On-Site Magazine

OHS: Whose responsibility is it anyway?

By Adam Freill   

Construction Health & Safety Law

Ontario case creates uncertainty for construction project owners and contractors.

Richard Yehia and Mark Borgo

This past November, the Supreme Court of Canada released its decision in R. v. Greater Sudbury (City), a case about whether the owner of a construction project should be considered an employer under the Occupational Health and Safety Act.

A split decision by the Supreme Court means that a prior decision of the Ontario Court of Appeal, which views the project owner as an employer sharing liability under the OHSA for health and safety on the project, will remain in place.

This has been polarizing across the construction industry in Canada, with many criticizing the decision for being divorced from reality, and others applauding the decision for championing the “belts and braces” approach to workplace safety.



The case stems from the City of Greater Sudbury contracting with Interpaving Limited to act as constructor to repair a watermain. The city also employed inspectors to attend the project site, for quality assurance purposes.

During the project, a pedestrian was tragically struck and killed while crossing an intersection. A Ministry of Labour investigation determined that the project lacked safety measures, such as a fence and signaller, contrary to the OHSA regulations. The ministry charged the city, among others, with breaching its purported obligations as “constructor” and “employer” under the OHSA.

At the lower court levels, the city had successfully argued that it was neither the constructor nor employer. The ministry appealed to the Ontario Court of Appeal, which found the city to be an employer.

The city’s appeal to the Supreme Court arrived at a split decision, resulting in the Court of Appeal decision remaining in place and not providing the clarity project owners were seeking about their health and safety obligations.

The four Supreme Court judges who supported the Court of Appeal decision found that nothing in the OHSA required the ministry to establish that the city had control over the workers or workplace to prove the city breached its OHSA obligations as employer. They found that the city met the definition of employer, having employed quality control inspectors and by hiring Interpaving as constructor.

The other four judges held that it would be absurd to interpret the OHSA in a manner that could arguably obligate every employer at a construction project to ensure compliance with all measures contained in the OHSA regulations.



Notwithstanding the split decision, the majority of the Supreme Court judges noted that the city could avoid conviction if it could show it exercised due diligence under the OHSA, however, the issue of due diligence was not decided by that court, so the case has been sent back to the provincial court for determination.

For now, the viability of the due diligence defence in circumstances where an owner retains a constructor remains uncertain.

Also uncertain is whether the Supreme Court will grant a city motion requestion a re-hearing of the appeal.

In December 2023, Sudbury City Council passed a motion requesting that the province amend the Occupational Health and Safety Act to clarify the definition of employer under the act. It remains to be seen if the Ontario legislature will step in and amend the OHSA to address the potential liability that may arise for project owners as a result of this decision.

For the time being, the practical consequence is that project owners may be found to be an employer under the OHSA by reason of engaging a contractor for a construction project, even though the contractor has the obligations of constructor. This may impose additional risks and create unintended consequences for owners and project developers.

It also raises questions about the scope of owners’ responsibility under the OHSA, the role of the constructor, and the responsibility of contractors.

Owners may want to consider evaluating their current procurement procedures and practices, and include a review of their contractor’s health and safety record, health and safety plan, capacity to ensure compliance with the OHSA, and whether they engage their own health and safety experts to provide reviews and guidance.

It would also be prudent for owners, and contractors taking on projects for owners, to obtain guidance with respect to their own ongoing health and safety obligations and procurement strategies as well.


Richard Yehia, partner, and Mark Borgo, senior associate, are construction lawyers at Borden Ladner Gervais LLP. This article provides an overview and is not intended to be exhaustive of the subject matter contained therein. Although care has been taken to ensure accuracy, this article should not be relied upon as legal advice.  


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