OSHA Occupational Safety and Health Administration
Equipment Access – industrial equipment access stairs, catwalks, and platforms are often simply referred to as OSHA Stairs. MSHA (Mine Safety and Health Administration) and IMC (International Mechanical Code) stairs also fit into this same category. OSHA stair standards are more extensive than the other two therefore all three would qualify as OSHA compliant stairs.
IBC International Building Code
Egress Stair Systems – defined as a continuous and unobstructed path of travel from any occupied portion of a building or structure to a public way. IBC code applies to these situations with some differences depending on occupancy types.
IRC International Residential Code
Less extensive to the IBC codes, the IRC codes are specific to only residential properties. This comprehensive code applies only to single-family houses, two-family houses, and buildings consisting of three or more town-house units. Buildings within the scope of IRC are limited to 3 stories above grade plane. Any larger or taller residential buildings fall under the IBC requirements.
Note: In many public area stairs any combination of ADA, NFPA, ANSI, and ASTM standards may apply. Each locality may have its own list of such requirements to be followed.
NON-STANDARD steep stairs, spiral stairs, and ladders
OSHA and IBC define different types of stairways and ladders that are not classified as standard stairs. Non-standard stairs are used only when the employer can demonstrate that it is not feasible to provide standard stairs. The final rule is based on specific case-by-case evaluations and demonstrations it is not possible to use standard stairs.
Fixed Ladder: A ladder with rails or individual rungs that is permanently attached to a structure, building, or equipment.
Ship Stair: A stair that is equipped with treads, stair rails, and open risers, and has a slope that is between 50 and 70 degrees from the horizontal.
Alternating Tread-Type Stair: A type of stair consisting of a series of treads that usually are attached to a center support in an alternating manner such that users typically do not have both feet on the same level while using stair.
Spiral Stair: A stairway having a closed circular form in its plan view with uniform section-shaped treads attached to minimum-diameter supporting column.
