“State of the art” is a complete affirmative defense in products liability cases premised on a theory of “strict liability – failure to warn” in Missouri. This is codified in Missouri Revised Statute Section 537.764. This “state of the art” defense means that the dangerous nature of a product was not known, and could not reasonably be discovered, at the time the product was placed into the stream of commerce.

Often, disputes arise over the evidence associated with this defense. Parties frequently joust over what was known and could reasonably be discovered at the time a product was sold. Plaintiffs typically argue that evidence such as a notice of an adverse event with a product or a medical record purporting to link an adverse event to a product is sufficient. But Missouri law is not well-developed on this issue. Under the circumstances, manufacturers should argue that the dangerous nature of a product could not be known and could not reasonably be discovered absent a risk that has been identified in a peer-reviewed study performed by the relevant scientific community at the time of sale.