Personal disposable emergency breathing system with dual air supply

Abstract

The breathing system comprises a canister carrying layered filtering material, including activated carbon granules, a dessicant, a catalyst for the catalyzation of carbon monoxide to carbon dioxide, optionally lithium peroxide, for conversion of CO.sub.2 to O.sub.2, and electrostatically charged filters between the layers of filtering material. A mouthpiece carrying a noseclip, and inhalation and exhalation check valves and a whistle is disposed within a flexible, substantially completely transparent hear-through hood, both the mouthpiece and hood being disposed in the canister between the filtering material and a cover for the canister. An air flow conduit is connected to an external source of air for supplying air to the mouthpiece and bypassing the filtration unit. In use, the canister is deployed from a compartment, the cover is removed and the hood is drawn about an individual's head and substantially sealed about the neck. With the mouthpiece in the individual's mouth, and noseclip closing off the user's nose, ambient air flows through the filtering material and air from the external source flows through the air flow conduit to the user. A quick disconnect coupling is used to disconnect the system from the external air source whereby the individual breathes only filtered ambient air.