The Supreme Court is deciding whether EPA-approved pesticide labels block state lawsuits over Roundup's alleged cancer risks — a ruling with major implications for consumer protection and food systems.
The Supreme Court is weighing a case that could reshape thousands of lawsuits over Roundup, the weedkiller made by Monsanto and now owned by Bayer.
At issue is whether federal pesticide labeling law blocks state-level failure-to-warn claims when the Environmental Protection Agency has approved a product label without requiring a cancer warning. As reported by Grist, the case centers on Monsanto Company v. Durnell, a dispute brought by Missouri resident John Durnell after years of Roundup use.
Durnell sued Monsanto in 2019, arguing that he developed non-Hodgkin lymphoma after regularly spraying Roundup around his neighborhood for roughly two decades. In 2023, a Missouri jury found Monsanto liable for failing to warn users about alleged cancer risks and awarded him $1.25 million in damages.
Monsanto has denied that Roundup caused Durnell's cancer and has appealed the verdict. The company's central argument is that the Federal Insecticide, Fungicide, and Rodenticide Act, known as FIFRA, preempts state-law claims that would effectively require a label warning the EPA itself has not required.
The Supreme Court's docket states the question directly: whether FIFRA preempts a label-based failure-to-warn claim where EPA has not required the warning. That makes the case much bigger than one Missouri verdict. A ruling for Monsanto could limit similar lawsuits across the country. A ruling for Durnell could preserve state tort claims as a way for plaintiffs to challenge pesticide warnings after products have cleared federal review.
Bayer has faced more than 100,000 Roundup-related claims since buying Monsanto in 2018. The company has set aside billions of dollars for settlements and continues to dispute claims that glyphosate, Roundup's active ingredient, causes cancer.
The science and regulatory record remain contested. The World Health Organization's International Agency for Research on Cancer classified glyphosate as "probably carcinogenic to humans" in 2015. The EPA, by contrast, has said glyphosate is not likely to be carcinogenic to humans when used according to the label. That gap between international hazard classification, federal label approval, and state-law liability is part of what makes the case so closely watched.
Glyphosate is also one of the most widely used herbicides in American agriculture. A 2021 EPA biological evaluation assessed risks from labeled uses of glyphosate to federally listed species and designated critical habitats. The agency said the evaluation was part of its Endangered Species Act review process for conventional pesticides.
The case lands at a moment when pesticide regulation is drawing new scrutiny from environmental groups, farmworker advocates, public-health campaigners, agricultural interests, and the Make America Healthy Again movement. Some groups argue that EPA-approved labels do not always give users enough information about long-term risks. Bayer and agricultural groups argue that allowing different state-law warning standards could create regulatory uncertainty for products already reviewed by the federal government.
Advocacy groups have tried to use the case to spotlight broader concerns about pesticide labeling. Analyses by the Center for Biological Diversity and the Center for Food Safety argued that the EPA has often failed to require cancer warnings on pesticide products even when agency assessments identified cancer concerns for certain active ingredients.
Those analyses are not the same thing as a Supreme Court finding, and they do not resolve the scientific debate over glyphosate. But they do help explain why environmental and consumer groups see the Durnell case as a test of whether state lawsuits can still pressure companies when federal labels are disputed.
For consumers, the immediate takeaway is not that the Supreme Court is deciding whether Roundup causes cancer. It is deciding who gets the final word on warning labels: the EPA, state courts, or some combination of both.
A decision is expected by the end of June. Whatever the outcome, the ruling could determine whether thousands of Roundup plaintiffs can continue pressing failure-to-warn claims, and how much power federal pesticide labels carry when new legal and scientific challenges emerge after a product is already on the market.
