KN95 respirators are Chinese in origin and considered functionally equivalent to the U.S. N95 respirator. However, slightly different criteria are used to certify their performance, such as the filter efficiency, test agent and flow rate, and permissible pressure drop.
An N95 mask or N95 respirator is a particulate-filtering facepiece respirator that meets the N95 standard of the U.S. National Institute for Occupational Safety and Health (NIOSH) air filtration rating, meaning that it filters at least 95% of airborne particles, while not resistant to oil like the P95. It is the most common particulate-filtering facepiece respirator. It is an example of a mechanical filter respirator, which provides protection against particulates, but not gases or vapors.