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Confined Spaces Monitoring Requirements (1926.1204)


Entry employers must evaluate permit spaces:

  • Before changes to natural ventilation are made and before entry is authorized
  • If isolation is demonstrated to be infeasible (e.g., the space is too large) - 1926.1204 (e)(1)
    • Pre-entry testing is required, to the extent feasible
    • Continuous monitoring of working areas is required (periodic monitoring is allowed if continuous monitors are not commercially available)
    • Provide an early warning system for non-engulfment hazards that allows sufficient time for safe exit
  • Continuously monitor the space (or use period monitoring of sufficient frequency to assume safety throughout entry) - 1926.1204 (e)(2)
  • Test for hazards in this order: oxygen, combustible gases and vapors, then toxic gases and vapors - 1926.1204 (e)(3)
  • Provide entrants and their representatives an opportunity to observe monitoring - 1926.1204 (e)(4)
  • Reevaluate the space at the request of any entrant or their representative (in their presence) - 1926.1204 (e)(5)
  • Immediately provide entrant and their representatives with any test results - 1926.1204(e)(6)

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