## Introduction

Breach of duty of care sits at the core of negligence in tort. It arises where a person or organisation owes a legal duty to another and fails to meet the standard expected in the circumstances, causing loss or damage. To succeed in negligence, a claimant must show four elements: duty, breach, causation, and that the damage is not too remote.

This guide sets out the governing tests, explains how the courts assess standards of care across common contexts (road traffic, healthcare, employment, public authorities), and summarises leading cases you should know for exams and practice.

## What You’ll Learn

- How a duty of care is established, including the Donoghue and Caparo tests
- The objective “reasonable person” standard and when it varies
- Special rules for professionals (Bolam/Bolitho), children, and defendants with sudden incapacity
- How courts evaluate risk: likelihood, gravity, and practicality of precautions
- Factual causation (the “but for” test) and legal causation (remoteness)
- Key cases on consent in healthcare, employer duties, and public authorities
- Practical steps to assess, evidence, and manage breach of duty claims

## Core Concepts

### Establishing a Duty of Care

The modern law starts with two touchstones:

- Donoghue v Stevenson [1932] AC 562: a person must take reasonable care to avoid acts or omissions which can reasonably be foreseen as likely to injure their “neighbour” — those closely and directly affected by their actions.
- Caparo Industries plc v Dickman [1990] 2 AC 605: a duty arises where (1) damage is reasonably foreseeable, (2) there is a relationship of proximity between claimant and defendant, and (3) it is fair, just and reasonable to impose a duty.

In many day-to-day settings, duties are well established:

- Drivers owe a duty to other road users to drive with reasonable skill and care, including learners: Nettleship v Weston [1971] 2 QB 691.
- Employers owe employees a duty to provide competent staff, safe equipment, a safe system of work, and proper supervision and training. The duty extends to mental health where foreseeable: Walker v Northumberland County Council [1995] 1 All ER 737; Bux v Slough Metals [1973] 1 WLR 1358.
- Healthcare professionals owe duties to diagnose, treat, and inform with reasonable skill and care, including a duty to warn of material risks affecting consent: Montgomery v Lanarkshire Health Board [2015] UKSC 11.
- Public authorities can owe duties in operational contexts. There is no general immunity: Robinson v Chief Constable of West Yorkshire Police [2018] UKSC 4. Emergency medical services accepting a 999 call owe a duty to individuals to respond with reasonable promptness and care: Kent v Griffiths [2001] QB 36.

Courts are cautious about creating new categories. Always test foreseeability, proximity, and whether imposing a duty is fair, just and reasonable on the facts.

### Breach: The Reasonable Person and Professional Standards

Breach compares the defendant’s conduct to that of the hypothetical reasonable person in the circumstances. The classic statement is in Blyth v Birmingham Waterworks (1856) 11 Exch 781: negligence is doing something a prudent and reasonable person would not do, or failing to do something they would do.

Courts weigh several factors:

- Magnitude of risk: how likely is the harm?
- Gravity of harm: how serious might the consequences be?
- Practicality and cost of precautions: were reasonable steps available?
- Social utility of the activity: does it justify certain risks (without negating the duty)?

Adjustments to the standard

- Children: judged by the standard of a reasonable child of the same age: Mullin v Richards [1998] 1 WLR 1304.
- Sudden incapacity: where a defendant is unaware of a condition that suddenly impairs them, the standard reflects that lack of knowledge: Mansfield v Weetabix Ltd [1998] 1 WLR 1263.
- Learners: still held to the standard of the reasonably competent person in that role (e.g., a reasonable driver): Nettleship v Weston.

Professionals

- The Bolam test: a professional is not negligent if acting in accordance with a responsible body of professional opinion: Bolam v Friern Hospital Management Committee [1957] 1 WLR 582.
- Bolitho refinement: the professional opinion must withstand logical analysis; courts can reject expert evidence that lacks a rational basis: Bolitho v City and Hackney HA [1998] AC 232.
- Consent in healthcare: clinicians must take reasonable care to disclose material risks and reasonable alternatives; materiality is judged by a reasonable person in the patient’s position and the clinician’s knowledge of the patient’s concerns: Montgomery v Lanarkshire Health Board.

Misstatements by non-clinical staff can also amount to breach where responsibility has been assumed and harm follows, as recognised in Darnley v Croydon Health Services NHS Trust [2018] UKSC 50.

### Causation and Remoteness

Factual causation asks whether the damage would have occurred “but for” the breach.

- Barnett v Chelsea & Kensington Hospital Management Committee [1969] 1 QB 428: if the loss would have occurred anyway, factual causation fails.

Where there are multiple causes:

- Material contribution: it is enough that the breach materially contributed to the harm, even if it was not the sole cause: Bonnington Castings Ltd v Wardlaw [1956] AC 613.
- Distinct causes and apportionment: where separate tortfeasors cause different elements of the harm, responsibility can be apportioned: Rahman v Arearose Ltd [2001] QB 351.

Legal causation (remoteness) limits liability to damage of a kind that was reasonably foreseeable at the time of breach.

- The Wagon Mound (No 1) [1961] AC 388: the kind (not the precise manner) of damage must be foreseeable.
- Jolley v Sutton LBC [2000] 1 WLR 1082: the exact sequence of events need not be foreseen if the general kind of harm is foreseeable.
- Thin skull rule: the defendant takes the claimant as found; if the type of injury is foreseeable, the full extent is recoverable even if unusually severe: Smith v Leech Brain & Co [1962] 2 QB 405.

A claimant must also mitigate loss. New, independent acts can break the chain of causation, but ordinary medical treatment or reasonable self-help usually will not.

## Key Examples or Case Studies

### Donoghue v Stevenson [1932] AC 562

- Context: Mrs Donoghue fell ill after consuming ginger beer containing a decomposed snail.
- Point: Established a general duty where harm is reasonably foreseeable to one’s “neighbour”.
- Application: Useful starting point when duties are not covered by a specific category.

### Caparo Industries plc v Dickman [1990] 2 AC 605

- Context: Investors sued auditors for losses after relying on audited accounts.
- Point: Three-stage test of foreseeability, proximity, and whether imposing a duty is fair, just and reasonable.
- Application: Provides a structured analysis for novel duty claims.

### Nettleship v Weston [1971] 2 QB 691

- Context: A learner driver injured her instructor.
- Point: Learners are held to the standard of a reasonably competent driver.
- Application: In road claims, the standard does not drop because the driver is inexperienced.

### Bolam v Friern HMC [1957] 1 WLR 582 and Bolitho v City and Hackney HA [1998] AC 232

- Context: Clinical practice and accepted medical opinion.
- Point: Acting in line with a responsible body of opinion may be reasonable (Bolam), but courts can reject illogical professional opinion (Bolitho).
- Application: Always test expert evidence for logic and consistency with current practice and guidance.

### Montgomery v Lanarkshire Health Board [2015] UKSC 11

- Context: Failure to warn of shoulder dystocia risk in childbirth.
- Point: Patient-focused duty to disclose material risks and reasonable alternatives.
- Application: Record discussions of risks and alternatives; tailor information to the patient’s concerns.

### Robinson v Chief Constable of West Yorkshire Police [2018] UKSC 4

- Context: A passer-by was injured during an arrest.
- Point: No general immunity for police; established duties apply to positive acts causing foreseeable harm.
- Application: For operational decisions affecting individuals, apply ordinary negligence principles.

## Practical Applications

- Map the elements early
  - Duty: Is there an established duty (e.g., driver to road user, clinician to patient, employer to employee)? If not, apply Caparo.
  - Breach: Identify specific acts or omissions and compare with the reasonable person or professional standard.
  - Causation: Ask “but for” the breach, would the damage have occurred? Consider material contribution and any breaks in the chain.
  - Remoteness: Was the kind of harm foreseeable? Apply the thin skull rule where relevant.

- Evidence to gather
  - Incident reports, contemporaneous notes, risk assessments, maintenance logs.
  - Training records, policies, and compliance with guidelines (e.g., GMC guidance, NICE pathways, the Highway Code).
  - Witness statements on what was said or warned (e.g., consent discussions, triage information).
  - Medical records and expert reports linking breach to harm.

- Risk and precautions
  - Show what reasonable precautions were practicable at the time and whether they were taken (speed limits, PPE, supervision, signage, staffing, escalation).
  - For employers: ensure safe systems, suitable equipment, and monitoring of use; review workload and mental health risks (Walker; Bux).

- Professional contexts
  - Cross-check clinical decisions against responsible bodies of opinion and current guidance (Bolam/Bolitho).
  - For consent, document material risks and alternatives tailored to the patient (Montgomery).
  - Non-clinical staff should avoid giving misleading information about waiting times or services (Darnley).

- Public authorities
  - Identify whether the complaint concerns operational acts (where duties may arise) rather than pure policy.
  - Record decisions, resource constraints, and operational steps taken; Kent confirms duties can arise once services are engaged.

- Causation pitfalls
  - Where outcome was inevitable (Barnett), focus may shift to loss of chance or different heads of loss (if available on the facts).
  - Consider whether subsequent events are independent and unforeseeable (potential break) or part of the ordinary sequence (no break).

- Claim management
  - Quantify losses with receipts, wage evidence, and medical prognosis.
  - Check limitation periods and pre-action protocols.
  - Encourage early rehabilitation and mitigation to reduce loss.

## Summary Checklist

- Identify a recognised duty or apply Caparo (foreseeability, proximity, fair, just and reasonable).
- State the relevant standard: reasonable person, reasonable driver, reasonable employer, or professional (Bolam/Bolitho).
- Analyse risk factors: likelihood, gravity, and practicality of precautions.
- For children or sudden incapacity, apply Mullin and Mansfield appropriately.
- In healthcare, document risk disclosure and alternatives (Montgomery).
- Prove factual causation (“but for”), or material contribution where applicable.
- Apply remoteness: kind of harm foreseeable (Wagon Mound); thin skull rule (Smith v Leech Brain).
- Consider apportionment or multiple causes (Bonnington; Rahman).
- Gather and preserve evidence: records, policies, training, witness accounts.
- Address mitigation, quantify loss, and observe procedural steps.

## Quick Reference

| Concept                        | Authority                                                             | Key takeaway                                                               |
| ------------------------------ | --------------------------------------------------------------------- | -------------------------------------------------------------------------- |
| General duty principle         | Donoghue v Stevenson [1932] AC 562                                    | Take reasonable care to avoid foreseeable harm to those closely affected.  |
| Three-stage duty test          | Caparo v Dickman [1990] 2 AC 605                                      | Foreseeability, proximity, and fair, just and reasonable to impose a duty. |
| Breach: reasonable person test | Blyth v Birmingham Waterworks (1856) 11 Exch 781                      | Objective standard; compare conduct with what a prudent person would do.   |
| Professionals                  | Bolam [1957] 1 WLR 582; Bolitho [1998] AC 232                         | Accepted practice may suffice; it must also be logically defensible.       |
| Drivers (including learners)   | Nettleship v Weston [1971] 2 QB 691                                   | Learners judged by the standard of the competent driver.                   |
| Causation                      | Barnett v Chelsea & Kensington [1969] 1 QB 428                        | “But for” test: no liability if the loss would have happened anyway.       |
| Remoteness and thin skull      | Wagon Mound (No 1) [1961] AC 388; Smith v Leech Brain [1962] 2 QB 405 | Kind of harm must be foreseeable; full extent recoverable even if unusual. |


Breach of Duty of Care