By Austen Hufford 

What makes an N95 different from other face masks?

N95 masks are so called because they are a U.S. standard that requires masks to be able to filter out at least 95% of very small particles, including droplets containing the coronavirus. They are typically worn by medical workers as well as employees at factories working with paint or industrial chemicals, for instance.

Surgical masks and simpler cloth masks, by comparison, are largely intended to prevent the wearer from spreading germs and are simpler to put on and wear. Surgical masks don't create as tight a seal to the face as N95 masks.

Who makes quality N95 masks?

The National Institute for Occupational Safety and Health, the main U.S. regulator of N95 masks, has certified many companies domestically and abroad to make them, including industry leaders like 3M Co. and Honeywell International Inc.

Are there enough N95 masks to go around now?

No. The demand for N95 masks outstrips current supply significantly.

Mask makers in the U.S. and around the world have been increasing production, but so far, demand remains even higher. U.S. authorities want available N95 masks to be used by front-line workers confronting the pandemic and recommend the general public wear cloth masks instead.

How do front-line workers know whether their N95 masks are genuine and of sufficient quality?

Approved N95 masks are listed on Niosh's website. Such masks should have "NIOSH" and "N95" printed on their filter material. Genuine N95 masks also have elastic bands that stretch behind the head rather than loops that attach at the ears.

Hospital workers typically undergo a 20-minute-long "fit test" whenever they start using a new type of mask. Workers can also do a shorter daily seal check to see if their mask is fitting properly. Niosh has a webpage where officials post photos of fraudulent masks they find.

Can the lifespan of a N95 mask be extended?

The Centers for Disease Control and Prevention has issued guidance on how to best extend a limited supply of N95 masks, which can be found online.

The CDC says that ideally a new N95 should be used for every procedure. But the CDC acknowledges that due to current shortages, health workers may need to reuse masks and reduce mask use.

The CDC says health-care workers can wear one mask each day and then store the used mask in a paper bag. After five days, they can reuse that mask, because viruses like the new coronavirus are expected to degrade during that time.

What about decontamination systems?

Given the current mask shortage, the Food and Drug Administration has given emergency approval to about eight systems that are designed to decontaminate used masks. The most prominent, made by Battelle Memorial Institute, has sent about 700,000 masks through its system.

Some nurse and front-line responder groups have expressed concern about these systems. The FDA said Battelle has forwarded about 100 concerns about its system, reporting issues including torn straps, fit concerns or dirty masks. Battelle has said its system works and is safe.

What are KN95 masks?

KN95 is a mask standard used in China that is similar to the N95 standard. There have been instances of low-quality masks that claimed to follow the N95, KN95 or other standards but then failed quality checks. Niosh is releasing test results of imported masks.

The FDA issued emergency guidance in early April allowing for the use of masks made by certain manufacturers in China that hadn't received Niosh approval.

In May, however, the FDA removed many manufacturers from the list due to quality concerns.

Write to Austen Hufford at austen.hufford@wsj.com

(END) Dow Jones Newswires

June 01, 2020 12:06 ET (16:06 GMT)

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