Your trusty cloth masks have gotten you through more than a year of pandemic. Heading into the winter, you might want an upgrade.
That's because some disposable masks — like surgical masks and KN95 masks — just plain work better, experts say. And plenty of them are available now, a turnaround from the beginning of the pandemic when the highest-quality masks needed to be reserved for healthcare professionals.
In an August study, currently under peer review, a group of researchers from universities including Yale and Stanford found that surgical masks are 95% effective at filtering out virus particles — compared to just 37% for cloth masks.
That held true even after the surgical masks were washed with soap and water 10 times, though the CDC and the FDA both say you shouldn't reuse disposable surgical masks under any circumstances.
Public health officials in European countries like France, Germany and Austria are currently urging people to wear medical or surgical masks instead of homemade cloth masks — but it's not quite as simple as tossing out your cloth masks and buying a replacement stockpile of disposables.
Here are the biggest differences, and when you should use one type of mask versus the other:
Why surgical masks work better than cloth ones
Assuming they fit properly, cloth masks can do a decent job removing most of the droplets people generate from talking, breathing, coughing or sneezing, says Yang Wang, an assistant professor at the Missouri University of Science and Technology who runs the Particle Measurement & Technology Laboratory.
But, Wang says, you'll be significantly more protected by wearing a higher caliber of disposable mask. Your strongest option is the KN95 mask, which is commonly made in China and filters up to 95% of particles in the air.
If you can't find KN95s, go with surgical masks made from a non-woven plastic material called polypropylene. The material is capable of holding an electric charge, which can attract, intercept and remove foreign particles that might otherwise slip through the cracks of a cloth mask, Wang says.
Surgical masks and KN95s are relatively inexpensive, so you can probably afford to stockpile them: A quick Amazon search for "surgical masks" shows several 50-pack options ranging from $8-$12.
And their quality is relatively consistent, "whereas cloth masks can be quite variable," says Dr. Judith O'Donnell, section chief of Infectious Diseases at the Penn Presbyterian Medical Center and a professor of Infectious Diseases at the Perelman School of Medicine at the University of Pennsylvania.
Why the CDC still recommends cloth masks anyway
You may notice that the above list doesn't include N95 masks. They also provide high-quality protection, but still need to be reserved for medical facilities and people with a very high risk of Covid exposure, says Dr. Lynn Goldman, dean of the Milken Institute School of Public Health at George Washington University, and an epidemiologist by training.
That's why, at the start of the pandemic, the Centers for Disease Control and Prevention recommended cloth masks over all types of medical-grade ones. Today, the CDC maintains that well-fitting cloth masks can still effectively prevent the spread of Covid, though it also recommends surgical masks and KN95s as safe options.
"CDC recommends that the best mask is the one that you will wear consistently and correctly," CDC spokesperson Jade Fulce tells CNBC Make It. "CDC continues to learn more about the effectiveness of different types of masks and respirators for preventing Covid-19."
And many Americans have gotten used to their two or more layers of washable, breathable fabric over the past year and a half. Cloth masks are comfortable, affordable, reusable and sometimes even fashionable.
Their top strength is also the biggest weakness of surgical masks and KN95s, Goldman says: Cloth masks have "far more durability over time," while disposable ones need to be thrown away as soon as they become dirty.
A Massachusetts Institute of Technology study published in July estimated that the Covid-19 pandemic will produce up to 7,200 tons of medical waste per day, mostly from disposable masks.
How to tell which type of mask to use
In crowded situations where you can't maintain social distance for prolonged periods of time — like traveling on a plane or sitting in a classroom or theater — you should definitely opt for at least a surgical mask.
Goldman says she wears KN95 masks while traveling. "Even though I am vaccinated, I feel that I want to do everything I can to avoid becoming infected," she says.
In situations where you won't be near anyone else for more than a brief moment or two, like going to the supermarket or dropping off a child at school, a cloth mask is probably fine, says Goldman.
You also need to pay attention to how your masks fit, regardless of which ones you choose. "A well-fitting cloth mask could be better than or equivalent to a surgical mask that's poorly fitting," O'Donnell says.
Look for something that has a metal bridge to mold over your nose, lies flat across your cheeks and covers your nose down to your chin without gaps along the sides.
In the future, surgical masks could become the norm, Goldman says — especially if the CDC encourages them more significantly.
"Hopefully they'll do that in a way that's simple, clear and concise," Goldman says.
Update: This story has been updated with comments from the CDC.
Correction: This story has been corrected to reflect that the Covid-19 pandemic could produce up to 7,200 tons of medical waste per day, according to an MIT study.
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