I have a PM2.5 mask. Will it protect me from coronavirus ...
Apr 29, 2020·PM2.5 stands for Particulate Matter 2.5μm; it’s not necessarily an actual mask rating. It sounds like that mask is intended to filter out air pollution, since that’s typically measured at 10μm (microns/micrometers) and 2.5μm. PM2.5 is more likely ...