WLF Urges Federal Court to Enforce FIFRA Preemption Against Artful Pleading in Roundup Cases

“Allowing plaintiffs to evade preemption through clever labels would destroy the uniformity Congress demanded under FIFRA.”
—Cory Andrews, WLF General Counsel & Vice President of Litigation

Click here for WLF’s brief.

WASHINGTON, DC—On October 30 Washington Legal Foundation (WLF) urged a federal judge overseeing Multidistrict Litigation in the U.S. District Court for the Northern District of California to hold that plaintiffs’ claims are preempted by the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). Joining the U.S. Chamber of Commerce on an amicus brief, WLF contends that plaintiffs cannot evade the Supreme Court’s recent decision in Monsanto v. Durnell by merely relabeling failure-to-warn claims as design-defect or negligence theories.

The case stems from lawsuits alleging that exposure to Monsanto’s Roundup herbicide caused non-Hodgkin lymphoma. In June 2026, the Supreme Court held in Durnell that FIFRA expressly preempts state-law failure-to-warn claims seeking cancer warnings beyond those approved by the EPA. Judge Vince Chhabria then invited MDL amicus briefing on whether that holding also preempts negligence, design-defect, and warranty claims under the laws of six states.

In its amicus brief, WLF argues that preemption turns on the substance of a claim, not the label plaintiffs affix to it. Any theory that would require a warning not on the EPA-approved label is preempted, regardless of how plaintiffs style the claim. Allowing artful pleading to defeat FIFRA would undermine nationwide uniformity, empower lay juries to override expert agency judgments, and threaten identical preemption provisions in other federal statutes.