California Initiates Paraquat Phase-Out, All Manufacturers Voluntarily Cancel Product Registrations

en.Wedoany.com Reported - Recently, the California Department of Pesticide Regulation (DPR) announced that all manufacturers of pesticide products containing the active ingredient paraquat dichloride have voluntarily canceled their registrations in California, officially marking the beginning of a gradual phase-out of this herbicide's use in the state.

DPR initiated the paraquat reevaluation in November 2024, in accordance with the requirements of Section 14086 of the Food and Agricultural Code, and released two preliminary scientific assessment reports the following month. DPR's preliminary reports found that paraquat exposure may be potentially associated with thyroid effects and birth defects. The reports also noted that paraquat may cause adverse effects on other organisms, with the most significant risk posed to birds.

The DPR Director stated that obtaining accurate data is a prerequisite for identifying risks to human health and the environment, and this is the core of the department's ongoing evaluation mechanism—designed to keep pace with the evolving science surrounding pesticide impacts.

Reevaluation Triggers Data Requirements, Manufacturers Choose Voluntary Cancellation

The reevaluation mechanism grants DPR the authority to require registrants (i.e., pesticide manufacturers) to conduct and submit new scientific studies to fully understand emerging risks that were unknown at the time of registration. For paraquat, DPR exercised this reevaluation authority, requiring registrants to submit scientific data by June 5, 2026, to address newly identified data gaps in the department's human health toxicology database, along with other compliance requirements. However, some companies chose not to provide the required data and began voluntarily canceling their paraquat pesticide product registrations in California starting in April 2026. The final registrant completed the voluntary cancellation process on August 6, 2026.

Transition Arrangements for Dealers and Growers

Under California law, licensed dealers may continue to possess and sell voluntarily canceled pesticide products for up to two years following the effective date of each product's registration cancellation. Growers who continue to use these products must comply with all applicable label instructions, use requirements, and state and federal regulations.

The DPR Director stated that to achieve systemic change in California's pest management framework, DPR plays a critical role in supporting increased research and outreach to advance the state's transition toward safer, more sustainable pest management practices. During the transition period as growers phase out paraquat use, the department will leverage existing tools to support the adoption of effective alternatives and the promotion of Sustainable Pest Management (SPM).