Smoke & Air Quality

Protecting your health from wildfire smoke, from the AQHI scale to N95 respirators, HEPA cleaners, and who is most at risk.

AQHI runs 1 to 10+ — the higher the number, the higher the risk

Wildfire smoke can push the AQHI past 10+ — the off-the-scale band where everyone is told to reduce outdoor activity, not just sensitive groups.

Fine particles (PM2.5) are the main health risk from smoke

There is no safe level of PM2.5 exposure — Health Canada attributes up to 2,500 deaths a year nationally to long-term wildfire-smoke particle exposure.

N95 respirators help; cloth and surgical masks do not

Cloth, surgical and bandana-style masks do nothing for wildfire smoke — only a well-fitted NIOSH-certified N95 or equivalent meaningfully filters PM2.5.

A portable HEPA cleaner is the best indoor smoke defence

A portable HEPA cleaner sized to the room is the single most effective household defence against wildfire smoke — central HVAC alone usually is not enough.

Designate one cleaner-air room and seal it during smoke events

A single bedroom with the door closed and a HEPA cleaner running becomes far cleaner than the rest of the house — that is the cleaner-air-space strategy in one sentence.

Children, seniors and people with heart or lung conditions are most at risk

Children breathe more times per minute relative to body size than adults — so for a given concentration of smoke, they take in more PM2.5 per kilogram of body weight.

Heavy, prolonged smoke is a reason to leave the area

Multi-day AQHI 10+ in a home that cannot be kept reasonably clean is a medical reason to leave town — for vulnerable people, geography is the most effective filter.

Pets feel smoke too — keep cats and brachycephalic dogs indoors

Cats groom smoke residue out of their fur and ingest it — which is why the BC SPCA tells guardians to keep cats indoors during air-quality advisories, not just dogs.

Skip outdoor exercise when AQHI is high

Vigorous outdoor exercise during heavy smoke can pull PM2.5 deep into the lungs at five-to-ten times the resting rate — which is why Health Canada says to reschedule, not push through.

Outdoor workers need real respirators and clean-air breaks

Outdoor smoke exposure on the job is a regulated workplace hazard in BC, Alberta and much of the US — employers can be required to provide respirators and clean-air breaks when air quality is poor.

Know the symptoms of smoke exposure and when to seek care

Using your asthma reliever inhaler more often than usual during a smoke event is a sign to call a doctor — not a sign to keep pushing through.

Wildfire smoke can travel thousands of kilometres on the wind

Northern BC wildfire smoke regularly turns the sky orange in Toronto and New York — plumes can travel thousands of kilometres before settling to ground level.

These articles are the same wildfire safety library that lives inside our free app. Browse every category in the safety library, or open the live map to see current fires and alerts across Western Canada and 18 western US states.