Protection Factors of Self-Contained Compressed-Air Breathing Apparatus

Abstract

Abstract A comparison of protection factors for several makes of self-contained breathing apparatus in the demand and pressure-demand modes are given. Protection factors were determined by quantitatively measuring the in-mask concentration of a test gas. The protection factors obtained illustrate the wide range of mask leakage occurring with various facial shapes and how these are influenced by such factors as talking, the wearing of spectacles, deep breathing, and head movement. The test methods are also described.