FACE MASK WITH BACK-UP SMOKE INHALATION PROTECTION AND METHOD OF OPERATION

摘要

A self-contained breathing apparatus (200) for emergency response personnel has face mask (208) with a first port (214) connected by a hose (206) to a tank of compressed air. Back-up smoke inhalation protection is provided for imminent life-threatening situations by configuring a face mask with a canister (224) containing a filter medium (234), an inlet opening (226) through which air enters, and an outlet coupling (230) for attachment to a second port (218) of the face mask. In normal situations the mask is supplied with air from the tank, but should the tank supply become depleted, the canister can be activated. A use evidencing mechanism is operatively connected to the canister to indicate use of the air filtering system. This mechanism may be a non-reusable cover (236) applied over the inlet opening, and/or a valve in the second port of the face mask with a portion that breaks away upon opening of the valve.