How Many Times Can You Reuse Your N95 Mask?

Cyra-Lea Drummond, BSN, RN, is a writer and nurse specializing in heart health and cardiac care.

Nick Blackmer is a librarian, fact-checker, and researcher with more than 20 years’ experience in consumer-oriented health and wellness content.

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The Centers for Disease Control and Prevention (CDC) has not yet officially advised the general public to wear N95 respirators to protect themselves against the Omicron variant of COVID-19. But research indicates that N95 respirators are far better at protecting you from COVID than cloth masks and surgical masks.

One reason N95s are so effective is that the respirators must pass tests that show they can trap at least 95% of particles in the air. Other types of face coverings capture less than that, which means they offer less protection.

Buying disposable N95 respirators and discarding them after each use is costly. If you have a few N95s on hand, you might be wondering if they need to be thrown out or cleaned regularly.

Here's what experts say about how long you can safely reuse your N95 respirator, how to extend the life of an N95, the evidence-based methods for decontaminating your mask, and signs that it's time to replace your mask.

The U.S. Strategic National Stockpile is distributing N95 masks to the public for free. You can get free N95s at most large pharmacy chain stores.

The amount of time you can use an N95 respirator depends on several factors, including the manufacturer specifications and how much time you spend wearing the mask.

Devabhaktuni Srikrishna, an air quality engineer and the founder of Patient Knowhow, told Verywell that when it comes to replacing an N95 respirator, "loss of seal is the most important factor," because "the seal is going to go out sooner than the filter, and once you lose the seal, air goes in and out."

Signs of a poorly-fitting mask include straps that do not stay securely in place or air leaking from around the respirator.

Over time, the electrostatic charge that traps particles can also weaken. As you continue to wear the mask, the N95 filter will trap more and more particles from the air. The longer you wear it, the harder breathing through the respirator becomes. This is another sign it's time to replace your respirator.

A January study conducted by Beth Israel Deaconess Medical Center found that N95s could be used as many as 25 times before they were no longer functional. However, this number likely skews high for the average consumer. Researchers were able to decontaminate the masks with vaporized hydrogen peroxide between uses—something you can't do at home.

Some N95 respirators are made to be used longer than others. They have filters that the wearer can replace from time to time. However, these masks are not always a cost-effective option for people who do not need to wear an N95 continuously.

3M, a manufacturer of N95s, recently released guidance on reusing its masks:

The easiest way to decontaminate your mask is to place it in a dark, dry place between uses.

To preserve the filter, Srikrishna said, "It's better to keep your respirator in the dark (such as a brown paper bag) than out in the sun," as bright sunlight can break down filter particles.

Srikrishna recommended having several masks that you can switch out. That way, you do not have to wear one mask on consecutive days. According to Srikrishna, "the rotation lets the mask dry out and lets the bacteria and viruses die off."

Evidence does not support washing an N95 respirator, spraying it with disinfectant, or tossing it in the dryer.

Likewise, putting an N95 in the microwave is not effective. It's also dangerous if the mask has a metal nose bridge or staples.

N95 masks can be used more than once as long as you understand the best practices for reusing them.

To learn more about the latest research on reusing N95 respirators, visit the N95Decon public resources page.

The information in this article is current as of the date listed, which means newer information may be available when you read this. For the most recent updates on COVID-19, visit our coronavirus news page.

Yen CF, Seeley R, Gordon P, et al. Assessing changes to N95 respirator filtration efficiency, qualitative and quantitative fit, and seal check with repeated vaporized hydrogen peroxide (VHP) decontamination. Am J Infect Control. 2022;50(2):217-219. doi:10.1016/j.ajic.2021.11.005

By Cyra-Lea Drummond, BSN, RN Cyra-Lea, BSN, RN, is a writer and nurse specializing in heart health and cardiac care.