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Designated substances: how changes to regulations will affect you

Feb 18, 2020

Designated substances: how changes to regulations will affect youIf you have designated substances in your workplace, you need to know that Ontario has made changes to O. Reg. 490/09 - Designated Substances, including a new medical surveillance code. These changes took effect January 1, 2020.

A designated substance is a biological, chemical or physical agent or combination considered so hazardous that worker exposure is prohibited, regulated, restricted, limited or controlled. Under O. Reg. 490/09, these 11 chemical agents are prescribed as designated substances:

  • acrylonitrile
  • arsenic
  • asbestos
  • benzene
  • coke oven emissions
  • ethylene oxide
  • isocyanates
  • lead
  • mercury
  • silica
  • vinyl chloride.

Exposure to these substances may cause cancer, strong allergic reactions, liver and lung disorders, and damage to the nervous system. Depending on the substance, symptoms may appear immediately or only over time.

Managing designated substances

The new code sets out medical surveillance requirements for 7 of the 11 designated substances. It replaces nine separate medical surveillance codes with one single consolidated and updated code. Other changes involve how to make airborne measurements and calculate worker exposure.

Understanding the Designated Substances Regulation, including medical surveillance code amendments, is key to protecting workers' health and complying with the requirements, says Jessica Barua, WSPS Occupational Hygienist and Consultant.

"Some workplaces may not understand what the regulation's requirements are, or even that they have a designated substance on site," says Jessica. She suggests starting with these three steps:

  1. Determine if you have designated substances in your workplace by reviewing Safety Data Sheets for all hazardous products in your workplace. Check section 3 for ingredients, and compare the ingredients with Table 1 in the Designated Substances Regulation.
  2. If any of the products contain a designated substance, conduct a walk-through to identify where workers may be exposed. Consider all routes of exposure, including skin absorption and inhalation.
  3. If there is a risk of worker exposure, carry out a detailed designated substance assessment in conjunction with the joint health and safety committee.

To make this task easier, Jessica suggests using a free WSPS tool, Workbook for Designated Substance Assessments, a step-by-step guide that can be used as official documentation demonstrating an assessment has been done. The assessment must be in writing as per the legislation, reviewed by the joint health and safety committee, and available to the committee and the Ministry of Labour, Training and Skills Development.

A designated substance assessment includes:

  • tracking the progress of the designated substance through your facility. "From the time it arrives to the time it leaves, where are the process points and where are the exposures?"
  • conducting exposure assessments. "This is a more technical piece involving air sampling to tell you what the concentrations are in air," explains Jessica. An occupational hygienist or specialist with the knowledge and background to conduct the assessment is required. (See "How we can help.")
  • determining the need for a control program. If the assessment reveals that workers are likely to be exposed to the substance and their health may be affected due to the exposure, a control program is necessary.

A control program includes:

  • establishing controls to mitigate exposures, such as engineering controls, work practices, hygiene practices, procedures for monitoring workplace concentrations, medical examinations as required by the Code of Medical Surveillance, tests, and record keeping. Use personal protective equipment only as a last resort.
  • providing training to supervisors and workers on any designated substances, their health effects, and your control program. This training is in addition to the training workplaces provide under WHMIS 2015.

How we can help

Review the changes O. Reg. 189/19 to O. Reg. 490 and familiarize yourself with the Code for Medical Surveillance for Designated Substances.

Learn more about conducting assessments by attending

WSPS consultants can assist with all aspects of a designated substances assessment, including identifying and quantifying exposure, air sampling, and developing a control program. Call 1-877-494-WSPS (9777).