1917 Subpart F
A fixed stairway is an interior or exterior stair that serves machinery, tanks, equipment, or provides access to floors, platforms, or pits; it does not include stairs intended only for fire egress, articulated stairs whose angle changes with the base support, or stairs that are an integral part of machinery. See the definition in 1917.120(a).
Fixed stairs installed after October 3, 1983 must be positioned between 30 degrees and 50 degrees to the horizontal. See the installation angle requirement in 1917.120(b)(1).
New fixed stairs must have uniform riser heights of 6 to 7.5 inches and tread depths of 12 ± 2 inches for each run. These dimensions are specified in 1917.120(b)(1).
The minimum stair width is 22 inches measured between vertical barriers (for example, between guardrails, walls, or other vertical edges). This width requirement appears in 1917.120(b)(1).
New fixed stair treads must be capable of a minimum uniform live load of 100 pounds per square foot and a minimum concentrated load of 300 pounds at the center of any tread span. See the strength requirements in 1917.120(b)(1).
Stair railings or handrails are required on fixed stairs that have four or more risers. The railing or handrail must comply with 1917.112(c)(1) as referenced in 1917.120(b)(3).
Railing height must be 33 inches, plus or minus 3 inches, measured from the tread surface at the riser face. See the railing height specification in 1917.120(b)(4).
Stair landings must be at least 20 inches (50.8 cm) deep. Where doors or gates open onto a stairway, a landing platform must be provided and the door swing must not reduce the effective standing area of the landing to less than 18 inches in depth. See the landing and door-swing rules in 1917.120(b)(2).
Stairs steeper than the 30°–50° range may be used in restricted areas when physical features require them; such steep stairs (50° to 75°) must be capable of a single concentrated load of 200 pounds at the tread centers. See the allowance and load requirement in 1917.120(b)(5) and 1917.120(b)(5)(i).
For restricted-area steep stairs (50°–75°), treads must be open and at least 4 inches deep and 18 inches wide, with a uniformly spaced vertical rise between treads of 6 to 9.5 inches. See 1917.120(b)(5)(ii).
Restricted-area steep stairs must have handrails meeting 1917.112(c)(1) on both sides, and those handrails must be at least 30 inches in height measured from the tread surface at the riser face. See 1917.120(b)(5)(iii).
Tread nosings must have straight leading edges (i.e., straight nosing, not curved or rounded projections). This nosing requirement is part of the dimensional and construction rules in 1917.120(b)(1).
Fixed stairways must be maintained in a safe condition and must not be obstructed. Employers are responsible for keeping stairs safe, clean, and free of materials or objects that block passage. See the maintenance requirement in 1917.120(b)(6).
No; stairs intended only for fire exit purposes are excluded from the definition of "fixed stairway" in 1917.120(a).
Handrails or stair railings required under 1917.120(b)(3) must comply with the technical provisions of 1917.112(c)(1), which address guardrail and handrail construction specifics (such as strength and configuration). Refer to 1917.112(c)(1) for the detailed rail/guard requirements.</p>
No; 1917.120(b)(1) requires uniform riser height and tread width throughout each run. Stairs must be consistent in a run to comply.
When stairs must be steeper than 50° because of physical constraints, employers may use stairs at 50°–75° only if they meet the special restricted-area criteria in 1917.120(b)(5), including the higher concentrated-load capacity (1917.120(b)(5)(i)), minimum open tread size and rise (1917.120(b)(5)(ii)), and handrails on both sides at not less than 30 inches high (1917.120(b)(5)(iii)).
Part 1917 generally applies to marine terminals, but some waterfront facilities that are designated waterfront facilities may be outside Part 1917’s scope; OSHA has explained applicability issues in its letter regarding waterfront facilities at https://www.osha.gov/laws-regs/standardinterpretations/2017-05-31. Always confirm whether your specific waterfront location falls within Part 1917’s scope before relying on Part 1917 alone.
No; when a door or gate opens onto a stairway landing, the door swing must not reduce the effective standing area of the landing to less than 18 inches in depth. The landing itself must be at least 20 inches deep as required by 1917.120(b)(2).
"Open treads" means the stair treads are not fully solid or closed at the back (there is an open space between treads), and for restricted steep stairs the standard requires open treads at least 4 inches deep and 18 inches wide to help ensure foot placement and reduce trip hazards. See the requirement for open treads and dimensions in 1917.120(b)(5)(ii).
While 1917.120(b)(3) requires handrails only for stairs with four or more risers, it is good safety practice to provide handrails on shorter flights where worker safety could be improved; employers should apply prudent hazard control measures and may consult 1917.112(c)(1) for handrail construction guidance.
Railing or handrail height is measured from the tread surface at the riser face; regular fixed-stair railing height must be 33 ± 3 inches per 1917.120(b)(4), and restricted steep-stair handrails must be not less than 30 inches high as stated in 1917.120(b)(5)(iii).
No specific inspection frequency is stated in the text, but 1917.120(b)(6) requires that fixed stairways be maintained in safe condition and not be obstructed, which means employers must inspect and repair stairs as necessary to keep them safe under normal maintenance practices.
No; stairs that are an integral part of machinery and articulated stairs (whose angle changes with the rise and fall of the base support) are excluded from the definition of "fixed stairway" under 1917.120(a), so the dimensional rules of 1917.120 do not apply to them.