• Key definitions for stairways are found in this section.

Alternating tread-type stair: A type of stairway consisting of a series of treads that usually are attached to a center support in an alternating manner such that an employee typically does not have both feet on the same level while using the stairway.

Handrail: A rail used to provide employees with a handhold for support.

Open riser: The gap or space between treads of stairways that do not have upright or inclined members (risers).

Ship stair (ship ladder): A stairway that is equipped with treads, stair rails, and open risers, and has a slope that is between 50 and 70 degrees from the horizontal.

Spiral stairs: A series of treads attached to a vertical pole in a winding fashion, usually within a cylindrical space.

Stair rail or stair rail system: A barrier erected along the exposed or open side of stairways to prevent employees from falling to a lower level.

Stairway (Stairs): Risers and treads that connect one level with another, and includes any landings and platforms in between those levels. Stairways include standard, spiral, alternating tread-type, and ship stairs.

Standard stairs: A fixed or permanently installed stairway. Ship, spiral, and alternating tread-type stairs are not considered standard stairs.

Tread: A horizontal member of a stair or stairway, but does not include landings or platforms.