum, if found acceptable and thus are identified as acceptable
subject to use conditions. For HFO-1234yf, the unique fittings that
must be used for MVAC systems are those required in the industry
standard SAE J639 (2011). The fitting for refrigerant containers of 20
lbs or larger is specified in SAE J2844 (2011). The original submitter
of HFO-1234yf to the SNAP program has provided EPA with a copy of and a
diagram for these unique fittings. As described above, the fittings
will be quick-connect fittings, different from those for any other
refrigerant. The low-side service port and connections with containers
of 20 lbs or greater will have an outside diameter of 14 mm (0.551
inches) and the high-side service port will have an outside diameter of
17 mm (0.669 inches), both accurate to within 2 mm. The submitter has
not provided, and the SAE standards do not include, unique fittings for
use with small refrigerant containers or can taps.\5\ Thus, the final
use conditions do not allow use of small containers for servicing MVAC
systems.
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\5\ The SAE J639 standard specifies unique fittings for high-
side and low-side service ports and the manufacturer of HFO-1234yf
supports these fittings. The unique fitting for large containers for
use in servicing by professionals (e.g., 20 or 30 lbs) is the same
as the fitting for the low-side service port in SAE J639 and is also
specified in SAE J2844, ``R-1234yf New Refrigerant Purity and
Container Requirements Used in Mobile Air-Conditioning Systems.''
(U.S. EPA, 2010b)
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In addition to the use conditions regarding unique fittings, which
apply under appendix D to subpart G of 40 CFR part 82, EPA is requiring
use conditions for the safe design of new MVAC systems using HFO-
1234yf, consistent with standards of the automotive industry (e.g., SAE
J1739, SAE J639). These use conditions are intended to ensure that new
cars and light-duty trucks that have MVAC systems that use HFO-1234yf
are specifically designed to minimize release of the refrigerant into
the passenger cabin or onto hot surfaces that might result in ignition
or in generation of HF. The industry standard SAE J1739 gives
guidelines on designing vehicles to address these risks.
Cost and Availability
EPA received initial estimates of the anticipated cost of HFO-
1234yf from the manufacturer, claimed as confidential business
information, as part of the initial SNAP submission (EPA-HQ-OAR-2008-
0664-0013 and -0013.1). Initial publicly available estimates on the
cost of HFO-1234yf were for approximately $40-60/pound (Weissler,
2008). The first automobile manufacturer to announce its commitment to
use HFO-1234yf as a refrigerant has confirmed that the prices in its
long-term purchase contracts are in the range that EPA considered at
the time of proposal (Sciance, 2010).
In May 2010, two major chemical manufacturers, including the
original submitter, issued a press release, committing to building a
``world-scale manufacturing facility'' to produce HFO-1234yf (EPA-HQ-
OAR-2008-0664-0128.1). The same manufacturers have committed to
providing HFO-1234yf in time to meet requirements of a European Union
directive to use only refrigerants with GWP less than 150 in new
automobile designs starting in 2011.
Environmental Impacts
EPA finds that HFO-1234yf does not pose significantly greater risk
to the environment than the other substitutes that are currently or
potentially
[[Page 17492]]
available. In at least one aspect, HFO-1234yf is significantly better
for the environment than other alternatives currently found acceptable
subject to use conditions. HFO-1234yf has a hundred-year time horizon
(100-yr) global warming potential (GWP) of 4 (Nielsen et al., 2007;
Papadimitriou et al., 2007), compared to a GWP of 124 for HFC-152a, and
a GWP of 1430 for HFC-134a (IPCC, 2007). CO2, another
substitute currently under review in this end-use, has a GWP of 1,
which is lower, but comparable to the GWP of HFO-1234yf. Information on
the schedule for EPA's final rulemaking on CO2 as a
substitute in MVAC, RIN 2060-AM54, is available in EPA's regulatory
agenda at http://www.reginfo.gov/public/do/eAgendaMain. A number of
other refrigerant blends containing HFCs or HCFCs have been found
acceptable subject to use conditions in MVAC that have higher GWPs in
the range of 1000 to 2400, such as R-426A, R-414A, R-414B, R-416A, and
R-420A. Further, HFO-1234yf has no ozone depletion potential (EPA-HQ-
OAR-2008-0664-0013), comparable to CO2, HFC-152a, and HFC-
134a, and has less risk of ozone depletion than all refrigerant blends
containing HCFCs that EPA previously found acceptable subject to use
conditions for MVAC systems.
EPA also considered the aggregate environmental impact of all
anticipated emissions of HFO-1234yf, both for the proposed rule and for
this final rule. We performed a conservative analysis that assumed
widespread use of HFO-1234yf as the primary refrigerant for MVAC, as
well as for other refrigeration and air conditioning uses that were not
included in the manufacturer's original submission (ICF, 2009; ICF,
2010a,b,c,e). Thus, we believe that actual environmental impacts are
likely to be less than those we considered, either at the proposal or
final stage.
Under Clean Air Act regulations (see 40 CFR 51.100(s)) addressing
the development of State implementation plans (SIPs) to attain and
maintain the national ambient air quality standards, HFO-1234yf is
considered a volatile organic compound (VOC). Available information
indicates that HFO-1234yf has greater photochemical reactivity than
HFC-134a, which is exempt from the definition of ``VOC'' in 40 CFR
51.100(s). Some of the other acceptable substitutes in the MVAC end-use
contain VOCs, such as R-406A, R-414A, R-414B, and R-426A. VOCs can
contribute to ground-level ozone (smog) formation. For purposes of
State plans to address ground-level ozone, EPA has exempted VOCs with
negligible photochemical reactivity from regulation (40 CFR 51.100(s)).
The manufacturer of HFO-1234yf has submitted a petition to EPA
requesting that the chemical be exempted from regulation as a VOC,
based on a claim that it has maximum incremental reactivity comparable
to that of ethane (EPA-HQ-OAR-2008-0664-0116.1). Separate from this
action, EPA is reviewing that request and plans to issue a proposed
rule to address it. Information on the schedule for EPA's proposed
rulemaking for exemption from regulation as a VOC for HFO-1234yf, RIN
2060-AQ38, is available in EPA's regulatory agenda at http://www.reginfo.gov/public/do/eAgendaMain.
Regardless of whether EPA determines to exempt HFO-1234yf from
regulation as a VOC for State planning purposes, other analyses
available in the docket during the public comment period indicated that
the additional contribution to ground-level ozone due to a widespread
switch to HFO-1234yf is likely to be around 0.01% or less of all VOC
emissions, based on the formation of reactive breakdown products such
as OH- (Luecken et al., 2009). Since issuing the NPRM, we
performed an additional analysis that finds a worst-case increase in
the Los Angeles region of 0.00080 ppm, or a contribution of only 0.1%
of the 1997 8-hour standard for ground-level ozone of 0.08 ppm (ICF,
2010b). Our initial analysis at the proposal stage had estimated a
maximum increase in ozone of 1.4 to 4.0% of the standard in the same
region (ICF, 2009). The major difference between the 2009 and the 2010
versions of this analysis involved modeling of atmospheric chemistry.
The 2010 study was based on the kinetics and decomposition products
predicted for HFO-1234yf, rather than using the oxidation of sulfur
dioxide (SO2) as a proxy for decomposition of HFO-1234yf as
was done in the 2009 study. The 2010 analysis used updated baseline
emission estimates that were 1.5% higher to 5.8% lower than those in
the 2009 analysis,\6\ depending on the year analyzed (ICF, 2010e). We
also evaluated environmental impacts based on alternative emissions
estimates from a peer-reviewed journal article provided during the
public comment period (Papasavva et al., 2009); \7\ these values ranged
from 26.3% to 51.1% lower than EPA's estimates in the 2009 analysis
(ICF, 2009; ICF, 2010c).
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\6\ These changes in estimates reflect ongoing updates to EPA's
Vintaging Model, a model that considers industry trends in different
end-uses that historically have used ODS.
\7\ Analyzed scenarios considered HFO-1234yf emissions from MVAC
and from both MVAC systems and stationary air conditioning and
refrigeration systems. The analysis also considered scenarios with
typical emissions from MVAC systems during the entire year similar
to those from current MVAC systems using HFC-134a and another
scenario with reduced emissions of HFO-1234yf of approximately 50 g/
yr per vehicle, in line with emissions estimates in a study by
Papasavva et al. (2009) (EPA-HQ-OAR-2008-0664-0114.1). Major
differences between the data sources include assumptions of a lower
leak rate (5.6% of charge vs. 8% of charge) and a lower annualized
rate of leaks during servicing (3.2% of charge vs. 10% of charge)
for the Papasavva et al. paper compared to assumptions in EPA's
Vintaging Model (ICF 2010a).
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Another potential environmental impact of HFO-1234yf is its
atmospheric decomposition to trifluoroacetic acid (TFA,
CF3COOH). TFA is a strong acid that may accumulate on soil,
on plants, and in aquatic ecosystems over time and that may have the
potential to adversely impact plants, animals, and ecosystems. Other
fluorinated compounds also decompose into TFA, including HFC-134a.
However, the amount of TFA produced from HFO-1234yf in MVAC is
estimated to be at least double that of current natural and artificial
sources of TFA in rainfall (Luecken et al., 2009). An initial analysis
performed for EPA at the proposal stage found that, with highly
conservative emission estimates, TFA concentrations in rainwater could
be as high as 1.8 mg/L for the maximum monthly concentration for the
Los Angeles area and would be no higher than 0.23 mg/L on an annual
basis, compared to a no observed adverse effect concentration of 1 mg/L
for the most sensitive plant species (ICF, 2009). This analysis
concluded, ``Projected levels of TFA in rainwater should not result in
a significant risk of ecotoxicity.'' A more recent analysis by Luecken
et al (2009) that became available during the initial public comment
period reached the conclusion that emissions of HFO-1234yf from MVAC
could produce TFA concentrations in rainwater of 1/800th to 1/80th the
no-observed adverse effect level (NOAEL) for the most sensitive algae
species expected (Luecken et al., 2009). The conclusions in the Luecken
study are supported by additional analyses that have become available
since we issued the proposed rule. A study from the National Institute
of Advanced Industrial Science and Technology (AIST) in Japan, which
became available during the re-opened comment period, estimated that
concentrations of TFA in surface water would be approximately twice the
level in rainwater (Kajihara et al., 2010). This study found that this
higher level in surface water would be roughly 1/80th
[[Page 17493]]
the NOAEL for the most sensitive algae species, even with assumptions
of high emissions levels (i.e., assuming that all types of
refrigeration and AC equipment currently using HFCs or HCFCs, not just
MVAC systems, would use HFO-1234yf). Kajihara et al. (2010) evaluated
scenarios specific to Japan, with emissions of approximately 15,172
ton/yr in 2050, compared to a maximum of 64,324 metric tons/yr in 2050
in ICF, 2009 or a maximum of 24,715 metric tons/yr in 2017 in Luecken
et al (2009). All three studies noted the potential for accumulation in
closed aquatic systems.
As we developed the proposed rule, the data we relied on indicated
that in the worst case, the highest monthly TFA concentrations in the
area with the highest expected emissions, the Los Angeles area, could
exceed the no observed adverse effect concentration for the most
sensitive plant species, but annual values would never exceed that
value. Further, TFA concentrations would never approach levels of
concern for aquatic animals (ICF, 2009). In a more recent analysis, ICF
(2010a, b, c, e) performed modeling for EPA using the kinetics and
decomposition products predicted specifically for HFO-1234yf and
considered revised emission estimates that were slightly lower than in
a 2009 analysis (ICF, 2009). The revised analysis found a maximum
projected concentration of TFA in rainwater of approximately 1,700 ng/
L, roughly one-thousandth of the estimate from our 2009 analysis (ICF,
2010b). This maximum concentration is roughly 34% higher than the 1,264
ng/L reported by Luecken et al. (2009), reflecting the higher emission
estimates we used (ICF, 2010b). A maximum concentration of 1700 ng/L
corresponds to roughly 1/600th of the NOAEL for the most sensitive
algae species--thus, it is not a level of concern. We find these
additional analyses confirm that the projected maximum TFA
concentration in rainwater and in surface waters should not result in a
significant risk of aquatic toxicity, consistent with our original
proposal.
Human Health and Safety Impacts
Occupational risks could occur during the manufacture of the
refrigerant, initial installation of the refrigerant into the MVAC
system at the car assembly plant, servicing of the MVAC system, or
final disposition of the MVAC system (i.e., recycling or disposal).
Consumer risks could occur to drivers or riders in the passenger
compartment. Risks of exposure to consumers could also occur if they
purchase HFO-1234yf and attempt to install or service the MVAC system
without proper training or use of refrigerant recovery equipment. In
addition, members of the general public, consumers, and first-
responders could face risks in the case of a vehicle accident that is
severe enough to release the refrigerant.
To evaluate these potential human health and safety impacts, we
considered EPA's own risk assessments (EPA-HQ-OAR-2008-0664-0036 and -
0038), as well as detailed risk assessments with fault-tree analysis
from the SAE CRP for HFO-1234yf and CO2 (EPA-HQ-OAR-2008-
0664-0008 and -0056.2), and scientific data provided in public comments
on the topics of health and safety risks.\8\ Health and safety risks
that we evaluated included direct toxicity of HFO-1234yf, both long-
term and short-term; toxicity of HF formed through thermal
decomposition or combustion of HFO-1234yf; and flammability of HFO-
1234yf.
---------------------------------------------------------------------------
\8\ On September 30, 2010, we received a final report from the
German Federal Environment Agency (UBA) with additional information
from testing of HFO-1234yf's potential for flammability and for
generating hydrogen fluoride. Although this comment was received too
late in the rulemaking process for us to analyze it in depth, our
preliminary review found that the procedures they used contain many
unrealistic provisions that are not relevant to our decision and in
some tests did not provide proper controls (e.g., lacking a
comparison to HFC-134a under the same conditions). Concerning
flammability risk, the results do not vary significantly from those
we are relying on for the final rule. Thus, our preliminary review
of the UBA test procedures and results does not suggest that we
should re-evaluate our decision to find HFO-1234yf acceptable
subject to use conditions.
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Occupational Risks
For long-term occupational exposure to HFO-1234yf, EPA compared
worker exposures to a workplace exposure limit of 250 ppm \9\ over an
8-hour time-weighted average. For short-term occupational exposure to
HFO-1234yf, we compared worker exposure to an acute exposure limit of
98,211 ppm, divided by a margin of exposure of 30, for a value of 3270
ppm over 30 minutes.\10,11\
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\9\ This was based on a NOAEL of 4000 ppm from the study, ``An
Inhalation Prenatal Developmental Toxicity Study of HFO-1234yf
(2,3,3,3-Tetrafluoropropene) in Rabbits,'' EPA-HQ-OAR-2008-0664-
0041. We used a factor of 1.9 to account for differences in blood
concentrations between animals and humans, and a margin of exposure
or collective uncertainty factor of 30. Uncertainty factors of 3
were assigned for animal to human extrapolation, and 10 for
variability within the human population. The long-term workplace
exposure limit was calculated as follows: 4000 ppm (animal exposure)
x 1.9 (ratio of estimated human exposure/animal exposure) x \1/3\
(UF for animal to human extrapolation) x \1/10\ (UF for variability
within the human population) exposure) = 250 ppm. This value was
compared against 8-hour average concentrations. See EPA-HQ-OAR-2008-
0664-0036 and EPA-HQ-OAR-2008-0664-0038.
\10\ This was based on a NOAEL of 51,690 ppm from the study,
``Sub-acute (2-week) Inhalation Toxicity Study with HFO-1234yf in
rats,'' EPA-HQ-OAR-2008-0664-0020 through-0020.4, a factor of 1.9 to
account for differences in blood concentrations between animals and
humans and a margin of exposure or collective uncertainty factor of
30. Uncertainty factors of 3 were assigned for animal to human
extrapolation, and 10 for variability within the human population.
The short-term workplace exposure value was calculated as follows:
51,690 ppm (animal exposure) x 1.9 (ratio of estimated human
exposure/animal exposure) = 98,211 ppm This value was then divided
by the expected exposure in each scenario, and compared against the
target margin of exposure of 30. See EPA-HQ-OAR-2008-0664-0036 and
EPA-HQ-OAR-2008-0664-0038.
\11\ For comparison, the SAE CRP used exposure limits of 500 ppm
over 8 hours and 115,000 ppm over 30 minutes to evaluate risks for
these same time periods. These are based on the 8-hr Workplace
Environmental Exposure Limit (WEEL) for HFO-1234yf and for short-
term exposure, assuming a NOAEL of approximately 405,800 ppm from
the study, ``Acute (4-hour) inhalation toxicity study with HFO-
1234yf in rats.'' Note that EPA disagrees with the finding that the
acute inhalation toxicity study found a NOAEL. We consider this
study to show adverse effects at all levels because of the presence
of grey discoloration in the lungs of the test animals. In order to
ensure sufficient protection, EPA's risk assessment used a NOAEL
from a subacute study instead of a LOAEL from an acute study.
---------------------------------------------------------------------------
Section 609 of the Clean Air Act requires technicians servicing
MVAC systems for consideration (e.g., receiving money, credit, or
services in exchange for their work) to use approved refrigerant
recycling equipment properly and to have proper training and
certification. Therefore, we expect that professional technicians have
the proper equipment and knowledge to minimize their risks due to
exposure to refrigerant from an MVAC system. Thus, we found that worker
exposure would be low. Further, EPA intends to pursue a future
rulemaking under Section 609 of the CAA to apply also to HFO-1234yf
(e.g., servicing practices, certification requirements for recovery and
recycling equipment intended for use with MVACs using HFO-1234yf, any
potential changes to the rules for training and testing technicians,
and recordkeeping requirements for service facilities and for
refrigerant retailers). If workers service MVAC systems using certified
refrigerant recovery equipment after receiving training and testing,
exposure levels to HFO-1234yf are estimated to be on the order of 4 to
8.5 ppm on an 8-hour time-weighted average (as compared with a 250 ppm
workplace exposure limit) and 122 ppm on a 30-minute average (as
compared with a short-term exposure level of 98,211 ppm/[margin of
exposure of 30] or 3270 ppm). (EPA-HQ-OAR-2008-0664-0036; EPA-HQ-OAR-
2008-0664-
[[Page 17494]]
0038). We also analyzed exposure levels during manufacture and final
disposition at vehicle end-of-life, and found that they would be no
higher than 28 ppm on a 15-minute average or 8.5 ppm on an 8-hour time-
weighted average (EPA-HQ-OAR-2008-0664-0038). Therefore, the
manufacture, use, and disposal or recycling of HFO-1234yf are not
expected to present a toxicity risk to workers.
We did not analyze the risk of generation of HF in the workplace.
In its December 17, 2009 Risk Assessment for Alternative Refrigerants
HFO-1234yf and R-744 (CO2), the SAE CRP indicated that ``service
technicians will be knowledgeable about the potential for HF generation
and will immediately move away from the area when they perceive the
irritancy of HF prior to being exposed above a health-based limit''
(EPA-HQ-OAR-2008-0664-0056.2). Since there is a similar potential to
form HF from other MVAC refrigerants that have been used for years,
such as CFC-12 or HFC-134a, it is reasonable to assume that service
technicians, recyclers, and disposers will handle HFO-1234yf similarly
and that use of HFO-1234yf does not pose a significantly greater risk
in the workplace with regard to HF generation than the use of those
other refrigerants.
In that same report, the SAE CRP also discussed qualitatively the
risks for emergency responders, such as firefighters or ambulance
workers that respond in case of a vehicle fire or collision. With
regard to risk of fire, the CRP report stated that ``Due to the low
burning velocity of HFO-1234yf, ignition of the refrigerant will not
contribute substantially to a pre-existing fire'' (EPA-HQ-OAR-2008-
0664-0056.2). EPA considers this reasonable, given a burning velocity
for HFO-1234yf of only 1.5 cm/s. This is more than an order of
magnitude less than the burning velocity of gasoline, which is
approximately 42 cm/s (Ceviz and Yuksel, 2005). Concerning first
responder exposure to HF, the SAE CRP stated, ``Professional first
responders also have training in chemical hazards and possess
appropriate gear which will prevent them from receiving HF exposures
above health-based limits'' (EPA-HQ-OAR-2008-0664-0056.2). We agree
with this assessment. Other MVAC refrigerants containing fluorine such
as CFC-12, which was historically used, and HFC-134a, which is the
predominant refrigerant currently in use, also can produce HF due to
thermal decomposition or combustion, and smoke and other toxic
chemicals are likely to be present in case of an automotive fire (CRP,
2008). Therefore, it is reasonable to expect that first responders are
prepared for the presence of HF and other toxic chemicals when
approaching a burning vehicle and that they will wear appropriate
personal protective equipment.
EPA's risk screen for HFO-1234yf evaluated flammability risks,
including occupational risks. Modeling of concentrations of HFO-1234yf
in workplace situations such as at equipment manufacture and during
disposal or recycling at vehicle end-of-life found short-term, 15-
minute concentrations of 28 ppm or less--far below the lower
flammability limit (LFL) of 6.2% by volume (62,000 ppm) (EPA-HQ-OAR-
2008-0664-0038). The SAE CRP's risk assessments evaluated flammability
risks by comparing concentrations of HFO-1234yf with the LFL of 6.2%.
The SAE CRP conducted Computational Fluid Dynamics (CFD) modeling of
exposure levels in case of a leak in a system in a service shop. The
SAE CRP's earlier February 26, 2008 risk assessment found that a leaked
concentration of HFO-1234yf exceeded the LFL only in the most
conservative simulation, with the largest refrigerant leak and with all
air being recirculated within the passenger cabin (EPA-HQ-OAR-2008-
0664-0010). Updated CFD modeling performed for the December, 2010 SAE
CRP risk assessment found that concentrations of HFO-1234yf sometimes
exceeded the LFL, but only within ten centimeters of the leak or less
(EPA-HQ-OAR-2008-0664-0056.2). The risk assessment found the risk of
this occupational exposure scenario to be on the order of
10-26 cases per working hour. We note that HFO-1234yf is
less flammable and results in a less energetic flame than a number of
fluids that motor vehicle service technicians and recyclers or
disposers deal with on a regular basis, such as oil, anti-freeze,
transmission fluid, and gasoline. HFO-1234yf is also less flammable
than HFC-152a, a substitute that we have already found acceptable for
new MVAC systems subject to use conditions. Thus, EPA finds that the
risks of flammability in the workplace from HFO-1234yf are similar to
or lower than the risk posed by currently available substitutes when
the use conditions are met.
Consumer Exposure
EPA's review of consumer risks from toxicity of HFO-1234yf
indicated that potential consumer (passenger) exposure from a
refrigerant leak into the passenger compartment of a vehicle is not
expected to present an unreasonable risk (EPA-HQ-OAR-2008-0664-0036,
EPA-HQ-OAR-2008-0664-0038). However, consumer exposure from filling,
servicing, or maintaining MVAC systems may cause exposures at high
enough concentrations to warrant concern. Specifically, this risk may
be due to a lack of professional training and due to refrigerant
handling or containment without the use of refrigerant recovery
equipment certified in accordance with the regulations promulgated
under CAA Section 609 and codified at subpart B of 40 CFR part 82.
Consumer filling, servicing, or maintaining of MVAC systems may cause
exposures at high enough concentrations to warrant concern (EPA-HQ-OAR-
2008-0664-0036). However, this rule does not specifically allow for use
of HFO-1234yf in consumer filling, servicing, or maintenance of MVAC
systems. The manufacturer's submission specifically addressed HFO-
1234yf as a refrigerant for use by OEMs and by professional technicians
(EPA-HQ-OAR-2008-0664-0013.1).
The use conditions in this final rule provide for unique service
fittings relevant to OEMs and to professional technicians (i.e., unique
fittings for the high-pressure side and for the low-pressure side of
the MVAC system and unique fittings for large cylinders of 20 lb or
more). EPA would require additional information on consumer risk and a
set of unique fittings from the refrigerant manufacturer for use with
small cans or containers of HFO-1234yf before we would be able to issue
a revised rule that allows for consumer filling, servicing, or
maintenance of MVAC systems with HFO-1234yf.
EPA has issued a significant new use rule (SNUR) under the
authority of TSCA (October 27, 2010; 75 FR 65987). Under 40 CFR part
721, EPA may issue a SNUR where the Agency determines that activities
other than those described in the premanufacture notice may result in
significant changes in human exposures or environmental release levels
and that concern exists about the substance's health or environmental
effects. Manufacturers, importers and processors of substances subject
to a SNUR must notify EPA at least 90 days before beginning any
designated significant new use through a significant new use notice
(SNUN). EPA has 90 days from the date of submission of a SNUN to decide
whether the new use ``may present an unreasonable risk'' to human
health or the environment. If the Agency does not determine that the
new use ``may present an unreasonable risk,'' the submitter would be
allowed to engage in the use, with or without certain restrictions. The
significant new
[[Page 17495]]
uses identified in the SNUR for HFO-1234yf are: (1) Use other than as a
refrigerant in motor vehicle air conditioning systems in new passenger
cars and vehicles; (2) commercial use other than in new passenger cars
and vehicles in which the charging of motor vehicle air conditioning
systems with HFO-1234yf was done by the motor vehicle OEM; and (3)
distribution in commerce of products intended for use by a consumer for
the purposes of servicing, maintenance and disposal involving HFO-
1234yf.
Under existing regulations in appendix D to subpart G of 40 CFR
part 82, ``A refrigerant may only be used with the fittings and can
taps specifically intended for that refrigerant and designed by the
manufacturer of the refrigerant. Using a refrigerant with a fitting
designed by anyone else, even if it is different from fittings used
with other refrigerants, is a violation of this use condition.'' The
manufacturer and submitter for HFO-1234yf has provided unique fittings
for the high-pressure side and for the low-pressure side of the MVAC
system and for large cylinders for professional use (typically 20 lb or
more \12\). Therefore, until the manufacturer provides unique fittings
to EPA's SNAP Program for use with can taps or other small containers
for consumer use and until EPA publishes a final rule identifying such
unique fittings, it would be a violation of the use condition in
appendix D to use HFO-1234yf in small cans or containers for MVAC.
Before issuing a rule allowing use of HFO-1234yf with fittings for
small cans or containers for MVAC, we would first need to conclude
through either review under TSCA or under the SNAP program that use of
these smaller canisters would not pose an unreasonable risk to
consumers.
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\12\ EPA has issued lists of approved unique fittings for
refrigerants in MVAC (see http://www.epa.gov/ozone/snap/refrigerants/fittlist.html). These have been issued for the high-
side service port, low-side service port, 30-lb cylinders (that is,
the most typical size container for use in professional servicing),
and small cans (containers typically used by consumers). The label
``30-lb cylinders'' is not intended to restrict the existence of
other container sizes that professional service technicians might
use (e.g., 50 lb, 20 lb, 10 lb).
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In our review of consumer risks from HFO-1234yf, we considered
information concerning consumer exposure to HF from thermal
decomposition or combustion of HFO-1234yf. EPA's analysis at the time
of the proposed rule focused on the flammability risk to consumers,
which at the time we believed to be a significant risk in its own
right, as well as a way to prevent consumer exposure to HF from
combustion of HFO-1234yf. However, in preparing our proposal, we had
available and did consider the SAE CRP's 2008 evaluation of scenarios
that might cause consumer or occupational exposure to HF (CRP, 2008).
This report stated:
Decomposition of HFO-1234yf in a fire scenario might, in theory,
pose a significant acute health risk to passengers or firemen. But
in the event of a fire, other toxic chemicals will be produced by
combustion of other automotive components and thus decomposition of
the refrigerant may increase the risk for fire fighters and would
not introduce an entirely new type of hazard. It is also anticipated
that only a small portion of the refrigerant charge will be
converted to these decomposition products. In U.S. EPA's assessment
of risk of R-152a and CO2 (R-744), the agency cited a
study by Southwestern Laboratories which indicated that a 100% R-
134a atmosphere only produced an HF concentration of 10 ppm when
passed through a tube heated to 1,000 [deg]F (Blackwell et al.,
2006). A search of the medical literature also did not reveal any
published reports of injuries to fire fighters or vehicle passengers
resulting from exposures to COF2 or HF produced in fires
involving refrigerants. (EPA-HQ-OAR-2008-0664-0008, p. 67)
After the SAE CRP's 2008 evaluation, SAE CRP members conducted
tests to measure HF concentrations and to identify factors that were
most likely to lead to HF formation (EPA-HQ-OAR-2008-0664-0056.2). One
test on HF concentrations inside a car cabin found maximum
concentrations were in the range of 0 to 35 ppm in trials both with
HFO-1234yf and with HFC-134a, with concentrations dropping to 10 ppm or
less after 10 minutes. In a second test of HF generated in the engine
compartment, HF concentrations from thermal decomposition of HFO-1234yf
reached as high as 120 ppm in the engine compartment in the worst case,
with interior passenger cabin values of 40 to 80 ppm. Under the same
extreme conditions (flash ignition, temperature of 700 [deg]C, closed
hood), HF concentrations from thermal decomposition of HFC-134a reached
36.1 ppm in the engine compartment with interior passenger cabin values
of 2 to 8 ppm. The other trials with less extreme conditions found HF
concentrations from HFO-1234yf in the engine compartment of 0 to 8 ppm.
The SAE CRP selected an Acute Exposure Guideline Limit (AEGL)-2 of
95 ppm over 10 minutes as its criterion for determining toxicity risk
from HF.\13\ Thus, even assuming levels inside a passenger compartment
reached the highest level that occurred during the tests--80 ppm--a
passenger inside a vehicle would at worst experience discomfort and
irritation, rather than any permanent effects. HF levels that could
result in similar effects were also observed for HFC-134a. The SAE CRP
concluded that the probability of such a worst-case event is on the
order of 10-12 occurrences per operating hour \14\ (EPA-HQ-
OAR-2008-0664-0056.2). This level of risk is similar to the current
level of risk of HF generated from HFC-134a (EPA-HQ-OAR-2008-0664-
0086.1). To date, EPA is unaware of any reports of consumers affected
by HF generated by HFC-134a, which has been used in automobile MVAC
systems across the industry since 1993. Thus, we do not expect there
will be a significant risk of HF exposure to consumers from HFO-1234yf.
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\13\ The AEGL-2 is defined as ``the airborne concentration of a
substance * * * above which it is predicted that the general
population, including susceptible individuals could experience
irreversible or other serious, long lasting adverse effects or an
impaired ability to escape.'' http://www.epa.gov/oppt/aegl/pubs/define.htm.
\14\ If we assume 250 million passenger vehicles in the U.S. and
typical driving times of 500 hours per year per vehicle, a risk of
4.6 x 10-12 per operating hour equates roughly to one
event every 2 years for all drivers in the entire U.S.
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Depending on the charge size of an HFO-1234yf MVAC system, which
may range from as little as 400 grams to as much as 1600 grams (ICF,
2008), it is possible in a worst case scenario to reach a flammable
concentration of HFO-1234yf inside the passenger compartment. This
could occur in the case of a collision that ruptures the evaporator in
the absence of a switch or other engineering mitigation device to
prevent flow of high concentrations of the refrigerant into the
passenger compartment, provided that the windows and windshield remain
intact. As stated in the SAE CRP, ignition of the refrigerant once in
the passenger cabin is unlikely (probability on the order of
10-14 occurrences per operating hour) because the only
causes of ignition within the passenger cabin with sufficient energy to
ignite the refrigerant would be use of a butane lighter (EPA-OAR-2008-
0664-0056.2). If a passenger were in a collision, or in an emergency
situation, it is unlikely that they would choose to operate a butane
lighter in the passenger cabin. Additionally, it is unlikely ignition
would occur from a flame from another part of the vehicle because
automobiles are constructed to seal off the passenger compartment with
a firewall. If a collision breached the passenger compartment such that
a flame from another part of the vehicle could reach it, that breach
would also create ventilation that would lower the refrigerant
concentration below the
[[Page 17496]]
lower flammability limit. Similarly, if either a window or the
windshield were broken in the collision, the ventilation created would
lower the refrigerant concentration below the lower flammability limit.
Therefore, EPA finds that flammability risks of HFO-1234yf to
passengers inside a vehicle will be low. Further, these risks are
likely to be less than those from HFC-152a, another flammable
refrigerant that EPA has previously found acceptable subject to use
conditions, because HFC-152a has a lower LFL and a lower minimum
ignition energy than HFO-1234yf (EPA-HQ-OAR-2008-0664-0008, -0013.4, -
0056.2).
Overall Conclusion
EPA finds that the use of HFO-1234yf in new passenger vehicle and
light-duty truck MVAC systems, subject to the use conditions being
adopted in the final rule, does not present a significantly greater
risk to human health and the environment compared to the currently-
approved MVAC alternatives or as compared to CO2, which has
been proposed for approval in this end-use.
VI. What is the relationship between this SNAP rule and other EPA
rules?
A. Significant New Use Rule
Under the Toxics Substances Control Act, EPA has issued a
Significant New Use Rule (75 FR 65987; October 27, 2010) for 1-propene,
2,3,3,3- tetrafluoro-, which is also known as HFO-1234yf. This rule
requires persons who intend to manufacture, import, or process HFO-
1234yf for a use that is designated as a significant new use in the
final SNUR to submit a SNUN at least 90 days before such activity may
occur. EPA has 90 days from the date of submission of a SNUN to decide
whether the new use ``may present an unreasonable risk'' to human
health or the environment. If the Agency does not determine that the
new use ``may present an unreasonable risk,'' the submitter would be
allowed to engage in the use, with or without certain restrictions. The
significant new uses identified in the final SNUR and subject to the
SNUN requirement are: Use other than as a refrigerant in motor vehicle
air conditioning systems in new passenger cars and vehicles; commercial
use other than in new passenger cars or vehicles and in which the
charging of motor vehicle air conditioning systems with HFO-1234yf was
done by the motor vehicle OEM; and distribution in commerce of products
intended for use by a consumer for the purpose of servicing,
maintenance and disposal involving HFO-1234yf. The health concerns
expressed in the final SNUR are based primarily on potential inhalation
exposures to consumers during ``do-it-yourself'' servicing, as well as
a number of other relevant factors.
B. Rules Under Sections 609 and 608 of the Clean Air Act
Section 609 of the CAA establishes standards and requirements
regarding servicing of MVAC systems. These requirements include
training and certification of any person that services MVAC systems for
consideration,\15\ as well as standards for certification of equipment
for refrigerant recovery and recycling. EPA has issued regulations
interpreting this statutory requirement and those regulations are
codified at subpart B of 40 CFR part 82. The statutory and regulatory
provisions regarding MVAC servicing apply to any refrigerant
alternative and are not limited to refrigerants that are also ODS. This
final SNAP rule addresses the conditions for safe use of HFO-1234yf in
new MVAC systems. Thus, the requirements in this rule apply primarily
to OEMs, except for specific requirements for service fittings unique
to HFO-1234yf. MVAC end-of-life disposal and recycling specifications
are covered under section 608 of the CAA and our regulations issued
under that section of the Act.
---------------------------------------------------------------------------
\15\ Service for consideration means receiving something of
worth or value to perform service, whether in money, credit, goods,
or services.
---------------------------------------------------------------------------
VII. What is EPA's response to public comments on the proposal?
This section of the preamble summarizes the major comments received
on the October 19, 2009 proposed rule, and EPA's responses to those
comments. Additional comments are addressed in a response to comments
document in docket EPA-HQ-OAR-2008-0664.
A. Acceptability Decision
Comment: Several commenters supported EPA's proposal to find HFO-
1234yf an acceptable substitute for CFC-12 in MVACs. These commenters
stated that available information indicates that HFO-1234yf will not
pose significant health risks or environmental concerns under
foreseeable use and leak conditions and that it has a strong potential
to reduce greenhouse gas emissions from motor vehicles. Also, these
commenters declared that HFO-1234yf's risks were similar to or less
than those of other available alternatives, such as HFC-134a, HFC-152a,
and CO2. A commenter referenced the work of the SAE CRP,
which concluded that HFO-1234yf can be used safely through established
industry practices for vehicle design, engineering, manufacturing, and
service.
Other commenters opposed finding HFO-1234yf acceptable or stated
that there was insufficient information to support a conclusion. These
commenters stated that the risks of HFO-1234yf were greater than those
of other available alternatives, such as HFC-134a, CO2, and
hydrocarbons.
Response: For the reasons provided in more detail above, EPA has
determined that HFO-1234yf, if used in accordance with the adopted use
conditions, can be used safely in MVAC systems in new passenger
vehicles and light-duty trucks. The use conditions established by this
final rule ensure that the overall risks to human health and the
environment are comparable to or less than those of other available or
potentially available substitutes, such as HFC-134a, HFC-152a, or
CO2. EPA did not compare the risks to those posed by
hydrocarbons since we have not yet received adequate information for
hydrocarbons that would allow us to make such a comparison for use in
MVAC.\16\
---------------------------------------------------------------------------
\16\ EPA previously reviewed two hydrocarbon blends for use in
MVAC and found them unacceptable, stating ``Flammability is a
serious concern. Data have not been submitted to demonstrate that
[the hydrocarbon blend] can be used safely in this end-use.''
Appendixes A and B to subpart G of 40 CFR part 82.
---------------------------------------------------------------------------
Comment: Some commenters suggested that EPA should consider other
substitutes for CFC-12 in MVAC, such as CO2 or hydrocarbons.
An organization representing the automotive industry stated that the
risks from using CO2 in MVAC systems are below the
probability of other adverse events which society considers acceptable
and are roughly 1.5 orders of magnitude greater than the risks from
using HFO-1234yf.
Response: This rule only concerns EPA's decision on the use of HFO-
1234yf in new passenger vehicles and light-duty trucks. In a separate
action, EPA has proposed to find CO2 acceptable subject to
use conditions as a substitute for CFC-12 in MVAC systems for new motor
vehicles (September 16, 2006; 71 FR 55140). Information on the schedule
for EPA's final rulemaking on CO2 as a substitute in MVAC,
RIN 2060-AM54, is available in EPA's regulatory agenda at http://www.reginfo.gov/public/do/eAgendaMain. We currently have inadequate
information on hydrocarbons to consider adding them to the list of
substitutes for MVAC. We
[[Page 17497]]
will review additional substitutes if they are submitted with complete
and adequate data to allow an evaluation of whether such substitutes
may be used safely within the meaning of section 612 of the CAA as
compared with other existing or potential substitutes in the MVAC end-
use.
B. Use Conditions
Comment: Several commenters stated that the proposed use conditions
limiting concentrations of HFO-1234yf below the lower flammability
limit are overly stringent or even impossible to meet and are not
needed for safe usage. Some automobile manufacturers suggested relying
upon established standards and practices, such as SAE protocols and
standards, instead of use conditions. Some commenters suggested
alternative language for use conditions. Other commenters expressed
concern that the proposed use conditions limiting concentrations of
HFO-1234yf would preclude the use of HFO-1234yf by any vehicle that is
not initially designed to use this refrigerant.
Response: As described above, EPA agrees that the use conditions,
as proposed, require modification. In this final rule, we have removed
the first three proposed use conditions, which required design to keep
refrigerant concentrations below the LFL. See section IV of the
preamble, ``What are the final use conditions and why did EPA finalize
these conditions?'' for our basis. With respect to the commenter who
suggested that the proposed use conditions limiting concentrations of
HFO-1234yf below the LFL would not allow use except in systems
initially designed to use this refrigerant, we note that this decision
is limited to use in new motor vehicles and light-duty trucks. Further,
the proposed use conditions limiting refrigerant concentration are not
included in the final rule and thus do not have implications for a
future decision concerning retrofits.
Comment: One commenter provided test results from the Bundesanstalt
f[uuml]r Materialforschung und -pr[uuml]fung (BAM--Federal Institute
for Materials Research and Testing) that tested various mixtures of
HFO-1234yf and ethane (EPA-HQ-OAR-2008-0664-0053.3). The commenter
stated that the tests show that explosions can occur at HFO-1234yf
concentrations below its lower flammability limit (LFL) of 6.2% when
minimal amounts of gaseous hydrocarbons are available. This commenter
stated that the maximum concentrations of HFO-1234yf allowed under any
use condition need to be far below the 6.2% LFL to ensure safety. Other
commenters agreed with these concerns. Yet other commenters looked at
the same test data and stated that the testing was not relevant to
real-world situations in MVAC because it is unlikely that such large
amounts of ethane or other gaseous hydrocarbons (0.8-2.4% by volume)
would form in a vehicle. One commenter stated that HFO-1234yf reduces
the flammability of ethane compared to ethane alone, and that HFO-
1234yf reduces flammability of ethane more than CO2 or
argon, substances used as fire suppressants (EPA-HQ-OAR-2008-0664-
0115.1).
Response: We do not believe that the BAM testing of the
flammability limits of mixtures of HFO-1234yf and ethane is relevant to
assessing the risks of HFO-1234yf as a refrigerant in MVAC. Examples of
flammable substances in the engine compartment may include compressor
oil mixed with the refrigerant, motor oil, cleaners, anti-freeze,
transmission fluid, brake fluid, and gasoline. These are typically
liquid and there is no evidence that any vapors that might form would
include significant amounts of ethane. These fluids typically contain
larger molecules with higher boiling points than ethane (e.g., octane,
polyalkylene glycol). It seems more likely, as one commenter suggested,
that these flammable fluids would ignite before breaking down into
concentrations of ethane considered in the BAM testing. Further, the
results of the testing are not surprising; based on a scientifically
known chemical equilibrium principle known as Le Chatelier's
principle--the lower flammability limit of a mixture of two flammable
substances falls between the lower flammability limits of the two
individual substances. The range of LFLs for flammable mixtures of
ethane and refrigerants HFC-134a, HFO-1234yf, and CO2 is
largest for CO2 and is similar for HFC-134a and HFO-1234yf
(Besnard, 1996).
A more relevant test to compare risks for HFO-1234yf and other
alternative refrigerants in MVAC is to consider flammability of a
mixture of compressor oil and refrigerant, as occurs in MVAC systems.
Such testing, conducted as part of the SAE CRP, found that mixtures of
HFO-1234yf and 5% oil and HFC-134a and 5% oil both ignited at
temperatures higher than what usually occurs in a vehicle (730 [deg]C
or higher for HFO-1234yf and 800 [deg]C or higher for HFC-134a).
Furthermore, we note that the final use conditions do not rely on
the lower flammability limit. As explained in more detail in sections
IV and V of the preamble, ``What are the final use conditions and why
did EPA finalize these use conditions?'' and ``Why is EPA finding HFO-
1234yf acceptable subject to use conditions?'', we believe that the
risks from HFO-1234yf and its decomposition products are very small and
are comparable to or less than the risks from other acceptable
alternatives available or potentially available for use in MVAC
systems. The use conditions established in this final rule require
manufacturers to design systems to prevent leakage from refrigerant
system connections that might enter the passenger cabin, and to
minimize impingement of refrigerant and oil onto hot surfaces, as
required by SAE J639 (adopted 2011). These use conditions will further
reduce already low risks from flammability and HF generation.
Comment: One commenter provided data from a presentation showing
that the lower flammability limit of HFO-1234yf decreases as
temperature increases. The commenter stated that the proposed LFL of
6.2% may not be conservative enough.
Response: EPA agrees that the LFL decreases as temperature
increases. However, for the analysis relied on for the proposed rule,
we considered an LFL relevant to the temperatures that might be
expected in a collision or leak scenario and that would not be so high
as to be a higher risk factor than exposure to HF. The data provided by
the commenter show an LFL of 5.7% at 60 [deg]C (140 [deg]F) and an LFL
of 5.3% at 100 [deg]C (212 [deg]F). If a passenger were exposed to
temperatures this high in the passenger compartment for any extended
period of time, he or she would suffer from the heat before there was a
risk of the refrigerant igniting. However, after considering the
available information, we find it is not necessary to require a
concentration of HFO-1234yf below the LFL to address this refrigerant's
risks; rather, risks are sufficiently addressed with the final use
conditions. As discussed above in section IV of the preamble, ``What
are the final use conditions and why did EPA finalize these
conditions?'', we believe that the flammability risks from HFO-1234yf
are very small and overall risks from HFO-1234yf are comparable to or
less than the risks from other acceptable alternatives used in MVAC.
EPA finds that the use conditions in this final rule are sufficient to
manage risks of injury or adverse health effects caused by HFO-1234yf.
Comment: Regarding the first proposed use condition that would
limit the concentration of HFO-1234yf below the LFL in the passenger
cabin, several commenters stated that the risks of refrigerant leaking
into the passenger compartment and exceeding the LFL are
[[Page 17498]]
very low. Some automobile manufacturers stated that it may not be
possible to keep the concentration below the LFL in the event of a
collision; however, the commenters said that even if concentrations in
the passenger cabin exceeded the LFL, it would be extremely difficult
to ignite the refrigerant. Some commenters stated that the engineering
strategies that would be necessary to implement the proposed use
condition would actually increase overall risk by increasing the risk
of conveying smoke and fumes from the engine compartment into the
passenger compartment in the event of an accident. Some commenters
suggested alternative language for the use condition to give greater
flexibility in engineering responses to allow for differences between
vehicles.
Response: As discussed above in section IV of the preamble, EPA is
not including the proposed use condition requiring that a specific
level of refrigerant concentration inside the passenger cabin is not
exceeded.
Comment: One commenter suggested that the use conditions for
limiting concentrations in the passenger cabin should require the
incorporation of engineering strategies and/or devices ``such that
foreseeable leaks'' rising to the specified concentration levels can be
avoided. Similarly, the commenter stated that any use condition
limiting concentrations in the engine compartment should be limited to
``prevention of ignition caused by foreseeable leaks.'' The commenter
noted that EPA did this in a similar use condition in its final SNAP
rule for HFC-152a, another flammable refrigerant for MVAC with greater
flammability risk. The commenter stated that this would be consistent
with safety requirements of the National Highway Traffic Safety
Administration (NHTSA) and would ensure that EPA's use conditions are
feasible.
Response: As discussed above in section IV of the preamble, EPA is
not including the proposed use condition and is not limiting the
refrigerant concentration inside the passenger cabin or the engine
compartment.
Comment: A number of commenters did not support the proposed use
condition on concentrations of HFO-1234yf in hybrid and electric
vehicles. One commenter recommended eliminating this use condition, as
the SAE CRP risk assessment concludes there are no real world safety
risks. Another commenter suggested referring to the SAE or ISO
(International Organization for Standardization) standards in place of
a specific use condition. One commenter stated that electric terminals
on hybrid vehicles are well protected to prevent fires and should not
ignite the refrigerant. Another commenter stated that an accident
severe enough to cause refrigerant leakage would also result in damage
to the duct between the evaporator [in the MVAC system] and the battery
pack, preventing an increase in refrigerant concentrations at the
battery pack. One commenter stated that it is difficult to establish
generic SNAP use conditions for hybrid vehicles, and individual
manufacturers need to understand particular design features of their
hybrid vehicles to ensure safe refrigerant application.
Three commenters expressed concern for using HFO-1234yf in hybrid
and electric vehicles and stated that the use condition is not
conservative enough. One commenter stated that the maximum
concentrations of HFO-1234yf need to be far below the 6.2% LFL based on
new tests done at the Federal Institute for Materials Research and
Testing (BAM) and that they are unsure whether or not additional
measures can effectively avoid the risk of explosive mixtures. Another
commenter stated that HFO-1234yf would raise concerns in the field of
battery cooling needed in electric vehicles because flammability and
chemical reactions would pose major risks, which could lead to legal
consequences for OEMs.
Response: As discussed above in section IV of the preamble, EPA is
not including the proposed use condition and is not requiring
protective devices, isolation and/or ventilation techniques where
levels of refrigerant concentration may exceed the LFL in proximity to
exhaust manifold surfaces or near hybrid or electric vehicle power
sources. As discussed above, we do not believe that the BAM testing of
the flammability limits of mixtures of HFO-1234yf and ethane is
relevant to assessing the risks of HFO-1234yf as a refrigerant in MVAC.
Based on information provided by OEMs that manufacture hybrid vehicles,
we conclude that there will be sufficient protection against fire risk
and generation of HF in the engine compartment for hybrid vehicles
because they have protective coverings on power sources that will
prevent any sparks that might have enough energy to ignite refrigerant
and engine surfaces will not be hotter than those in conventional
vehicles (EPA-HQ-OAR-2008-0664-0081.1, -0081.2). Further, we agree that
it is reasonable to assume that a collision severe enough to release
refrigerant from the evaporator (under the windshield) would also
release it in a location far enough away from the battery pack to keep
refrigerant concentrations at the battery pack below the LFL. CFD
modeling performed for the December, 2010 SAE CRP risk assessment found
that concentrations of HFO-1234yf only exceeded the LFL within ten
centimeters of the leak or less (EPA-HQ-OAR-2008-0664-0056.2), but the
battery pack is typically placed more than ten centimeters away from
the evaporator. EPA expects that OEMs will include assessment of risks
from the exhaust manifold, hybrid power source, and electric vehicle
power source as part of the FMEA required under one of the final use
conditions in this rule.
Comment: Some commenters responded to EPA's request for comment as
to whether the use conditions should apply only when the car ignition
is on. These commenters indicated that it is unnecessary for the use
conditions on refrigerant concentrations within the passenger
compartment to apply while a vehicle's ignition is off because it is
unlikely that a collision would occur, that high temperatures would
occur, or that refrigerant would enter the passenger cabin when the
ignition, and thus the MVAC system, is off. Another commenter stated
that it should be mandatory for all electric power sources to be shut
off when the ignition is off.
Response: As discussed above in section IV of the preamble, EPA is
not including the proposed use conditions that specified a refrigerant
concentration not to be exceeded.
Comment: Several commenters stated that the proposed limits on
concentrations of HFO-1234yf in the engine compartment cannot be met,
even hypothetically, and that imposition of such a use condition would
delay or even prevent the use of HFO-1234yf. Other commenters stated
that the engineering required to meet the proposed use condition is
almost certain to preclude the use of HFO-1234yf by any vehicle that
was not initially designed to use this refrigerant.
Response: EPA is not including in the final rule the proposed use
condition that sets a specific limit for refrigerant concentrations
inside the engine compartment. See section IV of the preamble, ``What
are the final use conditions and why did EPA finalize these
conditions?'' for further rationale.
Comment: Several commenters agreed with EPA's proposal to require
use of unique fittings and a warning label that identify the new
refrigerant and restrict the possibility of cross-contamination with
other refrigerants. Other commenters suggested that no use
[[Page 17499]]
conditions are necessary because established standards and practices
would be adequate for safe use of HFO-1234yf.
Response: The use conditions referenced by the commenters were
established in a separate final rule, promulgated in 1996, which
applies to all refrigerants used in MVAC (see appendix D to subpart G
of 40 CFR part 82). EPA has not proposed to modify that existing rule
for purposes of its acceptability determination for HFO-1234yf. These
requirements indicate to technicians the refrigerant they are using and
thus help reduce risks to the technician by ensuring that the
technician will handle the refrigerant properly. In addition, these use
conditions serve to prevent contamination of refrigerant supplies
through unintended mixing of different refrigerants. For purposes of
meeting that existing regulatory requirement, this final rule specifies
use of fittings for the high-pressure side service port, the low-
pressure side service port, and for refrigerant containers of 20 pounds
or greater. The submitter for HFO-1234yf has provided these fittings to
the Agency and they are consistent with the SAE standard J639. In
addition, the final rule retains the requirement for a warning label
identifying the refrigerant, consistent with SAE J639.
Comment: Some commenters agreed with EPA's proposal to require a
high-pressure compressor cut-off switch, as per SAE J639. Another
commenter suggested that the compressor cut-off switch would be useful
for all systems in which the discharge pressure can reach the burst
pressure, not just those systems with pressure relief devices.
Response: EPA is maintaining the requirement that HFO-1234yf MVAC
systems must have a high-pressure compressor cut-off switch by
requiring compliance with the SAE J639 standard. The SAE J639 standard
requires a pressure relief device on the refrigerant high-pressure side
of the compressor for all MVAC systems, and so the compressor cut-off
switch will be required for all systems, as suggested by the commenter.
Comment: Several commenters supported the requirement for vehicle
makers to conduct and maintain FMEAs. Other automobile manufacturers
stated that the final SNAP rule finding HFC-152a acceptable as a
substitute for CFC-12 in MVAC included this as a comment rather than as
a use condition, and suggested that EPA do the same in the final rule
for HFO-1234yf. Another commenter stated that FMEAs for each vehicle
design are standard industry practice, and so no use condition is
required; this commenter provided language for an alternate use
condition should EPA choose to specify a use condition for vehicle
design.
Response: EPA is retaining the requirement for FMEAs in the final
rule as a use condition, rather than simply as an unenforceable
comment. In an FMEA, vehicle designers analyze all the ways in which
parts of the MVAC system could fail and identify how they will address
those risks in design of the system. In addition, keeping records of an
FMEA is important to ensuring safe use because it documents that
vehicle designers have complied with the safety requirements of this
rule. We believe that it is necessary to retain this requirement as a
use condition in order to ensure that OEMs are required to analyze and
address the risks and to document those efforts such that this analysis
is available to demonstrate compliance to EPA in case of an EPA
inspection. Information in the FMEAs complements the safety
requirements in SAE J639 and is useful for demonstrating compliance.
Because the revised SAE J639 standard refers to use of FMEAs more
extensively, risk assessment using FMEAs is more critical for HFO-
1234yf than it was for HFC-152a
Comment: A commenter requested that EPA specifically allow
manufacturers to perform FMEAs according to equivalent standards
developed by organizations other than SAE (e.g., the International
Organization for Standardization [ISO], the German Institute for
Standards [DIN], or the Japan Automobile Manufacturers Association
[JAMA]).
Response: We agree that standards from other standard-setting
organizations may provide equivalent assurance of safe use. However, we
are not aware at this time of any standards that do so. In order to
ensure safe use of HFO-1234yf, we would need to review any other
standard to ensure that it provides equivalent assurances of safety
before allowing its use in place of the SAE standard. An OEM, for
example, could petition EPA's SNAP program and provide copies of the
other standard for consideration. If we agree that the other standard
is equivalent, then we would add it to the use condition on FMEAs
through a rulemaking.
Comment: A commenter expressed that EPA's approach to setting use
conditions infringes upon the Department of Transportation's motor
vehicle safety jurisdiction and that EPA does not have the authority to
protect against any fire risk associated with motor vehicles.
Response: As an initial matter, we note that the commenter does not
point to any specific legislative authority that supports his claim.
Regardless, EPA disagrees with this commenter. Section 612 of the CAA
provides that EPA may find substitutes for ODS acceptable if they
present less risk to human health and the environment than other
substitutes that are currently or potentially available. Congress did
not establish any limits on EPA's authority for ensuring that
substitutes are not more risky than other substitutes that are
available and EPA has consistently interpreted this provision to allow
the Agency to establish use conditions to ensure safe use of
substitutes. In this case, we find that HFO-1234yf may be used safely,
and with risks comparable to or less than those of other available
substitutes for CFC-12 in the MVAC end-use, so long as it is used
according to the use conditions established by this action. If the
commenter were correct that the Department of Transportation (DOT) has
sole authority to address safety risks from MVAC systems, in the
absence of standards from DOT addressing HFO-1234yf's risks, EPA would
need to determine that HFO-1234yf is unacceptable for use in MVACs.
C. Environmental Impacts
1. Ozone Depletion Potential
Comment: Several commenters agreed with EPA's proposed finding that
HFO-1234yf would not contribute significantly to stratospheric ozone
depletion, and that the ozone depletion potential (ODP) of HFO-1234yf
is at or near zero. Two commenters claimed that the ODP of HFO-1234yf
should be stated as ``zero'' instead of ``nearly zero,'' and one
commenter requested that EPA clarify that HFO-1234yf has an ODP less
than that of HFC-134a.
Other commenters disagreed with EPA's statement that the ODP of
HFO-1234yf is at or near zero. One commenter expressed concern that ODS
may be used in the HFO-1234yf manufacturing process, or emissions of
HFO-1234yf and its by-products from the manufacturing process may break
down into gases with ODPs; this commenter advised EPA against listing
HFO-1234yf as an acceptable replacement for HFC-134a in MVACs. Another
commenter stated that HFO-1234yf requires further investigation since
unsaturated HFCs such as HFO-1234yf might break down into gases that
are ozone depleting.
[[Page 17500]]
Response: It is generally agreed among scientists that substances
that contain chlorine, bromine or iodine may have an ozone depletion
potential while those that contain only fluorine effectively have no
ODP. In particular, this is because the CF3 radical produced
from HFCs has negligible reactivity (Ravishankara et al., 1993); the
same radicals would be expected from HFO-1234yf. HFO-1234yf contains no
chlorine, bromine, or iodine. Also, the atmospheric lifetime of HFO-
1234yf is estimated at only 11 to 12 days (Orkin et al., 1997;
Papadimitrou et al., 2007), further reducing the amount of the chemical
that could possibly reach the stratosphere. Unsaturated HFCs, such as
HFO-1234yf, have at least one double bond or triple bond between two
carbon atoms. Double bonds, like those in HFO-1234yf, are less stable
than single bonds. A saturated HFC, such as HFC-134a, has only single
bonds between atoms of carbon, and is thus more stable. Although HFO-
1234yf may be more unstable than HFC-134a, EPA is not aware of any
chemical reactions or decomposition pathways that would cause HFO-
1234yf or its breakdown products to lead to ozone depletion and the
commenter has provided no technical or scientific support for their
claims. For purposes of our determination, whether its ODP is zero or
nearly zero, we expect HFO-1234yf to have negligible impact on the
ozone layer and we are listing it as acceptable, subject to use
conditions.
2. Global Warming Potential
Comment: Several commenters agreed with EPA's statement that HFO-
1234yf has a global warming potential (GWP) of 4 over a 100-year time
horizon. Some commenters noted the potential environmental benefits of
having a lower GWP refrigerant available. Other commenters stated that
HFO-1234yf would not be a solution to high global warming impacts
because of environmental and health impacts of breakdown products,
including HF, trifluoroacetic acid (TFA), and aldehydes.
Response: EPA continues to believe that the 100-yr GWP of HFO-
1234yf is 4, as supported by the commenters. We further agree with the
commenters who state that there will be an environmental benefit if car
manufacturers switch to HFO-1234yf from HFC-134a, a refrigerant with a
GWP of 1430 relative to CO2.
We disagree with the commenters who claim that environmental and
health impacts of breakdown products are a major cause for concern or
will prevent HFO-1234yf from being a useful solution to high global
warming impacts. One commenter mentioned concerns about HF in the
atmosphere, but HFO-1234yf does not decompose to form significant
amounts of HF in the atmosphere. In fact, HFC-134a and HFC-152a result
in more HF in the atmosphere than HFO-1234yf because those two
compounds decompose to form both COF2, carbonyl fluoride
(and then HF and CO2) and CF3COF, trifluoroacetyl
fluoride (and then TFA); in contrast, HFO-1234yf favors forming
trifluoroacetyl fluoride (and then TFA) and does not decompose to
carbonyl fluoride or to HF (ICF, 2010d). For a discussion on the
potential human health impacts of HF, see sections V and VII.D.3, ``Why
is EPA finding HFO-1234yf acceptable subject to use conditions?'' and
``Toxicity of Hydrogen Fluoride.''
The fluorinated breakdown product that we have identified of
greatest concern is TFA, because of its persistence and potential
impacts on aquatic plants. As discussed above in section V and below in
section VII.C.5, ``Formation of Trifluoroacetic Acid and Ecosystem
Impacts,'' the projected concentrations of TFA, based on a conservative
analysis, will be far below the level expected to cause any adverse
impacts on aquatic life.
EPA agrees that the breakdown products from the decomposition of
HFO-1234yf will include aldehydes, but we disagree that this is a cause
for concern. As part of the analysis of the atmospheric breakdown
products of HFO-1234yf, we found that worst-case concentrations of
formaldehyde would reach 6 to 8 parts per trillion (ppt) on a monthly
basis or an average of 3 ppt on an annual average basis, compared to a
health-based limit of 8000 ppt,\17\ i.e., a level that is roughly 1000
to 2600 times lower than the health-based limit (ICF, 2010d).
Acetaldehyde levels would be even lower, with worst-case concentrations
of 1.2 ppt and annual average concentrations of 0.23 ppt, compared to a
health-based limit of 5000 ppt \18\ (ICF, 2010d). As discussed further
below in section VII.D.1 of the preamble, ``Toxicity of HFO-1234yf,''
these concentrations are one to three orders of magnitude less than
ambient concentrations of formaldehyde and acetaldehyde without the
introduction of HFO-1234yf (ICF, 2010d). Thus, aldehydes that would be
decomposition products of HFO-1234yf in the atmosphere would not
contribute significantly to adverse health effects for people on
earth's surface.
---------------------------------------------------------------------------
\17\ The Agency for Toxic Substances and Disease Registry
(ATSDR) has established a chronic inhalation minimal risk level
(MRL) of 0.008 ppm (8,000 ppt) for formaldehyde (ICF, 2010d). MRLs
are available online at http://www.atsdr.cdc.gov/mrls/mrls_list.html.
\18\ EPA has established a Reference Concentration (RfC) of
0.005 ppm (5,000 ppt or 0.009 mg/m\3\) for acetaldehyde (ICF,
2010d). A summary of EPA's documentation for its risk assessment and
RfC derivation for acetaldehyde is available online at http://www.epa.gov/ncea/iris/subst/0290.htm.
---------------------------------------------------------------------------
Other fluorinated alternatives that are acceptable in the MVAC end-
use, HFC-134a and HFC-152a, also create fluorinated breakdown products,
and there is not evidence to show that those from HFO-1234yf create
significantly more risk for human health or the environment than
breakdown products from other alternatives. Thus, even assuming that
risks from breakdown products would exist, based on use of HFO-1234yf
in the MVAC end-use, we do not believe those risks are greater than the
risks posed by other acceptable alternatives.
3. Lifecycle Emissions of HFO-1234yf
Comment: One commenter stated that HFO-1234yf has the best global
lifecycle climate performance (LCCP) and lower CO2
[equivalent] emissions compared to other alternatives. However, another
commenter stated that HFO-1234yf has a lower thermodynamic efficiency
than HFC-134a and that its use could lead to increases in
CO2 and other air pollutant emissions. The same commenter
stated that there is no assurance that automakers would voluntarily add
technologies to maintain current levels of MVAC efficiency when using
HFO-1234yf.
Response: We note that EPA has chosen to use GWP as the primary
metric for climate impact for the SNAP program, while also considering
energy efficiency (March 18, 1994; 59 FR 13044). We have not used
specific lifecycle metrics such as Total Equivalent Warming Impact
(TEWI), Lifecycle Analysis (LCA) or LCCP as metrics for climate impact,
since it is not clear that there is agreement in all industrial sectors
or end-uses on which of these measures is most appropriate in which
situations or how these metrics are to be calculated (SROC, 2005).
The available information on efficiency, LCCP and lifecycle
emissions for MVAC does not raise concern that the indirect climate
impacts from HFO-1234yf will cause significantly greater impacts on
human health and the environment than other available alternatives.
Looking at some of the information referenced by the commenters, we
learned that:
Bench testing for the Japan Automobile Manufacturers
Association (JAMA) and the Japan
[[Page 17501]]
Auto Parts Industry Association (JAPIA) found a system efficiency
(coefficient of performance) for HFO-1234yf that is roughly 96% of that
for HFC-134a (JAMA-JAPIA, 2008)
LCCP analysis conducted by JAMA found that indirect
CO2 equivalent emissions from less efficient fuel usage due
to use of the MVAC system were a few percent higher for HFO-1234yf and
roughly 20 to 25% higher for CO2, compared to HFC-134a
(JAMA, 2008)
JAMA's LCCP analysis found that when both direct emissions of
refrigerant and indirect emissions from less efficient fuel usage are
considered, HFC-134a has higher total climate impact than either HFO-
1234yf or CO2; in hotter climates like Phoenix, Arizona,
HFC-134a has higher total climate impact than HFO-1234yf but slightly
lower climate impact than CO2; and in all cases, HFO-1234yf
had the lowest total climate impact of the three alternatives. (JAMA,
2008)
MVAC systems can be designed to improve efficiency through
steps such as changing the compressor, sealing the area around the air
inlet, changing the thermal expansion valve, improving the efficiency
of the internal heat exchanger, adding an oil separator to the
compressor, and changing the design of the evaporator. Optimized new
MVAC systems using either HFO-1234yf or CO2 can reduce fuel
usage compared to current MVAC systems using HFC-134a. (Benouali et
al., 2008; Meyer, 2008; Monforte et al., 2008)
EPA believes that there is good reason to expect that automobile
manufacturers will choose to design new cars using more efficient MVAC
components and systems than in the past because of recent regulations.
The Department of Transportation has issued new regulations raising the
Corporate Average Fuel Economy standards for vehicles and EPA has
issued new regulations restricting greenhouse gas emissions from light-
duty vehicles (75 FR 25324; May 7, 2010). Thus, in order to ensure that
their fleets meet these standards, it is highly likely that automobile
manufacturers will include MVAC systems optimized for efficiency in
future models, regardless of the refrigerant used.
Comment: Concerning an appropriate rate of emissions for estimating
environmental impacts of HFO-1234yf, three commenters recommended that
EPA use 50 g per vehicle per year total lifecycle emission rate. These
commenters cited the work of Wallington et al. (2008) and Papasavva et
al. (2009).\19\ Another commenter stated that HFO-1234yf is very likely
to have a lower leak rate than HFC-134a, citing data on permeability
for both refrigerants.
---------------------------------------------------------------------------
\19\ Papasavva et al. (2009) includes several sources of
emissions of automobile refrigerant, including regular leaks through
hoses, irregular leaks, refrigerant loss during servicing, and
refrigerant loss at end of vehicle life.
---------------------------------------------------------------------------
Response: EPA agrees that the permeability data indicate that
regular leakage emissions of HFO-1234yf, which are released slowly
through hoses, are likely to be lower than those from HFC-134a.
However, this is only a portion of total emissions expected because
emissions may also come through irregular leaks due to damage to the
MVAC system, refrigerant loss during servicing, and refrigerant loss at
the end of vehicle life. In response to the commenters who suggested
that we use an annual emission rate of 50 g/vehicle/yr, we reexamined
environmental impacts as part of our final environmental analysis (ICF,
2010c) using the recommended 50 g/vehicle/yr value and compared this to
the impacts calculated assuming emissions are similar to those from
HFC-134a in MVAC, as we did at the time of proposal (closer to 100 g/
vehicle/yr). The emission values from using 50 g/vehicle/yr (i.e.,
values from the Pappasavva et al. (2009) study) were 26.3% to 51.1%
less than the emission estimates used in our analysis at the time of
proposal (ICF, 2009; ICF, 2010a; ICF, 2010c). In either case, as
described more fully in section V above and in sections VII.C.4 and
VII.C.5, below, the overall environmental impacts on generation of
ground-level ozone and of TFA were sufficiently low and the impacts of
HFO-1234yf are not significantly greater than those of other available
substitutes for MVAC. For further information, see the ICF analyses in
the docket (ICF, 2010a,b,c,e).
4. Ground-Level Ozone Formation
Comment: Some commenters expressed concern about a potential
increase in ground-level ozone of > 1-4% calculated in EPA's initial
assessment (ICF, 2009) of environmental impacts of HFO-1234yf. Other
commenters stated that HFO-1234yf will not contribute significantly to
ground-level ozone. One commenter suggested that EPA provide an updated
assessment of the potential contribution of HFO-1234yf to ground-level
ozone, considering the additional information provided in public
comments (e.g., Luecken et al., 2009 and Wallington et al., 2009).\20\
---------------------------------------------------------------------------
\20\ Prepublication version of Wallington et al., 2010 (Docket
item EPA-HQ-OAR-2008-0664-0084.2)
---------------------------------------------------------------------------
Response: We proposed that HFO-1234yf would be acceptable, even
with a worst-case increase in ground-level ozone of > 1 to 4%. In
response to comments, EPA performed a new analysis that (1) used
revised estimates of the expected emissions of HFO-1234yf; and (2) used
reactions with ozone formation from hydroxyl radicals rather than using
sulfur dioxide (SO2) as a surrogate for the hydroxyl
radical, OH\-\, and rather than making assumptions about the relative
reactivity of compounds. Our revised analysis (ICF, 2010b) estimates
that emissions of HFO-1234yf might cause increases in ground-level
ozone of approximately 0.08 ppb or 0.1% of the ozone standard in the
worst case, rather than an increase of 1.4 to 4% as determined in our
initial analysis (ICF, 2009). This value also agrees with results from
Kajihara et al., 2010 and Luecken et al., 2009. This revised analysis
provides additional support that HFO-1234yf will not create significant
impacts on ground level ozone formation or on local air quality.
Comment: Some commenters disagreed with EPA's statement that HFO-
1234yf has a photochemical ozone creation potential (POCP) comparable
to that of ethylene (100), while others agreed with this conclusion.
One commenter provided a peer reviewed study that estimated the POCP of
HFO-1234yf to be 7 (Wallington et al., 2010).
Response: Based on the comments received and additional studies,
EPA believes that the initial assessment that assumed a POCP of 100 to
300 is overly conservative. We have revised our initial analysis to
incorporate reaction kinetics specific to HFO-1234yf, consistent with
Luecken et al., 2009, which avoids making an assumption of POCP. EPA's
revised analysis estimates worst-case increases in ground-level ozone
formation of approximately 0.1% (ICF, 2010b). Compared to the
uncertainty in the sources of emissions, the uncertainty in the
measures that localities will take to meet the ozone standard, and the
uncertainty in the analysis, a projected worst-case increase in ozone
of 0.1% is not significant for purposes of determining that HFO-1234yf
poses substantially greater human health or environmental risk than
other alternatives. This provides further support for our proposed
determination that the conditioned use of HFO-1234yf does not present a
[[Page 17502]]
significantly larger risk to human health and the environment compared
to HFC-134a, and in many cases likely poses less risk. For further
information, see the analysis of environmental impacts in section V of
the preamble, ``Why is EPA finding HFO-1234yf acceptable subject to use
conditions?'' and see the analysis in the docket (ICF, 2010b).
Comment: A commenter provided a link to a paper (Carter, 2009) that
found the maximum incremental reactivity (MIR) for HFO-1234yf to be
about the same as that for ethane. Based on the MIR value for HFO-
1234yf, some commenters stated that EPA should find HFO-1234yf to be
exempt from the definition of VOC.
Response: (Note: EPA has previously found certain compounds exempt
from the definition of ``volatile organic compound'' [VOC] for purposes
of air regulations in State Implementation Plans, 40 CFR 51.100(s), if
they have a MIR equal to or less than that of ethane on a mass basis
[69 FR 69298, November 29, 2004; 74 FR 29595, June 23, 2009; also see
interim EPA guidance at 70 FR 54046, September 13, 2005].) In a
separate rulemaking process, EPA is considering whether to list HFO-
1234yf under 40 CFR 51.100(s) as exempt from the definition of VOC for
purposes of air regulations that States may adopt in State
Implementation Plans.
5. Formation of Trifluoroacetic Acid and Ecosystem Impacts
Comment: Several commenters agreed with EPA's proposed finding that
the projected maximum concentration of TFA in rainwater from
degradation of HFO-1234yf does not pose a significant aquatic toxicity
risk. Other commenters raised concern about the potential impacts of
TFA on biodiversity, ecosystems, and human health. One commenter
questioned the sustainability of HFO-1234yf, so long as there are
questions remaining about its environmental fate and degradation. One
commenter stated that artificial input of TFA into the environment
should be avoided because of its toxicity and chemical properties.
Another commenter stated that HFO-1234yf poses additional environmental
concerns compared to HFC-134a and advised against finding it acceptable
while the issue of TFA production is being further researched.
Response: We continue to conclude for purposes of our decision here
that the degradation of HFO-1234yf into TFA does not pose a significant
risk of aquatic toxicity or ecosystem impacts. All available research
indicates that, assuming emissions are no more than twice the current
level of emissions from HFC-134a from MVAC, TFA concentrations in
surface water and rainwater will be on the order of 1/800th to 1/80th
of the no observed adverse effect level (NOAEL) for the most sensitive
known alga (Luecken et al., 2009; Kajihara et al., 2010). We have
revised our analysis on TFA concentrations using the known reaction
kinetics of HFO-1234yf. The revised estimate of the worst-case TFA
concentration in rainwater is approximately 1700 ng/L, similar to the
concentrations in Luecken et al. (2009) of 1260 ng/L and Kajihara et
al. (2010) of 450 ng/L. We believe this provides a sufficient margin of
protection to find that the use of HFO-1234yf in MVAC will not pose
significantly greater risks than other available alternatives in this
end-use.
Comment: Some commenters stated that further research on TFA is
necessary.
Response: EPA has considered additional studies submitted during
the public comment period (Luecken et al., 2009; Kajihara et al., 2010)
and has performed further analysis on this issue. Luecken et al. (2009)
predicted through modeling that in the U.S., HFO-1234yf used in MVAC
would result in enough TFA to increase its concentration in rainwater
to 1/80th to 1/800th of the NOAEL for the most sensitive plant species
considered. Kajihara et al. (2010) predicted through modeling that in
Japan, HFO-1234yf use in all potential refrigeration uses would
increase the TFA concentration in surface water to no more than 1/80th
of the NOAEL for the most sensitive plant species considered. This
study also found that surface water concentrations were roughly twice
those in rainwater. Thus, even with highly conservative modeling that
also considered accumulation in surface water, the concentrations of
TFA are likely to be at least 80 times lower than a level expected to
have no impact on the most sensitive aquatic species.
We also performed a further modeling analysis using refined
assumptions on emissions and the mechanisms by which HFO-1234yf might
break down. We found that the worst-case concentration of TFA would be
approximately 1700 ng/L, similar to the concentrations in Luecken et
al. (2009) of 1260 ng/L and Kajihara et al. (2010) of 450 ng/L (ICF,
2010b). These additional studies and analyses indicate even less risk
than the studies available at the time of proposal and thus provide
further support that TFA emissions from MVAC system will not pose a
significant risk of aquatic toxicity or ecosystem impacts.
We also note that EPA has an obligation to act on submissions in a
timely manner under the Clean Air Act (Sec. 612(d)). Given that
research to date has not indicated a significant risk, we disagree that
the Agency should delay a final decision to await further studies that
may be done in the future. If future studies indicate that HFO-1234yf
poses a significantly greater environmental risk than we now believe,
section 612(d) provides a process for an interested party to petition
the Agency to change a listing decision.
Comment: Two commenters stated that EPA's initial modeling (EPA-HQ-
OAR-2008-0664-0037) greatly overestimates the local deposition of TFA
from oxidation of HFO-1234yf. In particular, one commenter claimed that
the modeling's use of the oxidation of SO2 to sulfate ion,
SO3-, as a proxy for the oxidation of HFO-1234yf
is overly conservative because a large portion of SO2 is in
aerosol form, unlike for HFO-1234yf. This commenter also referred to
the impacts found in the peer-reviewed paper by Luecken et al. (2009).
Response: EPA agrees that the use of the oxidation of
SO2 to SO3- as a proxy for the
oxidation of HFO-1234yf likely results in overestimating TFA
concentrations. This is because the sulfate particle is a condensation
nucleus in the wet deposition process and it has a very high removal
efficiency compared to the gas phase process for wet deposition that
acts with HFO-1234yf and its decomposition products. Further, TFA forms
more slowly from HFO-1234yf than sulfate forms from SO2
(ICF, 2010b).
We have repeated the modeling using refined assumptions on
emissions and the mechanisms by which HFO-1234yf might break down. This
revised assessment (ICF, 2010b) found TFA concentrations roughly one-
thousandth those in the earlier assessment (1700 ng/L compared to
1,800,000 ng/L in ICF, 2009). This additional research provides
stronger support for our conclusion that the degradation of HFO-1234yf
into TFA does not pose a significant risk of aquatic toxicity or
ecosystem impacts.
Comment: Some commenters disagreed with a statement in the ICF
(2009) analysis concerning TFA concentrations in surface waters, that
``the exception to this is vernal pools and similar seasonal water
bodies that have no significant outflow capacity.'' These commenters
believe that Boutonnet et al. (1999) showed that accumulation of
trifluoroacetate, a compound closely related to TFA, was rather limited
in seasonal water bodies. The commenters also stated that Benesch et
al. (2002) conducted an
[[Page 17503]]
experimental study of the impacts of TFA on vernal pools, in which no
impacts were observed.
Response: The statement from ICF, 2009 in context stated:
NOECs [No-observed effect concentrations] were compared to
rainwater TFA concentrations because for most water bodies, it is
difficult to predict what the actual TFA concentration will be. This is
because concentrations of environmental contaminants in most fresh
water bodies fluctuate widely due to varying inputs and outputs to most
ponds, lakes, and streams. Comparison of NOECs to rainwater
concentrations of TFA is actually more conservative because TFA is
expected to be diluted in most freshwater bodies. The exception to this
is vernal pools and similar seasonal water bodies that have no
significant outflow capacity. (ICF, 2009)
We note that the ``exception'' described in the analysis is an
exception to the expectation that TFA will be diluted more in
freshwater bodies than in rainwater. We believe that the available
evidence confirms that vernal pools do not dilute TFA as much as
freshwater bodies with outflow capacity. Modeling by Kajihara et al.,
2010 found surface water concentrations were roughly twice those in
rainwater. However, even these concentrations were not high enough to
be of significant concern for environmental impacts. As noted
previously, even the highest levels of TFA concentrations were at least
80 times less than the NOAEL for the most sensitive aquatic species
examined.
D. Health and Safety Impacts
1. Toxicity of HFO-1234yf
Comment: Three commenters stated that there are no toxicity
concerns with using HFO-1234yf, and two commenters noted that HFO-
1234yf is comparable to HFC-134a in terms of human health effects. One
commenter also stated that HFO-1234yf does not present a developmental
toxicity or lethality risk. Seven commenters stated that there are
potential toxicity concerns with use of HFO-1234yf. One commenter
cautioned EPA against listing HFO-1234yf as acceptable for use in MVACs
on the grounds of increased concerns over developmental effects and
other toxic effects on human health.
Response: EPA continues to believe that HFO-1234yf, when used in
new MVAC systems in accordance with the use conditions in this final
rule, does not result in significantly greater risks to human health
than the use of other available or potentially available substitutes,
such as HFC-134a or CO2. The results of most of the toxicity
tests for HFO-1234yf either confirmed no observed adverse health
effects, or found health effects at similar or higher exposure levels
than for HFC-134a. For example, HFC-134a caused cardiac sensitization
at 75,000 ppm but HFO-1234yf did not cause cardiac sensitization even
at 120,000 ppm, the highest level in the study (NRC, 1996; WIL 2006).
NOAELs from subacute exposure were higher for HFO-1234yf than for HFC-
134a (NOAELs of 51,690 for HFO-1234yf with no effects seen in the
study, compared to 10,000 ppm for HFC-134a with lung lesions and
reproductive effects seen at 50,000 ppm [NRC, 1996; TNO, 2005]). No
adverse effects were seen at 50,000 ppm or any other level in
subchronic (13-week) studies for both HFO-1234yf and HFC-134a (NRC,
1996; TNO, 2007a).
In mutagenicity testing for HFO-1234yf, the two most sensitive of
five strains of bacteria showed mutation; however, this screening test
for carcinogenic potential is known to have only a weak correlation
with carcinogenicity (Parodi et al., 1982; \21\ Kirkland et al., 2005
\22\), so a positive result in this test for the two most sensitive
strains is not sufficient reason to consider HFO-1234yf to be a
significant health risk. Mutagenicity testing for HFC-134a by the same
test found no evidence of mutagenicity. Screening for carcinogenic
potential in a genomics study did not identify HFO-1234yf as a likely
carcinogen (Hamner Institutes, 2007). A two-year cancer assay for HFC-
134a did not find evidence of carcinogenicity (NRC, 1996).
---------------------------------------------------------------------------
\21\ Predictive ability of the autoradiographic repair assay in
rat liver cells compared with the Ames test; S. Parodi; M.
Taningher; C. Balbi; L. Santi; Journal of Toxicology and
Environmental Health, Vol. 10, Issue 4 & 5, October 1982, pages 531-
539.
\22\ Kirkland et al. (2005) Evaluation of a battery of three in
vitro genotoxicity tests to determine rodent carcinogens and non-
carcinogens. I. Sensitivity, specificity and relative predictivity,
Mutation Research, 584, 1-256.
---------------------------------------------------------------------------
EPA considers the results of developmental testing to date to be of
some concern, but not a sufficient basis to find HFO-1234yf
unacceptable for purposes of this action under the SNAP program. In a
developmental study on rats, cases of wavy ribs were seen in some
developing fetuses during exposure to HFO-1234yf (TNO 2007b); however,
effects on bone formation were also seen for HFC-134a (NRC, 1996). It
is not clear if this effect is reversible or not. Interim results from
a two-generation reproductive study did not find an association between
exposure to HFO-1234yf and skeletal effects. This two-generation
reproductive study for HFO-1234yf finds a NOAEL of 5000 ppm for delayed
mean time to vaginal opening in F1 females (females in the first
generation of offspring). A subacute (28-day) test for HFC-134a (single
generation) found a NOAEL of 10,000 ppm for male reproductive effects
(NRC, 1996). A developmental test on rabbits exposed to HFO-1234yf did
not find effects on the developing fetus. However, some of the mother
rabbits in this study died. The reason for the deaths is not known. The
data on developmental effects are inconsistent depending on the test
performed and the species tested. The development effects observed in
the developmental study on rats are not significantly different from
the developmental effects observed for HFC-134a. In any case, as
discussed above in section V and below in this section, our risk
assessments found that HFO-1234yf would likely be used with exposure
levels well below those of concern in the uses allowed under this rule.
Thus, we do not find the observed developmental effects sufficient
reason for finding HFO-1234yf unacceptable in this rule.
For purposes of this action, we prepared our risk assessment for
long-term exposure using the level at which no deaths or other adverse
health effects were seen in the rabbit developmental study--a ``no
observed adverse effect level'' or NOAEL--to ensure that exposed people
would be protected. The longer-term, repeated exposure in that study
would be the exposure pattern (though not necessarily the exposure
level) for a worker using HFO-1234yf on a regular basis or for a
consumer exposed in a car due to a long, slow leak into the passenger
compartment. Using the NOAEL concentration of 4000 ppm as a starting
point, we found no situations where we expect exposure to exceed the
level that EPA considers safe for long-term or repeated exposure (EPA-
HQ-OAR-2008-0664-0036). Thus, we consider the potential toxicity risks
of HFO-1234yf for those uses allowed under this action to be addressed
sufficiently to list it as acceptable subject to use conditions.
Comment: Based on a risk assessment conducted by one commenter, the
commenter concluded that if HFO-1234yf is used under the conditions
specified in the commenter's risk assessment, adverse health impacts
would not be expected to car occupants, to servicing personnel, or to
do-it-yourself (DIY) consumers. This commenter noted differences
between the margin-of-exposure approach to
[[Page 17504]]
assessing risk, as in EPA's risk assessment (EPA-HQ-OAR-2008-0664-
0036), and the commenter's hazard index (HI) approach. The commenter
further stated that in all cases, the predicted hazard index for HFO-
1234yf was only one-half of the values predicted for HFC-134a, and in
some cases, only one-third of the HFC-134a values, demonstrating from a
health perspective that HFO-1234yf is a viable alternative to HFC-134a.
Response: EPA agrees that adverse health impacts would not be
expected to car occupants or to servicing personnel, so long as the use
conditions of this rule are observed. However, EPA has issued a
Significant New Use Rule under TSCA (October 27, 2010; 75 FR 65987)
that would require submission of additional information to EPA prior to
the manufacture, import or processing of HFO-1234yf for certain uses,
including distribution in commerce of products intended for use by a
consumer for the purposes of servicing, maintenance and disposal
involving HFO-1234yf (e.g., ``do-it-yourself'' servicing of MVAC
systems).
Where available, it is EPA policy to use a NOAEL (No-Observed-
Adverse-Effect Level) for the point of departure (POD) for risk
assessment. This is the highest exposure level that did not cause an
adverse health effect in a study. In this case, EPA selected the POD
from an animal (rat 2-week inhalation) study. Because animals may
respond to different exposure levels than humans, there is some
uncertainty when extrapolating from animals to humans. For this reason,
an Uncertainty Factor (UF) is applied when extrapolating from animals
to humans--typically a factor of 10 is used but, in this case, since
there was a reasonable estimate of the pharmacokinetic component of the
uncertainty, this UF was reduced to 3. An additional UF is applied to
account for variation in the human population response to a chemical
exposure--in this case, a UF of 10 was used. The two UFs give a
resultant UF of 30 to yield an acceptable level of health risk. As
stated in the final SNUR, EPA's policy for review of new chemicals
under TSCA is to divide the POD by the exposure level to obtain the
MOE. For HFO-1234yf, the ``acceptable level of health risk'' would be
an MOE of 30 or greater.
The commenter proposed dividing the estimated exposure to HFO-
1234yf by the POD levels to obtain a HI. As a result, if the exposure
is less than the POD, the HI is < 1 and the commenter considered this
an ``acceptable level of health risk.'' The commenter's approach to the
hazard index does not factor in uncertainties about extrapolating from
animal to human responses, nor does it address variability within the
human population with regard to thresholds of response to chemical
exposures. EPA has consistently applied the margin of exposure (MOE)
approach to evaluations of pre-manufacture notices (and for certain
other risk assessments) in order to account for the uncertainties
discussed above. The SNAP program considered work performed during
evaluation of the pre-manufacture notice (EPA-HQ-OAR-2008-0664-0036),
as well as a separate SNAP program risk screen (EPA-HQ-OAR-2008-0664-
0038). SNAP program risk screens compare expected exposures to exposure
limits that incorporate uncertainty factors based on EPA guidance,
rather than calculating either a hazard index or a margin of exposure.
Any of these approaches to risk assessment will come to a similar
conclusion about whether there is a potential health concern when using
the same point of departure, uncertainty factors, and exposure
estimates.
The Agency and the commenter disagree on all three of these inputs
to the risk assessment and hence have reached different conclusions.
Despite these differences, the assessments relied on by both the
commenter and EPA show that there is low risk both to car occupants and
to service technicians. EPA's risk assessment indicates a potential
risk to DIYers (EPA-HQ-OAR-2008-0664-0036). As stated previously in
this action, this issue is further addressed through the Agency's
authority under TSCA.
Comment: In response to EPA's risk assessment (EPA-HQ-OAR-2008-
0664-0036), two commenters disagreed with the use of a 2-week study for
evaluating 30 minute exposures and stated that acute toxicity (4-hour
test) or cardiac sensitization test results would be more appropriate
for acute exposure evaluations.
Response: Commenters have suggested that EPA use data from the 4-
hour acute toxicity study or from the cardiac sensitization study as a
starting point (``point of departure'') for assessing risks of short-
term (acute) exposure. However, cardiac sensitization studies are for
very short durations--on the order of 10 minutes--and they only address
cardiac sensitization. HFO-1234yf does not induce cardiac
sensitization. EPA selected the point of departure for acute effects
from a multiple-exposure 2-week (subacute) rat inhalation study on HFO-
1234yf, reasoning that if no effects were seen in the duration of the
study (6 hours per day, 5 days per week for 2 weeks), that no effects
would be seen from a single exposure at a similar exposure level,
either. Further, the subacute exposure rat study included more thorough
pathology examinations than those included in a cardiac sensitization
study.
The acute 4-hour exposure study in rats showed some lung effects at
approximately 200,000 ppm, the lowest exposure level in the study. Thus
EPA considers 200,000 ppm to be a LOAEL (Low-Observed-Adverse-Effect
Level). If a LOAEL were used in the risk assessment instead of a NOAEL,
EPA would use an uncertainty factor to estimate a NOAEL, which would
result in a lower POD than what was used. For example, if EPA had
started with the LOAEL of 200,000 ppm, it would have required an
additional MOE of 10 to estimate a NOAEL from a LOAEL, for a total MOE
of 300 instead of 30. This would have resulted in a more conservative
risk assessment than using the NOAEL from the 14-day subacute study. In
the 4-hour acute toxicity study, some of the animals had grey,
discolored lungs at all exposure levels in the study, and we considered
this an adverse effect. Thus, EPA could only determine a lowest
observed adverse effect level (LOAEL) from the 4-hour acute study and
could not determine a no observed adverse effect level (NOAEL). It is
longstanding Agency policy to use the NOAEL where available instead of
a LOAEL, because of greater assurance of a safe exposure level. EPA
instead used the NOAEL for the next shortest study, the subacute 14-day
study, as the endpoint of concern for short term exposure because the
LOAEL from the acute 4-hour study is an endpoint showing effects that
may not result in safe exposure levels for humans. If we had used the
value from the 4-hour acute toxicity study, we would have had to
consider additional uncertainty that would have resulted in a more
conservative, more restrictive risk assessment than using the NOAEL
from the 14-day subacute study.
Further, EPA has uncertainties about using the available single
exposure studies on HFO-1234yf to determine the MOEs for different
exposure scenarios. As a result of concerns with these studies, EPA
calculated single exposure MOEs from the NOAEL in the 2-week inhalation
toxicity study of HFO-1234yf in rats. There are some uncertainties in
the single exposure (acute) assessments because of the observation of
lethality in rabbit dams after multiple exposures to HFO-1234yf in a
developmental study. For these reasons, EPA recommended an acute
inhalation toxicity study on rabbits in the proposed SNUR to address
[[Page 17505]]
the question of whether pregnant rabbits would die from a single
exposure (April 2, 2010; 75 FR 16706).
Comment: A commenter asserted that EPA's methodology to estimate
the exposure levels associated with the DIY use, using the SAE CRP
(2008) Phase II Report, greatly exaggerates the exposure that could be
experienced in actual use conditions. Another commenter calculated
exposure to a DIYer assuming that the refrigerant fills a garage and
concluded that exposure would be less than the manufacturer's
recommended exposure limit of 1000 ppm. The first commenter stated that
the 30 minute time-weighted average (TWA) value used by the EPA is
unrealistic as are the exposure estimates presented in Scenarios 1 and
2 of the supporting document EPA-HQ-OAR-2008-0664-0036. The specific
exposure parameters that the commenters questioned were assumptions
regarding:
Garage volume;
Time the user spent under the hood during recharging
operations;
The size of the space where any leaking gas would
disperse;
The air exchange rate in a service area that should be
well-ventilated when the engine is running;
Use of the refrigerant in a closed garage with no
ventilation; and,
The amount of refrigerant used during recharge operations.
During the comment period for the proposed SNUR, the PMN and SNAP
submitter conducted a simulated vehicle service leak testing, using
HFC-134a as a surrogate, indicating that exposures from use of a 12-oz
can during consumer DIY use are below the Agency's level of concern for
HFO-1234yf (Honeywell, 2010a).
Response: Concerning exposure estimates for DIYers, the exposure
values in the EPA risk assessment (EPA-HQ-OAR-2008-0664-0036) are
bounding estimates of the maximum possible theoretical concentrations.
The EPA assessment used the industry-modeled DIY scenarios and
assumptions in a 2008 report by Gradient Corporation for the SAE CRP
(CRP, 2008) as a starting point for creating the bounding estimates. To
do so, EPA assumed that the entire leakage mass of each industry-
modeled scenario was released to its corresponding volume with no air
exchange. These assumptions are conservative and protective, as
intended.
We considered the calculations provided by one commenter that
assumed that the refrigerant fills a garage. However, this analysis
assumes a longer-term, steady-state concentration after the refrigerant
has diffused throughout the garage and uses a long-term, 8-hour time-
weighted average exposure recommendation for comparison. EPA's concerns
about DIY consumer exposure focuses on short-term acute exposures,
including peak exposures over a few minutes near the consumer's mouth
and nose because typically a DIY consumer will only need a short period
of time to recharge a single MVAC system (Clodic et al., 2008). Thus,
the commenter's calculations do not address EPA's concerns.
After reviewing the consumer DIY use exposure study from the SNAP/
PMN submitter, EPA responded with a list of clarifying questions (U.S.
EPA, 2010c), to which the submitter subsequently responded (Honeywell,
2010b). Although the submitter's responses were helpful, EPA still has
concerns about potential exposures to consumers during DIY use and the
inherent toxicity of HFO-1234yf. However, since this acceptability
determination is limited to use with fittings for large containers,
which DIYers would not purchase, our concerns about potential health
risk to DIY users need not be addressed in this action. We would plan
to evaluate this issue further before taking a final action on a SNAP
submission for unique fittings for small containers. We further note
that the Agency would analyze this issue in the context of any SNUN
filed pursuant to the recently issued SNUR (75 FR 65987). Although we
do not reach any conclusion in this final rule regarding safe use by
DIYers, we make the following observations about the submitted study.
With regards to exposure, the peak concentration values from the
submitted study are as high as 3% by volume, equivalent to 30,000 ppm.
These peaks appeared to occur in the first one or two minutes of each
emission. Accordingly, EPA would need exposure data presented and
averaged out over shorter Time Weighted Averages (TWAs) than the 30
minutes currently in the study, because it would appear that a number
of these early exposure peaks could result in TWA values that would
result in MOEs less than the acceptable Agency level of 30 described
above in this section. This is important because the data on HFO-1234yf
are insufficient to differentiate whether the toxicity is due to blood
level alone from an acute exposure, is due to accumulated exposure over
time (``area under the curve''), or is due to some combination of both.
Since blood equilibrium levels are reached within minutes, a high level
of exposure in a short duration could result in blood levels exceeding
a threshold if the mode of action of the toxicity of HFO-1234yf is due
to blood levels of the chemical. EPA expects that exposure data with
additional TWAs of 3, 5, and 10 minutes would help to resolve these
issues of consumer exposure.
Comment: One commenter stated that HFOs could harm the human
nervous system. The commenter cited a diagram of breakdown products in
a slide presentation given by the Montreal Protocol Scientific
Assessment Panel in July 2009 and suggested that the toxic impact of
aldehydes formed as breakdown products would be higher than that of
carbonic acids.
Response: EPA agrees that the breakdown products from the
decomposition of HFO-1234yf will include aldehydes, but we disagree
that this is a cause for concern. The aldehydes that would be produced
as atmospheric breakdown products of HFO-1234yf are formaldehyde and
acetaldehyde (ICF, 2010d). Their health effects include respiratory
effects; irritation of the eyes, nose, and throat; and corrosion of the
gastrointestinal tract. EPA also considers formaldehyde and
acetaldehyde to be probable human carcinogens (U.S. EPA, 2000; ICF,
2010d). The decomposition products of HFO-1234yf are not noted for
causing neurotoxic effects, and toxicity tests for HFO-1234yf did not
identify this as an effect.
As part of analysis of the atmospheric breakdown products of HFO-
1234yf, we found that worst-case concentrations of formaldehyde would
reach 6 to 8 parts per trillion (ppt) on a monthly basis or an average
of 3 ppt on an annual average basis, compared to a health-based limit
of 8000 ppt \23\--i.e., a level that is roughly 1000 to 2600 times
lower than the health-based limit (ICF, 2010d). Acetaldehyde levels
would be even lower, with worst-case concentrations of 1.2 ppt and
annual average concentrations of 0.23 ppt, compared to a health-based
limit of 5000 ppt \24\ (ICF, 2010d). Thus, aldehydes that would be
decomposition products of HFO-1234yf in the atmosphere would not
contribute significantly to adverse human health effects (ICF, 2010d).
---------------------------------------------------------------------------
\23\ The Agency for Toxic Substances and Disease Registry
(ATSDR) has established a chronic inhalation minimal risk level
(MRL) of 0.008 ppm (8,000 ppt) for formaldehyde (ICF, 2010d). MRLs
are available at http://www.atsdr.cdc.gov/mrls/mrls_list.html.
\24\ EPA has established a Reference Concentration (RfC) of
0.005 ppm (5,000 ppt or 0.009 mg/m\3\) for acetaldehyde (ICF,
2010d). A summary of EPA's documentation for its risk assessment and
RfC derivation for acetaldehyde is available online at http://www.epa.gov/ncea/iris/subst/0290.htm.
---------------------------------------------------------------------------
Aldehydes, including formaldehyde and acetaldehyde, are already
present in
[[Page 17506]]
the atmosphere in significant amounts from natural sources such as
plants, from direct emissions, from combustion products, or from
breakdown of other compounds such as hydrocarbons (NRC, 1981; Rhasa and
Zellner, 1987). The current background level of formaldehyde in the
atmosphere ranges from 80 ppt in pristine areas to approximately 3300
ppt in New York, NY--one to three orders of magnitude more than the
worst-case generation of formaldehyde from HFO-1234yf (ICF, 2010d). The
maximum incremental acetaldehyde concentration calculated due to use of
HFO-1234yf was approximately three orders of magnitude less than the
average concentration of acetaldehyde in areas with pristine air
quality (ICF, 2010d). Thus, the additional aldehydes created during
decomposition of HFO-1234yf in the atmosphere are not likely to have a
significant impact on human health.
Comment: Some commenters stated that additional research and review
of the available information regarding toxicity of HFO-1234yf needs to
be conducted.
Response: EPA has an obligation to act on submissions in a timely
manner under the Act (Sec. 612(d)). Our risk assessments to date have
found no significant risk for car passengers or drivers, professional
servicing personnel, or workers disposing of or recycling vehicles
containing HFO-1234yf. We believe these assessments are sufficient to
support this action. We note that these assessments rely on somewhat
conservative assumptions.
We note that we expect there will be no toxicity risks to DIYers
because EPA must receive and take regulatory action to allow unique
fittings for use with small cans of refrigerant before DIYers could be
exposed, as per appendix D to subpart G of 40 CFR part 82. Further,
because HFO-1234yf is not expected to be introduced into any new cars
until late 2011 or later, we expect to have further information and to
take further action before DIYers could be exposed. In addition, the
final SNUR would not allow distribution in commerce of products
intended for use by a consumer for the purposes of servicing,
maintenance and disposal involving HFO-1234yf until at least 90 days
after submission of a SNUN.
We recognize that more studies will be performed on HFO-1234yf,
further addressing risk. EPA's New Chemicals Program has recommended
additional testing of acute exposure in rabbits, including pregnant
rabbits (April 2, 2010; 75 FR 16706). In addition, the manufacturer is
voluntarily conducting a multi-generation reproductive study. If these
or other future studies call into question the basis for our decision
today, section 612 allows citizens to petition EPA to change or modify
a listing decision or EPA could determine on its own to reassess this
decision.
Comment: In late comments, a commenter stated that EPA appears to
be relying on a SNUR to reduce risks to human health from exposure to
HFO-1234yf. This commenter stated that EPA must re-open the comment
period on the proposed SNAP rule so that commenters may reassess the
extent to which the final restrictions of the SNUR will be effective at
limiting adverse human health effects. The same commenter noted that
information on new price levels and availability is needed to assess
the effectiveness of the SNUR.
Response: EPA's final SNUR addresses potential risks to human
health from exposure to HFO-1234yf. However, as discussed above in
section V of the preamble, ``Why is EPA listing HFO-1234yf as
acceptable subject to use conditions?'', this final SNAP rule does not
allow for the use of HFO-1234yf with small cans or containers (i.e.,
container sizes that would be purchased by DIY users, such as small
cans and containers less than 5 lbs) because it does not contain
specifications for unique fittings for can taps and for these smaller
containers. Existing SNAP program regulations in appendix D to subpart
G of 40 CFR part 82 require the use of unique fittings for specific
purposes (e.g., high pressure-side service port, small can taps) for
each MVAC refrigerant, as submitted by the refrigerant manufacturer.
Before HFO-1234yf can be introduced in small containers typically used
by DIYers, the manufacturer must submit unique fittings to EPA, we must
conclude that they are unique, and we must issue new proposed and final
rules specifying those fittings. In addition, the final SNUR would not
allow distribution in commerce of products intended for use by a
consumer for the purposes of servicing, maintenance and disposal
involving HFO-1234yf until at least 90 days after submission of a SNUN.
These and other requirements ensure--to the extent possible, with the
information currently available to EPA--that HFO-1234yf has no greater
risk overall for human health and the environment than other available
refrigerants for MVAC.
Under the final SNUR, it is necessary for EPA to receive and
complete its review of a significant new use notice (SNUN) with
additional information on consumer exposure risks before--if the Agency
so decides--HFO-1234yf may be manufactured, imported or processed for
the purpose of use in DIY servicing, with or without other
restrictions. We would also consider information in the SNUN before
issuing a final rule specifying unique fittings for use with small
containers of refrigerant.
In comments EPA received on the proposed SNAP rule, the initial
direct final SNUR that was withdrawn and the proposed SNUR, no
commenters suggested making the provisions of the SNUR stricter or
suggested adding use conditions under the SNAP program for addressing
risks to consumers during DIY servicing. A number of commenters stated
that no restrictions were needed to address risks to consumers during
DIY servicing, while other commenters stated more broadly that EPA
should find HFO-1234yf unacceptable because of its toxicity risks. We
provided an additional opportunity for comment on the SNAP rule after
the direct final SNUR was issued (February 1, 2010; 75 FR 4083), in
response to a request to reopen the public comment period (EPA-HQ-OAR-
2008-0664-0077.1), in part to allow comment on the relationship between
these two rulemakings that both address HFO-1234yf. However, we do not
believe that the conditions of the final SNUR are necessary to the
determination that we are making here. As noted above, this final rule
does not allow for the servicing of HFO-1234yf from container sizes
that would be purchased by DIY users because of the lack of an approved
unique fitting for smaller containers. Further rulemaking under SNAP
will occur prior to such use and any risks can be addressed in that
rulemaking package. At that time, we will be able to fully consider the
impact of the final SNUR.
2. Flammability
Comment: Five commenters stated that HFO-1234yf has a low
likelihood of ignition, especially under the conditions encountered in
an automotive application. One commenter stated that the mere presence
of high refrigerant concentrations does not contribute to a hazardous
condition because an ignition source of sufficient energy must also be
present. Another commenter disagreed with EPA's view that a
flammability risk exists. Other commenters stated that additional
review of the available information regarding flammability of HFO-
1234yf needs to be conducted. Some commenters stated that EPA should
consider restricting concentrations of HFO-1234yf to much lower
concentrations than to the lower flammability limit (LFL) of 6.2%.
Response: The available evidence indicates that HFO-1234yf will not
[[Page 17507]]
present a significant risk of flammability and that any risk it poses
is not greater than the risk presented by other available alternatives.
For example, because of its higher LFL, its considerably higher minimum
ignition energy (5000 mJ to 10,000 mJ), and its slower flame speed (1.5
cm/s), HFO-1234yf is less flammable than HFC-152a, a substitute that
EPA has already found acceptable subject to use conditions.
Further, an analysis conducted for SAE International's Cooperative
Research Program by Gradient Corporation (CRP, 2009) found that there
was a very low flammability risk (on order of 10-14
occurrences per operating hour or 1 occurrence in 100 years across the
entire U.S. fleet of passenger vehicles). This was due to the low
probability of achieving a concentration of HFO-1234yf above the LFL at
the same time as having a sufficiently high energy source to cause the
refrigerant to ignite. Further, even that low probability of ignition
of HFO-1234yf may be overstated, because it assumes that a vehicle
collision severe enough to crack open the evaporator (located under the
windshield and steering wheel) is not severe enough to crack the
windshield or windows that would hold refrigerant in the passenger
compartment. In a sensitivity analysis, the SAE CRP considered how the
flammability risk would change if a refrigerant release into the
passenger compartment only occurs in a collision causing damage to more
than the MVAC system. That analysis estimated that the risk of exposure
to an open flame would then be reduced by a factor of 23,000, to
approximately 4 x 10-19 occurrences per vehicle operating
hour (EPA-HQ-OAR-2008-0664-0056.2).
For the reasons provided above in sections IV and VII.B of the
preamble, ``What are the final use conditions and why did EPA finalize
these use conditions?'' and ``Use conditions,'' EPA does not believe it
is necessary to establish a use condition limiting refrigerant
concentrations, whether at 6.2% or some other, lower value. We believe
the final use conditions sufficiently address flammability risks.
Comment: Three commenters stated that HFO-1234yf is flammable and
that the proposed regulation does not offer any restrictions to protect
those persons handling HFO-1234yf, nor does it restrict its sale and
use by the general public.
Response: The purpose of the use conditions is to ensure that HFO-
1234yf will not pose a greater risk to human health or the environment
than other available or potentially available substitutes. For all of
the reasons provided in sections IV and V above, EPA has determined
that HFO-1234yf will not pose a greater risk than other substitutes for
MVAC. As explained above, EPA proposed restricting concentrations of
the refrigerant below the LFL of 6.2% as a use condition. Based on
comments and additional analysis, EPA has concluded that it is not
necessary to require use conditions limiting refrigerant concentrations
to below the LFL; rather, the use conditions now specify design
parameters for MVAC systems and require an FMEA. This will ensure that
systems are designed to minimize risk not only from flammability, but
also from exposure to HF.
We will address use by service personnel through a rulemaking under
section 609 of the CAA. Although these rules will further address
issues of interest to service personnel and others that might handle
HFO-1234yf used in MVAC systems, we note that our risk assessments of
use of HFO-1234yf found that significant flammability risks do not
exist for personnel installing the refrigerant at equipment
manufacture, professional servicing personnel, and personnel working
with automobiles at equipment end-of-life (EPA-HQ-OAR-2008-0664-0036
and -0038). Moreover, we note that an industry-sponsored analysis of
risks found the risk of ignition of HFO-1234yf to a technician is
extremely small, on the order of 10-26 occurrences per
working hour (EPA-HQ-OAR-2008-0664-0056.2).
As we have explained above, this rule only addresses the use of
large containers for professional use (typically 20 lbs or larger) and
thus HFO-1234yf may not be used in small container sizes that would be
the type purchased by the general public. We will address the issue of
risk to DIY users through a future rulemaking under SNAP if we receive
a request for unique fittings for smaller containers from the
refrigerant manufacturer. We also are addressing risks to DIY users
through the Significant New Use Rule under the Toxic Substances Control
Act (October 27, 2010; 75 FR 65987).
Comment: One commenter stated that compared with HFC-134a, the
explosion probability of HFO-1234yf is much higher based on testing
done at the Federal Institute for Materials Research and Testing
(Bundesanstalt f[uuml]r Materialforschung und-pr[uuml]fung, BAM). Other
commenters disagreed with those flammability conclusions, finding the
testing results to be expected but not representative of real-world use
in MVAC. These commenters stated that the flammability risks of HFO-
1234yf were not significant and that the mixtures of HFO-1234yf and
ethane used in the testing would not be seen in MVAC in actual
operations.
Response: As explained above in section VII.B, we do not believe
that these tests are relevant for assessing the flammability risks of
HFO-1234yf as used in MVAC systems because they evaluated flammability
based on the presence of ethane, a substance that should not be present
in any situation that might cause flammability risks for MVAC systems.
3. Toxicity of Hydrogen Fluoride (HF)
Comment: Two commenters stated that there is low risk due to
exposure to HF. One of these commenters stated that (1) for vehicles
that do not discontinue the use of the blower after collision, the risk
due to exposure to HF from use of HFO-1234yf is approximately twice the
risk with the current use of HFC-134a, and (2) for vehicles that
discontinue the use of the blower after collision, the risk due to
exposure to HF when using HFO-1234yf is approximately the same as that
with the current use of HFC-134a (on order of 10-12
occurrences per operating hour, or one in one trillion). The second
commenter stated that there is no need for concentration limits to
protect against exposure to HF because the risks from exposure to HF
from HFO-1234yf are similar to what would be experienced with HFC-134a.
One commenter also stated that concentrations of HF as low as 0.3 ppm
cause a sensation of irritation. The commenter stated that this
characteristic would deter someone from remaining exposed to excessive
concentrations from an open hood.
Other commenters stated that there is a high probability of HF
generation in cars from HFO-1234yf. One commenter stated that the
flammability of HFO-1234yf makes the production of HF more likely and
increases the risk of HF exposure to vehicle passengers, to workers at
chemical facilities, automotive manufacturing facilities, vehicle
servicing facilities, and to the general public. Two commenters stated
that various health and safety concerns related to HF generation and
its toxicity are well studied and documented, and three commenters
stated that use of HFO-1234yf is unacceptable as there is increased
potential for HF exposure and related casualties.
Response: EPA has considered the potential for generation of HF
from HFO-1234yf, including the SAE CRP's evaluation of scenarios that
might cause workplace and consumer exposure to HF (EPA-HQ-OAR-2008-
0664-0056.2). SAE CRP members conducted
[[Page 17508]]
tests to measure HF concentrations and to identify factors that were
most likely to lead to HF formation. One set of tests conducted in a
car found that HF measurements inside the passenger cabin were 35 ppm
or less (EPA-HQ-OAR-2008-0664-0056.2). This highest value occurred
during release of the entire charge of refrigerant of 1000 g into the
passenger cabin with ignition started by a butane lighter augmented
with an additional spark--a highly conservative scenario. (A more
typical charge would be 575 g, and it would be unlikely to have the
amount of ignition energy that occurred artificially in the experiment
with use of both a butane lighter and an additional spark source.) A
second set of tests focusing on HF in the engine compartment tried to
simulate a major rupture in the AC system that would release 12 g/s of
refrigerant across 5 cm onto an artificial hot surface at temperatures
of 450 [deg]C (typical of the exhaust manifold) and 700 [deg]C (most
extreme case), with the car hood in various positions. This testing
found HF concentrations as high as 120 ppm at the hot surface in the
engine compartment in the worst case, with interior passenger cabin
values of 40 to 80 ppm in the worst case (EPA-HQ-OAR-2008-0664-0056.2).
This test was conservative for the following reasons: The temperature
was high, representing extreme conditions; the refrigerant was released
extremely close to the hot surface; the hood was closed; and the
refrigerant ignited briefly. The other test trials under less extreme
conditions resulted in HF concentrations of a few ppm. The test trials
also found somewhat lower concentrations of HF generated during testing
of HFC-134a using the same procedures and apparatus, with maximum
concentration of 36 ppm in the engine compartment and concentrations of
less than 8 ppm in the passenger compartment in the worst case. The SAE
CRP selected an Acute Exposure Guideline Limit (AEGL)-2 \25\ of 95 ppm
over 10 minutes as its criterion for determining excessive risk. This
limit was developed to protect against irreversible health effects when
exposure remains below the limit of 95 ppm over 10 minutes, but short-
term discomfort or irritation could still occur. Thus, even assuming a
passenger inside a vehicle was exposed to HF at the highest level found
in the test of 80 ppm, exposure at this level would at worst cause
discomfort and irritation, rather than permanent or disabling health
effects.
---------------------------------------------------------------------------
\25\ An AEGL-2 is intended to apply to an emergency situation
where someone would try to move away from the hazard in a short
period of time and may suffer some temporary irritation, but no
permanent health damage. Irreversible or disabling but non-fatal
health effects could occur between the AEGL-2 and the higher AEGL-3.
---------------------------------------------------------------------------
For both HFO-1234yf and for HFC-134a, HF concentrations in the
passenger compartment fell between the level that would protect against
all adverse health effects (AEGL-1 of 1.0 ppm for 10 minutes to 8
hours) and the level that would protect against irreversible or
disabling health effects (AEGL-2 of 95 ppm over 10 minutes) (NRC,
2004). The SAE CRP concluded that the probability of such a worst case
event is on the order of 10-12 occurrences per operating
hour (EPA-HQ-OAR-2008-0664-0056.2). Commenters provided information
indicating that this level of risk for HF generation is the same order
of magnitude for both HFC-134a and for HFO-1234yf. EPA considers the
risk level presented by HFO-1234yf to be similar to that of the
refrigerant currently being used by automobile manufacturers, HFC-134a.
Therefore, there is no reason to regulate HFO-1234yf more stringently
to protect against HF exposure than for HFC-134a.
Comment: One commenter stated that testing with HFOs commissioned
by the environmental organization Greenpeace in 2001 hinted at a
multitude of decomposition products with high reactivity. The commenter
stated that apparently even lubricants (polyalkylene glycol--PAG) break
down to HF when in contact with HFO-1234yf in a MVAC system. The
commenter further expressed that BAM testing showed that burning HFO-
1234yf resulted in concentrations of HF greater than 90 ppm in the
engine compartment. The commenter concluded that the tests prove that
in a standard system with standard charge (900 grams) and oil, the risk
for humans would be incalculable.
Response: The commenter has not provided sufficient information on
the testing commissioned by Greenpeace in 2001 for the Agency to
determine what the results were or whether the testing conditions are
relevant to this action. Concerning the BAM testing, EPA has not seen a
testing report or a detailed description of the experimental method
that allows for a full evaluation. Based on the information provided by
the commenter, the temperature of the released substance reached 600
[deg]C and HF concentrations of over 90 ppm were measured in the engine
compartment. According to a risk assessment from an automobile
manufacturer, such a high temperature is unlikely and could only be
achieved on the exhaust manifold under heavy engine loads such as when
a vehicle is climbing a hill, and the temperature of the exhaust
manifold would drop in a minute or so during deceleration (EPA-HQ-OAR-
2008-0664-0081.1). It is not clear what the conditions were for the
study mentioned by the commenter. For example, it is not clear if the
refrigerant was mixed with compressor oil as it normally would be in an
MVAC; inclusion of oil with a relatively low flashpoint would be
expected to lead to ignition at lower temperatures (EPA-HQ-OAR-2008-
0664-0056.2; EPA-HQ-OAR-2008-0664-0118.1). It also is not clear if the
compressor fan was operating during the test. During normal vehicle
operation, the fan would cool down the compressor and the engine
compartment, avoiding the temperature of 600 [deg]C on hot surfaces in
the engine.
Other tests have found that HF concentrations in the engine
compartment were approximately 5 ppm or less and only in the worst case
(hot surface temperature of 700 [deg]C, closed hood on engine
compartment) did HF concentrations attain a value of approximately 120
ppm in the engine compartment (OAR-2008-0664-0056.2). This level is
slightly higher than the AEGL-2 of 95 ppm on a 10-minute average and is
lower than the AEGL-3 for HF of 170 ppm on a 10-minute average, the
value that would protect against life-threatening exposure but would
not necessarily prevent long-term health effects. However, we note that
we do not anticipate any circumstance where a person would be exposed
to these levels in an engine compartment because such conditions would
not occur during vehicle servicing, but rather during vehicle
operation. Further, in the case of a collision resulting in a fire, we
would expect that professional first responders have training in
chemical hazards and possess appropriate gear which would prevent them
from receiving HF exposures above health-based limits (EPA-HQ-OAR-2008-
0664-0056.2) and an interested by-stander would quickly back away from
a fire or from irritating HF vapors, thus preventing excessive HF
exposure. The concentration measured in the passenger compartment in
the same worst-case situation was in the range of 40 to 80 ppm, less
than the concentration in the engine compartment and less than the
AEGL-2 intended to protect against long-term health effects. Thus, we
disagree with the commenter's assertion that HF exposures from thermal
decomposition or combustion of refrigerant would be likely to result in
fatalities. We further
[[Page 17509]]
note that the HF concentrations found in the passenger compartment were
lower than the health-based limit, the AEGL-2 of 95 ppm over 10
minutes.
We also note that the risks presented by HFO-1234yf are not
significantly different than the risk posed by HFC-134a, the
refrigerant currently in use in MVAC systems. Mixtures of HFC-134a and
compressor oil also combust and generate HF. Testing performed using
HFC-134a under worst-case conditions in the engine compartment (hot
surface temperature of 700 [deg]C, closed hood on engine compartment)
found HF concentrations as high as 36 ppm in the engine compartment and
2 to 8 ppm in the passenger compartment. The amount of HF generated
from a typical charge of HFC-134a, if it all burned or decomposed,
could be even more than for the expected charge of HFO-1234yf because
charge sizes using HFO-1234yf are expected to be smaller (EPA-HQ-OAR-
2008-0664-0056.2). The SAE CRP considered potential risks of HF
exposure from both HFO-1234yf and from HFC-134a. Both presented
potential risks on the order of 10-12 occurrences per
operating hour (EPA-HQ-OAR-2008-0664-0056.2, -0096.1). This corresponds
to less than one case per year across the entire fleet of motor
vehicles in the U.S. Although there is no specific testing data on HF
production from HFC-152a, another acceptable refrigerant for MVAC,
since this compound contains fluorine, it presents risks of HF
generation as well. As discussed above in Section IV of the preamble,
we are not requiring specific use conditions that regulate production
of HF, either directly or indirectly, because of the low level of risk.
However, the final use conditions in this rule address the risks of HF
production, as well as risks of flammability, by requiring certain
design safety features of MVAC systems using HFO-1234yf and by
requiring risk analysis for each car model through FMEAs.
Comment: A commenter provided results from a test by IBExU on the
decomposition of HFO-1234yf under heat (EPA-HQ-OAR-2008-0664-0053.3).
This commenter strongly warned against a decision in favor of HFO-
1234yf because it would form highly toxic HF when burning. Three
commenters disagreed that the results of the IBExU testing were
relevant because test conditions did not represent realistic
conditions. One commenter said that the SAE risk assessment, which used
actual vehicle test data for HF formation, found that actual HF
formation rates are far below the levels [from the IBExU test results]
cited by the first commenter, the Federal Environmental Agency
(Umweltbundesamt--UBA).
Response: The IBExU testing of HF generation from HFO-1234yf is not
relevant to assessing the risks of HFO-1234yf as a refrigerant in MVAC.
Laboratory tests concerning the nature of HF generation on hot surfaces
found that this depends on the contact time of reactants on the hot
surface, the temperature of the hot surface and the movement of
refrigerant in diluted concentrations due to airflow (EPA-HQ-OAR-2008-
0664-0056.2; EPA-HQ-OAR-2008-0664-0116.2). The IBExU testing involved
heating the refrigerant steadily in a sealed flask. Thus, the contact
time in that test was far greater than would occur in an engine
compartment and the movement of refrigerant in that test was
essentially zero, unlike in an engine compartment where there would be
constant air movement.
Comment: Another test from BAM reported by UBA examined HF
formation from HFO-1234yf and from HFC-134a (EPA-HQ-OAR-2008-0664-
0080.1). Fifty grams of refrigerant was streamed through a hole of 2 mm
diameter onto a hot metal surface. The study found that pure HFO-1234yf
exploded on the hot surface whereas pure HFC-134a did not. The study
also found that when HFO-1234yf was mixed with 3% oil, it exploded at
600 [deg]C. The commenter stated that handling of HFO-1234yf in the
presence of hot metal surfaces results in HF formation in
concentrations far above allowed workplace concentrations.
Response: These results are not consistent with results from hot-
plate tests conducted by an automobile manufacturer and by a chemical
manufacturer for the SAE CRP (EPA-HQ-OAR-2008-0664-0056.2; EPA-HQ-OAR-
2008-0664-0115.1). Those manufacturers found that neither HFO-1234yf
nor HFC-134a alone ignited at 900 [deg]C. One of these tests found that
HFO-1234yf mixed with PAG oil combusted starting at 730 [deg]C, while
HFC-134a mixed with PAG oil ignited at 800 [deg]C and above; the other
test observed no ignition of a blend of each refrigerant with PAG oil
at 800 [deg]C, but both blends ignited at 900 [deg]C. Based on the lack
of reproducibility of the specific ignition temperature, it appears
that the specific ignition temperature may depend on variables in the
testing (e.g., flash point of the oil used, amount of mixture used,
angle of application, and air flow available). This information also
shows that mixtures of refrigerant with compressor oil can combust at
lower temperatures than pure refrigerant and that mixtures of HFO-
1234yf and oil and mixtures of HFC-134a and oil present similar risks
of ignition and HF generation. Thus, we concluded that the risks of
toxicity from HF exposure due to combustion or decomposition of HFO-
1234yf are comparable to those from HFC-134a.
Further, the risks from toxicity of HF posed by both refrigerants
are small. The SAE CRP estimates this risk on the order of
10-12 cases per operating hour (EPA-HQ-OAR-2008-0664-
0086.1). This is equivalent to less than one event per year across the
entire fleet of motor vehicles in the U.S. For comparison, this is less
than one ten-thousandth the risk of a highway vehicle fire and one
fortieth or less of the risk of a fatality from deployment of an airbag
during a vehicle collision (EPA-HQ-OAR-2008-0664-0056.2).
E. Retrofit Usage
Comment: Several commenters stated that HFO-1234yf should be
allowed initially in new vehicles but should not be used to retrofit
vehicles using HFC-134a, or at least not unless there are industry
standards to guide such a process. Other commenters stated that it is
critical to allow a natural phase-out of the fleet of cars using HFC-
134a as the refrigerant, rather than requiring retrofitting existing
cars with HFO-1234yf. A commenter expressed concern that retrofitting
of HFC-134a MVAC systems with HFO-1234yf would result in cases of
cross-contamination of refrigerant, while another commenter contested
this statement and found it unsupported. Other commenters opposed
obstacles that would prevent older MVACs from being retrofitted to the
new refrigerant. These commenters mentioned the potential for
greenhouse gas benefits when retrofitting systems currently using HFC-
134a with HFO-1234yf.
Response: The submitter did not request review of HFO-1234yf for
retrofitting vehicles and thus EPA did not review HFO-1234yf as
acceptable (or acceptable subject to use conditions) for retrofitting
in MVAC in this rulemaking. Consistent with the request submitted to
the Agency, we proposed to find HFO-1234yf acceptable for use subject
to use conditions in new MVAC systems and evaluated its risks only for
use in new systems. We will consider the retrofit use of HFO-1234yf in
MVAC systems if we receive a submission that specifically addresses
retrofitting and the risks that are unique to retrofitting. In response
to the commenter who raised a concern about a ``phase-out'' of HFC-134a
and the potential that we would ``require'' use of HFO-1234yf, we
[[Page 17510]]
note that our rulemakings under SNAP do not require use of any specific
substitute. Rather, under SNAP, we have established lists of
substitutes that are acceptable for use in various end-uses (such as
for MVACs) and end-users are free to choose which substitute to use,
but must do so consistent with any use conditions that apply. As stated
in the rule establishing the SNAP program, ``The Agency * * * does not
want to intercede in the market's choice of available substitutes,
unless a substitute has been proposed or is being used that is clearly
more harmful to human health and the environment than other
alternatives.'' 59 FR 13046, March 18, 1994. We further note that this
rulemaking does not change the status of HFC-134a, which remains an
acceptable substitute for use in MVACs, subject to use conditions.
F. Use by ``Do-it-Yourselfers''
Comment: Some commenters raised concerns about EPA's statements in
the proposed rule about potential health effects that might occur
without professional training and the use of CAA Section 609 certified
equipment. These commenters stated that the studies and testing in the
docket support a finding that use of HFO-1234yf by non-professionals is
safe and do not offer valid technical support for EPA's concerns.
Response: EPA's risk assessment and risk screen both indicated that
worst-case exposure levels expected during servicing by do-it-
yourselfers are of potential concern (EPA-HQ-OAR-2008-0664-0036 and
EPA-HQ-OAR-2008-0664-0038). In both documents, this was based upon
estimated exposure levels from a 2008 risk assessment by Gradient
Corporation for the SAE CRP (EPA-HQ-OAR-2008-0664-0008). In EPA's risk
assessment (EPA-HQ-OAR-2008-0664-0036), we found that the level that
EPA determined did not cause health effects in laboratory animals might
be only 2 to 3 times higher than the exposure predicted for that use
(the ``margin of exposure''). Our risk assessment indicated a higher,
more protective margin of exposure of at least 30 was needed to account
for uncertainty in the extrapolation from animals to humans and for
variability in the human population. In other words, we found that
based on worst-case assumptions, a do-it-yourselfer's exposure could be
10 or more times the level that EPA considered safe. The margin of
exposure was calculated using a conservative estimated exposure level
of 45,000 ppm over 30 minutes and a human equivalent concentration of
98,211 ppm from a no-observed adverse effect level that we selected as
the point of departure for risk assessment (EPA-HQ-OAR-2008-0664-0036).
However, under this final rule, unique fittings have only been
submitted for servicing fittings for the high-side and low-side ports
and for large containers of HFO-1234yf and thus the acceptability
listing is limited to use of HFO-1234yf with the unique fittings
specified (e.g., for large containers of 20 pounds or more). We expect
these containers would not be purchased by DIYers because of their
expense ($800 or more per container) and because they would contain
enough refrigerant for 10 charges or more. We will continue to review
the issue of safe use for DIYers if and when we are requested to review
unique fittings for a smaller container size. In addition, EPA is
further addressing the issue of risks to DIYers in the Significant New
Use Rule for 1-propene-2,3,3,3-tetrafluoro- (75 FR 65987, October 27,
2010). This SNUR requires submission of a SNUN at least 90 days before
sale or distribution of products intended for use by a consumer for the
purpose of servicing, maintenance and disposal involving HFO-1234yf.
EPA's proposed rule on the use of HFO-1234yf as a substitute for
CFC-12 in new MVAC systems did not propose to establish use conditions
for servicing vehicles by certified professionals, but our analyses
indicate that there is not significant risk to certified professionals,
because HFC-134a, which is currently used in most MVAC systems,
presents similar risks and professionals have the knowledge and
equipment to mitigate any risks. We plan to further address servicing
by professionals when we develop a new rule under section 609 of the
Clean Air Act for servicing and maintenance of MVAC systems.
Comment: Some commenters supported prohibiting sale of HFO-1234yf
in small containers. Other commenters stated that only certified
technicians should be allowed to purchase and use refrigerants,
including HFC-134a and HFO-1234yf. Other commenters found no data to
support restrictions on the sale of HFO-1234yf to non-professionals.
Response: As noted previously, the submission only addressed unique
fittings for large containers (e.g., 20 lbs or larger) of HFO-1234yf.
If anyone is interested in using HFO-1234yf in small cans or other
small containers, they would need to contact the refrigerant
manufacturer to submit unique fittings for approval under the SNAP
program. Thus, under this final rule, we believe that only certified
technicians will purchase HFO-1234yf because the larger containers are
likely to be prohibitively expensive for individuals performing DIY
servicing ($800 or more for a 20 lb cylinder) and are likely to be too
large for most individuals to use, containing enough refrigerant for 10
or more charges.
We also note that in a separate final rule under the authority of
TSCA (October 27, 2010; 75 FR 65987), EPA requires among other things,
that notice must be given to EPA 90 days before (1) HFO-1234yf is used
commercially other than in new passenger cars and vehicles in which the
charging of motor vehicle air conditioning systems with HFO-1234yf was
done by the motor vehicle OEM or (2) sale or distribution of products
intended for use by a consumer for the purpose of servicing,
maintenance and disposal involving HFO-1234yf.
Comment: A commenter stated that banning DIY use of HFO-1234yf will
mean that car owners will be forced to have professionals perform
service work on their AC systems at a significantly higher cost. This
commenter stated that millions of lower-income motorists may be forced
to go without air conditioning each year or may seek out lower-cost
alternatives such as propane or HFC-152a.
Response: While this final rule effectively prohibits DIY use
because the final use conditions do not include unique fittings
allowing for use with small refrigerant containers, we are not making
any final determination about whether HFO-1234yf may be safely used by
DIYers. As we noted above, we have not yet received a submission for
DIY use or received unique fittings for small containers from the
manufacturer, but would evaluate such submissions when we receive one.
We note that because it is unlikely that any cars will have MVAC
systems with HFO-1234yf before the 2013 model year, we believe the
availability of small containers for DIY use will not be of concern
until such cars are sold and there is a need to recharge a new MVAC
system on a model year 2013 vehicle. The separate final Significant New
Use Rule that the Agency has issued under TSCA (75 FR 65987; October
27, 2010) requires submission of a Significant New Use Notice at least
90 days before sale or distribution of products intended for DIY use.
With respect to the commenter who suggests that some people may
seek lower cost alternatives, presumably to repair an existing MVAC, we
note that under current EPA regulations in appendix D to subpart G of
40 CFR part 82, it is not legal to top-off the
[[Page 17511]]
refrigerant in an MVAC system with a different substitute refrigerant.
G. Servicing Issues
Comment: Several commenters stated that appropriate training and
certification should be required to purchase HFO-1234yf for use in
MVACs. Four commenters also stated that the final regulation should
include a provision requiring proof of certification in order to
purchase HFO-1234yf, and recommended that current AC systems tests
(i.e., for CAA section 609 certification) be updated.
Some commenters disagreed with EPA's statement that HFO-1234yf may
cause serious health effects when used in servicing and maintaining
MVACs without professional training. Another commenter stated that EPA
is limiting productivity by only allowing dealerships to perform
refrigerant maintenance, and that independent MVAC service shops should
be allowed to be certified. The commenter also questioned who will
monitor ``certified'' technicians employed by dealerships that may do
work on the side. A commenter representing automobile dealerships
specifically opposed mandatory requirements for certification of
technicians because of potential costs and burden on small businesses.
Response: As background for the public comments, we note that under
EPA's regulations implementing section 609, one must be a section 609
certified technician in order to purchase CFC-12 or other ODS for use
in MVAC (40 CFR 82.34(b)). Section 609(e) of the CAA itself
specifically prohibits sale of small containers less than 20 pounds
with Class I or Class II substances suitable for use as a refrigerant
in MVAC, except for individuals performing service for consideration in
compliance with section 609. However, there is no comparable
restriction on the sale of HFC-134a or on other substitutes for MVAC
that do not contain Class I or Class II ODS, such as HFO-1234yf.
In the NPRM (74 FR 53449), EPA stated that any specific training
and certification requirements would be adopted through a rulemaking
under the authority of CAA section 609 and would be codified in subpart
B of 40 CFR part 82, which contains the regulations implementing
section 609. We will address concerns regarding certification and
training requirements during that separate rulemaking process. We note,
however, that the CAA itself mandates that persons performing service
for consideration that involve the refrigerant must be properly trained
and certified. Furthermore, as noted previously, we believe that there
is not a significant health risk to professionals from HFO-1234yf
because they will have the knowledge and equipment to mitigate any
risks. Also, because HFC-134a presents similar risks to HFO-1234yf, and
the flammability risks of HFO-1234yf are less than those for HFC-152a,
the health risks of HFO-1234yf are not significantly greater than those
of other available substitutes.
With regard to whether independent service shops could service
MVACs with HFO-1234yf or whether service would be limited to
``dealerships,'' we note that neither this rule nor any other CAA
regulation would limit servicing to dealerships. The comment may
concern the withdrawn SNUR, 75 FR 4983 (February 1, 2010), which
referred to the ``original equipment manufacturer''; the commenter may
have interpreted this term to mean an automobile dealership. The final
SNUR (October 27, 2010; 75 FR 65987) requires a significant new use
notice to EPA at least 90 days before ``commercial use other than in
new passenger cars and vehicles in which the charging of motor vehicle
air conditioning systems with the PMN substance [HFO-1234yf] was done
by the motor vehicle original equipment manufacturer.'' This
requirement restricts commercial use of HFO-1234yf to use for vehicles
that were initially charged with HFO-1234yf by the automobile's
manufacturer, as opposed to allowing commercial use of HFO-1234yf for
vehicles initially charged with a different refrigerant. The term
``original equipment manufacturer'' refers to the automobile
manufacturer, not to dealerships.
Comment: Commenters indicated that SAE International is developing
standards for safety and servicing of alternative refrigerant HFO-
1234yf MVAC systems. Another commenter stated that there are
appropriate mechanisms within the industry for training. One commenter
representing automobile dealerships objected to mandatory Section 609
technician certification and training for use of HFO-1234yf, stating
that because dealerships already train technicians on flammable
substances in accordance with hazard communication standards of the
Occupational Safety and Health Administration (OSHA), and since the
risks associated with HFO-1234yf are similar to those that already
exist in MVAC service facilities, mandatory training and proof of
training is not necessary. To enable training pursuant to the OSHA
hazard communication standard, the commenter stated that MVAC system
and refrigerant suppliers should provide dealerships with sufficient
information on the hazards posed by HFO-1234yf.
Response: EPA is issuing use conditions in this final rule that
reference relevant SAE technical standards on safety. This rule does
not, however, include a use condition requiring technician training and
does not refer to specific training standards. We agree with the
commenter that current technician training generally should be
sufficient to ensure that professional technicians will use HFO-1234yf
safely. Although this SNAP determination does not contain a use
condition regarding technician training, as noted above, section 609 of
the CAA requires technician training for persons servicing for
consideration. EPA will consider in a separate rulemaking under section
609, whether it is necessary to modify our existing regulations under
section 609 to include additional specifications for HFO-1234yf.
Comment: A commenter representing automobile dealerships opposed
mandatory requirements for recycling and containment of the refrigerant
because of potential costs and minimal environmental benefits.
Response: This rulemaking does not impose requirements for
recycling or containment of the refrigerant. A separate rulemaking
under CAA section 609 will address practices required in the servicing
of MVAC systems using HFO-1234yf, including recycling and recovery.
Further, EPA notes that Section 608 of the CAA prohibits the
intentional release of any refrigerant during the maintenance, repair,
service, or disposal of refrigeration and air conditioning equipment,
unless the Administrator determines through rulemaking that such
release does not pose a threat to the environment. We have not made
such a determination for HFO-1234yf.
H. Cost, Availability, and Small Business Impacts
Comment: One late commenter stated that there was insufficient
information in the record on the cost, terms of availability and
anticipated market share of HFO-1234yf for EPA to make the required
statutory findings that HFO-1234yf ``reduces the overall risk to human
health and the environment'' by comparison to other alternatives that
are already available. The commenter stated that this information is
necessary in order for EPA to assess anticipated environmental effects
adequately. The same commenter stated that EPA's environmental analysis
is based on price assumptions that were not disclosed and are no longer
valid, and thus, EPA should subpoena the
[[Page 17512]]
information from the manufacturer and reopen the public comment period.
Response: EPA believes that there was sufficient information in the
record at the time of proposal for us to complete a meaningful
environmental analysis, even in the absence of definitive cost
information. At the time of proposal, we had available both estimates
from a trade magazine provided by the manufacturer (Weissler, 2008), as
well as estimates of price provided in the initial submission from the
manufacturer (EPA-HQ-OAR-2008-0664-0013). The estimates of price
provided by the manufacturer were claimed as confidential business
information and thus were not available in the record to the public.
We typically use this type of information for purposes of
determining market penetration for a particular substance, so that we
can evaluate how much of the substitute will likely be used and thus
the environmental risks it might pose. In this case, however, because
the automobile industry tends to prefer use of a single substitute,
information on the cost of the substitute was not critical to our
analysis. Thus, in conducting our environmental analysis, we took a
conservative approach, assuming that all new MVAC systems began using
HFO-1234yf by 2020 (i.e., full market penetration). We also considered
an even more conservative scenario, in which HFO-1234yf would be the
only refrigerant used for stationary air conditioning and for
refrigeration as of 2020, as well as for MVAC. Even with these highly
conservative assumptions, we found that there would not be sufficient
negative environmental impacts due to emissions of HFO-1234yf to
warrant finding it unacceptable.
In the proposal, we mentioned a cost estimate for HFO-1234yf of
$40-$60/lb (Weissler, 2008). More recently, the first automobile
manufacturer announcing its intention to use HFO-1234yf confirmed that
this range does not underestimate prices of HFO-1234yf and is
consistent with the manufacturer's long-term purchase contracts
(Sciance, 2010). Thus, the most recent information shows costs to be
similar to those we considered at the time of proposal. This data
contradicts the late commenter's assertion that the manufacturer's
effective monopoly would result in significantly different, higher
costs that would invalidate EPA's earlier analysis. In any event,
assuming that costs were higher as suggested by the commenter, then we
expect that use of HFO-1234yf would be less than assumed for our health
and environmental risk analysis. As mentioned in the proposal,
emissions, and thus the resulting environmental effects such as impacts
on local air quality or on production of TFA, would be expected to be
less under a scenario with higher prices and less use of HFO-1234yf.
Our analysis assumes widespread use and thus its results would be
protective.
We note that where a new chemical is introduced, there is some
uncertainty in the price. At best, the manufacturer can provide rough
estimates of price and of market share before the chemical is produced
in commercial quantities and becomes subject to supply and demand
pressures. EPA's requirement for information on cost, anticipated
availability in the market, and anticipated market share (40 CFR
82.178(a)(14) through (16)) should not be construed as requiring
precise, detailed cost estimates based upon a well-defined methodology.
As noted above, we use these numbers for the purposes of predicting
market penetration and thus how much of a particular substitute might
be used and thus pose an environmental risk. As we did for HFO-1234yf,
we typically take an environmentally-protective approach to our
evaluation, assuming use at least as high as that the cost and
availability information may indicate.
Comment: A late commenter stated that the information in the record
is insufficient for EPA to make a statutory finding that HFO-1234yf is
``currently or potentially available.'' The commenter stated that a
previous decision by the United States Court of Appeals for the
District of Columbia Circuit (Honeywell International, Inc. v. EPA, 374
F.3d 1363 (D.C. Cir. 2004)) implied that an interpretation of the term
``available'' in CAA section 612(c)(2) could potentially consider
economic factors if EPA adopted such an approach as a reasonable
interpretation of the statutory language. The commenter states that EPA
should obtain information as to the anticipated cost of HFO-1234yf if
the manufacturer does not grant licenses to produce.
Response: The CAA does not require that EPA find a substitute to be
available or potentially available when finding it acceptable. Section
612(c) states: ``* * * It shall be unlawful to replace any class I or
class II substance with any substitute substance which the
Administrator determines may present adverse effects to human health or
the environment, where the Administrator has identified an alternative
to such replacement that--reduces the overall risk to human health and
the environment; and is currently or potentially available. * * *''
This section makes clear that it is not the substitute under review
that must be available or potentially available, but rather alternative
replacements for ODS that EPA determines pose less overall risk to
human health and the environment than the substitute being reviewed.
Thus, if there are alternatives to the substance under review that are
currently or potentially available and that pose less risk, EPA cannot
find the substitute under review acceptable. Section 612(c) establishes
no requirement that EPA must determine that the substitute under review
is ``available.'' See also 40 CFR 82.180(b) (describing types of
listing decisions EPA can make in reviewing substitutes \26\). We note
that even if EPA was required to determine that the substitute under
review is available or potentially available before it could make an
acceptability determination, we believe that the available information
supports that HFO-1234yf is potentially available. EPA's definition of
``potentially available'' at 40 CFR 82.172 provides that ``potentially
available'' is defined as any alternative for which adequate health,
safety, and environmental data, as required for the SNAP notification
process, exist to make a determination of acceptability, and which the
Agency reasonably believes to be technically feasible, even if not all
testing has yet been completed and the alternative is not yet produced
or sold. This definition makes explicit that it is not necessary to
have perfect information on a substitute nor is it necessary for the
substitute to be produced or sold in order for EPA to consider it
``potentially available.'' Instead, it is necessary for EPA to find the
health, safety and environmental data adequate to make a determination
of acceptability, and for the Agency to reasonably believe that the
alternative is ``technically feasible,'' in order for the alternative
to be potentially available. We believe the record contains adequate
information showing that HFO-1234yf
[[Page 17513]]
is potentially available. The manufacturer has submitted the
information required under 40 CFR 82.178 (e.g., pre-manufacture notice
form and TSCA/SNAP addendum form containing: Name and description of
the substitute, physical and chemical information, information on ODP
and global warming impacts, toxicity data, data on environmental fate
and transport, flammability, exposure, cost and estimated production).
The submitter has also provided unique fittings as required under
appendix D to subpart G of 40 CFR part 82. Thus, we believe that there
is ``adequate health, safety, and environmental data.'' Even if the
commenter were correct about claims that higher costs would result if
the manufacturer does not grant licenses for production, as discussed
above, this does not affect the adequacy of the health, safety, and
environmental data for HFO-1234yf, because we have protectively assumed
widespread use that would result in more emissions and greater
environmental impacts. In addition, based on the experimental work
conducted by the automobile industry, we reasonably believe that HFO-
1234yf is technically feasible as a refrigerant. Thus, HFO-1234yf would
still be ``potentially available'' under the SNAP program's definition.
---------------------------------------------------------------------------
\26\ The regulations for the SNAP program include cost and
availability as one of the criteria for review as to whether a
substitute is acceptable or unacceptable as a replacement for ozone
depleting substances (82.180(a)(7)(vii)), along with a number of
criteria for different aspects of health and environmental impacts.
Cost and availability are included as criteria because they affect
assumptions we may make about a substitute regarding its risks,
i.e., we need to know its cost and availability so we can make
assumptions about the risk it might pose. In this case, we assumed
that HFO-1234yf would be used widely across the industry in new
MVACs because widespread use of a single refrigerant in new car
models has been the industry practice with MVAC systems. Thus, more
detail on cost and availability of the substitute was not necessary
in order to identify assumptions we should make for estimating risk.
---------------------------------------------------------------------------
One commenter points to Honeywell International, Inc. v. EPA, 374
F.3d 1363 in urging EPA to explicitly include cost as a consideration
in determining whether a substitute is ``potentially available.'' In
that case, the court vacated and remanded a SNAP decision in which EPA
listed a foam blowing substitute as acceptable subject to ``narrowed
use limits'' on the basis that for some niche foam blowing uses, the
substitutes that were already listed as acceptable might not be
available. Under the narrowed use limits, the end-user would need to
demonstrate and document that other substitutes were not technically
feasible for a particular use. The court vacated and remanded EPA's
rule on the basis that EPA had considered cost in concluding that
already listed substitutes might not be available based on
``technical'' feasibility, and that EPA had not attempted to justify
the rule on the ground that the statute allows it to consider economic
factors in making its SNAP determinations. The court left open the
question of whether EPA could attempt to interpret the term
``available'' in section 612(c) as allowing for consideration of costs.
Again, we note that ``available or potentially available'' applies
only to the substitutes against which the substitute at issue is being
compared. The Agency has not decided whether consideration of the cost
of other substitutes should be a factor to consider in determining
whether they are available or potentially available and thus should (or
should not) be used for comparison to a substitute under review.
However, we note that for purposes of the substitute under review, the
Agency firmly believes that cost should not be the primary or sole
basis for finding a substitute unacceptable. EPA's role is to determine
the health and environmental risk associated with the use of
substitutes and the market should serve to address the issue of costs.
Costs will necessarily be a factor considered by the automobile
manufacturers in deciding which substitute to use.
Comment: Two commenters stated that EPA needed to perform further
analysis on the potential small business impacts and costs of EPA's
regulations and the introduction of HFO-1234yf. A commenter
representing recyclers of automobiles and scrap metal expressed concern
about the regulatory burden and costs that automotive recyclers are
likely to incur if they must manage flammable refrigerants that are
regulated as hazardous waste under EPA's regulations implementing the
Resource Conservation and Recovery Act (RCRA). The same commenter also
suggests that the RCRA subtitle C regulations would need to be changed
to alleviate the hazardous-waste management requirements for handling
HFO-1234yf. The other commenter mentioned the costs to service and
repair shops, end-of-life vehicle recyclers, and automobile
dealerships, and stated that EPA needed to analyze costs to these small
businesses under the Regulatory Flexibility Act (RFA). This latter
commenter stated that EPA should determine if a significant change in
price and supply expectations would affect the way that these
businesses handle and deal with automobile repairs and recycling.
Response: The RFA applies only when there are small entities
subject to the requirements of the proposed or final rule. 5 U.S.C.
Sec. 604(a)(3). We believe the potential burden of complying with RCRA
regulations placed on those recycling or recovering a substitute is
generally not pertinent to a decision of whether HFO-1234yf should be
found acceptable under SNAP. To the extent the commenters are
suggesting that we must evaluate such costs for purposes of the
Regulatory Flexibility Act, we note that under the RFA we evaluate
costs imposed by the enforceable regulations being promulgated. To the
extent the costs referred to by the commenter are already imposed under
RCRA, they would not be new costs, but costs associated with the
relevant RCRA regulations. Moreover, under this SNAP final rule, EPA is
not requiring the use of HFO-1234yf, and thus the costs associated with
its use are not due to enforceable regulatory requirements under SNAP.
To the extent there are enforceable requirements for those persons who
choose to use this new substitute, those requirements (the ``use
conditions'') apply primarily to manufacturers of automobiles and MVAC
systems, because they concern design of MVAC systems. The one use
condition of the rule that applies to servicing of MVAC systems, and
thus, could apply to small businesses, is the requirement for specific
unique service fittings. However, EPA's existing SNAP regulations at
appendix D to subpart G of 40 CFR part 82 already require unique
service fittings as specified by the refrigerant manufacturer. Thus,
the costs of purchasing new unique fittings for this refrigerant are
imposed by the pre-existing regulation. This rule specifies the
requirements for the type of unique fitting, in accordance with the
fittings provided to EPA by the manufacturer. These fittings are part
of the SAE J639 standard. It is not clear that there would be any cost
differential between these specific unique fittings and others that the
automotive industry could adopt instead. For these reasons, EPA is able
to certify that this regulation will not create a significant impact on
a significant number of small entities.
Regulations concerning disposal of refrigerant from MVAC systems
and other refrigerant-containing appliances under section 608 of the
CAA are at subpart F of 40 CFR part 82. Cost and benefit estimates for
these regulations are at http://www.regulations.gov, docket EPA-HQ-OAR-
2003-0167. EPA notes that there may be costs of servicing or of
disposal (end-of-life) to small businesses under future regulations
under section 609 or 608 of the CAA. We will conduct an analysis of
such costs, and any potential significant impacts on small entities, as
necessary, as part of those future rulemakings.
Comment: A commenter stated that to comply with requirements of the
Unfunded Mandates Reform Act (UMRA), EPA needed to perform further
analysis on the potential costs of EPA's SNAP regulations for HFO-
1234yf to determine if the rule would result in the expenditure of $100
million or more per year by the private sector. In particular, the
commenter stated that EPA must obtain more information on pricing and
[[Page 17514]]
the effect of the manufacturer's patent to analyze this.
Response: UMRA applies only to ``enforceable duties'' imposed on
State, local, and Tribal governments or on the private sector. The SNAP
rule does not impose duties on governments. As we have noted
previously, the SNAP program does not mandate the use of any specific
substitute for ozone depleting substances. Rather, through this action,
we are expanding the choices of MVAC refrigerants available to the
private sector. The issue raised by the commenter concerning the cost
of the refrigerant and the effect of the manufacturer's patent on
pricing is not related to any requirement of the rule, and thus, EPA is
not required to consider that cost under UMRA.
VIII. How does the SNAP program work?
A. What are the statutory requirements and authority for the SNAP
program?
Section 612 of the Clean Air Act (CAA) requires EPA to develop a
program for evaluating alternatives to ozone-depleting substances
(ODS). EPA refers to this program as the Significant New Alternatives
Policy (SNAP) program. The major provisions of section 612 are:
1. Rulemaking
Section 612(c) requires EPA to promulgate rules making it unlawful
to replace any class I (i.e., chlorofluorocarbon, halon, carbon
tetrachloride, methyl chloroform, methyl bromide, and
hydrobromofluorocarbon) or class II (i.e., hydrochlorofluorocarbon)
substance with any substitute that the Administrator determines may
present adverse effects to human health or the environment where the
Administrator has identified an alternative that (1) reduces the
overall risk to human health and the environment, and (2) is currently
or potentially available.
2. Listing of Unacceptable/Acceptable Substitutes
Section 612(c) requires EPA to publish a list of the substitutes
unacceptable for specific uses and to publish a corresponding list of
acceptable alternatives for specific uses. The list of acceptable
substitutes is found at http://www.epa.gov/ozone/snap/lists/index.html
and the lists of ``unacceptable'', ``acceptable subject to use
conditions'', and ``acceptable subject to narrowed use limits''
substitutes are found at subpart G of 40 CFR part 82.
3. Petition Process
Section 612(d) grants the right to any person to petition EPA to
add a substance to, or delete a substance from, the lists published in
accordance with section 612(c). The Agency has 90 days to grant or deny
a petition. Where the Agency grants the petition, EPA must publish the
revised lists within an additional six months.
4. 90-Day Notification
Section 612(e) directs EPA to require any person who produces a
chemical substitute for a class I substance to notify the Agency not
less than 90 days before new or existing chemicals are introduced into
interstate commerce for significant new uses as substitutes for a class
I substance. The producer must also provide the Agency with the
producer's unpublished health and safety studies on such substitutes.
5. Outreach
Section 612(b)(1) states that the Administrator shall seek to
maximize the use of Federal research facilities and resources to assist
users of class I and II substances in identifying and developing
alternatives to the use of such substances in key commercial
applications.
6. Clearinghouse
Section 612(b)(4) requires the Agency to set up a public
clearinghouse of alternative chemicals, product substitutes, and
alternative manufacturing processes that are available for products and
manufacturing processes which use class I and II substances.
B. What are EPA's regulations implementing section 612?
On March 18, 1994, EPA published the original rulemaking (59 FR
13044) which established the process for administering the SNAP program
and issued EPA's first lists identifying acceptable and unacceptable
substitutes in the major industrial use sectors (subpart G of 40 CFR
part 82). These sectors include: Refrigeration and air conditioning;
foam blowing; cleaning solvents; fire suppression and explosion
protection; sterilants; aerosols; adhesives, coatings and inks; and
tobacco expansion. These sectors compose the principal industrial
sectors that historically consumed the largest volumes of ODS.
Section 612 of the CAA requires EPA to list as acceptable only
those substitutes that do not present a significantly greater risk to
human health and the environment as compared with other substitutes
that are currently or potentially available.
C. How do the regulations for the SNAP program work?
Under the SNAP regulations, anyone who plans to market or produce a
substitute to replace a class I or II ODS in one of the eight major
industrial use sectors must provide notice to the Agency, including
health and safety information on the substitute at least 90 days before
introducing it into interstate commerce for significant new use as an
alternative. This requirement applies to the person planning to
introduce the substitute into interstate commerce,\27\ typically
chemical manufacturers, but may also include importers, formulators,
equipment manufacturers, or end-users \28\ when they are responsible
for introducing a substitute into commerce.
---------------------------------------------------------------------------
\27\ As defined at 40 CFR 82.104 ``interstate commerce'' means
the distribution or transportation of any product between one state,
territory, possession or the District of Columbia, and another
state, territory, possession or the District of Columbia, or the
sale, use or manufacture of any product in more than one state,
territory, possession or District of Columbia. The entry points for
which a product is introduced into interstate commerce are the
release of a product from the facility in which the product was
manufactured, the entry into a warehouse from which the domestic
manufacturer releases the product for sale or distribution, and at
the site of United States Customs clearance.
\28\ As defined at 40 CFR 82.172 ``end-use'' means processes or
classes of specific applications within major industrial sectors
where a substitute is used to replace an ozone-depleting substance.
---------------------------------------------------------------------------
The Agency has identified four possible decision categories for
substitutes: acceptable; acceptable subject to use conditions;
acceptable subject to narrowed use limits; and unacceptable. Use
conditions and narrowed use limits are both considered ``use
restrictions'' and are explained below. Substitutes that are deemed
acceptable with no use restrictions (no use conditions or narrowed use
limits) can be used for all applications within the relevant end-uses
within the sector. Substitutes that are acceptable subject to use
restrictions may be used only in accordance with those restrictions. It
is illegal to replace an ODS with a substitute listed as unacceptable,
unless certain exceptions (e.g., test marketing, research and
development) provided by the regulation are met.
After reviewing a substitute, the Agency may determine that a
substitute is acceptable only if certain conditions in the way that the
substitute is used are met to minimize risks to human health and the
environment. EPA describes such substitutes as ``acceptable subject to
use conditions.'' Entities that use these substitutes without meeting
the
[[Page 17515]]
associated use conditions are in violation of section 612 of the Clean
Air Act and EPA's SNAP regulations.
For some substitutes, the Agency may permit a narrowed range of use
within an end-use or sector. For example, the Agency may limit the use
of a substitute to certain end-uses or specific applications within an
industry sector. The Agency requires a user of a narrowed use
substitute to demonstrate that no other acceptable substitutes are
available for their specific application by conducting comprehensive
studies. EPA describes these substitutes as ``acceptable subject to
narrowed use limits.'' A person using a substitute that is acceptable
subject to narrowed use limits in applications and end-uses that are
not consistent with the narrowed use limit is using the substitute in
an unacceptable manner and is in violation of section 612 of the CAA
and EPA's SNAP regulations.
The Agency publishes its SNAP program decisions in the Federal
Register (FR). EPA publishes decisions concerning substitutes that are
deemed acceptable subject to use restrictions (use conditions and/or
narrowed use limits), or for substitutes deemed unacceptable, as
proposed rulemakings to allow the public opportunity to comment, before
publishing final decisions.
In contrast, EPA publishes decisions concerning substitutes that
are deemed acceptable with no restrictions in ``notices of
acceptability,'' rather than as proposed and final rules. As described
in the rule initially implementing the SNAP program (59 FR 13044), EPA
does not believe that rulemaking procedures are necessary to list
alternatives that are acceptable without restrictions because such
listings neither impose any sanction nor prevent anyone from using a
substitute.
Many SNAP listings include ``comments'' or ``further information''
to provide additional information on substitutes. Since this additional
information is not part of the regulatory decision, these statements
are not binding for use of the substitute under the SNAP program.
However, regulatory requirements so listed are binding under other
regulatory programs. The ``further information'' classification does
not necessarily include all other legal obligations pertaining to the
use of the substitute. While the items listed are not legally binding
under the SNAP program, EPA encourages users of substitutes to apply
all statements in the ``further information'' column in their use of
these substitutes. In many instances, the information simply refers to
sound operating practices that have already been identified in existing
industry and/or building-codes or standards. Thus, many of the
statements, if adopted, would not require the affected user to make
significant changes in existing operating practices.
D. Where can I get additional information about the SNAP program?
For copies of the comprehensive SNAP lists of substitutes or
additional information on SNAP, refer to EPA's Ozone Depletion Web site
at http://www.epa.gov/ozone/snap/index.html. For more information on
the Agency's process for administering the SNAP program or criteria for
evaluation of substitutes, refer to the SNAP final rulemaking published
March 18, 1994 (59 FR 13044), codified at subpart G of 40 CFR part 82.
A complete chronology of SNAP decisions and the appropriate citations
are found at http://www.epa.gov/ozone/snap/chron.html.
IX. Statutory and Executive Order Reviews
A. Executive Order 12866: Regulatory Planning and Review
Under Executive Order (EO) 12866 (58 FR 51735, October 4, 1993),
this action is a ``significant regulatory action.'' It raises novel
legal or policy issues arising out of legal mandates, the President's
priorities, or the principles set forth in the Executive Order.
Accordingly, EPA submitted this action to the Office of Management
and Budget (OMB) for review under EO 12866 and any changes made in
response to OMB recommendations have been documented in the docket for
this action.
B. Paperwork Reduction Act
This action does not impose any new information collection burden.
Today's action is an Agency determination. It contains no new
requirements for reporting. The only new recordkeeping requirement
involves customary business practice. Today's rule requires minimal
record-keeping of studies done to ensure that MVAC systems using HFO-
1234yf meet the requirements set forth in this rule. Because it is
customary business practice that OEMs conduct and keep on file Failure
Mode and Effect Analysis (FMEA) on any potentially hazardous part or
system from the beginning of production of a car model until three or
more years after production of the model ends, we believe this
requirement will not impose an additional paperwork burden. However,
the Office of Management and Budget (OMB) has previously approved the
information collection requirements contained in the existing
regulations in subpart G of 40 CFR part 82 under the provisions of the
Paperwork Reduction Act, 44 U.S.C. 3501 et seq. and has assigned OMB
control numbers 2060-0226. The OMB control numbers for EPA's
regulations are listed in 40 CFR Part 9.
C. Regulatory Flexibility Act
The Regulatory Flexibility Act (RFA) generally requires an agency
to prepare a regulatory flexibility analysis of any rule subject to
notice and comment rulemaking requirements under the Administrative
Procedure Act or any other statute unless the agency certifies that the
rule will not have a significant economic impact on a substantial
number of small entities. Small entities include small businesses,
small organizations, and small governmental jurisdictions.
For purposes of assessing the impacts of today's rule on small
entities, small entity is defined as: (1) A small business as defined
by the Small Business Administration's (SBA) regulations at 13 CFR
121.201; for NAICS code 336111 (Automobile manufacturing), a small
business has < 1000 employees; for NAICS code 336391 (Motor Vehicle
Air-Conditioning Manufacturing), a small business has < 750 employees;
(2) a small governmental jurisdiction that is a government of a city,
county, town, school district or special district with a population of
less than 50,000; and (3) a small organization that is any not-for-
profit enterprise which is independently owned and operated and is not
dominant in its field.
After considering the economic impacts of today's final rule on
small entities, I certify that this action will not have a significant
adverse economic impact on a substantial number of small entities. The
only new requirement on small entities in this final rule is a
requirement specifying the type of unique service fittings required
when servicing MVAC systems using the refrigerant HFO-1234yf. Existing
regulations at appendix D to subpart G of 40 CFR part 82 already
require that there be unique service fittings for each refrigerant used
in MVAC systems. Thus, the costs of purchasing new unique fittings for
this refrigerant have already been imposed by the pre-existing
regulation. This rule specifies the requirements for which type of
unique fitting, in accordance with the fittings provided to EPA by the
manufacturer. These fittings are part of the SAE J639 standard. It is
not clear that there would be any cost differential between these
specific unique fittings
[[Page 17516]]
and others that the automotive industry could adopt instead. Thus, cost
impacts of this final rule on small entities are expected to be small.
This final rule is expected to relieve burden for some small entities,
such as car repair shops, by allowing them the flexibility to use a new
refrigerant that otherwise would have been prohibited under previous
requirements at appendix B to subpart G of 40 CFR part 82 and by
allowing them to use the easy-to-use ``quick-connect'' fittings for
this refrigerant. Other final rule requirements apply to original
equipment manufacturers, which are not small entities. These final rule
requirements are the least burdensome option for regulation.
Original equipment manufacturers are not mandated to move to MVAC
systems using HFO-1234yf. EPA is simply listing HFO-1234yf as an
acceptable alternative with use conditions in new MVAC systems. This
rule allows the use of this alternative to ozone-depleting substances
in the MVAC sector and outlines the conditions necessary for safe use.
By approving this refrigerant under SNAP, EPA provides additional
choice to the automotive industry which, if adopted, would reduce the
impact of MVACs on the global environment. This rulemaking does not
mandate the use of HFO-1234yf as a refrigerant in new MVACs.
D. Unfunded Mandates Reform Act
Title II of the Unfunded Mandates Reform Act of 1995 (UMRA), Public
Law 104-4, establishes requirements for Federal agencies to assess the
effects of their regulatory actions on State, local, and Tribal
governments and the private sector. Under section 202 of the UMRA, EPA
generally must prepare a written statement, including a cost-benefit
analysis, for proposed and final rules with ``Federal mandates'' that
may result in expenditures to State, local, and Tribal governments, in
the aggregate, or to the private sector, of $100 million or more in any
one year. Before promulgating an EPA rule for which a written statement
is needed, section 205 of the UMRA generally requires EPA to identify
and consider a reasonable number of regulatory alternatives and adopt
the least costly, most cost-effective or least burdensome alternative
that achieves the objectives of the rule. The provisions of section 205
do not apply when they are inconsistent with applicable law. Moreover,
section 205 allows EPA to adopt an alternative other than the least
costly, most cost-effective or least burdensome alternative if the
Administrator publishes with the final rule an explanation why that
alternative was not adopted. Before EPA establishes any regulatory
requirements that may significantly or uniquely affect small
governments, including Tribal governments, it must have developed under
section 203 of the UMRA a small government agency plan. The plan must
provide for notifying potentially affected small governments, enabling
officials of affected small governments to have meaningful and timely
input in the development of EPA regulatory proposals with significant
Federal intergovernmental mandates, and informing, educating, and
advising small governments on compliance with the regulatory
requirements.
EPA has determined that this rule does not contain a Federal
mandate that may result in expenditures of $100 million or more for
State, local, and Tribal governments, in the aggregate, or the private
sector in any one year. Today's rule does not affect State, local, or
Tribal governments. The enforceable requirements of today's rule
related to system design and documentation of the safety of alternative
MVAC systems affect only a small number of original equipment
manufacturers. Further, those requirements are consistent with
requirements that the automotive industry has already adopted through
consensus standards of SAE International. We expect that most
manufacturers of automobiles and MVAC systems would attempt to meet
those requirements or something very similar, even in the absence of
EPA's regulations. The only requirement that is applied more widely
than for original equipment manufacturers is a requirement specifying
the type of unique service fittings required when servicing MVAC
systems using the refrigerant HFO-1234yf. Existing regulations at
appendix D to subpart G of 40 CFR part 82 already require that there be
unique service fittings for each refrigerant used in MVAC systems. The
fittings required in this final rule are part of the SAE J639 standard.
Thus, the costs of this rule are consistent with standard industry
practice and are expected to be much less than $100 million per year.
This action provides additional options allowing greater
flexibility for industry in designing consumer products. The impact of
this rule on the private sector will be less than $100 million per
year. Thus, today's rule is not subject to the requirements of sections
202 and 205 of the UMRA. EPA has determined that this rule contains no
regulatory requirements that might significantly or uniquely affect
small governments. This regulation applies directly to facilities that
use these substances and not to governmental entities. This rule does
not mandate a switch to HFO-1234yf and the limited direct economic
impact on entities from this rulemaking is less than $100 million
annually.
E. Executive Order 13132: Federalism
Executive Order 13132, entitled ``Federalism'' (64 FR 43255, August
10, 1999), requires EPA to develop an accountable process to ensure
``meaningful and timely input by State and local officials in the
development of regulatory policies that have federalism implications.''
``Policies that have federalism implications'' is defined in the
Executive Order to include regulations that have ``substantial direct
effects on the States, on the relationship between the national
government and the States, or on the distribution of power and
responsibilities among the various levels of government.''
This action does not have federalism implications. It will not have
substantial direct effects on the States, on the relationship between
the national government and the States, or on the distribution of power
and responsibilities among the various levels of government, as
specified in Executive Order 13132. This regulation applies directly to
facilities that use these substances and not to governmental entities.
Thus, Executive Order 13132 does not apply to this rule.
F. Executive Order 13175: Consultation and Coordination With Indian
Tribal Governments
Executive Order 13175, entitled ``Consultation and Coordination
with Indian Tribal Governments'' (59 FR 22951, November 6, 2000),
requires EPA to develop an accountable process to ensure ``meaningful
and timely input by tribal officials in the development of regulatory
policies that have tribal implications.'' This final rule does not have
Tribal implications, as specified in Executive Order 13175. It does not
significantly or uniquely affect the communities of Indian Tribal
governments, because this regulation applies directly to facilities
that use these substances and not to governmental entities. Thus,
Executive Order 13175 does not apply to this rule.
G. Executive Order 13045: Protection of Children From Environmental
Health Risks and Safety Risks
This action is not subject to EO 13045 (62 FR 19885, April 23,
1997) because it is not economically significant as defined in EO
12866, and because the Agency does not believe the environmental health
or safety risks
[[Page 17517]]
addressed by this action present a disproportionate risk to children.
This action's health and risk assessments are discussed in sections V
and VII.D of the preamble and in documents EPA-HQ-OAR-2008-0664-0036
and HQ-OAR-2008-0664-0038 in the docket for this rulemaking.
H. Executive Order 13211: Actions Concerning Regulations That
Significantly Affect Energy Supply, Distribution, or Use
This action is not a ``significant energy action'' as defined in
Executive Order 13211 (66 FR 28355 (May 22, 2001)), because it is not
likely to have a significant adverse effect on the supply,
distribution, or use of energy. This action could impact manufacturing
and repair of MVAC systems using an alternative refrigerant. This rule
does not mandate a switch to HFO-1234yf. Preliminary information
indicates that these new systems are more energy efficient than
currently available systems in some climates. Therefore, we conclude
that this rule is not likely to have a significant adverse effect on
energy supply, distribution or use.
I. National Technology Transfer and Advancement Act
Section 12(d) of the National Technology Transfer and Advancement
Act of 1995 (``NTTAA''), Public Law 104-113, 12(d) (15 U.S.C. 272 note)
directs EPA to use voluntary consensus standards in its regulatory
activities unless to do so would be inconsistent with applicable law or
otherwise impractical. Voluntary consensus standards are technical
standards (e.g., materials specifications, test methods, sampling
procedures, and business practices) that are developed or adopted by
voluntary consensus standards bodies. NTTAA directs EPA to provide
Congress, through OMB, explanations when the Agency decides not to use
available and applicable voluntary consensus standards.
This rulemaking involves technical standards. EPA has decided to
use SAE International's most recent version of the SAE J1739 and SAE
J639 standards. These standards can be obtained from http://www.sae.org/technical/standards/. These standards address safety and
reliability issues in motor vehicle design, including MVAC systems
using alternative refrigerants.
J. Executive Order 12898: Federal Actions To Address Environmental
Justice in Minority Populations and Low-Income Populations
Executive Order (EO) 12898 (59 FR 7629 (Feb. 16, 1994)) establishes
Federal executive policy on environmental justice. Its main provision
directs Federal agencies, to the greatest extent practicable and
permitted by law, to make environmental justice part of their mission
by identifying and addressing, as appropriate, disproportionately high
and adverse human health or environmental effects of their programs,
policies, and activities on minority populations and low-income
populations in the United States.
EPA has determined that this final rule will not have
disproportionately high and adverse human health or environmental
effects on minority or low-income populations because it increases the
level of environmental protection for all affected populations without
having any disproportionately high and adverse human health or
environmental effects on any population, including any minority or low-
income population. HFO-1234yf is a non-ozone-depleting substance with a
low GWP. Based on the toxicological and atmospheric work described
earlier, HFO-1234yf will not have any disproportionately high and
adverse human health or environmental effects on any population,
including any minority or low-income population. This final rule
requires specific use conditions for MVAC systems, if car manufacturers
chose to make MVAC systems using this low GWP refrigerant alternative.
K. Congressional Review Act
The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the
Small Business Regulatory Enforcement Fairness Act of 1996, generally
provides that before a rule may take effect, the agency promulgating
the rule must submit a rule report, which includes a copy of the rule,
to each House of the Congress and to the Comptroller General of the
United States. EPA will submit a report containing this rule and other
required information to the U.S. Senate, the U.S. House of
Representatives, and the Comptroller General of the United States prior
to publication of the rule in the Federal Register. A Major rule cannot
take effect until 60 days after it is published in the Federal
Register. This action is not a ``major rule'' as defined by 5 U.S.C.
804(2). This rule will be effective May 31, 2011.
X. References
The documents below are referenced in the preamble. All documents
are located in the Air Docket at the address listed in section titled
ADDRESSES at the beginning of this document. Unless specified
otherwise, all documents are available in Docket ID No. EPA-HQ-OAR-
2008-0664 at http://www.regulations.gov.
Benesch et al., 2002. Investigation of Effects of Trifluoroacetate
on Vernal Pool Ecosystems. Environ. Tox and Chem. Vol. 21, No. 3 pp.
640-647. 2002. Available online at http://www3.interscience.wiley.com/journal/122678081/abstract?CRETRY=1&SRETRY=0.
Benouali et al., 2008. ``A/C System Control Strategies for Major
Refrigerant Options'' June 11, 2008, Alternative Refrigerant Systems
Symposium Phoenix, AZ. Available online at http://www2.dupont.com/Refrigerants/en_US/assets/downloads/SmartAutoAC/2008_SAE_ARSS_Valeo_Eval.pdf.
Besnard, S., 1996. Full Flammability Test of Gases and Gas Mixtures
in Air. CERN. European Organization for Nuclear Research. 1996.
Available online at http://cdsweb.cern.ch/record/1217583/files/CM-P00055900.pdf.
Boutonnet et al., 1999. ``Environmental Risk Assessment of
Trifluoroacetic Acid,'' Human and Ecological Risk Assessment, Feb.
1999. Available online at http://www.informaworld.com/smpp/
content~db=all~content=a922749285~frm=abslink.
CARB, 2008. Technical Support Document ``Staff Analysis on Emissions
and Economic Impact of Proposed Regulation for Small Containers of
Automotive Refrigerant.'' Appendix G to Certification Procedures for
Small Containers of Automotive Refrigerant. California Air Resources
Board, effective March 10, 2010. Document incorporated by reference
in California Code of Regulations (CCR), title 17, sections 95360
through 95370. Available online at http://www.arb.ca.gov/regact/2009/hfc09/hfc09.htm.
Carter, 2009. Investigation of Atmospheric Ozone Impacts of 2,3,3,3-
Tetrafluoropropene. Final report to Honeywell International Contract
UCR-09010016. William Carter, University of California, Riverside
CA. June 2, 2009. Available online at http://www.cert.ucr.edu/%7Ecarter/pubs/YFrept.pdf.
Ceviz and Yuksel, 2005. ``Cyclic variations on LPG and gasoline-
fuelled lean burn SI engine.'' Renewable Energy. In press. Available
online at http://www.pm-kbase.com/articles/LPGsdarticle(8).pdf.
Clodic et al., 2008. Evaluation of the Potential Impact of Emissions
of HFC-134a From Non Professional Servicing of Motor Vehicle Air
Conditioning Systems. D. Clodic, A. Tremoulet, Y, Riachi, D. Sousa,
L. Palandre, A. Garnier, S. Clodic and M. Lansard. Prepared under
CARB Agreement No. 06-341. December, 2008. Available online at
http://www.arb.ca.gov/research/apr/past/06-341.pdf.
CRP, 2008. Risk Assessment for Alternative Refrigerants HFO-1234yf
Phase II. Prepared for SAE International Cooperative Research
Program 1234 by Gradient Corporation. February 26, 2008. Docket
number EPA-HQ-OAR-2008-0664-0008.
[[Page 17518]]
CRP, 2009. Risk Assessment for Alternative Refrigerants HFO-1234yf
and R-744 (CO2) Phase III. Prepared for SAE International
Cooperative Research Program 1234 by T. Lewandowski, Gradient
Corporation. December 17, 2009. Docket number EPA-HQ-OAR-2008-0664-
0056.2.
DuPont, 2008. DuPont internal testing. Cited in docket number EPA-
HQ-OAR-2008-0664-0052.1.
Hamner Institutes, 2007. Toxicogenomic assessment of the
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[[Page 17519]]
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List of Subjects in 40 CFR Part 82
Environmental protection, Administrative practice and procedure,
Air pollution control, Incorporation by reference, Reporting and
recordkeeping requirements, Stratospheric ozone layer.
Dated: February 24, 2011.
Lisa P. Jackson,
Administrator.
For the reasons set out in the preamble, 40 CFR part 82 is amended
as follows:
PART 82--PROTECTION OF STRATOSPHERIC OZONE
0
1. The authority citation for part 82 continues to read as follows:
Authority: 42 U.S.C. 7414, 7601, 7671-7671q.
Subpart G--Significant New Alternatives Policy Program
0
2. Appendix B to Subpart G of Part 82 is amended as follows:
0
a. By adding one new entry to the end and by adding a note at the end
of the first table.
0
b. By revising the entry for ``CFC-12 Motor Vehicle Air Conditioners
(Retrofit and New Equipment/NIKs)'' in the table titled
``Refrigerants--Unacceptable Substitutes''.
The additions and revisions read as follows:
Appendix B to Subpart G of Part 82--Substitutes Subject to Use
Restrictions and Unacceptable Substitutes
[[Page 17520]]
Refrigerants--Acceptable Subject to Use Conditions
----------------------------------------------------------------------------------------------------------------
Application Substitute Decision Conditions Comments
----------------------------------------------------------------------------------------------------------------
* * * * * * *
CFC-12 Automobile Motor Vehicle HFO-1234yf as a Acceptable Manufacturers must Additional
Air Conditioning (New substitute for subject to use adhere to all of the training for
equipment in passenger cars CFC-12. conditions. safety requirements service
and light-duty trucks only). listed in the Society technicians
of Automotive recommended.
Engineers (SAE) Observe
Standard J639 requirements of
(adopted 2011), Significant New
including Use Rule at 40
requirements for: CFR 721.10182.
unique fittings, HFO-1234yf is
flammable refrigerant also known as
warning label, high- 2,3,3,3-
pressure compressor tetrafluoro-prop-
cutoff switch and 1-ene (CAS No
pressure relief 754-12-1).
devices. For
connections with
refrigerant
containers of 20 lbs
or greater, use
fittings consistent
with SAE J2844.
Manufacturers must
conduct Failure Mode
and Effect Analysis
(FMEA) as provided in
SAE J1739 (adopted
2009). Manufacturers
must keep the FMEA on
file for at least
three years from the
date of creation.
----------------------------------------------------------------------------------------------------------------
* * * * *
Note: The use conditions in this appendix contain references to
certain standards from SAE International. The standards are
incorporated by reference and the referenced sections are made part
of the regulations in part 82:
1. SAE J639. Safety Standards for Motor Vehicle Refrigerant
Vapor Compression Systems. February 2011 edition. SAE International.
2. SAE J1739. Potential Failure Mode and Effects Analysis in
Design (Design FMEA), Potential Failure Mode and Effects Analysis in
Manufacturing and Assembly Processes (Process FMEA). January 2009
edition. SAE International.
3. SAE J2844. R-1234yf (HFO-1234yf) New Refrigerant Purity and
Container Requirements for Use in Mobile Air-Conditioning Systems.
February 2011 edition. SAE International.
The Director of the Federal Register approves this incorporation
by reference in accordance with 5 U.S.C. 552(a) and 1 CFR part 51.
You may obtain a copy from SAE Customer Service, 400 Commonwealth
Drive, Warrendale, PA 15096-0001 USA; e-mail:
[email protected]; Telephone: 1-877-606-7323 (U.S. and Canada
only) or 1-724-776-4970 (outside the U.S. and Canada); Internet
address: http://store.sae.org/dlabout.htm.
You may inspect a copy at U.S. EPA's Air Docket; EPA West
Building, Room 3334; 1301 Constitution Ave., NW.; Washington, DC or
at the National Archives and Records Administration (NARA). For
questions regarding access to these standards, the telephone number
of EPA's Air Docket is 202-566-1742. For information on the
availability of this material at NARA, call 202-741-6030, or go to:
http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_ locations.html.
* * * * *
Refrigerants--Unacceptable Substitutes
----------------------------------------------------------------------------------------------------------------
End-use Substitute Decision Comments
----------------------------------------------------------------------------------------------------------------
* * * * * * *
CFC-12 Motor Vehicle Air R-405A................ Unacceptable.......... R-405A contains R-c318, a
Conditioners (Retrofit and New PFC, which has an
Equipment/NIKs). extremely high GWP and
lifetime. Other
Substitutes exist which do
not contain PFCs.
----------------------------------------------------------------------------
Hydrocarbon Blend B... Unacceptable.......... Flammability is a serious
concern. Data have not
been submitted to
demonstrate it can be used
safely in this end-use.
----------------------------------------------------------------------------
Flammable Substitutes, Unacceptable.......... The risks associated with
other than R-152a or using flammable
HFO-1234yf in new substitutes (except R-152a
equipment. and HFO-1234yf) in this
end-use have not been
addressed by a risk
assessment. R-152a and HFO-
1234yf may be used in new
equipment with the use
conditions in appendix B
to this subpart.
----------------------------------------------------------------------------------------------------------------
[FR Doc. 2011-6268 Filed 3-28-11; 8:45 am]
BILLING CODE 6560-50-P