The California Department of Pesticide Regulation (DPR) has announced that all manufacturers of pesticide products containing the active ingredient paraquat-dichloride (paraquat) have voluntarily cancelled their product registrations, beginning the phase-out of the use of paraquat in California. Reevaluation gives DPR the authority to require registrants – the companies that make pesticides – to develop and submit new scientific studies needed to fully understand emerging risks that were unknown at the time of registration. For paraquat, DPR invoked this reevaluation authority to require registrants to submit scientific data by June 5, 2026, to address newly identified gaps in DPR’s human health toxicology database, among other requirements. In lieu of providing required data, companies began voluntarily cancelling registration of paraquat pesticide products in California in April, with the last registrant voluntarily cancelling its registration on August 6, 2026. Under California law, DPR-licensed dealers may continue to possess and sell pesticides that were voluntarily canceled for up to two years following the effective date of each product’s cancellation. Growers who continue to use these products must act in accordance with all applicable label directions, use requirements, and state and federal regulations.