3M Shorn of ‘Intermediary’ Defense in Earplug Test Trial

3M Co. is unable to escape former service members’ claims in a bellwether trial over the company’s combat earplugs through a specialized legal defense that the U.S. military was a “sophisticated intermediary” with the responsibility to warn and instruct users, a federal court in Florida ruled.

The defense, typically used in cases involving industrial materials, isn’t available under Georgia and Kentucky law, which govern the three men’s claims against 3M and its subsidiary Aearo Technologies LLC, Judge M. Casey Rodgers said Tuesday for the U.S. District Court for the Northern District of Florida.

“Even assuming theoretically that Kentucky and Georgia ...