Amaca Pty Ltd v Ellis

This case involved appeals by Amaca Pty Ltd and others against decisions of the Court of Appeal concerning claims for damages for lung cancer allegedly caused by exposure to asbestos fibres during employment, compounded by the deceased's smoking habits. The High Court of Australia was required to determine whether the evidence presented established, on the balance of probabilities, that exposure to asbestos was a cause of the deceased's lung cancer.

The central legal issue was the application of the "more probable than not" standard of proof in cases of causation where scientific certainty is unattainable. The court had to consider whether epidemiological evidence, which demonstrated increased relative risks and potential synergistic effects between smoking and asbestos exposure, was sufficient to infer that asbestos exposure caused or materially contributed to the deceased's lung cancer in an individual case. The court noted that simply showing that asbestos exposure may have been a cause, or that a small percentage of lung cancer cases are attributable to asbestos, was insufficient without more to establish causation in a particular instance.

The High Court reasoned that while courts must resolve questions of causation despite scientific uncertainty, this requires more than merely identifying a potential cause or a statistical possibility. The court emphasised that the evidence must demonstrate that it was more probable than not that the exposure to asbestos was a cause of the deceased's lung cancer. The epidemiological evidence, while informative about general risks, did not, in the absence of further specific evidence linking the individual's condition to the exposure on the balance of probabilities, satisfy this threshold.

Consequently, the High Court allowed each appeal with costs. The court also provided directions for the parties to file proposed amended notices of appeal and to submit agreed minutes or written submissions regarding consequential orders to be made by the Court.