Black-letter propositions
- 01
Manufacturing defect means deviation from intended design.
- 02
Design defect commonly uses consumer expectation, risk-utility, or a reasonable-alternative-design formulation.
- 03
Warning defect requires inadequate warning of nonobvious foreseeable risk; sophisticated users, learned intermediaries, and obvious risks can matter.
- 04
Commercial sellers in the distribution chain can be liable even without negligence; casual sellers generally are not.
- 05
Defect must exist when leaving defendant control and cause injury during foreseeable use or misuse.
- 06
Comparative fault, assumption, substantial alteration, federal preemption, and disclaimers have doctrine-specific effects.
Use this attack sequence under time
Frame the issue
Identify product, claimant, and each seller.
Resolve the next checkpoint
Choose manufacturing, design, or warning theory.
Resolve the next checkpoint
State test and defect evidence.
Resolve the next checkpoint
Prove control-time defect and foreseeable use.
Finish the conclusion
Analyze cause, alteration, and defenses.
Common wrong turns
- A safe alternative is not necessary for every design test unless the governing rule requires it.
- Product misuse can be foreseeable.
- Contract disclaimers generally cannot eliminate personal-injury strict tort liability.
Worked example
One bottle in a properly designed batch explodes because it was filled at triple pressure.
The individual unit deviated from design, supporting a manufacturing-defect claim if the defect existed when it left the supplier and caused injury.
Practice this topic
Products liability
Cornell defines products liability as the legal responsibility imposed on parties along the chain of manufacture for damage caused by a product, from the component-part manufacturer to the wholesaler and retailer. The prima facie case against a commercial seller is that the defendant sells a product the plaintiff uses, the plaintiff is injured, the product was defective when sold, and the defect was an actual and proximate cause.
Claims can be based on negligence, strict liability or breach of warranty of fitness, depending on the jurisdiction, because there is no federal products liability law. The Model Uniform Products Liability Act was published in 1979 to encourage uniformity.
Defect types
Cornell lists three types of defects that create liability. Design defects exist before the product is made, so the item may work but be unreasonably dangerous because of a design flaw. Manufacturing defects occur during production and affect only some products of the same type. Defects in marketing involve improper instructions and failures to warn of latent dangers. For design defects, courts in different jurisdictions use the consumer expectation test, the risk-utility test or a mix, and Cornell says products liability is generally a strict liability offense.
Products liability has stretched beyond tangible goods to include intangibles such as gas, naturals such as pets, real estate such as a house, and writings such as navigational charts. Identify the defect type first, since each has its own proof.
Frequently asked questions
What is the controlling rule for manufacturing, design, warning, warranty, and defenses?+
Products liability requires a specific defect theory, commercial supplier, defect at distribution, foreseeable use, causation, and applicable defenses.
How should I analyze manufacturing, design, warning, warranty, and defenses on the bar exam?+
Identify product, claimant, and each seller. Choose manufacturing, design, or warning theory. State test and defect evidence. Prove control-time defect and foreseeable use. Analyze cause, alteration, and defenses.
Who can be liable in products liability?+
Parties along the chain of manufacture, from component-part manufacturers to wholesalers and retailers, according to Cornell.
What is the prima facie case against a commercial seller?+
The defendant sells a product the plaintiff uses, the plaintiff is injured, the product was defective when sold, and the defect actually and proximately caused the injury.
On what theories can a products claim rest?+
Negligence, strict liability or breach of warranty of fitness, depending on the jurisdiction, since there is no federal products liability law.
Is there a federal products liability law?+
No. Cornell says there is no federal law, which led to the Model Uniform Products Liability Act published in 1979.
What is a design defect?+
A defect that exists before the product is manufactured, where the item may serve its purpose but is unreasonably dangerous because of a design flaw.