N95, KN95 or KF94? How to Find the Right Covid Mask

Mr. Collins may be best known for his list of children’s masks. While there is no N95 mask for kids approved in the United States, mask makers in China and Korea have created KN95s and KF94s for children, including some with child-friendly colors and prints. Mr. Collins created a video “primer for parents” about finding a high-quality mask for kids that has more than 100,000 views.

“I had retired from mask testing,” Mr. Collins said, noting that he doesn’t receive any compensation for his work. “But I came out of retirement to do the kids video. The only place I’ve seen a list of test data is unfortunately me.”

Wirecutter, a product review site owned by The New York Times, has a guide for buying quality masks, one for buying children’s masks and a list of 12 red flags that might signal your mask is a counterfeit.

Do your research.

It’s not easy, but the C.D.C. has a few lists you can use to confirm a mask has been vetted. A note of caution: If you don’t find a particular mask, make sure you’ve looked it up the correct way, said Anne Miller, executive director of Project N95. For instance, a Gerson N95 mask won’t be found under the letter “G.” It’s listed under “L” because the full name of the company that makes it is Louis M. Gerson.

For N95 masks, go to the C.D.C.’s alphabetical list of NIOSH-approved respirators. You can also look up the TC approval number using the certified equipment list.

For KN95 masks, you can use two checklists from the Food and Drug Administration. The F.D.A. created these lists early in the pandemic, when the agency issued an emergency use authorization that allowed health workers to use KN95 masks because of a shortage of N95s. Now that the N95 supply is adequate, the agency has revoked the authorization for these workers, but other people can still use KN95s. While the list is now a bit outdated, finding your mask on it adds reassurance that it’s less likely to be counterfeit — with the caveat that there’s no longer official U.S. oversight for any of these firms. You’ll need to scroll down to find the list and search box.

Use this F.D.A. list to find KN95 masks made in China, and this list for KN95 masks made in other countries.

Jin Yu Young contributed to this report.