An herbicide used to control weeds on a variety of crops for decades was banned Tuesday under an emergency order by the U.S. Environmental Protection Agency. The risk to unborn babies was too high for the agency to wait, it said.
The order to control Dacthal, or dimethyl tetrachloroterephthalate, is the first action of its kind the EPA has taken in nearly 40 years, it said in a press release. Studies found pregnant mothers exposed to the chemical can have children with low birth weight, diminished brain development and IQs, and challenged motor skills from changes in fetal thyroid hormone levels, along with impaired thyroid development.
The USDA approved Dacthal in 1960 for use on a wide range of crops including strawberries, broccoli, onions, Brussels sprouts and cabbage, in addition to use on lawns for controlling weeds like hard-to-remove crabgrass.
It has been used in Maine for strawberry management, and testing by the state’s board of pesticide control found it in groundwater near a strawberry farm 19 years ago.
The board of pesticide control could not be reached for more information Tuesday.
In reviewing registration for the chemical, a standard 15-year process, the EPA said required studies from the manufacturer about the product’s effects on thyroid health in children and adults were insufficient or not turned in at all.
The agency’s research found fields where the chemical has been applied may be unsafe for pregnant women for 25 days afterward. Pregnant women handling the chemicals, even with protective equipment, could be exposed to levels of Dacthal four to 20 times more than the EPA’s safety estimate for unborn babies.
Tuesday’s order follows an April public health warning about the chemical and an August 2023 suspension of the product registration.
