Bayer’s long-running attempt to halt the flood of litigation over its Roundup weedkiller met skepticism at the U.S. Supreme Court, where justices appeared split over whether federal pesticide law shields the company from state-level failure-to-warn lawsuits.
At the heart of the dispute is Bayer’s argument that federal regulation under the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA) overrides claims brought under state law alleging Roundup users were not warned that glyphosate could cause cancer. The company says allowing juries in different states to impose their own warning standards would fracture a national regulatory framework.
The case stems from a Missouri verdict awarding $1.25 million to John Durnell, who linked his diagnosis of non-Hodgkin lymphoma to decades of exposure to Roundup. Bayer is asking the nation’s highest court to overturn that ruling in a move that could shape the fate of thousands of similar claims.
Inside the courtroom, the argument quickly turned into a larger fight over who gets the final word on consumer safety warnings — federal regulators or state juries.
Bayer’s counsel urged the court to preserve uniform pesticide labeling nationwide, warning that allowing lawsuits like Durnell’s to stand could unleash massive liability and disrupt reliance on federally approved products used across American agriculture.
But some justices questioned whether state tort claims necessarily clash with federal law.
Justice Neil Gorsuch pushed on whether private lawsuits merely reinforce duties already embedded in federal law, rather than contradict them. Chief Justice John Roberts raised another tension: what happens when emerging safety concerns arise before regulators act?
That concern hovered over much of the hearing.
Several justices, including Brett Kavanaugh and Elena Kagan, appeared troubled by the prospect of fifty states effectively crafting their own cancer-warning requirements. Yet Roberts signaled discomfort with a system where states may be powerless to respond while federal agencies deliberate.
The Biden-era regulatory backdrop has long favored Bayer’s position, with the Environmental Protection Agency repeatedly maintaining glyphosate is not carcinogenic and approving Roundup labels without a cancer warning. That position forms the backbone of Bayer’s preemption defense.
Still, the litigation pressure is immense.
More than 100,000 claims have been filed linking Roundup to cancer, turning Monsanto — which Bayer acquired in its $63 billion takeover in 2018 — into one of the costliest legal inheritances in corporate history.
The company has already removed glyphosate from consumer versions of Roundup and recently unveiled a proposed $7.25 billion settlement aimed at resolving vast swaths of present and future claims. Yet significant exposure remains.
Durnell’s case symbolizes the stakes. Court filings say he spent roughly two decades spraying Roundup in neighborhood parks around St. Louis, often without protective gear, before developing an aggressive form of lymphoma. A jury believed that connection; Bayer wants the Supreme Court to say the lawsuit should never have proceeded.
The justices now face a ruling that could reverberate far beyond one herbicide.
It may decide not only whether Bayer can curb sprawling litigation, but also how far federal regulators can shield corporations from state court accountability.
A decision is expected by the end of June.
