Not only during an epidemic, but also during normal times when disposable masks are generally not reused after washing. Generally, they are cotton or gauze masks, but these masks are generally only able to protect the human mouth and nose from steam or larger particles in the air, so try not to wash the mask during the epidemic and use it again, because after washing it may reduce the mask’s protective ability. For general medical surgical masks or N95 masks, after washing, the protective layer may become thinner, making the middle particle size aperture larger, so if you are going to use surgical masks or N95 masks in densely populated places, try not to wash them, and try to discard them after reaching a certain time, and use new masks to ensure the protective effect. Content source: Dr. You Lai