### 2 studies needed to address uncertainties identified in the environmental fate and ecological effects
database for chlorsulfuron

.

### 3 

# Problem Formulation for the
Environmental Fate and Ecological Risk , Endangered Species, and Human Health Drinking Water
Assessment s in Support of the R egistration Review of
Chlorsulfuron

Chlorsulfuron (CAS 64902

- 72

- 3 )
PC Code 118601

Prepared by: Mary Clock

- Rust, Biologist Katrina White, Ph.D., Biologist U. S. Environmental Protection Agency Office of Pesticide Programs
Environmental Fate and Effects Division
Environmental Risk Branch IV 1200 Pennsylvania Ave., NW
Mail Code 7507P Washington, DC 20460 Reviewed by: 

### Jim Carleton

, Ph.D., Senior Fate Scientist Thomas Steeger, Ph

. D., Senior Biologist Marietta Echeverria, Branch Chief

November 15 , 2012

### 4 Table of Contents

1. Purpose

................................ ................................ ................................ ................................ ........ 6
2. Description of Regulatory Action

................................ ................................ ............................... 6
3. Conclusions from Previous Risk Assessments

................................ ................................ ........... 6
4. Mechanism of Action

................................ ................................ ................................ .................. 8 5. Overview of Pesticide Usage

................................ ................................ ................................ ...... 8 6. Environmental Fate and Transport

................................ ................................ ............................ 10 6.1. Monitoring Data

................................ ................................ ................................ ................. 16
6.2. Clean Water Act

................................ ................................ ................................ ................. 17
7. Receptors

................................ ................................ ................................ ................................ ... 18 7.1. Effects to Aquatic Organisms

................................ ................................ ............................ 20 7.2. Effects to Terrestrial Organisms

................................ ................................ ........................ 21 7.3. Degradate Toxicity

................................ ................................ ................................ ............. 23 7.4. Ecological Incidents

................................ ................................ ................................ ........... 23
8. Eva luation of Non

- definitive Toxicity Values

................................ ................................ .......... 25 9. Ecosystems Potentially at Risk

................................ ................................ ................................ . 26 10. Assessment Endpoints

................................ ................................ ................................ ............ 26
11. Identification of Stressors of Concern

................................ ................................ .................... 26 12. Risk Hypothesis

................................ ................................ ................................ ...................... 29 13. Exposure Pathways of Concern, Models, and Toxicity Endpoints

................................ ......... 30 14. Analysis Plan

................................ ................................ ................................ .......................... 31 14.1. Measures of Exposure

................................ ................................ ................................ ...... 32
14.1.A. Exposure in the Aquatic Environment

................................ ................................ 32
14.1.B. Exposure to Terrestrial Animals

................................ ................................ ......... 33
14.1.C. Exposure to Terrestrial Plants

................................ ................................ ............. 33
14.1.D. Exposure to Spray Drift

................................ ................................ ....................... 34
14.2. Measures of Effect

................................ ................................ ................................ ........... 34
14.3. In tegration of Exposure and Effects

................................ ................................ ................ 35
14.3.A. Deterministic and Probabilistic Assessment Methods

................................ ........ 35 14.4. Endangered Species Assessments

................................ ................................ .................... 36 14.5. Human Health Drinking Water Assessment

................................ ................................ .... 36 14.6. Endocrine Disruptor Screening Program

................................ ................................ ......... 37 15. Preliminary Identification of Data Gaps

................................ ................................ ................. 38
15.1. Fate

................................ ................................ ................................ ................................ ... 38
15.1.A. Rationales for Requesting Fate Studies

................................ ............................... 41
15.1.B Rationales for Not Requesting Fate Studies

................................ ........................ 42
15.1.A. Additional Information that would be Useful for Monitoring and Risk
Assessment

................................ ................................ ................................ ............................ 43
15.2. Effects

................................ ................................ ................................ .............................. 43
15.2.A. Degradate Toxicity Data

................................ ................................ ..................... 46
16. Other Information Needs

................................ ................................ ................................ ........ 46
17. References

................................ ................................ ................................ ............................... 47
17.1. Studies Related to Environmental Fate Data

................................ ................................ ... 50 17.2. Data submitted on Ecological Effects

................................ ................................ .............. 55

### 5 List of Tables

Table 1. Previously Estimated Drinking Water Concentrations for the Human Health Risk
Assessment

................................ ................................ ................................ ................................ ...... 8
Ta ble 2. Summary of physical

- chemical properties of chlorsulfuron 1



### ................................ ........ 10
Table 3. Abiotic and Biotic Transformation of Chlorsulfuron

................................ .................... 12
Table 4. Summary of Submitted Sorption Studies of Chlorsulfuron (MRID 42156705) 2



### .......... 14 Table 5. Summary of maximum amount of transformation products observed in fate studies.

.. 16 Table 6. OPP Aquatic Life Benchmarks for Chlorsulfuron in μg a.i./L 1



### ................................ .... 17 Table 7. Most Sensitive Species Evaluated for Potential Ecological Effects from Chlorsulfuron.

................................ ................................ ................................ ................................ ....................... 18 Table 8. Summary of residues of concern for different classes of organisms

............................. 28 Table 9. Summary of exposure pathways, endpoints, and models used in risk assessmen t.

....... 31 Table 10. Summary of Submitted Environmental Fate Studies, Study Classifications and Data Gaps for Chlorsulfuron and Its Degr adates

................................ ................................ .................. 38 Table 11. Summary of Submitted Ecological Effects Studies and Data Gaps for Parent
Chlorsulfuron

................................ ................................ ................................ ................................ 44

List of Figures

Figure 1. Potential Degradation Pathway of Chlorsulfuron Based on Degradates Obserbed in Laboratory and Field Studies

................................ ................................ ................................ ........ 15

List of Appendices

Appendix A. List of Registered Products Containing Chlorsulfu ron and Percent Active Ingredients

................................ ................................ ................................ ................................ ..... 60 Appendix B. ECOSAR and ASTER Output

................................ ................................ ................ 62 Appendix C. Ecological Toxicity Summary for Aquatic and Terrestrial Organisms from
Chlorsulfuron

................................ ................................ ................................ ................................ 90 Appendix D. Results from Screening Imbibition Program (SIP) and the Screening Tool for Inhalation Risk Assessment (STIR)

................................ ................................ .............................. 93 Appendix E. Example T

- Rex Input and Output for Chlorsulfuron.

................................ ............ 96 Appendix F. Example Terrplant (v. 1.2.2) Input and Output for Chlorsulfuron

........................ 98 Appendix G. Referen ce List for OPPTS/OCSPP Fate Guidelines

................................ .............. 99 Appendix H. Identification of Transformation Products and Listing of the Maximum Amount s Observed in Fate Studies

................................ ................................ ................................ ............ 101 Appendix I. Justification of the Identified Residues of Concern

................................ ............... 108

### 6 

## 1. **Purpose**

The purpose of this problem formulation is to provide an understanding of the environmental fate
and ecological effects of the registered uses of chlorsulfuron ( 1

- (2

- chlorophenylsulfonyl)

- 3

- (4

- methoxy

- 6

- methyl

- 1,3,5

- triazin

- 2

- yl)urea) , the first regist e re d sulfonyl urea herbicide in United
States

. It is a systemic pre or post

- emergent herbicide used to control both grass and broadleaf weeds, and is registered for use on agricultural and nonagricultural crops

. This document provide s a plan for analyzing data relevant to chlorsulfuron and for conducting an environmental fate and ecological risk, Federally

- listed endangered /threatened species (hereafter referred to as “listed” species) , and human health drinking water assessments for its registered uses. Additionally, this problem formulation is intended to identify data gaps, uncertainties, and potential assumptions used to address those unc ertainties, relative to characterizing the ecological risk associated with the registered uses of chlorsulfuron

.



## 2. **Description of Regulatory Action** 

The Food Quality Protection Act of 1996 mandated the Environmental Protection Agency (EPA) to implement a n ew program for assessing the risks of pesticides, i.e ., Registration Review ( http://www.epa.gov/oppsrrd1/registration_review/ ). All pesticides distributed 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 that it will not cause unreasonable risks to human health, workers, or the environment when used as directed on prod uct labeling. The Registration Review program is intended to ensure that, as the ability to assess risk evolves and as policies and practices change, all registered pesticides continue to meet the statutory standard of no unreasonable adverse effects to hu man health and the environment. Changes in science, public policy, and pesticide use practices will occur over time

, and t hrough the new Registration Review program, the Agency periodically reevaluates pesticides to ensure that as change occurs, products i n the marketplace can be used safely.

As part of the implementation of the new Registration Review program pursuant to Section 3(g) of the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA), the Agency is beginning its
evaluation to determine whet her chlorsulfuron continues to meet the FIFRA standard for registration. This problem formulation for the environmental fate and ecological risk assessment chapter in support of the R egistration R eview is intended for the initial docket opening the public phase of the review process.



## 3. **Conclusions from Previous Risk Assessments**

The Agency has conducted multiple ecological risk assessments on chlorsulfuron that serve as a
basis for this Problem Formulation , including the most recently completed ecological risk assessment written in support of the Reregistration Eligibility Decision (RED ) ( Kiernan and Young, 2005, DP330621 )

. The previously evaluated uses include aerial and ground applications to cereal grains (wheat, oats, and barley), pasture and rangeland, and fa llow land. Ground applications were evaluated for lawns, ornamental turf, sod farms, and non

- cropland , such as roadway rights

- of

- way, airports, and other areas

. The highest seasonal application rate evaluated

### 7 was for ground applications to ornamentals an d turf ( 0.25 lbs a.i./acre applied twice a year ) . The highest aerial application rate evaluated was for pasture and rangeland ( 0 .0 6 25 lbs a.i./acre/year )

. The label s did not specify a maximum number of applications or re application interval.

Exposure was estimated for parent chlorsulfuron only

, in the standard EPA farm pond using the Pesticide Root Zone Model coupled with the Exposure Analysis Model System ( PRZM and
EXAM S)

. Based on model output and b ecause of chlorsulfuron’s low degradation rate,
chlorsulfuron concentrations in water were estimated to continually increase over the simulation period and chronic and peak concentrations were all nearly identical for all scenarios tested. The maximum one in ten year peak, 21

- day average , and 60

- day av erage concentration s in water
were all 9.5 μg/L.

Risk Summary for Chlorsulfuron from EFED’s 2005 Risk Assessment

Based on a screening

- level [deterministic] risk assessment, risk quotients for terrestrial and aquatic animals do not exceed either acute or chronic risk levels of concern [LOCs] at current maximum application rates; however, LOCs for risks to nontarget terrestrial and aquatic plants are exceeded by orders of magnitude. [Screening l evel RQs for listed aquatic and terrestrial plants ranged from 18 to 580.] In regions where chlorsulfuron has been used regularly, chlorsulfuron concentrations in ground and surface irrigation water may result in damage to agricultural crops that are sens itive to chlorsulfuron. Additionally, uncertainty was identified regarding the potential effects that drift may have

on fruit development in nontarget plant communities. 1



### Because LOCs for plants are exceeded, indirect effects to all listed species have the potential to

occur.

Chlorsulfuron Spray Drift onto Non

- Target Terrestrial Plants

In 2005, EFED conducted a refined spray drift assessment to better characterize the potential risk

to non

- target plants at varying distances from a chlorsulfuron

- treated field. The results of th e assessment indicate that while the extent of potential risk depends on the applicatio n rates and
environmental conditions, almost all of the exposure scenarios indicate the potential for adverse effects to plants hundreds of feet from chlorsulfuron

- treated fields.

Drinking Water Assessment

A drinking water assessment was completed at the same time that the RED ecological risk

assessment was completed for chlorsulfuron ( Kiernan and Young, 2005, DP330621 )

. Drinking water exposure was evaluated for use on wheat and turf. Estimated drinking water concentrations (EDWCs) in surface water were estimated using PRZM/EXAMs. The Screening Concentration in Ground Water ( SCIGROW ) model was used to estimate exposure to residues in ground water. Table 1 provides details on the reported EDWCs. A drinking water assessment for the highest current use pattern 2 

### has not been conducted.

1 ( J.S. Fletcher et al. , 1993 )

2 According to the EFED Label Data Report comp leted on 08/03/2012, the highest current use pattern has a single

### 8 Table 1

. Previously Estimated Drinking Water C oncentrations for t he Human Health Risk
A ssessment

Use Estimated Drinking Water Concentration (μg chlorsulfuron/L water)
Surface Water Ground Wa ter Peak Annual Mean
Wheat 1

0.023 lb s a.i./A 0.95 0.25

Turf 2

0.0625 lbs a.i./A 1.9 0.96 1.6

1 A PCA of 0.57 was used with the surface water EDWC.

2 A PCA of 0.87 was used in the surface water EDWC.



## 4. **Mechanism of Action**

Chlorsulfuron is a sulfonylurea herbicide ( Wood, 2009 ) . It is a systemic pre or post

- emergen ce herbicide used to control both grass and broadleaf weeds

, and is registered for use on agricultural and nonagri cultural crops

. Its mode of action in plants is through inhibition of the enzyme acetolactate synthetase (ALS) which results in inhibition of branched chain amino acid biosynthesis ( Ware and Whitacre, 2004 ) . Inh ibition of this enzyme blocks biosynthesis of the branch chain amino acids valine, leucine, and isoleucine involved in plant growth and leads to plant death.



## 5. **Overview of Pesticide Usage**

Chlorsulfuron was first registered in 1982 by Du Pont under a Sectio n 3 registration for use on wheat, barley and forage grasses and non

- cropland grasses and tree plantings ( USEPA, 2005 )

.

Chlorsulfuron is formulated in 36 active end

- use products and is formulated as a flowable concentrate, granular, and water dispersible granular. Twenty

- two co

- formulated products containing chlorsulfuron also have one of the following active ingredients : aminocyclopyrachlor,
flucarbazone

- sodium, metsulfuron, sulfentrazone or sulf o meturon. A pplication methods include broadcast, low volume ground spray, soil and spot treatment, han dguns, boom sprayers, backpacks, and / or hand held sprayers. It may be applied using aerial and ground application
methods. Application method timings include fallow, preplant, postplant, and postemergence. The chemical profile produced by the Office of P esticide Programs’ Biological and Economic Assessment Division ( BEAD ) ( Ratnayak e et al. , 2012 ) and Label Use Information System (LUIS) t ables , located in the docket, lists the use patterns of maximum exposures for the current
uses of chlorsulfuron.

application rate of 0.14 lbs a.i./A, the maximum number of applications, minimum retreatment interval, and the maximum annual application rate per acre are not specified. Use sites allowing this application rate include airports, landing fields, commercial and industrial lawns, commercial storage/warehouses premises, industrial outdoor construction areas, intermittently flooded areas/water, nonagricultural rights of ways/fencerows/hedgerows, nonagricultural uncultivated areas, sewage disposal areas, and dry swamps/marshes/wetlands/stagnant water.

### 9 Currently registered uses include agricultural a nd non

- agricultural use sites as d escribed below:

Agricultural Use Sites Mung beans, ba r ley, field corn, oats, proso millet, safflower, sorghum, soy b eans, triticale, wheat, cotton, pastures, rangeland, forage and fodder grasses, farm yards and uncultivated agricultural

areas.

Non

- Agricul tural Use Sites Ornamental lawns and turf, ditch banks, flood plains (dry), intermittently flooded areas (dry), swamps/marshes/bogs/standing water (vegetation) 3 

### , waterway edges and non

- agricultural uncultivated areas/soils (airports, fencerows, military in stallations, rights

- of

- way, walkways, paths, etc. ).

The Appendix A Label Data Report (dated 08/03/2012) (dated 08/03/2012) is available in the docket and provide more detailed information on currently registered use patterns. According to
the EFED Label Data Report completed on 08/03/2012, the highest current use pattern has a single application rate of 0.14 lbs a.i./A, the maximum number of applications, minimum retreatment interval, and the maximum annual application rate per acre are not specified. U se sites allowing this application rate include airports, landing fields, commercial and industrial lawns, commercial storage/warehouses premises, industrial outdoor construction areas, intermittently flooded areas/water, nonagricultural rights of ways/fen cerows/hedgerows, nonagricultural uncultivated areas, sewage disposal areas, and dry swamps/marshes/wetlands/stagnant water. The labels do not have language that prohibits aerial applications and it is assumed that aerial applications may occur. The lowe st reported maximum single application rate is 0.0078 lb a.i./A, with a maximum of 1 application per crop cycle is for use on wheat and barley. The corresponding minimum retreatment interval is not specified and the maximum annual application rate is 0.06 25 lb a.i./A. There are higher maximum application rates for wheat and barley on other labels and some only include the maximum single application rate and lack information on the maximum number of applications, maximum annual application
rate and minimum retreatment interval.

Based on the BEAD chemical profile ( Ratnayake et al. , 2012 ) , the majority of chlorsulfuron applied to agricultural areas is applied to winter wheat (~95%). Smaller percentages (~2%) are applied to spring wheat and pastureland. Usage on nonagricultural crops is not quantified and reported on in the BEAD chemic al profile.

Based on the BEAD chemical profile, labels for chlorsulfuron allow for use in agricultural
uncultivated areas and non

- agricultural uncultivated areas. A clear definition of what sites are
included or excluded based on these terms is needed. Unclear label terminology could lead to
use of chlorsulfuron on areas that are not intended use sites

. Information on more specific use sites would allow a more refined/precise risk assessment. Defining use sites is important in determining where a produc t may be used, and which endangered species may be in proximity to locations of potential uses of chlorsulfuron.

Some labels include the following statements or similar statements in the general information

3 These uses do not include applications directly to water.

### 10 section:

“ Some of these sites contain temporary pools of surface water as a result of site management. Use this product to treat intermittent drainage, intermittently flooded low lying sites, seasonally dry flood plains and transitional areas between upland and lowland sites when no water is
present. In addition, apply this product to bogs, marshes, and swamps after water has receded and to seasonally dry flood deltas. Do not make applications to natural or man

- made bodies of water such as canals, lakes, ponds, reservoirs, and streams .”

After applic ations to these areas, chlorsulfuron could potentially be introduced into water when water levels rise. More information on these uses (both on labels and what are the current practices ) would improve the ability to predict potential exposure in aquatic s ystems.

As a result of the potential risk to off

- target plants from chlorsulfuron spray drift, some chlorsulfuron labels include a section highl i ghting spray drift management.



## 6. **Environmental Fate and Transport**

Chlorsulfuron will enter the environment via spray applied directly onto soil and foliage. It may
move off

- site via spray drift, leaching, and runoff. Chlorsulfuron may be applied to areas where flooding may occur after the application

, and may also be introduced into water bodies when
water levels rise and come into contact with soil containing residues of chlorsulfuron

.

Table 2 summarizes the iden tity information and physical

- chemical properties of chlorsulfuron.
Chlorsulfuron has a log dissociation constant ( pK a 

### ) of 3.4 and is a weak acid indicating it will primarily exist as a negatively charged ion (anion) in the natural environment . Its solubi lity increases with pH (587 mg/L at pH 5 and 3,380,000 mg/L at pH 7). Chlorsulfuron is considered

non

- volatile from dry non

- adsorbing surfaces, water, and moist soil (OPPTS 4 

### Guideline
835.6100 classification )

. Bas ed on chlorsulfuron’s log octanol

- water pa rtition coefficient (K OW 

### )
values of

- 1.41 to 0.34 and log octanol

- air partition coefficient (K OA 

### ) values of

- 12.2 to

- 15.9, it is not likely to bioconcentrate in aquatic or terrestrial organisms.

Table 2 . Summary of physical

- chemical properties of chlorsulfuron 1

Parameter Value and Units Source and/or Comment
PC Code 118601 ( USEPA, 2012c )
CAS Number CAS 64902

- 72

- 3 ( USEPA, 2012c )

SMILES Code C1=CC=CC(=C1[S](NC(NC2=NC(=NC(=N2 )C)OC)=O)(=O)=O)Cl ( USEPA, 2012c )

Chemical Name 1

- (2

- chlorophenyl)sulfonyl

- 3

- (4

- methoxy

- 6

- methyl

- 1,3,5

- triazin

- 2

- yl)urea (IUPAC) ( USEPA, 2012c )

Empirical Formula C 12 H 12 ClN 5 O 4 S ( USEPA, 2012c )

Molecular Weight 357.77 g/mole calculated

4 Office of Prevention, Pesticides, and Toxic Substances ( OPPTS ) is now the Office of Ch emical Safety and Pollution Prevention (OCSPP); however, some guidelines still reference OPPTS.

### 11 Parameter Value and Units Source and/or Comment
UV/Visible Absorption No absorbance maxima was observed above
290 nm MRID 47179901

Water Solubility pH 5 at 25 o C: 587±18.7 mg/L pH 7 at 25 o C: 3,180,000 mg/L MRID: 42454104 ( Gregg, 2008 )

Vapor Pressure 2.3×10 - 11 Torr at 25 o C MRID: 42454105 and identical 43898601;
Non

- volatile under field conditions Henry’s Law

constant pH 5: 1.71×10 - 14 atm

- m 3 /mol pH 7: 3.15×10 - 18 atm

- m 3 /mol Estimated from vapor pressure and water solubility at 25 o C.

Dissociation Constant (pK
a ) 3.4 weak acid ( Gregg, 2008 )

Octanol

- water partition coefficient ( K
ow ) pH 5 at 25 o C : 2.19 and 2.07 (log K OW ~0.34) pH 7 at 25 o C : 0.110 and 0.0947 (log K OW ~ - 0.95) pH 9 at 25 o C : 0.0387 (log K OW ~ - 1.41) MRID: 42454107 Not likely to bioconcentrate

Air

- water partition coefficient (K AW ) pH 5: 6.98 × 10 - 13 (log K AW =

- 12.2) pH 7: 1.29 × 10 - 16 (log K AW =

- 15.9) Non

- volatile from water surface

. Estimated from vapor pressure

and water solubility at 25 o C.

Octanol

- air partition coefficient (K OA ) pH 5: 1.4×10 8 (log K OA = 12.5) pH 7: 8.54×10 - 14 (log K OA = 14.9) Estimated from K AW and K OW
. Unlikely to
accumulate in terrestrial organisms due to low log K OW
. 2

C water+soil /C air pH 7: 8.4×10 15 Estimated from K AW , ratio of soil/weight of water ( r ) of 6, and measured K F of 0.91 L/kg which was assumed to be equivalent to the K d value

. Nonvolatile 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, 2010 )

. 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, further proof is needed before accepting t hese limits without reservations” ( USEPA, 2009c ) . This was also supported by Armitage and Gobas’s work completed in 2007 ( Armitage and Gob as, 2007 )

.



### Table 3 summarizes abiotic and biotic transformation data. The range of half

- lives for
chlorsulfuron in soil and water indicate s that it is persistent to very persistent (Toxic Release Inventory Classification) with half

- lives ranging from 13 days to stable ( Table 3 ) ( USEPA,
2012a )

. Hydrolysis is the primary mechanism of degradation at low pH. However, in neutral and alkaline environments, biodegradation is expected to dominate as pH increases and ch lorsulfuron becomes less susceptible to hydrolysis.

Chlorsulfuron is stable to hydrolysis except at acidic pH where the half

- life is 22

- 23 days at 25 o 

### C (MRID 42156701) . It is stable to aqueous photolysis and degrades slowly via soil photolysis (half

- li ves ranged from 138

- 183 days in one clay loam soil; MRID 42156702)

.

Only supplemental data are available on aerobic soil metabolism

, for which available half

- live s range from 60 to 299 days in eight soils ( Table 3 )

. Unextracted and unidentified residues were present in some soils and it was unknown whether these residues were a residue of concern; additionaly data on the extraction efficiency were not available and exhaustive extractions were

### 12 not completed. Therefore, degradation kinetics were calculated assuming that unidentified and
unextracted residues were a residue of concern. Submitted aquatic metabolism data are not considered valid

. Anaer obic soil metabolism and aerobic aquatic metabolism data were not
submitted.

Table 3 . Abiotic and Biotic Transformation of Chlorsulfuron

Parameter Calculated DT50 or Half

- life (days) 1 Source (Study Classification) Comments

Hydrolysis SFO linear regression, 1 24±1 o C: pH 5 at 25 o C: 22.4

- 23.1 days (SFO) pH 7 at 25 o C: Stable pH 9 at 25 o C: Stable MRID 42156701

same as 41408102 Acceptable SFO linear regression, 1 20 o C: pH 4 at 20 o C: not stable pH 7 at 20 o C: Stable pH 9 at 20 o C: Stable MRID 00035270
no DER Study not consistent with guideline ( Garner, 1980 )

.

Atmospheric Degradation Hydroxyl radical reaction rate: 4 days (estimated) Estimated Using
EPIWeb Version
4.1 see Appendix
A

. - Assumed 12

- hour day; 1.5×10 6 OH
molecules/cm 3 using EPIweb
version 4.1 ( USEPA, 2009b )

- Chlorsulfuron is considered
nonvolatile and thus li ttle is expected to volatilize into air. The
small amount that does volatilize may undergo long range transport in
air. 2

Aqueous Photolysis 24±1 o C Stable (pH 5, 7, 9) MRID 42156702

same as 41408101 Acceptable

Soil Photolysis SFO linear reg. 25±5 o C 1 , pH 8.0: 138 days, clay loam, triazine label 183 days, clay loam, phenyl label MRID 41721001; duplicate of
42156703 Acceptable Calculated for 52 o N latitude.

Aerobic Soil
Metabolism 3 SFO linear reg 1

, temperature NR: 60 days, silt loam, pH 6.0 60 days, sandy loam, pH 6.4 00035273 Supplemental

not for use in

modeling - May not be used to fulfill guideline.

- Maintained in a greenhouse and the temperature was not held constant.

- Soil was sieved with 0.157 inch screen, soil moisture 20

- 80% water holding capacity, not conducted in dark, mass balance low.
25 o C
0.1 mg/kg silt loam, pH 6.4
13.0 (IORE) and 17.3 (SFO) parent 13. 4 (IORE) and 22.4 (SF) parent+unext 2 99 (SFO) parent+unext+unident

1.0 mg/kg silt loam soil, pH 6.4 12.1 (SFO) parent
12 (IORE) and 13 (SFO), parent+unext Stable, parent+unext+unident MRID 00035275 duplicates of

00086814
00083950 Supplemental

May be used in modeling depending on
what other data

are ava ilable 5 - May not be used to fulfill guideline. One ring labeled. One replicate. No raw data. Degradates not followed.

- Data were available at two

concentrations in one soil. For modeling, the longest value recommended for model input
across the concentrations w ill be
used as the value to be used to estimate a representative model input value for that soil using the
NAFTA guidance 4

.

### 13 Parameter Calculated DT50 or Half

- life (days) 1 Source (Study Classification) Comments

Anaerobic
Soil
Metabolism No data submitted

-- --

Aerobic Aquatic
Metabolism No data submitted

-- --

Anaerobic Aquatic
Metabolism SFO linear, 25 o C: 445 days, PA, pond, pH 5.6, tri 170 days, PA, pond, pH 5.6, phe 66 days, Alberta, pond, pH 8.4, phe 86 days, NE, pond, pH 8.3, phe 47 days, IL, pond, pH 5.0, phe MRID 42156704 update to
00086815 Supplemental

not for use in

modeling - May not be used to fulfill guideline.

- Alfalfa added to test system.

- Rates were faster in sterile controls
in the PA ponds suggesting that degradation was not mediated by
microbes.
Abbreviations: ECM=Environmental Chemistry Method; ILV=Independent Laboratory Validation; SFO=Single First Order; NA: Not Applicable; unext=unextracted; unident=unidentified; reg=regression

1 DT50 values were calculated using linear regression and the single first order equation or nonlinear regression and single first order (SFO), double first order in parallel (DFOP), or indeterminate order equations (IORE). An SFO value is reported for all studies. In addition, an IORE value was reported when that was the recommended model
based on “Guidance for Evaluating and Calculating Degradation Kinetics in Environmental Media” dated December 21, 2011, available at http://www.epa.gov/oppfead1/international/naftatwg/guidance/degradation

- kin.pdf (accessed
11 / 15 /2012)

. The value used to estimate a model input value is a calculated SFO DT 50 , T IORE , or the slow DT 50 fr om the DFOP equation. The values in this table do not necessarily reflect the values that will be used to estimate a model input value.

2 The minutes of the Scientific Advisory Panel examining issues related to persist ent, bioaccumulative, and toxics states, “To protect against long range transport, a two

- day degradation half

- life in air is used internationally in regulations that identify persistent chemicals.” ( USEPA, 2009c )

3 MRID 42214201 is an aerobic soil metabolism stud y that summarizes many studies including MRID 00035273

. All studies were determined to be unacceptable , except MRID 00035273 , which was reviewed under MRID
00035273.

4 When the SFO model does not fit the data well (as determined by the Guidance for Evaluating and Calculating Degradation Kinetics in Environmental Media available at http://www.epa.gov/oppfead1/international/naftatwg/guidance/degradation

- kin.pdf ), a first estimate of the representative half

- life for modeling is made by calculating T IORE . T IORE is the half

- life of a SFO model that passes through a hypothetical DT90 of the Indeterminate Order Rate Equation (IORE) fit. An additional fit of the Double
First Or der in Parallel (DFOP) is also determined. The shorter of T IORE versus the DFOP slow rate half

- life is used as the representative value for modeling. If these values are the only data available for modeling, the value for this
one soil will then be multiplied by three to account for the uncertainty in aerobic soil metabolism ( NAFTA, 2012 )

. 5 These data are supplemental and additionall data are requested because these data may not be used to fulfill the guideline. However, in the absence of additional data, these data may be used in estimating exposure as they are the only data available. Mass balances were low at only a couple of sampling points (87%) and unidentified residues were high (up to 48%). If these data were used in modeling, assumptions would be made to ensure that the use of
these data were conservative.



### Chlorsulfuron is classified as mobi le to highly mobile with Freundlich organic carbon
normalized soil

- water distribution coefficients (K FOC 

### ) values ranging from 8 to 31 (mg/L)(mg/kg) -

1/n 

### measured in four soils (MRID 42156705 ; Table 4 ) 5



### . It has the potential to move to ground

water. Based on chlorsulfuron’s water solubilities and pK
a 

### value, its affinity to organic materials (and thus organic carbon partition coefficient, K OC 

### ) is expected to decrease with increasing pH

.

5 MRID 42214202 and 43421401 are classified as supplemental because the identity of the radioactivity was not determined. Using the lowest available degradation half

- life, it was determined that at least 95% of the radioactivity should be the parent. Ther efore, additional data on sorption coefficients were not requested.

### 14 Table 4

. Summary of Submitted Sorption Studies of Chlorsulfuron (MRID 42156705) 2

Soil, texture %
sand %
silt % clay %
OC s oil pH K F ( mg/ L)( m

g/kg) - 1/n 1/n K F OC ( mg/ L)( mg/ kg) - 1/n Chlorsulfuron
concentration in

water (mg/L) 1

Madera

, loam 48 35 17 0.46 8 0.28 0.9 35 0.15

– 4.53

Woodstone

, sandy loam 60 33 7 0.64 6.6 0.09 0.85 8 0.17

– 5.31

Keyport , silt
loam 20 39 21 1.1 5.7 0.38 0.88 20 0.13

– 4.3

Flanagan , silt
loam 2 81 17 2.5 5.4 0.91 0.91 21 0.09

– 3.06

1 The sorption coefficients are applicable over the range of equilibrium chlorsulfuron concentrations in water over
which the coefficients were measured.

2 Values of K d and K OC values were not calculated for this study. Values of K d and K OC may be calculated and used in modeling for a future assessment.



### In 15 supplemental field lysimeter studies , estimated dissipation half

- liv e s ranged from 16 days

to 210 days ( MRID 42214202 and 43421401 )

. Leaching of chlorsulfuron was observed, with
detections at depths up to 38 cm. Residues observed in these field studies include parent chlorsulfuron, chlorosulfonamide, triazine amine

, hydroxyl triazine amine

, ring

- opened chlorsulfuron, 2

- chlorophenylsulfonylurea, o

- desmethylchlorsulfuron, and triazine urea

The environmental fate database is not complete, and the information on transformation products may change with the receipt of additional fate data. The following eight transformation products
were observed in environmental fate studies:

• O

- desmethylchlorsulfuron (2

- chloro

- N

- [[(4

- hydroxy

- 6

- methyl

- 1,3,5

- triazine

- 2

- yl)

- amino)carbonyl]benzenesulfanamide; ODMC)

• r ing

- opened chlorsulfuron (1

- (2

- chlorophenylsulfonyl)

- 7

- acetyltriuret; ROC)

• chlorosulfonamide ( 2

- chlorobenzenesulfanamide ; CSM)

• triazine amine (2

- amino

- 4

- methoxy

- 6

- methyl

- 1,3,5

- triazine; TA)

• hydroxyl triazine amine (4

- hydroxy

- 6

- methyl

- 1,3,5

- triazine

- 2

- amine; OHTA)

• dihydroxy triazine (2,4

- dihydroxy

- 6

- methyl

- 1,3,5

- triazine; DT)

• 2

- chlorophenylsulfonylurea (2

- chloro

- N

- (aminocarbonyl)be nzenesulfanamide; CPSU)

• triazine urea (TU)

The following degradation products were hypothesized as potential transformation products by study authors :

• acetylbiuret (1

- acetylbiuret)

• o

- desmethy l triazine amine (ODMTA)

• 5

- hydroxychlorosulfanamide (2

- chloro

- 5

- hydroxybenzenesulfanamide; OHCSM)

• 5

- hydroxychlorsulfuron ( 2

- chloro

- 5

- hydroxy

- N

- [(4

- methoxy

- 6

- methyl

- 1,3,5

- triazin

- 2

- yl)aminocarbonyl] benzenesulfonamide ; OHCSF)

### 15 Figure 1

. Potential Degradation Pathway of Chlorsulfuron Based on Degradates Obserbed in Laboratory and Field Studies Purple and bold values were present at greater than 10% of applied radioactivity in laboratory studies and the
asteri s k indicates the compound was observed in a lysimeter study. Residues that were no t major but were observed in lysimeter studies are blue . Abbreviations are defined in text above figure.



### There were five major degradates observed in the environmental fate laboratory studies: o

desmethylchlorsulfruon

, chlorosulfonamide

, triazine amine

, ring

- opened chlorsulfuron , and 2

- chlorophenylsulfonylurea

. 6 

### Dihydroxy triazine was present at its maximum of 9% at the end of the hydrolysis study (pH 5 only). Had the study continued for longer, it seems likely that dihydroxy triazine would have been fo und to be a major degradate. Table 5 shows the maximum amount of applied radioactivity for each identified transformation product and corresponding s tudy type. Many of the maximum values were observed at the final sampling
interval

. Residues observed in field studies include the major residues observed in the laboratory studies (o

- desmethyl chlorsulfuron, chlorosulfonamide, triazine amine, ring

- opened chlorsulfuron, and 2

- chlorophenylsulfonylurea) and two residues not observed in laboratory studies (tria zine urea and hydroxy triazine amine). Soil column leaching studies suggested that
chlorsulfuron was more mobile than chlorosulfonamide and triazine amine , ex cept for
chlorosulfonamide in a Keyport silt loam soil. MRID 46155803 examines sorption of triaz ine amine and is currently under review.

6 Major degradates are those present at ≥10% applied parent equivalents.

### 16 Table 5 . Summary of maximum amount of transformation products observed in fate
studies.

Chlorsulfuron

degradates f Maximum Degradate % of Applied Radioactivity Associated with Compound (Time of Peak) Amount Detected at Final Sampling Interval in Corresponding Study

Hydrolysis Aqueous Photolysis Soil Photolysis Aerobic Soil Anaerobic Aquatic Observed
in Lysimeter

Study

CSM * + 33 (31 days) a ,d 2 (31 days) a NR NA 14 (70 days) a Yes

ROC * + 18 (31 days) a ,e NR NR NA 31 (365 days) ab Yes

ODMC * + 14 (21 days) 12 (31 days) d 1 (31 days) a 3 (74 days) a NA 31 (365 days) ab Yes

TA * + 17 (31 days) a ,d NR 6 (74 days) NA 21 (365 days) a Yes

CPSU * NA NA NA NA 14 (56 days) a Yes

TU + NA NA 8 (74 days) NA NR Yes

OHTA NA NA NA NA NR Yes

DT 9 (31 days) a ,e NR 1 (74 days ) NA No

OHCSF NA NA NA NA NA NA

ODMTA NA NA NA NA <0.1 (all days) No

OHCSM NA NA NA NA <0.1 (all days) No

AB NA NA NA NA NA No

Abbreviations: NA=not analyzed; ND=not determined ; NR=not reported

a Peak at final sampling interval in some studies

. b Polar compounds were identified as either ODMC or ROC in the anaerobic aquatic study.

c See Appendix H for more information on source of information in this table.

d Observed at more than one pH but only major at pH 5.

e Observed at pH 5 only.

f Bold values with asterisk indicate the degradate is a major degradate. A plus (+) sign indicates that toxicity data are available for the degradate (see Appendix I ).



### 6.1. **Monitoring Data**

The following databases and sources were searched for monitoring information on chlorsulfuron on August 2, 2012:

• 

### The United States Geological Survey ( USGS ) National Water

- Quality Assessment ( NAWQA ) P rogram Data Warehouse ( http://infotrek.er.usgs.gov/traverse/f?p=NAWQA:HOME:1405517206944567 )

• 

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

• 

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

• 

### California Environmental Data Exchange Network (CEDEN; http://www.ceden.org/ )

### 17 No monitoring data are available

, as none of the databases looked for chlorsulfuron in water

.

R ecords for chlorsulfuron were available in the Storet/WQX Data Warehouse ( http://www.epa.gov/raf/publications/guidelines

- ecological

- risk

- assessment.htm ). These records will be completely reviewed when the risk assessment is completed.

**6.2. Clean Water Act** 

Chlorsulfuron is not identified 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 (TMDL) have been developed for the herbicide, based on information provided at http://iaspub.epa.gov/tmdl_waters10/attains_nation.tmdl_pollutant_detail?p_po llutant_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 Da ta in OPP’s Registration Review Risk Assessment and Management Process (see: http://www.epa.gov/oppfead1/cb/ppdc/2006/november06/session1

- sop.pdf ), in order to ensure they can be used quantitatively or qualitatively in pesticide risk assessments.

Aquatic life benchmarks for chlorsulfuron are reported in Table 6

. The correct benchmark for nonvascular aquatic plants ( 50 μg a.i./L ) should replace the previous value which was erroneously reported as 0.055 μg a.i./L due to a conversion error. Aquatic Life Benchmarks, developed by OPP 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 acceptabl e 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 corresponding 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

.

Table 6

. OPP Aquatic Life Benchmarks for Chlorsulfuron in μg a.i. /L 1

Fish Aquatic Invertebrates Nonvascular
Plants Vascular
Plants Office of Water Aquatic
Life Criteria

Acute Chronic Acute Chronic Acute Acute Maximum
Conc. Continuous
Conc. >125,000 32,000 >185,000 20,000 50 0.35

-- -- 1 The benchmarks at http://www.epa.gov/oppefed1/ecorisk_ders/aquatic_life_benchmark.htm are currently incorrect
and will be u pdated to be consistent with what is reported in this document.

### 18 

## 7. **Receptors**

Consistent wi th the process described in EFED’s 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 representative of broad taxonomic groups, are used to extrapolate to potential effects on a variety of spe cies (receptors) included under these taxonomic groupings. The most sensitive endpoint for each taxon is evaluated. Assessment endpoints include direct toxic effects on the survival, reproduction, and growth of terrestrial and aquatic life, as well as indirect effects, such as reduction in prey base and/or modification of
habitat. The evaluated taxa include freshwater fish, freshwater aquatic invertebrates, birds, small mammals, terrestrial invertebrates, algae, and terrestrial plants.

A cute and chronic toxicity data from studies submitted by pesticide registrants along with data
from the available open literature are used to evaluate potential direct and indirect effects on aquatic 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
literat ure 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 direct and
indirect effects of chlorsulfuron on biotic communities from loss of species that are sensitive to
the chemical

, and from changes in structure and functional characteristics of affected
communities.

Other sources of information, including use of the acute probit dose

- response relationship to establish the probability of an individual effect and the Ecological Incident Information System (EIIS), are con sul ted to further refine the characterization of potential ecological effects associated with exposure to chlorsulfuron . A summary of the curre ntly available ecotoxicity
information and the incident information for chlorsulfuron are provided below.
Table 7 provides a summary of the most sensitive surrogate species tested to characterize the potential acute and chronic ecological effects of chlorsulfuron

. Some of the values in the table
below h ave been revised since the last risk assessment based on a re

- evaluation of DERs for
chlorsulfuron for this problem formulation

.

Table 7

. Most Sensitive Species Evaluated for Potential Ecological Effects from
Chlorsulfuron

.

Exposure Scenario Species Acute Toxicity

-- Chronic Toxicity Citation
MRID Acute Toxicity
Classification

Birds 1

Acute (Dose

- based) Bobwhite Quail ( Colinus virginianus ) LD 50 > 5,000 mg a.i./kg

bw Acute 000352

- 63 (Acceptable) Practically

non

- t oxic

Acute (Dose

- based) Mallard D uck ( Anas platyrhynchos ) L D 50 >5,000 mg a.i./kg

diet Acute 000352

- 66 (Acceptable) Practically

non

- toxic

### 19 Exposure Scenario Species Acute Toxicity

-- Chronic Toxicity Citation
MRID Acute Toxicity
Classification

Chronic Bobwhite Quail ( Colinus virginianus ) NOAEC = 174 mg a.i./kg

diet
LOAEC (reproduction)

= 961 mg a.i./kg

- diet
Other sublethal effects One

- Generation Reproduction 426340

- 01 (Acceptable) --

Mammals

Acute Laboratory R at ( Rattus norvegicus ) LD 50 >5 ,50 0 mg a.i./kg

- bw Acute 000314

- 06 (Acceptable) Practically
Non

- toxic

Chronic NOAEL = 100 mg/kg

- diet
LOAEL (decreased bw in males) = 5 00 mg/kg

- diet 2

- Year
Chronic 000860

- 03 (Acceptable) --

Insects

Acute (contact) Honey B ee ( Apis mellifera ) LD 50 >25 μ g a.i./bee 48

- Hour
421299

- 02 (Acceptable) Practically
Non

- toxic

Freshwater fish 2

Acute

Rainbow Trout ( Oncorhynchus mykiss ) LC 50 > 300 mg a.i./L 96

- Hour
000352

- 58 (Acceptable) Practically
Non

- toxic

Chronic NOAEC = 32 mg a.i./L
LOAEC (length)

= 66 mg a.i./L
Other sublethal effects 77

- Day Early Life Stage
419764

- 05 (Acceptable) --

Freshwater Invertebrates

Acute Water Flea ( Daphnia

magna ) EC 50 >370 mg a.i./L 48

- Hour
000352

- 62 (Acceptable) Practically
Non

- toxic

Chronic NOAEC = 20 mg a.i./L LOAEC (reproduction) =36 mg/L 21

- Day
419764

- 04 and

419764

- 08 (Supplemental) 3 --

Estuarine/Marine Fish

Acute Sheepshead Minnow ( Cyprin o don

varigatus ) LC 50 > 980 mg a.i./L 96

- Hour
41 9764

- 01 (A cceptable) Practically
Non

- toxic

Chronic

-- -- --- Estuarine/Marine Invertebrates

Acute Mysid ( Americamysis
bahia ) LC 50 >89 mg a.i./L 96

- Hour
419764

- 02 (Acceptable) Slightly toxic

Terrestrial Plants

Monocot Onion ( Allium cepa ) EC 25 (dry wt) =
3 x 10 - 4 lb a.i./A

---- NOAEC (dry wt) = 4.5 x 10 - 5 lb a.i./A Tier 2 Seedling Emergence
463618

- 01 ( Supplemental ) 4 NA

EC 25 (dry wt) =
2.2 x 10 - 5 lb a.i./A

---- EC 05 (shoot height ) =

2.6 x 10 - 6 lb a.i./A Tier 2 Vegetative Vigor
463 268

- 01 ( Supplemental ) 5 NA

### 2 0 Exposure Scenario Species Acute Toxicity

-- Chronic Toxicity Citation
MRID Acute Toxicity
Classification

Dicot Pea ( Pisum sativum ) EC 25 (dry wt) = 2.2 x 10 - 5 lb
a.i./A

---- NOAEC = 1.8 x 10 - 4 lb
a.i./A Tier 2 Seedling Emergence
463618

- 01 ( Supplemental ) 4 NA

Rape ( Brassica rapa ) EC 25 (dry wt) = 1.0 x 10 - 5 lb a.i./A

---- EC 05 ( shoot height ) =

8.0 x 10 - 7 lb a.i./A Tier 2 Vegetative Vigor
46578942 (Supplemental) 5 NA

Aquatic Plants

Aquatic vascular
Plants Duckweed ( Lemna gibba ) EC 50 ( dry wt ) =
3.5 x 10 - 4 mg a.i./L

------- NOAEC (frond no. and dry wt) =
2.4 x 10 - 4 mg a.i./L 14

- Day Study
458329

- 01 (Supplemental) 6 NA

Non

- Vascular Aquatic Plants Green Algae ( Pseudokirchneriella subcapitata ) EC 50 ( cell density ) =
0.05 mg a.i./L

------- NOAEC (cell density) = 0.0094 mg a.i./L 120

- Hour
421868

- 01 (Supplemental) 7 NA

1 Birds represent surrogates for terrestrial

- phase amphibians and reptiles.

2 Freshwater fish may be surrogates for aquatic

- phase amphibians.

3 The chronic daphnid study was classified as supplemental due to a number of deficiencies and deviations.

4 The seedling emergence study is classified as supplemental due to plant crowding in pots and low light conditions.

5 The vegetative vigor study is classified as supplemental due to lack of a defined dose response curve and low light conditions. An extrapolated EC 05 was used in place of a NOAEC as the endpoint for chronic toxicity per EPA policy

. 6 This study is classified as supplemental because the study was conducted as a static test

. 7 This study is classified as supplemental as raw data were not available and the EC 50 was calculated using nominal
concentration values. This value was erroneously reported in the last risk assessment ( Table 9 ) and in EPA’s Aquatic Life
Benchmarks 7 as 0.000055 mg a.i./L ( Kiernan an d Young, 2005, DP330621 )

.



### 7.1. **Effects to Aquatic Organisms**

Summary

Table 7 summarizes the most sensitive endpoints used in risk assessment for aquatic organisms.
Based on these data

, chlorsulfuron is characterized as practically non

- toxic to freshwater and
marine/estuarine fish on an acute exposure basis. Many of the acute toxicity endpoints are non

definitive ( i.e., “greater than” values) as no mortalities or effects were observed at the highest
concentrations tested. Chlorsulfuron is conside red practically nontoxic to freshwater
invertebrates and slightly toxic to estuarine/marine invertebrates on an acute exposure basis

.

7 Benchmarks, developed for baseline risk assessments, are estimates of the concentrations below which pesticides

a re 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 corresponding 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

.

### 21 Compared to aquatic animals, aquatic plants are orders of magnitude more sensitive to
chlorsulfuron

. The endpoints and concentrations from these studies will be used to assess risk s to fish (and aquatic

- phase amphibians for which fish serve as surrogates) and aquatic invertebrates
from exposure to water containing chlorsulfuron residues fro m runoff and/or drift from treate d

areas

. No data have been submitted on toxicity of degradates of chlorsulfuron to aquatic organisms.

Fish Chlorsulfuron is practically non

- toxic to both freshwater fish and estuarine/marine fish on an acute exposure basis. Chronic exposure of rainbow tro ut ( Oncorhynchus mykiss ) to chlorsulfuron resulted in a NOAEC of 32 mg a.i./L (LOAEC = 66 mg a.i./L) based on decreased growth ( length )

, while a chronic study of sheepshead minnow ( Cyprindon varigatus ) resulted in a
NOAEC of 980 mg a.i./L (LOAEC> 980 mg a.i./L) based on decreased growth ( length )

.

Aquatic Invertebrates Chlorsulfuron is practically non

- toxic to freshwater invertebrates, and is slightly toxic to
estuarine /marine invertebrates on an acute exposure basis

. Chronic exposure to chlorsulfuron resulted in a NOAEC of 20 mg a.i./L (LOAEC=36 mg a.i./L) for water flea ( Daphnia magna )
based on total decreased growth ( length ) . A chronic toxicity study with marine/estuarine
invertebrates is not available

.

Aquatic Plants Studies were submitted for a freshwater vascular plant (duckweed, Lemna gibba ), and for the nonvascular aquatic plant green algae ( Pseudokirchneriella subcapitata, formerly called Selenastrum capricornutum ), a freshwater blue

- green (cyanobacteria) algae ( Anabaena flos

aquae ), a freshwater diatom ( Navicula pelliculosa ), and a marine diatom ( Skeletonema costatum ) exposed to the technical chlorsulfuron

.

Exposure of duckweed to chlorsulfuron technical resulted in an 7

- day EC 50 

### value of 0.35 μg
a.i./L and a NOAEC of 0.24 μg a.i./L . These values will be use d in assessing potential risk s of
chlorsulfuron to aquatic vascular plants.

The most sensitive 96

- hr EC 50 

### valu e for nonvascular plants is 50 μg a.i./L; the associated
NOAEC is 9.4 μg a.i./L for reductions in cell density. Green algae are the most sensitive aquatic nonvascular plant s to chlorsulfuron

.

**7.2. Effects to Terrestrial Organisms** 

Available ecotoxicity data indicate that chlorsulfuron is characterized as practically non

- toxic to mammals and birds on an acute exposure basis and the compound is practically nontoxic to birds on an a subacute dietary exposure basis as well . Many of the acute toxicity endpoints are non

definitive ( i.e., “greater than” values) as no mortalities or to xic effects were observed at the highest levels tested. Compared to terrestrial animals, plants are orders of magnitude more
sensitive to chlorsulfuron. The endpoints and concentrations from these studies will be used to
assess risk to mammals and birds from direct application of chlorsulfuron to treated areas and
from off

- target spray drift

. Table 7 summarizes the most sensitive endpoints used in risk

### 22 assessment for terrestrial animals. N o data have been submitted for degradates of chlorsulfuron

on toxi city to terrestrial organisms.

The acute and chronic toxicity values associated with chlorsulfuron exposure to mammals, birds, and terrestrial plants are summarized in Appendix C

.

Mammals A toxicity study in Norway rats ( Rattus norvegicus ) indicates that chlorsulfuron is practically

non

- toxic to rats on an acute oral exposure basis with an LD 50 

### >5 ,50 0 mg/kg

- bw

, the highest
dose tested (MRID 000314

- 06 ).

A combined chronic/carcinogenicity 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 is 5 mg/kg/day or 100 mg a.i. /kg

- diet, and the LOAEL is 25

mg a.i. /kg/day or 500 mg a.i./kg

- diet, b ased on decreased body weight gain in females (MRID
000860

- 03 ).

Birds
A s tud y of acute toxicity in bobwhite quail ( Colinus virginianus ) indicate s that chlorsulfuron is practically non

- toxic to bobwhite quail on an acute oral exposure basis (LD 50 

### > 5,000 mg

a

. i

. /kg

- bw , highest dose tested ). O n a subacute dietary exposure basis , in mallard ducks ( Anas platyrhynchos ), chlorsulfuron resulted in an LC 50 

### > 5,000 mg a

. i

. /kg

- diet

, the highest dose tested (MRID 000352

- 66 )

.

No treatment

- related effects on adult b ird mortality, food consumption, body weight, or reproductive parameters and no clinical signs or treatment

- related effects in offspring survival or body weight were observed in studies of the chronic toxicity of chlorsulfuron for mallard duck or
bobwhite quail. The NOAEC for mallard duck is >961 mg a.i./kg

- diet and 961 mg a.i./kg

- diet for bobwhite quail (MRID 426340

- 01)

.

N o chronic toxicity studies for chlorsulfuron formulations or chlorsulfuron degradates in avian or mammal species have been submitted

. In the absence of other data, the toxicity data for birds serves as surrogate information for the effects of chlorsulfuron on reptiles and terrestrial

- phase amphibians.

Terrestrial Invertebrates Results of available toxicity studies indicate that chlorsul furon is practically non

- toxic to honey
bees ( Apis mellifera ) on an acute contact exposure basis ( LD 50 

### > 25 μg a.i./bee ; MRID 000314

- 06)

.

Terrestrial Plants Results of the seedling emergence study identif y onion ( Allium cepa ) as the most sensitive

monoco t yled o nous plant species and pea ( Pisum sativum ) as the most sensitive dicot yledonous plants , with decreased dry weight as the most sensitive endpoint affected. The NOAEC and
EC 25 

### value s of 0.000045 lbs a.i./A and 0.0003 lbs a.i./A, respectively, for onion , and 0.0 0018
lbs a.i./A and 0.0 00022 lbs a.i./A, respectively, for pea will be used to assess the effects of

### 23 exposure to chlorsulfuron on seedling emergence in non

- listed and listed terrestrial plants (MRID 463618

- 01)

.

Results of the Tier II vegetative v igor studies identify onion ( Allium cepa ) as the most sensitive
monocot and rape ( B rassica rapa ) as the most sensitive dicot, with dry weight and shoot height as the most sensitive endpoint s affected for onion and rape, respectively . The EC 05 

### (used in place
of a NOAEC for listed species assessment ) and EC 25 

### values of 0.00 000 26 lbs a.i./A and
0.00 0022 lbs a.i./A, respectively, for onion, and the EC 05 

### and EC 25 

### value s of 0.000 00 0 8 lbs
a.i./A and 0.00001 lb a.i./A , respectively, for rape were the most sensitive endpoints for
chlorsulfuron on vegetative vigor in non

- listed and listed terrestrial plants (MRID 463268

- 01)

.

A series of special stud ies on the reproductive toxicity of chlorsulfuron on soybeans ( Glycine

max ) was submitted by DuPont and two studies were recently review ed by EFED. Based on the
results of th e stud ies

, it was concluded that the inhibitory concentration for 25% of the plants tested ( IC 25 

### or EC 25 

### ) determined in a typical guideline vegetative vigor study ( 850.4150 ) is protective of inhibitory effects of exposure at reproductive stages. The studies were classified as acceptable (D404866)

. As a result of the analysis of this study, no further data for chlorsulfuron reproductive effects on terrestrial plants are needed f or risk assessment purposes ( MRID 487769

- 02 and 487769

- 03 )

.

EFED's Plant Technical Team (PTT) conducted an analysis of available SU plant reproduction data from the open literature and the registrant

- submitted data for chlorsulfuron and concluded
that da ta from the 850.4150 vegetative vigor guideline study are sufficiently protective of potential impacts to plant reproduction. Acetolactate synthase (ALS) inhibitors primarily affect metabolically

- active meristem tissues. When plants are exposed at a young, vigorously growing
life

- stage, effects are expressed primarily as inhibition of vegetative growth ( i.e. biomass, shoot length). As plants mature these effects are less pronounced. However, as plants enter their reproductive life

- stage, the metabolically

- active tissue will include flower and seed production. Plants exposed to SU herbicides during the reproductive life stage are likely to exhibit adverse effects on reproduction, generally expressed as reduced seed number or reduced seed weight.
Based on the latest data analysis, these effects are expected to occur at similar concentrations to those effects determined in the guideline vegetative vigor studies (850.4150) so further data are not requested at this time.

**7.3. Degradate Toxicity** 

Toxicity and risk from chlorsulfuron degrada t es is an area of uncertainty. There is an exposure concern for these degradates due to the potential mobility and formation rates relative to the parent ch lorsulfuron

. Degradates are discussed in more detail in Section 11 , Stressors of
Concern.

**7.4. Ecological Incidents** 

A preliminary review was made on August 13

, 2012 of the Incident Data System (IDS) and the Ecological Incident Information System (EIIS, version 2.1.1), which are maintained by the

### 24 Agency’s Office of Pesticide Programs, and the Avian Monitoring Information System (AIMS), which is maintained by the American Bird Conservancy.

In addition to individual incidents recorded in EIIS, incidents may be reported to the Agency in aggregated incident reports. Pesticide registrants report certain types of incidents to the Agency as aggregate counts of incidents occurring per product per quarter. Ec ological incidents reported in aggregate reports include those categorized as “minor fish and wildlife” (W

- B), “minor plant” (P

- B), and “other nontarget” (ONT) incidents. “Other nontarget” incidents include reports of
adverse effects to insects and other terrestrial invertebrates. For chlorsulfuron

, 9 plant damage incidents were reported in the EIIS database (accessed July 19, 2012 ) and 7 separate aggregate incidents (6 plant damage) were reported in the IDS database (accessed August 13, 2012)

. No
inciden ts involving birds have been reported for chlorsulfuron to the AIMS database (accessed August 13, 2012). A summary of plant incidences reported for chlorsulfuron is provided below.

As recently as September, 2011, plant damage was reported as a result of c hlorsulfuron use. Incidents are reported in the Aggregate Incident Summary Report for chlorsulfuron for several recent years: 2011 ( two reported incidents

- both for plant damage) , 2010 (three reported
incidents

- one for plant damage, two for wildlife) , 2008 (one reported incident for plant damage)
and 2003 (one reported incident for plant damage)

.

The EIIS contains nine incident reports. The most recent of these incidents (IO17719

- 001) occurred in July , 200 6 in Shasta County, California, where 126 acres of an agricultural area were
affected due to ‘possible’ exposure from chlorsulfuron . In June, 2006, in Whitman County, Washington, an agricultural area was affected by exposure to chlorsulfuron from a right

- of

- way spraying, although the incident is listed as “unlikely” (I021457

- 012). In April, 2004 in Multnomah County, Oregon, a right

- of

- way spraying of chlorsulfuron was considered “probable” and caused $40,000 of damage (I015576

- 001)

. In August, 2005 in Sutter County, California, more than 75 trees were dama ged by a “probable” exposure to chlorsulfuron from a right

- of

- way treatment (I016671

- 001).

I n June 1998 in Benton County, WA, an orchard bound on three sides by dry land' wheat reported four years of reduced Bing cherry production (I013884

- 012) . The Wash ington State Department of Agriculture investigated, but the cause remains unknown and the investigation

was not continued. Chlorsulfuron was one of the herbicides used on the wheat fields. Another incident occurred in 1997 (I0 13882

- 035), where potatoes were possibly affected by tank contamination by chlorsulfuron near Walla Walla, WA. Also in 1997, leaf spots in cherry and apple orchards in Douglas County, WA were reported (I0 13 883

- 003). Chlorsulfuron and 2,4

- D
were used on nearby wheat fields and the spots were thought by investigators to be due to
chlorsulfuron drift. In 1994, a farmer in KY reported damage to tobacco seedlings after 2,4

- D
and chlorsulf u ron were used on a nearby road right

- of

- way (1001473

- 001). That the damage (chlorosis and growth ce ssation) was due to chlorsulfuron was determined to be "possible". The last incident in the database (10002 30

- 001) is reported to be from s pring 1977 and was reported to the Agency in 1992. Peach trees in a Benton, WA orchard were severely damaged
and cher ry and prune trees were damaged to a lesser degree (pear trees were unaffected). It was
determined that the damage was "definitely due" to chlorsulfuron, which h ad been applied to a nearby whea t field. The date of 1977 raised questions, as chlorsulfuron wa s not registered until

### 25 1982. The i nc ident was reported by George Abel, Pesticide and Toxic Substance Branch, US EPA, Region 101 1200 Sixth Avenue, Seattle, WA 98101. An investigation into this anomaly suggests that the correct date of this incident was likely 1987, according Cliff Weed, Compliance Program Manag e r, Pesticide Management Division, Washington State Department of Agriculture (personal co mm unication, March 09, 2005). Weed, an employee since 1985, recalls that numerous incidents of crop damage, most allegedly due to chlorsulf u ron, were investigated in the spring of, 1987. He specifically recalls an incident involving peaches; however, as the Department routinly discards records after seven years, no known records from that time exist.
The Horse Heaven Hills lawsuits are not in the Agency's EIIS database, but the alleged incidents
of chlorsulf ur on drift were investigated by Fletcher (1991). An orchard suffered sev e ral years of reduced yield in the late 1980s in an area proximal to wheat farms at H orse Heaven Hills, where
herbicides w e re regularly used. While the reduced yields and plant damage were not n oted
before the use of chlorsulfuron in the area, the investigation results were inconclusive.

In the risk assessment, these databases will be che cked again and any incidents reported will be further evaluated to determine if the reported incidents represent current patterns of use for
chlorsulfuron . The absence of reported incidents should not be construed as the absence of
incidents. Incident re ports for non

- target organisms typically provide information only on mortality events and plant damage. Sublethal effects in organisms such as abnormal behavior, reduced growth and/or impaired reproduction are rarely reported, except for phytotoxic effect s in terrestrial plants.



## 8. **Evaluation of Non**

**- definitive Toxicity Values** 

Many of the acute terrestrial and aquatic animal studies resulted in non

- definitive toxicity values

, meaning that the actual toxicity of the compound is “greater than” the LC 50 

### , and t hus, 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.

Aquatic Animals
In an effort to determine whether additional data are n eeded to evaluate risk to non

- target aquatic fish and invertebrates, EFED conducted a comparison of the non

- definitive toxicity value to the estimated aquatic conce ntration (EEC)

. For acute exposure to listed aquatic organisms, the EEC
would have to be 46 8 times higher than the previous EEC to approach a risk of concern for aquatic animals.

Birds and Mammals
For acute exposure to listed birds , the EEC would have to be 15 times higher than the previous
EEC. For acute exposure to listed mammals, the EEC wou ld have to be 20 times higher than the previous EEC

. Therefore, the risk to birds and mammals is presumed to be low and additional
data are not needed at this time.

### 26 

## 9. **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 development of a nation

- wide ecological risk assessment. However, in general terms, terrestrial ecosystems potentially at risk could include the treated
field and immediately adjacent areas that may receive drift or runoff. Areas adjacent to the treated field could include cultivated fields, fencerows and hedgerows, meadows, fallow fields or grasslands, woodlands, riparian habitats, and other uncultivated area s.

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



## 10. **Assessment Endpoints**

Assessment endpoints represent the actual environmental value that is to be protected, defined by an ecological entity (species, community, or other entity) and its attribute or characteristics ( USEPA, 1998 ) . For chlorsulfuron , the ecological entities include the following: birds, reptiles,
terrestrial

- phase amphibians, mammals, freshwater fish, freshwater aquatic

- phase amphibians and invertebrates, estuari ne/marine fish and invertebrates, terrestrial plants, insects, aquatic plants, and algae. The attributes for each of these entities include growth, reproduction, and
survival.



## 11. **Identification of Stressors of Concern** 

The transformation products important for consideration for exposure include:

• the major degradates and degradates observed in lysimeter studies (ring

- opened chlorsulfuron, o

- desmethylchlorsulfuron, 2

- chlorophenylsulfonylurea, chlorosulfonamide, triazine amine),

• degradates observed in lysimet er studies (hydroxy triazine amine and triazine urea),

• and the minor degradate dihydroxy triazine

.

Dihydroxy triazine was observed at 9% applied radioactivity in the hydrolysis study at pH 5 on the final sampling interval and is assumed to be essential ly a major degradate because if the study was continued it is possible that it would have been observed at 10% or higher applied radioactivity

. All of these degradates are assumed to have the potential to occur in the natural
environment and to have some potential for exposure

. Appendix H provides structure, identity, and fate information on the transformation products. O ther transformation products o r higher percentages of transformation products could be observed in fate laboratory studies submitted in
the future to address data gaps

. These transformation products would have the potential to be observed in the environment based on registered uses. V alid a erobic soil and aerobic aquatic metabolism studies are not available and are particularly important studies in understanding the environmental fate and transformation products that are likely to be observed in the natural
environment.

### 27 Toxicity data on chlorsulfuron degradation products have not been submitted to EFED; however, data are available from other sources. These data were used to prioritize the residues of concern for ecological risk assessment. As these prioritizations were made based on unreviewed data, these determinations may be revisited when data are fully reviewed. It is recommended that these data be submitted to EFED to support the registration review of chlorsulfuron and to fully support determinations on the potent ial residues of concern for chlorsulfuron.

Residues of Concern for Drinking Water Consumed by Humans

The most recent drinking water assessment completed for chlorsulfuron was in support of the Tolerance Registration Eligibility Decision ( TRED ) and was co mpleted in 2002 ( Shanaman, 2002, D266073 ) . A Tier 1 risk assessment was completed. The only residue considered in the assessment was the parent chlorsulfuron. In 1995 the Health Effect Division (HED) Metabolism Committee Meeting (MA RC) considered the residues of concern for residues for dietary items ( e.g ., in plants and commodities) ( Abbots, 1995a , 1995b ) . The committee determined that the residue to be regulated in plants and animal commodities was parent chlorsulfuron only. It is anticipated that the r esidues of concern for human health drinking water will be revisited as new
fate data ( e.g ., aerobic and anaerobic metabolism data and an aquatic field dissipation study) that could influence the decision on the potential residues of concern for human hea lth drinking water
become available.

Residues of Concern for Ecological Risk Assessment

The residues of concern for exposure to aquatic organisms are assumed to be chlorsulfuron , o

desmethyl chlorsulfuron , ring

- opened chlorsulfuron, and 2

- chlorophenylsulfonyl urea. These degradates retain the sulfonylurea group and/or have data that suggest that chronic toxicity to daphnid will be within an order of magnitude of the parent. These residues are expected to have the greatest impact on the risk assessment for aquatic plants as sulfonylureas are highly toxic to plants and fate data will influence exposure estimates for aquatic plants

. Structural activity relationships combined with exposure estimates indicate that d egradates that are in a s eparate chemical class are not significantly more toxic than the parent such that they would change the risk conclusions from evaluating risk due to exposure to the parent alone. The re fore, they were
determined to be not of concern. Justification s for th e determinations on the ecological residues
of concern are described in Appendix I

.

Method of Estimating Exposure and Evaluating Risk for Degradate s

To estimate exposure to compounds assumed to have toxicity similar to that of the parent ( e.g .,
o

- desmethyl chlorsulfuron, ring

- opened chlorsulfuron, and 2

- chlorophenylsulfonyl urea for the ecological risk assessment ), a total toxic residue (TTR) approa ch will be used

. 8 

### This entail s summing the residues observed in fate studies

, and then estimating degradation rates based on
the total summed residues. The resulting TTR degradation rates will then be used to estimate

exposure s , in place of degradation rates based on parent alone. Data on organic

- carbon
normalized distribution coefficients are requested for degradates observed in high percentages in

8 Justifications for the determinations on the ecological residues of concern are described in Appendix I

.

### 28 the fate studies ( ring

- opened chlorsulfuron and 2

- chlorophenylsulfonyl urea ) 9



### . In the TTR approach, the lowest K OC 

### will be used in modeling , under the assumption that this provides the most conservative estimate of residue mobility

. M odeled total toxic residue concentration s will then be compared to the most sensitive toxicity endpo ints for the parent or residue of concern

. Table 8 summarizes the approaches to be used for assessing risk s to various taxa from different
transformat ion products

.

Table 8 . Summary of residues of concern for different classes of organisms

Transformation Product Is the transformation product a residue of concern? If yes, assessment method. Aquatic
Animals Aquatic
Plants Terrestrial
Vertebrates Terrestrial
Invertebrates Terrestrial
Plants
O

- desmethyl chlorsulfuron Yes

- TTR 1 Yes

- TTR 1 Yes

- TTR 1, 2 Yes

- TTR 1, 2 Yes

- TTR 1 ,2

R ing

- opened chlorsulfuron Yes

- TTR 1 Yes

- TTR 1 Yes

- TTR 1,2 Yes

- TTR 1,2 Yes

- TTR 1,2

2

- C hlorophenylsulfonylurea Yes

- TTR 1 Yes

- TTR 1 Yes

- TTR 1,2 Yes

- TTR 1,2 Yes

- TTR 1,2

Triazine amine No No No No No
Triazine urea No No No No No Hydroxyl triazine amine No No No No No Dihydoxy triazine No No No No No
Chlorosulfonamide No No No No No Hydroxy chlorosulfonamide No 3 No 3 No 3 No 3 No 3

O

- desmthyl triazine amine No 3 No 3 No 3 No 3 No 3

5

- hydroxy chlorsulfuron No 3 No 3 No 3 No 3 No 3 Acetylbiuret No 3 No 3 No 3 No 3 No 3 Abbreviation: TTR= Total toxic residue approach
1 Residues included in the TTR approach for these taxa are the parent and o

- desmethyl chlorsulfuron, ring

opened chlorsulfuron, and 2

- chlorosulfonylurea.
2 As these degradates are assumed to have similar toxicity to the parent and exposure estimates are not related to the fate data, the presence of these degradates does 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 degrad ates could influence the estimate of exposure, this approach will be
revisited.
3 Determined not to be a residue of concern based on a low likelihood of exposure as this degradate was not observed in laboratory or field studies. This may be re

- evaluated if this residue is observed in fate studies
in the future.



### For terrestrial organisms , residues of concern are the same as residues of concern identified for aquatic organisms

. While the TTR approach was identified as the method to evaluate risk due to exposure to chlorsulfuron and major degradates, fate data are not used in T

- REX (unless foliar dissipation data are available 10 

### ) and Terrplant , the model s used to estimate terrestrial exp osure. Therefore, use of the TTR approach for terrestrial animals will not change the ir exposure estimates . If terrestrial exposure estimation methods change in the future so as to incorporate
environmental fate data , a more complete analysis of exposure s to residues of concern for
terrestrial animals may be possible

.

9 Batch equilibrium data for o

- desmethylchlorsulfuron is not requested. While loss of a methyl group is likely to influence the measured sorption coefficients, it is assumed that the measu red values would be similar to those measured for chlorsulfuron. EPIWEB version 4.1 predicted K OC values of 124, 423, and 1 L/kg

- organic carbon for parent, ring opened chlorsulfuron, and 2

- chlorophenylsulfonylurea, respectively.

10 Foliar dissipation data are not available for chlorsulfuron.

### 29 Mixtures

Evaluation of pesticide environmental mixtures is beyond the scope of this assessment because of myriad factors that cannot be quantified based on the available data. Those fact ors include identification of other possible co

- contaminants and their concentrations, differences in the pattern and duration of exposure among contaminants, and the differential effects of other physical/chemical characteristics 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 ack nowledged that not considering mixtures could over

- or under

- estimate risks depending on the type of interaction and factors discussed above. The assessment will, however, analyze the toxicity of formulated products (including formulations 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. Twenty

two products also have one of the following active ingredie nts : aminocyclopyrachlor,
flucarbazone

- sodium, metsulfuron, sulfentrazone, or sulfameturon ( Appendix A )

. Flucarbazone

- sodium , metsulfuron, and sulfentrazone are herbicides that like chlorsulfuron act on acetolactate synthetase (ALS) ( Ware and Whitacre, 200 4 ) . Aminocyclopyrachlor is an pyrimidine carboxylic acid class herbicide ( Ullagadi et al. , 2010 ) and sulfentrazone is an anilide
herbicide ; Aminocyclopyrachlor and sulfentrazone have different modes of action from
chlorsulfuron ( Wood, 2009 )

. If use of any of these products result in spray drift to a water body, acute aquatic toxicity data on a representative typical end

- use product should be available for that mixture of ingredients. Additionally, terrestrial plant toxicity data should be available for a typical e nd

- use product containing the combination of active ingredients.



## 12. **Risk Hypothesis**

A risk hypothesis describes the predicted relationship among the stressor, exposure, and assessment endpoint response along with the rationale for their selection. For chlorsulufuron, the following ecological risk hypothesis is being employed for this national

- level ecological risk

assessment:

Given the uses of chlorsulfuron and its environmental fate properties, there is a likelihood of exposure to non

- target terrestrial and/or aquatic organisms. When used in accordance with the label, chlorsulfuron and its degradates may result in adverse effects upon the survival, growth, and reproduction of non

- target terrestrial and/or aquatic organisms

. These nontarget o rganisms may include Federally

- listed threatened and endangered species. Based on the previous risk assessment and analysis supporting this problem
formulation , direct effects are likely for aquatic and terrestrial plants

, and indirect effects may result for all other taxa due to direct effects on plants.

### 30 

## 13. **Exposure Pathways of Concern , Models, and Toxicity Endpoints** 

The environmental fate properties of chlorsulfuron and use patterns indicate that direct spray, spray drift, leaching to ground water, and runoff represent important transport pathways. Chlorsulfuron may also be introduced into water bodies including streams, rivers, ponds,
marshes

, etc., when rising water ( i

. e. as a result of flooding) inundates terrestrial areas where the
chemical has be en applied. Potential exposure pathways and justifications for including them or
not in the risk assessment are discussed below. Table 9 summarizes the exposure pathways, toxicity endpoints, and models used in the risk assessment. More information on the exposure models is provided in Section 14.1 . More information on the endpoints that will be used in the
assessment is available in Secti on 7

.

Considerations in Defining Exposure Pathways

Although chlorsulfuron may be applied as a granule or as a flowable liquid, spray drift is only expected to re sult in significant exposure with broadcast applications (both aerial and ground spray) of the flowable liquid formulations. Dry formulations that are applied as a flowable liquid may result in significant spray drift exposure. Applications with hand

- hel d sprayers are assumed to result in minimal spray drift.

Exposure to Birds and Mammals via Inhalation and Drinking Water

Using currently available aquatic toxicity data for animals, t he Screening Tool for Inhalation Risk (STIR) version 1.0 (November 23 , 2010) indicates that exposure via inhalation is not likely

to present a risk concern for birds and mammals ( Appendix D ). These results combined with
the low rate of volatilization indicate that long

- range transport in the vapor phase is not an

exposure pathway of concern. The Screening Imbibition Program (SIP) version 1.0, August 19, 2010 indicates that chlorsulfuron has the potential to be present in drinking water at sufficiently high concentrations to result in a risk concern ( Appendix D ). 11 

### This is a highly conservative
evaluation

, as SIP assumes that concentrations in drinking water could be at the level of solubility

. A dditionally , non

- definitive acute endpoints for mammals and birds and definitive chronic endpoints were used in the mode l. Given the low toxicity of chlorsulfuron to animals it
is likely that risk to birds and mammals exposed to residues in drinking water will be at acceptable levels.

Biocon centration, Exposure in Sediment , and Leaching to Groundwater

Chlorsulfuron’s K OA 

### , K OW 

### , and BCF indicate that chlorsulfuron is not likely to bioconcentrate or bioaccumulate in aquatic or terrestrial organisms. Freundlich o rganic

- carbon normalized distribution coefficients (K F OC 

### ) range from 8 to 31 (mg/L)(mg/kg) - 1/n

, 

### indicating that ch lorsulfuron has the potential to leach into groundwater and that sediment does not need to be considered as a separate exposure pathway for aquatic invertebrates. Finally, surface and ground water

11 At pH 7 and above it is a potential concern for mammals and birds due to both acute and chronic exposure. At pH 5, it is a potential concern for birds via acute and chronic exposure and a potential concern for mamma ls due to chronic exposure only.

### 31 contaminated with chlorsulfuron has the potential to be used as irrigation water

, which would
result in exposure to terrestrial plants ( Kiernan and Young, 2005, DP330621 )

.

Table 9

. Summary of exposure pathways, endpoints, and models used in risk assessment.

Assessed Group Endpoints Evaluated Transport and Exposure Pathway Method of Estimating Exposure

Aquatic
Vertebrates Acute: 96

- hr LC 50 Chronic: NOAEC Spray drift and runoff to
water column

Rise of water after application to dry
surface in
wetlands/marsh/ etc

.

Sediment does not need

to be considered as a

separate exposure pathway PRZM/EXAM S , AgDRIFT or AgDISP

Method to be determined Aquatic
Invertebrates Acute: 48

- hr LC 50 / E C 50 Chronic: NOAEC

Aquatic
Plants EC 50

Terrestrial
Vertebrates Acute : O ral LD 50 / DietaryLC 50 Chronic: NOAEC Spray Drift and direct

spray to

Residues on foliage

Residues in drinking

water

Inhalation not a pathway
of concern

Bioconcentration in aquatic organisms not a

pathway of concern AgDRIFT or AgDISP

TREX , AgDRIFT or AgDISP

Method to be determined

Terrestrial
Invertebrates Method under development

Terrestrial
Plants EC 25

, EC 05, and
NOAEC Runoff (vegetative vigor and seedling emergence) and Spray Drift (vegetative vigor)

Water used as irrigation

water TERRPLANT and AgDRIFT or AgDISP

SCIGROW and PRZM/EXAMs

Human
Health Drinking
Water See Human Health Toxicity Assessment Surface Water

Ground Water PRZM/EXAMs

SCIGROW



## 14. **Analysis Plan**

In order to address the risk hypothesis, the potential for adverse effects on the environment is
estimated. T he registered use s , environmental fate, an d ecological effects of chlorsulfuron are characterized and integrated to assess the risks. This is accomplished using a risk quotient (ratio of exposure concentration to effects concentration) appro ach. Although risk is often defined as

### 32 the likelihood and magnitude of adverse ecological effects, the risk quotient

- based approach does not provide a quantitative estimate of likelihood and/or magnitude of an adverse effect. However, as outlined in the Overview Document ( USEPA, 2004 ) , the likelihood of effects to individual organisms from particular uses of chlorsulfuron is estimated using the probit dose

response slope and either the level of concern (discussed below) or actual calculated risk quotient
value.

This analysis plan will be revisited

, and may be revised depending upon information submitted by stakeholders and the public in response to the opening of the Registration Review docket for
chlorsulfuron

.

**14.1. Measures of Exposure** 

EFED will use standard available models to evaluate potential exposures to aquatic and terrestrial organisms as described at http://www.epa.gov/pesticides/science/models_db.htm

. The versions used by the Agency at the time the risk assessment is completed will be used in the

assessment.

14.1.A. Exposure in the Aquatic Environment

Exposure to organisms in surface water will be estimated using PRZM/EXAMs.

According to the EFED Table 1 LUIS report (dated 08/03/2012), chlorsulfuron may be used in airports and landing fields, commercial and industrial lawns, commercial storages and warehouses, outdoor industrial construction areas, nonagricultural rights

- of

wa ys/fencerows/hedgerows, nonagricultural uncultivated areas, ornamental lawns/turf, paved

areas. EFED is currently exploring methods to assess urban and residential uses of pesticides on a national basis. At the present time, EFED considers the use of the impervious surface scenario (a PRZM modeling scenario) as the most suitable available modeling approach for impervious runoff. The PRZM impervious scenario may be used in tier II PRZM/EXAMS along with a residential or other suitable scenario such as righ ts

- of

- way (ROW) to obtain EECs. The conceptual model for the residential scenario integrates simultaneous modeling of the individual use scenario with an impervious scenario. This approach assumes that no watershed is completely covered by either 1⁄4

- acre lot s (the basis for the residential scenario) or undeveloped land (the basis for the ROW scenario) for residential and ROW use patterns; therefore, differential amounts of runoff will occur within the watershed. The impervious scenario was developed to re present the paved areas within a watershed not including roads, parking lots, sidewalks, and buildings outside the 1⁄4

- acre lot (the 1⁄4

- acre lot scenario accounts for impervious surfaces such as buildings within the represented area). By modeling a separate scenario for impervious surfaces, it is also possible to estimate that amount of exposure that could occur when the pesticide is oversprayed onto this surface. Using two scenarios in tandem requires post

- processing of the modeled output in order to derive a weighted EEC that represents the contribution of both the pervious ( i.e. , residential and ROW scenarios) and the impervious surfaces. Exposure from both scenarios can also be weighted and aggregated. The daily time
series from each model run from the time series file (NAME_TS.out) generated from the PRZM graphical user interface (PE5.pl) residential and impervious surface scenarios are combined

### 33 using Microsoft ® 

### EXCEL. The time series data are weighted based on percentage of impervious
surface and perv ious surface , the percentage of the pervious and impervious surface treated, and an adjusted time series is created. Rolling averages for the relevant durations of exposure ( e.g. , 21

- day and 60

- day averages) are calculated, and the relevant one

- in

- ten yea r return EEC is generated from these distributions.

Concentrations of chlorsulfuron and associated residues ( o

- desmethylchlorsulfuron, ring

- opened chlorsulfuron, and 2

- chlorosulfonylurea for ecological risk assessment

, and parent chlorsulfuron
for human h ealth drinking water ) in ground water will be estimated using EFED's Tier I aquatic model SCIGROW (Screening Concentration In Groun d Water) ( USEPA, 2011 )

.

In addition to modeling estimates, available monitoring data will be evaluated. Monitoring data will include those collected/reported by states as well as other federal departments/agencie s ( e.g ., USGS National Water Quality Assessment; http://water.usgs.gov/nawqa/ )

.

A downstream dilution model (under development) may be used to identify areas downstream
from use area s that may have EECs high enough to result in risk concern s . This analy sis will be used to define potential area s of effects for list ed species.

14.1.B. Exposure to Terrestrial Animals

Exposure estimates for terrestrial animals assumed to be in the target application area or in an area exposed to spray drift will be derived us ing the T

- REX model (version 1.4.1, 10/09/2008) ( USEPA, 2008 )

. This model incorporates the Kenaga nomograph, as modified by Fletcher et al. (J. S. Fletcher et al., 1994 ) (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
fie ld measurements ( 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, including information on 11 8 species of plants, 121 pesticides, and 17 chemical classes ( J. S.
Fletcher et al. , 1994 )

. T

- REX generates exposure estimates based on these data, and assuming a 35

- day foliar dissipation half

- life in the absence of Foliar Residue Di ssipation data.

For applications of granules containing chlorsulfuron , acute exposure and risks to terrestrial
wildlife are estimated with the conceptual approach and the LD 50 

### /ft 2 

### method employed in the
model T

- REX. Terrestrial EECs will be calculated based on an estim ation of loadings of pesticide per unit area (expressed in terms of mg a

. i

. /ft 2 

### ) for a single application (multiple applications are not accounted for in this analysis); the a vailable mass of pesticide per square foot is then compared to t he acute oral dose for toxicity (LD 50 

### values adjusted for body weight and percent body weight consumed) to derive r isk quotients for birds and/or mammals. Acute
and c hronic exposures for granules are also estimated based on the direct consu m ption of

granu les

.

14.1.C. Exposure to Terrestrial Plants

EECs for terrestrial plants inhabiting dry and wetland areas are derived using the program TERRPLANT (version 1.2.2, 12/26/2006) ( USEPA, 2006 ) . This model uses estimates of

### 34 pesticides in runoff and spray drift to calculate EECs. EECs are based upon solubility, application rate and minimum incorporation dep th. AgDRIFT may also be used to assess exposure to spray drift.

Non

- target crops may be exposed to contaminated i rrigation waters from surface water or shallow ground water containing chlorsulfuron . The potential risks to plants when exposed to irrigation water contaminated with chlorsulfuron 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

, whi le that for surface water will be calculated using PRZM and EXAMS
results from the scenario yielding the highest EECs. Comparisons will be made to the most sensitive endpoint from the vegetative vigor study

, under the assum ption that irrigation water
does not run off or infiltrate, but stays ponded at the surface

.

14.1.D. Exposure to Spray Drift

Two spray drift models, AgDISP and AgDRIFT, are used to assess exposures of aquatic and terrestrial organisms to chlorsulfuron deposited in terrestrial and aquatic habi tats by spray drift. AgDrift ( Spray Drift Task Force Spray Software ) is the model most commonly used by EFED to simulate spray drift into terrestrial and aquatic environments. AgDISP ( Teske and Curbishley,
2003 ) is used when a parameter needs to be modeled that is not available in AgDRIFT. Spray drift analysis will be an important part of the analysis in defining the potential area of effects for endangered species.

**14.2. Measures of Effect** 

Ecological effect s data are used as measures of dir ect and indirect effects to biological receptors

. Data are obtained from registrant

- submitted studies or from literature studies identified by
ECOTOX. The ECOTOXicology database (ECOTOX) will be searched in order to provi de more ecological effects data to bridge existing data gaps. ECOTOX is a source for locating single chemical toxicity data and potential chemical mixture toxicity data for aquatic life, terrestrial plants, and wildlife. ECOTOX was created and is maintai ned by the USEPA, Office of Research and Development, and the National Health and Environmental Effects Research Laboratory's Mid

- Continent Ecology Division ( USEPA, 2009a )

.

Information on the potential effects of chlorsulfuron on non

- target animals is also collected from
the Incident Data System (IDS), the Ecologic al Incident Information System (EIIS , version
2.1.1 ) ( USEPA, 2012b ) . The EIIS is a database containing adverse effect (typically mortality) reports on non

- target organisms where such effects have b een associated with the use of pesticides . Both IDS and EIIS are maintained by the Agency’s Office of Pesticide Programs

. Another data base with information on non

- target birds is the Avian Monitoring Information System (AIMS), which is maintained by the A merican Bird Conservancy. See Section 7.4 above for details about reported incidents involving chlorsulfuron.

Where available, sublethal effects observed in both registrant

- submitted and open literature studies will be evaluated qualitatively. Such effec ts have included behavioral changes ( e.g. , lethargy, changes in coloration and effects olfaction). Quantitative assessments of risks, though,

### 35 are limited to those endpoints that can be directly linked to the Agency’s assessment endpoints of impaired survi val, growth and reproduction.

The assessment of risk for direct effects to non

- target organisms employ s the assumption that toxicity of chlorsulfuron to birds is similar to that for terrestrial

- phase amphibians and reptiles

. An analogous assumption is made for fish and aquatic

- phase amphibians

.

The acute measures of effect use d for animals 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 5 0 

### 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 listed and non

- listed animals are the NOAEL/NOAEC and
NOEC. NOAEL stands for “No Observed

- Adv erse

- Effect

- 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

- Concentration”) is the highest test
concentration at which none of the observed effects were statistically different from the control.
The NOEC is the No

- Observed

- Effects

- Concentration. For non

- listed plants, only acute exposures are assessed ( i.e. , EC 25 

### for terrestrial plants and EC 50 

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

### is used.

**14.3. Integration of Exposure and Effects** 

Risk characterization is the integration of exposure and ecological effects characterization to determine potential ecologic al risk s from the use of chlorsulfuron as de scribed on labels

, and the
likelihood of direct and indirect effects to non

- target organisms in aquatic and terrestrial habitats. The exposure and toxicity effects data are integrated in order to evaluate the risks of adverse ecological effects on non

- tar get species. For the assessment of chlorsulfuron risks, the risk quotient (RQ) method is used to compare exposure and measured toxicity values. EECs are divided by acute and chronic toxicity endpoint s . The resulting RQs are then compared to the Agency’s LOCs ( USEPA, 2004 ) . These criteria ar e used to indicate when uses of chlorsulfuron

, as directed on the label, have the potential to cause adverse direct or indirect effects to non

- target organisms

. As noted previously, where data are lacking on the toxicity of chlorsulfuron or its transformation products , risk will be presumed.

14.3.A. Deterministic and Probabi listic Assessment Methods

Calculation of r isk quotients (and the determinations of areas of effect which are calculated using risk quotients) will primarily depend on the deterministic point

- estimate based approach. An effort may be made to further descr ibe risk using probabilistic tools that the Agency has developed. These tools have been reviewed by FIFRA Scientific Advisory Panels and have been deemed as appropriate means of refining assessments where deterministic approaches have
identified risks.

### 36 **14.4. Endangered Species Assessments** 

Consistent with the Agency’s responsibility under the Endangered Species Act (ESA), the Agency will evaluate risks to Federally

- listed threatened and/or endangered (listed) species from registered uses of chlorsulfuron . Thi s assessment will be conducted in accordance with the
Overview Document ( USEPA, 2004 ) , provisions of the ESA, and the Ser vices’ Endangered Species Consultation Handbook ( USFWS/NMFS, 1998 )

.

The action area is used to identify all listed (threatened and endangered) species and designated critical habitat that could be affected by the Federal action. The Federal action is the authorization or registration of pesticide use or uses as described on the label(s) of pesticide products containing a particular active ingredient. The action area is defined by the Endangered Species Act as, “all areas to be affected directly or indirectly by the 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 potential use of the pesticide.

In the case of nationwide ecological risk assessment conducted for chlorsulfuron under Registration Review, the actio n area will encompass the entire U nited S tates and its territories. The purpose of defining the action area as the entire U nited S tates and its territories is to ensure that the initial area of consideration encompasses all areas where chlorsulfuron may b e 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 indirect effects and any potential 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 nati onwide 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 critical habitat that may potentially be affected by the action. The Agency will use more rigorous analysis including consideration of available land cover data, toxicity data, and exposure information to determine areas where individual listed species and designated critical hab itat may be affected or modified via endpoints associated with reduced survival, growth, or reproduction.

**14.5. Human Health Drinking Water Assessment** 

In order to bring the drinking water assessment up to date with current data, models and simulation model guid ance, a new drinking water assessment will be conducted to support future
human hea lth dietary risk assessments of chlorsulfuron

. Concentrations of chlorsulfuron (and identified residues of concern) in surface waters will be estimated using PRZM and EXAMs (see
descr iption above). Percent Cropped Area (PCA) adjustment factors are used to account for the maximum fractional area within a watershed that may be planted with a modeled crop, and are used to modify human health estimated drinking water concentrati ons predicted by PRZM and
EXAMS ( Echeverria et al. , 2012 )

. Chlorsulfuron has uses in agricultural, commercial, and residential uses sites; therefore, a PCA of 1.0 will be used. Previous drinking water a ssessments used a PCA of 0.87 for turf uses ( Kiernan and Young, 2005, DP330621 )

.

### 37 A n Estimated Drinking Water Conc entration (EDWC) of chlorsulfuron in groundwater will be estimated using EFED’s Tier I aquatic model SCIGROW version 2.3; 8/8/2003

.

The drinking water assessme nt will also include available surface and ground water monitoring data with consideration of changes in use patterns that may have occurred. States are encouraged to submit monitoring data for review.

**14.6. Endocrine Disruptor Screening Program** 

As required by FIFRA and FFDCA, EPA reviews numerous studies to assess potential adverse outcomes from exposure to chemicals. Collectively, these studies include acute, subchronic and chronic toxicity, including assessments of carcinogenicity, neurotoxici ty, developmental, reproductive, and general or systemic toxicity. These studies include endpoints which may be susceptible to endocrine influence, including effects on endocrine target organ histopathology, organ weights, estrus cyclicity, sexual maturati on, fertility, pregnancy rates, reproductive loss, and sex ratios in offspring. For ecological hazard assessments, EPA evaluates acute tests and chronic studies that assess growth, developmental 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 section 408(p), chlorsulfuron is subject to the endocrine screening part of the Endocrine Disruptor Screening Program (EDSP).

EPA has developed the EDSP to determine whether certain substances (including pesticide active and other ingredients) may have an effect in humans or wildlife similar to an eff ect produced by a “naturally occurring estrogen, or other such endocrine effects as the Administrator may designate.” The EDSP employs a two

- tiered approach to making the statutorily required
determinations. Tier 1 consists of a battery of 11 screening a ssays to identify the potential of a chemical substance to interact with the estrogen, androgen, or thyroid (E, A, or T) hormonal systems. Chemicals that go through Tier 1 screening and are found to have the potential to interact with E, A, or T hormonal systems will proceed 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 any adverse endocrine

- related effects caused by the substance, and
establish a dose

- response relationship between the dose and the E, A, or T effect.

Under FFDCA section 408(p), the Agency must screen all pesticide chemicals. Between October 2009 and February 2010, EPA issued test orders/data call

- ins for the firs t group of 67 chemicals, which contains 58 pesticide active ingredients and 9 inert ingredients. Chlorsulfuron is not among the group of 58 pesticide active ingredients on the initial list to be screened under
the EDSP ( http://www.epa.gov/scipoly/oscpendo/pubs/final_list_frn_041509.pdf ) . Accordingly, as part of registration review, EPA will issue future EDSP orders/data call

- ins, requiring the submission of EDSP screening ass ays for chlorsulfuron

. For further information on the status of the EDSP, 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/

.

### 38 

## 15. **Preliminary Identification of Data Gaps**

**15.1. Fate** 

Several fate studies are needed to better characterize the environmental fate and transport of
chlorsulfuron. Given that the primary risk concern for chlorsulfuron is risk to plants; the main uncertainties these data requirements will help understand is the potential risk to plants. The studies listed below will decrease the uncertainty in determining the potentia l exposure to the pesticide.

• Aerobic Soil Metabolism (OPPTS 12

, 13 

### Guideline number 835.4100) for parent

• Aerobic Aquatic Metabolism (OPPTS Guideline Number 835.4300) for parent

• Anaerobic Aquatic Metabolism (OPPTS Guideline Number 835.4400) for parent

• Aquati c Field Dissipation Study (OPPTS Guideline Number 835.6200) for parent

• Environmental Chemistry Methods for Soil and Plant Material ( OCSPP Guideline
850. 6 100) for parent and major degradates

• Environmental Chemistry Methods for Water ( OCSPP Guideline 850. 6 1 00) for parent and major degradates to support the aquatic field dissipation study

Table 10 summarizes the fate data requirements for chlorsulfuron . A rationale discussing the need for each study is also provided below.

Table 10 . Summary of Submitted Envir onmental Fate Studies, Study Classifications and Data Gaps for Chlorsulfuron and Its Degradates

OPPTS or

OCSPP
Guideline MRID (Test
Substance 1 ) Study
Classification Comments on Study
Classification Data Gap? 3 Comments

Hydrolysis
835.2120 (161

- 1) 35270 Not formally
classified Guideline study
recommended in
Garner ( 1980 )

.

No

-- 83946 Invalid Raw data not provided. Radiochemical purity

not provided. Percentages of degradates not

provided.
42156701

same as 41408102 Acceptable

Aqueous Photolysis
835.2240 (161

- 2) 42156702
Same as
41408101 Acceptable No

--

12 Office of Prevention, Pesticides, and Toxic Substances ( OPPTS ) is now the Office of Chemical Safety and Pollution Prevention (OCSPP); however, some guidelines still reference OPPTS and so those guidelines are
referenced w ith OPPTS in this document.

13 A list of all OPPTS and OCSPP Guidelines discussed in this document is available in Appendix G

.

.

### 39 OPPTS or

OCSPP
Guideline MRID (Test
Substance 1 ) Study
Classification Comments on Study
Classification Data Gap? 3 Comments

Soil Photolysis
835.2410 (161

- 3) 83947 same as
86813 Invalid

--

No

-- 41721001

same as 42156703 Acceptable

--

Aerobic Soil
Metabolism
835.4100 (162

- 1) 42214201 Most studies unacceptable,

one study supplemental Not enough
information is
available in the studies

to use the results to

fulfill guideline

requirements

Yes Metabolism data are needed to estimate exposure to residues

in the aquatic environment
and to define the transformation products likely
to occur in aerobic soil. 00035273 Supplemental Maintained in a greenhouse and temperature was not held constant.
00035275 same

as 00086814 and

00083950 Supplemental One ring labeled. One replicate. No raw data. Degradates not
followed.

Anaerobic Soil
Metabolism
835.4200 (162

- 2) No data
submitted Not applicable

-- No While anaerobic soil
metabolism data are required according the 40 CFR 158.1300, these data are not used in exposure modeling and exposure of chlorsulfuron to humans in ground water is currently not a major concern.

Therefore, these data would likely have little impact on the
risk conclusions. Aerobic Aquatic
Metabolism
835.4300 (162

- 4) No data
submitted Not applicable

-- Yes Metabolism data are needed to estimate exposure to residues

in the aquatic environment
and to define the transformation products likely to occur in the aquatic
environment. Anaerobic Aquatic
Metabolism
835.4400 (162

- 3) 42156701

same as 00086815 Supplemental Alfalfa added to test system. Degradation
was faster in sterile controls suggesting that degradation was

not mediated by
microbes. Yes

Batch Equilibrium
835.1230 (163

- 1) 42156705 Supplemental Adequate data for parent on 4 soils

No Batch equilibrium data are available on 4 soils only.

Typically data are also
available on a sediment as well. Data were not requested

as they are not expected to substantially impact the risk
conclusions. 00083948 Invalid
45371826 Invalid

46155803
Triazine amine Under review

### 40 OPPTS or

OCSPP
Guideline MRID (Test
Substance 1 ) Study
Classification Comments on Study
Classification Data Gap? 3 Comments

Aquatic Field Dissipation
835.6200 No data
available NA

-- Yes As chlorsulfuron may be used
in areas that will become flooded after use, an aquatic

field dissipation study is

recommended that is representative of these use patterns.

Terrestrial Field Dissipation No data
available NA

-- No Lysimeter studies are
available and additional data

are not expected to impact
risk conclusions.

Bioconcentration
Factor
850.1730 42214204
00083951
00086820 Supplemental MRID 42214204 is a compilation of
00083951 and

00086820. No K OW range from 0.04 to 2.16 and chlorsulfuron is not likely
to bioconcentrate.

Environmental Chemistry
Method: Water
850.6100 43406701 supplemented by 43406702 Not reviewed Solid phase extraction with C18 cartridge

and HPLC

- UV: chlorsulfuron,
metsulfuron methyl,

and several other compounds. No

independent laboratory validation.
Limit of detection was 0.05 μg/L. 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 All major degradat es should be included

in the method and have an associated LOQ and limit of detection (LOD) lower than
levels that would result in a
risk concern.

Environmental Chemistry
Method: Soil
and sediment
850.6100 No data
available NA

-- 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 terrestrial field

dissipation study and to provide the ability to monitor
for chlorsulfuron in the case.

Enviro nmental Chemistry
Method: Plant
Material
850.6100 No data
available NA

-- 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 terrestrial field

dissipation study and to
monitor for chlorsulfuron.
Abbreviations: ECM=Environmental Chemistr y Method; ILV=independent laboratory Validation
1 Test substance is included if the study was conducted on a material other than the parent, chlorsulfuron.
2 The LOQ was based on the NOAEC for aquatic vascular plants (NOAEC = 0.00024 mg a.i./L) and an LOC of 1 (MRID 45832901).
3 The study is considered a data gap if it is required in 40 CFR 158.1300 or data are needed to reduce uncertainty
in the risk assessment.

### 41 15.1.A. Rationales for Requesting Fate Studies

• Aerobic Soil Metabolism (OPPTS Guideline number 835.4100) for parent ; Aerobic Aquatic Metabolism (OPPTS Guideline Number 835.4300) for parent ; Anaerobic Aquatic Metabolism (OPPTS Guideline Number 835.4400) for parent ;



### These three data requirements are standard data requirements for terrestrial and aquatic use patterns and available data are not adequate for risk assessment (40 CFR Part 158.1300). Data are needed to 1) identify potential degradates and transformation products, 2) better understand the potential for metabolism and degradation in the environmen t, and 3) to determine how the environmental fate of chlorsulfuron in the field compares to that predicted by laboratory studies. In the absence of laboratory studies examining degradation kinetics, degradation of chlorsulfuron
in various media will eithe r be assumed to be stable or a conservative estimate of degradation will be estimated based on open literature data.

• Aquatic Field Dissipation Study (OPPTS Guideline Number 835.6200) for representative
end

- use products and uses;
Environmental Chemist ry Methods for Water (OCSPP Guideline 850.6100) for parent and major degradates to support the aquatic field dissipation study

Chlorsulfuron may be applied to intermittently dry areas including wetlands, marshes, and bogs. It is possible that chlorsulfur on will be introduced into the aquatic environment when water rises after areas are treated with chlorsulfuron. This is similar to an aquatic use. Aquatic field dissipation studies are standard data requirements for applications to water bodies and the u se pattern is similar to uses on rice where a pesticide is applied to a dry field and the field is then flooded. The aquatic field dissipation study is requested in order to better understand the potential for aquatic exposure and exposure to degradates f rom uses in intermittently dry areas. This study is most important in informing the exposure assessment for aquatic plants from these use patterns. Aquatic field dissipation studies require the submission of an environmental chemistry method and correspo nding independent laboratory validation (ILV) specific to the parent and major transformation products observed in environmental laboratory studies. It is recommended that a protocol be submitted prior to initiation of the study.

• Environmental Chemistry Methods for Water (OCSPP Guideline 850.6100) for parent and major transformation products; Environmental Chemistry Methods for Soil (OCSPP Guideline 850.6100) for parent and major transformation products; Environmental Chemistry Methods for Plants (OCSPP G uideline 850.6100) for parent and major transformation products

Environmental Chemistry Methods ( ECM ) and ILV in water, soil, and plants are needed with a limit of quantitation (LOQ) that are relevant to the potential for risk for plants. 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). For water, the LOQ should be below 0.2 μg/L

. Methods and associated ILV are also needed to support field di ssipation studies and
the method evaluated must be the same method used in the corresponding field dissipation study.

### 42 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). Currently available methods do not have an ILV or low enough LOQ and LOD.

15.1.B Rationales for Not Requesting Fate Studies

• Anaerobic Soil Metabolism (OPPTS Guideline Number 835.4200) for parent

While an aerobic soil metabolism data are required according the 40 CFR 158.1300, these data are not used in exposure modeling and exposure of chlorsulfuron to humans in ground water is currently not a major concern. Therefore, these data would likely have little impact on the risk
conclusions. Therefore, this study is not requested at this time.

• Batch Equilibrium (OPPTS Guideline Number 835.1230) for parent in one sediment

Sorption coefficients were measured on four soils. Data are normally measured on four soils and

one s ediment. Sediment sorption coefficients are often higher than those measured in soil;
Allen

- king et al. ( Allen

- King et al. , 2002 ) state that, “compared to soil organic matter, freshwater sediment organic matter has been reported to contain fewer polar functional groups, and has been observed to have roughly 2

- fold greater HOC [hydrophobic organic sorption]. Based on
chlorsulfuron’s water solubilities and pK
a 

### value, its affinity to organic materials (and thus organic carbon partition coefficient, K OC 

### ) is expected to decrease with increasing pH . Submitted batch equilibrium data do not confirm this; however, open literature support th e conclusion that pH is one of the most important factors in the resulting sorption coefficients and is more important than the percent organic carbon ( Cotterill et al. , 1989 ) . Additional data on sorption in sediment is not expected to alter the risk conclusions because of the following:

1) pH is one of the main factors influencing sorption of chlorsulfuron. Sorption coefficients for soil are available over a range of pH (5.4 to 8). 2) Sorpiton coefficients in soil indicate that chlorsulfuron has a high mobility

• Batch Equilibrium (OPPTS Guideline Number 835.1230) for ring

- opened chlorsulfuron
and 2

- chlorophenylsulfonylurea

Th e ecological risk assessments identified ring

- opened chlorsulfuron and 2

- chlorophenylsulfonylurea as residues of concern for chlorsulfuron. Both of these residues were major residues observed in laboratory and field studies. Therefore, data on the sorpti on coefficients of these degradates are needed to permit estimat ion of concentrations of total toxic
residues in water. O

- desmethyl chlorsulfuron is expected to have mobility similar to that of the parent; therefore, data on the parent compound may be use d to estimate soil sorption of this degradate

. EPIWEB version 1.4 predicted K OC 

### values of 124, 423, and 1 L/kg

- organic carbon for chlorsulfuron, ring opened chlorsulfuron, and 2

- chlorophenylsulfonylurea, respectively. These differences in sorption coeff icients had little impact on the estimated EEC using PRZM/EXAMs. In the absence of additional data, sorption coefficients will be estimated using
the current version of EPIWEB ( USEPA, 2009b )

. Batch equilibrium studies for degradates are

### 43 available in the open literature ( AERU, 2012 ) . Submission of these open literature data to the agency would reduce uncertainty in the final risk assessment.

• Terrestrial Field Dissipation (OPPTS Guideline Number 835.6100) for parent

While a terrestrial field dissipation study is required according to 40 CFR Part 158.1300, these data are not used in exposure modeling and lysimeter studies are available that provide information on the leaching behavior and degradates observed in the field. Therefore, these data would likely have little impact on the risk conclusions. Therefore, this study is not requested at
this time.

15.1.A. Additional Information that would be Useful fo r Monitoring and Risk

Assessment

Having access to sensitive methods (and standards) using a variety of instruments would enable State Agencies and other interested third parties to investigate incidents or other impacts
associated with chlorsulfuron use a nd could provide Agency with a better set of field data than we have at the present to assess the risk to plants as a results of typical use. These methods could be specific to chlorsulfuron and/or its transformation products, or multiresidue methods for multiple compounds that include chlorsulfuron and/or its degradates. These methods would add to the methods already available for monitoring.

**15.2. Effects** 

The ecological effects database for chlorsulfuron parent is complete and adequate for risk

assessme nt. Additional ecological effects studies on chlorsulfuron are not needed at this time to assess the potential risk of chlorsulfuron exposure to non

- target organisms. However, i f application rates change or new uses are proposed in the future, then these data may be required.

Effects studies need ed for the degradate s or chlorsulfuron are discussed in Section B.3.

The following study is a standard data requirement for chlorsulfuron ; however, data are not requested at this time.

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

Table 11 summarizes the effects data requirements for chlorsulfuron

.

### 44 Table 11 . Summary of Submitted Ecological Effects Studies and Data Gaps for Parent
Chlorsulfuron

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

Terrestrial Animals

850.2100
Avian Oral Toxicity

– Waterfowl or Upland Game Bird 000352

- 63 Acceptable No

850.2100 Avian Acute Toxicity

- Passerine NA NA No See discussion below regarding acute toxicity for passerines.

850.2200 Avian Dietary Toxicity 000352

- 66 Acceptable No

850.2300 Avian Reproduction 426340

- 01 Acceptable Acceptable No

850. 3020 Honeybee Acute Contact Toxicity 421299

- 02 Acceptable No

Aquatic Animals

850.1075
Freshwater Fish

- Acute Toxicity 000352

- 58 Acceptable No

850.1075
Saltwater Fish

- Acute Toxicity 419764

- 01 Acceptable No

850.1010
Freshwater
Invertebrates

- Acute Toxicity 000352

- 62 Acceptable No

850.1025
850.1035
Saltwater
Invertebrates

- Acute Toxicity 419764

- 02 Acceptable No

850.1300
Freshwater
Invertebrates

- Life Cycle Test 419764

- 04 Supplemental No The submitted study has a number of deficiencies
and deviations from the guideline

. However, the results of the study are adequate for risk

assessment.

850.1350
Saltwater
Invertebrates

- Life Cycle Test No data No

850.1400
Freshwater Fish

- Early Life Stage Test 419764

- 05 Acceptable No

850.1500
Fish

- Life Cycle Test N R No

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

Plants

850.4100
Terrestrial Plant Toxicity

- Tier 1 Seedling Emergence 463618

- 01 Supplemental No The submitted study does not meet the guideline requirements for a seedling emergence study due to plant crowding and reduced light conditions. However, a new tier 1 seedling e mergence study is not requested as tier 2 data are available.

850.4225
Terrestrial Plant Toxicity

- Tier 2 Seedling Emergence 463618

- 01 Supplemental No The submitted study is classified as supplemental
but data are useful for risk assessment.

850.4150
Terrestrial Plant Toxicity

- Tier 1 Vegetative Vigor 463268

- 01 Supplemental No The submitted study does not meet the guideline requirements for a vegetative vigor study because the application rates tested were lower than the maximum application rate, and was not tested on all 10 species. However, a new tier 1 vegetative vigor study is not requested as tier 2 data are
available.

850.4150 Terrestrial Plant Toxicity

- Tier 2 Vegetative Vigor 463268

- 01 Supplemental No The submitted study is classified as supplemental
but data are useful for risk assessment.

(Non

- Guideline) Special Study

- Non

Target Plant Reproductive Toxicity 487769

- 02,

487769

- 03 Acceptable No

850.4400 Aquatic Plant Growth

Algae 458329

- 02 Acceptable No

850.4400 Aquatic Plant Growth

Vascular Plants 458329

- 01 Supplemental No The submitted study was classified as supplemental because it was conducted as a static

test and test concentrations were not measured at
test termination. However, the study results are
useful for risk assessment.



### Rationales for Not Requesting Acute Oral Toxicity Test with a Passerine Species (850.2100)

According to the 40 CFR Part 158 .630 , acute oral toxicity data are required for a passerine species. Because no acute oral toxicity data have been submitted for a passerine species exposed

to chlorsulfuron , this is a data gap. No acute oral toxicity data with passerines for chlorsulfuron

or its degradates have been identified in the scientific literature (using ECOTOX).

Available acute oral toxicity data for birds (MRID 000352

- 63 ) indicate that chlorsulfuron is practically nontoxic to birds on an acute oral exposure basis. In addition, in a sub

- acute dietary toxicity study (MRID 000352

- 66 ) with the mallard duck, no mortalities were observed at the highest test levels ( i.e., 5,000 mg a.i./kg

- diet ) and the compound is classified as practically non

toxic to birds on a subacute dietary exposure basis

. In addition, no sublethal effects were
observed in these studies.

### 46 Given the low application rate of chlorsulfuron ( i.e., 0. 12 lb a.i./A for ornamental turf) , it is expected that the exposure of birds to chlorsulfuron will be low ( the dose

- based EEC for birds is
33.31 mg/kg/day based on T

- REX version 4.1.1). The lowest acute values for birds are 5,000 mg a.i./kg

- bw (highest dose tested) for acute oral toxicity for mallard ducks ; the corresponding
NOAEL value is 5,000 mg a.i./kg

- bw (no mortal ity or frank toxicity was observed). As the acute oral toxicity value is based on body weight, the NOAEL value for the avian acute oral was
entered into T

- REX to o btain the adjusted toxicity value for the much smaller passerine bird. The adjusted acute toxicity value for 20

- g birds is 2596 mg a.i./kg

- bw. This estimated acute toxicity value for birds is at least 79 times the EEC. 14 

### Given the data for a cute toxicity of
chlorsulfuron to aquatic and terrestrial vertebrates and the absence of incident data to the contrary , the weight

- of

- evidence suggests that chlorsulfuron will be relatively nontoxic to passerine species as well. Therefore, EFED is not requesting oral toxicity data for passerines exposed to chlorsulfuron or its degradates.

15.2.A. Degradate Toxicity Data

Structure

- activity relationship data, read across analysis, and exposure estimates were used to
make the determinations on which degradates would be evaluated in the risk assessment. While data on chlorsulfuron degradates are not required, o pen literature ecotoxici ty data are available
and could be used to confirm the determination ( Appendix I ). These studies include the following for o

- desmethyl chlorsulfuron, ring

- opened chlorsulfuron, chlorosulfonamide, triazine amine, and triazine urea.

• Freshwater fish

- acute toxicity (OPPTS Guideline 850.1075)

• Freshwater invertebrate

- acute toxicity (OPPTS Guideline 850.1010)

• 96

- hr algal study (OPPTS Guideline 850.4400)

• Fr eshwater Invertebrates

– Life Cycle Test (OPPTS Guideline 850.1300)

Open literature data measuring sorption coefficients for some degradation products are also available. Batch equilibrium data on degradates that retain the sulfonylurea bridge would redu ce uncertainty in the estimated exposure to total residues of concern for ecological risk assessment.



## 16. **Other Information Needs**

There is specific information that will assist the Agency in refining the ecological risk assessment, including any species

- speci fic effects determinations. The Agency is very interested in obtaining the following information:
1. confirmation on the following label information

a. frequency of application, application intervals, formulation types, and maximum number of applications per se ason b. geographic limitations on use

c. spray drift advisory statements
2. use or potential use distribution ( e.g ., acreage and geographical distribution of relevant crops)

14 For the lowest ratio for acute terrestrial animals (acute avian oral): 2596 ÷ 33 = 79

### 47 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 intervals) by crop

– national, state, and county
6. sub

- county crop location data
7. directly acquired cou nty

- level usage data (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 used 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

mam malian mortalities) not already reported to the Agency
10. monitoring data

In order to assess the risk to terrestrial organisms exposed to granules the weight of one granule for each granule formulation would be useful.



## 17. **References**

Abbots, J. 1995a. Results of the HED Metabolism Committee Meeting Held on 7/18/95: Chlorsulfuron Residue to be Regulated in Animal Commodities . TXR 0059014. Memorandum From J. Abbots to H. E. D. M. Committee. August 2, 1995. Health Effe cts Division. Office of Pesticide Programs. United States Environmental Protection Agency. Abbots, J. 1995b. Results of the HED Metabolism Committee Meeting Held on 4/4/95: Chlorsulfuron Residue to be Regulated. TXR 0050913. Memorandum From to H. E. D. M. Committee. April 11, 1995. Health Effects Division. Office of Pesticide Programs. United States Environmental Protection Agency. AERU. 2012. The FOOTPRINT Pesticide Properties Database. Agriculture & Environment Research Unit (AERU). Availabl e at http://sitem.herts.ac.uk/aeru/footprint/ (Accessed August 8, 2012).
Allen

- King, R. M., Grathwohl, P., & Ball, W. P. 2002. New modeling paradigms for the sorption of hydrophobic organic chemicals to heterogenous carbonaceous matter in soils, sediments, and rocks. Advances in Water Resources, 25 , 985

- 1016. Armitage, J. M., & Gobas, F. A. P. C. 2007. A terrestrial food

- chain bioaccumulation model for
POPs. Environmental Science and Technology, 41 , 4 019

- 4025. Cotterill, E. G., Walker, A., & Welch, S. J. 1989. Adsorption and degradation of chlorsulfuron
and metsulfuron

- methyl in soils from different depths. Weed Research, 29 , 281

- 287. Echeverria, M., Jones, R. D., Peck, C., Ruhman, M., Shelby, A., Tha wley, S., et al. 2012. Development and Use of Percent Cropped Area and Percent Turf Area Adjustment Factors in Drinking Water Exposure Assessments: 2012 Update . March 16, 2012. Environmental Fate and Effects Division. Office of Pesticide Programs. Unite d States

### 48 Environmental Protection Agency. Available at http://www.epa.gov/oppefed1/models/water/pca_adjustment_dwa.html (Accessed April 25, 2012). European Commission. 2007. Draft Assessment Report. Initial Risk Assessment Provided by the Rapporteur Member States Greece for the Existing Active Substance Chlorsulfuron.
Volume 1 . November 2007. European Commission. Available at http://dar.efsa.europa.eu/dar

- web/provision (Accessed August 8, 2012). Fletcher, J. S., Nellessen, J. E., & Pfleeger, T. G. 1994. Literature

- Review and Evaluation of the Epa Food

- Chain (Kenaga) Nomogram, an Instrument for Estimating Pesticide

- Res idues
on Plants. Environmental Toxicology and Chemistry, 13 (9), 1383

- 1391. Fletcher, J. S., Pfleeger, T. G., & Ratsch, H. C. 1993. Potential environmental risks associated with the new sulfonylurea herbicides. Environmental Science and Technology, 27 (10),
2250

- 2252. Garner, W. 1980. Environmental Fate Review of 352

- EUP

- RNL

- 105 for DPX

- 4189 . November 17, 1980. Environmental Fate Branch. Office of Pesticide Programs. United States Environmental Protection Agency. Gobas, F. A. P. C., Kelly, B. C., & Arnot, J. A. 2003. Quantitative structure activity relationships for predicting the bioaccumulation of POPs in terrestrial food

- webs. QSAR Comb. Sci, 22 , 329

- 336. Gregg, B. C. 2008. Product Chemistry Review of Technical Product . January 10, 2008.
Memorandum Fro m B. C. Gregg to B. Adler. Product Chemistry Team. Office of Pesticide Programs. United States Environmental Protection Agency. Hoerger, F., & Kenaga, E. E. 1972. Pesticide Residues on Plants: Correlation of Representative
Data as a Basis for Estimat ion of their Magnitude 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. Kiernan, B. D., & Young, D. F. 2005.DP330621. Environmental Fate and Ecological Risk Assessment for the Re

- registration of Chlorsulfuron . DP330621. May 10, 2005. Environmental Fate and Effects Division. Office of Pesticide Programs. United States Environmental Protection Agency.
NAFTA. 2012. Guidance for Evalua ting and Calculating Degradation Kinetics in
Environmental Media . December 2012. NAFTA Technical Working Group on
Pesticides. Available at http://www.epa.gov/opp fead1/international/naftatwg/guidance/degradation

- kin.pdf (Accessed June 12, 2012). Ratnayake, S., Doucoure, C., & Smearman, S. 2012. BEAD Chemical Profile for Registration Review: Chlorsulfuron (118601) . Memorandum From to E. Meiderhoff. Biological and
E conomic Analysis Division. Office of Pesticide Programs. United States Environmental Protection Agency. Shanaman, L. 2002.D266073. Drinking Water Assessment to Support TRED for Chlorsulfuron

. D266073. Memorandum From L. Shanaman to J. Tompkins. June 25, 2002. Environmental Fate and Effects Division. Office of Pesticide Programs. United States Environmental Protection Agency. Spray Drift Task Force Spray Software. AgDRIFT (Version 2.01). Available at http://www.agdrift.com/AgDRIFt2/DownloadAgDrift2_0.htm Teske, M. E., & Curbishley, T. B. 2003. Continuum Dynamics, Inc. AGDISP Version 8.07 User

### 49 Manual . Prepared For United States Department of Agriculture Forest Service. C.D.I.
T echnical Note No. 02

- 06. June 2003. Ullagadi, A., Koper, C., & Pease, A. 2010. Ecological Risk Assessment for the Section 3 New Chemical Registration of Aminocyclopyrachlor on Non

- crop Areas and Turft . D358167. January 22, 2010. Environmental Fate and Ef fects Division. Office of Pesticide Programs. United States Environmental Protection Agency.
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://www.epa.gov/raf/publications/guidelines

ecological

- risk

- assessment.htm (Accessed November 7, 2012).
USEPA. 2004. Government Printing Office. Overview of the Ecological Risk Assessment Process in the Office of Pesticide Programs . United States Environmental Protection 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. 2005. R.E.D. FACTS: Chlorsulfuron . EPA

- 738

- F

- 05

- 002. May 30, 2005. Office of Prevention, P esticides, and Toxic Substances. United States Environmental Protection Agency. Available at http://www.epa.gov/oppsrrd1/REDs/factsheets/chlorsulfuron_factsheet.pdf (Acc essed September 6, 2012).
USEPA. 2006. User's Guide: TerrPlant version 1.2.2. Memorandum From to Environmental Fate and Effects Division, Office of Pesticide Programs, Office of Chemical Safety and Pollution Prevention, United States Environmental Protec tion Agency. Available at http://www.epa.gov/oppefed1/models/terrestrial/terrplant/terrplant_user_guide.html (Accessed May 13, 2011).
USEPA. 2008. User's Gui de: T

- REX version 1.2.2. Memorandum From to Environmental Fate and Effects Division, Office of Pesticide Progams, Office of Chemical Safety and Pollution Prevention, United States Environmental Protection Agency. Available at http://www.epa.gov/oppefed1/models/terrestrial/trex/t_rex_user_guide.htm (Accessed May 13, 2011).
USEPA. 2009a. ECOTOXicology Database

, United States Environmental Protection Agency (USEPA) . Avai lable at http://cfpub.epa.gov/ecotox/ (Accessed June 19, 2009). USEPA. 2009b. Estimation Program Interface (EPI) Suite: United States Environmental Protection Agency. Available at http://www.epa.gov/oppt/exposure/pubs/episuite.htm (Accessed August 24, 2012).
USEPA. 2009c. SAP Minutes No. 2009

- 01. A set of Scientific Issues Being Considered by the Environmental Protection Agency Regarding: Selected I ssues 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 Coordination and Policy. Available at http://www.epa.gov/scipoly/sap/meetings/2008/102808_mtg.htm (Accessed July 9, 2009).
USEPA. 2010. Guidance for Reporting on the Environmental Fate and Transport of the Stressors of Concern in the Problem Formulation for Registration Review, Registration Review Risk Assessments, Listed Species Litigation Assessments, New Chemical Risk Assessments, and Other Relevant Risk Assessments . January 25, 2010. Environmental

### 50 Fate and Effects D ivision, . Available at http://www.epa.gov/pesticides/science/efed/policy_guidance/team_authors/endange red_s pecies_reregistration_workgroup/esa_reporting_fate.htm (Accessed July 5, 2012).
USEPA. 2011. U.S EPA Water Models . Memorandum From to Environmental Fate and Effects Division, Office of Pesticide Programs, Office of Chemical Safety and Pollution
Preve ntion, United States Environmental Protection Agency. Available at http://www.epa.gov/oppefed1/models/water/#przm (Accessed May 13, 2011).
USEPA. 2012a. Criteria Used by the PBT Profiler . September 4, 2012. Office of Chemical Safety and Pollution Prevention. United States Environmental Protection Agency.
Available at http://www.pbtprofiler.net/criteria.asp (Accessed September 7, 2012)

. USEPA. 2012b. Ecological Incident Information System. Environmental Fate and Effects Division. United States Environmental Protection Agency. USEPA. 2012c. Office of Pesticide Programs Chemical Search. Office of Pesticide Programs.
United States Envi ronmental Protection Agency. Available at http://iaspub.epa.gov/apex/pesticides/f?p=chemicalsearch:1 (Accessed July 5, 2012).
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Information Resources. Available at http://ipmworld.umn.edu/chapters/whitacreherb.htm (Accessed August 24 , 2012). Wood, A. 2009. Compendium of Pesticide Common Names. Available at http://www.alanwood.net/pesticides/index.html (Accessed June 19, 2009).

Data Submitted To Support Registration

**17.1. Studies Related to**  **Environmental Fate Data**

MRID Citation Reference

Reports of Multiple phys/chem Characteristics
31432 E.I. du Pont de Nemours & Company (1977) DPX

- 4189: Technical Data Sheet. (Unpublished study received Jun 16, 1980 under 352

- EX

- 105; CDL:099459

- E)
35255 E.I. du Pont de Nemours & Company (1980) ?Chemical Study of DPX

- 4189|. (Unpublished study received Jun 16, 1980 under 352

- 105; CDL:099462

- A)
35271 Rapisarda, C.; Shrivastava, S.P.; Butler, L.D. (1978?) Physical Properties of DPX

- 4189: Octanol/Water Partition Ratio, Solubili

- ties, and Soil Absorption Data. (Unpublished study received Jun 16, 1980 under 352

- 105; submitted by E.I. du Pont de Nemours & Co., Wilmington, Del.; CDL:099462

- R)
83941 E.I. du Pont de Nemours & Company (1981) Du Pont Glean^(TM)I Weed Killer: Technical Data Sheet. (Unpublished study received Sep 1, 1981 under 352

- 403; CDL:245878

- A)
83948 Rapisarda, C.; Shrivastava, S.P.; Butler, L.D. (1980?) Physical Properties of DPX

- 4189: Octanol/Water Partition Ratio, Solubilities, and Soil Adsorption Data [K

- values and TLC (Rf)

### 51 Values]: Document No. AMR

- 28

- 81. (Unpublished study received Sep 1, 1981 under 352

- 403; submitted by E.I. du Pont de Nemours & Co., Wilmington, Del.; CDL:245878

- I)

99125 E.I. du Pont de Nemour s & Company, Incorporated (1981) Du Pont Glean^(TM)I Weed Killer: Technical Data Sheet. (Unpublished study received Nov 13, 1981 under 352

- 404; CDL:070470

- A)
148288 E. I. du Pont de Nemours & Co. (1985) [Product Chemistry Data for Finesse Herbicide]. Unpu blished compilation. 9 p.
40622707 Armstrong, J. (1988) Physical/Chemical Characteristics of End Use Product Du Pont Avatar Herbicide: Laboratory Project ID: FPC

- 88

- 5

- PC. Unpublished study prepared by E. I. du Pont de Nemours and Co., Inc. 9 p.
42454102 Schmuckler, M.; Moore, L. (1992) Physical and Chemical Characteristics of Chlorsulfuron: Lab Project Number: AMR 2370

- 92. Unpublished study prepared by E. I. du Pont de Nemours and Co. 25 p.
42454103 Moore, L. (1992) Solubility of Chlorsulfuron in Organi c Solvents Using Continuous Sample Agitation: Lab Project Number: AMR 2375

- 92. Unpublished study prepared by E.I. du Pont de Nemours and Co. 16 p.
42454104 Schmuckler, M. (1992) Determination of the Water Solubility of Chlorsulfuron, W4189 (Revision): Lab Project Number: W4189.B. Unpublished study prepared by E.I. du Pont de Nemours and Co. 27 p.
42454105 Schmuckler, M. (1992) Vapor Pressure of Chlorsulfuron at 25 degrees celsius (Revised): Lab Project Number: G/PC

- 22

- CA. Unpublished study prepared by E.I . du Pont de Nemours and Co. 15 p.
43898601 Schmuckler, M. (1992) Vapor Pressure of Chlorsulfuron at 25 (degrees) C: Lab Project Number:
G/PC

- 22

- CA. Unpublished study prepared by Du Pont Agricultural Products. 15 p.
42454106 Schmuckler, M.; Moore, L.; Wilds, J. (1992) Dissociation Constant of Chlorsulfuron: Lab Project Number: AMR 2367

- 92. Unpublished study prepared by E. I. du Pont de Nemours and Co. 22 p.
42454107 Schmuckler, M. (1992) N

- Octanol/Water Partition Coefficient of Chlorsulfuron (Revised): Lab Project Number: DUP

- 31

- 88: AMR

- 1224

- 88. Unpublished study prepared by Enviro

- Bio

- Tech, Ltd. and E.I. Du Pont de Nemours. 27 p.
47179901 Huntley, K. (2001) Chlorsulfuron Technical (DPX

- W4189): Determination of the UV/Visible Absorption. Project Number: 46649, 6283. Unpublished study prepared by Analytical Bio

Chemistry Labs., Inc. 29 p.
47831303

Miller, R. (2009) Chlorsulfuron Technical: Product Properties: Color, Physical State, Odor, Stability to Normal and Elevated Temperatures, Oxidation/Red uction: Chemical Incompatibility, pH, UV/Visible Absorption, Melting Point/Melting Range, Density/Relative Density/Bulk Density, Dissociation Constants in Water, Partition Coefficient (n

- Octanol/Water), Water Solubility, and Vapor Pressure. Project Number: CHB/EX/640/010/P/1, CHB/OP/MTH/183/P/2, CHB/EX/640/001/P/1. Unpublished study prepared by PhibroWood, LLC. 49 p.
42454108 Moore, L. (1992) Stability of Chlosulfuron in the Presence of Metal and Metal Ions, in Sunlight
and at Normal and Elevated Temperatures: Lab Project Number: AMR 2372

- 92. Unpublished study prepared by E. I. Du Pont de Nemours and Co. 24 p.
Hydrolysis
35270 Han, J.C.Y. (1960?) Hydrolysis and Photolysis Studies with 14C

- DPX

- 4189: AMR

- 08

- 80A. (Unpublished study received Jun 16, 1980 under 352

- 105; submitted by E.I. du Pont de Nemours & Co., Wil

- mington, Del.; CDL:099462

- Q)

### 52 83946 Han, J.C.Y. (19??) Hydrolysis of ^14IC

- Labeled DPX

- W4189: Document No. AMR

- 39

- 81. (Unpublished study received Sep 1, 1981 under 352

- 403; submitted by E.I. du Pont de Nemours & Co., Wilmington, Del.; CDL:245878

- G)
41408102 Dietrich, R.; McAleer, N. (1989) Hydrolysis of ?Phenyl(U)

- carbon 14|Chlorsulfuron and
?Triazine

- 2

- carbon 14|Chlorsulfuron: Lab Report No. AMR

- 1455

- 89.161

- 1. Unpublished study

prepa red by E.I. du Pont de Nemours & Co., Inc., Agricultural Products Dept. 61 p.
42156701 Dietrich, R.; McAleer, N. (1989) Hydrolysis of ?Phenyl(U)

- ?carbon 14||Chlorsulfuron and
?Triazine

- 2

- ?carbon 14||Chlorsulfuron: Lab Project Number: AMR

- 1455

- 89.161

- 1. Un

published study prepared by E.I. du Pont de Nemours & Co., Inc. 61 p.
Photodegradation

- water 41408101 Dietrich, R.; McAleer, N. (1989) Photodegradation of ?Phenyl(U)

- carbon 14|Chlorsulfuron and
?Triazine

- 2

- carbon 14|Chlorsulfuron in Water Conducted in Sunlight: Lab Report No. AMR

1455

- 89. Unpublished study prepared by E.I. du Pont de Nemours & Co., Inc., Agricultural Products Dept. 45 p.
42156702 Dietrich, R.; McAleer, N. (1989) Photodegradation of ?Phenyl(U)

- ?carbon 14||Chlorsulfuron and
?Triazine

- 2

- ?carbon 14||Chlorsulfuron in Water Conducted in Sunlight: Lab Project Number:
AMR

- 1455

- 89. Unpublished study prepared by E.I. du Pont de Nemours & Co., Inc. 44 p.
Photodegradation

- soil
83947 Han, J.C.Y. (1960?) Photolysis of ^14I

- C

- Phenyl Labeled DPX

- W4189 on Soil: Document No.
AMR

- 42

- 81. (Unpublished study received Sep 1, 1981 under 352

- 403; submitted by E.I. du Pont de Nemours & Co., Wilmington, Del.; CDL:245878

- H)
86813 Han, J.C.Y. (19??) Photolysis of ^14IC

- Phenyl Labeled DPX

- W4189 on Soil: Do cument No.
AMR

- 42

- 81. (Unpublished study received Nov 13, 1981 under 352

- 404; submitted by E.I. du Pont de Nemours & Co., Inc., Wilmington, Del.; CDL:070470

- H)
41721001 Hawkins, D.; Kirkpatrick, D.; Dean, G. (1990) The Photodegradation of ?Carbon 14| Chlorsulfuron on a Silty Clay Loam Soil: Lab Pro

- ject Number: HRC/DPT 205/90571: AMR

1563

- 89. Unpublished study prepared by Huntingdon Research Centre Ltd. 58 p.
42156703 Hawkins, D.; Kirkpatrick, D.; Dean, G.; et al. (1990) The Photodegradation of ?carb on 14|Chlorsulfuron on a Silty Clay Loam Soil: Lab Project Number: HRC/DPT 205/90571: AMR

1563

- 89. Unpublished study prepared by Huntingdon Research Centre Ltd. 58 p.

Aerobic soil metabolism
35273 Han, J.C.Y. (19??) Aerobic Soil Metabolism of 14C

- Phenyl Labeled DPX

- 4189: AMR

- 08

- 80 C. (Unpublished study received Jun 16, 1980 under 352

- 105; submitted by E.I. du Pont de Nemours & Co., Wil

- mington, Del.; CDL:099462

- T)
35275 Rapisarda, C. (1965?) Microbial Degradation of 14C

- Phenyl Labeled DPX

- 4189 in Soil. (Unpublished study received Jun 16, 1980 un

- der 352

- 105; submitted by E.I. du Pont de Nemours & Co., Wil

- mington, Del.; CDL:099462

- V)
83950 Rapisarda, C. (1981) Microbial Degradation of ^14IC

- DPX

- 4189 in Soil: Document No. AMR

43

- 81. (Unpublished study received Sep 1, 1981 under 352

- 403; submitted by E.I. du Pont de Nemours & Co., Wilmington, Del.; CDL:245878

- K)

### 53 86814

Rapisarda, C. (1981) Microbial Degradation of [carbon 14]

- DPX

- 4189 in Soil: Document No.
AMR

- 43

- 81. (Unpublished study received Nov 13, 1 981 under 352

- 404; prepared in cooperation with Univ. of Delaware, College of Agricultural Sciences, submitted by E.I. du Pont de Nemours & Co., Inc., Wilmington, Del.; CDL:070470

- J)
42214201 Priester, T. (1991) Aerobic Soil Metabolism of Chlorsulfuron: Lab Project Number: AMR 2213

- 91. Unpublished study prepared by E.I. du Pont de Nemours and Co. 305 p.
Anaerobic aquatic metab.
86815

Chrzanowski, R.L. (1980) Degradation of [carbon 14]

- DPX

- W4189 in Anaerobic Aquatic
Environments: Document No. AMR

- 38

- 81. (Unpublished study received Nov 13, 1981 under
352

- 404; prepared in cooperation with Univ. of Delaware, College of Agriculture, submitted by E.I. du Pont de Nemours & Co., Inc., Wilmington, Del.; CDL: 070470

- K)
Aerobic aquatic metab.
42156704 Chrzanowski, R.; Priester, T. (1991) Degradation of ?carbon 14|

- DPX

- W4189 in Anaerobic Aquatic Environments: Lab Project Number: AMR 38

- 91. Unpublished study prepared by E.I. du Pont de Nemours and Co. 45 p.
Leach/adsorp/desorption
35271

Rapisarda, C.; Shrivastava, S.P.; Butler, L.D. (1978?) Physical Properties of DPX

- 4189: Octanol/Water Partition Ratio, Solubili

- ties, and Soil Absorption Data. (Unpublished study received Jun 16, 1980 under 352

- 105; submitted by E.I. du Pont de Nemours & Co., Wilmington , Del.; CDL:099462

- R)
35272 Chrzanowski, R.L. (1974) Soil Column Absorption Studies with 14C

- DPX

- 4189 Herbicides on Soils. (Unpublished study received Jun 16, 1980 under 352

- 105; submitted by E.I. du Pont de Nemours & Co., Wilmington, Del.; CDL:099462

- S)
83948

Rapisarda, C.; Shrivastava, S.P.; Butler, L.D. (1980?) Physical Properties of DPX

- 4189: Octanol/Water Partition Ratio, Solubilities, and Soil Adsorption Data [K

- values and TLC (Rf) Values]: Document No. AMR

- 28

- 81. (Unpublished study received Sep 1, 1981 under 352

- 403; submitted by E.I. du Pont de Nemours & Co., Wilmington, Del.; CDL:245878

- I)
83949 Chrzanowski, R.L. (1980?) Soil Column Leaching Studies with ?^14IC|

- DPX

- 4189: Document
No. AMR

- 26

- 81. (Unpublished study received Sep 1, 1981 under 352

- 403; submitted by E.I. du Pont de Nemours & Co., Wilmington, Del.; CDL:245878

- J)
86816

Chrzanowski, R.L. (1980) Soil Column Leaching Studies with (Carbon

- 14)|

- DPX

- 4189:
Document No. AMR

- 26

- 81. (Unpublished study received Nov 13, 1981 under 352

- 404; p repared in cooperation with Univ. of Delaware, College of Agricultural Sciences, submitted by E.I. du Pont de Nemours & Co., Inc., Wilmington, Del.; CDL:070470

- L)
42156705

Priester, T.; Sheftic, G. (1989) Batch Equilibrium (Adsorption/Desorption) with (carbon 14)
Chlorsulfuron and Soil Thin

- Layer Chromatography Studies with (carbon 14)Chlorsulfuron and its Major Soil Degradates: Lab Project Number: AMR

- 1277

- 88. Unpublished study prepared by E. I. du Pont de Nemours & Co., Inc. 58 p.
45371826 Weber, J.; Miller, C. (1999) Organic Chemical Movement Over and Through Soil. Unpublished study prepared by North Carolina State University and University of North Carolina. 33 p.

### 54 46155803 Yeomans, P.; Swales, S. (2000) (Carbon 14) IN

- A4098: Adsorption/Desorption in Soil. Project Number: DUPONT/3832, 3832, 550/80. Unpublished study prepared by Covance Laboratories, Ltd. 52 p.
Terrestrial field dissipation
35274 E.I. du Pont de Nemours & Company (1979) Field Soil Disappearance Studies with 14C

- Labeled
DPX

- 4189. (Unpublished study received Jun 16, 1980 under 352

- 105; CDL:099462

- U)
86817 Han, J.C.Y. (1981) 14C

- DPX

- W4189 Soil Disappearance Studies in the Field: Document No.
AMR

- 54

- 81. (Unpublished study received Nov 13, 1981 under 352

- 404; submitted by E.I. du
Pont de Nemours & Co., Inc., Wilmington, Del.; CDL:070470

- M)
41714401

Dietrich, R.; Taylor, G. (1990) Field Soil Dissipation of (Phenyl (U)

- (Carbon 14)) Chlorsulfuron and (Triazine

- 2

- (Carbon 14)) Chlosulfuron in Madera, California: Lab Project Number: AMR

1417

- 89: EF

- 89

- 03. Unpublished study prepared by E. I. du Pont de Nemours and Co. in
Association with Pan

- Agricultural Laboratories, Inc. 66 p.
42214202 Djanegara, T. (1991) Field Soil Dissipation Studies of Chlorsulfuron: Lab Project Number:
AMR 2205

- 91. Unpublished study prepared by E. I. du Pont de Nemours & Co. 229 p.
43421401 Rhodes, B. (1994) Terrestrial Field Soil Dissipation of (carbon 14)

- Chlorsulfuron: Lab Project
Number: AMR 2266

- 91. Unpublished Study Prepared by DuPont Agricultural products and University of Idaho. 99 p.
Confined rotational crop
47459401 Swanson, M. (1988) Confined Accumulation Study of [carbon 14]

- Sulfometuron Methyl of Rotational Crops. Project Number: AMR/956/87. Unpublished study prepared by DuPont Experiment Station Laboratories. 42 p.
Field rotational crop
42214203 Djanegara, T. (1991) Accumulation Studies of Chlorsulfuron in Rotational Crops: Lab Project
Number: AMR 2242

- 91. Unpublished study prepared by E. I. du Pont de Nemours & Co. 157 p.

Bioconcentration in fish
42214204 Priester, T. (1991) Fish Accumulation Potential for Chlorsulfuron: Lab Project Number: AMR
2238

- 91. Unpublished study prepared by E. I. du Pont de Nemours & Co. 61 p.
83951 Han, J.C.Y. (19??) Residue Studies with [carbon 14]

- DPX

- 4189 in Bluegill Sunfish: Document
No. AMR

- 32

- 81. (Unpublished study re

- ceived Sep 1, 1981 under 352

- 403; submitted by E.I. du Pont de Nemours & Co., Wilmington, Del.; CDL:245878

- L)

Environmental Chemistry Methods
83954

E.I. du Pont de Nemours & Company, Incorporated (19??) Determina

- tion of DPX

- 4189:
Reversed

- phase Liquid Chromatography (RPLC) Assay Method. Undated method no. C 298.0282 (R). (Unpublished study received Sep 1, 1981 under 352

- EX

- 109; CDL:245879

- E)
43406701 Battelle (1991) Metho d for the Determination of Chlorsulfuron, DPX

- A7881, DPX

- F5384,
DPX

- L5300, DPX

- M6316, and Metsulfuron Methyl in Groundwater: (Revised) Final Report: Lab Project Number: AMR 1335

- 88. Unpublished study. 66 p.

### 55 43406702 Battelle (1991) Method for the Determination of Chlorsulfuron, DPX

- A7881, DPX

- F5384,
DPX

- L5300, DPX

- M6316, and Metsulfuron Methyl in Groundwater: Supplement A to Report: Lab Project Number: AMR 1335

- 88. Unpublished study. 38 p.
Non

- Guideline

35277 Julis, A.J. (1980) The Effect of DPX

- 4189 on Microorganisms and Microbial Populations of
Soils: AMR

- 13

- 80. (Unpublished study received Jun 16, 1980 under 352

- 105; submitted by E.I. du Pont de Nemours & Co., Wilmington, Del.; CDL:099462

- X)
46017702 Mckelvey, R.; Strek, H.; Carski, H.; et. al. (2003) Registrant Error Corrections and Comments on the Agency Document "Environmental Fate and Ecological Effects Risk Assessment for Chlorsulfuron". Unpublished study prepared by: E. I. du Pont de Nemours and Co. 95 p.
46128401 McKelvey, R.; Carski , T.; Dulka, J.; et. al. (2003) Registration Error Corrections and Comments on the Agency Memorandum Entitled "Spray Drift Risks to Non

- Target Plants Associateed with Chlorsulfuron Applications". Unpublished study prepared by E. I. Du Pont De Nemours and C o., Inc. 42 p.



### 17.2. **Data submitted on E cological**  **E ffects** 

Avian Single Dose Oral Toxicity

MRID Citation Reference

35263 Hinkle, S.; Twigg, C.J. (1980) Final Report

-- Acute Oral LD50 Study in Bobwhite Quail: Project No. 201

- 538. (Unpublished study re

- ceived Jun 16, 1980 under 352

- 105; prepared by Hazleton Labora

- tories America, Inc., submitted by E.I. du Pont de
Nemours & C o., Wilmington, Del.; CDL:099462

- I)

35264 Hinkle, S.; Bristol, K.L. (1980) Final Report

-- Acute Oral LD50 Study in Mallard Ducks: Project No. 201

- 525. (Unpublished study received Jun 16, 1980 under 352

- 105; prepared by Hazelton Labo

- ratories America, Inc ., submitted by E.I. du Pont de Nemours & Co., Wilmington, Del.; CDL:099462

- J)
Avian Dietary Toxicity

35265 Hinkle, S. (1979) Final Report

-- Avian Dietary Toxicity (LC50) Study in Bobwhite Quail: Project No. 201

- 523. (Unpublished study re

- ceived Jun 16, 1980 under 352

- 105; prepared by Hazleton Labora

- tories America, Inc., submitted by E.I. du Pont de
Nemours & Co., Wilmington, Del.; CDL:099462

- K)

35266 Hinkle, S.; Wentz, K.L. (1979) Final Report

-- Avian Dietary Toxicity (LC50) in Mallard Ducks: Project No. 201

- 524. (Unpublished study received Jun 16, 1980 under
352

- 105; prepared by Hazleton Laboratories America, Inc., submitted by E.I. du Pont
de Nemours & Co., Wilmington, Del.; CDL:099462

- L)

90009 Fink, R.; Beavers, J.B.; Joiner, G.; et al. (1981) Eight

- day Die

- tary LCI50^

-- Bobwhite Quail: H

- 12,700

- 02: Project No. 112

- 126; HLO

- 806

- 81. Final rept. (Unpublished study received Dec 28, 1981 under 352

- 404; prepared by Wildlife International, Ltd., submitted by E.I. du Pont de Nemours & Co., Inc., Wilmington, Del.; CDL:070534

- B)
Avian Reproduction

42634001 Beavers, J.; Foster, J.; Lynn, S.; et al. (1992) H

- 18,053 (Chlorsulfuron): A One

generation Reproducti on Study with the Northern Bobwhite (Colinus virginianus): Lab Project Number: 112

- 266: 564

- 92. Unpublished study prepared by Wildlife International Ltd. 185 p.

42634002 Beavers, J.; Foster, J.; Lynn, S.; et al. (1992) H

- 18,053 (Chlorsulfuron): A One

-

### 56 Generation Reproduction Study with the Mallard (Anas platyrhynchos): Lab Project
Number: 112

- 267: 565

- 92. Unpublished study prepared by Wildlife International Ltd. 185 p.

Acute Toxicity to Freshwater Fish

35258 Smith, E.J. (1979) 96

- Hour LC50 to Bluegill Sunfish: Haskell Labo

- ratory Report
No. 385

- 79. (Unpublished study received Jun 16, 1980 under 352

- 105; submitted by E.I. du Pont de Nemours & Co., Wilmington, Del.; CDL:099462

- D)

35259 Smith, E.J. (1979) 96

- H our LC50 to Bluegill Sunfish: Haskell Labo

- ratory Report
No. 386

- 79. (Unpublished study received Jun 16, 1980 under 352

- 105; submitted by E.I. du Pont de Nemours & Co., Wilmington, Del.; CDL:099462

- E)

35260 Smith, E.J. (1979) 96

- Hour LC50 to Fathead Min nows: Haskell Labora

- tory Report
No. 384

- 79. (Unpublished study received Jun 16, 1980 under 352

- 105; submitted by E.I. du Pont de Nemours & Co., Wilmington, Del.; CDL:099462

- F)

35261 Smith, E.J. (1979) 96

- Hour LC50 to Channel Catfish: Haskell Labora

- tory Report
No. 856

- 79. (Unpublished study received Jun 16, 1980 under 352

- 105; submitted by E.I. du Pont de Nemours & Co., Wilmington, Del.; CDL:099462

- G)

45202909 Grande, M.; Andersen, S.; Berge, D. (1994) Effects of pesticides on fish: experimental and field studies. Norwegian Journal of Agricultural Sciences Suppl.
13: 195

- 209.

47642101 Baummer, J. (2008) IN

- D5293

- 016: Static, Acute, 24

- Hours Lead Optimization Screen Using Fathead M innows, Pimephales promelas. Project Number: DUPONT/18071/206, 18071, 28795. Unpublished study prepared by E.I. du Pont de Nemours and Company. 6 p.
Acute Toxicity to Freshwater I nvertebrate s

35262 Goodman, N.C. (1979) 48

- Hour LC50 to~Daphnia magna~?: Has kell Lab

- oratory Report No. 152

- 79. (Unpublished study received Jun 16, 1980 under 352

- 105; submitted by E.I. du Pont de Nemours & Co., Wilmington, Del.; CDL:099462

- H)
Acute Toxicity to Estuarine/Marine Organisms

41976401 Ward, T.; Boeri, R. (1991) Static Acute Toxicity of DPX

- W4189

- 165 (Chlorsulfuron) to the Sheepshead Minnow, Cyprindon variegatus: Lab Project
Number: MR

- 4581

- 866: 516

- 91: 9130

- DU. Unpublished study prepared by EnviroSystems Division. 31 p.

41976402 Ward, T.; Boeri, R. (1991) Static Acute Toxicity of DPX

- W4189

- 165 (Chlorsulfuron) to the Mysid, Mysidopsis bahia: Lab Project Num

- ber: MR

- 4581

- 866: 523

- 91: 9131

- DU. Unpublished study prepared by EnviroSystems Division. 31

p.

41976403 Ward, T.; Boeri, R. (199 1) Static Acute Toxicity of DPX

- W4189

- 165 (Chlorsulfuron) to Bivalve Mollusc Embryos and Larvae: Lab Proj

- ect Number:
MR

- 4581

- 866: 524

- 91: 9132

- DU. Unpublished study prepared by EnviroSystems Division. 31 p.

42328601 Ward, T.; Boeri, R. (1991) Static Acute Toxicity of DPX

- W4189

- 165 (Chlorsulfuron) to Bivalve Mollusc Embryos and Larvae: Lab Project Number: 524

- 91: MR

- 4581

- 866. Unpublished study prepared by EnviroSystems Division, Resource Analysts, Inc. 31 p.

Fish Ear ly Life Stage/Aquat ic Invertebrate Life Cycle Studies

41976404 Ward, T.; Boeri, R. (1989) Chronic Toxicity of DPX

- W4189

- 94 to Daphnia

### 57 magna: Lab Project Number: 4581

- 655: 87

- 89. Unpublished study prepared by E.I. du Pont de Nemours and Co. 27 p.

41976405 Pierson, K. (1991) Flow

- Through 77 Day Toxicity of DPX

- W4189

- 170 to Embryo and Larval Rainbow Trout, Oncorhynchus mykiss: Lab Proj

- ect Number: 494

- 91: MR

- 4581

- 866. Unpublished study prepared by E.I. du Pont de Nemours and Co. 471 p.

41976408 Hutton, D. (1991) Chronic Toxicity of DPX

- W4189

- 94 to Daphnia magna Lab Project Number: 4581

- 655: 87

- 89. Unpublished study prepared by E.I. du Pont de Nemours and Co. 92 p.

42309701 Hutton, D. (1992) Chronic Toxicity of DPX

- W4189

- 94 to Daphnia magna: Supplement #1 : Lab Project Number: 87

- 89. Unpublished study prepared by E.I. du Pont de Nemours and Co. 8 p.
Seed Germination/Seedling Emergence and Vegetative Vigor

42201001 McKelvey, R.; Kuratle, H. (1991) Influence of Chlorsulfuron on Seed Germination, Seedling E mergence and Vegetative Vigor of Several Terrestrial Plants: Lab Project Number: AMR 2070

- 91. Unpublished study prepared by E.I. du Pont de Nemours and Co. 235 p.

42587201 McKelvey, R.; Kuratle, H. (1992) Influence of Chlorsulfuron on Seed Germination, Seedling Emergence, and Vegetative Vigor of Several Terrestrial Plants: Revision No. 1: Lab Project Number: AMR 2070

- 91. Unpublished study prepared by E.I. du Pont de Nemours and Co. 235 p.
Aquatic plant growth Tier 1

45088212 Fairchild, J.; Ruessler, D.; Haverland, P. et al. (1996) Comparative Sensitivity of Selenastrum capricornutum and Lemna minor to Sixteen Herbicides. Archives of Environmental Contamination and Toxicology 32:353

- 357.

46045201 Sloman, T. (2002) Chlorsulfur on (DPX

- W4189) 75WG: Influence on Growth and Growth Rate of the Green Alga Selenastrum capricornutum. Project Number: DUPONT/10063, 10063. Unpublished study prepared by Dupont Haskell Laboratory. 49 p.

46045202 Sloman, T. (2002) Chlorsulfuron (DPX

- W4189) 75WG: Influence on Growth and Reproduction of Lemna gibba. Project Number: DUPONT/10064, 10064, E1415/91. Unpublished study prepared by Dupont Haskell Laboratory. 49 p.
Seed germination/seedling emergence and vegetative vigor

42201001 McKelvey, R.; Kuratle, H. (1991) Influence of Chlorsulfuron on Seed Germination, Seedling Emergence and Vegetative Vigor of Several Terrestrial Plants: Lab Project Number: AMR 2070

- 91. Unpublished study prepared by E.I. du Pont de Nemours and Co. 235 p.

42587201 McKelvey, R.; Kuratle, H. (1992) Influence of Chlorsulfuron on Seed Germination, Seedling Emergence, and Vegetative Vigor of Several Terrestrial Plants: Revision No. 1: Lab Project Number: AMR 2070

- 91. Unpublished study prepared by E.I. du Pont de Nemours and Co. 235 p.
Terrestrial plant toxicity, Tier 1 (seeding emergence)

46361801 Porch, J.; Martin, K. (2004) Chlorsulfuron (DPX

- W4189) 75WG: A Greenhouse Study to Investigate the Effects on Seedling Emergence and
Growth of Ten Terrestrial Plants Following Soil Exposure. Project Number: 112/541, 14901, 1495. Unpublished study prepared by Wildlife International, Ltd. 264 p.
Terrestrial plant toxicity, Tier 1 (vegetative vigor)

### 58 46326801 Porch, J.; Martin, K. (2004) Chlorsulfuron (DPX

- W4189) 75WG: A Greenhouse Study to Investigate the Effects on Vegetative Vigor of Ten Terrestrial Plants Following Foliar Exposure. Project Number: 112/542, DUPONT/13552, 14901. Unpublished study prepared by Wildlife International, Ltd. 191 p.

47845101 Porch, J.; Martin, K. (2009) Chlorsulfuron (DPX

- W4189) 75WG: A Greenhouse Rate Response Study to Investigate the Comparative Effects on Vegetative Vigor of Sugarbeet Following Foliar Exposure by High Volume and Volume Reduction Methods. Project Number: 112/622A,
DUPO NT/21982, 17791/1496. Unpublished study prepared by Wildlife International, Ltd. 77 p.
Seedling emergence, Tier II

46361801 Porch, J.; Martin, K. (2004) Chlorsulfuron (DPX

- W4189) 75WG: A Greenhouse Study to Investigate the Effects on Seedling Emergence a nd Growth of Ten Terrestrial Plants Following Soil Exposure. Project Number: 112/541, 14901, 1495. Unpublished study prepared by Wildlife International, Ltd. 264 p.
Vegetative vigor, Tier II

46326801 Porch, J.; Martin, K. (2004) Chlorsulfuron (DPX

- W4189) 75WG: A Greenhouse Study to Investigate the Effects on Vegetative Vigor of Ten Terrestrial Plants Following Foliar Exposure. Project Number: 112/542, DUPONT/13552, 14901. Unpublished study prepared by Wildlife International, Ltd. 191 p.

47845101 Porch, J.; Martin, K. (2009) Chlorsulfuron (DPX

- W4189) 75WG: A Greenhouse Rate Response Study to Investigate the Comparative Effects on Vegetative Vigor of Sugarbeet Following Foliar Exposure by High Volume and Volume Reduction Methods. Project Number: 112/622A, DUPONT/21982, 17791/1496. Unpublished study prepared by Wildlife International, Ltd. 77 p.
Aquatic plant growth

42186801 Blasberg, J.; Hicks, S.; Stratton, J. (1991) Acute Toxicity of Chlorsulfuron to Selenastrum capricornutum Printz: Final Report: Lab Project Number: AMR

2081

- 91: 39427. Unpublished study prepared by ABC Laboratories, Inc. 33

p.

45832901 Boeri, R.; Wyskiel , D.; Ward, T. (2002) Chlorsulfuron (DPX

- W4189) Technical: Influence on Growth Rate of the Duckweed, Lemna gibba: Lab Project Number: 2042

- DU: DUPONT

- 4468: ASTM E1415

- 91. Unpublished study prepared by T.R. Wilbury Laboratories. 38 p.

45832902 Boeri, R.; Wyskiel, D.; Ward, T. (2001) Chlorsulfuron (DPX

- W4189) Technical: Influence on Growth and Growth Rate of the Alga, Skeletonema costatum: Lab Project Number: 2043

- DU: DUPONT

- 4465. Unpublished study prepared by T.R. Wilbury Laboratories. 37 p.

45832903 Boe ri, R.; Wyskiel, D.; Ward, T. (2001) Chlorsulfuron (DPX

- W4189) Technical: Influence on Growth and Growth Rate of Alga, Anabaena flos

aquae: Lab Project Number: DUPONT

- 4466: 2044

- DU. Unpublished study prepared by T.R. Wilbury Laboratories. 38 p.

45832904 Boeri, R.; Wyskiel, D.; Ward, T. (2001) Chlorsulfuron (DPX

- W4189) Technical: Influence on Growth and Growth Rate of the Alga, Navicula pelliculosa: Lab Project Number: DUPONT

- 4467: 2045

- DU. Unpublished study prepared by T.R. Wilbury Laboratories. 37 p.

### 59 Honeybee Toxicity

42129902 Hoxter, K.; Lynn, S. (1991) H (No.)18,053: An Acute Contact Toxici

- ty Study with the Honey Bee: Lab Project Number: 112

- 260: 690

- 91. Unpublished study prepared by Wildlife International Ltd. 15 p

.

### 60 Appendix A

. List of Registered Products Contain in g Chlorsulfuron and Percent Active Ingredients

# EPA Reg.
# Name Percent Chlorsulfuron

1 352

- 516 DUPONT CHLORSULFURON TECHNICAL 98

2 228

- 375 RIVERDALE CORSAIR SELECTIVE
HERBICIDE 75

3 228

- 600 NUP 08136 15
48 Metsulfuron

4 228

- 672 NUFARM CHLORSULF SPC 75 WDG
HERBICIDE 75

5 228

- 673 ETI 123 01 H

- D2 75

6 228

- 676 ETI 122 01 H

- D 62.5
12.5 Metsulfuron

7 352

- 445 DUPONT FINESSE HERBICIDE 62.5
12.5 Metsulfuron

8 352

- 522 DUPONT GLEAN FERTILIZER
COMPATIBLE HERBICIDE 75

9 352

- 645 DUPONT LANDMARK XP HERBICIDE 25
50 Sulfometuron

10 352

- 653 DUPONT GLEAN XP HERBICIDE 75

11 352

- 654 DUPONT TELAR XP HERBICIDE 75

12 352

- 669 DUPONT CIMARRON X

- TRA HERBICIDE 37.5
30 Metsulfuron

13 352

- 670 DUPONT CIMARRON PLUS HERBICIDE 15
48 Metsulfuron

14 352

- 712 DUPONT THROTTLE MP HERBICIDE 9
48 Sulfentrazone
18 Sulfometuron

15 352

- 718 DUPONT FINESSE GRASS & BROADLEAF
HERBICIDE 25
46.7 Flucarbazone

- sodium

16 352

- 725 DUPONT THROTTLE XP HERBICIDE 9
18 Sulfometuron
48 Sulfentrazone

17 352

- 827 DUPONT FINESSE CEREAL AND
FALLOW HERBICIDE 62.5
12.5 Metsulfuron

18 352

- IUL DUPONT PLAINVIEW HERBICIDE 9.4
18.7 Sulfmeturon 31.2 Aminocyclopyrachlor

19 352

- 846 DUPONT PERSPECTIVE HERBICIDE 15.8
39.5 Aminocyclopyrachlor

20 352

- ILR DUPONT PERSPECTIVE R&P HERBICIDE 15.8

### 61 # EPA Reg.
# Name Percent Chlorsulfuron

39.5 Aminocyclopyrachlor

21 34704

- 1004 LPI CHLOR

- METSUL 62.5
12.5 Metsulfuron

22 67760

- 79 CHEMINOVA CHLORSULFURON
TECHNICAL 98.3

23 67760

- 80 CHISUM HERBICIDE 15
48 Metsulfuron

24 67760

- 81 REPORT HERBICIDE 75

25 67760

- 82 REPORT EXTRA HERBICIDE 62.5
12.5 Metsulfuron

26 67760

- 98 CHI

- CHLORSUL NC

- 75 HERBICIDE 75

27 71368

- 91 NUP 08135 62.5
12.5 Metsulfuron

28 71368

- 92 NUP 08134 75

29 71368

- 94 NUP

- 08111 FC HERBICIDE 75

30 71368

- 95 NUP

- 08113 HERBICIDE 15
48 Metsulfuron

31 71368

- 96 NUP

- 08111 HERBICIDE 75

32 71368

- 97 NUP

- 08112 HERBICIDE 62.5
12.5 Metsulfuron

33 81927

- 43 ALLIGARE CHLORSULFURON 75 75

34 84930

- 17 ARC CHLORMET HERBICIDE 62.5
12.5 Metsulfuron

35 85588

- 9 CHLORMET HERBICIDE 62.5
12.5 Metsulfuron

36 85588

- 17 CHLORMET XP HERBICIDE 62.5
12.5 Metsulfuron

### 62 Appendix B

. E COSAR and ASTER Output

Chlorsulfuron SMILES : CLc1ccccc1S(=O)(=O)NC(=O)Nc2nc(nc(OC)n2)C
CHEM :
CAS Num:
ChemID1:
ChemID2:
ChemID3:
MOL FOR: C12 H12 CL1 N5 O4 S1
MOL WT : 357.77 Log Kow: 2.26 (KowWin estimate)
Melt Pt: Wat Sol: 3.1E+004 mg/L (experimental database)

ECOSAR v1.00 Class(es) Found

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

=========================== ================== ======== ====== ========== Tria zines : Fish 96

- hr LC50 73.573 Triazines : Daphnid 48

- hr LC50 56.449 Triazines : Green Algae 96

- hr EC50 19.763
Triazines : Fish ChV 15.601 ! Triazines : Daphnid 21

- day ChV 6.477 Triazines : Green Algae ChV 6.232

Amides : Fish 96

- hr LC50 28.568 Amides : Daphnid 48

- hr LC50 17.617 Amides : Green Algae 96

- hr EC50 0.664
Amides : Fish ChV 0.1 69 Amides : Daphnid ChV 0.232 ! Amides : Green Algae ChV 0.598

Sulfonyl Ureas : Daphnid 48

- hr LC50 54.403 Sulfonyl Ureas : Green Algae 96

- hr EC50 0.040 Sulfonyl Ureas : Daphnid ChV 5.398 ! Sulfonyl Ureas : Green Algae ChV 0.010 !

=========================== ========== ======== ======== ====== ========== Neutral Organic SAR : Fish 96

- hr LC50 165.297 (Baseline Toxicity) : Daphnid 48

- hr LC50 98.456 : Green Algae 96

- hr EC5 0 47.272
: Fish ChV 15.601 : Daphnid ChV 9.526 : Green Algae ChV 17.948

Note: * = asterisk designates: Chemical may not be soluble enough to measure this predicted effect.

Note: ! = exclamation designates: The toxicity value was determined from a predicted SAR using established acute

- to

- chronic ratios and ECOSAR

### 63 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.

Triazines:

---------

For Fish and Daphnid Acute Toxicity Values: If the log Kow of the chemical is greater than 5.0, or if the compound 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

Sulfonyl Ureas :

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

For Fish and Daphnid Acute Toxicity Values: If the log Kow of the chemical is greater than 5.0, or if the compound is solid and the LC50 exceeds t he 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)

### 64 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

ODMC

SMILES : CLc1c(cccc1)S(=O)(=O)NC(=O)Nc2nc(nc(n2)C)O
CHEM :
CAS Num:
ChemID1:
ChemID2:
ChemID3:
MOL FOR: C11 H10 CL1 N5 O4 S1
MOL WT : 343.75 Log Kow: 1.20 (KowWin estimate)
Melt Pt: Wat Sol: 632.2 mg/L (WskowWin estimate)

ECOSAR v1.00 Class(es) Found

------------------------------ Phenols
Triazines
Amides Sulfony l Ureas
Phenol Amines
Predicted ECOSAR Class Organism Duration End Pt mg/L (ppm)

=========================== ================== ======== ====== ========== Phenols : Fish 96

- hr LC50 195.832
Phenols : Fish 14

- day LC50 1324.549 * Phenols : Daphnid 48

- hr LC50 50.743
Phenols : Green Algae 96

- hr EC50 252.136
Phenols : Fish 30

- day ChV 11.325
Phenols : Fish 60

- day ChV 0.010 Phenols : Daphnid 21

- day ChV 9.666 Phenols : Green Algae ChV 119.649 Phenols : Fish (SW) 96

- hr LC50 233.334
Phenols : Earthworm 14

- day LC5 0 675.142 *
Phenols : Lemna Gibba 7

- day EC50 209.243

Triazines : Fish 96

- hr LC50 1368.476 * Triazines : Daphnid 48

- hr LC50 470.759
Triaz ines : Green Algae 96

- hr EC50 82.778
Triazines : Fish ChV 120.468 ! Triazines : Daphnid 21

- day ChV 33.238
Triazines : Green Algae ChV 19.025

Amides : Fish 96

- hr LC50 188.348 Amides : Daphnid 48

- hr LC50 80.609 Amides : Green Algae 96

- hr EC50 1.258
Amides : Fish ChV 1.113

### 65 Amides : Daphnid ChV 1.063 ! Amides : Green Algae ChV 0.57 4

Sulfonyl Ureas : Daphnid 48

- hr LC50 286.408 Sulfonyl Ureas : Green Algae 96

- hr EC50 0.038 Sulfonyl Ureas : Daphnid ChV 26.794 ! Sulfonyl Ureas : Green Algae ChV 0.010 !

Phenol Amines : Fish 96

- hr LC50 27.068 Phenol Amines : Daphnid 48

- hr LC50 2.656 Phenol Amines : Green Algae 96

- hr EC50 11.734
Phenol Amines : Fish ChV 1.608 ! Phenol Amines : Daphnid 21

- day ChV 0.999 Phenol Amines : Green Algae ChV 1.943

=========================== ================== ======== ====== ========== Neutral Organic SAR : Fish 96

- hr LC50 1246.913 * (Baseline Toxicity) : Daphnid 48

- hr LC50 653.564 * : Green Algae 96

- hr EC50 203.322
: Fish ChV 120.468 : Daphnid ChV 52.447
: Gr een Algae ChV 63.639

Note: * = asterisk designates: Chemical may not be soluble enough to measure this predicted effect.

Note: ! = exclamation designates: The toxicity value was determined from a predicted SAR u sing 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

Triazines:

---------

For Fish and Daphnid Acute Toxicity Values: If the log Kow of the chemical is greater than 5.0, or if the compound is solid and the LC50 exceeds the
water solub ility 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

### 66 greater than 6.4, or if the compound is solid and the EC50 exceeds the water solubility by 10X, no effect s 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

Sulfonyl Ureas :

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

For Fish and Daphnid Acute Toxicity Values: If the log Kow of the chemical is greater than 5.0, or if the compound 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 s olid 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)

### 67 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

ROC

SMILES : c1cccc(c1CL)S(NC(=O)(NC(=O)(NC(=O)(NCC))))(=O)=O
CHEM :
CAS Num:
ChemID1:
ChemID2:
ChemID3:
MOL FOR: C11 H13 CL1 N4 O5 S1
MOL WT : 348.76 Log Kow: 2.86 (KowWin estimate)
Melt Pt: Wat Sol: 22.79 mg/L (WskowWin estimate)

ECOSAR v1.00 Class(es) Found

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

=========================== == ================ ======== ====== ========== Imides : Fish 96

- hr LC50 21.653 Imides : Daphnid 48

- hr LC50 25.630 * Imides : Green Algae 96

- hr EC50 2.570
Imides : Fish ChV 2.106 ! Imides : Daphnid ChV 2.341 ! Imides : Green Algae ChV 1.311

Amides : Fish 96

- hr LC50 9.391 Amides : Daphnid 48

- hr LC50 7.117 Amides : Green Algae 96

- hr EC50 0.442
Amides : Fish ChV 0.056 Amides : Daphnid ChV 0.094 ! Amides : Green Algae ChV 0.583

Sulfonyl Ureas : Daphnid 48

- hr LC50 20.305 Sulfonyl Ureas : Green Algae 96

- hr EC50 0.039 Sulfonyl Ureas : Daphnid ChV 2.083 ! Sulfonyl Ureas : Green Algae ChV 0.010 !

=========================== ================== ======== ====== ========== Neutral Organic SAR : Fish 96

- hr LC50 50.361 * (Baseline Toxicity) : Daphnid 48

- hr LC50 32.241 *

### 68 : Green Algae 96

- hr EC50 19.776
: Fish ChV 4.691 : Daphnid ChV 3.467 : Green Algae ChV 8.373

Note: * = asterisk designates: Chemical may not be soluble enough to measure this predicted effect.

Note: ! = exclamation designates: The toxicity value was determined from a predicted S AR 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.

Imides:

------

For Fish and Daphnid Acute Toxicity Values: If the log Kow of the chemical is greater than 5.0, or if the compound 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 Toxic ity 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

Sulfonyl Ureas :

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

For Fish and Daphnid Acute Toxicity Values: If the log Kow of the chemical is greater than 5.0, or if the compound 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 s aturation are predicted for these endpoints.

### 69 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 th ese 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

CPSU SMILES : c1cccc(c1CL)S(NON)(=O)=O
CHEM :
CAS Num:
ChemID1:
ChemID2:
ChemID3:
MOL FOR: C6 H7 CL1 N2 O3 S1
MOL WT : 222.65 Log Kow:

- 1.74 (KowWin estimate)
Melt Pt: Wat Sol: 1E+006 mg/L (WskowWin estimate)

ECOSAR v1.00 Class(es) Found

------------------------------ Aliphatic Amines
Amides
Predi cted ECOSAR Class Organism Duration End Pt mg/L (ppm)

=========================== ================== ======== ====== ========== Aliphatic Amines : Fish 96

- hr LC50 6935.824 Aliphatic Amines : Daphnid 48

- hr LC50 323.221 Aliphatic Amines : Green Algae 96

- hr EC50 41.178 Aliphatic Amines : Fish ChV 87.064 Aliphatic Amines : Daphnid ChV 0.061 Aliphatic Amines : Green Algae ChV 44.049 Aliphatic Amines : Fish (SW) 96

- hr LC50 7161.330 Aliphatic Amines : Mysid Shrimp (SW) 96

- hr LC50 336.394 Aliphatic Amines : Green Algae (SW) 96

- hr EC50 40.947 Aliphatic Amines : Fish (SW) ChV 87.064 Aliphatic Amines : Mysid Shrimp (SW) ChV 0.061 Aliphatic Amines : Green Algae (SW) ChV 37.399

Amides : Fish 96

- hr LC50 25929.938 Amides : Daphnid 48

- hr LC50 4016.072
Amides : Green Algae 96

- hr EC50 5.382
Amides : Fish ChV 153.286

### 70 Amides : Daphnid ChV 52.979 ! Amides : Green Algae ChV 0.372

=========================== ================== ======== ====== ========== Neutral Organic SAR : Fish 96

- hr LC50 2.5e+005 (Baseline Toxicity) : Daphnid 48

- hr LC50 91699.672 : Green Algae 96

- hr EC50 8528.177
: Fish ChV 25745.279 : Daphnid ChV 4373.101 : Green Algae ChV 1559.670

Note: * = asterisk designates: Chemical may not be soluble enough to measure this predicted 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 evidenc e approach.

Aliphatic Amines:

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

For Fish 96

- hr LC50: For aliphatic amines with log Kow greater than 7.0, a test duration of greater than 96 hrs may be required for proper expression of toxicity. Also, if the toxicity value obtained by th e use of this equation exceeds the water solubility (measured or estimated), mortalities greater than 50% would not be expected in a saturated solution during an exposure period of 96 hrs.

For Daphnid 48

- hr LC50: For aliphatic amines with log Kow great er than 5.0, a test duration of greater than 48 hrs may be required for proper expression of toxicity. Also, if the toxicity value obtained by the use of this equation exceeds the water solubility (measured or estimated), significant mortalities would not be expected in a saturated solution during an exposure period of 48 hrs.

For Green Algae Acute Toxicity Values: If the log Kow of the chemical is greater than 7, 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 Mysid Shrimp Acute Toxicity Values: If the log Kow of the chemical is greater than 6, or if the compound is solid and the EC50 exceeds the water solubility by 10X, no effects at saturation are predic ted for these endpoints.

For Fish and Daphnid 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.

For Green Algae Chronic Toxicity Values: If the log Kow of the chemical is greater than 7.0, 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: 6.0 (Fish, Mysid LC50) Maximum LogKow: 5.0 (Daphnid LC50)

### 71 Maximum LogKow: 7.0 (Green Algae EC50) Maximum LogKow: 8.0 (Fish, Daphnid ChV) Maximum LogKow: 7.0 (Green Algae 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

Chlorosulfonamide SMILES : c1cccc(c1CL)S(N)(=O)=O
CHEM :
CAS Num:
ChemID1:
ChemID2:
ChemID3:
MOL FOR: C6 H6 CL1 N1 O2 S1
MOL WT : 191.63 Log Kow: 1.01 (KowWin estimate)
Melt Pt: Wat Sol: 1.126E+004 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 14 8.411 Amides : Daphnid 48

- hr LC50 59.482 Amides : Green Algae 96

- hr EC50 0.792
Amides : Fish ChV 0.877
Amides : Daphnid ChV 0.785 ! Amides : Green Algae ChV 0.320

=========================== ================== ======== ====== ========== Neutral Organic SAR : Fish 96

- hr LC50 1006.577 (Baseline Toxicity) : Daphnid 48

- hr LC50 515.613 : Green Algae 96

- hr EC50 148.375
: Fish ChV 97.657 : Daphnid ChV 40.009 : Green Algae ChV 44.857

### 72 Note: * = asterisk designates: Chemical may not be soluble enough to measure t his predicted 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
Re ference 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)
Ma ximum 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

OHCSM SMILES : c1cc(cc(c1CL)S(N)(=O)=O)O
CHEM :
CAS Num:
ChemID1:
ChemID2:
ChemID3:
MOL FOR: C6 H6 CL1 N1 O3 S1
MOL WT : 207.63 Log Kow: 0.53 (KowWin estimate)
Melt Pt: Wat Sol: 5.311E+004 mg/L (WskowWin estimate)

ECOSAR v1.00 Class(es) Found

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

=========================== = ================= ======== ====== ========== Phenols : Fish 96

- hr LC50 366.152
Phenols : Fish 14

- day LC50 3077.110 Phenols : Daphnid 48

- hr LC50 73.492 Phenols : Green Algae 96

- hr EC50 389.742
Phenols : Fish 30

- day ChV 17.217
Phenols : Fish 60

- day ChV 0.0 06 Phenols : Daphnid 21

- day ChV 14.014 Phenols : Green Algae ChV 186.525 Phenols : Fish (SW) 96

- hr LC50 655.371

### 73 Phenols : Earthworm 14

- day LC50 766.474
Phenols : Lemna Gibba 7

- day EC50 482.513

Amides : Fish 96

- hr LC50 385.550 Amides : Daphnid 48

- hr LC50 130.909 Amides : Green Algae 96

- hr EC50 1.168
Amides : Fish ChV 2.279 Amides : Daphnid ChV 1.727 ! Amides : Green Algae ChV 0.347

Phenol Amines : Fish 96

- hr LC50 29.939 Phenol Amines : Daphnid 48

- hr LC50 2.059
Phenol Amines : Green Algae 96

- hr EC50 12.699
Phenol Amines : Fish ChV 2.376 ! Phenol Amines : Daphnid 21

- day ChV 1.235 Phenol Amines : Green Alga e ChV 1.905

=========================== ================== ======== ====== ========== Neutral Organic SAR : Fish 96

- hr LC50 2779.821 (Baseline Toxicity) : Daphnid 48

- hr LC 50 1343.641 : Green Algae 96

- hr EC50 317.504
: Fish ChV 272.574 : Daphnid ChV 95.772 : Green Algae ChV 87.931

Note: * = asterisk designates: Chemical may not be soluble enough to measure this predicted effect.

Note: ! = exclamation designates: The toxicity value was determi ned 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 o f 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 effect s 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 EC 50 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:

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

### 74 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

TA SMILES : c1(nc(nc(n1)C)N)OC
CHEM :
CAS Num:
ChemID1:
ChemID2:
ChemID3:
MOL FOR: C5 H8 N4 O1
MOL WT : 140.15 Log Kow: 1.26 (KowWin estimate)
Melt Pt: Wat Sol: 6982 mg/L (WskowWin estimate)

ECOSAR v1.00 Class(es) Found

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

=========================== ================== ======== ====== ========== Anilines (Aromatic Amines) : Fish 96

- hr LC50 49.036 Anilines (Aromatic Amines) : Fish 14

- day LC50 93.947 Anilines (Aromatic Amines) : Daphnid 48

- hr LC50 1.861 Anilines (Aromatic Amines) : Green Algae 96

- hr EC50 7.741 Anilines (Aromatic Amines) : Fish ChV 0.206 Anilines (Aromatic Amines) : Daphnid ChV 0.036 Anilines (Aromatic Amines) : Green Algae ChV 5.013

Triazines : Fish 96

- hr LC50 474.380 Triazines : Daphnid 48

- hr LC50 170.514

### 75 Triazines : Green Algae 96

- hr EC50 31.135
Triazines : Fish ChV 43.819 ! Triazines : Daphnid 21

- day ChV 12.364 Triazines : Green Algae ChV 7.281

=========================== ================== ======== ====== ========== Neutral Organic SAR : Fish 96

- hr LC50 454.133 (Baseline Toxicity) : Daphnid 48

- hr LC50 239.704 : Green Algae 96

- hr EC50 76.364
: Fish ChV 43.819 : Daphnid ChV 19.433
: Green Algae ChV 24.156

Note: * = asterisk designates: Chemical may not be soluble enough to measure this predicted 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 (Ar omatic 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 tetrabrom

aniline may be 20 times toxic than predicted by this SAR.

N

- Substituted anilines are less toxic 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

Triazines:

---------

For Fish and Daphnid Acute Toxicity Values: If the log Kow of the chemical is greater than 5.0, or if the compound is solid and the LC50 exceeds the water solubility by 10X, no effect s 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 pre dicted 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

### 76 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

OHTA SMILES : c1(nc(nc(n1)C)N)O
CHEM :
CAS Num:
ChemID1:
ChemID2:
ChemID3:
MOL FOR: C4 H6 N4 O1
MOL WT : 126.12 Log Kow: 0.21 (KowWin estimate)
Melt Pt: Wat Sol: 6.36E+004 mg/L (WskowWin estimate)

ECOSAR v1.00 Class(es) Found

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

=========================== ================== ======== ====== ========== Anilines (Aromatic A mines) : Fish 96

- hr LC50 156.785 Anilines (Aromatic Amines) : Fish 14

- day LC50 1173.842 Anilines (Aromatic Amines) : Daphnid 48

- hr LC50 2.720 Anilines (Aromatic Amines) : Green Algae 96

- hr EC50 8.773 Anilines (Aromatic Amines) : Fish ChV 1.057 Anilines (Aromatic Amines) : Daphnid ChV 0.072 Anilines (Aromatic Amines) : Green Algae ChV 6.142

Phenols : Fish 96

- hr LC50 387.619
Phenols : Fish 14

- day LC50 3624.494 Phenols : Daphnid 48

- hr LC50 68.620
Phenols : Green Algae 96

- hr EC50 375.745
Phenols : Fish 30

- day ChV 16.463
Phenols : Fish 60

- day ChV 0.004 Phenols : Daphnid 21

- day ChV 13.092 Phenols : Green Algae ChV 180.578 Phenols : Fish (SW) 96

- hr LC50 847.462
Phenols : Earthworm 14

- day LC50 634.912

### 77 Phenols : Lemna Gibba 7

- day EC50 566.281

Triazines : Fish 96

- hr LC50 8264.440 Triazines : Daphnid 48

- hr LC50 1331.906
Triazines : Green Algae 96

- hr EC50 122.145
Triazines : Fish ChV 316.924 ! Triazines : Daphnid 21

- day ChV 59.425
Triazines : Green Al gae ChV 20.817

Phenol Amines : Fish 96

- hr LC50 24.484 Phenol Amines : Daphnid 48

- hr LC50 1.414 Phenol Amines : Green Algae 96

- hr EC 50 10.275
Phenol Amines : Fish ChV 2.241 ! Phenol Amines : Daphnid 21

- day ChV 1.067 Phenol Amines : Green Algae ChV 1.468

=========================== ================== ======== ====== ========== Neutral Organic SAR : Fish 96

- hr LC50 3208.659 (Baseline Toxicity) : Daphnid 48

- hr LC50 1490.360 : Green Algae 96

- hr EC50 307.638
: Fish ChV 316.924 : Daphnid ChV 100.217 : Green Algae ChV 80.224

Note: * = asterisk designates: Chemical may not be soluble enough to measure this predicted 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.

For Daphnid and Green Algae Toxi city Values: Tetrachloro

- and tetrabrom

aniline may be 20 times toxic than predicted by this SAR.

N

- Substituted anilines are less toxic 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

Phenols:

-------

### 78 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

Triazines:

---------

For Fish and Daphnid Acute Toxicity Values: If the log Kow of the chemical is greater than 5.0, or if the compound is solid and the LC 50 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

so lubility 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) 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 Li mitations:

--------------------------------- Maximum LogKow: 5.0 (Fish 96

- hr LC50; Daphnid LC50) Maximum LogKow: 6.4 (Green Algae EC50) Maximum LogKow: 8.0 (ChV)

### 79 Maximum Mol Wt: 1000

DT SMILES : c1(nc(nc(n1)O)C)O
CHEM :
CAS Num:
ChemID1:
ChemID2:
ChemID3:
MOL FOR: C4 H5 N3 O2
MOL WT : 127.10 Log Kow: 0.89 (KowWin estimate)
Melt Pt: Wat Sol: 1.652E+004 mg/L (WskowWin estimate)

ECOSAR v1.00 Class(es) Found

------------------------------ Triazines Phenols, Poly
Predicted ECOSAR Class Organism Duration End Pt mg/L (ppm)

=========================== ================== ======== ====== ========== Triazines : Fish 96

- hr LC50 1235.114 Triazines : Daphnid 48

- hr LC50 333.698 Triazines : Green Algae 96

- hr EC50 47.687
Triazines : Fish ChV 83.438 ! Triazines : Daphnid 21

- day ChV 20.356 Triazines : Green Algae ChV 9.964

Phenols, Poly : Fish 96

- hr LC50 53.625 Phenols, Poly : Daphnid 48

- hr LC50 382.571 Phenols, Poly : Green Algae 96

- hr EC50 1.358 Phenols, Poly : Fish 30

- day ChV 20.450 Phenols, Poly : Daphnid 21

- day ChV 153.074 Phenols, Poly : Green Algae ChV 0.719

=========================== ================== ======== ====== ========== Neutral Organic SAR : Fish 96

- hr LC50 857.570 (Baseline Toxicity) : Daphnid 48

- hr LC50 432.514 : Green Algae 96

- hr EC50 118.070
: Fish ChV 83.438 : Daphnid ChV 32.807 : Green Algae ChV 34.868

Note: * = asterisk designates: Chemical may not be soluble enough to measure this predicted 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 Manua l. When possible, this toxicity value should be considered in a weight of evidence approach.

Triazines:

---------

For Fish and Daphnid Acute Toxicity Values: If the log Kow of the chemical

### 80 is greater than 5.0, or if the compound is solid and the L C50 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

Phenols, Poly :

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

For Fish A cute Toxicity Values: If the log Kow of the chemical is greater than 7.0, or if the compound is solid and the LC50 exceeds the water solubility by 10X, no effects at saturation are predicted for these endpoints.

For Daphnid Acute Toxicity Values: If th e log Kow of the chemical is greater than 5.5, or if the compound 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 chemic al 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: 7.0 (Fish LC50) Maximum LogKow: 5.5 (Daphnid LC 50) 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

TU SMILES : c1(nc(nc(n1)OC)NC(=O)(N))C

### 81 CHEM :
CAS Num:
ChemID1:
ChemID2:
ChemID3:
MOL FOR: C6 H9 N5 O2
MOL WT : 183.17 Log Kow: 0.89 (KowWin estimate)
Melt Pt: Wat Sol: 9174 mg/L (WskowWin estimate)

ECOSAR v1.00 Class(es) Found

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

=========================== ================== ======== ====== ========== Substituted Ureas : Fish 96

- hr LC50 335.991 Substituted Ureas : Daphnid 48

- hr LC50 748.598
Substituted Ureas : Green Algae 96

- hr EC50 0.131
Substituted Ureas : Fish ChV 4.645 Substituted Ureas : Daphnid ChV 51.317 Substituted Ureas : Green Algae ChV 0.038 !

Triazines : Fish 96

- hr LC50 1745.865 Triazines : Daphnid 48

- hr LC50 474.167 Triazines : Green Algae 96

- hr EC50 68.066
Triazines : Fish ChV 118.619 ! Triazines : Daphnid 21

- day ChV 29.016 Triazines : Green Algae ChV 14.251

Amides : Fish 96

- hr LC50 177.021 Amides : Daphnid 48

- hr LC50 68.031 Amides : Green Algae 96

- hr EC50 0.819
Amides : Fish ChV 1.046 Amides : Daphnid ChV 0.897 ! Amides : Green Algae ChV 0.306

=========================== ================== ======== ====== ========== Neutral Organic SAR : Fish 96

- hr LC50 1219.356 (Baseline Toxicity) : Daphnid 48

- hr LC50 615.494 : Green Algae 96

- hr EC50 168.497
: Fish ChV 118.619 : Daphnid ChV 46.744 : Green Algae ChV 49.822

Note: * = asterisk designat es: Chemical may not be soluble enough to measure this predicted effect.

Note: ! = exclamation designates: The toxicity value was determined from a predicted SAR using established acute

- to

- chronic ratios and ECOSAR regression techniqu es which are documented in the supporting Technical Reference Manual. When possible, this toxicity value should be considered in a weight of evidence approach.

### 82 Substituted Ureas:

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

For Fish and Daphnid Acute Toxicity Values: I f the log Kow of the chemical is greater than 5.0, or if the compound 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 ch emical 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)
Maxi mum LogKow: 8.0 (ChV)
Maximum Mol Wt: 1000

Triazines:

---------

For Fish and Daphnid Acute Toxicity Values: If the log Kow of the chemical is greater than 5.0, or if the compound 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 predicte d 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.

ECOSA R 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:

### 83 --------------------------------- Maximum LogKow: 5.0 (Fish 96

- hr LC50; Daphnid LC50) Maximum LogKow: 6.4 (Gr een Algae EC50) Maximum LogKow: 8.0 (ChV)
Maximum Mol Wt: 1000

AB SMILES : O=C(N)(NC(=O)(NC(=O)(C)))
CHEM :
CAS Num:
ChemID1:
ChemID2:
ChemID3:
MOL FOR: C4 H7 N3 O3
MOL WT : 145.12 Log Kow:

- 0.43 (KowWin estimate)
Melt Pt:
Wat Sol: 1.86E+005 mg/L (WskowWin estimate)

ECOSAR v1.00 Class(es) Found

------------------------------ Imides
Amides
Predicted ECOSAR Class Organism Duration End Pt mg/L (pp m)

=========================== ================== ======== ====== ========== Imides : Fish 96

- hr LC50 3420.288 Imides : Daphnid 48

- hr LC50 3031.061
Imides : Green Algae 96

- hr EC50 17.170
Imides : Fish ChV 343.458 ! Imides : Daphnid ChV 173.596 ! Imides : Green Algae ChV 9.741

Amides : Fish 96

- hr LC50 1564.157 Amides : Daphnid 48

- hr LC50 380.466 Amides : Green Algae 96

- hr EC50 1.517
Amides : Fish ChV 9.247 Amides : Daphnid ChV 5.019 ! Amides : Green Algae ChV 0.242

========== ================= ================== ======== ====== ========== Neutral Organic SAR : Fish 96

- hr LC50 12753.230 (Baseline Toxicity) : Daphnid 48

- hr LC50 5485.136 : Green Algae 96

- hr EC50 872.098
: Fish ChV 1277.494 : Daphnid ChV 329.594 : Green Algae ChV 202.479

Note: * = asterisk designates: Chemical may not be soluble enough to measure this predicted effect.

Note: ! = exclamation designates: The toxicity value was determi ned 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 o f evidence approach.

### 84 Imides:

------

For Fish and Daphnid Acute Toxicity Values: If the log Kow of the chemical is greater than 5.0, or if the compound 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.

F or 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 Log Kow: >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

Ring

- opened Chlorsulfuron

ASTER ECOTOXICITY PROFILE
U.S. Environmental Protection Agency
Office of Research and Development National Health and Environmental Effects Research Laboratory

Mid

- Continent Ecology Division Contact: Scientific Outreach Program

218

- 529

- 5225 or FAX 218

- 529

- 5003

Internet: ecotox.support@epa.gov

The ASTER (ASsessment Tools for the Evaluation of Risk) database integrates aquatic and terrestrial toxicity database information and quantitative structure activity relationships

### 85 (QSARs) to assess the environmental risk of discrete chemicals. ASTER is des igned to provide high quality data for discrete chemicals, when available in the ECOTOX database, and mechanistically

- based QSAR estimates when data are lacking.

You should consult the original scientific paper to ensure an understanding of the context of
the data retrieved from the ECOTOX database.

I. CHEMICAL IDENTIFICATION

Parameter Value

Name

CAS Number

- 1

SMILES C1=CC=CC(=C1Cl)S(NC(NC(NC(NCC)=O)=O)=O)(=O)=O

Formula C 11 CLH 13 N 4 O 5 S

II. ENVIRONMENTAL EXPOSURE ASSESSMENT

Parameter Value Source Reference Molecular Weight (g/mole) 348.76 Calculated Melting Point (C) Not available for this chemical Boiling Point (C) 481.66 Calculated Vapor Pressure (mm of Hg) 2.36E

- 12 Calculated Ht Vaporization (cal/mole) 2.55E04 Calculated Solubility in Water (mg/L) 652.72 Calculated CLogP 0.70 CLogP 83337

KowWin 2.86** KowWin 83336
pKa Not available for this chemical Adsorption Coef (log Koc) 2.89 Calculated Henry's Constant (atm

m**3/mole) 1.66E

- 15 Calculated

Log10 (Henry's Constant)(atm

m**3/mole) - 14.78 Calculated

Hydrolysis Half

- life (days) Not available for this chemical
BioDegradation Data Linear Model Prediction : Does Not Biodegrade Fast
Non

- Linear Model Prediction: Does Not Biodegrade Fast Ultimate Biodegradation Timeframe:
Months Primary Biodegradation Timeframe:
Weeks
MITI Linear Model Prediction : Not Readily Degradable
MITI Non

- Linear Model Prediction: Not Readily Degradable
<BR< font> BioWin 83338

### 86 Mackay Level 1 Environmental Partitioning @ 25C Fugacity = 2.16E

- 15 Pa
0.00 % into air
5.17 % into soil
90.00 % into water 0.01 % into suspended solids 0.00 % into aquatic biota
4.82 % into sediment
** Denotes the LogP value used in calculations

III. ECOTOXICOLOGICAL HAZARD ASSESSMENT
Table 1. Geometric Means of all data passing the ASTER filter by Species Group

Habitat Species Effect Count Geo Mean Min Max

No Records Found

Table 2. Median Acute Data values

Habit

at Taxon Gro

up Name Endpoi

nt Effe

ct Measu

re Medi

a Dur ( d) Exposu

re Median C

onc Sour

ce Ref
No

A Fish Pimephales promelas LC50 MOR MORT FW 4 S 42049.29 ug/L 

### QSA
R 9003

A Fish Ictalurus punctatus LC50 MOR MORT FW 4 S 18141.68 ug/L 

### QSA
R 9003

A Fish Daphnia

magna LC50 MOR MORT FW 4 S 23260.33 ug/L 

### QSA
R 9003

A Fish Oncorhync hus mykiss LC50 MOR MORT FW 4 S 17458.54 ug/L QSA
R 9003

A Fish Lepomis
macrochiru

s LC50 MOR MORT FW 4 S 33276.23 ug/L QSA
R 9003

Table 3. Median Chronic Data values

Habit

at Taxon Gro

up Name Endpoi

nt Effe

ct Measu

re Medi

a Dur ( d) Exposu

re Median Co

nc Sourc

e Ref N

o

A Fish Pimephal

es promelas MATC GRO GGRO FW 4 S 6941.73 ug/L QSAR 9003

Table 4. Median Bioconcentration Data values

Habit

at Taxon Gr

oup Name Endpo
int Effe

ct Meas

ure Med
ia Dur ( d) Expos

ure Sit

e Median C

onc BCF Va
lue Sour

ce Ref
No

A Fish Pimeph
ales promela

s BCF AC
C RSDE FW 4 S W
O 72.34 QSA
R 7

Table 5. Additional Agency Benchmark Data

### 87 Habit

at Taxon Gro

up Nam

e Endpoi

nt Effec

t Measur

e Medi

a Dur (d ) Exposur

e Median Co

nc Sourc

e Ref N

o

No Records Found

IV. ECOLOGICAL RISK CHARACTERIZATION

A. Environmental Exposure Assessment
Henry's Constant = 1.66E

- 15 atm

- m**3/mole Log10 (Henry's Constant) =

- 14.78 atm

- m**3/mole

Lyman et al. 1982. would conclude that a chemical with these properties is non

- volatile. See page 15

- 15. The QSAR system does not yet model the hydrolysis of Urea derivatives like this.

B. E cotoxicological Hazard Assessment

NONPOLAR NARCOSIS The acute mode of toxic action for this class of xenobiotics is generally attributed to narcosis (the toxicologically induced and reversible stages of neural disruption, i.e. general anesthesia). Intox ication via nonpolar narcosis is thought to be the minimal effect that can be elicited by a xenobiotic and the QSAR for nonpolar narcosis provides predictions of baseline acute toxicity [3261]. Chemicals that act via a more specific mode of action, or are metabolically activated, will generally be more toxic than what would be predicted by the nonpolar narcosis QSAR. The acute toxicity modeling component in
ASTER assesses the structural characteristics of chemicals and evaluates whether or not an
entered co mpound contains specific functional moieties (or moieties capable of being bioactivated) that are associated with more specific modes of toxic action. The nonpolar narcosis QSAR is invoked only if the structural characteristics of a chemical do not suggest a more specific mode of action.
When sufficient data is available from fathead minnow early life stage (ELS) tests (32

- d exposures) completed at MED

- Duluth, QSAR models have been developed to predict chronic values for either survival or growth, which ever is the most sensitive endpoint. A chronic value is defined as the geometric mean of the LOEC (lowest observable effect concentration) and the NOEC (no observable effect concentration). These models have been developed for groups of xenobiotics that ha ve been classified based on their acute modes of toxic action. Empirical observations suggest that when a statistically robust ELS QSAR can be established
and when 96

- h LC50/32

- d ELS chronic value ratios are within a factor of 20 it is reasonable

to assume that adverse effects are elicited through the same mode of toxic action in both 4

- d and 32

- d exposures. If during a chronic exposure a different mode of action is involved, or if metabolic activation is significant, the ratios between acute and chronic en dpoint values for a group of xenobiotics are generally quite variable and typically exceed two orders of magnitude. In addition, the statistical strength of ELS QSARs in these instances are poor.

C. Other Information

Triazine Amine

08

- Aug

- 12

ASTER ECOTOXICITY PROFILE

### 88 U.S. Environmental Protection Agency
Office of Research and Development National Health and Environmental Effects Research Laboratory

Mid

- Continent Ecology Division
Contact: Scientific Outreach Program

218

- 529

- 5225 or FAX 218

- 529

- 5003

Internet: ecotox.support@epa.gov

The ASTER (ASsessment Tools for the Evaluation of Risk) database integrates aquatic and terrestrial toxicity database information and quantitative structure activity relationships (QSARs) to assess the env ironmental risk of discrete chemicals. ASTER is designed to provide high quality data for discrete chemicals, when available in the ECOTOX database, and mechanistically

- based QSAR estimates when data are lacking.

You should consult the original scienti fic paper to ensure an understanding of the context of
the data retrieved from the ECOTOX database.

I. CHEMICAL IDENTIFICATION

Parameter Value

Name

CAS Number

- 1

SMILES C1(=NC(=NC(=N1)C)N([H])[H])OC

Formula C 5 H 6 N 4 O

II. ENVIRONMENTAL EXPOSURE ASSESSMENT

Parameter Value Source Reference Molecular Weight (g/mole) 138.13 Calculated Melting Point (C) Not available for this chemical Boiling Point (C) 211.10 Calculated Vapor Pressure (mm of Hg) 0.21 Calculated Ht Vaporization (cal/mole) 1.07E04 Calculated Solubility in Water (mg/L) 2.40E04 Calculated CLogP

- 1.10 CLogP 83337

KowWin 1.26** KowWin 83336
pKa Not available for this chemical Adsorption Coef (log Koc) 2.02 Calculated Henry's Constant (atm

m**3/mole) 1.55E

- 06 Calculated

Log10 (Henry's Constant)(atm

m**3/mole) - 5.81 Calculated

Hydrolysis Half

- life (days) Hydrolysis unlikely BioDegradation Data Linear Model Prediction : 83338

### 89 Biodegrades Fast
Non

- Linear Model Prediction: Does Not Biodegrade Fast
Ultimate Biodegradation Timeframe:
Weeks

- Months Primary Biodegradation Timeframe: Days

- Weeks
MITI Linear Model Prediction : Not Readily Degradable
MITI Non

- Linear Model Prediction: Not Readily Degradable
<BR< font>
Mackay Level 1 Environmental Partitioning @ 25C Fugacity = 2.13E

- 06 Pa
5.15 % into air
0.14 % into soil
94.59 % into water 0.00 % into suspended solids 0.00 % into aquatic biota
0.13 % into sediment
** Denotes the LogP value used in calculations

III. ECOTOXICOLOGICAL HAZARD ASSESSMENT

Table 1. Geometric Means of all data passing the ASTER filter by Species Group

Habitat Species Effect Count Geo Mean Min Max

No Records Found

Table 2. Median Acute Data values

Habit

at Taxon Gro

up Name Endpoi

nt Effe

ct Measu

re Medi

a Dur ( d) Exposu

re Median C

onc Sour

ce Ref
No

A Fish Pimephales promelas LC50 MOR MORT FW 4 S 508615.0 5 ug/L 

### QSA
R 9003

A Fish Ictalurus punctatus LC50 MOR MORT FW 4 S 218687.0 7 ug/L QSA
R 9003

A Fish Daphnia

magna LC50 MOR MORT FW 4 S 236329.4 6 ug/L QSA
R 9003

A Fish Oncorhync hus mykiss LC50 MOR MORT FW 4 S 242121.5 2 ug/L QSA
R 9003

A Fish Lepomis
macrochiru

s LC50 MOR MORT FW 4 S 375895.4 8 ug/L QSA
R 9003

Table 3. Median Chronic Data values

Habit

at Taxon Gro

up Name Endpoi

nt Effe

ct Measu

re Medi

a Dur ( d) Exposu

re Median Co

nc Sourc

e Ref N

o

A Fish Pimephal

es promelas MATC GRO GGRO FW 4 S 68049.41 ug/L QSAR 9003

### 90 Table 4. Median Bioconcentration Data values

Habit

at Taxon Gr

oup Name Endpo
int Effe

ct Meas

ure Med
ia Dur ( d) Expos

ure Sit

e Median C

onc BCF Va
lue Sour

ce Ref
No

A Fish Pimeph
ales promela

s BCF AC
C RSDE FW 4 S W
O 3.94 QSA
R 7

Table 5. Additional Agency Benchmark Data

Habit

at Taxon Gro

up Nam

e Endpoi

nt Effec

t Measur

e Medi

a Dur (d ) Exposur

e Median Co

nc Sourc

e Ref N

o

No Records Found

IV. ECOLOGICAL RISK CHARACTERIZATION

A. Environmental Exposure Assessment Henry's Constant = 1.55E

- 06 atm

- m**3/mole Log10 (Henry's Constant) =

- 5.81 atm

- m**3/mole

Lyman et al. 1982. would conclude that a chemical with these properties will volatilize slowly from open water. See page 15

- 15. Hydrolysis is not likely to be an important transformation mechanism for this chemical.

B. Ecotoxicological Ha zard Assessment

NONPOLAR NARCOSIS The acute mode of toxic action for this class of xenobiotics is generally attributed to narcosis (the toxicologically induced and reversible stages of neural disruption, i.e. general anesthesia). Intoxication via nonpol ar narcosis is thought to be the minimal effect that can be elicited by a xenobiotic and the QSAR for nonpolar narcosis provides predictions of baseline acute toxicity [3261]. Chemicals that act via a more specific mode of action, or are metabolically acti vated, will generally be more toxic than what would be predicted by the nonpolar narcosis QSAR. The acute toxicity modeling component in
ASTER assesses the structural characteristics of chemicals and evaluates whether or not an entered compound contains sp ecific functional moieties (or moieties capable of being bioactivated) that are associated with more specific modes of toxic action. The nonpolar narcosis QSAR is invoked only if the structural characteristics of a chemical do not suggest a more specific m ode of action.



### Appendix C

. Ecological Toxicity Summary for Aquatic and Terrestrial Organisms from
Chlorsulfuron

Exposure Scenario Species Acute Toxicity

-- Chronic Toxicity Citation
MRID Acute Toxicity
Classification

Birds 1

Acute (Dose

- based) Bobwhite Quail ( Colinus virginianus ) LD 50 >5,000 mg a.i./kg

- bw Avian Acute
000352

- 63 (Acceptable) Practically

non

- toxic

Sub

- Acute Dietary Mallard D uck ( Anas platyrhynchos ) LC 50 >5,000 mg a.i./kg

diet Avian Dietary
000352

- 66 (Acceptable) --

### 91 Exposure Scenario Species Acute Toxicity

-- Chronic Toxicity Citation
MRID Acute Toxicity
Classification

Chronic Mallard D uck NOAEC ≥961 mg a.i./kg

- diet LOAEC >961 mg a.i./kg

- diet Avian R eproduction
426340

- 02 (Acceptable) --

Bobwhite Quail ( Colinus virginianus ) NOAEC = 174 mg a.i./kg

diet LOAEC = 961 mg a.i./kg

- diet Avian Reproduction
426340

- 01 (Acceptable) --

Mammals

Acute Laboratory R at ( Rattus norvegicus ) LD 50 >5,500 mg a.i./kg

- bw Acute Mammal
000314

- 06 (Acceptable) Practically
Non

- toxic

Chronic NOAEL = 100 mg/kg/ day
LOAEL = 500 mg/kg

- diet Chronic
000860

- 03 (Acceptable) --

Insects

Acute (contact) Honey B ee ( Apis mellifera L. ) LD 50 >25 ug a.i./bee 48

- Hour
421299

- 02 (Acceptable) Practically
Non

- toxic

Freshwater fish 2

Acute Rainbow Trout ( Oncorhynchus mykiss ) LC 50 >300 mg a.i./L 96

- Hour
000352

- 58 (Acceptable) Practically
Non

- toxic

Chronic NOAEC (length) = 32 mg a.i./L Early Life Stage
419764

- 05 (Acceptable) --

Freshwater Invertebrates

Acute
Water Flea ( Daphnia magna ) EC 50 >370 mg a.i./L 48

- Hour
000352

- 62 (Acceptable) Practically
Non

- toxic

Chronic NOAEC (reproduction ) = 20 mg a.i./L 21

- Day
419764

- 04 and

419764

- 08 (Supplemental) --

Estuarine/Marine Fish

Acute Sheepshead
Minnow ( Cyprindon varigatus ) LC 50 > 980 mg a.i./L 96

- Hour
419764

- 01 (Acceptable) Practically
Non

- toxic

Chronic NOAEC (length) = 980 mg
a.i./L ---

Estuarine/Marine Invertebrates

Acute Eastern Oyster ( Crassostrea

virginica ) EC 50 =376 mg a.i./L Static Acute
419764

- 03 (Supplemental) Practically
Non

- toxic

EC 50 =385 mg a.i./L Static Acute
423286

- 01 (Acceptable) Practically
Non

- toxic

Acute Mysid ( Mysidopsis
bahia ) LC 50 >89 mg a.i./L 96

- Hour
419764

- 02 (Acceptable) Slightly toxic

Terrestrial Plants

Monocot Onion ( Allium cepa ) EC 25 (dry wt) =
3 x 10 - 4 lb a.i./A

---- NOAEC (dry wt) =
4.5 x 10 - 5 lb a.i./A Seedling Emergence
463618

- 01 (Supplemental) ---

### 92 Exposure Scenario Species Acute Toxicity

-- Chronic Toxicity Citation
MRID Acute Toxicity
Classification

EC 25 (dry wt) =
2.2 x 10 - 5 lb a.i./A

---- E C 05 (shoot height ) =

2.6 x 10 - 6 lbs a.i./A Vegetative Vigor
463268

- 01 (Supplemental) ---

Dicot Pea ( Pisum sativum ) EC 25 = 2.2 x 10 - 5 lb a.i./A

---- NOAEC = 1.8 x 10 - 4 lb a.i./A Seedling Emergence
463618

- 01 (Supplemental) ---

Rape ( Brassica rapa ) EC 25 (dry wt) =
1.0 x 10 - 5 lb a.i./A
EC 05 ( shoot height ) =

8.0 x 10 - 7 lb a.i./A Vegetative Vigor
46578942 (Supplemental) ---

Aquatic Plants

Aquatic vascular
Plants Duckweed ( Lemna gibba ) EC 50 (dry wt) =
3.5 x 10 - 4 mg a.i./L

------- NOAEC (frond no. and dry wt) =
2.4 x 10 - 4 mg a.i./L 14

- Day Study
458329

- 01 (Supplemental) ---

Non

- Vascular Aquatic Plants Green Algae ( Selenastrum capricornutum ) EC 50 ( cell density ) =
0.05 mg a.i./L

------- NOAEC (cell density) = 0.0094 mg a.i./L 120

- Hour
421868

- 01 (Supplemental) ---

Freshwater Algae ( Anabaena flos

aquae ) EC 50 = (biomass) 0.61 mg
a.i./L

------ NOAEC (biomass and cell

density) =0.24 mg a.i./L 120

- Hour
458329

- 03 (Acceptable) ---

Algae ( Skeletonema

costatum ) EC 50 (cell density, biomass and growth rate) >126 mg
a.i./L

------ NOAEC (cell density, biomass and growth rate) = 126 mg a.i./L 120

- Hour
458329

- 02 (Acceptable) ---

Freshwater Algae ( Navicula pelliculosa ) EC 50 (cell density, biomass and growth rate) >126 mg
a.i./L

------ NOAEC (cell density, biomass and growth rate) = 126 mg a.i./L 120

- Hour
458329

- 04 (Acceptable) ---

### 93 Appendix D

. 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 chlorsulfuron ’s highest water solubility ( 3,180,000 mg/ L, pH 7 at 2 5 o 

### C , MRID 42454104 ) , the most sensitive acute and chronic avian toxicity endpoints ( Bobwhite Quail with LD 50 

### >5000 mg/kg

- bw and NOAEC = 1 74 mg/kg

- diet

, respectively) and the most sensitive acute and chronic mammalian toxicity endpoints (Rat LD 50 

### >5000 mg/kg

- bw and NOAEL = 5 mg/kg

- bw , respectively). Based on the output, exposure through drinking water alone results in potential acute and chronic risk to small birds and 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 levels and the very high water solubility , the potential for acute risk is expected to be quite conservative. Results from SIP are
shown below.

Inhalation is another potential exp osure route for terrestrial vertebrates. Based on the vapor pressure of chlorsulfuron’s physical

- chemicl properties, it is nonvolatile from dry soil and water and is predictd to be rapidly lost from moist soil. However, because it is an anion, it is expe cted that loss from moist soil may be minimal and it was not rapidly lost from moist soils in laboratory studies. T herefore

, risk from inhalation is not expected. The 4

- hr LC 50 

### inhalation study using rats was greater than 5.9 mg/L (MRID 00086825 )

. The STIR model (Screening Tool for Inhalation Risk) was used to evaluate inhalation risk to birds. The non

- definitive acute oral values for both birds and mammals were used in the model. Based on STIR, risk to birds from inhalation alone is not expecte d. Results from STIR are shown below.

### 94 SIP Version 1.0. August, 19, 2010

### 95 Results From STIR Version 1.0, November 23, 2010

### 96 Appendix E

. E xample T

- Rex Input and Output for Chlorsulfuron

.

T

- Rex can be found at: http://www.epa.gov/oppefed1/models/terrestrial/trex_usersguide.htm

Summary of Risk Quotient Calculations Based on Upper Bound Kenaga EECs

Table X. Upper Bound Kenaga, Acute Avian 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

20 36 02.15 33.31 0.01 15.27 0.00 18.74 0.01 2.08 0.00 0.46 0.00

100 4585.71 19.00 0.00 8.71 0.00 10.69 0.00 1.19 0.00 0.26 0.00

1000 6477.49 8.50 0.00 3.90 0.00 4.78 0.00 0.53 0.00 0.12 0.00

Table X. Upper Bound Kenaga, Subacute Avian Dietary Based Risk Quotients

LC50 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 29.25 ##### 13.41 ##### 16.45 #DIV/0! 1.83 #####

Size class not used for dietary risk quotients

Table X. Upper Bound Kenaga, Chronic Avian Dietary 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

174 29.25 0.17 13.41 0.08 16.45 0.09 1.83 0.01

Size class not used for dietary risk quotients

Table X. Upper Bound Kenaga, Acute Mammalian Dose

- Based Risk Quotients

Size Adjusted EECs and RQs

### 97 Class (grams) LD50

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 12088.07 27.89 0.00 12.78 0.00 15.69 0.00 1.74 0.00 0.39 0.00

35 9780.54 19.27 0.00 8.83 0.00 10.84 0.00 1.20 0.00 0.27 0.00

1000 423 0.38 4.47 0.00 2.05 0.00 2.51 0.00 0.28 0.00 0.06 0.00

Table X. Upper Bound Kenaga, Acute Mammalian 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 29.25 ##### 13.41 ##### 16.45 #DIV/0! 1.83 #####

Size class not used for dietary risk quotients

Table X. Upper Bound Kenaga, Chronic Mammalian Dietary 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

100 29.25 0.29 13.41 0.13 16.45 0.16 1.83 0.02 Size class not used for dietary risk quotients

Table X. Upper Bound Kenaga, 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 27.89 2.54 12.78 1.16 15.69 1.43 1.74 0.16 0.39 0.04

35 8.89 19.27 2.17 8.83 0.99 10.84 1.22 1.20 0.14 0.27 0.03

1000 3.8 5 4.47 1.16 2.05 0.53 2.51 0.65 0.28 0.07 0.06 0.02

### 98 A 

### ppendix F

. Example Terrplant (v. 1.2.2) Input and Output for Chlorsulfuron

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 Chlorsulfuron
PC code 118601
Use Ornamental Turf Application Method Ground

Application Form Spray Solubility in Water (ppm) 587

Table 2. Input parameters used to derive EECs.

Input Parameter Symbol Value Units
Application Rate A 0.121875 lb ai/A

Incorporation I 1 none Runoff Fraction R 0.05 none

Drift Fraction D 0.01 none

Table 3. EECs for Chlorsulfuron. Units in lb ai/A.

Description Equation EEC
Runoff to dry areas (A/I)*R 0.00609375
Runoff to semi

- aquatic areas (A/I)*R*10 0.0609375 Spray drift A*D 0.00121875

Total for dry areas ((A/I)*R)+(A*D) 0.0073125

Total for semi

- aquatic areas ((A/I)*R*10)+(A*D) 0.06215625

Table 4. Plant survival and growth data used for RQ derivation. Units are in lb ai/A.
Seedling Emergence Vegetative Vigor Plant type EC 25 NOAEC EC 25 NOAEC

Monocot 0.0003 0.000045 0.000022 0.0000026

Dicot 0.000022 0.00018 0.00001 0.0000008

Table 5. RQ values for plants in dry and semi

- aquatic areas exposed to Chlorsulfuron through runoff and/or spray drift.*
Plant Type Listed Status Dry Semi

- Aquatic Spray Drift

Monocot non

- listed 24.38 207.19 55.40
Monocot listed 162.50 1381.25 468.75

Dicot non

- listed 332.39 2825.28 121.88

Dicot listed 40.63 345.31 1523.44
*If RQ > 1.0, the LOC is exceeded, resulting in potential for risk to that plant group.

### 99 Appendix G . Reference List for OPPTS /OCSPP Fate Guidelines

The Office of Prevention, Pesticides, and Toxic Substances (OPPTS) became the Office of Chemical Safety and Pollution Prevention (OCSPP) in 2011. Some guidelines have not been updated since the name change and the titles still use OPPTS. Others have been updated and
reference OCSPP.

OPPTS or OCSPP
Guideline Citation

Hydrolysis
835.2120 (161

- 1) USEPA. 2008. Fate, Transport, and Transformation Guidelines. OPPTS 835.2120 Hydrolysis . E.
712

- C

- 08

- 012. October 2008. Office of Prevention, Pesticides, and Toxic Substances. United States Environmental Protection Agency. Available at http://www.epa.gov/ocspp/pubs/frs/publications/Test_Guidelines/series835.htm (Accessed May 5, 2012).
Aqueous Photolysis
835.2240 (161

- 2) USEPA. 2008. Fate, Transport, and Transformation Guidelines. OPPTS 835.2240 Photodegradation in Water . E. 712

- C

- 08

- 013. October 2008. Office of Prevention, Pesticides, and Toxic Substances. United States Environmental Protection Agency. Available at http://www.epa.gov/ocspp/pubs/frs/publ ications/Test_Guidelines/series835.htm (Accessed May 5, 2012).
Soil Photolysis
835.2410 (161

- 3) USEPA. 2008. Fate, Transport, and Transformation Guidelines. OPPTS 835.2410 Photodegradation in Soil . E. 712

- C

- 08

- 015. October 2008. Office of Prevention, Pesticides, and Toxic Substances. United States Environmental Protection Agency. Available at http://www.epa.gov/ocspp/pubs/frs/publications/Test_Guidelines/series835.htm (Accessed May 5, 2012).

Aerobic Soil
Metabolism
835.4100 (162

- 1) USEPA. 2008. Fate, Transport, and Transformation Guidelines. OPPTS 835.4100 Aerobic Soil Metabolism; OPPTS 835.4200 Anaerobic Soil Metabolism . EPA712

- C

- 08

- 016 & E. 712

- C

- 08

- 017. October 2008. Office of Prevention, Pesticides, and Toxic Substances. United States Envir onmental Protection Agency. Available at http://www.epa.gov/ocspp/pubs/frs/publications/Test_Guidelines/series835.htm (Accessed May 17, 2012). Anaerobic Soil
Metabolism
835.4200 (162

- 2) Aerobic Aquatic
Metabolism
835.4300 (162

- 4) USEPA. 2008. Fate, Transport, and Transformation Guidelines. OPPTS 835.4300 Aerobic Aquatic Metabolism; OPPTS 835.4400 Anaerobic Aquatic Metabolism . EPA 712

- C

- 08

- 018 & E. 712

- C

- 08

- 019. October 2008. Office of Prevention, Pesticides, and Toxic Substances. United States
Envi ronmental Protection Agency. Available at http://www.epa.gov/ocspp/pubs/frs/publications/Test_Guidelines/series835.htm (Accessed May 17, 2012). Anaerobic Aquatic
Metabolism
835.4400 (162

- 3) Sorption coefficients
835.1230 (163

- 1) USEPA. 2008. Fate, Transport, and Transformation Guidelines. OPPTS 835.1230 Adsorption/Desorption (Batch Equilibrium) . E. 712

- C

- 08

- 009. October 2008. Office or Prevention, Pesticides, and Toxic Substances. United States Environmental Protection Agency. Available at http:// www.epa.gov/ocspp/pubs/frs/publications/Test_Guidelines/series835.htm (Accessed May 5, 2012).
Leaching and Aged Column Leaching
835.1240 USEPA. 2008. Fate, Transport, and Transformation Guidelines. OPPTS 835.1240 Leaching Studies

. E. 712

- C

- 08

- 010. October 2008. Office of Prevention, Pesticides, and Toxic Substances. United States Environmental Protection Agency. Available at http://www.regulations.gov/#!documentDetail;D=EPA

- HQ

- OPPT

- 2009

- 0152

- 0007 (Accessed May 5, 2012).

### 100 OPPTS or OCSPP
Guideline Citation

Terrestrial Field Dissipati on 835.6100 USEPA. 2008. Fate, Transport, and Transformation Guidelines. OPPTS 835.1230 Adsorption/Desorption (Batch Equilibrium) . E. 712

- C

- 08

- 009. October 2008. Office or Prevention, Pesticides, and Toxic Substances. United States Environmental Protecti on Agency. Available at http://www.epa.gov/ocspp/pubs/frs/publications/Test_Guidelines/series835.htm (Accessed May 5, 2012).
Aquatic Field Dissipation
835.6200 USEPA. 2008. Fate, Transport, and Transformation Test Guidelines. OPPTS Aquatic (Sediment) Field Dissipation . EPA 712

- C

- 08

- 021. October 2008. Office of Prevention, Pesticides, and Toxic
Substances. United States Environmental Available at http://www.epa.gov/ocspp/pubs/frs/publications/Test_Guidelines/series835.htm (Accessed May 15, 2012).

Bioconcentration
Factor
850.1730 USEPA. 1996. Ecological Effects Test Guidelines. OPPTS 850.1730 Fish BCF . E. 712

- C

- 96

- 129. April 1996. Environmental Fate and Effects Division. Office of Pesticide Programs. United States Environmental Protection Agency. Available at http://www.epa.gov/opptsmnt/pubs/frs/publications/OPPTS_Harmonized/850_Ecological_Effects_T est_Guidelines/Drafts/850

- 1730.pdf (Accessed May 14, 2012).

Environmental Chemistry Method
850.6100 USEPA. 2012. Ecological Effects Test Guidelines. OCSPP 850.6100: Environmental Chemistry
Methods . E. 712

- C

- 001. January 2012. Office of Chemical Safety and Pollution Prevention. United States Environmental Protection Agency. Available at http://www.epa.gov/ocspp/pubs/frs/publications/Test_Guidelines/s eries850.htm (Accessed August 10, 2012).

### 101 Appendix H

. Identification of Transformation Products and Listing of the Maximum
A mounts Observed in Fate Studies

Table H1. Summary of maximum amount of transformation products observed in fate
studies.

Chemical Study Type MRID Maximum %AR (day) a Final %AR (study length) a

Chlorsulfuron Hydrolysis 42156701 39 (31 days), pH 5, ph 40 (31 days), pH 5, tri 99 (31 days), pH 7, ph 97 (31 days), pH 7, tri 96 (31 days), pH 9, ph 98 (31 days, pH 9, tri

Aqueous photolysis 42156702 97 (31 days) light, pH 7, ph 99 (31 days) dark, pH 7, ph 98 (31 days), light, pH 7, tri 97 (31 days), dark, pH 7, tri

Soil photolysis 41721001
42156703 75.7 (73.6 days) tri

Aerobic Soil 00035275 7.4 (180 days), 1 mg/kg, ph 6.7 (180 days, 0.1 mg/kg, ph

Anaerobic

Aquatic 42156704 54 (365 days), PA, tri 75 (70 days), PA, phe 50 (56 days), Canada, phe 82 (35 days), NE, phe 66 (28 days), IL, phe

O

desmethylchlorsulfuron (ODMC) Hydrolysis 42156701 13 (21 days), pH 5, ph 14 (21 days), pH 5, tri ND pH 7, ph 1 (31 days), pH 7, tri 1 (31 days), pH 9, ph 2 (31 days, pH 9, tri 10 (31 days), pH 5, ph 12 (31 days), pH 5, tri ND (31 days), pH 7, ph 1 (31 days), pH 7, tri 1 (31 days), pH 9, ph 2 (31 days, pH 9, tri

Aqueous photolysis 42156702 1.4 (31 days), pH 7 light, ph 0.5 (31 days), pH 7 dark, ph 0.9 (21 days), light, pH 7, tri 1.1 (31 days), dark, pH 7, tri 1.4 (31 days), pH 7 light, ph 0.5 (31 days), pH 7 dark, ph 0.9 (21 days), light, pH 7, tri 1.1 (31 days), dark, pH 7, tri

Soil photolysis 41721001
42156703 2.8 (74 days), tri 2.8 (74 days), tri

Aerobic Soil 00035275 NA NA

Anaerobic Aquatic 1 42156704 31 (365 days), PA, tri 11 (70 days), PA, phe 18 (56 days), Canada, phe

< 0.1 (35 days), NE, phe <0.1 (28 days), IL, phe 31 (365 days), PA, tri 11(70 days), PA, phe 18 (56 days), Canada, phe <0.1 (35 days), NE, phe <0.1 (28 days), IL, phe

Ring

- opened
chlorsulufuron Hydrolysis 42156701 16 (31 days), pH 5, ph 18 (31 days), pH 5, tri ND (31 days), pH 7, ph ND (31 days), pH 7, tri ND (31 days), pH 9, ph ND (31 days, pH 9, tri 16 (31 days), pH 5, ph 18 (31 days), pH 5, tri ND (31 days), pH 7, ph ND (31 days), pH 7, tri ND (31 days), pH 9, ph ND (31 days, pH 9, tri

### 102 Chemical Study Type MRID Maximum %AR (day) a Final %AR (study length) a Aqueous photolysis 42156702 NR pH 7 NR pH 7

Soil photolysis 41721001
42156703 NR NR

Aerobic Soil 00035275 NA NA

Anaerobic Aquatic 1 42156704 31 (365 days), PA, tri 11 (70 days), PA, phe 18 (56 days), Canada, phe <0.1 (35 days), NE, phe <0.1 (28 days), IL, phe 31 (365 days), PA, tri 11(70 days), PA, phe 18 (56 days), Canada, phe <0.1 (35 days), NE, phe <0.1 (28 days), IL, phe

2

- chlorobenzenesulfonami
de (CSM) Hydrolysis 42156701 33 (31 days), pH 5, ph NA (31 days), pH 5, tri 1 (31 days), pH 7, ph NA (31 days), pH 7, tri 2 (31 days), pH 9, ph NA (31 days, pH 9, tri 33 (31 days), pH 5, ph NA(31 days), pH 5, tri 1 (31 days), pH 7, ph NA (31 days), pH 7, tri 2 (31 days), pH 9, ph NA(31 days, pH 9, tri

Aqueous photolysis 42156702 1.7 (31 days), pH 7 light, ph 1.0 (21 days), pH 7 dark, ph NA, pH 7, tri 1.7(31 days), pH, 7 light, ph 0.8 (31 days), pH 7 dark, ph NA, pH 7, tri

Soil photolysis 41721001
42156703 NR NR

Aerobic Soil 00035275 NA NA

Anaerobic

Aquatic 42156704 NR (365 days), PA, tri 14 (70 days), PA, phe 11 (56 days), Canada, phe 17 (21 days), NE, phe 13 (28 days), IL, phe NR (365 days), PA, tri 14(70 days), PA, phe 11 (56 days), Canada, phe 3 (35 days), NE, phe 13 (28 days), IL, phe

Triazine Amine (TA) Hydrolysis 42156701 NA (31 days), pH 5, ph 17 (31 days), pH 5, triazine NA(31 days), pH 7, ph 1 (31 days), pH 7, triazine NA (31 days), pH 9, ph 1 (31 days, pH 9, triazine NA (31 days), pH 5, ph 17(31 days), pH 5, triazine NA (31 days), pH 7, ph 1 (31 days), pH 7, triazine NA (31 days), pH 9, ph 1 (31 days, pH 9, triazine Aqueous photolysis 42156702 NR pH 7 NR pH 7

Soil photolysis 41721001
42156703 5.5 (74 days), tri 5.5 (74 days), tri

Aerobic Soil 00035275 NA NA

Anaerobic

Aquatic 42156704 21 (365 days), PA, tri
NA (70 days), PA, phe NA (56 days), Canada, phe NA (35 days), NE, phe NA (28 days), IL, phe 21 (365 days), PA, tri NA (70 days), PA, phe NA (56 days), Canada, phe NA (35 days), NE, phe NA (28 days), IL, phe

2

- chlorosulfonylurea (CPSU) Anaerobic Aquatic 42156704 NA (365 days), PA, tri
3.1 (7 days), PA, phe
14 (56 days), Canada, phe
12 (35 days), NE, phe
9.1 (28 days), IL, phe NA(365 days), PA, tri
2.1 (70 days), PA, phe
14 (56 days), Canada, phe
12 (35 days), NE, phe
9.1 (28 days), IL, phe

### 103 Chemical Study Type MRID Maximum %AR (day) a Final %AR (study length) a

Dihydroxy Triazine (DT) Hydrolysis 42156701 NA (31 days), pH 5, ph 9 (31 days), pH 5, triazine NA (31 days), pH 7, ph ND (31 days), pH 7, triazine NA (31 days), pH 9, ph ND (31 days, pH 9, triazine NA (31 days), pH 5, ph 9 (31 days), pH 5, triazine NA (31 days), pH 7, ph ND(31 days), pH 7, triazine NA (31 days), pH 9, ph ND (31 days, pH 9, triazine

Soil photolysis 41721001
42156703 1.2 (74 days), tri 1.2 (74 days), tri

Aerobic Soil 00035275 NA NA

Anaerobic

Aquatic 42156704 NA (365 days), PA, tri NA (70 days), PA, phe NA (56 days), Canada, phe NA (35 days), NE, phe NA (28 days), IL, phe NA (365 days), PA, tri NA (70 days), PA, phe NA (56 days), Canada, phe NA (35 days), NE, phe NA (28 days), IL, phe

O

- desmethyl t riazine Amine (ODMTA)
Structure not provided Anaerobic Aquatic 42156704 <0.1 (365 days), PA, tri <0.1 (70 days), PA, phe <0.1 (56 days), Canada, phe <0.1 (35 days), NE, phe <0.1 (28 days), IL, phe <0.1 (365 days), PA, tri <0.1 (70 days), PA, phe <0.1 (56 days), Canada, phe <0.1 (35 days), NE, phe <0.1 (28 days), IL, phe

Triazine Urea (TU) Hydrolysis 42156701 NA NA

Aqueous photolysis 42156702 NR pH 7 NR pH 7

Soil photolysis 41721001
42156703 7.6 (74 days), tri 7.6 (74 days), tri

Aerobic Soil 00035275 NA NA

Anaerobic

Aquatic 42156704 NR (365 days), PA, tri NA (70 days), PA, phe NA (56 days), Canada, phe NA (35 days), NE, phe NA (28 days), IL, phe NR (365 days), PA, tri NA (70 days), PA, phe NA (56 days), Canada, phe NA (35 days), NE, phe NA (28 days), IL, phe Hydroxy Triazine Amine (OHTA) Aerobic Soil 00035275 NA NA

Anaerobic

Aquatic 42156704 NR (365 days), PA, tri NA (70 days), PA, phe NA (56 days), Canada, phe NA (35 days), NE, phe NA (28 days), IL, phe NR (365 days), PA, tri NA (70 days), PA, phe NA (56 days), Canada, phe NA (35 days), NE, phe NA (28 days), IL, phe

Hydroxy C hlorsulfuron (OHCSF) Hydrolysis 42156701 NA NA Aqueous photolysis 42156702 NA NA

Soil photolysis 41721001
42156703 NA NA

### 104 Chemical Study Type MRID Maximum %AR (day) a Final %AR (study length) a

Aerobic Soil 00035275 NA NA

Anaerobic

Aquatic 42156704 NA NA

5

- hydroxychlorosulfanami de (OHCSM)

Anaerobic Aquatic 42156704 NR (365 days), PA, tri
<0.1 (70 days), PA, phe
<0.1 (56 days), Canada, phe
<0.1 (21 days), NE, phe
<0.1 (28 days), IL, phe NR (365 days), PA, tri
<0.1 (70 days), PA, phe
<0.1 (56 days), Canada, phe
<0.1 (35 days), NE, phe
<0.1 (28 days), IL, phe

Others/ Individual
Unknowns Hydrolysis 42156701 ≤2 ≤2 (31 days) Aqueous photolysis 42156702 NR pH 7 NR pH 7

Soil photolysis 41721001
42156703 1.7 (53 days), tri 1.6 (74 days), tri

Aerobic Soil 00035275 52.9 (180 days), 0.1 mg/kg, ph 60.4 (180 days, 1.0 mg/kg, ph 52.9 (180 days), 0.1 mg/kg, ph 60.4 (180 days, 1.0 mg/kg, ph

Unextracted residues

Soil photolysis 41721001
42156703 7.2 (18 days), light, tri 8.8 (7 days), dark, tri 9.7 (77 days), light, ph 6.2 (31 days), dark, ph 3.8 (74 days), light, tri 3.5 (31 days, dark, tri 9.7 (77 days), light, ph 6.2 (31 days), dark, ph

Aerobic Soil 00035275 9 (120 days), 0.1 mg/kg, ph 7 (120 days), 1 mg/kg, ph 5 (120 days), 0.1 mg/kg, ph 5 (120 days), 1 mg/kg, ph

Anaerobic

Aquatic 42156704 4 (365 days), PA, tri 2 (28 days), PA, phe 14 (56 days), Canada, phe 14 (21 days), NE, phe 13 (28 days), IL, phe 4 (365 days), PA, tri 1 (70 days), PA, phe 14 (56 days), Canada, phe 10 (35 days), NE, phe 13 (28 days), IL, phe

CO 2 Soil photolysis 41721001
42156703 <0.9 (74 days), light, tri <0.5 (31 days), dark, tri 8.0 (31 days), light, ph <1 (31 days), dark, ph <0.9 (74 days), light, tri <0.5 (31 days), dark, tri 8.0 (31 days), light, ph <1 (31 days), dark, ph

Aerobic Soil 00035275 5 (180 days), 0.1 mg/kg, ph 5 (180 days), 1 mg/kg, ph 5 (120 days), 0.1 mg/kg, ph 5 (120 days), 1 mg/kg, ph

Total Volatiles

Soil photolysis 41721001
42156703 <2.5 (74 days), light, tri <2.1 (74 days), dark, tri
8 (31 days), light, ph <3.3 (31 days), dark, ph <2.5 (74 days), light, tri <2.1 (74 days), dark, tri 8 (31 days), light, ph <3.3 (31 days), dark, ph ND=not detected; NA=not analyzed; NR=not reported in DER; ph=phenyl ring radiolabed; tri=triazine ring
radiolabeled

1 The study reported total amount of polar compounds and indicated that the polar compounds were o

- desmethyl chlorsulfuron or ring

- opened chlorsulfuron. The total amount reported as polar compounds were reported for o

desmethyl chlorsulfuron and ring

- opene d chlorsulfuron.

### 105 Table H2. Name, SMILES Code, Molecular Weight, and Structure of Chlorsulfuron and
its Transformation Products 2

Chemical Structure
Common Name: Chlorsulfuron (CSF)
IUPAC Name: 2

- chloro

- N
1

- (2

- chlorophenylsulfonyl)

- 3

- (4

- methoxy

- 6

- methyl

1,3,5

- triazin

- 2

- yl)urea
CAS name: 2

- chloro

- N

- [[(4

- methoxy

- 6

- methyl

1,3,5

- triazin

- 2

- yl)amino]carbonyl]benzenesulfonamide
Other names: DPX

- 4189 ; IN

- W4189

SMILES: Clc1ccccc1S(=O)(=O)NC(=O)Nc2nc(nc(OC)n2)C

MW =357.77
Common Name: 5

- hydroxychlorsulfuron (OHCSF)
Other Names: 2

- chloro

- 5

- hydroxy

- N

- [(4

- methoxy

6

- methyl

- 1,3,5

- triazin

- 2

- yl)aminocarbonyl]
benzenesulfonamide ; IN

- M6957

SMILES: ClC1=C(C=C(C=C1)O)S(=O)(=O)NC(=O)NC2=N C(=NC(=N2)C)OC

MW=373.77 Log K OW =1.70 (estimated)
Common Name: O

- desmethylchlorsulfuron (ODMC)
Other Names: 2

- chloro

- N

- [[(4

- hydroxy

- 6

- methyl

1,3,5

- triazine

- 2

- yl)

- amino)carbonyl]benzenesulfanamide

SMILES: ClC1=C(C=CC=C1)S(=O)(=O)NC(=O)NC2=NC(= NC(=N2)C)O[H]

MW=343.75 Log K OW =1.20 (est imated)
Common Name: Ring

- opened chlorsulfuron (ROC)
Other Names: 1

- (2

- chlorophenylsulfonyl)

- 7

- acetyltriuret;
2

- chloro

- N

- [[[[[[(2

- oxethyl)amino]carbonyl]amino]carbonyl]

- amino]carbonyl]benzenesulfanamide ; IN

- JJ998

SMILES: C1=CC=CC(=C1Cl)S(NC(NC(NC(NCC)=O)=O)= O)(=O)=O

MW=348.76 Log K OW =2.86 (estimated)

### 106 Common Name: 2

- chlorophenylsulfonylurea (CPSU)
Other Names: 2

- chloro

- N

- (aminocarbonyl)benzenesulfanamide

SMILES: C1=CC=CC(=C1Cl)S(NON)(=O)=O

MW=222.65 Log KOW=

- 1.74 (e stimated)

Common Name: Chlorosulfonamide (CSM)
Other names: 2

- chlorobenzenesulfanamide;
INA4097

CAS#: 6961

- 82

- 6

SMILES: C1=CC=CC(=C1Cl)S(N([H])[H])(=O)=O

MW=191.63 Log K OW =0.74 (experimental)
Common Name: 5

- hydroxychlorosulfanamide (OHCSM)
Other names: 2

- chloro

- 5

- hydroxybenzenesulfanamide; INA5760

SMILES: C1=CC(=CC(=C1Cl)S(N([H])[H])(=O)=O)O

MW=207.63 Log K OW =0.53 (estimated)
Common Name: Triazine amine (TA)
Other Names: 2

- amino

- 4

- methoxy

- 6

- methyl

- 1,3,5

- triazine; INA4098 1

CAS #: 1668

- 54

- 8

S MILES: C1(=NC(=NC(=N1)C)N([H])[H])OC

MW=140.15 Log K OW =1.26 (estimated)
Common Name: Hydroxyy Triazine Amine (OH TA)
Other Names: 4

- hydroxy

- 6

- methyl

- 1,3,5

- triazine

2

- amine; IN

- B5528

CAS RN: 4719

- 11

- 3

SMILES: C1(=NC(=NC(=N1)C)N([H])[H])O

MW=126.12 Log K OW =0.21 (estimated)

### 107 Common Name: Dihydroxy Triazine (DT)
Other Names: 2,4

- dihydroxy

- 6

- methyl

- 1,3,5

- triazine

SMILES: C1(=NC(=NC(=N1)O[H])C)O[H]

MW=127.10 Log K OW =0.89 (estimated)

Common Name: Triazie Urea (TU)
Other Names: INV7160 3

SMILES: C1(=NC(=NC(=N1)OC)NC(N)=O)C

MW=183.17 Log K OW =0.89 (estimated)

O

- desmethyltriazine amine (ODMTA) This was reportedly looked for in the anaerobic aquatic metabolism study (MRID 42156704); however, a structure and formal name was not provided. From the name, it implies that it will be a structure similar to triazine amine with a missing methyl group.
Common Name: Acetylbiuret
Other Names: 1

- acetylbiuret
CAS Number: 591

- 38

- 8

SMILES: C(N)(NC(NC(C)=O)=O)=O

MW =145.12 Log K OW =

- 0.43

1 This is a transformation product for chlorsulfuron, thifensulfuron methyl, tribenuron methyl, and metsulfuron methyl.

2 Molecular weight (MW) and log KOW were obtained from EPIWEB version 4.1.

3 This is a transformation product for chlorsulfuron and thife nsulfuron

- methyl.

### 108 Appendix I . Justification of the Identified Residues of Concern

The identified transformation products in environmental fate studies include ring

- opened chlorsulfuron, o

- desmethylchlorsulfuron, 2

- chlorophenylsulfonylurea, chlorosulfonamide, triazine amine, hydroxy triazine amine, triazine urea, and dihydroxy triazine . All of these degradates are assumed to have the potential to occur in the natural environment and to have some potential for expo sure

. While hydroxychlorsulfuron, o

- desmethyl triazine amine, hydroxyl chlorosulfonamide, and a cetylbiuret are hypothesized degradation products, they were not observed in environmental fate studies; therefore, the likelihood of exposure to these degradates
is assumed to be minimal. Appendix H provides structure, identity, and fate information on the transformation products. Incomplete fate data are available and other transformation products or higher percentages of transformation products could be observ ed in fate studies submitted in the
future. Aerobic soil and aerobic aquatic metabolism studies are not available and are particularly important studies in understanding the environmental fate and transformation products that are likely to be observed in the natural environment. Toxicity data on chlorsulfuron degradation products have not been submitted to EFED; however, data are available from other sources. These data were used to prioritize the residues of concern for ecological risk assessment. As

t hese prioritizations were made based on unreviewed data, these determinations may be revisited when data are fully reviewed. It is recommended that these data be submitted to EFED to support the reregistration of chlorsulfuron and to fully support determi nations on the potential
residues of concern for chlorsulfuron.

Residues of Concern for Drinking Water Consumed by Humans

The most recent drinking water assessment completed for chlorsulfuron was in support of the TRED and was completed in 2002 ( Shanaman, 2002, D266073 ) . A Tier 1 risk assessment was completed. The only residue considered in the assessment was the parent chlorsulfuron. In 1995 the Health Effect Division (HED) Metabolism Committee Meeting (MARC) considered the
residu es of concern for residues for dietary items ( e.g ., in plants and commodities) ( Abbots,
1995a , 1995b ) . The committee determined that the residue to be regulated in plants and animal
commodities was parent chlorsulfuron only. It is anticipated that the residues of concern for human health drinking water will be revisited as new fate data that could influence the decision on the potential residues of concern for human health drinking water become available.

Sulfonylureas

O

- desmethyl chlorsulfuron, ring

- opened chlorsulfuron, and 2

- chlorophenylsulfonylureas are the transformation products that retain the sulfonylurea bridge of parent chlorsulfuron (see Figure
I1 ). O

- desmethyl chlorsulfuron was detected at maxim a of up to 31%, and was a major degradate in the hydrolysis and anaerobic aquatic metabolism study. Ring

- opened chlorsulfuron was found at a maximum of 18% in the hydrolysis study. The metabolite 2

- chlorosulfonylurea
was found at a maxim um of 12% in the anaerobic aquatic metabolism study. The o

desmethylchlorsulfuron, ring

- opened chlorsulfuron, and 2

- chlorophenylsulfonylurea are present at high enough amounts in laboratory studies that they may be assumed to be found in the natural
envir onment, and to potentially result in exposure. As o

- desmethyl chlorsulfuron , ring

- opened chlorsulfuron, and 2

- chlorophenylsulfonylurea are sulfonylurea s , they are assumed to be a

### 109 residue of concern

, and therefore a total toxic residue (TTR) approach will be used for evaluating exposure and risk for all taxa. In the absence of toxicity data on these three transformation products, their toxicit ies will be assumed to be similar to that of the parent.

Definitive and measured toxicity data for o

- desmethyl chlorsulfuron are available for green algae that suggest that o

- desmethyl chlorsulfuron is much less toxic to aquatic plants than is chlorsulfuron (chlorsulfuron algae 72

- hr EC 50 

### was 0.05 mg/L and the o

- desmethyl chlorsulfuron
72

- hr EC 50 

### for green algae wa s 26.4 mg/L). Given that the only difference in structure between
chlorsulfuron and o

- desmethyl chlorsulfuron is the presence of a methyl group in place of a hydrogen in the former, not enough data across species are available to determine that o

desmethy l chlorsulfuron is not a residue of concern for plants. Additionally, the chronic endpoints for fish suggest that the assumption of similar toxicity is appropriate for o

- desmethyl
chlorsulfuron. Chronic flow through studies are expected to only reflect ex posure to parent chlorsulfuron. Depending on the hydrolysis and aerobic aquatic metabolism half

- life, degradates may occur in chronic static studies (especially aquatic plant studies). The duration of the aquatic plant studies is 7

- days for vascular plan ts and 96

- hours for algal studies. No aerobic aquatic metabolism data are available for chlorsulfuron and it is stable to hydrolysis at pH 7 and 9. Therefore, there is not enough data to suggest that there was significant exposure to degradates in aquati c plant studies.

ECOSAR version 1.0 was also used to estimate the toxicity of transformation products ( Table
I1 ). ECOSAR is used to prioritize the need for additional data on degradates , but is not used in place of toxicity data or to calculate risk quotients . Based on ECOSAR analysis, ring

- opened chlorsulfuron was shown to be a potential residue of concern for chronic toxicity to aquatic
vertebrates and invertebrates

, as predicted chronic endpoint s were much lower than those for chlorsulfuron (20

, 00 0

– 32

, 000 μg/L for the parent and 5.6 to 94 μg/L for ring

- opened
chlorsulfuron )

. However, this prediction is based on very limited data, and given the weight of evidence is not sufficient to justify requiring additional data. Additionally, predicted acu te endpoints for ring

- opened chlorsulfuron were lower than those measured for the parent. These are discussed in more detail in the next paragraphs.

Data on the amide chemical class was used to estimate the sensitive toxicity endpoint s

. ECOSAR estimated the chronic endpoint of ring

- opened chlorsulfuron for fish and the amide
chemical class based on a single measured toxicity endpoint. The fish chronic toxicity endpoint
used for the chemical class is for 4

- nitrobenzamide and the endpoint is 1.74 mg/L. EC OSAR
used an acute to chronic ratio approach for the amide class to estimate the chronic toxicity endpoint for daphnid for ring

- opened chlorsulfuron

. Based on the limited information used to predict the chronic toxicity of this class of compounds, there i s a high level of uncertainty with this predicted endpoint. Based on the maximum amount observed of ring

- opened chlorsulfuron as a fraction of the parent was at 31% in an anaerobic aquatic metabolism study and the highest EEC previous ly reported for chlor sulfuron o f 9 .5 μg/L (9.5 x 0.31 = 3 μg/L), concentrations of ring

- opened chlorsulfuron could reach concentrations in the range of the predicted toxicity endpoints for chlorsulfuron ; however the concentrations would be much lower than the one
available end point for that chemical class. While predicted EECs may approach the predicted toxicity levels for sulfonylurea degradates, not enough information is available to support this predicted toxicity endpoint to indicate that it is likely to have a different c hronic toxicity

### 110 endpoint from the parent. Therefore, chronic toxicity data for ring

- opened chlorsulfuron are not needed to complete a risk assessment and ring

- opened chlorsulfuron will be assumed to have a similar acute and chronic toxicity to the parent unless data are available to indicate otherwise

. If data on chlorsulfuron degradates are available, EFED would encourage the registrant to submit them to EFED. Unreviewed measured chronic daphnid data data on ring

- opened chlorsulfuron
indicates that chl orsulfuron has a toxicity in the same order of magnitude of chlorsulfuron (NOAEC for chlorsulfuron=20 mg/L; NOAEC for ring

- opened chlorsulfuron is 11.7 mg/L). This supports use of the assumption of similar toxicity for the parent for the evaluation of
chr onic toxicity for ring

- opened chlorsulfuron.

The predicted acute toxicity endpoints for ring

- opened chlorsulfuron are also lower than those measured for parent chlorsulfuron. The lowest predicted endpoints were based on the imide and
amide class. The am ide regression for predicting fish 96

- hr LC 50 

### s is based on six endpoints for fish ranging from 0.3 to 290 mg/L. The amide regression for predicting daphnid 48

- hr LC 50 

### s is based on three endpoints ranging from 2 to 128 mg/L. While the regressions are base d on limited data, the measured endpoints are within the range of predicted endpoints for ring

- opened chlorsulfuron. Using a rough estimate of possible exposure for ring

- opened chlorsulfuron of 3 μg/L and the most sensitive predicted acute endpoint for ri ng

- opened chlorsulfuron (7100 μg/L), it is not likely that exposure levels could achieve concentrations where a risk concern would arise (3/7100 = 0.0004 and the corresponding lowest level of concern is 0.05). Therefore,
additional data on the acute toxic ity of ring

- opened chlorsulfuron is not recommended.
Unreviewed m easured acute toxicity data on ring

- opened chlorsulfuron and chlorsulfuron both yielded nondefinitive endpoints. It is expected that the assumption of similar toxicity for acute toxicity wi ll not significantly impact risk conclusions. If data on chlorsulfuron degradates are available, EFED would encourage the registrant to submit them to EFED.

C hlorsulfuron (CSF)

5

- hydroxychlorsulfuron (OHCSF) O

- desmethyl c hlorsulfuron (ODCSF)

### 111 2

- chlorosulufronylurea ring

- opened chlorsulfuron (ROC)

Figure I1. Structures of chlorsulfuron, O

- desmethyl chlorsulfuron, and 5

- hydroxychlorsulfuron, and 3

- chlorosulfonylurea

Table I1. Comparison of measured and estimated toxicity endpoints for chlorsulfuron and chlorsulfuron transformation products (estimated using ECOSAR version 1).* Compound Toxicity Endpoint in mg/L (measured or estimated for chemical class)

96

- hr FW fish

EC 50 /LC 50

(mg/L) 48

- hr Daphnid LC 50 (mg/L) 96

- hr EC 50 Green Algae (mg/L) Fish Chronic
Value (mg/L) Daphnid
Chronic

Value (mg/L) Sulfonylureas
Chlorsulfuron (measured) >300 (meas) 74 (triaz ) 29 (amide) 165 (NO) >370 (meas) 56 (triaz ) 18 (amide)

54 (SU) 98 (NO ) 0.05 (meas) 20 (triaz) 0.66 (amide)

0.04 (SU) 47 (NO) 32 (meas) 16 (triaz) 0.17 (amide)

-- (SU) 16 (NO) 20 (meas) 6.2 (triaz) 0.23 (amide)

5.4 (SU) 18 (NO)
ODMC
INM6957 >120 (meas) 4 196 (phenol) 1368 (triaz) 188 (amide)

-- (SU) 1247 (NO) >122 (meas) 4 51 (phenol) 471 (triaz) 81 (amide) 286 (SU)
654 (NO) 26.4 (meas) 4 252 (phenol)

83 (triaz) 1.3 (amide) 0.038 (SU) 203 (NO) -- (meas) 4 1325 (phenol)

120 (triaz) 1.1 (amide)

-- (SU) 120 (NO) 57.7 (meas) 4 9.7 (phenol)

33 (triaz) 0.57 (amide)

27 (SU) 52 (NO)
ROC
IN

- JJ998 >96 (meas) 4
22 (imide) 9.4 (amide)

-- (SU) 50 (NO) >102 (meas) 4
26 (imide) 7.1 (amide)

20 (SU) 32 (NO) >70 (meas) 4
2.6 (imide) 0.44 (amide) 0.039 (SU) -- 2.1 (imide) 0.0056 (amide)

-- (SU) 4.7 (NO) 11.7 (meas) 4
2.3 (imide) 0.094 (amide) 2.1 (SU) 3.5 (NO)
CPSU 6936 (aa) 25929 (amide)
2.5×10 5 (NO) 323 (aa) 4016 (amide) 91699 (NO) 41 (aa) 5.4 (amide) 8528 (NO) 87 (aa) 153 (amide) 25745 (NO) 8.0 (aa) 53 (amide) 4373 (NO)

Sulfonamides
CSM
INA4097 >124 (meas) 3
148 (amide) 1006 (NO) >129 (meas) 3
59 (amide) 516 (NO) >131 (meas) 3

0.79 (amide)

148 (NO) -- (meas) 0.88 (amide)

98 (NO) 39.3 (meas) 0.79 (amide)

40 (NO)

OHCSM 366 (phenol) 386 (amide) 30 (phenola) 2779 (NO) 73 (phenol) 131 (amide) 2.1 (phenola)

1344 (NO) 390 (phenol) 1.2 (amide) 12.7 (phenola)

318 (NO) 0.006 (phenol)
2.3 (amide) 1.2 (phenola)

273 (NO) 14 (phenol) 1.7 (amide) 1.2 (phenola)

96 (NO)

Triazines

TA
INA4098 > 0.93 (meas) 2
49 (aniline) 474 (triaz) >99 (meas) 2
1.9 (aniline) 171 (triaz) > 10 (meas) 4
7.7 (aniline)

31 (triaz) -- (meas)
0.21 (aniline)

44 (triaz) 97 (meas) 0.04 (aniline) 12 (triaz)

### 112 Compound Toxicity Endpoint in mg/L (measured or estimated for chemical class)

96

- hr FW fish

EC 50 /LC 50

(mg/L) 48

- hr Daphnid LC 50 (mg/L) 96

- hr EC 50 Green Algae (mg/L) Fish Chronic
Value (mg/L) Daphnid
Chronic

Value (mg/L) 454 (NO) 239 (NO) 76 (NO) 44 (NO) 19 (NO)

DT 1235 (triaz) 54 (phenolp)

858 (NO) 334 (triaz) 383 (phenolp)

433 (NO) 48 (triaz) 1.4 (phenolp)

118 (NO) 83 (triaz) 20 (phenolp)

83 (NO) 20 (triaz) 153 (phenolp) 33 (NO)

TU
INV7160 > 1 (meas) 1
336 (surea) 1746 (triaz) 177 (amide) 1219 (NO) >1.3 (meas) 1
749 (surea) 1
464 (triaz) 68 (amide) 615 (NO) >10,>11(meas) 1
0.13 (surea)

68 (triaz) 0.82 (amide)

168 (NO) -- (meas) 4.6 (surea) 119 (triaz) 1.0 (amide) 119 (NO) -- (meas)
51 (surea) 29 (triaz) 0.90 (amide)

47 (NO)
OHTA
INB5528 157 (aniline) 388 (phenol) 8264 (triaz) 24 (phenola) 3209 (NO) 2.7 (aniline) 69 (phenol) 1332 (triaz) 1.4 (phenola)

1490 (NO) 8.7 (aniline) 376 (phenol)

122 (triaz) 308 (phenola)

307 (NO) 0.77 (aniline) 0.004 (phenol)

317 (triaz) 317 (phenola)

317 (NO) 0.07 (aniline) 13 (phenol)

59 (triaz) 100 (phenola)

100 (NO)

Prometron 7.7 (meas) 5 17.7 (meas) 5,6 0.5 (meas) 5,7 3.45 (meas) 5 20 (meas) 5

Others

AB 3420 (imide) 1564 (amide) 12573 (NO) 3031 (imide) 380 (amide) 5485 (NO) 17 (imide) 1.5 (amide) 872 (NO) 343 (imide) 9.2 (amide) 1277 (NO) 174 (imide) 5.0 (amide) 330 (NO) Meas=measured; SU=sulfonylurea; NO=neutral organic; triaz=triazine; aa=aliphatic amine; phenola=phenol amine; phenolp=phenols, poly; surea=substituted ureas
* Blue values are measured values. Black values were estimated by ECOSOAR version 1.0. Purple and bold values indicate that the endpoint was much lower than that measured for the parent. Estimated toxicity endpoints

are on ly used to prioritize which degradates are likely a risk concern and how they should be handled in the risk assessment. The estimated values may over or under estimate actual toxicity of the compounds. Appendix B provides the output from ECOSAR.

1 This degradate is a thifensulufron

- methyl degradate. Data are available for rainbow trout ( Onchorychus mykiss ), daphnia

, S. capricornutum , and Lemna gibba in the EU Monograph for thifensulfuron

- methyl. These data have not been reviewed by the USEPA.

2 Data on the toxicity of triazine amine are available in the IUPAC Footprint Database ( AERU, 2012 ) . A Lemna and algae EC 50 were also reported at 10 mg/L. These data have not been reviewed by the USEPA.

3 Data on the toxicity of chlorosulfonamide are available in the footprint database. The fish acute NOAEC was reportedly 124 mg/L, daphnid acute NOAEC was 129 mg/L, Lemna 7

- day EC 50 was 26.5 mg/L, and the algae NOAEC was 131 mg/L. Data are also available on Collembola (28

- day NOAEC = 0.9 mg/L) and earthworms. These data have not been reviewed by the USEPA.

4 Data were obtained from a draft risk assessment prep ared by the European Commission ( AERU, 2012 )

. Data have not been reviewed by the EPA.

5 Data represent the most sensitive endpoint reported for prometron in the EFED Pesticide Ecotoxicity Database
searched on August 9, 2012. Only studies conducted on the technical product or with greater than 98% a.i. were
examined.

6 Endpoint reported is for the mysid ( Americamysis bahia ).

7 The marine diatom ( Phaeodactylum tricornutum ) was more sensitive than green algae for prometon and the reported endpoint was 0.23 mg/L.



### Triazines

Triazine amine, hydroxy triazine amine, triazine urea, and dihydroxy triazine are all triazines
observed in chlorsulfuron fate studies. The structures of these compounds are shown in Figure

### 113 I2

. These compounds lack the sulfonylurea bridge, and are thus likely to act by a different mode of action than parent chlorsulfuron. Toxicity data on the triazine amine and triazine urea are available from the International Union of Pure and Appl ied Chemistry (IUPAC) Footprint
Database ( AERU, 2012 ) , and from a draft chlorsulfuron risk assessment from the European
Commission ( European Commission, 2007 ) . Additionally, toxicity data on prometron (a triazine herbicide with a similar structure) were evaluated for more perspective on the potential toxicity of the triazine degradates. The lowest measured acute endpoint for the triazines was 7.7 mg/L, and the lowest chronic or plant endpoint was 0.5 μg/L. Given that the highest EEC reported for the parent was order s of magnitude lower than this at 9.5 μg/L, it is unlikely that aquatic concentrations will be sufficiently high to elicit a toxicity concern for these degradates. 15

, 16 

### This
indicates that the triazines need not be considered residues of concern for chlorsu lfuron.

Triazine Amine Hydroxyl triazine

Triazine urea Dihydroxy triazine

Prometron Figure I2. Structures of triazine amine, triazine urea, dihyrdroxy triazine, and hydroxy triazine, and prometron (a triazine herbicide with toxicity data available).

Sulfonamides

Chlorosulfonamide is a major degradate observed in laboratory studies and in lysimeter studies. The only definitive endpoint for chlorsulfonamide was 39.3 mg/L for daphnid ( Table 6 ). This value is within an order of magnitude of the daphnid chronic endpoint for the parent of 20 mg/L. ECOSAR predicted a chronic endpoint that was lower than that measured for parent

15 EEC/Toxicity endpoint = 9.5 μg/L / 77 00 μg/L = 0.001; this value is much lower than the acute LOC of 0.05.

16 EEC/Toxicity endpoint = 9.5 μg/L / 500 μg/L = 0.019;this value is much lower than the plant LOC of 1.0.

### 114 chlorsulfu ron ( Daphnids: 0.79 mg/L for chlorsulfonamide versus 20 mg/L for parent); however, EECS are not expected to approach levels that could result in a risk concern (9.5 μg/L/790 μg/L=0.01). As exposure to chlorosulfonamide is expected to be lower than to expo sure to parent chlorsulfuron, it is assumed that a risk assessment based on parent chlorsulfuron will be protective of the potential exposure due to exposure to ch l orosulfonamide. This degradate will
not be considered as residues of concern in a total tox ic residue approach because it does not
retain the sulfonylurea group.

Estimating Exposure to Total Residues

The ecological risk assessments identified ring

- opened chlorsulfuron and 2

- chlorophenylsulfonylurea as residues of concern for chlorsulfuron. Both of these residues were major residues observed in laboratory and field studies. Therefore, data on the sorp tion coefficients of these degradates are needed to permit estimat ion of concentrations of total toxic
residues in water. O

- desmethyl chlorsulfuron is expected to have mobility similar to that of the parent; therefore, data on the parent compound may be u sed to estimate soil sorption of this degradate

. EPIWEB version 1.4 predicted K OC 

### values of 124, 423, and 1 L/kg

- organic carbon for chlorsulfuron, ring opened chlorsulfuron, and 2

- chlorophenylsulfonylurea, respectively. These differences in sorption coe fficients had little impact on the estimated EEC using PRZM/EXAMs. In the absence of additional data, sorption coefficients will be estimated using
the current version of EPIWEB ( USEPA, 2009b )

.