Sienkiewicz v Greif (UK) Ltd

Factual and Procedural Background

These conjoined appeals concern two mesothelioma claims decided by the United Kingdom Supreme Court.

• Plaintiff A (administrator of the estate of the late Mrs C) sued Defendant A (her former employer) alleging that very light occupational exposure to asbestos between 1966 and 1984 materially increased her risk of contracting mesothelioma. The trial judge dismissed the claim, holding that the exposure augmented the background (environmental) risk by only 18 % and did not “double” it. The Court of Appeal reversed, applying the mesothelioma causation rule derived from Fairchild and section 3 of the Compensation Act 2006.
• Plaintiff B (widower and administrator of the late Mrs W) sued Defendant B (the education authority which ran her secondary school). The claim alleged exposure to asbestos-containing ceiling tiles while she was a pupil in the 1970s. The trial judge found three routes of exposure, each non-de minimis, and awarded agreed damages. The Court of Appeal upheld liability on two of the three routes.
• Both defendants appealed to the Supreme Court. Their appeals were heard together because they raised common questions about the scope of the special rule of causation applicable to mesothelioma.

Legal Issues Presented

1. Does the Fairchild/Barker rule of causation apply where the defendant is the sole alleged occupational source of asbestos exposure and the only other exposure is environmental?
2. Can a defendant defeat liability by showing, through epidemiological evidence, that its exposure did not “more than double” the background risk of mesothelioma?
3. What constitutes a “material increase in risk” for the purposes of the special mesothelioma rule?
4. In the school exposure case, were the judge’s factual findings of non-de minimis exposure open to challenge?

Arguments of the Parties

Defendants’ Arguments

• The special rule in Fairchild should be confined to cases involving multiple tortious exposures; where there is only one tortfeasor, conventional “but-for” causation must be proved.
• Causation can (and must) be established by epidemiology using the “doubles the risk” test; because occupational exposure increased risk by only 18 %, Plaintiffs A and B should fail.
• Alternatively, an exposure is not “material” unless it at least doubles environmental exposure; the exposures found by the courts below were de minimis.
• In Plaintiff B’s case, the trial judge’s findings on the extent and routes of exposure were unsustainable on the evidence.

Plaintiffs’ Arguments

• The Fairchild rule, as confirmed by section 3 of the 2006 Act, applies in every mesothelioma case where the defendant’s breach of duty materially increased risk, irrespective of whether other exposures were tortious, non-tortious or environmental.
• The “doubles the risk” test is alien to the special rule and would re-introduce the very proof difficulties which that rule was designed to remove.
• An exposure is “material” if it is more than trivial; there is no quantitative threshold such as “doubling”.
• The judge’s factual findings in Plaintiff B’s case were open to him and were properly upheld by the Court of Appeal.

Table of Precedents Cited

Court’s Reasoning and Analysis

The Supreme Court (majority and concurring opinions) reasoned as follows:

• The scientific “rock of uncertainty” that prompted Fairchild remains; it is still impossible to identify, even on balance of probability, which asbestos fibre initiated the disease.
• The special rule is engaged whenever a defendant’s breach materially increases mesothelioma risk, regardless of whether the other exposure is environmental or lawful: Lord Hoffmann’s dictum in Barker (para 17) was endorsed.
• Epidemiological or statistical evidence alone cannot displace the policy-driven Fairchild rule; statistics speak to populations, not individual causal proof. The “doubles the risk” concept is therefore irrelevant in mesothelioma litigation.
• Materiality is a qualitative, not quantitative, concept: any exposure beyond the de minimis range meets the threshold; imposing a 100 % (doubling) threshold would contradict Fairchild.
• Section 3 of the 2006 Act does not dictate causation rules; it merely fixes the quantum consequence (joint and several liability) once liability is established.
• On the facts, the occupational/school exposures in both cases, although light, were plainly more than de minimis, and the trial findings (as pruned by the Court of Appeal in Plaintiff B’s case) were unimpeachable.
• Lords Brown and Hale added strong caveats: the mesothelioma causation rule is sui generis and should not be extended to other tort contexts; courts must resist lax factual inference.

Holding and Implications

Holding: Both appeals were DISMISSED. The Fairchild/Barker causation principle applies even where the defendant is the sole tortious source of asbestos exposure and the only competing exposure is environmental. The “doubles the risk” test is inapplicable to mesothelioma claims. Each defendant remains jointly and severally liable for full damages.

Implications:

• Victims need show only a non-trivial increase in risk to establish causation against a negligent exposure defendant, even in single-defendant cases.
• Defendants cannot defeat liability by relying on epidemiological arguments that their exposure did not double ambient risk.
• The judgment reinforces that the mesothelioma rule is exceptional and policy-driven; courts cautioned against extending similar relaxations of causation to other tortious contexts.
• No new precedent beyond mesothelioma was created, but the decision clarifies the reach of the special rule and the limited role of statistical proof in such claims.