### 4UN IT E D S T A T ES ENV I R O NMEN T AL P R OT EC TIO N AGENCY



### WASHINGTON D.C., 20460

M EM O RAN D U M D a t e : Ma r c h 22, 2 016
S ubje c t : 

### Preliminary Env i ronmental Fate and Ecological Risk Assessment for the Registration Review of Ethalfluralin

To :

Fro m : 

### PC Code: 113 1 

### OJ

DP Barcodes : D429845

Kelly Ba ll ard, Chem i ca l Review Manager

Melissa Grable

, Team Leader

Neil Anderson

, Chief

Risk Management and Implementation Branch I

Pesticide Re-evaluat i on Divi s ion (7505P)

/_ 

### Geoffrey Sinclair, Ph.D.

,**Biol~ ~**  

### Michael Barrett

, Ph

. D.

,**Chem ~**  

### E nvironmental Risk Branch 5

E nvironmental Fate and Effects D i vision (7507P)

Rev i ew e d By: 

### Hannah Yingling

, Biologist

Mohammed Ruhman

, Ph

. D

. , Senior Agronom i st
Env i ronmental Risk Branch 5
Environmental Fate and Effects Division (7507P)

A pp rov ed: 

### Mah Shamim

, Ph

. D

. , Branch Ch i ef
Environmental Risk Branch 5

E nvironmental Fate and Effects D i vis i on (750 P)

Office of Pesticide Programs

The Environmental Fate and Effects Division (EFED) has completed the ecological effects and

environmental fate preliminary risk assessment conducted as part of the registration review of

th e herbicide etha l flura li n. An eva l uation of ecological risk to aquatic and terrestrial organisms

as a resu l t of the use of ethalflura l in is summarized in the Executive Summary and the Risk

Characterization sections of the attached document. A separate document containing a preliminary prob l em formulation was prepared for ethalfluralin (DP Barcode D382172) in March

2011 and was released for public comment.

### 2 

# Preliminary Environmental Fate and Ecological Risk
Assessment for the Registration Review of
Ethalfluralin

Prepared by: Geoffrey Sinclair

, Ph.D., Biologist
Michael Barrett

, Ph.D., Environmental Scientist U. S. Environmental Protection Agency Office of Pesticide Programs Environmental Fate and Effects Division
Environmental Risk Branch V 1200 Pennsylvania Ave., NW
Mail Code 7507P Washington, DC 20460 Reviewed by:
Mah Shamim

, Ph.D., Branch Chief

### 3 Table of Contents

1. Executive Summary

................................ ................................ ................................ ................ 7
2. Mechanism of Action

................................ ................................ ................................ .............. 9
3. Use Characterization

................................ ................................ ................................ ............... 9
3.1 Labelled Use

................................ ................................ ................................ ..................... 9
3.2 Usage

................................ ................................ ................................ .............................. 15
4. Exposure Charac terization

................................ ................................ ................................ .... 17
4.1 Environmental Fate and Transport Summary

................................ ................................ 17
4.2 Exposure Pathways

................................ ................................ ................................ ........ 22
4.3 Aquatic Exposure Analysis

................................ ................................ ............................ 24
4.4 Clean Water Act

................................ ................................ ................................ ............. 28
4.5 Terrestrial Exposure Analysis

................................ ................................ ........................ 28
5 Ecological Effects Characterization

................................ ................................ ...................... 3 7
5.5 Aquatic Effects Summary

................................ ................................ .............................. 38
5.6 Terrestrial Effects Summary

................................ ................................ .......................... 41
5.7 ECOTOX Open Literature

................................ ................................ ............................. 45
5.8 Review of Incident Data

................................ ................................ ................................ . 45

6 Risk Characterization

................................ ................................ ................................ ............ 54
6.5 Risk Estimation

................................ ................................ ................................ .............. 54

6.6 Non

- target Aquatic Animals and Plants

................................ ................................ ......... 55
6.3 Non

- target Terrestrial Animals

................................ ................................ ...................... 58

7 Risk Description

................................ ................................ ................................ .................... 64
7.1 Risk to Non

- Target Aquatic Organisms

................................ ................................ ......... 64
7.2 Risk to Non

- Target Terrestrial Organisms

................................ ................................ ..... 67
8 Uncertainties, Assumptions, and Limitations

................................ ................................ ....... 72
9 Endocrine Disruptor Screening Program

................................ ................................ .............. 76
10 Federally Threatened and Endangered (Listed) Species of Concern

................................ .... 76
11 Conclusions

................................ ................................ ................................ ........................... 77
12 References

................................ ................................ ................................ ............................. 85 Appendix A. Environmental Fate and Ecological Effects Data for Ethalfluralin

........................ 87 Appendix B. Ethafluralin ECO Effects Bibliography

................................ ................................ .. 93 Appendix C. Aquatic Exposure Modeling Inputs and Results

................................ .................. 103 Appendix D. Sample TREX Files

................................ ................................ .............................. 122 Appendix E. Sample TerrPlant Files

................................ ................................ ......................... 124 Appendix F. Sample KABAM Files

................................ ................................ .......................... 127 Appendix G. Risk Quotient Method

................................ ................................ .......................... 130 Appendix H. Environmental Degradates of Ethalfluralin

................................ ........................... 132

### 4 

## Table of Tables

Table 1. Summary of ethalfluralin product labels registration numbers.

................................ .... 10 Table 2. Summary of ethalfluralin application rates and methods by crop si te.

........................... 12 Table 3. Screening Level Estimates of Agricultural Uses of Ethalfluralin for 2004

- 2013.

......... 15 Table 4. Summary of Physicochemical Properties of Ethalfluralin.

................................ ............ 20 Table 5. Ethalfluralin physicochemical and fate property inputs for the SWCC model.

............ 24 Table 6. SWCC crop scenario and application

- related input parameter values for ethalfluralin aquatic exposure estimation.

................................ ................................ ................................ ......... 25 Table 7. SWCC estimated upper

- bound peak, 21

- day and 60

- day concentrations in the surface water column and sediment for ethalfluralin at the highest application rate for proposed crop

uses.

................................ ................................ ................................ ................................ ............... 26 Table 8. Input parameters for endpoints used in T

- REX v 1.2.5 to determine terrestrial RQs.

.. 29 Table 9. Avian TREX upper

- bound dose

- based EECs (mg/kg)

................................ ................... 30
Table 10. Mammalian TREX dose

- based EECs (mg/kg).

................................ ............................ 31
Table 11. T

- REX dietary based EECs.

................................ ................................ ........................ 31
Table 12. Estimated LD 50 

### /ft 2 

### (in mg active ingredient (a.i.) per square foot) from granular applications of ethalfluralin across uses.

................................ ................................ ...................... 32
Table 13. TerrPlant EECs (lbs. a.i./A) for ethalfluralin exposure to terrestrial and wetland plants resulting from runoff and spray drift.

................................ ................................ ........................... 33
Table 14 . Ethalfluralin contact and oral estimated exposure dose concentrations to honeybees. 36 Table 15. Input parameters for KABAM mo del.

................................ ................................ ......... 36 Table 16. Estimated concentrations of ethalfluralin in ecosystem components.

.......................... 37 Table 17. Summary of Acute and Chronic Toxicity Data for Aquatic Taxa Exposed to
Ethalfluralin.

................................ ................................ ................................ ................................ . 39 Table 18. Summary of Toxicity for Terrestrial Taxa Exposed to Ethalfluralin.

........................... 42
Table 19 . Summary of Ecological Incidents as found in EIIS from the Usage of Ethalfluralin (Note: In every incident, the taxa affected were terrestrial plants).

................................ .............. 45 Table 20. Risk presumptions for terrestrial animals based on risk quotients (RQ) and levels of concern (LOC).

................................ ................................ ................................ ............................. 55 Table 21. Acute RQs for fish and aquatic invertebrates exposed to ethalfluralin.

....................... 56 Table 22. Chronic RQs for fish and aquatic invertebrates exposed to ethalfluralin.

................... 56
Table 23. Porewater

- based RQs for freshwater sediment

- dwelling invertebrates.

..................... 57 Table 24. Organic carbon normalized sediment based RQs for freshwater sediment dwelling
invertebrates.

................................ ................................ ................................ ................................ . 57 Table 25. RQs for non

- vascular and vascular aquatic plants exposed to ethalfluralin.

................ 58
Table 26. Chronic dose

- based RQs for mammals exposed to proposed spray uses of ethalfluralin.

................................ ................................ ................................ ................................ ....................... 59 Table 27. Monocot RQs from applications of ethalfluralin in the modeled scenarios of Run off and Spray Drift in Dry areas, Runoff and Spray Drift in Semi

- Aquatic Areas, and Spray Drift only.

................................ ................................ ................................ ................................ .............. 60 Table 28. Dicot RQs from applications of ethalfluralin in the modeled scenarios of Runoff and Spray Drift in Dry areas, Runoff and Spray Drift in Semi

- Aquatic Areas, and Spray Drift only. 62

### 5 Table 29. Contact RQs for bees that result from applications of ethalfluralin.

............................ 64 Table 30. Buffer distances for aquatic taxa using very fine to fine droplet sizes.

........................ 65 Table 31. Buffer distances for aquatic taxa using fine to medium coarse droplet sizes.

.............. 65 Table 32. Buffer distances from spray applications with very fine to fine droplet sizes.

............. 67
Table 33. Buffer distanc es from spray applications with fine to medium/coarse droplet sizes.

... 67 Table 34. Modeled spray drift buffer distances needed to mitigate risk to the most sensitive monocot species for applications with very fine to fine droplet size spectrum (ground applications).

................................ ................................ ................................ ................................ . 70 Table 35. Modeled spray drift buffer distances needed to mitigate risk to the most sensitive dicot species for applications with very fine to fine droplet size spectrum (ground applications)

........ 70 Table 36. Modeled spray drift buffer distances needed to mitigate risk to the most sensitive monocot species for applications with fine to medium coarse droplet sizes (ground applica tions).

................................ ................................ ................................ ................................ ....................... 71
Table 37. Modeled spray drift buffer distances needed to mitigate risk to the most sensitive dicot species for applic ations with fine to medium coarse droplet sizes (ground applications).

.. 71 Table 38. Summary of adverse impacts for aquatic organisms expected from the existing uses of
ethalfluralin.

................................ ................................ ................................ ................................ .. 79 Table 39. Summary of adverse impacts for terrestrial organisms exp ected from the existing uses
of ethalfluralin.

................................ ................................ ................................ .............................. 81

### 6 

## Table of Figure s

Figure 1. USGS estimate agricultural use for ethalfluralin in the US 2012 map (top figure) and
1992

- 2013 national summary (bottom figure).

................................ ................................ ............. 17

### 7 

## 1. Executive Summary

Scope and Rationale for Registration Review Risk Assessment

This document contains the environmental fate and ecological risk assessment for the registered
uses of the chemical ethalfluralin

. Ethalfluralin is a member of the dinitroaniline class of
herbicides that inhibit s the formation of the cell wall in plants (both aquatic and terrestrial) and by initiating desiccation of the xylem and phloem systems in plants.

Ethalfluralin Current Registered Uses

Ethalfluralin is soil incorporated (mechanically or by wetting in) and used on alfalfa, clover, dill, bean (dry), cucurbits, lentils, mustard, oilseed (sunflower, jojoba etc

. ), oilseed (crambe, rapeseed), oilseed sunflower, peanuts, peas (dry), potatoes and soybeans. Both flowable and granular formulations are registered for various crops. Also depending on the crop site, ethalfluralin may be applied pre

- emergence, post

- emergence, or in the fall during fallow periods. The maximum label rates for the various crop si tes ra nge from about 0.75 to 1.69 pounds of active ingredient (a.i.) per acre.

Environmental Fate and Exposure Summary

Ethalfluralin residues have the ability to reach nearby water bodies in sediment borne in runoff or in a dissolved state via spray drift or runoff. Exposure modeling indicates that under most use conditions aquatic exposure is primarily from spray drift at the time of application and that transport via runoff is primarily (but not exclusively) in soil

- bound residues (erosion) rather than dissolved phase. This is consistent with ethalfluralin’s relatively high soil organic carbon

– water partition coefficient (K foc 

### range of 3967

- 8083 mL/g ).

The environmental persistence of ethalfluralin varies signifi cantly with the different transformation pathways that are available after application. Most of the chemical that reach es the soil system will be transformed within 2 months based on the aerobic soil biotransformation
with half

- lives ranging from 17 to 46 days. Ethalf luralin transformation in soil sediment is relatively rapid with an anaerobic aquatic half

- life of 1.6 days (single test). If sunlight is present ethalfluralin transformation can be quite rapid ( aquatic photodegradation half

- life value of 6.3
h ours). This may greatly accelerate the degradation of any dissolved residues present in clear surface waters but the effect of photolysis on most aquatic systems is not expected to be significant due to turbidity and light attenuation in most water bodies. Volatilization can be a significant mechanism of dissipation (vapor pressure of 8.2 x 10

- 5 

### mm Hg at 25°C is indicative of this) and degradation in the atmosphere within a few h ours or days is predicted

.

Ecological Effects Summary and Risk Conclusions

### 8 When estimates of ethalfluralin exposure in terrestrial and aquatic environments are compared to the available ecotoxicity data, the results indicate a potential for risk above the level of concern to both aquatic and terrestrial taxa from pro posed uses of ethalfluralin

. Aquatic taxa were determined to be at risk from both acute and chronic exposure while terrestrial animals were at risk from chronical exposure.

Ethalfluralin is very highly toxic to aquatic animals on an acute exposure basi s . In general, risk quotients (RQ) for aquatic organisms are calculated considering estimated exposure concentration (EEC) in the surface water column for each crop. Acute r isk concerns exist for federally listed threatened/ endangered (hereafter referred to as “listed”) freshwater fish and invertebrates (RQs 0.06

– 0.39) and estuarine / marine fish and invertebrates at the highest application rates (RQs 0.05

- 0.07). Chronic risk concerns exist for listed and non

- listed freshwater fish from multiple applicat ion rates (RQs 1.0 to 3.4) and to estuarine/marine fish at the highest application rate (RQ = 1.13) but not to aquatic invertebrates. Sediment

- dwelling freshwater invertebrates were also determined to be at risk from chronic exposure to residues in
sedime nt (RQs 1.3

- 4.0). Risk was identified to non

- listed aquatic vascular plants only at the highest application rates (RQ = 1.7). Risk to listed vascular plants was identified for several application rates ranging from 1 to 1.7 lbs ai/A with RQs from 3 to 10 .4. Risk to listed non

vascular plants was only identified at the highest application rate of 1.7 lbs ai/A (RQ = 1.1).

For terrestrial wildlife, ethalfluralin is practically non

- toxic to birds, mammals, and terrestrial
insects on an acute exposure basis. E thalfluralin i s classified as practically non

- toxic to honey
bee adult s on an acute contact exposure basis. How ethalfluralin impacts of adults bees from chronic exposure or larval bees from acute or chronic exposure remain uncertain. Additional studies addressing the pollinator data gaps for chronic adult exposure and acute and chronic larval exposure would help reduce this uncertainty.

No risk i s identified for either non

- listed or listed birds , reptiles , or terrestrial

- phase amphib ians

, from acute or chronic exposure to ethalfluralin. Chronic risk to mammals i s identified for uses involving spray applications (RQs range from 0.01 to 3.3). RQs for small

- and medium

- sized mammals (15 g and 35 g mammals respectively) exceed the chroni c risk LOC of 1.0 for those animals foraging on short grass, tall grass, broadleaf plants fo llowing uses on alfalfa, cucurbits, potatoes and sunflower with application rates at 1 to 1. 6 9 lbs a.i./A. Modelling suggests there may be potential chronic risk to mammals from consuming fish containing residues that have accumulated through trophic transfer with one LOC exceedance at the highest application rate (RQ 1.1).

Risk to t errestrial plant s was identified for every use of ethalfluralin (non

- listed and listed RQs ranging between <0.1

– 131), and both runoff and spray drift processes contribute to the overall
risk.

### 9 Data gaps to improve understand ing of ecological effects

The ecological d atabase for ethalfluralin has a number of outstanding data gaps as follows:

1. Whole sediment toxicity testing with an estuarine/marine sediment dwelling invertebrate ( Guideline 850.1735)
2. Tier 1 Acute oral toxicity to adult honeybees (Non

- guideline; OECD 21 3)
3. Tier 1 Acute oral toxicity to larval honeybees (Non

- guideline; OECD 237)

4. Tier 1 Chronic oral toxicity to adult honey bees (Non

- guideline)
5. Tier 1 Chronic oral toxicity to larval honey bees (Non

- guideline)

6. Tier 2 Pollinator feeding/semi

- field study

- The need for these studies is contingent upon
the results of lower tier bee studies (Non

- guideline)

7. Tier 2 P ollen and nectar residue studies

– The need for these studies is contingent upon
the results of lower tier bee studies (Non

- guideline)
8. Tier 2 Field test ing for pollinators

– The need for field testing is contingent upon the
results of lower tier bee studies (850.3040)



## 2. Mechanism of Action

Ethalfluralin is a member of the dinitroaniline class of herbicides which are selective herbicides mainly used in control of certain annual and broadleaf wee ds. Ethalfluralin functions by
i nhibiting the formation of the cell wall in plants (both aquatic and terrestrial) and by initiating desiccation of the xylem and phloem sys tems in plants. Specifically, they inhibit microtubule synthesis necessary in the formation of cell walls, but also vital for mitosis, as microtubules facilitate the process by ensuring correct positioning and orientation of the mitotic spindle
apparatus. Microtubules are also involved in the determination of cell division site based on the geometry and polarity of the cells. Dinitroaniline herbicides are absorbed somewhat by plant root systems, and to a greater extent by young seedling shoot organs suc h as the hypocotyl or coleoptile

. Little or no translocation of these herbicides occurs in plants (Parka and Sopa, 1977)

. Additionally, ethalfluralin has a registered label with another active ingredient, clomazone. The
formulation is used for control of broadleaf weeds in melons, pumpkins, squash, and watermelons. Clomazone acts by inhibiting carotenoid synthesis so that affecting plants are devoid of pigment, and therefore cannot photosynthesize.



## 3. Use Characterization

**3.1 Label**  **led Use**

### 10 Current labels ( Table 1 ) allow the usage of ethalfluralin on alfalfa, clover, dill, bean (dry), cucurbits, lentils, mustard, oilseed (sunflower, jojoba etc ), oilseed ( crambe, rapeseed), oilseed sunflower, peanuts, peas (dry), potatoes and soybeans. Depending on the crop

, ethalfluralin may be applied pre

- emergent, post

- emergent, or in the fall prior to a spring planting. More details on ethalfluralin maximum application rates and application methods are presented in Table 2 . The maximum application rates are specified as a single or crop

- cycle basis. Liquid formulat ions of
ethalfluralin are applied as a band/broadcast surface spray with ground equip ment or via chemigation applied through sprinklers. However, the granular formulation is applied to the soil surface with mechanical incorporation or incorporation through rainfall and/or sprinklers. Although not explicit on labels, it appears that applications are only made once per year / growing season (September 20 15 correspondence from Office of Pesticide Programs’ Biological and Economic Analysis Division; BEAD).

Table 1 . Summary of ethalfluralin product labels registration numbers.

Registrant Reg. No. 1 

### Use Sites and SLN ID, if applicable. 1 

### Dow AgroScience

- FIFRA Section 3 62719

- 184 (Granular)
62719

- 188 (EC) + SLNs (see below) 1. Dry beans 2. Dry peas
3. Oilseed

– Crambe, flax seed, rapeseed, etc

. 4. Oilseed

– Sunflower, etc

. 5. Oilseed

– Safflower

6. Peanut 7. Alfalfa, clover (SLNs = Special Local Needs
Labels ) 8. Lentils (SLNs)

Dow AgroScience Special Local Needs 62719

- 184 (Granular)
SLNs SLN

- MT

- 06

- 0003
1. Lentils

SLN

- ND

- 090004
1. Yellow Mustard

SLN

- ND

- 050010
1. Lentils

Dow AgroScience Special Local Needs 62719

- 188 (EC)
SLNs: SLN

- NV

- 950001 +
SLN

- ID

- 950020 +
SLN

- MT

- 01

- 0002 +
SLN

- WY

- 030005 +
SLN

- OR

- 940037 +
SLN

- WA

- 940018
1. Alfalfa for seed

### 11 Loveland
FIFRA Section 3 34704

- 610 (EC)
34704

- 836 (EC) OR

- 120002 SLN
WA

- 0900l3 SLN 1. Cucurbits group (Cucumbers, etc .)

Loveland Special Local Needs 34704

- 610 (EC) OR

- 120002 SLN
WA

- 0900l3 SLN
1. Dill

1 

### EC= E musifiable concentrate; SLN=special local needs

### 12 Table 2 . Summary of ethalfluralin application rates and methods by crop site.

Crop 1 Application Timing Single Application Rates (lbs a.i./A 2

Application Codes * Soil Type Specific

Rates Label Information

Maximum Range Variation max . rate with soil type, if applicable 3 Reg. No.

Alfalfa (ID, NV, WA

& WY, MT, OR) Pr e

- emergence 1.69 1.51

- 1.69 EC

- 1 (ID,MT); EC

- 2 (All); EC

- 3 (OR) C = 1.7, M = 1.5, F =
1.3 62719

- 188 (EC) 24c registrations

Germination 1.69 1.69 EC

- 2 (NV)

Established plantings 1.52 1.36

- 1.52 EC

- 2 (WA, WY); EC

- 3 (WA)
Late tillering 1.51 1.51 EC

- 1 (NV)

Beans (dry) Pre

- plant 1.69 1.13

- 1.69 EC

- 2, Gran

- F & Gran

- 2 F = 1.7, M = 1.5, C =
1.3 62719

- 184 and

- 188

Pre

- emergence 1.69 1.13

- 1.69 EC

- 3

Fall 1.70 1.13

- 1.69 Gran

- F

Clover (WY) Established plantings 1.50 1.13

– 1.50 EC

- 2 (WY) NA 62719

- 188 (EC) SLN

WY

- 30005

Cucurbits (Cucumber “CU”, Melons, Pumpkin & Squash “SQ” summer/ winter) Pre

- plant (CU, PM), At seeding (All), Pre

emergence (All) & Post

emergence (PM, SQ) 1.70 1.13

– 1.70

0.40

- 1.20 (w clomazone) EC

- 1 F = 1.7, M = 1.5, C =
1.1

F = 1.2, M = 0.8, C =
0.6 34704

- 610

34704

- 836

Dill (OR, WA)

Pre

- plant & Post

- plant 1.13 0.56

- 1.13 EC

- 1 (OR, WA) NA 34704

- 610 SLN's
OR

- 120002
WA

-- 090013

Lentils (MT & ND) Stubble (MT) Stubble (ND) 0.750
0.950 0.750
0.55

– 0.75 Gran

- 2 (MT & ND) F = NS, M = 0.75, C =
0.75 62719

- 184
24c

- MT

- 06

- 0003
24c

- ND

- 090004
24c

- ND

- 050010

### 13 Crop 1 Application Timing Single Application Rates (lbs a.i./A 2

Application Codes * Soil Type Specific

Rates Label Information

Maximum Range Variation max . rate with soil type, if applicable 3 Reg. No.

Mustard (ND) Stubble 0.95 0.550

- 0.950 Gran

- 2 (ND) 62719

- 184
24c

- ND

- 0 9 00 4

Oilseed

– Sunflower,

Jojoba, etc

. group 3 Spring (any time after Jan. 1), fall 1.7 0.550

– 1.70 Gran

- 2 & Gran

- F
EC

- 3
Gran

- F F = 1.7, M = 1.5, C =
1.3 62719

- 184 and

- 188

Oilseed

– Crambe, Rapeseed (canola),

etc . group 4 Except CA. Spring before planting or
fall 0.95
0.550

- 0.95 0 EC

- 2, Gran

- 2 & Gran

- F, Except CA F = 0.95, M = 0.75, C
= 0.55 62719

- 184 and

- 188

Oilseed

- Safflower Pre

- plant 1.15 0. 5 50

- 1.15 Gran

- 2 & Gran

- F F = 1.15, M = 0.95, C
= 0.75 62719

- 184 and

- 188

Peanuts Pre

- plant 1.15 0. 563

- 1.1 3 EC

- 2, Gran

- F & Gran

- 2 F = 1.1 3 , M = 0.

. 938

, C = 0.75 0 62719

- 184 and

- 188

Peas (dry) Except CA. Pre

- plant 0.750 0.750 EC

- 2, Gran

- F & Gran

- 2 Max. rate does not

vary. 62719

- 184 and

- 188

Fall 0.750 0.750 Gran

- F

Potatoes ** After planting but prior to

emergence 1.028 0.500

- 1.000 EC

- 2 & EC

- 3 F = 1.00 , M = 1.00 , C
= 0. 7 5 62719

- 188 only

Soybeans Pre

- plant 1.31 0.56

- 1.31 Gran

- 2 & Gran

- F F = 1.31, M = 1.13, C
= 0.75 62719

- 184 and

- 188

Fall 1.31 0.56

- 1.31 Gran

- F F = 1.31, M = 1.13, C
= 0.75 62719

- 184 and

- 188

* Application Codes:
EC: Applications with an emulsifiable concentrate (EC) formulation type (On Dow labels the EC is identified as an “HFP”, this appears to refer to the use of hexafluoropropylene copolymers in the formulation).
EC

- 1: Band/broadcast (not incorporated ) applied by l ow pressure ground sprayer

### 14 Crop 1 Application Timing Single Application Rates (lbs a.i./A 2

Application Codes * Soil Type Specific

Rates Label Information

Maximum Range Variation max . rate with soil type, if applicable 3 Reg. No.

EC

- 2: 3" Incorporated applied by s preader/incorporation equipment
G ran
- F: Impregnated with dry f ertilizers (3” Incorporated) applied by s preader/incorporation equipment
EC

- 3: Chemigation applied through s prinklers
G ran
- 2 = Granular formulation : r eq uires 2 separate incorporation steps, the first incorporation needs to occur within 48 hours after application. The label states to use incorporation equipment capable of thoroughly a nd uniformly mixing Son al an ® 10G into the top 2 to 3 inches of the final seedbed. Optional Methods of incorporation for s oybeans, d ry b eans and p eanuts on m edium and c oarse t extured s oils

. Sonalan ® l0G may be applied as a surface application and incorporated by rainfall or sprinkler irrigation.

** Potatoes: f or use in the States of AZ, CO, NE (West of Rt. 281), 10, KS (West of Rt. 281), MT, ND (West of Rt. 281), NV, NM, OK (West of Rt. 281/283), OR, SD (West of Rt. 281), TX (West of Rt. 281 and No rthwest of Rt. 377), UT, WA and WY. NA = Not applicable (no variation of rates with soil texture classification specified).

FOOTNOTES:

If local need or geographically restricted label

- States / regions where usage is currently permitted are listed in pa renthesis or in a footnote.

2 Maximum crop cycle / seasonal / annual application rates are generally not explicitly specified on the product labels. A maxi mum number of applications (1 in all

cases where specified) per season is sporadically specified wit h the uses on cucumber, melon, pumpkin, safflower, winter and summer squash. With the granular formulation the following limits are specified: Safflower = 1.15 lb ai / year. All other crops on Granular label (canola, crambe, dry beans, dry peas, peanuts, s oybeans, and sunflowers) = 1.4 lb ai / year. Presumably (but not explicitly specified on the label) in situations where a higher single application rate is specified ( e.g ., for dry beans and sunflowers) this takes

precedence over the 1.4 lb ai / year limi tation.

3 C = coarse textured soils, M = medium textured soils, and F = fine textured soils

GENERAL NOTES:
If local need or geographically restricted label

- States / regions where usage is currently permitted are listed in parenthesis or in a footnote. Maximum crop cycle / seasonal / annual application rates are generally not explicitly specified on the product labels. A maxi mum number of applications (1 in all

cases where specified) per season is sporadically specified with the uses on cucumber, melon, pumpkin, safflower, winter and summer squash. With the granular formulation the following limits are specified: Safflower = 1.15 lb ai / year. All other crops on Granular label (canola, crambe, dry beans, dry peas, peanuts, soybeans, and sunflowers) = 1.4 lb ai / year. Presumably (but not explicitly specified on the label) in situations where a higher single application rate is specified ( e.g ., for dry beans and sunflowers) this takes

precedence over the 1.4 lb ai / year limitation.

### 15 

## 3.2 **Usage**

In rece nt years, the use sites with ten percent or more of the crop treated (estim ated) have been: cucumbers, pumpkins, squash, dry beans/peas, peanuts, watermelons, and sunflowers according
to the s creening

- level use assessment (SLUA) provided by B EAD (see Table 3 ).The largest uses in terms of the estimated annual acres treated have been dry beans/peas followed by peanuts and
sunflowers.

Overall, the usage of ethalfluralin has been declining since 2002, according to estimates provided by the U.S. Geological Survey (see Figure 1 ). The most recent year estimate (using the “E Pest High” method the USGS considers the most conservative for calculating usage) in 2013 was about 1.5 million pounds applied nationally.

Table 3 . Screening Level Estimates of Agricultural Uses of
Ethalfluralin for 2004

- 2013.

Crops Average Annual Lbs. A.I. Applied Percent Crop Treated

Average Annual Maximum

Alfalfa 9,000 <1 <2.5

Beans, Green + 

### 6,000 5 25
Cabbage + 

### <500 <1 <2.5

Canola 4,000 <2.5 <2.5
Cantaloupes 5,000 5 15

Cucumbers 50,000 50 65
Dry Beans/Peas 600,000 25 40

Peanuts 200,000 25 40

Peas, Green + 

### <500 <1 <2.5
Peppers + 

### <500 <1 <2.5

Potatoes 2,000 <1 <2.5
Pumpkins 20,000 30 40
Soybeans 40,000 <1 <2.5
Squash 10,000 30 35

Sunflowers 200,000 10 20

Watermelons 20,000 20 35

TOTAL ca. 1,168, 000
(BEAD estimates, 6/11/2015 ; based on data sources reflecting usage over the period 2004

- 2013 )

### 16

### 17 “ Use by Year and Crop ” b ar c hart n ote: Order of crops in bars from top to bottom is: Other crops, pasture and hay, alfalfa, orchards and grapes, rice, vegetables and fruit, cotton, wheat, soybeans, and corn.

Source : https://water.usgs.gov/nawqa/pnsp/usage/maps/index.php

. Specific url: https://water.usgs.gov/nawqa/pnsp/usage/maps/show_map.php?year=2012&map=ETHALFLURALIN&hilo=H 

### Figure 1 . USGS estimate agricultural use for ethalfluralin in the US 2012 map (top figure)
and 1992

- 2013 national summary (bottom figure).



## 4. Exposure Characterization

**4.1 Environmental Fate and Transport Summary** 

This environmental fate and transport section addresses the environmental fate and transport properties of parent ethalfluralin. This assessment does not consider the environmental fate and transport properties of any of the numerous minor degradates formed from ethalfluralin degradation in the soil through microbial activity (further discussed below).

Etha l fluralin can be characterized as having low to moderate persistence varying with the environmental conditions and dominant transformation pathways pertaining to those conditions

. The environment al persistence varies from hours to months depending upon the transformation pathways that are available after application (always incorporated for all uses) . Most of the
chemical in the soil system will be transformed within 2 months based on the aerobic soil

### 18 biotransformation with half

- lives ranging from 17 to 46 days. Ethalfluralin transformation is relatively rapid with an anaerobic aquatic half

- life of 1.6 days (single test). If sunlight is present ethalfluralin transformation can be quite rapid ( aquat ic photodegradation half

- life value of 6.3 hours). This may greatly accelerate the degradation of any dissolved residues present in clear surface waters but the effect of photolysis on most aquatic systems is not expected to be significant due to turbidity an d light attenuation in most water bodies. Ethalfluralin is practically insoluble in water and is strongly bound to soil and sediment so the extent to which it is dissolved in the water column and susceptible to photolysis is likely limited

.

Ethalflurali n has a vapor pressure of 8.2 x 10

- 5 

### mm Hg at 25 ° C which is indicative of a potential for significant dissipation in the environment by volatilization ( Kennedy and Talbert , 1977)

. 1977 )

. V apor

- phase ethalfluralin is expected to degrade in the atmosphere by reaction with photo

chemically produced hydroxyl radicals and ozone molecules. The half

- life for this reaction in air with hydroxyl radicals is estimated to be 6 hours and the half

- life for this reaction with ozone is
estimated as 23 hours. 1 

### With the EPI (Estimation Programs Interface) Suite 2 

### AOPWIN function the hydroxyl radical reaction half

- life was estimated to be 1.9 hours and ozone reaction half

- life was estimated to be 22.9 hours. Therefore, chronic atmospheric exposure, or transport are precluded, a nd any concerns would likely be restricted to acute exposures. Ethalfluralin’s potential for volatilization may be reduced significantly because it adsorbs strongly to soils as well as to suspended solids, particulate, sediment, and organic matter in the water column.

Ethalfluralin will be mostly immobile in soil and bound to sediment in both terrestrial and aquatic environments ( Freundlich K ads 

### values of 12 to 97 mg/L, K foc 

### values of 3 957 to 8361 ml/g ). While ethalfluralin is not expected to contaminate ground water, it may reach ground water through its binding capacity to soil and soil particles and through erosion ( i.e. , runoff of
sediment

- bound residues) , and a very limited number of low level detections have been reported in ground water where ethalfluralin was included as an analyte . In surface waters, ethalfluralin is likely to be quickly and predominantly partitioned to sediments

, however no monitoring data are available for sediments. Ethalfluralin would be likely tho ugh be quickly degraded to less toxic compounds which would be tightly bound to sediment colloids and organic material

.

Ethalfluralin is stable to hydrolysis at pH values of 3, 6, and 9. Ethalfluralin, based on laboratory studies, is expected to be large ly b ou nd to soil particles and subject to aerobic or anaerobic metabolism. Field dissipation half

- lives ranged from 23 to 51 days and are similar to the laboratory metabolism half

- lives in aerobic soil. No degradates were analyzed for in any of these
stud ies since there were no major degradates in the environmental fate studies.

Adsorption is the highest in soils that are very rich in organic matter or clay content

. Higher application rates are recommended on the product labels for these types of soils a re consistent
with the more rapid loss of availab le active ethalfluralin parent.

1 See MRID 00094810 and http://toxnet.nlm.nih.gov/cgi

- bin/sis/search/a?dbs+hsdb:@term+@DOCNO+7545 (accessed on 1/10/2011).

2 Version 4.0, available at: http://www.epa.gov/oppt/exposure/pubs/episuitedl.htm

.

### 19 Both the aerobic and anaerobic degradation of ethalfluralin is complex with multiple pathways and products

, none of which have been found to substantially accumulate in the e nvironment.
Several minor (all were <10% of applied, usually much less) metabolites in soil have been detected in the laboratory studies 3 

### . Ethalfluralin is very similar structurally to trifluralin (a,a,a

trifluoro

- 2,6

- dinitro

- N,N

- dipropyl

- p

- toluidine) with the only difference in the molecules being in the nature of the alkyl substitutions of the amine moiety (N

- (2

- melhyl

- 2

- propenyl) for ethalfluralin versus N,N

- dipropyl for trifluralin. For the similar pesticide trifluralin, a very complex degradation patte rn has been established involving numerous minor degradation products 4



### .

See Appendix H for a summary of the ethalfluralin degradation pathway in aerobic and anaerobic soil). For example, in an aerobic metabolism study in three test soils ethalfluralin
de graded almost entirely to a multitude of minor degradation products in three test soils (MRID 48915601; study classified as supplemental). The most significant degradates detected in terms of the maximum percent of applied were:

M2 (ET

- 20) = 2,6

- Dinitro

- 4

- (trifluoromethyl)phenol (Up to 5.2% of applied ethalfluralin) M5 (ET

- 15M) = 2

- Methyl

- 7

- nitro

- 5

- (trifluoromethyl)benzimidazole (Up to 6.5% of applied ethalfluralin)

Unextracted residues increased over time to 51 to 65% in the 3 test soils, but the extraction scheme was sufficient to demonstrate that these residues were readily available and the corresponding accumulation of degradation products was indicative of exten sive transformation of parent trifluralin with the accumulation of such residues.

ET

- 4 = N2

- Ethyl

- N2

- (2

- methyl

- 2

- propenyl)

- 3

- nitro

- 5

- (trifluoromethyl)

- 1,2

- benzenediamine

ET

- 7 = N 2



### - Ethyl

- N 2



### - (2

- methyl

- 2

- propenyl

- 5

- (trifluoromethyl)

- 1,2,3

- benzenetriamine

In an anaerobic soil metabolism study (MRID 42930102) t wo major metabolites of ethalfluralin, formed by the reduction of one nitro group (ET

- 4) or both nitro groups (ET

- 7), were identified during the study : ET

- 4 reached a maximum of 31.0% of the applied r adiocarbon or 0.04 ppm in
the d ay 0 samples, but was not detectable after d ay 1. ET

- 7 reached a maxi m um of 32.0% of the applied radiocarbon at Day 1, but was not detectable after day 1

. These are not considered to be major metabolites because they form alm ost instantly under anaerobic conditions and further transformation takes place rapidly. Multiple strong extraction systems failed to remove most of the applied radioactivity with time

– at study conclusion after 6 months of incubation 86 to 94% of the app lied radioactivity remained bound to the soil.

Ethalfluralin has some characteristics which indicate it should be considered for bioaccumulation potential, such as a relatively high log octanol

- water partition coeffi ci ent (log K ow 

### ) of 5.11 and significant bioaccumulation in fish ; however, the compound is also subject to relatively rapid depuration half

- life of 3 days ( Table 3 ). In a study with radio

- labeled etha l fluralin, bluegill

3 In the aerobic metabolism study all degradates were present at 3% or less during the entire course of the 9

- month study. See Appendix for structures of the metabolites and a degradation pathway proposed by the registrant.

4 Grover, R.; Wolt, J.D.; Cessna, A .J; Schiefer H.B. 1997. Environmental fate of trifluralin. Rev Environ Contam
Toxicol. 153:1

- 64.

### 20 sunfish ( Lepomis macrochirus ) had measured bioconcentrat ion factors (BCF) r anging from 1040 to 1560X; however, when exposure stopped, half of the compound was depurated after 3 days (MRID 41994902)

.

In the Environmental Fate and Ecological Risk Assessment Problem Formulation in Support of Registration Review of Ethalfluralin ( DP Barcode D382172, 3/14/2011) and the Reregistration Eligibility Decision (RED) document (EPA 738

- R

- 95

- 001, March 1995) the only residue of
concern in animals and plants w as determined to be the parent ethalfluralin . H owever, the RED
recommended an additi onal study of cucurbits to verify whether the parent alone should be considered in setting tolerances.

Table 4 . Summary of Physicochemical Properties of Ethalfluralin.

Parameter Value and Unit Source Chemical Structure

Chemical N ame N

- ethyl

- ∀∀∀

- trifluoro

- N

- (2

- methylallyl)

- 2,6

- dinitro

- p

- toluidine
OR

N

- ethyl

- N

- (2

- melhyl

- 2

- propenyl)

- 2,6

- dinitro

4

- {trifluoromethyl)benzenamine .
Smiles Code CCN(CC(=C)C)C1=C(C=C(C=C1[N+](=O)[O

- ])C(F)(F)F)[N+](=O)[O

- ]
CAS Number 5528

- 68

- 6

PC Code 113101
Empirical Formula C 13 H 14 F 3 N 3 O 4 Product Chemistry data
Molecular Weight 333.27 g Product Chemistry data
Appearance crystalline Product Chemistry data

Color Yellow Product Chemistry data

Odor faint amine

- odor Product Chemistry data
Melting Point 57

– 59 o C Product Chemistry data
Vapor pressure (25 o C) 8.2 x 10

- 5 mm Hg (torr) Product Chemistry data
Water Solubility (pH 7, 20 o C) 0.3 mg/L Product Chemistry data
Henry’s law constant (K H ) 1.2 x 10

- 4 atm M 3 /mole Calculated from molecular weight and solubility

### 21 Log Octanol/Water Partition Coefficient (log K
ow ) (22 o C) 5.11 MRID 41890101

Log Octanol/ Air Partition Coefficient (log K
oa ) 7.39 Estimated with EPI S uite TM

4.11 a

Biomagnification Potential Presumption*: If log K OA > 5, log K OW >2
and the rate of chemical transformation is low, the chemical may bio

- magnify in
terrestrial food chains►

For ethalfluralin, the log K OW =5.11 easily meeting the criterion, but the rate of transformation in tissues of biota is relatively
fast. Therefore it cannot be confirmed that ethalfluralin has a potential to bio

- magnify in terrestrial food chains. In fish, ethalfluralin
did bioaccumulate (BCF range: 1040

– 1560X) but also rapidly depurated with a depuration half

- life of 3 days

, which sugg ests it may be metabolized in fish and excreted (MRID 41994902). ► Gobas et al. 2003 and Armitage & Gobas, 2007 5 support this presumption utilized here only as a broad reference to determine the potential for biomagnification in terrestrial
food webs and is based on slowly

- metabolized chemicals.

a http://www.epa.gov/tsca

- screening

- tools/download

- epi

- suitetm

- estimation

- program

- interface

- v411



### Summary of Fate Properties of Ethalfluralin.

PROPERTY VALUE DATA SOURCE COMMENTS

Hydrolysis Stable at pH 3,6, and
9 MRID # 000948

- 05

Henry ’s Law Constant 1.2 x 10

- 4 atm M 3 /mol One

- Liner Calculated value

Aqueous Photolysis
half

- life (days) 0.263 MRID 41613916 t 1⁄2 = 6.3 h ou rs

Soil Photolysis half

- life (days) 14.2 MRID 41613917 There was increased volatilization
of 14 C residues in dark vs. irradiated soil, study is supplemental.

Aerobic Soil
Metabolism
half

- life (days) , 25 o C 42.9

17.4

33.6

19.0
95% Upper C.I. mean = 48.5 days MRID 41613918

MRID 48915601 Half

- lives were normalized to 25

o C ( e .g

. , MRID 48915601 study
conducted at 20 o C.)

Anaerobic Soil
Metabolism
half

- life (days) 13.8 MRID 41613919

Aerobic Aquatic
Metabolism half

- life (days) No study submitted Previously waived; but at this time it is believed a study could add
value to the environmental fate knowledge base for ethalfluralin.

5 Gobas, F.A.P.C., B.C. Kelly and J.A. Arnot. 2003. Quantitative structure activity relationships for predicting the

bioaccumulation of POPs in terrestrial fo od webs. QSAR Comb. Sci. 22:329

- 336.

### 22 Anaerobic Aquatic
Metabolism half

- life (days) 1.58 MRID 42930102

Freundlich Adsorption Coefficient (K f ) Nueces Sand, 0.5%
O.M.: 11.9 (1/n = 0.956)
Fox Sandy Loam, 1.4%
O.M.: 32.6

(1/n = 0.954)
Crosby Loam, 1.8%
O.M.: 53. 0 (1/n = 0.963)
Brookston Clay Loam,
2.0% O.M.: 97.0

(1/n = 0.986) MRID 42437202 K oc values not calculated in study.

Organic Matter Partitioning Coefficient (K oc ) 3

, 95 7 ml/g
Range: 3957 to
8361 (K foc ) MRID 42437202 Additional data also available from European study for 4 soils 6

Terrestrial Field Dissipation
half

- life (days) , field
conditions 23 (silty clay loam, IL) 28 (sandy loam, GA) 51 (loam, CA) MRID :

41978101

000 94819
41441401
41613920
41978101

Fish Accumulation (BCF); concentration in tissue to exposure
concentration in water:
1330 X for whole fish,
1560 X for muscle, and
1040 X for the remainder (Wet weight). Depuration was rapid
with a removal half

life of 3 days after exposure ceased, MRID 41994902



### .



## 4.2 **Exposure Pathways**

Ethalfluralin p arent compound is considered to be the primary stressors for aquatic and terrestrial organisms in this risk assessment. Ethalfluralin degrades in soils and aquatic systems into minor degradation products (< 6 % each) and exposure to these degradation products may be considered
minimal. There is also evidence of significantly lower phytotoxicity of degradatio n products 7



### .

6 Additional data from E uropean U nion dossier Koc range 3967

- 8083 mL/g . See: http://sitem.herts.ac.uk/aeru/footprint/en/Reports/271.htm

. 7 James , E.H., , M

. S. Kemp and S

. R. Moss2 1995. Phytotoxicity of trifluoromethyl

- and methyl

- substituted dinitroaniline herbicides on resistant and susceptible populations of black

- grass (Alopecurus myosuroides). Pesticide
Science 43:273

– 277.

Elizabeth H. Ja mes1, Malcolm S. Kemp1 and Stephen R. Moss2,*

### 23 The following description of exposure pathways therefore places emphasis on the environmental fate of and exposure to parent ethalfluralin.

In surface waters, ethalfluralin is likely to be quickly and predominantly partitioned to sediments, however, the available monitoring studies all focus on dissolved concentrations of
ethalfluralin.

Adsorption is the highest in soils that are very rich in organic matter or clay content and

a bsorbed herbicide activity is very high. Therefore, higher application rates that are recommended on the product labels for these types of soils are consistent with the m ore rapid
loss of available active ethalflural in

.

Aquatic Exposure

Although e thalfluralin is not particularly mobile, it has potential to be transported to water bodies and aquatic habitats in both a dissolved state in runoff or in a sorbed state to erodible soil particles as well as by drift from spray applications

. Limnetic organisms (fish, aquatic invertebrates and plants) which occupy the water column may be exposed to etha l fluralin. Exposure is also expected to occur for benthic and sediment

- dwelling organisms given that
ethalfluralin readily partitions to sediment and organic matter given its measured K oc 

### in the range between 3957 and 836l mL/g.

The low to moderate persistence and strong sorption capacity of ethalfluralin in the environment lends itself to being available to runoff primarily via the process of erosion. This process is likely to be more significant if rain occurs shortly after application. Furthermore, off

- site spray drift deposition of ethalfluralin to water bodies nearby applications may also result in exposure
of aquatic organisms.

Terrestrial Exposure

• Dietary Exposure : D irect d ietary exposure to non

- target terrestrial organisms (birds and mammals) is possible with the application of ethalfluralin. Ethalfluralin is applied prior to and post emergence of crops ; insectivores and granivores may ingest food items possessing
the ethalfluralin residues

. D ietary exposure is also possible given the moderate persistence
of ethalfluralin in the terrestrial environment.

Furthermore, indirect dietary exposure may result from aquatic exposure to fish (discussed above). Therefore, p iscivorous birds and mammals feeding on contaminated fish may potentially be exposed. Bioaccumulation potential of ethalfluralin residues is po ssible in fish given ethalfluralin’s high Log K ow 

### value of 5.11. There is uncertainty in this route of exposure since there is relatively rapid metabolism/depuration in fish.

• Terrestrial plants: Exposure may occur via the runoff of residues off

- site f rom treated fields to adjacent lands covered with non

- targeted vegetation. Furthermore, off

- site deposition of ethalfluralin due to spray drift may also occur

.

### 24 • Terrestrial invertebrates: Dietary and contact exposure for terrestrial invertebrates are possible pathways with ethalfluralin applications.



## 4.3 **A quatic Exposure Analysis** 

Aquatic Exposure Estimation Modeling

Estimated exposure concentrations for aquatic animals and plants in surface waters for labeled
ethalfluralin applications are estimated using The Surface Water Concentration Calculator interface (SWCC ; version 1. 106 ; dated May 22, 2014 ). The SWCC is available on

- line at: http://www.epa.gov/pesticide

- science

- and

- assessing

- pesticide

- risks/models

- p esticide

- risk

assessment

. Primarily to test the predicted impact of simulation of volatilization on the exposure estimate, limited additional model runs were made with a replacement version of this model that was not officially adopted by EFED at the time of this assessment (the Pesticide Water
Calculator ), this can reduce the calculated EECs by up to 5% for ethalfluralin.

In this assessment, exposure estimates for each of the current uses represent the highest and most vulnerable exposure for ethalflura lin use sites across the country. For all of the agricultural crop uses, broadcast surface spray applications to bare ground with very shallow incorporation is evaluated since this is the conservative application scenario for runoff. For the FL cucumber scenario (which yielded the highest EECs of any modeled scenario) this assumption increases acute and chronic EEC estimates by 25 to 30% versus assuming a uniform incorporation to a 4 cm depth (See Appendix C.) However, estimated environmental concentrati ons (EECs) in the water column for aquatic habitat are mostly dominated by spray drift deposition directly in the receiving water body. T he fate parameters and use

- specific input parameters for the SWCC surface water modeling are shown in Table 5 and Table 6
, respectively . The EECs of
ethalfluralin in surface water are summarized in Table 7

. A more detailed EEC summary and
sele cted SWCC input / output files are provided in Appendix C. Model inputs were selected following the input parameter guidance found here: https://www.epa.gov/pesticide

- science

- and

assessing

- pesticide

- risks/guidance

- selecting

- input

- parameters

- modeling

.

Table 5 . Ethalfluralin physicochemical and fate property inputs for the SWCC model.

PROPERTY VALUE DATA SOURCE COMMENTS

Molecular Weight 333.27 Product Chemistry
Hydrolysis Stable MRID # 000948

- 05

Water Solubility (pH 7,
20 o C) 0.3 mg/L Product Chemistry
data Water Solubility (pH 7, 20oC)

Vapor pressure (25 o C) 8.2 x 10

- 5 mm Hg Product Chemistry
data Vapor pressure (25 C)

### 25 Aerobic Soil
Metabolism
half

- life (days) , 25 o C 95% Upper C.I. mean = 48.5 days MRID 41613918

MRID 48915601 Half

- lives were normalized to 25

o C ( e .g

. , MRID 48915601 study
conducted at 20 o C.) 95% C.I. due to uncertainty regarding
identification of all residues.

Aerobic Aquatic
Metabolism half

- life (days) 97 2 X the aerobic soil metabolism
half

- life input (per guidance when direct data are not available.)

Anaerobic Aquatic
Metabolism half

- life (days) 1.58 MRID 42930102

Organic Matter Partitioning Coefficient (K fo c ) 395 7 ml/g MRID 42437202 K oc value for sandy loam; lowest value among 4 soils 8 , used to provide a conservative estimate
of runoff.



### Table 6 . SWCC crop scenario and application

- related input parameter values for ethalfluralin aquatic exposure estimation

.

Use Represented Scenario IDs Application dates (for separate
simulations # of applications / year Application rate (kg ai /ha)

Soybeans IL Corn STD
KS Corn Std
MS corn STD
MS soybean STD

NC corn STD
OH Corn STD

PA corn STD June 10
June 25
October 10
October 25 1 1.47

Sunflower (conservative for other oilseed crops) ND Canola Std
KS corn Std 15

- May
10

- Jun
10

- Oct
25

- Oct 1 1.91

Cucurbits FL Cucumber Std October 15
October 30 1 1.91

Peanuts NC Peanut std October 10 1 1.29

Dry Beans (conservative for lentils) MI Dry beans Std October 25 1 1.89

Potatoes ID New Potato Std May 10 1 1.15

Alfalfa, Clover (conservative for dill) CA Alfalfa Std January 10 1 1.89

8 E uropean U nion dossier Koc range 3967

- 8083 mL/g . See: http://sitem.herts.ac.uk/aeru/footprint/en/Reports/271.htm

.

### 26 6 Spray drift fraction for aerial and ground applications from Table 2 of EPA, 2013, “Guidance on Modeling Offsite Deposition o f Pesticides via Spray Drift”.



### .

The maximum aquatic EECs (peak, 21

- day and 60

- day) by crop based on the SWCC farm pond
scenario are summarized in Table 7 (representing multiple scenarios and application dates tested, full results are provided in Appendix C . Benthic sediment concentrations were also
estimated with the peak and 21

- day concentra tions of 77.6 μg a.i . / L (parts per billion of dry
sediment ; ppb ) and 52.8 ppb , respectively

.

Table 7

. SWCC estimated upper

- bound peak, 21

- day and 60

- day concentrations in the surface water column
and sediment for ethalfluralin at the highest application rate for proposed crop uses.



### Crop Represented (Scenario ID) Concentration μg/L

Applic at

. Date Peak 21

- day 60

- day

Soybeans Oct. 10 6.51 2.6

--- (MS Corn)
Soybeans Oct. 25

--- --- 1.36 (MS Corn)

Sunflower+ Jun. 10 7.69 2.92 1.2 (KS Corn)

Cucurbits Oct. 30 12.5 3.55 1.36 (FL Cucumber)

Peanut May 1 4.12 1.37 0.57 (NC Peanut)
Dry Beans May 15 5.9 1.69 0.71 (MI Beans)

Potatoes May 10 5.9 1.69 0.71 (ID New Potato)

Alfalfa and Clover Jan. 10 5.81 2.09 0.96 (CA Alfalfa OP)



### Water Quality Monitoring Data

Due to its low overall usage profile and relatively low propensity to remain in the dissolved phase in surface waters

, there are relatively few detections of ethalfluralin almost all at sub ppb levels for surface waters and sub ppt levels for groundwater

. These data are provided for perspective, but the monitoring data are largely not associated with ethalfluralin usage profiles to
facilitate an understanding of the loadin gs associated with the monitoring data. These data cannot

### 27 be verified to provide an indication of the maximum aquatic exposure potential or the usage pattern associated with relatively high levels in water. In addition, monitoring for ethalfluralin
does no t provide a complete picture of ecological exposure potential because of the lack of monitoring associated with dissolved organic material or sediment.

Combined Water Quality Portal Data

A search of the National Water Quality Monitoring Council’s Water Quality Portal (WQP 9 

### ) was conducted on 1/21/2016

. The WQP includes data collected by over 400 state, federal, tribal, and local agencies a long with large previously separate databases associated with STORET, USGS National Water Quality Monitoring Program (NAWQA) and other important monitoring sources

. Out of a total of 31,637 samples (both surface and groundwater) analyzed for ethalfluralin there were 185 detections of ethalfluralin at concentrations between 0.01 and 0.768 ppb; there 3
detections above 0

. 1 ppb. Since none of these data verified a potential for ethalfluralin to occur in surface waters at concentrations greater than modeled, further detailed investigation of the nature of the available monitoring data was not conducted for this assessment.

USDA Pesticide Data Program

Drinking water monitoring data collected by USDA's Pesticide Data Program (PDP) are available for ethalfluralin for the years 2003 to 2 014 . During this time period, a total of 1,253 water samples
were collected none of which contain ed detectable residues of ethalfluralin.

NAWQA Surface Water Monitoring

The USGS NAWQA 10 

### data warehouse was searched on 12/23/2010 (the NAWQA data are now included in the WQP for which an updated search including NAWQA was conducted on 1/21/2016.) . Ethalfluralin was detected at concentrations between 0.00 5 and 0. 768 ug/L (ppb ) in 190 of 22,876 surface water samples (0.83% detection frequency) collected across the United
States 11 

### . The detection rate was higher in older samples

- 1.49% out of 2

, 006 stream water samples collected from 1992 to 2001 with a minimum detection limit of 0.00 5 pp b or less for all samples analyzed ; the higher rate could be because of higher use of ethalfluralin in the earlier time period and/or be due to differen ces in study area concentrations over the years.

The highest number of detections of ethalfluralin occurred in the following states (with 5 or mor e detections) :

• 113 in California

• 39 in Washington

• 16 in Colorado

• 15 in Idaho

9 WQP is a coopera tive service co sponsored by the United States Geolo gical Survey (USGS) and the Environmental Protection Agency (EPA),

10 http://infotrek.er.usgs.gov/nawqa_queries/swmaster/index.jsp (visited December 23, 2010)

11 The NAWQA long

- term monitoring program has focus areas across the US that change over time. There were an additional 26 detections below 5 ppt, but levels below 5 pp t would be undetectable if present in most samples because the practical minimum detection limit was at or near 5 ppt in most cases.

### 28 • 9 in North Dakota

There was a d efinite geographic concentration of the detections with the following watersheds /sites having the highest rate of detections: (1.) 77 detections at ORESTIMBA CR AT RIVER RD NR CROWS LANDING CA (Stanislaus Co., CA) (2.) 17 detections at SAN JOAQUIN R NR VERNALIS CA (San Joaquin Co., CA) (3.) 12 detections at ROCK CREEK AB HWY 30/93 XING AT TWIN FALLS ID (Twin Falls Co., ID) (4.) 11 detections at LONETREE CREEK NEAR GREELEY CO. (Weld Co., Colorado)

NAWQA Ground

- Water Monitoring

The USGS NAWQA data warehouse was searched on 1 2/23/2010 (also updated in a WQP search on 1/21/2016) . Ethalfluralin was detected at concentrations between 0.00 5 and 0.0 90 pp b in 3 of 8,528 ground

- water samples (0.035% detection frequency) collected across the United States. The sample which contained 0 .0 90 pp b ethalfluralin (from Franklin County, Washington) was the only sample with greater than 0.00 6 pp b ethalfluralin.



## 4.4 **Clean Water Act**

Ethalfluralin 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/ez_where.retrieval_list

.

In addition, no Total Maximum Daily Load (TMDL) has been developed fo r ethalfluralin , based on information provided

at http://iaspub.epa.gov/tmdl_waters10/attains_nation.tmdl_pollutant_detail?p_pollutant_group_i d=885&p_pollutant_group_name=PESTICIDES . More information on impaired water bodies
and TMDLs can be found at http://w ww.epa.gov/owow/tmdl/

.



## 4.5 **Terrestrial Exposure Analysis**

In order to estimate risks of ethalfluralin exposures in terrestrial environments, all exposure modeling and resulting risk conclusions will be based on maximum application rat es for a given use. Measures of exposure are based on terrestrial models that predict EECs of ethalfluralin

.

.

4.5.1 Terrestrial Animal (Birds (surrogates for reptiles and terrestrial

- phase amphibians) and Mammals) Dietary Exposure Estimation

Ethalfluralin may be applied as either a ground application using an emulsified co ncentrate or in granular form which will reduce exposure relative to foliar application. For ground applications
of emulsifiable concentra te, birds and mammals may be exposed to pesticide residues after

### 29 application through oral or dietary exposure to seeds or insects when foraging in the treated fields for nesting material or food. Therefore estimation of pesticide concentrations in wildlife
food items focuses on quantifying possible dietary ingestion of residues on vegetative matter and insects. The EFED terrestrial exposure model T

- REX (T

- REX, Version 1.5, released 03/2012) is used to estimate exposures and risks to avian and mammalian species. Input values for avian and mammalian toxicity as well as chemical application rates and foliar dissipation half

- life data are required to run the model. The model provides estimates of exposure concentrations and risk quotients (RQs). Specifically, the model p rovides estimates of concentrations (upper

- bound and mean) of chemical residues on the surface of different types of foliage and insects that may be dietary sources of exposure to avian, mammalian, reptilian, or terrestrial

- phase amphibian receptors. The surface residue concentration ( in mg ai/kg; parts per million; ppm) is estimated by multiplying the application rate (pounds active ingredient per acre) by a value specific to each food item. These values (termed the Hoerger

- Kenaga estimates) along with a more detailed discussion of the methodology implemented by T

- REX, are presented in Appendix E (T

- REX Model). By comparing EECs to acute and chronic toxicity reference values, RQs are calculated. The EECs on food items may be compared directly with dietary toxicity data or converted to an
oral dose. T he residue concentration is converted to daily oral dose based on the fraction o f body weight consumed daily as estimated through allometric relationships. The screening

- level risk assessment for ethalfluralin uses upper

- bound predicted residues as the measure of exposure. Consideration is given to different types of feeding strateg ies, including herbivores, insectivores and granivores. Dose

- based exposures are estimated for three weight classes of birds (20 g, 100 g, and 1000 g) and three weight classes of mammals (15 g, 35 g, and 1000 g). Summaries of the predicted upper

- bound res idues of ethalfluralin that may be expected to occur on selected avian or mammalian food items immediately following application for the maximum use scenario are presented in Tables 11, 12, and 13

.

4.5.2 Spray Applications

Input values for the endpoints used f or estimating avian and mammalian exposure risks to
ethalfluralin are summarized in Table 8

. For spray applications the default value for foliar half

life of 35 days was used for ethalfluralin residues on plants. The application rates and application methods are summarized above in Table 10 of the uses and consist of both spray applications and granular applications

.

Table 8

. Input parameters for endpoints used in T

- REX v 1.2.5 to determine terrestrial RQs.

Input Parameters Value Source

Avian Oral LD 50 > 2000 mg/kg

- bw (zebra finch) MRID 48915502

Avian Dietary 5000 ppm (bobwhite quail ) Acc. No. 070677

### 30 Avian Reproduction NOEAC 1000 ppm (mallard duck ) Acc. No 00094763

Mammal LD 50 5000 mg/kg

- bw (rat) Acc. No 00135189

Mammal NOAEC 61 mg/kg

- bw (rat) Acc. No 0094784 and

MRID 42300301



### For the maximum ethalfluralin application scenario of 1.69 lbs ai/A , concentrations for different
avian forage types ranged from 1 to 46 2 ppm for dose

- based upper

- bound residues ( Table 9 ) and

7 to 164 ppm for mean residues from emulsified concentrate applications. Mammalian dose

- based residues ranged from 1 to 387 ppm ( Table 10 ). Dietary residue concentrations ranged from and 15 to 406 ppm ( Table 11 ). EECs that resulted from granular applications ra nged from 1.2 to 2.11 mg ai ft

- 2 

### (Table 12)

.

Table 9

. Avian TREX upper
- bound dose

- based EECs (mg/kg)

. 20 g "Small" Bird 100 gram "Medium" Bird 1000 gram "Large" Bird

Use (application rate lbs a.i./A)Short GrassTall GrassBroadleaf PlantsFruits/podsArthropodsSeedsShort GrassTall GrassBroadleaf PlantsFruits/podsArthropodsSeedsShort GrassTall GrassBroadleaf PlantsFruits/podsArthropodsSeeds

Alfalfa with low broadcast spray (1.698) 462 212 260 29 181 6.4 263 121 148 16 103 3.7 118 54.1 66 7.4 46 1.6

Potatoes chemigation (1.028) 281 129 158 18 110 3.9 160 73 90.1 10 63 2.2 72 32.9 40 4.5 28 1

Sunflower (1.3) granular, incorporated, chemigation 355 163 200 22 139 4.9 203 93 114 13 79 2.8 91 41.6 51 5.7 36 1.3

### 31 Table 10 . Mammalian TREX dose

- based EECs (mg/kg).

15 gram "Small" Mammal 35 gram "Medium" Mammal 1000 gram "Large" Mammal

Use (application rate lbs a.i./A)Short GrassTall GrassBroadleaf PlantsFruits/podsArthropodsSeedsShort GrassTall GrassBroadleaf PlantsFruits/podsArthropodsSeedsShort GrassTall GrassBroadleaf PlantsFruits/podsArthropodsSeeds

Alfalfa with low broadcast spray (1.698) 387 177 218 24 151 5 267 122 150 17 105 4 62 28 35 4 24 1

Potatoes chemigation

(1.028) 235 108 132 15 92 3 163 75 91 10 64 2 38 17 21 2 15 1

Sunflower (1.3) granular, incorporated, chemigation 297 136 167 19 117 4 206 94 116 13 81 3 48 22 27 3 19 1



### Table 11

. T

- REX dietary based EECs.

Use (application rate lbs a.i./A)Short GrassTall GrassBroadleaf PlantsFruits/podsArthropods

Alfalfa with low broadcast spray (1.698) 406 186 228 25 159

Potatoes chemigation (1.028) 247 113 139 15 97

Sunflower (1.3) granular, incorporated, chemigation 312 143 176 20 122

### 32 4.5.3 Granular applications

For granular applications of ethalfluralin T

- REX (v. 1.5.2; 03/22/2012) is able to calculate the

LD 50 

### ft

- 2 

### risk index values for the labeled uses. The assumed incorporation of these methods of application is 85%. Thus 15% of the chemical is assumed to be available for consumption by
both avian and mammalian taxa. The LD 50 

### ft

- 2 

### value is calculated using a tox icity value (adjusted

LD 50 

### ) and the EEC (mg a.i. ft

- 2 

### ) and is directly compared with the Agency’s levels

- of

- concern (LOCs). As with EC formulations, consideration is given to differen t types of feeding strategies including herbivores, insectivores and gra nivores. Dose

- based exposures are estimated for three weight classes of birds (20 g, 100 g, and 1000 g) and three weight classes of mammals (15 g, 35 g, and 1000 g). The EECs that result from granular formulations is presented in Table 14

.

Table 12

. Estimated LD 50 

### /ft 2 

### (in mg active ingredient (a.i.) per square foot) from granular applications of ethalfluralin across uses

.

Use (application rate lbs a.i./A) mg a.i/ft 2

Clover 3" incorporated (1.35) 2.11

Lentils, mustard granular formulation incorporated (0.95) 1.48

Peanuts granular formulation (1.15) 1.8

Peas granular formulation (0.76) 1.2

Safflower granular 1.15) 1.8

Safflower incorporated (1.142) 1.78

Soybeans granular (1.33) 2

Sunflower (1.3) granular, incorporated, chemigation 2



### 4.5.4 Terrestrial Plant Exposure Estimation

The routes of exposure to terrestrial plants for ethalfluralin include o ff

- site trans port via spray
drift and runoff . The TerrPlant model (v. 1.2.2; December 26, 2006) evaluates terrestrial plant exposure contributions from runoff and s pray drift. It is used to derive EECs relevant to terrestrial and wetland plant s

. The model employs the assumption that default fractions of the intended application are transported to an adjacen t field through runoff and spray drift. There is not any drift assumed for granular applications and more accurate measures of off

- site drift is modeled using the AgDrift model. Measures of exposure to terrestrial plants are expressed as a

### 33 fraction of th e mass of the ethalfluralin applied to the treated field. TerrPlant EECs are shown in
Table 13 below.

Table 13

. TerrPlant EECs (lbs. a.i . / A) for ethalfluralin exposure to terrestrial and wetland plants resulting from runoff and spray drift.

Use (application rate

- lbs a.i./A) Description of Area EEC

(lbs a.i/A)

Alfalfa, Beans , Cucurbits with low broadcast spray EC1 (1.698) Runoff to dry areas 0.017

Runoff to semi

- aquatic areas 0.17

Spray drift 0.017

Total for dry areas 0.034

Total for semi

- aquatic areas 0.187

Alfalfa, Beans with chemigation EC3 (1.698) Runoff to dry areas 0.017

Runoff to semi

- aquatic areas 0.17

Spray drift 0.085

Total for dry areas 0.102

Total for semi

- aquatic areas 0.255

Beans granular (1.69) Runoff to dry areas 0.017

Runoff to semi

- aquatic areas 0.17

Spray drift 0

Total for dry areas 0.017

Total for semi

- aquatic areas 0.17

Clover 3" incorporated (1.5) Runoff to dry areas 0.005

Runoff to semi

- aquatic areas 0.05

Spray drift 0.015

Total for dry areas 0.02

Total for semi

- aquatic areas 0.065

Dill ground spray (1.13) Runoff to dry areas 0.015

Runoff to semi

- aquatic areas 0.15

Spray drift 0.015

Total for dry areas 0.03

Total for semi

- aquatic areas 0.165

Lentils, Mustard granular formulation 2" incorporation (0.95) Runoff to dry areas 0.00475

Runoff to semi

- aquatic areas 0.0475

Spray drift 0

Total for dry areas 0.00475

Total for semi

- aquatic areas 0.0475

Runoff to dry areas 0.0085

### 34 Use (application rate

- lbs a.i./A) Description of Area EEC

(lbs a.i/A)

Oilseed

- Sunflower, Jojoba, etc (1.7) Granular 2 inch incorporation Runoff to semi

- aquatic areas 0.085

Spray drift 0

Total for dry areas 0.0085

Total for semi

- aquatic areas 0.085

Oilseed

- Sunflower, Jojoba, etc (1.7) Granular F 3 inch incorporation Runoff to dry areas 0.005667

Runoff to semi

- aquatic areas 0.056667

Spray drift 0

Total for dry areas 0.005667

Total for semi

- aquatic areas 0.056667

Oilseed

- Sunflower, Jojoba, etc (1.7) EC3 chemigation Runoff to dry areas 0.017

Runoff to semi

- aquatic areas 0.17

Spray drift 0.085

Total for dry areas 0.102

Total for semi

- aquatic areas 0.255

Oilseed

– Crambe, Rapeseed (canola), etc . group

(0.95) EC2 spray with 2 inch incorporation Runoff to dry areas 0.00475

Runoff to semi

- aquatic areas 0.0475

Spray drift 0.0095

Total for dry areas 0.01425

Total for semi

- aquatic areas 0.057

Oilseed

– Crambe, Rapeseed (canola), etc . group (0.95) Granular with 2 inch incorporation Runoff to dry areas 0.00475

Runoff to semi

- aquatic areas 0.0475

Spray drift 0

Total for dry areas 0.00475

Total for semi

- aquatic areas 0.0475

Oilseed

- Safflower (1.15) granular with 2 inch incorporation Runoff to dry areas 0.00575

Runoff to semi

- aquatic areas 0.0575

Spray drift 0

Total for dry areas 0.00575

Total for semi

- aquatic areas 0.0575

Peanuts granular formulation (1.15) with 2 inch incorporation Runoff to dry areas 0.00575

Runoff to semi

- aquatic areas 0.0575

Spray drift 0

Total for dry areas 0.00575

Total for semi

- aquatic areas 0.0575

Peanuts EC with 2 inch incorporated (1.15) Runoff to dry areas 0.00575

Runoff to semi

- aquatic areas 0.0575

Spray drift 0.0115

### 35 Use (application rate

- lbs a.i./A) Description of Area EEC

(lbs a.i/A)

Total for dry areas 0.01725

Total for semi

- aquatic areas 0.069

Peas EC (0.75) 2 inch incorporation Runoff to dry areas 0.00375

Runoff to semi

- aquatic areas 0.0375

Spray drift 0.0075

Total for dry areas 0.01125

Total for semi

- aquatic areas 0.045

Peas granular formulation (0.75) 2 inch incorporation Runoff to dry areas 0.00375

Runoff to semi

- aquatic areas 0.0375

Spray drift 0

Total for dry areas 0.00375

Total for semi

- aquatic areas 0.0375

Potatoes chemigation (1.028) Runoff to dry areas 0.00514

Runoff to semi

- aquatic areas 0.0514

Spray drift 0.0514

Total for dry areas 0.05654

Total for semi

- aquatic areas 0.1028

Potatoes ground (1.028) Runoff to dry areas 0.00514

Runoff to semi

- aquatic areas 0.0514

Spray drift 0.01028

Total for dry areas 0.01542

Total for semi

- aquatic areas 0.06168

Soybeans Granular (1.3) 2 inch incorporation Runoff to dry areas 0.0065

Runoff to semi

- aquatic areas 0.065

Spray drift 0

Total for dry areas 0.0065

Total for semi

- aquatic areas 0.065



### 4.5.5 Terrestrial Invertebrate Exposure Estimation

Drift from the boom sprayers or residues may come into contact with pollinators either through
direct contact or ingestion of residues in pollen/nectar . Possible exposures from either acute contact or oral exposure to the proposed applications rates were calculated using Bee

- Rex model (version 1.0)

. To calculate contact exposure, the application rate was multiplied by 2.7 μg a.i

. / bee. Oral exposure was calculated by multiplying the application rate by ((110 μg a.i . / g) * 0.292g/day)). For details see t he Guidance for Assessing Pesticide Risks to Bees ( USEPA,

### 36 2014). Estimated dose exposure concentrations for honeybee ( Apis mellifera ) contact and oral

exposure are presented in Table 1 4 resulting from each representative ethalfluralin use s

.

Table 14 . Ethalfluralin contact and oral estimated exposure dose concentrations to honeybees. Use (Application Rate

- lbs a.i./A) Contact Exposure (mg/kg) Oral Exposure (mg/kg)
Alfalfa with low broadcast spray (1.698) 4.5 54.5

Potatoes chemigation (1.028) 2.8 33

Sunflower (1.3) granular, incorporated, chemigation 3.5 41.8



### 4.5.6 Picivorous Avian and Mammal exposure to fish containing ethalfluralin residues

The KABAM model (K ow 

### (based) Aquatic BioAccumulation Model ; version 1.0 ) was used to evaluate the potential exposure and risk of direct effects to birds and mammals via bioaccumulation and biomagnification in aquatic food webs. KABAM is used to estimate potential bioaccumulation of hydrophobic organic pesticides in freshwater aquatic ecosystems and risks to mammals and birds consuming aquatic organisms which have bioaccumulated these pesticides. The bioaccumulation portion of KABAM is based upon work by Arnot and Gobas (2004) who parameterized a bioaccumulation model based on polychlorinated biphenyls ( PCBs ) and some pesticides ( e.g ., lindane, DDT) in freshwater aquatic ecosystems (Arnot and Gobas, 2004) . KABAM relies on a chemical's K ow 

### to estimate uptake and elimination constants through respiration and diet of organisms in different trophic levels. Pesticide tissue residues are calculated for different levels of an aquatic food web. The model then uses pesticide tissue concentrations in aquatic animals to estimate dose

- and dietary

- based exposures and associated
risks to mammals and birds (surrogate for amphibians and reptiles) consuming aquatic organisms. Seven different trophic levels including phytoplankton, zooplankton, benthic invertebrates, filter feeders, small

- sized (juvenile) forage fish, medium

- sized forage fish , and larger piscivorous fish, are used to represent an aquatic food web. Importantly, chemical metabolism by biota is assumed to be zero in KABAM so modeling will indicate worse case scenarios of exposure . Input scenarios and parameters were chosen to re present the range of exposures from high to low and are presented in Table 1 5

. Example output from the bioaccumulation model is provided in Appendix F

.

Table 15 . Input parameters for KABAM model.

Parameter Input Value Source

Pesticide Name Ethalfluralin

Log K OW 5.11 MRID 41890101

K OC 395 7

- 8391 L/kg O.C. MRID 42437 2 02

### 37 Parameter Input Value Source

Use patterns Acute Concentration in water column(ppb) Acute Concentration in pore water (ppb)

Cucurbits (1.7 lb a.i./A) 12.5 0.49

Soybean (1.3 lb a.i./A) 6 0.19



### Based on KABAM results and no depuration , estimated concentrations of ethalfluralin residues
in the tissue of organisms in the different trophic levels following application on cucurbits range from 72,690 μ g/kg to 174,190 μg/kg ( Table 16 )

. The measured bioconcentration factors (BCF’s) in the laboratory were 1330 L/Kg in the whole fish (MRID 41994902) while the KABAM model estimated a BCF for large fish of 6191. This suggests that KABAM may
overestimate the bioaccumulation of ethalfluralin and therefor e overestimate the risk from consumption of fish from contaminated water bodies. One reason for this discrepancy between measured and predicted values may be that e thalfluralin is able to rapidly depurate in fish tis sues (3 days) and the KABAM mode ls assumes no depuration. So while the Kow indicates that ethalfluralin has a strong tendency to bioaccumulate and this is a possible route of exposure, it is likely that the exposure modeled by KABAM represents a worst case scenario

.

Table 16 . Estimated concentrations of e thalfluralin in ecosystem components.

Ecosystem Component Total
concentration

(μg/kg

- ww) Lipid
normalized
concentration (μg/kg

- lipid) Contribution
due to diet (μg/kg

- ww) Contribution

due to respiration (μg/kg

- ww)

Phytoplankton 72,690 3634482 N/A 72,689.64

Zooplankton 56,920 1897330 2,222.15 54,697.75

Benthic
Invertebrates 61,641 2054701 5,607.68 56,033.37

Filter Feeders 40,471 2023530 3,612.90 36,857.70

Small Fish 94,288 2357210 24,355.55 69,932.85

Medium Fish 115,675 2891869 48,653.60 67,021.15

Large Fish 174,190 4354746 107,805.01 66,384.81



## 5 Ecological Effects Characterization

Th is section contains the ecological effects characterization for ethalfluralin based upon registrant

submitted toxicity data for the technical grade active ingredient ( TGAI ; parent ethalfluralin ) and for specified formulations. Ethalf l uralin is characterized as being very highly toxic to freshwater and estuarine/marine fish, aquatic

- phase amphibians (for which freshwater fish serve as surrogates), and to freshwater invertebrates on an acute exposure basis. The compound is highly toxic to estuarine/marine invertebrates on an acute exposure basis. Chronic exposure resulted in

### 38 r eductions in growth in fish and freshwater invertebrates and reduced reproduction in
estuarine/marine invertebrates.



## 5.5 **Aquatic Effects Summary** 

The effects of exposure to e thalfluralin on aquatic organisms were determined by assessing
freshwater and estuari ne/marine taxa

. The most sensitive species that are used to assess risk in
this assessment are listed in Table 18 . Additionally, five chronic animal toxicity studies and one aquatic vascular plant toxicity study were submitted since the last assessment :

1) a chronic toxicity test with the sheepshead minnow ( Cyprinodon variegatus ; MRID
48689101 ) ; 2) a chronic toxicity test with the freshwater daphnid ( Daphnia magna ; MRID 49086902) ; 3) a chronic toxicity test with the estuarine mysid shr imp ( Americamysis bahia ; MRID
49037801 ) ; 4) a 10

- day toxicity tests with the freshwater benthic invertebrate midge Chironomus dilutus (MRID 48975701) ; 5) a 10

- day toxicity tests with the freshwater benthic invertebrate amphipod ( Hyalella

a zteca; MRID 48975702) ; and, 6) a t oxicity test wit h the vascular aquatic plant duckweed ( Lemna gibba ; MIRD 49086901)

.

These studies are marked in bold in Table 17 of the aquatic taxa endpoints . Only descriptions of these studies are provided below. Refer to previous assessments , (DP# D205884, D296985, and D296987) for more comprehensive descriptions of the studies that are not included here.

Chronic Toxicity to Sheepshead minnow (Cy p rinodon variegatus ) (MRID 48689101)

The 33

- day chronic toxicity of ethalfluralin to the early life

- stage (ELS) of estuarine/marine sheepshead minnow was studied under flow

- through conditions (MRID 48689101) . The overall NOAEC and LOAEC was 1.2 and 2.7 μg ai/L respectively, based upon the 4% reduction in total length at the 2.7 μg ai/L levels. This study is classifie d as scientifically sound and satisfies the guideline requirements for an early life stage toxicity study with fish.

Chronic Toxicity to the Freshwater Invertebrate ( Daphnia magna ) (MRID 49086902)

The 21

- day

- chronic toxicity of ethalfluralin to Daphnia was studied under flow

- through
conditions (MRID 49086902) . The NOAEC and LOAEC were 71 and 150 μg ai/L, respectively, based upon a treatment

- related reduction in both total body length (2% decrease) and dry weight (13% decrease ) at the 150 μg ai/L level.

Chronic Toxicity to the Saltwater Mysid ( Americamysis bahia) (MRID 48936801)

A 28

- day life cycle toxicity test of ethalfluralin to mysids was studied under flow

- t hrough conditions (MRID 48936801)

. The NOA EC and LOAEC were 29

. 1 and 57

. 8 μ g a.i . / L

### 39 respectively based on a 32.4% reduction in young produced per female . This study is classified as acceptable.

Chronic Toxicity to the Midge ( Chironomus dilutus ) (MRID 48915701)

A 10

- day chronic toxicity test of ethalfluralin (MRID 48915701) was performed with the
freshwater benthic invertebrate midge using s piked sediment

. No treatment

- related effects were observed on survival or growth following 10 days of exposure. The NOAEC and LOAEC for the endpoints no rmalized to organic carbon were 4800 and > 4800 mg ai/kg total organic carbon ( TOC ) or 27 0 μ g a.i . / L and >27 0 μ g a.i . / L for po re water . This study was classified as acceptable.

Chronic Toxicity to the Freshwater Amphipod ( Hyalella azteca ) (MRID 48915702 )

A 10

- day chronic toxicity test of ethalfluralin ( MRID 48915702) was performed with the
freshwater benthic invertebrate amphipod using spiked sediment . Using mean

- measured concentrations, the NOAEC and LOAEC for growth were 10 and 19 mg ai/kg (92 and 140 μ g a.i

. / L pore water ) , respectively , based on a 20% reduction in dry weight . The OC

- normalized mean
measured sediment concentration NOAEC and LOAEC endpoints are 480 and 900 mg ai/kg
TOC respectively

.

Acute Toxicity of Ethalfluralin to Aquatic Vascular Plants ( Lemna gibba ) (MRID 49086901)

In a 7

- day acute toxicity study, the freshwater duckweed w as exposed to e thalfluralin under
static renewal conditions (MRID 49086901) . The initial mean measured concentrations were 0 (negative and solvent co ntrols), 0.36, 1.7, 5.2, 18, 70, and 220 μ g ai/L. The NOAEC value based

on reductions in frond number yield and frond number growth rate was 1.7 μ g ai/L and based on final biomass and biomass growth rate was 5.2 μ g ai/L. The EC 50 

### /IC 50 

### values based on fro nd number yield, frond number growth rate, final biomass, and biomass growth rate were 7.322, 29.1, 36.77, and >220 μ g ai/L, respectively, in terms of initial measured concentrations.

Table 17

. Summary of Acute and Chronic Toxicity Data for Aquatic Taxa Exposed to
Ethalfluralin.

Exposure
Scenario Species Scientific

Name Exposure
Duration Toxicity
Reference

Value ( μg a.i./L ) Endpoints
Affected Reference

(Classification)

Freshwater Fish

Acute Bluegill
Sunfish Lepomis
macrochirus 96 hours LC 50 = 32 Mortality Acc.

No. 00135183
Very Highly
Toxic

(Acceptable)

Acute Rainbow

Trout Oncorhynch us mykiss 96 hours LC 50 = 37 Mortality Acc. No.
00135183 Very Highly
Toxic (Acceptable)

### 40 Chronic Rainbow

Trout Oncorhynch us mykiss 60 day NOAEC/
LOAEC =

0.4/1.4 Larval survival, length, weight MRID
41994901

(Acceptable)

Freshwater Invertebrate

Acute Waterflea Daphnia

magna 96 hours LC 50 =60 Mortality Acc. No. 070677 Very highly toxic (Acceptable)

Chronic * Waterflea Daphnia

magna 21 days NOAEC/
LOAEC =24/
37 Growth MRID
42930101 (Acceptable)

Chronic Waterflea Daphnia

magna 21 days NOAEC/
LOAEC =71/
150 Growth MRID
49086902 (Acceptable)

Estuarine Fish

Acute Sheepshead
Minnow Cyprinodon variegatus 96 hours LC 50 =240 Mortality MRID 41613904, Highly Toxic (Acceptable)

Chronic Sheepshead
Minnow Cyprinodon variegatus 33 days (ELS) NOAEC/
LOAEC = 1.2
/ 2.7 L ength MRID
48689101

(Acceptable)

Estuarine Invertebrates

Acute Mysid Shrimp Mysidopsis
bahia 96 hours LC 50 =23 0 Mortality MRID
41613906

Highly Toxic

(Acceptable)

Acute Eastern Oyster Crassotrea virginica 96 hours LC 50 =17 0 Mortality MRID
42889801

Highly Toxic

(Acceptable)

Chronic Mysid Shrimp Mysidopsis
bahia 28 days NOAEC/
LOAEC =
29

. 1/ 57. 8 Offspring produced per fema le MRID
49037801

(Acceptable)

Aquatic Plants

Non

Vascular Green Algae Pseudokirchne
riella swubcapitata

formerly
Selenastrum capricornutum 120 hours I C 50 = 2 5

Cell Density MRID
41613912

NOAEC= 10.9 (Acceptable)

Vascular Duckweed Lemna gibba 14 days I C 50 = 7.3 MRID
49086901

### 41 NOAEC=1.7 Frond
number

yield (Acceptable)

Sediment Invertebrates

Chronic Midge Chironomus
dilutus 10 day NOAEC/
LOAEC = 27 0,

> 27 0 NA MRID
48975701 Acceptable

Chronic Amphipods Hyalella

azteca 10 day NOAEC/
LOAEC
=92/ 14 0 Dry weight MRID
48975702 Acceptable

*When two studies are presented, the most sensitive endpoint will be used for risk assessment purposes.



## 5.6 **Terrestrial Effects Summary**

Ethalf l uralin is practically non

- toxic to both mammals and birds, reptiles and terrestrial

- phase amphibians (for which birds serve as surrogates) on an acute oral exposure basis; the compound
is also practically non

- toxic to birds on a subacute dietary exposure basis. Ethalf l uralin is also practically non

- toxic to young adult honey bees ( Apis mellifera ) on an acute contact exposure basis. Chronic exposure in both birds and mammals resulted in effects on reproduction.

The effects of e thalfluralin on terrestrial organisms that are used to assess risk in this a ssessment are listed in Table 18 . Additionally, four new studies were submitted since the last assessment
that include :

1) a n acute toxicity stu dy with Japanese q uail ( Coturnix japonica ; MRID 48915501) ; 2) a n acute toxicity study with Zebra f inch ( Taeniopygia guttata ; MRID 49385904) ; 3) a vegetative vigor study with the formulated product Sonalan ® 

### HP (GF

- 1740)

– 35.1%
Ethalfluralin (MRID 48915901) ; and

, 4) a seedling emergence study with the formulated product Sonalan ® 

### HP (GF

- 1740)

- 35.1%
Ethalfluralin (MRID 49385904 ).

These studies are presented are marked in bold in Table 19 of the terrestrial taxa endpoints

. Only descriptions of these studies are provided below. Refer to previous assessments for more comprehensive descriptions of the studies that are not included here.

Acute Toxicity to Japanese Quail ( Coturnix japonica) (MRID 48915501)

The acute ora l toxicity of ethalfluralin to Japanese quail was assessed over 14 days in a limit

dose study (MRID 48915501) . No mortality, clinical signs of toxicity, or effects on body weight were observed at the limit dose of 2000 mg/kg bw. The acute oral LD 50 

### was > 2000 mg/kg bw.

E thalfluralin GF

- 705 is classified as practically non

- toxic to the Japanese quail on an acute oral

exposure basis. This toxicity study is classified as scientifically sound and satisfies the guideline requirement for an acute oral toxicity study.

### 42 Acute Toxicity to the Zebra Finch ( Taeniopygia guttata ) (MRID 48915502)

The acute oral toxicity of ethalfluralin to passerine birds ( i.e

., Zebra finches ) was assessed over 14 days in a limit

- dose study (MRID 48915502)

. No mortality, clinical signs of toxicity, or effects on body weight or food consumption were observed in the 2000 mg ai/kg bw group. The
acute oral LD 50 

### was >2000 mg ai/kg bw. Therefore ethalfluralin is classified as practically non

toxic to zebra finc hes on an acute oral basis. This toxicity study is classified as scientifically sound and satisfies the guideline requirement for an acute oral toxicity study with a passerine species.

Toxicity of Etha l fluralin ( Sonalan ® 

### HFP GF

- 1742) to Terrestrial Vascular Plants Vegetative Vigor (MRID 48915901)

The effect of formulated e thalfluralin ( Sonalan ® 

### GF

- 1742 ; 35.1 % ethalfluralin ) on the vegetative vigor of monocotyledonous ( monocots: grain sorghum, s orghum bicolor; onion, Allium cepa ; ryegrass, Lolium perenne ; and oat, Avena sativa ) and dicot yledonous ( dicots: oilseed rape, Brassica napus ; carrot, Daucus carola ; soybean, Glycine max ; cucumber, Cucumis

sativus ; sugar beet, Beta vulgaris , and tomato, Lycopersicon esculentum ) crops was studied at a
nominal treatment rates ranging from 0.00 7 to 1.68 lbs a.i./A (MRID 48915901)

. The most sensitive monocot was ryegrass, based on decreased fresh weight with NOAEC and IC 25 

### values
of 0.053 and 0.212 lb ai/A, respectively. The most sensitive d icot species, could not be determined due to a lack of toxicity; NOAEC and EC/IC 25 

### values were 1.68 and >1.68 lb ai/A, respectively.

Toxicity of Etha l fluralin ( Sonalan ® 

### HFP GF

- 1742) to Terrestrial Vascular Plants Seedling Emergence (MRID 49385904)

The effect of formulated etha l fluralin ( Sonalan ® 

### GF

- 1742 ; 35.1 % ethalfluralin ) on the seedling emergence of monocot s (corn, Zea mays ; oat; onion; and ryegrass) and dicot crops (carrot; cucumber; oilseed rape; soybean; sugar beet, Beta vulgaris ; and tomato) was studied at rates ranging from 0.00328 to 1.68 lb ai/A (MRID 49385904) . The most sensitive monocot was ryegrass based on reduced fresh weight, with IC 05 

### and EC 25 

### values of 0.00195 and 0.0183 lb ai/A, respectively

.

The most sensitive dicot species w as tomato based on reduced fresh weight, with NOEC and
EC 25 

### values of 0.105 and 0.139 lb ai/A, respectively. Phytotoxic effects reported included epinasty (bending outward) , leaf cupping, lodging, stunting, chlorosis, necrosis, mosaic, leaf wrinkle, and c omplete mortality.

Table 18

. Summary of Toxicity for Terrestrial Taxa Exposed to Ethalfluralin.

Exposure
Scenario Species Scientific
Name Exposure
Duration Toxicity
Reference

Value Effects Reference

(Classification)

Mammals

### 43 Exposure
Scenario Species Scientific

Name Exposure
Duration Toxicity
Reference

Value Effects Reference

(Classification)

Acute Laboratory

Rat Rattus norvegicus Acute Oral LD 50 = 5000 mg/kg bw Mortality Acc. No.
00135189 (Acceptable)

Practically non

toxic

Chronic Laboratory

Rat Rattus norvegicus Chronic NOAEL = 61 mg/kg

bw;
LOAEL > 61 mg/kg
bw Reproduction MRID 43868313,
44073701 (Acceptable)

Invertebrates

Acute
Contact Honey bee Apis mellifera 48 hours LD 50 >51

μg a

. i

. /bee Mortality MRID
41613914
(Acceptable) Practically non

toxic

Birds

Acute (Dose

based) Bobwhite Quail Colinus virginianus 14days LD 50 > 2000 mg

a.i./kg Mortality Acc. No.
00094760

(Acceptable) Practically non

toxic

Acute (Dose

based) Japanese Quail Coturnix
coturnix japonica 14days LD 50 >2000 mg a.i./kg bw Mortality MRID
48915501

(Acceptable) Practically

non
- toxic

Acute (Dose

based) Mallard
Duck Anas platyrhynchos 14 days LC 50 = >5000 mg/kg bw Mortality Acc. No.
00094762

(Acceptable) Practically non

toxic

Acute (Dose

based) Zebra
finch Taeniopygia
guttata 14 days LD 50 >2000 mg a.i./kg Mortality MRID
48915502

(Acceptable) Practically

non
- toxic

Acute (Dietary

based) Bobwhite Quail Colinus virginianus 8 days LC 50 >5000 mg/kg diet N/A Acc. No.
070677

(Acceptable)

Acute (Dietary

based) Mallard
Duck Anas platyrhynchos 8 days LC 50 >5000 mg/kg diet N/A Acc. No.
070677 (Acceptable)

### 44 Exposure
Scenario Species Scientific

Name Exposure
Duration Toxicity
Reference

Value Effects Reference

(Classification)

Chronic Mallard
Duck Anas platyrhynchos 21 weeks NOAEL =
1000 mg/kg diet

NOAEL
>1000 mg/kg diet N/A Acc. No.
00094763 (Acceptable)

Reproduction

Plants

Seedling Emergence
With TGAI ND
Sorghum vulgare 21 days EC 25 = 0.09 lb

a

. i

. /A Plant weight Acc. No.
47874101

(Monocot) NOAEC =
0.06lb

a

. i

. /A Acceptable

Sugar beet

Beta vulgaris 21 days EC 25 = 0.11 lbs

a.i./A Fresh Weight MRID
47874101

(Dicot) NOAEL
=0.1048
lbs a.i./A (Supplemental)

Seedling Emergence ND

Lolium

perenne 21 days EC 25 = 0.0183 lb

a

. i

. /A EC0 5 was used in lieu
of NOAEC
since IC25
lower than
NOEAEC MRID
49385904

(Monocot) I C 05 = 0.00195

lb a

. i

. /A Acceptable

Tomato
Lycopersicon
esculentum 21 days EC 25 = 0.139 lbs

a.i./A Fresh Weight MRID
49385904

(Dicot) NOAEL
=0.105 lbs

a.i./A (Acceptable)

Vegetative Vigor with

TGAI Sorghum Sorghum vulgare 21 days EC 25 > 1.7
lbs a.i./A Shoot Length MRID
43465002

(Monocot) NOAEL =
0.43 lbs

ai/A (Acceptable)

Cotton

Cotton 21 days EC 25 = 0.27 lbs

a.i./A Shoot Length MRID
42904201

(Dicot) NOAEL =
0.027 lbs

a.i./A (Acceptable)

Vegetative Vigor with

GF

- 1742 Ryegrass

Lolium

perenne 21 days EC 25 = 0.212 lbs

a.i./A Fresh Weight MRID
48915901 (Acceptable) (Monocot) NOAEL
=0.053 lbs

a.i./A

ND ND 21 days EC 25 >1.68
lbs a.i./A ND

### 45 Exposure
Scenario Species Scientific

Name Exposure
Duration Toxicity
Reference

Value Effects Reference

(Classification)

(Dicot) NOAEL =
1.68lbs
a.i./A



### Although ethalfluralin degrades to several minor degradates, they are not expected to be of environmental concern relative to the parent compound.



## 5.7 **ECOTOX Open Literature**

Open literature studies are identified using EPA’s ECOTOXicology database (ECOTOX) (USEPA, 2007 c ), which employs a literature search engine for locating chemical toxicity data for aquatic life, terrestrial plants, and wildlife. No additional data on ethalf l uralin w as identified through this review with endpoints more sensitive than those that were su bmitted

.



## 5.8 **Review of Incident Data**

Incident reports submitted to EPA since approximately 1994 have been tracked by assignment of “incident numbers” in an Incident Data System (IDS), microfiched, and then entered into a second database, the Ecological Incide nt Information System (EIIS; USEPA 2007b). An effort has also been made to enter information to EIIS on incident reports received prior to
establishment of current databases

.

A preliminary review of the EIIS database indicates that there are 99 incidents involving terrestrial plants associated with the use of ethalfluralin since 1996. Incidents were reported in all seasons and resulted from both registered uses as well as occasional misuse of the product of both granular and emulsifiable ( EC ) formulation s. The magnitude of damage ranged from a small area (1 acre) to the entire treated crop and over 800 acre s

. The incidents ranged from applications in all seasons (spring, summer, autumn and winter) from both granular and spray ground applications. These incidents are detailed in Table 19

.

Table 19

. Summary of Ecological Incidents as found in EIIS from the Usage of Ethalfluralin (Note: In every incident, the taxa affected were terrestrial plants)

.

Incident

ID Year Legality Certainty State Application
Method Product Comments

I013636

- 042 2002 Registered

use Highly
Probable ND Broadcast Sonalan ® Ethalfluralin was applied to dry beans in 2001, and then wheat was planted in 2002. Carryover of
ethalfluralin residues may

have caused the injury
due to extremely dry

winter conditions
follow ing the harvest of the dry beans

### 46 Incident

ID Year Legality Certainty State Application
Method Product Comments

I009516

- 003 1999 Registered

Use Possible ND Broadcast S onalan ® HFP Canola crop showed decreased growth and abnormal roots. Heavy
rain and cold conditions

were present shortly before application.

I010927

- 021 2000 Registered

Use Possible ND Spray S onalan ® HFP 707 acres of soybeans affected by crop stand loss, reported that cool wet soils were prevalent throughout area during the month and may have
contributed

I014702

- 067 2003 Registered

use Possible ND Broadcast Sonalan ® Damaged wheat crop resulting from carryover
from sunflower application with severe drought conditions and
minimal breakdown of
Sonalan ®

I008183

- 001 1997 Undetermined Possible CA Broadcast S onalan ® HFP Alleged damage of dry beans due to treatment, excess moisture may have
also contributed

I012366

- 006 2001 Registered

use Possible IL N/R Sonalan ® EC 21 acres of damaged apple crops reported,

unknown whether

application of
ethalfluralin was the

cause

I012457

- 016 2001 Undetermined Possible GA N/R Sonalan ®

--

I011444

- 015 2001 Misuse (accidental) Possible GA N/R S onalan ® There is no evidence that
ethalfluralin was responsible for the fish kills reported

I010927

- 025 1998 Undetermined Possible Canada N/R EDGE Canola crop damaged when plant failed to emerge properly, a test conducted in June, 1998

found ethalfluralin on

canola at 0.58 ppm.

I011838

- 067 2001 Undetermined Possible OK N/R Sonalan ®

--

I011838

- 049 2001 Undetermined Possible GA N/R S onalan ®

--

I007755

- 023 1998 Registered

Use Possible ND Soil incorporation S onalan ® HFP Pre

- plant incorporation on 47 acres of wheat crop

allegedly resulted in
swollen roots and root hair growth

### 47 Incident

ID Year Legality Certainty State Application
Method Product Comments

I014702

- 066 2003 Registered

use Possible ND Broadcast Sonalan ® 10G Carryover from canola application in 2002 coupled with a severe drought led to damaged
stand of durum wheat in
2003

I008323

- 001 1998 Undetermined Possible Canada N/R EDGE
GRANULAR Unknown if label directions followed, canola crop allegedly

failed to emerge or germinate from seed

I011838

- 038 2001 Undetermined Possible GA N/R S onalan ®

--

I011838

- 037 2001 Undetermined Possible GA N/R S onalan ®

--

I011838

- 036 2001 Undetermined Possible GA N/R S onalan ®

--

I009516

- 001 1999 Registered

Use Possible TX Broadcast S onalan ® HFP Application was a possible cause of damage, Dow Agrosciences inspector judged the peanut crop was diseased

I009516

- 009 1999 Registered

Use Possible ND Broadcast S onalan ® HFP Dow inspector determined damage to 90
acres of canola after soil sample analysis and plant inspection was more due to FARGO product than
S onalan ®

I011838

- 010 2000 Undetermined Possible GA N/R S onalan ®

--

I007755

- 017 1998 Registered

Use Possible ND PPI/GROUND/

S onalan ® 10G 570 acres in wheat crop allegedly demonstrated crop injury after application BROADCAST

I020627

- 001 2000 Misuse Possible WA N/R N/R

--

I009515

- 002 1999 Registered

use Possible ND Broadcast S onalan ® 10G Stand reduction in canola crop reported

I014702

- 071 2003 Registered

use Possible MN Broadcast Sonal a n ® 80 acres of canola damage allegedly due to application of
ethalfluralin

I012457

- 019 2001 Undetermined Possible GA N/R Sonalan ®

--

I011838

- 066 2001 Undetermined Possible OK N/R Sonalan ®

--

### 48 Incident

ID Year Legality Certainty State Application
Method Product Comments

I009515

- 001 1999 Misuse (accidental) Possible ND Soil incorporation S onalan ® 10G Poor emergence of wheat reported but may have
been due to soil that was inspected to be too wet for seeding

I013550

- 001 2002 Registered

use Possible TX N/R Sonalan ® HFP Reported that a Sonalan tank may have been
contaminated with some source of Picloram, which is not approved for
peanuts

I011838

- 045 2001 Undetermined Possible GA N/R S onalan ®

--

I011838

- 046 2001 Undetermined Possible GA N/R S onalan ®

--

I011838

- 040 2001 Undetermined Possible GA N/R PROWL

--

I011838

- 044 2001 Undetermined Possible GA N/R S onalan ®

--

I009516

- 002 1999 Registered

Use Possible ND Broadcast S onalan ® H FP Soybean crop showed decreased growth and abnormal roots. Heavy
rain and cold conditions

were present shortly before application.

I011838

- 042 2001 Undetermined Possible GA N/R S onalan ®

--

I011838

- 048 2001 Undetermined Possible GA N/R S onalan ®

--

I009516

- 012 1999 Registered

Use Probable MI Broadcast S onalan ® HFP Damage to 180 acres of beans reported, adjacent

area with no spraying showed no symptoms

I009516

- 006 1999 Registered

Use Probable ND Broadcast S onalan ® HFP Severe thinning of 30
acres of canola reported

I009516

- 011 1999 Registered

Use Probable ND Broadcast S onalan ® HFP Thinning reported in 72
acres of treated canola.

I009516

- 007 1999 Registered

Use Probable ND Broadcast S onalan ® HFP Severe thinning of 157 acres of canola reported

I009516

- 008 1999 Registered

Use Probable ND Broadcast S onalan HFP Severe thinning of 110 acres of canola reported

I009516

- 004 1999 Registered

Use Probable ND Broadcast S onalan HFP Severe thinning of 100 acres of canola reported

I010927

- 020 2000 Undetermined Probable ND N/R S onalan ® 10G Determined by Dow inspector that ethalfluralin was applied a year before

a mix of trifluralin and triallate, which is known

### 49 Incident

ID Year Legality Certainty State Application
Method Product Comments

to have damaging effects
on wheat

I010927

- 018 2000 Misuse (accidental) Probable ND Spray S onalan ® 10G

--

I010927

- 026 1999 Registered

Use Probable Canada N/R EDGE 320 acres of canola crop damaged, AFC Agra Services Ltd., concluded
ethalfluralin was responsible

I010927

- 023 2000 Registered

Use Probable ND Spray S onalan ® HFP It was not determined whether the deep seeding, cold weather, or

application of
ethalfluralin that caused

thinned canola stand

I012366

- 003 2001 Registered

use Probable ND Broadcast Sonalan HFP 839 acres of canola saw severe crop thinning and

poor emergence

I009510

- 001 1999 Registered

Use Probable IA Broadcast N/R Soybean crop allegedly damaged by application

I010927

- 022 2000 Registered

Use Probable ND Spray S onalan ® HFP 500 acres of canola stand was thinned compared to
untreated area

I009516

- 013 1999 Registered

Use Probable ND Broadcast S onalan ® HFP Poor stand in 195 acres of canola reported

I006196

- 012 N/R Registered

Use Probable ID N/R S onalan ® No analytical data included in report, damage to wheat reported
after treatment

I009969

- 001 1999 Registered

Use Probable CA Broadcast S onalan ® HFP Bean crop affected when hypocotyl was swollen following emergence, cold weather also may

have been a factor

I009516

- 010 1999 Registered

Use Probable ND Broadcast S onalan ® HFP Thinning reported in 21

acres of treated canola.

I010927

- 016 2000 Misuse (accidental) Probable ND Spray S onalan ® 10G This use was accidental as the product should not be

used on wheat, it was
what remained from an application the previous

year

I010927

- 017 2000 Misuse (accidental) Probable ND Spray S onalan ® 10G This use was accidental as the product should not be

used on wheat, it was
what remained from an application the previous

year

### 50 Incident

ID Year Legality Certainty State Application
Method Product Comments

I010927

- 019 2000 Misuse (accidental) Probable ND Spray S onalan ® 10G This use was accidental as the product should not be

used on canola, it was
what remained from an application the previous

year

I012366

- 005 2000 Registered

use Probable ND Broadcast Sonalan ® HFP 129 acres of soybeans showed poor emergence, stunted or slowed yield; a

check strip showed a
difference from treated

vs. non

- treated

I006197

- 009 N/R Registered

Use Probable ID N/R S onalan ® 10G No analytical data included in report, abnormal growth reported in wheat crop after

treatment

I006196

- 009 N/R Registered

Use Probable ID N/R S onalan ® No analytical data included in report, damage to wheat reported
after treatment

I006196

- 003 N/R Registered

Use Probable ND N/R S onalan ® No analytical data included in report, reduced emergence reported in soybean crop
after treatment

I006196

- 004 N/R Registered

Use Probable MN N/R S onalan ® No analytical data included in report, reduced emergence reported in soybean crop
after treatment

I006196

- 005 N/R Registered

Use Probable ND N/R S onalan ® No analytical data included in report, slow

emergence reported in

soybean crop after

treatment

I006196

- 006 N/R Registered

Use Probable ID N/R S onalan ® No analytical data included in report, poor development of wheat

crop after treatment

I003130

- 001 1996 Registered

Use Probable MT N/R S onalan ® ® 10G Spring crops following pesticide treatment
demonstrated a thin stand

I006196

- 007 N/R Registered

Use Probable ID N/R S onalan ® No analytical data included in report, damage to wheat reported
after treatment

I006197

- 011 N/R Registered

Use Probable ID N/R S onalan ® 10G No analytical data included in report, abnormal growth reported in wheat crop after

treatment

### 51 Incident

ID Year Legality Certainty State Application
Method Product Comments

I006197

- 003 N/R Registered

Use Probable ND N/R S onalan ® 10G No analytical data included in report, damage to wheat reported
after treatment

I006454

- 001 1997 Registered

Use Probable MN N/R S onalan ® 10 G The corn crop appeared stunted and pale in color

I009969

- 002 1999 Undetermined Probable CA Broadcast S onalan ® HFP 100 acres of beans reported damaged, emergence of beans affected by tank mix of
Sonalan ® /DUAL

I014702

- 070 2003 Registered

use Probable ND Broadcast Sonalan ® Damaged wheat crop resulting from carryover
from sunflower application with severe drought conditions and
minimal breakdown of
Sonalan ®

I014702

- 068 2003 Registered

use Probable ND Broadcast Sonalan ® Damaged wheat crop resulting from carryover
from sunflower application with severe drought conditions and
minimal breakdown of
Sonalan ®

I013636

- 045 2002 Registered

use Probable ND Broadcast Sonalan ® HFP Crop damage to beans
determined to be due to seed cracks and a damaged embryonic shoot
as well as cutworms

I013636

- 046 2002 Registered

use Probable ND Broadcast Sonalan ® 120 acres of canola reported damaged with thin stand, check strip indicated no damage

I014702

- 069 2003 Registered

use Probable ND Broadcast Sonalan ® Damaged wheat crop resulting from carryover

from application with severe drought conditions
and minimal breakdown
of Sonalan ®

I016962

- 037 2005 Registered

Use Probable ND Band, incorporated Sonalan ® HFP

--

I013636

- 043 2001 Registered

Use Probable OR Broadcast Sonalan ® HFP Carryover of ethalfluralin application to dry beans from grass seed caused damage allegedly

I013636

- 044 2000 Registered

Use Probable OR Broadcast Sonalan ® HFP Carryover from dry beans in 2000 allegedly caused

subsequent crops to be damaged

### 52 Incident

ID Year Legality Certainty State Application
Method Product Comments

I003146

- 001 1996 Registered

Use Probable MN N/R S onalan ® HFP Treated soybean crop demonstrated disease, compaction, delayed emergence, and swollen hypocoty l

I006197

- 004 N/R Registered

Use Probable ND N/R S onalan ® 10G No analytical data included in report, thin stand of wheat reported
after treatment

I012366

- 004 2000 Registered

Use Probable ND Broadcast Sonalan ® HFP Soybeans in treated and
untreated field had a difference in emergence, stand and yield

I009516

- 005 1999 Registered

Use Probable ND Broadcast S onalan ® HFP Severe thinning of 50 acres of canola reported

I006196

- 011 N/R Registered

Use Probable ID N/R S onalan ® No analytical data included in report, damage to wheat reported
after treatment

I006196

- 013 N/R Registered

Use Probable MN N/R S onalan ® No analytical data included in report, damage to sugar beets reported after treatment

I006196

- 014 NR Registered

Use Probable ND N/R S onalan ® No analytical data included in report, non

-

emergence of canola reported after treatment

I006196

- 015 N/R Registered

Use Probable WA N/R S onalan ® No analytical data included in report, damage to dry bean crop reported after treatment

I006196

- 016 N/R Registered

Use Probable MN N/R S onalan ® No analytical data included in report, damage to corn crop reported after treatment

I004810

- 001 N/R Registered

Use Probable ND N/R S onalan ® 10G No analytical data included in report, reduced emergence reported in wheat crop
after treatment

I006196

- 001 N/R Registered

Use Probable TX N/R S onalan ® No analytical data included in report, reports that peanuts grown were

stunted after exposure

I006196

- 008 N/R Registered

Use Probable ID N/R S onalan ® No analytical data included in report, damage to wheat reported
after treatment

I006196

- 010 N/R Registered

Use Probable ID N/R S onalan ® No analytical data included in report, damage to wheat reported
after treatment

### 53 Incident

ID Year Legality Certainty State Application
Method Product Comments

I006197

- 005 N/R Registered

Use Probable ND N/R S onalan ® 10G No analytical data included in report, poor emergence reported in wheat crop after treatment

I006197

- 006 N/R Registered

Use Probable ND N/R S onalan ® 10G No analytical data included in report, damage to wheat reported
after treatment

I006197

- 007 N/R Registered

Use Probable ND N/R S onalan ® 10G No analytical data included in report, poor emergence reported in wheat crop after treatment

I006197

- 008 N/R Registered

Use Probable ID N/R S onalan ® 10G No analytical data included in report, abnormal growth reported in wheat crop after

treatment

I006197

- 010 N/R Registered

Use Probable ID N/R S onalan ® 10G No analytical data included in report, abnormal growth reported in wheat crop after

treatment

I004823

- 001 1997 Registered

Use Probable IL N/R S onalan ® HFP Treatment allegedly rendered a crop that demonstrated thin stand,

swollen hypocotyls, brown roots, and dying

I006197

- 001 N/R Registered

Use Probable ND N/R S onalan ® 10G No analytical data included in report, damage to oats reported
after treatment

I006196

- 002 N/R Registered

Use Probable MN N/R S onalan ® No analytical data
included in report, reports that soybeans grown were

stunted after exposure

I012366

- 007 2001 Registered

use Probable MT N/R S onalan ® 10G 56 acres of dry bean crop damaged due to weeds that were allowed to grow

because of ineffective product

I006197

- 002 N/R Registered

Use Probable ND N/R S onalan ® 10G No analytical data included in report, slow emergence reported in wheat crop after treatment



### The Avian Monitoring Information System (AIMS), which is maintained by the American Bird Conservancy, indicates there are no incidents for wildlife.

An absence of reported incidents should not be construed as the absence of incidents. Incident reports for non

- target organisms typically provide information only on mortality events and plant

### 54 damage incidents. Except for phytotoxic effects in terrestrial plants, sublethal effects, such as reduced growth or impaired reproduction, are rarely reported. EPA’s ch anges in the registrant reporting requirements for incidents in 1998 may account for a reduced number of reported incidents. Registrants are now only required to submit detailed information on ‘major’ fish, wildlife, and plant incidents. Minor fish, wild life, and plant incidents, as well as all other non

target incidents, are generally reported aggregately and are not included in the EIIS. In addition, there have been changes in state monitoring efforts due to a lack of resources. However, the
incident data that are available suggest that exposure pathways for ethalfluralin are complete and that exposure levels are sufficient to result in field

- observable effects for terrestrial plants

.



## 6 Risk Characterization

Risk characterization is the integration of exposure and effects characterization to determine the potential ecological risk from the use of ethalfluralin and the likelihood of adverse effects on aquatic and terrestrial wildlife / plants based on varying pes ticide

- use scenarios. The risk characterization provides an estimation and a description of the risk; articulates risk assessment assumptions, limitations, and uncertainties; synthesizes an overall conclusion; and provides the risk managers with informati on to make regulatory decisions.



## 6.1 **Risk Estimation**

Results of the exposure modeling and toxicity effects data are used to evaluate the likelihood of adverse ecological effects on non

- target species. For the assessment of ethalfluralin risks, the risk quotient (RQ) method is used to compare exposure and me asured toxicity values (Table 20 )

. The EECs are divided by the most sensitive acute and chronic toxicity values. The RQs are then compared to the Agency’s levels of conc ern (LOCs). These LOCs, summarized in Table 2 0

, are the Agency’s interpretive policy and are used to analyze potential risk to non

- target organisms and the need to consider regulatory action. These criteria are used to indicate when a pesticide’s

use as directed on the label has the potential to cause adverse effects on non

- target organisms.

### 55 Table 20

. Risk presumptions for terrestrial animals based on risk quotients (RQ) and levels of concern (LOC).

Risk Presumption RQ LOC

Birds

Acute Risk EEC 1 /LC 50 or LD 50 /ft 2 or LD 50 /day 3 0.5

Acute Restricted Use EEC/LC 50 or LD 50 /ft 2 or LD 50 /day (or LD 50 < 50 mg/kg) 0.2

Acute Endangered Species EEC/LC 50 or LD 50 /ft 2 or LD 50 /day 0.1

Chronic Risk EEC/NOAEC 1

Wild Mammals

Acute Risk EEC/LC 50 or LD 50 /ft 2 or LD 50 /day 0.5

Acute Restricted Use EEC/LC 50 or LD 50 /ft 2 or LD 50 /day (or LD 50 < 50 mg/kg) 0.2

Acute Endangered Species EEC/LC 50 or LD 50 /ft 2 or LD 50 /day 0.1

Chronic Risk EEC/NOAEC 1

1 abbreviation for Estimated Environmental Concentration (ppm) on avian/mammalian food items

2 mg/ft 2

3 mg of toxicant consumed/day

LD 50 * wt. of bird

LD 50 * wt. of bird

Risk presumptions for aquatic animals based on risk quotients (RQ) and leve ls of concern (LOC).

Risk Presumption RQ LOC

Acute Risk EEC 1 /LC 50 or EC 50 0.5

Acute Restricted Use EEC/LC 50 or EC 50 0.1

Acute Endangered Species EEC/LC 50 or EC 50 0.05

Chronic Risk EEC/NOAEC 1

1 EEC = (ppm or ppb) in water

Risk presumptions for plants based on risk quotients (RQ) and levels of concern (LOC).

Risk Presumption RQ LOC

Terrestrial and Semi

- Aquatic Plants

Acute Risk EEC 1 /EC 25 1

Acute Endangered Species EEC/EC 05 or NOAEC 1

Aquatic Plants

Acute Risk EEC 2 /EC 50 1

Acute Endangered Species EEC/EC 05 or NOAEC 1

1 EEC = lbs ai/A
2 EEC = (ppb/ppm) in water



## 6.2 **Non**

**- target Aquatic Animals and Plants** 

### 56 6.2.1 Acute Risk to Aquatic Animals

Acute RQs were derived for exposure of freshwater and estuarine/marine fish and invertebrates

to ethalfluralin for application rates ranging from 0.75 lbs a.i . / A to 1.7 lbs a.i . / A (Table 21 ).

A cute RQs for freshwater fish rang e from 0.11 to 0.39 and exceed th e LOCs for acute risk to listed species (LOC = 0.05) but not for non

- listed species (LOC= 0.5 ). Similarly, acute RQs ranging from 0.06 to 0.21 for freshwater invertebrates exceed the LOC for acute risk to listed species. For estuarine/marine fish and invertebrates, the LOC for listed species i s only exceeded at the highest application rate with RQs of 0.05 and 0.07 respectively. There a re no LOC
exceedances for non

- listed estuarine/marine species for any crop or application rate.

Table 21

. Acute RQs for fish and aquat ic invertebrates exposed to ethalfluralin.

Use App.

Date App.

Rate
lb/A Peak FW Fish FW
Invert SW Fish SW
Invert FW
Fish FW
Invert SW
Fish SW
Invert

LC 50 (μg/L) EC 50 (μg/L) LC 50 (μg/L) EC 50 (μg/L) RQ RQ RQ RQ

Cucurbits 30

- Oct 1.7 12.5 32 60 240 170 0.39 a 0.21 a 0.05 a 0.07 a

Cucurbits 30

- Oct 0.75 5.52 32 60 240 170 0.17 a 0.09 a 0.02 0.03

Sunflo wer 10

- Jun 1.7 5.91 32 60 240 170 0.18 a 0.10 a 0.02 0.03

Soybean 10

- Oct 1.31 6.02 32 60 240 170 0.19 a 0.10 a 0.03 0.04

Peanut 1

- May 1.15 4.12 32 60 240 170 0.13 a 0.07 a 0.02 0.02

Potatoes 10

- May 1.03 3.54 32 60 240 170 0.11 a 0.06 a 0.01 0.02

a Bolded values denote that the RQ exceeds acute risk to listed species level of concern ( LOC ) of 0.05

. The non

- listed species LOC is 0.5.



### 6.2.2 Chronic Risk to Aquatic Animals

Chronic RQs were derived for exposure of freshwater fish and invertebrates and est uarine/marine
invertebrates to ethalfluralin ( Table 22 ). The chronic RQs for freshwater fish range from 1.0 to
3.4 and exceed the chronic risk LOC (1.0) for every application rate and crop modeled. For
estuarine/marine fish

, the RQ only exceed s the LOC at the highest application rate with an RQ of
1.13. None of the RQs (ranging from 0.03 to 0.15) for estuarine/marine and freshwater
invertebrates exceed the chronic risk LOC for any use or application rate modeled

,

Table 22

. Chronic RQs for fish and aquatic invertebrates exposed to ethalfluralin.

Use App.
Rate
lb/A Estimated
Environmental
Concentration (μg/L) SW
Invert FW
Invert SW
Fish FW
Fish SW
Invert FW
Invert SW
Fish FW
Fish

NOAEC

(μg/L) NOAEC (μg/L) NOAEC (μg/L) NOAEC (μg/L) RQ RQ RQ RQ 2 1

- day 60

- day

Cucurbits 1.7 3.55 1.36 29.1 24 1.200 0.40 0.12 0.15 1.13 a 3.40 a

Cucurbits 0.75 1.57 0.6 29.1 24 1.200 0.40 0.05 0.07 0.50 1.50 a

### 57 Sunflower 1.7 1.59 0.63 29.1 24 1.200 0.40 0.05 0.07 0.53 1.58 a

Soybean 1.31 1.41 0.59 29.1 24 1.200 0.40 0.05 0.06 0.49 1.48 a

Peanut 1.15 1.37 0.57 29.1 24 1.200 0.40 0.05 0.06 0.48 1.43 a

Potatoes 1.03 1.01 0.4 29.1 24 1.200 0.40 0.03 0.04 0.33 1.00 a

* Fish toxicity data are compared to the 60

- day EEC while the invertebrate toxicity data are compared to the 21

- day EEC.

a Bolded values indicate RQs exceeds, the chronic risk level of concern (LOC) of 1.0

.



### 6.2.3 Risk to Sediment

- d welling Invertebrates

Chronic RQs were derived for freshwater sediment

- dwelling invertebrates using both pore water and sediment

- based EECs and the toxicity endpoints for both Hyallela sp. and Chironomous sp.
The sediment

- based EECs a re normalized to the organic carbon (OC) content of the sediment. The RQs based on pore water d o not exceed the chronic risk LOC of 1.0 for any application rate
or use modeled and a re <0.01 in all cases ( Table 23 )

. The OC

- normalized sediment

- based RQs
for Hyalella rang e from 1.3 to 4 and exceed the chronic risk LOC for all uses and application
rates modeled ( Table 24 ). The OC

- normalized sediment

- based RQs for Chironomous range from 0.13 to 0.4 and d o not exceed the chronic risk LOC for any scenario modeled. There are no data available for t he benthic estuarine/marine species of Leptocheirus. Although RQ values for the freshwater midges did not exceed the chronic risk LOC, those for Hyalella exceed the
chronic risk LOC. Given the propensity of ethalfluralin to bind to the sediments, risk is presumed to estuarine/marine sediment

- dwelling invertebrates (based on sediment OC

normalized EEC s) until more information is received to permit evaluation of risks

.

Table 23

. P orewater

- based RQs for freshwater sediment

- dwelling invertebrates.

Model
Scenario

Use Maximum Application

rate

lb s a.i. /A Porewater
EEC (μg/L) Hyalella Chironomous Hyalella Chironomous

Porewater
NOAEC

(μg/L) Porewater
NOAEC

(μg/L) Porewater RQ Porewater RQ 21

- day

Cucurbits 1.7 0.33 92 270 <0.01 <0.01

Sunflower 1.7 0.28 92 270 <0.01 <0.01

Peanut 1.15 0.19 92 270 <0.01 <0.01

Potatoes 1.03 0.19 92 270 <0.01 <0.01



### Table 24

. Organic carbon normalized sediment based RQs for freshwater sediment dwelling invertebrates.

Model
Scenario

Use Maximum Application

rate
lbs a.i. /A Sediment
EEC (μg/L) Hyalella Chironomous Hyalella Chironomous

Sediment (μg ai/Kg

OC) Sediment (μg ai/Kg

OC) Sediment
OC
normalized RQ Sediment
OC
normalized RQ Sediment

μ g ai/Kg

OC

Cucurbits 1.7 1939.75 480 4800 4.04 a 0.40

Sunflower 1.7 1117 480 4800 2.33 a 0.23

Peanut 1.15 750 480 4800 1.56 a 0.16

Potatoes 1.03 625 480 4800 1.30 a 0.13

### 58 a Bolded values indicate RQs exceeds, the chronic risk level of concern (LOC) of 1.0



### 6.2.4 Risk to Aquatic Plants

The RQs for non

- listed vascular plants only exceed the LOC of 1.0 for the highest application rate modeled with an RQ of 1.7. The RQs for listed vascular plants range from 3.0 to 10.4 and exceed the LOC of 1.0 for every use and application rate modeled ( T able 25 )

. None of the RQs
for non

- vascular plants exceed the LOC of 1.0 for any application rate or use modeled with the exception of the RQ for listed non

- vascular plants at the highest application rate.

Table 25

. RQs for non

- va scular and vascular aquatic plants exposed to ethalfluralin.

Model
Scenario

Use Maximum Application

rate
lb s a.i./A EEC (μg/L) Toxicity Values RQs

Non

- Vascular
Plant Vascular Plant Non

- Vascular
Plant Vascular Plant

Non

listed
EC 50 Listed
NOAEC Non

listed
EC 50 Listed
NOAEC Non

listed Listed Non

listed Listed

Peak

Cucurbits 1.7 12.5 25.30 10.90 7.30 1.20 0.5 1.1 a 1.7 b 10.4 a

Cucurbits 0.75 5.52 25.30 10.90 7.30 1.20 0.2 0.5 0.8 4.6 a

Sunflower 1.7 5.91 25.30 10.90 7.30 1.20 0.2 0.5 0.8 4.9 a

Soybean 1.31 6.02 25.30 10.90 7.30 1.20 0.2 0.6 0.8 5.0 a

Peanut 1.15 4.12 25.30 10.90 7.30 1.20 0.2 0.4 0.6 3.4 a

Potatoes 1.03 3.54 25.30 10.90 7.30 1.20 0.1 0.3 0.5 3.0 a

a Bolded R Q exceed s the risk to listed species LOC

. b Bolded R Q exceeds the risk to non

- listed species LOC



## 6.3 **Non**

**- target Terrestrial**  **Animals**

6.3.1 Acute Risk to Birds and Mammals

Ethalf l uralin is characterized as practically non

- toxic to birds on both an acute oral and subacute dietary exposure basis. Avia n acute toxicity tests did not have any observed mortality, and therefore no definitive toxicity values with the endpoints being great er than values of the highest doses tested. Therefore, avian acute RQs were not calcula ted. The acute endpoint for mammals is 5000 mg/kg (MRID 00135189) and is ethalf l uralin is considere d practically non

- toxic to
mammals on an acute oral exposure basis. None of the R Qs exceed the LOC for either listed species (LOC=0.1) or unlisted species (LOC=0.5). Acute risk to birds and mammals is not anticipated through either emulsifiable concentrate or granular formulations through registered
uses of ethalfluralin.

6.3.2 Chronic Risk to Birds and Mammals

### 59 Avian Species

The NOAEC in the chronic bird toxicity studies was 1,000 ppm, but no adverse effects were observed in these studies. The maximum acute EEC for the proposed uses is 46 2 ppm for
resi dues on short grasses from the alfalfa use with an application rate of 1. 69 lbs a.i . / A. Therefore, even if effects had been observed at the 1000 ppm level, RQ values would not exceed
the chronic risk LOC of 1.0

.

Mammalian Species

The previous assessment did not identify any chronic risk to mammals ( DP# D205884, D296985, and D296987 ). The endpoint used in that assessment could not be confirmed for use in this assessment

. The refore, this assessment utilized the chronic toxicity value of 61 mg/k g bw
based on reduced reproduction. Utilizing this endpoint

, dose

- based RQ values exceed the
chronic risk LOC; however, dietary

- based RQ values for uses of emulsifiable concentrates do not
exceed the chronic risk LOC (Table 26 ) . RQs based on upper

- bound K enaga values ranged from 0.01 to 3.3. RQs for small

- and medium

- sized mammals (15 g and 35 g mammals

, respectively) exceed the chronic risk LOC of 1.0 for short grass, tall grass, broadleaf plants for uses on alfalfa, cucurbits, potatoes and sunflower wi th application rates that ranged from 1 to
1. 69 lbs a.i./A. RQs at the highest application rate of 1.69 also exceed the chronic risk LOC for mammals foraging on arthropods. RQs for large (100 0 gram) mammals only exceed the chronic
risk LOC of 1 for short grass for application rates greater than 1.3 lbs a.i./A

. Chronic risk from dietary exposure was not identified for mammals at any application rate for spray formulations

.

Table 26

. Chronic dose

- based RQs for mammals exposed to proposed spray uses of ethalfluralin.

15 gram "Small" Mammal 35 gram "Medium" Mammal 1000 gram "Large" Mammal

Use (application rate lbs a.i./A)Short GrassTall GrassBroadleaf PlantsFruits/podsArthropodsSeedsShort GrassTall GrassBroadleaf PlantsFruits/podsArthropodsSeedsShort GrassTall GrassBroadleaf PlantsFruits/podsArthropodsSeeds

Alfalfa with
low broadcast spray (1.698) 2.9 1.3 1.6 0.2 1.1 0.0 2.5 1.1 1.4 0.2 1.0 0.0 1.3 0.6 0.7 0.1 0.5 0.0

Potatoes chemigation

(1.028) 1.8 0.8 1.0 0.1 0.7 0.0 1.5 0.7 0.8 0.1 0.6 0.0 0.8 0.4 0.5 0.1 0.3 0.0

Sunflower (1.3) granular, incorporated, chemigation 2.2 1.0 1.2 0.1 0.9 0.0 1.9 0.9 1.1 0.1 0.7 0.0 1.0 0.5 0.6 0.1 0.4 0.0



### 6.3.3 Risks to Piscivorous Birds and Mammals

Ethalfluralin has the ability to bioaccumulate/magnify in the aquatic food chain. In order to assess the magnitude of risk the KABAM model was used to predict the level of concern to higher trophic levels in aquatic food webs. The only LOC exceedance to piscivorous mammals

### 60 feeding on fish containing ethalfluralin residues i s from chronic exposure of the large river otter (RQ = 1.1) at the highest application rate of 1.69 lb ai/A. The RQs for the other mammals modeled ranged from 0.28 for water shrew to 0 .7 for small river otter. The RQs for mammalian acute exposure d o not exceed the acute risk LOC for any group at the highest application rate. The RQs for avian acute and chronic exposure feeding on fish containing ethalfluralin residues
d o not exceed a cute or chronic risk LOC s at the highest application rate modeled (1. 69 lbs ai/A). The one chronic RQ for mammals that exceeded the LOC at the 1.7 lbs ai/A level did not exceed the LOC at the next highest application rate modeled of 1.3 lbs ai/A. Ethalfl uralin is expected to depurate in mammal tissues by 50% within three days o u nces exposure stops. The KABAM model did not assume any depuration so the one exceedance is likely a worst case scenario and risk to piscivorous birds and mammals is likely low.

6.3.4 Risk to Non

- target Terrestrial Plants

There were two new studies using a formulated end product that have been incorporated into the risk assessment for plants. The vegetative vigor study determined that monocots were more
sensitive to formulated ethalfluralin than TGAI whereas dicots were more sensitive to TGAI than the formulated end product. The seedling emergence study with formulated end product had more sensitive endpoints for both m onocots and dicots than the previous TGAI study. RQs were determined using the lowest available endpoint for both monocots and dicots in both the vegetative vigor and seedling emergence studies. The EC25 and NOAEC in the vegetative vigor
studies were 0.2 12 and 0.053 lbs ai/A respectively for monocots and 0.27 and 0.027 respectively
for dicots. The EC25 and NOAEC in the seedling emergence studies were 0.0183 and 0.00195 lbs ai/A respectively for monocots and 0.139 and 0.105 respectively for dicots.

RQs re sulting from off

- site transport from runoff and spray drift of ethalfluralin are presented
below. In general, monocots were more sensitive to ethalfluralin than dicots.

Monocotyledon Species

RQs f or monocots range from <0.1 to 130.7 ( Table 27 )

. RQs values for plants exposed to runoff and spray drift in semi

- aquatic areas exceed the risk to non

- listed and listed species LOC s for every use and application rate modeled.

Table 27

. Monocot RQs from applications of ethalflur alin in the modeled scenarios of Runoff and Spray Drift in Dry areas, Runoff and Spray Drift in Semi

- Aquatic Areas, and Spray Drift only.

Use (application rate lbs a.i./A) Monocot RQ Values

Runoff and Spray Drift (Dry Areas) Runoff and Spray Drift (Semi

- Aquatic Areas) Spray Drift Only

Non

listed Species Listed Species Non

listed Species Listed Species Non

listed Species Listed Species

### 61 Alfalfa, Beans with low broadcast spray EC1 (1.698) 1.86 b 17.44 a 10.22 b 95.90 a 0.93 8.72 a

Alfalfa, Beans with chemigation EC3 (1.698) 5.57 b 52.31 a 13.93 b 130.77 a 4.64 b 43.59 a

Beans granular (1.69) 0.92 8.67 a 9.23 b 86.67 a <0.1 <0.1

Clover 3" incorporated (1.5) 1.23 b 11.54 a 4.92 b 46.15 a 0.82 7.69 a

Cucurbits with low broadcast spray (1.7) 1.86 b 17.44 a 10.22 b 95.90 a 0.93 8.72 a

Dill ground spray (1.13) 0.93 8.69 a 3.70 b 34.77 a 0.62 5.79 a

Lentils, Mustard granular formulation

2" incorporation (0.95) 0.26 2.44 a 2.60 b 24.36 a <0.1 <0.1

Oilseed

- Sunflower,

Jojoba, etc (1.7)
Granular 2 inch incorporation 0.46 4.36 a 4.64 b 43.59 a <0.1 <0.1

Oilseed

- Sunflower,

Jojoba, etc (1.7)
Granular F 3 inch

incorporation 0.17 1.62 a 1.73 b 16.24 a <0.1 <0.1

Oilseed

- Sunflower, Jojoba, etc (1.7) EC3 chemigation 5.57 b 52.31 a 13.93 b 130.7 a 4.64 b 43.59 a

Oilseed

– Crambe, Rapeseed (canola),

etc . group (0.95) EC2 spray with 2 inch incorporation 0.78 7.31 a 3.11 b 29.23 a 0.52 4.87 a

Oilseed

– Crambe, Rapeseed (canola),

etc . group (0.95) G
with 2 inch incorporation 0.26 2.44 a 2.60 b 24.36 a <0.1 <0.1

Oilseed

- Safflower (1.15) granular with 2 inch incorporation 0.31 2.95 a 3.14 b 29.49 a <0.1 <0.1

Peanuts granular formulation (1.15)
with 2 inch incorporation 0.31 2.95 a 3.14 b 29.49 a <0.1 <0.1

Peanuts EC with 2 inch incorporated (1.15) 0.94 8.85 a 3.77 b 35.38 a 0.63 5.90 a

Peas EC (0.75) 2 inch incorporation 0.61 5.77 a 2.46 b 23.08 a 0.41 3.85 a

Peas granular formulation (0.75) 2 inch incorporation 0.20 1.92 a 2.05 b 19.23 a <0.1 <0.1

### 62 Potatoes chemigation (1.028) 3.37 b 31.63 a 8.43 b 79.08 a 2.81 26.36 a

Potatoes ground (1.028) 0.84 7.91 a 3.37 b 31.63 a 0.56 5.27 a

Soybeans Granular (1.3) 2 inch incorporation 0.36 3.33 a 3.55 b 33.33 a <0.1 <0.1

a Bolded R Q exceeds the risk to listed species LOC.

b Bolded RQ exceeds the risk to non

- listed species LOC



### Dicotyledon Species

RQs for dicots ranged from <0.01 to 2.43 ( Table 28 )

. RQs for only six of the twenty uses exceeded
the LOC for listed and non

- listed dicot species. Application rates for these uses ranged from 1 to
1.7 lbs a.i . / A.

Table 28

. Dicot RQs from applications of ethalfluralin in the modeled scenarios of Runoff and Spray Drift in Dry areas, Runoff and Spray Drift in Semi

- Aquatic Areas, and Spray Drift only.

Use (application rate lbs a.i./A) Dicot RQ Values

Runoff and Spray Drift (Dry Areas) Runoff and Spray Drift (Semi

- Aquatic Areas) Spray Drift Only

Non

listed Species Listed Species Non

listed Species Listed Species Non

listed Species Listed Species

Alfalfa, Beans
with low broadcast spray (1.698) 0.24 0.32 1.35 b 1.78 a 0.12 0.16

Alfalfa, Beans with chemigation

EC3 (1.698) 0.73 0.97 1.83 b 2.43 a 0.61 0.81

Beans granular (1.69) 0.12 0.16 1.22 b 1.61 a <0.1 <0.1

Clover 3" incorporated (1.5) 0.16 0.21 0.65 0.86 0.11 0.14

Cucurbits with
low broadcast

spray (1.7) 0.24 0.32 1.35 b 1. 78 a 0.12 0.16

Dill ground spray (1.13) 0.12 0.16 0.49 0.65 <0.1 0.11

Lentils granular
formulation 2" incorporation (0.95) <0.1 <0.1 0.34 0.45 <0.1 <0.1

Oilseed

Sunflower, Jojoba, etc (1.7)
Granular 2 inch incorporation < 0.1 <0.1 0.61 0.81 <0.1 <0.1

### 63 Use (application rate lbs a.i./A) Dicot RQ Values

Runoff and Spray Drift (Dry Areas) Runoff and Spray Drift (Semi

- Aquatic Areas) Spray Drift Only

Non

listed Species Listed Species Non

listed Species Listed Species Non

listed Species Listed Species

Oilseed

Sunflower, Jojoba, etc (1.7)
Granular F 3 inch

incorporation <0.1 <0.1 0.23 0.30 <0.1 <0.1

Oilseed

Sunflower, Jojoba, etc (1.7) EC3 chemigation 0.73 0.97 1.83 b 2.43 a 0.61 0.81

Oilseed

– Crambe, Rapeseed (canola), etc. group (0.95) EC2 spray with 3 inch

incorporation 0.10 0.14 0.41 0.54 <0.1 <0.1

Oilseed

– Crambe, Rapeseed (canola), etc. group (0.95) G

with 2 inch incorporation <0.1 <0.1 0.30 0.45 <0.1 <0.1

Oilseed

- Safflower

(1.15) granular

with 2 inch incorporation 0.10 0.14 0.41 0.54 <0.1 <0.1

Peanuts granular formulation (1.15)
with 2 inch incorporation 0.10 0.14 0.41 0.54 <0.1 <0.1

Peanuts EC with 2 inch incorporated (1.15) 0.12 0.16 0.50 0.66 <0.1 0.11

Peas EC (0.75) 2 inch incorporation <0.1 0.11 0.32 0.43 <0.1 <0.1

Peas granular formulation (0.76) <0.1 <0.1 0.30 0.40 <0.1 <0.1

Potatoes chemigation

(1.028) 0.44 0.59 1.11 b 1.47 a 0.37 0.49

Potatoes ground (1.028) 0.11 0.15 0.44 0.59 <0.1 <0.1

Soybeans Granular (1.3) 2 inch incorporation <0.1 <0.1 0.47 0.62 <0.1 <0.1

a Bolded R Q exceeds the risk to listed species LOC.

### 64 b Bolded RQ exceeds the risk to non

- listed species LOC



### 6.3.5 Risk to Terrestrial Invertebrates

Bees may be exposed to ethalfluralin via direct applications, drift from boom or aerial spray, or
from residues on plants adjacent to treated fields

. There are no acute or chronic toxicity studies
submitted for larval bees or any acute oral or chronic toxicity studies for adult bees. Therefo re, RQs resulting from contact exposure to ethalfluralin residues are presented in Table 2 9

. The RQs are less than values because the toxicity endpoint did not show any toxicity at the highest
concentrations tested.

Table 29

. Contact RQs for bees that result from applications of ethalfluralin.

Use (application rate lbs a.i./A) Contact Exposure
Alfalfa with low broadcast spray (1.698) <1.1 Cucurbits with low broadcast spray (1.932) <1.2 Potatoes chemigation (1.028) <0.6
Sunflower (1.3) granular, incorporated, chemigation <0.8



### Using calculations from Bee

- Rex modeling, the RQs for contact range from <0. 6 to <1.2 which

, based on absolute value, exceed the Agency’s established acute risk LOC of 0.4. The acute contact toxicity study did not indicate any adverse effects at the highest concentration tested of
51 μ g/bee

, and ethalfluralin i s classified as practically non

- toxic to adult bees on an acute contact exposure basis . The RQs generated are thus the result of non

- definitive toxicity estimate and the high application rates leading EECs that range from 33 μ g/bee to 61 μ g/bee. There is significant uncertainty in these acute RQs as well as the lack of data on chronic effects. The extent of exposure is uncertain as well since pre

- plant timing of application may reduce exposure to pollinators if early in the growing season when plants are not flowering. If the acute oral endpoint was similar t o that of the contact study (>51 μ g/bee) which was practicall y non

- toxic

, RQs would range from <0.05 to <0.1

.



## 7 Risk Description

**7.1 Risk to Non** 

**- Target Aquatic Organisms** 

Ethalfluralin is applied as both a spray (physically incorporated or wetted in) and in granular
form and non

- target aquatic taxa may come into contact with ethalfluralin as a result of spray
drift or runof f. Ethalfluralin may still however reach water bodies due to runoff but the high organic carbon partition coefficient suggests an affinity to bind to sediment thereby decreasing
water column concentrations. Additionally, ethalfluralin concentrations in surface water should be limited by its susceptibility to photolysis in water (half

- life = 6.3 hours) but is somewhat more persistent in turbid waters and in low light environments.

### 65 Aquatic Animals

The acute studies with freshwater and estuarine/marine fish and invertebrates using TGAI
indicate that ethalfluralin is very highly toxic to estuarine/marine fish, freshwater fish, and freshwater invertebrates, and is highly toxic to estuarine/marine invertebrates on acute exposure basis. The EECs result in RQs for freshwater taxa that exceed LOC for acute risk to listed species but not for non

- listed species. The LOC for acute risk to listed estuarine/marine species is only exceeded at the highest concentration modeled and RQs do not exceed the acute risk to

non

- listed LOC

.

To further analyze the potential risk from ethalfluralin use to aquatic species , the AgDrift model was used to predict spray drift deposition, and to determine the distance from the edge of the treated site where the risk from spray drift alone is equal to the LOC for acute risk to listed and

non

- listed aquatic species . It is import ant to recognize, though, that risk from runoff is not considered in this analysis. Elimination of spray drift may reduce the impact to water column taxa as demonstrated by Table 3 0 and Table 3 1

. Effects distances, defined as the distance within which sp ray drift may adversely affect water column taxa ranged from 3 feet to 65 feet for
listed species when using a low boom and high boom

, respectively

, with very fine to fine droplet sizes. Increasing the droplet sizes to fine or medium coarse (median drople t size of 341 μ m)
reduce s the effect distance to 0 ( Table 31 .)

Table 30 . Buffer distances for aquatic taxa using very fine to fine droplet sizes

. Aquatic Animals

Use (application

rate lbs a.i./A) Application
Method EFFECTS DISTANCES Very fine to fine Droplet sized (175 μ m) High boom (1.27 m) Low Boom (0.5 m height)

Non

listed L isted Non

listed L isted

1.69 / 1.7 Ground 0 65 0 7

1.5/1.52 Ground 0 53 0 3

1.15/1.13 Ground 0 33 0 3

1.0/ 0.95 Ground 0 23 0 0

Freshwater Fish LC 50 32 μ g a.i./A;



### Table 31 . Buffer distances for aquatic taxa using fine to medium coarse droplet sizes

. Aquatic Animals

Use (application

rate lbs a.i./A) Application
Method EFFECTS DISTANCES Fine to Medium Coarse Droplet sized (341 μ m) High boom (1.27 m) Low Boom (0.5 m height)

### 66 Non

listed L isted Non

listed L isted

1.69 / 1.7 Ground 0 0 0 0

1.5/1.52 Ground 0 0 0 0

1.15/1.13 Ground 0 0 0 0

1.0/ 0.95 Ground 0 0 0 0

Freshwater Fish LC 50 32 μ g a.i./A;



### The RQs for freshwater fish exceed the chronic risk LOC at application rates of 1 lb ai . / A and higher. The RQs for estuarine/marine fish exceed the chronic risk LOC only at the highest application rate while the RQs for invertebrates in either freshwater or estuarine/marine
environment s d o not exceed the chronic risk LOC at any of the application rate s modeled. Based on the available data, there is potential for acute and chronic risks to aquatic anima ls. Addition al potential for indirect effects to these species also exist because of the risk to aquatic plants (see below). Many aquatic animals are directly and/or indirectly dependent upon aquatic plants for food and/or shelter during various life

- stages.

Ethalfluralin has a high propensity to bind to sediment particles. While this property m a y reduce chronic risk to water column taxa, RQs indicate that freshwater sediment

- dwelling invertebrates may be at risk

. Chronic RQs derived from 10

- day toxicity tests for Hyalella sp . range from 1.3 to
4 and exceed the chronic risk LOC at all of the application rates modeled ; however, t he RQs
based on a 10

- day toxicity test with Chironomous range from 0.13 to 0.4 and d o not exceed the
chronic risk LOC. For both freshwater species, the sub

- chronic 10

- day test is often less sensitive
than the full 28

- day chronic test. Th us these RQs may represent lower

- bound estimates of risk and in order to more fully understand risk to sediment

- dwelling invertebrates, a 28

- day chronic toxicity test may be needed. Additionally, a sediment toxicity test with an estuarine/marine species was not submitted. Until th e s e data are available

, potential risk to estuarine/marine
sediment

- dwelling invertebrates is presumed when they are exposed to ethalfluralin on a chronic
basis.

Aquatic Plants

Based on data and the predicted aquatic exposures, the likelihood of adverse effects on non

- listed species non

- vascular aquatic plants is considered low ; however, at the highest applic ation rate, the RQ for listed non

- vascular plants exceeds the LOC

. Similarly, t he only LOC exceedance for

non

- listed vascular plants is at the highest application rate modeled. R Q values exceed the
LOC for risk to listed vascular plants at all applicat ion rates model ed (RQs 3

– 10; Table 25 )

.

T he contribution of spray drift to the overall risk to aquatic plants may be effectively mitigated by adjusting the boom height and droplet sizes to minimize impacts from spray drift. The distance from aquatic water bodies that ethalfluralin may be applied without adversely impacting aquatic plants is reduced from 59 feet to 7 feet for listed species by lowering the boom height when using the highest application rates ( Table 32 ). This effect distance dropped to zero from increasing the droplet size for all scenarios modeled ( Table 33 ).

### 67 Table 32

. Buffer distances from spray applications with very fine to fine droplet sizes.

Aquatic Plants

Use (application

rate lbs a.i./A) Application

Method Effects Distances Very fine to fine Droplet sized (175

μ m) High boom (1.27 m) Low Boom (0.5 m height)

Non

listed L isted Non

listed L isted

1.69 / 1.7 Ground 0 59 0 7

1.5/1.52 Ground 0 46 0 3

1.15/1.13 Ground 0 26 0 3

1.0/ 0.95 Ground 0 20 0 0

L . gibba LC 50 7.3 μ g a.i./A; NOAEC = 1.7 μ g ai/A



### Table 33 . Buffer distances from spray applications with fine to medium/coarse droplet
sizes

. Aquatic Plants

Use (application

rate lbs a.i./A) Application

Method Effects Distances Fine to Medium Coarse Droplet sized (341 μ m) High boom (1.27 m) Low Boom (0.5 m height)

Non

listed L isted Non

listed L isted

1.69 / 1.7 Ground 0 0 0 0

1.5/1.52 Ground 0 0 0 0

1.15/1.13 Ground 0 0 0 0

1.0/ 0.95 Ground 0 0 0 0

L . gibba LC 50 7.3 μ g a.i./A; NOAEC = 1.7 μ g ai/A



## 7.2 **Risk to Non**

**- Target Terrestrial Organisms** 

The magnitude and duration of adverse effects resulting from acute and chronic exposure via
intake of ethalfluralin residues for birds and mammals is discussed below. The likelihood of exposure is increased given the moderate persistence of ethalfluralin in terrestrial environments (h alf

- lives ranging between 23

– 51 days).

Birds

• Acute Risk (Oral

- based)

### 68 Based on the submitted acute oral toxic ity studies on birds

, ethalfluralin is categorized as practically non

- toxic to birds on an acute oral exposure basis

. A n oral toxicity test with a passerine species was recently provided; based on this study ethalf l uralin is practically non

- toxic to passerines and these data are similar to results for mallard duck ( Anas platyrhynchos ) and bobwhite quail ( Colinus virginianu s ) . Similar to the previous assessment, no risk identified for
birds on an acute oral exposure basis from either granular or emulsifiable concentrat e formulations.

• Chronic Risk (Dietary

- based)

The NOAEC in the chronic bird toxicity studies was 1,000 ppm, but no adverse effects were observed in these studies. The maximum EEC for the proposed uses would be 406 ppm for short grass residues from the alfalfa use. Therefore, even if effects had been o bserved at the 1000 ppm level, chronic risks would not be expected.

Since birds serve as surrogates for terrestrial

- phase amphibians and reptiles, the low likelihood of
adverse effects on birds from either acute or chronic exposure to ethalfluralin exten ds to these
taxa as well.

Mammals

• Acute Risk (Oral

- based)

Ethalfluralin is practically non

- toxic to mammals on an acute oral exposure basis. There a re no

acute risk LOC exceedances for any application rates for either emulsified concentrate or granular
formulations. Therefore, the likelihood of adverse effects to mammals from acute exposure to
ethalfluralin is considered low.

• Chronic Risk ( Dose and Dietary

- based)

D ose

- based R Q values are above the chroni c risk LOC for all size classes of mammals for unincorporated uses on alfalfa, cucurbits, potatoes, and sunflower with application rates of 1.3 lbs. a.i. or higher. RQs range from 1.0 ( for large mammals feeding on short grass exposed to the lowest applica tion rate ) to 3.3 for small mammals feeding on short grass at the highest application rate of 1. 6 9 lbs a.i . / A. For small

- and medium

- sized mammals, RQ values exceed
the chronic risk LOC for short grass, tall grass, broadleaf plants and arthropods ( T able 26 )

. These c hronic risk estimates differ from the previous assessment as a result of a new endpoint (NOAEC = 61 mg/kg

- bw based on reproductive effects; MRIDs 43868313 and 44073701) and higher application rates. To provide a lower bound to the estimates o f risk to mammals resulting from chronic exposure to ethalfluralin , RQs using mean Kenaga residue values in addition to

upper

- bound values were calculated. Using the non

- conservative mean residue values, implying that higher predicted residue val ues are expected half the time

, chronic dose

- based RQs only
exceed the chronic risk LOC of 1.0 for small mammals feeding on short grass at the highest

### 69 application rates modeled ( i.e

., 1.69 lbs ai/A). RQs calculated using mean Kenaga values exceed
the dose

- based c hronic risk LOC only for small mammals feeding on short grass exposed the highest application rate (RQ =1.02). Using mean Kenaga values did not result in any other RQs
that exceeded the LOC. C onsistent with the previous assessment, dietary

- based RQ value s do
not exceed that chronic risk LOC

.

Piscivorous Birds and Mammals

The only LOC exceedance to piscivorous mammals feedi ng on fish containing ethalfluralin
residues i s from chronic exposure of the large river otter (RQ = 1.1) at the highest application

rate of 1.69 lb ai/A . The RQs for the other mammals modeled range from 0.28 for water shrew to 0.7 for small river otter. The RQs for mammalian acute exposure d o not exceed the acute risk
LOC s for any group at the highest concentration rate. The RQs f or birds based on acute and chronic exposure from feeding on fish containing ethalfluralin residues d o not exceed either the
acute or chronic risk LOC s at the highest application rate modeled (1.7 lbs ai/A). The one chronic RQ for mammals that exceed s the LOC at the 1.7 lbs ai/A level d oes not exceed the LOC at the next highest application rate modeled (1.3 lbs ai/A)

. While ethalfluralin’s log K ow 

### is 5.11

, suggesting the potential for ethalfluralin residues to partition in to fatty tissues

, bioconcentration studies suggest that the compound is rapidly metabolized (MRID 41994902 ) and excreted (depurated) once exposure ceases . The BCF ranged from 1330 μ g/L in whole fish to 1560 μ g/L in muscle with a depuration half

- life of three days after exp osure ceased (MRID 41994902). The BCF predicted by the KABAM model ranged from 5889 μ g/L to 6191 μ g/L for small and large fish respectively without any metabolism of ethalfluralin

. Ethalfluralin is expected to depurate by 50% within 3 days once exposure i s stopped making the estimates from the KABAM model highly conservative. The metabolism of ethalfluralin, coupled with low acute toxicity to birds
and mammals

, suggest th e potential for adverse effects from acute or chronic exposure to ethalfluralin resid ues in fish is relatively low except for large mammals where the chronic risk LOC is exceeded at the maximum application rate of 1.69 lbs a.i./A

.

Terrestrial Invertebrates

Results of the acute contact toxicity studies with honey bees demonstrate that e thalfluralin TGAI is practically non

- toxic to beneficial insects on an acute contact exposure basis (LD 50 

### > 51 μg a.i

. / bee)

. While the absolute value of RQs for acute ris k is above the acute risk LOC of 0.4 , all the
actual values are less than values since the acute contact study did not achieve a definitive LD 50



### . Toxicity d ata for chronic exposure of adult and larval honeybees to ethalfluralin as well as acute exposure to larval honeybees are not available; therefore, there is more uncertainty as to the potential risk to these castes from other exposure routes to ethalfluralin

.

Terrestrial Plants

• Runoff and Spray Drift Exposure

Based on the seedling emergence test with terrestrial plants, e thalfluralin is more toxic to

monocots than to dicots . The EC 25 

### and NOAEC in the seedling emergence tests a re 0.0183 lbs
ai/A and 0.00195 lbs ai/A

, respectively

, for monocots versus 0.139 lbs ai/A and 0.105 lbs ai/A

,

### 70 respectively

, for dicots. In contrast to the seedling emergence toxicity test s, ethalfluralin i s less toxic to both monocots and dicots in vegetative vigor tests. The EC 25 

### and NOAEC in the vegetative vigor tests a re 0.212 lbs ai/A and 0.053 lbs ai/A

, respectively

, for monocots and 0.27
lbs ai/A and 0.027 lbs ai/A

, respectively

, fo r dicots. Current t errestrial phytotoxicity da ta and the predicted exposures from the TerrPlant model indicate potential risk to non

- listed and listed
monocot and dicot terrestrial and semi

- aquatic plant species. Monocot RQs range from 2 to 130
in semi

- a quatic areas ; d icot RQs range from 0.2 to 2.4 in semi

- aquatic areas.

To further analyze the potential risk from ethalfluralin use to non

- target plants, the AgDrift model was used to predict spray drift deposition, and to determine the distance from the edge of the treated site where the risk from spray drift alone is equal to the LOC for listed and non

- listed plants. Beyond the se distances, the risk from spray drift alone is not expected to exceed the
LOC

. Table 3 4 and Table 35 provide effects distances for both monocots and dicots respectively using the default droplet size distributions in the AgD RIFT model for ground applications (droplet sizes per the American Society of Agricultural and Biological Engineers or ASABE: very fine to fine for ground appl ications )

. This is done since ethalfluralin labels do not specify droplet size distributions. Groun d applications are modeled with both high and low boom applications (1.27 and 0.5 meters above the ground respectively )

.

For monocots, spray drift effects distances resulting from low boom ground applications range
from 7 feet for non

- listed species at the lowest application rate, to 30 feet for listed species exposed to the highest application rates ( Table 3 4 ) . These spray drift effects distances increase for high boom applications and range from 13 feet for non

- listed species at the lowest application

rate to 82 feet for listed species at the highest application rate.

Table 34

. Modeled spray drift buffer distances needed to mitigate risk to the most sensitive monocot species for applications with very fine to fine droplet size spectrum (ground applications).

Monocot Effects Distances

Use (application

rate lbs a.i./A) Application

Method BUFFER DISTANCES for ground application
Very fine to fine Droplet S ize (175 μ m)
High boom (1.27 m) Low Boom (0.5 m height)

Non

- listed L isted Non

- listed L isted

1.69 / 1.7 Ground 23 82 10 30

1.5/1.52 Ground 20 72 10 26

1.15/1.13 Ground 16 56 7 20

1.0/ 0.95 Ground 13 49 7 20

MONOCOT EC 25 0.212; NOAEC 0.053



### Table 35

. Modeled spray drift buffer distances needed to mitigate risk to the most sensitive dicot species for applications with very fine to fine droplet size spectrum (ground applications)

Dicot Buffer Distances

Buffer distances for ground application

### 71 Use (application

rate lbs a.i./A) Application
Method Very fine to fine Droplet S ize (175 μ m)

High boom (1.27 m) 

### Low Boom (0.5m height)

Non

- listed listed 

### Non

listed listed

1.69 / 1.7 Ground 20 157 

### 7 59

1.5/1.52 Ground 16 141 

### 7 49

1.15/1.13 Ground 13 108 

### 7 39

1.0/ 0.95 Ground 10 95 

### 7 33

DICOT EC 25 0.27; NOAEC 0.027



### For dicots, spray drift effect distances that result from low boom ground applications range from

7 feet for non

- listed species at the lowest application rate to 59 feet for listed species exposed to the highest application rates ( Table 3 5 ) . These effect distances increase for high boom applications and range from 10 feet for non

- listed species at the lowest application rate to 1 57 feet for listed species at the hig hest application rates.

Table 36

. Modeled spray drift buffer distances needed to mitigate risk to the most sensitive monocot species for applications with fine to medium coarse droplet sizes (ground applications).

Monocot Buffer Distances

Use (application

rate lbs a.i./A) Application

Method BUFFER DISTANCES for Coarse droplet sizes for ground application Fine to Medium Coarse Droplet S ize (341 μ m)
High boom (1.27 m) Low Boom (0.5 m height)

Non

- listed L isted Non

- listed L isted

1.69 / 1.7 Ground 7 16 3 10

1.5/1.52 Ground 3 16 3 10

1.15/1.13 Ground 3 13 3 7

1.0/ 0.95 Ground 3 10 3 7

MONOCOT EC 25 0.212; NOAEC 0.053



### Table 37

. Modeled spray drift buffer distances needed to mitigate risk to the most sensitive dicot species for applications with fine to medium coarse droplet sizes (ground applications).

Dicot Buffer Distances

Use (application

rate lbs a.i./A) Application

Method BUFFER DISTANCES for Coarse droplet sizes for ground application Fine to Medium Coarse Droplet S ize (341 μ m)
High boom (1.27 m) Low Boom (0.5 m height)

### 72 Non

- listed L isted Non

- listed L isted

1.69 / 1.7 Ground 3 36 3 20

1.5/1.52 Ground 3 33 3 20

1.15/1.13 Ground 3 23 3 13

1.0/ 0.95 Ground 3 20 3 13

DICOT EC 25 0.27; NOAEC 0.027



### The AgD RIFT model was also run with the coarsest droplet sizes for ground applications in
order to evaluate spray drift buffer distances with larger droplet sizes which may be more common with pre

- emergent herbicide applications and to explore the narrowest buffers possible to mitigate the risks due t o spray drift with the current ethalfluralin uses . The spray drift buffer distances required to mitigate risk for ground applications with fine to medium / coarse droplet
sizes (D V0.5 

### droplet size = 341 microns) with a low boom range from 3 feet for non

- listed monocot species to 10 feet for listed monocot species a t the lowest and highest application rates respectively ( Table 36 )

. The buffer distances required to mitigate risk for grou nd applications with a low boom range from 3 feet for non

- listed dicot species to 20 feet for listed dicot species

a t the lowest and highest application rates

, respectively ( Table 37 ) . Buffer distances are also provided for a high boom scenario as well since labels often say to position height of boom for uniform coverage but to limit drift.



## 8 Uncertainties, Data Gaps, Assumptions, and Limitations

• Environmental Fate

The environmental fate database for ethalfluralin is essentially complete with no major data gaps
identified

. However, some of the aerobic soil metabolism studies have been determined to be supplemental and resolution of the study uncertainties could increase the confidence regarding the persistence of eth alfluralin in aerobic soils. Ov erall, besides these uncertainties, the available data give a largely complete picture of a herbicide with moderate environmental persistence (generally persisting for weeks to months), and moderately high volatility, strong soil / sediment sorption and partitioning into organic material.

• Ecological Effects and Data Gaps.

The ecological effects data are largely complete with the exception of a chronic toxicity test for
estuarine/marine benthic invertebrates and additional pollinator studies

. There is a high degree of uncertainty regarding risk to bees due to a non

- definitive endpoint and no adverse effects at the highest concentration tested in the acute contact study with adult bees. There are no acute or chronic toxicity studies submitted for larval bees or any acute oral or chronic toxicity studies for
adult bees. Additionally risk was identified for freshwater sediment invertebrates but a similar study was not submitted.

### 73 Data gaps for this chemical are listed below: feeding studies for adult bees. In the absence of this data, risk is presumed in these compartments as well.

1. Whole sediment toxicity testing with an estuarine/marine sediment dwelling invertebrate ( Guideline 850.1735)
2. Tier 1 Acute oral toxicity to adult honeybees (Non

- guideline; OECD 213)
3. Tier 1 Acute oral toxicity to larval honeybees (Non

- guideline; OECD 237)

4. Tier 1 Chronic oral toxicity to adult honey bees (Non

- guideline)
5. Tier 1 Chronic oral toxicity to larval honey bees (Non

- guideline)

6. Tier 2 Pollinator feeding/semi

- field study

- The need for these studies is contingent upon
the results of lower tier bee studies (Non

- guideline)

7. Tier 2 P ollen and nectar residue studies

– The need for these studies is contingent upon
the re sults of lower tier bee studies (Non

- guideline)
8. Tier 2 Field testing for pollinators

– The need for field testing is contingent upon the
results of lower tier bee studies (850.3040)

In the absence of this data, risk is presumed in these compartments as we ll.

• A q u a tic Exposure

In general, upper

- bound aquatic exposure estimates for ethalfluralin presented in this risk

assessment are sufficiently conservatively reflect exposure under the most vulnerable conditions in high use areas. Monitoring data taken from sites without intensive ethalfluralin usage suggest low aquatic exposure to dissolved ethalfluralin with concentrations almost always below 0.1 ppb. Also relevant to the level of confidence in the aquatic exposure estimates is the low usage profile

, w hich has been on the decline in recent years

. F or example, the most recent annual usage
level i s estimated to be less than 1.4 million pounds of active ingredient over the entire United States in 2013. The usage is spread over a large portion of U.S. agri cultural lands but at relatively low intensities, with nearly all reporting districts showing overall usage intensities
below about 0.05 lb ai / acre . Aquatic environmental exposures, by contrast were modeled as a 100% of the watershed at maximum label ra tes , making upper bound exposures highly
conservative.

• Terrestrial Exposure

Toxic response is a function of duration and intensity of exposure. For many compounds

, a n oral dose represents a very short

- term high intensity exposure. Although the dose

- based estimates may not reflect reality in that animals do not receive a bolus dose while feeding, it is possible
that a short

- duration, high

- intensity exposure could occur asso ciated with feeding on an agricultural field since many birds may gorge themselves when food items are available. While the dietary

- based estimates may suggest greater “realism,” they too suffer from some uncertainties. Primarily, the dietary

- based appro ach assumes that animals in the field are consuming food at a rate similar to that of confined laboratory animals despite the fact that energy content in food items differs between the field and the laboratory as does the energy requirements of wild and ca ptive animals.

### 74 Other uncertainties with ethalfluralin are related to the representativeness of T

- REX with pre

emergent applications. Risks indicated by T

- REX due to ethalfluralin residues on seeds or arthropods located within treated fields are most certain with its pre

- emergent applications. However, for risks related to broadleaf plants which may be a surrogate to crops, exposure may occur with the uptake of ethalfluralin residu es in the soil as well as any residual residues that are remain in the plant system from the seed after germination. However, it should be noted that the
extent to which ethalfluralin is systemic is unknown. While a rough indicator, ethalfluralin ’s log

K ow 

### of 5.11 suggests some ability for ethalfluralin to remain within the plant material for some period of time. Dinitroaniline herbicides are absorbed somewhat by plant root systems, and to a greater extent by young seedling shoot organs such as the hypoc otyl or coleoptile. Little or no translocation of these herbicides occurs in plants (Parka and Sopa, 1977).

• Other General Uncertainties for Screening Risk Assessments

Routes of Exposure

The screening assessment does not consider ethalfluralin dermal e xposure to terrestrial organisms. The Agency is actively pursuing modeling techniques to account for dermal exposure via direct application of spray and by incidental contact with contaminated vegetation, soil and

water. Additionally, exposure from inhala tion is not assessed. While the compound is moderately volatile, its atmospheric half

- life is limited given its propensity to react with hydroxyl radicals and undergo photolysis.

Age Class and Sensitivity of Effects Thresholds



### It is generally recognize d that test organism age may have a significant impact on the observed sensitivity to a toxicant. A cute toxicity data for fish are collected on juvenile fish

, and aquatic
invertebrate acute toxicity testing is performed on recommended immature age classes

. Similarly, acute dietary testing with birds is also performed on juveniles.

Testing of juveniles may overestimate the toxicity of direct acting pesticides in adults. As juvenile organisms may not have fully developed metabolic systems and may not possess the ability to transform and detoxify xenobiotics equivalent to the older/adult organism. The screening

- level risk assessment has no current provisions for a generally applied method that accounts for this uncertainty. In so far as the av ailable toxicity data may provide ranges of sensitivity information with respect to age class, the risk assessment uses the most sensitive life

stage information as the conservative screening endpoint.

Lack of Effects Data for Amphibians and Reptiles

Cu rrently, toxicity studies on amphibians and reptiles are not required for pesticide registration. Since these data are lacking, the Agency uses fish as surrogates for aquatic

- phase amphibians and birds as surrogates for terrestrial

- phase amphibians and re ptiles. If other species are more or less sensitive to ethalfluralin than the surrogates, risks may be under

- or overestimated, respectively. The Agency is not limited to a base set of surrogate toxicity information in

### 75 establishing risk assessment conclusi ons. The Agency also considers toxicity data on non

standard test species when available. Further research is needed to determine whether, in general, reptiles and terrestrial

- phase amphibians are suitably represented by bird species in assessing risks fo r ethalfluralin and fish are an appropriate surrogate for aquatic

- phase amphibians.

Use of the Most Sensitive Species Tested



### Although the screening

- level risk assessment relies on a selected toxicity endpoint from the most sensitive species tested, it does not necessarily mean that the selected toxicity endpoints reflect sensitivity of the most sensitive species existing in a given environment. The relative position of the most sensitive species tested in the distribution of all possible species is a function of the overall variability among species to a particular chemical. The relationship between the sensitivity of the most sensitive tested species versus wild species (including listed species) is unknown and a source of significant uncertainty. In addition, in the case of listed species, there is uncertainty regarding the relationship of the listed species' sensitivity and the most sensitive species tested.

Sublethal Effects

When assessing acute risk, the screening

- level risk assessment reli es on the acute mortality endpoint as well as a suite of sublethal responses to the pesticide . C onsideration of additional
sublethal data in the effects determination is exercised on a case

- by

- case basis and only after
careful consideration of the nature of the sublethal effect measured and the extent and quality of available data to support establishing a plausible relationship between the measure of effect (sublethal endpoint) and the assessment endpoints. However, the full suite of sublethal effects
fr om valid open literature studies is considered for the characterization purposes within the context of the extent to which the effects can be linked to assessment endpoints of impaired growth, survival or reproduction

.

To the extent to which sublethal ef fects are not considered in this assessment, the potential direct and indirect effects of ethalfluralin on listed species may be underestimated.

Terrestrial Plants

The EC 25 

### and NOAEC values from terrestrial plant studies only assess the effects on initial plant growth and survival. EPA current tests do not provide information on effects to reproduction, fruit formation or fruit yield. However, it is currently assumed that a 25 percent or greater effect on initial plant growth is indicative of subs equent reductions on plant populations, fruit formation and yield. In addition, the number of laboratory test species only account for eight of the 300 known plant families. The range of sensitivity of various plants to a phytotoxicant can be signif icant ly higher than that exhibited in the laboratory because of intraspecie s and interspecies variability , genetic differences in adaptability to environmental stresses, and magnitude and duration of exposure.

### 76 

## 9 Endocrine Disruptor Screening Program

As requir ed by FIFRA and FFDCA, EPA reviews numerous studies to assess potential adverse outcomes from exposure to chemicals. Collectively, these studies include acute, subchronic and chronic toxicity, including assessments of carcinogenicity, neurotoxicity, devel opmental, reproductive, and general or systemic toxicity. These studies include endpoints

, which may be susceptible to endocrine influence, including effects on endocrine target organ histopathology, organ weights, estrus cyclicity, sexual maturation, fert ility, pregnancy rates, reproductive loss, and sex ratios in offspring. For ecological hazard assessments, EPA evaluates acute tests and chronic studies that assess growth, developmental and reproductive effects in different taxonomic groups. As part of registration review for ethalf l uralin, EPA reviewed these data and selected the most sensitive endpoints for relevant risk assessment scenarios from the existing hazard database. However, as required by FFDCA section 408(p), ethalf l uralin is subject to th e endocrine screening part of the Endocrine Disruptor Screening Program (EDSP).

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

- tiered approach to making the statutorily required determinations. Tier 1 consists of a battery of 11 screening assays to identify the potential of a chemical substance to interact with the estrogen, androgen, or thyroid (E, A, or T) hormonal systems. Chemicals that go through Tier 1 screening and are found to have the potential to interact with E, A, or T hormonal systems will proceed to the next stage of the EDSP where EPA will determine which, if any, of the Tier 2 tests are necessary based on the available data. Tier 2 testing is designed to identify any
adverse endocrine

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

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

Under FFDCA section 408(p), the EPA 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 ingredients and 9 inert ingredients. A second list of chemicals
ide ntified for EDSP screening was published on June 14, 2013 12 

### and includes some pesticides scheduled for registration review and chemicals found in water

. Neither of these lists should be construed as a list of known or likely endocrine disruptors. Ethalf l ura lin is not on List 1. For further information on the status of the EDSP, the policies and procedures, the lists of chemicals, future lists, the test guidelines and the Tier 1 screening battery, please visit our website. 13



## 10 Federally Threatened and Endanger ed (Listed) Species of
Concern

Before completing this Registration Review, the Agency will conduct an ecological risk assessment to address the Agency’s obligations under both the Endangered Species Act (ESA) and FIFRA. While the risk assessment supporting this proposed interim Registration Review

12 See http://www.regulations .gov/#!documentDetail;D=EPA

- HQ

- OPPT

- 2009

- 0477

- 0074 for the final second list of

chemicals.

13 http://www.epa.gov/endo/

### 77 decision evaluates risks to species that are not subject to the ESA, EPA is still in the process of conducting a risk assessment for endangered and threatened (listed) species and their designated
critical habitat s for ethalfluralin . In this proposed interim decision, therefore, EPA has not completed effects determinations for listed species associated with the registered uses of
ethalfluralin

.

At this time, EPA has not fully developed its risk assessment process for listed species. In November 2013, the EPA, along with the U.S. Fish & Wildlife Service (USFWS), the National Marine Fisheries Service (NMFS) (collectively, the Services), and the U.S. Department of Agriculture (USDA) released a summary of their joint Interim Approaches for assessing risks to listed species from pesticides. The Interim Approaches were developed jointly by the Agencies in response to the National Academy of Sciences’ (NAS) recommendations and reflect a common approach to risk assessment shared by the Agencies as a way of addressing scientific
differences between the EPA and the Services. The NAS report, available

at http://www.nap.edu/catalog.php?record_id=18344 , outlines rec ommendations on specific scientific and technical issues related to the development of pesticide risk assessments that EPA and the Services must conduct in connection with their obligations under the ESA and FIFRA. The joint Interim Approaches were release d prior to a stakeholder workshop held on November 15, 2013. In addition, the EPA presented the joint Interim Approaches at the December 2013 Pesticide Program Dialogue Committee (PPDC) and State

- FIFRA Issues Research and Evaluation Group (SFIREG) meetings , allowing additional opportunities for stakeholders to comment on the Interim Approaches. As part of a phased, iterative process for developing the Interim Approaches, the Agencies will also consider public comments on the Interim Approaches in connection with the development of upcoming Registration Review
decisions. The details of the joint Interim Approaches are contained in the white paper “Interim Approaches for National

- Level Pesticide Endangered Species Act Assessments Based on the
Recommendations of the National Academy of Sciences April 2013 Report,” dated November 1, 2013, available at http://www.epa.gov/espp/2013/nas.html

.



## 11 Conclusions

Ethalf l uralin is characterized as having low to moderate persistence ; although the compound is subject to relatively rapid photolysis, the conditions (clear, shallow water) favoring this route of abiotic degradation may be limited. The compound is mostly immobile in soil; however, it can move to adjace nt waters via spray drift and runoff of sediment

- bound residues (erosion). While the compound is moderately volatile, its atmospheric half

- life is limited given its propensity to react with hydroxyl radicals and undergo photolysis. Given the limited solu bility of ethalfluralin and its propensity to sorb to organic matter, the compound is expected to be associated with benthic sediments in aquatic systems rather than dispersed in the water column.

When estimates of ethalfluralin exposure in terrestrial and aquatic environments are compared to the available ecotoxicity data, the results of the screening

- level assessment indicate a potential
risk s of concern for both aquatic and terrestrial taxa for current uses of ethalfluralin

. R Q values
exceed the acut e and chronic risk LOC s for freshwater and estuarine fish ( Table 38 ); since fish serve as surrogates for aquatic

- phase amphibians, these risk concerns extend to this taxon as

### 78 well

. Acute R Q values also exceed the acute risk LOC for estuarine/marine invert ebrates and in the absence of data to the contrary, chronic risk is presumed for estuarine/marine sediment

dwelling invertebrates ( Table 38 )

. Risk concerns are also identified for a quatic plants

. In the terrestrial environment, risk concerns are identifi ed for mammals from chronic exposure as well as to terrestrial plants (Table 39).

Ethalfluralin is very highly toxic to aquatic animals. In general, risk quotients for aquatic organisms are calculated considering parent compound alone

. Acute r isk concerns exist for endangered freshwater fish and invertebrates (RQs 0.06

– 0.39) and endangered estuarine / marine fish and invertebrates at the highest application rates (RQs 0.05

- 0.07). Chronic risk concerns exist for freshwater fish from multiple a pplication rates (RQs 1.0 to 3.4) and to estuarine/marine fish at the highest application rate (RQ = 1.13) but not to aquatic invertebrates.
Sediment

- dwelling freshwater invertebrates were also determined to be at risk from chronic exposure to sediment (R Qs 1.3

- 4.0). Risk i s identified to non

- listed aquatic vascular plants only at the highest application rates (RQ = 1.7). Risk to listed vascular plants i s identified for application rates ranging from 1 to 1.7 lbs ai/A with RQs from 3 to 10.4. Risk to li sted non

vascular plants i s only identified at the highest application rate of 1.7 lbs ai/A (RQ = 1.1). Buffers to mitigate risk to listed aquatic plants and animals range from 0 to 65 feet. Ensuring large droplet sizes and low boom heights c ould substan tially reduce impact of spray drift to the aquatic environment though runoff would still contribute to exposure.

For terrestrial wildlife, ethalfluralin is practically non

- toxic to birds, mammals, and terrestrial
insects on an acute exposure basis. Since the time of the problem formulation, the Agency now also requires acute and chronic toxicity studies for larval bees and chronic toxicity studies for
adult bees. While ethalfluralin i s classified as practically non

- toxic to honey bees on an acute

contact exposure basis, the potential impacts of ethalfluralin on adult and larval bees from chronic exposure is uncertain.

No risk is identified for either non

- listed or listed birds from acute or chronic exposure to
ethalfluralin. While dietary

- based RQs ar e below the chronic risk LOC, d ose

- based RQ values
exceed the c hronic risk LOC for mammals for foliar applications of emulsifiable concentrates (RQs ranged from 0.01 to 3.3). RQs for small

- and medium

- sized mammals (15 g and 35 g mammals respectively) exceed the chronic LOC of 1.0 for short grass, tall grass, broadleaf plants for uses on alfalfa, cucurbits, potatoes and sunflower with application rates that ranged from 1 to
1.9 lbs a.i./A. There is also potential risk to piscivorous mammals from chroni c exposure with one LOC exceedance for the large river otter at the highest application rate (RQ 1.1).

Consistent with the herbicidal uses of ethalf l uralin, risks of concern are identified for terrestrial plants for all of the uses/rates evaluated . Ter restrial plant risk was identified for every use of ethalfluralin (non

- listed and listed RQs ranging between <0.1

– 131) ; both runoff and spray drift processes contribute to the overall risk. Buffers required to mitigate the spray drift to terrestrial pla nts range from 7 feet to 157 feet depending on application method and application rate.

The overall risk conclusions for aquatic and terrestrial taxa broken down by each use of
ethalfluralin are presented below in Table 38 and Table 39
, respectively.

### 79 Table 38

. Summary of adverse impacts for aquatic organisms expected from the existing
uses of ethalfluralin.

Adverse Impacts Expected for Aquatic Organisms? (No/Yes: A = Acute, C=Chronic)

Proposed
Use (App.
Rate

- lbs.

a.i./A) Freshwat
er Fish Estuarine/Ma
rine Fish Freshwater Invertebrates(W

ater Column) Estuarine/
Marine
Invertebra

tes (Water Column) Freshwater
and
Estuarine/Ma
rine Benthic
Invertebrates

(Sediment) Freshwater
and
Estuarine/Ma
rine Benthic
Invertebrates (Pore water) Aquat
ic
Plants

Alfalfa,

Beans
with low
broadcast spray EC1

(1.698) Yes AC Yes AC No Yes A Yes No Yes

Alfalfa,

Beans
with chemigatio

n EC3 (1.698) Yes AC Yes AC No Yes A Yes No Yes

Beans granular

(1.69) Yes AC No No Yes A Yes No Yes

Clover 3" incorporat

ed (1.5) No ? No No Yes No Yes

Cucurbits
with low
broadcast spray (1.7) Yes AC Yes AC No Yes A Yes No Yes

Dill ground

spray (1.13) Yes AC No No No Yes No Yes

Lentils,
Mustard granular
formulatio

n 2" incorporati on (0.95) Yes AC No No Yes A Yes No Yes

Oilseed

Sunflower, Jojoba, etc (1.7)
Granular 2
inch incorporati

on Yes AC No No No Yes No Yes

### 80 Adverse Impacts Expected for Aquatic Organisms? (No/Yes: A = Acute, C=Chronic)

Proposed
Use (App.
Rate

- lbs.

a.i./A) Freshwat
er Fish Estuarine/Ma
rine Fish Freshwater Invertebrates(W

ater Column) Estuarine/
Marine
Invertebra

tes (Water Column) Freshwater
and
Estuarine/Ma
rine Benthic
Invertebrates

(Sediment) Freshwater
and
Estuarine/Ma
rine Benthic
Invertebrates (Pore water) Aquat
ic
Plants

Oilseed

Sunflower, Jojoba, etc (1.7)
Granular F

3 inch incorporati

on No No No No Yes No Yes

Oilseed

Sunflower, Jojoba, etc (1.7) EC3 chemigatio

n Yes AC Yes C No Yes A Yes No Yes

Oilseed

– Crambe, Rapeseed (canola),
etc. group

(0.95) EC2 spray

with 2
inch incorporati

on Yes AC No No No Yes No

Oilseed

– Crambe, Rapeseed (canola),
etc. group (0.95) G

with 2
inch incorporati

on No No No No Yes No Yes

Oilseed

Safflower

(1.15) granular
with 2
inch incorporati

on No No No No Yes No Yes

Peanuts granular
formulatio

n (1.15)
with 2
inch incorporati

on Yes AC No No No Yes No Yes

### 81 Adverse Impacts Expected for Aquatic Organisms? (No/Yes: A = Acute, C=Chronic)

Proposed
Use (App.
Rate

- lbs.

a.i./A) Freshwat
er Fish Estuarine/Ma
rine Fish Freshwater Invertebrates(W

ater Column) Estuarine/
Marine
Invertebra

tes (Water Column) Freshwater
and
Estuarine/Ma
rine Benthic
Invertebrates

(Sediment) Freshwater
and
Estuarine/Ma
rine Benthic
Invertebrates (Pore water) Aquat
ic
Plants

Peanuts
EC with 2
inch incorporat ed (1.15) Yes AC No No No Yes No Yes

Peas EC (0.75) 2

inch incorporati

on ? No No No Yes No Yes

Peas granular
formulatio n (0.75) 2

inch incorporati

on ? No No No Yes No Yes

Potatoes chemigatio n (1.028) Yes AC No No No Yes No Yes

Potatoes ground (1.028) Yes AC No No No Yes No Yes

Soybeans
Granular

(1.3) 2
inch incorporati

on Yes AC No No No Yes No Yes



### Table 39

. Summary of adverse impacts for terrestrial organisms expected from the existing
uses of ethalfluralin.

Proposed
Use Adverse Impacts Expected for Terrestrial Organisms? (No/Yes: A = Acute, C=Chronic) (App. Rate

-

lbs. a.i./A) Birds Mammals Piscivorous
Birds Piscivorous

Mammals Terrestrial

Plants Terrestrial

Invertebrates

Alfalfa,
Beans with
low
broadcast

spray EC1

(1.698) No Yes C No Yes C Yes No

### 82 Proposed
Use Adverse Impacts Expected for Terrestrial Organisms? (No/Yes: A = Acute, C=Chronic) (App. Rate

-

lbs. a.i./A) Birds Mammals Piscivorous
Birds Piscivorous

Mammals Terrestrial

Plants Terrestrial

Invertebrates

Alfalfa,
Beans with chemigation EC3 (1.698) No Yes C No Yes C Yes No

Beans granular

(1.69) No No No No Yes No

Clover 3" incorporated (1.5) No No No No Yes No

Cucurbits
with low
broadcast spray (1.7) No Yes C No No Yes No

Dill ground spray (1.13) No Yes C No No Yes No

Lentils,
Mustard granular
formulation

2" incorporation (0.95) No Yes C No No Yes No

Oilseed

Sunflower, Jojoba, etc (1.7)
Granular 2
inch incorporation No No No No Yes No

Oilseed

Sunflower, Jojoba, etc (1.7)
Granular F 3
inch incorporation No No No No Yes No

Oilseed

Sunflower, Jojoba, etc (1.7) EC3 chemigation No Yes C No No Yes No

### 83 Proposed
Use Adverse Impacts Expected for Terrestrial Organisms? (No/Yes: A = Acute, C=Chronic) (App. Rate

-

lbs. a.i./A) Birds Mammals Piscivorous
Birds Piscivorous

Mammals Terrestrial

Plants Terrestrial

Invertebrates

Oilseed

– Crambe, Rapeseed (canola), etc. group (0.95) EC2 spray
with 2 inch incorporation No Yes C No No Yes No

Oilseed

– Crambe, Rapeseed (canola), etc. group (0.95)

G with 2

inch incorporation No No No No Yes No

Oilseed

Safflower

(1.15) granular with
2 inch incorporation No No No No Yes No

Peanuts granular
formulation (1.15) with 2
inch incorporation No No No No Yes No

Peanuts EC
with 2 inch incorporated (1.15) No No No No Yes No

Peas EC (0.75) 2 inch incorporation No No No No Yes No

Peas granular
formulation (0.75) 2 inch incorporation No No No No Yes No

Potatoes chemigation

(1.028) No Yes C No No Yes No

### 84 Proposed
Use Adverse Impacts Expected for Terrestrial Organisms? (No/Yes: A = Acute, C=Chronic) (App. Rate

-

lbs. a.i./A) Birds Mammals Piscivorous
Birds Piscivorous

Mammals Terrestrial

Plants Terrestrial

Invertebrates

Potatoes ground (1.028) No No No No Yes No

Soybeans
Granular (1.3) 2 inch incorporation No No No No Yes No

### 85 

## 12 References

CFR 40. 2007. Code of Federal Regulations 40 Parts 150 to 189. Protection of the Environment. U.S. Government Printing Office.

Fletcher, J.S., J.E. Nellessen, and T.G. Pfleeger. 1994. Literature review and evaluation of the
EPA food

- chain (Kenaga) nomogram, an instrument for estimating pesticide residues on plants. Environ. Tox. Chem. 13:1383

- 1391.

Hoerger, F. and E. E. Kenaga, 1972. Pesticide Residues on Plants: Correlation of Representative Data as a Basis for Estimation of their Magnitude in the Environment. In F. Coulston and F. Korte, eds., Environmental Quality and Safety: Chemistry, Toxicology , and Technology, Georg Thieme Publ., Stuttgart, West Germany, pp. 9

- 28.

Kennedy, J.M., and R.E. Talbert. 1977. Comparative persistence of dinitroaniline type herbicides on the soil surface. Weed Sci. 25(5): 373

- 381.

Parka , S.J. and O. F. Soper . 1977. Th e Physiology and Mode of Action of the Dinitroaniline
Herbicides

. Weed Science 25 : 79

- 87

.

Teske, M. E., & Curbishley, T. B. 2003. AGDISP Version 8.07 User Manual . Prepared For United States Department of Agriculture Forest Service. C.D.I. Technical Note No . 02

- 06. June
2003.

USEPA

, 1998. Guidelines for Ecological Risk Assessment. Risk Assessment Forum, Office of Research and Development, Washington, D.C. EPA/630/R

- 95/002F. April 1998. http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=30759

USEPA

, 2004 Overview of the Ecological Risk Assessment Process in the Office of Pesticide Programs. U.S. Environmental Pr otection Agency, Office of Prevention, Pesticides and Toxic Substances, Office of Pesticide Programs, Washington DC. January 23, 2004.

USEPA

, 2007a. Ecotoxicology (ECOTOX) database. Version 4. Office of Research and Development (ORD) , and the National Health and Environmental Effects Research Laboratory's (NHEERL's) Mid

- Continent Ecology Division (MED)

. http://cfpub.epa.gov/ecotox/ecotox_home.cfm

USEPA

, 2007b. Ecological Incident Information System (EIIS). Environmental Fate and Effects
Division.

USEPA, 2009. Guidance for Selecting Input Parameters in Modeling the Environmental Fate and Transport of Pesticides. U.S. Environmental Protection Agency, Office of Prevention, Pesticides and Toxic Substances, Office of Pesticide Programs, Environmental Fate and Effects Division. Nov. 10, 2009 Online

at: http://www.epa.gov/oppefed1/models/water/input_parameter_guidance.htm

.

### 86 USEPA

, Screening Level Estimates of Agricultural Uses on Ethalfluralin . Biological and
Economic Assessment Division, Office of Pesticide Programs. Dated June 6, 2010.

USEPA, 2014 [a] . Surface Water Concentration Calculator User Manual, Office of Prevention, Pesticides and Toxic Substances, Office of Pesticide Programs, Environmental Fate and
Effects Divisio n. July 1, 2014.

USEPA, 2014 [b] . Guidance for Assessing Pesticide Risks to Bees. USEPA Office of Pesticide Programs, Health Canada Pest Management Regulatory Agency, California Department of Pesticide Regulation.

U.S. Fish and Wildlife Service (USFW S) and National Marine Fisheries Service (NMFS)

, 1998. Endangered Species Consultation Handbook: Procedures for Conducting Consultation and Conference Activities Under Section 7 of the Endangered Species Act. Final Draft.
March 1998.

USGS

, 2010. Nat ional water quality assessment program. Accessed 2 November 2010. http://water.usgs.gov/nawqa/

.

### 87 

## Appendix A. Environmental Fate and Ecological Effects
Data for Ethalfluralin

113101 Ethalfluralin Fate Chemistry Bibliography Final 11/18/13



## 161

- 1 Hydrolysis

MRID Citation Reference

94805 Mosier, J.W.; Sullivan, W.L.; Saunders, D.G. (1976) A Hydrolysis Study on the Herbicide Ethalfluralin. (Unpublished study received Feb 4, 1982 under 1471

- 122; submitted by Elanco Products Co., Div. of Eli Lilly and Co., Indianapolis, Ind.; CDL: 070676

- D)

92062029 Environ Corp. (1990) Dowelanco Phase 3 Summary of MRID
00094805 . A Hydrolysis Study on the Herbicide Ethalfluralin. Prepared by LILLY RESEARCH LABS. 10 p.



## 161

- 2 Photodegradation

- water

MRID Citation Reference

41086401 Carpenter, M.; Fennessey, M. (1988) Determination of the Photolysis of Carbon 14

- Ethalfluralin in Aqueous Solution: ABC Second Amended Final Report #36868. Unpublished study prepared by Analytical Bio

Chemistry Laboratories, Inc. 76 p.

41613916 Carpente r, M.; Fennessey, M. (1988) Determination of the Photolysis Rate of ?carbon 14|

- Ethalfluralin in Aqueous Solution: Final Re

- port (Second Amended). Lab Project Number: 36868. Unpublished study prepared by ABC Labs, Inc. 76 p.

94807 Day, E.W., Jr. (1976) Preliminary Photochemical Studies with the Herbicide Ethalfluralin. (Unpublished study received Feb 4, 1982 under
1471

- 122; submitted by Elanco Products Co., Div. of Eli Lilly and Co., Indianapolis, Ind.; CDL:070676

- F)

94808 Mosier, J.W.; Saunders, D.G . (1980) Photolysis of Ethalfluralin in Aqueous Solution. (Unpublished study received Feb 4, 1982 under
1471

- 122; submitted by Elanco Products Co., Div. of Eli Lilly and Co., Indianapolis, Ind.; CDL:070676

- G)

94810 Saunders, D.G.; Sieck, R.F.; Shuey, E.W. (1982) Vapor Phase Photol

ysis of Ethalfluralin. (Unpublished study received Feb 4, 1982 under
1471

- 122; submitted by Elanco Products Co., Div. of Eli Lilly and Co., Indianapolis, Ind.; CDL:070676

- I)

### 88 

## 161

- 3 Photodegradation

- soil

MRID Citation Reference

94809 Gray, J.E.; Saunders, D.G.; Sieck, R.F.; et al. (1979) Rate of Photolysis of Ethalfluralin on Soil and Glass Plates. (Unpublished study received Feb 4, 1982 under 1471

- 122; submitted by Elanco Products Co., Div. of Eli Lilly and Co., Indianapolis, Ind.; CD L:070676

- H)

41613917 Dykes, J. (1990) Determination of the Photolysis Rate of carbon 14

- Ethalfluralin on the Surface of Soil: Final Report. Lab Project Number 38051. Unpublished study prepared by ABC Labs, Inc. 41 p.



## 162

- 1 Aerobic soil metabolis m

MRID Citation Reference

41613918 Graper, L. (1990) Aerobic Metabolism of carbon 14

- Ethalfluralin in Sandy Loam Soil: Lab Project Number: ABC 0402. Unpublished study prepared by DowElanco. 37 p.



## 835.4100 Aerobic soil metabolism

MRID Citation Reference

48509301 Breaux, N.; Douglas, M.; Chavez

- Green, A.; et al. (2011) Dow AgroSciences Response to US EPAs Ethalfluralin Registration Review Docket EPA

- OPP

2011

- 0094. Project Number: NTB053111/OCR. Unpublished study prepared by Dow AgroSciences, LLC. 29 p.

48915601 Diehl, M. (2003) Degradation of (Carbon 14)

- Ethalfluralin in Three Soils Incubated Under Aerobic Conditions. Project Number: 842133. Unpublished study prepared by RCC Umweltchemie Ag. 92p.



## 162

- 2 Anaerobic soil met abolism

MRID Citation Reference

### 89 41613919 Graper, L. (1990) Anaerobic Metabolism of carbon 14

- Ethalfluralin in Sandy Loam Soil: Lab Project Number: ABC 0403. Unpublished study prepared by DowElanco. 41 p.

94812 Golab, T.; Sassic, K.A.; Wooten, H.L. (1981)14C Ethalfluralin An

aerobic Soil Degradation Study: Experiment No. ABC

- 0111. (Un

published study received Feb 4, 1982 under 1471

- 122; submitted by Elanco Products Co., Div. of Eli Lilly and Co., Indianapolis, Ind.;
CDL:070676

- K)



## 162

- 3 Anaerobic aquatic metab.

MRID Citation Reference

42930102 Lawrence, B.; Mobley, S.; Kesterson, A. (1993) Anaerobic Aquatic Metabolism of (carbon 14)Ethalfluralin: Lab Project Number: 650: 1516: MET91025. Unpublished study prepared by PTRL East, Inc. 172

p.



## 163

- 1 Leach/adsorp/desorption

MRID Citation Ref erence

94814 Saunders, D.G.; Smith, S.K.; Sieck, R.F.; et al. (1982) Soil Ad

- sorption and Desorption of Ethalfluralin: I

- EWD

- 81

- 04. (Unpublished study received Feb 4, 1982 under 1471

- 122; submitted by Elanco Products Co., Div. of Eli Lilly and Co., Indianapolis, Ind.; CDL:070676

- O)

94815 Sullivan, W.; Saunders, D.G. (1976) Aged Leaching Study with the Herbicide Ethalfluralin. (Unpublished study received Feb 4, 1982 under
1471

- 122; submitted by Elanco Products Co., Div. of Eli Lilly and Co., Indianapolis, Ind.; CDL:0 70676

- P)

94816 Gray, J.E.; Loh, A.; Sieck, R.F.; et al. (1982) Laboratory Leaching of Ethalfluralin. (Unpublished study received Feb 4, 1982 under 1471

- 122; submitted by Elanco Products Co., Div. of Eli Lilly and Co., Indianapolis, Ind.; CDL:070676

- Q)

94820 Golab, T.; Sassic, K.A.; Wooten, H.L. (1981) Dissipation of 14C
Ethalfluralin from Water

- hydrosoil Systems Exposed to Natural Environmental Conditions: Experiment No. ABC

- 0082. (Unpublished study received Feb 4, 1982 under 1471

- 122; submitted by El anco Products Co., Div. of Eli Lilly and Co., Indianapolis, Ind.; CDL:070676

- U)

135185 Loh, A.; Sullivan, W. (1978) Adsorption Coefficient of Ethalfluralin in Soil. (Unpublished study received Aug 24, 1978 under 1471

- EX

- 63;

### 90 submitted by Elanco Products Co., Div. of Eli Lilly and Co., Indianapolis, IN; CDL:097325

- K)

41890102 Saunders, D. (1991) Ethalfluralin Aged Soil Leaching Study: Lab Project No. AAC9047. Unpublished study prepared by Dow

- Elanco. 58

p.

42437201 Saunders, D. ; Powers, F. (1987) Adsorption and Desorption of Ethalfluralin on Soil: Lab Project Number: EWD8723. Unpublished study prepared by Lilly Research Laboratories. 74 p.

42437202 Saunders, D.G. and F.L. Powers (1987) Adsorption and Desorption of Ethalfluralin on Soil: Submitted and Performed by DowElanco, Greenfield, Indiana. MRID 42437202



## 163

- 2 Volatility

- lab

MRID Citation Reference

42496601 Kesterson, A. (1992) Laboratory Volatility of ?Carbon 14|Ethalfluralin: Lab Project Number: 579: 1488. Unpublished study prepared by PTRL East Inc. 74 p.



## 164

- 1 Terrestrial field dissipation

MRID Citation Reference

28626 Golab, T.; Sherman, W.E.; Wooten, H.L.; et al. (1980) Radiochemical Studies with 14C Ethalfluralin in Soil and Various Primary and Rotational Crop Plants. (Unpublished study received Feb 22, 1980 under 1471

- EX

- 63; submitted by Elanco Products Co., Div. of Eli Lilly and Co., Indianapolis, Ind.; CDL:099264

- A)

94818 Golab, T.; Sherman, W.E.; Wooten, H.L.; et al. (1980) Radiochemical Studies with 14C Ethalfluralin in Soil and Various Primary and Rotational Crop Plants. (Unpublished study received Feb 4, 1982 under 1471

- 122; submitted by Elanco Products Co., Div. of Eli Lilly and Co., Indianapolis, Ind.; CDL:070676

- S)

94819 Decker, O.D.; Sieck, R.F.; Shuey, E.W. (1982) Ethalfluralin Three

- year Soil Dissipation Studies. (Unpublished study received Feb 4, 1982 under 1471

- 122; submitted by Elanco Products Co., Div. of Eli Lilly and Co., Indianapolis, Ind.;
CDL:070676

- T)

41441 401 Decker, O. (1990) Field Dissipation of Ethalfluralin Following Application of Sonalan to Bare Soil and Seeded with Dry Beans: Lab Project Number: AAC8811. Unpublished study prepared by Dow Elanco. 188 p.

### 91 41613920 Decker, O. (1990) Field Dissipation of Ethalfluralin Following Application of SONOLAN to Bare Soil: Lab Project Number: AAC8811. Unpublished study prepared by DowElanco. 188 p.

41978101 Decker, O.D. (1991) Ethalfluralin Dissipation Study. Laboratory ID No. AAC8712. Unpublished Study Performed and Submitted by DowElanco, Indianapolis, IN.



## 164

- 2 Aquatic field dissipation

MRID Citation Reference

94806 Hamelink, J.L.; Loh, A. (1976) Dissipation of Ethalfluralin from Water. (Unpublished study received Feb 4, 1982 under 1471

- 122; submitted by Elanco Products Co., Div. of Eli Lilly and Co., Indianapolis, Ind.; CDL:070676

- E)

Golab, T. 1981 Dissipation f rom Water Hydrosoil Systems



## 165

- 1 Confined rotational crop

MRID Citation Reference

42930103 O'Neal, S.; Johnson, T. (1993) A Confined Rotational Crop Study with (Carbon 14)

- Ethalfluralin: Lab Project Number: 576: 1509. Unpublished study prepared by PTRL East, Inc. 312 p.



## 165

- 4 Bioaccumulation in fish

MRID Citation Reference

41994902 Woodburn, K.; Hansen, S.; Ball, T.; et al. (1991) Ethalfluralin: Bioconcentration in Rainbow Trout ( Oncorhynchus mykiss ): Lab Project
Number: ES

- DR

- 0233

- 3655

- 1. Unpublished study prepared by Dow Chemical Co., Environmental Tox. & Chem. Research L ab. 44 p.



## Non Guideline Selections

94765 Peloso, T.S.; Kline, R.M.; Sieck, R.F.; et al. (1982) The Effect of Ethalfluralin on the Degradation of Cellulose, Starch, and Protein in Soil: I

- RMK

- 81

- 02. (Unpublished study received Feb 4, 1982 under 1471

- 122 ; submitted by Elanco Products Co., Div. of Eli Lilly and Co., Indianapolis, Ind.;
CDL:070677

- T)

### 92 94766 Kline, R.M.; Knox, J.W.; Sieck, R.F.; et al. (1982) The Effect of Ethalfluralin on Soil Microorganisms. (Unpublished study received Feb 4, 1982 under
1471

- 122; submitted by Elanco Products Co., Div. of Eli Lilly and Co., Indianapolis, Ind.; CDL: 070677

- K)

94767 Kline, R.M.; Knox, T.W.; Zornes, L.L.; et al. (1982) The Effect of Ethalfluralin on Sewage Microorganisms: I

- BSD

- 79

- 12 & I

- BSD

- 80

- 01. (Unpublished study received Feb 4, 1982 under 1471

- 122; submitted by Elanco Products Co., Div. of Eli Lilly and Co., Indianapolis, Ind.; CDL:070677

- L)

94813 Kline, R.M.; Peloso, J.S.; Sieck, R.F.; et al. (1982) Microbial Interactions

-- The Effect of Ethalfluralin on Nitrogen Fixation by Anabaena f los a quae

. (Unpublished study received Feb 4, 1982 under 1471

- 122; submitted by Elanco Products Co., Div. of Eli Lilly and Co., Indianapolis, Ind.;
CDL:070676

- M)

94821 Saunders, D.G.; Sieck, R.F.; Shuey, E.W. (1982) Estimated Water Concentration of Ethalfluralin Following Runoff from a Sonalan

- treated Watershed. (Unpublished study received Feb 4, 1982 under 1471

- 122; submitted by Elanco Products Co., Div. of Eli Lilly an d Co., Indianapolis, Ind.;
CDL:070676

- V)

112920 Saunders, D.; Sieck, R.; Shuey, E. (1982) Estimated Water Concentration of Ethalfluralin following Runoff from a Sonalan

- treated Watershed. (Unpublished study received Sep 2, 1982 under 1471

- 122; submitte d by Elanco Products Co., Div. of Eli Lilly and Co., Indianapolis, IN; CDL:248250

- A)

43659501 MacCoy, D.; Crepeau, K.; Kuivila, K. (1995) Dissolved Pesticide Data for the San Joaquin River at Vernalis and the Sacramento River at Sacramento, California, 1991

- 94: Open File Report 95

- 110. Prepared by U.S. Geological Survey in cooperation with the U.S. EPA and the California Regional Water Quality Control Board; available from U.S. Government Printing Office. 31 p.

43659502 Crepeau, K.; Domagaiski, J.; Ku ivila, K. (1994) Methods of Analysis and Quality

- Assurance Practices of the U.S. Geological Survey Organic Laboratory, Sacramento, California

-- Determination of Pesticides in Water by Solid

- Phase Extraction and Capillary

- Column Gas Chromatography/Mass Spect rometry: Open File Report 94

- 362. Prepared by the U.S. Geological Survey; available from U.S. Government Printing Office. 21 p.

94817 Pikal, M.J. (1976) Vapor Pressure of Ethalfluralin. (Unpublished study received Feb 4, 1982 under 1471

- 122; submitted b y Elanco Products Co., Div. of Eli Lilly and Co., Indianapolis, Ind.; CDL:070676

- R)



## Product Chemistry

- check with RD

63

- 9 Vapor Pressure

MRID Citation Reference

42437202 Decker, O. (1987) Vapor Pressure of Ethalfluralin: Lab Project Number: ODD8721. Unpublished study prepared by Lilly Research Laboratories. 11 p.

### 93 

## 63

- 11 Oct/Water partition Coef.

MRID Citation Reference

41890101 Day, E. (1991) Octanol/Water Partition Coefficient of Ethalfluralin : Lab Project Number: EWD9104. Unpublished study prepared by Lilly Analytical Chemistry Dept. 9

p.



## 63

- 13 Stability

MRID Citation Reference

41613901 Hudson, J.; Smith, C. (1990) Ethalfluralin Technical: Chemical Stability: Lab Project Number: TIL909004. Unpublished study pre

- pared by DowElanco. 6 p.

42929601 Stolz, W. (1993) Determination of the Stability of Ethalfluralin Technical to Selected
Metal s and Metal Ions at Elevated Temperatures: Lab Project Number: FOR93036. Unpublished study prepared by



## Appendix B. Ethafluralin ECO Effects Bibliography

Revised August 2015



## 71

- 1 Avian Single Dose Oral Toxicity

MRID Citation Reference

94760 West, H.C.; Kehr, C.C.; Hamelink, T.L.; et al. (1980) The Toxicity of Compound 94961 (Ethalfluralin) to Bobwhite Quail in a 14

- day Acute Oral Study: Study No. 7012

- 78. (Unpublished study received Feb 4, 1982 under
1471

- 122; submitted by Elanco Products Co. , Div. of Eli Lilly and Co., Indianapolis, Ind.; CDL: 070677

- E)

135181 Elanco Products Co. (1973) Acute Oral Toxicity

-- Mallard Duck: Study WF

- O

3

- 73. (Unpublished study received Aug 24, 1978 under 1471

- EX

- 63; CDL:097325

- D)

135182 Elanco Products Co. (1973) Acute Oral Toxicity

-- Bobwhites: Study Q

- O

- 6

- 73. (Unpublished study received Aug 24, 1978 under 1471

- EX

- 63; CDL:097325

- E)

48915502 Hubbard, P.; Beavers, J. (2012) Ethalfluralin TGAI: An Acute Oral Toxicity Study with the Zebra Finch. Project Number: 379/295, 120326. Unpublished study prepared by Wildlife International, Ltd. 35p.

### 94 92062002 Environ Corp. (1990) Dowelanco Phase 3 Summary of MRID 00094760. The Toxicity of Compound 94961 (Ethalfluralin) to Bobwhite Quail in a 14

- Day Acute Oral Stu dy: Study No. 7012

- 78. Prepared by LILLY RESEARCH LABS. 11 p.



## 850.2100 Avian acute oral toxicity test

MRID Citation Reference

48509301 Breaux, N.; Douglas, M.; Chavez

- Green, A.; et al. (2011) Dow AgroSciences Response to US EPAs Ethalfluralin Registration Review
Docket EPA

- OPP

- 2011

- 0094. Project Number: NTB053111/OCR. Unpublished study prepared by Dow AgroSciences, LLC. 29 p.

48915501 Burri, R. (2002) GF

- 705 Ethalfluralin 333 g/L: Acute Oral Toxicity Test in
the Japanese Quail. Project Number : 841916. Unpublished study prepared by RCC Umweltchemie Ag. 56p.

48915502 Hubbard, P.; Beavers, J. (2012) Ethalfluralin TGAI: An Acute Oral Toxicity Study with the Zebra Finch. Project Number: 379/295, 120326. Unpublished study prepared by Wildlife Inte rnational, Ltd. 35p.



## 71

- 2 Avian Dietary Toxicity

MRID Citation Reference

94761 Kehr, C.C.; Hamelink, T.L.; Brannon, D.R.; et al. (1980) The Toxicity of Compound 94961 (Ethalfluralin) to Bobwhite Quail in a 5

- day Dietary Study: Study No. 7028

- 78. Includes method AVD dated Nov 7, 1978. (Unpublished study received Feb 4, 1982 under 1471

- 122; submitted by Elanco Products Co., Div. of Eli Lilly and Co., Indianapolis, Ind.; CDL:070677

- F)

94762 Karnak, R.E.; Kehr, C.C.; Hamelink, T.L.; et al. (1980) The Toxicity of Compound 94961 (Ethalfluralin) to Mallard Ducks in a 5

- day Dietary Study: Study No. 7030

- 78. (Unpublished study received Feb 4, 1982 under 1471

- 122; submitted by Elanco Products Co., Div. of Eli Lilly and Co., Indianapolis, Ind.; CDL:070677

- G)

92062003 Environ Corp. (1990) Dowelanco Phase 3 Summary of MRID 00094761.
The Toxic ity of Compound 94961 (Ethalfluralin) to Bobwhite Quail in a 5

- Day Dietary Study: Project No. 7028

- 78. Prepared by LILLY RESEARCH LABS. 14 p.

92062004 Environ Corp. (1990) Dowelanco Phase 3 Summary of MRID 00094762. The Toxicity of Compound 94961 (Ethal fluralin) to Mallard Ducks in a 5

- Day Dietary Study: Project No. 7030

- 78. Prepared by LILLY RESEARCH LABS. 14 p.



## 71

- 4 Avian Reproduction

### 95 MRID Citation Reference

94763 Ringer, R.K.; Breslin, W.; Floga, C.; et al. (1981) The Toxicity of Ethalfluralin (El

- 161, Compound 94961) in a One

- generation Reproduction Study with Mallards: Study AO2179. (Unpublished study received Feb 4, 1982 under
1471

- 122; prepared in cooperation w ith Michigan State Univ., submitted by Elanco Products Co., Div. of Eli Lilly and Co., Indianapolis, Ind.; CDL:
070677

- H)

94764 Ringer, R.K.; Breslin, W.; Flaga, C.; et al. (1981) The Toxicity of Ethalfluralin (El

- 161, Compound 94961) in a One

- generatio n Reproduction Study with Bobwhite: Study AO2079. (Unpublished study received Feb 4, 1982 under
1471

- 122; prepared in cooperation with Michigan State Univ., submitted by Elanco Products Co., Div. of Eli Lilly and Co., Indianapolis, Ind.; CDL:
070677

- I)

92062005 Environ Corp. (1990) Dowelanco Phase 3 Summary of MRID 00094764

. The Toxicity of Ethalfluralin (EL

- 161,Compound 94961) in One

- generation Reproduction Study with Bobwhite Quail: Project No. A02079. Prepared by LILLY RESEARCH LABS. 18 p.

92062006 Environ Corp. (1990) Dowelanco Phase 3 Summary of MRID 00094763

. The Toxicity of Ethalfluralin (EL

- 161, Compound 94961) in a One

generation Reproduction Study with Mallards: Study No. A02179. Prepared by LILLY RESEARCH LAB. 18 p.



## 72

- 1 Acute Toxi city to Freshwater Fish

MRID Citation Reference

135183 Sleight, B. (1973) Acute Toxicity of 94961 to Bluegill, Rainbow Trout, and Goldfish ( Carassius auratus ). (Unpublished study received Aug 24, 1978
under 1471

- EX

- 63; prepared by Bionomics, Inc., submitted by Elanco Products Co., Div. of Eli Lilly and Co., Indianapolis, IN; CDL:097325

- F)

41460101 Murray, A.; Meyerhoff, R.; Grothe, D. (1990) Interim Report for An Acute Toxicity Study with Ethalfluralin and Bluegill (Lepomis macrochirus ): Lab Project Number: F01190. Unpublished study prepared by Lilly Research Laboratories. 34 p.

41475001 Murray, A.; Meyerhoff, R.; Grothe, D. (1990) Summary Report for An A cute Toxicity Study with Ethalfluralin and Rainbow Trout ( Salmo gairdneri ): Lab Project Number: F01090 . Unpublished study pre

- pared by Lilly Research Laboratories. 34 p.

41613902 Murray, A. ; Grothe, D. ; Adams, E. (1990) The Acute Toxicity of Ethalfluralin to Bluegill ( Lepomis macrochirus ) in a Flow

- through Test System: Lab Project Number: F02490. Unpublished study prepared by Lilly Research Labs. 2 p.

41613903 Murray, A. ; Grothe, D. ; Adams, E. (1990) The Acute Toxicity of
Ethalfluralin t o Rainbow Trout ( Salmo gairdneri ) in a Flow

- through Test

### 96 System: Lab Project Number: F02390. Unpublished study prepared by Lilly Research Labs. 48 p.

42176401 Murray, A.; Grothe, D.; Adams, E. (1992) The Acute Toxicity of Sonalan (FN 0802), a Formulatio n Containing Ethalfluralin (EL

- 161, Compound 094961), to Bluegill ( Lepomis macrochirus ) in a Static Renewal Test System: Lab Project Number: FO2391. Unpublished study prepared by Lilly Research Labs. 46 p.

41465901 Murray, A.; Meyerhoff, R.; Grothe, D. (1990) Summary Report for An Acute Toxicity Study with Ethalfluralin and Rainbow Trout ( Salmo gairdneri ): Lab Project Number: F01090 . Unpublished study prepared by Lilly Research Laboratories. 34 p.

94769 Hamelink, J.L.; Kehr, C.C.; Adams, E.R.; et al. (1978) The Toxicity of Compound 94961 (El

- 161) to Bluegills in a 96 Hour Soil

- water Static Test: Study No. 2111

- 78. Includes procedure no. 5801633 dated Sep 24, 1976. (Unpublished study received Feb 4, 1982 under 1471

- 122; submitted by Elanco Products Co., Div. of Eli Lilly and Co., Indianapolis, Ind.;
CDL:070677

- N)



## 72

- 2 Acute Toxicity to Freshwater Invertebrates

MRID Citation Reference

94770 Karnak, R.E.; Kehr, C.C.; Hamelink, T.L.; et al. (1980) The Toxic

- ity of Compound 94961 (Ethalfluralin) to Daphnia magna in a 48

- hour Static Study: Study No. 5044

- 78. Includes procedure no. 5801633 dated Sep 24, 1976. (Unpublished study received Feb 4, 1 982 under 1471

- 122; submitted by Elanco Products Co., Div. of Eli Lilly and Co., Indianapolis, Ind.; CDL:070677

- O)

42176402 Grothe, D.; Adams, E. (1992) The Acute Toxicity of Sonalan EC (FN 0802), a Formulation Containing Ethalfluralin (EL

- 161, Compound 094961), to Daphnia magna in a Static

- Renewal Test System: Lab Project Number: CO1191. Unpublished study prepared by Lilly Res earch Labs. 37 p.

92062007 Environ Corp. (1990) Dowelanco Phase 3 Summary of MRID 00094770. The Toxicity of Compound 94961 (Ethalfluralin) to Daphnia magna in a 48

- Hour Static Study: Study No. 5044

- 78. Prepared by LILLY RESEARCH LABS. 12 p.



## 850.1735 W hole sediment: acute freshwater invertebrates

MRID Citation Reference

48915701 Bradley, M. (2011) Ethalfluralin

- 10

- Day Toxicity Test Exposing Midge ( Chironomus dilutus ) to a Test Substance Applied to Sediment Under
Static

- Renewal Conditions. Project Number: 12550/6559, 101243. Unpublished study prepared by Smithers Viscient Laboratories. 99p.

### 97 48915702 Bradley, M. (2011) 10

- Day Toxicity Test Exposing Freshwater Amphipods ( Hyalella azteca ) to Ethalfluralin Applied to Sediment Under
Static

- Rene wal Conditions. Project Number: 12550/6560, 101244. Unpublished study prepared by Smithers Viscient Laboratories. 98p.



## 72

- 3 Acute Toxicity to Estuarine/Marine Organisms

MRID Citation Reference

41613904 Sousa, J. (1990) Ethalfluralin

-- Acute Toxicity to Sheepshead Minnow ( Cyprinodon variegatus ) under Flow

- through Conditions: Lab Project
Number: SLI 90

- 7

- 3404: 1982. 1289. 6108. 505. Unpublished study prepared by Springborn Labs, Inc. 56 p.

41613905 Dionne, E. (1990) Etha lfluralin

-- Acute Toxicity to Eastern Oysters under
Flow

- through Conditions: Lab Project Number: SLI 90

- 07

- 338 1: 1982. 1289. 6107. 504. Unpublished study prepared by Spring

- born Labs, Inc. 54

p.

41613906 Sousa, J. (1990) Ethalfluralin

-- Acute Toxicity t o Mysid Shrimp ( Mysidopsis
bahia ) under Flow

- through Conditions: Lab Project Number: SLI 90

- 7

- 3405: 1982. 1289. 6106. 515. Unpublished study prepared by Springborn Labs, Inc. 56 p.

42889801 Ward, T.; Kowalski, P.; Boeri, R. (1993) Acute Flow

- Through Mol lusc Shell Deposition Test with Ethalfluralin: Lab Project Number: 186

- DO: ES

- 2669. Unpublished study prepared by T. R. Wilbury Labs, Inc. 25 p.



## 72

- 4 Fish Early Life Stage/Aquatic Invertebrate Life Cycle Study

MRID Citation Reference

41613907 Cocke, P.; Mohr, R.; Adams, E. (1990) The Chronic Toxicity of Ethalfluralin

to Daphnia magna in a Flow

- through Life Cycle Test: Lab Project Number: C00390. Unpublished study prepared by Lilly Research Labs. 69 p.

41994901 Murray, A.; Meyerhoff, R.; Adams, E. (1991) The Toxicity of Ethalfluralin to Rainbow Trout ( Salmo gairdneri ) in a 50

- Day Early Life

- Stage Study: Lab Project Number: F02690. Unpublished study prepared by Lilly Research Labs. 108 p.

42930101 Milazzo, D.; Servinski, M .; Kirk, H.; et al. (1993) Ethalfluralin: Evaluation of the Chronic Toxicity to the Daphnid, Daphnia magna Straus: Lab Project
Number: 0233

- 3655: DECO

- ES

- 2666. Unpublished study prepared by Dow Chemical Co. 49 p.

### 98 42041001 Sword, M.C. and J.L. Stratton (1991) Early Life

- Stage Toxicity of RH

- 7592 Technical to Fathead Minnow ( Pimephales promelas ) under Flow

- Through Conditions. ABC Report No. 39266. Rohm and Haas Report No. 91RC

0007. Study Conducted by Analytical Bio

- Chemistry Laboratories, Inc.,
Columbia Mo. Submitted by Rohm and Haas, Spring House, PA. EPA MRID
No. 42041001.



## 850.1300 Daphnid chronic toxicity test

MRID Citation Reference

48509301 Breaux, N.; Douglas, M.; Chavez

- Green, A.; et al. (2011) Dow AgroSciences Response to US EPAs Ethalfluralin Registration Review Docket EPA

- OPP

2011

- 0094. Project Number: NTB053111/OCR. Unpublished study prepared by Dow AgroSciences, LLC. 29 p.

49086902 Urann, K. (2013) Ethalfluralin TGAI: Full Life

- Cycle Toxicity Test with Water Fleas, Da phnia magna , Under Flow

- Through Conditions. Project Number: 14050/6100, 120325. Unpublished study prepared by Smithers Viscient Laboratories. 102p.



## 850.1350 Mysid chronic toxicity test

MRID Citation Reference

49037801 Dinehart, S. (2012) Ethafluralin Technical: Life

- Cycle Toxicity Test of the Saltwater Mysid, Americamysis bahia , Conducted Under Flow

- Through Conditions. Project Number: 68166, 101246. Unpublished study prepared by ABC Laboratories, Inc. 90p.



## 850.1400 Fis h early

- life stage toxicity test

MRID Citation Reference

48689101 York, D. (2011) Ethalfluralin

- Early Life

- Stage Toxicity Test with Sheepshead Minnow ( Cyprinodon variegatus ). Project Number: 12550/6564, 101245. Unpublished study prepared by Smithers Viscient Laboratories. 79p.


## 0.1.1 72

- 7 Simulated or Actual Field Testing

MRID Citation Reference

94769 Hamelink, J.L.; Kehr, C.C.; Adams, E.R.; et al. (1978) The Toxicity of Compound 94961 (El

- 161) to Bluegills in a 96 Hour Soil

- water Static Test: Study No. 2111

- 78. Includes procedure no. 5801633 dated Sep 24, 1976. (Unpublished study received Feb 4, 1982 u nder 1471

- 122; submitted by

### 9 9 Elanco Products Co., Div. of Eli Lilly and Co., Indianapolis, Ind.;
CDL:070677

- N)



## 122

- 1 Seed Germination/Seedling Emergence and Vegetable Vigor

MRID Citation Reference

41613911 Waldrep, T. (1989) Influence of Ethalfluralin on the Germination of Seeds of Ten Crop Plants: Lab Project Number: 61989013. Unpublished study prepared by DowElanco. 13 p.



## 122

- 2 Aquatic plant growth

MRID Citation Reference

41613912 Murray, A.; Grothe, D.; Adams, E. (1990) Toxicity of Ethalfluralin to a Freshwater Green Alga ( Selenastrum capricornutum ) in a Static Test System: Lab Project Number: J01190. Unpublished study prepared by Lilly Research Labs. 44 p.



## 123

- 1 Seed germi nation/seedling emergence and vegetative vigor

MRID Citation Reference

41613913 Waldrep, T. (1990) Influence of Ethalfluralin Pre

- emergence Spray on Seedling Emergence and Vegetative Vigor of Ten Crop Plants: Lab Project Number: 61990001. Unpublished study prepared by Dow

- Elanco. 23 p.

41613914 Waldrep, T. (1989) Influence of Ethalfluralin Post

- emergence Spray on the Vegetative Vigor of Ten Crop Plants: Lab Project Number: 61989014. Unpublished study prepared by DowElanco. 19 p.

42904201 Schwab, D. (1993) Evaluating the Effects of Ethalfluralin on the Vegetative Vigor of Non

- Target Terrestrial Plants: Final Report: Lab Project Number: 40903: FAC

- 40903. Unpublished study prepared by ABC Labs, Inc. 86 p.

No MRID ACC
070677 Thompson, L.L. and P.T. McKamey (1981) Crop Phytotoxicity when Sonalan 3EC was Applied as an Over

- the

- Top Post

- emergence Spray to Seedlings of 12 Crop Species. (Unpublished Study Received Feb 4, 1982
under 1471

- 122, Prepared and Submitted by Lilly Research Laboratories, Division of Eli Lilly and Company, Greenfield, Indiana; CDL:070677).

### 100 

## 850.4225 Seedling emergence, Tier I I

MRID Citation Reference

47874101 Rockliff, C. 2005 and 2008. First Amendment to Final Report: Evaluation of the Phytotoxicity of Sonalan (Ethalfluralin, 333 g ai/L, EC) Seedling Emergence and Seedling Growth Test (Based on OECD Guideline 208 A)

– Northern Europe, 2005. Unpublished study performed by Stockbridge Technology Centre Ltd., North Yorkshire, UK. Laboratory Study No.: STC/05/E276. Study sponsored by Dow AgroSciences LLC, Indianapolis, Indiana. Sponsor Reference No.: EA05T1L001. O riginal study completed December 2005; Amendment to Report completed July 16, 2008.

49385904 Holou, M. (2013) Sonalan HFP (GF

- 1742 360 g a.s./L, EC): Effects on the Seedling Emergence and Growth of Non

- Target Terrestrial Plants (Tier II). Project Number: 68750, 120537, 10/267065. Unpublished study prepared by ABC Laboratories, Inc. 160p.



## 850.4025 Target area phytotoxicity

MRID Citation Reference

47874101 Rockliff, C. (2008) Evaluation of the Phytotoxicity of Sonalan (Enthalfluralin, 333g ai/l, EC) Seedling Emergence and Seedling Growth Test (Based on OECD Guideline 208 A)

- Northern Europe, 2005: (First Amendment to Final Report). Project Number: STC/05/E2 76, EA05T1L001, 22156038. Unpublished study prepared by Stockbridge Technology Centre, Ltd. 100 p.



## 850.4025 Target area phytotoxicity

MRID Citation Reference

47874101 Rockliff, C. (2008) Evaluation of the Phytotoxicity of Sonalan (Enthalfluralin, 333g ai/l, EC) Seedling Emergence and Seedling Growth Test (Based on OECD Guideline 208 A)

- Northern Europe, 2005: (First Amendment to Final Report). Project Number: STC/05/E276, EA05T1L001, 22156038. Unpublished study prepared by Stockbr idge Technology Centre, Ltd. 100 p.



## 850

- 4150 Terrestrial plant toxicity, Tier 1 (vegetative vigor)

MRID Citation Reference

### 101 48509301 Breaux, N.; Douglas, M.; Chavez

- Green, A.; et al. (2011) Dow AgroSciences Response to US EPAs Ethalfluralin Registration Review
Docket EPA

- OPP

- 2011

- 0094. Project Number: NTB053111/OCR. Unpublished study prepared by Dow AgroSciences, LLC. 29 p.

48915901 

### Sonalan HFP (Ethalfluralin, GF

- 1742, 360g as/L EC): Effects on Vegetative Vigor of Non

- Target Terrestrial Pla nts (Tier II).



## 850.4400 Aquatic plant toxicity test using Lemna spp. Tiers I and II

MRID Citation Reference

47866001 Hertl, J.; Breitwieser, H. (2009) Toxicity of Ethalfluralin Technical to the Aquatic Plant Lemna gibba in a Growth Inhibition Test. Project Number: 13052240. Unpublished study prepared by Institut fuer Biologische Analytik und Consulting IBACON. 76 p.

49086901 Softcheck, K. (2013) Ethalfluralin

- 7

- Day Toxicity Test with Duckweed ( Lemna gibba ). Project N umber: 14050/6132, 120866. Unpublished study prepared by Smithers Viscient Laboratories. 105p.



## 141

- 1 Honey bee acute contact

MRID Citation Reference

41613914 Hoxter, K.; Jaber, M. (1990) The Acute Contact of Ethalfluralin to the Honey Bee: Lab Project Number: 151

- 114. Unpublished study prepared by Wildlife International Ltd. 30 p.



## 850.6100 Environmental Chemistry Methods and Associated Independent Laboratory Validation

MRID Citation Reference

49385901 Garcia

- Alix, M. (2012) Independent Laboratory Validaiton of an Analytical Method for the Determination of Ethalfluralin in Soil. Project Number: 120138, CEMS/5394, 071040. Unpublished study prepared by CEM Analytical Services, Ltd. 70p.

49385902 Betson, S. (2012) Validation of an Analytical Method for the Determination of Ethalfluralin in Water. Project Number: 120814, CEMS/5608, 019/2002. Unpublished study prepared by CEM Analytical Services, Ltd. 123 p.

49385903 Amic, S. (2013) Independent Laboratory Validation of an Analytical Method for the Determination of Ethalfluralin in Water by Gas

### 102 Chromatography with Electron

- Impact Mass Spectrometry Detection (GC/MS). Project Number: 130633, S13/01932, CEMS/ 5608. Unpublished study prepared by Eurofins Agroscience Services Chem SAS. 71p.



## 850.7100 Data reporting for environmental chemistry methods

MRID Citation Reference

48915801 Dial, G. (2007) Validation Report for Method GRM 07.07

- Determination of Residues of Benfluralin, Ethalfluralin, and Trifluralin in Soil by Gas Chromatography with Electron

- Impact Mass Spectrometry Detection. Project Number: 071040, GRM/07/07. Unpublished study prepared by Dow AgroSciences, LLC. 51p.



## Non Guideline Selections

94768 Karnak, R.E.; Kehr, C.C.; Hamelink, T.L; et al. (1980) The Toxicity of Compound 94961 (Ethalfluralin) to Earthworms in a 14

- day Soil Incorporated Study: Study No. 6008

- 78. (Unpublished study received Feb 4,
1982 under 1471

- 122; submitted by Elanco Products Co., Div. of Eli Lilly and Co., Indianapolis, Ind.; CDL:070677

- M)

94813 Kline, R.M.; Peloso, J.S.; Sieck, R.F.; et al. (1982) Microbial Interactions

-- The Effect of Ethalfluralin on Nitrogen Fixation by Anabaena f los a quae

. (Unpublished study received Feb 4, 1982 under 1471

- 122; submitted by Elanco Products Co., Div. of Eli Lilly and Co., Indianapolis, Ind.;
CDL:070676

- M)

47899003 Effects of Ethalfluralin Technical on the Development of Sediment

Dwelling Larvae of Chiron omus r iparius in a Water

- Sediment System.

48509301 Breaux, N.; Douglas, M.; Chavez

- Green, A.; et al. (2011) Dow AgroSciences Response to US EPAs Ethalfluralin Registration Review
Docket EPA

- OPP

- 2011

- 0094. Project Number: NTB053111/OCR. Unpublished study prepared by Dow AgroSciences, LLC. 29 p.

### 103 

## Appendix C

. Aquatic Exposure Modeling Inputs and Results

S urface Water Concentration Calculator (SWCC) Output Summary Table (all scenarios)

Scenario ID Crops Represented App.

Date App.

Rate lb/A Peak Yr overall 4

- day 21

- day 60

- day Pore

Water

Peak Pore

Water

21

- day Benthic

Sdmnt.

Peak Benthic

Sdmnt.

21

- day

ILCornSTD Soybean 10

- Jun 1.31 4.61 0.11 0.09 3.17 1.36 0.62 0.19 0.15

KSCornStd Soybeam 10

- Jun 1.31 5.94 0.16 0.12 4.27 2.25 0.93 0.30 0.24

MScornSTD Soybeam 10

- Jun 1.31 4.69 0.20 0.12 3.33 1.90 1.01 0.23 0.17

MSsoybeanSTD Soybeam 10

- Jun 1.31 4.51 0.17 0.11 3.32 1.82 0.89 0.22 0.16

NCcornESTD Soybeam 10

- Jun 1.31 4.54 0.14 0.11 3.54 2.12 0.82 0.28 0.21

OHCornSTD Soybeam 10

- Jun 1.31 4.51 0.12 0.10 3.23 1.39 0.65 0.21 0.16

PAcornSTD Soybeam 10

- Jun 1.31 4.51 0.10 0.09 3.30 1.41 0.56 0.21 0.17

ILCornSTD Soybeam 25

- Jun 1.31 4.52 0.11 0.09 3.29 1.54 0.63 0.22 0.17

KSCornStd Soybeam 25

- Jun 1.31 4.56 0.16 0.11 3.61 1.67 0.81 0.24 0.17

MScornSTD Soybeam 25

- Jun 1.31 4.59 0.20 0.13 3.49 1.96 0.97 0.20 0.16

MSsoybeanSTD Soybeam 25

- Jun 1.31 4.51 0.17 0.11 3.42 1.88 0.89 0.19 0.15

NCcornESTD Soybeam 25

- Jun 1.31 4.60 0.14 0.11 3.60 1.80 0.73 0.21 0.18

OHCornSTD Soybeam 25

- Jun 1.31 5.23 0.12 0.10 3.66 1.67 0.63 0.24 0.18

### 104 PAcornSTD Soybeam 25

- Jun 1.31 4.52 0.10 0.08 3.33 1.34 0.54 0.21 0.16

ILCornSTD Soybeam 10

- Oct 1.31 4.57 0.12 0.10 3.26 1.31 0.61 0.23 0.19

KSCornStd Soybeam 10

- Oct 1.31 5.35 0.15 0.11 3.82 1.60 0.82 0.27 0.22

MScornSTD Soybeam 10

- Oct 1.31 6.51 0.25 0.18 4.71 2.60 1.27 0.37 0.30

MSsoybeanSTD Soybeam 10

- Oct 1.31 6.05 0.22 0.15 4.30 2.34 1.06 0.33 0.27

NCcornESTD Soybeam 10

- Oct 1.31 4.83 0.15 0.12 3.50 1.70 0.82 0.28 0.23

OHCornSTD Soybeam 10

- Oct 1.31 4.51 0.15 0.11 3.36 1.35 0.68 0.23 0.19

PAcornSTD Soybeam 10

- Oct 1.31 4.52 0.11 0.10 3.31 1.41 0.59 0.24 0.20

ILCornSTD Soybeam 25

- Oct 1.31 4.60 0.13 0.10 3.28 1.37 0.63 0.25 0.22

KSCornStd Soybeam 25

- Oct 1.31 4.52 0.14 0.11 3.30 1.74 0.75 0.30 0.26

MScornSTD Soybeam 25

- Oct 1.31 5.42 0.26 0.18 4.21 2.11 1.36 0.38 0.34

MSsoybeanSTD Soybeam 25

- Oct 1.31 5.06 0.22 0.16 3.99 1.96 1.21 0.35 0.29

NCcornESTD Soybeam 25

- Oct 1.31 5.61 0.17 0.12 3.87 2.10 0.94 0.37 0.32

OHCornSTD Soybeam 25

- Oct 1.31 4.51 0.17 0.13 3.43 1.66 0.78 0.29 0.25

PAcornSTD Soybeam 25

- Oct 1.31 4.63 0.12 0.10 3.34 1.37 0.61 0.25 0.22

ND Canola Sunflower 15

- May 1.70 5.91 0.10 0.09 4.11 1.42 0.59 0.29 0.24

ND Canola Sunflower 10

- Jun 1.70 5.85 0.11 0.09 4.12 1.59 0.63 0.28 0.22

ND Canola Sunflower 10

- Oct 1.70 5.85 0.11 0.09 4.08 1.50 0.57 0.30 0.26

ND Canola Sunflower 25

- Oct 1.70 5.85 0.13 0.11 4.13 1.49 0.63 0.32 0.28 50.88 44.68

KS corn Sunflower 15

- May 1.70 6.10 0.20 0.15 4.56 1.90 1.06 0.30 0.25

### 105 KS corn Sunflower 10

- Jun 1.70 7.69 0.21 0.16 5.53 2.92 1.20 0.38 0.31

KS corn Sunflower 10

- Oct 1.70 6.94 0.19 0.14 4.95 2.07 1.06 0.35 0.28

KS corn Sunflower 25

- Oct 1.70 5.85 0.19 0.14 4.27 2.25 0.97 0.38 0.34 60.90 54.38

FL Cucu Cucurbits 15

- Oct 1.70 8.49 0.24 0.15 5.68 2.59 1.33 0.32 0.23 51.52 37.05

FL Cucu Cucurbits 30

- Oct 1.70 12.50 0.25 0.15 8.34 3.55 1.36 0.49 0.33 77.59 52.79

FL Cucu Cucurbits 30

- Oct 0.75 5.52 0.11 0.06 3.68 1.57 0.60 0.15 34.23 23.29 0.00

FL Cucu Cucurbits 30

- Oct 1.13 8.28 0.16 0.10 5.55 2.36 0.91 0.33 0.22 51.68 35.14

NC Peanut Peanut 1

- May 1.15 4.12 0.11 0.09 3.32 1.37 0.57 0.23 0.19 36.252 30.05

MI Beans Dry beans 15

- May 1.69 5.90 0.13 0.11 4.28 1.69 0.71 0.31 0.26 49.29 41.82

ID Npotato Potatoes 10

- May 1.03 3.54 0.07 0.06 2.56 1.01 0.40 0.19 0.16 30.37 25.92

CA alfalfa

- OP Alfalfa,

clover 10

- Jan 1.69 5.81 0.15 0.13 4.44 2.09 0.96 0.40 0.37 63.92 57.88

Maximum 

### 12.50 0.26 0.18 8.34 3.55 1.36 0.49 34.23 77.59 57.88

Minimum 

### 3.54 0.07 0.06 2.56 1.01 0.40 0.15 0.15 23.29 0.00

### 106 

## Surface Water Modeling with the Surface Water Concentration Calculator (SWCC)

1. Sample Input / Output reports generated by SWCC

– Comparison of 1 vs. 4 cm incorp.

– Fl Cucumber Scenario

Table 1. Estimated Environmental Concentrations (ppb) for Ethalfluralin Fl cucumber scenario, Oct. 30 annual applications, comparison of conservative at 1 cm versus incorporated to 4 cm depth assumptions.

EEC Exposure Duration At 1 cm

depth Incorp. To 4 cm depth

Peak (1

- in

- 10 yr) 12.4 8.92

4

- day Avg (1

- in

- 10 yr) 8.29 6.13

21

- day Avg (1

- in

- 10 yr) 3.50 2.72

60

- day Avg (1

- in

- 10 yr) 1.34 1.03

365

- day Avg (1

- in

- 10 yr) 0.244 0.184

Entire Simulation Mean 0.146 0.120

a. Application fully Incorporated to 4 cm.

Estimated Environmental Concentrations for Ethalfluralin are presented in Table 1 for the USEPA standard pond with the FLcucumberSTD field scenario. A graphical presentation of the

year

- to

- year peaks is presented in Figure 1. These values were generated with the Surface Water Concentration Calculator (SWCC Version 1.106). Critical in put values for the model are
summarized in Tables 2 and 3. This model estimates that about 1.2% of Ethalfluralin applied to the field eventually reaches the water body. The main mechanism of transport from the field to the water body is by spray drift (53. 3% of the total transport), followed by runoff (43.6%) and erosion (3.18%). In the water body, pesticide dissipates with an effective water column half

- life of 4.7 days. (This value does not include dissipation by transport to the benthic region; it includ es only processes that result in removal of pesticide from the complete system.) The main source of dissipation in the water column is volatilization (effective average half

- life = 6.2 days) followed by photolysis (22.6 days) and metabolism (104.3 days).

I n the benthic region, pesticide dissipates (5.1 days). The main source of dissipation in the benthic region is metabolism (effective average half

- life = 5.1 days). The vast majority of the pesticide in the benthic region (99.77%) is sorbed to sediment rath er than in the pore water.

### 107 Table 1. Estimated Environmental Concentrations (ppb) for Ethalfluralin.

Peak (1

- in

- 10 yr) 8.92

4

- day Avg (1

- in

- 10 yr) 6.13

21

- day Avg (1

- in

- 10 yr) 2.72

60

- day Avg (1

- in

- 10 yr) 1.03

365

- day Avg (1

- in

- 10 yr) 0.184

Entire Simulation Mean 0.120

Table 2. Summary of Model Inputs for Ethalfluralin.

Scenario FLcucumberSTD

Cropped Area Fraction 1

Koc (ml/g) 3957

Water Half

- Life (days) @ 25 °C 97

Benthic Half

- Life (days) @ 25 °C 4.75

Photolysis Half

- Life (days) @ 40
°Lat 0.263

Hydrolysis Half

- Life (days) 0

Soil Half

- Life (days) @ 25 °C 48.5

Foliar Half

- Life (days) 0

Molecular Wt 333.27

Vapor Pressure (torr) 8.3e

- 5

Solubility (mg/l) 0.3

Table 3. Application Schedule for Ethalfluralin.

Date (Mon/Day) Type Amount (kg/ha) Eff. Drift

10/30 Incorporated to 4

cm 1.91 0.99 0.062

Figure 1. Yearly Peak Concentrations

### 108 a. Application fully placed at a 1 cm depth (Assumption used in EEC calculations for all scenarios)



## Summary of Water Modeling of Ethalfluralin 48asm no vol 4cm

- ap and the USEPA Standard Pond FL cucumber dept 1 cm

Estimated Environmental Concentrations for Ethalfluralin 48asm no vol 4cm

- ap are presented in Table 1 for the USEPA standard pond with the FLcucumberSTD field scenario. A graphical presentatio n of the year

- to

- year peaks is presented in Figure 1. These values were generated with the Pesticide Water Calculator (PWC), Version 1.52. Critical input values for the model are
summarized in Tables 2 and 3.
This model estimates that about 1.4% of Ethalfl uralin 48asm no vol 4cm

- ap applied to the field eventually reaches the water body. The main mechanism of transport from the field to the water body is by runoff (55.6% of the total transport) followed by spray drift (44.4%). In the water body, pesticide di ssipates with an effective water column half

- life of 4.7 days. (This value does not include dissipation by transport to the benthic region; it includes only processes that result in removal of pesticide from the complete system.) The main source of dissipa tion in the water column is volatilization (effective average half

- life = 6.3 days) followed by photolysis (22.6 days) and metabolism (104.3 days). In the benthic region, pesticide dissipates (5.1 days). The main source of dissipation in the benthic region is metabolism (effective average half

- life = 5.1 days). The vast majority of the pesticide in the benthic region (99.77%) is sorbed to sediment rather than in the pore water.

Table 1. Estimated Environmental Concentrations (ppb) for Ethalfluralin 48asm n o vol
4cm

- ap.

Peak (1

- in

- 10 yr) 12.4

### 109 4

- day Avg (1

- in

- 10 yr) 8.29

21

- day Avg (1

- in

- 10 yr) 3.50

60

- day Avg (1

- in

- 10 yr) 1.34

365

- day Avg (1

- in

- 10 yr) 0.244

Entire Simulation Mean 0.146

Table 2. Summary of Model Inputs for Ethalfluralin 48asm no vol 4cm

- ap.

Scenario FLcucumberSTD

Cropped Area Fraction 1

Koc (ml/g) 3957

Water Half

- Life (days) @ 25 °C 97

Benthic Half

- Life (days) @ 25 °C 4.75

Photolysis Half

- Life (days) @ 40
°Lat 0.263

Hydrolysis Half

- Life (days) 0

Soil Half

- Life (days) @ 25 °C 48

Foliar Half

- Life (days) 0

Molecular Weight 333.27

Vapor Pressure (torr) 8.2E

- 5

Solubility (mg/l) 0.3

Henry's Constant 0.0049

Table 3. Application Schedule for Ethalfluralin 48asm no vol 4cm

- ap.

Date (Mon/Day) Type Amount (kg/ha) Eff. Drift

10/30 Placed at a depth
of 4 cm 1.905 .99 .062

Figure 1. Yearly Peak Concentrations

### 110 

## 2. Sample Output Summary files

– SWCC and PWC

SWCC

1. Sunflower and other Oilseed Crop Use Exposure Asssessment

– KScorn Scenario \
File Name: SWCC_ethalfl

- RR2015_KSCorn_Reserv+Pond_Jun10app (rep sunflower)
48.5dASM

- 97dWC_KSCornStd_Pond_Parent.txt

Variable Volume Water Model, SWCC Compatible Version

*******************************************
Performed on: 1/19/2016 at 18:25

Peak 1

- in

- 1 0 = 7.69 ppb
Chronic 1

- in

- 10 = 0.211 ppb Simulation Avg = 0.155 ppb

4

- day avg 1

- in

- 10 = 5.51 ppb

21

- day avg 1

- in

- 10 = 2.90 ppb
60

- day avg 1

- in

- 10 = 1.19 ppb
90

- day avg 1

- in

- 10 = 0.800 ppb

Benthic Pore Water Peak 1

- in

- 10 = 0.381 ppb
Benthic Pore Water 21

- day avg 1

- in

- 10 = 0.302 ppb

### 111 Benthic Conversion Factor = 159.

- Pore water (ug/L) to (total mass, ug)/(dry sed mass,kg)
Benthic Mass Fraction in Pore Water = 0.233E

- 02

YEAR Peak 4

- day 21

- day 60

- day 90

- day Yearly Avg Benthic Pk Benthic 21

- day

1 5.85E+00 4.20E+00 1.50E+00 7.49E

- 01 5.12E

- 01 1.43E

- 01 2.55E

- 01 1.79E

- 01
2 5.85E+00 3.92E+00 1.57E+00 6.79E

- 01 5.47E

- 01 1.45E

- 01 2.14E

- 01 1.66E

- 01
3 5.85E+00 4.00E+00 1.48E+00 6.62E

- 01 4.47E

- 01 1.11E

- 01 2.36E

- 01 1.64E

- 01
4 5.85E+00 4.65E+00 2.09E+00 7.66E

- 01 6.25E

- 01 1.70E

- 01 3.21E

- 01 2.30E

- 01
5 5.85E+00 4.14E+00 1.77E+00 8.12E

- 01 5.68E

- 01 1.57E

- 01 2.36E

- 01 1.81E

- 01
6 7.73E+00 5.56E+00 2.47E+00 9.19E

- 01 6.48E

- 01 1.60E

- 01 3.81E

- 01 2.76E

- 01
7 9.28E+00 6.83E+00 4.35E+00 1.74E+0 0 1.16E+00 3.05E

- 01 5.55E

- 01 4.48E

- 01
8 7.04E+00 4.64E+00 1.79E+00 1.04E+00 7.87E

- 01 2.06E

- 01 2.96E

- 01 2.10E

- 01
9 7.73E+00 5.62E+00 2.65E+00 9.99E

- 01 6.69E

- 01 1.71E

- 01 3.77E

- 01 3.07E

- 01
10 6.59E+00 4.50E+ 00 1.52E+00 5.54E

- 01 3.71E

- 01 1.11E

- 01 2.55E

- 01 1.74E

- 01
11 6.65E+00 4.50E+00 1.58E+00 6.04E

- 01 4.03E

- 01 1.12E

- 01 2.64E

- 01 1.81E

- 01
12 5.85E+00 3.45E+00 1.18E+00 5.31E

- 01 3.85E

- 01 1.12E

- 01 1.86E

- 01 1.25E

- 01
13 5.85E+00 3.60E+00 1.14E+00 8.69E

- 01 6.14E

- 01 2.06E

- 01 2.03E

- 01 1.33E

- 01
14 5.85E+00 4.02E+00 1.38E+00 5.67E

- 01 4.22E

- 01 1.17E

- 01 2.30E

- 01 1.60E

- 01
15 6.36E+00 4.21E+00 1.41E+00 5.08E

- 01 3.47E

- 01 1.02E

- 01 2.35E

- 01 1.60E

- 01
16 5.85E+00 3.54E+00 1.09E+00 4.29E

- 01 2.87E

- 01 7.44E

- 02 1.89E

- 01 1.24E

- 01
17 6.90E+00 4.96E+00 3.19E+00 1.25E+00 9.35E

- 01 2.49E

- 01 4.16E

- 01 3.03E

- 01
18 5.85E+00 3.40E+00 1.57E+00 6.40E

- 01 4.41E

- 01 1.30E

- 01 1.98E

- 01 1.62E

- 01
19 5.85E+00 4.04E+00 1.64E+00 9.01E

- 01 6.59E

- 01 1.75E

- 01 2.36E

- 01 1.73E

- 01
20 5.85E+00 3.90E+00 1.19E+00 4.77E

- 01 3.58E

- 01 1.11E

- 01 2.06E

- 01 1.28E

- 01
21 7.05E+00 5.12E+0 0 2.11E+00 1.07E+00 7.44E

- 01 1.97E

- 01 2.86E

- 01 2.13E

- 01
22 5.85E+00 4.25E+00 1.86E+00 9.42E

- 01 6.79E

- 01 1.75E

- 01 2.73E

- 01 2.25E

- 01
23 5.85E+00 3.90E+00 1.57E+00 6.08E

- 01 4.06E

- 01 1.14E

- 01 2.31E

- 01 1.74E

- 01

2 4 7.33E+00 4.96E+00 2.92E+00 1.20E+00 8.01E

- 01 2.12E

- 01 3.73E

- 01 2.92E

- 01
25 5.85E+00 3.96E+00 1.40E+00 6.82E

- 01 5.18E

- 01 1.58E

- 01 2.27E

- 01 1.59E

- 01
26 5.85E+00 3.87E+00 1.46E+00 6.48E

- 01 5.01E

- 01 1.38E

- 01 2.22E

- 01 1.57E

- 01
27 5.85E+00 4.55E+00 1.85E+00 7.31E

- 01 5.45E

- 01 1.42E

- 01 2.55E

- 01 1.84E

- 01
28 5.85E+00 4.01E+00 1.49E+00 6.71E

- 01 4.57E

- 01 1.16E

- 01 2.21E

- 01 1.51E

- 01
29 5.85E+00 4.03E+00 1.72E+00 8.15E

- 01 6.30E

- 01 1.89E

- 01 2.31E

- 01 1.83E

- 01
30 5.89E+00 3.71E+00 1.51E+00 6.71E

- 01 5.14E

- 01 1.33E

- 01 2.31E

- 01 1.65E

- 01

********************************************************************** ********

********************** Effective compartment halflives averaged over simulation duration:

zero washout 0 water col metab halflife (days) = 186.982755893926 zero hydrolysis 0 photolysis halflife (days) = 30.8989226773054 volatile halflife (days) = 8.71834121390727 total water col halflife (days) = 6.56114624506848

### 112 zero burial 0 benthic metab halflife (days) = 9.15637206697060 zero benthic hydrolysis 0 total benthic halflife (days) = 9.15637206697060

*********************************************************************** Fractional Contribution of Transport Processes to Water body & Total Mass (kg):

Due to Runoff = 0.5039 3.599
Due to Erosion = 0.0000 0.000
Due to Drift = 0.4961 3.543

***********************************************************************
Flow in/o ut Characteristics of Waterbody: Average Daily Runoff Into Waterbody (m3/s) = 8.385461856625667E

- 004 Baseflow Into Waterbody (m3/s) = 0.000000000000000E+000 Average Daily Flow Out of Waterbody (m3/s) = 8.385461856625857E

- 004

********* ************************************************************** Inputs:

3957. = oc partitioning coefficient
97.00 = water column half Life 25.00 = reference temp for water column degradation
4.750 = benthic Half Life 25.00 = Reference temp for benthic degradation 2.000 = Q ten value 0.2630 = photolysis half life 40.00 = reference latitude for photolysis study 0.000 = hydrolysis half life
333.3 = molecular wt
0.8200E

- 04 = vapor pressure 0.3000 = solubility
0.1000E+06 = field area 0.1000E+05 = water body area 2.000 = initial depth 2.000 = maximum depth 2 1=vvwm, 2=usepa pond, 3 = usepa reservoir, 4 = const vol no flow, 5 = const vol
w/flow

F T = burial, else no burial
0.1000E

- 07 = mass transfer coefficient
0.5000 = PRBEN
0.5000E

- 01 = benthic compartment depth 0.5000 = benthic porosity

1.350 = benthic bulk density
0.4000E

- 01 = OC frcation in benthic sediment
5.000 = DOC in benthic compartment
0.6000E

- 02 = benthic biomass

1.190 = DFAC
30.00 = SS

### 113 0.5000E

- 02 = chlorophyll
0.4000E

- 01 = OC frcation in water column SS
5.000 = DOC in water column
0.4000 = biomass in water column
FRACTION AREA CROPPED = 1.00000000000000

PWC Sample Output File (with volatilization invoked)

ariable Volume Water Model, Version 1.02000000000000

*******************************************
Performed on: 2/23/2016 at 13:36

Peak 1

- in

- 10.0 = 7.74 ppb
Chronic 1

- in

- 10.0 = 0.219 ppb Simulation Avg = 0.161 ppb

4

- d avg 1

- in

- 10.0 = 5.60 ppb

21

- d avg 1

- in

- 10.0 = 2.98 ppb
60

- d avg 1

- in

- 10.0 = 1.22 ppb
90

- d avg 1

- in

- 10.0 = 0.825 ppb

1

- d avg 1

- in

- 10.0 = 7.02 ppb
Benthic Pore Water Peak 1

- in

- 10.0 = 0.392 ppb
Benthic Pore Water 21

- d avg 1

- in

- 10.0 = 0.309 ppb
Benthic Conversion Factor = 159.

- Pore water (ug/L) to (total mass, ug)/(dry sed mass,kg)
Benthic Mas s Fraction in Pore Water = 0.233E

- 02

YEAR Peak 4

- day 21

- day 60

- day 90

- day Yearly Avg Benthic Pk Benthic 21

- day

1 5.85E+00 4.28E+00 1.58E+00 7.80E

- 01 5.33E

- 01 1.50E

- 01 2.64E

- 01 1.87E

- 01
2 5.85E+00 3.95E +00 1.61E+00 6.95E

- 01 5.58E

- 01 1.49E

- 01 2.17E

- 01 1.70E

- 01
3 5.85E+00 4.05E+00 1.53E+00 6.80E

- 01 4.58E

- 01 1.15E

- 01 2.42E

- 01 1.69E

- 01
4 5.85E+00 4.72E+00 2.17E+00 7.95E

- 01 6.45E

- 01 1.77E

- 01 3.28E

- 01 2.38E

- 01
5 5.85E+00 4.18E+00 1.82E+00 8.35E

- 01 5.84E

- 01 1.62E

- 01 2.40E

- 01 1.86E

- 01
6 7.84E+00 5.65E+00 2.57E+00 9.57E

- 01 6.73E

- 01 1.67E

- 01 3.93E

- 01 2.86E

- 01
7 9.35E+00 6.97E+00 4.51E+00 1.81E+00 1.21E+00 3.19E

- 01 5.74E

- 01 4.64E

- 01
8 7.04E+00 4.76E+00 1.89E+00 1.07E+00 8.13E

- 01 2.13E

- 01 3.09E

- 01 2.21E

- 01
9 7.78E+00 5.71E+00 2.77E+00 1.05E+00 7.02E

- 01 1.80E

- 01 3.91E

- 01 3.20E

- 01
10 6.67E+00 4.64E+00 1.62E+00 5.89E

- 0 1 3.94E

- 01 1.17E

- 01 2.67E

- 01 1.84E

- 01
11 6.65E+00 4.58E+00 1.64E+00 6.28E

- 01 4.19E

- 01 1.18E

- 01 2.72E

- 01 1.87E

- 01
12 5.85E+00 3.52E+00 1.22E+00 5.49E

- 01 3.97E

- 01 1.17E

- 01 1.92E

- 01 1.30E

- 01
13 5.85E+00 3.72E+ 00 1.22E+00 8.94E

- 01 6.31E

- 01 2.16E

- 01 2.13E

- 01 1.41E

- 01
14 5.85E+00 4.07E+00 1.43E+00 5.85E

- 01 4.35E

- 01 1.22E

- 01 2.35E

- 01 1.65E

- 01
15 6.36E+00 4.28E+00 1.46E+00 5.29E

- 01 3.60E

- 01 1.08E

- 01 2.41E

- 01 1.66E

- 01
16 5.85E+00 3.66E+00 1.16E+00 4.57E

- 01 3.05E

- 01 7.99E

- 02 1.98E

- 01 1.32E

- 01
17 6.97E+00 5.03E+00 3.25E+00 1.27E+00 9.51E

- 01 2.54E

- 01 4.23E

- 01 3.09E

- 01
18 5.85E+00 3.53E+00 1.64E+00 6.68E

- 01 4.60E

- 01 1.36E

- 01 2.08E

- 01 1.70E

- 01

### 114 19 5.85E+00 4.11E+00 1.71E+00 9.33E

- 01 6.80E

- 01 1.81E

- 01 2.43E

- 01 1.81E

- 01
20 5.85E+00 3.96E+00 1.23E+00 4.91E

- 01 3.65E

- 01 1.16E

- 01 2.10E

- 01 1.32E

- 01
21 7.10E+00 5.20E+00 2.19E+00 1.10E+00 7.63E

- 01 2.04E

- 01 2.95E

- 01 2.21E

- 01
22 5.85E+00 4.32E+00 1.95E+00 9.86E

- 01 7.08E

- 01 1.84E

- 01 2.82E

- 01 2.36E

- 01
23 5.85E+00 4.01E+00 1.67E+00 6.45E

- 01 4.31E

- 01 1.23E

- 01 2.43E

- 01 1.84E

- 01
24 7.39E+00 5.06E+0 0 3.01E+00 1.24E+00 8.26E

- 01 2.20E

- 01 3.84E

- 01 3.00E

- 01
25 5.85E+00 4.02E+00 1.46E+00 7.02E

- 01 5.32E

- 01 1.64E

- 01 2.32E

- 01 1.65E

- 01
26 5.85E+00 3.93E+00 1.51E+00 6.67E

- 01 5.13E

- 01 1.42E

- 01 2.28E

- 01 1.63E

- 01

2 7 5.86E+00 4.58E+00 1.88E+00 7.43E

- 01 5.52E

- 01 1.44E

- 01 2.58E

- 01 1.87E

- 01
28 5.85E+00 4.06E+00 1.52E+00 6.86E

- 01 4.66E

- 01 1.19E

- 01 2.25E

- 01 1.55E

- 01
29 5.85E+00 4.09E+00 1.78E+00 8.40E

- 01 6.47E

- 01 1.96E

- 01 2.36E

- 01 1.89E

- 01
30 5.89E+00 3.82E+00 1.60E+00 7.00E

- 01 5.34E

- 01 1.39E

- 01 2.42E

- 01 1.73E

- 01

******************************************************************************

********************** Effective compartment halflives averaged over simulation duration:

zero washout 0 water col metab halflife (days) = 186.982755893926 zero hydrolysis 0 photolysis halflife (days) = 30 .8989226773054 volatile halflife (days) = 11.0708851226495 total water col halflife (days) = 7.81013932066613

zero burial 0 benthic metab halflife (days) = 9.15637206697060
zero b enthic hydrolysis 0 total benthic halflife (days) = 9.15637206697060

*********************************************************************** Fractional Contribution of Transport Processes to Waterbody & Total Mass (kg):

Due to Runoff = 0.5042 3.603
Due to Erosion = 0.0000 0.1157E

- 26
Due to Drift = 0.4958 3.543

*********************************************************************** Flow in/out Characteristics of Waterbody : Average Daily Runoff Into Waterbody (m3/s) = 8.391564781242711E

- 004 Baseflow Into Waterbody (m3/s) = 0.000000000000000E+000 Average Daily Flow Out of Waterbody (m3/s) = 8.391564781242700E

- 004

**************************************** ******************************* Inputs:

3957. = oc partitioning coefficient
97.00 = water column half Life 25.00 = reference temp for water column degradation
4.750 = benthic Half Life 25.00 = Reference temp for benthic degradation 2.000 = Q ten value

### 115 0.2630 = photolysis half life 40.00 = reference latitude for photolysis study 0.000 = hydrolysis half life
333.3 = molecular wt
0.8200E

- 04 = vapor pressure 0.3000 = solubility
0.1000E+06 = field area 0.1000E+05 = water body area 2.000 = initial depth 2.000 = maximum depth 2 1=vvwm, 2=usepa pond, 3 = usepa reservoir, 4 = const vol no flow, 5 = const vol
w/flow

F T = burial, else no burial
0.1000E

- 07 = mass transfer coefficient
0.5000 = PRBEN
0.5000E

- 01 = benthic compartment depth 0.5000 = benthic porosity

1.350 = benthic bulk density
0.4000E

- 01 = OC frcation in benthic sediment
5.000 = DOC in benthic compartment
0.6000E

- 02 = benthic biomass

1.190 = DFAC
30.00 = SS
0.5000E

- 02 = chlorophyll
0.4000E

- 01 = OC frcation in water column SS
5.000 = DOC in water column
0.4000 = biomass in water column
FRACTION AREA CROPPED = 1.00000000000000

Sample SWCC Input Files

2. Sunflower and other Oilseed Crop Use Exposure Asssessment

– KScorn Scenario

File Name: SWCC_ethalfl

- RR2015_KSCorn_Reserv+Pond_Jun10app (rep sunflower)
48.5dASM

- 97dWC.SWI

Ethalfluralin

1

True 3957,,, 97,,, 25,,, 4.75,,, 25,,,

### 116 0.263,,, 40,,, 0,,, 48.5,,, 25, 0,,, 333.27,,,
8.2E

- 5,,, 0.3,,, 0,0, 0,0, 0,0, 0,0, 0,0, 0,0,

2

1 10,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, 6,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, 1.905,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
False

,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, 4,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, ,,,,,,,,,,,

,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, .99,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, .062,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, .99,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, .0661,,,,,,,,,,,,,,,,,,,,,,,,,

,,,,,,,,,,,,,,,,,,,,,,,,, 1,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, True

,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

KSCornStd
C: \ Models \ Inputs \ Metfiles \ W13996.dvf

True,True,False,False,False False,30
False
10000

### 117 12
4.2
4.8

1E

- 08
0.5
0.05
0.5
1.35
0.04
5
0.006
1.19
30
0.005
0.04
5
0.4
False 1.0,1.0

10
5
9

7
20
10 90,300
100
0.25

1
0.72
0.36
17.5
0

0.37
0.58
0.5
3
3.4
600

4 10,8,8,66, 1.3,1.3,1.3,1.29,

### 118 0.364,0.364,0.274,0.32, 0.139,0.139,0.224,0.229, 1.74,1.74,1.3,0.87, 100,4,4,33,

,,,,

,,,,

False
29 10,16,1,16,1,16,1,16,1,16,1,5,16,1,16,1,16,1,16,1,16,1,16,1,10,16,20,25,1,,,,,,,,,,,,,,,,,,,,,,,, 5,5,6,6,7,7,8,8,9,9,10,10,10,11,11,12,12,1,1,2,2,3,3,4,4,4,4,4,5,,,,,,,,,,,,,,,,,,,,,,,, 88,88,88,88,88,88,88,88,88,88,88,88,88,94,94,94,94,94,94,94,94,94,94,94,94,94,94,94,94,,,,,,,,,,,,

,,,,,,,,,,,, .189,.195,.151,.122,.101,.107,.115,.122,.130,.150,.178,. 099,.106,.096,.084,.087,.089,.038,.038,.0 39,.039,.040,.042,.044,.090,.094,.160,.184,.189,,,,,,,,,,,,,,,,,,,,,,,, .023,.023,.023,.023,.023,.023,.023,.023,.023,.023,.023,.023,.023,.023,.023,.023,.023,.023,.023,.0 23,.023,.023,.023,.023,.023,.023,.023,.023,.02 3,,,,,,,,,,,,,,,,,,,,,,,, 2.0,1.55,0.266, 0.1,0,
False

3. Cucurbits Use Exposure Asssessment

– FL Cucumber Scenario (Oct. 30 application date)

File Name: SWCC_ethalfl

- RR2015_FLcucu_Reserv+Pond_Oct30 app (rep Cucurb)48.5dASMH2O97d.SWI

Ethalfluralin B te st
1

True 3957,,, 97,,, 25,,, 4.75,,, 25,,, 0.263,,, 40,,, 0,,, 48.5,,, 25, 0,,, 333.27,,,
8.2E

- 5,,, 0.3,,,

### 119 0,0, 0,0, 0,0, 0,0, 0,0, 0,0,

2

1 30,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, 10,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, 1.905,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
False

,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, 4,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, ,,,,,,,,,, .99,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, .062,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, .99,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, .0661,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, 1,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, True

,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

FLcucumberSTD
C: \ Models \ Inputs \ Metfiles \ W12844.dvf

True,True,False,False,False False,30
False
10000

12
4.2
4.8

1E

- 08
0.5
0.05
0.5
1.35
0.04

### 120 5
0.006
1.19
30
0.005
0.04
5
0.4
False 1.0,1.0

16
10
5

12
10

12 50,30
80
0.15

1
0.78
0
32.5
0

0.03
0.2

1

4

1
600
3 10,62,28, 1.65,1.65,1.7, 0.073,0.073,0.211, 0.023,0.023,0.091, 1.16,1.16,0.174, 100,31,7,

,,,

,,,

False

### 121 27 16,1,16,1,16,1,16,1,16,1,16,1,16,1,15,16,25,1,16,1,16,1,10,16,1,16,1,,,,,,,,,,,,,,,,,,,,,,,,,, 10,11,11,12,12,1,1,2,2,3,3,4,4,5,5,5,5,6,6,7,7,8,8,8,9,9,10,,,,,,,,,,,,,,,,,,,,,,,,,, 87,87,87,87,91,91,91,91,91,91,91,91,91,91,91,91,91,91,91 ,91,91,91,91,91,91,91,91,,,,,,,,,,,,,,,,,,,,,,

,,,, .683,.715,.743,.768,.793,.813,.830,.846,.859,.870,.878,.881,.881,.880,.836,.849,.938,.840,.572,.2 85,.177,.162,.210,.291,.422,.547,.636,,,,,,,,,,,,,,,,,,,,,,,,,, .011,.011,.011,.011,.011,.011,.011,.011,.011 ,.011,.011,.011,.011,.011,.011,.011,.011,.011,.011,.0 11,.011,.011,.011,.011,.011,.011,.011,,,,,,,,,,,,,,,,,,,,,,,,,, 2.0,1.55,0.266, 0.1,0,
False

,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

### 122 

## Appendix D . Sample TREX Files

Upp er Bound Kenaga Residues For RQ Calculation

Chemical Name: Ethalfluralin

Use 24

Formulation 0
Application Rate 1.69 lbs a.i./acre

Half

- life 35 days
Application Interval 0 days
Maximum # Apps./Year 1
Length of Simulation 1 year Variable application rates? no



## Endpoints



## Avian Redwinged blackbird LD50 (mg/kg

- bw) 2000.00

Bobwhite quail LC50 (mg/kg

- diet) 5000.00

Bobwhite quail NOAEL(mg/kg

- bw) 0.00

Mallard duck NOAEC (mg/kg

- diet) 1000.00



## Mammals LD50 (mg/kg

- bw) 5000.00 LC50 (mg/kg

- diet) 0.00 NOAEL (mg/kg

- bw) 61.00 NOAEC (mg/kg

- diet) 1220.00



## Dietary

- based EECs (ppm) Kenaga

Values

Short Grass 405.60

Tall Grass 185.90 Broadleaf plants 228.15 Fruits/pods/seeds 25.35 Arthropods 158.86

### 123 

## Dose

- based EECs

(mg/kg

- bw) Avian Classes and Body Weights (grams)

small mid large

20 100 1000

Short Grass 461.94 263.42 117.94

Tall Grass 211.72 120.73 54.05 Broadleaf plants 259.84 148.17 66.34 Fruits/pods 28.87 16.46 7.37 Arthropods 180.93 103.17 46.19
Seeds 6.42 3.66 1.64



# Dose

- based RQs

(Dose

- based EEC/adjusted LD50) Avian Acute RQs Size Class (grams)

20 100 1000

Short Grass 0.27 0.12 0.04

Tall Grass 0.13 0.06 0.02 Broadleaf plants 0.15 0.07 0.02 Fruits/pods 0.02 0.01 0.00 Arthropods 0.11 0.05 0.02
Seeds 0.00 0.00 0.00



# Dietary

- based RQs

(Dietary

- based EEC/LC50 or NOAEC) RQs

Acute Chronic

Short Grass 0.08 0.41

Tall Grass 0.04 0.19 Broadleaf plants 0.05 0.23 Fruits/pods/seeds 0.01 0.03 Arthropods 0.03 0.16

Mammalian Cl asses and Body weight
(grams)

### 124 

## Dose

- Based EECs

(mg/kg

- bw) 15 35 1000

Short Grass 386.71 267.27 61.97

Tall Grass 177.24 122.50 28.40 Broadleaf plants 217.52 150.34 34.86 Fruits/pods 24.17 16.70 3.87 Arthropods 151.46 104.68 24.27
Seeds 5.37 3.71 0.86



# Dose

- based RQs

(Dose

- based EEC/LD 50 or NOAEL) small medium large

Chronic Chronic Chronic

Short Grass 2.88 2.46 1.32

Tall Grass 1.32 1.13 0.61 Broadleaf plants 1.62 1.39 0.74 Fruits/pods 0.18 0.15 0.08 Arthropods 1.13 0.97 0.52

Seeds 0.04 0.03 0.02



# Dietary

- based RQs

(Dietary

- based EEC/LC50 or NOAEC) Mammal RQs

Acute Chronic

Short Grass #DIV/0! 0.33

Tall Grass #DIV/0! 0.15 Broadleaf plants #DIV/0! 0.19 Fruits/pods/seeds #DIV/0! 0.02 Arthropods #DIV/0! 0.13



## Appendix E . Sample TerrPlant Files

Table 1. Chemical Identity.

Chemical Name Ethalfluralin

### 125 PC code 113101

Use alfalfa Application Method Spray

Application Form Ground Application Solubility in Water (ppm) 0.3

Table 2. Input parameters used to derive EECs.

Input Parameter Symbol Value Units

Application Rate A 1.3 y

Incorporation I 2 none
Runoff Fraction R 0.01 none

Drift Fraction D 0 none

Table 3. EECs for Ethalfluralin . Units in y.

Description Equation EEC
Runoff to dry areas (A/I)*R 0.0065

Runoff to semi

- aquatic areas (A/I)*R*10 0.065 Spray drift A*D 0 Total for dry areas ((A/I)*R)+(A*D) 0.0065

Total for semi

- aquatic areas ((A/I)*R*10)+(A*D) 0.065

Table 4. Plant survival and gro wth data used for RQ derivation. Units are in y.
Seedling Emergence Vegetative Vigor Plant type EC 25 NOAEC EC 25 NOAEC

Monocot 0.0183 0.00195 0.212 0.053

Dicot 0.139 0.105 0.27 0.027

Table 5. RQ values for plants i n dry and semi

- aquatic areas exposed to Ethalfluralin through runoff and/or spray drift.*

Plant Type Listed Status Dry Semi

- Aquatic Spray Drift

### 126 Monocot non

- listed 0.36 3.55 <0.1

Monocot listed 3.33 33.33 <0.1

Dicot non

- listed <0.1 0.47 <0.1

Dicot listed <0.1 0.62 <0.1
*If RQ > 1.0, the LOC is exceeded, resulting in potential for risk to that plant group.

### 127 

## Appendix F. Sample KABAM Files

Table 11. Estimated concentrations of Ethalfluralin in ecosystem components.

Ecosystem Component Total
concentration

(μg/kg

- ww) Lipid
normalized
concentration

(μg/kg

- lipid) Contribution
due to diet (μg/kg

- ww) Contribution
due to respiration (μg/kg

- ww) Water (total)* 13 N/A N/A N/A Water (freely dissolved)* 13 N/A N/A N/A Sediment (pore water)* 0 N/A N/A N/A Sediment (in solid)** 52 N/A N/A N/A Phytoplankton 72,690 3634482 N/A 72,689.64 Zooplankton 56,920 1897330 2,222.15 54,697.75

Benthic Invertebrates 61,641 2054701 5,607.68 56,033.37

Filter Feeders 40,471 2023530 3,612.90 36,857.70

Small Fish 94,288 2357210 24,355.55 69,932.85

Medium Fish 115,675 2891869 48,653.60 67,021.15 Large Fish 174,190 4354746 107,805.01 66,384.81 * Units: μg/L; **Units: μg/kg

- dw

Table 12. Total BCFand BAF values of Ethalfluralin in aquatic trophic levels.

Trophic Level Total BCF (μg/kg

- ww)/(μg/L) Total BAF (μg/kg

- ww)/(μg/L) Phytoplankton 6184 5815 Zooplankton 4407 4554
Benthic
Invertebrates 4578 4931

Filter Feeders 3010 3238

Small Fish 5889 7543

Medium Fish 5889 9254 Large Fish 6191 13935

Table 13. Lipid

- normalized BCF, BAF, BMF and BSAF values of Ethalfluralin in aquatic trophic levels.

Trophic Level BCF (μg/kg

lipid)/(μg/L) BAF (μg/kg

lipid)/(μg/L) BMF (μg/kg

lipid)/(μg/kg

lipid) BSAF (μg/kg

lipid)/(μg/kg

OC) Phytoplankton 309225 290759 N/A 2782 Zooplankton 146889 151786 0.52 1452

### 128 Benthic Invertebrates 152604 164376 1.13 1573

Filter Feeders 150475 161882 1.11 1549

Small Fish 147235 188577 1.19 1804

Medium Fish 147235 231350 1.31 2214 Large Fish 154769 348380 1.51 3334

Table 14. Calculation of EECs for mammals and birds consuming fish contaminated by Ethalfluralin. Wildlife Species Biological Parameters EECs (pesticide intake) Body Weight

(kg) Dry Food Ingestion Rate (kg

- dry

food/kg

bw/day) Wet Food Ingestion Rate (kg

- wet

food/kg

bw/day) Drinking
Water
Intake (L/d) Dose
Based (mg/kg

bw/d) Dietary
Based (ppm)

Mammalian

fog/water shrew 0.02 0.140 0.585 0.003 36.074 61.64

rice rat/star

- nosed
mole 0.1 0.107 0.484 0.011 31.659 65.43

small mink 0.5 0.079 0.293 0.048 33.929 115.67

large mink 1.8 0.062 0.229 0.168 26.510 115.67

small river otter 5.0 0.052 0.191 0.421 22.102 115.67

large river otter 15.0 0.042 0.157 1.133 27.371 174.19

Avian sandpipers 0.0 0.228 1.034 0.004 67.9830 65.75

cranes 6.7 0.030 0.136 0.211 9.9245 73.03

rails 0.1 0.147 0.577 0.010 45.0152 77.96

herons 2.9 0.040 0.157 0.120 13.9553 88.66

small osprey 1.3 0.054 0.199 0.069 23.0669 115.67

white pelican 7.5 0.029 0.107 0.228 18.5864 174.19

Table 15. Calculation of toxicity values for mammals and birds consuming fish contaminated by Ethalfluralin.

Wildlife Species Toxicity Values
Acute Chronic

### 129 Dose
Based (mg/kg

bw) Dietary
Based (mg/kg

- diet) Dose Based (mg/kg

- bw) Dietary
Based (mg/kg

diet)
Mammalian fog/water shrew 10499.51 N/A 128.09 1220

rice rat/star

- nosed
mole 7122.50 N/A 86.89 1220

small mink 4695.52 N/A 57.29 1220

large mink 3320.24 N/A 40.51 1220

small river otter 2571.84 N/A 31.38 1220

large river otter 1954.18 N/A 23.84 1220

Avian sandpipers 1440.86 0.00 N/A 1000

cranes 3446.50 0.00 N/A 1000

rails 1738.73 0.00 N/A 1000

herons 3039.67 0.00 N/A 1000

small osprey 2679.19 0.00 N/A 1000

white pelican 3505.31 0.00 N/A 1000

Table 16. Calculation of RQ values for mammals and birds consuming fish contaminated by Ethalfluralin.

Wildlife Species Acute Chronic
Dose
Based Dietary
Based Dose Based Dietary
Based

Mammalian fog/water shrew 0.003 N/A 0.282 0.051

rice rat/star

- nosed
mole 0.004 N/A 0.364 0.054

small mink 0.007 N/A 0.592 0.095

large mink 0.008 N/A 0.654 0.095

small river otter 0.009 N/A 0.704 0.095

large river otter 0.014 N/A 1.148 0.143

### 130 Avian sandpipers 0.047 #DIV/0! N/A 0.066

cranes 0.003 #DIV/0! N/A 0.073

rails 0.026 #DIV/0! N/A 0.078

herons 0.005 #DIV/0! N/A 0.089

small osprey 0.009 #DIV/0! N/A 0.116

white pelican 0.005 #DIV/0! N/A 0.174



## Appendix G. Risk Quotient Method

Risk characterization integrates the results of the exposure and ecotoxicity data to evaluate the likelihood of adverse ecological effects. The means of this integration is called the quotient method. Risk quotients (RQs) are calculated by dividing expos ure estimates by acute and chronic ecotoxicity values.

RQ = EXPOSURE/TOXICITY

RQs are then compared to OPP's levels of concern (LOCs). These LOCs are used by OPP to analyze potential risk to nontarget organisms and the need to consider regulatory ac tion. The criteria indicate that a pesticide used as directed has the potential to cause adverse effects on nontarget organisms. LOCs currently address the following risk presumption categories: (1)
acute risks

- regulatory action may be warranted in add ition to restricted use classification, (2)
acute restricted use

- the potential for acute risk is high, but may be mitigated through restricted use classification, (3) acute endangered species

- endangered species may be adversely affected, and (4) chroni c risk

- the potential for chronic risk is high regulatory action may be warranted. Currently, EFED does not perform assessments for chronic risk to plants, acute or chronic risks to insects, or chronic risk from granular/bait formulations to birds or m ammals.

The ecotoxicity test values (measurement endpoints) used in the acute and chronic risk quotients are derived from required studies. Examples of ecotoxicity values derived from short

term laboratory studies that assess acute effects are: (1) LC 50 

### (fish and birds), (2) LD 50 

### (birds and mammals), (3) EC 50 

### (aquatic plants and aquatic invertebrates) and (4) EC 25 

### (terrestrial plants). Examples of toxicity test effect levels derived from the results of long

- term laboratory studies that assess chronic effects are: (1) LOAEL or LOAEC (birds, fish, and aquatic invertebrates) and (2) NOAEL or NOAEC (birds, fish and aq uatic invertebrates). For birds, mammals, fish and aquatic invertebrates the NOAEL or NOAEC generally is used as the ecotoxicity test value in assessing chronic effects, although other values may be used when justified. Risk presumptions and the correspo nding RQs and LOCs, are tabulated below.

### 131 Table X . Risk presumptions for terrestrial animals based on risk quotients (RQ) and levels of concern (LOC).

Risk Presumption RQ LOC

Birds

Acute Risk EEC 1 /LC 50 or LD 50 /ft 2 or LD 50 /day 3 0.5

Acute Restricted Use EEC/LC 50 or LD 50 /ft 2 or LD 50 /day (or LD 50 < 50 mg/kg) 0.2

Acute Endangered Species EEC/LC 50 or LD 50 /ft 2 or LD 50 /day 0.1

Chronic Risk EEC/NOAEC 1

Wild Mammals

Acute Risk EEC/LC 50 or LD 50 /ft 2 or LD 50 /day 0.5

Acute Restricted Use EEC/LC 50 or LD 50 /ft 2 or LD 50 /day (or LD 50 < 50 mg/kg) 0.2

Acute Endangered Species EEC/LC 50 or LD 50 /ft 2 or LD 50 /day 0.1

Chronic Risk EEC/NOAEC 1

1 abbreviation for Estimated Environmental Concentration (ppm) on avian/mammalian food items

2 mg/ft 2

3 mg of toxicant consumed/day

LD 50 * wt. of bird

LD 50 * wt. of bird

Table 2. Risk presumptions for aquatic animals based on risk quotients (RQ) and levels of concern (LOC).

Risk Presumption RQ LOC

Acute Risk EEC 1 /LC 50 or EC 50 0.5

Acute Restricted Use EEC/LC 50 or EC 50 0.1

Acute Endangered Species EEC/LC 50 or EC 50 0.05

Chronic Risk EEC/NOAEC 1

1 EEC = (ppm or ppb) in water

Table 3. Risk presumptions for plants based on risk quotients (RQ) and levels of concern (LOC).

Risk Presumption RQ LOC

Terrestrial and Semi

- Aquatic Plants

Acute Risk EEC 1 /EC 25 1

Acute Endangered Species EEC/EC 05 or NOAEC 1

Aquatic Plants

Acute Risk EEC 2 /EC 50 1

Acute Endangered Species EEC/EC 05 or NOAEC 1

1 EEC = lbs ai/A

2 EEC = (ppb/ppm) in water

### 132 

## Appendix H. Environmental Degradates of Ethalfluralin

Proposed Pathway for Aerobic Degradation of Ethalfluralin (Source: MRID 41613918 )

CHEMICAL NAMES OF DEGRADATES

ET

- 2E = N

- Ethyl

- 2,6

- dinitro

- 4

- (trifluoromethyl)benzenamine

ET

- 4 = N2

- Ethyl

- N2

- (2

- methyl

- 2

- propenyl)

- 3

- nitro

- 5

- (trifluoromethyl)

- 1,2

- benzenediamine

ET

- 2M = N

- (2

- Methyl

- 2

- propenyl)

- 2,6

- dinitro

- 4

- (trifluoromethyl)benzenamine

ET

- 20 = 2,6

- Dinitro

- 4

- (trif l u o romethyl)phenol

ET

- 15M = 2

- Methy l

- 7

- nitro

- 5

- (trifluoromethyl)benzimidazole

ET

- 28E = 2,2’

- Azoxybis( α,α,α

- trifluoro

- 6

- nitro

- N

- ethyl

- p

- toluldine)

ET

- 17E = 1

- Ethyl

- 7

- nitro

- 5

- (trifluoromethyl)benzimidazole

M1 = 2,3,4,5

- Tetrahydro

- 5

- ethyl

- 3

- methylene

- 6

- nitro

- 8

- (trifluoromethyl)

- 1H

- 1,5

- benzodiazepine

### 133 Proposed Pathway for Anaerobic Degradation of Ethalfluralin (Source: MRID 41613919)

CHEMICAL NAMES OF DEGRADATES (not previously listed)

ET

- 3 = 2,6

- Dinitro

- 4

- (trifluoromethy l )benzenamine

ET

- 5E = N 2



### - Ethyl

- 3

- nitro

- 5

- (trifluoromethy l )

- 1,2

- benzenediamine

ET

- 7 = N 2



### - Ethyl

- N 2



### - (2

- methyl

- 2

- propenyl

- 5

- (trifluoromethyl)

- 1,2,3

- benzenetriamine

ET

- 13E = 1

- Ethyl

- 2

- (1

- methylethenyl)

- 7

- nitro

- 5

- ( t ri fluo ro methy l )benzimidazole

M2 = 1

- Ethyl

- 2

- (1

- methylethenyl)

- 5

- (trifluoromethyl)

- 1H

- benzimidazol

- 7

- amine