Imprelis Treated Grass Clippings Not Fit to MulchAug 17, 2011 | Parker Waichman LLP
Gardeners who compost might want to make sure any grass clippings they mulch haven't been treated with DuPont's Imprelis herbicide. According to a warning from the Minnesota Department of Agriculture, such grass clippings may contain enough Imprelis to cause damage to trees.
“Homeowners should not spread Imprelis-treated grass clippings near trees, other ornamental plants or gardens," Pesticide and Fertilizer Division Director Greg Buzicky said in a posting on the Department's website. “If clippings are not left on the lawn, they can be disposed of in the trash, but only where allowed by local yard waste regulations. Clippings should not be added to garden compost or collected for composting facilities.”
Last Thursday, the Environmental Protection Agency (EPA) officially issued DuPont a Stop Sale, Use or Removal Order (SSURO) after data provided by DuPont confirmed that certain coniferous trees, including Norway spruce, white pine and balsam fir, were susceptible to being damaged or killed by the application of Imprelis. A week prior, DuPont had announced it would voluntarily stop selling Imprelis, and establish a recall and return program for its customers.
DuPont and the EPA had both begun Imprelis investigations earlier this summer, after receiving reports that evergreen trees had been damaged, and in some cases killed, after Imprelis was applied to nearby lawns. Reported symptoms included twisting and curling, possibly followed by browning of needles, shoots and branch tips. While most damage reports involve coniferous trees, such as white pine and Norway spruce, injury has also been seen on other ornamental plants and deciduous trees, according to the Minnesota Department of Agriculture.
Imprelis, which DuPont began marketing last year, was supposed to be an environmentally safe solution for controlling broadleaf weeds. It was not sold over the counter, but was only available to licensed landscapers.
At least 18 Imprelis lawsuits are pending in federal courts in Delaware, Indiana, Iowa, Kansas, Minnesota, New Jersey, Ohio, Pennsylvania, Utah and Wisconsin. The Judicial Panel on Multidistrict Litigation announced yesterday that it will convene a hearing on September to consider consolidation of Imprelis lawsuits to a single case.