coronavirus pandemic

Everything You Need to Know About Wearing and Reusing Filtered Masks

The surge of the omicron variant of COVID-19 created more interest in filtered masks - so here's what you need to know.

As we try to get a handle on the latest wave of the pandemic due to the omicron variant of COVID-19, wearing any mask is better than no mask, experts say.

But while health officials previously embraced the saying "my mask protects you, your mask protects me", they recently modified that guidance to place a greater emphasis on masks that best protect the wearer too. Now they're acknowledging the usefulness and quality of respirator masks, also called filtered masks.

The CDC updated its mask guidance in January 2022 to mention N95 and KN95 masks, according to NBC News.

"To protect yourself and others from COVID-19, CDC continues to recommend that you wear the most protective mask you can that fits well and that you will wear consistently," the CDC website says.

Previously, the agency resisted recommending top-tier masks, fearing there wouldn't be enough for health care workers. But now there is a greater supply and filtered masks are available on Amazon and other sites — but buyer beware, because they are not all legit.

For answers to all your questions about masks (including how to avoid buying a fake), we've got you covered.

Why is it better to wear a filtered mask?

Filtered masks are also referred to as respirator masks. When you wear an N95, KN95 or KF94 mask with a tight fit, it can filter out many tiny, microscopic particles like the COVID-19 virus before they reach your nose and lungs.

Studies have shown cloth masks, bandanas, balaclavas and gaiters are less effective at preventing the spread of the virus. Actually, one study found that neck gaiters produced more particles than wearing no mask at all, since the fabric was breaking up large particles into smaller ones.

I've heard of N95 and KN95, but what is a KF94 mask?

Like KN95, KF94 is another international standard that measures the percentage of particles the masks are able to filter out, according to Aaron Collins, who uses the nickname "Mask Nerd" online.

KN95s are held up to a Chinese standard, while KF94 is the standard used in South Korea, Collins said. (KF stands for "Korean Filter.")

"It's actually regulated by the Korean FDA, so those are much less likely to be counterfeit," he added.

Which mask is right for you and when do you need it?

Aaron Collins, also known as @masknerd on Twitter, explains what you need to know about high-filtration masks like KN95s, KF94s and N95s, which are able to filter out viral particles and can help you stay safe amid the spread of the Omicron variant of COVID-19.

Collins says KN95s usually have ear loops, so they may protect you less since they do not have as tight of a seal on your face.

N95s typically have headbands, which may help them adhere more tightly — and thus, provide more filtration.

"It's a little harder to get on and off, but it does give better protection," Collins said.

Dr. Jay Wolfson, a public health professor and administrator at the University of South Florida, says it's a good idea to wear a more protective mask when you are more likely to encounter people who could get you sick.

"If you're not going to be in a place for a very long period of time, you want to use the thicker [masks], especially if it's congested," he said.

Thick filtered masks can be uncomfortable to wear for long periods of time, though. Depending on your office, you might be able to get away with wearing a surgical mask, Wolfson continued.

"And the more crowded it gets, you can double up on those, it just makes it easier to breathe and less uncomfortable around your ears and around your nose," said Wolfson.

Which masks should not be reused? Can I reuse an N95 mask?

Some heavy-duty masks can be reused and still provide protection from COVID-19, says Dr. Jay Wolfson of University of South Florida. He tells you when you should double-mask, and what you should avoid doing if you want your masks to be reusable.

Surgical masks are not designed to be worn for a long time or in crowded settings, according to Wolfson.

But you can get more mileage out of a KN95 or N95. Just don't wash them! Let them sit out for a day and they can be worn again.

"Have a few of them around so you don't use the same one every day. ...Use your common sense depending on where you are and what you think the relative risk is in terms of congestion," Wolfson said.

Trying to figure out if masks are legitimate or counterfeit? Here's what to look for

"There are lots of fake things going around because it's opportunistic," Wolfson said.

He recommends looking at the name of the company that's on the mask; some masks also have codes printed on them. You could try searching online for that code and seeing what results you get.

Legitimate N95 respirators have to be certified by the National Institute for Occupational & Safety Health (NIOSH). NIOSH publishes a list of approved masks that meet their standards and have earned the right to be called N95s.

If your mask is not an N95, but claims to be NIOSH-approved, that's not right. NIOSH only looks at N95s. A KN95 mask claiming to be NIOSH-approved may be counterfeit.

The CDC keeps track of masks that are counterfeit or have been labeled N95 without working for it.

N95s and KN95s could be $1.50 to $2 per mask even when bought in bulk, Wolfson said. "If you're getting things for 50 cents, they're likely not N95s or good KN95s," he added.