Missouri AG Leads 15 States Supporting Uniform Herbicide Labeling

Detected March 19th, 2026

Summary

Missouri Attorney General Catherine Hanaway led a 15-state coalition in filing an amicus brief with the U.S. Supreme Court supporting uniform labeling requirements for herbicides like glyphosate. The brief argues against state-specific mandates that could disrupt supply chains and harm farmers.

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What changed

Missouri Attorney General Catherine Hanaway, joined by 14 other states, has filed an amicus brief with the U.S. Supreme Court in a case concerning the labeling of herbicides, specifically glyphosate. The brief supports the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) as the sole authority for nationwide, science-based labeling instructions. The coalition argues that state-level mandates, such as those potentially imposed by California, create undue litigation risk for manufacturers, threaten to disrupt supply chains, and could deprive farmers of essential tools, thereby harming agricultural economies.

This action is critical for agricultural firms and manufacturers who rely on consistent federal labeling standards. The filing aims to prevent a patchwork of state regulations that could lead to increased costs, reduced product availability, and potential legal liabilities for including warnings about carcinogenicity not supported by federal guidelines. Compliance officers should note the potential for significant legal and operational disruptions if state-specific labeling requirements are upheld, impacting product distribution and farmer access to key agricultural inputs.

What to do next

Review the amicus brief filed in the U.S. Supreme Court regarding herbicide labeling.
Assess potential impacts of state-specific herbicide labeling mandates on product availability and supply chains.
Monitor U.S. Supreme Court decisions on herbicide labeling requirements.

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Catherine L. Hanaway
Missouri Attorney General

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Catherine L. Hanaway
Missouri Attorney General

Attorney General Hanaway, Nebraska, Iowa File Brief To Support Uniform Labeling Requirements For Herbicides Used In Farming

Home 9 Press Release 9 Attorney General Hanaway, Nebraska, Iowa File Brief To Support Uniform Labeling Requirements For Herbicides Used In Farming JEFFERSON CITY, Mo. — Today, Missouri Attorney General Catherine Hanaway led a 15-state coalition that filed an amicus brief in the United States Supreme Court to support uniform labeling requirements for herbicides used in farming. This action supports farmer access to glyphosate, one of the most environmentally sound and widely used herbicides on the market.

“For decades, Missouri’s farmers have used glyphosate to protect our crops and food supply,” said Attorney General Hanaway. “United States law establishes strict labeling guidelines for products containing glyphosate. States like California have no right to impose their policy views on Missourians with overreaching, extraterritorial mandates.”

The case concerns the labeling requirements set by the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), which establishes consistent, science-based instructions nationwide. Yet, some courts have issued rulings that require manufacturers to include a warning label on glyphosate-containing products, suggesting they are carcinogenic or face massive legal liability. This litigation risk threatens to drive manufacturers from the market and deprive Missouri farmers of an essential tool for controlling weeds and maintaining high crop yields.

The States’ brief explains that without a uniform nationwide standard, states can establish labeling requirements that would increase costs, disrupt supply chains, and ultimately threaten access to glyphosate entirely. It also emphasizes the importance of agriculture to Missouri’s economy and outlines the harms that would arise if Missouri farmers were forced to use other, often more toxic, herbicides.

Joining Missouri on the brief were the Attorneys General of Iowa, Nebraska, Alabama, Georgia, Kansas, Kentucky, Louisiana, Montana, North Dakota, Oklahoma, Pennsylvania, South Carolina, South Dakota, and Utah.

Read the brief here.