UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON D
.C ., 20460 OFFICE OF CHEMICAL SAFETY AND POLLUTION PREVENTION PC Code 128887 

### OP Barcode 404864 Date September 26, 2012 M EMORANDUM SUBJECT:

FROM: Review of two reports (MRIDs 48904003 and 48904004) as the Response to a Data Call-In (DCI) for an Environmental Chemistry Method (ECM) and an Independent Laborator y Validation ( ILV) for Tribenuron-Methyl
James Lin , Environmental Engineer



### ~ Environmental Risk Branch 2 Environmental Fate and Effects Division ./) ,...., ./ J

**·** I o..
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_ }2.. REVIEWERS: Greg Orrick, Envi ronmental Scientist

**~ U~**  1 t?- 0 Environmental Risk Branch 2

THRO UG H:

TO : Environmental Fate and Effects

**Di ~isio**  Brian Anderson , Chief 

# /rt <IJ ___.- Environmental Risk Branch 2 v



# ~ Environmental Fate and Effects Divi sion (7507P) Kaitlin Keller, Risk Manager Review Michael Goodis , Risk Manager Risk Management and Implementat ion Branch 3 Pesticide Re-evaluation Divi s ion (7508P)

The registrant , E

. I. duPont de Nemours Company, has subm itted two reports (MRIDs 48904003 and 48904004) in response to a Data Call-In (DCI ) for an Environmental Chemistry Method (ECM) and an Independent Laboratory Validation (ILV) to fulfill guideline 835.6100 (terrestrial field dissipation) for tribenuron-methyl. Based on the discussions below, the submitted two reports are not reviewable. A modified ECM with higher acceptable quantitative recoveries for tribenuron-methyl and an acceptable IL V for the modified ECM are needed to fulfill this DC!. Both reports contain data confidentiality markings (e.g., "Trade Secret") and statements that limit their release to the public and to foreign parties. The Agency requests resubmiss ion of the ECM and ILV reports with data confidentiality markings or statements other than the standard Statement ofNo Data Confidentiality removed so that the reports can be publicly posted on the Agency's website. 

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# I 11111 2088035MRID 48904004

- Analytical Method for the Determination of 13 DuPont Sulfonylurea**Herbic~des** in Soil Using LCIMSIMS The method is designed for multi-analytes of 13 sulfonylurea (SU) herbicides in soil. Due to poor stability in aqueous solutions at low pH, tribenuron-methyl recoveries were poor and a modified method was described for analysis of tribenuron-methyl. To fulfil the DCI for tribenuron-methyl , submission of the modified method is recommended with quantitative recoveries demonstrated by internal validation. ECM recoveries are quanitative when the mear1 value is 70-120% and the relative standard deviation is less than 20%. The Agency has no position on whether to include as analytes any of the other 12 SUs. MRID 48904003 -Suitability ofDuPont-5082 , Revision No.1 as a Monitoring Methed for Azimsulfuron, Bensulfuron-Methyl , Chlorimuron-Ethyl, Chlorsulfuron, EthametsulfuronMethyl , Flupyrsulfuron-Methyl, Metsufuron-Methyl, Nicosulfuron , Rimsulfuron, Sulfometuron-Methyl , Thifensulfuron-Methyl , Tribenuron-Methyl and TriflusulfuronMethyl in Soil TheILV report was not properly prepared, since the independent laboratory (University of Iowa Hygienic Laboratory) did not prepare the report. There was no documentation of any contact between the independent laboratory and the developers of the method. The ECM was not validated, since recoveries for tribenuron-methyl were poor. Mean recoveries were 54 and 67 % , respectively for German soils and American soils. In order for an ECM and its associated ILV report to be reviewable, the internal and independent validations and their documentation should be consistent with OCSPP guideline 850.6100 and both validations should produce quantitative recovenes.

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