Negligence: Duty, Breach & Causation

Introduction

Negligence is a core area of tort law. It deals with situations where someone fails to take reasonable care and another person suffers loss or injury as a result. To succeed in a negligence claim, a claimant must prove three elements: that the defendant owed a duty of care, that the duty was breached, and that the breach caused the loss in fact and in law.

This guide sets out the tests used by the courts, the leading cases, and practical steps for applying the law in problem questions and real disputes. You will find clear explanations of duty, breach, factual and legal causation, with short case summaries and a quick reference table at the end.

What You'll Learn

• How courts decide if a duty of care exists, including Caparo and Robinson
• How the standard of care is set for ordinary people and professionals
• How breach is assessed using risk, seriousness, practicability and utility
• How causation works: but-for, material contribution, and risk-based exceptions
• How remoteness and intervening acts can limit liability
• How contributory negligence and other defences affect outcomes
• How to structure answers and advise clients in negligence cases

Core Concepts

Duty of Care

Modern duty of care analysis began with Donoghue v Stevenson [1932] AC 562, which introduced the neighbour principle: you must take reasonable care to avoid acts or omissions likely to injure people closely and directly affected by your conduct.

In novel duty situations, the leading approach comes from Caparo Industries plc v Dickman [1990] 2 AC 605:

• Foreseeability of harm
• Proximity between claimant and defendant
• Whether it is fair, just and reasonable to impose a duty

Robinson v Chief Constable of West Yorkshire Police [2018] UKSC 4 confirmed that courts should proceed incrementally by analogy with established categories, and that public authorities are generally subject to the same principles as private individuals for operational acts. There is no broad immunity, but policy decisions may still attract caution.

Common duty situations include:

• Road users to other road users and pedestrians (Nettleship v Weston [1971] 2 QB 691)
• Employers to employees to take reasonable care for safety at work (Paris v Stepney Borough Council [1951] AC 367)
• Medical professionals to patients (Bolam v Friern Hospital Management Committee [1957] 1 WLR 582)
• Occupiers to lawful visitors under the Occupiers’ Liability Act 1957

Economic loss raises special issues. Caparo shows courts are slow to recognise a duty for pure economic loss in negligence unless specific conditions are met (for example, negligent misstatements in a special relationship).

Standard of Care and Breach

Once a duty is established, the question is whether the defendant fell below the standard of the reasonable person in those circumstances. The test is objective. Learners are held to the standard of a competent person, not a novice (Nettleship v Weston).

Courts weigh several factors when judging breach:

• Likelihood of harm: the higher the chance of harm, the greater the precautions expected (Bolton v Stone [1951] AC 850)
• Seriousness of potential harm: more is required where consequences could be severe (Paris v Stepney Borough Council)
• Practicality and cost of precautions: what reasonable steps could have been taken without undue burden (Latimer v AEC Ltd [1953] AC 643)
• Utility of the defendant’s conduct: some risk may be acceptable in emergencies or socially valuable activities (Watt v Hertfordshire CC [1954] 1 WLR 835)

For professionals, the Bolam test applies: conduct is not negligent if it accords with a responsible body of professional opinion. However, that opinion must be defensible; the court can reject a practice that lacks logical basis (Bolitho v City and Hackney HA [1998] AC 232).

Causation: Factual Tests

A claimant must prove that the breach caused the loss on the balance of probabilities.

• But-for test: Would the harm have occurred but for the breach? If yes, there is no factual causation (Barnett v Chelsea & Kensington Hospital [1969] 1 QB 428).
• Material contribution to harm: Where harm is divisible or arises from cumulative exposure, a defendant may be liable if their breach made a more than minimal contribution to the harm (Bonnington Castings Ltd v Wardlaw [1956] AC 613). The principle has been applied in some medical cases where combined causes created the injury.
• Material increase in risk: In limited categories (notably single-agent mesothelioma exposure), it can be enough to show a material increase in risk rather than strict causation (Fairchild v Glenhaven Funeral Services [2003] 1 AC 32). Courts treat this as an exception. They are wary of extending it (Heneghan v Manchester Dry Docks [2016] EWCA Civ 86). Loss of a chance in clinical negligence generally fails if the chance was below 50% to begin with (Gregg v Scott [2005] 2 AC 176).

Apportionment may occur where multiple parties contribute to the damage. The Civil Liability (Contribution) Act 1978 allows the court to apportion responsibility between defendants according to their share of blame.

Legal Causation: Remoteness and Intervening Acts

Even if factual causation is established, legal limits can cut off liability.

• Remoteness: The type or kind of damage must be reasonably foreseeable (Overseas Tankship (UK) Ltd v Morts Dock (The Wagon Mound No 1) [1961] AC 388). You take your victim as you find them, so you are liable for the full extent of harm even if it is greater due to a pre-existing condition (thin skull rule: Smith v Leech Brain [1962] 2 QB 405).
• Novus actus interveniens: A new intervening act can break the chain of causation. A deliberate, informed act by a third party can break the chain; reasonable rescue attempts usually do not (Haynes v Harwood [1935] 1 KB 146; The Oropesa [1943] P 32). Where the intervening act was not truly voluntary, the chain may remain intact (Corr v IBC Vehicles [2008] 2 AC 1009). A claimant’s own voluntary act may break the chain unless the defendant had a duty to guard against that very risk (Reeves v Commissioner of Police of the Metropolis [2000] 1 AC 360).

Contributory negligence under the Law Reform (Contributory Negligence) Act 1945 reduces damages to reflect the claimant’s share of responsibility. For example, not wearing a seatbelt can lead to a reduction (Froom v Butcher [1976] QB 286).

Key Examples or Case Studies

• Donoghue v Stevenson [1932] AC 562
  Context: Manufacturer’s duty to consumers.
  Takeaway: Laid the neighbour principle; a duty is owed to those closely and directly affected by your acts.

• Caparo Industries plc v Dickman [1990] 2 AC 605
  Context: Duty for pure economic loss in company audits.
  Takeaway: Three-stage duty test of foreseeability, proximity, and whether it is fair, just and reasonable.

• Nettleship v Weston [1971] 2 QB 691
  Context: Learner driver injures instructor.
  Takeaway: Learners are judged by the standard of a competent driver.

• Bolam v Friern Hospital Management Committee [1957] 1 WLR 582; Bolitho v City and Hackney HA [1998] AC 232
  Context: Medical treatment choices.
  Takeaway: Professional practice must be supported by a responsible body and be logically defensible.

• Bonnington Castings Ltd v Wardlaw [1956] AC 613
  Context: Dust exposure causing pneumoconiosis.
  Takeaway: A material contribution to harm is enough for factual causation in cumulative causes cases.

• Fairchild v Glenhaven Funeral Services [2003] 1 AC 32; contrasted with Gregg v Scott [2005] 2 AC 176
  Context: Asbestos exposure; clinical negligence and loss of a chance.
  Takeaway: Material increase in risk is a narrow exception; loss of a chance under 50% generally fails in clinical negligence.

• Corr v IBC Vehicles [2008] 2 AC 1009; Reeves v Commissioner of Police [2000] 1 AC 360
  Context: Suicide following injury; detainee suicide.
  Takeaway: Not every act breaks causation; outcomes depend on whether the act was voluntary and the scope of the defendant’s duty.

• Rabone v Pennine Care NHS Trust [2012] UKSC 2
  Context: Psychiatric patient at real and immediate risk of suicide.
  Takeaway: Failure to take reasonable steps can breach the state’s operational duty under Article 2 (right to life).

Practical Applications

• Structure your analysis

  • Duty: Is there an established duty or a close analogy? Apply Caparo where the situation is novel, bearing in mind Robinson’s incremental approach.
  • Breach: Identify the specific precautions that should have been taken using the risk, seriousness, practicality, and utility factors. For professionals, test the position under Bolam and Bolitho.
  • Factual causation: Start with the but-for test. If cumulative causes are present, consider material contribution. For single-agent diseases like mesothelioma, assess the Fairchild exception carefully.
  • Legal causation: Check remoteness (type of damage foreseeable) and any intervening acts.
  • Defences: Consider contributory negligence (seatbelts, safety gear) and volenti where appropriate. Bear in mind apportionment between defendants.

• Evidence checklist

  • Duty and proximity: contracts, policies, statutory duties, clinical records.
  • Breach: risk assessments, maintenance logs, training records, expert opinions for professional negligence.
  • Causation: medical causation reports, timelines, alternative causes, exposure history.
  • Quantum: medical reports, loss of earnings, care needs, mitigation steps.

• Public authority claims

  • Identify whether the complaint concerns operational acts (ordinary negligence principles apply) or policy decisions.
  • Review relevant statutes and guidance; check for statutory immunities or procedural prerequisites.

• Workplace and occupier scenarios

  • Check for obvious and persistent hazards, adequacy of warnings, and whether simple precautions were reasonably available.
  • For employers, review equipment maintenance, supervision, training, and known vulnerabilities of staff.

• Clinical negligence

  • Define the alleged breaches precisely (diagnosis, advice, treatment, follow-up).
  • Obtain clear expert evidence on both breach (Bolam/Bolitho) and causation (but-for, material contribution where appropriate).
  • Be cautious with loss of a chance arguments after Gregg v Scott.

• Settlement and apportionment

  • Use the Civil Liability (Contribution) Act 1978 for contributions between multiple wrongdoers.
  • Apply reductions for contributory negligence under the 1945 Act, guided by cases such as Froom v Butcher.

Summary Checklist

• Identify an established duty or justify a new one using Caparo and Robinson
• Apply the reasonable person standard; for professionals, use Bolam with the Bolitho safeguard
• Assess breach using likelihood, seriousness, practicality, and utility factors
• Prove factual causation via but-for or, where applicable, material contribution or the narrow Fairchild exception
• Confirm legal causation: foreseeability of the type of damage and no chain-breaking act
• Consider defences and apportionment, including contributory negligence
• Use precise, well-supported expert evidence in professional and clinical claims

Quick Reference