SAVER Highlight: Chemical, Biological, Radiological, and Nuclear (CBRN) Self-Contained Breathing Apparatus (SCBA) [May 2008] [open pdf - 260KB]
"SCBA [Self-Contained Breathing Apparatus] are an essential component of personal protective equipment (PPE). An SCBA is an atmosphere-supplying respirator which utilizes a breathing air source designed to be carried by the user. An SCBA consists of a facepiece, harness, hose, first and second stage regulators, and an end-of-service time indicator (EOSTI). SCBA are typically rated for 30, 45, or 60 minutes of service life, but may be rated for other service lives in accordance with the Occupational Safety and Health Administration (OSHA) regulation 42 CFR Part 84. Variations exist in harness designs, cylinder types, and facepieces."
Department of Homeland Security: https://www.dhs.gov/