Supreme Court to Weigh FIFRA Preemption in Roundup Cancer Warning Case
The Supreme Court has agreed to hear Monsanto’s appeal of a $1.2 million jury verdict in favor of a plaintiff who claimed Roundup weedkiller caused his cancer, focusing on whether the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) preempts state failure-to-warn claims when EPA has not required the warning.
At the core of the dispute is FIFRA section 24(b), 7 U.S.C. 136v(b), which forbids states from imposing labeling requirements “in addition to or different from those required under” FIFRA. Citing the Supreme Court’s 2005 decision in Bates v. Dow Agrisciences LLC, the Ninth and Eleventh Circuits have held that this language does not preempt state-law claims if the elements of the claim “parallel” FIFRA’s prohibition on misbranding.
However, more recently, in 2024, the Third Circuit created what many view as a circuit split, ruling that those courts erred by applying the “parallel requirements” test from Bates too generally. According to the Third Circuit, EPA regulations implementing FIFRA prohibit manufacturers from adding precautionary statements to product labels without EPA approval, making such labels preempted.
Monsanto’s petition for certiorari, filed April 4, 2025, asks the Court to adopt the Third Circuit’s analysis. “Because the jury verdict in this case requires Monsanto to include a cancer warning that EPA’s regulations did not require—and in fact affirmatively forbade it from adding—FIFRA preempts Respondent’s claim,” the petition argues.
Respondent John Durnell argues that the circuit split is both “irrelevant” and “illusory.” In his June 9, 2025, brief, he argues that the jury verdict did not hinge on the labeling claims because Monsanto also advertised Roundup as safe in television advertisements. He further maintains that there is no actual circuit split.
According to Durnell, there are two ways to update pesticide product labeling: by notification to EPA or by applying for amended registration. Due to a “unique quirk” in the Third Circuit case, the court explicitly limited its analysis to the first option and “express[ed] no opinion” on whether FIFRA required Monsanto to pursue the latter, the brief states.
The Supreme Court’s decision is likely to have massive implications for numerous suits alleging that glyphosate, the active ingredient in Roundup, is carcinogenic. EPA has repeatedly determined that glyphosate does not cause cancer, but the International Agency for Research on Cancer (IARC) has classified glyphosate as a probable human carcinogen.
The case is Monsanto Co. v. Durnell, No. 24-1068 (U.S.), petition for writ of certiorari granted January 16, 2026.
