Sometimes wearing two masks is better than one. Dr. Anthony Fauci has approved wearing two masks for a comfortable, firm fit, and Centers for Disease Control and Prevention (CDC) has found that double masking can improve protection by about 50 percent.
However, double masking may not be necessary if you already have a well-fitting mask, according to a recent study published as a research letter in JAMA Internal Medicine.
Researchers at the University of North Carolina at Chapel Hill tested various combinations of masks on volunteers, from a single fabric mask to duplicate surgical masks. They found that wearing a full coverage mask, such as a sleeve loaf or leggings, over a surgical mask provided the best filtration.
“[This] it makes us understand that double masking is more effective because of the improved fit it offers, not because of the extra layers, ”lead author Emily Sickbert-Bennett wrote in an email to Insider.
The study found that putting a cloth mask on top of a surgical mask also improved fit and filtration. However, the same combination with the surgical mask on top did not provide any additional benefit compared to wearing a single surgical mask alone.
Surgical masks filter particles well, but their fit can be improved
Most surgical masks are made from layers of polypropylene fabric, the same material used to make top-notch N95 respirators. Some are even equipped with an electrostatic barrier designed to trap infectious particles, air virus expert Linsey Marr has previously told Insider.
But surgical masks can get a little tight compared to fabric options. Putting a fabric mask on top combines the top filtering of a surgical mask with an improved fit.
If double masking seems awkward, there are other ways to make a surgical mask fit better. In a CDC study on double masking, knotting the ends of a surgical mask and tucking the fabric so that it would wrap more comfortably around the wearer’s face worked just as well as it doubled.
Other scientists have suggested the use of an orthopedic appliance to make a single surgical mask adhere better to the face.
Double masking is very effective, if everyone does it
Both the CDC study and recent Chapel Hill research found that wearing masks works best when the two people interacting wear well-fitting masks.
“The best way to double-mask is when you and the person you’re interacting with have a mask on,” Sickbert-Bennett said.
This universal masking approach could achieve a 95% reduction in infectious particles, regardless of the well-adjusted option people choose, the CDC study concluded.
This article was originally published by Business Insider.
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