These cartridges include integral high-efficiency (99.97% 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, formaldehyde, hydrogen fluoride and methylamine gases.