How often should we change our N95 NIOSH masks?

This is a problem that many people care about. Most of the N95 masks are disposable consumables, especially when used to prevent infectious diseases caused by the spread of viruses, bacteria, fungi and other pathogens in the air. N95 masks cannot be used for a long time. The surface may cause pathogens to gather and multiply, and eventually pollute the inner surface of the mask, resulting in a greatly reduced disease prevention efficiency. This is slightly different from the anti-smog and industrial dust inhalation. The latter can be worn for a longer time.

Therefore, the time to wear N95 masks depends on the time of microbial aggregation and proliferation. There is a problem of microbial breeding environment changes on the surface of the mask. The mask just taken out from the sealed bag is sterile and does not have too much suitable for pathogen growth. In the microenvironment, with the extension of wearing time, the moisture exhaled by the human body and the fine dust particles attached to the outer surface of the mask with inhalation will converge at the mouth and nose of the mask and gradually form a culture substance suitable for the growth of pathogens. The growth rate of pathogens on the surface of the mask will gradually accelerate as the breeding environment improves, so the mask is most suitable to be discarded before the inflection point of accelerated growth of pathogens arrives. It is estimated that this time should not exceed 4 hours, otherwise microorganisms can penetrate the inner surface Lead to excessive bacteria on the inner surface of the mask.

Of course, some people say whether it is okay for me to change it once an hour. I think it is completely possible, but after all, N95 masks are expensive and there is no need to change them frequently. If the protective effect is still good, it is more appropriate to continue to use.