Winning a product liability case rarely comes down to whether a product was actually dangerous, it usually comes down to whether you can prove it, with the product itself as evidence, before it gets thrown away, repaired, or lost. California law makes manufacturers strictly liable for defective products, but strict liability doesn’t mean automatic; you still have to build the case.
Quick answer: To prove a California product liability claim, you generally need to show the product was defective, you were using it as intended, the defect caused your injury, and you weren’t aware of the defect. The single most important, and most commonly lost, piece of evidence is the product itself, preserve it immediately and don’t repair, discard, or return it.
California's Strict Liability Rule
California has held manufacturers strictly liable for defective products since the landmark 1963 case Greenman v. Yuba Power Products, which established that a manufacturer is liable when a product it places on the market, expecting it to be used without inspection for defects, turns out to have a defect that causes injury. Strict liability means you don’t have to prove the manufacturer was careless or negligent, only that the product was defective and that defect caused your injury, a significantly lower bar than ordinary negligence, though still one that requires real evidence to clear. The rule reflects a deliberate policy choice: manufacturers, not injured consumers, are in the best position to bear the cost of a defective product and to prevent defects from reaching the market in the first place, since they control the design and manufacturing process from start to finish.
Types of Product Defects
A defect generally falls into one of three categories. A manufacturing defect means a specific unit departed from its intended design during production, like a batch of car parts made with the wrong material. A design defect means the product’s overall design is unreasonably dangerous even when made exactly as intended, such as a piece of machinery with an inadequately guarded blade. A warning defect means the product’s risks weren’t adequately disclosed to users. These theories apply to pharmaceuticals too, though drug cases involve their own specific legal doctrines, our guide on how defective drugs reach consumers covers that territory in depth. This page focuses on the broader category of consumer products: vehicles and auto parts, machinery and tools, appliances, and children’s products among them.
The Most Important Evidence: Preserve the Product
More product liability claims are weakened by a discarded or repaired product than by almost any other single mistake. Once a defective product is thrown away, returned to the manufacturer, or repaired, the physical evidence of the defect itself is often gone for good, and reconstructing what actually went wrong becomes far harder without it. Keep the product exactly as it was at the time of the injury, including any packaging, instructions, or parts that broke off, and resist any pressure from a manufacturer or retailer to return it for a “replacement” before your case has been evaluated. Photograph it from multiple angles immediately, note the model and serial number, and store it somewhere it won’t be further damaged, altered, or thrown out by someone else in your household who doesn’t realize its importance.
Still have the product that injured you? Don’t repair it, return it, or throw it away. Call (949) 776-2856 for a free consultation.
Expert Testimony and Recall History
Beyond the product itself, two other sources of evidence tend to make or break these cases. An engineering or industry expert can examine the product and explain, in terms a jury can follow, exactly how and why it failed and why that failure reflects a defect rather than misuse or normal wear. Separately, checking whether a product has been the subject of a recall or similar complaints through databases maintained by agencies like the Consumer Product Safety Commission or the National Highway Traffic Safety Administration can reveal whether your injury was an isolated incident or part of a broader, already-known pattern, and a documented pattern of similar failures is often powerful evidence that the manufacturer knew, or should have known, about the defect.
What You Need to Prove
Putting it together, a California product liability claim generally requires showing that the defendant manufactured, designed, or distributed the product, that the product was defective, that you were using it in a reasonably intended or foreseeable way, and that the defect actually caused your injury. One nuance worth knowing: unlike the original strict liability rule, California now allows a defendant to argue that your own misuse of the product contributed to your injury, reducing rather than eliminating your recovery under the state’s comparative fault rules, so how you were using the product at the time still matters even in a strict liability case.
Injured by a defective product? We can help you build the evidence your claim needs. Call (949) 776-2856 for a free case review.
Talk to a California Product Liability Lawyer
Facing a manufacturer with deep legal resources on your own is rarely a fair fight, and the evidence that wins these cases needs to be secured immediately. DKB Lawyers helps injured consumers throughout California preserve critical evidence and pursue full compensation.
Call (949) 776-2856 for a free consultation, or use our contact form.