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Owners, Employers, and OHSA Liability: Lessons for Ontario Employers from R. v. Greater Sudbury (City)
For Ontario employers in construction and other high-risk industries, R. v. Greater Sudbury (City) (2023 SCC 28) is one of the most important occupational health and safety decisions in years. The Supreme Court of Canada confirmed that an owner who hires a contractor to run a project can still be an "employer" under Ontario's Occupational Health and Safety Act, carrying the full set of employer safety duties, and that the owner's degree of control over the work has nothing to do with whether those duties apply. The decision sounds alarming for owners, but the rest of the story is reassuring: control is the heart of the due diligence defence, and when the case returned to the lower courts, the City used that defence to win an acquittal.
The practical takeaway is not that owners are automatically liable for every contractor's misstep. It is that owners are within the reach of OHSA employer duties and need a real, documented due diligence program to defend themselves. That defence is not theoretical. When this case went back to the lower courts on the due diligence question, the City of Greater Sudbury established that it had taken reasonable steps in the circumstances and was acquitted, a result the Crown was later refused leave to appeal.
Do you own or manage projects where contractors do the hands-on work?
After Greater Sudbury, contracting the work out does not put you outside the OHSA's employer duties. What protects you is a documented due diligence program you can put in front of a court. Get your safety oversight and records reviewed before an incident tests them.
Call: 1-800-771-7882 Review My Safety ComplianceBackground: a fatality on a contracted-out project
The City of Greater Sudbury hired a general contractor, Interpaving, to carry out a downtown road repair project and engaged it as the constructor. During the work, a member of the public was struck and killed by a road grader operated by one of the contractor's workers. The City was charged under the OHSA both as a constructor and as an employer, even though it did not employ the grader operator and was not running the day-to-day work.
The Ontario Court of Justice acquitted the City, finding that the contractor, not the City, had direct control over the workers and the intersection, so the City was not an "employer," and that in any event the City had acted with due diligence. The provincial offences appeal court upheld the acquittal but did not deal with the due diligence finding. The Court of Appeal for Ontario reversed, holding that the City was an "employer" that had breached its duty under section 25(1)(c), and sent the due diligence question back to be decided. The City appealed to the Supreme Court of Canada.
What the Supreme Court decided
An owner can be an "employer" under the OHSA
The Court confirmed that an owner who contracts with another party to act as constructor still retains employer duties to protect worker health and safety on the project. The OHSA imposes broad, overlapping, and non-delegable duties on multiple participants at a worksite, so contracting out the work does not contract out the duty.
Control is irrelevant to "employer" status
All eight judges agreed that the degree of control an owner has over the work is not a factor in deciding whether it is an "employer." If you employ workers on the project or have an employment relationship engaged by the statute, the employer duties attach regardless of how much of the work you actually direct.
Control belongs in the due diligence analysis
Control is not gone from the picture, it simply moves to where it belongs. An owner's lack of control over the work can support a due diligence defence by showing it took all reasonable steps in the circumstances. The less practical control you had, the more that can help establish due diligence.
An equal split left the Court of Appeal intact
The Court divided four to four. Because there was no majority, the appeal was dismissed and the Court of Appeal's ruling stood: the City was an employer in breach of the Act, and the due diligence defence was remitted to be decided.
"The Greater Sudbury ruling shows that liability under Ontario's OHSA can apply broadly. Employers can't afford to rely solely on direct responsibility when assessing legal risk, control over the worksite is a key factor. This makes it even more important for employers to take a top-down approach to safety and compliance. Everyone on site, whether an employee or contractor, must be treated as a potential liability point."
Christopher Achkar, employment lawyer and founder of Achkar Law
Key lessons for Ontario employers
Assume employer duties apply, even on contracted-out work
If you own or run a project where a contractor does the hands-on work, do not assume the contract shifts all OHSA responsibility away from you. After Greater Sudbury, the safer planning assumption is that employer duties reach you, and your protection is the steps you take and document, not the wording of the contract.
Build the due diligence defence before you need it
Due diligence is what won this case in the end. It is established by evidence that you took all reasonable steps in the circumstances. That evidence has to exist before an incident: safety policies, contractor vetting, site inspections, hazard controls, and a record of how you monitored the work.
Keep oversight records on third-party contractors
Hiring an experienced contractor is not a defence on its own. Maintain and document your safety oversight: the requirements you imposed, the inspections you ran, the issues you raised, and how they were resolved. Your level of involvement shapes both your exposure and the strength of your defence.
Match your due diligence to your degree of control
The more control you actually exercise over a worksite, the higher the standard of precaution a court will expect. Calibrate your safety program to your real involvement, and document the precautions that correspond to the control you have.
Define roles and train everyone on site
Make sure each party understands its responsibilities, and extend safety training beyond the primary operators to support and auxiliary staff who work near regulated activities. Clear, documented role definitions reduce both the risk of an incident and the difficulty of defending one.
Document training, inspections, and communications
A contemporaneous paper trail of training sessions, job descriptions, inspections, and safety communications is the raw material of a due diligence defence. Build the habit of recording these as they happen, so the record is there if an investigation or prosecution follows.
If an incident happened on your site tomorrow, could you prove due diligence?
Greater Sudbury shows that owners and employers are within the OHSA's reach, but also that a documented due diligence program can defeat a charge. A proactive review of your safety practices and records is the difference between exposure and a defence.
Book a Compliance Review Or call us: 1-800-771-7882How Achkar Law helps employers
Achkar Law helps Ontario employers stay compliant with the OHSA and reduce the risk of prosecution, whether they oversee employees, contractors, or both. We assist with workplace safety policy development, legal risk assessments and compliance reviews, training and documentation, representation in OHSA investigations and prosecutions, and strategic advice on managing liability across contracted-out work.
Related resources
For another example of how OHSA obligations are enforced and what they require of employers, see our summary of Metrolinx v. Amalgamated Transit Union, Local 1587 (2025 ONCA 415).
For support with safety policies, contractor oversight, and compliance reviews, see our labour and employment compliance services.
Call us at 1-800-771-7882 for a confidential consultation.
The article in this client update provides general information and should not be relied on as legal advice or opinion. This publication is copyrighted by Achkar Law Professional Corporation and may not be photocopied or reproduced in any form, in whole or in part, without the express permission of Achkar Law Professional Corporation. ©