Understanding Welding Fume Exposure in Ontario Workplaces
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Welding fume exposure has gained a lot of international attention over the last decade.
The International Agency for Research on Cancer (IARC) classifies welding fume as a Confirmed Human Carcinogen – a rating the agency uses for agents that carry the strongest evidence of causing cancer in humans. Welding fumes contain hazardous metals and gases that affect the lungs, nervous system, and even the brain.
In this article, we’ll break down the health risks, legal responsibilities under Ontario’s health and safety laws, and what employers can do to reduce risk and protect workers.
Welding fume exposure has gained a lot of international attention over the last decade.
The International Agency for Research on Cancer (IARC) classifies welding fume as a Confirmed Human Carcinogen – a rating the agency uses for agents that carry the strongest evidence of causing cancer in humans. Welding fumes contain hazardous metals and gases that affect the lungs, nervous system, and even the brain.
In this article, we’ll break down the health risks, legal responsibilities under Ontario’s health and safety laws, and what employers can do to reduce risk and protect workers.
Schedule an occupational hygiene consultation.
Why Welding Fume Exposure Is a Health Concern
When metal is heated to the temperatures often used in welding (often thousands of degrees celsius), metal melts and some of it vapourizes. Shortly after this rises up into the air, the vapour cools and changes into a very fine particle called a fume. Fumes enter the deepest parts of the lung causing potential harm.
Welding fumes contain a mixture of metals and other substances – manganese, nickel, chromium, cadmium, iron and other metals, plus other gases and vapours. Each of these components are harmful in their own way.
Schedule a free 30-minute consultation with a Registered Occupational Hygienist.
Ontario Regulations on Welding Fume Exposure
Workplaces in Ontario where welding is performed should refer to Ontario Regulation 833, employers must ensure hazardous substance exposure in the air, like welding fume components, do not exceed established limits. Employers also have duties under the Occupational Health and Safety Act to take every reasonable precaution to protect workers.
If your workplace performs welding, you may need to conduct air monitoring if inspectors from the Ministry of Labour, Immigration, Training and Skills Development visit your workplace. This can also help determine the best type of ventilation system needed or to determine if it is being used properly or functioning correctly.
How to Assess Welding Fume Hazards
Understanding if your workplace may have a problem with welding fume exposure, it’s good to start by collecting information about the following:
- The type of welding being performed (e.g., MIG, TIG, Stick), how much
- The base metal and filler materials used
- Existing controls (ventilation, fume extractors, respiratory protection)
- Work environment (confined spaces, general air flow).
Hiring an occupational hygienist to perform a welding fume assessment and air monitoring is the most effective way to determine if you’re at risk of non-compliance and if workers are at risk of harm.
WorkBright helped our health and safety team with an occupational hygiene assessment. Mike communicated effectively and prepared our team for the day for the day. His findings were thorough and clear to understand which gave us and our employees confidence. We truly value his expertise.
Questions about welding fumes in your workplace?
Hierarchy of Controls for Welding Fumes
The best approach to managing welding fume exposure follows the hierarchy of controls:
Elimination / Substitution
Physically remove or replace the hazard where possible.
- If feasible, eliminate welding entirely by using bolting, riveting, or adhesives to join metals, or other non-welding methods.
- Substitute the welding process with a lower-fume welding processes like TIG, or switch to automated welding and enclose the process.
- Substitute standard filler metals with low-manganese filler metals to reduce manganese emissions.
Engineering Controls
- Install Local Exhaust Ventilation (LEV) or welding ventilation system. These systems capture fume and remove it from the welder’s breathing zone, dramatically reducing welding fume exposure.
- For portable welding, a portable fume extractor can protect workers.
Administrative Controls
- Implement training on safe welding practices such as proper torch positioning, arc stability, and optimizing weld settings to minimize fume.
- Rotate staff and reduce duration of exposure.
- Use signage and barriers to keep unauthorized bystanders away.
Personal Protective Equipment (PPE)
- Respirators equipped with appropriate filters should be used (i.e. P100 particulate filters). Ensure each worker’s respirator fits properly and is the correct type. PPE should be used in conjunction with other controls and is usually the least effective method to protect workers.
Protecting Workers from Welding Fume Exposure
Welding is an important function. It can be performed safely and in a way that reduces welding fume exposure. This keeps workers healthy, productive and happy, while ensure your workplace is in compliance with health and safety laws.
Need Help with Welding Fume Exposure?
At WorkBright, we support employers and workplaces with comprehensive occupational hygiene, including assessments for welding fume exposure, air monitoring, and respirator fit testing services. We’ll help you meet your obligations under Regulation 833 and protect your team in the process.
Book a consultation today and make sure your workplace is as safe as it is productive.
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