The colored top layer of fabric is made of medical-grade spunbond polypropylene, which is a resin polymer heat-bonded into a weblike structure.Ī 2020 study found surgical masks were about 50% effective at protecting the wearer from other people's aerosols and between 60% and 70% effective at protecting others.īut put a surgical mask under a cloth mask and you get "over 91% removal efficiency for particles," said Joseph Allen, an associate professor at the Harvard T.H. Surgical masks, also called medical-grade masks, are made of three layers of nonwoven fabric typically made from plastic. Mask wearing today: A single-layer mask isn't really effective in blocking aerosols, studies show, and even homemade two- and three-ply fabric masks are only partially protective, somewhere in the 50% to 60% range of effectiveness. "Masks should have never become a dividing line in our country," Hahn said on CNN's "COVID WAR – The Pandemic Doctors Speak Out."
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