California canceled its last remaining paraquat pesticide registration on Tuesday and will phase out paraquat over two years. The move affects the state where paraquat is used more than anywhere else in the United States, including farming areas in the Central valley.
Nathan Donley, environmental health science director with the Center for Biological Diversity, called the decision “very welcome news” and said, “Paraquat is the most acutely lethal pesticide ever made.” He also said, “I don’t think anyone thought this was going to happen this quickly, but it’s very welcome news.”
California department of pesticide regulation
The California department of pesticide regulation said the cancellation followed a voluntary industry decision to stop using paraquat in California after the legislature passed a law in 2024 requiring regulators to begin re-reviewing the pesticide’s health risks. California is the second US state to prohibit paraquat after Vermont, and the change comes after years of concern about exposure through skin contact or inhalation.
Paraquat use has been tied to death, cancer, heart failure, kidney failure, liver failure and scarring of the lungs. A DPR preliminary review also found human health concerns, including associations between paraquat exposure and thyroid disease and reproductive health concerns.
California Farm Bureau
The California Farm Bureau opposed the law and said it bypassed the scientific review process. It also suggested at the time that it would sue, though no legal case has been filed. That dispute leaves California’s phase-out tied to both the regulatory decision and the industry’s own choice to stop using the herbicide.
The scale is large. About 14m pounds of paraquat are sprayed annually on US wine grapes, pistachios, almonds, walnuts, pears, citrus, soya beans, cotton and other crops. Paraquat use tripled in the US between 2008 and 2018, even as the Environmental Protection Agency reapproved it for use in 2021 and 2024.
Central valley
California’s action lands in a state that is already the US’s largest user of paraquat, and it follows concern among farm communities in the Central valley and other exposed areas. Public health advocates say the herbicide is among the most harmful pesticides to wildlife, and in California it threatened at-risk species such as the San Joaquin kit fox and the Swainson’s hawk.
For growers, the practical change is a phase-out, not an abrupt overnight ban. That means the remaining use period is limited, and the product’s place in California farming is now on a two-year countdown.
