The U.S. Environmental Protection Agency today announced the emergency suspension of all registrations of a pesticide known by the brand name, Dacthal, effective immediately.

Dacthal, or dimethyl tetrachloroterephthalate (DCPA), which is used to control weeds, has been suspended under the Federal Insecticide, Fungicide and Rodenticide Act, the EPA said.

The rare emergency action was taken, the EPA said, to protect unborn babies.

“DCPA is so dangerous that it needs to be removed from the market immediately,” said Michal Freedhoff, assistant administrator for EPA’s Office of Chemical Safety and Pollution Prevention, in a news release. “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.”

Freedhoff said this is why for the first time in almost 40 years, EPA is using its emergency suspension authority to stop the use of the pesticide.

Pregnant mothers exposed to Dacthal — sometimes unknowingly — could experience changes to fetal thyroid hormone levels, the EPA said, which 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.

The Hawaii Department of Agriculture said in response, its Pesticides Branch today began notifying retailers registered to import and sell the product in the state of the EPA suspension.

One pesticide producting containing DCPA as the active ingredient, DACTHAL FLOWABLE HERBICIDE, is licensed in Hawaii.

HDOA said preliminary responses from retailers indicate there have not been sales of the product in Hawaii for several years.

According to the EPA, DCPA is a pesticide registered to control weeds in both agricultural and non-agricultural settings, but is primarily used on crops such as broccoli, Brussels sprouts, cabbage and onions. AMVAC Chemical Corporation is the sole manufacturer of DCPA.

Last May, the EPA determined in an assessment that there were health risks associated with DCPA use, even with personal protective equipment and engineering controls in place. The EPA intends to issue a notice of intent to cancel the DCPA products within the next 90 days.

“This emergency order, while rare, underscores the importance of proper disposal of all pesticides,” said HDOA in its news release.

Anyone with questions regarding DCPA products and the proper disposal of pesticides in Hawaii should contact the Pesticides Branch at 808-973-9402 or hdoa.pested@hawaii.gov.