There is a difference between medical N95 masks and industrial N95 masks. N95 adopts American standards. N stands for non-oily particulate matter. 95 means that the efficiency of filtering particulate matter is greater than 95%. The particulate matter here refers to a diameter less than 0.3 Micron particles. Medical N95 belongs to the management of medical devices because of the word medical, and it has requirements for the protection of body fluids or blood splashes, while industrial N95 has no requirements for the protection of body fluids, but only for the efficiency of filtration. Therefore, hospitals, operating rooms, and high-risk groups should use medical N95 masks when they are suspicious of new coronavirus patients, but ordinary people can choose industrial N95 masks if they do not have the risk of exposure or belong to low-risk groups.