THURSDAY, Sept. 16, 2021 (HealthDay News) -- If you're making your own face mask to protect against COVID-19, three layers of cotton towel fabric are best, researchers from India report.
That recommendation comes after testing how best to block cough droplets moving at different rates, from mild to severe.
"Our results show cotton, towel-based fabrics were most effective among the considered fabrics and must be stitched together as multiple layers for making homemade face masks," said researcher Saptarshi Basu, from the Indian Institute of Science in Bengaluru.
"A three- or more-layered homemade mask is recommended since it can suppress aerosolization significantly," Basu said in a news release from the American Institute of Physics. The report was published online Sept. 14 in the institute's journal Physics of Fluids.
Such masks remain effective even after 70 washings, the researchers said.
For the study, the team sprayed single layers of summer stole, handkerchief, cotton towel and surgical masks. They used high-speed imaging to quantify the threshold for penetration and amount of droplet penetration at different velocities.
Overall, the researchers confirmed that N95 and surgical masks are most effective. But when those aren't available, cotton towel fabric can be layered and stitched into an effective makeshift face mask, they said.
For more on face masks, see the U.S. Centers for Disease Control and Prevention.
SOURCE: American Institute of Physics, news release, Sept. 14, 2021