LINCOLN, Neb. (DTN) -- Justices on the U.S. Supreme Court seemed to struggle Monday with a question that could determine whether product liability cases like the cancer lawsuits filed against Bayer's Roundup herbicide will be allowed to continue.

At issue is whether a U.S. Environmental Protection Agency stamp of approval on a pesticide label is enough to shield Bayer from thousands of state warning label lawsuits against glyphosate-based Roundup, or if individual juries still get to decide whether the chemical causes non-Hodgkin's lymphoma.

Justices hearing oral arguments in the case, Monsanto v Durnell, spent nearly 90 minutes wrestling with a fundamental conflict in federal law.

The Federal Insecticide, Fungicide and Rodenticide Act's express preemption clause says states cannot impose labeling requirements that go beyond what federal law demands.

Another provision of FIFRA says EPA's findings at registration are not a binding legal command. Which provision controls could determine the outcome of thousands of Roundup cancer suits.

Paul Clement, a former U.S. solicitor general representing Bayer in the case, reiterated before the court that federal law preempts state failure-to-warn claims.

"Here, a Missouri jury imposed a cancer warning requirement that the EPA does not require," Clement told the court.

"That additional requirement is preempted."

Bayer argued that when EPA registers a pesticide and approves a label, it creates a binding federal requirement.

Clement used the word "under" when describing how FIFRA preempts state warning label laws.

"Nonetheless, he (defendant attorney) insists that unless Congress expressly directs the agency to bind the judiciary, then the requirements that are imposed on a particular pesticide in the registration process and backed by criminal penalties are not federal requirements," Clement said.

"That defies common sense, the statutory text, and this court's precedents. The word 'under' is important here because that word textually captures the various requirements that are imposed at a device-specific level or a herbicide-specific level in the context of the registration process."

NO LABEL WARNING WITHOUT EPA

Bayer also argued that a pesticide registrant cannot add a cancer warning without EPA approval, essentially making it impossible to comply with federal and state laws simultaneously.

"Thus, Missouri law here requires something that not only is not required by federal law, but that federal law doesn't even allow," Clement said.

Ashley Conrad Keller, the attorney for the respondent in the case, argued that FIFRA's registration process does not create a binding label requirement -- pointing to a prima facie evidence clause that limits the preemptive force of registration.

Keller pointed to the 2005 Supreme Court case Bates v Dow Agrosciences to support her argument. In that case, the court ruled 7-2 that FIFRA does not preempt state-law damage claims against chemical manufacturers.

"You unanimously held in Bates that a pesticide can be registered and nevertheless misbranded, even if it uses the label that EPA approved at registration," Keller told the court.

"Yet Monsanto now asks you for the opposite holding, that Roundup cannot be misbranded as a matter of law, because EPA found for the first time 50 years ago, as a matter of fact, that it is safe."

Keller said throughout the case, Bayer "still hasn't pointed to one word in FIFRA's text" that says EPA's factual findings at registration create a requirement for labeling.

"There is nothing in, by, under, or next to FIFRA that makes the registration decisions that EPA makes binding labeling requirements with preemptive force," she said.

WHERE JUSTICES LEAN

Typically, it's difficult to determine which way the court leans in cases based on the oral arguments. The trio of justices, including Ketanji Brown Jackson, Sonia Sotomayor and Elena Kagan, pressed Bayer's attorney Clements the hardest.

Justice Ketanji Brown Jackson pressed Clement repeatedly on the question of whether a registered product can become misbranded between registrations.

"What I'm asking is, could we have a world in which a product that has been registered, the label is consistent with what the agency has said is appropriate at the time of registration, but let's say a new research study comes out that casts doubt on the safety of this product?" Jackson asked of Clement.

"My understanding is that, under Bates, you could have a product that is registered that becomes misbranded. That's my only -- am I right about that?"

When Clement responded "No," Jackson flatly responded: "I disagree with that."

Sotomayor zeroed in on what she said was the core of Bayer's argument.

"That's really what it boils down to, then, for you," she said to Clement.

"It's not that you can, in fact, have misbranded but registered items and EPA can seek remedies against you. You're just saying nobody else can do the same, even if it's a parallel proceeding, because you have to go through processes to amend the label. So, is it kind of the, this really boils down to the impossibility argument then, doesn't it?"

Kagan then presented an alternative framework that pesticide registration sets requirements at some point, then state laws can enforce the no-misbranding obligation during the in-between years on registrations.

"I worry a little bit about the way in which you are describing this and its seeming inconsistency with what we said in Bates," Kagan said.

"I think in Bates we said that FIFRA contemplates that pesticide labels will evolve over time. And we said, quote, 'Tort suits can serve as a catalyst in this process.'"

On the flipside, Justices Brett Kavanaugh, Clarence Thomas and Samuel Alito did not press Bayer during the oral arguments, while Justice Amy Coney Barrett and Chief Justice John Roberts didn't seem to indicate that they were leaning either way. Justice Neil Gorsuch didn't ask any substantive questions during the hearing.

RESPONDENT PRESSED

During Keller's oral argument, Kavanaugh pressed her on how uniformity in labeling laws can be achieved if FIFRA is not the law of the land.

Kavanaugh asked whether a label that subjects a manufacturer to liability in Missouri but not in other states is consistent with the statute's explicit uniformity title.

"Is the label illegal in one state and legal in another state? That's uniformity," he said.

Kavanaugh also confronted Keller on whether unilaterally changing the label would violate federal law.

When she said "No," Kavanaugh shot back: "Is the Solicitor General wrong about that?" implying the U.S. government's position goes against the respondent.

Todd Neeley can be reached at todd.neeley@dtn.com

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