MSU seeks FDA approval for process to decontaminate, reuse N95 masks

Melissa Nann Burke
The Detroit News

Michigan State University and Lansing’s Sparrow Health System have developed a new way to sanitize N95 respirator masks so they may be recycled for medical personnel amid the coronavirus pandemic. 

If approved by federal regulators, the process could be replicated across the country using commercial-grade ovens and helping to relieve the shortage of N95 masks. 

MSU Extension this week submitted an emergency application to the Food and Drug Administration seeking approval of its protocol, which includes heating the N95s to a certain temperature to kill off contaminants, including the virus that causes COVID-19.

The proposal also details a tracking system to ensure the sanitized mask is returned to the same medical or health care worker that previously used it to further reduce the risk of exposure. 

A worker removes a dirty N95 mask from packaging before beginning the decontamination process at MSU Extension's Food Processing and Innovation Center.

“Once we get approval from the FDA, then we can go into full production at our facility decontaminating masks 24-7," said Jeffrey W. Dwyer, director of the MSU Extension.  

"What makes our protocol somewhat unique is this is a protocol that can be adapted and adopted by others to decontaminate masks in their communities. ... There are thousands of these types of commercial ovens across the United States."

The spiral oven at MSU Extension's Food Processing and Innovation Center more typically used to bake large quantities of cookies or muffins can decontaminate a few hundred masks an hour for medical personnel, Dwyer said. 

The ability to sanitize and reuse the masks could help hospitals and states struggling to restock supplies of N95 masks, which are in high demand globally amid the pandemic because they filter out 95% of small particles including viruses.  

Hard-hit hospitals in southeast Michigan have begun rationing N95 masks, and the Michigan Health and Hospital Association said this week that some hospitals have as little as three days' worth supply of protective health gear for employees treating COVID-19 patients. 

With the U.S. national stockpile of emergency supplies depleted, Michigan officials, lawmakers and hospital systems went hunting for new sources of N95s. They encountered supply-chain delays and bottlenecks in China, where many of the masks are manufactured.

"We actually had shipments canceled in China because someone showed up there with cash and said I’ll pay a higher price," said James F. Dover, CEO of president of Sparrow Health System. 

MSU has developed a process for decontaminating N95 respirator masks using a commercial oven like this spiral oven.

But the N95 mask is the "gold standard" for protecting medical staff from viruses, he said. Using 1,500 N95 masks a day, the 22,000 masks currently on hand at Sparrow will last 29 days.

"Consequently, we have to be constantly reordering and reordering, but orders are being canceled. We got down to four days' supply at one point," Dover said. 

"We’re not in a situation like in New York where they were being asked to use a mask for five days. None of that here. But we did not want to get into that situation."

So Sparrow last month raised the idea of adapting an older technology of reusing masks that had been explored by Stanford researchers during the SARS epidemic, Dover said. 

"Borne out of necessity, we took it over to Michigan State. We said, hey, you guys have big ovens. Is this something you can do for us?" Dover said. 

The proposal came together in a week and a half. Under the new protocol, a hospital employee would label his or her mask with their name and floor. The hospital collects the masks and checks them for holes, tears and other physical damage, discarding the worst. 

At MSU's facility, the masks would be put through the spiral oven in batches for 45 minutes and emerge on the other side, where they would be sealed inside an individual plastic bag and placed into a box, Dwyer said. 

The masks would sit for three days as a back stop in case any COVID-19 virus survived the oven before being returned to the hospital unit and individual employee for whom they were fitted, Dwyer said. 

A worker prepares to place a dirty N95 mask into the spiral oven for decontamination.

Testing validated that the masks were indeed decontaminated, Dover said. The protocol would allow the masks to be reused up to 20 times, rather than being thrown away after one use.

"This moves us from having 29 days' supply on hand to 400 days," he said. "Then we can tell the international gangsters of the N95 supply chain that we don’t need them."

U.S. Rep. Elissa Slotkin said she knew MSU's decontamination protocol could be a game changer when she heard about it. 

"I called the president of MSU, and I said your work has become so much more important in the last 96 hours," said Slotkin, whose district includes the university. 

"I need you to have everyone in over the weekend. I need you to be working double time. I need that application into the FDA. And they did it."

Slotkin, a Holly Democrat, enlisted the help of Republican U.S. Rep. Fred Upton of St. Joseph, former chairman of the House Energy and Commerce Committee, to call high-level FDA officials' attention to the emergency application in a bid to expedite the approval process. 

A worker prepares to place a dirty N95 mask into the spiral oven for decontamination at MSU Extension's Food Processing and Innovation Center.

Upton said he spoke Thursday with the head of the agency's device division, Jeffrey Shuren, who said a reviewer had already been assigned to the request. 

"He's well aware of the application. He thought it looked very promising," said Upton, who previously worked with Shuren. 

He said MSU's application is among 42 the FDA is looking at concerning the sterilization of personal protective equipment. Upton hopes the application can be approved within a couple days. 

Emergency use authorization from the FDA would give hospitals and medical providers the confidence of knowing it's safe to reuse a mask that's gone through MSU's decontamination protocol while maintaining the mask's structural integrity, Slotkin said.

"So they can go home and talk to their families feeling like they were protected. We owe them that," she said. "And we made sure that no one was taking a patent. That this would be publicly available information."

Sparrow, which operates six hospitals, is sending 800 N95 masks to be decontaminated at MSU this week, Dover said. 

Currently, the Centers for Disease Control and Prevention recommends using N95s when going into a COVID-19 patient’s room, but Dover wants all Sparrow staff working in all hospital units to be wearing N95s whether they are seeing a COVID patient or not.

They didn’t have enough in stock to go around before, but reprocessing the masks will allow staffers to wear them for their entire shift, he said. 

Some other hospitals are experimenting with decontaminating N95 masks with a vaporized hydrogen peroxide, but there's questions about how easy it would be to scale up that process, Dwyer said. 

Boxes labeled 'infectious waste' filled with N95 respirator masks from Sparrow Health System arrive at MSU Extension's Food Processing and Innovation Center to be decontaminated.

"The VHP process requires three things that aren’t on every street corner: specialized equipment, a sealed-off place to do it, and people who are trained in specific handling of chemicals," he said. 

By contrast, across the country there are thousands of the types of commercial ovens that MSU is using for its protocol. 

Slotkin said she's already working to identify similar-style commercial ovens in Michigan, including at food companies like Kellogg's and inside hospital cafeterias.

"So that when and if the FDA approves this, it can be scaled, and suddenly we can control the supply — or at least part of the supply of masks for our own people," she said.