Understanding Respirator, Cartridge, and Filter Markings

Respirators, cartridges, and filters have many markings, and it is important to understand each so you can choose the right ones for your application. An N95 is a rating for a disposable respirator or particulate filter that describes its filtration efficiency. It is based on an approval test performed by NIOSH: The National Institute for Occupational Safety and Health. The N95 rating is part of a NIOSH Matrix. There are three letters and three numbers; the letters N, R, and P designate how well the filter is resistant to oil-based particulates and mists. “N” means it is not intended for use in oil mist, “R” means it is resistant, and “P” means it is oil mist proof. The numbers 95%, 99%, and 100% tell us the filtering efficiency based off the NIOSH approved respirator test. NIOSH respirator ratings are only applicable for particulate filters. These ratings do not have anything to do with filtering chemicals odors. While an N95 rating is useful for most types of dust and debris, a P100 respirator filter is useful for particles like lead and asbestos. A P100 is designated by pink, magenta, or purple color printing on the disposable respirator/filter. Cartridges for reusable respirators also have NIOSH approved markings. Rather than letters or numbers, the classification system uses color codes to designate which specific contaminants the cartridge can help filter out. These colors are standard in the industry and can be found on all cartridges, regardless of manufacturer. The colored labels will also list the contaminants in abbreviated form to further help identify which hazards the cartridge has been approved for. If your work environment contains more than one contaminant, you should always choose a cartridge and/or filter that is appropriate for all the contaminants. Refer to the packaging or user instructions to help identify the performance of each cartridge or filter.