2 dissipation rate of clofentezine on wildlife items, and used the refined half

- life estimate to predict how rapidly terrestrial residues would decline to levels below the chronic toxicity

NOAEC

.

The EPA reviewed Irvita ’s revised assessment and agree s that the residue decline studies on fruit

commodities offer a valid way to refine persistence of clofentezine residues on wildlife food

items. Along these lines, EFED ha s conducted a very similar ref ined assessment in which

decline of residues on terrestrial food items was estimated based on data from a residue decline study with grapes, and characterized how quickly the residues of terrestrial food items would be expected to drop below the chronic av ian toxicity NOAEC (see Section V I .B.1 of the risk assessment)

. The resul ts of this refined assessment are consistent with the one Irvita conducted, and yield s similar conclusions

.

The results of this risk assessment indicate that all outdoor uses of clof entezine can potential ly

lead to direct adverse effects to listed and non

- listed birds and mammals. As birds serve as

surrogates for reptiles and terrestrial

- phase amphibians , risk to these taxa is also a possibility

. R isk to terrestrial vertebrates is associated with sublethal effects on reproduction and growth that may occur with chronic exposure. Acute risk to terrestrial vertebrates is predicted to be minimal. Use of clofentezine is not expected to pose a risk to foraging (adult) bees; however, there is a potential for risk to non

- listed and listed terrestrial arthropods because of adverse effects to reproduction and development. Use of clofentezine is not expected to cause direct or indirect

adverse effects to non

- listed or listed fish

, aquati c invertebrates, or aquatic plants

. Thus, a “no

effect” determination is made for all listed aquatic organisms.

The chronic level of concern (LOC) was exceeded by dietary RQs for birds and by dose

- based RQs (but not dietary

- based RQs) for small and medium

- sized mammals. C lofentezine is moderately persistent in the terrestrial environment and is expected to decline to below toxic

levels approximately one to two weeks after application

. The conc lusion of chronic risk to

mammals is uncertain. Although the chronic dose

- based RQs slightly exceeded the LOC for

small mammals (RQs 1.16

- 1.35) , the predicted peak concentrations on short grass (62.4 mg a.i./kg) is less than the estimated dietary concentra tion in the chronic mammal study at which no adverse effects were observed (400 mg a.i./kg).

A honey bee contact study found that clofentezine is practically nontoxic to adult bees. Based on available acute toxicity data with adult bees , no specific bee acute hazard statement is needed on product labels. Studies with beneficial beetles have found that clofentezine also has low acute toxicity to these species. However, data published in the open literature suggest concern about

clofentezine toxicity to eggs and early life

- stages of bees and other insects

. T he available toxicity data and risk assessment methods do not allow for a precise description of th e chronic

risk to terrestrial insects

. A qualitative evaluation indicates that potential risk of clofentezine use to cause significant brood effects in bees is probably small , but the potential for it to cause adverse effects to listed species of terrestrial arthropods cannot be ruled out

.

Several lines of evidence indicate that clofentezin e has low toxicity to plants. Limit tests conducted with terrestrial plants found no significant phytotoxicity when plants were treated directly at the maximum application rate. A limit study testing the toxicity of a formulated3 product indicates that cl ofentezine is not toxic to green algae at the solubility limit of

clofentezine. Also, clofentezine is routinely applied to a wide variety of plants in greenhouses

, orchards, and tree farms without any reported problems with phytotoxicity or plant damage

i ncidents

. Finally, the only known toxic mode of action of clofentezine (toxicity to eggs and growth inhibition of early life

- stages of invertebrates) is not relevant to plants. Therefore, EPA

concludes that use of clofentezine will not pose risk to eithe r terrestrial or aquatic plants, and is not expected to harm listed species of plants. Thus, a “no effect” determination is made for all

listed plants

.

The two major degradates of clofentezine are 2

- chlorobenzonitrile from direct aqueous photolysis

, and 2

- chlorobenzoic acid (2

- chlorobenzylidine)hydrazide ( AE C593600) from abiotic hydrolysis . Because toxicity data on these degradation products were not available, acute toxicity t o aquatic organisms was estimated based on structural

- activity relationships (SAR) using the ECOSAR program. Toxicity estimates indicated that these degradation products ar e less toxic than parent. Therefore, the conclusion is that a risk assessment cond ucted based on exposure to the parent compound would be protective.

The table below ( Table 1 ) summarizes the risk conclusions for direct effects to listed species.4 Table 1 . Listed Species Risks As sociated with Potential Direct Effects Due to the Applications of Clofentezine.

Listed Plant Taxon Potential Direct Effects

Terrestrial and semi

aquatic plants

– monocots and dicots No effect

Aquatic plants No effect

Listed Animal

Taxon Potential Direct Effects

Acute Notes Chronic Notes

Terrestrial

invertebrates Yes (see

note

1) 1. Adverse effects to terrestrial

in vertebrates are expected to be

limited to those that are exposed as eggs or larval stages. Terrestrial invertebrates exposed as adults are not expected to be affected. ND 2. Based on results from the T

- R EX model, screening

- level RQs exceed the chronic LOC for mammals of all size

classes that eat any food items other than fruit, seeds, or pods. To reduce all of the RQs for chronic risk to listed mammals to less than the chronic LOC, the single application rate would need to be reduced to <0. 1 9 lb

a.i./A

.

3. Chronic risk is uncertain because dietary

- based RQs did

not exceed the chronic LOC

4. Based on results from the T

- R EX model, screening

- level RQs exceed the chronic LOC for birds that eat plants (short grass or broadleaf plants). To reduce all of the RQs

for chronic risk to listed birds to les s than the chronic LOC , the single application rate would need to be

reduced to <0. 1 2 5 lb a.i./A . These results are also applicable for reptiles and terrestrial phases of amphibians. Mammals No

effect Yes (see note s 2 and 3 )

Birds No

effect Yes (see note 3)

Reptiles No

effect Yes (see note

4 )

Amphibians No

effect Yes (see note

4 )

Freshwater fish No

effect No effect

Freshwater

invertebrates No

effect No effect

Mollusks No

data N o data5 Listed Plant Taxon Potential Direct Effects

Estuarine/marine fish No

data No data

Estuarine/marine

invertebrates No

effect No effect6 Based on this screening

- level assessment, there are potential risks of direct effects to listed birds, mammals, reptiles, terrestrial phases of amphibians, and terrestrial arthropods from the use of

clofentezine on some of its registered use sites. Listed species of other taxa, such as terrestrial plants, may also be affected through indirect effects because of the potential direct effects on

listed and non

- listed species. Potential direct effects on listed birds, mammals, reptiles, terrestrial phases of amphibians, and terrestrial arthropods from the use of clofentezine may be associated with modification of Primary Constituent Elements (PCEs) of designated critical habitats, where such designations have been made. However, a t this current stage of the Registration Review process, it is premature to make effects determinations for listed species

until further scientific analysis and refinements are conducted , based on recommendation s received from the National Academy of Sciences’ (NAS) National Research Council (NRC) April 2013 report, available at http://www.nap.edu/catalog.php?record_id=18344 . The NAS report outlines recommendations on specific scientific and technical issues related to the development of pesticide risk assessments that are compliant with the Endangered Species Act (ESA) and the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA).

The EPA alon g 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 implementation plan for assessing risks of pesticides to listed species ahead of the stakeholder workshop held on November 15, 2013. This plan was developed in response to the NAS’ recommendations, including a common approach to risk assessment as a way of addressing scientific differences between EPA and the S ervices. During the workshop, the agencies received feedback from the public on the interim scientific approaches that were developed as part of the initial implementation of the NAS recommendations. These approaches will be jointly implemented and vette d as part of a phased iterative process. Once fully vetted, EPA will further refine the listed species effects determination portion of this risk assessment.

To make effects determinations for individual listed species, useful refinements may include, but are not limited to, analyses of: 1) more detailed, species

- specific ecological and biological data; 2) more detailed and accurate information on clofentezine’s use patterns; and 3) sub

- county level spatial proximity data for the co

- occurrence of potent ial effects areas and listed species and any designated critical habitat. Examples of such refinements are described below.

EFED is currently developing tools that are expected to further refine the assessment and are designed to support effects determinations for individual federally listed species and their designated critical habitats (where applicable). Scientific informat ion obtained from the

Services , and other reliable sources is being collated by EFED to address all currently listed species. Th is information is be ing stored in an Office of Pesticide Programs (OPP) P esticide

R egistration I nformation S yste M (PRISM) liste d species knowledgebase. The listed species knowledgebase consist s of an information repository that houses biological and behavioral information relevant to individual species ( e.g. , habitat, diet, and life history, including specific temporal and spatia l associations) and a document repository that contains supporting documents ( e.g ., USFWS recovery plans) and electronic information ( e.g ., GIS data files). For terrestrial taxa, biological information relevant to the assessment ( e.g ., diet and body weigh t) will be used to parameterize exposure estimates using a method consistent with currently used methods in the

T

- REX and T

- HERPS models.7 Refinements will also include more detailed analyses of the registered uses and specific use patterns that result i n either “Likely to Adversely Affect” (LAA) or “Not Likely to Adversely Affect” (NLAA) determinations for federally listed species. The analyses may include more information on where, when, and how clofentezine is used on all use sites

. Actual usage data (when available) and national land

- cover datasets that indicate potential use sites [ e.g ., N ational

L and C over D ataset (NLCD), C rop land D ata L ayer (CDL)] may be used to support a more refined analysis of where clofentezine is reasonably expected to be used. Similarly, refinements

on the timing of applications and a more in

- depth exploration of agronomic practices for

clofentezine may be included as part of the refinement.

The refinements based on individual species data; a dditional, detailed usage information, when available; and recommendations from the NRC report are expected to help to more accurately identify potential areas of effect and to better inform effects and habitat determinations for listed species and any des ignated critical habitats.8 

# Ecological Risk Assessment in Support of the Registration Review of Clofentezine

Clofentezine
1,2,4,5

- Tetrazine, 3,6

- bis(2

- chlorophenyl)

- CAS No. 74115

- 24

- 5

P.C. Code: 125501

Prepared by: Nicholas Mastrota, Wildlife Biologist Ronald Parker, Senior Environmental Engineer

Approved by: Dana Spatz, Branch Chief Office of Chemical Safety and

Pollution Prevention9 TABLE OF CONTENTS

I. Executive Summary

................................ ................................ ................................ ................ 11

A. Purpose of this Assessment

................................ ................................ ............................ 11

B. Summary of Effects and Risk Conclusions

................................ ................................ .... 11

II. Problem Formulation

................................ ................................ ................................ ....... 16

A. Introduction

................................ ................................ ................................ .................... 16

B. Nature of the Stressor

................................ ................................ ................................ ..... 16

1. Pesticide Type, Class, and Mode of Action

................................ ................................ 16

2. Physical and Chemical Properties

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

C. Stressor Source and Distribution

................................ ................................ .................... 18

1. Pesticide Use

................................ ................................ ................................ ............... 18

2. Pesticide Usage

................................ ................................ ................................ ........... 20

D. Environmental Fate Summary

................................ ................................ ........................ 22

1. Clofentezine

................................ ................................ ................................ ................ 22

1. Degradation Products of Clofentezine

................................ ................................ ........ 24

E. Ecological Effect Summary

................................ ................................ ........................... 25

1. Aquatic Effects

................................ ................................ ................................ ........... 25

2. Terrestrial Effects

................................ ................................ ................................ ....... 31

3. Toxicity of Degradation Products

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

F. Ecosystems Potentially at Risk

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

G. Assessment Endpoints

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

III. Analysis Plan and Conceptual Model

................................ ................................ ............. 38

A. Measures to Evaluate Risk Hypothesis

................................ ................................ .......... 38

B. Conceptual Model

................................ ................................ ................................ .......... 38

C. Risk Hypothesis

................................ ................................ ................................ .............. 39

D. Conceptual Diagram

................................ ................................ ................................ ....... 39

IV. Exposure Analysis

................................ ................................ ................................ ............. 41

A. Use Characterization

................................ ................................ ................................ ...... 41

B. Aquatic Fate and Exposure Characterization

................................ ................................ . 42

1. Fate Characterization

................................ ................................ ................................ .. 42

2. Model Input Parameters

................................ ................................ .............................. 42

3. Estimated Environmental Concentrations

................................ ................................ .. 43

4. Monitoring Data

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

C. Terrestrial Exposure

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

V. Risk Estimates for Non

- Target Organisms

................................ ................................ .......... 46

A. Aquatic Organisms

................................ ................................ ................................ ......... 46

1. Aquatic Animals

................................ ................................ ................................ ......... 46

2. Aquatic Pla nts

................................ ................................ ................................ ............. 49

B. Terrestrial Organisms

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

1. Terrestrial Wildlife

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

2. Terrestrial Plants

................................ ................................ ................................ ......... 52

3. Bees and Other Nontarget Terrestrial Arthropods

................................ ...................... 52

VI. Risk Description and Characterization

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

A. Risk to Aquatic Organisms

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

1. A quatic Animals

................................ ................................ ................................ ......... 5410 2. Aquatic Plants

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

B. Risk to Terrestrial Organisms

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

1. Nontarget Terrestrial Vertebrates

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

2. Terrestrial Arthropods

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

3. Terrestrial Plants

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

C. Ecologi cal Incidents

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

D. Uncertainties, Limitations, and Assumptions

................................ ................................ 63

1. Endocrine Disruption

................................ ................................ ................................ .. 63

2. Uncer tainties Related to Data Limitations

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

3. Uncertainty in Risk Conclusions

................................ ................................ ................ 65

VII. Risk Conclusions

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

VIII. References

................................ ................................ ................................ .......................... 69

APPENDIX A

................................ ................................ ................................ .............................. 71

APPENDIX B

................................ ................................ ................................ .............................. 74

APPENDIX C

................................ ................................ ................................ .............................. 75

APPENDIX D

................................ ................................ ................................ .............................. 76

APPENDIX E

................................ ................................ ................................ .............................. 83

AP PENDIX F

................................ ................................ ................................ .............................. 85

APPENDIX G

................................ ................................ ................................ .............................. 8711 

### I. Executive Summary

A. Purpose of this Assessment

The purpose of this document is to assess the ecological risks of the clofentezine (PC Code 125501) . Clofentezine is an agricultural pesticide used to control mites ( i.e. , an acar i cide). It is

used for mite control on fruit trees, nut trees, Christmas trees

, and ornamental plants grown in greenhouses

. This pesticide was first registered in the United States in 1989 ; thus, i t has not been subjected to evaluation under reregistration. In 2007, the EFED completed a pr oblem formulation for assessing the ecological risks of use of clofentezine (USEPA, 2007).

This assessment evaluates risks that clofentezine’s registered uses may pose to federally listed endangered and threatened (listed) species, as well as to all other non

- target plant and animal (“non

- listed”) species. This risk assessment incorporates the available effects data, and most current modeling and risk met hodologies, some of which may not have been available at the time when previous clofentezine risk assessments were conducted.

B. Summary of Effects and Risk Conclusions

The results of this risk assessment indicate that all outdoor uses of clofentezine have the potential

for direct adverse effects to listed and non

- listed birds and mammals

. As birds serve as

surrogates for reptiles and terrestrial

- phase amphibians , risk to these taxa is also a possibility

. R isk to terrestrial vertebrates is associated with s ublethal effects on reproduction and growth that may occur with chronic exposure. Chronic risk to mammals is uncertain and is expected to be

limited. Acute risk to terrestrial vertebrates is predicted to be minimal. Use of clofentezine is not expected to pose a risk to foraging (adult) bees ; however, there is a potential for risk to listed and

non

- listed terrestrial arthropods because of adverse effects to reproduction and development.

Use of clofentezine is not expected to cause direct or indirect adverse effects to listed and non

listed fish

, aquatic invertebrates, terrestrial plants , or aquatic plants

. Thus, a “no effect”

determination is made for all listed aquatic organisms.

Based on the available data, suspended concentrate (SC) formulated p roducts of clofentezine are slightly to practically non

- toxic to freshwater fish and invertebrates on an acute

- exposure basis

. The limited solubility of the technical grade active ingredient (TGAI) prevented classification of the acute toxicity, but the T GAI was shown to be nontoxic at concentrations that are close to the

aqueous solubility limit

. Acute risk quotients (RQs) for fish and aquatic invertebrates were

below the EPA’s LOC s for listed and non

- listed species. Chronic toxicity tests did not find any adverse effects caused by chronic exposure to fish at concentrations up to the solubility limit

. C hronic exposure to aquatic invertebrates was found to inhibit reproduction ; h owever, the no

observable

- adverse

- effects concentration ( NOAEC ) in these stu dies w as greater than EECs , and

thus the c hronic RQ s are all below EPA’s LOC.

For birds and mammals, clo fentezine is practically nontoxic on an acute exposure basis. The lack of toxicity and the relatively low use rate resulted in acute risk quotients well below the EPA’s level of concern. However, chronic studies identified adverse effects to birds and

mammals. Because the NOAE C of these studies were less than the EEC for some types of birds and mammals, the chronic RQs were above the EPA’s LOC (diet a ry

- based RQs 0.08

– 2.08,12 dose

- based chronic RQs 0.0 1

– 1.35 )

. Specifically, chronic RQs exceeded the LOC for small

birds that feed on plant foliage, and for mammals that feed on plant foliage or arthropods. Thus, all uses of clofentezine are predicted to pose chronic risk to birds, mammals, reptiles, and terrestrial amphibians, and may cause adverse effects to listed species of these taxa. Chronic risk

to mammals is uncertain because the chronic LOC was exceeded only by dose

- based RQs, and only for sma ll to medium mammals feeding exclusively on short grass

. T he peak EECs for short grass were less than the dietary concentration that cause no chronic frank effects in a two

generation rat study

.

A honey bee contact study found that clofentezine is practic ally nontoxic to adult bees. Based on available acute toxicity data with adult bees , no specific bee acute hazard statement is currently needed on product labels. Studies with beneficial beetles have found that clofentezine also has low acute toxicity to these species. However, data published in open literature show that

clofentezine cause s toxicity to eggs and early life

- stages of bees and other insects

. T he avai lable toxicity data and risk assessment methods do not allow for a precise description of th e chronic

risk to terrestrial insects

. A qualitative evaluation indicates that potential risk of clofentezine use

to caus e significant brood effects in bee s is prob ably small , but the potential to cause adverse effects to listed species of terrestrial arthropods cannot be ruled out

.

Because clofentezine is applied only once per year and residues are not very persistent in the environment, chronic effects to terrest rial animals are not expected to be on a scale that would significantly affect their populations. Therefore indirect effect to endangered animals from loss of ecological services, such as diminished seed dispersal of plants, are believed to be

discountable

.

Several lines of evidence indicate that clofentezine has low toxicity to plants. Limit tests conducted with terrestrial plants found no significant phytotoxicity when plants were treated directly at the maximum application rate. A limit study testing the toxicity of a formulated product of clofentezine to green algae also found no observable toxic effects when tested at the high concentration of 100 mg product/L , with the maximum active ingredient concentration assumed to be at the solubility limit ( 34 .2 μg /L ). Although other types of aquatic plants may be more sensitive, and testing with other species of aquatic plants would be needed to draw general conclusions for aquatic plants as a group, t his test indicates that clofentezine is not toxic to green algae at the solubility limit of clofentezine. Also, clofentezine is routinely applied to a wide variety of plants in greenhouses , orchards, and tree farms without any reported problems with phytotoxicity or plant damage incidents

. Finally, the only kno wn toxic mode of action of clofentezine (toxicity to eggs and growth inhibition of early life

- stages of invertebrates) is not relevant to plants. Therefore, EPA concludes that use of clofentezine will not pose significant

risk to either terrestrial or aqu atic plants, and is not expected to harm listed species of plants. Thus, a “no effect” determination is made for all listed plants

.

The two major degradates of clofentezine are 2

- chlorobenzonitrile from direct aqueous photolysis

, and 2

- chlorobenzoic acid (2

- chlorobenzylidine) hydrazide ( AE C593600) from abiotic hydrolysis . Because toxicity data on these degradation products were not available, acute toxicity t o aquatic organisms was estimated based on structural

- activity relationships (SAR) using the ECOSAR program. Additional information on development and use of the ECOSAR13 model is available at: http://www.epa.gov/oppt/newchems/tools/21ecosar.htm. Toxicity es timates indicated that the toxicity of the degradation products would be less than that of the parent. Therefore, the conclu sion is that a risk assessment conducted based on exposure to the parent compound would be protective.

C onclusions about the pote ntial for clofentezine to cause direct effects to threatened and endangered species of various taxa are summarized in Table 2

. Because of limitations in

available tox icity data and assumptions made in the exposure assessments, some uncertainty

exist s in the conclusions described here. (see Section VI.C.)14 Table 2 . Listed Species Risks Associated with Potential Direct Effects Due to the Applications of Clofentezine

.

Listed Plant Taxon Potential Direct Effects

Terrestrial and semi

aquatic plants

– monocots and dicots No effect

Aquatic plants No effect

Listed Animal

Taxon Potential Direct Effects

Acute Notes Chronic Notes

Terrestrial

invertebrates Yes (see

note

1) 1. Adverse effects to terrestrial

in vertebrates are expected to be

limited to those that are exposed as eggs or larval stages. Terrestrial invertebrates exposed as adults are not expected to be affected. ND 2. Based on results from the T

- R EX model, screening

- level RQs exceed the chronic LOC for mammals of all size

classes that eat any food items other than fruit, seeds, or pods. To reduce all of the RQ s for chronic risk to listed mammals to less than the chronic LOC, the single application rate would need to be reduced to <0. 19 lb a.i./A

. 3. Chronic risk is uncertain because dietary

- based RQs did

not exceed the chronic LOC.

4

. Based on results from the T

- R EX model, screening

- level RQs exceed the chronic LOC for birds that eat plants (short grass or broadleaf plants) . To reduce all of the RQ s for

chronic risk to listed birds to less than the chronic LOC, the single application rate would need to be reduced to <0. 1 2 5

lb a.i./A

. These results are also applicable for reptiles and terrestrial phases of amphibians. Mammals No

effect Yes (see note s 2 and 3 )

Birds No

effect Yes (see note

4 )

Reptiles No

effect Yes (see note

4 )

Amphibians No

effect Yes (see note

4 )

Freshwater fish No

effect No effect

Freshwater

invertebrates No

effect No effect

Mollusks No

data N o data15 Listed Plant Taxon Potential Direct Effects

Estuarine/marine fish No

data No data

Estuarine/marine

invertebrates No

effect No effect16 

### II. Problem Formulation

A. Introduction

The problem formulation describes the stressor, the conceptual model used to estimate exposure, and the tools and methods used to assess the potential risk of clofentezine to nontarget organisms. The problem formulation for this assessment was originally provided on February 2,

2007 in a memorandum entitled EFED Problem Formulation for Clofentezine Registration

Review , which is part of the Clofentezine Registration Review Summary Document available in

the Clofentezine Docket 1 . The problem formulation in t his document represents the original problem formulation modified in response to public comments received on the original version.

B. Nature of the Stressor

1. Pesticide Type, Class, and Mode of Action

Clofentezine (3,6

- bis(2

- chlorophenyl)

- 1,2,4,5

- tetrazine ; C AS Registry Number 74115

- 24

- 5 ) is the primary chemical stressor to be considered in this registration review assessment

. Clofentezine belongs to the tetrazine chemical family of pesticides. The structure of c lofentezine

is shown in Fi gure 1

. The only other acaricide in this chemical family is diflovidazin (3

- (2,6

- clorophenyl)

- 6

- (2,6

- diflurophenyl)

- 1,2,4,5

- tetrazine; CAS Registry Number 162320

- 67

- 4)

, which is not a registered pes ticide in the United States

.

Figure 1 . Chemical Structure of Clofentezine

Clofentezine is used as a selective mite growth regulator by acting as an ovicide. According to information provided by the registrant on the label fo r Clofentezine SC (EPA Reg. No. 66222

- 53), clofentezine is active against eggs and early life stages of mites. Yoshida and Fuchs (1989) found that at low doses clofentezine interferes with the development of larval stages of Varroa

mites. T he Insecticide Resistance Action Committee (IRAC ) classifies the mode of action as Group 10, mite growth inhibitors, although the exact site of action is unknown or non

- specified (IRAC, 2012)

. Based on claims made on the product labels, clofentezine is not disruptive to beneficial insects and mites even though it has good residual activity on European red mites,

1 http://www.regulations.gov/#!docketDetail;D=EPA

- HQ

- OPP

- 2006

- 0240

- 000317 McDaniel mites, Pacific spider mites, two

- spotted spider mites, Eriophyes and y ellow spider

mites

.

In addition to considering exposure to the parent

, two degradation products are expected to be formed in the environment in significant quantities and therefore are considered as potential stressors. Degradation of clofentezine in soil and water via aqueous hydrolysis forms 2

- chlorobenzoic acid (2

- chloro benzylidine)hydrazide ( AE C593600) . Degradation of clofentezine in shallow water via aqueous photolysis forms 2

- chlorobenzonitrile. 2

- chlorobenzonitrile has also been observed to form on the fruit and foliage of plants (JMPR, 2007)

. However, QSAR analysis of these degradation products indicate that they both are significantly less toxic than the parent compound and therefore will not contribute substantially as stressors to nontarget organisms (see Section II.E.3.)

2. Physical and Chemical Properties

Clofe ntezine is a crystalline solid with low aqueous solubility and low volatility. The physical and chemical properties of the primary stressor, clofentezine, are shown in

Table 3

. During the preparation of this assessment, the solubility of clofentezine was revised upward to 34.2 parts per billion (ppb) from the previously reported value of “less than 2.0 ppb” based on newly received data 2 . The K

oc value used in earlie r EFED assessments was based on the 2.0 ppb solubility concentration and has therefore also been updated for use in this assessment. The Koc value (516.1 L/kg) was calculated using the USEPA EPI (Estimation Programs Interface) Suite program version 4.10.

Table 3

. Physical and Chemical Properties of Clofentezine

Common Name Clofentezine

IUPAC and CAS Name: 3,6

- bis

- (2

- chlorophenyl)

- 1,2,4,5

- tetrazine

CAS Registry Number 74115

- 24

- 5

Company Code: NC 21314

SMILES Code Clc1ccccc1c1nnc(c2ccccc2Cl)nn1 Empirical Formula C1 4 H 8 C 12 N 4 Molecular Weight, Daltons 303.15 Physical State Crystalline Solid (magenta crystals) Melting Point, ° C 179

- 182
Boiling Point, ° C Not applicable
Solubility in Water , mgL - 1 , 25 ° C

, pH 7 34.2 μg/L

Solubility in Non

- aqueous Solvents, 20 ° C Acetone, 0.5 g/100mL Chloroform, 5 g/100mL Benzene, 0.25 g/100mL

Ethanol, 0.1 g/100mL Hexane, 0.1 g/100mL

Dissociation Constant Not applicable
Vapor Pressure , 25 ° C 9.75 x 10 - 10 mm Hg Henry’s Law Constant 1.14 x 10 - 8 atm

- m 3 mole - 1

Log n

- octanol/water Partition Coefficient (Log K

ow ) 3.1

2 MRID 48210701Van Meter, D. (2010) Clofentezine: Determination of the Water Solubility of a Test Substance. Project Number: 11742/6149. Unpublished study prepared by Springborn Smithers Laboratories.18 C. Stressor Source and Distribution

1. Pesticide Use

Clofentezine is a registered active ingredient of agricultural pesticide products used for control of mite pests, including spider mites and the European red mite. It is registered for use on fruit trees ( apples, apricots

, cherries

, nectarines

, peaches

, pears, and persimmons )

, nut trees ( almonds and

walnuts ) , grapes , Christmas trees, and ornamental plants. It is avai labl e in three formulated products:

• Apollo 42% Ovicide/Miticide (EPA Reg. No. 66222

- 65)

• Apollo SC Ovicide/Miticide (EPA Reg. No. 66222

- 47)

• Clofentezine SC Ovicide/Miticide (EPA Reg. No. 66222

- 53)

All c lofentezine products are formulated as suspension concentrates.

Clofentezine products are diluted with water and applied as a spray onto foliage. For all crops, only one treatment is permitted per growing season , and the maximum application rate is 0.26 lb

ai/A . Treatment is recommended to occur at the first sign of mite activity , which is likely to occur early in the growing season. Spray is typically applied to foliage, although apple trees may be treated as delayed dormant spray, that is

, shortly pri or to the openings of the buds in the spring. Treatment may occur up to the pre

- harvest interval, which varies from 10 days for peaches and nectarines (CA only) to 140 days for persimmons. Crop

- specific details of applicat ion methods are given in Table 4

.19 Table 4 . Use Site and Application Information for Clofentezine

Site Description Products 1 AI Single

Maximum Application

Rate (lb/A) Max. Apps/ Crop Cycle PHI 2
(days) Application

Method s Restrictions

Apples Apollo SC 0.26 1 45 Delayed dormant or foliar spray with low or high volume sprayer No aerial application No chemigation Do not apply within 100 ft

of freshwater or estuarine

habitat

Pears Apollo 42%, Apollo SC 0.26 1 21 Foliar spray with low or high volume sprayer No aerial application No chemigation Do not apply within 100 ft

of freshwater or estuarine

habitat

Stone Fruits: apricot, peach, and nectarine Apollo 42% , Apollo SC 0.26 1 10

- 21 a Foliar spray with low or high volume sprayer No aerial application No chemigation Do not apply within 100 ft

of freshwater or estuarine

habitat

Cherry Apollo SC 0.26 1 21 Foliar spray with low or high volume sprayer No aerial application

No chemigation Do not apply within 100 ft

of freshwater or estuarine

habitat

Grape Apollo 42% , Apollo SC 0.26 1 21 Foliar spray with low or high volume sprayer No aerial application No chemigation

Not in NY Do not apply within 100 ft

of freshwater or estuarine

habitat

Cherry Apollo SC 0.26 1 21 Foliar spray with low or high volume sprayer No aerial application No chemigation Do not apply within 100 ft

of freshwater or estuarine

habitat

Persimmon Apollo 42%, Apollo SC 0.26 1 140 Foliar spray with

low or high volume sprayer No aerial application No chemigation Do not apply within 100 ft

of freshwater or estuarine

habitat

Tree Nuts: Almonds

and Walnuts Apollo 42%, Apollo SC 0.26 1 14

- 30 b Foliar spray with low or high volume sprayer No aerial application No chemigation Do not apply within 100 ft

of freshwater or estuarine

habitat

Christmas Trees Apollo SC 0.26 1 N/A Foliar spray with low or high volume sprayer No aerial application No chemigation

Not in CA Do not apply within 100 ft

of freshwater or estuarine

habitat

Forestry trees grown in greenhouses Clofentezine

SC 0.26 1 N/A Low or ultralow volume sprayer, or

hand

- held sprayer No chemigation Do not apply within 100 ft

of freshwater or estuarine

habitat

Ornamental Plants: nonbearing trees, shrubs, vines and herbaceous plants Clofentezine

SC 0.26 1 N/A Low or ultralow volume sprayer, or

hand

- held sprayer No chemigation Do not apply within 100 ft

of freshwater or estuarine

habitat
1 Apollo 42%: Apollo 42% Ovicide /Miticide (Reg. No. 66222

- 65); Apollo SC: Apollo SC Ovicide/Miticide (Reg.

No. 66222

- 47); Clofe n tezine SC: Clofentezine SC Ovicide/Miticide (Reg. No. 66222

- 53)

2 PHI = Pre

- harvest interval ( number of days prior to harvest that the application may occur.)

a PHI of 10 days is for California only. b PHI of 14 days is for almonds grown in California only.20 2. Pesticide Usage

EPA’s Biological and Economic Analysis Division (BEAD) provided an analysis of national

level usage information using state

- level usage data obtained from various public and proprietary

sources ( Appendix A )

. Table 5 provides recent estimates of the usage of clofentezine on various crops. Crops with the largest use of clofentezine are almonds, apples, cherries, peaches, and walnuts. Crops with low usage (< 500 lbs A.I.) include apricots, grapes, nectarines, pears, and plums. Clofentezine use is not restricted geographically and thus may be used nationwide. States with the greatest usage would be those that greatest production of non

- citrus fruits and nuts, which include California, Georgia, Michigan, New York, South Carolina, and Washingt on.

Table 5 . Screening Level Estimates of Agricultural Uses of C l o fentezine (12 5501 ) (February 1 7

, 201 2 ) 1,2

Crop Lbs. A.I. Percent Crop Treated

Average Maximum

Almonds 3,000 <2.5 5

Apples 1,000 <2.5 10

Apricots <500 <2.5 <2.5

Cherries 1,000 5 10

Grapes <500 <1 <2.5

Nectarines <500 5 10

Peaches 1,000 5 15

Pears <500 5 10

Plums/Prunes + <500 <2.5 <2.5

Walnuts 2,000 5 10

1 All numbers rounded.

<500 Less than 500 pounds of active ingredient

<2.5 Less than 2.5 percent of crop treated

<1 Less than 1 percent of crop treated

+ Crops not known to be listed on active end use product registrations or as Section 18 emergency exemptions when this report was run

2 SLUA data sources include:

USDA

- NASS (United States Department of Agriculture's National Agricultural Statistics Service)

Private Pesticide Market Research California DPR (Department of Pesticide Regula tion)

Figure 2 b elow is a map of agricultural pesticide usage at the Crop Reporting District (CRD) level prepared by BEAD for use in the Environmental Fate and Effects Division documents. These maps are us ed to help visualize where the pesticide being considered is most likely to be used and can be helpful in scenario selection and placing the exposure assessment in

context. CRDs are boundaries created by USDA NASS which are aggregates of counties (USDA, 20 10). Pesticide usage is displayed as average pounds (for the years 2006

- 2010) per 1,000 acres of farmland in a CRD to normalize for the variation in farmland between CRDs. Farmland acreage was obtained from USDA (2007). Usage is based on private market s urveys21 of pesticide use in agriculture (Proprietary Data, 2006

- 2010). The survey data are limited to the states that represent the top 80

- 90% of acreage for the individual crops; therefore, use may be occurring in regions outside the scope of the survey. C RDs showing no usage of pesticides may be due to either the lack of pesticide use in the region or non

- participation in the agricultural surveys. In addition, across the years, there may be variations in the specific crops included in the CRD survey. This may result in a lower annual average for the CRD.

This map displays ratio data (i.e., average pounds per 1,000 acres of farmland) summarized at a very high

- level. Readers are strongly cautioned against trying to over interpret the map

without examinatio n of the underlying data. The underlying data may explain some of the many reasons that a Crop Reporting District may have a high value for a particular active ingredient such as significant acreage (compared with the CRD as a whole) of a crop or crops

wit h a high application rate and frequency of application

.

Proprietary Data. 2006

- 2010
USDA, 2006

- 2010. NASS Crop Reporting Districts. Online: http://www.ers.usda.gov /briefing/arms/resourceregions/resourceregions.htm#nass

. USDA, 2007. Census of Agriculture. Online: http://www.agcensus.usda.gov/Publications/2007/index.asp

.

Figure 2 . Map of c lofentezine u sage by c rop r eporting d istrict (2006

- 2010).22 D. Environmental Fate Summary

1. Clofentezine

Abiotic hydrolysis and direct photolysis in water (clear shallow water) and microbial

- mediated degradation are major ro utes of transformation for clofentezine in the environment. Abiotic hydrolysis is pH and temperature dependent. At 25°C, the hydrolytic half

- lives of clofentezine are 10.4 days (pH 5), 1.4 days (pH 7) and 0.18 days (pH 9). The direct photolysis half

- life i s 8.8 days. Although clofentezine under laboratory conditions appears to be more persistent in aerobic soil (t 1/2 = 4 weeks in clay, 6 weeks in loamy sand and 8 weeks in clay loam), abiotic hydrolysis and/or direct photolysis are likely to control the degradation of clofentezine in the environment. However, extensive mineralization (i.e., CO 2 formation, up to 56% in aerobic soil after one year) was found in the aerobic soil metabolism studies. Thus, mineralization is a n important route of degradation in the environment. The proportion of radioactivity becoming irreversibly bound to

soil increase s with time to between approximately 30% and 50% of applied radioactivity depending on soil type. Levels of 'bound' radioactivity further i ncrease after establishment of

anaerobic conditions.

Clofentezine mobility in soils is uncertain because of the lack of acceptable data to assess its mobility; h owever, the soil

- TLC data suggests that clofentezine may have low

- to

- moderate mobility in soils. Results of a more recent batch

- equilibrium adsorption/ desorption study (the currently accepted methodology) was deemed invalid because of rapid hydrolysis of

clofentezine

. Even though mobility in soil data suggest the potential of clofentezine to partition into the sediment phase, hydrolytic and photolytic processes in the water column are expected to
decrease the amount of clofentezine available for sorption onto the sediment phase. EFED

therefore used the USEPA EPI (Estimation Programs Interface) Suite 3 program to estimate the

Koc (516.1 L/kg)

. Clofentezine has low potential to volatilize from soil or water.

Two aquatic metabolism studies, one a erobic and one anaerobic

, were completed in 2010 and reviewed by the Canadian Pesticide Management Regulatory Agency (PMRA), ( Lentz , 2010 a, 2010b) . Whole system aerobic and anaerobic aquatic half

- lives were calculated for water/sediment sampl es collected from two rivers in the United Kingdom. PMRA

- calculated,

aerobic whole

- system half

- life values are 23.0 and 28.9 days for the Taunton River system and

Weweantic R iver system, respectively. PMRA

- calculated, anaerobic whole

- system half

- life

value s are 44.9 and 33.2 days for the Taunton River system and Weweantic R iver system, respectively. An additional aerobic aquatic study with two surface water/sediment ditch

microcosms was also conducted in the United Kingdom. Aerobic whole

- system half

- life values were 18.2 and 18.9 days for the ditch water

- sandy clay loam sediment study and ditch water

clay loam sediment study, respectively. Studies submitted on the environmental fate of

clofentezine are summarized in Table 6

.

3 http://www.epa.gov/oppt/exposure/pubs/episuite.htm US EPA. [201 2 ]. Estimation Programs Interface SuiteTM for Microsoft® Windows, v 4.10].23 Table 6

. Environmental Fate Data from Submitted Studies on Clofentezine

Environmental Fate Study Data Comments References

835.2130 [Abiotic] Hydrolysis Temperature: 25 ° C

Half

- lives (days)

1.4 (pH 7) pH and temperature dependent MRID: 47192107

MRID: 00159135

835.2240 [Direct] Photolysis

in Water 8.8 days Dark control corrected

half

- life MRID: 00 159136

MRID: 00 159152

835.2410 Photolysis on Soil 31 days 86% of parent remained after 31 days

835.4100 Aerobic soil

metabolism

835.4200 Anaerobic soil

metabolism Temperature: 25 ° C

Half

- lives (days) 4 weeks (clay) 6 weeks (loamy sand) 8 weeks (clay loam)

Qualitative results only Mineralization was high

Biotransformation slows

down under anaerobic conditions; mineralization

is much lower than under

aerobic conditions MRID: 40048101

MRID: 40048102

MRID: 41203701

835.4400 Anaerobic Aquatic

Metabolism Whole

- system half

- life

values are 44.9 and 33.2 days for two rivers in the United Kingdom PMRA Reviewed Study

(2077909) MRID: 48269302

835.4300 Aerobic Aquatic

Metabolism Whole

- system half

- life

values are 23.0 and 28.9 days for two rivers in the United Kingdom

Whole

- system half

- life

values are 18.2 and 18.9 days for two water

sediment ditches in the United Kingdom PMRA Reviewed Study

(2096105) MRID: 48269301

MRID: 47192116

835.1230 Mobility in Soil Koc: 516.1 (L/kg) Calculated Value EPI Suite Ver 4.10

850.1730 Fish

Bioconcentration BCF: 230x (whole body) During the depuration phase, 93% of

accumulated clofentezine

was eliminated , with virtually completely

eliminat ion after 3 days. MRID 405522

- 0124 1. Degradation Products of Clofentezine

The major degradates of clofentezine are 2

- chlorobenzonitrile (CAS No. 873

- 32

- 5) from direct aqueous photolysis and 2

- chlorobenzoic acid (2

- chlorobenzylidine) hydrazide ( AE C593600 )

from abiotic hydrolysis

. The product 2

- chlorobenzoic acid (2

- chlorobenzylidine) hydrazide ) has been identified as an abiotic hydrolysis product. The rate of abiotic hydrolysis is pH and temperature dependent. At 25° C, the half

- lives of clofentezine decrease with increasing pH (10.4 day at p H 5, 1.4 day at pH 7, and 0.18 day at pH 9). The percentage, as percent of the applied radioactivity, of the hydrolysis product AE C593600 increases with increasing pH. At the conclusion of 30 days, it accounted 14

- 23% at pH 5, 38% at pH 7, and 45% at pH 9 . The direct photolysis of clofentezine may involve the hydrolytic product as an intermediate. However, direct photolysis would only be significant in clear, shallow water but not in deep,

turbid water. Except for CO 2 , only traces of other degradates were identified in aerobic soils. See

Table 7 below. Degradate structures are shown in Appendix B.

Clofentezine is degraded in soils under aerobic conditions with a half

- life of approximately 4, 6 and 8 weeks in the clay, loamy sand and clay loam respectively. Degradation of the parent proceeds via hydrolytic cleavage of the tetrazine ring leading to the formation of 2

- chlorobenzoic (2

- chlorofenzylidine) hydrazide. Further degradation leads to the formation of several other

minor metabol ites including 2

- chlorobenzamide and 2

- chlorobenzoic acid with ultimate

mineralization to C O 2 , substantial amounts of which (up to 50% of the applied compound) were

evolved in the first 6 months from aerobic soils. The rate of mineralization to CO 2 was dra stically reduce d under anaerobic conditions and is virtually absent in sterile soils indicating that the activity of soil microorganisms is involved in the degradation of the pesticide in aerobic

soils.

On the surface of treated plants, clofentezine degrades primarily by photolysis , and the only major degradation product formed is 2

- chlorobenzonitrile (JMPR 2007).

Table 7 . Degradation Products of Clofentezine

Environmental Fate

Process Major Degradates Minor Degradates

Hyd r olysis

MRID: 00159135 2

- chlorobenzoic acid (2

- chlorobenzylidene)hydrazide (M1 or VII) 2

- chlorobenzonitrile (M2 or V)

2

- chlorobenzamide (M5 or II) Aerobic Aquatic

Metabolism

MRID: 47192116 2

- chlorobenzoic

- (2

- chlorobenzylidene)

- hydrazide (compound III, AE C593600 ) 2,5

- bis(2

- chlorophenyl)

- 1,3,4

- oxadiazole (NC 12940, compound II)

N',N

- bis(2

- chlorobenzoyl)

- hydrazine (NC 12898, compound IV)

2

- chlorobenzoic acid (NC 233, compound V) Anaerobic Aquatic

Metabolism

MRID: 48269302

PMRA: 2077 9 09 2

- cholorbenzoic acid

2

- chlorobenzoic hydrazone N',N

- bis(2

- chlorobenzoyl)

- hydrazine (NC 12898, compound IV)

2

- chlorobenzoic acid (NC 233, compound V)

Aerobic Soil Metabolism 2

- chlorobenzoic (2

- chlorofenzylidine) 2

- chlorobenzamide25 MRID: 00159138 hydrazide

2

- chlorobenzoic acid Direct Aqueous Photolysis

MRID: 00159136 2

- chlorobenzonitrile

2

- chlorobenzaldehyde

E. Ecological Effect Summary

1. Aquatic Effects

Table 8 contains the available acute toxicity data that the EPA use d to assess the risk s of

clofentezine to aquatic animals and plants. F reshwater fish serve as a surrogate to assess potential risk to aquatic

- phase amphibian s as well as fish

. Acute toxicity studies show that

clofentezine is not acutely toxic to freshwater fish or invertebrates at aqueous concentrations up to the solubility limit

. Because of the limited solubility of clofentezine, te sting with the TGAI could not be conducted at much above the solubility limit

. T esting at higher concentrations w as possible when tests were conducted with a typical end

- use product (TEP), Apollo ® 50 SC

, which forms a colloidal suspension in water

. Although nominal concentrations were very high, the dissolved component of clofentezine in these studies is believed to be near the solubility limit

of 34.2 μg/L , while the remainder of the active ingredient would exist as suspended particles

. (Measured c oncentrations of clofentezine reported in the study reports are believed to be unreliable because the test solution samples were not filtered or centrifuged before analysis.) While the findings of all three available acute toxicity tests with fish agree i n showing that the

LC 50 is greater than the solubility limit of clofentezine, the TEP study conducted with the rainbow trout using Apollo 50 SC (MRID 40568202) was used as the definitive acute fish toxicity study in this risk assessment because it is the o nly one of the three studies that was

classified as acceptable ). This TEP study showed that the 96

- hr LC 50 is >24 mg product/ L

, classifying the product as no more than slightly toxic to fish. The limited solubility prevents

classification of the acute tox icity of the active ingredient, but the TEP study shows that it does

not cause mortality or sublethal effects at concentrations up to the solubility limit.

Three acute toxicity tests are available with the water flea, a freshwater crustacean. Two studie s conducted with the TGAI were classified as supplemental because the lab failed to test up to the solubility limit of clofentezine (both studies) and failed to filter or centrifuge samples before measuring the test concentrations (MRID 00 105919)

. T he TEP study conducted using Apollo 50 SC (MRID 4056820 3 ) was used in this risk assessment as the definitive acute freshwater

invertebrate toxicity study because it is the only one of the three studies that was classified as acceptable ). This TEP study with the water flea showed that the 48

- hr LC 50 of the product is

> 100 mg product /L

, classifying the product as practically non toxic to freshwater invertebrates.

In acute aquatic tests conducted with Apollo® 50 SC, t he mean measured concentration of the

test concentrations far exceeds the solubility limit of clofentezine . Since there is no indication that the test concentrations were filtered before chemical analysis , th e reported measure d

concentrations are believed to represents concentration s of undissolved suspended solids as well as the dissolved component of clofentezine. The concentration of dissolved clofentezine in these26 tests was assumed to be at equilibrium at near the solubility limit, and thus the LC 50 values for

the active ingredient w ere expresse d as greater than the solubility limit (> 34.2 μg a.i./L)

.

A toxicity study Selenastrum capricornutum conducted with a formulated product, Apollo 50

SC , found that clofentezine had no significant adverse effects on growth and reproduction of green algae a t product concentrations as high as 100 mg product /L (MRID 47200501)

. This study was classified as supplemental because the test duration (92 hr) was shorter than the recommended duration (96

- 120 hr)

, and because the study report was missing some informat ion on methodology , including the photoperiod, the age of the algal inoculum, test vessel fill volumes, and a description of the dilution water . Also, at the higher test concentrations, cell growth was greatly stimulated. According to the study authors, the stimulation presumably

occurred because the parent compound was degrading into nitrogenous products which added nutrients to the growth medium, similar to fertilizer. As with the acute freshwater invertebrate tests, the concentration of clofentezine wa s not expected to exceed the solubility limit, and thus the reported endpoints which exceeded the solubility limit were adjusted to the solubility limit of

34.2 μg ai /L . Despite these shortcomings, this study was sufficient to show that clofentezine is

not toxic to green algae up to the solubility limit of clofentezine.

Data are not available on the toxicity of clofentezine to vascular aquatic plants. However, based on the mode of action of this pesticide ( i.e. , as an acaricide), the lack of phytotoxicity observed in terrestrial vascular plants, the lack of reported plant damage incidents or warnings about phytotoxicity to sensitive plants, adverse effects to aquatic vascular plants are not expected.

Table 8

. Most Sensitive Acute Toxicity Values for C lofentezine to Aquatic Animals and Plants

Taxonomic Group, Study Type Surrogate Species Toxicity Citation

MRID Acceptability

Classification

Fish

Freshwater fish,

Acute study with

TGAI Rainbow Trout ( Oncorhynchus mykiss ) 96

- hr LC 50 > 14.6 μg ai /L (No mortality or adverse

effects were observed; highest test level was close to the solubility limit) MRID

40568201 Supplemental 1

Freshwater fish,

Acute study with

Apollo 50 SC

(50% AI) Rainbow Trout ( Oncorhynchus mykiss ) 96

- hr LC 50 >
24 mg product /L

96

- hr LC 50 > 34.2 μg ai /L 2 MRID

40912101 Acceptable

Bluegill Sunfish ( Lepomis macrochirus ) 96

- hr LC 50 > 10.1 mg product /L

96

- hr LC 50 > 34.2 μg ai /L 2 MRID

00159120 Supplemental

Aquatic Invertebrates

Freshwater

invertebrates with

TGAI

, Acute Water flea ( Daphnia magna ) 48

- hr LC 50 > 1.15 μg ai /L MRID

40568203 Supplemental 3

Water flea ( Daphnia magna ) 48

- hr LC 50 > 0.80 μg ai /L MRID

00105919 Supplemental 4

Freshwater

invertebrate

, Acute study with

Apollo 50 SC

(50% AI) Water flea ( Daphnia magna ) 48

- hr LC 50 > 100 mg product /L

48

- hr LC 50 > 34.2 μg ai /L 2 MRID

40568202 Acceptable (for TEP)

Aquatic Plants27 Taxonomic Group, Study Type Surrogate Species Toxicity Citation

MRID Acceptability

Classification

Algae

, study with

Apollo 50 SC

(50% AI) Green algae ( Selena s trum capricornutum ) Formulation : 9 6

- hr I C 50 > 100 mg /L

NOAEC : 100 mg /L LOAEC: >100 mg/L

Active Ingredient:

96

- hr I C 50 > 34.2 μg /L 2

NOAEC : 34.2 μg /L 2

LOAEC: > 34.2 μg/L 2 MRID

47200501 Acceptable

1. This study was classified as supplemental because the study failed to establish the NOAEC and did not test to either 100 mg a.i ./L or the solubility limit of clofentezine.

2. Results for the active ingredient that were calculated based on reported measured concentration are not reported here because the analytical analysis is believed to have measured undissolved solids suspended in the suspension concentrate formulation as well as the dissolved component

. Instead, endpoints with reported active ingredient concentrations greater than the solubility limit were adjusted to greater than the solubility limit (> 34.2 μg a.i./L).

3. This stud y was classified as supplemental because the study failed to establish the NOAEC and did not test to either 100 mg a.i./L or the solubility limit of clofentezine.

4. This study was classified as supplemental because the test was conducted at a nominal concent ration well above the solubility limit of clofentezine, and centrifuging or filtering of undissolved test material was not used prior to measurement of the concentration of test material.

Table 9 contains available data on the chronic toxicity of clofentezine to fish and aquatic invertebrates. Two studies have been conducted on the effects of clofentezine on the early life stage of freshwater fish. The first study conducted with the rainbow trout (MRID 42735201) found no adverse effects when the active ingredient was tested at concentrations up to 6 μg ai/L. ( Testing was conducted at 6 μg ai/L based on a solubility study conducted in 1985 which

erro neously reported the solubility of clofentezine as less than 2 μg/L; however, this study was later found to be invalid and a new solubility study yielded a solubility limit of 34.2 μg/L

. ) This study was classified as supplemental because the concentration of the solvent use (acetone) was not reported, and a solvent control group was not included in the study. A second study was conducted with the fathead minnow and using the formulated product Apollo® 50 SC (MRID 47192101). This study was conducted using a flow

- through system, and results are presented

based on the time

- weighted average of measured concentrations of the active ingredient. Since

clofentezine forms a colloidal suspension in this formulated product , the study was able to test higher concentra tions than in the TGAI study . This study found no adverse effects on growth, hatching success, or time to hatch at test concentrations as high as 979 μg ai/ L, establishing a

NOAE C at this level

.

Four aquatic invertebrate life

- cycle studies have been subm itted for clofentezine. Deficiencies in all of these studies resulted in all being classified as supplemental . However, the study submitted which tested the toxicity of the TGAI to Daphnia magna (MRID 42523901) is adequate as a limit test because it demo nstrates that clofentezine would not cause chronic toxicity to this species at concentrations expected in natural water

. This test found no chronic effects were caused by a single test concentration of 26.2 μg ai /L , which is close to the solubility

limit of clofentezine at pH 7 ( 34.2 μg/L ). Another life

- cycle test was recently submitted which tested the chronic toxicity of the TGAI to the mysid ( Americamysis bahia ) , a saltwater28 crustacean (MRID 48342701). This study indicates that the mysid is more sensitive to

clofentezine than Daphnia magna

. Female reproduction was significantly impaired at concentrations as low as 3.6 μg a.i./L , whereas growth and survival were not adversely affected

at any test concentr ation

. These results suggest that the toxic mode of action in the target organisms, i.e.

, toxicity to eggs and early growth stages, may also result in similar toxicity to some aquatic inv ertebrates.

In addition to the TGAI studies, t wo submitted life

- cycle studies and one open literature study provides information on the chronic toxicity to the water flea ( Daphnia magna ) of Apollo 50 SC, a suspension containing 43.5% clofentezine

. Both of these studies were conducted according to

the O ECD test guideline for testing reproduction with Daphnia sp. (Guideline No. 211), which differs from the comparable EPA test guideline (850.1300) , and one study (MRID 47192117) had numerous guideline deviations. T hus

, b oth of the submitted life

- cycle stud ies were classified as supplemental. Both of these studies found that reproduction was a more sensitive chronic endpoint than growth or survival. One study (MRID 47192117) was deficient beca use solubility challenges made the exposure concentrations uncer tain, measured concentrations in aged samples were highly variable, and the study failed to establish an NOAEC for reproduction. This study found that all test concentrations significantly reduced the number of offspring produced per female. Percent redu ctions (relative to the control) ranged from 8.25% at 0. 10 mg product /L to 17.5% at 15 mg product /L. A second study (MRID 4719 2 102) had a similar setup to
the first except that the test vessels contained sediment, the test was conducted under static

condit ions rather than under static

- renewal conditions, and the test material was applied to overlying water at either Day 0 or at Day 6. Reproduction was again the most sensitive endpoint. When the test material was applied on Day 0, significant reductions in o ffspring produced per female were observed at all test levels. Percent reductions ranged from 14.6% at 0. 275 mg product /L to 19.2% at 2. 6 5 mg product /L. As the results of this study were similar to the results of the study without sediment, the presence of sediment did not appear to substantially affect the reproductive toxicity of clofentezine to Daphnia magna

. The study without sediment (MRID 47192117) tested lower test concentrations than did the study with sediment, and there by

established the lower LOAEC for reproductive toxicity of 10 0 μg product/L, or 44 μg a

. i

. /L.

N one of the studies established a NOAEC.

For chronic risk assessment, the reproductive LOAEC of 44 μg a.i./L for Daphnia magna (MRID 47192117 ) was selec ted as the endpoint to assess chronic risk to freshwater invertebrates,

and the NOAEC of 1.7 μg/L ( MRID 48342701 ) was selected to assess chronic risk to saltwater

invertebrates.

Table 9

. Chronic Toxicity of C lofentezine to Aquatic Animals

Taxonomic Group, Study Type Surrogate Species Toxicity Citation

MRID Acceptability

Classification

Fish

Freshwater F ish, Early Life

- Stage Rainbow Trout ( Oncorhynchus mykiss ) NOAE C : 6 μg ai/L

LOAE C : > 6 μg ai/L MRID

4 2735201 Supplemental 1

Freshwater fish, Early Life

- Stage with Apollo 50 SC

(50% AI) Fathead Minnow ( Pimephales promelas ) NOAE C : 979 μg ai/L

LOAE C : >979 μg ai/L MRID

47192101 Acceptable29 Taxonomic Group, Study Type Surrogate Species Toxicity Citation

MRID Acceptability

Classification

Freshwater Invertebrates

Freshwater

invertebrates

, Life

- Cycle with TGAI (99.8% purity) Water flea ( Daphnia magna ) NOAEC : 26.2 μ g ai /L

LOAEC : > 26.2 μ g ai /L MRID

42523901 Supplemental 2

Freshwater

invertebrates

, Life

- Cycle study with Apollo 50 SC

(50% AI) Water flea ( Daphnia magna ) Survival

NOAEC : 15 m g product /L (6.5 mg ai/L)

LOAEC : >15 m g/L (>6.5 mg ai/L)

Reproduction

NOAEC : <1 0 0 μg product /L (<4 4 μg ai/L)

LOAEC : 1 0 0 μg product /L (4 4 μg ai/L) (Reduced nu mber of offspring per female ; 8.25%

reduction at lowest test level )

Growth

NOAEC : 1 0 0 μg product /L ( 4 4 μg ai/L)

LOAEC : 35 0 μg product /L (15 0 μg ai/L) (Reduced length ) MRID

47192117 Supplemental 2

Freshwater

invertebrates

, Reproduction study with Apollo 50 SC (50% AI) Water flea ( Daphnia magna ) Reproduction

NOAEC : 0.1 2 m g product /L (0. 06 mg ai/L)

LOAEC : 1.2 m g/L ( 0.60 mg ai/L) (Reduced nu mber of offspring ) Eco Ref #

12662

Barber and

Barrett (1993) Qualitative

Freshwater

invertebrates

, Life

- Cycle study,

water with sediment system with Apollo

50 SC (50% AI) Water flea ( Daphnia magna ) Survival

NOAEC : 2.50 mg product /L (1.04 m g ai /L )

LOAEC : > 2.50 mg product /L ( > 1.04 m g ai /L )

Reproduction

NOAEC :

< 0.275 mg product /L ( < 0.114 m g ai /L )

LOAEC : 0. 275 mg product /L ( 0. 114 m g ai /L ) (Reduced nu mber of offspring when exposed to <

24

- hr old neonates )

Growth

NOAEC : 2.50 mg/L MRID

47192102 Supplemental 330 Taxonomic Group, Study Type Surrogate Species Toxicity Citation

MRID Acceptability

Classification (1.04 m g ai /L )

LOAEC :

> 2.50 mg/L ( > 1.04 m g ai /L )

Saltwater Invertebrates

Estuarine/marine

invertebrates,

Life

- Cycle Mysid shrimp (Americamysis bahia) Survival

NOAEC : 29 μg ai /L

LOAEC : >29 μg ai /L

Reproduction

NOAEC : 1.7 μg ai /L

LOAEC : 3.6 μg ai /L (Reduced nu mber of offspring per female ) MRID

48342701 Supplemental 4

1. This study was classified as supplemental because a solvent control was not included in the study design, the solvent concentration was not reported, and the study report lacked reporting of sublethal effects.

2. This study was classified as supplemental because the study did not identify the NOAEC and LOAEC for

clofentezine , the amount of disolved AI in the test solutions was uncertain, and the control mortality was excessive (12.5%).

3. This study was classified as supplemental because it was conducted according to the protocol of OECD Guideline 202, which deviates significantly from the OSPP Guideline for freshwater invertebrate life

- cycle testing, 850.1300. Furthermore, the study failed to establish an NOAEC for reproductive effects.

4. This study was classified as supplemental because the diluter syst em delivered inconsistent concentrations of active ingredient during the study. Results are based on time

- weighted average concentrations.

Barber and Barrett (1993) conducted a study to test their hypothesis that the chronic toxicity to Daphnia magna exhi bited by clofentezine products formulated as suspension concentrate is the consequence of particles in the formulated product causing physical interference with filter feeding rather than the result of intrinsic toxicity of the active ingredient. They test ed the reproductive response of Daphnia magna when exposed to three concentrations of Apollo 50 SC (50% clofentezine), concentrations of inert polyvinyl toluene (PVT) latex beads that were equivalent to the Apollo 50 SC concentrations in terms of particle concentrations, and a formulated blank (Apollo 50 SC formulation without the active ingredient) at a rate equivalent to the highest test concentration. The concentrations of Apollo 50 SC tested were 0.12, 1.2, and 12 mg/L, which is equivalent to 0.060, 0. 60, and 6.0 mg ai/L. The result showed reproduction performance was not significantly affected (relative to the control) by the formulated blank, but was significantly reduced by both the Apollo 50 SC and the PVT bead treatments. The NOAE C

for Apollo 50 S C treatment was 0.12 mg product/L (0.06 mg ai/L). The reproductive response of Daphnia magna in this study was less sensitive to Apollo 50 SC in this study than a life

- cycle study submitted to the EPA ( MRID 47192117) in that the NOAE C and LOAE C were greate r, although the dose

- response of the number of offspring per female were similar in both studies. For example, MRID 47192117 found a n 8.25% reduction in this endpoint at a concentration of 0.044 mg ai/L, and this study found a 9.8% reduction at the slight ly higher concentration of 0.060 mg ai/L.

Barber and Barrett (1993) found that exposure of Daphnia magna to supposedly inert PVT latex beads also caused reductions in reproductive performance. The reduction in number of offspring31 produced per adult was generally similar in test solutions of Apollo 50 SC and mixtures of water and latex beads with identical partic ular concentrations ( Table 10 ). The reproductive respo nse

w as similar between comparable treatments with the exception that the reduction in offspring production was somewhat greater in the latex bead mixture than the Apollo 50 SC at the highest partic ular concentration (3.7 x 10 9 L - 1 ) . According to the stud y authors, this similarity in the reproductive responses “suggest s that the effect of Apollo 50 SC was not due to any intrinsic toxicity of the formulation, but rather a consequence of its particular concentration. ” This may explain why reproductive toxic ity was observed in daphnids exposed to the SC formulated product, but not when exposed to technical grade clofentezine.

Table 10 . Comparison of reproductive response of Daphnia magna exposed to Apollo 50 SC

and PVT latex beads wi th identical particle concentrations (from Barber and Barrett, 1993)

Particle

Concentration (particles/L) Product

Concentration (mg/L) AI Concentration (mg ai/L) Number of Offspring per

Adult Percent Change in No. Offspring/Adult Apollo 50

SC Latex

beads Apollo 50

SC Latex

beads

Formulated blank 0 0 35.8 35.8

-- -- 3.7 x 10 7 0.12 0.06 32.3 33.8

- 9.8

- 5.8

3.7 x 10 8 1.2 0.60 31.4 31.9

- 12.6

- 10.9

3.7 x 10 9 12 6.0 29.7 23.0

- 17.1

- 35.9

2. Terrestrial Effects

Table 11 pr esents the acute toxicity data that the Agency use d to assess the risk of clofentezine to
terrestrial animals and plants. B irds act as surrogates for reptiles and terrestrial

- phase amphibi ans when data on those species are not available. Acute oral and subacute dietary studies with the northern bobwhite and mallard all showed that clofentezine has low acute toxicity to birds. These studies classify clofentezine as practically nontoxic to b irds. Acute toxicity studies

with mammals show that clofentezine is practically nontoxic to mammals on an acute basis

. Studies on dermal and inhalation toxicity in mammals found no mortality at the doses tested, indicating low acute toxicity through these exposure routes (Toxicity Category III or IV).

An acute contact test with adult honey bee s determined the L D 50 to be >1500 mg a

. i

. /L. This study was classified as supplemental because exposure was expressed as the concentration of the solution sprayed onto the bee, rather than the amount of active ingredient applied per bee, per the EPA test guideline. Nevertheless, t his study is sufficient to show that use of clofentezine products is expected to pose minimal hazard to adult bees from acute contact exposure. Also, a n available acute oral toxicity honeybee study determined the acute oral toxicity of clofentezine to

be >20 μg/bee. Based on the classification scheme used by the EPA for the acute contact studies, this toxicity level would classify clofentezine as practically nontoxic to bees.

Yoshida and Fuchs (1989, Eco Ref. No. 154863) provides additional information on the developmental toxicity of clofentezine to the honey bee. In one test, the authors exposed the

bees in the 5 th instar (L5) stage with topical applications of 10μl clofente zine solutions, with test concentrations ranging from 0.05 to 500 μg/bee. Failure of the larvae to seal the cell was used as32 a measure of mortality. Elevated levels of mortality w ere observed at treatment concentrations of 50 μg a.i./bee and greater. Hi gh levels of abnormal pupa development (over 40%) w ere observed at concentrations of 25 μg a.i./bee and greater. This test established an NOAEL of 5 μg a.i./bee for toxicity from acute contact exposure. In a second bee larvae feeding study, pollen

mixtur es, containing 1.0 to 1000 mg a.i./kg clofentezine were fed to larvae bees of nucleus colonies. Bee larvae were in various stages of development from L1 to L5, and were grouped into three groups (L1 and L2, L3 and L4, and L5) to measure effects with expos ure to various developmental stages. In all developmental groups, a bnormal bee pupas were observed in

groups fed pollen with a clofentezine concentration of 1000 mg a.i./kg. Results on mortality were uncertain because no statistical analyses were conduct ed, but mortality of bees exposed at the L1 level appeared to be elevated at clofentezine concentrations of 10 mg a

. i

. /kg and greater. Based on mortality, the NOAEL for the feeding study was 1.0 mg a.i./kg pollen.

One submitted report (MRID 471921

- 22) and two papers published in the open literature (Samsoe

- Peterson, 1993, Olszak, 1999) provide further information on the toxicity of clofentezine to terrestrial beetles (Order Coleoptera). MRID 471921

- 22 found no significant

adverse effects on egg survival, larvae survival, or pupae emergence in the ladybird beetle ( Coccinella septempunctata ) when they were exposed to 100 and 200 g a

. i

. /ha, which corresponds to 0.089 and 0.18 lb a

. i

. /A, respectively. The spray volumes used were 500 and 1000 L/ha, which are e quivalent to 54 and 110 gal/A, respectively. Olszak (1999) studied the toxicity of clofentezine and 29 other pesticides to a nother ladybird beetle, Adalia bipunctata . An immersion study using 0.027% (270 ppm) concentration of clofentezine caused relativel y low levels of mortality (0

- 15%) of various developmental stages from L 1 to adult. Clofentezine exposure caused greater effects on reproduction. When eggs were immersed, percent hatch ranged from 76.9 % for 1

- day

- old eggs to 45.0% for 3

- day

- old eggs. When females were immersed, egg production was approximately 300 eggs/female, compared to approximately 650 eggs/female in the control. Beetles were also reared on leaves which had been treated with a 0.027% clofentezine solution and allowed to age for 2 hours to 21 days. Exposure of the second instar resulted in 0% to 47% mortality, and exposure to the forth instar resulted in 0% to 37% mortality

. Samsoe

- Peterson (1993) studied the effects of Apollo 50 SC on the survival and reproduction of the rove beetle, Aleochara bilineata . The beetles were sprayed with a concentration of clofentezine of 0.02% at a rate of 6 μl/cm 2 , which the authors claim is equivalent to exposure to spray at the maximum application rate. The exposure resulted in no mortality of adults a nd no significant reduction in egg production, but caused a 28% reduction in percent hatching of eggs relative to the control. Together these papers show that clofentezine is not toxic to adult beetles, but is toxic to eggs and early life

- stages.
One study is available on the phytotoxicity of clofentezine. In a Tier 1 vegetative vigor study with the formulated product Apollo 50 SC, application of clofentezine at the maximum application rate of 0.26 lb a.i./A resulted in no observable adverse effects to 4 di cot species and 2 monocot species (MRID 47192103 ). This indicates that foliar exposure to clofentezine is not

toxic to emerged plants at environmentally

- relevant concentrations. Toxicity related to effects on seed germination and plant emergence is unknow n.33 Table 11 . Acute Toxicity of C lofentezine to Terrestrial Species

Taxonomic

Group

, Study Type Surrogate Species Toxicity ( e xpressed as AI) Citation

MRID Acceptability

Classification

Birds 1

Birds 1 , Acute Oral Bobwhite quail ( Colinus vi r ginianus ) LD 50 > 7500 mg a

. i

. /kg

- bw MRID

00105913 Acceptable

Mallard ( Anas platyrhynchos ) L D 50 > 3000 mg/kg

- bw MRID

00105914 Acceptable

Birds 1

, Subacute Dietary Bobwhite quail ( Colinus vi r ginianus ) L C 50 > 19,900 mg/kg

- diet MRID

00159117 Acceptable

Mallard ( Anas platyrhynchos ) L C 50 > 20,700 mg/kg

- diet MRID

00159118 Acceptable

Mammals
Mammals, Acute

Oral Laboratory rat ( Rattus norvegicus ) LD 50 > 3230 mg a

. i

. /kg

- bw MRID 00159071 Acceptable ( Minimal )
Mammals, Acute

Oral , with 80% wettable powder

formulation Laboratory rat ( Rattus norvegicus ) LD 50 > 4000 mg a

. i

. / kg

- bw MRID 00105904 Acceptable ( Minimal )

Mammals, Acute

Oral , with 50% wettable powder

formulation Laboratory rat ( Rattus norvegicus ) LD 50 > 5000 mg/ kg

- bw

LD 50 > 2500 mg a

. i

. / kg

- bw MRID 00105903 Acceptable ( Guideline )

Mammals, Acute Inhalation, 80% wettable powder

formulation Laboratory rat ( Rattus norvegicus ) LC 50 > 11.35 mg/kg

- bw

LC 50 > 9.08 mg a

. i

. /kg

- bw MRID 001 59072 Acceptable ( Minimal )

Mammals, Acute Dermal, Apollo

SC formulation (42% a.i. ) Rabbit LC 50 > 2 0,050 mg/Kg

- bw

LC 50 > 16,040 mg a

. i

. /Kg

bw MRID 00 105905 Acceptable ( Minimal )

Beneficial Insects

Bee, acute contact Honey bee ( Apis mellifera ) LD 50 (contact)

> 1500 mg a

. i

. /L MRID 00159121 Supplemental 2

Bee, acute oral Honey bee ( Apis mellifera ) LD 50 ( oral ) > 20 μg/bee MRID 00159121 Supplemental (Nonguideline)
Beneficial insect, with Apollo® 50 SC (51.7% a

. i

. ) Ladybird Be e tle ( Coccinella

septempunctata ) LC 50 > 200 g a

. i

. /ha NOAEC: 200 g a

. i

. /HA MRID 47192122 Supplemental (Nonguideline)

Terrestrial Plants

Terrestrial Plants,

Tier 1 Vegetative Vigor with Apollo 50 SC (49.8% a.i.) Dicots (carrot, cucumber, pea, and canola) IC 25 : >0.26 lb a.i./A

NOAEL: 0.26 lb a.i./A

LOAEL: > 0.26 lb a.i./A MRID 47192103 Supplemental 3

Monocots (chufa and oat) IC 25 : >0.26 lb a.i./A

NOAEL: 0.26 lb a.i./A

LOAEL: > 0.26 lb a.i./A 1. Birds represent surrogates for terrestrial

- phase amphibians and reptiles

. 2. This study was classified as supplemental because the acute contact LD 50 was expressed as a concentration (mg/L) rather than th e amount of a

. i

. per bee. 3. This study was classified as supplemental because it tested only six species (4 dicots and 2 monocots) and did not measure survival or plant height.34 Table 12 provides results of chronic toxicity tests conducted with birds and mammals. The

northern bobwhite was the most sensitive bird species. A dietary concentration of 9 0 mg a

. i

. /kg significantl y reduced embryo viability, establishing the NOAE C at 30 mg a

. i

. /L. For mammals,

a rat 2

- generation reproduction test established the chronic NOAEL at 20 mg/kg day

. Daily dietary doses up to 20 mg a.i./ kg

- BW day resulted in no frank effects on survival, reproduction, or development in the F1 and F2 generations. For adult male and nonlactating female rats, this daily dose is approximately equivalent to a dietary concentration of 400 mg/kg

- diet.

Table 12 . Chronic Toxicity of Clofentezine to Terrestrial Species

Taxonomic

Group, Study Type Surrogate Species Toxicity ( e xpressed as AI) Citation

MRID Acceptability

Classification

Birds 1

, Reproduction Northern bobwhite ( Colinus vi r ginianus ) NOAE C : 30 mg a

. i

. /kg

- diet

LOAE C : 90 mg a

. i

. /kg

- diet ( reduced embryo viability) MRID

42776101 Acceptable

Mallard ( Anas platyrhynchos ) NOAE C : 270 mg a

. i

. /kg

- diet

LOAE C : >270 mg a

. i

. /kg

diet MRID

42776102 Acceptable

Mammals, 2

-

Generation Reproduction Laboratory rat ( Rattus norvegicus ) Frank effects

NOAE C : 20 mg/kg

- BW day

LOAEC : > 20 mg/kg

- BW day ( no effects on survival, reproduction, or development )

Other effects

NOAE C : 20 mg/kg

- BW day

LOAEC : > 20 mg/kg

- BW day ( minimal entrilobular hepatocyte hypertrophy in

males ) MRID 00147844 Acceptable

1. Birds represent surrogates for terrestrial

- phase amphibians and reptiles

.

3. Toxicity of Degr a dation Product s

The two major degradates of clofentezine are 2

- chlorobenzonitrile and 2

- chlorobenzoic acid (2

- chlorobenzylidine)hydrazide ( AE C593600)

. Photolysis of clofentezine forms 2

- chlorobenzonitrile in soil and shallow water, and on plant surfaces. Hydrolysis of clofentezine

forms 2

- chlorobenzoic acid (2

- chlorobenzylidene) hydrazide (AE C 593600) i n soil and water

. Transformation of clofentezine into both of these products involves cleavage of the triazine ring

in the center of the molecule. As t his substantially changes the shape of the molecule

, th ese products would not likely retain the ovicid al activity of the parent compound

. However, they may have toxicity through other mechanisms

.

Because no studies on the toxicity of A E C5936 00 are available, the ECOSAR (ver. 1.0) program was used to estimate toxicity of this compound t o aquatic organisms based on quantitative structural

- activity relationships ( Q SAR)

. Table 13 present s the estimated acute and chronic toxicity threshold values based on relationships with hydrazines and amides , and based35 on relationships with all uncharged compounds (neutral organics)

. The predicted toxicity of this degr a dation product is less than that of the parent compound with the exception of the predictions for toxicity to algae based on hydrazines. Except for green algae, conversion of the some of the parent compound to the degr a dation product would decrease the overall hazard to nontarget organisms, compared to if the applied active ingredient remained as the parent compound. Thus, because the terrestrial and aquatic risk assessments assumed 100% of the applied active ingredient remained as the parent compound, the risk assessments are protective. Any conversion of the parent compound to the degr a dation produ ct would only reduce risk, with the possible exception of risk to algae if the ECOSAR predictions based on hydrazines are

correct.

Table 13 . Predicted Toxicity of the Degradation Product AE C593600 to Aquatic Organisms Based on Qua ntitative

– Structural Relationships.

Organism Duration Endpoint Predicted Toxicity (μg/L) Hydrazines Amides Neutral Organics Acute Toxicity

Fish 96

- hr LC 50 344 3,320 16,800 Daphnid 48

- hr LC 50 7,230 2,970 11,400 Green Algae 72

- 96 hr EC 50 0.0549 274 8,470 Chronic Toxicity

Fish chronic NOAEC 26 20 1,540 Daphnid chronic NOAEC 65 39 1,330 Green Algae chronic NOAEC 0.0137 490 3,910

ECOSAR appears to predict AE C593600 may have very high toxicity to green algae based on the toxicity of hydrazine (N 2 H 4 ). Hydrazine, without a carboxyl group or any other functional groups attached, is highly toxic to green algae (144

- hr EC 50 0.041 μg/L) ; however, semicarbazides which are substituted with various functional group have been found to be generally much mor e toxic to green algae by 5 to7 orders of magnitude (EC 50 range from 2.5 to

190 mg /L ) (Clements 1996) . Also, as indicated by the predicted results in Table 13 , amides are generally much less toxic to algae. Because A E C593600 is hydrazide, making it an amide as well as a hydrazine, and because it has two chloro

- phenyl functional groups attached, we do not believe that the predictions of high toxicity to green algae ba sed on simple hydrazine are appropriate for predicting the toxicity of this compound. We expect the toxicity of A E C593600 to be closer to the SAR prediction made based on amides, 490 μg/L. Thus, we do not expect A E

C593600 to be more toxic to algae than the parent, and formation of this degradation product is not expected to pose a risk to aquatic plants above what is predicted by the current aquatic risk

assessment.

ECOSAR (ver. 1.0) was also used to estimate toxicity of 2

- chlorobenzonitrile t o aquatic organisms. By comparing this compound to similar neutral organics, ECOSAR predicts relatively low acute and chronic toxicity for all evaluated aquatic animals and plants ( Table 14 )

. Toxicity of this degradation product is therefore expected to be much less than that of the parent. As a check of the predictive ability of ECOSAR for compounds related to clofentezine, ECOSAR was used to predict the aquatic tox icity of clofentezine itself, and these predictions were compared to the measured toxicity values. ECOSAR predictions of clofentezine were based on all uncharged compounds (neutral organics). All predicted acute and chronic toxicity

thresholds were well a bove the solubility limit of clofentezine ( 34.2 μg/L ) . The predictions36 therefore agreed with the acute toxicity measurements for fish and aquatic invertebrates, and the

measured toxicity for green algae, in predicting no observable toxicity at concentrati ons up to the solubility limit. ECOSAR failed to predict the chronic toxicity related to reproductive and developmental endpoints observed in freshwater and saltwater invertebrates

. This is likely because related chemicals with this specific ovicide mode of action were not present in the set of chemicals used to develop ECOSAR.

Table 14 . Predicted Toxicity of the Degradation Product 2

- Chlorobenzonitrile to Aquatic Organisms Based on Quantitative

– Structural Relationships.

Organism Duration Endpoint Predicted Toxicity ( m g/L) Neutral Organics Acute Toxicity

Freshwater Fish 96

- hr LC 50 73.0

Saltwater Fish 96

- hr LC 50 100 Daphnid 48

- hr LC 50 42.3 Mysid 96

- hr LC 50 63.8 Green Algae 96 hr EC 50 21.7 Chronic Toxicity

Freshwater Fish 30

- days NOAEC 7.70

Saltwater Fish chronic NOAEC 11.8 Daphnid chronic NOAEC 5.05 Mysid chronic NOAEC 5.22 Green Algae chronic NOAEC 8.57

F. E cosystems Potentially at Risk

Ecosystems potentially at risk from the use of clofentezine include the orchards, vineyards, nurseries, and tree farms to which it is directly applied, and nearby terrestrial and aquatic ecosystems. Ecological receptors are both terrestrial and aquatic nontarget organisms that inhabit or move through these ecosystems. Terres trial ecosystems which may be at risk are those that may be exposed by direct application of the pesticide and those in adjacent areas which may be exposed from spray drift. Terrestrial animals and plants that live in or feed in exposed habitats may be at risk. Aquatic ecosystems that may be exposed include ponds, streams, wetlands, and other water bodies receiving runoff and/or spray drift from applications to agricultural sites. As clofentezine is used in coastal locations, aquatic ecosystems potential ly at risk include salt marshes and estuaries. Aquatic organisms potentially at risk include fish, aquatic invertebrates, and plants living in the water column and sediment.

G. Assessment Endpoints

Assessment endpoints include reduced survival of individua ls or reproduction within populations and/or adverse effects to communities. Organisms potentially exposed include terrestrial and aquatic plants and animals. Potential effects are determined through testing of surrogate representatives within those tax onomic groups, or from other related taxonomic groups. Assessment endpoints and toxicity data used to evaluate the assessment endpoints are identified

in Table 15

.37 Table 15 . Summary of A ssessment E ndpoints and M easures of E ffects for S creening L evel R isk

A ssessment of C lofentezine

Assessment Endpoint Measurement Endpoint

1. Survival, reproduction, and growth of birds (Birds also serve as surrogates for reptiles and terrestrial phase amphibians in that birds are generally more sensitive than species from these other taxonomic groups.) •Acute oral LD 50 values, subacute 5

- d dietary LC 50 values

•Avian reproduction study NOAEC

2. Survival, reproduction, and growth of mammals •Acute oral mammalian LD 50 values

•Mammal 2

- generation reproduction study NOAEC or NOAEL

3. Survival and reproduction of freshwater fish and

invertebrates (Fish also serve as surrogates for aquatic phase amphibians because fish are generally more sensitive than amphibians) •Freshwater fish 96

- h LC 50 and early life

- stage NOAEC

•Freshwater invertebrate 48

- h EC 50 and life cycle NOAEC

4. Survival and reproduction of estuarine/marine fish and

invertebrates •Estuarine/marine fish 96

- h LC 50 and early life

- stage NOAEC*

•Estuarine/marine invertebrate 96

- h LC 50 (clofentezine) and life cycle NOAEC*

*Currently, no acute or reproduction s tudy using clofentezine has

been submitted. W ithout these data, freshwater data could be used as surrogate for these tests.

5. Perpetuation of non

- target terrestrial plants (crops and

non

- crop species) •Monocot and dicot seedling emergence EC 25 and NOA EC, or EC 05 (clofentezine TEP) *

•Monocot and dicot vegetative vigor EC 25 and NOAEC, or EC 05 (clofentezine TEP) *

* Currently, no terrestrial plant study using clofentezine TEP has

been submitted. W ithout terrestrial plant data, assumptions of sensitivity would be made based on mode of action and other

available information.

6. Survival of beneficial insect populations (Terrestrial invertebrates are represented by the honey bee) •Honey bee acute contact LD 50 *

* Various effects levels o n toxicity to eggs and larval stages from studies published in the open literature are also considered in characterizing risk to beneficial insects.

7. Maintenance and growth of aquatic plants from standing crop or biomass •Aquatic plant growth and biomass 96

- h EC 50 * •Aquatic plant growth and biomass 96

- h NOAEC or EC 05 *

*Currently, no aquatic plant study using clofentezine has been submitted. Without aquatic plant data, assumptions of sensitivity

would be made based on mode of action and other available

information.

LD 50 : Lethal dose to 50% of test population

LC 50 : Lethal concentration to 50% of the test population

EC 50 : median effect concentration is the concentration that results in a specific effect (e.g., immobility, emergence) to 50% of the exposed test population

EC 05 and EC 25 : the concentration that results in a specific effect to 5% and 25%, respectively, of th e exposed test population.

NOAEC = No observed adverse effect concentration38 

### III. Analysis Plan and Conceptual Model

A. Measures to Evaluate Risk Hypothesis

In order to estimate risks of clofentezine exposures in aquatic and terrestrial environments, all exposure modeling and resulting risk conclusions were made based on the maximum application

rate , which is 0.26 lb a

. i

. /A for all uses

. As only one application may be made per season, no more than on e ‘season’ of crop production in a year is expected, and clofentezine is not highly persistent in the environment, there is no need to model repeated application

. Tier I I aquatic estimated environmental concentrations (EEC) were generated with the USEPA Pesticide Root Zone Model (PRZM) and Exposure Analysis Modeling System (EXAMS) models using the

EXPRESS shell

, ( http://www.epa.gov/ceampubl/swater/express ). The model used to produce

terrestrial EEC s on food items is T

- REX (version 1.5) . The model used to derive EECs relevant to terrestrial and wetland plants is TerrPlant (ver. 1.2.2) . These models are parameterized using relevant reviewed registrant

- submitted environmental fate data. For more infor mation on EPA models, http://www.epa.gov/pesticides/science/models_db.htm

.

In the preliminary risk assessment, acute and chronic EECs are compared to acute and chronic toxicity endpoint to estimate risk to nontarget animals and plants, and to determine if the risk

exceed the EPA’s levels of concern

. Toxicity levels are based on t he most sensitive toxicity endpoints from surrogate test species . Acute endpoints are based on mortality, and ch ronic endpoints are based on adverse effects on growth, reproduction

, or survival. Measures of effect

are obtained from a suite of studies conducted with a limite d number of surrogate species.

B. Conceptual Model

Spraying of agricultural and ornamental pla nts will release clofentezine into the terrestrial

environment. Most of the clofentezine spray will settle on plants and soil at the target site , while

some will drift off site and contaminate nearby terrestrial and aquatic habitats . That which settles on the target site may remain on treated plants , percolate into the soil, or runoff with

surface water. Terrestrial animals will be exposed when they feed on contaminated food on treated sites and on sites contaminated by spray drift . Spray drift, s urface runoff , and movement of soil particles with sorbed residues will cause in contamination of aquatic habitats , exposing aquatic animals and plants

. Little of the applied residues are likely to volatilize , and thus long

range atmosphe ric transport is unlikely

. In soil, water, and sediment, hydrolysis and photolysis

of the parent clofentezine will form 2

- chlorobenzoic acid (2

- chlorobenzylidine) hydrazide and/ or 2

- chlorobenzonitrile , thereby exposing terrestrial and aquatic organisms to these degradation products.

Clofentezine is not expected to bioaccumulate in fish in appreciable amounts. A bioconcentration study with the bluegill sunfish measured a low whole

- body BCF of 230x and depuration is virtually complete after 3 days (MRID 40 5522

- 01) . Furthermore, the log K

ow of clofentezine is only moderate (3.1), and the compound degrades rapidly in the environment through photolysis and hydrolysis (half

- lives less than 7 days). Therefore, exposure of clofentezine to piscivorous wildlife th rough consumption of fish is expected to be a very minor route of exposure and will not be investigated in this risk assessment.39 EPA’s Screening Imbibition Program (SIP) was used to conduct a screen

- level assessment for

risk to terrestrial wildlife from d rinking of water contaminated with clofentezine. This screening tool determines preliminary risk quotients (RQs) for birds and mammals assuming they are drinking from a water source in which the clofentezine concentration was equal to the solubility

limit . This program found that acute and chronic RQs from this route of exposure will be no

more than 0.001, indicating that drinking water is not s significant route of exposure for terrestrial wildlife. This finding wa s expected based on the low solubility of clofentezine ( 34.2 μg/L). Therefore, drinking water was not included as a route of exposure in the conceptual

model for clofentezine.

EPA’s Screening Tool for Inhalation Risk (STIR, version 1.0) was used to screen for the potential of risk to birds an d mammals from inhalation of clofentezine from foliar application.

STIR calculates risk based on a theoretical upper bound estimate of inhalation exposure based on the maximum application rate, vapor pressure, and molecular weight. Based on the results of the STIR model, inhalation is not a significant route of exposure for terrestrial wildlife. This finding was expected based on the low vapor pressure of clofentezine (9.75 x 10 - 10 mmHg). Therefore,

inhalation was not included as a route of exposure in the conceptual model for clofentezine.

C. Risk Hypothesis

T he Agency will employ the following risk hypothesis when assessing ecological risks of the use

of clofentezine :

Clofentezine

, when used in ac cordance with current labels, may result in contamination of ecosystems and adverse effects upon the survival, growth, and reproduction of non

target terrestrial and aquatic organisms, including organisms that are f ederally

- listed as threatened and endange red species.

D. Conce ptual Diagram

The potential exposure pathways and effects of clofentezine are depicted for aquatic

environments in Figure 3 and for terrestrial environments in Figure 4

.40 Figure 3

. Conceptual m odel d epicting stressors, exposure pathways, and p otential effects to

a quatic a nimals and p lants from the u se of clofentezine

.41 Figure 4

. Conceptual m odel d epicting stressors, exposure pathways, and p otential effects to
terrestrial a nimals and p lants from the u se of clofentezine

.



### IV. Exposure Analysis

A. Use Characterization

Registered u se s of clofentezine are described in detailed in section I.C of this document.

Clofentezine is used for mite control in orchard s of various non

- citrus tree crops fruit trees (including apples, apricots

, cherries

, nectarines

, peaches

, pears, and persimmons ), nut trees (almonds and walnuts), and grapes. Clofentezine is also used on Christmas tree farms

. All of these outdoor uses are evaluated in this ecological risk assessment. Indoor use of clofentezine on ornamental plants in greenhouses is not expected to release significant contaminants into the

environment and is therefore not considered in this a ssessment. Information on the usage of clofentezine in the United States is provided in Appendix A.42 B. Aquatic Fate and Exposure Characterization

1. Fate Characterization

Abiotic hydrolysis and direct photolysis in water (clear shallow water) and microbial

- me diated degradation are major routes of transformation for clofentezine in the environment. Abiotic hydrolysis is pH and temperature dependent. At 25°C, the hydrolytic half

- lives of clofentezine are 10.4 days (pH 5), 1.4 days (pH 7) and 0.18 days (pH 9). The direct photolysis half

- life is 8.8 days. Although clofentezine under laboratory conditions appears to be more persistent in aerobic soil (t 1/2 = 4 weeks in clay, 6 weeks in loamy sand and 8 weeks in clay loam), abiotic hydrolysis and/or direct photol ysis are likely to control the degradation of clofentezine in the environment. However, extensive mineralization (i.e., CO 2 formation, up to 56% in aerobic soil after one year)

was found in the aerobic soil metabolism studies. Thus, mineralization can al so be included as a

route of transformation in the environment. The proportion of radioactivity becoming irreversibly bound to soil increase s with time to between approximately 30% and 50% of applied radioactivity depending on soil type. Levels of 'bound' radioactivity further i ncrease after

establishment of anaerobic conditions.

T he USEPA EPI (Estimation Programs Interface) Suite program was used to estimate the Koc for clofentezine and its potential mobility in soils. Based on the predicted value of 516.1 L/kg

, clofentezine is not expected to be very mobile in the environment

. The low aqueous solubility of clofentezine ( 34.2 μg/L) also limits its transport in grou nd and surface water. Clofentezine has low potential to volatilize from soil or water.

Whole system aerobic and anaerobic aquatic half

- lives were calculated for water/sediment samples collected from two rivers in the United Kingdom. W hole

- system half

- lif e values are 23.0 and 28.9 days for the Taunton River system and Weweantic R iver system, respectively.

PMRA

- calculated, whole

- system half

- life values are 44.9 and 33.2 days for the Taunton River

system and Weweantic R iver system, respectively.

2. Model Input Parameters

The physical/chemical and environmental fate properties for clofentezine used as the input parameters in modeling to estimate potential aquatic environmental concentrations are

summarized in Table 16 , which also take into account the required 100

- foot buffers, as stated on product labels

.

Table 16

. Input Parameters Used in PRZM/EXAMS Modeling to Estimate Aquatic

Concentration s of Clofentezine

Input Parameter (Symbol; Unit) Value for Clofentezine

Molecular Weight 303.15

Vapor Pressure (torr ) 9.75 x 10 - 10 , mm Hg

1.31 x 10 - 7 , Pa43 Henry’s constant (25 o C) 1.14 x 10 - 8 atm

- m 3 mole - 1

Solubility in Water ( m g/L at 2 5 o C) 0.0342

Hydrolysis Half

- life (t 1/2 at pH 7) 1.4 days

Aquatic Photolysis Half

- life ( days; t 1/2 at pH 7) 8.8 days

Aerobic Soil Metabolism [ upper 90 th percentile confidence

bound on the mean half

- life value ( t 1/2 ; 28, 42 and 56 days)] 57.2 days

Aerobic Aquatic Metabolism Half

- life ( t 1/2 ; days) [ Entire water/sediment system ; upper 90 th percentile confidence bound

on the mean half

- life value ( t 1/2 ; 28.9

, 23.0 ,18.2,18.9 ) ] 25.8 days

Anaerobic Aquatic Metabolism Half

- life ( t 1/2 ; days) [ Entire water/sediment system ; upper 90 th percentile confidence bound

on the mean half

- life value ( t 1/2 ; 44.9 and 33.2) ] 57.1 days

Average Organic Carbon

- Water Partitioning Coefficient (K

oc ; mL/g) (EPI Suite Program Version 4.10) 516.1

PRZM Scenarios and Application Dates North Carolina Apple: Oct 11 New York Grape: Oct 1 Calif. Almond: Sept 30 Oregon Christmas Trees: Dec 17

Spray Drift Fraction ( 100 foot buffer ) (From GENEEC2) 7.37

3. Estimated Environmental Concentrations

Potential aquatic exposures were estimated using the Tier II models Pesticide Root Zone Model (PRZM v3.12.2, May 12, 2005) and Exposure Analysis Modeling System (EXAMS v2.98.04.06, April 25, 2005) coupled with the input shell pe5.pl ( Nov. 16, 2006). PRZM s imulates fate and transport of pesticides on the agricultural field and EXAMS simulates the fate and resulting daily concentrations of pesticides that reach an adjacent water body through runoff, erosion, and spray drift. Simulations are based on crop

- spec ific scenarios developed to represent environmental conditions at sites at high runoff

- vulnerability for pesticide transport to surface waters from a particular crop. Exposure is estimated using a standard pond scenario based on a 10

- ha field bordering a 1

- ha water body , 2

- m deep (20,000 m 3 ) with no outlet. Using appropriate scenarios linked with local meteorological data, the model is run for 30 years with the reported EECs representing the values that are expected once every ten years, based on the thirty years of daily values generated during the simulation. A dditional information about model assumptions and

uncertainties , input guidance, and scenario metadata are available at the EPA’s water modeling website, http://www.epa.gov/oppefed1/models/water/

.

Tier I I aquatic EECs for registered outdoor uses on crops are l isted in Table 17

. The use rate and application method is similar for all uses, but different scenarios were used for fruit trees, grapes, nut trees, and Christmas tr ees to best represent these use sites. The complete output from the

PRZM/EXAMS runs conducted is provided in Appendix C

.

Table 17 . Tier I I Surface Water Estimated Environmental Concentrations ( EECs ) for Registered

Uses of C lofente zine44 Crop/Use Site Model Scenario Peak μg/L (ppb) 21

- day μg/L (ppb) 60

- day μg/L (ppb)

Fruit Trees (1 ground application @ 0.26 lb a.i./A) North Carolina Apples (NC1App

- P) 3.34 0.406 0.145

Grapes (1 ground application @ 0.26 lb a.i./A) New York Grapes (NY2Gra

- P) 1.02 0.170 0.0742

Almonds and Walnuts (1 ground application @ 0.26 lb a.i./A) California Walnuts (CA1Wal

- P) 0. 454 0.0705 0.0265

Christmas Trees (1 ground application @ 0.26 lb a.i./A) Oregon Christmas Trees

OR1Xma

- P 0.964 0.123 0.0430

4. Monitoring Data

There were no reported detections of clofentezine residues in ground water at the time that the Pesticides in Ground Water Data Base was published, in 1992 (USEPA, 1992). This may be because very few ground

- water samples have been anal yzed for clofentezine residues in the United States and because it has limited usage areas and crops. Clofentezine were not included in the suite of analyses conducted in the USEPA's National Survey of Pesticides in Drinking Water Wells (USEPA, 1990). Cl ofentezine also was not included in the USGS NAQWA program. No surface water monitoring was located.

The California Department of Pesticide Regulation ( CDPR) surface water database ( http://www.cdpr.ca.gov/docs/emon/surfwtr/surfcont.htm ), USGS NAWQA surface and ground water database ( http://infotrek.er.usgs.gov/apex/f?p=136:1:0::NO::: ), Pesticide Data Program ( http://www.ams.usda.gov/AMSv1.0/ams.fetchTemplateData.do?te mplate=TemplateG&navID= &rightNav1=&topNav=&leftNav=ScienceandLaboratories&page=PDPDownloadData/Reports& resultType=&acct=pestcddataprg ), and the USGS/EPA Reservoir Data Program were evaluated for available monitoring data. No detects were seen for clofente zine in any of these databases; however, it is important to note that these sources did not appear to be looking for clofentezine in water bodies. As a result, no detects does not necessarily mean that clofentezine is not found in surface and ground water sources.

C. Terrestrial Exposure

Terrestrial exposure estimates for avian and mammalian risk assessments were derived using the

T

- REX model (version 1.5, 3/22/2012). All terrestrial EECs for clofentezine are based on a single foliar application at the maxi mum rate of 0.26 lb a

. i

. /A. I nput parameters used in this modeling are given in Table 18

. The default value of 35 days was used as the foliar half

- life

because the di stribution of chemical

- specific half

- lives for clofentezine is uncertain. As only one application was modeled, the peak EEC which are used to calculate acute and chronic risk quotients occurs immediately application. Therefore, the selection of the foliar half

- life has no effect on the calculated terrestrial EECs or RQs. Because clofentezine degrades fairly rapidly through photolysis, and the foliar half

- life may be considerably less than the default value of 3545 days, the persistence of foliar residues ma y be less than predicted by the T

- R EX model. Implications of this potentially more rapid dissipation from terrestrial food will be explored in the Risk Description and Characterization section (Section VI).

Table 18

. Input Parameters for T

- REX Modeling for All Uses of Clofentezine

Input Param e ters Value S ource Single Application Rate (lb a.i./A) All Uses : 0.26 EPA Reg. No.

Foliar Half

- life 35 days Default value 1

Number of Applications (Interval between Applications, days) All Uses : 1 EPA Reg. No. 66222

- 47, 66222

- 53, 66222

- 65

Avian Oral LD 50 7500 mg/kg

- bw (bobwhite) MRID 00105913

Avian Dietary LC 50 19,900 mg/kg

- bw (bobwhite) MRID 001 59117

Avian NOAEC 30 mg/kg

- diet ( bobwhite ) MRID 42776101

Mammal LD 50 3200 mg/kg

- bw ( rat ) MRID 00159071

Mammal NOAEC 50 mg/kg

- d iet (rat) MRID 44399146

1 The foliar half

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

.

Terrestrial EECs for dietary

- based calculations are given in Table 19 , a nd terrestrial EECs for

dose

- based calculations are given in Table 20

. Complete output from the T

- Rex Model is provided in Appendix D.

Table 19

. Dietary

- Based Clofentezine EEC Values

Dietary Item Dietary

- Based EEC (mg/kg)

Short Grass 62.40

Tall Grass 28.60

Broadleaf Plants 35.10
Fruits, Pods, and Seeds 3.90 Arthropods 24.4446 Table 20 . Avian and Mammalian Dose

- Based Clofentezine Upper Bound EEC Values

Application Rate (crop) Size Class (g) Avian Dose

- Based EECs (mg/kg

- bw)

Dietary Item

Short Grass Tall Grass Broadleaf

Plants Fruits &

Pods Arthropods Seeds

Avian
One application @ 0.26 lb a.i./A (all uses) 20 71.07 32.57 39.98 4.44 27.83 0.99

100 40.53 18.57 22.80 2.53 15.87 0.56

1000 18.14 8.32 10.21 1.13 7.11 0.25

Mammalian
One application @ 0.26 lb a.i./A (all uses) 15 59.46 27.27 33.47 3.72 23.30 0.83

35 41.12 18.85 23.13 2.57 16.10 0.57

1000 9.53 4.37 5.36 0.60 3.73 0.13



### V. Risk Estimates for Non

- Target Organisms

A. Aquatic Organisms

1. Aquatic Animals

Table 21 provide s RQs for risk to fish from acute and chronic exposures associated with uses of clofentezine. Because of the very low solubi lity of clofentezine, all of the acute and chronic toxicity endpoints are nondefinitive

, in that the tests were only able to show that the LC 50 value is greater than the highest test concentration, or in the case of tests with the TEP, are greater than

the solubility limit of clofentezine ( 34.2 μg/L). Because the toxicity values are expressed as “greater than” inequalities, the RQs calculated from them are expressed as “less than” inequalities, indicating the upper bound of the RQ

. For fish, acute risk qu otients were shown to be less than EPA’s LOC for risk to nonendangered species (0.5) and the LOC for potential

adverse effects to endangered species (0.05) for all use sites except fruit trees. For use on fruit

trees , the RQ for fish w as only shown to be less than 0.10, and therefore was not demonstrated to

be less than the LOC for endangered species. However, since no treatment

- related mortality or adverse effects observed in the acute toxicity test with the TG A I at close to the solubility limit (MRID 40 568201), or with the TEP at nominal concentrations exceeding the solubility limit (MRIDs 40912101 and 00159120), the EPA concludes that acute exposure from all uses of clofentezine, including on fruit trees, will not result in adverse effects to listed spe cies of fish (see Section VI.A.1 for more discussion). For risk from chronic exposure, RQs for all use sites were less than 1, and therefore the RQ did not exceed the LOC for chronic risk (1) for all uses.

For fish, t oxicity test ing with the rainbow trout found no mortality or adverse effects at exposure at or near the solubility limit (MRID 00159120)

. Therefore , the EPA concludes that clofentezine

will not cause adverse acute effects at concentrations that would occur in natural wa ters. Therefore, a “no effect” conclusion is made for fish for all uses, including use on fruit trees.47 Since acute and chronic toxicity tests with saltwater fish are not available, the conclusions for freshwater fish are assumed for saltwater fish as well, although these conclusions are uncertain.

In summary , the EPA concludes that all registered uses of clofentezine pose minimal risk to freshwater and saltwater fish, and are not expected to harm threatened or endangered species of

fish.

Table 21

. Acute and Chronic Risk Quotients for Fish
Crop (Application

method) Exposure Type Habitat Type Toxicity ( μg a.i./L) EEC ( μg a.i./L) RQ

Fruit Trees (1 ground application @ 0.26 lb a.i./A) Acute Freshwater > 34.2 3.34 < 0.10

Saltwater N/A 3.34 N/A 1

Chronic Freshwater > 34.2 0.1 45 <0.01

Saltwater N/A 0.1 45 N/A 1

Grapes (1 ground application @ 0.26 lb a.i./A) Acute Freshwater > 34.2 1. 02 < 0.0 3

Saltwater N/A 1.02 N/A 1

Chronic Freshwater > 34.2 0.0 742 <0.0 1

Saltwater N/A 0.0742 N/A 1

Almonds and

Walnuts (1 ground application @ 0.26 lb a.i./A) Acute Freshwater > 34.2 0.454 <0.01

Saltwater N/A 0.454 N/A 1

Chronic Freshwater > 34.2 0.0265 <0.01

Saltwater N/A 0.0265 N/A 1

Christmas Trees (1 ground application @ 0.26 lb a.i./A) Acute Freshwater > 34.2 0.964 < 0.03

Saltwater N/A 0.964 N/A 1

Chronic Freshwater > 34.2 0.0 430 <0.01

Saltwater N/A 0.0 430 N/A 1

1 No toxicity data are available for saltwater fish; however, based on the very low toxicity observed in freshwater fish, the RQ for saltwater fish is also expected to be well below 0.01.

Table 22 provides RQs for risk to aquatic invertebrates from acute and chronic exposures associated with uses of clofentezine. Because of the very low solubility of clofentezine, all of the acute toxicity endpoints for aquatic in vertebrates are nondefinitive . A s for fish

, the acute toxicity tests were only able to show that the EC 50 value is greater than the highest test concentration or the solubility limit of clofentezine ( 34.2 μg/L). Because the toxicity values are expressed as “greater than” inequalities, the RQs calculated from them are again expressed as “less than” inequalities. Acute toxicity tests using the TGAI were supplemental and were

conducted at levels less than t he solubility limit. The acceptable acute toxicity test using the formulated product (MRID 40568202) was therefore used for RQ calculations. Since the

nominal test concentrations in this test were much greater than the solubility limit of

clofentezine , t he concentration of dissolved clofentezine is assumed to have been close to the solubility limit of 34.2 μg a.i./L. As f or fish, acute risk quotients were found to be less than EPA’s LOC for risk to nonendangered species (0.5) and the LOC for potential ad verse effects to endangered species (0.05) for all use sites except fruit trees. For use on fruit trees, the RQ was only shown to be less than 0.10 and therefore do es not preclude possible adverse effects to48 endangered species. For risk from chronic expo sure, RQs for all use sites were less than 1, and therefore the RQ did not exceed the LOC for chronic risk (1) for any use.

In the acceptable acute toxicity study with daphnid (MRID 40568202), no more than 3 out of 30 (10%) of daphnids were immobilized at any test concentration, which equals the number that

were immobilized in the negative control. At the highest test concentration (nominal concentration of 100 mg a.i./L), there were 2 daphnids immobilized, less than in the control.

Because the number of immobilized daphnids in the treatments did not exceed the number in the control, they are assumed to be incidental and not treatment related. Other than immobilization, no sublethal effects were observed at any test concentration. Because exposure to da phnids at the solubility limit did not result in any significant adverse effects (i.e., effects greater than in the control), the EPA concludes that all uses of clofentezine, including use on fruit trees, will cause

no acute toxic effects to threatened and endangered species of aquatic invertebrates.

Chronic studies with clofentezine found that it does negatively a ffect the reproduction of freshwater and saltwater invertebrates, but only at concentrations above the chronic EECs predicted for registered uses. Because the chronic NOAEC for both freshwater and saltwater

crustacean s are greater than the chronic EEC s
, all of the chronic RQ s are less than 1.0, and

therefore does not exceed the EPA’s chronic LOC.

In summary, the EPA concludes that all registe red uses of clofentezine pose minimal risk to

freshwater and saltwater invertebrates , and are not expected to cause any adverse effects to threatened or endangered species of invertebrates

.

Table 22 . Acute and Chronic Risk Quotients for Aquatic Invertebrates

Crop (Application

method) Exposure Type Habitat Type Toxicity (μg a.i./L) EEC (μg a.i./L) RQ

Fruit Trees (1 ground application @ 0.26 lb a.i./A) Acute Freshwater > 34.2 3.34 < 0.10

Saltwater N/A 3.34 N/A 1

Chronic Freshwater 44 0.406 0.01 2

Saltwater 1.7 0.406 0. 24

Grapes (1 ground application @ 0.26 lb a.i./A) Acute Freshwater > 34.2 1. 02 < 0.03

Saltwater N/A 1. 02 N/A 1

Chronic Freshwater 44 0. 170 <0.01 2

Saltwater 1.7 0. 170 0. 1 0

Almonds and

Walnuts (1 ground application @ 0.26 lb a.i./A) Acute Freshwater > 34.2 0. 454 <0.01

Saltwater N/A 0.454 N/A 1

Chronic Freshwater 44 0.0 705 <0.01 2

Saltwater 1.7 0.0705 0.04

Christmas Trees (1 ground application @ 0.26 lb a.i./A) Acute Freshwater > 34.2 0.964 < 0.03

Saltwater N/A 0.964 N/A 1

Chronic Freshwater 44 0.1 23 <0.01 2

Saltwater 1.7 0.123 0.0 749 1 No toxicity data are available for saltwater invertebrates; h owever, based on the very low toxicity observed in

freshwater invertebrate , the RQ for saltwater invertebrate is also expected to be well below 0.01. 2 The RQ is uncertain because it is based on the LOAEL rather than the NOAEL

.

2. Aquatic Plants

An algal toxicity test with the T EP (MRID 47200501) found no observable adverse effects to green algae at nominal concentrations up to 100 mg product/L

. The test concentrations of dissolved clofentezine in this study are unknown because the samples used for chemical analysis were not filtered before analys is. However, the dissolved concentrations in the test solutions are expected to be close to the solubility limit, and thus the study demonstrated that clofentezine does not adversely affect the growth of green algae up to the aqueous solubility limit of 34 .2 μg a.i./L. Based on this, the RQs for both endangered and nonendangered species of nonvascular aquatic plants are well below the LOC of 1 for all uses of clofentezine ( Table 23 ).

L ack of data on the toxicity of clofentezine to vascular aquatic plants prevent s quantitative

assessment of risk to vascular aquatic plants. Vascular plants would need to be over 9.7 times more sensitive than the tested nonvascular aquatic plant (green algae) for the RQ to exceed the

LOC. S ince clofentezine does not have a known mechanism of action that is relevant to toxicity to plants, exhibited low phytotoxicity in a study of terrestrial vascular plants, has no reported problems with pla nt safety

, and is expected to occur in natural water at only very low

concentrations , use of clofentezine is not expected to pose significant risk to vascular aquatic plants.

Table 23 . Risk Quotients for Aquatic Plants

Crop (Application method) Plant Type Toxicity (μg a.i./L) EEC (μg a.i./L) RQ

Non

Endangered Endangered

Fruit Trees (1 ground application @ 0.26 lb a.i./A) Vascular N/A 3.34 N/A N/A

Non

- vascular IC 50 : > 34.2

NOAEC: > 34.2 3.34 < 0. 1 0 <0. 10

Grapes (1 ground application @ 0.26 lb a.i./A) Vascular N/A 1. 02 N/A N/A

Non

- vascular IC 50 : > 34.2

NOAEC: > 34.2 1.02 < 0.0 3 <0.0 3

Almonds and Walnuts (1 ground application @ 0.26 lb a.i./A) Vascular N/A 0. 454 N/A N/A

Non

- vascular IC 50 : > 34.2

NOAEC: > 34.2 0.454 < 0.0 1 <0.0 1

Christmas Trees (1 ground application @ 0.26 lb a.i./A) Vascular N/A 0.964 N/A N/A

Non

- vascular IC 50 : > 34.2

NOAEC: > 34.2 0.964 < 0.03 <0.0350 B. Terrestrial Organisms

1. Terrestrial Wildlife

Table 24 provides acute and chronic risk quotients (RQs) for birds based on dietary toxicity studies, and Table 25 provide s additional acute RQs based on single

- dose oral toxicity studies. Since all uses of clofentezine are restricted to one application with a maximum application rate of 0.26 lb a.i./A, the RQs presented in these tables are applicable for all reg istered outdoor uses

of clofentezine ( i ndoor greenhouse uses are not expected to pose risk to nontarget wildlife)

. A s birds are used as surrogate species for assessing risk to reptiles and terrestrial

- phase amphibians, inferences based on these RQs are applied to those groups of organisms as well. T he very low acute toxicity of clofentezine resulted in all of the acute R Qs being very low. A ll acute RQs are well below EPA’s levels of concern (LOCs) for general risk to birds (0.5) and risk of adverse effects to threatened and endangered species of birds (0. 1). Thus, EPA concludes that all of the registered uses of clofentez ine pose minimal acute risk to birds, reptiles, and terrestrial

- phase amphibians.

Toxicity data show that sublethal effects caused by chronic exposure to clofentezine occur at much lower exposure levels than those which may cause mortality. Thus, c hronic RQs are higher than acute RQs, although they are somewhat limited by the relatively low maximum application rate and the restriction of use to one application per growing season. Dietary

- based chronic RQs are based on the observation of reduced embryo vi ability in the bobwhite quail at 90 mg ai/kg/diet, yielding a chronic NOAEL of 30 mg ai/kg

- diet (MRID 42776101). Chronic RQs exceed the EPA’s level of concern for chronic effects to birds (1.0) for birds that feed on shor t grass and broadleaf plants ( Table 24 ). Th is screening

- level assessment indicates that all registered outdoor uses of clofentezine pose a chronic risk to birds, reptiles, and terrestrial

phase s of a mphibians

, in c luding threatened and endangered species of birds, reptiles, and

terrestrial

- phases of amphibians.

Table 24

. Acute and Chronic D i e tary

- Based RQs for Birds

Application Rate (crop) Exposure Avian D ietary

- Based RQs

Short Grass Tall Grass Broadleaf

Plants Fruits

, Pods, &

Seeds Arthropods

One application @ 0.26 lb a.i./A (all uses) Acute <0.01 <0.01 <0.01 <0.01 <0.01

Chronic 2.08 0.95 1.17 0.13 0.8151 Table 25

. Acute Dose

- Based RQs for Birds

Application Rate (crop) Size Class (g) Avian Dose

- Based RQs

Short Grass Tall Grass Broadleaf

Plants Fruits &

Pods Seeds Arthropods

One application @ 0.26 lb a.i./A (all uses) 20 0.0 3 0.0 2 0.0 2 <0.01 <0.01 0.01

100 0.01 0.01 0.01 <0.01 <0.01 0.01

1000 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01

Table 26 provides acute and chronic risk quotients (RQs) for mammals based on dietary toxicity studies, and Table 27 provide s additional acute RQs based on single

- dose oral toxicity studies. The RQs presented in these tables are applicable for all registered outdoor uses of clofentezine. The very low acute toxicity of clofentezine resulted in all of the acute RQ s being very low. All acute RQs are well below EPA’s levels of concern (LOCs) for risk to mammals (0.5) and risk of adverse effects to threatened and endangered species of mammals (0.1). Thus, EPA concludes that all of the registered uses of clofentezine pose minimal acute risk to mammals.

C hronic RQs are based a chronic NOAE L of 20 mg a.i./kg

- BW day (MRID 00147844 ). C hronic dietary

- based RQ s for mammals do not exceed the EPA’s level of concern for chronic effects (1.0) for any dietary category ( Table 26 ). Most of the c hronic dose

- based RQs also are below

the chronic LOC for mammals , except for small to medium mammals that feed on short grass,

for which the chronic RQs slightly exceed one ( Table 27 ). The Agency therefore concludes that all registered outdoor uses of clofentezine potentially could pose a chronic risk to sm all

herbivorous mammal s , including threatened and endangered mammals , although this conclusion

is un certain

. Uncertainties of the potential chronic risk to mammals are discussed in Section

IV.B.

Table 26 . Acute and Chronic D i e tary

- Based RQs for Mammals

Application Rate (crop) Exposure Mammalian Dietary

- Based RQs

Short Grass Tall Grass Broadleaf

Plants Fruits

, Pods, &

Seeds Arthropods

One application @ 0.26 lb a.i./A (all uses) Acute <0.01 <0.01 <0.01 <0.01 <0.01

Chronic 0.16 0.07 0.09 0.01 0.0652 Table 27 . Acute and Chronic Dose

- Based RQs for Mammals

Application Rate (crop) Size Class (g) Mammalian Dose

- Based RQs

Short Grass Tall Grass Broadleaf

Plants Fruits &

Pods Seeds Arthropods

Acute
One application @ 0.26 lb a.i./A (all uses) 20 0.01 < 0.01 < 0.01 <0.01 <0.01 < 0.01

100 0.01 <0.01 <0.01 <0.01 <0.01 <0.01

1000 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01

Chronic
One application @ 0.26 lb a.i./A (all uses) 15 1.35 0.62 0.76 0.08 0.01 0.06

35 1.16 0.53 0.65 0.07 0.45 0.02

1000 0.62 0.28 0.35 0.04 0.24 0.01

2. Terrestrial Plants

In a vegetative vigor study, four dicotyledonous plants and two monocot y l edonous plants were

expos ed to Apollo 50 SC (49.8% a.i.) at a rate of 0.26 lb a

. i

. /A (MRID 47192103) . This limit test measured inhibition of plant wet weight and phytotoxic effects. Compared to the control, the plants exposed to 0.26 lb a.i./A did not show any significant reduction in biomass, as measured by plant wet weight, and did no t s how any signs of phytotoxicity. The application rate used in this study was equal to the maximum application rate for all registered crops. The EEC for nontarget terrestrial plants living outside the treatment site would be less than this application

rate. As the EEC has been demonstrated to be less than the IC 25 and NOAEL , the RQ s for both endangered terrestrial plants (EEC/NOAEL) and nonendangered terrestrial plants (EEC/IC 25 )

would be less than 1.0. The risk to emerged nontarget plants, including endangered species, is

thus less than the EPA’s level of concern

.

No data are available on the effects of clofentezine on the germination and emergence of nontarget plants. Therefore, risk from inhibition of the germination and emergence of seeds is

not known. However, considering that the vegetative vigor test found that clofentezine does not have any phytotoxicity activity at the maximum use rate , and clofentezine is recommended for use on a wide variety of woody and herbaceous plants in greenhouse use without any reported phytotoxicity

, the EPA assumes that use of clofentezine w ill not pose a ny risk significant risk to nontarget plants.

3. Bees and Other Nontarget Terrestrial Arthropods

Multiple lines of evidence indicate that use of clofentezine pose little risk to bees. An acute contact test with adult honey bees determined the L D 50 to be >1500 mg a

. i

. /L. Based on recommended dilution rates provided on the product labels, concentratio ns of clofentezine in tank mixtures would not be greater than approximately 600 mg a

. i

. /L. The 48

- hr mortality measured for bees exposed at a spray concentration of 1500 mg a

. i

. /L was 3.3%, which was less than the mortality observed in the vehicle control . Thus this study indicates that direct application of clofentezine product s to adult bees would cause little or no mortality. An acute53 oral toxicity honeybee study (MRID 00159121) found that the acute oral toxicity of clofentezine was >20 μg a.i. /bee. W hile the EPA does not have a bee toxicity classification scheme for acute oral exposure, if the scheme for acute contact toxicity for adult honey bees were applied

, clofentezine would be classif ied as practically nontoxic to bees. Yoshida and Fuchs (1989) found that acute contact of larval honey bees (5 th instar) caused elevated mortality with exposures of 50 μg a.i. /bee or greater, and caused increased occurrence of abnormal development at concentrations of 25 μg a.i. /bee and greater. The LOAEL of 25 μg a.i. /bee was associated with abnormal development of 42.3% of the pupa. By assuming all of the abnormal pupa would die, this LOAEL may be used as a conservative estimate of the LD 50 for exposed bee larvae. Again, if this conservative estimate of the LD 5 0 for bee larvae were compared to the

scheme based on the acute contact LD 50 for adult honey bees, clofentezine would be classified as practically nontoxic to bees

.

Yoshida and Fuchs (1989) derived an NOAEL for developmental toxicity resulting from topical exposure of clofentezine of 5 μg a.i./bee. By converting this NOAEL to a dose expressed as the amount per body weight, this NOAEL c a n be compared directly to the t errestrial EEC for arthropods to assess the potential for risk to bees. Assuming a honey bee weight of 0.128 g (USEPA, 2012)

, the NOAEL is equivalent to a dose of 39 mg a.i./kg

- bw. The maximum EEC for arthropods is 24.4 mg/kg ( Table 19 ). Therefore, this evaluation indicates that topical exposure of clofentezine to the honey bee will be below levels that would cause toxic effects. This conclusion is uncertain, howeve r, because the published study lacked replication, requiring effects levels to be estimated through visual inspection, and did not evaluate growth measurements such as size or weight.

In a pollen feeding study (Yoshida and Fuchs, 1989), instances of abnor mal development w ere observed when bee larvae were fed pollen with a clofentezine concentration of 1000 mg a.i./kg

pollen, but no instance of abnormal development was observed with exposure concentrations of 100 mg a.i./kg

- pollen or less. The same study f ound that the percentage of L1 and L2 larvae that sealed their cells appeared to decrease with clofentezine concentrations in pollen of 10 mg a.i./kg and greater. Compared to the control, the percentage of sealed cells decreased 6.9% and 9.1% when exposed to 10 and 100 mg a.i./kg. No decrease in sealed cells was evident in larvae exposed at the L3 through L5 stages with exposure concentrations up to 1000 mg a.i./kg. This is

consistent with the known mode of action of clofentezine to mites, the target art hropods, which is toxicity to eggs and early developmental stages. Unfortunately this study was conducted without replication, and thus the statistical significance of observed trends could not be

determined

.

To characteriz e potential risk to the honey bee, EFED compar ed the effect concentrations observed in the pollen feeding study of Yoshida and Fuchs (1989) with terrestrial EECs for plants treated directly with the maximum application rate ( Table 19 ) . The terrestrial EECs for plants range from 3.9 mg/kg (for fruits and pods) to 62.4 mg/kg (for short grass). Thus, plant EECs are below the NOAEL for observed abnormal development of bee larvae (100 mg/ kg), but were within the range in which a small percentage of observed adverse effects in bee larvae (<10% decrease of sealed cells). This suggests that if honey bees were to forage the flowers of plants directly treated with clofentezine soon after appli cation, and bring contaminated pollen back to the hive for feeding to larval bees, there is potential for risk to bees of the earliest54 development stage s

. While not evaluated in this study, exposure in the hive could possibly also cause toxicity to the eg gs of bees, as was observed in a study with the ladybird beetle ( Olszak 1999)

. However, as clofentezine may be applied only once per growing season, and residues on foliage are not expected to be highly persistent ( estimated half

- life is 15.7 days)

, the ov erall effect on reproduction of the hive is expected to be minor and transient.

Being an acaricide , some toxicity to nontarget arthropods is expected. S tudies with beneficial

insects have found clofentezine to have very little toxicity to adult in sects at environmentally

relevant concentrations . Studies indicating that clofentezine is practically nontoxic to adult bees have already been discussed ( see above). A nonguideline study submitted by the registrant (MRID 47192122) found no adverse effects to a ladybird beetle ( Coccinella septempunctata ) when they were exposed t o clofentezine spray at application rates of 0.089 and 0.18 lb a.i./A.

Samsoe

- Peterson (1993) observed no mortality in adult rove beetles ( Aleochara bilineata ) when sprayed with a solut ion of clofentezine at a concentration and spray rate equivalent to t he maximum application rate. However, s tudies have found that environmentally

- relevant

exposure s to clofentezine can cause adverse effects on survival and development of the early

life

- s tages of insects, including honey bees (Yoshida and Fuchs, 1989), coccinellid beetles (Olszak, 1999), and rove beetles (Samsoe

- Peterson, 1993). Because of this, these data indicate that use of clofentezine may pose a risk to non listed and threatened and endangered arthropods

that forage in treated orchards and tree farms. Overall, though, the toxicity and risk of clofentezine to nontarget arthropods appear to be less than that of most insecticides (Samsoe

Peterson, 1993; Olszak, 1999).

In conclusion, t oxicity data on the effects of clofentezine to adult and immature bees do not

warrant placement of any label statement to clofentezine products for the protection of bees. Use of clofentezine is not expected to harm adult nontarget arthropods which may be exposed in

treated sites during or after application. However, there is a potential for risk to nontarget arthropods from potential reproduction impairment and toxicity to early life

- stages. Direct adverse effects to threatened and endangered arthropods are therefore possible.



### VI. Risk Description and Characterization

The results of this screening

- level risk assessment indicate that the foliar uses of clofentezine have the potential for direct adverse effects to listed or non

- listed birds (and, thus, reptiles and

terrestrial

- phase amphibians), mammals, and terrestrial a rthropods . Therefore, the risk hypothesis from the Problem Formulation i s supported based on expected direct effects to these species . Because direct adverse effects to these taxa considered in this assessment are expected, indirect effects to listed spe cies are also expected through potential alterations to food source.

A. Risk to Aquatic Organisms

1. Aquatic Animals55 Aquatic exposure to clofentezine is limited by several factors: the relatively low application rate, the low mobility in water, the low solub ility in water, and the relatively rapid degradation of the parent by hydrolysis and photolysis. Clofentezine has also been found to not be toxic to fish and aquatic invertebrates at concentrations up to the solubility limit. This was sufficient to show t hat the acute RQ was less than the endangered species LOC of 0.05 for all uses except the use on fruit trees, for which the acute RQ was only shown to be less than 0.10. Aquatic TGAI toxicity

test s with fish and daphnids were conducted up to concentration s near saturation of clofentezine

. In the TEP studies, reliable measurements of dissolved active ingredient in the test solutions are

not available

, but since nominal test concentrations made with the suspended concentrate product

far exceeded the solubili ty limit of clofentezine, the dissolved concentration of clofentezine in

the se test solutions are also assumed to have been close to the solubility limit. Both the TGAI

and TEP studies found clofentezine caused no significant mortality (i.e., not greater than in the control) . Additionally, no sublethal effects were observed for either fish or daphnids at the highest test concentration

. Therefore, despite failing to show that the RQ for use on fruit trees is less than the LOC of 0.05 ( i.e.

, failing to demonstrate a 20x margin between the acute EEC and acute toxicity level ) , EPA believes that the lack of observed adverse effects at the solubility limit of clofentezine is enough evidence to conclude that all uses of clofentezine will not result in any adverse effects to fish or aquatic invertebrates, including endangered species. For chronic risk, all fish and aquatic invertebrate RQs were less than 1 for all uses, indicating chronic risk does

not excee d the EPA’s level of concern.

Clo fentezine is applied as products formulate d as suspension concentrates. Suspension concentrates are composed of small colloidal particles which remain suspended in the formulation and tank mixture when applied. When applied to plants, the solid particles are expected to move little from the use site, with primarily the residues that dissolve in water being transported to natural waters. However, spray drift may deposit onto bodies of water, thereby transporting the entire formulated product, including th e colloidal solid particles as well as the dissolved component of clofentezine. To evaluate the potential for risk from this route of exposure, the AgD RIFT model (v. 2.01) was used to estimate maximum initial water concentrations in a body of water receiv ing spray drift deposition . Since a 100

- ft buffer zone is required between application areas and natural water, the water body was assumed to be a 100 ft from the edge of the application area

. To be conservative, fine to very fine spray droplets were assumed, and a small water body was assumed with a width of 10 ft and a water depth of 0.5 ft.

The water concentration s estimated by this model were then compared to the toxicity endpoints obtained from the aquatic to xicity tests with the TEP.

Using the maximum product application rate of 8 oz /A (0.5 lb a.i. /A) , AgDRIFT predicts an

initial water concentration of 8.70 μg product /L if the application was made with a ground boom,

or 0. 218 μg product /L if it is done an air blast application is made

. TEP testing with Apollo 50 SC found that product concentrations up to 24 mg/L did not cause mortality to fish (MRID 40912101), and product concentrations up to 100 mg/L did not cause immobility in daphnids

above the level ob served in the control (MRID 40568202). These test concentrations are over 3 orders of magnitude greater than the predicted initial product concentrations in the water body receiving spray drift. Therefore, spray drift of the product clearly will not yiel d water
concentrations that w ould approach toxic levels , and thus would not result in any adverse acute

effects to fish or aquatic invertebrates.56 Chronic tests with a formulated product of clofentezine found toxic effects to the reproduction of aquatic or ganisms, but only at concentrations above those predicted to occur from registered use s of clofentezine. A fish early life stage study with Apollo 50 SC did not find observable sublethal

effects at a concentration of 979 μg/L, which is much higher than the predicted chronic EECs. All chronic RQs for fish were less than 0.01. Clofentezine showed greater toxicity to aquatic

invertebrates in life

- cycle studies. The most sensitive endpoint in these studies was fecundity (th e number offspring produced per female). Reproductive effects were observed at concentrations as low as 44 μg/L in the waterflea (a saltwater crustacean) and as low as 3.6 μg/L in the mysid (a saltwater crustacean).

The mode of action of clofentezine t o the target species, mites, is toxicity to eggs and early life stages. It thus appears that clofentezine may exhibit the same mode of action in aquatic arthropods as well. However, a Daphnia magna reproductive toxicity study of Barber and Barrett (1983) suggests an alternative explanation of chronic toxicity to aquatic invertebrates. This study measured the reproductive response of Daphnia magna when exposed to three concentrations of Apollo 50 SC (50% clofentezine) and three concentrations of inert pol yvinyl toluene (PVT) latex beads. Apollo 50 SC is a suspension concentrate formulation, meaning that it consists of small particles of solid clofentezine that remain suspended in the product and applied tank mixture. The test concentrations of latex beads had equivalent particle concentrations as did the Apollo 50 SC. The result of the study showed reproduction performance was significantly reduced when exposed to both the Apollo 50 SC and the PVT

bead treatments. The percent reduction in number of offsp ring produced per female was similar

, regardless if the test was conducted with the clofentezine product or with the latex beads. The study authors th us concluded that the effect of Apollo 50 SC was not due to any intrinsic toxicity of the formulation, bu t rather a consequence of its particular concentration. They suggest that the ingestion of both the clofentezine particles and the latex beads by the waterflea while filter feeding reduced the organism’s feeding efficiency, which resulted in the organisms having reduced reproductive output.

Regardless of the cause of the chronic toxicity, the lowest NOAEC obtained in the aquatic reproductive test (1.7 μg a.i./L for the mysid) was higher than the highest chronic EEC for aquatic invertebrates (0.49 μg a.i ./L for use on fruit trees). The highest chronic RQ was

therefore less than the EPA’s chronic LOC ( 1 )

.

Some uncertainty exists for chronic risk to freshwater invertebrates because one study with the

waterflea ( Daphnia magna ) failed to identify an NOAEC, finding significant reduction in fecundity at the lowest test concentration of 44 μg a.i./L (MRID 47192117) . This test level is approximately 10 0 times greater than the maximum chronic EEC (0.49 μg a.i./L). The percent reduction in number of offsprings p er female observed at 44 μg a.i./L was relatively small, 8.25%, and thus

, even less reduction on offspring production is expected at the maximum

chronic EEC (0.49 μg a.i./L) . Furthermore, two other chronic studies with Daphnia magna which did obtain NOAECs found no significant chronic effects at test concentrations well above the chronic EEC. A study submitted by the registrant (MRID 42523901) obtained an NOAEC of 26.2 μg a.i./L, and a published literature study Barber and Barrett ( 1993) obtained an NOA E C of 60 μg a.i./L. T hese NOAECs are near to or above the solubility limit of clofentezine and well57 above even the highest predicted peak EEC (4.34 μg a.i./L)

. Finally, the comparison of results of

MRID 47192117 with the mysid life

- c ycle study (MRID 48342701) indicates that th e mysid is the more sensitive species of the two. While a test concentration of 44 μg a.i./L resulted in only

an 8.25% reduction in fecundity in the waterflea study, a lower test concentration of 29 μg a.i./L

re sulted in a 23.7 % reduction in fecundity in the mysid study

. Since a lower concentration resulted in greater impairment of reproduction, the mysid appears to be more sensitive than the

waterflea. Thus, the risk conclusions of low chronic risk based on t he mysid study should be protective freshwater invertebrates as well.

In conclusion, the lack of a fully acceptable study with a freshwater invertebrate and the nondefinitive results obtained in two of the supplemental studies increases uncertainty in t he risk assessment for freshwater invertebrates, the weight of the evidence indicate that chronic exposure levels will likely remain below levels that could otherwise pose chronic effects such as reproduction impairment.

2. Aquatic Plants

Risk of clofentez ine to aquatic plant is uncertain because toxicity data are available for only one species, green algae

. An algal toxicity test with the TEP (MRID 47200501) found no observable adverse effects to green algae at nominal concentrations up to 100 mg product/ L. This

concentration i s far greater than would be expected to occur in natural water from deposition of spray drift. Thus, contamination from spray drift of the formulated product would not pose a significant risk to green algae. While this study faile d to measure the concentrations of dissolved test material (since the samples were not filtered prior to analysis), the amount of suspended

clofentezine added to the test solutions far exceeded the solubility of clofentezine, and thus the

concentration of clofentezine in the test solutions would likely be close to the solubility limit

. Thus , the study demonstrated that clofentezine does not adversely affect the growth of green algae up to the aqueous solubility limit of 34.2 μg a.i./L. The highest predict ed peak EEC was 3.34 μg a.i./L for fruit trees. Thus, there is at least a 10

- fold margin of safety between the expected peak exposure levels and the threshold of toxic effects for green algae. As clofentezine is applied only once per year and residues in water degrade fairly rapidly by hydrolysis , water concentrations are expected to decline fairly rapidly from the peak, creating an even greater margin of safety

. While some uncertainty exists in the risk assessment because of the lack of testing of specie s other types of green algae and diatoms , the EPA believes that the available

information is sufficient to conclude that use of clofentezine will not cause significant adverse effects to nonvascular aquatic plants

.

Lack of data on the toxicity of clofente zine to vascular aquatic plants , and classes of nonvascular aquatic plants other than green algae, prevents quantitative assessment of risk to vascular aquatic plants. However, since clofentezine does not have a known mechanism of action that is relevant to toxicity to plants, exhibited low phytotoxicity in a study of terrestrial vascular plants, has no reported incidents or issues concerning plant safety, there is no reason to suspect that clofentezine would be toxic to these other classes of aquatic plan ts. Considering the low solubility of clofentezine, and the low predicted concentrations in natural waters, registered use s of clofentezine is not expected to pose significant risk to any aquatic plants , and will not likely harm threatened or endangered s pecies of aquatic plants

.58 B. Risk to Terrestrial Organisms

1. Nontarget Terrestrial Vertebrates

Acute toxicity studies with both birds and mammals indicate that clofentezine has low toxicity to

terrestrial vertebrates. In addition, the relatively low use rate of clofentezine (0.26 lb a

. i

. /A)

limits exposure to terrestrial animals. These two factors combine to create very low acute RQs for terrestrial vertebrates, with RQ values below 0.01 for all uses. Additionally , no incidents have been reported that attrib ute wildlife mortality to exposure to clofentezine.

However, chronic exposure to c lofentezine is more toxic to terrestrial vertebrates. For birds, adverse effects on reproduction were observed at dietary concentrations as low as 90 mg ai /kg

diet, with a NOAEL established at 30 mg ai/L. Maximum EECs of clofentezine on foliage (short grass and broadleaf plants) , assuming exposure immediately after application

, are predicted to

exceed the chronic NOAE C , making the RQs greater than the chron ic LOC of 1. Clofentezine appears to have somewhat less chronic toxicity to mammals. For mammals, dietary

- based

chronic RQ s d o not exceed the chronic LOC for mammals of any dietary class . When calculated

based on the expected daily dose of active ingredi ent per unit body weight, however, chronic RQs for mammals slightly exceeded 1 f or mammals of small (15 g) and moderate (35) weight

classes that feed on short grass

. Together these results indicate potential chronic risk to birds, and potential but uncerta in chronic risk to some small mammals.

While the screening

- level risk assessment indicates potential chronic risk to terrestrial vertebrates, several factors would limit the extent of this risk. First, the terrestrial maximum

EECs fall close to the threshold for conclu ding potential chronic risk. While a few EECs exceed the NOAEC, none of the EEC s exceed the LOAEC. Maximum dietary

- based EECs that do exceed the NOAEC do so by no more than about a factor of 2. Second, clofentezine is not very persis tent in the terrestrial environment. The photolysis half

- life is less than 7 days, and thus residues on foliage and fruit exposed to the sun are expected to dissipate fairly quickly. This would mean that the length of exposure to chronically toxic residu es through consumption of contaminated plants would be fairly short. Finally, only one application of clofentezine is permitted per growing season. This limit reduces the amount and duration of exposure, compared to pesticides with multiple application s

.

In the screening

- level risk assessment, RQs are calculated based on the peak EEC ( i.e. , those immediately after application before any degradation takes place. This would represent the exposure of an animal feeding in a treated orchard immediately after treatment. The persistence of the residues on the food items being consumed would influence the risk of reproductive and developmental effects occurring in that animal. If the residues quickly drop below potentially

toxic level s , then the exposure to th e animal in the field would not necessarily result in the same reproductive or developmental impairment that was observed in chronic laboratory stu dies, where the animal is exposed to a set dietary concentration for a long duration, such as 21 weeks

in the avian reproduction study. While it is possible that the shorter

- term exposure would produce the same reproductive effects as the long

- term exposure, this is less certain than for a more persistent chemical, for which the duration of exposure in the wild would more closely match the duration of exposure in the avian reproduction tests.59 To evaluate the duration that residues on wildlife food items would remain above potentially toxic levels, a half

- life for residue decline on those items must be estimated. The dietary

- based

risk assessment indicates that birds feeding on plant foliage (short grass or broadleaf plants) may be at risk. Unfortunately data were not available to measure a half

- life for foliar residues. Instead, we used a study which measured the decline of residues on grapes after treatment with

clofentezine (MRID 45080701) . A review of this study by the Health Effects Division found it to be scientifically acceptable. While the absolute concentration of residues on grapes may be quite diffe rent than on leaves, the decline of residues is expected to be similar. Thus the half

- li fe of residues in this study is expected to be a reasonable estimate of the foliar half

- life.

Table 28 gives residue concentrations measured on grapes between 0 and 21 days after a single application of Apollo at the application rate of 4.0 oz product /A ( 0.125 lb a.i./A). From these values, a first

- order decline rate (k) was estima ted to be 0.0441, and the half

- life (T 1/2 ) was

estimated to be 15. 7 days. This indicates that clofentezine residues are moderately persistent on foliage. Assuming the same rate of decline for residues on foliage, the foliar EECs are expected

to decli ne over time as depicted in Figure 5 . For reference, the avian NOAEC value is also depicted as a horizontal line

. R esidues on short grass are expected to remain abo ve the avian

chronic NOAEC for approximately 16

- 17 days after application , whereas r esidues on broadleaf plants are expected to remain above the avian chronic NOAEC for approximately 5 days. Residues on tall grass and arthropods (not shown) are not expect ed to exceed the NOAEC at any
time. In the laboratory which determined th e NOAEL , birds were exposed to clofentezine for 10 to 20 weeks while laying eggs. Thus, their duration of exposure was much longer durations of exposure expected for wild birds feed ing in treated orchards. While it is possible that the same

effects could occur after the much shorter exposure period expected in the field (i.e., the 16 to 17 days when the EEC is expected to exceed the NOAEC), it is also possible that these shorter

expo sure durations would not cause the same reproductive effect s

. .

Table 28 . Measured Concentration of Clofentezine After an Application of Apollo at 4 oz/acre (from MRID 45080701)

Days Post

- Application Concentration of Clofentezin e on Grapes (ppm)

0 0.79

1 0.41

3 0.75

7 0.45

14 0.34

21 0.2960 Figure 5 . Expected decline of maximum clofentizine residues on foliage, in relation to the avian

NOAEC value.

Also, the screening level risk assessment used upper bound values predicted by the T

- R EX

model to represent the maximum residue concentrations expected on wildlife food items . These values represent the highest concentrations expected to be found on a treated field immediately after application (Fletcher et al., 1994). While it is possible that a particular animal may feed in the area of the field with the maximum residues, the concentration that would be encountered by a typical bird would be better represented by the values T

- R EX predicts for mean residue

concentrations ( Table 29 )

. These values represent the mean of all concentrations expected in various places on a treated field immediately after application. As evident from Table 29 , n one of the mean concentrations exceed the NOAEC for birds (30 mg/kg). Of course, these residues

woul d decline further as time after application increases. Thus, an animal feeding in an area of the treated field with average residue concentrations is not expected to have any adverse effects to reproduction or development via dietary exposures

.

Table 29

. Dietary

- Based Clofentezine EEC Values Based on Predicted Mean Concentrations Dietary Item Dietary

- Based EEC (mg/kg)

Short Grass 22.10

Tall Grass 9.36

Broadleaf Plants 11.70
Fruits, Pods, and Seeds 1.82 Arthropods 16.90

For mammals, the chronic risk conclusion is more uncertain than for birds. Even the peak EEC for immediately after application (62.4 mg a.i./kg) is below the mammalian chronic NOAE L for reproductive effects (400 mg ai/kg), thus making the dietary RQ below the LOC of 1 (RQ = 0.16). It is only when the NOAEL is converted to a daily dose (assuming 100 mg/kg

- die t is equivalent to 5 mg a.i./kg

- bw) and compared to the expected daily doses that the LOC exceeded, 0.00 10.00 20.00 30.00 40.00 50.00 60.00 70.00

0 5 10 15 20 25 30Predicted Concentration (ppm)

Days Short Grass

Broadleaf Plants

Tall Grass

Avian NOAEC61 and then only slightly and only for small to medium mammals consuming short grass (RQ 1.35

for 35

- g mammal and 1.16 for 35

- g mammal). The disagreement of these two risk assessment approaches add uncertainty to the risk conclusion for mammals. Furthermore, since no frank effects were observed at any test lev el in the 2

- generation rat reproduction study, it is possible that the actual NOAEL is somewhat higher than the one used to calculate the RQs. Therefore, it is possible the chronic RQs for mammals might be less than the LOC if the actual NOAEL was

known.

.

In conclusion, the screening level risk assessment indicate that exposure to clofentezine may cause adverse reproductive and developmental effects to wildlife that feed on the treated field during a time when it is reproducing. However, th is risk appears to be limited for the following

reasons:

• Maximum EECs fell between the avian NOAEC and LOAEC, and thus the studies did

not confirm that adverse effects would occur at the EEC.

• Dose

- based EECs for mammals are only slightly above the highest dose tested in the chronic mammal toxicity study. It is possible that the EEC would not be above the NOAEL if higher doses were tested.

• Dietary

- based risk assessment predicted risk only for a nimals which feed on short grass or broadleaf plants, but not other food items

• While maximum expected dietary concentrations exceed the NOAEC for birds, mean

residue concentrations do not.

• For mammals, chronic risk is predicted by dose

- based RQs only for s hort grass, but not by any dietary

- based RQs.

2. Terrestrial Arthropods

As with any acaricide or insecticide, clofentezine will pose some risk to nontarget terrestrial arthropods. However, the risks posed by clofentezine appear to be quite limited compared to
other acaricide or insecticide. The toxicity of clofentezine is specific to eggs and early larval stages, with very little toxicity to adult arthropods. Therefore, use of clofentezine is not expected

to pose a risk to adult insects who feed on treated orchards, including worker bees and other insect pollinators such as butterflies and moths. Studies have shown that exposure to clofentezine at environmentally relevant exposure levels does reduce fecundity and reduces survival of early life stages of be etles (Olszak, 1999; Samsoe

- Peterson, 1993) and the honey bee ( Yoshida and Fuchs, 1989). Yoshida and Fuchs (1989) found that clofentezine has less reproductive toxicity to bees than to Verroa mite, indicating that the toxicity is somewhat

selective to mit es.

Clofentezine may be applied only once per year, and clofentezine is not highly persistent in the

environment

. Therefore, any adverse effects that may result to the reproduction of nontarget arthropods are expected to be transient and not have significant population

- or ecosystem

- level

effects. However, some impairment of the reproduction of nontarget insects and arachnids is62 possible. Since the toxici ty of clofentezine is specific to eggs and early life stages, listed species

of terrestrial arthropods may be adversely affected

, includ ing those which would lay their eggs on trees or other vegetative plants in treated orchards and vineyards, and pollinat ors which would collects nectar or pollen from flowers of treated plants during periods of reproduction.

3. Terrestrial Plants

A tier 1 vegetative vigor study found that exposure of four dicotyledonous plants and two monocotyledonous plants to Apollo 50 SC a t a maximum application rate of 0.26 lb a

. i

. /A caused no observable adverse effects (MRID 47192103). Exposure by spray drift to nontarget terrestrial plants living outside the treatment site would be equal to or less than this application rate.

Therefore , spray drift from all uses of clofentezine are not expected to adversely affect the vegetative vigor of nontarget plants. The fact that no incidents of phytotoxicity damage ha ve been reported for clofentezine is consistent with the conclusion that foliar exposure to
clofentezine is not expected to be harmful to plants.

No data are available on the effects of clofentezine on the germination and emergence of nontarget plants. Therefore, risk from inhibition of the germination and emergence of seeds is

not known. However, the following lines of evidence suggest that clofentezine is not phytotoxic to plants:

• The mode of action of clofentezine is not relevant to toxicity of plants

.

• A vegetative vigor study found no observable phytotoxicity at the maximum ap plication

rate

.

• C lofentezine is recommended for use on a wide variety of woody and herbaceous plants in greenhouse use without any reported phytotoxicity.

Furthermore, clofentezine is applied only by ground equipment and has low mobility in soil,

factors t hat limit exposure to nontarget plants via spray drift and runoff, respectively. Therefore

, the EPA assumes that use of clofentezine is not expected to pose any risk to nontarget plants

, including listed species of terrestrial plants

.

C. Ecological Incidents

A preliminary review of the Ecological Incident Information System (EIIS, version 2.1) in May 2012 did not identify any ecological incident of adverse field effects to nontarget plants or

animals which was attributed to use of clofentezine . Also, review of the Avian Monitoring Information System (AIMS), which is maintained by the American Bird Conservancy, did not identify any ecological incident associated with the use of clofentezine

.

In addition to the incidents recorded in EIIS and AIMS, the Agency maintains a database which stores counts of minor incidents that pesticide registrants record in quarterly aggregated incident reports. Ecological incidents recorded in these aggregated re ports include those categorized as ‘minor fish and wildlife’ (W

- B), ‘minor plant’ (P

- B), and ‘other non

- target’ (ONT) incidents, which includes reports of adverse effects to bees and other invertebrates. A review of this63 database in February 201 4 did not identify any minor incident associated with use of

clofentezine.

D. Uncertainties , Limitations, and Assumptions

1. Endocrine Disruption

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

sus ceptible to endocrine influence, including effects on endocrine target organ histopathology, organ weights, estrus cyclicity, sexual maturation, fertility, pregnancy rates, reproductive loss, and sex ratios in offspring. For ecological hazard assessments, EPA evaluates acute tests and chronic studies that assess growth, developmental and reproductive effects in different taxonomic groups. As part of the Preliminary Problem Formulation for Registration Review (DP Barcode D336262)

, EPA reviewed these data a nd selected the most sensitive endpoints for relevant risk assessment scenarios from the existing hazard database. However, as required by FFDCA section 408(p), clofentezine is subject to the endocrine screening part of the Endocrine Disruptor Screening P rogram (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 occurring estrogen, or other such endocrine effects as the Administrator may designate.” The EDSP employs a two

- tiered approach to making the statutorily required determinations. Tier 1 consists of a battery of 11 screening assays to identify the potential of a

chemical substance to inter act 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

wil l determine which, if any, of the Tier 2 tests are necessary based on the available data. Tier 2 testing is designed to identify any adverse endocrine

- related effects caused by the substance, and

establish a dose

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

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

- ins for the first group of 67 chemicals, which contains 58 pesticide active ingre dients and 9 inert ingredients. Clofentezine is not among the group of 58 pesticide active ingredients on the initial list to be screened under the EDSP. Accordingly, as part of registration review, EPA will issue future EDSP orders/data call

ins, requir ing the submission of EDSP screening assays for clofentezine

. For further information on the status of the EDSP, the policies and procedures, the list of 67 chemicals, future lists, the test guidelines and the Tier 1 screening battery, please visit our we bsite: http://www.epa.gov/endo/

.64 2. Uncertainties Related to Data Limitations

In the absence of available data to describe the adsorption

- desorption of clofentezine in the soil,

EPI Suite was used to estimate the K oc of 516.1 L/kg

. Although there are uncertainties associated with the estimated Koc, it predicts moderate mobility in soil and aquatic

environments.

Numerous limitations in the available toxicity data set contributed to uncertainty in this risk

assessme nt. Chronic toxicity studies with fish were limited to early life

- stage studies . These

studies measured toxic effects of clofentezine to eggs and larval stages, but did not evaluate potential impacts on the fecundity of adult female fish exposed to the c ompound. For aquatic invertebrates, several life

- cycle studies were available

, but they all suffered deficiencies that

caused them to be classified as supplemental. In addition, two of the studies failed to test at levels low enough to establish a NOAEC. Because they failed to establish the chronic NOAEC, the lowest LOAEC value (44 μg/L from MRID 47192117) was used to assess risk to freshwater invertebrates. The study of chronic effects to the saltwater invertebrates (MRID 48342701) did produce a NOAEC, but the results were uncertain because the diluter system in the study failed to deliver consistent concentrations of test solution in the exposure chambers . Finally, toxicity data were not available for some aquatic species, including estuarine mollusks ( e.g. , the oyster),

sediment

- dwelling arthropods, aquatic vascular plants, diatoms, and blue

- green algae. These species may be more sensitive than the species which were tested , and thus the risk assessment may have underestimated risk to aquatic inverte brates and plants.

(Barber and Barrett, 1993) provides data suggest ing that reproductive impairment observed in

chronic studies with daphnids exposed to Apollo SC, a suspension concentrate formulation of clofentezine, may be the result of physical stress caused by ingesti on of small solid particles

while filter

- feeding, rather than by inherent toxicity of clofentezine. The ch r onic endpoint used

in th e freshwater invertebrate risk assessment was based on a life

- cycle toxicity study conducted

with Apollo 50 SC (MRID 47192102) , and thus the observed toxicity may have been caused by exposure to suspended particles . Crustaceans living in the wild exposed to clofentezine from runoff from treated areas would be exposed mainly to dissolved clofentezine, without the high concentration of suspended particles present in the laboratory study. Thus, t he study may have

ove restimated chronic risk to freshwater invertebrates in the wild

.

The lack of complete phyto toxicity data for clofentezine also creates uncertain ty in the risk

assessment for terrestrial plants. Only one vegetative vigor study has been submitted (MRID

471 92103). That study was classified as supplemental because it tested only 6 plant species, whereas the guideline requires 10 species. No seedling emergence data have been submitted, therefore it was not possible to assess the risk of impairment of the ger mination or emergence of plants. Nevertheless, the risk assessment concluded that significant adverse effects to nontarget plants from use of clofentezine are unlikely (see Section VI.B.3.)

The lack of toxicity data on the two major degradation products that are expected to fo r m in the environment also contributes to uncertainty in this risk assessment. Risk could be underestimated if either of these degradates are significantly more toxic to nontarget organisms than the parent compound. QSAR analysis using the ECOSAR program do es not predict65 significant toxicity for these degradates with the possible exception of toxicity of A E C593600 to aquatic plants (Section II.E.3). ECOSAR results provided contradictory predictions for the toxicity of A E C593600 to green algae based on comparisons with different chemical classes (Table 12) , and further evaluation led to the conclusion that this compound is not likely to be very toxic to aquatic plants

. However, risk could have been underestimated if A E C593600 i s actually very toxic to aquatic plants (as suggested by one of the ECOSAR predictions) , or if either of the major degradate compounds is more toxic to any taxa of organisms than the QSAR analysis predicted.

3. Uncertainty in Risk Conclusions

The conclusion of “no effects” for threatened and endangered fish is not highly certain because the nondefinitive endpoint obtained for acute toxicity to fish was not sufficient to demonstrate that RQ is less than the LOC for endangered species (0.05) for use on fruit trees. Measurement

of t he acute LC 50 for fish was limited by the solubility of clofentezine and thus only was shown to be greater than 34.2 μg/L . The LC 50 would need to be greater than 66.8 μg /L for the acute RQ

to be less than the 0.05 . A conclusion of “no effects” was made based on the lack of toxic effects observed at the solubility limit of 34.2 μg/L, which is approximately 10 times greater than the peak EEC. Nevertheless, this conclusion would have been more certain if all of the acute RQs

for fish were found to be less than the LOC of 0.05.

Finally, the conclusion that use of clofentezine will pose chronic risk to terrestrial wildlife is uncertain because chronic RQ s were only slightly greater than the LOC when considering the peak EEC

, but would not exceed the LOC when considering the mean EEC . In some cases peak terrestrial EECs on wildlife food items exceeded the NOAEC for chronic effects, but in no case did they exceed the LOAEC. Chronic RQs were calc ulated based on the maximum EEC predicted by the T

- R EX model. If RQs were calculated based on mean EECs, which predict average residues expected throughout a treated field, the RQs would not exceed the LOC. Also, as clofentezine may be applied only once per season, and terrestrial residues are expected to dissipate fairly rapidly, even the maximum EECs would be expected to remain at potentially toxic level for no more than 17 days for residues on short grass, or 4 days for residues on broadleaf plants (Fi g. 5). In the chronic toxicity studies, test animals were exposed to clofentezine for much longer durations than this (for example, approximately 22 weeks in the avian reproduction study). Thus, it is uncertain that the relatively short exposure that is expected to animals in the wild would produce as much chronic toxicity as observed in the laboratory

studies.

The risk assessment determined that risk exceeds the EPA’s LOC only for chronic effects to

terrestrial animals

. Because clofentezine may only be applied one time per year, the chronic terrestrial RQs cannot be reduced by limiting the number of allowable applications or increasing the minimal application interval. Only reducing the single application rate would reduce these chronic RQs. For protec ting birds, the maximum single application rate would need to be reduced to <0.125 lb a.i./A to reduce the chronic RQ to less than the chronic LOC (1). For protecting mammals, the single application rate would need to be reduced to < 0.19 lb a.i./A, to

red uce the RQ to less than the LOC.66 

### VII. Risk Conclusions

The results of this screening

- level risk assessment indicate that all outdoor uses of clofentezine have the potential for direct adverse effects to listed and non

- listed birds and mammals. As birds

serve as surrogates to reptiles and terrestrial

- phase amphibians , risk to these taxa is also possible

. Risk to terrestrial vertebrates is associated with sublethal effects on reproduction and growth that may occur with chronic exposure. However, the risk of c hronic effects to mammals is uncertain because dietary

- based RQs do not exceed the LOC

. Use of clofentezine is not expected to pose a risk to foraging bees, but because of potential adverse effects to reproduction and development

, potentially may harm nonlisted and listed species of terrestrial arthropods. Use of clofentezine is not expected to cause direct or indirect adverse effects to fish

, aquatic invertebrates, terrestrial plants , or aquatic plants

.

Based on the available data, suspended concentr ate (SC) formulated products of clofentezine are slightly to practically non

- toxic to freshwater fish and invertebrates on an acute

- exposure basis. The limited solubility of the technical grade active ingredient (TGAI) prevented classification of

the acut e toxicity, but the TGAI was shown to be nontoxic at concentrations that are close to the limit of its solubility in water. Acute RQs for fish and aquatic invertebrates were below the EPA’s LOC for listed and nonlisted species. Chronic toxicity tests did not find any adverse effects caused by chronic exposure to fish at concentrations up to the solubility limit. C hronic exposure to aquatic invertebrates was found to inhibit reproduction ; h owever, the NOAEC in these studies were greater than expected envi ronmental concentrations (EECs) , and thus the

c hronic RQ s are all below EPA’s LOC.

For terrestrial birds and mammals, clofentezine is practically nontoxic on an acute exposure basis. The lack of toxicity and the relatively low use rate resulted in acute risk quotients well below the EPA’s level of concern. However, chronic studies identified adverse sublethal effects

to birds and mammals. Because the NOAEL of these studies were less than the EEC for some types of birds and mammals, the chronic RQs were above the EPA’s LOC (dieta ry

- based RQs

0.08

– 2.08, dose

- based chronic RQs 0.0 1

– 1.35 ) . Thus, all uses of clofentezine are predicted to pose chronic risk to birds, mammals, reptiles, and terrestrial amphibians, and may cause adverse effects listed specie s of these taxa. The chronic risk to terrestrial animals is un certain because the two chronic risk assessment approaches gave different conclusions. Since the peak dietary

EEC s for all dietary items were less than the exposure level which caused no frank effects in a mammal 2

- generation rat study ( MRID 00147844 ) , the dietary

- based risk assessment approach concludes that the chronic risk is below the level of concern. However, when the daily oral dose is converted to an approximate dietary concentration ( based on the assumption of the dietary

concentration for an adult rat ( mg/kg

- diet ) is approximately equivalent to 20 times the d aily dose expressed as mg/kg

- BW per day ) , the chronic RQ slightly exceeds the chronic LOC for small to

medium mammals that feed on short grass (RQs 1.16 to 1.35). Another source of uncertainty is

that the two

- generation rat reproduction study did not test to high enough levels to generate frank effects on growth, survival, or reproduction. Therefore, the NOAE L was set at the highest test

dose of 20 mg ai/kg

- BW day (assumed to be equivalent to 400 kg a.i./kg

- diet ). If the pesticide would have been tested at higher levels, i t is possible that somewhat higher exposure levels might also fail to produce frank effec ts, yielding a higher NOAEC. If the actual NOAEC is 540 mg ai.i/kg

- diet or greater, then none of the chronic RQs would not exceed the LOC.67 A honey bee contact study found that clofentezine is practically nontoxic to adult bees. Based on

available acute toxicity data , no specific bee acute hazard statement is currently needed on product labels. Studies with beneficial beetles have found that clofentezine also has low acute toxicity to these species. However, as with mites (the target species), clofente zine has been

found to cause toxicity to eggs and early life

- stages of bees and other insects . While the available toxicity data and risk assessment methods do not allow for a precise description of th e chronic risk to terrestrial insects

, a qualitative e valuation indicates that potential risk of clofentezine use to cause significant brood effects in bees is small. However, because of potential reproductive effects, the EPA believes that all uses of clofentezine have the potential to

cause adverse effects to nonlisted and listed species of terrestrial arthropods.

Because clofentezine is applied only once per year and residues are not very persistent in the environment, chronic effects to terrestrial animals are not expected to be on a scale that would

si gnificantly affect their populations. Therefore indirect effect s to endangered organisms from loss of ecological services, such as diminished seed dispersal of plants, are believed to be

discountable.

Several lines of evidence indicate that clofentezine h as low toxicity to plants. Toxicity to plants is not expected by the mode of action of this pesticide (toxicity to eggs and growth inhibition of early life

- stages of invertebrates). Limit tests conducted with terrestrial plants found no significant phyto toxicity when plants were treated directly at the maximum application rate. A limit study testing the toxicity of a formulated product of clofentezine to green algae also found no observable toxic effects when tested at the high concentration of 100 mg pr oduct/L. Although other types of aquatic plants may be more sensitive, and testing with other species of aquatic plants would be needed to draw general conclusions for aquatic plants as a group, this test indicates that clofentezine is not toxic to green a lgae at the solubility limit of clofentezine. Also,

clofentezine is routinely applied to a wide variety of plants in greenhouses , orchards, and tree farms without any reported problems with phytotoxicity or plant damage incidents . Therefore,

EPA concludes that use of clofentezine will not pose significant risk to either terrestrial or aquatic plants, and is not expected to harm listed species of plants.

Conclusions on the potential for clofentezine to cause direct and indirect effects to federally

listed threatened and endangered species of various taxa are summarized in Table 30

. Conclusions for direct effects to listed species are also summarized in Table 1 of the Executive Summary.

Table 30

. Non

- listed and Listed Species Risks Associated with Potential Direct or Indirect Effects Due to the Application s of Clofentezine

LISTED TAXON DIRECT EFFECTS INDIRECT

EFFECTS 1 Non

- listed Listed

Terrestrial and semi

- aquatic plants

– monocots No No No

Terrestrial and semi

- aquatic plants

– dicots No No No68 LISTED TAXON DIRECT EFFECTS INDIRECT

EFFECTS 1 Non

- listed Listed

Birds Yes Yes Yes

Terrestrial phase amphibians Yes Yes Yes

Reptiles Yes Yes Yes

Mammals Yes Yes Yes

Terrestrial Invertebrates Yes Yes Yes

Aquatic plants No No No

Freshwater fish No No No

Aquatic phase amphibians No No No

Freshwater crustaceans No No No

Mollusks 2 No No No

Marine/estuarine fish 2 No No No

Marine/estuarine crustaceans 2 No No No

1 Indirect effects may include general habitat modification, host plant loss, and food supply disruption.

2 Quantitative data are not available for saltwater invertebrates, therefore RQs were not calculated. Risk conclusions were based on risk quotients calculated for freshwater invertebrates.69 

### VIII. References

Barber, I. and K. Barrett. 1993. The effect of a pesticide suspension concentrate formulation on Daphnia magna Straus reproduction. Sci. Total Environ

., 134 ( Suppl. 2): 853

- 858

.

BEAD, 2012. Usage/Use Report Package in Support of Registration Review for Clofentezine

. Memorandum from Biological and Economic Analysis Branch to Pesticide Re

Evaluation Division. March 01, 2012.

Clements, R.G., J.V. Nabholz, and M. Zeeman. 1996. Estimating toxicity of industrial chemicals to aquatic organisms using structure

- a ctivity relationships

. Ed.: R.G. Clements.

IRAC. 201 2

. IRAC MoA Classification Scheme . Version 7. 2 . IRAC International MoA Working Group. 23 pp. Available online at: http://w ww.irac

- online.org/content/uploads/MoA

- classification.pdf

JMPR, 2007. Pesticide Residues in Food 2007, Evaluations Part 1

– Residues . Joint Meeting of

the FOA Pa nel of Experts on Pesticide Residues in Food and the Environment and the

WHO Core Assessment Gr oup, Geneva, Switzerland, 18

- 27 2007. FAO Plant Production and Protection Paper 19 2

. World Health Organization and Food and Agriculture Organization of the United Nations. Rome, 2008. Available online at: http://www.fao.org/ag/AGP/AGPP/Pesticid/JMPR/Downlo ad/2007_eva/Evaluation.pdf

Lentz, Nancy R. 2010 a . [14C] Clofentezine

– Aerobic Aquatic Sediment Metabolism, Springborn Smithers Laboratories, Wareham, Massachusetts, Sponsored by Irvita Plant

Protection N.V. c/o Makhteshim

– Agan of North America Inc. 4515 Falls of Neuse Rd., Suite 300, Raleigh, NC, USA, 27609. Study No. 11742.614746J, 135 p. PMRA 2060524

Lentz, Nancy R. 2010 b . [14C]Clofentezine

– Anaerobic Aquatic Sediment Metabolism, Springborn Smithers Laboratories, Wareham, Massachusetts, Sponsored by I rvita Plant

Protection N.V. c/o Makhteshim

– Agan of North America Inc. 4515 Falls of Neuse Rd., Suite 300, Raleigh, NC, USA, 27609. Study No. 11742.6148, 134 p. PMRA 2060525.

Olszak , R.W. 1999. Influence of some pesticides on mortality and fecundity of the aphidophagous coccinellid Adalia bipunctata L (Col., Coccinellidae). J. Appl. Ent.

123:41

- 45.

Samsoe

- Petersen, L. 1993. Effects of 45 Insecticides, Acaricides and Molluscicides on the Rov e Beetle Aleochara bilineata (Col.: Staphylinidae) in the Laboratory. Entomophaga 38(3):

371

- 382.

USEPA, 1990. National Survey of Pesticides in Drinking Water Wells. Report N umber: USEPA

570/9

- 90

- 015, USEPA Office of Water, Washington, DC.

US EPA, 1992. Pesticides in Ground Water Data Base. Report Number(s): PB

- 89

- 164230/XAB;

EPA

- 540/9

- 89/036, Environmental Protection Agency, Washington, DC (USA). Office of Pesticide Programs70 USEPA

, 2004. Overview of the Ecological Risk Assessment Process in the Office of Pesticide Programs . United States Environmental Protection Agency (USEPA). Environmental Fate and Effects Division. Office of Pesticide Programs. Available at http://www.epa.gov/espp/consultation/ecorisk

- overview.pdf

USEPA, 2012. EFED Problem Formulation for Clofentezine Registration Review

. Memorandum from the Environmental Fate and Effects Division to the Registration Division, Office of Pesticide Programs, Office of Chemical Safety and Pollution

Prevention. February 2, 2007.

USEPA, 2012. OCSPP 850.3020: Honey Bee Acute Contact Toxicity . Ecological Effects Test

Guideline . Office of Chemical Safety and Pollution Prevention. EPA 712

- C

- 019. January

2012.

Yoshida, T . and S. Fuchs. 1989. Blocking reproduction in Verroa jacobsoni Ou d. by feeding clofentezine with pollen to its host Apis mellifera L. J. Appl. Ent. 108:519

- 526.71 

### APPENDIX A

Clofentezine (125501) Screening Level Usage Analysis (SLUA) Date: February 17, 2012

What is a Screening Level Usage Analysis (SLUA)?

• Available estimates of pesticide usage data for a particular active ingredient that is

used on agricultural crops in the United States.

• Pesticide usage data obtained from various sources. The data are then merged, averaged, and rounded so that the present ed information is not proprietary, business confidential, or trade secret.

What does it contain?

• Pesticide usage data for a single active ingredient only.

• Agricultural use sites (crops) that the pesticide is reported to be used on.

• Available pesticide us age information from U.S. states that produce 80% or more of a crop, in most cases, or less than 80%, in rare cases, depending on the scope of the survey and available resources.

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

.

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

• Average pounds of active ingredient applied

- Values are cal culated by merging pesticide usage data sources together; averaging across all observations, then rounding. Note: If the estimated value is less than 500, then that value is labeled <500. Estimated values between 500 & <1,000,000 are rounded to 1 signif icant digit. Estimated values of 1,000,000 or greater are rounded to 2 significant digits.)

• Average percent of crop treated

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

• Maximum percent of crop treated

- Value is the single maximum value reported

across all da ta sources, across all years, & rounded up to the nearest multiple of 5.

Note: If the estimated value is less than 2.5, then the value is labeled <2.5.

What are the data sources used?

• USDA

- NASS (United States Department of Agriculture’s National Agricultural Statistics Service)

– pesticide usage data from 2003 to 2010.

• Private pesticide market research

– pesticide usage data from 2003 to 2010.

• California Department of Pesticide Regulation (DPR) Pesticide Use Reporting (PUR) data for 2003 to 2010.

What are the limitations to the data?

• Additional registered uses may exist but are not included because the available surveys do not report usage (e.g., small acreage crops).

• Lack of reported usage data for the pesticide on a crop does not imply zero usage.72 • Usage data on a particular site may be noted in data sources, but not quantified . In these instances, the site would not be reported in the SLUA.

• Non

- agricultural use sites (e.g., turf, post

- harvest, mosquito control, etc.) are not reported in the SLUA. A separate request must be made to receive these estimates.

• Some sites show some use, even though they are not on the label. This usage could be due to various factors, including, but not limited to S ection 18 requests, existing stocks of the chemical, data collection errors, and experimental use permits (EUPs).73 February 17, 2012

Screening Level Estimates of Agricultural Uses of Clofentezine (125501) Sorted Alphab etically

Crop

Lbs. A.I. Percent Crop Treated

Average Maximum

1 Almonds 3,000 <2.5 5

2 Apples 1,000 <2.5 10

3 Apricots <500 <2.5 <2.5

4 Cherries 1,000 5 10

5 Grapes <500 <1 <2.5

6 Nectarines <500 5 10

7 Peaches 1,000 5 15

8 Pears <500 5 10

9 Plums/Prunes + <500 <2.5 <2.5

10 Walnuts 2,000 5 10

All numbers rounded.

<500 Less than 500 pounds of active ingredient

<2.5 Less than 2.5 percent of crop treated

<1 Less than 1 percent of crop treated

** California data only. No information available about use of this chemical on this crop in

other states.

+ Crops not known to be listed on active end use product registrations or as Secti on 18

emergency exemptions when this report was run

SLUA data sources include:

USDA

- NASS (United States Department of Agriculture's National Agricultural Statistics Service)

Private Pesticide Market Research California DPR (Department of Pesticide Regulation)

These results reflect amalgamated data developed by the Agency and are releasable to the public.74 

### APPENDIX B

Structures of Clofent e zine Degradates75 

### APPENDIX C

PRZM /EXAMS Aquatic EECs Output File

Upper 10th Percentile Limnetic EECs in Farm Pond

Chemical - Clofentezine

Scenarios Instantaneous 96-Hour 21-Day 60-Day 90-Day Annual

RUN ID: NC1App-P

RUN ID: MI1Che-P

RUN ID: NY2Gra-P

RUN ID: PA1App-P

RUN ID: OR1Xma-P

RUN ID: GA1Pch-P

RUN ID: OR1App-P

RUN ID: CA1Wal-P

RUN ID: CA1Gra-P

RUN ID: CA1Orc-P 3.34

1.04

1.02

0.996

0.964

0.832

0.726

0.454

0.170

0.139 1.48

0.460

0.453

0.477

0.377

0.363

0.413

0.210

0.745E-01

0.642E-01 0.406

0.156

0.170

0.128

0.123

0.929E-01

0.155

0.705E-01

0.214E-01

0.173E-01 0.145

0.605E-01

0.742E-01

0.558E-01

0.430E-01

0.361E-01

0.723E-01

0.265E-01

0.862E-02

0.709E-02 0.967E-01

0.423E-01

0.514E-01

0.400E-01

0.287E-01

0.241E-01

0.490E-01

0.218E-01

0.756E-02

0.475E-02 0.239E-01

0.105E-01

0.130E-01

0.988E-02

0.902E-02

0.594E-02

0.122E-01

0.594E-02

0.204E-02

0.190E-02

Express v. 1.03.02 (2007-07-20) - Exams 2.98.04.06 with PRZM 3.12.2[48]76 

### APPENDIX D

Output from T

- Rex Model Run for Clofentezine

Acute and Chronic RQs are based on the Upper Bound

Kenaga Residues.77 Chemical Name: Clofentezine The maximum single day residue
estimation is used for

Use All both the acute and reproduction RQs.

Formulation 0

Application Rate 0.26 lbs a.i./acre RQs reported as "0.00" in the RQ

tables below should be noted as

Half

- life 15.7 days <0.01 in your assessment. This is due to rounding and significant

Application Interval 0 days figure issues in Excel.

Maximum # Apps./Year 1

Length of Simulation 1 year Variable application
rates? no

Endpoints

Avian Bobwhite quail LD50 (mg/kg

- bw) 3000.00

Bobwhite quail LC50 (mg/kg

- diet) 19900.00

Mallard

duck NOAEL(mg/k

g
- bw) 0.00

Bobwhite quail NOAEC (mg/kg

- diet) 30.00

Mammals LD50 (mg/kg

- bw) 3230.00 LC50 (mg/kg

- diet) 0.00 NOAEL (mg/kg

- bw) 2.50 NOAEC (mg/kg

- diet) 50.0078 Dietary

- based EECs (ppm) Kenaga

Values

Short Grass 62.40
Tall Grass 28.60 Broadleaf plants 35.10 Fruits/pods/seeds 3.90 Arthropods 24.44



### Avian

Results

Avian Body Ingestion (Fdry) Ingestio n (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 2161.29

100 2751.43

1000 3886.5079 Dose

- based
EECs (mg/kg

- bw) Avian Classes and Body Weights (grams)

small mid large

20 100 1000

Short Grass 71.07 40.53 18.14

Tall Grass 32.57 18.57 8.32
Broadleaf plants 39.98 22.80 10.21

Fruits/pods 4.44 2.53 1.13

Arthropods 27.83 15.87 7.11

Seeds 0.99 0.56 0.25

Dose

- based
RQs (Dose

based EEC/adjust ed LD50) Avian Acute RQs Size Class (grams)

20 100 1000

Short Grass 0.03 0.01 0.00

Tall Grass 0.02 0.01 0.00
Broadleaf plants 0.02 0.01 0.00

Fruits/pods 0.00 0.00 0.00

Arthropods 0.01 0.01 0.00

Seeds 0.00 0.00 0.0080 Dietary

- based RQs (Dietary

- based
EEC/LC50 or NOAEC) RQs

Acute Chronic

Short Grass 0.00 2.08

Tall Grass 0.00 0.95
Broadleaf plants 0.00 1.17 Fruits/pods/

seeds 0.00 0.13

Arthropods 0.00 0.81

Note: To provide risk management
with the

maximum possible information,

it is

recommende

d that both

the dose

- based and

concentration

- based
RQs be

calculated

when data are

available81 Clofentezine All Upper bound Kenaga
Residues 

## Mammalian

Results

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 7098.99 5.49
Herbivores/ 35 5743.84 4.45
insecti vores 1000 2484.39 1.92

15 7098.99 5.49
Granivores 35 5743.84 4.45

1000 2484.39 1.92

Dose

- Based EECs (mg/kg

- bw) Mammalian Classes and Body weight
(grams)

15 35 1000

Short Grass 59.49 41.12 9.53

Tall Grass 27.27 18.85 4.37 Broadleaf plants 33.47 23.13 5.36 Fruits/pods 3.72 2.57 0.60 Arthropods 23.30 16.10 3.73
Seeds 0.83 0.57 0.13

Dose

- based RQs (Dose

- based
EEC/LD50 or NOAEL) Small mammal Medium mammal Large mammal

15 grams 35 grams 1000 grams

Acute Chronic Acute Chronic Acute Chronic

Short Grass 0.01 10.83 0.01 9.25 0.00 4.96

Tall Grass 0.00 4.96 0.00 4.24 0.00 2.27 Broadleaf plants 0.00 6.09 0.00 5.20 0.00 2.79 Fruits/pods 0.00 0.68 0.00 0.58 0.00 0.31 Arthropods 0.00 4.24 0.00 3.62 0.00 1.94

Seeds 0.00 0.15 0.00 0.13 0.00 0.0782 Dietary

- based RQs (Dietary

based EEC/LC50 or NOAEC) Mammal RQs

Acute Chronic

Short Grass #DIV/0! 1.25

Tall Grass #DIV/0! 0.57 Broadleaf plants #DIV/0! 0.70 Fruits/pods/seeds #DIV/0! 0.08 Arthropods #DIV/0! 0.49

Note: To provide risk management

with the maximum possible information,

it is recommended

that both the dose

based and

concentration

based
RQs be calculated

when data are

available83 

### APPENDIX E

Output from the Screening Imbibition Program (SIP) for Clofentezine

Table 1. Inputs

Parameter Value

Chemical name Clofentezine

Solubility (in water at 25 o C; mg/L) 0.002

Mammalian LD 50 (mg/kg

- bw) 3230

Mammalian test species laboratory rat Body weight (g) of "other" mammalian species

Mammalian NOAEL (mg/kg

- bw) 20 Mammalian test species laboratory rat Body weight (g) of "other" mammalian species

Avian LD 50 (mg/kg

- bw) 3000
Avian test species mallard duck Body weight (g) of "other" avian species Mineau scaling factor 1.15

Mallard NOAEC (mg/kg

- diet) 270 Bobwhite quail NOAEC (mg/kg

- diet) 30 NOAEC (mg/kg

- diet) for other bird species Body weight (g) of other avian species

NOAEC (mg/kg

- diet) for 2nd other bird species Body weight (g) of 2nd other avian species

Table 2. Mammalian Results

Parameter Acute Chronic Upper bound exposure (mg/kg

- bw) 0.0003 0.0003 Adjusted toxicity value (mg/kg

- bw) 2484.3886 15.3832

Ratio of exposure to toxicity 0.0000 0.0000

Conclusion* Drinking water exposure alone is NOT a potential

concern for mammals Drinking water exposure alone is NOT a potential

concern for mammals84 Table 3. Avian Results

Parameter Acute Chronic
Upper bound exposure (mg/kg

- bw) 0.0016 0.0016 Adjusted toxicity value (mg/kg

- bw) 1557.6762 3.1889 Ratio of exposure to acute toxicity 0.0000 0.0005

Conclusion* Drinking water exposure alone is NOT a potential

concern for birds Drinking water exposure
alone is NOT a potential

concern for birds

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

- target animals.85 

### APPENDIX F

Output from the Screening Tool for Inhalation Risk (STIR) for Clofentezine



## Welcome to the EFED Screening Tool for Inhalation Risk

This tool is designed to provide the risk assessor with a rapid method for determining the potential significance of the inhalation exposure route to birds and mammals in a risk

assessment.



## Input

Application and Chemical Information

Enter Chemical Name Clofentezine

Enter Chemical Use all Is the Application a Spray? (enter y or n) y If Spray What Type (enter ground or air) ground Enter Chemical Molecular Weight (g/mole) 303.15 Enter Chemical Vapor Pressure (mmHg) 9.75E

- 10 Enter Application Rate (lb a.i./acre)

Toxicity Properties

**Bird**

Enter Lowest Bird Oral LD 50 (mg/kg bw) 3000 Enter Mineau Scaling Factor 1.15 Enter Tested Bird Weight (kg) 1.58

**Mammal**

Enter Lowest Rat Oral LD 50 (mg/kg bw) 3200

Enter Lowest Rat Inhalation LC 50 (mg/L) 9.08 Duration of Rat Inhalation Study (hrs) 6 Enter Rat Weight (kg) 0.3586 

## Output

Results Avian (0.020 kg )
Maximum Vapor Concentration in Air at Saturation (mg/m 3 ) 1.59E

- 05

Maximum 1

- hour Vapor Inhalation Dose (mg/kg) 2.00E

- 06

Adjusted Inhalation LD 50 5.13E+01

Ratio of Vapor Dose to Adjusted Inhalation LD 50 3.90E

- 08 Exposure not Likely Significant

Maximum Post

- treatment Spray Inhalation Dose (mg/kg) 0.00E+00 Ratio of Droplet Inhalation Dose to Adjusted Inhalation

LD 50 0.00E+00 Exposure not Likely Significant

Results Mammalian (0.015 kg )
Maximum Vapor Concentration in Air at Saturation (mg/m 3 ) 1.59E

- 05

Maximum 1

- hour Vapor Inhalation Dose (mg/kg) 2.51E

- 06

Adjusted Inhalation LD 50 8.11E+02

Ratio of Vapor Dose to Adjusted Inhalation LD 50 3.10E

- 09 Exposure not Likely Significant

Maximum Post

- treatment Spray Inhalation Dose (mg/kg) 0.00E+00 Ratio of Droplet Inhalation Dose to Adjusted Inhalation

LD 50 0.00E+00 Exposure not Likely Significant87 

### APPENDIX G

Results of ECOTOX Literature Search for Clofentezine

O pen literature studies with toxicity data on clofentezine were identified using EPA’s ECOTOXicology database ( ECOTOX) ( USEPA, 2007 c ), which employs a literature search engine for locating chemical toxicity data for aquatic life, terrestrial plants, and wildlife.

Accepted for EcoT ox and OPP

Bostanian, N. J., Vincent, C., Pitre, D., and Simard, L. G. (1989). Chemical Control of Key and Secondary Arthropod Pests of Quebec Apple Orchards. Appl. Agric. Res. 4(3): 179

- 184.

EcoReference No.: 89749 Chemical of Concern: ACYP,AZ,BFT,CHX,CTZ,CYH,CYP,DM,FNV,FVL,HTX,OTQ,TDC; Habitat: T;

Effect Codes : POP; Code: LITE EVAL CODED (AZ,BFT,CTZ,CYH,CYP,DM,FNV,FVL,HTX,TDC), NO EFED CHEM (ACYP,CHX,OTQ)

Easterbrook, M. A. (1984). Effects of Pesticides on the Apple Rust Mite Aculus schlechtendali (Nal.) (Eriophyidae).

J. Hortic. Sci. 59(1): 51

- 55.

EcoReference No.: 71031

Chemical of Concern:
AMZ,CBL,CHX,CPY,CTZ,DCF,DFZ,ES,FPP,FRM,MZB,PHSL,PIRM,PPG,SFR,TDF, TFR; Habitat: T;

Effect Codes : POP; Code: LITE EVAL CODED (AMZ,CBL,CTZ,DCF,DFZ,FPP,FRM,MZB,PIRM,PPG,SFR,TDF,TFR), NO EFED CHEM (CHX,PHSL), TARGET (CPY,ES)

Fouche, C., Verdegaal, P., Duncan, R., and Cutter, D. (1998). Evaluation of Acaricides for Contro l of Spider Mites on Almonds and Impact on Two Beneficial Arthropods, 1997. Arthropod Manag. Tests 23: 59

- (1D).

EcoReference No.: 150672 Chemical of Concern: ABM,CFP,CTZ,EXZ,HTX,NMO,PPG,PRB; Habitat: T; Effect Codes : POP; Code: LITE EVAL CODED (CTZ), NO E FED CHEM (EXZ), OK (ABM,CFP,HTX,NMO,PPG,PRB)

Goodwin, S. (1984). Laboratory Evaluation of Pesticides on an Australian Strain of the Chilean Predatory Mite, Phytoseiulus persimilis Athias

- Henriot. In: D.A.Griffiths and C.E.Bowman (Eds.), Acarology VI, V ol. 2,
Ellis Horwood, Chichester, UK 2: 647

- 654.

EcoReference No.: 94828

Chemical of Concern: AZ,BMY,BTN,CHX,CPY,CTZ,Captan,DCF,DIE,DMT,DZ,ES,FBOX,FNV,FO,IPD,MDT,MLN,MZB,OT Q,OXC,PIM,PMR,PPG,SFR,TCF,TDF,TFR,VCZ; Habitat: T; Effect Codes : MOR,REP; Code: LIT E

EVAL CODED (AZ,BMY,CPY,CTZ,Captan,DCF,DMT,DZ,ES,FBOX,FNV,IPD,MDT,MLN,MZB,PIM,PMR,PPG,SFR,T CF,TDF,TFR,VCZ), NO EFED CHEM (BTN,CHX,DIE,OTQ,OXC)

Olszak, R. W. (1999). Influence of Some Pesticides on Mortality and Fecundity of the Aphidophagous Coccinelli d Adalia bipunctata L. (Col., Coccinellidae). Z. Angew. Entomol. 123(1): 41

- 45.

EcoReference No.: 64265

Chemical of Concern:
ACYP,AMZ,CTZ,DFC,DOD,EFV,ES,FBOX,FO,FPP,FRM,FUZ,HTX,IPD,MEM,MZB,PHSL,PPG,TFR, TFZ,VCZ; Habitat: T; Effect Codes : MOR,REP; Code: LIT E EVAL CODED (DOD,EFV,ES,FRM,FUZ,IPD,MEM,MZB,VCZ,CTZ), NO EFED CHEM (ACYP,DFC,PHSL), NO ENDPOINT (HTX,TFZ), TAR

Samsoe

- Petersen, L. (1993). Effects of 45 Insecticides, Acaricides and Molluscicides on the Rove Beetle Aleochara88 bilineata (Col.: Staphylinid ae) in the Laboratory. Entomophaga 38(3): 371

- 382.

EcoReference No.: 63489

Chemical of Concern:
ACP,AMZ,AZ,BPZ,CBL,CPY,CTZ,CYF,CYP,CYR,DFZ,DM,DMT,DZ,FNT,FPP,FVL,FYC,HTX,KSP,L CYT,MAL,MCB,MTM,MVP,OML,OTQ,PIM,PMR,PPHD,PSM,THO; Habitat: T; Effect Codes : MOR, REP; Code: LITE EVAL CODED (CBL,CPY,CTZ,CYF,CYP,CYR,DFZ,DMT,DZ,FPP,FVL,FYC,HTX,KSP,LCYT,MAL,MCB,MTM,MVP ,OML,PIM,PMR,PSM), NO EFED CHEM (BPZ,OTQ,PPHD,THO), NO PUBL AS (ACP,AMZ,AZ,DM,FNT), TARGET (AMZ,AZ,DM,FNT)

Urbaneja, A., Pascual

- Ruiz, S., Pina, T., A bad

- Moyano, R., Vanaclocha, P., Monton, H., Dembilio, O., Castenera, P., and Jacas, J. A. (2008). Efficacy of Five Selected Acaricides Against Tetranychus urticae (Acari: Tetranychidae) and Their Side Effects on Relevant Natural Enemies Occurring in Citrus Orchards. Pest Manag. Sci. 64(8): 834

- 842.

EcoReference No.: 154868 Chemical of Concern: ALSV,CTZ,FBOX,FZQ,MOIL,TFY; Habitat: T; Effect Codes : MOR,POP,REP;

Code: LITE EVAL CODED (ALSV,CTZ,FBOX,FZQ,MOIL,TFY), NO EFED CHEM (TFY)

Yoshida, T. and Fuchs, S . (1989). Blocking Reproduction in Varroa jacobsoni Oud. by Feeding Clofentezin with Pollen to Its Host Apis mellifera L. J. Appl. Entomol. : 519

- 526.

EcoReference No.: 154863 Chemical of Concern: CTZ; Habitat: T; Effect Codes : GRO,MOR,REP; Code: LITE EVAL CODED (CTZ)

Papers not Accepted for ECOTOX

Hull, L. A. and Krawczyk, G. (1998). Tufted Apple Bud Moth Control Tactics for Apple, 1997. Arthropod Manag.

Tests 23: 22

- 26 (15A).

EcoReference No.: 150741 Chemical of Concern: ABM,ALSV,CTZ,IMC,MFZ ,MOIL,MOM,MP,PYX,SS,TUZ; Habitat: T; Effect

Codes : POP; Code: NO EFED CHEM (SS), NO MIXTURE (ABM,CTZ,IMC,MFZ,MOM,MP,TUZ), TARGET (ALSV,MOIL,PYX,TUZ)

Longhurst, C., Bacci, L., Buendia, J., Hatton, C. J., Petitprez, J., and Tsakonas, P. (1992). Fenazaqui n, a Novel Acaricide for the Management of Spider Mites in a Variety of Crops. In: Br.Crop Prot.Counc., Brighton Crop Prot.Conf.: Pests and Diseases, Vol.1

- 3, Int.Conf., Nov.23

- 26, 1992, Brighton, England, UK, Br.Crop Prot.Counc.(BCPC), Farnham, England, U K : 51

- 58.

EcoReference No.: 106270 Chemical of Concern: BFT,CTZ,DCF,FBOX,FPP,FZQ,HTX,PPG; Habitat: T; Effect Codes : PHY,POP;

Code: NO CONTROL (BFT,CTZ), NO ENDPOINT (FBOX,HTX,PPG), OK (DCF,FPP,FZQ)

Maciesiak, A. and Olszak, R. W. (1999). Effectiveness of Acaricide Mixtures in the Control of Phytophagous Mites on Apple Trees. J. Fruit Ornam. Plant Res. 7(2): 91

- 96.

EcoReference No.: 97506 Chemical of Concern: AMZ,CTE,CTZ,HTX,PPG; Habitat: T; Effect Codes : POP; Code: LITE EVAL CODED (PPG), NO MIXTURE (AM Z,CTZ), TARGET (HTX)

Somerville, L., Challis, I. R., and Needham, D. (1989). Relevance of Kinetic and Metabolic Data to the Interpretation of Toxicological Findings. Food Addit. Contam. 6(1): 33

- 39.

EcoReference No.: 150077 Chemical of Concern: CTZ; Hab itat: T; Effect Codes : ACC; Code: NO CONTROL (CTZ), NO ENDPOINT (CTZ)

Van Leeuwen, T., Stillatus, V., and Tirry, L. U. C. (2004). Genetic Analysis and Cross

- Resistance Spectrum of a Laboratory

- Selected Chlorfenapyr Resistant Strain of Two

- Spotted Spide r Mite (Acari: Tetranychidae).89 Exp. Appl. Acarol. 32(4): 249

- 261.

EcoReference No.: 75967 Chemical of Concern: AMZ,BFT,CFP,CTZ,DMT,PPB,SDF; Habitat: T; Effect Codes : MOR; Code: NO CONTROL (AMZ,BFT,CFP,CTZ,DMT,SDF), NO MIXTURE (PPB)