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Previous: Breach of duty


In the tort of negligence, we know that there must be a duty of care; a breach of that duty of care and damage. Causation is a concept consisting of two elements which helps limit liability. The first element of causation is termed ‘causation in fact’: at least in part, the damage caused to the claimant must have resulted from the defendant’s breach of duty, or in other words, the defendant must have caused the damage. The second element is known as causation in law, which requires as a matter of policy that damage is not too remote in order to avoid disproportionate liability.

‘But for’ causation

So how does the law decide whether the defendant caused the damage or not? Usually, this point does not arise, the cause is usually obvious. However where it is not, the courts use the ‘but for’ test, which asks:

But for the defendant’s action, would the damage have occurred?

If the answer to this question is ‘no’, liability will be found. Another way of phrasing the question is to say ‘if the defendant didn’t act, would the damage have occurred?’

There are many examples which illustrate the application of the but for test. In McWilliams v Sir William Arrol [1962], supplying a safety harness would not have prevented the damage as the claimant would have refused to wear it. Similarly, in Barnett v Chelsea & Kensignton Hospital [1969], a negligent failure to diagnose arsenic poisoning did not give rise to liability as the defendant would have died even if diagnosis has occurred, and in Robinson v The Post Office [1974], no liability was found in negligently not waiting 30 minutes before administering a full dose of anti-tetanus drug as no reaction would have been visible 30 minutes after administering a test-dose.

An exception to this list of examples can be found in Wright v Cambridge Medical Group [2001] where liability was found against a doctor who had negligently referred a 9 month old baby 4 days later than he should have done. The hospital then caused permanent damage to the baby’s hip bone. Apparently, different doctors would have treated the baby 4 days’ earlier and the damage would not have occurred.

Issues with ‘but for’ causation

As highlighted in Wright, the ‘but for’ test often requires hypothetical evidence on how a 3rd party would have acted. Contrary to Wright, Bolitho v City & Hackney HA [1997] found no liability for the death of a 2 year old child where a doctor had failed to attend prior to respiratory arrest. The claimant could not show that the doctor would have intubated the child had attendance occurred – it would have been reasonable not to carry out such a dangerous procedure on a young child.

It is difficult to reconcile Wright with Bolitho. This highlights the first issue with ‘but for’ causation. One might suggest that Wright was based on the hypothetical behaviour of a 3rd party (the hospital), whereas Bolitho concerned the hypothetical behaviour of the defendant specifically; it may not have been reasonable for the doctor to rely on the hospital.

Having multiple causes of damage can also undermine the ‘but for’ test. It is said that the defendant need not be the only cause of damage, but must have contributed. As such, in Burrows v March Gas Co [1872],  a defendant was liable for installing a defective gas pipe despite the fact that the damage (an explosion) was caused by a contractor using an open flame when inspecting the pipe. Similarly in Hill v New River Co [1868], the defendant was liable for damage caused after a water leak caused by the defendant then caused horses to swerve into a hole negligently unmarked by a third-party. In both cases, the defendants at least contributed to the damage, satisfying the but for test. Sometimes, it is not possible to establish who actually caused the damage. This was the case in Fitzgerald v Lane [1987] where two cars hit the defendant successively. Both drivers were held liable. As a general rule, where two independent factors cause damage, liability will only be imposed to a cause which was at least twice as likely to have caused the damage. This was established in the recent case of Sienkiewicz v Grief [2011] and then confirmed in Jones v SS Energy [2012] where the claimant could not prove that his lung cancer was twice as likely to have resulted from a failing of statutory duty over other causes.

Exception to ‘but for’ causation

There are a number of exceptions in which the ‘but for’ test is not used as it would lead to an unjust outcome.

Cumulative damage

Where damage is caused cumulatively, only a material contribution to the damage is required. This was ruled in Bonnington Castings v Wardlaw [1956] where a small amount of dust may have contributed to the ‘tipping point’ of contracting a lung disease. In Bailey v MoD [2008], brain damage was caused where the claimant aspirated his own vomit. The MoD was liable for leaving Bailey in a weakened state following a gallstone operation. They had materially contributed to the damage. Asbestosis, a disease whose chance of contraction is increased cumulatively by exposure to asbestos dust may have its damages apportioned between negligent employers, according to Holtby v Brigham & Cowan [2000]. The ‘but for’ test is therefore not relevant. Finally, in the case of McGhee v National Coal Board [1973], it was enough that the claimant’s employer had materially contributed to his contraction of dermatitis in not providing on-site washing facilities.

For this exception to apply, the damage must be cumulative. In Wilsher v Essex AHA [1988], the administration of excess oxygen to a child was only 1 of 5 equally possible causes of brain damage, therefore no liability was found.


Where a case concerns the contraction of mesothelioma, according to Fairchild v Glenhaven Funeral Services [2002], damages are not apportioned (unlike for asbestos). This is because the risk of contracting mesothelioma is not increased cumulatively, and science currently gives us no way to show who (usually which employer) caused it. Barker v Corus [2006] attempted to apportion damages for mesothelioma, allowing for the possibility of a brief period of self-employment. However, the legislature quickly intervened with section 3 of the Compensation Act 2006, which provided that damages for mesothelioma may not be apportioned, allowing full damages to be attributed to any single employer. This was applied in Sienkiewicz v Grief [2011], where full mesothelioma damages were awarded where the contributory risk was found to be just 18%; the only other cause was the environment. So in cases concerning mesothelioma, a material increase in the risk is all that is required.

This exception may not be extrapolated to other circumstances. In Clough v First Choice Holidays [2006], the Fairchild (mesothelioma) exception was not applied to a self-inflicted injury where the claim concerned paint being too slippery. In AB v MoD [2010], damages for cancer were not available where there were many other potential causes, and finally, the Supreme Court in Re J (Children) [2013] ruled that the Fairchild exception may only be applied to mesothelioma cases.


As a minor point, where the ‘but for’ test cannot be applied as either defendant could have caused the damage; damages will be apportioned evenly. This is illustrated by Cooke v Lewis [1951, Canada] where either defendant could have shot the claimant and no-one was sure which one did. The ‘but for’ test would not work in such a scenario and so damages were split.

Deprivation of a chance

It would be difficult to apply the ‘but for’ test to a scenario in which the defendant simply reduced the claimant’s chance of avoiding damage ultimately not caused by that defendant. Therefore the rule laid down in Hotson v East Berkshire AHA [1987] says that recovery may be permitted if the loss of a chance is greater than 50%. In Hotson, a misdiagnosis of a hip bone injury led to a 25% reduction in the claimant’s chance of making a recovery from the injury, therefore the claim failed. In Gregg v Scott [2005], a 42% loss of a chance of recovery following a misdiagnosis of cancer was also not compensable.

Of course, the concept becomes more difficult to enforce where percentages cannot be attributed to the loss of chance. The aforementioned case of Wright v Cambridge Medical Group [2001] appeared not to concern itself with percentages and awarded damages anyway. Similarly, in Spring v Guardian Assurance [1995], damages were awarded for a negligently written reference and in Allied Maples v Simmons & Simmons [1995], damages were awarded for the loss of a chance of a negotiating opportunity following the drafting of a contract. It is difficult to say whether this is inconsistent with Gregg v Scott [2005].

Multiple causation

Where there are multiple causes of damage, the ‘but for’ test can lead to injustice, therefore different rules may apply.

Multiple sufficient concurrent causes

Where there are two causes which combine, such an in Anderson v Minneapolis [1920] where a natural fire combined with a fire created by the defendant, there may be liability through a ‘substantial factor’ test, however, usually, liability is split. As such, in Corey v Havender [1902, America], 2 motorcyclists were each liable in part for scaring horses by overtaking them quickly, and in Greenwich Millenium Village v Essex Services Group [2013], two separate installers of valves were each liable in part for the damage caused by a disastrous flood caused by the improper installation of both valves. In Harooni v Rustins [2011], there was no liability where a fire spread from the defendant’s factory to the claimant’s factory through a 3rd party’s factory, irrespective of a factual dispute.

Successive sufficient causes

Where one cause increases the damage caused by a previous cause, the courts appear to try to look for a just result. As such, in Baker v Willoughby [1969], a driver who ran over the claimant’s leg was liable for the injury caused indefinitely, despite the fact that before the trial, a criminal had shot the claimant in the same leg, requiring its amputation. The driver was liable as if the successive injury had not been sustained.

Most recently however, the case of Haxton v Phillips Electronics [2014] ruled that a reduced life expectancy should be accounted for in calculating damages, even where that reduced life expectancy is caused by the defendant. Also, in Jobling v Associated Dairies [1982], account was taken for an inevitable and unrelated future disability in calculating damages. So perhaps the approach is now much more realistic. In Dillion v Twin State Gas Co [1932], a boy already falling off a bridge grabbed hold of a cable owned by the defendant. This cable electrocuted the boy and killed him before he hit the ground below the bridge (which would have killed him in any event). No damages were awarded as the court took account of the reduced life expectancy of the boy, which was just a few seconds. This approach seems preferrable to then courts over Baker v Willoughby [1969].

Separate causes where harm is divisible

As a final point to the idea of causation in fact, in Rahman v Arearose [2001], the manager of a Burger King restaurant was assaulted, sustaining an eye injury. Later hospital treatment was performed negligently, resulting in blindness. Damages were apportioned in this complex case.

Remoteness of damage

If causation in fact can be established, liability may still be negatived by causation in law, or remoteness. Initially, in Re Polemis [1921], the test of remoteness was that of a direct consequence of the defendant’s actions. This case seems quite unfair, and we now have a new test, that of reasonable foreseeability. However it is worth pointing out that, as confirmed by the case of Simmons v British Steel [2004], intended consequences are never too remote. The reasonable foreseeability test, which overruled the Polemis test, was created in The Wagon Mound (No. 1) [1961], where it was required that the particular ‘kind’ of damage must be reasonably foreseeable for damages to be awarded. The Wagon Mound (No. 2) [1967] followed this new test and awarded damages. Of course, the test is dependant on how strictly the word ‘kind’ is construed. In The Wagnomound (No. 2), the ‘kind of damage’ was said to be that of disastrous damage to the claimant’s property.

Qualification of the reasonable foreseeability test

Confirmation of The Wagonmound

The Wagonmound test has been confirmed on many occasions. In Wells v Sainsbury and Hannigan [1962] it was reasonably foreseeable that if a pneumatic hose was pointed at a person, its activation would ‘blow that person up’, and in Holley v Sutton LBC [2000] it was reasonably foreseeable that children would play on a boat left unattended; therefore liability was found when the propped-up boat fell on a child. It was, however, unforeseeable that an asbestos explosion would be of such a great magnitude in Doubty v Turner [1964] just as it was unforeseeable in Tremain v Pike [1969] that an occupier would contract Weils disease where contact with rat urine was not foreseeable.

Method of infliction of damage

There are a two points to add to the Wagonmound test. Firstly, it should be noted, following The Arpod [1934] that it is relevant who suffers the damage: running over a millionnaire will cost more that running over someone with less wealth. Secondly, where a kind of damage is reasonably foreseeable, the method of that infliction is irrelevant. In Hughes v Lord Advocate [1963], burning on a lamp was foreseeable, therefore burning caused by an explosion initially caused by the lamp was also foreseeable. In Stewart v West African Terminals [1964], many accidents could have resulted from the presence of a wire, all of which were reasonably foreseeable.

Thin skull rule

The presence of a ‘thin skull’ does not affect causation in law. As such, if a claimant has a particular hypersensitivity which is exploited by the defendant, that defendant will be liable for the full extent of the damage caused to the claimant. In Smith v Leech, Brain & Co [1962], an employer was negligent for an injury becoming cancerous following an accident resulting from a negligent process. In Robinson v The Post Office [1974], if liability had been imposed, it would have accounted for the claimant’s hypersensitivity to the anti-tetanus drug, and in Warren v Scruttons [1962], the defendant was fully liable for the blindness of the claimant caused by a pierced finger.

Intervening causes

Between a breach of duty and damage is a ‘chain of causation’, a chain of events which leads to the damage. In some cases, there may be only 1 ‘link’, in which case it is more likely that the damage caused will not be too remote to be compensable by the defendant. However, there can often be much longer ‘chains’. Usually, the chain of causation will not be broken by a reasonable act, therefore liability will still be imposed. However, intentional misconduct will often breach the chain. In Chubb Fire Ltd v Vicar of Spalding [2010], the chain of causation was broken where vandals set off some fire extinguishers provided by Chubb. Chubb was not liable for providing extinguishers which were ‘particularly messy’ in the absence of evidence that they would not have been purchased had the church been given advice to that effect.

Reasonable supervening acts

In Scott v Shepherd [1773], the chain of causation was not broken in a number of stall-holder throwing on a firework thrown into a market by the defendant, before it exploded and injured the claimant. Similarly, in The Oropesa [1943], it was reasonable for a captain to use a smaller boat to meet with a captain of another ship who had just crashed into the former’s ship. The latter captain was held liable for the death of the first in his traversal.

Gross misconduct

If an intervening act is reckless, the chain of causation will be broken and the intervener held liable. In Rouse v Squires [1978], a third party swerved acorss a road, causing a chain of crashes. One of these crashes involved Squires killing Rouse, for which Squires was held partly liable for not keeping a look out. Similarly, in Wright v Lodge [1993], a third party negligently left their car on a motorway. Lodge was liable for injuring Wright, who was travelling on the other side of the motorway, after Lodge crashed into the third party and ended up blocking the path of Wright. Finally, in Knightley v Johns [1982], a police officer’s order broke the chain of causation in a claim where a subordinate officer was injured in riding against the flow of traffic entering a tunnel.

Intentional acts

The chain of causation is usually broken by an intentional act. Therefore, in Weld-Blundell v Stephens [1920], the making of libellous statements broke a chain of causation of damage involving negligent disclosure of documents. The chain will not be broken if liability can be found in a negligent omission, just as in Stansbie v Troman, Home Office v Dorset Yacht or Smith v Littlewoods.

Intervening act of the claimant

If a claimant breaks the chain of causation themselves, liability may either be negatived entirely or reduced with contributory negligence. This will occur where the act of the claimant is unreasonable. In Jones v Boyce [1816], it was reasonable for the claimant to jump out of a moving carriage to avoid a crash. Also, in Yachuk v Oliver Blais [1949], the chain of causation was not broken in the claimant burning themselves on petrol as the petrol should not have been sold to a 9 year old child.

Where an act of the claimant is unreasonable, the chain will be broken. In McKew v Holland [1969], the claimant had been warned about his leg giving way, therefore it was unreasonable for him to attempt to avoid catastrophe on an unrailed staircase by jumping down it. He claimed for personal injury and failed. However, in Wieland v Cyril Lord Carpets [1969], the claimant’s reasonable act did not break the chain of causation.


Liability will not be imposed where but for the defendant’s act, the claimant would not have been put in the position where they suffered damage. This point was raised in the SAAMCO case [1997] where it was said that a negligent knee examination which caused a mountain expedition to go ahead would not lead to liability where injury was sustained on the expedition as long as it was not caused by the knee. The exception to this rule can be found in Chester v Afshar [2004] where liability was imposed for not  warning of a 1% risk of paralysis. Proof of an alternative cause of action had the risk been warned of was not proved, though there were strong dissents from Lord Bingham and Lord Hoffman who said that the case fit within the coincidence rule. They also said that a warning of the risk would only have delayed the operation, and the paralysis would still have resulted. Beary v Pall Mall Investments [2005] refused to apply Chester to circumstances involving financial advice.

General points concerning liability in tort

At this point, it is important to note a few points about how liability is imposed generally in the law of tort.

Joint and several tortfeasors

Where damage is caused by more than 1 tortfeasor, if harm is divisible, divide accordingly. If one person encourages a tort, they may be classed as a tortfeasor. In Pitts v Hunt [1991], a pillion passenger who provoked the scaring of pedestrians was partially liable. However, providing a facility to commit a tort does not give rise to liability, as held in CBS Songs v Amstrad [1988]. There may be a joint duty, for example if there are multiple occupiers, or there may a joint action to a common end.

If there are multiple tortfeasors, a claimant can recover from any single defendant. That defendant is then entitled to claim against any other tortfeasors under s 1(1) of the Civil Liability (Contribution) Act 1978. Under s 2(1), a just and equitable sum may be available given the history of events and blameworthiness of the defendant.

Contributory Negligence

At common law, contributory negligence used to be a complete defence to a claim in tort. However, the Law Reform (Contributory Negligence) Act 1945, s 1(1) prevented claims from being defeated entirely and provided for a reduction in damages instead. Contributory negligence may be unavailable in situations involving children (Yachuk v Oliver Blais [1949] – petrol), incapacity (Daly v Liverpool Corp [1939] – elderly claimant tried best in crossing road), intoxication (Owens v Brimmel [1978] – passenger knew of intoxication before getting in car) and emergency (Jones v Boyce [1816] – jumping from cart, The Bywell Castle [1879] – turning down a one way street in an emergency). Contributory negligence must clearly be that for the defence to successfully reduce damages. In Jones v Livox Quarries [1952], the claimant was negligent in riding on the towbar of a quarry truck and in Froom v Butcher [1976], it was negligent for the claimant not to be wearing a seatbelt. Apportionment works the same way as for joint tortfeasors.

Volenti non-fit injuria

To a willing person, no injury is done

If the claimant consents to an injury, they cannot claim compensation for that injury. In Sidaway v Bethlem Royal Hospital [1985], it was said that a hospital need not disclose all risks to a patient and the Unfair Contract Terms Act 1977 prevents the exclusion of liability for personal injury caused by negligence.

It is often difficult to show implied consent to injury, however, according to Owens v Brimmel [1976] such consent is found of a passenger to an intoxicated driver, but in Nettleship v Weston [1971], a driving instructor did not consent to negligence on the part of a learner driver. The Road Traffic Act 1988, s 149 prevents passengers from consenting to injury in the capacity of a passenger. The volenti defence was successful in ICI v Shatwell [1965], where testing of detonators took place within the danger radius, and in Titchener v British Railways Board [1983] where a trespasser consented to being run over by a train.


Claims in tort may not be made by those participating in a criminal act at the time of the ‘breach of duty’. As such, in Ashton v Turner [1981], a driver of a getaway vehicle was not liable to the passenger for personal injury. Similarly, in Grey v Thames Trains [2009], a claim for damages against the causer of the claimant’s PTSD failed after the claimant had been convicted of manslaughter.

However, incidental criminal acts are not subject to the same restrictions. In Delaney v Pickett [2011], a claim was not barred just because the claimant had been carrying illegal drugs in his car at the time, he was not engaged in a criminal act. The claim in Clarke v Clarke [2012] was also not barred where the claimant had started a fight with the defendant. Subsequently driving over the claimant with a jeep broke the chain of causation. Finally, in Joyce v O’Brien [2012], there was no liability of a getaway car driver to an accomplice who suffered personal injury when holding a ladder in the back of the van.

Limitation Act 1980

Claims in both contract and tort law must be made within 6 years. In tort section 2, that 6 years starts from the time of the cause of action arising. Section 4 limits this time period to 1 year in any case of defamation, and section 11 and 14 limit the time period to 3 years in negligence or nuisance claims starting from the date of knowledge of the injury.

Death claims

Section 1 of the Law Reform (Miscellaneous Provissions) Act 1934 provides that causes of action survive through death, and the Fatal Accidents Act 1976 allows dependency and bereavement claims to be made.

Vicarious liability

Any employer is strictly liable for the acts of their employees. This encourages careful hiring and safe working environments. It is unusual to assume vicarious liability for a contractor. This will only occur in cases concerning non-delegable duties, such as was the case in Woodland v Essex CC [2013]. For vicarious liability to apply, the employee’s action must occur in the course of their employment. In Lister v Hesley Hall [2011], sexual assault on children by a warden was ‘closely connected’ with the warden’s employment. Liability in similar circumstances was imposed in Catholic Child Welfare Society v Various Claimants [2012]; there was a relationship akin to employment.

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