California paraquat herbicide phaseout

California has initiated a phaseout of the herbicide paraquat following a regulatory reevaluation. The California Department of Pesticide Regulation announced that manufacturers have voluntarily agreed to withdraw their products from the market. This move follows a June 5 deadline in which companies failed to submit required scientific data to address gaps in the human health toxicology database.

State assessments have identified potential links between paraquat exposure and thyroid issues, birth defects, and risks to wildlife, including birds. Some studies have also associated the chemical with Parkinson’s disease. While the chemical is banned in over 60 countries, it has remained legal in the United States, with significant use in California for crops like almonds, grapes, and cotton.

Major manufacturers, such as Syngenta, have begun canceling registrations. Although the phaseout is underway, licensed dealers may continue to sell existing stock for up to two years after a product's cancellation, potentially allowing the chemical to remain in commerce until 2028. The transition has drawn mixed reactions, with environmental advocates pushing for removal while some farmers argue the herbicide is essential for weed management and preventing soil erosion.