• These cartridges include integral high efficiency (99.97 percent against 0.3 micron particles) filters and an impregnated bed of special activated carbon that helps absorb many types of gases • Approved by NIOSH under the NIOSH 42 CFR 84 respirator certification regulations, approved to the P100 filter class, as well as for ammonia, organic vapors, chlorine, hydrogen chloride, chlorine dioxide, sulfur dioxide, hydrogen sulfide (for escape only), • approved to the P100 filter class as well as for ammonia organic vapors • Package of 2