California Civil Jury Instructions (CACI)

1245. Affirmative Defense—Product Misuse or Modification

[Name of defendant] claims that [he/she/it] is not responsible for [name of plaintiff]’s claimed harm because the [product] was [misused/ [or] modified] after it left [name of defendant]’s possession. To succeed on this defense, [name of defendant] must prove that:

1. The [product] was [misused/ [or] modified] after it left [name of defendant]’s possession; and

2. The [misuse/ [or] modification] was so highly extraordinary that it was not reasonably foreseeable to [name of defendant], and therefore should be considered as the sole cause of [name of plaintiff]’s harm.

New April 2009; Revised December 2009, June 2011

Directions for Use

Give this instruction if the defendant claims a complete defense to strict product liability because the product was misused or modified after it left the defendant’s possession and control in an unforeseeable way, and the evidence permits defendant to argue that the subsequent misuse or modification was the sole cause of the plaintiff’s injury. (See Campbell v. Southern Pacific Co. (1978) 22 Cal.3d 51, 56 [148 Cal.Rptr. 596, 583 P.2d 121].) If misuse or modification was a substantial factor contributing to, but not the sole cause of, plaintiff’s harm, there is no complete defense, but the conduct of the plaintiff or of third parties may be considered under principles of comparative negligence or fault. (See Torres v. Xomox Corp. (1996) 49 Cal.App.4th 1, 15—21 [56 Cal.Rptr.2d 455].) See CACI No. 1207A, Strict Liability—Comparative Fault of Plaintiff, and CACI No. 1207B, Strict Liability—Comparative Fault of Third Person.

Third party negligence that is the immediate cause of an injury may be viewed as a superseding cause if it is so highly extraordinary as to be unforeseeable. Product misuse or modification may be deemed to be a superseding cause, which provides a complete defense to liability. (See Torres, supra, 49 Cal.App. 4th at pp. 18—19.) Element 2 incorporates this aspect of superseding cause as an explanation of what is meant by “sole cause.” If misuse or modification truly were the sole cause, the product would not be defective.

It would appear that at least one court views superseding cause as a different standard from sole cause. (See Perez v. VAS S.p.A. (2010) 188 Cal.App.4th 658, 685 [115 Cal.Rptr.3d 590] [product misuse may serve as a complete defense when the misuse was so unforeseeable that it should be deemed the sole or superseding cause], original italics.) For an instruction on superseding cause that may perhaps be adapted for product misuse or modification, see CACI No. 432, Affırmative Defense—Causation: Third-Party Conduct as Superseding Cause.

Sources and Authority

  • “ ‘[T]he law now requires a manufacturer to foresee some degree of misuse and abuse of his product, either by the user or by third parties, and to take reasonable precautions to minimize the harm that may result from misuse and abuse… [T]he extent to which designers and manufacturers of dangerous machinery are required to anticipate safety neglect presents an issue of fact… [A] manufacturer owes a foreseeable user of its product a duty to warn of risks of using the product.’ ” (Wright v. Stang Mfg. Co. (1997) 54 Cal.App.4th 1218, 1235 [63 Cal.Rptr.2d 422].)
  • “[P]roduct misuse [is] a defense to strict products liability only when the defendant prove[s] that an unforeseeable abuse or alteration of the product after it left the manufacturer’s hands was the sole reason that the product caused injury.” (Campbell, supra, 22 Cal.3d at p. 56, original italics, internal citations omitted.)
  • “[S]trict liability should not be imposed upon a manufacturer when injury results from a use of its product that is not reasonably foreseeable.” (Cronin v. J.B.E. Olson Corp. (1972) 8 Cal.3d 121, 126 [104 Cal.Rptr. 433, 501 P.2d 1153].)
  • “[Defendant] contends . . . that it cannot be held liable for any design defect because the accident was attributable to the misuse of the rewinder by [employer] and [plaintiff]. In order to avoid liability for product defect, [defendant] was required to prove, as an affirmative defense, that [employer]’s and [plaintiff]’s misuse of the machine . . . was an unforeseeable, superseding cause of the injury to [plaintiff].” Perez, supra, 188 Cal.App.4th at pp. 679—680.)
  • “[P]roduct misuse may serve as a complete defense when the misuse ‘was so unforeseeable that it should be deemed the sole or superseding cause.’ . . . ‘[T]he defense of “superseding cause . . . ” . . . absolves a tortfeasor, even though his [or her] conduct was a substantial contributing factor, when an independent event intervenes in the chain of causation, producing harm of a kind and degree so far beyond the risk the original tortfeasor should have foreseen that the law deems it unfair to hold him responsible. [Citations.]’ Here, the trial court reasonably concluded, in substance, that [plaintiff]’s misuse of the rewinder was so extreme as to be the sole cause of his injury. That conclusion dispensed with the need to apply principles of comparative fault.” (Perez, supra, 188 Cal.App.4th at p. 685, original italics.)
  • “Third party negligence which is the immediate cause of an injury may be viewed as a superseding cause when it is so highly extraordinary as to be unforeseeable. ‘The foreseeability required is of the risk of harm, not of the particular intervening act. In other words, the defendant may be liable if his conduct was ‘a substantial factor’ in bringing about the harm, though he neither foresaw nor should have foreseen the extent of the harm or the manner in which it occurred.’ It must appear that the intervening act has produced ‘harm of a kind and degree so far beyond the risk the original tortfeasor should have foreseen that the law deems it unfair to hold him responsible.’ ” (Torres, supra, 49 Cal.App.4th at pp. 18—19, internal citations omitted.)
  • “ ‘Misuse’ is a defense only when that misuse is the actual cause of the plaintiff’s injury, not when some other defect produces the harm. This causation is one of the elements of the ‘misuse’ affirmative defense and thus the burden falls on the defendant to prove it.” (Huynh v. Ingersoll- Rand (1993) 16 Cal.App.4th 825, 831 [20 Cal.Rptr.2d 296], internal citation omitted.)
  • “[Defendant] further contends that [plaintiff]’s injuries arose not from a defective product, but rather, from his parents’ modification of the product or their negligent supervision of its use. These arguments cannot be advanced by demurrer. Creation of an unreasonable risk of harm through product modification or negligent supervision is not clearly established on the face of [plaintiff]’s complaint. Instead, these theories must be pled as affirmative defenses.” (Williams v. Beechnut Nutrition Corp. (1986) 185 Cal.App.3d 135, 141 [229 Cal.Rptr. 605].)
  • “[T]here are cases in which the modification of a product has been determined to be so substantial and unforeseeable as to constitute a superseding cause of an injury as a matter of law. However, foreseeability is a question for the jury unless undisputed facts leave no room for a reasonable difference of opinion. Thus, the issue of superseding cause is generally one of fact. Superseding cause has been viewed as an issue of fact even in cases where ‘safety neglect’ by an employer has increased the risk of injury, or modification of the product has made it more dangerous.” (Torres, supra, 49 Cal.App.4th at p. 19, internal citations omitted.)

Secondary Sources

Witkin, Summary of California Law (10th ed. 2005) Torts, § 1530

Haning et al., California Practice Guide: Personal Injury, Ch. 2(II)-D, Strict Liability For Defective Products, ¶ 2:1329 et seq. (The Rutter Group)

California Product Liability Actions, Ch. 2, Liability for Defective Products, § 2.13[4] (Matthew Bender)

40 California Forms of Pleading and Practice, Ch. 460, Products Liability, § 460.183 (Matthew Bender)

19 California Points and Authorities, Ch. 190, Products Liability, § 190.201 (Matthew Bender)