OFFICE OF PREVENTION, PESTICIDES AND TOXIC SUBSTANCES UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON D.C., 20460



### PC Code: 129008 DP Barcodes : 418780, 401791, and 416755

MEMORANDUM Date: August 20, 2015

SUBJECT: Nicosulfuron Environmental Fate Study Data Reviews: Aerobic soil metabolism (OCSPP Guideline No. 835.4100) Batch Equilibrium/Adsorption, Desorp tion, Leaching (OCSPP Guideline No. 835.1230) Soil ECM & ILV (OCSPP Guideline No. 850.6100) Water ECM & ILV (OCSPP Guideline No. 850.6100)

TO: Miguel Zavala, Chemical Review Manager Kelly Sherman, Branch Chief Risk Management and Implementation Branch III Pesticide Re-evalu ation Division (7508P)

Kable Davis, Risk Manager (RM-25) Daniel Kenny, Risk Manager Reviewer Herbicide Branch Registration Division (7505P)

This memorandum transmits the Environmental Fa te and Effects Division’s (EFED’s) data reviews for several environmenta l fate studies requested to s upport the Nicosulfuron Registration Review risk assessment. The st udy classifications are shown in Table 1 below. Data evaluation records (DERs) documenting EFED’s study review have been prepar ed for each study shown in Table 1 and accompany this memo.

Please note that while the Environmental Ch emistry Methods and Independent Laboratory Validations (ECMs and ILVs) in both soil and water for nicosulfuron were found acceptable (MRID Nos. 48790911, 487090913, 48790912, and 48790914) , there will still be a data gap for this study in the future considering that the le vel of detection (LOD) and level of quantitation (LOQ) established in the methods were not sufficient enough to encompass the low

### 2 concentrations with toxicologica l endpoints determ ined for terrestrial plants and expected for aquatic plants with nicosulfuron. Further information related to LODs and LOQs established for other existing methods can be found within the DERs.

Please contact Gabe Rothman at (7 03) 347-8011 with any questions.

### 3 Table 1. Summary of da ta classifications of r ecently submitted studies for nicosulfuron.

Guideline Study Citation MRID Study Classification Test Substance 835.4100 Aerobic Soil Metabolism: Sarff, P. 2004. Rate of 14C-Nicosulfuron Degradation in Three Soils. Unpublished study performed by ABC Laboratories, Inc., Columbia, Missouri and DuPont Crop Protection, Newark, Delaware; sponsored and submitted by E.I. du Pont de Nemours and Company, Wilmington, Delaware. DuPont Study No.: 10929; ABC Study No.: 47547. Experimental work conducted between August 13, 2002 and November 19, 2003 (p. 6). Final report issued April 1, 2004. 49169703 Supplemental Nicosulfuron TGAI

835.1230 Batch Equilibrium (Adsorption, Desorption, and Leaching)Aikens, P.J. 2001. Adsorption/Desorption of [14C]INJ0290 in Five Soils. Unpublished study performed by Huntingdon Life Sciences Ltd., Cambridgeshire, England; sponsored and submitted by E.I. du Pont de Nemours and Company, Wilmington, Delaware. DuPont Project ID DuPont-5264. Huntingdon Project ID DPT 564. Experimental initiation February 23, 2001 and completion May 25, 2001 (p. 11). Study completion date November 2, 2001. 49169701 Accepta ble IN-J0290 Mebabolite

850.6100 ECM/ILV in Soil Cabusas, M.E.Y. 2012. Anal ytical method for thedetermination of nicosulfuron (DPX-V9360), INV9367 and IN-J0290 in soil using HPLC/ESIMS/MS. Laboratory Project ID: DuPont-33143. Report prepared by E.I. du Pont de Nemours and Company, Newark, Delaware, sponsored and submitted by E.I. du Pont de Nemours and Company, Wilmington, Delaware; 50 pages. Final report issued March 16, 2012.

Rogers, P. 2012. Independent laboratory validation of DuPont-33143, “Analytical method for thedetermination of nicosulfuron (DPX-V9360), INV9367 and IN-J0290 in soil using HPLC/ESIMS/MS”. DuPont Project ID: DuPont-33031. Alliance Pharma Project No.: 120103. Report prepared by Alliance Pharma, Inc., Malvern, Pennsylvania, sponsored and submitted by E.I. du Pont de Nemours and Company, Wilmington, Delaware; 52 pages. Final report issued March 22, 2012. 48790912 & 48790914 Acceptable* Nicosufuron, IN-V9367 Metabolite, and IN-J0290 Metabolite

850.6100 ECM/ILV in Water Morgan, E.A. and Cabusas, M.E.Y. 2012. Analyticalmethod for the determination of nicosulfuron (DPXV9360), IN-V9367 and IN-J0290 in water usingHPLC/ESI-MS/MS. Laboratory Project ID: DuPont32132. Report prepared by E.I. du Pont de Nemours and Company, Newark, Delaware; sponsored and submitted by E.I. du Pont de Nemours and Company, Wilmington, Delaware; 54 pages. Final report issued March 16, 2012. 48790911 & 48790913 Acceptable* Nicosufuron, IN-V9367 Metabolite, and IN-J0290 Metabolite

### 4 Guideline Study Citation MRID Study Classification Test Substance

Ro baugh, D.A. 2012. Independent laboratory validation of DuPont-32132, “Analytical method forthe determination of nicosulfuron (DPX-V9360), INV9367 and IN-J0290 in water by HPLC/ESIMS/MS”. DuPont Study No: DuPont-32578. Pyxant Labs Project ID: 2388. Report prepared by Pyxant Labs Inc., Colorado Springs, Colorado; sponsored and submitted by E.I. du Pont de Nemours and Company, Newark, Delaware; 92 pages. Final report issued March 30, 2012. * While the Environmental Chemistry Methods and Independent Laboratory Validations (ECMs and ILVs) in both soil and water for nicosulfuron were fou nd acceptable, there will still be a data ga p for this study in th e future

con sidering that the level of d etection (LOD) and the lev e l of qua ntitation (LOQ) established in the methods we re not sufficient

en o ugh to en compass the lo w concen trations fo r toxicological endpoints determin ed for terrestrial plants and expected for aquatic p lants with nicosulfuron. Furthe r information rel ated to LODs and LOQs established f

or other existing methods can b e f ound within the DERs.