The CDC recommends replacing your face mask as soon as it gets dirty or wet. Continuing to wear a soiled mask can put you at risk of receiving respiratory droplets unknowingly. But if the face mask is in good condition, you should change it depending on the type of mask you’re using.
In the case of cloth face masks, you can reuse them as many times as you can if you keep them clean. The CDC recommends washing them at least once a day to remove any harmful microorganisms that can linger in the fibers.
On the other hand, disposable face masks should be discarded after using them once. As for N95 face masks, it’s best to check the label for instructions on how long you can wear them throughout the day.