Lucie LaBoissonnière
Lucie LaBoissonnière, Lawyer, McInnes Cooper
Dominique Fontaine
Dominique Fontaine, Lawyer, McInnes Cooper

“Due diligence” is a legal defence to many charges under occupational health and safety (OHS) laws. Here are five of the most frequently-asked questions about the legal defence of due diligence, and practical tips to help you incorporate due diligence in your workplace.

  • What does “due diligence” mean in the context of the legal defence to an OHS charge?

There are both criminal and “strict liability” OHS offences; “due diligence” describes a legal defence to a “strict liability” offence. Criminal conviction typically requires authorities to prove, beyond a reasonable doubt, that the accused both committed the physical act (actus reus) and had the mental intent for the offence (mens rea). “Strict liability” conviction requires authorities to prove beyond a reasonable doubt only that the accused committed the physical act; the accused can then avoid conviction if it proves, on a balance of probabilities (50% or more), it exercised “due diligence”: took all reasonable care that a reasonable person would have taken in the circumstances. “Reasonable care” is a variable standard that depends on the particular circumstances. The appropriate degree of care depends mainly on: the gravity of the potential harm; the alternatives available to the accused; the likelihood of harm; the degree of knowledge or skill expected of the accused; and the extent to which underlying causes of the offence are beyond the accused’s control.

  • Why are due diligence and a culture of workplace safety so important?

Because they help ensure compliance with legal obligations under OHS laws and establish a legal due diligence defence in the event of an OHS charge. They also help accomplish the following that together improve the bottom line: prevent workplace injuries and be prepared for an emergency; increase productivity and employee morale; manage costs, such as lost time and workers’ compensation claims; and maintain public confidence and increase competitiveness.

  • Who has obligations under OHS laws and what are they?

OHS is a shared responsibility: companies and their directors, officers, managers, supervisors and workers personally all have OHS obligations (and liabilities); it’s critical that all read, understand and comply with those that apply. Section 217.1 of the Criminal Code applies to everyone with authority to direct how another person does work or performs a task – including corporate entities and individuals – and imposes the obligation to “take reasonable steps to prevent bodily harm to that person or any other person arising from that work”. OHS legislation and/or regulations typically define and impose various obligations on owners, employers, contractors, subcontractors, suppliers, supervisors and employees:

  • A general obligation on each to take every reasonable precaution to ensure workers’ (or their own) health and safety, or some variation of this wording.
  • More specific duties on each typically relating to compliance with the laws, OHS programs, policies and committees; equipment and tools, including provision, maintenance and inspection; instruction and training; supervision; and record-keeping.
  • Detailed duties and obligations in relation to specific types of work, industries or workplaces.
  • Practically, how do I establish the “due diligence” defence?

By both discharging your duties with respect to a particular occurrence and having evidence you did so. Here are 5 key practical steps to take:

    • Commit. Commit to building a culture of safety, including inviting and allowing employee participation and allocating adequate resources to OHS.
    • Be Aware. Ignorance of the law is no defence. Be aware of all legal duties and industry standards and practices, ensure others are also aware of theirs, keep up with – and act on – changes, and have a system in place to make sure this all happens.
    • Comply. Comply with all applicable laws and discharge all legal obligations and duties under them, have a system in place to require and ensure everyone else does the same, and enforce that requirement.
    • Be Proactive. Take active steps to: foresee specific risks; conduct regular training; develop, implement, review and update policies and procedures; conduct inspections and audits; and promptly act on risks that come up.
    • Document. Written OHS rules alone aren’t enough. Make and keep detailed written records of all OHS-related activities including orientation, training, meetings, inspections and audits, accident investigations and actions to address issues, coaching and disciplinary enforcement of OHS matters, OHS committee meetings, equipment logs and maintenance records, forms and checklists, medical certificates and first aid records, and statistics of accidents and near-misses.
  • When is – and when isn’t – the legal defence of due diligence established?

Here’s a court decision to illustrate when the due diligence defence in the OHS context is established:

In R. v. Thomas Fuller and Sons Ltd., the company used a wooden brace as a makeshift winch system to coax a section of concrete pipe into place. A piece from the brace snapped and hit the contractor’s employee, killing him. The Crown charged the company with violating the OHS legislation by failing, as a constructor, to ensure that every part of the project was designed and constructed to support or resist all loads and forces to which it is likely to be subjected. The court decided the Crown didn’t prove the actus reus but even if it did, the company established “due diligence”:

  • The employer acted reasonably: if proper alignment were maintained, the resistance the wood provided far exceeded the force required to seat the pipe; the winch system was designed and constructed to be, and were, used by experienced pipe fitters under the supervision of a respected and experienced construction supervisor, with the objective of achieving “more stability and flexibility” and no plan to apply greater amounts of force; and the winch system, including the brace, complied materially with the standards the concrete pipe manufacturer identified and the industry long and successfully relied upon.
  • Installation problems: the irregular shaped section used didn’t make it unreasonable to rely on the manufacturer’s manual promising the pipe could be pushed together; the promise failed, not the device. Similarly, it would be reasonable for the company to consult with engineers, put gauges on the device or use steel instead of wood, but a reasonable person wouldn’t, in the circumstances, have been expected to have an engineer design the installation process or calculate forces.

Contrast this with a recent OHS case that sends a clear message: OHS obligations are real and the consequences of failing to meet them grave. In the “Metron” Cases, six workers were returning to the ground on a swing stage. There were only two life lines available; only one worker attached himself. The project manager didn’t encourage or coerce them to travel together, but he knew there were only two life lines and life lines were required by law and an industry standard for workers on such a stage; he wasn’t aware of the stage’s capacity or whether it was properly assembled or installed. The stage failed and the five unattached workers fell to the ground; four died and one survived with serious injuries. The company, and each of its owner/director and the project manager personally, were charged with four counts of criminal negligence causing death and one of criminal negligence causing bodily harm under Criminal Code section 217.1:

  • The owner / director pleaded guilty and agreed to a personal fine of $90,000; the court convicted the company and issued it a $750,000 fine.
  • The court convicted the project manager concluding there was a patent violation of OHS regulations and the industry standard. His failure was to take reasonable steps to prevent the workers from doing something they apparently undertook voluntarily, but knew they shouldn’t do, was enough to breach s. 217.1. The court sentenced him to 3½ years of imprisonment to denounce the conduct and deter others from breaching their s. 217.1 duty.

To discuss this or any other legal issue, contact any member of McInnes Cooper’s Occupational Health & Safety Law Team. Read more McInnes Cooper Legal Publications and subscribe to receive those relevant to your business.

McInnes Cooper prepared this article for information; it is not legal advice.  Consult McInnes Cooper before acting on it. McInnes Cooper excludes all liability for anything contained in or any use of this article. © McInnes Cooper, 2016.  All rights reserved.

About the authors:

Lucie LaBoissonnière and Dominique Fontaine are fully bilingual Labour and Employment lawyers at McInnes Cooper. They regularly provide both unionized and non-unionized employers with strategic employment law advice, and have represented employers in court and arbitration hearings. In particular, they are experienced in advising employers in occupational health and safety matters, including developing and implementing policies and procedures, and have advised and represented employers in workplace accident investigations. You can reach Lucie at and Dominique at