Mask is a health supplies, generally refers to the mouth and nose to wear parts of the air used to filter into the nose and mouth, in order to block harmful gases, odor, droplets out of the wearer's mouth and nose appliances, made of gauze or paper.
　　Masks have a certain filter effect on the air entering the lungs. When the epidemics of respiratory diseases are prevalent, wearing masks has a very good effect when operating in polluted environments such as dust.

Replace the mask Reason:
　　1.The mask is contaminated with foreign matter such as blood stains or droplets
　　2.The user feels that the respiratory resistance becomes large
　　3.Masks damaged
　　4.When the user feels that the respiratory resistance is great, the dust on the filter cotton has been filled with dust particles, and should be renewed.
　　5.Anti-virus filter box, in the mask and the user door in close contact with the case, when the user smell the smell of toxic substances, the renewal of the.
　6.Ordinary masks wear 2 hours or so need to clean, wash with water before soaking 5 to 8 minutes. Activated carbon masks can generally be used for 2 days, n95 can be used for a week. If the mask is not cleaned after a long time to wear, or to re-wash before wearing as well.