Canada's mask guidance has changed. Here's why you might need an upgrade - CBC.ca

Now that the cold weather has hit and people are moving inside, many doctors and scientists are urging Canadians not only to resist getting complacent about wearing masks to protect against COVID-19 — but also to take a closer look at whether that cloth mask is keeping you and others as safe as possible.

"In general, while non-medical masks can help prevent the spread of COVID-19, medical masks and respirators provide better protection," the Public Health Agency of Canada (PHAC) said on its COVID-19 mask information webpage, which was updated on Nov.

The updated guidance also recommends medical masks or respirators for people "who are at risk of more severe disease or outcomes from COVID-19" and those "at higher risk of exposure to COVID-19 because of their living situation.".

Responding to a CBC News inquiry about why PHAC's recommendations have changed, the agency said in an email it was "based on the latest scientific evidence on SARS-CoV-2 virus variants of concern, increased understanding of the impacts of vaccination and immunity in the population, and new data available on mask types and their effectiveness.".

"But if you're in a closed space with lots of people, then we should be upgrading to higher-level masks, like the KN-95 masks or a respirator-type mask, which provides better fit and better filtration.".

Another important factor that's changed since the beginning of the pandemic, experts say, is the availability of medical/surgical masks and respirators. .

Experts agree any mask is better than no mask, because it will catch droplets and aerosols coming from the wearer's nose and mouth and protect others.

"Now that we understand this disease better, we know that these small aerosols are playing a bigger role; we should be moving toward … using better mask materials.".

There are three F-words to keep in mind when assessing how well a mask will protect you and others: Fit, filtration and function (also called breathability). .

The filter material in both medical/surgical masks and N-95 respirators is actually the same — but respirators contour better to a person's face, said Selvaganapathy.

A "knot and tuck" adjustment can improve the fit of disposable masks — including medical masks, the Centers for Disease Control and Prevention (CDC) advises.

When you buy a cloth mask, it does not usually tell you what the filtration is," Levitsky said. They can protect anywhere from 20 per cent to 80 per cent, she said. "So it's a big unknown." .

And some non-cloth, non-medical masks available in stores may look like medical masks — but aren't, experts say, so it's important for consumers to check the label

The ASTM has started a voluntary certification program for non-medical masks, but at this point, there aren't many certified non-medical masks available

In an effort to better curb COVID-19 transmission, some countries, like Germany and Austria, have mandated medical-grade masks and respirators instead of cloth masks in public areas