April 4, 2024

Herbicide Dacthal Poses “Significant Health Risks” to Pregnant People, EPA Warns

On April 1, EPA issued a warning that the herbicide dimethyl tetrachloroterephthalate, also known as DCPA or by the trade name Dacthal, presents “significant health risks to pregnant individuals and their developing babies.” The agency also issued a letter to AMVAC, the manufacturer of DCPA, that restates the chemical’s health risks and notifies the company of EPA’s intent to protect workers and others exposed to it. Due to the health risks associated with DCPA, EPA is considering further action under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA).

DCPA is registered for use in controlling weeds in agricultural and non-agricultural settings, but its primary use is on crops including broccoli, Brussels sprouts, cabbage, and onions, EPA’s press release explains. In 2023, the agency released a risk assessment on DCPA as part of the registration review process, which requires reevaluation of pesticides every 15 years. This risk assessment determined that pregnant people exposed to the herbicide could experience changes in thyroid hormone levels linked to low birth weight, decreased IQ, and impaired motor skills in their developing babies. Health risks persisted even after engineering controls and personal protective equipment were used. Pregnant people and their developing babies may be at risk when entering or working in areas where DCPA has been applied, including golf courses and athletic fields. Unsafe levels of DCPA may remain for more than 25 days after treatment, EPA found.

In 2023, EPA suspended the registration for the DCPA technical-grade product, which is used to manufacture end-use products, citing the manufacturer’s failure to submit requested data on the chemical’s health effects for almost 10 years. EPA rescinded the suspension following AMVAC’s provision of the requested documents, and the company voluntarily cancelled the use of DCPA on turf in December 2023. However, “unacceptable risks from agricultural use remained,” states EPA.

“When serious risks are identified, EPA can take action under FIFRA to suspend or cancel a pesticide,” the agency notes. “EPA is considering these tools as it moves forward with the DCPA registration review, but in light of the serious risks posed by DCPA, chose to warn the public of them at this time as it continues its work.”

More information may be found in EPA’s press release. Documents related to EPA’s actions on DCPA are available in the docket on Regulations.gov.