Due Diligence and Why It’s Important

by | Jan 15, 2018 | For Employers

Employers have various obligations under the Occupational Health and Safety Act (“the OHSA”), including the very broad, catch-all duty to take every reasonable precaution in the circumstances to protect workers.

When there is a workplace accident, the Ministry of Labour will often charge the employer with violating this general duty. Violations of the OHSA are “strict liability” offences, which means that the Ministry of Labour does not need to prove that the employer intended to violate the OHSA.

An employer’s sole defence is the “due diligence” defence, which is available in two circumstances:

  1. If the accused reasonably believed in a mistaken set of facts which if true, would render the act or omission innocent; or
  2. If the accused took all reasonable steps to avoid the particular event.

In Ontario (Ministry of Labour) v Cobra Float Service Inc., an Ontario court dismissed an OHSA charge by finding that the employer had established the due diligence defence.


The circumstances around this case arose from a tragic fatality at a construction site, where a curb machine overturned while being off-loaded from a float trailer, crushing a worker who later died from his injuries. The charge against the company alleged that the curb machine was moved in a manner that endangered the worker.


The court found that the worker had deviated from the standard practice that he and other workers had followed on previous occasions. Although there were no training courses available for the task in question, the worker had previously demonstrated his ability to perform the task. The court found that the employer was entitled to rely on the worker’s experience.

The court noted that the employer could have established a more formalised training protocol within the company but the lack of this formalised protocol did not necessarily mean that the employer was exposing workers to foreseeable risks and dangers. The court cautioned against measuring the practices of smaller companies against those of larger companies, which typically have more resources to devote to formalised training.

With respect to the due diligence defence, the court found that:

  • The company had held regular safety meetings;
  • There were no formal education courses that workers could take on the loading and unloading task;
  • The worker knew or should have known that what he was doing was unsafe;
  • The company encouraged workers to discuss any safety concerns and provided a form for those discussions at regularly scheduled meetings;
  • The worker had successfully moved the curb machine 27 times; and
  • There was no evidence that this was an industry-wide safety issue.

Lessons to be Learned

  1. Because violations of the OHSA are “strict liability” offences, the Ministry of Labour does not need to prove that the employer intended to violate the OHSA.
  2. Evidence regarding a company’s safety practices go a long way to proving that the employer took all reasonable steps to avoid the particular workplace accident (i.e. to make out the due diligence defence).
  3. All employers should prioritize safety, but it is worth noting that what is appropriate for a small to medium size employer may differ than what is appropriate for a larger employer.

The material and information in this blog and this website are for general information only. They should not be relied on as legal advice or opinion. The authors make no claims, promises, or guarantees about the accuracy, completeness, or adequacy of any information referred to in this blog or its links. No person should act or refrain from acting in reliance on any information found on this website or blog. Readers should obtain appropriate professional advice from a lawyer duly licensed in the relevant jurisdiction. These materials do not create a lawyer-client relationship between you and any of the authors or the MacLeod Law Firm.



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