Dust Masks, What's in a Rating | N95, P95, N100 etc.
A little online research will reveal that the flu virus is .17 microns in size. Clearly smaller than even N100 masks can filter out. However, it is critical to understand that the flu virus does not float in the air by itself. The flu virus is transported from patient to patient on droplets of excretions from sneezing and coughing.