Law of Torts
Product Liability at Common Law: Donoghue v. Stevenson, the Three Kinds of Defect, and the Duty to Warn
Product liability is the liability of a manufacturer, and of others in the chain of supply, for harm caused by a defective product. Before 1932 the obstacle was privity: a consumer who had no contract with the manufacturer had no claim against him, however dangerous the article. Donoghue v. Stevenson destroyed that fallacy and established that a manufacturer owes a duty of care directly to the ultimate consumer. The common law claim remains available, but it requires proof of negligence, which the consumer is rarely in a position to give, and that is the gap the Consumer Protection Act, 2019 was enacted to close.
The three kinds of defect, the scope of the duty, who else may be liable, and the defences
1. Donoghue v. Stevenson and the Duty to the Ultimate Consumer
📖 Donoghue v. Stevenson [1932] AC 562 Facts The appellant's friend bought her a bottle of ginger beer at a cafe in Paisley. The bottle was of dark opaque glass, so that its contents could not be seen. After she had drunk part of it, the remains of a decomposed snail floated out as the rest was poured into her glass. She alleged that she suffered shock and severe gastroenteritis. She had no contract with anybody, the ginger beer having been bought by her friend, and she sued the manufacturer. Held The manufacturer owed her a duty of care, and her claim disclosed a good cause of action. Ratio A manufacturer of products, which he sells in such a form as to show that he intends them to reach the ultimate consumer in the form in which they left him, with no reasonable possibility of intermediate examination, and with the knowledge that the absence of reasonable care in the preparation or putting up of the products will result in injury to the consumer's life or property, owes a duty to the consumer to take that reasonable care. The absence of a contract between them is irrelevant. The wider proposition, the neighbour principle, is examined in TORT 028. |
- The narrow rule is confined by its own terms, and each limb matters: the product must be intended to reach the consumer in the form in which it left the manufacturer, and there must be no reasonable possibility of intermediate examination.
- A bare opportunity to inspect is not enough to break the chain. There must have been a reasonable expectation that an inspection would occur, and where one was expected and would have revealed the defect, the chain may be broken.
- The rule has been extended well beyond food in opaque bottles, and now covers vehicles, machinery, chemicals, cosmetics, pharmaceuticals, electrical goods, building materials, toys and packaged goods of every kind.
- The duty extends to the consumer's property as well as his person, though damage to the defective product itself is ordinarily pure economic loss and irrecoverable in negligence.
2. The Three Kinds of Defect
What it is | Illustration | Difficulty of proof | |
Manufacturing defect | The product departs from its own intended design. One item in a batch is faulty | A contaminated bottle, a cracked weld, a wrongly assembled brake, a foreign body in food | The easiest. The defendant's own specification supplies the standard, and res ipsa loquitur often assists |
Design defect | The whole line is unsafe. The product was made exactly as intended, and the intention was wrong | A vehicle that overturns on a normal turn, a heater with no cut out, a toy with a detachable part a child may swallow | The hardest. The court must weigh the risk against the utility of the product and the cost and practicability of a safer design |
Failure to warn | The product is as safe as it can be made, and is dangerous unless used correctly | Missing dosage information, absent contraindications, inadequate assembly instructions, no warning of a known risk | Intermediate. The question is whether the warning given was adequate to the risk and to the likely user |
3. Design Defects and the Risk Utility Balance
- A design defect claim asks the court to say that the product should never have been made as it was, which is a far larger proposition than saying that one item was badly made.
- The factors weighed are the gravity and likelihood of the harm; the utility of the product and whether the risk is inherent in its purpose; whether a safer alternative design was available; the cost and practicability of that alternative; and whether the danger was obvious to the user or capable of being avoided by a warning.
- Compliance with a statutory or industry standard is evidence of reasonable care and is not conclusive. A standard is a floor and not a ceiling, and a manufacturer who knows that the prescribed standard is inadequate for a known risk is not protected by meeting it.
- The state of knowledge at the time of manufacture is what matters. A design is not negligent because a later discovery has shown a better way.
4. The Duty to Warn
- What must be conveyed is the nature of the danger, its severity, how to avoid it, and what to do if it materialises.
- The adequacy of the warning is measured against the likely user. A warning adequate for a trained technician may be wholly inadequate for a household purchaser, and a product likely to be used by children requires warnings framed accordingly.
- Language and prominence matter. A warning in fine print, in a language the likely user does not read, or buried in a manual he will never open, may not discharge the duty at all.
- There is no duty to warn of a danger that is obvious or commonly known. Nobody need be told that a knife is sharp.
- The duty continues after sale. A manufacturer who learns of a danger after the product has been distributed must take reasonable steps to warn those who have it, and in a proper case must recall the product. The failure to recall is itself a breach.
- Where an intermediary is expected to pass on the warning, as with a prescription medicine given to a physician, warning the intermediary may discharge the duty. The principle is recognised in section 87 of the Consumer Protection Act, 2019.
5. Who Else May Be Liable
The defendant | The basis |
The designer | For a defect in the design, whether or not he manufactured the article |
The assembler | For a defective component he supplied or should have checked, and for negligent assembly |
The repairer | For work negligently done, on the ordinary principles of negligence |
The installer | For a negligent installation which made a sound product dangerous |
The distributor or retailer | Where he knew of the defect, ought to have discovered it on a reasonable inspection, or made a representation of his own about the product |
The importer | Frequently the only defendant within the jurisdiction, and treated as the manufacturer for many practical purposes |
6. The Problem of Proof, and the Defences
- The plaintiff must prove negligence, and that is the central weakness of the common law claim. He has no access to the factory, the process, the testing records or the quality control data, all of which are in the defendant's hands.
- Res ipsa loquitur is the usual answer for a manufacturing defect, since a foreign body in a sealed bottle does not ordinarily get there without carelessness. It is of little help for a design defect, where the manufacturer will say that the design was a considered one.
- The defences are that there was no defect at all; that the defect arose after the goods left the defendant; that the plaintiff misused the product or used it contrary to instructions; that an intermediate examination was expected and would have revealed the defect; contributory negligence; and limitation.
- A development risks or state of the art defence is not a formal part of Indian common law, but the same result follows from the rule that negligence is judged by the knowledge available at the time.
⚠ Why Donoghue was not enough, and what came after Donoghue v. Stevenson is rightly treated as the foundation of modern product liability, and it is worth being clear about what it did not do. It removed the privity obstacle, and it did nothing whatever about the burden of proof. A consumer injured by a defective article still has to establish that the manufacturer failed to take reasonable care, and in the ordinary case he has no means of doing so: he knows only that the product failed. Res ipsa loquitur covers part of the gap for manufacturing defects and almost none of it for design defects and failures to warn. That is why jurisdictions across the world moved from negligence to a form of strict or statutory product liability, and why India did the same in Chapter VI of the Consumer Protection Act, 2019, whose central provision is that a manufacturer is liable even if he proves he was not negligent. The common law claim survives and is occasionally useful, particularly where the claimant is not a consumer within the Act, but the statutory action is now the practical route. |
7. The Position Stated Shortly
1. Donoghue v. Stevenson established that a manufacturer owes a duty of care to the ultimate consumer, and that the absence of a contract is no answer.
2. The duty arises where the goods are intended to reach the consumer in the form in which they left the manufacturer, with no reasonable possibility of intermediate examination.
3. A bare opportunity to inspect does not break the chain; there must have been a reasonable expectation that an inspection would occur.
4. A manufacturing defect is a departure from the product's own design, and is the easiest to prove, res ipsa loquitur often assisting.
5. A design defect makes the whole line unsafe, and is judged by weighing the risk against the utility and the cost and practicability of a safer design.
6. Compliance with a statutory or industry standard is evidence of reasonable care and is not conclusive.
7. A failure to warn is a distinct head, and the adequacy of a warning is measured against the likely user, in a language and form he will understand.
8. The duty to warn continues after sale, and may require a recall once a danger becomes known.
9. Designers, assemblers, repairers, installers, importers and, in defined cases, retailers may also be liable.
10. The central weakness of the common law claim is that the plaintiff must prove negligence, which is why the Consumer Protection Act, 2019 created a statutory regime that does not require it.