EPA issues stop sale order to DuPont’s Imprelis herbicide

The U.S. Environmental Protection Agency (EPA) issued an order to E.I. DuPont de Nemours (DuPont) directing the company to immediately halt the sale, use or distribution of Imprelis (active ingredient: aminocyclopyrachlor), an herbicide marketed to control weeds that has been reported to be harming a large number of trees, including Norway spruce and white pine. The order, issued under the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA), requires DuPont to stop the sale and distribution of Imprelis in the U.S. and outlines specific conditions to ensure that the removal of Imprelis from the market meets legal requirements.

This action follows EPA's investigation into why a large number of evergreens and other trees have been harmed following the use of the herbicide. In its evaluation, EPA is investigating whether these incidents are the result of product misuse, inadequate warnings and use directions on the product's label, persistence in soil and plant material, uptake of the product through the root systems and absorbed into the plant tissue, environmental factors, potential runoff issues or other possible causes. 

On June 17, 2011, DuPont issued a letter to professional applicators cautioning against the use of Imprelis where Norway spruce or white pine trees are present on, or in close proximity to, the property being treated. On July 27, 2011, DuPont acknowledged to the EPA that there has been damage to trees associated with Imprelis use and the company had developed an internet web page to provide information and updates concerning Imprelis use.

On August 4, 2011, DuPont voluntarily suspended sales of Imprelis and announced that it will soon conduct a product return and refund program.