Why Most Defective Product Claims in California Don’t Require Proving Negligence

When people think about suing over a defective product, they often assume they'll need to prove the manufacturer was careless or cut corners somewhere. In California, that's usually not actually required — and the distinction between strict liability and negligence is worth understanding if you've been hurt by a defective product.

Negligence vs. Strict Liability

A negligence claim requires showing the defendant failed to exercise reasonable care — essentially, that they did something a reasonably careful manufacturer wouldn't have done. Strict liability is different: it doesn't ask whether the manufacturer was careful or careless. It asks only whether the product was defective and whether that defect caused the injury during foreseeable use.

Where This Rule Comes From

California adopted strict products liability in Greenman v. Yuba Power Products, Inc. (1963), a landmark case establishing that a manufacturer is liable when a product, defective in its design or manufacture, places a consumer at unreasonable risk — regardless of how much care the manufacturer claims to have taken.

Three Types of Defects

• Manufacturing defects: an individual unit came out different from — and more dangerous than — its intended design, even though the design itself was fine. A batch of the same product with a flaw introduced during production is a classic example.
• Design defects: the product's design itself is unreasonably dangerous, even when manufactured exactly as intended. Courts evaluate this under tests weighing the product's risks against its benefits and the feasibility of a safer alternative design.
• Failure to warn: the product lacked adequate instructions or warnings about a risk that wasn't obvious to an ordinary user.

Why This Matters Practically

Because strict liability doesn't require proving the manufacturer was negligent, these cases often focus more heavily on expert testimony about the product itself — engineering analysis, safety standards, alternative designs that existed — rather than digging into internal corporate decision-making the way a pure negligence case might.

What This Doesn't Mean

Strict liability isn't automatic liability. The injured person still needs to show the product was actually defective, that they were using it in an intended or reasonably foreseeable way, and that the defect caused their injury. A product used in a clearly unintended and unforeseeable way, or an injury caused by something other than the alleged defect, won't automatically succeed just because strict liability applies.

The Takeaway

If you were injured by a product that malfunctioned, broke, or lacked an adequate warning, California's strict liability doctrine means the legal fight is often less about "did the manufacturer mess up" and more about "was the product actually defective" — a meaningfully different, and often more favorable, framework for an injured consumer.

This is general information about California product liability law, not an assessment of a specific product or injury — a free consultation can review the actual facts.