Paraquat vs Roundup Lawsuit: How They're Different
Two of the largest agricultural-chemical mass torts in U.S. history — and they have almost nothing in common except that people confuse them.
Side-by-side overview
| Paraquat | Roundup | |
|---|---|---|
| Active ingredient | Paraquat dichloride | Glyphosate |
| Defendants | Syngenta AG, Chevron U.S.A. | Bayer AG (Monsanto) |
| Primary injury | Parkinson's disease | Non-Hodgkin lymphoma |
| Federal MDL | MDL 3004 (S.D. Ill.) | MDL 2741 (N.D. Cal.) |
| PA state court | Active Philadelphia mass tort (~1,799 cases) | Limited PA presence |
| Mechanism | Oxidative stress, dopaminergic neuron loss | DNA damage, immune dysregulation (disputed) |
| EPA classification | Restricted Use | General Use |
| 2026 status | April 2025 settlement framework; Syngenta discontinued U.S. production March 2026 | $10B+ paid; ongoing trials; Monsanto v. Durnell preemption case |
Why people confuse them
Both are herbicides. Both are used in U.S. agriculture. Both are subject to mass tort litigation against major chemical companies. And both are commonly handled by the same farmworkers. The superficial similarity ends there.
Different injuries, different science
Paraquat is associated with Parkinson's disease through a well-characterized mechanism: redox cycling, oxidative stress, selective dopaminergic neuron loss. The peer-reviewed literature is mature.
Roundup (glyphosate) is associated with non-Hodgkin lymphoma. The science on glyphosate is more contested. The IARC classification of glyphosate as "probably carcinogenic to humans" (Group 2A) has been challenged by EPA and other regulators. Roundup cases have nonetheless produced billion-dollar verdicts in California and Missouri.
Why paraquat cases may be stronger on causation
Causation is the central battleground in both litigations. Paraquat causation has three things working in its favor:
- Mechanism is well-characterized. Redox cycling and oxidative stress are textbook neuroscience.
- Animal models are robust. Paraquat reliably produces parkinsonian features in rodent models — the experimental basis is uncontroversial.
- Human epidemiology is consistent. The Agricultural Health Study, Tanner case-control studies, and meta-analyses all point the same direction.
Roundup causation is good but more contested. The IARC vs EPA divergence on glyphosate has given defendants more room to argue causation than they have in paraquat.
Different defendants, different posture
Syngenta (paraquat manufacturer) is owned by ChemChina. Chevron (paraquat U.S. distributor) is a major oil company with deep pockets and complex corporate counsel relationships. Defendants have different settlement appetites in paraquat than Bayer has in Roundup.
Bayer (Roundup) has paid more than $10 billion in settlements and verdicts and continues to face new trials. Bayer's settlement strategy has historically been aggressive but inconsistent.
Forum: Pennsylvania matters more in paraquat
The Pennsylvania state court paraquat program in Philadelphia is currently the most influential non-MDL paraquat docket in the country. Roundup has never built a comparable Pennsylvania state court presence.
If you have both exposures
Many farmworkers handled both paraquat and Roundup over their careers. Cancer diagnoses and Parkinson's diagnoses are different, and the cases proceed separately — but a single intake call can evaluate both.
Read more: Full lawsuit comparison → · Check eligibility →