Depending On Your Mask, Two May Be Better Than One

On February 10, the Centers for Disease Control and Prevention released data to support the effectiveness of double masking, or layering a disposable medical mask underneath a cloth mask. The study found that layering two masks reduces exposure to COVID-19 pathogens by more than 90 percent.

How to wear your mask

Mask-wearing has long been proven to be one of the most effective ways to protect one’s self from COVID-19. Double-masking is a good solution for individuals who are not healthcare workers and who do not have a 3-ply mask that has a close fit to the face.

When you wear your mask, or masks, keep in mind that

1. Breathing through multiple layers is more protective than a single layer
2. To be protective, a mask should fit closely along the contours of the face
3. Most important of all: your mask (or masks) should fully cover mouth and nose, and not gape on sides.

Why double masking works

Medical-grade masks have proven effective on their own without an additional layer, but according to the CDC, knotting them and layering “could improve the fit of these masks and reduce the receiver’s exposure to an aerosol of simulated respiratory droplet particles of the size considered most important for transmitting SARS-CoV-2." 

Dr. Maryrose Laguio-Vila, the Infectious Diseases Division Chief at Rochester General Hospital, provides the same guidance to patients and friends.

“Based on the CDC study, a single layer cloth mask on top of a medical-grade mask may be more effective in filtering out the small respiratory droplets that transmit the virus,” says Laguio-Vila. “More than 90 percent blockage of particles sounds very encouraging.”

What masks are best?

In general, the CDC recommends choosing masks that:

• Have three layers of fabric that completely cover the nose and mouth and have a close fit to the face.
• If you don't have a mask with three layers, consider double masking to ensure multiple layers. Fit the masks snugly against the sides of your face and avoid gaps. 

And hygiene is key to the effectiveness as well.

“I'd remind people to not forget to discard medical masks once they get visibly soiled or feel gross, and wash the cloth masks regularly,” says Laguio-Vila. “Finding masks with the proper fit is especially important to limit the urges to constantly touch one’s face to adjust.”

For more on masking, visit the CDC’s website.