SCOTUS Reinforces FIFRA Preemption In Significant Products Liability Decision

On June 25, 2026, the United States Supreme Court issued its decision in Monsanto Company v. Durnell, 609 U.S. ___ (2026), holding in a 7–2 opinion that the Federal Insecticide, Fungicide, and Rodenticide Act (“FIFRA”) expressly preempts certain state-law failure-to-warn claims. Specifically, the Court held that a state-law claim is preempted where it would require a manufacturer to include labeling that is “in addition to or different from” labeling approved by the Environmental Protection Agency.

The case arises from EPA’s longstanding position that glyphosate—the active ingredient in Roundup—is not likely to cause cancer and therefore does not require a cancer warning on product labeling. Under FIFRA’s comprehensive regulatory scheme, pesticide labels must be submitted to and approved by EPA, and manufacturers are required to use those approved labels unless and until EPA approves a change. FIFRA also includes an express preemption provision, titled “Uniformity,” that prohibits states from imposing labeling requirements “in addition to or different from those required under” the statute.

The plaintiff, a Missouri resident, alleged that long-term use of Roundup caused him to develop non-Hodgkin’s lymphoma and asserted a state-law failure-to-warn claim based on the absence of a cancer warning. A jury awarded damages on that theory, and the Missouri Court of Appeals affirmed. The Supreme Court granted certiorari to resolve a broader conflict over the scope of FIFRA preemption.

Reversing the judgment below, the Court held that the plaintiff’s claim was preempted because it would effectively require Monsanto to add a cancer warning that EPA has not required. In the Court’s view, federal law obligates manufacturers to use EPA-approved labeling, and state-law duties that mandate additional or different warnings fall squarely within FIFRA’s preemption clause.

The dissent, led by Justice Jackson, advanced a narrower view of preemption. It focused on FIFRA’s misbranding provisions, arguing that state-law duties could coexist with federal law where they enforce, rather than contradict, FIFRA’s requirement that labeling be adequate to protect health and the environment. The majority rejected that framing, concluding that the state-law duty at issue would impose a labeling requirement inconsistent with EPA’s determination that a cancer warning is not necessary.

The decision provides meaningful guidance for manufacturers operating within federally regulated labeling regimes. While the Court did not eliminate all state-law claims, it makes clear that failure-to-warn theories premised on labeling different from EPA-approved language face significant preemption hurdles. For companies subject to FIFRA—and potentially analogous regulatory schemes—the ruling reinforces the importance of federal label approval as the governing standard and offers a stronger basis to challenge state-law claims that would require divergent warnings.

What this means for manufacturers

Stronger preemption defense for labeling-based claims. Where a product’s label is reviewed and approved by a federal regulator, failure-to-warn claims premised on adding different or additional warnings may face significant preemption challenges.

EPA-approved labeling carries increased litigation significance. The decision underscores that compliance with EPA labeling requirements is not just regulatory—it can be outcome-determinative in litigation involving warning theories.

Focus on how claims are framed. Plaintiffs may attempt to recast warning claims as broader design, testing, or marketing theories to avoid preemption. Early case strategy should assess how claims are pleaded and whether they are, in substance, labeling challenges.

Possible implications beyond FIFRA. While the decision is grounded in FIFRA, it may inform preemption arguments in other federally regulated industries where agencies exercise comparable control over labeling or disclosures.