Question: What is the status of state proposals that restrict or ban the sale and use of the herbicide “paraquat”?

Paraquat is a synthetic, nonselective contact herbicide that was first registered in the United States in 1964. It was one of the most widely used herbicides until 1996, when glyphosate became a more popular choice. According to the U.S. Environmental Protection Agency (EPA):

“Paraquat is a rapidly acting, broad-spectrum, contact herbicide used for weed control and as a desiccant. It is applied to the foliage of weeds as a burn-down treatment before planting, to control weeds in non-agricultural lands, or to desiccate crops prior to harvest.

“Paraquat is a non-selective herbicide … which kills the green plant tissues on contact. Unlike many other herbicides, paraquat is effective under low temperatures and when weeds are not actively growing (e.g., early season seedbed preparation). Rainfall soon after application has little or no effect on its performance, unlike most other herbicides.

“The paraquat that contacts the soil is deactivated by tight adsorption to clay particles. This property allows it to be applied immediately before planting crops or seedling emergence. Paraquat is an important pre-harvest desiccation treatment used on cotton and potatoes.”

According to the National Agricultural Law Center, paraquat usage is highest on soybeans, cotton, corn, grapes, pistachios and peanuts. The application of paraquat has increased in recent years because it is effective at controlling weeds that have become resistant to glyphosate. Glyphosate and paraquat are also commonly used to terminate cover crops prior to spring planting.

Map is from the U.S. Department of Agriculture

National estimates indicate that paraquat use in the United States totals several million pounds annually, with modeled data from the U.S. Geological Survey suggesting usage has approached or exceeded 10 million pounds in recent years.

Paraquat is banned in approximately 70 countries worldwide. The European Union banned the product in 2007 following a court determination that the regulatory agency failed to properly evaluate human health risks. The EU ban applies to all 27 countries, and the United Kingdom maintained its ban post-Brexit. China banned the product in 2017, Brazil in 2020.

In Canada, Syngenta was the only paraquat manufacturer with a registered product. Syngenta discontinued registering its product in Canada in 2023 following updated risk-mitigation efforts. Although there is not an outright ban, no paraquat products are sold in Canada.

The herbicide remains available in Australia, India, Mexico, New Zealand and Russia, among many other nations.

Paraquat is highly toxic, according to the U.S. Environmental Protection Agency, which warns that “one small sip can be fatal and there is no antidote.” The EPA regulates paraquat under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), which means the product must be registered before it can be sold with an affixed EPA-approved (and legally enforceable) label. The EPA must also conduct a product review every 15 years.

Due to its toxicity, paraquat is designated as a “restricted use pesticide” and can only be applied by trained, certified applicators.

Its label specifies that the “product cannot be used in a way that causes contact with workers or others, either directly or through drift.” Paraquat cannot be used “in residential or public recreational settings (for example, homes, home gardens, schools, recreational parks, golf courses, and/or playgrounds).” The complete 44-page label is linked here.

Syngenta and its predecessors were the initial manufacturers selling paraquat under the brand name Gramoxone. Generic formulations of paraquat are now produced by many manufacturers. On March 3, 2026, Syngenta announced that it would stop manufacturing the product worldwide.

• 1964 — Paraquat is initially registered.
• 1988 — The Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) is amended, requiring a one-time reregistration of all pesticides approved prior to Nov. 1, 1984.
• 1996 — FIFRA is amended and requires the EPA to review pesticides every 15 years going forward.
• 1997 – Re-registration of paraquat is completed pursuant to the 1988 FIFRA amendment.
• 2011 — The first modern 15-year review begins. This review is ongoing and not completed (as of March 2026).
• 2021 — The EPA issued a final interim decision based on work commenced during the 2011 review: “After a thorough review of the best available science, as required under FIFRA, the EPA has not found a clear link between paraquat exposure from labeled uses and adverse health outcomes such as Parkinson’s disease and cancer.” The final interim decision also established stronger protections to reduce exposure to paraquat, including:
  • “Limit aerial applications to a maximum of 350 acres per applicator per 24-hour period for all uses except cotton desiccation; require a residential area drift buffer for all aerial applications; prohibit use of human flaggers; prohibit pressurized handgun and backpack sprayer application methods; require a 48-hour restricted entry interval (REI) for all crop desiccations, except cotton desiccation requires a 7-day REI; and require mandatory spray drift management label language.”
• 2024 — Pursuant to FIFRA regulations requiring pesticide registrants to submit to the EPA any new information regarding unreasonable adverse effects, Syngenta submitted a study indicating paraquat may vaporize differently than initially understood.
• 2025 — Upon review of the information from Syngenta, the EPA requested that all manufacturers submit further volatilization research and data. The volatilization review remains ongoing (as of March 2026).

There are several spheres of litigation regarding paraquat.

• Product liability lawsuits | Federal litigation and courts
  • These claims arise from individuals claiming injury from paraquat exposure, and the suits are filed against the manufacturers, primarily Syngenta and Chevron. Plaintiffs most commonly allege a link between paraquat and the development of Parkinson’s disease.
  • There are approximately 8,000 cases pending in federal court, many of which have been combined into multi-district litigation (MDL class actions).
• Product liability lawsuits | State litigation and courts (about 2,500 cases pending nationwide)
  • These cases have similar claims to their federal counterparts but are made in state courts where differing standards of proof and state procedural rules apply.
  • California and Pennsylvania have a particularly high volume of cases, many of which have been combined — thus forming a mass tort.
  • Many cases at both the federal and state levels also allege that manufacturers failed to warn users of known dangers associated with the product and rely upon legal theories of fraud and misrepresentation in demanding punitive damages.
• Lawsuits filed under the U.S. Administrative Procedures Act
  • These suits challenge the EPA’s 2021 interim decision (see above) as deficient in evaluating human health risks, particularly with regard to Parkinson’s disease.

Notably, and unlike cases involving glyphosate, there has not been a trial involving claimants and paraquat manufacturers. Rather, many cases have been resolved through settlements. In 2021, Syngenta and Chevron settled cases involving paraquat and those claiming links to Parkinson’s disease for $187 million.

Central to the debate are research studies on paraquat and Parkinson’s disease; these studies span more than two decades and presents mixed findings. Syngenta maintains that “despite decades of investigation and more than 1,200 epidemiological and laboratory studies of paraquat, no scientist or doctor has ever concluded in a peer-reviewed scientific analysis that paraquat causes Parkinson’s disease.”

Due to ethical limitations of research studies, opponents of paraquat use suggest that direct causation is too high of a standard; for decades, these opponents say, studies have shown associations between paraquat exposures and increased rates of Parkinson’s disease.