Self-Contained Breathing Apparatus (SCBAs)

Are used for entry into or escape from environments considered to be IDLH. They contain their own breathing air supply and can be either open circuit or closed circuit.

  • Used for entry into or escape from environments considered to be IDLH
  • Two types: Open-Circuit and Closed-Circuit
  • Open-Circuit SCBAs
    – User carries pressurized cylinder on back to supply breathing air – Supplies breathing air for 30-90 minutes
    – Exhausts exhaled air instead of recirculating it
    – Can be either continuous-flow (escape-only), demand, or pressure-demand configurations
  • Closed-Circuit SCBAs
    – Approved for both entry and escape, or escape only
    – Rated for up to 4 hours of use
    – Recycles exhaled air, removing carbon dioxide and replacing oxygen
    – Closed-circuit escape respirators (CCERs) can be used to escape from IDLH environments
    – CCERs are sometimes referred to as self-contained self-rescuers (SCSRs), especially in mining