- Double masking can improve your protection against the coronavirus.
- Laying a cloth mask over a surgical mask can improve the fit while maintaining the filter well.
- However, wearing a surgical mask over a cloth mask offers no added benefit.
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Sometimes wearing two masks is better than one. Dr. Anthony Fauci endorsed wearing two masks for a snug and comfortable fit, and the Centers for Disease Control and Prevention found that double masking can improve protection by about 50%.
However, double masking may not be necessary if you already have a well-fitting mask, a recent study published as a research letter in JAMA Internal Medicine found.
Researchers at the University of North Carolina at Chapel Hill have tested several mask combinations on volunteers, from a single cloth mask to double surgical masks. They found that the best filtration was wearing a mask with a full coverage, such as a bandana or cap, over a surgical mask.
“[This] leads us to the understanding that double masking is the most effective because of the improved fit it offers, not because of the additional layers, ‘lead author Emily Sickbert-Bennett wrote in an email to Insider.
The study found that a cloth mask was placed over a surgical mask. However, the same combination with the surgical mask on top did not provide any additional benefit compared to wearing a single surgical mask.
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 N95 respirators of the highest level. Some even have an electrostatic barrier designed to trap infectious particles, aeronautical virus expert Linsey Marr told Insider earlier.
But surgical masks may not fit, compared to lap options. The layer of a cloth mask on top combines the superior filtration of a surgical mask with a better fit.
If double masking sounds uncomfortable, there are other ways to make a surgical mask fit better. In a double masking CDC study, the knots of the ends of a surgical mask and the material were glued so that it was wrapped more snugly around the wearer’s face, and this almost doubled.
Other scientists have suggested that a mask brace be used to make a single surgical mask stick better to the face.
Double masking is very effective – if everyone does it
Both the CDC study and recent research on Chapel Hill found that wearing a mask works best when both people wearing interactions wear well-fitted masks.
“The best form of double masking is when you and the person you are interacting with are both wearing a mask,” Sickbert-Bennett said.
The CDC study concluded that this universal masking approach could achieve a 95% reduction in infectious particles, regardless of which well-suited option people choose.