On January 9, 2026, the head of the U.S. Environmental Protection Agency (“EPA”) announced that the agency will reassess the safety of paraquat, an herbicide that remains legal in the United States despite bans in other countries. The decision reflects renewed scrutiny of paraquat’s health risks, particularly its alleged connection to Parkinson’s disease, and it signals a potential shift in federal pesticide policy. EPA officials have indicated that manufacturers will be required to provide stronger evidence that paraquat can be used safely under real world conditions, reopening a regulatory debate that has persisted for years.

The reassessment comes as thousands of individuals nationwide have filed lawsuits claiming that long term exposure to paraquat caused or contributed to their Parkinson’s diagnoses. Plaintiffs in these cases argue that manufacturers knew or should have known about paraquat’s neurological risks but failed to adequately warn users, while manufacturers continue to dispute any definitive causal link.

EPA’s review could have meaningful implications for both regulators and litigants. A finding that paraquat presents unreasonable risks could lead to tighter restrictions, new safety requirements, or a potential ban, aligning U.S. policy more closely with international approaches. At the same time, the agency’s conclusions may influence ongoing litigation by shaping how courts and juries view the scientific evidence surrounding paraquat and Parkinson’s disease.