Paraquat Exposure: How It Happens, Who Is Most at Risk and What to Do Next

The people most at risk of paraquat exposure are the ones who mixed, loaded and sprayed it. Paraquat is a restricted-use weed killer that only licensed applicators may use, and the CDC says people with licenses to use paraquat are the most at risk for exposure. Farmers, farmworkers and applicators who handled it, and people who lived or worked beside treated fields, are the groups most often asking whether their paraquat exposure matters for their health or for a claim.

SourceCDC fact sheetUpdated 10 Jun 2026

This guide explains how paraquat exposure happens, who is most at risk, what the EPA has changed to reduce exposure, what is known about paraquat and Parkinson’s disease, and which records help show that you were exposed. Every fact links to the agency, court or study it comes from. If you were exposed and later diagnosed with Parkinson’s disease, a free paraquat case review takes about two minutes.

Paraquat Exposure Guide: Contents

What Paraquat Is and Who Is Allowed to Use It

Paraquat dichloride is an herbicide used to kill weeds and grass. The EPA calls it an important tool for the control of weeds in many agricultural and non-agricultural settings, and the CDC says it is used usually for weed and grass control. It is not a garden product: according to the EPA, there are no homeowner uses and no products registered for application in residential areas.

The EPA classifies paraquat as restricted use, which, in the CDC’s words, means that it can be used only by people who have licenses. Use is concentrated on farms. The EPA’s 2021 interim decision reported an average of 8.5 million pounds applied annually to 15.8 million acres, and found that, based on 2014–2018 usage data, soybeans, cotton, and corn are the crops with the highest number of total acres treated with paraquat. On August 10, 2026, California’s pesticide regulator announced the voluntary cancellation of all pesticide products containing paraquat dichloride in the state.

SourcesEPA paraquat pageUpdated 13 Nov 2025CDC fact sheetUpdated 10 Jun 2026EPA 2021 decisionJul 2021California DPR10 Aug 2026

How Paraquat Exposure Happens

There are three main routes of paraquat exposure. The CDC says the most likely way to be poisoned by paraquat is ingestion (swallowing), that paraquat poisoning is also possible after skin exposure, and that if it is breathed in, paraquat could cause poisoning that causes lung damage. The NIOSH Pocket Guide lists the exposure routes as inhalation, skin absorption, ingestion, skin and/or eye contact.

For workers, paraquat exposure is tied to handling the concentrate and the spray, which is why the EPA’s safety rules focus on training, closed-system packaging and drift controls. Accidental swallowing has been the deadliest route: the EPA reported in 2019 that since 2000, 17 deaths have been caused by accidental ingestion of paraquat.

SourcesCDC fact sheetUpdated 10 Jun 2026NIOSH Pocket GuideCurrent pageEPA training notice8 Mar 2019

Who Is Most at Risk of Paraquat Exposure

The CDC is direct: people with licenses to use paraquat are the most at risk for exposure. That group includes private applicators, mostly farmers, and commercial applicators who spray for others. Farmworkers who used it under an applicator’s supervision before the EPA barred uncertified workers from using it, family members on the farm, and people who lived or worked beside treated fields also ask about paraquat exposure (see the safety rules below).

The Agricultural Health Study, funded by the National Cancer Institute and the National Institute of Environmental Health Sciences, enrolled farm pesticide users in the 1990s. Between 1993 and 1997, 52,394 licensed private pesticide applicators (mostly farmers) from Iowa and North Carolina enrolled, as did 32,345 of their spouses, and the study also included 4,916 commercial applicators in Iowa.

SourcesCDC fact sheetUpdated 10 Jun 2026NIH Ag Health StudyCurrent page

Paraquat Drift and Vapor: What the EPA Is Studying

People who never handled paraquat may still ask about drift from nearby fields. The EPA’s 2021 decision found that the majority of spray drift risk concerns result from aerial applications, and the measures the agency adopted require mandatory spray drift management label language and a residential area drift buffer for all aerial applications.

Vapor is the newer question. On November 13, 2025 the EPA said there is greater uncertainty regarding the potential for paraquat to volatilize than previously considered. Its science memo, dated October 30, 2025, notes that non-occupational bystander inhalation exposure from volatilization may occur from residues on foliage or soil from fields previously treated with a pesticide. On June 30, 2026 the EPA said it had issued a Data Call-In Notice requiring paraquat manufacturers to conduct a field volatility study under real-world agricultural conditions.

SourcesEPA 2021 decisionJul 2021EPA paraquat pageUpdated 13 Nov 2025EPA update13 Nov 2025EPA science memo30 Oct 2025EPA news release30 Jun 2026

Paraquat Safety Rules Since 2016

The EPA tightened the rules after a run of poisonings. In December 2016 it announced that uncertified individuals working under the supervision of a certified applicator will be prohibited from using paraquat. Since 2019, certified applicators must now take paraquat-specific training before use, and the rules require closed-system packaging for all non-bulk (less than 120 gallon) end use product containers of paraquat. The EPA’s training page adds that the training must be retaken every three years.

These dates help date your own paraquat exposure. Someone who handled paraquat as an uncertified farmworker before the 2016 change, or poured it from open containers before closed systems arrived, may have had more direct contact than an applicator using a closed system today.

SourcesEPA action15 Dec 2016EPA training notice8 Mar 2019EPA training pageUpdated 8 Jan 2026

Paraquat Exposure and Parkinson’s Disease

The link between paraquat exposure and Parkinson’s disease is disputed. A 2011 study of pesticide applicators and their spouses, published in Environmental Health Perspectives, found about 2.5 times the odds of Parkinson’s disease among people who had used paraquat. The EPA says it has not found a clear link from labeled uses, and its paraquat page notes that a 2020 update from the Agricultural Health Study reported no association between paraquat and Parkinson’s disease.

Thousands of people have taken the question to court. The federal paraquat litigation, MDL 3004 in the Southern District of Illinois, had 8,495 cases filed and 6,602 still pending on October 1, 2026, and the parties signed a Master Settlement Agreement on September 3, 2025. Individual settlement amounts are not public. For the latest orders, see our paraquat litigation update.

SourcesTanner et al.2011EPA paraquat pageUpdated 13 Nov 2025JPML report1 Oct 2026CMO 248 Apr 2026

How to Show Your Paraquat Exposure: Records That Help

Paraquat exposure is easier to show when you can point to paper. Federal law requires that all private applicators are required by law to keep record(s) of their federally restricted use pesticide (RUP) applications for a period of 2 years, so recent application records may still exist with the farm, the applicator or a co-op. Records that often help include:

• Pesticide applicator licenses and paraquat training certificates, yours or your employer’s.
• Application records, spray logs and purchase receipts that name the product and dates.
• Employment, payroll or tax records that show where and when you worked.
• Photos of the farm, equipment or product labels, and names of co-workers who can describe the work.
• Medical records showing the diagnosis and when it was made.

You do not need every item to ask a question. A free paraquat case review starts with what you remember.

SourcesUSDA AMSCurrent pageEPA training pageUpdated 8 Jan 2026

Paraquat Exposure: Questions and Answers

Six common questions about paraquat exposure, each answered from the record.

Sources for This Paraquat Exposure Guide

Every statement on this page comes from one of these records.

• CDC, Paraquat fact sheet (updated June 10, 2026)
• NIOSH Pocket Guide to Chemical Hazards, Paraquat dichloride
• U.S. EPA, Paraquat Dichloride (updated November 13, 2025)
• U.S. EPA, action to prevent paraquat poisonings (December 15, 2016)
• U.S. EPA, paraquat certified applicator training (March 8, 2019)
• U.S. EPA, Paraquat Dichloride Training for Certified Applicators (updated January 8, 2026)
• U.S. EPA, review of potential paraquat volatilization (November 13, 2025)
• U.S. EPA science memo on paraquat volatilization (October 30, 2025)
• U.S. EPA news release on the paraquat roundtable and Data Call-In (June 30, 2026)
• U.S. EPA, Paraquat Interim Registration Review Decision (July 2021)
• Agricultural Health Study, About the Study
• Tanner CM et al., Environmental Health Perspectives (2011)
• USDA Agricultural Marketing Service, Pesticide Recordkeeping Program
• Judicial Panel on Multidistrict Litigation, Pending MDL Dockets (October 1, 2026)
• MDL 3004, Case Management Order No. 24
• California Department of Pesticide Regulation, paraquat cancellations (August 10, 2026)

How We Wrote This Guide

We started from the agencies that regulate and study paraquat: the EPA, the CDC and NIOSH, the USDA and the Agricultural Health Study. We added the court record for the litigation. We quote those documents directly, we do not estimate claim values, and dates on this page are the dates printed on each document. This guide was checked against its sources on October 5, 2026.

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