The North N95 Particulate Filters are NIOSH approved for protection against solid and liquid particles - not including those that contain oil. N95 respirators filters are NIOSH certified to have filter efficiency level of 95% or greater against non-oil based particulates.The North N95 respirator filter can be used with any North respirator facepieces and must be also be used in addition to a North respirator cartridge. These filters also require the use of the North Filter Cover. Includes 10 respirator filters per/package.