On March 6, 2026, the NAM filed an amicus brief in the U.S. Supreme Court urging the Court to grant cert and reaffirm that the Federal Rules of Evidence require trial courts to act as gatekeepers and exclude unreliable expert testimony. Union Carbide Corp., et al. v. Sommerville is a toxic tort case involving a class of plaintiffs who claim an increased risk of injury due to alleged ethylene oxide exposure from a West Virginia chemical plant. The district court properly excluded one of the plaintiffs’ experts due to unresolved questions about the bases for his testimony. Unfortunately, the 4th Circuit reversed. It joined the 1st Circuit in holding that questions about the bases of an expert’s testimony are not reasons to exclude the expert, only considerations that speak to his or her credibility. The defendant has now petitioned the Supreme Court to address this problematic ruling.
In support of the petition, our amicus brief argues that Rule 702 requires district courts to act as gatekeepers and exclude testimony that is not properly supported by science. This duty is designed to protect jurors from the undue influence of highly credentialed individuals testifying on complex, technical matters. All manufacturers have an interest in keeping the trial bar in check and preventing junk science from entering the courtroom.