Many industrial facilities contain spaces that restrict the activities of employees working inside them. These permit required confined spaces have limited or restricted means for entry or exit. They are not designed for regular human occupancy. Confined spaces generally include manholes, pipelines, pits, process vessels, silos, storage bins, tanks, and vaults. Permit-required confined space entry especially includes space where a potentially hazardous atmosphere, loose materials, or exposed wires can asphyxiate, electrocute, engulf, or trap a worker.
Employees who enter confined spaces, entrants, are required to receive OSHA confined space safety training. This confined space entry training includes the attendant support team. OSHA 29 CFR 1910.146 defines training requirements.