The Court of Appeal has recently decided that the Fairchild causation exception applies in a lung cancer case. The case is significant in that to date the Fairchild exception has only been applied to mesothelioma claims, and this is the first time the Court of Appeal has been asked to consider its application to a lung cancer case.

It remains to be seen how the Courts now interpret this decision and whether the Fairchild enclave is now set to experience a period of rapid expansion but it does appear that, where medical science cannot prove that a defendant has materially contributed to a disease, but can prove that a defendant has materially increased the risk of contracting the disease, the Fairchild exception may be applied to establish the necessary causation, and liability will be proportionate to the increase in risk for which the defendant was responsible. 


In Carl Heneghan (Son & Executor of James Leo Heneghan, Deceased) v Manchester Dry Docks Ltd & Ors [2016] EWCA Civ 86, the claimant was the son and executor of the deceased, Mr Heneghan, and his widow. Mr Heneghan had died of lung cancer. It was common ground that his lung cancer was caused by exposure to asbestos fibres. He had been exposed to asbestos in the course of his employment with each of the six defendants. Other employers who had exposed Mr Heneghan to asbestos were not sued in these proceedings. It was also accepted that biological evidence could not establish which of the exposures, if any, triggered the cell changes in his body which led to the cancer. However, evidence could establish by how much the exposure by each defendant had increased the risk that he would contract the disease.

The question for the Court was how it should deal with causation (and therefore apportionment of damages) in these circumstances.

First instance decision

Mr Justice Jay concluded that the causation test established in Fairchild v Glenhaven Funeral Services was applicable, qualified by Barker v Corus. Fairchild concerned mesothelioma, and the Court had found that causation could be established for the purposes of liability for mesothelioma if a defendant employer had materially increased the risk that a victim would contract the disease. Barker established that, where a person was so responsible, it was not liable for all the damage attributable to the mesothelioma, but only in proportion to its contribution to the risk. Applying these principles, Jay J awarded damages against each defendant that were proportional to the increase in risk for which it was responsible. This meant they were only responsible for 35.2% of the total damages claimed. The Compensation Act 2006 was not applicable in this case because the relevant part of the Act applies only to mesothelioma claims and hence the pro-rata allocation of damages in this case. The claimant appealed against the decision at first instance.

Court of Appeal decision

The appellant contended that there was evidence to show that each of the defendants had materially contributed to Mr Heneghan’s lung cancer, rather than just the risk of its contraction. Therefore the position was distinguishable from the multi-employer mesothelioma case where the claimant cannot prove that each defendant materially contributed to the disease itself because of the indivisible nature of mesothelioma, including that its severity does not increase with exposure.

Lord Dyson, giving the leading judgment in the Court of Appeal, accepted the following:

  • the lung cancer had been caused by Mr Heneghan’s exposure to asbestos;
  • the causal connection between the lung cancer and asbestos was established by reason of the cumulative dose; and
  • the asbestos acted in multiple ways to promote carcinogenesis at cellular level.

He did not, however, accept the following arguments made by the appellant:

  • the asbestos from each defendant was likely to have been inhaled and distributed in the lungs in a similar way;
  • the fibres from each source were likely to have played a part in the carcinogenic process; and
  • each defendant therefore materially contributed to the contraction of the disease.

The appellant's arguments would have allowed a recovery in full from six defendant employers even though they were only responsible for 35.2% of the total exposure to which Mr Heneghan was subjected. Thus on the facts of this case it was the defendant employers who were arguing for the Fairchild exception on causation to be applied to the claim.

Lord Dyson introduced his analysis with a helpful recap of the three ways in which causation could be established in disease cases:

  • Causation will be established if, but for the defendant’s negligence, the claimant would not have suffered the disease.
  • Where the disease is caused by the cumulative effect of an agency (e.g. asbestos fibres) part of which is attributable to the breach of duty on the part of the defendant and part of which involves no breach of duty, the defendant is liable on the basis that his breach made a material contribution to the disease (per Bonnington Castings v Wardlaw in which the victim contracted pneumoconiosis from exposure to silica dust).
  • If causation cannot be proved in these ways (for example if a disease is indivisible) causation may be proved if the defendant materially increased the risk of the victim contracting the disease (the Fairchild exception).

It was accepted by the appellant that the “but for” test was not satisfied. He contended, however, that this was a Bonnington scenario because the exposure attributable to each defendant contributed to the disease itself (rather than the risk of contraction).

The judge at first instance had accepted that lung cancer was dose related. However, unlike pneumoconiosis where the greater the accumulation of dust in the lungs, the greater the damage being caused to the lung tissue, in the case of lung cancer and asbestos the greater the exposure to asbestos fibres, the greater the risk that lung cancer may result. Epidemiology could not, however, establish whether the fibres to which Mr Heneghan was exposed by each defendant actually caused the fatal disease. Jay J concluded: “In lung cancer cases, there is no analogue to the gradual accumulation in the lungs of asbestos or cigarette smoke. The risk of the disease eventuating is proportionate to the quantum of exposure, but that is a statistical judgment, not an assessment which may be linked to the physical presence of deposits of dust in the lung.”

Lord Dyson agreed with Jay J’s decision to reject the opinion of the appellant’s medical expert that every period of exposure contributed to the development of Mr Heneghan’s cancer. This was not a medical opinion. Rather it was an opinion that an inference of causation could be drawn from the epidemiological evidence. The epidemiological evidence enabled the quantification of the contribution to the risk of cancer attributable to an individual defendant. It went no further than that. It was not possible to say which factor actually caused the cancer. As to this, the appellant’s expert accepted that the current understanding of biological mechanisms does not form a basis for the practical attribution and apportionment of particular cancers.

Lord Dyson held that the appellant’s contention that Bonnington should apply “ignores the fact that there is a fundamental difference between making a material contribution to an injury and materially increasing the risk of an injury” (emphasis added). He remarked that, if the two were the same thing Fairchild would not have been the ground-breaking decision that it was when it introduced, in the words of Lord Hoffman in Barker, “an exceptional and less demanding test for the necessary causal link between the defendant’s conduct and the damage” than the claimant having to prove that the defendant did in fact cause the damage. The Bonnington test was to be applied where the Court is satisfied on scientific evidence that the exposure for which the defendant is responsible has in fact contributed to the injury. It would therefore typically be applicable to divisible injuries such as silicosis, where the severity of the disease was proportionate to the amount of exposure. Where scientific evidence does not enable the Court to determine whether the exposure has in fact contributed to the injury, the law has responded by applying the Fairchild test so as to avoid an unfair result. Lord Dyson was satisfied that all the factors required for the application of the Fairchild solution were satisfied, namely that:

  • all the defendants admitted breach of duty;
  • all the defendants increased the risk that Mr Heneghan would contract lung cancer;
  • all exposed Mr Heneghan to the same agency (asbestos fibres) that was implicated in the causation; but
  • medical science was not able to determine which (if any) of the defendants was responsible for the exposure which actually caused the cell changes which caused the cancer.

He therefore saw no reason not to apply the Fairchild exception to this lung cancer case and, indeed, commented that to not apply the case would make the law in this area “inconsistent and incoherent”. He referred to the recent decision of the Supreme Court in International Energy Group v Zurich Insurance Plc UK in which Lords Neuberger and Reed said that the Fairchild exception is “applicable to any disease which has the unusual features of mesothelioma”. Accordingly he dismissed the appeal. The effect of applying the Fairchild exception was that the claimant was unable to recover from the six defendant employers any more than their pro-rata proportion (totalling 35.2%) of the damages claimed.


The decision confirms that the Courts are willing to apply the exceptional principle established in Fairchild to diseases other than mesothelioma provided that the facts of a case are truly analogous to those in Fairchild. It appears that, where medical science cannot prove that a defendant has materially contributed to a disease, but can prove that a defendant has materially increased the risk of contracting the disease, Fairchild may be applied to establish the necessary causation. The Courts will not, however, apply Bonnington unless there is medical evidence to prove that a defendant has materially contributed to the disease itself. It remains to be seen how the Courts now interpret the decision and whether the Fairchild enclave is now set to experience a period of rapid expansion.

David Reston
David Reston
Partner, dispute resolution
+44 20 7466 2244
Antonia Pegden
Antonia Pegden
Associate, dispute resolution
+44 20 7466 2530