OFFICE OF
CHEMICAL SAFETY AND
POLLUTION PREVENTION UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON D.C., 20460



### PC Code: 041101

DP Barcode : D 410027

MEMORANDUM September 18

, 201 5

Subject: Environmental Fate and Ecological Risk Assessment for the R e gistration

Review of Ethoprop

To: Eric Miederhoff, Chemical Review Manager Tracy Perry, Team Leader Kelly Sherman , Branch Chief Risk Management and Implementation Branch III

Pesticide Re

- Evaluation Division (7508P)

From: Geoffrey Sinclair, Ph.D., Biologist

Michael Barrett

, Chemist

Environmental Risk Branch V Environmental Fate and Effects Division (7507P)

Reviewed By: Justin Housenger

, Biologist

Jose Melendez

, Chemist

Environmental Risk Branch V Environmental Fate and Effects Division (7507P)

Through: Mah Shamim, Ph.D., Branch Chief

Environmental Risk Branch V Environmental Fate and Effects Division (7507P)

This memorandum transmits the Environ mental Fate and Effects Division’ s (EFED) registration

review ecological risk assessment for the organophosphate nematicide/insecti ci de e thoprop (PC

Code 041101 , also known as ethoprophos; chemical name O

- ethyl

- S,S

- dipropyl phosphorodithioate ) . The end us e products include water dispersible granule and emulsified concentration formulations for ground application to soil and immediate incorporation. Application rates range from 1.95 to 12 pounds active ingredient per acre ( lbs a.i./A ) on uses such as cucur bits, hops, nursery stock, sugar beets, sweet potato, sugarcane, cabbage, corn, mint,

### 2 tobacco, succulent (lima) beans, potatoes east of the Mississippi, and potatoes west of the Mississippi

. The conclusions of this assessment remain largely unchanged fro m previous

assessments. When estimates of ethoprop exposure in terrestrial and aquatic environments are compared to the available ecotoxicity data, the results of the screening

- level assessment indicate a potential fo r acute and chronic risk above the leve l of concern (LOC) to both aquatic and

terrestrial taxa.

Ethoprop can persist in the environment for months after application and is highly to very highly toxic to aquatic invertebrates and fish and birds and mammals and moderately toxic to honey

bees

. Environmental fate modeling and risk quotient determination indicate potential adverse effects on aquatic animal taxa. Acute and chronic risk to freshwater fish, estuarine/marine fish,
freshwater invertebrates, and estuarine/marine invertebrates, and b oth freshwater and

estuarine /marine sediment invertebrates was identified. Risk was not identified for aquatic plants based on one available diatom study. LD 50 

### /ft 2 

### analysis indicated that there is acute risk to both birds and mammals from granular formul ations. There was also acute dose based and sub

acute dietary based risk as well as chronic dietary risk to birds associated from all emulsifiable
concentrate ( EC ) applications. Similar l y, there was acute and chronic dose based risk as well as

chronic di etary based risk to mammals from all EC applications. Other indirect routes of exposure may include consumption of contaminated earthworms in treated fields. Based on estimated EECs of ethoprop in earthworm tissues and acute and chronic endpoints for bot h bird species tested , there is potential for avian risk from dietary exposure to earthworms . Ethoprop is moderately volatile ( vapor p ressure : 3.5 x 10

- 4 

### mm to 8.3 x 10

- 4 

### mm Hg at 25

- 26 o 

### C; Henry’s law

constant value about 1.3 E

- 8 

### atm.m3/mole) but modeling suggests that inhalation i s not a risk to

either birds or mammals. While ethoprop is applied by boom sprayer the coarse droplet size specified on current labels reduce risk to terrestrial taxa through spray drift. Consistent with ethoprop’s mode of action as an insecticide, Bee

- REX modeling predicted risk to bees if exposed to residues of ethoprop. Results of past assessments and current application practices are designed to limit exposure but exposure f rom residues on plants remaining in t he field or from spray drift is possible and would present a risk to pollinators and other beneficial insects.

Data gaps for this chemical include acute and chronic toxicity studies for larval bees and chronic feeding studies for adult bees, as well as sed iment chronic toxicity tests. In the absence of this

data

, risk is presumed in these compartments as well. Data are also limited in terms of the aerobic soil and anaerobic aquatic metabolism of ethoprop (OCSPP guideline 835.4100 and 835.4400 studies): th e 835.4100 study is available in only one test soil (current guidance now generally requires at least 4 test soils) and no study is a vailable to meet the 835.4400 guideline (previously waived, but the lack of which appears now to be a significant source of uncertainty regarding the environmental fate of ethoprop)

.

### 3 `

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON, D.C. 20460

OFFICE OF CHEMICAL SAFETY

AND POLLUTION PREVENTION



# Preliminary Environmental Fate and Ecological Risk

Assessment for the Registration Review of Ethoprop (Ethoprophos)



# O

P O S S C H 2 

# C H 3



# C H 2 

# H 2 

# C C H 3 

# H 2 

# C H 3 

# C H 2 

# C

CAS 13194

- 48

- 4

PC Code 041101

DP Barcode 410027



### July 7
, 2015

Prepared b y Michael R. Barre t t , Chemist Geoffrey Sinclair, Ph.D.

, Biologist U.S. Environmental Protection Agency Office of Pesticide Programs

Environmental Fate and Effects Division

Environmental Risk Branch V 1200 Pennsylvania Ave., NW

Mail Code 7507P Washington, DC 20460 

### Reviewed by Justin Housenger

, Biologist

Jose Melendez

, Chemist

Mah T. Shamim

, Ph.D., Branch Chief

### 4 

# Table of Contents

Executive Summary

................................ ................................ ................................ ................................ ..................... 7 Purpose of Assessment

................................ ................................ ................................ ................................ ............ 7 Summary of Relevant Environmental Fate, Transport, and Exposure Pathways

................................ ............ 7 Summary of Effects and Risk Conclusions

................................ ................................ ................................ ........... 7

Introduction

................................ ................................ ................................ ................................ ................................ . 9

Pesticid e Use Characterization

................................ ................................ ................................ ................................ . 10 Drift / Exposure Reduction Label Language

................................ ................................ ................................ ...... 11 Method and Rates of Application:

................................ ................................ ................................ ....................... 11 Specific Label Directions by Crop

................................ ................................ ................................ ....................... 12 Fate and Exposure Characterization

................................ ................................ ................................ ....................... 20 Physical and Chemical Properties and Environmental Fate

................................ ................................ ............. 20 Updated Information on Environmental Fate Studies

................................ ................................ ...................... 23 Hydrolysis

................................ ................................ ................................ ................................ ......................... 23

Soil Metabolism

................................ ................................ ................................ ................................ ................ 27 Field Dissipation

................................ ................................ ................................ ................................ ............... 29 Adsorption / Desorption Studies

................................ ................................ ................................ ..................... 30 Volatility 31 Measures of Exposure

................................ ................................ ................................ ................................ .......... 31 Measures of Aquatic Exposure and Exposure Estimates

................................ ................................ ............. 31 Comparison of Aquatic Exposure Estimates with Monitoring Data

................................ ........................... 33 Measures of Terrestrial Exposure

................................ ................................ ................................ .................. 34

Effects Characterization

................................ ................................ ................................ ................................ ........... 40 Aquatic Toxicity

................................ ................................ ................................ ................................ .................... 40 Terrestrial Toxicity

................................ ................................ ................................ ................................ ............... 45 Terrestrial Toxicity Assessment

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

Review of Incident Data

................................ ................................ ................................ ................................ ....... 48 Risk Characterization and Description

................................ ................................ ................................ ................... 50 Risk Estimation and Description

................................ ................................ ................................ ......................... 50

Non

- target Aquatic Animals and Plants

................................ ................................ ................................ ........ 50

Non

- target Terrestrial Animals and Plants

................................ ................................ ................................ ... 54 Risk Characterization and Description from exposure to pollinators

................................ ......................... 61

Terrestrial Plants

................................ ................................ ................................ ................................ ............. 61 Risk description associated with consumption of earthworms

................................ ................................ .... 61 Risk description through inhalation

................................ ................................ ................................ ............... 63 Risk from Drift to Aquatic Ecosystems

................................ ................................ ................................ .......... 63 Endocrine Disruptor Screening Program (EDSP)

................................ ................................ ................................ .. 64 Federally Threatened and Endangered (Listed) Species of Concern

................................ ................................ .... 66

Conclusions

................................ ................................ ................................ ................................ ................................ 6 7 Uncertainties, Limitations, and Identification of Data Gaps

................................ ................................ ................. 72 Data Gaps and Uncertainties

................................ ................................ ................................ .......................... 72

Environmental Fate

................................ ................................ ................................ ................................ .............. 72 Ecological Effects

................................ ................................ ................................ ................................ .................. 72 Terrestrial Exposure Assessment

................................ ................................ ................................ ................... 72

Reference Citations

................................ ................................ ................................ ................................ .................... 76 Bibliography of Ecological Effect and Environmental Fate Guideline Studies

................................ .................... 79

MRID/Accession Stu dies for Ecological Data:

................................ ................................ ................................ ... 79

MRID/Accession Studies for Environmental Fate Data:

................................ ................................ ................... 82

### 5 165

- 4 Bioaccumulation in fish

................................ ................................ ................................ ................... 86

APPENDICES

................................ ................................ ................................ ................................ ............................ 89 Appendix A: Chemical Structures of Ethoprop and Degradates

................................ ................................ ..... 89 Appendix B: Risk Quotients and Levels of Concern for Exposed Organisms

................................ ................. 93 Appendix C: Aquatic Exposure Modeling selected Input and Output

................................ ............................ 93 FL Sugarcane Scenario Input file

................................ ................................ ................................ ................... 94 FL Sugarcane Scenario Output Summary

................................ ................................ ................................ ..... 95 Maine Potato Scenario SWCC Model input and Output Summary

................................ ............................ 99 Groundwater Modeling Example Input

– Output Summary

................................ ................................ ..... 100 Appendix D. T

- REX Model Input and Output

................................ ................................ ............................... 103 Appendix E. STIR Model Example

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

### 6 List of Tables

Table 1. Summary of current uses of ethoprop.

................................ ................................ ................................ ...... 17 Table 2. Screening Level Estimates of Agricultural Uses of Ethoprop based upon 2004

– 2011 usage reports.

................................ ................................ ................................ ................................ ................................ ..................... 19 Table 3. SWCC model inputs for estimated environmental concentrations for aquatic exposure. 2

.................. 21 Table 4. Observed and calculated hydrolysis rates of ethoprop at different temperatures and pH conditions.

................................ ................................ ................................ ................................ ................................ ..................... 26 Table 5. Summary of ethoprop field dissipation studies.

................................ ................................ ....................... 29 Table 6. Estimated aquatic environmental concentrations for ethoprop for current uses (in ppb) using EFED standard pond and 1/10 year return frequency.

................................ ................................ ................................ ..... 32 Table 7. Representative hydrologic characteristics, estimated ethoprop usage intensity, and ethoprop detection rates in monitored community water systems (CWS).

................................ ................................ ........... 33 Table 8. Raw water ethoprop and SME detection rates and maximum observed concentrations for the five

monitored CWS.

................................ ................................ ................................ ................................ ........................ 34 Table 9. Input parameters for the T

- REX model for different uses for ethoprop.

................................ .............. 35

Table 10. Avian dose

- based ethoprop EECs (mg/kg

- bw) for three size classes of birds.

................................ ..... 36

Table 11. Mammalian dose

- based ethoprop EECs (mg/kg

- bw) for three size classes of mammals.

.................. 36 Table 12. Dietary based EECs (ppm) for application rates of ethoprop.

................................ .............................. 38 Table 13. Acute and chronic Toxicity endpoints for ethoprop.

................................ ................................ ............. 40 Table 14. Terrestrial toxicity endpoints for ethoprop.

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

Table 15. Summary of EIIS incidents as of June 2014.

................................ ................................ ......................... 48 Table 16. Acute and chronic risk quotients for freshwater and estuarine/marine fish.

................................ ...... 51

Table 17. Acute and chronic risk quotients for freshwater and estuarine/marine invertebrates.

........................ 52 Table 18. Acute and chronic risk quotients for freshwater and estuarine/marine sediment dwelling invertebrates estimated from water column EC50/NOAEC and pore water concentrations (peak and 21

- day).

................................ ................................ ................................ ................................ ................................ ..................... 53

Table 19 LD 50 ft

- 2 risk quotients from granular and incorporated applications of ethoprop.

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

Table 20. Avian dose

- based acute RQs

................................ ................................ ................................ .................... 57 Table 21. Avian dietary

- based acute and chronic RQs.

................................ ................................ ........................ 57

Table 22. Mammalian dose

- based acute and chronic RQs.

................................ ................................ .................. 59 Table 23. Mammalian dietary

- based chronic RQs

................................ ................................ ................................ 61 Table 24. Soil EECs generated from uses of ethoprop from the earthworm fugacity model.

............................. 62 Table 25. Endpoints compared to EECs in earthworms generated by the earthworm fugacity model.

........... 62

Table 26. Aquatic Effects Distance in feet from low boom applications.

................................ ................................ 64

### 7 

## Executive Summary

Purpose of Assessment

This screening

- level risk assessment examines the potential ecological risks associated with the uses of the pesticide ethoprop ( O

- ethyl

- S,S

- dipropyl phosphorodithioate ; alternate common name ethoprophos (interchangeable with ethoprop) . This risk assessme nt utilizes the best

available scientific information and current labels to evaluate the environmental fate and transport, and effects on non

- target organisms

. The end use products are emulsifiable concentrate and water dispersible granule formulations fo r ground application for various agricultural crops with maximum single annual application rate ranging from 1. 9 5 to 12 lb a.i./A. Ethoprop is currently used on cucurbits, hops, nursery stock, sugar beets, sweet potato, sugarcane, cabbage, corn, mint, tob acco, succulent ( L ima) beans, and potatoes.



## Summary of Relevant Environmental Fate, Transport, and Exposure Pathways

Ethoprop is moderately to strongly persistent in the environment ( d egradation half

- lives of 1 to 5 months by most pathways; but there is high uncertainty since field studies imply that persistence may vary significantly from site to site and possibly also may depend on previous use history)

. Ethoprop is highly mobile according to the McCall (1980 ) classification 1



### . Ethoprop is semi

volatile 2 

### . Exposure off

- site may occur via drift (however, as discussed below application methods are restricted to minimize drift) , runoff, and potentially via leaching to groundwater that

interacts with surface water s or is used for irrigation.



## Summary of Effects and Risk Conclusions

The conclusions of this assessment remain largely unchanged from previous assessments. Additional routes of exposure that were not modeled in previous assessments and are areas of

conc ern include consumption o f contaminated fish and earthworms

. When estimates of ethoprop exposure in terrestrial and aquatic environments are compared to the available ecotoxicity data, the results of the screening

- level assessment indicate a potential for risk to both aquatic and

terrestrial taxa.

Ethoprop is highly toxic to aquatic invertebrates and fish. Based on current uses and potential aquatic exposure levels, acute and chronic risk above the established levels of concern was identified for all aquatic taxa except for plants in both freshwate r and estuarine/marine

1 McCall, P. J., Swann, R. L., Laskowski, D. A., Unger, S. M., Vrona, S. A. and Dishburger, H. J. 1980. Estimation of chemical mobility in soil from liquid chromatographic

retention times, Bull. Environ. Contam. Toxicol., 24, 190

– 195.

2 A vapor pressure of ≥ 3.90 x 10

- 5 is considered to be predictive of “ Intermediate to high volatility under field conditions”. See: “Guidance for Reporting on the Environmental

Fate and Transport of the Stressors of Concern in Problem Formulations” EFED / OPP Memorandum dated January 25, 2010; availab le at:

http://www.epa.gov/pesticides/science/efed/policy_guidance/team_authors/endangered_species_reregistration_workgroup/esa_repor ting_fate.htm

.

### 8 environments. Environmental fate modeling and risk quotient determination indicate potential adverse effects on aquatic animal taxa. Acute and chronic risk to freshwater fish, estuarine/marine fish, freshwater invertebrates, and es tuarine/marine invertebrates, and both

freshwater and estuarine sediment invertebrates was identified. Risk above the level of concern was not identified for aqua tic plants based on one available diatom study.

Ethoprop is also highly toxic to terrestri al taxa. LD 50 

### per square foot analysis indicated that there is acute risk to both birds and mammals from granular formulations. There was also acute dose based and acute dietary based risk as well as chronic dietary risk to birds associated from EC appli cations. Similarly , there was acute and chronic dose based risk as well as chronic dietary based risk to mammals from EC applications. Both bird and mammals are predicted to be adversely affect ed by consumption of fish contaminated with ethoprop. Modelin g predicted risk to birds from acute dose based, acute dietary based and chronic dietary based exposure to contaminated fish. Mammals are also predicted to be a t risk from acute dose based as well as chronic dose based and dietary based exposure to contam inated fish. Other indirect routes of exposure may include consumption of contaminated earthworms in treated fields. Modeling

indicated acute avian risk from both dose

- based and dietary exposure as well as chronic risk from dietary exposure. Risk was no t identified for mammals consuming contaminated earthworms. Ethoprop is slightly to moderately volatile but modeling suggests that inhalation is not a risk to either birds or mammals. While ethoprop is applied by boom sprayer

, the coarse droplet size and maximum nozzle height of 4 feet specified on current labels eliminates most risk to terrestrial taxa through spray drift. Risk to terrestrial invertebrates is predicted from Bee

- REX modeling if exposure occurs to pollinators foraging on fields during the time of application. Results of past assessments and current application practices are designed to limit exposure . As

an insecti ci de, ethoprop would pose a risk to pollinators and other beneficial insects only if they are exposed

.

### 9 

## Introduction

The risk assessment is conducted as part of the Agency’s Registration Review process for pesticide active ingredients that was established under the Food Quality Protection A ct (FQPA

1996 )

. In an attempt to streamline documents produced by EFED, this risk a ssessment will rely, when appropriate, on information/data presented in the previously prepared problem

formulation and in the latest EFED Reregistration Eligibility Decision (RED) document en title d Environmental Risk Assessment for Ethoprop (DP dated Octo ber 5, 1998 The majority of information, included in the referenced two documents, will not be repeated here. Instead new data and/or information and any changes will be indicated. These changes are related to the following:

1. Description of new uses

2. Descr iption of new fate data

- Additional hydrolysis studies characterized for new model input

- Other fate data limitations with respect to parameterization of current models.

3. Description of new effects data

– Two additional avian reproductions studies

– Reevaluation and reclassification of the fish full life cycle study from invalid to supplemental.

4. Description and use of new and updated models.

As part of the Registration Review process, a detailed Problem Formulation (DP Barcode

D 353378 ) for this risk assessment was published to the docket [ Docket ID: EPA

- HQ

- OPP

- 200 8

- 0 560 ] in September 2009

. Th is problem formulation provide d the foundation for the environmental fate and ecological risk assessment being conducted for the labeled uses of

e thoprop

, based on the seven approved labels for this chemical at the time ( there are currently

three Section 3 end

- use product labels). . The problem formulation sets the obje ctives for the risk assessment and provides a plan for analyzing the data and characterizing the risk (USEPA 1998a). The Ecological Risk Assessment (DP Barcode D368753, 4/15/2010 )

, includes information on previous risk assessments; chemical mode of action; overview of the labeled use; environmental fate and transport characteristics; receptors (aqua tic and terrestrial effects, incidents and ecosystems potentially at risk); assessment endpoints; risk hypothesis and a conceptual diagram; along with the analys i s plan specifying the stressor of concern, measures of exposure/effects, integration of exposu re and effects, assessment method (deterministic and proba b ilistic ) and endangered species and drinking water assessments.

Ethoprop ( Ethoprophos, CAS Name: O

- ethyl

- S,S

- dipropylphosphorodithioate , and IUPAC

Name: 1

- (ethoxy

- propylsulfanylphosphoryl)sulfanylpropane ) , has a CAS Number of 13194

- 48

- 4

and a PC Code of 041101. It is a n organophosphate (OP) nemat i cide / insecti ci de with contact and stomach action poison and long residual effects. Ethoprop shares a common m echanism of toxicity with other OP’s, such as the toxicity expressed through a common biochemical

interaction with the cholinesterase enzyme. Although some degradates of ethoprop are cholinesterase inhibitors (the major route of toxicological effect for et hoprop and other

### 10 organophosphate insecticides), none of these were found in major amounts in the environmental

fate studies. Results from various aquatic and soil metabolism studies indicated that none of the individual environmental degradates were ever p resent at greater than about 4% of the applied ethoprop concentration. However the results of the submitted studies indicate that S

- ME

exposure may be significant in some surface waters ( s ee Appendix A for chemical names and structures of ethoprop and its degradates) . The S

- ME and O

- ME ethoprop degradates have been determined by the Health Effects Division to be ChE inhibitors and are included in the residues of concern for drinking water ( DP Barcode D342754 and D342793, HED Memorandum dated 7/10/1998) While these compounds might be considered of concern for ecological effects as well, given the fate parameters for parent ethoprop (e.g., degradation half

- lives of months by most pathways), i t is highly unlikely that SME residues alone or even total residues would be significantly higher than estimated with the current modeling. Therefore, all exposure assessments in this review are expressed in terms of parent ethoprop and are also expected t o conservatively represent the total toxic residues (TTR) of ethoprop.

The stressor is expected to reach terrestrial and aquatic receptors mostly from application runoff

rather than drift

, since labels require applications to be i ncorporated (some applic ations are incorporated by a wetting in process rather than mechanica l l y)

. EFED evaluate d the possibility of drift from applications that are n o t incorporated deeply enough or rapidly enough to eliminate drift potential. Based on laboratory data, ethopro p appears to be fairly persistent in soil and water. However, in the field, dissipation has generally been more rapid than expected from the laboratory studies

– some of the difference could potentially be due to enhanced degradation rather than dissipatio n processes such as volatilization and leaching

. Previous work with the organophosphate insecticides has also shown that volatilization and microbial degradation increases as soil moisture content and temperatu re increases

. Note also that, while this is n ot supposed to be a factor for the guideline field dissipation studies, at least in general there is a possibility of e nhanced microbial transformation at sites with a history of organophosphate pesticide use , including for ethoprop (Arbeli and Fuentes, 2007; Karpouzas et al., 1999; Racke and Coats, 1988; Singh et al., 2005; and Smelt et al., 1987 ) 3



### .



## Pesticide Use Characterization

Ethoprop is a restricted use organophosphate pesticide developed for control of soil insects and

3 Arbeli. Z. and C.L. Fuenes. 200 7. Accelerated biodegradation of pesticides: An overview of the phenomenon, its basis and possible solutions; and a discussio n on

the tropical dimension. Crop Protection 26(2007)1733

- 1746.

Karpouzas, D.G., ,A

. Walker

, R .J Froud

- Williams, and ,D

. S

. H Drennan . 1999. Evidence for the enhanced biodegradation of ethoprophos and carbofuran in soils from

Greece and the UK

. Pesticide Science 55 : 301

– 311,

Racke, K.D. and J.R. Coas. 1988. Comparative Degradation of Organophosphorus Insecticides in Soil: Specificity o f Enhanced Microbial Degradation. J. Agric. Food

Chem. 1988: , 193

- 199

. Singh, B.K.

, , A

. Walker and D

. J. Wright . 2005. Cross

- enhancement of accelerated biodegradation of organophosphorus compounds in soils: Dependence on structural

similarity of compounds

. Soil Biology and Biochemistry 37: 1675

- 1682.

Smelt, J. H., Crum, S. J. H., Teunissen, W. and Leistra, M., 1987. Accelerated transformation of aldicarb, oxamyl and ethopro phos after repeated soil treatments, Crop

Protection, 6: 295

- 303.

### 11 includes granular 

## (G) and emulsifiable concentrate (EC) formulations

. All applications must be incorporated either physically or by wetting in

. Ethoprop has been registered since the late 1960s for use on a variety of crops and turf grasses and may be formulated with other pesti cides and fertilizers. The pesticide may be applied by ground application methods only and one application per season is permitted.



## Drift / Exposure Reduction Label Language

Product labels have the following language to minimize the potential for drift and/or applicator

exposure from ground spray applications:

For ground boom applications, apply with nozzle height no more than 4 feet above the ground and only when wind speed is 10 mph or less at the application site as measured by

an anemometer. Use me dium or coarser spray as described according to ASAE 572 definition for standard nozzles or VMD for spinning atomizer nozzles.

For application only by motorized ground boom equipment and through irrigation systems if specified in crop

- specific use directi ons. Do not apply with liquid backpack sprayers, low

- pressure hand

- wand liquid equipment, sprinkler cans or hand

- held measuring containers, or by hand

- dipping of seedlings.

For use on ornamentals: only preplant broadcast application to soil for field nurs ery stock, which may only be mechanically transplanted into the treated area, and not until 72

hours after treatment.

This product is to be soil incorporated to a depth of at least 2 to 4 inches, during or immediately following application by mechanical m eans, including by rotary tiller, rotary hoe, springtooth harrow, or by double

- disking

.



## Method and Rates of Application:

Equipment

– The current labels for ethoprop indicate that the products may be applied by chemigation (i.e., drip irrigation and sprinkler irrigation), granule applicator [ i.e., tractor

- drawn mechanical spreader

, push

- type spreader , and backpack (for banana only)] , and ground sprayer equipment.

Met hod

– The insecticidal / nemat i cidal activity of ethoprop is highly dependent upon incorporating the product into the soil (mechanically or with water) soon after application to be effective, especially for those nematodes and insects which live deep in th e soil. All labels specify immediate soil incorporation by mechanical equipment for all products as they are being applied by ground equipment, or that watering

- in is to be conducted immediately following applications (for chemigation methods

, which are p ermitted on bananas and plantains only). No aerial applications of any type or hand

- held application methods are permitted. For some crops only

### 12 banded (not broadcast) applications are permitted (this restriction applies to the EC label for cabbage and th e EC and granular formulations for sweet potatoes).

Ethoprop is applied to most crops pre

- plant or pre

- emergent, but it can also be applied as follows: banana and plantain plants as soil

- directed liquid spray or granular broadcast (backpack spreader) arou nd the stems of the plants up to 2 times per year; and corn at cultivation after plant emergence until layby (i.e., the last time the corn plants are cultivated). In addition, potatoes may be treated prior to crop emergence.

Rate

– For soil treatments of field crops, the maximum label rates range from 2 lb active ingredient per acre (ai/acre) on cucumbers to 12 lb ai/A on potatoes (reduced to 9 lb ai /A for potatoes east of the Mississippi River) for agricultural crops. Close to a majority of the ethoprop total amount applied in the United States annually is to potatoes in the Pacific Northwest (PNW), where growers apply either granular or EC formulation at two application rates: up to 12 lb ai/A for control of nematodes, and up to 6 lb ai/A for control of wireworms. For bananas, the EC label states “apply 8 mL of MOCAP EC in a radius of 3/4 meter around each producing stem,” and the 10G and 15G granular labels similarly list rates to be applied per producing stem (at product rates which are equivalent to 6 grams or 0.2 ounces of and gel labels specify that multiple applications are permitted, but not more than 8 gallons of MOCAP® per acre per year for plant crops, or not more than 5 gallons of MOCAP® per acre per year for ratoon crops.

Timing

– For field c rops, applications must be pre

- plant or at

- plant and usually occur in the spring, before the growing season, with only one application per crop; only the banana / plantain labels permit more than one application per year. For some ratoon row crops, such as sugar cane, applications may occur only at the time of planting, and the crop grows for 3 to 5 years before a new crop is replanted. Applications to banana plants may be up to two times per year.



## Specific Label Directions by Crop

There are specificall y three different formulation types (the associated crop or other use sites for

each product are listed in Table 1):

1. An emulsifiable concentrate (EC) formulation. (EPA Reg. No. 5481

- 9041) . Includes uses on cabbage, hops, mint, potatoes, sweet potatoes, an d ornamentals.

2. A 15% Granular formulation (EPA Reg. No. 5481

- 9040) . Includes uses for bananas and plantains, cabbage, hops, snap and lima beans, field and sweet corn, cucumber, potatoes, sugarcane, and tobacco.

3. A 20% Granular formulation (EPA Reg. No. 54 81

- 9042 ) (for sugarcane only).

Additional details on the application specifications for each use site ( except nursery stock are

### 13 provided below ( refer to the original labels for exact languag e; the label language can very slightly for different marketing companies ).

Reg. no. 5481

- 9041 ( formerly 264

- 458), EC formulation :

• Cabbage:

o For at

- planting application to seeded crops, apply in 12 to 15 inch band on the row (36

- inch row spacing) and incorporate 2 to 4 inches deep with mechanical equipment during or immediately following treatment.

• Hops:

o [Post plant, pre

- emergence, Pre

- plant broadcast and incorporated application method options below.]

 [Method 1.] Mix MOCAP EC Nematicide

- Insecticide with sufficient water and broadcast apply immediately ahead of equi pment such as a double disc or rotary cultivator to thoroughly incorporate MOCAP EC

Nematicide

- Insecticide solution into the top 2 to 4 inches of soil.

 [Method 2.] Mix MOCAP EC Nematicide

- Insecticide with sufficient water and broadcast or band apply soluti on. Immediately apply 1 to 2 inches of overhead irrigation water to incorporate MOCAP EC

Nematicide

- Insecticide into soil. If band applying, apply in band at least 2

feet wide over row.

 [Method 3.] Mix MOCAP EC Nematicide

- Insecticide with sufficient

water and broadcast apply immediately ahead of equipment such as a double disc or rotary cultivator to thoroughly incorporate MOCAP EC

Nematicide

- Insecticide solution into the top 2 to 4 inches of soil. Wait a minimum of 3 days before planting the baby hops.

o [Pr oducing hops]. Apply in the spring after pruning, but before stringing or after

Harvest.

 Method 1. See above.

 Method 2. See above.

 [Method 4.] Chemigation Method: Apply Mocap EC Nematicide

Insecticide to prewetted hop yards through subsurface drip irrigati on (SDI) systems with pressure compensating emitters only. The Emission Uniformity (EU) of the drip irrigation system must be at 85 percent or greater (refer to USDA

- NRCS Practice Standard Code 441). Do not apply through any other type of irrigation system . Follow chemigation with enough irrigation to move MOCAP EC Nematicide

- Insecticide into the top 2

- 4 inches of soil.

• Mint:

o Apply preplant or after last harvest of the growing season. Spray with ground equipment, broadcast, over the field. Do not apply by air or through any type of irrigation equipment. This product is to be soil incorporated to a depth of at least 2 to 4 inches, during or immediately following application by mechanical means, including by rotary tiller, rotary hoe, springtooth harrow, or by double discing, or

### 14 by immediate application of 1 to 2 inches of overhead irrigation. Repeat irrigation

before soil dries.

• Potatoes (West of the Mississippi River):

o Apply prior to planting, at plantin g or prior to crop emergence.

o BAND (Insect control; maximum rate is 6 lb ai/Acre): Uniformly distribute spray in a 12 inch band over the row (36

- inch row spacing), either behind the planter shoe next to the closing disk or immediately in front of the planter shoe. Mix with the top 2 to 4 inches of soil duri ng or immediately following treatment.

o BROADCAST (Nematode control; maximum rate is 12 lb ai/Acre): Apply uniformly and immediately incorporate 2 to 4 inches deep using suitable tillage equipment . For some pests in Pacific Northwest: Apply uniformly and

i mmediately incorporate 4 to 8 inches deep using suitable tillage equipment. Best results are obtained with deep (6

- 8 inches), even incorporation.

• Potatoes (East of the Mississippi River):

o Apply prior to planting, at p lanting or prior to crop emergence.

o BAND (Insect control; maximum rate is 6 lb ai/Acre): Uniformly distribute spray in a 12 inch band over the row (36

- inch row spacing), either behind the planter shoe next to the closing disk or immediately in front of the planter shoe. Mix with the top 2 to 4 inches of soil during or immediately following treatment.

o BROADCAST (Nematode control; maximum rate is 9 lb ai/Acre): Apply uniformly and immediately incorporate 2 to 4 inches deep using suitable tillage equipment / mechanical equipment. Apply within 2 weeks before planting until prior to crop emergence

.

• Sweet Potatoes

o [2 to 3 weeks before planting.]

o BAND: Apply in a band 12 to 15 inches wide on the row (minimum 42

- inch row spacing) and incorporate 2 to 4 inches deep during or immediately following

tr eatment. Good results have been obtained by opening the row, applying in a 12 to 15 inch band on the row, bedding over and dragging

Reg. no. 5481

- 9042 (20% Granular) :

• Sugarcane:

o For application by ground equipment only. This product must be soil incorporated or covered with soil to a depth of at least 2 to 4 inches, during or immediately following application by mechanical means, including by disc hiller, rotary tiller, rotary hoe or springtooth harrow.

### 15 Reg. no. 5481

- 9040 (15% Granular) :

• Banana and Plantain:

o Apply 40 grams of product in a radius of 3/4 meter around each producing stem or 1.3 ounces of product in a radius of 30 inches around each producing stem. Before application, remove ground litter from area to be treated, and apply granules e venly. Incorporate into the soil immediately following application by

hand

- raking to a depth of at least 1 inch. For best results, apply just before irrigation or a rainy period. Repeat application in 6 months.

• Beans (snap and lima only):

o BROADCAST: Apply from 3 days before planting to at planting time. Mix with the top 2 to 4 inches of soil with mechanical equipment right after application. Use the higher rates in fields where nematode infestations have been especially

severe.

• Cabbage:

o BAND: Apply 13 pound s per acre (36 inch row spacing) or 0.9 pounds per 1,000 linear feet of row in a band 15 inches wide on the row at planting. Mix with the top 2 to 4 inches of soil with mechanical equipment during or immediately following application. DO NOT use as a seed furrow treatment or allow granules

to contact the seed.

o BROADCAST: Apply from 1 week before planting to at planting time. Mix with the top 2 to 4 inches of soil with mechanical equipment right after application.

• Corn (field and sweet):

o BAND (Insect control ; equivalent maximum rate is 3 lb ai/Acre ): Apply the granules in a 6 to 7 inch band on the row over a closed seed furrow at

- planting. Mix the granules with the top 1/2 inch of soil with mechanical equipment during or immediately following application 4



### .

o BA ND (Nematode control ; equivalent maximum rate is 6 lb ai/Acre ): Mix with the top 2 to 4 inches of soil with mechanical equipment right after application.

o BROADCAST (Insect control; maximum rate is 3 lb ai/Acre): Apply 3 days before planting to at planting time. Mix with the top 2 inches of soil with mechanical equipment right after application.

o BROADCAST (Nematode control; maximum rate is 6 lb ai/Acre): Apply 3 days before planting to at

- planting time. Mix with the top 2 to 4 inches of soil with

mechanical equipment right after application.

• Cucumber:

o BAND: Apply 13 pounds per acre (7

- foot row spacing) or 2.1 pounds per 1,000 linear feet of row in a band 12 to 15 inches wide on the row at planting. Prepare bed and knock off top to provide a level area for tre atment. Mix with the top 2 to 4 inches of soil with mechanical equipment right after application.

• Sugarcane:

4 The 0.5 inch incor poration depth specified appears to be inconsistent with the requirements for a 2

- inch or more incorporation depth for other types of application on

corn and for other crops.

### 16 o BAND: Apply evenly in a band 12 to 15 inches wide to the seed pieces in open furrows or beds and immediately cover with soil. Mix with the soil u sing a disc hiller or other suitable equipment as the cane is covered. Use the higher rates in

fields where nematode and/or wireworm infestations are severe. Minimum 6

- foot row spacing.

o (Similar directions on EPA Reg. no. 264

- 469 label)

• Sweet Potato:

o BAND: Apply 20 to 26 pounds per acre or 1.6 to 2.1 pounds per 1,000 linear feet of row in a band 12 to 15 inches wide on the row (minimum 42

- inch row spacing). Mix with the top 2 to 4 inches of soil with mechanical equipment right after application. Good r esults have been obtained by opening the row, applying product in a 12 to 15 inch band on the row, bedding over and dragging

• Tobacco:

o BAND: Apply in a band 18 to 24 inches wide on the row (42

- inch row spacing)

after the fertilizer has been listed or bedded. Mix with the top 2 to 4 inches of soil with mechanical equipment right after application.

o BROADCAST: Mix with the top 2 to 4 inches of soil with mechanical equipment right after application. Use a disc harrow or other cultivating equipment that wil l do a good job of mixing the MOCAP® 15% Granular with the soil.

• Sugarbeets [SLN

- 24(c) for Oregon ]

- EC Formulation :

o SHANKING AND INJECTING After seed l ing emergence or after transplanting seedling . Shank or inject solution 1 to 2 inches from plants and to

a depth of 2 to 4 inches on both sides of seedlings or transplants. Mix with sufficient water and inject product to side of plants close to but not in contact with the roots. Follow with irrigation.

o BROADCAST: Prior to seeding or transplanting . Apply immed iately ahead of equipment such as a double disc or rotary cultivator to thoroughly incorporate MOCAP EC solution into the top 2 to 4 inches of soil.

There are no registered homeowner uses. Current uses are further discussed in the Problem

Formulatio n (DP Barcode: D353378) and the section 3 new use drinking water assessment (D342755).

### 17 Table 1 . Summary of current uses of ethoprop.

Use Site Max. Rate per App Max. Rate

as lb ai/ Acre

or 1000 linear

feet Form Max

# Apps/

yr Max. App.

Rate/

cc &

yr Application Equipment //Type

NON

- FOOD/NON

- FEED USES

hops 3~ lb ai /A EC 1 NS Boom sprayer/ Ground/ Soil incorporation equipment

//Soil band treatment/ Soil

broadcast treatment

Nursery stock 3 (SLN =

6 5 ) l b ai /A EC 1 NS Soil incorporation equipment

//Broadcast

sugar beet (S pecial local

need supple

mental 24(c) Labeling only.) 3~ l b ai /A EC NS NS Shank/ Soil incorporation equipment/ Soil injector equipment

//Soil broadcast treatment/ Soil injection treatment/

Soil treatment

Tobacco 6 l b ai /A G 1 NS Granule applicator

//Soil broadcast treatment

.4800 linear ft G 1 NS Granule applicator

//Soil band treatment

FOOD/FEED USES

Banana .0132 l b / plant G 2/1 yr NS Spreader

//Soil broadcast treatment

beans,

succulent (lima) 8.1 l b ai /A G 1 NS Granule applicator //Soil broadcast treatment (a)

.1828~ linear ft EC 1 NS Shank/ Soil incorporation equipment/ Soil injector equipment

//Soil band treatment/ Soil injection treatment/ Soil shanking treatment

beans,

succulent (snap) 8.1 l b ai /A G 1 NS Granule applicator

//Soil broadcast treatment

.1828~ linear ft EC 1 NS Shank/ Soil incorporation

5 See: CA120009 expires in November 30, 2017.

OR090003 expires on December 31, 20 14.

The higher 6.05 lb ai/acre rate is only allowed on the SLN label for Easter lilies grown for commercial bulbs in California a nd Oregon. Use in Oregon at this rate is

limited to Curry County. For the bulk of ornamentals in the U.S. the maximum rate is 3.0 lbs a.i./acre.

### 18 Use Site Max. Rate per App Max. Rate

as lb ai/ Acre

or 1000 linear

feet Form Max

# Apps/

yr Max. App.

Rate/

cc &

yr Application Equipment //Type

equipment/ Soil injector equipment

//Soil band treatment/ Soil injection treatment/ Soil shanking treatment

cabbage 5.1 l b ai /A G 1 NS Granule applicator

//Soil broadcast treatment

.1125 linear ft EC 1 NS Soil incorporation equipment

//Soil band treatment

corn, field 6 l b ai /A G 1 NS Granule applicator

//Soil broadcast treatment

.1500 linear ft G 1 NS Granule applicator

//Soil band treatment

corn, sweet 6 l b ai /A G 1 NS Granule applicator

//Soil broadcast treatment

.1500 linear ft G 1 NS Granule applicator

//Soil band treatment

cucumber 1.95 lb ai /A G 1 NS Granule applicator

//Soil band treatment

mint/ peppermint/ spearmint 3~ lb ai /A EC 1 NS Soil incorporation equipment

//Soil broadcast treatment/ Soil incorporated treatment Application may be preplant or after last harvest of the growing season (mint is the only crop with postharvest applic.

a llowed. ) There is a minimum 225

- day preharvest interval required.

plantain .0132 l b / plant G 2/1 yr NS S preader

//Soil broadcast treatment

potato,
white/irish 12 W of

Miss. River

or 9 E of the

Miss. River lb ai /A G 1 NS Granule applicator

//Soil broadcast treatment Apply within 2 weeks before planting

until prior to crop emergence.

12 (9 E of

Miss. lb ai /A EC 1 NS Soil incorporation equipment

//Soil broadcast treatment

### 19 Use Site Max. Rate per App Max. Rate

as lb ai/ Acre

or 1000 linear

feet Form Max

# Apps/

yr Max. App.

Rate/

cc &

yr Application Equipment //Type

River)

.2100 linear ft G 1 NS Granule applicator

//Soil band treatment

.2063 l inear ft EC 1 NS Soil incorporation equipment

//Soil band treatment

sugarcane 4 lb ai/A G 1 NS Soil incorporation equipment

//Soil band tr m t

. “Apply to seed pieces in opened furrow or beds and immediately cover with 2

- 4

inches of soil. Mix the soil

with a disc hiller or other suitable equipment as the cane

is covered.” .5600 linear ft G 1 NS

sweet potato 3.9 l b ai /A G 1 NS Granule applicator

//Soil band treatment

.3 `

234 linear ft EC 1 NS Soil incorporation equipment

//Soil band treatment

Cc = Crop cycle.

Yr = Year. ~ = In this table indicates a use rate that can be interpreted slightly differently depending on how it is calculated. The variation is not significant for the risk assessment. NS = Not specified. For all crop use sites only one application is allowe d per growing season

. For bananas and plantains there is a minimum interval of 180 days. All applications are from a few days before planting or at planting unless otherwise specified.



### A summary of ethoprop usage rates by crop in recent years is provided in Table 2

. Only the green bean

, cucumber, potato, and sugarcane crop sites are estimated to have annual percent crop treated (PCT) rates above 5% and only potatoes and sugarcane reach as much as 10% PCT. Th e PCTs have been consistently low in evaluations by OPP

- Biological and Economic Analysis

Division (BEAD) in recent years (see also: Screening Level Usage Analysis (SLUA)

. February 14, 2008: OPP

- BEAD). Field corn usage was apparently too low to even be est imated and the rate of usage on sweet corn was very low with only 10,000 acres estimated to be treated with ethoprop annually.

Table 2

. Screening Level Estimates of Agricultural Uses of Ethoprop based upon 2004

– 2011

### 20 usage reports.

Crop Average Percent Crop Treated

Lbs. A.I. Average Maximum

1 Beans, Green 40,000 5 10

2 Cabbage 3,000 <2.5 <2.5

3 Cucumbers 4,000 <2.5 5

4 Dry Beans++/Peas 7,000 <1 <2.5

5 Peanuts++ 2,000 <1 <2.5

6 Potatoes 100,000 5 10

7 Sugarcane 100,000 5 10

8 Sweet Corn 7,000 <1 <2.5

9 Tobacco 8,000 <1 <2.5 Prepared August 14, 2013.

All numbers are rounded.

<2.5: indicates less than 2.5 percent of crop is treated.

< 1: indicates less than 1 percent of crop is treated.

++ There are no current active registrations listing these uses. Cancellations were issued for dry beans and peanuts in 2008. Usage in this report may reflect usage occurring before cancellation or a s a result of using existing stocks after cancellation.

Site Name Cancelled Date Dry Beans 10

- Apr

- 08

Peanuts 10

- Apr

- 08



## Fate and Exposure Characterization

Physical and Chemical Properties and Environmental Fate

The environmental fate of ethoprop has previously been summarized in the EFED Problem

Formulation for registration review (DP Barcode D353378, 10/30/2008)

, the Ecological Risk

Assessment (DP Barcode D368753, 4/15/2010), and a Drinking Water Exposure Assess ment (DP Barcode D375927, 4/15/2010) ; the Drinking Water Assessment has been recently updated for the registration review (DP Barcode D428028 ) . Some limited additional information has been

reviewed for this risk assessment and is discussed below. Emphasis is on the fate of the parent since no metabolites appear to form at greater than 10 % of applied.

Ethoprop degrades primarily by microbial metabolism as well as the abiotic process of hydrolysis. The aerobic soil metabolism half

- life is 100 days in the guideline study (these data are more limited than would be required under current regulatory guidance recommending that

metabolism rates be examined in at least four test soils for OCSPP 835.4100 aerobic soil metabolism studies). Field dissipation half

- liv es are 3 to 60 days at approximately 24 different

### 21 sites. There are no acceptable anaerobic aquatic metabolism studies available but a 100 day half

life was observed in an anaerobic soil metabolism study. Degradation due to hydrolysis varies with pH, with e stimated half

- lives at 25 °C estimated of 205 days for acidic (pH 5) waters, 150

- 155 days for waters with neutral pH (pH 7), and 39 days for alkaline waters (pH 9). Ethoprop is not subject to photolysis. Ethoprop is classified as highly mobile with a med ian K
oc 

### of 109 in

five test soils 6



### .

Ethoprop is a soluble (aqueous solubility: 843 ppm), somewhat volatile (vapor pressure: 3.5 x 10

-

4 

### mm to 8

. 3 x 10

- 4 

### mm Hg at 2 5

- 2 6 o 

### C) insecticide/nematicide. Based only on laboratory data from previously reviewed and accepted studies

, ethoprop is fairly persistent (most degradation pathways with first order kinetic half

- l ives of a few months). I n field studies, dissipation was generally more rapid than would be predicted on the basis of degradation alone (from rates measured in the laboratory studies), especially under warm, moist conditions. The range in field dissipation rates was quite wide between sites / studies, however, and furthe rmore, the mass leaching captured in deeper depth increments of soil was significant enough at some sites to result in much slower dissipation rates when calculated from the total soil profile. The field data are not adequate to develop estimates of actual degradation rates for ethoprop in soil and are therefore only used for characterization of uncertainties in the current risk assessment.

Some new models have been incorporated into the ecological exposure assessment (discussed further below) and additio nal data not used in the most recent ecological risk assessments has been incorporated into the current assessment. A new hydrolysis rate was calculated, and other minor changes in the fate modeling are noted in Table 3

.

Some published sources (including studies submitted to regulatory agencies in other countries) indicate that it is possible that aerobic soil, aerobic aquatic, and hydrolysis rates m ay be faster than estimated from guideline studies. This information has been used for further

characteriza tion of ethoprop environmental fate; however, these data have not been submitted to the Agency and have not been reviewed in detail by EPA.

The environmental fate of ethoprop is further summarized in DP Barcodes D368753 (4/15/2010

EFED New Use Assessment for Chemigation on Hops). Additional details on hydrolysis, field dissipation, and published soil metabolism studies are provided below as they are relevant to

refinements used in the current risk asse ssment.

Table 3 . SWCC model in puts for estimated environmental concentrations for aquatic

e xposure. 2

Chemical name Model Input Value /

Additional Notes MRID Reference / Comment

Molecular Weight 242.3 (parent, used for Product chemistry Although some degradates in the TTR have a much

6 McCall, P. J., Swann, R. L., Laskowski, D. A., Unger, S. M., Vrona, S. A. and Dishburger, H. J. 1980. Estimation of chemical mobility in soil from liquid

chromatographic retention times, Bull. Environ. Contam. Toxicol., 24, 190

– 195.

### 22 Chemical name Model Input Value /

Additional Notes MRID Reference / Comment

TTR) data lower MW, parent is the most persistent moiety and is expected to dominate exposure.

Solubility 843 mg L

- 1 Product chemistry

data

Vapor pressure

(mm Hg) 0.000827 Product chemistry

data Other reported values:

3.5 x 10

- 4 mm Hg

4.6 x 10

- 2 Pa @ 26 o C (California Environ. Monitoring & Pest Mgmt., 1990). Reports similarly high VP for other organophosphates.

79 mPa @ 20 o C (OPPTS 830.7950)

123 mPa @ 25 o C(92/69/EC A8)

Henry’s Law Constant Calculated by model Product chemistry

data Reported to be 1.32 E

- 08 atm.m 3 /mo

– may also be

calc. value.

pH 7 Hydrolysis half

- life (days) 150 41270703

00067321

00160166 Previous value was “stable” , derived as a default value from MRID 41270703 (not enough data to calculate a hydrolysis rate over the 30 day study).

Data from MRID 00067321 and MRID 00160166 at other temperature and pH levels were used to interpolate a new estimate for the hydrolysis rate at pH 7 and 25 o C.

Soil Photolysis half

- life (days) Stable ( not used) 41270704

41568102

43833501

Aquatic photolysis half

life (days) Stable 41270702

41568101

43833502

Aerobic soil metabolism

half

- life (days) 300 days (3 x single study value) 00160171 When compared to published values in the

literature and field studies it appears this value might be high. Studies on additional soils would reduce the uncertainty regarding model input

values.

Aerobic aquatic (water

column) metabolism

half

- life (days) TTR = 0

(insufficient data to accurately calculate

TTR persistence)

Supplemental data:

Parent DT50 = 71 (low

organic matter, pH = 8.5)

Parent DT50 = 95 (high O.M., pH = 8)

Parent t 1/2 : 162 days 44989502 This value set to a zero rate and a hydr olysis rate

was used instead to account for the transformation rate in the pond.

### 23 Chemical name Model Input Value /

Additional Notes MRID Reference / Comment

(upper 90% confidence

interval of registrant study ) (supplemental)

Anaerobic soil

metabolism half

- life (days) 100 days ( ultimately not used in modeling) 0016071

Anaerobic aquatic (benthic) metabolism

half

- life (days) 0 None In previous assessments was 50 days (no study conducted; 0.5 x anaerobic soil metabolism) 1

For this assessment the newly calculated hydrolysis

rate was used to account for the transformation rate in the pond.

K oc / K d / K f 109

K d : 2.1 L/kg in silt loam

soil; K ads : 1.08

- 3.78 43778601 New value (previous modeling used a Kd) was determined to be appropriate for environmental fate modeling. Median Koc value used to account for one apparent outlier: Koc values of 43 (loamy sand, 2.1% OC), 50 (Pond sediment, 4.3% OC), 109 (sandy loam, 0.8% OC), 129 (silt loam, 0.7% OC), and 1652 (clay, 0.4% OC).

Application Rates 3 to 12 lb ai/ acre NA Rate determined by the maximum application rate allowed on the modeled crop site.

Application Efficiency 0.99 NA

Number of Applications 1 NA

Application Method Soil incorporated, broadcast (except hops) NA

Incorporation Depth (cm)

– except application to hops was not incorp. 5 NA 7 cm used for PRZM

- GW modeling, which is only used for characterization purposes of potential contributions from groundwater when it impacts surface waters through lateral flow or use in irrigation.

IPSCND (post

- harvest foliar pesticide

disposition) 1

(Surface applied) NA

Foliar degradation half

life (days) 0

(no data) NA

1 Per EFED guidance document when no hydrolysis is assumed (version 2, 2/28/2002) , the method used in previous EFED assessments). In the current assessment a hydrolysis rate was instead calculated \ \ 2 Data was selected per

... ( Add the guidance for selection of input parameters, current version is 2.1 an



## Updated Information on Environmental Fate Studies

Hydrolysis

In an effort to provide more precise data for modeling (modeling of pesticide leaching to groundwater was particularly sensitive to this parameter) EFED utilized additional data sources

### 24 for more precise calculation of modeling inputs for hydrolysis.

A two

- step process was used to estimate an ethoprop hydrolysis rate at pH 7 and 25 C, a standard input value generally used for EFED models. These calculations were based upon an earlier study submitted to the Agency (MRID 160166) with hydrolysis rates calcula ted in pH 3, 6, and 9

buffered solutions incubated at 20 o 

### C and 35 o 

### C.

The first step was to calculate a Q10 value ( t he factor by which the rate of a reaction increases for every 10

‐ degree rise in the temperature) f or pH 7 waters based upon the measured values at pH 3, 6, aqnd 9 at the two temperatures

- the results of which are shown in Figure 1 . The Q10 values for each pH were used to calculate an interpolated Q10 value for pH 7 using the equation shown in Figure 1.

The seco nd step was to convert the measured hydrolysis rates / half

- lives (assuming first

- order kinetics) to 25 o C, these calculated values are plotted in Figure 2 ; a polynomial equation was used to interpolate an estimate for the hydrolysis half

- life at pH 7 and 25 o C ( Figure 2 ). Observed and calculated values are summarized in

### 25 Figure 1 . Variance of ethoprop Q10 values with solution pH (from MRID 00160166). 

# y = 1.1511e 0.0743x



# R2 = 0.9999

0 0.5

1 1.5

2 2.5

0 2 4 6 8 10Q10 Value



# pH of Test System Q10 Coefficient Calculation

### 26 Figure 2 . Measured ethoprop hydrolys half

- lives adjusted to 25o C and a fitted equation.

pH 7 Hydrolysis half

- life (days) 150 41270703

00067321

00160166 Previous value was “stable” , derived as a default value from MRID 41270703 (not enough data to calculate a hydrolysis rate over the 30 day study).

Data from MRID 00067321 and MRID 00160166 at other temperature and pH levels were used to interpolate a new estimate for the hydrolysis rate at pH 7 and 25 o C.



### http://www.iaea.org/inis/collection/NCLCollectionStore/_Public/30/038/30038768.pdf

Table 4 . Observed and calculated hydrolysis rates of ethoprop at different temperatures and pH conditions.

Source pH temp. Measured

T

1/2

, days k TC, days

- 1 T Kelvin Q10

calc. Target Temp.

C Estim ted

T 1/2 , days

@25 C Degrad.

Rate Adj.

Factor

1.) 3 20 196 0.0035 293 1.44 25 163 0.8338 

## y =

- 8.4145x 2 

## + 76.34x + 33.236
R2 = 0.9233

0 50 100 150 200 250

0 1 2 3 4 5 6 7 8 9 10Half-life, days



# Test pH Ethoprop Hydrolysis T 1/2 Values adjusted to 25 Celsius

### 27 1.) 3 20 252 0.0028 293 1.44 25 210 0.8338

1.) 3 35 112 0.0062 308 1.44 25 161 1.4385

1.) 3 35 147 0.0047 308 1.44 25 211 1.4385

1.) 6 20 231 0.0030 293 1.80 25 172 0.7458

1.) 6 20 273 0.0025 293 1.80 25 204 0.7458

1.) 6 35 98 0.0071 308 1.80 25 176 1.7977

1.) 6 35 112 0.0062 308 1.80 25 201 1.7977

1.) 9 20 44.1 0.0157 293 2.25 25 29 0.6672

1.) 9 20 39.2 0.0177 293 2.25 25 26 0.6672

1.) 9 35 10.5 0.0660 308 2.25 25 24 2.2466

1.) 9 35 14 0.0495 308 2.25 25 31 2.2466

2.) 9 25 83 0.0084 298 2.25 25 83 1.0000

Calculated Half

- lives Using Interpolated Q10 Value for 25 C

3.) 5 25 >>30 0.0034 298 1.67 25 205 1

3.) 7 25 >>30 0.0045 298 1.94 25 15 0 1

3.) 9 25 83 0.0178 298 2.25 25 39 1
Key : 1.) MRID 00160166. 2.) MRID 41270703. 3.) Temperature

- adjusted hydrolysis values and predictions for pH 5, 7, and 9 at



### Soil Metabolism

Guideline data

.

T he results from the available aerobic soil metabolism study established a half

- life of 100 days. At 252 days post

- treatment, 24.8% of the applied radioactivity was not degraded ethoprop . The major degradate was CO 2 

### (accounting for 53.9% of the applied radioactivity by the end of the study); the major nonvolatile degradates were identified as O

- ethyl

- S

- methyl

- S

propylphosphorodithioa te (SME), O

- ethyl

- O

- methyl

- S

- propylphosphorodithioate (OME), and O

ethyl

- S

- propylphosphorothioate (OHE or M1), with the measured amount of each accounting for less than 4% of the applied, at every sampling interval. In addition, an anaerobic soil

metaboli sm study showed a similar rate of degradation, with the half

- life of approximately 100 days. During the 56

- day anaerobic incubation test, a total of 2.25% of the radioactivity had been volatilized, and 10.5% was remaining in the soil in an unextractable f orm. The degradates OME and OHE (M1) each accounted for less than 1% of the applied radiolabeled parent ethoprop

.

An aerobic aquatic metabolism laboratory study was conducted with sediment/water systems.

### 28 The reported data indicated a half

- life value 75 days in the sand sediment/water system and a

half

- life of 90 days in the silt loam sediment/water system. Nonextractable residue amounts were reported, and in addition, specific degradates were analyzed. The degradates, OHE (M1) was identified as the degr adate reported to be present at the greatest concentration, but it was never reported at greater than about 1% at any of the time intervals of analysis.

Ancillary data

.

Additional soil metabolism studies have been reported in the literature but these studies are not available for a full review as with the environmental fate studies submitted to fulfill Agency guidelines. A summary review of laboratory metabolism and field dissipation studies (include studies submitted to EPA and other published studies) by staff members of the ethoprop registrant (Jones and Norris, 1998) covers most of the available data. Additional studies are referred to in some European regulato ry documents

. The following points are particularly relevant for comparison to the data available through the US regulatory process:

1. One European Food Safety Agency (EFSA) document 7 

### report s the use of a 22.8

- day half

lif e (normalized to 10kPa soil moi sture and 20 C with a Q10 of 2. 2 from fate data for modeling of ethoprop degradation when used to calculate regulatory endpoints for groundwater (page 58 of 72 in the report). This converts to a value of approximately 19 days at 25 C (EFED does not currently routinely calculate variatio ns in degradation with the soil moisture level). There were a total of six aerobic soil metabolism studies with

half

- lives of 10 to 113 days (3 studies conducted at 20 C, 2 at 22 C, and 1 at 25 C

– which was also the soil incubated at 25 C); see page 53 of the report. No information about the characteristics of the test soils was reported nor were study references provided.

2. The recommended input for sorption modeling was a calculated mean Kfoc of 111 mL/g and a Freundlich 1/n exponent value of 0.89 (page 5 4).

Some European regulatory agency reviews are available online but the publicly available

documentation is limited. From these it has been determined that aerobic soil metabolism studies for 3 test soils have been submitted and reviewed by the Netherlan ds National Institute of Public Health and the Environment (RIVM) 8



### The studies used for calculation of the European regulatory agency environmental fate values

7 

### EFSA Scientific Report (2006) 66, 1

- 72, Conclusion on the peer review of ethoprophos. Available at: http://www.efsa.europa.eu/en/efsajournal/doc/3089.pdf ; also available at: Also available at: http://www.fytoweb.fgov.be/NL/doc/EthoprophosEFSA.pdf

8 A “First Draft” review by Trijntje van der Velde

- Koerts and Bernadette C. Ossendorp,

N ational Institute of Public Health and the Environment (RIVM), Bilthoven, The Netherlands is available at:

http://www.fao.org/fi leadmin/templates/agphome/documents/Pests_Pesticides/JMPR/Evaluation04/Ethopropos.pdf

An evaluation of ethoprop metabolism in three test soils is cited and reviewed:

Greenslade D, Ward J and Hopkins R. 1984. (14C)

- Ethoprop: aerobic soil metabolism and rate of degradation. Hazleton Laboratories Europe, Ltd. Harrogate, North

Yorkshire, UK. Report no. 3594

- 68/33. Provided by Bayer Crop Science AG, Monheim, Germany (Document No: R009121). Non

- GLP. Unpublished.

### 29 have not been reviewed by the Agency. Nonetheless, these secondary sources do suggest that an

a dditional conservative factor for the aerobic soil metabolism rate may not be needed in environmental fate modeling for ecological risk

. Further refinement of the ecological risk assessment may be possible if additional laboratory metabolism studies are ma de available for Agency review.

Field Dissipation

A number of field dissipat i on studies have been conducted and submitted to support the registration of ethoprop. The reported half

- lives are between 3 and 60 days (Table 5 ). These half

lives were generally calculated for only the top soil layer sampled which was generally about 0

to 6 inches. The difference in half

- lives between laboratory and field studies may be partially due to leaching/runoff, as well as to the increase d soil moisture and temperature in the field soils, which might result in increased microbial degradation and volatilization

. These data suggest that ethoprop degradation may frequently be more rap id under field conditions than reported in the guideline la boratory soil metabolism studies but it is not possible to separate out the portion of dissipation attributable to degradation processes.

Table 5 . Summary of ethoprop field dissipation studies.

Study

location Soil Type

or Series Depth of Sample,

ft. Formu lation Rate,

Lb ai / A or

other Reported dissipation

half

- life, days Authors MRID

Hanover Co., VA Sandy loam 0.5 Uk. 5

– 25 ppm <8 Boyd

and

Duval 00092040

NE Silt loam 0.25 EC 12 lb ai /A <3 a Guyton 00160174

NJ Loamy sand 0.25 EC 12 lb ai /A <30 a Guyton 00160174

MO Clay 0.25 EC 12 lb ai /A <30 a Guyton 00160174

IL Silt loam 0.25 EC 12 lb ai /A <30 a Guyton 00160174

IL Silty clay

loam 0.25 EC 12 lb ai /A <30 a Guyton 00160174

Madison,

WI ? 0.5? G 1 lb ai/A <9 Davis

and Boyd 00092033

York, NE ? 0.5? G 1 lb ai/A 7

- 3 0 Davis

and Boyd 00092033

WI, NE,

and MO ? 0.5? G 2 lb ai/A 7

– 36 b Davis

and Boyd 00092033

Hanover Co., VA Sandy loam 0.5? G 1

- 5 lb ai/A <21 Davis

and Boyd 00092033

Hanover Co., VA Sandy loam 0.5? G 10

- 50 lb

ai/A 28

- 42 Davis

and Boyd 00092033

FL Near
Bradenton 0.5 G 12 lb ai/A 40 Norris (1987) 40470601

FL Near Lake 0.5 EC 12 lb ai/A 13 Norris 40470601

### 30 Study

location Soil Type

or Series Depth of Sample,

ft. Formu lation Rate,

Lb ai / A or

other Reported dissipation

half

- life, days Authors MRID

Hamilton (1987)

Suffolk Co., NY (multiple sites) Various 0.5? G 9 ai / A 17

- 60 Norris (1987) 40519901

NC Sand (Norfolk series; pH 6.3, 1.4% OM) 0.5? EC, G 12 lb ai/A (pre to potatoes) 8

- 10 Norris (1990) 41712401

WA Loamy sand (Timmerman series; pH 6.3, 2%OM) 0.5? EC, G 11.8 lb ai/A (pre to potatoes) 36

– 48 Norris (1990) 41712401

NC Sandy loam (Norfolk
series; 2.0% OM) (turfed) 0.5 G 20 lb ai/A 18 Norris (1997) 44398001

NC Sandy loam (Norfolk; 2.2% OM) (bare soil) 0.5 G 20 lb ai/A 13 Norris (1997) 44398001

FL Sand (Fuquay
series; 1.8% OM) (turfed) 0.5 G 20 lb ai/A 10 Norris (1997) 44398001

FL Loamy sand (Fuquay; 1.2% OM) (bare soil) 0.5 G 20 lb ai/A 12 Norris (1997) 44398001

a 

### Significant leaching of residues occurred at these sites (up to 1.71 ppm detected at depths of up to 12

inches.

b 

### Although specific field dissipation half

- lives were not calculated it is notable that residues in the top soil layer at 59

– 60 days were 1.3 to 1.4 ppm at NE, 0.2

– 0.7 ppm at MO, and 0.00 to 0.01 ppm at WI.



### Adsorption / Desorption Studies

Ethoprop wa s determined to have K f 

### values of of 0.53 (loamy sand, 2.1% OC), 1.24 (Pond sediment, 4.3% OC), 0.51 (sandy loam, 0.8% OC), 0.53 (silt loam, 0.7% OC), and 4.12 (clay, 0.4% OC) (MRID 43778601). The corresponding K oc 

### values were: 43 (loamy sand, 2.1% OC),

5 0 (Pond sediment, 4.3% OC), 109 (sandy loam, 0.8% OC), 129 (silt loam, 0.7% OC), and 1652 (clay, 0.4% OC). Ethoprop is considered to be highly mobile in soil (see classification system of McCall, 1980)

. The l ow K f 

### values (except for the one clay, low organic carbon test soil)

### 31 determined from a batch equilibrium study (< 1.3 in the other 4 test soils) , suggest s a limited potential for sorption to soil. Mobility information on OHE (M1) indicates that it also is highly

mobil e; however, the mobility of the other degradates (OME, SME, and S,Sdipropyl phosphorodithioate [SSDP or M2]) is not known; however, the similarities in structure of these compared with parent ethoprop and OHE (M1) suggest that these other three degradates will all have similar, moderately low soil sorption values.

For ecological exposure modeling the median Koc value of 109 was used (taking the median rather than the mean of these values reduces an overwhelming dominance of a single high value

which would occur in this case with the very high and possibly outlier K
oc 

### value for the clay soil). This is consistent with values used for representative modeling elsewhere (e.g., Koc = 111 was used in EFSA, 2006 available at: http://www.efsa.europa.eu/en/efsajournal/doc/3089.pdf ).

Volatility

In a laboratory volatility study, the resulting volatiles comprised only a small amount of the applied dose, with parent ethoprop being about one quarter to one

- half of the volatile components on day 7, the last day of sampling. The vapor pressure of ethoprop is moderate to high, depending on the classification scheme used (the vapor pressure is 3.5 x 10

- 4 

### mm to 8

. 3 x 10

- 4 

### mm Hg at 2 5

- 2 6 o 

### C mm Hg; between 1 x 10

- 8 

### and 1 x 10

- 3 

### mm Hg is generally considered to be in the moderate range for pesticides), and it has a Henry’s Law Constant which is moderately low (1.5 x 10

- 7 

### atm m3/mol ) 9



### .



## Measures of Exposure

Measures of Aquatic Exposure and Exposure Estimate s

Screening

- level EECs of ethoprop in surface water, pore water and sediment were generated based on maximum labeled use rates ( Table 1 ) . Simulations were conducted using the tier II

surface water concentration calculator (SWCC)

. For agricultural and certa in non

- agricultural uses, exposure concentrations for surface ecological assessments are estimated based on EFED’s Tier II aquatic model PRZM/VVWM. A graphical user interface Surface Water Concentration Calculator (SWCC v.1.106, May 6, 2014), developed by the EPA, was used to facilitate inputting chemical and use specific parameters into the appropriate input files and chemical files, replacing the older PE5 shell (November 2006), which used PRZM3 and EXAMS. The SWCC estimates pesticide concentrations in water bodies that result from pesticide applications to land. The calculator was designed for regulatory applications as applied in the Office of Pesticide Programs, USEPA, as well as PMRA, Health Canada. The calculator uses the Pesticide Root

Zone Mode l (PRZM v5.0+, May 6, 2014) and the Varying Volume Water Body Model (VVWM, May 6, 2014, a replacement for the older EXAMS model). The PRZM crop / use site scenario is the basic file which describes the local or regional climatological information, soil hy drology, soil characteristics, crop characteristics, and the pesticide properties necessary to determine

9 A vapor pressure of > 10

- 5 Torr is considered predictive of “i ntermediate to high volatility under field conditions ”. See:

### 32 pesticide loadings to surface water. This basic file constitutes the first part of the “exposure scenario.” It simulates the processes in the agricul tural field, such as runoff and erosion, on a daily time step. The runoff and erosion flux output data from PRZM are used as chemical loadings to the VVWM, which simulates surface water, in order to predict the EECs. The VVWM is conceptually similar to t he current EXAMS

- based model in that both are 2

- compartment models driven by first

- order processes. It simulates the USEPA standard water

bodies (i.e. , farm pond and/or index reservoir) but with greater efficiency and flexibility for incorporation into a user interface. The VVWM also allows for variations in water body volume on a daily basis due to runoff, precipitation, and evaporation. Temperature, wind speeds, and pesticide dissipation processes are also allowed to vary daily. EE C s were determined u sing the standard pond scenario which describes a vulnerable surface waters scenario for the VVWM component of the modeling exercise ( Table 6 )

.

Table 6

. Estimated aquatic environmental concentrations for ethoprop for current uses (in ppb) using EFED standard pond and 1/10 year return frequency

.

Crop Scenario

State Rate;

lb

ai/A Peak 

### 4

- day 21

- day 60

- day 90

- day Yr overall PW_pk PW_21

corn MS 6.0 141.0 

### 138.0 130.0 116.0 107.0 56.3 25.6 85.3 85.5
Sugarcane FL 4.0 58.1 

### 57.2 53.7 49.6 47.6 27.2 8.9 36.7 36.6

Corn IL 6.0 47.1 

### 46.4 44.2 39.8 37.4 18.1 11.5 37.9 39.6
Sugarcane LA 4.0 47.0 

### 46.2 44.8 40.8 37.9 21.2 7.9 28.3 28.2

Corn OH 6. 0 42.3 

### 42.0 40.9 36.7 33.7 17.1 7.2 26.0 26.1
Cabbage FL 5.1 42.2 

### 41.6 39.5 36.1 33.0 14.4 7.3 26.1 25.9

Corn NC 6. 0 33.5 

### 33.0 31.1 27.7 25.6 15.2 6.4 21.1 21.0

Potato ME 9.0 32.6 

### 32.1 30.8 28.4 26.4 15.2 9.8 27.0 27.9 Snap

beans OR 8.1 32.1 

### 31.7 30.1 26.9 25.2 14.9 8.9 21.5 21.5

Cucumber FL 2.0 28.0 

### 27.5 25.8 25.0 24.7 10.5 6.2 21.8 21.9

Corn PA 6. 0 24.5 

### 24.2 23.1 21.7 22.0 11.4 6.3 20.9 20.8

Tobacco NC 6.0 20.5 

### 20.2 19.0 17.0 15.8 10.0 3.6 14.0 14.6

Sweet
pota to NC 3.9 17.7 

### 17.5 16.5 14.7 13.5 7.2 4.7 10.9 10.9

Potato ID 12.0 13.2 

### 13.0 12.2 10.8 10.0 5.4 3.9 7.8 7.8

Mint OR 6. 0 6.0 

### 5.9 5.6 4.9 4.6 2.6 2.0 3.7 3.7

Hop OR 3.0 4.9 

### 4.8 4.5 4.1 3.8 2.4 1.3 3.3 3.3

Values are those estimated to be exceeded on average once every 10 years for the specified exposure designation PW_pk = Pore water peak exposure estimate.
PW_21 = Pore water 21

- day exposure estimate.



### SWCC model inputs for ethoprop follow those listed in Table 3 , more information on model inputs and outputs is provided in “ Appendix C: Aquatic Exposure Modeling selected Input and Output ”. Note that the EECs provided reflect standard assumptions for drift from ground

### 33 application for low

- boom application (except for the sugarcane scenarios) 10 

### ; sugarcane applications are all buried at a specified depth for the 20% gr anular formulation (EPA Registration # 5481

- 9042 )

, which is a specific label for the sugarcane use only . All scenarios were run with both assumptions of no drift and the EFED default assumption of 1% drift for the standard farm pond from ground application s (potentially applicable to the uses of ethoprop EC formulations). Adding a drift assumption increased the EECs for each scenario by less than 5%. For all crops a single application at the maximum label rate was assumed to be applied one day before emerge nce.

Comparison of Aquatic Exposure Estimates with Monitoring Data

Target ed retrospective ground and surface water monitoring studies have been submitted by the registrant and have been previously reviewed (see ethoprop (DP Barcodes 323344; 335734; 295045; 295035; Memorandum dated 12/18/2007). The focus of both of the groundwater and surface water surveys was vulnerable drinking water supplies so the sampled water does not represent the most vulnerable waters for ecological exposure to many organisms

. The highest surface water supply acute concentration was 0.22 ppb and the highest chronic (in terms of annual mean concentrations) was 0.018 ppb. The surface water results are further summarized in

Table 7 and Table 8 ; see DP Barcode 323344 for additional details. Since these monitoring data do not represent the most vulnerable streams for ecological risk assessment, they were not used

in the risk assessment. In the USGS National Water Quality assessment (NAWQA) monit oring

program
, ethoprop has been detected at up to 5.8 ppb (from Zollner Creek in the Willamette Basin of Oregon ).

Table 7

. 

### Representative hydrologic characteristics, estimated ethoprop usage intensity, and ethoprop

detection rat es in monitored community water systems ( CWS )

.

Watershed

ID Watershed

Area (acres) % C & D hydrologic Runoff Depth,

in. % Ethp.

- Crops Ethoprop

lb / ws *

Acre %

Parent

> 3
ppt % SME

Detects > 4 ppt

Jefferson,

OR 1,141,478 

### 49.3 0.10 0.5 0.0059 0.00 2.90

Ontario, OR 37,686,339 

### 59.4 0.05 1.3 0.0032 0.00 1.45

Lodi, CA 1,320,278 

### 59.8 0.33 0.3 0.0009 0.00 0.00

Franklin, LA 1,304,097 

### 66.3 2.18 3.1 0.0097 0.81 57.26
Wilson, NC 150,166 

### 27.1 0.54 5.8 0.0077 2.90 5.80

* ws = watershed

Source: MRID 48983801 . 2006. Surface Water Monitoring for Residues of Ethoprophos in High Use Areas in the United States, Amended Report.

10 Currently, the SWCC User Manual (USEPA/OPP 734F14001; 7/1/2014) states that a drift fraction of 0.01 is typical for ground sp ray applications. A more detailed

guidance document now approved in EFED (see Memorandum “Guidance on Modeling Offsite Deposition of Pesticides via Spray Drift for Ecological an d Drinking

Water Assessments” 12/20/2014). In the December 2013 guidance a 0.011 spray drift fraction is recommended for low boom applications with a fine to medium

/coarse drop size distribution from the nozzles. Given the nature of the restrictions on the ethoprop EC labels, a 1% drift a ssumption is still considered to be

conservative for ethoprop aquatic exposure modeling.

### 34 Table 8

. Raw water ethoprop and SME detection rates and maximum observed

concentrations for the five monitored CWS.

Watershed Ethoprop

detection rate SME Degradate

Detection Rate Ethoprop Maximum , ppt SME Maximum, ppt

Jefferson, OR 0.00% 0.00% 0.0 2.9

Ontario, OR 0.00% 1.45% 0.0 6.7

Lodi, CA 0.00% 0.00% 0.0 0.0

Franklin, LA 0.81% 57.26% 14.4 202.0

Wilson, NC 2.90% 5.80% 12.4 11.8

Concentrations are ng/L or parts per trillion.

SME = O

- ethyl

- S

- methyl

- S

- propylphosphorodithioate ; See table of parent and degradate

structures in Appendix A. Source: MRID 48983801. 2006. Surface Water Monitoring for Residues of Ethoprophos in High Use Areas in the United States, Amended Report.



### Measures of Terrestrial Exposure

T errestrial R esidue Ex posure Model (T

- REX)

Terrestrial wildlife exposure estimates are typically calculated for birds and mammals by emphasizing the dietary exposure route of uptake of pesticide active ingredients. These

exposures for birds are considered to be surrogates for exposures to terrestr ial

- phase amphibians and reptiles. For exposures to terrestrial organisms, such as birds and mammals, pesticide residues on food items are estimated based on the assumption that organisms are exposed to pesticide residues as a function of the pesticide us e pattern. Ethoprop is predominantly applied with ground incorporation methods reducing exposure to terrestrial taxa relative to foliar application. In order to estimate risk for granular or ground incorporated formulations

, T

- REX (v. 1.5.2 ; 03/22/2012 ) i s able to calculate the LD 50 

### ft

- 2 

### risk index values for the labeled uses. The assumed incorporation of these methods of application is 85 %. Thus 1 5 % of the chemical is assumed to be available for consumption by both avian and mammalian taxa. The LD 50 

### ft

- 2 

### value is calculated using a toxicity value (adjusted LD 50 

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

- 2 

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

- of

- concern (LOCs). Consideration is given to different types of feeding strategies for mammals, including herbivores , insectivores and granivores. Dose

based exposures are estimated for three weight classes of birds (20 g, 100 g, and 1000 g) and three weight classes of mammals (15 g, 35 g, and 1000 g). The input parameters for the model are given in Table 9 and calcul ated EECs are given in Table 10

, Table 1 1 , and Table 1 2

.

### 35 Table 9

. Input parameters for the T

- REX model for different uses for ethoprop

.

Input Parameters Value Source

Single Application Rate (lb a.i./A) 

### Cucurbits (cucumbers) 1.95

Product

labels 

### hops, nursery stock, sugar beets 3

sweet potato 3.9

sugarcane 4

sugarcane 4

cabbage 5.1

corn (field or sweet) 6

mint 6

tobacco 6

succulent (lima) beans 8.1

potatoes (East of the Mississippi) 9

potatoes (West of the Mississippi) 12

All Uses: 1 Product

labels Number of Applications (Interval between Applications, days)

Avian Oral LD 50 4.21 mg/kg

- bw (red winged blackbird, 63.6 g)

Avian Dietary LC 50 33 mg/kg

- diet (bobwhite)

Avian Repro NOEAC 0.95 ppm (bobwhite)

Mammal LD 50 32.8 mg/kg

- bw (rat)

Mammal NOAEC 2.3 mg/kg

- diet (rat)

1 The foliar half

- life did not influence the prediction of the terrestrial EECs for ethoprop because only one application of ethoprop is allowed per season, and thus the peak concentration occurs immediately after this single application before any dissipation occurs.

Bolded values indicate labels allow application of EC formulations

### 36 Table 10

. Avian dose

- based ethoprop EECs (mg/kg

- bw) for three size classes of birds.

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

Use (application

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

Hops, Nursery Stock, Sugar

Beets (3) 1066 489 600 67 418 15 608 279 342 38 238 8 272 125 153 17 107 4

Sweet Potato (3.9) 1093 501 615 68 428 15 623 286 351 39 244 9 279 128 157 17 109 4

Mint (6) 1640 752 923 103 642 23 935 429 526 58 366 13 419 192 236 26 164 6

Potatoes (East of the Mississippi) (9) 2460 1128 1384 154 964 34 1403 643 789 88 549 19 628 288 353 39 246 9

Potatoes (West of Mississippi) (12) 3280 1503 1845 205 1285 46 1870 857 1052 117 733 26 837 384 471 52 328 12



### Table 11

. Mammalian dose

- based ethoprop EECs (mg/kg

- bw) for three size classes of mammals.

### 37 15 gram "Small" Mammal 35 gram "Medium" Mammal 1000 gram "Large" Mammal

Use (application

rate lbs a.i./A)Short GrassTallGrassBroadleaf PlantsFruits/podsArthropodsSeedsShort GrassTall GrassBroadleaf PlantsFruits/podsArthropodsSeedsShort GrassTall GrassBroadleaf PlantsFruits/podsArthropodsSeeds

Hops, Nursery Stock, Sugar

Beets (3) 892 409 502 56 350 12 617 283 347 39 242 9 143 66 80 9 56 2

Sweet Potato (3.9) 915 420 515 57 358 13 633 290 356 40 248 9 147 67 83 9 57 2

Mint (6) 1373 629 772 86 538 19 949 435 534 59 372 13 220 101 124 14 86 3

Potatoes (East of the Mississippi) (9) 2059 944 1158 129 807 29 1423 652 801 89 557 20 330 151 186 21 129 5

Potatoes (West of Mississippi) (12) 2746 1259 1545 172 1075 38 1898 870 1067 119 743 26 440 202 248 28 172 6

### 38 Table 12

. Dietary based EECs (ppm) for application rates of ethoprop.

Use (application

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

Hops, Nursery

Stock, Sugar Beets (3) 936 429 527 59 367

Sweet Potato (3.9) 960 440 540 60 376

Mint (6) 1440 660 810 90 564

Potatoes (East of the Mississippi) (9) 2160 990 1215 135 846

Potatoes (West of Mississippi) (12) 2880 1320 1620 180 1128

### 39 Runoff and Spray Drift to Terrestrial and Semi

- Aquatic Plants

Exposure of non

- target terrestrial and semi

- aquatic (wetland) plant species is estimated using the TerrPlant (v. 1.2.2) model (release date: December 26, 2006)

. There were not any data available

for terrestrial plants so TerrPlant was not used in this assessment.

Screen ing Tool for Inhalation Risk (STIR v. 1.0)

The S creening T ool for I nhalation R isk (STIR v.1.0, November 19, 2010) was used to calculate an upper bound estimate of exposure using ethoprop ’s vapor pressure and molecular weight for vapor phase exposure as well as the maximum application rate and method of application for spray drift. STIR incorporates results from several toxicity studies including acute oral and

inhalation rat toxi city endpoints obtained from the “six

- pack” of core studies, which are a series of six guideline studies (including acute oral, acute inhalation, acute dermal contact, and others) that are submitted to the Registration Division of the Office of Pesticide P rograms for technical and formulated products of a pesticide ( rat oral LD 50 

### = 32.8 mg/kg bw , MRID 00078035 ; and

rat inh a lation LC 50 

### 0.123 mg/L, MRID 00 070060 , respectively) as well as the most sensitive acute oral avian toxicity endpoint ( house sparrow, R ed winged blackbird, or the ring

- necked pheasant (all LD 50 

### 4.21 mg/kg bw ) , MRID 40378401

, 40378401 respectively) . Based on the

results of the STIR model ( Appendix E ) , exposure through inhalation of spray drift or the vapor phase of ethoprop was not determined to be a potential pathway of concern for either avian or mammalian species on an acute exposure basis. The analysis of the inhalation route in STIR

does not include aggregation with other exposure pathways

, such as dietary, dermal, or drinking

water , which may contribute to a total exposure that has a potential for effects to non

- target animals. However, the Agency does consider the relative importance of other routes of exposure in situations where data indicate that pesticide exposures throug h other routes may be potentially significant contributors to wildlife risk (USEPA 2004). The risk characterization section ( Section

4.3 ), includes a discussion of the impact of consideration of other routes of exposure that have been identified as potenti ally important and the degree of certainty associated with screening

level risk assessment conclusions. Detailed information about STIR v.1.0, as well as the tool, can be found on EPA’s website ( http://www.epa.gov/pesticides/science/models_pg.htm#terrestrial ).

### 40 

## Effects Characterization

Measures of effect are obtained from a suite of registrant

- submitted guideline studies which were conducted with a limited number of surrogate test species described in previous assessments. The test species are not intended to be representative of the mo st sensitive species but rather were selected based on their ability to thrive under laboratory conditions. Toxicity testing reported in this risk assessment utilizes surrogate species to represent all freshwater fish (2000+)

and bir d (680+) species in the U.S. T he ECOTOXicology database (ECOTOX), was searched in

Ma rch 2013 to identify whether additional, more sensitive ecological effects data were available

for ethoprop ; however, no more useful data were identified ( USEPA 20 1 3)

.

The end points for acute and measures of effect used in this screening

- level assessment are

describ ed in Appendix B. There was one new study submitted for avian reproduction that yielded a No Observable Effects Concentration that was not included in the p revious assessments

and risk characterizations.



## Aquatic Toxicity

Table 1 3 represents aquatic toxicity endpoints for ethoprop ( EFED RED Chapter for Ethoprop, 1998). For more information on the submitted studies please reference the previous EFED

RED chapter (EPA 1998).

The only change since that assessment was the fish full life cycle test with sheepshead minnow (MRID 46315401) was upgraded from invalid to supplemental and is used as a toxicity endpoint in determining chronic risk quotients in this a ssessment. In this study, fertilized eggs (>24 to <48 hours old) were exposed to the test material at mean

- measured concentrations were <0.22 (control), 1.2, 2.0, 3.7, 7.4, and 15 ppb a.i., respectively. The endpoints affected were weight of 4 week old F 1 minnows with a 32 % reduction in weight at 3.7 μg a.i/L

.

There were no sediment studies submitted for ethoprop for either freshwater or

estuarine/marine environments.

Table 13

. Acute and chronic Toxicity endpoints for ethoprop

.

Acute Freshwater Fish Tests

Species Study Type Test

Substance

(Purity) LC 50

Toxicity Classification (MRID) (μg a.i/L) 1,2,3

(95% CL;

slope)

Bluegill sunfish ( Lepomis

macrochirus ) 96

- hr,

flow

through TGAI (99.7%) 300 Highly toxic (00160187)

, Acceptable

### 41 (230

- 400;

N/A)

Goldfish ( Carassius aruratus) 96

- hr,

flow

through Technical 13600

Slightly toxic 00780427)

(N/A; N/A)

Rainbow trout ( Salmo gairdneri ) 96

- hr,

flow

through TGAI (92%) 1020 Moderately toxic (GS0106001)

, Supplemental (N/A; N/A)

Rainbow trout ( Salmo gairdneri ) 96

- hr,

flow

through TGAI (92%) 1850 Moderately toxic (ZUOETHO1)

(N/A; N/A)

Rainbow trout ( Salmo gairdneri ) 96

- hr,

flow

through Technical 13800

Slightly toxic (0072042) (N/A; N/A)

Bluegill sunfish ( Lepomis

macrochirus ) 96

- hr,

flow

through Technical 2070 Moderately toxic (0078042) (N/A; N/A)

Rainbow trout ( Salmo gairdneri ) 96

- hr,

flow

through TGAI (92%) 1150

Highly to moderately toxic (40378201) (425

- 3000; N/A)



### Chronic Freshwater Fish Tests

Species Study Type Test

Substance

(Purity) NOAEC; Endpoints

LOAEC (MRID)

(μg a.i/L) 1,2

Fathead minnow

Pimephales promelas 32

- d Early

Life Stage Not specified 24; 54 Growth

40650102 , Supplemental



### Acute Freshwater Invertebrate Tests

EC 50

### 42 Study Type Test

Substance

(Purity) (μg a.i/L) 1,2 Toxicity Classification (MRID) (95% CL;

slope)

Water flea (Daphnia magna) 48

- hr,

static TGAI (99.7%) 93 Very Highly toxic (00160188) , Acceptable (56

- 180)

48

- hr,

flow

through TGAI (96.8%) 42.3 Very highly toxic

(31.1

- 51.7; 4.9) (00068325) , Acceptable



### Chronic Freshwater Invertebrate Tests

Species Study Type Test

Substance

(Purity) NOAEC;

LOAEC Endpoints

(μg a.i/L) 1,2 (MRID)

Water flea 21

- day

Life Cycle TGAI (96.8%) 0.8; 2.4 Length (438774

- 01)

, Acceptable

( Daphnia

magna )

Water flea

21

- day

Life Cycle TGAI (96.8%) 2.4; 5.4 Supplemental/Reproduction (406501

- 01) ( Daphnia

magna )



### Acute Estuarine/Marine Fish Tests

Species Study Type Test

Substance

(Purity) EC 50

Toxicity Classification (MRID) (μg a.i/L) 1,2,3

(95% CL;

slope)

Sheepshead

minnow ( Cyprinodon variegatus ) 96

- hour,

flow

through TGAI (96.8%) 958

Highly toxic, survival (436863

- 01) , Acceptable (761

– 1145; 0.34)

Sheepshead

minnow ( Cyprinodon variegatus ) 96

- hour,

flow

through TGAI (95%) 180 Highly toxic, survival

00066341 ) Supplemental (85

- 390;

NA)

Pinfish ( Lagodon

rhomboides ) 96

- hour,

flow

through TGAI (95%) 6.3 Very h ighly toxic, survival (40228401), Acceptable (4.8

- 8.4;

NA)

740

### 43 Sheepshead

minnow ( Cyprinodon variegatus ) 96

- hour,

flow

through TGAI (96.8%) (505

- 1070; NA) Highly toxic, survival ( 00066341 ) , Supplemental

Spot ( Leiostomus

xanthurus ) 96

- hour,

flow

through TGAI (95%) 33 Very highly toxic, survival (40228401) , Supplemental (0

- 48; NA)



### Chronic Estuarine/Marine Fish Tests

Species Study Type Test

Substance

(Purity) NOAEC;

LOAEC Endpoints

(μg a.i/L) 1,2 (MRID)

Sheepshead

minnow ( Cyprinodon variegatus ) 29

- d Early

Life Stage TGAI (96.8%) 5.9; 11 Length, Wet Weight (444721

- 01) , Acceptable

Sheepshead

minnow ( Cyprinodon variegatus ) 29

- d Early

Life Stage TGAI (95%) 12;21 Mortality of embryos and juveniles ( 00066341 )

, Supplemental

Sheepshead

minnow ( Cyprinodon variegatus ) Full life cycle TGAI (94.8%) 2;3.7 Growth (46315401)

, Supplemental



### Acute Estuarine/Marine Invertebrate Tests

Species Study Type Test

Substance

(Purity) EC 50

Toxicity Classification (MRID) (μg a.i/L) 1,2,3

(95% CL;

slope)

Eastern oyster 96

- hour,

flow

through TGAI (98.7%) 3700 Moderately toxic (436863

- 02) Acceptable Crassostrea virginica (1100

– 1900; 5.44)

Eastern oyster 96

- hour,

flow

through TGAI (95%) 14900 Slightly toxic ( 0 0066341) Acceptable Crassostrea virginica (N/A;N/A)

Saltwater mysid 96

- hour,

flow

through TGAI (96.7%) 18.78 Very highly toxic (436863

- 03) Acceptable Americamysis

bahia (15

- 22

– 45; 16.13)

Saltwater mysid 96

- hour,

flow

through TGAI (95%) 7.5 Very highly toxic (40228401) Supplemental Americamysis

bahia (N/A;N/A)

Grass Shrimp 96

- hour,

flow

through Technical 56.4 Very highly toxic (40048779) Supplemental Palaemonetes vulgaris (N/A;N/A)

### 44 Fiddler Crab 96

- hour,

flow

through Technical 1600 Moderately toxic (40048779) Supplemental Uce pugilator (N/A;N/A)

White Shrimp 96

- hour,

flow

through TGAI (95%) 6.4 Very highly toxic (40228401) supplemental Penaeus stylirostris (N/A;N/A)

Sand Shrimp 96

- hour,

flow

through TGAI (98.9%) <1000 Highly toxic (00092111) supplemental Crangon septemspinosa (N/A;N/A)

Pink shrimp 96

- hour,

flow

through TGAI (95%) 13 Very highly toxic (40228401) supplemental Panaeus

duorarum (1100

– 1900; 5.44)

Blue crab 96

- hour,

flow

through TGAI (98.9%) <1000 Highly toxic (00092111) supplemental Callinectes sapidus (N/A;N/A)

Saltwater mysid 96

- hour,

flow

through TGAI (95 %) 23 Very highly toxic ( 00066341 ) Americamysis

bahia (19

- 27)



### Chronic Estuarine/Marine Invertebrate Tests

Species Study Type Test

Substance

(Purity) NOAEC;

LOAEC Endpoints

(μg a.i/L) 1,2 (MRID)

Saltwater mysid 28

- d

Life Cycle TGAI (96.8%) 1.4 ; 2.7 Growth (Male length, Dry weight) (444575

- 01)

, Acceptable Americamysis

bahia

Saltwater mysid 28

- d

Life Cycle TGAI 95.0 '%) 0.36 Growth, survival ( 00066341 ) , Supplemental Americamysis

bahia



### Aquatic Plant Tests

Species Study Type Test

Substance

(Purity) EC 50

Effect (MRID) (ug a.i./L)

(95% CL) 1,2

Marine diatom
96

- hr,

static TGAI (99.3%) 8400 (7600

- 9000) Cell density (402284

- 01) Supplemental ( 

### Skeletonema

costatum )

### 45 

## Terrestrial Toxicity

Table 1 4 represents terrestrial toxicity endpoints for ethoprop (EFED RED Chapter for Ethoprop, 1998). For more information on the submitted studies please reference the previous EFED RED chapter (EPA 1998).

At the time of the pre vious assessment, there were no chronic avian reproduction studies

available for risk assessment . Since then there were two chronic reproduction tests submitted for ethoprop for bobwhite quail (MRID 47679601) and mallard duck (MRID 48956401). In the study with bobwhite quail, birds were exposed to mean measured treatment concentrations of 0.952, 2.88, 5.67, and 11.1 mg ai/kg diet. There were no treatment

- related effects on mortality, clinical signs of toxicity, or treat ment

- related abnormalities observed at necropsy. The most sensitive endpoints were eggs set, live 3

- week embryos, hatchling survivors, and eggshell

thickness

, which showed adverse effects at all but the lowest treatment level during the exposure period. Only effects on eggshell thickness persisted during the withdrawal period, while this endpoint and the proportion of eggs set to eggs laid were impacted when t he exposure and withdrawal periods were combined for analysis. While eggshell thickness was the most sensitive reproductive endpoint, numerous other reproductive endpoints were adversely affected at the highest treatment level before and after treatment, including eggs laid, eggs set, viable embryos, live 3

- week embryos, number hatched, hatchling survivors, and the ratios of eggs set to eggs laid, live embryos to viable embryos, and number hatched to eggs laid. Reductions from control during treatment ra nged from 26 to 35% at treatment levels of 2.88, 5.67, and 11.1 mg ai/kg diet levels. Statistically significant r eductions in eggshell thickness ranged from 3% at the

2.88 mg a.i/kg

- diet treatment level to 6% at the highest treatment level

.

The study wit h mallard duck assessed fi ve month old mallard ducks over 22 weeks and administered a diet with mean measured concentrations of 0.96, 2.8, 9.5, and 37 mg ai/kg diet.

There was no treatment

- related mortality during this test. The NOAE C was 9.5 mg ai/kg die t (mean

- measured concentration) based on treatment

- related effects on adult male and female weight gain, egg shell thickness, and percentage of eggs undamaged of eggs laid. Male and female weight decreased 6% and 5% respectively at the highest treatment l evel. There was an 8% decrease in egg shell thickness at the highest treatment concentration and the percentage of eggs damaged per eggs laid increased by 70% over the controls.

There are no terrestrial plant studies available for ethoprop. Ethoprop is an organophosphate nematicide/insecticide that inhibits the activity of the enzyme acet yl ocholinesterase causing toxicity in invertebrates and vertebrates and is not presumed to be toxic to plants.



## Terrestrial Toxicity Assessment

Table 14 . Terrestrial toxicity endpoints for ethoprop.

### 46 Acute and Sub

- acute Toxicity in Birds

Species Study Type Test

Substance

(Purity) LD 50 (mg/kg bw)

or LC 50 (mg/kg diet);

(95% CI; slope) 1,2 Toxicity

Classification (MRID) Acceptability

Coturnix quail ( Colinus virginianus ) Acute oral toxicity TGAI (95.8%) 7.5 Highly toxic ( 40378401 ) Supplemental

Rock dove ( Columba

livia) Acute oral toxicity TGAI (95.8%) 13.3 Highly toxic Supplemental

( 40378401 )

Mallard duck ( Anas platyrhynchos ) Acute oral toxicity TGAI (95.8%) 12.6 Highly toxic (50083963) Acceptable

12.6 (10.6

- 15) Highly toxic (05008363) Supplemental

61 (47

- 79) Highly toxic (05008363) Acceptable

House Sparrow ( Passer

domesticus ) Acute oral toxicity TGAI (95.8%) 4.21 Very Highly

Toxic ( 40378401 ) Supplemental

Red

- Winged

blackbird ( Agelaius phoeniceus) Acute oral toxicity TGAI (95.3%) 4.21 Very Highly

Toxic ( 40378401 ) Supplemental

Starling ( Sturnus vulgaris) Acute oral toxicity TGAI (95.3%) 7.5 Very Highly

Toxic ( 40378401 ) Supplemental

Ring

- necked

Pheasant ( Phaianus

colchicus ) Acute oral toxicity TGAI (95.8%) 4.21 Very Highly

Toxic ( 00160000 ) Supplemental

Domestic hen ( Gallus domesticus) Acute oral toxicity technical 5.62 Very Highly

Toxic

000780838 Supplemental

Grackle ( Quiscalus quiscula) Acute oral toxicity TGAI (95.3%) 10.0 (5.62

- 17.8) Very Highly

Toxic ( 40378401 ) Supplemental

Mallard duck ( Anas platyrhynchos ) Subacute dietary toxicity TGAI (95.3%) 10

- d
: = 550 Moderately

toxic (00022923) Supplemental

### 47 Ringnecked

pheasant ( Phasianus colchicus) Subacute dietary toxicity TGAI (95.8%) 118 (103

- 134) Highly toxic (00022923) Acceptable

Bobwhite quail ( Colinus virginianus ) Subacute dietary toxicity TGAI (95.8%) 33(27

- 40) Very Highly

Toxic (00022923) Acceptable

Mallard duck ( Anas platyrhynchos ) Subacute dietary toxicity TGAI (95.8%) 5

- d LC 50 = 287 (215

- 382) Highly Toxic (00022923) Acceptable

Japanese Quail Subacute dietary toxicity TGAI (95.8%) 100 (85

- 117) Highly toxic (00022923) Supplemental

Chronic Bird Toxicity Tests

Species Study Type Test

Substance

(Purity) NOAEC;

LOAEC (mg/kg diet) Endpoints (MRID) Classification

Northern bobwhite quail

Colinus virginianus Chronic reproduction TGAI (96.2%) 0.95 ; 2.9 eggs set, live

3

- week embryos, hatchling survivors, and eggshell

thickness (47679601) Acceptable

Mallard duck ( Anas platyrhynchos ) Chronic reproduction TGAI (96.6%) 9.5 ; 37 14

- d adult

survivor weight gain,

egg shell thickness,

percentage undamaged

eggs laid (48956401) Acceptable

Acute and Chronic Mammal Toxicity Tests

Species Study Type Acute Chronic

LD 50 (mg/kg bw) Toxicity

Classification (MRID) NOAEC (mg/kg diet)

NOAEL (mg/kg bw/day) Endpoints (MRID)

Norway rat

( Rattus norvegicus ) Acute oral toxicity 14

- d LD 50 = 32.8 mg a.i/kg

bw Highly toxic (0078035) NOAEC= 30 ppm (2.3 mg/kg/day)

LOAEL = 150 ppm (13 mg/kg/day) Reproduction and Growth (419212

- 01) Supplemental

### 48 Acute Terrestrial Invertebrate Toxicity Tests

Species Study Type (TGAI or EP) Test

Substance

(Purity) LD 50 (μg a.i./bee) Toxicity

Classification (MRID) Acceptability

Honey bee ( Apis mellifera ) Acute oral

and contact

toxicity (TGAI) 2.58 (contact) Moderately

toxic Acceptable

00066220

Acute

contact toxicity (EP) 5.56 (contact) Moderately

toxic (00043714) Acceptable

Bolded values represent the lowest definitive toxicity endpoint and are used in risk estimation



## Review of Incident Data

The Ecological Incident Information System (EIIS)

, which is maintained by the Agency’s Office of Pesticide Programs, was searched to determine if ecological incidents have been reported for ethoprop. Incidents have been reported from the use of ethoprop and are in the EPA incident

database

, which was sea rched in June 2014. There are eight reported incidents with one incident reported as unlikely ( Table 1 5 ). Reported incidents involved fish, birds and plants. EFED has not received any ecological effects data to corroborate possible impacts of ethoprop on plants.

Two incidents of the 8 reported on ethoprop in the EIIS database involve effects on plants (potato). One incident with MOCAP EC and an application rate of 2 quarts/acre was an in

furrow application that affected 3535 acres of potatoes. The oth er application was as a granular formulation with an application rate of 25 lbs / Acre that affected 15.6 acres. Other plant incidents involving organophosphates have likely been caused by joint application of other herbicides. For the OP terbufos, flume tsulam, an ALS

- herbicide, was one of two herbicides applied along with terbufos. Terbufos and other OP insecticides increase the risk of plant injury in corn plants due to toxic effects of ALS

- herbicides. Similar e ffects may occur in other crops.

Terbuf os labels provide warnings about the timing of application of terbufos and ALS

- herbicides and similar recommendations may be needed for ethoprop. This interaction occurs because

terbufos and ALS

- herbicides are degraded by the same enzyme system; thus, the presence of terbufos may reduce the rate of degradation of the herbicide and allow it to accumulate in the plant to toxic levels.

Table 15

. Summary of EIIS incidents as of June 2014.

Type (Quantity) Use Site Date Legality Certainty State Route of Exposure Year

American Robin (1) N/R 1

- Jan

81 Undetermined Probable FL Ingestion 1981

### 49 Fish (400) Tobacco 9

- May

89 Registered

Use Possible NC Runoff 1989

Eel, Bass,

Mullet Turf, golf

course 3

- Aug

92 Registered

Use Probable SC Runoff 1992

Unknown

fish Turf, golf

course 12

- Apr

94 Undetermined Probable LA Runoff 1994

Shad (200) Turf, golf

course 3

- Aug

94 Registered

use Probable LA Runoff 1994

Canada goose (3) N/R 9

- Sep

96 Undetermined Highly

Probable GA Ingestion 1996

Potato (3535 acres) Potato 19

- Jun

03 Registered

use Probable NE Holt 2003

Potato (15.8 acres) Potato 17

- Aug

03 Misuse (accidental) Probable ME Aroostook 2003



### Four of the incidents involved registered uses, two incidents resulted from misuse of ethoprop and two incidents were of undetermined uses. Three of the eight incidents also correlated with excess rainfall promoting runoff of both granular and EC formulat ions. Unfortunately the database does not indicate how soon the fish were killed after ethoprop was applied. It is reasonable to assume that the concentrations of ethoprop that caused the kills were higher than those eventually measured at the sites. Fish kills at golf course sites are generally easier to document than in flowing open water systems which are typical of estuaries, due to the ease of close, oftentimes daily, monitoring. Recurring fish kills, even though these kills may not significantly redu ce fish populations as a whole or even locally, may still

, in themselves , be

considered an adverse effect. There have not been any incidents reported other than with plants

since the last assessment.

The American Bird Conservancy (ABC) Avian Incident Mon itoring System (AIMS) was searched in June 2014 and returned three records of incidents associated with ethoprop totaling 510 bird mortalities (ABC, 2014). The AIMS incidents seem to confirm claims that other incidents have occurred involving waterfowl, u pland game birds, and songbirds (Stone, 1980).

A June 2014 search of the Incident Database System (IDS)

, maintained by OPP’s Information Technology and Resource Management Division (ITRMD)

, yielded one incident for ethoprop involving wildlife. This incident was associated with Chipco Mocap Brand 10G granular

formulation (no longer registered) and was classified as minor.

A lack of reported incidents does not necessarily mean that such inc idents have not occurred. In addition, incident reports for non

- target plants and animals typically provide information on mortality events only. Reports for other adverse effects, such as reduced growth or impaired reproduction, are rarely received.

### 50 

## R isk Characterization and Description

The exposure and toxicity effects data are integrated in order to evaluate the risks of adverse ecological effects on non

- target species. For the risk assessment of ethoprop, the risk quotient (RQ) method is used to c ompare estimated exposure and measured toxicity values. The RQ method involves dividing EECs by point estimates of the most sensitive acute and chronic toxicity values. The resulting RQs are then compared to the Agency’s Levels of Concern (LOC) (USEPA 20 04). These criteria are used to indicate when applications of ethoprop, as directed on the label, have the potential to cause adverse effects to non

- target organisms.



## Risk Estimation and Description

Non

- target Aquatic Animals and Plants

Freshwater and Estuarine/Marine Fish

Ethoprop was classified as highly toxic to freshwater fish with a LC 50 

### of 300 ug a.i./L (MRID 00160187) and very highly toxic to estuarine/marine fish with and LC 50 

### of 6.3 ug a.i./L (MRID R2043487). Both freshwater and estuarine/mar ine fish demonstrated sensitivity to ethoprop on a chronic basis as well with a NOAEC of 24 (MRID 40650102) and 2 ug a.i. /L (MRID 46305401), respectively. For freshwater fish, the acute RQs for freshwater fish exceeded the acute listed species LOC in 9 o f 16 scenarios and the chronic RQs exceeded the chronic LOC in

10 of the 16 scenarios ( Table 1 6 )

. The acute RQs for freshwater fish ranged from 0.02 to 0.47 and the chronic RQs ranged from 0.17 to 4.83 . For estuarine/marine fish both the acute and chronic RQs exceeded the LOCs in all 16 scenarios modeled. Estuarine/marine fish were markedly more sensitive to ethoprop than freshwater fish as indicated by acute RQs that ranged

from 0.77 (greater than th e non

- listed species LOC of 0.5 ) to 22.38. The chronic RQs for ranged

from 2.05 to 58 ( Table 1 6 )

. Both the acute and chronic RQs of freshwater and estuarine/marine fish suggest there is both acute and chronic risk concern over a broad range of uses of et hoprop.

While t he models have changed to generate environmenta l exposure since the last assessment,

the conclusions of acute and chronic risk to freshwater and estuarine/marine fish remain largely

the same. Risk to aquatic fish is also reflected in the 5 fish kill incidents involving ethoprop

. The likelihood that ethoprop was responsible for the remaining three incidents, two from registered uses and a third incident that where the use was unspecified, were listed as probable in the EIIS report.

The likelihood of adverse effects on aquatic organisms is increased by the fact that ethoprop can contaminate surface water via runoff for up to several months after application. Ethoprop will

enter surface waters in both the dissolved form as well as boun d to suspended and eroding materials as suggested by its water solubility and its partitioning, respectively. It appears that ethoprop can be persistent in surface water especially in water with low to moderate microbial activity and moderate acidity (les s hydrolysis, see Figure 2 ) or where abundant alternative energy

### 51 (carbon) sources are not available. In waters with short hydrological residence times (streams

and ri vers), its persistence is limited by the flow out of the system more so than by metabolism

.

Table 16 . Acute and chronic risk quotients for freshwater and estuarine/marine fish.

Peak

EECs (ppb) 60

- day

Chronic

EECs (ppb) FW Fish 60day SW Fish 60day

State Crop Acute

RQ Chronic

RQ Acute

RQ Chronic RQ

MS corn 141 116 0.5 4.8 22.4 58.0

FL Sugarcane 58.1 49.6 0.2 2.1 9.2 24.8

IL Corn 47.1 39.8 0.2 1.7 7.5 19.9

LA Sugarcane 47 40.8 0.2 1.7 7.5 20.4

OH Corn 42.3 36.7 0.1 1.5 6.7 18.4

FL Cabbage 42.16 36.125 0.1 1.5 6.7 18.1

NC Corn 33.5 27.7 0.1 1.2 5.3 13.9

ME Potato 32.55 28.35 0.1 1.2 5.2 14.2

OR Snap

beans 32.13 26.865 0.1 1.1 5.1 13.4

FL Cucumber 27.95 24.96 0.1 1.0 4.4 12.5

PA Corn 24.5 21.7 0.1 0.9 3.9 10.9

NC Tobacco 20.5 17 0.1 0.7 3.3 8.5

NC Sweet

potato 17.745 14.69 0.1 0.6 2.8 7.3

ID Potato 13.18 10.84 0.04 0.5 2.1 5.4

OR Mint 6.02 4.94 0.02 0.2 1.0 2.5

OR Hop 4.86 4.095 0.02 0.2 0.8 2.0
Bolded values represent LOC exceedances.



### Freshwater and Estuarine/Marine Invertebrates

Ethoprop was classified as very highly toxic to freshwater invertebrates with a LC 50 

### of 42.3 ug a.i./L (MRID 00068325) and very highly toxic to estuarine/marine invertebrates with and LC 50 

### of 18.78 ug a.i./L (MRID 43686303 ). Both freshwater and estuarine/marine invertebrates demonstrated sensitivity to ethoprop on a chronic basis as well with a NOAEC of 0.8 (MRID

4 43877401 ) and 0.36 ug a.i. /L (MRID 00066341 ), respectively. For freshwater invertebrates

, the acute RQs exce eded the acute listed species LOC in all 16 scenarios and acute non

- listed LOC (0.5) in 1 2 of 16 scenarios ( Table 1 7 ) . The acute RQs ranged from 0. 1 to 3.3 . The

freshwater invertebrates c hronic RQs also exceeded the LOC in all 16 scenarios ranging from 3 4

### 52 to 361 . For estuarine/marine invertebrates both the acute and chronic RQs exceeded the LOCs in

all 16 scenarios modeled. Estuarine/marine invertebrates acute RQs that ranged from 0.3 to 7.5 with 14 of 16 scenarios exceeding the non

- listed species LOC a nd all scenarios exceeding the listed species LOC. The chronic RQs for estuarine/marine invertebrates for ranged from 5.7 to
16 3 ( Table 1 7 ) . Both the acute and chronic RQs of freshwater and estuarine/marine

invertebrates suggest there is both acute and c hronic risk concern over a broad range of uses of ethoprop. While the modeling h as been refined since the last assessment, the conclusions of

acute and chronic risk to freshwater and estuarine/marine invertebrates remain largely the same.

Environment s that promote higher EECs, such as in water bodies with high residenc e times like

those coastal regions with low tidal cycles (i.e. estuarine ecosystems where ethoprop is frequently used like Florida) will be particularly at risk.

Table 17

. 

### Acute and chronic risk quotients for freshwater and estuarine/marine invertebrates.

Peak

EECs (ppb) 21

- day

Chronic

EECs (ppb) FW

Invert 21 day SW

Invert 21 day

State Crop Acute

RQ Chronic

RQ Acute

RQ Chronic

RQ

MS corn 141 130 3.3 361.1 7.5 162.5

FL Sugarcane 58.1 53.7 1.4 149.2 3.1 67.1

IL Corn 47.1 44.2 1.1 122.8 2.5 55.3

LA Sugarcane 47 44.8 1.1 124.4 2.5 56.0

OH Corn 42.3 40.9 1.0 113.6 2.3 51.1

FL Cabbage 42.16 39.525 1.0 109.8 2.2 49.4

NC Corn 33.5 31.1 0.8 86.4 1.8 38.9

ME Potato 32.55 30.75 0.8 85.4 1.7 38.4

OR Snap

beans 32.13 30.105 0.8 83.6 1.7 37.6

FL Cucumber 27.95 25.7725 0.7 71.6 1.5 32.2

PA Corn 24.5 23.1 0.6 64.2 1.3 28.9

NC Tobacco 20.5 19 0.5 52.8 1.1 23.8

NC Sweet

potato 17.745 16.51 0.4 45.9 0.9 20.6

ID Potato 13.18 12.24 0.3 34.0 0.7 15.3

OR Mint 6.02 5.59 0.1 15.5 0.3 7.0

OR Hop 4.86 4.53 0.1 12.6 0.3 5.7
Bolded values represent LOC exceedances.



### Benthic Invertebrates

Ethoprop is highly persistent in water and is capable of reaching water bodies. Modeled pore

water values were between 62% and 73% the modeled surface water values and water column

### 53 exchange with pore waters suggest that benthic invertebrates would be exposed to ethoprop even if the chemical does not partition strongly to the sediment.

Per the recent sediment toxicity guidance, acute and chronic risk to benthic invertebrates can be estimated in several ways depending on the availability of data. Due to lack of sediment data for ethop ro p, acute RQs were based on the peak pore water c oncentration compared to the most

sensitive water column EC or LC 50 

### presented in the water column invertebrate section above. Chronic RQs were estimated by comparing the 21

- day pore water EEC to the most sensitive

water column NOAEC presented in the water column invertebrate section above

.

Acute RQs ranged from 0.1 to 2.0 for freshwater sediment invertebrates and 0.2 to 4.5 for estuarine/marine sediment invertebrates and exceeded the acute listed species LOC (0. 05 ) in all

scenarios for both ( Table 1 8 )

. Chronic RQs exceeded the chronic LOCs as well and ranged from

9.3 to 23 8 for freshwater invertebrates and from 4.6 to 10 7 ( Table 1 8 ) . Both the acute and chronic RQs of freshwater and estuarine/marine sediment dwelling invertebrates suggest there is

both acute and chronic risk concern over a broad range of uses of ethoprop. While there is uncertainty in these estimates due to lack of data, it highlights the risk to multiple compartments within the water column should ethoprop enter water ways.

Table 18

. Acute and chronic risk quotients for freshwater and estuarine/marine sediment dwelling invertebrates estimated from water column EC50/NOAEC and pore water concentrations (peak and 21

- day)

.



### 4

- day

Sediment

Peak

EECs (ppb) 21

- day

Chronic

Sediment

EECs (ppb) FW Sed Invert SW Invert

State Crop Acute

RQ Chronic

RQ Acute

RQ Chronic

RQ

MS corn 85.3 85.5 2 237.5 4.5 106.9

FL Sugarcane 36.7 36.6 0.9 101.7 2 45.8

IL Corn 37.9 39.6 0.9 110 2 49.5

LA Sugarcane 28.3 28.2 0.7 78.3 1.5 35.3

OH Corn 26 26.1 0.6 72.5 1.4 32.6

FL Cabbage 26.1 25.9 0.6 72 1.4 32.4

NC Corn 21.1 21 0.5 58.3 1.1 26.3

ME Potato 27 27.9 0.6 77.5 1.4 34.9

OR Snap

beans 21.5 21.5 0.5 59.6 1.1 26.8

FL Cucumber 21.8 21.9 0.5 60.9 1.2 27.4

PA Corn 20.9 20.8 0.5 57.8 1.1 26

### 54 NC Tobacco 14 14.6 0.3 40.6 0.7 18.3

NC Sweet

potato 10.9 10.9 0.3 30.3 0.6 13.7

ID Potato 7.8 7.8 0.2 21.7 0.4 9.8

OR Mint 3.7 3.7 0.1 10.2 0.2 4.6

OR Hop 3.3 3.3 0.1 9.3 0.2 4.2

Bolded values represent LOC exceedances.



### Aquatic Plants

There were not any LOC exceedances for aquatic plants based on the one study that was

available for the saltwater diatom. There was not any data available for additional non

- vascular plants or vascular plants. While there is uncertainty due to lack of a dditional data, t h e lack of

exceedances is consistent with the mode of action of ethoprop that is not anticipated to affect plants.

Non

- target Terrestrial Animals and Plants

Ethoprop has granular applications. The LD 50 

### /ft 2 

### value is used to estimate risk for granular

formulations and row, banded, and in

- furrow applications. Conceptually, an LD 50 

### ft

- 2 

### is the amount of a pesticide estimated to kill 50% of exposed animals in each square foot of applied area. Although a square foot does not have defined ecological relevance, and any unit area could be used, risk presumably increases as the LD 50 

### /ft 2 

### value increases. The LD 50 

### ft

- 2 

### value is calculated using a toxicity value (adjusted LD 50 

### ) and the EEC (mg ai. ft

- 2 

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

- of

- concern (LOCs). The LD 50 

### /ft 2 

### was calculated assuming 85 percent incorporation since labels specify that ethoprop granules need to be incorporated

. LOCs were exceeded for every proposed use of ethoprop for both birds and mammals. For birds,

the LD 50 

### /ft 2 

### exceeded the acute non

- listed LOC and ranged from 0.5 for large birds (1000 g) at the lowest application rate to 264.8 for small birds (20g) at the highest application rate. For mammals, the LD 50 

### /ft 2 ranged from 0.1 f or large mammals (1000g) at the lowest application rate

to 17.3 for small mammals (15g) at the highest application rate. Despite a n 85% incorporation, current uses of ethoprop result in risk to both birds and mammals for all proposed granular uses.

The r esults are consistent with the conclusions from previous risk assessments for ethoprop ( Table 19 )

.

Table 19 LD 50 ft

- 2 risk quotients from granular and incorporated applications of ethoprop.

LD 50 ft 2 Analysis (85% incorporation)

Use (application rate lbs a.i./A) Avian Mammal

20 g 100 g 1000 g 15 g 35 g 1000 g

Cucurbits (1.95) 43.0 6.8 0.5 2.8 1.5 0.1

### 55 Hops, Nursery Stock, Sugar Beets (3) 66.2 10.4 0.7 4.3 2.3 0.2

Sweet Potato (3.9) 86.1 13.5 1.0 5.6 3.0 0.2

Sugarcane (4) 88.3 13.9 1.0 5.8 3.1 0.2

Cabbage (5.1) 112.5 17.7 1.3 7.4 3.9 0.3

Corn, Tobacco (6) 132.4 20.8 1.5 8.7 4.6 0.4

Succulent (lima) beans (8.1) 178.7 28.1 2.0 11.7 6.2 0.5

Potatoes (East of the

Mississippi) (9) 198.6 31.2 2.2 13.0 6.9 0.6

Potatoes (West of Mississippi) (12) 264.8 41.6 2.9 17.3 9.2 0.7

### 56 EC formulations with application from boom sprayers include 3 lb a.i./A application rates on hops, sugar beets and nursery stock, 3.9/4 lbs a.i./A on s weet potatoes, and 9 and 12 lbs a.i./A on

potato . This application method may expose residual in

- field weeds and flowering plants to residues of ethoprop that may be used as forage by birds and mammals

. The lowest application rate of ethoprop resulted in LOC exceedances in almost every size class of birds and mammals from both acute and chronic exposure. There was one dietary item for chronic dietary exposure

for mammals that did not exceed the LOC at t he lowest application rate (3.0 lbs a.i./A). The RQ for mammalian chronic expos ure to seeds in the largest bird size class was 0.9 (Table 22)

. At the next lowest application rat e (3.9 lbs a.i./A), all exposures for birds and mammals exceeded the

acute and chronic LOCs.

For the lowest application rate avian dose

- based acute RQs ranged from 0. 5 for seeds in the largest avian size class to 231.7 for short grass in the smallest avian si ze class. For the highest application rate, avian dose

- based acute RQs ranged from 1.8 for seeds in the largest avian size

class to 926.7 for short grass in the smallest avian si ze class. All exposure routes at every application rate exceeded the non

- listed species acute LOC ( Table 2 0 )

. RQs for acute dietary

exposures ranged from 1.4 to 21.8 for the lowest application rates and from 5.5 t o 87.3 for the highest application rate. The RQs exceeded the non

- listed species LOC for all exposure routes at every application rate ( Table 2 1 ). RQs for avian chronic dietary exposure ex ceeded the LOC ranging from 47.3 for fruits/pods to 756.3 for shor t grass from the lowest application rates and from 189.1 to 3025.1 for the highest application rates

. For the lowest application rate

, mammalian dose

- based acute RQs ranged from 0.1 for seeds in the largest avian size class to 9.5 for short grass in the s mallest avian size class. All exposure routes exceeded the listed species

acute LOC f or the lowest application rate

. Mammalian dose

- based chronic RQs ranged from 0.9

to 135.8 and exceeded the chronic LOCs for all exposure routes except one (seeds for large mammals; Table 2 2 ) at the lowest application rate. At the highest application rate RQs ranged

from 0.2 to 38.1 for dose

- based acute exposure . Mammalian RQs for chronic dietary exposures

varied from 1.0 to 15 .7 for the lowest a pplication rates and 24.5 to 62.6 at the highest application

rates and exceeded the non

- listed species LOC for all exposure routes (Table 23 ). Analysis of terrestrial application residues indicate that residues on all dietary items would remain in concentrations that exceed the chronic toxicity endpoints for birds longer than the 105 days

that is model in T

- REX at the lowest application rates. The same is true for mammals with the exception of the fruits/pods/seeds dietary item that has residues pe rsisting for approximately 60 days before the concentration is lower than the mammalian chronic toxicity endpoints.

LOC exceedances from EC formulations are also well documented in the previous assessment (EPA 1998). If residues of ethoprop exist on diet ary items they pose significant

acute and chronic risk concern for both birds and mammals at all current application rates due to ethoprop’s high toxicity, high solubility in water and resistance to hydrolytic, photolyic and metabolic degradation in water and soil. All EC uses that have higher application rates would have higher RQs.

### 57 Table 20 . Avian dose

- based acute RQs

Small Medium Large

Use (applicat

ion rate

lbs a.i./A)Short GrassTall GrassBroadleaf PlantsFruits/podsArthropodsSeedsShort GrassTall GrassBroadleaf PlantsFruits/podsArthropodsSeedsShort GrassTall GrassBroadleaf PlantsFruits/podsArthropodsSeeds

Hops, Nursery Stock, Sugar

Beets

(3) 231

.7 106

.2 130
.3 14.
5 90.

7 3.2 103
.8 47.
6 58.

4 6.5 40.
6 1.

4 32.
9 15.

1 18.
5 2.

1 12.
9 0.
5

Sweet
potatoes

(3.9) 308

.9 141

.6 173

.8 19.

3 121

.0 4.3 138

.4 63.

4 77.
8 8.6 54.

2 1.

9 43.

9 20.

1 24.

7 2.

7 17.

2 0.

6

Potatoes

(12) 926

.7 424

.8 521

.3 57.

9 363

.0 12.

9 415

.1 190

.3 233
.5 25.

9 162

.6 5.

8 131

.6 60.

3 74.

0 8.

2 51.
5 1.

8

Acute listed species LOC = 0.1; Acute Restricted Use LOC = 0.2; Non

- listed animals acute LOC = 0.5

Table 21

. Avian dietary

- based acute and chronic RQs

.

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

Acute Hops, Nursery Stock, Sugar Beets (3) 21.8 10.0 12.3 1.4 8.5

Sweet potatoes (3.9) 29.1 13.3 16.4 1.8 11.4

Potatoes (12) 87.3 40.0 49.1 5.5 34.2

Chronic Hops, Nursery Stock, Sugar Beets (3) 756.3 346.6 425.4 47.3 296.2

Sweet potatoes (3.9) 1008.4 462.2 567.2 63.0 395.0

Potatoes (12) 3025.2 1386.6 1701.7 189.1 1184.9

Chronic LOC = 1.0

Acute LOC = 0.5

### 58

### 59 Table 22

. Mammalian dose

- based acute and chronic RQs

.

Small Medium Large

Use (application

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

Acute Hops, Nursery Stock, Sugar Beets (3) 9.5 4.4 5.4 0.6 3.7 0.1 8.1 3.7 4.6 0.5 3.2 0.1 4.4 2.0 2.5 0.3 1.7 0.1

Sweet
potatoes

(3.9) 12.7 5.8 7.1 0.8 5.0 0.2 10.8 5.0 6.1 0.7 4.2 0.2 5.8 2.7 3.3 0.4 2.3 0.1

Potatoes

(12) 38.1 17.5 21.4 2.4 14.9 0.5 32.5 14.9 18.3 2.0 12.7 0.5 17.4 8.0 9.8 1.1 6.8 0.2

Chronic Hops, Nursery Stock, Sugar Beets (3) 135.8 62.2 76.4 8.5 53.2 1.9 116.0 53.2 65.2 7.2 45.4 1.6 62.2 28.5 35.0 3.9 24.4 0.9

Sweet
potatoes

(3.9) 181.1 83.0 101.8 11.3 70.9 2.5 154.7 70.9 87.0 9.7 60.6 2.1 82.9 38.0 46.6 5.2 32.5 1.2

Potatoes

(12) 543.2 249.0 305.5 33.9 212.8 7.5 464.0 212.7 261.0 29.0 181.7 6.4 248.7 114.0 139.9 15.5 97.4 3.5

Chronic LOC = 1.0

Acute listed species LOC = 0.1; Acute Restricted Use LOC = 0.2; Non

- listed animals acute LOC = 0.5

### 60

### 61 Table 23

. Mammalian dietary

- based chronic RQs

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

Hops, Nursery Stock, Sugar Beets (3) 

### 15.7 7.2 8.8 1.0 6.1

Sweet potatoes (3.9) 

### 20.9 9.6 11.7 1.3 8.2

Potatoes (12) 

### 62.6 28.7 35.2 3.9 24.5

Chronic LOC = 1.0



### Risk Characterization and Description from e xposure to pollinators

Contact e xposure to bees is expected to be very l ow from granular applications. There is uncertainty however about exposure to ground dwelling bees that may be exposed to ground applications. The EC formulation is registered with application from boom sprayers. Drift from the boom sprayers or residues that are not incorporated into the soil would pose high risk to pollinators that may come into direct contact or contact with residues. Using calculations (2.7*Application Rate÷Toxicity = Contact RQ) from Bee

- Rex modeling within the pollinator guidance

, the RQs for contact exposure ar e 2.0 and 12.5 for the lowest (1.95 lbs a.i./A) and highest (12 lbs a.i./A) application rates respectively , both significantly exceeding the established

LOC of 0.4

. There were not any acute oral studies for adult honey bees. Ethoprop is not a systemic pest icide so exposure through this route is presumed to be low. There were also not any acute or chronic toxicity studies submitted for larval bees or chronic oral studies for adult

bees. Therefore, risks to terrestrial invertebrates is presumed, consistent w ith ethoprop ’ s mode of

action and the demonstrated toxicity in the adult bee contact studies

.

Terrestrial Plants

There is not any data on terrestrial plants so risk quotients could not be determined.

Risk description associated with consumption of earthw orms

Ethoprop is incorporated into the soil whether it is applied as a granular or emulsified concentrate formulation. The physical and chemical characteristics of ethoprop suggest that it may partition to earthworms that may be consumed by either mammal s or birds. In order to assess this possibility of pesticide exposure to terrestrial animals resulting from consumption of earthworms contaminated with pesticide mass present in the soil of the application site the EPA developed an earthworm fugacity mode l. A simple fugacity approach has been used to estimate concentrations of the pesticide in earthworms ( Table 2 4 ). This model assumes the pesticide

### 62 partitions between the soil, porewater and air within the soil and that worms are exposed to the pesticide through ingestion of the soil and birds and mammals are exposed through the ingestion of worms. The input parameters and example of the model can be found in Appendix F

. Comparison of the EECs that are generated can be compared to toxicological endpoints to provide an estimate if there is potential risk. The endpoints used in the model are presented in

Table 24

.

Table 24 . Soil EECs generated from uses of ethoprop from the earthworm fugacity model.

Earthworm EECs (g/Kg) in earthworm tissue consumed by either mammals or birds.

Use (application rate lbs a.i./A) Mammal Avian

Acute

dose

based Chronic

dose

based Chronic dietary

based Acute

dose

based Acute dietary

based Chronic dietary

based

Cucurbits (1.95) 0.05 0.05 1.16 0.42 1.16 1.16

Hops, Nursery Stock, Sugar Beets (3) 0.07 0.07 1.78 0.64 1.78 1.78

Sweet Potato (3.9) 0.09 0.09 2.31 0.84 2.31 2.31

Sugarcane (4) 0.09 0.09 2.37 0.86 2.37 2.37

Cabbage (5.1) 0.12 0.12 3.03 1.09 3.03 3.03

Corn, Mint, Tobacco (6) 0.14 0.14 3.56 1.29 3.56 3.56

Succulent (lima) beans (8.1) 0.19 0.19 4.81 1.74 4.81 4.81

Potatoes (East of the

Mississippi) (9) 0.21 0.21 5.34 1.93 5.34 5.34

Potatoes (West of Mississippi) (12) 0.28 0.28 7.12 2.57 7.12 7.12



### Table 25 . Endpoints compared to EECs in earthworms generated by the earthworm fugacity model.

Endpoint Toxicity

Value

Mammalian, acute

dose

- based 14.9 mg/kg

bw

Mammalian, chronic

dose

- based 1.0 mg/kg

- bw

### 63 Endpoint Toxicity

Value

Mammalian, chronic dietary

- based 46 mg/kg

- diet

Avian, acute, dose

based 4.21 mg/kg

bw

Avian, acute, dietary

based 33 mg/kg

- diet

Avian, chronic, dietary

based 0.95 mg/kg

diet



### Based on the EECs generated and the mammalian endpoints used in the T

- REX model, risk to mammals consuming earthworms appears to be low for a ny of the uses and application rates of ethoprop to mammals either on an acute or chronic basis. The comparison of avian toxicity endpoints with EECs for birds does suggest that birds may be at risk from both acute dose and dietary based exposure as wel l as chronic dietary exposure. The toxicity of ethoprop to avian species and the propensity of ethoprop to partition to earthworm tissues suggest that this pathway is of both acute and chronic concern for those avian taxa consuming worms in fields treated with ethoprop at all nine application rates that ethoprop is registered under

.

Risk description through i nhalation

Previous work with the organophosphate insecticides has shown that volatilization and microbial degradation increases as soil moisture cont ent and temperature increases. The field dissipation rates are likely a result of microbial degradation, leaching, runoff, plus volatilization. STIR models with ethoprop indicate that risk through inhalation is not likely a concern when comparing the rati o of droplet inhalation dose to the adjusted inhalation dose (LD50) in the STIR model. The ratio for birds and mammals was predicted to be 3. 8 X 10

- 2 

### and 6. 7 X10

- 4 

### respectively indicating exposure is not likely significant. The majority of ethoprop labels addition ally require immediate incorporation in the soil either by mechanical means or through immediate watering in of the chemical further reducing the risk through inhalation. Output of the STIR model is presented in Appendix E

.

Risk from Drift to Aquatic Ecosystems

The current EC formulation label specif ies that ethoprop should be used from a low boom with coarse droplet sizes. Table 26 presents the results of AgDrift modeling with finer droplet sizes

on the distance from the edge of the treated field whereby effects to aquatic environments would not be expected (effects distance) using the most sensitive aquatic acute endpoint (6 ug a.i./L;

MRID 00066341 )

. As an example, v ery fine to fine droplet sizes results in an effects distance

from 3 to 33 feet from aquatic waterway s and ponds

, whereas coarse droplet sizes largely reduce

### 64 the risk of drift and the effects distance in all but the highest application rat es . Under current restrictions, coarse droplet sizes from a low boom should minimize risk due to drift on neighboring aquatic ecosystems in all but the highest application rates

. . It is important to note that risk would still be present in aquatic system s from runoff as reviewed in the aquatic RQs.

The previous ecological risk assessment (EPA 1998) presents a more detailed discussion of the importance of reduc ing risk by reducing d rift

.

Table 26

. 

### Aquatic Effects Distance in feet from low boom applications

.

Application Rate (lbs a.i/A) Distance (in feet) from edge of field according to d roplet size from low boom

Very fine to fine Fine to medium/coarse

1.95 0 0

3 0 0

6 3.28 0

8 9.84 0

9 16.4 0

12 32.81 3.28



## Endocrine Disruptor Screening Program (EDSP)

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

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

- tiered approach to making the statutorily required determinations. Tier 1 consists of a battery of 11 screening assays to identify the potential of a chemical substance to interact with the estrogen, androgen, or thyroid (E, A, or T) hormonal systems. Chemicals that go through Tier 1 screening and are found to have the potential to interact with E, A, or T hormonal systems will proceed to the next stage of the EDSP where EPA will determine which, if any, of the Tier 2 tests are necessary based on the available data. Tier 2 testing is designed to identify any adverse endocrine

- related effects caused by the substance, and

establish a dose

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

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

- ins for the first group of 67 chemicals, which co ntains 58 pesticide active ingredients and 9 inert ingredients. A second list of chemicals identified for EDSP screening was published on June 14, 2013 11 

### and includes some pesticides scheduled for registration review and chemicals found in water

. Neither o f these lists should be construed as a list of known or likely endocrine disruptors.

Ethoprop is on List 1 for which EPA has received all of the required Tier 1 assay data. The Agency has reviewed all of the assay data received for the appropriate List 1 chemicals and the

conclusions of those reviews are available in the chemical

- specific public dockets (see EPA

- HQ

OPP

- 2008

- 0560 for ethoprop).

. For further information on the status of the EDSP, the policies and procedures, the lists of chemicals, future lists, the test guidelines and the Tier 1 screening battery, please visit our website. 12

11 See http://www.regulations.gov/#!documentDetail;D=EPA

- HQ

- OPPT

- 2009

- 0477

- 0074 for the final second list of chemicals.

12 http:// www.epa.gov/endo/

### 66 

## Federally Threatened and Endangered (Listed) Species of Concern

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

National Marine Fisheries Service (NMFS) (collectively, the Services), and the U.S. Department of Agriculture (USDA) released a summary of their joint Interim Approaches for assessing risks to listed species from pesticides. The Interim Approaches were developed jointly by the agencies in response to the National Academy of Sciences’ (NAS) recommendations and reflect a common approach to risk assessment shared by the agencies as a way of addressing scientific

differences between the EPA and the Services. The NAS report 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 obli gations under the Endangered Species Act (ESA) and FIFRA.

The joint Interim Approaches were released prior to a stakeholder workshop held on November 15, 2013. In addition, the EPA presented the joint Interim Approaches at the December 2013

Pesticide Pr ogram Dialogue Committee (PPDC) and State

- FIFRA Issues Research and Evaluation Group (SFIREG) meetings, and held stakeholder workshop s in April and October 2014, allowing additional opportunities for stakeholders to comment on the Interim Approaches. As p art of a phased, iterative process for developing the Interim Approaches, the agencies will also consider public comments on the Interim Approaches in connection with the development of upcoming Registration Review decisions. The details of the joint Int erim Approaches are contained in the white paper “Interim Approaches for National

- Level Pesticide Endangered Species Act Assessments Based on the Recommendations of the National Academy of Sciences Apr il 2013 Report,” dated November 1, 2013.

Given that the agencies are continuing to develop and work toward implementation of the Interim Approaches to assess the potential risks of pesticides to listed species and their designated critical habitat, thi s preliminary risk assessment for ethoprop does not contain a complete ESA analysis that includes effects determinations for specific listed species or designated critical habitat. Although EPA has not yet completed effects determinations for specific species or habitats, for this preliminary asse ssment EPA conducted a screening

- level

assessment for all taxa of non

- target wildlife and plants that assumes for the sake of the assessment that listed species and designated critical habitats may be present in the vicinity of the application of ethoprop

. This screening level assessment will allow EPA to focus its future evaluations on the types of species where the potential for effects exists once the scientific methods being developed by the agencies have been fully vetted. This screening

- level risk

as sessment for ethoprop indicates potential risks of direct effects to listed mammals, birds, terrestrial invertebrates, fish, and aquatic invertebrates on all of its registered use sites. Listed species of aquatic and terrestrial plants may also be affecte d through indirect effects because of the potential for direct effects on listed and non

- listed species upon which such species may rely. Potential direct effects on listed mammals, birds, terrestrial invertebrates, fish, and aquatic

invertebrates from th e use of ethoprop may be associated with modification of Primary Constituent Elements (PCEs) of designated critical habitats, where such designations have been made. Once the agencies have fully developed and implemented the scientific methods

necessary t o complete risk assessments for endangered and threatened (listed) species and their

### 67 designated critical habitats, these methods will be applied to subsequent analyses for ethoprop as part of completing this registration review.



## Conclusions

After revie wing the most recent environmental fate and effects data for ethoprop , the screening

level assessment concludes that registered uses of the pesticide may result in risk to both listed

and non

- listed species of aquatic and terrestrial animals and wildlife o ver a wide range of uses and through multiple exposure pathways

.

Acute and chronic risk to freshwater fish, estuarine/marine fish, freshwater invertebrates, and

estuarine/marine invertebrates , and both freshwater and estuarine sediment invertebrates was identified

. Risk was not identified for aquatic plants based on one available diatom study and is consistent with the insecticidal mode of action of ethoprop. Some uncertainty exists in the impacts on aquatic plants

, however

, due to lack of a complete da ta set

. LD 50 

### analysis indicated

that there is a cute risk to both birds and mammals from granular formulations. Additional information from the registrants on mass of a.i. per granule and weight of one granule would help in defining how many granules woul d have to be consumed to be of concern for both birds

and mammals. There was also acute dose based and acute dietary based risk as well as chronic dietary risk to birds associated with EC applications. Similarly , there was acute and chronic dose

based risk as well as chronic dietary based risk to mammals from EC applications

. I ndirect routes of exposure may include consumption of contaminated earthworms in treated fields. Modeling

indicated that there may be potential for acute avian risk from both dos e

- based and dietary exposure as well as chronic risk from dietary exposure through the consumption of earthworms

. There was low potential for r isk for mammals consuming contaminated earthworms

. Ethoprop is slightly to moderately volatile but modeling sugg ests that inhalation is not a risk to either birds or mammals. While ethoprop is applied by boom sprayer

, the coarse droplet size specified on

current labels reduces risk to terrestrial and aquatic taxa through spray drift.

As a pesticide

, risk to terr estrial invertebrates is predicted. Bee

- REX modeling confirmed if

exposure occurs
, pollinators foraging on fields during the time of application would also be at

risk. Results of past assessments and current application practices are designed to limit exp osure but exposure from residues on residual flowering plants or from spray drift is possible and would present a risk to pollinators and other beneficial insects. The overall risk conclusions for aquatic

and terrestrial taxa broken down b y each registere d use of ethoprop are presented below in T able

2 7 and Table 28 respectively.

Collectively

, for all registered uses of ethoprop , no risks to listed terrestrial plant species are anticipated but uncertainty exists due to lack of submitted data and the existence of two incidents in the EIIS database involving mortality to potato crops since the time of the last assessment.

The conclusions of this assessment remain largely uncha nged from previous assessments.

A dditional discussion of the risk is also present ed in the 1998 assessment.

### 68 Table 2 7

. Summary of adverse impacts for aquatic organisms expected from the registered uses of ethoprop.

Use (Application

rate lbs a.i./A Adverse Impacts Expected for Aquatic Organisms? (No/Yes: A = Acute, C=Chronic)

Freshwater

Fish Estuarine/Marine

Fish Freshwater

Invertebrates (Water Column) Estuarine/

Marine

Invertebrates (Water Column) Freshwater and

Saltwater

Benthic

Invertebrates

(Sediment) Freshwater

Benthic

Invertebrates (Pore water) Saltwater

Benthic

Invertebrates (Pore water) Aquatic

Plants

Cucurbits (1.95) Yes A,C Yes A,C Yes A,C Yes A,C No Data Yes A,C Yes A,C No

Hops, Nursery Stock, Sugar Beets (3) Yes A,C Yes A,C Yes A,C Yes A,C No Data Yes A,C Yes A,C No

Sweet Potato (3.9) Yes A,C Yes A,C Yes A,C Yes A,C No Data Yes A,C Yes A,C No

Sugarcane (4) Yes A,C Yes A,C Yes A,C Yes A,C No Data Yes A,C Yes A,C No

Cabbage (5.1) Yes A,C Yes A,C Yes A,C Yes A,C No Data Yes A,C Yes A,C No

Corn, Mint, Tobacco (6) Yes A,C Yes A,C Yes A,C Yes A,C No Data Yes A,C Yes A,C No

Succulent (lima) beans Yes A,C Yes A,C Yes A,C Yes A,C No Data Yes A,C Yes A,C No

Potatoes (East

of the Mississippi (9) Yes A,C Yes A,C Yes A,C Yes A,C No Data Yes A,C Yes A,C No

### 69 Potatoes (West

of the Mississippi (12) Yes A,C Yes A,C Yes A,C Yes A,C No Data Yes A,C Yes A,C No

### 70 Table 28

. Summary of adverse impacts for terrestrial organisms expected from the registered uses of ethoprop.

Use (Application

rate lbs

a.i./A Adverse Impacts Expected for Terrestrial Organisms? (No/Yes: A = Acute, C=Chronic)

Birds Mammals Birds consuming

earthworms Mammals consuming

earthworms Terrestrial Plants Terrestrial

Invertebrates 1 Birds and

mammals through

inhalation

Cucurbits (1.95) Yes A,C Yes A,C Yes A No No data Yes A,C No

Hops, Nursery Stock, Sugar Beets (3) Yes A,C Yes A,C Yes A No No data Yes A,C No

Sweet Potato (3.9) Yes A,C Yes A,C Yes A No No data Yes A,C No

Sugarcane (4) Yes A,C Yes A,C Yes A No No data Yes A,C No

Cabbage (5.1) Yes A,C Yes A,C Yes A, No No data Yes A,C No

Corn, Mint, Tobacco (6) Yes A,C Yes A,C Yes A No No data Yes A,C No

Succulent (lima) beans Yes A,C Yes A,C Yes A No No data Yes A,C No

### 71 Use (Application

rate lbs

a.i./A Adverse Impacts Expected for Terrestrial Organisms? (No/Yes: A = Acute, C=Chronic)

Birds Mammals Birds consuming

earthworms Mammals consuming

earthworms Terrestrial Plants Terrestrial

Invertebrates 1 Birds and

mammals through

inhalation

Potatoes (East of the Mississippi (9) Yes A,C Yes A,C Yes A No No data Yes A,C No

Potatoes (West of the Mississippi (12) Yes A,C Yes A,C Yes A No No data Yes A,C No

### 72 

## Uncertainties, Limitations , and Identification of Data Gaps

Data Gaps and Uncertainties



## Environmental Fate

The environmental fate database for ethoprop is complete enough to conduct a risk assessment but there are limitations in the database such that additional data might reduce uncertainties. Although a valid aerobic soil metabolism study (OCSPP Guideline no. 835.4100) has been submitted and previously ac cepted to fulfill data requirements

, EFED current ly requires four such studies for pesticides with significant outdoor uses and believes that submission of

additional studies would reduc e the uncertainty regarding the persistence of ethoprop in aerobic

soi l. For other environmental fate guideline studies additional data, while not required at this time, could reduce uncertainties in the risk assessment: (1.) An extended hydrolysis study (EFED

has relied on an early study at elevated temperatures to extrapol ate a value for modeling input since the study accepted under Guideline no. 835.2120 did show enough hydrolysis to calculate a

rate in the standard 30

- day study). Results of the hydrolysis studies are significant for aquatic exposure modeling, especially for groundwater that could impact surface waters during interflow periods or affect terrestrial organisms when used for irrigation. (2.) An anaerobic aquatic study (Guideline no. 835.4400) has been waived, but submission of such a study could potentially

r educe uncertainty in aquatic exposure assessments.



## Ecological Effects

There are a number of areas of uncertainty in the aquatic and terrestrial risk assessments. The toxicity assessment for terrestrial and aquatic plants and animals is limited by the n umber of species tested in the available toxicity studies. Use of toxicity data on representative species does not provide information on the potential variability in susceptibility to acute and chronic

exposures.

For each registered use, the risk asses sment is based on the maximum application rate on the registered label. The frequency at which actual uses approach these maximum scenarios is dependent on the resistance to the pesticide, the timing of applications, and market forces. Exposure and risks c ould be overestimated if the actual application rates, frequency of application, or number of applications are lower than the input parameters used for the conservative exposure scenario that was modeled. However, if there are conditions under which

there is more than one growing season for a crop within a single year, exposure estimates and risk to aquatic and terrestrial organisms could be significantly underestimated.

Terrestrial Exposure Assessment

The exposure assessment for terrestrial organisms in this risk assessment relies on the best available estimates of environmental fate and physicochemical properties, maximum application

### 73 rate of ethoprop , maximum number of applications, and the shortest in terval between applications. However, several uncertainties and model limitations are noted and should be considered in interpreting the results of this terrestrial risk assessment

.

When effects data are available, dose

- based and dietary

- based acute RQs should be provided to risk managers. The dose

- based approach assumes that the uptake and absorption kinetics of a gavage toxicity study approximate the absorption associated with uptake from a dietary matrix. Toxic response is a function of duration and intensity of exposure. Absorption kinetics across the gut and enzymatic activation/deactivation of a toxicant may be important and are likely variable across chemicals and species. For many compounds, a gavage dose represents a very short

- term, high int ensity exposure, whereas dietary exposure may involve a more prolonged exposure period

. The dietary

- based approach assumes that animals in the field are consuming food at a rate similar to that of confined laboratory animals. Energy content in food items differs between the field and the laboratory as do the energy requirements of wild and captive animals. The Wildlife Exposure Factors Handbook can provide insights into energy requirements of animals in the wild as well as energy content of their diets ( USEPA, 1993).

The typical 21

- week avian reproduction study does not define the true exposure duration needed to elicit the observed responses. The study protocol was designed to establish a steady

- state tissue concentration for bioaccumulative compounds. For other pesticides, it is entirely possible that steady

- state tissue concentrations are achieved earlier than the 21

- week exposure period. Moreover, pesticides may exert effects at critical periods of the reproduction cycle; therefore, long

term exposu re may not be necessary to elicit the effect observed in the 21

- week protocol. The EFED screening

- level risk assessment uses the single

- day maximum estimated EEC as a conservative approach. The degree to which this exposure is conservative cannot be dete rmined by the existing reproduction study.

In the risk assessment, RQs were only calculated for the most sensitive dietary class relevant to the organisms assessed. For most organisms, not enough data is available to conclude that birds or mammals may no t exclusively feed on a dietary class for at least some time period. However, most birds and mammals consume a variety of dietary items and thus the RQ will overestimate risk to those organisms. Additionally, some organisms will not feed on all of the di etary classes. For example, many amphibians would only consume insects and not any plant material.

• Other General Uncertainties for Screening Risk Assessments

Routes of Exposure

The screening assessment does not consider ethoprop dermal exposure to terrestrial organisms. The Agency is actively pursuing modeling techniques to account for dermal exposure via direct application of spray and by incidental contact with contaminated vegetation, soil and water.

Age Class and Sensitivity of Effects Thresholds

### 74 It is generally recognized that test organism age may have a significant impact on the observed sensitivity to a toxicant. The screening risk assessment acute toxicity data for fish are collected on juvenile fish and aquatic invertebrate acute testing is performed on recommended immature age classes. Similarly, acute dietary testing with birds is also performed on juveniles, with mallard being 5

- 10 days old and quail at 10

- 14 days of age.

Testing of juveniles may overestimate the toxicity of direct acti ng pesticides in adults. As juvenile organisms do not have fully developed metabolic systems, they may not possess the ability to transform and detoxify xenobiotics equivalent to the older/adult organism. The screening risk assessment has no current provis ions for a generally applied method that accounts for this uncertainty. In so far as the available toxicity data may provide ranges of sensitivity information with respect to age class, the risk assessment uses the most sensitive life

- stage
information as the conservative screening endpoint.

Lack of Effects Data for Amphibians and Reptiles

Currently, toxicity studies on amphibians and reptiles are not required for pesticide registration. Since these data are lacking, the Agency uses fish as surrogates for aquatic phase amphibians and birds as surrogates for terrestrial phase amphibians and reptiles. If other species are more or less

sensitive to ethoprop than the surrogates, risks may be under

- or overestimated, respectively. The Agency is not limited t o a base set of surrogate toxicity information in establishing risk assessment conclusions. The Agency also considers toxicity data on non

- standard test species when available. Further research is needed to determine whether, in general, reptiles and

terr estrial

- phase amphibians are suitably represented by bird species in assessing risks for ethoprop and fish are an appropriate surrogate for aquatic

- phase amphibians.

Use of the Most Sensitive Species Tested

Although the screening risk assessment re lies on a selected toxicity endpoint from the most sensitive species tested, it does not necessarily mean that the selected toxicity endpoints reflect sensitivity of the most sensitive species existing in a given environment. The relative position of

the most sensitive species tested in the distribution of all possible species is a function of the overall variability among species to a particular chemical. The relationship between the sensitivity of the most sensitive tested species versus wild species (i ncluding listed species) is unknown and a source of significant uncertainty. In addition, in the case of listed species, there is uncertainty regarding the relationship of the listed species' sensitivity and the most sensitive species tested.

Sublethal Effects

When assessing acute risk, the screening risk assessment relies on the acute mortality endpoint as well as a suite of sublethal responses to the pesticide, as determined by the testing of species response to chronic exposure conditions and subsequ ent chronic risk assessment. Consideration

of additional sublethal data in the effects determination is exercised on a case

- by

- case basis and only after careful consideration of the nature of the sublethal effect measured and the extent and

### 75 quality of avai lable data to support establishing a plausible relationship between the measure of effect (sublethal endpoint) and the assessment endpoints. However, the full suite of sublethal effects from valid open literature studies is considered for the characteriza tion purposes.

To the extent to which sublethal effects are not considered in this assessment, the potential direct

and indirect effects of ethoprop on listed species may be underestimated.

Ecological Effects Data Gaps

The ecological effects data profile for ethoprop is essentially complete as indicated by the problem formulation and the last assessment. For this assessment, an avian reproduction study was received and incorporated into the assessment. There is not any terrestrial plant data for ethoprop. Other assessments with organophosphates have required aquatic and terrestrial plant studies (e.g. chlorethoxyfos) but the mode of action of organophosphates is not anticipated to impact plants. H owever
, t wo adverse i ncidents to plants have been reported for ethoprop

, so plant data on vegetative vigor and seedling emergence would be informative to examine if future incidents would be anticipated. There are also not any sediment invertebrate toxicity tests.

Given the mode of action of ethoprop and its very high toxicity to other aquatic taxa, both fish and invertebrates, risk to sediment fauna is presumed. Additional data on sediment invertebrates would likely not change any risk conclusions or provide any additional insights as to the risk posed to aquatic ecosystems. Similarly there are also not any larval honey bee or chronic adult honey bee toxicity tests. As an insecti ci de, risk to insects is presumed from use of ethoprop and risk can only be minimized by elimin ating exposure to the insecti ci de (e.g. current ground incorporation requirements.)

### 76 

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Hoerger, F., and E.E. Kenaga. 1972. Pesticide residues on plants: Correlation of representative data as a basis for estimation of their magnitude in the environment. In F. Coulston and F. Korte, eds., Environmental Quality and Safety: Chemistry, Toxicology, and Technology, Georg Thie me Publ, Stuttgart, West Germany, pp. 9

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McCall, P. J., Swann, R. L., Laskowski, D. A., Unger, S. M., Vrona, S. A. and Dishburger, H. J. 1980. Estimation of chemical mobility in soil from liquid chromatographic retention times, Bull. Environ. Contam. T oxicol., 24, 190

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Smelt, J.H., Van de Peppel

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### 77 Soil Biol. Biochem. 28: 1757

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USEPA. 2002. Technical Basis for the derivation of Equilibrium Partitioning S ediment Guidelines (ESGs) for the Protection of Benthic Organisms: Nonionic Organics [Draft].

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### 78 Substances, Office of Pesticide Programs, Environmental Fate and Effects Division, October 22, 2009 and issued November 10, 2009. Available online at : http://www.epa.gov/oppefed1/models/water/input_parameter_guidance.htm (accessed 03/27/2013).

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### 79 

## Bibliography of Ecological Effect and Environmental Fate Guideline Studies

MRID/Accession Studies for Ecological Data:

00022923 Hill, E.F.; Heath, R.G.; Spann, J.W.; et al. (1975) Lethal Dietary Toxicities of Environmental Pollutants to Birds: Special Scientific Report: Wildlife No. 191. (U.S. Dept. of the Interior, Fish and Wildlife Service, Patuxent Wildlife Research Cen ter; unpublished report)

00048779 Vilkas, A.G. (1977) Acute Toxicity of Mocap to the Grass Shrimp, Palaemonetes pugio , and Fiddler Crab, Uca pugilator : UCES Project # 11506

- 05

- 04. (Unpublished study received Jul 15, 1977 under 2224

- 43; prepared by Union Carbide Corp., submitted by Mobil Chemical Co., Industrial Chemicals Div., Richmond, Va.;

CDL:230885

- H)

00068325 Vilkas, A.G. (1977) Acute Toxicity of Ethoprop to the Water Flea, Daphnia magna Straus: UCES Proj. #1506

- 05

- 03. (Unpublished study received A ug 16, 1977 under 2224

- 44; prepared by Union Carbide Corp., submitted by Mobil Chemical Co., Industrial Chemicals Div., Richmond, Va.; CDL:231370

- B)

00066220 Atkins, E.; Anderson, L.; Kellum, D.; et al. (1977) Protecting Honey Bees from

Pesticides. Rivers ide, CA: Univ. of California. (Leaflet 2883; also In unpublished submission received Nov 2, 1983 under 239

- 2507; submitted by Chevron Chemical Co., Richmond, CA;

CDL:251760

- B) (Study is duplicate of MRID# 00132710)

00078038 Weir, R.J.; Clark, O. (1966) Ac ute Oral LD50

-- Hens: Project No. 230

- 108. (Unpublished study received Nov 25, 1968 under 9F0750; prepared by Hazleton Laboratories, Inc., submitted by Mobil Chemical Co., Macedon, N.Y.; CDL:091295

- F)

00078042 Weir, R.J. (1967) Final Report: Acute Aqueou s Exposure

-- Goldfish, Bluegill, and Rainbow Trout: Project No. 230

- 111. (Unpublished study received Nov 25, 1968 under 9F0750; prepared by Hazleton Laboratories, Inc., submitted by Mobil Chemical Co., Macedon,
N.Y.; CDL:091295

- J)

00092147 Fink, R.; Beaver s, J.B.; Brown, R. (1978) Final Report: Acute Oral LD50

- Mallard Duck: Ethoprop Technical: Project No. 155

- 104. (Unpublished study received Jan 4, 1979 under

2224

- 54; prepared by Wildlife International, Ltd., submitted by Mobil Chemical Co., Industrial

Che micals Div., Richmond, Va.; CDL:236710

- C)

00160000 Hudson, R.; Tucker, R.; Haegele, M. (1984) Handbook of toxicity of pesticides to wildlife: Second edition. US Fish and Wildlife Service: Resource Publication 153. 91 p.

### 80 60187 Swigert, J.; Bowman, J. (1986) Acute Toxicity of Ethoprop to Blue

- gill Sunfish (Lepomis macrochirus): Static Acute Toxicity Report #34319. Unpublished study prepared by Analytical Bio

- Chemistry Laboratories, Inc. 53p

00160188 Forbis, A.; Frazier, S.; Schoen, L. (1986) Acute Toxicity of Ethoprop Technical to Daphnia magna: Static Acute Toxicity Report #34320. Unpublished study prepared by Analytical Bio

- Chemistry Laboratories, Inc. 38 p.

05008363 Hudson, R.H.; Haegele, M.A.; Tucker, R.K. (1979) Acute oral and

percutaneous t oxicity of pesticides to mallards: correlations with mammalian toxicity data. Toxicology and Applied Pharmacology 47(3):451

- 460.

40228401 Mayer, F.; Ellersieck, M. (1986) Manual of Acute Toxicity: Interpretation and Data Base for 410 Chemicals and 66 Spe cies of Freshwater Animals. US Fish & Wildlife Service, Resource Publication 160. 579 p. (Study is duplicate of MRID# 40098001)

40378401 Schafer, E.W.; Brunton, R.B. 1979. Indicator bird species for toxicity determinations: Is the technique usable in tes t method development? Vertebrate Pest Control and Management Materials, ASTM STP 680, J.R. Beck, Ed., American Society for Testing and Materials, 1979, pp. 157

- 168. (cited in the EFED Environmental Risk Assessment as reference GS0106004)

40650101 Surpren ant, D. (1988) The Chronic Toxicity of Ethoprop Technical to Daphnia magna under Flow

- through Conditions: Report #87

- 10

- 2512: Study #10566

- 0986

- 6105

- 130. Unpublished study prepared by Springborn Life Sciences, Inc. 44 p.

40650102 Surprenant, D. (1987) Th e Toxicity of Ethoprop Technical to Fathead Minnow (Pimephales promelas) Embryos and Larvae: SLS Report #: BW

- 87

- 6

- 2408; SLS Study # 10566.0986.6105.120. Unpublished study prepared by Springborn Life Sciences, Inc. 41 p.

43686301 Machado, M. (1995) Ethop rop Technical

-- Acute Toxicity to Sheepshead Minnow (Cyprinodon variegatus) Under Flow

- Through Conditions: Final Report: Lab Project Number: 95

- 4

- 5811: 10566.1294.6348.505. Unpublished study prepared by Springborn Labs, Inc. 71 p.

### 81 43686302 Dionne, E. ( 1995) Ethoprop Technical

-- Acute Toxicity to Eastern Oyster (Crassostrea virginica) Under Flow

- Through Conditions: Final Report: Lab Project

Number: 95

- 5

- 5839: 10566.1294.6350.504. Unpublished study prepared by Springborn Labs, Inc. 71 p.

43686303 Machado , M. (1995) Ethoprop Technical

-- Acute Toxicity to Mysids (Mysidopsis bahia) Under Flow

- Through Conditions: Final Report: Lab Project

Number: 95

- 4

- 5802:10566.1294.6349.515. Unpublished study prepared by Springborn Labs, Inc. 71 p.

43877401 Putt, A. (1995) Ethoprop Technical

-- The Chronic Toxicity to Daphnia magna

Under Flow

- Through Conditions: Final Report: Lab Project Number: 95

- 5

- 5857: 10566.1294.6351.130. Unpublished study prepared by Springborn Labs, Inc. 115 p.

44114001 Klonne , D. (1996) Summary of Acute Toxicity and Cholinesterase

- Inhibiting Potential for Several Possible Ethoprop Plant Metabolites: 1) O

- Ethyl

- S

propylphosphorothioate ("M1" Metabolite), 2) Ethyl Phosphate, 3) O

- Ethyl

- O

- methyl

S

- propylphosphorothioate, 4) O

- Eth yl

- S

- methyl

- Spropylphosphorodithioate: Lab Project Number: ETP

- M1

- 96

- 002: 53

- 537: 90

- 85

- 11194. Unpublished study prepared by Rhone

- Poulenc Ag Co. 70 p.

4312701 Taliaferro, M.; Miller, V. (1997) Reproduction Study with Ethoprop in the Northern Bobwhite (C olinus virginianus): Lab Project Number: 029516: EBA

- 029516. Unpublished study prepared by EBA, Inc. 319 p.

44312702 Taliaferro, M.; Miller, V. (1997) Reproduction Study with Ethoprop in the Mallard Duck (Anas platyrhynchos): Lab Project Number: 029515: EBA

- 029515. Unpublished study prepared by EBA, Inc. 313 p.

44457501 Sousa, J. (1997) Ethoprop Technical: Chronic Toxicity to Mysids (Mysidopsis bahia) under Flow

- Through Conditions: Lab Project Number: 97

- 10

- 7128: 10566.0497.6418.530. Unpublished study p repared by Springborn Laboratories, Inc. 98

p.

44472101 Sousa, J. (1997) Ethoprop Technical

-- Early Life

- Stage Toxicity Test with Sheepshead Minnow (Cyprinodon variegatus): Final Report: Lab Project Number: 97

- 10

- 7127: 10566.0497.6419.520: 021797/FIFRA/52 0. Unpublished study prepared by Springborn Labs., Inc. 91 p.

### 82 

## MRID/Accession Studies for Environmental Fate Data:

161

- 1 Hydrolysis

MRID Citation Reference

67321 Boyd, G.R.; Gaskill, D.R. (1971) Hydrolysis of Prophos in Aqueous Solutions: Report No. A

- 61587

- C. (Unpublished study received Aug 16, 1977 under

2224

- 44; submitted by Mobil Chemical Co., In

- dustrial Chemicals Div., Richmond, Va.; CDL:231371

- D)

160165 N orris, F.; Guyton, C. (1986) Executive Summaries: Ethoprop. Un

- published summaries prepared by Rhone

- Poulenc Inc. 19 p.

160166 Norris, F. (1983) The Hydrolysis of Ethoprop in Aqueous Solution at Environmental pH's and Temperatures: ASD No. 83/059. Unpub lished study prepared by Rhone

- Poulenc Inc. 57 p.

41270703 Das, Y. (1989) Hydrolysis of ?1

- Ethyl

- ?carbon 14||Ethoprop in Aqueous Solutions Buffered at pH 5, 7, and 9: Project No. ISSI No. 89140. Unpublished study prepared by Innovative Scientific Service s, Inc., (ISSI). 76 p.

161

- 2 Photodegradation

- water

MRID Citation Reference

160167 Norris, K. (1985) Ethoprop (...) Absorption Characteristics in the Ultraviolet Region: ASD No. 85/122. Unpublished study prepared by Rhone

- Poulenc Inc. 9 p.

160168 Norris, F. (1983) The Photodegradation of Ethoprop in Aqueous Solution Using Simulated Sunlight: ASD No. 83/064. Unpublished study prepared by

Rhone

- Poulenc Inc. 33 p.

160169 Cresswell, D.; Hopkins, R. (1986) ([Carbon 14])

- Ethoprop: Photodegradati on Studies in in [sic] Water: Rept. No. 4728

- 68/36. Un

- published study prepared by Hazleton Laboratories Europe Ltd. 108 p.

41270702 Carpenter, M. (1989) "Photodegradation of ?Carbon 14|

- Ethoprop in pH 7 Buffered Solution": Project ID: ABC Final Report No. 38139. Unpublished study prepared by Analytical Bio

- Chemistry Laboratories, Inc. 45 p.

41568101 Carpenter, M. (1989) Photodegradation of ?carbon 14|

- Ethoprop in pH 7 Buffered Solution: Lab Project Number: 38139. Unpublished study prepared by Analytical Bio

- chemistry Laboratories, Inc. 745 p.

43833502 Gorman, M. (1995) Photodegradation of (carbon 14 )

- Ethoprop in pH 7

Buffered Solution

-- Supplemental Study: Final Report: Lab Project Number:

38139

- 1: EC

- 95

- 316: 38139. Unpublished study prepared by ABC Labs, Inc. 137 p.

### 83 161

- 3 Photodegradation

- soil

MRID Citation Reference

160170 Cresswell, D.; Hopkins, R. (1986) ([Carbon 14])

- Ethoprop: Photodegradation Studies in Soil: Rept. No. 3845

- 68/36. Unpublished study prepared by Hazleton Laboratories Europe Ltd. 111 p.

41270704 Carpenter, M. (1989) "Determination of the Photolysis Rate o f ?carbon 14|

- Ethoprop on the Surface of Soil": ABC Final Report No. 38140. Unpublished study prepared by Analytical Bio

- Chemistry Laboratories, Inc. 47 p.

41568102 Carpenter, M. (1989) Determination of the Photolysis Rate of ?carbon 14|

- Ethoprop on the Surface of Soil: Lab Project Number: 38140. Unpublished study prepared by Analytical Bio

- chemistry Laboratories, Inc. 747 p.

43833501 Gorman, M. (1995) Determination of the Photolysis Rate of (carbon 14)

- Ethoprop on the Surface of Soil

-- Supplemental Stud y: Amended Final Report: Lab Project Number: 38140

- 1: EC

- 95

- 316: 38140. Unpublished study prepared by ABC Labs, Inc. 117 p.

161

- 4 Photodegradation

- air

MRID Citation Reference

41388701 Carpenter, M.; Gorman, M. (1990) Photodegradation Study of Ethoprop in Air: Lab Project Number: 38216. Unpublished study prepared by Analytical Bio

Chemistry Laboratories. 37 p.

41596401 Carpenter, M.; Gorman, M. (1990) Photodegradation Study of Ethoprop in Air: Lab Project Number: 38216. Unpublished study prepared by Analytical Bio

Chemistry Laboratories. 483 p.

162

- 1 Aerobic soil metabolism

MRID Citation Reference

160171 Jordan , E. (1986) Metabolism of Ethoprop (...) in Soil under Aerobic and Anaerobic Conditions: ASD No. 86/199. Unpublished study prepared by

Rhone

- Poulenc Inc. in cooperation with Mobil Environmental and Science Lab. 147 p.

162

- 2 Anaerobic soil metabolis m

MRID Citation Reference

160171 Jordan , E. (1986) Metabolism of Ethoprop (...) in Soil under Aerobic and Anaerobic Conditions: ASD No. 86/199. Unpublished study prepared by

Rhone

- Poulenc Inc. in cooperation with Mobil Environmental and Science Lab. 147 p.

### 84 163

- 1 Leaching /adsorption /de sorption

MRID Citation Reference

40384 Huvar, A.J.; DuVal, A. (1970) Loss of Prophos from Dry and Wet 10% Mocap Granules: Project No. 253. (Unpublished study received Sep 2, 1971 under 2F1204; submitted by Mobil Chemical Co., Richmond, Va.; CDL:094057

- H)

57209 Boyd, G.R.; DuVal, A. (1966) The Disappearance of V

- C 9

- 104 from Treated Soil: Report No. RN 66

- 2. (Unpublished study received Feb 28, 1966 under unknown admin. no.; submitted by Mobil Chemical Co., Industrial Chemicals Div., Richmond, Va.; CDL:105954

- D)

76721 Norris, F.A. (1979) Letter sent to D.D. Phillips dated Jun 12, 1979: Soil dissipation studies, ethoprop alone and in combination with trifluralin: Project No. 15915. (Unpublished study received Mar 19, 1981 under 2224

- 44; submitted by Mobil Chemical Co., Industrial Chemicals Div., Richmond, Va.;

CDL:244801

- A)

92040 DuVal, A.F.; Boyd, G.R. (1966) The Disappearance of V

- C 9

- 104 from

Treated Soil: RN 66

- 2. (Unpublished study received Feb 28, 1966 under 2224

- 37; submitted by Mobil Chemical Co., Industr ial Chemicals Div., Richmond, Va.; CDL:006815

- G)

92103 Mobil Chemical Company (1968) The Fate of Mocap in Soil and Plants. (Unpublished study received on unknown date under 9F0750; CDL: 098645

- D)

160172 Jordan, E. (1985) Adsorption

- desorption of Ethopr op

- O

- ethyl

- 1

- [car

- bon 14] by Four Agricultural Soils: ASD No. 85/128. Unpublished study prepared by

Rhone

- Poulenc Inc. 53 p.

160173 Perrette, T. (1986) Mobility of O

- Ethyl

- S,S

- di

- n

- propyl Phosphoro

- dithioate (Ethoprop) in Four Soil Types: ASD No. 86/17 0. Un

- published revision of ASD No. 84/103, prepared by Rhone

- Poulenc Inc. 35 p.

41340501 Cameron, B.; Hall, B.; Jamieson, J. (1989) [Carbon 14]

- Ethoprop: Aged Soil Leaching: Lab Project Number: 140951 : 7045. Unpublished study prepared by

Inveresk Rese arch International. 77 p.

41547701 Cameron, B.; Hall, B.; Jamieson, J. (1989) ?Carbon 14|

- Ethoprop: Aged Soil Leaching: Addendum: Lab Project Number: 140951: 7045A. Unpublished study prepared by Inveresk Research International. 25 p.

43778601 Feung, C.; Stillwell, D. (1995) O

- Ethyl

- S

- Propyl Phosphorothioic Acid (Ethoprop Metabolite) Adsorption/Desorption Study: Lab Project Number: EC

94

- 291. Unpublished study prepared by Rhone

- Poulenc Ag Co. and A & L Great Lakes Lab., Inc. 126 p.

163

- 2 Volatility

- lab

MRID Citation Reference

### 85 41211201 Carpenter, M. (1989) Laboratory Volatility from Soil of Ethoprop: ABC Laboratory Project ID 38001. Unpublished study prepared by Analytical Bio

Chemistry Laboratories, Inc. 784 p.

164

- 1 Terrestrial field dissipation

MRID Citation Reference

40382 Huvar, A.J.; Bolinskey, B.; Boyd, G.R.; et al. (1969) Percolation of Prophos (Mocap) through the Soil: Project No. 253. (Unpublished study received Sep 2, 1971 under 2F1204; subm itted by Mobil Chemical Co., Richmond, Va.;

CDL:094057

- F)

57209 Boyd, G.R.; DuVal, A. (1966) The Disappearance of V

- C 9

- 104 from Treated Soil: Report No. RN 66

- 2. (Unpublished study received Feb 28, 1966 under unknown admin. no.; submitted by Mobil Chemi cal Co., Industrial Chemicals Div., Richmond, Va.; CDL:105954

- D)

75252 DuVal, A.F.; Boyd, G.R. (1967) The Persistence of Mocap in Treated Soil: RN

67

- 3. (Unpublished study received Nov 25, 1968 under 9F0750; submitted by Mobil Chemical Co., Industrial Chemicals Div., Richmond, Va.; CDL:091296

- Q)

92033 Duval, A.F.; Boyd, G.R . (1967) The Persistence of Mocap in Treated Soil: Project 532. (Unpublished study received Jan 26, 1967 under unknown admin. no.; submitted by Mobil Chemical Co., In

- dustrial Chemicals Div., Richmond, Va.; CDL:006786

- A)

92034 Wilson, J.H., Jr.; Downing , C.R. (1966) The Soil Persistence and Effect on Nematode Population of Mocap Soil Incorporation Treatments in the Field: Project 789. (Unpublished study received Jan 26, 1967 under unknown admin. no.; submitted by Mobil Chemical Co., Industrial Chemicals Div., Richmond, Va.; CDL: 006786

- B)

92040 DuVal, A.F.; Boyd, G.R. (1966) The Disappearance of V

- C 9

- 104 from

Treated Soil: RN 66

- 2. (Unpublished study received Feb 28, 1966 under 2224

- 37; submitted by Mobil Chemical Co., Industrial Chemicals Div., Richmo nd, Va.; CDL:006815

- G)

92082 Mobil Chemical Company (19??) ?Recovery of Mocap

- equivalents from Beans and Soil|. (Compilation; unpublished study received Aug 19, 1969 under 0F0872; CDL:093170

- C)

160174 Guyton, C. (1986) The Dissipation of Ethoprop in Soil under Field Conditions: 1984 Field Program F

- 21: ASD No. 86/195. Unpublished study prepared by

Rhone

- Poulenc Inc. and Morse Laboratories, Inc. 168 p.

40470601 Norris, F. (1987) Measurement of Ethoprop Movement and Degradation in Florida Soils. Unpublished study prepared by Rhone

- Poulenc Ag Co. 29 p.

### 86 40519901 Norris, F. (1987) Field Report: Field Dissipation and Groundwater Monitoring Study. Unpublished study prepared by Rhone

- Poulenc AG Company. 21 p.

41712401 Norris, F. (1990) A Terrestrial Field Soil Dissipation Study with Ethoprop in Washington and North Carolina: Final Report. Lab Project numbers 40641;

EC/P

- 89

- 0012: R109

- 082/087;R122

- 009/011: ML 89

- 0095

- RHP. Unpublished study prepared by Rhone

- Poulenc Ag Co. in coop with A & L Eastern Ag Labs, Inc. and Morse Labs, Inc. 164 p.

41767201 Norris, F. (1990) A Terrestrial Field Soil Dissipation Study with Ethoprop in a California Soil: Lab Project No: 40863: EC

- 89

- 082: R102

- 076. Unpublished study prepared by Rhone

- Poulenc Ag Co., in cooperation with A & L Eastern Agric., Labs., Inc. and others. 150 p.

44398 001 Norris, F. (1997) Ethoprop: Terrestrial Soil Dissipation after Application to Turf: Final Report: Lab Project Number: 96M08726: 45369: 10159. Unpublished study prepared by American Agricultural Services, Inc. 923 p.

45304901 Norris, F.; Noling, J.; J ones, R. et al. (1988) Measurement of Ethoprop Movement and Degradation in Florida Soils. Unpublished study prepared by

Rhone

- Poulenc Ag Company. 37 p.

162

- 4 Aerobic aquatic metabolism

MRID Citation Reference

44989502 Lewis, C. (1993) (14

- carbon)

- Ethoprophos: Degradation and Retention in Water/Sediment Systems: Final Report: Lab Project Number: 68/135

- 1015: P6875D. Unpublished study prepared by Hazleton UK. 172 p.

165

- 0 Accumulation Studies

-- General

MRID Citat ion Reference

66341 U.S. Environmental Protection Agency, Environmental Research Laboratory (1981) Acephate, Aldicarb, Carbophenothion, DEF, EPN, Ethoprop, Methyl Parathion, and Phorate: Their Acute and Chronic Toxicity, Bioconcentration Potential, and Persistence as Related to M arine Environments: EPA

- 600/4

- 81

- 023. (Unpublished study)



## 165

- 4 Bioaccumulation in fish

MRID Citation Reference

160176 McAllister, W.; Cohle, P.; Burnett, J.; et al. (1986) Bioconcentration and

### 87 Depuration of [Carbon 14]

- Ethoprop by Bluegill Sun

- fish (Lepomis macrochirus) under Flow

- through Conditions: Final Report: Report No. 33068. Unpublished study prepared by Analytical Bio

- Chemistry Laboratories, Inc. 46

p.

160177 Bunch, B. (1986) Metabolite Characterization of [Carbon 14]

- Ethoprop in Bluegill Sunfish (Lepomis macrochirus): ABC Final Rept. #33991. Unpublished study prepared by Analytical Bio

- Chemistry Laboratories. 45 p.

41425601 Burgess, D. (1990) Uptake, Depurat ion and Bioconcentration of ?Carbon 14|

- Ethoprop by Bluegill Sunfish (Lepomis macrochirus) Project Number: 38161. Unpublished study prepared by Analytical Bio

- Chemistry Laboratories, Inc. 41

p.

41425602 Heitkamp, J. (1990) Characterization of ?Carbon 14|

- Ethoprop Residues in Bluegill (Lepomis macrochirus) Water and Tissues: Lab Project Number: 38162. Unpublished study prepared by Analytical Bio

- Chemistry Laboratories, Inc. 61 p.

43038401 Heintzelman, R. (1993) Selected Raw Data Submission Pertaining to Uptake, Depuration and Bioconcentration of (carbon 14)

- Ethoprop by Bluegill Sunfish (Lepomis macrochirus): Lab Project Number: 38161. Unpublished study prepared by Analytical Bio

- Chemistry Labs., Inc. 136 p.

43038402 Heintzelman, R. (1993) Selected Raw D ata Submission Pertaining to Characterization of (carbon 14)

- Ethoprop Residues in Bluegill Sunfish (Lepomis macrochirus) Water and Tissues: Lab Project Number: 38162. Unpublished study prepared by Analytical Bio

- Chemistry Labs., Inc. 181 p.

166

- 3 G round water Large

- scale retrospective

MRID Citation Reference

45729701 Van Kretschmar, J.; Daussin, S. (2002) Surface Water Monitoring for Residues of Ethoprop in High

- Use Areas in the United States : Lab Project Number:

00M19458: 19458

- 01: 19458

- 02. Unpublished study prepared by Bayer CropScience, Stone Environmental, Inc. and Agvise Laboratories. 61 p.

46674601 Lee, Robert. (2005) A Retrospective Groundwater Monitoring Study for Ethoprophos and Metabolites in Five Regions of the USA. Bayer CropScience Study Number RAERX008. Unpublished study prepared by Bayer CropScience

and Stone Environmental, Inc. 338 p.

47417301 Jones. R.: Ramanaravanan, T.: Desmarteau, D. (2008) Response to EPA’s

Revised Et hoprophos Drinking water assessment. Bayer CropScience Project Number: G201876, 00M1945, M/240244/02/1. Unpublished study prepared by Bayer Cropscience. 13 p.

[No Guideline #] Surface water Large

- scale retrospective

### 88 46983601 Braun

, David C. and Robert J. Seymour . (2006) Surface Water Monitoring for Residues of Ethoprophos in High Use Areas in the United States, Amended Report. Bayer CropScience PSI Project No. RAERX004 , Study Number

00M19458

. Unpublished study prepared by Bayer CropScience

, Stone

Enviro nmental, Inc. , and Agvise Laboratories. 755 p.

47417301 Jones. R.: Ramanaravanan, T.: Desmarteau, D. (2008) Response to EPA’s Revised Ethoprophos Drinking water assessment. Bayer CropScience Project Number: G201876, 00M1945, M/240244/02/1. Unpublished stu dy prepared by Bayer Cropscience. 13 p.

### 89 

## APPENDICES

Appendix A: Chemical Structures of Ethoprop and Degradates

Residues of concern include: Ethoprop ( O

- ethyl

- S,S

- dipropyl phosphorodithioate ) 

### , ethoprop SME, and ethoprop OME.

Table 3

. Nomenclature of Ethoprop and its Metabolites of Concern.



### Structure

Molecular formula 

### [C 8 

### H 19 

### O 2 

### PS 2 

### ]

Molecular weight 242,33

Common name Ethoprop
Company experimental

name Ethoprop or ethoprophos

IUPAC and CAS name O

- ethyl

- S,S

- dipropyl phosphorodithioate

Chemical class Organophosphate
CAS registry number 13194

- 48

- 4

End

- use product (EP) 6 lb./gal EC (MOCAP ® 

### EC Nematicide

- Insecticide, EPA Reg. No. 264

- 458) 15% G (MOCAP ® 

### 15% Granular Nematicide

- Insecticide, EPA Reg. No.

264

- 457)

Structure



### Molecular formula C6H15O2PS2
Molecular weight 214.29

Chemical name O

- ethyl

- S

- methyl

- S

- propylphosphorodithioate

Structure

Molecular formula C 6 

### H 15 

### O 2 

### PS 2 

### Molecular weight 214.29 P O

O S C H 3

S
C H 3 C H 3



### C H 3 

### P O

O S C H 3



### S
C H 3

### 90 Table 3

. Nomenclature of Ethoprop and its Metabolites of Concern.



### Common name Ethoprop SME or Metabolite II or S

- methyl degradate

Chemical name O

- ethyl

- S

- methyl

- S

- propylphosphorodithioate

More Information: Degradate of concern for human health; may be toxic to non

- target animals but no significant environmental exposure expected

Structure

Molecular formula C 6 

### H 15 

### O 2 

### PS
Molecular weight 182.22

Common name Metabolite III (ethoprop O

- Me)

Chemical name O

- ethyl

- O

- methyl

- S

- propyl phosphorodithioate

Structure

Molecular formula 

### C 5 

### H 13 

### O 3 

### PS

Molecular weight 184.19

Common name Metabolite IV (M

- 1)

Chemical name O

- ethyl

- S

- propyl phosphorodithioate C H 3 P O

O S C H 3

O
C H 3



### C H 3 

### P O

O S C H 3



### O H

### 91 Figure 3 . Proposed pathway for ethoprop in soil (from registrant documents).

Figure taken from: R.L. Jones and F.A. Norris. 1998. Authors were involved in the generation of many of the environmental fate studies submitted to EPA to support the registration of ethoprop. Factors affecting degradation of aldicarb and ethoprop. Journal of Nematolo gy 30:45

- 55. Similar proposed pathways are provided in registrant submisssions such as MRID

00160171

.

### 92

### 93 

## Appendix B: Risk Quotients and Levels of Concern for Exposed Organisms

Agency Risk Quotient (RQ) Metrics and Levels of Concern (LOC) Per Risk Class.

Risk Class Risk Description RQ LOC

Aquatic Animals (fish and invertebrates)

Acute Potential for effects to non

- listed animals from acute

exposures Peak EEC/LC 50 1 0.5

Acute

Restricted Use Potential for effects to animals from acute exposures Risks may be mitigated through restricted use classification Peak EEC/LC 50 1 0.1

Acute Listed Species Listed species may be potentially affected by acute

exposures Peak EEC/LC 50 1 0.05

Chronic Potential for effects to non

- listed and listed animals from chronic exposures 60

- day EEC/NOAEC (fish) 1 21

- day EEC/NOAEC (invertebrates)

Aquatic Plants

Non

- Listed Potential for effects to non

- listed plants from exposures Peak EEC/LC 50 1 1

Listed Potential for effects to listed plants from exposures Peak EEC/NOAEC 1

Terrestrial Animals (mammals and birds) 2

Acute Potential for effects to non

- listed animals from acute

exposures EEC/LC 50 (Dietary) 0.5 EEC/LD 50 (Dose)

Acute

Restricted Use Potential for effects to animals from acute exposures Risks may be mitigated through restricted use classification EEC/LC 50 (Dietary) 0.2 EEC/LD 50 (Dose)

Acute Listed Species Listed species may be potentially affected by acute

exposures EEC/LC 50 (Dietary) 0.1 EEC/LD 50 (Dose)

Chronic Potential for effects to non

- listed and listed animals from chronic exposures EEC/NOAEC 1

Terrestrial and Semi

- Aquatic Plants

Non

- Listed Potential for effects to non

- target, non

- listed plants from

exposures EEC/ EC 25 1

Listed Plant Potential for effects to non

- target, listed plants from

exposures EEC/ NOAEC 1 EEC/ EC 05

1 LC 50 or EC 50

. 2 EEC based on upper bound Kenaga nomogram values for foliar exposure.



## Appendix C: Aquatic Exposure Modeling selected Input and Output

### 94 Surface Water Concentration Calculator (SWI) Representative Input and out Output Files

FL Sugarcane Scenario Input file

Input highlights: Application at Depth no drift, applications every two years, 300

- day

aerobic soil half

- life assumed.

Ethoprop TTR CAM4 wDrft4Rt

1

True
109,,,
0,,,
25,,,
0,,,
0,,,
0,,,
40,,,
150,,,
300,,,
25,
0,,,
242.3,,,
.000827,,,
843,,,
0,0,
0,0,
0,0,
0,0,
0,0,
0,0,

2

1

,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

,,,,

,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

,,,, 4.48,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

,,,,,,,, False

,,,,,,,,,,,,,,,,,,,,,,,, ,,,,,,,,,,,,,,,,,,,,,,

,,,, 3,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

,,,,, .99,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

,,,,,,, 0,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

,,,,, .99,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

,,,,,,, .00,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

,,,,,,, .99,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

,,,,,,, .0,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

,,,,,, 5,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

,,,,, - 1,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

,,,,

,,,,, False

,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

,,,,

FLsugarcaneSTD

C: \ Models \ Inputs \ Metfiles \ W12844.dvf

True,True,False,False,False
False,30

False

10000

12

4.2

4.8

1E

- 08

0.5

0.05

0.5

1.35

0.04

5

0.006

1.19

30

0.005

0.04

5

0.4

False
1.0,1.0

1

1

2

1

31

12
100,300

100

0.1

1

0.78

0

32.5

0

0.1

### 95 0.2

1

4

1

600

2
10,95,
1.45,1.75,
0.066,0.178,
0.036,0.078,
2.32,0.29,
100,19,

,,

,,

False

25
1,16,1,16,1,16,1,16,25,1,16,1,16,1,16,1,16,1,1
6,1,16,1,16,1,16,,,,,,,,,,,,,,,,,,,,,,,,,,,, 1,1,2,2,3,3,4,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11
,11,12,12,,,,,,,,,,,,,,,,,,,,,,,,,,,,
91,91,91,91,91,91,91,91,91,91,91,91,91,91,91,9
1,91,91,91,91,91,91,91,91,91,,,,,,,,,,,,,,,,,,

,,,,,,,,,, .194,.215,.240,.268,.300,.334,.358,.584,.638,.
673,.675,.666,.662,.650 ,.631,.636,.659,.680,.6
99,.717,.699,.669,.624,.551,.468,,,,,,,,,,,,,,

,,,,,,,,,,,,,, .014,.014,.014,.014,.014,.014,.014,.014,.014,.
014,.014,.014,.014,.014,.014,.014,.014,.014,.0
14,.014,.014,.014,.014,.014,.014,,,,,,,,,,,,,,

,,,,,,,,,,,,,, 2.0,1.55,0.266,

0.1 ,0,

False

,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

,,,,,,



### FL Sugarcane Scenario Output Summary

Estimated Environmental Concentrations for Ethoprop TTR are presented in Table 1 for the USEPA standard pond with the LAsugarcaneSTD field scenario. A graphical presentation of the year

- to

- year peaks is presented in Figure 1. These values were generated with the Surface Water Concentration Calculator (SWCC Version 1.106). Critical input values for the model are summarized in Tables 2 and 3.

This model estimates that about 1.5% of Ethoprop TTR applied to the field eventually reaches the water body. The main mechanism of transport from the field to the water body is by runoff (99.1% of the total transport) followed by erosi on (0.86%).

In the water body, pesticide dissipates with an effective water column half

- life of 125.1 days. (This value does not include dissipation by transport to the benthic region; it includes only processes that result in removal of pesticide from th e complete system.) The main source of dissipation in the water column is hydrolysis (effective average half

- life = 150 days) followed by volatilization (750.9 days).

In the benthic region, pesticide dissipation is negligible (1915.9 days). The main sourc e of dissipation in the benthic region is hydrolysis (effective average half

- life = 1915.9 days). The vast majority of the pesticide in the benthic region (92.17%) is sorbed to sediment rather than in the pore water.

Table 1. Estimated Environmental Concentrations (ppb) for Ethoprop TTR

.

Peak (1

- in

- 10 yr) 47.0

4

- day Avg (1

- in

- 10 yr) 46.2

21

- day Avg (1

- in

- 10 yr) 44.8

60

- day Avg (1

- in

- 10 yr) 40.8

365

- day Avg (1

- in

- 10 yr) 21.2

Entire Simulation Mean 7.87

### 96 Table 2. Summary of Model Inputs for Ethoprop

.

Scenario LAsugarcaneSTD

Cropped Area Fraction 1

Koc (ml/g) 109

Water Half

- Life (days) @ 25 °C 0

Benthic Half

- Life (days) @ 0 °C 0

Photolysis Half

- Life (days) @ 40 °Lat 0

Hydrolysis Half

- Life (days) 150

Soil Half

- Life (days) @ 25 °C 300

Foliar Half

- Life (days) 0

Molecular Wt 242.3

Vapor Pressure (torr) .000827

Solubility (mg/l) 843

Table 3. Application Schedule for Ethoprop TTR.

Date (Days Since Emergence) Type Amount (kg/ha) Eff. Drift

- 1 Incorporated to 5

cm 4.48 .99 .0

Figure 1. Yearly Peak Concentrations

### 97 Variable Volume Water Model, SWCC Compatible Version

*******************************************
Performed on: 9/16/2014 at 17:53

Peak 1

- in

- 10 = 58.1 ppb

Chronic 1

- in

- 10 = 27.2 ppb Simulation Avg = 8.87 ppb

4

- day avg 1

- in

- 10 = 57.2 ppb

21

- day avg 1

- in

- 10 = 53.7 ppb

60

- day avg 1

- in

- 10 = 49.6 ppb

90

- day avg 1

- in

- 10 = 47.6 ppb

Benthic Pore Water Peak 1

- in

- 10 = 36.7 ppb

Benthic Pore Water 21

- day avg 1

- in

- 10 = 36.6 ppb

Benthic Conversion Factor = 4.73

- Pore water (ug/L) to
(total mass, ug)/(dry sed mass,kg)

Benthic Mass Fraction in Pore Water = 0.783E

- 01

YEAR Peak 4

- day 21

- day 60

- day 90

- day Yearly Avg Benthic Pk Benthic 21

- day

1 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00

2 1.58E+01 1.56E+01 1.47E+01 1.31E+01 1.21E+01 7.82E+00 1.03E+01 1.03E+01

3 5.35E+01 1.38E+01 3. 74E+00 4.13E+00 4.47E+00 1.95E+00 4.77E+00 4.98E+00

4 5.79E+01 5.70E+01 5.37E+01 4.98E+01 4.79E+01 2.76E+01 3.71E+01 3.71E+01

5 9.80E+00 9.85E+00 1.03E+01 1.13E+01 1.23E+01 4.57E+00 1.32E+01 1.39E+01

6 3.86E+01 3.80E+01 3.69E+01 3.35E+01 3.08E+01 1.69E+01 2.29E+01 2.29E+01

7 5.95E+00 5.97E+00 6.22E+00 6.88E+00 7.45E+00 2.77E+00 7.99E+00 8.36E+00

8 1.29E+01 1.27E+01 1.19E+01 1.06E+01 9.75E+00 5.50E+00 7.60E+00 7.58E+00

9 2.43E+00 2.44E+00 2.55E+00 2.81E+00 3.04E+00 1.12E+00 3.25E+00 3.40E+00

10 4.11E+01 4.05E+01 3.84E+01 3.51E+01 3.24E+01 1.77E+01 2.39E+01 2.39E+01

11 6.70E+00 6.74E+00 7.01E+00 7.72E+00 8.34E+00 3.13E+00 8.96E+00 9.38E+00

12 1.88E+01 1.85E+01 1.79E+01 1.73E+01 1.65E+01 9.60E+00 1.28E+01 1.28E+01

13 3.46E+00 3.48E+00 3.63E+00 4.01E+00 4.33E+00 1.62E+00 4.65E+00 4.87E+00

14 7.42E+01 7.30E+01 6.97E+01 6.15E+01 5.63E+01 3.04E+01 4.10E+01 4.09E+01

15 1.11E+01 1.12E+01 1.17E+01 1.28E+01 1.39E+01 5.25E+00 1.50E+01 1.57E+01

16 1.79E+01 1.77E+01 1.71E+01 1.52E+0 1 1.40E+01 7.85E+00 1.09E+01 1.09E+01

17 3.51E+00 3.53E+00 3.68E+00 4.07E+00 4.41E+00 1.62E+00 4.72E+00 4.94E+00

18 3.99E+01 3.92E+01 3.67E+01 3.36E+01 3.10E+01 1.68E+01 2.27E+01 2.27E+01

19 6.40E+00 6.44E+ 00 6.74E+00 7.45E+00 8.08E+00 2.90E+00 8.66E+00 9.07E+00

20 5.82E+01 5.72E+01 5.34E+01 4.83E+01 4.44E+01 2.38E+01 3.26E+01 3.26E+01

21 9.47E+00 9.51E+00 9.92E+00 1.10E+01 1.19E+01 4.37E+00 1.27E+01 1.33E+01

22 1.77E+01 1.75E+01 1.68E+01 1.55E+01 1.51E+01 9.63E+00 1.28E+01 1.28E+01

23 2.01E+01 5.52E+00 3.98E+00 4.41E+00 4.78E+00 1.88E+00 5.12E+00 5.36E+00

24 2.36E+01 2.33E+01 2.20E+01 1.96E+01 1.90E+01 1.16E+01 1.55E+01 1.54E+01

25 4.30E+00 4.32E+00 4.52E+00 4.98E+00 5.39E+00 2.03E+00 5.80E+00 6.07E+00

26 7.24E+01 7.14E+01 6.70E+01 5.92E+01 5.44E+01 2.98E+01 3.97E+01 3.97E+01

27 1.07E+01 1.07E+01 1.12E+01 1.23E+01 1.34E+01 4.88E+00 1.44E+01 1.50E+01

28 1.37E+01 1.35E+01 1.28E+01 1.18E+01 1.10E+01 6.30E+00 8.75E+00 8.73E+00

29 2.23E+00 2.24E+00 2.34E+00 2.59E+00 2.81E+00 1.03E+00 3.02E+00 3.16E+00

30 1.18E+01 1.16E+0 1 1.11E+01 9.96E+00 9.27E+00 5.70E+00 7.56E+00 7.55E+00

*************************************************************************************************

***

Effective compartment halflives averaged over simulation duration:

zero washout 0

zero metabolic 0 hydrolysis halflife (days) = 150.040126616221 zero photolysis 0 volatile halflife (days) = 587.713320830168 total water col halflife (days) = 119.525813639529

### 98 zero burial 0

zero benthic metab 0 benthic hydrolysis halflife (days) = 1915.86477013956 total benthic halflife (days) = 1915.864 77013956

*********************************************************************** Fractional Contribution of Transport Processes to Waterbody & Total Mass
(kg):

Due to Runoff = 0.9987 11.45

Due to Erosion = 0.0013 0.1467E

- 01

Due to Drift = 0.0000 0.000

*********************************************************************** Flow in/out Characteristics of Waterbody: Average Daily Runoff Into Waterbody (m3/s) = 1.983254077242644E

- 003

Baseflow Into Waterbody (m3/s) = 0.000000000000000E+000 Average Daily Flow Out of Waterbody (m3/s) = 1.983254077242588E

- 003

***********************************************************************

Inputs: 109.0 = oc partitioning coefficien t
0.000 = water column half Life 25.00 = reference temp for water column degradation

0.000 = benthic Half Life 0.000 = Reference temp for benthic degradation
2.000 = Q ten value 0.000 = photolysis half life

40.0 0 = reference latitude for photolysis study 150.0 = hydrolysis half life

242.3 = molecular wt

0.8270E

- 03 = vapor pressure

843.0 = solubility

0.1000E+06 = field area
0.1000E+05 = water body area

2.000 = initial depth 2.000 = maximum depth 2 1=vvwm, 2=usepa pond, 3 = usepa reservoir, 4 = const vol no
flow, 5 = const vol w/flow

F T = burial, else no burial

0.1000E

- 07 = mass transfer coefficient

0.5000 = PRBEN

0.5000E

- 01 = benthic compartme nt depth 0.5000 = benthic porosity

1.350 = benthic bulk density

0.4000E

- 01 = OC frcation in benthic sediment

5.000 = DOC in benthic compartment

0.6000E

- 02 = benthic biomass

1.190 = DFAC

30.00 = SS

0.5000E

- 02 = chlor ophyll

0.4000E

- 01 = OC frcation in water column SS

5.000 = DOC in water column

0.4000 = biomass in water column

FRACTION AREA CROPPED = 1.00000000000000

### 99 Maine Potato Scenario SWCC Model input and Output Summary



# Summary of Water Mo deling of Ethoprop and the USEPA

Standard Pond

Estimated Environmental Concentrations for Ethoprop are presented in Table 1 for the USEPA standard pond with the MEpotatoSTD field scenario. A graphical presentation of the year

- to

- year peaks is presented in Figure 1. These values were generated with the Surface Water Concentration Calculator (SWCC Version 1.106). Critical input values for the model are summarized in Tables 2 and 3. This model estimates that about 0.4% of Ethoprop applied to the field eventual ly reaches the water body. The main mechanism of transport from the field to the water body is by runoff (65.5% of the total transport), followed by spray drift (24.9%) and erosion (9.61%). In the water body, pesticide dissipates with an effective water co lumn half

- life of 129.2 days. (This value does not include dissipation by transport to the benthic region; it includes only processes that result in removal of pesticide from the complete system.) The main source of dissipation in the water column is hydro lysis (effective average half

- life = 150 days) followed by volatilization (928.8 days). In the benthic region, pesticide dissipation is negligible (1915.9 days). The main source of dissipation in the benthic region is hydrolysis (effective average half

- lif e = 1915.9 days). The vast majority of the pesticide in the benthic region (92.17%) is sorbed to sediment rather than in the pore water.

Table 1. Estimated Environmental Concentrations (ppb) for Ethoprop.

Peak (1

- in

- 10 yr) 32.5

4

- day Avg (1

- in

- 10 yr) 32.1

21

- day Avg (1

- in

- 10 yr) 30.8

60

- day Avg (1

- in

- 10 yr) 28.4

365

- day Avg (1

- in

- 10 yr) 15.2

Entire Simulation Mean 9.82

Table 2. Summary of Model Inputs for Ethoprop t.

Scenario MEpotatoSTD

Cropped Area Fraction 1

Koc (ml/g) 109

Water Half

- Life (days) @ 25 °C 0

Benthic Half

- Life (days) @ 0 °C 0

Photolysis Half

- Life (days) @ 40 °Lat 0

Hydrolysis Half

- Life (days) 150

Soil Half

- Life (days) @ 25 °C 300

Foliar Half

- Life (days) 0

Molecular Wt 242.3

### 100 Vapor Pressure (torr) .000827

Solubility (mg/l) 843

Table 3. Application Schedule for Ethoprop TTR CAM4 wDrft9Rt.

Date (Days Since Emergence) Type Amount (kg/ha) Eff. Drift

- 1 Incorporated to 5

cm 10.1 .99 .01

Figure 1. Yearly Peak Concentrations



### Groundwater Modeling Example Input

– Output Summary

(Used for characterization of potential irrigation hazard)

Groundwater Analysis for Ethoprop and the FLORIDA

- Potato

- Met File (13889.Dvf)

Jacksonville Scenario

- Estimated groundwater concentrations and breakthrough times for Ethoprop are presented in Table 1 for the FLORIDA

- potato

- Met File (13889.dvf) Jacksonville groundwater scenario. A graphical presentation of the daily concentrations in the aquifer is presented in Figure 1. These values were generated with the PRZM

- GW (Version 1.07). Critical input values for the model are

summarized in Tables 2 and 3.

Table 1. Groundwater Results for Ethoprop and the FLORIDA

- potato

- Met File (13889.dvf)

Jacksonville Scenario.

### 101 Peak Concentration (ppb) 197

Post

- Breakthrough Mean Concentration (ppb) 91.5

Entire Simulation Mean Concentration (ppb) 76.8

Average Breakthrough Time (days) 2931.985

Throughputs 3.738082

Table 2. Chemical Properties for Groundwater Modeling of Ethoprop .

Koc (ml/g) 109

Surface Soil Half Life (days) 300

Hydrolysis Half Life (days) 150

Diffusion Coefficint Air (cm2/day) 4300

Henry's Constant 2E

- 6

Enthalpy (kcal/mol) 21.7

Table 3. Pesticide application scheme used for Ethoprop . This application scheme was applied every year of the simulation.

Application Days

Relative to Emergence Date (02/15) Application Method Application Rate

(kg/ha)

- 1 Ground application with mass uniformly distributed to 7 cm 13.5

Figure 1. Aquifer Breakthrough Curve for Ethoprop and the FLORIDA

- Potato

- Met File (13889.Dvf) Jacksonville Scenario

### 102

### 103 

## Appendix D. T

- REX Model Input and Output

Chemical Name: Ethoprop

Seed Treatment? (Check if yes) FALSE

Use: 118

Product name and form: MOCAP 15% Granular

% A.I. (leading zero must be entered for formulations <1% a.i.): 100.00%

Application Rate (lb ai/acre) 

### 12

Half

- life (days): 

### 35

Application Interval (days):

Number of Applications: 

### 1

Are you assessing applications with
variable rates or intervals? 

### no

Endpoint Toxicity value

LD50 (mg/kg

- bw) 

### 4.21

LC50 (mg/kg

- diet) 

### 33.00

NOAEL (mg/kg

- bw)

NOAEC (mg/kg

- diet) 

### 0.95

Endpoint Toxicity value

LD50 (mg/kg

- bw) 

### 32.80

LC50 (mg/kg

- diet) Reported Chronic Endpoint 

### 2.30

Is dietary concentration (mg/kg

- diet) reported from
the available chronic mammal study? (yes or no) 

### no

Enter dietary concentration (mg/kg

- diet)

### 104 Estimated Chronic Diet Concentration Equivalent to Reported Chronic Daily

Dose 

### 46



# Dietary

- based EECs
(ppm) Kenaga

Values

Short Grass 2880.00

Tall Grass 1320.00 Broadleaf plants 1620.00 Fruits/pods/seeds 180.00
Arthropods 1128.00

Avian Body Ingestion (Fdry) Ingestion (Fwet) % body wgt FI

Class Weight (g) (g bw/day) (g/day) consumed (kg

- diet/day)

Small 20 5 23 114 2.28E

- 02

Mid 100 13 65 65 6.49E

- 02
Large 1000 58 291 29 2.91E

- 01

20 5 5 25 5.06E

- 03

Granivores 100 13 14 14 1.44E

- 02

1000 58 65 6 6.46E

- 02

Avian Body Adjusted LD50

Weight (g) (mg/kg

- bw)

20 3.54

100 4.51

1000 6.36



# Dose

- based EECs

(mg/kg

- bw) Avian Classes and Body Weights (grams)

small mid large

20 100 1000

Short Grass 3280.03 1870.41 837.41

Tall Grass 1503.35 857.27 383.81 Broadleaf plants 1845.02 1052.11 471.04 Fruits/pods 205.00 116.90 52.34 Arthropods 1284.68 732.58 327.99

Seeds 45.56 25.98 11.63



# Dose

- based RQs

(Dose

- based EEC/adjusted LD50) Avian Acute RQs Size Class (grams)

20 100 1000

Short Grass 926.74 415.12 131.58

Tall Grass 424.76 190.26 60.31

### 105 Broadleaf plants 521.29 233.51 74.01 Fruits/pods 57.92 25.95 8.22 Arthropods 362.97 162.59 51.53

Seeds 12.87 5.77 1.83



# Dietary

- based RQs

(Dietary

- based EEC/LC50 or NOAEC) RQs

Acute Chronic

Short Grass 87.27 3025.21

Tall Grass 40.00 1386.55 Broadleaf plants 49.09 1701.68 Fruits/pods/seeds 5.45 189.08
Arthropods 34.18 1184.87

Mammalian Body Ingestion (Fdry) Ingestion (Fwet) % body wgt FI

Class Weight (g bwt/day) (g/day) consumed (kg

- diet/day)

15 3 14 95 1.43E

- 02

Herbivores/ 35 5 23 66 2.31E

- 02

insectivores 1000 31 153 15 1.53E

- 01

15 3 3 21 3.18E

- 03

Grainvores 35 5 5 15 5.13E

- 03

1000 31 34 3 3.40E

- 02

Mammalian Body Adjusted Adjusted

Class Weight LD50 NOAEL

15 72.09 5.06

Herbivores/ 35 58.33 4.09

insectivores 1000 25.23 1.77

15 72.09 5.06

Granivores 35 58.33 4.09

1000 25.23 1.77



# Dose

- Based EECs

(mg/kg

- bw) Mammalian Classes and Body weight

(grams)

15 35 1000

Short Grass 2745.86 1897.76 440.00

Tall Grass 1258.52 869.80 201.67 Broadleaf plants 1544.55 1067.49 247.50 Fruits/pods 171.62 118.61 27.50 Arthropods 1075.46 743.29 172.33

### 106 Seeds 38.14 26.36 6.11



# Dose

- based RQs

(Dose

- based EEC/LD50 or NOAEL) Small mammal Medium mammal

15 grams 35 grams

Acute Chronic Acute Chroni

Short Grass 38.09 543.20 32.54 463.99

Tall Grass 17.46 248.96 14.91 212.66 Broadleaf plants 21.43 305.55 18.30 261.00 Fruits/pods 2.38 33.95 2.03 29.00 Arthropods 14.92 212.75 12.74 181.73

Seeds 0.53 7.54 0.45 6.44



# Dietary

- based RQs

(Dietary

- based EEC/LC50 or NOAEC) Mammal RQs

Acute Chronic

Short Grass #DIV/0! 62.61

Tall Grass #DIV/0! 28.70 Broadleaf plants #DIV/0! 35.22 Fruits/pods/seeds #DIV/0! 3.91
Arthropods #DIV/0! 24.52



### LD50 ft

- 2

INPUTS Do not overwrite these

numbers.

Application Rate: 12 lbs / acre

% A.I.: 100.00% Avian LD50 (20g): 3.54 mg/kg bw (100g) 4.51 (1000g) 6.36 Mammalian LD50 (15g): 72.09 mg/kg bw (35g) 58.33 (1000g) 25.23 Row Spacing: 0 inches

Bandwidth: 0 inches
Unincorporation: 15%



### Broadcast applications

Granular

### 107 Intermediate Calculations

mg ai/ft2: 18.74



### LD50 ft

2
wgt class (grams)

Avian 20 264.79

100 41.60

1000 2.94

Mammal 15 17.33

35 9.18

1000 0.74

### 108 

## Appendix E . STIR Model Example



# Output

Results Avian (0.020 kg )
Maximum Vapor Concentration in Air at Saturation (mg/m 3 ) #VALUE!

Maximum 1

- hour Vapor Inhalation Dose (mg/kg) #VALUE!

Adjusted Inhalation LD 50 3.33E+01

Ratio of Vapor Dose to Adjusted Inhalation LD 50 #VALUE!

Maximum Post

- treatment Spray Inhalation Dose (mg/kg) 1.27E+00 Ratio of Droplet Inhalation Dose to Adjusted Inhalation

LD 50 3.81E

- 02



### Results Mammalian (0.015 kg )
Maximum Vapor Concentration in Air at Saturation (mg/m 3 ) #VALUE!

Maximum 1

- hour Vapor Inhalation Dose (mg/kg) #VALUE!

Adjusted Inhalation LD 50 2.37E+03

Ratio of Vapor Dose to Adjusted Inhalation LD 50 #VALUE!

Maximum Post

- treatment Spray Inhalation Dose (mg/kg) 1.59E+00 Ratio of Droplet Inhalation Dose to Adjusted Inhalation

LD 50 6.72E

- 04



## Appendix F. Earthworm Fugacity Model

Table 2. Characteristics of Ethoprop.

Parameter (symbol) Value Units

Pesticide Name Ethoprop none Molecular weight (MW) 164.38 g/mol

Octanol

- water Partition Coefficient (Kow) 38905 none
Soil partition coefficient (Kd) 0.3 cm 3 /g

Table 3. Soil parameters. Parameter (symbol) Value Units

Bulk density of soil (ρs)* 2.45 g/cm 3
Concentration of pesticide in soil (estimated using PRZM) do not enter value for this cell calculated automatically 0.009078839 g/m 3

Concentration of Ethoprop in soil (Cs) 5.52E

- 05 mol/m 3

Table 4. Earthworm parameters. Parameter (symbol) Value Units Lipid fraction of earthworm (L) 0.01 none Water fraction of earthworm (W) 0.84 none
Density of earthworm (ρE) 1000 kg/m 3

### 109 Concentration of Ethoprop in earthworm (CE) 2.92E

- 02 mol/m 3
Concentration of Ethoprop in earthworm (CE') 0.004806 g/kg*
*equivalent to mg/g

Table 5. Mammalian toxicity data for Ethoprop. Endpoint/Parameter (symbol) Value Units

Acute oral LD 50 32.8 mg/kg

- bw
Body weight of acute test animal* (TW) 350 g

Chronic NOAEL 2.3 mg/kg

- bw

Chronic NOAEC 46 mg/kg

- diet
Body weight of chronic test animal* (TW) 350 g Body weight of assessed animal (AW) 350 g Food intake of assessed animal (F) 14.0 g/day
Body weight normalized food intake of assessed animal (F N ) 40 g/kg

- bw

- day

*For rats, the default body weight is 350 g, if no other data are available.

Table 6. Avian toxicity data for Ethoprop. Endpoint/Parameter (symbol) Value Units

Acute oral LD 50 4.21 mg/kg

- bw

Body weight of test animal for LD 50 * (TW) 63.6 g
Subacute dietary LC 50 33 mg/kg

- diet

Chronic NOAEC 0.95 mg/kg

- diet
Mineau Scaling Factor** 1.15 none Body weight of assessed animal (AW) 63.6 g Food intake of assessed animal (F) 23.00 g/day
Body weight normalized food intake of assessed animal (F N ) 362 g/kg

- bw

- day
*Unless study specific data are available: For bobwhite quail, assume 178 g. For mallard duck, assume 1580 g. **Default value is 1.15. Consult Mineau et al. (1996) to obtain pesticide specific values.

Table 7. Mammalian and avian risk quotients for Ethoprop. Endpoint EEC Toxicity Value RQ

Mammalian, acute dose

- based 0.19 32.8 0.01

Mammalian, chronic dose

- based 0.19 2.3 0.08
Mammalian, chronic dietary

- based 4.81 46.0 0.10

Avian, acute, dose

- based 1.74 4.2 0.41

Avian, acute, dietary

- based 4.81 33.0 0.15

Avian, chronic, dietary

- based 4.81 1.0 5.06

### 110

### 111