Arbitrator erred in demanding scientific certainty from employer during pandemic
Employers don't need to get the science right when implementing workplace health policies during a pandemic — they just need to act reasonably based on available public health guidance.
That's the key message from the BC Court of Appeal's Jan. 9, 2026 decision to overturn a labour arbitrator who found Purolator's COVID-19 vaccination mandate unreasonable after June 2022.
In reasons written by Justice Harris, the court ruled the arbitrator wrongly held Purolator to a standard of scientific correctness rather than asking whether the employer acted reasonably given conflicting expert opinions and evolving public health advice.
When scientific certainty isn't required
Purolator implemented its COVID-19 Safer Workplace Policy in September 2021, requiring all employees to attest to being fully vaccinated by Jan. 10, 2022. The policy remained in place until May 2023 but didn't require booster shots after the initial two doses.
The arbitrator found the policy reasonable when first implemented but concluded it became unreasonable by late June 2022. His reasoning: scientific studies showed two-dose vaccination after 25 weeks provided only 9% average effectiveness against Omicron infection, which he characterized as “statistically insignificant” and “effectively useless.”
The Court of Appeal disagreed with this approach. Justice Harris wrote: "In that context, the relevant question is what steps are reasonable, not what steps can be objectively demonstrated to be correct."
‘Considered opinion’ from PHO
A critical issue involved how the arbitrator treated public health guidance from Dr. Bonnie Henry, BC's Provincial Health Officer. Her September 2022 order stated that “an unvaccinated person is more likely to become infected than a vaccinated person and is more likely to transmit SARS-CoV-2 than a vaccinated person.”
The arbitrator dismissed this guidance as running “entirely contrary to the overwhelming prevailing medical opinion” and called it an “outlier” and “isolated and contrarian message.”
The Court of Appeal found this characterization unreasonable. The court noted Dr. Henry's “considered opinion” as a provincial health officer “charged with onerous responsibilities to act in the public interest” cannot be dismissed as contrarian or marginal.
Reasonableness in face of uncertainty
The court found the arbitrator's reasoning internally inconsistent. Earlier in his decision, he had accepted that Purolator acted reasonably in February 2022 despite conflicting scientific evidence because “uncertainty and the precautionary principle still operated in favour of continuing the mandate.” Yet by September 2022, when Dr. Henry's order demonstrated continuing uncertainty among public health authorities, the arbitrator concluded there was “no longer any scientific uncertainty.”
Justice Harris found this conclusion unsupportable on the record, emphasizing: “It was on this basis that the arbitrator concluded the SWP was reasonable when first implemented, and continued to be reasonable in February 2022, because sufficient data had not yet become accessible to demonstrate that vaccination was no longer effective to protect against infection.”
The award was set aside and the grievance remitted to a new arbitrator for fresh consideration.
See Purolator Canada Inc. v. Canada Council of Teamsters, 2026 BCCA 3
