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Are your workers exposed to dangerous designated substances? Here’s how to find out.

A new employer recently told WSPS’ Kelly Fernandes a surprising story. He had worked around the country for 20 years using the same chemical, but no one had told him it was a designated substance or how to protect himself. When he started his business, he still didn’t know, until his workplace received a visit from the Ministry of Labour, Immigration, Training and Skills Development (MLITSD).

Designated substances are chemicals that pose such severe health risks – cancer, liver and lung disorders, damage to the nervous system, and more – that they have their own regulation under the Occupational Health and Safety Act (OHSA): O. Reg. 490/09, requiring employers who use designated substances to take certain actions to reduce workers’ risk of exposure. Hazardous chemicals are also the focus for upcoming MLITSD inspections from July 2, 2024 to March 31, 2025.

But there is a gap in awareness of the regulation, says Kelly, a Specialized Consultant at WSPS and Certified Industrial Hygienist. “Some employers don’t know they are using designated substances and/or what their legal requirements are for controlling worker exposures.” So, workers may be exposed without the employer knowing it and are not being adequately protected.

In 2023, there were 19,261 occupational illness claims in Ontario, notes Kelly. “That is really high.” To help bring that number down, employers need to know whether designated substances are being used in the workplace, and if they are, what they are required to do under O. Reg. 490/09.  Kelly provides answers below.

A designated substances Q&A: Your questions answered

  1. What chemicals are considered designated substances? There are 11 designated substances in Ontario, says Kelly — acrylonitrile, arsenic, asbestos, benzene, coke oven emissions, ethylene oxide, isocyanates, lead, mercury, silica and vinyl chloride.  

  2. How do I know if the products I use contain designated substances? “Some industries are known to have products that contain designated substances,” says Kelly. For example, crystallized silica is found in stone or granite countertops, and isocyanates are a common ingredient in paints. “If you work in either of these industries, the regulation likely applies to your workplace.”

    Employers can compare the chemical agent name or Chemical Abstracts Service (CAS) number of the products they use with those of the designated substances listed in Table 1 in O. Reg. 490/09. “Make sure you have up-to-date Safety Data Sheets for all the products in your workplace,” says Kelly.

  3. I’ve discovered that the products in my workplace contain designated substance(s). What am I required to do now? Employers are required to carry out an assessment (and record it in writing) to determine the likelihood of worker exposure, and the need for a control program.

    The assessment tracks the progress of the designated substance through your facility,” says Kelly, “from the time it arrives to the time it leaves to see where exposure may occur.” The assessment can be carried out by someone knowledgeable about health and safety best practices or the processes in your facility, in conjunction with your joint health and safety committee (JHSC).

  4. My workplace has fewer than 20 employees, so we don’t have a joint health and safety committee. What should I do? “Workplaces that use designated substances, and where O. Reg. 490/09 applies, are required under the OHSA to have a joint health and safety committee in place, regardless of the number of employees,” says Kelly.

  5. Are there resources available to help me with the assessment? “Definitely,” says Kelly. “Ontario’s health and safety system, which includes the MLITSD and health and safety associations – like WSPS – are here to help employers understand the law and set up programs that keep workers safe and protect employers from fines and other liabilities.” In addition, WSPS has a free download that can help an employer conduct a designated substances assessment in-house.   

  6. The assessment has determined that my workers are exposed to a designated substance. What happens next? Employers are required to put into effect a designated substances control program. “Employers must explore effective control options listed in the hierarchy of controls, including elimination, substitution, engineering controls, hygiene facilities, hygiene practices, and specific work procedures.

    “Personal protective equipment may also be required even after controls are in place to protect your workers” notes Kelly. The MLITSD states: “use of PPE is considered the last line of defense in controlling exposure and should only be relied on if neither substitution nor engineering controls are reasonable, practical, or effective.”

  7. What else does the control program require?

  • Air sampling must be carried out to determine the airborne concentrations of the substance and the direct exposure to workers. Air sampling must be carried out by an occupational hygienist or specialist.

  • Training must be provided to supervisors and workers on the health effects of the designated substances and the key requirements in the control program. For information on the health effects of each of these substances, see the NIOSH Pocket Guide to Chemical Hazards.

  • Ongoing medical surveillance for certain designated substances must be carried out. “These are specific medical examinations or protocols depending on the designated substances to which the worker is exposed,” notes Kelly.

How WSPS can help

WSPS occupational hygiene consultants can help you carry out your assessment, conduct air sampling, develop a control program, and provide training to workers. Contact a consultant today.




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The information in this article is accurate as of its publication date.