Bayer seeks Supreme Court review that could curb Roundup cancer lawsuits

Bayer is asking the U.S. Supreme Court to weigh whether federal pesticide law shields the company from thousands of lawsuits alleging that its Roundup weedkiller causes cancer, a move that could sharply limit one of the largest waves of product-liability litigation in U.S. history.

The dispute, first reported in detail by The New York Times, centers on whether the Environmental Protection Agency’s approval of glyphosate — Roundup’s active ingredient — pre-empts state laws that require manufacturers to warn consumers about cancer risks. Bayer argues that because the EPA does not classify glyphosate as a carcinogen and has repeatedly approved Roundup’s labeling without a cancer warning, it cannot legally add one, leaving state-level claims barred by federal law.

The case, Monsanto Co. v. Durnell, stems from a lawsuit filed by a Missouri gardener who developed non-Hodgkin lymphoma after years of Roundup use. Bayer, which acquired Monsanto in 2018, says lower courts are split on whether federal pesticide rules override state failure-to-warn claims, creating uncertainty that only the Supreme Court can resolve.

The Trump administration has sided with Bayer, reversing a position taken under President Joe Biden. That stance has angered an unusual coalition of Democrats, environmental groups and Republican-aligned “Make America Healthy Again” activists, who argue that a ruling for Bayer would amount to corporate immunity at the expense of public health.

Bayer has already paid more than $10 billion to settle roughly 100,000 Roundup claims and still faces thousands more. Farm groups backing the company say glyphosate is critical to U.S. agriculture, with the American Farm Bureau Federation estimating it is used on about 300 million acres of crops including soybeans, cotton and sugar beets. Without it, the group warns, yields would fall sharply.

Scientific and regulatory assessments remain divided. In 2015, the World Health Organization’s International Agency for Research on Cancer classified glyphosate as “probably carcinogenic,” citing evidence from animal studies and limited human data. The EPA, by contrast, has repeatedly found no cancer risk when the herbicide is used as directed. California and a handful of other states have sought stricter controls, challenging federal labeling standards.

The Supreme Court is scheduled to consider whether to hear the case at a private conference, with a decision on whether to take it up possible in the coming days. If the justices agree to hear the appeal and ultimately side with Bayer, many pending Roundup cases could be dismissed, reshaping liability risks not only for pesticide makers but for regulated industries more broadly.

The timing is sensitive. A scientific journal last month retracted a widely cited paper that had concluded glyphosate was safe, citing internal Monsanto emails that suggested company involvement in the research. The federal government is also required to re-examine glyphosate’s safety by 2026.

Legal analysts say the outcome could have far-reaching implications for the U.S. tort system, testing whether regulatory approval alone is enough to insulate companies from claims that products approved under federal standards still pose undisclosed risks.