KN95 masks are non-oily particles with a filtration efficiency greater than or equal to 95%, which can isolate viruses. Under normal circumstances, it is recommended to replace it every 4 to 6 hours, the longest is not more than eight hours. In addition, when the mask is damaged, deformed, unable to fully fit the face, or increased respiratory resistance, or it may be sprayed, After being contaminated with body fluids and secretions, it cannot be used anymore.
However, in the special period of the current outbreak of new coronavirus, the number of masks is scarce. If the mask does not exist, people can extend the use time or increase the number of times according to the specific situation. Wash their hands before wearing the mask to avoid pollution Masks, go out for a short period of time, when the mask is clean, you can hang the mask in a dry, ventilated, hygienic environment to dry the mask and reduce the smell of the mask. You can continue to use it next time you go out, but it is not recommended to repeat it for a long time. Use it, and replace it with a maximum of 3 or 4 days.
In addition, some people use water or alcohol to sterilize in order to increase the use time of the mask. This is incorrect. Doing so will cause the mask structure to deform and damage the filter material of the mask, which will greatly reduce the filtering effect of the mask. Not to isolate the virus.