Powered air-purifying respirators with cartridges provide respiratory protection against gases and vapors by using sorbents to purify the inhaled air. Cartridges without particulate filters do not remove dust, fibers and other particles. North offers a selection of cartridges to provide respiratory protection against a range of industrial air contaminants. In addition, the P100 particulate filter and combo cartridges provide protection against aerosols by removing dusts, mists, fumes, fibers and other particulates; 99.97% minimum filter efficiency. All cartridges are NIOSH approved; meet 42 CFR 84 requirements, when used with North Compact Air™ PAPR and Primair™ series hood systems. 3 cartridges per box. 4 boxes per case. Sold by the case.