Alexander Johnstone v Fawcett's Garage (Newbury) Limited

In a mesothelioma claim governed by the special causation rule, the claimant need establish that the defendant’s breach materially increased the risk of contracting the disease. Proof that the exposure probably caused the disease is unnecessary. Materiality is a fact-sensitive de minimis assessment, with no fixed quantitative threshold or doubling-of-risk requirement. A court may compare tortious risk with background risk using epidemiological, statistical, occupational-hygiene and medical evidence, provided it proceeds cautiously. An absolute-risk approach, asking only whether the tortious dose is medically insignificant, is inappropriate because it prevents proper attribution and makes the required increase in risk immaterial. Missing monitoring records do not require uncritical acceptance of an expert’s calculations or the disregard of factual findings.

Elaine Johnstone worked in an office at a garage between 1982 and 1989. The garage admitted unsafe asbestos-generating practices in its workshop and breach of duty, but denied that the exposure materially increased her risk of mesothelioma. After a five-day trial, the High Court, in [2023] EWHC 3010 (KB), assessed her exposure at approximately 0.001 to 0.002 f/ml-y and concluded that the resulting increase in risk was 0.1% or less, which was immaterial.

The appellant challenged the treatment of expert evidence, the calculation of background risk, the direct risk assessment methodology, the adequacy of the judge’s reasons, and the refusal to draw an adverse inference from missing air-monitoring records. The respondent’s notice relied on an alternative absolute-risk approach. The central issues concerned the proper assessment of material increase in risk and the limits of adverse inferences on appeal.

The appeal was dismissed in a unanimous joint judgment.

1. Adverse inference. The principles in [1972] AC 877, [2010] EWCA Civ 683, [2012] EWHC 1150 (QB) and [2019] EWCA Civ 2110 are fact-sensitive. The absence of air-monitoring records did not require the judge to prefer the appellant’s higher exposure calculations. The obligation under the Control of Asbestos at Work Regulations 1987 had not been shown to require retention of the records for 30 years. On the evidence, any relevant records would ordinarily have been retained for five years and would have expired long before trial. The proposed inference was also confined to a small part of the employment period and depended on hypothetical records concerning a third party. It could not require the judge to disregard findings based on the evidence of the appellant’s own witness.
2. Causation and materiality. The special mesothelioma rule requires a material increase in risk. The court adopted the approach in [2011] UKSC 10 and [2002] UKHL 22 that materiality is a factual de minimis question. It need not be quantified by a fixed threshold, and exposure need not double the risk. The judge was entitled to assess risk directly by comparing the known occupational risk with background risk and using expert epidemiological and medical evidence.
3. Ground 2. The judge had failed to carry through Professor Jones’s revised range for background risk. Even using the revised figures in the ways properly advanced, the calculated increase remained below, or only marginally above, 0.1%. The argument based on selecting the most favourable ends of both risk ranges was raised too late and had not been addressed below.
4. Absolute risk. The respondent’s alternative approach was rejected. Asking only whether the tortious exposure was medically insignificant failed to attribute the tortious contribution to the total risk, rendered the word increase ineffective, and could defeat a claim despite a substantial relative increase in risk. Materiality remained a matter for the judge, not a question delegated to a medical expert. The Court of Appeal was not bound by [2020] EWHC 1256 (QB).
5. Appellate review. The judge’s factual and expert-evidence conclusions were open to him. They were not plainly wrong or irrationally insupportable. Grounds 1 to 5 and the respondent’s notice therefore failed.

1. Court of Appeal (Civil Division). The appeal and respondent’s notice were dismissed. The court upheld the High Court’s conclusion that the defendant’s breach had not caused a material increase in the risk of mesothelioma: [2025] EWCA Civ 467 .
2. High Court of Justice, King’s Bench Division. His Honour Judge Simon found breach of duty but concluded that the increase in risk was 0.1% or less and therefore immaterial: [2023] EWHC 3010 (KB) .