Health and Safety ReportVolume 24, Issue 07

As changes to climate leads to more extreme weather events, smoky skies and hazy horizons are becoming a more familiar sight across Canada. Wildland fires, dust storms, pollen and human activity all contribute to poor outdoor air quality. For employers, this is a growing workplace health and safety concern. 

Employers are required to take every reasonable precaution to protect workers from workplace hazards, including hazards in the air. When air quality drops, the health effects on workers can range from mild irritation to serious, depending on who is exposed and how. 

Who is most at risk 

All workers can experience symptoms during a poor air quality event, including eye irritation, extra mucus in the nose or throat, coughing, or trouble breathing. Physical exertion tends to make breathing difficulties worse, so anyone working hard outdoors is more likely to feel effects. 

Some groups do face a greater risk. Older workers, pregnant workers, and anyone with existing health conditions such as cancer, diabetes, allergies, or heart and lung disease may experience stronger or more frequent symptoms. Implementing air quality precautions can benefit everyone, as some workers may not know they have a condition that poor air quality could aggravate. 

Making sense of the numbers 

Most of Canada uses the Air Quality Health Index, or AQHI, to help people understand the daily health risks from air pollution. (Québec uses the Info-Smog program). The AQHI scale runs from 1 to 10+, with 1 representing safe conditions and anything above 10 signaling a very high-risk event. Most weather apps and networks report the AQHI alongside the regular forecast, making it an easy tool to check before any outdoor work begins. 

As the index climbs, the advice becomes more cautious. At low risk, usual outdoor activities are fine. At moderate risk (4-6 on the AQHI scale, people who notice symptoms like coughing or throat irritation should speak to their manager or supervisor about reducing strenuous outdoor work). At high risk (7-10 on the AQHI scale), employers should reduce or reschedule strenuous outdoor activity, taking extra precautions for workers who are older or otherwise more vulnerable. At very high risk, strenuous outdoor work should be avoided altogether. Severe air quality alerts, usually shared through local weather networks, are a signal that conditions have reached a hazardous level. These alerts are colour-coded, based on possible risks.  

What employers can do 

Start by building poor air quality events into your workplace's emergency preparedness plan, and train workers on what your plan involves. Because the right response depends on both the severity of the air quality and the type of work being done, it helps to think about outdoor and indoor workers separately. 

For workers outdoors, protective measures might include limit the time spent outside, shifting outdoor tasks to times when air quality improves, or, in severe conditions, cancelling outdoor work entirely. If work must be done, provide appropriate personal protective equipment based on a proper risk assessment, 

For indoor workers, the goal is to keep outside air from getting in. This can mean adjusting the HVAC system to recirculate indoor air rather than draw in outside air, keeping windows closed, running an air purifier, and making sure any air filters in use have the right rating and are replaced on schedule. 

Poor air quality is no longer a rare occurrence, so treating it as a standard part of workplace safety planning, rather than an occasional inconvenience, means employers and workers can always be ready. Checking the AQHI regularly, knowing which workers have indicated they may be more vulnerable, and having a clear plan before smoke or dust rolls in can make the difference between a manageable day and a genuinely hazardous one. 

Resources 

• Outdoor Air Quality, CCOHS 
• Extreme Weather, Preparing for Climate-Related Emergencies, CCOHS 
• About the Air Quality Health Index, Government of Canada 

Health Canada and waste management groups are noticing a rise in nitrous oxide cylinders being thrown away in municipal garbage bins. This poses serious risks to workers, the public, and waste-processing equipment. 

When these gas cylinders are thrown away incorrectly, they can explode or rupture if crushed, compacted, or heated during waste collection and processing. Nitrous oxide fuels existing fires, so any explosion in a waste facility is an immediate fire hazard. 

Do not place compressed gas cylinders in the garbage or recycling. Check your local hazardous waste guidance on where to safely dispose of these cylinders, and make sure the canisters are completely empty before disposal. Commercial size cylinders should be returned to the manufacturer.  

If you’ve noticed similar issues with discarded nitrous oxide cylinders in your area or have information about safety measures in place, report it to Health Canada at toxicovigilance@hc-sc.gc.ca. 

For more information: https://cwma.ca/waste-stream-watch-nitrous-oxide-containers/ 

Featured podcast: What Occupational Health and Safety Could Look Like in 2040 

Dr. Arif Jetha recently led a research study that scanned nearly 400 signals of change to map out where occupational health and safety is headed. He explains why leaders need to balance today's challenges with tomorrow's, and what employers, policymakers and workers can do to stay ahead. 

Listen to the podcast now. 

Encore podcast: Top Picks for Travel Tips 

Despite the season or destination, safety should always be a critical part of your travel plans. From planning and preparation all the way to hotel precautions and communication procedures, we’ll review timely and relevant tips for a safe and healthy trip.  

Listen to the podcast now. 

See the complete list of podcast topics or, better yet, subscribe to the series on YouTube, iTunes or Spotify and don't miss a single episode. 

Featuring a new look and improved user experience, our enviroOSH Legislation Service keeps you up to date on health, safety, and environmental legislation across Canada. As a subscriber you will enjoy:

• Powerful search functionality so you can quickly determine your health and safety responsibilities under the law.
• Greater compliance support with immediate access to up-to-date legislation, regulations, and guidelines that matter to your workplace.
• Regular updates and reports on legislative changes, as well as access to CSA, CGSB, and WorkSafeBC standards.

Learn more about how the enviroOSH Legislation Service can help you meet your health and safety requirements.

We’re still accepting applications for the $3,000 Chad Bradley Scholarship, but time is running out – the deadline to apply is August 31, 2026. 

The scholarship is open to women enrolled in a post-secondary occupational health and safety program at a Canadian college or university. 

Learn more about the scholarship, essay criteria, and how to apply: www.ccohs.ca/scholarships/cbradley/.  

If you’re thinking about attending CCOHS Forum on October 28-29 in St. John’s, Newfoundland and Labrador, here are five reasons to join us. 

1. Intimate and interactive: Our intimate event size and single-session stream combined with networking opportunities let you dive deeper into topics while connecting with like-minded peers.  
2. Fresh content: Learn about the health and safety issues every workplace needs to prepare for, from emerging technologies to the evolution of psychological health and safety. 
3. Solutions-focused: Learn from our diverse speaker lineup, showcase of innovations, and networking and interactive events to gain insights on health and safety, plus practical solutions and tools you can bring back to your workplace. 
4. Incredible value: Your registration includes all speaker sessions, networking events, showcase of innovations, refreshments and lunches. 
5. Balanced perspectives: Get perspectives from labour, government, and employer groups. 

For more information, including our speaker lineup and topics so far, visit: www.ccohs.ca/forum.