Cotton masks cannot prevent viruses because the aperture of ordinary cotton masks is too large and the material itself is not dense enough to filter viruses. Cotton masks can only be used in daily life to protect against dust, car exhaust, chemical irritation, etc. They can also be used for warmth in cold windy weather and can be washed and dried for reuse in daily life. Wearing a mask is mainly the main way to break the spread of virus droplets, only medical masks can prevent viruses, unlike ordinary cotton masks, application masks are divided into three layers inside and outside, the middle becomes the isolation filter layer, the outer layer is a special material antibacterial layer. At present the new coronavirus epidemic under the shortage of masks, ordinary home people with good ventilation and low staff density places can not wear masks, non-medical masks such as cotton gauze, activated carbon, sponge and other masks also have a certain protective effect, can also reduce the role of coughing, sneezing or talking generated droplet transmission, can be used at your discretion.