Are underground pits confined spaces?

Generally, OSHA’s confined space standard, 1910.146, covers pits because they are large enough to enter, have limited or restricted means of access/egress, and aren’t designed for continuous worker occupancy. Section 1910.146(c)(5)(ii)(B) says the opening shall be guarded by a railing, temporary cover, or other temporary barrier that will prevent an accidental fall through the opening and that will protect each employee working in the space from foreign objects entering the space.

OSHA says that the employer needs to prevent falls and prevent things from falling into the confined space and onto a worker while they are inside the pit. Normally, a safety net could be used for fall protection. But here, since a pit could be a confined space, OSHA requires the use of a barrier to prevent any accidental fall into the pit.

Also, the use of a safety net requires a lot of vertical clearance because, during a fall, the net flexes downward, and the worker can hit the ground if there’s not enough clearance. Depending on the hazards present and the pit’s configuration, other OSHA 1910 General Industry standards may be applicable depending on the situation.