EPA Issues Emergency Order for Dacthal Pesticide Recall Due to Health Risks

The emergency order comes after EPA struggled for years to get data on the side effects of Dacthal on human thyroid function.

Federal regulators have made an extremely rare move, issuing an emergency order yesterday to pull the herbicide Dacthal from the market, due to the serious health risks it poses for pregnant women and developing fetuses.

Dacthal is the brand name of Dimethyl Tetrachloroterephthalate (DCPA), made by AMVAC Chemical, which is a weed killer often used on vegetables like broccoli and onions. It is also often used on turfs, such as golf courses and athletic fields. However, there have been concerns for years that side effects of Dacthal exposure could be linked to thyroid problems in unborn children.

Those concerns resulted in the U.S. Environmental Protection Agency (EPA) issuing its Emergency Order to suspend all registrations permitting Dacthal use on Tuesday. The order is effective immediately, banning Dacthal from the U.S. market.

“EPA has concerns that pregnant individuals may be currently exposed to DCPA at levels higher than those that cause fetal thyroid hormone disruption, but at which no thyroid effects would occur in the pregnant individual,” the emergency order states. “The downstream effects of such hormone perturbations in the fetus may include low birth weight and irreversible and life-long impacts to children exposed in-utero, such as impaired brain development and motor skills.”

EPA officials indicate this is the first time the agency has issued such an order in nearly 40 years. The European Union banned Dacthal use on crops in 2009.

According to the EPA, the U.S.’s decision came after the Biden Administration demanded long-overdue data on the weedkiller’s thyroid side effects. As early as 1999, the agency called for additional information after it was shown that Dacthal affected the thyroid function of rats.

AMVAC submitted some of the data in May 2021, but EPA officials said the report did not satisfy the agency’s data requirements. The agency issued a Notice of Intent to suspend Dacthal approval in April 2022, and the company finally submitted the data EPA requested that August.

After assessments earlier this year by the EPA, AMVAC and the agency discussed how to limit exposure to the chemical, with the manufacturer submitting proposals in April and May. However, even agreements to limit exposure in residential use were not enough to alleviate the risks, the EPA determined.

“DCPA is so dangerous that it needs to be removed from the market immediately,” EPA Assistant Administrator for the Office of Chemical Safety and Pollution Prevention, Michal Freedhoff, said in a press release on Tuesday. “It’s 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. That’s why for the first time in almost 40 years, EPA is using its emergency suspension authority to stop the use of a pesticide.”

The EPA determined that the Emergency Order was necessary to prevent harm to unborn babies that would have occurred during the time it took to go through the process of normal registration cancellation, officials indicated.

The order includes immediate cessation of use of Dacthal Flowable Herbicide, Dacthal W-75 Herbicide and Technical Chlorathal Dimethyl, all manufactured by AMVAC.