Paraquat Parkinson’s Disease Evidence Draws New EPA Safety Review

Manufacturers have been ordered to turn over evidence proving that current safety methods are effective in protecting workers and communities from Paraquat side effects.

A new review by federal regulators of the weed killer Paraquat could result in changes to protections needed to handle the herbicide, which recent science and litigation has linked to an increased risk of Parkinson’s disease.

The safety review was announced by Lee Zeldin, the administrator of the U.S. Environmental Protection Agency (EPA), in a post published on X on January 9.

Originally sold under the brand name Gramoxone, Paraquat was introduced to the market in 1962 and became commercially available in the U.S. in 1964. It is widely used nationwide to kill broadleaf weeds and grasses before planting numerous types of crops. Paraquat is also sometimes sprayed on plants during harvest to dry them out.

Paraquat Health Concerns

In March 2021, Greenpeace published a report now known as “The Paraquat Papers”, revealing a long history of Paraquat’s links to poisonings and the attempts of manufacturers to conceal those risks, which were mostly avoidable, yet have claimed tens of thousands of lives since the 1960s.

Consuming a single tablespoon of paraquat is likely fatal, and it has been accidentally, as well as intentionally, consumed thousands upon thousands of times over the decades, Greenpeace reported. The victims are often children, and deaths from Paraquat poisonings were particularly common in Asia, with Japan reaching 1,000 paraquat deaths per year in the 1980s. Other countries, such as China and Sri Lanka, have also seen hundreds of deaths per year.

Paraquat has been banned in more than 50 countries worldwide and was only allowed to stay on the U.S. market due to the addition of an emetic, which induces vomiting when swallowed. However, the Paraquat Papers indicate the safety features do not work.

Over the last five years, most of the science and concerns have been focused on a link between Paraquat and Parkinson’s disease, which can leave those exposed to it with chronic and progressive neurological problems, even when recommended safety precautions are taken. Data from the papers indicated that the manufacturers likely knew of research into Parkinson’s disease concerns dating back to at least as early as 2001.

This has led to more than 6,400 individuals pursuing Paraquat lawsuits in the federal court system, each raising similar allegations that the manufacturers failed to warn that farmers and agricultural workers may develop Parkinson’s disease, even when the product is used in accordance with safety instructions.

Zeldin did not mention what specific Paraquat safety issues were under review and only indicates that the administration was responding to new science that has raised questions. He indicated that the administration would respond to what the data shows.

However, while Zeldin indicates the administration is focused on stronger protections for the community and workers, he also notes that new restrictions may not be the final result.

“When accurate new studies reveal additional risk, we will be in a stronger position both scientifically and legally to tighten protections, require tougher rules, and limit uses as needed to protect workers, neighbors, and communities. When accurate studies do not show additional risk, communities can have greater confidence that the protections already in place are working as intended.”

– EPA Administrator Lee Zeldin

The agency will require manufacturers of the herbicide to “thoroughly prove that current uses are safe in real-world conditions,” Zeldin noted. He warned that those unable to show Paraquat’s safety will likely face decisive action.

Paraquat Parkinson’s Disease Lawsuits

Given similar questions of fact and law raised in Paraquat lawsuits filed throughout the federal court system, all cases have been consolidated as part of a multidistrict litigation (MDL) since June 2021, under U.S. District Judge Nancy Rosenstengal in the Southern District of Illinois for coordinated discovery and pretrial proceedings.

Judge Rosenstengal had scheduled the first of a series of bellwether trials to begin in October 2025, to help test how juries may respond to certain evidence and testimony likely to be repeated throughout the claims. However, the litigation has been paused for the past eight months as the parties reportedly work out the final details of a Paraquat lawsuit settlement agreement.

Late last month, Judge Rosenstengal extended the stay until March 6, 2026. However, if the parties determine that no Paraquat settlement can be reached, case-specific discovery would continue for the bellwether trials. It is unclear what the schedule for those trials would be.

While the outcome of any bellwether trials will not have a binding impact on other plaintiffs, they will be closely watched to help gauge how juries are likely to respond to certain evidence and testimony likely to be repeated if a Paraquat settlement is not finalized.

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