Ordinary cotton-spun or cotton masks do not effectively block droplets and only protect against vapors or large particles, so ordinary cotton masks cannot be used to protect against novel coronavirus pneumonia. When you go to places with little traffic, you can get better protection by using ordinary medical surgical masks. Try not to use cotton masks when going out. If you are going to a strengthening ward, hospital, nursing ward, or a crowded place, or a place where you may come into contact with a person infected with the virus, it is recommended that you use an N95 mask. Commonly used ordinary blue or gray surgical masks are generally recommended to be used for a cumulative time of no more than 4 hours. If you are at home or have not been to a susceptible area, the mask can be disposed of directly as household garbage. If the mask is used in a hospital, it should be disposed of as medical waste. Source: Dr. Yurai