This article covers the new Subpart D stairways (29 CFR 1910.25 a – c) standards and the exception. Subpart D 29 CFR 1910.25 d – f were covered in a previous Safety Spotlight article.
1910.25 (a) Application – This section covers all stairways (including standard, spiral (d), ship (e) and alternating tread-type stairs (f)). Except for stairs serving floating roof tanks, stairs on scaffolds, stairs designed into machines or equipment, and stairs on self-propelled motorized equipment.
1910.25 (b) General Requirements – The employer must ensure:
(1) Handrails, stair rail systems and guardrail systems are provided in accordance with 1910.28.
(2) Vertical clearance above any stair tread to any overhead obstruction is at least 6 feet, 8 inches, as measured from the leading edge of the tread.
(3) Stairs have uniform riser heights and tread depths between landings;
(4) Stairway landings and platforms are at least the width of the stair and at least 30 inches in depth, as measured in the direction of travel;
(5) When a door or a gate opens directly on a stairway, a platform is provided, and the swing of the door or gate does not reduce the platform’s effective usable depth to:
(i) less than 20 inches for platforms installed before January 17, 2017; and
(ii) less than 22 inches for platforms installed on or after January 17, 2017
Angle to horizontal | Rise (in inches) | Tread run (in inches) |
30 deg. 35′ | 6 1/2 | 11 |
32 deg. 08′ | 6 3/4 | 10 3/4 |
33 deg. 41′ | 7 | 10 1/2 |
35 deg. 16′ | 7 1/4 | 10 1/4 |
36 deg. 52′ | 7 1/2 | 10 |
38 deg. 29′ | 7 3/4 | 9 3/4 |
40 deg. 08′ | 8 | 9 1/2 |
41 deg. 44′ | 8 1/4 | 9 1/4 |
43 deg. 22′ | 8 1/2 | 9 |
45 deg. 00′ | 8 3/4 | 8 3/4 |
46 deg. 38′ | 9 | 8 1/2 |
48 deg. 16′ | 9 1/4 | 8 1/4 |
49 deg. 54′ | 9 1/2 | 8 |