Products Liability
Rule
A manufacturer or seller who places a defective product into the stream of commerce is liable for harm caused by that defect, regardless of privity of contract. Under strict liability (Restatement 2d §402A) no showing of negligence is required for manufacturing defects; design defects and warning defects are analyzed under a negligence-like reasonableness standard under Restatement 3d.
Three Types of Defects (Restatement 3d §2)
1. Manufacturing Defect
The product departs from its intended design even though all possible care was exercised. (Strict liability — no fault required.)
2. Design Defect
Two tests:
- Consumer Expectation Test (Barker prong 1 / ordinary cases): product failed to perform as safely as an ordinary consumer would expect when used in a reasonably foreseeable manner.
- Risk-Utility / Excessive Preventable Danger Test (Barker prong 2 / Restatement 3d): plaintiff shows the foreseeable risks could have been reduced by a reasonable alternative design (RAD); burden then shifts to defendant to justify the design. Factors include: gravity of danger, likelihood, feasibility of alternative, cost, adverse consequences.
3. Warning Defect (Inadequate Instructions or Warnings)
Foreseeable risks could have been reduced by reasonable instructions or warnings, and their omission renders the product not reasonably safe.
- Learned intermediary doctrine: drug manufacturers may warn physicians rather than patients (exception eroded by direct-to-consumer marketing, Perez v. Wyeth).
- Heeding presumption: if warning were adequate, it is presumed plaintiff would have heeded it; burden shifts to defendant.
Elements (general)
- Defendant is engaged in the business of selling or distributing the product.
- Product was defective (manufacturing, design, or warning defect).
- Defect existed when product left defendant’s possession.
- Defect caused plaintiff’s harm.
- Plaintiff suffered damages.
Exceptions / Defenses
- Comparative fault (plaintiff’s misuse or negligent failure to discover defect is not a defense, but other plaintiff conduct reduces recovery).
- Substantial modification by third party (breaks causation chain if modification made product unsafe — Jones v. Ryobi; but warning liability can still exist — Liriano v. Hobart).
- State-of-the-art defense: defendant did not know and could not have known of the risk at the time of sale (Feldman; Vassallo).
- Disclaimers and waivers do not bar products liability claims (Restatement 3d §18).
Policy
- Consumers cannot inspect or test products; they rely on manufacturers.
- Loss-spreading: manufacturer can distribute risk through pricing and insurance.
- Deterrence: incentivizes manufacturers to test, research, and produce safer products.
- Reduces transaction costs of proving negligence through res ipsa.
Key Cases
- MacPherson v. Buick Motor Co — removes privity barrier; manufacturer owes duty to foreseeable users.
- Escola v. Coca Cola Bottling Co. — Traynor, J. concurrence lays groundwork for strict products liability.
- Greenman v. Yuba Power Products — first to impose strict tort liability on manufacturers.
- Sindell v. Abbott Laboratories — market share liability for DES; each manufacturer pays in proportion to market share.