Dust Masks:fit And Filtration Matter Most

摘要

As a retired professor who taught environmental technology, I was pleased to read your article on dust masks and respirators ("Protect Yourself From Wood Dust," FWW #201). But I think it was a mistake to recommend all masks with an N95 rating or better. The ratings, in this case N95, N99, and N100, refer to the minimum percentage of respirable airborne particles that a mask filters out. An N95 mask filters out at least 95%; N99, 99%; and N100, 99.97%. Respirable (breathable) airborne particles are the very fine (usually invisible) particles that cause the most lung damage. Therefore, an N95-rated mask would theoretically allow five times more of these dangerous particles than an N99, and 167 times more than an N100. This is just as, if not more, important than comfort, which you emphasized.