EPA directs suspension of all uses of AMVAC’s Dacthal herbicide

The Environmental Protection Agency is issuing an Emergency Order directing the suspension of all registrations issued under the Federal Insecticide, Fungicide, and Rodenticide Act for pesticide products containing the active ingredient dimethyl tetrachloroterephthalate, also marketed under the trade name Dacthal. EPA has determined that continued sale, distribution, or use of DCPA products during the time required to cancel such products would pose an imminent hazard and that an emergency exists that does not permit EPA to hold a hearing before suspending such products. These determinations are based primarily on a risk of thyroid hormone perturbations in the fetuses of female bystanders and workers who apply DCPA or who enter treated fields after application. EPA has concerns that pregnant individuals may be currently exposed to DCPA at levels higher than those that cause fetal thyroid hormone disruption, but at which no thyroid effects would occur in the pregnant individual. The downstream effects of such hormone perturbations in the fetus may include low birth weight and irreversible and life-long impacts to children exposed in-utero, such as impaired brain development and motor skills. While the sole registrant of DCPA products, AMVAC Chemical Corporation, has attempted to address these concerns, EPA has determined that there is no combination of practicable mitigations under which DCPA use can continue without presenting an imminent hazard. Set forth below are the substantive bases for these determinations and the procedures that affected registrants must follow to obtain a hearing on or otherwise challenge these determinations. Shares of American Vanguard, the parent compact of AMVAC Chemical, are down over 14% in after-hours trading.