[Federal Register Volume 71, Number 183 (Thursday, September 21, 2006)]
[Proposed Rules]
[Pages 55140-55149]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 06-7967]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 82
[EPA-HQ-OAR-2004-0488; FRL-8221-5]
RIN 2060-AM54
Protection of Stratospheric Ozone: Listing of Substitutes in the
Motor Vehicle Air Conditioning Sector Under the Significant New
Alternatives Policy (SNAP) Program
AGENCY: Environmental Protection Agency.
ACTION: Proposed rule.
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SUMMARY: Under mandate from the Clean Air Act to review and approve
alternatives to ozone-depleting substances, the Environmental
Protection Agency (EPA) proposes to expand and amend the list of
acceptable substitutes for ozone-depleting substances (ODS) through the
Significant New Alternatives Policy (SNAP) program. Substitutes
addressed in this proposal are for the motor vehicle air conditioning
(MVAC) end-use within the refrigeration and air-conditioning sector.
The proposed substitutes are non ozone-depleting gases and consequently
do not contribute to stratospheric ozone depletion.
DATES: Comments must be received on or before October 23, 2006. Any
person interested in requesting a public hearing, must submit such
request on or before October 6, 2006. If a public hearing is requested,
a separate notice will be published announcing the date and time of the
public hearing and the comment period will be extended until 30 days
after the public hearing to allow rebuttal and supplementary
information regarding any material presented at the public hearing.
Inquires regarding a public hearing should be directed to the contact
person listed below.
ADDRESSES: Submit your comments, identified by Docket ID No. EPA-HQ-
OAR-2004-0488, by one of the following methods:
Federal eRulemaking Portal: http://www.regulations.gov.
Follow the online instructions for submitting comments.
E-mail: [email protected].
Fax: (202) 566-1741.
Mail: Environmental Protection Agency, EPA Docket Center
(EPA/DC), Mailcode 6102T, Attention Docket ID No. EPA-HQ-OAR-2004-0488,
1200 Pennsylvania Avenue, NW., Washington, DC 20460.
Hand Delivery: Public Reading Room, Room B102, EPA West
Building, 1301 Constitution Avenue, NW., Washington, DC.
Such deliveries are only accepted during the Docket's normal hours
of operation, and special arrangements should be made for deliveries of
boxed information.
Instructions: Direct your comments to Docket ID No. EPA-HQ-OAR-
2004-0488. EPA's policy is that all comments received will be included
in the public docket without change and may be made available online at
www.regulations.gov, including any personal information provided,
unless the comment includes information claimed to be Confidential
Business Information (CBI) or other information whose disclosure is
restricted by statute. Do not submit information that you consider to
be CBI or otherwise protected through www.regulations.gov or e-mail.
The www.regulations.gov Web site is an ``anonymous access'' system,
which means EPA will not know your identity or contact information
unless you provide it in the body of your comment. If you send an e-
mail comment directly to EPA without going through www.regulations.gov
your e-mail address will be automatically captured and included as part
of the comment that is placed in the public docket and made available
on the Internet. If you submit an electronic comment, EPA recommends
that you include your name and other contact information in the body of
your comment and with any disk or CD-ROM you submit. If EPA cannot read
your comment due to technical difficulties and cannot contact you for
clarification, EPA may not be able to consider your comment. Electronic
files should avoid the use of special characters, any form of
encryption, and be free of any defects or viruses.
Docket: All documents in the docket are listed in the
www.regulations.gov index. Although listed in the index, some
information is not publicly available, e.g., CBI or other information
whose disclosure is restricted by statute. Certain other material, such
as copyrighted material, will be publicly available only in hard copy.
Publicly available docket materials are available either electronically
in www.regulations.gov or in hard copy at the Air Docket, EPA/DC, EPA
West, Room B102, 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: For further information about this
proposed rule, contact Karen Thundiyil by telephone at (202) 343-9464,
or by e-mail 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/regs. For copies of the full list of SNAP
decisions in all industrial sectors, contact the EPA Stratospheric
Protection Hotline at (800) 296-1996. You also can find a complete
chronology of SNAP decisions and the appropriate Federal Register
citations at EPA's Stratospheric Ozone Web site at http://www.epa.gov/ozone/snap/chron.html.
SUPPLEMENTARY INFORMATION: This proposed action, if finalized, would
provide motor vehicle manufacturers and their suppliers an additional
refrigerant option for motor vehicle air conditioning systems. This
proposed action would also modify the current acceptability of an
approved substitute to include use conditions. The two refrigerants
discussed in this proposed action are non ozone-depleting substances.
Car manufacturers, component manufacturers and the MVAC service
industry have all been actively engaged in the development of this
rulemaking and are developing prototype systems with the use
[[Page 55141]]
conditions defined in this proposed rulemaking.
Table of Contents
I. Section 612 Regulatory Background
A. Rulemaking
B. Listing of Unacceptable/Acceptable Substitutes
C. Petition Process
D. 90-day Notification
E. Outreach
F. Clearinghouse
II. Summary of Acceptability Determinations
III. SNAP Criteria for Evaluating Alternatives
IV. Carbon Dioxide MVAC Systems
A. Occupant Exposure
B. Service Technician Exposure
C. Environmental Information
D. Acceptability Determination
V. HFC-152a MVAC Systems
A. Toxicity and Flammability
B. Service Technician Exposure
C. Environmental Information
D. Acceptability Determination
VI. Other Use Conditions Applicable to Motor Vehicle Air
Conditioning Systems
VII. Statutory and Executive Order Reviews
A. Executive Order 12866: Regulatory Planning and Review
B. Paperwork Reduction Act
C. Regulatory Flexibility Act (RFA)
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
VIII. References
I. Section 612 Regulatory Background
Section 612 of the Clean Air Act (CAA) authorizes EPA to develop a
program for evaluating alternatives to ozone-depleting substances. EPA
refers to this program as the Significant New Alternatives Policy
(SNAP) program. The major provisions of section 612 are:
A. Rulemaking
Section 612(c) requires EPA to promulgate rules making it unlawful
to replace any class I (e.g., chlorofluorocarbon, halon, carbon
tetrachloride, methyl chloroform, methyl bromide, and
hydrobromofluorocarbon) or class II (e.g., 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.
B. Listing of Unacceptable/Acceptable Substitutes
Section 612(c) also 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.
C. 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.
D. 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.
E. 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.
F. 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.
On March 18, 1994, EPA published the original rulemaking (59 FR
13044) which described the process for administering the SNAP program
and issued EPA's first acceptability lists for substitutes in the major
industrial use sectors. These sectors include: Refrigeration and air
conditioning; foam blowing; solvents cleaning; 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
ozone-depleting substances.
For the purposes of SNAP, the Agency defines a ``substitute'' as
any chemical, product substitute, or alternative manufacturing process,
whether existing or new, intended for use as a replacement for a class
I or class II substance. Anyone who produces a substitute must provide
the Agency with health and safety studies on the substitute at least 90
days before introducing it into interstate commerce for significant new
use as an alternative. This requirement applies to substitute
manufacturers, but may include importers, formulators, or end-users,
when they are responsible for introducing a substitute into commerce.
You can find a complete chronology of SNAP decisions and the
appropriate Federal Register citations at EPA's Stratospheric Ozone Web
site at http://www.epa.gov/ozone/snap/chron.html. This information is
also available from the Air Docket (see Addresses section above for
contact information).
II. Summary of Acceptability Determinations
EPA proposes to find HFC-152a and CO2, with use
conditions acceptable refrigerant substitutes as replacements for CFC-
12 in motor vehicle air conditioning (MVAC) systems. This determination
applies to MVAC systems in newly manufactured vehicles. This
acceptability determination does not apply to MVAC systems that were
retrofitted to use HFC-134a and might be again retrofitted to either
HFC-152a or CO2; nor to MVAC systems that initially were
manufactured to use HFC-134a and that might be retrofitted to use HFC-
152a and CO2. The HFC-152a and CO2 acceptability
determinations are based on the results of risk screens and national
safety standards.
In the original SNAP rulemaking,\1\ CO2 was found
acceptable in new motor vehicle air conditioning systems, but EPA did
not at that time base acceptability on use conditions now required by
this rule. For various reasons, CO2 MVAC technology
development took longer than anticipated and currently, no car
manufacturer has put CO2 MVAC systems in production vehicles
for general consumer use. However, manufacturers are developing
prototype air conditioning (A/C) systems that use CO2 and
HFC-152a for motor vehicles sold in some foreign and domestic markets.
This rule would facilitate and allow commercial deployment of the new
refrigerants, but leaves refrigerant choice to the market. Since the
original SNAP rulemaking, the risks of CO2 in a MVAC system
without risk mitigation
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strategies have been explored and examined. Now, informed with a new
risk screen, the SNAP program has determined that the risks of
CO2 will be comparable to the risks of HFC-134a only if use
conditions are implemented.
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\1\ 59 FR 13044; March 18, 1994.
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In making the acceptability determinations, EPA assessed the impact
of both HFC-152a and CO2 systems on human health and the
environment; the focus was on the risks of exposure to potentially
hazardous levels of refrigerant for both vehicle occupants and vehicle
service technicians and how those risks compare to those associated
with use of HFC-134a in MVACs.\2\ EPA identified scenarios where there
was potential for a leak into the passenger compartment and potential
for technicians to be exposed during servicing. EPA's review found that
a foreseeable worst case scenario leak into the passenger compartment
from either HFC-152a or CO2 air conditioning systems might
lead to passenger exposures above risk levels associated with HFC-134a
systems. However, safety devices could be added or engineered into new
systems so that potentially hazardous concentrations could be avoided,
making the risk comparable to that associated with HFC-134a systems.
Therefore, EPA is listing HFC-152a and CO2 as acceptable
with the use condition that engineering devices or mitigation
strategies be employed so that in the event of a leak, the resulting
concentrations of refrigerant in the free space and vehicle occupant
breathing zone within the interior car compartment are maintained at
safe levels. Air conditioning systems with two or more evaporators will
generally have larger refrigerant charges and therefore will require
more elaborate safety mitigation devices and/or strategies. Other
organizations and industry groups that have assessed risks associated
with HFC-152a and/or CO2 MVAC systems have also concluded
that risk mitigation strategies in some form are
necessary.3 4
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\2\ The predominant air conditioning refrigerant in newly
manufactured motor vehicles is HFC-134a. In listing HFC-134a as an
acceptable substitute, EPA found that exposure in motor vehicles
would fall far below a threshold of concern (EPA, 1994).
\3\ RISA, 2002.
\4\ Rebinger, 2005.
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EPA's analysis also found that the probability of potentially
dangerous exposures is higher for service technicians than for
passengers, but within the level of risk that technicians currently
accept as part of their job. EPA recommends that service technicians
receive additional training so they are knowledgeable about the
different hazards associated with working on HFC-152a and
CO2 systems when compared to HFC-134a systems. Consistent
with Society of Automotive Engineer's Standard J639, prominent labeling
of A/C systems with warning of ``High Pressure CO2'' and
``Flammable Refrigerant'' is required. In addition, the SNAP
regulations require unique fittings for the two A/C refrigerants which
will prevent accidents associated with adding refrigerant to the wrong
type of A/C system.
The following sections present a more detailed discussion of the
EPA's acceptability decisions for HFC-152a and CO2 MVAC
systems. The listing decisions are summarized in Appendix B. The
statements in the ``Comments'' column of the table in Appendix B
provide additional information that is not legally binding under
section 612 of the CAA. However, these statements may include
information about binding requirements under other programs.
Nevertheless, EPA strongly encourages users to use these substitutes in
a manner consistent with the recommendations in the ``Comments''
section. In many instances, the comments simply refer to standard
workplace safety practices that have already been identified in
existing industry standards. Thus, many of these recommendations, if
adopted, would not require significant changes in existing operating
practices for the affected industry. Such recommendations should not be
considered comprehensive with respect to legal obligations that may
pertain to the use of the substitute.
III. SNAP Criteria for Evaluating Alternatives
When making acceptability decisions, EPA has considered toxicity,
flammability, the potential for occupational and general population
exposure, and environmental effects including ozone depletion
potential, atmospheric lifetime, impacts on local air quality, and
ecosystem effects of the alternatives. EPA evaluated the criteria set
forth at 40 CFR 82.180(a)(7) in determining whether HFC-152a and
CO2 are acceptable refrigerant substitutes for CFC-12 in the
motor vehicle air conditioning sector. The Agency has determined that
the Clean Air Act does not authorize EPA to regulate for global climate
change purposes (Fabricant, 2003). EPA has not yet concluded how this
determination would affect its consideration of the global warming
potential of substitutes under the SNAP program. Regardless, for the
substitutes considered here, the global warming potential (GWP) of the
alternatives was not a determinative factor in EPA's acceptable subject
to use conditions determination. The GWP for these substitutes is well
below that of previously approved substitutes in this sector.
The data described below indicates that use of HFC-152a and
CO2 with risk mitigation technologies does not pose greater
risks compared to other substitutes approved in the MVAC sector.\5\ The
review focused on the potential for hazardous exposures to the
refrigerants for vehicle occupants and for service technicians.
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\5\ The predominant substitute in the MVAC sector is HFC-134a.
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EPA and the U.S. Army (Research Development and Engineering
Command) collaborated on analyzing the probability that HFC-152a or
CO2 leaks into the passenger compartment would expose
occupants to refrigerant concentration levels that could lead to driver
performance decrements, adverse effects on passengers, or flammable
concentrations of refrigerant. The flow of refrigerant into the
passenger compartment was modeled using three-dimensional computational
fluid dynamics (CFD) to predict localized refrigerant concentrations
over time that would result from a leak.\6\ A typical six passenger
sedan \7\ was modeled under a broad range of MVAC system operating
modes (e.g., air conditioning on or off, fan on low or high, 100%
recirculated air or 100% outside air), including worst case scenarios
that would result in the maximum possible leak rate. The analysis
assessed the potential frequency of vehicle occupant and technician
exposure to elevated levels of CO2 and HFC-152a using
``fault tree analysis'' (FTA) which EPA has previously used to assess
frequency and potential consequences of HFC-134a refrigerant releases
(Jetter et al., 2001). The analysis quantified the potential for
occupant exposure as a result of a range of leak scenarios and usage
modes where no risk mitigation systems were engineered into the A/C
systems, as well as scenarios that included engineering technology to
reduce exposures. The probability of exposure during servicing was
assessed for trained technicians and for untrained ``do-it-
yourselfers'' (DIYers) in a variety of work situations.
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\6\ The U.S. Army CFD model was previously developed for risk
assessment of other chemicals.
\7\ Modeling assumed 6 adult passengers in the car.
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In this rulemaking, CO2 and HFC-152a risks are
considered in relation to the risks associated with the predominant
ozone-depleting substance (ODS) refrigerant substitute in MVACs, HFC-
134a. HFC-134a is a non-flammable, low toxicity refrigerant. The
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EPA's SNAP program does not require that new substitutes be found risk-
free to be found acceptable. In reviewing the acceptability of proposed
substitutes, EPA considers how each substitute can be used within a
specific application and the resulting risks and uncertainties
surrounding potential health and environmental effects. The EPA does
not want to intercede in the market's choice of available substitutes,
unless a proposed substitute is clearly more harmful to human health
and the environment than other alternatives.
CO2 and HFC-152a MVAC systems are not yet commercially
available. In the absence of empirical data, EPA selected upper bound
values for the fault tree probability inputs that would tend to lead to
higher estimates of equipment failure or leak rates (i.e., worst case
scenarios), and therefore higher probabilities of passenger exposures
than might typically be encountered, such as using a car with a high
ratio of refrigerant charge size to passenger compartment volume.
IV. Carbon Dioxide MVAC Systems
A. Occupant Exposure
Numerous studies indicate that a spectrum of health effects are
associated with increasing CO2 exposures. These health
effects range from symptomatic effects to death (EPA, 2005).
Individuals exposed to CO2 concentrations as low as 4-5%
over a few minutes reported headache, uncomfortable breathing and
dizziness (Schulte, 1964; Schneider and Truesdale, 1922; Patterson et
al., 1955). Significant performance degradation (e.g., reaction time)
was noted in pilots exposed to 5% CO2 (Wamsley et al., 1975,
cited in Wong, 1992). Individuals exposed to 6% CO2 for
periods as short as two minutes had hearing and visual disturbances
(Gellhorn, 1936), and significant reasoning and performance decrements
have been observed in healthy young adults after exposures of 5 minutes
to 7.5% CO2 (Sayers, 1987). Concentrations of 10%
CO2 and higher can cause loss of consciousness, seizures, or
even death (Hunter, 1975; Lambertsen, 1971; OSHA, 1989).
Elevated CO2 concentrations can result from human
respiration in a sealed space, such as a car, without the introduction
of fresh air. For example, after 60 minutes in a sub-compact car with
four adult passengers and the A/C system in recirculation mode, the
total CO2 concentration is estimated to be approximately
2.4% (EPA, 2005). In designing their systems and necessary mitigation
devices, original equipment manufacturers (OEMs) should account for
potentially elevated background CO2 concentrations that can
result without a discharge of CO2 into the passenger
compartment.
1. Upper Limit for Vehicle Occupant Exposure
In proposing the upper CO2 limit for vehicle occupant
exposure, EPA relied on guidance from National Institute for
Occupational Safety and Health (NIOSH) of the Centers for Disease
Control and Prevention. Based on adverse effects associated with
overexposure to CO2 ranging from rapid breathing and heart
palpitations, headache, sweating, shortness of breath and dizziness, to
convulsions and death, NIOSH has adopted a Recommended Exposure Limit
(REL) for short-term CO2 exposure of 3% averaged over 15
minutes. NIOSH's REL for short-term CO2 exposure is the same
as the American Conference of Governmental Industrial Hygienists
(ACGIH) short-term exposure limit (STEL) for CO2.
EPA focused on short-term passenger exposures for three reasons.
First, occupants experiencing decreased cooling of the A/C system as a
result of refrigerant leaks may also respond by opening windows or
increasing fan speed. The introduction of outside air by a vehicle
occupant would mix with discharged CO2 and dilute a
potentially hazardous concentration. The second reason is that average
trip duration is about 30 minutes.\8\ The third reason is that vehicle
occupants who start to experience abnormal breathing or other
physiological effects of CO2 exposure will likely react by
increasing the fan speed or opening windows to increase their comfort
level by reducing the sense of stuffiness. EPA proposes that direct
loop refrigerant systems that have the potential for release of
refrigerant into the occupant compartment or the A/C air distribution
system, must have safety mitigation necessary to prevent concentrations
higher than the CO2 STEL (3% averaged over 15 minutes). EPA
seeks comment on this use condition and also whether a maximum
CO2 ceiling in the breathing zone should be applied in
addition to the 3% free space limit averaged over 15 minutes. A
breathing zone ceiling may provide additional assurance regarding
vehicle driver alertness. Public comments suggesting a breathing zone
ceiling should specify the suggested level, justified by literature
from scientific, safety standard, and other sources published
worldwide.
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\8\ Atkinson, 2002.
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2. Potential Occupant Exposure With No Safety Mitigation
Computational fluid dynamics (CFD) modeling demonstrated where peak
concentrations of refrigerant could appear in the passenger compartment
as a result of different leak events, and whether those peaks are
likely to be above the CO2 STEL. U.S. Army modeling
conducted as part of the EPA risk analysis indicated that
CO2 leaks in a stationary or slowly moving vehicle in full
recirculation mode, without mitigation devices or other safety features
could result in peak concentrations of about 10% and levels above 6%
for roughly an hour which are well above the CO2 STEL.
3. Occupant Exposure With Risk Mitigation
The analyses indicate that direct expansion CO2 systems
without additional safety features could result in vehicle occupant
exposures above the CO2 STEL. However, based on the U.S.
Army CFD modeling, properly engineered safety systems added to
CO2 systems can reduce the chance of occupant exposure to
levels above the CO2 STEL, thus making the risks of
CO2 comparable to HFC-134a. EPA is interested in comment on
the adequacy of available mitigation systems for CO2 in
minimizing risks to passengers.
One possible strategy to limit refrigerant leakage into occupied
passenger space is to detect the leak and activate a device referred to
as a ``squib valve'' to vent the CO2 to a location outside
of the passenger compartment, such as a wheel well or tail pipe. The
CFD modeling estimated peak concentrations in the passenger compartment
when a squib valve is used to evacuate the refrigerant charge. The U.S.
Army CFD modeling conducted to date indicates that when the squib valve
is activated within 10 seconds after a leak event is detected, the
maximum concentration remains well below the CO2 STEL. The
Agency is interested in comment on whether a squib valve activation
faster than 10 seconds would be needed, or whether any squib valve
technology is sufficient to protect against possible adverse effects
associated with very brief (e.g., 5 second) potentially elevated
exposures (e.g., 5-10% CO2), and the likelihood that
occupants would encounter such high exposures.
Another way to reduce CO2 exposure would be to increase
the amount of outside air that is introduced to the car. CFD modeling
revealed that when the A/C system uses 100% outside air, as opposed to
recirculated air, CO2 levels
[[Page 55144]]
remained below the CO2 STEL after a foreseeable worst case
scenario leak.\9\
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\9\ Although this would effectively mitigate safety hazards
there would likely be a large fuel efficiency penalty if this
strategy were used since the system would not use recirculated air
at all.
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Other potential risk mitigation strategies that reduce the
likelihood of exceeding the CO2 STEL in the free space of
the passenger compartment include:
Eliminating the possibility of passenger exposure by
separating the refrigerant from the passenger compartment with
secondary loop systems.
Evaporator isolation valves whose default position is
closed. Such valves would allow only a fraction of the total charge to
be released into the passenger compartment in the event of a leak.
Close-coupled or hermetically sealed systems that would
both reduce charge size and decrease the possibility of a leak event.
Automatic increases in the air exchange in the passenger
compartment upon detection of leaks.
Automatic venting of refrigerant outside the passenger
compartment in the air exchange of the passenger compartment upon
detection of leaks.
The Agency is interested in comment on whether these risk
mitigation strategies are technically feasible, considering fuel
efficiency and overall system performance criteria.
B. Service Technician Exposure
Risks to service personnel from CO2 systems can result
from the high pressure of the systems. Carbon dioxide A/C systems are
high-pressure systems that require service personnel to take safety
precautions and measures. Injury could occur as a result of the
potentially high force of an unexpected failure of system components or
from gas escaping during parts disassembly.
Risks to service personnel from CO2 systems can also
come about from overexposure to CO2 in an unexpected system
release. Because CO2 is heavier than air, the gas will sink
and could cause high concentrations in low lying areas such as service
pits. Service technicians should be aware of the potential for
CO2 build-up in these areas and protect against exposure to
high concentrations. The Occupational Safety and Health Administration
(OSHA) Permissible Exposure Limit (PEL) for CO2 is 5,000
parts per million (ppm) (or 0.5%) over an eight hour time weighted
average.
EPA analysis revealed that the risk of potentially hazardous
exposure to CO2 as a result of working on MVAC systems is
within the level of risk service technicians currently accept as part
of their job. Technicians handle high pressure gases such as
CO2 on a daily basis. However, it is recommended that
service technicians become knowledgeable about the hazards associated
with CO2 systems and that additional training be provided.
``Do-it-yourself'' repairers (DIYers) working with CO2
systems face the risks of working with high pressure, including
potentially high force from an unexpected leak from the system or a
CO2 tank. Consistent with Society of Automotive Engineers
(SAE) J639 Standard, CO2 systems must be labeled with a
nameplate or tag indicating the air conditioning system is under high
pressure and should only be serviced by qualified personnel. These
labels combined with unique fittings for CO2 systems are
expected to help mitigate potential for risk or injury to DIYers.
C. Environmental Information
Carbon dioxide has an ozone depletion potential (ODP) of zero. The
original ozone depleting substance in MVACs, CFC-12, has an ODP of
1.\10\ The predominant MVAC substitute, HFC-134a has an ODP of
zero.\11\ Carbon dioxide, CFC-12, and HFC-134a are all excluded from
the definition of volatile organic compound (VOC) under CAA 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.
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\10\ World Meteorological Organization (WMO) Science Assessment
of Ozone Depletion, 2002.
\11\ WMO Science Assessment of Ozone Depletion, 2002.
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D. Acceptability Determination
EPA proposes to list CO2 acceptable with the use
condition that MVAC systems are designed so that occupant exposure to
concentrations above the CO2 STEL of 3% averaged over 15
minutes are avoided, even in the event of a leak. We request comment on
whether a maximum ceiling CO2 level should be applied in the
driver and passenger breathing zone and the scientific basis for such a
limit. The addition of the squib valve/directed release system is one
possible strategy for mitigating risk for CO2 systems. Other
mitigation strategies may also prove equally or more effective.
Prominent labeling of CO2 MVAC systems with a warning
such as ``CAUTION SYSTEM CONTAINS HIGH PRESSURE CARBON DIOXIDE
(CO2)--TO BE SERVICED ONLY BY QUALIFIED PERSONNEL'' is
required. Consistent with Society of Automotive Engineers (SAE) J639
Standard, this label should be mounted in the engine compartment on a
component that is not normally replaced and where it can be easily
seen. This label must include CO2 identification information
and indicate that CO2 is potentially toxic.
Original equipment manufacturers (OEMs) are required to keep
records of the tests they perform to ensure that MVAC systems are safe
and are designed with sufficient safety mitigation devices to ensure
that occupants are not exposed to levels above the CO2 STEL
under foreseeable circumstances. Presently, no standard test procedure
exists to determine that concentrations of concern are not exceeded.
EPA is working with SAE to develop these test standards and expects
them to be in place by the time that CO2 MVAC systems are
deployed in U.S. vehicles. Other use conditions are already established
in Appendix D to subpart G of 40 CFR part 82 that are applicable to all
substitute refrigerants in MVAC systems (e.g., unique fittings and
labels).
V. HFC-152a MVAC Systems
A. Toxicity and Flammability
The American Industrial Hygienists Association (AIHA) Workplace
Environmental Exposure Limit (WEEL) (8 hour time weighted average) for
HFC-152a is 1000 ppm (0.1% v/v), the highest occupational exposure
limit allowed under standard industrial hygiene practices for any
industrial chemical. The toxicity profile of HFC-152a is comparable to
CFC-12 and its most prevalent substitute, HFC-134a. The lowest observed
adverse effect level for HFC-152a toxicity (15%) is above the level of
flammability concern, discussed below, so protecting against flammable
concentrations protects against toxic conditions as well.
A wide range of concentrations has been reported for HFC-152a
flammability where the gas poses a risk of ignition and fire (3.7%-20%
by volume in air) (Wilson, 2002). Different test conditions, impurities
and the measurement approach can all contribute to the range of
flammable concentrations of HFC-152a. The lower flammability limit
(LFL) for HFC-152a has been tested by many laboratories using different
testing protocols with results ranging from 3.7% to 4.2%. EPA selected
the lowest reported LFL to assess the potential for passenger exposure
and predict localized pockets of refrigerant concentrations within the
passenger compartment. This selection increases confidence that the
substitute
[[Page 55145]]
is regulated in a manner that is protective of the general population.
Protecting against flammable concentrations of HFC-152a also
protects against toxic conditions because the lowest observed adverse
effect level (LOAEL) of HFC-152a is far above the level of flammability
concern.
1. Upper Limit of Occupant Exposure
The lowest reported LFL for HFC-152a is 3.7%, which EPA considers
to pose a fire hazard to occupants and technicians. To assess the
potential for passenger exposure and predict localized pockets of
greater refrigerant concentrations in specific locations within the
passenger compartment, EPA used 3.7% as the upper limit of occupant
exposure.
The upper limit of occupant exposure to HFC-152a protects against
the possibility of flammability. It is important to note that when
burned or exposed to high heat, HFC-152a like all fluorocarbons
including CFC-12 and HFC-134a, forms acid byproducts including
hydrofluoric acid (HF)--a severe respiratory irritant.\12\ OSHA has set
a Permissible Exposure Limit (PEL) 8-hour occupational exposure limits
for HF at 3 ppm which is the upper allowable limit for worker exposure.
Passenger exposure to HF could only occur as a result of a large leak
in the presence of an ignition source. EPA's approach in the risk
screen and in setting use conditions is to prevent any fire risk
associated with HFC-152a use in MVAC systems, which would also prevent
any potential passenger exposure to HF.
---------------------------------------------------------------------------
\12\ These decomposition products have a sharp, acrid odor even
at concentrations of only a few parts per million.
---------------------------------------------------------------------------
2. Potential Occupant Exposure With No Safety Mitigation
U.S. Army computational fluid dynamics (CFD) modeling simulated
various leakage scenarios into the passenger compartment and the
potential for occupant exposures. As an initial screening tool,
simplified modeling was conducted by assuming uniform mixing of
passenger compartment air. This type of modeling does not account for
the pockets of flammable refrigerant that can occur. The results
indicate that concentrations of HFC-152a that are roughly one-half the
lower flammable limit (2%) would be reached in all recirculation modes
(at various fan speeds and A/C on and off) for a stationary vehicle.
More complex modeling showed that localized concentrations exceeding
the LFL would occur with minimal mitigation (see below). Therefore,
this substitute would pose increased risk compared to HFC-134a in the
absence of sufficient mitigation technology.
3. Occupant Exposure With Safety Mitigation
U.S. Army CFD modeling included in the risk analysis indicates that
occupant exposures could be reduced if risk mitigation technology was
incorporated that reduced the amount of HFC-152a that entered the
passenger compartment in the event of a leak.
A 10-second squib valve activation time in a HFC-152a system
resulted in estimated localized concentrations greater than 3.7% v/v in
close proximity to the vent for a total of 14 seconds. In comparison, a
HFC-152a system with no squib valve resulted in estimated localized
concentrations greater than 3.7% v/v in close proximity to the vent for
35 seconds. Given the very small areas and time frames of potential
exposures involved, EPA believes that 10 seconds is an appropriate
upper bound for the valve activation time, unless the system design can
also ensure a lower release rate. EPA is interested in comments on
whether a squib valve activation faster than 10 seconds is necessary,
or whether any squib valve technology is sufficient to prevent
potentially hazardous concentrations (i.e., greater than 3.7% for 15
seconds).
We also assessed the introduction of outside air through the A/C
system to investigate whether this would be useful in hazard
mitigation. CFD modeling showed that potentially flammable
concentrations would exist for 5 minutes with the introduction of 50%
outside air, and for 3 minutes with 100% outside air using the
simplified modeling. While the introduction of outside air alone does
not yield acceptable outcomes, introducing some outside air at all
times in addition to another mitigation strategy may be a viable
option.
Other potential risk mitigation strategies that reduce the
likelihood of exceeding the HFC-152a LFL of 3.7% for more than 15
seconds may include:
Eliminating the possibility of HFC-152a in the passenger
compartment by placing the refrigerant only in the engine compartment
with secondary loop systems.
Evaporator isolation valves whose default position is
closed. Such valves would allow only a fraction of the total charge to
be released into the passenger compartment in the event of a leak.
Close-coupled or hermetically sealed systems that would
both serve to reduce charge size and decrease the possibility of a leak
event.
Automatic increases in the air exchange in the passenger
compartment upon detection of leaks.
Automatic venting of HFC-152a outside the passenger
compartment in the air exchange of the passenger compartment upon
detection of leaks.
The Agency is interested in comment on whether these risk
mitigation strategies are technically feasible, considering fuel
efficiency and overall system performance criteria.
B. Service Technician Exposure
Fault Tree Analysis (FTA) found that the risk of potentially
hazardous exposure to HFC-152a is higher for service technicians than
for occupants driving in vehicles with no safety mitigation technology.
The AIHA occupational exposure limit for HFC-152a is 1000 ppm (0.1% v/v
averaged over 8-hours). The risk of exposure while servicing vehicles
depends not only on the number of vehicles a given service technician
or shop handles, but also on service technician experience and
training. With proper mitigation and training, the frequency of these
exposures can be reduced dramatically. Further, EPA believes, based on
input from service technicians, the flammability potential of HFC-152a
is within the level of risk technicians currently accept as part of
their job. Technicians handle flammables comparable to HFC-152a on a
daily basis. It is recommended however, that additional training be
provided to service technicians so that they are knowledgable about the
different hazards associated with working on HFC-152a systems compared
to CFC-12 or HFC-134a systems. EPA is currently working with A/C
service and technical associations to anticipate new systems and to
modify training, as needed.
``Do-it-yourself'' repairers (DIYers) working with HFC-152a systems
face the risks of working with a slightly flammable substance.
Consistent with Society of Automotive Engineers (SAE) J639 Standard,
HFC-152a systems should be labeled with a nameplate or tag indicating
the air conditioning system is under high pressure and should only be
serviced by qualified personnel. These labels combined with unique
fittings for HFC-152a systems are expected to help mitigate potential
for risk or injury to DIYers.
[[Page 55146]]
C. Environmental Information
HFC-152a has an ODP of zero.\13\ The original ozone depleting
substance in MVACs, CFC-12, has an ODP of 1. The predominant MVAC
substitute, HFC-134a has an ODP of zero.\14\ HFC-152a, CFC-12, and HFC-
134a all are excluded from the definition of VOC under CAA 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
---------------------------------------------------------------------------
\13\ WMO Science Assessment of Ozone Depletion, 2002.
\14\ WMO Science Assessment of Ozone Depletion, 2002.
---------------------------------------------------------------------------
D. Acceptability Determination
Within the refrigeration and air-conditioning sector, EPA proposes
to find HFC-152a acceptable with the use condition that MVAC systems
are designed so that foreseeable leaks into the passenger compartment
do not result in HFC-152a concentrations at or above the lowest LFL of
3.7% for more than 15 seconds. EPA seeks comment on whether 15 seconds
is sufficiently protective. The addition of the squib valve/directed
release system is one effective strategy for mitigating risk for HFC-
152a systems. Other mitigation strategies may also prove effective.
Prominent labeling of HFC-152a A/C systems is required with warning
such as ``CAUTION SYSTEM CONTAINS POTENTIALLY FLAMMABLE HFC-152a
REFRIGERANT--TO BE SERVICED ONLY BY QUALIFIED PERSONNEL''. Consistent
with SAE J639 Standard, this label should be mounted in the engine
compartment on a component that is not normally replaced and where it
can be easily seen. This label should include refrigerant
identification information and indicate the refrigerant is potentially
flammable. HFC-152a systems operate at pressures similar to those of
HFC-134a systems, with which technicians are familiar; therefore EPA
has determined that additional labeling to address high pressure is
unnecessary.
Original equipment manufacturers (OEMs) are required to keep
records of the tests they perform to ensure that MVAC systems are safe
and are designed with sufficient safety mitigation devices to ensure
that occupants are not exposed to levels of HFC-152a at or above 3.7%
for more than 15 seconds. Presently, no standard test procedure exists
to determine that concentrations of concern are not exceeded, but EPA
is working together with stakeholders and standards organizations to
develop these test standards. The Agency expects these standards to be
in place by the time that HFC-152a MVAC systems are deployed in U.S.
vehicles. Other use conditions already established in Appendix D to
Subpart G of 40 CFR Part 82 are applicable to all substitute
refrigerants in MVAC systems (e.g. unique fittings and labels).
VI. Other Use Conditions Applicable to Motor Vehicle Air Conditioning
Systems
On October 16, 1996, (61 FR 54029), EPA promulgated a final rule
that prospectively applied certain conditions on the use of any
refrigerant used as a substitute for CFC-12 in motor vehicle air
conditioning systems (Appendix D of Subpart G of 40 CFR part 82). That
rule provided that EPA would list new refrigerant substitutes in future
notices of acceptability and all such refrigerants would be subject to
the use conditions stated in that rule. Therefore, the use of both
CO2 and HFC-152a in motor vehicle air conditioning systems
must follow the standard conditions imposed on refrigerant substitutes
previously listed by SNAP, including:
Use of unique fittings--identified by SAE standard J639
and subject to EPA approval;
Application of a detailed label identifying the
refrigerant in use and if it is potentially flammable or toxic \15\;
and
---------------------------------------------------------------------------
\15\ This proposal specifies the language to be used for this
label to warn technicians of the risks associated with HFC-152a and
CO\2\.
---------------------------------------------------------------------------
Installation of a high-pressure compressor cutoff switch
on systems equipped with pressure relief devices.
Because HFC-152a and CO2 retrofits of CFC-12 or HFC-134a
are prohibited by EPA, this document does not consider the additional
SNAP requirements for MVAC substitutes approved for use in retrofits.
VII. 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.
Burden means the total time, effort, or financial resources expended by
persons to generate, maintain, retain, or disclose or provide
information to or for a Federal agency. This includes the time needed
to review instructions; develop, acquire, install, and utilize
technology and systems for the purposes of collecting, validating, and
verifying information, processing and maintaining information, and
disclosing and providing information; adjust the existing ways to
comply with any previously applicable instructions and requirements;
train personnel to be able to respond to a collection of information;
search data sources; complete and review the collection of information;
and transmit or otherwise disclose the information.
This proposed rule is an Agency determination. It contains no new
requirements for reporting. The only new recordkeeping requirement
involves customary business practice. 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 (EPA
ICR No. 1596.05). This Information Collection Request (ICR) included
five types of respondent reporting and record keeping activities
pursuant to SNAP regulations: submission of a SNAP petition, filing a
SNAP/TSCA Addendum, notification for test marketing activity, record
keeping for substitutes acceptable subject to use restrictions, and
record-keeping for small volume uses. This proposed rule requires
minimal record-keeping of studies done to ensure that MVAC systems
using either HFC-152a or CO2 meet the requirements set forth
in this rule. Because it is customary business practice that automotive
systems manufacturers and automobile manufacturing companies conduct
and keep on file failure mode and Effect Analysis (FMEA) on any
potentially hazardous part or system, we believe this requirement will
not impose an additional paperwork burden.
An Agency may not conduct or sponsor, and a person is not required
to respond to, a collection of information unless it displays a
currently valid OMB control number. The OMB control numbers for EPA's
regulations are listed in 40 CFR Part 9 and 48 CFR Chapter 15.
[[Page 55147]]
Copies of the SNAP ICR document(s) may be obtained from Susan Auby,
by mail at the Office of Environmental Information, Office of
Information Collection, Collection Strategies Division; U.S.
Environmental Protection Agency (2822T); 1200 Pennsylvania Ave., NW.,
Washington, DC 20460, by e-mail at [email protected], or by calling
(202) 566-1672.
C. Regulatory Flexibility Act (RFA)
The 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
this 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; (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 this proposed rule on
small entities, we certify that this action will not have a significant
economic impact on a substantial number of small entities. The
requirements of this proposed rule impact car manufacturers and car air
conditioning system manufacturers only. These businesses do not qualify
as small entities. The change in CO2 acceptability to
include use conditions and the imposition of use conditions for HFC-
152a does not impact the small businesses. The change does not impact
car manufacturers because production-quality CO2 and HFC-
152a MVAC systems are not manufactured yet. Consequently, no change in
business practice is required by this proposed rule and will not impose
any requirements on small entities.
We continue to be interested in the potential impacts of the
proposed rule on small entities and welcome comments on issues related
to such impacts.
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. This proposed rule does not affect
State, local, or tribal governments. The enforceable requirements of
this proposed rule related to integrating risk mitigation devices and
documenting the safety of substitute refrigerant MVAC systems affect
only a small number of manufacturers of car air conditioning systems
and car manufacturers. This proposal provides additional technical
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, this 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. The change in acceptability of CO2
does not impact the private sector because manufacturers are not
producing systems under the current acceptability regulation. This
proposed rule does not mandate a switch to these substitutes;
consequently, there is no direct economic impact on entities from this
rulemaking.
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 proposal 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'' (65 FR 67249, 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.'' ``Policies that have tribal
implications'' is defined in the Executive Order to include regulations
that have ``substantial direct effects on one or more Indian tribes, on
the relationship between the Federal government and the Indian tribes,
or on the distribution of power and responsibilities between the
Federal government and Indian tribes.''
[[Page 55148]]
This proposed rule does not have tribal implications. It will not
have substantial direct effects on tribal governments, on the
relationship between the Federal government and Indian tribes, or on
the distribution of power and responsibilities between the Federal
government and Indian tribes, as specified in Executive Order 13175.
This proposed rule 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 proposed rule.
G. Executive Order 13045: Protection of Children From Environmental
Health and Safety Risks
Executive Order 13045: ``Protection of Children from Environmental
Health Risks and Safety Risks'' (62 FR 19885, April 23, 1997) applies
to any rule that: (1) Is determined to be ``economically significant''
as defined under Executive Order 12866, and (2) concerns an
environmental health or safety risk that EPA has reason to believe may
have a disproportionate effect on children. If the regulatory action
meets both criteria, the Agency must evaluate the environmental health
or safety effects of the planned rule on children, and explain why the
planned regulation is preferable to other potentially effective and
reasonably feasible alternatives considered by the Agency.
This proposed rule is not subject to the Executive Order because it
is not economically significant as defined in Executive Order 12866,
and because the Agency does not have reason to believe the
environmental health or safety risks addressed by this action present a
disproportionate risk to children. There are no experimental or
anecdotal data to indicate that children are more sensitive than adults
to the adverse effects of increased CO2 environments.\16\
The exposure limits and acceptability listings in this proposed rule
apply to car occupants, and in particular car drivers and service
technicians. These are areas where we expect adults are more likely to
be present than children, and thus, the agents do not put children at
risk disproportionately.
---------------------------------------------------------------------------
\16\ Risk Analysis for Alternative Refrigerant in Motor Vehicle
Air Conditioning (EPA, 2005).
---------------------------------------------------------------------------
The public is invited to submit or identify peer-reviewed studies
and data, of which the agency may not be aware, that assesses the
potential effects of these alternatives on children.
H. Executive Order 13211: Actions That Significantly Affect Energy
Supply, Distribution, or Use
This proposed rule is not a ``significant energy action'' as
defined in Executive Order 13211, ``Actions Concerning Regulations That
Significantly Affect Energy Supply, Distribution, or Use'' (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 would
impact manufacturing and repair of alternative MVAC systems.
Preliminary information indicates that these new systems may be more
energy efficient than currently available systems in some climates.
Therefore, we conclude that this rule is not likely to have any adverse
effects 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 No. 104-113, Section 12(d) (15
U.S.C. 272 note) directs EPA to use voluntary consensus standards in
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. The NTTAA directs EPA
to provide Congress, through OMB, explanations when the Agency decides
not to use available and applicable voluntary consensus standards. This
proposed rule regulates the safety and deployment of new substitutes
for MVAC systems. EPA is referencing the Society of Automotive
Engineers (SAE) standard J639, which is currently being revised to
include requirements for safety and reliability for HFC-152a and
CO2 systems.
VIII. References
The documents below are referenced in the preamble. All documents
are located in the Air Docket at the address listed in section I.B.1 at
the beginning of this document. Unless specified otherwise, all
documents are available in Docket ID No. EPA-HQ-OAR-2004-0488 at
www.regulations.gov.
Atkinson, W. 2002. Consumer Use of A/C Systems. SAE Automotive
Alternate Refrigerant Systems Symposium 2002. Phoenix, Arizona.
Gellhorn, E. 1936. The Effect of O2-Lack, Variations in
the Carbon Dioxide-Content of the Inspired Air, and Hyperpnea on
Visual Intensity Discrimination. American Journal of Physiology.
115: 679-684.
Hunter D. 1975. The diseases of occupations. 5th ed. London: Hodder
and Stoughton, p. 618.
Jetter, J., R. Forte, and R. Rubenstein. 2001. Fault Tree Analysis
for Exposure to Refrigerants Used for Automotive Air Conditioning in
the United States. Risk Analysis. 21(1):157-170.
Lambertsen, C.J. 1971. Therapeutic Gases: Oxygen, Carbon Dioxide,
and Helium. In Drill's Pharmacology in Medicine, ed. J.R. DiPalma,
1145-1179. New York, NY: McGraw-Hill.
Memo to Acting Administrator, Marianne L. Horinko. 2003. EPA's
Authority to Impose Mandatory Controls to Address Global Climate
Change under the Clean Air Act, from Robert E. Fabricant.
National Institute for Occupational Safety and Health. 1976.
Criteria for Document for Carbon Dioxide. NIOSH Publication No. 76-
194.
National Institute for Occupational Safety and Health. 2005. NIOSH
Pocket Guide to Chemical Hazards. NIOSH Publication No. 2005-151.
Occupational Safety and Health Administration. 1989. Carbon Dioxide,
Industrial Exposure and Control Technologies for OSHA Regulated
Hazardous Substances, Volume I of II, Substance A-I. Occupational
Safety and Health Administration. Washington, DC: U.S. Department of
Labor. March.
Patterson, J.L., H. Heyman, L.L. Battery, R.W. Ferguson. 1955.
Threshold of response of the cerebral vessels of man to increases in
blood carbon dioxide. Journal of Clinical Investigations. 34:1857-
1864.
Rebinger, C. 2005. Safety Concept Proposal for R744 A/C Systems in
Passenger Cars--Update 2005. VDA Alternate Refrigerant Winter
Meeting 2005. Saalfelden, Austria.
RISA Sicherheitsanalysen. 2002. Safety-Study for a Prototypical
Mobile R744 A/C System. VDA Alternate Refrigerant Winter Meeting
2002. Saalfelden, Austria
Sayers, J.A., R.E.A. Smith, R.L Holland, W.R. Keatinge. 1987.
Effects of Carbon Dioxide on Mental Performance. Journal of Applied
Physiology. 63(1):25-30.
Schneider, E.C., E. Truesdale. 1922. The effects on circulation and
respiration of an increase in the carbon dioxide content of blood in
man. American Journal of Physiology. 63:155-175.
Schulte, J.H. 1964. Sealed environments in relation to health and
disease. Archives of Environmental Health. 8: 438-452.
Society of Automotive Engineers (SAE). 2005. Surface Vehicle
Standard J639. Safety Standards for Motor Vehicle Refrigerant Vapor
Compression Systems.
United States Environmental Protection Agency (EPA). 1994. SNAP
Technical Background Document: Risk Screen on the Use of Substitutes
for Class I Ozone-Depleting Substances: Refrigeration and Air
Conditioning.
United States Environmental Protection Agency (EPA). 2005. Risk
Analysis for Alternative Refrigerant in Motor Vehicle Air
Conditioning.
Wilson, D.P., R. Richard. 2002. Determination of Refrigerant Lower
[[Page 55149]]
Flammability Limits in Compliance with Proposed Addendum p to
Standard 34. HI-02-7-2 (RP-1073).
Wong, K.L. 1992. Carbon Dioxide. Internal Report, Johnson Space
Center Toxicology Group. National Aeronautics and Space
Administration: Houston, TX. 1987.
List of Subjects in 40 CFR Part 82
Environmental protection, Administrative practice and procedure,
Air pollution control, Reporting and recordkeeping requirements.
Dated: September 14, 2006.
Stephen L. Johnson,
Administrator.
For the reasons set out in the preamble, 40 CFR part 82 is proposed
to be amended as follows:
PART 82--PROTECTION OF STRATOSPHERIC OZONE
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
2. The first table in Subpart G to Appendix B of part 82 is amended
by adding 2 new entries to the end of the table to read as follows:
Appendix B to Subpart G of Part 82--Substitutes Subject to Use
Restrictions and Unacceptable Substitutes
Refrigerants--Acceptable Subject to Use Conditions
----------------------------------------------------------------------------------------------------------------
Application Substitute Decision Conditions Comments
----------------------------------------------------------------------------------------------------------------
* * * * * * *
CFC-12 Automobile Motor Carbon Dioxide (CO2) Acceptable subject to Engineering Additional
Vehicle Air Conditioning as a substitute for use conditions. strategies and/ training for
(New equipment only). CFC-12. or devices service
shall be technicians
incorporated recommended.
into the system Manufacturers
such that should conduct
foreseeable and keep on
leaks into the file Failure
free space \1\ Mode and
of the Effect
passenger Analysis
compartment do (FEMA) on the
not result in MVAC as stated
concentrations in SAE J1739.
greater than In designing
the CO2 short- safety
term exposure mitigation
limit (STEL) of strategies and/
3% v/v for 15 or devices,
minutes. manufacturers
Manufacturers should factor
must adhere to in background
all the safety CO2
requirements concentrations
listed in the potentially
Society of contributed
Automotive from normal
Engineers (SAE) respiration by
Standard J639, the maximum
including number of
unique fittings vehicle
and a high occupants.
pressure system
warning label.
CFC-12 Automobile Motor HFC-152a as a Acceptable subject to Engineering Additional
Vehicle Air Conditioning substitute for CFC-12. use conditions. strategies and/ training for
(New equipment only). or devices service
shall be technicians
incorporated recommended.
into the system Manufacturers
such that should conduct
foreseeable and keep on
leaks into the file Failure
passenger Mode and
compartment do Effect
not result in Analysis
HFC-152a (FMEA) on the
concentrations MVAC as stated
of 3.7% v/v or in SAE J1739.
above in any
part of the
free space \2\
inside the
passenger
compartment for
more than 15
seconds.
Manufacturers
must adhere to
all the safety
requirements
listed in the
Society of
Automotive
Engineers (SAE)
Standard J639,
including
unique fittings
and a flammable
refrigerant
warning label.
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\1\ Free space is defined as the space inside the passenger compartment excluding the space enclosed by the
ducting in the HVAC module.
\2\ Free space is defined as the space inside the passenger compartment excluding the space enclosed by the
ducting in the HVAC module.
[FR Doc. 06-7967 Filed 9-20-06; 8:45 am]
BILLING CODE 6560-50-P