Does having a certified occupational health and safety management system lead to a greater injury rate reduction? An evaluation of the Certificate of Recognition program in Ontario, Canada

22nd Mar 2026

Does OHS system certification impact incident measures at the industry level?

Here’s another study which explored these links – this time using the Canadian Certificate of Recognition (COR) program.

346 certified firms were matched with 310 non-certified over 2009-2020.

Full PDF shared under an Open Access licence.

Findings:
·        “Firms that became certified were associated with a greater reduction in the lost time injury rate (incidence rate ratio (IRR): 0.72; 95% confidence interval (CI): 0.63–0.84) [and] high-impact injury rate (IRR: 0.80, 95% CI: 0.66–0.97)”

·        But there was “no reduction in the no lost time injury rate (IRR: 1.00, 95% CI: 0.92–1.08) relative to the change in similar non-certified firms”

·        “The effectiveness of certification was strongest in firms that were recently certified, larger, and in the construction sector”

·        “The findings suggest that COR can be an effective program in reducing injury rates in construction firms, and among larger and more recently certified firms”

·        “It is less effective in smaller and earlier certified firms, and not effective in non-construction firms”

·        “While effectiveness was observed in the construction sector, the findings may be subject to unmeasured selection bias due to the increasing role that COR has had as a pre-bid requirement for publicly-funded infrastructure projects”

·        “The difference in effectiveness of certification on lost time and high-impact injury rates compared to no lost time injury rates indicates that other work-related injury measures need to be examined”

·        “The difference in effectiveness of certification by size of firm suggests that smaller firms do not benefit from the program to the same degree as larger firms”

Ref: Macpherson, R. A., & McLeod, C. B. (2026. Journal of Safety Research, 97, 1-8.