Why do masks work to prevent people from spreading the coronavirus?

In April 2020, the Centers for Disease Control updated its recommendation that all Americans should wear cloth facemasks in public.

Unlike traditional mask applications that are designed to keep from inhaling dangerous particles such as when a construction worker wears a mask to keep out dust, fighting the spread of COVID with masks is about preventing people from exhaling virus “particles and potentially infecting others.”

Here’s how it works:

• Many infected people feel fine, then go into public places and spread the disease. They emit virus particles when talking or even breathing.
• Scientists now agree that the coronavirus is at its most contagious in the few days before symptoms (dry cough and fever) first appear.
• You can catch COVID-19 when these virus particles enter through your nose, mouth, or eyes.
• The virus particles are inside small droplets that come from the mouth. These droplets are too small to see. The droplets evaporate and become much smaller very quickly. It’s harder to stop them with a mask after they’ve evaporated. That harms others wearing masks, such as grocery workers and bus drivers.
• The best way to stop the infected droplets is to catch them in a fabric mask that covers someone’s mouth.
• Research suggests that if you do inhale some virus particles, the fewer you inhale the better your chance of only getting a mild illness.

Most importantly, if every American wears cloth face masks it will also help the heroic doctors and nurses working in our hospitals to care for those with COVID-19.

That’s because if we cut the viral spread, then they will have fewer COVID-19 patients.

And fewer of our healthcare heroes and their families will get infected.

The Masks Now Coalition’s volunteers make nonmedical masks that are compliant with all CDC guidelines, in addition to facemask covers for the N95 respirator. All of their patterns are freely downloadable under a Creative Commons license.

Many healthcare professionals might not know that that doctors and nurses have the discretion to use these nonmedical cloth facemasks in clinical settings if medical PPE isn’t available. This is according to recently issued FDA emergency enforcement guidance.

You can read more facts about wearing masks to stop COVID here.