What does the law say?
Section 30: Before beginning a project, the owner shall determine whether any designated substances are present at the project site and shall prepare a list of all designated substances that are present at the site.
(Occupational Health and Safety Act, s. 30 (1), read November 5, 2026)
| Who | Must |
|---|---|
| The owner | Determine whether designated substances are present and list them before the project begins (s. 30 (1)) |
| Whoever issues tenders | Include the list in the tendering information (s. 30 (2)) |
| The owner | Make sure a prospective constructor has the list before a binding contract (s. 30 (3)) |
| The constructor | Make sure each prospective contractor and subcontractor has it before their contracts (s. 30 (4)) |
| An owner who does not comply | Is liable for losses from a substance later found that the owner ought reasonably to have known of (s. 30 (5)) |
Which substances are designated?
Eleven, named in Ontario Regulation 490/09: acrylonitrile, arsenic, asbestos, benzene, coke oven emissions, ethylene oxide, isocyanates, lead, mercury, silica and vinyl chloride (O. Reg. 490/09, read November 5, 2026). In an older commercial building the usual ones are asbestos in tiles, plaster, insulation or drywall compound, lead in paint, mercury in lamps and switches, and silica in concrete and masonry.
How is the list made?
Usually by a designated substances survey: a consultant inspects and samples the areas the work will touch and writes a report. That report becomes the list the Act requires. Asbestos removal itself has its own notices before work (Notice of Project and the constructor).
Does this apply to a house?
This page is about commercial and other workplace projects, where the duty is plain. Whether and how it applies to a private home is a question for the Ministry of Labour or a lawyer, so this page does not answer it. A house built before the 1990s can still contain asbestos, and tearing one down has its own rules (tearing down a house to rebuild).
How does JDT handle it?
On a commercial job JDT Construction Inc. asks for the owner's list before the proposal is signed, and the work is planned around it. The other approvals for a commercial build are on the commercial page.