By KEVIN WALKER
Michigan Correspondent
 
WASHINGTON, D.C. — The U.S. Environmental Protection Agency (EPA) issued an order earlier this month stopping the sale of Imprelis, a new herbicide used on turfgrass.

It’s believed the herbicide, when applied to turf, may be taken up by certain trees, which are then injured or killed. That isn’t how the chemistry is supposed to work, and there’s been no warning against its use near trees.

The Stop Sale letter, dated Aug. 11, took effect immediately. The letter was issued under the authority of FIFRA – the Federal Insecticide, Fungicide and Rodenticide Act.

Imprelis, which is made by DuPont, was approved for use as a broadleaf weed herbicide on Aug. 31, 2010. It was intended for use by lawn care professionals, not homeowners, according to Michigan State University research scientist and extension specialist Bert Cregg. But the chemical has been applied to residential lawns as well as golf course turf.

According to Cregg, the most commonly affected trees are Norway spruce, Colorado blue spruce and eastern white pine. Other conifers and some hardwood trees also may be affected.

According to the Stop Sale letter, beginning in June, the EPA started receiving complaints from numerous states reporting damage to trees associated with the use of Imprelis. On July 18, the EPA sent a letter to DuPont requiring the company to provide the agency with more information about Imprelis. On July 28 DuPont sent information to the EPA which included thousands of reports of “adverse incidents” involving Imprelis, including damage or death to trees.
In its Stop Sale letter the EPA writes that Imprelis is “misbranded” because the label for the product doesn’t warn users about potential damage to trees. Because of the many complaints from users, on Aug. 4 DuPont sent its distributors a letter indicating it was suspending sales of Imprelis voluntarily and would institute a product return and refund program. That was followed by the EPA’s Stop Sale letter of Aug. 11.

“We intend to start the product return and refund program in mid-August,” the letter to distributors reads. “We will be contacting you soon with additional details about how to collect the product from your customers and return it to DuPont.

“We will also be letting you know what records of the returns you will need to keep as part of the process, what your customers will need to do and how you will be credited for the returned product. This notice covers full and partial containers, and all pack sizes of Imprelis.”

Cregg said for users of Imprelis it has been a major disruption of their business.
“They have spent a good bit of their summer dealing with complaints and working on damage control,” he said. “One applicator in Michigan had over 400 properties affected. They have one person in their office that does nothing but manage files documenting affected properties.

“For growers that didn’t apply Imprelis there could be some indirect effects, since this incident may make chemical companies less likely to try to introduce new products for this market.”

Cregg said he doesn’t know how this could have happened. “At this point all we have is speculation,” he said. “The product underwent years of testing, both in-house at DuPont as well as through universities. My understanding is that it was tested on conifers, but how and which ones, I don’t know. “I’m sure this will be the subject of scrutiny by EPA and in litigation. In any event, it seems clear that somehow the test conditions did not reflect how the product was used, when applied by the label.”

Cregg said there have been reports of homeowners who had trees damaged but didn’t use Imprelis, but a neighbor did. Cregg and his colleague, Kevin Frank, have written instructional articles on Imprelis developments, such as how to document losses from Imprelis. These are available at www.news.msue.msu.edu by clicking on “Turf & Landscape.”
DuPont did not return a telephone call for comment, but there are more details on its website, www.imprelis-facts.com

The company has also set up a hotline for anyone who’s had trees that might have been damaged by Imprelis. That number is 866-796-4783.