Abstract: An Emergency Respirator of a half mask type for in-home or institutional use including a filtration canister housing two carbon elements and two fiberglass elements. The canister is preferably constructed of stamped sheet aluminum or plastic held together by a split U-shaped retaining ring or snap fit clips cast into the casings. A cover forming a plenum is also fixed in place by the retaining ring or snap fit clips. The cover has a bushing for connecting a mouth cover to the respirator. The mouth cover is of an elliptical shape with a central opening to receive the bushing. Valve covers are disposed over webbed openings in the inner casing and the cover to secure rubber diaphragm valves. Each valve allows air flow in a single direction. The inner casing valve allows air from the filter system to pass into the plenum. Air is expelled through the cover's outer valve.