Karen Sienkiewicz v Greif (UK) Ltd: Knowsley Metropolitan Borough Council v Willmore SC concerned appeals against the appropriate rule of causation in cases of mesothelioma involving a single defendant.
The Court of Appeal had applied the principle in Fairchild v Glenhaven Funeral Services Ltd and Barker v Corus UK Ltd of “materially increasing the risk” of harm. The defendants were found responsible for exposing the victims to sufficient asbestos dust to create a material increase in risk and therefore jointly and severally liable.
The defendants appealed and the Supreme Court dismissed their appeal, finding that:
- The special rules of causation in Fairchild and Barker had been devised because it was impossible for a Claimant to prove causation according to the conventional ‘but for’ test due to the uncertainty about the biological cause of the disease.
- Liability for mesothelioma fell on anyone who had materially increased the risk of the victim contracting the disease.
- The insertion of the word ‘material’ was intended to exclude an increase of risk that was so insignificant that the court would properly disregard it on the de minimis principle.
- What was de minimis was a question for the judge on the facts of any particular case.
- In the case of mesothelioma, a stage had to be reached at which, even allowing for the possibility that exposure to asbestos could have a cumulative effect, a particular exposure was too insignificant to be taken into account, having regard to the overall exposure that had taken place.
- The adoption of the special rule of causation set out in Fairchild and Barker was justified in cases where there was one defendant.