Blog

Respirator filters are rated according to how much particulate matter they can reliably block. A P100 rating is the highest for personal respiratory protection. As long as your mask fits properly a P100 filter will block 99.9% of particles .3 microns or larger. (If you're interested in the nitty-gritty the CDC has a comprehensive and fairly unreadable guide to particulate respirators.) In defense of the CDC, there are a huge range of hazards, and not everyone can wax poetic about lun …