The short version
- California has canceled all paraquat pesticide registrations, initiating a two-year phase-out of the herbicide.
- The ban follows legislative pressure and concerns over the chemical's link to Parkinson's disease and harm to endangered species.
- While Vermont previously banned the substance, California's move marks a significant shift for the US's largest agricultural producer.
California has officially moved to ban paraquat, a highly toxic herbicide that has been used extensively across American cropland for decades. The California Department of Pesticide Regulation (DPR) announced the cancellation of the state’s last remaining paraquat pesticide registration, signaling the end of an era for one of the most controversial chemicals in modern agriculture. The decision initiates a two-year phase-out period during which the substance will be gradually removed from use within the state.
The move places California as only the second US state to prohibit paraquat, following Vermont’s earlier ban. Public health advocates have celebrated the ruling as a major victory for community safety and environmental protection. Nathan Donley, environmental health science director at the Center for Biological Diversity, described paraquat as the most acutely lethal pesticide ever created. He noted that while the speed of the decision was unexpected, it represents welcome news for those who have long campaigned against its use.
Paraquat is a powerful weedkiller that has seen a dramatic increase in usage over the last two decades. Between 2008 and 2018, its application in the United States tripled, and usage has continued to rise since then. Approximately 14 million pounds of the chemical are sprayed annually on crops such as wine grapes, pistachios, almonds, walnuts, pears, citrus, soybeans, and cotton. Much of this usage is concentrated in California’s Central Valley and the Mississippi River Valley, making the state the largest consumer of the pesticide in the country.
The health risks associated with paraquat are severe and well-documented. Exposure through skin contact or inhalation has been linked to death, cancer, heart failure, kidney failure, liver failure, and lung scarring. There is no known antidote for paraquat poisoning, a fact emphasized by the Environmental Protection Agency’s warning that even a single sip can be fatal. Beyond acute toxicity, research indicates that paraquat interferes with dopamine production and regulation. Since people with Parkinson’s disease exhibit reduced dopamine levels, epidemiological studies have shown an increased incidence of the condition among agricultural workers and communities exposed to the herbicide.
The environmental impact of paraquat is also a significant concern. The chemical is considered highly harmful to wildlife, posing threats to at-risk species in California such as the San Joaquin kit fox and the Swainson’s hawk. These ecological dangers, combined with public health risks, have fueled years of pressure from farm worker groups and public health organizations urging both state and federal governments to restrict or ban the substance.
Despite these concerns, paraquat has remained legal in the United States at the federal level. The EPA reapproved the chemical for use in 2021 and again in 2024, maintaining its status as an available agricultural tool nationwide. This federal stance contrasts sharply with international regulations; more than 70 countries, including China, the United Kingdom, and members of the European Union, have already outlawed paraquat due to its toxicity.
The path to California’s ban was paved by legislative action in 2024, when the state legislature passed a law requiring the pesticide division to re-evaluate the health risks associated with paraquat. This mandate prompted the DPR to conduct a thorough review, ultimately leading to the decision to cancel registrations. The department characterized the industry’s cessation of use as voluntary, following the legislative directive.
As California implements its two-year phase-out, the agricultural sector must adapt to new weed management strategies. For advocates, the ban is a critical step toward reducing exposure to a chemical they describe as virtually proven to cause Parkinson’s disease. While the federal government has yet to follow suit, California’s status as the nation’s largest agricultural producer means this decision could influence national policy and public perception of pesticide safety in the years to come.
The resolution of paraquat’s future in the US remains uncertain. With other states potentially watching California’s lead, the debate over balancing agricultural efficiency with public health and environmental protection is likely to intensify. For now, however, the ban marks a definitive shift in how one of America’s most productive farming regions approaches chemical safety.
Sources behind this briefing
Go to the original reporting
- The Guardian US↗California bans paraquat, highly toxic herbicide outlawed in more than 70 countries
- Los Angeles Times↗California to phase out paraquat, a powerful weedkiller associated with serious health issues
- The New Lede↗California phasing out herbicide linked to Parkinson’s disease
