4 Million N95 Masks Can Be Decontaminated a Day, Thanks To FDA Emergency Use Ruling

April 13, 2020

There are nearly 10,000 STERRAD Sterilization machines in about 6,300 US hospitals, and the reprocessing times vary from 55 minutes, to 28 minutes, and 24 minutes, depending on which particular STERRAD machine is being used.

A second emergency use authorization (EUA) that officials hope will replenish supplies of desperately needed N95 masks has been issued by the US Food and Drug Administration (FDA). The FDA made headlines last Friday with is first EUA, granted to STERIS Corporation whose sterilization process can decontaminate about 750,000 N95 masks a day. Yesterday, the FDA granted the EUA to Advanced Sterilization Products (ASP), which could lead to the sterilization of as many as 4 million N95 respirators a day. 

According to the FDA, ASP’s STERRAD Sterilization Cycles uses vaporized hydrogen peroxide gas plasma sterilization. The system is already in place. There are nearly 10,000 STERRAD Sterilization machines in about 6,300 US hospitals, and the reprocessing times vary from 55 minutes, to 28 minutes, and 24 minutes, depending on which particular STERRAD machine is being used. Each can reprocess about 480 respirators a day. 

The EUAs take their cue from research by Duke University investigators. Scott Alderman, associate director of Duke’s regional biocontainment laboratory, said in a press release on March 26: “This is a decontamination technology and method we’ve used for years in our biocontainment laboratory.

Matthew Stiegel, Ph.D., director of Duke’s occupational and environmental safety office, added: “We had never considered needing it for something like face masks. But we’ve now proven that it works and will begin using the technology immediately in all three Duke Health hospitals.”

It’s been known that hydrogen peroxide can decontaminate N95 masks since 2016, but that was never followed by widespread adaptation, according to Duke officials. The earlier studies did not include fit testing after cleaning, which would determine if the masks worked for different individuals, an important efficacy element. Duke research tested for that. 

“The decontamination process requires specialized equipment that vaporizes the hydrogen peroxide, and a closed facility where the masks can be exposed to the vapor,” Duke said in the press release. “No toxic byproducts result, because hydrogen peroxide breaks down to water.”