Not all industrial masks can prevent viruses, only KN95 or N95 or more anti-particulate masks can play a role in preventing viruses, sponge masks, cotton masks, activated charcoal masks can not play a role in protecting viruses. Virus is mainly transmitted through droplets, the size of droplets is generally 3-5 microns, so only effective blocking droplet masks can protect against viruses. At present, in the new coronavirus epidemic, the government recommends the use of disposable medical masks, medical surgical masks, these two masks because of the special characteristics of the material are able to effectively block the spread of the new coronavirus, but at present the masks are in short supply of resources, the general public in their daily lives and general production activities wear industrial masks, can also block part of the virus and droplets.