The Food and Drug Administration has announced new limits on the number of times N95 respirators can be cleaned and reused in certain approved decontamination systems.

The agency last week reissued emergency use authorizations to some manufacturers, allowing compatible N95 respirators to be decontaminated a maximum of four times only. Companies originally received approval for systems they claimed could successfully disinfect the masks up to 20 times (claims that at least in one case resulted in pushback by healthcare workers who found otherwise).

EUA renewals included Advanced Sterilization Products, Battelle, Sterilucent, Steris, Stryker, and Technical Safety Services, according to device industry news outlet Medical Design & Outsourcing.

Changes were made to “protect the public health or safety” following a review of evidence from adverse events and research, including studies of N95 respirator failures from simulated and real-world use, the FDA stated. A study by National Institutes of Health scientists early in the pandemic found that N95 respirators can be decontaminated effectively and maintain their function for up to three uses. 

The EUAs originally were granted in 2020 to allow the cleaning and reuse of single-use, disposable personal protective equipment to help alleviate supply shortages.