Medline BIOM2001A Biomask Antiviral Face Masks with Earloop, Latex Free, Blue (Pack of 300) BioMask inactivates 99. 99% of tested influenza viruses on 5 minutes contact with the surface of the facemask Tested on specific seasonal flu viruses The first and second layers of the mask are treated with different compounds that inactivate influenza viruses Rapid absorption ensures the influenza A and B viruses are wicked away from the outer surface In the outer active layer, viruses are inactivated by exposure to a low pH environment