How Effective Is the Mask You’re Wearing? You May Know Soon

A CDC division is working with an industry standards group to develop filtration standards — and products that meet them will be able to carry labels saying so.

Sheila Kaplan, The New York Times: December 16, 2020


More than 100,000 varieties of face masks are currently for sale. They come in silk, cotton and synthetics; with filters and without; over-the-head and over-the-ears. They have sparkles and sunflowers; friendly greetings and insults; cartoon characters and teeny reindeer.

What they don’t have is a label that shows how well they block infectious particles, an omission that has frustrated public health officials during the coronavirus pandemic. Those experts note that there is a big range in the effectiveness of various designs, and some barely filter out particles at all.

“The most fundamental, basic question is, What is the safest mask and how do I assure that I have that, and my family members and children have that?” said Fran Phillips, who stepped down in August from her post as deputy health secretary of Maryland. “It’s so startling that we are here in this moment and we don’t have that information.”

That may change soon. A division of the Centers for Disease Control and Prevention is working to develop minimum filter efficiency standards, and labels showing which products meet them, for the vast and bewildering marketplace for masks and other face coverings.

The National Institute for Occupational Safety and Health, a division of the C.D.C. known as NIOSH, has been quietly writing guidelines with an industry standard-setting organization, ASTM International (formerly the American Society for Testing and Materials), that are expected to be made public next month.

“By having a standard in place you will be able to know what level of protection is being achieved and you’ll have a consistent way of evaluating these products,” said Maryann D’Alessandro, director of the NIOSH National Personal Protective Technology Laboratory.

Since the pandemic began, there has been little federal oversight of masks and other face coverings. Both the Food and Drug Administration and the C.D.C. have some authority over the industry. The F.D.A., which regulates medical devices, shares authority with NIOSH for oversight of N95 respirators, which are the most protective devices available. But most of the masks the general public wears are just pieces of cloth and don’t come under any regulatory oversight.

Sales of masks took off after the F.D.A. issued an emergency measure in April that said in part that the agency would not take action against companies selling them to the general public. At the same time, however, the F.D.A. also noted that these products “may or may not meet fluid barrier or filtration efficiency levels.” That warning didn’t hurt the market, and some critics now blame the F.D.A. for the poor quality of many of the products being sold.

“There were many things the F.D.A. could have done to improve the situation, especially after research started coming out about which masks worked and which didn’t,” said Diana Zuckerman, president of the National Center for Health Research, a nonprofit health policy group. “F.D.A. could have issued a guidance that masks should be fitted, at least two layers of cloth, not made of stretchy materials, etc. Instead, there was a free-for-all.”

The effectiveness of masks can range “from 0 to 80 percent, depending on material composition, number of layers and layering bonding,” said Dale Pfriem, president of Protective Equipment Consulting Services and a member of the standards development working group addressing mask guidelines.

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Read the full article here https://www.nytimes.com/2020/12/16/health/covid-masks-effectiveness.html