Dacthal (DCPA): Health and Legal Concerns

Dacthal, also known as dimethyl tetrachloroterephthalate (DCPA), was an herbicide used to control weeds in both agricultural and non-farming settings. The United States Environmental Protection Agency (EPA) banned Dacthal and took it off the market in 2024.

Dacthal was a “pre-emergent herbicide,” meaning users applied it to the ground before weed seeds germinated. It helped manage unwanted plants, like certain grasses and broadleaf weeds. People commonly used it on lawns, flowers, strawberries, young plants, cotton, field beans and vegetables grown from seeds.

However, Dacthal received significant attention from regulators because of concerns about its potential health and environmental risks.

In response to these risks, the EPA issued an emergency suspension in August 2024, halting all use, sale, distribution and transport of DCPA products.

There have been no studies on people exposed to Dacthal, but animal studies suggested that DCPA may pose several serious human health risks.

The EPA relied on animal studies to assess Dacthal’s health risks when deciding to ban the chemical in the United States. Documents from the EPA and various state health and environmental agencies list several potential health effects from DCPA.

In animal studies, researchers found that Dacthal had low short-term toxicity, meaning it didn’t cause many immediate health issues, even in high doses. However, it could cause mild irritation to the eyes and skin if inhaled or touched.

On the other hand, being around Dacthal for an extended period could increase the chances of more serious health problems.

One of the EPA’s reasons for banning Dacthal was the manufacturer’s failure to provide more than 20 internal safety studies to the agency in a timely manner. In some cases, the manufacturer — AMVAC Chemical Corporation — withheld requested documents for nearly 10 years.

In an October 2024 statement, the EPA noted that AMVAC had missed the deadline by more than six years for a crucial study about the chemical’s impact on the thyroid health of pregnant people and their unborn babies. Once the EPA finally received this study, its “assessment found health risks associated with DCPA use and application,” and that these risks were most profound for unborn babies.

Due to these health risks and the long delays in receiving information from AMVAC, the EPA suspended Dacthal’s use.

“DCPA is so dangerous that it needs to be removed from the market immediately,” EPA Assistant Administrator Michal Freedhoff said in a statement. “It’s the EPA’s job to protect people from exposure to dangerous chemicals. In this case, pregnant women who may never even know they were exposed could give birth to babies that experience irreversible lifelong health problems.”

After the EPA’s action, AMVAC stopped selling the product in the U.S. and other countries.

European Union and Australian Dacthal Bans

The European Union banned Dacthal in 2009, 15 years ahead of the EPA’s decision.

Australia banned Dacthal shortly after the United States in 2024 for fear that it could cause birth defects. Australian regulators cited the same long-delayed thyroid hormone study that the EPA waited nearly 10 years to receive from AMVAC.

The study showed that even low levels of Dacthal can affect thyroid hormones that are important for brain and body development before birth.

After the EPA decided to ban DCPA, many people in the U.S. started to file Dacthal lawsuits claiming that the chemical caused health issues. Lawyers are looking into stories from those who believe DCPA led to serious injuries, particularly in babies whose mothers experienced Dacthal exposure before giving birth.

People can receive exposure to Dacthal in different ways, such as by using the chemical directly, working on farms that use it or even living near those farms. If you experienced health issues due to DCPA exposure, you might be able to receive financial compensation for medical expenses and other related costs.

Dacthal lawsuits are in the early stages, and there haven’t been any significant trials or settlements yet.

There are several steps you can take if you believe Dacthal exposure caused your health problems, either as an agricultural worker or as someone who lived near fields where farmers applied the herbicide. These steps include testing your drinking water, documenting where your DCPA exposure may have occurred, tracking any potentially Dacthal-related injuries and talking with an attorney.

Document Potential Exposure

If you worked with crops commonly treated with DCPA — or lived near farms with Dacthal-treated crops — you should gather evidence of when you worked or lived there.

No medical tests can tell if you have Dacthal exposure. However, even though Dacthal usually stays in the soil, it can enter your drinking water supply due to runoff or rain. Dacthal eventually breaks down into tetrachloroterephthalic acid (TPA) and monomethyl tetrachloroterephthalic acid (MTP), which can move through water more easily than DCPA.

Some public water utilities have discovered these Dacthal byproducts in their supplies, and in some cases, the levels have reached as high as 190 micrograms for every liter of water. For reference, some states’ drinking water guidelines limit Dacthal levels to 2 micrograms per liter or less.

If you suspect you received Dacthal exposure through your drinking water, you can have it tested for DCPA, MTP and TPA.

Document injuries you or your child have suffered that could have links to Dacthal exposure, including children born with low birth weight and developmental problems.

Finally, talk with an environmental product liability attorney. These are lawyers who specialize in this type of case. Pesticide lawsuits are complex cases that require lawyers who can bring together scientific and medical experts — along with their own experience — in cases against large chemical manufacturers. Many may have experience with similar Paraquat or Roundup lawsuits.

Drugwatch partners with leading national law firms with this kind of expertise and can help you find the attorney best suited to your individual needs. These attorneys can help you determine if you have a case and the next steps to take.