How Long Can You Keep Using the Same N95 Mask?

Omicron continues to overwhelm hospitals and healthcare workers already worn out by Delta. At this stage of the pandemic, and with the healthcare system once again teetering on the edge, experts are urging people to ditch their cloth masks in favour of N95 or KN95 respirators. But these masks are more expensive than surgical masks and not washable like cloth masks, which leaves a lot of us asking: Exactly how long can you use the same N95?

Here’s what the experts are saying about reusing respirator masks.

N95s are technically single-use

All FDA-cleared N95 respirators are labelled as “single-use,” disposable devices. However, this designation is based on the idea of healthcare workers who are using these masks for hours at a time; that “single use” was never intended to describe your quick run to the grocery store.

With the need for daily use of high-quality masks right now, experts are confirming that N95 or KN95 respirators can in fact be worn multiple times–but they can’t be reused indefinitely. Wearing the same mask day in and day out naturally decreases its ability to do its job.

A practical solution: Rotating masks

“For an N95, we’d recommend you switch (the mask) every day,” Dr. Sabrina Assoumou, an infectious disease physician at Boston Medical Centre, told USA Today.

But there’s a prohibitive aspect to stocking up on high-quality masks: Cost. For many, it’s unrealistic or impossible to grab a fresh N95 as often as experts recommend. In this case, you can get by with a rotating mask system. “If you have three masks, (for example), you could number them and switch them around,” Assoumou said.

This is a method Peter Tsai suggested in a study way back in May 2020, when the PPE shortage meant treating patients was increasingly dangerous for healthcare workers. The study found that three days is enough time for any traces of the virus on the mask to die out. This means that if you were to rotate four different N95s, you’ll be able to grab a theoretically COVID-free mask every day of the week.

Our tip to stay organised — and to keep the system effective — is to label or colour-code your different masks and store them in corresponding paper bags. But why paper bags?

Don’t wash N95s; do keep them dry

Should you throw your N95s in the laundry or attempt to wash them by hand? Probably not. Instead, your best bet is to simply allow your mask to dry — and this is where a paper bag comes in.

Storing masks in a paper bag for 24–48 hours between uses is a helpful way to keep them clean and dry between uses, so you can rewear them as safely as possible. “The concern about wearing a mask in public, obviously, if you get particles on it, perhaps even the virus, but if you store it in a dry bag, you are essentially sanitizing again over a period of time,” Dr. Joe Gastaldo, an infectious disease expert at OhioHealth, told WWL-TV.

Keep in mind, however, that the bag isn’t actually magically sanitizing your mask, which could still be crawling with other pathogens. Gary Warren, CEO of ivWatch, a Virginia-based manufacturer of medical-grade N95s, told PopSci to think about it like this: “You don’t clean your underwear by hanging them on the clothesline for a week and airing it out.” But after a few days, any coronavirus present will have died out.

Moreover, the bag will keep your mask away from further contamination, as well as maintain a dry enough environment in order for the virus to not spread or linger on the mask.

When to take a mask out of rotation

According to the FDA, if your respirator is damaged or soiled, or if breathing while wearing it becomes difficult, it’s time to replace it with a new one. An effective mask depends on it making a proper seal around the nose and mouth, so as soon as the noseband starts bouncing back and is no longer able to stay in place or the elastics don’t provide as much tension as they used to, throw your N95 away.

What about the waste?

If you’re (rightfully) concerned with the waste that comes with constantly disposing masks, keep in mind that getting sick and potentially ending up in a hospital also has environmental consequences. CEO of healthcare nonprofit ECRI Marcus Schabacker tells PopSci that if you or someone you’re in contact with is hospitalized, “the amount of waste you create is exponentially larger — I mean, it’s logarithmic in terms of single-use products.” Schabaker explains that instead of just you using and discarding a mask, everyone who takes care of you will be repeatedly wearing and trashing masks, gloves, and more.

Remember: any mask is better than no mask

Wearing any mask is better than not wearing one, so you may want to keep those old cloth masks around as a backup option (ideally to layer over a surgical mask) when a better quality mask isn’t available. Here’s our updated guide to finding and buying a higher-quality mask to replace your cloth ones. USA Today compiled a useful list of online sellers here.

The pandemic is ever-evolving, as is our response to it. Right now COVID is still surging — so do what you can to keep yourself and others safe by getting vaccinated (including your booster) and masking up.