Northern Exposure

Occupational health and safety due diligence defense alive and well

by Rosalind H. Cooper

A recent case involving charges against a company under the Ontario Occupational Health and Safety Act has confirmed that the defense of due diligence is alive and well. The defense of due diligence—which may allow employers to avoid a conviction under occupational health and safety legislation—can be difficult to establish. Even in cases where a worker is injured as a result of his or her own misconduct, the defense cannot always be made out. But in the right factual circumstances, it is still possible to successfully advance the due diligence defense notwithstanding the high standard applied.


The case of R. v. ABS Machining Inc. involved an accident that took place at the Mississauga facility of ABS Machining Inc. ABS produces machined metal products and had received an order to manufacture certain metal components for trucks used in the oil industry. The components are called “rear spindles” and each one weighs about 10,000 pounds and is 4-5 feet long.

During the manufacturing of these spindles, ABS received notice from the buyer to make a modification to one of the spindles being produced. Since the spindle had already been machined, it was necessary to make the modification by hand.

The work was assigned to a relatively inexperienced worker who had been employed by ABS for 17 months. In order to access the necessary part of the spindle, it had to be rotated. The worker used an overhead crane for this purpose. His supervisor had not told him to rotate the spindle and had asked him to wait. But the worker proceeded with the rotation before the supervisor’s arrival. While doing so, the spindle fell onto the worker’s right foot, which had to be amputated.


The Ministry of Labour charged ABS with two counts under the Occupational Health and Safety Act:

1. The first charge was for failing, as an employer, to ensure that measures and procedures prescribed by the industrial regulations were carried out at the workplace. The ministry alleged that the employer had failed to ensure that the spindles were lifted and/or carried and/or moved in such a way and/or with such precautions and/or safeguards that did not endanger the safety of the worker.

2. The second charge was that ABS committed the offense of failing, as an employer, to provide information, instruction, and supervision to a worker to protect the health and safety of the worker by not providing information and/or instruction and/or supervision to a worker on how to move the spindle safely.

Due diligence defense

In assessing whether the defense of due diligence was made out, the court decided that it is necessary to inquire into:

(a) whether what transpired was reasonably foreseeable; and
(b) ABS’s safety training and procedures.

In reviewing the facts, the court concluded there was no procedure for rotating the spindle, nor had there ever been a need to do so until the change in order by the buyer. The court also concluded that the worker (who claimed that he was told to rotate the spindle) was not credible. The supervisor gave evidence that, because the spindle was a very heavy piece of equipment, there was no expectation that a junior worker would be responsible for rotating it. Instead, as the senior employee on the job, the supervisor would have that responsibility.

In terms of the due diligence defense, the court said that it was insufficient for an employer to merely point to a worker’s negligent, careless, or even reckless conduct to successfully rely upon the due diligence defense. The court framed the issue as one of foreseeability and considered whether a reasonable employer should have foreseen the worker attempting to rotate the spindle. The court concluded that a reasonable employer would not have foreseen that a worker would undertake to rotate the spindle on his own and in the manner that he did.


This case confirms that, in situations where a worker proceeds to undertake work that he or she is clearly not authorized or directed to conduct, the defense of due diligence will be available. Given that due diligence is available to employers in all provinces, this case should assist employers right across Canada.