Safety Works SWX00325 Multi-Purpose Respirator Replacement Cartridges, Ov/AG/P100 Long-life cartridges are approved to the Niosh (National Institute for Occupational safety and health) P100 class, so they are at least 99.97% efficient against oil- and non-oil based contaminants, and are oil-proof so they have No time use limitation. Features Long-Life cartridges are approved to the NIOSH P100 Class, so they are at least 99.97% efficient against oil- and non-oil based contaminants, and are oil-proof so they have no time use limitation The cartridges are also NIOSH approved against Chlorine, Hydrogen chloride, Hydrogen Sulfide, and organic vapors The cartridges include integral high efficiency (99.97% against 0.3 micron particles) filters and an impregnated bed of special activated carbon The cartridges are certified by NIOSH with P100/OV/CL/SD/HC approvals USA SHIPPING estimates delivery times and we work to get your item to you as quickly as possible and within those times, but please know it may take slightly longer than the estimate.