Should kids be wearing N95 masks? It’s a question many parents and caregivers are asking, as Omicron causes a surge in COVID-19 cases and children in Ontario prepare to return to class.

There’s a clear hierarchy when it comes to masks, says Catherine Clase, professor of medicine and member of the Centre of Excellence in Protective Equipment and Materials at McMaster

Poorly fitting cloth masks or procedure masks, which look like medical masks but aren’t certified, are at the bottom of the list and N95s, certified by the National Institute for Occupational Safety (NIOSH), are at the top.

For people who can source and purchase these respirator masks, Clase recommends checking with the manufacturer for guidance on sizing.

“Are they giving any kind of dimensions … weights or heights? Or if they’re just saying it’s a child’s mask, then you can assume it’s smaller than an adult’s mask,” she told CBC News. “Is it going to be small enough for a five-year-old? It may not be.”

But there are other options, including a well-fitting three-layer cloth mask with a non-woven polypropylene filter layer, and medical masks that are ASTM certified, meaning they meet certain standards.

Another option is a good-fitting cloth mask over a medical or procedure mask.

“Fit is really the most important thing,” she said in an interview with CBC Radio, noting the goal is to get the best fit on small faces.

Parents and caregivers should inspect the mask on the child’s face, ensuring there’s coverage from above the nose to below the chin, Clase said. They should also look at the sides and ensure there are no gaps and no air is escaping.

“Have the child open their mouth and make sure it’s not going to come off the nose every time they yawn or open their mouth wide to talk,” she said.

With N95 masks in short supply, Clase notes any mask will offer some level of protection.

“If the thing that you have in your hand is a mask that your child likes and will wear and you can put a drugstore level procedure mask underneath that and you can get it so that it fits nicely and your child will actually wear it for an extended period, that’s a really excellent effort towards trying to keep your child safe and that way keep everyone safe,” she says.