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### fate and potential ecological e ffects of orthosulfamuron.

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# Problem Formulation for the Environmental Fate and Ecological Risk, Endangered Species, and Drinking Water Assessments

in Support of the Registration Review of Orthosulfamuron

Orthosulfamuron (CAS 213464-77-8)



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repared b y : Mary Clock-Rust, Biologist Katrina White, Ph.D., Biologist U. S. Environmental Protection Agency Office of Pesticide Programs
E nvironmental Fate and Effects Division
E nvironmental Risk Branch I V 1200 Pennsylvania Ave., NW
M

ail Code 7507P Washington, DC 20460 R eviewed by: 

### Cheryl Sutton, Ph.D., Environmental Scientist Thomas Steeger, PhD., Senior Biologist Marietta Echeverria, Branch Chief

December 1, 2011 O N CH 3


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### N H S N H N H O

O O

N N O CH 3



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### 2 Table of Contents

I. Purpose ................................................................................................................... .................... 5 II. Description of Regulatory Action .......................................................................................... .... 5 III. Conclusions from Previous Risk Assessments ........................................................................ 5 IV. Mechanism of Action ...................................................................................................... ........ 6 V. Overview of Pesticide Usage ............................................................................................... ..... 7 VI. Environmental Fate and Transport ........................................................................................ 10 A. Monitoring Data ............................................................................................................. 1 9 B. Clean Water Act ........................................................................................................... ....... 20 VII. Receptors ............................................................................................................... ............... 20 A. Effects to Aquatic Organisms ............................................................................................. 23 B. Effects to Terrestrial Organisms ......................................................................................... 25 C. Degradate Toxicity ........................................................................................................ ...... 27 D. Ecological Incidents ...................................................................................................... ...... 27
VIII. Evaluation of Non-definitive Toxicity Values ............................................................... 27 IX. Ecosystems Potentially at Risk ........................................................................................... ... 29 X. Assessment Endpoints ...................................................................................................... ....... 29 XI. Identification of Stressors of Concern ................................................................................... 29 XII. Conceptual Model ......................................................................................................... ........ 36 A. Risk Hypothesis ........................................................................................................... ....... 37 B. Conceptual Diagram ........................................................................................................ .... 37 XIII. Analysis Plan............................................................................................................ ............ 41 A. Measures of Exposure .................................................................................................... 42 1. Exposure to Aquatic Organisms in the Rice Paddy ......................................................... 42 2. Exposure to Terrestrial Animals via Residues on Food Items .......................................... 43 3. Exposure to Terrestrial An imals via Drinking Water ....................................................... 43 4. Exposure to Terrestrial Plants from Spray Drift ............................................................... 44 5. Exposure to Terrestrial Plants fr om Residues in Irrigation Water .................................... 44 6. Exposure to Aquatic Organism s based on Monitoring Data ............................................ 44 7. Exposure to Spray Drift .................................................................................................... 44
B. Measures of Effect ......................................................................................................... 44 C. Integration of Exposure and Effects ............................................................................... 45 1. Deterministic and Probabilistic Assessment Methods ..................................................... 46
D. Endangered Species Assessments .................................................................................. 46 E. Human Health Drinking Water Assessment ........................................................................ 46
F. Endocrine Disruptor Screening Program ........................................................................... 47 XIV. Preliminary Identification of Data Gaps .............................................................................. 48 A. Fate .......................................................................................................................... ....... 48 1. Rationales for Requesting Fate Studies .......................................................................... 50
B. Effects ....................................................................................................................... ...... 53 1. Rationales for Requesting Effects Studies ....................................................................... 55 2. Rationales for Not Requesting Effects Studies ................................................................ 56 3. Degradate Toxicity Data .................................................................................................. 58 4. Testing on Typical end-use products (TEP) .................................................................... 59 XV. Other Information Needs................................................................................................... ... 60

### 3 XV. References ............................................................................................................... ............. 61

List of Tables

Table 1. Summary of currently register ed products of orthosulfamuron. ...................................... 8 Table 2. Summary of physical-chemi cal properties of orthosulfamuron 1 

### .................................... 11 Table 3. Summary of other environmental fate a nd transport properties of orthosulfamuron. ... 12 Table 4. Summary of maximum amount of transf ormation products observed in fate studies. .. 19 Table 5. Most Sensitive Species Evaluate d for Potential Ecological Effects from Orthosulfamuron. ........................................................................................................... 21 Table 6. Comparison of Measured Toxicity Endpoints for Orthosulfamuron with Estimated Aquatic Toxicity Endpoints for DBS Acid, DBS amide, DB amine, and DOP amine (estimated using ECOSAR versioin 1).* ....................................................................... 34 Table 7. Summary of residues of concern for different classes of organisms. ............................ 35 Table 8. Summary of Submitted Environmental Fate Studies, Study Classifications and Data Gaps for Orthosulfamuron and Its Degradates .............................................................. 48 Table 9. Summary of Submitted Ecological Effects Studies and Data Gaps for Parent Orthosulfamuron ............................................................................................................ 53 Table 10. Summary of Submitted Ecologica l Effects Studies and Data Gaps for Orthosulfamuron Degradates ......................................................................................... 58

List of Figures

Figure 1. Acres Planted in Rice by County for Select ed States in the United States. Prepared by the National Agricultural Statistics Service (NASS) and downloaded from http://www.nass.usda.gov/Charts_an d_Maps/Crops_County/ar-pl.asp ......................... 9 Figure 2. Degradation Pathway of Orthosulfa muron (adapted from MRID 46588508, page 40). Abbreviations are defined in text above figure. ........................................................... 18 Figure 3. Structures of Orthosulfamur on and O-desmethyl orthosulfamuron ............................. 30 Figure 4. Structures of DOP urea and O-desmethyl DOP urea ................................................... 32 Figure 5. Structures of DBS Acid, DOP Amine, DBS Amide and DB Amine ........................... 34 Figure 6. Conceptual model depicting stressors, exposure pathways, and potential effects to aquatic organisms from the use of orthosulfamuron to rice. ........................................ 39 Figure 7. Conceptual model depicting stressor s, generic exposure pathways, and potential effects to terrestrial organisms (terrestrial plants, terrestrial invertebrates, and dietary routes of exposure for terrestri al vertebrates) from the us e of orthosulfamuron on rice.

.............................................................................................................................. ........ 40 Figure 8. Conceptual model depicting stress ors, drinking water a nd inhalation exposure pathways, and potential effects to terrestria l animals from the use of orthosulfamuron on rice. ...................................................................................................................... .... 41

List of Appendices

Appendix A. Supplemental Environmental Fate Information Appendix B. Summary of Relevant Phenyl Urea Toxicity Data a nd Comparison of Structures to

### 4 DOP Urea and o-desmethyl urea Appendix J. Identification of Transformation Products and Listing of the Maximum Amounts Observed in Fate Studies. Appendix C. ECOSAR Output Appendix D. Ecological Toxicity Summary for Aquatic and Terrestrial Organisms from Orthosulfamuron Appendix E. Results from Screening Imbib ition Program (SIP) and the Screening Tool for Inhalation Risk Assessment (STIR) Appendix F. Preliminary Estimated Environmenta l Concentration for the Parent and Degradates Using the Tier I Rice Model (version 1, May 8, 2007). Appendix G. Example T-Rex Input and Output for Orthosulfamuron. Appendix H. Example Terrplant (v. 1.2.2) Input and Output fo r Orthosulfamuron. Appendix I. List of Label Statements Rele vant to the Environmental Risk Assessment. Appendix J. Identification of Transformati on Products and Listing of the Maximum Amounts Observed in Fate Studies. Appendix K. Calculations for Gr ound Water Used for Irrigation Exposure Appendix L. Preliminary Estimate of Exposure a nd Risk to Terrestrial Animals for DOP urea and O-desmethyl DOP urea. Appendix M. Data Table for Non-Guideline Studies

### 5 

# I. Purpose

The purpose of this problem formulation is to pr ovide an understanding of the environmental fate and ecological effects of the registered uses of orthosulfamuron (1-(4,6-Dimethoxypyrimidin-2- yl)-3-[2-(dimethylcarbamoyl)phenylsu lfamoyl]urea). It is a systemic herbicide registered to control a variety of annual an d perennial broadleaf weeds and sedges in rice production (USEPA, 2010a). This document will provide a plan for analyzing data relevant to orthosulfamuron and for conducting environmental fate and ecological risk, endangered species, and drinking water assessments for its registered uses . Additionally, this problem form ulation is intended to identify data gaps, uncertainties, and potential assumptions used to address those uncertainties, relative to characterizing the ecologi cal risk associated with the regi stered uses of orthosulfamuron.



# II. Description of Regulatory Action

The Food Quality Protection Act of 1996 mandated the Environmental Protection Agency (EPA) to implement a new program for assessing the risks of pesticides, i.e ., Registration Review ( http://www.epa.gov/oppsrr d1/registration_review/ ). All pesticides distri buted or sold in the United States generally must be registered by EPA. The decision to register a pesticide is based on the consideration of scientific data and other factors showing th at it will not cause unreasonable risks to human health, workers, or the environment when used as directed on product labeling. The Registration Re view program is intended to en sure that, as the ability to assess risk evolves and as polic ies and practices change, all regi stered pesticides continue to meet the statutory standard of no unreasonab le adverse effects to human health and the environment. Changes in science, public policy, and pe sticide use practices will occur over time. Through the new Registration Review program, the Agency periodical ly reevaluates pesticides to ensure that as change occurs, products in the marketplace can be used safely.

As part of the implementation of the new Regist ration Review program pur suant to Section 3(g) of the Federal Insecticide, Fungi cide and Rodenticide Act (FIFRA ), the Agency is beginning its evaluation to determine whether orthosulfamur on continues to meet the FIFRA standard for registration. This problem formulation for the e nvironmental fate and ecological risk assessment chapter in support of the registra tion review is intended for the initial docket opening the public phase of the review process.



# III. Conclusions from Previous Risk Assessments

The Agency conducted a new chemical ecologi cal risk assessment and drinking water assessment on orthosulfamuron in 2006 and the assessments serve as a basis for this problem formulation. No other assessments on orthosul famuron have been completed in EFED. The assessments are briefly discussed below.

Ecological Risk Assessment In 2006, EFED completed a New Chemical ecologi cal risk assessment evaluating the potential risk posed by use of orthosulfamuron on rice at a maximum application rate of 0.0689 lbs active

### 6 ingredient (a.i.)/acre(A) for water dispersable granule applications and 0.0663 lbs a.i./A for the dry granule formulation (USEPA, 2006, D333514). The products could be applied by either ground or aerial application once per year. The screening level risk assessment identified the potential for direct effects to a quatic vascular plants, dicotyledonous (dicot) terrestrial plants, and monocotyledonous (monocot) terres trial plants. The risk assessment also highlighted the potential for indirect effects to all taxa due to direct effects on plants if the taxa rely on plants for food or habitat for some porti on of their life cycle.

Drinking Water Assessment A drinking water assessment was completed for the same use pattern as evaluated in the ecological risk assessment (USEPA, 2006, 330828). Estimated drinking water concentrations (EDWCs) in surface water were estimated using the Interim Rice model and ground water concentrations were estimated using Sci-Grow (version 2.3). Peak EDWC were 40.5 μg/L in surface water and 0.611 μg/L in ground water. The annual mean EDWCs were <40.5 μg/L and <0.611 μg/L in surface water and groundwater, respect ively. Whether these values will result in a risk concern is determined by comparing thes e values to toxicity endpoints to determine whether exposure is likely to exceed levels were effects are observed. Because of the absence of data on orthosulfamuron, the e ffects of drinking water treatmentwere not considered in the

assessment.



# IV. Mechanism of Action

Orthosulfamuron is associated with the followi ng chemical classes: pyrimidinylsulfonylurea (Wood, 2009), sulfonylureas (ISAGRO), and sulf amoylurea (USEPA, 2006, D3 33514). It is a systemic post-emergent herbicide registered to control a variety of annual and perennial broadleaf weeds and sedges in ri ce production (USEPA, 2010a). Its mode of action for plants is through inhibition of the plant enzyme acetolacta te synthase (ALS inhibitor), also known as acetohydroxyacid synthase (Ware and Whitacre, 2004). Inhibition of this enzyme blocks biosynthesis of the branch chain amino acids valin e, leucine, and isoleucine involved in plant growth and leads to plant death. It is applied early post-emergence to the weed and is rapidly taken up into leaves and roots and translocated to other plant tissues (USEPA, 2010a). The selectivity of the herbicide is due to differential rates of metabolism in different plant species (USEPA, 2010a).

The registrant has proposed the following as the mode of action for orthosulfamuron for vertebrates, as cited in the Health Effect s Division’s 2007 risk as sessment (USEPA, 2007, D319264):

“In rats, orthosulfamuron exposur e results in increas ed incidences of thyroid follicular cell adenomas. The registrant has proposed a mitogenic mode of action for the tumorigenic effects of orthosulfamuron, whic h involves induction of uridinediphosphateglucuronosyltransferase (UDP-GT) , leading to increased elim ination of thyroid hormone (T4) and subsequent pituitary release of thyroid stimulating hormone (TSH). The prolonged release of TSH results in thyroi d hypertrophy, hyperplasia, and eventually, tumor formation. The [Cancer Assessment Risk Committee] CARC determined that it is

### 7 possible that exposure to orthos ulfamuron could caus e thyroid tumors vi a perturbation of thyroid-pituitary functioning, due to enhanced hepatic clearance of thyroxin. However, the thyroid hormone data, whic h are critical to delineatin g a sequence of key events leading to tumor formation, are inadequate. Thus, the available data do not fully support the proposed MOA.”



# V. Overview of Pesticide Usage

Orthosulfamuron was first registered in 2004 unde r a Section 5 Experimental Use Permit (EUP) with the first Section 3 registrations becoming active in 2007. The only currently registered use is as an herbicide on rice. It may be used to control barnyardgrass, Echinochloa crus-galli

, propanil-resistant barnyardgrass, other annual grasse s, and certain sedge and broadleaf weeds. It may be applied to dry soil of dry-seeded rice befo re, during, or after plan ting. It may also be applied to foliage, for dry- or wet-seeded rice. For wet-seeded rice applications, some labels indicate that rice be flushed af ter a foliar application to maximi ze root adsorption. Formulations include water dispersable granules and dry granules and both fo rmulations may be applied via aerial and ground broadcast. All labels prohibit applications via chemigation or irrigation systems. There are currently eight registered labels, i.e ., four state special local need Section 24C labels and four Section 3 labels. Table 1 provides details on the curre ntly registered uses of orthosulfamuron. 1 

### The maximum single application rate is 0.067 lbs a.i./A and one application per season or year is allowed.

1 EPA Registration Number 80289-4 is the only technical product with 99.0% orthosulfamuron . This product is not included in Table 1

.8Table 1. Summary of currently registered products of orthosulfamuron.Reg#/ProductNamePercenta.i.Form.Max SeasonalApplicationRate(lbs a.i./A)ApplicationMethod TypeGround/AircraftApplicationMethod TimingGeographicLimitationsSelectedLimitations80289-13/STRADAXT50.0aWG0.066Broadcast toSoil or Foliage /wet and dryseeded riceGround/AircraftDelayedpreemergence/Postemergence/Preplant/PreemergenceCan be usedin AR, LA,MS, MO, TN,and TXDo not use on sandor loamy sand soil.Max windspeed is10 mph for groundapp and 8 mph foraerial app.80289-6/STRADA®GR0.50G0.067Broadcast/ Wetseeded riceAircraft/GroundFoliage of weedsMay only beused in CAMax windspeed foraerial application is10 mph.80289-5/STRADA®CA50.0WDG0.067Broadcast tofoliage/ wet anddry seeded riceAircraft /GroundFor dry seeded rice,early postemergenceto pre-flood. Forwet-seeded rice,early postemergenceto middle-latepostemergenceMay only beused in CADrain rice fields forapp. Use of anapproved adjuvantor surfactant isrecommended.AR080012/STRADAWG50.0WDG0.067BroadcastAircraftFoliarMay only beused in ARSpray boom heightmay not exceed 15feet / medium orlarger DSD categoryLA080007/STRADAWG50.0WDG0.067BroadcastAircraftFoliarMay only beused in LANoneMO080002/ STRADAWG50.0WDG0.067BroadcastAircraftFoliarMay only beused in MONoneTX080007/STRADAWG50.0WDG0.067BroadcastAircraftFoliarMay only beused in TXNoneAbbreviations: Form=formulation; Max=maximum; WDG=water dispersable granule; WG=wettable granule; App=application; DSD=drop size distributiona Packaged with another herbicide product, QuinStar® Herbicide, containing 75% quinclorac. The co-pack is made to be used as atank mix of the two products.

### 9 According to the February 3, 2011 “Screening Level Estimates of Agricultural Uses of Orthosulfamuron” provided by the Biological and Economic Analysis Division (BEAD), the amount of orthosulfamuron used on rice is 2,000 lbs per year 2 

### , a very low application rate relative to those for many other herbicides. The percent crop treated was less than 2.5 percent in a given year 3 

### . Rice is primarily grown in California, Texas, Louisiana, Arkansas, Mississippi, and Missouri and orthosulfamuron was primarily used in Arkansas, Missouri, and California (USEPA, 2010a). To identify those states w ith less rice production “Quick Stats” from the National Agricultural Statistics Service 4 

### was searched for states wh ere rice was harvested in 2007. In addition to the primary rice growing st ates, rice was also harvested in Florida, Tennessee, Texas, and Oklahoma. Figure 1 shows the acres plante d in rice by county for selected states in 2009. These are the areas wh ere the highest amounts of rice are grown in the United States and thus the areas where or thosulfamuron would mo st likely be used.

Figure 1. Acres Planted in Rice by County fo r Selected States in the United States. Prepared by the National Agricultural Statistics Service (NASS) and downloaded from http://www.nass.usda.gov/Charts_a nd_Maps/Crops_County/ar-pl.asp



### Limitations stated on orthosulfamu ron labels that are relevant to the ecological risk assessment are listed in Appendix I

.

2 Estimated as an average across 2001-2010 and then rounded.

3 This is the maximum value reported acr oss all data sources and all years.

4 http://quickstats.nass.usda.gov/results/90ECABCD-EAC2-3285-A03A-121D372EE6A6

### 10 

# VI. Environmental Fate and Transport

Summary

Orthosulfamuron will enter the e nvironment via spray directly onto soil, foliage, or water of rice paddies. It may move off-site via spray drift, leaching, runoff, and release of paddy water. Orthosulfamuron has five estimated pKa values . Its solubility increases with pH. Orthosulfamuron is considered semivolatile fr om dry non-adsorbing surfaces and non-volatile from water and moist soil. It is not likely to bioc oncentrate in aquatic or te rrestrial organisms. Chemicals with half-lives greater than 60 days in soil, water, and se diment are considered persistent (USEPA, 2008b). The range of half-lives for ort hosulfamuron fall into both the persistent and nonpersistent categories. The prim ary routes of degradation are via hydrolysis, aerobic aquatic, and anaerobic aquatic metabolism. Soil metabolism studies are not available. Seven major degradates have been observed in environmental fate studies, one of which is structurally similar to the parent ( i.e ., retains the sulfonylurea moie ty) and the others are formed by splitting the parent molecule, effectively removing the sulfonylur ea moiety. Identification of which degradates are residues of concern and the pathways of fo rmation of the degradates is discussed in Section XI. Identification of Stressors of Concern . Many of the submitted studies are considered supplemental and da ta are still needed to fully unde rstand the environmental fate of orthosulfamuron and its degradates.

Fate Description

Table 2 summarizes the identity information and physical-chemical properties of orthosulfamuron. Table 3 summarizes other environmental fate data. A more complete discussion of the environmental fate studies is available in Appendix A . Orthosulfamuron will enter the environment via spray dir ectly onto soil, foliage, or wate r. It may move off-site via spray drift, leaching, and runoff, especially duri ng rainfall events. Orth osulfamuron is predicted to have five dissociation constants (pKa of -1.4, 0.7, 3.5, 9.6, and 11.5) (MRID 46219011). The vapor pressure indicates that some may move o ffsite via volatilization from dry non-adsorbing surface, which could occur with application onto dry soil, as it is classified as a semivolatile compound using OPPTS 5 

### Guideline 835.6100 classification; however, this is expected to be a minor transport pathway. It is classified as non-volatile from water and moist soil. Orthosulfamuron’s water solubility increases with pH and has a very wide range over environmentally relevant pHs (26 mg/L at pH 4.0 and 38,900 at pH 8.5, both measured at 20 o 

### C, MRID 446219009). Log octanol-wate r partition coefficients (K ow 

### ) range from 2.02 at pH 4 to <0.3 at pH 10 at 20 o 

### C (MRID 46219012 )



### .

5 Office of Prevention, Pesticides, and Toxic Substances (OPPTS) is now the Office of Chemical Safety and Pollution Prevention (OCSPP); how ever, the guidelines still reference OPPT S and so the guidelines are referenced with OPPTS in this document.

### 11 Table 2. Summary of physical-chemica l properties of orthosulfamuron 1

Parameter Value and Units Source and/or Comment
PC Code 108209 (USEPA, 2006, D333514)
CAS Number CAS 213464-77-8 (USNLM, 2009)

SMILES Code c1cccc(c1NS(=O)(=O)NC(Nc1nc(cc(n1)OC) OC)=O)C(=O)N(C)C (NCI/CADD Group, 2011)

Chemical Name 1-(4,6-dimethoxypyrimidin-2-yl)-3-[2- (dimethylcarbamoyl)phenylsulfamoyl]urea (IUPAC) (USEPA, 2006, D333514)

Empirical Formula C 16 H 20 N 6 O 6 S (USEPA, 2006, D333514)

Molecular Weight 424.4 g/mole (USEPA, 2006, D333514)

UV/Visible Absorption Significant absorbance observed below 300

nm MRID 46559001; Acceptable

Water Solubility pH 4.0 at 20 o C: 26 mg/L pH 7.0 at 20 o C: 629 mg/L pH 8.5 at 20 o C: 38,900 mg/L MRID: 44621909; Acceptable

Vapor Pressure <1.1 × 10 -6 Torr at 25 o C 8.37× 10 -7 Torr at 20 o C
<1.4 × 10 -4 Pa at 25 ° C
1.12 × 10 -4 Pa at 20 ° C MRID: 46219010; Acceptable, Semivolatile from dry nonadsorbing surfaces

Henry’s Law

constant pH 4, 1.8 x 10 -8 atm-m 3 /mol pH 7, 7.4 x 10 -10 atm-m 3 /mol pH 8.5, 1.2 x 10 -11 atm-m 3 /mol Estimated from vapor pressure and water solubility at 20 o C.

Dissociation Constant (pK
a ) -1.4, 0.7, 3.5, 9.6, and 11.5 MRID: 46219011; Acceptable, estimated using ACD/I-LAB Web Service

Log K ow pH 4: 2.02 pH ~7: 1.31 pH 10: <0.3 MRID: 46219012; Acceptable. Temperature not reported. Not likely to bioconcentrate.

Air-water partition coefficient (K A W ) pH 4: 7.35 x 10 -7 (log K AW = -6.13) pH 7: 3.04 x 10 -8 (log K AW = -7.52) Estimated from vapor pressure and water solubility at pH 7 and 20 o C. Nonvolatile from water.

Octanol-air partition coefficient (K OA ) pH 4: 1.4 x 10 8 (log K OA = 8.2) pH 7: 6.7 x 10 8 (log K OA = 8.8) Estimated from K AW and K OW . Potential to accumulate in terrestrial organisms only at pH 4 and only if transformation is low. 2 Therefore, it is unlik ely to accumulate in terrestrial organisms.

C water+soil /C air pH 4: 2.96 x 10 6 to 2.74 x 10 7 pH 4: 7.17 x 10 7 to 6.64 x 10 8 Estimated from K AW , r of 6, and range of measured K d values. Non-volatile from moist soil

1 All estimated values were estimated according to “ Guidance for Reporting on the Environmental Fate and Transport of the Stressors of Concern in Problem Formulations for Registration Review, Registration Review Risk Assessments, Listed Species Litigation Assessments, New Chemical Risk Assessments, and Other Relevant Risk Assessments ” (USEPA, 2010b).
2 A recent scientific advisory panel (SAP) reported, “Gobas et al (2003) concluded that chemicals with a log K OA > 5 can biomagnify in terrestrial food chains if log K OW >2 and the rate of chemical transformation is low. However,

### 12 further proof is needed before acceptin g these limits without reservations ” (USEPA, 2009b). This was also supported by Armitage and Gobas’s work completed in 2007 (Armitage and Gobas, 2007).



### Table 3. Summary of other environmenta l fate and transport properties of orthosulfamuron.

Parameter Value(s) and Units Source (Study Classification) Comments

Hydrolysis 5 Half-life, SFO linear regression 1 : pH 7 at 25 o C: 24.4 days pH 9 at 25 o C: 228 days

pH 4 at 50 o C: 0.02 days pH 7 at 50 o C: 1.5 days pH 9 at 50 o C: 8.0 days MRID 46219015 (supplemental) Values may be used in risk assessment. Values measured at 50 o C are not used in modeling but

show that degradation is more rapid at pH 4 than at pH 7 and 9.

Half-life, SFO linear regression 1 : pH 4 at 50 o C: 0.02 days pH 7 at 50 o C: 1.2 days pH 9 at 50 o C: 8.6 days MRID 46219016 (supplemental) May be used quantitatively but not for use in modeling as the temperature is not environmentally relevant.

Atmospheric Degradation Half-life: 0.049 days (estimated) Estimated Using EPIWeb Version 4.0 see Appendix A

. Not likely to undergo long range transport in vapor phase. 3

Aqueous Photolysis Stable MRID 46588509 (supplemental) Study had many deficiencies but was adequate to show that photolysis was not a significant degradation pathway. Soil Photolysis No data submitted Not applicable None

Aerobic Soil Metabolism No data submitted Not applicable None

Anaerobic Soil Metabolism No data submitted Not applicable None

Aerobic Aquatic Metabolism 4 Half-life, SFO linear regression 1 , at 20 o C:

Parent Only 40.6 and 36.3 (AR, loam soil pH 6.9- 7.25, water pH 7.8-6.81) 24.1 and 21.3 days (CA, clay soil pH 6.0-6.97, water pH 7.7-7.03)

Parent+ Unextracted residues: 70.5 and 59.2 (AR, loam soil pH 6.9- 7.25, water pH 7.8-6.81) 65.4 and 30.3 days (CA, clay soil pH 6.0-6.97, water pH 7.7-7.03) MRID 46219017 (supplemental) Total system half-lives are shown for different rings labeled. Unextracted residues ranged from not detected to 33% applied radioactivity. Reasonable attempt

to extract all residues was not made. Rate may be adjusted to standard temperature of 25 o C for modeling.

### 13 Parameter Value(s) and Units Source (Study Classification) Comments

Anaerobic Aquatic Metabolism Half-life, SFO linear regression 1 , at 20 o C:

Parent Only: 80 and 89 days (AR water-loam soil pH 6.9-7.45, water pH 7.8-7.44) 41 and 41 days (CA pond-water clay soil pH 6.0-6.72, water pH 7.7-6.82)

Parent+Unextracted Residues: 142 and 217 days (AR water-loam soil pH 6.9-7.45, water pH 7.8-7.44) 88 and 161 days (CA pond-water clay soil pH 6.0-6.72, water pH 7.7-6.82) MRID 46578967 (supplemental)

Several deficiencies. Not appropriate for use in modeling. Rate may be adjusted to standard temperature of 25 o C for modeling. 6

Sorption coefficients Solid-water distribution Coefficient,
K d in L/kg

6.1, sandy loam, pH 6.3, 1.13%OC 8.6, silt loam, pH 5.7, 2.03%OC 6.3, silt loam, pH 6.8, 1.00%OC 6.1, clay loam, pH 6.1, 2.60% OC

Organic-carbon normalized distribution coefficient, K OC in L/kgOC: 532, sandy loam, pH 6.29, 1.13%OC 425, silt loam, pH 5.71, 2.03%OC 626, silt loam, pH 6.78, 1.00%OC 266, clay loam, pH 6.11, 2.60% OC MRID 46219074 (supplemental) May be used quantitatively.

Solid-water distribution Coefficient,
K d in L/kg 2.5, sandy loam, pH 6.5, 1.04% OC 7.5, sandy loam, pH 5.6, 0.35% OC 3.2, sand, pH 4.70, 1.03% OC 20.7, clay loam, pH 5.4, 3.01% OC 2.0, silt loam, pH 7.5, 0.92% OC 7.0, loam, pH 7.4, 1.8% OC

Organic-carbon normalized distribution coefficient, K OC in L/kgOC: 238, sandy loam, pH 6.5, 1.04%OC 2145, sandy loam, pH 5.6, 0.35% OC 307, sand, pH 4.7, 1.03% OC 687, clay loam, pH 5.4, 3.01% OC 215, silt loam, pH 7.5, 0.92% OC 389, loam, pH 7.4, 1.8% OC MRID 46578971 (supplemental) May be used quantitatively. The coefficient of variation(CV) for all

K d values was 76%, 98% for all
K OC values, when the outlying high K d and K OC are removed for the soil with an OC content of 0.35%, the CV was 81% for Kd values and 42% for K OC values.

### 14 Parameter Value(s) and Units Source (Study Classification) Comments

Aged Column Leaching Orthosulfamuron not observed in leachate but was observed in Segment D (21 cm depth). DBS-acid, DBS amide, DB amine, o-desmethyl orthosulfamuron, DOP urea, DOP amine, and o-desmethyl DOP urea were all detected at lower segments as well. MRID 46219018 (acceptable) None

Soil Column Leaching Orthosulfamuron was the only compound found in leachate and lower soil segments. DOP urea was found in top 0-25 cm of soil and DOP amine was not detected in one soil but was detected in another. Movement through the column indicates that it has the potential to move through soil in environment. MRID 46578968 (supplemental) May be used quantitatively. Arkansas sandy loam soil and North Dakota sand soil.

Aquatic Field Dissipation Dissipation SFO Half-life 2 , linear regression 1

Arkansas Site (pH 6.7): 4.1 days (soil) 6.2 days (sediment) 6.4 days (water)

California Site (pH 7.7): 2.3 days (soil) 4.3 days (sediment) Not calculated (water) MRID 46578985 (supplemental) Associated ECM and ILV are not available for soil/sediment and water. Field spikes were prepared for water, soil, and sediment at one

sampling interval. These valuesmay underestimate the field halflives and should be considered with an understanding of the data

limitations. See AppendixA

.

Steady State Bioconcentration
Factor Measured at 135.2 μg/L at 22-23 o C in Bluegill Sunfish ( Lepomis macrochirus ): 0.29 L/kg wet weight, edible tissue 0.34 L/kg wet weight, nonedible tissue 32 L/kg wet weight, whole fish 16 – 29 L/kg-lipid

Measured at 1391-1550 μg/L at 22- 23 o C: 0.72 L/kg wet weight, edible tissue 1.14 L/kg wet weight, nonedible tissue 0.97 L/kg wet weight, whole fish 52-68 L-kg-lipid 46588507 (acceptable) None

Environmental Chemistry Method: Water None submitted NA None

### 15 Parameter Value(s) and Units Source (Study Classification) Comments

Environmental Chemistry Method: Soil and Sediment None submitted NA None

Abbreviations: ECM=Environmental Chemistry Method; ILV=Independent Laboratory Validation; SFO=Single First Order

1 Degradation kinetics were calculated using the single first order (SFO) decay equation using either nonlinear regression of non-transformed data or linear regression of natural log-transformed data.

2 The half-life value may reflect both dissipation and degradation processes.

3 The minutes of the Scientific Adviso ry Panel examining issues related to persistent, bioaccumulative, and toxics states, “To protect against long range tr ansport, a two-day degradation half-life in air is used internationally in regulations that identify persistent chemicals.” (USEPA, 2009b)

4 MRID 46588508 is an unacceptable aerobic aquatic metabolism study.

5 MRID 46578970 examined hydrolysis at pH 5 and 25 o C. The study is unacceptable. 6 The anaerobic aquatic metabolism study was conducted using a soil and unextracted residues made up as much as 43% of applied radioactivity. The degradate profile could change if the identity of the unextracted residues were known. Additional data prov ided on anaerobic aquatic metabolism woul d allow EFED to more accurately predict the rate of anaerobic aquatic metabolism wh en estimating surface water concentrations.



### Orthosulfamuron may be persistent in some aqua tic systems and non-persis tent in other aquatic systems. 6 

### Hydrolysis rates at pH 7 and aerobic aquatic metabolism rate s for parent alone indicate that orthosulfamuron is not persistent in aerobic a quatic environments. However, hydrolysis rates at pH 9, anaerobic aquatic half-liv es and aerobic aquatic half-lives considering both the parent and unextracted residues indicate th at orthosulfamuron may be persistent in some aquatic environments.

Hydrolysis rates decrease as pH increases (half-li fe =24 days at pH 7 and 228 days at pH 9 at 25 o 

### C). A hydrolysis rate at an aci dic pH is not available at 25 o 

### C. Limited data are available to understand the behavior of orthosulfamuron in th e presence of light as the available aqueous photolysis study did not compare the light intensity to natural sunlight; however, the available data are adequate to show that aqueous photolysis is not a si gnificant degradation pathway as only 6% was lost when exposed to wavelengths where absorbance was observed for seven days (MRID 46588509). Soil photodegradati on data are not available.

Data are not available examining aerobic and anaerobic soil metabolism rates. Orthosulfamuron did undergo biodegradation in bot h aerobic and anaerobic aqua tic environments. Aerobic aquatic metabolism half-lives ranged from 21 to 41 days at 20 o 

### C in two sediments (MRID 46219017) and anaerobic aquatic half-lives ranged from 41 to 89 days at 20 o 

### C in two soils (MRID 46578967). It is not known wh ether a portion of the unextr acted residues, which made up a maximum of 43% of applie d radioactivity, were the parent compound or degradates of concern; therefore half-lives were also calcula ted assuming that unextracted residues were the parent. Aerobic aquatic metabolism half-lives calculated assuming that unextracted residues were the parent ranged from 30 to 71 days at 20 o 

### C in two sediments (MRID 46219017) and anaerobic aquatic half -lives ranged from 88 to 217 days at 20 o 

### C in two sediments (MRID 46578967). Hydrolysis, which varies with pH, may ha ve contributed to some of the degradation

6 International half-lives that are considered persistent in soil, water, and sediment range from greater than 60 days to greater than 365 days (USEPA, 2008b).

### 16 observed in these studies and this will be cons idered when using these rates in modeling. Orthosulfamuron’s aerobic and anae robic aquatic half-lives indicate that a small percentage of applied orthosulfamuron (~0-31%) may remain in soil/sediment 365 days after application; therefore, some accumulation may occur with successive annual applications. Supplemental aquatic field dissipation half-liv es ranged from two to six days when orthosulfamuron was applied to bare ground plots in California (pH 7.7) and Arkans as (pH 6.7) followed by flooding (MRID 46578985). Time to ninety percent dissipati on ranged from 8 to 21 days. The results are questionable as the results from field spikes indi cated that some compounds were not stable in field spiked soil samples (percent recovery ra nged from 16-100%) and validated environmental chemistry methods are not available. 7 

### Maximum concentrations of orthosulfamuron and transformation products observed in the study are reported in Appendix J

.
Orthosulfamuron is classified as moderately m obile to slightly mobile with organic carbon normalized soil-water distribution coefficients (K oc 

### ) values ranging from 215 – 2,145 L/kg-OC measured in ten soils (MRID 46578971; USEPA, 2010b). Based on orthosulfamuron’s water solubilities and estimated pKa values, its affinity to organic materials (and thus K OC 

### values) are expected to increase with pH; however, K OC 

### values were not correlated to pH and available sorption coefficients did not show a trend with pH. This is likely due to the limited data set that does not provide enough information to fully understand the influence of various soil/sediment constituents on sorption. It has the potential to reach ground water, especially in vulnerable alkaline soils with low organi c-carbon content and/or the pres ence of shallow ground water. Based on the high water solubility (629 mg/L at pH 7 and 20 o 

### C) and the low K oc 

### values, a higher percentage of orthosulfamuron will be found in wate r as compared to sediment. As its solubility, sorption coefficients, and hydrolysis are influe nced by its association state and pH, a higher percentage will be found in wate r under higher pH conditions.

Based on the log K ow 

### (<0.3 – 2.02) and measured bioconcentr ation factors in bluegill Sunflish ( Lepomis macrochirus, BCFs, lipid normalized values ra nge from 16 to 68 L/kg-lipid), orthosulfamuron is not likely to bioconcentrate in aquatic organisms. Orthosulfamuron’s vapor pressure is just high enough to be between the classificati ons of non-vola tile under field conditions to intermediate to high volatility under field conditions, using the OPPTS Guideline 835.6100 classification system. Thus, it is cons idered a semivolatile compound from dry nonadsorbing surfaces. Based on the Henry’s law- constant, air-water pa rtition coefficient (K AW 

### ), and solid-water distribution coefficients (K d 

### ), it is classified as non-volatile from water and moist soil (USEPA, 2010b). The estimated K OA 

### value (1.4 x 10 8 

### at pH 4 and 6.7 × 10 -8 

### at pH 7), combined with the log K ow 

### at pH 4 indicate that orthosul famuron may have the potential to accumulate in terrestrial organisms at low pH conditions 8,9 

### ; however, this potential is only

7 This study would be more reliable with a complete ILV of the ECMs and if results from field spikes collected at each sampling interval were provided. Field spiked samples were only collected at one sampling event and the percent recoveries were variable and often low. It is not known if the results of the field spikes for the one sampling event are applicable to other sampling events and whether it is appropriate to correct all samples using the field spikes from one sampling interval. Finally, the LOQ for th e ECM in water was higher than that necessary to detect levels that could result in a risk concern (0.02 μg/L) and not all major degradates were looked for in the samples. Therefore, the study is not upgradeable to acceptable but ma y be adequate to assess risk if the ECM and field spike recoveries issues are resolved.

8 The pH of precipitation may be as low as 4.2 (see USGS National Water Conditions; http://water.usgs.gov/nwc/NWC/pH/html/ph. html) and the pH of surface water ranges from 5-10 (USGS Continuous

### 17 observed at low pH where a rapid hydrolysis is expected. Theref ore, accumulation in terrestrial organisms is not likely to be a risk concern.

The transformation products resu lting from the environmenta l degradation processes of orthosulfamuron are:

• 2-dimethylcarbamoylphenyl sulfamic acid (DBS acid; IR7863; S1);

• 2-sulfamoylamino-N,N-dimethylbenzamide (DBS amide; S2);

• 2-amino-N,N-dimethylbenzam ide (DB amine; S4);

• 1-(4-hydroxy-6-methoxypyrimidin-2 -yl)-3-[2-(dimethylcarbamoyl) phenylsulfamoyl]urea (o-desmethyl or thosulfamuron; IR8181; S9);

• N-(4,6-dimethoxypyrimidin-2-yl)urea (DOP urea; IR7825; S12);

• 4,6-dimethoxypyrimidin-2-yl amine (DOP amine; S13); and

• N-(4-hydroxy-6-methoxypyrimidin-2-yl)urea (o-desmethyl DOP urea; S15).

Two other degradation products S5 and S11 are composed of multiple unresolved compounds. 

### Figure 2 shows the degradation pathway of orthosulfamuron.

Water Quality Watch; available at http://waterwatch.usgs.gov/wqwatch/ ). In rice growing areas, surface water pH ranged from 5-9 and precipitation pH was ≥ 4.7.

9 A recent scientific advisory panel (SAP) reported, “Gobas et al (2003) concluded that chemicals with a log K OA > 5 can biomagnify in terrestrial food chains if log K OW >2 and the rate of chemical transformation is low. However, further proof is needed before acceptin g these limits without reservations ” (USEPA, 2009b). This was also supported by Armitage and Gobas’s work completed in 2007 (Armitage and Gobas, 2007).

### Figure 2 40). Ab b

DBS aci were th e observe d the final observe d of resid u it is lik e dissipati o orthosul f b oth site s sedimen t major d e structure maximu m

10 Major d e 

### 2 . De g rada t b reviations

d, DB ami n

e major deg r d

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### t ion Pathw a

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### T d entified tra n

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### 18 s ulfamuron

o ve fi g ure.

u rea, DBS a m

o ws the ma x product. M

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u nidentified

.

percentag e

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### (adapted f r

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. If all resi d

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e low detecti o

c id were ma j At the Cali f d ates were d

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### r om MRID

o -desmethyl

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m aximums w percentage s c metabolis m d

ues were fu l

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w ere obser v

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### 19 Table 4. Summary of maximum amount of tr ansformation products observed in fate studies.

Transformation Product Study Type MRID Maximum %AR (day) Final %AR (study length)

DBS Acid Hydrolysis 46219015 58 ( 37 days, pH 7, 25 o C) 23 (176 days, pH 9, 25 o C) 86 (5 days, pH 4, 50 o C) 66 (5 days, pH 7, 50 o C) 12 (5 days, pH 9, 50 o C) 58 ( 37 days, pH 7, 25 o C) 23 (176 days, pH 9, 25 o C) 86 (5 days, pH 4, 50 o C) 66 (5 days, pH 7, 50 o C) 12 (5 days, pH 9, 50 o C) Aerobic Aquatic 46219017 61 (61 days, CA phe) 61 (61 days, CA phe ) Anaerobic aquatic 46578967 39 (150 days, CA pyr) 39 (150 days, CA pyr)

DB Amine Hydrolysis 46219015 2 (37 days, pH 7, 25 o C) 13 (176 days, pH 9, 25 o C) 13 (5 days, pH 4, 50 o C) 11 (5 days, pH 7, 50 o C) 6 (5 days, pH 9, 50 o C) 2 (37 days, pH 7) 13 (176 days, pH 9) 13 (5 days, pH 4, 50 o C) 11 (5 days, pH 7, 50 o C) 6 (5 days, pH 9, 50 o C)
Aerobic aquatic 46219017 1 (90 days, CA sediment) 1 (90 days, CA sediment)
Anaerobic aquatic 46578967 6 (42 days, AR phe) 5 (42 days, AR phe)

DOP amine Hydrolysis 46219016 4 (1hr, pH 4, 50 o C) 11 (52 hrs, pH 7, 50 o C) 53 (13 days, pH 9, 50 o C) 4 (1hr, pH 4, 50 o C) 11 (52 hrs, pH 7, 50 o C) 53 (13 days, pH 9, 50 o C) Aerobic aquatic 46219017 1 (90 days, AR sediment) 1 (90 days, AR sediment) Anaerobic Aquatic 46578967 <1 (100 days, AR pyr) <1 (180 days, AR pyr)

DOP urea Hydrolysis 46219016 78 (1hr, pH 4, 50 o C) 60 (52 hrs, pH 7, 50 o C) 13 (13 days, pH 9, 50 o C) 78 (1hr, pH 4, 50 o C) 60 (52 hrs, pH 7, 50 o C) 13 (13 days, pH 9, 50 o C)
Aerobic Aquatic 46219017 47 (90 days, AR pyr) 47 (90 days, AR pyr)

Anaerobic Aquatic 46578967 19 (59 days, CA pyr) 16 (150 days, CA pyr)

DBS amide Hydrolysis 46219015 7 ( 37 days, pH 7, 25 o C) 8 (176 days, pH 9, 25 o C) 9 (0.13 days, pH 4, 50 o C) 8 (2 days, pH 7, 50 o C) 10 (5 days, pH9, 50 o C) 7 ( 37 days, pH 7, 25 o C) 8 (176 days, pH 9, 25 o C) 1 (0.04 days, pH 9, 50 o C) 5 (5 days, pH 7, 50 o C) 10 (5 days, pH9, 50 o C)
Anaerobic aquatic 46578967 4 (180 days, AR phe) 4 (180 days, AR phe)

Aerobic aquatic 46219017 4 (90 days, AR phe) 4 (90 days, AR phe)

O-desmethyl orthosulfamuron Aerobic aquatic 46219017 9 (90 days, AR pyr) 9 (90 days, AR pyr)

Anaerobic Aquatic 46578967 19 (100 days, AR phe) 16 (180 days, AR phe) 17 (180 days, AR pyr) 17 (180 days, AR pyr) O-desmthyl DOP

urea Aerobic aquatic 46219017 4 (44 days, CA) 3 (90 days, CA) Anaerobic aquatic 46578967 3 (180 days, AR pyr) 3 (180 days, AR pyr)



## A. Monitoring Data

The following databases and sources were searched for monitoring information on orthosulfamuron on July 5, 2011:

### 20 • 

### 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 /)

• 

### Sampling for Pesticides Residues in Calif ornia Well Water Cumulative Report; EEH03- 08; December 2003 ( http://www.cdpr.ca.gov/docs/emon/pubs/ehapreps/eh0308.pdf )

• 

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

No monitoring data are available as none of the databases reported looking for orthosulfamuron.



## B. Clean Water Act

Orthosulfamuron is not identifie d as a cause of impairment for any water bodies listed as impaired under section 303(d) of the Clean Water Act, based on information provided at http://iaspub.epa.gov/tmdl_waters10/attains_ nation_cy.cause_detail_303d?p_cause_group_id=88
5 . In addition, no Total Maximum Daily Loads (TMD L) have been developed for the herbicide, based on information provided at http://iaspub.epa.gov/tmdl_waters10/attains_ nation.tmdl_pollutant_de tail?p_pollutant_group_id =885&p_pollutant_group_name=PESTICIDES . More information on impaired water bodies and TMDLs can be found at http://www.epa.gov/owow/tmdl/

.
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: Inclusion of Impaired Water Body and Other Water Quality Data in OPP’s Registration Review Risk A ssessment and Management Process (see: http://www.epa.gov/oppfead1/cb/p pdc/2006/november06/session1-sop.pdf ), in order to ensure they can be used quantitatively or qual itatively in pesticide risk assessments.



# VII. Receptors

Consistent with the process described in th e Overview Document (USEPA, 2004), the risk assessment will rely on a surrogate species approach. Toxicological data generated from surrogate test species, which are intended to be representativ e of broad taxonomic groups, are used to extrapolate to potential effects on a variety of species (receptors) included under these taxonomic groupings. The most sensitive endpoi nt for each taxon is evaluated. Assessment endpoints include direct toxic eff ects on the survival, reproduction, and growth of terrestrial and aquatic life, as well as indirect effects, such as reduction in pr ey base and/or modification of habitat. The evaluated taxa includ e freshwater fish, freshwater aqua tic invertebrates, birds, small mammals, terrestrial invertebrates, algae, and terrestrial plants.

Acute and chronic toxicity data from studies submitted by pesticide registrants along with the available open literature are used to evaluate th e potential direct and in direct effects on aquatic

### 21 and terrestrial receptors. These data include studies on the technical grade active ingredient, degradates, and formulated products ( e.g . “six-pack” acute toxicity studies). The open literature studies are identified using EPA’ s ECOTOX database, which employs a literature search engine for locating chemical toxicity data for aquatic life, terrestrial plants, and wildlife (USEPA, 2009a). The evaluation of both sources of data can also provide insight into the direct and indirect effects of orthosulfamuron on biotic co mmunities from loss of species that are sensitive to the chemical and from changes in structure and functional characteri stics of the affected communities.

A search using EPA’s ECOTOX database will be pe rformed as a routine cour se of action for risk assessment for orthosulfamuron.

Acute (short-term) and chroni c (long-term) toxicity informa tion is characterized based on registrant-submitted studies and a comprehe nsive review of the open literature on orthosulfamuron. Other sources of information, including use of the acu te probit dose-response relationship to establish the probability of an individual effect and reviews of the Ecological Incident Information System (EIIS), are conduc ted to further refine the characterization of potential ecological effects asso ciated with exposure to ort hosulfamuron. A summary of the available ecotoxicity information and the incide nt information for orthosulfamuron are provided below.

Table 5 provides a summary of the most sensitive su rrogate species tested to characterize the potential acute and chronic ecological effects of orthosulfamuron. Interestingly, rice is the most sensitive monocot plant (seedling emergence test).

Table 5. Most Sensitive Species Evaluate d for Potential Ecological Effects from Orthosulfamuron.

Exposure Scenario Species Acute Toxicity

-- Chronic Toxicity Citation
MRID Acute Toxicity Classification

Birds 1

Acute (Dose-based) Mallard duck ( Anas platyrhynchos )

and
Bobwhite Quail ( Colinus virginianus ) LD 50 >1960 mg a.i./kg-bw Single oral dose 46260107 (Acceptable) Slightly Toxic

Chronic Mallard duck

and Bobwhite Quail 3 NOAEC = 1280 mg a.i./kgdiet Avian reproduction 46578949 (Duck-Acceptable) 46578950 (Quail-Acceptable) --

Mammals

Acute
Laboratory rat ( Rattus norvegicus ) LD 50 >5000 mg a.i./kg-bw Single oral dose 46219019 (Acceptable) Practically Non-toxic

Chronic NOAEL (changes in body wt, hepatotox, nephrotox) = 5 mg/kg/day or 100 mg/kg-diet Chronic Toxicity Study MRID 46578913

(Acceptable) --

### 22 Exposure Scenario Species Acute Toxicity

-- Chronic Toxicity Citation
MRID Acute Toxicity Classification

Insects

Acute (contact) Honey bee ( Apis mellifera L. ) LD 50 >100 ug a.i./bee 48-Hour 46219046 (Acceptable) Practically Non-toxic Acute (oral) LD 50 >109.4 ug a.i./bee 48-Hour 46219046 (Supplemental)
Freshwater fish 2

Acute Rainbow Trout ( Oncorhynchus mykiss ) LC 50 >122 mg a.i./L 96-Hour 46219042 (Acceptable) Practically Non-toxic

Chronic Fathead Minnow ( Pimephales promelas ) NOAEC (dry wt) = 6.1 mg a.i./L Early Life Stage 46578953 (Acceptable) --

Freshwater Invertebrates

Acute Water Flea ( Daphnia magna ) EC 50 (mortality/immobility) > 97.3 mg a.i./L 48-Hour 46219044 (Acceptable) Practically Non-toxic

Chronic Water Flea ( Daphnia magna ) NOAEC (total length) = 6.5 mg a.i./L 21-Day 46578956 (Acceptable) --

Estuarine/Marine Fish

Acute Sheepshead Minnow ( Cyprindon varigatus ) LC 50 >123 mg a.i./L 96-Hour 46578951 (acceptable) Practically Non-toxic

Chronic *No studies available*
Estuarine/Marine Invertebrates

Acute Eastern Oyster ( Crassostrea

virginica ) EC 50 >97 mg a.i./L 96-Hour 46578957 (Acceptable) Slightly Toxic

Chronic Mysid Shrimp ( Americamysis bahia ) NOAEC = 27 mg a.i./L 29 Days 46578954 (Supplemental) --

Terrestrial Plants

Monocot Rice ( Oryza sativa ) EC 25 (dry wt) = 0.078 lb a.i./A

---- NOAEC = 0.0436 lb a.i./A Seedling Emergence 46578941 (Acceptable) NA

Onion ( Allium cepa 

### ) EC 25 (dry wt)=0.0048 lb a.i./A

---- NOAEC = 0.00169 lbs a.i./A Vegetative Vigor 46578942 (Supplemental) NA

Dicot Radish ( Raphanus sativus ) EC 25 =0.040 lb a.i./A

---- NOAEC = 0.015 lb a.i./A Seedling Emergence 46578941 (Acceptable) NA

Carrot ( Daucus carota ) EC 25 = 0.00012 lb a.i./A EC 05 = 0.000027 lb a.i./A

---- NOAEC < 0.0000664 Vegetative Vigor 46578942 (Supplemental) NA

Aquatic Plants

Aquatic vascular Plants Duckweed ( Lemna gibba ) EC 50 (frond number) =0.0007 mg a.i./L

------- NOAEC = 0.00026 mg a.i./L 7-Day Study 46578939 (Acceptable) NA

EC50 (frond number) = 7-Day Study NA

### 23 Exposure Scenario Species Acute Toxicity

-- Chronic Toxicity Citation
MRID Acute Toxicity Classification
0.00075 mg a.i./L

---- NOAEC = 0.00022 mg a.i./L 46578940 (Acceptable)

Marine Algae 4 Marine Diatom ( Skeletonema

costatum ) EC 50 (biomass) = 0.08 mg a.i./L

------- NOAEC = 0.021 mg a.i./L 46578936 (Supplemental) NA

1 Birds represent surrogates for terrest rial-phase amphibians and reptiles.

2 Freshwater fish may be surroga tes for aquatic-phase amphibians.

3 The NOAEC shown applies to both th e mallard duck and bobwhite quail.

4 The test material was IR5878 50WG containing 49.96% orthosulfamuron.



## A. Effects to Aquatic Organisms

Summary

Available ecotoxicity data indica te that orthosulfamuron is char acterized as practically non-toxic to fish and aquatic invertebrates on an acute expo sure basis. Many of the acute toxicity endpoints are non-definitive ( i.e., “greater than” values) as no mortali ties or effects were observed at the highest concentrations levels tested. Compared to aquatic animals, aquatic plants are orders of magnitude more sensitive to th e herbicide orthosulfamuron.

Freshwater Fish Based on the most sensitive species of freshwater fish tested, i.e ., rainbow trout ( Oncorhynchus mykiss ) with an 96-hr LC 50 

### >122 mg a.i./L, orthosulfamuron is classified as practically nontoxic to fish on an acute exposure basis. No subl ethal effects on fish were reported in the acute toxicity studies.

There are no studies assessing the acu te toxicity of orthosulfamur on formulations or degradates in freshwater fish.

A 33-day, early life-stage toxicity study of ort hosulfamuron in fathead minnow was submitted by the registrant to establish the chronic toxicity of orthosulfamuron to freshwater fish (MRID 46578953). Fish were monitored for embryo surviv al, larval survival, terminal length, dry weight, wet weight, and clinical signs of toxicity. Following chronic exposure (33 days) to fathead minnows ( Pimephales promelas), the reported no observed adverse effect concentration (NOAEC) and lowest observed adverse effect concentrations (LOAEC) were 6.1 and 13 mg a.i./L, respectively, and were based on decrea sed growth (dry weight). The chronic NOAEC value of 6.1 mg a.i./L for effects on growth is th e most sensitive chronic endpoint for freshwater fish.

There are no chronic toxicity studies of ort hosulfamuron formulations or degradates in freshwater fish.

Freshwater Invertebrates

### 24 The waterflea ( Daphnia magna ) was the most sensitive freshwater invertebrate tested with a 48- hr EC 50 

### >97.3 mg a.i./L. Based on this endpoint, orthosul famuron is classified as slightly toxic to freshwater invertebrates on an acute exposure basis. No sublethal effects were noted in the acute toxicity study.

There are no acute toxicity studies of orthosulfa muron formulations or de gradates in freshwater invertebrates.

A 21-day life-cycle toxicity study with orthosulfamuron with the water flea was used to establish the chronic toxicity of orthosulfamuron to fr eshwater. The NOAEC and LOAEC values of 6.5 and 14 mg a.i./L, respectively, are based on reductions in growth (m ean total length). In addition, first-generation survival was reduced at the highe st concentration tested (NOAEC = 52 mg a.i./L; LOAEC = 105 mg a.i./L;). Reproduc tion and dry weight were not a ffected at any concentration tested. The NOAEC of 6.5 mg a.i./L is the most se nsitive chronic endpoint for freshwater aquatic invertebrates exposed to orthosulfamuron.

There are no chronic toxicity studies of ort hosulfamuron formulations or degradates in freshwater aquatic invertebrates.

Estuarine/Marine Fish The acute toxicity of orthosulfamuron to es tuarine/marine fish was evaluated using the sheepshead minnow ( Cyprindon varigatus ). The study reported a 96-hour LC 50 

### >123 mg a.i./L, indicating that orthosulfamuron is practically non-toxic to estuarine/marine fish on an acute exposure basis. No sublethal effects were obs erved in sheepshead minnow exposed up to 123 mg a.i./L. No acute subletha l effects were observed in sheepshead minnow exposed to orthosulfamuron.

No chronic toxicity studies in estuarine/marine fish with orthosulfamuron were submitted, thus, no information is available regarding the s ublethal effects of chronic exposure of estuarine/marine fish to orthos ulfamuron. There are no chronic toxi city tests in estuarine/marine fish with orthosulfamuron, fo rmulations, or degradates.

Estuarine/Marine Invertebrates The most sensitive estuarine/marine invertebrate evaluated is the Eastern oyster ( Crassostrea virginica ) with a 96-hr EC 50 

### >97 mg a.i./L. An acute toxicity study with mysid shrimp resulted in a LC 50 

### >122 mg a.i./L. Based on these results, orthosul famuron is characterized as slightly toxic to estuarine/marine invertebrates on an acute expo sure basis. No sublet hal effects were observed in acute toxicity studies with ort hosulfamuron in the Eastern oyster.

There are no acute toxicity studies of orthos ulfamuron formulations or degradates in estuarine/marine invertebrates.

One life-cycle (29-day) toxicity study with th e mysid shrimp was submitted to establish the chronic toxicity of orthosulfamuron to estuar ine/marine invertebrates. The NOAEC and LOAEC values of 27 and >27 mg a.i./L, respectively, were established fo r orthosulfamuron based on the absence of effects on mortalit y, reproduction, or growth afte r 29 days. The NOAEC of 27 mg

### 25 a.i./L is the most sensitive chronic endpoint for estuarine/marine invertebrates exposed to orthosulfamuron.

There are no chronic toxicity studies of ort hosulfamuron formulations or degradates in estuarine/marine invertebrates.

Benthic Organisms There are no toxicity studies of orthosulfamuro n TGAI, formulations, or degradates in benthic organisms.

Aquatic Plants Studies were submitted for a freshwater vascular plant (duckweed, Lemna gibba ), and for the nonvascular aquatic plants cyanobacteria ( Anabaena flos-aquae ), a freshwater diatom ( Navicula pelliculosa ), a green algae ( Pseudokirchneriella subcapitata; formerly known as Selenastrum capricornutum ), and a marine diatom ( Skeletonema costatum ) exposed to the formulated end-use product (EP), IR5878 50WG (water dispersible granule formula tion containing approximately 50% orthosulfamuron).

Exposure of duckweed to orthosulfamu ron TEP resulted in an 7-day EC 50 

### value of 0.7 μ g a.i./L and a NOAEC of 0.26 μ g a.i./L for use in assessing the po tential risk of or thosulfamuron to aquatic vascular plants.

The most sensitive 96-hr EC 50 

### value for nonvascular plants is 0.08 mg a.i./L; the associated NOAEC of 0.021 mg a.i./L for reductions in biomass in Skeletonema costatum is the most sensitive endpoint on orthosulfamuron toxic ity to aquatic nonvascular plants.



## B. Effects to Terrestrial Organisms

In general, available ecotoxicity data indicate that orthosulfamuron is characterized by low toxicity to mammals, fish, invertebrates and bird s. However, the herbic ide is highly toxic to plants.

The acute and chronic toxicity reference values associated w ith orthosulfamuron exposure to mammals, birds, and terrestrial plants are summarized in Appendix D

.

Mammals An acute oral toxicity study in ra ts indicates that orthosulfamuron is practically non- toxic to rats on an acute oral exposure basis with an LD 50 

### >5000 mg/kg-bw the highest dose tested (MRID 46219019).

A combined chronic/carcinogenic ity study in rats was used by the Health Effects Division to select the dose and endpoint for establishing the chronic reference dose (for use in human exposure assessment). The NOAEL of 5 mg/kg/da y (100 mg/kg-diet) and the LOAEL of 500 mg/kg/day were based on changes in body weight ga in, hepatotoxicity and nephrotoxicity in both sexes (MRID 46578913).

### 26 Birds Studies of acute oral (dose-base d) toxicity in mallard duck ( Anas platyrhynchos ) and bobwhite quail ( Colinus virginianus ) indicate that orthosulfamuron is no more than sl ightly toxic to mallard duck and bobwhite quail on an acute oral exposure basis (LD 50 

### >1960 mg ai/kg-bw, highest dose tested). Orthosulfamuron TGAI is no more than slightly t oxic to mallard duck on a subacute dietary exposure basis (LC 50 

### >4,790 mg ai/kg-diet, hi ghest dose tested).

There are no acute oral or dietary toxicity studies of orthosulfamuron formulations or degradates in avian species.

No treatment-related effects on adult bird mortality, food consumption, body weight, or reproductive parameters and no clini cal signs or treatment-related e ffects in offspring survival or body weight were observed in chr onic studies of reproductive toxi city of orthosulfamuron in mallard duck and bobwhite quail. The NOAEC for both mallard duck and bobwhite quail is 1280 mg a.i./kg-diet (MRID 46578949 and 46578950).

There are no chronic toxicity studies for orth osulfamuron formulations or orthosulfamuron degradates in avian species.

Terrestrial Invertebrates Results of available toxicity st udies indicate that orthosulfamu ron is practically non-toxic to honey bees on an acute contact a nd oral exposure basis. The LD 50 

### for acute contact is >100 μg a.i./bee and the LD 50 

### for acute oral toxicity is >1 09.4 μg a.i./bee (MRID 46219046).

Terrestrial Plants Results of the Tier II seedling emergence study identify rice ( Oryza sativa ) as the most sensitive monocot and radish ( Raphanus sativus) as the most sensitive dico t plants, with decreased dry weight as the most sensitive endpoint affected. The NOAEC and EC 25 

### values of 0.0436 lbs a.i./A and 0.078 lbs a.i./A, respectively, for rice, and 0.015 lbs a.i./A and 0.040 lbs a.i./A, respectively, for radish is used to assess the e ffects of exposure to orthosulfamuron on seedling emergence in non-listed and lis ted terrestrial plants.

Results of the Tier II vegetativ e vigor studies identify onion ( Allium cepa ) as the most sensitive monocot and carrot ( Daucus carota ) as the most sensitive dicot, w ith decreased dry weight as the most sensitive endpoint affected. The NOAEC and EC 25 

### values of 0.00169 lbs a.i./A and 0.0048 lbs a.i./A, respectively, for onion, and the EC 25 

### value of 0.00012 lbs a.i./A, respectively, for carrot are were the most sensitive endpoints for orthosulfamuron on vegetative vigor in nonlisted and listed terrestrial plants. A defin itive NOAEC for the carrot was not identified; therefore, quantitative risks assessme nt for dicots will be based on the EC 05 

### (<0.0000664 lb ai/A).

Investigations/studies have indicated that a small percentage of the label application rate of low dose, high-potency herbicides such as ort hosulfamuron may impact the reproduction of nontarget terrestrial pl ants (Asghari and Evans, 1992a, 1992b; Bhatti et al. , 1995; Boutin et al.

, 2000; Fletcher et al. , 1993; Fletcher et al. , 1996a, 1996b; Pfleeger et al. , 2011). However, there

### 27 are no available data on adverse reproductive impact s to terrestrial plants from orthosulfamuron residues due to spray drift.



## C. Degradate Toxicity

Toxicity and risk from orthosulfamuron degrad ates is an area of significant uncertainty. As discussed in the environmental fate section (S ection VI), several degradates may form via hydrolysis, aerobic aquatic metabolism, and anaerobi c aquatic metabolism, yet there are no data on them. There is an exposure concern for these degradates due to the potential mobility and formation rates relative to th e parent chemical. Acute oral rat toxicity study on DOP urea resulted in an LD 50 of 

### 677 mg a.i./kg-bw (male, MRID 473 05223) indicating that DOP urea is more toxic to rats on an acute basis than parent orthosulfamuron. Degradates are discussed in more detail in Section XI, Stressors of Concern.



## D. Ecological Incidents

A preliminary review was made on July 19, 2011 of the Ecological Incident Information System (EIIS, version 2.1.1), which is main tained by the Agency’s Office of Pesticide Programs, and the Avian Monitoring Information System (AIMS), which is maintained by the American Bird Conservancy. No incidents were found in the EIIS or AIMS database.

In addition to possible incidents recorded in EI IS, additional incidents ma y be reported to the Agency in aggregated incident re ports. Pesticide registrants repor t certain types of incidents to the Agency as aggregate counts of incident s occurring per product pe r quarter. Ecological incidents reported in aggregate reports include t hose categorized as “minor fish and wildlife” (W-B), “minor plant” (P-B), a nd “other nontarget” (ONT) incident s. “Other nontarget” incidents include reports of adverse effects to insect s and other terrestrial invertebrates. For orthosulfamuron, no minor incidents were report ed in the database (accessed July 19, 2011).

In the risk assessment, these databases will be ch ecked again and any incidents reported will be further evaluated to determine if the reported incidents represen t current patterns of use for orthosulfamuron. Examples of additional considerations are mitigation ( e.g ., reduced application rates), product cancellations, and ch anges in use patterns th at have occurred si nce the date of the reported incident(s). The absence of reported inci dents should not be cons trued as the absence of incidents. Incident reports for non-target organisms typica lly provide information only on mortality events and plant damage . Sublethal effects in organi sms such as abnormal behavior, reduced growth and/or impaired reproduction are rarely reported, except for phytotox ic effects in terrestrial plants.



# VIII. Evaluation of Non

­ definitive Toxicity Values

Many of the acute terrestrial and aquatic animal st udies resulted in non-defi nitive toxicity values, meaning that the actual toxicity of the compound is “gre ater than” the LC 50 

### , and thus, unknown. This evaluation is specific to the active ingredient as the data for the TGAI may not be representative or predictive of toxicity for the end-use product.

### 28 Aquatic Animals In an effort to determine whether additional data are needed to evaluate risk to non-target aquatic fish and invertebrates, EFED conducted a compar ison of the non-definitive toxicity value to the estimated aquatic concentration (EEC). The Margin of Safety (MOS) is the ratio of LOC divided by the RQ (see below) and represents the factor that the RQ would need to be multiplied by to result in a risk concern. The maximum annua l application rate was used to calculate a conservative EEC value to compare to the toxicity data.

• The peak EEC using the lowest K d 

### and the Tier I Rice Model (M ay 8, 2007) resulted in a value of 57 μg/L (See Section XI. Identification of Stressors of Concern )

• In comparison, the lowest acute non-defin itive toxicity value for aquatic animals ( Daphnia magna ) is 97.3 mg a.i./L (EC 50 

### ).

The equation shown below is used to cal culate a margin of safety (MOS).

RQ = Peak EEC/LC 50



### • RQ=0.0006

• The LOC for acute exposure to listed aquatic organisms is 0.05

MOS=LOC/RQ

• For acute exposure to listed a quatic organisms, the MOS=83. In other words, the RQ would have to be 83 times higher than the cu rrent preliminary RQ to result in a risk

concern.

There were no mortalities or s ublethal effects in the nondefinitive acute aquatic studies. There are no reported incidents for or thosulfamuron Therefore, the ri sk to aquatic organisms is presumed to be low and for the TGAI and a dditional data are not needed at this time.

Birds and Mammals A similar exercise can be performed for bi rds and mammals using T-REX (v1.4.1 (US EPA, 2008) to model orthosulfamuron residues on terres trial plants and insects as an estimate of exposure to birds and mammals. The maximum app lication rate was used to conservatively estimate EECs for birds (20 g) and mammals (15 g). Using the same equations as above, the MOS for acute exposure to listed birds is 11 and the MOS for acute exposure to listed mammals is 33. 11 

### There were no mortalities in the nondefin itive acute aquatic studies and there were no

11 The peak EEC from T-REX for 20 g birds is 18.31 mg/kg-bw; the lowest acute non-defi nitive toxicity value for birds is 1,960 mg a.i./kg-bw (LD 50 ); the equation shown below is used to calculate a MOS; RQ = Peak EEC/LD 50; RQ=0.009;tThe LOC for acute exposure to listed birds is 0.1; MOS=LOC/RQ; for acute exposure to listed birds, the MOS=11. The peak EEC from T-REX for 15 g mammals is 15.33 mg/kg-bw; the lowest acute non-defi nitive toxicity value for mammals is 5,000 mg a.i./kg-bw (LD 50 ); the equation shown below is used to calculate a MOS; RQ = Peak EEC/LD 50 ; RQ=0.003; the LOC for acute exposure to listed mammals is 0.1; MOS=LOC/RQ; for acute exposure to listed mammals, the MOS=33.

### 29 sublethal effects. There are no reported incident s for orthosulfamuron. Th erefore, the risk to birds and mammals is presumed to be low and additional data for the TGAI are not needed at this time.



# IX. Ecosystems Potentially at Risk

The ecosystems potentially at risk may be extensive in scope; therefore, it may not be possible to identify specific ecosystems during the developmen t of a nation-wide ecol ogical risk assessment. However, in general terms, terrestrial ecosystem s potentially at risk could include the treated field and immediately adjacent areas that may receive drift or r unoff. Areas adjacent to the treated field could include cultiv ated fields, fencerows and hedgero ws, meadows, fallow fields or grasslands, woodlands, riparian habita ts, and other uncultivated areas.

Aquatic ecosystems potentially at risk include wa ter bodies adjacent to, or down stream from the treated field and might include impounded bodies such as ponds, la kes and reservoirs, or flowing waterways such as streams or rivers. For uses in coastal areas, aquatic habitat also includes marine ecosystems, including estuaries.



# X. Assessment Endpoints

Assessment endpoints represent the ac tual environmental value that is to be protected, defined by an ecological entity (species, community, or othe r entity) and its attrib ute or characteristics (USEPA, 1998). For orthosulfa muron, the ecological entities in clude the following: birds, reptiles, terrestrial-phase amphibians, mammals , freshwater fish, fres hwater aquatic-phase amphibians and invertebrates, estuarine/marine fish and invertebrates, terrestrial plants, insects, aquatic plants, and algae. The a ttributes for each of these entit ies include growth, reproduction, and survival.



# XI. Identification of Stressors of Concern

The identified transformation prod ucts in environmental fate studies include DBS acid, DBS amide, DB amine, o-desmethyl orthosulfamuro n, DOP urea, DOP amine, and o-desmethyl DOP urea. All of these degradates may form in aerobic and anaerobic aquatic environments. Appendix J provides structure, identity, and fate info rmation on the transformation products. Incomplete fate data are availabl e and other degradates or higher percentages of degradates could be observed in metabolism studies where unidentif ied unextracted residues made up 33 to 43% of radioactivity.

Residues of Concern for Drinki ng Water Consumed by Humans

The 2007 Health Effects Division (HED) risk assessm ents states, “Given that HED is unable to conclude all these degradates are significantly less toxic than the pare nt, the drinking water assessment should be based on total residues of orthosulfamuron and its major degradates.” (USEPA, 2007b). The major degradates of DBS acid, DOP urea, DB amine, and o-desmethyl

### 30 orthosulfamuron are considered residues of concern in drinking water for humans. 12



### O-desmethyl Orthosulfamuron

O-desmethyl orthosulfamuron was detected at 16-19% in metabolis m studies. Therefore, it may be found in both aerobic and anae robic environments and in soil, water, and sediment. The previous ecological risk assessment identified o-desmethyl orthosulfamu ron as a residue of concern for ecological organisms and indicated that it would be assumed to have equal toxicity as the parent compound because it retains the pa rent compound’s sulfamoylurea structural group (USEPA, 2006, D333514), see Figure 3 . As this degradate is a sulfonylurea, a total toxic residue (TTR) approach is used for evaluating risk for all taxa from exposure to the O-desmethyl degradate.

Orthosulfamuron O-desmethyl orthosulfamuron

Figure 3. Structures of Orthosulfamuron and O-desmethyl orthosulfamuron

DOP Urea and O-desmethyl DOP urea

DOP urea and o-desmethyl DOP urea are subs tituted ureas. Ureas are a common class of herbicides used on a large numbe r of agricultural crops. The DOP urea is a precursor to odesmethyl DOP urea (see Figure 4 ) and was observed at up to 78% of applied radioactivity in the hydrolysis study (pH 4 at 50 o 

### C), 47% of applied radioactivity in the aerobic aquatic metabolism study, and 19% of applie d radioactivity in the anaerobi c aquatic study. This indicates that exposure to aquatic and terrestrial organism s is possible as DOP urea will likely be present in paddy water and sediment in the rice pad dy and may form on food residues or in soil. Additionally, DOP urea was detected in soil and sediment in the aquatic field di ssipation study and estimated dissipation half-lives ranged from 30 to 37 days in sediment to 177 to 330 days in soil. 13 

### The absence of detections in water in the aquatic field di ssipation study may be related to the high limit of quantitation (LOQ) of 5 μg/L 14 

### , use of poor analytical methods 15 

### , the low

12 HED did not consider DOP amine and DBS amide as major degradates because they were only observed as major degradates in hydrolysis studies at 50 o C (Personal Communication with Richard Loranger, Christine Olinger, Karlyn Middleton, and Christina Swartz 08/17/2011).

13 Half-lives for degradates were calculated using the tim e point beginning with the hi ghest concentration of DOP urea measured in the identified media to the final sampli ng interval where the degradat e was observed and using the single first order degradation equation. Linear regression was used to fit the single first order model by taking the natural log of concentrations measured at each time point. Simultaneous formation and decline of DOP urea was not considered in the calculation and thus the estimated rate of degradation is likely slower than the actual value.

14 This LOQ is higher than some of the aquatic life benchmarks available for ureas. N

O NH S O O

NH O

NH

N N O

O N

NH S NH NH N N OH

O O O

O O

### 31 application rate (33.7% of the theoretical amount), and/or the frequency of sampling. While odesmethyl DOP urea was identified as a minor degradate, the only difference in structure between DOP urea and o-desmethyl DOP urea is a methyl group and the toxicity of these compounds was assumed to be similar. An analys is of available aquatic toxicity data on ureas with a similar structure to thes e degradates is presented in Appendix B . Vascular plant data indicate that orthosulfamuron is more toxic than ureas; howev er, ureas were an order of magnitude higher in toxicity than orthosul famuron for nonvascular plants. Additionally, orthosulfamuron concentrati ons in paddy water were estim ated to determine whether concentrations in water could be high enough to result in a risk concern (see Appendix F ). A preliminary estimate of peak orthos ulfamuron EECs using the lowest K d 

### and the Tier I Rice Model resulted in a value of 57 μg/L. Concentra tions of urea residues for maximum amounts of DOP urea, o-desmethyl DOP urea, and unextracted residues were estimated to range from 10 to 15 μg/L ( Appendix F ). Measured nonvascular plant Aquati c Life Benchmarks for ureas range from 2.4 to 80 μg/L. This indicates that total urea concentrations have the potential to be present at high enough to cause a risk concern for non-vascul ar aquatic plants. Therefore, data will be requested on DOP urea for nonvascul ar aquatic plants. Finally, acute and chronic Aquatic Life Benchmarks (ALB) 16 

### for some ureas are much lower than those for orthosulfamuron. Acute ALB of three ureas (diuron, fl uometuron, and linuron) are much lower than the benchmark for orthosulfamuron. The lower urea acute ALBs for fish were 200, 320, and 1500 μg/L and acute ALBs for invertebrates were 60, 80, and 110 μg/L . Acute ALBs for ureas indicate there is a small chance that a risk concern (for endangere d species only) could re sult for invertebrates (ALB/LOC = 60/0.5 = Toxicity endpoint of 120 μg/L; EEC/Toxicity Endpoint=15/120 = 0.13). 17 

### Chronic ALBs for ureas (range from 0.09 to 21,800 μg/L) are much lower than those for orthosulfuramuron (range from 6,100 to 6,500 μg/L ) and some are lower than the urea EECs of 10 to 15 μg/L; therefore, acute data for aquati c invertebrates and chronic data for fish and invertebrates on DOP urea are also needed. 18 

### Without data for DOP urea, risk estimates will be calculated using available data fo r urea herbicides. To estimate exposure to the ureas for aquatic organisms, an EEC will be estimated consid ering exposure to both DOP urea and o-desmethyl DOP urea and the EEC will be compared to effects data for DOP urea.

15 The ECMs may be adequate for successful ILV validation; however, the quality is currently unknown as the ILVs were conducted on ECMs that were not used in the st udy. Additionally, the LOQ was 0.02 mg/L (20 μg/L) for orthosulfamuron. This is higher than the LOQ needed as the lowest toxicity endpoint multiplied by the LOC is 0.2 μg/L. Finally, the not all major degradates were looked for in the study.

16 Benchmarks, developed for baseline risk assessments, are estimates of the concentrations below which pesticides are not expected to harm aquatic life. Each Aquatic Life Benchmark is based on the most sensitive, scientifically acceptable toxicity endpoint available to EPA for a given taxon (for example, freshwater fish) of all scientifically acceptable toxicity data available to EPA multiplied by the co rresponding level of concern of 0.5 for acute endpoints and 1.0 for chronic and plant endpoints. Aquatic life benchmarks may be found at http://www.epa.gov/oppefed1/ecorisk_ders/aquatic_life_benchmark.htm

. 17 See Appendix B for a summary of the species each ALB is based on.

18 Three of six chronic values ranged from 0.09 – 26 μg/L and were in the range of EECs estimated for ureas of 10 to 15 μg/L.

### 32 DOP Urea O-desmethyl DOP urea

Figure 4. Structures of DOP urea and O-desmethyl DOP urea

While EFED has uncertainty about the potential toxi city of the DOP urea degradate to terrestrial plants, a simple comparison of tier II plant toxic ity data for other phenyl urea herbicides (diuron, linuron, tebuthiuron and fluometron) indicate that the parent, orthosulfamuron, is likely more toxic or has similar toxicity to terrestrial plan ts than the DOP urea degradate (assuming that the DOP urea degradate is of equal toxicity to th e phenyl urea herbicides). Therefore, tier II terrestrial plant toxicity data ar e not required for DOP urea or o-de smethyl DOP urea at this time. Terrestrial plant data for urea herbicides are summarized in Appendix B

.

Data for DOP urea indicate that it is more toxic to mammals on an acute basis than the parent (acute oral LD 50 

### = 677 mg/kg-bw for DOP urea as compared to >5000 mg/kg-bw for orthosulfamuron). Additionally, T-REX version 1.4.1 was used to determ ine whether potential exposure to the ureas co uld be high enough to resu lt in a risk concern ( Appendix L ). While the ratios of EEC to the acute oral LD 50 

### for DOP urea (RQ=0.0029) was hi gher than the ratio of the EEC to the highest level tested in the acute oral study for orthosulfamuron (highest EEC/nondefinitive endpoint ratio < 0.0014), exposure was not high enough to result in a risk concern. Data are not available to eval uate and compare chr onic risk from exposure to DOP urea and odesmethyl DOP urea to parent orthosulfamu ron. The chronic NOAEC for linuron (12.5 mg/kgdiet), a phenyl urea, was used to estimate whether it was likely th at chronic toxicity to mammals could result from exposure to DOP urea and o-de smethyl DOP urea. A preliminary estimate of risk indicated that exposure was high enough to result in a risk concern ( Appendix L ) and risk due to exposure to DOP urea and o-desmestheyl DOP urea could be higher than risk due to exposure to orthosulfamuron (linuron endpoint/h ighest chronic EEC from T-REX = 2.69 versus highest RQ for orthosulfamuron of 1.4). Based on acute data on bird s, linuron is one of the more toxic herbicides of the phenyl urea class and toxicity of DOP urea may be overestimated using the linuron endpoint. Additionally, if a more realistic high estimate of the formation of DOP urea (47% based on the maximum radioactivity observed as DOP urea in the aerobic aquatic metabolism study) the estimated RQ drops to 1.54. Th is is in the range of RQs estimated for the parent. Additional mammalian toxicity data on DOP urea and o-desmethyl DOP urea are not needed at this time; however, potential for acute and chronic risk to terrestrial mammals due to exposure to the urea degradates wi ll be evaluated in the risk a ssessment based on available data, including data on urea herbicides. If additio nal uses are proposed resulting in increased exposure, data for DOP urea and o-desmethyl DOP urea may be needed for mammals.

Data are not available on DOP urea or o-de smethyl DOP urea for birds or terrestrial invertebrates. Data on urea herbicides we re compared to the toxicity endpoints for orthosulfamuron to determine whether it was likely that these degradates would be more toxic N 2 H NH N N O

O O

N H O

H 2 N N

N O OH

### 33 than orthosulfamuron. Forty-eight hour LD 50 

### values for the urea herb icides diuron, tebuthiuron, linuron, and monuron ranged from 100 to >145 μg/bee. The 48-hr hour LD 50 

### values for orthosulfamuron were >100 and >109.4 μg/bee. Ther efore, ureas are not expected to be more toxic to terrestrial invertebrates than parent orthosulfamuron. Twenty-nine avian 4-16 day LC 50 

### values were available for ur eas and values for linuron, diur on, tebuthiuron, fluometuron, and monuron and are lower (1700 to 4682 mg/kg-diet ) than those for orthosulfamuron (>4790 and >4980 mg/kg-diet). The only definitive 14-day LD 50 

### value was higher than the highest level tested for orthosulfamuron. All chronic repr oduction avian endpoints were lower for ureas (range: 42.8 to 100 mg/kg-diet) than for orthosul famuron (1280 mg/kg-diet). Therefore, it is possible that the acute and chro nic toxicity of DOP urea and o- desmethyl DOP urea is greater than the toxicity of orthosulfamuron. T-RE X version 1.4.1 was used to determine whether potential exposure to the ur eas could be high enough to result in a risk concern ( Appendix L ). While the ratios of EEC to the lowest urea e ndpoints available for birds (<0.01 to 0.05) was higher than the risk estimated for orthosul famuron (<0.01 to 0.01), exposure was not high enough to result in a risk concern for birds. Acut e and chronic risk to birds will be evaluated in the risk assessment using available data. If new uses are proposed resulting in increased exposure, data on the toxicity of DOP urea may be needed for birds.

DBS acid, DOP amine, DBS amide, and DB amine

DBS acid and DOP amine were observed at grea ter than 50% applied radioactivity (each individually) in fate studies. DB amine and DB S amide were detected at maximums of 1-13% in hydrolysis studies c onducted at 25 and 50 o 

### C and 1-4% in metabolism studies. Figure 5 shows the structures of these degradates. ECOSAR ve rsion 1.0 was used to estimate the toxicity of these degradates as no data were av ailable to evaluate their toxicity ( Table 6 ). ECOSAR is only used to prioritize the need for additional data on degradates. Data on the aniline and amide chemical classes were used to estimate toxicity e ndpoints (see the description of data in the Help section of ECOSAR). Very limited data sets we re available to develop the regressions for the compounds and there is much uncertainty in these estimated values; however, this is one of the best methods available to estimate ecological toxicity. DOP amine a nd DB amine were both identified to be potentially more toxic to a quatic animals than parent orthosulfamuron on a chronic exposure basis. They are also major de gradates and are likely to be present in the aquatic environment. DOP amine was a major degradate observed in th e hydrolysis study at a maximum of 53% at pH (11% at pH 7 at 50 o 

### C) with maximums observed at the final sampling interval indicating higher levels may have been observed if the study was conducted for a longer time frame. DB amine was observed at a maximum of 13% in the hydrolys is study at pH 9 (2% at pH 7 and 25 o 

### C and 11% at pH 7 50 o 

### C) with maximums observed at the final sampling interval indicating that higher percentages may have b een observed in a longer study. DB amine and DOP amine were not looked for in the aquatic fi eld dissipation study. EECs were estimated for DOP amine and DB amine using the molecular weight and maximum amounts observed in the aerobic aquatic metabolism study. EECs were es timated assuming maximum amounts of 1% and 34% ( e.g ., assuming unextracted residues were th e parent) for both DB amine and DOP amine. EECs ranged from 0.2 to 7 μg/L for DB amine and 0.3 to 9 μg/L for DOP amine and were at least 10x lower than the lowest estimated toxicity endpoints (50 to 949 μg/L). Estimated risk due to exposure to DOP amine and DB am ine is higher than risk due to exposure to orthosulfamuron; however, exposure would need to be 6 to 187 times higher for DOP amine and

### 34 10 to 358 times higher for DB amine to result in a risk concern and the exposure estimate is already very conservative due to the assumption that unextracted residues were the degradate of interest. Therefore, data on these degradates is not needed at this time; however, if exposure estimates for these degradates increases, data may be needed for future risk assessment and these may be considered residues of concern.

DBS Acid DOP Amine

DBS Amide DB Amine

Figure 5. Structures of DBS Acid, DOP Amine, DBS Amide and DB Amine

Table 6. Comparison of Measured Toxici ty Endpoints for Orthosulfamuron with Estimated Aquatic Toxicity Endpoints for DBS Acid, DBS amide, DB amine, and DOP amine (estimated using ECOSAR versioin 1).* Compound (compounds class used by ECOSAR) Estimated Toxicity Endpoint (mg/L) 96-hr FW fish

EC 50 /LC 50 48-hr Daphnid

LC 50 96-hr EC 50 Green Algae Fish Chronic Value Daphnid Chronic

Value Orthosulfamuron (measured) >122 >142 >97.3 >129 6.2 6.1 6.5

DBS acid (amide) 5.32+005 47315.2 16.6 3147.7 624.2 DBS amide (amide) 3754.3 852.5 2.9 22.2 11.3 DB amine (aniline, amide) 155.8 3.2 1.0 0.9 0.08

DOP amine (aniline) 78.9 2.4 9.2 0.4 0.05 *All toxicity endpoints were estimated using ECOSOAR version 1.0 except data in the first row for orthosulfamuron. When a chemical was in multiple chem ical classes the lowest endpoint from all estimates is shown. Bold values indicate that the endpoint was much lower than that measured for the parent. These toxicity 

### N

NH S O

O O

OH 

## N 2 H N N O

O

N

NH S NH 2 O

O O 

### N

NH 2 O

### 35 estimates are only used to prioritize wh ich degradates are likely a risk concer n and how they should be handled in the risk assessment. The estimated values may over or under estimate actual toxicity of the compounds. Appendix C provides the output from ECOSAR.



### Method of Estimating Exposure and Evaluating Risk for Degradates

To estimate exposure to compounds assumed to have a similar toxicity to the parent ( e.g ., odesmethyl orthosulfamuron for aquatic organism s and parent, DBS acid, DOP urea, DB amine, and o-desmethyl orthosulfamuron for human dri nking water exposure estimates), a total toxic residue (TTR) approach will be used by summing th e residues observed in fate studies and then estimating degradation rates based on the total summed residues. The TTR degradation rates will then be used to estimate e xposure in place of degradation rates for the parent alone. Data on organic-carbon normalized distribution coefficients is requested for degradates observed in high percentages in the fate studies (DBS acid 19 

### and DOP urea) and the lowest estimated K OC 

### will be used in modeling. The modeled total toxic resi due amounts will then be compared to toxicity endpoints for the parent. This approach is calle d the Total Toxic Residu e (TTR) approach. As discussed previously, EECs will be estimated for DOP urea and o-desmethyl DOP urea combined residues and compared to toxicity endpoints for DOP urea or data from the urea herbicides. Available data are not adequate to estimate half-lives in an aerobic aquatic system for the ureas; therefore, stability will be assumed unless more data are available to characterize this uncertainty. The applicatio n rate of the parent will be c onverted to a urea equivalents application rate using molecular we ight and the highest percentages of the ureas observed in fate studies. The estimated applicatio n rate along with available fate will be used in models to estimate an exposure concen tration for the ureas. Table 7 summarizes the different approaches for assessing risk to degradates for each taxa.

Table 7. Summary of residues of concern for different classes of organisms.

Transformation Product Is the transformation product a residue of concern? If yes, what approach will be used to evaluate potential risk due to exposure to degradate Aquatic Animals Aquatic Plants Terrestrial Vertebrates Terrestrial Invertebrates Terrestrial Plants

o-desmethyl orthosulfamuron Yes-TTR 1 Yes-TTR 1 Yes-TTR 2 Yes-TTR 1

DBS acid No No No DB amine No, at current

exposure

levels No No

DBS amide No No No No No DOP amine No, at current

exposure

levels No No No No

DOP urea Yes – EECs estimated for ureas and compared to toxicity endpoint for DOP

urea or urea herbicides Yes – EECs estimated for ureas

and compared to toxicity endpoint for DOP urea or urea herbicides No No o-desmethyl

DOP urea

19 DBS acid is a residue of concern for human healt drinking water assessments; therefore, this K OC would only be used in the human health drinking water assessment.

### 36 Abbreviation: TTR= Total toxic residue approach

1 Residues included in the TTR approach for these taxa are the parent and o-desmethyl orthosulfamuron.

2 Residues included in the TTR approach for these taxa are the parent, DBS acid, and DB amine based on HED analysis of residues of concern for humans. As these degradates are assumed to have similar toxicity to the parent and exposure estimates are not related to the fate data, the pr esence of these degradates do es not alter the estimate of risk for these taxa from that estimated for the parent alone. If one of these degradates is found to be more toxic than the parent or if the presence of these degradates could influence the estimate of exposure, this approach will be revisited.



### For terrestrial vertebrates, the residues of c oncern include the parent, DBS acid, DOP urea, DB amine, and o-desmethyl orthosulfamuron as thes e were the residues of concern identified for human health (USEPA, 2007b). While the TTR appr oach was the approach identified as the method to evaluate risk due to exposure to orth osulfamuron and major degradates other than the ureas for terrestrial vertebrate a nd invertebrates, fate data are not used in T-REX (unless foliar dissipation data are available 20 

### ), the model used to estimate terrestrial exposure. Therefore, even though a TTR approach was identified for terres trial animals the exposure estimates will not change. If this changes in the future, a more complete analysis of the residues of concern for terrestrial animals will be made.

Mixtures

Evaluation of pesticide environmental mixtures is beyond the scope of this assessment because of the myriad factors that cannot be quantified ba sed on the available data. Those factors include identification of other possible co-contaminants and their concentrations , differences in the pattern and duration of exposure among contamin ants, and the differential effects of other physical/chemical characteristic s of the receiving waters ( e.g. organic matter present in sediment and suspended water). Evaluation of factors that could influence additivity/synergism is beyond the scope of this assessment and the capabilities of the available data to allow for an evaluation. However, it is acknowledged that not consideri ng mixtures could over- or under-estimate risks depending on the type of interaction and factor s discussed above. The assessment will, however, analyze the toxicity of formul ated products (including formula tions involving more than one active ingredient) and will determine whether formulated products are more toxic than the technical grade active ingredient data used for assessing both direct and indirect risks. One registered product contains a co-pack of tw o separate herbicides, one contains 50% orthosulfamuron and the other 75% quinclorac, a quinolinecarboxylic acid herbicide. The products are mixed and applied rice.



# XII. Conceptual Model

For a pesticide to pose an ecological risk, it must reach ecological r eceptors in biologically significant concentrations. An exposure pathway is the means by which a pesticide moves in the environment from a source to an ecological recepto r. For an ecological pathway to be complete, it must have a source, a release mechanism, an environmental transport medium, a point of exposure for ecological receptors, an d a feasible route of exposure.

20 Foliar dissipation data are not available for orthosulfamuron.

### 37 The conceptual model for orthosulfamuron provides a written desc ription and visual representation of the predicted relationships be tween orthosulfamuron and degradates, potential routes of exposure, and the pr edicted effects for the assessment endpoint. A conceptual model consists of two major components: risk hypot hesis and a conceptual diagram (USEPA, 1998).

As discussed previously, one ecological risk assessment has been conducted by EFED for orthosulfamuron (USEPA, 2006, D333514). Potential for direct effects to aquatic vascular plants, non-vascular plants, and terrestrial plants were identified. Additionally, indirect effects to taxa that rely on plants for habitat an d food could be indirectly affected.



## A. Risk Hypothesis

A risk hypothesis describes the predicted re lationship among the stressor, exposure, and assessment endpoint response along with the rationa le for their selection. For orthosulfamuron, the following ecological risk hypot hesis is being employed for this national-level ecological risk

assessment:

Given the uses of orthosulfa muron and its environmental fa te properties, there is a likelihood of exposure to non-target terrestrial and/or aquatic organism s. When used in accordance with the label, orthosulfamuron and its degradates may result in adverse effects upon the survival, growt h, and reproduction of non-target terrestr ial and/or aquatic organisms. These nontarget organisms may include Federally-listed threatened and endangered species. Based on th e previous risk assessment and analysis supporting this problem formulation, direct effects are likely for mammals and for aquatic and terrestrial plants and indirect effects may result for all ot her taxa due to direct effects on plants. As some degradate toxicity data are not availa ble and were not evalua ted in the previous assessment, it is uncertain whether direct effect s are likely to occur for aquatic organisms.



## B. Conceptual Diagram

The conceptual model depicts the potential pa thways for ecological risk associated with orthosulfamuron use on rice. The conceptual model provides an overvi ew of the expected exposure routes for terrestrial and aquatic organisms.

The potential exposure pathways and effects of orthosulfamuron on aquatic environments are depicted in Figure 6 and for terrestrial environments in Figure 7

. Figure 8 depicts exposure from drinking water and inhalation to terrestrial vertebrates and invertebrates. Stressors of concern for aquatic animals include parent, o-desmethyl orthosulfa muron, DOP urea, and odesmethyl DOP urea. Stressors of concern for terrestrial animals include orthosulfamuron, odesmethyl orthosulfamuron, DBS acid, DB amine, DOP urea, and o-desm ethyl DOP urea. The stressors of concern for aquatic plants incl ude parent orthosulfamuron and o-desmethyl orthosulfamuron, DOP urea, and o-desmethyl DOP ur ea. The stressors of concern for terrestrial plants are orthosulfamuron and o-desmethyl orthosulfamuron. So lid arrows depict the most likely routes of exposure and effect s; dashed lines depict potential routes of exposure that are not considered likely for orthosulfamuron. Orthosulfamuron will enter the environment via direct

### 38 application to water and terrestrial environments when it is applied for dry-seeded rice. It may move off site via spray drift, runoff, leaching, vo latilization, release of paddy water, and use of paddy water as irrigation water. While orthosulfamuron’s va por pressure indicates it is semivolatile, it is not expected to volatize fr om water or moist soil (see discussion in Section IVC ). Additionally, the Screening Tool for Inha lation Risk (STIR) version 1.0 (November 23, 2010) indicates that exposure via inhalation is not likely to be a risk concern for birds and mammals ( Appendix E ). These results combined with th e estimated atmospheric half-life of less than two days indi cate that long range tran sport in the vapor phas e is not an exposure pathway of concern. Additionally, the K OA 

### , K OW 

### , and BCF indicate that orthosulfamuron is not likely to bioconcentrate or bioaccu mulate in aquatic or terrestri al organisms. Organic-carbon normalized distribution coefficients (K OC 

### ) values range from 217 to 2,330 L/kg- OC 

### indicating that orthosulfamuron has the potential to leach into groundwater and will be present at significant concentrations in some sediments; however, toxi city endpoints for aquatic invertebrates indicate that this exposure is not likely to be a risk concern. The Screening Imbibition Program (SIP) version 1.0, August 19, 2010 indicates that orthosul famuron has the potentia l to be present in drinking water (pH 7.0 and 8.5) at high enough concen trations to result in a risk concern ( Appendix E ). This is a highly conser vative evaluation as SIP assu mes that concentrations in drinking water could be at the level of sol ubility. Additionally, non-definitive acute endpoints for mammals and birds and definitive chronic endpoi nts were used in the model. Finally, surface and shallow ground water contaminated with orthos ulfamuron has the potenti al to be used as irrigation water and may result in exposure to terrestrial plants ( Appendix J ). Although orthosulfamuron may be applied as a granule or as a flowable, spray drift is only expected to result in significant exposure with broadcast applications (both aerial and ground spray) of the flowable formulations. Dry formulations that ar e applied as a flowable may result in significant spray drift exposure. As discussed previously, there are potential reproduc tive effects to plants.

### 39 *Spray drift is not expected to be a significant pathway of exposure for applications of granular materials.



### Figure 6. Conceptual model depicting stresso rs, exposure pathways, and potential effects to aquatic organisms from the use of orthosulfamuron to rice.

### 40 *Spray drift is not expected to be a significant pathway of exposure for applications of granular materials. See Figure 4 for drinking water and inhalation exposure pathways for terrestrial vertebrates and ingestion of residues in dew by terrestrial invetebrates.



### Figure 7. Conceptual model depicting stresso rs, generic exposure pathways, and potential effects to terrestrial organisms (terrestrial plants, terrestrial invertebrates, and dietary routes of exposure for terrestrial vertebrates) from the use of orthosulfamuron on rice.

### 41 *Spray drift is not expected to be a significant pathway of exposure for applications of granular materials.



### Figure 8. Conceptual model depicting stresso rs, drinking water and inhalation exposure pathways, and potential effects to terrestrial animals from the use of orthosulfamuron on rice.



# XIII. Analysis Plan

In order to address the risk hypot hesis, the potential for advers e effects on the environment is estimated. The use, environmental fate, a nd ecological effects of orthosulfamuron are characterized and integrated to assess the risks. This is accomplished using a risk quotient (ratio of exposure concentration to eff ects concentration) approach. A lthough risk is often defined as the likelihood and magnitude of a dverse ecological effects, the ri sk quotient-based approach does not provide a quantitative estim ate of likelihood and/or magnit ude of an adverse effect. However, as outlined in the Ov erview Document (USEPA, 2004), the likelihood of effects to individual organisms from partic ular uses of orthosulfamuron is estimated using the probit doseresponse slope and either the level of concern (d iscussed below) or actual calculated risk quotient value.

### 42 This analysis plan will be revisited and may be revised depending upon the information submitted by the public in response to the opening of the Registration Review docket for orthosulfamuron.



## A. Measures of Exposure

In order to estimate risks of orthosulfamuron e xposures in aquatic and te rrestrial environments, all exposure modeling and resulting risk conclusi ons will be based on maximum application rates and methods cited in Table 1 and will be estimated for each use of orthosulfamuron. Measures of exposure are based on aquatic and terrestrial models that predict estimated environmental concentrations (EECs) of orthosulfamuron.

1. Exposure to Aquatic Organisms in the Rice Paddy

The EFED Tier 1 Rice Model ( v1.0, May 8, 2007) is used to estimate aquatic exposures for direct water use with conservative, maximum valu es that represent high exposure sites for rice use. Each of these sites repr esents a water body holdi ng a 10-cm water depth. When a pesticide is applied to a water body, the model assumes th at it will instantaneousl y partition between a water phase and a sediment phase based on th e partition coefficient of the chemical. 21 

### The formula of the Tier I Rice Model v1.0 is as follows:

The model does not account for pesticide degrada tion, mass transfer betw een the aqueous phase and the sediment, volatilization, dilution, or ot her dissipation processes. The sediment interaction depth was determined by calibrating the model to maximum residues measured in paddy water in dissipation studies. Pesticide de gradation, mass transfer, volatilization, dilution and other dissipation processes may have occurred in those datasets but data were calibrated to the maximum measured residues which would redu ce the influence of these processes. The model was not evaluated or calib rated for concentrations measured in sediment and does not estimate a sediment concentration. Guidance fo r using the Tier I Rice Model may be found on the U.S. Environmental Protection Agency (EPA) Water Models web-page (USEPA, 2007b).

21 Orthosulfamuron Kd values range from 2.5 to 20.7 L/kg and K OC values range from 215 to 2145 L/kg-OC (MRID 46578971).

### 43 Refinements may be made to EFED’s Tier I Rice Model to incorporate aerobic soil and aerobic aquatic degradation into the equations discu ssed above to arrive at acute and chronic concentrations and to estimate a concentration in water after a specified holding period. The following equation may be used to estimate the concentration in paddy water as a function of time:

C w, t 

### = C w, 0 

### e (-kt)



### Where Cw, t = the concentration in water at time, t Cw, 0 = the concentration in wa ter at application or time of zero (calculated using the Tier I Rice Model) e = base of natural logarithm k = first-order rate constant (1/days) t = time after application (days)

When two applications are modeled, the initial c oncentration in the water after each application is estimated using the Tier I Rice model, degrad ation/dissipation is modeled from the date of application for every day after for a specified time. Concentrations in water from the first and second applications are added to determine the total concentration in water over time for each day. Acute concentrations are reported at the maximum concentration fo r the given scenario. Chronic concentrations are taken as the average daily concentration with days from the first application to the number of days specified for paddy water. An estimate of exposure for tail water is made if paddy water is re quired to be held for a number of days after application and represents the concentration in wate r when paddy water is released.

2. Exposure to Terrestrial Animals via Residues on Food Items

Exposure estimates for terrestrial an imals assumed to be in the targ et area or in an area exposed to spray drift are derived using the T-RE X model (version 1.4.1, 10/ 09/2008). This model incorporates the Kenaga nomogr aph, as modified by Fletcher et al. (1994), which is based on a large set of field residue data. The upper limit values from the nomograph represent the upper bound of residue values from actual field meas urements (Hoerger and Kenaga, 1972). The Fletcher et al. (1994) modifications to the Kenaga nomograph are based on measured field residues from 249 published research papers, incl uding information on 118 species of plants, 121 pesticides, and 17 chemical classes (Fletcher et al. , 1994).

3. Exposure to Terrestrial Animals via Drinking Water

Based on results from SIP, exposure to birds an d mammals via exposure in drinking could result in a risk concern. Therefore, EECs will also be estimated for terrestrial organisms that may consume dew, or puddles. Methods of estimati ng exposure via these pa thways are currently under development. If EECs for dew and puddles ar e lower than those for use of paddy water as a drinking water source, than risk due to cons umption of paddy water will be evaluated using body weight-specific consumption rates and the c oncentration of orthos ulfamuron residues in

### 44 water bodies (USEPA, 1993, 1998, 2008a).

4. Exposure to Terrestrial Plants from Spray Drift

EECs for terrestrial plants inha biting dry and wetland areas are derived using TerrPlant (version 1.2.2, 12/26/2006). This model uses estimates of pestic ides in runoff and in spray drift to calculate EECs. EECs are based upon solubilit y, application rate and minimum incorporation depth. For rice uses, only exposure to spray drif t is assessed. AgDRIFT may also be used to assess exposure to spray drift.

5. Exposure to Terrestrial Plants from Residues in Irrigation Water

Non-target crops may be exposed to contaminat ed irrigation waters from surface water or shallow ground water containing orthosulfamuron. The potential risks to plants when exposed to irrigation water contaminated with orthosulfamu ron will be estimated for both ground water and surface water irrigation sources. The EEC for ground water will be calculated using the Tier 1 SCIGROW model while that for surface water will be calculated using the Tier I Rice Model from the scenario yielding the highest EECs. Co mparisons will be made to the most sensitive endpoint from the vegetative vigor study assuming that runoff of irrigatio n water does not occur.

6. Exposure to Aquatic Organisms based on Monitoring Data

Available monitoring data will be used to quali tatively characterize exposure and compare with modeling results. The Agency is aware of monitoring conducted by Federal and state agencies and this route of exposure will be considered in the assessment to the extent that data on orthosulfamuron are available.

7. Exposure to Spray Drift

Two spray drift models, AgDisp and AgDRIFT, ar e used to assess expos ures of aquatic and terrestrial organisms to orthosulfamuron deposited in terrestrial and aquatic habitats by spray drift. AgDrift (version 2.01; da ted 5/24/2001) is the model most commonly used to simulate spray drift into terrestrial and aquatic envir onments. AgDisp (versi on 8.13; dated 12/14/2004) (Teske and Curbishley, 2003) is used when a parame ter needs to be modeled that is not available in AgDRIFT. Spray drift analysis will be an important part of the an alysis in defining the potential area of effects for endangered species.



## B. Measures of Effect

Ecological effect data are used as measures of direct and indirect effects to biological receptors. Data are obtained from registrant-submitted studies or from literature studies identified by ECOTOX. The ECOTOXicology databa se (ECOTOX) will be searched in order to provide more ecological effects data to bri dge existing data gaps. ECOTOX is a source for locating single chemical toxicity data and potential chemical mi xture toxicity data for aquatic life, terrestrial plants, and wildlife. ECOTOX wa s created and is maintained by the USEPA, Office of Research

### 45 and Development, and the National Health and Environmental Effects Research Laboratory's Mid-Continent Ecology Di vision (USEPA, 2009a).

Information on the potential effects of orthosulfa muron on non-target animals is also collected from the Ecological Incident Information Syst em (EIIS) (USEPA, 2007a). The EIIS is a database containing adverse effect (typically mo rtality) reports on non-target organisms where such effects have been associated with the use of pesticides.

Where available, sublethal effects observed in both registrant-submitted and open literature studies will be evaluated qualitatively. Such effects have included behavioral changes ( e.g. , lethargy, changes in coloration and effects olfaction). Quantitativ e assessments of risks, though, are limited to those endpoints that can be directly linked to the Agency’s assessment endpoints of impaired survival, growth and reproduction.

The assessment of risk for direct effects to non-target organisms ma kes the assumption that toxicity of orthosulfamuron to bi rds is similar to terrestrial-phase amphibians and reptiles. The same assumption is made for fish and aquatic-phase amphibians.

The acute measures of effect used for animal s in this screening-level assessment are the LD 50 

### , LC 50 

### and EC 50 

### . LD stands for "Lethal Dose", and LD 50 

### is the amount of a material, given all at once, that is estimated to cause the death of 50% of the test organisms. LC stands for “Lethal Concentration” and LC 50 

### is the concentration of a chemical that is estimated to kill 50% of the test organisms. EC stands for “Effective Concentration” and the EC 50 

### is the concentration of a chemical that is estimated to produce a specific effect in 50% of the test organisms. Endpoints for chronic measures of exposure for liste d and non-listed animals are the NOAEL/NOAEC and NOEC. NOAEL stands for “No Observed-Adverse-Eff ect-Level” and refers to the highest tested dose of a substance that has been reported to have no harmful (adverse) effects on test organisms. The NOAEC ( i.e. , “No-Observed-Adverse-Effect-Concen tration”) is the highest test concentration at which none of the observed effect s were statistically different from the control. The NOEC is the No-Observed-Effects-Concen tration. For non-listed plants, only acute exposures are assessed ( i.e. , EC 25 

### for terrestrial plants and EC 50 

### for aquatic plants); for listed plants, either the NOAEC or EC 05 

### is used.



## C. Integration of Exposure and Effects

Risk characterization is the in tegration of exposure and ecologi cal effects characterization to determine the potential ecological risk from the use of orthosulfamuron on rice, and the likelihood of direct and indirect e ffects to non-target organisms in a quatic and terrestrial habitats. The exposure and toxicity effects data are integrat ed in order to evaluate the risks of adverse ecological effects on non-target species. For th e assessment of orthosulfamuron risks, the risk quotient (RQ) method is used to compare exposur e and measured toxicity values. EECs are divided by acute and chronic t oxicity values. The resulting RQs are then compared to the Agency’s LOCs (USEPA, 2004). These criteria ar e used to indicate when orthosulfamuron’s uses, as directed on the label, have the potential to cause adverse direct or indirect effects to nontarget organisms. As noted previously, where data are lacki ng on the toxicity of orthosulfamuron, risk will be presumed.

### 46 1. Deterministic and Probab ilistic Assessment Methods

The quantitative assessment of risk will primar ily depend on the deterministic point-estimate based approach described in the risk assessment. An effort may be made to further describe risk using probabilistic tools that the Agency has de veloped. These tools have been reviewed by FIFRA Scientific Advisory Panels and have b een deemed as appropria te means of refining assessments where deterministic approaches have identified risks.



## D. Endangered Species Assessments

Consistent with the Agency’s responsibility under the Endangered Sp ecies Act (ESA), the Agency will evaluate risks to Federally-listed th reatened and/or endangere d (listed) species from registered uses of orthosulfamuron. This a ssessment will be conducted in accordance with the Overview Document (USEPA, 2004), provis ions of the ESA, and the Services’ Endangered Species Consultation Handbook (USFWS/NMFS, 1998).

The action area is used to identify all listed (t hreatened and endangered) species and designated critical habitat that could be affected by the Federal acti on. The Federal action is the authorization or registration of pesticide use or uses as descri bed on the label(s) of pesticide products containing a partic ular active ingredient. The action area is defined by the Endangered Species Act as, “all areas to be affected direct ly or indirectly by th e Federal action and not merely the immediate are involved in the action” (50 CFR §402.2). Based on an analysis of the Federal action, the action area is defined by the actual and pote ntial use of th e pesticide.

In the case of nationwide ecological risk assessment conducted for orthosulfamuron under Registration Review, the action area will encompass the entire United States and its territories. The purpose of defining the action area as the entire United States and its territories is to ensure that the initial area of consider ation encompasses all areas where orthosulfamuron may be used now and in the future, including the potential for off-site transport via spray drift and downstream dilution. Additionally , the concept of a nationwide action area takes into account the potential for direct and indir ect effects and any poten tial modification to critical habitat based on ecological effect measures associated with reduction in survival, growth, and reproduction, as well as the full suite of sublethal effects available in the effects literature. It is important to note that the nationwide action area does not imply that direct and/or indirect effects and critical habitat modification are expected to or are likely to occur over the full extent of the action area, but rather to identify all listed species and critic al habitat that may potentially be affected by the action. The Agency will use more rigorous analys is including considera tion of available land cover data, toxicity data, and exposure information to determine areas where individual listed species and designated critical ha bitat may be affected or modifi ed via endpoints a ssociated with reduced survival, growth, or reproduction.



## E. Human Health Drinking Water Assessment

In order to bring the drinking water assessmen t up to date with current data, models and simulation model guidance, a new drinking water assessment will be conducted to support future

### 47 human health dietary risk assessments of ort hosulfamuron. The drinking water assessment will incorporate model estimates of orthosulfamu ron and its major degradates (using a TTR approach) in surface water and groundwater. C oncentrations of orthosulfamuron and major degradates in surface waters will be estimated using the Tier I Rice Model (see description above).

An Estimated Drinking Water Concentration (EDWC) of orthosulfamuron and its major degradates in groundwater will be estimated using EFED’s Tier I aquatic model SCIGROW (Screening Concentration in Ground Water, vers ion 2.3; 8/8/2003). SCIGROW is a regression model used as a screening tool to estimate pe sticide concentrations found in ground water used as drinking water. The output of SCIGROW represents the c oncentrations that might be expected in shallow unconfined aquifers under sa ndy soils, which is representative of the ground water most vulnerable to pesticide contamination likely to serve as a dr inking water source.

The drinking water assessment will also include available surface and ground water monitoring data with consideration of change s in use patterns that may have o ccurred. States are encouraged to submit monitoring data for review.



## F. Endocrine Disruptor Screening Program

As required by FIFRA and FFDCA, EPA reviews nu merous studies to a ssess potential adverse outcomes from exposure to chemicals. Collectiv ely, these studies include acute, subchronic and chronic toxicity, including assessments of carcinogenicity, neurotox icity, developmental, reproductive, and general or systemic toxicit y. These studies include endpoints which may be susceptible to endocrine influe nce, including effects on endocr ine target organ histopathology, organ weights, estrus cyclicity, sexual maturati on, fertility, pregnancy rates, reproductive loss, and sex ratios in offspring. For ecological ha zard assessments, EPA evaluates acute tests and chronic studies that assess growth, developm ental and reproductive effects in different taxonomic groups. As part of its reregistration decision

, EPA reviewed these data and selected the most sensitive endpoints for relevant risk assessment scenarios from the existing hazard database. However, as required by FFDCA sec tion 408(p), orthosulfamuron is subject to the endocrine screening part of the Endocrine Disruptor Screenin g Program (EDSP).

EPA has developed the EDSP to determine whet her certain substances (including pesticide active and other ingredients) may have an effect in humans or wildlife similar to an effect produced by a “naturally occurring estrogen, or ot her such endocrine effects as the Administrator may designate.” The EDSP employs a two-tiered approach to making th e statutorily required determinations. Tier 1 consists of a battery of 11 screening assays to identify the potential of a chemical substance to interact with the estrog en, androgen, or thyroid (E, A, or T) hormonal systems. Chemicals that go through Tier 1 scr eening and are found to have the potential to interact with E, A, or T hormonal systems will pr oceed to the next stage of the EDSP where EPA will determine which, if any, of the Tier 2 tests are necessary based on the available data. Tier 2 testing is designed to identify a ny adverse endocrine-related effects caused by the substance, and establish a dose-response relationship between the dose and the E, A, or T effect.

### 48 Under FFDCA section 408(p), the Agency must screen all pesticide chemicals. Between October 2009 and February 2010, EPA issued test orders/data call-i ns for the first group of 67 chemicals, which contains 58 pesticide ac tive ingredients and 9 inert ingredients. Orthosulfamuron is not among the group of 58 pesticid e active ingredients on th e initial list to be screened under the EDSP. Accordingly, as part of registration review, EPA will issue future EDSP orders/data call-ins, requiring the su bmission of EDSP screening assays for orthosulfamuron. For further info rmation on the status of the ED SP, the policies and procedures, the list of 67 chemicals, future lists, the test guidelines and the Tier 1 screening battery, please visit our website: http://www.epa.gov/endo/

.



# XIV. Preliminary Identification of Data Gaps

A. Fate

Several fate studies are needed to better char acterize the environmental fate and transport of orthosulfamuron. The studies listed below will decrease the uncertainty in determining the potential exposure to the pesticide.

• Hydrolysis (OPPTS 22 

### Guideline 835.2120) for parent at pH 5 and 25 o 

### C

• Aerobic Soil Metabolism (OPPTS Guideline 835.4100) for parent

• Anaerobic Aquatic Metabolism (OPP TS Guideline 835.4400) for parent

• Batch Equilibrium (OPPTS Guideline 835.1240) for the orthosulfamuron degradates DBS acid and DOP urea.

• Aquatic Field Dissipation (OPPTS Guideline 835.6200) for parent

• Environmental Chemistry Methods for So il and Water (OPPTS Guideline 850.7100) for parent and major degradates to sup port aquatic field di ssipation study

• Environmental Chemistry Methods for Wa ter (OPPTS Guideline 850.7100) for parent and major degradates

Table 8 summarizes the fate data requirements for orthosulfamuron. A ra tionale discussing the need for each study is also provided below.

Table 8. Summary of Submitted Environmenta l Fate Studies, Study Classifications and Data Gaps for Orthosulfamuron and Its Degradates
OPPTS Guideline MRID Study Classification Comments on Study Classification Data Gap? Comments

Hydrolysis 835.2120 (161-1) 46219015 Supplemental Values may be used in risk assessment. Yes Data are needed at pH 5 at 25 o C.
46578970 Unacceptable N o material balance. Did not follow degradates.
46219016 Supplemental Study conducted at 50 o C

22 Office of Prevention, Pollution, and Toxic Substances (O PPTS) is not the Office of Chemical Safety and Pollution Prevention (OCSPP); however, the guidelin es still reference the OPPTS office.

### 49 OPPTS Guideline MRID Study Classification Comments on Study Classification Data Gap? Comments

Aqueous Photolysis 835.2370 (161-2) 46588509 Supplemental Many deficiencies but adequate to determine that this is not a significant pathway of degradation. No None

Soil Photolysis 835.2410 (161-3) Not applicable Not applicable None No 40 CFR Part 158.1300 does not require this study for aquatic uses. Aerobic Soil Metabolism 835.4100 (162-1) Not applicable Not applicable None Yes No data submitted.

Anaerobic Soil Metabolism 835.4200 (162-2) Not applicable Not applicable None No 40 CFR Part 158.1300 does not require this study for aquatic uses.

Aerobic Aquatic Metabolism 835.4300 (162-4) 46219017 Supplemental Unextracted residues made up to 33% applied radioactivity and a reasonable attempt was not made to fully extract all radioactivity. No There is still some uncertainty as to the identity of the unextracted residues. Providing more information on the identity of the unextracted residues may reduce the duration of the estimated half-life and/or change maximum amounts of degradates observed. 46588508 Unacceptable Co nducted outd oors with fluctuation temperatures and sunlight.

Anaerobic Aquatic Metabolism 835.4400 (162-3) 46578967 Supplemental Numerous deficiencies including use of soil instead of sediment. Yes Available data do not fulfill the guideline requirement due

to numerous deficiencies.

Sorption coefficients 835.1240 (163-1) 46219074 Supplemental Many deficiencies including use of foreign soil. Values may be used quantitatively. Yes Batch equilibrium data are needed to estimate exposure to DBS acid and DOP urea. These were the residues with the highest percentages observed in fate studies. Data are not needed for the parent. 46578971 Supplemental Material balance and stability only determined in supplementary experiment. Values may be used quantitatively. Aged Column Leaching 46219018 Acceptable None No None

Soil Column Leaching 46578968 Supplemental Only one ring labeled. No None

### 50 OPPTS Guideline MRID Study Classification Comments on Study Classification Data Gap? Comments

Aquatic Field Dissipation 835.6200 46578985 Supplemental Associated ECM and ILV are not available for soil and water. Recoveries in field spikes were low and variable. Yes A study is needed with an associated sediment/soil and water ECM and ILV. If the storage stability data indicate that compounds are not stable

during storage, field spikes

should be obtained and extracted with each set of samples collected.

Bioconcentration
Factor 850.1730 46588507 Acceptable None No None

Environmental Chemistry Method: Water 850.7100 None submitted Not applicable None Yes An ECM and ILV are needed with a limit of quantitation (LOQ) for the parent below 0.2 μg/L that may be used in monitoring. 2 A method is also

needed to support an aquatic field dissipation study. The

method may be the same method. All major degradates should be included in the

method and have an associated LOQ and limit of detection (LOD).

Environmental Chemistry Method: Soil and sediment 850.7100 None submitted Not applicable None Yes An ECM and ILV are needed with associated LOQ and LOD for all major degradates

for soil and sediment. The

method(s) is needed to support the aquatic field dissipation study. Abbreviations: ECM=Environmental Chemistry Method; ILV=independent laboratory Validation

1 Water and sediments were not fully characterized and collection procedures (sampling depth, temperature, dissolved oxygen content, and microbial biomass) were not reported. Unextracted residues were 43%. Limit of quantitation not reported. 2 The LOQ was based on the NOAEC for aquatic vascular plants (NOAEC = 0.00026 mg a.i./L) and an LOC of 1 (MRID 46578939 and 46578940).



### 1. Rationales for Requesting Fate Studies

• Hydrolysis (OPPTS Guideline 835.2120) for parent at pH 5 and 25 o 

### C

Data are not available to determine the rate of hydrolysis for the parent compound at 25 o 

### C and pH 5. A preliminary study at 50 o 

### C and pH 4 indicates that significant hydrolysis may occur at low pH (MRID 46219015). Therefore, this study is needed to characterize the potential for hydrolysis in the aquatic environment at low pH. Additionally, this is a standard data requirement for outdoor use patt erns (40 CFR Part 158.1300).

### 51 • Aerobic Soil Metabolism (OPPTS Guideline 835.4100) for parent

This is a standard data requirement for terrestrial and aquatic use patterns and no data have been submitted to support this data requirement (40 CFR Part 158.1300). Data are needed to identify potential degradates and to better understand the potential for aerobic soil metabolism when orthosulfamuron is applied to dry soils.

• Anaerobic Aquatic Metabolism (OPP TS Guideline 835.4400) for parent

The available anaerobic aquatic metabolism study (MRID 46578967) has num erous deficiencies including the following:

• Unextracted residues ranged from not detected to 43% applied radi oactivity. Reasonable attempt to extract all residues was not made.

• Soils instead of sediment were used in the study.

• Microbial biomass was not determined in soil or water.

• Limit of quantitation not reported.

• Collection procedures (sampling depth) and temperature, dissolved oxygen content, and microbial biomass were not repor ted for water or sediment.

The study is the only study available examining anaerobic metabolism rates and does provide some useful information on the identity of anaerobic metabolites. Based on the multiple uncertainties with the available study, a study is still needed to accurately predict anaerobic aquatic metabolism rates and potential transf ormation products for anaerobic metabolism.

• Batch Equilibrium (OPPTS Guidelin e 835.1240) for DBS acid and DOP urea

The human health risk and ecologi cal risk assessments identified all major degradates as residues of concern for orthosulfamuron. Column leachi ng studies of aged orthosulfamuron indicated that some degradates (DBS acid, DBS amide, a nd o-desmethyl orthosulfa muron) are capable of greater mobility than the parent and are more likely to leach to ground water (MRID 46219018). DBS acid was a major degradate in hydrolysis , aerobic aquatic, and anaerobic aquatic metabolism studies where it was detected at maxi mums of 86%, 61%, and 39% of applied parent equivalents, respectively. DOP urea was a major degradate in hydrolysis, aerobic aquatic, and anaerobic metabolism studies where it was detected at maximums of 78% at pH 4, 47%, and 12% of applied parent equivalents, respect ively. Additionally, EPIsuite estimated K OC 

### values for these degradates were 0.09 and 53 L/kg-OC, sugges ting that they have th e potential to be more mobile than the parent ( Appendix A ). Therefore, data on the sorption coefficients of these degradates are needed to estimate concentrations of total toxic residues in water. O-desmethyl orthosulfamuron is expected to have similar mobili ty to the parent; therefore, data on the parent compound may be used to estimate exposure. DB S amide was detected at a maximum of 10% in one hydrolysis study and was a minor degradate in all other studies; therefore, data were not requested for this degradate. O-desmethyl DOP urea is a minor degradate that is a residue of concern for some aquatic organisms. The only difference in structure between DOP urea and odesmethyl DOP urea is a methyl group; therefore, data on DOP urea may be used to predict exposure for o-desmethyl DOP urea. DOP amine was only a major degradate in the hydrolysis

### 52 study conducted at pH 9 and was a minor degradate (<1% applie d radioactivity) in aerobic and anaerobic systems and DOP amine was not identifi ed as a residue of concern for human health; therefore, data are not needed for DOP amine.

• Aquatic Field Dissipation (OPPTS Guideline 835.6200)

• Environmental Chemistry Methods for So il and Water (OPPTS Guideline 850.7100) to support aquatic field dissipation study

This is a standard data requirement for terrestrial and aquatic use patterns and submitted data are not adequate to fulfill this requirement (40 CF R Part 158.1300). Storage stability data for the submitted study did not demonstrate stability of the parent and transformation products for the maximum storage interval of test samples. Re coveries of field fortifications ranged from 51- 82% for orthosulfamuron, 48-92% for DOP urea (IR7825), and 16-68% for DBS acid (IR7863). 23 

### Additionally, environmental chemistr y methods and associated independent laboratory validations are not ava ilable for the methods used in th e aquatic field dissipation study and this is a requirement for accepta ble aquatic field dissipation studies. 24 

### Finally, the aquatic field dissipation study did not look for all major degradates and transformation products identified as residues of concern and limit of qu antitations (LOQ) for some residues were high. An aquatic field dissipation study is needed wi th associated environmental chemistry methods with LOQ that are low enough to c over the levels of degradates a nd the parent that could result in a risk concern ( e.g ., toxicity endpoint x LOC). The method should be evaluated by an independent laboratory. If storage stability or recoveries from extrac tion methods are poor or variable, a method should be used to correct fo r these issues in the study. For example, field spikes could be performed with the collection of each set of samples and matrix spikes or surrogate internal standards 25 

### could be used to m onitor extraction recoveries in the lab. The current study may be found to be adequate to fulfill the guideline requirement for the current proposed uses if ECM and associated ILV are provi ded and the issues with the variable and low recoveries of field spikes samples and storage stability studies are addressed.

• Environmental Chemistry Methods for Water (OPPTS Guideline 850.7100)

An ECM and ILV are needed with a limit of qu antitation (LOQ) for the parent below 0.2 μg/L that may be used in monitoring. LOQ for residu es of concern should be low enough to cover the concentration that could result in a risk concern ( e.g ., toxicity endpoint multiplied by the LOC). A method and associated ILV is also needed to support an aquatic field dissipation study and the method evaluated must be the same method used in the aquatic field dissipation study. One method may be used to fulfill both data needs. All major degradates should be included in the method and have an associated LOQ and limit of detection (LOD).

23 See Table 13 on page 20 of data evaluation record for MRID 46578985.

24 Method validation studies were available for orthosulfamuron and IR7825. Samples were shaken in dichloromethane, decanted, and shaken again. Ex tracts were combined, concentrated, reconstituted in acetonitrile:aqueous NaHCO 3 , and analysis by LC/MS/MS. Field samples were analyzed directly using LC/MS/MS. However, this is not the method used for study samples.

25 Surrogate internal standards are compou nds that are similar in chemical com position to the analyte of interest and are spiked into each sample prior to pr eparation and analysis. They are used to evaluate matrix interference and/or extraction method quality for each sample or batch of samples and are a method of dealing with variable extraction recoveries.

### 53 

## B. Effects

Several ecological effects studies on orthosulfamuron are needed to better assess the potential risk of orthosulfamuron exposur e to non-target organisms. The studies listed below should be submitted to increase certainty in the risk estimat ion. Effects studies need for the degradates are discussed in Section B.3..

• Special Study for Non-Target Plant Repr oductive Toxicity (Non-Guideline) for TEP

• Freshwater Fish-Acute Toxi city (850.1075) with the TEP

• Freshwater Invertebrates-Acute Toxicity (850.1010) with the TEP

• Terrestrial Plant Toxicity-Tie r II Vegetative Vigor (850.4150)

The following studies are standard data requiremen ts for orthosulfamuron; however, data are not requested for these at this time.

• Avian Acute Oral Toxicity Test with a Passerine Species (850.2100)

• Saltwater Fish-Acute Toxici ty (850.1075) with the TEP

• Saltwater Invertebrates-Acute T oxicity (850.1025, 850.1035) with the TEP

• Whole sediment survival, growth, a nd reproduction tests with TGAI and Chironomus

tentans , Leptocheirus plumulosus , and Hyalella Azteca

If application rates change or new uses are pr oposed in the future, then these data may be required.

Table 9 summarizes the effects data requirements for orthosulfamuron. Rationales discussing the data requirements are provided after Table 9

.
Table 9. Summary of Submitted Ecological Effects Studies and Data Gaps for Parent Orthosulfamuron

OPPTS Guideline MRID Study Classification Data Gap? Comments for Data Gap

Terrestrial Animals

850.2100 Avian Oral Toxicity – Waterfowl or Upland Game Bird 46260107 Acceptable No

850.2100 Avian Acute Toxicity - Passerine No Data NA No See discussion below regarding acute toxicity for passerines.

850.2200 Avian Dietary Toxicity 46219040 Acceptable No

850.2300 Avian Reproduction 46578949

46578950 Acceptable Acceptable No

### 54 OPPTS Guideline MRID Study Classification Data Gap? Comments for Data Gap

850.3020 Honeybee Acute Contact Toxicity 46219046 Acceptable No

Aquatic Animals

850.1075 Freshwater Fish-Acute Toxicity 46219042 Acceptable Yes An additional study for the TE P is required as the use pattern includes direct application to water (rice cultivation).

850.1075 Saltwater Fish-Acute Toxicity 46578951 Acceptable No

850.1010 Freshwater Invertebrates-Acute Toxicity 46219044 Acceptable Yes An additional study for the TE P is required as the use pattern includes direct application to water (rice cultivation).

850.1025 850.1035 Saltwater Invertebrates-Acute Toxicity 46578957

46578952 Acceptable No

850.1300 Freshwater Invertebrates-Life Cycle Test 46578956 Acceptable No

850.1350 Saltwater Invertebrates-Life Cycle Test 46578954 Supplemental No

850.1400 Freshwater Fish-Early Life Stage Test 46578953 Acceptable No

850.1500 Fish-Life Cycle Test No Data NA No

Plants

850.4100 Terrestrial Plant Toxicity-Tier 1 Seedling Emergence 46578941 Acceptable No

850.4225 Terrestrial Plant Toxicity-Tier 2 Seedling Emergence 46578941 Acceptable No

850.4150 Terrestrial Plant Toxicity-Tier 1 Vegetative Vigor 46578942 Supplemental No Study classified as supplemental due to lack of a NOAEC for several species. A Tier II study with a definitive NOAEC is needed.

850.4150 Terrestrial Plant Toxicity-Tier 2 Vegetative Vigor 46578942 Supplemental Yes Study classified as supplemental due to lack of a NOAEC for several species.

### 55 OPPTS Guideline MRID Study Classification Data Gap? Comments for Data Gap

(Non-Guideline)Special Study-NonTarget Plant Reproductive Toxicity No Data Yes See rationale below.

850.4400Aquatic Plant GrowthAlgae 46578935

46578936 Supplemental Supplemental No

850.4400Aquatic Plant GrowthVascular Plants 46578939 Acceptable No



### 1. Rationales for Requesting Effects Studies

• Special Study for Non-Target Plant Repr oductive Toxicity (Non-Guideline) for TEP

Investigations/studies have indicated that a small percentage of the label application rate of low dose, high-potency herbicides such as ort hosulfamuron may impact the reproduction of nontarget terrestrial plants. However, there are no available data on adverse reproductive impacts to terrestrial plants from orthosul famuron residues due to spray drif t. Terrestrial plant reproductive toxicity data would help to screen for potential plan t risks. Plants form the basis of most habitats and contribute significantly to overall enviro nmental quality. The loss of plant reproductive output could potentially have an adverse effect on animals, both invertebra tes and vertebrates, as many are dependent on plant reprod uction as a food source and for habitat quality and structure. A solid understanding of the potential risks to plants is therefore essential. Thus, a special study for non-target plant reproductive toxicity (non-guideline) with the TEP is required.

Terrestrial plant reproductive toxic ity data would help to screen for potential plant risks. Plants form the basis of most habitats and contribute significantly to overall environmental quality. The loss of plant reproductive output could potentially have an adverse effect on animals, both invertebrates and vertebra tes, as many are dependent on plan t reproduction as a food source and for habitat quality and structure. A solid understandi ng of the potential risks to plants is therefore essential. A special study for non- target plant reproductive toxicity (non-guideline) is needed to reduce this uncertainty.

• Freshwater Fish-Acute Toxi city (850.1075) with the TEP

It is stated in 40 CFR Part 158.630 that studies with the TEP s hould be conducted on all aquatic animals (as evidenced from the TGAI data) for a particular taxon ( e.g., freshwater fish, freshwater invertebrates and estuarine/marine organisms). Thus, an acute toxicity study in freshwater fish is required for any end-use pro duct which will be introdu ced directly into an aquatic environment. Orthosulfamuron will be app lied to rice paddies that may be flooded with freshwater; therefore, this study is required. While orthosulfamuron is not expected to result in direct effects to fish, there is significant uncertainty regarding th e toxicity of the TEP to aquatic organisms. This study is requested in order to understand the toxicity of the end-use product as a whole, which may have very differe nt toxicity proprerties as compar ed to orthosulfamuron alone. When a product is applied directly to water a quatic organisms will be exposed to the entire

### 56 product. It is not known whether toxicity data on the parent alone will refl ect the toxicity of the entire product; therefore, the risk estimated for the parent alone does not inform whether data on the product are needed when a prod uct is applied directly to water. Therefore, data on the TEP are requested for freshwater fish. Data will be used to address the uncertainty regarding the potential enhanced toxic ity of the TEP. If the data show th at the TEP is more toxic than the TGAI, TEP toxicity data woul d be used to evaluate acute risk to fish exposed to orthosulfamuron.

• Freshwater Invertebrates-Acute Toxicity (850.1010) with the TEP

It is stated in 40 CFR Part 158.630 that studies with the TEP s hould be conducted on all aquatic animals (as evidenced from the TGAI data) for a particular taxon ( e.g., freshwater fish, freshwater invertebrates and estuarine/marine organisms). Thus, an acute toxicity study in freshwater invertebrates is required for any end- use product which will be introduced directly into an aquatic environment. Orthosulfamuron will be applied to rice paddies that may be flooded with freshwater; th erefore, this study is required. While orthosul famuron is not expected to result in direct effects to aquatic invertebra tes, there is significant uncertainty regarding the toxicity of the TEP to aquati c organisms. Therefore, data on the TEP are requested for freshwater invertebrates. Data will be used to address the uncertainty regarding the potential enhanced toxicity of the TEP. If the data show that the TEP is more toxic than the TGAI, TEP toxicity data would be used to evaluate acute risk to fresh water invertebrates exposed to orthosulfamuron.

• Terrestrial Plant Toxicity-Tie r 2 Vegetative Vigor (850.4150)

A terrestrial plant vegetative vi gor study was submitted for orthosulfamuron but was classified as supplemental due to a lack of definitive NOAEC in the most sensitive species, carrot and radish. Also, for soybean and pea height and mung bean dry weight, the EC 25 

### was lower than the lowest treatment level (<0.0017 lb a.i./A) and could not be determined. Therefore, this study is required.

2. Rationales for Not Requesting Effects Studies

• Avian Acute Oral Toxicity Test with a Passerine Species (850.2100)

According to the 40 CFR 158, acute oral toxicity data are required for a passerine species. Because no acute oral toxicity data have be en submitted for a passerine species exposed to orthosulfamuron, this is a data gap. No acute oral toxicity data involvin g orthosulfamuron or its degradates have been identified in the scientific literature (using ECOTOX).

Available acute oral toxicity data fo r birds (MRID 46260107 and 46219040) indicate that orthosulfamuron is classified as slightly toxic or practically nontoxic to the mallard duck and the bobwhite quail on an acute oral exposure basis. In addition, in a sub-acute toxicity study (MRID 46219040) with the mallard duck, no mortalities were observed at the highest test levels ( i.e., 4790 mg a.i./kg-food). In additi on, no sublethal effects were observed in these studies.

Given the low application rate of orthosulfamuron ( i.e., 0.067 lb a.i./A), it is expected that the

### 57 exposure of birds to orthosulfamuron will be low (dose-based EEC for birds is 18.31 mg/kg/day based on T-REX version 4.1.1). The lowest acute values for birds are 1960 mg a.i./kg-bw (highest dose tested) for acute oral and 4790 mg a. i./kg-diet (highest dose tested) for subacute dietary; the corresponding NOAEC values for thes e studies are both 1280 mg a.i./kg-diet (no mortality or frank toxicity was observed). As the acute oral toxicity values are based on body weight, the NOAEL value for the av ian acute oral was entered into T-REX to obtain the adjusted toxicity value for the small weight bird assessed in T-REX. The adjusted acute toxicity value for birds (20-g) is 1412 mg a.i./kg-bw. The acute toxi city value for birds is at least 75 times the EEC. 26 

### In order for orthosulfamuron to pose an acute risk to birds, passerines would have to be at least 11 to 33 times more sensitive to orthos ulfamuron as compared to mallard ducks and bobwhite quail. Given the pattern of acute toxicity of orthosulfamuron to aquatic and terrestrial vertebrates, the weight of evidence suggests th at orthosulfamuron will be relatively nontoxic to passerine species as well.

No ecological incidents involving bi rds exposed to orthosulfamuron or its degradates have been identified.

Therefore, EFED is not requesting oral toxicity data for passerines exposed to orthosulfamuron or its degradates.

• Saltwater Fish-Acute Toxici ty (850.1075) with the TEP

• Saltwater Invertebrates-Acute T oxicity (850.1025, 850.1035) with the TEP

According to the 40 CFR Part 158.630, acute aquatic toxicity data are required for freshwater and saltwater organisms examining exposure to th e TEP when a product may be applied directly to water, the EEC in the aquatic environment is ≥ one-half the LC 50 

### or EC 50 

### of the Technical Grade Active Ingredient (TGAI) when the end product is used as dire cted, or an ingredient in the end-use product other than the activ e ingredient is expected to enhance the toxicity of the active ingredient. Orthosulfamuron will be applied to rice paddies that will typically be flooded with freshwater. As orthosulfamuron is not expected to result in direct effects to aquatic organisms, data on orthosulfamuron TEP for freshwater organi sms is requested at this time, and data on marine/estuarine fish and invertebrates will be requested if further data are needed.

• Whole sediment survival, growth, a nd reproduction tests with TGAI and Chironomus

tentans , Leptocheirus plumulosus , and Hyalella azteca

According to 40 CFR Part 158.630, chronic sediment t oxicity data are required when the half-life of pesticide in sediment greater 10 days and 1) the Kd is ≥ 50 L/kg, 2) the K OC 

### ≥ 1000 L/kg, or the
K OW 

### ≥ 1000. One out of ten measured K OC 

### values was 2145 L/kg-oc and the half-live in sediment is greater than 10 days , indicating that whole chronic se diment toxicity data may be needed. The outlying K OC 

### was measured in a soil collected in Arkansas that had a pH of 5.66 and a low organic carbon content of 0.35%. While the measured value may occur near or in an intended use site as rice is commonly grown in Ar kansas, most rice paddies are expected to have a much higher organic matter content. Additionall y, aquatic invertebrate t oxicity data indicate

26 For the lowest ratio for acute terrestrial anim als (acute avian oral): 1412 ÷ 18.86 = 74.87

### 58 that exposure is highly unlikely to be high enoug h to result in a risk co ncern. Therefore, whole chronic sediment toxicity data are not requested at this time. This may be reevaluated in the future if exposure estimates or toxicity data indi cate that residues in se diment could result in a risk concern.

3. Degradate Toxicity Data

As discussed in Section XI Id entification of Stre ssors of Concern, da ta on DOP urea was identified to be needed in order to conduct the risk assessment as expos ure to ureas could alter the risk conclusions from those evaluated for the parent alone. The following studies are needed to assess risk due to exposure to DOP urea and o-desmethyl DOP urea.

• Freshwater Invertebrates- Acute Toxicity (OPPTS Guid eline 850.1010) with DOP urea Aquatic Invertebrate Life Cycle (Fresh water) (OPPTS Guide line 850.1300) with DOP

urea

• Fish Early Life Stage (Freshwater) (OPPTS Guideline 850.1400) with DOP urea

• Tier I and/or II Aquatic Plant Growth (OPPTS Guideline 850.4400) with nonvascular plants and DOP urea

Table 10 summarizes the effects data requirements for orthosulfamuron degradates. A brief rational for each data requirement is provided belo w. A more detailed discussion is available in Section XI; Identification of Stressors of Concern.

Table 10. Summary of Submitted Ecologica l Effects Studies and Data Gaps for Orthosulfamuron Degradates

OPPTS Guideline MRID Study Classification Data Gap? Comments for Data Gap

Aquatic Animals

850.1010 Freshwater Invertebrate – Acute Toxicity No Data NA Yes Data on DOP urea are needed to assess potentialrisk due to exposure to DOP urea and odesmethyl DOP urea. See Section XI for a full discussion. 850.1300 Freshwater Invertebrates-Life Cycle Test No data NA Yes

850.1400 Freshwater Fish-Early Life Stage Test No data NA Yes

Plants

850.4150 Terrestrial Plant Toxicity-Tier I and/or II Vegetative Vigor No data NA Yes Data on DOP urea are needed to assess potentialrisk due to exposure to DOP urea and odesmethyl DOP urea. See Section XI for a full discussion. A Tier I data may be sufficient to fulfill this guideline if less than 50% effects are observed at the highest EEC.

### 59 OPPTS Guideline MRID Study Classification Data Gap? Comments for Data Gap

850.4400 Aquatic Plant Growth- No data NA Yes Data on DOP urea are needed to assess potentialrisk due to exposure to DOP urea and odesmethyl DOP urea. See Section XI for a full discussion.



### • Tier I and/or II Aquatic Plant Growth (OPPTS Guideline 850.4400) with nonvascular plants and DOP urea

Concentrations of urea residues considering ma ximum amounts of DOP urea, o-desmethyl DOP urea, and unextracted were estimated to range from 10-15 μg/L ( Appendix F ). Measured nonvascular plant Aquatic Life Benchmarks for ur eas range from 2.4 to 80 μg/L. This indicates that degradate concentrations have the potential to be present at high enough to cause a risk concern for non-vascular aquatic plan ts. Tier I data may be suffici ent to fulfill this guideline if less than 50% effects are observed at the highest EECs. Therefore, data will be requested on DOP urea for nonvascular aquatic pl ants. To estimate risk due to exposure to the ureas for aquatic organisms, an EEC will be estimated considering exposure to both DOP urea and odesmethyl DOP urea and the EEC will be compared to effects data for DOP urea.

• Freshwater Invertebrates-Acute Toxicity (OPPTS Guideline 850.1010) with DOP urea

• Aquatic Invertebrate Life Cycle (Fresh water) (OPPTS Guide line 850.1300) with DOP

urea

• Fish Early Life Stage (Freshwater) (OPPTS Guideline 850.1400) with DOP urea

Chronic ALBs 27 

### for some urea herbicides (range fro m 0.09 to 21,800 μg/L) are much lower than those for orthosulfuramuron (range from 6,100 to 6,500 μg/L) ( Appendix B ). 28 

### EECs for ureas ranged from 10 to 15 μg/L. Acut e ALBs for some urea herbicides for freshwater invertebrates indicate there is a pote ntial for concentrations to be high enough to result in a risk concern. Therefore, chronic toxicity data for DOP urea are needed for aqua tic animals and acute toxicity data for freshwater invertebrate are needed.

4. Testing on Typical end-use products (TEP)

A Typical End-Use Product is defined in the Pesticide Assessment Guidelines Subdivision J Hazard Evaluation: Nontarget plants on Part 120-2(1) on Page 18 as “a pesticide product that is representative of a majo r formulation category ( e.g ., emulsifiable concentr ate, granular product, wettable powder) and pesticide group ( e.g ., herbicide, fungicide, insecticide etc .) and contains

27 Benchmarks, developed for baseline risk assessments, are estimates of the concentrations below which pesticides are not expected to harm aquatic life. Each Aquatic Life Benchmark is based on the most sensitive, scientifically acceptable toxicity endpoint available to EPA for a given taxon (for example, freshwater fish) of all scientifically acceptable toxicity data available to EPA multiplied by the co rresponding level of concern of 0.5 for acute endpoints and 1.0 for chronic and plant endpoints. Aquatic life benchmarks may be found at http://www.epa.gov/oppefed1/ecorisk_ders/aquatic_life_benchmark.htm

. 28 Three of six chronic values ranged from 0.09 – 26 μg/L and were in the range of EECs estimated for ureas of 10 to 15 μg/L.

### 60 the active ingredient of the applicant’ s product.” (Holst and Ellwanger, 1982)

Page 5 of the Pesticide Assessment Guidelines Subdivisi on J Hazard Evaluation: Nontarget plants provides additional information on what TEP data should be tested for toxicity testing in the following excerpt.

“The Agency seeks to avoid imposing a burde n of duplicative testing on applicants for registration. Therefore, where 40 CFR Part 158 specifies that the test substance should be a representative end-use pr oduct, testing may be performed usi ng the formulation in question (enduse product being registered ) or similar, yet representative, end- use product. It is not necessary to repeat the test using other simila r products.” (Holst and Ellwanger, 1982)

When TEP data are requested data should be submitted for the different formulations, e.g ., wettable powder, emulsifiable conc entrate, granular, along with a ra tionale as to why the TEP is representative of other similar end-use products.



# XV. Other Information Needs

There is specific information that will assist the Agency in refini ng the ecological risk assessment, including any species-specific effect s determinations. The Agency is very much interested in obtaining the following information: 1. confirmation on the following label information

a. frequency of application, applicati on intervals, and maximum number of applications per season b. geographic limitations on use 2. use or potential use distribution ( e.g ., acreage and geographical distribution of relevant crops) 3. use history 4. median and 90 th 

### percentile reported use rates (lbs. a. i./acre) from usage data – national, state, and county
5. application timing (date of first application and application interval s) by crop – national, state, and county 6. sub-county crop location data
7. directly acquired county-level usage da ta (not derived from state level data)

a. maximum reported use rate (lbs. a.i. /acre) from usage data – county b. percent crop treated – county

c. median and 90 th 

### percentile number of applications – county d. total pounds per year – county

e. the year the pesticide was last us ed in the county/sub-county area f. the years in which the pesticide was applied in the county/sub-county area 8. state or local use restrictions 9. ecological incidents (non-target plant damage and avian, fish, reptilian, amphibian and mammalian mortalities) not alr eady reported to the Agency 10. monitoring data

In order to assess the risk to terrestrial organisms exposed to gr anules the weight of one granule

### 61 for each granule formulation would be useful.



# XV. References

Armitage, J. M., & Gobas, F. A. P. C. 2007. A terrestrial food-chain bioaccumulation model for POPs. Environmental Science and Technology, 41 , 4019-4025. Asghari, J. B., & Evans, J. O. 1992a. Dyer’s woad (Isatis tinctoris L.) po llen viability is reduced by metsulfuron methyl application. Research Progress Report on the Western Society of Weed Science. Meeting Ma rch 9-12. Salt Lake City Utah , 178-179. Asghari, J. B., & Evans, J. O. 1992b. Effect of metsulfuron methyl on seed formation and viability of Dyer’s woad ( Isatis tinctoria L. ) in the field. Research Progress Report of the Western Society of Weed Science. Meeting March 9-12, 1992. Salt Lake City, UT, III178-II-179. Bhatti, M. A., Al-Khatib, K., Felsot, A. S., Park er, R., & Kadir, S. 1995. Effects of simulated chlorsulfuron drift on fruit yield and quality of sweet cherries ( Prunus avium L. ). Environmental Toxicology and Chemistry, 14 (3), 537-544. Boutin, C., Lee, H. B., Peart, E. T., Batchelor, P. P., & Maguire, R. J. 2000. ffects of the sulfonylurea herbicide metsulfuron methyl on growth and reproduction of five wetland and terrestrial plant species. Environmental Toxicology and Chemistry, 19 (10), 2532- 2541. Fletcher, J. S., Nellessen, J. E., & Pfleeger, T. G. 1994. Literature review and evaluation of the EPA food-chain (Kenaga) nomogram, an instru ment for estimating pesticide residues on plants. Environmental Toxicology and Chemistry, 13 (9), 1383-1391. Fletcher, J. S., Pfleeger, T. G., & Ratsch, H. C. 1993. Potential environm ental risks associated with the new sulfonylurea herbicides. Environmental Science and Technology, 27 (10), 2250-2252. Fletcher, J. S., Pfleeger, T. G., Ratsch, H. C ., & Hayes, R. 1996a. Chlorsulfuron influence on garden pea reproduction. Physiologia Plantarum, 94 , 261-267. Fletcher, J. S., Pfleeger, T. G., Ratsch, H. C., & Hayes, R. 1996b. Potential impact of low levels of chlorsulfuron and other herbicides on growth and yield of nontarget plants. Environmental Toxicology and Chemistry, 7 , 1189-1196. Hoerger, F., & Kenaga, E. E. 1972. Pesticide Resi dues on Plants: Correlation of Representative Data as a Basis for Estimation of their Magni tude in the Environment. In F. Coulston & F. Korte (Eds.), Environmental Quality and Safety : Chemistry, Toxicology, and Technology (Vol. 1, pp. 9-28). New York: Academic Press. ISAGRO. Orthosulfamuron Technical Bulletin . Memorandum From to Available at http://www.isagro.com/images/stories/file /PDF/Orthosulfamuron%20Technical%20Bulle tin%20may2010.pdf (Accessed June 20, 2011). NCI/CADD Group. 2011. Online SMILES Translator and Structure File Generator : National Cancer Institute. National In stitute of Health. Center for Cancer Research. Available at http://cactus.nci .nih.gov/translate/ Pfleeger, T., Olszyk, D., Lee, E. H., & Plocher, M. 2011. Comparing effects of low levels of herbicides on greenhouse- and field-grown potatoes ( Solanum tuberosum L .), soybeans ( Glycine max L. ), and peas ( Pisum sativum L. ). Environmental Toxicology and Chemistry, 30 (2), 455-468.

### 62 Teske, M. E., & Curbishley, T. B. 2003. AGDISP Version 8.07 User Manual . Prepared For United States Department of Agriculture Fore st Service. C.D.I. Technical Note No. 02- 06. June 2003. USEPA. 1993. Wildlife Exposure Handbook

, United States Environmental Progection Agency

. Washington, D.C.: Government Printing Office. Available at http://www.epa.gov/ncea/pdfs/toc2-37.pdf (Accessed June 19, 2009). USEPA. 1998. Guidelines for Ecological Risk Assessment . EPA/630/R-95/002F. United States Environmental Protection Agency (USEPA). Risk Assessment Forum. Office of Research and Development. Available at http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=12460 (Accessed June 19, 2009). USEPA. 2004. Overview of the Ecological Risk Assessm ent Process in the Office of Pesticide Programs . United States Environmental Protec tion Agency (USEPA). Environmental Fate and Effects Division. Office of Pesticide Programs. Available at http://www.epa.gov/espp/consultation/ecorisk-overview.pdf (Accessed June 19, 2009). USEPA. 2006.D333514. Environmental Fate and Ecological Risk Assessment for the Registration of Orthosulfamuron . D333514. December 28, 2006. Environmental Fate and Effects Division, Office of Pesticide Program s, United States Environmental Protection Agency. USEPA. 2006.330828. Orthosulfamuron (Section 3: Rice Us e) Tier I Drinking Water Exposure Assessment for Orthosulfamuron on Rice . 330828. Memorandum From G. Orrick to J. Tompkins & K. Bailey. Environmental Fate and Effects Division. Office of Prevention, Pesticides, and Toxic Substances. United St ates Environmental Pr otection Agency. USEPA. 2007a. Ecological Inci dent Information System. United States Environmental Protection Agency. Available at http://www.epa.gov/espp/consultation/ecoriskoverview.pdf (Accessed June 19, 2009). USEPA. 2007b. Guidance for Tier I Estimation of Aque ous Pesticide Concentrations in Rice Paddies . Memorandum From S. Bradbury to E. F. a. E. Division. Environmental Fate and Effects Division. Office of Pesticide Programs. United States Environmental Protectin Agency. Available at http://www.epa.gov/oppefed1/m odels/water/rice_tier_i.pdf (Accessed July 5, 2011). USEPA. 2007.D319264. Orthosulfamuron: Human Health Risk Assessment for Proposed Use on Rice. PC Code: 108209, Petition No: 5F6957, DP Barcode D319264 . Memorandum From K. J. Bailey, D. Dotson & Z. Figueroa to E. Kraft. Health Effects Division. Office of Prevention, Pesticides, and Toxic Substances. United Stat es Environmental Protection Agency. USEPA. 2008a. Environmental Fate and Ecological Risk Assessment for Etofenprox New Uses on Rice and for Vector Control

, United States Environmental Protection Agency

. Washington, D.C. USEPA. 2008b. White paper on Methods for Assessing Ecol ogical Risks of Pesticides with Persistent, Bioaccumulative, and Toxic Characteristics . Submitted to the FIFRA Scientific Advisory Panel for Review and Comment. October 7, 2008. Environmental Fate and Effects Division. Office of Pe sticide Programs. Office of Prevention, Pesticides, and Toxic Substances. Available at http://www.epa.gov/scipoly/SAP/meetings/ 2008/october/sap_pbt_whitepaper_final_Oct_ 7_08d.pdf (Accessed January 27, 2010).

### 63 USEPA. 2009a. ECOTOXicology Database

, United States Environmental Protection Agency (USEPA) . Available at http://cfpub.epa.gov/ecotox/ (Accessed June 19, 2009). USEPA. 2009b. SAP Minutes No. 2009-01. A set of Scienti fic Issues Being Considered by the Environmental Protection Agency Regarding: Se lected Issues Associated with the Risk Assessment Process for Pesticides with Persistent, Bioaccumulative, and Toxic Characteristics. October 28-31, 2008. January 29, 2009. FIFRA Scientific Advisory Panel. Office of Science Coordi nation and Policy. Available at http://www.epa.gov/scipoly/sa p/meetings/2008/102808_mtg.htm (Accessed July 9, 2009). USEPA. 2010a. BEAD Chemical Profile for Registrati on Review: Orthosulfamuron (108209)

. Memorandum From S. Ratnayake, S. Haddad & S. Smearman to J. Parker. May 18, 2010. Biological and Economic Analysis Division, Office of Chemical Safety and Pollution Prevention. United States Environmental Protection Agency USEPA. 2010b. Guidance for Reporting on the Environm ental Fate and Transport of the Stressors of Concern in the Problem Formul ation for Registration Review, Registration Review Risk Assessments, Listed Species Litigation Assessments, New Chemical Risk Assessments, and Other Relevant Risk Assessments . January 25, 2010. Environmental Fate and Effects Division, . USFWS/NMFS. 1998. Endangered Species Consultation Handbook: Procedures for Conducting Consultation and Conference Activities Under Section 7 of the Endangered Species Act. Final Draft . United States Fish and Wildlife Se rvice (USFWS) and National Marine Fisheries Service (NMFS). Available at http://www.fws.gov/endangered/ consultations/s7hndbk/s7hndbk.htm (Accessed June 19, 2009). USNLM. 2009. TOXNET Toxicology Data Ne twork. United States National Library of Medicine (USNLM). Available at http://toxnet.nlm.nih.gov/ (Accessed July 9, 2009). Ware, G. W., & Whitacre, D. M. 2004. An Introduc tion to Herbicides. In E. B. Radcliffe & W. D. Hutchison (Eds.), The Pesticide Book (6th ed.). Willoughby, OH: MeisterPro Information Resources. Available at http://ipmworld.umn.edu/chapters/whitacreherb.htm (Accessed June 19, 2009). Wood, A. 2009. Compendium of Pestic ide Common Names. Available at http://www.alanwood.ne t/pesticides/index.html (Accessed June 19, 2009).

Data Submitted To Support Registration

Hydrolysis OPPTS 835.2120 46578970 Faltynski, K. (2005) Determination of Aquatic Dissolution Rate of IR5878GR and pH 5 Hydrolysis Rate of IR5878 Standar d. Project Number: 04/0041, FR/00292. Unpublished study prepared by En-Cas Analyti cal Laboratories, Agvise Inc a nd Isagro Ricerca Galliera. 67

p.

46219015 Castoldi, F.; Pizzingrilli, G. (2000) Hydrolysis of ((Car bon 14)-U-phenyl) IR5878 in Buffered Solutions at pH 4, 7 and 9. Project Number: ABT/99/13. Unpublished study prepared by Isagro S.R.L. (Formerly Agrimont). 120 p.

### 64 46219016 Castoldi, F.; Pizzingrilli, G. (2000) Identification of Hydrolysis Compounds of ((Carbon 14)-5-pyrimidinyl) IR5878 at pH 4, 7 and 9. Project Number: ABT/00/16. Unpublished study prepared by Isagro S.R.L. (Formerly Agrimont). 100 p.

Aqueous Photolysis OPPTS 835.2370 46588509 Hennecke, D. (2002) Aquatic Photodeg radation and Quantum Yield of IR5878: Final Report. Project Number: ISA/003/ 7/05, WD00612/000. Unpublished study prepared by Fraunhofer Institute for Molecular Biology and Applied Ecology. 50 p.

Aerobic Aquatic Me tabolism OPPTS 835.4300 46219017 Scacchi, A.; Vanini, L.; Pizzingrilli, G. (2003) Aerobic Aquatic Metabolism of (Carbon 14)-IR5878 in Two American Soils. Pr oject Number: MEF/02/14. Unpublished study prepared by Isagro S.R.L. (Formerly Agrimont). 298 p.

46588508 Scacchi, A.; Vanini, L.; Oriolo, D. (2005) Aerobic Aquatic Degradation of (Carbon14)-IR5878 in Paddy-Field Soil Under Sunlight . Project Number: MEF/04/13, WD00612/000. Unpublished study prepared by Isagro Ricerca S.r.l. 198 p.

Anaerobic Aquatic Metabolism OPPTS 835.4400 46578967 Scacchi, A.; Soddu, R.; Pizzingrilli, G. ( 2003) Anaerobic Aquatic Metabolism of (Carbon-14)-IR5878 in Two American Soils. Project Number: MEF/02/16, A2/07/01/10. Unpublished study prepared by Isagro S.R.L. (F ormerly Agrimont) and Theolab s.r.l. and Agenzia Regionale Prevenzione e Ambiente dell'Emilia-Romagna. 280 p.

Batch Equilibrium Study OPPTS 835.1240 46219074 Scacchi, A.; Pizzingrilli, G. (2000) Adsorption-desorption of (Carbon 14)-IR5878 in Soil. Project Number: ABT/00/04. Unpublished study prepared by Isagro S.R.L. (Formerly Agrimont). 129 p.

46578971 Scacchi, A.; Trucco, M. (2005) Adsorption/Desorption of (Carbon-14)-IR5878 in American Soils. Project Number: MEF/04/ 02, A2/07/01/20. Unpublished study prepared by Isagro S.R.L. (Formerly Agrimont). 210 p.

Soil Column Leaching 46219018 Scacchi, A.; Pizzingrilli, G. (2003) Aged Residue Column Leaching at (Carbon 14)- IR5878 in an American Soil. Project Numb er: MEF/02/17. Unpublished study prepared by Isagro S.R.L. (Formerly Agrimont). 194 p

46578968 Scacchi, A.; Vanini, L.; Pizzingrilli, G. (2004) Soil Column Leaching of (Carbon14)-IR5878. Project Number: MEF/03/17, A2/07/01/17. Unpublished study prepared by Isagro S.R.L. (Formerly Agrimont). 162 p.

Aquatic Field Dissipation OPPTS Guideline 835.6200 46578985 Cooley, T. (2005) IR5878 Field Dissipation Study in Bare Ground Rice Soil: Final Study Report. Project Number: ERS23044, 1204W , A3/03/00/01. Unpublished study prepared by Excel Research Services, Inc., PTRL West , Inc. and Shoffner Farm Research. 1014 p.

### 65 Bioconcentration Factor OPPTS Guideline 850.1730 46588507 Dijk, A. (2004) Bioconcentration: Flow-T hrough Fish Test with IR5878 in Bluegill Sunfish (Lepomis macrochirus). Proj ect Number: 849257, WD00612/000. Unpublished study prepared by RCC Umweltchemie Ag. 68 p.

Storage Stability Studies 46578977 Zini, G.; Crisippi, T. (2004) Storage Stability of IR7863 in Soil and Sediment Stored in the Dark Below -20 Degrees Celsius. Project Number: 2405, A2/06/00/07. Unpublished study prepared by Isagro S.R.L. (F ormerly Agrimont) and Agvise Inc. 138 p.

46578978 Zini, G.; Crisippi, T. (2004) Storage St ability of IR7863 in Surface Water Stored in the Dark Below -20 Degrees Celsius. Project Number: 2403, A2/06/00/06, SPL/1700/048. Unpublished study prepared by Isagro S.R.L. (Formerly Agrimont) and Theolab. 94 p.

46578979 Zini, G.; Crisippi, T. (2004) Storage St ability of IR7825 in Surface Water Stored in the Dark Below -20 Degrees Celsius. Project Number: 2402, A2/06/00/05, SPL/1700/024. Unpublished study prepared by Isagro S.R.L. (Formerly Agrimont) and Theolab. 105 p.

46578980 Zini, G.; Crisippi, T. (2004) Storage Stability of IR7825 in Soil and Sediment Stored in the Dark Below -20 Degrees Celsius. Project Number: 2404, A2/06/00/04, SPL/1700/24. Unpublished study prepared by Isagro S.R.L. (Formerly Agrimont) and Agvise Inc. and Agenzia Regionale Pevenzione e Ambiente dell'Emilia-Romagne. 131 p.

46578981 Zini, G.; Crisippi, T. (2004) Storage Stability of IR5878 in Soil, Sediment and Surface Water Stored in the Dark Below -20 Degrees Celsius. Project Number: 2377, A2/06/00/03. Unpublished study prep ared by Isagro S.R.L. (Formerly Agrimont) and Agvise Inc and Agenzia Regionale Pevenzione e Ambiente dell'Emilia-Romagne. 164 p.

Melting Point/Melting range OPPTS Guideline 830.7200 46219007 Evans, A.; Mullee, D. (2002) IR5878 (Technical): Determination of Melting/Freezing Temperature. Project Number: 1700/009. Unpublished study prepared by Safepharm Laboratories, Ltd. 14 p.

Partition Coefficient OPPTS Guideline 830.7570 46219012 Woolley, S.; Mullee, D. (2002) IR 5 878 (Pure): Determination of Partition Coefficient. Project Number: 1700/023. Unpublished study prepared by Safepharm Laboratories, Ltd. 25 p.

Water Solubility OPPTS Guideline 830.7840 46219009 Woolley, S.; Mullee, D. (2002) IR 5878 (P ure): Determination of Water Solubility. Project Number: 1700/005. Unpub lished study prepared by Safepharm Laboratories, Ltd. 25 p.

Vapor Pressure OPPTs Guideline 830.7950 46219010 Tremain, S. (2002) IR 5878 (Pure): Dete rmination of Vapour Pressure. Project Number: 1700/007. Unpublished study prepared by Safepharm Laboratories, Ltd. 19 p.

### 66 Non-guideline Studies 46219011 Woolley, S.; Mullee, D. (2002) IR 5878 (Pure): Determination of Dissociation Constant. Project Number: 1700/006. Unpublishe d study prepared by Safepharm Laboratories, Ltd. 7 p.

46219021 Dotti, A. (2000) IR5878: 4-Hour Acute Inha lation Toxicity Study in the Rat. Project Number: R06390. Unpublished study prepared by Istituto Di Recerche Biomediche (RBM) "Antoine Marxer". 50 p.

46559001 Woolley, S.; Mullee, D. (2002) IR 5878 (P ure): Determination of Spectra. Project Number: 1700/004, WD00612/000. Unpublished study pr epared by Safepharm Laboratories Ltd. 33 p.

Avian Single Dose Oral Toxicity 46260107 Dias, N. (2001) IR5878: Acut e Oral Toxicity (LD50) to the Mallard Duck. Project Number: IGA/003/012865. Unpublished st udy prepared by Huntingdon Life Sciences, Ltd. 38 p. 46260108 Dias, N. (2001) IR5878: Acute Oral Toxicity (LD50) to th e Bobwhite Quail. Project Number: IGA/004/012894. Unpublished st udy prepared by Huntingdon Life Sciences, Ltd. 43 p. Avian Dietary Toxicity
46219040 Dias, N. (2001) IR 5878: Dietary Toxicity (LC50) to the Mallard Duck. Project Number: IGA/005, IGA/005/012373. Unpublis hed study prepared by Huntingdon Life Sciences, Ltd. 35 p. 46219041 Rodgers, M. (2001) IR 5878: Dietary Toxi city (LC50) to the Bobwhite Quail. Project Number: IGA/002, IGA/002/ 012368. Unpublished study prepared by Huntingdon Life Sciences, Ltd. 41 p. Avian Reproduction 46578949 Frey, L.; Martin, K.; Beavers, J.; et. al. (2003) IR-5878: A Reproduction Study with the Mallard: Final Report. Project Nu mber: 544/109. Unpublished study prepared by Wildlife International, Ltd. 157 p. 46578950 Frey, L.; Martin, K.; Beavers, J.; et al. (2003) IR5878: A Reproduction Study with the Northern Bobwhite: Fi nal Report. Project Number: 544/108. Unpublished study prepared by Wildlife International, Ltd. 164 p.

2-generation repro.-rat 46219033 Marburger, A. (2003) IR5878: Two-Gene ration Reproduction Toxi city Study in the Rat. Project Number: 841291. Unpublished study prepared by RCC Umweltchemie Ag and RCC Ltd. 1170 p. 46260106 Marburger, A.; Knuppe, C.; Nehrbass, D. (2002) IR5878: Preliminary Reproduction Toxicity Study in the Rat. Proj ect Number: 841176, 80012/NED. Unpublished study prepared by Isagro S.P.A. 276 p. 850.1010 Aquatic invertebrate ac ute toxicity, test, freshwater daphnids

### 67 46219044 Hertl, J. (2000) Final Report: Acute T oxicity of IR5878 to Daphnia magna in a 48- hour Immobilization Test. Project Nu mber: 8222220. Unpublished study prepared by Institut fuer Biologische Anal ytik und Consulting IBACON GmbH. 24 p.

46219045 Meinerling, M. (2000) Final Analytical Report: Acute Toxicity of IR5878 to Daphnia magna in a 48-Hour Immobilization Test: (Final Report). Project Number: 8222220A. Unpublished study prepared by Institut fuer Biologische Analytik. 18 p.

850.1025 Oyster acute toxici ty test (shell deposition) 46578957 Palmer, S.; Kendall, T.; Krueger, H. (2004) IR5878: A 96-Hour Shell Deposition Test with the Eastern Oyster (Crassostrea virginica): Final Report. Project Number: 544A/106. Unpublished study prepared by W ildlife International, Ltd. 40 p.

850.1035 Mysid acute toxicity test 46578952 Palmer, S.; Stence, M.; Kendall, T.; et. al. (2002) IR5878: A 96-Hour Static Acute Toxicity Test with the Saltwater Mysid (A mericamysis bahia): Final Report. Project Number: 544A/108. Unpublished study prepared by Wildlife International, Ltd. 37

p. 850.1075 Fish acute toxici ty test, freshwater and marine 46219042 Palmer, S.; Stence, M.; Kendall, T.; et. al. (2002) IR5878: A 96-Hour Static Acute Toxicity Test with the Rainbow Trout (Oncorhynchus mykiss): Final Report. Project Number: 544A/107. Unpublished study prepared by Wildlife International, Ltd. 38 p. 46219043 Palmer, S.; Kendall, T.; Krueger, H. (2003) IR5878: A 96-Hour Static Acute Toxicity Test with the Bluegill (Lepom is macrochirus): Final Report. Project Number: 544A/111. Unpublished study prepared by Wildlife International, Ltd. 38

p. 46578951 Palmer, S.; Kendall, T.; Krueger, H. (2002) IR5878: A 96-Hour Statice Acute Toxicity Test with the Sheepshead Mi nnow (Cyprinodon varigatus): Final Report. Project Number: 544A/109. Unpublished study prepared by Wildlife International, Ltd. 37 p. 46578955 Sutherland, C.; Kendall, T.; Krueger, H. (2003) IR5878: A 96-Hour Static Acute Toxicity Test with the Crayfish (Proca mbarus clarkii): Final Report. Project Number: 544A/124. Unpublished study prepared by Wildlife International, Ltd. 49

p. 850.1300 Daphnid chronic toxicity test 46578956 Palmer, S.; Thomas, S.; Kendall, T.; et al. (2003) IR5878: A Semi-Static Life-Cycle Toxicity Test with the Cl adoceran (Daphnia magna): Fi nal Report. Project Number: 544A/123. Unpublished study prepared by W ildlife International, Ltd. 57 p.

850.1350 Mysid chronic toxicity test 46578954 Blankinship, A.; Kendall, T.; Krueger, H. (2003) IR5878: A Flow-Through LifeCycle Toxicity Test with the Saltwater Mysid (Mysidopsis bahia): Final Report. Project Number: 544A/112. Unpublished study prepared by Wildlife International, Ltd. 70 p. 850.1400 Fish early- life stage toxicity test

### 68 46578953 Palmer, S.; Kendall, T.; Krueger, H. (2003) IR5878: An Early Life-Stage Toxicity Test with the Fathead Minnow (Pimepha les promelas): Final Report. Project Number: 544A/110. Unpublished study prepared by Wildlife International, Ltd. 71

p. 850.1730 Fish BCF 46588507 Dijk, A. (2004) Bioconcentration: Flow-T hrough Fish Test with IR5878 in Bluegill Sunfish (Lepomis macrochirus) . Project Number: 849257, WD00612/000. Unpublished study prepared by RCC Umweltchemie Ag. 68 p.

850.3020 Honey bee acute contact toxicity 46219046 Schmitzer, S. (2003) Laboratory Testing for Toxicity (Acute Contact and Oral LD50) of IR5878 on Honey Bees (Apis mellifer a L.): Final Report. Project Number: 1, 8225036. Unpublished study prepared by Institut fuer Biologische Analytik und Consulting IBACON Gmbh. 41 p. 850.4100 Terrestrial plant to xicity, Tier 1 (seeding emergence)
46578941 Porch, J.; Krueger, H.; Martin, K. (2003) IR5878 50WG: A Toxicity Test to Determine the Effects on Seedling Emergence of Ten Species of Plants: Final Report. Project Number: 544/110. Unpub lished study prepared by Wildlife International, Ltd. 107 p. 46710802 Porch, J.; Krueger, H.; Krip, W. ( 2005) IR5878 50WG: A To xicity Test to Determine the Effects on Seedling Emerge nce of Tomato: Final Report. Project Number: 544/113. Unpublished study prepared by Wildlife Intern ational, Ltd. 39 p.

850.4150 Terrestrial plant toxicity, Tier 1 (vegetative vigor) 46578942 Porch, J.; Krueger, H. (2003) IR5878 50WG : A Toxicity Test to Determine the Effects on Vegetative Vigour of Ten Speci es of Plants: Fina l Report. Project Number: 544/111. Unpublished study prepared by Wildlife Inte rnational, Ltd. 146

p. 46710801 Porch, J.; Krip, W.; Krueger, H. (2005) IR5878WG: A Toxicity Test to Determine the Effects on Vegetative Vigour of Two Sp ecies of Plants: Final Report. Project Number: 544/114. Unpublished study prepared by Wildlife Intern ational, Ltd. 65 p.

850.4225 Seedling emergence, Tier II 46578941 Porch, J.; Krueger, H.; Martin, K. (2003) IR5878 50WG: A Toxicity Test to Determine the Effects on Seedling Emergence of Ten Species of Plants: Final Report. Project Number: 544/110. Unpub lished study prepared by Wildlife International, Ltd. 107 p. 46710802 Porch, J.; Krueger, H.; Krip, W. ( 2005) IR5878 50WG: A To xicity Test to Determine the Effects on Seedling Emerge nce of Tomato: Final Report. Project Number: 544/113. Unpublished study prepared by Wildlife Intern ational, Ltd. 39 p.

850.4250 Vegetative vigor, Tier II 46578942 Porch, J.; Krueger, H. (2003) IR5878 50WG : A Toxicity Test to Determine the Effects on Vegetative Vigour of Ten Speci es of Plants: Fina l Report. Project Number: 544/111. Unpublished study prepared by Wildlife Inte rnational, Ltd. 146

p.

### 69 46710801 Porch, J.; Krip, W.; Krueger, H. (2005) IR5878WG: A Toxicity Test to Determine the Effects on Vegetative Vigour of Two Sp ecies of Plants: Final Report. Project Number: 544/114. Unpublished study prepared by Wildlife Intern ational, Ltd. 65 p.

850.4400 Aquatic plant toxicity test using Lemna spp. Tiers I and II 46578939 Desjardins, D.; Kendall, T.; Krueger, H. (2003) IR5878 50WG Alone: A 7-Day Toxicity Test with Duckweed (Lemna gi bba G3): Final Report. Project Number: 544A/120. Unpublished study prepared by W ildlife International, Ltd. 44 p.

46578940 Desjardins, D.; Kendall, T.; Krueger, H. (2004) IR5878 50WG: A 7-Day Toxicity Test with Duckweed (Lemna gibba G3): Final Report. Project Number: 544A/114. Unpublished study prepared by Wildlife International, Ltd. 45 p.

850.5400 Algal toxicity, Tiers 1 and II
46578931 Desjardins, D.; Kendell, T.; Krueger, H. (2003) IR5878 50WG Alone: A 96-Hour Toxicity Test with the Freshwater Alga (Selejastrum capricornutum): Final Report. Project Number: 544A/121. Unpublished study prepared by Wildlife International, Ltd. 50 p. 46578932 Desjardins, D.; Kendall, T.; Krueger, H. (2003) IR5878 50WG Alone: A 96-Hour Toxicity Test with the Freshwater Diat om (Navicula pelliculosa): Final Report. Project Number: 544A/119. Unpublished study prepared by Wildlife International, Ltd. 50 p. 46578933 Desjardins, D.; Kendell, T.; Krueger, H. (2003) IR5878 50WG Alone: A 96-Hour Toxicity Test with the Marine Diatom (Skeletonema costatum). Project Number: 544A/122. Unpublished study prepared by W ildlife International, Ltd. 53 p.

46578934 Desjardins, D.; Kendell, T.; Krueger, H. (2003) IR5878 50WG: A 96-Hour Toxicity Test with the Freshwater Alga (Selenastr um capricornutum): Final Report. Project Number: 544A/116. Unpublished study prepared by Wildlife International, Ltd. 54

p. 46578935 Desjardins, D.; Kendall, T.; Krueger, H. (2003) IR5878 50WG: A 96-Hour Toxicity Test with the Freshwater Diatom (Navic ula pelliculosa): Final Report. Project Number: 544A/115. Unpublished study prepared by Wildlife International, Ltd. 53

p. 46578936 Desjardins, D.; Kendell, T.; Krueger, H. (2003) IR5878 50WG: A 96-Hour Toxicity Test with the Marine Diatom (Skelet onema costatum): Final Report. Project Number: 544A/117A. Unpublished study prepar ed by Wildlife International, Ltd. 53 p. 46578937 Desjardins, D.; Kendall, T.; Krueger, H. (2003) IR5878 50WG: A 96-Hour Toxicity Test with the Freshwater Alga (Anam aena flos-aquae): Final Report. Project Number: 544A/113. Unpublished study prepared by Wildlife International, Ltd. 51

p. 46578938 Desjardins, D.; Kendall, T.; Krueger, H. (2003) IR5878 50WG Alone: A 96-Hour Toxicity Test with the Freshwater Al ga (Anabaena flos-aquae): Final Report. Project Number: 544A/118. Unpublished study prepared by Wildlife International, Ltd. 55 p. 870.1100 Acute oral toxicity

### 70 46219019 Yu, P. (1999) Acute Oral Toxicity Study in Rats Treated with the Test Article IR5878. Project Number: 990496. Unpublished study prepared by Istituto Di Recerche Biomediche (RBM) "Antoine Marxer". 34 p. 46578918 Ott, M. (2003) IR7863: Ac ute Oral Toxicity Study in Rats. Project Number: A2/05/08/05, 850107. Unpublished study prepared by RCC Ltd. 20 p.
870.1300 Acute inhalation toxicity

46219066 Decker, U.; Knuppe, C.; Ullrich, A. (2003) IR5878 50WG Al one: 4-Hour Acute Inhalation Toxicity Study in Rats: Final Report. Project Number: 847655, 904994. Unpublished study prepared by RCC Ltd. 85 p. 46219067 Decker, U.; Knuppe, C.; Ullrich, A. ( 2003) IR5878 50WG: 4-Hour Acute Inhalation Toxicity Study in Rats: (Technical Tria ls Preceding a Proposed 4-Hour Acute Inhalation Toxicity Study in Rats): Final Report. Project Number: 847122. Unpublished study prepared by RCC Ltd. 37 p. 46578990 Decker, U.; Knuppe, C.; Ullrich, A. (2004) IR5878 0.5 GR: 4-Hour Acute Inhalation Toxicity Study in Rats: Final Report. Project Number: 849646, A3/07/01/20. Unpublished study prepar ed by RCC Umweltchemie Ag. 86 p.

870.4300 Combined chroni c toxicity/carcinogenicity 46578913 Webley, L. (2004) IR5878: Combined Ca rcinogenicity and Toxicity Study By Dietary Administration to Han Wistar Rats for 104 Weeks. Project Number: A2/05/05/02, AGR/131/033063, AGR/131. U npublished study prepared by Huntingdon Life Sciences, Ltd. 2241 p.

### 71 Appendix A. Supplemental Enviro nmental Fate Information

Table A1. Summary of other environmen tal fate and transport properties of orthosulfamuron.

Parameter Value(s) and Units Source (Study Classification) Comments

Hydrolysis 6 Half-life, linear regression 1 : pH 7 at 25 o C: 24.4 days pH 9 at 25 o C: 228 days

pH 4 at 50 o C: 0.02 days pH 7 at 50 o C: 1.5 days pH 9 at 50 o C: 8.0 days MRID 46219015 (supplemental) Values may be used in risk assessment. Sterility not confirmed. Sterile buffer solution and glassware were used in

study. Degradate concentrations increased over duration of study.

Half-life, linear regression 1 : pH 4 at 50 o C: 0.02 days pH 7 at 50 o C: 1.2 days pH 9 at 50 o C: 8.6 days MRID 46219016 (supplemental) May be used quantitatively. Study was conducted at 50 o C and sterility was not confirmed. Sterile buffer solution and glassware were used in study.

Atmospheric Degradation Half-life: 0.049 days (estimated) Estimated Using EPIWeb Version 4.0

see Appendix A

. Not likely to undergo long range transport in vapor phase. 3

Aqueous Photolysis Stable MRID 46588509 (supplemental) Study had many deficiencies but was adequate to show that photolysis was not a significant degradation pathway.

Half-lives that were not adjusted for environmental conditions were 85-90 days. Intensity of artificial light was not

compared to natural sunlight. Study duration was 7 days with 94% of the compound remaining. The sterility was not confirmed, temperature range was

25±5 o C, and pH was not reported.

Soil Photolysis No data submitted Not applicable None

Aerobic Soil Metabolism No data submitted Not applicable None

Anaerobic Soil Metabolism No data submitted Not applicable None

### 72 Parameter Value(s) and Units Source (Study Classification) Comments

Aerobic Aquatic Metabolism 4 Half-life, linear regression 1 , at 20 o C:

Parent Only 40.6 and 36.3 (AR, loam soil pH 6.9- 7.25, water pH 7.8-6.81) 24.1 and 21.3 days (CA, clay soil pH 6.0-6.97, water pH 7.7-7.03)

Parent+ Unextracted residues: 70.5 and 59.2 (AR, loam soil pH 6.9- 7.25, water pH 7.8-6.81) 65.4 and 30.3 days (CA, clay soil pH 6.0-6.97, water pH 7.7-7.03) MRID 46219017 (supplemental) Some values were estimated using a subset of data. The values shown are for different rings labeled. Unextracted

residues ranged from not detected to 33% applied radioactivity. Reasonable attempt to extract all residues was not made. Soil used instead of sediment.

Anaerobic Aquatic Metabolism Half-life, linear regression 1 , at 20 o C:

Parent Only: 80 and 89 days (AR water-loam soil pH 6.9-7.45, water pH 7.8-7.44) 41 and 41 days (CA pond-water clay soil pH 6.0-6.72, water pH 7.7-6.82)

Parent+Unextracted Residues: 142 and 217 days (AR water-loam soil pH 6.9-7.45, water pH 7.8-7.44) 88 and 161 days (CA pond-water clay soil pH 6.0-6.72, water pH 7.7-6.82) MRID 46578967 (supplemental) Values may be used in risk assessment as these values are the best available information; however, data are still needed to fully understand degradation of orthosulfamuron in anaerobic aquatic environments. The values shown are for different rings labeled. 5

Sorption coefficients Solid-water distribution Coefficient,
K d in L/kg

6.1, sandy loam, pH 6.3, 1.13%OC 8.6, silt loam, pH 5.7, 2.03%OC 6.3, silt loam, pH 6.8, 1.00%OC 6.1, clay loam, pH 6.1, 2.60% OC

Organic-carbon normalized distribution coefficient, K OC in L/kgOC: 532, sandy loam, pH 6.29, 1.13%OC 425, silt loam, pH 5.71, 2.03%OC 626, silt loam, pH 6.78, 1.00%OC 266, clay loam, pH 6.11, 2.60% OC MRID 46219074 (supplemental) Does not fulfill guideline. Soils from Italy used and information was not provided on whether the soils are representative of U.S. Soils used for rice production. Only four different isotherm data points were included when five are required. None of the test soils had an organic matter content

less than 1%. Material balance only reported for high-dose soils.

### 73 Parameter Value(s) and Units Source (Study Classification) Comments

Solid-water distribution Coefficient,
K d in L/kg 2.5, sandy loam, pH 6.5, 1.04% OC 7.5, sandy loam, pH 5.6, 0.35% OC 3.2, sand, pH 4.70, 1.03% OC 20.7, clay loam, pH 5.4, 3.01% OC 2.0, silt loam, pH 7.5, 0.92% OC 7.0, loam, pH 7.4, 1.8% OC

Organic-carbon normalized distribution coefficient, K OC in L/kgOC: 238, sandy loam, pH 6.5, 1.04%OC 2145, sandy loam, pH 5.6, 0.35% OC 307, sand, pH 4.7, 1.03% OC 687, clay loam, pH 5.4, 3.01% OC 215, silt loam, pH 7.5, 0.92% OC 389, loam, pH 7.4, 1.8% OC MRID 46578971 (supplemental) Material balance and stability only determined in supplementary experiment with soil and test solution.

The recovery of radioactivity in all systems was near 100%. The coefficient of variation(CV) for all K d

values was 76%, 98% for all K OC values, when the outlying high K d and
K OC are removed for the soil with an OC content of 0.35%, the CV was 81% for

Kd values and 42% for K OC values.

Aged Column Leaching Orthosulfamuron not observed in leachate but was observed in Segment D (21 cm depth). DBS-acid, DBS amide, DB amine, o-desmethyl orthosulfamuron, DOP urea, DOP amine, and o-desmethyl DOP urea were all detected at lower segments as well. MRID 46219018 (acceptable) A column was prepared with Arkansas soil/water, orthosulfamuron was added and the column was aged for 69 days. pH in water was 6.9 and 6.2 in CaCl 2 solution.

Soil Column Leaching Orthosulfamuron was the only compound found in leachate and lower soil segments. DOP urea was found in top 0-25 cm of soil and DOP amine was not detected in one soil but was detected in another. Movement through the column indicates that it has the potential to move through soil in environment. MRID 46578968 (supplemental) Only one ring was labeled. Arkansas sandy loam soil and North Dakota sand soil.

Aquatic Field Dissipation Dissipation Half-life 2 , linear regression 1

Arkansas Site: 4.1 days (soil) 6.2 days (sediment) 6.4 days (water)

California Site: 2.3 days (soil) 4.3 days (sediment) Not calculated (water) MRID 46578985 (supplemental) Bareground plots were flooded 1-2 days after application of 0.335 lbs a.i./A.

Storage stability data could not demonstrate stability of test compound

for the maximum storage interval. Recoveries were low for DOP urea and DBS acid. Associated ECM and ILV

are not available for soil and water. Therefore, these values may underestimate the fi eld half-lives and should be considered with an understanding of the data limitations.

### 74 Parameter Value(s) and Units Source (Study Classification) Comments

Steady State Bioconcentration
Factor Measured at 135.2 μg/L at 22-23 o C in Bluegill Sunfish ( Lepomis macrochirus ): 0.29 L/kg wet weight, edible tissue 0.34 L/kg wet weight, nonedible tissue 32 L/kg wet weight, whole fish

16 – 29 L/kg-lipid

Measured at 1391-1550 μg/L at 22- 23 o C: 0.72 L/kg wet weight, edible tissue 1.14 L/kg wet weight, nonedible tissue 0.97 L/kg wet weight, whole fish 52-68 L-kg-lipid 46588507 (acceptable) pH values ranged from 7.5-8.0. TOC in treated aquaria ranged from 33-41 mg/L. Calculations are an average of 5 sampling intervals over 14 days of exposure. It is uncertain whether BCF values were still increasing at the first sampling (4 day) interval. A steady

increase in concentration was not observed over time.

Environmental Chemistry Method: Water None submitted NA None

Environmental Chemistry Method: Soil and Sediment None submitted NA None

Abbreviations: ECM=Environmental Chemistry Method; ILV=independent laboratory Validation

1 Degradation kinetics were calculated us ing the single first order decay equation using either nonlin ear regression of non-transformed data or linear regression of natural log-transformed data.

2 The value may reflect both dissipation and degradation processes.

3 The minutes of the Scientific Adviso ry Panel examining issues related to persistent, bioaccumulative, and toxics states, “To protect against long range tr ansport, a two-day degradation half lif e in air is used internationally in regulations that identify persistent chemicals.” (USEPA, 2009b)

4 MRID 46588508 is an aerobic aquatic metabolism study that was conducted outdoors and samples were exposed to sunlight and fluctuating temperatures. A poor material balance was obtained. The study is considered unacceptable.

5 Unextracted residues ranged from not detected to 43% a pplied radioactivity. Reasonable attempt to extract all residues was not made. The differences in half-lives fo r the different radiolabeled rings for parent+unextracted residues suggests that not all of the un extracted residues are the parent; however, it is not known what fraction is and is not the parent. Hydrolysis rates range with pH and pH range represented is very narrow. The values shown are not representative of the pH range in rice paddies and natural environments (pH 4-10). Microbial biomass was not determined in sediment or water. Limit of quantitation not reported. A soil instead of a sediment was used in the study. Water and sediments were not fully characterized and collection procedures (sam pling depth, temperature, dissolved oxygen content, and microbial biomass) were not reported.

6 MRID 46578970 is unaccept able because no material balance was conducted

### 75 (1) 11.53±0.70 (2) 9.57±0.50 (3) 3.52 ±0.40 and -3.39±0.70 (4) 0.73±0.50 (5) -1.37±0.70

Figure A2. Structure and associated disso ciation constants predicted using Advanced Chemistry Development, I-Labe Web Service.

A1. Sorption Coefficients and Mobility

Table A1 summarizes the sorption coefficients m easured for orthosulfamuron. Freundlich Distribution Coefficients (K F 

### ) values from ten soils range from 2.0 to 20 L/kg (MRID 46219074; 46578971). Freundlich exponents ranged from 0.75 to 1.2 and sorption was influenced by concentration in a few soils. As orthosuflamuron has several pKa values, its affinity to organic materials and other materials in soils and sedime nt are expected to change with pH; however, available data do not support this. Limited data are available to understand the influence of pH on sorption and thus a full analysis of the influe nce of various soil/sediment consituents cannot be fully understood. Nevertheless, available data indicate that th e coefficient of variation (CV) for K OC 

### (115%) is larger than that for K F 

### (79%) across all ten soils studied due to one outlying high K OC 

### value (2,330 L/kg OC 

### ). Upon omission of the outlying K OC 

### value from the remaining nine K OC 

### values (range of 217 – 653 L/kg OC 

### ), the CV for K OC 

### (42%) is less than that for K F 

### (86%), which is expected when organic ca rbon content in soil correlates with K F 

### values. The character of the organic material (which was present at a very low level, at 0.35% organic carbon) in the outlying sorption coefficient co uld explain the higher measured value. K F 

### values correlated with the clay content of soils (p<0.05), but not soil pH (p>0.05; pH range 4.7 to 8.0).

Table A1. Summary of measured sorption coefficients for orthosulfamuron at 20 o 

### C.

Soil, % OC pH K d(L/kgsoil) a K OC (L/kg-OC) b K F (L/kg-soil )-

1/n ) c 1/n e K FOC (L/kg-OC )-1/n ) c Ceq Range d (mg/L)

MRID 46219074 B-1 Sandy Loam, 1.13% pH 6.29 6.01 532 3.76 0.751 283 0.020 – 3.889

### 76 Soil, % OC pH K d(L/kgsoil) a K OC (L/kg-OC) b K F (L/kg-soil )-

1/n ) c 1/n e K FOC (L/kg-OC )-1/n ) c Ceq Range d (mg/L)

G-2 Silt Loam 2.03% pH 5.71 8.62 425 6.62 0.856 326 0.017 – 3.196

M-2 Silt Loam 1.00% pH 6.78 6.26 626 5.47 0.920 547 0.024 – 2.861

VM-1 Clay loam 2.30% pH 7.98 6.11 266 5.72 0.955 249 0.023 – 2.821

MRID 46578971

Ark-1 Sandy
Loam 1.04% pH 6.50 2.48 238 2.37 0.974 228 0.033 – 3.303

Ark-2 Sandy
Loam 0.35% pH 5.66 7.51 2145 8.17 1.062 2330 0.023 - 1.885

Benson Sand 1.03% pH 4.70 3.17 307 3.61 1.152 350 0.033 - 2.695

M-CL Clay
Loam 3.01% pH 5.37 20.68 687 19.7 0.980 653 0.01 – 1.147

PC-1 Silt
Loam 0.92% pH 7.50 1.98 215 2.0 1.019 217 0.039 – 3.669

Pratt Loam 1.80% pH 7.40 6.99 389 6.86 0.990 381 0.02 – 2.192

a K d –Solid-water dist ribution coefficient

b K OC = regressed K d *100/% OC

c K F - Freundlich adsorption coefficients and the Freundlich exponent (1/n)

d K FOC = K F *100/%OC

e Ceq range is the range of orthosulfamuron concentrations in water at equilibrium.



### In column leaching studies, orthosulfamuron, DBS-acid, DBS amide, DB amine, o-desmethyl orthosulfamuron, DOP urea, DOP amine, and o-de smethyl DOP urea were all detected in lower soil segments, demonstrating that movement th rough soil layers is possible for these compounds (MRIDs 46578968 46219018). Column leaching studies of aged orthosulfamuron indicated that some degradates (DBS acid, DBS amide, and o- desmethyl orthosulfamuron) are capable of greater mobility than the parent and are more likely to leach to ground water (MRID 46219018).

### 77 Both orthosulfamuron and its degradates ha ve the potential to leach to groundwater.

A2. Degradation

Abiotic Degradation

Orthosulfamuron hydrolyzed with half-lives of 24.4 and 228 days at 25°C in pH 7 and pH 9 buffered solutions, respectivel y (MRID 46219015, 46578970). The half- lives at pH 4 or 5 are uncertain as data are not available at 25 o 

### C. The half-life of 0.02 days at 50 o 

### C and pH 4 suggests that hydrolysis at pH 5 will be rapid (MRID 46219016). Major identified hydrolysis degradates were DBS acid, DB amine, DOP amine, and DOP urea.

Ninety-four percent of orthosulfamuron remained when irradiated continuously under a filtered xenon lamp for 6.92 days at 25oC in a pH 9 bu ffered solution (MRID 46588509). As 94% was remaining after seven days, it is likely that aqueous photolysis will only play a minor role in the transformation of orthosuflamuron in the en vironment. No major photodegradates were detected.

Biodegradation

The aerobic aquatic metabolism of orthosul famuron was studied us ing pond water-sediment systems from Arkansas and California (MRI D 46219017). Half-lives were calculated by assuming unextracted residues were and were not the parent compound because multiple solvent systems were not employed in extraction and non-extracted residues reached 11-33% of applied. 29 

### Degradation occurred more rapidly unde r aerobic conditions as compared to anaerobic conditions. Total system half-lives for parent and unextracted re sidues in the Arkansas system 30 

### were 70.5 and 59.2 days for pyrimidinyl- and phenyl-labeled orthosulfamuron, respectively. Similar to the anaerobic aquatic metabolism study, degradation appeared to occur more rapidly in the Calif ornia pond-sediment system 31 

### ; total system half-lives for parent and unextracted residues were 65.4 and 30.3 days for pyrimid inyl- and phenyl-labeled orthosulfamuron, respectively. Total sytem half-liv es calculated with extracted parent compound alone were 40.6 and 36.3 days for the pyrimidinyl and phenyl labels in Arkansas, respectively, and 24.1 and 21.3 days for the pyrimidinyl and phenyl labels in California, respectively. The major identified degradates were DBS acid and DOP urea.

An anaerobic aquatic metabolism study was con ducted for orthosulfamu ron using a pond waterloam sediment system from Arkansas for 180 da ys and a pond water-clay sediment system from California for 150 days (MRID 46578967). Ha lf-lives were calcu lated by counting nonextracted residues as parent compound because 1) a portion of unextracted residues could be the parent compound, 2) a reasonable attempt was not made to demonstrate that the extraction

29 Unextracted residues increased throughout the study but did not increase to above 10% until less than 50% of the parent was remaining. This provides some evidence that not all of the unextracted residues are the parent; however, it is stil uncertain whether a portion of the unextracted residues were the parent compound.

30 The Arkansas test system consisted of water from a pond and a loam sediment. The pH of the water was 7.8 and the pH of sediment was 6.2-6.9.

31 The California test system consisted ofr pond water and clay sediment. The pH of the water was 7.7 and pH in sediment porewater was 5.6-6.0.

### 78 procedure removed all possible material, and 3) unextracted residues made up a large portion of measured radioactivity. 32 

### Total system half-lives of pare nt and unextracted residues in the Arkansas sediment were 217 and 142 days for pyrimidinyl- and phenyl-labeled orthosulfamuron, respectively. Degradation occurred more rapidly in the California sediment; total system halflives for the parent and unextra cted residues were 161 and 88 da ys for pyrimidinyl- and phenyllabeled orthosulfamuron, respectively. Total system half-lives calculated with extracted parent compound alone were 89 and 80 da ys for the pyrimidinyl and phenyl labels in Arkansas, respectively, and 41 days for both la bels in California. Calculated half-lives for the parent alone are very similar for the (41 days in California versus 80 and 89 days in Arkansas) while halflives for different labels were different when unextracted residues we re included in the calculation (88 and161 days for California versus 142 and 217 days for Arkansas). This suggests that the unextracted residues were not the parent; however, it is possible that some portion of the unextracted residues were the parent. The major identified degradates were DBS acid, odesmethyl orthosulfamuron, and DOP urea.

A3. Field Studies

A single aquatic field dissipatio n study was conducted for orthos ulfamuron using a bare ground plot of silt loam soil (pH 6.7) in Arkansas and a bare ground plot of silty clay loam soil (pH 7.7) in California (MRID 46578985). The results mu st be considered onl y as supplementary information as recoveries from field spikes were low 33 

### and validated environmental chemistry methods were not provided. 34 

### Measured concentrations coul d underestimate actual half-lives and concentrations. The plots were flooded with water 1–2 days following the application of orthosulfamuron to approximate the timing of herb icide application to rice. Soil samples (0-60 cm depth) were collected through 550-553 days pos t-treatment. Water and the underlying soil (“sediment”; 0-5 cm depth) samples were collecte d from 3 days to 2 months post-treatment. At the Arkansas test site, orthosulfamuron dissipated in the soil (0-15 cm depth), sediment (0-5 cm depth), and water with half-lives of 4.1 days , 6.2 days, and 6.4 days, respectively. At the California site, orthosulfamuron di ssipated in the soil (0-15 cm depth) and sediment (0-5 cm depth) with half-lives of 2.3 days and 4.3 days, respectively. No half-lif e was calculated for the water phase because the chemical wa s not detected in the water.

Both test sites were analyzed for DOP urea, DBS acid, and o-desmethyl orthosulfamuron. Odesmethyl orthosulfamuron was below detection lim its in all samples from both sites. At the Arkansas site, DOP urea and DB S acid were major degradates in the soil and sediment; DBS acid was the major degradate in water. At the California site, DOP urea was the major degradate in soil and sediment; no major degradat es were detected in water.

32 In the California system, unextracted residues were an average of not detected, 6.5, 13.2, 14.0, 17.7, 34.0, and 43.2 percent at 0, 8, 15, 35, 59, 100, and 150 days. In th e Arkansas system, unextracted residues were an average of not detected, 9.8, 10.1, 7.0, 11.7, 18.6, and 24.0 percent at 0, 8, 15, 35, 59, 10, and 150 days respectively.

33 Recoveries from field spiked soil samples for orthosulfamuron, DOP urea, and DBS acid ranged from 47-70%, 58-78%, and 9-34%, respectively. Recoveries from field spiked sediment samples for orthosulfamuron, DOP urea, and DBS acid ranged from 28-106%, 45-82%, and 27-36%, respectively. Recoveries from field spiked water samples for orthosulfamuron, DOP urea, and DBS acid ranged from 63-83%, 87-123%, and 51-96%, respectively.

34 Independent laboratory validation studies were conducted for extraction of IR7825, IR8181, and IR7863 from soil and water that were different than those used in the study.

### 79 A4. Bioconcentration

A flow-through bioconcentration study of bluegill sunfish ( Lepomis macrochirus ) exposed to orthosulfamuron in pH 7.5-8.0 water for 14 days indicates that the compound does not bioconcentrate. Steady State Bioconcentra tion factors (BCF) were 0.29, 0.34, and 0.32 L/kg wet weight for edible, non-edible, and whole fish tissues, respectively, in low-dose samples (142 μg/L) and 0.72, 1.14, and 0.97 L/kg wet weight for edible, non-edible, and whole fish tissues, respectively, in high-dose samples (1420 μg/L). BCF values less than 1,0 00 are not expected to bioconcentrate significantly [64 Fe d. Reg. 60194-60204 (November 4, 1999)].

A5. Transformation Products

The transformation products resu lting from the environmenta l degradation processes of orthosulfamuron are:

• 2-dimethylcarbamoylphenyl sulfamic acid (DBS acid; IR7863; S1);

• 2-sulfamoylamino-N,N-dimethylbenzamide (DBS amide; S2);

• 2-amino-N,N-dimethylbenzam ide (DB amine; S4);

• 1-(4-hydroxy-6-methoxypyrimidin-2 -yl)-3-[2-(dimethylcarbamoyl) phenylsulfamoyl]urea (o-desmethyl or thosulfamuron; IR8181; S9);

• N-(4,6-dimethoxypyrimidin-2-yl)urea (DOP urea; IR7825; S12);

• 4,6-dimethoxypyrimidin-2-yl amine (DOP amine; S13); and

• N-(4-hydroxy-6-methoxypyrimidin-2-yl)urea (o-desmethyl DOP urea; S15).

Two other degradation products S5 and S11 ar e composed of multiple unresolved compounds.

DBS acid (S1), DB amine (S4), o-desmethyl or thosulfamuron (S9), and DOP urea (S12) were the major degradates identified at a maximu m of 62%, 13%, 19%, and 111% of the applied, respectively, detected at 7, 176, 100, and 7 days after treatment, resp ectively. Peak detections of these degradates occurred at up to 100-186 days af ter application. Chemical structures of these degradation products are shown in Appendix J.

The main degradation pathway of orthosulfamuron appears to be the hydrol ytic cleavage of the sulfamoylurea linkage to give DOP urea (S12) and DBS acid (S1). Another degradation pathway is the demethylation of orthosulfamuro n to its o-desmethyl de gradate (S9), which may also degrade to DBS acid. Orthosulfamuron and DBS acid ma y hydrolyze to form DB amine (S4). The maximum amounts of these degrada tion products observed in hydrolysis, aerobic aquatic metabolism, anaerobic aquatic metabolis m, and aquatic field dissipation studies are summarized in Appendix J . No degradation products were detected in the photolysis study. Degradation products were not analyzed for in the hydrolysis study at pH 5.

Table A2. Summary of Storage Stability Studies

Parameter Value(s) and Units Source Comments Storage Stability DBS acid shown to be stable in CA and AR soil and sediment when stored in the dark at 20 o C for 355 days. 46578977 None

### 80 Parameter Value(s) and Units Source Comments

DBS acid and DP amine shown to be stable in surface water (collected from a pond in Italy) stored in the dark below 20 o C for 362 days. 46578978 None

DOP urea shown to be stable in surface water (collected from a pond in Italy) stored in the dark below 20 o C for 388 days. 46578979 None

DOP urea shown to be stable in soil (collected from an AR and CA site) and sediment (from an un treated rice field in Italy) stored in the dark below 20 o C for 386 days. 46578980 None



### A6. Results from AOPwin

SMILES : c2cccc(c2NS(=O)(=O)NC(=O )(Nc1nc(cc(n1)OC)OC))C(=O)N(C)C CHEM : MOL FOR: C16 H20 N6 O6 S1 MOL WT : 424.43

--------------- ---- SUMMARY (AOP v1.92): HYDROXYL RADICALS (25 deg C) -------- Hydrogen Abstraction = 2.7744 E-12 cm3/molecule-sec **Reaction with N, S and -OH = 16.0000 E-12 cm3/molecule-sec Addition to Triple Bonds = 0.0000 E-12 cm3/molecule-sec Addition to Olefinic Bonds = 0.0000 E-12 cm3/molecule-sec **Addition to Aromatic Rings = 200.0000 E-12 cm3/molecule-sec Addition to Fused Rings = 0.0000 E-12 cm3/molecule-sec

OVERALL OH Rate Constant = 218.7744 E-12 cm3/molecule-sec HALF-LIFE = 0.049 Days (12-hr day; 1.5E6 OH/cm3) HALF-LIFE = 0.587 Hrs ........................ ** Designates Estimation(s) Using ASSUMED Value(s)

------------------ - SUMMARY (AOP v1.91): OZONE RE ACTION (25 deg C) -----------

****** NO OZONE REACTION ESTIMATION ****** (ONLY Olefins and Acetylenes are Estimated)

Experimental Database: NO Structure Matches

A7. Estimated K OC 

### values for Degradates:

### 81 Table A3. Summary of Estimated KOC values for Degradates (KOCwin v2.00).

Degradate Name K OC 

### estimate from MCI (L/kg) K OC 

### estimate from Log K OW 

### (L/kg-OC) DBS acid 10 0.08692 DB amine 10 7.4 DOP Amine 10 86.94
DOP urea 10 53.01 DBS Amide 12.09 2.919 o-desmethyl orthosulfamuron 10 13.23

Orthosulfamuron 10 22.28

DBS Acid SMILES : CN(C)C(=O)c1ccccc1NS(=O)(=O)O CHEM : MOL FOR: C9 H12 N2 O4 S1 MOL WT : 244.27 --------------------------- KOCWIN v2.00 Results ---------------------------

Koc Estimate from MCI:

--------------------- First Order Molecular Connectivity Index ........... : 7.310 Non-Corrected Log Koc (0.5213 MCI + 0.60) .......... : 4.4107 Fragment Correction(s): 1 Nitrogen to non-fused aromatic ring ... : -0.5225 2 Nitrogen to Carbon (aliphatic) (-N-C).. : -0.4255 1 Misc (C=O) Group (aliphatic attach).... : -1.6047 1 Mis cellaneous S(=O) group .......... : -1.2980 Corrected Log Koc .................................. : 0.5600 Over Correction Adjustment to Lower Limit Log Koc ... : 1.0000

Estimated Koc: 10 L/kg <===========

Koc Estimate from Log Kow:

------------------------- Log Kow (Kowwin estimate) ......................... : -3.35 Non-Corrected Log Koc (0 .55313 logKow + 0. 9251) .... : -0.9279 Fragment Correction(s): 1 Nitrogen to non-fused aromatic ring ... : -0.0216 2 Nitrogen to Carbon (aliphatic) (-N-C).. : -0.0436 1 Misc (C=O) Group (aliphatic attach).... : -0.2293 1 Miscellaneous S(=O) group .......... : 0.1614 Corrected Log Koc .................................. : -1.0609

Estimated Koc: 0.08692 L/kg <===========

DB amine SMILES : CN(C)C(=O)c1ccccc1N CHEM : MOL FOR: C9 H12 N2 O1 MOL WT : 164.21 --------------------------- KOCWIN v2.00 Results ---------------------------

### 82 Koc Estimate from MCI:

--------------------- First Order Molecular Connectivity Index ........... : 5.626 Non-Corrected Log Koc (0.5213 MCI + 0.60) .......... : 3.5326 Fragment Correction(s): 1 Nitrogen to non-fused aromatic ring ... : -0.5225 2 Nitrogen to Carbon (aliphatic) (-N-C).. : -0.4255 1 Misc (C=O) Group (aliphatic attach).... : -1.6047 Corrected Log Koc .................................. : 0.9799 Over Correction Adjustment to Lower Limit Log Koc ... : 1.0000

Estimated Koc: 10 L/kg <===========

Koc Estimate from Log Kow:

------------------------- Log Kow (Kowwin estimate) ......................... : 0.43 Non-Corrected Log Koc (0 .55313 logKow + 0.9251) .... : 1.1629 Fragment Correction(s): 1 Nitrogen to non-fused aromatic ring ... : -0.0216 2 Nitrogen to Carbon (aliphatic) (-N-C).. : -0.0436 1 Misc (C=O) Group (aliphatic attach).... : -0.2293 Corrected Log Koc .................................. : 0.8685

Estimated Koc: 7.387 L/kg <===========

DOP Amine

SMILES : COc1cc(OC)nc(N)n1 CHEM : MOL FOR: C6 H9 N3 O2 MOL WT : 155.16 --------------------------- KOCWIN v2.00 Results ---------------------------

Koc Estimate from MCI:

--------------------- First Order Molecular Connectivity Index ........... : 5.258 Non-Corrected Log Koc (0.5213 MCI + 0.60) .......... : 3.3406 Fragment Correction(s): 1 Nitrogen to non-fused aromatic ring ... : -0.5225 2 Ether, aromatic (-C-O-C-) ........... : -1.3582 1 Aromatic ring with 2 nitrogens ....... : -0.5964 Corrected Log Koc .................................. : 0.8635 Over Correction Adjustment to Lower Limit Log Koc ... : 1.0000

Estimated Koc: 10 L/kg <===========

Koc Estimate from Log Kow:

------------------------- Log Kow (Kowwin estimate) ......................... : 0.95 Non-Corrected Log Koc (0 .55313 logKow + 0.9251) .... : 1.4506 Fragment Correction(s): 1 Nitrogen to non-fused aromatic ring ... : -0.0216 2 Ether, aromatic (-C-O-C-) ........... : 0.1118 1 Aromatic ring with 2 nitrogens ....... : 0.3984 Corrected Log Koc .................................. : 1.9392

### 83 Estimated Koc: 86.94 L/kg <=========== DOP Urea SMILES : COc1cc(OC )nc(NC(=O)(N))n1 CHEM : MOL FOR: C7 H10 N4 O3 MOL WT : 198.18 --------------------------- KOCWIN v2.00 Results ---------------------------

Koc Estimate from MCI:

--------------------- First Order Molecular Connectivity Index ........... : 6.651 Non-Corrected Log Koc (0.5213 MCI + 0.60) .......... : 4.0672 Fragment Correction(s): 1 Nitrogen to non-fused aromatic ring ... : -0.5225 2 Ether, aromatic (-C-O-C-) ........... : -1.3582 1 Urea (N-CO-N) ........ ............... : -1.0038 1 Aromatic ring with 2 nitrogens ....... : -0.5964 Corrected Log Koc .................................. : 0.5863 Over Correction Adjustment to Lower Limit Log Koc ... : 1.0000

Estimated Koc: 10 L/kg <===========

Koc Estimate from Log Kow:

------------------------- Log Kow (Kowwin estimate) ......................... : 0.58 Non-Corrected Log Koc (0 .55313 logKow + 0.9251) .... : 1.2459 Fragment Correction(s): 1 Nitrogen to non-fused aromatic ring ... : -0.0216 2 Ether, aromatic (-C-O-C-) ........... : 0.1118 1 Urea (N-CO-N) ........ ............... : -0.0102 1 Aromatic ring with 2 nitrogens ....... : 0.3984 Corrected Log Koc .................................. : 1.7243

Estimated Koc: 53.01 L/kg <===========

SMILES : CN(C)C(=O)c1ccccc1N CHEM : MOL FOR: C9 H12 N2 O1 MOL WT : 164.21 --------------------------- KOCWIN v2.00 Results ---------------------------

Koc Estimate from MCI:

--------------------- First Order Molecular Connectivity Index ........... : 5.626 Non-Corrected Log Koc (0.5213 MCI + 0.60) .......... : 3.5326 Fragment Correction(s): 1 Nitrogen to non-fused aromatic ring ... : -0.5225 2 Nitrogen to Carbon (aliphatic) (-N-C).. : -0.4255 1 Misc (C=O) Group (aliphatic attach).... : -1.6047 Corrected Log Koc .................................. : 0.9799 Over Correction Adjustment to Lower Limit Log Koc ... : 1.0000

Estimated Koc: 10 L/kg <===========

Koc Estimate from Log Kow:

-------------------------

### 84 Log Kow (Kowwin estimate) ......................... : 0.43 Non-Corrected Log Koc (0 .55313 logKow + 0.9251) .... : 1.1629 Fragment Correction(s): 1 Nitrogen to non-fused aromatic ring ... : -0.0216 2 Nitrogen to Carbon (aliphatic) (-N-C).. : -0.0436 1 Misc (C=O) Group (aliphatic attach).... : -0.2293 Corrected Log Koc .................................. : 0.8685

Estimated Koc: 7.387 L/kg <===========

DBS Amide

SMILES : CN(C)C(=O)c1ccccc1CS(N)(=O)=O CHEM : MOL FOR: C10 H14 N2 O3 S1 MOL WT : 242.29 --------------------------- KOCWIN v2.00 Results ---------------------------

Koc Estimate from MCI:

--------------------- First Order Molecular Connectivity Index ........... : 7.310 Non-Corrected Log Koc (0.5213 MCI + 0.60) .......... : 4.4107 Fragment Correction(s): 2 Nitrogen to Carbon (aliphatic) (-N-C).. : -0.4255 1 Misc (C=O) Group (aliphatic attach).... : -1.6047 1 Mis cellaneous S(=O) group .......... : -1.2980 Corrected Log Koc .................................. : 1.0825

Estimated Koc: 12.09 L/kg <===========

Koc Estimate from Log Kow:

------------------------- Log Kow (Kowwin estimate) ......................... : -0.63 Non-Corrected Log Koc (0 .55313 logKow + 0.9251) .... : 0.5766 Fragment Correction(s): 2 Nitrogen to Carbon (aliphatic) (-N-C).. : -0.0436 1 Misc (C=O) Group (aliphatic attach).... : -0.2293 1 Miscellaneous S(=O) group .......... : 0.1614 Corrected Log Koc .................................. : 0.4652

Estimated Koc: 2.919 L/kg <===========

O-desmethyl orthosofulamuron SMILES : COc2cc(O)nc (NC(=O)NS(=O)(=O)N c1ccccc1C(=O)N(C)C)n2 CHEM : MOL FOR: C15 H18 N6 O6 S1 MOL WT : 410.41 --------------------------- KOCWIN v2.00 Results ---------------------------

Koc Estimate from MCI:

--------------------- First Order Molecular Connectivity Index ........... : 13.108 Non-Corrected Log Koc (0.5213 MCI + 0.60) .......... : 7.4331 Fragment Correction(s): 2 Nitrogen to non-fused aromatic ring ... : -1.0450

### 85 1 Ether, aromatic (-C-O-C-) ........... : -0.6791 1 Urea (N-CO-N) ........ ............... : -1.0038 2 Nitrogen to Carbon (aliphatic) (-N-C).. : -0.4255 1 Aromatic ring with 2 nitrogens ....... : -0.5964 1 Misc (C=O) Group (aliphatic attach).... : -1.6047 1 Mis cellaneous S(=O) group .......... : -1.2980 1 Aromatic Hydroxy (aromatic-OH) ....... : -0.0966 Corrected Log Koc .................................. : 0.6840 Over Correction Adjustment to Lower Limit Log Koc ... : 1.0000

Estimated Koc: 10 L/kg <===========

Koc Estimate from Log Kow:

------------------------- Log Kow (Kowwin estimate) ......................... : -0.47 Non-Corrected Log Koc (0 .55313 logKow + 0.9251) .... : 0.6651 Fragment Correction(s): 2 Nitrogen to non-fused aromatic ring ... : -0.0432 1 Ether, aromatic (-C-O-C-) ........... : 0.0559 1 Urea (N-CO-N) ........ ............... : -0.0102 2 Nitrogen to Carbon (aliphatic) (-N-C).. : -0.0436 1 Aromatic ring with 2 nitrogens ....... : 0.3984 1 Misc (C=O) Group (aliphatic attach).... : -0.2293 1 Miscellaneous S(=O) group .......... : 0.1614 1 Aromatic Hydroxy (aromatic-OH) ....... : 0.1668 Corrected Log Koc .................................. : 1.1215

Estimated Koc: 13.23 L/kg <===========

Orthosulfamuron SMILES : CN(C(=O)c2ccccc2NS(=O)( =O)NC(=O)Nc1nc(cc(n1)OC)OC)C CHEM : MOL FOR: C16 H20 N6 O6 S1 MOL WT : 424.43 --------------------------- KOCWIN v2.00 Results ---------------------------

Koc Estimate from MCI:

--------------------- First Order Molecular Connectivity Index ........... : 13.646 Non-Corrected Log Koc (0.5213 MCI + 0.60) .......... : 7.7136 Fragment Correction(s): 2 Nitrogen to non-fused aromatic ring ... : -1.0450 2 Ether, aromatic (-C-O-C-) ........... : -1.3582 1 Urea (N-CO-N) ........ ............... : -1.0038 2 Nitrogen to Carbon (aliphatic) (-N-C).. : -0.4255 1 Aromatic ring with 2 nitrogens ....... : -0.5964 1 Misc (C=O) Group (aliphatic attach).... : -1.6047 1 Mis cellaneous S(=O) group .......... : -1.2980 Corrected Log Koc .................................. : 0.3820 Over Correction Adjustment to Lower Limit Log Koc ... : 1.0000

Estimated Koc: 10 L/kg <===========

Koc Estimate from Log Kow:

------------------------- Log Kow (Kowwin estimate) ......................... : 0.14

### 86 Non-Corrected Log Koc (0 .55313 logKow + 0.9251) .... : 1.0025 Fragment Correction(s): 2 Nitrogen to non-fused aromatic ring ... : -0.0432 2 Ether, aromatic (-C-O-C-) ........... : 0.1118 1 Urea (N-CO-N) ........ ............... : -0.0102 2 Nitrogen to Carbon (aliphatic) (-N-C).. : -0.0436 1 Aromatic ring with 2 nitrogens ....... : 0.3984 1 Misc (C=O) Group (aliphatic attach).... : -0.2293 1 Miscellaneous S(=O) group .......... : 0.1614 Corrected Log Koc .................................. : 1.3480

Estimated Koc: 22.28 L/kg <===========

### Append i Structu r

In order t parent th herbicid e found th a chlorox u and para l Life Ben pesticid e pesticid e

Table B 1 Similar S

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a rk = Toxicity v

e d test (usuall y

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a rly life stage t e

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Monuron

Parafluron oxuron90Table B2. Summary of Terrestrial Plant Toxicity Data forUrea Herbicides and Orthosulfamuron from Internal EPAECOTOXICITY Database (searched August 16, 2011)CHEMICALCOMMON NAME SPECIESGUIDELINE TYPE AISTUDYTIMEDOSETYPE TGLTOXICITYTOXLEVEL CL NGL NOEL CATEGORYOrthosulfamuronMungbeanPhaseolusaureus 123-1bVVdw 49.96 21 D EC25 < 0.00169 lbA N.A. 0.00514 SFluometuron LettuceLactucasativa 123-1a SE 97.2 21 D EC25 .006 LBA N.R. 0.002 CDiuron TomatoLycopersiconesculentum 123-1bVVsw 97.3 21 D EC25 0.0017 LBA N.R. 0.0010Linuron CucumberCucumissativus 123-1b VVsh 97.6 21 D EC25 0.0021 LBA0.0013-0.003 0.0005Linuron CucumberCucumissativus 123-1b VVsh 97.6 21 D EC25 0.0021 LBA0.0013-0.003 0.0005Linuron OnionAlliumcepa 123-1b VVrw 98.4 21 D EC25 0.0028 LBA NA 0.0064 SLinuron OnionAlliumcepa 123-1b VVrw 98.4 21 D EC25 0.0028 LBA NA 0.0064 SDiuron CucumberCucumissativus 123-1bVVsw 97.3 21 D EC25 0.0053 LBA N.R. 0.0050Fluometuron LettuceLactucasativa 123-1a SEsw 97.2 14 D EC25 0.006 LBA N.R. 0.002 CDiuron SugarbeetBetavulgaris 123-1bVVsw 97.3 21 D EC25 0.0087 LBA N.R. 0.0050Fluometuron CucumberCucumissativus 123-1b VV 97.2 21 D EC25 0.009 LBA N.R. 0.002 CDiuron SoybeanGlycinemax 123-1bVVsw 97.3 21 D EC25 0.012 LBA N.R. 0.002Fluometuron CabbageBrassicaoleracea 123-1a SEsh 97.2 14 D EC25 0.012 LBA N.R. 0.006 C91CHEMICALCOMMON NAME SPECIESGUIDELINE TYPE AISTUDYTIMEDOSETYPE TGLTOXICITYTOXLEVEL CL NGL NOEL CATEGORYDiuronGardenpeaPisumsativum 123-1bVVsw 97.3 21 D EC25 0.0138 LBA N.R. 0.0029Fluometuron CucumberCucumissativus 123-1b VG 97.2 21 D EC25 0.019 LBA N.R. 0.002 CFluometuron CucumberCucumissativus 123-1a SEsw 97.2 14 D EC25 0.020 LBA N.R. 0.0063 CDiuron WheatTriticumaestivum 123-1bVVsw 97.3 21 D EC25 0.0208 LBA N.R. 0.0017Linuron TomatoLycopersiconesculentum 123-1bVVsw 98.4 21 D EC25 0.026 LBA NA 0.0064 SFluometuron Corn Zea mays 123-1a SE 97.2 21 D EC25 0.026 LBA N.R. 0.019 CLinuron TomatoLycopersiconesculentum 123-1bVVsw 98.4 21 D EC25 0.026 LBA NA 0.0064 SLinuronOilseedrapeBrassicanapus 123-1bVVsw 98.4 21 D EC25 0.03 LBA NA 0.032 STebuthiuron CabbageBrassicaoleracea 123-1aSE/VV 99.6 7-21D EC25 0.03 LBA N.R. N.R. CLinuronOilseedrapeBrassicanapus 123-1bVVsw 98.4 21 D EC25 0.03 LBA NA 0.032 SFluometuron Corn Zea mays 123-1a SEsw 97.2 14 D EC25 0.030 LBA N.R. 0.019 CFluometuron OnionAlliumcepa 123-1a SEsw 97.2 14 D EC25 0.031 LBA N.R. 0.019 CLinuron RapeseedBrassicacompestris 123-1bVVsw 97.6 21 D EC25 0.033 LBA N.R. 0.03292CHEMICALCOMMON NAME SPECIESGUIDELINE TYPE AISTUDYTIMEDOSETYPE TGLTOXICITYTOXLEVEL CL NGL NOEL CATEGORYFluometuron TomatoLycopersiconesculentum 123-1a SEsw 97.2 14 D EC25 0.033 LBA N.R. 0.019 CLinuron RapeseedBrassicacompestris 123-1bVVsw 97.6 21 D EC25 0.033 LBA N.R. 0.032Diuron RapeBrassicasp. 123-1bVVsw 97.3 21 D EC25 0.0331 LBA N.R. 0.0117Linuron TomatoLycopersiconesculentum 123-1bVVsw 97.6 21 D EC25 0.034 LBA N.R. < 0.034Linuron TomatoLycopersiconesculentum 123-1bVVsw 97.6 21 D EC25 0.034 LBA N.R. < 0.034Fluometuron OatAvenasativa 123-1b VVG 97.2 21 D EC25 0.035 LBA N.R. 0.019 CDiuron TomatoLycopersiconesculentum 123-1a SE 96.8 14 D EC25 > 0.038 LBA NA 0.019 CFluometuron OatAvenasativa 123-1a SEsw 97.2 14 D EC25 0.038 LBA N.R. 0.019 CFluometuron RadishRaphanussativus 123-1a SEsw 97.2 14 D EC25 0.045 LBA N.R. 0.019 CLinuron OnionAlliumcepa 123-1a SEsw 97.6 14 D EC25 0.049 LBA0.016-0.147 0.016Linuron OnionAlliumcepa 123-1a SEsw 97.6 14 D EC25 0.049 LBA0.016-0.147 0.01693CHEMICALCOMMON NAME SPECIESGUIDELINE TYPE AISTUDYTIMEDOSETYPE TGLTOXICITYTOXLEVEL CL NGL NOEL CATEGORYTebuthiuron RadishRaphanussativus 123-1aSE/VV 99.6 7-21D EC25 0.05 LBA N.R. N.R. CLinuron WheatTriticumaestivum 123-1bVVsw 97.6 21 D EC25 0.051 LBA N.R. 0.032Fluometuron CabbageBrassicaoleracea 123-1b VV 97.2 21 D EC250.051 LBA N.R. 0.019 CLinuron WheatTriticumaestivum 123-1bVVsw 97.6 21 D EC25 0.051 LBA N.R. 0.032Fluometuron OatAvenasativa 123-1b VV 97.2 21 DLOEC 0.057 LBA N.R. 0.019 CFluometuron SoybeanGlycinemax 123-1b VV 97.2 21 DLOEC 0.057 LBA N.R. 0.019 CFluometuron CucumberCucumissativus 123-1b VV 97.2 21 DLOEC 0.057 LBA N.R. 0.019 CFluometuron RadishRaphanussativus 123-1b VV 97.2 21 DLOEC 0.057 LBA N.R. 0.019 CFluometuron TomatoLycopersiconesculentum 123-1b VV 97.2 21 DLOEC 0.057 LBA N.R. 0.019 CFluometuron CabbageBrassicaoleracea 123-1b VV 97.2 21 DLOEC 0.057 LBA N.R. 0.019 CTebuthiuron CucumberCucumissativus 123-1aSE/VV 99.6 7-21D EC25 0.06 LBA N.R. N.R. CLinuron SugarbeetBetavulgaris 123-1a SEsw 97.6 14 D EC25 0.061 LBA0.016-0.237 0.016Linuron SugarbeetBetavulgaris 123-1a SEsw 97.6 14 D EC25 0.061 LBA0.016-0.237 0.016Fluometuron CabbageBrassicaoleracea 123-1b VV 97.2 21 D EC250.065 LBA N.R. 0.019 CFluometuron SoybeanGlycinemax 123-1a SEsw 97.2 14 D EC25 0.069 LBA N.R. 0.019 C94CHEMICALCOMMON NAME SPECIESGUIDELINE TYPE AISTUDYTIMEDOSETYPE TGLTOXICITYTOXLEVEL CL NGL NOEL CATEGORYTebuthiuron WheatTriticumaestivum 123-1aSE/VV 99.6 7-21D EC25 0.07 LBA N.R. N.R. CFluometuron RyegrassLoliumperenne 123-1a SEsh 97.2 14 D EC25 0.071 LBA N.R. 0.019 CLinuron OnionAlliumcepa 123-1bVVsw 97.6 21 D EC25 0.073 LBA N.R. < 0.073Linuron OnionAlliumcepa 123-1bVVsw 97.6 21 D EC25 0.073 LBA N.R. < 0.073Diuron TomatoLycopersiconesculentum 123-1a SEsw 97.3 14 D EC25 0.075 LBA0.049-.116 0.047Diuron SorghumSorghumbicolor 123-1bVVsw 97.3 21 D EC25 0.0753 LBA N.R. 0.0117Fluometuron OatAvenasativa 123-1b VV 97.2 21 D EC25 0.078 LBA N.R. 0.019 CDiuron OnionAlliumcepa 123-1a SEsw 97.3 14 D EC25 0.086 LBA0.062-.104 0.047Diuron SugarbeetBetavulgaris 123-1a SEsw 97.3 14 D EC25 0.092 LBA N.R. 0.047Diuron RapeBrassicasp. 123-1a SEsw 97.3 14 D EC25 0.094 LBA N.R. 0.047Fluometuron OatAvenasativa 123-1b VV 97.2 21 D EC25 0.12 LBA N.R. 0.057 CLinuron SugarbeetBetavulgaris 123-1a SEsh 98.4 14 D EC25 0.14 LBA NA 0.032 SLinuron SugarbeetBetavulgaris 123-1a SEsh 98.4 14 D EC25 0.14 LBA NA 0.032 SDiuron OnionAlliumcepa 123-1bVVsw 97.3 21 D EC25 0.148 LBA N.R. 0.094LinuronGardenpeaPisumsativum 123-1bVVsw 97.6 21 D EC25 0.17 LBA N.R. 0.032 C95CHEMICALCOMMON NAME SPECIESGUIDELINE TYPE AISTUDYTIMEDOSETYPE TGLTOXICITYTOXLEVEL CL NGL NOEL CATEGORYLinuronGardenpeaPisumsativum 123-1bVVsw 97.6 21 D EC25 0.17 LBA N.R. 0.032 CLinuron RapeBrassicasp. 123-1a SEsh 97.6 14 D EC25 0.18 LBA N.R. 0.10Linuron RapeBrassicasp. 123-1a SEsh 97.6 14 D EC25 0.18 LBA N.R. 0.10Linuron SoybeanGlycinemax 123-1b VVsh 97.6 21 D EC25 0.21 LBA N.R. 0.006Linuron SoybeanGlycinemax 123-1b VVsh 97.6 21 D EC25 0.21 LBA N.R. 0.006Linuron Corn Zea mays 123-1bVVsw 97.6 21 D EC25 0.26 LBA N.R. 0.16Linuron Corn Zea mays 123-1bVVsw 97.6 21 D EC25 0.26 LBA N.R. 0.16Linuron TomatoLycopersiconesculentum 123-1a SEsh 97.6 14 D EC25 0.28 LBA N.R. < 0.28Linuron TomatoLycopersiconesculentum 123-1a SEsh 97.6 14 D EC25 0.28 LBA N.R. < 0.28Diuron CucumberCucumissativus 123-1a SEsh 97.3 14 D EC25 0.34 LBA N.R. 0.19Diuron Corn Zea mays 123-1bVVsw 97.3 21 D EC25 0.39 LBA N.R. 0.19Linuron CucumberCucumissativus 123-1a SEsh 97.6 14 D EC25 0.61 LBA N.R. 0.40Linuron CucumberCucumissativus 123-1a SEsh 97.6 14 D EC25 0.61 LBA N.R. 0.40Diuron SorghumSorghumbicolor 123-1a SEsh 97.3 14 D EC25 0.81 LBA N.R. 0.7596CHEMICALCOMMON NAME SPECIESGUIDELINE TYPE AISTUDYTIMEDOSETYPE TGLTOXICITYTOXLEVEL CL NGL NOEL CATEGORYLinuron SorghumSorghumbicolor 123-1bVVsw 97.6 21 D EC25 0.96 LBA N.R. 0.16Linuron SorghumSorghumbicolor 123-1bVVsw 97.6 21 D EC25 0.96 LBA N.R. 0.16Fluometuron LettuceLactucasativa 123-1a SG 97.2 6 D EC25 0.97 LBA N.R. 0.58 CDiuron WheatTriticumaestivum 123-1a SEsw 97.3 14 D EC25 1.05 LBA N.R. 0.38Linuron SorghumSorghumbicolor 123-1a SEsh 97.6 14 D EC25 1.4 LBA N.R. 1.0Linuron SorghumSorghumbicolor 123-1a SEsh 97.6 14 D EC25 1.4 LBA N.R. 1.0Diuron SugarbeetBetavulgaris 123-1a SEsh 96.8 14 D EC25 < 12 LBA NA 0.19 CDiuron SoybeanGlycinemax 123-1a SE 96.8 14 D EC25 > 12 LBA NA 12 CDiuronOilseedrapeBrassicanapus 122-1a SEsh 96.8 14 D EC25 < 12 LBA NA 0.093 CDiuron SorghumSorghumhalepense 123-1a SEsh 96.8 14 D EC25 < 12 LBA NA 0.75 CDiuron WheatTriticumaestivum 122-1a SEsh 96.8 14 D EC25 < 12 LBA NA 0.75 SDiuron OnionAlliumcepa 123-1a SEsh 96.8 14 D EC25 < 12 LBA NA 0.19 CDiuronGardenpeaPisumsativum 123-1a SEsh 97.3 14 D EC25 > 12 LBA N.R. 12Diuron SoybeanGlycinemax 123-1a SEsh 97.3 14 D EC25 > 12 LBA N.R. 12FluometuronVeg.Crops(11 Sp.)Monocots& Dicots 122-1 SGpy 96.4 5 DLOEC > 2.0 LBA N.A. < 2.0 C97CHEMICALCOMMON NAME SPECIESGUIDELINE TYPE AISTUDYTIMEDOSETYPE TGLTOXICITYTOXLEVEL CL NGL NOEL CATEGORYLinuron TomatoLycopersiconesculentum 123-1a SE 98.4 14 D EC25 > 20 LBA NA 4.0 SLinuron TomatoLycopersiconesculentum 123-1a SE 98.4 14 D EC25 > 20 LBA NA 4.0 SLinuron WheatTriticumaestivum 123-1a SEsh 97.6 14 D EC25 3.8 LBA N.R. 0.5Linuron WheatTriticumaestivum 123-1a SEsh 97.6 14 D EC25 3.8 LBA N.R. 0.5Linuron OnionAlliumcepa 122-1a SEsh 98.4 14 D EC25 > 4.0 LBA NA 4.0 CLinuronOilseedrapeBrassicanapus 122-1a SEsh 98.4 14 D EC25 > 4.0 LBA NA < 4.0 CLinuron SoybeanGlycinemax 122-1a SEsh 98.4 14 D EC25 > 4.0 LBA NA 4.0 CLinuron WheatTriticumaestivum 122-1a SEsh 98.4 14 D EC25 > 4.0 LBA NA 4.0 CLinuron SugarbeetBetavulgaris 122-1a SEsh 98.4 14 D EC25 > 4.0 LBA NA < 4.0 CLinuron SoybeanGlycinemax 123-1a SE 98.4 14 D EC25 > 4.0 LBA NA > 4.0 CLinuron SorghumSorghumhalepense 123-1a SE 98.4 14 D EC25 > 4.0 LBA ND 1.0 CLinuron WheatTriticumaestivum 123-1a SE 98.4 14 D EC25 > 4.0 LBA NR > 4.0 CLinuron Corn Zea mays 123-1a SEsh 97.6 14 D EC25 > 4.0 LBA N.A. 4.0Linuron SoybeanGlycinemax 123-1a SEsh 97.6 14 D EC25 > 4.0 LBA N.R. 4.098CHEMICALCOMMON NAME SPECIESGUIDELINE TYPE AISTUDYTIMEDOSETYPE TGLTOXICITYTOXLEVEL CL NGL NOEL CATEGORYLinuronGardenpeaPisumsativum 123-1a SEsh 97.6 14 D EC25 > 4.0 LBA N.R. 4.0Linuron OnionAlliumcepa 122-1a SEsh 98.4 14 D EC25 > 4.0 LBA NA 4.0 CLinuronOilseedrapeBrassicanapus 122-1a SEsh 98.4 14 D EC25 > 4.0 LBA NA < 4.0 CLinuron SoybeanGlycinemax 122-1a SEsh 98.4 14 D EC25 > 4.0 LBA NA 4.0 CLinuron WheatTriticumaestivum 122-1a SEsh 98.4 14 D EC25 > 4.0 LBA NA 4.0 CLinuron SugarbeetBetavulgaris 122-1a SEsh 98.4 14 D EC25 > 4.0 LBA NA < 4.0 CLinuron SoybeanGlycinemax 123-1a SE 98.4 14 D EC25 > 4.0 LBA NA > 4.0 CLinuron SorghumSorghumhalepense 123-1a SE 98.4 14 D EC25 > 4.0 LBA ND 1.0 CLinuron WheatTriticumaestivum 123-1a SE 98.4 14 D EC25 > 4.0 LBA NR > 4.0 CLinuron Corn Zea mays 123-1a SEsh 97.6 14 D EC25 > 4.0 LBA N.A. 4.0Linuron SoybeanGlycinemax 123-1a SEsh 97.6 14 D EC25 > 4.0 LBA N.R. 4.0LinuronGardenpeaPisumsativum 123-1a SEsh 97.6 14 D EC25 > 4.0 LBA N.R. 4.0Fluometuron OnionAlliumcepa 123-1a SG 97.2 6 D EC25 > 4.6 LBA N.A. 2.3 CDiuron Corn Zea mays 123-1a SEsh 97.3 14 D EC25 5.7 LBA N.R. 0.75TebuthiuronCropplants(10sp.)Monocots& Dicots 122-1 SG 99.6 5 D EC25 N.R. LBA N.A. > 6 C99CHEMICALCOMMON NAME SPECIESGUIDELINE TYPE AISTUDYTIMEDOSETYPE TGLTOXICITYTOXLEVEL CL NGL NOEL CATEGORYLinuron OnionAlliumcepa 123-1a SE 98.4 14 D EC25 NR LBA NA 0.8 SLinuronOilseedrapeBrassicanapus 123-1a SE 98.4 14 D EC25 NR LBA NA > 0.4 CLinuron OnionAlliumcepa 123-1a SE 98.4 14 D EC25 NR LBA NA 0.8 SLinuronOilseedrapeBrassicanapus 123-1a SE 98.4 14 D EC25 NR LBA NA > 0.4 CTable B3. Summary of LC50Values for Birds for Urea Herbicides and Orthosulfamuron from Internal EPA ECOTOXICITYDatabase (searched August 16, 2011). Bold valuesare lower than the values for orthosulfamuron.CHEMICALCOMMON NAME SPECIES AGEGUIDELINE TYPE AISTUDYTIMEDOSETYPETGL TOXICITY Units CLNGL NOELCATEGORYLinuronBobwhitequailColinusvirginianus 10 D 71-2a D 97.6 8 D LC50 1700 PPM1350-2150 < 169 CLinuronBobwhitequailColinusvirginianus 10 D 71-2a D 97.6 8 D LC50 1700 PPM1350-2150 < 169 CDiuronBobwhitequailColinusvirginianus 9 D 71-2a D >95 8 D LC50 1730 PPM1482-2035 N.R. CTebuthiuronMallardduckAnasplatyrhynchos 7 D 71-2b D 98 8 D LC50 > 2500 PPM N.R. N.R. STebuthiuronBobwhitequailColinusvirginianus 7 D 71-2a D 98 8 D LC50 > 2500 PPM N.R. N.R. S100CHEMICALCOMMON NAME SPECIES AGEGUIDELINE TYPE AISTUDYTIMEDOSETYPETGL TOXICITY Units CLNGL NOELCATEGORYLinuronMallardduckAnasplatyrhynchos 5 D 71-2b D 50WP 8 D LC50 3083 PPM2419-3990 N.R. CLinuronMallardduckAnasplatyrhynchos 5 D 71-2b D 50WP 8 D LC50 3083 PPM2419-3990 N.R. CFluometuronRingneckedpheasantPhasianuscolchicus8-16D 71-2 D Tech 8 D LC50 3150 PPM1750-5670 N.R. CLinuronRingneckedpheasantPhasianuscolchicus 10 D 71-2 D 50WP 8 D LC50 3438 PPM2874-4139 N.R. CLinuronRingneckedpheasantPhasianuscolchicus 10 D 71-2 D 50WP 8 D LC50 3438 PPM2874-4139 N.R. CFluometuronBobwhitequailColinusvirginianus 1 D 71-2a D 97.5 8 D LC50 > 3474 PPM N.A. 1850 CFluometuronMallardduckAnasplatyrhynchos8-16D 71-2b D Tech 8 D LC50 4500 PPM3400-5960 N.R. CFluometuronBobwhitequailColinusvirginianus8-16D 71-2a D Tech 8 D LC50 4620 PPM3250-6550 N.R. SMonuronRingneckedpheasantPhasianuscolchicus 15 D 71-2 D Tech 8 D LC50 4682 PPM3902-5746 N.R. SOrthosulfamuronMallardduckAnasplatyrhynchos 9 D 71-2b D 97.99 8 D LC50 > 4790 PPM1001-5000 4790 C101CHEMICALCOMMON NAME SPECIES AGEGUIDELINE TYPE AISTUDYTIMEDOSETYPETGL TOXICITY Units CLNGL NOELCATEGORYLinuronMallardduckAnasplatyrhynchos 10 D 71-2b D 97.6 8 D LC50 4880 PPM970-Inf. < 169 CLinuronMallardduckAnasplatyrhynchos 10 D 71-2b D 97.6 8 D LC50 4880 PPM970-Inf. < 169 COrthosulfamuronBobwhitequailColinusvirginianus 14 D 71-2a D 97.99 8 D LC50 > 4980 PPM N.A. 4980 CLinuronJapanesequailCoturnixjaponica 14 D 71-2a D 50WP 8 D LC50 > 5000 PPM N.R. N.R. SDiuronJapanesequailCoturnixjaponica 12 D 71-2 D >95 8 D LC50 > 5000 PPM N.R. N.R. SDiuronRingneckedpheasantPhasianuscolchicus 15 D 71-2 D >95 8 D LC50 > 5000 PPM N.R. N.R. CDiuronMallardduckAnasplatyrhynchos 10 D 71-2b D >95 8 D LC50 > 5000 PPM N.R. N.R. CLinuronJapanesequailCoturnixjaponica 14 D 71-2a D 50WP 8 D LC50 > 5000 PPM N.R. N.R. SMonuronMallardduckAnasplatyrhynchos 10 D 71-2b D Tech 8 D LC50 > 5000 PPM N.A. 1250 SMonuronJapanesequailCoturnixjaponica 12 D 71-2 D Tech 8 D LC50 > 5000 PPM N.A. 1250 SMonuronBobwhitequailColinusvirginianus 17 D 71-2a D Tech 8 D LC50 > 5000 PPM N.A. N.R. STebuthiuronMallardduckAnasplatyrhynchos 4 D 71-2b D 99.1 8 D LC50 > 5093 PPM N.R. N.R. C102CHEMICALCOMMON NAME SPECIES AGEGUIDELINE TYPE AISTUDYTIMEDOSETYPETGL TOXICITY Units CLNGL NOELCATEGORYTebuthiuronBobwhitequailColinusvirginianus 11 D 71-2a D 99.1 8 D LC50 > 5113 PPM N.R. N.R. CFluometuronBobwhitequailColinusvirginianus 10 D 71-2a D 97.8 8 D LC50 > 5620 PPM N.A. 562 CTable B4. Summary of LD50Values for Birds for Urea Herbicides and Orthosulfamuron from Internal EPA ECOTOXICITYDatabase (searched August 16, 2011). Bold valuesare lower than the values for orthosulfamuron.CHEMICALCOMMON NAME SPECIES AGEGUIDELINE AISTUDYTIMEDOSETYPETGLTOXVALUETOXLEVEL CLNGLNOELCATEGORYLinuronBobwhitequailColinusvirginianus 17WKS 71-1 92.4 21 D LD50 940 MGK712-1262 292 CLinuronBobwhitequailColinusvirginianus 17WKS 71-1 92.4 21 D LD50 940 MGK712-1262 292 CTebuthiuronMallardduckAnasplatyrhynchos 12 MOS 71-1 98 14 D LD50 > 500 MGK N.R. N.R. STebuthiuronBobwhitequailColinusvirginianus=>4MOS 71-1 98 14 D LD50 > 500 MGK N.R. N.R. STebuthiuronWhiteRockCross Gallus sp. Adult 71-1 98 14 D LD50 > 500 MGK N.R. N.R. SFluometuronMallardduckAnasplatyrhynchos 14 D 71-1 Tech 14 D LD50 2974 MGK2060-4296 N.A. C103CHEMICALCOMMON NAME SPECIES AGEGUIDELINE AISTUDYTIMEDOSETYPETGLTOXVALUETOXLEVEL CLNGLNOELCATEGORYDiuronMallardduckAnasplatyrhynchos 3 MOS 71-1 95 14 D LD50 > 2000 MGK N.R. N.R. CTebuthiuronMallardduckAnasplatyrhynchos 9 MOS 71-1 98 14 D LD50 > 2000 MGK N.R. N.R. CFluometuronMallardduckAnasplatyrhynchos 3,4MOS 71-180WP 14 D LD50 > 2000 MGK N.A. N.A. COrthosulfamuronMallardduckAnasplatyrhynchos Adult 71-197.99 14 D LD50 > 1960 MGK N.A. 1960 COrthosulfamuronBobwhitequailColinusvirginianus 8 M 71-197.99 14 D LD50 > 1960 MGK N.A. 1960 CTable B5. Summary of NOAEC for Birds for Urea Herbicides and Orthosulfamuron from Internal EPA ECOTOXICITYDatabase (searched August 16, 2011). Bold valuesare lower than the values for orthosulfamuron.CHEMICALCOMMON NAME SPECIES AGEGUIDELINE AISTUDYTIMEDOSETYPETGLTOXVALUETOXLEVEL CLNGLNOELCATEGORYTebuthiuronMallardduckAnasplatyrhynchosErlyLf 71-4b 96.422WKSLOEL > 100 PPMN.R. 100 CTebuthiuronBobwhitequailColinusvirginianusErlyLf 71-4a 96.422WKSLOEL > 100 PPMN.R. 100 CFluometuronMallardduckAnasplatyrhynchosErlyLf 71-4 97.8 20 wkLOEC 102 PPMN.A. 60.4 C104CHEMICALCOMMON NAME SPECIES AGEGUIDELINE AISTUDYTIMEDOSETYPETGLTOXVALUETOXLEVEL CLNGLNOELCATEGORYOrthosulfamuronMallardduckAnasplatyrhynchosErlyLf 71-498.56 21 WkLOEL > 1280 PPMN.A. 1280 COrthosulfamuronBobwhitequailColinusvirginianusErlyLf 71-498.56 21 WkLOEL > 1280 PPMN.A. 1280 CFluometuronBobwhitequailColinusvirginianusErlyLf 71-4 98.8 25 wkLOEC 146 PPMN.A. 42.8 INLinuronBobwhitequailColinusvirginianusErlyLf 71-4a 98.422WKSLOEL 300 PPMN.A. 100 CLinuronMallardduckAnasplatyrhynchosErlyLf 71-4b 98.420WKSLOEL < 300 PPMN.A. 100 CLinuronBobwhitequailColinusvirginianusErlyLf 71-4a 98.422WKSLOEL 300 PPMN.A. 100 CLinuronMallardduckAnasplatyrhynchosErlyLf 71-4b 98.420WKSLOEL < 300 PPMN.A. 100 CTable B6. Summary of Toxicity Data for Honeybees forUrea Herbicides and Orthosulfamuron from Internal EPAECOTOXICITY Database (searched August 16, 2011). Bold values are lower than the values for orthosulfamuron.CHEMICALCOMMON NAMESPECIES AGEGUIDELINE AISTUDYTIMEDOSETYPETGLTOXVALUETOXLEVEL CLNGLNOELCATEGORYTebuthiuron Honey beeApismelliferaWorker 141-1 99.1 48 hr LD50 > 100 UGB N.R. N.R. COrthosulfamuron Honey beeApismellifera 4-6 W 141-198.54 48 hr LD50 > 100 UGBN.A. 100 C105CHEMICALCOMMON NAMESPECIES AGEGUIDELINE AISTUDYTIMEDOSETYPETGLTOXVALUETOXLEVEL CLNGLNOELCATEGORYOrthosulfamuron Honey beeApismellifera 4-6 W 14198.54 48 hr LD50 > 109.4 UGBN.A. 109.4 SMonuron Honey beeApismelliferaWorker 141-1 Tech 48 hr LD50 110 UGB N.R. N.R. CLinuron Honey beeApismellifera Adults 141-1 Tech 48 hr LD50 > 120.86 UGB N.R. < 120. CLinuron Honey beeApismellifera Adults 141-1 Tech 48 hr LD50 > 120.86 UGB N.R. < 120. CDiuron Honey beeApismellifera Adult 141-1 Tech 48 hr LD50 > 145.03 UGB N.R. N.R. C

### 106 Appendix C. ECOSAR Output

Orthosulfamuron

SMILES : c2cccc(c2NS(= O)(=O)NC(=O)(Nc1nc(cc( n1)OC)OC))C(=O)N(C)C CHEM : CAS Num: ChemID1: ChemID2: ChemID3: MOL FOR: C16 H20 N6 O6 S1 MOL WT : 424.43 Log Kow: 0.14 (KowWin estimate) Melt Pt: Wat Sol: 79.78 mg/L (WskowWin estimate)

ECOSAR v1.00 Class(es) Found

------------------------------ Amides Sulfonyl Ureas Predicted ECOSAR Class Organism Duration End Pt mg/L (ppm)

=========================== ================== ======== ====== ========== Amides : Fish 96-hr LC50 1608.388 * Amides : Daphnid 48-hr LC50 477.008 * Amides : Green Algae 96-hr EC50 3.070 Amides : Fish ChV 9.508 Amides : Daphnid ChV 6.293 ! Amides : Green Algae ChV 0.709

Sulfonyl Ureas : Daphnid 48-hr LC50 1951.168 * Sulfonyl Ureas : Green Algae 96-hr EC50 0.047 Sulfonyl Ureas : Daphnid ChV 172.049 *! Sulfonyl Ureas : Green Algae ChV 0.012 !

=========================== ================== ======== ====== ========== Neutral Organic SAR : Fish 96-hr LC50 12189.570 * (Baseline Toxicity) : Daphnid 48-hr LC50 5619.408 * : Green Algae 96-hr EC50 1130.721 * : Fish ChV 1205.637 * : Daphnid ChV 373.736 * : Green Algae ChV 291.533 *

Note: * = asterisk designates: Chemical may not be soluble enough to m easure this pred icted effect.

Note: ! = exclamation designates: The toxicity value was determined from a predicted SAR using established acute-to-chronic ratios and ECOSAR regression techniques which are documented in the supporting Technical Reference Manual. When possible, this toxicity value should be considered in a weight of evidence approach.

Amides :

------- No limitations known at this time.

### 107 ECOSAR v1.00 SAR Limitations:

---------------------------- Maximum LogKow: >8.5 (LC50) Maximum LogKow: >8.0 (EC50,ChV) Maximum Mol Wt: 1000

Sulfonyl Ureas :

--------------- For Fish and Daphnid Acute Toxicity Values: If the log Kow of the chemical is greater than 5.0, or if the com pound is solid and the LC50 exceeds the water solubility by 10X, no effects at saturation are predicted for these endpoints.

For Green Algae Acute Toxicity Values : If the log Kow of the chemical is greater than 6.4, or if the compound is solid and the EC50 exceeds the water solubility by 10X, no effects at saturation are predicted for these endpoints.

For All Chronic Toxicity Values: If the log Kow of the chemical is greater than 8.0, or if the compound is solid and the ChV exceeds the water solubility by 10X, no effects at saturation are predicted for these endpoints.

ECOSAR v1.00 SAR Limitations:

---------------------------- Maximum LogKow: 5.0 (LC50) Maximum LogKow: 6.4 (EC50) Maximum LogKow: 8.0 (ChV) Maximum Mol Wt: 1000

Baseline Toxicity SAR Limitations:

--------------------------------- Maximum LogKow: 5.0 (Fish 96-hr LC50; Daphnid LC50) Maximum LogKow: 6.4 (Green Algae EC50) Maximum LogKow: 8.0 (ChV) Maximum Mol Wt: 1000

------------------------------------------------------------------------------ DB amine

SMILES : CN(C)C(=O)c1ccccc1N CHEM : CAS Num: ChemID1: ChemID2: ChemID3: MOL FOR: C9 H12 N2 O1 MOL WT : 164.21 Log Kow: 0.43 (KowWin estimate) Melt Pt: Wat Sol: 2.806E+004 mg/L (WskowWin estimate)

ECOSAR v1.00 Class(es) Found

------------------------------ Anilines (Aromatic Amines) Amides Predicted ECOSAR Class Organism Duration End Pt mg/L (ppm)

### 108 =========================== ================== ======== ====== ========== Anilines (Aromatic Amines) : Fish 96-hr LC50 155.748 Anilines (Aromatic Amines) : Fish 14-day LC50 871.772 Anilines (Aromatic Amines) : Daphnid 48-hr LC50 3.193 Anilines (Aromatic Amines) : Green Algae 96-hr EC50 10.874 Anilines (Aromatic Amines) : Fish ChV 0.949 Anilines (Aromatic Amines) : Daphnid ChV 0.079 Anilines (Aromatic Amines) : Green Algae ChV 7.487

Amides : Fish 96-hr LC50 368.363 Amides : Daphnid 48-hr LC50 120.669 Amides : Green Algae 96-hr EC50 0.987 Amides : Fish ChV 2.178 Amides : Daphnid ChV 1.592 ! Amides : Green Algae ChV 0.274

=========================== ================== ======== ====== ========== Neutral Organic SAR : Fish 96-hr LC50 2691.245 (Baseline Toxicity) : Daphnid 48-hr LC50 1284.607 : Green Algae 96-hr EC50 290.897 : Fish ChV 264.495 : Daphnid ChV 89.899 : Green Algae ChV 79.050

Note: * = asterisk designates: Chemical may not be soluble enough to m easure this pred icted effect.

Note: ! = exclamation designates: The toxicity value was determined from a predicted SAR using established acute-to-chronic ratios and ECOSAR regression techniques which are documented in the supporting Technical Reference Manual. When possible, this toxicity value should be considered in a weight of evidence approach.

Anilines (Aromatic Amines):

-------------------------- For Fish Acute Toxicity Values: 2,3,5,6-Tetrachloroaniline is 19 times more toxic than predicted by this SAR. Tetrabromoaniline may be more toxic than predicted by this SAR as well.

_________________________________________________________________________

DBS Amide

SMILES : CN(C)C(=O)c1ccccc1CS(N)(=O)=O CHEM : CAS Num: ChemID1: ChemID2: ChemID3: MOL FOR: C10 H14 N2 O3 S1 MOL WT : 242.29 Log Kow: -0.63 (KowWin estimate) Melt Pt: Wat Sol: 4414 mg/L (WskowWin estimate)

ECOSAR v1.00 Class(es) Found

------------------------------

### 109 Amides Predicted ECOSAR Class Organism Duration End Pt mg/L (ppm)

=========================== ================== ======== ====== ========== Amides : Fish 96-hr LC50 3754.284 Amides : Daphnid 48-hr LC50 852.446 Amides : Green Algae 96-hr EC50 2.878 Amides : Fish ChV 22.194 Amides : Daphnid ChV 11.245 ! Amides : Green Algae ChV 0.405

=========================== ================== ======== ====== ========== Neutral Organic SAR : Fish 96-hr LC50 31397.006 * (Baseline Toxicity) : Daphnid 48-hr LC50 13182.329 * : Green Algae 96-hr EC50 1931.323 : Fish ChV 3158.930 : Daphnid ChV 764.676 : Green Algae ChV 432.379

Note: * = asterisk designates: Chemical may not be soluble enough to m easure this pred icted effect.

Note: ! = exclamation designates: The toxicity value was determined from a predicted SAR using established acute-to-chronic ratios and ECOSAR regression techniques which are documented in the supporting Technical Reference Manual. When possible, this toxicity value should be considered in a weight of evidence approach.

Amides :

------- No limitations known at this time.

ECOSAR v1.00 SAR Limitations:

---------------------------- Maximum LogKow: >8.5 (LC50) Maximum LogKow: >8.0 (EC50,ChV) Maximum Mol Wt: 1000

Baseline Toxicity SAR Limitations:

--------------------------------- Maximum LogKow: 5.0 (Fish 96-hr LC50; Daphnid LC50) Maximum LogKow: 6.4 (Green Algae EC50) Maximum LogKow: 8.0 (ChV) Maximum Mol Wt: 1000

------------------------------------------------------------------------------ DBS acid

SMILES : CN(C)C(=O)c1ccccc1NS(=O)(=O)O CHEM : CAS Num: ChemID1: ChemID2: ChemID3: MOL FOR: C9 H12 N2 O4 S1 MOL WT : 244.27 Log Kow: -3.35 (KowWin estimate)

### 110 Melt Pt: Wat Sol: 8987 mg/L (WskowWin estimate)

ECOSAR v1.00 Class(es) Found

------------------------------ Amides Predicted ECOSAR Class Organism Duration End Pt mg/L (ppm)

=========================== ================== ======== ====== ========== Amides : Fish 96-hr LC50 5.32e+005 * Amides : Daphnid 48-hr LC50 47315.199 * Amides : Green Algae 96-hr EC50 16.570 Amides : Fish ChV 3147.680 Amides : Daphnid ChV 624.167 ! Amides : Green Algae ChV 0.408

=========================== ================== ======== ====== ========== Neutral Organic SAR : Fish 96-hr LC50 6.29e+006 * (Baseline Toxicity) : Daphnid 48-hr LC50 1.9e+006 * : Green Algae 96-hr EC50 91452.766 * : Fish ChV 6.72e+005 * : Daphnid ChV 68271.930 * : Green Algae ChV 12468.424 *

Note: * = asterisk designates: Chemical may not be soluble enough to m easure this pred icted effect.

Note: ! = exclamation designates: The toxicity value was determined from a predicted SAR using established acute-to-chronic ratios and ECOSAR regression techniques which are documented in the supporting Technical Reference Manual. When possible, this toxicity value should be considered in a weight of evidence approach.

Amides :

------- No limitations known at this time.

ECOSAR v1.00 SAR Limitations:

---------------------------- Maximum LogKow: >8.5 (LC50) Maximum LogKow: >8.0 (EC50,ChV) Maximum Mol Wt: 1000

Baseline Toxicity SAR Limitations:

--------------------------------- Maximum LogKow: 5.0 (Fish 96-hr LC50;

DOP amine SMILES : COc1cc(OC)nc(N)n1 CHEM : CAS Num: ChemID1: ChemID2: ChemID3: MOL FOR: C6 H9 N3 O2 MOL WT : 155.16

### 111 Log Kow: 0.95 (KowWin estimate) Melt Pt: Wat Sol: 1.108E+004 mg/L (WskowWin estimate)

ECOSAR v1.00 Class(es) Found

------------------------------ Anilines (Aromatic Amines) Predicted ECOSAR Class Organism Duration End Pt mg/L (ppm)

=========================== ================== ======== ====== ========== Anilines (Aromatic Amines) : Fish 96-hr LC50 78.845 Anilines (Aromatic Amines) : Fish 14-day LC50 225.619 Anilines (Aromatic Amines) : Daphnid 48-hr LC50 2.376 Anilines (Aromatic Amines) : Green Algae 96-hr EC50 9.172 Anilines (Aromatic Amines) : Fish ChV 0.380 Anilines (Aromatic Amines) : Daphnid ChV 0.050 Anilines (Aromatic Amines) : Green Algae ChV 6.078

=========================== ================== ======== ====== ========== Neutral Organic SAR : Fish 96-hr LC50 922.143 (Baseline Toxicity) : Daphnid 48-hr LC50 468.756 : Green Algae 96-hr EC50 131.427 : Fish ChV 89.591 : Daphnid ChV 35.968 : Green Algae ChV 39.276

Note: * = asterisk designates: Chemical may not be soluble enough to m easure this pred icted effect.

Anilines (Aromatic Amines):

-------------------------- For Fish Acute Toxicity Values: 2,3,5,6-Tetrachloroaniline is 19 times more toxic than predicted by this SAR. Tetrabromoaniline may be more toxic than predicted by this SAR as well.

For Daphnid and Green Algae Toxicity Values: Tetrachloro- and tetrabromaniline may be 20 times toxic than predicted by this SAR.

N-Substituted anilines are less toxi c than predicted by these SARs; for these compounds, Neutral Organic SARs are used.

ECOSAR v1.00 SAR Limitations:

---------------------------- Maximum LogKow: >7.8 (Fish 96-hr LC50, Daphnid 48-h LC50) Maximum LogKow: >3.7 (Fish 14-day LC50) Maximum LogKow: >4 (Green Algae 96-hr EC50 and ChV) Maximum LogKow: >4.3 (Fish ChV) Maximum LogKow: >2.4 (Daphnid ChV) Maximum Mol Wt: 1000

Baseline Toxicity SAR Limitations:

--------------------------------- Maximum LogKow: 5.0 (Fish 96-hr LC50; Daphnid LC50) Maximum LogKow: 6.4 (Green Algae EC50) Maximum LogKow: 8.0 (ChV) Maximum Mol Wt: 1000

### 112 ----------------------------------------------------------------------------- DOP urea

SMILES : CN(C)C(=O)c1ccccc1NS(=O)(=O)O CHEM : CAS Num: ChemID1: ChemID2: ChemID3: MOL FOR: C9 H12 N2 O4 S1 MOL WT : 244.27 Log Kow: -3.35 (KowWin estimate) Melt Pt: Wat Sol: 8987 mg/L (WskowWin estimate)

ECOSAR v1.00 Class(es) Found

------------------------------ Amides Predicted ECOSAR Class Organism Duration End Pt mg/L (ppm)

=========================== ================== ======== ====== ========== Amides : Fish 96-hr LC50 5.32e+005 * Amides : Daphnid 48-hr LC50 47315.199 * Amides : Green Algae 96-hr EC50 16.570 Amides : Fish ChV 3147.680 Amides : Daphnid ChV 624.167 ! Amides : Green Algae ChV 0.408

=========================== ================== ======== ====== ========== Neutral Organic SAR : Fish 96-hr LC50 6.29e+006 * (Baseline Toxicity) : Daphnid 48-hr LC50 1.9e+006 * : Green Algae 96-hr EC50 91452.766 * : Fish ChV 6.72e+005 * : Daphnid ChV 68271.930 * : Green Algae ChV 12468.424 *

Note: * = asterisk designates: Chemical may not be soluble enough to m easure this pred icted effect.

Note: ! = exclamation designates: The toxicity value was determined from a predicted SAR using established acute-to-chronic ratios and ECOSAR regression techniques which are documented in the supporting Technical Reference Manual. When possible, this toxicity value should be considered in a weight of evidence approach.

Amides :

------- No limitations known at this time.

ECOSAR v1.00 SAR Limitations:

---------------------------- Maximum LogKow: >8.5 (LC50) Maximum LogKow: >8.0 (EC50,ChV) Maximum Mol Wt: 1000

Baseline Toxicity SAR Limitations:

### 113 --------------------------------- Maximum LogKow: 5.0 (Fish 96-hr LC50; Daphnid LC50) Maximum LogKow: 6.4 (Green Algae EC50) Maximum LogKow: 8.0 (ChV) Maximum Mol Wt: 1000

------------------------------------------------------------------------------ SMILES : COc1cc(OC )nc(NC(=O)(N))n1 CHEM : CAS Num: ChemID1: ChemID2: ChemID3: MOL FOR: C7 H10 N4 O3 MOL WT : 198.18 Log Kow: 0.58 (KowWin estimate) Melt Pt: Wat Sol: 1.423E+004 mg/L (WskowWin estimate)

ECOSAR v1.00 Class(es) Found

------------------------------ Substituted Ureas Amides Predicted ECOSAR Class Organism Duration End Pt mg/L (ppm)

=========================== ================== ======== ====== ========== Substituted Ureas : Fish 96-hr LC50 612.669 Substituted Ureas : Daphnid 48-hr LC50 1451.215 Substituted Ureas : Green Algae 96-hr EC50 0.147 Substituted Ureas : Fish ChV 8.207 Substituted Ureas : Daphnid ChV 93.220 Substituted Ureas : Green Algae ChV 0.044 !

Amides : Fish 96-hr LC50 337.630 Amides : Daphnid 48-hr LC50 116.527 Amides : Green Algae 96-hr EC50 1.082 Amides : Fish ChV 1.996 Amides : Daphnid ChV 1.537 ! Amides : Green Algae ChV 0.331

=========================== ================== ======== ====== ========== Neutral Organic SAR : Fish 96-hr LC50 2419.702 (Baseline Toxicity) : Daphnid 48-hr LC50 1176.283 : Green Algae 96-hr EC50 283.404 : Fish ChV 237.015 : Daphnid ChV 84.548 : Green Algae ChV 79.168

Note: * = asterisk designates: Chemical may not be soluble enough to m easure this pred icted effect.

Note: ! = exclamation designates: The toxicity value was determined from a predicted SAR using established acute-to-chronic ratios and ECOSAR regression techniques which are documented in the supporting Technical Reference Manual. When possible, this toxicity value should be considered in a weight of evidence approach.

### 114 Substituted Ureas:

----------------- For Fish and Daphnid Acute Toxicity Values: If the log Kow of the chemical is greater than 5.0, or if the com pound is solid and the LC50 exceeds the water solubility by 10X, no effects at saturation are predicted for these endpoints.

For Green Algae Acute Toxicity Values : If the log Kow of the chemical is greater than 6.4, or if the compound is solid and the EC50 exceeds the water solubility by 10X, no effects at saturation are predicted for these endpoints.

For All Chronic Toxicity Values: If the log Kow of the chemical is greater than 8.0, or if the compound is solid and the ChV exceeds the water solubility by 10X, no effects at saturation are predicted for these endpoints.

ECOSAR v1.00 SAR Limitations:

---------------------------- Maximum LogKow: 5.0 (LC50) Maximum LogKow: 6.4 (EC50) Maximum LogKow: 8.0 (ChV) Maximum Mol Wt: 1000

Amides :

------- No limitations known at this time.

ECOSAR v1.00 SAR Limitations:

---------------------------- Maximum LogKow: >8.5 (LC50) Maximum LogKow: >8.0 (EC50,ChV) Maximum Mol Wt: 1000

Baseline Toxicity SAR Limitations:

--------------------------------- Maximum LogKow: 5.0 (Fish 96-hr LC50; Daphnid LC50) Maximum LogKow: 6.4 (Green Algae EC50) Maximum LogKow: 8.0 (ChV) Maximum Mol Wt: 1000

------------------------------------------------------------------------------ O-desmethyl

SMILES : COc2cc(O)nc (NC(=O)NS(=O)(=O)N c1ccccc1C(=O)N(C)C)n2 CHEM : CAS Num: ChemID1: ChemID2: ChemID3: MOL FOR: C15 H18 N6 O6 S1 MOL WT : 410.41 Log Kow: -0.47 (KowWin estimate) Melt Pt: Wat Sol: 328.3 mg/L (WskowWin estimate)

ECOSAR v1.00 Class(es) Found

------------------------------ Phenols

### 115 Amides Sulfonyl Ureas Phenol Amines Predicted ECOSAR Class Organism Duration End Pt mg/L (ppm)

=========================== ================== ======== ====== ========== Phenols : Fish 96-hr LC50 3964.157 * Phenols : Fish 14-day LC50 46190.941 * Phenols : Daphnid 48-hr LC50 541.736 * Phenols : Green Algae 96-hr EC50 3168.796 * Phenols : Fish 30-day ChV 136.513 Phenols : Fish 60-day ChV 0.013 Phenols : Daphnid 21-day ChV 103.471 Phenols : Green Algae ChV 1536.038 * Phenols : Fish (SW) 96-hr LC50 13090.946 * Phenols : Earthworm 14-day LC50 3916.285 * Phenols : Lemna Gibba 7-day EC50 7162.771 *

Amides : Fish 96-hr LC50 4783.883 * Amides : Daphnid 48-hr LC50 1146.478 * Amides : Green Algae 96-hr EC50 4.410 Amides : Fish ChV 28.280 Amides : Daphnid ChV 15.124 ! Amides : Green Algae ChV 0.686

Sulfonyl Ureas : Daphnid 48-hr LC50 5089.483 * Sulfonyl Ureas : Green Algae 96-hr EC50 0.046 Sulfonyl Ureas : Daphnid ChV 433.611 *! Sulfonyl Ureas : Green Algae ChV 0.011 !

Phenol Amines : Fish 96-hr LC50 147.083 Phenol Amines : Daphnid 48-hr LC50 5.923 Phenol Amines : Green Algae 96-hr EC50 60.378 Phenol Amines : Fish ChV 18.055 ! Phenol Amines : Daphnid 21-day ChV 7.175 Phenol Amines : Green Algae ChV 7.803

=========================== ================== ======== ====== ========== Neutral Organic SAR : Fish 96-hr LC50 39219.160 * (Baseline Toxicity) : Daphnid 48-hr LC50 16780.619 * : Green Algae 96-hr EC50 2621.340 * : Fish ChV 3932.327 * : Daphnid ChV 1000.684 * : Green Algae ChV 603.848 *

Note: * = asterisk designates: Chemical may not be soluble enough to m easure this pred icted effect.

Note: ! = exclamation designates: The toxicity value was determined from a predicted SAR using established acute-to-chronic ratios and ECOSAR regression techniques which are documented in the supporting Technical Reference Manual. When possible, this toxicity value should be considered in a weight of evidence approach.

Phenols:

-------

### 116 For All Acute and Chronic Toxicity Values: If the log Kow of the chemical is greater than the value listed below, or if the compound is solid and the LC50, EC50 or ChV exceeds the water solubility by 10X, no effects at saturation are predicted for these endpoints.

ECOSAR v1.00 SAR Limitations:

---------------------------- Maximum LogKow: 7.0 (Fish 96-hr LC50, Daphnid LC50) Maximum LogKow: 6.4 (Fish 14-day LC50, Earthworm, Lemna) Maximum LogKow: 7.0 (Green Algae EC50 Maximum LogKow: 8.0 (ChV) Maximum LogKow: 5.0 (Fish (SW) 96-hr LC50, Mysid) Maximum Mol Wt: 1000

Amides :

------- No limitations known at this time.

ECOSAR v1.00 SAR Limitations:

---------------------------- Maximum LogKow: >8.5 (LC50) Maximum LogKow: >8.0 (EC50,ChV) Maximum Mol Wt: 1000

Sulfonyl Ureas :

--------------- For Fish and Daphnid Acute Toxicity Values: If the log Kow of the chemical is greater than 5.0, or if the com pound is solid and the LC50 exceeds the water solubility by 10X, no effects at saturation are predicted for these endpoints.

For Green Algae Acute Toxicity Values : If the log Kow of the chemical is greater than 6.4, or if the compound is solid and the EC50 exceeds the water solubility by 10X, no effects at saturation are predicted for these endpoints.

For All Chronic Toxicity Values: If the log Kow of the chemical is greater than 8.0, or if the compound is solid and the ChV exceeds the water solubility by 10X, no effects at saturation are predicted for these endpoints.

ECOSAR v1.00 SAR Limitations:

---------------------------- Maximum LogKow: 5.0 (LC50) Maximum LogKow: 6.4 (EC50) Maximum LogKow: 8.0 (ChV) Maximum Mol Wt: 1000

Phenol Amines :

-------------- For All Acute and Chronic Toxicity Values: If the log Kow of the chemical is greater than the value listed below, or if the compound is solid and the LC50, EC50 or ChV exceeds the water solubility by 10X, no effects at saturation are predicted for these endpoints.

ECOSAR v1.00 SAR Limitations:

---------------------------- Maximum LogKow: 5.0 (Fish 96-hr LC50)

### 117 Maximum LogKow: 7.0 (Daphnid LC50) Maximum LogKow: 6.4 (Green Algae EC50 Maximum LogKow: 8.0 (ChV) Maximum Mol Wt: 1000

Baseline Toxicity SAR Limitations:

--------------------------------- Maximum LogKow: 5.0 (Fish 96-hr LC50; Daphnid LC50) Maximum LogKow: 6.4 (Green Algae EC50) Maximum LogKow: 8.0 (ChV) Maximum Mol Wt: 1000

------------------------------------------------------------------------------

o -desmethyl DOP urea

SMILES : COc1cc(O)nc(NC(=O)(N))n1 CHEM : CAS Num: ChemID1: ChemID2: ChemID3: MOL FOR: C6 H8 N4 O3 MOL WT : 184.16 Log Kow: -0.04 (KowWin estimate) Melt Pt: Wat Sol: 2757 mg/L (WskowWin estimate)

ECOSAR v1.00 Class(es) Found

------------------------------ Phenols Substituted Ureas Amides Phenol Amines Predicted ECOSAR Class Organism Duration End Pt mg/L (ppm)

=========================== ================== ======== ====== ========== Phenols : Fish 96-hr LC50 848.565 Phenols : Fish 14-day LC50 8576.770 * Phenols : Daphnid 48-hr LC50 137.081 Phenols : Green Algae 96-hr EC50 768.347 Phenols : Fish 30-day ChV 33.464 Phenols : Fish 60-day ChV 0.006 Phenols : Daphnid 21-day ChV 26.164 Phenols : Green Algae ChV 370.382 Phenols : Fish (SW) 96-hr LC50 2146.550 Phenols : Earthworm 14-day LC50 1162.351 Phenols : Lemna Gibba 7-day EC50 1336.458

Substituted Ureas : Fish 96-hr LC50 1601.934 Substituted Ureas : Daphnid 48-hr LC50 4283.929 * Substituted Ureas : Green Algae 96-hr EC50 0.147 Substituted Ureas : Fish ChV 20.161 Substituted Ureas : Daphnid ChV 241.913 Substituted Ureas : Green Algae ChV 0.047 !

Amides : Fish 96-hr LC50 965.040

### 118 Amides : Daphnid 48-hr LC50 269.141 Amides : Green Algae 96-hr EC50 1.493 Amides : Fish ChV 5.705 Amides : Daphnid ChV 3.550 ! Amides : Green Algae ChV 0.308

Phenol Amines : Fish 96-hr LC50 44.406 Phenol Amines : Daphnid 48-hr LC50 2.257 Phenol Amines : Green Algae 96-hr EC50 18.491 Phenol Amines : Fish ChV 4.509 ! Phenol Amines : Daphnid 21-day ChV 2.014 Phenol Amines : Green Algae ChV 2.550

=========================== ================== ======== ====== ========== Neutral Organic SAR : Fish 96-hr LC50 7481.463 * (Baseline Toxicity) : Daphnid 48-hr LC50 3375.544 * : Green Algae 96-hr EC50 631.377 : Fish ChV 742.888 : Daphnid ChV 217.544 : Green Algae ChV 157.582

Note: * = asterisk designates: Chemical may not be soluble enough to m easure this pred icted effect.

Note: ! = exclamation designates: The toxicity value was determined from a predicted SAR using established acute-to-chronic ratios and ECOSAR regression techniques which are documented in the supporting Technical Reference Manual. When possible, this toxicity value should be considered in a weight of evidence approach.

Phenols:

------- For All Acute and Chronic Toxicity Values: If the log Kow of the chemical is greater than the value listed below, or if the compound is solid and the LC50, EC50 or ChV exceeds the water solubility by 10X, no effects at saturation are predicted for these endpoints.

ECOSAR v1.00 SAR Limitations:

---------------------------- Maximum LogKow: 7.0 (Fish 96-hr LC50, Daphnid LC50) Maximum LogKow: 6.4 (Fish 14-day LC50, Earthworm, Lemna) Maximum LogKow: 7.0 (Green Algae EC50 Maximum LogKow: 8.0 (ChV) Maximum LogKow: 5.0 (Fish (SW) 96-hr LC50, Mysid) Maximum Mol Wt: 1000

Substituted Ureas:

----------------- For Fish and Daphnid Acute Toxicity Values: If the log Kow of the chemical is greater than 5.0, or if the com pound is solid and the LC50 exceeds the water solubility by 10X, no effects at saturation are predicted for these endpoints.

For Green Algae Acute Toxicity Values : If the log Kow of the chemical is greater than 6.4, or if the compound is solid and the EC50 exceeds the water solubility by 10X, no effects at saturation are predicted for these endpoints.

### 119 For All Chronic Toxicity Values: If the log Kow of the chemical is greater than 8.0, or if the compound is solid and the ChV exceeds the water solubility by 10X, no effects at saturation are predicted for these endpoints.

ECOSAR v1.00 SAR Limitations:

---------------------------- Maximum LogKow: 5.0 (LC50) Maximum LogKow: 6.4 (EC50) Maximum LogKow: 8.0 (ChV) Maximum Mol Wt: 1000

Amides :

------- No limitations known at this time.

ECOSAR v1.00 SAR Limitations:

---------------------------- Maximum LogKow: >8.5 (LC50) Maximum LogKow: >8.0 (EC50,ChV) Maximum Mol Wt: 1000

Phenol Amines :

-------------- For All Acute and Chronic Toxicity Values: If the log Kow of the chemical is greater than the value listed below, or if the compound is solid and the LC50, EC50 or ChV exceeds the water solubility by 10X, no effects at saturation are predicted for these endpoints.

ECOSAR v1.00 SAR Limitations:

---------------------------- Maximum LogKow: 5.0 (Fish 96-hr LC50) Maximum LogKow: 7.0 (Daphnid LC50) Maximum LogKow: 6.4 (Green Algae EC50 Maximum LogKow: 8.0 (ChV) Maximum Mol Wt: 1000

Baseline Toxicity SAR Limitations:

--------------------------------- Maximum LogKow: 5.0 (Fish 96-hr LC50; Daphnid LC50) Maximum LogKow: 6.4 (Green Algae EC50) Maximum LogKow: 8.0 (ChV) Maximum Mol Wt: 1000

### 120 Appendix D. Ecological Toxicity Summary for Aquatic and Terrestrial Organisms from Orthosulfamuron

Exposure Scenario Surrogate Species Acute Toxicity

-- Chronic Toxicity Citation
MRID Acute Toxicity Classification

Birds 1

Acute (Dose-based) Mallard duck ( Anas platyrhynchos )

and
Bobwhite Quail ( Colinus virginianus ) LD 50 >1960 mg a.i./kg Single oral dose 46260107 (Acceptable) Slightly Toxic

Subacute (Dietary-based) Mallard duck LC 50 >4790 mg a.i./kg diet 8-day Dietary 46219040 (Acceptable)

Chronic Mallard duck

and Bobwhite Quail NOAEC = 1280 mg a.i./kg/day Avian reproduction 46578949 (Duck-Acceptable) 46578950 (Quail-Acceptable) --

Mammals

Acute

Laboratory rat ( Rattus norvegicus ) LD 50 >5000 mg a.i./kg Single oral dose 46219019 (Acceptable) Practically Non-toxic

Chronic NOAEC (kidney lesions) = 88.6 mg a.i./kg/day Two-Generation 46219033 (Acceptable) --

Chronic NOAEL (changes in body wt gain, hepatotox, nephrotox) = 5 mg/kg/day Chronic Toxicity MRID 46578913 --

Insects

Acute (contact) Honey bee ( Apis mellifera L. ) LD 50 >100 ug a.i./bee 48-Hour 46219046 (Acceptable) Practically Non-toxic Acute (oral) LD 50 >109.4 ug a.i./bee 48-Hour 46219046 (Supplemental)
Freshwater fish 2

Acute Rainbow Trout ( Oncorhynchus mykiss ) LC 50 >122 mg a.i./L 96-Hour 46219042 (Acceptable) Practically Non-toxic

Bluegill Sunfish ( Lepomis macrochirus) LC 50 >142 mg a.i./L 96-Hour 46219043 (Acceptable) Practically Non-toxic

Chronic Fathead Minnow ( Pimephales promelas ) NOAEC (dry wt) = 6.1 mg a.i./L Early Life Stage 46578953 (Acceptable) --

Freshwater Invertebrates

Acute Water Flea ( Daphnia magna ) EC 50 (mortality/immobility) > 97.3 mg a.i./L 48-Hour 46219044 (Acceptable) Practically Non-toxic

Acute Crayfish ( Procambarus clarkii ) EC 50 >129 mg a.i./L

---- NOAEC = 129 mg a.i./L 96-Hour 46578955 (Supplemental) Practically Non-toxic

Chronic Water Flea ( Daphnia magna ) NOAEC (total length) = 6.5 mg a.i./L 21-Day 46578956 (Acceptable) --

### 121 Exposure Scenario Surrogate Species Acute Toxicity

-- Chronic Toxicity Citation
MRID Acute Toxicity Classification

Estuarine/Marine Fish

Acute Sheepshead Minnow ( Cyprindon varigatus ) LC 50 >123 mg a.i./L 96-Hour 46578951 (acceptable) Practically Non-toxic

Chronic *No studies available*

Estuarine/Marine Invertebrates

Acute Eastern Oyster ( Crassostrea

virginica ) EC 50 >97 mg a.i./L 96-Hour 46578957 (Acceptable) Slightly Toxic

Acute Mysid Shrimp ( Americamysis bahia ) LC 50 >122 mg a.i./L 96-Hour 46578952 (Acceptable) Practically Non-toxic

Chronic Mysid Shrimp NOAEC = 27 mg a.i./L 29 Days 46578954 (Supplemental) --

Terrestrial Plants

Monocot Rice ( Oryza sativa ) EC 25 (dry wt) = 0.078 lb a.i./A

---- NOAEC = 0.0436 lb a.i./A Seedling Emergence 46578941 (Acceptable) NA

Onion ( Allium cepa 

### ) EC 25 (dry wt)=0.0048 lb a.i./A

---- NOAEC = 0.00169 lbs a.i./A Vegetative Vigor 46578942 (Supplemental) NA

Dicot Radish ( Raphanus sativus ) EC 25 =0.040 lb a.i./A

---- NOAEC = 0.015 lb a.i./A Seedling Emergence 46578941 (Acceptable) NA

Carrot ( Daucus carota ) EC 25 = 0.00012 lb a.i./A EC 05 = 0.000027 lb a.i./A

---- NOAEC < 0.0000664 Vegetative Vigor 46578942 (Supplemental) NA

Aquatic Plants

Aquatic vascular Plants Duckweed ( Lemna gibba ) EC 50 (frond number) =0.0007 mg a.i./L

------- NOAEC = 0.00026 mg a.i./L 7-Day Study 46578939 (Acceptable) NA

EC50 (frond number) = 0.00075 mg a.i./L

---- NOAEC = 0.00022 mg a.i./L 7-Day Study 46578940 (Acceptable) NA

Aquatic Nonvascular plants 3 Freshwater Diatom Navicula pelliculosa EC 50 (biomass) = 0.8 mg a.i./L

----- NOAEC = 0.28 mg a.i./L 96-Hour 46578935 (Supplemental) NA

Marine Algae 3 Marine Diatom ( Skeletonema

costatum ) EC 50 (biomass) = 0.08 mg a.i./L

------- NOAEC = 0.021 mg a.i./L 46578936 (Supplemental) NA

1 Birds represent surrogates for terrest rial-phase amphibians and reptiles.

2 Freshwater fish may be surroga tes for aquatic-phase amphibians.

3 Test material was IR5878 50WG with 49.96% orthosulfamuron.

### 122 Appendix E. Results from Screening Imbibition Program (SIP) and the Screening Tool for Inhalation Risk Assessment (STIR)

The S creening I mbibition P rogram (SIP v.1.0, Released June 15, 2010) was used to calculate an upper bound estimate of exposure using orthosulfa muron’s solubility (38,900 mg/L, pH 8.5 at 20 o 

### C, MRID 44621909), the most sensitive acute and chronic avian toxicity endpoints (Bobwhite Quail with LD 50 

### >1960 mg/kg-bw and mallard duck NOAEC = 1280 mg/kg-diet, respectively) and the most sensitive acute and chro nic mammalian toxicity endpoints (Rat LD 50 

### >5000 mg/kgbw and NOAEL = 5 mg/kg-bw or 100 mg/kg-diet, resp ectively). Based on the output, exposure through drinking water alone is po tential acute and chronic risk to small birds and a potential chronic risk to small mammals. Although, due to the use of the non-definitive acute values where no mortality was observed at those reported le vels, the potential for acute risk is expected to be quite conservative. Resu lts from SIP are shown below.

Inhalation is another po tential exposure route for terrestria l vertebrates. Based on the vapor pressure of orthosulfamuron (8.37 x 10 -7 

### Torr at 20 o 

### C; MRID 46219010), a semivolatile compound from dry nonadsorbing surfaces and non-vol atile from water and moist surfaces, and therefore risk from inhalation is not expected. The 4-hr LC 50 

### inhalation study using rats was greater than 2.19 mg/L (MRID 46219021) (U SEPA, 2007, D319264). The STIR model (Screening Tool for Inhalation Risk) was used to evaluate inhalation risk to birds. The nondefinitive acute oral values for both birds and mammals were used in the model. Based on STIR, risk to birds from inhalation alone is not expected. Results from STIR are shown below.

### 123 SIP Version 1.0. August, 19, 2010

Results From STIR Version 1.0, November 23, 2010

### 124 

## Welcome to the EFED Screening Tool for Inhalation Risk
This tool is designed to provide the risk assessor with a rapid method for determining the potential significance of the inhalation exposure route to birds and mammals in a risk assessment.



## Input

Application and Chemical Information
Enter Chemical Name Orthosulfamuron
Enter Chemical Use Rice Is the Application a Spray? (enter y or n) y If Spray What Type (enter ground or air) air Enter Chemical Molecular Weight (g/mole) 424.4 Enter Chemical Vapor Pressure (mmHg) 8.37E-07 Enter Application Rate (lb a.i./acre) 0.067

Toxicity Properties

Bird Enter Lowest Bird Oral LD 50 (mg/kg bw) 1960 Enter Mineau Scaling Factor 1.15 Enter Tested Bird Weight (kg) 0.178
Mammal Enter Lowest Rat Oral LD 50 (mg/kg bw) 5000
Enter Lowest Rat Inhalation LC 50 (mg/L) 2.19 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 ) 1.91E-02 Maximum 1-hour Vapor Inhalation Dose (mg/kg) 2.40E-03 Adjusted Inhalation LD 50 4.79E+00 Ratio of Vapor Dose to Adjusted Inhalation LD 50 5.02E-04 Exposure not Likely Significant Maximum Post-treatment Spray Inhalation Dose (mg/kg) 6.44E-03 Ratio of Droplet Inhalation Dose to Adjusted Inhalation LD 50 1.34E-03 Exposure not Likely Significant

Results Mammalian (0.015 kg )
Maximum Vapor Concentration in Air at Saturation (mg/m 3 ) 1.91E-02 Maximum 1-hour Vapor Inhalation Dose (mg/kg) 3.02E-03 Adjusted Inhalation LD 50 1.30E+02 Ratio of Vapor Dose to Adjusted Inhalation LD 50 2.32E-05 Exposure not Likely Significant Maximum Post-treatment Spray Inhalation Dose (mg/kg) 8.09E-03 Ratio of Droplet Inhalation Dose to Adjusted Inhalation LD 50 6.21E-05 Exposure not Likely Significant **NOTE**: When entering values, pres s in order to update linked cells.

### 125 Appendix F. Preliminary Estimated Enviro nmental Concentration for the Parent and Degradates Using the Tier I Rice Model (version 1, May 8, 2007).

Tier 1 Rice Model - Signed May 8, 2007

Cw = mai / 0.00105 + 0.00013 Kd
Cw = mai / 0.00105 + 0.0000013 KOC
Kd = 0.01 KOC

Where: Cw = water concentration [μg/L] Mai mass applied per unit ara [kg/ha] Kd = water-sdiment patitioning coefficient [L/kg] KOC = organic carbon partitioning coeficient [L/kg]

Conversion f Application Rate from lbs a.i./acre to kg a.i./hectare 1 kg=2.205 lbs
1 hectare = 2.471 acres

application rate in kg a.i./hectare = lbs ai/acre x (1 kg/2.205 lbs) x (2.471 acre/1 hectare

Concentration Changes over time were calculated using the following equation: Cw, t = Cw-initial x exp (-kt)

Where:
Cw=Concentration in water at time t or the initial concentration in water exp=base e k=single first order rate constant for aerobic aquatic metabolism in 1/days t=time (days)

Table F1. Concentrations Estimated For Parent

App Rate (lbs a.i./acre) App Rate (kg a.i./hectare) Number of App App Interval Kd 1 Concentration of Orthosulfamuron in

μ g/L 2

Peak 21-day Average 60-day Average Annual Average

0.067 0.07508254 1 NA 1.98 57 37 34 9

0.067 0.07508254 1 NA 20.68 20 17 12 3

App=application; NA=not applicable
1 Kd was used in calculations because the KO C calculation is based on a conversion from Kd. 2 The rate constant used to calculate reductions in co ncentration over time was the average of the rate constants in the California and Arkansas sediments (c ombined values) in the aerobic aquatic metabolism study (MRID 4621907). The combined rate consta nt for California was 0.024 and the combined rate constant for Arkansas was 0.014 resu lting in an average value of 0.019.126Preliminary Estimate of Exposure to DegradatesConcentrations of parent were converted to potential concentrations of degradates using the following equation:Degradate EEC=ObservedDegradateAmountMaximumuronOrthosulamofWeightMolecularDegradateofWeightMolecularin waterparentofionconcentratEstimated××Example Calculation for DOP urea = 57 μg/L ×155.16÷424.4 × 0.47 = 10 μg/LNotes on Analysis Shown in Table F2.‐DB amine and DOP amine were detected near 1% applied radioactivity in the aerobic metabolism study. See MRID, it is notdiscussed well in DER. This 1% was combined with the maximumamount of unextracted residuesobserved in all aerobic aquaticmetabolism test systems.‐DOP urea was detected at a maximum in the Arkansas pyramidine labeled system. Residues were combined with the maximumamount of unextracted residues observed in that study‐Toxicity Values Were Estimated In ECOSAR. For the ureas, chronic values are shown based on values for the o-desmethyl DOPurea and DOP urea.‐Reliable decline curves could notbe determined. For DOP amine, residues increased and decreased over time and the changesmay have been due to variability in theanalytical method. DB amine was detectedat the maximum amount at the final samplinginterval. DOP urea was detected at the maximumamount near or at thefinal sampling interval.127TableF2.EstimatedEECsforOrthosulfamuronandDegradateswithUseonRice.CompoundMolecularWeight(g/mole)MolecularWeightRatioMaximumObservedinAerobicAquaticStudyEEC(ug/L)FishChronicValueDaphnidChronicValueOrthosulfamuron424.415761006500DBamine164.210.390.010.294979DBamine+unextractedresidues164.210.390.34794979DOPamine198.210.470.010.338050DOPamine+unextractedresidues198.210.470.34938050DOPurea155.160.370.47101996615372010DOPurea+O‐desmethylDOPurea155.160.370.5101996615372010DOPurea+‐desmethylDOPurea+unextractedresidues155.160.370.72151996615372010EEC=EECforparentxMWratioxMaximumobservedinAerobicAquaticStudyMolecularWeightRatio=Molecularweightoftransformationproductdividedbymolecularweightofparent.

### 128 

## Appendix G: Example T-Rex Input and Output for Orthosulfamuron.

Table X. Upper Bound Ke naga, Chronic Avian Dietar y Based Risk Quotients

NOAEC (ppm) EECs and RQs

Short Grass Tall Grass Broadleaf Plants/ Small Insects Fruits/Pods/ Seeds/ Large Insects

EEC RQ EEC RQ EEC RQ EEC RQ

0 16.08 ##### 7.37 ##### 9.05 #DIV/0! 1.01 #####
Size class not used for dietary risk quotients

Table X. Upper Bound Kenaga, Acute Ma mmalian Dose-Based Risk Quotients

Size Class (grams) Adjusted LD50 EECs and RQs

Short Grass Tall Grass Broadleaf Plants/ Small Insects Fruits/Pods/ Seeds/ Large Insects Granivore

EEC RQ EEC RQ EEC RQ EEC RQ EEC RQ
15 10989.15 15.33 0.00 7.03 0.00 8.62 0.00 0.96 0.00 0.21 0.00
35 8891.40 10.60 0.00 4.86 0.00 5.96 0.00 0.66 0.00 0.15 0.00
1000 3845.80 2.46 0.00 1.13 0.00 1.38 0.00 0.15 0.00 0.03 0.00

Table X. Upper Bound Kenaga, Acute Ma mmalian Dietary Based Risk Quotients

LC50 (ppm) EECs and RQs

Short Grass Tall Grass Broadleaf Plants/ Small Insects Fruits/Pods/ Seeds/ Large Insects

EEC RQ EEC RQ EEC RQ EEC RQ

0 16.08 ##### 7.37 ##### 9.05 #DIV/0! 1.01 #####

Size class not used for dietary risk quotients

Table X. Upper Bound Ke naga, Chronic Mammalian Diet ary Based Risk Quotients

NOAEC (ppm) EECs and RQs

Short Grass Tall Grass Broadleaf Plants/ Small Insects Fruits/Pods/ Seeds/ Large Insects

### 129 EEC RQ EEC RQ EEC RQ EEC RQ
100 16.08 0.16 7.37 0.07 9.05 0.09 1.01 0.01 Size class not used for dietary risk quotients

Table X. Upper Bound Ke naga, Chronic Mammalian Dose -Based Risk Quotients

Size Class (grams) Adjusted NOAEL EECs and RQs

Short Grass Tall Grass Broadleaf Plants/ Small Insects Fruits/Pods/ Seeds/ Large Insects Granivore

EEC RQ EEC RQ EEC RQ EEC RQ EEC RQ
15 10.99 15.33 1.40 7.03 0.64 8.62 0.78 0.96 0.09 0.21 0.02
35 8.89 10.60 1.19 4.86 0.55 5.96 0.67 0.66 0.07 0.15 0.02
1000 3.85 2.46 0.64 1.13 0.29 1.38 0.36 0.15 0.04 0.03 0.01



### T-Rex can be found at: http://www.epa.gov/o ppefed1/models/terrestrial/trex_usersguide.htm

### 130 

## Appendix H: Example Terrplant (v. 1.2.2) Input and Output for Orthosulfamuron.

TerrPlant v. 1.2.2 Green values signify user inputs (Tables 1, 2 and 4). Input and output guidance is in popups indicated by red arrows.

Table 1. Chemical Identity.

Chemical Name Orthosulfamuron PC code 108209

Use Rice Application Method Aerial

Application Form Spray Solubility in Water (pp m ) 38900

Table 2. Input parameters used to derive EECs.
Input Parameter Symbol Value Units Application Rate A 0.067 y

Incorporation I 1 none Runoff Fraction R 0.05 none

Drift Fraction D 0.05 none

Table 3. EECs for Orthosulfamuron. Units in y.
Description Equation EEC Runoff to dry areas (A/I)*R 0.00335 Runoff to semi-aquatic areas (A/I)*R*10 0.0335 Spray drift A*D 0.00335 Total for dry areas ((A/I)*R)+(A*D) 0.0067 Total for semi-aquatic areas ((A/I)*R*10)+(A*D) 0.03685

Table 4. Plant survival and growth data used for RQ derivation. Units are in y. Seedling Emergence Vegetative Vigor Plant type EC 25 NOAEC EC 25 NOAEC

Monocot 0.048 0.00169 0.078 0.0436

Dicot 0.04 0.015 0.00012 0.000027

Table 5. RQ values for plants in dry and semi-aquatic areas exposed to Orthosulfamuron through runoff and/or spray drift.*
Plant Type Listed Status Dry Semi-Aquatic Spray Drift

Monocot non-listed 0.14 0.77 <0.1
Monocot listed 3.96 21.80 1.98

Dicot non-listed 0.17 0.92 27.92
Dicot listed 0.45 2.46 124.07 *If RQ > 1.0, the LOC is exceeded, resulting in potential for risk to that plant group.

### 131 Appendix I. List of Label Statements Rele vant to the Environmental Risk Assessment.

EPA Registration Number 80289-13 Before applying...water levels must be drained or the water level lowered to allow exposure of the weed leaf surface for maximum uptake of the product by leaves. It is recommended that the field be drained or the water level lowered the da y before the application. If the field cannot be drained before application, the wate r level must be reduced so that at least 70% of the weed leaf surface area is above the floodwat er. Bring the field to nor mal flood-level 24-48 hours after application.

• It is essential that rice be flushed after a foliar application to maximize root absorption resulting in commercially acceptable weed control.

• Nozzle set must use a coarse spray qua lity category per ASAE S572 Standard

• If endangered plant species occur in proxim ity of the application site, the following mitigation measure is required to avoid adverse nontarget effects: Leave untreated downwind buffer zones of 25 f eet for ground applications or 200 feet for aerial applications.

To determine whether your county has an e ndangered terrestrial plant species, consult http://www.epa.gov/espp/use-map.htm . Endangered Species Bulletins may also be obtained from state or county extension offices or stat e pesticide agencies. If the bulletin is not available for your specific area, check with the a ppropriate local state ag ency to determine if known populations or terrestrial endangered pl ants occur in the area to be treated.

• Do not use STRADA XT on sand and loamy sand soils.

• Do not use treated rice fields for the aquacult ure or edible fish and crustacean (crayfish).

• Do not use water from rice cul tivation after a STRADA XT app lication to irri gate any crop other than rice.

• In Arkansas, STRADA XT must not be applied in an area from one mile west of Highway #1 to one mile east of Highway#163 from the Crai gheadPoinsett County line to the CrossPoinsett County line. Furthermor e, no aerial application is allowed in the area of Poinsett County one mile west of Highway#1 to two m iles west of Highway#1 and one mile east of Highway#163 to Ditch #10, from the Craighead-Poinsett County line to the Cross-Poinsett county line.

EPA Registration Number 80289-6

• Do not apply STRADA CA to the same field in the same growing season that an application of STRADA GR has been applied.

EPA Registration Number 80289-5

• Before applying STRADA CA to water seeded ri ce, water level in the rice field must be

### 132 drained or lowered to allow exposure of the weed leaf surface for maximum uptake of the product by the leaves. It is recommended that the field be drained or the water level be lowered the day before applicat ion. If the field cannot be drained before application, the water level must be reduced so that at least 70 % of the weed leaf surf ace area is above the floodwater. Bring the fiel d to normal flood level 24-48 hours after application.

• The distance between the outer most nozzl es on the boom must not exceed 70% of the wingspan or fixed-wing aircraft or 80% of the helicopter rotor width

• Nozzle set up must use a coarse spray quality category per ASAE S-572 Standard

• If endangered plant species occur in proxim ity of the application site, the following mitigation measure is required to avoid adverse nontarget effects: Leave untreated downwind buffer zones of 25 f eet for ground applications or 200 feet for aerial applications.

To determine whether your county has an e ndangered terrestrial plant species, consult http://www.epa.gov/espp/use-map.htm . Endangered Species Bulletins may also be obtained from state or county extension offices or stat e pesticide agencies. If the bulletin is not available for your specific area, check with the a ppropriate local state ag ency to determine if known populations or terrestrial endangered pl ants occur in the area to be treated.

• Application is not allowed when wind speeds ex ceed 10 mph due to risk of direct drift to non-target sensitive crops or locations.

EPA Registration Number MO080002

• The spray boom height may not exceed 15 feet

• Do not make more than 1 application or apply more than 2.1 ounces of STRADA WG (equivalent to 0.067 lb a.i./A) during the growing season in bot h the first and ratoon crops combined.

EPA Registration Number AR-08-0012

• Do not apply where runoff or irrigation water may flow directly onto agricultural land other than rice fields.

• Do not make more than 1 application or apply more than 2.1 ounces of STRADA WG (equivalent to 0.067 lb a.i./A) during the growing season in bot h the first and ratoon crops combined.

EPA Registration Number LA-08-0007

• Do not apply where runoff or irrigation water may flow directly onto agricultural land other than rice fields.

• Do not make more than 1 application or apply more than 2.1 ounces of STRADA WG (equivalent to 0.067 lb a.i./A) during the growing season in bot h the first and ratoon crops

### 133 combined.

EPA Registration Number TX080007

• Do not apply where runoff or irrigation water may flow directly onto agricultural land other than rice fields.

• Do not make more than 1 application or apply more than 2.1 ounces of STRADA WG (equivalent to 0.067 lb a.i./A) during the growing season in bot h the first and ratoon crops combined.

### 134 Appendix J. Identification of Transforma tion Products and Listing of the Maximum Amounts Observed in Fate Studies.

Table J1. Structures of Orthosulfamuro n and Its Environmental Transformation Products.
Code Name/ Synonym/
Chemical Name/ Formula/MW/ SMILES Chemical Structure

Orthosulfamuron, IR5878, S3, H3

IUPAC: 1-(4,6-Dimethoxypyrimidin-2-yl)-3-[2- (dimethylcarbamoyl)phenylsulfamoyl]urea.

CAS: 2-[[[[[(4,6-Dimethoxy-2- pyrimidinyl)amino]carbonyl]amino]sulfonyl]amino]- N,N-dimethylbenzamide

CAS No.: 213464-77-8 Formula: C 16 H 2 ON 6 O 6 S MW: 424.4 g/mol SMILES: CN(C(=O)c1ccccc1NS(=O)(= O)NC(=O)Nc1nc(cc(n1)O C)OC)C

DBS acid, IR7863, S1, H1

IUPAC: (2-Dimethylcarbamoylphenyl)sulfamic acid

CAS: Sodium (2-dimethylcarbamoylphenyl)sulfamate

Other: 2-Sulfamino-N,N-dimethylbenzamide

CAS No.: Formula: C 9 H 12 N 2 SO 4 MW: 244.28g/mol

SMILES: CN(C)C(=O)c1ccccc1NS(=O)(=O)O

DB amine, S4, H4

IUPAC: (2-2-Amino-N,N-dimethylbenzamide

Formula: C 9 H 12 N 2 O MW: 164.21 g/mol

SMILES: CN(C)C(=O)c1ccccc1N
DOP amine, S13, H6

IUPAC: 4,6-Dimethoxypyrimidin-2-yl amine 2-Amino-4,6-dimethoxypyrimidine N

O NH S O O

NH O

NH

N N O

O



### N

NH S O

O O

OH



### N

NH 2 O



## N O

### 135 Code Name/ Synonym/
Chemical Name/ Formula/MW/ SMILES Chemical Structure

Formula: C 7 H 10 N 4 O 3 MW: 198.21

SMILES: COc1cc(OC)nc(N)n1 DOP urea, IR7825, S12, H5

IUPAC: N-(4,6-Dimethoxypyrimidin-2-yl)-urea

CAS : 4,6-Dimethoxy-2-pyrimidinyl urea

Formula: C 6 H 9 N 3 O 2 MW: 155.16 SMILES: COc1cc(OC)nc(NC(N)=O)n1

DBS amide, S2, H2

Other: 2-Sulfamoylamino-N,N-dimethylbenzamide

Formula: C 9 H 13 N 3 SO 3 MW: 243.28 g/mole

SMILES: CN(C)C(=O)c1ccccc1CS(N)(=O)=O

O-desmethyl IR5878, O-des methyl orthosulfamuron, IR8181, S9

IUPAC: 1-(4-Hydroxy-6-methoxypyrimidin-2-yl)-3-[2- (2-dimethylcarbamoyl)phenylsulfamoyl]urea

CAS: 1-[2(Dimethylcarbamoyl)phenylsulfamyl]-3-(4- hydroxy-6-methoxypyrimidin-2-yl)urea

SMILES: COc2cc(O)nc(NC(=O)NS(= O)(=O)Nc1ccccc1C(=O)N(C )C)n2

S11 (multiple unresolved compounds)

S5 (multiple unresolved compounds)

o-desmethyl DOP urea, S15

MW: 184.16 SMILES: COc1cc(O)nc(NC(N)=O)n1

S6 

### N 2 H NH N N O

O O

N

NH S NH 2 O

O O

N

NH S NH NH N N OH

O O O

O O

N H O

H 2 N N

N O OH

### 136 Code Name/ Synonym/
Chemical Name/ Formula/MW/ SMILES Chemical Structure

S8

IR8181
S16

S7 Abbreviations: nd = not detected; AR =applied radioactivity; MW =molecular weight.



### Table J2. Structures of Orthosulfamuro n and Its Environmental Transformation Products. Full chemical names are provided in Table J1.

Common Name or Code Name Study Type MRID Max %AR or Conc. (sampling interval) Final %AR or Conc. (sampling interval) Descriptive Information
for Value

Orthosulfamuron, IR5878, S3, H3

Hydrolysis 46219015 33 ( 37 days) pH 7, 25 o C 56 (176 days) pH 9, 25 o C
nd (5 days) pH 4, 50 o C
18 (5 days) pH 7, 50 o C 72 (5 days) pH 9, 50 o C

Hydrolysis 46219016 15 (1 hr) 1 hr, pH 4, 50 o C
27 (52 hrs) 52 hrs, pH 7, 50 o C

33 (13 days) 13 days, pH 9, 50 o C Aqueous photolysis 46588509 95 (7 days)

Anaerobic Aquatic 46578967 22 (180 days) AR pyr
19 (180 days) AR phe label 7 (180 days) CA pyr label

Aquatic Field Dissipation 46578985 0.083 mg/kg (0day) nd (123 day) AR soil
0.171 mg/kg (3 day) <0.005 mg/kg (60 day) AR sediment 0.017 mg/L (3 day) <0.005 (22 day) AR water
0.103 mg/kg (0 day) <0.005 mg/kg (194 day) CA Soil
0.056 mg/kg (3 day) nd (60 day) CA sediment
DBS acid, IR7863, S1, H1 Hydrolysis 46219015 58 ( 37 days) 58 ( 37 days) pH 7, 25 o C 23 (176 days) 23 (176 days) pH 9, 25 o C 86 (5 days) 86 (5 days) pH 4, 50 o C 66 (5 days) 66 (5 days) pH 7, 50 o C 12 (5 days) 12 (5 days) pH 9, 50 o C

Aerobic Aquatic 46219017 54 (90 day) 54 (90 days) AR phe label 61 (61 days) 61 (61 days) CA phe label

Anaerobic aquatic 46578967 12 (100 days) 9 (180 days) AR phe label 39 (150 days) 39 (150 days) CA pyr label Aquatic field 46578985 0.047 mg/kg(7 days) nd (550 days) AR soil

### 137 Common Name or Code Name Study Type MRID Max %AR or Conc. (sampling interval) Final %AR or Conc. (sampling interval) Descriptive Information
for Value

dissipation 0.065 mg/kg (7 days) nd (60 days) AR sediment 0.011 mg/L (15 days) <0.005 mg/L (60 days) AR water <0.02 mg/kg (7 days) nd (553 days) CA soil <0.02 mg/kg (7 days) nd (60 days) CA sediment <0.005 mg/L (15 days) nd (60 days) CA water DB amine, S4, H4

Hydrolysis 46219015 2 (37 days) 2 (37 days) pH 7, 25 o C 13 (176 days) 13 (176 days) pH 9, 25 o C 13 (5 days) 13 (5 days) pH 4, 50 o C 11 (5 days) 11 (5 days) pH 7, 50 o C 6 (5 days) 6 (5 days) pH 9, 50 o C

Aerobic aquatic 46219017 <1 (90 days) <1 (90 days) AR 1 (90 days) 1 (90 days) CA

Anaerobic aquatic 46578967 6 (42 days) 5 (42 days) AR phe label 6 (100 days) 4 (150 days) CA phe label DOP amine, S13, H6 Hydrolysis 46219016 4 (1hr) 4 (1hr, pH 4, 50 o C) pH 4, 50 o C 11 (52 hrs) 11 (52 hrs) pH 7, 50 o C 53 (13 days) 53 (13 days) pH 9, 50 o C

Aerobic aquatic 46219017 1 (90 days) 1 (90 days) AR sediment 1 (30 days) 1 (90 days) CA sediment
Anaerobic Aquatic 46578967 <1 (100 days) <1 (180 days) AR pyr label

DOP urea, IR7825, S12, H5 Hydrolysis 46219016 78 (1hr) 78 (1hr) pH 4, 50 o C 60 (52 hrs) 60 (52 hrs) pH 7, 50 o C 13 (13 days) 13 (13 days) pH 9, 50 o C

Aerobic Aquatic 46219017 47 (90 days) 47 (90 days) AR pyr label 40 (30 days) 36 (61 days) CA pyr label

Anaerobic Aquatic 46578967 12 (42 days) 3 (180 days) AR pyr label 19 (59 days) 16 (150 days) CA pyr label

Aquatic Field Dissipation 46578985 0.07 mg/kg (186 day) 0.024 mg/kg (123 day) AR soil 0.147 mg/kg (15 day) 0.041 mg/kg (60 day) AR sediment <0.005 mg./L (60 days) <0.005 mg./L (60 days) AR water 0.089 (194 day) 0.033 mg/kg (553 day) CA soil 0.162 mg/kg (7 day) 0.023 mg/kg (60 day) CA sediment <0.005 mg/L (30 days) nd (60 days) CA water DBS amide, S2, H2 Hydrolysis 46219015 7 ( 37 days) 7 ( 37 days) pH 7, 25 o C 8 (176 days) 8 (176 days) pH 9, 25 o C 9 (0.13 days) 1 (0.04 days) pH 4, 50 o C 8 (2 days) 5 (5 days) pH 7, 50 o C 10 (5 days) 10 (5 days) pH 9, 50 o C

Anaerobic aquatic 46578967 4 (180 days) 4 (180 days) AR phe label

4 (150 days) 4 (150 days) CA phe label

Aerobic aquatic 46219017 4 (90 days) 4 (90 days) AR phe label 4 (61 days) 4 (61 days) CA phe label O-desmethyl Aerobic 46219017 9 (90 days) 9 (90 days) AR pyr label

### 138 Common Name or Code Name Study Type MRID Max %AR or Conc. (sampling interval) Final %AR or Conc. (sampling interval) Descriptive Information
for Value

IR5878, Odesmethyl orthosulfamuron, IR8181, S9 aquatic 7 (90 days) 7 (90 days) AR phe label 7 (30 days) 6 (90 days) CA pyr label 6 (44 days) 6 (61 days) CA phe label

Anaerobic aquatic 46578967 19 (100 days) 16 (180 days) AR phe label

17 (180 days) 17 (180 days) AR pyr label 12 (59 days) 4 (150 days) CA pyr label 13 (35 days) 4 (150 days) CA phe label S11 (multiple unresolved compounds) Aerobic aquatic 46219017 3 (90 days) 3 (90 days) AR 6 (90 days) 6 (90 days) CA
Anaerobic Aquatic 46578967 23 (180 days) 23.18 (180 days) AR pyr label

S5 (multiple unresolved compounds) Aerobic aquatic 46219017 4 (90 days) 4 (90 days) AR 4 (90 days) 4 (90 days) CA

Anaerobic aquatic 46578967 22 (180 days) 22 (180 days) AR phe label
16 (100 daysphe) 15, (150 days) CA phe label

o-desmethyl DOP urea, S15 Aerobic aquatic 46219017 <1 (90 days) <1 (90 days) AR
4 (44 days) 3 (61 days) CA
Anaerobic aquatic 46578967 3 (180 days, AR pyr) 3 (180 days, AR pyr)

S6 Aerobic aquatic 46219017 <1 (7 days) 0.0 (90 days) AR
nd nd CA

S8 Aerobic aquatic 46219017 <1 (90 days) <1 (90 days) AR
nd nd CA

Anaerobic aquatic 46578967 2 (180 days) 2 (180 days) AR phe label 2 (100 days) 2 (150 days) CA phe label IR8181 Aquatic field dissipation 46578985 nd nd CA or AR

S16 Anaerobic aquatic 46578967 <1 (180 days) <1 (180 days) AR pyr label 1 (0 days) <1 (180 days) AR phe label 1 (0 days) < LOD (150 days) CA phe label

S7 Anaerobic aquatic 46578967 <1 (15 days) < LOD (180 days) AR phe label <1 (15 days) <LOD (150 days) CA phe label 

### Abbreviations: %AR=percent applied radio activity present as the identified compound; Conc.=concentration measured in field study; phe = phenyl ring radiolab eled; pyrimidinyl ring radiolabeled; CA=California; AR=Arkansas; LOD=limit of detection

### 139 Appendix K. Calculations for Gro und Water Used for Irrigation Exposure

To estimate exposure to plants when paddy water contaminated by orthosulfamuron is applied to crops, the following method was used.

Assume a field is irrigated w ith one inch of water contai ning 57 μg/L orthosulfamuron.

One acre has 6,272,640 cubic inches of water on the field. The one acre field with 1 inch of water has 3,630 cubic ft of water (6,272,640 x 0.00058 cubic ft/cubic inch). The field has 27,156 gallons of water (3,630 cubic ft x 7.481 gallons/cubic ft). Theref ore, one inch of water on the one acre field weighs 226,625 lbs (27,156 gallons x 8.3453 lbs/gallon of water).

226,625 lb of water/acre x 57 μg/L = 0.012 lbs a.i./A 1,000,000,000

### 140 Appendix L. Preliminary Esti mate of Exposure and Risk to Terrestrial Animals for DOP urea and O-desmethyl DOP urea.

The application rate for the ureas was estimated using the following equation.

Urea application rate =

observed urea DOP Maximum

uron Orthosulam of Weight Molecular Urea DOP of Weight Molecular Parent of Rate n Applicatio × ×

Where the maximum amount of DOP urea obser ved is the maximum amount of applied radioactivity observed as DOP ur ea over the total applied radioac tivity in the hydrolysis study. The exact calculation is shown below. O-de smethyl DOP urea was not observed in the hydrolysis studies.

= 0.067 lbs ai/A ×155.16÷424.4 × 0.78 = 0.019 lbs DOP urea/A

Toxicity Inputs are shown below:

Test Species Source Compound

Avian LD50 (mg/kg-bw) 940 Bobwhite Quail MRID 00150170 Linuron

Avian LC50 (mg/kg-diet) 1700 Bobwhite Quail MRID 00034769 Linuron

Avian NOAEC (mg/kg-diet) 100 Bobwhite Quail and Mallard Duck MRID 42541801, 41864701 Linuron

MammalianLD50 (mg/kgbw) 677 Rat MRID 47305223 DOP urea

Reported chronic Endpoint (mg/kg-bw) 0.74 Rat MRID 41463401 Linuron

Mammalian Dietary Concentration (mg/kg-diet) 12.50 Rat MRID 41463401, 41864701 Linuron

### 141

### 142

### 143 Appendix M. Data Table for Non-Guideline Studies

Guideline Number: none Study Titles: Special Study for Non-Target Plant Reproductive Toxicity Rationale for Requiring the Data As stated in the Problem Formulation, investigati ons/studies have indicated a small percentage of the label application rate of low dose high potency herbicides such as sulfonylureas ( e.g . orthosulfamuron) may impact the reproduction of non-target terrestrial plants. However, there are no available data on adverse reproductive impacts to terrestrial plants fro m orthosulfamuron residues due to spray drift. Terrestrial plant reproductive toxicity data would he lp to screen for potential plant risks associated with orthosulfamuron use. Plants form the basis of mo st habitats and contribute significantly to overall environmental quality. The loss of plant reproductive output could potentially have an adverse effect on animals, both invertebrates and vertebrates, as many are dependant on plant reproduction for a food source and for habitat quality and structure. A solid understanding of the potential risks to plants is therefore essential for sound environmental manage ment. A study protocol must be submitted for review and approved by the Agency prior to initiation of the study. Practical Utility of the Data How will the data be used? The data will be used to estimate potential reproductiv e risks to non-target terrestrial plants, including the likelihood of potential risks to enda ngered species, either by direct effects or by indirect effects, and to reduce uncertainties associated with the curre nt ecological risk assessment. By refining the assessment, the Agency will be able to determine wh ether current labeling is appropriate and whether further mitigation is necessary. In the absence of this data, risks to terrestrial plants will be presumed.

How could the data impact the Agency’s future decision-making? These data, once submitted, should allow the Agency to characterize the risk posed to plant reproductive processes from orthosulfamuron in te rrestrial ecosystems. Primary producers ( i.e,. plants) provide food and habitat vi tal to ecological processes. Therefore, a solid understanding of the potential risks to non-target plants is essential in orde r to assess the environmental risks the use of orthosulfamuorn may pose. If the data indicate that orthosulfamuron poses significant risks to these non-target plant species, the Agency may explore ad ditional decision options to minimize the risks to these species. The lack of these data will limit th e flexibility the Agency and registrants have in complying with the Endangered Species Act and could result in use restrictions for orthosulfamuron which may otherwise be avoided, or which are unnecessarily severe.