SCOTUS Holds FIFRA Expressly Preempts State Law Failure To Warn Claims

On June 25, 2026, the U.S. Supreme Court issued its decision in Monsanto Co. v. Durnell, resolving a dispute over the scope of federal preemption under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), 7 U.S.C. Section 136 et seq. The case presented the question of whether FIFRA preempts a label-based state-law failure-to-warn claim where the U.S. Environmental Protection Agency (EPA) has approved a label that does not require the warning at issue. In a 7-2 decision, the Court held that FIFRA expressly preempts plaintiff’s state-law failure-to-warn claim because it would require Monsanto to add a cancer warning to Roundup’s label.

The decision resolves a circuit split, holding that federal pesticide labels preempt divergent or additional state warning or labeling requirements. It may limit state-law claims against pesticide registrants based on theories of inadequate warning and may provide guidance for pesticide registrants, manufacturers of federally regulated