Safety fencing is used for two general purposes. One is to protect workers from falling into excavations, openings, trenches, or holes. The second is for security purposes to keep unauthorized personnel out of restricted areas. The Occupational Safety and Health Administration maintains standards for both types of safety fencing.
Fencing that is designed to surround ground openings are treated similarly to handrails. Safety fencing must be four feet high, include a toe board, and be capable of supporting a 200 pound load on the top member of the fence.
Fencing designed for security purposes can be either used to keep a job site secure or to restrict access to dangerous equipment. In this case, fencing must be at least seven feet high and any gates must be secured with locks.
Barbed wire may be used in conjunction with security fencing. In this case, the fence may be only six feet high with three strands of barbed wire that extend the total height to seven feet.