Sedaxane(129223) Human Health Risk Assessment D419897' D421932

UNITED ST ATE S ENV IRONMEN TAL PROTECTION AGENCY

WASHINGTON, D.C. 20460



### MEMORANDUM

Date: 20-JAN-20 15 OFF ICE OF
CHEM ICAL SAF ETY AND
POLLUTION PRE VEN TION



### SUBJECT: Sedaxane. Human Health Risk Assessment to Support New Seed Treatment

Uses on Cotton and Sugar Beet.



### PC Code: 129223


### Decision No.: 489552, 493224


### Petition No

. : 4F8263


### Risk Assessment Type: Single Chemical Aggregate


### TXRNo.: NA



### MRID No.: 49383101, 49383102 

### DP Barcode: D419897

, D421932 

### Registration No.: 100-1 38 1

, 100

- 1374 

### Regulatory Action: Section 3 Registration


### Case No.: NA



### CAS No. : 874967-67-6

40 

### CFR: §180 .665



### FROM: William H. Donovan, Ph.D., Risk Assessor

# H~ 'jl,

# -~­ William Irwin, Ph.D., DABT

, T xic gist

# (.)-'~~ Seyed T adayon, Chemist

Ri sk Assessment Branch V ( V)

Health Effects Division (HED) (7509P)

THROUGH: Michael S. Metzger, Chief

, RAB V & VI! 

## I 

# 1 /) 

# J )**~** HED (7509P) 

# 0P-

j



### TO: D riss Benmhend, Risk Manager Fungicide Branch Registration Division (7505 P )

Syngenta has requested registrat i on of the fungicide se daxane for seed treatment use on cotton
and sugar beet. The Registration Di vision of the Office of Pesticide Programs (O PP) has requested that HED evaluate hazard and exposure data and conduct dietary

, occupational, and
aggregate exposure assessments, a s needed, to estimate the risk to human health that will result

from the established and proposed seed treatment uses of sedaxane.

Page 1 of76Sedaxane(l29223) Human H ealth Ri sk Assessme n t 0419897, D4 2 1 932

HED h as eva luated th e toxicity and expo s ur e databases for sedax ane, and ha s conducted a human health ri s k asses smen t in s upport of th e proposed u ses

. A s ummary of the findings and an

assessment of human health risk resulting from established and proposed uses of sedaxane are

p r ovided in this document. The BED t eam members contributing to this risk assessment include
William Irwin (hazard assessment), Seyed Tadayo n (occupational / residential assessments)

, and

Will i am Donovan (residu e chem i stry, dietary expos ure, and ri s k assessment).

Pa g e 2 of76Sedaxane (129223) Human Health Risk Assessme nt D419897, D421932

Page 3 of 76 

### Table of Contents

1.0 Executive Summary

................................ ................................ ................................ ............. 5
2.0 HED Recommendations

................................ ................................ ................................ ....... 6
2.1 Data Deficiencies/Conditions of Registration

................................ ................................ .. 6
2.2 Tolerance Considerations

................................ ................................ ................................ . 7
2.2.1 Enforcement Analytical Method

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

2.2.2 International Harmonization

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

2.2.3 Recommended Tolerances

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

2.2.4 Revisions to Petitioned

- For Tolerances

................................ ................................ .... 8

2.3 Label Recommendations

................................ ................................ ................................ .. 8
2.3.1 Recommendations from Residue Reviews

................................ ............................... 8

2.3.2 Recommendations from Occupational Assessment

................................ .................. 8

3.0 Introduction

................................ ................................ ................................ .......................... 8
3.1 Chemical Identity

................................ ................................ ................................ ............. 8
3.2 Physical/Chemical Characteristics

................................ ................................ ................... 9
3.3 Pesticide Use Pattern

................................ ................................ ................................ ........ 9
3.4 Anticipated Exposure Pathways

................................ ................................ ..................... 11
3.5 Consideration of Environmental Justice

................................ ................................ ........ 11
4.0 Hazard Characterization and Dose

- Response Assessment

................................ ................ 12
4.1 Toxicology Studies Available for Analysis

................................ ................................ ... 12
4.2 Absorption, Distribution, Metabolism, & Elimination (ADME)

................................ ... 12
4.2.1 Dermal Absorption

................................ ................................ ................................ ..... 13
4.3 Toxicological Effects

................................ ................................ ................................ ..... 13
4.4 Safety factor for Infants and Children (FQPA Safety Factor)

................................ ....... 15

4.4.1 Completeness of the Toxicology Database

................................ ................................ 16
4.4.2 Evidence of Neurotoxicity

................................ ................................ .......................... 16
4.4.3 Evidence of Sensitivity/Susceptibility in the Developing or Young Animal

............. 16
4.4.4 Residual U ncertainty in the Exposure Database

................................ ......................... 16
4.5 Toxicity Endpoint and Point of Departure Selections

................................ .................... 17
4.5.1 Dose

- Response Assessment

................................ ................................ ....................... 17
4.5.2 Recommendation for Combining Routes of Exposures for Risk Assessment

........... 18
4.5.3 Cancer Classification and Risk Assessment Reco mmendation

................................ .. 18
4.5.4 Summary of Points of Departure and Toxicity Endpoints Used in Human Risk

Assessment

................................ ................................ ................................ ................................ 18
5.0 Dietary Exposure and Risk Assessment

................................ ................................ ............ 20
5.1 Metabolite/Degradate Residue Profile

................................ ................................ ........... 20
5.1.1 Summary of Plant and Livestock Metabolism Studie s

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

5.1.2 Summary of Environmental Degradation

................................ ............................... 21

5.1.3 Comparison of Metabolic Pathways

................................ ................................ ....... 21

5.1.4 Residues of Concern Summary and Rationale

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

5.2 Food Residue Profile

................................ ................................ ................................ ...... 23Sedaxane (129223) Human Health Risk Assessme nt D419897, D421932

Page 4 of 76 5.3 Water Residue Profile

................................ ................................ ................................ .... 24
5.4 Dietary Risk Assessment

................................ ................................ ................................ 24
5.4.1 Description of Residue Data Used in Dietary Assessment

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

5.4.2 Percent Crop Treated Used in Dietary Assessment

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

5.4.3 Acute Dietary Risk Assessment

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

5.4.4 Chronic Dietary Risk Assessment

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

5.4.5 Cancer Dietary Risk Assessment

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

5.4.6 Summary Table

................................ ................................ ................................ ....... 26

6.0 Residential (Non

- Occupational) Exposure/Risk Characterization

................................ .... 26
6.1 Spray Drift

................................ ................................ ................................ ...................... 26
7.0 Aggregate Exposure/Risk Characterization

................................ ................................ ....... 27
8.0 Cumulative Exposure/Risk Characterization

................................ ................................ ..... 27
9.0 Occupational Exposure/Risk Characterization

................................ ................................ .. 27
9.1 Short

- /Intermediate

- Term Handler Risk

................................ ................................ ........ 27
9.2 Short

- /Intermediate

- Term Post

- Application Risk

................................ .......................... 32
9.2.1 Dermal Postapplication Risk

................................ ................................ ................... 32

9.2.2 Inhalation Postapplication Risk

................................ ................................ .............. 32

10.0 References

................................ ................................ ................................ .......................... 32 Appendix A. Toxicology Profile and Executive Summaries

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

A.1 Toxicology Data Requirements

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

A.2 Toxicity Profiles

................................ ................................ ................................ ............. 36
A.3 Hazard Identification and Endpoint Selection

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

A.4 Executive Summaries

................................ ................................ ................................ ..... 53 Appe ndix B. Metabolism Data

................................ ................................ ................................ ..... 74 B1. Structures and Identity of Metabolites of Sedaxane

................................ .......................... 74 Appendix C. Physical/Chemical Properties

................................ ................................ ................. 76 Appendix D. Review of Human Research

................................ ................................ ................... 76Sedaxane (129223) Human Health Risk Assessme nt D419897, D421932

Page 5 of 76 1.0 Executive Summary

Sedaxane is a pyrazole carboxamide fungicide register ed for use as a seed treatment in a variety of crops

. The current petition ( # 4 F 8263 ) proposes to expand seed treatment uses to include cotton and sugar beet

.

The sedaxane toxicology database is considered complete. The toxicological effects reported in
the submitted animal studies such as mitochondrial disintegration and glycogen depletion in the
liver are consistent with the pesticidal mode of action also being the mode of toxic action in
mammals

. The rat is the most sensitive species tested, and the main target tissue for sedaxane is
the liver

. Sedaxane also caused thyroid hypertrophy/hyperplasia

. I n the acute neurotoxicity (ACN) and sub

- chronic neurotoxicity (SCN) studies , sedaxane caused decreased activity, decreased muscle tone, decreased rearing and decreased grip strength

.

There are indications of reproductive toxicity in rats such as decreased follicle counts , but these
effects did not result in reduced fertility. In the rat, no adverse effects in fetuses were seen in developmental toxicity studies at maternally toxic dose s. However , in the rabbit developmental study , fetal toxicity was observed at the same doses as the dams. Offspring effects in the rat reproduction study occurred at the same doses causing parental effects, thus there was no

qua ntitative increase in sensi tivity in rat pups. Sedaxane is tumorigenic in the liver in the rat and mouse, and led to tumors in the thyroid and uterus in the rat and was classified as “likely to be carcinogenic to humans.” Sedaxane was negative in the mutagenicity studies. The 28

- day dermal study did not show systemic toxicity at the limit dose of 1000 mg/kg/day. Sedaxane has low acute toxicity by the oral, dermal, and inhalation routes. It is not a dermal sensitizer, causes no skin irritation and only slight eye irritation.

T he risk assessments were based on the most sensitive endpoints in the toxicity database, and the no observed adverse effect levels ( NOAELs ) selected for risk assessment are considered protective of potential developmental , neurotoxic, and immunotoxic effec ts for infants and children. Further, highly conservative exposure estimates were incorporated into the risk

assessment; therefore, reduction of the 10x Food Quality Protection Act (FQPA) safety factor to

1x is considered appropriate.

For the acute dietary risk assessment, an ac ute reference dose (aRfD) of 0.3 0 mg/kg/day was selected for assessment of all po pulations, based on a NOAEL of 3 0 mg/kg/day in the rat ACN study

. Since the FQPA 10x factor is being reduced to 1 x , the population adjusted dose (PAD) is equal to the RfD. For the chronic dietary risk assessment, a chron ic reference dose (cRfD) of

0.11 mg/kg/day was selected for assessments of all popula tions, based on a NOAEL of 11 mg/kg/day from the chronic toxicity study in rats . For short

- a nd intermediate

- term occupational exposure scenarios involving inhalation exposure, the NOAEL of 30 mg/kg/day was selected
from the rat acute neurotoxicity study

. No non

- cancer dermal hazard was identified for
sedaxane.

The sedaxane residue chemistry dat abase is complete. The nature of the residue in plants and rotational crops has been adequately delineated , with parent sedaxane defined as the residue of
concern for tolerance enforcement and risk assessment. The crop field trial data are adequate toSedaxane (129223) Human Health Risk Assessme nt D419897, D421932

Page 6 of 76 support tolerances and registrations for cotton and sugar beet

. P lant back restrictions have been proposed for rotational crops based on field rotational crop studies; with recommended modifications, these are appropriate

. No sedaxane residues are expect ed in livestock. Adequate storage stability, method validation data and processing studies have been submitted. An acceptable liquid chromato graphy/tandem mass spectrometry (LC/MS/MS) analytical method is available to enforce the proposed tolerances.

Environmentally, sedaxane is a moderately mobile chemical that is expected to be persistent in
the environment in aerobic and anaerobic conditions. Based on the environmental fate parameters, there is the potential for sedaxane to reach drinking water res ources. D rinking water concentrations were estimated using computer models.

Highly conservative acute dietary (food and water) assessments using tolerance level residues, assuming 100% crop treated

, and incorporating modeled water residue estimates dem onstrated
that risk level s w ere <2 % of the aPAD at the 95 th percentile exposure . Partially refined chronic and cancer assessments using anticipated residue levels for food, percent crop treated information, and screening level water residue estimates demonstrated that risk levels were ≤1 %
of the cPAD for the U .S. population and all population subgroup s , and that t he c ance r risk
estimate for the U.S. population was 2 × 10

- 6

.

There are no residential uses for sedaxane ; therefore, the aggrega te risk estimate for this chemical is equivalent to the dietary risk estimate and there are no concerns for acute or chronic aggregate risk estimates for sedaxane

.

No non

- cancer dermal hazard was identified for sedaxane ; therefore occupational handler (non

cancer) risks were assessed for the inhala tion route of exposure only. Handler cancer risks were
assessed for commercial sugar beet (seed processing only) and cotton seed treatment and planters by summ ing potential dermal and inhalation exposures. C ancer r isk estimates ranged between 4

× 10

- 10 to 1 × 10

- 6 for commercial seed treatment activities and planters

. Postapplication inhalation exposure is expected to be negligible; therefore a quantitative postapplication risk

assessment was not conduct ed.

This risk assessment relies in part on data from studies in which adult human subjects were intentionally exposed to a pesticide or other chemical. These studies, which form the basis of the
Seed Treatment Standard Operating Procedures ( SOPs )

, have been d etermined to require a review of their ethical conduct, have received that review, and have been determined to be
ethical

.

2.0 HED Recommendations

Pending submission of revised rotational crop restrictions consistent with recommendations provided in Section 3.3 , there are no other residue chemistry, occupational, or toxicolog ical data deficiencies that would preclude the establishment of permanent tolerances for residues of
sedaxane as shown in Table 2.2. 3.

2.1 Data Deficiencies/Conditions of Reg istrationSedaxane (129223) Human Health Risk Assessme nt D419897, D421932

Page 7 of 76 None

2.2 Tolerance Considerations

2.2.1 Enforcement Analytical Method

A n adequate analytical method is available to enforce the proposed tolerances for sedaxane in plant commodities. A m odification of the Quick, E asy, C heap, Eff ective , R ugged , and S afe ( QuEChERS ) method was developed for the determination of residues of sedaxane (as its isomers SYN508210 and SYN508211) in/on various crops. The sedaxane isomers (SYN508210 and SYN508211) are quantitatively determined by LC/MS/MS. The validated limit of quantitation (LOQ) reported in the method is 0.005 ppm for both sedaxane isomers

.

A successful independent laboratory validation (ILV) study was also conducted on the modified QuEChERS method using samples of wheat gr een forage and wheat straw fortified with SYN508210 and SYN508211 at 0.005 and 0.05 ppm.

Sedaxane has also been subjected to analysis by the Food and Drug Administration ( FDA ) multi

residue method protocols. Sedaxane is not recovered by the FDA multi

- r esidue methods.

The analytical standard for sedaxane, with an expiration date of February 28, 2018 , is currently available in the EPA National Pesticide Standards Repository [personal communication from T.
Cole of Analytical Chemistry Branch/Biological a nd Economic Analysis Division ( ACB/BEAD )

to W. Donovan

, 12/16 /201 4 ].

2.2.2 International Harmonization

No Codex or Canadian MRLs have been established for sedaxane in/on cotton or sugar beet.

2.2.3 Recommended Tolerances

Table 2.2.3 summarizes the registrant’s proposed tolerances and the Agen cy’s tolerance
recommendations. The current tolerance expression for sedaxane in 40 CFR § 180.665 appropriately read s as follows:

Tolerances are established for residues of the fungicide sedaxane , includin g its metabolites and degradates , in or on the commodities listed below. Compliance with the tolerance levels specified below is to be determined by measuring only sedaxane, N

- [2

- [1,1′

- bicyclopropyl]

- 2

- ylphenyl]

- 3

- (difluoromethyl)

- 1

- methyl

- 1 H

- pyrazole

- 4

-

ca rboxamide , as the sum of its cis

- and trans

- isomers in or on the commodity.Sedaxane (129223) Human Health Risk Assessme nt D419897, D421932

Page 8 of 76 Table 2.2.3. Tolerance Summary for Sedaxane.
Commodity Proposed Tolerance (ppm) Recommended

Tolerance (ppm) Comments; Correct Commodity

Definition

Cotton, undelinted seed 0.01 0.01 Cotton, undelinted seed
Cotton, gin byproducts 0.01 0.01 Cotton, gin byproducts

Beet, sugar 0.01 0.01 Beet, sugar, root s

2. 2.4 Revisions to Petitioned

- For Tolerances

None

2.3 Label Recommendations

2.3.1 Recommendations from Residue Reviews

Current sedaxane labels restrict the planting of treated potato seed pieces to 24

- month intervals.
HED recommends this interval be reduced to 12 months. See Rotational Crop Restrictions in
Section 3.3 for more details.

2.3.2 Recommendations from Occupational Assessment

None

3.0 In troduction

3.1 Chemical Identity

The structure and chemical identify for sedaxane are shown in Table 3.1. The structures for all metabolites discussed in this risk assessment are shown in Appendix B.

Table 3.1

. Test Compound Nomenclature. Compound Chemical Structure

Mixture of trans (SYN508210) and cis (SYN508211) isomers

Common name Sedaxane Company experimental name SYN524464 [mixture of trans (SYN508210) and cis (SYN508211) isomers]

IUPAC name Mixture of cis isomers 2’

- [(RS,2RS)

- 1,1’

- bicycloprop

- 2

- yl]

- 3

- (difluoromethyl)

- 1

- methylpyrazole

- 4

- carboxanilide and trans isomer 2’

- [(RS,2SR)

- 1,1’

- bicycloprop

- 2

- yl]

- 3

- (difluoromethyl)

- 1

- methylpyrazole

- 4

- carboxanilideSedaxane (129223) Human Health Risk Assessme nt D419897, D421932

Page 9 of 76 Table 3.1

. Test Compound Nomenclature.

CAS name 1H

- Pyrazole

- 4

- carboxamide, N

- [2

- [1,1'

- bicyclopropyl]

- 2

- ylphenyl]

- 3

- (difluoromethyl)

- 1

- methyl

CAS # 874967

- 67

- 6

- Mixture of 599197

- 38

- 3 (trans isomer) and 599194

- 51

- 1 (cis isomer)

End

- use product/EP 4.3 lb ai/gal FS formul ation (Sedaxane 500FS Fungicide )

0.0667 lb sedaxane/gal FS formulati on (A17511B Fungicide ), MAI product containing sedaxane, difenoconazole, mefenoxam, and thiamethoxam

0.115 lb sedaxane/gal FS formulation (A16874F Fungicide ), MAI product containing sedaxane, difenoconazole, and mefenoxam

Chemical Class Pyrazole Carboxamide Known Impurities of Concern None

3.2 Physical/Chemical Characteristics

The physical and chemical properties, as well as a summary of relevant environmental fate parameters are detailed in Appendix C.

Sedaxane has a low vapor pressure (

~ 10

- 7 Pascal (Pa) ) and is, therefore, not a volatile pesticide.
Based on its octanol water partition coefficient , sedaxane is not expected to bioaccumulate in lipophilic matrices. A fish bioconcentration study confirms that accumulation does not occur.
Seda xane has low water solubility (14 ppm) and does not dissociate ; ho wever, e nvironmentally,
sedaxane is a moderately mobile chemical that is expected to be persistent in the environment in

ae robic and anaerobic conditions. Based on the environmental fate pa rameters, there is the potential for sedaxane to reach water resources.

3.3 Pesticide Use Pattern

The proposed use pattern for sedaxane in/ on cotton and sugar beet is summarized in Table 3.3. 1.

Table 3

. 3 .1. Summary of Directions for Proposed New Use s of Sedaxane.

Application Type Formulation

[EPA File Symbol No.] Application Rate

lb ai/100 lb seed [g ai/100 kg seed] (mg ai/seed) Use Directions and Limitations

Cotton

Seed treatment 4.3 lb/gal FS

[100

- 1 347 ] 0.0027

- 0.020

[2.7

- 20] (0.002

- 0.017) 1 Do not use seed for feed, food or oil purposes. Store

away from feeds and foodstuffs. Excess treated seed may be used for ethanol production only if (1) by

products are not used for livestock feed and (2) no measurable residues of pesticide remain in eth anol by

products that are used for agronomic practice. The maximum number of applications per year is 2.

Sugar Beet ( n ot allowed on sugar beets grown for seed production)

Seed treatment 4.3 lb/gal FS

[100

- 1347 ] 0 .044

- 0. 66

[ 44

- 66 0 ] 2 (0.0050

- 0.075) As aboveSedaxane (129223) Human Health Risk Assessme nt D419897, D421932

Page 10 of 76 1 Assuming an average seed size of 5,500 seeds/pound , as indicated in the Use Rate section of the label

. However, HED assumes 4,500 seeds/pound [ J. Becker and S. Ratnayake, “Acres Planted per day and Sowing Rates of Crops
Grown in the U.S.” 24

- MAR

- 2011], which implies a maximum application rate of 0.020 mg sedaxane/seed.

2 Calculated assuming 40000 seeds/lb. Label expresses use rate in terms of fl oz and g ai per 100,000 seeds: 0.03

– 0.49 fl oz product/100,000 seeds and 0.50

– 7.5 g ai/100,000 seeds.

Rotational Crop Restrictions

From the Vibrance® label (EPA Reg. No. 100

- 1374)

Following sedaxane treated seeds except potato seed pieces:

 All crops that have not been treated with sedaxane may be planted 30 days after p lanting
sedaxane treated seeds.

 All crops treated with sedaxane may be replanted immediately with the exception of
potato.

Following potato seed pieces treated with sedaxane:

 No sedaxane treated seeds may be planted for a 24

- month period following plant ing of sedaxane treated potato seed pieces.

 All crops treated with sedaxane other than potato may be replanted immediately. No sedaxane treated potato seeds may be planted for a 24

- month period following planting of sedaxane treated potato seed pieces.

From the CruiserMaxx® Vibrance Potato label (EPA No. 100

- 1381)

Table 3.3.2. Rotational Crop Plant Back Intervals. Crop Planted Immediate Plant Back Minimum 30

- Day Plant

Back Minimum 60

-

Day Plant

Back 24

- Month

Plant

Back Canola, Soybean, Cereal
Grains (barley, oat, rye, triticale, wheat), Corn, Sorghum, Subgroup 6C, Subgroup 20A, Cotton, Sugar beet Canola, Soybean, Cereal Grains (barley, oat, rye, triticale, wheat), Corn, Sorghum, Subgroup 6C, Subgroup 20A, Cotton, Potato, Sugar beet All other crops

-- --

Potato Canola, Soybean, Cereal Grains (barley, oat, rye, triticale, wheat), Corn, Sorghum, Subgroup 6C, Subgroup 20A, Cotton, Sugar beet -- All other crops Potato

Conclusions The use directions are adequate to allow evaluation of the residue data relative to the proposed
use in the U.S. The proposed maximum application rates are supported by the submitted field
trial data

.

T able 3.3.2, revised to indicate a 12

- month PBI for potato instead of 24

- months

, should be included in both the CruiserMaxx® Vibrance Potato label (EPA No. 100

- 1381) and the Vibrance® label (EPA Reg. No. 100

- 1374). Alternatively, if a table format is not preferred forSedaxane (129223) Human Health Risk Assessme nt D419897, D421932

Page 11 of 76 the Vibrance® label, the potato seed piece rotational crop restriction paragraph should be revised
to read:

Following potato seed pieces treated with sedaxane:

 All crops that have not been treated with sedaxane may be planted 60 days after planting
sedaxane treated seeds.

 All crops treated w ith sedaxane other than potato may be replanted immediately.

 No sedaxane treated potato seeds may be planted for a 12

- month period following planting of sedaxane treated potato seed pieces.

This change should be made under both the “Rotational Crop Restrictions” and “Seed Bag Label Requirements” sections of the Vibrance® label.

3.4 Anticipated Exposure Pathways

The Registration Division has requested an assessment of human health risk to support the proposed new use of sedaxane on c otton and s ugar beet (not allowed on sugar beets grown for seed
production)

. Humans may be exposed to sedaxane in their diet r esulting from residues present in foods grown from sedaxane treated seeds. Also

, based on the proposed uses, it is possible that
sedaxane might reach water resources

, potentially resulting in residues in drinking water. There
are no residential uses of sedaxane , so exposure in residential and non

- occupa tional settings is

not expected

. In an occupational setting, applicators may be exposed while handling the pesticide prior to application, as well as during application. There is also potential for exposure to planters who are handling treated seeds. P ostapplication exposures following the planting of
sedaxane

- treated seeds are unlikely because sustained levels of contact with trea ted seed s after planting are not expected. This assessment consider s cancer and non

- cancer risks associated
with the proposed uses of sedaxane

.

3.5 Consideration of Environmental Justice

Potential areas of environmental justice concerns, to the extent possible, were considered in this human health risk assessment, in accordance with U.S. Executive Order 12898, "Federal Actions to Address Environmental Justice in Minority Populations and Low

- Income Population s," ( http://www.eh.doe.gov/oepa/guidance/justice/eo12898.pdf

. As a part of every pesticide risk assessment, OPP considers a large variety of consumer subgroups according to well

- estab lished procedures. In line with OPP policy, HED estimates risks to population subgroups from pesticide exposures that are based on patterns of that subgroup’s food and water consumption, and activities in and around the home that involve pesticide use in a residential setting.
Extensive data on food co nsumption patterns are compiled by the USDA under the Continuing Survey of Food Intake by Individuals (CSFII) and/or the CDC under the National Health and Nutrition Examination Survey/What We Eat in America (NHANES/WWEIA), and are used in pesticide risk assessments for all registered food uses of a pesticide. These data are analyzed and categorized by subgroups based on age, season of the year, ethnic group, and region of the country. Additionally, OPP is a ble to assess dietary exposure to smaller, specialized subgroups and exposure assessments are performed when conditions or circumstances warrant. Whenever appropriate, non

- dietary exposures based on home use of pesticide products and associated risksSedaxane (129223) Human Health Risk Assessme nt D419897, D421932

Page 12 of 76 for adult applicators and for toddlers, youths, and adults entering or playing on treated areas
post

- application are evaluated. Further considerations are currently in development as OPP has committed resources and expertise to the development of specialized software and models that consider exposure to bystanders and farm workers as well as lifestyle and traditional dietary patterns among specific sub

- groups.

4.0 Hazard Characterization and Dose

- Response Assessment

4.1 Toxicology Studies Available for Analy sis

Based on the proposed use pattern, all required studies for sedaxane have been submitted. The available toxicology database is sufficient for assessing the toxicity and characterizing the hazard of the chemical. The available toxicology studies for se daxane are listed in Table A.1 in Appendix A.

A 28

- day rat dietary toxicology study was conducted using the trans isomer, the cis isomer, and
a 1:1 mix of the isomers. Under the conditions of the study, the three sedaxane preparations were similar toxicologically and caused similar qualitative effects ( i.e., decreased body weight, increased liver weight, increased cholesterol, etc

. ). Trans

- sedaxane was considered to be slightly
more toxic than cis

- sedaxane; however, all of the major toxicology studies made use of SYN524464, which corresponds to commercial technical sedaxane (approximately 6:1 trans to
cis isomer ratio). Thus, ther e are no concerns regarding the applicability of the toxicology
database.

Based on a weight of evidence (WOE) approach, the Hazard and Science Policy Council ( HASPOC ) recommended that a sub

- chronic inhalation toxicity study is not needed for sedaxane (TXR No. 0056647 , A. Dunbar, 15

- MAY

- 2013 )

. This approach considered all of the available hazard and exposure information for sedaxane, including (1) the physical/chemical pro perties and low volatility (1.7 × 10

- 7 Pa at 25  C) of sedaxane; (2) the low acute inhalation toxicity of sedaxane; and (3) using an oral PoD and equivalent inhalation toxicity, occupational handler MOEs were > 11,000 [corn use rate for smut control ]

.

4.2 Absorption, Distribution, Metabolism, & Elimination (ADME)

The oral absorption of sedaxane was estimated following a single gavage administration at low
and hi gh dose levels (1 or 80 mg/kg ) to bile duct

- cannulated rats. The absor ption of sedaxane
was similar b etween genders and at both doses, with a range of 87

- 94 % ( 14 C

- pyrazole and 14 C

phenyl radiolabels).

Whole body autoradiography showed that the administered radioactivity was distributed widely throughout the internal organs after 5 hours; after 24 hours

, levels of total radioactivity had decreased markedly in all tissues. Peak tissue concentrations were observed at one hour, with the highest concentrations of radioactivity present in the liver, kidney and fat. Elimination half

lives for tissue depletion were between 0.1 and 3.2 days. Maximum plasma concentrations of total radioactivity were achieved at 1

- 6 hours post dose and declined with estimated terminal
half

- life values ranging from 21

- 40 hours for blood.Sedaxane (129223) Human Health Risk Assessme nt D419897, D421932

Page 13 of 76 Sedaxane was extensively metabolized in the rat via demethylation, hydroxylation, oxidation and conjugation via hydroxylated metabolites, and metabolites formed by cleavage of the terminal cyclopropyl moiety. There were no major gender or dose related differences appa rent in the qualitative metabolite profile for sedaxane. Little evidence of any cleavage of the molecule between the phenyl and pyrazole moieties was measured. The phenolic and hydroxy metabolites of sedaxane and desmethyl sedaxane all demonstrated conju gation with glucuronic acid, sulphate and glutathione.

The routes and rates of excretion were similar in rats of b oth genders and in both dose groups, with a range of 96

- 105 % by seven days. The major route of excretion was via th e feces accounting for 75

- 83 % and urinary excretion rangi ng from 12

- 20 %. In total, radioactive
residues in tissues accounted for <0.1% of the dose and the residual carcass accounted for <0.2% of the dose after 7 days.

In a repeated dose study (1 mg/kg/day) in the rat

, mo st tissue concentrations either attained or

were approaching steady state levels after the last of 14 doses to male rats. Following the cessation of dosing, all tissue concentrations declined, with no evidence of persistence. The
elimination half

- lives for tissue depletion were variable and ranged from 2 days for plasma to 33 days for the spleen.

4.2 .1 Dermal Absorption

The d ermal absorption is low ≤8%, based on the findings from an in vivo dermal penetration study in rats. F ollowing a 6 hour exposure to a test material preparation equivalent to a

1/20 aqueous dilution of sedaxane end

- use product, d ermal absorption was 2.69% of the initial
dose after 6 hou rs and 1.67% after 120 hours. F ollowing a 6 hour exposure to a test material preparation equivalent to a 1/200 aqueous dilution, dermal absorption represented 8.05% of the
dose after 6 hours and 6. 92% after 120 hours. The conservative assumption is that the dermal absorption of sedaxane is 8.0% using dilutions similar to the end

- use products. A comparison of the NOAELs from the rat dermal study with the rat developmental study of similar duration, supports that the dermal absorption is less than 10% ( i.e., NOAELs >1000 and 100 mg/kg/day, respectively).

4.3 Toxicological Effects

Sedaxane is a pyrazole carboxamide fungicide proposed for use as a seed treatment. The pesticidal mode of action of this group of fungicides is inhibition of succinate dehydrogenase (SDH), which is a functional part of the tricarboxylic acid cycle (TCA), the mitochondrial electron transport chain and oxidative phosphorylation. SDH is also present in mammals and is an important enzyme in oxidative energy production pathways.

Through oxidative metabolism, the mitochondria supply most of the energy in mamm als needed for normal activity, pumping ions and generating heat. Upon mitochondrial inhibition, clear biological changes include lethargy, decreased activity, muscle weakness, ion imbalances ( i.e., calcium and phosphate level alterations), hypothermia, d ecreased food efficiency and alt eredSedaxane (129223) Human Health Risk Assessme nt D419897, D421932

Page 14 of 76 mitochondrial morphology. Additionally, inhibition of the citric acid cycle can cause hypoglycemia since some Kreb's cycle substrates are utilized for glucose synthesis and cells metabolize more glucose via glycolysis to meet energy demands. Mitochondrial inhibition can also cause glycogen depletion to generate glucose. All of these toxicological effects were
observed in animals treated with sedaxane and the mammalian effects are consistent with the pesticidal mode of action.

The rat is the most sensitive species tested and the main target tissue for sedaxane is the liver, with effects seen in several species. Acute, sub

- chronic and chronic oral toxicity studies have been conducted in the rat, mouse, rabbit and dog. Liver effects include hypertrophy, pigmentation, vacuolation, and darkened livers. However, based on the ability of sedaxane to inhibit energy production, the reductions of rearing, grip strength and muscle tone suggest that sedaxane also affects periphe ral tissues. Reductions in heart mass were reported in females in
the 90

- day rat study (absolute and relative heart weights in a mitochondrial

- rich tissue). Several studies showed reductions in bodyweight and food consumption. Sedaxane also caused thyro id hypertrophy/hyperplasia. At high doses, studies in three species manifested effects such as decreases in spleen and thymus weights (dog and rat), plus significant decreases in lymphocytes, white blood cells ( WBC s) and monocytes (dog and mouse).

Sedaxa ne produced no adverse effects in rat fetuses in developmental toxicity studies at maternally toxic doses. However, in the rabbit developmental study , fetal toxicity was observed at the same dose as the dams ( i.e., decreased fetal weights, increased abort ions, increased unossified sternebrae and 13th rudimentary ribs). In rat reproduction studies, offspring effects occurred at the same doses causing parental effects, thus there was no quantitative increase in sensitivity in rat pups in the reproductive toxicity study. There were no single

- dose effects identified in the developmental toxicity studies in rats or rabbits, including the abortions in the rabbit developmental study which occurred at gestation day 28 ( GD 28 )

. There are also indications of rep roductive toxicity in rats, as decreases in follicle count and changes in testes or ovary weight. However, these effects did not result in reduced functional fertility in the rat. Syngenta has submitted updated ovary staging data for the follicle and corp ora lutea counts for the intermediate 200 and 500 ppm doses ( D421932), which are listed in Appendix A4 for the reproduct ion study. The updated data did not alter the LOAEL value of 143 mg/kg/day for the
female reproductive toxicity , but increased the femal e reproductive NOAEL to 46 mg/kg/day (previously 14.3 mg/kg/day)

. No evidence of specific neurotoxicity was observed in several studies. Sedaxane caused decreased activity, decreased muscle tone, decreased rearing and decreased grip strength in the ACN an d SCN studies; however, there were no supportive neuro

histopathology in any study, even at the highest doses tested. The Agency has a low concern for neurotoxicity based on these apical endpoints and t he effects observed are consistent with a
mitochondri al inhibitor to decrease energy production. Immune system toxicity was negative by
the T

- cell dependent antigen response ( TDAR ) assay in the mouse. Sedaxane did not display systemic effects in the 28

- day dermal study, even at the limit dose of 1000 mg/kg /day.

Sedaxane causes tumors in the liver (rat and mice), and in the uterus and thyroid (rats). Sedaxane increased liver adenomas and thyroid tumors in male rats. The liver adenomas were not supported by corroborative histopathology, but the thyroid tumors wer e supported by increased follicular cell hyperplasia. In female rats, sedaxane increased both uterine adenomasSedaxane (129223) Human Health Risk Assessme nt D419897, D421932

Page 15 of 76 and adenocarcinomas, but no corroborative uterine histopathology findings were present. In male mice, liver adenomas and carcinomas were increa sed, however without supporting liver histopathology. Sedaxane was negative in all five mutagenicity studies; however, chromosomal aberrations were observed at cytotoxic concentrations in one in vitro study , thus there was no mutagenic concern for sedaxan e

. In accordance with the EPA’s Final Guidelines for Carcinogen
Risk Assessment (March, 2005), the CARC classified s edaxane as “Likely to be Carcinogenic to
Humans”. This classification is based on the presence of uterine tumors in female rats and liver

t umors in male mice, as well as weak evidence of thyroid follicular cell tumors and liver tumors in male rats, at doses that were adequate to evaluate the carcinogenic potential of sedaxane. A
linear low

- dose extrapolation model (Q 1 *) will be used for quan tification of cancer risk to
humans , with a Q 1 * = 4.64 × 10

- 3 (mg/kg/day)

- 1

.

Sedaxane has low acute toxicity by the oral, dermal, and inhalation routes. It is not a dermal sensitizer, causes no skin irritation and only slight eye irritation. Increased s erum phosphate levels were measured in several studies (i.e. the 13

- week and chronic rat studies), consistent with sedaxane’s inhibition of oxidative phosphorylation ( i.e., phosphorylation of adenosine diphosphate (ADP) to a denosine

- 5'

- triphosphate ( ATP) via the electron transport chain). Ion imbalances in general can be a consequence of decreased energy production via decreased ATP

powered ion pump activity. Many of the listed effects of sedaxane are consistent with decreased mitochondrial energy produc tion and metabolism ( i.e., hypothermia, lethargy, decreased food efficiency, etc .). However, at higher doses, some effects of sedaxane may also be explained by

non

- specific and generalized toxicity not associated with succinate dehydrogenase inhibition.

T he CSCD465008 metabolite was negative for genotoxicity testing and is not expected to be more toxic than the parent. However, the 28

- day study for this metabolite was performed in the
rat while the 28

- day study for sedaxane was performed in the mouse.

4. 4 Safety factor for Infants and Children (FQPA Safety Factor)

The FQPA factor for increased susceptibility to infant and children is reduced to 1X based on the following considerations:

1) The toxicology and exposure data bases for sedaxane are complete and adequate for assessing increased susceptibility under FQPA; 2) In the rat, no adverse effects in fetuses were seen in developmental toxicity at maternally toxic doses. In the rabbit, fetal toxicity was observed at the same doses as the dam ( increased unossi fied sternebrae and 13th rudimentary ribs a nd a decrease in fetal weights of

- 9% and increased abortions ) . In the dam, at the same doses, the effects were decreased body weight, decreased body weight gain, reduced food consumption, and
decreased defecatio n. In reproduction studies, offspring effects occurred at the same doses causing parental effects; thus, there was no quantitative increase in sensitivity in rat pups. The LOAELs and NOAELs for the developmental and reproduction studies were clearly defi ned; 3) T here are no specific concerns for neurotoxicity as observed effects were likely secondary to inhibition of mitochondrial energy production caused by sedaxane; 4) A developmental neurotoxicity study is not required; 5) There are no residual uncertainties in the toxicology database; andSedaxane (129223) Human Health Risk Assessment D419897, D421932

Page 16 of 76 6) Exposure assessments are conservative and will not underestimate exposure.

4.4 .1 Completeness o f the Toxicology Database

T he toxicology database for sedaxane is considered complete for evaluating and characterizing its toxicity, assessing of children’s susceptibility under FQPA and selecting endpoints for the exposure pathways of concern.

4.4.2 Evidence of Neurotoxicity

Acute oral (gavage) and sub-chronic oral (dietary) neurotoxicity studies in rats were conducted on the sedaxane technical product. No evidence of specific neurotoxicity was seen in these
studies. Sedaxane caused changes in apical endpoints such as decreased activity, decreased muscle tone, decreased rearing and decreased grip strength in the ACN and SCN studies. There was no corroborative neuro-histopathology demonstrated in any study, even at the highest doses tested ( i.e., 2000 mg/kg/day) and the results of the ACN and SCN studies are consistent with inhibition of mitochondrial energy production by sedaxane. Based on its chemical structure, its pesticidal mode of action and lack of evidence of neuro-histopathology in any acute and repeated-dose toxicity studies, sedaxane does not demonstrate potential for neurotoxicity. Since sedaxane did not demonstrate susceptibility to the young or specific neurotoxicity, a developmental neurotoxicity (DNT) study is not required.

4.4.3 Evidence o f Sensitivity/Susceptibility in the Developing or Young Animal

There is no evidence for increased susceptibility following pre-and or post-natal exposures to sedaxane based on effects seen in developmental toxicity studies in rabbits or rats. In range finding and definitive developmental toxicity studies in rats, neither quantitative nor qualitative evidence of increased susceptibility of fetuses to in utero exposure to sedaxane was observed. In these studies, there were no single-dose effects. There was no evidence of increased susceptibility in a two-generation reproduction study in rats following pre- or post-natal exposure
to sedaxane. There is no evidence of neuropathology or abnormalities in the development of the fetal nervous system from the available toxicity studies conducted with sedaxane. Clear NOAELs/LOAELs were established for the developmental effects seen in rats and rabbit s aswell as for the offspring effects seen in the two-generation reproduction study. The doseresponse relationship for the effects of concern is well characterized. The NOAEL used for the acute dietary risk assessment (30 mg/kg/day), based on effects observed in the ACN study, is protective of the developmental and offspring effects seen in rabbits and rats with the NOAELsof 100-200 mg/kg/day. Based on these considerations, there are no residual uncertainties for preand/or post-natal susceptibility; thus, a DNT study is not required.

4.4.4 Residual Uncertainty in the Exposure Database

There is no residual uncertainty in the exposure database for sedaxane with respect to dietary (food and water) exposure. Moreover, there are no registered residential uses of sedaxane in the

U.S.Sedaxane (129223) Human Health Risk Assessme nt D419897, D421932

Page 17 of 76 A complete database with respect to both the nature and magnitude of residues expec ted in food
has been provided. The dieta ry food exposure assessment s are highly conservative (acute) or only partially refined (chronic), result ing in high

- end estimates of dietary food exposure. Also

, highly conservative, modeled drinking estimates of exposure were inc luded in the assessments

, and the water contribution was found to be the primary contributor to dietary exposure. Actual exposures and risks from sedaxane in food and drinking water are likely to be far lower than
estimated in this risk assessment.

4. 5 Toxicity Endpoint and Point of D eparture Selections

4.5.1 Dose

- Response Assessment

Toxicity endpoints and points of departure ( PoD s) for dietary exposure scenarios to sedaxane are summarized below. Detailed description of the studies used as a basis f or the selected endpoints are presented in Appendix A.

An acute RfD is based on a NOAEL of 30 mg/kg/day selected from an ACN study in rats (LOAEL=250 mg/kg) based on clinical signs of toxicity ( reduced activity, decreased rearing, initial inactivity, pi loerection, ruffled fur and recumbency, decreased body weight, body weight gains and food consumption in males; plus weakened condition, swaying gait, decreased activity, reduced muscle tone and decreased locomotor activity & rearing in females)

. The weak ened condition, swaying gait and decreased activity were observed on days 2

- 7, while the other effects
occurred on day 1. The acute dietary dose and endpoint for the general population is protective
for females 13+

. The reproductive LOAEL for the reprodu ction study is 143 mg/kg/day based
on decreased follicle counts. The NOAE L for the ACN study is 30 mg/kg: a three

- fold lower
dose. The reduced follicle counts did not result in a f unctional decrease in fertility; thus

, the ACN study PoD is considered protective. An uncertainty factor of 100x (10x to account for interspecies extrapolation and 10x for intraspecies variation) was applied to the aRfD.

For acute dietary analysis of females 13+, no study was identified with an appropriate endpoint for this group. There were no single

- dose effects identified in the developmental toxicity studies in rats or rabbits, including the abortions in the rabbit developmental study which occurred at GD

28. The acute dietary PoD for general populati on utilizing the ACN study is protective for this
scenario.

The ACN study in rats was also considered appropriate for endpoint selection for the short

- and
intermediate

- term inhalation exposure scenarios.

A chronic RfD of 0.11 mg/kg/day (NOAEL=11 mg/kg /day) was selected from a chronic toxicity/carcinogenicity feeding study in rats (LOAEL=67/86 mg/kg/day) based on liver and thyroid effects

. In females, it was based on decreased body weight and body weight gain, increased liver weight and thyroid effects

. An uncertainty factor of 100x (10x to account for interspecies extrapolation and 10x for intra

- species variation) was applied to the cRfD.

Because sedaxane has no residential uses, no incidental oral endpoints were selected

.Sedaxane (129223) Human Health Risk Assessme nt D419897, D421932

Page 18 of 76 The 28

- day dermal study had no systemic effects at the limit dose of 1000 mg/kg/day. Therefore, non

- cancer dermal risk assessments are not required for sedaxane.

4.5.2 Recommendation for Combining Routes of Exposures for Risk Assessment

As part of conducting a h uman heal th risk assessment, HED cons iders risks from individual routes of exposure (oral, dermal, and inhalation). Additionally, HED must assess aggregate risks from dietary and residential exposures . In order to conduct an aggregate risk assessment a
determinat ion is made if it is appropriate to combine across routes of exposure and aggregate dietary risks with residential (non

- occupational) risks. Because there are no residential uses for
sedaxane

, the dietary and aggregate assessments are identical

. For the occupational non

- cancer risk assessment, it is not possible to combine routes of exposure due to the lack of a dermal toxicity endpoint. However, for the occupational cancer risk assessment, dermal and inhalation exposures should be combined prior to comp arison to the linear slope factor selected as the cancer endpoint.

4.5.3 Cancer Classification and Risk Assessment Recommendation

In accordance with the EPA’s Final Guidelines for Carcinogen Risk Assessment (March, 2005),
the CARC classified sedaxane as “Likely to be Carcinogenic to Humans”. This classification is based on the presence of uterine tumors in female rats and liver tumors in male mice, as well as
weak evidence of thyroid follicular cell tumors and liver tumors in male rats, at doses that wer e adequate to evaluate the carcinogenic potential of sedaxane. There is no mutagenic concern for
sedaxane. In the absence of mode of action data, the CARC recommended low

- dose, linear extrapolation for risk assessment with a Q 1 * value of 4.64 × 10

- 3 (mg/k g/day)

- 1

.

4. 5

. 4 Summary of Points of Departure and Toxicity Endpoints Used in Human Risk
Assessment

Table 4.5.4 summarizes the toxicological doses and endpoints selected for use in the human
health risk assessment for sedaxane

.Sedaxane (129223) Human Health Risk Assessme nt D419897, D421932

Page 19 of 76 Table 4.5.4. Summary of Toxicological Doses and Endpoints for Sedaxane for Use in Human Health Risk
Assessments

Exposure/
Scenario Point of

Departure Uncertainty/FQPA

Safety Factors RfD, PAD,

Level of
Concern for
Risk
Assessment Study and Toxicological Effects

Acute Dietary (All populations, including
children and

women 13

- 49 years of age) NOAEL=

3 0 mg/kg/day UF A = 10 x

UF H =10 x FQPA SF = 1x Acute RfD =

0.3 0 mg/kg/day

aPAD = 0.30 mg/kg/day Rat ACN Study

NOAEL=30 mg/kg LOAEL=250 mg/kg based on reduced activity, decreased rearing, initial inactivity, piloerection, ruffled fur and recumbency, decreased BW, decreased BWG and food consumption (males). In females, weakened condition, swaying gait, decreased activity, reduced muscle

tone

, an d decreased locomotor activity
and rearing

. The weakened condition, swaying gait and decreased activity were observed on days 2

- 7, while the other effects were on day 1.

Chronic Dietary (All Populations) NOAEL=

11 mg/kg/day UF A = 10 x

UF H =10 x FQPA SF = 1 x Chronic RfD =

0.11 mg/kg/day

cPAD = 0.11 mg/kg/day Chronic Rat Study

NOAEL= 11/14 mg/kg bw/day ♂/♀ LOAEL = 67/86 mg/kg bw/day ♂/♀,

in males based on decreased hind limb grip strength increased liver weight, increased incidences of hepatocyte hypertrophy and eosinophilic foci, and thyroid follicular cell hypertrophy, basophilic colloid, epithelial desquamation and increased phosphate levels (♂). In females, it was based on decreased body weight and body weight gain, increased liver weight and the same thyroid histopathology noted
above for males. Dermal, All
Durations Not applicable as t he 28

- day dermal study had no systemic effects at the limit dose of 1000

mg/kg/day.

Incidental Oral, All
Durations Not applicable as there are no residential uses of sedaxane.Sedaxane (129223) Human Health Risk Assessme nt D419897, D421932

Page 20 of 76 Table 4.5.4. Summary of Toxicological Doses and Endpoints for Sedaxane for Use in Human Health Risk
Assessments

Exposure/
Scenario Point of

Departure Uncertainty/FQPA

Safety Factors RfD, PAD,

Level of
Concern for
Risk
Assessment Study and Toxicological Effects

Inhalation

, Short

- Term Term (1

- 30 days )
and
Intermediate

Term (1

- 6
months ) NOAEL=30

mg/kg/day UF A = 10x

UF H = 10x FQPA SF= 1x LOC for MOE

= 100 ACN Study

NOAEL=30 mg/kg LOAEL = 250 mg/kg bw , based on reduced activity, decreased rearing, initial inactivity, piloerection, ruffled fur and recumbency, decreased body weight, body weight gains and food consumption (♂); plus weakened condition, swaying gait, decreased activity, reduced muscle tone and decreased locomotor activity & rearing (♀). The weakened condition, swaying gait and decreased activity were observed on days 2

- 7, while the other effects were on day 1.

Inhala tion, Long

- Term (>6 months) A long

- term inhalation scen a rio is not applicable for seed treatment uses

.

Cancer (oral, dermal, inhalation) Classification: “Likely to be Carcinogenic to Humans” based on significant tumor increases in

two adequate rodent carcinogenicity studies. Q 1 *= 4.64x10

- 3 (mg/kg/day)

- 1

Point of Departure ( PoD ) = A data point or an estimated point that is derived from observed dose

- response data and used to mark the beginning of extrapolation to determine risk associated with lower environmentally relevant human exposures. NOAEL = no observed adverse effect level. LOAEL = lowest observed adverse effect level. UF = uncertainty factor. UF A = extrapolation from animal to human (interspecies). UF H = potential variation in sensitivit y among members of the human population (intraspecies). FQPA SF = FQPA Safety Factor. PAD = population adjusted dose (a = acute, c = chronic). RfD = reference dose. MOE = margin of exposure. LOC = level of concern

.

5.0 Dietary Exposure and Risk Assessment

5.1 Metabolite/Degradate Residue Profile

5 .1.1 Summary of Plant and Livestock Metabolism Studies

5.1.1.1 Plant Metabolism Studies

Plant metabolism data were submitted for corn , wheat, soybean, Swiss chard, and canola to support the re quest ed seed treatment uses of sedaxane . Studies for all commodities ref lected labeling in both the phenyl and pyrazole rings

. A pplication rates were equal to, or exaggerations of the currently proposed use rates

, and application techniques reflect the request ed use patterns

.

The metabolic pathway in wheat, soybeans

, and Swiss chard i s substantially similar. Insufficient radioactivity levels were obtained from the corn and canola samples to elucidate the metabolic pathways in these crops. Following seed treatment use of sedaxane in wheat, soybean, and Swiss
chard

, sedaxane metabolism may be summarized as follows : 1) oxidative metabolism of the phenyl and cyclopropane rings, 2) N

- demethylation of the pyrazole ring and 3) cleavage betweenSedaxane (129223) Human Health Risk Assessme nt D419897, D421932

Page 21 of 76 pyr azole and phenyl rings. Among the three crops studied, there is variation in the extent of the three reaction processes and the nat ure of the observed conjugates found

.

Because the proposed met abolic pathways for three diverse crops ( cereal grain, leafy green vegetable, and legume vegetable ) are similar, the data are adequate to define the nature of the residue in all plants. HED has determined that residue of concern in plants (primary and rotational crops) is parent sedaxane (both isomers). However , si nce the application techniques
were limit ed to seed treatment, these data will not support foliar uses of sedaxane on agricultural

crops , and separate metabolism studies will be needed should foliar uses be requested.

5.1.1.2 Livestock Metabolism Studies

Livestock metabolism studies were submitted for the hen (poultry) and lactating goat (ruminant)
for sedaxane

. Studies in both animals ref lected labeling in bot h the phenyl and pyrazole rings

.

Sedaxane is extensively metabolized in the hen and lactating goat. The metabolic pathways in poultry and ruminants appear similar. The principal routes of metabolism are oxidation resulting in hydroxylation of the phenyl ring or at the cyclopropane moiety. Additionally the same
oxidations are observed fo llowing demethylation of sedaxane. Overall results also showed that the biotransformation pathway of sedaxane in ruminants and poultry is similar to that observed in
the rat.

The submitted livestock metabolism studies adequately address the requirement t o elucidate the
nature of the residue in livestock for sedaxane

. HED has determined that residue of concern in
livestock is parent sedaxane (both isomers) for tolerance enforcement , while for risk assessment the residue definition is parent sedaxane plus CSCD658906.

5.1.2 Summary of Environmental Degradation Drinking Wat er Memo, D382528, R. Bohaty, 12/21/11

Laboratory data suggest that in the environment sedaxane is persistent

. Data indicate that
sedaxane is only susceptible to degradation via aerobic soil metabolism ( laboratory soil half

- life
296

- 400 days based on single first order kinetics) and photolysis (laboratory half

- life of 46 days for aqueous photolysis and 253 days for soil photolysis )

. A erobic biodegradation of sedaxane in
soil does not follow single first order kinetics. In general, sedaxane concentrations decrease over the first 100 days; however, after 100 days, sedaxane concentrations remain steady (approximately 50% of the applied radioactivity) through at least 365 days. Hydr olysis, anaerobic soil and aquatic transformation, and aerobic aquatic metabolism are not expected to
contribute to the dissipation of sedaxane in the environment. Terrestrial field dissipation data (DT 50 value 114

- 132 days) suggest sedaxane will persist in the environment

, consistent with laboratory metabolism and photolysis data.

5.1.3 Comparison of Metabolic Pathways

The metabolism of sedaxane in the rat is detailed in Section 4.2 and the metabolism in plants and
livestock is discussed in Section 5.1. 1

. T he metabolic profile in plants is similar in cereal grains,Sedaxane (129223) Human Health Risk Assessme nt D419897, D421932

Page 22 of 76 leafy greens, and legumes. Metabolism in the rat and livestock (ruminants and poultry) is
similar . The primary difference in metabolism between plants and animals is that in plants some
cle avage of the bond between the pyrazole and phenyl rings was observed, while this was not
seen in animals. However, due to the very low levels of these metabolites, combined with low concern regarding their toxicity, no additional studies are needed to fur ther investigate these plant metabolites.

5.1.4 Residues of Concern Summary and Rationale
ROCKS Memo, D387015

, I. Negrón

- Encarnación , 11/10 /2011 ROCKS Memo, D4 06945

, E. Holman, 12/1 9 /201 2

The HED Residues of Concern Knowledge base Sub

- committee (ROCKS) considered the available data on the nature and magnitude of residues in sedaxane and concluded that for plant
seed treatment uses , the parent compound only (sum of cis and trans isomers) should be included
for tolerance enforcement and dietary (food) risk assessment. For livestock, the residue of concern for tolerance enforcement is parent sedaxane; for risk assessment, parent and CSCD658906 comprise the residues of concern.

Based on toxicity data provided for the pyr azole metabolites CSCD465008 and CSAA798670, sedaxane is consistently more toxic than these metabolites in acute oral toxicity, succinate dehydrogenase inhibition, sub

- chronic and developmental toxicity studies at doses < 500 mg/kg. Additionally, as carci nogenicity potential is considered to be mainly due to parent sedaxane, the pyrazole metabolites are of reduced toxicological concern. Although the pyrazole metabolites may reach drinking water sources due to their mobility and significant half

- lives, the risk assessment for sedaxane is expected to be protective of exposures to these
metabolites. Therefore, the 2012 ROCKS meeting recommended that CSCD465008 and CSAA798670 no longer be considered residues of concern in drinking water , leaving only parent

s edaxane, and metabolites CSCD668094 and CSCD668095 as the residues of concern in the drinking water risk assessment

. This decision applies only to seed treatment uses.

The residues of concern for sedaxane are summ arized in T able 5.1.4, below.

Table 5. 1. 4. Summary of Metabolites and Degradates to be included in th e Risk
Assessment and Tolerance Expression 1

Matrix Residues included in Risk Assessment Residues included in Tolerance Expression

Plants Both isomers of parent sedaxane Both isomers of parent sedaxane

Livestock Both isomers of parent s edaxane plus
CSCD658906 Both isomers of parent sedaxane

Drinking Water Both isomers of parent sedaxane plus
CSCD668094 and CSCD668095 Not Applicable

1 The residues of concern identified in this table apply only to seed treatment uses.

2 Sedaxane is a mixture of cis isomer 2’

- [(RS,2RS )

- 1,1’

- bicycloprop

- 2

- yl]

- 3

- (difluoromethyl)

- 1

- methylpyrazole

- 4

- carboxanilide
and trans isomer 2’

- [(RS,2SR)

- 1,1’

- bicycloprop

- 2

- yl]

- 3

- (difluoromethyl)

- 1

- methylpyrazole

- 4

- carboxanilide. CSCD658906 is N

- {2

- [(1 R ,2 S )

- 1,1'

- bi(cyclopropyl)

- 2

- yl]phenyl}

- 1

- methyl

- 3

- (trifluoromethyl)

- 1 H

- pyrazole

- 4

- carboxamide. CSCD668094 is N

- [2

-Sedaxane (129223) Human Health Risk Assessme nt D419897, D421932

Page 23 of 76 (3

- cyclopropyl

- 1,3

- dihydroxypropyl)phenyl]

- 3

- (difluoromethyl)

- 1

- methyl

- 1 H

- pyrazole

- 4

- carboxamide ; and CSCD668095 is 3

- [2

- ({[3

- (difluoromethyl)

- 1

- methyl

- 1 H

- pyrazol

- 4

- yl]carbonyl}amino)phenyl]

- 3

- hydroxypropanoic acid

.

5 .2 Food Residue Profile

D 423822 & D422929

, W. Donovan, 12 / 1 9 /1 4 D425112, W. Donovan, 01/20/15

The available seed treatment data on the metabolism of sedaxane in wheat, soybean, and Swiss chard demonstrate that residues are generally low, but do translocate throughout the plants. The highest residues are generally found in the foliage or forage portions of plan ts, and not in the seeds or grains. Crop field trial residue data were consistent with the results of the plant metabolism studies. Specifically, the magnitude of the residue studies showed no quantifiable residues of sedaxane in any plant seeds or grain s, but low level residues were found in some
livestock feedstuf

fs associated with these plants

.

Adequate residue chemistry data have been provided for sedaxane. S ufficient f ield trials with appropriate geographic representation were submitted

. Twelve cotton trials in the U.S. were conducted at the maximum label rate and showed no detectable sedaxane residues in seed samples. Three of these field trials collected cotton gin byproduct samples using stripper harvesting methods; no detectable sedaxane res idues were found in cotton gi n byproduct samples

. Similarly , twelve sugar beet trials in the U.S. were conducted at the maximum label rate and showed no detectable sedaxane residues in roots or tops. Thus, the field trial studies support LOQ level tolera nces for cotton seed, cotton gin byproducts, and sugar beet roots.

Two cotton processing studies were conducted to determine if sedaxane residues concentrate in meal, hulls, and refined oil processed from cotton seeds . Following treatment of cotton seed at a target exaggerated rate of 0.0825 mg/seed (5 × maximum label rate), residues in cotton seeds and
all cotton processed fractions were below the method LOQ

. Similarly, two sugar beet processing
studies were conducted to determine if sedaxane residu es concentrate in refined sugar, drie d pulp and molasses from sugar beet roots. Following treatment of sugar beet at a target exaggerated

rate of 0.225 mg/seed (3 × maximum label rate), residues in all sugar beet processed fractions

were below the method L OQ

. Therefore, separate tolerance s are not needed for any processed commodities from cotton or sugar beet.

Data analyses employed validated analytical methods and are supported by adequate storage stability data. HED determined that the registered and p roposed seed treatment uses of sedaxane are classified as 180.6 (a) (3), no reasonable expectation of finite residues with respect to residues in livestock commodities. Confined rotational crops studies show that the metabolism of sedaxane in rotated crop s is similar to that in primary crops, although relatively less parent and more pyrazole

- derived metabolites were found, particularly at PBIs longer than 30 days. Limited rotational crop field trials demonstrate that 30

- day PBIs are appropriate for rotati onal crops planted after a crop grown from sedaxane treated seed; except after treated potato seed pieces, where a 60

- day PBI is needed for rotational crops. Registered crops may be replanted immediately, except in the case of potato, where a 12

- month int erval is recommended.Sedaxane (129223) Human Health Risk Assessme nt D419897, D421932

Page 24 of 76 5.3 Water Residue Profile Drinking Water Memo, D382528, R. Bohaty, 12/21 /11 Drinking Water Memo, D405391 & D407956, R. Bohaty & J. Hetrick, 03/18 /13 Drinking Water Memo, D419976, R. Bohaty, 10/23/14

T here are no monitoring data currently available for sedaxane or its residues of concern in drinking water

. E stimated drinking water concentrations (EDWCs) were generated using
computer model ing methods . T he screening model FIRST (FQPA Index Reservoir Screening
Tool ) was used to cal culate the surface water EDWCs

. G roundwater EDWCs were c alculated using the PRZM

- G roundwater (PRZM

- G W Version 1.0, 12/11/2012 )

.

Maximum application rates for sedaxane as a high

- end estimate of exposure in drinking water were modeled based on the proposed labels

. In accord with recommendations of the ROCKS, total toxic residue levels were modeled, to include all the drinking water residues of concern, namely, b oth isom ers of parent sedaxane plus CSCD668094 and CSCD668095

. However, as
CSCD668094 and CSCD668095 were only observed in aquatic photolysis studies, these residues were only considered as part of the surface water modeling. Surface water EDWCs were
corrected for a pe rcent cropped area (PCA) of 0.91

. The maximum s urface and ground water
EDWCs for use in the human health risk assessment for sedaxane are shown in Table 5.3

. The ground water values were selected for use in the dietary exposure assessment since t hey were higher than the surface water values.

T able 5.3. Maximum Estimate d Surface Water and Ground Water Concentrations for Sedaxane and Major Degradates 1

. Scenario Surface Water Conc., ppb 2 Ground W ater Conc., ppb 3

Acute 4.1 22.0

Chronic & Cancer 1.2 19.3

1 EDWCs include residues of concern identified by the ROCKS

. Highest value for use in risk assessment is shown in bold.

2 From the FIRST model

. 3 From the PRZM

- GW model assuming sedaxane potato treatment every year.

5.4 Dietary Risk Assessment Dietary Exposure Memo, D423821, W. Donovan, 11 /12 /1 4

5. 4.1 Description of Residue Data Used in Dietary Assessment

The acute dietary risk assessment used tolerance level residues for all commodities included in
the assessment . The chronic and cancer dietary risk assessments used anticipated residues for all
commodities.

5.4.2 Percent Crop Treated Used in Dietary Assessment D389267, C. Doucoure and T. Chandgoyal, 22

- JUN

- 2011 D409503, T. Chandgoyal and C. Doucoure, 29

- APR

- 2013

The acute dieta ry risk assessment assumed 100% crop treated for all commodities included in the

assessment.Sedaxane (129223) Human Health Risk Assessme nt D419897, D421932

Page 25 of 76 For chronic and cancer dietary exposure assessment, 100% crop treated was assumed for all commodities except for soybeans (51%) and wheat (32%), which incorpora ted average percent crop treated estimates. Average percent crop treated estimates were also used for the proposed use on potato (67%).

5.4.3 Acute Dietary Risk Assessment

A highly conservative acute dietary risk assessment was conducted which used tolerance level residues, assumed 100 percent crop treated (% CT) for all commodities and screening level
estimated drinking water concentrations (EDWCs)

. The estimated exposure (food and water) to the U.S. population and all population subgroups from the established uses and proposed new
uses of sedaxane resulted in an estimated risk equivalent to <2 % of the acute population adjusted dose (aPAD) at the 95 th percentile , see Table 5.4.6.

5.4.4 Chronic Dietary Risk Assessment

A partially refined chronic dietary assessment was conducted using anticipated residue levels, percent crop treated data, and screening

- level EDWCs. The estimated exposure (food and water) to the U.S. population and all population subgroups from the established uses and pro posed new
uses of sedaxane resulted in a n estimated risk equivalent to ≤1 % of the chronic population adjusted dose (cPAD).

5.4.5 Cancer Dietary Risk Assessment

A partially refined cancer dietary assessment was conducted using anticipated residue levels

, percent crop treated data, and screening

- level EDWCs [the same assumptions used in the chronic dietary analysis]. The estimated exposure of the general U.S. population to sedaxane is 0.000 427 mg/kg/day. Multiplying the Q 1 * of 4.64 × 10

- 3 (mg/kg/day )

- 1 by the exposure value results in a
cancer risk estimate of 2 × 10

- 6 to the U.S. population. At this level of refinement, drinking
water accounted for 95 % of the total dietary exposure to sedaxane.Sedaxane (129223) Human Health Risk Assessme nt D419897, D421932

Page 26 of 76 5.4.6 Summary Table

Table 5.4

. 6. Summary of Dietary (Food and Drinking Water) Exposure and Risk for Sedaxane. 1

Population Subgroup Acute Dietary ( 95th Percentile) Chronic Dietary Cancer

Dietary Exposure (mg/kg/day) % aPAD Dietary Exposure (mg/kg/day) % cPAD Dietary Exposure (mg/kg/day) Risk

General U.S. Population 0.001286 < 1 0.000427 < 1 0.000 427 2.0 × 10

- 6

All Infants (< 1 year old) 0.003876 1 .3 0.001076 1 .0

N/A N/A Children 1

- 2 years old 0.002074 < 1 0.000636 < 1

Children 3

- 5 years old 0.001699 < 1 0.000543 < 1

Children 6

- 12 years old 0.001290 < 1 0.000391 < 1

Youth 13

- 19 years old 0.001069 < 1 0.000318 < 1

Adults 20

- 49 years old 0.001238 < 1 0.000423 < 1

Adults 50

- 99 years old 0.001100 < 1 0.000413 < 1

Females 13

- 49 years old 0.001259 < 1 0.000420 < 1

1 Highest exposure identified in bold.

6.0 Residential (Non

- Occupational) Exposure/Risk Characterization

Residential exposures and risk are not assessed because the proposed uses of sedaxane do not involve applications by homeowners or commercial applicators in resi dentia l settings and there are no existing or proposed residential uses.

6. 1 Spray Drift

A postapplication inhalation exposure assessment is not required as exposure is expected to be negligible. Seed treatment assessments provide quantitative inhalation expo sure assessments for seed treaters and secondary handlers ( i.e.

, planters). It is expected that these exposure estimates would be protective of postapplication inhalation exposure scenarios ; risks for these scenarios
were not of concern

.

Seed treatment o perations typically utilize closed systems and do not involve spraying of pesticides. Therefore, any spray drift is expected to be negligible and included in the handler inhalation exposure assessment.Sedaxane (129223) Human Health Risk Assessme nt D419897, D421932

Page 27 of 76 7.0 Aggregate Exposure/Risk Characterization

There are no residential uses for sedaxane ; therefore the aggregate exposure and risk assessments
include acute and chronic dietary ( food and water ) only and are shown in Section s 5.4.3 and
5.4.4. There are no aggregate risk estimates of concern for the p roposed new uses of sedaxane

. Sedaxane is a member of the pyrazole carboxamide fungicides. Metabolic processes involving cleavage of the linkage between the pyrazole and phenyl rings of these compounds have the potential to produce common pyrazole

- metab olites. Indeed, confined rotational crops studies for
sedaxane , fluxapyroxad, and isopyrazam demonstrate that low levels of the following common metabolites form: CSCD465008, CSAA798670, and CSCC210616. However, due to the low levels of these compounds i n rotational crops (≤0.01 ppm), and low concerns about their potential toxicity relative to parent molecules, any risks from aggregation of exposures to these metabolites across chemicals will be insignificant.

8.0 Cumulative Exposure/Risk Characterizat ion

Unlike other pesticides for which EPA has followed a cumulative risk approach based on a common mechanism of toxicity, EPA has not made a common mechanism of toxicity finding as

to sedaxane and any other substances

. For information regarding EPA’s ef forts to determine which chemicals have a common mechanism of toxicity and to evaluate the cumulative effects of such chemicals, see the policy statements released by EPA’s Office of Pesticide Programs concerning common mechanism determinations and procedu res for cumulating effects from
substances found to have a common mechanism on EPA’s website at http://www.epa.gov/pesticides/cumulative/.

9.0 Occupational Exposure/Risk Characterization Occupational/Residential Exposure Mem o, D 423820 , S. Tadayon, 0 1 / 20 /1 5

9.1 Short

- /Intermediate

- Term Handler Risk

Occupational handler exposure to sedaxane is expected for individuals involved in commercial
seed treatment and on

- farm se ed treatment

. Occupational seed treatment primary handlers may experience short

- and intermediate

- term exposure to sedaxane while performing seed treatment
activities in commercial settings. In addition, occupational secondary handlers may experience
short

- and intermediate

- term exposure while planting sedaxane

- treated seeds. No chemical

specific handler exposure data were submitted in support of this use pattern. For assessing
commercial seed treatment and seed planting activities, unit exposure data were taken from HED ExpoSAC Policy 14: SOPs for Seed Treatment

. The amount of active ingredient handled depends on the application rate (lb ai/lb seed) and the pounds of seed treated in a day (or the pounds of seed that can be planted in a day), all of which depend upon the seed type. Amount of Seed Treated or Planted per Day (Policy 15) a nd Interim Guidance “Amount of Commercial Seed Treated Per Day ” (Policy 15.1 )

. This assessment uses t he Agricultural Handler Exposure Task Force ( AHETF ) survey ( MRID # 49185401, July 25, 2013 ) which were conducted in the
United States and Canada

. The main objective of this survey was to collect seed treatment throughput data for updating EPA HED’s Science Advisory Council for Exposure, Standard Operating Procedure Number 15, entitled Amount of Seed Treated or Planted per Day.Sedaxane (129223) Human Health Risk Assessme nt D419897, D421932

Page 28 of 76 Specifically, survey data were collected to update daily seed treatment throughput data and to characterize seed treating equipment and worker activities for eight seed types

— canola, corn,
cotton, peanut, rice, sunflower

, soybe an, and wheat. The AHETF survey (MRID # 49185401) replaces m aximum equipment capacity referenced in SOP 15

.

Q uantit ation of non

- cancer dermal exposure and risk is not required since a dermal hazard w as not i dentified for sedaxane . Only inhalation exposure and risks were quantified. The occupational inhalation exposure assessme nt was completed for commercial seed treatment
facilities

.

The proposed personal protective equipment (PPE) for sedaxane on all proposed labels requires that all mixers, loaders, applicato rs and other handlers wear long

- sleeved shirt s a nd long pants, socks plus shoes, and chemical resistant gloves (except when bagging or sewing bags of treated seeds).

Primary and Secondary Handler N on

- Cancer Risk
Short

- and intermediate

- term handler exposures and risk estimates for cotton and sugar beet (processing o nly) treatment activities are shown in Table s 9.1.1

- 9.1. 2 , below. All inhalation
risk estimates exceed an MOE of 100 and

, therefore, are not of concern.

Primary Handler Cancer Risk The following cancer risk estimate s (primary and secondary handler) are based on the maximum application rate and baseline mitigation levels

. Thus, the cancer risk estimate for commercial application of sedaxane to cotton and sugar beet ranged from 9 × 10

- 8 to 1 × 10

- 6 , as indicated in
Table 9.1.3

.

Secondary Handler Cancer Risk
The cancer risk estimate for secondary handlers (i.e., planters) ranged from 4 × 10

- 10 to 8 × 10

- 9

, as indicated in Table 9.1.4

.

Cancer Risk Characterization
To estimate the LADD (Life time Average Daily Dose) the maximum application rate, the number of days worked per year, and the number of years one would be exposed during a working lifetime are needed. Each one of these variables depend s upon many factors. For example, the number o f days worked per year must correspond to the days worked when the pesticide of concern has been applied. Additionally, the residue dissipation over the work interval should be estimated. Without an estimate for residue dissipation one needs to assume (u nrealistically) that the worker is exposed to the highest residue value in the seed treatment facility. For sedaxane , a screening estimate was developed because lifetime use data are not available. The screening level estimate assumed: (1) that commercia l seed treaters would be exposed to sedaxane for 175 days per year for cotton and 90 days for sug ar beet ; (2) no residue dissipation; (3) maximum application rate ; and (4) a seed treater would be exposed for 35 years. These assumptions are consistent with recommendations from the Exposure Science Advisory Committee (ExpoSAC) and information from the National A gricultural Statistics Service. Due

to these high

- end assumptions, HED believe s that the cancer risk estimates are conservative.Sedaxane (129223) Human Health Risk Assessment D419897, D421932

Page 29 of 76 T able 9 .1.1 Non

- Cancer Risk for Seed

- Treatment Handlers

Exposure
Scenario (Scenario #) PPE Dermal
Unit Exposure (mg/lb ai) Inhalation

Unit Exposure (mg/lb ai) Seed Type Application

Rate (lb ai per 100 lb seed) Amount

Treated a (lb seed

tr eated per day) Daily

Inhalation

Dose (mg/kg/day) b Short

- Term
Inhalation
MOE c

Commercial: Loader/Applicator Loading/Applying Liquids for
Seed Treatment SL, G 0.023 0.00034 Cotton 0.0 2 117

, 000 (ST) 0.000099 300,000

Sugar beet 0.66 3,000 (ST) 0.000084 360,000

Sewing Seeds after
Seed treatment SL,

no G 0.0062 0.00023 Cotton 0.02 117

, 000 (ST) 0.000067 450,000

Sugar beet 0.66 3,000 (ST) 0.000057 530,000

Commercial: Bagger Bagging Seeds
after Seed

treatment SL,

no G 0.0091 0.00016 Cotton 0.0 2 117,000 (ST) 0.000047 640,000

Sugar beet 0.66 3,000 (ST) 0.000041 760,000

Multiple Activities Worker Multiple Activities
for Seed treatment SL,G 0.042 0.0016 Cotton 0.0 2 117

, 000 (ST) 0.00047 64,000

Sugar beet 0.66 3,000 (ST) 0.0004 76,000

a Daily Amount T reated values are based on the information on Expo SAC policy 15.1
b Daily inhalation dose (mg/kg/d ay ) = (unit exposure (mg/lb ai) * application. rate (lb ai/lb seed) * daily amount treated / body weight (80 kg).

c Short

- and intermediate

- term inhalation MOE = NOAEL (30 mg/kg/day) / daily inhalation dermal dose.Sedaxane (129223) Human Health Risk Assessme nt D419897, D421932

Page 30 of 76 Table 9

. 1.2 Non

- Cancer Risk for Handler

- Seed Planters
Exposure
Scenario (Scenario #) Mitigation

Level Inhalation Unit

Exposure (mg/lb ai) Seed Type Application Rate (lb ai per 100 lb seed) Amount

Planted a Daily

Inhalation

Dose b (mg/kg/day) Short

- - Term

Inhalation MOE c

Seed Planters

Planting Treated
Seed Baseline

(no respirator) 0.0034 Cotton 0.0 2 3800 0.000032 930,000

Sugar beet 0.66 209 0.000059 510,000

a Daily Amount Planted values are based on the information i n Expo SAC policy 15. 1

b Daily inhalation dose (mg/kg/d ay ) = (unit exposure (mg/lb ai) * application. rate (lb ai/lb seed) * daily amount treated / body weight (80 kg).

c Short

- term and intermediate

- term inhalation MOE = NOAEL (30 mg/kg/d ay ) / daily inhalation dose.

Table 9.1.3 Primary Handler Cancer Risk for Sedaxane
Crop Dermal Dose a

(mg/kg/day) Inhalation Dose a (mg/kg/day) Combined ADD b (mg/kg/day) Commercial LADD c (mg/kg/day) Commercial Cancer Risk d

Commercial : Mixer/Loader/Treater (G, No respirator)

Cotton 5.38E

- 04 9.95e

- 05 6.38e

- 04 1.37e

- 04 6.31e

- 07

Sugar beet 4.55e

- 04 8.42e

- 05 5.40e

- 04 5.97e

- 05 2.75e

- 07

Commercial :Sewer (Baseline)

Cotton 1.45e

- 04 6.73e

- 05 2.12e

- 04 4.57e

- 05 2.10e

- 07 Sugar beet 1.23e

- 04 5.69e

- 05 1.80e

- 04 1.99e

- 05 9.15e

- 08 Commercial :Bagger (Baseline)

Cotton 2.13e

- 04 4.68e

- 05 2.60e

- 04 5.59e

- 05 2.57e

- 07 Sugar beet 1.80e

- 04 3.96e

- 05 2.20e

- 04 2.43e

- 05 1.12e

- 07 Multiple Activities (G, no respirator)

Cotton 9.83e

- 04 4.68e

- 04 1.45e

- 03 3.12e

- 04 1.44e

- 06 Sugar beet 8.32e

- 04 3.96e

- 04 1.36e

- 04 2.76e

- 04 6.25e

- 07
a. Unit exposure (mg ai/lb of seed) x Application Rate ( see T able 3.3 ) x the amount of seed planted/day (lbs) / body weight (80kg) b. ADD (mg/kg/day) = [Dermal Dose (mg/kg/day) x 8%DA]+ Inhalation Dose (mg/kg/day) c. LADD (mg/kg/day) = ADD x [( 175 days ( cotton ) 90 days ( sugar beet ) /yr Commercial)/ (365 days/yr)] x (35 yrs/7 8 yrs)
d Cancer Ris k = LADD x Q* ( 4.64 x 10

- 3 mg/kg/day)

- 1Sedaxane (129223) Human Health Risk Assessme nt D419897, D421932

Page 31 of 76 Table 9.1.4: Planter Cancer Risk for Seda xane Crop Dermal Dose a (mg/kg/day)

(glove) Inhalation Dose a (mg/kg/day) No respirator Planters ADD b (mg/kg/day) Planters / LADD c (mg/kg/day) Planters
Cancer Risk d

Cotton 3.80e

- 05 6.46e

- 06 4.45e

- 05 1.64e

- 06 7.54e

- 09 Sugar beet 1.31e

- 06 2.23e

- 07 1.54e

- 06 8.50e

- 08 3.91e

- 10

a. U nit exposure (mg ai/lb of seed) x Application Rate ( see T able 3.3 ) x the amount of seed planted/day (lbs) / body weight (80kg)
b. ADD (mg/kg/day) = [Dermal Dose (mg/kg/day) x 8%DA]+ Inhalation Dose (mg/kg/day) c. Planter LADD (mg/kg/day) = ADD x [( 30 days/yr)/ (365 days/yr)] x (35 yrs/7 8 yrs)
d Plan ter Cancer Risk = LADD x Q* ( 4.64 x 10

- 3 mg/kg/day)

- 1Sedaxane (129223) Human Health Risk Assessment D419897, D421932

Page 32 of 76 9.2 Short

- /Intermediate

- Term Post

- Application Risk

9.2.1 Dermal Postapplication Risk

The potential for post

- application exposures following the planting of sedaxane

- treated cotton and sugar beet is unlikely

. S ustained levels of contact with treated seed after it has been placed in the soil or other planting media would not be expected because no routine cultural practice required for the production of agricultural commodities involves such an activity as defined in
the no/low contact criteria in the Worke r Protection Standard (WPS)

. Also, as no dermal hazard has been identified, no quantitative post

- application assessment is required for exposure to treated seeds that have already been planted

.

The proposed labels require that workers wear long

- sleeved s hirt, long pants, shoes, socks and
chemical

- resistant gloves when opening bags of treated seed or loading/pouring the treated seed. No additional PPE requirements are necessary for labeling of treated seed. Certain tasks, even though they are not routine, may involve contact with the soil subsurface ( e.g. , repair of certain irrigation equipment) and they are covered by the REI. Therefore, the REI is based on the acute toxicity of the active ingredients. Note that REI recommendations include consideration of only
sedaxane

. A 12

- hour REI is appropriate for sedaxane

- treated seeds , although the Worker Protection Standard (WPS) allows workers to enter treated areas without restriction if there will
be no work er contact with the treated seeds in the soil or planting media. If longer REIs are appropriate for any co

- formulant(s) in the end

- use product, those values should supersede the
REI recommendation for sedaxane.

9.2.2 Inhalation Postapplication Risk

A p ostapplication inhalation exposure assessment is not required as exposure is expected to be negligible. Seed treatment assessments provide quantitative inhalation exposure assessments for seed treaters and secondary handlers ( i.e.

, planters). T hese expo sure estimates are protective of

any postapplication inhalation exposure scenarios.

10.0 References

Toxicology Reference

Author: Jessica Kidwell

Date: May 18 , 2011

TXR No.: 005 5854
Title: Sedaxane : Report of the Cancer Assessment Review Committee

.

Author: Jessica Kidwell

Date: January 24 , 2012
Title: Sedaxane

- ToxSAC Meeting on December 1, 2011

.Sedaxane (129223) Human Health Risk Assessment D419897, D421932

Page 33 of 76 Author: Anwar Dunbar

Date: May 15, 2013

TXR No.: 0056647
Title: Sedaxane: Summary of Hazard and Science Policy Council (HASPOC) Meeting

of April 25, 2013: Recommendations on the need for a sub

- chronic inhalation toxicity study.

Product Chemistry Reference

Author: Akiva Abramovitch

Date: November 2, 2011
DP Number: D38235 0
Title: Product Chemistry Review of Sedaxane Technical.

Residue Chemistry References

Author: Ideliz Encarnacion

Date: November 10 , 2011
DP Number: D387015
Title: Sedaxane Seed Treatment

. Report of the Residues of Concern Knowledgebase

Subc ommittee (ROCKS)

.

Author: Elizabeth Holman

Date: December 19, 2012
DP Number: D406945
Title: Sedaxane Seed Treatment Drinking Water Revisit

. Report of the Residues of

Concern Knowledgebase Subc ommittee (ROCKS)

.

Author: William Donovan

Date: December 19, 2014
DP Number s : D4 23822, D422929
Title: Sedaxane

. Petition for the Establishment of Permanent Tolerances for Seed

Treatment Use on Cotton and Sugar Beet. S ummary of Analytical Chemistry and
Residue Data.

Author: William Donovan

Date: January 20, 2015
DP Number: D425112
Title: Sedaxane

. Petition for the Establishment of Permanent Tolerances for Seed

Treatment Use on Cotton and Sugar Beet. Updates to S ummary of Analytical Chemistry and Residue Data.Sedaxane (129223) Human Health Risk Assessment D419897, D421932

Page 34 of 76 Drinking Water Assessment

Author: Rochelle Bohaty

Date: October 23, 2014
DP Number: D419976
Title: Drinking Water Assessment for the Proposed New Use of Sedaxane as a Seed

Treatment on Sugar Beet and Cotton

.

Author: Rochelle Bohaty & James Hetrick

Date: March 18 , 2013
DP Number: D 405391 & D407956
Title: Drinking Water Assessment for the Proposed New Use of Sedaxane as a Seed

Treatment on Corn, Sorghum, Dried Shelled Pea and Bean (Subgroup 6C; except soybean), Rapeseed (Subgroup 20A) and Potato

.

Dietary Exposure Assessment

Author: William Donovan

Date: November 12 , 201 4
DP Number: D423821
Title: Sedaxane. Acute, Chronic, and Cancer Aggregate Dietary (Food and Drinking

Water) Exposure and Risk Assessments to Support Seed Treatment Uses on Cotton and Sugar Beet.

Occupational Assessment References

Author: Seyed Tadayon

Date: January 20 , 201 5
DP Number: D 423820
Title: Sedaxane : Occupational and Residential Exposure/Risk Assessment for Seed

Treatment Uses on Sugar beet and Cotton.

Science Advisory Council for Exposure (ExpoSAC) Policy 14: Standard Operating Procedures (SOPs) for Seed Treatment (May 1, 2003).

ExpoSAC Policy 15: Amount of Seed Treated or Planted per Day (March 2, 2004).Sedaxane (129223) Human Health Risk Assessment D419897, D421932

Page 35 of 76 A ppendix A

. Toxicology Profile and Executive Summaries

A.1 Toxicology Data Requirements
Th e toxicological data requirements (40 CFR 158.340) for food uses for sedaxane are in Table A1. Use of the new guideline numbers does not imply that the new (1998) guideline protocols
were used.

Table A.1 Sedaxane Toxicology Data Requirements

Study Technical

Required Satisfied

870.1100 Acute Oral Toxicity

................................ ........................... 870.1200 Acute Dermal Toxicity

................................ ....................... 870.1300 Acute Inhalation Toxicity

................................ ................... 870.2400 Primary Eye Irritation

................................ ........................ 870.2500 Primary Dermal Irritation

................................ ................... 870.2600 Dermal Sensitization yes

yes

yes

yes

yes

yes yes

yes

yes

yes

yes

yes

870.3100 Oral Sub

- chronic (rodent)

................................ .................. 870.3150 Oral Sub

- chronic (non

- rodent)

................................ ........... 870.3200 21/28

- Day Dermal

................................ .............................. 870.3250 90

- Day Dermal

................................ ................................ ... 870.3465 90

- Day Inhalation

................................ .............................. yes

yes

yes

no

no yes

yes

yes

---

---

870.3700a Developmental Toxicity (rodent)

................................ ....... 870.3700b Developmental Toxicity (non

- rodent)

................................ 870.3800 Reproduction

................................ ................................ ...... yes

yes

yes yes

yes

yes

870.4100a Chronic Toxicity (rodent)

................................ .................... 870.4100b Chronic Toxicity (non

- rodent)

................................ ............ 870.4200a Oncogenicity (rat)

................................ ............................... 870.4200b Oncogenicity (mouse)

................................ ......................... 870.4300 Chronic/Oncogenicity

................................ ......................... yes

yes

yes

yes

yes yes

yes

yes

yes

yes

870.5100 Mutagenicity

-- Gene Mutation

- bacterial
870.5300 Mutagenicity

-- In vitro, Mammalian cells

870.5375 Mutagenicity

-- Structural Chromosomal Aberration
870.5395 Mutagenicity

-- In Vivo Mammalian Cytogenetics yes

yes

yes

yes yes

yes

yes

yes

870.6100a Acute Delayed Neurotox. (hen)

................................ ........... 870.6100b 90

- Day Neurotoxicity (hen)

................................ ................ 870.6200a Acute Neurotox. Screening Battery (rat)

............................. 870.6200b 90

- Day Neurotox. Screening Battery (rat)

.......................... 870.6300 Developmental Neurotoxicity

................................ ............. no

no

yes

yes

no ---

--- yes

yes

---

870.7485 General Metabolism

................................ ............................. 870.7600 Dermal Penetration

................................ .............................. 870.7800 Immunotoxicity

................................ ................................ .... yes CR

yes yes

yes

yes CR: Conditionally Required

.

--- : Not Provided.Sedaxane (129223) Human Health Risk Assessment D419897, D421932

Page 36 of 76 A.2 Toxicity Profile s

A.2.1 Sedaxane Acute Toxicity

Study Type MRID(s) Results US EPA Toxicity Category

870.1100

Acute Oral, Rat MRID

47473366 LD 50 = 5000

mg/kg/bw (95% CI
2513

- 9210)
Females III

870.1200

Acute Dermal,

Rat MRID

47473367 LD 50 > 5000

mg/kg/bw IV

870.1300

Acute Inhalation, Rat MRID

47473368 LC 50 >5.24

mg/L IV

870.2400

Acute Eye irritation, rabbit MRID

47473370 Minimally

irritating IV

870.2500

Acute Dermal Irritation, Rabbit MRID

47473369 Non

- irritating IV

870.2600

Skin sensitization,

mouse LLNA MRID

47473371 Negative Not a skin
sensitizer

A.2.2 Metabolite CSCD465008 Acute Toxicity

Study Type MRID(s) Results US EPA Toxicity Category

870.1100

Acute Oral, Rat

CSCD465008
Metabolite MRID

47473366 LD 50 > 2000

mg/kg/bw
Females I I ISedaxane (129223) Human Health Risk Assessment D419897, D421932

Page 37 of 76 A.2.2 Sub

- chronic, Chronic, Other Toxicity
Acute, Sub

- chronic, Chronic, and Other Toxicity Profile

– Sedaxane Technical

Study Type MRID No. / Classification/

Doses Results

Rat Sub

- chronic Oral Toxicity 28

- day CSCD465008 Metabolite, Rat (Oral

- dietary)

MRID 47746827 Acceptable/Non

- Guideline

0, 2000, 6000, 12000 ppm ♂: 0, 175, 497, 1018 mg/kg bw/day ♀: 0, 176, 525, 1107 mg/kg bw/day No treatment

- related effects on survival, clinical signs, body weights, food consumption, FOB, motor activity, ophthalmoscopy, hematology, clinical chemistry, organ weights, urinalysis o r histopathology. No treatment

- related effects on cytochrome P450 content, 7

- ethoxyresorufin O

- dealkylation (CYP1A1/2) or 7

- pentoxyresorufin O

dealkylation (CYP2B1/2) were observed.

NOAEL= 497/1107 mg/kg/day
LOAEL= 1018/ ND mg/kg/day,
based on decreased k idney weights

28

- day Comparative Isomer Toxicity, Rat (trans isomer, cis
isomer and a racemic 1:1 cis

trans mixture of sedaxane) (Oral

- dietary)

MRID 47473372. Acceptable/Non

- Guideline

0, 500, 2000, 5000 ppm SYN508210: ♂ 0, 47.0, 187.4, 438.2 mg/kg bw/day, ♀ 0, 48.4, 177.1, 384.3 mg/kg bw/day SYN508211: ♂ 0, 45.9, 182.7, 438.2 mg/kg bw/day, ♀ 0, 47.6, 179.6, 435.8 mg/kg bw/day SYN524464: ♂ 0, 47.5, 181.2, 444.6 mg/kg bw/day, ♀ 0, 46.7, 181.1, 428.1 mg/kg bw/day SYN508210 (trans), SYN508211 (cis)
and SYN524464 (1:1 cis

- trans mixture) had similar effects on body weight, liver weight and cholesterol levels, however, the trans form had a slightly more effect.
The cis form at 435.8

- 438.2 mg/kg/day decreased heart weight significantly in both genders (a ti ssue with high mitochondrial content). All isomers caused increased 16β hydroxylation of testosterone, consistent with being potent
inducers of CYP 2B isoforms. The 3 test compounds caused decreases in 16α and 2α hydroxylation in males but increases

in fem ales. Both 16α and 2α are markers for the cytochrome isoenzyme CYP 2C11. The above findings were supported by increased CYP 2B and CYP 3A contents. The weakly increased EROD activity suggests that SYN508210,
SYN508211 and SYN524464 do not act as polycyclic aromatic hydrocarbon

- type
inducers.

Toxicokinetics: Tmax =12

- 20 h; no
obvious differences between the trans and cis isomers; Cmax and AUC were ~10

- fold lower in the cis isomer group vs. trans isomer group.Sedaxane (129223) Human Health Risk Assessment D419897, D421932

Page 38 of 76 Acute, Sub

- chronic, Chronic, and Other Toxicity Profile

– Sedaxane Technical

Study Type MRID No. / Classification/

Doses Results

870.3100
90

- day Rat, Sedaxane (Oral

- Diet)

MRID #47473375. Acceptable/Guideline

0, 250, 1000, 4000 ppm ♂: 0, 18.6, 72.9, 299.6 mg/kg bw/day ♀: 0, 21.4, 85.7, 315.3 mg/kg bw/day NOAEL = 72.9/85.7 mg/kg/day ♂/♀ LOAEL = 299.6/315.3 mg/kg/day, based on decreased body weights, food consumption and foo d efficiency, increased total protein, increased liver weight, centrilobular hypertrophy and pigmentation in the liver in both sexes, plasma albumin in males and increased platelet counts, increased plasma cholesterol and decreased heart weights in
females

.

870.3100
13

- Week Rat, Sedaxane (Oral

- Diet)

MRID 47473376 Acceptable/Guideline

0, 300, 2000, 4000 ppm ♂: 0, 24.8, 168.0, 325.1 mg/kg bw/day ♀: 0, 28.3, 186.0, 349.8 mg/kg bw/day NOAEL=24.8/28.3 mg/kg/day ♂/♀ LOAEL= 168.0/186.0 mg/kg/day ♂/♀, based on decreased body weight and body weight gain in females and decreased forelimb grip strength in both sexes. Dose spacing not a good as other 90

- day study.

Mouse Sub

- chronic Oral Toxicity 28

- day Mouse, Sedaxane (Oral

- Diet)

MRID 47473373. Acceptable/Non

- Guideline

0, 1000, 5000, 7000 ppm ♂: 0, 178, 920, 1268 mg/kg/day ♀: 0, 248, 1150, 1800 mg/kg/day NOAEL=920 mg/kg/day LOAEL=1268 mg/kg/day, based on
decreased serum calcium levels and increased triglycerides in males.

870.3100
90

- day Mouse, Sedaxane (Oral

- Diet)

MRID 47473377. Acceptable/Guideline

0, 500, 3500, 7000 ppm ♂: 0, 80, 567, 1167 mg/kg/day ♀: 0, 112, 810, 1455 mg/kg/day NOAEL=567/1455 mg/kg/day ♂/♀ LOAEL=1167/NA mg/kg/day based on decreased body weight, body weight gains, food efficiency, total bilirubin, and increased adjusted liver and testes weights. Also based on decreased white blood cells and lymphocytes.Sedaxane (129223) Human Health Risk Assessment D419897, D421932

Page 39 of 76 Acute, Sub

- chronic, Chronic, and Other Toxicity Profile

– Sedaxane Technical

Study Type MRID No. / Classification/

Doses Results

Dog Sub

- chronic Oral Toxicity 28

- day Dog, Sedaxane (Oral

- Capsule)

MRID 47473374 Acceptable/Non

- Guideline

0, 50, 100, 300 mg/kg/day NOAEL= 50 mg/kg/day LOAEL= 100 mg/kg/day, based on liver vacuolation at 100 mg/kg/day (♀) and at 300 mg/kg/day (♂).

870.3150
90

- day Dog, Sedaxane (Oral

- Capsule)

MRID 47473378. Acceptable/Guideline

0, 50, 150, 400 mg/kg/day NOAEL = 150/Not determined mg/kg bw/day ♂/♀ LOAEL = 400/50 mg/kg bw/day ♂/♀, based on decreased body weight, body weight gain, food consumption, lymphocyte counts, , spleen weights (♂); decreased body weight and body weight gain (preceded by body weight lo ss) (♀) At 150 mg/kg bw/day, decreased leukocytes, lymphocytes and monocytes (♀). At 400 mg/kg bw/day, also decreased spleen weights (♀)

Rat 28

- Day Dermal Toxicity 870.3200 Rat, Sedaxane

MRID 47473380 Acceptable/Guideline

0, 100, 300, 1000 mg/kg bw/day NOAEL= 1000 mg/kg/day LOAEL= Not determined, no systemic
effects

Rat Prenatal Developmental Toxicity Preliminary Rat Study

- Sedaxane (Oral

- Gavage)

MRID 47473391 Acceptable/Non

- Guideline

0, 200, 500, 750 mg/kg bw/day Maternal NOAEL= Not determined Maternal LOAEL=200 mg/kg/day, based

on decreased body weight gains and food consumption. At 500 mg/kg bw/day (exceeded
maximum tolerated dose ( MTD ) ), decreased body weight and food consumption, body weight loss; decreased activity, ruffled fur, poor clinical condition, lateral recumbency, uncoordinated movements)

- animals were sacrificed for humane reasons prior to study termination. At 750 mg/kg bw/day, one death (GD 11).

Fetal NOAEL/LOAEL = Not determinedSedaxane (129223) Human Health Risk Assessment D419897, D421932

Page 40 of 76 Acute, Sub

- chronic, Chronic, and Other Toxicity Profile

– Sedaxane Technical

Study Type MRID No. / Classification/

Doses Results

870.3700a
Definitive Rat Developmental Study

- Sedaxane (Oral

- Gavage)

MRID 47473392. Acceptable/Guideline

0, 25, 100, 200 mg/kg bw/day Maternal NOAEL= 100 mg/kg bw/day Maternal LOAEL= 200 mg/kg bw/day, based on decreased body weight, body weight gain, food consumption.

Fetal NOAEL = 1 00 mg/kg bw/day
Fetal LOAEL = 200 mg/kd/day based on decreased fetal weights

Rabbit Prenatal Developmental Toxicity Preliminary Rabbit Developmental Study

- Sedaxane (Oral

- G avage)

MRID 47473393. Acceptable/Non

- Guideline

0, 100, 300, 500 mg/kg/day Maternal NOAEL=100 mg/kg/day Maternal LOAEL=300 mg/kg/day

, based on increased liver weight (histopathology was not conducted), decreased defecation, decreased body weight gain/body weight loss, food consumption. At 500 mg/kg bw/day, increased liver weight (histopathology was not conducted), decreased defecation, decreased body weight gain/body weight loss, food consumption; increased mortality (2♀ on GD 16; 1♀ delivered early on GD 29), preceded by BW loss, decreased food consumption, decreased
defecation and/or soft stool.

Fetal NOAEL = 500 mg/kg/day Fetal LOAEL= ND, No adverse effects at any dose level based on a limited number of parameters assessed.

870.3700b
Definitive Rabbit Developmental Study

- Sedaxane (Oral

- Gavage)
MRID 47473394. Acceptable/Guideline

0, 25, 100, 200 mg/kg bw/day Maternal NOAEL= 100 mg/kg/day Maternal LOAEL= 200 mg/kg/day, based on abortions, decreased body weight gain/body weight loss, reduced food consumption, defecation.

Fetal NOAEL = 100 mg/kg/day
Fetal LOAEL = 200 mg/kg/day, based on
increased unossified sternebrae and 13th rudimentary ribs and a decrease in fetal weights (

- 9%) and increased abortions.Sedaxane (129223) Human Health Risk Assessment D419897, D421932

Page 41 of 76 Acute, Sub

- chronic, Chronic, and Other Toxicity Profile

– Sedaxane Technical

Study Type MRID No. / Classification/

Doses Results

Rat Reproduction and Fertility Effects Preliminary Rat Reproduction Study

- Sedaxane (Oral

- Diet)

MRID 47473389. Acceptable/Non

- Guideline

0, 500, 1500, 3600 ppm (~0, 50, 150, 360 mg/kg bw/day; assuming that 0.100 ppm = 1 mg/kg bw/day) Parental NOAE L = 50 mg/kg/day Parental LOAEL= 150 mg/kg/day,
based on decreased body weight, body weight gains, food consum ption (♀); increased liver weights, abnormally darkened livers (♀). At 360 mg/kg bw/day (exceeded MTD), decreased body weight, body weight gains, food consumption; increased liver weights, abnormally darkened livers (♀).

Repro NOAEL= 150 mg/kg/day Repro LOAEL= 360 mg/kg/day (exceeded MTD), based on decreased mean implantation sites, number of pups born; increased number of pup deaths (LD 0

- 4); decreased mean litter size, viability index, lactation index; increased missing pups (presumed cannibalized).

Offspring NOAEL = 50 mg/kg/day Offspring LOAEL= 150 mg/kg/day,
based on decreased body weights, increased liver weights. At 360 mg/kg bw/day (exceeded MTD), decreased body weight and body weight gains, increased liver weights.Sedaxane (129223) Human Health Risk Assessment D419897, D421932

Page 42 of 76 Acute, Sub

- chronic, Chronic, and Other Toxicity Profile

– Sedaxane Technical

Study Type MRID No. / Classification/

Doses Results

870.3800
Definitive Rat Re production Study

- Sedaxane (Oral

- Diet)

MRID 47473390. Acceptable/Guideline

MRID 49383101, 49383102 Updated study report with
intermediate dose follicle count
data

0, 200, 500, 1500 ppm

P generation: ♂ 0, 16, 41, 120 mg/kg bw/day; ♀ 0, 18, 46, 143 mg/kg bw/day

F 1 generation: ♂ 0, 17, 43, 134 mg/kg bw/day; ♀ 0, 19, 47, 141 mg/kg bw/day Parental NOAEL= 500 ppm (41/46 mg/kg bw/day ♂/♀) LOAEL = 1500 ppm (120/143 mg/kg bw/day ♂/♀) body weight gain (P ♀ premating), food consumption (P ♂ premating; ♀ t hroughout), decreased ovarian weights (F 1 ♀).

Repro NOAEL = 46 mg/kg/day Repro LOAEL= Not determined/143 mg/kg bw/day ♂/♀, based on decreased primordial (P gen), growing and antral follicles (F 1 gen) and corpora lutea (P and

F 1 gen); increase in lactational diestrous

, increased implantation loss

.

Offspring NOAEL = 43/

4 7 mg/kg/day

, (500 ppm) Offspring LOAEL= 1 34/141 mg/kg/day (1500 ppm ), based on decreased pup body weights, increased liver weight (histopathology not conducted)

, decreased spleen weight (histopathology not conducted).

Chronic Dog Toxicity

(1 Year) 870.4100a
Sedaxane (Oral

- Capsule)

MRID 47473379. Acceptable/Guideline

0, 15, 50, 200 mg/kg bw/day NOAEL = 50 mg/kg/day LOAEL = 200 mg/kg bw/day based on decreased body weights, body weight gains and food consumption, decreased spleen weights in both sexes, plus decreased glucose levels and decreased testes weight in males. Hypoglycemia can
be an indication of mitochondrial
inhibition in the liver.

Mice

Ca rcinogenicity (CD

- 1) 870.4200b
Sedaxane (Oral

- Diet)

MRID 47473388. Acceptable/Guideline

0, 200, 1250, 7000 ppm ♂: 0, 25, 157, 900 mg/kg/day ♀: 0, 29, 185, 1001 mg/kg/day NOAEL= NOAEL = 157/185 mg/kg/day ♂/♀ LOAEL = 900/1001 mg/kg/day ♂/♀, based on decreased body weight, body weight gains, food efficiency; increased incidences of hepatocellular adenomas, carcinomas and combined hepatocellular
adenomas and/or carcinoma s (♂)

.Sedaxane (129223) Human Health Risk Assessment D419897, D421932

Page 43 of 76 Acute, Sub

- chronic, Chronic, and Other Toxicity Profile

– Sedaxane Technical

Study Type MRID No. / Classification/

Doses Results

Rat Chronic Toxicity/ Carcinogenicity 870.4300
Sedaxane (Oral

- Di et)

MRID 47473386. Acceptable/Guideline

0, 200, 1200, 3600 ppm ♂ 0, 11, 67, 218 mg/kg bw/day ♀: 0, 14, 86, 261 mg/kg bw/day NOAEL= 11/14 mg/kg bw/day ♂/♀ LOAEL = 67/86 mg/kg bw/day ♂/♀, based on increased liver weight, increased incidences of hepatocyte hypertrophy and eosinophilic foci, and thyroid follicular cell hypertrophy, basophilic colloid and epithelial desquamation, plus increased phosphate levels (oxidative phosphorylation inhi bition)(♂). In females, it was based on decreased body weight and body weight gain, increased liver weight and the same thyroid histopathology noted above for males. At 218/261 mg/kg bw/day, decreased food efficiency Wk 1

- 13; decreased body weight, bodywe ight gain, increased GGT (marginal), glucose, phosphate, increased thyroid follicular cell adenomas & liver hepatocellular adenomas (♂); decreased food consumption, increased hepatocyte hypertrophy and pigment, thyroid follicular cell hyperplasia, thymus epithelial tubular hyperplasia, kidney inflammation/inflammatory cell infiltration; decreased vaginal mucification, increased uterine adenocarcinomas (♀).

Bacterial Reverse
Mutation Test 870.5100
Sedaxane

MRID47473381 Acceptable/Guideline

Doses up to 5000μg/plate (with and without activation) Negative. There was no evidence of
induced reverse mutations with or without
activation.

870.5100 CSCD465008 (metabolite)

MRID 47746852. Acceptable/Guideline

Doses up to 5000 μg/plate (with

and withou t activation) Negative. There was no evidence of
induced reverse mutations with or without
activation.Sedaxane (129223) Human Health Risk Assessment D419897, D421932

Page 44 of 76 Acute, Sub

- chronic, Chronic, and Other Toxicity Profile

– Sedaxane Technical

Study Type MRID No. / Classification/

Doses Results

In vitro mammalian cell gene mutation

test 870.5300
Sedaxane

MRID 47473383. Acceptable/Guideline

4 hr (without activation): 6.9

- 82.5 (Exp. 1), 20

- 90 μg/mL (Exp. 2) 4 hr (with activation): 13.8

- 110.0 (Exp.1), 20.0

- 100.0 μg/mL (Exp. 2) Negative

. There was no evidence of gene
mutations with or without activation.

870.5300 CSCD465008 (metabolite)

MRID 47746856. Acceptable/Guideline

4 hr (with or without activation):
110

- 1760μg/mL Negative. There was no evidence of gene
mutations with or without activation.

In vitro mammalian
chromosome
aberration test 870.5375
Sedaxane

MRID 47473382. Acceptable/Guideline

6 hr (without activation): 52.4

- 200 μg/mL; 6hr (with activation): 65.5

- 250μg/mL; 24

hrs (without activation): 41.9

- 160 μg/mL Negative.

870.5375 CSCD465008 (metabolite)

MRID 47746860. Acceptable/Guideline

4 or 22 hr (without activation):
574.7

- 1760μg/mL; 4 hr (with activation): 328.4

- 1005.7μg/mL (Exp. 1), 574.7

- 1760.0 μg/mL (Exp. 2) Negative. There was no evidence of
chromosomal aberrations with or without
activation.

Mammalian erythrocyte 870.5395
Sedaxane

MRID 47473384. Acceptable/Guideline Negative. There was no significant increase in the frequency of micro

nucleated polychromatic erythrocytes.Sedaxane (129223) Human Health Risk Assessment D419897, D421932

Page 45 of 76 Acute, Sub

- chronic, Chronic, and Other Toxicity Profile

– Sedaxane Technical

Study Type MRID No. / Classification/

Doses Results

micronucleus test

Mouse ♂: 0, 500, 1000, 2000mg/kg bw

Unscheduled DNA Synthesis 870.5550
Sedaxane

MRID 47473385. Acceptable/Guideline

0, 500, 1000, 2000 mg/kg bw Negative

. The test material did not induce UDS in primary rat hepatocytes up to 2000 mg/kg.

Acute Neurotoxicity Screening Battery

– Rat (Sprague Dawley) Preliminary Rat ACN Study
Sedaxane

(Oral

- Gavage)
MRID 47473395. Acceptable/Non

- Guideline

0, 80, 1000, 2000 mg/kg bw NOAEL= Not determined

L OAEL = 80 mg/kg,
based on increased piloerection (2

- 8 h
post

- dose); hunched posture, spasms, reduced activity also noted sporadically At 1000 and 2000 mg/kg bw, increased piloerection (2

- 8 h ♂, beyond day 4 ♀

post

- dose); hunched posture, spasms, reduced activity, reduced activity, hunched posture, spasms, piloerection, uncoordinated movements (peak effect at 3 h post

- dose), decreased body weight and body weight gains.

870.6200a Rat ACN Study
Sedaxane

(Oral

- Gavage)
MRID 47473396. Acceptable/Guideline

0, 30, 250, 2000 mg/kg bw NOAEL = 30 mg/kg bw LOAEL = 250 mg/kg bw, based on reduced activity, decreased rearing, initial inactivity, piloerection, ruffled fur and recumbency, decreased body weight, body weight gains and food consumption (♂); plus weakened condition, swaying gait, decreased activity, reduced muscle tone and decreased locomotor activity & rearing (♀).The weakened condition, swaying gait and decreased activity were observed on days 2

- 7, whi le the other effects were on day 1. Hypothermia occurred at 2000 mg/kg.Sedaxane (129223) Human Health Risk Assessment D419897, D421932

Page 46 of 76 Acute, Sub

- chronic, Chronic, and Other Toxicity Profile

– Sedaxane Technical

Study Type MRID No. / Classification/

Doses Results

Sub

- Chronic Neurotoxicity Screening Battery

– Rat 28

- Day Preliminary SCN Study

- Sedaxane

(Oral

- Diet)
MRID 47473397. Acceptable/Non

- Guideline

0, 500, 2000, 5000 ppm ♂ 0, 37.8, 153.5, 360.1 mg/kg bw/day ♀ 0, 40.1, 156.4, 338.8 mg/kg bw/day NOAEL = 37.8 mg/kg/day

LOAEL= 153.5/156.4 mg/kg/day,
based on decreased food efficiency, body weight (♀), body weight gain (♀), food consumption (♀). At 360.1/338.8 mg/kg bw/day ♂ /♀, decreased body weight, body weight gain, food consumption. No neurobehavioral were performed in this range

- finding study.

870.6200b
90

- Day SCN Rat Study
Sedaxane

(Oral

- Diet)
MRID 47473398. Acceptable/Guideline

0, 300, 1000, 4000 ppm ♂ 0, 19.7, 66.0, 260.0 mg/kg bw/day ♀ 0, 24.3, 79.7, 302.9 mg/kg bw/day NOAEL = 66.0/79.7 mg/kg bw/day ♂/♀ LOAEL = 260.0/302.9 mg/kg bw/day ♂/♀, based on decreased body weight, body weight gains, food consumption, food efficiency, as well as reduced
locom otor activity.

870.7485
Rat Metabolism and
Pharmacokinetics 870.7485
Rat Excretion and Tissue
Distribution

- Sedaxane (Oral

- Gavage)

MRID 47473359. Acceptable/Guideline
Metabolism

- Single Dose Oral Recoveries of radioactivity ranged
between 96.3

- 104.9% AD, with no significant differences in tissue
distribution or excretion between the dose levels. The primary route of excretion of [pyrazole

14 C]

- SYN524464 was via the feces in both sexes, with urinary excretion slightly higher in females. The absorbed
radioa ctivity was rapidly distributed throughout the tissues and rapidly cleared
without accumulation of radio

- labelled
SYN524464 in the tissues.Sedaxane (129223) Human Health Risk Assessment D419897, D421932

Page 47 of 76 Acute, Sub

- chronic, Chronic, and Other Toxicity Profile

– Sedaxane Technical

Study Type MRID No. / Classification/

Doses Results

870.7485
Rat Pharmacokinetics

- Sedaxane

(Oral

- Gavage)
MRID 47473355. Acceptable/Guideline
Metabolism

- Single Dose Oral A mean of 91.6% or 97.2% AD was eliminated in urine and feces over 72 h by male and female rats. The major route of elimination was via the feces; however, urinary elimination was also an important
route of excretion in both sexes and slightly mo re pronounced in females compared to males. Recoveries of radioactivity ranged
between 91.5

- 101.1% AD. Concentrations of [pyrazole

- 5

- 14 C]

- SYN524464 were slightly higher in plasma than in whole blood at most time points, suggesting that total radioactivity was relatively evenly distributed between
them. In general, T
max was achieved at 1

- 6 h post dose and declined with estimated
terminal half

- life values ranging from
22.65

- 28.76 h. Terminal half

- life values
of 20.71

- 39.86 h were obtained for blood.
There w ere no apparent differences in the
AUC and C
max values between genders, or
between the dose levels. As doses of [pyrazole

- 5

- 14 C]

- SYN524464 were increased from 1 to 80 mg/kg bw, systemic exposure to total radioactivity
exhibited a 118

- 140 fold increase but, due to the observed variability in the concentrations for individual rats, this was not considered significant.

870.7485
Excretion in Bile Duct Cannulated Rats (pyrazole label)

- Sedaxane (Oral

- Gavage)

MRID 47473357. Acceptable/Guideline The majority of the administered radioactivity was excreted within the first day post

- dose for both dose levels. Absorption was estimated to be 87

- 89%
AD in males and 88

- 92% AD and
females. Fecal excretion and gastrointestinal tract contents were less
tha n 7% AD. Biliary excretion represented the predominant excretion
route for both sexes at 79

- 82% AD. Urinary excretion of the absorbed dose was limited, accounting for approximately 6

- 7% AD in males and 7

- 10% AD in females.Sedaxane (129223) Human Health Risk Assessment D419897, D421932

Page 48 of 76 Acute, Sub

- chronic, Chronic, and Other Toxicity Profile

– Sedaxane Technical

Study Type MRID No. / Classification/

Doses Results

870.7485
Excretion in Bile Duct Cannulated Rats (phenyl label)

- Sedaxane

(Oral

- Gavage)
MRID 47473360. Acceptable/Guideline There were no significant differences in absorption and elimination patterns between dose levels or between genders. For both dose groups, the majority of the administered radioactivity was excreted within the first day post

- dose and biliary excretion represented about 79

- 85% AD, with urinary excretion , accounting for approximately 5

- 8% AD. Absorption
was estimated to be 87

- 94% AD (urine radioactivity, cage w ashes, bile and residual carcass) with fecal excretion and
GI tract contents were less than 7% AD.

870.7485 Rat Tissue Depletion

- Sedaxane (Oral

- Gavage)

MRID 47473358. Acceptable/Guideline The tissue distribution of a single oral dose of 1 or 80 mg [pyrazole

- 5

- 14 C]

- SYN524464/kg bw was extensive.
Plasma half

- lives ranged from 25.84

- 32.33 h for both dose group and half

- lives in the whole blood ranged from 29.49

- 40.10 h. Tissue concentrations of radioactivity were highest at 1

- 1.5 h for
low dose and 5 h for high dose with progressively decreased thereafter with
elimination half lives of 0.1

- 3.2 days.
Most mean tissue concentrations were near the limit of reliable measurement by 96 h post dose. The high levels of radioactivity in the gastrointestinal tract and its contents were consistent with the established biliary elimination and fecal
excretion of SYN524464 metabolites. There were no pronounced gender differences in tissue distribution, depletion profiles, or half

- lives of elimination in the plasm a or whole blood.Sedaxane (129223) Human Health Risk Assessment D419897, D421932

Page 49 of 76 Acute, Sub

- chronic, Chronic, and Other Toxicity Profile

– Sedaxane Technical

Study Type MRID No. / Classification/

Doses Results

870.7485 Rat Investigation of the Nature and Identity of Radio

- labeled
Metabolites

- Sedaxane

(Oral

- Gavage)
MRID 47473356. Acceptable/Guideline The major metabolites were the trans para phenol CSCD658906 and the desmethyl trans para phenol CSCD659087 which together with the equivalent cis para phenol isomers. SYN524464 was extensively metabolized by rats through demethylation, hydroxylation, oxidation and conjugation pathways resulting in a number of hydroxylated metabolites and metabolites formed by cleavage of the terminal cyclopropyl moiety. Glucuronic acid, sulphate and glutathione conjugates were
also formed. CSCD659090 and
CSCD668404 accounted for approximately half the administered dose.Sedaxane (129223) Human Health Risk Assessment D419897, D421932

Page 50 of 76 Acute, Sub

- chronic, Chronic, and Other Toxicity Profile

– Sedaxane Technical

Study Type MRID No. / Classification/

Doses Results

870.7485
Tissue Distribution and
Elimination in the Rat

- Repeated Dose

- Sedaxane

(Oral

- Gavage)
MRID 47473362. Acceptable/Guideline The majority of the oral administered radioactivity was excreted via the feces
at 60.9% AD over the 24 h collection period, with urinary excretion at 1 3.0% AD. Recovery of administered radioactivity was incomplete by 24 h
post

- dose with a mean of 75.7% AD.
Similar results were obtained after 14 daily dosings, with some of the dosing from day 13 also contributing to the day
14 elimination.
Tissue concent rations of radioactivity were highest at 24 h following the
fourteenth and final dose with the exception of whole blood and plasma, for which the highest mean concentrations
were observed 24 h after the tenth dose. The liver and kidney had the highest
lev els after 14 daily dosings, respectively.
Most mean tissue concentrations appeared either to have attained or to be approaching steady state kinetics by the
end of the 14 day dosing period. The high levels of radioactivity in the gastrointestinal tract and its contents were consistent with the established biliary
elimination and fecal excretion of
SYN524464 metabolites. There were no pronounced sex differences in tissue distribution, depletion profiles, or half

lives of elimination in the plasma or
whole b lood.

Immunotoxicity

Mouse (CD

- 1) 870.7800
Sedaxane (Oral

- Diet)

MRID 47473405. Acceptable/Guideline

0, 62.5, 250 and 1000 mg/kg/day NOAEL =1080.1 mg/kg bw/day LOAEL = Not determined, no decrease in TDAR response, Spleen and thymus weight changes not statistically significant ( high coefficients of variation noted for IgM data)Sedaxane (129223) Human Health Risk Assessment D419897, D421932

Page 51 of 76 

### A.3 Hazard Identification and Endpoint Selection

A.3.1 Acute Reference Dose (aRfD)

– All Populations

Study Selected: Acute Neurotoxicity Study

MRID No.: 47473396 Executive Summary : See Appendix A, Guideline [§ 870.6200a]

Dose and Endpoint for Establishing aRfD: The NOAEL of 30 mg/kg/day is based on clinical signs of reduced activity, decreased rearing, initial inactivity, piloerection, ruffled fur and recumbency , decreased body weight, body weight gains and food consumption in males at the LOAEL of 250 mg/kg. The weakened condition, swaying gait and decreased activity were observed on days 2

- 7, while the other effects were on day 1.

UF(s): A UF of 100 was applied to account for interspecies extrapolation (10X) and intraspecies variation (10X).

Comments on Study/Endpoint/UFs : This study provides the lowest NOAEL in the database considered to be valid for an acute effect and is protective for any potential adverse effects in humans, including the Females 13+ category. A preliminary ACN study with a LOAEL of 80 mg/kg/day (LDT) based on increased piloerection (2

- 8 hrs postdosing), hunched posture, spasms, and reduced activity provides confid ence in the NOAEL/LOAEL (30/250 mg/kg/day, which is a large dose spread) for the definitive ACN study. The 28

- day dog study was also considered with a higher NOAEL of 50 mg/kg/day, however, the only effect at 250 mg/kg/day was liver vacuolation at 100 mg/k g/day. The 28

- day mouse study had a very high NOAEL of 920 mg/kg/day. A separate endpoint for Females 13+ is not required. There were no single dose effects identified in the developmental toxicity studies, including the abortions seen in the developmenta l toxicity study in rabbits.

aRfD = 30 mg/kg/day (NOAEL) = 0.30 mg/kg/day

100 (UF)

A.3.2 Chronic Reference Dose (cRfD)

– All Populations

Study Selected: Chronic Toxicity/Carcinogenicity (Feeding)/Rat

MRID No. : 47473386 Executive Summary : See A ppendix A, Guideline [§ 870.4300]

Dose and Endpoint for Establishing cRfD : The NOAEL was 11 mg/kg/day and the LOAEL = 67/86 mg/kg bw/day based on increased liver weight, increased serum phosphate, increased incidences of hepatocyte hypertrophy and eosino philic foci, and thyroid follicular cell hypertrophy, basophilic colloid and epithelial desquamation (♂). In females, it was based onSedaxane (129223) Human Health Risk Assessment D419897, D421932

Page 52 of 76 decreased body weight and body weight gain, increased liver weight and the same thyroid histopathology noted for males.

U F(s): A UF of 100 was applied to account for interspecies extrapolation (10X) and intra

species variation (10X).

Comments about Study/Endpoint/UF: This study provides the lowest NOAEL in the database (most sensitive endpoint) and will also provide the m ost protective limits for human effects. The chronic dog study was also considered, however, the NOAEL was higher at 50 mg/kg/day with a LOAEL of 200 mg/kg/day based on decreased body weights, body weight gains and food consumption, decreased spleen weight s in both sexes, plus decreased glucose.

cRfD = 11 mg/kg/day (NOAEL) = 0.11 mg/kg/day

100 (UF)

A.3.3 Incidental Oral

– All Durations

Study Selected: Acute Neurotoxicity Study

MRID No.: 47473396 Executive Summary : See Appendix A, Guideline [§ 870.6200a]

Dose and Endpoint for Establishing aRfD: The NOAEL of 30 mg/kg/day is based on clinical signs of reduced activity, decreased rearing, initial inactivity, piloerection, ruffled fur and recumbency, decreased body weight, body weight gains and fo od consumption in males at 250 mg/kg. The weakened condition, swaying gait and decreased activity were observed on days 2

- 7, while the other effects were on day 1.

UF(s): A UF of 100 was applied to account for interspecies extrapolation (10X) and intrasp ecies variation (10X).

Comments on Study/Endpoint/UFs : This study provides the lowest NOAEL in the database considered to be valid for this exposure and duration, thus is protective for any potential adverse effects in humans (i.e. 90

- day rat study, SCN study, chronic dog study). The 28

- day dog study was also considered with a higher NOAEL of 50 mg/kg/day, however, the only effect at 250 mg/kg/day was liver vacuolation at 100 mg/kg/day. The 28

- day mouse study had a very high NOAEL of 920 mg/kg/day. The 2

- generation reproductive toxicity study in rats, which is typically used for this endpoint, with an offspring NOAEL of 41 mg/kg/day (offspring LOAEL of 120 mg/kg/day) is also an appropriate study to use for this endpoint. However, the NOAELs
of 30 and 41 m g/kg/day are similar and the NOAEL of 30 mg/kg/day from the ACN is protective of all effects, including all sensitivities. In the future the ACN endpoint could be aggregated.

A.3.4 Dermal

--- All DurationsSedaxane (129223) Human Health Risk Assessment D419897, D421932

Page 53 of 76 A dermal assessment is not required. The 28

- day dermal study had no systemic effects at the limit dose of 1000 mg/kg/day and dermal exposure is limited for a seed treatment.

A.3.5 Inhalation

– All Durations

Study Selected: Acute Neurotoxicity Study

MRID No.: 47473396 Executive Summary : See Appendi x A, Guideline [§ 870.6200a]

Dose and Endpoint for Establishing aRfD: The NOAEL of 30 mg/kg/day is based on clinical signs of reduced activity, decreased rearing, initial inactivity, piloerection, ruffled fur and recumbency, decreased body weight, body weight gains and food consumption in males at the LOAEL of 250 mg/kg.

UF(s): A UF of 100 was applied to account for interspecies extrapolation (10X) and intraspecies variation (10X).

Comments on Study/Endpoint/UFs : There is no inhalation study available. This study provides the lowest NOAEL in the database considered to be valid for this exposure and duration, thus is protective for any potential adverse effects in humans (i.e. 90

- day rat study, SCN study, chronic d og study, chronic rat study). The 28

- day dog study was also considered with a higher NOAEL of 50 mg/kg/day, however, the only effect at 250 mg/kg/day was liver vacuolation at 100 mg/kg/day. The 28

- day mouse study had a very high NOAEL of 920 mg/kg/day.

A .4 Executive Summaries

A.4.1 Sub

- chronic Toxicity

870.3100 90

- Day Oral Toxicity

– Rat

In a sub

- chronic toxicity study (MRID #47473375) , SYN524464 (98.2% a.i.) was administered

to 12 HsdRccHan:WIST (Han Wistar) rats/sex/dose in diet at dose levels of 0, 250, 1000 or 4000 ppm (equal to 0, 18.6, 72.9, 299.6 mg/kg bw/day in males and 0, 21.4, 85.7, 315.3 mg/kg bw/day
in females ) for 90 days.

There were no treatment related clinical signs or ophthalmoscopy findings observed at any dose
level tested. Functio nal observation battery assessments and motor activity were not affected by treatment. There were no treatment related macropathology findings. Body weight, food consumption and food efficiency were decreased in the high

- dose group when compared to control s. Platelet counts were slightly higher for high

- dose females. Plasma triglycerides and total protein were increased in both sexes at the high

- dose. Plasma cholesterol was increased in high

- dose females. Increased absolute and adjusted liver weights, ass ociated with centrilobular hypertrophy and increased pigmentation in the liver, were seen in both sexesSedaxane (129223) Human Health Risk Assessment D419897, D421932

Page 54 of 76 at 4000 ppm. Treatment

- related decreased absolute and adjusted heart weights were observed in high

- dose females.

The LOAEL is 299.6/315.3 mg/kg bw/day males/females, based on decreased body weights, food consumption and food efficiency, increased total protein, increased liver weight, centrilobular hypertrophy and pigmentation in the liver in both sexes, plasma album in in males and increased platelet counts, increased plasma cholesterol and decreased heart weights in females. The NOAEL is 72.9 mg/kg bw/day for males and 85.7 mg/kg bw/day for females.

This sub

- chronic toxicity study in the rat is acceptable and sat isfies the guideline requirement for
a sub

- chronic oral study (OPPTS 870.3100; OECD 408) in rats.

870.3100 13

- Week Oral Toxicity

– Rat

In a sub

- chronic toxicity study ( MRID #47473376) , groups of 10 male and 10 female Crl:WI(Han) (Han Wistar) rats were fed diets containing 0, 300, 2000 or 4000 ppm (0, 24.8, 168.0, 325.1 mg/kg bw/day in males and 0, 28.3, 186.0, 349.8 mg/kg bw/day in females) SYN524464 for a period of at least 90 days. SYN524464 administered daily in the diet for 90 days at doses of up t o 325.1 or 349.8 mg/kg bw/day was generally well tolerated with no mortality and no treatment related clinical signs during weekly examinations.

In male and female animals treated at 325.1 and 349.8 mg/kg bw/day, respectively, body weight, body weight gai n and food consumption were significantly decreased. In females, body weight and body weight gain were decreased at 186.0 mg/kg bw/day. In detailed FOB examinations, males treated at 325.1 mg/kg bw/day showed a statistically significant increase in hunche d posture and piloerection when observed in the arena. Significant decreases were observed in forelimb grip strength in males at 168.0 and 325.1 mg/kg bw/day and females at 186.0 and 349.8 mg/kg bw/day. Decreased hind limb grip strength was observed in fe males at 349.8 mg/kg bw/day. No treatment related effects were observed on motor activity or any other functional observation battery parameter.

At 325.1 and 349.8 mg/kg bw/day administered to males and females, respectively, gamma glutamyl transferase w as increased in both sexes, triglycerides and total protein were increased in males and cholesterol levels were increased in females. Phosphate levels were statistically significantly higher than control values by 29% in 325.1 mg/kg bw/day males.

No tre atment related effects were observed at necropsy. Absolute liver weights and liver weights adjusted for body weight were increased at the high

- dose in males and females. Mild to moderate centrilobular hepatocyte hypertrophy was observed at the high

- dose a ccompanied by minimal to mild hepatocyte pigmentation in both sexes. Minimal to moderate diffuse thyroid follicular cell hypertrophy was observed in 5 males at 325.1 mg/kg bw/day and 1 female at 349.8 mg/kg bw/day.

The LOAEL is 168.0 mg/kg bw/day in males and 186.0 mg/kg bw/day in females, based on decreased body weight and body weight gain in females and decreased forelimb grip strength in both sexes. The NOAEL is 24.8 mg/kg bw/day in males and 28.3 mg/kg bw/day in females.Sedaxane (129223) Human Health Risk Assessment D419897, D421932

Page 55 of 76 This sub

- chronic toxicity st udy in the rat is acceptable and satisfies the guideline requirement for
a sub

- chronic oral study (OPPTS 870.3100; OECD 408) in rats.

870.3100 90

- Day Oral Toxicity

– Mouse

In a sub

- chronic toxicity study (MRID# 47473377)

, SYN524464 ( 95.3% a.i.) was adm inistered in diet to groups of CD

- 1 mice (10/sex) at dose levels of 0, 500, 3500 or 7000 ppm (0, 80, 567, and 1167 mg SYN524464 /kg/day for males and 0, 112, 810, and 1455 mg SYN524464 /kg/day for females, correspondingly) for 90 days.

There were no treatment

- related mortalities, clinical signs, hematology, clinical chemistry, gross pathology or histopathology. At 7000 ppm (1167 mg/kg/day), males had treatment

- related lower body weight and body weight gain, and lower food utilization. Tr eatment

- related decreased white blood cell and lymphocyte counts were also observed at this dose level.

The LOAEL was 7000 ppm in males (1167 mg/kg/day) based on the decreased body weight, lower body weight gain and food utilization, total bilirubin, incr eased liver and testes weights, as well as decreased white blood cell and lymphocyte counts. The NOAEL was 3500 ppm in males (567 mg/kg/day). The NOAEL in females was 7000 ppm, the highest dose tested (1455 mg/kg/day), as no treatment

- related effects were observed. The LOAEL for females was not
determined.

This sub

- chronic toxicity study in the mouse is acceptable and satisfies the guideline requirement
for a sub

- chronic oral study (OPPTS 870.3100; OECD 408) in mice.

870.3150 90

- Day Oral Toxicity

– Dog

In a 13

- week dog study ( MRID #47473378) , SYN524464 (95.3% a.i.) was administered to 4 Beagle dogs/sex/dose by capsule at dose levels 0, 50, 150 or 400 mg/kg bw/day.
There were no treatment

- related effects on survival, clinical signs, ophthalmoscopic para meters, veterinary examinations (patellar reflex, pupillary light reflex, corneal reflex), urinalysis, gross pathology or histopathology.

B ody weight loss was observed during the first week of treatment in males and females at  150 mg/kg/day. Body weights and cumulative body weight gains remained lower than control in both sexes at 400 mg/kg/day and in females at 150 mg/kg/day throughout the study. Decreased body weights were also seen in 50 mg/kg bw/day females starting around day 71/85 and were
associate d with slightly decreased body weight gains. In high

- dose males, decreased body weights were only observed from Days 71 onwards, while in females body weights were decreased compared to controls through most of the study period particularly at the high dos e level. At 400 mg/kg bw/day, these findings were associated with decreased food consumption. The above findings were considered to be treatment

- related and adverse.Sedaxane (129223) Human Health Risk Assessment D419897, D421932

Page 56 of 76 Statistically identified lower total leukocyte, lymphocyte and monocyte counts in female s at

 150 mg/kg/day and lower total leukocytes in males at 400 mg/kg/day were noted during week 13, and were considered to be adverse. Decreased mean absolute and relative spleen weights
were observed in males and females.

The LOAEL in females is 50 mg/kg bw/day, based on body weight loss (Week 1) and decreased body weight gains. The NOAEL in females was not established. The LOAEL in males is 400 mg/kg bw/day, based on decreased body weight, body weight gains and food consumption, decreased lymphocyte counts, as well as decreased spleen weights. The NOAEL in males is 150 mg/kg bw/day.

This study in dogs is acceptable and satisfies the guideline requirement for a 90

- day oral toxicity study in dogs (OPPTS 870.3150; OECD 409).

870.3200 21/28

- Day Der mal Toxicity

– Rat

In a repeat

- dose dermal toxicity study (MRID#47473380), SYN524464 95.3% (a.i.) was applied
to the shaved skin of 10 HanRcc:WIST (SPF) rats/sex/dose at dose levels of 0, 100, 300 or 1000 mg/kg bw/day, 6 hours/day for 5 days/week during a 28

- day period. A functional observational battery (FOB) including grip strength and locomotor activity measurements was conducted during the last week of treatment before the dermal administration for that day. Ophthalmoscopic examinations were performed in all animals during acclimatization and during week 4 in animals of the control and high dose groups.

There were no treatment

- related effects on mortality, body weight, food consumption, clinical signs of toxicity, FOB parameters, ophthalmology, hematology, clinical chemistry, organ weights or gross and histologic pathology.

The LOAEL was not established. The NOAEL is 1000 mg/kg bw/day.

This dermal toxicity study in the rat is acceptable and satisfies the guideline requirement for a
repeat

- dose dermal toxicity study (OPPTS 870.3250 rat); OECD 410 in the rat.

870.3465 90

- Day Inhalation

– Rat

Due to ex tremely high inhalation MOEs of 37,00 0 or greater, a 90

- day inhalation study is not required

.

A.4.2 Prenatal Developmental Toxicity

870.3700a Prenatal Developmental Toxicity Study

– Rat Range Finding StudySedaxane (129223) Human Health Risk Assessment D419897, D421932

Page 57 of 76 In a range

- finding developmental toxicity study ( MRID #47473391 ), SYN524464 (95.3% a.i.) was administered to 10 mated female Wistar rats/dose by gavage in 0.5% CMC (high viscosity) at dose levels of 0, 200, 500, or 750 mg/kg bw/day from days 6 through 20 of gestation. The dams in the groups receiving 500 and 750 mg/kg/day were s acrificed prior to study termination due to ethical reasons. Signs of decreased activity and generally poor clinical condition were noted, and food and body weight gains were statistically significantly reduced. Decreased corrected for gravid uterine weig ht body weight gain and food consumption were
considered to be treatment

- related and adverse at 200 mg/kg bw/day.

The maternal NOAEL was not determined. The maternal LOAEL was 200 mg/kg/day, based on decreased body weight gains and food consumption. At 500 mg/kg bw/day (exceeded MTD), decreased body weight and food consumption, body weight loss; decreased activity, ruffled fur, poor clinical condition, lateral recumbency, uncoordinated movements)

- animals were sacrificed for humane reasons prior to study termination. At 750 mg/kg bw/day, there was one death (GD 11).

The fetal NOAEL or LOAEL w ere not determined.

This study is an acceptable/non

- guideline study for range

- finding purposes.

870.3700a Prenatal Developmental Toxicity Rat Definitive Study

I n a developmental toxicity study (MRID #47473392), SYN524464 (95.3% a.i.) was administered to 24 mated female Han Wistar rats/dose by gavage at dose levels of 0, 25, 100 or 200 mg/kg bw/day in 0.5% CMC high viscosity from days 6 through 20 of gestation.
There were no treatment

- related effects on survival, clinical signs or Caesarean section parameters in maternal animals. At 200 mg/kg bw/day, decreased body weight gains or body weight loss and decreased food consumption were observed. These findings were considered to
be treatment

- related and adverse.

The maternal LOAEL is 200 mg/kg bw/day, based on decreased body weight gains/body weight loss and reduced food consumption. The maternal NOAEL is 100 mg/kg bw/day.

At 200 mg/kg/day, the mean weights of fe male fetuses were statistically significantly lower than controls and considered this finding to be treatment

- related. There were no treatment

- related external, visceral or skeletal malformations or variations.

There were no treatment

- related external, vi sceral or skeletal malformations or variations. The developmental LOAEL was 200 mg/kg bw/day, based on decreased female fetal weights. The developmental NOAEL is 100 mg/kg bw/day.

The developmental toxicity study in the rat is classified acceptable and s atisfies the guideline requirement for a developmental toxicity study (OPPTS 870.3700; OECD 414) in rats.

870.3700b Prenatal Developmental Toxicity Study

– Rabbit Range Finding StudySedaxane (129223) Human Health Risk Assessment D419897, D421932

Page 58 of 76 In a range

- finding developmental toxicity study ( MRID #47473393)

, SYN524464 (95.3% a.i.)
was administered to 10 time

- mated female New Zealand White rabbits in 0.5% (w/v) aqueous high viscosity carboxymethylcellulose (CMC) from gestation days 7 through 28, at doses of 0, 100, 300, 500 mg/kg/day

. There were no treatment

- r elated effects on gravid uterine weights or gross pathology in maternal animals.

Maternal toxicity was manifested by moribundity in the 500 mg/kg/day group, as 2 females were
euthanized on GD 16 following excessive body weight loss, reduced food consumption and decreased defecation. One female was sacrificed after it delivered early on GD 29. Compared to the control group, a dose

- related increase in the incidence of decreased defecation was n oted among surviving females in the 300 and 500 mg/kg/day groups at the daily examinations.

Treatment

- related decreased body weight gains/body weight loss and reduced food consumption

were noted at doses  300 mg/kg bw/day. A dose

- related increase in mean a bsolute and relative (to net body weight) liver weight was noted at all dose levels.

There were no treatment

- related external or visceral malformations or variations.

The maternal NOAEL was 100 mg/kg/day. The maternal LOAEL was 300 mg/kg/day, based on

i ncreased liver weight (histopathology was not conducted), decreased defecation, decreased body weight gain/body weight loss, food consumption. At 500 mg/kg bw/day, the following effects oc c ur r ed: increased liver weight (histopathology was not conducted), d ecreased defecation, decreased body weight gain/body weight loss, food consumption; increased mortality (2♀ on GD 16; 1♀ delivered early on GD 29), preceded by BW loss, decreased food consumption, decreased defecation and soft stool.

The fetal NOAEL was 5 00 mg/kg/day. The fetal LOAEL was not determined, no adverse effects at any dose level based on a limited number of parameters assessed.

Based on the results of this study, dose levels of  300 mg/kg bw/day were considered to be excessive for a main (defi nitive) developmental toxicity study in rabbits.

This study is acceptable/non

- guideline study for range

- finding purposes.

870.3700b Prenatal Developmental Toxicity

- Rabbit Definitive Study

In a developmental toxicity study ( MRID #47473394)

, SYN524464 (95.3% a.i.) was
administered to 25 time

- mated female New Zealand White rabbits/dose by gavage in 0.5% high viscosity carboxymethylcellulose (CMC) at dose levels of 0, 25, 100, or 200 mg/kg bw/day from days 7 through 28 of gestation.

There were no treat ment

- related effects on maternal survival or gross pathology. Increased abortions were noted in 2 females at 200 mg/kg bw/day on GD 24 or 28 and 1 female delivered early on GD 29. These findings were preceded by body weight loss or decreased body weight ga ins, decreased or no food consumption and reduced fecal output, thus not considered to be a single

- dose effect. Similar body weight effects were noted in females at scheduled necropsy.Sedaxane (129223) Human Health Risk Assessment D419897, D421932

Page 59 of 76 The maternal LOAEL is 200 mg/kg bw/day based on increased abortions d ecreased body weight gains or body weight loss, reduced food consumption and decreased defecation. The maternal NOAEL is 100 mg/kg bw/day.

The developmental LOAEL is 200 mg/kg bw/day, based on increased abortions, unossified
sternebrae and 13 th rudimentary ribs. The developmental NOAEL is 100 mg/kg bw/day.

The developmental toxicity study in the rabbit is classified acceptable an d satisfies the guideline requirement for a developmental toxicity study (OPPTS 870.3700; OECD 414)

A.4.3 Reproductive Toxicity

870.3800 Reproduction and Fertility Effects

– Rat Range Finding Study

In a 1

- generation reproduction study (MRID# 47473389) , SYN524464 (95.3% a.i.) was administered to 10 Wistar rats/sex/dose in diet at dose levels of 0, 500, 1500, or 3600 ppm (estimated to be equal to 0, 50, 150 or 360 mg/kg bw/day) for 10 weeks before mating through to weaning of the F 1 generation. After the F 1 generation pups were weaned (lactation day (LD) 28 of age), up to 3/sex/litter from control, 500 and 1500 ppm groups were retained post weaning until LD 35. High dose (3600 ppm) pups/litters were not retained after Day 28 of lactation due to excessive toxicity. The F 1 generation received SYN524464 in the diet at the same nominal dose level as the P generatio n they were selected from.

Parental toxicity:
There were no treatment

- related effects on survival, clinical signs, reproductive parameters (pre

coital interval, number of copulation plugs, fertility, gestation duration, number of litters) or gross path ology.

At doses greater than or equal to 1500 ppm, decreased body weight, body weight gains and food consumption were observed in maternal animals. At necropsy, increased mean liver weights and increased incidences of abnormally darkened livers were noted . These findings were considered
to be treatment

- related and adverse. In males, treatment

- related decreased body weight, body weight gains and food consumption were only observed at 3600 ppm.

The p arental NOAEL was 50 mg/kg/day . The parental LOAEL was 15 0 mg/kg/day, based on decreased body weight, body weight gains, food consumption (♀); increased liver weights, abnormally darkened livers (♀).

Reproductive toxicity:
There were no treatment

- related effects on live birth index or sex ratio.

At 36 00 ppm

, a number of reproductive parameters were affected and included decreased mean implantation sites, decreased number of pups born, increased number of pup deaths (LD 0

- 4), decreased mean litter size, decreased viability and lactation indices, and increased number of missing pups (presumed cannibalized). These findings were considered to be treatment

- related
and adverse.Sedaxane (129223) Human Health Risk Assessment D419897, D421932

Page 60 of 76 The reproductive NOAEL was 150 mg/kg/day . The r epro ductive LOAEL was 360 mg/kg/day (exceeded MTD), based on the following: decreased mean implantation sites, number of pups born; increased number of pup deaths (LD 0

- 4); decreased mean litter size, viability index, lactation index; increased missing pups (presumed cannibalized).

Offspring toxicity:
There were no treatment

- related gross pat hological effects.

At 36 00 ppm , marked decreased body weight and body weight gains were noted in offspring before weaning and after weaning until LD 35. Due to the increased pup toxicity observed at this dose level, the pups were kept with their dams unti l LD 28 at which time, they were sacrificed. At necropsy, increased liver weights were observed in high dose pups compared to
controls and were considered to be treatment

- related. This dose level was considered to approximate the MTD for this type of stu dy.

At 1500 ppm, decreased pup body weights and increased liver weights were observed, and were
considered to be treatment

- related and adverse. No treatment

- related offspring effects were observed at 500 ppm. The offspring NOAEL was 50 mg/kg/day. The off spring LOAEL was 150 mg/kg/day, based on decreased body weights and increased liver weights. At 360 mg/kg bw/day (exceeded MTD), decreased body weight and body weight gains and increased liver weights were also observed. Due to marked effects on body weigh t in P females, low F 1 generation pup body weights and poor pup survival, a dietary level of 3600 ppm was considered to be at or in excess of a MTD in this study.

This study is acceptable/non

- guideline study for use as range

- finding.

870.3800 Reproduc tion and Fertility Effects

– Rat Definitive Study

In a 2

- generation reproduction study ( 47473390) , SYN524464 (95.3% a.i.) was administered to 25 Wistar rats/sex/dose in diet at dose levels of 0, 200, 500 or 1500 ppm (P generation: 0, 16, 41, 120 mg/kg bw/ day in males; 0, 18, 46, 143 mg/kg bw/day in females; F 1 generation: 0, 17, 43, 134 mg/kg bw/day in males; 0, 19, 47, 141 mg/kg bw/day in females). Due to less than optimal pup health, the high dose P generation dams and their F 1 pups remained together unt il lactation day (LD) 28.

In parental animals, there were no treatment

- related effects on survival, clinical signs, food efficiency, estrous cycle length or periodicity, sperm parameters, or reproductive performance (pre

- coital interval, # copulation plu gs, fertility, gestation duration, # litters). In offspring, t here

were no treatment

- related effects on pup viability, litter parameters (including sex ratio), clinical signs, preputial separation or gross pathology.Sedaxane (129223) Human Health Risk Assessment D419897, D421932

Page 61 of 76 At 120 mg/kg bw/day, decreased body weights were observed in F 1 males during the premating period and in females throughout the study. In P generation females, the body weight effects were associated with decreased body weight gains. During the premating period in P generation
males and thro ughout the study in both generations of females, the body weight decrements were associated with decreased food consumption.

Upon necropsy, increased liver weights, enlarged livers (females only) and increased incidence and severity of centrilobular hepto cellular hypertrophy were noted in the high dose parental animals and were considered to be adaptive. At 1500 ppm, decreased ovary weights in F 1 generation females were considered to be adverse.

The parental LOAEL is 1500 ppm (120 mg/kg bw/day in males and 14 1 mg/kg bw/day in females), based on decreased body weights

, body weight gains and food consumption in both sexes and decreased ovary weights in F 1 generation females. The parental NOAEL is 500 p pm (41 mg/kg bw/day in males and 43 mg/kg bw/day in females).

Treatment

- related decreased primordial follicle counts in the P generation females and decreased growing and antral follicle counts in the high dose F 1 generation females were observed in the original study MRID 47473390 . These findings were associated with decreased corpora lutea counts in both generations in the original study MRID 47473390 . The changes in ovarian follicle
counts were associated with increased incidences of females in lactat ional diestrous. The study authors attributed the lack of estrous cyclicity in high dose females to a prolonged suckling period by the pups secondary to systemic toxicity. Review of the individual animal data by the
reviewer did not show a clear correlatio n between the presence of lactational diestrus in dams and decreased follicle counts. However, only a limited subset (N=10) of high dose females was subjected to a quantitative follicle count. Amongst the high dose females assessed, only 4 of
them were in lactational diestrus. Of these females, only female #385 appeared to have lower follicle counts compared to controls and cycling females in the same dose group. The remaining females in the high dose group were cycling and had decreased follicle counts co mpared to the
concurrent controls. Overall, b ased on the weight of evidence of related ovarian effects occurring at the high dose level in this 2

- generation reproductive toxicity study and the presence of

treatment

- related endocrine effects throughout the sedaxane toxicological database, these findings were considered to be treatment

- related and adverse. The decreased ovarian follicle counts had no functional effect on fertility, in the rat.

Syngenta has submitted updated data for the follicle and corpor a lutea counts for the intermediate 200 and 500 ppm doses (D421932). The updated follicle count data, including the intermediate doses at 200 ppm and 500 ppm, are listed below (MRID 49383101, 49383102 ) . The updated results indicate a large decrease in the primordial follicle counts by 34% in the parental generation at 1500 ppm with statistical significance, consistent with the previous results in

MRID 47473390. Additionally in the F1 generation at 1500 ppm, the updated counts indicate a large decrease in the antral follicle counts by 52% and a 28% decrease in the corpora lutea counts, both with statistical significance and also consistent with the previous results in MRID 47473390 (i.e. similar decreases of 53% and 27%, respectively). The updated follicle count data
support the initial conclusion that the ovarian effects occurring at the high dose level in this 2

-Sedaxane (129223) Human Health Risk Assessment D419897, D421932

Page 62 of 76 generation reproductive toxicity study are considered to be treatment

- related , statistically significant and adverse.

Final ovarian staging results

– Counting all control and treated groups (mean number/animal)

Doses SYN524464 (ppm) 0 200 500 1500 0 200 500 1500

P females F1 females

Primordial follicles 240.4 219.70 255.60 158.50** (

- 34%) 235.2 240.0 238.1 247.0

Growing follicles 19.70 15.60 16.20 19.50 (

- 7%) 23.90 15.30 16.50 15.40 (

- 36%)

Antral follicles 10.30 11.20 8.90 9.00 (

- 13%) 10.80 8.60 9.40 5.20** (

- 52%) Corpora lutea 18.30 17.30 16.00 15.50 (

- 15%) 17.20 15.80 15.40 12.30* (

- 28%)

*/** : Statistically significant (*p<0.05; **p<0.01), ANOVA and Dunnett’s test following square root transformation. Data extracted from page 20 of MRID 49383102 study report

The reproductive LOAEL was not determined in males and is 1500 ppm (143 mg/kg bw/day) in females. The reproductive NOAEL in males is 1500 ppm (120 mg/k g bw/day) and in females 500 ppm (46 mg/kg/day).

The statistical increase in post

- implantation loss at 3600 ppm (143 mg/kg bw/day) was
considered adverse. At 143 mg/kg bw/day , treatment

- related decreased pup body weights were observed. Delayed vaginal patency (F 1 ) and increased anogenital distance in F 2 female pups were noted at the same dose level and were considered to be equivocal, based on the small magnitude of the changes. Treatment

- related increased absolute and/or relative liver weights and spleen weights were observed in both generations of pups and were considered to be treatment

- related (histopathology was not conducted).

The offspring NOAEL is 43/47 mg/kg/day. The offspring LOAEL is 1500 ppm (134/1 41 mg/kg bw/day), based on based on a 21% decrease in spleen weights in both sexes, plus a 15% decrease in food consumption , and decreased pup body weights , post implantation loss in F 1 females. The

F 2 ano

- genital distance change of only 8% is not considered adverse.

This study is acceptable and satisfies the guideline requirement for a 2

- generat ion reproductive study (OPPTS 870.3800; OECD 416) in rats.

A.4.4 Chronic Toxicity

870.4100a (870.4300) Chronic Toxicity

– Rat

– See A.4.5

870.4100b Chronic Toxicity

– Dog

In a 52

- week dog study ( MRID #47473379)

, SYN524464 (95.3% a.i.) was administered to 4 Beagle dogs/sex/dose by capsule at dose levels of 0, 15, 50, 200 mg/kg bw/day.Sedaxane (129223) Human Health Risk Assessment D419897, D421932

Page 63 of 76 There were no treatment

- related effects on survival, clinical signs, ophthalmoscopic parameters, veterinary examinations (patellar reflex, pupillary light reflex, corneal reflex), hematology, urinalysis, organ weights or gross pathology or histopathology.

At 200 mg/kg bw/day, decreased body weights were observed in both sexes with the effect being more pronounced in females. Body weight loss occurred during Week 1 of the study. Following an extended feeding period, animals consumed more food but a patter n of decreased body weight gains was observed for the remainder of the study. The body weight effects were associated with decreased food consumption. Treatment

- related clinical chemistry findings included decreased glucose levels in males. Decreased absol ute and relative testes weights at 200 mg/kg bw/day and
were considered to be treatment

- related. Decreases in mean spleen weights in both sexes at 200 mg/kg bw/day and considered to be adverse.

The LOAEL is 200 mg/kg bw/day based on decreased body weights , body weight gains and food consumption in both sexes, decreased glucose levels in males, decreased testes weights and decreased spleen weights in both sexes. The NOAEL is 50 mg/kg bw/day.

This study is classified as acceptable/guideline and satisfies th e guideline requirements for a chronic toxicity study (non

- rodent).

A.4.5 Carcinogenicity

870.4300 Carcinogenicity/Chronic Study

– Rat

In a chronic toxicity study ( MRID #47473386) , SYN524464 (95.3% a.i.) was administered to 52 Crl:WI(Han) (Han Wistar) rats/sex/dose in diet at dose levels of 0, 200, 1200 or 3600 ppm (0, 11, 67 or 218 mg/kg bw/day in males and 0, 14, 86 or 261 mg/kg bw/day in females; designated as control, low, mid or high dose respectively) for at least 104 consecutive weeks. In addi tion, a toxicity study comprising 12 Han Wistar rats/sex/dose were included and dosed in an identical fashion for a period of 52 consecutive weeks.

There were no treatment

- related effects on survival, clinical signs, ophthalmoscopic parameters,
motor acti vity, urinalysis or gross pathology.

A decrease in bodyweight and bodyweight gain was observed in males at 218 mg/kg bw/day and in females at 86 and 261 mg/kg bw/day. A corresponding decrease in food consumption and food efficiency was observed in both s exes at the high

- dose.

The only treatment

- related effect observed in the Functional Observation Battery (FOB) was decreased hindlimb grip strength in males at 67 and 218 mg/kg bw/day. This finding was considered to be equivocal. Increased gamma glutamyl transferase (GGT), glucose and phosphate levels were observed in males at 218 mg/kg bw/day. Increased phosphate is

cons idered to be treatment related at  67 mg/kg bw/day in males.Sedaxane (129223) Human Health Risk Assessment D419897, D421932

Page 64 of 76 A dose related statistically significant increase in absolute and adjuste d liver weight, (adjusted for body weight by covariate analysis) was seen at  67/86 mg/kg bw/day M/F. In males, this was associated with increased hepatocyte hypertrophy and eosinophilic foci. At the high

- dose level, minimal to moderate centrilobular hepa tocyte hypertrophy and increased incidence of pigment in centrilobular or mid

- zonal hepatocytes in the liver were seen at week 52 in both sexes and only in females at week 104. Increased incidences of thyroid follicular cell hypertrophy and epithelial desq uamation were seen in both sexes dosed at 67 or 86 mg/kg bw/day and above. Increased epithelial tubular hyperplasia of the thymus was observed in high

- dose females. Increased incidences of thyroid follicular cell adenomas and liver hepatocellular adenoma s were observed at 218 mg/kg bw/day. An increased incidence of uterine adenocarcinomas was observed in females at 261 mg/kg bw/day. These tumors were considered to be treatment

- related by the Canada PMRA and US EPA.

The NOAEL is 11 mg/kg bw/day in males and 14 mg/kg bw/day in females. The LOAEL is 67 mg/kg bw/day in males, increased liver weight, increased incidences of hepatocyte hypertrophy and eosinophilic foci, and thyroid follicular cell hypertrophy, basophilic colloid and epithelial desquamation. T he LOAEL is 86 mg/kg bw/day in females, based on decreased body weight and body weight gain, increased liver weight and the same thyroid histopathology noted above
for males.

There was evidence of carcinogenicity after treatment with SYN524464 at 218 mg/k g bw/day in males and 261 mg/kg bw/day in females. Dosing was considered to be adequate, but not excessive, to assess the carcinogenicity of sedaxane.

This chronic study in the rat is acceptable and satisfies the guideline requirement for a chronic
oral study (OPPTS 870.4300), OECD 453 in rat.

870.4200b Carcinogenicity (Feeding)

– Mouse

In a carcinogenicity study ( MRID #47473388)

, SYN524464 (Sedaxane) ( 95.3% a.i.) was administered in diet to groups of CD

- 1 mice (50/sex/group) at dose levels of 0, 200, 1250 or 7000 ppm (0, 25, 157, and 900 mg SYN524464 /kg/day for males and 0, 29, 185, and 1001 mg
SYN524464 /kg/day for females) for 80 weeks.

Dietary administration of SYN524464 at 7000 ppm (900/1001 mg/kg bw/day M/F) resulted in

treatment

- related lower bo dy weights and body weight gains for males and females. The body weight decrements were not considered to be adverse since they were less than 10%.

Treatment

- related increased incidences of hepatocellular adenomas and/or carcinomas were seen
in male mice a t 7000 ppm (900/1001 mg/kg bw/day M/F), a dose level that approached a limit dose, compared to controls No treatment

- related neoplastic or non

- neoplastic micropathological changes of the liver were observed at lower doses in males or in females. Dosing was considered to be adequate based on decreased body weight/gains and decreased food utilization in the initial stages of the study.

The LOAEL for SYN524464 was 7000 ppm for both sexes (900 mg/kg/day for males and 1001 mg/kg/day for females) based on lower body weights body weight gains and food efficiency. TheSedaxane (129223) Human Health Risk Assessment D419897, D421932

Page 65 of 76 NOAEL for SYN524464 was 1250 ppm for both sexes (157 mg /kg/day in males and 185 mg /kg/day in females).

There was evidence of carcinogenicity after treatment with SYN524464 at 900 mg/kg bw/day in males. In both males and female rats, the high dose of 7000 ppm was considered to be adequate to assess the carcinogenicity of sedaxane.

This carcinogenicity study in the mouse is acceptable and satisfies the guideline requirement for a carcinogenicity study (OPPTS 870.4200; OECD 451) in mice.

A.4.6 Mutagenicity

Sedaxane was negative in the mutagenicit y studies. H owever , chro mosomal aberration s were observed at cytotoxic concentrations in one in vitro study

. Study Dose Levels Result

In vitro studies

870.5100

Bacterial Reverse Mutation

MRID#1897888
Sokolowski, A (2009) 0

- 5000 μg/plate Negative

870.5375

In vitro Cytogenetics

MRID# 47473382 Bohnenberger S (2009) 0

– 216.8 μg/mL Negative

870.5300
Mammalian cell gene mutation (mouse lymphoma)

MRID #47473383
Wollny H

- E (2009) 0

- 110 μg/mL Negative

In vivo studies

870.5395

Mouse Bone Marrow Micronucleus Assay

MRID#47473384
Reichenbach M (2010) 0

- 2000 mg/kg bw Negative

870.5550
Unscheduled DNA synthesis

– Rat
Liver

MRID#4743385
Durward R (2009) 0

- 2000 mg/kg bw Negative

A.4.7 Neurotoxicity

870.6100 Delayed Neurotoxicity Study

– Hen

- NA

870.6200a Acute Neurotoxicity Screening Battery

- Rat Range Finding StudySedaxane (129223) Human Health Risk Assessment D419897, D421932

Page 66 of 76 In a range

- finding acute neurotoxicity study (MRID #47473395), groups of unfasted 7

- 8 week old HanRcc:Wistar (SPF) rats (3/sex) were given a single oral dose of SYN524464 (95.3% a.i.)
in 0.5% w/v car

boxymethylcellulose (CMC), high viscosity grade, in distilled water at doses of 0, 80, 1000 or 2000 mg/kg bw and observed for 8 days. A limited functional observation battery (FOB) was performed on all animals on day 1 at approximately hourly intervals for 8 hours, and once daily on days 2 to 8. There were no treatment

- related effects on survival or gross pathology.

Treatment

- related reduced activity, hunched posture, spasms, piloerection and uncoordinated movements were observed after dosing at  1000 mg/kg bw/day, with a peak effect at 3 hours
post

- dose. In females, incidences of piloerection persisted beyond day 4. Treatment

- related decreased body weight and body weight gains were also observed for several days post

- dosing but resolved by the end of the study. At 80 mg/kg bw, piloerection was observed from 2

- 8 hours
post

- dose on day 1 only; hunched posture, spasms and reduced activity were also noted sporadically on day 1.

A NOAEL was n ot determined . The LOAEL was 80 mg/kg, based on increased piloe rection (2

- 8 h post

- dose); hunched posture, spasms, reduced activity also noted sporadically
At 1000 and 2000 mg/kg bw, increased piloerection (2

- 8 h ♂, beyond day 4 ♀ post

- dose); hunched posture, spasms, reduced activity, reduced activity, hunched posture , spasms, piloerection, uncoordinated movements (peak effect at 3 h post

- dose), decreased body weight and body weight gains.

Based on the results of this preliminary study, a single oral dose of 2000 mg/kg SYN524464 would be an appropriate high dose for an acute neurotoxicity study in the rat. The estimated time of peak effect is 3 hours after dosing.

The study is classified a s acceptable/non

- guideline for a range

- finding acute neurotoxicity study

870.6200a Acute Neurotoxicity Screening Battery

- Rat D efinitive Study

In an acute neurotoxicity study ( MRID #47473396) , groups of unfasted young adult
HanRcc:Wistar (SPF) rats (10/sex) were given a single oral dose of SYN524464 (95.3% a.i.) in 0.5% w/v carboxymethylcellulose (CMC), high viscosity grade at doses of 0, 30, 250 or 2000 mg/kg bw and observed for 15 days. Neurobehavioral assessment (functional observation battery and motor activity testing) was performed in 10 animals/sex/group on Days 1 (approximately 2

- 4 hours after dosing), 8 and 15. At study termination, 5 animals/sex/group were euthanized and perfused in situ for neuropathological examination. Of the perfused animals, all animals in each group were subjected to histopathological evaluation of brain and peripheral nervous system
tissues.

There were no treatment

- related effects on landing foot splay, brain weights, gross pathology or neuropathology.

A t 2000 mg/kg bw, clinical signs of toxicity were observed in both males (4/10) and females (3/10); these animals were sacrificed moribund at 6 hours post

- dose. In female survivors,Sedaxane (129223) Human Health Risk Assessment D419897, D421932

Page 67 of 76 treatment

- related decreased body weight and body weight gains and reduced f ood consumption were noted. Associated clinical signs included in both sexes included bradynpea and hunched posture. In males, increased incidences of rough coat, weakened condition, hunched posture, reduced muscle tone were observed; increased incidences of ruffled fur, prostration, hunched posture and abnormal gait were noted in females. All clinical signs occurred during Week 1 post

dose. Treatment

- related decreased grip strength in both the fore

- and hind

- limbs were observed in high dose animals on day 1.
At 250 and 2000 mg/kg bw, evidence of toxicity included clinical observations such as reduced activity, decreased rearing, as well as increased initial inactivity and piloerection in both sexes.

Treatment

- related increased incidences of ruffled fur and recumbency were observed in males, while in females, noted clinical observations included weakened condition, swaying gait, decreased activity and reduced muscle tone. T reatment

- related decreased body weight and body weight gains and reduced food consumpt ion were noted in males at this dose level. No treatment

related findings were evident in any of the surviving rats during the second week of the study. At 2000 mg/kg, there was a decrease in rectal temperature.

At study termination, no neurohistopatholog ical lesions were present. The 2000 mg/kg bw dose level slightly exceeded the desired high dose for an acute neurotoxicity study but the study was still considered to be acceptable.

The LOAEL is 250 mg/kg bw in males, based on reduced activity, decreas ed rearing, initial inactivity, piloerection in both sexes; ruffled fur and recumbency, decreased body weight, body weight gains and food consumption. The NOAEL is 30 mg/kg bw/day in males. The LOAEL in females is 30 mg/kg bw based on decreased forelimb gr ip strength, but the NOAEL was not
established.

The study is classified as an acceptable/guideline study for an acute neurotoxicity study in rats (870.6200).

870.6200b Sub

- chronic Neurotoxicity Screening Battery

- Rat Range Finding Study

I n a range

- finding sub

- chronic neurotoxicity study ( MRID #47473397) , SYN524464 (95.3% a.i.) was a dministered to 8 Wistar rats/sex/group via the diet at dose levels of 0, 500, 2000 or 5000 ppm (equal to 0, 37.8, 153.5, 360.1 mg/kg bw/day in males and 0, 40.1, 156.4, 338.8 mg/kg bw/day in females) for 28 days. No neurobehavioral assessments were performed in this range

- finding test. At study termination, all animals were euthanized and subjected to a gross examination.

All rats survived until scheduled ter mination. There were no treatment

- related effects on clinical signs, detailed behavioral observations or gross pathology.

Reduced food intake and decreased body weight and body weight gains were observed in males and females at 5000 ppm (360.1/338.8 mg/k g bw/day M/F) and females at 2000 ppm (156.4 mg/kg bw/day). Food efficiency was decreased in males and females at  2000 ppm (153.5/156.4 mg/kg bw/day M/F). There were no treatment

- related effects in either sex at 500 ppm (37.8/40.1 mg/kg bw/day M/F).Sedaxane (129223) Human Health Risk Assessment D419897, D421932

Page 68 of 76 Th e NOAEL was 37.8 mg/kg/day . The LOAEL was 153.5/156.4 mg/kg/day, based on decreased food efficiency, body weight (♀), body weight gain (♀), food consumption (♀). At 360.1/338.8 mg/kg bw/day ♂/♀, decreased body weight, body weight gain, food consumption. No neurobehavioral were performed in this range

- finding study.

The study is classified as acceptable/non

- guideline study as a range

- finding sub

- chronic

ne urotoxicity study in rats.

870.6200b Sub

- chronic Neurotoxicity Screening Battery

- Rat Definitive St udy

In a sub

- chronic neurotoxicity study ( MRID #47473398) , SYN524464 (95.3% a.i.) was
administered to 12 HanRcc:WIST (SPF) rats /sex/group in the diet at 0, 300, 1000 or 4000 ppm (equal to 0, 19.7, 66.0, 260.0 mg/kg bw/day in males and 0, 24.3, 79.7 or 302.9 mg/kg bw/day in females) for 92 days. D etailed clinical observations were performed on all animals once prior to study start and once weekly thereafter. Furthermore, a neurobe havioral assessment including a functional observation battery (FOB) and quan titative assessments of landing foot splay, sensory perception and muscle weakness, and an assessment of locomotor activity were performed in all animals once prior to study start , and in weeks 2, 5, 9 and 13.

At study termination, 5 animals/sex/group were sacrificed and perfuse d in situ for the assessment of brain weight, macroscopic changes and neuropathological examination. All perfused animals of the high dose and control groups were subjected to histopathological evaluation of brain and peripheral nervous system tissues. Any remaining un

- perfused animals were sacrificed and
discarded.
There were no treatment

- related effects on survival, clinical signs, detailed behavioral observations, ophthalmoscopic parameters, FOB, body temperature, grip strength, landing foot splay, brain weight, gr oss pathology or neuropathology.

Treatment

- related decreases in body weight, body weight gains, food consumption and food efficiency were observed at the high dose level (260.0 mg/kg bw/day in males, 302.9 mg/kg bw/day in females) throughout the study per iod. Decreases in mean locomotor activity (total distance travelled) were noted at the same dose level and were considered to be treatment

- related
and adverse.

The LOAEL is 260.0/302.9 mg/kg bw/day M/F, based on decreased body weight, body weight gains, food consumption and food efficiency, as well as reduced locomotor activity. The NOAEL is 66.0/79.7 mg/kg bw/day M/F.

The study is classified as acceptable as an acute neurotoxicity study in rats (870.6200).

870.6300 Developmental Neurotoxicity Study

- NA

-Sedaxane (129223) Human Health Risk Assessment D419897, D421932

Page 69 of 76 A.4.8 Metabolism

870.7485 Metabolism

- Rat

Excretion and Tissue Distribution in the Rat Following Single Oral Administration of 1 mg or 80 mg [Pyrazole

- 5

- 14 C]

- SYN524464/kg (MRID #47473359)

Recoveries of radioactivity ranged between 96.3

- 104.9% AD, with no significant differences in tissue distribution or excretion between the dose levels. The primary route of excretion of [pyrazole

14 C]

- SYN524464 was via the feces in both sexes, with urinary excretion slightly higher in females. The absorbed radioactivity was rapidly distributed throughout the tissues and rapidly cleared without accumulation of radio

- labelled SYN524464 in the tissues.

The study is classified as acceptable as a metabolism study in rats (870.7485).

Pharmacokinetics in the Rat following a Single Oral Administration of 1 mg or 80 mg [Pyrazole

5

- 14 C]

- SYN524464/kg (MRID #47473355)

A mean of 91.6% or 97.2% AD was eliminated in urine and feces over 72 h by male and female rats. The major route of elimination was via the feces; however, urinary elimination was also an important route of excretion in both sexes and slightly more pronounced in females compared to
males.

Recoveries of radioactivity ranged between 91.5

- 101.1% AD. Concentrations of [pyrazole

- 5

- 14 C]

- SYN524464 w ere slightly higher in plasma than in whole blood at most time points, suggesting that total radioactivity was relatively evenly distributed between them. In general, T max was achieved at 1

- 6 h post dose and declined with estimated terminal half

- life
value s ranging from 22.65

- 28.76 h. Terminal half

- life values of 20.71

- 39.86 h were obtained for
blood.

There were no apparent differences in the AUC and C max values between genders, or between the dose levels. As doses of [pyrazole

- 5

- 14 C]

- SYN524464 were incr eased from 1 to 80 mg/kg bw, systemic exposure to total radioactivity exhibited a 118

- 140 fold increase but, due to the observed variability in the concentrations for individual rats, this was not considered significant.

The study is classified as accepta ble as a metabolism study in rats (870.7485).

Excretion in Bile Duct Cannulated Rats Following Single Oral Administration of 1 mg or 80 mg [Pyrazole

- 5

- 14 C]

- SYN524464/kg (MRID #47473357)

The majority of the administered radioactivity was excreted within the first day post

- dose for both dose levels. Absorption was estimated to be 87

- 89% AD in males and 88

- 92% AD and females. Fecal excretion and gastrointestinal tract contents were less than 7% AD. BiliarySedaxane (129223) Human Health Risk Assessment D419897, D421932

Page 70 of 76 excretion represented the predominant excretion ro ute for both sexes at 79

- 82% AD. Urinary excretion of the absorbed dose was limited, accounting for approximately 6

- 7% AD in males and

7

- 10% AD in females.

The study is classified as acceptable as a metabolism study in rats (870.7485).

Excretion in Bile Duct Cannulated Rats Following Single Oral Administration of 1 mg or 80 mg [Phenyl

- U

14 C]

- SYN524464/kg (MRID #47473360)

There were no significant differences in absorption and elimination patterns between dose levels or between genders. For both dose groups, the majority of the administered radioactivity was excreted within the first day post

- dose and biliary excretion represented about 79

- 85% AD, with urinary excretion , accounting for approximately 5

- 8% AD. Absorption was estimated to be 87

- 94% AD (urine radioactivity, cage washes, bile and residual carcass) with fecal excretion and GI
tract contents were less than 7% AD.

The study is classified as acceptable as a metabolism study in rats (870.7485).

Tissue Depletion in the Rat Following Single O ral Administration of 1 mg or 80 mg [Pyrazole

- 5

- 14 C]

- SYN524464/kg (MRID #47473358)

The tissue distribution of a single oral dose of 1 or 80 mg [pyrazole

- 5

- 14 C]

- SYN524464/kg bw
was extensive. Plasma half

- lives ranged from 25.84

- 32.33 h for both dose group and half

- lives in the whole blood ranged from 29.49

- 40.10 h. Tissue concentrations of radioactivity were highest at 1

- 1.5 h for low dose and 5 h for high dose with progressively decreased thereafter with
elimination half lives of 0.1

- 3.2 days. Most mean tissue concentrations were near the limit of reliable measurement by 96 h post dose. The high levels of radioactivity in the gastrointestinal tract and its contents were consistent with the established biliary elimination and fecal excretion
of SYN524464 metabolites. There were no pronounced sex differences in tissue distribution, depletion profiles, or half

- lives of elimination in the plasma or whole blood.

The study is classified as acceptable as a metabolism study in rats (870.7485).

Investigation of the Nature and Identity of Radiolabelled Metabolites Present in Plasma, Urine, Faeces and Bile Collected from Rats Following Oral Administration of [ 14 C]

- SYN524464 (MRID #47473356)

The major metabolites were the trans para phenol CSCD658906 and the des methyl trans para phenol CSCD659087 which together with the equivalent cis para phenol isomers. SYN524464 was extensively metabolized by rats through demethylation, hydroxylation, oxidation and conjugation pathways resulting in a number of hydroxylated met abolites and metabolites formed by cleavage of the terminal cyclopropyl moiety. Glucuronic acid, sulphate and glutathione conjugates were also formed. CSCD659090 and CSCD668404 accounted for approximately half
the administered dose.Sedaxane (129223) Human Health Risk Assessment D419897, D421932

Page 71 of 76 The study is classi fied as acceptable as a metabolism study in rats (870.7485).

Tissue Distribution and Elimination in the Rat Following Repeated Daily Oral Administration of 1 mg [Pyrazole

- 5

- 14 C]

- SYN524464/kg ( MRID #47473362)

The majority of the oral administered radioact ivity was excreted via the feces at 60.9% AD over the 24 h collection period, with urinary excretion at 13.0% AD. Recovery of administered radioactivity was incomplete by 24 h post

- dose with a mean of 75.7% AD. Similar results were
obtained after 14 dail y dosings, with some of the dosing from day 13 also contributing to the day
14 elimination.

Tissue concentrations of radioactivity were highest at 24 h following the fourteenth and final dose with the exception of whole blood and plasma, for which the highest mean concentrations
were observed 24 h after the tenth dose. The liver and kidney had the highest levels after 14 daily dosings, respectively. Most mean tissue concentrations appeared either to have attained or to be approaching steady state kinet ics by the end of the 14 day dosing period. The high levels of radioactivity in the gastrointestinal tract and its contents were consistent with the established biliary elimination and fecal excretion of SYN524464 metabolites. There were no pronounced

sex differences in tissue distribution, depletion profiles, or half

- lives of elimination in the plasma
or whole blood.

The study is classified as acceptable as a metabolism study in rats (870.7485).

870.7600 Dermal Absorption

– Rat

The objective of this study (MRID # 47473632 ) was to investigate the in vivo dermal absorption of [ 14 C]

- SYN524464 through rat skin. Dose preparations equivalent to a SYN524464 FS Formulation concentrate (A16148C) and two aqueous end

- use dilutions thereof (nominally 1/20
and 1/200) were prepared and supplied by Dermal Technology Laboratory Ltd. Each dose application site of 10 cm 2 per rat was defined and protected by an O

- ring glued to the clipped skin surface. For each dose preparation, 100 μL was applied to the skin of eac h of sixteen animals per dose level (48 rats in total), corresponding to nominal doses of 50, 2.5 and 0.25 mg [ 14 C]

- SYN524464 per rat. Each dosing device incorporated a non

- occlusive gauze cover. The dermal absorption of radioactivity was followed during a 6 hour exposure interval after application and over a total time course of 120 hours. Rats were housed individually in metabolism cages for the collection of excreta.

The application sites on all rats were washed after the 6 hour exposure interval wit h soap and water to remove the unabsorbed dose. Urine, faeces and a cage wash were collected from each cage after the skin wash and at intervals for the duration of each experiment. Sub

- groups of four rats were terminated immediately after the 6 hour exp osure interval and after 24, 72 and

120 hours. Cardiac blood samples were collected under terminal anaesthesia. The liver, kidneys and representative samples of adipose tissue and muscle were taken for analysis. Each application skin site was excised an d sequentially tape

- stripped to remove the stratum corneum

. All samples, including residual carcasses were analyzed for radioactivity.Sedaxane (129223) Human Health Risk Assessment D419897, D421932

Page 72 of 76 The group mean achieved doses were 56.5 mg (491 kBq), 2.51 mg (509 kBq) and 0.250 mg (519 kBq) of [ 14 C]

- SYN524464 per rat for the formulation concentrate, 1/20 dilution and 1/200 dilution respectively. These compared well with the target doses.

In the experiment with the formulation concentrate, most of the applied radioactivity remained unabsorbed following the 6 hour exposure interval and was readily washed from the skin surface using mild soap solution and water. Approximately 0.15% of the dose was associated with the
skin and stratum corneum of the application site following the 6 hour skin wash; this declined to

0. 07% after 120 hours, showing that the residues could be absorbed. The absorbed dose amounted to 0.08% after 6 hours, 0.10% after 24 hours, 0.17% after 72 hours and 0.24% after 120 hours. The dermal absorption, calculated by adding the potentially absorbab le dose (application site skin and stratum corneum ) with the absorbed dose, was 0.23%, 0.23%, 0.30 and 0.31% after 6, 24, 72 and 120 hours, respectively.

Following dermal exposure to the 1/20 aqueous dilution for 6 hours, a mean of 96.3% of the applied ra dioactivity was removed by skin washing. In the rats terminated at 6 hours, the radioactivity present in the stratum corneum and skin beneath the application sites amounted to 1.47% of the dose. This declined slightly to 0.41% after 120 hours, which was evidence that residues could be absorbed. The absorbed dose amounted to 1.22% after the 6 hour exposure period, 0.89% after 24 hours, 3.11% after 72 hours and 1.25% after 120 hours. The dermal absorption, calculated by adding the potentially absorbable d ose (application site skin and

stratum corneum ) with the absorbed dose, was 2.69%, 1.68%, 3.75% and 1.67% after 6, 24, 72 and 120 hours, respectively.

Following application of the 1/200 aqueous dilution, a mean of 93.6% of the applied radioactivity was re adily washed from the skin surface after the 6 hour exposure interval (in rats terminated at 6 hours), and was readily washed from the skin surface. The potentially absorbable
skin residue declined from 4.55% of the dose after 6 hours to 2.04% after 120 h ours. The percentage of dose absorbed from this dilution accounted for 3.51, 4.31, 3.90 and 4.88% of the dose after 6, 24, 72 and 120 hours respectively. The dermal absorption, calculated by adding the potentially absorbable dose with the absorbed dose, w as 8.05%, 6.72%, 5.19% and 6.92% after 6, 24, 72 and 120 hours, respectively.

Following a dermal exposure interval of 6 hours to SYN524464 FS formulation concentrate (A16148C), virtually all of the applied dose was readily removed from the skin surface by mild skin washing. Dermal absorption of SYN524464 accounted for 0.23% of the dose after 6 hours
and 0.31% after 120 hours. Following a 6 hour exposure to a 1/20 aqueous dilution, dermal absorption represented 2.69% of the dose after 6 hours and 1.67% af ter 120 hours. Following a 6 hour exposure to a 1/200 aqueous dilution, dermal absorption represented 8.05% of the dose
after 6 hours and 6.92% after 120 hours.

A.4.9 Immunotoxicity

870.7800 Immunotoxicity

In an immunotoxicity study ( MRID #47473405) , SYN524464 (95.3% a.i.,) was administered to 10 Crl:CD1 (ICR) male mice/dose in the diet at concentrations of 0, 500, 2000 or 5500 ppm (0,Sedaxane (129223) Human Health Risk Assessment D419897, D421932

Page 73 of 76 93, 367.3 or 1080.1 mg/kg bw/day) for 28 consecutive days. An additional group of mice were
administered the positive control substance, cyclophosphamide monohydrate (CPS), via intraperitoneal injection (50 mg/kg/day) for 4 consecutive days (study days 24 through 27). The vehicle control and positive control groups (Groups 1 and 5, respectively) were offered the basal
diet for a minimum of 28 consecutive days. All mice were immunized with an intravenous injection of sRBC on study day 24, approximately 96 hours prior to the scheduled necropsy. All animals were euthanized on study day 28.

All animals survi ved to the scheduled necropsy. There were no test substance

- related clinical
observations. There were no test substance

- related effects on body weights, food consumption, or macroscopic findings. There was an increase in relative spleen weights and gros s and relative thymus weights in high

- dose animals, but not statistically significant. In the antibody formation cell assay, there was an increase in antibody formation at 5500 ppm.

Sedaxane did not elicit immunosuppressant effects. The positive contro l cyclophosphamide demonstrated response of the assay to a known immunotoxicant.

NOAEL=1080 mg/kg/day

, LOAEL=Not determin ed, no decrease in TDAR assay, s pleen and thymus weight changes not statistically significant ( high coefficients of variation noted f or IgM data).Sedaxane (129223) Human Health Risk Assessment D419897, D421932

Page 74 of 76 A ppendix B. Metabolism Data

B1. Structures and Identity of Metabolites of Sedaxane

Appendix B.1

. Test Compound Nomenclature

. Compound Chemical Structure

Common name: Sedaxane

CAS name: N

- [2

- [1,1′

- bicyclopropyl]

- 2

- ylphenyl]

- 3

- (difluoromethyl)

- 1

- methyl

- 1 H

pyrazole

- 4

- carboxamide

IUPAC Name: Mixture of cis isomers 2’

- [(RS,2RS)

- 1,1’

- bicycloprop

- 2

- yl]

- 3

- (difluoromethyl)

- 1

- methylpyrazole

- 4

- carboxanilide and trans isomer 2’

- [(RS,2SR)

- 1,1’

- bicyc loprop

- 2

- yl]

- 3

- (difluoromethyl)

- 1

- methylpyrazole

- 4

- carboxanilide Mixture of trans (SYN508210) and cis (SYN508211) isomers

Company name: CSCD658906

IUPAC Name: N

- {2

- [(1 R ,2 S )

- 1,1'

- bi(cyclopropyl)

- 2

- yl]phenyl}

- 1

- methyl

- 3

- (trifluoromethyl)

- 1 H

- pyrazole

- 4

- carboxamide

Company name: CSCC210616

IUPAC Name: 3

- (difluoromethyl)

- 1H

pyrazole

- 4

- amide

Company name: CSCD465008

IUPAC Name: 3

- (difluoromethyl)

- 1H

pyrazole

- 4

- carboxylic acid

Company name: CSAA798670

IUPAC Name: 3

- (difluoromethyl)

- 1

- methyl

1 H

- pyrazole

- 4

- carboxylic acidSedaxane (129223) Human Health Risk Assessment D419897, D421932

Page 75 of 76 Appendix B.1

. Test Compound Nomenclature

. Compound Chemical Structure

Company name: CSCD668094

IUPAC Name: N

- [2

- (3

- cyclopropyl

- 1,3

- dihydroxypropyl)phenyl]

- 3

- (difluoromethyl)

- 1

- methyl

- 1 H

- pyrazole

- 4

- carboxamide

Company name: CSCD668095

IUPAC Name: 3

- [2

- ({[3

- (difluoromethyl)

- 1

- methyl

- 1 H

- pyrazol

- 4

- yl]carbonyl}amino)phenyl]

- 3

- hydroxypropanoic acidSedaxane (129223) Human Health Risk Assessment D419897, D421932

Page 76 of 76 Appendix C. Physical/Chemical Properties

Table C.1

. Physicochemical Properties of Sedaxane.

Parameter Value Reference Melting point 121.4  ̊C

D382350, A. Abramovitch,

11/2/2011 pH 5.9 at 1.0 % w/v (25 °C)

Density 1.23x 10 3 kg/m 3 at 20°C corresponding to a relative density of 1.23 Water solubility 14 mg/L

Solvent solubility (at 25°C) Acetone

– 410 g/L
Dichloromethane

– 500 g/L Ethyl acetate hexane

– 200 g/L
Methanol

– 410 mg/L
Octanol

– 110 g/L
Toluene

– 20 g/L Vapor pressure At 20°C, 6.5x10

- 8 Pa At 25°C, 1.7x10

- 7 Pa

Dissociation constant (pK
a ) No pKa found in the range of 1.0 to 12.0 by spectro

- photometric titration of a
solution of sedaxane in water

Octanol/water partition coefficient Log(K OW ) log K OW @ 25°C = 3.3

Henry’s Law Constant At 25°C, 4.0 x10

- 6 Pa m 3 /mol

UV/visible absorption spectrum Neutral, acidic and basic solutions:


max = 225, 265, and 295 nm

Appendix D

. Review of Human Research

This risk assessment relies in part on data from studies in which adult human subjects were intentionally exposed to a pesticide or other chemical. These studies, which form the basis of the
Seed Treatment SOPs

, have been determined to require a review of their ethical conduct, have received that review, and have been determined to be ethical

.