California courts have forged a shield for product manufacturers faced with liability stemming from the foreseeable but unintended use of their product in conjunction with another manufacturer’s product. Consistent with a recent decision by the California Supreme Court, a California appellate court concluded that a manufacturer is generally not liable in strict liability or negligence for harm caused by another manufacturer’s product, despite the fact that the two products are compatible to be used together. This decision prevents plaintiffs from inflating their claims by suing the manufacturers of products used in conjunction with an injury causing product.

In Sanchez v. Hitachi Koki Co., Ltd., 217 Cal. App. 4th 948 (Cal. Ct. App. 2013), Plaintiff cut his hand while attempting to cut a tire using a Hitachi grinder in conjunction with a Razor Back saw blade. Plaintiff brought strict liability and negligence claims against Hitachi. Hitachi moved for summary judgment, arguing that it had no duty to warn Plaintiff to not use a saw blade with the grinder or to provide a safety mechanism for the use of a saw blade because the saw blade was manufactured by a third party. Hitachi further argued that the safety instructions for the grinder expressly warned that saw blades should never be used with the grinder. The trial court granted Hitachi’s motion for summary judgment, and Plaintiff appealed.

The appellate court affirmed the judgment, holding that “mere compatibility” with another manufacturer’s product does not render a product defective. The appellate court relied on the California Supreme Court’s recognition that “California law does not impose a duty to warn about dangers arising entirely from another manufacturer’s product, even if it is foreseeable that the products will be used together.” The appellate court reasoned that requiring a manufacturer to investigate and warn of all potential risks for all other products that might foreseeably be used with the manufacturer’s product “would impose an excessive and unrealistic burden on manufacturers.” The appellate court identified two narrow exceptions to this general rule: (1) when the defendant manufacturer’s own product contributed substantially to the harm; and (2) when the defendant manufacturer participated substantially in creating a harmful combined use of the products.

The Sanchez opinion illustrates the California judiciary’s intent to protect manufacturers from liability based solely on their product’s foreseeable but unintended compatibility with another manufacturer’s injury causing product. By carefully crafting product warnings to encompass unintended uses with other manufacturers’ products, a manufacturer can minimize its potential exposure to liability in California.

Sanchez v. Hitachi Koki Co., Ltd., 217 Cal. App. 4th 948 (Cal. Ct. App. 2013)

For additional information, please contact Joe Guffey or Joe Orlet.