The Phurnacite Litigation – Which Causation Test Prevails?

On 23rd October 2012, Mrs Justice Swift handed down her eagerly awaited High Court judgment in the important Phurnacite litigation cases.

183 claims were brought by various former workers at Phurnacite’s Abercwmboi plant in South Wales against the Department for Energy & Climate Change and its connected predecessors. The case involved claims for different conditions including lung cancer, bladder cancer, skin cancer, Chronic Obstructive Pulmonary Disease and chronic bronchitis.

Eight lead claims were selected for Trial which was heard in Cardiff and the High Court in London.

High Court of Justice


The judge had access to a considerable amount of evidence covering a period of approximately 50 years which referred to the working conditions at the Phurnacite plant and which also covered the chemical properties of the dust and fumes the workers alleged they inhaled during the course of their employment. Further evidence was submitted on the concentrations of various harmful substances and the effect they could have on workers.

Unsurprisingly, Justice Swift’s judgment is a lengthy one, spanning 330 pages in total and covers important points on the causation of various cancers which can be associated with exposure to certain harmful industrial substances. The current state of law in respect of proving a cancer to be connected to work is unclear and it was hoped, by legal practitioners, that the judgment would clarify the situation.

It has been confirmed by well respected commentators that whilst the uncertainties have not been completely resolved, the judgment does provide an indication of how courts may deal with what is often a complex issue, that being, the causation of occupational cancers, including asbestos related lung cancer.

Justice Swift found that large quantities of dust were constantly present in the working atmosphere of the briquetting buildings where the Phurnacite products were formed and pressed. Other workers experienced high levels of exposure to dangerous fumes and overall the working conditions were unpleasant. In reaching such findings, the judge concluded that the Defendant was negligent and in breach of statutory duty in law. This established the first part of the liability test in the test cases. A vast commentary is provided within the judgment on the second part of the liability test, namely, whether the negligent exposure actually caused the conditions claimed for. or causation as it is referred to in law.

Quite rightly, Justice Swift highlighted that the issue of causation of a cancer can be difficult to decide upon since respiratory disease and cancers can occur in sufferers without any exposure to dangerous occupational dusts and fumes. Therefore, the issue of causation in the cases was considered carefully with the aid of epidemiological and other medical evidence.

Epidemiology is the study of patterns, causes and effects of health and diseases upon people in defined populations. Such statistical evidence can be a valuable aid to a judge when assessing whether a sufferer’s condition can be connected to occupational exposure to asbestos and other dangerous substances rather than being due to any other cause such as smoking or environmental exposure to diesel fumes, for example. However, such studies are few and far between when concentrating on certain substances and the effect they have on people.

The judge concluded that the Claimants in Phurnacite, which included those pursuing claims for lung cancer, did succeed in establishing a causal link between exposure to dust and fumes at the Phurnacite plant. However, the other Claimants who were diagnosed with skin and bladder cancer failed to establish this, on the balance of probabilities, on the evidence available.

Justice Swift’s comments leading up to her conclusion are of particular interest to specialist asbestos disease solicitors. Strong arguments from both parties were raised on which type of causation test the judge should apply when assessing causation in cases of this type which would include asbestos related lung cancer claims.

The Claimants’ legal team argued that the judge should adopt the “material contribution to the development of the disease” test as outlined in the case of Bonnington Castings v Wardlaw. With assistance from the eminent, respiratory medico-legal expert and Consultant Dr Rudd, it was argued that providing the Claimant could show that they were exposed to dust that was more than negligible, they should succeed in establishing causation.

In his evidence, Dr Rudd stated that in the light of advancements in knowledge of how cancers develop following the mutation of cells, it was reasonable to conclude that an occupational exposure had materially contributed to the cancer. He relied on the fact that a common carcinogen (BaP) was present in Phurnacite exposure and smoking was multiplicative of risk or nearly multiplicative rather than additive.

Helpfully, the expert provided a lucid account of how the carcinogenic process is now better understood, underlining that carcinogens operated physically at various stages in the process to actually bring about the cancer i.e. resulting in what the Claimants’ legal team argued amounted to a material contribution to the development of the disease itself.

In stark contrast, the Defendant argued through their own expert, Professor Jones, that the judge should adopt the “doubling of the risk” test when considering causation. This test was relied upon to establish causation in the case of Shortell v Bical Construction which involved asbestos related lung cancer.

A classic example which can be used to show the working of “doubling of the risk” test is to consider a smoker’s risk of developing lung cancer in circumstances where they have also suffered asbestos exposure. If they have a 10% chance of developing the condition due to smoking and the asbestos exposure increased this risk to 30%, then 10% of the smoking population would have developed the condition in any event. As the person’s risk had been increased by an additional 20% as a result of both hazards combined then, statistically, this shows that the Claimant’s risk had doubled and, therefore, causation would be established.

This can be compared to a smoker who has a 10% risk of developing lung cancer and which risk has been increased by an additional 5% due to other hazards. This would show that the sufferer was more likely to develop the condition as a result of smoking alone and therefore, the criteria cannot be satisfied in such circumstances.

On the expert evidence submitted in Phurnacite, some of which could be described as old and out of date, the judge was unable to conclude that the negligent exposure to the dangerous dust and fumes actually contributed to the lung cancer and added that the court could only draw conclusions based on the impact on risks of developing the disease.

Justice Swift reached this conclusion despite criticism of the “doubling of risk” test being apparent in the Supreme Court decision in Sienkiewicz which was a mesothelioma claim. The judge noted that there was nothing within this judgment which precluded her from adopting her preferred approach to causation.

In Phurnacite, one Claimant, Mr Carhart, easily exceeded the doubling of the risk test, Mr Davies only just established this and in the third lung cancer case, Mr Griffiths fell short of the relevant threshold applied by the judge in dealing with causation. Of the 8 lead claims, 4 succeeded, with 4 failing, and the successful Claimants received awards of damages ranging from £4,500 to £120,000.

The question is therefore, what implications does the decision have on those looking to establish that their lung cancer is asbestos related rather than being due to any other cause?

Defendants will no doubt argue that a greater burden has now been imposed upon asbestos disease Claimants in that the “doubling of risk” test should be applied in cases involving lung cancer. This would be harder for Claimants to prove and can often involve the need to obtain complex, medical and epidemiological evidence.

However, it is open to asbestos related lung cancer sufferers to argue that the High Court decision is merely persuasive and not binding on all courts. Whilst the arguments raised by the Claimants on material contribution to the development of the condition itself may have been eroded slightly following Phurnacite, it remains open to a judge to adopt this precise approach when presented with different evidence in particular circumstances.

Dr Rudd made firm arguments in the Phurnacite litigation which could be re-iterated in future cases involving different facts and evidence. Such arguments could be given further weight in view of the unsatisfactory position in relation to the limited research available to judges when considering most carcinogens and assessing whether exposure to them has doubled the risk of a Claimant suffering with the condition.

In addition, one of the agreed points in Phurnacite could be illuminated in future asbestos lung cancer cases by Claimants. Both medical experts agreed that the effects of smoking and Phurnacite exposure combined are, multiplicative of risk or nearly multiplicative. It is therefore open to a Claimant, who has say a 5% risk of developing lung cancer due to smoking with say a 5% risk due to asbestos, to argue that they actually have a 25% risk of developing the condition due to both hazards combined (i.e. 5% multiplied by 5%).

This could result in judges being persuaded to conclude that the asbestos exposure must have played a part in the development of the condition. Future material contribution arguments are bound to be raised by Claimants in asbestos disease cases in the future.  Our team of specialist asbestos disease lawyers will continue to keep abreast of any developments.