In a unanimous judgment handed down by the Supreme Court, it has been held that in a “low dose” exposure claim, a mesothelioma victim need not establish that the extent of his exposure was such that it “doubled the risk” of him contracting the disease. Therefore, any exposure greater than de minimis exposure constituted negligent exposure - Sienkiewicz v Greif (UK) Ltd; Willmore v Knowsley Metropolitan Borough Council 09.03.11.

In Sienkiewicz the deceased had worked in an office within the Defendant’s factory. Her duties occasionally necessitated her visiting parts of the factory thought to have contained asbestos. She was also a resident of Ellesmere Port and as such she was likely to have sustained background exposure to asbestos environmentally. At first instance, the trial Judge accepted the Defendant’s contention that in order to succeed, the Claimant would have to establish that her occupational exposure had at least “doubled the risk” of her contracting mesothelioma. This decision was reversed in the Court of Appeal on the basis that the effect of Fairchild v Glenhaven Funeral Services Ltd and others [2002] and s.3 of the Compensation Act 2006 was that a tortfeasor was liable for a mesothelioma where the exposure had materially increased the risk of it developing. Whilst Fairchild had involved claims against multiple employers, this decision indicated that, in a claim against a single defendant, the Fairchild test would still be applied.

In Willmore, the Claimant had low dose exposure during the period she attended her local school. The trial Judge decided that the Claimant’s exposure had been greater than de minimis and, relying on Fairchild, found that the local authority had been in breach of its duty. The Defendant’s appeal to the Court of Appeal was unsuccessful.

Supreme Court

  • In his leading judgment, Lord Phillips concluded that on the basis of current medical knowledge, epidemiological evidence alone is not a satisfactory basis for making findings of causation and thus the concept of “doubling the risk” was flawed.
  • Lord Rodger confirmed, following on from the findings of Lord Phillips, that although Fairchild had been decided in the context of multiple exposures, this exception would still apply in single exposure cases. In determining “material exposure” the level of exposure in both of the cases under appeal was greater than de minimis. A claimant will succeed where his occupational exposure was greater than de minimis, even if that exposure was less than the background environmental level.
  • In a sympathetic judgment, Lord Brown recognised that “there is a rough justice about the law of personal injury liability as a whole”. He observed that mesothelioma claims are in a category of their own and that the “die was inexorably cast in Fairchild”. Whilst it was acknowledged that the Court had been very generous to Mrs Willmore in finding material exposure, Lord Brown added that from a defendant’s standpoint, resisting a mesothelioma claim must be regarded as “a lost cause”.


Defendants and their insurers will be concerned that this decision could generate claims from claimants who have had minimal exposure. Asbestos and asbestos building products were used extensively in the construction of buildings throughout the 1950s and up until the early 1970s. Such asbestos commonly remained in place until it was removed during the 1980s.

It is arguable that the Supreme Court, in failing to add an additional burden of proof for such claimants, has left defendants potentially vulnerable to speculative claims and defendants will be unlikely to defend claims even where they can show relatively minor or infrequent exposure.

The factual judgment in Willmore is also a concern to defendants, given the speculative basis upon which the Defendant was found liable, bearing in mind the fleeting exposure to the Claimant.

On a positive note, the judgment will not impact upon defendants seeking contributions from other potential tortfeasors, and may lead to claims that might previously have been disregarded due to the de minimis principle, now being successfully brought.

For more background, view our reports on the Court of Appeal decisions on Sienkiewicz and Willmore