Crossposting to my blog because I'm sure Facebook will take my rant away.
“Adding a layer of nylon stocking over the masks minimized the flow of air around the edges of the masks and improved particle filtration efficiency for all masks,” the authors wrote in the study.
The nylon outer layer was able to increase the filtering capability of homemade cloth masks to match or even exceed that of medical-grade surgical masks; however, not the in-demand N95 respirators.
The health agency recommends that masks be made of at least two layers of fabric. They will also be more beneficial if a paper towel or coffee filter is put inside a sewn-in pocket on the mask.
"When in doubt about the quality of your mask material, conduct the light test, Segal advised. Hold up your fabric to the light, and check if you can see the individual fibers in it. If you can, it's likely too thin to provide adequate protection."
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