Story at a glance
- Public health experts say face masks are one of the best ways to protect against coronavirus infection.
- Many Americans are wearing cloth face coverings, rather than more-expensive and limited medical-grade masks.
- A study explored how effectively different household materials used for masks filter out particles.
Face masks have evolved since the beginning of the pandemic, when some Americans were using rubber bands and spare pieces of cloth. But cloth coverings still remain one of the most effective forms of protection against the coronavirus without a vaccine.
So what materials should you look for when shopping for face masks? A new study suggests that many household materials are actually highly effective for not only making masks but also reinforcing them. The study, published in the American Chemical Society publication, was conducted by researchers from the World Health Organization, Centers for Disease Control and Prevention, 4C Air Inc. and various universities.
WHAT YOU NEED TO KNOW ABOUT CORONAVIRUS RIGHT NOW
Nylon and polyester masks will stop about 20 percent of particles of a certain size, the study found, compared with the 30 percent filtration efficiency of medical-grade face masks. Cotton is slightly more unreliable, ranging from 5 to 20 percent filtration efficiency, but certainly more so than silk, which has about 5 percent filtration efficiency.
Another major finding of the study is that tissues and paper towels have between 10 and 20 percent filtration efficiency, suggesting that if used in conjunction with a cloth face covering, it would compound the amount of particles trapped by the mask. Some masks now come with pockets for filters, where you can easily sleep a square of tissue or paper towel.
Still, there are many variables in the transmission of infected particles, the study's authors emphasized, which suggests that these findings could vary under different circumstances. Even a medical-grade mask is ineffective if it does not properly fit your face, leaving gaps on the sides or tops.
"The testing here did not account for real-world scenarios where the leakage around the edges of the face cover may significantly impact the actual effectiveness of these coverings. Hence, having a tight seal of the cloth around the face is imperative for these results to align with real usage conditions," the authors said.
BREAKING NEWS ABOUT THE CORONAVIRUS PANDEMIC