Washington is a “state plan” state; that is, it has its own federally approved occupational safety and health regulatory program that governs both the private (private businesses) and public (state and local governments) sector employers and certain self-employed persons. The Washington Industrial Safety and Health Act (WISHA) mirrors federal rules, except that the state has adopted requirements that are stricter than the federal fall protection rules.
The Washington Department of Labor and Industries' (DLI) Division of Occupational Safety and Health (DOSH) administers and enforces fall protection requirements in private and public sector workplaces.
REGARDLESS OF HEIGHT
Washington Administrative Code (WAC) 296-155-24607
Working above or adjacent to dangerous equipment. Regardless of height, open-sided floors, walkways, platforms, or runways above or adjacent to dangerous equipment, such as dip tanks and material-handling equipment, and similar hazards must be guarded with a standard guardrail system.
Floor holes and floor openings. Floor holes and floor openings into which persons can accidently walk must be guarded by either a standard railing with standard toeboards on all exposed sides or a cover of standard strength and construction that is marked and secure against displacement. While the cover is not in place, the opening or hole must be protected by a standard railing.
Impalement hazards such as exposed rebar or wood stakes. Regardless of height, employees must be protected from falling into or onto impalement hazards, such as reinforcing steel (rebar) or exposed steel or wood stakes used to set forms. TRIGGER HEIGHT 4 FEET (FT) OR MORE
Fall protection ...