Canada
A tight-fitting mask only protects you if no air leaks in around the edges. If air gets in at the side, it doesn’t go through the filter. And then the filter can be as good as you like, it won’t help.
British Columbia in Canada is updating its rules on exactly this. The changes start on 6 November 2026. WorkSafeBC, the province’s workplace safety authority, ran a public consultation from November 2025, and its board approved the changes in July.
Clearer rules, not new ones
WorkSafeBC is clear about one thing: there are no new duties for employers or workers. The update rewrites the rules so they’re easier to understand and use the same words throughout.
The main change is a new term: “tight-fitting respirator”. That means any mask that only works if it seals properly against the face, like a disposable dust mask or a rubber half or full mask. These masks aren’t new, of course. The rules just didn’t have one clear name for them until now.
And the rules now say plainly: employers must make sure nothing gets in the way of the seal.
What can break the seal
According to WorkSafeBC, anything that comes between the edge of the mask and the skin counts as an interference and can reduce the protection. Its list:
- hair
- jewellery
- clothing and personal items
- other PPE, for example the arms of safety glasses
A fit test isn’t a one-off
A fit test checks that a particular mask, in a particular size, fits a particular person’s face. The new rules say the conditions that let the worker pass the fit test must stay the same every time the mask is worn. In practice:
- Workers wear and adjust the mask exactly the way they did in the fit test.
- If someone’s face changes, for example after a big weight change, dental work or a facial injury, they need to be checked again, and may need a new fit test.
What employers have to do
WorkSafeBC lists these procedures:
- A seal check before every use. The quick check workers do themselves each time they put the mask on, for example covering the filters, breathing in gently and feeling the mask pull in slightly against the face.
- Inspection of the mask before use.
- Supervisors check that workers wear their masks correctly and keep the seal conditions while they work.
- Ask the worker before choosing a mask, and make sure it suits the person, the job and the conditions.
- Offer an alternative if a good seal isn’t possible. WorkSafeBC says a tight-fitting mask may not suit every worker or every job. A loose-fitting hood with a fan is one option.
There’s also a new guideline (G8.39) that explains all this in more detail, and WorkSafeBC asks employers to check that their respirator programme, procedures and training still match.
Why it matters outside Canada
None of this is unique to British Columbia. A mask only works if it seals on the face that’s actually wearing it, every time. What BC has done is write it down very clearly, and the list is a good checklist for any company that uses masks, wherever it is.
Sources: WorkSafeBC primer on respirator face seals (PDF, October 2026) · WorkSafeBC announcement, 9 October 2026 · WorkSafeBC Board decision, July 2026
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