Photo: Engin Akyurt/Unsplash

A Simon Fraser University study looked at the effectiveness of nine different types of masks typically used by professionals to filter particles from the air.

If you’re going to wear a mask, it’s best to get it fitted properly to realize its maximum safety benefits, according to a Simon Fraser University study.

Sherri Ferguson, the director of SFU’s environmental medicine and physiology unit, said the N95 mask commonly used by health-care workers can only do its job of filtering 95 per cent of particulates in the air if it fit tightly against the user’s face.

“If you can’t get a proper seal on a mask, there’s not much point in using one,” she said, adding people wearing an N95 mask should conduct a seal test each time they put one on.

Ferguson studied the effectiveness of nine types of masks by comparing the particle count in the mask with the particles in the ambient air. She also examined the impact of facial hair.

Ferguson found full-face respirator masks attached to a self-contained breathing apparatus, like those worn by firefighters, offer the most protection, filtering 98 per cent of particles whether or not the wearer has facial hair.

Ferguson said that could have significance as it could open career choices to some people whose culture requires them to retain facial hair, although, she added, further long-term studies in a variety of workplace conditions would be needed to make her findings definitive.

Ferguson said the presence of facial hair also didn’t affect the function of the N95 mask, as long as it’s properly fitted.