Cyflumetofen Human Health Risk Assessment DP No. D398246

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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C. 20460

OFFICE OF

CHEMICAL SAFETY AND

POLLUTION PREVENTION

MEMORANDUM

Date: 14 January 2014

Subject: Cyflumetofen. Revised New Active Ingredient Human Health Risk Assessment 

to Support Uses on Citrus (Crop Group 10-10), Pome Fruits (Crop Group 11-10), 

Tree Nuts (Crop Group 14-12), Grape, Strawberry, and Tomato.

PC Code: 138831 DP Barcode: D398246

Decision No.: 459424 Registration No.: 7969-GGA, 7959-GGT, 7969-GGL

Petition No.: 2F7973 Regulatory Action: Section 3 Registration

Risk Assessment Type: Single Chemical / Aggregate Case No.: NA

TXR No.: NA CAS No.: 400882-07-7

MRID No.: NA 40 CFR: TBD

From: Donald Wilbur, Chemist/Risk Assessor

Shalu Shelat, Industrial Hygienist

Yung Yang, Ph.D., Toxicologist

Risk Assessment Branch VI

Health Effects Division (7509P)

Through: Anna Lowit, Senior Toxicologist

Dana Vogel, Deputy Division Director

Risk Assessment Review Committee (RARC)

Health Effects Division (7509P)

Donna Davis, Acting Chief

Risk Assessment Branch VI

Health Effects Division (7509P)

To: Driss Benmhend/Richard Gebken, PM10

Insecticide Branch 

Registration Division (7505P)
Cyflumetofen Human Health Risk Assessment DP No. D398246

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The Health Effects Division (HED) of the Office of Pesticide Programs (OPP) is charged with 

estimating the risk to human health from exposure to pesticides. BASF has requested 

registration of the new miticide cyflumetofen for foliar use on citrus fruit, grapes, pome fruit, 

strawberry, tomato, tree nuts, and ornamentals. The Registration Division (RD) of OPP has 

requested that HED evaluate hazard and exposure data and conduct dietary, residential, 

occupational, and aggregate exposure assessments, as needed, to estimate the risk to human 

health that will result from these proposed uses of cyflumetofen. 

HED has evaluated the toxicity and exposure databases for cyflumetofen and has conducted a 

human health risk assessment which is provided in this document. Based on this assessment, 

HED has determined that there are no potential risk estimates of concern for the proposed uses of 

cyflumetofen.

The HED team members contributing to this risk assessment include Donald Wilbur (residue 

chemistry, dietary exposure assessment, and risk assessment), Shalu Shelat (occupational and 

residential exposure assessments), and Yung Yang (hazard assessment). Stephen Wente of the 

Environmental Fate and Effects Division (EFED) performed the drinking water assessment.
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Table of Contents

1.0 Executive Summary............................................................................................................. 5

2.0 HED Recommendations....................................................................................................... 7

2.1 Data Deficiencies ............................................................................................................. 8

2.2 Tolerance Considerations................................................................................................. 8

2.2.1 Enforcement Analytical Method............................................................................... 8

2.2.2 Recommended Tolerances........................................................................................ 8

2.2.3 Revisions to Petitioned-For Tolerances.................................................................... 9

2.2.4 International Harmonization ..................................................................................... 9

2.3 Label Recommendations.................................................................................................... 10

3.0 Introduction........................................................................................................................ 10

3.1 Chemical Identity ........................................................................................................... 10

3.2 Physical/Chemical Characteristics................................................................................. 10

3.3 Pesticide Use Pattern...................................................................................................... 10

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)....................................... 14

4.4.1 Completeness of the Toxicology Database............................................................. 14

4.4.2 Evidence of Neurotoxicity ...................................................................................... 14

4.4.3 Evidence of Sensitivity/Susceptibility in the Developing or Young Animal ......... 14

4.4.4 Residual Uncertainty in the Exposure Database..................................................... 15

4.5 Toxicity Endpoint and Point of Departure Selections.................................................... 15

4.5.1 Dose-Response Assessment.................................................................................... 15

4.5.2 Recommendation for Combining Routes of Exposures for Risk Assessment........ 16

4.5.3 Cancer Classification and Risk Assessment Recommendation.............................. 17

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 Animal Metabolism Studies............................................... 20

5.1.2 Summary of Environmental Degradation ............................................................... 21

5.1.3 Comparison of Metabolic Pathways....................................................................... 22

5.1.4 Residues of Concern Summary and Rationale........................................................ 22

5.2 Food Residue Profile...................................................................................................... 24

5.3 Water Residue Profile .................................................................................................... 25

5.4 Dietary Risk Assessment................................................................................................ 25

5.4.1 Description of Residue Data Used in Dietary Assessment..................................... 26

5.4.2 Percent Crop Treated Used in Dietary Assessment ................................................ 26

5.4.3 Acute Dietary Risk Assessment.............................................................................. 26

5.4.4 Chronic Dietary Risk Assessment .......................................................................... 26

5.4.5 Cancer Dietary Risk Assessment............................................................................ 26
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5.4.6 Summary Table....................................................................................................... 27

6.0 Residential (Non-Occupational) Exposure/Risk Characterization .................................... 27

6.1 Residential Handler Exposure........................................................................................ 27

6.2 Post-Application Exposure............................................................................................. 28

6.3 Residential Risk Estimates for Use in Aggregate Assessment ...................................... 28

6.4 Residential Bystander Post-application Inhalation Exposure ........................................ 29

6.5 Spray Drift...................................................................................................................... 29

7.0 Aggregate Exposure/Risk Characterization....................................................................... 30

7.1 Acute Aggregate Risk .................................................................................................... 30

7.2 Short-Term Aggregate Risk ........................................................................................... 30

7.3 Chronic Aggregate Risk................................................................................................. 31

7.4 Cancer Aggregate Risk................................................................................................... 31

8.0 Cumulative Exposure/Risk Characterization..................................................................... 31

9.0 Occupational Exposure/Risk Characterization .................................................................. 32

9.1 Short-/Intermediate- Term Handler Risk ....................................................................... 32

9.2 Short-/Intermediate- Term Post-Application Risk ......................................................... 35

9.2.1 Dermal Post-application Risk ................................................................................. 35

9.2.2 Inhalation Post-application Risk............................................................................. 35

10.0 References.......................................................................................................................... 37

Appendix A. Toxicology Profile and Executive Summaries....................................................... 38

A.1 Toxicology Data Requirements...................................................................................... 38

A.2 Toxicity Profiles............................................................................................................. 39

A.3 Hazard Identification and Endpoint Selection ............................................................... 42

A.4 Executive Summaries..................................................................................................... 45

A.5 Summary of Toxicological Doses and Endpoints for Cyflumetofen ............................. 64

Appendix B. Metabolism Summary Table ................................................................................... 65

B.1 Structures of Cyflumetofen Metabolites........................................................................ 65

B.2 Tabular Summary of Metabolites and Degradates......................................................... 68

Appendix C. Physical/Chemical Properties................................................................................. 71

Appendix D. Review of Human Research................................................................................... 72

Appendix E. Residue Summary Table......................................................................................... 73
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1.0 Executive Summary

Cyflumetofen (2-methoxyethyl α-cyano-α-[4-(1,1-dimethylethyl)phenyl]-β-oxo-2-

(trifluoromethyl)benzenepropanoate) is a new active ingredient from BASF that belongs to the 

acrylonitrile class of chemicals with a novel insecticidal mode of action – mitochondria complex 

II electron transport inhibition. It is a selective contact miticide that is effective on all mite life 

stages. It is currently proposed only for foliar applications via ground or aerial equipment. 

Cyflumetofen is formulated as a 20% suspension concentrate (SC). BASF is proposing 

uses/tolerances on tree nuts (crop group 14-12), pome fruits (crop group 11-10), citrus (crop 

group 10-10), grapes, strawberries, tomatoes, and ornamentals. The present action was 

conducted as a joint review with Health Canada’s Pesticide Management Regulatory Authority 

(PMRA) and Mexico’s Federal Commission for the Protection against Sanitary Risk 

(COFEPRIS).

The toxicology database is considered complete for cyflumetofen. A subchronic inhalation study

was not available; however, the HASPOC determined that the requirement for this study is not 

needed at this time. The major target organ in rats, mice, and dogs following short-term and 

long-term oral administration of cyflumetofen is the adrenal glands characterized by increased 

organ weight and histopathology (vacuolation and hypertrophy of the adrenal cortical cells). 

Cyflumetofen has low acute toxicity by oral, dermal, and inhalation routes of exposure. It is 

minimally irritating to the eyes but not to the skin. It is a skin sensitizer. Decreased serum 

hormone concentrations (FSH, progesterone, and 17 β-estradiol) were observed in the mid- and 

high-dose F1 females in a rat reproduction study while no hormonal effect was observed in the F1

male rats at any dose level. However, there were no corresponding changes in reproductive 

performance at any dose level. In the developmental toxicity study in rats, an increased 

incidence of wavy ribs was noted at the high- dose (1000 mg/kg/day), while an increased 

incidence of incompletely ossified sternal centra was observed at the mid- and high-dose levels. 

These incidences occurred in the presence of maternal toxicity. In the developmental toxicity

study in rabbits, a downward flexion of the forepaws and/or hind paws was observed in the highdose (1000 mg/kg/day) group pups and delays in skeletal ossification were observed in pups at 

the mid- and high-doses. Maternal toxicity (adrenal effects) was also observed at the mid- and 

high- doses. No evidence of neurotoxicity or immunotoxicity was observed in any of the 

submitted studies for cyflumetofen.

No acute reference dose (aRfD) was established to assess acute dietary risks since there was no 

evidence of toxicity attributable to a single dose for the general U.S. population, infants and 

children, or females 13-49 years of age in any studies. For the chronic dietary risk assessment, a 

chronic reference dose (cRfD) of 0.17 mg/kg/day was established for assessments of all 

populations, with a no observed adverse effect level (NOAEL) of 16.5 mg/kg/day and a lowest 

observed adverse effect level (LOAEL) of 30.6 mg/kg/day based on effects on the adrenals 

(increased organ weight and histopathology), which is the target organ. Three rat studies (90-day

subchronic, chronic toxicity/carcinogenicity, and reproduction studies) were selected as cocritical studies for the chronic dietary endpoint. These studies are appropriate for the duration 

and populations of concern since there is no progression of toxicity over time. No dermal hazard 

was identified for cyflumetofen. For short- and intermediate-term inhalation exposure, the 
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NOAEL of 16.5 mg/kg/day with a LOAEL of 30.6 mg/kg/day based on effects on the adrenals 

was selected from the same co-critical studies chosen for the chronic reference dose. 

The risk assessments conducted for cyflumetofen were based on the most sensitive endpoints in 

the toxicity database, and the NOAELs selected for risk assessment are considered protective of 

potential developmental, neurotoxic, and immunotoxic effects for infants and children. There is 

no evidence of increased qualitative or quantitative susceptibility in the rat 2-generation 

reproduction study; however, the rat and rabbit developmental studies indicate susceptibility in 

the pups. There is evidence of increased quantitative susceptibility in the rabbit developmental 

toxicity study, since developmental effects at the limit dose were observed where no maternal 

toxicity was present. There is evidence of increased qualitative susceptibility in the rat 

developmental toxicity study as developmental effects were seen at the same dose that caused an 

increase in adrenal weights and organ-to-body weight ratio in the maternal animals. 

Notwithstanding, the degree of concern for these effects in infants and children is low because 

the rat and rabbit developmental effects have clearly defined NOAEL/LOAELs and the dose 

selected for chronic risk assessment is protective of these effects. There is no evidence of 

neurotoxicity in any of the submitted studies for cyflumetofen. Further, highly conservative 

exposure estimates were incorporated into the risk assessment; therefore, reduction of the 10X 

FQPA safety factor to 1X is considered appropriate.

Cyflumetofen has been classified as having “Suggestive Evidence of Carcinogenic Potential” in 

accordance with the EPA's Final Guidelines for Carcinogen Risk Assessment (March, 2005).

This classification is based on the presence of a single tumor type (thyroid c-cell) in one sex 

(male) and one species (rat), and the lack of concern for mutagenicity. When there is suggestive 

evidence of carcinogenicity, the Agency does not attempt a dose-response assessment as the 

nature of the data generally would not support one. Therefore, the Agency has determined that 

quantification of risk using a non-linear approach (i.e. the chronic reference dose) will 

adequately protect for all chronic toxicity, including carcinogenicity, likely to result from 

exposure to cyflumetofen. 

The residue chemistry database is considered complete for cyflumetofen for the purposes of this 

petition. The nature and magnitude of the residue in plants has been adequately delineated. The 

residue of concern in plants is the parent compound only. No cyflumetofen residues are 

expected in livestock commodities based on the submitted ruminant metabolism study and the 

calculated dietary burden. Adequate storage stability, method validation data and processing 

studies have been submitted. An adequate LC/MS/MS (liquid chromatography/tandem mass 

spectrometry) analytical method is available to enforce the proposed tolerances. As part of the 

joint review process, harmonization of recommended tolerance levels was achieved. 

Environmentally, the cyflumetofen molecule has very low water solubility and is expected to 

degrade quickly through multiple fate processes (with half-lives of hours to several days) under 

environmental conditions. As this is a new active ingredient, there are no monitoring data 

available, thus drinking water concentrations were estimated using models. 

An acute reference dose was not selected for cyflumetofen; therefore, the Agency conducted 

only a chronic dietary (food and drinking water) exposure and risk assessment. This assessment

was conducted using tolerance level residues, empirical processing factors where available, 
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100% crop treated and modeled surface water exposure estimates. Using assumptions 

considered to be highly conservative, the chronic dietary risk estimates are below HED’s level of 

concern (<100% of the chronic population adjusted dose (cPAD)), and range from <1% of the 

cPAD for the general U.S. population to 2.3% of the cPAD for the highest exposed population 

subgroup of children 1-2 years old.

The proposed uses of cyflumetofen on ornamentals may result in adult residential handler and 

post-application exposure. This exposure is expected to be only short-term in duration (i.e., 1 to 

30 days) as intermediate- or long-term exposures are not likely based on the intermittent nature 

of applications by homeowners. Since no dermal hazard was identified for cyflumetofen in the 

toxicological database, only inhalation exposure assessments were conducted. These 

assessments were conducted according to HED’s 2012 Residential Standard Operating 

Procedures (SOPs) and the resulting inhalation margins of exposure (MOEs) for all scenarios are 

not of concern since they are above the level of concern (LOC) of 100 (MOEs ≥ 100).

Since there are no acute points of departure identified, an acute aggregate risk assessment was 

not conducted. HED has conducted short-term and long-term (chronic) aggregate risk 

assessments for cyflumetofen. Short-term aggregate MOEs are above the LOC of 100 and are 

not of concern (MOEs ≥ 100). The long-term (chronic) aggregate assessment includes only

dietary (food and water) exposure as long-term residential exposure is not expected. Chronic 

dietary risk is not of concern. 

No dermal hazard has been identified for cyflumetofen; therefore occupational handler and postapplication risks were assessed for the inhalation route of exposure only. All estimated shortand intermediate-term handler inhalation risk estimates are above the Agency’s level of concern

(MOEs ≥ 100). Based on the Agency's current practices, a quantitative post-application 

inhalation exposure assessment was not performed for cyflumetofen.

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 data, which include the Pesticide 

Handlers Exposure Database Version 1.1 (PHED 1.1); the Agricultural Handler Exposure Task 

Force (AHETF) database; the Outdoor Residential Exposure Task Force (ORETF) database; the 

Agricultural Re-entry Task Force (ARTF) database; and the Residential SOPs (Residential 

Handler) are subject to ethics review pursuant to 40 CFR 26, have received that review, and are 

compliant with applicable ethics requirements. For certain studies that review may have 

included review by the Human Studies Review Board.

2.0 HED Recommendations

Provided a revised Section F to amend the proposed tolerances is submitted as noted in Section 

2.2 below, there are no hazard, exposure, or risk considerations that would preclude granting the 

requested uses of cyflumetofen or establishing the tolerances required to support those uses. 
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2.1 Data Deficiencies

There are no data deficiencies relating to toxicology, residue chemistry, or 

occupational/residential exposure assessment associated with this action. 

2.2 Tolerance Considerations

2.2.1 Enforcement Analytical Method

An adequate analytical method is available to enforce the HED recommended tolerances for 

cyflumetofen in plant commodities. The high-performance liquid chromatography with tandem 

mass spectrometry (HPLC-MS/MS) method, BASF D1003, has been adequately validated, has 

undergone a successful ILV (independent laboratory validation), is considered adequately radiovalidated and has been reviewed by the Agency for appropriateness as an enforcement method. 

BASF method D1003 has a limit of quantitation (LOQ) of 0.01 ppm for residues of cyflumetofen 

in all matrix types. The method limit of detection (LOD) for residues of cyflumetofen in all 

matrices, except orange oil, has been set at 0.002 ppm, or approximately 20% of the LOQ. 

Orange oil has an LOD of 0.0035 ppm.

BASF method D1003 is described briefly as follows. Residues of cyflumetofen are extracted 

from crop matrices by shaking with acetonitrile followed by acetonitrile-water (hexane is also 

added for extractions from oil). An aliquot of the extract is concentrated to remove the 

acetonitrile (the hexane phase is also removed from oil extractions) and acidified with formic 

acid. The residues are then partitioned with a mixture of ethyl acetate-cyclohexane. An aliquot 

of the organic phase is concentrated in the presence of 0.1% formic acid in water, and redissolved in 0.1% formic acid in acetonitrile for HPLC-MS/MS determination.

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

multi-residue method (MRM) protocols. Cyflumetofen is not adequately recovered through any 

of the FDA multi-residue protocols. 

2.2.2 Recommended Tolerances

HED recommends that 40 CFR be amended by establishing tolerances for residues of 

cyflumetofen in plant commodities as listed in Table 2.2.2. For the purposes of this petition, 

tolerances for residues of cyflumetofen were derived using the Organization for Economic 

Cooperation and Development Maximum Residue Level (OECD MRL) Calculation Procedures. 

Based on the HED Interim Guidance on Tolerance Expressions (S. Knizner, 05/27/2009), the 

following tolerance expression is recommended.

Tolerances are established for residues of the insecticide cyflumetofen, including its 

metabolites and degradates, in or on the commodities in the table below. Compliance 

with the tolerance levels for cyflumetofen is to be determined by measuring only

cyflumetofen, 2-methoxyethyl α-cyano-α-[4-(1,1-dimethylethyl)phenyl]-β-oxo-2-

(trifluoromethyl)benzenepropanoate, in or on the commodity. 
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Table 2.2.2. Tolerance Summary for Cyflumetofen

Commodity Proposed 

Tolerance 

(ppm)

HED-Recommended 

Tolerance (ppm)

Comments 

Almond, hulls 4.0 4.0

Citrus, oil 16.0 16

Fruit, citrus, group 10-10 0.3 0.30

Fruit, pome, group 11-10 0.3 0.30

Grape 0.6 0.60

Grape, raisin 0.9 N/A Not required, raisin is covered by 

RAC grape tolerance

Nut, tree, group 14-12 0.01 0.01

Strawberry 0.6 0.60

Tomato 0.2 0.40

2.2.3 Revisions to Petitioned-For Tolerances

HED is recommending that tolerances be set for the commodities requested by the registrant at 

the levels requested, with the changes noted below. Additionally, minor modifications to some 

commodity definitions are recommended. The petitioner had requested tolerances on Fruit, 

citrus, group 10; Fruit, pome, group 11; and Nut, tree, group 14. To be consistent with updated 

Agency naming-conventions for crop groups, these have been changed to Fruit, citrus, group 10-

10; Fruit, pome, group 11-10; and Nut, tree, group 14-12. The requested changes to tolerance 

levels are shown above in Table 2.2.2.

The proposed tolerance level of 0.2 ppm for tomato should be increased to 0.40 ppm to fully

account for residue loss from the field trial samples during freezer storage from the time of 

harvest to the time of analysis. The proposed tolerance for grape, raisin of 0.9 ppm is not 

required since the tolerance for the raw agricultural commodity grape at 0.60 ppm is adequate to 

account for any residue concentration shown in the processed commodity.

2.2.4 International Harmonization

The present action was conducted as a joint review with Health Canada’s Pesticide Management 

Regulatory Authority (PMRA) and Mexico’s Federal Commission for the Protection against 

Sanitary Risk (COFEPRIS). Harmonization of tolerance expression and levels for plant 

commodities was achieved during the review process. Based on the submitted ruminant 

metabolism data and the limited livestock feedstuffs associated with this petition, HED 

concludes the proposed uses can be classified as 40 CFR 180.6 (a)(3), no reasonable expectation 

of finite residues in ruminant livestock commodities; therefore, the U.S. will not need to set 

tolerances for ruminant livestock commodities. However, since PMRA is not legally able to 

waive the requirement for a tolerance based on no reasonable expectation of finite residues, 

tolerances at the LOQ of the enforcement analytical method will be established in Canada for 

ruminant livestock commodities. No Codex MRLs have been established for cyflumetofen.
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2.3 Label Recommendations

There are no label recommendations relating to toxicology, residue chemistry, or 

occupational/residential exposure assessment associated with this action. 

3.0 Introduction

3.1 Chemical Identity

Table 3.1. Cyflumetofen Nomenclature

Compound Chemical Structure

Common name Cyflumetofen

Company experimental name BAS 9210 I, OK 5101

IUPAC name 2-methoxyethyl (RS)-2-(4-tert-butylphenyl)-2-cyano-3-oxo-3-(α , α ,α -trifluoroo-tolyl) propionate

CAS name 2-methoxyethyl α-cyano-α-[4-(1,1-dimethylethyl)phenyl]-β-oxo-2-

(trifluoromethyl)benzenepropanoate

CAS # 400882-07-7

End-use product/EP Nealta TM , Sultan TM

3.2 Physical/Chemical Characteristics

Cyflumetofen has low water solubility. Its octanol/water partition coefficient suggests that it is a 

hydrophobic compound that is more fat soluble than water soluble, exhibiting a tendency to 

dissolve in fats, oils, lipids, and non-polar solvents more readily than in water. Further, 

cyflumetofen has a low vapor pressure. The physiochemical properties for this active ingredient 

are shown in Appendix C, Table C.1.

3.3 Pesticide Use Pattern

Cyflumetofen end-use products NealtaTM and SultanTM are both formulated as a 20% suspension 

concentrate (SC). Two applications may be made per season at a maximum single application 

rate of 0.2 lbs ai/acre with retreatment intervals of 14 to 21 days as stated on the proposed 

product labels. The maximum seasonal application rate is 0.4 lbs ai/A/season for all use sites. 

Applications may be made using open-cab ground-boom sprayers, airblast sprayers, and aerial 

equipment for the proposed occupational uses, while handheld equipment is allowed for both 

occupational and as well as residential uses. Aerial application is allowed only on tomatoes. 

Chemigation is prohibited on all proposed use sites. The proposed preharvest interval (PHI) 

ranges from 1 to 14 days depending on the use.
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Table 3.3. Summary of Directions for Use of Cyflumetofen

Proposed 

Use

Application 

Equipment

Formulation 

[EPA Reg. 

No.]

Applic. 

Rate (lb 

ai/A)

Max. No. 

Applic. per 

Season

Max. 

Seasonal 

Applic. Rate 

(lb ai/A)

PHI 

(days)

Use Directions and 

Limitations

Citrus Fruit

Airblast, 

Groundboom Nealta 

[EPA Reg. No.

7969-GGA]

0.2 2 0.4

7 Do not apply by air to 

citrus fruit, pome fruit, 

strawberries, or tree nuts. 

Aerial only allowed on 

tomatoes. Do not apply 

through an irrigation 

system.

Retreatment interval: 14 

days

Grapes 14

Pome Fruit 7

Tree Nut 

Group 7

Strawberry Groundboom 1

Tomato Groundboom, 

Aerial 3

Ornamentals

Groundboom 

and handheld 

equipment

Sultan 

[EPA Reg. No.

7969-GGT]

0.2

(0.002

lbs 

ai/gallon)

2 0.4 n/s

DO NOT apply by 

chemigation or air. DO 

NOT use on vegetables 

grown in greenhouses for 

crop production or in 

vegetable production of 

transplant for outdoor use.

Retreatment interval: 14-

21 days

3.4 Anticipated Exposure Pathways

The Registration Division has requested an assessment of human health risk to support the 

proposed new uses of cyflumetofen on citrus fruit, grapes, pome fruit, strawberry, tomato, tree 

nuts, and ornamentals. Humans may be exposed to cyflumetofen in food and drinking water, 

since cyflumetofen may be applied directly to growing crops and application may result in 

cyflumetofen reaching surface and ground water sources of drinking water. Cyflumetofen is 

being proposed for use on ornamentals (i.e., residential landscape areas) and may be applied in 

residential settings; therefore there is a potential for exposure in residential or non-occupational 

settings. In an occupational setting, applicators may be exposed while handling the pesticide 

prior to application, as well as during application. There is also a potential for post-application 

exposure for workers re-entering treated fields. 

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 Populations," 

(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-established 

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 consumption patterns are compiled by the U.S. Department of 
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Agriculture’s (USDA’s) 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 able 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 risks 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 subgroups.

4.0 Hazard Characterization and Dose-Response Assessment

4.1 Toxicology Studies Available for Analysis

The toxicology database is complete and the toxicity profile can be characterized for a wide 

range of effects, including potential developmental, reproductive, neurotoxic, mutagenic, 

carcinogenic, and immunotoxic effects. The HASPOC determined that a subchronic inhalation 

study is not needed for cyflumetofen (TXR# 0056691, July 3, 2013) based on a weight of 

evidence (WOE) approach that considered all of the available hazard and exposure information 

for cyflumetofen, including: 1) the physical/chemical properties of cyflumetofen including its 

low volatility (4.43 x 10-8 mm Hg at 25 oC); (2) its low acute inhalation toxicity (Toxicity

Category IV); and (3) the use of an oral POD results in MOEs that are ≥5,500, and above the 

Agency’s level of concern. The available toxicity studies for cyflumetofen are listed in Table 

A.1 in Appendix A. 

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

There were a series of metabolism studies conducted for cyflumetofen. Detailed information is 

provided in the Appendix A.4.8. 

14C-cyflumetofen was rapidly absorbed following 

administration of the low dose, with plasma levels of radioactivity peaking at 1 hour post-dosing. 

Absorption was slightly slower following administration of the high dose, with peak plasma 

levels attained at 2-4 hours post-dosing indicating saturation of absorption. At the high dose, 

females demonstrated higher Cmax and area under the curve (AUC) values than males. 

At 72 hours post-dosing, the gastrointestinal tract, carcass, liver and kidney contained the highest 

proportions of radioactivity. Most of the radioactivity excreted in urine from low dose rats (90-

96%) was eliminated within 24 hours after dosing, whereas at the high dose, excretion was 

slower with only 74-88% eliminated within 24 hours of dosing. At both low and high doses, 60-

89% of the radioactivity excreted in feces was eliminated within 24 hours of dosing.

The unchanged parent was not detected in the urine of any test group. Metabolite AB-3 was 

identified as a major metabolite in the urine of female rats but was a minor urinary metabolite in 

males. Metabolite AB-2 was a minor metabolite in urine of all test groups except females from 

the low dose group, in which residues for this metabolite reached 4% of the administered dose. 
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The major metabolites detected in the bile from all test groups were the glucuronic acid 

conjugates of metabolites AB-1 and AB-3. Metabolite AB-2 was also detected at lower levels in

the bile from all test groups. Unique metabolites identified in the bile of rats administered the Aring or B-ring label included the glucuronic acid conjugate of A-6 and the glutathione conjugate 

of B-1, respectively.

14C-cyflumetofen was metabolized in the rat primarily by hydrolytic cleavage of the 

trifluoromethylbenzoyl moiety resulting in metabolite B-1 (trifluoromethylbenzoic acid) and A18. Another minor pathway included successive hydroxylation of the tert-butyl side chain.

4.2.1 Dermal Absorption

A dermal absorption study was submitted which supports an estimated dermal absorption of 

11%. However, since no dermal hazard has been identified for cyflumetofen, no dermal 

endpoint was selected for use in risk assessment. 

4.3 Toxicological Effects

The major target organ in rats, mice, and dogs following short-term and long-term oral exposure 

is the adrenal glands characterized with increased organ weight and histopathology (vacuolation 

and hypertrophy of the adrenal cortical cells). The adrenal effects are the most sensitive and 

protective endpoint for all lifestages and populations of concern since there is no progression of 

toxicity over time.

Cyflumetofen has low acute toxicity by oral, dermal, and inhalation routes of exposure. It is 

minimally irritating to the eyes but not to the skin. It is a skin sensitizer. There is no evidence of 

neurotoxicity or immunotoxicity in any of the submitted studies for cyflumetofen. In the 

developmental toxicity study in rats, an increased incidence of wavy ribs was noted at the high 

dose (1000 mg/kg/day), while an increased incidence of incompletely ossified sternal centra was 

observed at the mid- and high-dose levels. These incidences occurred in the presence of maternal 

toxicity. In the developmental toxicity study in rabbits, delays in skeletal ossification were 

observed at the mid- and high-doses where the maternal toxicity was observed. The only adverse 

external alteration observed was a downward flexion of the forepaws (2 fetuses from one litter) 

or hind paws (1 fetus from one litter) in the high-dose (1000 mg/kg/day) group with observed 

maternal toxicity. The incidences were slightly above historical controls and were considered a 

treatment-related adverse effect.

In the rat reproduction study, adrenal effects (increased weight and histopathology) were 

observed in the parental and offspring animals at the mid- and high-doses. Serum hormone 

concentrations were measured in the F1 parental rats. The FSH, progesterone, and 17 β-estradiol 

levels in the mid- and high-dose female groups were significantly lower than the corresponding 

values in the control groups. No hormonal effect was observed in the F1 male rats at any dose 

level. Overall reproductive performance showed that there were no corresponding changes in 

reproductive performance at any dose level.

In accordance with the EPA's Final Guidelines for Carcinogen Risk Assessment (March, 2005), 

the Cancer Assessment Review Committee (CARC) classified cyflumetofen as “Suggestive 
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Evidence of Carcinogenic Potential”. This classification is based on the presence of a single 

tumor type (thyroid c-cell) in one sex (male) and one species (rat), and the lack of concern for 

mutagenicity. When there is suggestive evidence of carcinogenicity, the Agency does not attempt 

a dose-response assessment as the nature of the data generally would not support one. Therefore, 

the Agency has determined that quantification of risk using a non-linear approach (i.e. the 

chronic reference dose) will adequately protect for all chronic toxicity, including carcinogenicity, 

likely to result from exposure to cyflumetofen. 

4.4 Safety Factor for Infants and Children (FQPA Safety Factor)

HED recommends that the 10X FQPA Safety Factor (for the protection of infants and children) 

be reduced to 1X. An FQPA Safety Factor of 1X is appropriate for the following reasons:

The toxicity database is complete and adequate to assess safety for infants and children. There is 

no evidence of increased qualitative or quantitative susceptibility in the rat 2-generation 

reproduction study. While there is evidence of increased susceptibility in the rabbit and rat 

developmental studies, these studies have clearly defined NOAEL/LOAELs. There is no 

evidence of neurotoxicity in the acute and subchronic neurotoxicity studies for cyflumetofen, and 

a developmental neurotoxicity study is not required. Based on the use of conservative 

assumptions with respect to potential exposure from food, water and residential uses, the 

assessment will not underestimate children’s exposure to cyflumetofen. Further details may be 

found in the following sections.

4.4.1 Completeness of the Toxicology Database

The database is complete and adequate to characterize potential pre- and/or post-natal risk for 

infants and children. 

4.4.2 Evidence of Neurotoxicity

There are acute and subchronic neurotoxicity studies available. No evidence of neurotoxicity

was observed in any of the submitted studies for cyflumetofen. A developmental neurotoxicity

study is not required.

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

There is no evidence of increased qualitative or quantitative susceptibility in the rat 2-generation 

reproduction study; however, the rat and rabbit developmental studies indicate susceptibility in 

the pups. There is evidence of increased quantitative susceptibility in the rabbit developmental 

toxicity study, since developmental effects (changes in ossicification, paw flexion, and decreased 

fetal body weights) at the limit dose were observed where no maternal toxicity was present. 

There is evidence of increased qualitative susceptibility in the rat developmental toxicity study as 

developmental effects (increased incidence of incompletely ossified sternal centra) were seen at 

the same dose that caused an increase in adrenal weights and organ-to-body weight ratio in the 

maternal animals. Notwithstanding, the degree of concern for these effects in infants and 

children is low because the rat and rabbit developmental effects have clearly defined 
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NOAEL/LOAELs and the dose selected for chronic risk assessment is protective of these effects. 

Therefore, the PODs based on adrenal effects in rat are health protective of all lifestages.

4.4.4 Residual Uncertainty in the Exposure Database

There are no residual uncertainties in the exposure database. Since the dietary and residential 

exposure estimates were based on conservative assumptions, HED is confident that this 

assessment does not underestimate dietary (food and water) or residential exposure. 

The chronic dietary exposure assessment used tolerance level residues for all commodities, 

100% crop treated (% CT), and empirical processing estimates when available or DEEMTM 

default processing factors. The drinking water assessment utilized water concentration values 

generated by models and associated modeling parameters which are designed to produce 

conservative, health protective, high-end estimates of water concentrations which are not likely 

to be exceeded. For these reasons it can be concluded that the chronic dietary exposure analysis 

does not underestimate risk from chronic exposure to cyflumetofen.

Similarly, HED does not believe that the residential exposure estimates are underestimated 

because they are also based on conservative assumptions including maximum application rates 

and standard values for unit exposures, acreage treated/amount handled. 

4.5 Toxicity Endpoint and Point of Departure Selections

4.5.1 Dose-Response Assessment

The detailed description of the toxicity studies used for selecting toxicity endpoints and points of 

departure for various exposure scenarios are presented in Appendix A.3.

No appropriate endpoint attributable to a single exposure (dose) was identified from studies 

including an acute neurotoxicity study and developmental toxicity studies in rats and rabbits. An 

acute RfD was not established for the general population including infants, children, and females 

age 13-49. In the developmental toxicity study in rabbits, increased incidence of paw flexion 

was observed at 1000 mg/kg/day and was slightly above historical controls. Maternal toxicity, 

decreased fetal body weight, and incomplete ossification were also observed at this dose. Paw 

flexion was considered to be associated with ossification effects (i.e., all three pups that 

exhibited paw flexions also had incomplete ossification). Delays in ossification and 

developmental delays are not typically considered to occur as a result of exposure to a single 

dose and therefore are not appropriate as endpoints for acute risk assessment. 

For the chronic dietary, three studies were selected as co-critical studies for endpoint selection. 

These studies are appropriate for the duration and populations of concern since there is no 

progression of toxicity over time. The NOAEL and LOAEL selected were based on the weight of 

evidence from the three studies which had similar target organ toxicities. The point of departure 

of 16.5 mg/kg/day (NOAEL) was selected from the 90-day and the chronic toxicity/

carcinogenicity rat studies, which have similar NOAELs and LOAELs based on effects on the 

adrenals. In the 2-generation reproduction study, a lower NOAEL of 9.2 mg/kg/day was 
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identified with a LOAEL of 30.6 mg/kg/day based on effects on the adrenals; however, this 

NOAEL of 9.2 mg/kg/day was not selected as the POD for risk assessment since it is considered 

to be a function of calculated compound intake (based on food consumption) rather than a lower 

NOAEL/LOAEL per se. The POD of 16.5 mg/kg/day selected is still protective of similar 

effects seen at 30.6 mg/kg/day in the 2-generation reproduction toxicity study, the 28 day rat 

study at LOAEL of 75 mg/kg/day, the chronic mouse study at LOAEL of 537/483 mg/kg/day

(M/F), and the chronic dog study at LOAEL of 300 mg/kg/day.

There is no incidental oral exposure expected based on the current use pattern; however, an 

endpoint was selected during the full review of the database. Similar to the chronic endpoint 

selection, three studies were selected as co-critical studies for short- and intermediate-term 

incidental oral exposure. These studies are appropriate for the duration since there is no 

progression of toxicity over time. The point of departure of 16.5 mg/kg/day (NOAEL) was 

selected from the 90-day and the chronic toxicity/carcinogenicity rat studies. The LOAEL of 

30.6 mg/kg/day was selected based on effects on the adrenals from the 2-generation reproduction 

study.

For short- and intermediate-term dermal exposure, no appropriate endpoint was identified for 

risk assessment. A 28-day dermal toxicity study in rats is available; however, no adverse effects 

were seen at the highest dose tested of 1000 mg/kg/day, including the endpoints of concern 

(adrenal effects). Although developmental/reproductive effects (not assessed in the dermal 

study) were observed in the developmental and reproductive toxicity studies, the effects occurred 

at dermal equivalent doses above the limit dose or in the presence of parental toxicity. 

Therefore, since no effects were observed in adults at the limit dose, no developmental or 

reproductive effects would be expected to occur due to parental dermal exposure. 

A route-specific subchronic inhalation toxicity study is not available for cyflumetofen. For 

short-and intermediate-term inhalation risk assessments, an oral NOAEL was selected from three 

studies as described in the chronic dietary. These studies are appropriate for the duration since 

there is no progression of toxicity over time. The point of departure of 16.5 mg/kg/day (NOAEL) 

was selected from the 90-day and the chronic toxicity/carcinogenicity rat studies, which have 

similar NOAELs and LOAELs. The LOAEL of 30.6 mg/kg/day was selected from the 2-

generation reproduction study. Since an oral study was selected, absorption via inhalation is 

presumed to be equivalent to oral absorption. There is no proposed long-term use; therefore, 

risk assessment for long-term inhalation exposure is not required.

A 100X uncertainty factor is applied (interspecies factor of 10X and intraspecies factor of 10X) 

for chronic dietary risk assessments. For inhalation risk assessment, the level of concern (LOC) 

is a margin of exposure (MOE) of 100, based on the combined interspecies (10X) and 

intraspecies (10X) uncertainty factors. 

4.5.2 Recommendation for Combining Routes of Exposures for Risk Assessment

When there are potential occupational and residential exposures to a pesticide, the risk 

assessment must address exposures from three major sources (oral, dermal, and inhalation) and 

then determine whether the individual exposures can be combined if they have the same 
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toxicological effects. Since no dermal hazard has been identified for cyflumetofen, a dermal 

assessment was not conducted. However, inhalation and oral routes can be combined since the 

points of departure are based on the same studies and the toxicological effects are the same.

4.5.3 Cancer Classification and Risk Assessment Recommendation

The carcinogenic potential of cyflumetofen was evaluated following dietary administration to 

male and female Fischer 344 rats and male and female CD-1 mice. Two separate studies were 

conducted in both species. In 2004, the Registrant conducted a carcinogenicity study in Fischer 

344 rats and a carcinogenicity study in CD-1 mice. Since there was no evidence of 

carcinogenicity in either species, and to address concern regarding the adequacy of the doses 

tested in the above studies, the Registrant elected to conduct supplemental studies to evaluate 

higher doses in mice and rats.

Cyflumetofen was administered in the diet to groups of 50 rats/sex/dose for 104 weeks. One 

study was conducted at doses of 0, 150, 500 and 1500 ppm (0, 4.9, 16.5, and 49.5 mg/kg/day in 

males and 6.14, 20.3, and 61.9 mg/kg/day in females) while a second high dose study was 

conducted at 0 and 6000 ppm (0 and 220 mg/kg/day in males and 0 and 287 mg/kg/day in 

females). There was limited evidence of carcinogenicity characterized by the presence of thyroid 

c-cell tumors and interstitial cell tumors of the testes in male rats only at the highest dose tested 

(HDT). There was no evidence of carcinogenicity in female rats at any dose level. The doses 

tested in the rat study were considered to be adequate to assess the carcinogenic potential of 

cyflumetofen.

The thyroid c-cell tumors were determined to be treatment-related based on the following 

considerations: a statistically significant trend and a pair-wise significance (both at p < 0.05) for 

thyroid c-cell adenocarcinomas when compared to controls; a statistically significant trend (p < 

0.05) and a pair-wise significance (p<0.01) for thyroid c-cell adenomas and/or adenocarcinomas

combined; and the incidences of the adenocarcinomas (31%) and the combined tumors (57%) 

exceeded the historical control range from the testing laboratory (c-cell adenocarcinoma, 6-18%, 

and combined c-cell adenoma/carcinomas, 26-50%). 

The testicular interstitial cell tumors, although exacerbated by treatment were not considered to 

be biologically relevant since this tumor (Leydig cell, LCT) is extremely common in the F344 

rat, with a reported background incidence of 56-100% in 2-year cancer studies. The reasons for 

the different background incidence rate for LCT among species stem from both quantitative and 

qualitative differences in the Leydig cell response to hormonal stimuli. The rat Leydig cell is 

extremely sensitive to slight changes in circulating luteinizing hormone (LH) levels. Among rat 

strains, the F344 rat is particularly susceptible to this process and is not considered a relevant 

model for studying LCT. By contrast, the incidence rate in humans of LCT is very low (i.e., 

0.00004%). Similarly, rats are known to have approximately 13-times more LH receptors per cell 

than humans (Hutaniemi, 1983). Because of the differences present between the human and the 

rat Leydig cells, non-genotoxic compounds that cause LCTs in rats have little relevance to 

humans. The data with cyflumetofen supports this species and strain-specific effect on the 

Leydig cells.
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Additionally, the carcinogenic potential of cyflumetofen was evaluated following dietary

administration to male and female CD-1 mice. Two studies were conducted in the mice. 

Cyflumetofen was administered to groups of 52 mice/sex/dose for 78 weeks. One study was 

conducted at doses of 0, 150, 500, 1500 and 5000 ppm (0, 15.5, 54.3, 156 and 537mg/kg/day in 

males and 14.3, 48.1, 144 and 483 mg/kg/day in females) while a second high dose study was 

conducted at 0 and 10,000 ppm (0 and 1143 mg/kg/day in males and 1132 mg/kg/day in females. 

There was no evidence of carcinogenicity in male or female mice at any dose level. The doses 

tested in the mouse were considered adequate to assess the carcinogenic potential of 

cyflumetofen.

The mutagenic potential of cyflumetofen, its metabolites, and an impurity was tested in in vitro

and in vivo studies. There was no concern for mutagenicity for the parent, the metabolites or the 

impurity. Consequently, mutagenicity can be ruled out as a possible mode of action for tumor 

formation. 

In accordance with the EPA's Final Guidelines for Carcinogen Risk Assessment (March, 2005), 

the Cancer Assessment Review Committee (CARC) classified cyflumetofen as “Suggestive 

Evidence of Carcinogenic Potential”. This classification is based on the presence of a single 

tumor type (thyroid c-cell) in one sex (male) and one species (rat), and the lack of concern for 

mutagenicity. When there is suggestive evidence of carcinogenicity, the Agency does not attempt 

a dose-response assessment as the nature of the data generally would not support one. Therefore, 

the Agency has determined that quantification of risk using a non-linear approach (i.e. the 

chronic reference dose) will adequately protect for all chronic toxicity, including carcinogenicity, 

likely to result from exposure to cyflumetofen (TXR# 0056862). 

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

Assessment

Table 4.5.4. Summary of Toxicological Doses and Endpoints for Cyflumetofen for Use in Dietary, NonOccupational and Occupational 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)

An acute reference dose has not been established for either the general population or for Females 

13-49 years of age since there were no appropriate studies that demonstrated evidence of toxicity 

attributable to a single dose for these populations. 
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Table 4.5.4. Summary of Toxicological Doses and Endpoints for Cyflumetofen for Use in Dietary, NonOccupational and Occupational 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

Chronic 

Dietary (All 

Populations) NOAEL =

16.5 

mg/kg/day

UFA= 10x

UFH= 10x

FQPA SF= 1x

Chronic RfD = 

0.17 mg/kg/day

cPAD = 0.17

mg/kg/day

Three co-critical studies:

90-day feeding study in rats

LOAEL = 1000 ppm (54.5/62.8 

mg/kg/day in M/F) based on hematology 

and organ weight changes in the liver, 

adrenal, kidney and ovaries; and 

histopathology effects in the adrenals and 

the ovaries. NOAEL=300 ppm (16.5/19 

mg/kg/day in males/females)

Chronic toxicity/carcinogenicity study in 

rats

LOAEL = 1500 ppm (49.5/61.9 

mg/kg/day in M/F) based on increased 

adrenal weights and histopathology. 

NOAEL=500 ppm (16.5/20.3 mg/kg/day 

in males/females)

Two generation reproduction study in rats

Parental: LOAEL = 500 ppm (30.6/46.6 

mg/kg/day in M/F) based on increased 

organ weight and histopathology in 

adrenals. NOAEL=150 ppm (9.2/13.8 

mg/kg/day in males/females)

Dermal 

(Short-, 

Intermediateand LongTerm) 

No dermal hazard was identified. No appropriate endpoint was selected for risk assessment. 

Inhalation 

(Short-, 

Intermediateand LongTerm) 

NOAEL =

16.5 

mg/kg/day

UFA= 10x

UFH= 10x

FQPA SF= 1x

Occupational 

and Residential 

LOC for MOE = 

100

Same as chronic dietary endpoint

Cancer (oral, 

dermal, 

inhalation)

CARC Classification: Suggestive Evidence of Carcinogenic Potential.

* The complete summary of toxicological doses and endpoints for cyflumetofen can be found in Appendix A.5. 

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. UFA = 

extrapolation from animal to human (interspecies). UFH = potential variation in sensitivity 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. N/A = not applicable.
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5.0 Dietary Exposure and Risk Assessment 

5.1 Metabolite/Degradate Residue Profile

A tabular summary of the major metabolites and degradates for cyflumetofen are shown in 

Appendix B, Tables B.1 and B.2.

5.1.1 Summary of Plant and Animal Metabolism Studies

Plants

Metabolism studies on fruit crops (mandarin, apple, and eggplant) were submitted/reviewed and 

found to be scientifically acceptable. The studies were conducted with a single foliar application 

of 14C-cyflumetofen, either labeled on the butylphenyl ring (label A) or the benzoyl ring (label 

B) at a rate of 600 g ai/ha (~1.5x the maximum seasonal label application rate of 0.4 lbs ai/acre). 

The metabolism was seen to be limited in the three studies. The major part of the total 

radioactive residue (TRR) remained on the surface of fruits and leaves (56% to 97% TRR) and 

was easily removed by solvent rinses. The parent cyflumetofen was identified as the major 

component, accounting for 67% to 87% TRR on fruits and leaves 7 days after application, and 

44% to 81% TRR after 30 days. Degradation compounds were recovered at a level lower than 

10% TRR, except for the metabolite B-1 (2-trifluoromethylbenzoic acid) resulting from the 

cleavage of the parent molecule and representing up to 11% TRR in mandarin (0.06 ppm) and 

15% TRR in eggplant (0.06 ppm). In addition B-1 conjugates (metabolites U1 and U2) were 

detected up to 16% TRR in eggplant fruits at a PHI of 14 days. 

The nature of the residue for cyflumetofen in the proposed crops is considered to be adequately

understood. Metabolism in these three crops shared a common metabolic pathway with 

cyflumetofen as the primary component. However, in the absence of data on small grains, leafy

vegetables, and root/tuber crops, this data set is not considered adequate to define the nature of 

the residue in all plants. Therefore, if new uses on small grains, leafy vegetables, bulb 

vegetables, head/stem brassica, oilseeds, and/or root/tuber crops are proposed in the future, then 

additional metabolism studies may be required to reconsider the residues of concern in plants. 

The available metabolism data are only considered adequate to support uses on fruits, cucurbit 

vegetables, and fruiting vegetables.

Rotational Crops

Confined rotational crop data were submitted, reviewed and found to be scientifically acceptable. 

Cyflumetofen was applied to bare sandy loam soil in plastic containers at an application rate of 1 

x 400 g ai/ha (approximately 0.357 lb/A, ~0.9x the proposed maximum single application rate). 

The nature and the quantities of the radioactive residues were investigated in lettuce (immature 

and mature), white radish (top and root) and spring wheat (forage, hay, straw, chaff and grain) 

after plantback intervals (PBIs) of 30, 120 and 365 days. Although the metabolic profile was 

similar across the rotational crop matrices, significant differences were shown between the two 

different radiolabels (benzoyl or butylphenyl), and the metabolic pathway in rotational crops is 

significantly different than that in primary crops. 
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Following application to bare soil, the degradation of cyflumetofen in rotational crops appears to 

follow four major pathways: hydrolytic cleavage of the parent molecule results in the formation 

of the metabolite B-1 (trifluoromethyl benzoic acid) - which is only detectable with the benzoyl 

label - and one or several butylphenyl label-specific intermediates which were not identified. 

The predominant metabolite in the case of the benzoyl label, trifluoroacetic acid (TFA), can be 

derived from cyflumetofen or the metabolite B-1. The butylphenyl label-specific cleavage 

products (such as the goat metabolite A-2) which is formed by hydrolysis of the formic acid 

ester, decarboxylation and hydrolytic detachment of the trifluoromethyl benzoyl moiety) are 

further transformed to a series of minor (<0.01 ppm), mainly unidentified medium-polar 

metabolites.

Livestock

The metabolism of cyflumetofen was investigated in lactating goats following repeated oral 

administration of 14C- cyflumetofen, labeled either in the benzoyl ring (benzoyl label) or in the 

tert-butylphenyl ring (butylphenyl label). Cyflumetofen was administered by gavage (two 

animals per label) for twelve (benzoyl label) or ten (butylphenyl Label) consecutive days at a 

nominal dose of 12 ppm feed (~171x the maximum reasonably balanced diet (MRBD)). There 

are no poultry feedstuffs associated with the proposed uses; therefore a poultry metabolism study

is not required and was not submitted.

Cyflumetofen and its metabolites were rapidly excreted by lactating goats, mainly via feces and 

urine. For both labels, only low portions of the administered dose were retained in edible tissues 

and organs. In edible tissues, parent cyflumetofen was only identified in fat of the benzoyl label. 

Metabolite B-1 was identified in all matrices of the benzoyl label as the sole benzoyl labelspecific metabolite. The major metabolic pathway of cyflumetofen in lactating goats comprises 

hydrolytic cleavage of the trifluoromethylbenzoyl moiety resulting in metabolite B-1. 

The submitted goat metabolism studies adequately address the requirement to elucidate the 

nature of the residue for cyflumetofen in ruminants. Based on the ruminant metabolism data and

the limited livestock feedstuffs associated with this petition, the proposed uses can be classified 

as 40 CFR 180.6 (a)(3), no reasonable expectation of finite residues in ruminant livestock 

commodities. However, this decision may be reconsidered if the use pattern changes and/or 

additional livestock feedstuffs are proposed in the future. Additionally, if additional uses are 

proposed that contain poultry feedstuffs, a poultry metabolism study will be required.

5.1.2 Summary of Environmental Degradation

Cyflumetofen has limited solubility in water (28 ug/L) and is quite lipophilic; therefore, it is 

expected to absorb to foliage surfaces and soil (Koc of 131,826) at the site of application. Once 

deposited, either at the site of application or farther afield through spray drift (or through erosion 

of cyflumetofen bearing soil particles), the parent molecule is expected to degrade quickly

through multiple fate processes (half-lives of hours to several days) under environmental 

conditions. Cyflumetofen forms many degradates with a wide range of fate properties (e.g., from 

highly soluble to less soluble than the parent). The two bonds on either side of the cyano group 

readily break in all of the fate studies involving water other than photolysis (hydrolysis, aerobic 

and anaerobic soil and aquatic metabolism, and terrestrial field dissipation studies), which means 
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that cyflumetofen is not persistent in the environment (Hydrolysis DT50 = 9.75 hours at pH 7) 

and rapidly converts to degradates via biotic and abiotic hydrolysis reactions. Many degradates 

are much more persistent than the parent. 

5.1.3 Comparison of Metabolic Pathways

Metabolism in plants was similar, with parent cyflumetofen being the primary component in 

most matrices. Other identified metabolites were B-1, A-12, AB-6 and AB-7. The major 

metabolic pathway in plants consisted of the hydrolytic cleavage of the benzoyl moiety leading 

to metabolite B-1 followed by conjugation. Metabolites AB-6 and AB-7 were primarily

photochemical metabolites found as surface residue in crop matrices. Residues in plants tend to 

be surface residues.

Metabolism in rotational crops was seen to be very different from that in primary crops. 

Depending on the position of the radiolabel, either trifluoroacetic acid (TFA) or a series of 

medium-polar metabolites in minor concentrations were detected.

Metabolism studies performed in rat and goat showed a common metabolic pathway in animals. 

In both goat and rat, cyflumetofen is rapidly absorbed and excreted. Cyflumetofen is 

metabolized in goat and rat primarily by hydrolytic cleavage of the trifluoromethylbenzoyl 

moiety resulting in metabolite B1 (trifluoromethylbenzoic acid) (goat and rat) and A-18 (rat) as 

primary metabolites. Another minor pathway includes hydroxylation and oxidation of the tertbutyl side chain. The metabolic pathways in both rat and goat were qualitatively similar.

5.1.4 Residues of Concern Summary and Rationale

The HED Residues of Concern Knowledgebase Sub-committee (ROCKS) considered the 

available data on the nature and magnitude of residues of cyflumetofen and concluded that for 

the subject crops, the parent compound only be included for tolerance enforcement and dietary

risk assessment. At this time, there is no reasonable expectation of finite residues in livestock so 

the committee had no recommendation on residues of concern in livestock. For drinking water, 

the ROCKS recommended including the parent cyflumetofen and all of the AB degradates. The 

reasoning behind these recommendations is as follows: 

Primary Crops: Parent cyflumetofen was detected as a main residue in the primary crop 

metabolism studies and crop field trials. It is considered an appropriate marker of misuse on 

primary crops and is recommended as the residue of concern for tolerance enforcement. The 

metabolite B-1 was also a major residue in some commodities. The ROCKS recommended 

inclusion of parent only for risk assessment purposes based on the following weight of evidence 

analysis: 

 The structure of metabolite B-1 is unlike the parent (i.e., it is a carboxylate and its 

molecular weight is 2 times lower); 

 The octanol:water partition coefficient of parent cyflumetofen is much higher than that of 

B-1 (Log P = 4.3 versus 2.5, respectively), indicating that B1 is much more water soluble. 

As a carboxylate, B-1is also likely to be charged (predicted pKa = 3.12) in the body (pH 
Cyflumetofen Human Health Risk Assessment DP No. D398246

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7.4) and readily excretable by renal anion transporters, decreasing the likelihood of reabsorption; 

 Rat metabolism studies show that B-1 is likely a detoxification product of parent 

cyflumetofen. Once formed, B-1 undergoes conjugation with glutathione (phase II 

metabolism) resulting in a higher excretion potential; 

 The structure of metabolite B-1 resembles benzoic acid (the trifluoromethyl group in B-1 is 

unlikely to change reactivity), which exhibits very low single- and repeated-dose toxicity

(NOAEL  800 mg/kg/day; http://toxnet.nlm.nih.gov, accessed 02/25/2013).

If new uses are requested in the future, additional metabolism studies may be required to 

reconsider the residues of concern in plants.

Rotational Crops: The major residue found in rotational crops was trifluoroacetic acid (TFA). 

The ROCKS recommended excluding it from risk assessment consideration for the following 

reasons: 1) TFA is a polar, low molecular weight organic acid with no structural resemblance to 

the parent molecule, 2) the toxicity of TFA is due to its strong acidity (pKa<1) and at 

physiological pH, TFA would exist as an anion and not the acid and would therefore not exhibit 

acid toxicity (http://www.afeas.org/environ.html), and 3) it is not likely to contribute to toxic 

effects found for cyflumetofen. Since there were no major residues of toxicological concern in 

the rotational crop studies, no residues of concern for tolerance enforcement or risk assessment 

were identified.

Livestock: Based on the submitted ruminant metabolism data and the limited feedstuffs 

associated with this petition, the ROCKS concurred with the team that the proposed uses can be 

classified as 40 CFR 180.6 (a)(3), no reasonable expectation of finite residues in livestock 

commodities. The residues of concern may be reconsidered if the use pattern changes and/or 

additional livestock feedstuffs are proposed in the future.

Drinking Water: The ROCKS recommended inclusion of parent cyflumetofen, the degradates 

AB-1, AB-7, AB-11, AB-15, and three dimers of AB-1 (AB-1 dimer, AU16 and AU17) as 

residues of concern in the drinking water risk assessment. Estimated drinking water 

concentrations would be based on total residues of parent and the degradates listed above, 

expressed as parent cyflumetofen. Since the degradates are structurally similar to the parent 

cyflumetofen, similar toxicity is assumed. The degradate B-1 is not recommended based on the 

rationale explained above and B-3 is excluded as well based on its structure being significantly 

distinct from the parent. The octanol:water partition coefficient of parent cyflumetofen is much 

higher than B-3, and no alerts were reported in DEREK while the parent show alerts that may be 

correlated to effects observed in the toxicity studies. The other degradates containing the tbutylphenyl moiety, A-1, A-2, A-12, and A-18, are excluded based on structural differences to 

parent, significantly lower octanol:water partition coefficients than parent cyflumetofen, or 

presence in the rat metabolism study (i.e. A-12 and A-18). 
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The residues of concern for cyflumetofen are summarized below in Table 5.1.4.

Table 5.1.4. Summary of Metabolites and Degradates Recommended for inclusion in the Risk

Assessment and Tolerance Expression

Matrix Residues Included In Risk 

Assessment

Residues Included In 

Tolerance Expression

Plants1 Cyflumetofen Cyflumetofen

Rotational crops NA NA

Livestock (ruminants and poultry) NA NA

Drinking Water Cyflumetofen + AB 

Degradates2 NA

NA – Not applicable. 

1

If new uses on small grains, leafy vegetables and root/tuber crops are proposed in the future, then additional metabolism studies 

may be required to reconsider the residues of concern.

2 AB degradates include AB-1, AB-7, AB-11, AB-15, and three dimers of AB-1 (AB-1 dimer, AU16 and AU17). Refer to 

Appendix B for the names and/or chemical structures of the AB degradates.

5.2 Food Residue Profile

The results from plant metabolism studies in mandarin, eggplants, and apples conducted 

following a foliar treatment of formulated cyflumetofen indicate that the major component of the 

extractable residue was unchanged parent cyflumetofen in both fruit and leaves, and that residues 

are generally low. The only major metabolite found in/on fruits was metabolite B-1 (free and 

conjugate), with residues exceeding 10% of the TRR in mandarin and eggplants only. The 

highest residues are generally found in the foliage (leaves) of plants, and not in the fruit itself. 

The residue is expected to be a surface residue consisting of primarily parent compound and 

minor photolytic degradates, as the majority of the radioactivity was removed by acetonitrile 

surface rinses. The available metabolism data in plants shows that cyflumetofen undergoes 

limited translocation or degradation.

Adequate residue chemistry data have been provided for cyflumetofen. Field trials are of 

adequate number and geographic representation and showed levels of cyflumetofen residues 

found in the edible portions of target crops ranging from <0.01 ppm (almonds and pecan 

nutmeat) to 0.5 ppm (citrus, pome fruit, tomato, strawberry and grapes). Residues decline with 

increasing pre-harvest intervals (PHIs). Levels of cyflumetofen residues in livestock feedstuffs 

were higher and ranged from 0.3-2.0 ppm (see Appendix E Table E.1 for a summary of the 

residue data for cyflumetofen). The data were generated using a validated data collection 

method and are adequately supported by frozen storage stability data, with the exception of 

tomato which was corrected for residue loss during freezer storage. Sufficient processing studies 

were submitted for apple, citrus, tomato, and grape to elucidate the fate of cyflumetofen in 

processed commodities derived from these crops, with concentration only seen in citrus oil and 

raisins. HED determined that the proposed uses of cyflumetofen are classified as 180.6 (a) (3), 

no reasonable expectation of finite residues with respect to residues in livestock commodities. 

Metabolism in rotational crops was seen to be very different from that in primary crops. 

Depending on the position of the radiolabel, either trifluoroacetic acid (TFA) or a series of 

medium-polar metabolites in minor concentrations were detected. 
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5.3 Water Residue Profile

Cyflumetofen is a new active ingredient; therefore, there are no monitoring data currently 

available for the parent molecule or its residues of concern in drinking water. Estimated drinking 

water concentrations (EDWCs) were generated using OPP’s standard suite of models. The 

EDWCs from surface water sources were calculated using Tier II models Pesticide Root Zone 

Model (PRZM) and Exposure Analysis Modeling System (EXAMS). Estimated groundwater 

EDWCs were calculated using the model Screening Concentrations in Ground Water (SCIGROW, version 2.3, 07/29/03) as well as Pesticide Root Zone Model-Groundwater (PRZM-GW,

version 1.0, December 11, 2012).

Maximum application rates for cyflumetofen as a high-end estimate of exposure in drinking 

water were modeled based on the proposed labels. In accord with recommendations of the 

ROCKS, a total toxic residues approach was used for the modeling that included cyflumetofen, 

the degradates AB-1, AB-7, AB-11, AB-15, and three dimers of AB-1 (AB-1 dimer, AU16 and 

AU17). Surface water EDWCs were corrected for a percent cropped area (PCA) of 0.91. The 

PRZM/EXAMS surface water simulations of a NY grapes scenario produced the highest surface 

water EDWCs of 4.7 μg/L for acute exposure, 0.33 μg/L for chronic exposure, and 0.28 μg/L for 

long-term cancer exposure. The SCI-GROW groundwater simulation produced the highest 

groundwater EDWC of 2.4 × 10-3μg/L for both acute and chronic exposures. The maximum 

surface and ground water EDWCs for use in the human health risk assessment for cyflumetofen 

are shown in Table 5.3.

Table 5.3. Summary of Estimated Surface Water and Groundwater Concentrations for Cyflumetofen

Scenario Surface Water Conc., ppb a Groundwater Conc., ppb b

Acute 4.7 0.0024

Chronic (non-cancer) 0.33 0.0024

Chronic (cancer) 0.28 Not Determined

a

From the Tier II PRZM-EXAMS (NY grape scenario)

b

From the SCI-GROW model

Highest value for use in risk assessment is in bolded

5.4 Dietary Risk Assessment

A chronic aggregate dietary food and drinking water exposure and risk assessment was 

conducted using the Dietary Exposure Evaluation Model software with the Food Commodity

Intake Database (DEEM-FCID) Version 3.16. This software uses 2003-2008 food consumption 

data from the U.S. Department of Agriculture’s (USDA’s) National Health and Nutrition 

Examination Survey, What We Eat in America, (NHANES/WWEIA). 

No acute dietary exposure and risk analysis was performed since there were no appropriate 

studies identified in the toxicology database that demonstrated evidence of toxicity attributable to 

a single dose.
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5.4.1 Description of Residue Data Used in Dietary Assessment

The chronic dietary exposure and risk analysis was based on tolerance-level residues, 100% crop 

treated assumptions, and both empirical and default processing factors. Empirical processing 

factors derived from apple, orange, grape, and tomato processing studies were incorporated into 

the assessment for all processed commodities with the exception of dried tomato, where the 

DEEM default processing factor was used. Estimates of residues in drinking water were 

directly incorporated in the assessments (see Section 5.3).

5.4.2 Percent Crop Treated Used in Dietary Assessment

The chronic dietary exposure and risk assessment assumed 100% crop treated for all 

commodities included in the assessment.

5.4.3 Acute Dietary Risk Assessment

As previously stated, no acute dietary exposure and risk analysis was performed since there were 

no appropriate studies identified in the toxicology database that demonstrated evidence of 

toxicity attributable to a single dose.

5.4.4 Chronic Dietary Risk Assessment

A partially refined chronic analysis was conducted that was based on tolerance-level residues, 

100% crop treated (%CT) assumptions, and both empirically derived and default processing 

factors. Using assumptions considered to be highly protective of human health, the chronic 

dietary risk estimates are below HED’s level of concern (<100% of the chronic population 

adjusted dose (cPAD)) and range from <1% of the cPAD for the general U.S. population to 2.3% 

of the cPAD for the highest exposed population subgroup of children 1-2 years old.

5.4.5 Cancer Dietary Risk Assessment

Cyflumetofen has been classified as having “Suggestive Evidence of Carcinogenic Potential” 

based on the presence of a single tumor type (thyroid c-cell) in one sex (male) and one species 

(rat), and the lack of concern for mutagenicity. The Agency has determined that quantification of 

risk using a non-linear approach (i.e., reference dose (RfD) will adequately account for all 

chronic toxicity, including carcinogenicity, that could result from exposure to cyflumetofen (see 

Section 4.5.3). The results of the chronic dietary risk assessment are discussed in Section 5.4.4. 
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5.4.6 Summary Table

Table 5.4.6. Summary of Chronic Dietary (Food + Drinking Water) Exposures and Risk for Cyflumetofen

Population Subgroup cPAD, 

mg/kg/day Exposure, mg/kg/day Risk, % cPAD

U.S. Population

0.17

0.000829 <1

All infants (< 1 year) 0.002493 1.5

Children 1-2 yrs 0.003842 2.3

Children 3-5 yrs 0.002562 1.5

Children 6-12 yrs 0.001275 <1

Youth 13-19 yrs 0.000573 <1

Adults 20-49 yrs 0.000527 <1

Adults 50-99 yrs 0.000596 <1

Females 13-49 yrs 0.000548 <1

*The subpopulation with the highest risk estimates is bolded

6.0 Residential (Non-Occupational) Exposure/Risk Characterization

Cyflumetofen is being proposed for use on ornamentals (i.e., residential landscape areas) and 

may be applied in residential settings (SultanTM EPA Reg. No. 7969-GGT). Therefore, 

residential handler and residential post-application exposure assessments have been conducted

according to HED’s 2012 Residential Standard Operating Procedures (SOPs)1. 

6.1 Residential Handler Exposure

The proposed uses of cyflumetofen on ornamentals may result in residential handler exposure. 

Residential handler exposure is expected to be short-term in duration as intermediate- or longterm exposures are not likely because of the intermittent nature of applications by homeowners. 

Residential handlers are assumed to be wearing short-sleeved shirts, short pants, shoes and socks 

during application of cyflumetofen (i.e., no protective equipment). The assessments were 

conducted assuming the maximum application rate (0.2 lbs ai/acre, 0.002 lbs ai/gallon) and used 

unit exposure values and estimates for area treated or amount handled along with algorithms 

taken from HED’s 2012 Residential SOPs. 

The quantitative exposure/risk assessment developed for residential handlers is based on the 

following scenarios: 

 Mixing/Loading/Applying Liquid to ornamentals with Hose-End Sprayer

 Mixing/Loading/Applying Liquid to ornamentals with Manually-pressurized handwand

 Mixing/Loading/Applying Liquid to ornamentals with Backpack

 Mixing/Loading/Applying Liquid to ornamentals with a Sprinkler Can

Since no dermal hazard was identified for cyflumetofen in the toxicological database, only 

inhalation exposure assessments were conducted for residential handlers. Inhalation margins of 

exposure (MOEs) are above the LOC of 100 for all scenarios assessed and are not of concern

 

1 Available: http://www.epa.gov/pesticides/science/residential-exposure-sop.html
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(MOEs ≥ 100). Short-term inhalation residential handler estimated exposure and risk estimates

are shown in Table 6.1 below.

Table 6.1. Short-Term Residential Handler Non-cancer Exposure and Risk Estimates for Cyflumetofen

Exposure Scenario Level of 

Concern

Inhalation 

Unit 

Exposure 

(mg/lb ai)

Maximum 

Application 

Rate1

(lbs ai/gallon)

Area Treated 

or Amount 

Handled Daily2

(gallons)

Inhalation

Dose 

(mg/kg/day)3 MOE4

Mixer/Loader/Applicator

Manually-pressurized 

handwand

100

0.018 0.002 5 0.0000023 7,300,000

Hose-end Sprayer 0.0014 0.002 11 0.00000039 43,000,000

Backpack 0.14 0.002 5 0.000018 940,000

Sprinkler can 0.0014 0.002 5 0.00000018 94,000,000

1 Based on registered or proposed label (EPA Reg. No. 7969-GGT)

2 Based on HED’s 2012 Residential SOPs 

3 Inhalation Dose = Inhalation Unit Exposure (mg/lb ai) × Application Rate (lb ai/acre or gal) × Area Treated or Amount 

Handled (A/day or gallons/day) ÷ BW (80 kg)

4 Inhalation MOE = Inhalation NOAEL (16.5 mg/kg/day) ÷ Inhalation Dose (mg/kg/day)

6.2 Post-Application Exposure

There is the potential for post-application exposure to individuals (adults and children 6 < 11 

years old) as a result of being in an environment that has been previously treated with 

cyflumetofen. However, since no dermal hazard was identified in the toxicity database for 

cyflumetofen, a quantitative residential post-application dermal risk assessment is not required

and was not completed. Post-application inhalation exposure while performing activities in 

previously treated gardens was not assessed due to the low vapor pressure (4.43 x 10-8 mm Hg @ 

25 oC) and the expected dilution in outdoor air after an application has occurred. 

For the residential ornamental/landscape use scenario, post-application non-dietary ingestion 

exposure is not assessed for children (1 < 2 years old). The potential for exposure via nondietary ingestion for young children is greatly diminished since young children are not expected 

to engage in the types of activities associated with these areas (e.g., gardening) or utilize these 

areas for prolonged periods of play.

6.3 Residential Risk Estimates for Use in Aggregate Assessment

Table 6.3 reflects the residential risk estimates that are recommended for use in the aggregate 

assessment for cyflumetofen.

 The recommended residential exposure for use in the adult (male and female) aggregate 

assessment reflects inhalation exposure from mixing/loading/applying the liquid 

cyflumetofen formulation with a backpack sprayer (0.002 lbs ai/gallon).

 There is no recommended residential contribution to the children aggregate assessment. 
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Table 6.3. Recommendation for the Short-Term Residential Exposures for the Cyflumetofen Aggregate 

Assessment1

Lifestage

Residential Handler

Dose (mg/kg/day)2 MOE3

Dermal Inhalation Total Dermal Inhalation Total

Short-Term

Adult Handler N/A 0.000018 0.000018 N/A 940,000 940,000

1 Bolded risk estimates should contribute to the residential exposure portion of the aggregate assessment. 

2 Residential Handler Dose = the highest handler dose for each applicable lifestage of all scenarios assessed from Table 6.1. Total = dermal + 

inhalation.

3 Residential Handler MOE = the MOEs associated with the highest doses identified in Table 6.1. Total = 1 ÷ (1/Dermal MOE) + (1/Inhalation 

MOE).

6.4 Residential Bystander Post-application Inhalation Exposure

Based on the Agency's current practices, a quantitative post-application inhalation exposure 

assessment was not performed for cyflumetofen at this time primarily because of the low acute 

inhalation toxicity (Toxicity Category IV), low vapor pressure (4.43 x 10-8 mm Hg @ 25 oC), 

and the low proposed use rate (0.2 lb ai/A). However, volatilization of pesticides may be a 

source of post-application inhalation exposure to individuals nearby pesticide applications. The 

Agency sought expert advice and input on issues related to volatilization of pesticides from its 

Federal Insecticide, Fungicide, and Rodenticide Act Scientific Advisory Panel (SAP) in 

December 2009, and received the SAP’s final report on March 2, 20102. The Agency is in the 

process of evaluating the SAP report and may, as appropriate, develop policies and procedures to 

identify the need for and, subsequently, the way to incorporate post-application inhalation 

exposure into the Agency's risk assessments. If new policies or procedures are developed, the 

Agency may revisit the need for a quantitative post-application inhalation exposure assessment 

for cyflumetofen.

6.5 Spray Drift

Spray drift is always a potential source of exposure to residents nearby to spraying operations. 

This is particularly the case with aerial application, but, to a lesser extent, could also be a 

potential source of exposure from the ground application method employed for cyflumetofen. 

The Agency has been working with the Spray Drift Task Force, EPA Regional Offices and State 

Lead Agencies for pesticide regulation and other parties to develop the best spray drift 

management practices (see the Agency’s Spray Drift website for more information3). The 

Agency has completed its evaluation of the new database submitted by the Spray Drift Task 

Force, a membership of U.S. pesticide registrants, and is developing a policy on how to 

appropriately apply the data and the AgDRIFT computer model to its risk assessments for 

pesticides applied by air, orchard airblast and ground hydraulic methods. After the policy is in 

place, the Agency may impose further refinements in spray drift management practices to reduce 

off-target drift with specific products with significant risk estimates associated with drift.

 

2 Available: http://www.epa.gov/scipoly/SAP/meetings/2009/120109meeting.html

3 Available: http://www.epa.gov/opp00001/factsheets/spraydrift.htm 
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7.0 Aggregate Exposure/Risk Characterization

In accordance with the FQPA, HED must consider and aggregate pesticide exposures and risks 

from three major sources: food, drinking water, and residential exposures. In an aggregate 

assessment, exposures from relevant sources are added together and compared to quantitative 

estimates of hazard (e.g., a NOAEL or PAD), or the risks themselves can be aggregated. When 

aggregating exposures and risks from various sources, HED considers both the route and 

duration of exposure. For cyflumetofen, potential exposures from food, drinking water, and 

residential scenarios were aggregated. This assessment is based on the changes in the new 

Residential SOPs implemented in January of 2012. 

7.1 Acute Aggregate Risk

Acute aggregate risk estimates include exposure to residues in food and water alone; therefore, 

the acute aggregate risk estimates are equivalent to the acute dietary risk assessment. However, 

for cyflumetofen, no toxic effects attributable to a single dose were observed in the toxicology

database. As a result, an acute aggregate risk assessment is not required for this chemical. 

7.2 Short-Term Aggregate Risk

There is a potential for short-term exposure to cyflumetofen via dietary and residential exposure 

pathways. To estimate short-term aggregate risk, HED therefore combined chronic dietary (food 

and water) exposures (as a measure of average background dietary exposure) with short-term 

residential exposures. These pathways lead to exposure via oral (background) and inhalation 

(primary) routes only, since no dermal hazard has been identified for cyflumetofen.

The most conservative residential exposure scenario was chosen for the adult population which 

reflects inhalation exposure from mixing/loading/applying the liquid cyflumetofen formulation 

with a backpack sprayer (refer to Section 6.3). For background dietary exposure, the adult subpopulation with the highest exposure (adults 50-99) was chosen since this is protective for all 

other adult sub-populations. There are no residential exposures expected for children (refer to 

Section 6.2); therefore a short-term aggregate risk assessment for children is not required and 

was not performed.

Short-term aggregate margins of exposure for adults (all adult sub-populations) are above the 

LOC of 100 and are not of concern (MOEs ≥ 100). Short-term estimated exposures and risks are 

shown below in Table 7.2. 
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Table 7.2. Short-Term Aggregate Risk Calculations

Population

Short- or Intermediate-Term Scenario

NOAEL 

mg/kg/day LOC1

Max 

Allowable 

Exposure2

mg/kg/day

Average 

Food and 

Water 

Exposure3

mg/kg/day

Residential 

Exposure4

mg/kg/day

Total 

Exposure5

mg/kg/day

Aggregate 

MOE (food, 

water, and 

residential) 6

Adults 50-99 16.5 100 0.165 0.000596 0.000018 0.000614 27,000

1

Intraspecies factor= 10x; Interspecies factor = 10x

2 Maximum Allowable Exposure (mg/kg/day) = NOAEL (16.5 mg/kg/day)/LOC (100)

3 Average food and water exposure for adults = chronic dietary exposure for adults 50-99 (the highest exposed adult subpopulation)

4 Residential Exposure = [Inhalation Exposure]

5 Total Exposure = Avg Food & Water Exposure + Residential Exposure) - Refer to Table 6.3

6 Aggregate MOE = [NOAEL / (Avg Food & Water Exposure + Residential Exposure)]

7.3 Chronic Aggregate Risk

As there are no uses that are expected to result in long-term residential exposure, long-term 

(chronic) aggregate risk includes only chronic dietary (food and water) exposure. As noted in 

Section 5.4.4, there are no chronic dietary risks of concern for cyflumetofen.

7.4 Cancer Aggregate Risk

Cancer aggregate risk estimates for the general U.S. population include chronic exposure to 

residues in food and water as well as residential sources. Cyflumetofen has been classified as 

having “Suggestive Evidence of Carcinogenic Potential” based on the presence of a single tumor 

type (thyroid c-cell) in one sex (male) and one species (rat), and the lack of concern for 

mutagenicity. The Agency has determined that quantification of risk using a non-linear approach 

(i.e., reference dose (RfD) will adequately account for all chronic toxicity, including 

carcinogenicity, that could result from exposure to cyflumetofen (see Section 4.5.3). Based on 

this, since the chronic dietary risk assessment (refer to Section 5.4.4) is considered to be 

protective of any cancer effects, a separate quantitative cancer aggregate risk assessment is not 

required. 

8.0 Cumulative Exposure/Risk Characterization

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 cyflumetofen and any other substances and cyflumetofen does not appear to produce a toxic 

metabolite produced by other substances. For the purposes of this tolerance action, therefore, 

EPA has not assumed that cyflumetofen has a common mechanism of toxicity with other 

substances. For information regarding EPA’s efforts 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 procedures for cumulating effects from substances found to have 

a common mechanism on EPA’s website at http://www.epa.gov/pesticides/cumulative/.
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9.0 Occupational Exposure/Risk Characterization

An occupational exposure and risk assessment was conducted to support the proposed uses of 

cyflumetofen. Full details of that assessment are included in the occupational and residential 

memorandum listed in the reference section and the results are briefly summarized here.

9.1 Short-/Intermediate- Term Handler Risk

Cyflumetofen is a selective contact miticide that is effective on all mite life stages. Application 

methods, maximum application rates and use sites were summarized previously in Table 3.3. 

The occupational exposure and risk assessment generally addresses risks to workers exposed in 

an occupational setting via the dermal and inhalation routes of exposure. However, since no 

dermal hazard was identified in the toxicity database for cyflumetofen, a quantitative dermal 

assessment is not required and risks were quantitatively assessed for inhalation exposure only. 

Based on the proposed use pattern of cyflumetofen, short- and intermediate-term exposures are 

anticipated for handlers for the following reasons: (1) the product can be applied twice per 

season (2) the product can be applied to multiple application sites, (3) there may be a large 

agribusiness and/or commercial applicators who may apply a product over a period of weeks, 

and (4) repeated use of miticides with similar modes of action can lead to build up therefore 

rotating miticides with different modes of action reduces the potential for developing mite 

resistance. Long-term exposure is not expected for the proposed use patterns. 

Estimates of inhalation exposure were calculated for various levels of personal protective 

equipment (PPE). Results are presented for “baseline” level of attire defined as a single layer of 

clothing consisting of a long sleeved shirt, long pants, shoes plus socks, no protective gloves, and 

no respirator, as well as baseline attire with various levels of PPE as necessary (e.g., gloves, 

respirator, etc.). The cyflumetofen product labels direct mixers, loaders, applicators and other 

handlers to wear long-sleeved shirts, long pants, protective eyewear, chemical-resistant gloves, 

and shoes plus socks.

All occupational handler scenarios assessed for the proposed uses of cyflumetofen resulted in 

estimated inhalation margins of exposure (MOEs) above the LOC of 100 for all scenarios 

assessed and, therefore, are not of concern (MOEs ≥100). Occupational handler risk estimates 

are shown in Table 9.1. 

Table 9.1. Occupational Handler Non-Cancer Exposure and Risk Estimates for Cyflumetofen

Exposure 

Scenario Crop or Target

Inhalation Unit 

Exposure 

(μg/lb ai)1 Maximum

Application 

Rate2

Area 

Treated 

or 

Amount 

Handled 

Daily3

Inhalation

Baseline Dose 

(mg/kg/day)4 MOE5

Mixer/Loader

Aerial Tomato 0.219

0.2 lb ai/acre

350 0.000191 86,000

Airblast

Nursery 

(ornamentals, 

container stock)

0.219 20 0.000011 1,500,000

Citrus Fruit, Grapes, 0.219 40 0.0000219 750,000
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Table 9.1. Occupational Handler Non-Cancer Exposure and Risk Estimates for Cyflumetofen

Exposure 

Scenario Crop or Target

Inhalation Unit 

Exposure 

(μg/lb ai)1 Maximum

Application 

Rate2

Area 

Treated 

or 

Amount 

Handled 

Daily3

Inhalation

Baseline Dose 

(mg/kg/day)4 MOE5

Pome Fruit, Tree Nut 

Group

Groundboom

Field-grown 

ornamental crops 0.219 40 0.000022 750,000

Nursery 

(ornamentals,

container stock)

0.219 60 0.000033 500,000

Greenhouse 

(ornamentals, roses, 

cut flowers, 

container stock)

0.219 60 0.000033 500,000

Citrus Fruit, Grapes, 

Pome Fruit, 

Strawberry, Tomato, 

Tree Nut Group

0.219 80 0.000044 380,000

Applicator

Aerial Tomato 0.068

0.2 lb ai/acre

350 0.0000595 280,000

Airblast

Nursery 

(ornamentals, 

container stock)

4.71 20 0.000235 70,000

Citrus Fruit, Grapes, 

Pome Fruit, Tree Nut 

Group

4.71 40 0.000471 35,000

Groundboom

Field-grown 

ornamental crops 0.34 40 0.000034 490,000

Nursery 

(ornamentals,

container stock)

0.34 60 0.000051 320,000

Greenhouse 

(ornamentals, roses, 

cut flowers, 

container stock)

0.34 60 0.000051 320,000

Citrus Fruit, Grapes, 

Pome Fruit, 

Strawberry, Tomato, 

Tree Nut Group

0.34 80 0.000068 240,000

Flagger

Flagger Tomato 0.35 0.2 lb ai/acre 350 0.000306 54,000

Mixer/Loader/Applicator

Backpack 

(broadcast foliar)

Greenhouse 

(ornamentals, roses, 

cut flowers, 

container stock)

140

0.002 lb ai/gal

40 0.00014 120,000

Forestry 2.58 40 0.00000258 6,400,000

Nursery 

(ornamentals, 140 40 0.00014 120,000
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Table 9.1. Occupational Handler Non-Cancer Exposure and Risk Estimates for Cyflumetofen

Exposure 

Scenario Crop or Target

Inhalation Unit 

Exposure 

(μg/lb ai)1 Maximum

Application 

Rate2

Area 

Treated 

or 

Amount 

Handled 

Daily3

Inhalation

Baseline Dose 

(mg/kg/day)4 MOE5

container stock)

Landscaping, 

trees/shrubs/bushes 140 40 0.00014 120,000

Landscaping, 

plants/flowers 140 40 0.00014 120,000

Manuallypressurized 

Handwand

(broadcast foliar)

Greenhouse 

(ornamentals, roses, 

cut flowers, 

container stock)

30 40 0.00003 550,000

Nursery 

(ornamentals,

container stock)

Landscaping, 

trees/shrubs/bushes

Landscaping, 

plants/flowers

Interior landscaping

Mechanicallypressurized 

Handgun

(broadcast foliar)

Citrus Fruit, Tree 

Nut Group 3.9

0.002 lb ai/gal

1000 0.0000975 170,000

Greenhouse 

(ornamentals, roses, 

cut flowers, 

container stock)

120 1000 0.003 5,500

Nursery 

(ornamentals,

container stock)

3.9 0.002 lb ai/gal 1000 0.0000975 170,000

Landscaping, 

trees/shrubs/bushes 3.9 1000 0.0000975 170,000

1 Based on the “Occupational Pesticide Handler Unit Exposure Surrogate Reference Table” (September 2012); Level of 

mitigation: Baseline.

2 Based on registered or proposed label (Reg. No. 7969-GGT; 7969-GGA).

3 Exposure Science Advisory Council Policy #9.1.

4 Inhalation Dose = Dermal Unit Exposure (μg/lb ai) × Conversion Factor (0.001 mg/μg) × Application Rate (lb ai/acre or gal) × 

Area Treated or Amount Handled Daily (A or gal/day) ÷ BW (kg).

5 Inhalation MOE = Inhalation NOAEL (mg/kg/day) ÷ Inhalation Dose (mg/kg/day).
Cyflumetofen Human Health Risk Assessment DP No. D398246

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9.2 Short-/Intermediate- Term Post-Application Risk

9.2.1 Dermal Post-application Risk

There is the potential for post-application exposure to workers as a result of proposed uses of 

cyflumetofen. However, since no dermal hazard was identified in the toxicity database for 

cyflumetofen, a quantitative occupational post-application dermal risk assessment is not required 

and was not completed.

9.2.2 Inhalation Post-application Risk

Based on the Agency's current practices, a quantitative post-application inhalation exposure 

assessment was not performed for cyflumetofen at this time primarily because of the low acute 

inhalation toxicity (Toxicity Category IV), low vapor pressure (4.43 x 10-8 mm Hg @ 25 oC), 

and the low proposed use rate (0.2 lb ai/A). However, there are multiple potential sources of 

post-application inhalation exposure to individuals performing post-application activities in 

previously treated fields. These potential sources include volatilization of pesticides and 

resuspension of dusts and/or particulates that contain pesticides. The Agency sought expert 

advice and input on issues related to volatilization of pesticides from its Federal Insecticide, 

Fungicide, and Rodenticide Act Scientific Advisory Panel (SAP) in December 2009, and 

received the SAP’s final report on March 2, 20104. The Agency is in the process of evaluating 

the SAP report as well as available post-application inhalation exposure data generated by the 

ARTF and may, as appropriate, develop policies and procedures, to identify the need for and, 

subsequently, the way to incorporate occupational post-application inhalation exposure into the 

Agency's risk assessments. If new policies or procedures are put into place, the Agency may

revisit the need for a quantitative occupational post-application inhalation exposure assessment 

for cyflumetofen.

Furthermore, inhalation exposure during dusty mechanical activities such as shaking and 

mechanical harvesting tree nuts is another potential source of post-application inhalation 

exposure. However, the airblast applicator scenario is believed to represent a reasonable worst 

case surrogate estimate of post-application inhalation exposure during these dusty mechanical 

harvesting activities. The non-cancer inhalation risk estimate for commercial airblast application 

is not of concern (i.e., MOE > 100).

Although a quantitative occupational post-application inhalation exposure assessment was not 

performed, an inhalation exposure assessment was performed for occupational/commercial 

handlers. Handler exposure resulting from application of pesticides outdoors is likely to result in 

higher exposure than post-application exposure. Therefore, it is expected that these handler 

inhalation exposure estimates would be protective of most occupational post-application 

inhalation exposure scenarios.

Additionally, the Worker Protection Standard (WPS) for Agricultural Pesticides contains 

requirements for protecting workers from inhalation exposures during and after greenhouse 

applications through the use of ventilation requirements [40 CFR 170.110, (3) (Restrictions 

 

4 Available: http://www.epa.gov/scipoly/SAP/meetings/2009/120109meeting.html
Cyflumetofen Human Health Risk Assessment DP No. D398246

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associated with pesticide applications)]. It is assumed that the user will have met the ventilation 

requirement within the 12 hour REI (unless there is no ventilation capability, then the user must 

wait 24 hours). It is reasonable to assume that based on the WPS ventilation requirements, 

postapplication inhalation exposure will be negligible. 
Cyflumetofen Human Health Risk Assessment DP No. D398246

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10.0 References

I. Negrón-Encarnación, 26-March-2013, D408530, Cyflumetofen. Report of the Residues of 

Concern Knowledgebase Subcommittee (ROCKS). 

S. Shelat, 07-January-2014, D408532, Cyflumetofen. Occupational and Residential Exposure

Assessment for a Proposed Use on Citrus Fruit, Grapes, Pome Fruit, Strawberry, Tomato, 

Tree Nut Group, and Ornamentals.

J. Van Alstine, 03-July-2013, TXR No. 0056691, Cyflumetofen: Summary of the Hazard and 

Science Policy Council (HASPOC) Meeting of June 6, 2013: Recommendations on the 

Need for an Inhalation Study.

S. Wente, 12-June-2013, D410981, Drinking Water Exposure for Cyflumetofen Section 3 New 

Use on Citrus, Pome Fruits, Grapes, Strawberries, Tomatoes, Tree Nuts, and 

Ornamentals.

D. Wilbur, 26-June-2013, D408533, Cyflumetofen. Chronic Aggregate Dietary (Food and 

Drinking Water) Exposure and Risk Assessment for the Section 3 Registration Action on 

Grape, Strawberry, and Tomato.

D. Wilbur, 09-July-2013, D408531, Cyflumetofen. Petition for the Establishment of Permanent 

Tolerances and Registration for Use on Citrus (Crop Group 10-10), Pome Fruits (Crop 

Group 11-10), Tree Nuts (Crop Group 14-12), Grape, Strawberry, and Tomato. 

Summary of Analytical Chemistry and Residue Data.
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Appendix A. Toxicology Profile and Executive Summaries

A.1 Toxicology Data Requirements

The requirements (40CFR §158.340) for the food use of cyflumetofen are in Table A.1. 

Table A.1. Toxicology Data Requirements for Cyflumetofen

Test 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 Subchronic (rodent)

870.3150 Oral Subchronic (non-rodent)

870.3200 21/28-Day Dermal

870.3250 90-Day Dermal

870.3465 90-Day Inhalation

yes

yes

yes

no

yes

yes

yes

yes

no

yesa

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—Gene Mutation (mammalian)

870.5375 Mutagenicity—Structural Chromosomal Aberrations

870.5395 Mutagenicity—Other Genotoxic Effects 

870.5500 Mutagenicity—Other Genotoxic Effects

yes

yes

yes

yes

yes

yes

yes

yes

yes

yes

870.6100a Acute Delayed Neurotoxicity (hen)

870.6100b 90-Day Neurotoxicity (hen)

870.6200a Acute Neurotoxicity Screening Battery (rat)

870.6200b 90-Day Neurotoxicity Screening Battery (rat)

870.6300 Developmental Neurotoxicity

no

no

yes

yes

no

no

no

yes

yes

no

870.7485 General Metabolism

870.7600 Dermal Penetration 

870.7800 Immunotoxicity

yes

no

yes

yes

yes

yes

a

Inhalation study was waived by the HASPOC.
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A.2 Toxicity Profiles

Table A.2-1. Acute Toxicity Profile - Test Substance 

Guideline No. Study Type MRID(s) Results Toxicity Category

870.1100 Acute oral [Rat] 48542669 >2000 mg/kg III

870.1200 Acute dermal [Rat] 48542671 >5000 mg/kg IV

870.1300 Acute inhalation [Rat] 48542672-3 >2.65 mg/L IV

870.2400 Acute eye irritation [Rabbit] 48542675 Minimal irritant II

870.2500 Acute dermal irritation [Rabbit] 48542674 Not an irritant IV

870.2600 Skin sensitization [Guinea pig] 48542676 Skin sensitizer NA

Table A.2-2. Subchronic, Chronic and Other Toxicity Profile

Guideline Number/ 

Study Type

MRID(s) (year)/ 

Classification/Doses Results

870.3200

28-day dermal toxicity

[rat]

48542686 (2010)

0, 100, 300, 1000 mg/kg/day 

(mkd), 

6 hours/day for 5 days/week

Acceptable/Guideline

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

determined. 

28-day feeding study 

(rat)

48542678 (2004)

0, 100, 500, 1000, 5000 ppm 

M: 0, 7.5, 37.6, 75.1, 384 m/k/d

F: 0, 8.05, 40.8, 79.8, 409 m/k/d

Acceptable/nonguideline

The NOAEL is 500 ppm (37.6/40.8 mg/kg/day in 

males/females). The LOAEL is 1000 ppm (75.1/79.8 mg/kg/day 

in males/females) based on increased adrenal weight and 

histopathology. 

870.3100

90-Day feeding study 

[rat]

48542682 (2004)

0, 100, 300, 1000, 3000 ppm 

M:0, 5.4, 16.5, 54.5 167 m/k/d,

F: 0, 6.28, 19.0, 62.8,193 m/k/d

Acceptable/guideline

The NOAEL is 300 ppm (16.5/19.0 mg/kg/day in 

males/females). The LOAEL is 1000 ppm (54.5/62.8 mg/kg/day 

in males/females) based on the hematology and organ weight 

changes in the liver, adrenal, kidney and ovaries; and 

histopathology effects in the adrenals and the ovaries. 

28-day feeding study 

(mouse)

48542679 (2004)

0, 100, 500, 1000, 5000 ppm 

M: 0, 13.1, 67.2,135,663 m/k/d;

F: 0, 14.5, 74.9, 150, 763 m/k/d

Acceptable/nonguideline

The NOAEL is 1000 ppm (135/150 mg/kg/day in 

males/females). The LOAEL is 5000 ppm (663/763 mg/kg/day 

in males/females) based on increased adrenal weights and 

adrenal vacuolation.

870.3100

90-Day feeding study 

[mouse]

48542683 (2004)

0, 300, 1000, 3000, 10000 ppm 

M: 0, 35.4, 117, 348, 1200 m/k/d

F: 0, 45.0, 150, 447, 1509 m/k/d

Acceptable/guideline

The NOAEL is 1000 ppm (117/150 mg/kg/day in 

males/females). The LOAEL is 3000 ppm (348/447 mg/kg/day 

in males/females), based on decreased body weights in females, 

and diffuse hypertrophy and vacuolation of cortical cells in the 

adrenals in both sexes. 

870.3150

90-Day oral (capsule) 

study [dog]

48542684 (2003)

0, 30, 300, 1000 mkd (M/F) 

(capsule)

Acceptable/guideline

The NOAEL is 300 mg/kg/day. The LOAEL is 1000 mg/kg/day, 

based on decreased body weight and body weight gain, increased 

adrenal weights (males only) and vacuolation of the adrenals. 

870.3700

Prenatal developmental 

[rabbit]

48542706 (2003)

0, 50, 250, 1000 mkd

Gavage GD 6-28

Acceptable/guideline

The maternal NOAEL is 1000 mg/kg/day (the highest dose 

tested). 

The developmental NOAEL is 250 mg/kg/day. The 

developmental LOAEL is 1000 mg/kg/day based on changes in 

ossification, paw flexion and decreased fetal body weights. 

870.3700

Prenatal developmental

[rats]

48542704 (2001)

0, 50, 250, 1000 mkd

Gavage, GD 6-19

Acceptable/guideline

The maternal NOAEL is 50 mg/kg/day. The maternal LOAEL is 

250 mg/kg/day, based on an increase in adrenal weights and 

organ to body weight ratio. 

The developmental NOAEL is 50 mg/kg/day.The developmental 

LOAEL is 250 mg/kg/day, based on an increased incidence of 

incompletely ossified sternal centra. 
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Table A.2-2. Subchronic, Chronic and Other Toxicity Profile

Guideline Number/ 

Study Type

MRID(s) (year)/ 

Classification/Doses Results

870.3800

Reproduction and 

fertility effects

[rat]

48542702 (2004)

0, 150, 500, 1500 ppm

(0,9.2, 30.6, 89.4/0, 13.8, 46.6, 

141.1 mkd, M/F)

Acceptable/guideline

The parental NOAEL is 150 ppm (9.2/13.8 mg/kg/day in 

males/females). Parental LOAEL is 500 ppm (30.6/46.6 

mg/kg/day in males/females) based on effects on the adrenals 

(increased organ weights and histopathology). 

The reproductive NOAEL in females is 150 ppm (13.8 

mg/kg/day). Reproductive LOAEL in females is 500 ppm (46.6 

mg/kg/day) based on hormone changes (significantly decreased 

FSH, progesterone, and 17 β-estradiol). The reproductive the 

NOAEL in males is 1500 ppm (89.4 mg/kg/day); the LOAEL in 

males is not determined, 

The offspring NOAEL is 150 ppm (9.2/13.8 mg/kg/day in 

males/females).Offspring LOAEL is 500 ppm (30.6/46.6 

mg/kg/day in males/females) based on effects on the adrenals 

(increased organ weights and histopathology) in both sexes. 

870.4100a

Chronic toxicity

[rat]

48542696 (2004)

0, 50, 150, 500,1500 ppm

(0, 4.9, 16.5, 49.5/0, 6.1, 20.3, 

61.9 mkd, M/F)

Acceptable/guideline

The NOAEL is 500 ppm (16.5/20.3 mg/kg/day in 

males/females). The LOAEL is 1500 ppm (49.5/61.9 mg/kg/day 

in males/females) based on increased adrenal weights, 

hyperplasia and hypertrophy of the adrenal cortex in both sexes, 

and luminal dilatation of the gland in the uterine horn in females. 

870.4100a

Chronic toxicity 

[rat]

49029701 (2013)

0, 6000 ppm

(0, 250/319 mkd, M/F)

Acceptable/guideline

In this supplemental study, the LOAEL was 6000 ppm (250/319 

mg/kg bw/day in males/females) based on increased adrenal 

weights accompanied by gross pathology and histopathology 

lesions noted in both sexes, vacuolation of the interstitial gland 

cell of the ovary and hyperplasia of the interstitial cell of the 

testes. Only one dose was tested.

870.4100b

Chronic toxicity 

[dog]

48542685 (2008)

0,30, 300, 1000 mkd (capsule)

Acceptable/guideline

The NOAEL is 30 mg/kg/day. The LOAEL is 300 mg/kg/day, 

based on vacuolation and histopathology findings in the adrenals. 

870.4200a

Carcinogenicity

[rat]

46542697 (2004)

0, 50, 150, 500,1500 ppm

(0, 4.9, 16.5, 49.5/0, 6.1, 20.3, 

61.9 mkd, M/F)

Acceptable/guideline

The NOAEL is 500 ppm (16.5/20.3 mg/kgkday for males and 

females). The LOAEL is 1500 ppm (49.5/61.9 mg/kg/day in 

males/females) based on increased adrenal weights, hyperplasia 

and hypertrophy of the adrenal cortex in both sexes, and luminal 

dilatation of the gland in the uterine horn in females.

There was no treatment related increase in tumor incidence when 

compared to controls.

870.4200a

Carcinogenicity

[rat]

49226601 (2013)

0 or 6000 ppm 

(0, 220/287 mkd, M/F)

Acceptable/guideline

The LOAEL for this supplementary study is 6000 ppm, based on 

effects on clinical signs of toxicity (females), decreased body 

weight (both sexes) and body weight gain (males), changes in 

hematological parameters (males), organ weights (both sexes), 

and histopathology findings (both sexes). Only one dose was 

tested. Increased incidence was observed in thyroid C-cell 

tumours (carcinomas, as well as adenomas and carcinomas 

combined) in males only as well as an increase in the incidence 

of testicular interstitial cell tumours. There was no treatment 

related increase in tumor incidence in females when compared to 

controls.

870.4200b

Carcinogenicity

[mouse]

48542698 (2004)

0,150,500,1500,5000 ppm

(0,15.5/14.3, 54.3/48.1,156/144, 

537/483 mkd, M/F)

Acceptable/guideline

The NOAEL is 1500 ppm (156/144 mg/kg/day in 

males/females); the LOAEL is 5000 ppm (537/483 mg/kg/day in 

males/females) based on increased incidence of diffuse adrenal 

cortical cell vacuolation and increased adrenal wt in males. 

There was no treatment related increase in tumor incidence when 

compared to controls.

870.4200b

Carcinogenicity

[mouse]

49209101 (2013)

0, 6000 ppm

(0,1143/1132 mkd, M/F)

Acceptable/guideline

The LOAEL for this confirmatory study is 10,000 ppm

(1143/1132 mg/kg/day, in males/females), based on clinical 

signs of toxicity, increased adrenal weights, enlarged spleen and 

an increased incidence of extramedullary hematopoiesis in the 

spleen of treated females and an increased incidence of diffuse 
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Table A.2-2. Subchronic, Chronic and Other Toxicity Profile

Guideline Number/ 

Study Type

MRID(s) (year)/ 

Classification/Doses Results

adrenal cortical cell vacuolation and deposition of brown 

pigment in the cortico-medullary junction of the adrenals in both 

sexes.. At the dose tested, there was no treatment-related 

increase in tumor incidence when compared to controls.

870.5100

Gene Mutation

(TA98, TA100, 

TA1535, TA1537 of S. 

typhimurium and WP2 

uvrA E.coli)

48542687 (2001)

Acceptable/guideline

Negative

870.5300

In vitro mammalian cell 

gene mutation test 

(Mouse lymphoma cell)

48542692 (2007)

Acceptable/guideline

Positive (+/- S9)

870.5375

In vitro mammalian 

chromosome aberration 

test (CHL)

48542691 (2011)

48542689 (2003)

Acceptable/guideline

Negative

870.5395

Mammalian bone 

morrow micronucleus 

test

48542694 (2003)

Acceptable/guideline

Negative

870.5550

In vivo, Unscheduled 

DNA synthesis (UDS)

48542695 (2007)

Acceptable/guideline

Negative

870.7485

Metabolism and 

pharmacokinetics

[rat]

48542662,48542661,48542667, 

48542663, 48542665, 48542664, 

48542666, 48542668, 48542825

(2004-2011)

Acceptable/guideline

14C-cyflumetofen is fairly rapidly absorbed and eliminated. The 

test material was fairly well absorbed at the low dose 

(approximately 68-78% of the administered dose), but less so at 

the high dose (approximately 35-46% of the administered dose). 

Saturation of absorption was evident at the high dose, and was 

more pronounced in males than in females. Only low levels of 

radioactivity were retained in tissues up to 72 hours post-dosing, 

with the highest levels observed in the gastrointestinal tract, liver 

and kidneys. The parent compound was extensively metabolized 

following administration of a low dose of 14C-cyflumetofen, but 

poorly metabolized following administration of a high dose. It 

appears as though the parent molecule is metabolized via 

cleavage of the tolyl and phenyl ring structures.

870.7600

Dermal penetration

[rat]

48542724 (2011)

Single dose: 2, 20, 2000 μg/cm2

Acceptable/guideline

Dermal absorption factor (11%)

870.6200

Acute Neurotoxicity -

Rats

48542702 (2010)

0, 125, 500, 2000 mg/kg (gavage)

Acceptable/guideline

The NOAEL is 2000 mg/kg, the highest dose tested. No LOAEL 

was established. 

No evidence of neurotoxicity.

870.6200

Subchronic 

neurotoxicity

[rat]

48542708 (2012)

0, 500, 1500, 5000 ppm 

(0, 30/41, 89/99, 293/353 mkd, 

M/F)

Acceptable/guideline

The systemic NOAEL is 500 ppm (30/41 mg/kg/day in 

males/females). The systemic LOAEL is 1500 ppm (89/99 

mg/kg/day in males/females) based on the increased adrenal 

weights in females and the altered adrenal histopathology of both 

sexes.

No evidence of neurotoxicity at 5000 ppm (HDT).

870.7800

Immunotoxicity

[rat]

48542726 (2011)

0, 500, 1500, or 5000 ppm 

(0, 33, 107, 349 mkd, females 

only)

Acceptable/Guideline

The NOAEL for systemic toxicity is 500 ppm (33 mg/kg/day) in 

female rats. The systemic toxicity LOAEL was 1500 ppm (107 

mg/kg/day) based upon increased adrenal weights and 

correlating histopathology. 

The NOAEL for immunotoxicity is 5000 ppm (349 

mg/kg/day).The immunotoxicity LOAEL was not observed. 
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A.3 Hazard Identification and Endpoint Selection

A.3.1 Acute Reference Dose (aRfD) - General Population and Females Age 13-49

Study Selected: None

Comments: No appropriate endpoint attributable to a single exposure (dose) was identified from 

studies including acute neurotoxicity study and developmental toxicity studies in rats and rabbits. 

An acute reference dose was not established for the general population including infants, 

children, and females age 13-49. In the developmental toxicity study in rabbits, increased 

incidence of paw flexion was observed at 1000 mg/kg/day and was slightly above historical 

controls. Maternal toxicity, decreased fetal body weight, and incomplete ossification were also 

observed at this dose. Paw flexion was considered to be associated with ossification effects (i.e., 

all three pups that exhibited paw flexions also had incomplete ossification). Delays in 

ossification and developmental delays are not typically used to set acute reference doses, 

therefore, paw flexion would not be used as an acute endpoint.

A.3.2 Chronic Reference Dose (cRfD)

Study Selected: Three co-critical studies selected: Combined Chronic Toxicity/Carcinogenicity

Study in Rats, 90-Day Feeding Study in Rats and Two-generation Reproduction Study in Rats.

MRID No: 48542696, 48542697 (chronic toxicity/carcinogenicity rat); 48542682 (90 day

feeding rat); 48542702 (2-generation reproduction study)

Executive Summary: See Appendix A.4.

Dose and Endpoint for Risk Assessment: NOAEL= 16.5 mg/kg/day from both the 90-day and 

chronic toxicity/carcinogenicity toxicity studies in rats. The LOAEL = 30.6 mg/kg/day from the 

2-generation reproduction toxicity study. This parental LOAEL is based on effects on the 

adrenals (increased organ weights and histopathology), which is the target organ.

Uncertainty Factor: 100x (10x interspecies extrapolation, 10x intraspecies variability, 1x FQPA 

Safety Factor)

Comments on Study/Endpoint/Uncertainty Factors: Three studies were selected as cocritical studies for the chronic dietary endpoint. These studies are appropriate for the duration 

and populations of concern since there is no progression of toxicity over time. The NOAEL and 

LOAEL selected were based on the weight of evidence from the three studies which had similar 

target organ toxicities. The point of departure of 16.5 mg/kg/day (NOAEL) was selected from 

the 90-day and the chronic toxicity/carcinogenicity rat studies, which have similar NOAELs and 

LOAELs. The LOAEL of 30.6 mg/kg/day was selected from the 2-generation reproduction 

study. Although a lower NOAEL of 9.2 mg/kg/day was identified in the reproduction study

(LOAEL = 30.6 mg/kg/day) this NOAEL was not selected as the POD for risk assessment since 

it is considered to be a function of calculated compound intake (based on food consumption) 

rather than a lower NOAEL/LOAEL per se. The higher POD of 16.5 mg/kg/day selected is still 

protective of the effects seen at 30.6 mg/kg/day in the 2-generation reproduction toxicity study. 

The POD is also protective of similar effects seen in the 28 day rat study at LOAEL of 75 

mg/kg/day, the chronic mouse study at LOAEL of 537/483 mg/kg/day (M/F), and the chronic 

dog study at LOAEL of 300 mg/kg/day.

Chronic RfD = 

100 ( )

16 .5mg/kg/day

UF

= 0.17 mg/kg/day
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A.3.3 Incidental Oral Exposure (Short- and Intermediate-Term)

Study Selected: Three co-critical studies selected: Combined Chronic/Carcinogenicity Study in 

Rats, 90-Day Feeding Study in Rats and Two-generation Reproduction Study in Rats

MRID No.: 48542696, 48542697 (chronic/carcinogenicity rat); 48542682 (90 day feeding rat); 

48542702 (2-generation reproduction study)

Executive Summary: See Appendix A.4.

Dose and Endpoint for Risk Assessment: NOAEL= 16.5 mg/kg/day from both the 90-day and 

chronic toxicity/carcinogenicity toxicity studies in rats. The LOAEL = 30.6 mg/kg/day from the 

2-generation reproduction toxicity study. This parental LOAEL is based on effects on the 

adrenals (increased organ weights and histopathology), which is the target organ. 

Uncertainty Factor: 100x (10x interspecies extrapolation, 10x intraspecies variability, 1x FQPA 

Safety Factor)

Comments on Study/Endpoint/Uncertainty Factors: There is no incidental oral exposure 

expected based on the current use pattern; however, an endpoint was selected during the full 

review of the database. 

A.3.4 Dermal Exposure (Short-, Intermediate- and Long-Term) 

Study Selected: None

Comments: For short and intermediate-term dermal exposure, no appropriate endpoint was 

identified for risk assessment. A 28-day dermal toxicity study in rats is available; however, no 

adverse effects were seen at the highest dose tested of 1000 mg/kg/day. The endpoints of concern 

(adrenal effects) were also looked at in this study. Although developmental/reproductive effects 

(not assessed in the dermal study) were observed in the developmental and reproductive toxicity

studies, the effects occurred in the presence of parental toxicity. Therefore, since no effects were 

observed in adults at the limit dose, no developmental or reproductive effects would be expected 

to occur due to parental dermal exposure. Risk assessment for short- and intermediate, and longterm dermal exposure is not necessary. 

A.3.5 Inhalation Exposure (Short-, Intermediate- and Long-Term) 

Study Selected: Three co-critical studies selected: Combined Chronic/Carcinogenicity Study in 

Rats, 90-Day Feeding Study in Rats and Two-generation Reproduction Study in Rats

MRID No.: 48542696, 48542697 (chronic/carcinogenicity rat); 48542682 (90 day feeding rat); 

48542702 (2-generation reproduction study)

Executive Summary: See Appendix A.4.

Dose and Endpoint for Risk Assessment: NOAEL= 16.5 mg/kg/day from both the 90-day and 

chronic toxicity/carcinogenicity toxicity studies in rats. The LOAEL = 30.6 mg/kg/day from the 

2-generation reproduction toxicity study. This parental LOAEL is based on effects on the 

adrenals (increased organ weights and histopathology), which is the target organ. 

Uncertainty Factor: 100x (10x interspecies extrapolation, 10x intraspecies variability)

Inhalation Absorption Factor: Equivalent to oral absorption.

Comments on Study/Endpoint/Uncertainty Factors: The HASPOC, based on a WOE 

approach, determined that a subchronic inhalation toxicity study is not needed for cyflumetofen 

at this time (TXR# 0056691). This approach considered all of the available hazard and exposure 

information for cyflumetofen, including: 1) the physical/chemical properties of cyflumetofen 

including its low volatility (4.43 x 10-8 mm Hg at 25 oC); (2) its low acute inhalation toxicity; 

and (3) the use of an oral POD results in MOEs that are ≥5,500, and above the Agency’s level of 
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concern. A route-specific inhalation toxicity study is not available for cyflumetofen, except for 

the acute inhalation toxicity study. Therefore, the oral toxicity study was selected for inhalation 

risk assessments. Three co-critical studies selected: Combined Chronic/Carcinogenicity Study in 

Rats, 90-Day Feeding Study in Rats and Two-generation Reproduction Study in Rats. Since an 

oral NOAEL was selected, the inhalation exposure component (μg ai/day) using 100% 

absorption rate should be converted to an equivalent oral dose (mg/kg/day) in calculating the risk 

for inhalation exposure.
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A.4 Executive Summaries

A.4.1 Subchronic Toxicity

870.3100 28-Day Oral Toxicity - Rat

In a 28-day feeding study (MRID 48542678), OK-5101 (99.3% a.i.) was administered to 6 

Fischer rats/sex/dose in the diet at dose levels of 0, 100, 500, 1000 or 5000 ppm (0, 7.5, 37.6, 

75.1 or 384 mg/kg bw/day in males, 0, 8.05, 40.8, 79.8 or 409 mg/kg bw/day in females) for 28 

days.

Indications of liver dysfunction were exhibited by animals of both sexes in the 5000 ppm group 

and males in the 1000 ppm group with statistically significant decreases in total cholesterol and 

triglyceride, and statistically significant increases in absolute and relative liver weights with 

diffuse hypertrophy of hepatocytes. 

Absolute and relative kidney weights were statistically increased in both males and females of 

the 5000 ppm group. An increase in blood urea nitrogen and potassium observed in the males 

and a decrease in sodium levels in the females further indicate possible kidney dysfunction. 

Gross pathology examinations revealed hypertrophy and white color of the adrenals in all males 

and females in the 5000 ppm group. Absolute and relative adrenal weights were statistically 

increased in these animals. In addition, females in the 1000 ppm group exhibited a statistical 

increase in relative adrenal weight. Histopathological examinations revealed diffuse vacuolation 

of cortical cells in the adrenals in all 1000 and 5000 ppm animals. The vacuolation was 

demonstrated to be lipid deposition. All females in the 1000 and 5000 ppm groups also 

displayed diffuse hypertrophy of cortical cells in the adrenals.

Increases were detected in absolute and relative ovary weights in the 5000 ppm females. 

Histopathological examinations revealed vacuolation of interstitial cells in the ovaries of these 

animals and the same lesions were observed in two 1000 ppm females. Through lipid staining, 

the vacuolation was demonstrated to also be lipid deposition.

The LOAEL is 1000 ppm (75.1 mg/kg bw/day in males, 79.8 mg/kg bw/day in females), 

based on increased adrenal weight and histopathology. The NOAEL is 500 ppm (37.6 

mg/kg bw/day in males, 40.8 mg/kg bw/day in females).

This 28-day toxicity study in the rat is acceptable/nonguideline for a repeat-dose oral study in 

rats. 

870.3100 90-Day Oral Toxicity- Rat

In a subchronic toxicity study (MRID 48542682), OK-5101 (97.6% a.i.) was administered to 10 

Fischer rats/sex/dose in the diet at dose levels of 0, 100, 300, 1000 or 3000 ppm (0, 5.4, 16.5, 

54.5 or 167 mg/kg bw/day in males, 0, 6.28, 19.0, 62.8 or 193 mg/kg bw/day in females) for 90 

days.

Indications of liver effects were seen. OK-5101 caused an increase in prothrombin time in high 
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dose males. In females, increases observed in albumin/globulin ratio in the 1000 and 3000 ppm 

groups were correlated to the decreases in observed globulin levels. Organ examination revealed 

that liver weights were increased in both males and females at the high dose and in the 1000 ppm 

males. 

At necropsy, all females in the 3000 ppm group had white and enlarged adrenals. In addition, 

adrenal weights were increased in the 1000 and 3000 ppm females. Histopathology

examinations found an increase of diffuse vacuolation and diffuse hypertrophy of cortical cells in 

the adrenals of all 1000 and 3000 ppm animals.

Relative kidney weights were increased in high dose males and females. Eight of ten high dose 

females were observed to have vacuolation of interstitial gland cells in their ovaries.

The LOAEL is 1000 ppm (54.5 mg/kg bw/day in males, 62.8 mg/kg bw/day in females) 

based on the hematology and organ weight changes in the liver, organ weight and 

histopathology effects in the adrenals, kidneys and ovaries. The NOAEL is 300 ppm (16.5 

mg/kg bw/day in males, 19.0 mg/kg bw/day in females). 

This subchronic toxicity study in the rat is acceptable/guideline and satisfies the guideline 

requirement for a subchronic oral study (OPPTS 870.3100; OECD 408) in the rat.

870.3100 90-Day Oral Toxicity - Mouse

In a subchronic toxicity study (MRID 48542683), OK-5101 (97.7% a.i.) was administered to 10 

SPR ICR mice/sex/dose in diet at dose levels of 0, 300, 1000, 3000 or 10000 ppm (0, 35.4, 117, 

348 or 1200 mg/kg bw/day in males; 0, 45.0, 150, 447 or 1509 mg/kg bw/day in females) for 90 

days.

Body weight and food consumption were decreased at ≥ 3000 ppm in females. Organ weight 

examinations revealed increased adrenal weights in high dose males. During necropsy, 9 of 10 

male mice in the 10000 ppm exhibited enlarged adrenals. Histopathological findings showed an 

increased incidence of diffuse hypertrophy of cortical cells in males at the 3000 and 10000 ppm 

doses. Two and seven females exhibited diffuse vacuolation of cortical cells in the adrenals at 

3000 and 10000 ppm, respectively. The degree of severity and incidence of the lesion appeared 

in a dose-related manner, indicating a treatment-related effect.

The LOAEL is 3000 ppm (348 mg/kg bw/day in males; 447 mg/kg bw/day in females), 

based on decreased body weights in females, and diffuse hypertrophy and vacuolation of 

cortical cells in the adrenals in both sexes. The NOAEL is 1000 ppm (117 mg/kg bw/day in 

males; 150 mg/kg bw/day in females).

This subchronic toxicity study in the mouse is acceptable/guideline and satisfies the guideline 

requirement for a subchronic oral study (OPPTS 870.3100; OECD 408) in the mouse.

870.3150 90-Day Oral Toxicity - Dog
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In a 90-day dog study (MRID 48542684), OK-5101 (98.4% a.i.) was administered to 4 beagle 

dogs/sex/dose by capsule at dose levels of 0, 30, 300, or 1000 mg/kg bw/day).

All animals survived until study termination. There were no adverse compound related effects 

on clinical signs, hematology, clinical chemistry, urinalysis, or gross pathology. Feces 

containing test substance-like material was observed in mid-and high-dose males and females. 

High-dose males and females exhibited decreased body weights and body weight gains when 

compared to controls. In addition, high dose males had decreased food efficiency and high dose 

females had slightly reduced food consumption. A treatment-related increase in adrenal weights 

was observed in high-dose males. Animals of both sex exhibited vacuolation of the adrenals 

associated with treatment. 

The LOAEL is 1000 mg/kg bw/day, based on decreased body weight and body weight gain, 

increased adrenal weights (males only) and vacuolation of the adrenals. The NOAEL is 300 

mg/kg bw/day.

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

subchronic oral toxicity study in dogs (OPPTS 870.4100; OECD 452). 

870.3200 21/28-Day Dermal Toxicity – Rat

In a repeat-dose dermal toxicity study (MRID 48542686), BAS 9210 I (98.4% a.i.) was applied 

to the shaved skin of 10 Wistar 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.

There were no treatment related adverse effects noted for any parameter examined in this study. 

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

This dermal toxicity study in the rat is acceptable/guideline and satisfies the guideline 

requirement for a repeat-dose dermal toxicity study (OPPTS 870.3200, OECD 410) in the rat. 

870.3465 90-Day Inhalation – Rat

No study was conducted.

A.4.2 Prenatal Developmental Toxicity

870.3700a Prenatal Developmental Toxicity Study - Rat

In a developmental toxicity study (MRID 48542704), OK-5101 Technical (97.67 % a.i.) was 

administered to 25 female Wistar rats/dose via gavage at dose levels of 0, 50, 250 or 1000 mg/kg 

bw/day from days 6 through 19 of gestation. 

All animals survived to scheduled termination. Slight decreases in body weight gain and food 

consumption throughout the treatment period were associated with a decrease in corrected 
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overall body weight gain (GD 6-20 and GD 0-20) at 1000 mg/kg bw/day. Absolute left adrenal 

gland weight and organ to body weight ratio were increased in the mid (p≤ 0.05) and high (p 

≤0.01) doses, while the absolute right adrenal gland weight and organ to body weight ratio were 

increased in the high dose only (p ≤0.01). An increase in the incidence of slight diffuse 

hypertrophy of the cortical cells of both adrenal glands was noted in the high dose group. The 

incidence of slight or moderate bilateral diffuse cytoplasmic vacuolation of the cortical cells was 

also increased in the high dose group when compared to controls. 

The maternal LOAEL is 250 mg/kg bw/day, based on an increase in adrenal weights and 

organ to body weight ratio. The maternal NOAEL is 50 mg/kg bw/day. 

An increased incidence of wavy ribs was noted at 1000 mg/kg/day, while an increased incidence 

of incompletely ossified sternal centra was observed at the 250 and 1000 mg/kg bw/day dose 

levels. There were no additional treatment related effects on developmental parameters. 

The developmental LOAEL is 250 mg/kg bw/day, based on an increased incidence of 

incompletely ossified sternal centra. The developmental NOAEL is 50 mg/kg bw/day.

The developmental toxicity study in the rat is classified acceptable/guideline and satisfies the 

guideline requirement for a developmental toxicity study (OPPTS 870.3700; OECD 414) in the 

rat.

870.3700b Prenatal Developmental Toxicity Study - Rabbit

In a developmental toxicity study (MRID 48542706), OK-5101 Technical (97.67 % a.i.) was 

administered to 25 female New Zealand White rabbits/dose by gavage at dose levels of 0, 50, 

250, or 1000 mg/kg bw/day from days 6 through 28 of gestation. 

There were no deaths attributed to the test substance. Body weight gains were generally slightly

reduced at 250 and 1000 mg/kg bw/day, with a resulting decrease in overall body weight gain 

and corrected body weight gain when compared to controls. Food consumption was generally

decreased at 1000 mg/kg bw/day, resulting in decreased overall food consumption in this group 

during the treatment period. Absolute liver weights were decreased in the mid- and high-dose 

groups and absolute weights of the left and right adrenals were decreased in the high dose group 

only. In the absence of body weight decrements, decreases in body weight gain (35-53%), food 

consumption and liver weights (marginal decrease of 8%) at the limit dose are not considered 

adverse effects. As a result, no treatment related maternal adverse effects were observed. This is 

consistent with the range finding study where no maternal toxicity was observed. 

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

There were no abortions or premature deliveries. No effects of treatment were noted on numbers 

of litters, live or dead fetuses, corpora lutea, early or late resorptions, sex ratio, or pre- or postimplantation loss. Male, female and combined fetal body weights and combined placental 

weights were significantly reduced in the 1000 mg/kg bw/day dose group. The 250 and 1000 

mg/kg bw/day dose groups exhibited increased incidences in the average number of ossified 
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pairs of ribs and thoracic vertebrae, with a concomitant decrease in the average number of 

ossified lumbar vertebrae when compared to controls. The numbers of ossified xiphoid were 

also significantly decreased in these dose groups. Litter and fetal incidences of angulated hyoid 

and incompletely ossified sternal centra were increased in the 1000 mg/kg bw/day dose group. 

Low incidence of ossification effects at 250 mg/kg/day were not considered an adverse effect.

The only malformation attributable to treatment was a downward flexion of the forepaws (2

fetuses in one litter) and hind paws (1 fetus in one litter) in the high dose group. The incidence of 

downward paw flexion (litter incidence: 8%; fetal incidence: 1.4%) in the 1000 mg/kg/day group 

was slightly above historical controls (litter incidence: 0-5.3%; fetal incidence: 0-0.6%) and was 

considered treatment-related adverse effect. 

The developmental NOAEL is 250 mg/kg/day; and the LOAEL is 1000 mg/kg/day based on 

increased incidences of ossification and paw flexion; and decreased fetal body weight. 

The developmental toxicity study in the rabbit is classified acceptable/guideline and satisfies the 

guideline requirement for a developmental toxicity study (OPPTS 870.3700; OECD 414) in the 

rabbit.

A.4.3 Reproductive Toxicity

870.3800 Reproduction and Fertility Effects - Rat

In a 2-generation reproduction study, OK-5101 (97.67% a.i.) was administered to 24 Wistar 

rats/sex/dose in the diet at dose levels of 0, 150, 500 or 1500 ppm (0, 9.21/13.8, 30.6/46.6, or 

89.4/141.1 mg/kg bw/day in males/females). P and F1 male and female parental animals were 

administered test or control diet for 10 weeks prior to mating, throughout mating, gestation and 

lactation, and until necropsy. A single litter was produced by each generation. Serum LH, FSH, 

testosterone (males only), progesterone (females only) and 17 ß-estradiol (females only) 

hormone assays were conducted using blood samples collected from 10 surviving F1 adult 

animals/sex/dose at necropsy.

There were no treatment-related effects on parental animals of either generation for clinical signs 

of toxicity, mortality or food consumption. There were no changes in body weight/body weight 

gain observed in any male parental animal. At 1500 ppm, parental females exhibited a decrease 

in body weight gain during pre-mating weeks 1-2 (F1 generation) or 6-8 (P generation). 

Absolute and relative adrenal weights were increased in P and F1 parental females at 500 ppm 

and above. In parental males at 1500 ppm, absolute and relative adrenal weights were increased 

in the P and F1 generations. In addition, absolute and relative ovary weights were increased in P 

generation females at 1500 ppm only. Following macroscopic examination, male and female 

parental animals of both generations exhibited white and/or enlarged adrenals at 1500 ppm. 

Histopathological examination of the adrenals revealed an increased incidence of hypertrophy of 

the zona glomerulosa cells at 500 ppm and above in P generation females and F1 generation 

males and females and in P males at 1500 ppm. Additionally in the adrenals, an increased 

incidence of vacuolation of the zona fasciculata cells was observed at 1500 ppm in P generation 

females and in both sexes of the F1 generation. An increased incidence of vacuolation of the 

interstitial cells of the ovary was also noted at 1500 ppm in F1 females. 
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The parental LOAEL is 500 ppm (30.6/46.6 mg/kg bw/day in males/females) based on 

effects on the adrenals (increased organ weights and histopathology). The parental NOAEL 

is 150 ppm (9.21/13.8 mg/kg bw/day in males/females).

There were no treatment-related effects observed on ovarian follicle counts, sperm measurements 

or reproductive performance. An increase in estrous cycle length was noted at 1500 ppm. 

However, the estrous cycle length is within the range of the historical controls and would not be 

considered an adverse effect. In addition, decreased FSH levels were noted at 500 and 1500 ppm 

and decreased progesterone was noted at 150 ppm and above in F1 females. Hormone changes 

are considered a reproductive effect. A dose response was observed with three hormones 

affected at the highest dose (1500 ppm) and two hormones affected at 500 ppm.

The reproductive NOAEL in females is 150 ppm (13.8 mg/kg/day); and the LOAEL in 

females is 500 ppm (46.6 mg/kg/day) based on hormone changes (significantly decreased 

FSH and progesterone levels). The reproductive LOAEL is not determined in males. The 

reproductive NOAEL in males is ≥1500 ppm (89.4 mg/kg bw/day). 

In the offspring, there were no treatment-related effects on clinical signs of toxicity, viability and 

measured anogenital distances. At 1500 ppm, body weights were decreased in male and female 

pups of the F2 generation during LD 7-21. Absolute and relative adrenal weights were increased 

at 500 ppm and above in both sexes of both generations of offspring. An increased incidence of 

adrenals that were white in color was observed in both sexes of F2 pups at 1500 ppm. 

Microscopic examination of the adrenals revealed an increased incidence of hypertrophy of the 

zona glomerulosa cells in both generations of males at 500 ppm and above and in both 

generations of females at 1500 ppm. Additionally in the adrenals, an increased incidence of 

hypertrophy of the zona fasciculata cells was noted at 500 ppm and above in F1 males and 

females and F2 males, and at 1500 ppm in F2 females. Delayed sexual maturation was observed 

in females (increased time to vaginal opening) at 500 ppm and above, and in males (increased 

time to preputial separation) at 1500 ppm. However, slight delay of sexual maturation at 500 

ppm (approximately 1 day relative to the control group) would not be considered an adverse 

effect

The offspring LOAEL is 500 ppm (30.6/46.6 mg/kg bw/day in males/females) based on 

effects on the adrenals (increased organ weights and histopathology) in both sexes. The 

offspring NOAEL is 150 ppm (9.21/13.8 mg/kg bw/day in males/females).

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

reproductive study (OPPTS 870.3800); OECD 416 in the rat.

A.4.4 Chronic Toxicity

870.4100a (870.4300) Chronic Toxicity – Rat

In a chronic toxicity study (MRID 48542696), OK-5101 (97.67% cyflumetofen) was 

administered to Fischer (F344/DuCrj) rats (50/sex/dose) in the diet at dose levels of 0, 50, 150, 
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500 or 1500 ppm (equivalent to 0/0, 1.90/2.31, 5.63/6.92, 18.8/23.3 or 56.8/69.2 mg/kg bw/day

in males/females, respectively) for one year. Interim sacrifices (10/sex/dose) were performed at 

4, 13 and 26 weeks. All remaining animals were sacrificed at 52 weeks.

There were no adverse treatment-related effects on mortality, clinical signs, body weight, food 

consumption, hematology, clinical chemistry and urinalysis parameters. Treatment related 

effects were noted in the adrenals of both sexes at the high dose. In females, absolute and 

relative adrenal weights were increased at all scheduled sacrifices, along with diffuse 

hypertrophy of adrenal cortical cells. Effects in males were slightly different with diffuse 

vacuolation of the cortical cells recorded at all interim and terminal sacrifices. An increased 

incidence of vacuolation of ovarian interstitial gland cells was observed in high dose females 

from week 13 on, along with increased ovarian weights at terminal sacrifice. An increased 

incidence of atrophy of the seminal vesicles and coagulating gland were recorded in high dose 

males at terminal sacrifice only. There were no corresponding effects observed during 

histopathological examination. 

The LOAEL for chronic administration of cyflumetofen in rats is 1500 ppm (equivalent to 

56.8/69.2 in males/females, respectively) based on diffuse vacuolation of adrenal cortical 

cells and increased incidence of atrophy of the seminal vesicles and coagulating glands in 

males and increased adrenal weights and ovarian weights, diffuse hypertrophy of adrenal 

cortical cells and vacuolation of the ovarian interstitial gland cells in females. The NOAEL 

is 500 ppm (equivalent to 18.8/23.3 mg/kg bw/day in males/females, respectively). 

This chronic study in the rat is acceptable/guideline and satisfies the guideline requirement for a 

chronic oral study (OPPTS 870.4100), OECD 452 in the rat.

870.4100a (870.4300) Chronic Toxicity – Rat

In a supplemental chronic toxicity study (MRID 49029701), OK-5101 (cyflumetofen, 97.82 % 

a.i.) was administered to SPF/VAF Fischer rats (F344/DuCrj) (50/sex/dose) in the diet at dose 

levels of 0 or 6000 ppm (0 or 250/319 mg/kg bw/day in males/females) for 52 weeks. Interim 

sacrifices (10/sex/dose) were performed at 4, 13, 26 weeks. All remaining animals were 

sacrificed at 52 weeks. 

There were no treatment-related deaths or effects on food consumption, food efficiency, or in the 

ophthalmologic assessment. In treated females, an increased incidence of soiled fur around the 

external genital area and a consistent decrease in body weight and body weight gain when 

compared to the control group were observed throughout most of the study. Males of the 6000 

ppm group had reduced body weight gain throughout the study. In treated animals of both sexes, 

affected hematological parameters included decreased platelet count and fibrinogen 

concentration and elongated prothrombin time and activated partial thromboplastin time (APTT). 

Blood urea nitrogen (BUN) was elevated from 26 and 52 week in males and at all sampling 

points in females and was slightly outside of the submitted historical control data range for the 

females. This observation was considered treatment-related in conjunction with increased kidney

weights for the treated animals. In both sexes at 6000 ppm, absolute and relative liver, kidney

and adrenal weights were increased at all sacrifice time points. Gross necropsy revealed an 
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increase in the incidence of white colour in the adrenal gland in both sexes at 6000 ppm as well 

as adrenal enlargement in females. Treatment-related histological observations included effects

noted in the adrenal gland such as diffuse hypertrophy of the cortical cell in treated females and 

diffuse cortical cell vacuolation in treated males and focal vacuolation of the cortical cell in 

treated females with higher incidence of these lesions by the end of the study. In treated males, 

gross lesions in the testis such as atrophy, softening, and spots were observed as well as an 

increased incidence of interstitial cell hyperplasia. Atrophy of the acinar cell of the pancreas was 

also noted in the treated males. In treated females, vacuolation of the interstitial gland cell of the 

ovary was observed. 

In this supplemental study, the LOAEL was 6000 ppm (250/319 mg/kg bw/day in

males/females) based on increased adrenal weights accompanied by gross pathology and 

histopathology lesions noted in both sexes, vacuolation of the interstitial gland cell of the 

ovary and hyperplasia of the interstitial cell of the testes. A NOAEL was not set.

This chronic study in the rat is supplemental; however, when considered in conjunction with the 

previous study (MRID 48542696), it satisfies the guideline requirement for a chronic toxicity

study (OPPTS 870.4100), OECD 452 in rats. 

870.4100b Chronic Toxicity - Dog

In a 1-year dog study (MRID 48542685), OK-5101 (cyflumetofen, 98.4% a.i.) was administered 

to 4 beagle dogs/sex/dose by capsule at dose levels of 0, 30, 300, or 1000 mg/kg bw/day for one

year.

There were no compound related effects on mortality, body weight, body weight gain, food 

consumption, urinalysis, hematology, clinical chemistry, or ophthalmoscopy. Feces containing 

test substance-like material was observed in both sexes at the mid-and high-dose levels. Highdose males exhibited a treatment related increase in vomiting and soft/mucous/watery feces. 

High-dose animals of both sexes exhibited decreased triglycerides. Increased absolute and 

relative adrenal weights were noted in both sexes at the high dose. In the adrenals, treatment 

related vacuolation, cortical degeneration, fibrosis, cell infiltration and pigmented macrophages 

(males only) were observed to some extent in mid- and high-dose males and females. In addition, 

high-dose females exhibited enlarged adrenals. 

The LOAEL is 300 mg/kg bw/day, based on adrenal cortical cell vacuolation and additional 

adrenal histopathology findings. The NOAEL is 30 mg/kg bw/day.

This study in dogs is acceptable/guideline and satisfies the guideline requirement for a 1-year 

oral toxicity study in dogs (OPPTS 870.4100; OECD 452).

A.4.5 Carcinogenicity

870.4200a Carcinogenicity - Rat

In a carcinogenicity study (MRID 48542697), OK-5101(cyflumetofen, 97.67 % a.i.) was 
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administered to 50 Fischer rats/sex/dose in the diet at dose levels of 0, 150, 500, or 1500 ppm (0, 

4.92/6.14, 16.5/20.3, 49.5/61.9 mg/kg bw/day in males/females) for 104 weeks.

There were no compound related effects on mortality, clinical signs, body weight, food 

consumption, hematology or gross necropsy observations. Diffuse hypertrophy of the adrenal 

cortex was noted in high dose males and females in conjunction with increased adrenal weights. 

In addition, luminal dilatation of the gland of the uterine horn was observed in high dose 

females. At the doses tested, there was no treatment related increase in tumor incidence when 

compared to controls. 

The LOAEL is 1500 ppm (49.5/61.9 mg/kg/day for males and females) based on increased 

adrenal weights, hyperplasia and hypertrophy of the adrenal cortex in both sexes, and 

luminal dilatation of the gland in the uterine horn in females. The NOAEL is 500ppm 

(16.5/20.3 mg/kgkday for males and females). There was no treatment related increase in 

tumor incidence when compared to controls.

This carcinogenicity study in the rat is considered acceptable/guideline and satisfies the guideline 

requirement for a carcinogenicity study (OPPTS 870.4200); OECD 451 in the rat.

870.4200a Carcinogenicity (Supplementary) - Rat

In a supplemental carcinogenicity study, BAS 9210 I (cyflumetofen, 97.82 % a.i.) was 

administered to 50 Fischer rats (F344/DuCrlCrlj)/sex/dose in the diet at dose levels of 0 or 6000

ppm (0, 220/287 mg/kg bw/day in males/females) for 104 weeks.

There was no treatment-related effect on mortality and food consumption. Treated females 

exhibited an increased incidence of tactile hair loss and soiled fur. Males showed no clinical 

signs of toxicity. Treated males exhibited decreased final body weight and overall body weight 

gain, while treated females exhibited decreased body weight intermittently throughout the study 

period. Decreased differential leukocyte count was observed in treated males but was unaffected 

in females. Absolute and/or relative weights of the kidneys, liver, and adrenals in both sexes as 

well as testis weights in treated males and ovary weights in treated females were affected by 

treatment. Although clinical chemistry and hematological parameters were not assessed in the 

current study, effects were noted on these parameters in the confirmatory 1-year rat chronic 

toxicity study (MRID# 49029701) and were considered as corroborating findings in support of 

the organ weight changes in the current study. Incidences of diffuse hypertrophy and focal 

vacuolation (both sexes) and diffuse vacuolation (females only) were increased in the adrenal 

cortical gland cells. An increased incidence of focal atrophy of the pancreatic acinar cells was 

noted in treated males of the current study and was also observed in treated males in the 

confirmatory 1-year rat chronic toxicity study. At necropsy, increased incidences of atrophy of 

the epididymis and masses in the testis were observed in treated males. There was a treatment 

related increase in the incidence of Leydig cell tumours in male rats when compared to controls. 

Corresponding decreased incidences of softening of the testis, seminiferous tubule atrophy, and 

testicular interstitial cell hyperplasia were considered to be secondary to the development of 

testicular interstitial cell tumours in treated male rats. In addition, treated males exhibited an 

increase in the incidence of thyroid C-cell tumours (combined adenomas and carcinomas). 
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The LOAEL for this supplementary study is 6000 ppm (220/287 mg/kg bw/day in 

males/females), based on effects on clinical signs of toxicity (females), decreased body 

weight (both sexes) and body weight gain (males), changes in hematological parameters 

(males), organ weights (both sexes), and histopathology findings (both sexes). A NOAEL 

was not identified for this study. 

Treatment with cyflumetofen was associated with an increase in thyroid C-cell tumours 

(carcinomas, as well as adenomas and carcinomas combined) in males as well as an 

increase in the incidence of testicular interstitial cell tumours. There was no treatment 

related increase in tumor incidence in females when compared to controls.

This carcinogenicity study in the rat is supplemental; however, when considered in conjunction 

with the previous study (MRID# 48542697), it satisfies the guideline requirement for a 

carcinogenicity study (OPPTS 870.4200); OECD 451 in rats.

870.4200b Carcinogenicity - Mouse

In a carcinogenicity study (MRID 48542698), OK-5101(cyflumetofen, 97.67 % a.i.) was 

administered to 52 CD-1 mice/sex/dose in the diet at dose levels of 0, 150, 500, 1500 or 5000

ppm (0, 15.5/14.3, 54.3/48.1, 156/144, 537/483 mg/kg bw/day in males/females) for 78 weeks. 

There were no compound-related effects on mortality, clinical signs, body weight, food 

consumption, hematology or gross necropsy observations at any dose level. Diffuse adrenal 

cortical cell vacuolation was noted in 5000 ppm males and females, with a corresponding 

increase in adrenal weight in males. At the doses tested, there has no treatment related increase in 

tumor incidence when compared to controls.

The LOAEL is 5000 ppm, based on an increased incidence of diffuse adrenal cortical cell 

vacuolation in males and females, and an increase in adrenal weight in males. The NOAEL 

is 1500 ppm. There was no treatment related increase in tumor incidences when compared 

to controls.

This carcinogenicity study in the mouse is acceptable/guideline and satisfies the guideline 

requirement for a carcinogenicity study (OPPTS 870.4200); OECD 451 in mice. 

870.4200b Carcinogenicity (Supplementary) - Mouse

In a supplemental carcinogenicity study (MRID 49209101), BAS 9210 I (cyflumetofen, 97.82 % 

a.i.) was administered to SPF ICR (Crj:CD1) mice (52/sex/dose) in the diet at dose levels of 0 or 

10,000 ppm (0, 1143/1132 mg/kg bw/day in males/females) for 78 weeks.

There were no compound-related effects on mortality, body weight, food consumption, or 

hematology parameters at the dose tested. Diffuse adrenal cortical cell vacuolation and 

deposition of brown pigment in the cortico-medullary junction of the adrenals was observed in 

treated animals of both sexes. Treated females exhibited a significant increase in the incidence 

of pale-colored skin and pale-colored eye/eyelid, increased adrenal weights, enlarged spleen and 
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an increased incidence of extramedullary hematopoiesis in the spleen. 

The LOAEL for this confirmatory study is 10,000 ppm, based on clinical signs of toxicity, 

increased adrenal weights, enlarged spleen and an increased incidence of extramedullary 

hematopoiesis in the spleen of treated females and an increased incidence of diffuse adrenal 

cortical cell vacuolation and deposition of brown pigment in the cortico-medullary junction 

of the adrenals in both sexes. A NOAEL was not identified for this study.

At the dose tested, there was no treatment-related increase in tumor incidence when 

compared to controls. Dosing was considered adequate as animals were dosed above the 

limit dose of 1000 mg/kg bw/day.

This carcinogenicity study in the mouse is supplemental; however, when considered in 

conjunction with the previous study (MRID 48542698), it satisfies the guideline requirement for 

a carcinogenicity study (OPPTS 870.4200); OECD 451 in mice.

A.4.6 Mutagenicity

Cyflumetofen, two metabolites (B-1 and B-3) and one impurity (AB-13) were evaluated in a 

comprehensive battery of Genetic Toxicology assays. The data indicate that neither the parent 

compound nor metabolite B-1 were mutagenic in bacteria. However, metabolite B-3 induced a 

weak but reproducible and concentration-related mutagenic response (1.7- 2.2 fold increases at 

3330 and 5000 μg/plate) in Salmonella typhimurium TA100; the effect was, nevertheless, 

abolished in the presence of exogenous metabolic activation. There was also evidence of a 

mutagenic response in the L5178Y mouse lymphoma assay that was induced by the parent and 

the two metabolites. The response was the strongest in the parent compound (90 μg/mL –S9 vs. 

the limit concentration for the two metabolites). However, for both the parent and metabolite B1, mutagenic activity was only seen at severely cytotoxic concentration (i.e., ≈10% survival); 

consequently, these results are not considered sufficient evidence of a mutagenic response in this 

test system. For metabolite B-3, the 4.3-fold increase in the mutation frequency at 1891 μg/mL

(equivalent to the limit concentration of 10 mM) was confined to this level and not observed in 

the S9-activated portion of the assay. 

For the remaining genetic endpoints, the parent and the two metabolites were not clastogenic in 

Chinese hamster lung cells (parent in two studies performed by independent laboratories) or 

peripheral human lymphocytes (metabolites B-1 and B-3). Similarly, cyflumetofen was not 

clastogenic or aneugenic in mouse bone marrow cells up to the limit dose. Finally, neither the 

parent nor the two metabolites induced a genotoxic response in hepatocytes harvest from male 

rats orally exposed up to the limit dose (parent and metabolite B-1) or an overtly toxic level for 

the test animals (metabolite B-3). 

Studies performed on an impurity of cyflumetofen (AB-13) showed negative results for reverse 

gene mutations in bacteria (S. typhimurium TA 1535, TA 1537, TA 98 or TA 100 or Escherichia 

coli WP2 uvrA), forward gene mutations in mammalian cells (L5178Y mouse lymphoma cells), 

and chromosome aberrations in mammalian cells (human peripheral lymphocytes).
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Overall, the data indicate that while there was some evidence of a mutagenic response from in 

vitro assays, the responses were confined to severely cytotoxic concentrations, abolished in the 

presence of exogenous metabolic activation, or were not expressed in whole animal studies. 

Based on these considerations, there is no concern for mutagenicity for the parent or the 

metabolites. Similarly, the impurity was uniformly negative; hence, there is also no concern for 

mutagenicity. All assays were well-conducted, acceptable and satisfy FIFRA test guidelines for 

mutagenicity testing. Consequently, mutagenicity can be ruled out as a possible mode of action 

for tumor formation. Results from these assays are summarized below: 

Parent 

Cyflumetofen was negative in bacteria in two independent trials using the pre-incubation method 

at concentrations of 20.6 to 5000 μg/plate +/-S9 (MRID 48542687).

In the mouse lymphoma forward gene mutation assay, concentrations of 20 to 90 μg/mL –S9 or 

10 to 140 μg/mL +S9 for 3 hours. Although increases in the total mutation frequencies (MF) 

occurred at 90 μg/mL –S9 (3.2-fold) and at 140 μg/mL +S9 (6.1-fold), these concentrations were 

insoluble and severely cytotoxic (relative suspension growth (RSG) was 10% at 90 μg/mL –S9 

and 12% at 140 μg/mL +S9). These results are, therefore, not considered sufficient evidence of a 

mutagenic response in this test system (MRID 48542692).

In an in vitro chromosome aberration study, Chinese hamster lung fibroblasts (V79) cells were 

exposed to 6.25 to 50 μg/mL –S9 and 25 to 200 μg/mL +S9 for 6 hours and allowed an 18-hour 

recovery period. Cells were also continuously treated with 3.75 to 30 μg/mL –S9 for 24 or 48 

hours and harvested at the end of treatment. Compound precipitation was seen at ≥200 μg/mL 

+S9. Less than 50% of the cells were available for analysis at the highest dose tested with or 

without S9 activation. There were however, and no significant increases in cells with structural 

or numerical chromosome aberrations (MRID 48542689).

In a second in vitro chromosome aberration study, Chinese hamster lung fibroblasts (V79) cells 

were exposed to 2.5 to 80 μg/mL –S9 and 10 to 160 μg/mL +S9 for 4 hours and allowed a 14-

hour recovery period. Due to severe cytotoxicity, the assay was repeated with 3.1 to 10 μg/mL –

S9. Cells were also continuously treated with 3.1 to 40 μg/mL –S9 for 18 hours and harvested or 

allowed an additional 10 hour recovery. With S9, cells were dosed with 20-320 μg/mL for 4 

hours and harvested after a 24-hour recovery period. Compound precipitation was seen at ≥120 

μg/mL. Less than 50% of the cells were available for analysis at ≥160 μg/mL +S9, ≥20 μg/mLS9 (18-hour exposure), or 40 μg/mL-S9 (18-hour exposure with 10-hour recovery). There were 

however, and no significant increases in cells with structural or numerical chromosome 

aberrations (MRID 48542691). 

In the mouse bone marrow micronucleus assay, levels up to the limit dose were not overtly toxic 

to the test animals, cytotoxic to the target cells or induce an aneugenic or a clastogenic response 

(MRID 48542694). 
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In an in vivo unscheduled DNA synthesis (UDS) assay in male Wistar rats, metabolite B-1 was 

not overtly toxic to the test animals or genotoxic in the hepatocytes harvested 2-4 or 12-16 hours 

after oral administration of levels up to the limit dose of 2000 mg/kg (MRID 48542695).

Metabolite B-1

Metabolite B-1 was negative in bacteria in two independent trials using the plate incorporation 

method at concentrations of 3 to 5000 μg/plate +/-S9 (MRID 48542710).

In the mouse lymphoma forward gene mutation assay, concentrations of 1 to 1901 μg/mL +/–S9 

(1901 μg/mL is equivalent to the limit concentration of 10 mM) were tested using a 3-hour 

exposure. A second assay was performed with comparable nonactivated concentrations and a 

24-hour exposure and S9-activated levels of 3-1910 μg/mL with a 3-hour exposure. The 

nonactivated assay was repeated for the 24-hour exposure with 3- 1910 μg/mL. The 3-hour 

exposure with or without S9 activation was negative up to the highest dose tested (HDT). 

Although marked increases in the total MF occurred at the HDT without S9 activation after the 

24-hour treatment in both the initial (8.2-fold) and repeat trials (7-fold), these concentrations 

were severely cytotoxic (RSG was 13 or 9%, respectively). Consequently, these results are not 

considered sufficient evidence of a mutagenic response in this test system (MRID 48542712). 

In an in vitro chromosome aberration study, peripheral human lymphocytes were exposed to 333 

to 1901 μg/mL +/–S9 (1901 μg/mL is equivalent to the limit concentration of 10 mM) for 3 

hours and allowed a 21-hour recovery period. Cells were also continuously treated with 100 to 

1000 μg/mL –S9 for 24 or 48 hours and harvested at the end of exposure. With S9, cells were 

dosed with 333-1901 μg/mL for 3 hours and harvested after 48 hours. There were no significant 

increases in cells with structural chromosome aberrations without S9 activation up to 

concentrations that caused a ≥50% decrease in relative suspension growth (≥ 750 μg/mL, 

prolonged 24-hour exposure or (≥ 560 μg/mL, prolonged 48-hour exposure). Similarly, no 

evidence of a clastogenic response was seen after exposure for 3 hours with or with S9 up to the 

limit dose (MRID 48542711).

In an in vivo unscheduled DNA synthesis (UDS) assay in male Wistar rats, metabolite B-1 was 

not overtly toxic to the test animals or genotoxic in the hepatocytes harvested 2-4 or 12-16 hours 

after oral administration of levels up to the limit dose of 2000 mg/kg (MRID 48542713).

Metabolite B-3 [2-(trifluoromethyl)benzamide]

Metabolite-3 induced a reproducible and dose-related increase in mutant colonies of Salmonella 

typhimurium TA100. Fold increases were 1.7 and 1.9-fold at 3330 and 5000 μg/plate –S9 in 

Trial 1 and 1.7 and 2.2-fold at 3330 and 5000 μg/plate –S9 in Trial 2. The response was, 

however, abolished in the presence of S9 activation and was not seen in any other Salmonella

strain or in Escherichia coli WP2 uvrA (MRID 48542715).

In the mouse lymphoma forward gene mutation assay, concentrations of 1 to 1891 μg/mL +/–S9 

(1891 μg/mL is equivalent to the limit concentration of 10 mM) were tested using a 3-hour 

exposure. A second assay was performed with comparable nonactivated concentrations and a 
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24-hour exposure and comparable S9-activated concentrations with a 3-hour exposure. The 3-

hour exposure with or without S9 activation was negative up to the highest dose tested (HDT). 

A marked increase in the total MF occurred at the HDT without S9 activation (4.3-fold) 

following the prolonged and in the absence of severe cytotoxicity. However, the response was 

confined to this concentration and not observed when S9 activation was incorporated into the 

reaction mixture (MRID 48542717). 

In an in vitro chromosome aberration study, peripheral human lymphocytes were exposed to 333 

to 1891 μg/mL +/–S9 (1891 μg/mL is equivalent to the limit concentration of 10 mM) for 3 

hours and allowed a 21-hour recovery period. Cells were also continuously treated with 100 to 

1891 μg/mL –S9 for 24 hours or 33 to 1891 μg/mL –S9 for 48 hours. Cells were harvested at 

the end of the prolonged exposures. With S9, cells were dosed with 333-1891 μg/mL for 3 hours 

and harvested after 48 hours. There were no significant increases in cells with structural 

chromosome aberrations with or without S9 up to the limit concentrations (MRID 48542716).

In an in vivo unscheduled DNA synthesis (UDS) assay in male Wistar rats, metabolite B-3 was 

toxic to the test animals at 350 mg/kg but was not genotoxic in the hepatocytes harvested 2-4 or 

12-16 hours after oral administration of 0, 175 or 350 mg/kg (MRID 48542718).

Impurity AB-13

Impurity AB-13 was negative in bacteria in two independent trials using the plate incorporation 

method up to insoluble concentrations (≥333 μg/plate +/-S9) (MRID 48542688).

In the mouse lymphoma forward gene mutation assay, concentrations of 0.03 to 100 μg/mL +/–

S9 were tested using a 3-hour exposure. A second assay was performed with similar 

concentrations and a 24-hour exposure for the nonactivated phase of testing and with a 3-hour 

exposure for the S9-activated concentrations. The 3-hour exposure with or without S9 activation 

was negative up to the highest dose tested. Compound precipitation was seen at 100 μg/mL +/–

S9. RSG was generally similar to the control at all concentrations and exposure intervals. There 

was no appreciable increase in the MF at any nonactivated or S9-activated concentration (MRID 

48849413). 

In an in vitro chromosome aberration study, peripheral human lymphocytes were exposed 

continuously to 10 to 333 μg/mL –S9 for 24 or 48 hours and harvested at the end of the 

prolonged exposures. With S9, cells were dosed with 10 to 333 μg/mL for 3 hours and harvested 

after 48 hours. Compound precipitation was noted at ≥100 μg/mL. There were no adverse 

effects on the mitotic indices or significant increases in cells with structural chromosome 

aberrations with or without S9 up to insoluble levels (MRID 48542716690).

A.4.7 Neurotoxicity

870.6200 Acute Neurotoxicity Screening Battery- Rat 

In an acute neurotoxicity study (MRID 48542707), groups of young adult Wistar rats (10/sex) 

were given a single gavage dose of BAS 9210 I (97.08% a.i.) in 1% carboxymethylcellulose at 

doses of 0, 125, 500, 2000 mg/kg bw. Rats were observed for 14 days. 
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Neurobehavioral assessments (functional observation battery and motor activity testing) were 

performed in 10 animals/sex/group 7 days before dosing, the day of dosing, and 7 and 14 days 

post-dosing. At study termination, 5 animals/sex/group were euthanized and perfused for 

neuropathological examination. Of the perfused animals, 5/sex from the control and high dose 

groups were subjected to histopathological evaluation of brain and peripheral nervous system

tissues. Brains weights were taken for 5 animals/sex/group.

No treatment-related effects were noted on mortality, clinical signs, body weight, brain weight, 

gross pathology or histologic neuropathology. FOB and motor activity testing revealed no 

treatment-related effects. 

The NOAEL is 2000 mg/kg bw, the highest dose tested. No LOAEL was established. No 

evidence of neurotoxicity.

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

870.6200 Subchronic Neurotoxicity Screening Battery -Rat

In a subchronic neurotoxicity study (MRID 48542708), BAS 9210 I (97.08% cyflumtofen) was 

administered to 10 Wistar rats/sex/group in the diet for 91 days at doses of 0, 500, 1500, and 

5000 ppm (equivalent to 0/0, 30/41, 89/99, and 293/353 mg/kg bw in males/females). 

Neurobehavioral assessments (functional observation battery and motor activity testing) were 

performed in all animals one week before dosing commenced and also 1, 22, 50, and 85 days 

after the start of dosing. At study termination, 5 animals/sex/group were euthanized and perfused 

for neuropathological examination and the brain weights of these animals were measured. Of the 

perfused animals, only the control and high dose groups were subjected to histopathological 

evaluation of brain and peripheral nervous system tissues. The remaining 5 animals/sex/group 

were sacrificed by decapitation, subjected to gross necropsy, and the adrenal gland of each 

animal was weighed and examined microscopically. Body weights and food consumption for all 

animals on study were measured weekly.

There were no treatment related effects on mortality, clinical signs, body weight, food 

consumption, brain weight or neuropathology. Food consumption was elevated in 500 ppm 

females, and these animals also exhibited increased body weights and body weight gains. 

Consequently, due to the increased body weights, absolute brain weights were elevated in 500 

ppm females while relative brain weights remained comparable to controls. Since these findings 

were restricted to the low dose and no dose-response was observed, increased food consumption, 

body weight, and the corresponding increase in absolute brain weights are not considered 

treatment-related in 500 ppm females. 

FOB testing revealed no treatment-related effects. Slightly decreased motor activity was 

observed in all treated males and in high dose females on Day 1, and this finding is considered to 

be potentially treatment-related. However, due to a lack of any other indications of neurotoxicity

in this study (altered FOB parameters, clinical observations or neuropathy) a slight depression of 

motor activity is likely not indicative of a neurotoxic effect. Although potentially treatmentrelated, the slight decrease in motor activity in males at the low dose was not considered 
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sufficiently adverse to be considered for the determination of the LOAEL.

Absolute and relative adrenal weights were statistically significantly increased in 1500 ppm 

females and 5000 ppm males and females. Upon gross necropsy, the adrenal cortex of all 5000 

ppm animals was discoloured to light beige and it was moderately enlarged in 5000 ppm 

females. Microscopic evaluation revealed diffuse vacuolation of the adrenal cortex in 1500 and 

5000 ppm animals of both sexes. The severity of vacuolation appeared to increase with dose. 

A NOAEL of 500 ppm (30/41 mg/kg bw/day in males/females) was selected based on the 

increased adrenal weights in females and the altered adrenal histopathology of both sexes 

observed at the LOAEL of 1500 ppm (89/99 mg/kg bw/day). No evidence of neurotoxicity.

The study is classified as acceptable/guideline as a subchronic neurotoxicity study in rats 

(870.6200; OECD 424).

A.4.8 Metabolism

870.7485 Metabolism - Rat

In a series of metabolism studies, 

14C-cyflumetofen (>98% radiochemical purity), labeled either 

on the benzene ring in the 4-tert-butylphenyl group (A-ring) or on the benzene ring in the α,α,αtrifluoro-o-tolyl group (B-ring), was administered via gavage in aqueous hydroxypropyl

cellulose to 3-4 Fischer rats/sex/dose/radiolabel position at dose levels of 3 or 250 mg/kg bw. 

Rats were sacrificed either at Tmax (1 or 2 hours post-dosing), or at 24, 48 or 72 hours after 

dosing. The 14C-time course in plasma; the 14C-excretion in urine, feces and bile; and the 

distribution to organs and tissues were examined. In addition, the profile of the metabolites in 

urine, feces and bile was determined. 

14C-cyflumetofen was rapidly absorbed following administration of the low dose, with plasma 

levels of radioactivity peaking at 1 hour post-dosing. Absorption was slightly slower following 

administration of the high dose, with peak plasma levels attained at 2-4 hours post-dosing. At 

the high dose, females demonstrated higher Cmax and AUC values than males for both 

radiolabels. The AUC values at the high dose were approximately 15-16 and 36-38 times the 

AUC at the low dose for males and females, respectively; these values are much lower than the 

83-fold difference in dose levels, indicating saturation of absorption. The half-lives of 

elimination from plasma ranged from 12 to 22 hours, with no consistent pattern in terms of 

differences related to sex, dose or radiolabel position. The half-lives of elimination from whole 

blood, kidney and liver were comparable to the elimination rates from plasma, but longer 

elimination half-lives were calculated for bone marrow (14-30 hours) and adipose tissue (19-43 

hours). 

The absorption rates for the A-ring group were higher for the low dose group (68% and 71% in 

males and females, respectively) than for the high dose group (46% for both males and females). 

For the B-ring groups, the absorption rate was higher in females (78%) than in males (69%) at 

the low dose, but higher in males (44%) than in females (35%) at the high dose. 
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At 72 hours post-dosing, the total radioactivity recovered in tissues and carcass accounted for 

approximately 0.4-2.5% of the administered dose, with lower proportions recovered in tissues 

from rats in the high dose group than in the low dose group. For all dose groups, the 

gastrointestinal tract, carcass, and liver and kidney contained the highest proportions of 

radioactivity. The remaining tissues generally contained 0.002% of the administered dose or less 

at 72 hours. 

For the low dose groups, biliary, urinary and fecal excretion accounted for approximately 25-

37%, 29-51% and 6-17% of the administered dose, respectively. For the high dose groups, 

biliary, urinary and fecal excretion accounted for approximately 18-32%, 11-24% and 34-41% of 

the administered dose, respectively. Most of the radioactivity excreted in urine from low dose 

rats (90-96%) was eliminated within 24 hours after dosing, whereas at the high dose, excretion 

was slower with only 74-88% of the radioactivity excreted in urine being eliminated with 24 

hours of dosing. At both low and high doses, 60-89% of the radioactivity excreted in feces was 

eliminated within 24 hours of dosing.

The unchanged parent was not detected in the urine of any test group. For both radiolabels, 

metabolite AB-3 was identified as a major metabolite in the urine of female rats but was a minor 

urinary metabolite in males. For the A-ring label, metabolite A-18 was a major metabolite 

common to both males and females administered low and high doses, while metabolite A-21 was 

detected at high levels in the urine of both sexes in the low dose group and males from the high 

dose group, but was minimal in the urine of females from the high dose group. Minor 

metabolites common to males and females from the low and high dose groups administered the 

A-ring label included A-20, AB-2, and [A-6]-GA. For the B-ring label, metabolites [B-1]-TLA, 

B-1, and [B-1]-MA were major components in urine of both males and females from both the 

low and high dose groups. Metabolite AB-2 was a minor metabolite in urine of all test groups 

except females from the low dose group, in which residues for this metabolite reached 4% of the 

administered dose. 

In feces, the unchanged parent and metabolites A-20 and A-12 were detected in the low dose 

groups administered the A-ring label, each accounting for approximately 2-4% of the 

administered dose. However, in the corresponding high dose groups, unchanged parent was 

detected in feces at 62-63% of the administered dose while metabolites A-12 and A-20 were 

detected at approximately 1%. Following administration of the B-ring label, the unchanged 

parent detected in feces accounted for approximately 2% of the administered dose for the low 

dose groups, but increased at the high dose to 66% and 54% of the administered dose for males 

and females, respectively. The only metabolite detected in feces was metabolite B-1, which was 

detected at much higher levels in the low dose groups than the high dose groups.

The major metabolites detected in the bile from all test groups were the glucuronic acid 

conjugates of metabolites AB-1 and AB-3. Metabolite AB-2 was also detected at lower levels in 

the bile from all test groups. Unique metabolites identified in the bile of rats administered the Aring or B-ring label included the glucuronic acid conjugate of A-6 and the glutathione conjugate 

of B-1, respectively.
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14C-cyflumetofen was metabolized in the rat primarily by hydrolytic cleavage of the 

trifluoromethylbenzoyl moiety resulting in metabolite B-1 (trifluoromethylbenzoic acid) and A18. Another minor pathway included successive hydroxylation of the tert-butyl side chain. 

This series of metabolism studies in the rat is classified as acceptable/guideline and satisfies the 

guideline requirement for a metabolism study (OPPTS 870.7485; OECD 417) in rats. 

870.7600 Dermal Absorption - Rat

In a dermal absorption study (MRID 48542724), a dermal absorption of 14C-BAS 9210 

(cyflumetofen) was examined in vivo in male rats after a single dermal application at 2, 20 or 

2000 μg/cm2 doses. A 100 μl of each dose was applied to10 cm2skin area to groups of 4 animals 

each. Each dose was washed after 8h of exposure and groups of animals were sacrificed at 8h, 

24h or 120h. An additional skin wash before sacrifice was given to groups monitored for 24h or 

120h. The dermal absorption, as % of applied radioactive dose, increased over monitored time 

of 5 days; but decreased with increase in dose. The dermal absorption, as sum of excreta, blood 

and carcass, was 4.93% (8h), 6.48% (24h) and 8.02% (120h) in 2 μg/cm2 dose groups; 0.63% 

(8h), 1.27% (24h) and 2.20% (120h) in 20 μg/cm2 dose groups; and 0.26% (8h), 0.53% (24h) and 

0.96% (120h) in at 2000 μg/cm2 dose groups. Recovery of the applied dose (mass balance) was

acceptable at all dose levels (93 -108 %). The majority of the administered dose was recovered 

in first skin wash after 8h of exposure at all dose levels (85 -95%). The amount of radioactivity 

recovered in non-occlusive protective cover was small for mid and high dose groups and up to 

25.52% in low dose groups. The amount retained at the application sites was 5.18% (8h), 1.44 % 

(24h) and 1.00 %(120h) in 2 μg/cm2dose groups; 4.88% (8h), 2.13 %(24h) and 1.32 % (120h) in 

20 μg/cm2dose groups; 6.48% (8h), 2.24 %(24h) and 0.45 %(120h) in 2000 μg/cm2dose 

groups. Small amounts were also detected in skin surrounding the test site and in skin strips. As 

the residues at the application site skin and in skin strips were absorbed over 5 days, they were 

included in the total estimate of dermal absorption (Table 3). The residues in the surrounding 

skin samples were variable, but were lower in 120h groups compared to 8h groups. Therefore, 

these residues were also included in the estimate. Thus, the total amount of test substance 

absorbed over time by each animal was estimated as the sum of the quantity found in the excreta 

(urine, feces and cage wash), blood (cells + plasma), carcass and skin (at the application site + 

surrounding skin + skin strips). The estimated dermal absorption were: 11.33% (8h), 10.86% 

(24h) or 9.5% (120h) in low dose (2 μg/cm2) groups; 7.74 %(8h), 6.09 % (24h) and 3.9 % (120h) 

in 20 μg/cm2groups; and 7.28 %(8h), 3.02% (24h) and 1.63% (120h) in 2000 μg/cm2groups.

The test substance doses and exposure time were selected based on the application rate of the 

concentrated and spray diluted product expected in the field in actual use conditions. Given the 

uncertainty regarding actual deposition under field conditions and worker exposure time frame, it 

is considered appropriate to derive an estimate of dermal absorption based on the results from the 

low dose group (2 μg/cm2) sacrificed at 8 hr after a skin wash, as the percent dermal absorption 

was highest in this dose group. Thus, the estimated dermal absorption is 11%. This value is 

considered conservative as the residues retained at the skin site and surrounding skin as well as 

residues found in the skin strips was included in this estimate and it is possible that all of the skin 

residues may not become systemically available. 
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This study is classified as acceptable/guideline and satisfies the guideline requirement for a 

dermal absorption study (OPPTS 870.7600) in rats. 

A.4.9 Immunotoxicity

870.7800 Immunotoxicity- Rat

In an immunotoxicity study (MRID 48542726), BAS 9210 I (97.08% a.i.) was administered to 8 

female Wistar rats/dose in the diet at dose levels of 0, 500, 1500, or 5000 ppm (0, 33, 107, or 349

mg/kg bw/day) for 28 days. An additional group of 8 female rats was dosed with 

cyclophosphamide monohydrate in drinking water at a dose level of 4.5 mg/kg bw/day to serve 

as positive control. Systemic toxicity parameters were evaluated, and immunotoxicity was 

investigated by performing an enzyme-linked immunoabsorbant assay (ELISA) to measure 

serum IgM responses to sheep red blood cells (sRBC) following immunization with SRBC.

A statistically significant increase (p≤0.01) in absolute and relative adrenal weights was 

observed in the 1500 and 5000 ppm dose groups. Correlating histopathology was noted as 

vacuolation of adrenal cortical cells, with severity increasing with dose. In addition, light 

discolouration and enlargement of the adrenals was noted in the 1500 and 5000 ppm dose 

groups. There were no treatment related effects on mortality, clinical signs, body weights, body 

weight gains, or food consumption at any dose level. 

The LOAEL for systemic toxicity was 1500 ppm (107 mg/kg bw/day) based upon increased 

adrenal weights and correlating histopathology. The NOAEL for systemic toxicity is 500 

ppm (33 mg/kg bw/day) in female rats.

There was no evidence of immunotoxicity. No effects of treatment were observed on the 

humoral immune response as measured by the primary serum IgM antibody response to the Tdependent antigen, sheep erythrocytes. Spleen and thymus weights were unaffected by

treatment. Positive control rats demonstrated an 81% decrease (p≤0.01) in serum titer compared 

to concurrent controls, demonstrating the ability of this ELISA to detect suppression of the 

humoral immune response.

The LOAEL for immunotoxicity was not established. The NOAEL for immunotoxicity is 

5000 ppm (349 mg/kg bw/day) in female rats.

This immunotoxicity study is classified acceptable/guideline and satisfies the guideline 

requirement for an immunotoxicity study (OPPTS 870.7800) in the rat. 
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A.5 Summary of Toxicological Doses and Endpoints for Cyflumetofen

Table A.5. Summary of Toxicological Doses and Endpoints for Cyflumetofen 

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)

An acute reference dose has not been established for either the general population or for Females 

13-49 years of age since there were no appropriate studies that demonstrated evidence of toxicity 

attributable to a single dose for these populations. 

Chronic 

Dietary (All 

Populations)

NOAEL =

16.5 

mg/kg/day

UFA= 10x

UFH= 10x

FQPA SF= 1x

Chronic RfD = 

0.17 mg/kg/day

cPAD = 0.17

mg/kg/day

Three co-critical studies:

90-day feeding study in rats

LOAEL = 1000 ppm (54.5/62.8 mg/kg/day in 

M/F) based on hematology and organ weight 

changes in the liver, adrenal, kidney and 

ovaries; and histopathology effects in the 

adrenals and the ovaries. NOAEL=300 ppm 

(16.5/19 mg/kg/day in males/females)

Chronic toxicity/carcinogenicity study in rats

LOAEL = 1500 ppm (49.5/61.9 mg/kg/day in 

M/F) based on increased adrenal weights and 

histopathology. NOAEL=500 ppm (16.5/20.3 

mg/kg/day in males/females)

Two generation reproduction study in rats

Parental: LOAEL = 500 ppm (30.6/46.6 

mg/kg/day in M/F) based on increased organ 

weight and histopathology in adrenals. 

NOAEL=150 ppm (9.2/13.8 mg/kg/day in 

males/females)

Incidental Oral 

(Short- and 

IntermediateTerm) 

NOAEL =

16.5 

mg/kg/day

UFA= 10x

UFH= 10x

FQPA SF= 1x

Residential LOC 

for MOE = 100 Same as chronic dietary endpoint

Dermal 

(Short-, 

Intermediateand LongTerm) 

No dermal hazard was identified. No appropriate endpoint was selected for risk assessment. 

Inhalation 

(Short-, 

Intermediateand LongTerm) 

NOAEL =

16.5 

mg/kg/day

UFA= 10x

UFH= 10x

FQPA SF= 1x

Occupational 

and Residential 

LOC for MOE = 

100

Same as chronic dietary endpoint

Cancer (oral, 

dermal, 

inhalation)

CARC Classification: Suggestive Evidence of Carcinogenic Potential.

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. UFA = 

extrapolation from animal to human (interspecies). UFH = potential variation in sensitivity 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. N/A = not applicable.
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Appendix B. Metabolism Summary Table

B.1 Structures of Cyflumetofen Metabolites

Table B.1. Cyflumetofen and Metabolite Structures

Common Names / 

Code Chemical Name (IUPAC) Chemical Structure

Cyflumetofen

BAS 9210 I

OK-5101

2-methoxyethyl (RS)-2-(4-tertbutylphenyl)-2-cyano-3-oxo-3-(α,α,αtrifluoro-o-tolyl)propionate

CAS: 2-methoxyethyl α-cyano-α-[4-(1,1-

dimethylethyl)phenyl]-β-oxo-2-

(trifluoromethyl) benzenepropanoate

A-1

2-methoxyethyl (RS)-(4-tert-butylphenyl) 

cyanoacetate

A-2

(4-tert-butylphenyl) acetonitrile

A-12

4-tert-butylbenzoic acid

A-18 (4-tert-butylphenyl) cyanoacetic acid

B-1

o-trifluoromethylbenzoic acid

B-3 CAS: 2-(trifluoromethyl) benzamide

NC

O

OH

CF3

O

NH2
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Table B.1. Cyflumetofen and Metabolite Structures

Common Names / 

Code Chemical Name (IUPAC) Chemical Structure

AB-1

(RS)-2-(4-tert-butylphenyl)-3-oxo-3-

(α,α,α-tifluoro-o-tolyl) propiononitrile

AB-6

AB-7

AB-11

AB-15

AB-1 Dimer

AU-16

CF3 O

NC

O

O

CF3

O

CN

F3C

O

NC

O

O

CN

NC

O

O

O

O

CF3 O

NC

O

O

OH
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Table B.1. Cyflumetofen and Metabolite Structures

Common Names / 

Code Chemical Name (IUPAC) Chemical Structure

AU-17

CF3

O

CN

NC

O

O

O
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B.2 Tabular Summary of Metabolites and Degradates

Table B.2. Tabular Summary of Cyflumetofen Metabolites and Degradates

Metabolite Name and 

Structure

Matrix Percent TRR (PPM)

A Label (Butylphenyl) B Label (Benzoyl)

Matrices -

Major 

Residue 

(>10%TRR)

Matrices -

Minor Residue 

(<10%TRR)

Matrices -

Major Residue 

(>10%TRR)

Matrices -

Minor Residue 

(<10%TRR)

Cyflumetofen Apple 61.0% (Day 

1)

78.2% (Day 

7)

53.2% (Day 

30) 

58.4% (Day 1)

83.8% (Day 7)

64.9% (Day 30)

Eggplant 95.0% (Day 

1)

66.9 (Day 7)

62.2 (Day 

14)

91.2% (Day 1)

70.7% (Day 7)

42.4% (Day 14)

Mandarin 89.8% (Day 

1)

82.6% (Day 

7)

54.0% (Day 

30)

88.4% (Day 1)

78.9% (Day 7)

43.9% (Day 30)

Rotational 

Crops

Ruminant Feces -

45.6%

Fat (abdominal) 

– 19.6%

Fat (kidney) –

21.0%

Feces – 7.4%

Rat1Feces –

3.3% –

63.5%

Feces – 2.5% -

65.7%

B-1 

(2-

trifluoromethylbenzoic 

acid)

Apple 1.2% (Day 7)

1.8% (Day 30)

Eggplant 10.6% (Day 7)

14.8% (Day 14)

16.2% 

(Conjugate –

Day 14)

2.5% (Day 1)

Mandarin 11.2% (Day 30) 4.7% (Day 1)

6.6% (Day 7)

Rotational 

Crops

0.2%2

Ruminant Liver – 32.0%

Kidney – 53.9%

Muscle (leg) –

50.5%

Milk – 4.5%
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Table B.2. Tabular Summary of Cyflumetofen Metabolites and Degradates

Metabolite Name and 

Structure

Matrix Percent TRR (PPM)

A Label (Butylphenyl) B Label (Benzoyl)

Matrices -

Major 

Residue 

(>10%TRR)

Matrices -

Minor Residue 

(<10%TRR)

Matrices -

Major Residue 

(>10%TRR)

Matrices -

Minor Residue 

(<10%TRR)

Muscle (back) –

46.5%

Urine – 47.0%

Feces – 63.9%

Bile – 22.4%

Fat (abdominal) 

– 40.2%

Fat (kidney) –

21.0%

Rat1Feces – 6.0% -

27.0%

Urine – 1.4% -

13.5% 

(mercapturic 

acid conjugate)

Urine – 4.3% -

20.2% 

(thiolactic acid 

conjugate)

Urine – 2.6% -

9.7%

AB-6 Apple 1.3% (Day 7)

5.1% (Day 30)

5.3% (Day 30)

Eggplant 8.8% (Day 7)

5.1% (Day 14)

3.0% (Day 7)

3.4% (Day 14)

Mandarin 1.0% (Day 1)

2.1% (Day 7)

7.5% (Day 30)

1.0% (Day 1)

2.5% (Day 7)

8.6% (Day 30)

Rotational 

Crops

Ruminant

Rat1

Apple

AB-7 Apple 6.3% (Day 30) 5.4% (Day 7)

5.3% (Day 30)

Eggplant 4.8% (Day 7)

5.1% (Day 14)

2.9% (Day 7)

3.6% (Day 14)

Mandarin 0.7% (Day 1)

1.6% (Day 7)

7.1% (Day 30)

0.5% (Day 1)

2.0% (Day 7)

8.5% (Day 30)

Rotational 

Crops

Ruminant

Rat1
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Table B.2. Tabular Summary of Cyflumetofen Metabolites and Degradates

Metabolite Name and 

Structure

Matrix Percent TRR (PPM)

A Label (Butylphenyl) B Label (Benzoyl)

Matrices -

Major 

Residue 

(>10%TRR)

Matrices -

Minor Residue 

(<10%TRR)

Matrices -

Major Residue 

(>10%TRR)

Matrices -

Minor Residue 

(<10%TRR)

Notes:

-For plant metabolism studies, rinsate and extract values were summed prior to inclusion in this table.

-Due to rounding of some values with very low residues, accountabilities may be slightly different from those 

reported in earlier tables.

1

For the rat metabolism study, a range is given from the low dose to the high dose groups

2B-1 was seen in the benzoyl labeled spring wheat grain only (30 day PBI) at <0.001ppm
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Appendix C. Physical/Chemical Properties

Table C.1. Physicochemical Properties of the Technical Grade Cyflumetofen

Parameter Value Reference

Molecular weight (g/mole) 447.45 MRIDs 48542735-41

Physical state (21.5°C) White solid (powder)

Melting point (°C) 77.9

pH NA

Density (g/cm3) (23°C) 1.229

Water solubility ( mg/L at 20°C) 0.0277

Solvent solubility (g/L at 20°C) n-Hexane 5.16 

Toluene >500 

Dichloromethane >500 

Acetone >500

Methanol 98.7 

Ethyl acetate >500

Vapor pressure (mm Hg) 4.43 x 10-8at 25 oC

Dissociation constant (pKa) The structural formula does not 

indicate dissociation in the relevant 

pH region (2 to12). The pKa was 

calculated to be - 4.19.

Octanol/water partition coefficient - Log(KOW) 4.3
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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 data, which include the Pesticide 

Handlers Exposure Database Version 1.1 (PHED 1.1); the Agricultural Handler Exposure Task 

Force (AHETF) database; the Outdoor Residential Exposure Task Force (ORETF) database; the 

Agricultural Re-entry Task Force (ARTF) database; and the Residential SOPs (Residential 

Handler) are subject to ethics review pursuant to 40 CFR 26, have received that review, and are 

compliant with applicable ethics requirements. For certain studies that review may have 

included review by the Human Studies Review Board. Descriptions of data sources as well as 

guidance on their use can be found at: http://www.epa.gov/pesticides/science/handler-exposuredata.html and http://www.epa.gov/pesticides/science/post-app-exposure-data.html.
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Appendix E. Residue Summary Table

Table E.1. Summary of Residues from Field Trials with Cyflumetofen

Crop 

Matrix Analyte

Applic. 

Rate

(lb 

ai/acre)

PHI 

(days) n

*

Residues (ppm)

Min.† Max.† LAFT* HAFT* Median* Mean*SD*

Citrus

Orange fruit Cyflumetofen 0.355 –

0.366 7 12 0.010 0.159 0.010 0.116 0.073 0.070 0.035

Grapefruit 

fruit Cyflumetofen 0.357 –0.364 7 6 <0.010 0.077 0.010 0.072 0.038 0.037 0.021

Lemon fruit Cyflumetofen 0.349-

0.358 7 5 <0.010 0.141 0.010 0.135 0.021 0.054 0.054

Pome Fruits

Apple fruit1 Cyflumetofen 0.349-

0.375 6-8 12 <0.010 0.248 0.015 0.163 0.080 0.092 0.048

Pear fruit Cyflumetofen 0.349-

0.375 6-8 5 0.032 0.265 0.049 0.160 0.106 0.098 0.045

Tree Nuts

Pecan 

Nutmeat Cyflumetofen 0.350-0.365 7-8 5 <0.010 <0.010 <0.010 <0.010 0.010 0.010 0

Almond 

Nutmeat Cyflumetofen 0.354-0.356 7 5 <0.010 <0.010 <0.010 <0.010 0.010 0.010 0

Almond 

Hulls Cyflumetofen 0.354-0.356 7 5 0.339 2.046 0.352 1.871 0.0534 0.830 0.610

Strawberry

Strawberry Cyflumetofen 0.351-

0.362 1 8 0.038 0.437 0.042 0.365 0.154 0.171 0.098

Tomato

Tomato2 Cyflumetofen 0.345-

0.364 3 16 <0.010 0.161 0.013 0.148 0.038 0.053 0.038

Tomato3 Cyflumetofen 0.345-

0.364 3 16 <0.019 0.298 0.023 0.274 0.070 0.097 0.071

Grape

Grape Cyflumetofen 0.350-

0.361 14 12 0.014 0.439 0.023 0.423 0.156 0.175 0.103

† Values based on total number of samples. Includes samples from decline trials at proposed PHI.

* Values based on per-trial averages. LAFT = Lowest Average Field Trial, HAFT = Highest Average Field Trial, SD = Standard 

Deviation. For computation of the LAFT, HAFT, median, mean, and standard deviation, values < LOQ are assumed to be at the 

LOQ.

1 Apple fruit trials consisted of four treated samples (two replicates, one dilute and one concentrate) at each field trial site. 

Summary statistics are calculated by using the per-trial average of all four samples.

2 Uncorrected residues of cyflumetofen from tomato field trials.

3 Corrected residues of cyflumetofen for residue loss during freezer storage.