Wash. Admin. Code § 296-24-73502
As used in Part J of this chapter, the following definitions apply:
Alternating tread-type stair. A type of stairway consisting of a series of treads that are usually 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.
Dockboard. A portable or fixed device that spans a gap or compensates for a difference in elevation between a loading platform and a transport vehicle. Dockboards include, but are not limited to, bridge plates, dock plates, and dock levelers.
Failure. A load refusal, breakage, or separation of component parts. A load refusal is the point at which the ultimate strength of a component or object is exceeded.
Grab bar. An individual horizontal or vertical handhold installed to provide access above the height of the ladder.
Guardrail system. A barrier erected along an unprotected or exposed side, edge, or other area of a walking-working surface to prevent employees from falling to a lower level. For dimension requirements (rail heights, etc.), see the unified fall protection rule (chapter 296-880 WAC).
Handrail. Means a rail used to provide employees with a handhold for support.
Lower level. A surface or area to which an employee could fall. Such surfaces or areas include, but are not limited to, ground levels, floors, roofs, ramps, runways, excavations, pits, tanks, materials, water, equipment, and similar surfaces and structures, or portions thereof.
Maximum intended load. The total load (weight and force) of all employees, equipment, vehicles, tools, materials, and other loads the employer reasonably anticipates to be applied to a walking-working surface at any one time.
Nose, nosing. That portion of a tread projecting beyond the face of the riser immediately below.
Open riser. The gap or space between treads of stairways that do not have upright or inclined members (risers).
Platform. A walking-working surface that is elevated above the surrounding area.
Qualified. Describes a person who, by possession of a recognized degree, certificate, or professional standing, or who by extensive knowledge, training, and experience has successfully demonstrated the ability to solve or resolve problems relating to the subject matter, the work, or the project.
Railing. A vertical barrier erected along exposed sides of stairways and platforms to prevent falls of persons. The top member of railing usually serves as a handrail.
Ramp. An inclined walking-working surface used to access another level.
Rise. The vertical distance from the top of a tread to the top of the next higher tread.
Riser. The upright (vertical) or inclined member of a stair that is located at the back of a stair tread or platform and connects close to the front edge of the next higher tread, platform, or landing.
Runway. An elevated walking-working surface, such as a catwalk, a foot walk along shafting, or an elevated walkway between buildings.
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 platform. An extended step or landing breaking a continuous run of stairs.
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.
Unprotected sides and edges. Mean any side or edge of a walking-working surface (except at entrances and other points of access) where there is no wall, guardrail system, or stair rail system to protect an employee from falling to a lower level. For requirements relating to unprotected sides and edges, see the unified fall protection rule (chapter 296-880 WAC).
Walking-working surface. Any surface, whether horizontal or vertical on which an employee walks, works, or gains access to a work area or workplace location. Walking-working surfaces include, but are not limited to, floors, the ground, roofs, ramps, bridges, runways, stairs, dockboards, formwork and concrete reinforcing steel.
Wash. Admin. Code § 296-24-73502