UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON D.C., 

### 20460

PC Code: 125203 DP Barcode: D402548

MEMORANDUM

Date:

Subject:

To:

From:

Through: December 5, 2012

Registration Review

- Preliminary Problem Formulation for the Environmental Fate, Ecological Risk, Endangered Species, and Drinking Water Exposure Assessments for Clodinafop-propargyl

Wilhelmena Livingston, Chemical Review Manager Risk Management and Implementation Branch 4 Pesticide Re-evaluation Division

Attached is the preliminary problem formulation for the ecological risk assessment to be conducted as part of the Registration Review of clodinafop-propargyl.

Page 1 

### of50Page 2 of 50 

## 1. Introduction

EFED evaluated the most recent ecologi cal risk assessment and drinking water assessment for clodinafop-propargyl (PC C ode 125203) in association with the updated toxicity, exposure, and usage information to de termine if sufficient data are available and if further updates are needed to support re gistration review. The most recent ecological risk assessment is the 2000 New Chem ical assessment (DP Barcode: D244333/ D246816) for the use of clodinafop-propargyl (a lso referred to as clodinafop) on wheat. For more information on the drinking wate r assessment, please see Section 2.2. The structure of clodinafop-propar gyl and degradates of concer n can be found in Appendix D.

Clodinafop-propargyl is known as an aryloxyphenoxypropionic herbicide and is an acetyl-coenzyme A carboxylase (AC case) inhibitor and a systemic, post emergence herbicide used for post-emergent weed control of wild oats, green and yellow foxtail, and Persian darnel in wheat fi elds (including Durum). Th e herbicide inhibits the carboxylation of acetyl-CoA to malonyl-CoA that decreases fatty acid biosynthesis and prevents actively growing target weed speci es from maintaining their cell membrane integrity. The product is absorb ed through the leaves and is rapidly translocated to the growing points of leaves and stems.

The formulation (clodinafop 2-E Herbicid e, brand named HORI ZON) of clodinafoppropargyl (22.3% a.i.) and in ert ingredients (77.7%) may be applied to wheat by ground or air to control actively grow ing weeds. The wheat is protected from phytotoxic effects from clodinafop-propargyl by the presence of a safener, cloquintocet-mexyl (an inert ingredient). This particular formulated end-use product contains two pounds of active ingredient (lb a.i.) per ga llon. The maximum application rate for this use is 0.0632 pounds of active ingredient per acre (lb a.i./A) (USEPA 2000). The safener is applied in the herbicide end-use formula tion at the rate of 0.0125 – 0.0157 lb safener./A when using 3.2 or 4.0 fluid ounces of the product, respectively. Appendix A (BEAD memo) lists the use patterns of maximum exposure for th e current uses of clodinafop-propargyl.

Table 1: Screening Level Estimates of Agricu ltural Uses of Clodinafop-propargyl (125203) (January 18, 2012)
Percent Crop Treated
Crop Lbs. A.I. Avg. Max.

1 Barley + 1,000 <1 <2.5

2 Wheat 90,000 5 10

1) All numbers rounded. <500 Less than 500 pounds of active ingredient <2.5 Less than 2.5 percent of crop treated

<1 Less than 1 percent of crop treated

+ Crops not known to be listed on active end use pr oduct registrations or as Section 18 emergency exemptions for the period reported in this SLUA. 2) SLUA data sources include: USDA-NASS (Un ited States Department of Agricultu re's National Agricultural Statistics Service) Private Pesticide Market Research 3) These results reflect amalgamated data developed by the Agency and are releasable to the public.Page 3 of 50 

### A Screening Level Usage Analysis conducted by the Agency indicates that the treated fraction of crops was reported to be 5% or less on average, with a maximum of 10%. There appears to be reported uses of cl odinafop on barley, but this is not a known registered use for clodinafop. As a result, this use is deemed to be a misreported crop, or misuse, and will not be assessed in the risk assessment. The only known registered use for clodinafop is for wheat, which is classified as a terrestrial food and feed use. Please

see Table 2 below for labeled uses.

Table 2: Labeled Uses for Clodinafop-propargyl per LUIS Report (Created 6/1/2012)

Use

(Product Name, AI%, Formulation) Reg# Original (Product /

A. I.) Max App

Rate A. I. Max App Rate Max # Apps @ Max Rate

/ CC Application Method

Type Application Method Equipment Application Method Timing

WHEAT (Discover NG/ Horizon NG, 6.4% a.i., Emulsifiable Concentrate) 100-1173 16 fl oz/ A 0.0632 lb a.i. / A 1 Broadcast. Aircraft, Ground Foliar, Tillering

WHEAT (Discover Herbicide, 22.3% a.i., Emulsifiable Concentrate) 100-907 4 fl oz /A *0.0625 lb a.i./A 1 Broadcast. Aircraft, Ground Foliar, Postemergence

*Based on the label, the product contains 2 lb a.i. per gallon.



## 2. Conclusions from Previous Risk Assessments

There has only been one ecological risk assessment performed on clodinafop; a new chemical assessment (USEPA 2000). Based on the new chemical assessment, acute risks to most organisms are not expected from ground application. Minimal acute risk is expected for clodinafop-propar gyl to aquatic plants. Howeve r, it was determined that there was potential risk to federally-listed ( i.e. , listed as endangered or threatened) terrestrial plants inhabiting dry and semi-aqua tic areas from aerial application, based on observed effects in the terrestri al plant toxicity test, (corn, oats, and ryegrass) exposed to the formulated product. Data to assess chronic risk to fish and aqua tic invertebrates were incomplete, as there were no data for estuar ine/marine fish and i nvertebrates, and only chronic freshwater inverteb rate data were available for the acid CGA-193469, the primary degradate of clodinafop-propargyl. Given the available data, the new chemical assessment reported that there was minimal concern for chronic risk to freshwater organisms given that the EECs were far be low the toxicity le vels of concern.
2.1. Ecological Risk Assessments

Refer to Table 3 for the major ecological conclusions presented in the new chemical assessment. The check marks in the table refer to taxa expected to be at some level of riskPage 4 of 50 

### as a result of the use on wheat. In additi on, the check marks refer to acknowledged persistence of the chemical and potential ground water contam ination as a result of the use on wheat. The results are based on all resi dues of concern (parent and the primary degradate CGA-193469).

Table 3. Summary of Risk Concerns Identified for Clodinafop-propargyl in New Chemical Risk Assessment (DP Barcodes: D244333/ D246816)

Birds Mammals Terrestrial Plants Terrestrial Inverts Fish Aquatic Inverts Aquatic Plants Ground water Contamination Persistence Degradate of Concern

-- -- √ a

-- b

-- -- -- √ c √ d CGA193469

a The level of concern is exceeded for listed terrest rial plants when applyi ng to adjacent dry and semi-aquatic areas by air. No level of concer n is exceeded for non-listed terrestrial plants.
b Based on an oral study on honey bees, clodinafop-propargyl is practically nontoxic to bees on an acute contact basis.

c Clodinafop acid and its transformation products are highly mobile to mobile, persistent, and may reach ground water and surface water.
d Clodinafop acid and its transformation products are persistent.


### Except for terrestrial plants, risk to te rrestrial animals and aquatic plants and animals was expected to be minimal. Clodinafop-propargyl’s risk was only to terrestrial plants from aerial applicati on. Cloquintocet-mexyl, a safener used in formulation with clodinafop-propargyl, ha d a minimal risk to animals and was presumed to have minimal risk to all plants.
2.2. Drinking Water Exposure Assessments

The most recent DWA was performed Ma rch 29, 2006 (DP 324688) and drinking water EECs are included in Table 4 . In this DWA, the surface water values were modeled using PRZM EXAMS based on the North Dakot a wheat scenario, with a percent crop area factor of 0.56. Concentrations in groundw ater were estimated using the Tier 1 SCIGROW (screening) model.

Table 4: EDWCs of the Combined Toxic Residues of Clodinafop-propargyl and Three Major Degradation Products 1, 2
Surface Water
1-in-10 yr Peak μg/L (ppb). 1-in-10 yr Annual Mean μg/L (ppb). Overall Annual Mean μg/L (ppb).

3.3 2.5 1.7
Ground Water Acute Chronic
0.227 0.227

1 Degradates: (R)-2-[4-[(5-chloro-3-fluoro-2-pyridinyl) oxy]phenoxy]-propanoic acid, 5-chloro-3-fluoro-2(1H)- pyridinone, and 4-[(5-chloro-3-fluoro-2-pyridinyl)oxy]phenol
2 Simulation used one aerial application of 0.0625 lb. a.i./acre, with the concentr ation values adjusted with the percent crop area factor (PCA) of 0.56. 

### The Agency anticipates conducting an updated DWA to evaluate potential residues in groundwater, using the PRZM-GW model, whic h is replacing the SCI-GROW model.Page 5 of 50 

### SCI-GROW is an empirical model based on a linear best fit of 13 prospective groundwater studies (one year of application). SCI-GROW was designed solely for use as a Tier I screening tool and does not have the capability to consider mitigating circumstances such as variability in l eaching potential of diff erent soils, weather (including rainfall), depth to aquifer, nor does it consider multiple years of application. To address these issues, the Agency deve loped PRZM-GW model. PRZM-GW is a onedimensional, finite-difference model that estimates the concentrations of pesticides in groundwater. It accounts for pesticide fate in the crop root zone by simulating pesticide transport and degradation thr ough the soil profile after a pesticide is applied to an agricultural field. PRZM-GW permits the assessment of multiple years of pesticide application (up to 100 ye ars) on a single site.

2.3. Clean Water Act Programs

Clodinafop 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/waters10/attains_nati on_cy.control?p_report_ type=T#tmdl_by_poll
utant

. The Agency invites submission of water quality data for this pesticide. To the extent possible, data should conform to the quali ty standards in Appendix A of the OPP Standard Operating Procedur e: Inclusion of Impaired Water Body and Other Water Quality Data 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 quantit atively or qualitatively in pesticide risk
assessments.Page 6 of 50 

## 3. Environmental Fate and Transport

The major route of dissipation for clodinaf op-propargyl is de-esterification through abiotic hydrolysis and microbial mediated metabolism to form CGA-193469. Abiotic hydrolysis half-lives of clodinafop-propargyl are 18 days in pH 4 buffer solution, 26 days at pH 5, 6.1 days at pH 7, and 3.9 days at pH 9 (MRID 46012926). The major hydrolysis degradation product (>10% of applied radioactivity) was CGA-193469. Minor degradation products (<1% of applied radioactivity) in th e hydrolysis studies include CGA-193468, CGA-215010, and CGA-302371. The a queous photolysis half-life of clodinafop-propargyl ranges from 20.5 to 24.1 days in pH 5 buffer solution (MRID 46012927 and 46012928). Photodegradation products include CGA-215010, CGA193468, CGA-302371, CGA-293358, and CGA-040725, NOA-428715, and CO 2 

### . In aerobic soil and aquatic metabolism studies , clodinafop-propargyl degrades rapidly (~t1/2=<1 day) to form C GA-193469 (MRID 46012931, 46012930). The batch equilibrium data for clodinafop-propargyl represent the adsorption and desorption behavior of CGA-193469 because of the ra pid degradation of clodinafop-propargyl during equilibration (MRID 46012935) Rapid degradation of clodinafop-propargyl was confirmed in bare ground and cropped terrestr ial field dissipation st udies in North Dakota (MRID 46012939 and 46373401).

The major degradation product and suspected act ive ingredient of clodinafop-propargyl is CGA-193469. Potential routes of di ssipation for CGA-193469 are aerobic soil metabolism, leaching, and runoff. CGA-193469 had half-lives of 1 to 2.4 days in aerobic soil metabolism studies (MRI D 46012931 and 46012930). In aerobic aquatic metabolism studies, CGA-193469 had a half-life of 41 days in the total water:sediment system (MRID 44399177). In anaerobic soil and aquatic environments, CGA-193469 is moderately persistent (MRI D 44399177, 44399176, 46012932, 46012933). Because of the rapid and complete degradation of clodinafop-propargyl to form CGA-193469 in metabolism studies, the observed degradation products can be attributed to CGA-193469.Major degradation products (>10% of applied radioactivity) include CGA-193469, CGA302371, and CGA-193468. Minor degradation products (<10% of applie d radioactivity) include CGA-215010, CGA -214111, and CGA-293356. CGA-193469 is expected to be mobile (K f 

### oc = 44-89) in soil and aquatic enviro nments. Terrestrial field dissipation confirms the dissipation of CGA-193469 th rough degradation and leaching. CGA193469 had a field dissipation half-life of 7 days (MRID 46012939 and 46373401). Additionally, CGA-193469 was detected in a single replicate sample at 15-30 cm depth.

Although clodinafop-propargyl has a log Kow exceeding 3, rapid degradation of clodinafop-propargyl in soil and aquatic environments is expected to limit bioaccumulation potential. The bioconcentration factor for clodinafop-propargyl was 26- 29 X for fillet, 494-496X for visceria, and 228-2 43X for whole fish from concentrations of 0.21 and 2.1 ug/L (MRID 44719601). Degrada tion products in fish tissues were identified as CGA-193469 (maximum con centration 61-582 ug/kg in viscera) and NOA428715 (maximum concentration 23.6-299 ug/kg in viscera). Bioconcentrated residues were rapidly and completely eliminated fr om fish tissues during a 14 day depuration period.Page 7 of 50 

### Degradation Products

The degradation products identified in each fate study and their maximum concentration formed are shown in Table 5 . The environmental fate stud ies indicate the degradation products are mobile (K f 

### oc = 32-630) and more persistent th an clodinafop-propa rgyl.

Table 5: Degradation Product Formation in Environmental Fate Studie s

Degradation Product Study Maximum Percentage Formed CGA-193469 Hydrolysis 70-105% of applied (30 days) Photodegradation in Water 36.5% of applied (37 days) Aerobic Soil 79.9% of applied (2 hours) Aerobic Aquatic 97.6% of applied (1-14 days) Anaerobic Aquatic 102.3% of applied (28 days) CGA-193468 Hydrolysis 1.1% of applied Photodegradation in Water 8.06 of applied(37 days) Aerobic Soil 10.7% of applied (3 days) Anaerobic Aquatic 44.4% of applied CGA-215010 Hydrolysis 1.0% of applied Photodegradation in Water 0.57 of applied (37 days) Aerobic Soil 1.0% of applied Anaerobic Aquatic 4.9% of applied CGA-302371 Hydrolysis 1.1% of applied Aerobic Soil 22.6% of applied (14 days) Aerobic Aquatic 45.9% of applied (119 days) Anaerobic Aquatic 10.5% of applied (245 days) CGA-293358 Photodegradation in Water 2.58% of applied(37 days) CGA-040725 Photodegradation in Water 1.08% of applied (37 days) NOA-428705 Photodegradation in Water 3.76% of applied (37 days) CGA-214111 Aerobic Soil 5.6% of applied Anaerobic Aquatic 1.1% of applied



### The Health Effects Division previously iden tified the following resi dues of concern for clodinafop for the drinking water assessment:

o (R)-2-[4-[(5-chloro-3-fluoro-2-py ridinyl)oxy]phenoxy]-2-propynyl ester propanoic acid (Parent, CAS # 105512-06-9, CGA-184927)

o 2-[4-(5-chloro-3-fluoro-pyridin-2-yl oxy)-phenoxy]-propionic acid (CAS # 114420-56-3, CGA-193469)

o 5-chloro-3-fluoro-2(1H )-pyridinone (CGA-302371)

o 4-[(5-chloro-3-fluoro-2-pyrid inyl)oxy]phenol (CGA-193468)

These degradation products were considered in the most recent drinking water assessment, but for the ecological risk asse ssment the parent (CGA-184927) and the acid (CGA-193469) will be considered. Clodinafop be longs to a class of herbicides known as aryloxyphenoxypropionic herbicides. The active moiety for this class of compounds is present in the parent and the acid de gradate (CGA-193469). However, the active functional group of the compound is not seen in the degradates of the acid (CGA-302371 and CGA-193468). As a result, it is not believ ed these two degradates are as toxic as thePage 8 of 50 

### parent and the acid; therefore, only the pa rent and the primary acid (CGA193469) will be considered as part of the total toxic residues (TTR) expos ure in the ecological risk
assessment.



## 4. Receptors

Table 7 and Table 7 provide a summary of the aquatic and terrestrial taxonomic groups, respectively, and most sensitive surrogate sp ecies tested to characterize the potential acute and chronic ecological effects of cl odinafop-propargyl and its degradates (CGA302371, CGA-193469). Table 6 and Table 7 also provide a preliminary overview of the acute toxicity classifications of clodinafop-propargyl and its degradates to the tested species.

In general, all endpoints in terms of the parent clodina fop-propargyl and its primary degradate (CGA-193469) will be assessed in term s of acid equivalence (a.e.) instead of active ingredient (a.i.), give n the rapid degradation (approx imately 6 days at pH 7 for aquatic systems – hydrolysis MRID 46012926, < 0.25 hr in terrestrial systems -aerobic soil MRID 46012930) of the parent to CGA-193469 (DP 215199). The conversion is based on a ratio of molecular weights, not unl ike the fate and toxicity bridging strategy utilized in a 2,4-D risk assessm ent completed in 2009 (US EPA, http://www.epa.gov/oppfead1/endanger/litstatus/effects/redleg-fr og/2-4-d/analysis.pdf ).

None of the available data (although limited) i ndicate that any of the degradates are more toxic than the parent com pound. Therefore, the assumption of equivalent or lesser toxicity of the degradate relative to the parent was made on the basis that the residues of concern are of equal or le sser toxicity than that of the parent compound.

4.1. Effects to Aquatic Organisms

Acute toxicity classifications indicate that the parent compound is highly toxic to freshwater fish and at most sl ightly to moderately toxic to freshwater invertebrates. The degradate CGA-193469 is at most moderately toxi c to freshwater invertebrates. Available data (acute and chronic data on the freshwat er invertebrate) on the parent, clodinafoppropargyl and the primary degradate, CGA-1934 69, suggest that the relative toxicity is uncertain because the data on the parent is e ither based on a non-defi nitive value (acute) or is not available ( i.e., classified as invalid, chronic) . A comparison of non-vascular aquatic plant data suggest s that the green algae ( S. subspicatus ) is less sensitive to the degradate CGA-302371 than it is to the pa rent compound; however, there are no data available on the primary degradate, CGA-193469. No chronic data are available for the freshwater fish and freshwater invertebrates on the parent.Page 9 of 50 Table 6. Summary of the Most Sensitive Endpoints from Available Aquatic Toxicity Studies for Clodinafop-propargyl and its Degradates (CGA-193469, CGA-302371)

Taxonomic

Group Study Type % a.i. Surrogate Species Toxicity Value MRID and Classification Acute Toxicity Classification

Freshwater fish 1 Acute 93.7 Bluegill sunfish ( Lepomis macrochirus ) LC 50 : 0.24 mg total/L 44399113 Supplemental 2 Highly toxic

99(CGA302371) Rainbow trout ( Oncorhynchus mykiss ) LC 50 >95.4 mg a.i./L 44399108 Supplemental 3 Practically non-toxic

Chronic (EarlyLifeStage) No Data --- --- -- --

Freshwater invertebrates Acute 94.7

Waterflea ( Daphnia
magna ) LC 50 : >2.0 mg a.i./L 44561102 Supplemental 4 Moderately toxic
86.4(CGA193469) LC 50 : >9.2 mg a.i./L 44399116 Supplemental 4 Moderately toxic

99(CGA302371) LC 50 : >98.9 mg a.i./L 44399117 Supplemental 4 Practically non-toxic

Chronic 99.3(CGA193469) NOAEC: 2.6 mg a.i./L LOAEC: 10.3 mg

a.i./L 44399121 Supplemental 4 Not applicable

Estuarine/ marine fish Acute No Data --- --- -- --

Estuarine/ marine invertebrates Acute No Data --- --- -- --

Aquatic plants and algae Vascular 94.2 Duckweed ( Lemna gibba ) EC 50 : >2.4 mg a.i./L 44399165 Acceptable Moderately toxic (at

most)

Nonvascular 94.2 Freshwater diatom ( Navicula pelliculosa ) EC 50 : 3.0 mg a.i./L 44399166 Acceptable Moderately toxic

99(CGA302371) Green Algae ( Scenedesmus subspicatus ) EC 50 : 30.6 mg a.i./L 44399161 Supplemental 5 Slightly toxic

1 Freshwater fish may be surrogate s for aquatic-phase amphibians.
2 A definite chemical analysis was not determined by centrifuging the test material
3 Only 7 fish were used per concentration
4 pH and water hardness exceeded the recommended range of the EPA guidelines
5 Study terminated at 72-hr instead of 96-hrPage 10 of 50 

### 4.2. Effects to Te rrestrial Organisms

Acute toxicity classifications indicate that the parent compou nd is slightly toxic to birds on an oral basis and practically non-toxic to bi rds on a dietary basis. Similarly, the parent compound is classified as practically non-toxi c to honeybees on an acute contact basis. Uncertainty in the available data stems from the following: 1) an acute oral passerine study is not available; 2) no t oxicity data are available for degradates (except for the terrestrial plant tier II studies on CGA-193469) . No open literature toxicity data were submitted or identified; however, a couple of terrestrial plant studies were completed in 2002 and reviewed by EFED in 2004, in response to requested data identified in the 2000 new chemical assessment. The data request was for a seedling emergence study and a vegetative vigor study using the acid degradate without a safe ner. Indeed, the tier II studies were conducted with 100% CGA- 193469; seedling emergence (MRID 46012902) and vegetative vigor (MRID 46012901). A comp arison of terrestrial plant data (TEP versus degradate CGA-193469) is also inconc lusive. Firstly, the dicots were deemed insensitive to the test compounds in all terrestrial plant st udies (seedling emergence and vegetative vigor). With regard to monocots, heightened sensitivity (in ryegrass) to the degradate than to the TEP is observed in the seedling emergence studies, but reduced sensitivity (in corn) to the degradate relativ e to the TEP is observed in the vegetative vigor studies.

Table 7. Summary of the Most Sensitive E ndpoints from Terrestrial Toxicity Studies for Clodinafop-propargyl and its Degradate CGA-193469 Taxonomic

Group Study Type % a.i. Surrogate Species Toxicity Value MRID and Classification Acute Toxicity Classification

Birds 1 Acute oral 93.7 Northern bobwhite quail ( Colinus virginianus ) LD 50 : 1455 mg a.i./kg 44399106 Acceptable Slightly toxic

Sub-acute dietary 93.7 Northern bobwhite quail LC 50 : >5120 2 mg a.i./kg 44399110 Acceptable Practically nontoxic

Chronic 94.2 Northern bobwhite quail NOAEC & LOAEC: > 500 mg a.i./kg (no significant reduction at the highest concentration tested) 44399112 Acceptable Not applicable

Mammals Acute Oral 93.7 Laboratory rat ( Rattus norvegicus ) LD 50 : 1392 mg a.i./kg (male) 44399124 Slightly toxicPage 11 of 50 Taxonomic

Group Study Type % a.i. Surrogate Species Toxicity Value MRID and Classification Acute Toxicity Classification

Acute Inhalation 93.7 Laboratory rat ( Rattus norvegicus ) LC 50 : 2325 mg/m 3 (2.3 mg/L) 44399126 (4-hr exposure) --

Chronic (2- gen) 93.7 Lab rat NOAEC: 50 mg a.i./kg LOAEC: 500 3 mg a.i./kg 44399146 Not applicable

Insects Acute contact 93.7 Honey bee ( Apis mellifera ) LD 50 : >100
 g a.i./bee 44399167 Acceptable Practically nontoxic

Terrestrial plants Seedling Emergence (Tier II) TEP 4 Monocot – Ryegrass EC 25 : 0.031 lbs a.i./A NOAEC: 0.023 lbs a.i./A Endpoint: shoot weight 44555002 Acceptable Not applicable

Dicot 5

- None EC 25 : >0.091 lbs a.i./A NOAEC: 0.091 lbs a.i./A

CGA193469 (Deg.) Monocot – Ryegrass EC 25 : 0.017 lbs a.i./A NOAEC: 0.00788 lbs a.i./A Endpoint: dry weight 46012902 Acceptable Not applicable

Dicot 6

– None EC 25 : >0.063 lbs a.i./A NOAEC: 0.063 lbs a.i./A

Vegetative vigor (Tier II) TEP 4 Monocot - Corn EC 25 : 0.0048 lbs a.i./A NOAEC: 0.0028 lbs a.i./A Endpoint: phytotoxicity 44555002 Acceptable Not applicable

Dicot 7

- None EC 25 : >0.091 lbs a.i./A NOAEC: 0.091 lbs a.i./APage 12 of 50 Taxonomic

Group Study Type % a.i. Surrogate Species Toxicity Value MRID and Classification Acute Toxicity Classification

CGA193469 (Deg.) Monocot - Corn EC 25 : 0.031 lbs a.i./A NOAEC: 0.0158 lbs a.i./A Endpoint: dry weight 46012901 Acceptable Not applicable

Dicot 8

- None EC 25 : >0.063 lbs a.i./A NOAEC: 0.063 lbs a.i./A

1 Birds represent surrogates for terrest rial-phase amphibians and reptiles.
2 One bird perished at 325 mg a.i./kg on day 1
3 Parent: based on decrease in body we ight gain, reduced food consumption, in creased liver and kidney weights and histopathological changes in the liver
4 CGA-184927 (22.3% a.i.); CGA-185072 (5.79% a.i.)
5 Dicots tested include cabbage, lettuce, tomato, soybean, carrot, cucumber
6 Dicots tested include carrot, cucumber, lettuce, radish, soybean, tomato
7 Dicots tested include cabbage, lettuce, radish, soybean, carrot, cucumber
8 Dicots tested include carrot, cucumber, lettuce, radish, soybean, tomatoPage 13 of 50 

### 4.3. Ecological Incidents

Preliminary reviews of the Ecological Incide nt Information System (EIIS, version 2.1) and the Avian Incident Monitoring System (AIMS) 1 

### were conducted on August 22, 2012. A total of 2 EIIS incidents associated with clodinafop-propargyl use were located. In addition to the incidents recorded in EIIS and AIMS, additional incidents have been reported to the Agency in aggregated inci dent reports, within the US EPA Office of Pesticide Programs Incident Data System. Pes ticide registrants report certain types of incidents to the Agency as aggregate c ounts of incidents occu rring per product per quarter. However, for clodinafop-propargyl no a ggregate incident repor ts were available.

2 EIIS Incident reports: Plants Incident ID: I014266-002 The ‘possible’ spray (drift) from unspecified misuse of clodinafop-propargyl led to this terrestrial plant incident (possibly strawb erries) in the summer of 2003 in Manitoba, Canada.

Incident ID: I016904-001 The ‘probable’ accidental ground spray (direct treatment) from accidental exposure or misuse of clodinafop-propargyl le d to this terrestrial plant in cident (150 acres of corn) in the summer of 2005 in North Dakota.



## 5. Conceptual Model

The parent, clodinafop, rapidly de grades to the acid equivalent , and the acid degrades to form the remaining residues of concern. The conceptual model will consider the acid (CGA-193469), as well as remaining parent co mpound if any, to determine a total toxic residue (TTR) approach (see Section 6: Analysis Plan for how that will be done). The environmental fate properties of TTR indicate that direct spray, sp ray drift, leaching to ground water, surface water exposure, and runoff represent potential transport mechanisms of clodinafop to aquatic and terrestrial organisms. Clodinafop acid and its transformation products are high ly mobile to mobile, persistent, and may reach ground water and surface water.

Additional Terrestrial Exposure Pathways

Inhalation Exposure The S creening T ool for I nhalation R isk (STIR v.1.0, November 19, 2010) was used to calculate an upper bound esti mate of exposure using cl odinafop-propargyl’s vapor pressure (2.39 x 10 -8 

### mm Hg at 25 o 

### C) and molecular weight (349.74 g/mol) for vapor phase exposure as well as the maximum appli cation rate (0.0632 lb a.i./A, which is the maximum single as well as seasonal applicatio n rate to wheat) and method of application (ground spray applications ; note: altering the met hod of application to aerial spray did not

1 http://www.abcbirds.org/abcprograms/ policy/pesticides/aims/aims/index.cfmPage 14 of 50 

### change the conclusions) for spray drift. STIR incorporates results from several toxicity studies including acute oral a nd inhalation rat toxi city endpoints obtained from the “sixpack” of core studies, which are a series of six guideline studies that are submitted to the Registration Division of the Office of Pestic ide Programs on laboratory rats for technical and formulated products of a pestic ide (male rat acute oral (TGAI): LD 50 

### = 1392 mg a.i./kg-bw, MRID 44399124; rat inhalation (TGAI): 4-hour LC 50 

### = 2.3 mg/L, MRID 44399126). In addition, the most sensitive acute oral avian toxicity endpoint (Northern bobwhite quail, LD 50 

### = 1455 mg a.i./kg-bw, MRID 44399106) was used. Based on the results of the STIR model, inhalation exposur e alone was not determined to be a potential pathway of concern for avian or mammalian sp ecies on an acute basis as a result of ground or aerial spray applications of clodinafop-propargyl on wheat. For raw input/output, see Appendix C

. Inhalation exposure via spray dr ift and/or vapor-phase of the pesticide alone does not appear to be of concern. The analysis of the inhalation route in STIR does not consider that aggregation with other e xposure pathways such as dietar y, dermal, or drinking water may contribute to a total exposure that has a po tential for effects to non-target animals. However, the Agency does consider the relativ e importance of other routes of exposure in situations where data indicate that pestic ide exposures through other routes may be potentially significant contribu tors to wildlife risk (USEPA , 2004). Detailed information about STIR v.1.0, as well as the tool, can be found on the EPA’s website at: http://www.epa.gov/pesticides/science/models_pg.htm#terrestrial

. Drinking Water Exposure Drinking water for the purposes of terrestrial organism risk assessment is defined as that portion of an organism’s daily water intake that is not met by dietary or metabolic sources and must be consumed in liquid form. Typical drinking water sources for wildlife in pesticide use areas may include on-field puddles, irrigation equipment (e.g., drip irrigation in grape cultivation), dew depos ited on treated plants, and off-field surface water exposures.

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 clodinafop- propargyl’s solubility in water (4 mg/L at 25 o 

### C). Using TGAI clodinafop-proparg yl data for the most sensitive acute (LD 50 

### = 1455 mg a.i./kg-bw for the Northern bobwhite quail, MRID 44399106) and chronic (NOAEC > 500 mg a.i./kg-diet, Northern bobwhite quail, MRID 44399112) avian toxicity endpoints and the most sensitive acute (LD 50 

### = 1392 mg a.i./kg-bw, male rat, MRID 44399124) and ch ronic (reproduction NOAEC = 50 mg/kg-diet, which was converted to 2.5 mg/kg-bw/day based on a r ecalculation in T-REX using standard FDA lab rat conversion, MRID 44399146) mammalian toxicity endpoints. Drinking water exposure alone was determined not to be a potential pathway of concern for avian and mammalian species on an acute and chroni c basis. For raw input/output, see Appendix C . Detailed information about the SIP v.1.0, as well as the tool, can be found on the EPA’s website at http://www.epa.gov/pesticides/s cience/models_pg.htm#terrestrial . For raw input/output, see Appendix C

.Page 15 of 50 

## 6. Analysis Plan

The total toxic residues approach will be used for the clodinafop assessment when determining the Environmental fate data parameters for modeling using the Guidance for Selecting Input Parameters in Modeling the Environmental Fate and Transport of Pesticides , Version 2.1, October 22, 2009 and the dr aft Guidance for Modeling Pesticides Total Toxic Residues (TTR) May 20, 2009. Using this total t oxic residue approach assumes the residues of concern are of e qual toxicity to the parent compound.

The TTR approach will be used to determ ine the input parameters for aquatic and terrestrial exposure. Given the limited toxicity data to reliably compare the relative toxicity between the parent and its pr imary degradate (the acid CGA-193469), the assumption of equivalent or lesser toxicity of the degradate relative to the parent was made on the basis of the avai lable acute and chronic data.

Likewise, for both aquatic and terrestrial expos ure, an acid equivale nce to the degradate (CGA-194369) will be calculated. The acid equi valence calculation is a conversion from active ingredient to acid equi valent using the relationship between the molecular weight of the parent and its primary degradate (t he acid CGA-193469) in order to normalize the toxicity data to the same concentrat ion units. A memo written in 2006 (DP 215199) stated that since “the reported environmen tal fate half-lives of clodinafop... [without TTR]...are very short, EFED believes th at the major degradate (CGA-194369), may actually be the active ingredient.” Given the rapid degradation of th e parent to the acid (approximately 6 days at pH 7 for a quatic systems – hydrolysis MRID 46012926, <0.25 hrs in terrestrial systems -aerobic soil MRID 46012930).

Therefore, all inputs for modeling, in addi tion to performing TTR, will be converted to the acid equivalence for the degradate CGA-1943 69. In general, all toxicity endpoints in terms of the parent clodinafop-propargyl and CGA-193469 will be reported in terms of acid equivalence (a.e.) instead of active ingr edient (a.i.), given the rapid degradation (approximately 6 days at pH 7 for a quatic systems – hydrolysis MRID 46012926, <0.25 hrs in terrestrial systems -aerobic soil MRID 46012930) of the parent to CGA-193469 (DP 215199).

A selection of environmental fate and transp ort properties of clodina fop and degradate of concern are summarized in Table 8 . For chemical structures see Appendix D. A detailed list of all studies and acceptability status can be found in Section 7.

Table 8: Chemical Properties and Environm ental Fate Parameters of Clodinafop and Degradate of Concern

Parameter Value Source Selected Physical/Chemical Parameters
Molecular Weight (Parent) 349.74 Sigma-Aldrich Co.
Vapor pressure 2.39 x 10 -8 mmHg at 25  C (parent) 44399101Page 16 of 50 Parameter Value Source

Aqueous solubility 4.0 mg/L at pH 7, 25  C (parent) 44399101

Henry’s Law Constant (20°C) 2.75 x 10 - 9 atm x m3/mole calculated

Persistence Hydrolysis half-life (25  C) TTR: stable (total toxic residues) 46012926

Aqueous photolysis half-life (25  C) 52 da y s (total toxic residues, study submitted under 46012928) 46012927, 46012928

Aerobic soil metabolism half-life (25°C) Total toxic residues: 96.6 and 67.9 days 46012930, 46012931, 44399177
Anaerobic aquatic metabolism half-life (20- 29  C) stable (total toxic residues**) 46012933, 46012933
Aerobic aquatic metabolism half-life [dissipation half-life A ] (25  C) CGA-193469 half-life = 41 days in the total water:sediment system MRID 44399177

Mobility

K oc 285 (average of all Koc values from TTRs[55,89,43,32,46,58,52,70,50,81,62,72,6 1,98,32,71,87,96,76,832,2133,647,998,718,5 77]) 46012935, 46012934, 46012937, 46012936

* while the half-life only includes only two of the three degradates of concern, most of the uncertainty associated with using this value is captured by calculating the 90% upper bound on the mean ** t 1⁄2 = 965 days calculated


### Since the parent degrades rapidly to the aci d and the acid is an i onic compound that is, by nature, not expected to bioaccumulate, it is not necessary to run KABAM because accumulation in fish tissues is not expected.Page 17 of 50 

### 6.1. Stressors of Concern

The stressors of concern for aquatic and te rrestrial organisms are the parent compound and the acid degradate (CGA- 193469). It is believed th at the degrad ates CGA-193468 and CGA-302371, which are degradates formed from the acid, are less toxic than the parent and the acid. Clodinafop belongs to a class of herbicides known as aryloxyphenoxypropionic herbicides. The active moiety for this class of compounds is present in the parent and the acid de gradate (CGA-193469). However, the active functional group of the compound is not seen in the degradates of the acid (CGA-302371 and CGA-193468). As a result, it is not believ ed these two degradates are as toxic as the parent and the acid.

The clodinafop residues of concern may be r eevaluated pending receipt and review of additional environmental fate and toxicity data . Safeners are currently not included in the
assessment.

6.2. 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

. Screening level calculations have suggested that drinking water and inhalation exposure pathways for wildlife are likely not of concern (Appendix C).

In addition to the routes of exposure descri bed above, irrigation wa ter exposure/analysis may be conducted as clodinafop residues/degr adates are persistent and mobile and may contaminate irrigation water.

6.3. Measures of Effect

Toxicity data presented in Section 3 of this problem formulation will be used to calculate risk quotients. In general, all endpoints in terms of the parent cl odinafop-propargyl and CGA-193469 will be reported in terms of acid equivalence (a.e.) instead of active ingredient (a.i.), given the ra pid degradation (approximately 6 days at pH 7 for aquatic systems – hydrolysis MRID 46012926, <0.25 hrs in terrestrial systems -aerobic soil MRID 46012930) of the parent to CGA-193469 (DP 215199). Any additional information submitted by the registrant or f ound in the open literature prior to conduct of the risk assessment will also be considered. The open literature studies are identified using EPA’s ECOTOXicology data base (ECOTOX) (USEPA, 2007 c ), which employs a literature search engine for locating chemical toxicity data for aquatic life, terrestrial plants, and wildlife.Page 18 of 50 

### 6.4. Endangered Species Assessments

Consistent with the Agency’s responsibility under the Endangered Species Act (ESA), the Agency will evaluate risks to federally li sted threatened and/or endangered (listed) species from registered uses of pesticides in registration review. These assessments will be conducted in accordance with standard EPA procedures and good scientific judgment.

6.5. Endocrine Disrupt or Screening Program

As required by FIFRA and FFDCA, EPA review s numerous studies to assess potential adverse outcomes from exposure to chemicals. Collectively, these studies include acute, subchronic and chronic toxici ty, including assessments of carcinogenicity, neurotoxicity, developmental, reproductive, and general or systemic toxicity. These studies include endpoints which may be susceptible to e ndocrine influence, including effects on endocrine target organ histopathology, organ weights, estrus cyclicity, sexual maturation, fertility, pregnancy rates, re productive loss, and sex ratios in offspring. For ecological hazard assessments, EPA evaluates acute test s and chronic studies that assess growth, developmental and reproductive effects in di fferent taxonomic groups. As part of the registration review decision

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

EPA has developed the EDSP to determine whether certain substances (including pesticide active and other ingred ients) may have an effect in humans or wildlife similar to an effect produced by a “natur ally occurring estrogen, or othe r such endocrine effects as the Administrator may designate.” The ED SP employs a two-tiered approach to making the statutorily required determinations. Tier 1 consists of a battery of 11 screening assays to identify the potential of a chemical substa nce 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 inte ract with E, A, or T hormonal systems will proceed to the next stage of the EDSP wher e EPA will determine which, if any, of the Tier 2 tests are necessary based on the avai lable data. Tier 2 te sting is designed to identify any adverse endocrine-related eff ects 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 first group of 67 chemicals, which contains 58 pesticide active ingredient s and 9 inert ingredients. Clodinafop-propargyl is not among the group of 58 pesticid e active ingredients on the initial list to be screened unde r the EDSP. Accordingly, as part of registration review, EPA will issue future EDSP orders/data call-ins, requiring the submission of EDSP screening assays for clodinafop-propargyl. For further information on the status of the EDSP, the policies and procedures, the list of 67 chemicals, future lists, the testPage 19 of 50 

### guidelines and the Tier 1 screening battery, please visit our website: http://www.epa.gov/endo/

.



## 7. Preliminary Identification of Data Gaps

7.1. Environmental Fate

Table 9 identifies environmental fate studies, as well as study classifications, and whether or not further data are needed in order to support risk assessment.

Table 9. Submitted Environmental Fate Data for Clodinafop

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

835.2120 Hydrolysis 44399169 Unacceptable (no)

-- 46012926 Acceptable

835.2240 44399170 Unacceptable (no) Aqueous photolysis -- 46012927 Acceptable 46012928 Acceptable
835.2410 Soil photolysis 44399171 Acceptable (no)

--

835.4100 Aerobic soil metabolism 44399174 Supplemental

(no) -- 44399172 Supplemental 44399173 Supplemental 44399176 Supplemental 46012931 Acceptable 46012931 Acceptable

835.4200 Anaerobic soil metabolism 44399176 Supplemental (no) A new anaerobic soil metabolism

study is not expected to provide useful information for this risk
assessment.

835.4300 Aerobic aquatic metabolism 44387449 Supplemental (no)

-- 44399177 Supplemental 44399178 Supplemental

835.4400 Anaerobic aquatic metabolism 46012933 Acceptable

(no) -- 44387448 Supplemental

4399176 SupplementalPage 20 of 50 OCSPP Guideline Data Requirement Submitted Studies (MRID) Study Classifications Are data needed to conduct risk assessment? Current Additional Data Need

46012932 Acceptable 4399177 Supplemental

835.1230/835.1240 Adsorption/ desorption and leaching 46012937 Acceptable (CGA-193469)

(no) -- 44831201 Supplemental (CGA-193469)

44831202 Supplemental (CGA-302371)

46012935 Supplemental

46012936 Supplemental

44399179 Unacceptable
44399180 Unacceptable

46012934 Supplemental

44399182 Supplemental

44399181 Unacceptable

835.1410 Volatility – laboratory Not required

835.6100 Terrestrial field dissipation 46012939/ 46373401 Supplementalfor CGA193469 (no)

--

Analytical method in soil 46012938 Acceptable

835.6200 Aquatic field dissipation

Not required Analytical method in waterPage 21 of 50 OCSPP Guideline Data Requirement Submitted Studies (MRID) Study Classifications Are data needed to conduct risk assessment? Current Additional Data Need

850.1730 Fish bioconcentration 44719601/ 44719602 Supplemental (no) --



### 7.2 Ecological Effects

Table

, Table and 12 identify ecological eff ects studies as well as study classifications and whether or not further data are needed in order to support risk assessment. Rationales for the additional data requested are presented in the preliminary identification of data gaps section.

Toxicity data for the parent compound are available for birds, mammals, terrestrial invertebrates, terrestrial plan ts, vascular and non-vascular aq uatic plants, freshwater fish and freshwater invertebrates. For de gradates CGA-302371 and CGA-193469, acute and chronic toxicity data are availa ble for freshwater fish and invertebrates as well as a green algae study. Data gaps are identified a nd summarized in subsequent tables.

Currently, there are no data are available for es tuarine/marine fish or invertebrates on an acute or chronic basis. To determine if data are needed, EPA conducted a cursory analysis to estimate how much more sensitive estuarine/marine animals would need to be in order to exceed the level of concern. In the case for fish, based on the peak surface water estimated environmental concentrati on (EEC) of 2.5 ppb, in order to exceed the listed acute LOC of 0.05 for fish and considering the LC 50 

### of 0.24 ppm for freshwater fish (bluegill sunfish, MRID 44399113), the marine/estuarine endpoint would need to be over 1,900 times more sensitive in order to exceed the LOC. For acute exposure to invertebrates, even when assuming that the lowest reported endpoi nt of >2.0 ppm as a definitive value, the marine/estuarine i nvertebrate endpoint would need to be approximately 16,000 times more sensitive in orde r to exceed the LOC. Therefore, at this time, EFED does not recommend re questing toxicity data to evaluate potential toxicity to estuarine/marine animals at this time, and intends to use the available freshwater animal data as a surrogate to assess potentia l risk to all aquatic animals.Page 22 of 50 

### Table 10. Submitted Aquatic Ecological Ef fects Data for Clodinafop-propargyl

OCSPP Guideline Data Requirement Submitted Studies (MRID) Study Classifications

(%purity) Are data needed to conduct

risk assessment? Comments

850.1010 Freshwater invertebrate acute toxicity 44399115 Supplemental (TGAI, 93.7%) No A definitive endpoint was not determined. There is unexplained variability across studies in the freshwater invertebrate data and no clear explanation as to presence of mortality at lower concentrations. 44561102 Supplemental (TGAI, 94.7%)

850.1025 850.1035 850.1045 850.1055 Saltwater invertebrate acute toxicity None N/A No --

850.1075 Freshwater fish acute toxicity 44561101 Acceptable (TGAI, 94.7%) No --

44399114 Supplemental (TGAI, 93.7%) A definitive chemical analysis was not determined by centrifuging the test material. 44399113 Supplemental (TGAI, 93.7%)

850.1075 Saltwater fish acute toxicity None N/A No --

850.1300 Freshwater invertebrate life cycle 44399119 Invalid No A definite LOAEC could not be produced because test concentrations were only measured for 3 days instead of 21 days

44399120 Invalid Test solutions contained precipitate but were not centrifuged before chemical analysis; the LOAEC was at the lowest test level, therefore the NOAEC could not be produced.

850.1350 Saltwater invertebrates life cycle None N/A No --

850.1400 Freshwater fish early-life stage None N/A Yes Study is recommended preferably on a species already tested in an acute study. Non-GLN Long-term lethality toxicity 44399118 Supplemental (TGAI, 93.7%) No Rainbow trout 21-day toxicity study.Page 23 of 50 OCSPP Guideline Data Requirement Submitted Studies (MRID) Study Classifications

(%purity) Are data needed to conduct

risk assessment? Comments

850.1400 Saltwater fish early-life stage None N/A No --

850.1500 Fish life cycle None N/A No -- 850.4400 Aquatic plant growth: Tier II vascular plants 44399165 Acceptable No --

850.5400 Aquatic Plant Growth:Tier II nonvascular plants 44399162 Acceptable (TGAI, 94.2%) No --

44399163 Supplemental (TGAI, 94.2%) Study terminated at 72-h instead of 96-h. 44561104 Acceptable (TGAI, 94.7%) --

44399166 Acceptable (TGAI, 94.2%) --

44399164 Supplemental (TGAI, 94.2%) Initial numbers of cells exceeded the recommended range of 3,000-10,000 cells. 44561103 Acceptable (TGAI, 94.7%) --



### Table 11. Submitted Terrestrial Ecological Effects Data for Clodinafop-propargyl

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

850.2100 Avian oral toxicity 44399106 Acceptable (TGAI, 93.7%) Yes Data is available for Northern bobwhite quail and mallard duck, but it is not available for a passerine species, which is required under 40 CFR Part 158. 44399107 Acceptable (TGAI, 93.7%)

850.2200 Avian dietary toxicity 44399110 Acceptable (TGAI, 93.7%) No --

44399109 Acceptable (TGAI, 93.7%)

850.2300 Avian reproduction 44399112 Acceptable (TGAI, 94.2%) No --Page 24 of 50 OCSPP Guideline Data Requirement Submitted Studies (MRID) Study Classifications Are data needed for risk assessment? Comments

44399111 Invalid Total number of eggs laid and eggs laid per hen are significantly lower in the control group; thus, the power of the test is insufficient to determine a statistically significant endpoint. 850.3020 Honey bee
acute contact toxicity 44399167 Acceptable (TGAI, 93.7%) No --

850.3030 Honey bee residue on foliage None N/A No --

850.3040 Field testing for pollinators None N/A No --

850.4100 Terrestrial plant toxicity: Tier II seedling
emergence 44555002 Acceptable (TEP, 2 a.i.) No CGA-184927 (22.3%); CGA-185072 (5.79%)
46012902 Acceptable (TGAI, deg) 1 CGA-193469 (100%)

850.4150 Terrestrial plant toxicity: Tier II vegetative vigor 44555002 Acceptable (TEP, 2 a.i.) No CGA-184927 (22.3%); CGA-185072 (5.79%)
46012901 Acceptable (TGAI, deg) 1 CGA-193469 (100%)

1 These terrestrial plant studies were completed in 200 2 and reviewed by EFED in 2004, which address the data request of the 2000 new chemical assessment. The data request was for a seedling emergence and a vegetative vigor study using a degradate without a sa fener. The prior data gap has been fulfilled.Page 25 of 50 

### Table 12. Aquatic Ecological Effects Data for Clodinafop-propargyl Degradates, CGA-302371 and CGA-193469

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

850.1010 Freshwater invertebrate acute toxicity 44399116 Supplemental (TGAI, deg, 86.4%) No A definitive endpoint was not determined. Test compound: degradate CGA-193469. 44399117 Supplemental (TGAI, deg, 99%) No pH and water hardness exceeded the recommended range of the EPA guidelines requirements. Test compound: CGA-302371.

850.1075 Freshwater fish acute toxicity 44399108 Supplemental (TGAI, deg, 99%) No Only 7 fish were used per concentration. Test compound: CGA-302371.

850.1300 Freshwater invertebrate life cycle 44399121 Supplemental (TGAI, deg, 99.3%) No pH and water hardness exceeded the recommended range of the EPA guidelines requirements. Test compound: CGA-193469. 850.5400 Aquatic Plant Growth:Tier II nonvascular plants 44399161 Supplemental (TGAI, 99%) No Test compound: CGA-302371.



### Several ecological effects data gaps we re noted in the 2000 New Chemical Risk Assessment for clodinafop 2E Herbicide (HORIZON) (DP Barcode: D244333, D246816), including an avian repr oduction toxicity study. The remaining data gaps were identified for this problem formulation.

Active ingredient: Clodinafop-propargyl Avian Reproduction (OCSPP 850.2300): Subdivision E requires two avian reproduc tion studies for a complete risk characterization of the active ingredient, but the requirement is only partially fulfilled Given that chronic risk to bi rds appeared to be minimal [NOAEC = 500 mg a.i./kg-diet (the highest concentration tested) ], a mallard reproduction study was considered a guideline requirement, but at the time of the new chemical assessment (USEPA 2000), the study was not recommended to be requested because it was not considered of high value. The weight of evidence does not wa rrant the need for an additional avian reproduction study.

OCSPP 850.2100 Avian oral toxicity: Two acceptable oral toxicity studies are ava ilable, one each for the Northern bobwhite quail (MRID 44399106) and mallard duck (MRI D 44399107). However, avian acute oral toxicity data are not availa ble for passerines, which ar e required under 40 CFR Part 158 (July 1, 2010). The Part 158 data requirements sp ecify that acute avian oral toxicity data be submitted for either a mallard duck or bobwhite quail and a passerine species. ThoughPage 26 of 50 

### all four, submitted acute avian studies (oral, MRID 44399106 and 44399107, as well as dietary, MRID 44399110 and 44399109) indicated low toxicity to the parent clodinafoppropargyl, the passerine test species may i ndicate greater sensitivity. For acute and listed species LOC exceedances to take place, acute dose-based toxicity endpoints (LD 50 

### ) for passerines (approximate body weight of 20g; cons umption of short grass) would need to be on the order of 34.54 mg a.i./kg-bw and 172.7 mg a.i./kg-bw, respectively (assuming a single application rate of 0.0632 lbs a.i./A and default half- life of 35 days; using T-REX 1.5). Given that little is known about the re lative toxicities of upland game birds and waterfowl to passerines, the probability of achieving this value is uncertain. However, given that the 14-day NOAEL for the Northe rn bobwhite acute oral study (521 mg a.i./kg-bw; MRID 44399106) was on the order of the potential level at which listed species LOC exceedances might be observed ( i.e. , at LD 50 

### of 172.7 mg a.i./kg-bw), a request for a passerine study is warranted.

Passerines are the most common birds (in terms of numbers and number of species) in the United States. Many utilize agricultural fields , forests, residential areas and surrounding areas, and, therefore, have the potential to be exposed to pes ticides used in agricultural, forest, and residential settings. It is likely that, for the re quested use patterns, passerines are more likely to be exposed to clodinaf op-propargyl than upla nd game species and waterfowl. Passerines are smaller and have a higher energy requirement than larger-sized birds. As such, passerines may be more se nsitive than other birds. A protocol is requested prior to submission of the study. If oral acute toxicity data are not submitted for passerines, risk cannot be precluded for passerine species.

OCSPP 850.1400 Chronic Toxicity to Freshw ater Fish (Fish Early-life Stage) Given the broadcast (ground/aer ial) applications of clodi nafop-propargyl (currently registered for wheat), it is possible for the pa rent and its degradates to enter the aquatic ecosystem via runoff and drift; the compounds are persistent as they are stable to hydrolysis and aqueous photolys is. A chronic freshwater fish study is not available for clodinafop-propargyl or its degrad ates. The lack of these data is a noted uncertainty in the 2000 new chemical risk assessment. A fish early-life stage toxicity study conducted with the parent compound is recommended, preferably on a species already tested in the acute freshwater fish studies.



## 8. References

USEPA. 2000. New Chemical: Clodinafop 2E Herbicide (HORIZON). Chemical: 125203 / Company: 000100 Novartis Crop Pr otection. DP Barcode: D244333/ D246816. Office of Prevention, Pesticides, and T oxic Substances. Office of Pesticide Programs.Page 27 of 50 

## Appendices

– Appendix A: BEAD Re port and SLUA

– Appendix B: OPPIN Bibliography

– Appendix C: STIR/SIP model outputs

– Appendix D: Chemic al Structures

– Appendix E: Additional Discussion on Available Aquatic Toxicity Data on DegradatesPage 28 of 50Appendix A: BEAD Report and SLUAEFED Label Data ReportIngredient: Clodinafop-propargyl (125203)Current As of Date:6/1/2012NDC - No Dosage Conversion ; NS - Not SpecifiedSite DescUse GroupDescReg#LUISAcceptedDateAI%FormulationDescProductNameOriginal(Product / A.I.) Max AppRateA. I. MaxApp RateMax # Apps@ Max Rate /CCApplicationMethod TypeApplicationMethodEquipmentApplicationMethod TimingWHEATTERRESTRIALFOOD + FEED100-117310/3/20086.4ECDISCOVERNG/HORIZONNG16 fl oz/ 1 a.0632 lb / a1Broadcast.Aircraft.Foliar.WHEATTERRESTRIALFOOD + FEED100-117310/3/20086.4ECDISCOVERNG/HORIZONNG16 fl oz/ 1 a.0632 lb / a1Broadcast.Aircraft.Tillering.WHEATTERRESTRIALFOOD + FEED100-117310/3/20086.4ECDISCOVERNG/HORIZONNG16 fl oz/ 1 a.0632 lb / a1Broadcast.Ground.Foliar.WHEATTERRESTRIALFOOD + FEED100-117310/3/20086.4ECDISCOVERNG/HORIZONNG16 fl oz/ 1 a.0632 lb / a1Broadcast.Ground.Tillering.WHEATTERRESTRIALFOOD + FEED100-9079/19/200822.3ECDISCOVERHERBICIDE1 unspecifiedNDC1Broadcast.Aircraft.Foliar.WHEATTERRESTRIALFOOD + FEED100-9079/19/200822.3ECDISCOVERHERBICIDE1 unspecifiedNDC1Broadcast.Aircraft.Postemergence.WHEATTERRESTRIALFOOD + FEED100-9079/19/200822.3ECDISCOVERHERBICIDE1 unspecifiedNDC1Broadcast.Ground.Foliar.WHEATTERRESTRIALFOOD + FEED100-9079/19/200822.3ECDISCOVERHERBICIDE1 unspecifiedNDC1Broadcast.Ground.Postemergence.Page 29 of 50 

### Clodinafop-propargyl (125203) Screening Level Usage Analysis (SLUA) Date: January 18, 2012

What is a Screening Level Usage Analysis (SLUA)?

 Available estimates of pesticide usage da ta for a particular active ingredient that is used on agricultural crops in the United States.

 Pesticide usage data obtained from va rious sources. The data are then merged, averaged, and rounded so that the presented information is not proprietary, business confid ential, or trade secret. What does it contain?

 Pesticide usage data for a single active ingredient only.

 Agricultural use sites (cr ops) that the pesticide is reported to be used on.

 Available pesticide usage information fr om U.S. states that produce 80% or more of a crop, in most cases, or less than 80%, in rare cases, depending on the scope of the survey and available resources.

 Annual percent of crop treated (average & maximum) for each agricultural
crop.

 Average annual pounds of the pesticide applied for each agricultural crop (i.e., for the states surveyed, not for the entire United States). What assumptions can I make about the reported data?

 Average pounds of active ingredient applied - Values are calculated by merging pesticide usage data sour ces together; averaging across all observations, then rounding. Note: If the estimated value is less than 500, then that value is labeled <500. Estimated values between 500 & <1,000,000 are rounded to 1 significant digit. Estimated values of 1,000,000 or greater are rounded to 2 significant digits.)

 Average percent of crop treated - Values are calculated by merging data sources together; averagi ng by year, averaging across all years, & rounding to the nearest multiple of 5. Note: If the estimated value is less than 2.5, then the value is labeled <2.5. If the estimated value is less than 1, then the value is labeled <1.

 Maximum percent of crop treated - Value is the single maximum value reported across all data sources, across a ll years, & rounded up to the nearest multiple of 5. Note: If the estimated value is less than 2.5, then the value is labeled <2.5. What are the data sources used?

 USDA-NASS (United States Department of Agriculture’s National Agricultural Statistics Service) – pesticide usage data from 2003 to 2010.

 Private pesticide market research – pesticide usage data from 2003 to 2010.

 California Department of Pesticide Regulation (DPR) Pesticide Use Reporting (PUR) data for 2003 to 2009. What are the limitations to the data?

 Additional registered uses may exis t but are not included because the available surveys do not report usage (e.g., small acreage crops).Page 30 of 50 

###  Lack of reported usage data for the pesticide on a crop does not imply zero usage.

 Usage data on a particular site may be noted in data sources, but not quantified . In these instances, the site w ould not be reported in the SLUA.

 Non-agricultural use sites (e.g., turf, post-harvest, mosquito control, etc.) are not reported in the SLUA. A separate re quest must be made to receive these estimates.

 Some sites show some use, even though they are not on the label. This usage could be due to various factors, in cluding, but not limited to Section 18 requests, existing stocks of the ch emical, data coll ection errors, and experimental use permits (EUPs).Page 31 of 50 

### January 18, 2012

Screening Level Estimates of Agricultural Uses of Clodinafop-propargyl (125203) Sorted Alphabetically

Percent Crop Ttd.

Crop Lbs. A.I. Avg. Max. 1 Barley + 1,000 <1 <2.5
2 Wheat 90,000 5 10

All numbers rounded. <500 Less than 500 pounds of active ingredient <2.5 Less than 2.5 per cent of crop treated

<1 Less than 1 percent of crop treated

+ Crops not known to be listed on activ e end use product registrations or as Section 18 emergency exemptions for the period reported in this SLUA.

SLUA data sources include: USDA-NASS (United States Department of Agriculture's National Agricultural Statistics Service) Private Pesticide Market Research

These results reflect amalgamated data devel oped by the Agency and are releasable to the public.Page 32 of 50 

## Appendix B: OPPIN Bibliography

Fate Bibliography: 

# Bibliography

161-1 Hydrolysis

MRID Citation Reference

44387442 Keller, A. (1991) Hydrolysis of (inert ingredient ) Under Laboratory Conditions: Lab Project Number: 14/91: 388-91: 89AK01. Unpublished study prepared by Novartis Crop Protection AG. 39 p.
44399169 Keller, A. (1987) Hydrolysis of CGA-184927 Under Laboratory Conditions: Lab Project Number: 31/87: 185-87: 86AK01. Unpublished study prepared by Novartis Crop Protection AG. 37 p.
46012926 Spare, W. (2001) Aqueous H ydrolysis of (Carbon 14)-CGA-184927 Under Laboratory Conditions: Fina l Report. Project Number: 003/035, 66/00. Unpublished study prepared by Exygen Research. 415 p.



### 161-2 Photodegradation-water

MRID Citation Reference

44387443 Schaffer, A. (1991) Aqueous Photol ysis of (inert ingredient) Under Laboratory Conditions: Lab Projec t Number: 21/91: 381-91: 90AS01. Unpublished study prepared by Novartis Crop Protection AG. 45 p.
44399170 Keller, A. (1990) Photolysis of CGA-184927 in Aqueous Solutions Under Laboratory Conditions: Lab Project Number: 5/90: 350-90: 87AK11. Unpublished study prepared by Novartis Crop Protection AG. 35 p.
45059201 Phaff, R. (1995) Rate and Quantum Yield of the Direct Phototransformation of CGA-193469 U nder Laboratory Conditions in Water: Final Report: Lab Project Number: 525-94: 94RP04. Unpublished study prepared by Novartis Crop Protection AG. 30 p.
46012927 Anderson, W. (2002) Photodegrad ation of (Carbon 14)-CGA-184927 in pH Buffered Solution Under Artific ial Light: Final Report. Project Number: 82/00. Unpublished study prepared by Syngenta Crop Protection, Inc. 130 p.
46012928 Anderson, W. (2003) Photodegrad ation of (Carbon 14)[Phenyl]-CGA-Page 33 of 50 

### 184927 in pH 5 Buffered Solution Under Artificial Light: Final Report. Project Number: 19/02. Unpublishe d study prepared by Syngenta Crop Protection, Inc. 133 p.



### 161-3 Photodegradation-soil

MRID Citation Reference

44387444 Keller, A. (1993) Soil Photolysis of (inert ingredient) Under Laboratory Conditions: Lab Project Number: 02/93: 613-93: 92AK02. Unpublished study prepared by Novartis Crop Protection AG. 45 p.
44399171 Keller, A. (1993) Soil Photolysis of CGA-184927 Under Laboratory Conditions: Lab Project Number: 01/93: 607-93: 92AK01. Unpublished study prepared by Novartis Crop Protection AG. 48 p.



### 162-1 Aerobic soil metabolism

MRID Citation Reference

44387445 Keller, A. (1991) Degradation of (i nert ingredient) in Two Soils Under Aerobic Laboratory Conditions at 20 (degree): Lab Project Number: 89AK05: 390-91. Unpublished study prepared by Novartis Crop Protection AG. 19 p.
44387446 Keller, A. (1992) Rate of Degradatio n of (inert ingredient) in Aerobic Soil at Various Conditions: Lab Project Number: 23/92: 509-92: 91AK01. Unpublished study prepared by Novartis Crop Protection AG. 31 p.
44387447 Keller, A. (1992) Degradation of (ine rt ingredient) in Soil under Aerobic, Aerobic/Anaerobic and St erile/Aerobic Conditions at 20 (degree): Lab Project Number: 35/92: 508-92: 90AK01. Unpublished study prepared by Novartis Crop Protection AG. 48 p.
44399172 Keller, A. (1992) Degradation of CGA-184927 in Three Soils Under Aerobic Conditions at 20 (degrees centigrade): Lab Project Number: 07/92: 500-92: 90AK04. Unpublished st udy prepared by Novartis Crop Protection AG. 31 p.
44399173 Keller, A. (1989) Degradation of CGA-184927 in Soil Under Aerobic Conditions at 15 (degrees centigrad e): Lab Project Number: 27/89: 334- 89: 87AK13. Unpublished study prepar ed by Novartis Crop Protection AG. 25 p.
44399174 Keller, A. (1989) Degradation of (carbon 14)-Pyridine-Labeled CGA-Page 34 of 50 

### 184927 in Aerobic Soil at 25 (degrees centigrade): Lab Project Number: 25/89: 337-89: 87AK12. Unpublished st udy prepared by Novartis Crop Protection AG. 30 p.
44399176 Keller, A. (1989) Degradation of (carbon 14)-Phenyl-Labeled CGA184927 in Aerobic, Aerobic/Anaerobi c and Sterile/Aerobic Soil at 25 (degrees centigrade): Lab Project Number: 26/89: 335-89: 87AK12. Unpublished study prepared by Novartis Crop Protection AG. 37 p.
46012930 Spare, W. (2003) Aerobic Soil Metabolism of (Carbon 14)-PyridinylLabeled CGA-184927: Final Report. Project Number: 003/039, 2218/01. Unpublished study prepared by Exygen Research. 490 p.
46012931 Spare, W. (2003) Aerobic Soil Metabolism of (Carbon 14)-PhenylLabeled CGA-184927: Final Report. Project Number: 003/038, 207/01. Unpublished study prepared by Exygen Research. 412 p.



### 162-2 Anaerobic soil metabolism

MRID Citation Reference

44387447 Keller, A. (1992) Degradation of (ine rt ingredient) in Soil under Aerobic, Aerobic/Anaerobic and St erile/Aerobic Conditions at 20 (degree): Lab Project Number: 35/92: 508-92: 90AK01. Unpublished study prepared by Novartis Crop Protection AG. 48 p.
44399176 Keller, A. (1989) Degradation of (carbon 14)-Phenyl-Labeled CGA184927 in Aerobic, Aerobic/Anaerobi c and Sterile/Aerobic Soil at 25 (degrees centigrade): Lab Project Number: 26/89: 335-89: 87AK12. Unpublished study prepared by Novartis Crop Protection AG. 37 p.



### 162-3 Anaerobic aquatic metab.

MRID Citation Reference

44387448 Keller, A. (1992) Rate of Degrad ation of (inert ingredient) Under Aerobic, Anaerobic and Sterile Conditi ons in an Aquatic System at Two Temperatures: Lab Project Number: 08/93: 612-93: 91AK02. Unpublished study prepared by Novartis Crop Protection AG. 47 p.
44399177 Keller, A. (1993) Rate of Degradation of CGA-184927 Under Aerobic, Anaerobic and Sterile Conditions in an Aquatic System at Two Temperatures (Including Amendment 1): Lab Project Number: 07/93: 608-93: 91AK04. Unpublished study prepared by Novartis Crop Protection AG. 63 p.Page 35 of 50 

### 45059203 Keller, A. (1995) Rate of Degradation of CGA-184927 Under Aerobic, Anaerobic and Sterile Conditions in an Aquatic System at Two Temperatures: Final Report Amendment: Lab Project Number: 07/93: 608-93: 91AK04. Unpublished study prepared by Novartis Crop Protection AG. 19 p.
46012932 Concha, M. (2003) CGA-184927: An aerobic Aquatic Metabolism of [Pyridinyl-2,6](Carbon 14)-CGA-184927 in a Sediment/Water System: Final Report. Project Number: 1059W, 80/00. Unpublished study prepared by PTRL West, Inc. 266 p.
46012933 Concha, M. (2003) CGA-184927: An aerobic Aquatic Metabolism of [Phenyl-U](Carbon 14)-CGA-184927 in a Sediment/Water System: Final Report. Project Number: 1109W, 35/02. Unpublished study prepared by PTRL West, Inc. 246 p.



### 162-4 Aerobic aquatic metab.

MRID Citation Reference

44387448 Keller, A. (1992) Rate of Degrad ation of (inert ingredient) Under Aerobic, Anaerobic and Sterile Conditi ons in an Aquatic System at Two Temperatures: Lab Project Number: 08/93: 612-93: 91AK02. Unpublished study prepared by Novartis Crop Protection AG. 47 p.
44387449 Reischmann, F. (1996) Metabolism of (inert ingredient) under Aerobic Conditions in Aquatic Systems: Lab Project Number: 95RF02: 460/96. Unpublished study prepared by Novartis Crop Protection AG. 71 p.
44399177 Keller, A. (1993) Rate of Degradation of CGA-184927 Under Aerobic, Anaerobic and Sterile Conditions in an Aquatic System at Two Temperatures (Including Amendment 1): Lab Project Number: 07/93: 608-93: 91AK04. Unpublished study prepared by Novartis Crop Protection AG. 63 p.
44399178 Reischmann, F. (1996) Metabolis m of (Carbon 14)-Phenyl and (Carbon 14)-Pyridine CGA-184927 under Aerobic Conditions in Aquatic Systems: Lab Project Nos. 95RF03; 459-96. Unpublished study prepared by Novartis Crop Protection AG. 89 p.
45059203 Keller, A. (1995) Rate of Degradation of CGA-184927 Under Aerobic, Anaerobic and Sterile Conditions in an Aquatic System at Two Temperatures: Final Report Amendment: Lab Project Number: 07/93: 608-93: 91AK04. Unpublished study prepared by Novartis Crop Protection AG. 19 p.



### 163-1 Leach/adsorp/desorptionPage 36 of 50 

### MRID Citation Reference

44387450 Keller, A. (1991) Leaching Characteris tics of Aged Residues of (inert ingredient) in Two Soils after 200 mm of Artificial Rain fall: Lab Project Number: 24/91: 386-91: 90AK02/A. Unpublished study prepared by Novartis Crop Protection AG. 33 p.
44387451 Keller, A. (1991) Leaching Model Study with (inert ingredient) in Four Soil Types: Lab Project Number : 89AK03: 389-91. Unpublished study prepared by Novartis Cr op Protection AG. 36 p.
44387452 Keller, A. (1991) Leaching Characteris tics of Aged Residues of (inert ingredient) in Two Soils after 508 mm of Artificial Rain fall: Lab Project Number: 25/91: 383-91: 90AK02/B. Unpublished study prepared by Novartis Crop Protection AG. 35 p.
44387453 Keller, A. (1990) Adsorption / Desorption of (inert ingredient) in Various Soil Types: Lab Projec t Number: 41/90: 354-90: 89AK02. Unpublished study prepared by Novartis Crop Protection AG. 34 p.
44399179 Keller, A. (1990) Leaching Character istics of Aged Residues of (carbon 14)-CGA-184927 in Two Soil Types Af ter 508 mm Rainfall: Lab Project Number: 10/90: 346-90: 88AK09-2. Unpublished study prepared by Novartis Crop Protection AG. 37 p.
44399180 Keller, A. (1990) Leaching Character istics of Aged Residues of (carbon 14)-CGA-184927 in Two Soil Types Af ter 200 mm Rainfall: Lab Project Number: 6/90: 352-90: 88AK09-1. Unpublished study prepared by Novartis Crop Protection AG. 35 p.
44399181 Keller, A. (1989) Adsorption/Desorption of CGA-184927 in Various Soil Types: Lab Project Number : 29/89: 331-89: 88AK12. Unpublished study prepared by Novartis Crop Protection AG. 34 p.
44399182 Keller, A. (1989) Leaching Model Study with CGA-184927 in Four Soil Types: Lab Project Number: 23/ 89: 336-89: 88AK02. Unpublished study prepared by Novartis Cr op Protection AG. 29 p.
44831201 Hill, A. (1994) CGA 193469: Adsorption/Desorption in Three Soils: Final Report: Lab Project Numb er: HE 380/221: 910-99: 380/221-1015. Unpublished study prepared by Hazleton Europe. 84 p.
44831202 Hill, A. (1994) CGA 302371: Adsorption/Desorption in Three Soils: Final Report: Lab Project Numb er: 380/222: 911-99: P9093D. Unpublished study prepared by Hazleton Europe. 86 p.
46012934 Spare, W. (2003) Adsorption and Desorption Study to Determine the Mobility and Distri bution of [2,6-(Carbon 14)]CGA-302371 in Soil: Final Report. Project Number: EXP/003/042, 003/042, 72/00. Unpublished study prepared by Exygen Research. 296 p.Page 37 of 50 

### 46012935 Spare, W. (2003) Adsorption and Desorption Study to Determine the Mobility and Distri bution of [Phenyl-U-(C arbon 14)]CGA-184927 in Soil: Final Report. Project Number: 003/041, 69/00, 02P/003/041. Unpublished study prepared by Exygen Research. 306 p.
46012936 Spare, W. (2003) Adsorption and Desorption Study to Determine the Mobility and Distri bution of [Phenyl-U-(C arbon 14)]CGA-193468 in Soil: Final Report. Project Number: 003/046, 31/03, EXP/003/046. Unpublished study prepared by Exygen Research. 303 p.
46012937 Spare, W. (2003) Adsorption and Desorption Study to Determine the Mobility and Distribution of [Phenyl-U-(Carbon 14)]CGA-193469. Project Number: 003/043, EXP/003/043, 71/00. Unpublished study prepared by Exygen Research. 304 p.



### 164-1 Terrestr ial field dissipation

MRID Citation Reference

44399183 Purdy, J. (1997) Detailed St udy Summary Covering CGA-184927 and (Inert) Soil Dissipation Studies in Canada: Lab Project Number: 500-97. Unpublished study prepared by Novartis Crop Protection, Inc. 4 p.
44399184 Purdy, J. (1993) Horiz on 240EC (Topik 240EC) (CGA-184927 (Clodinafop-Propargyl) + (Inert In gredient) (Includes Volume 1: Environmental Chemistry and Fate Assessment and Volume 2: Soil Dissipation Studies in Canada): Lab Project Nos. 1603/91; 1603/92: 626- 93. Unpublished study prepared by Nova rtis Crop Protection AG. 143 p.
44399188 Altenburger, E. (1991) Determinatio n of Residues of Metabolites CGA193469 and CGA-153433 by Liquid Ch romatography (HPLC): Lab Project Number: REM 138.04: 515-9 7. Unpublished study prepared by Novartis Crop Protection AG. 19 p.
44399189 Mair, P. (1992) Determination of Residues of Metabolites CGA-193469 and CGA-153433 by Liquid Chromat ography (HPLC): Lab Project Number: REM 138.07: 517-97. Unpublished study prepared by Novartis Crop Protection AG. 16 p.
44646101 Nelson, S.; Bruns, G. (1998) Method of Analysis for the Determination of CGA 184927 and the Acid Meta bolite CGA 193469 by GC/MS: LabProject Number: 321-98: 147.00. Unpublished study prepared by EnviroTest Laboratories. 40 p.
44646102 Nelson, S.; Bruns, G. (1998) Method of Analysis for the Determination of CGA 302371 (UE Metabolite) in Soil by LC/MS: Lab Project Number: MS 47.00: 320-98. Unpublished study prepared by Enviro-Test Laboratories. 23 p.Page 38 of 50 

### 46012938 Chamkasem, N. (2002) Analytical Method 38-01 for the Determination of CGA-184927 and its Degradat es CGA-193468, CGA-193469 and CGA-302371 and (Inert Ingredient) and its Degradate (Inert Ingredient) in Soil by High Performance Liquid Chromatography with Mass Spectrometric Detection. Projec t Number: 38/01. Unpublished study prepared by Syngenta Crop Protection, Inc. 102 p.
46012939 Speth, R. (2003) Terrestrial Fiel d Dissipation of Discover Herbicide (CGA-184927) on Bare Soil and Spring Wheat in North Dakota: Final Report. Project Number: 36/01, 46966, 14663/1. Unpublished study prepared by Analytical Bio-Chemis try Labs., Inc., ABC Laboratories, Inc. and Ricerca Biosciences, LLC. 510 p.
46373401 Speth, R.; Cassidy, P. (2004) Stability of CGA-184927, CGA-193468, CGA-193469, CGA-302371, CGA-1 85072 and CGA-153433 in Soil Under Freezer Storage Conditi ons. Project Number: 14900, 1823/02. Unpublished study prepared by Ricerca Biosciences, LLC. 110 p.



### 164-2 Aquatic field dissipation

MRID Citation Reference

45059202 Ellgehausen, H. (1999) Calculati on of the Degradation Kinetics of Metabolites CGA-193469, CGA-193 468 and CGA-302371 in Aquatic Systems: Final Report: Lab Project Number: 99EEH05: 1218-99. Unpublished study prepared by Novartis Crop Protection AG. 28 p.



### 165-4 Bioaccumulation in fish

MRID Citation Reference

44387455 Burri, R. (1993) Accumulation and Elimination of (inert ingredient) by Bluegill Sunfish in a Dynamic Flow-through System: Lab Project Number: 313143: 628-93. Unpublished study prepared by RCC Umweltchemie AG. 103 p.
44719601 Peters, J. (1998) Uptake, Depuratio n, and Bioconcentration of (carbon 14)-Pyridinyl-CGA-184927 in Fish Under Flow-Through Test Conditions: Lab Project Nu mber: ABR-98070: 61-98: 44374. Unpublished study prepared by Novartis Crop Protection, Inc., ABC Laboratories, Inc. and Covance Laboratories. 456 p.



### 860.1380 Storage stability dataPage 39 of 50 

### MRID Citation Reference

46012916 Hamilton, L. (2001) Residue Stability of CGA-184927 and (Inert Ingredient) and Their Metabolites, CGA-193469 and (Inert Ingredient), Fortified into Wheat Forage and Ha y Under Freezer Storage Conditions: Final Report. Project Number: 128/ 99. Unpublished study prepared by Syngenta Crop Protection, Inc. 120 p.
46012917 Hamilton, L. (2001) Residue Stability of CGA-193469 and (Inert Ingredient), Fortified into Wh eat Germ Under Freezer Storage Conditions: Final Report. Projec t Number: 224/01. Unpublished study prepared by Syngenta Crop Protection, Inc. 47 p.

Eco Bibliography:


## 125203 Clodinafop-propargyl Eco Effects Bibliography
71-1 Avian Singl e Dose Oral Toxicity

MRID Citation Reference

44387406 Hakin, B.; Johnson, A.; Anderson, A. et al. (1988) Acute Oral Toxicity (LD50) of (inert ingredient) to the Bobwhite Quail: Lab Project Number: CBG 471/89310: 215-88. Unpublished study prepared by Huntingdon Research Centre, Ltd. 39 p.

44387407 Hakin, B.; Norman, A.; Anderson, A. et al. (1989) Acute Oral Toxicity (LD50) of (inert ingredient) to the Mallard Duck: Lab Project Number: CBG 472/89311: 344-89. Unpublished study prepared by Huntingdon Research Centre, Ltd. 37 p.

44399106 Hakin, B.; Norman, A.; Anderson, A. et al. (1990) Acute Oral Toxicity (LD50) of CGA-184927 to the Bobwhite Quail: Lab Project Number: CBG 467/89396: 341-89. Unpublished study prepared by Huntingdon Research Centre, Ltd. 39 p.

44399107 Hakin, B.; Rodgers, M.; Norman, A. et al. (1990) Acute Oral Toxicity (LD50) of CGA-184927 to the Mallard Duck: Lab Project Number: CBG 468/89444: 342-89. Unpublished study prepared by Huntingdon Research Centre, Ltd. 40 p.



## 71-2 Avia n Dietary Toxicity

MRID Citation Reference

44387408 Hakin, B.; Norman, A.; Rodgers, A. et al. (1990) The Subacute Dietary Toxicity (LD50) of (inert ingredient) to the Mallard Duck: Lab ProjectPage 40 of 50 Number: CBG 470/89102: 346-89. Unpublished study prepared by Huntingdon Research Centre, Ltd. 36 p.
44387409 Hakin, B.; Norman, A.; Rodgers, A. et al. (1989) The Dietary Toxicity (LD50) of (inert ingredient) to the Bobwhite Quail: Lab Project Number: CBG 469/89703: 345-89. Unpublished study prepared by Huntingdon Research Centre, Ltd. 38 p.
44399109 Hakin, B.; Norman, A.; Rodgers, M. et al. (1989) The Subacute Dietary Toxicity (LC50) of CGA-184927 to Mallard Duck: Lab Project Number: 466/89118: 212-88: CBG/466. Un published study prepared by Huntingdon Research Centre, Ltd. 37 p.
44399110 Hakin, B.; Rodgers, M.; Norman, A. et al. (1990) The Dietary Toxicity (LC50) of CGA-184927 to the Bobwhite Quail: Lab Project Number: CBG 465/89445: 343-89. Unpublished study prepared by Huntingdon Research Centre, Ltd. 38 p.



## 71-4 Avian Reproduction

MRID Citation Reference

44399111 Johnson, A.; Healey, G.; Anderson, A. et al. (1993) CGA-184927-- Mallard Duck Dietary Reproduction Study: Lab Project Number: CBG 547/931488: 512-92. Unpublished study prepared by Huntingdon Research Centre, Ltd. 178 p.

44399112 Johnson, A.; Healey, G.; Anderson, A. et al. (1993) CGA-184927-- Bobwhite Quail Dietary Reproduction Study: Lab Project Number: CBG 545/931487: 513-92. Unpublished study prepared by Huntingdon Research Centre, Ltd. 245 p.



## 72-1 Acute Toxicity to Freshwater Fish

MRID Citation Reference

44387410 Rufli, H.; Lanter, F.; de Morsier, A. (1988) Report on the Test for Acute Toxicity of (inert ingredient) to Bluegill (Lepomis macrochirus): LabProject Number: 871686: 217-88. Unpublished study prepared by CibaGeigy, Ltd. 17 p.

44387411 Rufli, H.; Dieterle, R.; de Morsie r, A. (1988) Report on the Test for Acute Toxicity of (inert ingredient) to Rainbow Trout (Salmo gairdneri): Lab Project Number: 871684: 218-88. Unpublished study prepared by Ciba-Geigy, Ltd. 17 p.

44399108 Rufli, R.; Bader, U.; Gonzalez-Val ero, J. (1995) Acute Toxicity of CGA302371 (Metabolite of CGA-184927) to Rainbow Trout (Oncorhynchus mykiss) in the Static System: Lab Project Number: 951511: 752-95.Page 41 of 50 Unpublished study prepared by Ciba-Geigy, Ltd. 30 p.

44399113 Rufli, H.; Heinemann, G.; de Morsier, A. (1989) Report for Acute Toxicity of CGA-184927 Technical to Bluegill (Lepomis macrochirus): Lab Project Number: 881071: 213-88. Unpublished study prepared by Ciba-Geigy, Ltd. 21 p.

44399114 Rufli, H.; Dieterle, R.; de Morsier, A. (1989) Test for Acute Toxicity of CGA-184927 Technical to Rainbow Trout (Salmo gairdneri): LabProject Number: 881069: 214-88. Unpublished study prepared by CibaGeigy, Ltd. 24 p.

44399118 Vial, A.; Bader, U.; de Morsier, A. (1990) Report on the Prolonged Toxicity Test of CGA-184927 Technical to Rainbow Trout: Lab Project Number: 901140: 356-90. Unpublished study prepared by Ciba-Geigy Ltd. 36 p.

44561101 Ward, T.; Magazu, J.; Boeri, R. (1998) Acute Toxicity Of CGA-184927 to the Rainbow Trout, Oncorhynch us mykiss: Lab Project Number: 1422-NO. Unpublished study prepared by T.R. Wilbury Labs, Inc. 29 p.



## 72-2 Acute Toxicity to Freshwater Invertebrates

MRID Citation Reference

44387412 Rufli, H.; Lanter, F.; de Morsier, A. (1988) Report on the Test for Acute Toxicity of (inert ingredient) to Daphnia magna: Lab Project Number: 871681: 216-88. Unpublished study pr epared by Ciba-Geigy, Ltd. 18 p.

44399115 Rufli, H.; Dieterle, R.; de Morsie r, A. (1988) Report on the Test for Acute Toxicity of CGA-184927 Technical to Daphnia magna: Lab Project Number: 871491: 201-87: 740/87. Unpublished study prepared by Ciba-Geigy, Ltd. 19 p.

44399116 Putt, A.; Brown, M.; Kendall, T. et al. (1993) CGA-193469--Acute Toxicity to Daphnids (Daphnia magna) Under Static Renewal Conditions: Lab Project Number: 93-12-5071: 629-93: 1781.0893.6386.110. Unpublished st udy prepared by Springborn Labs., Inc. 72 p.

44399117 Neumann, C.; Bader, U.; Gonzalez-Valero, J. (1996) Acute Toxicity Test of CGA-302371 (Metabolite of CGA-184927) to the Cladoceran Daphnia magna Under Static Conditions: Lab Project Number: 951512: 749-95: I95-22. Unpublished study prep ared by Ciba-Geigy Ltd. 36 p.

44561102 Ward, T.; Magazu, J.; Boeri, R. (1998) Acute Toxicity Of CGA-184927 to the Daphnid, Daphnid magna: Lab Project Number: 1423-NO: 589- 97. Unpublished study prepared by T.R. Wilbury Labs., Inc. 27 p.


## 72-4 Fish Early Life Stag e/Aquatic Invertebrate Life Cycle Study

MRID Citation ReferencePage 42 of 50 44399119 Hertl, J.; Schreitmuller, J. (1996) Influence of CGA-184927 Technical on Survival and Reproduction of Daphnia magna in a Semistatic Test (21 days) at pH 6.7--7.0: Lab Project Number: 566703: 463-96: 566704. Unpublished study prepared by RCC Umweltchemie GmbH & Co. KG. 45 p.

44399120 Vial, A.; Bader, U.; de Morsier, A. (1990) Report on the Reproduction Test of CGA-184927 Technical to Daphnia (Daphnia magna Straus 1820): Lab Project Number: 901139: 355-90: 90 11 39. Unpublished study prepared by Ciba-Geigy, Ltd. 33 p.

44399121 Grade, R.; Bader, U.; Gonzalez-Valero, J. (1995) Report on the Reproduction Test of CGA-193469 to Daphnia (Daphnia magna Straus 1820) Under Semi-Static Conditions: Lab Project Number: 951509: 751- 95. Unpublished study prepared by Ciba-Geigy, Ltd. 36 p.



## 122-1 Seed Germination/S eedling Emergence and Vegetable Vigor

MRID Citation Reference

44555002 Schwab, D. (1998) Evaluati ng the Effects on CGA-184927 on the Emergence and Vegetative Vigor of Non-Target Terrestrial Plants: Lab Project Number: 44185. Unpublished study prepared by ABC Laboratories, Inc. 179 p.


## 850.4225 Seedling emergence, Tier II (formerly 123-1)

MRID Citation Reference

46012902 Porch, J.; Martin, K.; Krueger, H. (2002) CGA-193469: A Toxicity Test to Determine the Effects on Seedling Emer gence of Ten Species of Plants: Final Report. Project Number: 528/145, 1638/02. Unpublished study prepared by Wildlife International, Ltd. 131 p.



## 850.4250 Vegetative vigor, Tier II (formerly 123-1)

MRID Citation Reference

46012901 Porch, J.; Martin, K.; Krueger, H. (2002) CGA-193469: A Toxicity Test to Determine the Effects on Vegetative Vigour of Ten Species of Plants: Final Report. Project Number: 528/146, 03/02. Unpublished study prepared by Wildlife International, Ltd. 197 p.Page 43 of 50 

## 123-2 Aquatic plant growth

MRID Citation Reference

44399161 Grade, R.; Bader, U.; Gonzalez-Val ero, J. (1995) Growth Inhibition Test of CGA-302371 (Metabolite of CGA-184927) to Green Algae (Selenastrum capricornotum) in A Static System: Lab Project Number: 951510: 750-95: I/95-22. Unpublished study prepared by Ciba-Geigy Ltd. 29 p.

44399162 Grade, R.; Bader, U.; de Morsier, A. (1993) Report on the Growth Inhibition Test of CGA-184927 Technical to Green Algae, Scenedesmus subspicatus: Lab Project Number: 928202: 514-92: 921536. Unpublished study prepared by Ciba-Geigy Ltd. 27 p.

44399163 Hertl, J.; Schreitmuller, J. (1996) Toxicity of CGA-184927 Technical to Scenedesmus subspicatus in an Algal Growth Inhibition Test at pH 7.0: Lab Project Number: 566701: 461-96: 566702. Unpublished study prepared by RCC Umweltchemie GmbH & Co. KG. 41 p.

44399164 Grade, R.; Bader, U.; de Morsier, A. (1993) Report on the Growth Inhibition Test of CGA-184927 Tec hnical to Blue Algae (Microcystis aeruginosa): Lab Project Number: 928201: 516-92: 921535. Unpublished study prepared by Ciba-Geigy, Ltd. 27 p.

44399165 Hoberg, J.; Smith, H.; Gibbons, J. et al. (1993) CGA-184927--Toxicity to Duckweed, Lemna gibba: Lab Project Number: 93-6-4832: 614-93: 1781.0593.6362.410. Unpublished stud y prepared by Springborn Labs., Inc. 73 p.

44399166 Grade, R.; Bader, U.; de Morsier, A. (1993) Report on the Growth Inhibition Test of CGA-184927 Technical to Diatoms (Navicula pelliculosa): Lab Project Number: 928203: 515-92: 921537. Unpublished study prepared by Ciba-Geigy, Ltd. 27 p.

44561103 Ward, T.; Magazu, J.; Boeri, R. (1998) Growth And Reproduction Toxicity Test With CGA-184927 and the Freshwater Alga, Anabaena flos-aquae: Lab Project Number: 1421-NO: 592-97. Unpublished study prepared by T.R Wilbury Labs, Inc. 29 p.

44561104 Ward, T.; Magazu, J.; Boeri, R. (1998) Growth and Reproduction Toxicity Test with CGA-184927 and the Freshwater Alga, Selenastrum capricornutum: Lab Project Number: 1419-NO: 591-97. Unpublished study prepared by T.R. Wilbury Labs, Inc. 29 p.



## 141-1 Honey bee acute contact

MRID Citation Reference

44399167 Cole, J. (1987) The Acute Contact and Oral Toxicity to Honeybees of Compound CGA-184927: Lab Project Number: CBG 447/871222: 202- 87: CBG/447D. Unpublished study prepared by Huntingdon Research Centre, Ltd. 17 p.Page 44 of 50 

## Appendix C: STIR/SIP model outputs

STIR – ground spray



## Input

Application and Chem ical Information

Enter Chemical Name Clodinafoppropargyl Enter Chemical Use wheat Is the Application a Spray? (enter y or n) y If Spray What Type (enter ground or air) ground Enter Chemical Molecu lar Weight (g/mole) 349.74 Enter Chemical Vapor Pressure (mmHg) 2.39E-08 Enter Application Rate (lb a.i./acre) 0.0632 Toxicity Properties
Bird Enter Lowest Bird Oral LD 50 (mg/kg bw) 1455 Enter Mineau Scaling Factor 1.15 Enter Tested Bird Weight (kg) 0.178 Mammal Enter Lowest Rat Oral LD 50 (mg/kg bw) 1392 Enter Lowest Rat Inhalation LC 50 (mg/L) 2.3 Duration of Rat Inhalation Study (hrs) 4 Enter Rat Weight (kg) 0.35 

## Output Results Avian (0.020 kg ) Maximum Vapor Concentration in Air at Saturation (mg/m 3 ) 4.50E-04 Maximum 1-hour Vapor Inhalation Dose (mg/kg) 5.65E-05 Adjusted Inhalation LD 50 1.34E+01 Ratio of Vapor Dose to Adjusted Inhalation LD 50 4.22E-06 Exposure not Likely Significant Maximum Post-treatment Spray Inhalation Dose (mg/kg) 6.68E-03 Ratio of Droplet Inhalation Dose to Adjusted Inhalation LD 50 4.98E-04 Exposure not Likely Significant 

### Results Mammalian (0.015 kg ) Maximum Vapor Concentration in Air at Saturation (mg/m 3 ) 4.50E-04 Maximum 1-hour Vapor Inhalation Dose (mg/kg) 7.11E-05 Adjusted Inhalation LD 50 1.37E+02 Ratio of Vapor Dose to Adjusted Inhalation LD 50 5.19E-07 Exposure not Likely Significant Maximum Post-treatment Spray Inhalation Dose (mg/kg) 8.39E-03 Ratio of Droplet Inhalation Dose to Adjusted Inhalation LD 50 6.13E-05 Exposure not Likely SignificantPage 45 of 50 

### STIR – Aerial spray



## Input

Application and Chem ical Information

Enter Chemical Name Clodinafoppropargyl Enter Chemical Use wheat Is the Application a Spray? (enter y or n) y If Spray What Type (enter ground or air) air Enter Chemical Molecu lar Weight (g/mole) 349.74 Enter Chemical Vapor Pressure (mmHg) 2.39E-08 Enter Application Rate (lb a.i./acre) 0.0632 Toxicity Properties
Bird Enter Lowest Bird Oral LD 50 (mg/kg bw) 1455 Enter Mineau Scaling Factor 1.15 Enter Tested Bird Weight (kg) 0.178 Mammal Enter Lowest Rat Oral LD 50 (mg/kg bw) 1392 Enter Lowest Rat Inhalation LC 50 (mg/L) 2.3 Duration of Rat Inhalation Study (hrs) 4 Enter Rat Weight (kg) 0.35 

## Output Results Avian (0.020 kg ) Maximum Vapor Concentration in Air at Saturation (mg/m 3 ) 4.50E-04 Maximum 1-hour Vapor Inhalation Dose (mg/kg) 5.65E-05 Adjusted Inhalation LD 50 1.34E+01 Ratio of Vapor Dose to Adjusted Inhalation LD 50 4.22E-06 Exposure not Likely Significant Maximum Post-treatment Spray Inhalation Dose (mg/kg) 6.07E-03 Ratio of Droplet Inhalation Dose to Adjusted Inhalation LD 50 4.53E-04 Exposure not Likely Significant 

### Results Mammalian (0.015 kg ) Maximum Vapor Concentration in Air at Saturation (mg/m 3 ) 4.50E-04 Maximum 1-hour Vapor Inhalation Dose (mg/kg) 7.11E-05 Adjusted Inhalation LD 50 1.37E+02 Ratio of Vapor Dose to Adjusted Inhalation LD 50 5.19E-07 Exposure not Likely Significant Maximum Post-treatment Spray Inhalation Dose (mg/kg) 7.63E-03 Ratio of Droplet Inhalation Dose to Adjusted Inhalation LD 50 5.57E-05 Exposure not Likely SignificantPage 46 of 50 

### SIP

Table 1. Inputs Parameter Value Chemical name clodinafop-propargyl Solubility (in water at 25 o C; mg/L) 4

Mammalian LD 50 (mg/kg-bw) 1392 Mammalian test species laboratory rat Body weight (g) of "other" mammalian species

Mammalian NOAEL (mg/kg-bw) 2.5 Mammalian test species laboratory rat Body weight (g) of "other" mammalian species

Avian LD 50 (mg/kg-bw) 1455 Avian test species northern bobwhite quail Body weight (g) of "other" avian species Mineau scaling factor 1.15

Mallard NOAEC (mg/kg-diet) Bobwhite quail NOAEC (mg/kg-diet) 500

Table 2. Mammalian Results Parameter Acute Chronic Upper bound exposure (mg/kg-bw) 0.6880 0.6880 Adjusted toxicity value (mg/kg-bw) 1070.6715 1.9229 Ratio of exposure to toxicity 0.0006 0.3578

Conclusion* Drinking water exposure alone is NOT a potential

concern for mammals Drinking water exposure alone is NOT a potential

concern for mammals

Table 3. Avian Results Parameter Acute Chronic Upper bound exposure (mg/kg-bw) 3.2400 3.2400 Adjusted toxicity value (mg/kg-bw) 1048.2249 53.1492 Ratio of exposure to acute toxicity 0.0031 0.0610

Conclusion* Drinking water exposure alone is NOT a potential concern for birds Drinking water exposure alone is NOT a potential concern for birds

*Conclusion is for drinking water exposure alone. This does not combine all routes of exposure. Therefore, when aggregated with other routes ( i.e ., diet, inhalation, dermal), pesticide exposure through drinking water may contribute to a total exposure that has potential for effects to non-target animals.Page 47 of 50 

## Appendix D: Chemical StructuresPage 48 of 50Page 49 of 50 

## Appendix E. Additional Inform ation and Uncertainties with Availability Aquatic Toxicity Studies Conducted with Degradates of Clodinafop-propargyl

Acute toxicity classifications indicate that the parent compound is highly toxic to freshwater fish and at most sl ightly to moderately toxic to freshwater invertebrates. The degradate CGA-302371 is practically non-toxic to freshwater fish and freshwater invertebrates and appears to be less toxic to freshwater organisms (f ish, invertebrates, and green algae) than the parent. The degradat e CGA-193469 is at most moderately toxic to freshwater invertebrates. Available data (acute and chronic data on the freshwater invertebrate) on the parent, clodinafop-pr opargyl and the primary degradate, CGA193469, suggest that the re lative toxicity is uncertain becau se the data on the parent is either based on a non-definitive valu es (acute) or is not available ( i.e., classified as invalid, chronic). A comparison of non-vascular aquatic plant data s uggests that the green algae ( S. subspicatus ) is less sensitive to the degradate CGA-302371 than it is to the parent compound; however, there are no data available on the primary degradate, CGA193469. Below is a discussion on the available toxicity data conducted with clodinafoppropargyl, as well as an y tested degradates:

1) All acute freshwater invertebrate data on the parent and degradate CGA193469 2 

### are non-definitive endpoints. For exampl e, the freshwater invertebrate study (MRID 44561102) tested the daphnid at levels that far exceed cl odinafop-propargyl’s limit of solubility yet no mortality was observe d, but at levels below water solubility (in the MRID 44561102) some mortality was observe d. Ultimately, there is variability across studies in the freshwater invertebrate data and no clear explanation as to the mortality observed at lower concentrations. Furthermor e, the freshwater i nvertebrate study (MRID 44399116) with the degradate (CGA-193469) is based on testing only a single concentration in which the solubility limit is not reported and no solvent is used. Although available freshwater invertebrate st udies reported non-defi nitive endpoints that are at levels that exceed the surface water EEC for wheat (0.000206 mg/L for the parent; USEPA 2000), even when assuming the use of these values as defi nitive endpoints to calculate RQs, the compounds tested (CGA-193469, CGA-302371, and parent), are not expected to lead to effects when used on wh eat at the currently registered application
rate. 2) An available rainbow trout ( Oncorhynchus mykiss ) study on the degradate CGA-302371 yielded a non- definitive endpoint. However, this freshwater fish data (MRID 44399108) on the degradate (CGA-302371) had no mortality and good recovery of tested compound (mean measured concentr ations were 95-104% of nominal) for all five tested concentrations, even though the solubility limit of the degradate is not

2 The only freshwater fish data on the degradate CGA-302371 is also based on a non-definitive endpoint. However, the freshwater fish data (MRID 44399108) on the degradate (CGA-302371) had no mortality and good recovery of tested compound (mean measured concentrations were 95-104% of nominal) for all five tested concentrations. The daphnid study (MRID 44399117) on the same degradate (CGA-302371) is also based on a non-definitive endpoint, but there was 20% mortality present at the termination of the study for the highest tested concentration.Page 50 of 50 

### reported. However, a comparison of the freshwater fish studies on the parent compound indicates that the bluegill sunfish ( Lepomis macrochirus ) may be more sensitive to the parent (0.24 mg total /L, 95%CI: 0.12-0.26 mg total/L , MRID 44399113) than is the rainbow trout ( Oncorhynchus mykiss : 0.30 mg a.i. /L,95% CI: 0.26-0.34 mg a.i./L, MRID 44561101; 0.39 mg total /L, 95% CI: 0.22-0.78 mg total/L, MRID 44399114). The confidence intervals seemingly overlap (for MRIDs 44399113 and 44561101), but it is possible that with centrifugation the bluegi ll endpoint would have been lower than reported.

3) The only acute bluegill study (MRID 44399113) and one of two trout studies (MRID 44399114) did not centrifuge samples prior to analysis even though a precipitate was observed. However, measured concentratio ns were progressively increasing and not reflecting sampling undissolved material (so stated for MRID 44399114 3 

### ), a solvent (DMF) was used, and the test concentrations were below the aquatic solubility limit of the parent (4 mg/L at 25 o 

### C). The endpoint values are, at best, based on total test compound present, and may not be representative of bioavailable test concentrations (see comparison of endpoints above). Although the endpoints did not differ greatly from the acceptable trout study, which did not report a precipitate (MRID 44561101), it is possible that the actual bioavailable concentrations could yield lower endpoints in the studies where precipitate was observed had the samples been centrifuged.

3 A reclassification of the trout study(MRID 44399114) is not necessary and a new trout study is not needed. See data gaps section for freshwater fish discussion.