Product Liability Defense: Subsequent Alteration or Modification of Product
There are multiple defenses available in North Carolina for product liability claims. One that defendants can consider involves instances of subsequent alteration or modification of the allegedly defective product by a party other than the manufacturer. However, there are some important nuances to keep in mind related to this defense.
First, this defense is not available if the subsequent modification or alteration was: (1) in accordance with the manufacturer’s or seller’s instructions or specifications, or (2) made with the express consent of the manufacturer or seller.
Additionally, the statutory definition of “alteration” or “modification” is very specific. It includes “changes in design, formula, function, or use of the product from that originally designed, tested, or intended by the manufacturer.” It also includes a failure to observe routine care and maintenance, but does not include ordinary wear and tear.
The second critical condition to this defense is that a plaintiff’s subsequent alteration or modification must have been the proximate cause of the injury. The test set forth by the North Carolina courts for use of this defense is whether a person of ordinary prudence could have reasonably foreseen some injury as a result of the unintended use of the product.
Finally, in Stark ex rel. Jacobsen v. Ford Motor Co., a decision by the Supreme Court of North Carolina, it held that a person who modified or altered the product did not have to be a party to the product liability litigation in order to allow the manufacturer or seller to assert this defense. If the product was altered by anyone other than the manufacturer or seller, this defense is available so long as the remaining requirements are met.
This is one of the most common and available defenses to a product liability claim for a manufacturer given their initial position in the chain of custody. For suppliers, it is also available although it will depend upon the type of product involved. Overall, the analysis of this defense should be done at the outset of a claim or lawsuit by the defense to ensure the chance of success in its use as early as possible in the litigation process.
 N.C. Gen. Stat. § 99B-3(a).
 N.C. Gen. Stat. § 99B-3(b).
 Hastings v. Seegars Fence Co., 128 N.C. App. 166 (1997).
 Stark ex rel. Jacobsen v. Ford Motor Co., 365 N.C. 469 (2012).