What is the difference between a PM2.5 mask and a KN95 ...
Jun 04, 2020·As we now know, KN95 is a mask rating. PM2.5 refers to “particulate matter” or a fancy way of saying “pollution particles” that are in the air. The 2.5 refers to the size of these particles as being 2.5 microns or smaller. This picture can give yo...