UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON D.C., 20460



## ..**.~**



### PC Codes: 128959, 128968

DP Barcode: 418561

Date: September 8, 2014

MEMORANDUM

SUBJECT:

FROM:

REVIEWED

BY: 

### Problem Formulation for the Ecological Risk and Drinking Water Exposure Assessments to be Conducted in Support of the Registration

Review for Fluroxypyr-MHE

Nicholas Mastrota, Ph.D., Wildlife Biologist 

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Rochelle F. H. Bohaty, Ph.D., Chemist

## ~~ Environmental Risk Branch 3

Environmental Fate and Effects Division (7507P)

Melissa Panger, Ph.D., Senior Biologist

James Hetrick, Ph.D., Senior Advisor

Environmental Risk Branch 3

Environmental Fate and Effects Division (7507P) 

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THROUGH: Dana Spatz, !Jranch Chief

Environmental Risk Branch

## 3,**<=:::~:5~~~2~~~:­** Environmental Fate and Effects Division (7507P)



### TO: Neil Anderson, Branch Chief Benjamin Askin, Chemical Review Manager

Risk Management and Implementation Branch 1

Pesticide Re-Evaluation Division (7508P)

### 2



# Contents

I. Executive summary ............................................................................................................. ...... 3

II. Introduction .................................................................................................................. ....... 4

1. Previous Ecological Risk Assessments ............................................................................. 4

2. Drinking Water Exposure Assessments ............................................................................ 5

3. Clean Water Act Programs ................................................................................................ 6

III. Stressor Source and Distribution ...................................................................................... 6

A. Description of Stressors ..................................................................................................... 6

B. Mechanism of Action ........................................................................................................ 7

C. Overview of Pesticide Usage ............................................................................................ 8

D. Environmental Fate and Transport .................................................................................. 16

IV. Receptors ..................................................................................................................... ...... 23

1. Effects to Aquatic Organisms .......................................................................................... 23

2. Effects to Terrestrial Organisms ...................................................................................... 27

B. Ecological Incidents ........................................................................................................ 32

C. Exposure Pathways of Concern ....................................................................................... 34

V. Analysis Plan ................................................................................................................. .......... 34

A. Ecological Risk Assessment ............................................................................................ 34

1. Stressors of Concern ........................................................................................................ 34

2. Measures of Exposure ..................................................................................................... 35

3. Measure of Effects ........................................................................................................... 35

4. Integration of Exposure and Effects ................................................................................ 35

5. Endangered Species Assessments ................................................................................... 36

6. Endocrine Disruptor Screening Program ........................................................................ 37

B. Drinking Water ................................................................................................................ 37

VI. Preliminary Identification of Data Gaps ........................................................................ 37

A. Environmental Fate ......................................................................................................... 37

B. Ecological Effects ............................................................................................................ 39

VII. References (general) ......................................................................................................... 45 APPENDIX A. Bibliography ..................................................................................................... 47 APPENDIX B. Inputs and Outputs from the SIP and STIR Models ................................... 60

### 3



## I. EXECUTIVE SUMMARY

The Environmental Fate and Effects Division (E FED) has completed the preliminary problem formulation for the ecological ri sk and drinking water exposure a ssessments to be conducted as part of the registration review of the herb icide fluroxypyr-MHE (PC code: 128968). The problem formulation describes the methods planned to be used during the completion of drinking water and ecological risk assessments in support of re gistration review, and pr ovides an overview of the environmental fate, ecological effects, and potential risks associat ed with the use of fluroxypyr-MHE. Uncertainties unique to the ri sk assessment of fluroxypyr-MHE are also

discussed.

A bibliography that includes th e study classification for all of the studies that have been submitted to support the registration of fluroxypyr-MHE is included in APPENDIX A . EFED recommends requesting the following additional da ta to better understand the environmental fate and ecological effects to support the cu rrent registrations of fluroxypyr-MHE:

 Environmental Chemistry Methods and Asso ciated Independent Laboratory Validation (Guideline 850.6100.) – Several different met hods have been provided to support various laboratory and field studies; however, none of the soil methods are sensitive enough to detect fluroxypyr-MHE or flur oxypyr acid at levels of toxi cological concern (0.00083 lb a.e./A). The lowest detecti on limit reported for fluroxypyr ac id in soil is 3 μg/kg (0.007 a.e. lb/A). An independent laboratory validation has not been submitted for the environmental chemistry method in water.

 

### Compost Study (non-guideline) – a con centration based compost study (MRID 45833601) has been submitted that examined th e dissipation of fluroxypyr acid; however, this study has several deficiencies including: 1) no methods (includi ng an independent lab validation) or control spike an alysis were provided to suppor t the analytical procedures used in the study, 2) recoveries were variable, 3) dilution due to sample withdrawal and consolidation of multiple samples was not adequately described, and 4) a comparison of the composting method with typical compos ting practices was not provided. Additional

data are needed to address these deficien cies or a new study should be submitted to address the fate of fluroxypyr-MHE and fl uroxypyr acid fate in composted materials.

 Seedling Emergence, Guideline 850.4100 and Vegetative Vigor, Guideline 850.4150, with representative typical end-use products.

 Tier 1 studies for assessing toxicity to bees, including a honey bee acute oral study (OECD 213), a honey bee chronic oral study, and a honey bee chronic larval study. These studies should be performed with flur oxypyr-MHE TGAI. Depending on the results of these studies, additional higher-tiered honey bee testing may be required.

### 4



## II. INTRODUCTION

1. Previous Ecological Risk Assessments

Four previous ecological risk assessments ha ve been completed for the registration of fluroxypyr-MHE for use on agricultural crops. C onclusions of the previous assessments are

summarized in Table II.1 and Table II.2



### .

Table II.1. Summary of Previous Risk A ssessments Conducted on Fluroxypyr-MHE

Use Reference Application Rate Assessed (lbs a.i./A) Taxa for which risk was

identified

Rice D396342 0.34 (single application)

0.56 (annual) Aquatic invertebrate, aquatic plants, terrestrial plants

Millet D336179 0.50 (annual rate) Terrestrial plants

Pome Fruit D336179 0.50 (annual rate) Saltwater invertebrates and terrestrial plants

Onion (to control voluntary potatoes) D314020 0.25(single application)

0.375 (annual) Terrestrial plants

Wheat, Barley, and Oats D236845

D231718 0.125 (single application) Terrestrial plants

Uncultivated areas D236845

D231718 0.25 (single application) Terrestrial plants



### Table II.2. Risk Concerns Identified for 

### Fluroxypyr-MHE in Previous Assessments

Birds Mammals Terr.

Plants Terr.

Inverts Fish BCF Aquatic

Inverts Aquatic

Plants Groundwater

Contamination Persistence Degradates

of Concern

-- -- √

-- -- -- √ √ x x x √ = at least one LOC has been exceeded in previous assessments; “--“ = LOCs have not been exceeded in past assessments; x indicates issues raised in previous assessment that may not be directly related to an LOC exceedance.



### The most recent ecological risk assessment conducted for fluroxypyr-MHE was for a new use on rice (D396342). The assessment was completed in 2013 for a direct application of fluroxypyrMHE to flooded rice paddies. The maximum single application rate of 0.34 lb a.i./A and a maximum annual application rate of 0.56 lb a.i./A was assessed. The assessment concluded that

acute and chronic risks were less than the EPA’s levels of concern (LOC) for fish, birds, and mammals. For aquatic invertebrates, the risk quot ient (RQ) for acute ri sk was below the LOC, but the RQ for chronic risk exceeded the LOC. For plants, the RQs for terrestrial plants and algae exceeded the LOC for non-endangered species, and th e RQs for all terrestrial and aquatic plants exceeded the LOC for endangered species. An a ddendum to this risk assessment (USEPA, 2014) estimated that water needs to be held in the pa ddy for between 1 and 18 days for the total toxic residues in water to dissipate to a concentr ation below the LOCs for algae and aquatic invertebrates. There is uncertainty in this estimate because fluroxypyr-MHE hydrolysis is accelerated by suspended sediment in the flood wate r as well as the uncertainty in the aquatic invertebrate chronic toxicity data for the primary transformation pr oduct, fluroxypyr acid.

### 5

A Section 3 risk assessment conducted for pome fruit and millet 1 

### determined that use on pome

fruit at the maximum annual rate of 0.50 lb a.i./A poses an acute ri sk to saltwater invertebrates,

whereas use on millet did not. The assessment fou nd that use on both millet and pome fruit poses a risk to non-target terrestrial pl ants, but did not pose a risk to aquatic plants. Two Section 3 risk assessments were conducted for use of fluroxypyr-MHE on 1) wheat, barley, and oats, 2 

### 2)

uncultivated areas 2 

### , and 3) onions to cont rol voluntary potatoes 3 

### . The rates assessed for these uses are presented in Table II.1 . In these assessments, no risk to non-target organisms were predicted except for risk to non- target terrestrial plants.

2. Drinking Water Exposure Assessments

Several drinking water assessments (DWA) have been completed for fluroxypyr-MHE including

for use on onion 4 

### , rangeland and permanent grass pastures 5 

### , sorghum 6 

### pome fruit and millet 7 

### , and

rice 8 

### . A summary of the estimated drinking water concentrations (EDWCs) reported in these assessments are provided in Table II.3. The highest EDWCs were reported for use on rice followed by rangeland. EDWCs presented for the rice use are expected to be highly conservative as the model used (Tier I Rice Model) to estim ate the pesticide concentrations in the water column is an instantaneous pa rtitioning model and does not cons ider transformation. Moreover, there are no known drinking water intakes that reside within a rice paddy or immediately adjacent to the paddy discharge point. Therefore, some dilution is expected to occur prior to a drinking water intake.

1 Angier, J., Jenkins, F., EFED Risk Assessment for the Proposed New Uses of Fluroxypyr on Pome Fruit, Proso Millet, and Pearl Millet

. October 24, 2007 (DP 336179)

2 Mastrota, F. N., Effland, W. R., Review for Section 3 Registration of Fluroxypyr Acid (128959) and Fluroxypyr – MHE (1289685) March 31, 1998 ( DPs 236845 and 231718)

3 Jenkins, F., Abdel-Saheb, I., Ecological Risk Assessment Evaluating Fluroxypyr MHE(PC Code 128968) and Fluroxypyr Acid (PC Code 128959) for the Proposed New Use on Onion

. May 30, 2006 (DP 314020)

4 Abdel-saheb, I, Jenkins, F. Section 18 Emergency Exemption Request for Use of Fluroxypyr on Onions in

Colorado April 14, 2004 (PC 128959; DP 300165) Abdel-saheb, I, Drinking Water Assessment for Fluroxypyr on Onion

, February 15, 2006 , (PC128968; DP314020)

5 Abdel-saheeb, I, Drinking Water Assessment for Fluroxypyr on Rangeland and Permanent Grass Pasture

, August 13, 2003

, (PC 128968; DP292471).

6 Abdel-saheeb, I, Drinking Water Assessment for Fluroxypyr on Sorghum, March 5, 2003 , (PC128968; DP28831)

7 Angier, J. Drinking Water Assessment for Fluroxypyr New Uses on Pome Fruit and Millet

, September 26, 2007

, (PC 128968; DP336179)

8 Parker, R. Drinking Water Assessment for New Use of Fluroxypyr in Rice (Paddies)

, August 21, 2012 , (PC 128968; DP 396343)

### 6

Table II.3. Summary of Previous Drinking Water Assessments

Assessment Estimated Surface Water Concentrations (μg/L) a Estimated

Groundwater

Concentrations b (μg/L) 1-in-10 year

Peak 1-in-10 year

Annual Mean 30 Year Mean

Millet 15.4 0.2 0.07 0.03

Pome Fruit 19.0 0.3 0.09 0.05 Rangeland 32.9 3.3 1.8 0.05 Onion, Sorghum 18.2 2.5 1.5 0.8

Rice c 540 0.06

a. PCA (0.8) Adjusted PRZM-EXAM S estimated concentrations

b. SCI-GROW estimated concentrations

c. Estimate was derived using the Tier I Rice Model



### 3. Clean Water Act Programs

Neither fluroxypyr-MHE (nor fluro xypyr acid) have been identified as a cause of impairment for any water bodies listed as impaired unde r section 303(d) of the Clean Water Act. 9 

### No Total Maximum Daily Load (TMDL) criteria ha ve been developed for either compound. 10 

### The EPA invites submission of water quality data for this pesticide. To the extent possible, data should conform to the quality standards in Appendix A of the OPP Standard Operating Procedure: Inclusion of Impaired Water Body and Other Water Quality Data in O PP’s Registration Review Risk Assessment and Management Process 11 

### in order to ensure the data can be used quantitatively or qualitatively in pesticide risk assessments.

Aquatic benchmarks have been established for fluroxypyr acid and fluroxypyr-MHE and are

available online. 12 

### Any data submitted or otherwise locate d as part of the registration review process may be used to update aqua tic life benchmarks if applicable.



## III. STRESSOR SOURCE AN D DISTRIBUTION

A. Description of Stressors

The chemical structures of fluroxypyr-MHE along with the chemical identification and select physical-chemical properties are provided in

Table III

. 1. While fluroxypyr-MHE is the registered pe sticide active ingredient, fluroxypyr acid (PC Code: 128959) is rapidly formed in the environment via microbial mediated deesterification of fluroxypyr-MHE. Fluroxypyr acid and flur oxypyr-MHE are both highly toxic to dicotyledonous plants (MRID 44094902). Two addi tional major environmental transformation products of fluroxypyr-MHE are known: 4-amino- 3,5-dichloro-6-fluoro- 2-pyridinol (fluroxypyrDCP) and 4-amino-3,5-dichloro-6-f luoro-2-methoxypyridine (fluroxypyr-MP).

9 http://iaspub.epa.gov/tmdl_waters10/attains_nation_cy.cause_detail_303d?p_cause_group_id=885

10 http://iaspub.epa.gov/tmdl_waters10/attains_nation.tmdl _pollutant_detail?p_pollutant_group_id=885&p_pollutant_ group_name=PESTICIDES

11 http://www.epa.gov/oppsrrd1/regist ration_review/water_quality_sop.htm

12 http://www.epa.gov/oppefed1/ecori sk_ders/aquatic_life_benchmark.htm

### 7

Both fluroxypyr-MHE and fluroxypyr acid were consid ered as residues of toxicological concern in prior drinking water and ecological risk assessments. Base d on available data, fluroxypyr-DCP and fluroxypyr-MP have been shown to be much le ss toxic to terrestrial and aquatic plants.

In addition to the technical grade products [fluroxypyr-MHE (35935-74, 62719-285, 35935-53 and 35935-77), there are 68 fluroxypyr-MHE regist ered end-use products. All except six (Reg. No. 42750-204; 62719-577; 62719-586; 66330-385; 66330-387; 71368-87) products contain multiple active ingredients (see APPENDIX B) including other herbicides such as 2,4-D, dicamba, triclopyr, MCPA, picloram, and clopyrali d. It should be noted that there are four restricted use products (see APPENDIX B).

Table III.1. Chemical Identification and Phys ical Chemical Properties of Fluroxypyr-MHE

Common

Chemical Name Fluroxypyr-MHE; Fluroxypyr 1-methylheptyl ester; Fluroxypyr-meptyl

Company Code 128968

Chemical Name ((4-amino-3,5-dichloro-6-fluoro-2-pyridinyl) oxy) acetic acid 1-methylheptyl ester 2-Octanyl [(4-amino-3,5-dichloro-6 -fluoro-2-pyridi nyl)oxy]acetate CAS Registry

Number 81406-37-3

Chemical

Structure N O Cl NH 2 Cl

F O

O 4

Molecular

Formula C 15 H 21 C l2 FN 2 O 3

Smiles Notation CCCCCCC(C)OC(=O)CO C1=NC(=C(C(=C1Cl)N)Cl)F

Molecular Mass (g/mol) 367.24

Vapor Pressure (25 °C) 1.0 x 10 -8 mm Hg at 20 oC (MRID 47600903)

Water Solubility 0.155 mg/L (pH not specified; MRID 47540703) Henry’s Law

Constant 5.75 X 10 -7 atm m 3 /mol (calculated)

Log K
ow 3.788 pKa --



### The Agency does not routinely include in its risk assessments an evaluation of active ingredient (a.i.) mixtures—either mixtures of multiple activ e ingredients in product formulations or an applicator tank mix. However, if effects data are available fo r a formulated product containing more than one active ingredient, and demonstrate potentially enhanced toxi city to a non-target organism from exposure to the multiple active ingr edients, these data may be used qualitatively or quantitatively for risk assessment purposes.

B. Mechanism of Action

Fluroxypyr-MHE is a pyridine-based herbicide with selective toxicity to broadleaf weeds. When applied as fluroxypyr-MHE, the molecule rapi dly converts to the corresponding acid, fluroxypyr acid, in the environment or follo wing plant uptake. Fluroxypyr acid is an auxin analogue that

### 8

elicits auxin-like responses in the plant. Cellular effects include alterations in cell wall elasticity and gene expression. Additionally, non-productive tissue growth is often induced, resulting in epinasty and phloem disruption, preventing the movement of photosynthates and causing death in days to weeks. 13



### C. Overview of Pesticide Usage

Fluroxypyr-MHE is used to control weeds on agri cultural sites including barley, corn, millet, oats, onion, pastures, rice, sorghum, sod farms an d wheat as well as non- agricultural use sites such as golf courses, rangela nd, right-of-ways, and residential areas. The majority of products are formulated as emulsifiable concentrates, solu ble concentrate, or water-dispersible concentrate that are applied as a liquid spray with aerial or ground broadcast equipment. Three products may be applied as a stump or basal bark treatme nt for control of woody weeds (Reg. No. 62719-477, 62719-511, and 62719-637). Two products are lawn care products that are formulated as solid granules and are applied with a spreader (R eg. No. 961-406 and 288-426). A complete list of all current fluroxypyr-MHE uses and how EFED cu rrently understands the uses, including the

uncertainties for which reasonable conservative assumptions will be made in the absence of

additional label clarific ations, are listed in Table III.2

.

Based on pesticide usage data provided in the screening level usage an alysis conducted by the Biological and Economic Analysis Division (BE AD), the annual total agricultural usage of fluroxypyr-MHE averaged just over a half million pounds. For these same years, the largest markets in terms of total pounds active ingredie nt applied are wheat (400,000 lbs.), barley (60,000 lbs.) and pasture (50,000 lbs.). The ma ximum percent cropped area treated for fluroxypyr-MHE are observed for ba rley (35% maximum percent crop treated) and wheat (25% maximum percent crop treated). 14



### No usage data are available for non-agricultural use site s including golf courses, rights-of-way or

residential use sites.

13 Thill, D. 2002. Growth regulator herbicides. In He rbicide Action. Purdue University, West Lafayette, IN.

14 USDA-NASS 2004-2012; private pesticide market research 2004-2012; and California Department of Pesticide Regulation 2004-2011.9Table III.2. Fluroxypyr-MHE Label Summary

Crop/SiteTiming;ApplicationTypeMethod/EquipmentMaximumSingleApplicationRate byFormulationMaximumApplication RateMaximumApplicationNumber PHI (days) d MRI (days) d Geographic RestrictionsComments(a.i.lb/A)a(a.e.lb/A)bPerYearba.e.lb/APerCCb,clb a.e/APerYearPerCCcAgriculturalfallow/ idle land /conservationreserveFoliar, fallow,weed,postemergence, when needed,establishedplantingsBroadcast,spot treatment,direct spray/GroundAerial0.7624 0.5295 0.5295 nans[1]na ns naNot allowedin ArizonaReg. Nos. 228-599, 62719-480,62719-586,62719-637 Lowerapplication of 0.7224 permitted inArizona. Only one application isallowed (Reg. No. 62719-511)Agriculturaluncultivated areasWeedpostemergenceBroadcast,spot treatment/GroundAerial0.1875 0.1302 nsnans[26]na nans[3]NRReg. No. 66330-3870.3505 0.2434 0.2434ns[1]na Reg. No. 62719-577Agricultural/farmstructures/buildings and equipment(around)Weedpostemergence, foliarBroadcast,spot treatment,basiltreatment,stumptreatmentdirect spray/GroundAerial0.7224 0.5017 0.5017 nans[1]na na na NR Reg. No. 62719-447BarleyPostemergence,foliarBroadcast,chemigation,spot treatmentspray/GroundAerial0.2307 0.1602ns[4.2]ns[4.2]ns[26]ns[26] 7 (forage)nsNot allowedin specificCounties inNew York71368-88 does not restrict thenumber of applications that may beapplied per crop cycle or per year.0.5633 0.3912 ns 0.3912 nsns[1]nsNot allowedin CaliforniaBarley may be grown as part of acrop rotation with crops such astriticale. In absence of a per year10

Crop/SiteTiming;ApplicationTypeMethod/EquipmentMaximumSingleApplicationRate byFormulationMaximumApplication RateMaximumApplicationNumber PHI (days) d MRI (days) d Geographic RestrictionsComments(a.i.lb/A)a(a.e.lb/A)bPerYearba.e.lb/APerCCb,clb a.e/APerYearPerCCcapplication rate restriction croprotations will be considered.na 0.2255 0.3834 nans[2]naNot allowedin specificCounties inNew YorkReg. 1381-246Maximum application in restrictedcounties is allowed up 0.1808 lb/A.Chemigation applicationspermitted at 0.1808 lb a.i./Ana 0.1808 ns 0.1808 nsns[1]NRCommercial/industrial lawns, golfcourse turf,recreational arealawns, residentiallawnsFoliar, WhenneededBroadcast,spot treatment/Ground0.4311 0.2994ns[0.5987]na 2 nans[0]21Some labelsdo notpermit usein NewYorkReg. No. 228-419The second highest application rate(0.4073 lb a.i./A) does not specifya minimum retreatment interval(Reg. No., 228-418). This labelalso permits a max application rateper cc (1.12 a.i./A) that cannot beobtained based on the maximumsingle application rate (0.4073 lba.i./A) and the number ofapplication permitted per year (2).Conifer and treeplantationsWeed postemergenceBroadcast,Directed SpraySpotTreatment/GroundAerial0.7198 0.4999ns[26]nsns[26]ns na ns Reg. No. 62719-586Corn0.2003 0.1391 ns 0.2613 ns 2 ns NR11

Crop/SiteTiming;ApplicationTypeMethod/EquipmentMaximumSingleApplicationRate byFormulationMaximumApplication RateMaximumApplicationNumber PHI (days) d MRI (days) d Geographic RestrictionsComments(a.i.lb/A)a(a.e.lb/A)bPerYearba.e.lb/APerCCb,clb a.e/APerYearPerCCcPreplant, PostemergencefoliarBroadcast,Chemigation,SpotTreatment/GroundAerial- 0.1808 ns 0.1808 nsns[1] 31 (sweet corn)SCOnly allowed in Colorado, Kansas,Minnesota, Nebraska, NorthDakota, Oklahoma, South Dakota,Texas and WyomingGrassforage/fodder/hayWeedpostemergenceBroadcast/GroundAerial0.199 0.1382 0.1382 nsns[1]nsnansApplicationspermitted inFlorida only.FL070003 does not specify amaximum annual application rateor number of applications.0.2003 0.1391 ns 0.2434 nsns[2]14 NR Reg. No. 62719-577Grasses Grownfor SeedEstablishedPlantings,Seedling stageBroadcast,Chemigation,SpotTreatment/GroundAerial- 0.1808 ns 0.1808 nsns[1]na0.1881 0.1306 ns 0.2613 nsns[2]Household/domestic dwellingsoutdoor premisesweedpostemergenceBroadcast,spot treatment/GroundAerial0.7198 0.4999 ns ns ns ns na ns Reg. No. 62719-586Industrial /construction areas(outdoor)weedpostemergenceBroadcast,spot treatment/GroundAerial0.2886 0.2004ns[0.2004]ns 1 ns na ns NRSpot treatment is permitted at amaximum single application rate0.2891 lb a.i./A with a yearlyapplication rate restriction of0.2886 a.i./A.12

Crop/SiteTiming;ApplicationTypeMethod/EquipmentMaximumSingleApplicationRate byFormulationMaximumApplication RateMaximumApplicationNumber PHI (days) d MRI (days) d Geographic RestrictionsComments(a.i.lb/A)a(a.e.lb/A)bPerYearba.e.lb/APerCCb,clb a.e/APerYearPerCCcMilletspringBroadcast,spot treatment/GroundAerial0.2003 0.1391 ns [see comments]0.2434 ns [see comments]2 na 14 NR2 day pre-slaughter intervalMillet may be grown as part of acrop rotation with crop such ascorn, and wheat. In absence of aper year application rate restrictioncrop rotations will be considered.Nonagriculturalrights-ofway/fencerows/hedgerows,WeedpostemergenceBroadcast/Aerial0.7624 0.5295 0.5295 nans[1]nanansNot allowedin ArizonaWhen neededBroadcast/Ground4.3 3.0ns[78]nsns[26]ns ns Reg. No. 228-419Nonagriculturaluncultivatedareas/soilsWeedpostemergenceBroadcast/GroundAerial0.7624 0.5295 0.5295 nans[1]na na nsNot allowedin ArizonaOatPostemergencefoliarBroadcast/GroundAerial0.5633 0.3912ns[SC]0.3912ns[SC]ns 7 (forage)ns NRReg. No. 62719-536Oats may be grown as part of acrop rotation with crop such ascorn, wheat, and triticale. Inabsence of a per year applicationrate restriction crop rotations willbe considered.0.2307 0.1602 nsns[4.2]nsns[26]OnionPostemergencefoliarBroadcast/GroundAerial0.1753 0.1217ns[0.7302]0.2434ns[6]2 7 10Allowed inIdaho,Texas, Utah,WisconsinReg. No. 66330-387.Lower application (0.0938 lba.i./A) permitted in other locations.13

Crop/SiteTiming;ApplicationTypeMethod/EquipmentMaximumSingleApplicationRate byFormulationMaximumApplication RateMaximumApplicationNumber PHI (days) d MRI (days) d Geographic RestrictionsComments(a.i.lb/A)a(a.e.lb/A)bPerYearba.e.lb/APerCCb,clb a.e/APerYearPerCCcMultiple onion crops may begrown in some locations. For thisassessment three seasons/cropcycle or six yearly applicationsseasons will be assumed.Ornamentallawns and turfPostemergencefoliarBroadcast/GroundAerial0.7224 0.5017ns[1.00]na 2 na ns NRReg. No. 62719-511. Lowerapplication rate of 0.7198 lb a.i./Apermitted by aircraft.Granularbroadcast/Ground0.5394 0.3748 1.0789 0.7496 2 2Ornamental sodfarm (turf)PostemergencefoliarBroadcast/GroundAerial0.7198 0.4999 0.4999 na 1 na nansSCAllowed inFloridaLower application (2 x 0.3374 lba.i./A) permitted in other locationsMRI: 21-30 (for lower applicationsrates)Pastures,RangelandPostemergencefoliarBroadcast,basaltreatment,directed spray/GroundAerial0.7624 0.5295 0.5295 nans[1]na na nsAllowed inFloridaMay berestricted insome otherlocationsLower application (0.7224 lba.i./A) permitted in other locationsPaved areas(privateroads/sidewalks)FoliarBroadcast,Spottreatment/Ground0.40730.2829[0.3889]ns[0.7777]0.7777 2ns[2]naReg. No. 62719-586Spot treatment application rate(0.0095 lb a.i./gal) Appling maxrate twice doesn’t equal max per cclabel rate.14

Crop/SiteTiming;ApplicationTypeMethod/EquipmentMaximumSingleApplicationRate byFormulationMaximumApplication RateMaximumApplicationNumber PHI (days) d MRI (days) d Geographic RestrictionsComments(a.i.lb/A)a(a.e.lb/A)bPerYearba.e.lb/APerCCb,clb a.e/APerYearPerCCcPome fruitsWeedpostemergenceBroadcast/Ground0.701 0.487 0.487 na 1 na 14 na NRRecreationalareasWeedpostemergenceBroadcast/GroundAerial0.7224 0.5017ns[13]nans[26]na na ns NR Reg. No. 62719-511RicePostemergencefoliarBroadcast/Aerial0.3807 0.2644ns[0.4368]0.4368 2 ns 60 10Allowed inArkansas,Florida,Louisiana,Mississippi,Missouri,Tennessee,TexasReg. No. 62719-648Earthen RoofsWeedpostemergenceBroadcast/Ground0.7149 0.4965ns[12.9]nsns[26]ns na nsAllowed inAlabamaReg. No. 228-599RyePostemergenceBroadcast,spot treatment/GroundAerial0.2605 0.1809ns[SC]ns[0.1809]ns[SC]1 60 ns NRRye may be grown as part of acrop rotation with crops such ascorn and wheat. In absence of a peryear application rate restrictioncrop rotations will be considered.SorghumPostemergenceBroadcast/GroundAerial0.2003 0.1391 ns 0.2434 ns 2 45 nsPreemergence application allowedat a slightly lower rate (acid)SudangrassWeedpostemergenceBroadcast,spot treatment/GroundAerial- 0.1808 ns 0.1808 nsns [1] 45 ns NR15

Crop/SiteTiming;ApplicationTypeMethod/EquipmentMaximumSingleApplicationRate byFormulationMaximumApplication RateMaximumApplicationNumber PHI (days) d MRI (days) d Geographic RestrictionsComments(a.i.lb/A)a(a.e.lb/A)bPerYearba.e.lb/APerCCb,clb a.e/APerYearPerCCcTriticalePostemergencefoliarBroadcast/GroundAerial0.3505 0.2434ns[SC]0.2434ns[SC]ns[1]45 ns NRChemigation, spot treatmentpermitted at lower applicationrates.Triticale may be grown as part of acrop rotation with crop such asbarley and oats. In absence of a peryear application rate restrictioncrop rotations will be considered.WheatFoliarBroadcast/GroundAerial0.5633 0.3912ns[24.2]nsns[26]ns 7 (forage)ns NRReg. No. 62719-536Chemigation applicationspermitted at 0.1808 lb a.i./AWheat may be grown as part of acrop rotation with other crops suchas corn, rye and sorghum. Inabsence of a per year applicationrate restriction crop rotations willbe considered.a.Fluroxypyr-MHE is reported in terms of active ingredient (a.i.)b.Reported in terms of fluroxypyr acid or acid equivalents (a.e.)c.Reported as per crop cycle or per seasond.PHI – Preharvest Interval; REI – Reentry Interval; MRI – Minimum Retreatment IntervalNo Restrictions (NR); See Comments (SC)[ ] are used to define assumptions that will be made in absencesof label clarification. When information was not specified onthe label the maximum number ofapplications was assumed to be 26 that corresponds to one application every two weeks.

### 16

D. Environmental Fate and Transport

Environmental fate parameters of flur oxypyr-MHE and fluroxypyr acid are presented in Table

III

. 3 and Table III.4 . Total toxic residues (f luroxypyr-MHE and fluroxypyr acid) residues are

also discussed in Table III.4 . Half-life values referenced are re presentative half-life values and

are consistent with th e NAFTA kinetics guidance 15 

### unless otherwise specified. A discussion of each environmental fate parameter is provided in APPENDIX C for fluroxypyr-MHE and fluroxypyr acid. Kinetic analys es are also provided in APPENDIX C . The proposed fluroxypyrMHE environmental transformati on scheme is presented in Figure III.1

. Major transformation products include: fluroxypyr acid, fluroxypyr-D CP, fluroxypyr-MP, and carbon dioxide. The

maximum observed concentrations of each of the environmental transformation products are provided in APPENDIX C as well as a full list of chemical code names and synonyms.

In summary, laboratory data s uggest that fluroxypyr-MHE, a met hylheptyl ester, undergoes rapid deesterification to fluroxypyr acid following application. Aerobic so il half-life values are less than one day (MRID 42137317) for fluroxypyr-MHE while the aerobic aquatic half-life is approximately one day (MRID 44080345) under basi c conditions (pH 8.2). Hydrolysis of fluroxypyr-MHE is pH dependent. U nder basic conditions (pH 9) hydrol ysis is rapid with a halflife of approximately 3 days while under acid conditions fluroxypyr-MHE is stable (half-life 454 days). Increased hydrolysis of the ester in aquati c soil systems as compared to sterile aqueous solutions is thought to be due to microbial mediation ( i.e. , enzymatic catalysis). This hypothesis is supported in th e open literature. 16 

### Mobility data for fluroxypyr-MHE are not considered

reliable due to short incuba tion period (MRID 42137319); however, it is not expected to be mobile. Fluroxypyr-MHE is not expected to be volatile (MRID 47600903) and is not expected to bioconcentrate. BCF values for fluroxypyr-MHE and total 14 

### C activity were 42 (uncorrected; 26 corrected value) and 167 for whole fis h, respectively [MRIDs 44080348 and 44605403 (response to review of MRID 44080348)].

While fluroxypyr-MHE is subject to both abiotic (aqueous photolys is and alkaline hydrolysis) and biotic (metabolism) degradation, the corr esponding acid, fluroxypyr aci d, is expected to be more persistent and is mobile, as are some of the other structurally similar transformation products (fluroxypyr-DCP and fluroxypyr-MP). In th e environment, fluroxypyr acid is expected to be present as the anion (estimated pKa 2.94) . Aerobic soil metabolism half-life values for fluroxypyr acid range from 8.2 to 30 days while th e aerobic aquatic half-l ife is approximately 3 days. K oc 

### values range from 51 to 81 mL/g oc 

### for fluroxypyr acid (MRID 42137319).

Field data (MRIDs 44896702, 45204201, 45204202, and 44080347) indicate that combined residues (summation of fluroxypyr-M HE and fluroxypyr acid) half-life values range from 5 to 55 days. The terrestrial field dissi pation studies also indicate th at fluroxypyr-MHE residues (i.e. fluroxypyr acid), may leach th rough the soil profile.

15 Guidance for Evaluating and Calculating Degradation Kinetics in Environmental Media Health Canada, U.S. Environmental Protection Ag ency, December 21, 2012.

16 Lehmann, R. G., Miller, J. R., Weed Research, 1989

, 29, 385-389.17Table III.3. Chemical Properties and Environmental Fate Parameters of Fluroxypyr-MHEStudySystem Name/CharacteristicsKinetic Model FittedaValueand Unit(Fitting Equation)Representative Halflife Value--Value Used to DeriveModel Input Values(days)b--Guideline/Source/ClassificationCommentsDT50 (days)DT90 (days)HydrolysispH 5Not observedStable835.2010MRID40244539AcceptablepH 7454 1510t1/2=454pH 93.1 10.3t1/2=3.1AqueousPhotolysisnatural waterNot Determinable Assumed Stable835.2240MRID44080342AcceptableDue to the rapid degradation in the dark control(faster than irradiated samples)phototransformation of fluroxypyr-MHE in watercould not be appropriately assessed as a route ofdissipation.0.01 M sodium phosphatepH 5128 424 StableDefinitive determination of the transformationproducts was not provided; however, noindividual product made up more than 10% of theapplied radioactivity.SoilPhotolysisClay loam Not Determinable Assumed Stable835.2410MRID44080343AcceptableDue to the rapid degradation in the dark control(equal to the irradiated samples) phototransformation of fluroxypyr-MHE in soil couldnot be appropriately assessed as a route ofdissipation.Aerobic SoilMetabolism“M172” Illinois Catlin Siltloam (2.2% OC, pH 5.9, 26± 1 oC)0.3 (SFO) 1.0 (SFO) t1/2=0.3835.4100MRID42137317Acceptable42730001(responsefromregistrant)Deesterification of most of the appliedfluroxypyr-MHE occurred within one day. Aseparate storage stability study (MRID44080355) was conducted on frozen (temperaturenot specified) Catlin Silty Loam (soilcharacterization was not provided) for up to 422days for fluroxypyr-MHE. Samples were storedup to a year at -20 oC.“M174” California HanfordSandy loam (0.2% OC, pH7.5, 26 ± 1 oC)0.3 (SFO) 0.9 (SFO) t1/2=0.3“M177” North DakotaBarnes Loam (3.1% OC, pH6.8, 26 ± 1 oC0.1 (IORE) 1.5 (IORE) TIORE=0.4“M192” Mississippi MhoonSilty clay (1.3% OC, pH7.0, 26 ± 1 oC)0.3 (IORE) 3.7 (IORE) TIORE=1.1AnaerobicSoilMetabolismNo data are available 835.420018StudySystem Name/CharacteristicsKinetic Model FittedaValueand Unit(Fitting Equation)Representative Halflife Value--Value Used to DeriveModel Input Values(days)b--Guideline/Source/ClassificationCommentsDT50 (days)DT90 (days)AerobicAquaticMetabolismNorth Dakota silt loamsediment with natural water(25 oC, pH 8.2)1.0 (SFO) 3.4 (SFO) t1/2=1.0835.4300MRID44080345AcceptableUnextracted residues were 56.7% and 41.4% ofthe applied radioactivity at 4 months and 12months posttreatment, respectively.Data are only available for one test system andthe pH of the test system is 8.2. Fluroxypyr-MHEwas shown to rapidly hydrolyze under basicconditions (pH 9). Assumed LOD was 0.1% ofthe applied radioactivity for kinetic analysis.AnaerobicAquaticMetabolismNorth Dakota silt loamsediment flooded withnatural water(25 oC, pH 8.2)1.3 (SFO) 4.2 (SFO)t1/2=1.3834.4400MRID44080344reclassified tosupplementalSample frequency was inadequate to accuratelyassess the transformation of fluroxypyr-MHEunder anaerobic aquatic conditions. FluroxypyrMHE was only present at 2% of appliedradioactivity at the second sample interval (1week). Data are only available for one test systemand the pH of the test system is 8.2. FluroxypyrMHE was shown to rapidly hydrolyze underbasic conditions (pH 9). Unextracted residueswere 28.2% of the applied radioactivity at 12months posttreatment. Despite thesedeficiencies, this studysuggests that fluroxypyrMHE rapidly degrades under anaerobic aquaticconditions tested.TerrestrialFieldDissipationMissouri, Putnam silty clayloam, pH 7.5Not determinable t1/2=24.8835.6100MRID44080347SupplementalData for fluroxypyr MHE were not provided intabular form in the study report. In addition, theapplication rates used in the study were notverified. Storage stability data were not providedfor the soils used in this study. The study sampleswere stored frozen (temperature not reported) forup to 693 days. A separate storage stability study(MRID 44080355) was conducted on frozen(temperature not specified) Catlin Silty Loam(soil characterization was not provided) for up to422 days for fluroxypyr-MHE. This studydemonstrated that fluroxypyr-MHE was stable insoil frozen up to 92 days. After 92 days 71%remained and after 422 days 61% remained.Concurrent analytical methods recoveries of theNorth Dakota, gardenasandy clay loam, pH 6.2Not determinablet1/2=36.3Washington, quincy loamysand, pH 6.8Not determinable t1/2=13.219StudySystem Name/CharacteristicsKinetic Model FittedaValueand Unit(Fitting Equation)Representative Halflife Value--Value Used to DeriveModel Input Values(days)b--Guideline/Source/ClassificationCommentsDT50 (days)DT90 (days)fluroxypyr-MHE from soil samples fortifiedseparately were highly variable (46-142%).Reported half-life valuesare registrant-calculatedhalf-life values that are based on the sum ofresidues of fluroxypyr-MHE plus fluroxypyracid. Because data are not available in the studyreport for fluroxypyr-MHE these half-life valuescould not be verified.Aquatic FieldDissipationTexas, cropped plot;pH 6.4, 0.7% OMValues not calculatedMRID48581303Scientificallyvalid;however,study is underreviewKinetic evaluations were not conducted forfluroxypyr-MHE by the study author due to therapid hydrolysis of fluroxypyr-MHE tofluroxypyr acid. If possible kinetic analysis willbe conducted for fluroxypyr-MHE upon finalreview.Texas, non-cropped plot;pH 6.1, 0.9% OMCalifornia, cropped plot; pH7.9, 1.2% OMCalifornia, non-croppedplot; pH 7.8, 1.6% OMa.DT50 and DT90 values were calculated using single first-order (SFO), double first- order in parallel (DFOP), or indeterminate-order equation (IORE). For DFOP, theoverall DT50 and DT90 are reported when available. The equations can be found in the document,Standard Operating Procedure for Using the NAFTA Guidance toCalculate Representative Half-life Values and Characterize Pesticide Degradation,U.S. Environmental Protection Agency, November 30, 2012.b.The value used to estimate a model input value is the calculated SFO DT50, TIORE, or the 2ndDT50from the DFOP equation. The model chosen is consistent with thatrecommended using the,Guidance for Evaluating and Calculating Degradation Kinetics in Environmental Media, Health Canada, U.S. Environmental ProtectionAgency, December 21, 2012. The same model used to estimate the value used to derive a model input, is used to describe the DT50and DT90 results.c.Reported value is an extrapolated value determined by the study author and is based on the assumption that continuation of theapparent degradation pattern occursbeyond the scope of the observed data. Due to the stability of fluroxypyr-MHE to aquatic photolysis and the minimal impact of aquatic photolysis of fluroxypyr-MHE inthe environment updated kinetic analysis were not completed.20Table III.4. Chemical Properties and Environmental Fate Parameters of FluroxypyrStudySystem Name/CharacteristicsKinetic Model FittedaValueand Unit(Fitting Equation)Representative Halflife Value--Value Used toDerive Model InputValues (days)b--Guideline/Source/ClassificationCommentsDT50 (days)DT90 (days)HydrolysispH 5Not observed Stable835.2010MRID40244539AcceptableTotal toxic residues will considered stable tohydrolysis.pH 7pH 9AqueousPhotolysisnatural water Not determinableStable835.2240MRID44080342Acceptable0.01 M sodium phosphatepH 55581853Definitive determination of the transformationproducts was not provided; however, no individualproducts made up more than 10% of the appliedradioactivity.Total toxic residues will be considered stable toaquatic photolysis.Soil Photolysis Clay loamNot determinableStable835.2410MRID44080343AcceptableDue to the rapid degradation in the dark control(equal to the irradiated samples)phototransformation of fluroxypyr-MHE in soilcould not be appropriately assessed as a route ofdissipation under the conditions used in this study.Aerobic SoilMetabolism“M172” Illinois Catlin Siltloam (2.2% OC, pH 5.9)13.5 (SFO) 44.9 (SFO) t1/2=13.5835.4100MRID42137317AcceptableWithin one day, most of the fluroxypyr-MHE hadhydrolyzed to fluroxypyr. Kinetic analysis weredone using data from day 2 to 366.Total residues (combined MHE and acid) half-lifevalues ranged from 8.4 to 30.1 days.“M174” CaliforniaHanford Sandy loam(0.2% OC, pH 7.5)30 (SFO) 99.7 (SFO) t1/2=30“M177” North DakotaBarnes Loam (3.1% OC,pH 6.8)15.7 (SFO) 52.3 (SFO) t1/2=15.7“M192” MississippiMhoon Silty clay (1.3%OC, pH 7.0)8.2 (SFO) 27.3 (SFO) t1/2=8.2Anaerobic SoilMetabolismNo data are available 835.420021AerobicAquaticMetabolismNorth Dakota silt loamsediment with naturalwater(25 oC, pH 8.2)3.2 (SFO) 10.5 (SFO) t1/2=3.2835.4300MRID44080345SupplementalHalf-life value calculated is based on data fromweek 2 - 12 months. Data are only available forone test system and the pHof the test system is 8.2and fluroxypyr was shown to be stabile tohydrolysis under basic conditions (pH 9).AnaerobicAquaticMetabolismNorth Dakota silt loamsediment flooded withnatural water(25 oC, pH 8.2)2.7 9.1 t1/2=2.7834.4400MRID44080344reclassified tosupplementalHalf-life value calculated is based on data fromweek 2 - 12 months. Unextracted residues were12.1% and 27.8% of the applied radio activity at 4weeks and 12 months posttreatment, respectively.Data are only available for one test system and thepH of the test system is 8.2 and fluroxypyr wasshown to be stabile to hydrolysis under basicconditions (pH 9).A total residues (combined MHE and acid) halflife value of 4.9 days was estimated.TerrestrialFieldDissipationSeeTable III.4Reported half-life values are based on the sum ofresidues of fluroxypyr-MHE plus fluroxypyr acid.Aquatic FieldDissipationTexas, cropped plot;pH 6.4, 0.7% OMt1/2=14.7 (study author reported value)MRID48581303Scientificallyvalid;however,study is underreviewReported half-life values are based on meanrecoveries from three replicate plot samples asreported by the study author. These values will beupdated if needed upon final review. Based onthese results the transformation is slower at lowerpH.Texas, non-cropped plot;pH 6.1, 0.9% OMt1/2=16.7 (study author reported value)California, cropped plot;pH 7.9, 1.2% OMt1/2=4.0 (study author reported value)California, non-croppedplot; pH 7.8, 1.6% OMt1/2=4.6 (study author reported value)a.DT50 and DT90 values were calculated using single first-order (SFO), double first- order in parallel (DFOP), or indeterminate-order equation (IORE). For DFOP, theoverall DT50 and DT90 are reported when available. The equations can be found in the document,Standard Operating Procedure for Using the NAFTA Guidance toCalculate Representative Half-life Values and Characterize Pesticide Degradation,U.S. Environmental Protection Agency, November 30, 2012.b.The value used to estimate a model input value is the calculated SFO DT50, TIORE, or the 2ndDT50from the DFOP equation. The model chosen is consistent with thatrecommended using the,Guidance for Evaluating and Calculating Degradation Kinetics in Environmental Media, Health Canada, U.S. Environmental ProtectionAgency, December 21, 2012. The same model used to estimate the value used to derive a model input, is used to describe the DT50and DT90 results.c.Registrant-calculated half-life as the sum of the fluroxypyr-MHE plus fluroxypyr (acid).

### 22

N O Cl NH 2 Cl

F O

O 4 N O Cl NH 2 Cl

F OH

O

N OH Cl NH 2 Cl

F

N OH NH 2 Cl

F N OH Cl NH 2

F N OCH 3 Cl NH 2 Cl

F Fluroxypyr-MHE Fluroxypyr

Fluroxypyr-MP Fluroxypyr-DCP



### Figure III.1. Fluroxypyr-MHE Environmental Transformation Scheme

Environmental chemistry methods along with an independent laboratory validation study report the limit of quantifica tion (LOQ) of fluroxypyr acid, fluroxy pyr-DCP and fluroxypyr-MP in soil [0.01 ppm (0.01 mg/kg; 10 μg/kg; 0.02 lb/A 17 

### ) (MRIDs 44080346 (ECM; GRM 93.03), 44896703 (ECM; GRM 98.04 superseding GRM 93.03) and 45084601 (ILV; GRM 98.04))]. A limit of detection (LOD) was not established in these studies; therefore, the LOD is assumed to be equal to the LOQ.

A recently submitted aquatic field dissipa tion study (MRID 48581303; GRM 08.06) reported a LOQ of 10 μg/kg and an LOD of 3 μg/kg (0.007 lb/A) for fluroxypyr-MHE, fluroxypyr acid, fluroxypyr-DCP and fluroxypyr-MP in soil. No indepe ndent laboratory valida tion is available for this method (GRM 08.06). The analytical me thod available for fl uroxypyr-MHE, fluroxypyr acid, fluroxypyr-DCP and fluroxypyr-MP in water re ports a LOQ of 0.05 μg/L with an LOD of 0.015 μg/L (MRID 48581303); however, an independent laboratory validation has not been submitted for this method. An alternative method (MRID 45824101; GRM 00.21) is available that reports a LOQ of 5 μg/L. This method ha s also not been independently verified.

A non-guideline study was submitted to assess the fate of fluroxypyr-MHE and fluroxypyr acid in compost (MRID 45833601). This study suggests th at fluroxypyr acid resi dues should not pose

17 LOQ = 0.01 mg/kg 0.02 mg/kg (s) = [x] kg/ha x 10 6 mg/kg / [0.15 m (depth) x 10 4 m 2 /ha x 1.5 x 10 3 kg(s)/m 3 (density)] 0.02 mg/kg(s) = [x] kg/ha x 10 6 mg/kg / 2.25 x 10 6 kg (s)/ha

= 2.25 x 10 -2 kg/ha = LOQ = 0.02 lb/A

### 23

a compost concern (fluroxypyr acid half-life is approximately 5 days); however, some major study deficiencies were identifi ed. Without additional information to support the methods used and how the study was conducted, another compos t study is warranted (additional discussion provided in APPENDIX C ).



## IV. RECEPTORS

This section describes the aquati c and terrestrial taxonomic groups th at represent receptors in the ecological risk assessment for the use of fl uroxypyr-MHE, and the toxicological endpoints

selected to characterize acute and chronic effect s to these taxonomic gr oups. In general, the endpoints selected are the most sensitive ( i.e. , lowest) value measured among all test species in the taxa obtained from acceptable studies. In cases when an acceptable study is not available or indicates less sensitivity than does a supplem ental study, results from a supplemental study may be used. A complete listing of all toxicological results from submitted ecotoxicological studies and relevant open literature studies is provided in APPENDIX D

.

Because fluroxypyr-MHE rapidly transforms in to fluroxypyr acid, toxic ity endpoints for both fluroxypyr-MHE and fluroxypyr acid are provided and will be considered in future risk assessments. When available, ecotoxicity data for the environmental transformation products of fluroxypyr acid, fluroxypyr-DCP and fluroxypyr-MP, are also provided.

1. Effects to Aquatic Organisms

Table IV.1 and Table IV .2 

### summarizes the toxicity endpoints for the most sensitive species, by taxa, for fluroxypyr-MHE and fluroxypyr acid, re spectively. The data for fluroxypyr-MHE are presented as both active i ngredient (a.i.) and the acid equivalent (a.e.).

Based on acute toxicity, the aquatic animal speci es most sensitive to fluroxypyr-MHE was the Eastern oyster ( Crassostrea virginica ). In a 96-hr shell deposition study (MRID 44080310), a significant decrease in shell de position was observed at concen trations of 50 μg a.i./L and greater. The EC 50 

### was 68 μg a.i./L, which classifies fluroxypyr-MHE as highly toxic to the oyster on an acute exposure basis.

In all other taxa of aquatic animals, the acute toxicity classification co uld not be determined because of the limited solubility of fluroxypyr-M HE and lack of mortality observed at the solubility limit of the compound. Wh en tested at a concentration near the solubility limit, no mortality or sublethal effects were observed in the bluegill sunfish ( Lepomis macrochirus , MRID 44080307), rainbow trout ( Oncorhynchus mykiss , MRIDs 40244522 and 42137307 ), the golden orfe ( Leucescus idus , MRID 40244523), the Atlantic silverside ( Menidia menidia , MRID 42137309), the sheepshead minnow ( Cyprinodon variegatus , MRID 44080308), or the grass shrimp ( Palaemonetes pugio , MRID 44080313). Tests with the water flea ( Daphnia magna ) also found no mortality when test ed at the solubility limit (MRIDs 40244520 and 42137308). The sublethal effect of occasional immobility was observed in one of these two studies (MRID 42137308); however, this effect appears to be fr om physical impairment of movement by large clumps of undissolved test mate rial, and therefore were not indi cative of toxicity of fluroxypyrMHE. While the toxicity endpoint could not be de termined, these tests nevertheless indicate that

### 24

fluroxypyr-MHE is not acutely toxic to the test organism at concen trations up to the solubility

limit.

Therefore, prior to transformation to fluroxypyr acid, residues of fluroxypyr-MHE that may be present in natural water are expected to have minimal toxicity on an acute exposure basis to aquatic animals except for mollusks, to which fluroxypyr-MHE is highly toxic. Information on the chronic toxicity of fluroxypyr-MHE is limite d, but based on the results of a supplemental life-cycle study with Daphnia magna , chronic toxicity appears to be greater than acute toxicity. Adverse effects on the reproduction of Daphnia magna were observed at concentrations as low as 0.109 mg a.i./L (MRID 44080314).

Testing with aquatic plants and alg ae found that the freshwater diatom (Navicula pelliculosa ) is the most sensitive species, with an EC 50 

### of 56 μg/L and toxic e ffects observed at test concentrations as low as 15 μg/L (the lo west concentration tested) (MRIDs 44080339 and 44527201). For assessing risk to vasc ular aquatic plants, reliance on results from testing with duckweed would not be appropria te since duckweed is a monoc otyledonous plant, and the toxicity of auxin growth regul ators like fluroxypyr-MHE is sele ctive to dicotyledonous plants (Mohr et al., 2013, Maltby et al., 2010). Mohr et al (2013) report results of te sts of the effects of fluroxypyr-MHE on water milfoil ( Myriophyllum spicatum ), an aquatic dicotyledonous macrophyte that has been shown to be more sensitive to fluroxypyr-MHE than is duckweed. The paper reports results for a 14-day laboratory study without sediment , which is similar to the draft OECD guideline ENV/JM/TG(2014)5, as well as a 16-day and a 30-d microcosm studies. A review of this paper will be conducted to determ ine which of these results (if any) are suitable for quantitative or qualitative use in risk assessmen t. A preliminary review of this paper indicates that all three of the studies are scientifically s ound and are suitable for at least qualitative use in

risk assessment.

Table IV.1. Most Sensitive Endpoints from A quatic Toxicity Studies for Fluroxypyr-MHE

Taxonomic

Group Study Type Surrogate Species Toxicity Value Acute Toxicity

Classification Source (Study Classification)

Freshwater fish 1 Acute Bluegill Sunfish ( Lepomis

macrochirus ) LC 50 > 0.63 mg a.i./L 2 (> 0.44 mg a.e./L) Not

determined 44080307 (Acceptable)

Chronic -- Not Available --

--

Freshwater

invertebrates Acute Water Flea ( Daphnia magna ) EC 50 > 0.6 mg a.i./L 2 (>0.4 mg a.e./L) Not

determined 40244520 (Acceptable)

Chronic Water Flea NOAEC = 60.5 μg a.i./L (42.0 μg a.e./L)

LOAEC = 109 μg a.i./L (75.7 μg a.e./L) Endpoint: Number of young per female -- 44080314 (Supplemental) 3

### 25

Taxonomic

Group Study Type Surrogate Species Toxicity Value Acute Toxicity

Classification Source (Study Classification)

Estuarine/marine

fish Acute Sheepshead

Minnow ( Cyprinodon variegatus ) LC 50 > 0.087 mg a.i./L (> 0.060 mg a.e./L) Not

determined 44080308 (Acceptable)

Chronic -- Not Available --

--

Estuarine/marine

crustaceans Acute Grass shrimp ( Palaemonetes pugio ) EC 50 > 0.13 mg a.i./L (> 0.090 mg a.e./L) Not

determined 44080313 (Acceptable)

Estuarine/marine

mollusks Acute

Shell Deposition Eastern oyster, ( Crassostrea virginica ) EC 50 = 0.068 mg a.i./L (0.047 mg a.e./L) Highly toxic 44080310 (Supplemental) 4

Aquatic plants and algae Vascular Duckweed ( Lemna gibba ) NOAEC = 0.44 mg a.i./L (0.31 mg a.e./L)

IC 50 = 1.4 mg a.i./L (0.97 mg a.e./L) -- 44744001 (Supplemental) 5

Water milfoil ( Myriophyllum spicatum ) 14-day IC 50 (laboratory study): 0.42 mg a.i./L (0.29 mg a.e./L)

16-day IC 50 (Microcosm study): 0.12 mg a.i./L (0.083 mg a.e./L)

30-day IC 50 (Microcosm study): 0.09 mg a.i./L (0.06 mg a.e./L) -- Mohr et al.,

2013 (in review)

Nonvascular Freshwater

Diatom (Navicula pelliculosa ) NOAEC < 15 μg a.i./L < 10 μg a.e./L

IC 50 = 56 μg a.i./L (39 μg a.e./L) -- 44080339

44527201 (Supplemental) 6

1 Freshwater fish may be surrogate s for aquatic-phase amphibians.

2 The LC 50 is greater than the solubility limit of fluroxypyr MHE.

3 This study is supplemental because insoluble te st material was present in the test solution.

4 This study is supplemental because it was conducted at nominal concentrations which far exceeded the solubility of fluroxypyr MHE, and the three highest test solutions were cloudy throughout the te st. The oysters apparently were exposed to suspended undissol ved test material as well as test material within solution, and this e xposure to undissolved test material may have contributed to the t oxicity observed in this study.

5 This study is supplemental because test conditions (temperature, light intensity, and pH) were slightly outside the ranges recommended by the test guideline.

6 This study is supplemental because the solvent control solutions were contaminat ed with the test solu tion and the failed to

establish an NOAEC.

### 26

Table IV.2 

### summarizes the toxicity endpoints used to a ssess the risk of fluroxypyr acid to aquatic organisms. The data indicate that fluroxypyr acid is much less toxic to aquatic animals than fluroxypyr-MHE. The most sensitive species to fl uroxypyr acid is the bluegill sunfish, for which the acute toxicity is classified as slightly toxic (LC 50 

### = 14.3 mg/L). Fluroxypyr acid is classified as slightly toxic to saltwater fish, practically non toxic to freshwater invertebrates, and slightly

toxic to saltwater mollusks. Chroni c toxicity data are only availa ble for a freshwater fish (the fathead minnow). The NOAEC for freshwater fish is 5.9 mg a.i./L based on reductions in length and wet weight.

For fluroxypyr acid, valid toxicity data are availa ble for one species of nonvascular plant, the freshwater algal Scenedesmus pannonicus . The acute 96-hr toxicity was greater than 100 mg a.i./L, indicating that the species is relativel y insensitive to fluroxypyr acid. However, little information on toxicity to nonvascular plants can be drawn from this one study because it is supplemental and used a non-preferred species. Base d on the results of this study conducted with fluroxypyr-MHE it is assumed that algae is relativ ely insensitive to flur oxypyr (either ester or acid) compared to freshwat er and saltwater diatoms.

Table IV.2. Most Sensitive Endpoints from A quatic Toxicity Studies for Fluroxypyr Acid

Taxonomic

Group Study Type Surrogate Species Toxicity Value (in terms of measured

active ingredient) Acute Toxicity

Classification Source (Study Classification)

Freshwater fish 1 Acute Bluegill Sunfish LC 50 = 14.3 mg a.i./L Slightly toxic 42137306 (Acceptable)

Chronic (Early Life Stage) Fathead minnow ( Pimephales promelas ) NOAEC = 3.0 mg a.i./L LOAEC = 5.9 mg a.i./L Endpoints: Length and wet weight -- 48559401 (Acceptable)

Saltwater fish Acute Atlantic Silverside LC 50 = 40 mg a.i./L Slightly toxic 44080309 (Acceptable)

Chronic -- Not available

-- --

Freshwater

invertebrates Acute Water Flea EC 50 > 100 mg a.i./L Practically

nontoxic 40244521

40244524 (Acceptable)

Chronic Water Flea Not available

--

Saltwater

invertebrates Acute

Shell Deposition Eastern oyster ( Crassostrea virginica ) LC 50 = 51 mg a.i./L Slightly toxic 44080311 (Acceptable)

Chronic -- Not available --

--

### 27

Taxonomic

Group Study Type Surrogate Species Toxicity Value (in terms of measured

active ingredient) Acute Toxicity

Classification Source (Study Classification)

Aquatic plants and algae 2 Vascular -- Not available -- --

Nonvascular Freshwater Algae ( Scenedesmus pannonicus ) NOAEC = 100 mg a.i./L

EC 50 > 100 mg a.i./L -- 40244526 (Supplemental) 3

1 Freshwater fish may be surrogate s for aquatic-phase amphibians.

2 Toxicity endpoints presented, i.e. , NOAEC or EC 50 , are the only ones available from the study.

3 The test species is not an acceptable in US guidelines, and cell counts were not determined.



### 2. Effects to Terrestrial Organisms

The LOD of fluroxypyr-MHE and fluroxypyr acid resi dues in soil (3 μg/kg) are not sufficient for identifying the presence or absence of fluroxypy r-MHE at levels equal to the toxicological endpoints for terrestrial plants. Therefore, it is possible that effects could occur following the application of fluroxypyr-MHE with out being able to detect the presence of the chemical. The LOD of fluroxypyr-MHE residues in water (0.05 μg/L) is sufficient based on data currently

available. If more sensitive a quatic species are identified a new method may be needed in order

to insure residues of levels of toxi cological concern can be detected. Table IV.3 summarizes the toxicity endpoints us ed to assess the risk of fluroxypyr-MHE to terrestrial organisms. The data indicates that fluroxypyr-MHE ha s low toxicity to terrestrial animals. Acute and sub-acute toxicity data ca tegorizes fluroxypyr-MHE as practically nontoxic to birds and mammals. A honey bee contact t oxicity study shows that fluroxypyr-MHE is practically nontoxic to bees (MRID 421373-14). A honey bee acute oral toxicity study has not been submitted to EPA, but the PPDB database of the University of Herfordshire 18 

### , as well as material safety data sheets fo r products containing fluroxypyr-MHE 19 

### , suggest low toxicity to the honey bee via oral exposure (LD 50 

### > 100 μg/bee). An avian reproduction study with the mallard found that fluroxypyr-MHE reduces egg production at dietary concentrations as low as 500 mg a.i./kg-diet, establishing the NOAEL at 250 mg a.i./kg-diet. Th e selected NOAEC for chronic toxicity to mammals based on frank sublethal e ffects is 300 mg a.i./kg- bw based on mortality, decreased body weight, and decrea sed food consumption (MRID 44094901).

Phytotoxicity testing with flur oxypyr-MHE showed that the most sensitive species were cotton

and cucumber. The IC 25 

### was 0.075 lb a.i./A for effects to cucumber in the seedling emergence study, and 0.0012 lb a.i./A for effects to cotton in the vegetative vigor study. The lowest NOAEC

was 0.0010 lb a.i./A for effects to co tton in the vegetative vigor study.

The LOD of fluroxypyr-MHE and fluroxypyr acid resi dues in soil (3 μg/kg) are not sufficient for identifying the presence or absence of fluroxypy r-MHE at levels equal to the toxicological

18 Pesticide Property Database (PPDB). Univer sity of Herfordshire. Developed by the Agriculture & Environment Research Unit (AERU) , University of Hertfordshire, 2006-2013. , available at http://sitem.herts.ac.uk/aeru/ppdb/en/index.htm

. 19 Acute oral toxicity data for the honey bee is provided in the Material Safety Data Sheet for several formulated products, for example Widematch®, available at http://ws.greenbook.net/Docs/Msds/M75292.pdf

.

### 28

endpoints for terrestrial plants. Therefore, it is possible that effects could occur following the application of fluroxypyr-MHE with out being able to detect the presence of the chemical. The LOD of fluroxypyr-MHE residues in water (0.05 μg/L) is sufficient based on data currently

available. If more sensitive a quatic species are identified a new method may be needed in order

to insure residues of levels of toxi cological concern can be detected.

Table IV.3. Most Sensitive Endpoints from Terrestrial Toxicity Studies for FluroxypyrMHE

Taxonomic

Group Study Type Surrogate Species Toxicity Value (units in terms of active ingredient and

acid equivalence) Acute Toxicity

Classification Source (Study Classification)

Birds 1 Acute Bobwhite ( Colinus virginianus )

and Mallard ( Anas platyrhynchos ) LD 50 >2000 mg a.i./kg-bw (>1389 mg a.e./kg-bw) No mortality or signs of toxicity were observed. Practically

nontoxic 40244546

40244516 (Acceptable)

Sub-acute dietary Bobwhite LC 50 >5000 mg a.i./kg-diet (>3470 mg a.i./kg-diet) No mortality or signs of toxicity were observed. Practically

nontoxic 40244517 (Acceptable)

Chronic Mallard NOAEC 250 mg a.i./kg-diet (174 mg a.e./kg-diet)

LOAEC 500 mg a.i./kg-diet (347 mg a.e./kg-diet) Endpoint: egg production -- 42137304 (Acceptable)

Mammals Acute Oral Laboratory rat ( Rattus norvegicus ) LD 503160 mg product/kgbw (809 mg a.i./kg-bw or 562 mg a.e./kg-bw) Practically

nontoxic 44080329

Acute

Dermal Laboratory rat LD 50 >5000 mg a.i./kg-bw (>3470 mg a.e./kg-bw) Toxicity Category IV 47934606

Acute

Inhalation Laboratory rat LC 50 >2.09 mg a.i./L (>1.45 mg a.e./L) Toxicity Category IV 47888703

### 29

Taxonomic

Group Study Type Surrogate Species Toxicity Value (units in terms of active ingredient and

acid equivalence) Acute Toxicity

Classification Source (Study Classification)

Chronic Laboratory rat NOAEL 300 mg a.i./kg-bw/day (6000 mg a.i./kg-diet or 4170 mg a.e./kg-diet)

LOAEL 600 mg a.i./kg-bw/day (12,000 mg a.e./kg-diet

or 8330 mg a.e./kg-diet) Endpoint: Pup survival and weight gain -- 44094901

Insects Acute

contact Honey bee ( Apis mellifera L. ) LD 50 >25 μg a.i./bee (>17 μg a.e./bee) (mortality < 10% in all treatment groups) Practically

nontoxic 42137314

Terrestrial plants Seedling Emergence 2 Dicots:

Cucumber NOAEC

0.031 lb a.i./A (0.022 lb a.e./A)

EC 25 0.075 lb a.i./A (0.052 lb a.e./A) Endpoint affected: Visual signs of phytotoxicity -- 44080335 (Acceptable)

Monocots: Ryegrass NOAEC

0.124 lb a.i./A (0.0861 lb a.e./A)

EC 25 >0.25 lb a.i./A (>0.17 lb a.e./A) Endpoint affected: Visual signs of phytotoxicity -- 44080335 (Acceptable)

Terrestrial plants Vegetative Vigor 2 Dicots:

Cotton NOAEC

0.0010 lb a.i./A

0.00069 lb a.e./A

EC 25 0.0012 lb a.i./A

0.00083 lb a.e./A Endpoint affected: Visual signs of phytotoxicity -- 44080335 (Acceptable)

### 30

Taxonomic

Group Study Type Surrogate Species Toxicity Value (units in terms of active ingredient and

acid equivalence) Acute Toxicity

Classification Source (Study Classification)

Monocots:

Onion NOAEC

0.062 lb a.i./A

0.043 lb a.e./A

EC 25 0.124 lb a.i./A

0.0861 lb a.e./A Endpoint affected: Visual signs of phytotoxicity -- 44080335 (Acceptable)

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

2 The test was conducted with an unidentified en d-use product containing 26.9% fluroxypyr-MHE.



### Table IV .4 

### summarizes the toxicity endpoints used to assess the risk of fluroxypyr acid to terrestrial animals and plants. As for fluroxypyr-M HE, acute toxicity tes ting classifies fluroxypyr acid as practically nontoxic to birds, mammals, and bees. No chronic av ian toxicity data are available for fluroxypyr acid. A s upplemental vegetative vigor study indicates that fluroxypyr acid shows similar or greater toxicity to dico tyledonous plants than that of fluroxypyr-MHE, while having relatively low toxicity to monoc otyledonous plants. Due to numerous guideline deviations, the EC 25 

### results obtained from this study are uncertain and should not be used for risk assessment (see DERs for MRID 44094902).

The vegetative vigor study for fluroxypyr acid also provides limite d data on the phytotoxicity of fluroxypyr-MP and fluroxypyr-DCP (MRID 44094902). Seedling emergence and vegetative vigor using four dicots (cotton, radish, soybea n, and sunflower) and thr ee monocots (corn, wheat, and bentgrass) were tested for these transfor mation products. These studies are classified as

invalid as tier 2 studies but supplemental for tier 1. These studies demonstrate that exposure to fluroxypyr-MP and fluroxypyr-DCP at rates up to 0.50 lb a.i./A are not toxic to non-target plants (NOAEL = 0.50 lb a.i./A for all test species).

Table IV.4. Most Sensitive Endpoints from Terrestrial Toxicity Studies for Fluroxypyr

Acid

Taxonomic

Group Study Type Surrogate Species Toxicity Value Acute Toxicity

Classification Source (MRID)

Birds Acute Bobwhite and

mallard LD 50 > 2000 mg a.e./kgbw Practically

nontoxic 40244514

40244515 (Acceptable)

Sub-acute dietary Bobwhite LC 50 > 5000 mg a.e./kgdiet Practically

nontoxic 40244547 (Acceptable)

Chronic Not available

### 31

Taxonomic

Group Study Type Surrogate Species Toxicity Value Acute Toxicity

Classification Source (MRID)

Mammals Acute Laboratory Rat LD 50 = 2408 mg a.e./kgbw (males)

LD 50 > 3000 mg a.e./kgbw (males) Practically

nontoxic

Chronic Laboratory Rat Frank effects LOAEL > 10,000 mg a.e./kg-diet NOAEL = 10,000 mg a.e./kg-diet (No effects observed) -- 40244509 (Acceptable)

Insects Acute contact Honey bee ( Apis mellifera

L. ) LD 50 > 25 μg a.e./bee Practically

nontoxic 421373134

Terrestrial plants Seedling Emergence Monocots:

wheat EC 25 = 0.074 lb a.e./A (NOAEC not determined) -- 44094902 (Supplemental 1 )

Dicots:

sunflower EC 25 = 0.024 lb a.e./A (NOAEC not determined) -- 44094902 (Supplemental 1 )

Vegetative Vigor Monocots:

Corn and wheat EC 25 > 0.50 lb a.e./A (NOAEC not determined) -- 44094902 (Supplemental 1 )

Dicots: Soybean EC 25 = 0.00067 lb a.e./A (NOAEC not determined) -- 44094902 (Supplemental 1 )

1 This study was classified as invalid as a tier 2 study but supplemental as a tier 1 study. The study tested only 6 species (corn, wheat, sunflower, cotton, soybean, and radish), did not determin e NOAECs, and had other guid eline deviat ions. The EC 25 values obtained from this study are approximate, should not be used for quantitative risk assessment, an d should not be compared with results from acceptable phytotoxicity studies.



### Table IV.5. Mammalian Toxicity Studies for Formulated Products Containing Fluroxypyr-MHE

Formulation Study Type Surrogate Species Toxicity Value (all units in terms of

active ingredient) Acute Toxicity

Classification Source (MRID)

Dicamba (8.47%) andFluroxypyrMHE (11.1%)

EC Acute Oral Laboratory Rat LD 50 > 5000 mg a.i./kg-bw (females) Practically nontoxic, Toxicity Category IV 47619803 (Acceptable)

Acute

Dermal Laboratory Rat LD 50 > 5000 mg a.i./kg-bw (males)

LD 50 > 5000 mg a.i./kg-bw (females) Toxicity Category IV 47619804 (Acceptable)

Acute

Dermal Laboratory Rat LD 50 > 2.52 mg a.i./L (males)

LD 50 > 2.52 mg a.i./L (females) Toxicity Category IV 47619805 (Acceptable)

1 The study does not provide sufficient information to convert the toxicity values to lb a.i./A.

### 32

B. Ecological Incidents

A preliminary review of the Ecol ogical Incident Information Syst em (EIIS, version 2.1.1) in June 2014 identified 12 ecological incide nts of adverse field effects to non-target organisms which were attributed to use fluroxypyr-MHE. All of the incidents involved damage to plants. A search of the Avian Monitoring Information System (AIM S), which is maintained by the American Bird Conservancy, did not identify any avian incide nt associated with the use fluroxypyr-MHE

Of the plant damage incidents, nine incidents we re associated with appl ication of an herbicide product containing fluroxypyr-MHE directly to the crop that was damaged. The other three incidents involved damage allegedly caused by sp ray drift of a product a pplied to an adjacent crop. These incidents indicate that off-site movement of herbicide products containing fluroxypyr-MHE are capable of damaging dico tyledonous plants. Since these products all contain multiple herbicidal active ingredients, the contri bution of fluroxypyr-MHE (or the corresponding acid) to the observe d phytotoxicity is uncertain and the observed damage may be the result of other active ingred ients or additive toxicity.

Two carryover incidents reported for Goldsky He rbicide suggest that th is product may persist enough in soil to cause damage to crops plan ted the next growing season. However, the carryover toxicity may have been caused by two sulfonylurea activ e ingredients, pyroxsulam and

florasulam.

Table IV.6

. Incidents Associated with Off-Site Movement of Flur oxypyr-MHE Residues

Incident

# Date Location Use Site Crop Damaged Certainty Active Ingredients Comments

I020627-

003 June 1,

2001 Grant County,

WA Timothy hay Wine grapes Possible Fluroxypyr 1
2,4-D The applicators were in violation for applying restricted-use pesticides

without a license.

I014266-

002 July 3,

2003 Manitoba,

Canada Unidentified Strawberries Possible fluroxypyrMHE, 2,4-D,clodinafoppropargyl A temperature inversion

was believed to have caused spray drift from an adjacent field.

I015748-

017 June 6,

2004 Richland County,

MT Wheat Sugar beets Probable MCPA, 2- ethylexyl

ester,fluroxypyrMHE, and clopyralid The wheat field had been sprayed with the herbicide product Widematch M (Reg. No. 62719-513). Plants exhibited symptoms associated with growth regulator herbicides.

I024789-

001 June 16,

2011 Versailles,

KY Pasture Black locust

trees Probable FluroxypyrMHE, triclopyr-BEE Black locust trees along

a fence lines were severely damaged following application of Pasturegard Herbicide (Reg. No. 62719-477) to an adjacent pasture.

I024792-

004 March 26,

2011 Moses Lake, WA Not reported Mustard Possible FluroxypyrMHE, A farmer alleged that mustard plants were injured by carryover of

### 33

pyroxsulam,

florasulam an application of Goldsky Herbicide (62719-582)10 months

earlier.

I024792-

025 April
20,

2011 Scobey,

MT Not reported Lentil Possible FluroxypyrMHE, pyroxsulam,

florasulam A farmer alleged that lentils were injured by carryover of an application of Goldsky Herbicide (62719- 582)11 months earlier.

1 The report did not specify if fluroxypyr was applied fluroxypyr acid or fluroxypyr-MHE.



### In addition to the incidents reco rded in EIIS and AIMS, the Agen cy maintains a database which

stores counts of minor incidents th at pesticide registrants record in quarterly aggregated incident reports. Ecological incidents recorded in these ag gregated reports include those categorized as ‘minor fish and wildlife’ (W-B), ‘minor plant’ (P-B), and ‘other non-target’ (ONT) incidents. A

review of this database in June 2014 identified a total of 59 incidents of minor plant damage attributed to use of a produc t containing fluroxypyr-MHE ( Table IV.7 ). Most of the herbicide products associated with the incidents contained one or more active ingredients in addition to fluroxypyr-MHE, although there were three that contained only fluroxypyr-MHE.

Table IV.7. Incidents Reported by Pestic ide Registrants for Products Containing Fluroxypyr-MHE

Product Name Reg. # Date Range Incident

Number Active Ingredients Number of

Incidents From To

Attain (Canadian) 12/1/2010 11/30/2011 024333 -

00043 Fluroxypyr-MHE 2,4-D, 2-ethylhexyl ester 2

Attain XC (Canadian) 12/1/2010 11/30/2011 024333 -

00045 Fluroxypyr-MHE 1

Cleanwave 62719-

525 8/1/2009 8/31/2009 023787 -

00522 Fluroxypyr-MHE Aminopyralid, 1

Goldsky

Herbicide 62719-

582 12/1/2011 11/30/2012 024791 -

00007 Fluroxypyr-MHE Pyroxsulam

Florasulam 3

Momentum

FX2 Herbicide 228-447 4/1/2011 6/30/2011 023050 -

00006 Fluroxypyr-MHE Triclopyr, triethylamine salt 2,4-D, triisopropanolamine salt 1

Octtain XL

Herbicide (Canadian) 12/1/2012 11/30/2013 025992 -

00007 Fluroxypyr-MHE 2,4-D, 2-ethylhexyl ester 1

Pasturegard 62719-

477 12/1/2010 11/30/2011 024333 -

00061 Fluroxypyr-MHE Triclopyr, butoxyethyl ester 1

Prestige

Herbicide (Canadian) 12/1/2010 11/30/2011 024333 -

00048 Fluroxypyr-MHE Clopyralid MCPA, 2-ethylhexyl ester 29

Spotlight

Herbicide 62719-

308 12/1/2004 11/30/2005 016962 -

00061 Fluroxypyr-MHE 1

Starane F 62719-

285 4/1/2000 6/30/2000 010424 -

00013 Fluroxypyr-MHE 1

Stellar

Herbicide (Canadian) 12/1/2010 11/30/2011 024333 -

00050 Fluroxypyr-MHE

Florasulam MCPA, 2-ethylhexyl ester 1

12/1/2012 11/30/2013 025992 -

00011 1

Tandem

Herbicide 12/1/2010 11/30/2011 024333 -

00051 Fluroxypyr-MHE Pyroxsulam 6

### 34

(Canadian) 12/1/2012 11/30/2013 025992 -

00013 2

4/1/2013 6/30/2013 025643 -

00074 1

Unknown 4/1/2004 6/30/2004 015419 -

00604 Fluroxypyr-MHE

MCPA Clopyralid 1

Widematch

Herbicide 062719-

00512 12/1/2004 11/30/2005 016962 -

00064 Fluroxypyr-MHE Clopyralid, monoethanolamine

salt 3

12/1/2012 11/30/2013 025992 -

00014 2

Widemtch

Herbicide 062719-

00512 12/1/2009 11/30/2010 023787 -

00536 Fluroxypyr MHE,Clopyralid, monoethanolamine salt, 1

TOTAL 59



### C. Exposure Pathways of Concern

Based on the use pattern and environmental fate ch aracteristics of this pesticide, the following exposure pathways are expected to be most rele vant for determining exposure and potential risk to non-target organisms:

 Direct spray

 Spray drift

 Runoff (primarily acid)

 Leaching to groundwater followed by irrigation (primarily acid)



### In addition, terrestrial an imals that use treated fields may be exposed to fluroxypyr acid from consuming contaminated plants and inverteb rates, dermal absorp tion, and drinking from contaminated puddles. With use of granular products, terrestrial animals also may be exposed by consumption of granules that are on the soil surface or on vegetation. Drinking water exposure pathways were screened using SIP (Screening Imbibition Program) and indicate that drinking from contaminated puddles is a pathway of potential concern for fluroxypyr-MHE and fluroxypyr acid residues. The potential for i nhalation exposure was screened using STIR (Screening Tool for Inhalation Ri sk). Based on this analysis i nhalation is a pathway of low concern (no LOC exceedances are expected) for both fluroxypyr acid and fluroxypyr-MHE. Input parameters and outputs from SIP and STIR are provided in APPENDIX E . SIP and STIR

are described in detail at: http://www.epa.gov/oppefed1/mo dels/terrestrial/index.htm

.

While fluroxypyr-MHE and fluroxypyr acid are expected to be taken up by plants and translocated as fluroxypyr acid, concentrations in nectar a nd pollen are unknown. However, contact exposure to pollinators is expected to be primary as a result of direct spray onto flowering weeds.



## V. ANALYSIS PLAN

A. Ecological Risk Assessment

1. Stressors of Concern

Both fluroxypyr-MHE and fluroxypyr acid are consid ered the stressors of concern; together using a total toxic residue approach for plan ts and individually for all other taxa.

### 35

2. Measures of Exposure

In order to estimate risks of fl uroxypyr-MHE and fluroxypyr acid residues exposure to aquatic and terrestrial organisms, all exposure modeling and resulting risk conclusions will be made based on maximum application rates, applic ation methods, and any mitigation measures specifically indicated on the label. The models that will be used to predict the estimated environmental concentrations (EECs) are discussed on OPP’s model website. 20 

### These models include: PRZM (Pesticide Root Zone Model) and VVWM (Variable Volume Water Model), PRZM-groundwater (GW), PFAM (Pes ticides in Flooded Applicati on Model), AgDrift, AgDisp, T-REX, TerrPlant, SIP (Screen ing Imbibition Program), and STIR (Screening Tool for Inhalation Risk).

Available monitoring data will be evaluated a nd considered in an assessment conducted for Registration Review.

Exposure to terrestrial animals is estimated using the Terrestrial Residue Exposure (T-REX) model. Exposure to terrestrial pl ants is estimated using the Te rrPlant model. For terrestrial plants, exposure is based on the calculated ma ximum application rates with assumed exposure from runoff, but not spray drift. A descri ption of these models may be found at: http://www.epa.gov/pesticides/science/models_db.htm

.

3. Measure of Effects

Toxicity data presented in Section 4.C.2 of this problem formulat ion will be used in the quantitative risk assessment. Any additional toxic ity data submitted by the registrant, as well as relevant toxicity information found in the open literature, will also be considered.

4. Integration of Exposure and Effects

Exposure and effects will be integrated in an updated risk assessment, incorporating new data and information obtained since the previous ri sk assessments were conducted. Since previous risk assessments have consistently identified nonta rget plants as being at greatest risk, a risk assessment will be conducted for aquatic and te rrestrial plants using the EPA’s updated risk assessment methods. For terrestrial plants, the ri sk assessment will incorporate new TEP data on phytotoxicity and may utilize improved methods for modeling exposure and risk to terrestrial plants. In addition, a new study on the persisten ce of fluroxypyr residues in compost will allow the EPA to assess with improved certainty the potentia l for persistent fluroxypyr residues in compost to harm crops and garden plants.

For aquatic plants, the risk asse ssment will utilize data from a ne w study on toxicity to the most sensitive aquatic test speci es, the freshwater diatom Navicula pelliculosa . The results from the current supplemental study with this sp ecies (MRID 44527201) are c onsidered unreliable

because the solvent control solutions were contamin ated with the test material. Furthermore, the response of the diatoms in the medium control wa s much stronger than th ose in solvent control and the lower treatment levels, an unexpected re sult that suggests the st udy was affected by the

solvent contamination or some ot her extraneous factor. Therefore, a repeat of this study may

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

### 36

result in a different toxicity endpoint, which ma y result in different RQ values for nonvascular aquatic plants.

Another source of new information that may affect the aquatic plant risk assessment is a recent published paper reporting the toxicity of fluroxypyr-MHE to the aquatic macrophage, Myriophyllum spicatum (Mohr et al ., 2013). This species is consid ered a more preferred test species than duckweed ( Lemna gibba ) for testing herbicides th at are auxin analogs, like fluroxypyr-MHE, because these herbicides are known to have toxicity that is specific to dicots,

and M. spicatum is a dicot whereas duckweed is a monocot (Mohr et al ., 2013). As expected, the

studies with M. spicatum exhibited greater toxicity than the duckweed study used in the previous assessment. Depending on which M. spicatum study is considered, the IC 50 

### was 3.3 to 15.6 times

lower than the duckweed IC 50 

### . This would result in RQs that would be higher by the same

factors.

Some previous risk assessments have identified risk to aquatic invertebrates that exceed the LOC for listed species. An aquatic risk assessment will be conducted for these species using the most current use information for fluroxypyr-MHE, and its environmental fate data and toxicity, to

better define and characterize potential adverse effects to listed aquatic invertebrates.

Additional data on toxicity of fluroxypyr-MHE to the honeybee will allow for a more complete assessment of potential risk to insect pollinator s. Currently, data are only available for acute toxicity from acute contact exposure. Additional data on acute oral exposure will allow assessing potential risk to bees from i ngestion of nectar and/or pollen contaminated with fluroxypyr. [In addition, data will be obtained from tier-1 honeybee studies with chronic exposure to adult bees

and larval bees. These studies will allow evalua tion of acute and chroni c effects on bee larvae and chronic effects on adult bees.]

Finally, a review of the open li terature may provide additional information on the environmental fate and ecotoxicity of fluroxypyr-MHE and fluroxypyr acid. Any new information from published literature may be used to refine the quantitative risk assessment or to expand upon the qualitative characterization of risk.

5. Endangered Species Assessments

In November 2013, the EPA, along with the U. S. Fish & Wildlife Service (USFWS), the

National Marine Fisheries Service (NMFS) (collectively, the Servi ces), and the U.S. Department of Agriculture (USDA) released a summary of th eir joint Interim Approaches for assessing risks to listed species from pesticides. The Interim Ap proaches were developed jointly by the agencies in response to the National Academy of Sc iences’ (NAS) recommendations and reflect a common approach to risk assessment shared by th e agencies as a way of addressing scientific differences between the EPA and the Services. The NAS report 21 

### outlines recommendations 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 Endangered Species Act (ESA) and FIFRA. The join t Interim Approaches were released prior to a stakeholder workshop held on November 15, 2013. In addition, the EPA presented the joint

21 http://www.nap.edu/catalog.php?record_id=18344

### 37

Interim Approaches at the December 2013 Pes ticide Program Dialogue Committee (PPDC) and

State-FIFRA Issues Research a nd Evaluation Group (SFIREG) mee tings, and held a stakeholder workshop in April 2014, allowing additional opport unities for stakeholders to comment on the Interim Approaches. As part of a phased, it erative process for developing the Interim Approaches, the agencies will also consider public comments on the Interim Approaches in connection with the development of upcoming Regi stration Review decisions. The details of the joint Interim Approaches are contained in th e white paper “Interim Approaches for NationalLevel Pesticide Endangered Sp ecies Act Assessments Based on the Recommendations of the National Academy of Sciences April 2013 Report,” 22 

### dated November 1, 2013.

Given that the agencies are continuing to de velop and work toward implementation of the Interim Approaches to assess the potential risk s of pesticides to listed species and their designated critical habitat, the ecological risk assessment supporting the proposed interim registration review decision fo r fluroxypyr-MHE is not expected to contain a complete ESA analysis. Once the agencies have fully vetted the scientific methods necessary to complete risk assessments for endangered and threatened (listed) species and their designated critical habitats, these methods will be applied to subsequent anal yses for fluroxypyr-MHE as part of completing this registration review.

6. Endocrine Disruptor Screening Program

Fluroxypyr-MHE was not included in the first group of 67 chemicals that were issued an order to conduct Tier 1 EDSP testing, nor in the second revi sed list of 109 chemicals issued for the next phase of Tier 1 testing. For additiona l information the EDSP program, visit http://www.epa.gov/endo/

.

B. Drinking Water

Although there are number of uses for which a drinking water assessment has not been completed as well as uses that have a number of uncertainties associated with the label language (e.g., unknown number of yearly applications) an updated drinking water assessment for registration review is not planed at this time. The most recent drinking water assessment conducted on rice is expected to provide very co nservative EDWCs and the results are expected to be much higher than that of any other uses cu rrent registered, even if these uncertainties were

taken into account.



## VI. PRELIMINARY IDENTIFICATION OF DATA GAPS

A. Environmental Fate

Table VI.1 identifies environmental fate studies by MRID that offer data for each guideline requirement, as well as study classi fications and whether or not furt her data are needed in order to support risk assessment.

22 http://www.epa.gov/espp/2013/nas.html

### 38

Table VI.1. Environmental Fate Data for Fluroxypyr-MHE and Fluroxypyr Acid

OCSPP

Guideline Data Requirement Submitted

Studies (MRID) Study

Classifications Are data

needed to

conduct risk

assessment? Comments

835.2120 Hydrolysis 4 0244539 Acceptable No
--

835.2240 Aqueous Photolysis 44080342 Acceptable No --

835.2410 Soil Photolysis 4 4080343 Acceptable No --

835.4100 Aerobic Soil

Metabolism 42137317 Acceptable No --

835.4200 Anaerobic Soil

Metabolism No data are available No --

835.4300 Aerobic Aquatic

Metabolism 44080345 Acceptable No

--

835.4400 Anaerobic Aquatic

Metabolism 44080344 supplemental No --

835.1230

835.1240 Adsorption/ desorption and Leaching 42137319 acceptable No --

835.1410 Volatility – Laboratory No data are available No Fluroxypyr-MHE and fluroxypyr are not expected to be volatile based on vapor pressure and Henry’s Law

Constant.

835.6100 Terrestrial Field Dissipation 44080347 Supplemental

No -- 44896702 Acceptable

45204201 Acceptable

45204202 Acceptable

835.6200 Aquatic Field Dissipation 48581303 Scientifically valid; study is currently under

review No

850.6100 Analytical

Method in Soil 44080346 (ECM

Acceptable Yes Data are available for fluroxypyr acid, fluroxypyr-DCP and fluroxypyr-MP; however , the LOD/LOQ are not lower than the most sensitive terrestrial plant endpoint. No data are available for fluroxypyr-MHE. 44896703

(ECM)

45084601

(ILV)

Analytical

Method in

Water 48581303 (ECM) Acceptable Yes No ILV has been provided for this method.


### ILV No data Yes

165-4 (850.1730) Fish Bioconcentration 44080348 supplemental No -- 44605403

### 39

OCSPP

Guideline Data Requirement Submitted

Studies (MRID) Study

Classifications Are data

needed to

conduct risk

assessment? Comments

Nonguideline Compost 45833601 Upgradeable Yes Several deficiencies were identified in the submitted study including: 1) There are no methods including an independent lab validation or control spikes to support the analytical methods used in the study; 2) A discussion of how sampling withdrawal (material reduction), etc. followed by sample consolida tion impacted the results is needed; 3) While analytical replicate samples were conducted, replicate experiment samples (multiple compost piles) were not provided to assess the experimental variability; 4) The representation of the composting method used in the study was not provided; and 5) The study only looked for fluroxypyr acid. If these deficiencies cannot be addressed a new study is needed to assess the fate of fluroxypyr-MHE and fluroxypyr acid in compost materials.



### B. Ecological Effects

Table VI.2 and

Table VI.3 identify ecological effects studies for aqua tic and terrestrial organisms, respectively, that provide data for each gui deline requirement. These tables also identify the study

classifications and indicate wh ether EFED recommends requesting additional data in order to support risk assessment. Rationale for requests fo r the additional data is presented below the

tables.

EFED recommends requesting the following add itional data for assessing ecological risk:

 (GLN 850.4500) Algal toxicity test with a freshwater diatom

 GLN 850.4100) Seedling emergence test with 10 plant species using a TEP containing fluroxypyr-MHE

 (GLN 850.4150) Vegetative vigor test with 10 plant species using a TEP containing fluroxypyr-MHE

Table VI.2. Aquatic Ecological Effects Data for Fluroxypyr-MHE and Fluroxypyr Acid

OCSPP

Guideline Data Requirement Submitted

Studies (MRID) Test Species Study

Classifications Are data

needed to

conduct risk

assessment? Comments



### F LUROXYPYR 

### -MHE

850.1010

850.1020 Freshwater

invertebrate acute toxicity 40244520 Water flea Acceptable No --

42137308 Water flea Acceptable

850.1035

850.1045 Saltwater

crustacean acute toxicity 44080313 Grass shrimp Acceptable No --

42137311 Pink shrimp Supplementary

850.1025 45725801 Eastern oyster Acceptable No

### 40

OCSPP

Guideline Data Requirement Submitted

Studies (MRID) Test Species Study

Classifications Are data

needed to

conduct risk

assessment? Comments

850.1055 Saltwater

mollusk acute toxicity 44080310 Eastern oyster Supplemental --

850.1075 Freshwater

fish acute toxicity 44080307 Bluegill

sunfish Acceptable No

--

40244522 Rain bow trout Acceptable

40244523 Golden orfe Supplemental

40244525 Rainbow trout Supplemental

850.1075 Saltwater fish acute toxicity 44080308 Sheepshead

minnow Acceptable No

--

42137309 Atlantic

silverside Supplemental

850.1300 Freshwater

invertebrate life cycle 44080314 Water flea Supplemental No --

850.1350 Saltwater

invertebrates life cycle (None) (N/A) (N/A) No --

850.1400 Freshwater

fish early-life stage (None) (N/A) (N/A) No The fish early life-stage study conducted with fluroxypyr acid (MRID 48559401) provides

sufficient information for this guideline.

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

850.1500 Fish life cycle (None) (N/A) (N/A) No --

850.4400 Aquatic plant toxicity test

with duckweed ( Lemna spp.) 45011602 Lemna gibba Acceptable No --

44080338 Lemna gibba Acceptable

44744001 Lemna gibba Supplemental

850.4500 Algal toxicity with green algae 45011603 Kirchneria subcapitata Acceptable No --

44080340 Kirchneria subcapitata Acceptable

42137312 Kirchneria subcapitata Supplemental

### 41

OCSPP

Guideline Data Requirement Submitted

Studies (MRID) Test Species Study

Classifications Are data

needed to

conduct risk

assessment? Comments

850.4500 Algal toxicity

with

freshwater

diatom 44080339

44527201 Navicula pelliculosa Supplemental Yes This test is needed to replace the inadequate supplemental studies and to provide reliable

EC 50 and NOAEC for Navicula pelliculosa

, which is the most sensitive test species of nonvascular plants.

850.4500 Algal toxicity

with saltwater

diatom 44080337 Skeletonema

costatum Acceptable No --

850.4550 Cyanobacteria 44080336 Anabaena flos-aquae Acceptable No --



### F LUROXYPYR 

### A CID

850.1010

850.1020 Freshwater

invertebrate acute toxicity 40244521 Water flea Acceptable No --

40244524 Water flea Acceptable

850.1035

850.1045 Saltwater

crustacean acute toxicity 44080312 Grass shrimp Acceptable No --

850.1025

850.1055 Saltwater

mollusk acute toxicity 44080311 Eastern oyster Acceptable No --

42137310 Eastern oyster Invalid

850.1075 Freshwater

fish acute toxicity 42137306 Bluegill

sunfish Acceptable No --

42137307 Rain bow trout Acceptable

40244518 Rain bow trout Acceptable

44080309 Inland

silverside Acceptable

40244519 Golden orfe Acceptable

850.1075 Saltwater fish acute toxicity 44080309 Atlantic

silverside Acceptable No --

850.1300 Freshwater

invertebrate life cycle (None) (N/A) (N/A) No

--

850.1350 Saltwater

invertebrates life cycle (None) (N/A) (N/A) No

--

850.1400 Freshwater

fish early-life stage 48559401 Fathead

minnow Acceptable No --

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

### 42

OCSPP

Guideline Data Requirement Submitted

Studies (MRID) Test Species Study

Classifications Are data

needed to

conduct risk

assessment? Comments

850.1500 Fish life cycle (None) (N/A) (N/A) No

850.4400 Aquatic plant toxicity test

with duckweed ( Lemna spp.) 44094902 Lemna gibba Invalid No Testing done with the fluroxypyr-MHE is adequate for assessing

risk.

850.4500 Algal toxicity with green algae 40244526 Chorella vulgaris Supplemental

No

--

42164501 Kirchneria

subcaitatum Invalid

850.4500 Algal toxicity

with

freshwater

diatom (None) (N/A) (N/A) No

--

850.4500 Algal toxicity

with saltwater

diatom (None) (N/A) (N/A) No --

850.4550 Cyanobacteria (Non e) (N/A) (N/A) No --



### Table VI.3. Terrestrial Ecological Effects Da ta for Fluroxypyr-MHE and Fluroxypyr Acid

OCSPP

Guideline Data Requirement Submitted

Studies (MRID) Test Species Study

Classifications Are data

needed for

risk

assessment? Current Additi onal Data

Need



### F LUROXYPYR 

### -MHE

850.2100 Avian oral toxicity with quail or duck 40244546 Bobw hite Acceptable No --

40244516 Mallard Acceptable

850.2100 Avian oral toxicity with passerine

(None) (N/A) (N/A) No Because fluroxypyr-MHE has been shown to have very low acute toxicity to birds and mammals, acute testing with a passerine bird is not

needed.

850.2200 Avian dietary toxicity 40244517 Bobwh ite Acceptable No --

42137301 Mallard Acceptable

850.2300 Avian reproduction 42137303 Bobw hite Acceptable No --

42137304 Mallard Acceptable

Nonguideline Avian inhalation (None) (N/A) (N/A) No --

850.3020 Honey bee acute contact toxicity 42137313 Honey bee Acceptable No --

40244527 Honey bee Supplemental

### 43

OCSPP

Guideline Data Requirement Submitted

Studies (MRID) Test Species Study

Classifications Are data

needed for

risk

assessment? Current Additi onal Data

Need

Nonguideline Honey bee acute oral study (None) Honey bee (N/A) Yes This study appears to have already been conducted and

submitted to EU countries. The submittal of this study to the EPA would be helpful for assessing risk to insect pollinators.

Nonguideline Honey bee,

chronic oral toxicity to adults (None) Honey bee (N/A) Yes This study is now needed for assessing pesticide risk to

bees.

Nonguideline Honey bee,

chronic oral toxicity to larvae (None) Honey bee (N/A) Yes This study is now needed for assessing pesticide risk to

bees.

850.3030 Honey bee residue on foliage (None) (N/A) (N/A) Reserved pending

results of

tier I studies --

850.3040 Field testing for pollinators (None) (N/A) (N/A) Reserved pending

results of

tier I studies --

850.4100 Seedling Emergence and Seedling Growth 44080335 10 species Acceptable Ye s The TEP used in this study was not reported. Additional testing may be needed to

assess risk of TEPs to terrestrial plants.

850.4150 Vegetative Vigor 4408033 5 10 species Acceptable Yes The TEP used in this study was not reported. Additional testing may be needed to

assess risk of TEPs to terrestrial plants.

### 44

F LUROXYPYR ACID

850.2100 Avian oral toxicity with quail or duck 40244515 Bobw hite Acceptable No --

40244514 Mallard Acceptable

850.2100 Avian oral toxicity with passerine (None) (N/A) (N/A) No Because fluroxypyr acid has been shown to have very low acute toxicity to birds and mammals, acute testing with a passerine bird is not needed.

850.2200 Avian dietary toxicity 40244547 Bobwh ite Acceptable No --

42137302 Mallard Acceptable

850.2300 Avian reproduction (None) (N/A) (N/A) No --

(None) (N/A) (N/A)

Nonguideline Avian inhalation (None) (N/A) (N/A) No --

850.3020 Honey bee acute contact toxicity 42137314 Honey bee Acceptable No --

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

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

850.4100 Seedling Emergence and Seedling Growth 44094902 Corn, wheat, sunflower,

cotton, soybean, and

radish Invalid for Tier 2, Supplemental

for Tier 1 No

-- 850.4150 Vegetative Vigor 44094902 Corn, wheat, sunflower,

cotton, soybean, and

radish Invalid for Tier 2, Supplemental

for Tier 1 No



### Limited ecological effects data are available on th e toxicity of two major degradation products of fluroxypyr-MHE, fluroxypyr-pyridinol (4-amino- 3-5,5-dichloro-6-fluoro-2-pyridinol) and fluroxypyr-methylpyridine (4-amino-3,5-dich loro-6-fluoro-2-methylpyridine) ( Table VI.4 ). Results of these studies are presented in Appendix D. The studies submitted provide sufficient information on the toxicity of these degradation pr oducts to terrestrial and aquatic plants for the registration review risk assessmen t. Since the parent compound has low toxicity to terrestrial and aquatic animals, toxicity data with these degrad ates for terrestrial or aquatic animals are not

needed.

### 45

Table VI.4. Aquatic Ecological Effects Data fo r Degradation Products of Fluroxypyr-MHE and Fluroxypyr (acid)

OCSPP

Guideline Data Requirement Submitted

Studies (MRID) Test Species Study

Classifications Are data

needed for

risk

assessment? Current

Additional Data

Need



### 4- AMINO 

### -3-5,5- DICHLORO 

### -6- FLUORO 

### -2- PYRIDINOL

850.4400 Aquatic plant Toxicity

Test with Duckweed ( Lemna spp.) 45011602 Lemna gibba Acceptable No

--

850.4500 Algal toxicity with green algae 45011603 Pseudokirchner ia subcapitata Acceptable No

--

850.4500 Algal toxicity with

freshwater diatom 45011601 Navicula pelliculosa Acceptable No

--

850.4500 Algal toxicity with

saltwater diatom 45011605 Skeletonema

costatum Acceptable No --

850.4550 Cyanobacteria 45011604 Anabaena flos-aquae Acceptable No

--

850.4100 Seedling Emergence and Seedling Growth 44094902 Corn, wheat, sunflower, cotton, soybean,

and radish Acceptable as tier 1 study No --

850.4150 Vegetative Vigor Acceptable as tier 1 study No --



### 4- AMINO 

### -3,5- DICHLORO 

### -6- FLUORO 

### -2- METHYLPYRIDINE

850.4400 Aquatic plant Toxicity

Test with Duckweed ( Lemna spp.) 45011607 Lemna gibba Acceptable No

--

850.4500 Algal toxicity with green algae 44080341 Pseudokirchner ia subcapitata Supplemental No

--

850.4500 Algal toxicity with

freshwater diatom 45011606 Navicula pelliculosa Acceptable No

--

850.4500 Algal toxicity with

saltwater diatom 45011609 Skeletonema

costatum Acceptable No

--

850.4550 Cyanobacteria 45011608 Anabaena flos-aquae Acceptable No

--

850.4100 Seedling Emergence and Seedling Growth 44094902 Corn, wheat, sunflower, cotton, soybean,

and radish Acceptable as tier 1 study No --

850.4150 Vegetative Vigor Acceptable as tier 1 study No --



## VII. REFERENCES (GENERAL)

Mohr, S. J. Schott, D. Maletzki, and A. Hünke n. 2013. Effects of toxicants with different modes

of action on Myriophyllum spicatum in a test system with varying complexity. Ecotox.Environ. Saf. 97:32-39.

### 46

Maltby, L., Arts, G., Heimbach, F., Davies, J., Poulsen, V., Pickl, C., Poulsen, V. 2010. Aquatic Macrophyte Risk Assessment for Pesticides . SETAC Europe Workshop AMRAP, Wageningen Netherlands. CRC Press, USA p. 135.

USEPA. 2004. Overview of the Ecological Risk Assessm ent Process in the Office of Pesticide Programs . January 23, 2004. Office of Pesticid e Programs. Office of Prevention, Pesticides, and Toxic Substances. Available at: http://www.epa.gov/espp/consultation/ecorisk-overview.pdf

USEPA. 2013. EFED Risk Assessment for the Proposed New Use of Fluroxypyr 1- methylheptylester on Rice. Office of Pesticide Pr ogram. Memorandum from the

Environmental Fate and Effects Division to the Registration Divi sion. January 11, 2013.

D396342.

USEPA. 2014. ECOTOX User Guide: ECOT OXicology Database System . Version 4.0.

Available: http:/www.epa.gov/ecotox/47BLIOGRAPHYental Fate Studies Submitted for Fluroxypyr-MHE and FluroxypyreMRIDTestMaterialCitationRemarks40244539fluroxypyr-MHELehmann, R. (1987) The Hydrolysis of Fluroxypyr-MHE inDilute Aqueous Solution: Laboratory Project ID: GH-C 1910.Unpublished study prepared by Dow Chemical U.S.A. 40 p.42137318 2-OctanolLehmann, R. (1991) A Review of 2-Octanol, HydrolysisProduct of Fluroxypyr-1-Methyl-Heptyl Ester: Lab ProjectNumber: GH-C 2607. Unpublished study prepared byDowElanco. 14 p.lysis44080342fluroxypyr-MHECleveland, C.; Holbrook, D. (1992) The Aqueous Photolysisof Fluroxypyr Methylheptyl Ester and Fluroxypyr (Acid) inNatural Sunlight: Lab Project Number: ENV91079.Unpublished study prepared by DowElanco. 95 p.sis44080343fluroxypyr-MHEBatzer, F.; Lubinski, R. (1996) Soil Photolysis of Fluroxypyr1-Methylheptyl Ester in Natural Sunlight: Amended Report:Lab Project Number: ENV91080. Unpublished studyprepared by DowElanco. 79 p.lm42137317fluroxypyr-MHELehmann, R.; Miller, J. (1989) Aerobic Soil Metabolism ofFluroxypyr-MHE: Lab Project Number: GH-C 2149.Unpublished study pre- pared by Dow Chemical U.S.A. 63 p.42137316fluroxypyr-MHELehmann, R. (1988) Formation of Fluroxypyr fromFluroxypyr-MHE by Soil Catalysis: Lab Project Number:GH-C 2068. Unpublished study prepared by Dow ChemicalU.S.A. 26 p.oilm40244540Hawkins, D.; Kirkpatrick, D.; Conway, B.; et al. (1982) TheMetabolism of [Carbon 14]-Dowco 433 MHE in Laboratorystored Soil: Laboratory Project ID: DWC 312/341 8240.Unpublished study pre- pared by Huntingdon ResearchCentre. 144 p.aticm44080345fluroxypyr-MHECleveland, C.; Miller, J. (1993) Aerobic Aquatic Metabolismof Fluroxypyr Methylheptyl Ester: Lab Project Number:ENV91075: Unpublished study prepared by DowElanco,North American Environmental Chemistry Lab. 125 p.uatic44080344fluroxypyr-MHECleveland, C.; Miller, J. (1993) Anaerobic AquaticM t b li f Fl M th lh t l E t L b P j t48GuidelineMRIDTestMaterialCitationRemarks834.4400Number: ENV91075: ENV91075.1. Unpublished studyprepared by DowElanco, North American EnvironmentalChemistry Lab. 108 p.Terrestrial FieldDissipation835.610044080347Formulatedproduct(XRM-5316;26.6%)Poletika, N.; Roberts, D.; Phillips, A.; et al. (1996) TerrestrialField Dissipation of Fluroxypyr: Lab Project Number:ENV92023. Unpublished study prepared by A & L GreatLakes Labs., Inc.; Agvise; and DowElanco. 393 p.40244544Freeman, J. (1985) The Degradation and Leaching ofFluroxypyr in Soil--U.K. 1984: Laboratory Project ID: GHEP-1303R. Unpublish- ed study prepared by Dow ChemicalCo. 159 p.44080346Fluroxypyr,fluroxypyrDCP,fluroxypyr-MPMoore, M. (1996) Determination of Residues of Fluroxypyr((4-Amino-3,5-dichloro-6-fluoro-2-oxy Acetic Acid)Pyridine), Methoxypyridine ((4-Amino-3,5-dichloro-6-fluoro2-methoxy) Pyridine) and 3,5-Dichloropyridinol ((4-Amino3,5-dichloro- 6-fluoro-2-hydroxy) Pyridine) in Soil byCapillary Gas Chromatography Using Mass SelectiveDetection: Lab Project Number: GH-C 4170. Unpublishedstudy prepared by DowElanco, Global EnvironmentalChemistry Lab. 63 p.44896702Attain A:FluroxypyrMHE (27.1 %by weight),fluroxypyr(18.8% a.e.)Roberts, D.; Phillips, A.; Rutherford, L. (1999) FieldDissipation of Fluroxypyr in North Carolina: Lab ProjectNumber: RES98073. Unpublished study prepared by DowAgroSciences LLC. and Stone Environmental Inc. 225 p.45204201Productcontaining27.1%fluroxypyrMHE and18.8%fluroxypyrRoberts, D.; Robb, C. (2000) Terrestrial Dissipation ofFluroxypyr in Oklahoma Sorghum Agriculture: Lab ProjectNumber: 990024. Unpublished study prepared by DowAgroSciences LLC, Crop GuardResearch, Inc. & A&L GreatLakes Laboratories, Inc. 225 p.45204202Roberts, D.; Rutherford, L. (2000) Terrestrial Dissipation ofFluroxypyr in Missouri Sorghum Agriculture: Lab ProjectNumber: 990037. Unpublished study prepared by DowAgroSciences LLC, Stewart Agricultural Research Service,Inc., & A&L Great Lakes Laboratories, Inc. 299 p.49GuidelineMRIDTestMaterialCitationRemarksAquatic FieldDissipation835.620048581303Formulatedproduct GF1784(fluroxypyrMHE)Newcombe, A.; Negley, T.; van Wesenbeeck, I. (2011)Aquatic Dissipation of Fluroxypyr under Dry-Seeded (Texas)and Water-Seeded (California) Rice Production Conditionsafter Two Foliar Spray Applications: Final Report. ProjectNumber: 101622, 101622/OCR. Unpublished study preparedby Pyxant Labs Inc., Agvise Laboratories, Inc. and Arcadis.1292 p.This study iscurrently underreview.Adsorption/Desorption BatchEquilibrium835.123042137319 fluroxypyrLehmann, R.; Miller, J.; Olberding, E. (1988) An Adsorption/Desorption Study of Fluroxypyr: Lab Project Number: GH-C2124. Unpublished study prepared by Dow Chemical U.S.A.74 p.40244541 fluroxypyrTaylor, D. (1985) Study ofthe Leaching Characteristics ofDowco 433 (Fluroxypyr) as Determined in an Aged LeachingStudy: Laboratory Report No.: 4536-295/11. Unpublishedstudy prepared by Hazleton Laboratories Europe Ltd. 120 p.40244542 fluroxypyrTaylor, D. (1985) Study ofthe Leaching Characteristics ofDowco 433 Acid (Fluroxypyr) in Soil: Laboratory ReportNo.: 4537-295/ 12. Unpublished study prepared by HazletonLaboratories Europe Ltd. 112 p.44094903fluroxypyrDCP,fluroxypyr-MPCleveland, C.; Ostrander, J. (1996) Adsorption/DesorptionBatch Equilibrium Partitioning of Methoxypyridine andDichloropyridinol Metabolites of Fluroxypyr: Lab ProjectNumber: ENV95072: GHE-P-4500R: 4V. Unpublished studyprepared by DowElanco North American EnvironmentalChemistry Lab. 150 p.Originallyclassified asunacceptable44605401 --Cleveland, C. (1998) Response to the U.S. EPA DataEvaluation Report on: Adsorption/Desorption BatchEquilibrium Partitioning of Methoxypyridine andDichloropyridinol Metabolites of Fluroxypyr: Lab ProjectNumber: GH-C 3854R. Unpublished study prepared by DowAgroSciences LLC 18 p.40244543Fluroxypyr-MHEYon, D. (1986) Determination of the Adsorption ofFluroxypyr 1 Methylheptyl Ester (MHE) onto Ditch BottomSludge: (Holland, 1985): Laboratory Project ID: GHE-P1517. Unpublished compilation prepared by Dow ChemicalCo. 15 p.50GuidelineMRIDTestMaterialCitationRemarks40244544 fluroxypyrFreeman,J."The Degradation and Leaching of Flumxypyr inSoil- U.K. 1984". Performed byDowChemicalCo.,England.Submitted by Ikw CXlanical U.S.A.Method Validation850.610044080346fluroxypyr,fluroxypyrDCP,fluroxypyr-MPMoore, M. (1996) Determination of Residues of Fluroxypyr((4-Amino-3,5-dichloro-6-fluoro-2-oxy Acetic Acid)Pyridine), Methoxypyridine ((4-Amino-3,5-dichloro-6-fluoro2-methoxy) Pyridine) and 3,5-Dichloropyridinol ((4-Amino3,5-dichloro- 6-fluoro-2-hydroxy) Pyridine) in Soil byCapillary Gas Chromatography Using Mass SelectiveDetection: Lab Project Number: GH-C 4170. Unpublishedstudy prepared by DowElanco, Global EnvironmentalChemistry Lab. 63 p.The LOQ is 0.01μg/g: however, aLOD was notreported.45824101FluroxypyrMHE,fluroxypyr,fluroxypyrDCP,fluroxypyr-MPShackelford, D. (2000) Validation Report for theDetermination of Residues of Fluroxypyr 1-methylheptylester, Fluroxypyr-acid, Fluroxypyr-2-pyridinol, andFluroxypyr-2-methoxypryidine inSurface Water by CapillaryGas Chromatography with Mass Spectrometric Detection:Lab Project Number: 001016: GRM 00.21. Unpublishedstudy prepared by Dow AgroSciences LLC.A LOD was notreported forfluroxypyr acidand itsenvironmentaltransformationproducts.44896703ECM Method Review ENVIRONMENTAL CHEM STRYMethod REVIEW REPORT NUMBER ECM0205Sl-S3Determination of Residues of Fluroxypyr,Fluroxypyr-DCP, and Fluroxypyr-MP in SoilThe method isscientificallyvalid; however, aLOD was notestablished forfluroxypyr acidand itsenvironmentaltransformationproducts. TheLOQ in soil wasdetermined to be10 μg/kg.45084601Bioconcentration850.173044605403fluroxypyr-MHEWoodburn, K. (1998) Response to the U.S. EPA DataEvaluation Report on: The Bioconcentration and Metabolismof Fluroxypyr 1-Methylheptyl Ester by the Rainbow Trout,Ocorhynchus mykiss Walbaum: Lab Project Number: ES-51GuidelineMRIDTestMaterialCitationRemarks2679S. Unpublished study prepared by The Dow ChemicalCompany. 40 p.44080348fluroxypyr-MHERick, D.; Kirk, H.; Fontaine, D.; et al. (1996) TheBioconcentration and Metabolism of Fluroxypyr 1-Methylheptyl Ester by the Rainbow Trout, Oncorhynchusmykiss Walbaum: Lab Project Number: DECO-ES-2679.Unpublished study prepared by The Toxicology ResearchLab., The Dow Chemical Co. 90 p.Storage Stability40244540fluroxypyr-MHEHawkins, D.; Kirkpatrick, D.; Conway, B.; et al. (1982) TheMetabolism of [Carbon 14]-Dowco 433 MHE in Laboratorystored Soil: Laboratory Project ID: DWC 312/341 8240.Unpublished study pre- pared by Huntingdon ResearchCentre. 144 p44080355fluroxypyr-MHEPhillips, A.; Blakeslee, B. (1996) Frozen Storage StabilityStudy of Fluroxypyr 1-Methylheptyl Ester, Fluroxypyr, 4-Amino-3,5-dichloro-6-fluoro-Pyridinol and 4-Amino-3,5-dichloro- 6-fluoro-Methoxypyridine in Soil: Lab ProjectNumber: RES93010/RES93051. Unpublished study preparedby Dow Elanco. 112 p.Non-guideline;Compost Study45833601fluroxypyr-MHEBrinton, W.; Evans, E. (2002)Herbicide Content Changes inBench-Scale Compost Made with Fluroxypyr and DicambaTreated Grass Clippings: Lab Project Number: PROJECT633. Unpublished study prepared by Woods End ResearchLaboratory. 13 p.52Table A.2. Ecotoxicology Studies Submitted for Fluroxypyr-MHE and Fluroxypyr AcidGuidelineMRIDTest MaterialCitationAvian Acute OralToxicity850.210040244546 Fluroxypyr-MHERoberts, N.; Phillips, C. (1984) TheAcute Oral Toxicity (LD50) ofDowco 433 Ester to the Bobwhite Quail: Laboratory Project ID:DWC 398a/84178. Unpublished study prepared by Huntingdon Research Centre. 16 p.40244516 Fluroxypyr-MHERoberts, N.L and C.N.K. Phillips.198b. The acute oral toxicity(LD50) ofDOWCO433 to the mallard buck. Conducted byHuntingdon Research Centre plc, Huntingdon, Cambridgeshire,England. Submitted by Dow Chemical Europe, Research andDevelopment, Bachtobelstrasse3, 8810 Horgen, Switzerland.40244514 Fluroxypyr acidRoberts, N.; Phillips, C. (1984) TheAcute Oral Toxicity (LD50) ofDowco 433 Acid to the Mallard Duck: Laboratory Project ID:DWC 397/84158. Unpublished study prepared by HuntingdonResearch Centre. 15 p.40244515 Fluroxypyr acidRoberts, N.; Phillips, C. (1984) TheAcute Oral Toxicity (LD50) ofDowco 433 Acid to the Bobwhite Quail: Laboratory Project ID:DWC 398b/84233. Unpublished study prepared by HuntingdonResearch Centre. 17 p.Avian DietaryToxicity850.220040244517 Fluroxypyr-MHERoberts, N.; Phillips, C. (1983) The Subacute Dietary Toxicity (LC50) of Dowco 433 Ester to the Bobwhite Quail: Laboratory ProjectID: DWC 393B/83903. Unpublished study prepared by HuntingdonResearch Centre. 20 p.42137301 Fluroxypyr-MHEGrimes, J., and M. Jaber. 1988. Fluroxypyr, 1-methyheptyl ester: ADietary LC50 Study with the Mallard. Project No. 103-286.Performed by Wildlife International, Ltd., Easton, MD. Submittedby Dow Chemical Company, Midland, MI.40244547 Fluroxypyr acidRoberts, N.; Phillips, C. (1983)The Subacute Dietary Toxicity(LC50) of Dowco 433 Acid to the Bobwhite Quail: LaboratoryProject ID: DWC 393A/83902. Unpublished study prepared byHuntingdon Research Centre. 20 p.42137302 Fluroxypyr acidGrimes, J.; Lynn, S.; Smith, G. (1991) Fluroxypyr: A Dietary LC50Study with the Mallard: Lab Project Number: ES/DR/0170/8550/5.Unpublished study prepared by Wildlife International Ltd. 21 p.Avian ReproductionTest850.230040244517 Fluroxypyr-MHERoberts, N.; Phillips, C. (1983) The Subacute Dietary Toxicity (LC50) of Dowco 433 Ester to the Bobwhite Quail: Laboratory ProjectID: DWC 393B/83903. Unpublished study prepared by HuntingdonResearch Centre. 20 p.53GuidelineMRIDTest MaterialCitation42137301 Fluroxypyr-MHEGrimes, J., and M. Jaber. 1988. Fluroxypyr, 1-methyheptyl ester: ADietary LC50 Study with the Mallard. Project No. 103-286.Performed by Wildlife International, Ltd., Easton, MD. Submittedby Dow Chemical Company, Midland, MI.42137303 Fluroxypyr acidBeavers, J.; Hawrot, R.; Jaber, M. (1989) Fluroxypyr 1-Methylheptyl Ester Herbicide: A One-Generation Study with theBobwhite (Colinus virginianus): Lab Project Number: ES-DR0186-1887-14: 103-295. Unpublished study prepared by WildlifeInternational Ltd. 116 p.42137304 Fluroxypyr acidBeavers, J.; Hoxter, K.; Nichols, L.; et al. (1989) Fluroxypyr 1-Methylheptyl Ester Herbicide: A One-Generation ReproductionStudy with the Mallard (Anas platyrhynchos): Lab Project Number:ES-DR-0186-1887-15: 103/296. Unpublished study prepared byWildlife International Ltd. 118 p.Fish Acute Toxicity(Freshwater)850.107540244519 Fluroxypyr-MHEWillis, C. (1984) The Acute Toxicity of Dowco 433 Acid to GoldenOrfe: Amended Report: LSR/Aquatox Schedule No. AFT/84/012.Un- published study prepared by Aquatox Limited. 24 p.40244522 Fluroxypyr-MHEWillis, C. (1984) The Acute Toxicity of Dowco 433 Ester toRainbow Trout: LSR/Aquatox Schedule No. AFT/84/013.Unpublished study prepared by Aquatox Limited. 33 p.40244523 Fluroxypyr-MHEWillis, C. (1984) The Acute Toxicity of Dowco 433 Ester toGolden Orfe: LSR/Aquatox Schedule No. AFT/84/015.Unpublished study prepared by Aquatox Limited. 41 p.44080307 Fluroxypyr-MHERick, D.; Landre, A.; Kirk, H. (1996) Evaluation of the AcuteToxicity of Fluroxypyr 1-Methylheptyl Ester to the Bluegill,Lepomis macrochirus Rafinesque: Lab Project Number: DECO-ES3020. Unpublished study prepared by The EnvironmentalToxicology Research Lab., the Dow Chemical Co. 53 p.44080307 Fluroxypyr-MHEBoeri, R.; Kowalski, P.; Ward, T. (1996) Fluroxypyr 1-Methylheptyl Ester: Acute Toxicity to the Sheepshead Minnow,Cyprinodon variegatus: Lab Project Number: DECO-ES-2961:707-DO. Unpublished study prepared by T. R. Wilbury Labs., Inc.24 p.40244525 Fluroxypyr-MHEHill, R.W. 1984. EF689: Determination of the Acute Toxicity toRainbow Trout (Salmo gairdneri). Laboratory Study NumberM083/A. Prepared by Imperial Chemical Industries PLC , Brixham,Devon, England. Submitted by Agricultural Products Department,Dow Chemical U. S .A. MRID Number 402443 -25.54GuidelineMRIDTest MaterialCitation42137305 Fluroxypyr-MHEDill, D.C. and E.A. Bartlett.1989. Fluroxypyr 1-MethylheptylEster: Evaluation of the Toxicity to the Bluegill, Lepomismacrochirus Rafinesque. Laboratory project Study ID. ES-DR0186-1887-3. Prepared by Mammalian& Environmental Toxicology Research Laboratory, The DowChemical Company, Midland, MI. Submitted by Dow Elanco. EPAMRID No. 421373-05.42137307 Fluroxypyr-MHEWeinberg, J.; Richardson, C.; Rick, D.; et al. (1991) Fluroxypyr, 1-Methylheptyl Ester: Evaluation of the Acute Toxicity to theRainbow Trout, Oncorhynchus mykiss Walbaum: Lab ProjectNumber: ES-DR-0186-1887-18. Unpublished study prepared byDow Chemical Co., Environ. Tox.& Chem. Research Lab. 25 p.40244518 Fluroxypyr acidWillis, C. (1984) The Acute Toxicity of Dowco 433 Acid toRainbow Trout: LSR/Aquatox Schedule No. AFT/84/008.Unpublished study prepared by Aquatox Limited. 19 p.40244519 Fluroxypyr acidWillis, C.A. 1984. The Acute Toxicity of DOWCO 433 Acid toGolden Orfe. Laboratory Project ID: LSR/~tox Schedule No.AFT/84/012. Prepared byAquatox Limited, Suffolk, England.Submitted by Agricultural Products Department, Dow Chemical U.S .A. Accession 402445-19.42137306 Fluroxypyr acidWeinberg, J.; Richardson, C.; Rick, D.; et al. (1991) Fluroxypyr:Evaluation of the Acute Toxicity to the Bluegill, Lepomismacroochirus Rafinesque: Lab Project Number: ES-DR-0170-8550-7. Un- published study prepared by Dow Chemical Co.,Environ. Tox. and Chem. Research Lab. 26 p.Fish Acute Toxicity(Saltwater)850.1075 44080308 Fluroxypyr-MHEBoeri, R.; Kowalski, P.; Ward, T. (1996) Fluroxypyr 1-Methylheptyl Ester: Acute Toxicity to the Sheepshead Minnow,Cyprinodon variegatus: Lab Project Number: DECO-ES-2961:707-DO. Unpublished study prepared by T. R. Wilbury Labs., Inc.24 p.42137309 Fluroxypyr-MHEManning, C. (1988) Fluroxypyr 1-MHE: Acute Toxicity to AtlanticSilversides (Menidia menidia) Under Flow-through Conditions:Lab Project Number: 87388-0200-2130: ES-DR-0186-1887-6.Unpublished study prepared by Environmental Science andEngineering, Inc. 30 p.Aquatic InvertebrateAcute Toxicity,Daphnids40244520 Fluroxypyr-MHEJones, N. 1984. The Acute Toxicity of DOWCO433 EstertoDaphnia magna. Laboratory Project ID: LSR/Aquatox ScheduleNo. AFT/84/014. Prepared byAquatox Limited, Suffolk, England.55GuidelineMRIDTest MaterialCitation850.1010 SubmittedbyAgricultural Products Department, Dow Chemical,U.S.A. Accession Number 402445-20.42137308 Fluroxypyr-MHEWeinberg, J.; Milazzo, D.; Servinski, M.; et al. (1991) Fluroxypyr,1-Methylheptyl Ester: Evaluation of the Acute Toxicity to theWater Flea, Daphnia magna Straus: Lab Project Number: ES-DR01- 86-1887-19. Unpublished study prepared by Dow ChemicalCo., Environ. Tox. & Chem. Research Lab. 26 p.40244524 Fluroxypyr acidJones, N. (1984) The Acute Toxicity of Dowco 433 Acid toDaphnia magna: LSR/Aquatox Schedule No. AFT/84/009.Unpublished study prepared by Aquatox Limited. 22 p.Prolong Toxicitywith Daphnia magna(nonguideline)40244521 Fluroxypyr acidJones, N. (1984) Prolonged Toxicity of Dowco 433 Acid toDaphnia magna: LSR/Aquatox Schedule No. AFT/84/010.Unpublished study prepared by Aquatox Limited. 38 p.Penaeid (Shrimp)Acute Toxicity850.1045 44080313 Fluroxypyr-MHEBoeri, R.; Kowalski, P.; Ward, T. (1996) Fluroxypyr 1-Methylheptyl Ester: Acute Toxicity to the Grass Shrimp,Palaemonetes pugio: Lab Project Number: 706-DO: DECO-ES2962: Unpublished study prepared by T. R. Wilbury Labs., Inc. 24p.42137311 Fluroxypyr-MHEManning, C. (1988) Fluroxypyr 1-MHE: Acute Toxicity to PinkShrimp (Penaeus duorarum) Under Flow-through Conditions: LabProject No: 87388-0300-2130. Unpublished study prepared byEnvironmental Science and Engineering, Inc. 31 p.42137312 Fluroxypyr acidBoeri, R.; Kowalski, P.; Ward, T. (1994) Fluroxypyr: AcuteToxicity to the Grass Shrimp, Palaemonetes pugio: Lab ProjectNumber: 197-DO: ES-2643. Unpublished study prepared by T. R.Wilbury Labs., Inc. 24 p.Oyster AcuteToxicity(Shell Deposition)850.102544080310 Fluroxypyr-MHEBoeri, R.; Kowalski, P.; Ward, T. (1996) Fluroxypyr 1-Methylheptyl Ester: Acute Flow-Through Mollusc Shell DepositionTest: Lab Project Number: 646-DO: DECO-ES-2925. Unpublishedstudy prepared by T. R. Wilbury Labs., Inc. 28 p.45725801 Fluroxypyr-MHEDionne, E. (2002) Fluroxypyr 1-Methylheptyl ester--AcuteToxicity to Eastern Oysters (Crassostrea virginica) Under FlowThrough Conditions: Lab Project Number: 12550.6202: 021015.Unpublished study prepared by Springborn Smithers Laboratories.60 p.42137310 Fluroxypyr-MHEManning, C. (1988) Fluroxypyr 1-MHE: Shell Growth of theEastern Oyster (Crassostrea virginica): Lab Project No: 87388-56GuidelineMRIDTest MaterialCitation0400-2130. Unpublished study prepared by Environmental Scienceand Engineering, Inc. 31 p.42137311 Fluroxypyr acidBoeri, R.; Kowalski, P.; Ward, T. (1994) Fluroxypyr: Acute FlowThrough Mollusc Shell Deposition Test: Lab Project Number: 198-DO: ES-2645. Unpublished study prepared by T. R. Wilbury Labs.,Inc. 25 p.Daphnid Life CycleToxicity850.1300 44080314 Fluroxypyr-MHEKirk, H.; Miller, J.; Hugo, J.; et al. (1996) Evaluation of theChronic Toxicity of Fluroxypyr 1-Methylheptyl Ester to theDaphnid, Daphnia magna Straus: Lab Project Number: DECO-ES3079: 19023. Unpublished study prepared by The Dow ChemicalCo. 78 p.Fish Early-LifeStage Toxicity850.1400 48559401 Fluroxypyr acidGallagher, S.; Kendall, T.; Krueger, H. (2011) Fluroxypyr: AnEarly Life-Stage Toxicity Test with the Fathead Minnow(Pimephales promelas): Final Report. Project Number: 101728379A/147A. Unpublished study prepared by Wildlife International,Ltd. 97p.Honey Bee AcuteContact Toxicity850.302040244527 Fluroxypyr-MHECole, J. (1983) The Acute Contact and Oral Toxicity to Honey Beesof Technical Dowco 433--MH Ester: Laboratory Project ID: DWC387/83717/2. Unpublished study prepared by Huntingdon ResearchCentre. 9 p.42137313 Fluroxypyr-MHELynn, S.; Hoxter, K. (1991) Fluroxypyr, 1-MHE: An Acute ContactToxicity Study with the Honey Bee: Lab Project No: ES-DR-0186-1887-17. Unpublished study prepared by Wildlife InternationalLab. 18 p.42137314 Fluroxypyr acidLynn, S.; Hoxter, K. (1991) Fluroxypyr: An Acute Contact ToxicityStudy with the Honey Bee: Lab Project Number: ES-DR-0170-8550-4: 103-358. Unpublished study prepared by WildlifeInternational Ltd. 18 p.Seedling Emergence850.410044080335 Fluroxypyr-MHESchwab, D. (1996) Evaluating the Effects of Fluroxypyr-MHE onthe Seedling Emergence and Vegetative Vigor of Non-TargetTerrestrial Plants: Lab Project Number: 42838: RES95175.Unpublished study prepared by ABC Labs., Inc. 168 p.44094902 Fluroxypyr-MHEWright, J.; Rowland, L. (1996) Phytotoxicity of Fluroxypyr MHEand Its Metabolites Fluroxypyr, Methoxypyridine, and Pyridinol toNon-Target Terrestrial Plants: Amended Report: Lab ProjectNumber: GH-C 3859. Unpublished study prepared by DowElancoGlobal Environmental Chemistry Lab. 201 p.57GuidelineMRIDTest MaterialCitationVegetative Vigor850.415044080335 Fluroxypyr-MHESchwab, D. (1996) Evaluating the Effects of Fluroxypyr-MHE onthe Seedling Emergence and Vegetative Vigor of Non-TargetTerrestrial Plants: Lab Project Number: 42838: RES95175.Unpublished study prepared by ABC Labs., Inc. 168 p.44094902 Fluroxypyr-MHEWright, J.; Rowland, L. (1996) Phytotoxicity of Fluroxypyr MHEand Its Metabolites Fluroxypyr, Methoxypyridine, and Pyridinol toNon-Target Terrestrial Plants: Amended Report: Lab ProjectNumber: GH-C 3859. Unpublished study prepared by DowElancoGlobal Environmental Chemistry Lab. 201 p.Aquatic PlantToxicity UsingLemnasp.850.440044080338 Fluroxypyr-MHEKirk, H.; Milazzo, D.; Hugo, J.;et al. (1996) Fluroxypyr 1-Methylheptyl Ester: The Toxicity to the Aquatic Plant, Duckweed,Lemna gibba L. G-3: Lab Project Number: DECO-ES-3074: 19023.Unpublished study prepared by The Dow Chemical Co. 61 p.44744001Fluroxypyr-MHE(as Starane 180)Kirk, H.; Gilles, M.; Rick, D. et al. (1998) PhytotoxicologicalEvaluation of Starane 180 Emulsifiable Herbicide Concentrate(Formulation EF-1463) Exposed Aquatic Plant, Duckweed, Lemnagibba L. G-3: Lab Project Number: 981132. Unpublished studyprepared by Dow Chemical Company. 75 p.Algal Toxicity850.540044080337 Fluroxypyr-MHEHughes, J.; Alexander, M.; Conder, L. (1996) Fluroxypyr 1-Methylheptyl Ester: The Toxicityto Skeletonema costatum: LabProject Number: 10-04-1. Unpublished study prepared by CarolinaEcotox, Inc. 86 p.44080339 Fluroxypyr-MHEMilazzo, D.; Landre, A.; Hugo, J.; et al. (1996) Fluroxypyr 1-Methylheptyl Ester: The Toxicity to the Freshwater Diatom,Navicula pelliculosa: Lab Project Number: ES-3075: 19023:DECO-ES-3075. Unpublished study prepared by The DowChemical Co. 56 p.44527201 Fluroxypyr-MHEKirk, H.; Landre, A.; Hugo, J. etal. (1998) Supplemental Reportfor: Fluroxypyr 1-Methylheptyl Ester: The Toxicity to theFreshwater Diatom, Navicula pelliculosa: Lab Project Number: ES3075. Unpublished study prepared by The Dow Chemical Co. 44 p.44527201 Fluroxypyr-MHEMilazzo, D.; Hugo, J.; Martin, M. (1996) Fluroxypyr 1-Methylheptyl Ester: The Toxicity to the Freshwater Green Alga,Selenastrum capricornutum Printz: Lab Project Number: ES-3076:19023: DECO-ES-3076. Unpublished study prepared by The DowChemical Co. 53 p.45820801 Fluroxypyr-MHEHoberg, J. (2002) Fluroxypyr 1-Methylheptyl Ester Technical--Acute Toxicity to the FreshwaterDiatom (Navicula pelliculosa):58GuidelineMRIDTest MaterialCitationLab Project Number: 12550.6203: 021014. Unpublished studyprepared by Springborn Smithers Laboratories. 68 p.42137312 Fluroxypyr-MHEHughes, J.; Alexander, M. (1991) The Toxicity of Fluroxypyr 1-Methylheptyl Ester to Selenastrum capricornutum: Lab Project No:B460-12-1: ES-DR-0186-1887-16. Unpublished study prepared byMalcolm Pirnie, Inc. 37 p.42164501 Fluroxypyr-MHECowgill, U.; Milazzo, D.; Murphy, P. (1988) The Five-DayToxicity Of Fluoroxypyr (Dowco 433) to SelenastrumCapricornutum Printz, a Freshwater Green Alga: Lab ProjectNumber: ES-DR-0170-8550-3: ES-1016. Unpublished studyprepared by The Dow Chemical Co. 19 p.40244526 Fluroxypyr acidJones, N. (1984) Toxicity of Dowco 433 Acid to Chlorella vulgaris,CCAP 211/11b: LSR/Aquatox Schedule No. AFT/84/011.Unpublished study prepared by Aquatox Limited. 31 p.440803414-Amino-3,5-Dichloro-6-Fluoro-2-MethoxypyridineKirk, H.; Landre, A. (1995) Evaluation of the Phytotoxicity of 4-Amino-3,5-Dichloro-6-Fluoro-2-Methoxypyridine to the GreenAlgae, Selenastrum capricornutum Printz: Lab Project Number:DECO-ES-3029. Unpublished study prepared by The DowChemical Co. 15 p.450116014-Amino-3,5-dichloro-6-fluoro-2-pyridinolWard, T.; Magazu, J.; Boeri, R. (1999) 4-Amino-3,5-dichloro-6-fluoro-2-pyridinol (A Metabolite of Fluroxypyr): Toxicity to theFreshwater Diatom, Navicula pelliculosa: Lab Project Number:990032: 1728-DO. Unpublished study prepared by T.R. WilburyLabs., Inc. 26 p.450116024-Amino-3,5-dichloro-6-fluoro-2-pyridinolWard, T.; Magazu, J.; Boeri, R. (1999) 4-Amino-3,5-dichloro-6-fluoro-2-pyridinol (A Metabolite of Fluroxypyr): Toxicity to theDuckweed, Lemna gibba: Lab Project Number: 990033: 1731-DO.Unpublished study prepared by T.R. Wilbury Labs., Inc. 26 p.450116034-Amino-3,5-dichloro-6-fluoro-2-pyridinolWard, T.; Magazu, J.; Boeri, R. (1999) 4-Amino-3,5-dichloro-6-fluoro-2-pyridinol (A Metabolite of Fluroxypyr): Toxicity to theGreen Alga, Selenastrum capricornutum: Lab Project Number:990034: 1732-DO. Unpublished study prepared by T.R. WilburyLabs., Inc. 26 p.450116044-Amino-3,5-dichloro-6-fluoro-2-pyridinolWard, T.; Magazu, J.; Boeri, R. (1999) 4-Amino-3,5-dichloro-6-fluoro-2-pyridinol (A Metabolite of Fluroxypyr): Toxicity to theFreshwater Bluegreen Alga, Anabaena flos-aquae: Lab ProjectNumber: 990035: 1729-DO. Unpublished study prepared by T.R.Wilbury Labs., Inc. 26 p.59GuidelineMRIDTest MaterialCitation450116054-Amino-3,5-dichloro-6-fluoro-2-pyridinolWard, T.; Magazu, J.; Boeri, R. (1999) 4-Amino-3,5-dichloro-6-fluoro-2-pyridinol (A Metabolite of Fluroxypyr): Toxicity to theSaltwater Diatom, Skeletonemacostatum: Lab Project Number:990036: 1730-D0. Unpublished study prepared by T.R. WilburyLabs., Inc. 26 p.450116064-Amino-3,5-dichloro-6-fluoro-2-methoxypyridineWard, T.; Magazu, J.; Boeri, R. (1999) 4-Amino-3,5-dichloro-6-fluoro-2-methoxypyridine (A Metabolite of Fluroxypyr): Toxicityto the Freshwater Diatom, Navicula pelliculosa: Lab ProjectNumber: 990037: 1733-DO. Unpublished study prepared by T.R.Wilbury Labs., Inc. 36 p.450116074-Amino-3,5-dichloro-6-fluoro-2-methoxypyridineWard, T.; Magazu, J.; Boeri, R. (1999) 4-Amino-3,5-dichloro-6-fluoro-2-methoxypyridine (A Metabolite of Fluroxypyr): Toxicityto the Duckweed, Lemna gibba:Lab Project Number: 990038:1736-DO. Unpublished study prepared by T.R. Wilbury Labs., Inc.36 p.450116084-Amino-3,5-dichloro-6-fluoro-2-methoxypyridineWard, T.; Magazu, J.; Boeri, R. (1999) 4-Amino-3,5-dichloro-6-fluoro-2-methoxypyridine (A Metabolite of Fluroxypyr): Toxicityto the Freshwater Bluegreen Alga, Anabaena flos-aquae: LabProject Number: 90039: 1734-DO. Unpublished study prepared byT.R. Wilbury Labs., Inc. 26 p.450116094-Amino-3,5-dichloro-6-fluoro-2-methoxypyridineWard, T.; Magazu, J.; Boeri, R. (1999) 4-Amino-3,5-dichloro-6-fluoro-2-methoxypyridine (A Metabolite of Fluroxypyr): Toxicityto the Saltwater Diatom, Skeletonema costatum: Lab ProjectNumber: 990040: 1735-DO. Unpublished study prepared by T.R.Wilbury Labs., Inc. 26 p.CyanobacteriaToxicity850.4550 44080336 Fluroxypyr-MHEMilazzo, D.; Miller, J.; Hugo, J.; et al. (1996) Fluroxypyr 1-Methylheptyl Ester: The Toxicity to the Blue-Green Alga,Anabaena flos-aquae: Lab Project Number: ES-3073: 19023:DECO-ES-3073. Unpublished study prepared by The DowChemical Co. 55 p.

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## APPENDIX B. INPUTS AND OUTPUTS FROM THE SIP AND STIR MODELS

I. Screening Imbibition Program (SIP), Version 1.0 A. Fluroxypyr
Table 1. Inputs

Parameter Value

Chemical name Fluroxypyr
Solubility (in water at 25 o C; mg/L) 255.03

Mammalian LD 50 (mg/kg-bw) 2408 Mammalian test species laboratory rat Body weight (g) of "other" mammalian species

Mammalian NOAEL (mg/kg-bw) 500 Mammalian test species laboratory rat Body weight (g) of "other" mammalian species

Avian LD 50 (mg/kg-bw) 2000 Avian test species northern bobwhite quail Body weight (g) of "other" avian species Mineau scaling factor 1.15

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

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Table 2. Mammalian Results

Parameter Acute Chronic Upper bound exposure (mg/kg-bw) 43.8652 43.8652 Adjusted toxicity value (mg/kg-bw) 1852.1386 384.5803 Ratio of exposure to toxicity 0.0237 0.1141

Conclusion* Drinking water exposure alone is NOT a potential

concern for mammals Drinking water exposure alone is NOT a potential

concern for mammals

Table 3. Avian Results

Parameter Acute Chronic Upper bound exposure (mg/kg-bw) 206.5743 206.5743 Adjusted toxicity value (mg/kg-bw) 1440.8590 0.0000 Ratio of exposure to acute toxicity 0.1434 0.0000

Conclusion* Exposure through drinking water alone is a

potential concern for

birds Due to insufficient data, risk cannot be precluded

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



### B. Fluroxypyr-MHE
Table 1. Inputs

Parameter Value

Chemical name Fluroxypyr-MHE
Solubility (in water at 25 o C; mg/L) 0.9

Mammalian LD 50 (mg/kg-bw) 809 Mammalian test species laboratory rat Body weight (g) of "other" mammalian species

Mammalian NOAEL (mg/kg-bw) 300 Mammalian test species laboratory rat Body weight (g) of "other" mammalian species

Avian LD 50 (mg/kg-bw) 2000 Avian test species northern bobwhite quail Body weight (g) of "other" avian species Mineau scaling factor 1.15

Mallard NOAEC (mg/kg-diet) 250 Bobwhite quail NOAEC (mg/kg-diet) 1000 NOAEC (mg/kg-diet) for other bird species Body weight (g) of other avian species

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NOAEC (mg/kg-diet) for 2nd other bird species Body weight (g) of 2nd other avian species

Table 2. Mammalian Results

Parameter Acute Chronic Upper bound exposure (mg/kg-bw) 0.1548 0.1548 Adjusted toxicity value (mg/kg-bw) 622.2509 230.7482 Ratio of exposure to toxicity 0.0002 0.0007

Conclusion* Drinking water exposure alone is NOT a potential

concern for mammals Drinking water exposure alone is NOT a potential

concern for mammals

Table 3. Avian Results

Parameter Acute Chronic Upper bound exposure (mg/kg-bw) 0.7290 0.7290 Adjusted toxicity value (mg/kg-bw) 1440.8590 12.4031 Ratio of exposure to acute toxicity 0.0005 0.0588

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

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



### II. Screening Tool for Inhala tion Risk (STIR), Version 1.0 A. Fluroxypyr



# Input

Application and Chem ical Information

Enter Chemical Name Fluroxypyr

Enter Chemical Use grains Is the Application a Spray? (enter y or n) y If Spray What Type (enter ground or air) air Enter Chemical Molecular Weight (g/mole) 255.03 Enter Chemical Vapor Pressure (mmHg) 9.50E-11 Enter Application Rate (lb a.i./acre) 0.225

Toxicity Properties

Bird

Enter Lowest Bird Oral LD 50 (mg/kg bw) 2000 Enter Mineau Scaling Factor 1.15 Enter Tested Bird Weight (kg) 0.178

Mammal

Enter Lowest Rat Oral LD 50 (mg/kg bw) 2408

Enter Lowest Rat Inhalation LC 50 (mg/L) 2.09 Duration of Rat Inhalation Study (hrs) 4

### 63

Enter Rat Weight (kg) 0.35



# Output

Results Avian (0.020 kg )
Maximum Vapor Concentration in Air at Saturation (mg/m 3 ) 1.30E-06 Maximum 1-hour Vapor Inhalation Dose (mg/kg) 1.64E-07

Adjusted Inhalation LD 50 9.68E+00

Ratio of Vapor Dose to Adjusted Inhalation LD 50 1.69E-08 Exposure not Likely Significant Maximum Post-treatment Spray Inhalation Dose (mg/kg) 2.16E-02 Ratio of Droplet Inhalation Dose to Adjusted Inhalation

LD 50 2.23E-03 Exposure not Likely Significant



### Results Mammalian (0.015 kg )
Maximum Vapor Concentration in Air at Saturation (mg/m 3 ) 1.30E-06 Maximum 1-hour Vapor Inhalation Dose (mg/kg) 2.06E-07

Adjusted Inhalation LD 50 1.24E+02

Ratio of Vapor Dose to Adjusted Inhalation LD 50 1.66E-09 Exposure not Likely Significant Maximum Post-treatment Spray Inhalation Dose (mg/kg) 2.72E-02 Ratio of Droplet Inhalation Dose to Adjusted Inhalation

LD 50 2.18E-04 Exposure not Likely Significant

### 64

B. Fluroxypyr-MHE



# Input

Application and Chem ical Information

Enter Chemical Name Fluroxypyr-MHE

Enter Chemical Use Pastures Is the Application a Spray? (enter y or n) y If Spray What Type (enter ground or air) air Enter Chemical Molecular Weight (g/mole) 367.24 Enter Chemical Vapor Pressure (mmHg) 1.07E-07 Enter Application Rate (lb a.i./acre) 0.76

Toxicity Properties

Bird

Enter Lowest Bird Oral LD 50 (mg/kg bw) 2000 Enter Mineau Scaling Factor 1.15 Enter Tested Bird Weight (kg) 0.178

Mammal

Enter Lowest Rat Oral LD 50 (mg/kg bw) 809

Enter Lowest Rat Inhalation LC 50 (mg/L) 2.09 Duration of Rat Inhalation Study (hrs) 4 Enter Rat Weight (kg) 0.35



# Output

Results Avian (0.020 kg )
Maximum Vapor Concentration in Air at Saturation (mg/m 3 ) 2.11E-03 Maximum 1-hour Vapor Inhalation Dose (mg/kg) 2.66E-04

Adjusted Inhalation LD 50 2.88E+01

Ratio of Vapor Dose to Adjusted Inhalation LD 50 9.23E-06 Exposure not Likely Significant Maximum Post-treatment Spray Inhalation Dose (mg/kg) 7.30E-02 Ratio of Droplet Inhalation Dose to Adjusted Inhalation

LD 50 2.53E-03 Exposure not Likely Significant



### Results Mammalian (0.015 kg )
Maximum Vapor Concentration in Air at Saturation (mg/m 3 ) 2.11E-03 Maximum 1-hour Vapor Inhalation Dose (mg/kg) 3.34E-04

Adjusted Inhalation LD 50 1.24E+02

Ratio of Vapor Dose to Adjusted Inhalation LD 50 2.69E-06 Exposure not Likely Significant Maximum Post-treatment Spray Inhalation Dose (mg/kg) 9.18E-02 Ratio of Droplet Inhalation Dose to Adjusted Inhalation

LD 50 7.38E-04 Exposure not Likely Significant