Back when OSHA was writing their Permit-Required Confined Space standard (1910.146) their review of accident data indicated that most confined space deaths and injuries were caused by atmospheric hazards. And yet, still today, we see entrant, attendants, and entry supervisors; and even safety personnel, not understanding the atmospheric hazards associated with PRCSs. I hope to shed some light on these hazards and the rationale OSHA used when writing the standard with regards to the hazards found in PRCSs.
