Non-N95 or surgical masks, even if they do not penetrate water, do not resist the spread of the new pneumonia virus. The virus is transmitted by droplets and it is recommended that the general public wear surgical masks and medical personnel wear N95. the rest of the types of masks, even if they do not seep, will not provide good protection. The cloth on the surface of general masks is polypropylene spunbond nonwoven fabric. Polypropylene itself is a hydrophobic material, and after making it into spunbond fabric for masks, it is naturally hydrophobic as well. Unless greater pressure is applied to such materials, it is difficult for water to penetrate. Many shoddy masks on the market also use spunbond nonwoven polypropylene materials that can be waterproof on the surface, but for the middle layer of the mask that plays a core protective role with electrostatic meltblown fabric, some shoddy masks use spunbond fabric to impersonate, and some use meltblown fabric without electrostatic. Therefore, only by whether the waterproof to identify is not reliable.