Syngenta Voluntarily Cancels Registration of Paraquat Pesticides in California

Effective April 1, 2026, pesticide registrant Syngenta has voluntarily cancelled registration of the pesticide Gramoxone® SL 3.0 in California, a product that contains the active ingredient paraquat-dichloride (paraquat).

Paraquat is an herbicide used to kill weeds and can only be used by professionally licensed applicators. The California Department of Pesticide Regulation (DPR) and United States Environmental Protection Agency (U.S. EPA) have both designated paraquat as a restricted material, which means only licensed dealers can sell the pesticide and only licensed applicators are allowed to use it. Paraquat is currently under reevaluation by DPR. Reevaluation is one of DPR’s processes to identify and mitigate risks, particularly to require new studies or data generation to inform its evaluation.

Products containing paraquat that are registered by other companies are not affected by Syngenta’s voluntary cancellation. These products are still under reevaluation at DPR and retain the same legal requirements.

Under California law, Gramoxone® SL 3.0 may continue to be possessed and sold by DPR-licensed dealers for up to two years following the effective date of the company’s voluntary cancellation (April 1, 2028). Growers must continue to use these products in accordance with all applicable label directions, use requirements, and state and federal regulations. Syngenta has indicated that it will continue its existing stewardship practices, including training and safety resources, while remaining stocks are distributed and sold.

As part of DPR’s commitment to advance its reevaluation of paraquat products in alignment with Assembly Bill 1963 (Chapter 688, Statutes of 2024), DPR will continue to move through the process for remaining paraquat products registered in California. The Department has already released two preliminary scientific assessments and will continue to require data and additional information from remaining registrants. The reevaluation is scheduled for completion by January 2029.

Status updates for this reevaluation and other continuous evaluation actions to mitigate pesticide impacts can be found on DPR’s Continuous Evaluation and Mitigation Update webpage.