How long can I wear an N95, KN95, or KF94?


A: About 5 times for general use (not in a healthcare setting), maybe a few times more.

TL;DR: Last week, the CDC said that cloth masks are not as good as other masks. Even though the package may say they can only be used one time, you can safely use them for longer.

So what are the tips you can use to extend the life of your N95, KN95, or KF94?

➡️ Don’t touch the mask when putting it on or taking it off. Hold it by the ear loops.

➡️ Use one per day, place in a brown paper bag or a mesh bag between uses.

➡️ Rotate them by day. If you have seven, you have one for every day of the week.

➡️ Store safely and out of the way. Don’t touch them after you remove them. Let them air out for at least 24-48 hours, more if possible.

⛔ Do NOT try to clean your mask. Decontamination strategies are out there, but probably should not be done at home. We don’t have clear guidance on this. This is likely for industrial settings and was applied when supplies were short.

If you do all of this, you SHOULD be able to use your mask multiple times. That is assuming that you don’t get the mask wet, dirty, or that it loses function. The mask should still fit well.

How do I know if my mask still fits well?

➡️ You should have no gaps between your face and the mask.

➡️ You should feel a little bit of push/pull when you breathe in and out. This means that the fit and seal are good on the mask.

➡️ When you gasp, you feel the mask tighter on your face or you see it moving in and out.

🕯️ Some people even try to blow out a candle to make sure their mask still fits well! If you CANNOT blow out the candle, your mask still fits well!

So if your mask still does all these things and you are within about 5 uses, you can still keep using it. But how do you know when it isn’t?

When do I know if my mask needs to be thrown out?

🚫 If it has a cut or tear.

🚫 If it looks like it is breaking down (loose fibers).

🚫 If the straps are stretched out, which could make it too loose.

🚫 If it is dirty, even if is has makeup on it or oil from your face.

🚫 If the mask got really wet, in the rain or after a giant sneeze.

Most recommendations for N95s and similar masks are meant for medical settings. For people who are healthcare workers or in high contact settings, the CDC recommends no more than 5 mask uses. This means any time you take it off. For example, if you eat a meal, then put it back on, that is 2 uses. This is because people touch the mask and potentially contaminate other parts of the mask and/or stretch out the mask when taking off/putting back on. For many healthcare workers, one shift will include five uses of a mask and/or the mask may no longer be usable after a shift.

Experts also state that about 40 hours of use is the maximum one can use a mask. For the general population, this limit is not as clear.

For most people, you should think of your daily activity level and when/how you are using the mask. Are you wearing it just to go to the grocery store? That is probably pretty low risk and light use of your mask. Are you wearing it all day and talking, interacting with multiple people? That probably counts as a little higher use.

In sum, the CDC recommends non-cloth masks and many people are buying N95s or similar masks. These masks are supposed to be for single use, but can be used more times for general use, outside of healthcare settings. You should use them not more than 5 times, store them in a bag between uses, check to make sure they fit well, and make sure they aren’t dirty or torn before you use them again.

We hope this helps!

Stay safe. Stay sane.

With love,
Those Nerdy Girls

Additional Links:

Dear Pandemic Mask guide

Make sure you are putting your mask on/taking off properly (CDC)

How to put on/off an N95 in pictures

CNN with Linsey Marr care tip recommendations

Good tips from Smithsonian Magazine

If you want to see if your N95 is real, check here

If you want to know more about standards for masks, you can see here

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