The double mask combination blocked 92.5% of the cough particles.
Making sure a mask fits snugly on the face and use of two masks is likely to significantly reduce a person’s exposure to the coronavirus, laboratory experiments described by U.S. health officials on Wednesday showed. The U.S. Centers of Disease Control and Prevention (CDC) in January conducted experiments to see how well wearing a cloth mask over a three-ply medical procedure mask, and knotting the ear loops of a surgical mask and then tucking the excess material close to the face, protects against COVID-19. They found that both these methods helped reduce the exposure to potentially infected aerosols by more than 90% in laboratory simulations. The data also showed that wearing a mask helped reduce exposure to aerosol particles that were the size of droplets that spread COVID-19, when compared to wearing no mask at all.
