The standard does not clearly establish the safety responsibilities of an owner, A/E, or GC for the safety of a subcontractor’s employees. Indeed, except for a small portion of Subpart B (which applies only to federally funded projects) and one sentence in 1926.20, nowhere in 29 CFR 1926 are the terms owner, general contractor, and subcontractor even used. Instead, all references are to the duties of employers of employees potentially exposed to hazards. Thus, the only nationally required construction safety standards establish proactive safety management responsibilities for entities involved in a construction project only to the extent that they have employees on-site who may be exposed to hazards.