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Carbon monoxide: 5 ways you and your JHSC can protect everyone against this deadly hazard

Air Intakes

"Protecting ourselves from carbon monoxide exposure requires year-round vigilance, but especially now," says WSPS occupational hygienist Ilma Bhunnoo. "In the summer, fresh air from open doors and windows can supplement our ventilation systems. But now that we all keep those door and windows closed against the cold, carbon monoxide from a variety of sources may build up to dangerous levels."

Bhunnoo offers five suggestions to help your joint health and safety committee identify hazards and make recommendations. But first, a few insights on exposure sources.

"Any combustion process can produce carbon monoxide," she notes. "This includes propane powered lift trucks, gas heaters, blast furnaces, and welding and torching if it's using a carbon gas mixture." Other contributors include aging or faulty equipment and ventilation systems, and workplace changes, such as new processes, new enclosures that reduce air circulation and ventilation, and higher rates of production, which often mean more lift trucks moving goods.

"In several ways, JHSCs and health and safety representatives are in a unique position to collect information and make recommendations," says Bhunnoo. For example, they already

  • inspect the workplace monthly. "This makes them ideal partners for conducting initial hazard recognition. When it comes to testing, you can be easily trained to take preliminary samples with Draeger or colorimetric tubes."
  • have an insider's knowledge of the workplace. "Worker members in particular may hear, see or smell things on the floor that others may miss, such as more particulates or fumes in the air, a malfunctioning motor or wall fan, vehicle exhaust, or more off-gassing from an oven."
  • know their co-workers. JHSC members and health and safety representatives may have a better eye for workers displaying symptoms of exposure (e.g., unusual drowsiness), or know of workers whose health conditions may put them at greater risk. Co-workers may also feel more comfortable sharing concerns.

How to support your JHSC/health and safety representative

Ensure your JHSC or health and safety representative

  1. is aware of carbon monoxide hazards, knows how to use basic assessment tools, and understands control options. "It's no different from the way you would approach any other hazards: recognize, assess, control and evaluate," says Bhunnoo.
  2. compiles and prioritizes a list of common sources and locations to check during their monthly inspections, including outside sources. Is anything interfering with air intake vents? Do vehicles park near air intakes?
  3. measures for time-weighted average exposures (25 parts per million) as well as excursion limits, which should not exceed three times the time-weighted average for any period of 30 minutes.  And in addition, the excursion limit should not exceed five times the time-weighted average at any point. "The highest CO levels may occur in the vicinity of a propane powered lift truck that is repeatedly backing up and releasing exhaust particulates and gases while loading and unloading trailers during shipping and receiving. This is why it's critical that workplaces with propane-powered lift trucks follow the manufacturer's preventive maintenance schedule. Watch for pockets of space where air circulates less frequently and carbon monoxide could accumulate, such as corners."

Provide additional support with these two opportunities:

  1. ensure all workers are up to date on WHMIS training, and understand their duties under the Occupational Health and Safety Act*
  2. conduct a carbon monoxide awareness campaign aimed at everyone in the workplace.

How WSPS can help

  • If carbon monoxide testing results suggest workers may be exposed to excessive levels, talk to one of our occupational hygienists. They can conduct a thorough workplace assessment, and work with you on cost-effective solutions.
  • Ensure your JHSC or health and safety representative has the knowledge and skills to fulfil their responsibilities.** Check out related resources, where you'll find
    • a summary of what the law says
    • online and classroom courses
    • free downloads, including FAQs and forms


* Duties include working in compliance with the act and regulations, using any equipment, protective devices or clothing required by the employer, telling the employer or supervisor about any known missing or defective equipment or protective device that may be dangerous, and reporting any known workplace hazard or violation of the Act to the employer or supervisor.