OFFICE OF CHEMICAL SAFETY AND POLLUTION PREVENTION

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON D.C., 20460

PC Code: 090205

DP Barcode: 406269, 410639

November 12, 2013

MEMORANDUM

SUBJECT: Environmental Fate and Ecological Risk Assessment for the Section 3 New 

Chemical Registration of Ethaboxam

TO: Tony Kish, Risk Manager

Dominic Schuler, Risk Manager Reviewer 

Registration Division (7505P)

FROM: Elizabeth Riley, Biologist

Andrew Shelby, Environmental Scientist

Mark Corbin, Branch Chief

Environmental Risk Branch VI

Environmental Fate and Effects Division (7507P)

The Environmental Fate and Effects Division (EFED) has completed the screening level 

assessment of the environmental fate and ecological risks of the proposed new chemical 

ethaboxam (V-10208 3.2 Fungicide, PC Code 090205). This assessment is for a national 

registration request for the following uses: legume vegetables (except cowpea and field pea), 

cereal grains (except rice and wild rice), and the rapeseed subgroup. This assessment applies to 

the proposed ethaboxam end-use product, V-10208 3.2 Fungicide, for use as a seed treatment 

and will not be applicable to proposed foliar uses. 

Summary of Risk Conclusions

The results of this screening-level assessment on the proposed ethaboxam seed treatment uses 

indicate that risks of adverse effects to non-target organisms are not expected for aquatic and 

terrestrial plants and animals. These results are summarized in the body of the document in 

Section 1.2. 

Uncertainties

Submitted environmental fate studies represent application methods relevant to broadcast 

applications rather than seed treatments, the use pattern relevant to this new chemical 
-Page 2 of 68-

registration. The formulation applied to the seed and interaction with the seed coat can impact 

the degradation and mobility of ethaboxam. In the absence of field or laboratory data 

demonstrating ethaboxam fate and transport on seed treatments, the rate and route of ethaboxam 

dissipation are uncertainities.

Major degradates of ethaboxam are structurally similar to ethaboxam and are conservatively 

assumed to be toxic residues. Degradation estimates cannot be made because concentrations of 

degradate increase to study termination. An aged column leaching study indicates that 

degradates can leach through soil but further characterization of degradate mobility is not 

possible without further data. In the absence of specific degradate fate and transport data, the 

rate and route of ethaboxam degradate dissipation are uncertainties.

Submitted metabolism studies use only an acetone extraction and unextracted residues in aerobic 

soil metabolism studies are 55% to 70% of applied radioactivity by study termination. Without 

demonstrating additional extractions, the bioavailability of these unextracted residues is an 

uncertainty. An aerobic soil metabolism study employing additional extraction techniques is 

being submitted and preliminary results indicate lower unextracted residues. The results of this 

study have potential to reduce uncertainity associated with the unextracted residues.

Data Gaps

835.4100 Aerobic Soil Metabolism – Currently submitted studies do not deomonstrate 

sufficient attempts to extracted unextracted residue. The registrant has indicated a new aerobic 

soil metabolism study with more exhaustive extraction techniques has been conducted but the 

study has not yet been submitted.

835.6100 Terrestrial Field Dissipation – The registrant maintains that detection limits are not 

sufficient to conduct a terrestrial field dissipation study at current labeled rates for this seed 

treatment. The study remains a data gap pending improved detection limits. 

850.1350 Estuarine/Marine Invertebrate Chronic Toxcicity – An acceptable chronic toxicity 

study with an estuarine/marine invertebrate species is not available. In the absence of the data an 

an acute-to-chronic ratio (ACR) based on the daphnid is applied. The ACR is considered 

protective for the purpose of this risk assessment; however, the application of an ACR in the 

absence of actual data does introduce uncertainty to the risk assessment.

850.4100 Terrestrial Plant Seedling Emergence – The registrant submitted data waiver 

requests for both the seedling emergence (MRID 48535704), citing ethaboxam’s low field 

application rates as a seed treatment, relatively rapid soil half-life (1.5 to 6.1 days depending on 

the soil), and fungicidal mechanism of action. While the Agency did not grant the waiver request 

for the seedling emergence data because ethaboxam is chemically active during seed germination 

and may be transmitted off-site via run-off, supporting data provided by the registrant on seed 

germination in the presence of ethaboxam (memo data 10/15/2012) suggest that the relatively 

low application rate of ethaboxam as a seed treatment does not inhibit seed germination. 

However, both seedling emergence and vegetative vigor data would be necessary should the 

registrant submit a future registration request for an above-ground spray application of 

ethaboxam. 
-Page 3 of 68-

850.4400/5400 Vascular and Non-Vascular Aquatic Plant Toxicity – CFR 40 Part 158 

requires toxicity tests using four species of non-vascular plants and one species of vascular plant. 

Currently, data have only been submitted for one species of non-vascular plant. Additional data 

located on the Footprint database suggest that ethaboxam has highly variable toxicity to aquatic 

non-vascular species. While exposure from the seed treatment use is low, data for additional 

species of non-vascular plants should be submitted. 
-Page 4 of 68-

Environmental Fate and Ecological Risk Assessment 

for the Registration of Ethaboxam

Ethaboxam

N-(cyano-2-thienylmethyl)-4-ethyl-2-(ethylamino)-5-thiazolecarboxamide

CAS Registry Number: 162650-77-3

PC Code: 090205

Prepared by:

Elizabeth A. Riley, Biologist

Andrew Shelby, Environmental Scientist

U. S. Environmental Protection Agency

Office of Pesticide Programs

Environmental Fate and Effects Division

Environmental Risk Branch IV

1200 Pennsylvania Ave., NW

Mail Code 7507P

Washington DC 20460

Reviewed by:

Stephen Carey, Biologist, ERB VI

William P. Eckel, Ph.D, Senior Science Advisor, ERB VI

Mark Corbin, Branch Chief, ERB VI

Date: September 19, 2012

Table of Contents
-Page 5 of 68-

1. Executive Summary.............................................................................................................. 7

1.1. Nature of Chemical Stressor....................................................................................................................7

1.2. Potential Risks to Non-target Organisms...............................................................................................7

1.3. Conclusions - Exposure Characterization ..............................................................................................8

1.4. Conclusions - Effects Characterization...................................................................................................8

2. Problem Formulation ........................................................................................................... 9

2.1. Nature of Regulatory Action..................................................................................................................10

2.2. Stressor Source and Distribution ..........................................................................................................10

2.2.1. Nature of Chemical Stressor..............................................................................................................10

2.2.2. Overview of Pesticide Usage.............................................................................................................11

2.3. Receptors.................................................................................................................................................11

2.3.1. Aquatic and Terrestrial Effects..........................................................................................................11

2.3.2. Ecosystems Potentially at Risk..........................................................................................................12

2.4. Assessment Endpoints............................................................................................................................12

2.5. Conceptual Model ...................................................................................................................................13

2.5.1. Risk Hypotheses................................................................................................................................13

2.5.2. Conceptual Diagram..........................................................................................................................13

2.6. Analysis Plan ...........................................................................................................................................15

2.6.1. Residues of Concern..........................................................................................................................15

2.6.2. Preliminary Identification of Data Gaps and Uncertainties...............................................................15

2.6.3. Evaluation of Multiple Active Ingredients and Mixtures..................................................................16

2.6.4. Measures of Exposure .......................................................................................................................16

2.6.5. Measures of Effect.............................................................................................................................17

2.6.6. Integration of Exposure and Effects..................................................................................................18

3. Analysis............................................................................................................................. 19

3.1. Use Characterization..............................................................................................................................19

3.2. Exposure Characterization....................................................................................................................20

3.2.1. Environmental Fate and Transport Characterization .........................................................................20

3.2.2. Measures of Aquatic Exposure..........................................................................................................24

3.2.3. Measures of Terrestrial Exposure......................................................................................................28

3.3. Ecological Effects Characterization......................................................................................................30

3.3.1. Aquatic Toxicity Assessment ............................................................................................................30

3.3.2 Terrestrial Effects Characterization...................................................................................................35

4. Risk Characterization......................................................................................................... 39

4.1. Risk Estimation.......................................................................................................................................39

4.1.1. Aquatic Organisms............................................................................................................................39

4.1.2. Terrestrial Organisms........................................................................................................................40

4.2. Risk Description......................................................................................................................................42

4.2.1 Exposure to Aquatic Organisms........................................................................................................42

4.2.2 Risks to Aquatic Animals..................................................................................................................43

4.2.3 Risks to Aquatic Plants......................................................................................................................43

4.2.4. Exposure to Terrestrial Organisms....................................................................................................44

4.2.5. Risks to Mammals.............................................................................................................................44

4.2.6. Risk to Birds......................................................................................................................................44

4.2.7. Potential Effects on Terrestrial Invertebrates....................................................................................44

4.2.8. Risk to Terrestrial Non-target Plants.................................................................................................45

4.3. Uncertainties and Data Gaps.................................................................................................................45

4.3.1. Fate and Transport Uncertanties........................................................................................................45

4.3.2. Effects Uncertainties .........................................................................................................................46

5. Federally Threatened and Endangered (Listed) Species Concerns............................... 46

5.1. Action Area .............................................................................................................................................47

5.2. Taxonomic Groups Potentially at Risk.................................................................................................47
-Page 6 of 68-

5.2.1. Probit Dose-Response Analysis ......................................................................................................49

5.2.2. Listed Species Occurrence Associated with Ethaboxam Use.......................................................50

6. References............................................................................................................................ 50

6.1. Submitted Environmental Fate and Transport Studies.....................................................................51

6.2. Submitted Ecotoxicity Studies..............................................................................................................51

Appendix A. Summary of Environmental Fate Data .............................................................. 52

Appendix B. Aquatic Model Input/Output Data. ................................................................... 53

Appendix C. Model Outputs...................................................................................................... 56

Appendix D Ethaboxam and Degradate ECOSAR Estimates................................................ 59
-Page 7 of 68-

1. Executive Summary

1.1. Nature of Chemical Stressor

Valent is seeking registration for a product containing the new chemical fungicide ethaboxam

(V-10208 3.2 FS Fungicide; N-(cyano-2-thienylmethyl)-4-ethyl-2-(ethylamino)-5-

thiazolecarboxamide; CAS#: 162650-77-3; PC code: 090205). Ethaboxam disrupts microtubules 

and inhibits nuclear migrations from the cyst into the germ tube. It is proposed for use in 

protecting emerging seedlings from pathogenic oomycetes including those in the Phytopthora 

and Pythium groups. 

This seed treatment assessment is for a national registration request for the following uses: 

legume vegetables (except coypeas and field peas), cereal grains (except rice and wild rice), and 

the rapeseed subgroup. Maximum application rates of the active ingredient, ethaboxam, range 

from 0.0006 to 0.062 lbs a.i./A/yr. This assessment is based on proposed maximum application 

rates for all uses. 

One end-use formulation of ethaboxam applied as a flowable suspension to seed (34.2% a.i.) is

proposed for registration in the United States. As a seed treatment, ethaboxam may be combined 

with multiple active and inert ingredients on the same seed. This risk assessment applied to the 

proposed end-use forumation of ethaboxam and is not applicable if the formulation is used in 

conjunction with other active or inert ingredients. 

Ethaboxam maintains much of its chemical structure in many of its degradation products. LGC32533 and LGC-32525 are major degradates formed in abiotic and biotic degradation studies that 

are structurally the same as parent ethaboxam aside for the substitution of the cyanide group for 

an oxide or amide group, respectively. LGC-32799 is another major degradate but is only 

distinguished from parent ethaboxam by a double bond forming to the nitrogen on the bridge 

proximate to the thiophene group. Unidentified degradates exceeded 10% in soil photolysis, 

aqueous photolysis, and aerobic soil metabolism studies and could be structurally similar to 

parent ethaboxam. Major and minor degradates that significantly differ from ethaboxam have 

been identified as well. Only the thiazole and thiophene rings are maintained in the abiotic 

degradation products LGC-32523 and LGC-35525, respectively.

1.2. Potential Risks to Non-target Organisms

The results of this screening-level assessment on the proposed ethaboxam uses indicate that risks

of adverse effects to non-target organisms are not expected for terrestrial and aquatic plants and 

mammals. 

Table 1.1. Potential Effects to Federally Listed Taxa Associated with Direct or Indirect 

Effects from the Proposed New Uses of Ethaboxam.

Listed Taxon Direct Effects Indirect Effectsa

Terrestrial and semi-aquatic plants - monocots No No

Terrestrial and semi-aquatic plants - dicots No No
-Page 8 of 68-

Listed Taxon Direct Effects Indirect Effectsa

Birds No No

Terrestrial-phase amphibians and reptiles No No

Mammals No No

Aquatic nonvascular plants No No

Aquatic vascular plants No No

Freshwater fish No No

Aquatic-phase amphibians No No

Freshwater crustaceans No No

Mollusks No No

Marine/estuarine fish No No

Marine/estuarine invertebrates No No a

direct effects are not expected for any taxa, therefore, indirect effects are not expected either.

1.3. Conclusions - Exposure Characterization 

Ethaboxam is moderately to slightly mobile in soil and is not expected to be volatile. Laboratory 

studies indicate ethaboxam degrades readily in soil (aerobic soil metabolism half-lives ranging 

from 1 to 10 days), but may persist longer if it reaches water (stable to hydrolysis; aquatic 

metabolism half-lives ranging from 1 to 2 months). However, the total toxic residues of 

ethaboxam (structurally-similar degradates) may persist in soil with half-lives of one to several 

months. Because of the seed formulation, incorporation on planting, and low application rates, 

the potential of off-site concentrations of toxic residues at levels that are toxic to nontarget 

organisms is expected to be low.

Ethaboxam maintains much of its chemical structure in many of its degradation products. LGC32533 and LGC-32525 are major degradates formed in abiotic and biotic degradation studies that 

are structurally the same as parent ethaboxam aside for the substitution of the cyanide group for 

an oxide or amide group, respectively. LGC-32799 is another major degradate but is only 

distinguished from parent ethaboxam by a double bond forming to the nitrogen on the bridge 

proximate to the thiophene group. Unidentified degradates exceeded 10% in soil photolysis, 

aqueous photolysis, and aerobic soil metabolism studies and could be structurally similar to 

parent ethaboxam. Major and minor degradates that significantly differ from ethaboxam have 

been identified as well. Only the thiazole and thiophene rings are maintained in the abiotic 

degradation products LGC-32523 and LGC-35525, respectively. Data are unavailable for the 

transport and mobility of degradates. However, those that are structurally similar to parent 

ethaboxam are expected to have similar mobility.

Model input parameter calculations conservatively include all non-CO2 extractable residue to 

account for all potentially toxic residues. Unextracted residues are not included in model input 

parameter calculations because a pending study submission indicates unextracted residues persist 

despite harsh extraction techniques. 

1.4. Conclusions - Effects Characterization 

Risks to aquatic systems from acute and chronic exposure to this ethaboxam are expected to be 

low. While ethaboxam is classified as “highly toxic” to aquatic invertebrates and “moderately”
-Page 9 of 68-

toxic to fish, across the freshwater and estuarine/marine systems, exposure for the seed treatment 

uses is expected to be sufficiently low so as to not trigger risk concerns. Aquatic plant data were 

only submitted for one species of freshwater algae. The 96-hour EC50 and NOAEC values for 

Psuedokirchinella subcapitata were >3.6 and 1.8 mg a.i./L. Data available in the Footprint 

database1 provide a 72-hour EC50 value of 0.009 mg a.i./L for the freshwater algae Raphidocelis 

subcapitata and suggest that ethaboxam has widely variable toxicity to different species of nonvascular aquatic plants. This study should be submitted to the Agency for review. Data are not 

available for a vascular aquatic species. 

Based on the available acute toxicity data, no mortality was observed in any of the mammalian 

studies conducted on ethaboxam technical at the highest concentrations/doses tested; as such, 

ethaboxam is categorized as “practically nontoxic” to mammals on an acute exposure basis.

Ethaboxam is also categorized as “practically non-toxic” to zebra-finch, bobwhite quail, and 

mallard duck on an acute aroal and subacute dietary basis. Treatment-related sublethal effects 

were observed in mallard duck and bobwhite quail studies at the highest concentrations tested. 

Sublethal effects included a decrease in food consumption and weight gain. 

Results of a registrant submitted acute toxicity test with honey bees suggest that ethaboxam is 

practically non-toxic on both a contact and oral basis (LD50 > 118 ug a.i./bee). However, 

additional data located in the Footprint database suggest that ethaboxam is toxic to honey bees, at 

least on a contact exposure basis (LD50 = 51 ug a.i./bee). In addition, results of an acute study 

with earthworms yielded a 14-day LC50 value greater than 1000 mg ai/kg dw soil (MRID 

48535628; Supplemental). While there are uncertainties in the actual exposure, results of this 

study indicate that ethaboxam is practically non-toxic to soil-dwelling invertebrates. 

Terrestrial plant data are not available for ethaboxam. The registrant submitted data waiver 

requests for both the seedling emergence and vegetative vigor data requirements (MRIDs 

48535704 and 48535705, respectively), citing ethaboxam’s low field application rates as a seed 

treatment, relatively rapid soil half-life (0.9 to 9.6 days depending on the soil), and fungicidal 

mechanism of action. While the Agency did not grant the waiver request for the seedling 

emergence data because ethaboxam is chemically active during seed germination and may be 

transmitted off-site via run-off, supporting data provided by the registrant on seed germination in 

the presence of ethaboxam (memo data 10/15/2012) suggest that the relatively low application 

rate of ethaboxam as a seed treatment does not inhibit seed germination. The Agency granted 

the waiver request for the vegetative vigor data because the seed treatment use is likely to result 

in limited exposure to plant foliage. However, seedling emergence and vegetative vigor data 

would be necessary should the registrant submit a future registration request for an above-ground 

spray application of ethaboxam. 

2. Problem Formulation

The purpose of problem formulation is to provide the foundation for the environmental fate and 

ecological risk assessment for the registration of the new chemical ethaboxam (N-(cyano-2-

 1 The Footprint database for ethaboxam may be accessed at http://sitem.herts.ac.uk/aeru/iupac/270.htm.
-Page 10 of 68-

thienylmethyl)-4-ethyl-2-(ethylamino)-5-thiazolecarboxamide; CAS#: 162650-77-3; PC code: 

090205). The problem formulation sets the objectives for the risk assessment, establishes a risk 

hypothesis and conceptual model depicting potential risk, and provides a plan for analyzing the 

data and characterizing the risk associated with the proposed use of ethaboxam (USEPA, 1998). 

2.1. Nature of Regulatory Action

The U.S. Environmental Protection Agency (EPA or the Agency) is required under the Federal 

Insecticide, Fungicide, and Rodenticide Act (FIFRA) to ensure that the newly proposed use of

ethaboxam as a fungicide does not have the potential to cause unreasonable adverse effects to the 

environment. In addition to non-target animals and plants, potential effects to listed species (i.e., 

species on the Federal list of endangered and threatened wildlife and plants) and their designated 

critical habitat are also considered under the Endangered Species Act (ESA) in order to ensure 

that the registration of ethaboxam is not likely to jeopardize the continued existence of listed 

species or adversely modify their critical habitat. In order to meet the requirements of FIFRA 

and the ESA, this assessment follows EPA guidance on conducting ecological risk assessments 

(USEPA, 1998) and Office of Pesticide Program’s Overview Document, which contains 

guidance for assessing pesticide risks to non-target and listed organisms (USEPA, 2004).

The end result of the EPA pesticide registration process (i.e., the FIFRA regulatory action) is an 

approved (or disapproved) product label. The label is a legal document that stipulates how and 

where a given pesticide may be used. Product labels (also known as end-use labels) describe the 

formulation type (e.g., liquid or granular), acceptable methods of application, approved use sites, 

and any restrictions on how applications may be conducted. Therefore, the use, or potential use, 

described by the pesticide’s labels is considered “the action” being assessed. This assessment 

was prepared to support evaluation of the proposed new chemical registration of ethaboxam.

2.2. Stressor Source and Distribution

2.2.1. Nature of Chemical Stressor

Valent is seeking registration for the use of the new chemical fungicide ethaboxam (V-10208 FS 

Fungicide), N-(cyano-2-thienylmethyl)-4-ethyl-2-(ethylamino)-5-thiazolecarboxamide. 

According to Valent, ethaboxam works by distrupting microtubules and inhibiting nuclear 

migrations from the cyst into the germ tube. It is proposed for use in protecting emerging 

seedlings from pathogenic oomycetes including those in the Phytopthora and Pythium groups. 

Ethaboxam is formulated as a flowable suspension that will be used to coat certain crop seeds 

(V-10208 FS Fungicide®). It is applied to legume vegetables (except cow peas and field peas), 

cereal grains (except rice and wild rice), and crops in the rapeseed subgroup. 

The proposed maximum annual application rates on legume vegetables are the highest of the new 

uses. Legumes may be treated with a single maximum application rate of 0.062 lbs a.i./A. Other 

crop treatments are proposed at lower seasonal rates as discussed in Section 3.1. 
-Page 11 of 68-

Parent ethaboxam and all non-CO2 degradates are conservatively considered the chemical 

stressor in a total toxic residue approach. Unextracted residues are not included in total toxic 

residues.

2.2.2. Overview of Pesticide Usage

Usage data are not available for ethaboxam because it is a new active ingredient proposed for use 

in the United States.

Ethaboxam may be applied to seed using mechanical, slurry, or mist-type seed treatment 

equipment, provided that the equipment is calibrated for accurate and uniform application. The 

following labeling statements appear on the proposed label to avoid contamination of aquatic 

enviornments:

ENVIRONMENTAL HAZARD STATEMENTS 

• This pesticide is extremely toxic to fish, aquatic invertebrates, oysters and shrimp. Do not 

discharge effluent containing this product into lakes, streams, ponds, estuaries, oceans, or 

other waters unless in accordance with the requirements of a National Pollutant 

Discharge Elimination System (NPDES) permit and the permitting authority has been 

notified in writing prior to discharge. Do not discharge effluent containing this product 

into sewer systems without previously notifying the local sewage treatment plant 

authority. For guidance contact your State Water Board or Regional Office of the EPA. 

In addition, the proposed label requires the following statements on appear on the container of 

seed treated with V-10208 3.2 FS Fungicide: “Treated seeds exposed on the soil surface may be 

hazardous to wildlife. Cover or collect treated seeds spilled during loading. 

2.3. Receptors

2.3.1. Aquatic and Terrestrial Effects

In ecological risk assessment, a receptor is a biological entity that is exposed to a stressor 

(USEPA, 1998). Consistent with the process described in the Overview Document (USEPA, 

2004), this risk assessment uses a surrogate species approach in its evaluation of ethaboxam. 

Toxicity data generated using surrogate test species, which are intended to be representative of 

broad taxonomic groups, are used to infer potential effects on a variety of species (receptors) 

included under these broader taxonomic groupings. Table 2.1 provides the general taxonomic 

groups and surrogate species tested to evaluate potential ecological effects of ethaboxam to 

broad classes of non-target organisms. Within each of these taxonomic groups, a measure of 

effect is selected from among the available test data. 
-Page 12 of 68-

Table 2.1. Taxonomic Groups and Test Species Evaluated for Assessing Potential 

Ecological Effects of Ethaboxam.

Taxonomic Group Typical Species

Birds1 Mallard duck (Anas platyrhynchos)

Bobwhite quail (Colinus virginianus)

Mammals Norway rat (Ratus norvegicus)

Terrestrial Invertebrates Honey bee (Apis mellifera L.)

Freshwater fish2 Bluegill sunfish (Lepomis macrochirus)

Rainbow trout (Oncorhynchus mykiss)

Fathead minnow (Pimephales promelas)

Freshwater invertebrates Water flea (Daphnia magna)

Midge (Chironomus riparius)

Estuarine/marine fish Sheepshead minnow (Cyprinodon variegatus)

Estuarine/marine invertebrates Mysid (Americamysis bahia)

Eastern oyster (Crassostrea virginica)

Terrestrial plants3 Monocots – Crop species, such as corn (Zea mays)

Dicots – Crop Species, such as soybean (Glycine max)

Aquatic plants and algae4 Duckweed (Lemna gibba) 

Freshwater Algae (e.g., Pseudokirchneriella

subcapitata) 1 Birds represent surrogates for terrestrial-phase amphibians and reptiles. 2 Freshwater fish may be surrogates for aquatic-phase amphibians. 3 Four species of two families of monocots, of which one is corn; six species of at least four dicot families, of which one is soybeans. 4 Four species of non-vascular algae including a freshwater green algae, a cyanobacterium, a marine diatom, and a freshwater diatom. 

2.3.2. Ecosystems Potentially at Risk 

The ecosystems potentially at risk are often extensive in scope; therefore, it may not be possible 

to identify specific ecosystems during the development of a nation-wide ecological risk 

assessment. However, in general terms, terrestrial ecosystems potentially at risk could include 

the treated field and immediately adjacent areas that may receive runoff. As a seed treatment, 

exposure to drift is not likely. Areas adjacent to the treated field could include cultivated fields, 

fencerows and hedgerows, meadows, fallow fields or grasslands, woodlands, riparian habitats, 

and other uncultivated areas. Aquatic ecosystems potentially at risk include water bodies 

adjacent to or downstream from use sites, and might include impounded bodies such as ponds, 

lakes and reservoirs, or flowing waterways such as streams or rivers including all adjacent offchannel habitats that are permanently or intermittently connected to flowing waters. For uses in 

coastal areas, aquatic habitat also includes marine ecosystems, including estuaries, embayments, 

and near-shore environments such as tidal marshes.

2.4. Assessment Endpoints

Assessment endpoints represent the actual environmental value that is to be protected, defined by 

an ecological entity (species, community, or other entity) and its attribute or characteristics 

(USEPA, 1998). For ethaboxam, ecological entities of potential concern include the following: 

birds, amphibians, reptiles, mammals, freshwater fish and invertebrates, estuarine/marine fish 

and invertebrates, terrestrial plants, terrestrial invertebrates, and aquatic vascular and nonvascular plants. The attributes for each of these entities may include growth, survival, and 

reproduction (Table 2.2 in Section 2.6.4).
-Page 13 of 68-

2.5. Conceptual Model

For a pesticide to pose an ecological risk, it must reach ecological receptors in biologically 

significant concentrations. An exposure pathway is the means by which a pesticide moves in the 

environment from a source to an ecological receptor. For an ecological pathway to be complete, 

it must have a source, a release mechanism, an environmental transport mechanism, and a 

feasible route of exposure.

The conceptual model is intended to provide a written description and visual representation of 

anticipated relationships between ethaboxam, potential routes of exposure, and the predicted 

effects for the assessment endpoints. The conceptual model consists of two major components: 

risk hypotheses and a conceptual diagram (USEPA, 1998).

2.5.1. Risk Hypotheses

For ethaboxam, the following generic ecological risk hypothesis is being employed for this 

screening-level risk assessment:

Ethaboxam, when used outdoors in accordance with registered labels, have the potential 

to lead to off-site movement of the compound via run-off and eroded soil leading to 

exposure of nontarget plants and animals. 

Based on information on the environmental fate, mode of action, direct toxicity and 

potential indirect effects, EFED assumes that the proposed uses of ethaboxam have the 

potential to cause reduced survival, growth, and reproduction to non-target terrestrial 

and/ or aquatic animals and plants.

2.5.2. Conceptual Diagram

The conceptual model is a graphical representation of predicted relationships between ecological 

receptors, both listed (threatened and endangered) and non-listed, and the stressors to which they 

may be exposed. A conceptual model specifies potential routes of exposure, biological receptor 

types, and effects endpoints of potential concern. 

Ethaboxam and its degradates are expected to persist in both terrestrial and aquatic environments 

under aerobic and anaerobic conditions, and are considered moderately to slightly mobile, 

lipophilic, and nonvolatile. There is no evidence of degradation via hydrolysis. Ethaboxam has 

not been shown to bioconcentrate in aquatic organisms. 

Ethaboxam is applied to seeds as a seed treatment. Many seeds are incorporated, but given the 

persistence and mobility of ethaboxam, the chemical and/or its major degradates may be 

transported off-site in runoff. Ecologically significant spray drift is not expected for seed 

treatments. Figure 2.1 depicts the stressors, exposure pathways, and potential effects to 
-Page 14 of 68-

terrestrial organisms from proposed uses of ethaboxam. Figure 2.2 depicts the stressors, 

exposure pathways, and potential effects to aquatic organisms from proposed uses of ethaboxam. 

For both figures, dotted lines indicate exposure pathways that are expected to have a low 

likelihood of contributing to ecological risk. 

 

 

Figure 2.1. Conceptual model for ethaboxam seed treatment effects on terrestrial organisms.

Stressor

Source

Receptors

Attribute

Change

Ethaboxam treated seeds applied to use site and degradates

Direct

application

Birds / Terrestrialphase amphibians 

/ reptiles / 

mammals

Seeds

Individual organisms

Reduced survival

Reduced growth

Reduced reproduction

Food chain

Reduction in prey

Habitat integrity

Reduction in primary productivity

Reduced cover

Community change

Terrestrial/riparian plants

grasses/forbs, fruit, terrestrial 

invertebrates 

Runoff

Mammals

Exposure

Media

Soil

Ingestion

Ingestion

Ingestion

Ingestion

Dermal uptake/Ingestion

Root uptake

Wet/dry deposition

Birds / 

Amphibians

Ingestion
-Page 15 of 68-

Figure 2.2. Conceptual model for ethaboxam seed treatment effects on aquatic organisms.

2.6. Analysis Plan

2.6.1. Residues of Concern

Major transformation products resulting from the environmental degradation of ethaboxam are 

LGC-32524, LGC-32525, LGC-32533, LGC-32799, LGC-35525, 2-thiophene carboxylic acid, 

and two unidentified compounds. Ethaboxam represents a novel mode of action and, as a result, 

the toxic moiety is not well understood. However, ECOSAR modeling results indicate that 

LGC-32799 is potentially significantly more toxic than parent ethaboxam. Other degradates are 

estimated to be less toxic. Additonally, no data is available on degradate toxicity. All major 

degradates retain the thiazole group, the thienyl group or both. Given the unknown relative 

toxicity and structural similarity to parent ethaboxam, all major degradates are assumed equally 

toxic as parent ethaboxam for the purposes of environmental modeling, however, the potential 

enhanced toxicity of LGC-32799 will be characterized. 

2.6.2. Preliminary Identification of Data Gaps and Uncertainties

Stressor

Source

Receptors

Attribute

Change

Ethaboxam treated seeds applied to use site and degradates

Fish/aquatic-phase 

amphibians

Eggs 

Larvae 

Juveniles / Adults

Individual organisms

Reduced survival

Reduced growth

Reduced reproduction

Food chain

Reduction in algae

Reduction in prey

Habitat integrity

Reduction in primary productivity

Reduced cover

Community change

Surface water/

Sediment

Runoff

Aquatic Animals

Invertebrates

Vertebrates

Exposure

Media

Uptake/gills 

or integument

Ingestion Ingestion

Wet/dry deposition

Soil Groundwater

Uptake/gills 

or integument

Aquatic Plants

Non-vascular

Vascular

Uptake/cell, 

roots, leaves Riparian plant

terrestrial 

exposure 

pathways see 

Figure 2.1
-Page 16 of 68-

A terrestrial field dissipation study has not been submitted for this new chemical and 

environmental fate data specific to the seed treatment use have not been submitted. Ethaboxam 

major degradates are structurally similar to parent ethaboxam and environmental fate data 

specific to these residues have not been submitted. Unextracted residues in environmental fate 

studies are as high as 70% by study termination. More complete extraction techniques can be 

employed as some unextracted residue may be bioavailable.

There are several notable data gaps and uncertainties in the characterization of ecological effects 

for ethaboxam, including an incomplete dataset for aquatic vascular and non-vascular plants, and 

a complete lack of terrestrial plant data. While potential exposure to ethaboxam from the 

proposed seed treatment uses is expected to be low enough to mitigate some of the concerns 

associated with these data gaps, these data would be necessary to assess risks from any future 

registration requests for an above-ground spray applications of ethaboxam. In the absence of this 

data risks to aquatic and vascular plants will be presumed. 

2.6.3. Evaluation of Multiple Active Ingredients and Mixtures 

The Agency does not routinely include in its risk assessments an evaluation of mixtures of active 

ingredients, either those mixtures of multiple active ingredients in product formulations or those 

in the applicator’s tank. In the case of the product formulations of active ingredients (that is, a 

registered product containing more than one active ingredient), each active ingredient is subject 

to an individual risk assessment for regulatory decision regarding the active ingredient on a 

particular use site. If effects data are available for a formulated product containing more than 

one active ingredient, they may be used qualitatively or quantitatively in accordance with the 

Agency’s Overview Document and the Services’ Evaluation Memorandum (U.S. EPA 2004; 

U.S. FWS/NMFS 2004). However, the proposed end-use product for the new chemical 

ethaboxamis as a single active ingredient formulation. 

2.6.4. Measures of Exposure

Measures of exposure are based on aquatic and terrestrial models that estimate environmental 

concentrations of ethaboxam using labeled application rates and methods. For aquatic exposure 

the Tier II model Pesticide Root Zone Model (PRZM v3.12.2; May 12, 2005) linked with 

EXposure Analysis Modeling System (EXAMS v2.98.4.6; Apr. 25, 2005) via the 

PRZM/EXAMS model shell (PE v5.0, Nov. 15, 2006), i.e., PRZM/EXAMS) was used to 

estimate screening-level exposure concentrations in aquatic environments. The measure of 

exposure for aquatic species in surface water bodies receiving runoff and/or spray drift is a return 

frequency of 1-in-10 years of the estimated environmental concentrations (EEC), based on 30-

year simulations. The maximum 1-in-10 year return frequency concentration is used for 

estimating acute exposures to aquatic organisms (plants and animals); the 1-in-10 year 21-day 

mean concentration is used for assessing aquatic invertebrate chronic exposure; and the 1-in-10 

year 60-day mean concentration is used for assessing chronic exposure for fish (and aquaticphase amphibians for which fish serve as surrogates). Exposure to benthic organisms from 

sediment concentrations in water bodies was assessed; pore-water 1-in-10 year EECs were 

calculated for maximum use patterns. 
-Page 17 of 68-

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

T-REX model (version 1.5.2, 06/11/13). The assumption of the model is that mammals and 

birds may be exposed via their consumption of treated seeds on or immediately adjacent to the 

site of application. 

The Screening Imbibition Program (SIP v.1.0) and Screening Tool for Inhalation Risk (STIR 

v.1.0) were used to calculate upper bound estimates of wildlife exposure via drinking water and 

inhalation, respectively, using ethaboxam solubility or vapor pressure, avian and mammalian 

toxicity endpoints.

2.6.5. Measures of Effect 

Measures of effect are obtained from a suite of registrant-submitted guideline studies that were 

conducted with a limited number of surrogate test species (Table 2.1). No additional ecotoxicity 

data on ethaboxam were located, based on an August 2011 query of the open literature in the 

publically available version of the ECOTOX database (http://cfpub.epa.gov/ecotox/).

The acute measures of effect used in this baseline assessment are the LD50 (median Lethal Dose), 

LC50 (median Lethal Concentration) or EC50 (median Effects Concentration). These are 

measures of acute toxicity which result in 50% of the respective effect in tested organisms. The 

endpoints for chronic measures of exposure are the no observed adverse effect concentration 

(NOAEC) and the no observed adverse effect level (NOAEL). Toxicity studies were submitted 

for freshwater fish and invertebrates, estuarine/marine fish and invertebrates, aquatic plants, 

birds, mammals, bees, and other terrestrial invertebrates. The endpoints used for risk 

characterization are derived from studies which underwent review and were classified as 

“acceptable” (conducted under guideline conditions and considered to be scientifically valid) or 

“supplemental” (conditions deviated from guidelines but the results are considered to be 

scientifically valid). 

Table 2.2 lists the measures of environmental exposure and ecological effects used to assess the 

potential risks of ethaboxam to non-target organisms. The methods used to assess the risk are 

consistent with those outlined in the document “Overview of the Ecological Risk Assessment 

Process in the Office of Pesticide Programs” (USEPA, 2004).
-Page 18 of 68-

Table 2.2. Measures of Exposure and Measures of Effect Used in Assessing Potential Risks 

Associated with the Proposed Uses of Ethaboxam.

Assessment Endpoint Surrogate Species and Measures of 

Ecological Effect1 Measures of Exposure

Birds2

Survival

Lowest acute LD50 (single oral dose 

test) and LC50 (subacute dietary test)

Upper-bound residues on 

food items (i.e., seed)

Reproduction 

and Growth

Lowest NOAEC

(21-week reproduction test)

Mammals

Survival

Lowest acute LD50 (single oral dose 

test)

Reproduction 

and Growth

Lowest NOAEC 

(2-generation reproduction test)

Aquatic Animals (Fish and 

invertebrates)3

Survival Lowest tested LC50 or EC50

(acute toxicity test)

Peak EECs

4

Reproduction 

and Growth

Lowest NOAEC (early life-stage or full 

life-cycle tests)

21-day EECs for invertebrates 

and 60-day EECs for fish4

Terrestrial plants5 Survival and 

growth

Lowest EC25 (for non-listed plants) and 

corresponding NOAEC (for listed 

plants)

(endpoints derived for monocots and 

dicots from seedling emergence and 

vegetative vigor studies)

Estimates of runoff and spray 

drift to non-target areas

Insects6

Survival 

Lowest honeybee LD50 (acute contact 

test)

Lowest Earthworm LC50

Maximum application rate for 

honeybees and estimates of 

soil concentrations for 

earthworms

Aquatic plants (vascular 

and non-vascular)

Survival and 

growth

Lowest EC50 (for non-listed plants) and 

corresponding NOAEC or EC05 (for 

listed plants)

Peak EECs

4

1 The most sensitive species tested within taxonomic groups is used for screening-level risk assessments. 2 Birds represent surrogates for terrestrial-phase amphibians and reptiles. 3 Freshwater fish represent surrogates for aquatic-phase amphibians. 4 Aquatic EECs are based on modeling described in Section 3.2.2.1. 5 Four species of two families of monocots - one is corn, six species of at least four dicot families, of which one is soybeans. 6 Risk to terrestrial invertebrates from ethaboxam use is not evaluated, rather the potential hazard to honey bees and earthworms (i.e. the available 

data) are qualitatively assessed. 

2.6.6. Integration of Exposure and Effects

Exposure and toxicity data are integrated in order to evaluate the risks of adverse ecological 

effects on non-target species. For the screening-level risk assessment of ethaboxam, the

deterministic risk quotient (RQ) method is used to compare estimated exposure concentrations 

with measured toxicity values. The RQ method involves dividing point estimates of 

environmental concentrations by acute and chronic toxicity values. The resulting unitless RQs 

are then compared to the Agency’s Levels of Concern (LOC) (USEPA, 2004) (Table 2.3). 

These criteria are used to indicate when applications of ethaboxam, as directed on the proposed 

labels, have the potential to cause adverse effects to listed and non-listed non-target organisms.
-Page 19 of 68-

Table 2.3. Agency Risk Quotient (RQ) Metrics and Levels of Concern (LOC) Per Risk 

Class.

RISK CLASS RISK DESCRIPTION RQ LOC

Aquatic Animals (fish and invertebrates)

Acute Potential for effects to non-listed animals from acute 

exposures

Peak EEC/LC501 0.5

Acute 

Restricted Use

Potential for effects to animals from acute exposures

Risks may be mitigated through restricted use classification Peak EEC/LC501 0.1

Acute Listed 

Species

Listed species may be potentially affected by acute 

exposures

Peak EEC/LC501 0.05

Chronic Potential for effects to non-listed and listed animals from 

chronic exposures

60-day EEC/NOAEC 

(fish) 1

21-day EEC/NOAEC 

(invertebrates)

Aquatic Plants

Non-Listed Potential for effects to non-listed plants from exposures Peak EEC/LC501 1

Listed Potential for effects to listed plants from exposures Peak EEC/NOAEC 1

Terrestrial Animals (mammals and birds)

Acute Potential for effects to non-listed animals from acute 

exposures

EEC2/LC50 (Dietary) 0.5

EEC/LD50 (Dose)

Acute 

Restricted Use

Potential for effects to animals from acute exposures

Risks may be mitigated through restricted use classification

EEC2/LC50 (Dietary) 0.2

EEC/LD50 (Dose)

Acute Listed 

Species

Listed species may be potentially affected by acute 

exposures

EEC2/LC50 (Dietary) 0.1

EEC/LD50 (Dose)

Chronic Potential for effects to non-listed and listed animals from 

chronic exposures EEC 2

/NOAEC 1

Terrestrial Invertebrates

Acute Porential effects to non-listed and listed terrestrial 

invertebrates EEC3

/LD50 (contact) 0.05

Terrestrial and Semi-Aquatic Plants

Non-Listed Potential for effects to non-target, non-listed plants from 

exposures

EEC/ EC25 1

Listed Plant Potential for effects to non-target, listed plants from 

exposures

EEC/ NOAEC

1

EEC/ EC054

1 LC50 or EC50. 2 Based on upper bound seeding rates. 3 Based on arthropod residues. 

4 Only used when NOAEC value is not available.

3. Analysis

3.1. Use Characterization

Ethaboxam is proposed for use as a flowable suspension used to coat certain crop seeds. 

Proposed maximum application rates and use patterns listed by use according to the proposed 
-Page 20 of 68-

labels are provided in Table 3.1. The presented estimated maximum use rates were calculated 

from the labeled rate, in volume per seed weight, and seeding rates per acre. The registrant

provided use rates in a November 28, 2012 presentation. The calculated use rates are higher than 

those provided by the registrant, therefore, the calculated use rates will be used for the derivation 

of estimated environmental concentrations. The discrepancy between the registrant’s estimated 

maximum rate and the calculated maximum rate is likely due to the maximum weight of seed 

applied per acre, 411 lbs/ac for garden pea in this instance. 

Table 3.1. Proposed Maximum Use Patterns of Ethaboxam.

Crop/Use

Seed 

Application 

Rate 

(fl oz per cwt 

seed)

Seed (lbs/ac)

Maximum 

Application 

Rate

(lbs a.i./A)

Maximum 

Number of 

Applications

Application 

Interval 

(days)

Maximum 

Yearly 

Application

(lbs a.i./A/yr)

Meth 

Appli

Crop Group 6 (Legume vegetables except cowpea and field pea): Lupinus (grain lupin, sweet lupin, white lupin, and white sweet lu 

Phaseolus (field bean, kidney bean, lima bean, navy bean, pinto bean, runner bean, snap bea, tepary bean, and wax bean); Vigna (adzuk 

asparagus bean, blackeyed pea, catjang, Chinese longbean, crowder pea, moth bean, mung bean, rice bean, southern pea, urd bean, and 

yardlong bean); fava bean; chickpea; guar; jackbean; lablab bean; lentil; Pisum (dwarf pea, edible-podded pea, English pea, garden pea 

pea, snowpea, and sugar snap pea); pigeon pea; soybean; sword bean.

Crop Group 15 (Cereal grains except rice and wild rice): Barley; buckwheat; millet; pearl; proso; oats; rye; teosinte; triticale; wheat 

(sweet and field); popcorn, sorghum; grain.

Crop Group 20A (Rapeseed subgroup of oilseed group): Rapeseed, canola varieties only; borage; crambe; cuphea; echium; flax seed 

of pleasure; hare’s ear mustard’ lesquerella; lunaria; meadowfoam; milkweed; mustard seed; oil radish; poppy seed; rapeseed; sesame; 

rocket

Crop Group 6 0.6 411 (garden 

pea) 0.062 NS NS NS Seed tr

Crop Group 15 0.3 156 (wheat) 0.0117 NS NS NS Seed tr

Croup Group 20A 0.3 8.2 (rape) 0.000615 NS NS NS Seed tr

3.2. Exposure Characterization

3.2.1. Environmental Fate and Transport Characterization

The general physical/chemical properties of ethaboxam are summarized in Table 3.2. The 

Agency’s understanding of these properties is limited by the available dataset. Data submitted 

using ethaboxam as the test material is summarized in Appendix A.

Table 3.2 General Physical and Chemical Properties of Ethaboxam

Parameter Value Reference

PC code 090205 --

CAS No. 162650-77-3 --

Structure --
-Page 21 of 68-

Parameter Value Reference

Chemical name 

(IUPAC)

(RS)-N-(α-cyano-2-thenyl)-4-ethyl-2-(ethylamino)-1,3-

thiazole-5-carboxamide --

Chemical name (CAS) N-(cyano-2-thienylmethyl)-4-ethyl-2-(ethylamino)-5 

thiazolecarboxamide --

Common name Ethaboxam (LGC-30473) --

Chemical formula C14 H16N4OS2 --

Molecular weight 320.43 g/mol USEPA 2006b

Water solubility (20oC, 

pH 7)

5.2 mg/L MRID 46378504

Vapor pressure (25oC) 6.1x10-7 mm Hg MRID 46378504

Henry's law constant 4.95x10-8 atm-m3

/mol MRID 46378504

Octanol-water 

partitioning coefficient 

Log KOW (20oC, pH 7)

2.89 MRID 46378504

Dissociation constant 

(pKa)

3.6 MRID 46378504

Melting point (oC) 185 MRID 46378504

Ethaboxam is moderately to slightly mobile in soil (Koc = 404-1,684 mL/g o.c.). The reported 

log octanol/water partition coefficient value (2.89) and fish bioaccumulation factor (4.5-5.1)

suggest that ethaboxam does not readily bioaccumulate. With a vapor pressure of 6.1x10-7 mm 

Hg and a limited solubility, the calculated Henry’s Law Constant for ethaboxam is relativiely 

low (3.8x10-8 atm-m3

/mol). Table 3.2 lists various important physicochemical characteristics of 

the chemicals. A summary of the submitted environmental fate and transport data is provided in 

Table 3.3.

Laboratory studies have indicated that ethaboxam degrades through a combination of biotic and 

abiotic reactions. Under acidic, neutral, and basic conditions, this compound is stable to 

hydrolysis. Ethaboxam is susceptible to aqueous photolysis with a half-life of 4.5 days. 

Ethaboxam is shown to biodegrade in aerobic soils with half-lives ranging from 0.9-9.6 days. 

However, unextracted residues in all aerobic soil metbalism studies ranged from 55% to 70%.

These residues could be bioavailable parent compound considering only one extraction technique 

was used across all current aerobic soil metabolism studies. Ethaboxam is more persistent to 

aerobic aquatic metabolism (t1/2 = 29 to 52 days) and anaerobic soil metabolism (t1/2 = 135 

days). Ethaboxam is considered moderately to slightly mobile in soils based on the FAO soil 

mobility classification (Koc from 404 to 1,684 mL/g). Ethaboxam is not expected to

bioconcentrate in fish (BCF = 4.5-5.1X in whole fish) and it rapidly depurates from fish tissue. 

Table 3.3 Environmental Fate Data Summary for Ethaboxam

Property Value : Parent Only --- Total Toxic Residues Reference 

Hydrolysis half-life: pH 5

 pH 7

 pH 9

stable

stable

stable

MRID 48535660
-Page 22 of 68-

Property Value : Parent Only --- Total Toxic Residues Reference 

Aqueous photolysis half-life 4.5 days --- Stable MRID 48535661

Soil photolysis half-life Stable --- Stable MRID 48535662

Aerobic soil metabolism 

half-life

Sandy loam: 0.9 day (unextracted up to 69%) --- 36 days (DFOP)

Clay loam: 9.6 days (unextracted up to 60%) --- 114 days (IORE)

Loam: 1.9 days (unextracted up to 70%) --- 59 days (DFOP)

4.4 days (unextracted up to 54.8%) --- 126 days (DFOP)

MRID 48535663

MRID 48535664

Anaerobic soil metabolism 

half-life

135 days (DFOP, sandy loam)

Some CO2 formation, unextracted up to 25%

MRID 48535668

Aerobic aquatic metabolism 

half-life

52 days --- 267 days (SFO)

29 days --- 165 days (SFO)

MRID 48535666

Anaerobic aquatic 

metabolism half-life

151 days --- 1,287 days (SFO) MRID 48535667

Adsorption coefficient

Koc (mL/g o.c.)

----------------------------------

Aged Column Leaching 

Study

557 (Sandy loam)

411 (Loamy sand)

404 (Sand) 

1,684 (Loam)

426 (Sandy clay)

(moderately to slightly mobile)

-------------------------------------------------------------------------

Leachate is 1.5-2.7% of applied radioactivity

MRID 48535669

----------------------

MRID 48719401

Terrestrial Field Dissipation 

Study

N/A N/A

Bioconcentration factor 

(BCF)

4.5-5.1

Depuration t1/2 = 1.6-2.4 days

MRID 48535624

3.2.1.1. Transport and Mobility

Ethaboxam is considered moderately to slightly mobile in soil. Soil organic carbon adsorption 

coefficients (Koc) for ethaboxam ranged from approximately 404 to 1,684 mL/g in five soils 

(sandy loam, loamy sand, sand, loam, and sandy clay). The weak mobility along with the 

relatively low vapor pressure (6.1x10-7 mm Hg) and Henry’s law constant (3.8x10-8 atm-m3

/mol), 

indicates that volatilization from water and soil will not be an important transport process.

Data are unavailable for the transport and mobility of degradates. However, those that are 
-Page 23 of 68-

structurally similar to parent ethaboxam are expected to have similar mobility.

 

3.2.1.2. Degradation

Ethaboxam is stable to hydrolysis at pH 5, 7, and 9. Ethaboxam degrades readily to aqueous 

photolysis with a half-life of 4.5 days but is stable to soil photolysis. Ethaboxam also degrades 

readily in aerobic conditions with soil metabolism half-lives ranging from 0.9 to 9.6 days in 

sandy loam, clay loam, and loam soils and aquatic metabolism half-lives ranging from 29 to 52 

days. Degradation occurs less readily in anaerobic conditions as soil metabolism half-life 

estimate is 135 days and the aquatic metabolism half-life estimate is 151 days. 

Ethaboxam maintains much of its chemical structure in many of its degradation products. LGC32533 and LGC-32525 are major degradates formed in abiotic and biotic degradation studies that 

are structurally the same as parent ethaboxam aside for the substitution of the cyanide group for 

an oxide or amide group, respectively. LGC-32799 is another major degradate but is only 

distinguished from parent ethaboxam by a double bond forming to the nitrogen on the bridge 

proximate to the thiophene group. Unidentified degradates exceeded 10% in soil photolysis, 

aqueous photolysis, and aerobic soil metabolism studies and could be structurally similar to 

parent ethaboxam. Major and minor degradates that significantly differ from ethaboxam have 

been identified as well. Only the thiazole and thiophene rings are maintained in the abiotic 

degradation products LGC-32523 and LGC-35525, respectively. Figure 3.4 identifies the major 

degradation products.

Figure 3.4. Identified Major Degradates

Common Name Structure

LGC-32533

LGC-32525
-Page 24 of 68-

LGC-32799

LGC-32523

LGC-35525

3.2.1.3. Field Studies

No field studies have yet been submitted for ethaboxam.

3.2.1.4. Bioconcentration

The reported value of log octanol/ water partition coefficient of 2.89 suggests that ethaboxam 

will likely not bioaccumulate in aquatic organisms. This is corroborated with BCFs for whole 

fish ranging from 4.5-5.1X and a depuriation half-life of 1.6-2.4 days. 

3.2.2. Measures of Aquatic Exposure
-Page 25 of 68-

3.2.2.1. Surface Water Exposure

The Tier II model Pesticide Root Zone Model (PRZM v3.12.2; May 12, 2005; Carousel et al., 

undated) linked with EXposure Analysis Modeling System (EXAMS v2.98.4.6; Apr. 25, 2005; 

Burns, 2004) via the PRZM/EXAMS model shell (PE v5.0, Nov. 15, 2006), i.e., 

PRZM/EXAMS) and the Tier I Rice Model (v1.0, May 8, 2007) were used to estimate screeninglevel exposure concentrations in aquatic environments. The PRZM model simulates pesticide 

movement and transformation on and across the agricultural field resulting from crop 

applications. The EXAMS model simulates pesticide concentrations in water due to loading via 

runoff, erosion, and spray drift, assuming a standard 1-ha pond, 2-m deep (20,000 m3) with no 

outlet that borders a 10-ha treated field. Simulations are for multiple (usually 30) years, from 

which the Agency estimates peak values that are expected to recur on average once every ten 

years, based on time series of daily estimated concentrations. The coupled PRZM and EXAMS 

models and user’s manuals are available from the U.S. Environmental Protection Agency Water 

Models web-page (USEPA, 2011b).

Exposure estimates generated using the standard pond are intended as surrogates for potential 

concentrations in a wide variety of vulnerable water bodies, including prairie potholes, playa 

lakes, vernal pools, other wetlands, man-made and natural ponds, and ephemeral and first-order 

streams. Innumerable site-specific factors will tend to make such water bodies more or less 

vulnerable than the standard pond. Static water bodies that have larger ratios of pesticide-treated 

drainage area to water body volume are generally expected to have higher peak concentrations 

than the standard pond’s EECs. Such water bodies may be smaller in size, and/or have larger 

drainage areas. However such water bodies may be more likely to overflow and discharge 

pesticide in their effluent, whereas the standard pond has no discharge. As watershed size 

increases, it becomes increasingly unlikely that the entire watershed is planted with a single crop 

that is all treated simultaneously with a pesticide. Headwater streams may have peak 

concentrations that are higher than those predicted for the standard pond, but such concentrations 

will likely persist for only short periods of time or distance, as they are carried downstream and 

diluted with water originating elsewhere.

The general chemical and environmental fate data for ethaboxam listed in Table 3.2-3.3 were 

used for generating model input parameters for PRZM and EXAMS (listed in Table 3.5). 

Chemical specific and model input values were chosen in accordance with current divisional 

guidance (USEPA, 2009). Where data was submitted specific to ethaboxam, these data are 

identified below in Table 3.5.

Input parameter degradation half-lives are calculated including total toxic residues (TTR). These 

residues include all non-CO2 extractable residues detected in the suite of degradation studies. 

This TTR approach includes three major degradates that are structurally similar to parent 

ethaboxam but also includes a major degradate and several minor degradates that are less similar 

(i.e., one-ring compounds). Unidentified extractable residues are also included in the 

calculation. The inclusion of all extractable residue is conservative but the toxic moiety 

associated with ethaboxam is unknown and therefore any degradate is potentially toxic.
-Page 26 of 68-

Though unextracted residues are very high in metabolism studies and could potentially be 

bioavailable, these residues are not included in the TTR approach. Unextracted residues in 

submitted aerobic soil metabolism studies were 55% to 70% of applied radioactivity by study 

conclusion when only an acetone extraction was performed. The product registrant has 

performed, but not yet submitted for review, an additional aerobic soil metabolism study using 

acidic and neutral organic solvent extractions that resulted in 31% to 44% applied radioactivity 

as unextracted residue. Though unextracted residue may have decreased significantly, the acidic 

extraction conditions may be more harsh than what might be found in the environment. This 

indicates that unextracted residues may be bound in the soil matrix. Due to this evidence and the 

conservatism associated with including all non-CO2 extractable residue in the TTR approach, 

unextracted residues are not included in the TTR approach.

Table 3.5. PRZM and EXAMS Surface Water Chemical Input Parameters for Ethaboxam.

Parameter (units) Value(s) Sources Comments

Chemical Name Ethaboxam Label Proposed label 

KOC (mL/g o.c.) 696 MRID: 48535669 Represents the average KOC value 

among five values ranging from 404 to 

1,684 ml/g o.c.; the KOC model was 

utilized as adsorption correlates with 

organic carbon content

Aerobic Soil Metabolism 

(days)

119 MRID 48535663

MRID 48535664

Represents the 90th percentile of the 

upper confidence bound on the mean of 

four TTR half-life values: 36, 114, 59, 

and 126

Application Efficiency 

(fraction)

1.0 Seed Treatment

Incorporation depth (cm) 5 “A 2-inch planting depth is ideal for 

average conditions” 

http://www.extension.iastate.edu

/publications/pm1885.pdf

Spray Drift (fraction) 0.0 Seed Treatment

Solubility in Water (ppm) 5.2 MRID 46378504 At 20°C

Aerobic Aquatic 

Metabolism (days)

373 MRID 48535666 Represents the 90th percentile of the 

upper confidence bound on the mean of 

two TTR half-life values: 267 and 165

days

Anaerobic Aquatic

Metabolism (days)

3,861 MRID 48535667 3X the single TTR half-life value

Hydrolysis at pH 7(days) stable MRID 48535660

Aqueous Photolysis @ pH 

7 (days)

stable MRID 48535661

Molecular Weight (g/mole) 320.43 MRID 46378504

Vapor Pressure (torr or 

mmHg)

6.1x10-7 MRID 46378504

Henry’s Law Constant

(atm-m3/mol)

4.95x10-8 MRID 46378504
-Page 27 of 68-

The scenarios selected for modeling purposes in PRZM/EXAMS were used to represent the 

maximum application rates for all ethaboxam uses. Table 3.7 presents the model inputs for 

application type and method as well as the scenarios selected for each modeled use. 

Table 3.7. PRZM/EXAMS Model Input Parameters for Ethaboxam Application Methods

Use Scenario

Seed 

Application 

Rate 

(fl oz per 

cwt seed)

Seed 

(lbs/ac)

Field 

Applicat

ion Rate 

(lbs 

a.i./ac) 

Date of 

Initial 

App.

App. 

Method 

(CAM)1

Cereal grains IAcorn 0.3 156 

(wheat) 0.0117

1 month 

preceding 

emergence

4

Legume vegetables ILbeans 0.6

411 

(garden 

pea)

0.062

1 month 

preceding 

emergence

4

Cereal grains ILcorn 0.3 156 

(wheat) 0.0117

1 month 

preceding 

emergence

4

Cereal grains INcorn 0.3 156 

(wheat) 0.0117

1 month 

preceding 

emergence

4

Cereal grains KScorn 0.3 156 

(wheat) 0.0117

1 month 

preceding 

emergence

4

Cereal grains KSsorghum 0.3 156

(wheat) 0.0117

1 month 

preceding 

emergence

4

Legume vegetables MIbeans 0.6

411 

(garden 

pea)

0.062

1 month 

preceding 

emergence

4

Cereal grains MNcorn 0.3 156 

(wheat) 0.0117

1 month 

preceding 

emergence

4

Cereal grains MScorn 0.3 156 

(wheat) 0.0117

1 month 

preceding 

emergence

4

Legume vegetables MSsoybean 0.6

411 

(garden 

pea)

0.062

1 month 

preceding 

emergence

4

Cereal grains NCcorn 0.3 156 

(wheat) 0.0117

1 month 

preceding 

emergence

4

Rapeseed NDcanola 0.3 8.2 (rape) 0.000615

1 month 

preceding 

emergence

4

Cereal grains NDwheat 0.3 156 

(wheat) 0.0117

1 month 

preceding 

emergence

4

Cereal grains NEcorn 0.3 156 

(wheat) 0.0117

1 month 

preceding 

emergence

4

Cereal grains OHcorn 0.3 156 

(wheat) 0.0117

1 month 

preceding 

emergence

4

Legume vegetables ORsnapbeans 0.6 411 

(garden 0.062 1 month preceding 4
-Page 28 of 68-

pea) emergence

Cereal grains PAcorn 0.3 156 

(wheat) 0.0117

1 month 

preceding 

emergence

4

1 – A Chemical Application Method (CAM) of 4 indicates the chemical is incorporated

The aquatic EECs resulting from the proposed ethaboxam uses (listed in Table 3.9) were used 

for risk estimation in this screening-level assessment. Example model input and output 

supporting these values is provided in Appendix B.

Table 3.9. Modeled Aquatic Surface Water 1-in-10-year EECs for Proposed Uses of 

Ethaboxam

Uses Max. App. Rate

(lbs a.i./A) Peak (ppb) 21-day (ppb) 60-day (ppb)

Cereal grains (MS Corn) 0.0117 0.136 0.099 0.088

Legume vegetables (MS 

Soybean) 0.062 0.538 0.438 0.333

Rapeseed (ND Canola) 0.000615 0.003 0.003 0.003

Table 3.10. Modeled Aquatic Sediment Pore Water 1-in-10-year EECs for Proposed Uses 

of Ethaboxam

Uses Max. App. Rate

(lbs a.i./A) Peak (ppb) 21-day (ppb) 60-day (ppb)

Cereal grains (MS Corn) 0.0117 0.044 0.044 0.044

Legume vegetables (MS 

Soybean) 0.062 0.063 0.063 0.061

Rapeseed (ND Canola) 0.000615 0.002 0.002 0.002

3.2.3. Measures of Terrestrial Exposure

3.2.3.1. Terrestrial Wildlife

Terrestrial wildlife exposure estimates are typically calculated for birds and mammals, 

emphasizing a dietary exposure route for uptake of the pesticide active ingredient. Birds are 

considered surrogates for terrestrial-phase amphibians as well as reptiles. For exposure to 

terrestrial organisms from seed treatments, estimation of pesticide residues in or on seeds as food 

items assumes organisms are exposed to a single pesticide residue in a given exposure scenario 

and focuses on the possible dietary ingestion of residues. For seed applications, estimation of 

loadings of ethaboxam per unit area is calculated based on known or estimated seeding rates. 

This approach, which intends to represent exposures via multiple routes and not just direct 

ingestion, considers observed acute effects (acute oral LD50) in terrestrial toxicology studies and 

relates them to the surface area where the pesticide is applied (LD50/ft2). 

T-REX is used to calculate dose-based EECs of ethaboxam for mammals and birds consuming 

treated seeds. Seeding rates as well as maximum ethaboxam application rates according to the 

proposed label for the major uses of ethaboxam are provided in Table 3.11. Other seed 
-Page 29 of 68-

treatment use patterns are an order of magnitude below on a per acre basis. Estimated avian and 

mammalian doses of ethaboxam as determined using T-REX are also provided in the table for 

small (20 g birds and 15 g mammals), medium (100 g brids and 35 g mammals), and large (1000 

g birds and mammals) animals.

Table 3.11. Ethaboxam application rates and corresponding avian and mammalian doses 

as determined using maximum proposed treatment rates and T-REX.

Animal 

Size Crop

Ethaboxam 

application 

rate 

(lbs. a.i./A)

Maximum 

Seed 

Application 

Rate (mg 

ai/kg seed)

Avian 

Dose (mg 

ai/kgbw/day)

Mammalia

n Dose (mg 

ai/kgbw/day)

Availabl

e AI (mg 

ai /ft2)

Small

Pea, garden 0.05 133.54

33.80 28.29

Medium 19.27 19.55 0.57

Large 8.63 4.53

Small

Wheat, all 0.01 57.87

14.62 12.26

Medium 8.35 8.47 0.09

Large 3.74 1.96

Small

Canola 0.0062 66.77

16.90 14.15

Medium 9.64 9.78 0.02

Large 4.31 2.27

T-REX is also used to calculate EECs for terrestrial invertebrates, using the honey bee (Apis 

mellifera) as a surrogate species, exposed to ethaboxam. However, this method of calculation is 

only applicable to foliar uses that may result in contact exposure to terrestrial invertebrates. In 

addition, data from the registrant suggests that ethaboxam is not a systemic fungicide, suggesting 

that residues of the chemical are unlikely to be found in the plant where they may be consumed 

by terrestrial invertebrates, i.e., the honey bee (MRID 48535704).Therefore, ethaboxam

exposures to terrestrial invertebrates are not quantitatively calculated for derivation of

deterministic RQs. However, potential risks to this taxon are assessed qualitatively in the Risk 

Description, Section 4.2.

3.2.3.2. Terrestrial Plants

Exposure of naturally-occurring terrestrial and semi-aquatic (wetland) plant species is typically 

estimated using OPP’s TerrPlant (v1.2.2; USEPA, 2006b) model and is assumed to encompass 

areas outside the immediate use site. The TerrPlant model is used to derive EECs in runoff and 

drift for terrestrial and semi-aquatic plants near areas where ethaboxam has been applied. 

Runoff exposure is assessed in two scenarios: sheet and channel runoff. In the sheet runoff 

scenario, the treated area generating runoff is assumed to drain into an area with equal size 

containing seedlings, resulting in 1, 2, or 5% of the amount applied being deposited. In the 

channel runoff scenario, a ten-to-one ratio of treatment area to receiving area results in 10, 20, or 

50% of the amount applied being deposited on soil with emerging or emerged seedlings. Spray 
-Page 30 of 68-

drift is also a source of pesticide loading to non-target areas. There is an assumption that no 

spray drift is associated with seed treatment. Data on the toxicity of ethaboxam to terrestrial 

plants have not been submitted to the agency. Potential for risks to terrestrial plants will be 

dicussed in the Risk Description, Section 4.2.

3.3. Ecological Effects Characterization 

In screening-level ecological risk assessments, effects characterization describes the types of 

effects a pesticide can have on aquatic and terrestrial organisms. To date, toxicity tests for 

amphibian or reptiles are not required; birds are used as surrogates for reptiles and terrestrialphase amphibians and freshwater fish are used as surrogates for aquatic-phase amphibians. This 

characterization is based on the registrant-submitted toxicity data for birds, mammals, fish, and 

invertebrates for ethaboxam. Additional data were available in the IUPAC FootPrint database 

and are incorporated in the effects characterization where appropriate. 

In addition to the data submitted in support of registration, the public version of ECOTOX 

(ECOTOXicity) database (USEPA, 2011) was searched for additional toxicity data from the 

open literature. The ECOTOX database is a publicly-available, quality-assured, comprehensive 

tool for locating toxicity data from the open literature and is maintained by EPA Mid-Continent

Ecology Division. More information on ECOTOX can be found at: http://www.epa.gov/ecotox. 

Research papers are thoroughly screened using standard procedures before being accepted into 

ECOTOX thereby ensuring consistent, high quality information. For ethaboxam and its 

degradates, no studies were identified in ECOTOX as of February 26, 2013.

Given that ethaboxam is a new active ingredient with no previous registration in the U.S., it is 

assumed that no ecological incidents exist for ethaboxam.

3.3.1. Aquatic Toxicity Assessment

The most sensitive acute and chronic effects measurement endpoints available for ethaboxam 

exposure to freshwater and estuarine/marine species are summarized in Table 3.13. All 

acceptable and supplemental studies available for the registration of ethaboxam are described 

below

3.13. Summary of most sensitive endpoints from submitted aquatic toxicity studies for ethaboxam. 

Exposure 

Scenario Species Exposure Duration

Toxicity Reference 

Value Effects

Test 

Substance

Reference Toxicity 

Category

Freshwater Fish

Acute Rainbow trout

(Oncorhynchus 

mykiss)

96 hours LC50 = 2.18 mg a.i./L Mortality TGAI MRID 

48535614

Acceptable

Moderately

Toxic

Chronic Fathead minnow

(Pimephales 

30 days NOAEC = 0.88 mg a.i./L

LOAEC = 2.8 mg ai/L

Cumulative 

mortality and 

clinical signs 

TGAI MRID 

48535622

Acceptable

NA
-Page 31 of 68-

3.13. Summary of most sensitive endpoints from submitted aquatic toxicity studies for ethaboxam. 

Exposure 

Scenario Species Exposure Duration

Toxicity Reference 

Value Effects

Test 

Substance

Reference Toxicity 

Category

promelas) of toxicity

Freshwater Invertebrates

Acute Daphnid

(Daphnia magna)

48 hours EC50 = 0.37 mg a.i./L Mortality TGAI MRID 

48535616

Acceptable

Highly 

Toxic

Chronic Daphnid

(Daphnia magna) 21 days NOAEC = 0.05 mg a.i./L

LOAEC = 0.1 mg a.i./L

Time to first 

brood release, 

total offspring 

produced, and 

total offspring 

produced per 

reproductive 

day

TGAI MRID 

48535620

Acceptable

NA

Benthic Organisms

Chronic

Midge

(Chironomus 

riparius)

28 days

NOAEC = 0.030 mg 

TRR/L

LOAEC = 0.063 mg 

TRR/L

Mortality and 

Growth

TGAI MRID 

48793901

Supplemental

(for qualitative 

use)

NA

Estuarine/Marine Fish

Acute

Sheepshead 

minnow

(Cyprinidon 

variegates)

96 hours LC50 > 3.1 mg a.i./L Mortality

TGAI MRID 

48535617

Supplemental

(for 

quantitative 

use)

Moderately

Toxic

Chronic Sheepshead 

minnow

(Cyprinidon 

variegates)

34 days NOAEC = 0.17 mg a.i./L

LOAEC = 0.42 mg a.i./L

Length and 

wet and dry 

weight

TGAI

MRID 

48535623

Acceptable

NA

Estuarine/Marine Invertebrates

Acute Eastern Oyster

(Crassostrea 

virginica)

96 hours EC50 = 0.37 mg a.i/L Growth TGAI MRID 

48535618

Acceptable

Highly 

Toxic

Acute Mysid shrimp

(Mysidopsis bahia)

96 hours LC50 = 0.50 mg a.i./L Mortality TGAI MRID 

48535619

Acceptable

Highly 

Toxic

Chronic An acceptable estuarine/marine chronic toxicity study is not available; therefore, an acute-to-chronic ratio (ACR) from the 

daphnid will be applied to the most sensitive acute estuarine/marine endpoint for the eastern oyster. The resulting value of 0.05 

mg a.i./L will be used in risk estimation. 0.37 mg a.i./L (acute daphnid endpoint) ÷ 0.05 mg a.i./L (chronic daphnid endpoint) = 

0.37 mg a.i./L (acute eastern oyster endpoint) ÷ X (chronic value of interest) . X = 0.05 mg a.i./L

Aquatic Plants
-Page 32 of 68-

3.13. Summary of most sensitive endpoints from submitted aquatic toxicity studies for ethaboxam. 

Exposure 

Scenario Species Exposure Duration

Toxicity Reference 

Value Effects

Test 

Substance

Reference Toxicity 

Category

Acute Lemna gibba -- -- -- -- --

Acute Pseudokirchneriell

a subcapitata

96 hours NOAEC = 1.8 mg a.i./L

EC50 > 3.6 mg a.i./L

Cell density TGAI MRID

48535630

Acceptable

Toxicity 

categories 

are not 

specified for 

plants

3.3.1.1 Toxicity to Freshwater Fish

In a 96-h acute toxicity study (MRID 48535614; Acceptable), rainbow trout (Oncorhynchus 

mykiss) were exposed to ethaboxam at mean measured concentrations of <0.007 (<LOD, 

negative and solvent control), 0.072, 0.14, 0.28, 0.59, 1.2, 2.4 and 4.8 mg /L. The 96-h LC50 was 

2.18 mg/L. There were no mortalities in the controls and 0.14 and 0.28 mg/L treatment groups. 

No sub-lethal effects were observed in the controls and mean-measured 0.072 and 0.14 mg ai/L 

treatment groups; however, sublethal effects (e.g., lethargy, loss of equilibrium, hyperventilation, 

increased pigmentation, exophthalmia, irregular swimming) were observed in the 0.28-4.8 mg 

ai/L treatment groups. The NOAEC values based on sub-lethal effects was 0.14 mg/L. Based on 

these results, ethaboxam can be categorized as moderately toxic to rainbow trout on an acute 

basis. 

In a second 96-h acute toxicity study (MRID 48535615; Acceptable), fathead minnows 

(Pimephales promelas) were exposed to ethaboxam at a mean measured concentration of 4.6 mg 

ai/L (the limit of solubitlity under study conditions). The 96-h LC50 was >4.6 mg ai/L. No sublethal effects (e.g., lethargy, loss of equilibrium, on the bottom of the test vessel) were observed 

in the controls and mean-measured 4.6 mg ai/L treatment groups. Based on the results of this 

study, ethaboxam would be classified as nontoxic to Pimephales promelas at the limit of its 

solubility. Based on these results, ethaboxam can be categorized as moderately toxic to fathead 

minnows on an acute basis.

Additional data are available in the Footprint database for bluefill sunfish (Lepomis macrochirus) 

exposed to ethaboxam in a 96-hour toxicity study. The resulting LC50 was 0.102 mg a.i./L, 

which indicate that ethaboxam is highly toxic to bluegill. These data should be submitted to the 

Agency for review.

The 33-day chronic toxicity of ethaboxam to the early life-stage of fathead minnow (Pimephales 

promelas) was studied under flow-through conditions (MRID 48535622; Acceptable). Fertilized 

eggs/embryos (60/level, <48 hours old) were exposed to ethaboxam at mean-measured 

concentrations of <0.004 (<LOD, solvent control), 0.027, 0.089, 0.27, 0.88, and 2.8 mg ai/L. 

The LC50 for post-hatch survival was 1.5 mg ai/L. The 33-day NOAEC and LOAEC values 

were 0.88 and 2.8 mg ai/L, respectively, based on a treatment-related increase in mortality 

accompanied by clinical signs of toxicity at the 2.8 mg ai/L level. Treatment-related clinical 

signs of toxicity were observed at the 2.8 mg ai/L level and included curvature of the spine, 
-Page 33 of 68-

inactivity, loss of equilibrium, and moribund condition. There were no treatment-related effects 

on either length or dry weight of surviving fry at 28-days post-hatch. 

3.3.1.2. Toxicity to Freshwater Invertebrates

In a 48-hour acute toxicity study (MRID 48535616; Acceptable), daphnids (Daphnia magna) 

under static conditions were exposed to ethaboxam at mean-measured concentrations of <0.007 

(<LOD, negative and solvent controls), 0.073, 0.14, 0.28, 0.53, 1.1 and 2.1 mg ai/L. 

Immobilization was 0% in the controls and 0.073 and 0.14 mg ai/L treatment groups and was 5% 

in the 0.28 mg ai/L treatment group and 100% in the 0.53-2.1 mg ai/L treatment groups. The 48-

hour EC50 and NOAEC values were 0.37 and 0.28 mg ai/L, respectively. Based on the results of 

this study, ethaboxam would be classified as highly toxic to Daphnia magna.

The 21-day-chronic toxicity of ethaboxam to Daphnia magna was studied under static-renewal 

conditions (MRID 48535620; Acceptable). Daphnids were exposed at mean-measured 

concentrations of <0.0010 (<LOD, controls), 0.0062, 0.013, 0.025, 0.050, and 0.10 mg ai/L. The 

21-day LC50 for adult survival was >0.10 mg ai/L. The 21-day EC50 for reproduction (offspring 

production per daphnia) was 0.083 mg ai/L. The NOAEC and LOAEC were 0.050 and 0.10 mg 

ai/L, respectively, based upon a treatment-related reduction in offspring production accompanied 

by a delay in the time to first brood release at the 0.10 mg ai/L level. Survival remained at 100% 

for all levels throughout the study and there were no treatment-related effects on growth of adults 

(total length and dry weight) at any concentration level.

In a 28-day chronic toxicity study (MRID 48793901; Supplemental for qualitative use), midges 

(Chironomus riparius) were exposed to ethaboxam under static conditions at nominal

concentrations of 0, 0.019, 0.038, 0.075, 0.15, and 0.30 mg total radioactive residues (TRR)/L. 

The NOAEC and LOAEC based on the time-weighted average concentration was 0.030 and 

0.063 mg TRR/L, respectively, based on developmental rate. These data may be used 

qualitatively only because the study was designed to represent a single exposure from spray drift 

(spiked water) and does not address exposure from run-off or multiple exposure events. In 

addition, the study does not report effects on reproductive endpoints, which may be more 

sensitive to ethaboxam. 

3.3.1.3. Toxicity to Estuarine/Marine Fish

In a 96-h acute toxicity study (MRID 48535617; Supplemental), sheepshead minnows 

(Cyprindon variegatus) were exposed to ethaboxam at a mean measured concentration of 3.1 mg 

ai/L. This study was classified as supplemental because it was not clear whether the 

concentration tested represented the limit of solubility for ethaboxam under test conditions. The 

96-h LC50 was >3.1 mg ai/L. There no mortalities in the controls and 3.1 mg ai/L treatment 

group. No sub-lethal effects (e.g., lethargy, loss of equilibrium, on the bottom of the test vessel) 

were observed in the controls and mean-measured 3.1 mg ai/L treatment groups. Based on the 
-Page 34 of 68-

results of this study, ethaboxam would be classified as moderately toxic to Cyprindon variegatus

on an acute exposure basis. 

The 34-day chronic toxicity of ethaboxam to the early life-stage of sheepshead minnow 

(Cyprinodon variegatus) was studied under flow-through conditions (MRID 48535623; 

Acceptable). Fertilized sheepshead minnow embryos (80/level, <24 hours old) were exposed at 

mean-measured concentrations of <0.0300 (<LOQ, controls), 0.067, 0.17, 0.42, 1.0, and 2.1 mg 

ai/L, respectively. The overall NOAEC and LOAEC were 0.17 and 0.42 mg ai/L, respectively, 

based on treatment-related reductions in length and wet and dry weight of surviving fry (most 

sensitive endpoints). 

Mean hatching success was 98 and 100% for the negative and solvent control levels, 

respectively, and 95, 95, 98, 95, and 46% for the mean-measured 0.067, 0.17, 0.42, 1.0, and 2.1 

mg ai/L treatment levels, respectively. The difference was statistically-significant (p≤0.05) 

compared to the negative control at the 2.1 mg ai/L treatment level. Post-hatch larval survival 

averaged 99 and 98% for the negative and solvent control levels, respectively, and 97, 100, 100, 

89, and 0% for the mean-measured 0.067, 0.17, 0.42, 1.0, and 2.1 mg ai/L treatment levels, 

respectively. A statistically-significant (p≤0.05) difference compared to the negative control was 

detected at the 2.1 mg ai/L treatment level. 

No treatment-related effect on the time to hatch was observed. Embryos began hatching on Day 

5 of the test and all surviving embryos from all levels had hatched by Days 6 to 9. All fish from 

the 1.0 mg ai/L level appeared weak on day 0 post-hatch, and approximately 26% of the fish 

from this level exhibited signs of toxicity, including small size, weakness, lethargy, lying at the 

bottom of the chamber, swimming erratically, surfacing, fin pecked, or loss of equilibrium by the 

end of the test. All fish from the 2.1 mg ai/L level were dead by day 6 post-hatch. 

Statistically-significant reductions in length were observed at the 0.42 mg ai/L level compared to 

the negative control (p≤0.05). Total lengths averaged 20.5 to 21.2 mm for the negative control 

though 0.17 mg ai/L levels, 20.1 mm at the 0.42 mg ai/L level, and 19.4 mm at the 1.0 mg ai/L 

level. Statistically-significant reductions in wet and dry weights compared to the negative control 

were observed at all treatment levels. Wet weights averaged 104.2 to 113.0 mg for the negative 

control though 0.17 mg ai/L levels, 98.3 mg at the 0.42 mg ai/L level, and 88.1 mg at the 1.0 mg 

ai/L level; and dry weights averaged 24.3 to 26.7 mg for the negative control through 0.17 mg 

ai/L levels, 23.6 mg at the 0.42 mg ai/L level, and 21.8 mg at the 1.0 mg ai/L level. 

3.3.1.4. Toxicity to Estuarine/Marine Invertebrates

In a 96-h acute toxicity test (MRID 48535618; Acceptable), Eastern oysters (Crassostrea 

virginica) were exposed to ethaboxam at mean-measured concentrations of <LOQ, (<0.0100 mg 

ai/L, controls), 0.027, 0.068, 0.17, 0.42, 1.1 and 2.6 mg ai/L. The EC50 for shell deposition was 

0.37 mg a.i./L. Based on these data ethaboxam would be classified as highly toxic to the Eastern 

oyster on an acute exposure basis. 
-Page 35 of 68-

In an addition 96-h acute toxicity study (MRID 48535619; Acceptable), mysid shrimp 

(Mysidopsis bahia) were exposed to ethaboxam at nominal concentrations of 0 (negative 

control), 0 (solvent control), 0.063, 0.13, 0.25, 0.50 and 1.0 mg ai/L. The LC50 was 0.50 mg 

a.i./L. based on these data ethaboxam would be classified as highly toxic to the mysid shrimp on 

an acute exposure basis. 

In 32-day invertebrate life-cycle study (MRID 48535621; Invalid), mysid shrimp were exposed 

to ethaboxam at mean-measured concentrations of <0.300 (<LOQ, controls), 0.42, 0.97, 2.1, 4.3, 

and 9.6 μg ai/L. This study was classified as invalid because of poor reproductive performance 

by females in all treatment and control groups, suggesting potentially compromised lab cultures. 

Because an acceptable estuarine/marine chronic toxicity study is not available, an acute-tochronic ratio (ACR) from the daphnid of 7.4 will be applied to the most sensitive acute 

estuarine/marine endpoint for the eastern oyster (0.37 mg a.i./L (acute daphnid endpoint) ÷ 0.05 

mg a.i./L (chronic daphnid endpoint)). The resulting value of 0.05 mg a.i./L will be used in risk 

estimation.

3.3.1.5. Toxicity to Aquatic Plants

In a 96-hour acute toxicity study (MRID 48535630; Acceptable), cultures of freshwater green 

algae, Pseudokirchneriella subcapitata strain CCAP 278/4, were exposed to ethaboxam at meanmeasured concentrations of 0.007 (<LOD, negative and solvent controls), 0.23, 0.47, 0.96, 1.8, 

and 3.6 mg/L. The NOAEC and EC50/IC50 values based on cell density, growth rate, and area 

under the curve were 1.8and >3.6 mg a.i./L, respectively. The % growth inhibition of cell density 

in the treated algal culture as compared to the negative control ranged from 7 to 25%. 

Additional data are available on the Footprint database for Raphidocelis subcapitata, another 

freshwater algal species, exposed to ethaboxam for 72 hours. While a NOAEC value is not 

provided, the EC50 value based on growth is 0.009 mg a.i./L, which indicate that R. subcapitata

is considerably more sensitive to ethaboxam than P. subcapitata. 

3.3.2 Terrestrial Effects Characterization

The most sensitive acute and chronic toxicity reference values available for ethaboxam exposure 

to mammals, birds, and terrestrial invertebrates are summarized in Table 3.14. Terrestrial plant 

data has not been submitted for ethaboxam. All acceptable and supplemental studies available for 

the registration of ethaboxam are described below.

Table 3.14 Summary of most sensitive endpoints from submitted terrestrial toxicity studies 

for ethaboxam. 

Species 

(common 

name)

Taxa 

Represented Endpoint Effect

Test 

Substance 

(% a.i.)

Reference/ 

Classification

Acute 

Toxicity 

Classification
-Page 36 of 68-

Table 3.14 Summary of most sensitive endpoints from submitted terrestrial toxicity studies 

for ethaboxam. 

Species 

(common 

name)

Taxa 

Represented Endpoint Effect

Test 

Substance 

(% a.i.)

Reference/ 

Classification

Acute 

Toxicity 

Classification

Rattus 

norvegicus

(Laboratory 

Rat)

Mammals

Acute Oral LD50 > 

5000 mg a.i./kg-bw No toxicity TGAI

MRID# 

46378518

Acceptable

Practically 

non-toxic

NOAEL = 16.2 mg 

a..i/kg/day

Testicular 

lesions and 

reduced 

fertility in 

F1 males 

and 

decreased 

body 

weight in 

F1 pups 

and 

decreased 

viability of 

F1 and F2 

males 

during 

lactation.

TGAI

MRID# 

46387804

Acceptable

NA

LOAEL = 52.6 mg 

a.i./kg/day

Bobwhite 

quail (Colinus 

virginianus)

Birds, 

terrestrialphase 

amphibians, 

and reptiles

LD50 >2000 mg 

a.i./kg bw No toxicity TGAI

MRID# 

48535607

Acceptable

Practically 

non-toxic

Zebra finch 

(Taeniopygia 

guttata)

LD50 > 2000 mg 

a.i./kg-bw No toxicity TGAI

MRID 

48535608

Supplemetnal

Practically 

non-toxic

Bobwhite 

quail (Colinus 

virginianus)

LC50 > 5080 mg 

a.i./kg diet No toxicity TGAI

MRID# 

48535609

Acceptable

Practically 

non-toxic

Bobwhite 

quail (Colinus 

virginianus)

NOAEC = 170 mg 

a.i./kg-diet

eggs laid, 

eggs set, 

ratio of 

eggs set to 

eggs laid, 

viable 

embryos, 

live 

embryos, 

number 

hatched, 

and 

hatchling 

survivors

TGAI

MRID# 

48535613

Acceptable

Not 

Applicable LOAEC = 415 mg 

a.i./kg-diet

Honey bee

(Apis 

mellifera)

Terrestrial 

invertebrates

Contact LD50 > 

111.8 μg a.i./bee No toxicity TGAI

MRID# 

48535627

Acceptable

Practically 

non-toxic
-Page 37 of 68-

Table 3.14 Summary of most sensitive endpoints from submitted terrestrial toxicity studies 

for ethaboxam. 

Species 

(common 

name)

Taxa 

Represented Endpoint Effect

Test 

Substance 

(% a.i.)

Reference/ 

Classification

Acute 

Toxicity 

Classification

Oral

LD50 > 111.8μg 

a.i./bee No toxicity TGAI Practically 

non-toxic

Contact LD50 = 51

μg a.i./bee Mortality TGAI Footprint1 Toxic

1 Data have not been submitted to the Agency for review. 

3.3.2.1. Toxicity to Mammals

Mammalian toxicity data submitted to the Agency’s Health Effects Division (HED) are used to 

approximate toxicity to wild mammals. These studies are typically conducted with laboratory 

rats (Rattus norvegicus) or mice (Mus musculus). No studies evaluating toxicity to wild mammal 

species are available, or have been submitted to the Agency for ethaboxam. 

The reported laboratory rat acute oral LD50 value is greater than 5000 mg/kg-bw (MRID 

46378518). Based on the reported non-definitive laboratory rat oral LD50 value, ethaboxam may 

be classified as “practically non-toxic” to small mammals.

In the available 3-generation rat reproduction study, the NOAEL is 16.2 mg a.i./kg/day based on 

testicular lesions, reduced fertility in F1 males, decreased body weight in F1 pups, decreased 

viability of F1 and F2 males during lactation, decreased F1 pup body weight and body weight 

gain (MRID 46387804). 

3.3.2.2. Toxicity to Birds

The acute oral toxicity of ethaboxam to ca. 10-month old Northern bobwhite quail (Colinus 

virginianus) was assessed over 14 days (MRID 48535607; Acceptable). Ethabocam technical

was administered to the birds by oral gavage at nominal levels of 0 (vehicle control), 500, 1000, 

and 2000 mg a.i./kg bw. The 14-day acute oral LD50 was >2000 mg a.i./kg bw. The NOAEL 

value based on weight gain was 1000 mg a.i./kg bw due to reduced body weight gain 

corresponding to a reduction in feed consumption for both male and female birds at the 2000 mg 

a.i./kg bw dosage level. Ethaboxam would be classified as practically non-toxic to young adult 

Northern bobwhite quail (Colinus virginianus) on an acute exposure basis. 

In a second study, the acute oral toxicity of ethaboxam to ca. 5 to 9-month old zebra finch 

(Taeniopygia guttata) was assessed over 14 days (MRID 48535608; Acceptable). Ethaboxam 

technical was administered to the birds by gelatin capsule at nominal levels of 0 (control) and 

2000 mg ai/kg bw. The 14-day acute oral LD50 was >2000 mg a.i./kg bw. The NOAEL was 2000 

mg a.i./kg bw based on weight gain and food consumption. Ethaboxam is classified as practically 
-Page 38 of 68-

non-toxic to young adult zebra finch (Taeniopygia guttata). 

In a sub-acute dietary study, the toxicity of ethaboxam to bobwhite quail was assessed over 8 

days (MRID 48535609; Acceptable). No test substance related mortality was observed in the 

control group or any of the treatment groups throughout the 8-day test period. The 8-day acute 

dietary LC50 was >5080 mg ai/kg diet. No clinical signs of toxicity were observed; however, 

reductions in bodyweight gain (Days 0 to 5) and feed consumption (Days 1 to 2) were observed 

in the 5080 mg ai/kg treatment group. Ethaboxam is classified as practically non-toxic to 

juvenile Northern Bobwhite quail (Colinus virginianus).

The one-generation reproductive toxicity of ethaboxam to 20 pairs per level of ca. 10-month old 

Northern bobwhite quail (Colinus virginianus) was assessed over 22 weeks (MRID 48535612; 

Acceptable). Ethaboxam technical was administered to the birds in the diet at mean-measured 

concentrations of <3.75 (LOD, control), 99, 304, and 993 mg ai/kg diet. A total of nine 

mortalities were observed in the control and treatment groups; none were considered related to 

the treatment. No overt signs of toxicity were observed in any of the treatments. There were no 

treatment-related differences in feed consumption or in adult body weight gain and hatchling 

bodyweight at any treatment level. There were no treatment-related differences for offspring 

hatchability or survival parameters. 

In a second study, the one-generation reproductive toxicity of ethaboxam to 16 pairs per level of 

19-week old mallard duck (Anas platyrhynchos) was assessed over 21 weeks (MRID 48535613; 

Acceptable). Ethaboxam was administered to the birds in the diet at mean-measured 

concentrations of <20 (LOQ, control), 170 ± 15.2, 419 ± 28.0, and 1050 ± 95.9 mg ai/kg diet.

There were no treatment-related mortalities, overt signs of toxicity, or treatment-related effects 

upon body weight or feed consumption in the control and treatment groups. No treatment-related 

effects upon any of the reproductive parameters were observed at the 170 mg ai/kg treatment 

group. Treatment-related reductions in egg production were observed in the 419 and 1050 mg 

ai/kg treatment groups, which ultimately led to further, more sensitive reductions in offspring 

hatchability and survival parameters at the same levels. Affected endpoints (p<0.05) included 

eggs laid, eggs set, ratio of eggs set to eggs laid, viable embryos, live embryos, number hatched, 

and hatchling survivors. No treatment-related differences upon eggshell thickness, offspring 

body weights, or other relative reproductive parameters were observed at any treatment level. 

The NOEL for parental toxicity and reproduction endpoints was 170 mg ai/kg diet.

3.3.2.3. Toxicity to Terrestrial Invertebrates

In a 48-h oral toxicity study (MRID 48535627; Acceptable), honey bees (Apis mellifera) were 

exposed to ethaboxam at a mean-measured concentration of 111.8 μg a.i./bee via a sucrose 

solution treated with ethaboxam. No mortality was observed for the untreated control groups. No 

mortality was observed for the 111.8 μg a.i. ethaboxam/bee treatment level or the 0.04 and 0.08 

μg dimethoate/bee treatment levels. No behavioral abnormalities were observed. The 48-hour 

LD50 of Ethaboxam was >111.8 μg a.i./bee. 
-Page 39 of 68-

Also submitted to the Agency was a contact toxicity test, which exposed honey bees to 111.8 μg 

a.i./bee in acetone applied to the ventral thorax (MRID 48535627; Acceptable). No mortality was 

observed for the untreated control groups. Mortality in the acetone/sucrose control groups ranged 

from 3.3 to 8.3% after 48 hours. No mortality was observed for the 111.8 μg a.i. ethaboxam/bee 

treatment level or the 0.04 and 0.08 μg dimethoate/bee treatment levels. Mortality was 10%, 

60%, and 93.3% for the 0.12, 0.16, and 0.32 μg dimethoate/bee treatment levels. No behavioral 

abnormalities were observed. The 48-hour LD50 of Ethaboxam was >100 μg a.i./bee. 

Additional data for the honey bee are available on the Footprint database. Based on observed 

mortaility in the 48-hour contact study, the LD50 was 51 μg a.i./bee, which would indicate that

ethaboxam is, in fact, toxic to honey bees. These data should be submitted to the Agency for 

review.

An additional non-guideline study was submitted describing the toxicity of ethaboxam to 

earthworms (Eisenia fetida) after 14 days of exposure (MRID 48535628; Supplemental). 

Earthworms were exposed to ethaboxam at nominal concentrations of 0 (negative control), 95, 

171, 309, 556, and 1000 mg a.i./kg dryweight (dw) of soil. After 14 days of exposure, there was 

5, 2.5, 5, 2.5, and 0% mortality observed in the 95, 171, 309, 556, and 1000 mg a.i./kg dw soil 

groups, respectively, compared to 0% mortality in the negative control. The LC50 was >1000 mg 

a.i./kg dw of soil. Mean body weights (Days 0-14) were decreased by 9, 8, 15, 10, and 13% in 

the 171, 309, 556, and 1000 mg a.i./kg dw soil groups, respectively, compared to 3% body 

weight loss in the control. The EC50 was >1000 mg a.i./kg dw of soil based on body weight 

losses. The NOAEC, based on significant (p<0.05) body weight losses at the 309 and 1000 mg

a.i./kg soil levels, was 171mg a.i./kg dw of soil. 

3.3.2.4. Toxicity to Terrestrial Plants

Data on the toxicity of ethaboxam to terrestrial plants have not been submitted to the agency. 

Potential risks to this taxa will be discussed in the Risk Description, Section 4.2. 

4. Risk Characterization

4.1. Risk Estimation

Toxicity data and exposure estimates are used to evaluate the potential for adverse ecological 

effects on non-target species. This screening-level assessment for ethaboxam relies on the 

deterministic RQ method to provide a metric of potential risks. The RQ provides a comparison 

of exposure estimates to toxicity endpoints (i.e., the estimated exposure concentrations are 

divided by acute and chronic toxicity values). The resulting unitless RQs are compared to the 

Agency’s LOCs, as shown in Table 2.3. LOCs are used by the Agency to indicate when the use 

of a pesticide, as directed by the label, has the potential to cause adverse effects to non-target 

organisms.

4.1.1. Aquatic Organisms 
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The highest screening-level aquatic EECs based on the maximum application rates for each 

proposed use pattern were used to derive RQs. These exposure estimates represent 

concentrations in surface water (Table 3.9). Peak EECs are used to represent acute exposure to 

fish, aquatic invertebrates, and aquatic plants, and the highest 21-day and 60-day average EECs 

represent chronic exposure to aquatic invertebrates and fish, respectively. These EECs include 

LGC-32799, which occurs at 22.7% of applied radioactivity in the dark control of the soil 

photolysis study, as part of total toxic residues of ethaboxam. However, this residue is 

potentially more toxic than ethaboxam (Appendix D). LCG-32533, LCG-32525, LGC-32523, 

and LGC-35525 were not estimated to be as toxic as ethaboxam but are conservatively included 

as total toxic residues in the absence of data.

4.1.1.1. Fish and Invertebrates

Results of acute toxicity studies in freshwater and estuarine/marine fish (Table 3.13) indicate 

that ethaboxam is “highly toxic” to freshwater and estuarine/marine invertebrates and 

“moderately toxic” to freshwater and estuarine/marine fish on an acute exposure basis. Acute 

and chronic RQs for freshwater and estuarine/marine fish and invertebrates are all less than 0.01, 

well below the Agency’s acute risk to listed species LOC (0.05), acute risk to non-listed species 

LOC (0.5), and chronic listed and non-listed species LOC (1.0) for all of the proposed uses. 

RQs for benthic aquatic invertebrates were not calculated because the available data are for 

qualitative use only. Potential risks to these taxa will be discussed in the Risk Description, 

Section 4.2. 

4.1.1.2. Aquatic Plants

Although ethaboxam does exhibit effects on freshwater green algae, including

Pseudokirchneriella subcapitata and Raphidocelis subcapitata, these effects are at higher 

concentrations than those estimated for the highest proposed ethaboxam seed treatment use. The 

listed species RQ for P. subcapitata is <0.01, while the LOC is 1.0. The non-listed species RQ 

for R. subcapitata is 0.06, which is less than the LOC of 1.0. Data on a vascular aquatic species 

are not available. Uncertainties are discussed in the risk description in Section 4.2. 

4.1.2. Terrestrial Organisms

4.1.2.1. Mammals

Acute RQs were not calculated for mammals because only non-definitive acute oral toxicity data 

are available. Based on the available acute toxicity data, no mortality was observed in any of the 

mammalian studies conducted on ethaboxam technical at the highest concentrations/doses tested; 

as such, ethaboxam is categorized as “practically nontoxic” to mammals on an acute exposure 

basis. Further discussion of the predicted exposure values relative to the levels at which no 

mortality was observed is provided as part of the risk description in Section 4.2.4.
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Based on the proposed maximum application rates, combined with the amount of seed per acre, 

the highest exposures occurred for the legume vegetables (e.g., garden peas), resulting in the 

highest chronic RQs across all uses of 0.79, less than the chronic risk LOC of 1.0. Table 4.2

lists maximum chronic exposure mammal RQs for all of the proposed uses based on the upper 

90th percentile Kenaga values. These RQs all fall below the Agency’s mammalian chronic risk 

to listed and non-listed species chronic risk LOC (1.0). 

Table 4.2. Chronic Mammalian Risk Quotients for Ethaboxam Proposed Use as a 

Seed Treatment

Animal 

Size Crop

Ethaboxam

application 

rate 

(lbs. a.i./A)

Maximum 

Seeding Rate 

(lbs 

seed/acre)

Mammalian Dose 

(mg ai/kg-bw/day) Mammalian RQs

15g

Pea, 

garden 0.05 133.54

28.29 0.79

35g 19.55 0.68

1000g 4.53 0.36

15g

Wheat 0.01 57.87

12.26 0.34

35g 8.47 0.29

1000g 1.96 0.16

15g

Canola 0.0062 66.77

14.15 0.40

35g 9.78 0.34

1000g 2.27 0.18

4.1.2.2. Birds

Acute RQs were not calculated for birds because only non-definitive acute and sub-acute toxicity 

endpoints are available. Ethaboxam is categorized as “practically non-toxic” to zebra-finch,

bobwhite quail, and mallard duck on an acute and subacute oral and dietary basis. Treatmentrelated sublethal effects were observed in mallard duck and bobwhite quail studies at the highest 

concentrations tested; however these concentrations were above the typical limit dose for avian 

acute and sub-acute dietary toxicity studies. These effects (noted previously) will be discussed 

further, relative to potential exposure, in the Risk Description section, but acute risk to avian 

species is expected to be low. 

Based on the proposed maximum application rates, combined with the amount of seed per acre, 

the highest exposures occurred for the legume vegetables (e.g., garden peas), resulting in the 

highest chronic RQs across all uses of 0.79, which is below the chronic risk LOC of 1.0. Table 

4.2 lists maximum chronic exposure RQs for all of the proposed uses based on the upper 90th

percentile Kenaga values. 
-Page 42 of 68-

Table 4.2. Chronic Avian Risk Quotients for Ethaboxam Proposed Use as a Seed 

Treatment

Animal 

Size Crop

Ethaboxam

application 

rate 

(lbs. a.i./A)

Maximum 

Seeding Rate 

(lbs 

seed/acre)

Avian Dose (mg 

ai/kg-bw/day) Avian RQs1

20g

Pea, 

garden 0.05 133.54

33.80

100g 19.27 0.79

1000g 8.63

20g

Wheat 0.01 57.87

14.65

100g 8.35 0.34

1000g 3.74

20g

Canola 0.0062 66.77

16.90

100g 9.64 0.39

1000g 4.31

1 Chronic RQs are not adjusted for weigth class for birds as no data exits for incorporating scaling factors. 

4.1.2.3. Terrestrial Invertebrates 

RQs were not calculated for flying terrestrial invertebrates because use of ethaboxam as a seed 

treatment is not likely to result in contact exposure to non-soil dwelling terrestrial invertebrates, 

such as the surrogate species the honey bee and data from the registrant indicate that ethaboxam 

is not a systemic fungicide and would therefore not be found in parts of the plants where they 

may be consumed by terrestrial invertebrates (MRID 48535704). Based on this information, 

exposure to flying terrestrial invertebrates is unlikely from the proposed seed treatment use.

4.1.2.4. Non-target Terrestrial Plants

Potential effects to riparian and upland vegetation are assessed deriving RQs from terrestrial 

plant seedling emergence and vegetative vigor EC25 and NOEAC endpoints. However, these 

data are not currently available. Characterization of exposure and potential toxicity will be 

discussed in the Risk Description section. 

4.2. Risk Description

The results of risk estimation indicate that proposed uses of thaboxam are not likely to adversely 

affect listed or non-listed fish and aquatic invertebrates on both an acute and chronic exposure 

basis. In addition, risks to terrestrial birds and mammals also appear to be below the Agency’s 

levels of concern. 

4.2.1 Exposure to Aquatic Organisms
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The Tier II model Pesticide Root Zone Model (PRZM v3.12.2; May 12, 2005; Carousel et al., 

undated) linked with EXposure Analysis Modeling System (EXAMS v2.98.4.6; Apr. 25, 2005; 

Burns, 2004) via the PRZM/EXAMS model shell (PE v5.0, Nov. 15, 2006), i.e., 

PRZM/EXAMS) was used to estimate screening-level exposure concentrations in aquatic 

environments. The PRZM model simulates pesticide movement and transformation on and 

across the agricultural field resulting from crop applications. The EXAMS model simulates 

pesticide concentrations in water due to loading via runoff, erosion, and spray drift, assuming a 

standard 1-ha pond, 2-m deep (20,000 m3) with no outlet that borders a 10-ha treated field. 

Simulations are for multiple (usually 30) years, from which the Agency estimates peak values 

that are expected to recur on average once every ten years, based on time series of daily 

estimated concentrations. 

Model uncertainties are discussed in greater detail in Section 4.3.

4.2.2 Risks to Aquatic Animals

Risks to aquatic systems from acute and chronic exposure to ethaboxam are expected to be low. 

While ethaboxam is classified as “highly toxic” to aquatic invertebrates and “moderately” toxic 

to fish, across the freshwater and estuarine/marine systems, exposure for the seed treatment uses 

is expected to be sufficiently low so as to not trigger risk concerns (all RQs are < 0.01). 

An available chronic midge study suggests that ethaboxam exhibits toxic effects on various 

growth and developmental endpoints. Uncertainties in the study limit the data’s utility in risk 

estimation; however, given that effects were observed in the mg/L range and modeled exposures 

are in the μg/L range, it is unlikely that there will be risks to benthic invertebrates from the 

proposed seed treatment uses of ethaboxam.

4.2.3 Risks to Aquatic Plants

Based on the available information on Pseudokirchneriella subcapitata, the proposed uses of 

ethaboxam as a seed treatment do not exceed the Agency’s LOC for aquatic plants (1.0) for 

nonlisted or listed plants. While RQs were not calculated in the Risk Estimation section due to 

the lack of definitive IC50 values, there were effects noted in the studies. The NOAEC among is 

1.8 mg ai/L (based on biomass and cell density). At that concentration, the RQ is less than 0.01

whereas the LOC is 1.0. 

However, data on a vascular aquatic species are not available. In addition, risk to aquatic 

nonvascular species is typically evaluated with not only the green algae species that was 

submitted, but also with a cyanobacteria, a centric diatom and a pinnate diatom. Acceptable 

studies with these species have not been submitted and are an appreciable source of uncertainty 

in the risk assessment. These planktonic taxa form the basis of the aquatic food web and are 

frequently more sensitive to pesticides than cyanobacteria. While these data gaps create 

appreciable uncertainties in the effects characterization of ethaboxam, the additional non-
-Page 44 of 68-

vascular and vascular species would need to be more than 4 orders of magnitude more sensitive 

than the green algae in order to trigger risk concerns for the proposed uses of ethaboxam as seed 

treatment. Therefore this data is not necessary at this time and risks to aquatic plants are 

expected to be low as a result of minimal exposure. However, this data would be necessary 

should the registrant submit a future registration request for an above-ground spray application 

of ethaboxam. 

4.2.4. Exposure to Terrestrial Organisms

4.2.5. Risks to Mammals

Acute RQs were not calculated for mammals because only non-definitive acute oral toxicity data 

are available. Based on the available acute toxicity data, no mortality was observed in any of the 

mammalian studies conducted on ethaboxam technical at the highest concentrations/doses tested; 

as such, ethaboxam is categorized as “practically nontoxic” to mammals on an acute exposure 

basis. Based on the proposed maximum application rates, combined with the amount of seed per 

acre, the highest exposures occurred for the legume vegetables (e.g., garden peas), resulting in

the highest chronic RQs across all uses of 0.79, less than the chronic risk LOC of 1.0. 

The potential for direct mortality of nonlisted and listed mammals from acute, subacute and 

chronic exposures of ethaboxam treated seed is not expected. 

4.2.6. Risk to Birds

Acute RQs were not calculated for birds because only non-definitive acute and sub-acute toxicity 

endpoints are available. Ethaboxam is categorized as “practically non-toxic” to zebra-finch,

bobwhite quail, and mallard duck on an acute aroal and subacute dietary basis. Treatmentrelated sublethal effects were observed in mallard duck and bobwhite quail studies at the highest 

concentrations tested. Sublethal effects included a decrease in food consumption and weight 

gain. However, the proposed use of ethaboxam as a seed treatment (i.e., low application rate) 

combined with its relatively short half-life in the terrestrial environment suggest that birds will 

not be exposed to sufficient quantities of the chemical to elicit these sublethal responses. 

The potential for direct mortality of nonlisted and listed birds (and to terrestrial-phase amphibian 

and reptiles for which birds serve as surrogates) from acute, subacute and chronic exposures of 

ethaboxam treated seed is not expected. 

4.2.7. Potential Effects on Terrestrial Invertebrates

RQs were not calculated for flying terrestrial invertebrates for several reasons, including: 1) only 

non-definitive toxicity endpoints are available, 2) use of ethaboxam as a seed treatment is not 

likely to result in contact exposure to non-soil dwelling terrestrial invertebrates, such as the 
-Page 45 of 68-

surrogate species the honey bee, and 3) data from the registrant indicate that ethaboxam is not a 

systemic fungicide and would therefore not be found in parts of the plants where they may be 

consumed by terrestrial invertebrates (MRID 48535704). Based on this information, exposure to 

flying terrestrial invertebrates is unlikely from the proposed seed treatment use. 

For soil dwelling invertebrates, results of an acute study with earthworms yielded a 14-day LC50

value greater than 1000 mg ai/kg dw soil (MRID 48535628; Supplemental). Though the actual 

concentrations earthworms were exposed to during the course of the study is uncertain, it is 

likely that the relatively low amounts of ethaboxam present in the soil on and around the treated 

seed would not be enough to elicit a toxic response from earthworms and other subterranean 

terrestrial invertebrates. 

Based on the data available at this time, risks to non-target flying and soil-dwelling invertebrates 

resulting from the proposed use of ethaboxam are not expected.

4.2.8. Risk to Terrestrial Non-target Plants

Risks to terrestrial plants could not be assessed due to a lack of data. The registrant submitted 

data waiver requests for both the seedling emergence and vegetative vigor data requirements 

(MRIDs 48535704 and 48535705, respectively), citing ethaboxam’s low field application rates 

as a seed treatment, relatively rapid soil half-life (1.5 to 6.1 days depending on the soil), and 

fungicidal mechanism of action. While the Agency did not grant the waiver request for the 

seedling emergence data because ethaboxam is chemically active during seed germination and 

may be transmitted off-site via run-off, supporting data provided by the registrant on seed 

germination in the presence of ethaboxam (memo data 10/15/2012) suggest that the relatively 

low application rate of ethaboxam as a seed treatment does not inhibit seed germination. The 

Agency granted the waiver request for the vegetative vigor data because the seed treatment use is 

likely to result in limited exposure to plant foliage. However, seedling emergence and vegetative 

vigor data would be necessary should the registrant submit a future registration request for an 

above-ground spray application of ethaboxam. 

4.3. Uncertainties and Data Gaps

4.3.1. Fate and Transport Uncertanties

Submitted environmental fate studies represent application methods relevant to broadcast 

applications rather than seed treatments, the use pattern relevant to this new chemical 

registration. The formulation applied to the seed and interaction with the seed coat can impact 

the degradation and mobility of ethaboxam. In the absence of field or laboratory data 

demonstrating ethaboxam fate and transport on seed treatments, the rate and route of ethaboxam 

dissipation are uncertainities.

Major degradates of ethaboxam are structurally similar to ethaboxam and are conservatively 
-Page 46 of 68-

assumed to be toxic residues. QSAR estimates from ECOSAR (in Appendix D) indicate LGC32799 to be approximately an order of magnitude more toxic than parent ethaboxam with other 

two-ring degradates predicted to be slightly less toxic (LGC-32533 and LGC-32525). Single-ring 

degradates are predicted to be approximately an order of magnitude less toxic than ethaboxam 

(LGC-32523 and LGC-35525). Degradation estimates cannot be made because concentrations 

of degradate increase to study termination. An aged column leaching study indicates that 

degradates can leach through soil but further characterization of degradate mobility is not 

possible without further data. In the absence of specific degradate fate and transport data, the 

rate and route of ethaboxam degradate dissipation are uncertainties.

Submitted metabolism studies use only an acetone extraction and unextracted residues in aerobic 

soil metabolism studies are 55% to 70% of applied radioactivity by study termination. Without 

demonstrating additional extractions, the bioavailability of these unextracted residues is an 

uncertainty. An aerobic soil metabolism study employing additional extraction techniques is 

being submitted and preliminary results indicate lower unextracted residues. The review of this 

study has potential to reduce uncertainity associated with the unextracted residues.

4.3.2. Effects Uncertainties

There are several notable data gaps and uncertainties in the characterization of toxic effects for 

ethaboxam, including an incomplete dataset for aquatic vascular and non-vascular plants, and a 

complete lack of terrestrial plant data. While potential exposure to ethaboxam from the proposed 

seed treatment uses is expected to be low enough to mitigate some of the concerns associated 

with these data gaps, these data would be necessary to assess risks from any future registration 

requests for an above-ground spray applications of ethaboxam. In the absence of this data risks to 

aquatic and vascular plants may be presumed. 

In addition, chronic toxicity data for an estuarine/marine invertebrate are not available. 

Therefore, an acute-to-chronic ratio (ACR) based on the daphnid was applied. The ACR is 

considered protective for the purpose of this risk assessment; however, the application of an 

ACR in the absence of actual data does introduce uncertainty to the risk assessment.

5. Federally Threatened and Endangered (Listed) Species Concerns

Section 7 of the Endangered Species Act, 16 U.S.C. Section 1536(a)(2), requires all federal 

agencies to consult with the National Marine Fisheries Service (NMFS) for marine and 

anadromous listed species, and/or the United States Fish and Wildlife Service (USFWS) for 

listed wildlife and freshwater organisms, if they are proposing an "action" that may affect listed 

species or their designated critical habitat. Each federal agency is required under the Act to 

ensure that any action they authorize, fund, or carry out is not likely to jeopardize the continued 

existence of a listed species or result in the destruction or adverse modification of designated 

critical habitat. To jeopardize the continued existence of a listed species means "to engage in an 

action that reasonably would be expected, directly or indirectly, to reduce appreciably the 
-Page 47 of 68-

likelihood of both the survival and recovery of a listed species in the wild by reducing the 

reproduction, numbers, or distribution of the species" (50 C.F.R. § 402.02).

To facilitate compliance with the requirements of the Endangered Species Act (subsection 

(a)(2)), the Office of Pesticide Programs has established procedures to evaluate whether a 

proposed registration action may directly or indirectly appreciably reduce the likelihood of both 

the survival and recovery of a listed species in the wild by reducing the reproduction, numbers, 

or distribution of any listed species (USEPA, 2004). After the Agency’s screening level risk 

assessment is conducted, if any of the Agency’s listed species’ LOCs are exceeded for either 

direct or indirect effects, an analysis is conducted to determine if any listed or candidate species 

may co-occur in the area of the proposed pesticide use or areas downstream or downwind that 

could be contaminated from drift or runoff/erosion. If listed or candidate species may be present 

in the proposed action area, further biological assessment is undertaken. The extent to which 

listed species may be at risk is considered, which then determines the need for the development 

of a more comprehensive consultation package, as required by the Endangered Species Act.

The federal action addressed herein is the proposed new registration of ethaboxam on 

agricultural use sites; it is expected that its use could occur nationwide.

5.1. Action Area

For listed species assessment purposes, the action area is considered to be the area affected 

directly or indirectly by ethaboxam use and not merely the immediate area where ethaboxam is 

applied. At the initial baseline, the risk assessment considers broadly described taxonomic 

groups and conservatively assumes that listed species within those broad groups are co-located 

with the pesticide treatment area. This means that listed terrestrial plants and wildlife are 

assumed to be located on or adjacent to the treated site and listed aquatic organisms are assumed 

to be located in a surface water body adjacent to the treated site. The assessment also assumes 

that the listed species are located within an assumed area, which has the relatively highest 

potential exposure to the pesticide, and that exposures are likely to decrease with distance from 

the treatment area. Section 3.1 of this risk assessment presents the proposed pesticide use sites 

that are used to establish initial co-location of species with treatment areas.

5.2. Taxonomic Groups Potentially at Risk 

If the assumptions associated with the baseline action area result in RQs that are below the listed 

species LOCs, a "no effect" determination conclusion is made with respect to listed species in 

that taxa, and no further refinement of the action area is necessary. Furthermore, RQs below the 

listed species LOCs for a given taxonomic group indicate no concern for indirect effects on listed 

species that depend upon the taxonomic group for which the RQ was calculated. However, in 

situations where the screening assumptions lead to RQs in excess of the listed species LOCs for a 

given taxonomic group, a potential for a "may affect" conclusion exists and may be associated 

with direct effects on listed species belonging to that taxonomic group or may extend to indirect 

effects upon listed species that depend upon that taxonomic group as a resource. In such cases, 

additional information on the biology of listed species, the locations of these species, and the 
-Page 48 of 68-

locations of use sites are considered to determine the extent to which screening assumptions 

regarding an action area apply to a particular listed organism. These subsequent refinement steps 

will consider how this information would impact the action area for a particular listed organism 

and potentially include areas of exposure that are downwind and downstream of the pesticide use 

site.

Assessment endpoints, exposure pathways, and the conceptual models addressing proposed new 

ethaboxam uses, and the associated exposure and effects analyses conducted for ethaboxam

baseline risk assessment are in Sections 2 to 3. The assessment endpoints used in the baseline

risk assessment include those defined operationally as reduced survival and reproductive 

impairment for both aquatic and terrestrial animal species and survival, reproduction, and growth 

of aquatic and terrestrial plant species from both direct acute and chronic exposures. These 

assessment endpoints are intended to address the standard set forth in the Endangered Species 

Act requiring federal agencies to ensure that any action they authorize does not appreciably 

reduce the likelihood of both the survival and recovery of a listed species in the wild by reducing 

the reproduction, numbers, or distribution of the species. Risk estimates (RQs) which, 

integrating exposure and effects, are calculated for broad based taxonomic groups in the 

screening-level risk assessment presented in Section 4.

Both acute endangered species and chronic risk LOCs are considered in the baseline risk 

assessment to identify direct and indirect effects to taxa of listed species. This section identifies 

direct effect concerns, by taxa that are triggered by exceeding endangered LOCs in the baseline

risk assessment, with an evaluation of the potential probability of individual effects for exposures 

that may occur at the established endangered species LOC. Data on exposure and effects 

collected under field and laboratory conditions are evaluated to make determinations on the 

predictive utility of the direct effect screening assessment findings to listed species. There were 

no LOC exceedances for any assessed taxa. 

Table 5.1. Potential Effects to Federally Listed Taxa Associated with Direct or Indirect 

Effects from the Proposed New Uses of Ethaboxam.

Listed Taxon Direct Effects Indirect Effectsa

Terrestrial and semi-aquatic plants - monocots No No

Terrestrial and semi-aquatic plants - dicots No No

Birds No No

Terrestrial-phase amphibians and reptiles No No

Mammals No No

Aquatic nonvascular plants No No

Aquatic vascular plants No No

Freshwater fish No No

Aquatic-phase amphibians No No

Freshwater invertebrates No No

Mollusks No No

Marine/estuarine fish No No

Marine/estuarine invertebrates No No a

direct effects are not expected for any taxa, therefore, indirect effects are not expected either. 
-Page 49 of 68-

5.2.1. Probit Dose-Response Analysis 

The Agency uses the probit dose-response relationship as a tool for providing additional 

information on the potential for acute direct effects to aquatic and terrestrial animals (USEPA, 

2004). As part of this evaluation, the acute RQ for listed species is presented in terms of the 

chance of an individual event (i.e., mortality or immobilization) should exposure at the EEC 

actually occur for a species with sensitivity to ethaboxam on par with the acute toxicity endpoint 

selected for RQ calculation. To accomplish this interpretation, the Agency uses the slope of the 

dose-response relationship available from the toxicity study used to establish the acute toxicity 

measures of effect for each taxonomic group that is relevant to this assessment. The individual 

effects probability associated with the acute RQ is based on the mean estimate of the slope and 

an assumption of a probit dose-response relationship. In addition to a single effects probability 

estimate based on the mean, upper and lower estimates of the effects probability are also 

provided to account for variance in the slope, if available. Based on the available acute toxicity 

for ethaboxam, a summary of the probit dose-response analysis is provided in Table 5.2. If no 

dose response information is available to estimate a slope for this analysis, a default slope 

assumption of 4.5 (with lower and upper bounds of 2 to 9) (Urban and Cook, 1986) is used. 

Individual effect probabilities are calculated based on an Excel spreadsheet tool IECV1.1 

(Individual Effect Chance Model Version 1.1) developed by the U.S. EPA, OPP, Environmental 

Fate and Effects Division (June 22, 2004). The model allows for such calculations by entering 

the mean slope estimate (and the 95% confidence bounds of that estimate) as the slope parameter 

for the spreadsheet. The desired threshold for the probability of an individual effect is entered as 

the listed species LOC. In addition, the probability of an individual effect is also derived based 

on the calculated acute RQ, if available.

Table 5.2. Summary of Ethaboxam Probit Dose Response Analysis for Listed Species

Taxa (study type) Acute Effect

Slope (95% C.I.)

Chance of Individual 

Effect at Listed Species 

LOC (95% C.I.)

Chance of Individual 

Effect at Derived Acute 

RQ1,2 (95% C.I.)

Bird oral dose No mortality observed 1 in 2.9E+05

(1 in 44 to 1 in 8.86E+18)

Not calculated; no 

mortality observed

Bird dietary No mortality observed 1 in 2.9E+05

(1 in 44 to 1 in 8.86E+18)

Not calculated; no 

mortality observed

Mammal oral dose No mortality observed

1 in 4.3E+03

(1 in 2.21 to 1 in 

3.57E+12)

Not calculated; no 

mortality observed

Freshwater Fish

Mortality 

Default Slope = 4.5 

(2 – 9)

1 in 4.18E+08

(1 in 2.16E+02 to 1 in 

1.75E+31)

1 in 6.12E+61

(1 in 1.45E+13 to 1 in 

3.80E+242)

1

Freshwater invertebrates 

Mortality

Default Slope = 4.5 

(2 – 9)

1 in 4.18E+08

(1 in 2.16E+02 to 1 in 

1.75E+31)

1 in 1.28E+41

(1 in 1.01E+09 to 1 in 

1.35E+160)

2

1 Acute RQ for freshwater Fish = 0.0002. 2 Acute RQ for freshwater invertebrates = 0.001.

As shown in Table 5.2, the probability for acute direct effects (i.e., mortality) to individual listed 

fish or invertebrates is very low. 
-Page 50 of 68-

5.2.2. Listed Species Occurrence Associated with Ethaboxam Use

The goal of the co-location analysis is to determine whether sites of pesticide use are 

geographically associated with known locations of listed species [following the convention of the 

Services, the word ‘species’ in this assessment may apply to a ‘species’, ‘subspecies’, or an 

Evolutionary Significant Unit (ESU)]. At the screening level, this analysis is accomplished 

using the LOCATES database (version 2.10.3). The database uses location information for listed 

species at the county level and compares it to agricultural census data (from 2002) for crop 

production at the same county level of resolution. The product is a listing of Federally-listed 

species that are located in counties known to produce the crops upon which the pesticide will be 

used. This analysis has not been conducted for this assessment.

6. References

Carousel, R.F., J.C. Imhoff, P.R. Hummel, J.M. Cheplick, A.S. Donigian, Jr., L.A. Suarez. 

Undated. PRZM-3, A Model for Predicting Pesticide and Nitrogen Fate in the Crop Root 

and Unsaturated Soil Zones: Users Manual for Release 3.12.2. National Exposure 

Research Laboratory, Office of Research and Development, U.S. Environmental 

Protection Agency, Athens, GA; AQUA TERRA Consultants, Mountain View, CA; 

Waterborne Environmental, Inc., Leesburg, VA.

Goring, C.A.I., D.A. Laskowki, J.H. Hamaker, and R.W. Meikle. 1975. Principles of pesticide 

degradation in soil. Pages 135-172 in (R. Haque and V.H. Freed, eds.) Environmental 

dynamics of pesticides. Plenum Press, New York.

USEPA 1998. Guidelines for Ecological Risk Assessment. EPA/630/R-95/002F. Published in 

63 FR 26846; May 14, 1998. U.S. Environmental Protection Agency, Washington, DC. 

April, 1998.

USEPA. 2004. Overview of the Ecological Risk Assessment Process in the Office of Pesticide 

Programs, U.S. Environmental Protection Agency. Endangered and Threatened Species 

Effects Determinations. Office of Prevention, Pesticides and Toxic Substances, Office of 

Pesticide Programs, Washington, D.C. January 23, 2004. Online at: 

http://www.epa.gov/oppfead1/endanger/consultation/ecorisk-overview.pdf

USEPA 2006a. Standardized Soil Mobility Classification Guidance. U.S. Environmental 

Protection Agency, Office of Prevention, Pesticides and Toxic Substances, Office of 

Pesticide Programs, Environmental Fate and Effects Division, Memorandum. Apr. 21, 

2006.

USEPA. 2006b. User’s Guide: TerrPlant Version 1.2.2 (Terrestrial Residue Exposure model). 

United States Environmental Protection Agency. Environmental Fate and Effects 
-Page 51 of 68-

Division. Office of Pesticide Programs. U.S. Environmental protection Agency. 

Washington, D.C. December 26, 2006.

USEPA 2008. White Paper on Methods for Assessing Ecological Risks of Pesticides with 

Persistent, Bioaccumulative and Toxic Characteristics. Submitted to the FIFRA Scientific 

Advisory Panel. October 28-31, 2008. Office of Pesticide Programs, Environmental Fate 

and Effects Division, Washington, D.C.

USEPA 2009. Guidance for Selecting Input Parameters in Modeling the Environmental Fate and 

Transport of Pesticides. U.S. Environmental Protection Agency, Office of Prevention, 

Pesticides and Toxic Substances, Office of Pesticide Programs, Environmental Fate and 

Effects Division, Oct. 22, 2009. Online at: 

http://www.epa.gov/oppefed1/models/water/input_parameter_guidance.htm

USEPA. 2011b. Water Models. U.S. Environmental Protection Agency, Pesticides: Science 

and Policy, Models and Databases. Last updated Aug. 8, 2011. Online at: 

http://www.epa.gov/oppefed1/models/water/

USEPA. 2011c. DRAFT: Registration Review: Problem Formulation for the Environmental 

Fate and Ecological Risk, Endangered Species, and Drinking Water Exposure 

Assessments of Clothianidin" DP barcode 391491. 

USDA. 2000. USDA Crop Profiles. Hosted by the Integrated Pest Management Centers. 

Available online at: http://www.ipmcenters.org/cropprofiles/index.cfm. 

USFWS/NMFS. 2004. 50 CFR Part 402. Joint Counterpart Endangered Species Act Section 7 

Consultation Regulations; Final Rule. FR 47732-47762.

Urban, D.J. and N.J. Cook, 1986. Hazard Evaluation Division Standard Evaluation Procedure 

Ecological Risk Assessment. EPA 540/9-85-001. U.S. Environmental Protection 

Agency, Office of Pesticide Programs, Washington D.C.

6.1. Submitted Environmental Fate and Transport Studies

6.2. Submitted Ecotoxicity Studies
-Page 52 of 68-

1 Appendix A. Summary of Environmental Fate Data
-Page 53 of 68-

2 Appendix B. Aquatic Model Input/Output Data.

3

4 Example Input/Output Data for Individual Simulations

5

6 PRZM/EXAMS Example Input/Output File.

7

8 stored as MSsoybean.out

9 Chemical: ethaboxam

10 PRZM environment: MSsoybeanSTD.txt modified Tueday, 29 May 2007 at 13:58:06

11 EXAMS environment: pond298.exv modified Tueday, 26 August 2008 at 06:14:08

12 Metfile: w03940.dvf modified Tueday, 26 August 2008 at 06:14:14

13 Water segment concentrations (ppb)

14

15 Year Peak 96 hr 21 Day 60 Day 90 Day Yearly

16 1961 0.4608 0.4416 0.4089 0.3538 0.3273 0.172

17 1962 0.4704 0.4534 0.3793 0.3127 0.2897 0.1903

18 1963 0.2349 0.2284 0.205 0.1871 0.1872 0.1626

19 1964 0.4015 0.38 0.3311 0.2968 0.2773 0.1689

20 1965 0.2539 0.2483 0.2324 0.2076 0.1951 0.1288

21 1966 0.2132 0.2087 0.1902 0.1767 0.1692 0.1151

22 1967 0.3236 0.3099 0.269 0.2278 0.2128 0.1523

23 1968 0.3345 0.3252 0.2896 0.2599 0.2423 0.1733

24 1969 0.4377 0.4201 0.3637 0.3212 0.3032 0.2212

25 1970 0.371 0.3646 0.3322 0.3097 0.2959 0.2033

26 1971 0.315 0.3047 0.289 0.2541 0.2405 0.1651

27 1972 0.1746 0.1712 0.1681 0.1528 0.1457 0.1135

28 1973 0.4506 0.4363 0.3682 0.3162 0.2969 0.1908

29 1974 0.3969 0.3799 0.3337 0.2861 0.2652 0.1726

30 1975 0.2053 0.2009 0.1902 0.1704 0.1605 0.1046

31 1976 0.44 0.4148 0.3771 0.333 0.3059 0.1814

32 1977 0.3975 0.381 0.3383 0.2925 0.2737 0.1834

33 1978 0.2161 0.2105 0.2015 0.1783 0.1702 0.1305

34 1979 0.6651 0.6088 0.4495 0.3302 0.2881 0.1334

35 1980 0.5456 0.512 0.4709 0.3743 0.321 0.1867

36 1981 0.2224 0.2181 0.2093 0.1917 0.1883 0.1467

37 1982 0.3476 0.3362 0.3083 0.2731 0.2634 0.1552

38 1983 0.5707 0.5339 0.4417 0.2894 0.2484 0.1394

39 1984 0.1695 0.166 0.1545 0.1411 0.1359 0.09931

40 1985 0.08929 0.08839 0.08607 0.08371 0.08152 0.06383

41 1986 0.2519 0.2447 0.2197 0.189 0.1893 0.1296

42 1987 0.3459 0.3348 0.3082 0.2746 0.2577 0.1728

43 1988 0.4375 0.4228 0.3739 0.3302 0.3095 0.2132

44 1989 0.2976 0.2891 0.266 0.2398 0.2301 0.1659

45 1990 0.192 0.1868 0.1708 0.1549 0.1467 0.1061

46

47 Sorted results

48 Prob. Peak 96 hr 21 Day 60 Day 90 Day Yearly

49 0.032258064516129 0.6651 0.6088 0.4709 0.3743 0.3273 0.2212

50 0.0645161290322581 0.5707 0.5339 0.4495 0.3538 0.321 0.2132

51 0.0967741935483871 0.5456 0.512 0.4417 0.333 0.3095 0.2033

52 0.129032258064516 0.4704 0.4534 0.4089 0.3302 0.3059 0.1908

53 0.161290322580645 0.4608 0.4416 0.3793 0.3302 0.3032 0.1903

54 0.193548387096774 0.4506 0.4363 0.3771 0.3212 0.2969 0.1867

55 0.225806451612903 0.44 0.4228 0.3739 0.3162 0.2959 0.1834
-Page 54 of 68-

56 0.258064516129032 0.4377 0.4201 0.3682 0.3127 0.2897 0.1814

57 0.290322580645161 0.4375 0.4148 0.3637 0.3097 0.2881 0.1733

58 0.32258064516129 0.4015 0.381 0.3383 0.2968 0.2773 0.1728

59 0.354838709677419 0.3975 0.38 0.3337 0.2925 0.2737 0.1726

60 0.387096774193548 0.3969 0.3799 0.3322 0.2894 0.2652 0.172

61 0.419354838709677 0.371 0.3646 0.3311 0.2861 0.2634 0.1689

62 0.451612903225806 0.3476 0.3362 0.3083 0.2746 0.2577 0.1659

63 0.483870967741936 0.3459 0.3348 0.3082 0.2731 0.2484 0.1651

64 0.516129032258065 0.3345 0.3252 0.2896 0.2599 0.2423 0.1626

65 0.548387096774194 0.3236 0.3099 0.289 0.2541 0.2405 0.1552

66 0.580645161290323 0.315 0.3047 0.269 0.2398 0.2301 0.1523

67 0.612903225806452 0.2976 0.2891 0.266 0.2278 0.2128 0.1467

68 0.645161290322581 0.2539 0.2483 0.2324 0.2076 0.1951 0.1394

69 0.67741935483871 0.2519 0.2447 0.2197 0.1917 0.1893 0.1334

70 0.709677419354839 0.2349 0.2284 0.2093 0.189 0.1883 0.1305

71 0.741935483870968 0.2224 0.2181 0.205 0.1871 0.1872 0.1296

72 0.774193548387097 0.2161 0.2105 0.2015 0.1783 0.1702 0.1288

73 0.806451612903226 0.2132 0.2087 0.1902 0.1767 0.1692 0.1151

74 0.838709677419355 0.2053 0.2009 0.1902 0.1704 0.1605 0.1135

75 0.870967741935484 0.192 0.1868 0.1708 0.1549 0.1467 0.1061

76 0.903225806451613 0.1746 0.1712 0.1681 0.1528 0.1457 0.1046

77 0.935483870967742 0.1695 0.166 0.1545 0.1411 0.1359 0.09931

78 0.967741935483871 0.08929 0.08839 0.08607 0.08371 0.08152 0.06383

79

80 0.1 0.53808 0.50614 0.43842 0.33272 0.30914 0.20205

81 Average of yearly averages: 0.154728

82

83 Inputs generated by pe5.pl - Novemeber 2006

84

85 Data used for this run:

86 Output File: MSsoybean

87 Metfile: w03940.dvf

88 PRZM scenario: MSsoybeanSTD.txt

89 EXAMS environment file: pond298.exv

90 Chemical Name: ethaboxam

91 Description Variable Name Value Units Comments

92 Molecular weightmwt 320.43 g/mol

93 Henry's Law Const. henry 3.8E-8 atm-m^3/mol

94 Vapor Pressure vapr 6.1E-7 torr

95 Solubility sol 5.2 mg/L

96 Kd Kd mg/L

97 Koc Koc 696 mg/L

98 Photolysis half-life kdp 0 days Half-life

99 Aerobic Aquatic Metabolism kbacw 373 days Halfife

100 Anaerobic Aquatic Metabolism kbacs 3861 days Halfife

101 Aerobic Soil Metabolism asm 119 days Halfife

102 Hydrolysis: pH 7 0 days Half-life

103 Method: CAM 4 integer See PRZM manual

104 Incorporation Depth: DEPI 5 cm

105 Application Rate:TAPP 0.0695 kg/ha

106 Application Efficiency: APPEFF1.0 fraction

107 Spray Drift DRFT 0.0 fraction of application rate applied to pond

108 Application Date Date 16-3 dd/mm or dd/mmm or dd-mm or dd-mmm

109 Record 17: FILTRA

110 IPSCND1

111 UPTKF
-Page 55 of 68-

112 Record 18: PLVKRT

113 PLDKRT

114 FEXTRC 0.5

115 Flag for Index Res. Run IR EPA Pond

116 Flag for runoff calc. RUNOFF none, monthly or total(average of entire run)
-Page 56 of 68-

117 Appendix C. Model Outputs

118

119

120 T-REX Model Outputs

Animal Size Crop Maximu

m 

Applicati

on Rate

Maximum 

Seed 

Applicatio

n Rate

Avian 

Nagy Dose

Mammalia

n Nagy 

Dose

Availa

ble AI

(lbs ai/A) (mg ai/kg 

seed)

(mg ai/kgbw/day)(mg ai/kgbw/day)(mg ai 

ft-2)

Small pea, garden 0.05 133.54 33.80 28.29 0.57

Medium 19.27 19.55

Large 8.63 4.53

Crop Risk Quotients†

Avian (20 g) Mammalian (15 g)

Acute (# 1) Acute (# 

2)

Chronic Acute (# 1) Acute (# 2) Chroni

c

pea, garden 0.02 0.02 0.79 0.00 0.00 0.79

Avian (100 g) Mammalian (35 g)

Acute (# 1) Acute (# 

2)

Chronic Acute (# 1) Acute (# 2) Chroni

c

pea, garden 0.01 0.00 0.79 0.00 0.00 0.68

Avian (1000 g) Mammalian (1000 g)

Acute (# 1) Acute (# 

2)

Chronic Acute (# 1) Acute (# 2) Chroni

c

pea, garden 0.00 0.00 0.79 0.00 0.00 0.36

121

122

Animal Size Crop Maximu

m 

Applicati

on Rate

Maximum 

Seed 

Applicatio

n Rate

Avian 

Nagy Dose

Mammalia

n Nagy 

Dose

Availa

ble AI

(lbs ai/A) (mg ai/kg 

seed)

(mg ai/kgbw/day)(mg ai/kgbw/day)(mg ai 

ft-2)

Small canola 0.00 66.77 16.90 14.15 0.02

Medium 9.64 9.78

Large 4.31 2.27
-Page 57 of 68-

Crop Risk Quotients†

Avian (20 g) Mammalian (15 g)

Acute (# 1) Acute (# 

2)

Chronic Acute (# 1) Acute (# 2) Chroni

c

canola 0.01 0.00 0.39 0.00 0.00 0.40

Avian (100 g) Mammalian (35 g)

Acute (# 1) Acute (# 

2)

Chronic Acute (# 1) Acute (# 2) Chroni

c

canola 0.01 0.00 0.39 0.00 0.00 0.34

Avian (1000 g) Mammalian (1000 g)

Acute (# 1) Acute (# 

2)

Chronic Acute (# 1) Acute (# 2) Chroni

c

canola 0.00 0.00 0.39 0.00 0.00 0.18

123

Animal Size Crop Maximu

m 

Applicati

on Rate

Maximum 

Seed 

Applicatio

n Rate

Avian 

Nagy Dose

Mammalia

n Nagy 

Dose

Availa

ble AI

(lbs ai/A) (mg ai/kg 

seed)

(mg ai/kgbw/day)(mg ai/kgbw/day)(mg ai 

ft-2)

Small wheat, all or 

unspecified

0.01 57.87 14.65 12.26 0.09

Medium 8.35 8.47

Large 3.74 1.96

Crop Risk Quotients†

Avian (20 g) Mammalian (15 g)

Acute (# 1) Acute (# 

2)

Chronic Acute (# 1) Acute (# 2) Chroni

c

wheat, all or 

unspecified

0.01 0.00 0.34 0.00 0.00 0.34

Avian (100 g) Mammalian (35 g)

Acute (# 1) Acute (# 

2)

Chronic Acute (# 1) Acute (# 2) Chroni

c

wheat, all or 

unspecified

0.00 0.00 0.34 0.00 0.00 0.29

Avian (1000 g) Mammalian (1000 g)
-Page 58 of 68-

Acute (# 1) Acute (# 

2)

Chronic Acute (# 1) Acute (# 2) Chroni

c

wheat, all or 

unspecified

0.00 0.00 0.34 0.00 0.00 0.16

124

125

126

127

128
-Page 59 of 68-

129

130 Appendix D Ethaboxam and Degradate ECOSAR Estimates

131

132 ECOSAR Version 1.11 Results Page

133

134 SMILES : CCNc1nc(CC)c(s1)C(=O)NC(C(#N))c2cccs2

135 CHEM : 

136 CAS Num: 

137 ChemID1: 

138 MOL FOR: C14 H16 N4 O1 S2 

139 MOL WT : 320.43

140 Log Kow: 3.092 (EPISuite Kowwin v1.68 Estimate)

141 Log Kow: 2.890 (User Entered)

142 Log Kow: (PhysProp DB exp value - for comparison only)

143 Melt Pt: 185.00 (deg C, User Entered for Wat Sol estimate)

144 Melt Pt: (deg C, PhysProp DB exp value for Wat Sol estimate)

145 Wat Sol: 3.839 (mg/L, EPISuite WSKowwin v1.43 Estimate)

146 Wat Sol: 12.4 (mg/L, User Entered)

147 Wat Sol: (PhysProp DB exp value)

148

149

150 --------------------------------------

151 Values used to Generate ECOSAR Profile

152 --------------------------------------

153 Log Kow: 2.890 (User Entered)

154 Wat Sol: 12.4 (mg/L, User Entered)

155

156

157

158 --------------------------------------

159 ECOSAR v1.11 Class-specific Estimations

160 --------------------------------------

161 Thiophenes

162 Amides 

163 Benzyl Nitriles 

164 Predicted

165 ECOSAR Class Organism Duration End Pt mg/L (ppm)

166 =========================== ================== ======== ====== ==========

167 Thiophenes : Fish 96-hr LC50 13.311 *

168 Thiophenes : Daphnid 48-hr LC50 9.199

169 Thiophenes : Green Algae 96-hr EC50 15.135 *

170 Thiophenes : Fish ChV 1.014 !

171 Thiophenes : Daphnid ChV 0.938 !

172 Thiophenes : Green Algae ChV 13.217 *

173

174 Amides : Fish 96-hr LC50 22.110 *

175 Amides : Daphnid 48-hr LC50 16.155 *

176 Amides : Green Algae 96-hr EC50 0.843

177 Amides : Fish ChV 0.064

178 Amides : Daphnid ChV 1.631

179 Amides : Green Algae ChV 1.152

180 Amides : Fish (SW) 96-hr LC50 19.707 *

181 Amides : Mysid (SW) 96-hr LC50 1.650

182

183 Benzyl Nitriles : Fish 96-hr LC50 6.939

184 Benzyl Nitriles : Daphnid 48-hr LC50 47.128 *

185 Benzyl Nitriles : Green Algae 96-hr EC50 1.775

186 Benzyl Nitriles : Fish ChV 0.957

187 Benzyl Nitriles : Daphnid ChV 0.650

188 Benzyl Nitriles : Green Algae ChV 1.140
-Page 60 of 68-

189 Benzyl Nitriles : Fish (SW) 96-hr LC50 11.179

190 Benzyl Nitriles : Mysid (SW) 96-hr LC50 0.804

191

192 =========================== ================== ======== ====== ==========

193 Neutral Organic SAR : Fish 96-hr LC50 41.785 *

194 (Baseline Toxicity) : Daphnid 48-hr LC50 25.758 *

195 : Green Algae 96-hr EC50 26.951 *

196 : Fish ChV 4.500

197 : Daphnid ChV 3.157

198 : Green Algae ChV 8.475

199

200 Note: * = asterisk designates: Chemical may not be soluble enough to

201 measure this predicted effect. If the effect level exceeds the

202 water solubility by 10X, typically no effects at saturation (NES)

203 are reported.

204

205 NOTE: ! = exclamation designates: The toxicity value was estimated through

206 application of acute-to-chronic ratios per methods outlined in

207 the ECOSAR Methodology Document provided in the ECOSAR Help Menu.

208

209

210 ------------------------------

211 Class Specific LogKow Cut-Offs

212 ------------------------------

213 If the log Kow of the chemical is greater than the endpoint specific cut-offs

214 presented below, then no effects at saturation are expected for those endpoints.

215

216 Thiophenes:

217 ----------

218 Maximum LogKow: 5.0 (LC50)

219 Maximum LogKow: 6.4 (EC50)

220 Maximum LogKow: 8.0 (ChV)

221

222 Amides :

223 -------

224 Maximum LogKow: >8.5 (LC50)

225 Maximum LogKow: >8.0 (EC50,ChV)

226

227 Benzyl Nitriles :

228 ----------------

229 Maximum LogKow: 5.0 (LC50)

230 Maximum LogKow: 6.4 (Green Algae EC50)

231 Maximum LogKow: 8.0 (Chronic Values)

232

233 Baseline Toxicity SAR Limitations:

234 ---------------------------------

235 Maximum LogKow: 5.0 (Fish 96-hr LC50; Daphnid LC50)

236 Maximum LogKow: 6.4 (Green Algae EC50)

237 Maximum LogKow: 8.0 (ChV)

238

239

240

241 ------------------------------------------------------------------------------

242

243 ECOSAR Version 1.11 Results Page

244

245 SMILES : CCNc1nc(CC)c(s1)C(=O)N

246 CHEM : LGC-32523

247 CAS Num: 

248 ChemID1: 

249 MOL FOR: C8 H13 N3 O1 S1 

250 MOL WT : 199.27
-Page 61 of 68-

251 Log Kow: 1.648 (EPISuite Kowwin v1.68 Estimate)

252 Log Kow: (User Entered)

253 Log Kow: (PhysProp DB exp value - for comparison only)

254 Melt Pt: (User Entered for Wat Sol estimate)

255 Melt Pt: (deg C, PhysProp DB exp value for Wat Sol estimate)

256 Wat Sol: 1728 (mg/L, EPISuite WSKowwin v1.43 Estimate)

257 Wat Sol: (User Entered)

258 Wat Sol: (PhysProp DB exp value)

259

260

261 --------------------------------------

262 Values used to Generate ECOSAR Profile

263 --------------------------------------

264 Log Kow: 1.648 (EPISuite Kowwin v1.68 Estimate)

265 Wat Sol: 1728 (mg/L, EPISuite WSKowwin v1.43 Estimate)

266

267

268

269 --------------------------------------

270 ECOSAR v1.11 Class-specific Estimations

271 --------------------------------------

272 Amides 

273 Predicted

274 ECOSAR Class Organism Duration End Pt mg/L (ppm)

275 =========================== ================== ======== ====== ==========

276 Amides : Fish 96-hr LC50 106.300

277 Amides : Daphnid 48-hr LC50 137.654

278 Amides : Green Algae 96-hr EC50 3.098

279 Amides : Fish ChV 0.148

280 Amides : Daphnid ChV 6.120

281 Amides : Green Algae ChV 2.509

282 Amides : Fish (SW) 96-hr LC50 93.559

283 Amides : Mysid (SW) 96-hr LC50 5.295

284

285 =========================== ================== ======== ====== ==========

286 Neutral Organic SAR : Fish 96-hr LC50 339.053

287 (Baseline Toxicity) : Daphnid 48-hr LC50 186.358

288 : Green Algae 96-hr EC50 121.359

289 : Fish ChV 31.894

290 : Daphnid ChV 16.602

291 : Green Algae ChV 29.562

292

293 Note: * = asterisk designates: Chemical may not be soluble enough to

294 measure this predicted effect. If the effect level exceeds the

295 water solubility by 10X, typically no effects at saturation (NES)

296 are reported.

297

298

299 ------------------------------

300 Class Specific LogKow Cut-Offs

301 ------------------------------

302 If the log Kow of the chemical is greater than the endpoint specific cut-offs

303 presented below, then no effects at saturation are expected for those endpoints.

304

305 Amides :

306 -------

307 Maximum LogKow: >8.5 (LC50)

308 Maximum LogKow: >8.0 (EC50,ChV)

309

310 Baseline Toxicity SAR Limitations:

311 ---------------------------------

312 Maximum LogKow: 5.0 (Fish 96-hr LC50; Daphnid LC50)
-Page 62 of 68-

313 Maximum LogKow: 6.4 (Green Algae EC50)

314 Maximum LogKow: 8.0 (ChV)

315

316

317

318 ------------------------------------------------------------------------------

319

320 ECOSAR Version 1.11 Results Page

321

322 SMILES : CCNc1nc(CC)c(s1)C(=O)NC(C(=O)N)c2cccs2

323 CHEM : LGC-32525

324 CAS Num: 

325 ChemID1: 

326 MOL FOR: C14 H18 N4 O2 S2 

327 MOL WT : 338.44

328 Log Kow: 2.324 (EPISuite Kowwin v1.68 Estimate)

329 Log Kow: (User Entered)

330 Log Kow: (PhysProp DB exp value - for comparison only)

331 Melt Pt: (User Entered for Wat Sol estimate)

332 Melt Pt: (deg C, PhysProp DB exp value for Wat Sol estimate)

333 Wat Sol: 75.36 (mg/L, EPISuite WSKowwin v1.43 Estimate)

334 Wat Sol: (User Entered)

335 Wat Sol: (PhysProp DB exp value)

336

337

338 --------------------------------------

339 Values used to Generate ECOSAR Profile

340 --------------------------------------

341 Log Kow: 2.324 (EPISuite Kowwin v1.68 Estimate)

342 Wat Sol: 75.36 (mg/L, EPISuite WSKowwin v1.43 Estimate)

343

344

345

346 --------------------------------------

347 ECOSAR v1.11 Class-specific Estimations

348 --------------------------------------

349 Thiophenes

350 Amides 

351 Predicted

352 ECOSAR Class Organism Duration End Pt mg/L (ppm)

353 =========================== ================== ======== ====== ==========

354 Thiophenes : Fish 96-hr LC50 34.269

355 Thiophenes : Daphnid 48-hr LC50 22.631

356 Thiophenes : Green Algae 96-hr EC50 42.692

357 Thiophenes : Fish ChV 2.753 !

358 Thiophenes : Daphnid ChV 2.291 !

359 Thiophenes : Green Algae ChV 32.203

360

361 Amides : Fish 96-hr LC50 59.335

362 Amides : Daphnid 48-hr LC50 56.278

363 Amides : Green Algae 96-hr EC50 2.001

364 Amides : Fish ChV 0.123

365 Amides : Daphnid ChV 3.909

366 Amides : Green Algae ChV 2.154

367 Amides : Fish (SW) 96-hr LC50 52.582

368 Amides : Mysid (SW) 96-hr LC50 3.683

369

370 =========================== ================== ======== ====== ==========

371 Neutral Organic SAR : Fish 96-hr LC50 142.355 *

372 (Baseline Toxicity) : Daphnid 48-hr LC50 83.282 *

373 : Green Algae 96-hr EC50 70.198

374 : Fish ChV 14.414
-Page 63 of 68-

375 : Daphnid ChV 8.826

376 : Green Algae ChV 19.648

377

378 Note: * = asterisk designates: Chemical may not be soluble enough to

379 measure this predicted effect. If the effect level exceeds the

380 water solubility by 10X, typically no effects at saturation (NES)

381 are reported.

382

383 NOTE: ! = exclamation designates: The toxicity value was estimated through

384 application of acute-to-chronic ratios per methods outlined in

385 the ECOSAR Methodology Document provided in the ECOSAR Help Menu.

386

387

388 ------------------------------

389 Class Specific LogKow Cut-Offs

390 ------------------------------

391 If the log Kow of the chemical is greater than the endpoint specific cut-offs

392 presented below, then no effects at saturation are expected for those endpoints.

393

394 Thiophenes:

395 ----------

396 Maximum LogKow: 5.0 (LC50)

397 Maximum LogKow: 6.4 (EC50)

398 Maximum LogKow: 8.0 (ChV)

399

400 Amides :

401 -------

402 Maximum LogKow: >8.5 (LC50)

403 Maximum LogKow: >8.0 (EC50,ChV)

404

405 Baseline Toxicity SAR Limitations:

406 ---------------------------------

407 Maximum LogKow: 5.0 (Fish 96-hr LC50; Daphnid LC50)

408 Maximum LogKow: 6.4 (Green Algae EC50)

409 Maximum LogKow: 8.0 (ChV)

410

411

412 ECOSAR Version 1.11 Results Page

413

414 SMILES : CCNc1nc(CC)c(s1)C(=O)NC(=O)c2cccs2

415 CHEM : LGC-32533

416 CAS Num: 

417 ChemID1: 

418 MOL FOR: C13 H15 N3 O2 S2 

419 MOL WT : 309.40

420 Log Kow: 1.986 (EPISuite Kowwin v1.68 Estimate)

421 Log Kow: (User Entered)

422 Log Kow: (PhysProp DB exp value - for comparison only)

423 Melt Pt: (User Entered for Wat Sol estimate)

424 Melt Pt: (deg C, PhysProp DB exp value for Wat Sol estimate)

425 Wat Sol: 218 (mg/L, EPISuite WSKowwin v1.43 Estimate)

426 Wat Sol: (User Entered)

427 Wat Sol: (PhysProp DB exp value)

428

429

430 --------------------------------------

431 Values used to Generate ECOSAR Profile

432 --------------------------------------

433 Log Kow: 1.986 (EPISuite Kowwin v1.68 Estimate)

434 Wat Sol: 218 (mg/L, EPISuite WSKowwin v1.43 Estimate)

435

436
-Page 64 of 68-

437

438 --------------------------------------

439 ECOSAR v1.11 Class-specific Estimations

440 --------------------------------------

441 Imides

442 Thiophenes

443 Predicted

444 ECOSAR Class Organism Duration End Pt mg/L (ppm)

445 =========================== ================== ======== ====== ==========

446 Imides : Fish 96-hr LC50 16.880

447 Imides : Daphnid 48-hr LC50 18.621

448 Imides : Green Algae 96-hr EC50 0.090

449 Imides : Fish ChV 3.483

450 Imides : Daphnid ChV 5.520

451 Imides : Green Algae ChV 0.015

452 Imides : Mysid 96-hr LC50 23.075

453

454 Thiophenes : Fish 96-hr LC50 53.329

455 Thiophenes : Daphnid 48-hr LC50 34.274

456 Thiophenes : Green Algae 96-hr EC50 70.157

457 Thiophenes : Fish ChV 4.423 !

458 Thiophenes : Daphnid ChV 3.455 !

459 Thiophenes : Green Algae ChV 48.490

460

461 =========================== ================== ======== ====== ==========

462 Neutral Organic SAR : Fish 96-hr LC50 261.853 *

463 (Baseline Toxicity) : Daphnid 48-hr LC50 148.484

464 : Green Algae 96-hr EC50 110.000

465 : Fish ChV 25.555

466 : Daphnid ChV 14.427

467 : Green Algae ChV 28.721

468

469 Note: * = asterisk designates: Chemical may not be soluble enough to

470 measure this predicted effect. If the effect level exceeds the

471 water solubility by 10X, typically no effects at saturation (NES)

472 are reported.

473

474 NOTE: ! = exclamation designates: The toxicity value was estimated through

475 application of acute-to-chronic ratios per methods outlined in

476 the ECOSAR Methodology Document provided in the ECOSAR Help Menu.

477

478

479 ------------------------------

480 Class Specific LogKow Cut-Offs

481 ------------------------------

482 If the log Kow of the chemical is greater than the endpoint specific cut-offs

483 presented below, then no effects at saturation are expected for those endpoints.

484

485 Imides:

486 ------

487 Maximum LogKow: 5.0 (LC50)

488 Maximum LogKow: 6.4 (EC50)

489 Maximum LogKow: 8.0 (ChV)

490

491 Thiophenes:

492 ----------

493 Maximum LogKow: 5.0 (LC50)

494 Maximum LogKow: 6.4 (EC50)

495 Maximum LogKow: 8.0 (ChV)

496

497 Baseline Toxicity SAR Limitations:

498 ---------------------------------
-Page 65 of 68-

499 Maximum LogKow: 5.0 (Fish 96-hr LC50; Daphnid LC50)

500 Maximum LogKow: 6.4 (Green Algae EC50)

501 Maximum LogKow: 8.0 (ChV)

502

503

504

505 ------------------------------------------------------------------------------

506

507 ECOSAR Version 1.11 Results Page

508

509 SMILES : CCNc1nc(CC)c(s1)C(=O)N=C(C(#N))c2cccs2

510 CHEM : LGC-32799

511 CAS Num: 

512 ChemID1: 

513 MOL FOR: C14 H14 N4 O1 S2 

514 MOL WT : 318.41

515 Log Kow: 4.648 (EPISuite Kowwin v1.68 Estimate)

516 Log Kow: (User Entered)

517 Log Kow: (PhysProp DB exp value - for comparison only)

518 Melt Pt: (User Entered for Wat Sol estimate)

519 Melt Pt: (deg C, PhysProp DB exp value for Wat Sol estimate)

520 Wat Sol: 1.027 (mg/L, EPISuite WSKowwin v1.43 Estimate)

521 Wat Sol: (User Entered)

522 Wat Sol: (PhysProp DB exp value)

523

524

525 --------------------------------------

526 Values used to Generate ECOSAR Profile

527 --------------------------------------

528 Log Kow: 4.648 (EPISuite Kowwin v1.68 Estimate)

529 Wat Sol: 1.027 (mg/L, EPISuite WSKowwin v1.43 Estimate)

530

531

532

533 --------------------------------------

534 ECOSAR v1.11 Class-specific Estimations

535 --------------------------------------

536 Thiophenes

537 Amides 

538 Predicted

539 ECOSAR Class Organism Duration End Pt mg/L (ppm)

540 =========================== ================== ======== ====== ==========

541 Thiophenes : Fish 96-hr LC50 0.832

542 Thiophenes : Daphnid 48-hr LC50 0.663

543 Thiophenes : Green Algae 96-hr EC50 0.713

544 Thiophenes : Fish ChV 0.054 !

545 Thiophenes : Daphnid ChV 0.069 !

546 Thiophenes : Green Algae ChV 0.981

547

548 Amides : Fish 96-hr LC50 1.216 *

549 Amides : Daphnid 48-hr LC50 0.395

550 Amides : Green Algae 96-hr EC50 0.068

551 Amides : Fish ChV 0.010

552 Amides : Daphnid ChV 0.127

553 Amides : Green Algae ChV 0.194

554 Amides : Fish (SW) 96-hr LC50 1.103 *

555 Amides : Mysid (SW) 96-hr LC50 0.161

556

557 =========================== ================== ======== ====== ==========

558 Neutral Organic SAR : Fish 96-hr LC50 1.095 *

559 (Baseline Toxicity) : Daphnid 48-hr LC50 0.794

560 : Green Algae 96-hr EC50 1.626 *
-Page 66 of 68-

561 : Fish ChV 0.143

562 : Daphnid ChV 0.153

563 : Green Algae ChV 0.734

564

565 Note: * = asterisk designates: Chemical may not be soluble enough to

566 measure this predicted effect. If the effect level exceeds the

567 water solubility by 10X, typically no effects at saturation (NES)

568 are reported.

569

570 NOTE: ! = exclamation designates: The toxicity value was estimated through

571 application of acute-to-chronic ratios per methods outlined in

572 the ECOSAR Methodology Document provided in the ECOSAR Help Menu.

573

574

575 ------------------------------

576 Class Specific LogKow Cut-Offs

577 ------------------------------

578 If the log Kow of the chemical is greater than the endpoint specific cut-offs

579 presented below, then no effects at saturation are expected for those endpoints.

580

581 Thiophenes:

582 ----------

583 Maximum LogKow: 5.0 (LC50)

584 Maximum LogKow: 6.4 (EC50)

585 Maximum LogKow: 8.0 (ChV)

586

587 Amides :

588 -------

589 Maximum LogKow: >8.5 (LC50)

590 Maximum LogKow: >8.0 (EC50,ChV)

591

592 Baseline Toxicity SAR Limitations:

593 ---------------------------------

594 Maximum LogKow: 5.0 (Fish 96-hr LC50; Daphnid LC50)

595 Maximum LogKow: 6.4 (Green Algae EC50)

596 Maximum LogKow: 8.0 (ChV)

597

598

599

600 ------------------------------------------------------------------------------

601

602 ECOSAR Version 1.11 Results Page

603

604 SMILES : CCC(=O)NC(C(#N))c2cccs2

605 CHEM : LGC 35525

606 CAS Num: 

607 ChemID1: 

608 MOL FOR: C9 H10 N2 O1 S1 

609 MOL WT : 194.25

610 Log Kow: 0.773 (EPISuite Kowwin v1.68 Estimate)

611 Log Kow: (User Entered)

612 Log Kow: (PhysProp DB exp value - for comparison only)

613 Melt Pt: (User Entered for Wat Sol estimate)

614 Melt Pt: (deg C, PhysProp DB exp value for Wat Sol estimate)

615 Wat Sol: 5559 (mg/L, EPISuite WSKowwin v1.43 Estimate)

616 Wat Sol: (User Entered)

617 Wat Sol: (PhysProp DB exp value)

618

619

620 --------------------------------------

621 Values used to Generate ECOSAR Profile

622 --------------------------------------
-Page 67 of 68-

623 Log Kow: 0.773 (EPISuite Kowwin v1.68 Estimate)

624 Wat Sol: 5559 (mg/L, EPISuite WSKowwin v1.43 Estimate)

625

626

627

628 --------------------------------------

629 ECOSAR v1.11 Class-specific Estimations

630 --------------------------------------

631 Thiophenes

632 Amides 

633 Benzyl Nitriles 

634 Predicted

635 ECOSAR Class Organism Duration End Pt mg/L (ppm)

636 =========================== ================== ======== ====== ==========

637 Thiophenes : Fish 96-hr LC50 225.584

638 Thiophenes : Daphnid 48-hr LC50 131.519

639 Thiophenes : Green Algae 96-hr EC50 360.820

640 Thiophenes : Fish ChV 20.974 !

641 Thiophenes : Daphnid ChV 13.064 !

642 Thiophenes : Green Algae ChV 182.268

643

644 Amides : Fish 96-hr LC50 437.546

645 Amides : Daphnid 48-hr LC50 847.863

646 Amides : Green Algae 96-hr EC50 10.560

647 Amides : Fish ChV 0.362

648 Amides : Daphnid ChV 21.158

649 Amides : Green Algae ChV 5.911

650 Amides : Fish (SW) 96-hr LC50 381.702

651 Amides : Mysid (SW) 96-hr LC50 16.392

652

653 Benzyl Nitriles : Fish 96-hr LC50 69.471

654 Benzyl Nitriles : Daphnid 48-hr LC50 3599.957

655 Benzyl Nitriles : Green Algae 96-hr EC50 11.693

656 Benzyl Nitriles : Fish ChV 19.327

657 Benzyl Nitriles : Daphnid ChV 7.790

658 Benzyl Nitriles : Green Algae ChV 5.697

659 Benzyl Nitriles : Fish (SW) 96-hr LC50 117.509

660 Benzyl Nitriles : Mysid (SW) 96-hr LC50 3.745

661

662 =========================== ================== ======== ====== ==========

663 Neutral Organic SAR : Fish 96-hr LC50 2017.651

664 (Baseline Toxicity) : Daphnid 48-hr LC50 1022.933

665 : Green Algae 96-hr EC50 477.010

666 : Fish ChV 172.549

667 : Daphnid ChV 72.782

668 : Green Algae ChV 97.066

669

670 Note: * = asterisk designates: Chemical may not be soluble enough to

671 measure this predicted effect. If the effect level exceeds the

672 water solubility by 10X, typically no effects at saturation (NES)

673 are reported.

674

675 NOTE: ! = exclamation designates: The toxicity value was estimated through

676 application of acute-to-chronic ratios per methods outlined in

677 the ECOSAR Methodology Document provided in the ECOSAR Help Menu.

678

679

680 ------------------------------

681 Class Specific LogKow Cut-Offs

682 ------------------------------

683 If the log Kow of the chemical is greater than the endpoint specific cut-offs

684 presented below, then no effects at saturation are expected for those endpoints.
-Page 68 of 68-

685

686 Thiophenes:

687 ----------

688 Maximum LogKow: 5.0 (LC50)

689 Maximum LogKow: 6.4 (EC50)

690 Maximum LogKow: 8.0 (ChV)

691

692 Amides :

693 -------

694 Maximum LogKow: >8.5 (LC50)

695 Maximum LogKow: >8.0 (EC50,ChV)

696

697 Benzyl Nitriles :

698 ----------------

699 Maximum LogKow: 5.0 (LC50)

700 Maximum LogKow: 6.4 (Green Algae EC50)

701 Maximum LogKow: 8.0 (Chronic Values)

702

703 Baseline Toxicity SAR Limitations:

704 ---------------------------------

705 Maximum LogKow: 5.0 (Fish 96-hr LC50; Daphnid LC50)

706 Maximum LogKow: 6.4 (Green Algae EC50)

707 Maximum LogKow: 8.0 (ChV)

708

709

710

711 ------------------------------------------------------------------------------

712

713

714 ------------------------------------------------------------------------------

715

716