An Ontario appeal court has overturned a conviction under the Occupational Health and Safety Act because there was no basis for concluding that the collapse of an overhead duct was a foreseeable risk.  The accident could not have been expected.

Employees were removing ducts and other equipment from a non-operational foundry in Woodstock, Ontario, in order to transport it to the United States.  A large section of the duct work collapsed and seriously injured a worker.

What had happened, the court concluded, was that sand had built up in the ducts and caused them to collapse.  The evidence was that the build up should not have occurred and could not have been expected.  Witnesses gave uncontradicted evidence that it was not practical or reasonable to inspect all welds in the ducts as it would have taken years to do so.  But for a poor weld and the sand build up, the collapse would not have happened.

The appeal court held that the “foreseeability of the effect” was one of the factors to be considered in determining whether the employer had exercised due diligence.  Here, the sand build up and collapse were not foreseeable, and the charges were dismissed.

The decision is a reminder that not all workplace accidents justify charges under the Occupational Health and Safety Act.  As our recent prosecutions study indicated, only 6% of corporations take their OHSA charges all the way to trial, so there is minimal caselaw. This decision will assist employers in understanding the scope of the due diligence defence.

R. v. Rassaun Steel & MFG. Co. Ltd., 2012 ONCJ 705 (CanLII)