The Weird Trick to Make Your N95 Mask Last Longer—And When You Should Throw It Out

Cloth masks aren’t cutting it. To best protect yourself against omicron, experts suggest you may need a respirator mask (think KN95 masks and N95 masks) or a surgical mask. As SELF previously reported, the low-tech material of cloth mask isn’t as effective at blocking small aerosol particles—respirator and surgical masks are made with at least one layer of polypopylene, which electrostatically filters out these tiny airborne particles. Combined with the looser fit, cloth masks are much less effective at preventing the transmission of omicron. They’re about 25% effective at blocking the transmission of virus-carrying particles overall—which, should be noted, is better than nothing—but far inferior to respirator masks, which are up to 95% effective at blocking the transmission of virus-carrying particles, according to the Centers for Disease Control and Prevention (CDC). 

Getting your hands on disposable respirator masks, however, is getting more challenging. So, how long can you safely wear an N95 or KN95 mask before throwing it out?

According to guidelines for health care facilities issued by the CDC, N95 masks should ideally only be used once, and (un-ideally) up to five times. The more you reuse your mask, the more its fit and filtration performance—the keys to making these masks a sound defense against the airborne transmission of the omicron variant—are compromised. 

Given there’s no end to the pandemic in sight, you’d have to have potentially hundreds of masks on hand if you were only going to use each one once. Which feels nearly impossible. While the CDC officially declared the shortage of N95 masks over for health care facilities in the U.S. in May of 2021, for many people in this country, “a mask is not always affordable or convenient to get,” President Biden said in an address on Thursday, per CNN. Luckily, getting respirator masks may soon be easier—in his remarks, Biden announced a plan to start distributing free masks to people in America, the details of which will be announced next week. 

In the meantime, health experts have some advice for safely prolonging the life of your respirator mask. One strategy is to rotate your masks, storing them in a clean dry paper bag between uses, according to the North Dakota health department. So say you have seven masks, you’d wear one on Mondays, one on Tuesdays and so on. “If you’re rotating your masks, washing your hands and storing them well, you can get five to a little bit more uses with them,” Joseph Gastaldo, M.D., a physician who specializes in infectious diseases with OhioHealth, told USA Today. To make sure any virus particles on the mask die between uses, make sure they’re stored in the paper bag for a minimum of five days, per the CDC. 

Another trick? Put your mask in the oven. Researchers at Columbia University in New York found that heating an N95 mask can kill lingering virus particles. To do it safely, they recommend placing your mask into a paper bag and then placing that into an oven safe bag (like the kind you’d use for a turkey). Place the double bagged mask into the oven at 175 degrees Fahrenheit for 45 minutes and then let it cool. The federal government, meanwhile, recommended the use of moist heat, like that used in a pressure cooker or InstantPot, to disinfect your N95.  

If you are reusing your N95 or KN95 mask, it’s important to ensure that it continues to fit properly, meaning it’s snug enough to create a seal with your face. If the elastic straps start to stretch out, or the nose bridge breaks or loses its shape, it’s time to replace it.