The surgical masks and N95 respirators health care staff wear have to meet federal standards. A lot of the types of face masks you and I buy don't have to undergo testing. But, mask manufacturers can choose to test and see how effective their face barrier is.
If you see the label, "ASTM F3502" on a face mask package or while browsing online, that means it meets a national standard for barrier face coverings.
It was evaluated for things like breathability and leakage by a global organization called the American Society for Testing and Materials, or ASTM.
The testing is voluntary.
"They at least provide the wearer some assurance that they meet a minimum level of their ability to filter particles," said Dr. Jon Meiman, the Chief Medical Officer with the Wisconsin Department of Health Services.
Doctor Meiman says the standard is helpful, although it doesn't matter much if the mask you buy doesn't fit your face well or if you simply aren't consistent with wearing it.
That's the same sentiment Dr. Mary Beth Graham has. She's the Medical Director for Infection Prevention & Control at Froedtert Hospital and the Associate Chief of the Division of Infectious Disease at the Medical College of Wisconsin.
"We are at high risk of transmission, we still have a number of people becoming positive," said Dr. Graham. "What we've said all along, many of my colleagues and I have said the mask that you wear is the best mask to have."
Echoing what the CDC recommends, Dr. Graham says if you choose a cloth mask, it should have multiple layers of a tightly woven fabric.
Dr. Graham suggests if you prefer disposable masks, if needed, you can loop or tie the ear bands on for a snug fit.
"If it's not well-fitting, it can still go out on the sides or around the mask," she said.
Both doctors agree N95 masks are the gold standard. But health care staff and other professions that require them for work have to get fit-tested for their N95 masks.
"We don't have good evidence of how well they work without having that type of a fit test. But they seem to provide, or we suspect they give a better level of protection than say something, even without this fit testing, compared to like a cloth or surgical or disposable face mask," Dr. Meiman said.
Click here to see mask manufacturers which have declared conformance to ASTM F3502-21 standards.
Jonathan Szalajda, NIOSH (National Institute for Occupational Safety and Health) National Personal Protective Technology Laboratory's Deputy Director, responded to TMJ4 News' questions about the ASTM barrier face-covering standard.
1.) TMJ4 News: What exactly is the new standard for face coverings?
Szalajda:ASTM International developed a new Barrier Face Covering standard (number F3502-21) to establish a set of uniform testing methods and performance criteria. To meet the ASTM standard, a BFC must meet certain design and performance requirements, including filtration efficiency and air flow, which must be tested by an accredited laboratory and labeled accordingly.
2.) TMJ4 News: How do consumers know what to look for? (Should there be a label on the packaging?)
Szalajda: Masks and packaging (smallest unit or package) that meet the ASTM requirements must be labeled according to the ASTM Standard. Additionally, CDC has information on its website that discusses different types of masks, and how to identify masks that are made to a standard. There is also a website that lists manufacturers that claim conformance to the ASTM standard.
3.) TMJ4 News: Are all masks currently being sold on the market undergoing this type of testing to meet this standard?
Szalajda: To meet the ASTM standard, a BFC must meet certain design and performance requirements, including filtration efficiency and air flow, which must be tested by an accredited laboratory and labeled accordingly. The development of the ASTM standard provides a consistent baseline that allows comparison of product claims in terms of filtration efficiency, breathability, re-use potential, and leakage.
4.) TMJ4 News: What if you already purchased a cloth or disposable face mask -- how do you know if it is protective?
Szalajda: CDC has a guide to masks Your Guide to Masks as well as the Types of Masks and Respirators on its website. Wearing a mask is one of the most important ways to reduce the risk of getting and spreading COVID-19. Improve the Fit and Filtration of Your Mask to Reduce the Spread of COVID-19 describes the types of masks available and strategies that can be used to better protect the wearer and the people they interact with. Wearing any type of mask correctly is better than not wearing a mask at all.