Mask Facts - AAPS | Association of American Physicians and ...
Sep 26, 2020·HEPA (high efficiency particulate air) filters are 99.97 to efficient. HEPA filters are tested with particles that are 0.125 μm (the size of SARS-CoV-2). ... “Medical masks should be reserved for health care workers. The use of medical masks in the community may create a false sense of security, with neglect of other essential measures ...