And many companies now make N95 respirators. But for 3M, which has gone from producing billions to hundreds of millions of ...

FILE - In this March 5, 2020, file photo, Dr. Deborah Birx, Ambassador and White House coronavirus response coordinator, holds a 3M N95 mask as she and Vice President Mike Pence visit 3M headquarters ...

A PLOS ONE study tested the real-world filtration efficiency of cloth masks, medical masks, and respirators, revealing large ...