The best masks to protect against COVID

“A mask that protects you from COVID needs to have a few key qualities. It should be multi-layered, fit snugly around your nose and mouth, and keep air from leaking in or out,” says Dr. Allegreti. “Since COVID spreads through respiratory droplets when people cough or sneeze, your mask needs to keep these droplets out. A droplet is about 5 micrometers long. That’s tiny—a strand of hair is more than 3 times as thick. The best masks keep even these tiny particles out.” 

So which is the best type? Dr. Allegreti says that in an ideal world, the best option is an N95 respirator mask when it comes to preventing COVID-19. Don’t let the name fool you, though—this isn’t a huge, clunky, awkward device. N95s get their name because they filter out 95% of airborne particles. Their shape, wire bridge over the nose, and straps behind the head provide a close seal, and their tiny pores filter out respiratory droplets and offer the best protection. All N95s are evaluated and approved by NIOSH (the National Institute for Occupational Safety and Health), a branch of the CDC, to make sure they meet high quality standards (NIOSH, 2019). 

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Since N95s are usually reserved for healthcare workers, they can be pretty hard to find. A very similar option is the KN95, which also forms a close seal around your nose and mouth and filters out 95% of particles from the air. The primary difference between an N95 and a KN95 is where they were certified. N95 masks are made according to standards set in the United States, and KN95 masks are certified by standards set in China (Asadi, 2020). 

KN95s must be approved by the U.S. Food and Drug Administration (FDA) and go through a process called “fit testing” to make sure they fit well and filter air as promised. NIOSH offers a video to show how to do your own fit testing to make sure that your mask fits appropriately. 

“Cloth and surgical masks are widely available and are often less expensive and easier to find,” says Allegretti. “They aren’t always the best option, but in a pinch, you can use them.” They aren’t as protective as N95s or KN95 respirators. Respirators form a seal around the face and can protect the person wearing the mask from catching coronavirus. Cloth masks and surgical masks may help protect the people around you if you happen to be carrying the virus, but since they're looser-fitting, don’t form a seal, and have larger pores, particles can more easily enter when you breathe in (CDC, n.d.).

If you wear a cloth mask or surgical mask, they likely won’t prevent you from catching the virus if you spend time around someone who is infected. This is especially important for strains like the omicron variant, which is extremely contagious (Garrett, 2021; Brussow, 2021).

Allegretti explains that there are things you can do to boost the protection you get from cloth or surgical masks. “You can choose multi-layer rather than single-layer cloth masks and create a tighter seal by knotting the mask straps more tightly. You can choose a mask with straps that you secure behind your head rather than ear loops. You can also double mask—wear a cloth mask over a surgical mask to build a better barrier.” 

The CDC offers guidelines on where and when you should wear a mask. But these guidelines change based on a person’s vaccination status, health status, and the current state of affairs when it comes to the pandemic. Their current recommendation is that everyone older than two years should wear a mask inside public places like restaurants and shops and on public transportation like buses, planes, and trains (CDC, 2021-a; CDC, 2021-b). 

Some guidelines vary by location because the amount of cases in a given area changes constantly. “If you find it impossible to keep up with the changes, you’re not alone,” says Allegretti. Luckily, though, the CDC knows it—so they’ve developed a solution. Their website offers an interactive tool that lets you select your state and county to find updated guidelines for your specific area.  

“The answer to this question is trickier,” says Dr. Allegretti. “One of the hardest parts of the pandemic for many people is being separated from friends and family. If you’re fully vaccinated and want to spend time indoors with others who are vaccinated, keep track of local case counts, and consider getting your whole crew tested.” 

“Getting tested before you gather is one strategy that some people opt for, but it’s not foolproof. Taking precautions when appropriate and learning to live with the virus is something we’re all getting used to,” she added. 

CDC guidelines state that outdoor gatherings are safer than indoor, and small indoor gatherings are safer than large ones. If you plan on attending an indoor gathering, you can take extra precautions by doing a self-antigen test before you go (CDC, 2021-c). A negative test means you’re less likely to be infected and significantly reduces the risk of infecting others. If everyone attending a gathering is fully vaccinated and has a negative antigen test on the day of the event, the risk of infection is low.  

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How we reviewed this article

Every article on Health Guide goes through rigorous fact-checking by our team of medical reviewers. Our reviewers are trained medical professionals who ensure each article contains the most up-to-date information, and that medical details have been correctly interpreted by the writer.

Current version

January 05, 2022

Written by

Health Guide Team

Fact checked by

Yael Cooperman, MD

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About the medical reviewer

Yael Cooperman, MD, Ro

Yael Cooperman is a physician and works as a Senior Manager, Medical Content & Education at Ro.