EPA’s conditional registration of Aminocyclopyrachlor and Clothianidin illustrates the dangers of approving a pesticide before completing a comprehensive appraisal of its risks
The agribusiness conglomerate DuPont has received more than 30,000 damage claims arising from its sale of a pesticide that resulted in death and injury to hundreds of thousands of evergreen trees, particularly Norway spruce and white pine. DuPont marketed the pesticide, sold under the trade name Imprelis, based on a conditional registration that the U.S. Environmental Protection Agency (EPA) granted in 2010. The active ingredient in Imprelis, aminocyclopyrachlor, is biologically active in soil and rapidly absorbed by roots and leaves. Aminocyclopyrachlor is in the chemical class of the pyrimidine carboxylic acids, which is similar to pyridine carboxylic acid herbicides that includes the herbicides aminopyralid, clopyralid and picloram. The two classes of herbicides share characteristics, including high persistence in the environment, systemic incorporation into plants and high toxicity during seedling emergence. Conditional registration is allowed under Section 3(c)(7) of the Federal Insecticide, Fungicide and Rodenticide Act prior to the registrant submitting all statutorily required data. EPA is authorized to grant a conditional registration on the assumption that no unreasonable adverse effects on environmental and human health will result.