Aug 8, 2024

EPA issues emergency stop to Dacthal herbicide use

The Environmental Protection Agency (EPA) is halting the use of the herbicide Dacthal with an emergency order to stop application. Also known as dimethyl tetrachloroterephthalate (DCPA), Dacthal is a pesticide registered to control weeds in both agricultural and non-agricultural settings.

Effective immediately, no person or business in any state may use, distribute, sell, offer for sale, hold for sale, ship, deliver for shipment, or receive and (having so received) deliver or offer to deliver to any person any pesticide product containing DCPA.

This federal action is directed to the public in general and may be of interest to a wide range of stakeholders including environmental, human health, farm worker and agricultural advocates; the chemical industry; pesticide users; and members of the public interested in the sale, distribution or use of pesticides.

The EPA has elected not to permit the continued use of existing stocks, consistent with its policies regarding cancellations where the federal agency has identified significant risk concerns. EPA will allow continued distribution of existing stocks of DCPA for the express purpose of returning any DCPA product to the registrant of such products. EPA intends to issue a notice of intent to cancel the same DCPA products within the next 90 days.

Pesticide Products Subject to Order

Dacthal Flowable Herbicide; EPA Reg. No. 5481-487; Registrant: AMVAC
Dacthal W-75 Herbicide; EPA Reg. No. WI050002; Registrant: AMVAC
Technical Chlorthal Dimethyl; EPA Reg. No. 5481-495; Registrant: AMVAC

“The Environmental Protection Agency (EPA), after scheduled reregistration reviews, may cancel a product’s registration or a specific use pattern when they identify new risks associated with the use of those products,” said John Scott, Colorado Department of Agriculture’s Pesticides Program Section chief. “The immediate cancellation of all distribution and all end uses reflects the seriousness of their findings in this Emergency Order.”

In May 2023, an occupational and residential exposure (ORE) assessment was conducted based on the two DCPA end-use products registered at that time. Risks of concern were identified for multiple scenarios, including occupational scenarios (handler and post-application), residential post-application scenarios, and non-occupational post-application bystander spray drift scenarios.

Read the Federal Order halting its use here.

If you have questions regarding this action, please contact the Colorado Pesticide Program through the Division of Plant Industry for more information at PesticidesProgram@state.co.us or 303-869-9050.