The BC Supreme Court's recent refusal to certify a class action in Davis v British Columbia Hydro and Power Authority re-affirms that although the evidentiary threshold for certifying general causation as a common issue is not high, it is also not non-existent.


As previously discussed, in a 2013 decision, the Supreme Court of Canada rejected the argument that courts must take a "rigorous" approach to class certification and confirmed that plaintiffs need only show a "credible" or "plausible" methodology to try issues of loss or harm on a class-wide basis in price-fixing class actions. Lower courts in BC and Alberta have subsequently extended the requirement to show a "plausible methodology" to causation issues in product liability and brokerage class actions. In particular, according to the BC Court of Appeal, there is no requirement for a "gold standard" study proving a causal connection at the certification stage.

The Smart Meters Class Action

Davis v BC Hydro concerned the introduction of so-called "smart meters" by BC Hydro. In 2011, BC Hydro began replacing existing meters with new "smart meters" that communicated wirelessly. The plaintiffs asserted that the radiofrequency (RF) emissions from smart meters caused biological harm and claimed that legislation making smart meters mandatory infringed the Charter of Rights.

Although the allegation that RF emissions were harmful clearly raised a complex factual issue about the biological effects of RF emissions on humans, the plaintiffs apparently made a tactical decision not to file expert evidence as to how the plaintiffs' allegations could be proven. Instead, the plaintiffs attached copies of certain material asserting the potential adverse health effects of RF emissions and smart meters. In the plaintiffs' submission, it was enough for the plaintiffs to show only the existence of such material to establish a basis in fact for a methodology to prove the proposed common issues on a class-wide basis.

In response, the defendant filed two expert reports describing the multitude of sources of RF emissions, including mobile phones, baby monitors, radios and microwave ovens. The thrust of the defendant's expert evidence was that a class member's exposure to RF emissions from a smart meter would depend on a variety of factors, including the distance from the smart meter, the presence of other sources of RF emissions, and the existence of walls or other barriers between the meter and the individual. The defendant's expert concluded that there were millions of exposure scenarios to be considered and a large variation in RF exposure levels.

The court found that the defendant's expert evidence was unchallenged because the plaintiffs' evidence was not admissible to show a methodology by which the biological effects of smart meter RF emissions could be plausibly proved on a class-wide basis. The plaintiffs therefore failed to meet their evidentiary burden to show there were common issues. Indeed, the certification motion judge described the failure to lead admissible evidence as a "fundamental problem for the plaintiffs".

Key Takeaway

The BC courts have issued a series of decisions applying the Supreme Court's "credible or plausible" methodology requirement to cases involving allegedly harmful products. At this stage the takeaway from these cases can be succinctly summarized as follows: some evidence of a methodology showing the potential harmfulness of products is required at certification, but it need not rise to the level of a "gold standard" medical study.

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