Group looks into resterilizing N95 masks in commercial ovens

EAST LANSING, Mich. (AP) — Commercial ovens can be used to resterilize N95 masks worn to protect against COVID-19, according to researchers in Michigan, which has been hit particularly hard by the coronavirus.

The method could help guard against shortages of the masks which are sought by health care workers and first responders, the Lansing State Journal reported Friday.

As of Thursday, more than 10,000 cases of COVID-19 had been confirmed in Michigan. There had been 417 deaths. The vast majority of Michigan cases have been coming from in and around Detroit.

A team from Michigan State University met last week with officials at Sparrow Hospital in Lansing to find out if the school had resources to sanitize or decontaminate protective equipment.

They built on a Stanford University study and then developed a process that uses forced, heated air in commercial ovens to decontaminate the respirator masks, MSU Extension Director Jeff Dwyer said.

More testing is needed and work is being done at the school's Food Processing and Innovation Center, he added. The masks will be collected next week from local health care providers.

The process is expected to soon be used to sterilize masks for doctors and nurses.

N95 respirator reuse is often referred to as "limited reuse," according to the federal Centers for Disease Control and Prevention. Limited reuse has been recommended and widely used as an option for conserving respirators during previous respiratory pathogen outbreaks and pandemics, the CDC said.

"This is one of those times in many of our lifetimes that we need to be open to new ideas and new ways of doing things and push for solutions," Dwyer said. "Then this becomes an instance that we believe the decontamination of N95 masks will be one of the important components of saving the lives of patients who have COVID-19 and the lives of the health care providers taking care of them."

The process involves putting masks through a heating process at a certain temperature for a certain amount of time. Masks then are bagged and they sit for at least three days before they are ready to be used again, Dwyer added.

Masks can be resterilized for use at least 20 times, according to Norman Beauchamp Jr., executive vice president for health sciences at Michigan State.

"The process we're using, we're not going to sterilize masks and then go back to cooking food," Beauchamp said. "You want to keep those processes separate. The risk is you contaminate the oven."

N95 masks are used in industrial settings as well as hospitals, and they filter out 95% of all airborne particles, including ones too tiny to be blocked by regular masks. The CDC told medical providers to use bandanas if they run out of the masks, while volunteers with sewing skills are using publicly shared patterns to bolster supplies.

Health care providers throughout the country have said the masks and other personal protective equipment is in short supply.

For most people, the coronavirus causes mild or moderate symptoms, such as fever and cough that clear up in two to three weeks. Older adults and people with existing health problems are among those particularly susceptible to more severe illness, including pneumonia.