Researchers looking at innovative ways to sterilize single-use masks

Researchers at Ottawa's children's hospital are looking for ways to safely decontaminate the N95 masks used by physicians and other staff to protect them from COVID-19.

Medical student Shira Gertsman, along with Dr. Dayre McNally and otherCHEOresearchers, have been reviewing thousands of studies into the decontamination of used medical masks.

"In a pandemic situation where we really have no idea how this is going to go, we need to be prepared for the worst-case scenario," Gertsman said.

CHEO says it hasn't resorted to reusing masksyet, but it is asking staff not to dispose of them.The hospital wants to have a system in place should thesupply run out, as provincial officials have warned they soon could.

• Ottawa Hospital rationing surgical masks to avoid shortage
• Toronto doctor sounds alarm about medical mask shortage amid fears of COVID-19
• Manitoba researchers say they may have found a way to safely reuse N95 masks amid COVID-19 crisis

Gertsman and the CHEO team released research on Friday into heat-based decontamination of masks.

"They actually do in many of these studies use regular Panasonic microwaves," she said.

With the mask wetted down and stripped of any metal, nuking it on high for about oneminute seems to kill all viruses. However, researchers discovered that process can also destroy the masks themselves, which aren't designed for multiple uses.

Last week, she and her peersshared findings on the virus-killing power of UV light.

Shewarns against trying it at home and not in the controlled setting of a laboratory.

Rice cookers, Instant Pot

There has been promising research from the United Statesinto the use of rice cookers and even the invented-in-Ottawa Instant Pot to safely sterilizemedical masks.

Every hospital already has an autoclave, a disinfecting tool a bit like apressure cooker, butresearch from a Dakota State Universitylab showed the Instant Pot may work even better.

The researchersconcluded the cooking devicewas able to kill the geobacillus spore, thebacteria used to test commercial autoclaves because of its uniquely high heat resistance.

But there are limits to the Instant Pot's effectiveness. The problem, just as Gertsman found, is that the super-heated steamychaos inside the kitchen appliance will shred most masks that were intended to be discarded after a single use.

Because of the urgency around COVID-19, the CHEO researchis being published more quickly than normal so that other institutions maybenefit.

Next week, Gerstman and her colleagues will study the chemical decontamination of masks, one more potential option for front-line health-care workers who may soon run out of the vital personal protective equipment.