The CDC says your mask needs to fit properly, which means it should fit “snugly around the nose and chin with no large gaps around the sides of the face.” Leann Poston, MD, a licensed physician and health advisor for Invigor Medical, says this is because properly fitting masks are the only ones that effectively stop large droplets that could spread and infect someone. Furthermore, masks that don’t fit properly require the wearer to frequently touch their face and masks to readjust, and “touching your face can cause you to become infected and it also increases the spread of germs when you touch other objects after touching your mask,” Poston explains. And for more on the limitations of masks, If You’re Not Doing This, Your Mask Won’t Protect You, Study Says. Plastic and leather are two materials the CDC wants mask wearers to steer away from because they are hard to breathe through. “If a mask is hard to breathe through, you will breathe around it which defeats the purpose of a mask. When you cough or sneeze, the droplets will travel around the mask or drip down from the bottom surface of the mask,” Poston says. And if your plastic or leather mask is too tight to breathe around, then it will not filter your breath, but instead block airflow, which may harm your breathing. And for coronavirus symptoms to be aware of, learn The Earliest Signs You Have COVID, According to Johns Hopkins. If your mask lets light pass through when held up to a light source, then the CDC says it shouldn’t be used. Just like masks that do not fit, masks with loosely woven or knit material will allow respiratory droplets to pass through and infect the wearer, says Daniel Burnett, MD, chief executive officer for JustAir, a face mask and clear air systems company. Even worse, Burnett says, loose mesh can “break the respiratory droplets into smaller droplets that can stay airborne for a longer period of time,” which may provide a longer exposure period. And for coronavirus signs you shouldn’t ignore, This Is One of the Most “Easily Overlooked” COVID Symptoms, Experts Warn. The CDC says your mask should have at least two or three layers. Abisola Olulade, MD, a family medicine physician with Sharp Rees-Stealy Medical Group in California, says this is because they are more likely to filter out particles than masks with only one layer. Olulade says your mask should ideally have three layers: an innermost layer made of water-absorbing material, a middle filter layer, and then an outer layer that is made of water-resistant material. And for more up-to-date information, sign up for our daily newsletter.ae0fcc31ae342fd3a1346ebb1f342fcb The CDC does not recommend masks with valves or vents because, while they may make it easier to breathe, they don’t help stop the spread of COVID. Roopa Kalyanaraman Marcello, MPH, an infectious disease expert based in New York City, says these masks allow respiratory droplets to escape from the wearer, which can infect other people. In fact, some cities, counties, and most major U.S. airlines have banned these face masks. And for precautions you no longer need to take, discover The One Thing You Can Stop Doing to Avoid COVID, According to Doctors. “Scarves and other headwear such as ski masks and balaclavas used for warmth are usually made of loosely knit fabrics that are not suitable for use as masks to prevent COVID-19 transmission,” says the CDC. According to Poston, these have the same drawbacks as an improperly fitting mask in that they don’t really filter droplets and they most likely need frequent readjustment. However, you can wear these items over your mask—you just need to be wearing some type of protective mask also. And for more essential mask guidance, The FDA Issued a Warning Against This Kind of Face Mask.