Comprehensive Guide to Designated Substance Surveys in Ontario

If you are planning to undertake renovations, demolitions, or alterations in Ontario, Canada, it’s crucial to be aware of the legal requirements related to designated substances. A Designated Substance Survey (DSS) is a fundamental step in ensuring compliance with occupational health and safety regulations.

Understanding Designated Substance Surveys

Designated Substance Surveys are comprehensive assessments that identify and quantify hazardous substances present in a building. These substances, known as designated substances, pose potential health risks to individuals when disturbed or released into the air during construction, renovation, or demolition activities. The surveys ensure safe handling, removal, and disposal of these substances in compliance with applicable laws.

Importance of a Designated Substance Survey

     Occupational Health and Safety Compliance: A DSS is essential for compliance with Ontario’s Occupational Health and Safety Act (OHSA) and it’s designated substances regulations. Complying with these regulations is a legal requirement.

     Protecting Human Health: Identifying and managing designated substances ensures the health and safety of workers, occupants, and anyone in the vicinity during construction, renovation, or demolition.

     Legal Obligations: Property owners and employers are legally obligated to conduct a DSS to protect workers and comply with regulatory standards.

     Project Planning: The survey provides vital information for project planning, including budgeting for abatement or removal of designated substances.

When Should You Conduct a Designated Substance Survey?

A DSS is typically required before any construction, renovation, or demolition activities. It’s important to conduct this survey early in the planning stages to incorporate necessary precautions and costs into your project plans.

Designated Substances in Ontario

The Ontario Regulation 490/09 outlines 11 designated substances. Some common designated substances include asbestos, lead, mercury, and silica. These substances are harmful to human health and must be handled and managed with care during construction, renovation, or demolition.

Steps Involved in a Designated Substance Survey

     Site Assessment: A thorough site assessment is conducted to identify the presence, location, and condition of designated substances.

     Sample Collection and Analysis: Samples are collected from various materials suspected to contain designated substances. These samples are sent to a certified laboratory for analysis.

     Report Generation: A detailed report is prepared based on the findings of the survey. It includes information on the location and quantity of designated substances, as well as recommendations for safe handling and disposal.

Hiring a Qualified Professional

To ensure a comprehensive and accurate designated substance survey, it is advisable to hire a qualified and experienced consulting firm specializing in environmental assessments. They have the necessary expertise and knowledge to conduct a thorough survey and provide actionable recommendations. IES Consulting has performed thousands of Designated Substance Surveys throughout Southern Ontario over the past 25 years.


A Designated Substance Survey is a vital step in ensuring the safety and compliance of construction, renovation, and demolition projects in Ontario. By identifying and managing designated substances properly, you protect the health of individuals and comply with legal obligations. Engage IES Consulting to facilitate a smooth and compliant project. Proudly serving Windsor-Essex, Chatham-Kent, Sarnia-Lambton, London-Middlesex and all surrounding communities.

Designated Substance Survey (DSS)

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Chris Croft Technical Specialist

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