As new, more contagious variants of the new coronavirus spread around the world, public health officials advise us to upgrade our mask protection. One of the easiest ways to do this is to wear two masks at the same time. Here are answers to common questions about the do’s and don’ts of double masking.
Why do I have to double?
New variants of the coronavirus are more contagious. It could be that an infected person is shedding larger amounts of virus, or it is taking fewer virus particles to make you sick. Either way, a more infectious virus means we have to wear masks that work better to catch infectious particles. Double masking can improve the fit of your mask by closing gaps on the sides, and it creates several layers of protection against drops coming in or out.
Can I wear two surgical masks?
It is not recommended to wear two disposable surgical masks. A standard surgical mask is a blue, rectangular mask made of paper-like material. Although surgical masks are excellent filters against viral drops, they tend to fit poorly, leaving gaps on the sides, which reduces their effectiveness. Dressing two at the same time does not solve the appropriate problem. Adding a cloth mask on top of a surgical mask helps to close the gaps and make them fit better. The team at Wirecutter, owned by The New York Times, has help choosing a cloth mask. (The mask in the video is the Graf Lantz Zenbu Organic Cotton Face Mask.)
Do I need to double a mask with an N95 or KN95?
The N95 mask is the gold standard for medical masks, and the KN95, made in China, is similar. If worn correctly, both masks will filter 95 percent of the hardest particles. If you have access to a real N95 or KN95 and it fits well, you do not need to double the mask. The problem is that the N95 and KN95 masks are still difficult to obtain, and that the supply chain is full of counterfeit. Although the Centers for Disease Control & Prevention does not recommend double masking with an N95 or KN95, you need to make sure you have the right thing. If you are unsure, or it does not fit well, it may help to cover it with a cloth mask. (Another extremely effective medical mask is the KF94, manufactured in Korea. Counterfeiting is usually not a problem with KF94s, and if it suits you well, you do not need to double the mask.)
If I have a double mask, why should I fasten my surgical mask?
The best way to double mask is to wear a surgical mask as the first layer and cover it with a cloth mask. It is not necessary to wear your surgical mask, but if it fits badly, you can tie the rest knots and insert the corners to improve the filter efficiency by as much as 20 percent. For a longer demonstration of adjusting the fit of your surgical mask, watch this video from UNC Health.