Chlorpyrifos: Pesticide Dangers, Bans and Parkinson’s Disease Lawsuits

Chlorpyrifos is an organophosphate that first entered the market in 1965. Originally manufactured by Dow AgroSciences, it’s now part of Corteva. The toxic pesticide can kill everything from termites and roundworms to weevils and mosquitoes.

At one time, people used chlorpyrifos to eradicate pests in homes and on farms. Today, farmers still use the chemical on 11 specific food crops. It also has a few non-food uses, such as on golf courses or in residential ant and roach bait.

Chlorpyrifos works by causing a buildup of the neurotransmitter acetylcholine in the nerve endings, overstimulating the neurons. Eventually, this leads to neurotoxicity and death in insects.

But bugs aren’t the only susceptible organisms, as the pesticide could also cause brain and neurodevelopmental issues in humans. People who accidentally inhale or ingest high doses of chlorpyrifos may develop neurotoxicity, which can manifest with symptoms such as nausea, dizziness and confusion. Extremely high exposures to the chemical can lead to respiratory paralysis and death.

The controversial chemical has links to developmental problems and low IQs in children, along with Parkinson’s disease in adults.

In 2021, the U.S. Environmental Protection Agency (EPA) banned chlorpyrifos on food crops. However, a federal appeals court reversed that rule in 2023. The EPA later restricted chlorpyrifos use to 11 food and feed crops: Alfalfa, apples, asparagus, tart cherries, citrus, cotton, peaches, soybeans, strawberries, sugar beets and wheat. Today, the EPA’s review of chlorpyrifos use continues, and it plans to release an amended proposal in 2026 before issuing a decision on the pesticide’s future uses.

Some states have issued chlorpyrifos bans. For example, California and Hawaii have ended agricultural chlorpyrifos use. Check your state’s pesticide agency for the latest restrictions.

The risks of Parkinson’s disease in adults and developmental delays in children have led some people to file lawsuits against chlorpyrifos manufacturers. These cases claim that long-term occupational exposure or exposure during pregnancy can lead to health conditions and that manufacturers failed to warn about the risks.

Even though the U.S. government limits indoor use of chlorpyrifos to insect bait traps, people can still be exposed to the chemical in other ways. If you live near an agricultural area, chlorpyrifos dust can drift from nearby fields into your home, school or office.

Bonnie Wirtz and her family experienced exposure to toxic levels of chlorpyrifos in 2012, when a crop duster flying overhead sprayed a farm adjacent to their Minnesota home. Wirtz said that after the airplane deposited the chemicals, a white mist started coming through their air-conditioning unit, and she began coughing, stumbling and having trouble breathing.

Wirtz’s husband rushed her and their 8-month-old baby to the emergency room, where they learned that chlorpyrifos had caused their illnesses. Air samples later revealed chlorpyrifos levels four times higher than the safe exposure limits for a one-year-old child. Doctors later diagnosed Wirtz’s son with a neurodevelopmental disorder.

Farm workers have also experienced chlorpyrifos poisoning. In May 2017, a group of cabbage field workers fell ill after a cloud of chlorpyrifos drifted over from a nearby mandarin orange grove. Workers could taste the strong odor of the chemical in their throats as symptoms such as tingling lips, itchy skin, watery eyes and headache overtook them.

While some workers scattered to find relief from the chemical, others were too afraid to walk off the job. Those who stayed developed nausea, vomiting, dizziness and other symptoms. Some workers fainted, and others collapsed into convulsions. Rescuers came and set up a decontamination area several hundred yards away and shuttled the poisoning victims to an area hospital.

Pesticide Residue in Food

Fruits and vegetables that we buy and eat may also contain chlorpyrifos residue. According to the U.S. Department of Agriculture’s (USDA) 2024 Pesticide Data Program, the agency detected chlorpyrifos in 36 of 9,165 fruit and vegetable samples tested, including avocados, fresh blackberries, cucumbers, head lettuce, fresh sweet corn and tomatillos. Of all foods tested, 1.8% of tomatillos, 1.3% of fresh sweet corn and 1.1% of cucumbers had chlorpyrifos residue.

Finding residue doesn’t automatically mean food is unsafe. In its report, the EPA said pesticide residues in food are usually below the maximum allowable amount to remain in or on food. In 2024, more than 99% of the foods tested had residues below the established EPA limits, and 42.3% had no detectable residue.

However, researchers continue to study whether chlorpyrifos exposure during pregnancy and childhood may affect the developing brain.

Exposure to small amounts of chlorpyrifos can cause a runny nose, tearing of the eyes, excessive salivation, drooling, headaches, sweating, dizziness and nausea. As exposure levels increase, an individual may develop vomiting, abdominal cramping, tremors, weakness, muscle twitching, loss of coordination, diarrhea and vision impairment. Severe poisoning can cause a loss of bladder and bowel control, unconsciousness, trouble breathing, convulsions and paralysis.

In children, some research has linked chlorpyrifos to developmental delays, brain defects and developmental disorders, including autism. Studies have also linked long-term chlorpyrifos exposure with an increased risk of developing Parkinson’s disease. A 2025 study in Molecular Neurodegeneration found people exposed to chlorpyrifos had more than 2.5 times the risk of developing Parkinson’s disease compared to people who didn’t experience exposure.

Adults who received a Parkinson’s disease diagnosis after long-term occupational exposure may be eligible to file chlorpyrifos lawsuits. Additionally, children who developed developmental disorders after exposure to chlorpyrifos in the womb or in the first four years of life may also qualify.

According to lawsuits, manufacturers knew or should have known that chlorpyrifos was dangerous but failed to warn the public. Due to the serious health risks and the fact that safer alternatives exist, plaintiffs say manufacturers defectively designed the pesticide.

Litigation is in the early stages, and there have been no global settlements. Attorneys are still filing these cases individually in state courts.

Because of its widespread use, it’s difficult to avoid chlorpyrifos, but eating organic fruits and vegetables may help.

A 2019 study in Environmental Research found lower levels of pesticides, including chlorpyrifos, in people’s urine after they switched to an organic diet. The researchers also concluded that chlorpyrifos food residue “would likely decrease” if the EPA bans its agricultural use.

If you work with any products that contain chlorpyrifos, wear proper personal protective equipment at all times. According to the EPA, this includes chemical-resistant gloves, coveralls and respirators. People without protection should not enter treated fields for 24 hours to five days after receiving treatment.