WAC 296-155-47501
Definitions applicable to this part. (1) Equivalent means alternative designs, materials, or
methods that the employer can demonstrate will provide an
equal or greater degree of safety for employees than the
method or item specified in the standard.
(2) Failure means load refusal, breakage, or separation
of component parts. Load refusal is the point where the
structural members lose their ability to carry the loads.
(3) Handrail means a rail used to provide employees with
a handhold for support.
(4) Lower levels means those areas to which an employee
can fall from a stairway or ladder. Such areas include ground
levels, floors, roofs, ramps, runways, excavations, pits,
tanks, material, water, equipment, and similar surfaces. It
does not include the surface from which the employee falls.
(5) Nosing means that portion of a tread projecting
beyond the face of the riser immediately below.
(6) Platform means a walking/working surface for persons,
elevated above the surrounding floor or ground.
(7) Point of access means all areas used by employees for
work-related passage from one area or level to another. Such
open areas include doorways, passageways, stairway openings,
studded walls, and various other permanent or temporary
openings used for such travel.
(8) Riser height means the vertical distance from the top
of a tread to the top of the next higher tread or
platform/landing or the distance from the top of a
platform/landing to the top of the next higher tread or
platform/landing.
(9) Spiral stairway means a series of steps attached to a
vertical pole and progressing upward in a winding fashion
within a cylindrical space.
(10) Stairrail system means a vertical barrier erected
along the unprotected sides and edges of a stairway to prevent
employees from falling to lower levels. The top surface of a
stairrail system may also be a "handrail."
(11) Tread depth means the horizontal distance from front
to back of a tread (excluding nosing, if any).
(12) Unprotected sides and edges means any side or edge
(except at entrances to points of access) of a stairway where
there is no stairrail system or wall 36 inches (.9 m) or more
in height, and any side or edge (except at entrances to points
of access) of a stairway landing, or ladder platform where
there is no wall or guardrail system 39 inches (1 m) or more
in height.
[Statutory Authority: RCW 49.17.010, 49.17.040, 49.17.050,
49.17.060. 06-16-020, § 296-155-47501, filed 7/24/06,
effective 12/1/06; 05-20-068, § 296-155-47501, filed 10/4/05,
effective 1/1/06. Statutory Authority: Chapter 49.17 RCW. 91-24-017 (Order 91-07), § 296-155-47501, filed 11/22/91,
effective 12/24/91.]