Product liability - Product liability in negligence

Learning Outcomes

This article outlines the common law principles governing liability for defective products through the tort of negligence. It focuses on how a duty of care is established between manufacturers and consumers, what constitutes a breach of that duty, and the rules surrounding causation and remoteness of damage. Your understanding of these elements is essential for answering SQE1 questions involving harm caused by faulty goods, enabling you to identify liability and apply relevant legal rules effectively. It also clarifies the limits on recoverable loss in product cases (notably the restriction on pure economic loss, including the defective product itself), and highlights evidential tools sometimes available to claimants (such as drawing an inference of negligence where the cause is unknown and the product was under the defendant’s control). You should be able to distinguish fault-based negligence from strict liability under the Consumer Protection Act 1987 and recognise who may fall within “manufacturer” for the narrow rule, including assemblers, installers, repairers and suppliers who ought to have inspected the goods.

SQE1 Syllabus

For SQE1, you are required to understand how negligence principles apply to product liability claims, with a focus on the following syllabus points:

• Establishing the manufacturer's duty of care to the consumer, referencing the 'neighbour principle' and its application.
• Identifying the standard of care expected from a reasonable manufacturer.
• Determining when a breach of duty occurs in the context of defective products.
• Applying the rules of causation (factual and legal) to link the defect to the claimant's loss.
• Recognising relevant defences available to a manufacturer in a negligence claim.
• Assessing whether intermediate examination was reasonably to be expected and, if so, how it may break the chain of causation.
• Understanding the limits on recoverable loss in product claims, particularly the exclusion of pure economic loss and damage to the defective product itself.
• Using evidential concepts such as res ipsa loquitur and the effect of criminal convictions in civil proceedings where appropriate.
• Distinguishing negligence-based claims from strict liability under the Consumer Protection Act 1987.

Test Your Knowledge

Attempt these questions before reading this article. If you find some difficult or cannot remember the answers, remember to look more closely at that area during your revision.

1. What principle established the manufacturer's duty of care towards the ultimate consumer?
2. True or False: A manufacturer is only liable for defects they actually knew about.
3. Can a retailer generally be held liable in negligence for supplying a defective product manufactured by someone else?
4. What test is primarily used to establish factual causation in negligence?

Introduction

When a product causes harm due to a defect, the injured party may seek compensation through the law of tort. While statutory provisions like the Consumer Protection Act 1987 offer a route based on strict liability (covered elsewhere), claims can also be brought under the common law tort of negligence. This requires the claimant to prove that the defendant (often the manufacturer) owed a duty of care, breached that duty, and that this breach caused the claimant's damage. Understanding these common law principles is essential for SQE1.

Negligence-based product claims typically allow recovery for personal injury and damage to other property caused by the defective product. However, pure economic loss is generally irrecoverable in tort; this includes the cost of repairing or replacing the defective product itself. The duty of care is well-established in this sphere and does not ordinarily require the Caparo three-stage test. The analysis therefore focuses on the narrow rule from Donoghue v Stevenson, breach of duty judged against a reasonable manufacturer, and causation and remoteness, coupled with applicable defences.

Key Term: Manufacturer
In product liability negligence, this term is interpreted broadly to include not just the original maker but also assemblers, installers, repairers, and sometimes even suppliers if they ought to have inspected the goods.

Key Term: Product
This encompasses the item itself and includes packaging, labelling, and instructions provided with it. Liability can arise from defects in any of these components.

Key Term: Ultimate Consumer
Refers to anyone who could foreseeably be harmed by a defect in the product, not just the person who purchased it.

Duty of Care in Product Liability

The basis for a manufacturer's duty of care in negligence was laid down in the landmark case of Donoghue v Stevenson [1932] AC 562. This case established the 'neighbour principle', requiring individuals to take reasonable care to avoid acts or omissions that could foreseeably injure those closely and directly affected by their actions.

Specifically relating to products, Donoghue v Stevenson established the 'narrow rule': a manufacturer owes a duty of care to the ultimate consumer of their product. This duty arises when the product is intended to reach the consumer in the form it left the manufacturer, with no reasonable possibility of intermediate examination that would reveal the defect.

The categories captured by “manufacturer” are deliberately wide. Duty has been found against:

• assemblers and those who fit component parts into a finished product;
• installers whose work creates or perpetuates a danger present in the finished item;
• repairers and service engineers whose negligent work leaves a product dangerous; and
• suppliers who, given the nature/age of the goods or specific warnings, ought reasonably to have inspected or tested them before supply.

Illustrative examples include liability for a lift service contractor whose negligent maintenance left the lift dangerous, and the imposition of duty on a car supplier who sold a vehicle with defective steering where a competent inspection should have revealed the defect. In the same way, the concept of “product” includes its packaging, warnings, and instructions; a failure to provide adequate warnings about known hazards can amount to negligence.

The class of persons protected as “ultimate consumers” extends beyond purchasers to anyone foreseeably affected by a defect, such as passengers, bystanders, or owners of property damaged by the product. It follows that claimants do not need privity of contract with the manufacturer; negligence fills the gap where contract and consumer law do not reach.

Intermediate Examination

A key aspect of the narrow rule is the possibility of intermediate examination. If it is reasonably anticipated that someone (like a retailer or the consumer themselves) will examine the product before use in a way that should reveal the defect, the manufacturer's duty may be discharged. The chain of causation might be broken.

However, the mere possibility of examination is not enough; there must be a reasonable probability or expectation of such an examination occurring, and it must be the type of examination likely to reveal the specific defect. If the defect is hidden and unlikely to be discovered through reasonable inspection, the manufacturer’s duty remains. Where the manufacturer expressly indicates that the item should be tested before use and an intermediary fails to carry that out, liability can fall on the intermediary and the chain to the original manufacturer may be broken.

Sometimes extended time lapses, alterations, or later handling between manufacture and injury complicate the analysis. If, for example, the defect may have arisen after manufacture or during fitting by a third party, the original manufacturer may not be factually causative of the harm. Conversely, routine, non-revealing inspection (or an inspection that would not reasonably detect the defect) will not assist a defendant.

Worked Example 1.1

A company manufactures sealed plastic bottles of fruit juice. Due to a fault in the bottling process, a shard of glass enters one bottle. The bottle is sold by a retailer to Chloe, who gives it to her friend, David. David drinks the juice and swallows the glass, suffering injury. Is an examination by Chloe or the retailer likely to break the chain of causation?

Answer:
Probably not. The product is sealed, and the defect (glass inside) is hidden. There is no reasonable probability that either the retailer or Chloe would open and inspect the contents in a way that would reveal the glass shard before David consumed it. The manufacturer likely still owes a duty to David.

Worked Example 1.2

Beta Ltd manufactures electric kettles. One kettle model has a known design flaw where the handle can detach when the kettle is full of boiling water, but Beta Ltd decides not to recall the model due to cost. Sarah purchases one, and the handle detaches, causing her severe burns. Has Beta Ltd breached its duty?

Answer:
Yes, very likely. A reasonable manufacturer, knowing of such a dangerous defect, would be expected to take steps like recalling the product or issuing prominent warnings. Failing to do so falls below the required standard of care.

Worked Example 1.3

Ahmed buys a ladder manufactured by LadderCo. Due to a negligent manufacturing process, a rung is weakened. While Ahmed is using the ladder correctly, the rung breaks, causing him to fall and break his arm. Medical evidence shows Ahmed has unusually brittle bones, making the fracture much worse than it would otherwise have been. Is LadderCo liable for the full extent of Ahmed's injury?

Answer:
Yes. It is reasonably foreseeable that a defective ladder rung breaking could cause a user to fall and suffer personal injury (like a broken arm). Although the extent of Ahmed's injury was unforeseeable due to his brittle bones, the type of injury (a fracture from a fall) was foreseeable. Under the 'egg-shell skull' rule, LadderCo must take the victim as they find them and is liable for the full extent of the injury.

Worked Example 1.4

ClearChem supplies laboratory chemicals to a college. The original producer includes a prominent label stating the chemical must be tested before student use. The college fails to test and a student is injured by contamination. Can the original producer avoid liability on the basis of intermediate examination?

Answer:
Potentially yes. Where a reasonable and expected intermediate examination (explicitly indicated by the producer) would likely have detected the danger and the intermediary fails to carry it out, the chain to the producer may be broken. The intermediary who negligently failed to examine can be liable.

Breach of Duty

A manufacturer breaches their duty of care if they fail to meet the standard of a reasonably competent manufacturer in the same field. This involves taking reasonable steps to ensure the product is safe for its intended use.

The standard of care is objective. Courts evaluate the precautions a reasonable manufacturer would have taken, having regard to:

• the magnitude and likelihood of the risk created by the product or its instructions;
• the seriousness of potential harm (a higher risk of serious injury demands more robust precautions);
• the practicability and cost of precautions (feasible safety steps should be implemented);
• compliance with standards, codes and regulations (compliance is persuasive but not conclusive—unreasonable industry practice may still be negligent);
• the state of knowledge at the time of production (including knowledge of risks requiring warnings or design changes);
• post-market surveillance, responses to incident data and reasonable recalls/warnings when widespread hazards emerge.

Inadequate warnings and instructions can amount to negligence where hazards are known or ought to be known. Warnings must be sufficiently prominent and intelligible, and instructions must address reasonably foreseeable uses and misuses.

Establishing Breach

Proving breach can be challenging for claimants as manufacturing processes are often complex and not directly observable. Courts may consider:

• The design of the product.
• The manufacturing process and quality control measures.
• The adequacy of warnings or instructions provided.
• Compliance with industry standards and regulations (though compliance is not conclusive proof of reasonable care).

In appropriate cases, a claimant may invite the court to infer negligence where the precise cause is unknown but the incident is the kind that ordinarily does not occur without negligence and the product was under the defendant’s control. The inference does not automatically fix liability; defendants can rebut it by showing reasonable care or a non-negligent explanation.

Additionally, criminal convictions involving negligence (for example, under road traffic law) can be used in civil actions as prima facie evidence that the defendant fell below the standard of care. The burden then shifts to the defendant to displace the inference.

Worked Example 1.5

During normal use, a domestic gas canister suddenly ruptures and explodes. The claimant cannot identify the precise manufacturing error but adduces evidence that such canisters do not ordinarily explode absent negligence. Can breach be inferred?

Answer:
Potentially. If the canister was under the defendant’s control up to supply, the cause of the accident is unknown, and the accident is of a type that ordinarily does not occur without negligence, a court may draw an inference of negligence subject to rebuttal. The manufacturer can avoid liability by establishing a non-negligent cause or demonstrating reasonable care in design, manufacture, and testing.

Causation

As in any negligence claim, the claimant must prove that the manufacturer's breach of duty caused the damage suffered. This involves establishing both factual and legal causation.

Factual Causation ('But For' Test)

The claimant must show that, but for the manufacturer's negligence (leading to the defect), the damage would not have occurred. Disputes often arise where time lapses, later handling, or possible alternative causes make it uncertain whether the manufacturer’s breach was causative. A defect that may have arisen after manufacture (for example, during fitting by another party or through fair wear and tear years later) will usually break causation against the original manufacturer.

Where multiple factors combine to produce the harm, the law recognises situations in which a claimant need not show the defendant’s breach was the sole cause. If the breach materially contributed to the damage, liability can arise even if other (non-negligent) factors also played a role. By contrast, adding an extra possible cause where several different possible independent causes exist—without showing the defendant’s breach actually caused or materially contributed to the harm—will not suffice.

Legal Causation (Remoteness)

The type of damage suffered must be a reasonably foreseeable consequence of the manufacturer's breach. The principle from The Wagon Mound (No 1) applies: only loss of a kind that was reasonably foreseeable is recoverable. The ‘similar in type’ approach permits recovery when the general type of injury was foreseeable even if the precise mechanism was not. The ‘egg-shell skull’ rule applies: once the type of injury is foreseeable, the defendant is liable for the full extent of the harm, even if aggravated by the claimant’s particular vulnerabilities.

Intervening acts can break the chain of causation if they are entirely unreasonable or not a foreseeable consequence of the initial negligence. Foreseeable misuse will often be relevant to duty and breach (necessitating instructions/warnings), whereas extraordinary misuse may break causation.

Application to Product Claims

• A long interval between manufacture and the incident can undermine factual causation if the item was altered or the defect likely arose later.
• Foreseeable injury from dangerous products lacking adequate warnings can be legally causative; by contrast, injury from an obvious risk voluntarily assumed may be outside duty or be subject to defences.
• Damage to other property caused by a defective product is recoverable; however, damage to the defective product itself is pure economic loss and is not recoverable in negligence.

Worked Example 1.6

A toughened windscreen fitted to a car shatters and injures a driver more than a year after purchase. Evidence suggests improper fitting could strain the glass, and the cause is uncertain. Can the original glass manufacturer be held liable?

Answer:
Unlikely on these facts. The lapse of time, potential improper fitting, and uncertainty about whether the manufacturing process caused the failure make it difficult to prove factual causation against the original manufacturer. If a later fitting error likely caused the defect, liability would fall on the fitter rather than the original producer.

Defences to Negligence Claims

Manufacturers facing negligence claims for defective products may raise general negligence defences.

Contributory Negligence

If the claimant failed to take reasonable care for their own safety, and this contributed to their injury (e.g., misusing the product despite clear warnings), their damages may be reduced under the Law Reform (Contributory Negligence) Act 1945. The focus is on contribution to the damage, not the accident itself. For example, ignoring prominent safety instructions or using the product contrary to clear warnings can justify a reduction if this worsened the harm.

Voluntary Assumption of Risk (Volenti Non Fit Injuria)

This defence requires showing the claimant had full knowledge of the specific risk caused by the defect and voluntarily agreed to accept that risk. It is rarely successful in product liability cases, as consumers do not typically consent to defects. The defence is hard to establish unless the risk was obvious and the claimant freely chose to encounter it in the full understanding of its nature and extent.

Exclusion of Liability

Attempts by manufacturers (acting in the course of business) to exclude liability for death or personal injury caused by negligence are void under the Unfair Contract Terms Act 1977 (for business-to-business contexts) or the Consumer Rights Act 2015 (for trader-to-consumer contexts). Exclusions for other types of damage (e.g., property damage) are subject to tests of reasonableness (UCTA) or fairness (CRA). To be effective, notices or terms must be brought to the claimant’s attention before the incident and clearly cover the type of loss in issue.

Other Arguments

• Misuse: Unforeseeable and wholly unreasonable misuse of a product may break causation; foreseeable misuse should be addressed through design and warnings.
• Illegality: Where a claimant’s injury arises in the course of criminal conduct, public policy may preclude recovery; in product claims this is uncommon and fact-sensitive.

Exam Warning

Remember that a claim in negligence focuses on the manufacturer's fault (failure to take reasonable care). This differs significantly from a claim under the Consumer Protection Act 1987, which imposes strict liability (liability without needing to prove fault) for damage caused by defective products. Ensure you apply the correct principles depending on the basis of the claim mentioned in an SQE question.

Key Point Checklist

This article has covered the following key knowledge points:

• Product liability in negligence is based on the common law duty of care owed by manufacturers to consumers.
• The duty originates from the 'neighbour principle' and 'narrow rule' in Donoghue v Stevenson.
• The duty applies broadly to manufacturers, assemblers, repairers, and sometimes suppliers.
• Liability covers personal injury and damage to other property, but not pure economic loss (including damage to the defective product itself).
• A reasonable probability of intermediate examination that would likely reveal the defect may break the chain of causation against the original manufacturer; otherwise, hidden defects remain the manufacturer’s responsibility.
• Breach of duty occurs if the manufacturer fails to meet the standard of a reasonably competent manufacturer, including adequate design, testing, quality control, warnings, and reasonable post-market action.
• Claimants must establish factual causation (typically the 'but for' test; sometimes by showing a material contribution to damage) and legal causation (foreseeability of the type of harm, including the egg-shell skull rule).
• Evidential tools may assist in proving breach: inferences can be drawn where accidents of a type not expected without negligence occur and the cause is unknown; criminal convictions involving negligence are admissible in civil cases.
• Defences like contributory negligence may apply, consent is rare, and exclusions of liability for personal injury are generally void or strictly controlled.

Key Terms and Concepts

• Manufacturer
• Product
• Ultimate Consumer