- The World Health Organization and the Centers for Disease Control and Prevention recommend cloth face masks for the general public.
- These masks are not as protective as surgical masks or N95 respirators, but some are highly efficient at filtering viral particles.
- This is how scientists have classified mask materials so far, from most protective to least protective.
- Visit the Business Insider home page for more stories.
The science is clear: face masks can prevent coronavirus transmission and save lives.
A preliminary analysis of 194 countries found that places where masks were not recommended saw a weekly 55% increase in coronavirus deaths per capita after their first case was reported, compared to 7% in countries with crops or guidelines that support the use of masks. A model from the University of Washington predicted that the United States could prevent at least 45,000 coronavirus deaths in November if 95% of the population wore masks in public.
But not all masks confer equal levels of protection.
The ideal face mask blocks large respiratory drops from coughing or sneezing, the primary method by which people transmit the coronavirus to others, along with smaller particles in the air, called aerosols, that occur when people speak or exhale.
The World Health Organization recommends medical masks for healthcare workers, the elderly, people with underlying health conditions, and people who have tested positive for the coronavirus or show symptoms. Healthy people who don’t fall into these categories should wear a cloth mask, according to the WHO. The Centers for Disease Control and Prevention also recommends cloth masks for the general public.
But even cloth masks vary, as certain types are more porous than others.
“It depends on the quality,” Dr. Ramzi Asfour, an infectious disease physician in Marin County, California, told Business Insider. “If you’re making a fabric mask with 600-thread count Egyptian cotton sheets, that’s different from doing it with a cheap T-shirt that isn’t very finely woven.”
In recent months, scientists have been evaluating the most effective mask materials to trap the coronavirus. Here are their results so far, from highest to lowest protection.
