53 Cal. 3d 987, 281 Cal. Rptr. 528, 810 P.2d 549 (Cal. 1991)
Anderson v. Owens-Corning Fiberglas is a landmark California Supreme Court decision that clarifies the contours of strict products liability in failure-to-warn cases.
In a strict products liability failure-to-warn action, must the plaintiff prove that the product's risk was known or knowable in light of the generally recognized and prevailing best scientific and medical knowledge at the time of manufacture and distribution, and is state-of-the-art evidence admissible to establish what was known or knowable?
Yes. In California, strict liability for failure to warn attaches only if the particular risk was known or knowable at the time of manufacture and distribution, in light of the generally recognized and prevailing best scientific and medical knowledge. Plaintiffs bear the burden to prove the existence of such a known or knowable risk, the manufacturer's failure to provide adequate warnings, causation, and damages. Defendants may introduce state-of-the-art evidence to show the limits of scientific and medical knowledge at the time, not to prove reasonableness of conduct per se, but to establish the absence of a known or knowable risk. This rule accords with Restatement (Second) of Torts § 402A comment j and California strict liability precedent distinguishing informational defects from design and manufacturing defects.
The California Supreme Court held that in strict liability failure-to-warn cases, the risk must have been known or knowable at the time of manufacture and distribution. Evidence of the state of scientific and medical knowledge at the relevant time—state-of-the-art evidence—is admissible to determine whether the risk was known or knowable.
Anderson crystallizes a core principle of modern products liability: in failure-to-warn cases, strict liability is not absolute and turns on the state of knowledge at the time of manufacture and distribution. It gives plaintiffs and defendants clear burdens—plaintiffs must show the risk was known or knowable; defendants may counter with state-of-the-art evidence. The case guides jury instructions, motions in limine, and expert proof in toxic torts and other warning cases. For law students, Anderson is essential for understanding how California harmonizes strict liability with practical and evidentiary constraints, distinguishes failure-to-warn from design/manufacturing defects, and aligns with Restatement comment j. Its reasoning reverberates through later California cases addressing pharmaceuticals and complex product risks.