A designated substance survey should be completed when renovation, demolition, or construction work could disturb materials containing asbestos, lead, silica, mercury, or another regulated substance. The resulting designated substance report gives owners, contractors, and workers information about potential hazards before materials are cut, drilled, sanded, removed, or demolished. The project scope matters more than age alone because even a newer property may contain materials that require assessment. You will be able to use your DSS Report to determine if you need more preventative and corrective actions like certified asbestos removal services in Toronto and beyond.
What Ontario Project Owners Need to Know
Section 30 of Ontario's Occupational Health and Safety Act requires a project owner to determine whether designated substances are present and prepare a list before entering a binding contract with a constructor. That information must be provided to prospective constructors as part of the tendering process.
Ontario recognizes 11 designated substances:
- Acrylonitrile
- Arsenic
- Asbestos
- Benzene
- Coke oven emissions
- Ethylene oxide
- Isocyanates
- Lead
- Mercury
- Silica
- Vinyl chloride
Not every substance is likely to be present in every building. The purpose of the assessment is to identify which hazards are relevant to the property and planned work.
Renovations That Commonly Disturb Suspect Materials
Projects that open walls, ceilings, floors, mechanical systems, or exterior assemblies are more likely to require investigation. Examples include:
- Removing drywall, plaster, ceiling tiles, or textured finishes
- Replacing vinyl flooring, ceramic tile, or flooring adhesives
- Cutting concrete, masonry, brick, or stone
- Removing pipe, boiler, or duct insulation
- Altering HVAC, plumbing, or electrical systems
- Replacing windows, roofing materials, siding, or soffits
- Demolishing an addition, garage, or entire building
- Completing a commercial tenant improvement
- Undertaking fire, flood, or structural restoration
Even a relatively small renovation may affect several materials. Installing new lighting, for example, could disturb ceiling finishes, drywall compound, insulation, wiring routes, and concrete.
Why the Survey Must Match the Scope of Work
A survey should examine the areas and materials that the project could disturb. A contractor renovating one washroom may not need the same assessment scope as a team demolishing an entire commercial building.
Plans can also change after construction begins. If workers need to open an area that was not included in the original assessment, the survey may need to be expanded before work continues. This is one reason owners should define the work area clearly and share drawings, specifications, and proposed demolition activities with the consultant.
Our guide to Ontario designated substance survey requirements explains how the assessment fits into project planning and contractor communication.
What the Report Should Tell the Project Team
A designated substance report should document the areas assessed, materials observed or sampled, analytical results, identified substances, and limitations of the survey. It may also provide recommendations for handling, further assessment, or removal before work begins.
The report does not automatically mean every identified material must be removed immediately. The required response depends on its condition, location, regulatory requirements, and whether the proposed work will disturb it.
Complete the Assessment Before Tendering or Demolition
Waiting until demolition begins can expose workers to an unknown material, interrupt the construction schedule, and require emergency testing or containment. Completing the designated substance survey during planning gives the project team time to incorporate appropriate controls, abatement, sequencing, and disposal requirements.
At Inch By Inch Inspections, we use our experience in building construction, operations, and maintenance to prepare objective surveys for renovation, demolition, and construction projects. We help owners define an appropriate scope and provide the documented findings needed before contractors begin disturbing building materials.
