Skip to Content

Why Cotton Masks Are Safer Masks

FRIDAY, March 12, 2021 -- Cotton masks provide better protection against the new coronavirus than those made with synthetic fabrics, researchers say.

In a new study, investigators tested different mask fabrics under conditions that mimic the humidity of a person's breath in order to assess how the fabrics perform in actual use.

Under humid conditions, filtration efficiency (a measure of how well a material captures particles) increased by an average 33% in cotton fabrics, according to the study published March 8 in the journal ACS Applied Nano Materials. That's because cotton is hydrophilic, meaning it attracts water. By absorbing small amounts of exhaled water in a person's breath, cotton fibers create a moist environment inside the fabric. That makes them more efficient filters compared to masks made of synthetic fibers.

In general, synthetic fabrics performed poorly in comparison to cotton, and their performance did not improve with humidity. Material used in medical masks was about as effective as cotton, but did not improve with humidity, the researchers said.

A previous study by the same team at the National Institute of Standards and Technology (NIST) and the Smithsonian's Museum Conservation Institute found that dual-layer masks made of tightly woven cotton fabrics with a raised nap, such as flannel, are particularly effective at filtering breath.

That study was conducted under relatively dry conditions in the lab.

"Cotton fabrics are still a great choice," said Christopher Zangmeister, a research scientist at NIST, in Gaithersburg, Md. "But this new study shows that cotton fabrics actually perform better in masks than we thought."

While the researchers found that humidity doesn't make it harder to breathe through fabric masks, breathing may become difficult if fabric masks get wet in other ways. They should be changed if they get wet due to weather.

The findings offer useful information for people who wear masks, as well as for scientists working to improve masks and measure their performance, the study authors said in an NIST news release.

"To understand how these materials perform in the real world, we need to study them under realistic conditions," Zangmeister said.

© 2021 HealthDay. All rights reserved.

Read this next

Americans Still Avoiding ERs in Pandemic, But Uptick Seen in Mental Health Crises

FRIDAY, April 16, 2021 -- While ER visits have stayed below normal levels as the coronavirus pandemic continues, the number of people showing up in the emergency department with...

AHA News: Could the Pandemic Help Boost Diversity in Clinical Trials?

FRIDAY, April 16, 2021 (American Heart Association News) -- The pandemic has exposed troubling inequities in the United States that have left Black and Hispanic people at higher...

U.S. Marines Study Finds Getting COVID Won't Protect Young People From Reinfection

FRIDAY, April 16, 2021 -- Young adults, take note: A new study finds that even if you have suffered a bout of COVID-19, it is not a guarantee against a second...

More News Resources

Subscribe to our Newsletter

Whatever your topic of interest, subscribe to our newsletters to get the best of in your inbox.