evidence that he or she was injured while the product was being used in an
intended or reasonably foreseeable manner. If this prima facie burden is met, the
burden of proof shifts to the defendant to prove that the plaintiff’s injury resulted
from a misuse of the product. (See Perez v. VAS S.p.A. (2010) 188 Cal.App.4th
658, 678 [115 Cal.Rptr.3d 590] [strict liability design defect risk-beneﬁt case].) See
also CACI No. 1245, Affırmative Defense—Product Misuse or Modiﬁcation.
Product misuse is a complete defense to strict products liability if the defendant
proves that an unforeseeable abuse or alteration of the product after it left the
manufacturer’s hands was the sole cause of the plaintiff’s injury. (Campbell v.
Southern Paciﬁc Co. (1978) 22 Cal.3d 51, 56 [148 Cal.Rptr. 596, 583 P.2d 121];
see CACI No. 1245.) Misuse or modiﬁcation that was a substantial factor in, but
not the sole cause of, plaintiff’s harm may also be considered in determining the
comparative fault of the plaintiff or of third persons. See CACI No. 1207A, Strict
Liability—Comparative Fault of Plaintiff, and CACI No. 1207B, Strict
Liability—Comparative Fault of Third Person.
The last bracketed paragraph is to be used in prescription drug cases only.
Sources and Authority
• “[T]he manufacturer has a duty to use reasonable care to give warning of the
dangerous condition of the product or of facts which make it likely to be
dangerous to those whom he should expect to use the product or be endangered
by its probable use, if the manufacturer has reason to believe that they will not
realize its dangerous condition.” (Putensen v. Clay Adams, Inc. (1970) 12
Cal.App.3d 1062, 1076–1077 [91 Cal.Rptr. 319].)
• “Negligence law in a failure-to-warn case requires a plaintiff to prove that a
manufacturer or distributor did not warn of a particular risk for reasons which
fell below the acceptable standard of care, i.e., what a reasonably prudent
manufacturer would have known and warned about.” (Chavez v. Glock, Inc.
(2012) 207 Cal.App.4th 1283, 1305 [144 Cal.Rptr.3d 326], internal citation
• “Negligence and strict products liability are separate and distinct bases for
liability that do not automatically collapse into each other because the plaintiff
might allege both when a product warning contributes to her injury.” (Conte v.
Wyeth, Inc. (2008) 168 Cal.App.4th 89, 101 [85 Cal.Rptr.3d 299].)
• “The ‘known or knowable’ standard arguably derives from negligence
principles, and failure to warn claims are generally ‘ “rooted in negligence” to a
greater extent than’ manufacturing or design defect claims. Unlike those other
defects, a ‘ “warning defect” relates to a failure extraneous to the product itself’
and can only be assessed by examining the manufacturer’s conduct. These
principles notwithstanding, California law recognizes separate failure to warn
claims under both strict liability and negligence theories. In general, a product
seller will be strictly liable for failure to warn if a warning was feasible and the
absence of a warning caused the plaintiff’s injury. Reasonableness of the seller’s
failure to warn is immaterial in the strict liability context. Conversely, to prevail
CACI No. 1222 PRODUCTS LIABILITY