How Many Times Can You Wear a KN95 or N95 Mask?

May 28, 2023

These medical-grade face masks don't need to be thrown out after each use—but you can't use them indefinitely, either.

In November 2021, the U.S. government SARS-CoV-2 Interagency Group (SIG) classified Omicron as a Variant of Concern (VOC). By April 2022, the Omicron variant overtook Delta to become the dominant strain of COVID-19 in the U.S., making up all coronavirus infections. The reason? While experts aren't sure why, the variant is not only more transmissible than previous strains, and it's better able to evade vaccines, leading to more breakthrough infections.

These two factors are why some experts recommend upgrading their face masks from cloth coverings to the more robust protection of a surgical mask or what's known as a respirator (think: N95, KN95, or KF94 masks).

But a change in mask also requires changing how you use and care for that mask. Those who have gotten used to washing their cloth masks, for example, will have to get used to throwing out surgical masks after every use if they decide to switch.

Dealing with a respirator is a bit different, though: You can't wash them, but they also aren't single-use—so how exactly do you care for these pieces of personal protective equipment (PPE)?

Here, experts help explain how often you should be changing your N95, KN95, or KF94 masks and whether there's any legitimate way to clean them because a face covering is only as effective as how well you use and take care of it.

If you typically wear cloth masks, you're probably used to washing them and reusing them; for surgical mask users, you're (hopefully) tossing them in the trash after each use.

Respirators kind of fall in between the two options: You can reuse respirators (without washing in between uses), as long as you're aware of your risk level and you take care of the mask between uses, Cassandra M. Pierre, MD, MPH, an infectious disease physician and medical director of public health programs at Boston Medical Center, told Health.

There's no hard-and-fast rule about how many times you can wear a respirator before throwing it away. Instead, it's more important to track where you wear the face covering and for how long.

For people who wear their masks for shorter periods or in situations where they remain physically distant from others throughout the day, Dr. Pierre said that it's possible to use the same respirator for up to a week. But for people in high-risk settings, like healthcare facilities, it's best to toss the mask after a day.

Of course, each time you use a respirator—if you're reusing it—you should make sure it's still in good condition. "We recommend every time you use a respirator, you're making sure there are no tears, gaps, or evidence of soiling on the surface," Dr. Pierre told Health. "All these things can impair the integrity and filtration ability of the mask."

Some key ways exist to tell if your respirator has lost its integrity:

Since you can wear a respirator more than once—and because cleanliness is an important factor in reusing your mask—you'll want to store them properly between wears.

Unfortunately, no ways to disinfect or clean respirators are available to the general public, according to Flinn. Any potential ways to clean N95 or other respirators—an area of research health agencies are still looking into—require specific strategies only available in laboratories or other healthcare settings.

One study that often gets attention regarding the decontamination of respiratory masks was published in April 2020 on medRxiv, a preprint server for research that has not yet been peer-reviewed.

The study from the National Institutes of Health (NIH) found that four decontamination methods were able to eliminate various levels of "detectable viable virus" from N95 fabric: vaporized hydrogen peroxide (VHP), 70-degree Celsius dry heat, ultraviolet light, and 70% ethanol spray. The decontamination techniques are helpful in health care settings when respirators are in low supply but aren't really beneficial for the general public.

There is some science behind storing a respirator in a paper bag between uses, though. While those in healthcare settings ideally only use a respirator once, the CDC recognized the shortage of N95 respirators at the beginning of the pandemic and offered options to healthcare workers. In January 2022, the CDC clarified that people could choose respirators such as N95s and KN95s without concerns about supply shortages for N95s.

One suggestion was to store the mask in a paper bag for a minimum of five days. The CDC instructed healthcare workers to have five N95 respirators for each day of the week, storing them for a minimum of five days between uses. According to the CDC, this provided time for some pathogens on the mask to "die off" while in the bag. But even then, the CDC recommended N95s weren't worn more than five separate times.

Throwing out your used N95 or other respirators starts exactly how storing them does: Use clean hands to remove the mask from your face by the ear straps, and be careful not to touch the front of the mask.

Then, it's right into the trash. According to the Environmental Protection Agency (EPA), masks and other types of PPE cannot be recycled and should be kept out of recycling bins. And while it might be tempting just to toss your respirator and be done with it, the EPA notes you should throw it out "securely" so someone else doesn't come into contact with it.

Masking is an important public health strategy for preventing the spread of COVID-19. Experts remind us that any mask is better than no mask. If you are using a respirator, following these best practices will keep you safer and keep your respirator effective at protecting you and others.

Centers for Disease Control and Prevention. SARS-CoV-2 Variant Classifications and Definitions.

Centers for Disease Control and Prevention. COVID data tracker.

Centers for Disease Control and Prevention. How to use your N95 respirator.

Fischer RJ, Morris DH, van Doremalen N, et al. Assessment of N95 respirator decontamination and re-use for SARS-CoV-2. Preprint. medRxiv. 2020;2020.04.11.20062018. doi:10.1101/2020.04.11.20062018

National Institutes of Health. NIH study validates decontamination methods for re-use of N95 respirators.

Centers for Disease Control and Prevention. Implementing filtering facepiece respirator (FFR) reuse, including reuse after decontamination, when there are known shortages of N95 respirators.

Centers for Disease Control and Prevention. Types of masks and respirators.

Environmental Protection Agency. EPA stresses the importance of recycling and proper disposal of personal protective equipment.