September 2016


Plaintiffs seek causal connection in toxic torts

By David McKenna, Partner, Jarman McKenna
This is an edited version of a paper presented at an AILA WA event.

Most asbestos diseases are indivisible, which means, with cumulative exposures, science does not allow medical experts to say which exposure resulted in contracting the disease.

Where a disease is indivisible, any defendant whose breach of duty materially contributes to contracting the disease will be jointly and severally liable for a plaintiff’s loss.

It is usual for defendants to attempt to determine the relative risk of each exposure to determine their relative liability and contribution.
However, a plaintiff can chose to sue only one defendant, which must then join other joint tortfeasors to obtain contribution.
Asbestosis is a divisible disease, so medical experts can determine the relative risk of an exposure to contracting asbestosis.
Lung cancer is indivisible, but a contributory negligence reduction is common if a plaintiff has been a smoker and there’s evidence that has materially contributed to the onset of lung cancer.

The UK position

The onus is on a claimant in an occupational disease claim to show, on the balance of probabilities, a causal connection between the defendant’s breach of duty and the claimant’s loss.

The traditional “but for” test means a claimant has to show his injury would not have occurred but for the defendant’s breach of duty.
Applying the test to a situation where two or more people caused the plaintiff to be cumulatively exposed to harmful dust resulting in the onset of disease means the plaintiff must prove each exposure was causative by showing, but for that exposure, the disease would not have been contracted.
The science on contracting mesothelioma remains uncertain.

The House of Lords, in Bonnington Castings v Wardlow [1956] AC 613, developed the material contribution principle to overcome that difficulty for plaintiffs.

The claimant worked in a foundry and developed pneumoconiosis from inhaling silica dust. He was exposed concurrently to dust from swing grinders, which the defendant should have prevented, and dust from pneumatic hammers, which was an “innocent” exposure.

The claimant could not show which exposure caused his pneumoconiosis.

The Lords said dust from the swing grinders materially contributed to the disease, so the defendant was liable for the full extent of the loss, notwithstanding the “innocent” exposure was greater.

The principle was further developed in McGhee v the National Coal Board [1972] 3 All ER 1008. The House of Lords allowed a claim where the defendant’s negligence had materially contributed to the risk of the claimant contracting dermatitis following exposure to brick dust. The claimant was innocently exposed but the employer failed to provide washing facilities so the claimant was left with the dust on his skin.

The Lords revisited McGhee in Fairchild v Glenhaven Funeral Services [2002] UKHL 22.

They heard appeals from three separate cases with similar facts. The claimants all contracted mesothelioma from asbestos dust exposure at work. Each had been wrongly exposed by more than one employer over several years but, because of gaps in scientific knowledge, was unable to show which period of exposure had caused them to contract the disease.

Despite that, the claimants were awarded damages. The Lords decided if some pre‑conditions were met, proof that negligent conduct increased the risk of an injury was sufficient to establish the causal requirement for liability.

The Fairchild exception applies where multiple defendants are in breach of a similar duty. The Lords decided it would be unfair or unjust to deprive a claimant of compensation simply because they cannot prove the impossible, but set strict limits to applying the exception.

In Barker v Corus (UK) Plc [2006] UKHL 20, the Lords decided that, for successive negligent exposures, liability should be apportioned between defendants.

Each employer would be liable for the proportion of damage that represented his contribution to the risk the employee would contract mesothelioma. The Lords said proportional allocation was not just between different employers but also for periods of non-tortious exposure. A victim would thus have separate actions for different measures of damages against successive tortfeasors, but no claim for periods of non-tortious exposure.
That was a clear departure from the Fairchild exception but the UK Parliament intervened to pass s3 of the Compensation Act 2006 to reverse Barker v Corus and preserve Fairchild.

The UK Supreme Court again considered the issues in Karen Sienkiewicz (Administratrix of the Estate of Enid Costello deceased) v Greif (UK).

Enid Costello died of mesothelioma in January 2006. From 1966 until 1984 she was an office worker at the defendant’s factory where asbestos dust was released into the atmosphere. Although Costello did not work on the factory floor, her duties took her all over the premises, so she would also have been exposed to a low level of asbestos.

The trial judge applied a “doubles the risk” causation test. Only if the occupational exposure could be shown to have at least doubled Costello’s risk of contracting mesothelioma could the defendant be held liable. The Court of Appeal found the proper test was whether the occupational exposure had materially increased the risk of contracting the disease.

However, it said Fairchild had effectively created a new tort, limited to mesothelioma cases, of negligently materially increasing the risk of injury. It said s3 of the Compensation Act made it law that, provided four conditions were satisfied, causation could be proved by demonstrating a defendant wrongly “materially increased the risk” of the victim contacting mesothelioma.

The Supreme Court unanimously dismissed an appeal. It said the Fairchild exception was developed because of ignorance about mesothelioma’s biological cause. Under it, a defendant was liable if it materially increases the risk of a claimant contracting mesothelioma. The same principle applied for single or multiple exposures.

However, it said the Court of Appeal had misread the Compensation Act as creating a statutory rule of causation. S3 merely provided that, if a defendant negligently exposed a claimant to asbestos and the claimant contracted mesothelioma, the defendant would be liable in tort “whether by reason of having materially increased a risk or any other reason”.

Whether and when liability attached to the defendant was still a matter for the common law. The “doubles the risk” test was unsuitable as a causation test in mesothelioma cases and what constituted a material increase in risk was a question for the judge on the facts.

So, in the UK, the appropriate causation test is set out in the Fairchild exception.

The Australian position

Australia’s causation test is not the same. In Amaca Pty Ltd v Booth, Amaba Pty Ltd v Booth [2011] HCA 53, the High Court said Australian courts had not adopted the Fairchild principle.

Australia’s causation test is generally the "but for" test – whether, but for the defendant's breach, the plaintiff would have contracted the disease. However, for an indivisible disease, the High Court has accepted the causation test may be satisfied by establishing the defendant's breach has made a material contribution to contracting the disease.

A defendant, or its insurer or insurers, required to bear 100% of the loss is entitled to contribution from any other insurer on risk for a defendant jointly liable during the plaintiff's exposure period, where a breach at that time has materially contributed to the plaintiff suffering the disease.

The Zabic decision

The Zabic decision arose out of Northern Territory legislation that abolished any common law cause of action unless it had accrued before 1 January 1987. Zabic was employed by Alcan Gove from 1974 to 1977. He did not experience mesothelioma symptoms until 2013 or 2014. If the cause of action had accrued before 1 January 1987, he had a right to pursue a damages claim at common law. If not, it was statute barred.

The judge at first instance held the cause of action did not accrue until the onset of the malignant mesothelioma and the action was statute barred.
The Court of Appeal reversed that decision, finding it was possible Zabic’s mesothelial cells were damaged shortly after inhaling asbestos fibres between 1974 and 1977, which "inevitably and inexorably" led to the onset of mesothelioma.

Alcan Gove was granted leave to appeal to the High Court and the appeal was dismissed.

The High Court said it was probable Zabic did not develop a malignant mesothelial tumour until shortly before first experiencing symptoms in 2013 or 2014. But, based on expert evidence, it could be inferred the asbestos fibres inhaled from 1974 to 1977 had then or shortly afterwards (therefore before 1 January 1987) resulted in initial molecular changes that culminated in the tumour.

The court said actual damage or injury was an essential element of a cause of action in negligence for personal injury. What may qualify as actionable damage is a question of fact and degree and, ultimately, of policy.

The court considered whether the mere risk of contracting mesothelioma was sufficient to amount to compensable damage. In Orica Ltd v CGU Insurance Ltd (2003) 59 NSWLR 14, the NSW Court of Appeal found the kind of injury suffered by just inhaling asbestos fibres was not compensable damage and therefore a cause of action did not accrue unless and until mesothelioma developed.

In Orica, the court was considering whether an insurer on risk from 1959 to 1961 when the worker was exposed was liable to indemnify for the worker's mesothelioma that developed years later. Mason P, while acknowledging a negligent employer fell under a potential liability to compensate the worker, his estate and dependants according to tort law, said the liability remained inchoate, in the eyes of tort law, because damage was the gist of the relevant cause or causes of action.


When considering an on-risk insurer’s liability while the plaintiff was exposed to fibres, it is necessary to critically examine the precise policy wordings that give rise to a right to indemnity. Does the policy refer to:

"An injury during the policy period, a personal injury happening during the period of insurance, the employer being liable to pay compensation under the Act to and in respect of any person who is or is deemed by the Act to be a worker of such employer."

Based on the Zabic decision, it is likely in a mesothelioma case it will found that any non‑negligible exposure the plaintiff experiences at any time before the onset of symptoms will constitute damage and an injury.

It is therefore likely to satisfy the requirements of an employer's indemnity policy, being an injury during the policy period; and to satisfy a public and products liability policy being a personal injury happening during the period of insurance and a liability accrued and/or shortly after the time of the exposure.

It is now clear from Zabic, a plaintiff does not have to manifest symptoms to constitute damage or injury, or have a fully accrued cause of action.

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