Anne Bredemann
Associate Editor
Loyola University Chicago School of Law, 2026
On August 6, 2024, the Environmental Protection Agency (EPA) resurrected its emergency authority for the first time in more than 40 years to prohibit the use of a common herbicide, dimethyl tetrachloroterephthalate (DCPA, or Dacthal) under the Federal Insecticide, Fungicide and Rodenticide Act (FIRFA) because of the chemical’s danger to human health. The last time the EPA exercised this power was in 1979, when the EPA banned the chemical weed killer Agent Orange which was known to cause serious birth defects and used by the United States military in the Vietnam War. The EPA has since remained reluctant to classify any other herbicide chemical as an imminent risk to the public health, until last month.
What’s wrong with Dacthal?
DCPA is a pesticide that has been widely used to control the growth of weeds on agricultural products like broccoli, Brussels sprouts, onions, strawberries, cotton, and beans, as well as on turfs and golf courses. The EPA warned in its summary from the Health Advisory for Dacthal and Dacthal Degradates (Tetrachloroterephthalic Acid and Monomethyl Tetrachloroterephthalic Acid) that traces of Dacthal may be found on food products and in the soil where it is used, and may also contaminate groundwater via runoff. Research from a 2019 study conducted by the Environmental Working Group showed that nearly 60% of kale samples tested by the Department of Agriculture indicated DCPA presence.
In the EPA’s announcement of its emergency order last month, they outlined the dangers to health associated with exposure to Dacthal, particularly for pregnant people. For example, unborn babies whose mothers who are exposed to DCPA “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.” Regulatory officials at both the state and federal levels have linked Dacthal to additional health problems, including liver and thyroid damage and cancer. The impact has been most notable for farming communities, particularly in the West, Southwest, and Midwest.
The history behind DCPA’s production
AMVAC Chemical Corporation is the sole manufacturer of Dacthal in the United States. The company failed to submit the complete set of required data for almost 10 years, including thyroid studies. In April of 2022, the EPA issued a notice of intent to suspend DCPA based on the company’s failure to provide the requisite data. When AMVAC finally cooperated by submitting the thyroid study in August of that year, the EPA subsequently held an administrative hearing and decided to suspend DCPA’s use registration. Just over a year later in November 2023, the EPA lifted the suspension, and only in March of 2024 did the EPA announce that they would pursue regulatory options for the chemical, such as further suspension of the registration or, as is now the case, an emergency suspension.
Environmental groups celebrated the move, but critics are noting that the agency’s ban has taken far too long realize. Unsurprisingly, The European Union took cautionary action regarding DCPA and banned the use of the chemical over 15 years ago, back in 2009. Additionally, the United States actually classified DCPA has a possible carcinogen as early as 1995, and states have taken action to ban its use locally as well. The concern among health and environmental advocates is why the EPA seems to struggle to prioritize Americans’ well-being over all else.
As of today, AMVAC Chemical could, under FIRFA, challenge the EPA’s findings and seek court review; however, the agency’s ban takes effect immediately while any appeal is considered. It is unlikely, however, that AMVAC will pursue an appeal since they did voluntarily submit registration cancellation requests with the EPA for their Dacthal products in compliance with the EPA’s ruling. Although production is banned, DCPA will unfortunately likely remain in the soil for years to come and will continue to affect most significantly people working in agricultural communities. While the current administration has made strides in environmental protection and safety, the federal government and EPA must push harder to prioritize the well-being of the American public and the health of the environment.