A single face mask can no longer suffice; recent research from the Centers for Disease Control and Prevention (CDC) indicates that if your single mask does not fit properly or has multiple layers, you can use two. Wearing cloth face coverings over surgical masks, as well as tying knots on ear loops and tucking the sides of disposable masks, provides greater protection against COVID-19 than wearing a fabric covering or a poorly-fitted medical mask alone, according to CDC research released on February 10.
For months, we’ve known that face masks shield both the wearer and those around them, and that several layers of tightly woven cloth provide better protection than flimsier, non-breathable coverings. Face masks operate by preventing large respiratory droplets from spreading the virus when people cough or sneeze. They can also act as a buffer against smaller aerosols, which are a less popular but still possible mode of transmission for the virus.
According to the CDC, although a single surgical mask on an infected person prevents about 42% of infectious particles from reaching a healthy person and a cloth mask prevents more than 44%, wearing a cloth mask over a surgical mask prevents 92.5 percent of cough particles from reaching a healthy person. This seems to be due to the fact that the surgical mask effectively filters out virus particles, while the cloth mask will enhance the fit.
However, putting on a lot of masks has its drawbacks. If you’re in a position where other people have been hanging out and potentially distributing viral droplets, you may be tempted to fiddle with the additional mask. You can come into contact with a contaminated surface and then transfer virus particles to your mask. And while a second (or third) mask will create a more effective barrier for outgoing and incoming particles, it will also make it harder to breathe in the air you need.
So, if you want to try something new, there are a few things to consider. While most disposable masks on the market are not medical-grade, they are still made of polypropylene, a nonwoven fabric that repels viral particles electrostatically. That means they continue to get high marks for virus protection. When worn alone, their loose fit leaves too many gaps from which viral particles will enter and exit.
A cloth mask with a filter that fits snugly will block 74 to 90% of infectious particles. It’s important to have a nonwoven filter because it can help trap tiny aerosols that slip past the weave in even the most tightly woven fabrics. A special HEPA filter designed to fit into a mask with a pocket can be purchased, or a vacuum bag can be cut up. Vacuum bags have been found to be one of the best materials for capturing tiny particles in many research studies on mask effectiveness.
How do you tell if you’re a good match? Warm air should enter the mask from the front, and you should be able to see the mask material move in and out with each breath. There should also be no holes. Even the tiniest gaps in the air will allow respiratory droplets to enter your nose and mouth.
You may also use the CDC-recommended “knot and tuck” approach to secure a loose surgical mask. It involves tying a knot at the point where the ear loops meet the mask’s edge, as well as folding and tucking any excess material under the mask’s edges. This approach was shown to significantly improve safety against virus exposure and transmission in laboratory research.
Surgical and N95 masks aren’t always inexpensive, and because they’re disposable, the expense may easily add up. If you choose a cloth mask, look for one with several layers of fabric and a nose wire, which is a metal strip running along the top of the mask. To improve the fit and avoid air leaks, the nose wire may be twisted around your nose.
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