It can be hard to keep finding fresh N95 masks, even if you have an awesome local mask distro helping out. Here's how you can make them last.
An N95 mask expert says:
"If it gets really dirty. So, sometimes I see people walking around, and these white respirators look very brown. My guess is they've probably come right from a construction site, and they're wearing them at the grocery store. If [it's] getting really discolored, it's really dirty, and then it's probably time to get a new one...."
"If it becomes damaged. So, if you see a strap break, if your nose clip breaks, if the nose foam falls off, then it's time to get a new respirator."
"Or if it becomes difficult to breathe through — and that's going to happen for certain workplaces where there are higher dust levels. It's [unlikely to] get enough particles in there to be difficult to breathe through when you're just going to the grocery store, or if you're wearing it at a job where there's really not a lot of dust."
"If it doesn't seal to your face anymore." For instance:
"If that nose clip just doesn't bend anymore, because you've you've bent it a number of times."
"Or the headbands are too stretchy. So, when you put it on, it kind of falls away from your face. If you don't feel like it's touching your face all the way around...then it's time to get a new one."
If it's anything less than soaked, you're probably fine. Just let it dry out thoroughly before the next use.
Not with home equipment, sad to say. Your best bet is to let it self-sterilize by resting for 24-48 hours in a paper bag. That way, it can dry out but it can't get dirty. Keep masks separate so they don't cross-contaminate. Using alcohol or detergents will destroy the electrostatic charge that makes it work.