Sometimes wearing two masks is better than one. Dr. Anthony Fauci endorses wearing two masks for a secure and comfortable fit, and the 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, a recent study found as a research letter published in JAMA Internal Medicine.
Researchers at the University of North Carolina at Chapel Hill tested a variety of mask combinations on volunteers, from a single cloth mask to double surgical masks. They found that wearing a full coverage mask, such as a bandana or gaiter, over a surgical mask provided the best filtration.
“[This] let us understand that double masking is most effective because of the improved fit it offers, not the extra layers, ”wrote lead author Emily Sickbert-Bennett in an email to Insider.
Putting a cloth mask over a surgical mask also improved fit and filtration, the study found. However, the same combination with the surgical mask on top provided no 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 non-woven polypropylene layers, the same material used to make high-quality N95 respirators. Some are even equipped with an electrostatic barrier designed to trap infectious particles, virus expert Linsey Marr previously told Insider.
But surgical masks may not fit properly when compared to fabrics. Placing a cloth mask on top combines the superior filtration of a surgical mask with an improved fit.
If double masking sounds uncomfortable, there are other ways to make a surgical mask fit better. In a CDC study of double masking, tying the ends of a surgical mask and tucking the fabric in so that it wrapped better around the wearer’s face worked almost as well as double.
Other scientists have suggested using a mask bracket to make a single surgical mask adhere better to the face.
Double masking is very effective – when everyone else is doing it
Both the CDC study and the recent Chapel Hill study found that wearing a mask works best when both people are wearing well-fitting masks.
“The best form of double masking is when you and the person you are communicating with both wear a mask,” said Sickbert-Bennett.
This universal masking approach could yield a 95 percent reduction in infectious particles, regardless of which well-fitting option people choose, the CDC study concluded.
This article was originally published by Business Insider.
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