Imprelis was registered with the United States Environmental Protection Agency[3] for sale in October 2010.[4] Sale of Imprelis was voluntarily suspended[5] a week before the EPA required sales stopped.[6][4] DuPont acknowledged it was killing or damaging evergreen trees, including white pine and Norway spruce.[7] DuPont allegedly knew Imprelis would damage evergreens before seeking EPA approval.[8]