Cave & Mine Rescue

 Escape breathing apparatus may be air-purifying escape respirators or self-contained atmosphere-supplying escape respirators. They may use a breathing hood, facepiece or mouthpiece and nose-clip as the user respiratory interface. Atmosphere-supplying apparatus may be rebreathers with a chemical or compressed gas oxygen supply, positive pressure demand apparatus, or constant flow apparatus using high pressure compressed air. Contamination of the breathing gas may be avoided by relying on a good seal around the user respiratory interface, or by a small positive pressure relative to the surroundings.

Escape breathing apparatus are not generally intended to be used for anything other than escaping a dangerous environment. An escape-only respirator is defined as "a respirator intended to be used only for emergency exit".