Written collaboratively by Stephen Robertson; Amanda Bachmann; Eric Jones; Kristine Lang; and Rhoda Burrows, former Professor & SDSU Extension Horticulture Specialist.
Following a review of data associated with the use of dimethyl tetrachloroterephthalate (abbreviated as DCPA), sold under the most-common trade name Dacthal, the U.S. Environmental Protection Agency (abbreviated as EPA) has issued an emergency order to stop using this active ingredient effective immediately.
DCPA is an organic herbicide commonly applied as a preemergent to control annual grasses and many common weed species in both agricultural and non-agricultural settings. DCPA works by inhibiting root growth in susceptible plants and is safe to use on several crops that are sensitive to other types of herbicides (such as flowers, fruits, and vegetables) in which it is most commonly used.
The only DCPA product currently registered in South Dakota is Dacthal Flowable Herbicide. If you possess any amount of this herbicide, stop using it immediately, store it as specified by the existing label, and await further instructions.
For more information about this emergency order, view the official EPA news release.
