Health and Safety A-Z
Topic: Designated substances
Summary:
Ontario has created specific requirements for work involving any one of eleven hazardous materials known as “designated” substances. Requirements include a written assessment of exposure and a review of that assessment by the Joint Health and Safety Committee. Additional requirements apply to designated substances found in building materials; in most cases a designated substance assessment must be completed and provided to the contractor(s) before a demolition or renovation project can begin.
The 11 designated substances are: Acrylonitrile, arsenic, asbestos, benzene, coke oven emissions, ethylene oxide, isocyanates, lead, mercury, silica, and vinyl chloride.
Review the Procedures for Designated Substance Assessment, Notice, and Control for requirements that apply when one or more designated substances is present in a University workplace or work-related activity. A Designated Substances Assessment Form is required for work with designated substance(s) not related to construction or building materials. Completed forms should be forwarded to healthandsafety@trentu.ca for review.
Designated substance assessments involving building-related projects are normally arranged through the Project Management Office, Facilities Management.
For more information see:
Ministry of Labour, Guide to the Occupational Health and Safety Act, Part IV, Toxic Substances
Ont. Reg. 490/09 – Designated Substances
Additional Resources:
Procedures for Designated Substance Assessment, Notice, and Control
Designated Substances Assessment Form
Last Revised: April 7, 2025