According to a
2013 study in the journal Disaster Medicine and Public Health Preparedness, fabric masks that fit snugly on the face provided three times less protection than surgical masks. “We found they are not as good as surgical masks,” Anna Davies, the lead study author, told BuzzFeed News.
Davies and her colleagues found a surgical mask had about a 90% filtration efficiency for very small particles (around 2 microns). The next best materials found at home at blocking particles were vacuum cleaner bags (about 86% filtration efficiency) and tea towels (about 72% filtration efficiency), but they would be so difficult to breathe out of that they wouldn’t be suitable for a mask. Meanwhile, a cotton mix material had about 70% filtration efficiency compared to roughly 57% for a pillowcase, about 62% for linen, about 54% for silk, nearly 51% for a 100% cotton T-shirt, and nearly 49% for a scarf.