The international landscape for agricultural chemicals is witnessing a profound shift as a growing number of nations and several high-profile U.S. states move to eliminate the use of paraquat, a highly potent herbicide. While much of the industrialized world—and even the pesticide’s home manufacturing base in China—has moved to ban or severely restrict the chemical due to its links to incurable neurological diseases, the United States Environmental Protection Agency (EPA) remains a notable outlier. As federal regulators continue to permit the application of paraquat across millions of acres of American farmland, a complex conflict is emerging between agricultural necessity, corporate interests, and an evolving body of scientific research that points to a significant public health crisis.
The Global Retreat from Paraquat: A Four-Decade Timeline
The movement to phase out paraquat is not a recent phenomenon; rather, it is the culmination of more than forty years of escalating concern. Sweden was the first nation to take a definitive stand, banning the chemical in 1983. At the time, Swedish regulators cited the pesticide’s extreme acute toxicity and the lack of an effective antidote for accidental or intentional ingestion. This move set a precedent in Scandinavia and eventually across the European Union.
In 2007, the European Union’s Court of First Instance annulled the directive that had previously authorized paraquat, effectively ending its legal use across the member states. The court’s decision was rooted in the failure of the European Commission to properly account for the chemical’s potential to cause Parkinson’s disease and its high risk to wildlife and farmworkers.
Perhaps most significant is the stance taken by the Chinese government. Syngenta, the primary global manufacturer of paraquat, was acquired by the state-owned China National Chemical Corporation (ChemChina) in 2017. Despite this corporate ownership, the Chinese Ministry of Agriculture and Rural Affairs began a phased withdrawal of paraquat for domestic use, culminating in a total ban on the sale and use of liquid paraquat in 2020. Chinese officials reached this decision after internal studies corroborated international findings regarding the pesticide’s safety profile. Today, while China remains a major producer of paraquat for export to the United States and other markets, its use within its own borders is prohibited.
Scientific Evidence and the Parkinson’s Connection
The primary driver behind the modern push for a ban is the mounting evidence linking paraquat exposure to Parkinson’s disease, a progressive and incurable nervous system disorder that affects movement. Unlike many other pesticides, paraquat is a redox-active chemical that generates reactive oxygen species, leading to oxidative stress—a mechanism that scientists believe is central to the destruction of dopaminergic neurons in the brain.
A landmark 2011 study conducted by the National Institutes of Health (NIH) and the National Institute of Environmental Health Sciences (NIEHS), known as the Agricultural Health Study, found that farmers who used paraquat were 2.5 times more likely to develop Parkinson’s disease compared to those who did not. Subsequent research has only reinforced these findings. A 2012 study published in the journal Environmental Health Perspectives suggested that individuals with a specific genetic predisposition were particularly vulnerable to the chemical’s neurotoxic effects.
Furthermore, the "Paraquat Papers"—a cache of internal corporate documents released during ongoing litigation—suggest that manufacturers were aware of the chemical’s potential to migrate into the brain decades ago. These documents indicate that as early as the 1960s and 70s, scientists within the industry were examining the pesticide’s impact on the central nervous system, yet the findings were allegedly downplayed in public and regulatory filings.
Domestic Divergence: Vermont and California Take the Lead
In the absence of federal action, individual U.S. states have begun to implement their own restrictions. Vermont recently became a pioneer in this regard, passing legislation to ban the use of paraquat within its borders. Lawmakers in Montpelier specifically highlighted the association between the herbicide and Parkinson’s disease, arguing that the protection of agricultural workers and rural residents outweighed the chemical’s utility in weed management.
Even more impactful is the recent shift in California, the nation’s largest agricultural producer. In August 2026, the California Department of Pesticide Regulation (DPR) announced a voluntary cancellation of all pesticide products containing paraquat dichloride. This decision followed a rigorous state-level review and new research identifying significant health concerns that could not be mitigated through traditional label restrictions. The voluntary withdrawal by manufacturers avoids a lengthy legal battle over a mandatory ban but effectively removes the product from one of the most significant markets in the world.
The move in California is seen as a turning point. Historically, California’s regulatory decisions often serve as a bellwether for other states and can influence federal policy. With the state’s massive almond, grape, and citrus industries now forced to find alternatives, the economic arguments for maintaining paraquat use are beginning to weaken.
The EPA and the Regulatory Standoff
Despite the actions of international bodies and state governments, the U.S. Environmental Protection Agency continues to defend its authorization of paraquat. In its 2021 interim registration review decision, the EPA concluded that while there are risks associated with the chemical, they can be managed through "mitigation measures," such as requiring specialized training for applicators and prohibiting application via certain types of equipment.
The EPA has consistently downplayed the strength of the link to Parkinson’s disease, stating that the current body of peer-reviewed literature does not provide a "clear and consistent" causal relationship. This stance has drawn sharp criticism from environmental advocacy groups, public health organizations, and the Michael J. Fox Foundation for Parkinson’s Research.
In June 2026, the EPA announced it would hold a public roundtable over the summer to re-examine the "safety challenges" associated with paraquat. The announcement was initially met with cautious optimism by critics who hoped for a transparent review of new evidence. However, as the summer progressed, the event was never scheduled, and no further updates were provided. This perceived lack of urgency has fueled accusations that the agency is prioritizing the interests of the chemical industry over public safety.
Syngenta and the Corporate Defense
Syngenta, the leading manufacturer of paraquat (sold under the brand name Gramoxone), maintains that the chemical is safe when used according to the label. The company emphasizes that paraquat is a vital tool for "no-till" farming, a practice that reduces soil erosion and carbon runoff by allowing farmers to clear weeds without plowing the earth.
In statements regarding the mounting litigation—which includes thousands of lawsuits filed by Parkinson’s patients—Syngenta has argued that the scientific studies linking the pesticide to the disease are flawed or fail to account for other environmental factors. The company asserts that paraquat has been a cornerstone of global food security for over 50 years and that a ban would lead to decreased crop yields and increased food prices, particularly in the production of corn, soy, and cotton.
However, the "Paraquat Papers" have created a significant public relations and legal challenge for the company. These documents suggest that Syngenta (and its predecessor, Imperial Chemical Industries) worked to steer the EPA away from looking too closely at the brain-related risks of the chemical. The revelation of these internal communications has become a focal point for federal lawmakers who are currently pushing for the "Protect America’s Children from Toxic Pesticides Act," which would implement a nationwide ban on paraquat.
Agricultural Necessity vs. Public Health Costs
The debate over paraquat is fundamentally an analysis of risk versus utility. From an agricultural perspective, paraquat is highly effective at killing "superweeds" that have developed resistance to glyphosate (Roundup). As glyphosate-resistant weeds spread across the American Midwest and South, farmers have increasingly turned to paraquat as a "burn-down" herbicide to clear fields before planting.
According to data from the U.S. Geological Survey, paraquat use in the U.S. doubled between 2013 and 2018, reaching approximately 10 million pounds applied annually. This surge in use correlates directly with the rise of herbicide-resistant weeds.
On the other side of the ledger are the staggering costs of Parkinson’s disease. The economic burden of Parkinson’s in the U.S. is estimated to be $52 billion per year, a figure that includes direct medical costs and indirect costs such as lost wages and caregiver burden. Critics of the EPA argue that even a small increase in the risk of such a debilitating disease represents an unacceptable trade-off for the convenience of a specific herbicide, especially when alternative weed-management strategies exist.
Future Outlook and Legal Implications
The future of paraquat in the United States likely hinges on two factors: the outcome of mass tort litigation and the pressure from state-level bans. With California and Vermont leading the way, other states with strong environmental protection mandates, such as Oregon and Washington, are expected to review their own paraquat authorizations.
In the judicial system, the first "bellwether" trials for paraquat-related Parkinson’s claims are moving through federal courts. These trials will serve as a test for how juries perceive the scientific evidence and the internal corporate documents. If these cases result in significant judgments against manufacturers, the financial liability may eventually force a withdrawal of the product from the U.S. market, regardless of the EPA’s stance.
Furthermore, the EPA is under a court-ordered deadline to finish its review of paraquat by early 2027. This review must address the concerns raised by the Ninth Circuit Court of Appeals, which previously ruled that the EPA had not sufficiently analyzed the risks to farmworkers.
As the global consensus against paraquat continues to solidify, the United States finds itself at a crossroads. The discrepancy between the EPA’s findings and those of the rest of the world has created a fragmented regulatory environment that leaves millions of Americans exposed to a chemical that much of the world has deemed too dangerous to use. Whether through legislative action, judicial rulings, or a shift in federal regulatory policy, the era of paraquat use in American agriculture appears to be entering its final, most contentious chapter.
