N95 and KN95 Masks Are Held to Different Standards, so You Need to Be Careful When Choosing One Prevention 2/2/2021 Courtney Linder Due to new, more contagious variants of COVID-19 emerging in the U.S., medical experts are recommending the use of N95 or KN95 masks. These masks can filter a higher percentage of particles in the air than surgical masks or homemade cloth face coverings. N95 and KN95 masks are held to different standards, though, so you need to be careful in deciding which is right for you. You've probably been wearing a mask when out in public for most of the past year, but are you still wearing the right one? With new variants of COVID-19 emerging in the U.S., medical professionals are urging the public to go beyond cloth masks, surgical masks, and double masks. Instead, they say, you should opt for a higher-filtration mask like an N95 or KN95.