The case of Fairchild v Glenhaven Funeral Services Ltd and Others  UKHL 22 is a major development in the area of causation in tort law. The House of Lords here decided that in a case where employees had contracted mesothelioma due to asbestos exposure throughout the course of their employment, but where science could not determine which of those employers was the sole cause of their disease, they could recover damages against each employer who exposed them to asbestos dust in breach of their duty of care.
This decision modified the traditional ‘but for’ test for factual causation and suggested that as long as each employer’s wrongdoing had materially increased the risk of contracting mesothelioma, the claimants had proved, on a balance of probabilities, the necessary causal requirement.
One could argue that this case has provided a pragmatic solution to the inherent harshness of the ‘but for’ test. This was espoused by the Supreme Court of Canada in Clements v Clements 46 DLR 4th 577 at paragraph 13 which stated that ‘In these cases, the goals of tort law and the underlying theory of corrective justice require that the defendant not be permitted to escape liability by pointing the finger at another wrongdoer’. Here, it is suggested that a more profound level of justice is necessary in order to satisfy the aims of tort law, as opposed to the somewhat superficial outcome that would have been achieved if there were no recovery of damages merely because of the inability of science to attribute fault to a sole employer.
Similarly, the Supreme Court of California in Rutherford v Owens-Illinois Inc 2 d 16 decided that a claimant in an asbestos product liability claim was not required to prove that his exposure to the defendant’s product actually caused his cancer. RInstead it would be sufficient if he showed that his exposure was a substantial factor in increasing his risk of developing cancer. This decision could be construed as being the American equivalent to the Fairchild principle above. Furthermore, the Californian Supreme Court stated that the substantial factor test is rather broad ‘requiring only that the contribution of the individual cause be more than negligible or theoretical’.
Equally, it could be argued that the ‘materially increased risk’ test is also broader than the traditional ‘but for’ model in that it takes a more holistic approach to the recovery of damages as it focuses on more than one potentially culpable employer.In addition, the court said that this test is designed ’to aid plaintiffs as a broader rule of causality than the ‘but for’ test.’ This once again illustrates that these further modifications to the ‘but for’ test neutralise its rather harsh effects in some situations.
The ‘substantial factor’ test in Rutherford has even been applied to a single wrongdoer case by the United States Court of Appeals for the Ninth Circuit in Kennedy v Southern California Edison Co 22 Ill.219 F.3d 988 (9th Cir. 2000). In that case, the claimant argued that his wife’s cancer was caused by radiation from nuclear pods. The Court suggested that, often, it may be scientifically impossible to prove that fibres from the defendant’s product actually began the course of the cancer, rather, it would be sufficient to prove that exposure to the defendant’s product was a substantial factor contributing to the risk of developing cancer.
Moreover, one could go further to say that these cases indicate exceptions to the traditional ‘but for’ test. For instance, the Supreme Court of Canada in Cook v Lewis 1951 SCR 930 decided that a claimant who was struck by a single pellet when two hunters negligently discharged their shotguns could sue either of the two defendants for the whole of the damage. This operates as an exception to the ‘but for’ test because if the traditional model was to be applied, the claim would fail due to not being able to prove whose breach led to damage. One may argue that this would cause injustice to one of the hunters as they would be liable for an injury that they did not cause. However, the Canadian Supreme Court decided that the level of injustice to the claimant if he were to be deprived of recovering damages would outweigh the injustice to one of the defendants.
The Supreme Court of California in Sindell v Abbott Laboratories 26 Cal. 3d 588 (1980) ruled on the apportionment of damages when a claimant was injured by exposure to a drug (‘DES’) in which a number of manufacturers had produced and marketed. The claimant could not prove which manufacturer had produced the specific DES to which she had been exposed.
The Californian Supreme Court applied a ‘market share’ rule which means that the claimant could sue a number of manufacturers who might have produced the specific DES that caused her injury. Each of them would be liable according to their market share of the product. Thus, the greater the market share, the more likely it is that they made the product that caused the damage.
Once again, this is an exception to the orthodox ‘but for’ test as the claim would fail if it were to be applied. One could say that the rationale of this decision is that there is an inequality in bargaining power between manufacturers and claimants and so manufacturers are in a better position to pay the damages since they are more likely to be insured. In addition, if liability is imposed on manufacturers, it acts as a further incentive for them to guard against product defects.
Overall, it is evident that the modifications to the ‘but for’ test are rather wide in scope in that they apply to a range of substances and are not confined to multi-defendant cases.