The following post from Purdue University’s turf program provides an update on Imprelis herbicide in a Question and Answer format.

Q: What action has the Office of Indiana State Chemist (OISC) recently taken concerning Imprelis®?

A: The OISC issued a stop sale, use, or removal order (SSURO) on August 1, 2011 for the herbicide Imprelis®. The OISC has reason to believe that DuPont Imprelis® Herbicide, EPA Reg. #352-793, when used as directed or in accordance with commonly recognized practice, has caused injury to non-target vegetation, except weeds to which it has been applied, and is therefore MISBRANDED. Therefore, the OISC is hereby issuing a STOP SALE, USE OR REMOVAL ORDER (SSURO) to DuPont Professional Products. This SSURO requires DuPont Professional Products to cease all sale, distribution and use of DuPont Imprelis® Herbicide, EPA Reg. #352-793, in the State of Indiana, effective immediately. This SSURO pertains to any and all quantities and sizes of DuPont Imprelis® Herbicide, EPA Reg. #352-793, within the ownership, control or custody of DuPont Professional Products wherever located. In addition, DuPont Professional Products shall not commence any movement of this product from any present location without prior written approval from the OISC. Any person violating the terms or provisions of this SSURO shall be subject to civil or criminal penalties as set forth in IC 15-16-4.

Q: What is the stance of the United States Environmental Protection Agency (EPA) concerning Imprelis®?
A: The EPA issued a letter to DuPont on August 3, 2011 stating two concerns. First, that the EPA is considering issuing an SSURO (described above). Second, the EPA is concerned about the lack of information that is being provided by DuPont to the public concerning the efficacy of Imprelis®. The EPA “strongly encourages DuPont to reconsider” providing information related to the phytotoxicity studies related to effects on trees. More information about Imprelis, including EPA registration of the herbicide, is available at:

Q: What action has DuPont taken to comply with the OISC?
A: DuPont is implementing a voluntary suspension of sale of Imprelis® herbicide. More information is available at and at (866) 796-4783.


Q: Can I still apply Imprelis® herbicide in Indiana if I have some leftover?
A: No. The SSURO issued by OISC does not allow the continued use of existing Imprelis® herbicide.
Q: What do I do if I have leftover Imprelis® herbicide?

A: DuPont has stated that they will initiate a product return and refund program in mid-August 2011. More details about this will be shared when they become available.

Q: Where can I get more information from DuPont about Imprelis®?
A: Website ( and hotline ((866) 796-4783) are available.

Q: Where can I get more information from Purdue and the OISC about Imprelis®?
A: Read news alerts from the Office of Indiana State Chemist at, read more from the Purdue University Turf Program at, and received updates from the Plant and Pest Diagnostic Laboratory at

Read past documents created on July 22, 2011
A Turf Professional’s Guide to Suspected Imprelis® Herbicide Injury in the Landsc

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