N95 Masks
Designed to fit tightly on the face, and made from layers of nonwoven materials such as polypropylene or polystyrene, N95s are a staple of medical workers’ personal protective equipment. Authentic N95s are manufactured in the United States and accredited by NIOSH, the National Institute for Occupational Safety and Health.
N95s are in the category of masks called respirators because they provide a barrier from other people’s respiratory emissions, including droplets and tiny airborne particles called aerosols. By contrast, less-protective mask types mostly protect other people from the wearer’s own emissions. The material in N95s also has an electrostatic charge to further repel particles.
Respirators come in a few different styles: Some have a cup shape, others look more like a beak or a duckbill.
As for the name? The number stands for the percentage of airborne particles the masks filter out: 95 percent. According to the CDC, the N stands for non-oil, meaning the masks are not designed to filter out oil-based particles (so should not be used in settings like petrochemical sites).
N95s were in short supply in the early days of the pandemic, and the federal government asked the general public not to buy any they found, so enough would remain in stock for doctors and nurses.
Now N95s are more widely available, but the CDC cautions consumers not to purchase the ones labeled “surgical,” since those are designed to offer added protection against fluid splashes and are meant for use only by health workers.
Pros
N95s are made to create a tight seal around the face, thanks to a nose wire and headbands (instead of the ear loops found on other kinds of masks).
As long as they fit properly, N95s will offer strong protection from virus particles and droplets in the air. It’s also easier to spot an authentic, NIOSH-approved N95 and to weed out the counterfeits (compared with other types of respirators; see below).
Cons
N95s can be pricey, often costing around $2 per mask.
And respirators like N95s can start to feel uncomfortable if you’re wearing them for hours. Some people might be prone to loosen or remove them when that happens, making them ineffective.
“When it comes to respirators, those are a little more challenging because they have a tight fit and are tougher to wear for longer periods,” says Dr. O’Horo.
“Health professionals go through a fitting process to make sure they’re wearing it properly,” adds O’Horo. The fit issue, he explains, “makes me concerned that these respirators are not always working as respirators.”
How to Get the Most From Your N95
NIOSH gives tips on how to put on and take off your respirator, and how to make sure it’s fitting correctly — for example, by holding it against your face with both hands and breathing in quickly to test the seal.
Keep in mind that you should never wear any other mask over a respirator like an N95, since that could cause it to move around, impacting the fit.
The CDC’s website has details about which types of accreditations to look for and what to avoid when buying respirators like N95s. To make sure you’re avoiding counterfeits, you can also buy masks directly from N95project.com.
And if you buy a brand or size that doesn’t fit properly or feel comfortable to you, try another.
KN95 Masks
KN95s are similar to N95s in many ways: Like N95s, KN95s are respirators and are designed to create a tight seal around the mouth and nose. They’re also made with layers of synthetic nonwoven materials like polypropylene or polystyrene, and can filter out 95 percent of particles.
They typically have a pointy-tipped nose, and ear loops instead of headbands.
One key difference is that KN95s are made in China. The K indicates that they’re the Chinese version of American-made N95s. Some people have joked that the “K” means “knockoff,” but an authentic KN95 is a high-quality mask, and the CDC recommends well-made KN95s as protective against omicron.
Nonetheless, fake KN95s are everywhere lately, and consumers need to pay close attention when shopping to avoid buying counterfeits.
Pros
Authentic KN95s are often easier to find than N95s, and thanks to more price competition they can be cheaper. They’re also sold in a variety of colors and patterns.
Cons
Just like N95s, they can start to feel confining after you wear them for a while, and the ear loops can irritate the skin after long periods of wear. If you need a break, make sure to only take your mask off outside, and when you’re at least six feet away from others.
How to Get the Most From Your KN95
You’ll need to do your homework to make sure you’re buying authentic KN95s.
The CDC offers tips on how to spot fakes when buying internationally produced respirators like KN95s (or KF94s; see below). But the information on the CDC site is so technical, it can be difficult for a layperson to sift through it all. And the stakes are high, since counterfeits abound. More than 60 percent of non-NIOSH approved respirators on the market are fakes, according to the CDC.
“It would be nice if there could be clearer guidance on identifying counterfeits,” says Chanu Rhee, MD, MPH, an infectious disease and critical care physician and an associate hospital epidemiologist at Brigham and Women’s Hospital in Boston.
The New York Times’ Wirecutter site offers tips on how to avoid counterfeits when buying respirators, for instance by making sure packaging is “tamper-evident” (not closed with a twist tie) and lists an expiration date and the producer’s name.
KF94 Masks
You’ve likely seen KF94s pop up when you’re shopping for respirator masks online. What are they? While N95s are American-made and KN95s are Chinese-made, the respirators labeled KF94 are produced in South Korea. KF stands for Korean filter.
They also have a distinct shape, with a wide panel in the middle, an adjustable nose clip, and side flaps to help the mask fit closely against your face.
Authentic KF94s are effective against omicron, according to the CDC, and deliver nearly the same amount of protection against particles as the other two kinds: 94 percent.
Pros
Authentic KF94s offer a high-quality alternative to N95s and KN95s, and they’re widely available.
When a KF94 is on securely, it typically leaves slightly more space inside the mask around the nose and mouth than an N95 or KN95, so it can be more comfortable to wear for long hours.
Cons
Like KN95s and other internationally made respirators, KF94s are not regulated by a U.S. agency, so it’s all too easy to sell counterfeits on the open market.
How to Get the Most From Your KF94
As with other respirators, you’ll need to familiarize yourself with how to avoid fake KF94s and seek out authentic ones. See above for tips on how to avoid counterfeits when buying internationally made respirators.
Since you can’t try on the masks before you buy them, make sure they fit properly once you purchase them — and avoid buying the same brand again if they don’t.
Surgical Masks
Surgical masks, often called medical masks or procedure masks, are flat, typically blue, and have accordion-style folds in front.
Like respirators, surgical masks are made from materials like polypropylene or polystyrene that effectively filter out droplets and aerosols (although respirators filter out smaller particles than surgical masks do). But the mask needs to fit correctly on your face so it can do its job.
When buying surgical masks, look for ones with multiple layers (such as three-ply), nonwoven material, and a nose wire, says the CDC.
Pros
Surgical masks are easy to find, cheap to buy, and can feel more comfortable than respirators.
Cons
Surgical masks don’t fit as closely on the face as respirators. “The material is good,” Dr. Rhee says, “but for some individuals, when they wear a surgical mask, there are large gaps on the side.”
How to Get the Most From Your Surgical Mask
If your surgical mask fits too loosely, secure it with a cloth mask on top, or knot-and-tuck the ear loops. (The CDC recommends viewing their how-to video.)
Another way to improve the fit is to wear a cloth mask over — but not under — your surgical mask. Your surgical mask should create a shield around your mouth and nose, and the cloth mask can then fit over it to secure any gaps.
“The cloth mask helps the surgical mask conform better to your face, and improves the fit,” Rhee explains.
Cloth Masks
These are the easiest kinds of masks to find: Nearly every grocery store and clothing shop sells them, and fashion brands, athletic companies, small vendors on Etsy, and seemingly everyone with a sewing machine ventured into making cloth masks since the early months of the pandemic. Cloth masks are available in all kinds of fabrics and styles, and range from a few bucks each to double-digit price tags.
The CDC’s recent announcement that cloth masks don’t protect as well against omicron as respirators and surgical masks might make people want to toss theirs or avoid buying them altogether. But well-made cloth masks can still play a role in preventing COVID-19 infections if they’re multi-layered, fit well, cover the nose and mouth thoroughly, and are worn consistently. They’re also worth keeping around if they’re helping keep your surgical mask in place.
Some cloth masks even come packaged with paper filters. Does that make them better? “I’m not sure those are strictly necessary,” says O’Horo. “but since we know that it’s layers that give masks their quality, it’s reasonable to say that adding a layer can add additional filtration.”
Pros
Cloth masks can be more comfortable than respirators and surgical masks. They’re also available in nearly every color, pattern, and style, and they’re reusable for longer than disposable masks.
Cons
Single-layer cloth masks or ones with worn-out fabric are not effective at filtering out particles and can pose a danger with a variant as contagious as omicron. Even multi-layered cloth masks don’t provide as much protection — particularly in crowded or other high-risk settings — as do surgical masks and respirators.
How to Get the Most From Your Cloth Mask
Make sure the mask is multi-layered and that it fits closely on your face without leaving gaps, and that it’s also comfortable enough to wear for hours at a time.
Follow the manufacturer’s directions for washing the mask; some should be hand-washed and air-dried. And don’t hang on to your cloth mask for too long (see below).
Is It Okay to Wear Different Masks Depending on the Situation?
It makes sense to assess what kind of situation you’ll be in when deciding what mask to wear, say infectious diseases experts.
The CDC advises a respirator instead of a cloth or surgical mask to guard against infection if you’re immunocompromised; caring for someone with COVID-19; not up to date on vaccines; in crowded settings where you can’t socially distance; on public transportation; or spending long periods of time in environments where people might not be wearing masks correctly or at all, such as in a grocery store.
“If I’m going out shopping and my interactions with other people are going to be minimal or pretty brief, I feel comfortable wearing a surgical mask,” says Rhee. “But if I were working in a job where I had to be coming into contact constantly with other people — say I’m a grocery worker and seeing many people every day — I would consider that differently and try to wear a KN95 or N95.” He adds, “A KF94 is a good option too.”
Rhee says the same factors apply for travel. “With airports and airplanes, by definition you’re in close proximity to other people, and some of them may be taking masks off occasionally to have a drink or to eat.” He adds that in those settings, it’s important to wear “high quality masks like a KN95 — one of those that fit to your face, [and] not counterfeit.”
Is It Okay to Reuse Your Masks?
The short answer: No for surgical masks. Yes for cloth masks. What about respirators?
“I agree with the general public health guidance that it’s okay to reuse them,” says Rhee. “Outside of the hospital setting, it’s not necessary to throw it out after one day if it’s not soiled.” But he adds that it’s important to replace a respirator “when it becomes soiled and when it starts losing fit,” and not keep it longer than a few days. “For N95s, after several uses it begins to lose its seal.”
When should you replace a cloth mask? If you’ve worn and washed it many times, it can lose its efficacy, so if you’ve had yours for a while, it might be time to toss it.
“I have a number of high-quality cloth masks that I got two years ago, but I have my doubts about whether they’re still high quality after going through the wash and getting crumpled up in my pockets,” says O’Horo.
“Unfortunately, there isn’t any good guidance” on when to replace cloth masks, adds O’Horo. “The old rule that I think still holds is that if you hold a mask up to the light and you can see pinpoints of light coming through it, that means it’s a pretty good indication there are gaps big enough for some particles to go through, and it’s time to swap it out.”
Best Masks for Kids
Going to school or daycare all day is “analogous to an airplane or airport setting,” says Rhee. It involves staying indoors for long hours and being around numerous potential contacts; plus, social distancing protocols are not always optimal. That’s why the CDC currently recommends “universal indoor masking” in schools.
Rhee adds, “I have a two-year-old who is in daycare, and we got him to wear a surgical mask. That was a big victory. If I had a little bit of an older kid, I would want my kid to wear a KN95, assuming it’s comfortable and he can tolerate wearing it.”
Ultimately, the upshot is similar for kids as for adults: “It really comes down to what will be worn consistently,” says O’Horo. “A good quality cloth mask worn constantly and that has multiple layers and fits well is better than one that doesn’t fit well or is uncomfortable. What will a child be comfortable wearing for long periods?”
