FDA rolls back N95 mask reuse to 4 decontamination cycles

The FDA has rolled back its emergency authorizations for N95 respirator decontamination systems, cutting down the number of times the agency said each mask could be safely reused.

During the early stages of the pandemic, when supplies of personal protective equipment and N95 filters were at a minimum, the FDA allowed masks to be reprocessed up to 20 times with certain hardware. 

Systems produced by Battelle, Steris, Stryker and Advanced Sterilization Products kill viruses and bacteria by gassing them with hydrogen peroxide vapor in devices ranging from the refrigerator-sized to walk-in shipping containers.

Now, the FDA is reissuing 10 of its earliest authorizations from the past year, limiting each mask processed to a maximum of four decontaminations.

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The agency said a review of real-world use and other studies suggested higher numbers of cycles could cause the N95 masks to fail, such as by degrading their filters or warping their structure and preventing a tight fit. Masks should still be labeled and only worn by the same user after each round.

The reissued green lights cover devices from the four aforementioned companies plus those developed by Sterilucent, Technical Safety Services, Duke University and Michigan State University. Certain systems were also no longer authorized to decontaminate respirators treated with antimicrobial or antiviral agents.

Last summer, the FDA revoked its authorizations for the decontamination and reuse of N95 and KN95 masks made in China as well as any respirators equipped with exhalation valves.