Subcontractors are ascribed a high level of safety expertise because it is their employees who are most exposed to hazards on the jobsite, and paragraph 1926.21(b)(2) of the 2000 OSHA CFR requires them to train their employees on recognizing and avoiding hazards. GCs are ascribed a moderate level of safety expertise for three reasons. First, they usually have some employees continually on-site who may be exposed to hazards as part of their oversight function. Second, GC employees may potentially be in a position to recognize a hazard and prevent an accident, again associated with their oversight function. A third and practical reason is that GCs want to prevent all accidents because they often slow project progress.