Ottawa

Researchers looking at innovative ways to sterilize single-use masks

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

Instant Pots, rice cookers, microwaves put to the test as hospitals run low on PPE

Researchers are looking for ways to sterilize N95 masks, like the white one seen here, so they can be reused instead of thrown out. (Tyson Koschik/CBC)

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 other CHEO researchers, 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 masks yet, but it is asking staff not to dispose of them. The hospital wants to have a system in place should the supply run out, as provincial officials have warned they soon could.

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 one minute 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 peers shared findings on the virus-killing power of UV light.

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

Medical student Shira Gertsman and her colleagues combed through thousands of articles in search of peer-reviewed research on mask decontamination methods. (Submitted)

Rice cookers, Instant Pot

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

Every hospital already has an autoclave, a disinfecting tool a bit like a pressure cooker, but research from a Dakota State University lab showed the Instant Pot may work even better.

The researchers concluded the cooking device was able to kill the geobacillus spore, the bacteria 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 steamy chaos 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 research is being published more quickly than normal so that other institutions may benefit.

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.

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