[Title 29 CFR 1910.24]
[Code of Federal Regulations (annual edition) - July 1, 2002 Edition]
[Title 29 - LABOR]
[Subtitle B - Regulations Relating to Labor (Continued)]
[Chapter Xvii - OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT]
[Part 1910 - OCCUPATIONAL SAFETY AND HEALTH STANDARDS]
[Subpart D - Walking-Working Surfaces]
[Sec. 1910.24 - Fixed industrial stairs.]
[From the U.S. Government Printing Office]


29LABOR52002-07-012002-07-01false1910.24Sec. 1910.24LABORRegulations Relating to Labor (Continued)OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENTOCCUPATIONAL SAFETY AND HEALTH STANDARDSWalking-Working Surfaces
Sec. 1910.24  Fixed industrial stairs.

    (a) Application of requirements. This section contains 
specifications for the safe design and construction of fixed general 
industrial stairs. This classification includes interior and exterior 
stairs around machinery, tanks, and other equipment, and stairs leading 
to or from floors, platforms, or pits. This section does not apply to 
stairs used for fire exit purposes, to construction operations to 
private residences, or to articulated stairs, such as may be installed 
on floating roof tanks or on dock facilities, the angle of which changes 
with the rise and fall of the base support.
    (b) Where fixed stairs are required. Fixed stairs shall be provided 
for access from one structure level to another where operations 
necessitate regular travel between levels, and for access to operating 
platforms at any equipment which requires attention routinely during 
operations. Fixed stairs shall also be provided where access to 
elevations is daily or at each shift for such purposes as gauging, 
inspection, regular maintenance, etc., where such work may expose 
employees to acids, caustics, gases, or other harmful substances, or for 
which purposes the carrying of tools or equipment by hand is normally 
required. (It is not the intent of this section to preclude the use of 
fixed ladders for access to elevated tanks, towers, and similar 
structures, overhead traveling cranes, etc., where the use of fixed 
ladders is common practice.) Spiral stairways shall not be permitted 
except for special limited usage and secondary access situations where 
it is not practical to provide a conventional stairway. Winding 
stairways may be installed on tanks and similar round structures where 
the diameter of the structure is not less than five (5) feet.
    (c) Stair strength. Fixed stairways shall be designed and 
constructed to carry a load of five times the normal live load 
anticipated but never of less strength than to carry safely a moving 
concentrated load of 1,000 pounds.
    (d) Stair width. Fixed stairways shall have a minimum width of 22 
inches.
    (e) Angle of stairway rise. Fixed stairs shall be installed at 
angles to the horizontal of between 30 deg. and 50 deg.. Any uniform 
combination of rise/tread dimensions may be used that will result in a 
stairway at an angle to the horizontal within the permissible range. 
Table D-1 gives rise/tread dimensions which will produce a stairway 
within the permissible range, stating the angle to the horizontal 
produced by each combination. However, the rise/tread combinations are 
not limited to those given in Table D-1.

                                Table D-1
------------------------------------------------------------------------
                                                                  Tread
                 Angle to horizontal                  Rise (in   run (in
                                                       inches)   inches)
------------------------------------------------------------------------
30 deg.35[min]......................................    6\1/2\        11
32 deg.08[min]......................................    6\3/4\   10\3/4\
33 deg.41[min]......................................         7   10\1/2\
35 deg.16[min]......................................    7\1/4\   10\1/4\
36 deg.52[min]......................................    7\1/2\        10
38 deg.29[min]......................................    7\3/4\    9\3/4\
40 deg.08[min]......................................         8    9\1/2\
41 deg.44[min]......................................    8\1/4\    9\1/4\
43 deg.22[min]......................................    8\1/2\         9
45 deg.00[min]......................................    8\3/4\    8\3/4\
46 deg.38[min]......................................         9    8\1/2\
48 deg.16[min]......................................    9\1/4\    8\1/4\
49 deg.54[min]......................................    9\1/2\         8
------------------------------------------------------------------------

    (f) Stair treads. All treads shall be reasonably slip-resistant and 
the nosings shall be of nonslip finish. Welded bar grating treads 
without nosings are acceptable providing the leading edge can be readily 
identified by personnel descending the stairway and provided the tread 
is serrated or is of definite nonslip design. Rise height and tread 
width shall be uniform throughout any flight of stairs including any 
foundation structure used as one or more treads of the stairs.
    (g) Stairway platforms. Stairway platforms shall be no less than the 
width of a stairway and a minimum of 30 inches in length measured in the 
direction of travel.

[[Page 123]]

    (h) Railings and handrails. Standard railings shall be provided on 
the open sides of all exposed stairways and stair platforms. Handrails 
shall be provided on at least one side of closed stairways preferably on 
the right side descending. Stair railings and handrails shall be 
installed in accordance with the provisions of Sec. 1910.23.
    (i) Vertical clearance. Vertical clearance above any stair tread to 
an overhead obstruction shall be at least 7 feet measured from the 
leading edge of the tread.

[39 FR 23502, June 27, 1974, as amended at 43 FR 49744, Oct. 24, 1978; 
49 FR 5321, Feb. 10, 1984]