How do the different types of masks work?

Surgical masks

Also called a medical mask, a surgical mask is a loose-fitting disposable mask that protects the wearer's nose and mouth from contact with droplets, splashes and sprays that may contain germs. A surgical mask also filters out large particles in the air. Surgical masks may protect others by reducing exposure to the saliva and respiratory secretions of the mask wearer.

At this time, the U.S. Food and Drug Administration has not approved any type of surgical mask specifically for protection against the coronavirus, but these masks may provide some protection when N95 masks are not available.

N95 masks

Actually a type of respirator, an N95 mask offers more protection than a surgical mask does because it can filter out both large and small particles when the wearer inhales. As the name indicates, the mask is designed to block 95% of very small particles. Some N95 masks have valves that make them easier to breathe through. With this type of mask, unfiltered air is released when the wearer exhales.

Health care providers must be trained and pass a fit test to confirm a proper seal before using an N95 respirator in the workplace. Like surgical masks, N95 masks are intended to be disposable. However, researchers are testing ways to disinfect N95 masks so they can be reused.

Some N95 masks, and even some cloth masks, have one-way valves that make them easier to breathe through. But because the valve releases unfiltered air when the wearer breathes out, this type of mask doesn't prevent the wearer from spreading the virus. For this reason, some places have banned them.

Cloth masks

A cloth mask is intended to trap droplets that are released when the wearer talks, coughs or sneezes. Asking everyone to wear cloth masks can help reduce the spread of the virus by people who have COVID-19 but don't realize it.

Cloth face coverings are most likely to reduce the spread of the COVID-19 virus when they are widely used by people in public settings. And countries that required face masks, testing, isolation and social distancing early in the pandemic have successfully slowed the spread of the virus.

While surgical and N95 masks may be in short supply and should be reserved for health care providers, cloth face coverings and masks are easy to find or make, and can be washed and reused.

Masks can be made from common materials, such as sheets made of tightly woven cotton. Instructions are easy to find online. Cloth masks should include multiple layers of fabric. The CDC website even includes directions for no-sew masks made from bandannas and T-shirts.