Medical N95 masks and industrial N95 masks are different, N95 uses the U.S. standard, N represents non-oil particles, 95 means the efficiency of filtering particles should be greater than 95%, where the particles are particles with a diameter less than 0.3 microns. Medical N95 because there are two words belong to the medical device class management, the protection of body fluids or blood spatter is required, while industrial N95 on the protection of body fluids spatter is not required, only the efficiency of filtration requirements. Therefore, in hospitals, operating rooms and high-risk groups should use medical N95 masks if they are suspected to be in contact with patients with the new coronavirus, but the general public can choose industrial N95 masks if they are not at risk of contact or belong to low-risk groups.