Gregory Poland, MD, director of the Mayo Clinic’s Vaccine Research Group, told The Washington Post that holding your mask up to the light can help show you how much protection your mask is actually providing. You can use your phone’s flashlight, sunlight, or indoor lights to perform the test. If you can see through the mask when you hold it up to the light, “it’s not a mask,” Poland said. And for useful content delivered straight to your inbox, sign up for our daily newsletter. If you want to do another test to see how your mask stacks up, you can try this other quick trick that experts recommend. “You should not be able to blow out a birthday candle with a mask on,” Neysa Ernst, RN, nurse manager of the Biocontainment Unit at Johns Hopkins Medicine, told The Washington Post. This mask test has gone viral on TikTok, and for good reason: It’s a fast way to see how readily air passes through your mask. Amy Price, DPhil, a senior research scientist at Stanford University’s Anesthesia Informatics and Media Laboratory, told NPR that when blowing on a candle while wearing your mask, you want the flame to stay lit. If you’re able to blow out the candle, that could be a sign your mask doesn’t provide a strong enough barrier, and there’s too much air exchange between you and the world, Price explained. And for the latest mask news, Dr. Fauci Says the CDC May Make This Major Mask Change Soon. These tests can’t inform you for certain that your mask gives you full protection, but they are helpful in identifying masks that definitely aren’t doing enough to keep you safe. Price cautioned that the candle test isn’t infallible, and can’t account for outside variables, such as the type of candle and individual lung strength. At the same time, she feels the test is still worthwhile because it can be useful in sussing out—and then ditching—masks that aren’t working. And for more masks to avoid, This One Type of Face Mask Is “Unacceptable,” Warns the Mayo Clinic.ae0fcc31ae342fd3a1346ebb1f342fcb Abraar Karan, MD, a physician at Harvard Medical School, told NPR that “being able to blow a candle out may be some measure of how well particles can exit your mask, [but it’s] unclear to me how reliable that is as a proxy for small aerosols exiting with normal speaking or coughing.” Meanwhile, scientist and chief technology officer at mask company AM99™ Terry T.L. Au-Yeung, PhD, said the light test may be a good way to check a mask’s layers and thickness, “but letting light through has no relation to letting the virus through.” Au-Yeung warns consumers against conflating the transmission of light and the transmission of the virus. Tests aside, when buying a mask, you should seek the kinds of face coverings that are recommended by the Centers for Disease Control and Prevention (CDC), such as non-medical disposable masks, masks with multiple layers, masks with tightly woven fabric, and masks with filter pockets. And for more reasons to upgrade your mask, If You Have This Mask, Get a New One Now, Experts Say.