The Standard for Proving Product Defect Under California Law

by John Chapman

A significant portion of fentanyl patch cases end up in California for at least two reasons:

  1. several manufacturers of fentanyl patches are located there; and
  2. the state is the most populated in the nation.

In our experience, California courts tend to apply California law, even if the person who died from a defective fentanyl patch was living (and ultimately died) in another state.  As a result, many fentanyl patch cases are resolved by California courts applying California law.

To prevail on a product liability suit in California, a plaintiff needs to prove that the relevant product was defective.  There are generally two types of evidence that a plaintiff can offer to show defect; direct evidence and circumstantial evidence.  Direct evidence is, as its name suggests, evidence that directly establishes a factual conclusion without requiring any sort of inference.  To illustrate in the context of fentanyl patch litigation, direct evidence of product defect would be if the patch that was on the victim at the time of his or her death was inspected and discovered to contain a breach in the seal through which fentanyl gel leaked.  In most fentanyl patch cases, direct evidence of defect is unavailable.  This is because the fentanyl patch the victim was wearing at the time of his or her death is usually disposed of by either medical personnel or the medical examiner who conducted the autopsy on the victim’s body.

Fortunately, California, like most other jurisdictions, does not require direct evidence of product defect and instead allows a plaintiff to prove product defect through circumstantial evidence.    See Soule v. Gen. Motors Corp., 8 Cal. 4th 548, 562 (Cal. 1994).   Circumstantial evidence is generally defined as evidence in which an inference is required to connect to an ultimate factual conclusion.  Examples of circumstantial evidence of defect in fentanyl patch cases include, among other things, the following:  (1) evidence that the fentanyl patch malfunctioned, that is, it did not function as intended; (2) evidence of the same accidents in similar fentanyl patches; (3) evidence eliminating other causes of death; (4) evidence that the death occurred a short time after the sale of the relevant fentanyl patch; and (5) expert testimony as to possible causes as to why the fentanyl patch failed to perform as intended.  See Barker v. Lull Eng. Co., 20 Cal. 3d 413, 429 (Cal. 1978); Hinckley v. LaMesa R.V. Center, 158 Cal. App. 3d 630, 642 (Cal. Ct. App. 4th Dist. 1984); accord Notmeyer v. Stryker Corp., 502 F. Supp. 2d 1051, 1059-60 (N.D. Cal. 2007); see also Gherna v. Ford Motor Co., 246 Cal. App. 2d 639, 650 (Cal. Ct. App. 1st Dist. 1966) Vandermark v. Ford Motor Co., 61 Cal. 2d 256, 260 (Cal. 1964). Gen. Motors Corp., 8 Cal. 4th 548, 562 (Cal. 1994) (citing Barker, 20 Cal. 3d at 430).  It should be emphasized that California does not require a plaintiff to come forward with  all of these categories of evidence to show product defect.  In subsequent entries, I will discuss these categories of evidence in more detail.