Certification to OHSAS 18001 is associated with subsequently enhanced safety improvement, according to a recent US study funded by Harvard Business School.
This study used annual BLS incident data from >230k establishments and data from 10 major international certification bodies spanning 1995 to 2016.
The authors used a longitudinal design and control group of non-certified establishments.
Overall they found that:
· Certified establishments subsequently had 20- percent fewer injury and illness cases than the matched control group over the next six years
· OHSAS 18001 certification also led to improved safety performance after certification
· Not unexpectedly, US establishments that became certified tended to be already safer than non-certified
· Each additional injury/illness case was associated with a 21% decline in the odds of becoming certified
· Each additional case of days away from work was associated with a 36% decline in the odds of becoming certified
They state that this “positive selection effect indicates that OHSAS 18001 certification is a credible signal of ex ante superior safety performance”.
They also found “some evidence that OHSAS 18001 also reduces the most severe injuries and illnesses—those that lead to days away from work—by a similar magnitude”, but the precision of this estimate may be more variable.
They speculate whether “Cost-constrained regulatory agencies like U.S. OSHA and its state-level counterparts should consider whether to reduce scrutiny over OHSAS 18001 certified establishments and divert monitoring resources elsewhere”.
These findings are said to “complement studies that found safety to be a spillover benefit of becoming certified to ISO quality management system standards”.
Several limitations were present: 1) they couldn’t test the mechanisms that certification improves performance, 2) the data was quantitative, with little to no qualitative to inform the numbers, 3) data is US only, 4) injury/Illness data is legally mandated self-reported BLS data, which may have issues with underreporting of minor incidents.
They speculate that these findings are likely to be relevant to ISO 45001.
Ref: Viswanathan, K., Johnson, M. S., & Toffel, M. W. (2022). Harvard Business School Technology & Operations Mgt. Unit Working Paper, (22-042).
Study link: https://dx.doi.org/10.2139/ssrn.3988416
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