Montana AG Joins Coalition Supporting Uniform Herbicide Labeling

Attorneys general argue federal rules should preempt state-level labeling requirements.

Published on Mar. 6, 2026

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Montana Attorney General Austin Knudsen joined a 15-state coalition in asking the Supreme Court to uphold uniform national labeling requirements for farming herbicides like glyphosate. The coalition argues that allowing individual states to impose their own labeling rules would disrupt supply chains, increase costs for farmers, and potentially limit access to proven safe and environmentally friendly weed control products.

Why it matters

This case highlights the ongoing tension between federal and state regulatory authority over agricultural products. Uniform national standards help ensure consistent access and pricing for farmers, while state-level rules can create a patchwork that disrupts supply and raises costs.

The details

The attorneys general filed an amicus brief in the case of Monsanto Company v. John Durnell, where a Missouri district court ruled that Monsanto must add a warning label to glyphosate products suggesting they are carcinogenic. The coalition argues this conflicts with federal regulations under the Federal Insecticide Fungicide and Rodenticide Act (FIFRA), which requires EPA approval of pesticide labels and preempts state-level labeling requirements that differ from federal standards.

  • The amicus brief was filed on March 5, 2026.
  • The Supreme Court is expected to hear arguments in the Monsanto v. Durnell case later this year.

The players

Austin Knudsen

The Attorney General of Montana, who joined a 15-state coalition supporting uniform national labeling requirements for farming herbicides.

Monsanto Company

An agricultural company that manufactures and sells glyphosate-based herbicide products, which are at the center of the legal dispute over labeling requirements.

Environmental Protection Agency (EPA)

The federal agency that regulates pesticides and has approved glyphosate as 'not likely to be carcinogenic to humans,' contradicting state-level warning label requirements.

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What’s next

The Supreme Court is expected to hear arguments in the Monsanto v. Durnell case later this year, which will determine whether federal regulations preempt state-level labeling requirements for glyphosate and other herbicides.

The takeaway

This case highlights the ongoing debate over the appropriate balance of federal and state regulatory authority in the agricultural sector. Uniform national standards help ensure consistent access and pricing for farmers, while state-level rules can create a patchwork that disrupts supply chains and raises costs.