Page 1 of 38 

### UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON D.C., 20460

MEMORANDUM Date 05/06 /201 5 Subject: Registration Review

– Preliminary Problem Formulation for Ecological

Risk and Environmental Fate, Endangered Species, and Drinking Water
As sessments for Cycloate PC Code : 041301 DP Barcode : 424436

To: Ma thew Manupella , Chemical Review Manager

Kevin Costello

, Branch Chief Risk Management and Implementation Branch 2 Pesticide Re

- evaluation Division ( PRD )

From: Christine Hartless

, Ph.D., Wildlife Biologist

James Lin , Ph.D., Environmental Engineer Environmental Risk Branch 2 Environmental Fate and Effects Division Office of Pesticide Programs

Reviewed: Gregory Orrick, Environmental Scientist

Jean Holmes, RAPL Environmental Risk Branch 2 Environmental Fate and Effects Division Office of Pesticide Programs

Through: Brian Anderson

, Branch Chief

Environmental Risk Branch 2 Environmental Fate and Effects Division Office of Pesticide Programs

The Environmental Fate and Effects Division (EFED) has completed the preliminary problem formulation (attached) for the ecological risk, environmental fate, endangered species

, and drinking water assessment s to be conducted as part of the registration r eview of the herbicide cycloate

.

The problem formulation draws on information from both open literature and studies submitted by the tec hnical registrants in response to data requirements. This document is intended to provide an overview of what is currently known regarding the environmental fate and ecological effects associated with cycloate and outlines uncertainties regardingPage 2 of 38



### attributes of the parent compound and its transformation products . It describes the preliminary ecological risk hypothesis and the processes that will be used during the completion of drinking water and ecological risk assessments in support of registrati on review

. This document also recommends studies that should be included in a data call

- in (DCI) to address uncertainties surrounding the environmental fate and potential ecolog ical effects of cycloate

.Page 3 of 38



# Preliminary Problem Formulation for the Environmental Fate and Ecological Risk , Endangered Species , a nd Drinking Water Assessment s in Support of

the R eg istration Review of Cycloate

N

- ethyl

- N

- cyclohexyl

- S

- ethylthiocarbamate

(CAS 1134

- 23

- 2 ) (PC Code 041301)

Environmental Risk Branch II Environmental Fate and Effects Division Christine Hartless, Ph.D., Wildlife Biologist James Lin, Ph.D. Environmental Engineer

Reviewed by: Gregory Orrick, Environmental Scientist Jean Holmes, DVM, RAPL Brian Anderson, Branch Chief U. S. Environmental Protection Agency Office of Pesticide Programs 1200 Pennsylvania Ave., NW Mail Code 7507P Washington, DC 20460Page 4 of 38 

### Table of Contents

1. Executive summary

................................ ................................ ................................ ........ 5 2. Introduction

................................ ................................ ................................ .................... 6 3. Use Char acterization

................................ ................................ ................................ ...... 6 4. Conclusions from Previous Risk Assessments

................................ .............................. 8 5. Environmental Fate and Transport

................................ ................................ ................ 10 6. Receptors

................................ ................................ ................................ ...................... 15 7. Exposure Pathways of Concern

................................ ................................ ................... 16 8. Analysis Plan

................................ ................................ ................................ ................ 17 8.1 Stressors of Concern

................................ ................................ ........................... 17 8.2 Measures of Exposure

................................ ................................ ........................ 17 8.3 Measures of Effect

................................ ................................ ............................. 18
9. En dangered Species Assessment

................................ ................................ ................. 18 10. Endocrine Disruptor Screening Program

................................ ............................... 18 11. Preliminary Identification of Data Gaps

................................ ................................ .... 18
11.1. Fate

................................ ................................ ................................ ...................... 18 11.2. Effects

................................ ................................ ................................ ................. 19 12. References

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

Appendix A. Ecotoxicity Data for Cycloate

................................ ................................ 34 Appendix B. Screening Level Models to Evaluate Potential Importance of Drinking Water and Inhalation Exposure Pathways

................................ ................................ .... 37Page 5 of 38



## 1. Executive summary

The Environmental Fate and Effects Division (EFED) has completed the preliminary problem formulation for the ecological risk, environmental fate, endangered species, and drinking water assessments to be conducted as part of the registration review of cycloate

. The problem formulation describes the methods pl anned to be used during the completion of drinking water and ecological risk assessments in support of registration review and provides an overview of the environmental fate, ecological effects, and potential risks associated with the use of cycloate as we ll as uncertainties unique to risk assessment of cycloate

. This document also identifies additional studies that would be beneficial to the conduct of an ecological risk assessment.

Data needs for ecological effects are:

 Mysid acute toxicity test (850.1 035)

 Fish acute toxicity test, marine (850.1075)

 Freshwater i nvertebrate life

- cycle test (850.1350)

 Freshwater fish early

- life stage test (850.1400 )

 Avian acute oral toxicity test (850.2100), one passerine species

 Avian inhalation , one species. Suggest to follow 870.1300 modified for birds or 885.1400 modified for a single exposure; p rotocol to be submitted to Agency for review prior to conduct of study.

 Avian reproduction toxicity test (850.2300), two species

 Acute oral toxicity to adult honey bees (Non

- gu ideline, OECD TG 213)

 Acute oral toxicity to larval honey bees (Non

- guideline, OECD TG 237)

 Chronic oral toxicity to larval honey bees (Non

- guideline)

 Chronic oral toxicity to adult honey bees (Non

- guideline)

 Field trial of residues in pollen and nectar (N on

- guideline)

 Semi

- field testing for pollinator (Non

- guideline, OECD Guidance 75)

 Field testing for pollinators (OCSPP Guideline 850.3040)

 Seedling emergence toxicity test (850.4100), 10 species

 Vegetative vigor toxicity test (850.4150), 10 species

 Aquatic plant toxicity test using Lemna spp. (850.4400)

 Algal toxicity test (850.4500), three species

 Cyanobacteria toxicity test (850.4550) Data needed for environmental fate and exposure assessment are:

 Photodegradation on soil (835.2410)

 Aerobic soil metabolism (with 3 additional soils) (835.4100)

 Aerobic aquatic metabolism (with 2 systems) (835.4400)

 (835.6100) ECM and ILV for Terrestrial Field Dissipation StudyPage 6 of 38



## 2 . Introduction

Cycloate (N

- ethyl

- N

- cyclohexyl

- S

- ethylthiocarbamate) is a member of th e (mono)thiocarbamate class of herbicides, which includes molinate, thiobencarb, vernolate, pebulate, butylate, triallate, diallate and EPTC. Cycloate is a systemic chemical that inhibits the shoot of emerging seedlings. It is most efficacious when the

c hemical is applied above the seeds so that the immature shoots grow up and reach the chemical. Cycloate is used as a pre

- emergent herbicide to control annual grasses, nutgrass, certain perennial grasses and many broadleaf weeds on sugar beets, spinach,

an d table beets.

Cycloate is required to be incorporated into the ground by ground equipment or by irrigation. It is used in irrigation from Center

- Pivot, Lateral Move, End Tow and Traveler irrigation systems. These irrigation systems contribute spray d rift to adjacent

non

- target areas.

The uses in the profile to be evaluated by EFED include sugar beet, garden beet, and spinach

. EFED evaluated the most recent ecological risk assessments for cycloate in association with the updated toxicity, exposure, an d usage information to determine if sufficient data are available and if further updates are needed to support registration review. In addition, EFED considered the latest Agency science policies and risk assessment methodologies. The structure of cycloa te , as well as the chemical names and other identifiers can be found in the chemical identity table in Section 5 of this document.



## 3. Use Characterization

T wo Section 3 labels (EPA Reg. Nos. 74530

- 16 and 73637

- 5) describe identical usage scenarios, application rates, and application methods ( Table 1) . In addition, there are seven Section 24C labels for use on either sugar beets or spinach ( Table 2 ). While all the Section 3 labels specify one application per growing season, some labeled crops can have multiple growing seasons per year. Sugar beets have one growing season per year, while table beets can have up to two growing seasons per year and spinach may have up to three growing seasons per year (EPA 2007, EPA 2012, EPA 2014)

. Maximum application r ates per year are needed on the labels for clarity. Currently, labels specify a maximum single application rate, but annual maximum rates are not specified. Any absence of information on the labels that specifies the maximum single application rate, the ap plication interval, the annual maximum rate allowed (lbs a.i./year), or application method may result in conservative assumptions.Page 7 of 38



### Table 1 . Methods and rates of application of currently registered uses of cycloate (EPA Reg. Nos . 74530

- 16 and 73637

- 5).

Crop Application

Timing Max. Single

App. Rate Application Restrictions

Sugar
Beets * - Preplant

- At Plant

- Immediately Post Planting 3 lbs a.i./acre on

sandy soils 4 lbs a.i./acre on heavier soils - No geographic restrictions

- One application per growing season.

- Use on mineral soils only.

- Use lower rate on sandy soils. Use higher rate on heavier soils.

- Late fall, prior to ground freeze 4 lbs a.i./acre - Recommended only in Idaho, Minnesota, Montana, North Dakota, Oregon, and Wyoming.

- For fall application, do not apply following spring.

Garden
Beets * - Preplant

- At Plant

- Immediately Post Planting 3 lbs a.i./acre on

sandy soils 4 lbs a.i./acre on heavier soils - No geographic restrictions

- One application per growing season.

- Use on mineral soils only.

- Use lower rate on sandy soils. Use higher rate on heavier soils.

Spinach * - Preplant

- At Plant

- Immediately Post Planting 3 lbs a.i./acre - Only use in Arkansas, Colorado, Connecticut, Delaware, Illinois, Maine, Maryland, Massachusetts, Mississippi, New Hampshire, New Jersey, New York, North Carolina, Ohio, Oklahoma, Pennsylvania, South Carolina, Texas, Vermont, Virginia, and western Tennessee

- One application per growing season.

- Use on sandy, mineral soils only.

4 lbs a.i./acre - Only use in California.

- One application per growing season.

- Use on sandy, mineral soils only.

* Applications methods include:

- Ground broadcast or band application with mechanical or sprinkler incorporation

- Soil injection

- Impregnation onto dry b ulk fertilizer followed by soil incorporationPage 8 of 38



### Table 2. Methods and rates of application of currently registered 24C (Special Local
Need , SLN ) uses of cycloate. *

Crop Reg. No. Application Timing Max. Single

App. Rate Application

Restrictions Application
Methods

Sugar
Beets ID 010015 Postemergence, after firs t true leaves have formed. 3

- 4 lbs a.i./acre

- For use in Idaho Broadcast or sprinkler. Incorporate mechanically or by irrigation.

OR 010022 Postemergence,

after first true leaves have formed. 3

- 4 lbs a.i./acre

- For use in Oregon Broadcast or sprinkler. Incorporate mechanically or by irrigation.

WA 010023 Postemergence,

after first true leaves have formed. 3 lbs a.i./acre - For use in Washington

- Do not apply after July 1 Broadcast and mechanical incorporation.

Spinach MI 080004 Preplant 3 lbs a.i./acre

- For use in Michigan Broadcast and mechanical incorporation.

OR 0 10023 Preplant 3 lbs a.i./acre

- For use in Oregon Broadcast and mechanical incorporation.

WA 010021 Preplant 3 lbs a.i./acre - For use in Washington Broadcast and mechanical incorporation.

Spinach for seed WA 020003 Preplant 3 lbs a.i./acre - For use in Washington Broadcast and mechanical incorporation.
* All SLNs have EPA Reg. No. 73637

- 5 as the master label.



## 4

. Conclusions from Previous Risk Assessments

The Agency has conducted previous ecologi cal risk assessments on cycloate that serve as a basis for this problem formulation. This is briefly summarized below. No endangered species assessments have been conducted for cycloate

.

At the time the EFED Reregistration Eligibility Decision (RED) Chapter was signed ( September 30, 2004)

, cycloate was registered as a pre

- emergent herbicide to control annual grasses, nutg rass, certain perennial grasses, and many broadleaf weeds for use on sugar beets, garden beets, and spinach. At the time of the RED, the maximum labeled r ate of application was 4 lbs a.i./acre nationwide and 6 lbs a.i./acre in California. Based on the avai lable fate and ecotoxicity data, the following conclusions were presented in the RED :

 No acute risks to terrestrial or aquatic animals were identified.

 Chronic risk to mammals was above concern levels

.

 Chronic risk to birds was presumed as avian reproduction data were not available.

 Chronic risk to aquatic organisms was unknown as no early life

- cycle or full life

cycle data for fish or aquatic invertebrates were available.Page 9 of 38



###  Risk to terrestrial and aquatic plants was presumed as no plant toxicity da ta were available.

 Potential risk to terrestrial and aquatic organisms from exposure to the major degradate, cycloate sulfoxid e is unknown. This degradate was listed as being of concern to the Health Effects Division.

 Certain application methods (Center

- P ivot, Lateral Move, End Tow, and Traveler irrigation systems) may encourage volatilization (from water or moist soils) and spray drift of cycloate to non

- target plants, thereby increasing the likelihood of risk to non

- target organisms.

 Cycloate’s environme ntal fate properties indicate moderate likelihood of movement off

- site into surface water or ground water. Volatilization may predominate in some situations. Although oxidation in air is believed to be rapid, the presumed degradate has an intact thiocarbamate moiety that may be biologically active.

 Cycloate persists in soil if incorporated into dry soil, but volatilizes rapidly from moist soil.

 The field dissipation half

- life is on the order of 10 to 40 days.

 The Tier 2 Drinking Water assessment d emonstrates that the expected drinking water concentrations (1 in 10 year average) will be 6.9 to 10 μg/L if cycloate is used at 4 lb a.i./acre.

Environmental fate and ecological effects data were in complete at the time the RED was finalized and a Data

- Call

- In (DCI) was issued to address the data gaps ( Table 3 ). None of these required studies have been submitted to the Agency

, and all data gaps are still outstanding

.

Table 3

. Environmental Fate and Ecotoxicity studies requested at the time o f finalization of the RED.
835.6100 Terrestrial Field Dissipation (including ECM and ILV)
850.1035 Mysid acute toxicity test
850.1075 Fish acute toxicity test, marine
850.1350 Invertebrate Life Cycle Test on TGAI
850.1400 Fish

- Early Life Stage on TGAI (estuarine/marine)
850.2300 Avian Reproduction

- Bobwhite Quail and Mallard Duck on TGAI

850.4100 Seedling Germination/Seedling Emergence, Tier 1 (10 most

sensitive species from testing with parent compound) on TEP

850.4150 Vegetative Vigor, Tier 1 (10 most sensitive species from testing

with parent compound) on TEP
850.4400 Aquatic Plant Growth, Tier 2 (five most sensitive species) on TEP

The most recent drinking water exposure assessment for use in the human dietary risk assessment was completed in 2006 (DP Barcode: D314010) . This assessment found that

an upper

- bound Tier 2 concentration of parent cycloate in surface water based on the California sugar beet scenario is 58 μg/L (acute), 5.0 μg/L (chronic), and 3.2 μg/L (cancer) for application throug h overhead sprinkler irrigation systems (modeled asPage 10 of 38



### aerial). An assessment of ground water exposure using SCIGROW performed for this assessment showed upper bound concentrations of cycloate in ground water we re no higher than 0.41 μg/ L.



## 5

. Environmental Fate and Transport

Registrant

- submitted data defining the physical, chemical, environmental fate and transport c haracteristics associated with cycloate are summarized in Table 4

. Cycloate has a moderate solubility (75 to 96 mg/L) and moderately high vapor pressure (6.2 x 10

- 3


### torr at 25 o 

### C). Henry’s Law constant is calculated as 1.85 x 10

- 5 

### atm∙m 3 

### /mol.

Table 4 . General physico

- chemical and environmental fate properties of c ycl oate

.

Parameter Value Reference

Selected Physical/Chemical Parameters

Molecular Mass 21 5.4 g / mol calculated

Water Solubility 7 5

- 95 mg / L RED

Vapor pressure 6.2 x 10

- 3 torr at 25 o C RED

Density 1.0 239 kg / L @ 20 o C RED

Henry's Law Constant 1.8 5 x 10

- 5 atm∙m 3 / mol RED

Hydrolysis t 1/2 no evidence of degradation at pH 5, 7, and 9 MRID 00257865

Aqueous Photolysis t 1⁄2 219 d ays MRID 00257865

Soil Photo degradation t 1⁄2 7.63 days MRID 00265256

Aerobic Soil metabolism t 1⁄2 43 days MRID 00162644, 00264619, 41582403

Anaerobic Soil metabolism t 1⁄2 68 days MRID 00 266125

Anaerobic Aquatic t 1⁄2 192 days MRID 42997901

Photo

- degradation i n Air t 1⁄2 5.2 hours MRID 42541101

Terrestrial Field Dissipation t 1⁄2 10 days in top 6 in. of soil (FL) 22 days and 40 days in top 12 in. of soil (MS ) 11 days in top 3 in. of soil (CA) MRID 00254904

Adsorption/Desorption K ads : 9.0 (silt loam); 10.0 (loam), 2.18 (sandy loam), and 8.13 (clay) mL/g . Koc 500

– 678 ml/g Kdes: 11.5 (silt loam), 12.3 (loam), 2.98 (sandy loam), and 9.63 (clay) mL/g

. MRID 41920603Page 11 of 38



### Table 4 . General physico

- chemical and environmental fate properties of c ycl oate

.

Parameter Value Reference

Fish Bioaccumulation After 7 days of exposure, total cycloate residues accumulated in bluegill sunfish with max. BCF of 82x, 670x, and 330x in edible tissues, i nedible tissues, and whole fish, respectively. After 3 days of depuration, the rate s of depuration were 81%, 93% and 88%, respectively for edible tissues, i nedible tissues, and whole fish. MRID 41920601



### Cycloate is stable to hydrolysis and nearly stable to photolysis in water. A literatu re study (MRID 42541101) indicates that volatilized cycloate may have a short lifetime in air (5.2 hours) due to reaction with hydroxyl radicals. Therefore, non

- target organisms are not expected to be exposed to cycloate via spray drift or volatility for s everal days after application.

Soil photodegradation study in laboratory showed a half

- life of 7.63 days. Laboratory metabolism studies yielded half

- lives of 43 days (aerobic soil), 68 days (anaerobic soil), and 192 days (anaerobic aquatic metabolism). The terrestrial field dissipation stud ies

, yielded a half

- life of 11 days in the upper 3 inches with a California soil; a half

- life of 10 days in the top 6 inches with a Florida soil; and two half

- life values of 22 days and 40 days in the top 12 inches wi th Mississippi soils . Cycloate degradates in soil include the sulfoxide (which may revert to the parent under reducing conditions) and N

ethylcyclohexylamine. Two sets of ring

- hydroxy and ring

- keto degradates (the 4

- hydroxy

- , 4

- keto

- , 3

- hydroxy

- and 3

- k eto

- degradates) are also formed in laboratory studies. Other degradates seen in laboratory studies include N

- cyclohexyl

- N

ethylformamide and N

- ethyl

- N

- formyl

- S

- ethyl thiocarbamate.

Laboratory studies show that cycloate tends to sorb to soil under dry conditions, and that the sorption is not reversed if the soil is later flooded. However, if the soil is already flooded at the time of application, cycloate is easily desorbed and then volatilized over time. K oc 

### values (500 to 678 mL/g) indicate that cycloate is moderately mobile in soil. A fish BCF study indicates that cycloate bioconcentrates in fish by 330x.

In summary, cycloate applied to dry soil and immediately incorporated tends to remain sorbed to the soil, and dissipates with a half

- life on the order of one to two months. Cycloate volatilizes from moist soil if not immediately incorporated. Overall, the major dissipation route for cycloate in the environment is v olatiliz ation followed by atmospheric oxidation

.

The environmental transformation products of cycloate with molecular structure are tabulated in Table 5

.Page 12 of 38



### Table 5

. Cycloate and Its Environmental Transformation Products Code Name/ Synonym
Chemical Name Chemical Stru cture Study Type MRID Maximum %AR (day) Final %AR

(study length)

PARENT 

### Cycloate

N

- ethyl

- N

- cyclohexyl

- S

- ethylthiocarbamate

CAS Reg. No. 1134

- 23

- 2

Formula: C 11 H 21 NOS MW: 215.4 g/mol

TRANSFORMATION PRODUCTS 

### FOR

N

- cyclohexyl

- N

- ethylformamide

Formula: C 17 H 29 NO 3 S
MW: 281 g/mol Anaerobic Aquatic
Metabolism 42997901 0.68% (181 day) 0.13% (365 day)

Soil Photodegradation 00265256 2.2% (192 hr) 2.2% (192 hr)



### 3HC

S

- ethyl N

- ethyl

- N

- (cis/trans

- 3

- hydroxycyclohexyl)carbamothioate

Formula: C 1 5 H 2 5 NO 2 S
MW: 283 g/mol Anaerobic Aquatic
Metabolism 42997901 0.33% (90 day)

-- (365 day)Page 13 of 38



### Code Name/ Synonym
Chemical Name Chemical Stru cture Study Type MRID Maximum %AR (day) Final %AR

(study length)

4

- KC

S

- ethyl N

- ethyl

- N

- (4

- oxo

- cyclohexyl)carbamothioate
Formula: C 17 H 29 NO 4 S MW: 343 g/mol Anaerobic Aquatic
Metabolism 42997901 0.23% (181 day) 0.1% (365 day)



### ECA

N

- ethylcyclohexylamine

Formula: C 1 5 H 2 5 NO 2 S
MW: 283 g/mol Anaerobic Aquatic Metabolism 42997901 0.63% (269 day) 0.3% (365 day)

Soil Photodegradation 00265256 17.3% (192 hr) 17.3% (192 hr)

Aerobic Soil
Metabolism 41582403 7.3% (38 day) 3% (120 day)



### 4

- HC

S

- ethyl N

- ethyl

- N

- (cis/trans

- 4

- hydroxycyclohexyl)carbamothioate

Formula: C 1 5 H 2 5 NO 2 S MW: 283 g/mol Anaerobic Aquatic Metabolism 42997901 0.235 (181 day) 0.1% (365 day)



### 3

- KC

S

- ethyl N

- ethyl

- N

- (3

- oxo

- cyclohexyl)carbamothioate

Formula: C 1 5 H 2 5 NO 2 S MW: 283 g/mol Anaerobic Aquatic Metabolism 42997901 0.13% (181 day)

-- (365 day)Page 14 of 38



### Code Name/ Synonym
Chemical Name Chemical Stru cture Study Type MRID Maximum %AR (day) Final %AR

(study length) Cycloate Sulfoxide

Formula: C 1 5 H 2 5 NO 2 S
MW: 283 g/mol Aerobic Soil Metabolism 162644

264619 16% (31 day) 1% (120 day)

Soil Photodegradation 00265256 6.5% (60 hr) 4.9% (192 hr)



### Cycloate Sulfone

Formula: C 1 5 H 2 5 NO 2 S MW: 283 g/mol Soil Photodegradation 00265256 2.5% (60 hr) 1.4% (192 hr)



### Cyclohexylamine

Formula: C 1 5 H 2 5 NO 2 S
MW: 283 g/mol
Soil Photodegradation 00265256 2.6% (120 hr) 2.2% (192 hr)Page 15 of 38



## 6

. Receptors

Table 6 provides a summary of the taxonomic groups and the surrogate species tested to characterize the potential acute and chronic ec ological effects of cycloate

. In addition, the table provides a preliminary overview of the potential acute toxicity of cycloate by providing the acute toxicity classifications. No ecotoxicity data are available for any degradates of cycloate

.

Cycloate is practically non

- toxic to bird s on an acute oral basis, practically non

- toxic to birds on a subacute dietary exposure basis, slightly toxic to mammals on an acute oral exposure basis , and practical ly non

- toxic to honey bees on a contact basis . Data on the toxicity of cycloate to terres trial plants have not been submitted to the Agency.

Technical grade cycloate is classified as moderately toxic to freshwater fish and as moderately toxic to slightly toxic to aquatic invertebrates on an acute exposure basis. Acute estuarine/marine fish and invertebrate data as well as c hronic exposure effect data

to cycloate for fish and invertebrates have not been submitted to the Agency. In addition, no toxicity data for aquatic plant studies have been submitted to the Agency.

A review of the Ecologi cal Incident Information System (EIIS, version 2.1) and the Avian Monitoring Information System (AIMS) was completed on August 7, 2014 , and no ecological incidents involving cycloate or cycloate sulfate were identified. Incident databases will be reviewed again at the time of the risk assessment.

Table 6 . Test Species Evaluated for Assessing Potential Ecological Effects of Cycloate

.

Taxonomic Group Study Type Tested Species Toxicity Endpoint Acute Toxicity Classification / NOAEC most sensitive endpoint ( s ) Source MRID

Birds 1 Acute oral Bobwhite quail (Colinus virginianus) LD 50 >2150 mg a.i./kg

- bw Practically non

- toxic Acc# 072166

Dietary B obwhite quail LC 50 >5620 mg a.i./kg

- diet Practically non

- toxic 00145554

Chronic No data

Mammals Acute oral Laboratory rat ( Rattus norvegicus ) LD 50 = 2275 mg a.i./kg

- bw Slightly toxic 00132790

Chronic Laboratory rat NOAEC = 8 mg a.i./kg/day LOAEC = 25 mg a.i./kg/day decreased weight, decreased pup survival (72 mg a.i. /kg/day) 00132795

Terrestrial invertebrates Acute

contact Honey bee

( Apis mellifera ) LD 50 = 29 μg a.i./bee Practically non

- toxic 00036935

Freshwater fish 2 Acute Rainbow trout Oncorhynchus mykiss LC 50 = 4.5 mg a.i./L Moderately toxic Acc# 090620Page 16 of 38



### Table 6 . Test Species Evaluated for Assessing Potential Ecological Effects of Cycloate

.

Taxonomic Group Study Type Tested Species Toxicity Endpoint Acute Toxicity Classification / NOAEC most sensitive endpoint ( s ) Source MRID

Chronic No data

Freshwater invertebrates Acute Waterflea Daphnia magna EC 50 = 24 mg a.i./L Slightly toxic 00143655

Chronic No data

Estuarine/ marine fish Acute and

Chronic No data

Estuarine/
marine invertebrates Acute and

Chronic No data

Terrestrial plants Seedling

emergence No data

Vegetative vigor No data

Aquatic plants and algae Vascular No data

Non

vascular No data

1 Birds represent surrogates for terrestrial

- phase amphibians and reptiles.

2 Freshwater fish are used as surrogates for aquatic

- phase amphibians.



## 7

. Exposure Pathways of Concern

The environmental fate properties and use patterns of cycloate indicate that drift, runoff

, leaching to ground water

, and movement through the affected plants represent potential transport mechanisms of cycloate to aquatic and terrestrial organisms.

Drinking water and inhalation exposure pathways were screened using the SIP (Screening Imbibition Program) and STIR (Screening Tool for Inhalation Risk) screenin g methods SIP and STIR are described in detail at: http://www.epa.gov/oppefed1/models/terrestrial/index.htm

. The drinking water pathway was found to be an exposure pathway of potent ial concern for chronic risks to mammals

. Chronic risk to birds through the drinking water exposure pathway could not be assessed as no reproduction toxicity data were available for birds. The inhalation exposure pathway was found to be an exposure pathway of concern for birds due to the high volatility of cycloate. SIP and STIR results are presented in Appendix B

.Page 17 of 38



## 8

. Analysis Plan

8.1 Stressors of Concern

i. Ecological Risk

The stressor of ecological concern for terrestrial and aquatic organisms is parent cycloate

. The 2003 Metabolism Assessment Review Committee (MARC) memo (DPbarcode D295670) listed several degradates of concern for residues in rotational crops and in livestock. No degr adates were identified as residues of concern in drinking water. Of those degradates identified residues of concern in rotational crops and livestock, none were observed as major degradates in any of the reviewed environment fate studies. Since the likelih ood that the identified HED degradates of concern will be found in soil and water matrices is low , the EFED ecological risk assessment will only consider parent cycloate.

ii. Drinking Water

A new drinking water assessment will be conducted using t he up

- to

- date modeling tools of SWCC (Surface Water Concentration Calculator) and PRZM

- GW (Pesticide Root Zone Model

– Ground Water) , and any new submitted e

- fate data according to current OPP guidance for drinking water exposure assessment. A ccording to a 2003 MAR C

memo (DPbarcode D295670) , the residue of concern for drinking water is cycloate parent compound only

.



## 8.2 Measures of Exposure

i. Ecological Exposure

EFED will use standard available models to evaluate potential exposures to aquatic and terrestrial organisms as described at http://www.epa.gov/pesticides/science/models_db.htm

. As cycloa te is a systemic chemical, exposure to terrestrial organisms may occur when feeding on plants containing cycloate residues. Magnitude of residue data reviewed by HED will be used as screening level estimates of cycloate concentrations in various plant comp onents.

Screening level calculations suggest that the drinking water pathway may be significant in causing chronic effects to terrestrial organisms . In addition, screening level calculations indicate that inhalation of cycloate in vapor phase may result in exposures that may cause toxic effects. These exposure pathway s may be further considered at the time of the risk assessment ( Appendix B ).

The Agency is aware of monitoring conducted by federal and state agencies . These data will be considered in the assessment to the ex tent that they are available.Page 18 of 38 

## 8.3 Measures of Effect

Toxicity data presented in Section 6 of this problem formulation will be used to calculate risk quotients. Any additional information submitt ed by the registrant or found in the open literature prior to conduct of the risk assessment will also be considered. The open literature studies are identified using EPA’s ECOTOXicology database ( ECOTOX) (USEPA, 2007 c ), which employs a literature search engine for locating chemical toxicity data for aquatic life, terrestrial plants, and wildlife. The evaluation of both sources of data can also provide insight into the direct and indirect effects of pesticides on biotic communities from loss of species th at are sensitive to the chemicals and from changes in structure and functional characteristics of the affected communities.



## 9. Endangered Species Assessment

Consistent with the Agency’s responsibility under the Endangered Species Act (ESA), the Agency w ill evaluate risks to federally threatened and/or endangered (listed) species from registered uses of pesticides in registration review . The process for evaluating potential risks to listed species is further described at http://www.epa.gov/oppfead1/endanger/litstatus/riskasses.htm

.


## 10

. Endocrine Disruptor Screening Program

Cycloate was not included in the first group or the second group of chemicals issued an order to conduct Tier 1 EDSP testing. For additional information the EDSP program, visit http://www.epa.gov/endo/

.


## 11

. Preliminary Identification of Data Gaps

1 1. 1. Fate

The environmental fate data base for cycloate is not complete ( Table 7 ). The following studies are data gaps : (1) soil photodegradation study , (2) aerobic soil metabolism study (with 3 additional soil types), (3) aerobic aquatic metabolism study (with 2 systems), and (4) Environmental Chemistry Method (ECM) and Independent Laboratory Validation (ILV) for the t errestrial field dissipation study.Page 19 of 38



### Table 7. Available environmental fate data for cycloate and remaining data gaps.

158 Guideline (OPPTS) Description MRI D Classification Data Gap? C omments

835.1240 (163

- 1) Adsorption/Desorption MRID 41920603 acceptable no data requirement satisfied

835.1410 (163

- 2) Laboratory Volatility MRID 41920602 acceptable no data requirement satisfied

835.2120 (161

- 1) Hydrolysis MRID 00 2 57865 acceptable no data requirement satisfied

835.2240 (161

- 2) Photodegradation in water MRID 00 257865 acceptable no data requirement satisfied

835.2410 (161

- 3) Photodegradation on soil MRID 00265256 unacceptable yes data requirement not satisfied ; chemigation is allowed on the label ; additional data are needed

835.2370 (161

- 4 ) Photodegradation in air MRID 42541101 acceptable no data requirement satisfied

835.4100 (162

- 1) Aerobic soil metabolism MRID 00 162644 MRID 00264619 MRID 41582403 acceptable yes data requirement not satisfied ; data on 3 additional soils are needed

835.4200 (162

- 2) Anaerobic soil metabolism MRID 00266125 acceptable no data requirement satisfied

835.43 00 (162

- 4 ) A erobic Aquatic Metabolism (none) (not applicable) yes a study of 2 systems is needed

835.4400 (162

- 3) Anaerobic Aquatic

Metabolism MRID 42997901 acceptable no data requirement not satisfied ; but additional data are not needed

835.6100 (164

- 1) Terrestrial Field Dissipation MRID 41920603 supplemental no additional TFD study is not required

850.1730 (165

- 4) Fish Bioconcentration Factor MRID 41920601 acceptable no data requirement satisfied

850.6100 Environmental Chemistry

Method: Soil and water none NA yes needed to support potential monitoring

850.6100 Independent Laboratory

Validation: Soil and water none NA yes needed to support potential monitoring



## 11. 2. Effects

Tables 8 and 9 identify ecological effects studies by MRID that offer data for each guideline requirement, as well as study classifications and whether or not further data are needed in order to support risk assessment.

Although cycloate is categorized as practically non

- toxic to adult honeybees on contact exposure basis, and by extension, to other beneficial terrestrial invertebrates on an acute exposure basis, there is considerable uncertainty regarding the potential ef fects of the compound on honeybee larval development and survival as well as potential for chronic effects. Therefore, additional data on pollinators is needed to fully characterize the risk associated with cycloate use to all developmental stages of hone ybees, as sensitivity may vary according to life

- stage and length of exposure (adult vs. larval and acute vs. chronic,Page 20 of 38



### respectively). Additional information is needed, but uncertainty associated with risks to honey bees need to be evaluated with more data to different life stages. Cycloate is systemic in plants so exposure via pollen and nectar is possible; and therefore, residues of pollen and nectar of crops are an additional data need. Open literature data is needed to help better characterize some un certainties regarding potential effects to bees and other

non

- target terrestrial invertebrates. In addition, higher tier effects toxicity tests ( i.e., semi

- field and/or field studies

– Tier II and Tier III, respectively) may be needed, based on the result s of the larval and chronic adult toxicity studies. Higher tier studies are recommended if the ratio of the EEC and larval or adult bee acute LD50> 0.4 or the ratio of the EEC and the chronic NOAEC> 1 . Incident data and/or compelling open literature studies can also be used to support the need for higher tier studies. Should the screening level risk assessment identify that there are risk concerns to bees, mitigation measures may need to be considered or the registrant may need to conduct Tier II or Tier III effects studies ( e.g. OECD Guideline 75 and/or 850.3040 guideline studies) that reduce uncertainty by characterizing cycloate’s e ffects at the whole

- colony level ( http://www2.epa.gov/pollinator

- protection/pollinator

- risk

- assessment

- guidance )

. These additional pollinator protection studies are listed in Table 8

.

Table 8. Available ecological effects data for terrestrial organisms exposed to cycloate and remainin g data gaps.

OCSPP Guideline Data Requirement Submitted Studies (MRID) Study

Classifications Are data needed for risk assessment? Current Additional Data Need

850.2100 Avian oral toxicity Acc# 072166 Acceptable Yes
Data are required for a vian acute oral with passerine Acc# 073005 Invalid

Acc# 073005 Invalid

850.2200 Avian dietary toxicity 00145554 Acceptable No

--
Acc#072166 Supplemental

Acc#072166 Supplemental

42090306 Acceptable

850.2300 Avian reproduction (None) (N/A) Yes Data have not been submitted to fulfill this guideline. Data are required for both an upland game bird and a water fowl species.

Non

- guideline Avian inhalation (None) (N/A) Yes A data gap was identified as inhalation concerns were raised based on the STIR screen.

850.3020 Honey bee acute

contact toxicity 00036935 Acceptable No

850.3030 Honey bee residue on

foliage (None) (N/A) No Data are not requested at this time as the adult bee contact
LD 50 was greater than 11 μg a.i./bee.Page 21 of 38



### Table 8. Available ecological effects data for terrestrial organisms exposed to cycloate and remainin g data gaps.

OCSPP Guideline Data Requirement Submitted Studies (MRID) Study

Classifications Are data needed for risk assessment? Current Additional Data Need

Non

- guideline, OECD TG 213 Acute oral toxicity to

adult honey bees (None) (N/A) Yes Recommend that PRD request data per: http://www2.epa.gov/pollinator

protection/pollinator

- risk

assessment

- guidance

Non

- guideline, OECD TG 237 Acute oral toxicity to

larval honey bees (None) (N/A) Yes Recommend that PRD request data per: http://www2.epa.gov/pollinator

protection/pollinator

- risk

assessment

- guidance

Non

- guideline Chronic oral toxicity

to adult honey bees (None) (N/A) Yes Recommend that PRD request data per: http://www2.epa.gov/pollinator

protection/pollinator

- risk

assessment

- guidance

Non

- guideline Chronic oral toxicity

to larval honey bees (None) (N/A) Yes Recommend that PRD request data per: http://www2.epa.gov/pollinator

protection/pollinator

- risk

assessment

- guidance

Non

- guideline Field trial of residues

in pollen and nectar (None) (N/A) Yes Recommend that PRD request data per: http://www2.epa.gov/pollinator

protection/pollinator

- risk

assessment

- guidance

Non

- guideli ne, OECD Guidance 75 Semi

- field testing for

pollinator (None) (N/A) Yes Recommend that PRD request data per: http://www2.epa.gov/pollinator

protection/pollinator

- risk

assessment

- guidance

850.3040 Field testing for

pollinator (None) (N/A) Yes Recommend that PRD request data per: http://www2.epa.gov/pollinator

protection/pollinator

- risk

assessment

- guidance

850.3100 Earthworm

Subchronic Toxicity
Test (None) (N/A) No Data have not been submitted to fulfill this guideline. A data gap was not identified as these data

are not necessary for risk assessment at this time.

850.4100 Seedling Emergence

and Seedling Growth (None) (N/A) Yes Data have not been submitted to fulfill this guideline. Data are required for 10 species.

850.4150 Vegetative Vigor (None) (N/A) Yes Data have not been submitted to fulfill this guideline. Data are required for 10 species.Page 22 of 38



### Table 9. Available ecological effects data for aquatic organisms exposed to cycloate and remaining data gaps.

OCSPP Guideline Data

Requirement Submitted

Studies (MRID) Study

Classifications Are data

needed to conduct risk assessment? Current Additional Data Need

850.1010 Freshwater

invertebrate acute toxicity 00143655 Acceptable No

--

05001497 Supplemental

850.1025
850.1035 850.1045 850.1055 Saltwater

invertebrate acute toxicity (None) (N/A) Yes Data have not been submitted to fulfill this guideline.

850.1075 Freshwater fish

acute toxicity 41614703 Acceptable No

--

Acc# 090620 Acceptable

Acc# 090620 Acceptable

45608401 Acceptable

45608401 Acceptable

45608401 Acceptable

Acc# 072166 supplemental

00143654 Acceptable

00084743 supplemental

850.1075 Saltwater fish

acute toxicity (None) (N/A) Yes Data have not been submitted to fulfill this guideline.

850.1300 Freshwater

invertebrate life cycle (None) (N/A) Yes Data have not been submitted to fulfill this guideline.

850.1350 Saltwater

invertebrates life cycle (None) (N/A) No Data have not been submitted to fulfill this guideline. A data gap was not identified as these data are not necessary for risk assessment at this time.

850.1400 Freshwater fish

early

- life stage (None) (N/A) Yes Data have not been submitted to fulfill this guideline.

850.1400 Saltwater fish

early

- life stage (None) (N/A) No Data have not been submitted to fulfill this guideline. A data gap was not identified as these data are not necessary for risk assessment at this time.

850.1500 Fish life cycle (None) (N/A) No Data have not been submitted to fulfill this guideline. A data gap was not identified as these data are not necessary for risk assessment at this time.

850.4400 Aquatic plant

Toxicity Test using Lemna

spp. (None) (N/A) Yes Data have not been submitted to fulfill this guideline.Page 23 of 38



### Table 9. Available ecological effects data for aquatic organisms exposed to cycloate and remaining data gaps.

OCSPP Guideline Data

Requirement Submitted

Studies (MRID) Study

Classifications Are data

needed to conduct risk assessment? Current Additional Data Need

850.4500 Algal toxicity (None) (N/A) Yes Data have not been submitted to fulfill this guideline. Data are required for three species.

850.4550 Cyanobacteria (None) (N/A) Yes Data have not been submitted to fulfill this guideline.Page 24 of 38



## 12

. References

Internal Office of Pesticide Program Documents

US EPA 2007. Maximum Number of Crop Cycles Per Year in California for Methomyl Use Sites. Memorandum from Monisha Kaul (Biological Economic and Analysis Division, BEAD) to Melissa Panger (Environmental Fate and Effects Division, EFED). Signed February 28, 2007.

US EPA 2012. Usage Metrics for Row Crops Estimated from Survey Data. Memorandum from Jonathan Becker in Biological Economic and Analysis Division (BEAD). Signed July 31, 2012. 136 pages.

US EPA 2014. Guidance on Usage Data Available for 19 Field Crops (Version 1). Memorandum from Don Brady (Division Director) to Environmental Fate and Effects Division Staff. Signed June 11, 2014. 11 pages.



### Environmental F

ate Data Submitted To Support Registration

Guideline: 161

- 1 Hydrolysis

------------------------------------------------------------------------------------- MRID: 132550 Stauffer Chemical Co. (1983) ?Residue of Ro

- Neet in Corn; Environ

- mental Fate Data|. (Compilation; unpublished study received Nov 30, 1983 under 476

- EX

- 106; CDL:072167

- A; 072168)

MRID: 149662 Myers, H.; Bartell, L. (1983) Hydrolysis Studies of Cycloate: Report No. WRC 83

- 73. Unpublished report prepared by Stauffer Chemical Com pany. 17 p.

MRID: 92025018 Calderbank, A. (1990) ICI Americas Inc. Phase 3 Summary of MRID 00149662. Hydrolysis Studies of Cyloate (sic): Report No. WRC

- 83

- 73. Prepared by STAUFFER CHEMICAL COMPANY. 11 p.

Guideline: 161

- 2 Photodegradation

- water

------------------------------------------------------------------------------------- MRID: 148882 Myers, H.; Bartell, L. (1985) Photolysis Study of Cycloate: Report No. 85

- 22. Unpublished report prepared by Stauffer Chemical Compa ny. 8 p.

MRID: 42249701 Hillebrecht, W. (1992) Addendum Number 1 to MRID 148882: Cycloate Photodegradation in Water: Lab Project Number: WRH

- 1/92. Unpublished study prepared by ICI Americas, Inc. 24 p.

MRID: 92025019 Calderbank, A. (1990) ICI Ameri cas Inc. Phase 3 Summary of MRID 00148882.Page 25 of 38



### Photolysis Study of Cycloate; Procedures for Determining the Hydrolytic and Photolytic Degradation Rates of Pesticides: Report Nos. RRC

- 85

- 22; RRC 84

- 50. Prepared by STAUFFER CHEMICAL COMPANY. 13 p.

Guideline: 161

- 3 Photodegradation

- soil

------------------------------------------------------------------------------------- MRID: 93485 Gray, R.A.; Weierich, A.J. (1965?) Behavior and Persistence of S

- Ethyl Cyclohexylethylthiocarbamate (R

- 2063) in Soils. ( Unpublished study received Feb 14, 1967 under 7F0522; submitted by Stauffer Chemical Co., Richmond, Calif.; CDL:090621

- F)

MRID: 108333 Gray, R.; Weierich, A. (1968) Behavior and Persistence of Thio

- carbamate Herbicides in Soils under Different Environm ental Conditions. (Unpublished study received Nov 4, 1971 under 1F1042; submitted by Stauffer Chemical Co., Richmond, CA; CDL: 091932

- H)

MRID: 117144 Gray, R.; Weierich, A. (1965) Persistence of Ro

- Neet in Soils. (Unpublished study received Nov 29, 19 65 under unknown admin. no.; submitted by Stauffer Chemical Co., Richmond, CA; CDL: 123664

- C)

MRID: 131466 Gray, R.; Murphy, J. (19??) Breakdown Products of S

- Ethyl Cyclo

hexylethylthiocarbamate (Ro

- Neet) in Soils and in Microbial Cultures. (Unpublish ed study received Oct 7, 1983 under 476

- 1978; submitted by Stauffer Chemical Co., Richmond, CA; CDL:251456

- D)

MRID: 163864 Tarr, J. (1986) Photodegradation of [Ring(U)

- [carbon 14]]Cycloate on Soil: Lab Project
ID: PMS

- 198; MRC

- 86

- 12. Unpublished study prepared by Stauffer Chemical Co., Mountain View Research Cen

- ter. 40 p.

MRID: 92025020 Calderbank, A. (1990) ICI Americas Inc. Phase 3 Summary of MRID 00163864. Photodegradation of [Ring (u)

- Carbon

- 14] Cycloate on Soil: Report No. MRC

- 86

- 12; Study No. PMS

- 198. Prepared by Stauffer Chemical Co. 18 p.

Guideline: 161

- 4 Photodegradatio n

- air

------------------------------------------------------------------------------------- MRID: 42541101 Kwok, E.; Atkinson, R.; Arey, J. (1992) Gas

- phase atmospheric chemistry of selected Thiocarbamates. Environ. Sci. Technol. 26(9):1798

- 1807.Page 26 of 38



### Guide line: 162

- 1 Aerobic soil metabolism

------------------------------------------------------------------------------------- MRID: 93485 Gray, R.A.; Weierich, A.J. (1965?) Behavior and Persistence of S

- Ethyl Cyclohexylethylthiocarbamate (R

- 2063) in So ils. (Unpub

- lished study received Feb 14, 1967 under 7F0522; submitted by Stauffer Chemical Co., Richmond, Calif.; CDL:090621

- F)

MRID: 117144 Gray, R.; Weierich, A. (1965) Persistence of Ro

- Neet in Soils. (Unpublished study received Nov 29, 1965 under unknown admin. no.; submitted by Stauffer Chemical Co., Richmond, CA; CDL: 123664

- C)

MRID: 131466 Gray, R.; Murphy, J. (19??) Breakdown Products of S

- Ethyl Cyclo

hexylethylthiocarbamate (Ro

- Neet) in Soils and in Microbial Cultures. (Unpublished study received Oct 7, 1983 under 476

- 1978; submitted by Stauffer Chemical Co., Richmond, CA; CDL:251456

- D)

MRID: 131467 Antognini, J.; Gray, R.; Menn, J. (1970) Chemical, physical, toxicological and biochemical properties of cycloate. Pages 293

- 299, In Pro ceedings, Second International Meeting on Selective Weed Control in Beet Crops: Vol. 1. ?S.l.: s.n|. (Also In un

published submission received Oct 7, 1983 under 476

- 1978; sub

- mitted by Stauffer Chemical Co., Richmond, CA; CDL:251456

- E)

MRID: 162644 Spillner, C. (1986) Ro

- neet Aerobic Soil Metabolism Study: Laboratory Project ID:
PMS

- 177: MRC

- 86

- 07. Unpublished study pre

- pared by Stauffer Chemical Co., Mountain View Research Center. 71 p.

MRID: 162956 Spillner, C. (1986) Aerobic Soil Metabolism Study [with] Ro

- Neet: Interim Report 1:
PMS

- 177: Project No. 148217. Unpublished study prepared by Stauffer Chemical Co., Mountain View Research Center in cooperation with Analytical Development Corp. 33

p.

MRID: 41582403 Spillner, C. (1989) Identification of Cycloate Soil Metabolites: Aerobic Soil Metabolism: Lab Project Number: PMS

- 306: RR 89

- 063B. Unpublished study prepared by ICI Americas Inc. 56 p.

MRID: 92025021 Calderbank, A. (1990) ICI Americas Inc. Phase 3 Summ ary of MRID 00162644. Ro

Neet Aerobic Soil Metabolism Study: Report No. MRC 86

- 07; Study No. PMS

- 177. Prepared by Stauffer Chemical Company. 20 p.Page 27 of 38



### Guideline: 162

- 2 Anaerobic soil metabolism

------------------------------------------------------- ------------------------------ MRID: 162652 Spillner, C. (1986) Ro

- Neet Anaerobic Soil Metabolism Study: Laboratory Project ID:
PMS

- 192: MRC

- 86

- 09. Unpublished study pre

- pared by Stauffer Chemical Co., Mountain View Research Center. 37 p.

MRID: 16295 7 Carley, S. (1986) Anaerobic Soil Metabolism Study [with] Ro

- Neet: Interim Report 1:
PMS

- 192: Project No. 148217. Unpublished study prepared by Stauffer Chemical Co., Inc., Mountain View Re

- search Center in cooperation with Analytical Development Corp. 16 p.

MRID: 165260 Spillner, C.; Carley, S. (1986) Ro

- Neet Anaerobic Soil Metabolism Study/Revised: Laboratory Project PMS

- 192

- R; MRC

- 86

- 09. Unpublished study prepared by Stauffer Chemical Co. 38 p.

MRID: 92025022 Calderbank, A. (1990) ICI Americas Inc. Phase 3 Summary of MRID 00162652. Ro

Neet Anaerobic Soil Metabolism Study/ Revised: Report No. MRC

- 86

- 09; Study No.
PMS

- 192

- R. Prepared by Stauffer Chemical Co. 20 p.

Guideline: 162

- 3 Anaerobic aquatic metab olism

.

------------------------- ------------------------------------------------------------ MRID: 42997901 Eya, B.; Carley, S. (1993) Cycloate: Anaerobic Aquatic Soil Metabolism: Lab Project Number: RR 93

- 079B. Unpublished study prepared by Zeneca Inc., Western Research Center. 85 p.

Guideline: 163

- 1 Leach ing /adsorp tion /desorption

------------------------------------------------------------------------------------- MRID: 20566 Gray, R.A.; Weierich, A.J. (1968) Leaching of five thiocarbamate herbicides in soils. Weed Science 16(1):77

- 79. (Also~In~unpub

- lished submission received Apr 25, 1978 under 476

- 2180; sub

- mitted by Stauffer Chemical Co., Richmond, Calif.; CDL:233576

- B)

MRID: 68700 Koren, E.; Foy, C.L.; Ashton, F.M. (1968) Phytotoxicity and persistence of four thiocarbamates in five soil types. Weed Science 16:172

- 175. (Also in unpublished submission received Jun 23, 1977 under 476

- 2182; submitted by Stauffer Chemica l Co.,Page 28 of 38



### Richmond, Calif.; CDL:230714

- F)

MRID: 68702 Koren, E.; Foy, C.L.; Ashton, F.M. (1969) Adsorption, volatility, and migration of thiocarbamate herbicides in soil. Weed Science 17:148

- 153. (Also in unpublished submission received Jun 23, 1977 unde r 476

- 2182; submitted by Stauffer Chemical Co., Richmond, Calif.; CDL:230714

- H)

MRID: 88543 Gray, R.A.; Weierich, A.J. (1965?) Leaching of Five Thiocarbamate Herbicides in Soils. (Unpublished study received Aug 14, 1967 under 8F0639; submitted by Stauf fer Chemical Co., Richmond, Calif.; CDL:091110

- W))

MRID: 93485 Gray, R.A.; Weierich, A.J. (1965?) Behavior and Persistence of S

- Ethyl Cyclohexylethylthiocarbamate (R

- 2063) in Soils. (Unpub

- lished study received Feb 14, 1967 under 7F0522; submitted by Stauffer Chemical Co., Richmond, Calif.; CDL:090621

- F)

MRID: 108333 Gray, R.; Weierich, A. (1968) Behavior and Persistence of Thio

- carbamate Herbicides in Soils under Different Environmental Conditions. (Unpublished study received Nov 4, 1971 under 1 F1042; submitted by Stauffer Chemical Co., Richmond, CA; CDL: 091932

- H)

MRID: 115035 Norris, R.; Soliman, K. (1973) Comparative Leachability of Preplant Incorporated Sugarbeet Herbicides. (Unpublished study received Apr 12, 1974 under 10065

- EX

- 4; submi tted by Fisons Corp., Agri

- cultural Chemicals Div., Bedford, MA; CDL:127693

- W)

MRID: 115354 Stauffer Chemical Co. (1967) The Results of Tests on the Amount and Nature of the Residue, and the Analytical Methodology: ?Tillam|. (Compilation; unpublished study received Jul 30, 1967 under 8F0628; CDL:090822

- L)

MRID: 117144 Gray, R.; Weierich, A. (1965) Persistence of Ro

- Neet in Soils. (Unpublished study received Nov 29, 1965 under unknown admin. no.; submitted by Stauffer Chemical Co., Richmond, CA; CDL: 123664

- C)

MRID: 124072 Hercules, Inc. (1974) Efficacy Data (Weed Control in Sugar Beets). (Compilation; unpublished study received Nov 1, 1974 under 5G1574; CDL:095224

- B)

MRID: 131467Page 29 of 38



### Antognini, J.; Gray, R.; Menn, J. (1970) Chemical, physical, toxicological and biochemical properties of cycloate. Pages 293

- 299, In Proceedings, Second International Meeting on Selective Weed Control in Beet Crops: Vol. 1. ?S.l.: s.n|. (Also In un

p ublished submission received Oct 7, 1983 under 476

- 1978; sub

- mitted by Stauffer Chemical Co., Richmond, CA; CDL:251456

- E)

MRID: 131468 Gray, R.; Weierich, A. (1968) Behavior and persistence of thiocarbamate herbicides in soils under different environme ntal condi

- tions. Pages 94

- 101, In Proceedings, 9th British Weed Control Conference: Vol. 1. ?S.l.: s.n.|. (Also In unpublished sub

- mission received Oct 7, 1983 under 476

- 1978; submitted by Stauf

- fer Chemical Co., Richmond, CA; CDL:251456

- H)

MRID: 131469 Stanger, C.; Appleby, A. (1971) Effect of soil type and irrigation method on lateral movement of cycloate. Weed Science 19(6):709

- 711. (Also In unpublished submission received Oct 7, 1983 under 476

- 1978; submitted by Stauffer Chemical Co., Rich mond, CA; CDL: 251456

- J)

MRID: 144961 Thomas, V.; Dennison, J. (1980) Adsorption and Desorption of [Carb

- on 14] ro

- neet in Keeton Sandy Loam Soil: MRC

- B

- 105; MRC

- 80

- 03 Unpublished study prepared by Stauffer Chemical Co. 14 p.

MRID: 162653 Maullis, J . (1986) Ro

- Neet Selective Herbicide Soil Leaching Study: Laboratory Project
ID: PMS

- 202: MRC

- 86

- 05. Unpublished study prepared by Stauffer Chemical Co., Mountain View Research Center. 32 p.

MRID: 41920603 Laster, W. (1991) Cycloate: Adsorption/Desorp tion in Four Soils: Lab Project Number: 39229: 91

- 035B: PMS 359. Unpublished study prepared by ABC Laboratories, Inc. 56

p.

Guideline: 163

- 2 Volatility

- lab

------------------------------------------------------------------------------------- MRID: 41920602 McGahen, L. (1991) Volatility of 14C

- Cycloate Applied to Soil: Lab Project Number:
PMS

- 343: RR

- 91

- 006B. Unpublished study prepared by ICI Americas Inc. Western Research Center and Pesticide Metabolism Center. 43 p.

Guideline: 164

- 1 Terrestrial field dissipation

------------------------------------------------------------------------------------- MRID: 68705Page 30 of 38



### Gray, R.A.; Weierich, A.J. (1968) Behavior and persistence of thiocarbamate herbicides in soils under different environmental conditions. Proceedings of the 9th British Weed Control Conference 9:94

- 101. (Also in unpublished submission received Jun 23, 19 77 under 476

- 2182; submitted by Stauffer Chemical Co., Richmond, Calif.; CDL:230714

- L)

MRID: 115029 Brickey, J.; Lardelli, R.; Perelini, E.; et al. (1973) Decline Study for Preplant Sugar Beet Herbicides

-- Woodland: SB

- 13

- 72. (Unpublished study received Apr 12, 1974 under 10065

- EX

- 4; pre

- pared by Univ. of California

-- Davis, Dept. of Botany and Plant Pathology, submitted by Fisons Corp., Agricultural Chemicals Div., Bedford, MA; CDL:127693

- M)

MRID: 116367 Rademacher, D. (1973) Letter sent to E. Sulliva n dated Jul 3, 1973 Results of bio

- assay run on 1972 applied herbicide test for wheat|. (Unpublished study received Apr 12, 1974 under 10065

- EX

- 4; prepared by Great Western Sugar Co., submitted by Fisons Corp., Agricultural Chemicals Div., Bedford, MA; C DL:127693

- P)

MRID: 124072 Hercules, Inc. (1974) Efficacy Data (Weed Control in Sugar Beets). (Compilation; unpublished study received Nov 1, 1974 under 5G1574; CDL:095224

- B)

MRID: 145057 Stauffer Chemical Co. (1984) [Residue Report on Ro

- Neet and Dyf on

- ate in Soil]: Project No: H

- 315

- SRS

- 77. Unpublished study. 62 p.

MRID: 41582404 Curry, K. (1989) Ro

- Neet 6

- E: Field Dissipation Study for Terrestrial Food Crop Uses Cycloate, California, 1987

- 1988: Lab Pro

- ject Number: RP 87

- 02: RR 89

- 041B. Unpu blished study prepared by ICI Americas Inc. 185 p.

MRID: 41582405 Curry, K.; Riggle, B.; Hoag, R. (1989) Ro

- Neet 6

- E: Field Dissipation Study for Terrestrial Food Crop Uses Cycloate California, 1988: Lab Project Number: RSO2

- 88

- 120: RR 89

- 019B. Unpubl ished study prepared by ICI Americas Inc. 181 p.

Guideline: 165

- 4 Bioaccumulation in fish

------------------------------------------------------------------------------------- MRID: 145556 McAllister, W.; Franklin, L. (1984) Uptake, Depuration a nd Biocon

- centration of (Carbon 14) Ro

- Neet by Bluegill Sunfish (Lepomis macrochirus): ABC Final Report #31682. Unpublished study pre

- pared by Analytical Bio

- Chemistry Laboratories, Inc. 247 p.

MRID: 41920601Page 31 of 38



### Subba

- Rao, R.; Tamichi, E. (1991) Cycloate : Bioaccumulation in Bluegill Sunfish: Lab Project Number: RR 91

- 045B: PMS 354: 39037. Unpublished study prepared by ICI America, Inc. 106 p.

Ecological Toxicity Data Submitted To Support Registration:

Guideline: 71

- 1 Avian Single Dose Oral Toxicity

------------------------------------------------------------------------------------- MRID: 132798 Fletcher, D. (1983) Report to ...: Acute Oral Toxicity Study with Ro

- Neet Technical in Bobwhite Quail: T

- 11188. (Unpublished study received Nov 30 1983 under 476

- EX

106; prepared by Bio

- Life Assoc., Ltd., submitted by Stauffer Chemical Co., Richmond, CA; CDL:072166

- A)

MRID: 92025001 Calderbank, A. (1990) ICI Americas Inc. Phase 3 Summary of MRID 00132798. Acute Oral Toxicity Study with Ro

- Neet Technical in Bobwhite Quail: Report No. T

- 11188; BLAL No. 83 QD 32. Prepared by Bio

- Life Associates Ltd. 11 p.

Guideline: 71

- 2 Avian Dietary Toxicity

------------------------------------------------------------------------------------- MRID: 1327 99 Joiner, R. (1975) Safety Evaluation of Ro

- Neet Technical by a Five

- day Feeding Study in Mallard Ducks: T

- 5471. (Unpublished study received Nov 30, 1983 under 476

- EX

106; submitted by Stauffer Chemical Co., Richmond, CA; CDL:072166

- B)

MRID: 132800
K nott, W.; Beliles, R. (1966) Ro

- Neet 6

- E Safety Evaluation by Feeding to Bobwhite Quail for Seven Days. (Unpublished study received Nov 30, 1983 under 476

- EX

- 106; prepared by Woodard Re

- search Corp., submitted by Stauffer Chemical Co., Richmond, CA; CDL: 072166

- C)

MRID: 145554 Beavers, J. (1984) A Dietary LC50 Study in the Bobwhite with Ro

- Neet Technical: Final Report: Project No. 144

- 121. Unpublished study prepared by Wildlife International Ltd. 14 p.

MRID: 42090306 Beavers, J. (1985) Ro

- Neet Techn ical: A Dietary LC50 Study with the Mallard: Final Report: Lab Project Number: 144

- 129: SPONSOR. Unpublished study prepared by Wildlife International Ltd. 19 p.

MRID: 92025002 Calderbank, A. (1990) Ici Americas Inc. Phase 3 Summary of MRID 00145554. R o

- Neet Technical: A Dietary LC50 Study in the Bobwhite, Final Report: Report No. T

- 12108:Page 32 of 38



### Study No. 144

- 121. Prepared by Wildlife International Ltd. 11 p.

MRID: 92025003 Calderbank, A. (1990) ICI Americas Inc. Phase 3 Summary of MRID 00132799. Ro

Neet Technical: a Dietary LC50 Study with the Mallard: Final Report No. T

- 12275; Study No. 144

- 129. Prepared by STAUFFER CHEMICAL COMPANY. 11 p.

Guideline: 72

- 1 Acute Toxicity to Freshwater Fish

------------------------------------------------------------------------------------- MRID: 84743 Bullock, C. (1968) Thiocarbamate Herbicides

-- Mosquito Fish Bio

- assay: Toxicologival Summary T

- 1272. (Unpublished study received Oct 8, 1981 under 476

- 2107; submitted by Stauffer Chemical Co., Richmond, Calif.; CDL:246020

- G)

MRID: 93479 Beliles, R.P.; Smart, T. (1965) R

- 2063: Acute Toxicity in Rainbow Trout. (Unpublished study received Sep 1, 1966 under 7F0522; prepared by Wood ard Research Corp., submitted by Stauffer Chemical Co., Richmond, Calif.; CDL:090620

- J)

MRID: 108342 Bullock, C. (1968) Thiocarbamate Herbicides: Mosquito Fish Bio

- assay: Toxicological Summary T

- 1272. (Unpublished study received Nov 4, 1971 under 1F10 42; submitted by Stauffer Chemical Co., Richmond, CA; CDL:091932

- Y)

MRID: 115089 Beliles, R.; Smart, T. (1965) R

- 2063: Acute Toxicity in Rainbow Trout. (Unpublished study received Feb 25, 1966 under unknown admin. no.; prepared by Woodard Research Corp ., submitted by Stauffer Chemical Co., Richmond, CA; CDL:104312

- A)

MRID: 132801 Bresolin, P. (1975) Ro

- Neet Technical (Lot No. RCK 1501): Laboratory Report T

- 5285. (Unpublished study received Nov 30, 1983 under 476

- EX

- 106; submitted by Stauffer Chemica l Co., Richmond, CA; CDL:072166

- D)

MRID: 143654 McAllister, W.; Cohle, P. (1984) Acute Toxicity of Ro

- Neet Technical to Bluegill Sunfish (Lepomis macrochirus): Static Acute Toxicity Report #31561. Unpublished study prepared by Analytical Bio

- Chemistry L aboratories, Inc. 52 p.

MRID: 41614703 Tapp, J. ; Sankey, S. ; Caunter, J. ; Stanley, R. et al. (1990) Cycloate: Determination of Acute Toxicity to Rainbow Trout (Sal

- mo gairdneri): Lab Project Number: S057/F/FT42/90. Unpublished study prepared by ICI, Brixham Laboratory. 19 p.Page 33 of 38



### MRID: 45608401 McCann, J. (1977) Acute Toxicity of Ro

- Neet 6E to Rainbow Trout. Unpublished study prepared by US EPA, Animal Biology Laboratory. 3 p.

MRID: 92025004 Calderbank, A. (1990) ICI Americas Inc. Phase 3 Summary of MRID 00143654. Acute Toxicity of Ro

- Neet Technical to Bluegill Sunfish (Lepomis macrochirus): Report No. T

11464; ABC No. 31561. Prepared by Analytical Biochemistry Laboratories. 11 p.

Guidel ine: 72

- 2 Acute Toxicity to Freshwater Invertebrates

------------------------------------------------------------------------------------- MRID: 143655 Forbis, A.; Burgess, D. (1984) Acute Toxicity of Ro

- Neet Technical to Daphnia magna: Static Acute Toxicity Report #31787. Unpublished study prepared by Analytical Bio

chemistry Laboratories, Inc. 33 p.

MRID: 92025005 Calderbank, A. (1990) ICI Americas Inc. Phase 3 Summary of MRID 00143655. Acute Toxicity of Ro

- Neet Technical to Daphnia magna: Re port No. T

- 12107; Study No. 31787. Prepared by Analytical Biochemistry Laboratories. 10 p.

Guideline: 72

- 4 Fish Early Life Stage/Aquatic Invertebrate Life Cycle Study

-------------------------------------------------------------------------------- ----- MRID: 21840 Bullock, C. (1968) Toxicological Summary T

- 1272: Thiocarbamate Herbicides Mosquito Fish Bioassay. (Unpublished study received Mar 27, 1972 under unknown admin. no.; submitted by Stauffer Chemical Co., Richmond, Calif.; CDL:120329

- Y)Page 34 of 38



## Appendix A. Ecotoxicity Data for Cycloate

Table A1. Acute Oral Toxicity of Cycloate to Birds
Species % ai LD 50 (mg ai/kg) Toxicity

Category MRID No.

Author/Year Study

Classification

Northern bobwhite (Colinus virginianus) 98.6 >2150 practically non

toxic Acc# 072166

Fletcher, 1983 Acceptable

Redwing Blackbirds Not
available Acc# 073005 Schaffer, 1983 invalid

Starling Not
available Acc# 073005 Schaffer, 1983 invalid



### Table A2. Subacute Dietary Toxicity to Birds

Species % ai 5

- Day LC50 (ppm ai) 1 Toxicity

Category MRID No.

Author/Year Study

Classification Northern bobwhite quail (Colinus virginianus) 96.8 >5620 practically

non

- toxic 00145554

Beavers, 1984 Acceptable

Northern bobwhite quail (Colinus virginianus) 73.9 >56,000 (8 day) practically

non

- toxic Acc#072166

Knotts, 1965 supplemental

Mallard duck (Anas platyrhynchos) 98.6 >10,000 (8 day) practically

non

- toxic Acc#072166

Joiner, 1975 supplemental

Mallard duck (Anas platyrhynchos) 96.8 >5395 practically

non

- toxic 42090306

Beavers, 1991 Acceptable

1 Test organisms observed an additional three days while on untreated feed.



### Table A3. Acute Oral Toxicity of Cycloate to Mammals Species % ai Test Type Toxicity Value Affected Endpoints MRID/Acc.

No. Laboratory r at ( Rattus norvegicus ) 73.1 Acute oral LD 50 = 4195 mg/kg (F)
LD 50 = 5460 mg/kg (M) mortality Acc. No.
073004

Laboratory rat 7.2 Acute oral LD 50 = 3250 mg/kg (F)
LD 50 = 4175 mg/kg (M) mortality 00132271

Laboratory rat 98.0 Acute oral LD 50 = 2275 mg/kg (F)
LD 50 = 3200 mg/kg (M) mortality 00132790Page 35 of 38



### Table A4. Reproductive Toxicity of Cycloate to Mammals Species % ai Test Type Toxicity Value Affected Endpoints MRID/Acc. No. Laboratory rat 95.3 Reproduction

- 3 generation NOAEL = 8

mg/kg/day (160 ppm)
LOAEL = 24 mg/kg/day decreased weight,

decreased pup survival (72 mg/kg/day, 1440 ppm) 00132795

Laboratory rat 88.3 Reproduction

- 2 generation NOAEL = 50 ppm

LOAEL = 400 ppm decreased weight gain in

both generations for

pups 41691901 (supplemental)



### Table A5. Inhalation Toxicity of Cycloate to Mammals Species % ai Test Type Toxicity Value Affected Endpoints MRID/Acc.
No. Laboratory rat 73.9 Acute Inhalation LC50>5.03 mg/L

(one dose) one mortality, labored

breathing, tearing, salivation 00132792

Laboratory rat 98.4 Inhalation
21

- day NOAEL = 1.2 ug/L

LOAEL = 12.0 ug/L brain neuromal, cell

necrosis 43552101



### Table A6. Contact Toxicity of Cycloate to Terrestrial Invertebrates Species % ai 96

- hr LD50 (μg a.i./bee) Toxicity Category MRID No. Author/Year Study

Classification Honey bee ( Apis mellifera ) 73.9 29.01 Practically non

toxic MRID 00036935

Atkins et. al., 1975 AcceptablePage 36 of 38



### Table A7. Acute Toxicity of Cycloate to Freshwater Fish Species % ai 96

- hr LC50 (mg a.i./L) Toxicity

Category MRID No.

Author/Year Study

Classification
Rainbow trout ( Oncorhynchus mykiss ) 96.8 7.0 moderately toxic 41614703 Tapp, 1990 Acceptable

Rainbow trout 97.8 4.5 moderately toxic Acc# 090620 Beliles, 1965 Acceptable

Rainbow trout 74.24 5.6 moderately toxic Acc# 090620 Beliles, 1965 Acceptable

Rainbow trout 73.9 10.5 moderately toxic 45608401 McCann, 1977 Acceptable

Rainbow trout 73.9 8.2 moderately toxic 45608401 McCann, 1977 Acceptable

Rainbow trout 73.9 6 moderately toxic 45608401 McCann, 1977 Acceptable

Bluegill sunfish ( Lepomis macrochirus ) 98.6 6.8 moderately toxic Acc# 072166 Bresolin, 1975 supplemental

Bluegill sunfish 96.8 4.6 moderately toxic 00143654 McAllister, 1984 Acceptable

Mosquito fish ( Gambusia affinis ) formulation 10 moderately toxic 00084743 Bullock, 1968 supplemental



### Table A8. Acute Toxicity of Cycloate to Freshwater Invertebrate s Species % ai 48

- hr LC50 (mg a.i./L) Toxicity Category MRID No. Author/Year Study Classification
Waterflea ( Daphnia magna ) 96.8 24 Slightly toxic 00143655 Forbis, 1984 Acceptable

Scud Not available 05001497 Sanders, 1970 invalidPage 37 of 38



## Appendix B. Screening Level Models to Evaluate Potential Importance of Drinking Water and Inhalation Exposure Pathways

SIP ( Screening Imbibition Program, v1.0) Inputs and Conclusions
Table 1. Inputs

Parameter Value

Chemical name cycloate
Solubility (in water at 25 o C; mg/L) 85

Mammalian LD 50 (mg/kg

- bw) 2275 Mammalian test species laboratory rat Body weight (g) of "other" mammalian species

Mammalian NOAEL (mg/kg

- bw) 8 Mammalian test species laboratory rat Body weight (g) of "other" mammalian species

Avian LD 50 (mg/kg

- bw) 2150 Avian test species northern bobwhite quail Body weight (g) of "other" avian species Mineau scaling factor 1.15

Mallard NOAEC (mg/kg

- diet) Bobwhite quail NOAEC (mg/kg

- diet) NOAEC (mg/kg

- diet) for other bird species 0 Body weight (g) of other avian species NOAEC (mg/kg

- diet) for 2nd other bird species 0 Body weight (g) of 2nd other avian species

Table 2. Mammalian Results

Parameter Acute Chronic Upper bound exposure (mg/kg

- bw) 14.6200 14.6200 Adjusted toxicity value (mg/kg

- bw) 1749.8403 6.1533 Ratio of exposure to toxicity 0.0084 2.3760

Conclusion* Drinking water exposure alone is NOT a potential concern for mammals Exposure through drinking water alone is a potential concern for mammals

Table 3. Avian Results

Parameter Acute Chronic Upper bound exposure (mg/kg

- bw) 68.8500 68.8500 Adjusted toxicity value (mg/kg

- bw) 1548.9235 0.0000 Ratio of exposure to acute toxicity 0.0445 0.0000

Conclusion* Drinking water exposure alone is NOT a potential concern for birds Due to insufficient data, risk cannot be precluded

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

- target animals.Page 38 of 38



### STIR ( S creening T

ool for I nhalation R isk, v1.0) Inputs and Conclusions 

## Input

Application and Chemical Information

Enter Chemical Name cycloate
Enter Chemical Use herbicide
Is the Application a Spray? (enter y or n) y If Spray What Type (enter ground or air) ground Enter Chemical Molecular Weight (g/mole) 215.4 Enter Chemical Vapor Pressure (mmHg) 6.20E

- 03 Enter Application Rate (lb a.i./acre) 4

Toxicity Properties

Bird
Enter Lowest Bird Oral LD 50 (mg/kg bw) 2150 Enter Mineau Scaling Factor 1.15 Enter Tested Bird Weight (kg) 0.178
Mammal

Enter Lowest Rat Oral LD 50 (mg/kg bw) 2275

Enter Lowest Rat Inhalation LC 50 (mg/L) 5.03 Duration of Rat Inhalation Study (hrs) 4 Enter Rat Weight (kg) 0.35



## Output
Results Avian (0.020 kg ) Maximum Vapor Concentration in Air at Saturation (mg/m 3 ) 7.19E+01
Maximum 1

- hour Vapor Inhalation Dose (mg/kg) 9.03E+00
Adjusted Inhalation LD 50 2.65E+01
Ratio of Vapor Dose to Adjusted Inhalation LD 50 3.41E

- 01 Proceed to Refinements
Maximum Post

- treatment Spray Inhalation Dose (mg/kg) 4.23E

- 01 Ratio of Droplet Inhalation Dose to Adjusted Inhalation LD 50 1.59E

- 02 Exposure not Likely Significant



### Results Mammalian (0.015 kg ) Maximum Vapor Concentration in Air at Saturation (mg/m 3 ) 7.19E+01
Maximum 1

- hour Vapor Inhalation Dose (mg/kg) 1.14E+01
Adjusted Inhalation LD 50 2.99E+02
Ratio of Vapor Dose to Adjusted Inhalation LD 50 3.79E

- 02 Exposure not Likely Significant
Maximum Post

- treatment Spray Inhalation Dose (mg/kg) 5.31E

- 01 Ratio of Droplet Inhalation Dose to Adjusted Inhalation LD 50 1.77E

- 03 Exposure not Likely Significant