What the U.S. Supreme Court’s pesticide ruling means for gardeners and farm workers

Containers of Roundup sit on a store shelf in San Francisco, Calif., in February 2019. (AP Photo/Haven Daley) What the U.S. Supreme Court’s pesticide ruling means for gardeners and farm workers Published: September 24, 2026 11.34am EDT Share article Print article In June, the United States Supreme Court ruled that state goverments’ duty-to-warn laws do not oblige chemical manufacturer Monsanto to disclose a cancer risk on its pesticide labels. Monsanto manufactures the well-known pesticide Roundup that has been the subject of thousands of lawsuits in the U.S. and Canada. The company argued that if the U.S. Environmental Protection Agency (EPA) does not require a cancer warning label, states cannot hold it liable in court for failing to warn consumers about cancer risks. In their decision, the U.S. Supreme Court made no pronouncements on whether glyphosate causes cancer, only that the EPA is the sole arbiter of label warnings. The decision also forbade anyone else from issuing cancer warnings — including states, lower courts and manufacturers — unless the EPA approves. The EPA maintains that there is “no evidence that glyphosate causes cancer in humans.” However, in 2015, the World Health Organization’s International Agency for Research on Cancer (IARC) classified glyphostate as “probably carcinogenic to humans.” The court’s decision relieves the sellers of hundreds of pesticides on the market from failure-to-warn obligations, not just glyphosate. Un-acknowledged regulatory bias Monsanto’s lawyers argued that the EPA “exhaustively studied” glyphosate and did peer review while the International Agency for Research on Cancer did not, and that the EPA reviewed more data and unique expert analysis. This is misleading. None of nearly three dozen briefs submitted by parties and friends of the court (industry groups, academics and environmental groups) told the court about the systemic bias of regulators. The EPA appears to have primarily made its decisions based on confidential data and studies provided by regulated companies, and largely ignored studies published in peer-reviewed scientific journals. Canadian, European and U.S. regulators seem to exhibit the same preference for company data and dismissive attitude over research published in peer-reviewed journals. For instance, a 2017 report on glyphosate from Health Canada, prepared with the EPA, acknowledged that Health Canada relies mainly on “seller-sponsored science.” The report also said…