The U.S. Environmental Protection Agency (EPA) invoked emergency action on August 7th to remove Dacthal from the market including existing inventory. This is the first time in 40 years that the EPA has issued an emergency recall, preferring negotiated settlements with imposition of stricter labeling and other mitigation measures.
The active ingredient of the herbicide is dimethyl tetrachloroterephthalate (DCPA) shown to be teratogenic. The compound has been used since 1958 to control weeds in the cultivation of broccoli, cabbage and onions and for application to turf grasses. Dacthal is only manufactured by Amvac Chemical Corporation. This Company was unable to provide data on health risks that were identified in 1990 by an advocacy group.
Dr. Michael Freedhoff, Assistant Administrator for the EPA Office of Chemical Safety and Pollution Prevention noted, “DCPA is so dangerous that it needs to be removed from the market immediately.” Teratogenic effects include low birth weight and impaired brain development including learning ability and motor skills in children exposed in utero. Given that teratogenicity and interference with thyroid function was confirmed in 1990 why did the EPA take this sudden action after 34 years?
This belated action by EPA will protect female field workers who have been exposed to levels of DCPA estimated to be 20 times higher than the level considered to be safe for fetuses even when using personal protective equipment.
Banning of Dacthal suggests that similar action is intended for commercial products containing chlorpyrifos following a state ban in California.