SYSTEM DESIGN
1910.25(c)(5)
Exception to paragraphs (c)(2) and (3) of this section. The requirements of paragraphs (c)(2)
and (3) do not apply to standard stairs installed prior to January 17, 2017. OSHA will deem
those stairs in compliance if they meet the dimension requirements specified in Table D-1 of
this section or they use a combination that achieves the angle requirements of paragraph (c)
(1) of this section.
Table D-1 Stairway Rise and Tread Dimensions
Angle to horizontal mm Rise (in inches) mm Tread run (in inches) mm
30 deg. 35’ 10668mm 6-1/2 165mm 11 279mm
32 deg. 08’ 2438mm 6-3/4 171mm 10-3/4 273mm
33 deg. 41’ 12497mm 7 178mm 10-1/2 267mm
35 deg. 16’ 4877mm 7-1/4 184mm 10-1/4 260mm
36 deg. 52’ 15850mm 7-1/2 191mm 10 254mm
38 deg. 29’ 8839mm 7-3/4 197mm 9-3/4 248mm
40 deg. 08’ 2438mm 8 203mm 9-1/2 241mm
41 deg. 44’ 13411mm 8-1/4 210mm 9-1/4 235mm
43 deg. 22’ 6706mm 8-1/2 216mm 9 229mm
45 deg. 00’ 0mm 8-3/4 222mm 8-3/4 222mm
46 deg. 38’ 11582mm 9 229mm 8-1/2 216mm
48 deg. 16’ 4877mm 9-1/4 235mm 8-1/4 210mm
49 deg. 54’ 16459mm 9-1/2 241mm 8 203mm
1910.28(b)(11)(ii)
Each flight of stairs having at least 3 treads and at least 4 risers is equipped with stair rail
systems and handrails as follows:
Table D-2 Stairway Handrail Requirements
1910.144(a)(3)
Yellow. Yellow shall be the basic color for designating caution and for marking physical hazards
such as: Striking against, stumbling, falling, tripping, and “caught in between.”
1926.451(f)(16)
Platforms shall not deflect more than 1/60 of the span when loaded.
1910.23(b)(1)
Ladder rungs, steps, and cleats are parallel, level, and uniformly spaced when the ladder is
in position for use;
1910.23(b)(2)
Ladder rungs, steps, and cleats are spaced not less than 10 inches (25 cm) and not more
than 14 inches (36 cm) apart, as measured between the centerlines of the rungs, cleats, and
steps, except that:
1910.23(b)(4)
Ladder rungs, steps, and cleats have a minimum clear width of 11.5 inches (29 cm) on portable
ladders and 16 inches (41 cm) (measured before installation of ladder safety systems)
for fixed ladders
1910.23(d)(1)
Fixed ladders are capable of supporting their maximum intended load;
1910.23(d)(2)
The minimum perpendicular distance from the centerline of the steps or rungs, or grab bars,
or both, to the nearest permanent object in back of the ladder is 7 inches (18 cm)
1910.23(d)(5)
For through ladders, the steps or rungs are omitted from the extensions, and the side rails
are flared to provide not less than 24 inches (61cm) and not more than 30 inches (76 cm) of
clearance.
1910.23(d)(12)
The step-across distance from the centerline of the rungs or steps is:
1910.23(d)(12)(i)
For through ladders, not less than 7 inches (18 cm) and not more than 12 inches (30 cm) to
the nearest edge of the structure, building, or equipment accessed from the ladders;
Stair width Enclosed One open side Two open sides With earth built up on
both sides
Less than
44 inches (1.1 m) At least one handrail
One stair rail system
with handrail on open
side.
One stair rail system
with handrail on open
side.
One stair rail system
with handrail on open
side.
44 inches (1.1 m)
to 88 inches (2.2 m)
One handrail on
each enclosed side
One Stair rail system
with handrail on open
side and one handrail
on enclosed side.
One Stair rail system
with handrail on open
side and one handrail
on enclosed side.
One Stair rail system
with handrail on open
side and one handrail
on enclosed side.
Greater than
88 inches (2.2 m)
One handrail on
each enclosed side
and one intermediate
handrail located
in the middle of
the stair
One stair rail system
with handrail on open
side, one handrail on
enclosed side, and one
intermediate handrail
located in the middle of
the stair.
One stair rail system
with handrail on open
side, one handrail on
enclosed side, and one
intermediate handrail
located in the middle of
the stair.
One stair rail system
with handrail on open
side, one handrail on
enclosed side, and one
intermediate handrail
located in the middle of
the stair.
Exterior stairs less
than
4.4 inches (1.1 m)
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