The U.S. Supreme Court on Monday heard oral arguments in a case that could reshape how pesticide warning labels are regulated, taking up a dispute between Missouri resident John Durnell and agrochemical giant Monsanto over the popular Roundup weed killer.
Durnell sued Monsanto in 2019 after alleging he contracted non-Hodgkin's lymphoma from his 20-year exposure to glyphosate, the active ingredient in Roundup. A Missouri state jury awarded him more than $1 million in damages, finding Monsanto failed to properly warn users about cancer risks associated with the product.
The case centers on a fundamental question: Should federal pesticide registration law preempt state courts and juries from awarding damages based on their own determinations about warning labels?
What the Right Is Saying
Monsanto's legal team, including former Solicitor General Paul Clement, argued for a single, uniform national standard for pesticide labeling. They contend allowing individual state juries to override EPA-approved labels would create an unworkable patchwork of regulations that undermines agricultural productivity and consumer clarity.
"It's probably the most studied herbicide in the history of man and they've all reached the conclusion, based on more data and expert analysis they can do, that there isn't a risk here," Clement told the justices. "You shouldn't let a single Missouri jury second guess that judgment."
The Trump administration's solicitor general backed Monsanto's position, with Principal Deputy Solicitor General Sarah Harris arguing the EPA is the appropriate authority to determine warning labels. "Missouri thus requires adding cancer warnings but federal law requires EPA to approve new warnings and tasks EPA with deciding what label changes would mitigate any health risks," she said. "State law must give way."
Conservative legal scholars argue that uniform federal standards for agricultural products are essential for interstate commerce, preventing individual state juries from effectively dictating national product labeling policies.
What the Left Is Saying
Progressive legal advocates argue the Supreme Court should preserve the ability of state courts to hold corporations accountable when federal regulators move too slowly to protect public health.
Justice Ketanji Brown Jackson pressed Monsanto's attorneys during oral arguments about what happens when new scientific evidence emerges between EPA registration cycles. She noted there is a 15-year window before products must be re-registered, raising questions about how quickly the federal system can respond to emerging health concerns.
Durnell's attorney, Ashley Keller, wrote in court filings that Missouri law banning the sale of dangerous pesticides without adequate warnings is a traditional state police power matter. He argues juries should continue serving as fact-finders on whether companies provided sufficient risk disclosures.
Environmental and public health groups watching the case say states have historically played important roles in protecting residents from hazardous products, particularly when federal agencies face political pressures or resource constraints.
What the Numbers Show
Tens of thousands of lawsuits have been filed against Monsanto by individuals claiming exposure to Roundup caused their cancers. Durnell's case represents one of those pending claims.
Bayer acquired Monsanto in 2018 and has already paid billions in settlements across multiple cases. The company now sells Roundup containing glyphosate only to farmers and commercial businesses, having discontinued residential sales.
The EPA completed its most recent registration review of glyphosate in 2020, finding the herbicide is unlikely to be carcinogenic. However, international agencies have reached different conclusions about the chemical's health effects.
Missouri law requires warnings on products deemed dangerous without adequate disclosures. Durnell's jury found Monsanto liable under that standard, awarding him $1,025,000 in damages before post-trial motions.
The Bottom Line
The Supreme Court is expected to issue its ruling by June. How the justices resolve this preemption question will determine whether thousands of remaining Roundup cases can proceed through state courts or must be dismissed based on federal pesticide registration law.
Agricultural industry groups are closely watching, as a ruling in favor of broader state authority could affect labeling requirements for numerous products beyond pesticides. Consumer safety advocates argue the opposite outcome would strip states of traditional police powers to protect residents.
The justices will not decide whether glyphosate causes cancer. Instead, they must determine who has ultimate authority over warning labels once the EPA completes its registration review: federal regulators or state courts and juries. That distinction could reshape product liability litigation for years to come.