OSHA’s requirements for fixed industrial stairs are set out in 29 CFR 1910.25, with related fall-protection rules in 1910.28 and 1910.29 and inspection and training duties in 1910.22 and 1910.30. Together, these rules govern the angle, width, riser height, tread depth, load capacity, handrails, guardrails, landings, and upkeep of any permanently installed stairway workers use to move between levels. Getting a detail wrong is one of the more common ways employers pick up citations, and fixing a noncompliant stair after the fact almost always costs more than building it right.
What Stairs the Rule Covers
If a stairway gives workers routine access from one walking-working surface to another during operations, it falls under 1910.25. That includes interior and exterior stairs connecting floors, platforms, pits, and equipment areas, and it covers standard, spiral, ship, and alternating tread-type stairs.1Occupational Safety and Health Administration. 1910.25 – Stairways
Several categories sit outside the standard. It does not apply to articulated stairs (the kind on floating roof tanks that change pitch as the attachment point shifts), stairs built into machines or equipment, stairs on scaffolds, or stairs on self-propelled motorized equipment.1Occupational Safety and Health Administration. 1910.25 – Stairways Spiral, ship, and alternating tread stairs are permitted only when the employer can demonstrate that standard stairs are not feasible for the location.
Dimensions Every Standard Stairway Must Meet
The geometry of a standard stairway is tightly regulated. Here are the core dimensional requirements under 1910.25:1Occupational Safety and Health Administration. 1910.25 – Stairways
- Angle between 30 and 50 degrees from the horizontal.
- Minimum clear width of 22 inches, measured between vertical barriers such as guardrails or walls.
- Maximum riser height of 9.5 inches.
- Minimum tread depth of 9.5 inches.
- Uniform riser heights and tread depths between landings throughout the entire flight.
- Vertical clearance of at least 6 feet, 8 inches above any tread to any overhead obstruction, measured from the leading edge of the tread.
The uniformity requirement is not decorative. OSHA treats inconsistent riser heights or tread depths within a flight as a serious compliance issue.
Load Capacity and Slip Resistance
Every fixed industrial stairway must be strong enough to carry five times the normal expected live load, and that capacity can never drop below a concentrated load of 1,000 pounds applied at any single point.1Occupational Safety and Health Administration. 1910.25 – Stairways Metal, concrete, or wood all work as long as the finished structure meets that threshold.
Treads, nosings, and landing surfaces must all be reasonably slip-resistant.1Occupational Safety and Health Administration. 1910.25 – Stairways OSHA does not specify a particular material or coating, but slip resistance is an ongoing obligation, not a one-time design choice. Treads worn smooth, coated in oil, or left wet create exactly the kind of hazard inspectors look for.
Handrails and Guardrails
Handrails and guardrails do different jobs, and both may be needed on the same stairway.
A handrail is what you grab for stability while walking. It is required on every flight with at least four risers, and its top must sit between 30 and 38 inches above the leading edge of the stair tread.2eCFR. 29 CFR 1910.29 – Fall Protection Systems and Falling Object Protection – Criteria and Practices Ship stairs and alternating tread-type stairs must have handrails on both sides regardless of how many risers they have.
Guardrails prevent people from falling off exposed edges of stairways and landings. They are required on every unprotected side of a stairway landing 4 feet or more above a lower level. The top edge must be 42 inches above the walking surface, plus or minus 3 inches.2eCFR. 29 CFR 1910.29 – Fall Protection Systems and Falling Object Protection – Criteria and Practices
The gap between the top rail and the walking surface cannot be left open. Acceptable fill options include a midrail set halfway between the top rail and the surface, a mesh screen, vertical balusters, or solid panels. When balusters or equivalent intermediate members are used, openings between them cannot exceed 19 inches.2eCFR. 29 CFR 1910.29 – Fall Protection Systems and Falling Object Protection – Criteria and Practices
Landings and Platforms
Every landing or platform connected to a stairway must be at least as wide as the stairway itself and at least 30 inches deep in the direction of travel.1Occupational Safety and Health Administration. 1910.25 – Stairways That depth gives workers room to stop or turn between flights without crowding the edge.
Doors and gates that open directly onto a landing are a special case. For platforms installed on or after January 17, 2017, a door swing cannot reduce the effective usable depth below 22 inches.1Occupational Safety and Health Administration. 1910.25 – Stairways Landing surfaces must be slip-resistant, just like the treads.
Rules for Spiral, Ship, and Alternating Tread Stairs
When a standard stairway will not fit the available space, three alternatives are allowed, each with its own dimensions.
Spiral Stairs
Minimum clear width of 26 inches, maximum riser height of 9.5 inches, and minimum tread depth of 7.5 inches measured 12 inches from the narrower edge. Tread sizes must be uniform throughout. Minimum headroom is 6 feet, 6 inches.3eCFR. 29 CFR 1910.25 – Stairways
Ship Stairs
Installed at an angle between 50 and 70 degrees, with open risers. Vertical rise between tread surfaces of 6.5 to 12 inches, minimum tread depth of 4 inches, and minimum tread width of 18 inches.3eCFR. 29 CFR 1910.25 – Stairways Handrails required on both sides.
Alternating Tread-Type Stairs
Slope of 50 to 70 degrees, minimum tread depth of 8.5 inches, and minimum tread width of 7 inches at the nosing. If the tread depth is under 9.5 inches, open risers are required. Distance between handrails must be 17 to 24 inches, and employers must follow the manufacturer’s installation instructions.1Occupational Safety and Health Administration. 1910.25 – Stairways
Keeping Stairs Compliant After Installation
Building to code is only half the job. Under 29 CFR 1910.22, employers must inspect all walking-working surfaces, stairways included, on a regular basis and whenever workplace conditions warrant an additional check.4Occupational Safety and Health Administration. 1910.22 – General Requirements OSHA does not set a specific inspection schedule. Employers set their own frequency, but once set, they must follow it.
When an inspection finds a hazardous condition, the stairway must be corrected before any employee uses it again. If the repair cannot happen immediately, the area must be guarded to keep workers off it. Any repair affecting structural integrity must be performed or supervised by a qualified person, meaning someone with the recognized education, certification, or extensive experience to do the work competently.4Occupational Safety and Health Administration. 1910.22 – General Requirements Written inspection records are not explicitly required, but without them, proving that inspections happened at the stated frequency is difficult during an investigation.
Training is a separate obligation. Under 29 CFR 1910.30, employers must train every employee who uses personal fall protection systems before that worker is exposed to a fall hazard. The training must be delivered by a qualified person and must cover the nature of fall hazards in the work area, how to recognize them, and procedures for minimizing them. Employees must also learn correct use, installation, inspection, and maintenance of their fall protection equipment.5Occupational Safety and Health Administration. 1910.30 – Training Requirements Retraining is required when workplace changes make earlier training obsolete, when equipment changes, or when a worker shows they no longer understand or can safely use the equipment. All training must be delivered in a manner the employee can understand.
What Violations Cost
OSHA adjusts civil penalties for inflation each year. Under the adjustment effective January 15, 2025, a serious violation of stairway standards carries a maximum fine of $16,550 per violation. Other-than-serious violations carry the same maximum. Willful or repeated violations rise to a maximum of $165,514 per violation.6Occupational Safety and Health Administration. 2025 Annual Adjustments to OSHA Civil Penalties
Each individual deficiency can be a separate violation. A stairway missing a guardrail, with inconsistent riser heights, and no handrail could generate three citations from a single inspection, before any abatement costs to bring the stairway into compliance.