UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON D.C., 20460

OFFICE OF CHEMICAL SAFETY AND POLLUTION PREVENTION



### MEMORANDUM

DATE:

SUBJECT:

FROM:

THRU:

TO: May 14,2013

Registration Review- Preliminary Problem Formulation for the Ecological Risk Assessment for Trifloxysulfuron-Sodium (PC Code 119009; DP Barcode 408408)

Tanja Crk, M.A., Biologist

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### James K. Wolf, Ph.D., Environmental Scientist Environmental Risk Branch 3

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### Dana Spatz, Branch Chief Rosanna Louie-Juzwiak, RAPL Environmental Risk Branch 3 Environmental Fate and Effects Division (7507P)

Kelly Ballard, Chemical Review Manager Neil Anderson, Chief Risk Management and Implementation Branch 1 Pesticide Reevaluation Division (7508P) 

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The Environmental Fate and Effects Division (EFED) has completed the preliminary problem formulation (attached) for the ecological risk and endangered species assessments to be conducted as part ofthe Registration Review oftrifloxysulfuron-sodium. This document is intended to provide an overview of what is currently known regarding the environmental fate and ecological effects associated with trifloxysulfuron-sodium and its degradation products, and outlines uncertainties regarding attributes of the parent compound and its transformation products. It 

### describes the preliminary ecological risk hypothesis and the processes that will be used during the completion of the ecological risk assessment in support of Registration Review.

### 2 

# Problem Formulation for the Ecological Risk Assessment in Support of the Registration Review of Trifloxysulfuron-Sodium

Trifloxysulfuron-Sodium



### Prepared by: James K. Wolf, Ph.D., E nvironmental Scientist Tanja Crk, M.A., Biologist

Reviewed by: Melissa Panger, Ph.D., Senior Biologist

James Hetrick, Ph.D., Senior Advisor Rosanna Louie-Juzwiak, RAPL

Approved by: Dana Spatz, Branch Chief Environmental Risk Branch III Environmental Fate a nd Effects Division

May 14, 2013

### 3 1. INTRODUCTION

The purpose of this problem formulation is to provide EFED’s current understanding of the environmental fate and ecological effects of th e registered uses of trifloxysulfuron-sodium [2-Pyridinesulfonamide,N-[[(4,6-dimet hoxy-2-pyrimidinyl)-amino]carbonyl]-3-(2,2,2- trifluoroethoxy)-, monosodium salt]. This document provides a plan for analyzing data relevant to trifloxysulfuron-sodium and for assessing pote ntial risk to non-target organisms, including Federally-listed endangered/threat ened species (hereafter referred to as “listed” species), and potential exposure in drinking water for the human health risk assessment.

Trifloxysulfuron-sodium is the activ e ingredient (a.i.) in selective herbicides intended to control or suppress a variety of broadl eaf, sedge and grass weeds as a post-emergence uses on cotton, sugarcane, citrus, almonds; for pre-emer gence and post-emergence on tomatoes, and on established turf. Trifloxysulfur on-sodium slows or stunts plant gr owth (or causes ultimate plant death) by limiting amino acid synthesis in plan ts through inhibition of acetolactate synthase (ALS). Other chemical familie s of ALS-inhibitors are the im idazilinones (imazapyr, imazaquin), the triazolopyrimidines (flumetsulam), the pyrimid inyl(thio)benzoates (pyr ithiobac-sodium), and the sulfonyaminocarbonyltriazoli nones (flucarbazone-Na).

The end use products proposed for trifloxysulfuron- sodium consist of water dispersible granules and emulsifiable concentrates containing 75% trifloxysulfuron-s odium as the active ingredient, and a granular co-formulated w ith the active ingred ients 0.7 % trifloxysulfuron-sodium and 79.3 % prometryn (CAS Reg No. 7287-19-6; PC Code 080805).

Additionally, this problem formulation is inte nded to identify data gaps, uncertainties, and potential assumptions used to address those uncertainties, relative to characterizing the ecological risk associated with the registered uses of trifloxysulfuron-sodium.

The structure of trifloxysulfuron-sodium, as well as the chemical name and other identifiers are provided in Table 1 . Trifloxysulfuron-sodium (salt) will dissociate, losing the sodium ion, under environmentally relevant conditions (pKa = 4.76) . Trifloxysulfuron-sodium is structurally similar to trifloxysulfuron (aci d) which is also shown in Table 1

.

### 4 Table 1. Trifloxysulfuron-sodium Chemical Identifiers

2. Parameter 3. Identifier

Trifloxysulfuron-sodium (salt) Chemical Structure

Empirical Formula C 14 H 13 F 3 N 5 NaO 6 S

Chemical Name And Synonyms IUPAC: sodium N ′ -(4,6-dimethoxypyrimidin-2-yl)- N -[3-(2,2,2-trifluoroethoxy)-2- pyridylsulfonyl]imidocarbamate

Sodium (4,6-dimethoxypyrimidin-2-yl)({[3-(2,2,2-trifluoroethoxy)pyridin-2- yl]sulfonyl}carbamoyl)azanide

2-Pyridinesulfonamide,N-[[(4,6-dimethoxy-2-pyrimidinyl)-amino]carbonyl]-3-(2,2,2- trifluoroethoxy)-, monosodium salt

Trifloxysulfuron sodium salt

Trifloxysulfuron-sodium

CAS Number 290332-10-4 (from US EPA) (sodium salt monohydrate) 199119-58-9 (from www.hclrss.demon.co.uk ) (sodium salt) Company Code CGA-362622 

### Trifloxysulfuron Chem ical Identifiers

Trifloxysulfuron (acid) Chemical Structure

Empirical Formula C 14 H 14 F 3 N 5 O 6 S

Chemical Name And Synonyms IUPAC: 1-(4,6-dimethoxypyrimidin-2-yl)-3-[3-(2,2,2-trifluoroethoxy)-2-pyridylsulfonyl]urea CAS: N -[[(4,6-dimethoxy-2-pyrimidinyl)amino]carbonyl]-3-(2,2,2-trifluoroethoxy)-2- pyridinesulfonamide CAS Number 145099-21-4 Company Code CGA-292230

### 5 2. USE CHARACTERIZATION

In addition to the technical product (Reg. No. 10 0-1133), there are three e nd-use products that contain trifloxysulfuron-sodium: Envoke He rbicide (Reg. No. 100-1132), Monument 75 WG Herbicide (Reg. No. 100-1134), and Suprend Herbicide (Reg. No. 100-1163) which also contains the active ingredient Prometryn (PC Code 080805). A special local needs registration (24c) has used Envoke Herbicide (Reg. No. MS11004). A su mmary of all the trif loxysulfuron-sodium products is provided in Table 2

.

Table 2. Trifloxysulfuron-sodium Formulated Products

EPA Registration

Number Product Name CAS No. Amount Active Ingredient

(% AI) (Product Code) Physical Forum

100-1132 Envoke ® Herbicide 290332-10-4 75 Emulsifiable Concentrate 100-1133 Trifloxysulfuron-sodium Technical 290332-10-4 94 Technical

100-1134 Monument ® 75WG Herbicide 290332-10-4 75 Water Dispersible 100-1163 SuprendTM Herbicide a 199119-58-9 0.7 Granular

MS110004 Envoke ® Herbicide 290332-10-4 75 Emulsifiable Concentrate

a Prometryn (79.3 % AI) 2,4-bis (isopropylamino)-6 -methylthio-s-triazine (CAS Reg. No. 7287-19-6).



### Based on the usage report prepared by OPP’ s Biological and Economic Analysis Division, 3000 and 1000 pounds (ai) of trifloxysulfuron-sodium is used per year on corn and sugar cane, respectively. 1 

### Usage data for other uses ( i.e. , non-agricultural uses) are not available. All currently registered uses of trif loxysulfuron-sodium are listed in Table 3

.

1 BEAD, 2013 Usage/Use Report in Support of Registration Review for Trifloxysulfuron sodium (119009), Screening Level

Usage Analysis (SLUA) Date: June 15, 2012Table 3. Registered Uses, Application Rates andMethods of Trifloxysulfuron-sodium Applications.Site DescriptionReg#A. I. Max AppRate(lb ai/a)Max#Apps@MaxRate/ CCA. I. MaxAppRate/YearProductSeasonalMaxDose/CCA. I.SeasonalMaxDose/CCMax#Apps@MaxRate /UnitofTimeMinimumRetreatmentIntervalApplicationMethodTypeApplicationMethodEquipmentApplicationMethodTimingAGRICULTURALFALLOW/IDLELAND /CONSERVATION RESERVE100-1132.007031NS.01875NSNSNSNSSpray.Ground.Fall.AIRPORTS/LANDINGFIELDS100-11340.02482NS.079688NSNSNS28 dSpottreatment.Backpacksprayer.Weedpostemergence.AIRPORTS/LANDINGFIELDS100-11340.024844NS.079688NSNSNS28 dSpray.Ground.Weedpostemergence.ALMOND100-11320.01875NSNS1.2 oz / a.0563NS30 dSpray.Ground.Establishedplantings.CITRUS100-11320.01875NSNS1.2 oz / a.0563NS30 dSpray.Ground.Establishedplantings.COMMERCIAL/INDUSTRIALLAWNS100-11340.02482NS.079688NSNSNS28 dSpottreatment.Backpacksprayer.Weedpostemergence.COMMERCIAL/INDUSTRIALLAWNS100-11340.024844NS.079688NSNSNS28 dSpray.Ground.Weedpostemergence.COTTON (UNSPECIFIED)100-11630.0105NSNS2.7.0189NS14 dBasal spraytreatment.Sprayer.Foliar.COTTON (UNSPECIFIED)100-11630.0105NSNS2.7.0189NS14 dDirectedspray.Sprayer.Foliar.COTTON (UNSPECIFIED)100-11320.007031NS.007031NSNSNS14 dGroundspray.Sprayer.Postemergence.COTTON (UNSPECIFIED)100-11320.007031NS.007031NSNSNS14 dSpray.Ground.Postemergence.COTTON (UNSPECIFIED)100-11320.011719NSNS.4 oz / a.0188NS14 dDirectedspray.Ground.Postemergence.GOLF COURSE TURF100-11340.02482NS.079688NSNSNS28 dSpottreatment.Backpacksprayer.Weedpostemergence.GOLF COURSE TURF100-11340.024844NS.079688NSNSNS28 dSpray.Ground.Weedpostemergence.ORNAMENTAL SOD FARM(TURF)100-11340.02482NS.079688NSNSNS28 dSpottreatment.Backpacksprayer.Weedpostemergence.7Site DescriptionReg#A. I. Max AppRate(lb ai/a)Max#Apps@MaxRate/ CCA. I. MaxAppRate/YearProductSeasonalMaxDose/CCA. I.SeasonalMaxDose/CCMax#Apps@MaxRate /UnitofTimeMinimumRetreatmentIntervalApplicationMethodTypeApplicationMethodEquipmentApplicationMethodTimingORNAMENTAL SOD FARM(TURF)100-11340.024844NS.079688NSNSNS28 dSpray.Ground.Weedpostemergence.RECREATIONAL AREAS100-11340.02482NS.079688NSNSNS28 dSpottreatment.Backpacksprayer.Weedpostemergence.RECREATIONAL AREAS100-11340.024844NS.079688NSNSNS28 dSpray.Ground.Weedpostemergence.RESIDENTIAL LAWNS100-11340.02482NS.079688NSNSNS28 dSpottreatment.Backpacksprayer.Weedpostemergence.RESIDENTIAL LAWNS100-11340.024844NS.079688NSNSNS28 dSpray.Ground.Weedpostemergence.SUGARCANE100-11320.0140633.070312NSNSNS14 dDirectedspray.Ground.Postemergence.SUGARCANE100-11320.0140633.070312NSNSNS14 dSpray.Ground.Postemergence.SUGARCANE100-11320.0140633.070312NSNSNS14 dSpray.Sprayer.Foliar.SUGARCANE100-11320.0281253.070312NSNSNS14 dDirectedspray.Ground.Layby.SUGARCANE100-11320.0281253.070312NSNSNS14 dDirectedspray.Ground.Ratoon.TOMATO100-11320.0093751.014062NSNSNSNSDirectedspray.Ground.Posttransplant.TOMATOMS1100040.0093751NS.3 oz / a.0141NSNSDirectedspray.Ground.Posttransplant.TOMATOMS1100040.0093751NS.3 oz / a.0141NSNSSpray.Ground.Posttransplant.

### 3. CONCLUSIONS FROM PREVIOUS RISK ASSESSMENTS

One ecological risk assessment has been comp leted for trifloxysulfuron-sodium: the new chemical assessment (cotton, citrus, suga rcane, almonds, tomatoes, and turf; D276988 2 

### ; August 11, 2003). EFED evaluated this assessment in associ ation with the current toxicity, exposure, and usage information to determine if sufficient data are available and if further updates are needed to support registration review.

Potential direct risk to terrestri al and aquatic vascular and non-v ascular plants from the use of trifloxysulfuron-sodium is expected. There is also the potential for various indirect effects on non-target animal species due to the effects on th e plant community (for example, depletion of food sources and habitat). The major conclusions presented in the new chemical assessment for trifloxysulfuron-sodium are summarized in Table and are briefly discus sed in the subsections below. All registered uses will be considered as part of the registration review risk assessment.

Table 4. Summary of Risk Concerns Identified fo r Trifloxysulfuron-Sodium in Previous Assessments

Birds Mammals Terrestrial Plants Terrestrial Inverts Fish Aquatic Inverts Aquatic Plants Groundwater Contamination Persistence Degradates of Concern

-- -- √

-- -- -- √ √ √

-- *The checkmarks indicate that the par ticular element was found to have a risk concern in the previous assessment.



### For all proposed uses, trifloxysulfuron-sodium ex ceeded levels of concern (LOCs) for risk to terrestrial plants, non-listed and list ed, as a result of spray drift and runoff. Label precautions for uses on citrus and almond groves suggest that fruiting trees may be very sensitive to trifloxysulfuron-sodium via spray drift.

On all proposed uses, trifloxysulfuron-sodium in runoff exceeded LOCs for acute risk to aquatic plants. Trifloxysulfuron-sodium was found to be more phytotoxic to aquatic vascular plants at acidic than alkaline pH.

Trifloxysulfuron-sodium did not exceed LOCs fo r non-listed or listed te rrestrial and aquatic (freshwater; estuarine) animals. Trifloxysulfuron-sodium was determ ined as not toxic to birds or mammals. However, there is potential for indirect effects by loss of any plan t habitats as a result of inadvertent exposure to the chemical.

Trifloxysulfuron-sodium has the potential to l each to ground water and/or reach to surface water by direct runoff. If residues of trifloxysulfuron-so dium were to reach irrigation water sources in high enough concentrations, there is a potential for damage to vulnerable crops and non-target terrestrial plants. In surface wate r, runoff events may have an acu te effect on aquatic vascular plants.

2 USEPA, 2003. Section 3.Trifloxysulfuron Sodium (“Trifloxysulfuron”) Section 3 for cotton, sugarcane, almonds, citrus,

tomatoes, and turf 2- Pyridinesulfonamide, N -[[(4,6-Dimethoxy-pyrimidinyl)amino]carbonyl]-3-(2,2,2-trifluroethoxy), monosodium salt CAS Registry Number(s) 29032-10-4 (sodium salt monohydrate); 199119-58-9 (sodium salt); 1450099-41-4 (free sulfonylurea), Company Code CGA 362622; August 11, 2003; DB Barcodes: D276988; D280727; D284104; D284108; D284113; D284117; D284478

### 9 Previous Drinking Water Assessments

A drinking water assessment (D WA) was prepared by EFED at the time of the new chemical assessment for parent trifloxysulfuro n-sodium only as highlighted in Table 5

. The Health Effects Division (HED) determined that the residues of concern in drinking water are parent trifloxysulfuron, C GA-053052, CGA-382997, and CGA-368732 3 

### . Structures and chemical names are given in Appendix A . In order to account for th e potential residues of these breakdown products in water, the parent as well as the maximum percent formation of these metabolites (of the applied parent compound observed in 14 

### C-environmental fate studies) were considered. Those values are 61% of the a.i. for CGA-053052 (hydrolysis at pH 5 after 30 days), 54% of the a.i. for CGA-382997 (aerobic soil metabolism after 365 days), and 53% of the a.i. for CGA-368732 (hydrolysis at pH 7 after 30 days). To account for the total residues of concern, the conversion factor (from parent compound to all residues of concern) is , therefore, 2.68. This assumption results in conservative levels of the total re sidues of concern sin ce it assumes that all of the compounds occur simultaneously, and does not consider the kinetics of their formation and dissipation. These total-residue estimated drinking water concentrations (EDWCs) have been used directly in the dietary assessment (see below) to estimate dietary exposure to trifloxysulfuron from food and drinking water. The surface water estimates were used for acute (10.26 ppb) and chronic (0.83 ppb) dri nking water exposure assessments.

Table 5. Summary of Estimated Surface and Ground Water Concentrations for Trifloxysulfuron-sodium and Associated Residues of Concern. Exposure Duration Trifloxysulfuron-sodium (D276988; 08/20/03) Trifloxysulfuron-sodium + CGA-053052 + CGA-382997 + CGA-368732 a
Surface Water

Conc., ppb b Ground Water Conc., ppb c Surface Water Conc., ppb Ground Water Conc., ppb Acute 3.83 0.032 10.26 0.086 Chronic (non-cancer) 0.31 0.032 0.83 0.086

a HED included the following trifloxysulfuron-sodium me tabolites, using maximum formation values of thesedegradates observed in available fate studies:0.61 for CGA-053052, 0.54 for CGA382997, and 0.53 for CGA368732; as provided in the MARC Report (TXR No. 0052100, 8/25/03). The conversion factor for trifloxysulfuron-sodium to all residues of concern is 2.68 (USEPA, 2008).

b From the Tier II PRZM-EXAMS - Index Reservoir model. Input parameters are based on sugarcane grown in Florida.

c From the SCI-GROW model assuming a maximum seasonal use rate of 0.0788 lb ai/A, a K oc of 29, and a half-life of 29.84 days.



### EFED will prepare a updated drinking water assessment for trifloxysulfuron-sodium and the drinking water degradates of concer n (CGA-053052, CGA-382997, and CGA-368732) following EFED guidance appropriate at that time. Us ing EFED aquatic models, the drinking water assessment will incorporate model estimates of tr ifloxysulfuron-sodium and its degradates in surface water ( e.g. , PRZM-EXAMS) and groundwater ( e.g. , (PRZM-GW).

3 USEPA, 2003. Health Effects Division. Trifloxy sulfuron-sodium: Metabolism Assessment Review Committee

Report. DP Barcode D293085. August 25, 2003.

### 10 Clean Water Act Programs

Trifloxysulfuron-sodium is not identified as a cau se of impairment for any water bodies listed as impaired under section 303(d) of the Clean Wate r Act. No Total Maximum Daily Load (TMDL) criteria have been developed for trifloxysulfuron-sodium. Aquatic Life Ambient Water Quality Criteria documents or Aquatic life benchmarks have not been published for trifloxysulfuronsodium.

The Agency will consider availa ble monitoring data such as th e USGS National Water Quality Assessment (NAQWA), USEPA STORET database and, California Depart of Pesticide Regulations (CDPR) Surface Water Database. The Agency invites submission of water quality data for this pesticide. To the extent possible, data should conform to the quality standards in Appendix A of the OPP Standard Operating Procedure: In clusion of Impaired Water Body and Other Water Quality Data in OPP’s Regist ration Review Risk Assessment and Management Process (see: http://www.epa.gov/oppfead1/cb/p pdc/2006/november06/session1-sop.pdf ), in order to ensure they can be us ed quantitatively or qua litatively in pesticide risk assessments.

4. ENVIRONMENTAL FATE AND TRANSPORT

Physical and Chemical Propertie s of Trifloxysulfuron-Sodium

The physicochemical properties of trifloxysulfuron-sodium are shown in Table 6 . Based on these properties alone, trifloxysulfur on-sodium is not expected to be volatile or to bioaccumulate. It is highly soluble in water.

Table 6. Selected Physical/Chemical Parameters of Triflo xysulfuron-Sodium

Parameter Value Source/Classification Empirical Formula C 14 H 13 F 3 N 5 NaO 6 S 45371702

Molecular mass (molecular formula) 459.3 45371702

Vapor Pressure, 25  C * < 1.3 x 10 -6 Pa <9.75 x 10 -9 torr 45371702

Henry’s Law Constant, 25  C (Estimated) 2.6 x 10 -5 Pa m 3 /mol 2.29 x10 -13 atm m 3 /mole 45371702

Aqueous solubility (25  C) 25.7 g/L @ pH 7.4 (25,700 mg/L) No data are available on the solubility of this chemical at pH 5 and 9 45371702

Log octanol-to-water partition coefficient (log K OW ) 1.40 @ pH 5 -0.42 @ pH 7 -1.60 @ pH 9.1 45371702

Dissociation Constant, pK a (acidic) 4.76 45371702

### 11 Environmental Fate Properties of Trifloxysulfuron-Sodium

Environmental fate properties of trifloxysulfuron-sodium are summarized in Table 7

. These half-life estimates will be updated to reflect current guidance, if needed, from previous assessments to reflect the NAFTA degradation kinetics guidance. 4 

### The results are similar to those previously reported in the data evaluation records (DER s). For many studies, the DERs indicated that trifloxysulfuron-s odium transformation could not al ways be adequately described using single first order kinetics.

Hydrolysis is the major route of transformation in the environment. Rates of hydrolysis (halflives) and types, mechanism of formation, and predominance of degradation products is pHdependent. Given the considerable variability in soil and water pH across the proposed use area, considerable variability in persiste nce and nature of degradates is to be expected. Like all of the sulfonylurea herbicides, trifloxysulfuron-sodium is very mobile. Although the persistence and mobility of trifloxysulfuron-sodium in soils ma y be considered moderate when compared to other very persistent and mobile sulfonylurea herbicides ( e.g. , chlorsulfuron), there is still the potential for leaching and runoff. The chem ical names and abbreviation of the major degradation/transformation products are listed in Table 9 . Chemical names and structures are given in Appendix A

.
At acidic pHs, hydrolysis is faster than at neutral-to-basic pHs (h alf-lives of 6 days at pH 5 and 20-22 days at pH 7 and 9). The products prevailin g under acidic condition ar e distinctly different as those prevailing under alkaline conditions an d are formed by very different chemical mechanisms. The predominant products in acidic media contain a single ring, CGA-382997 (pyridine) and CGA-53052 (pyrim idinyl). These degradates ar e formed by cleavage of the sulfonylurea bridge. The predominant products un der alkaline conditions ha ve the two rings, but a shorter bridge and are formed by elimination of the sulfonyl and the urea groups, followed by re-bridging. These degradates are CGA- 368732, CGA-368733, and NOA-436664. This bridge elimination/re-bridging mechanism has been do cumented for other sulfonylurea herbicides containing a pyridine ring, such as nicosulfur on and rimsulfuron. A generalized degradation pathway of trifloxysulfuron-sodium in the environment is shown in Figure 1.

4 Guidance for Evaluating and Calculating Degradation Kinetics in Environmental Media , Health Canada, U.S.

Environmental Protection Agency, December 2012.

### 12 Figure 1. Degradation Pathways of Trifloxysulfuron-sodium in the Environment.



### The estimated half-lives of tr ifloxysulfuron-sodium are 29-79 days in aerobic soils (DT 90 

### > 235 days), 9-13 days in anaerobic water-sediments, 11- 16 days in aerobic water-sediment systems, and 9-25 days in California and 6-10 days in Louisiana in field dissipation studies. The pHdependent predominance of one type of degr adate over the other was observed in both homogeneous aqueous media (abi otic hydrolysis study), in hete rogeneous media (soils; watersediment systems), and in the field. Of all the degradation products, CGA-382997 appears to be the most persistent. The degradate CGA-53052 is also a common degradate of other sulfonylurea herbicides. The half-lives for th e degradates of concern which we re found in the aerobic soil and aerobic and anaerobic aquatic metabo lism studies are also shown in Table 7

.
The transformation of trifloxysulfuron-sodium in water-sediment systems, while dominated by hydrolytic reactions (abiotic), incl udes a clearly metabolic pathway that involves loss of a methyl group from the 4,6-dimethoxypyrimidinyl moiety to form NOA-436664. This metabolic pathway was not observed in laboratory st udies conducted with soils or in abiotic aqueous media, but it was identified in the field. While the rates of transformation under aerobic and anaerobic conditions were comparable (14- 21 days for the bulk system), some variation was found in the amount and distribution of produc ts between the aqueous and sediment phases. However, under the experimental conditions of the studies, formation of bridge-contraction products was significant, but formation of cleavage products was not. See Table 9

.

### 13 Photolysis in water (direct) or on soil is not an importa nt transformation pathway for trifloxysulfuron-sodium. Volatiliza tion is not anticipated to be a significant dissipation pathway from soil.

Trifloxysulfuron-sodium and three of its degradates (CGA-382997, CGA-53052, and CGA368732) do not bind strongly to soils and have leach ing and runoff potential. Binding to soils is stronger for the degradates CGA-368733 and NOA-436664. In water-sediment studies these degradates were predominantly found in the sediment. Thus, trifl oxysulfuron-sodium, CGA382997, CGA-53052, and CGA-368732 are th e chemical species that would most likely be found in water

### 14 Table 7. Environmental Fate Parameters of Trifloxysulfuron-Sodium and degradates

Parameter Value Source/Classification

Persistence

Hydrolysis half-life (25  C) 2.7- 2.9 days @ pH 4 5.7 - 5.8 days @ pH 5 19.8 - 20.8 days @ pH 7 21.3 -22.2 days @ pH 9 45371804 45371805

Aqueous photolysis half-life (25  C @ pH 7) Pyrimidine label: 423 days Pyridine label: 63 days 45371806 45371807 45893304

Soil photolysis half-life (25  C) Pyrimidine label: 79.5 days Pyridine label: 79.3 days 45371808 45371809

Aerobic soil metabolism half-life (25°C) Trifloxysulfuron-sodium Pyridine label: t 1⁄2 = 54 days Pyrimidine label: t 1⁄2 = 79 days

Trifloxysulfuron + degradates Pyridine label: t 1⁄2 = 1695 days a Pyrimidine label: t 1⁄2 = 371.6 days b 45371810 45371811

45371810 45371811

Anaerobic aquatic metabolism half-life (25°C) (Total System: water + sediment) Trifloxysulfuron-sodium Pyridine label: t 1⁄2 = 21.8 days Pyrimidine label: t 1⁄2 = 15.9 days

Trifloxysulfuron-sodium + degradates Pyridine label: t 1⁄2 = 127.9 days c Pyrimidine label: t 1⁄2 = 146.6 days d 45371812 45371813

45371812 45371813

Aerobic aquatic metabolism half-life (25°C) Trifloxysulfuron-sodium Pyridine label: t 1⁄2 = 17.6 days Pyrimidine label: t 1⁄2 = 21.1 days

Trifloxysulfuron-sodium+ degradates Pyridine label: t 1⁄2 = 43.9 days e Pyrimidine label: t 1⁄2 = 92.3 days f 45371814 45371815

45371814 45371815

Mobility

Freundlich K ads and Koc See Table 8 . -- Field Dissipation

Terrestrial field dissipation half-life CA-cotton : t 1⁄2 = 25 days CA-bare ground : t 1⁄2 = 9 days LA-sugarcane : t 1⁄2 = 10.4 days LA-bare ground : t 1⁄2 = 5.8 days 45371828 45371829

a Parent + degradates CGA-382997, CGA-368733

b Parent + degradates CGA-53052, CGA-368733

c Parent + degradates CGA-53052, CGA-368733

d Parent + degradates CGA-382997, CGA-368733

e Parent + degradates CGA-382997, CGA-368733

f Parent + degradates CGA-53052, CGA-268733

### 15 The Freundlich sorption coefficients (K ads 

### ) and soil organic carbon coefficient (Koc) for the major degradates are shown in Table 8

.
Based upon soil organic carbon coefficient ( Table 8 ), K oc 

### , CGA-382997 would be mobile, trifloxysulfuron-sodium; CGA-5305 2, CGA-368732 would be mobile to moderately mobile; and CGA-368733 and NOA-436664 would be moderately m obile to slightly mobile, according to mobility classification scheme adapted from the FAO by EFED (USEPA, 2006 5 

### ).

Table 8. Freundlich Adso rption Coefficients (K ads ) and Kocs for Trifloxysulfuron-sodium and its Major Degradates (5 U.S.A soils)



### .

Sorption Parameter Parent: Trifloxysulfuron -Sodium CGA-382997 CGA-53052 CGA-368732 CGA-368733 NOA-436664

MRID 45371825 45371721 4537123 45371820 45371824 45371816

K ads (mL/g) 0.31- 0.88 0.17- 0.30 1.2- 2 0.26- 1.2 14- 137 3.9- 28 Koc (ml/g oc ) 29- 147 15- 50 75- 425 43- 200 875- 22817 650- 1925

1/N 0.90 - 0.99 0.70 - 0.80 0.70 - 0.97 0. 90 - 0.96 0.56 - 0.93 0.71 - 0.83



### Transformation Products

Trifloxysulfuron-sodium like other sulfonylurea herbicides containing a pyridine ring can eliminate the sulfonyl and the urea groups from the bridge and th en re-bridge to form products with a shorter ring. The trifluoroe thyl group in the pyridine is very stable. One of the degradates of trifloxysulfuron-sodium , CGA-53052 (4,6-dimethoxy-pyrimid ine) is common to other sulfonylurea herbicides, such as rimsul furon, nicosulfuron, and foramsulfuron.

Table 9 summarizes the mechanisms by which trifl oxysulfuron-sodium degrades together with the chemical names. Chemical structures are shown in Figure 1 and Appendix A

.
The cleavage products predominate at acidic pHs while the bridge-elimination/contraction products predominate at alkaline pHs. While this is a general observation, at intermediate pHs both types of degradates may form but at variable ratios. For this reason, it is exp ected that there would be considerable variati on in exposure to specific degrad ates throughout the proposed use area. See Table 10 and compare the distributi on of degradates depending on the pH of the media.

The degradate CGA-382997 appears to be the most st able of the degradates, as it continues to form ( i.e. , increase) throughout the aer obic soil metabolism studies. At the present time, EFED has not determined the kinetics (rates of formati on and decline; half-life) for the degradates in the aerobic soil metabolism studies or other syst ems. Although some fate studies do not allow for determination of the kinetics of the individual degradation pro ducts, data are sufficient to determine the degradation rate of the residues of concern usin g the total toxic residue (TTR) methodology.

5 USEPA, 2006. Standardized Soil Mobility Classificati on Guidance. Memorandum: S. Bradbury, April 21, 2006.

### 16 See Table 10 for the maximum amount of degradates fo rmed in the soils and water (as percent of the applied 14 

### C-parent). Note that all are major degr adates, even though their relative amounts may vary in soils and water-sediment system s. Note also that NOA-436664 was not found in laboratory-scale aerobic soil metabolism studies, but that it was found in water-sediment systems and in the field.

In the terrestrial field studies, the highest amount of the cleavage products were found in the acidic Louisiana plots and were al so higher in the planted than in the bare-ground plot. After the third application, the degradate CGA-382997 in the 0-15 cm depth reached a maximum of 22.8 ppb in the sugarcane plot and 15.3 ppb in the bare ground plot after 90 days. For CGA-53052, a maximum of 12.98 ppb was found after 121 days (c ropped plot) and 9.91 after 90 days (bare ground plot). In the California study, residues of these degradates did not exceed 3.1 ppb in the 0-15 cm sampling depth. In California, the highes t amount of a bridge elimination/contraction product (CGA-368732) in the 0-15 cm depths was 8.3 in the cotton plot 21 days after the third application. This product was also the highest in the Louisiana plots ( 11 ppb 177 days after the third application).

### 17 Table 9. Chemical Names for Trifloxysulfuron-sodium and Its Major Transformation Products

Chemical Name and CAS Registry Number, if assigned Company Code Type of Transformation Product

IUPAC Name: 4,6-Dimethoxy-pyrimidin-2-ylamine CAS Name: 2-Pyrimidinamine,4,6-dimethoxyCAS #: 36315-01-2 CGA-53052 Cleavage product (pyrimidine ring) Other sulfonylurea herbicides generate this product

IUPAC Name: (4,6-Dimethoxy-pyrimidin-2-yl)-urea CAS Name: Urea, 4,6-dimethoxy-2- pyrimidinyl)- CAS #: 36315-01-2 CGA 294409 Cleavage product (pyrimidine ring) Other sulfonylurea herbicides generate this product. CGA-294409 may be considered as a precursor to CGA-53052

IUPAC Name: 3-(2,2,2-Trifluoro-ethoxy)-pyridine2-sulfonic acid amide. CAS Name: 2-Pyridinesulfonamide-3-(2,2,2- trifluoroethoxy)- CAS #: NA CGA-382997 Cleavage product (pyridine ring) This product is unique to trifloxysulfuron

IUPAC Name: 1-(4,6-Dimethoxy-pyrimidin-2-yl)-1-[3-(2,2,2-trifluoroethoxy)-pyridin2-yl)-urea CAS Name: Urea, N-(4,6-dimethoxy-2- pyrimidinyl)-N-[3-(2,2,2- trifluoroethoxy)-2-pyridinyl]- CAS #: NA CGA-368732 Formed by elimination of the sulfonyl group in the bridge, followed by rebridging. Thus, the bridge in CGA-368732 is shorter than parent’s.

This product is unique to trifloxysulfuron

Bridge elimination/contraction product

IUPAC Name : (4,6-Dimethoxy-pyrimidin-2-yl)-[3- (2,2,2-trifluoro-ethoxy)-pyridin-2- yl]-amine CAS Name : 2-Pyrimidinamine,4,6-dimethoxy-N- [3-(2,2,2-trifluoroethoxy)-2- pyridinyl]- CAS #: NA CGA-368733 Formed by elimination of the ureido group of CGA-368732, followed by rebridging. Thus, the bridge in CGA-368732 is shorter than in CGA-368732 This product is unique to trifloxysulfuron

Bridge elimination/contraction product

NOA-436664

IUPAC Name: 6-Methoxy-2-[3-(2,2,2-trifluoroethoxy)-pyridin-2-ylamino]- pyrimidin-4-ol CAS Name: 4-(1H)-Pyrimidinone, 6-methoxy-2- [[3-(2,22-trifluoroethoxy)-2- pyridinyl]amino]-

CAS #: NA NOA-436664 This is the mono-desmethoxy product of CGA-368733

This product is unique to trifloxysulfuron

Bridge elimination/contraction product

### 18 Table 10. Major Trifloxysulfuron-Sodium Environmental Transformation Products Trifloxysulfuron -sodium Transformation Products [ 14 C] Label Hydrolysis Aqueous Photolysis 2 Soil Photolysis 2 Aerobic
Soil Metabolism Anaerobic Aquatic Metabolism Aerobic Aquatic Metabolism

%max/day/pH 1 Maximum % of applied radioact ivity (day maximum occurred)

CGA 382997 Pyrimidine - - - - - -

Pyridine 64.0 (30 d; 4 52.5 (30 d;5) 4.8 (30 d; 7) 4.0 (30 d; 9) I: 5.3 (30 d) D: 5.1 (30 d) I: 10.1 (30 d) D: 17.2 (30 d) 54.1(273 d) 4.6 (270 d) 3 4.3 (100 d) 3

CGA 53052 Pyrimidine 61.1 (30 d; 4) 49.8 (30 d;5) 4.9 (30 d; 7) 3.3 (30 d; 9) I: 7.54 (30 d) D: 9.2 (30 d) I: 3.3 (21 d) D: 1.3 (14 d) 14.1(179 d) 3.8 (21 d) 4 3.2 (100 d) 4

Pyridine - - - - -

CGA 368733 Pyrimidine 2.7 (30 d; 4) 2.7 (30 d; 5) 8.1 (30 d; 7) 35.1 (30 d; 9) I: 6.4 (30 d) D: 3.4 (30 d) - 26.7 (365 d) 7.1 (181 d) 4 37.0 (100 d) 4

Pyridine 1.9 (30 d; 4) 5.1 (30 d; 5) 9.3 (30 d; 7) 29.8 (30 d; 9) I: 7.8 (30 d) D: 5.1 (26 d) I: 11.5 (30 d) D: 3.2 (30 d) 16.4 (365 d) 6.4 (270 d) 4 14.1 (100 d) 4

CGA 368732 Pyrimidine 35.9 (30 d; 4) 42.3 (30 d; 5) 53.0 (30 d; 7) 23.0 (30 d; 9 I: 45.9 (30 d) D: 51.1 (30 d) I: 25.5 (21 d) D: 29.0 (30 d) 21.8 (90 d) 20.1 (21 d) 3 30.9 (59 d) 3 14 (59 d) 4

Pyridine 34.8 (30 d; 4) 39.3 (30 d; 5) 51.0 (30 d; 7) 26.5 (30 d; 9) I: 46.1 (30 d) D: 49.0 (30 d) I: 6.2 (30 d) D: 1.1 (30 d) 12.5 (91 d) 16.7 (22 d) 3 19.2 (21 d) 3

CGA 294409 Pyrimidine - I: 2.0 (3 d) D: 5.8 (7 d) I: 2.4 (30 d) - - -

Pyridine - - - - -

NOA-436664 Pyrimidine - - I: 1.0 (30 d) - 45.7 (181 d) 4 7.7 (100 d) 4

Pyridine - - - - 37.2 (270 d) 4 21.5 (59 d) 4

1 Maximum percent of applied radioactivity, days after treatment maximum occurred, pH.

2 I = irradiated; D = Dark; Maximum percent of a pplied radioactivity and days after treatment.

3 Water fraction

4 Sediment fraction.

### 19 5. RECEPTORS

Table 11 and Table 12 provide a summary of the aquati c and terrestrial taxonomic groups, respectively, and the most sensitive surrogate sp ecies tested to characterize the potential acute and chronic ecological effects of trifloxysulfuron. The tables provi de a preliminary overview of the potential acute toxicity of trifloxysulfuron by provi ding the acute toxic ity classifications. Based on the available ecotoxic ity information, the organisms facing the greatest hazard are aquatic and terrestrial plants. No toxicity data were submitted or identified in the open literature for the trifloxysulfuron-sodium or its transf ormation products. Additional transformation product data from other sulfonylurea chemicals were not available to supplement the data submitted for transformation products of trifloxysulfuron-sodium ( i.e. , CGA-382997, CGA-368732). Note that CGA-362622 is the parent compound.

Four studies were identified in the OPPIN database for which a DER was not available; these studies are currently being pro cessed for review. A preliminary, cursory review of the endpoints suggests the possibility of a more sensitive endpoint for duckweed ( Lemna gibba ; MRID 47168201) than that provided in the tabl es below; the study author 7-day EC 50 

### for the parent compound is 5.3 x10 -5 

### mg a.i./L (NOAEC = 2.8 x 10 -5 

### mg a.i./L) with frond number as the most sensitive parameter. The endpoint is a tentative estimate until the value is formally vetted and recalculated by the reviewers ( Table 11 ).

The remaining studies, all with the parent compound, suggest reduced toxicity (MRID 47168202, non-vascular plant Anabaena flos-aquae , study author reported 120-hr cell density EC 50 

### of 0.27 mg a.i./L and NOAEC of 0.20 mg a. i./L) or equivalent toxicity (MRID 45371803, Lemna minor , study author reported 6-day frond number EC 50 

### of 0.00062 mg a.i./L; and, MRID 45371732, Apis mellifera , 48-hr acute oral LD 50 

### of >25  g a.i/bee) than the endpoints reported in the tables below. The endpoints are also tentativ e estimates until the values are formally vetted and recalculated by the reviewers.

Table 11. Summary of the Most Sensitive Endpoints from Aquatic Toxicity Stud ies for Trifloxysulfuron

Taxonomic

Group Study Type Surrogate Species and Test Material Toxicity Value (all units in

terms of measured active ingredient) MRID and Classification Acute Toxicity Classification

Freshwater fish 1 Acute 850.1075 Rainbow Trout –cold water species ( Oncorhynchus mykiss )

CGA-362622 96.3% a.i. LC 50 : >103 mg a.i./L

Most sensitive endpoint: none No sublethal effects reported. 45371713 Acceptable (limit test) Practically nontoxic

Rainbow trout ( Oncorhynchus mykiss )

Metabolite CGA-382997 99.5% a.i. LC 50 : >96.7 mg a.i./L

Most sensitive endpoint: none No sublethal effects reported. 45371715 Supplemental a No more than slightly toxic

### 20 Taxonomic

Group Study Type Surrogate Species and Test Material Toxicity Value (all units in

terms of measured active ingredient) MRID and Classification Acute Toxicity Classification

Rainbow trout ( Oncorhynchus mykiss )

Degradate CGA-368732 99.5% a.i. LC 50 : >104 mg a.i./L

Most sensitive endpoint: none No sublethal effects reported. 45371731 Acceptable (limit test) Practically nontoxic

Chronic (Early Life Stage) 850.1400 Rainbow Trout ( Oncorhynchus mykiss )

CGA-362622 96% a.i. NOAEC: 9.52 mg a.i./L LOAEC: >9.52 mg a.i./L

Most sensitive endpoint: none No sublethal effects reported. 45371721, 45893302 Supplemental b --

Estuarine/Marine fish Acute 850.1075 Sheepshead Minnow ( Cyprinodon variegatus )

CGA-362622 96.3% a.i. LC 50 : >103 mg a.i./L

Most sensitive endpoint: none No sublethal effects reported. 45371720 Acceptable (Limit test) Practically nontoxic

Freshwater invertebrates Acute 850.1010 Water Flea ( Daphnia

magna )

CGA-362622 96.3% a.i. EC 50 :>108 mg a.i./L

Most sensitive endpoint: none No sublethal effects reported. 45371716 Acceptable (Limit test) Practically nontoxic

Water Flea ( Daphnia

magna )

Metabolite CGA-382997 99.5 % a.i. EC 50 :>99.5 mg a.i./L

Most sensitive endpoint: none No sublethal effects reported. 45371717 Acceptable (Limit test) Practically nontoxic

Water Flea ( Daphnia

magna )

Degradate CGA-368732 99.5 % a.i. EC 50 :>119 mg a.i./L

Most sensitive endpoint: none. 5% mortality in second highest

test conc. Sublethal effects: quiescence,

extraneous material on organisms 45371730 Acceptable Practically nontoxic

### 21 Taxonomic

Group Study Type Surrogate Species and Test Material Toxicity Value (all units in

terms of measured active ingredient) MRID and Classification Acute Toxicity Classification

Chronic 850.1300 Water Flea ( Daphnia

magna )

CGA-362622 96.0% a.i. NOAEC: 0.549 mg a.i./L LOAEC: 1.23 mg a.i./L

Most sensitive endpoint: Reproduction (#of offspring/repro day) 45371722 Acceptable --

Estuarine/Marine invertebrates Acute – shell deposition study 850.1025 Eastern Oyster ( Crassostrea virginica )

CGA-362622 96.3% a.i. EC 50 : >103 mg a.i./L NOAEC: 103 mg a.i./L

Most sensitive endpoint: none No sublethal effects reported. 45371719 Acceptable (Limit test) Practically nontoxic

Acute – shrimp 850.1035 Mysid Shrimp ( Mysidopsis bahia )

CGA-362622 96.3% a.i. LC 50 : 60.1 mg a.i./L NOAEC: 9.16 mg a.i./L

Most sensitive endpoint: mortality No sublethal effects reported. 45371718 Acceptable Slightly toxic

Aquatic plants and algae Nonvascular 850.4500 Green alga ( Selenastrum capricornutum )

CGA-362622 96% a.i. EC 50 : 0.0065 mg a.i./L NOAEC: 0.00113 mg a.i./L

Most sensitive endpoint: cell density. 45371725 Acceptable --

Nonvascular 850.4500 Green alga ( Selenastrum capricornutum )

Degradate CGA-368732 99.5% a.i. EC 50 : 23 mg a.i./L NOAEC: 6.8 mg a.i./L

Most sensitive endpoint: cell density. 45371729 Supplemental c

### 22 Taxonomic

Group Study Type Surrogate Species and Test Material Toxicity Value (all units in

terms of measured active ingredient) MRID and Classification Acute Toxicity Classification

Nonvascular 850.4500 Green alga ( Pseudokirchneriella subcapitata )

Metabolite CGA-382997 99.5% a.i. EC 50 : >95.85 mg a.i./L

Most sensitive endpoint: none. No abnormalities observed. 2 45371727 Supplemental c

(Limit test) --

Vascular 850.4400 Duckweed ( Lemna gibba )

CGA-362622 93 % a.i. EC 50 : 0.000240 mg a.i./L NOAEC: 0.00001024 mg a.i./L

Most sensitive endpoint: frond number 45371802 Acceptable

--

Duckweed ( Lemna gibba )

CGA-362622 98.1 % a.i. Tentative values: EC 50 : 0.000053 mg a.i./L NOAEC: 0.000028 mg a.i./L

Most sensitive endpoint: frond number 47168201 In review

1 Freshwater fish represent surrogat es for aquatic-phase amphibians.

2 The 72-hour percent inhibition in cell density in the mean measured 95.85 mg a.i./L treatment group was -45%, compared to the control.

a Several guideline deviations, collectively, do not allow th e study to be considered acceptable by USEPA criteria.

b A LOAEC was not determined and the raw data for growth was not submitted; only mean values for each replicate instead of the value for each individual were provided.

c Numerous deviations from US EPA guideline recommendations. Most importantly, study was conducted for 72- hours, which is reviewed as a Tier I study.

Table 12. Summary of the Most Sensitive Endpoints fr om Terrestrial Toxicity St udies for Trifloxysulfuron

Taxonomic

Group Study Type Surrogate Species

and Test Material Toxicity Value (all units in terms of

measured active ingredient) MRID and Classification Acute Toxicity Classification

Birds 1 Acute 850.2100 Mallard Duck ( Anas platyrhynchos )

CGA-362622 96.3% a.i. LD 50 : >2250 mg a.i./kgbw

No mortality. No sublethal effects reported. Regurgitation in one female. 45371707 Acceptable

(gavage) Practically nontoxic 2

### 23 Taxonomic

Group Study Type Surrogate Species

and Test Material Toxicity Value (all units in terms of

measured active ingredient) MRID and Classification Acute Toxicity Classification

Sub-acute dietary 850.2200 Mallard Duck ( Anas platyrhynchos )

CGA-362622 96.3% a.i. LC 50 : >5800 mg a.i./kg

No mortality. No sublethal effects reported. 45371709 Acceptable Practically nontoxic 2

Chronic 1-gen repro 850.2300 Mallard Duck ( Anas platyrhynchos )

CGA-362622 96 % a.i. NOAEC: 106 mg a.i./kg-diet LOAEC: 201 mg a.i./kg-diet

Adult parameters not affected. Most sensitive endpoint: # of hatchlings/live 3- wk embryos and hatchling survival/eggs

set 45371711 Acceptable --

Mammals Acute Oral 870.1100 Laboratory rat ( Rattus norvegicus )

CGA-362622 95.7% a.i. LD 50 : >5,000 mg a.i./kg-bw

Mortality (2/5 females). No adverse effect on body weight gain. Sublethal effects: piloerection, hunched posture hypoactivity, dyspnea. 45371923 Acceptable (gavage) Practically nontoxic 2

Acute Oral 870.1100 Laboratory rat ( Rattus norvegicus )

CGA-362622 75% a.i. (TEP) LD 50 : >5,000 mg form/kg-bw LD 50 : >3,750 mg a.i./kg-bw

No mortality, no adverse effect on body weight gain. No sublethal effects. 45371924 Acceptable (Limit study)

(gavage) Practically nontoxic 2

Acute Oral 870.1100 Laboratory rat ( Rattus norvegicus )

CGA-362622, 0.77% Prometryn, 79.2% (TEP) LD 50 : >2,000 mg form/kg-bw LD 50 : >15.4 mg a.i./kgbw

No mortality. Body weight gain. Sublethal effects: slight piloerection, slightly reduced activity, slightly hunched posture. Normal by day 3 post treatment. 45762303 Acceptable (Limit study)

(gavage)

### 24 Taxonomic

Group Study Type Surrogate Species

and Test Material Toxicity Value (all units in terms of

measured active ingredient) MRID and Classification Acute Toxicity Classification

Acute Inhalation (4-hr) 870.1300 Laboratory rat - Wistar ( Rattus norvegicus )

CGA-362622, 0.78% Prometryn, 79.3% LC 50: > 5.14 mg form/L LC 50: > 0.04 mg a.i./L

No mortality. Body weight gain. Sublethal effects: wet fur, reduced breathing rate, salivation, reduced response to sound, hunched posture, piloerection, chromodaccryorrhea, stains around nose, upper respiratory tract irritation, decreased activity, reduced foot withdrawal reflex, tremors. Recovery by day 3. Pelvic dilatation and speckled thymus at

necropsy. 45762305 Acceptable (Limit study) --

### 25 Taxonomic

Group Study Type Surrogate Species

and Test Material Toxicity Value (all units in terms of

measured active ingredient) MRID and Classification Acute Toxicity Classification

Chronic 2-gen repro 870.3800 Laboratory rat ( Rattus norvegicus )

CGA-362622 94.6% a.i. Parental Toxicity NOAEL: 1000 ppm(78.8/83.5 mg/kgbw/day m/f) LOAEL: 8000 ppm (631/676.4 mg/kg-bw /day m/f) Endpoint: decreased body wt, body wt gain, food consumption in P and F 1 m & f

Offspring Toxicity NOAEL: 1000 ppm (78.8/83.5 mg/kg-bw /day m/f) LOAEL: 8000 ppm (631/676.4 mg/kg-bw /day m/f) Endpoint: decreased body wt, body wt gain, spleen and thymus wts in F 1 and F 2 pups, increased vaginal patency in F 1 pups

Reproductive performance NOAEL: 12,000 ppm(968.3/1029.6 mg/kgbw /day m/f) LOAEL: Not observed Endpoint: N/A 45372007 (definitive) 45372023 (range finding)

Acceptable --

Insects Acute

contact 850.3020 Honey bee ( Apis mellifera L. )

CGA-362622 96.3% a.i. LD 50: >25 μg a.i./bee

No mortality or sublethal effects reported. 45371728 Acceptable (Limit test) Practically nontoxic 2

Terrestrial plants Vegetative Vigor (Tier II) 850.4150 Dicot – Radish ( Raphanus sativus )

CGA-362622 75.2% a.i. (TEP) NOAEC = 0.00002 lbs a.i./acre IC 25 = 0.000009 lbs a.i./acre Endpoint: Shoot dry weight 45371734 Acceptable --

Monocot – Ryegrass ( Lolium perenne )

CGA-362622 75.2% a.i. (TEP) NOAEC = 0.0059 lbs a.i./acre EC 25 = 0.0056 lbs a.i./acre Endpoint: Shoot dry weight 45371734 Acceptable --

### 26 Taxonomic

Group Study Type Surrogate Species

and Test Material Toxicity Value (all units in terms of

measured active ingredient) MRID and Classification Acute Toxicity Classification

Seedling Emergence (Tier II) 850.4100 Dicot – Lettuce ( Latuca sativa )

CGA-362622 75.2% a.i. (TEP) NOAEC = 0.0007 lbs a.i./acre EC 25 = 0.0006 lbs a.i./acre Endpoint: Shoot dry weight 45371734 Acceptable --

Monocot – Ryegrass ( Lolium perenne )

CGA-362622 75.2% a.i. (TEP) NOAEC = 0.0014 lbs a.i./acre IC 25 = 0.0019 lbs a.i./acre Endpoint: Shoot dry weight 45371734 Acceptable --

1 Birds represent surrogates for terrestrial-phase amphibians and reptiles.

2 Acute Oral (avian/mammal): Based on LD 50 (mg/kg) <10 very highly toxic; 10-50 highly toxic; 51-500 moderately toxic; 501-2000 slightly toxic; >2000 practically nontoxic

3 Based on acute contact LD 50 ( μ g a.i./bee) <2 highly toxic; 2-10.99 moderately toxic; ≥ 11 practically non-toxic

4 However, there was a statistically significant increase in num ber of eggs cracked/eggs laid at 54 mg a.i./kg, but not at 106 or 201 mg a.i./kg.



### Effects of Trifloxysulfuron-so dium on Plant Reproduction

EFED's Plant Technical Team (PTT) conducted an analysis of available SU plant reproduction data from the open literature and the registrant-submitted data for chlorsulfuron and concluded that data from the vegetative vigor guidelin e (850.4150) study are suffi ciently protective of potential impacts to plant reprodu ction. Acetolactate synthase (ALS ) inhibitors primarily affect metabolically-active meristem tissues. When pl ants are exposed at a young, vigorously growing life-stage, effects are expressed primarily as inhibition of vegetative growth ( i.e. biomass, shoot length). As plants mature these effects are less pronounced. However, as plants enter their reproductive life-stage, the metabolically active tissue will include flower and seed production. Plants exposed to SU herbicides during the repr oductive life stage are like ly to exhibit adverse effects on reproduction, generally expressed as reduced seed number or reduced seed weight. Based on the latest data analysis, these effects are expected to occur at similar concentrations to those effects determined in the guideline vegeta tive vigor studies (850.4150) so further data are not requested at this time.

Degradate Toxicity

Six effects studies on two degradat es of trifloxysulfuron-sodium ar e available. Each of the two degradates (CGA-382997 and CGA-368732, both of wh ich do not retain the SU bridge) has three studies, one each on rainbow trout, Daphnia , and green algae (see Table 11 ). The data indicate that these degradates are likely equa lly (given that all endpoints are non-definitive for fish and daphnia) or less toxic (t o the green algae) than the parent is. For example, comparing the only definitive endpoints available for the green algae indicates that the degradate CGA-368732 is far less toxic (EC 50 

### : 23 mg a.i./L; MRID 45371729) than is the parent (EC 50 

### : 0.0065 mg a.i./L)

### 27 to this organism. Additional data on the remaini ng degradates of trifloxysulfuron-sodium are not available to supplement these data, even though some of the remaining transformation products are also generated by degradation of other sulfonylurea herbicides ( i.e. , CGA-53052 [ADMP] and CGA-294409; see Table 9 ). Furthermore, the degradates, CGA-368733 and 436664, were not included in the HED residues of concern because of their much lower mobility (K oc 

### values: 875-22817 ml/g oc 

### and 650-1925 ml/g oc 

### , respectively, see Table 8 ). Given the available data, degradates with an intact sulf onyl urea bridge (-NH-CO-NH-SO2-) w ill be considered as part of the total toxic residues (NOA-440735 and CGA-292230) and not assessed individually. Additional comparison of actual a nd ECOSAR 1.1 calcula ted toxicity endpoints indicate that several degradates may be more toxic to fr eshwater fish and i nvertebrates (NOA-436664, CGA246186, NOA-440735, and CGA-368733) than is the parent compound (see Appendix D ). However, upon comparison of ECOSAR-generated endpoints for these degradates (from 0.95 to 31 mg/L) to a GENEEC-generated peak EEC (0.0046 mg/L), under the assumption of no degradation of the parent, at a single application rate of 0.028 lb a.i./A applied 3x with a 14 day interval, and an average K d 

### of 0.595mL/g, the peak EEC is far less than 5% ( i.e. , the aquatic listed species LOC) of the calcula ted endpoint concentrations (0.01 to 0.5%). Therefore, with the exception of NOA-440735 (which contains the SU bridge), the remainin g degradation products will not be considered in risk assessment exp licitly and no additional degradate data will be recommended.

Ecological Incidents

A search of the Ecological Incident Informati on System (EIIS) database showed one “Possible” (I015713-081) and one “Probable” (I020283-014) trifloxysulfuron inci dent affecting turf from ground, broadcast applications of Monument 75 WG, and imp acting 0.5 acre from direct treatment (registered use) and 35 acres from carryover (unknown legality of product use), respectively, in South Carolina.

In the Incident Data System (IDS) database, registrants reported 1 aggregate plant damage incident (015713-00112) associated with trifloxysulfuron-sodi um use (Envoke emulsifiable concentrate, Reg. No. 100-1132) between November 1, 2003 and October 31, 2004.

A search of the Avian Incident Monitoring Sy stem (AIMS) database did not provide any additional incident data.

6. EXPOSURE PATHWAYS OF CONCERN

The environmental fate properties of trifloxysulfuron-sodium 

### indicate that direct spray, spray drift, leaching to groundwater, and runoff represent pote ntial transport mechanisms. These pathways may result in a wide range of potential aqua tic and terrestrial e xposure scenarios.

The conceptual model used to depict the potentia l ecological risk associated with the use of trifloxysulfuron-sodium and de gradates (the stressors) a ssumes that as a pesticide, trifloxysulfuron-sodium can advers ely affect terrestrial and aquatic organisms (the receptors) if environmental concentrations exceed toxic threshol ds as a result of application according to the label directions. Ecological receptors that may pot entially be exposed to trifloxysulfuron-sodium

### 28 and degradates include terrestri al and semi-aquatic wildlife ( e.g. , mammals, birds, terrestrialphase amphibians and reptiles), terrestrial and se mi-aquatic plants, and te rrestrial invertebrates ( e.g. , honey bees). Additionally, given the mobility of trifloxysulfuron-sodium and degradates, aquatic organisms ( i.e. , freshwater and estuarine/marine fi sh and invertebrates, aquatic-phase amphibians, and aquatic plants) are potential rece ptors in adjacent water b odies through off-site transport of trifloxysulfuron-sodium from the a pplication site through runoff, erosion, and spray drift.

The results of running the SIP and STIR models are presented in APPENDIX B and APPENDIX C , respectively. While the SIP model suggests that there are potential concerns for both mammals and birds from exposure via drin king water, the model does not perform well with chemicals that have a high aqueous solubility and have low toxicity to these organisms. Furthermore, the acute effects endpoints were based on non-definitive endpoints, which implies low toxicity to birds and mammals; the chronic endpoints for these taxa were definitive. This route of exposure is not likely to be significant enough to cause c oncern. The analysis with STIR indicates low likelihood of risk to birds or mammals th rough inhalation of trifloxysulfuronsodium.

7. ANALYSIS PLAN

In order to address the risk hypot hesis, the potential for adverse effects on the environment will be estimated. The use pattern, environmental fa te, and ecological effect s of trifloxysulfuronsodium will be characterized and integrated to assess the risks. This will be accomplished using a risk quotient (ratio of exposure concentration to effects concentration) approach. Although risk is often defined as the likelihood and magnitude of adverse ecologi cal effects, the risk quotientbased approach does not provide a quantitative estimate of likelihood and/or magnitude of an adverse effect. However, as outlined in th e Overview Document (USEPA 2004), the likelihood of effects to individual organisms from particular uses of trifloxysulfuron-sodium may be estimated using the probit dose-response slope and either the level of concern (discussed below) or the actual calculated risk quotient value.

Ecological Risk Assessment



## Measures of Exposure

In order to estimate ri sks of trifloxysulfuron exposure to aquatic and terrestrial organisms, all exposure modeling and resulting risk conclusion s will be made based on maximum application rates, application methods, and any mitigation m easures specifically indicated on the label. The models that will be used to predict the esti mated environmental concentrations (EECs) of trifloxysulfuron are discussed on OPP’s model website. 6

6 http://www.epa.gov/opp00001/science/models_pg.htm

### 29 Aquatic Exposure

Models used for drinking water and aquatic expos ure estimates include: PRZM (Pesticide Root Zone Model) and EXAMS (EXposure Analysis Modeling System), PRZM-Groundwater (GW) and SCI-GROW. The modeling of drinking water and aquatic exposure w ill use the total toxic residue approach (TTR) in order to incl ude both parent and degradation products.

The Health Effects Division (HED) determined that the residues of concern in drinking water are parent trifloxysulfuron-sodi um, CGA-053052, CGA-382997, and CGA-368733 7 

### . For the ecological assessment, EFED will use the to tal toxic residues including the parent trifloxysulfuron-sodium, and two other sulfonyl urea degradates, CGA-292230, and NOA440735, on the basis of ECOSAR 1.1 effects data comparisons (see Appendix D ). EFED will use standard available models 8 

### to evaluate potential exposure to pesticides in surface water (PRZM and EXAMS), and ground water (PRZM-GW ) and SCI-GROW sources as described at http://www.epa.gov/pesticides /science/models_db.htm

. The versions used by the Agency at the time the risk assessment is completed will be used in the assessment. Because the earlier drinking water assessment (Table 5) for parent trifloxysulfuron and the degradates CGA-053052, CGA-382997, and CGA-368733 did not incl ude modeling using PRZM-GW ( i.e. , the assessment predates the availability of the model), the drinking water assessment will be updated following current guidelines.

The drinking water and aquatic exposure assessments will also include available surface and ground water monitoring data from Federal, Stat e, and other sources w ith consideration of changes in use patterns that may have occurred.

These sources include:

 

### The United States Environmental Protect ion Agency (USEPA) STORET Database ( http://www.epa.gov/storet/dbtop.html )

 

### The United States Geological Survey (U SGS) National Water-Quality Assessment (NAWQA) Program Data Warehouse ( http://infotrek.er.usgs.gov /traverse/f?p=NAWQA:HOME:1405517206944567 )

 

### The USGS National Stream Quality A ccounting Network (NASQAN) program ( http://water.usgs.gov/nasqan /)

 

### California Department of Pesticide Regulation (DPR) Surface Water Database ( http://www.cdpr.ca.gov/docs/ emon/surfwtr/surfdata.htm )

Terrestrial Exposure

Exposure to terrestrial organism s will use the following models: AgDrift, AgDisp, T-REX, and TerrPlant. The terrestrial exposure assessments will consider the parent, trifloxysulfuronsodium, as well as the two sulfonyl-urea de gradate/transformation products, CGA-292230, and

8 PRZM and EXAMS are Tier II models used to estimate e nvironmental exposure concentrations in surface water. A

description of these models and the guidelines for selecting input parameters can be found at http://www.epa.gov/oppefed1/models/water/

### 30 NOA-440735, on the basis of ECOSAR 1.1 effects data comparisons (see Appendix D ). The approach assumes comparable toxicity due to clos ely related chemical structure. The degradates will not be considered individually.



## Measure of Effects

Ecological effects data are used as measures of di rect and indirect effect s to biological receptors. Data are typically obtained from registrant-submitte d studies or from literature studies identified by ECOTOX. The ECOTOX database provides more ecological effects data in an attempt to bridge existing data gaps. ECOTOX is a source fo r locating single chemical toxicity data and potential chemical mixture toxicity data for aqua tic life, terrestrial plants, and wildlife. ECOTOX was created and is maintained by the USEPA, Office of Research and Development, and the National Health and Environmental Effects Research Laboratory's Mid-Continent Ecology Division.



## Integration of Exposure and Effects

Risk characterization is the integration of e xposure and ecological effects to determine the potential ecological risk from the use of pestic ides and the likelihood of direct and indirect effects to non-target organisms in aquatic and terrestrial habitats. For the assessment of risks, the risk quotient (RQ) method is used to compare exposure and measured toxicity values. EECs are divided by acute and chronic toxicity values. The resulting RQs are then compared to the Agency’s Levels of Concern (LOCs) (USEPA 20 04). These criteria will be used to indicate when trifloxysulfuron use, as directed on the labe l, has the potential to cause adverse direct or indirect effects to non-target organisms. In add ition, incident data from the EIIS, IDS, and AIMS will be considered as part of the risk characteri zation. Degradates will be considered within the context of a total toxi c residues approach and not assessed individually.

8. ENDANGERED SPECIES ASSESSMENTS

Consistent with the Agency’s responsibility under the Endangered Species Act (ESA), the Agency will evaluate exposure and potential risks to federally listed threatened and/or endangered (listed) species from registered uses of pesticides in regist ration review. The process for evaluating potential risks to list ed species is further described at http://www.epa.gov/oppfead1/enda nger/litstatus/riskasses.htm

.

9. ENDOCRINE DISRUPTOR SCREENING PROGRAM

Trifloxysulfuron-sodium was not included in the first group of 67 chemicals issued an order to conduct Tier 1 EDSP testing. For additional information the EDSP program, visit http://www.epa.gov/endo/

.

### 31 10. PRELIMINARY IDENTIFICATIO N OF DATA GAPS

Environmental Fate

Table 13 identifies the environmental fate studies submitted by the registrant, as well as study classifications and whether or not additional data are needed in order to support the registration review exposure assessments. Rationale for the additional data requested is also presented.

Table 13. Submitted Environmental Fate Data for Chemical Trifloxysulfuron-Sodium and Degradates

OCSPP Guideline Data Requirement Submitted Studies (MRID) Study Classifications Are data needed to conduct risk assessment? Comments

835.2120 Hydrolysis 45371804 45371805 Acceptable No

835.2240 Aqueous photolysis 45371806 45371807 Acceptable No

835.2410 Soil photolysis 45371808 45371809 Acceptable No

835.4100 Aerobic soil metabolism 45371810 45371811 Acceptable No Data are adequate for Total Toxic residue methods.

835.4200 Anaerobic soil metabolism No data submitted - No a While anaerobic soil metabolism data are required according the 40 CFR 158.1300, these data are not typically used in exposure modeling as it is not expected to have a significant influence on estimates of residues in surface water. In the absence of these data, it will be assumed that no anaerobic degradation occurs ( i.e. , degradates are stable); however, these data may help to refine exposure assessments.

835.4300 Aerobic aquatic metabolism 45371814 45371815 Acceptable No Data are adequate for Total Toxic residue methods

835.4400 Anaerobic aquatic metabolism 45371812 45371813 Acceptable No Data are adequate for Total Toxic residue methods

835.1230 835.1240 Adsorption/ desorption and leaching Parent 45371817 45371818 45371825 Degradates

- 45371821 45371823 45371820 45371824 45371816 Acceptable

Acceptable No Trifloxysulfuron-Sodium Column leaching Aged column leaching Batch equilibrium Degradates

Batch equilibrium

CGA-382997 CGA-53052 CGA-368732 CGA-368733 NOA-436664

835.1410 Volatility – laboratory No data submitted Waived No Waiver Request November 7, 2002 DP D284113

### 32 OCSPP Guideline Data Requirement Submitted Studies (MRID) Study Classifications Are data needed to conduct risk assessment? Comments

835.6100 Terrestrial field dissipation 45371827 45371828 45371829 Acceptable No Long-term desorption Louisiana California

850.6100 Analytical method in soil 45371831 No

835.6200 Aquatic field dissipation No data submitted - No No aquatic uses.

850.6100 Analytical method in water 47534701 47534702 Yes Submitted no independent lab evaluation

165-4 (850.1730) Fish bioconcentration Waived Waiver Request November 7, 2002 DP D284114

a 

### Not required but may be helpful if exposure concentrations for drinking water require refinements.

Effects

Table 14 and Table 15 identify the ecological effects studi es, as well as study classifications and whether or not further data are needed in or der to support risk assessment. Rationale for the additional data requested is presented below the tables.

Table 14. Submitted Aquatic Ecological Effects Data for Trifloxysulfuron-sodium and its Degradates

OCSPP Guideline Data Requirement Submitted Studies (MRID) Study Classifications Are data needed to conduct

risk assessment? Comments

850.1010 Freshwater invertebrate acute toxicity 45371716 Acceptable

No 45371717

CGA-382997 Acceptable

45371730

CGA-368732 Acceptable

850.1025 850.1035 850.1045 850.1055 Saltwater invertebrate acute toxicity 45371719 Acceptable

No 45371718 Acceptable

850.1075 Freshwater fish acute toxicity 45371713 Acceptable

No 45371714 Acceptable

45371715

CGA-382997 Supplemental

45371731

CGA-368732 Acceptable

850.1075 Saltwater fish acute toxicity 45371720 Acceptable No

### 33 OCSPP Guideline Data Requirement Submitted Studies (MRID) Study Classifications Are data needed to conduct

risk assessment? Comments

850.1300 Freshwater invertebrate life cycle 45371722 Acceptable No

850.1350 Saltwater invertebrates life cycle -- -- No A majority of the available fish and invertebrate studies indicate low toxicity of trifloxysulfuron to these taxa; the value of these additional data to the ecological risk assessment is likely low.

850.1400 Freshwater fish early-life stage 45371721, 45893302 Supplemental No --

850.1400 Saltwater fish early-life stage

-- -- No A majority of the available fish and invertebrate studies indicate low toxicity of trifloxysulfuron-sodium to these taxa; the value of these additional data to the ecological risk assessment is likely low. 850.1500 Fish life cycle

-- -- No A majority of the available fish and invertebrate studies indicate low toxicity of trifloxysulfuron-sodium to these taxa; the value of these additional data to the ecological risk assessment is likely low. 850.4400 Aquatic plant growth: Tier II vascular plants 45371723 Supplemental

No

45371802 Acceptable

850.4500 Aquatic Plant Growth: Tier II algae 45371724 Acceptable

No 45371725 Acceptable

45371729

CGA-368732 Supplemental

45371726 Acceptable

45371727

CGA-382997 Supplemental

850.1735 850.1740 Whole Sediment Testing -- -- No

### 34 Table 15. Submitted Terrestrial Ecological Ef fects Data for Trifloxysulfuron-sodium

OCSPP Guideline Data Requirement Submitted Studies (MRID) Study Classifications Are data needed for risk assessment? Comments

850.2100 Avian oral toxicity 45371707 Acceptable

No Although EPA does not have acute oral toxicity data on a passerine species, based on the available toxicity data, risk to passerine species is unlikely to exceed levels of concern. 45371708 Acceptable

850.2200 Avian dietary toxicity 45371709 Acceptable No 45371710 Acceptable

850.2300 Avian reproduction 45371711 Acceptable No 45371712 Acceptable

Nonguideline Avian inhalation -- -- No

850.3020 Honey bee

acute contact toxicity 45371728 Acceptable No

Honey bee acute oral toxicity -- -- No

850.3030 Honey bee residue on foliage -- -- No

850.3040 Field testing for pollinators -- -- No

850.4100 Terrestrial plant toxicity: Tier II seedling

emergence 45371734 Acceptable No

850.4150 Terrestrial plant toxicity: Tier II vegetative vigor 45371734 Acceptable No



### Additional effects information that would be useful to the Agency include ecological incidents (non-target plant damage and avian, fish, reptili an, amphibian and mammalian mortalities) not already reported to the Agency.

References USEPA, 2008. Trifloxysulfuron-Sodium: Hu man Health Risk Assessment for the Requested Use on Sports Fields and Reside ntial Turfgrass. Health Effects Division. DP Barcode 352260. November 12, 2008.

### 35 APPENDIX A. STRUCTURES, CHEMICAL NAMES, and ABBREVIATIONS

### 36

### 37

### 38

### 39 APPENDIX B SIP ANALYSIS

Table 1. Inputs

Parameter Value
Chemical name Trifloxysulfuron Solubility (in water at 25°C; mg/L) 25700

Mammalian LD 50 (mg/kg-bw) 15.4 Mammalian test species laboratory rat Body weight (g) of "other" mammalian species

Mammalian NOAEL (mg/kg-bw) 78.8 Mammalian test species laboratory rat Body weight (g) of "other" mammalian species

Avian LD 50 (mg/kg-bw) 2250 Avian test species mallard duck Body weight (g) of "other" avian species Mineau scaling factor

Mallard NOAEC (mg/kg-diet) 106 Bobwhite quail NOAEC (mg/kg-diet) 201 NOAEC (mg/kg-diet) for other bird species Body weight (g) of other avian species NOAEC (mg/kg-diet) for 2nd other bird species Body weight (g) of 2nd other avian species

Table 2. Mammalian Results

Parameter Acute Chronic Upper bound exposure (mg/kg-bw) 4420.4000 4420.4000 Adjusted toxicity value (mg/kg-bw) 11.8451 60.6099 Ratio of exposure to toxicity 373.1847 72.9320

Conclusion* Exposure through drinking water alone is a potential

concern for mammals Exposure through drinking water alone is a potential

concern for mammals

Table 3. Avian Results

Parameter Acute Chronic Upper bound exposure (mg/kg-bw) 20817.0000 20817.0000 Adjusted toxicity value (mg/kg-bw) 177750.0000 5.2589 Ratio of exposure to acute toxicity 0.1171 3958.4085

Conclusion* Exposure through drinking water alone is a potential concern for birds Exposure through drinking water alone is a potential concern for birds

*Conclusion is for drinking water exposure alone. This does not combine all routes of ex posure. Therefore, when aggregated with other routes ( i.e ., diet, inhalation, dermal), pesticide exposu re through drinking water may contribute to a total exposure that has potential for effects to non-target animals.

### 40 APPENDIX C STIR Analysis Results 

# Input

Application and Chem ical Information

Enter Chemical Name Trifloxysulfuron Enter Chemical Use turf/lawn Is the Application a Spray? (enter y or n) y If Spray What Type (enter ground or air) ground Enter Chemical Molecu lar Weight (g/mole) 459.3329 Enter Chemical Vapor Pressure (mmHg) 9.75E-09 Enter Application Rate (lb a.i./acre) 0.079688 Toxicity Properties

Bird Enter Lowest Bird Oral LD 50 (mg/kg bw) 2250 Enter Mineau Scaling Factor 1.15 Enter Tested Bird Weight (kg) 1.58 Mammal
Enter Lowest Rat Oral LD 50 (mg/kg bw) 15.4
Enter Lowest Rat Inhalation LC 50 (mg/L) 0.04 Duration of Rat Inhalation Study (hrs) 4 Enter Rat Weight (kg) 0.35 

# Output Results Avian (0.020 kg ) Maximum Vapor Concentration in Air at Saturation (mg/m 3 ) 2.41E-04 Maximum 1-hour Vapor Inhalation Dose (mg/kg) 3.03E-05 Adjusted Inhalation LD 50 2.35E+01 Ratio of Vapor Dose to Adjusted Inhalation LD 50 1.29E-06 Exposure not Likely Significant Maximum Post-treatment Spray Inhalation Dose (mg/kg) 8.42E-03 Ratio of Droplet Inhalation Dose to Adjusted Inhalation LD 50 3.59E-04 Exposure not Likely Significant 

### Results Mammalian (0.015 kg ) Maximum Vapor Concentration in Air at Saturation (mg/m 3 ) 2.41E-04 Maximum 1-hour Vapor Inhalation Dose (mg/kg) 3.81E-05 Adjusted Inhalation LD 50 2.38E+00 Ratio of Vapor Dose to Adjusted Inhalation LD 50 1.60E-05 Exposure not Likely Significant Maximum Post-treatment Spray Inhalation Dose (mg/kg) 1.06E-02 Ratio of Droplet Inhalation Dose to Adjusted Inhalation LD 50 4.44E-03 Exposure not Likely Significant

### 41 APPENDIX D: Ecotoxicity data (where available) and ECOSAR 1.1 Output for Parent (CGA-362622) and degradat es (CGA-382997, CGA-368732, CGA-53052, CGA294409, CGA-368733, NOA-436664, CGA-292230, CGA-246186, NOA-440735 (M9))

Degradate Eco data ECOSAR data Organism/MRID Endpoint Organism/Chemical Endpoint* CGA-362622 (Parent) Trout/45371713 LC 50 >103 mg a.i./L FW Fish/amides LC 50 : 815.9 mg/L

FW Fish/ sulfonyl ureas LC 50 : 190.5 mg/L FW Fish/neutral organic LC 50 : 2283 mg/L Daphnia/45371716 EC 50 >108 mg a.i./L Daphnid/amides LC 50 : 348.5 mg/L Daphnid/ sulfonyl ureas LC 50 : 248 mg/L Daphnid/neutral organic LC 50 : 1019.4 mg/L Green algae/45371725 EC 50 : 0.0065 mg a.i./L Green algae/amides EC 50 : 15 mg/L

Green algae/ sulfonyl ureas EC 50 : 0.243 mg/L Green algae/neutral organic EC 50 : 940.6 mg/L CGA-382997 Trout/ 45371715 LC 50 >96.7 mg a.i./L FW Fish/halo ether-acid LC 50 : 61,253 mg/L FW Fish /neutral organic LC 50 : 1.4 x 10 5 mg/L Daphnia/ 45371717 EC 50 >99.5 mg a.i./L Daphnia/halo ether-acid 3 LC 50 : 10,997 mg/L Daphnia/neutral organic LC 50 : 53,651 mg/L Green algae/45371727 EC 50 >95.85 mg a.i/L Green algae/neutral organic EC 50 : 5,813 mg/L CGA-368732 Trout/ 45371731 LC 50 >104 mg a.i./L FW Fish /substituted urea LC 50 : 12.44 mg/L FW Fish /amide LC 50 : 4.63 mg/L FW Fish /halo ether LC 50 : 19.8 mg/L FW Fish /neutral organic LC 50 : 23.52 mg/L Daphnia/ 45371730 1 EC 50 >119 mg a.i./L Daphnia/substituted urea LC 50 : 17.3 mg/L Daphnia/amide LC 50 : 4.1 mg/L Daphnia/halo ether LC 50 : 5.59 mg/L Daphnia/neutral organic LC 50 : 15.85 mg/L Green algae/45371729 2 EC 50 : 23 mg a.i/L Green algae/substituted urea EC 50 : 0.201 mg/L Green algae/amide EC 50 : 0.36 mg/L Green algae/ neutral organic EC 50 : 11.6 mg/L CGA-53052 N/A N/A FW Fish /aniline (unhindered) LC 50 : 119 mg/L FW Fish /neutral organic LC 50 : 1,115 mg/L Daphnia/aniline (unhindered) LC 50 : 1.135 mg/L Daphnia/neutral organic LC 50 : 483.3 mg/L Green algae/aniline (unhindered) EC 50 : 3.14 mg/L

Green algae/neutral organic EC 50 : 446 mg/L CGA-294409 N/A N/A FW Fish/substituted urea LC 50 : 618 mg/L FW Fish/amides LC 50 : 1090 mg/L FW Fish/neutral organic LC 50 : 3,057 mg/L Daphnia/substituted urea LC 50 : 529 mg/L Daphnia/amides LC 50 : 324 mg/L Daphnia/neutral organic LC 50 : 1,236mg/L Green algae/substituted urea EC 50 : 15 mg/L Green algae/amides EC 50 : 12 mg/L Green algae/ neutral organic EC 50 : 1,137mg/L CGA-368733 N/A N/A FW Fish/neutral organic LC 50 : 16.36 mg/L Daphnia/neutral organic LC 50 : 10.5 mg/L Green algae/neutral organic EC 50 : 10.5 mg/L NOA-436664 N/A N/A FW Fish/phenols LC 50 : 13.52 mg/L FW Fish/neutral organic LC 50 : 56.12 mg/L Daphnia/phenols LC 50 : 6.3 mg/L Daphnia/neutral organic LC 50 : 34.2 mg/L Green algae/phenols EC 50 : 27 mg/L Green algae/neutral organic EC 50 : 32 mg/L

### 42 Degradate Eco data ECOSAR data Organism/MRID Endpoint Organism/Chemical Endpoint* CGA-292230 N/A N/A FW Fish/amides LC 50 : 816 mg/L FW Fish/ sulfonyl ureas LC 50 : 190.5 mg/L FW Fish/neutral organic LC 50 : 2283 mg/L Daphnia/ amides LC 50 : 348.5 mg/L Daphnia/ sulfonyl ureas LC 50 : 247.7 mg/L Daphnia/neutral organic LC 50 : 1019.4 mg/L Green algae/amides EC 50 : 15 mg/L Green algae/ sulfonyl ureas EC 50 : 0.243 mg/L Green algae/neutral organic EC 50 : 940.6 mg/L CGA-246186 N/A N/A FW Fish/anilines LC 50 : 401.4 mg/L FW Fish/poly phenols LC 50 : 96.3 mg/L FW Fish/ phenol amines LC 50 : 31 mg/L FW Fish/neutral organic LC 50 : 5669 mg/L Daphnia/ anilines LC 50 : 0.95 mg/L Daphnia/ poly phenols LC 50 : 1626 mg/L Daphnia/ phenol amines LC 50 : 1.5 mg/L Daphnia/neutral organic LC 50 : 2079 mg/L Green algae/ anilines EC 50 : 4.17 mg/L Green algae/ poly phenols EC 50 : 12 mg/L Green algae/ phenol amines EC 50 : 15 mg/L Green algae/neutral organic EC 50 : 1907 mg/L NOA-440735 (M9) N/A N/A FW Fish/aliphatic amines LC 50 : 1169.8 mg/L FW Fish/imides LC 50 : 131 mg/L FW Fish / amides LC 50 : 5564.5 mg/L FW Fish/ sulfonyl ureas LC 50 : 573.6 mg/L FW Fish/ neutral organic LC 50 : 15,643 mg/L Daphnia/ ali phatic amines LC 50 : 118 mg/L Daphnia/ imides LC 50 : 7.9 mg/L Daphnia/ amides LC 50 : 1147 mg/L Daphnia/ sulfonyl ureas LC 50 : 956 mg/L Daphnia/neutral organic LC 50 : 5722 mg/L Green algae/ aliphatic amines EC 50 : 152.5 mg/L Green algae/ imides EC 50 : 0.163 mg/L Green algae/ amides EC 50 : 36.33 mg/L Green algae/ sulfonyl ureas EC 50 : 0.28 mg/L Green algae/neutral organic EC 50 : 5248 mg/L

1 5% mortality in 2 n d highest dose

2 Cell density most sensitive endpoint

3 Acid moiety: Predicted values multiplied by 10 *FW fish value estimates from test duration of 96 hours, daphnia 48 hours, and green algae 96 hours.