California ends paraquat use as manufacturers withdraw registrations

California will eliminate paraquat, a highly toxic weedkiller, after manufacturers voluntarily surrendered their registrations, according to the California Department of Pesticide Regulation. Studies cited by state regulators associate the chemical with thyroid disorders, birth defects, and potential harm to birds, and thousands of workers have filed lawsuits claiming a connection to Parkinson's disease. The decision mirrors Vermont’s recent statewide prohibition and comes after legislation championed by former Assemblymember Laura Friedman required a safety review.

Companies, including major producer Syngenta, opted to cancel rather than fund new studies, signaling commercial concerns over the product’s future. Environmental groups praised the action, while the California Farm Bureau warned of challenges for growers reliant on the herbicide. The EPA has also begun its own reassessment of paraquat’s risks.