Confined Space Entry

A confined space entry is the work that puts a worker into the space not designed for continuous occupancy, with the limited entry and the limited egress that turn a small problem into a fatality — the tank, the vessel, the manhole, the silo, the pit. OSHA 29 CFR 1910.146 defines the permit-required confined space as the one with a serious hazard: the atmospheric, the engulfment, the entrapment, or the configuration that could trap or asphyxiate the entrant. The entry requires the atmospheric test for the oxygen, the LEL, and the toxic gases before the entrant goes in, the isolation and the lockout of the energy and the fluids that could move into the space, the written entry permit that authorises the entry, the attendant outside who watches the entrant, and the rescue plan that gets the worker out without a second casualty.

The confined-space fatality is the one that takes the rescuer with it, because the atmosphere that dropped the entrant drops the co-worker who climbs in to help, and the rescue without the plan and the equipment is the cascade the standard was written to stop. The non-entry rescue — the tripod, the winch, the retrieval line — is the method the standard prefers, because the entrant who can be pulled out does not need a rescuer in the space. The atmospheric test is not a one-time reading: the continuous monitor on the entrant, the periodic re-test, and the ventilation that holds the atmosphere are the controls that keep the entry safe over the time the work takes. NFPA 350 is the practice guide on top of the OSHA rule. See permit to work, LOTO, and LEL.