By The Ranch News Team
The U.S. Supreme Court has handed Monsanto a major legal victory, ruling that federal pesticide labeling laws prevent states from requiring additional cancer warnings on Roundup herbicide labels.
In a 7-2 decision issued Thursday, the nation’s highest court determined that manufacturers cannot be held liable under state failure-to-warn laws when their product labels have already been approved by the U.S. Environmental Protection Agency.
The ruling centers on the Federal Insecticide, Fungicide, and Rodenticide Act, commonly known as FIFRA. Under that law, pesticide labels must receive EPA approval before products can be sold, and manufacturers are not free to make changes unless the agency authorizes them.
The Supreme Court concluded that because the EPA has repeatedly approved Roundup’s labeling without requiring a cancer warning, state courts cannot impose different labeling requirements through lawsuits.
The case stemmed from a Missouri lawsuit filed by gardener John Durnell, who claimed years of exposure to Roundup caused him to develop non-Hodgkin’s lymphoma. A Missouri jury awarded Durnell $1.25 million in 2023 after finding Monsanto failed to warn users about the herbicide’s alleged cancer risk. Missouri appellate courts allowed that verdict to stand, prompting Monsanto to appeal to the Supreme Court.
The decision is expected to have wide-reaching effects, potentially limiting thousands of similar lawsuits filed across the country involving Roundup and its active ingredient, glyphosate.
Glyphosate has remained the subject of scientific debate for years. In 2015, the International Agency for Research on Cancer classified the chemical as “probably carcinogenic to humans.” However, the EPA has repeatedly reviewed the available research and continues to maintain that glyphosate is not likely to cause cancer when used according to label directions.
Because of those findings, the EPA has consistently declined to require cancer warning labels on glyphosate-based herbicides.
Bayer, which acquired Monsanto in 2018, welcomed the ruling, saying it provides greater regulatory certainty for agriculture and other industries that rely on federal product approvals. The company also said it remains committed to resolving remaining Roundup litigation through a proposed multibillion-dollar settlement currently awaiting approval in a Missouri court.
Although Bayer no longer markets consumer Roundup products containing glyphosate in the United States, glyphosate-based herbicides continue to play a significant role in crop production. The herbicide remains one of the most widely used weed control tools in American agriculture, particularly in corn, soybean, cotton, and other row crop systems.
The ruling reinforces the EPA’s authority over pesticide labeling and could shape future legal challenges involving federally regulated crop protection products.