DSS Report in Windsor: Designated Substances Survey

A DSS report is the written designated substances survey an Ontario project owner needs before construction, renovation or demolition goes to tender: it lists which designated substances are present, where they are and what condition they are in, and it goes to every bidder. Windsor DSS reports start around $1,500. Before a project goes to tender, the owner is required to determine whether designated substances are present and to give that list to every contractor bidding the work. We produce DSS reports for Windsor and Essex County projects: sampled, lab-verified, and formatted so your contractor, and if it comes to it, the Ministry of Labour, gets exactly what the regulation expects.

Call (226) 773-8831 with your project scope, or send the form and we'll quote the survey.

Why the DSS exists, in plain terms

Section 30 of Ontario's Occupational Health and Safety Act puts the duty on the project owner, and it does it in a specific order that is worth knowing because each step has a different person on the hook.

• Subsection 30(1). 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. Note the wording: determine, then list. An assumption is not a determination, and a verbal warning is not a list.
• Subsection 30(2). If any work on the project is tendered, the person issuing the tenders must include a copy of that list as part of the tendering information. Not on request. As part of the package, to everyone bidding.
• Subsection 30(3). The owner must ensure a prospective constructor has received the list before entering into a binding contract with them.
• Subsection 30(4). The constructor then has to ensure every prospective contractor and subcontractor has received the list before each of them signs.

So the list travels down the whole chain, and it has to arrive before the contract is signed, not after the crew is on site. That is the part owners most often get wrong: they commission a survey, the report lands after the tender has already closed, and the sequence the Act actually requires has already been broken.

The full breakdown of that duty, what triggers it, and who carries the cost when the list is missing is set out on asbestos survey before renovation or demolition. General contractors in Windsor increasingly refuse to price a job without one attached to the tender package, because the regulation makes them responsible for passing it down to every subcontractor.

Who is liable when the list is wrong

This is the part of section 30 that almost nothing written for Ontario owners covers, and it is the reason a survey is worth doing properly rather than cheaply. The Act splits liability in two, and the split follows who failed at which step.

Subsection 30(5) puts the owner on the hook for what the survey missed. An owner who fails to comply with section 30 is liable to the constructor and to every contractor and subcontractor who suffers loss or damages as a result of a designated substance later being discovered on the project, where the owner ought reasonably to have known about it but it was not on the list. The test is not whether the owner actually knew. It is what the owner ought reasonably to have known. On a 1950s Windsor building with original pipe insulation and floor tile, "we did not realise" is not a defence anyone would expect to succeed, and a survey that skipped the mechanical room is the kind of gap that reads as unreasonable after the fact.

Subsection 30(6) puts the constructor on the hook for what they failed to pass down. A constructor who fails to comply is liable to every contractor and subcontractor who suffers loss from the discovery of a substance that was on the list. Read those two subsections together and the structure is clear: the owner owns the completeness of the list, the constructor owns its distribution. A thorough survey that sits in a project manager's inbox and never reaches the drywall sub protects nobody.

What "loss or damages" means in practice is the project stopping. Crews stand down, the abatement gets priced under emergency conditions rather than competitively at tender, and the schedule absorbs the delay. That exposure is what the survey is bought to remove, and it is why the cheapest possible survey is usually a false economy: the liability under 30(5) attaches to what a reasonable survey would have found, not to what your survey happened to look at.

The eleven designated substances

Ontario designates eleven substances under O. Reg. 490/09. The full list is acrylonitrile, arsenic, asbestos, benzene, coke oven emissions, ethylene oxide, isocyanates, lead, mercury, silica, and vinyl chloride. In ordinary buildings the ones that actually show up are:

• Asbestos. The big one, in pipe insulation, fireproofing, floor tiles, joint compound, plaster, and transite. In Windsor's pre-1990 stock it should be assumed until sampled.
• Lead. Paint in pre-1980 buildings, solder, some flashings and pipes.
• Silica. Concrete, brick, and masonry, relevant the moment anyone cuts or grinds it.
• Mercury. Thermostats, switches, fluorescent lamps.
• PCBs live in old light ballasts and transformers (technically handled under separate rules, but flagged in a good survey).

The remaining substances (acrylonitrile, arsenic, benzene, coke oven emissions, ethylene oxide, isocyanates, vinyl chloride) are industrial-process chemicals: rare in ordinary buildings but relevant for some of Windsor's plants, and a proper DSS addresses them rather than ignoring them.

Why quoting O. Reg. 490/09 at a contractor does not do what people think

Owners and consultants often cite O. Reg. 490/09 as the rule that forces a survey on a construction project. It is the regulation that names the eleven substances, so it matters, but it is not the source of the duty on a project, and section 14 of that regulation is explicit about it: despite sections 3 to 13, the regulation does not apply, at a project, to an employer who engages in construction.

That exception is there because construction work is governed by its own regime rather than by the assessment and control-program machinery 490/09 sets up for fixed industrial workplaces. On a construction project the obligations come from OHSA section 30 for the survey and the list, and from O. Reg. 278/05 for how asbestos work is classified and carried out once something is found.

The practical consequence is worth being precise about. If a contractor tells you 490/09 does not apply to their project, they may well be right about that regulation and still entirely wrong about the outcome, because the section 30 duty is unaffected by it and sits on the owner regardless. Arguing the wrong regulation is how these conversations stall. Section 30 is the one that settles it.

What we deliver

1. Site inspection. We walk the project area, identify suspect materials, and document locations and conditions with photos.
2. Sampling and lab analysis. Bulk samples of suspect asbestos materials and paint samples for lead go to a CALA-accredited laboratory under chain of custody.
3. The DSS report. Substance-by-substance findings mapped to the building, lab certificates attached, and clear statements of what's present, where, and in what condition. Written to be handed directly to bidders.
4. Work classification guidance. For asbestos findings, the report identifies what Ontario's O. Reg. 278/05 would classify the planned disturbance as (Type 1, 2, or 3), so contractors can price abatement properly instead of padding for the unknown.

We test, sample, and report. We do not perform removal or abatement, which means the survey has no commercial interest in finding more material than is actually there. When a report says a material is present and in good condition, nothing downstream of us is priced off that answer.

What the DSS report itself contains

A DSS report is not a one-line pass or fail. Contractors and the Ministry of Labour expect it structured so anyone bidding the job can act on it without calling us first:

• A substance-by-substance summary, listing each of the eleven designated substances and whether it was found, not found, or assumed positive because it could not be safely sampled.
• A location map or floor-by-floor breakdown, tying each finding to where it actually is in the building, not just "asbestos present somewhere."
• Material condition notes, since a positive material in good condition is priced differently than one that is already damaged or friable.
• The lab certificates, attached as backup for every sample referenced in the summary.
• A work classification note for asbestos findings, mapping the planned disturbance to O. Reg. 278/05 Type 1, 2, or 3, so bidders price the actual category instead of the worst case.

That structure is what turns the report into something a general contractor can hand straight to subtrades, rather than a document someone has to interpret.

How to read a DSS report you have been handed

Plenty of people arrive at this page holding a report somebody else commissioned, trying to work out what it obliges them to do. Read it in this order.

Start with the assumed-positive entries, not the positives. A competent survey marks some materials assumed positive because they could not be sampled safely or could not be reached without destructive access above an occupied space. Those entries behave exactly like positives for pricing and precautions until someone samples them. They are also the entries most likely to be quietly dropped when a bidder builds their number, and the most common source of a mid-project surprise on a report that technically said everything it should have.

Check that every finding has a location, not just a material. "Asbestos present in floor tile" is not actionable. "Nine-inch floor tile and black mastic, second floor east corridor, good condition" is. If the report names materials without tying them to places, subtrades cannot price the work and the report has not done its job.

Check the condition notes against the scope of your work. Material in good condition that nobody is going to touch is usually managed in place rather than removed. The same material in the middle of a demolition footprint is a different job at a different price. The report describes the building; the scope decides what that means.

Check the survey date and what it covered. A survey describes a building as it was on inspection day, and it covers the areas the surveyor was given access to. If the report has an access-limitations section, that section is telling you where the unknowns are.

Then look at the Type classification for any asbestos finding. Type 1, 2, and 3 under O. Reg. 278/05 carry materially different procedures and costs. A bid that does not distinguish them is a bid built on an average, which means it is wrong in one direction or the other.

If a report you have been handed is thin on any of the above, that is worth resolving before the tender closes rather than after. We are happy to look at an existing report and say plainly what is missing, whether or not the follow-up work comes to us.

DSS versus air quality testing

These get confused because both involve sampling. A DSS is a pre-project survey of building materials, done before anything is disturbed, to identify what is present. Air quality or clearance testing is different: it samples the air itself, usually after abatement work or when something has already been disturbed, to confirm the space is safe to reoccupy. A project can need both, in sequence: the DSS identifies what is present before work starts, and air testing confirms the air is clear once the identified material has been removed. See our asbestos air testing page for that second step.

Windsor projects that need this

• Demolition of any pre-1990 structure, houses included
• Commercial unit fit-outs and renovations where walls, ceilings, or floors get opened
• Municipal, school board, and institutional work (their tender templates require the DSS)
• Plant maintenance shutdowns where insulation and coatings get disturbed
• Fire and flood restoration work on older buildings, where the reno starts whether anyone planned it or not

Windsor's building stock makes this routine: most structures in the core neighbourhoods and the industrial corridors predate the asbestos phase-out. Owners who build the DSS into the project schedule from day one never think about it again. Owners who discover the requirement from their GC's lawyer lose weeks.

For a smaller residential project where asbestos is the only realistic concern, a full DSS is often more than the job needs. Residential asbestos testing covers that case, and commercial asbestos testing covers the middle ground where the building is commercial but the scope is narrow.

Common questions

Call (226) 773-8831 with your project address and scope, or send the form. Quotes are quick.