The Supreme Court’s Roundup Decision: What Changed and What Comes Next
Editor’s Note: This blog is written by ICL’s 2026 Andrus Scholar Meghan Calley.
On June 25, 2026, the U.S. Supreme Court ruled 7–2 in Monsanto v. Durnell in favor of Monsanto, making it significantly harder to hold pesticide manufacturers accountable over health concerns linked to products like the company’s herbicide, Roundup. This decision reshapes pesticide accountability, especially in agricultural states like Idaho, where farming plays a central role in our economy. Given Idaho’s agricultural heritage, many people live and work near areas where pesticide exposure is common, raising important questions about how legal protections can safeguard public health.
How We Got Here
John Durnell developed a type of blood cancer called non-Hodgkin lymphoma after using Monsanto’s glyphosate-based herbicide, Roundup, for about 20 years while working at a local park in Missouri. In 2019, he sued Monsanto—now owned by Bayer following its 2018 acquisition—arguing the company failed to warn users about the product’s potential cancer risks. In 2023, a Missouri jury agreed, awarding Durnell $1.25 million. The verdict was later upheld by the Missouri Court of Appeals. Monsanto appealed to the U.S. Supreme Court in April 2025, shifting the case from questions about product warnings to the broader role of federal authority.
Federal Preemption and FIFRA
Preemption—the principle that higher levels of government can override laws or regulations enacted by a lower level authority—was a focal point in the case. In this case, the question was whether federal law can override state law. Monsanto argued that the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) preempted Durnell’s state law failure-to-warn claim.
Under FIFRA, pesticides must be registered with the Environmental Protection Agency (EPA) before sale and distribution. Labels must be reviewed and approved by the EPA, and manufacturers cannot add or change those labels without federal approval.
Durnell's attorneys pointed to research linking glyphosate to cancer, including a 2015 study from the International Agency for Research on Cancer (IARC), part of the World Health Organization, which classified glyphosate as "probably carcinogenic to humans." Bayer has already paid roughly $11 billion to settle claims related to Roundup and alleged health harms, underscoring the widespread concern surrounding the product. While the EPA continues to maintain that glyphosate is unlikely to cause cancer when used according to label directions, Durnell argued that manufacturers still have a responsibility to warn users when credible scientific research and evidence raises serious health concerns, such as cancer.
Justices’ Decision
Justice Brett Kavanaugh, writing for the majority, concluded that because the EPA reviews and approves pesticide labels, state juries cannot hold manufacturers liable for failing to include warnings the EPA didn’t require.
Justice Ketanji Brown Jackson, joined by Justice Neil Gorsuch, dissented. Jackson wrote, “the Court misunderstands FIFRA’s requirements, misinterprets the scope of FIFRA’s preemption, and ultimately leaves Durnell without a remedy for the significant harms he has suffered.” This stance emphasizes that federal EPA approval should serve as a regulatory baseline—not as immunity from accountability for pesticide manufacturers.
Why It Matters
Supporters of the ruling argue that it creates regulatory consistency and reduces confusion and overlitigation. If a product follows the label approved by the EPA, they contend, companies shouldn’t face liability based on different state standards.
Critics, however, argue that this ruling doesn’t account for the serious health concerns and growing scientific evidence raising concerns about glyphosate exposure. A study from Boise State University tracked glyphosate levels in pregnant people and found significantly higher exposure among those living near farmland during spray season. Another study from UC Berkeley reported higher levels of glyphosate in childhood and adolescence were associated with an increased risk of liver inflammation and metabolic disorders. Even when pesticides are applied according to regulations, pesticide drift and environmental exposure remain serious concerns for nearby communities and waterways.
As a result of this ruling, people who developed illnesses they believe are linked to pesticides exposure may have fewer legal options to hold manufacturers accountable if product labels do not include warnings beyond those approved by the EPA.
Next Steps
While the Supreme Court’s decision may narrow the path to holding pesticide manufacturers liable, efforts to strengthen public protections are already underway. Beyond Pesticides has launched a national mobilization campaign with educational resources supporting efforts to require manufacturers to require manufacturers to include clearer warning labels about potential long-term health effects, including cancer.
In Congress, Representatives Chellie Pingree (D-ME) and Thomas Massie (R-KY) introduced People Over Poison Act (H.R. 9528), a bipartisan bill that would amend FIFRA to clarify that federal pesticide law does not preempt state failure-to-warn claims. If enacted, the bill would restore the ability of people harmed by pesticide exposure to hold manufacturers accountable in state courts.
At the same time, ICL constituents contacted decision-makers over 1,600 times by email and phone in support of stronger pesticide protections, demonstrating growing public concern about the health and environmental impacts of pesticide exposure.
Join other Idahoans in speaking up for public health. Tell your elected representatives in Congress to support the People Over Poison Act (H.R. 9528) to help restore pesticide manufacturer accountability and better protect our Idaho communities.