Products Liability

MBEMax wiki article — paired with the Torts question set on mbemax.com.

One-line summary

A commercial seller of a product is liable in tort for physical harm caused by a defective product — on theories of negligence, strict products liability, breach of warranty, or misrepresentation — and the plaintiff must show the defect, that it existed when the product left the defendant's control, and that it caused the injury.

Mnemonic

M-D-W — Manufacturing, Design, Warning — the three types of defects.

Or the theory set: N-S-W-M — Negligence, Strict liability, Warranty, Misrepresentation.

The strict products-liability rule (Restatement (Second) § 402A / Third § 1)

A commercial seller is liable for physical harm caused by a defective product when:

1. Seller is in the business of selling such products.
2. Product was defective at the time it left defendant's control.
3. Defect is the actual and proximate cause of the injury.
4. Plaintiff is a foreseeable user, consumer, or bystander.

Privity is not required. No need to show fault or negligence in strict-liability theory.

The three types of defect

Manufacturing defect

• Product departs from its intended design.
• Consumer-expectation test: product more dangerous than an ordinary consumer would expect.
• Often proven by showing the particular unit differs from others in the line.

Design defect

• Entire product line is unreasonably dangerous as designed.
• Risk-utility (Restatement Third) test — reasonable alternative design existed and would have reduced foreseeable risks at reasonable cost; the omission renders product not reasonably safe.
• Consumer-expectation test — minority, but alive in many jurisdictions; product more dangerous than ordinary consumer would expect.
• State-of-the-art defense — evidence of industry practice at time of sale; jurisdictions vary on weight.

Warning/instruction defect

• Foreseeable risk of harm could have been reduced by reasonable warnings or instructions, and their absence renders product not reasonably safe.
• Learned intermediary doctrine — in prescription-drug cases, warning duty runs to the physician, not patient (but modern exceptions for direct-to-consumer advertising).
• Obvious danger — no duty to warn of open and obvious risks.
• Post-sale duty to warn — in many jurisdictions, arises when seller learns of danger after sale.

Who can sue / who can be sued

• Plaintiffs: foreseeable users, consumers, bystanders. Privity not required under strict liability.
• Defendants: commercial sellers, manufacturers, distributors, retailers, component-part makers. Casual sellers (one-time garage-sale seller) NOT subject to strict liability.
• Successor liability — generally a successor corporation is not liable, but four exceptions: express/implied assumption, de facto merger, mere continuation, fraudulent transfer to escape liability.

Causation

• Actual cause — but-for / substantial factor.
• Proximate cause — foreseeable harms.
• Intervening misuse — foreseeable misuse does not break causation. Substantial modification may.

Defenses

• Comparative fault — standard partial defense in most jurisdictions.
• Assumption of risk — voluntary encounter of known defect.
• Misuse — unforeseeable misuse.
• Substantial alteration — post-sale substantial change by user or third party.
• Statute of repose — limits claims after product-service-life period.
• Pre-emption — federal regulation (medical devices, vaccines) may preempt state-law claims.

NCBE loves to test

• Strict vs. negligence. Strict liability requires only defect + causation. Negligence requires fault. Plaintiff often pleads both.
• Design defect test split. Risk-utility (Third, modern majority) vs. consumer expectation (Second, some jurisdictions). Question may hinge on which test.
• Reasonable alternative design. Plaintiff must typically show one under Restatement Third — lack of it is often fatal.
• Warning adequacy. Must be conveyed in a way reasonably designed to reach a foreseeable user; language, placement, pictograms matter.
• Bystander recovery. Foreseeable bystanders can recover in strict liability; pure economic loss for commercial buyers typically barred by economic-loss doctrine.
• Commercial seller requirement. One-off sales (garage-sale) don't expose to strict liability.
• Component-part liability. Component maker liable only if (a) component itself was defective or (b) component maker substantially participated in integration that caused defect.
• Learned intermediary in drug cases; direct-to-consumer advertising exception expanding.

Fast hypos

Hypo 1. Car's brakes fail due to a faulty caliper — the specific caliper differed from its intended design. Manufacturing defect — strict liability.

Hypo 2. Space heater causes a fire. Plaintiff shows a safer, cost-effective redesign would have prevented the hazard. Design defect under risk-utility Third Restatement.

Hypo 3. Prescription drug causes heart attacks; adequate warning given to prescribing physicians but not patients. Learned intermediary — no duty to warn patients directly unless DTC advertising exception applies.

Hypo 4. Used-goods store sells a vacuum that shocks user. No active repair/refurbishment. Strict liability varies — some states impose on used-product retailers, others don't.

Case anchors

• Greenman v. Yuba Power Products, 377 P.2d 897 (Cal. 1963) — strict products liability adopted.
• Escola v. Coca-Cola Bottling Co., 150 P.2d 436 (Cal. 1944) — Traynor concurrence foundational.
• Barker v. Lull Engineering, 573 P.2d 443 (Cal. 1978) — dual design-defect tests.
• Soule v. GM Corp., 882 P.2d 298 (Cal. 1994) — cabined consumer-expectation to simple cases.
• MacPherson v. Buick Motor Co., 217 N.Y. 382 (1916) — privity abolished for negligence.
• Vandermark v. Ford Motor Co., 391 P.2d 168 (Cal. 1964) — retailer strict liability.
• Riegel v. Medtronic, 552 U.S. 312 (2008) — preemption of medical-device claims.

See also

• Negligence
• Strict Liability
• Defamation
• Nuisance

Sources

Restatement (Second) of Torts § 402A; Restatement (Third) of Torts: Products Liability §§ 1–4, 6, 10, 16–19; UCC Article 2 (warranty claims — §§ 2-313 to 2-315, 2-607); Greenman v. Yuba Power Products, 377 P.2d 897 (Cal. 1963); MacPherson v. Buick Motor Co., 217 N.Y. 382 (1916); Riegel v. Medtronic, 552 U.S. 312 (2008).