Causation - 2

Introduction to Causation in Negligence

• Causation is a fundamental element in establishing negligence – it connects the defendant’s breach of duty to the claimant’s resultant loss.

• Two key components:

1. Factual causation (Cause-in-fact): Did the defendant’s breach actually cause the harm?

2. Legal causation (Scope of liability): Is the defendant liable for all harm resulting from the breach, considering policy, remoteness, and intervening acts?

1. Factual Causation

The ‘But For’ Test

• The primary test for factual causation:

• Application:

• To succeed, claimant must show that in the absence of defendant’s breach, the harm would not have been caused.

Challenges in Applying the ‘But For’ Test

• Multiple causes: When more than one factor could have caused the harm, the ‘but for’ test may fail.

• Indeterminate causation: When it is impossible to prove which cause led to the injury, the test cannot be satisfied.

Case Examples:

• Wilsher v Essex: Multiple potential causes (e.g., a premature baby with multiple risk factors); breach could not be established as the sole cause.

• McGhee v National Coal Board: An employer’s breach contributed to an increased risk but the specific cause of injury was uncertain—yet causation was established through the “material contribution” approach.

2. Legal Causation (Scope of Liability)

Concepts:

• Even if factual causation is established, liability hinges on whether the defendant’s breach is legally causative.

• Consider remoteness and intervening acts.

Remoteness of Damage

• Not all damages caused by breach are compensable; some are too remote.

• Principle: For liability to be imposed, the damage must be a foreseeable result of the breach.

• Case Examples:

• Hughes v Lord Advocate: The manner of infliction need not be foreseen, but the type of damage must be.

• Jolley v Sutton LBC: Emotional harm was foreseeable from a property falling.

Intervening Acts (Novus Actus Interveniens)

• External acts that break the chain of causation and shield the defendant from liability.

• Types of intervening acts:

• Negligent acts of third parties

• Natural events

• Criminal acts

• Example: If a third party's negligence causes additional harm after the initial breach, the chain of causation might be broken.

3. Causation in Complex Cases: The Material Contribution Test

Rationale:

• In many cases, especially involving industrial diseases or multiple exposures, the strict ‘but for’ causation cannot be established because there are multiple potential causes.

• Solution: Use the ‘material contribution to harm’ test, which relaxes causation requirements.

Principle:

Application:

• The breach is deemed a cause if it made a significant or substantial contribution to the harm.

• Often used in occupational health cases, e.g., asbestos exposure leading to mesothelioma.

Relevant Cases:

• Bonnington Castings Ltd v Wardlaw:

• Facts: D’s breach exposed the claimant to guilt-laden dust but also innocent dust.

• Outcome: Breach materially contributed to the injury since the guilty dust caused harm.

• Williams v Bermuda Hospital Board:

• Facts: Breach contributed to the physical weakness leading to the outcome.

• Outcome: Breach satisfied the material contribution test.

4. The Material Contribution to Harm Test

When is it used?

• When ‘but for’ causation cannot be proven due to multiple causes.

• Particularly relevant in industrial disease cases, where exposures are cumulative or multiple breaches occur.

Key Elements:

• The claimant must demonstrate on the balance of probabilities:

• That the defendant’s breach caused a ‘thing’ (e.g., exposure to asbestos fibers) which substantially contributed to the injury.

Case Law Highlights:

• Bonnington v Wardlaw: The contribution of dust from breach was material.

• Williams v Bermuda Hospital Board: The breach’s role in causing physical weakness was sufficient for causation.

5. ‘But For’ Test Cannot be Satisfied? Alternative Approaches

a) Material Increase in Risk of Harm

• Developed for cases where multiple exposures materially increased the risk but no single cause can be isolated.

• Principle: If breach materially increased the risk that the claimant would develop the injury, liability can be established.

• Application: Usually applied in asbestos-related diseases.

b) The Fairchild Doctrine

• Established in Fairchild v Glenhaven Funeral Services.

• Scenario: Multiple employers exposed the claimant to asbestos fibers over time.

• Outcome: Any breach materially increased the risk of developing disease, and each employer could be liable jointly and severally.

Key Features of the Fairchild Doctrine:

• Addresses: When the injury is caused by exposure to harmful agents over time.

• Legal basis: The breach increases the risk rather than directly causing the harm.

• Result: Claimants can sue any or all breaches that materially increased the risk, even if causation in strict sense cannot be proven.

6. The ‘Material Increase in Risk of Harm’ Test in Practice

Application in Industrial Disease Cases:

• Used extensively where:

• Multiple breaches occurred.

• Scientific knowledge cannot say precisely which breach caused the harm.

• Example case: Fairchild, where the court held that all employers who materially increased the risk of the disease could be liable.

Implications:

• Broadens liability.

• Does not require strict proof that breach directly caused the injury.

• Focuses on causal significance of breach in increasing risk.

Case Summary:

• Presumes that exposure materially increased likelihood of disease.

• Apply where scientific uncertainty prevents direct causation proof.

7. Summary Table of Causation Tests

8. Summary & Key Takeaways

• Causation in negligence is nuanced: involves both factual and legal considerations.

• Primary approach: The ‘but for’ test—clear and straightforward but limited in complex cases.

• When ‘but for’ fails: courts resort to material contribution or risk-increasing tests.

• Industrial disease cases: often depend on material contribution or risk increase due to the difficulty of proving direct causation.

• Case law evolution: reflects the courts’ recognition of the complexities of causation in health and safety contexts.

References for Further Study:

1. Wilsher v Essex Area Health Authority [1988] AC 1074

Facts:

• Claimant: Martin Wilsher, a premature baby, developed retrolental fibroplasia (RLF)—a condition causing blindness—after treatment in the defendant’s hospital.

• Negligence: Hospital staff administered excessive oxygen, a known risk factor for RLF.

• Other Possible Causes: RLF could also result from five non-negligent factors (e.g., prematurity, hypercarbia, intraventricular haemorrhage).

Legal Issue:

Could the claimant prove that the hospital’s negligence (excess oxygen) caused the RLF, given multiple potential causes?

Judgment (House of Lords):

• Rejected the "material increase in risk" argument (from McGhee v NCB).

• Applied strict "but for" causation: The claimant had to prove that, on the balance of probabilities, the excess oxygen likely caused the injury.

• Burden of proof remained on the claimant: The court could not infer causation merely because negligence was one possible factor.

Reasoning:

• Lord Bridge emphasized that mere possibility was insufficient—the claimant needed positive evidence linking negligence to harm.

• Distinguished from McGhee (where only one possible cause was negligent).

Significance:

• Strict approach to causation in medical negligence cases.

• Contrasted with later relaxed causation rules (Fairchild, Bailey).

• Shows the limits of "material contribution" where multiple independent causes exist.

2. Bonnington Castings Ltd v Wardlaw [1956] AC 613

Facts:

• Claimant: Steel dresser exposed to silica dust in a foundry, leading to pneumoconiosis.

• Two dust sources:

  1. Pneumatic hammer (non-negligent) – Dust levels within legal limits.

  2. Swing grinder (negligent) – Faulty extraction system increased exposure.

Legal Issue:

Was the employer liable if only part of the harmful exposure was their fault?

Judgment (House of Lords):

• "Material contribution" test established: The employer was liable because their breach significantly contributed to the disease.

• No need for "sole cause": Even if the swing grinder’s dust was not the only cause, it was a measurable factor.

Reasoning:

• Lord Reid: The claimant only needed to show that the negligent exposure was a material (not trivial) factor.

• No apportionment—full liability applied.

Significance:

• Foundation for "material contribution to harm" in tort law.

• Later applied in Bailey and Williams for cases where negligence exacerbates harm.

• Contrasts with Wilsher (where multiple independent causes defeated liability).

3. Williams v Bermuda Hospitals Board [2016] UKPC 4

Facts:

• Claimant: Suffered a ruptured appendix after a 9-hour delay in surgery due to hospital negligence.

• Injury worsened: Developed septic shock, requiring intensive care.

• Defence argued: The harm was primarily due to pre-existing appendicitis, not the delay.

Legal Issue:

Did the delay materially contribute to the harm, even if the claimant was already ill?

Judgment (Privy Council):

• Applied Bonnington: The delay materially worsened the claimant’s condition.

• "But for" not required: Focused on whether negligence made the harm worse.

Reasoning:

• The delay increased the severity of the sepsis, so causation was established.

• Reaffirmed Bailey: Negligence need not be the sole cause, just a significant contributor.

Significance:

• Confirmed that aggravation of pre-existing conditions can establish liability.

• Reinforced Bailey’s approach in medical negligence cases.

4. Fairchild v Glenhaven [2002] UKHL 22

Facts:

• Workers developed mesothelioma after asbestos exposure by multiple employers.

• Scientific uncertainty: Impossible to determine which exposure(s) triggered the cancer.

Legal Issue:

Could claimants sue when the exact causative exposure was unknown?

Judgment (House of Lords):

• "Risk-based" exception: Defendants liable if their negligence materially increased the risk of harm.

• Joint and several liability: Each employer held fully liable(later modified by Barker v Corus).

Reasoning:

• Lord Bingham: Policy justification—workers should not be denied compensation due to scientific uncertainty.

• Strict "but for" test relaxed due to exceptional circumstances.

Significance:

• Created a special rule for mesothelioma cases.

• Later limited by Barker (proportional liability) but restored by Compensation Act 2006.

5. Bailey v Ministry of Defence [2008] EWCA Civ 883

Facts:

• Claimant: Developed brain damage after vomiting led to cardiac arrest in hospital.

• Negligence: Failure to monitor post-surgery.

• Pre-existing condition: Pancreatitis weakened her.

Legal Issue:

Could negligence be a cause if the claimant was already vulnerable?

Judgment:

• "Material contribution" applied: Negligence weakened her, leading to the crisis.

• Not a Fairchild-style exception: Traditional causation sufficed.

Reasoning:

• The combined effect of negligence + pre-existing condition caused harm.

• Distinguished from Wilsher: Here, negligence actively contributed to the injury.

Significance:

• Bridged Bonnington (industrial harm) and medical negligence.

• Allowed claims where negligence exacerbated pre-existing risks.

Comparative Analysis Table