LULU GARCIA-NAVARRO, HOST:
Until you get a vaccine, wearing a mask is the most effective thing you can do to keep yourself and others from getting sick. And yet a year into this pandemic, there continues to be a great deal of confusion about masks. The problem, says our next guest, is that not all masks are created equal. Jeremy Howard is a research scientist at the University of San Francisco and the co-author of "Why Aren't We Wearing Better Masks?" which recently appeared in The Atlantic. Welcome to the program.
JEREMY HOWARD: Thanks so much.
GARCIA-NAVARRO: Today, the market is flooded with cloth masks, designer masks, surgical masks, N95s, KN95s. I want to go through them just so that we can sort of have an understanding of sort of the many, many options that are out there and which ones are better for our health. Let's start with cloth masks. You say they're not all created equal. Why not?
HOWARD: Sure. So yes, they are useful. But, specifically, what they're useful for is protecting others from you. On the whole, though, they don't do a great job of protecting you from others.
GARCIA-NAVARRO: The advice, though, about cloth masks is changing. Several countries - France, Britain, Germany - are now urging or requiring residents to abandon their cloth masks and wear a medical-grade or surgical-grade mask instead. Why?
HOWARD: We need to be careful here. A surgical mask, generally called a procedural mask, isn't actually much use at all unless you add something called a mask brace to it. What actually works well - the medical respirators under certifications like N95 or KN95 or so forth. These do a fantastic job at stopping respiratory particles from coming in. So they protect the wearer very well indeed.
GARCIA-NAVARRO: So what is the difference, though, between them, N95 and KN95s? I mean, I see the number 95 in there. That would suggest that they filter out 95% of particles, I'm assuming.
GARCIA-NAVARRO: So why the K in front of one and the N in front of the other?
HOWARD: Yeah, great question. KN95 is the certification they use in China. And N95 is the one that we use in the U.S. The big difference is really that the KN95 masks are the ones that have been hit with a lot of fraud. And so if you buy something that claims to be KN95 certified, it isn't necessarily actually the case.
GARCIA-NAVARRO: So what do we do? If I am someone who wants to buy a KN95 mask, how do I go about it? And do you recommend it?
HOWARD: The honest truth is it's very, very hard. We actually need the government to step in and do a much better job of certifying products. Right now, I would say if you can buy something which is clearly labeled as to where it was manufactured and you can find your way through the FDA website to figure out whether this thing's actually real and it works, go for it. Otherwise, more realistically, buy a cloth mask with a nose wire and room to put in a piece of special filter material.
GARCIA-NAVARRO: Do we wash N95s? Do we throw them away after every use? I mean, if we're using them every day, that gets expensive.
HOWARD: We're pretty sure it's fine to keep wearing them. Don't wash them, that's for sure. If you do want to sterilize them, you can put them in a slightly warm oven at 160 Fahrenheit for half an hour. Even that - honestly, probably not necessary. I would just have three of them and use a different one each day and just rotate.
GARCIA-NAVARRO: Jeremy Howard is a research scientist at the University of San Francisco and a co-founder of #Masks4All, a nonprofit focused on mask education. Thank you very much.
HOWARD: Thank you. Transcript provided by NPR, Copyright NPR.