Indoor Air Quality Awareness

Yes. Every Canadian province and territory, plus the federal Canada Labour Code Part II (Section 124), imposes a general duty on employers to maintain a safe and healthy workplace - and air quality is part of that obligation. British Columbia goes further with OHS Regulation Section 4.70, which sets specific indoor air quality requirements covering ventilation, temperature, and contaminant controls. An IAQ complaint from a worker is a reportable concern under OHS legislation in most jurisdictions, and employers are required to investigate and document their response - not simply tell the worker to open a window.

The most common early symptoms are headaches, fatigue, difficulty concentrating, and irritation of the eyes, nose, or throat - symptoms that typically appear during the workday and improve after leaving the building. When multiple workers in the same area develop similar symptoms at the same time, this pattern strongly suggests an IAQ problem rather than individual illness. Visible mould, musty odours, stained ceiling tiles, or a noticeable chemical smell after renovations are building-level warning signs that a walk-through assessment is needed.

Carbon monoxide is colourless, odourless, and tasteless - workers cannot detect it without monitoring equipment. A propane forklift operating in a closed 10,000-square-foot warehouse with inadequate make-up air can raise CO concentrations above the Canadian 25 ppm action level (the TLV-TWA adopted by most provinces) within 20 minutes of start-up. CO alarms must be installed in any enclosed area where internal combustion or combustion heating equipment operates, and dosimeter badges alone are not sufficient because they cannot respond fast enough to a rapidly rising concentration to protect a worker before dangerous levels are reached.

Health Canada's radon action level is 200 Bq/m³ - workplaces where testing exceeds this threshold should be remediated. Radon is the number one cause of lung cancer among non-smokers in Canada, responsible for approximately 3,200 lung cancer deaths per year. Testing is recommended in all Canadian workplaces located on or below ground level, including offices, warehouses, and retail spaces. Sub-slab depressurization - a pipe and fan system that vents radon before it enters the building - is over 99% effective at eliminating radon entry once a problem is confirmed.

Start with a walk-through assessment: check that supply and return air registers are unobstructed, look for visible moisture stains or mould on ceiling tiles and walls, confirm HVAC filter replacements are current, and identify any chemical storage or recent renovation activity in the affected area. A CO₂ meter is an inexpensive, practical first tool - a reading above 1,000 ppm during normal occupancy indicates inadequate ventilation. The Joint Health and Safety Committee (required in most Canadian jurisdictions for workplaces with 20 or more workers) must be involved in IAQ investigations, and the employer is obligated under OHS legislation across all jurisdictions to apply the hierarchy of controls - source control and engineering controls first, not just PPE as a permanent fix.