Dacthal (DCPA)

Dacthal, also known as dimethyl tetrachloroterephthalate or DCPA, is a pre-emergent herbicide. This means it’s applied to the soil before weeds and grasses can sprout, effectively controlling unwanted plants in various crop fields and ornamental gardens. Recent concerns about its health impact, particularly its association with birth defects, have brought Dacthal under scrutiny.

Dacthal is a widely used pesticide that was first registered by the U.S. Environmental Protection Agency (EPA) in 1958 and used on vegetables like broccoli, Brussels sprouts, cabbage and onions, as well as on turf and strawberries. Primarily, Dacthal inhibits the normal cell division of weed roots, preventing their growth.

However, Dacthal has raised significant health concerns, particularly for pregnant farmworkers. Studies have shown that exposure to this herbicide can cause severe health issues, according to the EPA.

The EPA said that Dacthal exposure can cause low birth weight and impaired brain development in babies, leading to long-term developmental issues. In response to these risks — and delays by the manufacturer to supply requested safety research — the EPA issued an emergency order in August 2024, suspending all sales and use of Dacthal to prevent further harm.

Where Was Dacthal Used?

Dacthal (DCPA) was a widely used herbicide for various crops, particularly in California and Washington State.

Key agricultural regions had particularly concentrated Dacthal levels, making localized exposure more prevalent.

Dacthal was most commonly applied to cruciferous vegetables like broccoli and Brussels sprouts and to allium crops such as onions and leeks. People who worked with these vegetables in the field, at packing plants or as produce sellers may have been exposed.

If you experienced Dacthal exposure while pregnant, particularly on farms or in facilities where it was applied, it’s important to understand the potential risks and take appropriate action.

Dacthal has been banned by the EPA due to its substantial health risks, especially the birth defects observed in children whose parents were exposed to the herbicide during pregnancy.

“The EPA’s ban, though overdue, reflects a step toward protecting communities,” Steve Rosas, an environmental consultant with Omega Environmental, told Drugwatch. “Farmers have alternative herbicides and non-chemical tactics, so transitioning from Dacthal, while inconvenient, is doable and necessary.”

According to the EPA, they banned Dacthal “because unborn babies whose pregnant mothers are exposed to DCPA, sometimes without even knowing the exposure has occurred, could experience changes to fetal thyroid hormone levels, and these changes are generally linked to low birth weight, impaired brain development, decreased IQ, and impaired motor skills later in life, some of which may be irreversible.”

These risks prompted the EPA, in August 2024, to issue an emergency suspension of the pesticide’s use to protect the health of pregnant people and their babies.

Dacthal had been under review by the EPA for years, with the agency requesting safety data from its manufacturer, AMVAC Chemical Corporation. Despite the EPA’s efforts, AMVAC delayed submitting the required studies, which ultimately led to the emergency action.

Dacthal can pose significant health risks when it contaminates water or comes into direct contact with skin, according to several regulatory agencies. Farmworkers and nearby residents are particularly at risk when Dacthal contaminates water or comes into direct contact with skin. Even at low exposure levels, state and federal regulators have linked Dacthal to severe health problems beyond congenital disabilities, including liver and thyroid damage and cancer.

“Dacthal appears especially prone to contaminating water and soil, where it may persist for years,” Rosas said. “Compared to other pesticides, Dacthal seems particularly likely to disrupt fetal development by interfering with thyroid hormone levels critical for growth.”

Dacthal breaks down into chemicals like TPA (tetrachloroterephthalic acid) and MTP (monomethyl tetrachloroterephthalic acid), which are more soluble in water and can leach into groundwater. These breakdown products can spread contamination, increasing the risk of exposure for people living near areas where Dacthal is applied to crops.

There is no specific treatment for Dacthal poisoning, making preventative measures crucial. Before its ban, regulators warned people to wear protective gear when handling Dacthal. If you live near farms that commonly made use of the herbicide, you may want to consider testing your water supplies.

If you believe you had Dacthal exposure during pregnancy, it’s crucial to consult with healthcare providers and legal professionals to understand your options.

People in certain regions might file Dacthal lawsuits over birth defects due to exposure to the herbicide. If a pregnant person experienced Dacthal exposure, either through working with the pesticide or living within a mile of an area where Dacthal was used, they might face higher risks of having a child with birth defects.

Dacthal lawsuits can help families secure compensation for health issues linked to Dacthal exposure. Affected people typically pursue lawsuits to address herbicide-related birth defects and to hold the manufacturer — AMVAC Chemical — accountable.

Dacthal lawsuits not only seek compensation but also aim to secure the necessary medical care for children who may face lifelong challenges due to Dacthal-related birth defects.

If you were around Dacthal when you were pregnant, it’s important to act fast to protect you and your baby’s health. First, talk to a doctor to check for any potential health problems for you and your baby. Your doctor can help you get the medical tests and monitoring you need to find any early signs of issues, like birth defects or developmental problems.

Additionally, consider talking to a lawyer who specializes in toxic exposure or birth defect cases. Lawyers can help you understand your rights and figure out if you can take legal action against the company that makes Dacthal. Taking legal action could earn you money to help cover your medical costs and other expenses from being around Dacthal.

Finally, stay in the know about your local area, especially if it was an area with high Dacthal use. If you’re worried about still being around Dacthal, have your water and soil tested to ensure your home is safe.

“Overall, we must reevaluate pesticide use and advance safer practices in agriculture and beyond. Though an inconvenience, transitioning to safer alternatives will build a sustainable future for all,” Rosas said.

Editor Lindsay Donaldson contributed to this article.