The higher the concentration of alcohol is not the better its sterilization effect. Only 70%-75% alcohol has the best sterilization effect and can effectively inactivate the new coronavirus. Alcohol concentrations below 70% are too low to effectively kill bacteria or viruses after they enter the body. Alcohol higher than 75% will form a protective film on the surface of the bacteria or viruses after they enter the body, which will not effectively inactivate the virus. It is important to note that when disinfecting with alcohol because of its volatility and low melting point, there is a risk of fire, so when disinfecting with alcohol it is best to use the wipe method, avoid spraying, avoid fire and flammable objects, and turn off the power when disinfecting electrical appliances.