Supreme Court Rules EPA Approval Bars State Lawsuits Over Roundup Labels

Why it matters locally: This Supreme Court ruling may impact Delaware residents and agricultural businesses who have used glyphosate-based products and are considering legal action regarding potential health effects, as it limits the avenues for state-level lawsuits concerning Roundup's labeling.

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The Supreme Court ruled 7-2 on Thursday that federal pesticide law bars state lawsuits seeking to hold Monsanto liable for inadequate cancer warnings on Roundup, the herbicide containing glyphosate as its primary ingredient. Justice Brett Kavanaugh wrote for the majority in *Monsanto Company v. Durnell* that the Federal Insecticide, Fungicide, and Rodenticide Act preempts state failure-to-warn claims. The law grants the EPA exclusive authority over pesticide labeling and includes a uniformity requirement preventing states from imposing labeling requirements that differ from federal standards. The case originated when John Durnell sued Monsanto over Roundup's label, arguing the company failed to warn of cancer risks. Monsanto countered that the EPA, which oversees pesticide regulation, had not required a cancer warning, making state-level claims preempted by federal law. Kavanaugh explained the EPA undertakes "extensive review" of pesticides and their proposed labels before registration, determining "that the proposed label includes all warnings necessary and adequate to protect human health and the environment." Once approved, he wrote, manufacturers must use the EPA-authorized label until the agency approves changes or orders modifications. The EPA first reviewed glyphosate-based pesticides in 1974 and has "repeatedly concluded that glyphosate is not likely to cause cancer," according to Kavanaugh. This determination means "as a matter of federal law, Monsanto legally must use a label without a cancer warning unless and until EPA approves or requires a change." Kavanaugh rejected arguments that state claims protect public health or account for new research. The EPA "keeps abreast of new safety developments," he wrote, and third parties can "bring new information to EPA's attention" without using state lawsuits to "impose labeling requirements" the agency deemed unnecessary. The debate over glyphosate's safety intensified in 2015 when the International Agency for Research on Cancer, part of the World Health Organization, classified glyphosate as "probably carcinogenic to humans." That classification prompted tens of thousands of lawsuits against Monsanto. The company has paid billions in damages and settlements while asserting its legal position that state claims were preempted. Justice Ketanji Brown Jackson dissented, joined by Justice Neil Gorsuch. She argued the majority misread federal law. FIFRA limits state authority over pesticide labels but does not eliminate it, Jackson contended. States retain power to impose requirements equivalent to federal standards, and a cancer warning requirement qualifies because it stems from the shared goal of preventing misbranding. Jackson wrote that the EPA's approval of a label "cannot conclusively establish that the pesticide is not misbranded" under FIFRA's ongoing prohibition on misbranding. "The majority reads into FIFRA a labeling requirement that does not exist," she wrote, "and it reads out of FIFRA the statute's ongoing prohibition on misbranding." Justice Clarence Thomas wrote separately to support the majority but raised constitutional concerns about FIFRA itself, questioning whether it exceeds Congress's authority under the Commerce Clause and whether it improperly delegates legislative power to the EPA.