Case guide

UPDATED FEB 2026

Paraquat EPA Ban

Part of the Paraquat Parkinson’s investigation

The short answer

Despite more than 70 countries banning paraquat and overwhelming scientific evidence linking it to Parkinson’s disease, the U.S. Environmental Protection Agency has repeatedly declined to ban the herbicide. The EPA’s 2024 registration review reaffirmed paraquat’s approval despite 90 studies submitted by the Michael J.

Fox Foundation. This regulatory failure is cited in the litigation as evidence that judicial remedies are necessary to protect American farmworkers and rural communities.

People's Justice Research TeamUpdated February 20, 2026Fact-checked

Verified against court and regulatory records · No upfront fees · Your information is never sold

Free Case Review

Check your eligibility — free

Answer 2-3 quick questions to review your potential case.

Free · Confidential · About 2 minutes · A case specialist responds within 1 business day

Your answers are never sold or shared without your consent.

Why 70+ Countries Have Banned Paraquat But the U.S. Has Not

The disparity between the international regulatory consensus and the EPA’s position on paraquat is one of the most striking aspects of this litigation. The European Union banned paraquat in 2007. China banned it in 2017. Brazil — the world’s largest agricultural market — banned it in 2020. Thailand, Malaysia, Peru, Chile, Taiwan, and dozens of other countries have followed. In total, more than 70 countries have determined that paraquat is too dangerous for use. Yet the United States, despite having access to the same scientific evidence, continues to allow approximately 10 million pounds of paraquat to be applied annually.

The EPA classified paraquat as a Restricted Use Pesticide in 1978, acknowledging its acute toxicity. However, the restriction was based on the risk of acute poisoning — not chronic neurological effects. In 2021, the EPA issued an interim registration review decision that added new safety mitigation measures (closed-system packaging, label changes, additional training requirements) but declined to ban the herbicide. In 2024, the EPA completed its full registration review and once again reaffirmed paraquat’s registration.

The 2024 decision was particularly controversial because the Michael J. Fox Foundation — the world’s largest non-profit funder of Parkinson’s research — submitted 90 scientific studies supporting the link between paraquat and Parkinson’s disease. The EPA declined to act on these submissions. Critics allege that industry lobbying and Syngenta’s documented "Scientific Influencing Strategy" have corrupted the EPA’s decision-making process.

What the EPA’s Failure Means for the Litigation

The EPA’s refusal to ban paraquat does not weaken the litigation — in many ways, it strengthens it. The contrast between the EPA’s position and the international regulatory consensus demonstrates that reasonable regulators reviewing the same evidence reached the opposite conclusion. The EPA’s failure to protect American workers, despite overwhelming evidence of neurological harm, supports the argument that judicial remedies are necessary when regulatory systems fail.

Plaintiffs’ attorneys cite the EPA’s inaction as evidence of regulatory capture and corporate influence over government decision-making. The documented history of Syngenta’s "Scientific Influencing Strategy," targeting of independent scientists, and lobbying efforts provides a factual basis for these arguments. The litigation thus serves a dual purpose: compensating individuals harmed by paraquat and holding manufacturers accountable in a way that the regulatory system has failed to do.

Research & evidence

Scientific Evidence

cross-sectional

Paraquat and Parkinson’s Disease: The Role of Corporate Agnotology

Dorsey ER, et al. (2023). Movement Disorders

Key findings

  • Syngenta’s corporate predecessor ICI identified paraquat neurotoxicity in 1958 and confirmed brain penetration in 1966
  • The Louise Marks studies documenting substantia nigra cell loss in paraquat-exposed animals were suppressed and not reported to regulators
  • Syngenta’s 2003 "Scientific Influencing Strategy" was a coordinated effort to selectively publish favorable research while discrediting independent scientists
  • Syngenta specifically targeted Dr. Deborah Cory-Slechta and hired v-Fluence to manage reputation and influence scientific discourse
  • The pattern mirrors tobacco industry agnotology documented by Proctor and others, representing a deliberate corporate strategy to maintain a profitable product at the expense of public health
meta-analysis

Exposure to Pesticides or Solvents and Risk of Parkinson Disease (Meta-Analysis)

Pezzoli G, Cereda E. (2013). Neurology

Key findings

  • Paraquat exposure was associated with an overall odds ratio of 1.64 for Parkinson’s disease, confirming a statistically significant increased risk
  • The association was consistent across multiple independent studies conducted in different countries and populations
  • Herbicide and pesticide exposure in general was associated with a pooled odds ratio of 1.62 for Parkinson’s disease
  • The meta-analytic approach provides the aggregated statistical power that individual studies cannot achieve, strengthening the causal inference
cohort

Rotenone, Paraquat, and Parkinson’s Disease (FAME Study)

Tanner CM, Kamel F, Ross GW, et al. (2011). Environmental Health Perspectives

Key findings

  • Paraquat users had a 2.5-fold (250%) increased risk of Parkinson’s disease compared to non-users
  • The association was statistically significant and persisted after controlling for confounding variables including age, sex, smoking, and other pesticide exposures
  • Rotenone use was also associated with increased Parkinson’s risk (2.5x), and both compounds inhibit mitochondrial complex I through similar mechanisms
  • The study used objective pesticide application records rather than self-reported exposure, substantially reducing recall bias

FAQ

Frequently Asked Questions

36 QUESTIONS

Yes. Thousands of lawsuits have been filed against Syngenta, Chevron Phillips Chemical, and Growmark alleging that paraquat exposure caused Parkinson’s disease. These cases are consolidated in MDL 3004 in the Southern District of Illinois. The litigation alleges that manufacturers knew paraquat was neurotoxic, suppressed research documenting the link to Parkinson’s disease, and failed to warn users of the neurological risks. You may have a legal claim if you were exposed to paraquat through agricultural work, residential proximity to treated fields, or other contact and have been diagnosed with Parkinson’s disease. Attorneys handle these cases on contingency. Fee arrangements vary, so confirm terms with any attorney you consult.

Dive deeper

Related Guides

7 GUIDES

The full investigation

Part of the Paraquat Parkinson’s Investigation