Fairchild v Glenhaven Funeral Services  1 AC 32 is a landmark case in English tort law that dealt with the issue of causation in cases of mesothelioma, a type of cancer caused by exposure to asbestos. It affirmed the alternative test of "materially increasing risk" of harm, as a deviation in some circumstances from the ordinary "but for" test.
Mr. Fairchild was a former employee of a number of companies that had exposed him to asbestos over a period of many years. He contracted mesothelioma as a result of this exposure and brought a claim for damages against his former employers. The defendants argued that they could not be held liable for Mr. Fairchild's illness because there was no way to prove which particular exposure had caused the disease.
The House of Lords rejected this argument and held that the defendants could be held liable for Mr. Fairchild's illness even though they could not prove which particular exposure had caused it. The court reasoned that in cases where there are multiple possible causes of an injury or illness, and each of these causes was a necessary condition for the injury or illness to occur, each of the potential defendants who exposed the victim to the risk of injury or illness should be held liable. This approach is known as the "material contribution test."
The decision in Fairchild has been controversial, with some arguing that it departs from traditional principles of causation in tort law. However, it has been influential in subsequent cases involving mesothelioma and other diseases caused by exposure to toxic substances.