Monsanto Asks Supreme Courtroom to Preempt State Roundup Most cancers Claims

Monsanto has filed its opening brief at the U.S. Supreme Court, asking the justices to wipe out a Missouri verdict that held the company liable for failing to warn that Roundup causes cancer.

The case lands in a political moment favorable to Bayer AG, Monsanto’s German parent company. Last Wednesday, President Donald Trump signed an executive order framing the glyphosate supply as a national-defense issue and directing federal prioritization of domestic production. It also contains language that effectively protects producers from regulatory and legal pressure by emphasizing that government action should not “place the corporate viability” of domestic producers “at risk.” The brief explicitly quotes that order, repeating its demonstrably false claim that agricultural productivity would suffer without glyphosate.

Last December, the Trump Justice Department entered the case as amicus curiae – “friend of the court” – urging the SCOTUS to adopt Monsanto’s position.

Roundup’s main active ingredient, glyphosate, has already been linked to cancer in multiple legal disputes and peer-reviewed studies. Juries have awarded billions in damages against Monsanto over Roundup-related claims, and about 61,000 lawsuits remain active.

Additionally, last Tuesday, Bayer announced a proposed $7.25 billion class settlement intended to resolve current and future Roundup claims, a move the company described as part of a broader strategy to contain ongoing litigation.

The Case

The core legal question of the case Monsanto Company v. Durnell is whether FIFRA, the Federal Insecticide, Fungicide, and Rodenticide Act, blocks state failure-to-warn verdicts when the Environmental Protection Agency (EPA) — one of many unconstitutional federal agencies long captured by corporate lobbyists — has repeatedly approved labels without a cancer warning.

Argument is set for April 27.

Federal Primacy

Monsanto’s brief opens with a blunt thesis about federal primacy. It argues that EPA has reviewed glyphosate for decades and reached the same conclusion “again and again”:

EPA has exhaustively studied glyphosate … and concluded again and again in registering countless versions of Monsanto’s Roundup products that glyphosate does not cause cancer.

That conclusion is the spine of the preemption argument. Monsanto says EPA not only declined to require a cancer warning, but that a warning “stating otherwise is neither required nor permitted under FIFRA.”

The company then contrasts that federal judgment with what happened in Missouri:

A Missouri jury hearing a state-law failure-to-warn claim had other ideas.

The jury, Monsanto says, demanded “precisely the kind of cancer warning on Roundup’s label that EPA considered and rejected.”

In the case in question, Anderson v. Monsanto Co., the jury sided with a Missouri man who alleged that prolonged occupational exposure to Roundup caused his non-Hodgkin’s lymphoma. It found Monsanto liable for negligence, defective design, and failure to add a warning label about the product’s cancer risks. The decision cited internal documents and scientific studies suggesting that Monsanto was aware of potential carcinogenic risks associated with glyphosate-based formulations but failed to communicate those risks to users.

“The Label Is the Law”

The brief repeats a phrase that has become almost a slogan in pesticide regulation:

Once EPA approves a label, the “label is the law!”

That matters because Monsanto’s second preemption theory is impossibility. The company argues that even if a state jury wants a cancer warning, federal law bars Monsanto from unilaterally adding it. In the brief’s words:

Manufacturers cannot distribute pesticides with labels that differ substantially from the label approved by EPA.

So the state verdict, Monsanto argues, orders an outcome that federal law blocks. It calls this a basic impossibility conflict:

Simultaneous compliance with federal and state law would be impossible.

If EPA approves a label without a cancer warning, and if EPA views such a warning as false or misleading, then state tort law is not just different. It is a trap, argues the company.

Uniformity, the “Crazy Quilt,” and “Lay Juries”

Monsanto’s brief argues that pesticide labeling cannot be governed by 50 different jury systems without wrecking national uniformity and market availability:

To ensure ‘[u]niformity’ in pesticide labeling, FIFRA expressly preempts any state-law labeling requirement that is ‘in addition to or different from those required under’ the statute.

It then invokes the Supreme Court’s own language about the “crazy-quilt” of conflicting state rules, saying that is exactly what Congress enacted the uniformity clause to stop.

Then the broadside, repeating:

Once EPA makes that judgment, the label is the law. It cannot be second-guessed by lay juries applying the law of 50 states.

And the brief points to a claimed market consequence that Bayer has already made real:

Cascading tort liability has forced Monsanto to remove glyphosate from the residential consumer market while threatening its availability for farmers.

That is the outcome Trump’s executive order tries to prevent. As quoted in the brief:

“reduction or the cessation of domestic production” of “glyphosate-based herbicides would … hav[e] a debilitating impact on domestic agricultural capabilities.”

Significance of the Case

If Monsanto wins on preemption, the impact could be sweeping. A ruling that FIFRA blocks label-based failure-to-warn claims whenever the EPA has approved a pesticide label would effectively elevate a federal agency’s risk-determination above the authority of state courts and juries. It would hand Bayer a powerful mechanism to knock out large categories of Roundup cases by arguing that once Washington has spoken, states are barred from reaching their own conclusions, even through traditional tort law.

If Monsanto loses, states would retain the authority to protect their own citizens through product liability law, including through so-called lay juries tasked with weighing evidence in open court. It would preserve the ability of state courts to impose liability where they find harm, even when federal regulators have approved a product’s label. In that sense, the case tests whether federal pesticide regulation sets a floor for safety, or a ceiling that forecloses any further accountability at the state level.

Bayer in D.C.

Bayer’s legal push before the Supreme Court coincides with a widening network of influence inside the Beltway. As reported by the nonprofit U.S. Right to Know, federal disclosures show the company spent $9.19 million lobbying Congress and the executive branch in 2025, retaining at least 13 outside firms and registering 45 lobbyists.

Those firms include Ballard Partners and Mercury Public Affairs, both staffed by senior figures tied to Trump’s campaigns or administration. Heading Ballard Partners is Brian Ballard, who reportedly raised more than $50 million for Trump’s 2024 campaign. He also served on his 2024 inaugural and transition finance committees. His firm previously employed both White House Chief of Staff Susie Wiles and Attorney General Pam Bondi.

The group also traced extensive Bayer ties inside the Department of Agriculture (USDA) and the EPA, placing former industry lobbyists and legal allies in roles that shape pesticide approvals and chemical regulation

The group reported that “over the past year, the administration … has delivered a string of victories to Bayer.” Besides the recent executive order, those include the DOJ’s aforementioned petition to the Supreme Court,

placing the weight of the executive branch on the side of a foreign company against thousands of Americans who say Bayer’s products caused their cancers.

And recently, the EPA reapproved dicamba, a Bayer herbicide twice blocked by federal courts.