Time to Upgrade Your Mask?

Is it time to upgrade your mask?

By now most of us have settled on a preferred cloth mask to protect ourselves and others from coronavirus. But new research shows that a few simple upgrades in fabric, filters and fit are likely to provide even more protection.

Linsey Marr, professor of civil and environmental engineering at Virginia Tech and one of the world’s leading aerosol scientists, led the research, which tested 11 different mask materials. The findings confirmed what other labs have found: You don’t need a gold-standard N95 medical mask to stay safe from coronavirus. The right cloth mask, properly fitted, does a good job of filtering viral particles of the size most likely to cause infection.

But Dr. Marr and her colleagues found that small improvements to your mask can go a long way toward improving how well the mask protects you and others from potential infectious particles. They found that:

Three layers are better than two. The best mask has two tightly woven layers of outer material with a filter material sandwiched in the middle, Dr. Marr said. You can use surgical mask material or even a piece of a vacuum bag as a filter between two pieces of fabric. Coffee filters are an option, but can be less breathable. If you like your two-layer mask, you can just wear it over a surgical mask when you want added protection. A well-fitting fabric mask with a third filter layer can stop 74 to 90 percent of risky particles, the researchers found. ...

A well-fitted mask protects the wearer. Dr. Marr and her colleagues tested cloth masks for how well they protected others (outward protection) as well as the wearer (inward protection). Although masks are most efficient at filtering outgoing germs, they do stop incoming germs at nearly the same rate in most cases, the researchers found. Masks that did a poor job protecting the wearer were those made of stiffer materials and those worn loosely and with gaps around the edges. ...