UNI TED STATES ENVIRONMENTALPROTECTI ON AGENCY WASHI NGTON, D.C. 20460 OFFICE OF PREVENTION, PESTICIDES AND

TOXIC SUBSTANCES MEMORANDUM DATE: 16 - October - 2009 SUBJECT: Difenoconazole FQPA Human Health Risk Assessment for the Section 3

Registration of Difenoconazole New Uses on Bulb Vegetables, Brassica Leafy Vegetables, Cucurbit Vegetables, Citrus Fruits, Grapes, Pistachios, and Tree Nuts. PC Code: 128847 DP Barcode: 367382 Decision No.: 403560 Registration No. : 100 - 1 262, 100 - 1312, 100 - 1278, 100 - 1313, and 100 - 1317 Petition No.: PP#8F7482 Regulatory Action: Section 3 Risk Assessment Type: Single

Chemical/Aggregate Case No.: NA T XR No.: NA CAS No.: 119446 - 68 - 3 MRID No.: NA 40 CFR §180.475 FROM : Yan Donovan, Risk Assessor

Bonnie Cropp - Kohlligian, Environmental Scientist Thurston G. Morton, Chemist James S Miller, Environmental Scientist Registration Action Branch IV Health Effects Division (HED); 7509P THROUGH: Ray

Kent, Branch Chief Susan V. Humme l, Senior Chemist Registration Action Branch IV Health Effects Division (HED); 7509P TO: Rosemary Kearns/Tony

Kish (RM 22) Fungicide Branch Registration Division (7505P)Page 2 of 69 Table of Content 1.0 Executive Summary ................................ ................................ ................................ .......... 4 2.0 Ingredient Profile ................................ ................................ ................................ .............. 8 2.1 Summary of Proposed Uses ................................ ................................ .......................... 8 2.2 Structure and Nomenclature ................................ ................................ ...................... 13 3.0 Hazard Characterization/Assessment ................................ ................................ ........... 14 3.1 Hazard and Dose - Response Char acterization ................................ .......................... 15 3.1.1 Toxicological Effects and Dose - response ................................ .......................... 15 3.2 FQPA Considerations ................................ ................................ ................................ . 18 3.2.1. Determination of Susceptibility ................................ ................................ .............. 18 3.2.2. Adequacy of Toxicity Database ................................ ................................ .............. 18 3.2.3. Degree o f Concern Analysis: ................................ ................................ ................... 18 3.2.4. FQPA Safety Factor Recommendation ................................ ................................ ... 19 3.3 Endocrine Disruption ................................ ................................ ................................ . 19 4.0 Public Health and Pesticide Epidemiology Data ................................ .......................... 19 5.0 Dietary Exposure/Risk Characterization ................................ ................................ ..... 19 5.1 Pesticide Metabolism and Environmental Degradation ................................ .......... 19 5.1.1 Metabolism in Primary Crops ................................ ................................ ........... 20 5.1.2 Metabolism in Rotational Crops ................................ ................................ ........ 20 5.1.3 Metabolism in Livestock ................................ ................................ ..................... 20 5.1.4 Analytical Methodology ................................ ................................ ...................... 20 5.1.5 Environmental Degradation ................................ ................................ .............. 21 5.1.6 Comparative Metabolic Profile ................................ ................................ .......... 21 5.1.7 Toxicity Profile of Major Metabolites and Degradates ................................ ... 22 5.1.8 Pesticide Metabolites and Degradates of Concern ................................ ........... 22 5.1.9 Drinking Water Residue Profile ................................ ................................ ........ 22 5.1.10 Food Residue Profile ................................ ................................ ........................... 23 5.1.11 International Residue Limits ................................ ................................ ............. 25 5.2 Die tary Exposure and Risk ................................ ................................ ........................ 25 6.0 Residential (Non - Occupational) Exposure/Risk Characterization ............................ 29 6.1 Residential Handler Exposure and Risk Characterization ................................ ..... 29 7.0 Aggregate Risk Assessments and Risk Characterization ................................ ............ 30 7.1 Acute & Chronic Aggregate Risk ................................ ................................ .............. 30 7.2 Short - and Intermediate - Term Aggregate Risk ................................ ....................... 30 8.0 Cumulative Risk Characterization/Assessment ................................ ........................... 31 9.0 Occupational Exposure/Risk Pathway ................................ ................................ .......... 31 9.1 Occupational Handler Exposure and Risk ................................ ............................... 31 9.2 Occupational Postapplication Exposure and Risk ................................ ................... 36 10.0 Data Needs and Label Recommendations ................................ ................................ .... 38 11.0 References: ................................ ................................ ................................ ....................... 41 12.0 Tolerance Summary ................................ ................................ ................................ ........ 42 13.0 Appendices ................................ ................................ ................................ ....................... 43 Appendix 1: Acute Toxicity Data on Difenoconazole Technical ................................ ........ 43 Appendix 2: Subchronic, Chronic and Other Toxicity Profile ................................ ........... 44Page 3 of 69

Appendix 3. Proposed Metabolic Pa thway for difenoconazole in Rats ............................ 64 Appendix 4 Environmental Fate Degradates ................................ ................................ ..... 66Page 4 of 69

1.0 Executive Summary Difenoconazole is a br oad spectrum fungicide belonging to the triazole group of fungicides (Group 3). It is currently

registered in the U.S. for use as a seed treatment on cereal grains, canola, and cotton and for foliar applications to pome fruits, sugar beets, fruiting veget ables, and tuberous and corm vegetables. Tolerances for difenoconazole are currently established und er 40 CFR §180.475 . Difenoconazole acts by blocking demethylation during sterol biosy snthesis which, in turn, disrupts membrane sy nthesis . Proposed Use

s Under PP#8F7482, Sy

ngenta Crop Protection, Inc. is proposing amended Section 3 registration for a 2.08 lb/gal emulsifiable concentrate (EC) formulation (InspireTM Fungicide; 100 - 1262) to add uses on bulb vegetables, Brassica leafy vegetables, cucurbit veg etables, citrus fruits, tree nuts, and grapes. In addition to adding these new uses to Inspire Fungicide (difenoconazole sole ai), the registrant is requesting that some or all of these new uses to be added to the labels of other mixture products contain ing difenoconazole. These products are Inspire TM XT, Revus Top TM , Quadris Top TM , and Inspire SuperTM

. The subject review addresses the proposed uses for difenoconazole only. Toxicity/Hazard Difenoconazole possesses low acute toxicity by the oral, de rmal and inhalation routes of exposure. It is not considered to be an eye or skin irritant and is not a sensitizer. Difenoconazole exhibits some evidence of neurotoxicity in the database, but the effects are transient or occur at doses exceeding the limi t dose. Itis not mutagenic andit is not a developmental or reproductive toxicant. Chronic effects in rats and mice are seen as cumulative decreases in body weight gains. No evidence of carcinogenicity was seen in rats. Evidence for carcinogenicity w as seen in mice where liver tumors were induced at doses which were considered to be excessively high for carcinogenicity

testing. Treatment - related non - neoplastic lesions were confined to the liver. Tumors were observed in mice at 300 ppm and higher; howe ver, based on excessive toxicity observed at the two highest doses, the absence of tumors at the lower doses and the absence of genotoxic effects, HED’s Cancer Peer Review Committee (CPRC) recommended for a cancer classification of C ( possible human carcin ogen ). A margin - of - exposure (MOE) approach to risk assessment was advocated by the CPRC in July

2007. HED toxicologists reevaluated the endpoints selected by

the HIARC in 1998 and revisited the FQPA factor, since new studies were submitted. HED conclude d that the default 10x FQPA Safety Factor (SF) should be reduced to 1x when assessing dietary and residential exposures The toxicological database for difenoconazole is sufficient to conduct this risk assessment. However, in accordance with Part 158 Tox icology Data requirements, an immunotoxicity study (870.7800) is required for difenoconazole. Endpoints and doses for risk assessment were selected for the following scenarios: Acute dietary (general population including infants and children), chronic di etary , short - term dermal and short term inhalation.Page 5 of 69

Dietary Exposure/Risk Assessment HED has examined the residue chemistry database for difenoconazole and has identified several residue chemistry

data deficiencies . Adequate field trial data have been su bmitted to support the proposed uses of the EC formulation of difenoconazole on bulb vegetables, brassica leafy vegetables, cucurbit vegetables, citrus fruits, pistachios, tree nuts, and grapes. However , the l imited number s o f side - by- side data indicate that residues from the use of the EW formulation are significantly

higher than residue levels from the same use of an EC formulation. Hence, HED concludes that these side - by- side field trial data do not support the proposed uses of the EW formulations on green onions, citrus fruits, cu curbit vegetables, and grapes. Residue data for the triazole metabolites (1,2,4 - T, TA, and TAA) are available to assess the risk from triazole metabolites. Acute and chronic dietary (food + water) risk assessments were co nducted using the Dietary Exposure Evaluation Model - Food Consumption Intake Database (DEEM - FCID  , ver. 2.03. This model uses food consumption data from the United States Department of Agriculture’s (USDA’s) Continuing Survey s of Food Intakes by Individu als (CSFI I; 1994 - 1996 and 1998). The unrefined acute analysis assumed tolerance - level residues, 100% crop treated (CT), and default processing factors. The resulting acute food exposure estimates were less than HED’s level of concern ( <100% of the acute population - adjusted dose (aPAD)) at the 95 th percentile of the exposure distribution for the general U.S. population (7% aPAD) and all population sub groups; the most highly

exposed population subgroup was Children1 - 2 years old with 16% aPAD. The somewhat refined chronic analysis assumed tolerance - level residues for some commodities, field trial residues for the majority of commodities, experimental processing factor for some crops , and 100 % CT. The resulting chronic food exposure estimates were less than HED’s level of concern for the general U.S. population (17% cPAD) and all population sub groups; the most highly

exposed population subgroup was children 1 - 2 years old with 44% cPAD. Residential Exposure/Risk Assessment No new residential uses are being requested at this time. However, a dults and adolescents may be exposed to difenoconazole from its currently registered use on ornamentals. These risks have been previously

assessed . It was concluded that residential pesticide handlers will be e xposed to short - term duration (1 - 30 day s) only . The dermal and inhalation (short - term) residential exposure was assessed for a homeowner mixer/loader/applicator wearing short pants and short sleeved shirts as well as shoes plus socks using a garden hos e - end sprayer, “pump - up” compressed air sprayer, or backpack sprayer. MOEs are >100; therefore are not of concern. With respect to residential post - application exposures, current HED policy (see ExpoSAC minutes from 8/19/99 and 10/11/01) specifies that n o significant post - application exposure is anticipated from ornamentals, either by residents or professional applicators; therefore, no residential post - application assessment was conducted. Aggregate Risk Assessment Acute and chronic aggregate exposures include food plus drinking water exposures. As statedPage 6 of 69

above, acute and chronic aggregate risks are not of concern. Since a common endpoint has been identified for assessment of short - term oral, dermal, and inhalation exposures, short - term aggregate risk assessment combines chronic dietary (food and water) exposure estimates with residential exposure estimates. The proposed residential scenarios result in exposure to only adults. Aggregate MOEs ar e ≥180 and are not of concern. Triazole metabolites The aggregate dietary

(food + water) acute and chronic dietary exposure analy ses for difenoconazole metabolite 1,2,4 - triazole (1,2,4 - T) from all registered and proposed triazole based pesticide uses ar e conducted separately (Memo, T. Morton, D367860, 13 - AUG - 09) as an update to the previously

conducted aggregate dietary exposure risk assessment for 1,2,4 - T (Memo, M. Sahafeyan, DP#341803, 30 - OCT - 07). The updated 1,2,4 - T dietary risk, adding the new use sites associated with the subject petition, showed only a very minimal increase from the previous risk estimates and therefore still is not of concern. The aggregate dietary

(food + water) acute and chronic dietary exposure analy ses were also conducted separately

for difenoconazole metabolites triazole alanine (TA) and triazole acetic acid (TAA) from all registered and proposed triazole - based pesticide uses (Memo, T. Morton, D367860, 13 - AUG - 09) as an update to the previously conducted aggregate dietary e xposure risk assessment for TA + TAA (M. Sahafeyan, DP#344298, 30 - OCT - 07). The updated TA+TAA dietary risk, adding the new use sites associated with the subject petition, showed only a very minimal increase from the previous risk estimates and therefore s till is not of concern. Occupational Handler and Postapplication Exposure/Risk Assessment Based on the label information, HED believes occupational pesticide handlers will be exposed to difenoconazole for short - term duration (1 - 30 day s), but not to intermediate - term (1 - 6 months) duration. Mixer/loader’s dermal, inhalation, and combined MOEs were greater than the level of concern (MOE > 100) while wearing label - specified PPE and therefore not of concern to HED for this registration action. Itis p ossible for agricultural workers to have post - application exposure to pesticide residues during the course of ty

pical agricultural activities. For all short - term post - application activities in this registration action, MOEs were ≥ 100 and therefore not of concern. Recommendations for Tolerances and Registration Pending submission of a revised Section B (see Section 10.0 under Directions for Use) and a revised Section F (see Section 10.0 under Proposed Tolerances), there are no residue chemistry issues that would preclude granting conditional registration for the requested uses of the EC and SC formulations of difenoconazole on bulb vegetables, Brassica leafy vegetables, citrus fruits, cucurbit vegetables, pistachios, tree nuts, and grapes; and, in consi deration of the specific use proposals, for the requested uses of the EW formulation of difenoconazole on almonds, pistachios, Brassica leafy vegetables, and bulb onions or establishment of tolerances for residues of difenoconazole only in/on the following commodities: Almond, hulls ................................ ................................ ....... 7.0 ppmPage 7 of 69 Brassica, head and stem, subgroup 5A ............................ ...1.9 ppm Brassica, leafy

greens, subgroup 5B......................... 35 ppm Citrus, dried pulp ................................ ................................ . 2.0 ppm Citrus, oil ................................ ................................ ........... 25 ppm Fruit, citrus, group 10 ................................ ........................... 0.60 ppm Grape ................................ ................................ .................... 4.0 ppm Grape, raisin ................................ ................................ ......... 6.0 ppm Nut, tree, group 14 ................................ ............................... 0.03 ppm Onion, bulb, subgroup 3 - 07A ................................ .............. 0.20 ppm Onion, green, subgroup 3 - 07B ................................ ............. 6.0 ppm Pistachio ................................ ................................ ............... 0.03 ppm Vegetable, cucurbit, group 9 ................................ ................ 0.70 ppm HED cannot recommend in favor of granting conditional registration for the requested uses of the 0.73 lb/gal MAIEW formulation (EPA Reg. No. 100 - 1317) on green onions, subgroup 3 - 07B; citrus fruits, group 10; cucurbit vegetables, group 9; and grape. Green onion, orange, cantaloupe, and grape field trial data are required to support these propos ed uses of the 0.73 lb/gal MAIEW formulation (EPA Reg. No. 100 - 1317). Data are required reflecting the proposed maximum use rates and minimum PHI s in accordance with OPPTS 860.1500 guidelines. Notes to PM: (1) I f not already

addressed, corrections are n eeded to the existing tolerances listing under 40 CFR §180.475(a)(1), as specified in the most recent revision of this section (Rev. 7/1/08).

 The tolerances for wheat forage, grain, and straw, each at 0.1 ppm, were inadvertently removed [when tolerances were established in conjunction with 6F7115 (73 FR 1508, 1/9/08)] and should be reinstated.  The tolerance level for sugar beet (0.01 ppm) is in error and should be corrected to 0.30 ppm. (2) The recommended tolerance for grape (4.0 ppm) should replace the existing import tolerance for grape (0.10 ppm). (3) According to HED’s Interim Guidance on Tolerance Expressions (5/27/09, S. Knizner), the tolerance expression for difenoconazole should be revised to state: “Tolerances are established for residues of difenoconazole, including its metabolites and degradates, in or on the commodities in the table below. Compliance with the tolerance levels specified below is to be determined by measuring only

difenoconazole [[1 - [2 - [2 - chloro - 4 - (4 - chlorophenoxy

)phenyl] - 4 - methyl - 1,3 - dioxolan - 2 - yl methyl] - 1H - 1,2,4 - triazole].” (4) Regardless of the active ingredient, in general, HED continues to recommend caution in translating data from other formulations to support uses of an EW formulation. Environmental Justice Consider ationsPage 8 of 69

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 Population s and L ow - In come 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 subgr oups according to well - established procedures. Inline 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 th at involve pesticide use in a residential setting. Extensive data on food consumption patterns are compiled by the USDA under the Continuing Survey of Food Intake by

Individuals (CSFI I) and are used in pesticide risk assessments for all registered food us es of a pesticide. These data are analy zed 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 assessm ents 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 postapplication 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 by standers and farm workers as well as l ifestyle and traditional dietary patterns among specific subgroups. 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 studie s, which comprise the Pesticide Handlers Exposure Database (PHED) and information from the Agricultural Re - Entry Task Force (ARTF) and the Outdoor Residential Exposure Task Force (ORETF), have been determined to require a review of their ethical conduct, h ave received that review, and were considered appropriate (or ethically conducted) for use in risk assessments. 2.0 Ingredient Profile 2.1 Summary of Proposed Uses (HED memo of B. Cr opp - Kohlligian, 9/17/09, D361054 and 362648) The subject end - use products are identified in Table 2.1a, and the proposed use directions are summarized in Table 2.1b.Page 9 of 69

Table 2.1a. Summary of Proposed End - Use Products . Trade Name Reg. No.

(File Symbol) a i Content Formulation Ty pe Target Crops Relevant to

PP#8F7482 Label

Date InspireTM Fungicide 100 - 1262 Difenoconazole 2.08 lb/gal (23.2%) Emulsifiable

concentrate (EC) Almonds, filberts, pecans,

pistachios, and tree nuts; Brassica leafy vegetables; bulb vegetables; citrus fruits; cucurbit vegetables, and grapes 11/14/08

InspireTM XT Fungicide 100 - 1312 Difenoconazole 2.08 lb/gal (22.8%) Propiconazole 2.08 lb/gal (22.8%) EC Almonds, filberts, pecans, pistachios, and tree nuts; and bulb vegetables 11/14/08

Revus TopTM Fungicide 100 - 1278 Difenoconazole 2.08 lb/gal (21.9%) Mandiprop amid 2.08 lb/gal (21.9%) EC Brassica leafy vegetables; bulb vegetables; cucurbit vegetables; and grapes 11/13/08

Quadris TopTM Fungicide 100 - 1313 Difenoconazole 1.05 lb/gal (11.4%) Azoxystrobin 1.67 lb/gal (18.2%) Suspension

concentrate (SC) Almonds, filb erts, pecans,

pistachios, and tree nuts; Brassica leafy vegetables; bulb vegetables; citrus fruits; cucurbit vegetables, and grapes 11/14/08

Inspire SuperTM Fungicide 100 - 1317 Difenoconazole 0.73 lb/gal (8.4%) Cyprodinil 2.09 lb/gal (24.1%) Emulsion oil

i n water (EW) Almonds and pistachios;

Brassica leafy vegetables; bulb vegetables; citrus fruits; cucurbit vegetables, and grapes 11/14/08Page 10 of 69

Table 2.1b. Summary of Directions for Use of Difenoconazole. Applic. Timing, Ty pe, and Equip. 1 Formulation

[EPA Re g. No.] Applic.

Rate (lb ai/A) Max. No.

Applic. per Season Max.

Seasonal Applic. Rate (lb ai/A) PHI

(days) Use Directions and

Limitations 1,2 Almonds; filberts (hazelnuts); pecans; pistachios; and tree nuts including: beech nut; Brazil nut; butternut; c ashew,

chestnut; chinquapin; hickory; macadamia; walnut, black; and walnut, English Foliar, Broadcast, Ground ( ≥15 gal/A) or aerial ( ≥10 gal/A) 2.08 lb/gal

EC [100 - 1262] 0.08 -

0.114 Not

specified (NS) 0.46 14 Apps. to begin: prior to disease onset (all) , or at early bloom (blossom blight; almonds), or when green leaf tissue becomes visible (Botryosphaeria; pistachios). No more than 2 consecutive apps. to be made before alternation with a different MOA fungicide. A 14 - to 21 - day or 14 - day (pecan) RTI is specified. 2.08 lb/gal MAI EC [100 - 1312] NS 60 (all but pecan) NS (pecan) As for 100 - 1262 except: for

anthracnose in almonds, apps. to begin at bud break with a 7 - to 14 - day RTI; for filberts, apps. to begin w

hen green leaf tissue becomes visible; f

or pecans, app. after shuck split is prohibited. Grazing livestock in treated area or cutting treated cover crop for feed is prohibited. 1.05 lb/gal MAI SC [100 - 1313] 0.08 -

0.12 4 28 (almond) 14 (pistachio) 45 (all others) As for 100 - 1262 except no

tre atment timing specified for Botyrosphaeria in pistachios. 0.73 lb/gal MAI EW [100 - 1317] 0.07 -

0.114 5 60 (almond) 14 (pistachio) As for 100 - 1262 except: label

includes almonds and pistachios only; no treatment timing specified for blossom blight in almo nds or for Botyrosphaeria in pistachios. Aerial app. restricted to CA only: 1 app., with additional apps. by ground equipment.Page 11 of 69

Table 2.1b. Summary of Directions for Use of Difenoconazole. Applic. Timing, Ty pe, and Equip. 1 Formulation

[EPA Re g. No.] Applic.

Rate (lb ai/A) Max. No.

Applic. per Season Max.

Seasonal Applic. Rate (lb ai/A) PHI

(days) Use Directions and

Limitations 1,2 Brassica (Cole) Leafy Vegetables Subgroup: Broccoli; broccoli, Chinese (gai lon); broccoli raab (rapini); Brussels sprouts; c abbage; cabbage, Chinese (bok choy); cabbage, Chinese (napa); cabbage, Chinese mustard (gai choy); cauliflower; cavalo broccolo; collards; kale; kohlrabi; mizuna; mustard greens; mustard spinach; rape greens Foliar, Broadcast, Ground ( ≥15 gal/A), aerial ( ≥5 gal/A), or chemigation 2.08 lb/gal

EC [100 - 1262] 0.08 -

0.114 NS 0.46 1 Apps. to begin prior to disease onset. No more than 2 consecutive apps. to be made before alternation with a different MOA fungicide. A 7 - to 10 - day RTI is specified. 2.08 lb/gal MAI EC [100 - 1278] 0.09 -

0.114 4 1.05 lb/gal MAI SC [100 - 1313] 0.07 -

0.12 4 0 As above except only 1 app. may be made before alternating to a different MOA (non Qol/Group 11) fungicide, , and a 7 - to 14 - day RTI is specified. Foliar, Broadcast, Ground ( ≥15 gal/A) 0.73 lb/gal

MAI EW [100 - 1317] 0.08 -

0.114 5 7 As above except application is limited to ground equipment. Bulb Vegetables: Chive, fresh leaves; chive, Chinese, fresh leaves; daylily, bulb; elegans hosta; fritillaria, bulb; fritillaria, leaves; garlic, bulb; garlic, great - headed, bulb; garlic, serpent, bulb; kurrat; lady’s leek; leek; leek, wild; lily, bulb; onion, Beltsville bunching; onion, bulb; onion, Chinese, bulb; onion, fresh; onion, green; onion, macrostem; onion, pearl; onion, potato, bulb; onion, tree, tops; onion, Welsh, tops; shallot, bulb; shallot, fresh leaves; cultivars, varieties, and/or hybrids of these Foliar, Broadcast, Ground ( ≥15 gal/A), aerial ( ≥5 gal/A), or chemigation 2.08 lb/gal

EC [100 - 1262] 0.08 -

0.114 NS 0.34

(green onions) 0.46 (bulb onions) 7 Apps. to begin prior to disease

onset. No more than 2 consecutive apps. to be made before alternation with a different MOA fungicide. A 7 - to 10 - day RTI is specified. 2.08 lb/gal MAI EC [100 - 1312] 7 (green onion) 14 (bulb onion) 2.08 lb/gal MAI EC [100 - 1278] 0.09 -

0.114 4 7 1.05 lb/gal MAI SC [100 - 1313] 0.07 -

0.12 As above except only 1 app. may be made before alternating to a different MOA (non Qol/Group 11) fungicide, and a 7 - to 14 - day RTI is specified. Foliar, Broadcast, Ground ( ≥15 gal/A) 0.73 lb/gal

MAI EW [100 - 1317] 0.08 -

0.114 5 As above except application is limited to ground equipment.Page 12 of 69

Table 2.1b. Summary of Directions for Use of Difenoconazole. Applic. Timing, Ty pe, and Equip. 1 Formulation

[EPA Re g. No.] Applic.

Rate (lb ai/A) Max. No.

Applic. per Season Max.

Seasonal Applic. Rate (lb ai/A) PHI

(days) Use Directions and

Limitations 1,2 Citrus: Calamondin; citrus citron; citrus hybrids (includes chironja, tangelo, tangor); grapefruit; kumquat; lemon;

li me; mandarin (tangerine); orange, sour; orange, sweet; pummelo; Satsuma mandarin Foliar, Broadcast, Ground ( ≥15 gal/A) or aerial ( ≥10 gal/A) 2.08 lb/gal

EC [100 - 1262] 0.08 -

0.125 NS 0.5 0 Apps. to begin prior to disease development and continue throughout the season following resistance management guidelines. A 7 - to 21 - day RTI is specified. Use of an adjuvant is permitted; use of a horticultural spray oil is recommended for control of greasy spot. 1.05 lb/gal MAI SC [100 - 1313] 4

0.73 lb/gal M AI EW [100 - 1317] 0.08 -

0.114 5 As above except label specifies lemon and lime only. Aerial app. is restricted to CA only: 1 app., with additional apps. by ground equipment. Cucurbit Vegetables: Chayote (fruit); Chinese waxgourd (Chinese preserving me lon); citron melon; cucumber; gherkin; gourd, edible (includes hyotan, cucuzza, hechima, Chinese okra); Momordica spp. (includes balsam apple, balsam pear, bitter melon, Chinese cucumber); muskmelon (includes cantaloupe); pumpkin; squash, summer; squash, winter (includes butternut squash, calabaza, hubbard squash, acorn squash, spaghetti squash); watermelon Foliar, Broadcast, Ground ( ≥15 gal/A), aerial ( ≥5 gal/A), or chemigation 2.08 lb/gal

EC [100 - 1262] 0.08 -

0.114 NS 0.46 0 Apps. to begin prior to disease onset. No more than 2 consecutive apps. to be made before alternation with a different MOA fungicide. A 7 - to 10 - day RTI is specified. 2.08 lb/gal MAI EC [100 - 1278] 0.09 -

0.114 As above except only 1 app. may be made before alternating to a different MOA fungicide. 1.05 lb/gal MAI SC [100 - 1313] 0.10 -

0.12 4 1 Apps. to begin prior to disease onset or at 1 - t o 3 - leaf stage (for belly rot). No more than 1 app. to be made before alternation with a different MOA fungicide. A 7 - to 14 - day RTI is specified. Foliar, Broadcast, Ground ( ≥15 gal/A) 0.73 lb/gal

MAI EW [100 - 1317] 0.114 5 1 As for 100 - 1262 except app. is limited to ground equipment.Page 13 of 69

Table 2.1b. Summary of Directions for Use of Difenoconazole. Applic. Timing, Ty pe, and Equip. 1 Formulation

[EPA Re g. No.] Applic.

Rate (lb ai/A) Max. No.

Applic. per Season Max.

Seasonal Applic. Rate (lb ai/A) PHI

(days) Use Directions and

Limitations 1,2 Grapes Foliar, Broadcast, Ground ( ≥15 gal/A) or aerial ( ≥10 gal/A) 2.08 lb/gal

EC [100 - 1262] 0.08 -

0.114 NS 0.46 7 Apps. to begin: at bud break with a 10 - to 21 - day RTI (for powdery mildew); or at budbreak before shoots are 0.5” long, then when shoots are 5 - 6” long (Phomopsis); or w

hen shoots are 1 - 3” long with a 10 - day RTI (black rot); or prior to disease onset with a 10 - to 14 - day RTI (all other diseases). No more than 2 consecutive apps. to be made before alternation with a different MOA fungicide. 2.08 lb/gal MAI EC [100 - 1278] 0.09 -

0.114 14 1.05 lb/gal MAI SC [100 - 1313] 0.08 -

0.12 4

0.73 lb/gal MAI EW [100 - 13 17] 0.08 -

0.114 5 7 As above except aerial app is restricted to CA only: 1 app., with additional apps. by ground equipment. 1 MOA = mode of action; RTI = retreatment interval. For the 2.08 lb/gal MAI EC formulation with mandipropamid, use of a nonionic surfactant, crop oil concentrate, or blend is recommended for all proposed uses; use of adjuvants is not addressed on any other labels except for uses on citrus fruits. For the 0.73 lb/gal MAI EW formulation with cyprodinil, the label includes the following statement: “In annual crops, w here multiple crops can be grown per year (double/triple cropping), do not apply more than 1.3 lb ai per acre per year to an individual plot of land.” This appears to apply to cyprodinil. 2 The labels contain the followin g general resistance management guidelines: Use of this product should conform to strategies established for the crop and use area; consult local or State agricultural authorities for strategies that are complementary to those in this label; resistance management strategies may include rotating and/or tank mixing with products having a different MOA or limiting the total number of applications per season. Do not apply to plants grow n for transplanting purposes. 2.2 Structure and Nomenclature The nomenclature of difenoconazole is summarized in Table 2.2a, and the physicochemical properties of difenoconazole are summarized in Table 2.2b.Page 14 of 69

Table 2.2a. Difenoconazole Nom enclature . Chemical structure

O O O Cl N N N C H 3 Cl Common name Difenoconazole Company experimental name CGA - 169374 IUPAC name 1 - ({2 - [2 - chloro - 4 - (4 - chlorophenoxy)phenyl] - 4 - methyl - 1,3 - dioxolan - 2 - yl}methyl) - 1H - 1,2,4 - triazole CAS name 1 - [[2 - [2 - chloro - 4 - (4 - chlorophenoxy)phenyl] - 4 - methyl - 1,3 - diox olan - 2 - yl]methyl] - 1H - 1,2,4 - triazole CAS registry number 119446 - 68 - 3 End - use product (EP) InspireTM; 2.08 lb/gal EC; EPA Reg. No. 100 - 1262 Chemical structure of CGA 205375 metabolite O Cl N N N Cl

O H Table 2.2b. Physicochemical Properties of Difenoconazole. Parameter Value Reference Melting point 78.6 oC DP#s 1 72067 and 178394, 10/26/92, R. Lascola pH 6 - 8 at 20 oC (saturated solution) Density 1.37 g/cm3 at 20 oC Water solubility 3.3 ppm at 20 oC Solvent solubility g/1 00 mL at 25 oC : n - hexane: 0.5 1 - octanol: 35 toluene: 77 acetone: 88 ethanol: 89 Vapor pressure 2.5 x 10 - 10 mm Hg at 25 oC Dissociation constant, pK a <0 Octanol/water partition coefficient, Log(KOW ) 4.2 at 25 oC UV/visible absorption spectrum  max at about 200 and 238 nm (in methanol at 26 oC) PMRA Proposed Regulatory Decision Document on Difenoconazole, 4/14/99 (PRDD99 - 01) 3.0 Hazard Characterization/AssessmentPage 15 of 69

(For detailed discussion, refer to HED memo of M. Sahafeyan, 11/09/07, D346591) The toxicological database for difenoconazole is complete for the purpose of this risk assessment. However, a new data requirement for an Immuno toxicity study is required. 3.1 Hazard and Dose - Response Characterization For a complete list of studies considered, see App endix 1 and 2 under Section 13.0 of this document. 3.1.1 Toxicological E ffects and Dose - response Difenoconazole possesses low acute toxicity by the oral, dermal and inhalation routes of exposure. It is not considered to be an eye or skin irritant and is not a sensitizer. Inan acute neurotoxicity

study in rats, reduced fo re - limb grip strength was observed on day 1 in males and clinical sign s of neurotoxicity in females at the limit dose of 2000 mg/kg. This effect in males is considered as transient since it was not observed at later observation points and toxicity in femal es was observed only at doses exceeding the limit dose . Ina subchronic neurotoxicity

study in rats decreased hind limb strength was observed only in males, which was considered as nonspecific in nature. Itis not a developmental or reproductive toxicant. Chronic effects in the rat study are seen as cumulative decreases in body weight gains. Similarly , chronic feeding studies in mice showed decreased body- weight gains in male and female mice at termination. In mice, treatment - related non - neoplastic l esions were confined to the liver and were supported by clinical chemistry

data at a level of 300 ppm (46 and 58 mg/kg/day for males and females, respectively ). No sy stemic toxicity was observed at the limit dose in a 28 - day dermal toxicity

study in rats. A dermal absorption of 15.3% was observed through rat skin using an in vivo method. Difenoconazole is not mutagenic, and no evidence of carcinogenicity was seen in rats. Evidence for carcinogenicity

was seen in mice, where liver tumors were induced at d oses which were considered to be excessively high for carcinogenicity

testing. L iver tumors were observed in mice at 300 ppm and higher; however, based on excessive toxicity observed at the two highest doses of 2500 and 4500 ppm (females terminated after two weeks due to excessive toxicity resulting in moribundity

and death), the absence of tumors at two lower doses of 10 and 30 ppm and the absence of genotoxic effects, HED’s Cancer Peer Review Committee (CPRC) recommended for a cancer classification of C ( possible human carcinogen ). A margin - ofexposure (MOE) approach in risk assessment was advocated by the CPRC utilizing the no observable - adverse - effects - level (NOAEL) of 30 ppm ( 4.7 and 5.6 mg/kg/day in males and females, respectively

) and the lowest - obs ervable - adverse - effects - level (LOAEL) of 300 ppm ( 46 and 58 mg/kg/day

in males and females, respectively ) from the mouse study

using only

those biological endpoints which were relevant to tumor development ( i.e. , hepatocellular hy pertrophy , liver necrosis, fatty

changes in the liver and bile stasis) (Memo, Jess Rowland and Esther Rinde, 27 - JUL - 1994; Memo, PV Shah, 1 - March - 2007, HED Doc. No. 005453).Page 16 of 69

The doses and toxicological endpoints selected for various exposure scenarios applicable to this risk assess ment are summarized in Table 3.1.3a and Table 3.1.3b. Table 3.1.3a. Sum ma ry of Toxicological Doses and Endpoints for Difenoconazole for Use in Dietary and Non Occupational Hum an - Health Risk Assessm ents. Exposure Scenario Point of

Departure Uncertainty/FQPA

Safety Factors RfD, PAD, LOC for Risk Assessment Study and Relevant Toxicological Effects Acute Dietary (All populations) NOAEL = 25

mg/kg UF A = 10X

UF H = 10X UF FQPA = 1X aRfD = aPAD = 0.25

mg/kg/day Acute Neurotoxicity Study in Rats LOAEL= 200 mg/kg in males based on reduced fore - limb grip strength in males on day 1. Chronic Dietary (All populations) NOAEL =

0.96 mg/kg/day UF A = 10X

UF H = 10X UF FQPA = 1X cRfD = cPAD =

0.01mg/kg/day Combined chronic toxicity/carcinogenicity (rat; dietary) LOAEL = 2 4.1 /32.8 mg/kg/day (M/F) based on cumulative decreases in body - we ight gains. Incidental Oral Short - and Intermediate Term (1 - 30 days and 1 - 6 mo nths) NOAEL =

1.25 mg/kg/day UF A = 10X

UF H = 10X UF FQPA = 1X Residential LOC for

MOE<100 Reproduction and fert ility effects (rat; dietary) Offspring LOAEL = 12.5 mg/kg/day based on reduction in body - we ight of F 1 males. Dermal Short - and Intermediate Term (1 - 30 days and 1 - 6 mo nths) Oral NOAEL

= 1.25 mg/kg/day Dermal Absorption factor=15.3% UF A = 10X

UF H = 10X UF FQPA = 1X Residential LOC for

MOE<100 Reproduction and fertility effects (rat; dietary) Offspring LOAEL = 12.5 mg/kg/day based on reduction in body - we ight gain of F 0 females prior to mating, gestation and lactation. Dermal Long - Term (>6 months) Oral NO AEL

= 0.96 mg/kg/day Dermal Absorption factor=15.3% UF A = 10X

UF H = 10X UF FQPA = 1X Residential LOC for

MOE<100 Combined chronic toxicity/carcinogenicity (rat; dietary) LOAEL = 24.1 /32.8 mg/kg/day (M/F) based on cumulative decreases in body - we ight gains. Inhalation (Short - and Intermediate term) Oral NOAEL

= 1.25 mg/kg/day 100% inhalation absorption assumed UF A = 10X

UF H = 10X UF FQPA = 1X Residential LOC for

MOE<100 Reproduction and fertility effects (rat; dietary) Offspring LOAEL = 12.5 mg/kg/day base d on reduction in body weight gain of F 0 females prior to mating, gestation and lactation. Inhalation (Long - term) Oral NOAEL

= 0.96 UF A = 10X

UF H = 10X Residential LOC for

MOE<100 Combined chronic toxicity/carcinogenicityPage 17 of 69

Table 3.1.3a. Sum ma ry of Toxicological Doses and Endpoints for Difenoconazole for Use in Dietary and Non Occupational Hum an - Health Risk Assessm ents. Exposure Scenario Point of

Departure Uncertainty/FQPA

Safety Factors RfD, PAD, LOC for Risk Assessment Study and Relevant Toxicological Effects mg/kg/day 100% inhalation absorption assumed UF FQPA = 1X (rat; dietary) LOAEL = 24.1 /32.8 mg/kg/day (M/F) based on cumulative decreases in body w eight gains. Cancer (oral, dermal, inhalation) Difenoconazole is classified as a Group C, possible human carcinogen with a non - linear (MOE)

ap proach for human risk characterization (CPRC Document, 7/27/94, Memo, P. V. Shah dated March 3, 2007, HED Doc. No. 0054532). Abbreviations: UF = uncertainty factor, UF A = extrapolation from animal to human (interspecies), UF H = potential variation in sens itivity among members of the human population (intraspecies), UF FQPA = FQPA Safety Factor, NOAEL = no - observed - adverse - effect level, LOAEL = lowest - observed - adverse - effect level, RfD = reference dose (a = acute, c = chronic), PAD = population - adjusted dose , MOE = margin of exposure, LOC = level of concern. Table 3.1.3b. Sum ma ry of Toxicological Doses and Endpoints for Difenoconazole for Use in Occupational Hum an - Health Risk Assessm ents. Exposure Scenario Point of

Departure Uncertainty/FQPA

Safety Factor s RfD, PAD, Level of

Concern for Risk Assessment Study and Toxicological Effects Dermal Short - and Intermediate Term (1 - 30 days and 1 - 6 mo nths) Oral NOAEL

= 1.25 mg/kg/day Dermal Absorption factor=15.3% UF A = 10X

UF H = 10X Occupational LOC for

MOE<100 Reproduction and fertility effects (rat; dietary) Offspring LOAEL = 12.5 mg/kg/day based on reduction in body - we ight gain of F 0 females prior to mating, gestation and lactation. Dermal Long - Term (>6 months) Oral NOAEL

= 0.96 mg/kg/day Dermal Absorption f actor=15.3% UF A = 10X

UF H = 10X Occupational LOC for

MOE<100 Combined chronic toxicity/carcinogenicity (rat; dietary) LOAEL = 24.1 /32.8 mg/kg/day (M/F) based on cumulative decreases in body - we ight gains. Inhalation (Short - and Intermediate term) Oral NOAEL

= 1.25 mg/kg/day 100% inhalation absorption assumed UF A = 10X

UF H = 10X Occupational LOC for

MOE<100 Reproduction and fertility effects (rat; dietary) Offspring LOAEL = 12.5 mg/kg/day based on reduction in body - we ight gain of F 0 females prior to mat ing, gestation and lactation. Inhalation (Long - term) Oral NOAEL

= 0.96 mg/kg/day 100% inhalation absorption assumed UF A = 10X

UF H = 10X Occupational LOC for

MOE<100 Combined chronic toxicity/carcinogenicity (rat; dietary) LOAEL = 24.1 /32.8 mg/kg/day (M/F) based on cumulative decreases in body - we ight gains.Page 18 of 69

Table 3.1.3b. Sum ma ry of Toxicological Doses and Endpoints for Difenoconazole for Use in Occupational Hum an - Health Risk Assessm ents. Exposure Scenario Point of

Departure Uncertainty/FQPA

Safety Factor s RfD, PAD, Level of

Concern for Risk Assessment Study and Toxicological Effects Cancer (oral, dermal, inhalation) Difenoconazole is classified as a Group C, possible human carcinogen with a non - linear (MOE)

approach for human risk characterization (CPRC Document, 7/27/94, Memo, P . V. Shah dated March 3, 2007, HED Doc. No. 0054532). Abbreviations: UF = uncertainty factor, UF A = extrapolation from animal to human (interspecies), UF H = potential variation in sensitivity among members of the human population (intraspecies), UF FQPA = FQPA Safety Factor, NOAEL = no - observed - adverse - effect level, LOAEL = lowest - observed - adverse - effect level, RfD = reference dose (a = acute, c = chronic), PAD = population - adjusted dose, MOE = margin of exposure, LOC = level of concern. 3.2 FQPA Consider ations 3.2.1. Determination of Susceptibility The Hazard I dentification Assessment Review Committee (HIARC) determined that the available Agency

Guideline studies indicated no increased susceptibility of rats or rabbits to in utero and/or postnatal exposure to difenoconazole. In the prenatal developmental toxicity studies in rats and rabbits and the two - generation reproduction study in rats, toxicity

to the fetuses/offspring, when observed, occurred at equivalent or high er doses than in the maternal/parental animals. In the prenatal developmental toxicity study in rats, maternal toxicity was manifested as decreased body weight gain and food consumption at the L OAEL of 85 mg/kg/day ; the NOAELwas 16 mg/kg/day . The develo pmental toxicity was manifested as alterations in fetal ossifications at 171 mg/kg/day ; the developmental NOAEL was 85 mg/kg/day . Ina developmental toxicity study in rabbits, maternal and developmental toxicity were seen at the same dose level (75 mg/kg/ day ). Maternal toxicity

in rabbits were manifested as decreased in body weight gain and decreased in food consumption, while developmental toxicity was manifested as decreased fetal weight. In a 2 - generation reproduction study in rats, there were decreas es in maternal body weight gain and decreases in body weights of F1 males at the LOAEL of 12.5 mg/kg/day ; the parental sy stemic and off spring toxicity NOAEL was 1.25 mg/kg/day . 3.2.2. Adequacy of Toxicity Database There are no data gaps for the asses sment of the effects of difenoconazole following in utero and/or postnatal exposure. The acute and subchronic neurotoxicity studies in rats are available. Inan acute neurotoxicity

study in rats, reduced fore - limb grip strength was observed on day 1 in m ales. This effect is considered as transient since it was not observed at later observation points. Ina subchronic neurotoxicity study in rats decreased hind limb strength was observed only in males, which was considered as nonspecific in nature . Difeno conazole exhibits some evidence of neurotoxicity

in the database, but the effects are transient or occur at doses exceeding the limit dose . EPA concluded that difenoconazole is not a neurotoxic compound. Based on the toxicity profile, and lack of neurotox icity , a developmental neurotoxicity study in rats is not required. 3.2.3. Degree of Concern Analysis:Page 19 of 69

Since there is no evidence of susceptibility , there is no concern for increased susceptibility due to exposure to difenoconazole. 3.2.4. FQPA Safety Factor Recommendation The FQP A factor for increased susceptibility to infant and children is reduced to 1x for the following considerations: 1) toxicology

data base for difenoconazole is complete; 2) there is no indication of increased susceptibility of rats or rabbit fetuses to in utero and/or postnatal exposure in the developmental and reproductive toxicity data; 3) there are no concerns for neurotoxicity ; 4) developmental neurotoxicity study is not required; 5) there are no residual uncertainties i n the toxicology database. 3.3 Endocrine Disruption EPA is required under the Federal Food Drug and Cosmetic Act (FFDCA), as amended by FQPA, to develop a screening program to determine whether certain substances (including all pesticide active and other ingredients) "may have an effect in humans that is similar to an effect produced by

a naturally

occurring estrogen, or other such endocrine effects as the Administrator may designate." Following the recommendations of its Endocrine Disruptor Screening and Testing Advisory

Committee (EDSTAC), EPA determined that there was scientific basis for including, as part of the program, the androgen and thy roid hormone sy stems, in addition to the estrogen hormone sy stem. EPA also adopted EDSTAC’s recommendation that the Program include evaluations of potential effects in wildlife. For pesticide chemicals, EPA will use FIFRA and, to the extent that effects in wildlife may help determine whether a substance may have an effect in humans, FFDCA has authority to require the wildlife evaluations. As the science develops and resources allow, screening of additional hormone systems may be added to the Endocrine Disruptor Screening Program (EDSP). When the appropriate screening and/or te sting protocols being considered under the Agency ’s EDSP have been developed, difenoconazole may be subjected to additional screening and/or testing to better characterize effects related to endocrine disruption. 4.0 Public Health and Pesticide Epidemiolo gy Data Not relevant since these are new uses. 5.0 Dietary Exposure/Risk Characterization 5.1 Pesticide Metabolism and Environmental DegradationPage 20 of 69

5 .1.1 Me tabolism in Primary Crops The nature of the residue in plants is understood based on acceptable plant metabolism studies reflecting foliar applications in canola, grape, potato, tomato, and wheat and seed treatm ent in wheat. Based on the results of available plant metabolism studies, the petitioner has proposed that difenoconazole is metabolized in plants by the hydroxylation of the phenyl ring and/or cleavage of the dioxolane ring followed by cleavage of the carbon - carbon bridge between the phenyl and triazole rings. The metabolic pathway appears to proceed by

hydroly sis of the ketal to the ketone followed by reduction of the ketone (CGA - 205374) to the alkanol (CGA 205375). CGA 205375 can be conjugated with su gars or the bridge linking the phenyl and triazole moieties is cleaved. HED concluded that the residue of concern for both tolerance enforcement and risk assessment for crops included in this petition is difenoconazole per se . The proposed metabolic pathway

is illustrated in Appendix 5. 5 .1.2 Metabolism in Rotational Crops The nature of the residue in rotational crops is not adequately understood because previously conducted studies did not reflect suffici ently high application rates, and/or insufficient characterization/identification of residues was achieved. An additional confined rotational crop study reflecting phenyl - ring labeling must be conducted at 1x the proposed maximum seasonal foliar applicati on rate (0.46 lb ai/A). An acceptable limited field rotational crop study is available; these data will be reevaluated when the outstanding confined rotational crop study is received. In the meantime, the proposed rotational crop restrictions on the subm itted labels are deemed appropriate. 5 .1.3 Metabolism in Livestock The nature of the residue in livestock is understood based on acceptable goat and hen metabolism studies. The data were originally evaluated in su

pport of seed treatment uses only , and HED concluded that the residue of concern in livestock commodities was difenoconazole per se . When the first foliar uses of difenoconazole on crop commodities were proposed (DP# 340379), HED re - evaluated the livestoc k metabolism data and concluded that the residues of concern for both tolerance setting and risk assessment for livestock commodities are difenoconazole and metabolite CGA - 205375. 5 .1.4 Analytical Methodology An ade quate tolerance enforcement method, method AG - 575B, is available for crop commodities. The method determines residues of difenoconazole per se in/on crop commodities by gas chromatography

with nitrogen - phosphorus detection (GC/NPD). The method limits of quantitation (L OQs) are 0.01 - 0.05 ppm. A confirmatory GC method with mass - selective detection (MSD) is also available for crop commodities. Samples from the submitted the crop field trials and processing studies were analy zed for residues of difenoconazo le using a highPage 21 of 69

performance liquid chromatography method with tandem mass spectrometry detection (LC/MS/MS), Sy

ngenta REM 147.08, and for residue of the triazole metabolites TA, TAA, and 1,2,4 - T using Morse Laboratories LC/MS/MS method Meth - 160, Revision # 2. The methods were adequate for data collection based on acceptable concurrent method recoveries. The LOQ was 0.01 ppm for each analy te in each commodity . An L C/MS/MS method, Sy ngenta REM 147.07 was previously submitted under PP#6F7115 (DP# 340379, 8/9 /07, W. Wassell and M. Sahafeyan) for the determination of residues of difenoconazole and CGA - 205375 in livestock commodities. The method L OQs are 0.01 ppm for livestock tissues and 0.005 ppm for milk. HED tentatively concluded that the method would be s uitable for enforcement purposes pending submission of the following: (1) additional information from the independent laboratory validation (ILV) of the method; (2) revision of the method to correct all references to “crop matrices”; (3) confirmatory anal ys is procedures for the method; and (4) successful Agency method validation. Under the current action, Sy ngenta has submitted the required method revision (REM 147.07b), and an acceptable confirmatory method for determination of CGA - 205375, method REM 147 .06, a high performance liquid chromatography

method with ultraviolet detection (HPL C/UV). The previously established tolerance enforcement method for livestock commodities, GC/NPD method AG - 544A, is suitable as a confirmatory method for residues of difen oconazole. In addition, the Analy tical Chemistry

Branch (ACB) has found method REM 147.07 to be adequate for tolerance enforcement without a laboratory trial. The requirement for additional information from the ILV remains outstanding. The revised metho d (REM 147.07b), along with confirmatory method REM 147.06 will be forwarded to FDA for inclusion in the Pesticide Analy tical Method (PAM) Volume I I. 5 .1.5 Environmental Degradation Insoil environment, difenoconazole is persistent and slightly mobile. Difenoconazole has low potential to reach ground water, except in soils of high sand and low organic matter content. I t is likely to reach surface sources of drinking water via spray drift and runoff. In the aquatic environment its main route of dissip ation is partitioning into the bottom sediment, and potentially relatively fast to slow aqueous photoly sis in clear water conditions. Major degradates include CGA 205375 which was found in lab accumulation in fish at 51 - 64% applied dose, and in aerobic soil at 14.8%, in aerobic aquatic at 11.6% and anaerobic aquatic at 12.6% of the applied dose, and CGA 71019 (triazole) and CGA - 142856 (TAA). Since triazole and TAA are common metabolites from a group of chemicals, they should be addressed separately . ( See Appendix 4 for structures) 5 .1.6 Comparative Metabolic Profile Rat metabolism studies (MRID 42090028 through 31, and 42710013 through14) indicated that difenoconazole was rapidly adsorbed and mainly

elimin ated vis bile. Three major urinaryPage 22 of 69

metabolites were isolated and further identified as sulfate conjugates of CGA 205375, isomers of CGA 205375, and the hydroxyacetic metabolite of CGA 205375 . Further metabolism formed free triazoles. The proposed met abolic pathway in rats is presented in Appendix 4. Comparisons of the metabolisms indicated that the metabolic pathways in plants, livestock, rats, and the environment are very similar or identical, with the formation of CGA 205375 and then further metabo lism to form free triazole metabolites. 5 .1.7 Toxicity Profile of Major Metabolites and Degradates Other than the triazole metabolites, no toxicity information is available on the CGA 20 5375 metabolite. Based on structural similarity , it is assumed that the CGA 205375 shares the same toxicity as the parent. 5 .1.8 Pesticide Metabolites and Degradates of Concern The most rece nt MARC visit for difenoconazole is in 1994. In 2007, HED reviewers re evaluated the plant and livestock metabolism studies based on new data submitted in conjunction with the new uses. It was concluded that the residue of concern for both tolerance enfo rcement and risk assessment for currently registered crops is difenoconazole per se . For livestock, the residues of concern for both tolerance setting and risk assessment for livestock commodities are difenoconazole and its metabolite CGA - 205375. With the subject petition, HED determined that previous conclusions on plants and livestock stand. As for drinking water assessment, HED tentatively

concludes that the residues of concern are parent and CGA 205375. For future new uses of difenoconazole, HED recommends that a revisit to the HED ROCKS Committee is needed. 5 .1.9 Drinking Water Residue Profile Drinking water assessment was conducted for parent compound only . The fate and transport database for dife noconazole were sufficient to conduct the drinking water assessment. The Tier II drinking water assessment was performed using PRZM (v3.12.2; May 12, 2005)/EXAMS (v. 2.98.04.06; April 25, 2005) modeling with index reservoir (IR) scen arios and percent cropped area (PCA) adjustment factors. The assessment for the proposed uses was based on difenoconazole uses on citrus fruits and grapes. These are major crops, with difenoconazole maximum application rate to citrus fruits being the high est of all agricultural uses, and grapes being the second highest. An initial simulation analy sis showed that grapes would produce the highest EDWCs of all proposed crop uses with the same maximum application rate of 0.46 lb ai/A hence grapes and citrus fr uits were modeled. Florida and California citrus fruit scenarios were modeled for citrus fruits, and New York and California grapes scenarios were modeled for grapes. Default PCA of 0.87 was used for surface water models. Among all the registered an d proposed new uses, the highest estimated drinkingPage 23 of 69

water concentrations (EDWCs) from surface water sources were derived for aerial applications of difenoconazole to New York grapes at the maximum annual application rate of 0.46 lb ai/acre. The recommended peak and mean estimated drinking water concentrations (EDWCs) for the human health risk assessment are provided in Table 1. These estimates exceed the previously EDWCs from 2007 drinking water assessment ( D333319 ). Table 1. PCA Adjusted Difenoconazole E DWCs from Surface Water Sources. Scenario Application

Ty pe/Annual Fungicide Application Rate (lb ai/A) ) Estimated Drinking Water Concentrations (μg/L) a

1 in 10 year annual peak 1 in 10 year

annual mean 36 year annual

mean NY Grape aerially applied

0. 114 x 4 = 0.46 15.8 10.4 7.62 a EXAMS EECs multiplied by 0.87, a default PCA factor. The highest SCI - GROW estimated drinking water concentration of difenoconazole from shallow ground water sources is 1.23 x 10 - 2 μg/L derived for the maximum propos ed application rate to citrus fruit (0.50 lb ai/A), i.e. agricultural uses. Based on the previous drinking water assessment, this estimate is lower than an estimate for non - agricultural uses 1.28 x 10 - 2 μg/L, obtained for the maximum application rate for o rnamentals (0.52 lb ai/A; D333319 ). These concentrations can be considered as both the acute and chronic values. Currently , no data are available indicating whether water treatment process will increase dissipation and/or will form degradation products that may be more toxic than the parent. HED believes that future drinking water assessment should be conducted for parent and degradate CGA 205375. 5 .1.10 Food Residue Profile (HED memo of B. Cropp - Kohlligian, 9/1 7/09, D361054 and 362648) HED has examined the residue chemistry database for difenoconazole and has identified several residue chemistry

data deficiencies. However, no major residue deficiencies will prevent the establishment of permanent tolerances fo r the proposed uses. For details on data deficiencies, please see Section 10.0 . The nature of the residue in plants is understood based on acceptable plant metabolism studies reflecting foliar applications in canola, grape, potato, tomato, and wheat, and seed treatment in wheat. HED concludes that the residue of concern for both tolerance enforcement and risk assessment for crops included in this petition is difenoconazole per se . The nature of the residue in livestock is understood based on acceptable goat and hen metabolism studies. The residues of concern for both tolerance setting and risk assessment for livestock commodities are difenoconazole per se and its metabolite CGA - 205375. An adequate tolerance enforcement method, method AG - 575B, is availa ble for cropPage 24 of 69

commodities. An L C/MS/MS method, Sy ngenta REM 147.07 was previously submitted under PP#6F7115 (DP# 340379, 8/9/07, W. Wassell and M. Sahafeyan) for the determination of residues of difenoconazole and CGA - 205375 in livestock commodities. The method L OQs are 0.01 ppm for livestock tissues and 0.005 ppm for milk. HED tentatively concluded that the method would be suitable for enforcement purposes pending submission of the following: (1) additional information from the independent laboratory va lidation (ILV) of the method; (2) revision of the method to correct all references to “crop matrices”; (3) confirmatory analy sis procedures for the method; and (4) successful Agency method validation. Supporting storage stability data were not provided in the subject submissions; however, available storage stability data for residues of difenoconazole per se in/on various raw agricultural crop and processed commodities are deemed adequate to support the storage conditions and durations of samples from the crop field trial and processing studies reviewed herein. Adequate feeding study

data have been submitted previously for difenoconazole in cattle and poultry commodities; however, the requirement for supporting storage stability data for the feeding s tudies remains outstanding. No changes to the existing livestock tolerances are needed to support the proposed uses. Adequate field trial data have been submitted to support the proposed uses of the EC formulation of difenoconazole on bulb vegetables, Brassica leafy vegetables, cucurbit vegetables, citrus fruits, pistachios, tree nuts, and grapes. Based on previously submitted side - by- side field trial data for leaf lettuce, mustard greens, and tomatoes comparing residues of difenoconazole per se result ing from use of a 2.08 lb/gal EC formulation with that of a 2.08 lb/gal SC formulation (DP# 354013, 3/20/09, B. Cropp - Kohlligian), and in consideration of the specific use proposals for the SC formulations, the submitted field trial data representing an EC formulation of difenoconazole are also deemed adequate to support the proposed uses of the SC formulation of difenoconazole on these same crops. In consideration of the specific use proposals for the EW formulation, the submitted field trial data represe nting an EC formulation of difenoconazole are also deemed adequate to support the proposed uses of the EW formulation of difenoconazole on almonds and pistachios, Brassica leafy vegetables, and bulb onions, subgroup 3 - 07A. The submitted data will support the proposed tolerances for almond hulls; Brassica, head and stem, subgroup 5A; citrus fruit, group 10; grape; tree nut, group 14, and pistachio; and cucurbit vegetables. The proposed tolerance for Brassica, leafy greens, subgroup 5B is too low; a toleran ce of 35 ppm is appropriate. For bulb onions, subgroup 3 - 07A and green onions, subgroup 3 - 07B, the data will support respective tolerances of 0.20 and 6.0 ppm. The field trial data submitted to support the proposed uses of the EC formulation of difenocon azole on green onions, citrus fruits, cucurbit vegetables, and grapes are not deemed adequate to support the proposed uses of the EW formulation of difenoconazole on these same crops. Sy ngenta has previously

submitted side - by- side field trial data for lea f lettuce, mustard greens, and tomatoes comparing residues of difenoconazole per se resulting from use of a 2.08 lb/gal EC formulation with a 0.73 lb/gal EW formulation (DP# 354013, 3/20/09, B. Cropp Kohlligian). Given the limited scope and nature of thes e side - by- side data, HED has beenPage 25 of 69

reluctant to draw too many conclusions from these data out of context. Collectively , these side by- side field trial data, which represent multiple late - season, foliar applications and 0 - 7 day PHI s, indicate the potential for significantly higher residue levels of difenoconazole per se in/on field crops from the use of the EW formulation when compared to the same use of an EC formulation. The highest average field trial (HAFT) residue levels from the side - by- side field tri als were 28 - 54% higher for the EW formulation than for the EC formulation; mean values were also higher for the EW formulation than for the EC formulation. Hence, HED concludes that these side - by- side field trial data indicate that data for the EC formulation are not adequate to support the proposed uses of the EW formulations on green onions, citrus fruits, cucurbit vegetables, and grapes. Green onion, orange, cantaloupe, and grape field trial data are required to support the proposed uses of the 0.73 lb /gal MAIEW formulation (EPA Reg. No. 100 - 1317) on green onions, subgroup 3 - 07B; citrus fruits, group 10; cucurbit vegetables, group 9; and grape. Data are required reflecting the proposed maximum use rates and minimum PHI s in accordance with OPPTS 860.15 00 guidelines. Adequate processing data for citrus and grape have been submitted to support the proposed uses on citrus fruits and grapes. The submitted data indicate that residues of difenoconazole do not concentrate in orange or grape juice, but do co ncentrate in orange dried pulp, orange oil and raisins. The processing data indicate that the proposed tolerances for processed commodities are too high; tolerances of 2.0 ppm for citrus dried pulp, 25 ppm for citrus oil, and 6.0 ppm for raisin would be a

ppropriate. The nature of the residue in rotational crops is not adequately understood. An additional confined rotational crop study reflecting phenyl - ring labeling must be conducted at 1x the proposed maximum seasonal foliar application rate (0.46 lb ai/A). An acceptable limited field rotational crop study

is available; these data will be reevaluated when the outstanding confined rotational crop study

is received. In the meantime, the proposed rotational crop restrictions on the submitted labels are d eemed appropriate. The tolerance spreadsheet in the Agency ’s Guidance for Setting Pesticide Tolerances Based on Field Trial Data was utilized for determining appropriate tolerance levels for all raw agricultural commodities, groups, or subgroups listed in Table 12.0. 5.1.11 International Residue Limits Codex Maximum Residue L imits (MRL s) for residues of difenoconazole per se have been established at 0.3 ppm for leek, 0.5 ppm for broccoli, 0.2 ppm for Brussels sprouts, 0.2 ppm for cabbage, 0.2 ppm for cauliflower, and 0.1 ppm for grape. Canadian and Mexican MRLs have been established for difenoconazole; however, no MRL s have been established for the requested crops. Based on the submitted field trial data, har monization with established Codex MRL s is not possible because the MRL s for Brassica vegetables, leek, and grape are too low. 5.2 Dietary Exposure and Risk (HED memo of T. Morton, 09/22/09, D367383)Page 26 of 69

Residue Data u sed for Acute and Chronic Assessments: The acute analy sis assumed tolerance - level residues and 100% CT for all the registered and proposed crops. Tolerance - level residues were also assumed for all livestock tissues in this assessment. The chronic analy s is assumed tolerance - level residues for some commodities, field trial residues for the majority of commodities, and 100 % CT. HED SOP 2000.1 Guidance for Translation of Field Trial Data from Representative Commodities in the Crop Group Regulation to Other Commodities in Each Crop Group/Subgroup dated 9/12/2000 was used in translating to other commodities in the crop group. Experimental processing factors were used for apple juice (0.04x), grape juice (0.2x), citrus juices (0.1x), potato chips (0.5x), potato granules/flakes (0.5x), raisin (3.5x chronic only

), sugar beet molasses (0.6x), sugar beet refined sugar (0.6x), tomato paste (1.6x), and tomato puree (0.5x); DEEM  (ver. 7.81) default processing factors were assumed for other processed commodities. Th e estimated drinking water residues for 1 - in - 10 year annual peak (15.8μg/L) was used for the acute run, while 1 - in - 10 year annual mean (10.4 μg/L) was used for chronic. HED notes that degradate CGA 205375 was not included in the drinking water assessme nt ; however, the relative amount of CGA 205375 is not significant in comparison to the parent. DEEM - FCIDTM Program and Consumption Information Difenoconazole acute and chronic dietary exposure assessments were conducted using the DEEM - FCID  (ver. 2.03), whic h incorporates consumption data from USDA’s CSFI I (1994 - 1996 and 1998). The 1994 - 96, 98 data are based on the reported consumption of more than 20,000 individuals over two non - consecutive survey day s. Foods “as consumed” ( e .g. , apple pie) are linked to E PA - defined food commodities ( e .g. , apples, peeled fruit - cooked; fresh or N/S; baked; or wheat flour - cooked; fresh or N/S, baked) using publicly available recipe translation files developed jointly

by USDA/ARS and EPA. For chronic exposure assessment, consumption data are averaged for the entire U.S. population and within population subgroups, but for acute exposure assessment are retained as individual consumption events. Based on analysis of the 1994 - 96, 98 CSFI I consumption data, which took into acc ount dietary patterns and survey respondents, HED concluded that it is most appropriate to report risk for the following population subgroups: the general U.S. population, all infants (<1 year old), children 1 - 2, children 3 - 5, children 6 - 12, youth 13 - 19, adults 20 - 49, females 13 - 49, and adults 50+ years old. Results and Discussion The resulting acute food exposure estimates were less than HED’s level of concern ( <100% aPAD) at the 95 th percentile of the exposure distribution for general US population (7% aPAD) and all population sub - groups; the most highly exposed population subgroup was Children 1 - 2 ye ars old population sub - group with 16% aPAD. The resulting chronic food exposure estimates were less than HED’s level of concern ( <100% cPAD) for general U.S. population (17% cPAD) and all population sub - groups; the most highly exposed population subgroup was children 1 - 2 ye ars old with 44% cPAD. A cancer dietary assessment was not conducted for difenoconazole because the cancer NOAEL is higher than the c hronic RfD; therefore, the chronic dietary riskPage 27 of 69

estimate is more protective. Table 5.2a. Summary

of Acute Dietary

Exposure and Risk for Difenoconazole at the 95th Percentile. Population Subgroup aPAD (mg/kg/day) Exposure (mg/kg/day ) %aPAD Genera l U.S. Population 0.25 0.017715 7 All Infants (< 1 year old) 0.025066 10 Children 1 - 2 years old 0.039605 16 Children 3 - 5 years old 0.031735 13 Children 6 - 12 years old 0.017972 7 Youth 13 - 19 years old 0.008802 4 Adults 20 - 49 year s old 0.013060 5 Adults 50+ years old 0.017260 7 Females 13 - 49 years old 0.013242 5 The bolded %aPAD is the highest. Table 5.2b. Summary

of Chronic Dietary

Exposure and Risk for Difenoconazole. Population Subgroup cPAD (mg/kg/day) Exposure (mg/kg/day ) %cPAD General U.S. Population 0.01 0.001694 17 All Infants (< 1 year old) 0.002403 24 Children 1 - 2 years old 0.004440 44 Children 3 - 5 years old 0.003593 36 Children 6 - 12 years old 0.002041 20 Youth 13 - 19 year s old 0.001360 14Page 28 of 69

Table 5.2b. Summary

of Chronic Dietary

Exposure and Risk for Difenoconazole. Population Subgroup cPAD (mg/kg/day) Exposure (mg/kg/day ) %cPAD Adults 20 - 49 years old 0.001362 14 Adults 50+ years old 0.001538 15 Females 13 - 49 years old 0.001389 14 The bolded %cPAD is the highest.Page 29 of 69

6.0 Residential (Non - Occupational) Exposure/Risk Characterization (HED memo of M. Sahafeyan, 11/09/07, D346591) 6.1 Residential Handler Exposure and Risk Characterization No new residentia l uses are being requested at this time. However, a dults and adolescents may be exposed to difenoconazole from its currently registered use on ornamentals. These risks have been previously

assessed. Below are the results from HED’s previous assessment: HED believes residential pesticide handlers will be exposed to short - term duration (1 - 30 day s) only . The dermal and inhalation (short - term) residential exposure was assessed for "homeowners" mixer/loader/applicator wearing short pants and short - sleev ed shirts as well as shoes plus socks using garden hose - end sprayer, “pump - up” compressed air sprayer, and backpack sprayer. A MOE of 100 is adequate to protect residential pesticide handlers from exposures to difenoconazole. MOEs are >100; therefore are not of concern. A summary of these exposures and risks is presented in Table 6.1. Table 6.1 Summary of Exposure & Risk for Homeowners Applying Difenoconazole. Unit Exposure 1 mg ai/lb handled Applic. Rate 2 lb ai/unit Units Treated 3 Avg. Daily Exposure 4 mg ai/kg bw/day Short - term MOE 5 Mixer/Loader/Applicator Using Garden Hose - end Sprayer Dermal: SS&SP 11 Inhal. 0.017 0.13 lb ai/A 0.5 A/day Dermal: shrtsl&pants 0.00156 Inhal. 0.0000158 790 Mixer/Loader/Applicator Using "Pump - Up" Compressed Air Sprayer Dermal: SS&SP 38 Inhal 0.0027 0.13 lb ai/A 0.5 A/day Dermal: shrtsl&pants 0.00539 Inhal. 0.0000025 230 Mixer/Loader/Applicator Using Backpack Sprayer Dermal: SS&SP 5.1 Inhal. 0.03 0.13 lb ai/A 0.5 A/day Dermal: shrtslv&pants 0.000725 Inhal. 0.000028 1,700 1. Unit Exposures are taken from “PHED SURROGATE EXPOSURE GUIDE”, Estimates of Worker Exposure from The Pesticide Handler Exposure Database Version 1.1, August 1998. Inha l. = Inhalation. Units = mg a.i./pound of active ingredient handled. Unit exposures are also taken from ORETF studies OMA 004,OMA006 and from the Draft Residential SOPs, DECEMBER 1997. SS & SP = short sleeved shirt an d short pants. L S & LP = long sleev ed shirt and long pants. 2. Applic. Rate. = Taken from the draft Inspire ® label. 3. Units Treated are taken the residential SOPs. 4. Average Daily Dose (ADD) = Unit Exposure * Applic. Rate * Units Treated * absorption factor (15.3 % for dermal)  Body Weight (70 kg). 5. NOAEL

= No Observable Adverse Effect Level (1.25 mg a.i./kg bw/day for short - term and intermediate - term dermal and inhalation). 6. MOE = Margin of Exposure = No Observable Adverse Effect Level (NOAEL)  ADD. ADD = dermal + inha lation. With respect to residential post - application exposures, current HED policy (see ExpoSAC minutes from 8/19/99 and 10/11/01) specifies that no significant post - application exposure is anticipated from ornamentals, either by residents or professiona l applicators; therefore, no residential post - application assessment was conducted.Page 30 of 69

7.0 Aggregate Risk Assessments and Risk Characterization Inaccordance with the FQPA, HED must conside r and aggregate (add) 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. 7.1 Acute & Chronic Aggregate Risk Acute and chronic aggregate exposures include food plus drinking water exposures. As demonstrated under Section 5.2. Acute and chronic aggregate risks are not of concern. 7.2 Short - and Intermediate - Term Aggregate Risk Short - Term Aggregate Risk Assessment: Since a common endpoint has been identified for assessment of short - term oral, dermal, and inhalation exposures (changes in body weights and body- weight gains) the short - term aggregate risk assessment c onsidered exposure from food, water, and residential sources. Since the doses corresponding to the identified oral, dermal, and inhalation endpoints were different but the level of concern for all three routes of exposure are identical, the short - term aggregate exposures were calculated using the 1  MOE approach. HED combines chronic dietary (food and water) exposure estimates with residential exposure estimates when conducting short - term aggregate risk assessments. Short - term exposure has been defined as from 1 - 30 day s and HED has concluded that chronic dietary exposure estimates will more accurately

reflect actual dietary

exposure over these time periods than will high - end acute - dietary exposures. The proposed residential scenarios result in exposure t o only adults. Therefore, short term aggregate assessments were not conducted for infants and children. Table 7.2 is a summary of the short - term aggregate exposures and risk estimates. Since the aggregate MOEs are ≥180, short - term aggregate exposure to d ifenoconazole is not of concern. Table 7.2. Short - Term Aggregate Risk Calculations for Handlers Population Target

Aggregate MOE 1 dietary

MOE 2 dermal + inhalation

MOE 3 agg. MOE

(dietary and residential) 4 Youth 13 - 19 years old 100 920 230 180 Adults 2 0 - 49 years old 920 180 Adults 50+ years old 800 180 Females 13 - 49 years old 900 180 1 total uncertainty factor for all routes of exposure is 100x; therefore, the target MOE is 100. 2 dietary MOE = short - term incidental oral NOAEL  chronic dietary exposure. 3 dermal MOE = short - term dermal NOAEL  (dermal + inhalation residential exposure) (see text). 4 aggregate MOE (dietary and residential) = 1  ((1  MOE dietary ) + (1  MOE dermal ) + (1  MOE inhalation)).Page 31 of 69

8.0 Cumulative Risk Characterization/Assessment Difenoconazole is a member of the triazole - containing class of pesticides. Although conazoles act similarly

in plants (fungi) by

inhibiting ergosterol biosy nthe sis, there is not necessarily a relationship between their pesticidal activity and their mechanism of toxicity in mammals. Structural similarities do not constitute a common mechanism of toxicity . Evidence is needed to establish that the chemicals operat e by the same, or essentially

the same, sequence of major biochemical events (EPA, 2002). In conazoles, however, a variable pattern of toxicological responses is found. Some are hepatotoxic and hepatocarcinogenic in mice. Some induce thy roid tumors in rats. Some induce developmental, reproductive, and neurological effects in rodents. Furthermore, the conazoles produce a diverse range of biochemical events including altered cholesterol levels, stress responses, and altered DNA methylation. It is not c learly understood whether these biochemical events are directly connected to their toxicological outcomes. Thus, there is currently

no evidence to indicate that conazoles share common mechanisms of toxicity and EPA is not following a cumulative risk appro ach based on a common mechanism of toxicity for the conazoles. For information regarding EPA’s procedures for cumulating effects from substances found to have a common mechanism of toxicity , see EPA’s website at http://www.epa.gov/pesticides/cumulative. Difenoconazole is a triazole - derived pesticide. This class of compounds can form the common metabolite 1,2,4 - triazole and two triazole conjugates (triazolylalanine and triazolylacetic acid). To support existing tolerances and to establish new tolerances for triazole - derivative pesticides, including difenoconazole, U.S. EPA conducted a human health risk assessment for exposure to 1,2,4 - triazole, triazolylalanine, and triazolylacetic acid resulting from the use of all current and pending uses of any

triazo le - derived fungicide. The risk assessment is a highly conservative, screening - level evaluation in terms of hazards associated with common metabolites (e.g., use of a maximum combination of uncertainty factors) and potential dietary and non - dietary

exposur es (i.e., high end estimates of both dietary and non - dietary

exposures). In addition, the Agency retained the additional 10X FQPA safety factor for the protection of infants and children. The assessment includes evaluations of risks for various subgroups , including those comprised of infants and children. The Agency ’s complete risk assessment is found in the propiconazole reregistration docket at http://www.regulations.gov, Docket I dentification (ID) Number EPA HQ - OPP - 2005 - 0497. 9.0 Occupational Exposur e/Risk Pathway (HED memo of J. Miller, 09/14/09, D361054 ) 9.1 Occupational Handler Exposure and RiskPage 32 of 69

Handler Exposure The proposed uses associated with this action are for the use of difenoconazole (Inspire TM Fungicide: EPA Reg. No. 100 - 1262) on Brassica leafy , bulb, and cucurbit vegetables, Citrus fruits, Grapes, Pistachios, and Tree Nuts. For this registration action, applications using aerial, ground, chemigation, and airblast equipment are allowed. Ba sed on the number of seasonal applications indicated on this product label, and information provided by

the registrant, handler exposures are expected to be short - term in duration. The quantitative exposure/risk assessment developed for commercial handler s is based on the following exposure scenarios:

 Open Mixing/L oading: Groundboom, Aerial, Chemigation, and Airblast; (Emulsifiable Concentrate formulation to Brassica leafy , bulb, and cucurbit vegetables, Citrus fruits, Grapes, Pistachios, and Tree Nuts).

 Open Mixing/L oading/Applying: Groundboom (Emulsifiable - Concentrate formulation to Brassica leafy , bulb, and cucurbit vegetables, Citrus fruits, Grapes, Pistachios, and Tree Nuts).

 Applying: Groundboom, Aerial, Chemigation, Airblast; (Emulsifiable - Concentrate formulation to Brassica leafy , bulb, and cucurbit vegetables, Citrus fruits, Grapes, Pistachios, and Tree Nuts). No chemical - specific handler exposure data were submitted in support of this registration. It is the policy of the HED to use data from the Pesticide Handlers Exposure Database (PHED) Version 1.1 as presented in PHED Surrogate Exposure Guide (8/98) to assess handler exposures for regulatory

actions when chemical - specific monitoring data are not available (HED Science Advisory Council for Exposure Standard Operating Procedure #7, dated 1/28/99). The results of the occupational exposure and risk assessment indicate that risks are not of concern (MOE ≥100) while wearing label - specified PPE. Data and Assumptions for Handler Exposure Scenarios Unit Exposures:

 Chemical - specific data for assessing exposure during pesticide handling activities were not submitted to the Agency in support of this Section 3 application. It is HED policy to use data from the Pesticide Handlers Exposure Database (PHED) Version 1.1 to assess handler exposures for regulatory actions when chemical - specific data are not available (HED Science Advisory

Council for Exposure, SOP Number .007, January 1999). Area Treated:Page 33 of 69

 The treatable acreage for the crops listed in table 1, varied according to the broadcast equipment used. Ple ase see [Appendix A: Occupational - Agricultural Handler], for details. Note: acreage taken from: (HED Exposure Science Advisory Committee SOP Number 9.1). Application Rate :  (Inspire TM Fungicide: EPA Reg. No. 100 - 1262) The proposed product ( In spire TM Fungi cide: EPA Reg. No. 100 - 1262) is an emulsifiable concentrate (EC) containing 23.2% active ingredient. This formulation is distributed utilizing ground boom, aerial, broadcast and chemigation equipment. The application rates for all distribution equipment range from a minimum of 0.07 pounds per acre per application to a maximum of 0.114 pounds per acre per application. Exposure Duration :  Itis unlikely

that pesticide handlers would be exposed continuously for 30 day s or more. However, because the shor t - term and intermediate - term toxicological endpoints are the same ( 1.25 mg/kg bw/day ) , the assessment of short - term exposure and risk is adequate to describe risk from an intermediate - term exposure should that occur. MOEs for the short term scenarios have been estimated within. Body Weight:

 The average adult body weight of 70 kg was used for estimating exposure and risk. Handler Exposure Calculations Handler risks were calculated using the Margin of Exposure (MOE) which is a ratio of the calculate d daily

dose to the NOAELof concern. Daily dose values are calculated using relevant application parameters (i.e., rate and area treated) along with unit exposures. Exposures are then adjusted for body

weight and absorption factors as appropriate to cal culate dose levels. Daily Exposure : The daily

exposures were calculated as described below.

 Daily exposure = (Unit exposure x application rate x Daily Area Treated) Where: Daily

Exposure = Amount (mg ai/day ) deposited on the surface of the Ski n that is available for dermal absorption or amount inhaled that is available for inhalation absorption; Unit Exposure = Unit exposures (mg ai/lb ai) derived from August 1998 PHED data, or other appropriate data; Application Rate = lbs ai per acre ;Page 34 of 69 Daily Area Treated = acres per day Daily Dose: The daily

dose (inhalation or dermal) was calculated by adjusting the daily

dermal and inhalation exposure values by body weight and accounting for dermal or inhalation absorption. For adult handle rs using acetochlor, an average body weight of 70 kg was used.  Daily Dose = (Daily exposure x absorption factor)/ Bodyweight Where: Daily

Dose = Absorbed dose (mg ai./kg body weight/day

); Daily Exposure = Amount (mg ai/day ) deposited on the surface of the skin or inhaled; Absorption Factor = 100% for inhalation , 15.3% for dermal Body Weight = 70 kg Margins of Exposure : The daily doses were then compared to the NOAELs to assess the risk as an MOE. The MOEs were calculated using the formula below:

 MOE = NOAEL/Dose Where: MOE = Margin of Exposure (unit less) Dose = mg/kg/day NOAEL = No Observed Adverse Effects Level (mg/kg/day ) Handler Exposure Summary Exposure and risk assumptions and MOEs for occupational handlers (Agricultural use) are summarized in Table 9.1.Page 35 of 69

Note: 1 Handler Exposure Database Version 1.1, Surrogated Exposure guide August 1998 Inhal. = Inhalation. Units = mg a.i./pound of active ingredient handled. 2. Appl. Rate. = Taken from product labeling. 3. Units Treated are taken from “ Standard Values for Daily Acres Treated in Agriculture”; ExpoSAC SOP No. 9.1. Revised 4. Average Daily Dose (ADE) = Unit Exposure * Applic. Rate * Units Treated * DA  70 kg Body Weight 5. MOE = Margin of Exposure = NOAEL  ADE. NOAEL = 1 .25 mg/kg bw/day 6. (EC) = Emulsifiable Concentrate 7. BL = Baseline (single layer clothing with no gloves) Table 9.1: Summary of Exposure & Risk to Occupational Handlers Unit Exposure 1 Appl. Rate 2 lb ai/unit Units

Treated 3 Avg. Daily

Exposure 4 mg ai/kg bw/day Baseline + Gloves MOE 5 Dermal mg ai/lb handled Inhal.

μg ai/lb handled Dermal + Inhalation BL 7 BL/Gloves BL 7 BL/Gloves Open Mixer/Loader “Aerial”

– Liquid 2.9 0.023 Inhal. 1.2 0.114 lb ai/A 350 A/day Dermal .0020 Inh al.

.0007 4.9 460 Open Mixer/Loader “Groundboom” Open Cab

– Liquid 2.9 0.023 Inhal. 1.2 0.114

lb ai/A 80 A/day Dermal .0005 Inhal.

.0002 22 2200 Open Mixer/Loader/Applicator “Groundboom” Open Cab

– Liquid 0.37 0.057 1.3 0.114 lb ai/A 80 A/day Dermal .0011 Inhal.

.00016 170 960 Open Mixer/Loader “Airblast”

– Liquid 2.9 0.023 Inhal. 1.2 0.114

lb ai/A 40 A/day Dermal .00023 Inhal.

.000008 43 4100 Open Mixer/Loader “Chemigation”

– Liquid 2.9 0.023 Inhal. 1.2 0.114

lb ai/A 350 A/day Dermal .0020 Inhal.

.0007 4.9 460 Applicator “Aerial”

– Closed cockpit (EC) 6 0.005 0.0022 Inhal. 0.07 0.114

lb ai/A 350 A/day Dermal .0002 Inhal.

.00004 2600 5400 Applicator “Groundboom”

– Open Cab (E C) 0.014 0.014 Inhal. 0.074 0.114

lb ai/A 80 A/day Dermal .0003 Inhal.

.00010 3300 3300 Applicator “Airblast”

– Open Cab (EC) 0.36 0.24 Inhal. 4.5 0.114

lb ai/A 40 A/day Dermal .0024 Inhal.

.0003 320 470Page 36 of 69

Note: Margins of Exposure (MOEs) for “Baseline” Open Mixer/L oader involving Aerial, Groundboom, Airblast, and Chemigation are of conce rn (MOE ≤ 100), however label specific directions call for PPE equipment ( Gloves ). Under these circumstances which are noted in table #4, MOEs are not of concern. 9.2 Occupational Postapplication Expo sure and Risk HED uses the term “post - application” to describe exposures to individuals that occur as a result of being in an environment that has been previously treated with a pesticide (also referred to as re - entry

exposure). HED believes that there are distinct job functions or activities that occur in previously treated areas. These job functions (e.g., the kinds of jobs to cultivate a crop), the nature of the crop or target that was treat ed, and the how chemical residues degrade in the environment can cause exposure levels to differ over time. Each factor has been considered in this assessment. HED in conjunction with the Agricultural Re - entry Task Force (ARTF) has identified a number of post - application agricultural activities that may occur and which may

result in post - application exposures to pesticide residues. HED estimated the post - application exposure for two uses that are considered to have the highest Transfer Coefficients (TC): Note: In this assessment, there were no chemical - specific residue dissipation data are available, in the absence of data, HED ty pically uses a generic dissipation model to complete risk calculations. Model calculation specifics are noted below. Daily E xposure: The next step in the risk assessment process was to calculate dermal exposures on each day

after application using the following equation. DE (t) (mg/day) = (TR (t) (

 g/cm 2 ) x TC (cm 2

/hr) x Hr/Day)/1000 (

 g/mg) Where: DE(t) = Daily exposure or amount deposited on the surface of the skin at time (t) attributable for activity in a previously

treated area, also referred to as potential dose (mg ai/day ); TR(t) = Transferable residues that can either be dislodgeable foliar or turf

transferabl e residue at time (t) where the longest duration is dictated by

the decay

time observed in the studies ( g/cm 2 ); TC = Transfer Coefficient (cm 2 /hour); hr/day = Exposure duration meant to represent a ty pical workday

(hours). Daily Dose and Margins of Exposure: Once daily exposures are calculated, the calculation of daily

absorbed do se and the resulting Margin of Exposures use the samePage 37 of 69

algorithms that are described above for the handler exposures (See Section 5.1.3). These calculations are completed for each day or appropriate block of time after application. Post - application Exposu re Summary For all post - application activities concerning this registration action, short - term occupational risks are below HED’s level of concern (i.e., MOEs > 100) at day 0. Exposure, risk assumptions and MOEs for occupational post - application exposure s (Agricultural use) are summarized in Table 9.2.

1 Maximum application rate from proposed label 2 DAT = Days after treatment needed to reach the LOC of 100; DAT 0 = the day of treatment/ assumed to be approx. 12 hours. 3 DFR (μg/cm2 ) = dislodgeable foliar residues corresponding to DAT, based on 20% of application rate. 4 TC (cm2 /hr) = transfer coefficients and associated activities from ExpoSAC Policy Memo #003.1, 8/17/2000. 5 MOE = MOE on the corresponding DAT. MOE = NOAEL (1.25 (mg/kg/day) / Daily Dose. 6 (EC) = Emulsifiable Concentrate formulation Table 9.2. Summary of Estimated Post - application MOEs for Agricultural Crops Crop Application

Rate (lb ai/A) 1 DAT 2 DFR 3

(μg/cm 2 ) TC 4

(cm 2 /hr) Activity 4 Short - Term MOE 5 Brassica Leafy, Bulb, Fruiti ng, and Cucurbit vegetables ( 6 EC) 0.114 0 0.256 100 scouting immature plants 2800 1500 scouting mature plants 190 Non - bearing Citrus, Grapes, and ( 6 EC) 100 scouting immature plants 2800 1500 harvesting, pruning 190 Tree Nuts ( 6 EC) 500 scouting immature plants 560 2500 harvesting, pruning 110Page 38 of 69

10.0 Data Needs and Label Recommendations Residue Chemistry 860.1200 Directions for Use

– Pertains to Di fenoconazole only

 The labels for the 2.08 lb/gal EC formulation (EPA Reg. No. 100 - 1262), the 2.08 lb/gal MAIEC formulation (EPA Reg. No. 100 - 1312), the 1.05 lb/gal MAI SC formulation (EPA Reg. No. 100 - 1313), and the 0.73 lb/gal MAI EW formulation (EPA Re g. No. 100 - 1317) must be revised to specify that no adjuvants may

be used when the products are applied to almonds, filberts (hazelnuts), pecans, pistachios, and tree nuts.

 The 7 - day

minimum retreatment interval proposed for almond on the label for the 2. 08 lb/gal MAIEC formulation (EPA Reg. No. 100 - 1312) is not supported by the residue data. The label for this product must be revised to specify a minimum retreatment interval of 14 days for all tree nuts (including almond).

 If the petitioner intends to support use on turnip greens under Brassica leafy vegetables, this commodity should be added to the list of Brassica leafy vegetables, and a separate tolerance must be proposed; otherwise, the restriction against feeding treated turnip roots and specifying that only turnip varieties harvested for their leaves may be treated should be removed from the label for the 0.73 lb/gal MAIEW formulation with cy prodinil (EPA Reg. No. 100 - 1317).

 The label for the 1.05 lb/gal MAI SC formulation (EPA Reg. No. 100 - 1313) must be revised to reflect a 1 - day PHIfor Brassica leafy

vegetables.

 The labels for the 1.05 lb/gal MAI SC formulation (EPA Reg. No. 100 - 1313) and the 0.73 lb/gal MAIEW formulation (EPA Reg. No. 100 - 1317) should be amended to include the following tank mix restrictions: All directions for use, crops/sites, use rates, dilution ratios, precautions, and limitations which appear on the tank mix product label be observed. The label dosage for the tank mix partner is not to be exceeded, and the most restric tive label precautions and limitations are to be followed. In addition, the labels for these products should be revised to remove contradictory

instructions for application equipment ty pes under citrus (both labels) and cucurbit vegetables (100 - 1317 only ) . 860.1550 Proposed Tolerances

 The proposed tolerances should be revised to reflect the recommended tolerance levels and correct commodity definitions as specified in Table 14. HED recommends that conditional registrations for the requested uses of the ECPage 39 of 69

and SC formulations of difenoconazole on bulb vegetables, Brassica leaf vegetables, citrus fruits, cucurbit vegetables, pistachios, tree nuts, and grapes; and for the requested uses of the EW formulation of difenoconazole on almonds, pistachios, Brassic a leafy vegetables, and bulb onions, may be converted to unconditional registration upon submission of the following residue chemistry data: 860.1340 Residue Analy

tical Methods Li vestock Commodities:  The requirement for additional information concerning the ILV of method REM 147.07 that was previously identified in DP# 340379 (8/9/07, W. Wassell and M. Sahafeyan) is a requirement for unconditional registration for this action. The following additional information is needed for the ILV study to fulfill the requirements of 860.1340 pertaining to ILVs [see 860.1340(c)(6)(v)]: (1) the number of trials required by the ILV laboratory

to achieve the reported recovery values; (2) a discussion of any steps considered by

the ILV laboratory

to be critical ( i.e. , s teps where little variation is allowable or directions should be followed precisely

); (3) the number of worker - hours required to complete one set of samples; (4) the number of calendar day s required for one set of samples; and (5) a description of any

cont act between the independent laboratory and the method developers or others familiar with the method, including the reasons for the contact, any

changes in the method that resulted, and the time of this communication with respect to the progress of the conf irmatory trial ( i.e., after the first set, during the second set, etc.). 860.1380 Storage Stability

 Supporting storage stability data for the triazole metabolites are required to support the storage conditions (frozen) and intervals (up to 24.8 months) of raw agricultural and processed commodity samples collected for the studies reviewed herein. No such supporting storage stability data were provided or identified in the subject submissions; however, the U.S. Triazole Task Force (USTTF), whose members include Sy

ngenta Crop Protection, Inc. among others, has submitted a multi - ye ar storage stability study for the triazole metabolites in various crop matrices and processed commodities (MRID 47606601) which is currently under review in HED (D363016).

 The r equirement for storage stability data for cattle commodities that was previously

identified in DP# 340379 (8/9/07, W. Wassell and M. Sahafeyan) is a requirement for unconditional registration for this action. Data should be submitted depicting the stabili ty of residues of difenoconazole and CGA 205375 in milk and cattle tissues during frozen storage for up to 10 months for milk and 9 months for tissues. The studies cited by the petitioner (report numbers ABR 93012 and 202/99), which contain storage stabil ity data for difenoconazole and CGA 205375, should be submitted.Page 40 of 69

Note: Although not required for this action, since there are no poultry feedstuff associated with the proposed uses, the requirement for storage stability data for poultry commodities that was previously identified in DP# 340379 (8/9/07, W. Wassell and M. Sahafeyan) remains outstanding. As a reminder, data should be submitted depicting the stability of residues of difenoconazole and CGA 205375 in egg and poultry tissue samples during frozen storage for up to 7 months for egg and 6 months for tissue samples. The studies cited by the petitioner (report numbers ABR - 93012 and 202/99), which contain storage stability data for difenoconazole and CGA 205375, should be submitted. 860.1850 Confined Accumulation in Rotational Crops

 The requirement for an additional confined rotational crop study that was previously

identified in DP# 344680 (11/5/07, M. Sahafeyan) is a requirement for unconditional registration for this action. A confined rotational crop study reflecting phenyl - ring labeling must be conducted at 1x the proposed maximum seasonal foliar application rate (0.46 lb ai/A). Toxicity

 Immunotoxicity

study (870.7800) Inaccordance with Part 158 Toxicology Data requirements, an immunotoxicity study (870.7800) is required for difenoconazole. In the absence of specific immunotoxicity studies, EPA has evaluated the available difenoconazole toxicity data to determine whether an additional database uncertainty factor is needed to account for pote ntial immunotoxicity . There are no indications in the available studies that organs associated with immune function, such as the thy mus and spleen, are affected by difenoconazole, and difenoconazole does not belong to a class of chemicals (e.g., the organ otins, heavy metals, or halogenated aromatic hydrocarbons) that would be expected to be immunotoxic. Therefore, EPA does not believe that conducting immunotoxicity testing will result in a point of departure lower than those already selected for difenocon azole risk assessment, and an additional database uncertainty factor is not needed to account for the lack of this study . ORE

 nonePage 41 of 69

11.0 References: 1. HED memo of B. Cropp - Kohlligian, 09/17/09, “ Difenoconazole. Application for Amended Section 3 Registration to Add Uses on Bulb Vegetables, Brassica Leafy Vegetables, Cucurbit Vegetables, Citrus Fruits, Grapes, Pistachios, and Tree Nuts. Submission of Residue Analy tical Methods Data in Response to DP#340379. Summary of Analy t ical Chemistry

and Residue Data.” D 361054 and 362648. 2. HED memo of T. Morton, 09/22/09, “ Difenoconazole. Acute and Chronic Aggregate Dietary

Exposure and Risk Assessments for the Section 3 Registration Request for Bulb Vegetables, Brassica Leafy Vege tables, Cucurbit Vegetables, Citrus Fruit, Grape, Pistachios, and Tree Nut”. D367383. 3. HED memo of J. Miller, 9/14/09, “Occupational and Residential Risk Assessment to Support the Section 3 Request for Registration of Difenoconazole on Bulb Vegetable s, Brassica Leafy Vegetables, Cucurbit Vegetables, Citrus Fruits, Grapes, and Tree Nuts”. DP barcode 361054. 4. EFED memo of I. Maher, 05/28/09, Difenoconazole (Parent Only ) Drinking Water Assessment in Support of New Use Registration Action for Bulb V egetables, Brassica (Cole) Leafy Vegetables, Cucurbit Vegetables, Citrus Fruit, Grapes, and Tree Nuts”. 5. HED memo of M. Sahafeyan, 11/09/09, “PP#: 6F7115. Difenoconazole in/on Fruiting Vegetables, Pome Fruit, Sugar Beets, Tuberous and Corm Vegetables , and Imported Papaya. Health Effects Division (HED) Revised Risk Assessment . DP#: 346591. PC Code: 128847. Decision#: 371264”. D346591. 6. HED memo of T. Morton, 08/13/09, “ Common Triazole Metabolites: Updated Aggregate Human Health Risk Assess ment to Address Tolerance Petitions for Difenoconazole”. D367861 . 7. HED memo of. of T. Morton, 08/13/09, “ Common Triazole Metabolites: Updated Dietary

(Food + Water) Exposure and Risk Assessment to Address The Tolerance Petitions for Difenoconazole”. D367860 .Page 42 of 69

12.0 Tolerance Summary

Table 12. Tolerance Summary for Difenoconazole. Commodity Proposed

Tolerance (ppm) Recommende

d Tolerance (ppm) Comments; Correct

Commodity Definition Almond, hulls 7 7.0 Brassica, head & stem, subgroup 5A 1.9 1. 9 Brassica, head and stem, subgroup 5A Brassica, leafy

green, subgroup 5B 30 35 Brassica, leafy greens, subgroup 5B Citrus, dried pulp 2.5 2.0 Citrus, oil 28 25 Fruit, citrus, group 10 0.6 0.60 Grape 4 4.0 Grape, raisin 14 6.0 Nut, tree, group 14 0.03 0.03 Onion, bulb, subgroup 3 -

07A 6 1 0.20 Onion, green, subgroup 3 -

07B 0.15 1 6.0 Pistachios 0.03 0.03 Pistachio Vegetable, cucurbit, group

9 0.7 0.70 1 The proposed tolerances for bulb and green onions appear to have been transposed by the petitioner.Page 43 of 69

13.0 Appendices

Appendix 1 : Acute Toxicity Data on Difenoconazole Technical Table 13.0a Acute Toxicity Profile - Difenoconazole Guideline No. Study Type MRID(s) Results Toxicity Category 870.1100 Acute oral rat 42090006 LD 50 = 1450 mg/kg III 870.1200 Acute dermal rat 42090007 LD 50 > 2010 mg/kg III 870.1300 Acute inhalation rat 42090008 LC 50 > 3.3 mg/L III 870.2400 Acute eye irritation rabbit 42090009 Mild oc ular irritation reversible in 7 days III

870.2500 Acute dermal irritation rabbit 42090010 Slight irritation IV 870.2600 Skin sensitization mouse 42090011, 42710004 Negative N/APage 44 of 69 Appendix 2: Subchronic, Chronic and Other Toxicity Profile Table 13.0b Subchronic, Chronic and Other Toxicity Profile of Difenoconazole Guideline No. Study Type MRID No. (year)/ Classification /Doses Results 870.3100 90 - Day oral

toxicity (rat) 42090022 (1987)

Acceptable/guideline 0, 20, 200, 750, 1500 or 3000 ppm 0, 1, 10, 37.5, 75 and 150 mg/kg/d NOAEL = 20 ppm (1 mg/kg/day) LOAEL = 200 ppm (10 mg/kg/day) based on the 10% decrease in body w eight in the 200 ppm females (as we ll as a negative trend in feed consumption) and Increases in absolute liver weights in both sexes 870.3100 90 - Day oral

toxicity (mouse) 42090021 (1987)

Minimum/guideline 0 , 20, 200, 2500, 7500 or 15,000 ppm M: 0, 2.9, 30.8, 383.6, 1125 and 2250 mg/kg/d F: 0, 4.1, 41.5, 558.9, 1125 and 2250 mg/kg/d NOAEL = 20 ppm (2.9 mg/kg/day) LOAEL = 200 ppm (30.8 mg/kg/day) based on body we ight changes & liver histopathology.

870.3150 26 - Week oral

toxicity 42090012 (1987)

Minimum/ guideline 0, 100, 1000, 3000 or 6000 ppm M: 0, 3.6, 31.3, 96.6 and 157.8 mg/kg/d F: 0, 3.4, 34.8, 110.6 and 203.7 mg/kg/d NOAEL = 3000 ppm (31.3 mg/kg/day in males/34.8 mg/kg/day in females) LOAEL = 6000 ppm ( 96.6 mg/kg/day in males/110.6 mg/kg/day in females) , based primarily on microscopic examination of CGA 169374 - related lenticular cataracts.

870.3200 21/28 - Day dermal

toxicity (rat) 42090013 (1987)

Minimum/ guideline 0, 10, 100 and 1000 mg/kg/d NOAEL = 10 mg/kg/day LOAEL = 100 mg/kg/day based on statistically significant decrements in body weight, body weight gain, and food consumption. 870.3200 21/28 - Day dermal

toxicity (rat) 46950310 (2000)

Acceptable/ guideline 0, 10, 100 and 1000 mg/kg/d NOAEL (syste mic) = 1000 mg/kg/day LOAEL (systemic) was not determined. NOAEL (dermal) = 100 mg/kg/day LOAEL (dermal) = 1000 mg/kg/day based on hyperkeratosis at the skin application site.Page 45 of 69

Table 13.0b Subchronic, Chronic and Other Toxicity Profile of Difenoconazole Guideline No. Study Type MRID No. (year)/ Classification /Doses Results 870.3700a Prenatal

developmental in (rat) 42090016, 42710007

(1987) Minimum/ guideline 0, 2, 20, 100 or 200 mg/kg/d from GD 6 - 15 (nominal doses differed widely from theoretical, this required altering NOAEL/LOAEL values) Materna l NOAEL = 16 mg/kg/day LOAEL = 85 mg/kg/day based on decreased body we ight gain and food consumption. Dev elopm enta l NOAEL = 85 mg/kg/day LOAEL = 171 mg/kg/day based on alterations in fetal ossification.

870.3700b Prenatal

developmental in (rabbit) 42090017, 42710008

(1987) Minimum/ guideline 0, 1, 25 or 75 mg/kg/d from GD 7 - 19 Materna l NOAEL = 25 mg/kg/day LOAEL = 75 mg/kg/day based on decreased body we ight gain and food consumption. Developm enta l NOAEL = 25 mg/kg/day LOAEL = 75 mg/kg/day based on nonsignificant increases in postimplantation loss and resorptions/doe and a significant decrease in fetal wei ght. 870.3800 Reproduction and

fertility effects (rat) 42090018 (1988)

Minimum/ guideline 0, 25, 250 or 2500 ppm 0, 1.25, 12.5 and 125 mg/kg/d Parental/Systemic NOAEL = 25 ppm (1.25 mg/kg/day) LOAEL = 250 ppm (12.5 mg/kg/day) based on reductions (stati stically nonsignificant) in body weight gain which appear to be part of a dose - related trend days 70 - 77 prior to mating, days 0 - 7 of gestation, and days 7 - 14 of lactation Reproductive NOAEL = 25 ppm (1.25 mg/kg/day) LOAEL = 250 ppm (12.5 mg/kg/day) based o n a significant reduction in the body weight of F1 male pups at day 21 in the 250 ppm group. 870.4100b Chronic toxicity

(dog) 42090012, 42710005

(1988) Minimum/ guideline 0, 20, 100, 500 or 1500 ppm M: 0, 0.71, 3.4, 16.4 and 51.2 mg/kg/d F: 0, 0.63, 3.7, 19.4 and 44.3 mg/kg/d NOAEL = 100 ppm (3.4 mg/kg/day in males/3.7 mg/kg/day in females) LOAEL = 500 ppm (16.4 mg/kg/day in males/19.4 mg/kg/day in females) , based on significant inhibition of body weight gain in females.Page 46 of 69

Table 13.0b Subchronic, Chronic and Other Toxicity Profile of Difenoconazole Guideline No. Study Type MRID No. (year)/ Classification /Doses Results 870.4200 Carcinogenicity

(rat) 42090019, 42710010

(1989) Minimum/ guideline 0, 10, 20, 500 or 2500 ppm M: o, 0.48, 0.96, 24.12 and 123.7 mg/kg/d F: 0, 0.64, 1.27, 32.79 and 169.6 mg/kg/d NOAEL = 20 ppm (0.96 mg/kg/day in males/1.27 mg/kg/day in females) LOAEL = 500 ppm (24.1 mg/kg/day i n males/ 32.8 mg/kg/day in females) based on reductions in cumulative body weight gains in the 500 and 2500 ppm groups. No evidence of carcinogenicity

870.4300 Carcinogenicity

(mouse) 42090015, 42710006

(1989) Minimum/ guideline 0, 10, 30, 300, 2500 or 3000 ppm M: 0, 1.51, 4.65, 46.29, 423.1 and 818.9 mg/kg/d F: 0, 1.9, 5.63, 57.79 and 512.6 mg/kg/d NOAEL = 30 ppm (4.7 mg/kg/day in males/5.6 mg/kg/day in females) LOAEL = 300 ppm (46.3 mg/kg/day in males/57.8 mg/kg/day in females) based on reductions in the cumulative body weight gains in the 300, 2500 & 4500 ppm groups. Evidence of carcinogenicity (liver adenom a/carcinom a in both sexes) 870.5100 In vitro bacterial

gene mutation (Salmonella typhimurium/ E. coli) / mammalian activation gene mutation assay 42090019, 42710010

(1989) Minimum/ guideline 340 - 5447 μg/plate; 85 - 1362 μg/plate (repeat assay with TA 1537 and TA98) There w ere sufficient and valid data to conclude that CGA 169374 technical was negative in the microbial gene mutation assay.

870.5300 in vitro mammalian

cell gene mutation assay in mouse lymphoma cells 42090024 (1986)

Unacceptable/ guideline No conclusion can be reached from the three nonactivated and two S9 activated mouse lymphoma forward mutation assays conducted with difenoconazole technical. The study was seriously compromi sed. 870.5375 In vitro

Mammalian Cytogenetics (chromosomal aberrations) a ssay in Chinese hamster CHO cells 46950319 (2001)

Acceptable/ guideline 0, 21.99, 27.49, or 34.36 μg/mL ( - S9) 0, 34.36, 53.69 or 67.11 μg/mL (+S9) There was evidence of a w eak induct ion of structural chromosomal aberrations over background in the presence of S9 - mix.Page 47 of 69

Table 13.0b Subchronic, Chronic and Other Toxicity Profile of Difenoconazole Guideline No. Study Type MRID No. (year)/ Classification /Doses Results 870.5375 In vitro

Mammalian Cytogenetics (chromosomal aberrations) a ssay in Chinese hamster CHO cells 46950321 (2001)

Acceptable/ guideline 0, 26.3, 39.5 or 59.3 μg/mL ( - S9) 0, 11.7 or 17.6 μg/mL (+S9) There was evidence of a w eak induction of structural chromosomal aberrations over background.

870.5375 In vitro

Mammalian Cytogenetics (chromosomal aberrations) a ssay in human lymphocytes 46950323 (2001)

Acceptable/ guide line 0, 5, 30 or 75 μg/mL ( - S9) 0, 5, 30 or 62 μg/mL (+S9) There was no evidence of structural chromosomal aberrations induced over background.

870.5385 In vivo mammalian

chromosomal aberration test Assay in Mice 42090023 (1986)

Unacceptable/guideline 2 50, 500 or 1000 mg/kg There was no evidence of a cytotoxic effect on the target organ or significant increase in the frequency of nuclear anomalies (micronuclei). However, the study wa s compromised. 870.5395 In vivo mammalian

cytogenetics - erythrocyte micronucleus assay in mice 41710011 (1992)

Acceptable/guideline Doses up to 1600 mg/kg Mice bone marrow - No increase in micronucleated polychromatic erythrocytes occurred with CGA - 1 69374 (91.2% a.i). 870.5550 Unscheduled DNA

Synthesis in Mammalian Cells in Culture 4210012 (1992)

Acceptable/ guideline Doses up to 50 μg/mL CGA - i69374 tech. (92.2% a.i.) was considered to be negative in the unscheduled DNA synthesis assay in rat primary hepatocytes as measured by an autoradiographic method at concentrations up to 50.0 μg/mL. 870.5550 Unscheduled DNA

Synthesis in Mammal ian Cells in Culture 42090027 (1985)

Unacceptable/ guideline 0.25 - 31.25 μg/mL No conclusion can be reached from the unscheduled DNA synthesis (UDS) primary rat hepatocyte assay conducted with difenoconazole technical at concentrations ranging from 0.25 t o 31.25 μg /mL. The sensitivity of the study was severely compromised. 870.5550 Unscheduled DNA

Synthesis in Mammalian Cells in Culture 42090026 (1985)

Unacceptable/ guideline 0.08 - 10 μg/mL No conclusion can be reached from the unscheduled DNA synthesis ( UDS) human fibroblast assay conducted with difenoconazole tech. at conc. ranging from 0.08 to 10 μg /mL.Page 48 of 69

Table 13.0b Subchronic, Chronic and Other Toxicity Profile of Difenoconazole Guideline No. Study Type MRID No. (year)/ Classification /Doses Results 870.6200a Acute neurotoxicity

screening battery 46950327 (2006)

Acceptable/ guideline 0, 25, 200 or 2000 mg/kg/d NOAEL (M) = 25 mg/kg/day LOAEL (M) = 200 mg/kg/day based on reduced fore limb grip strength in males on day 1 and increased mo tor activity on Day 1 . NOAEL (F) = 200 mg/kg/day LOAEL (F) = 2000 mg/kg/day based on decreased body weight, the following clinical signs: upward curvature of the s pine, tip - toe gait, decreased activity, piloerection and sides pinched in and decreased motor activity. 870.6200b Subchronic

neurotoxicity screening battery 46950329 (2006)

Acceptable/ guideline 0, 40, 250, or 1500 ppm M; 0, 2.8, 17.3 or 107.0 mg/kg/d F: 0, 3.2, 19.5, or 120.2 mg/kg/d NOAEL (M) = 40 ppm (2.8 mg/kg/day) LOAEL (M) = 250 ppm (17.3 mg/kg/day) based on decreased hind limb strength. NOAEL (F) = 250 ppm (19.5 mg/kg/day) LOAEL (F) = 1500 (120.2 mg/kg/day) based on decreased body w eight, body we ight gain and food efficiency. 870.7485 Metabolism and

pharmacokinetics (rat) 42090028 (1990)

Acceptable/ guideline 14 daily doses of 0.5 or 300 mg/kg The absorption, distribution, metabolism, and excretion of CGA 169374 w ere studied in groups of ma le and female Sprague - Dawley rats. Animals were administered a single oral gavage dose of 0.5 or 300 mg/kg [ 14 C]CGA - 169374, or 0.5 mg/kg unlabeled GGA - 169374 by gavage for 14 days follow ed by a single gavage dose of 0.5 mg/kg [ 14 C)CGA - 169374 on day 15. Th e test compound was labeled with C 14 at either the phenyl or triazole ring. 870.7485 Metabolism and

pharmacokinetics (rat) 42090031 (1988)

Acceptable/ guideline 0.5 or 300 mg/kg These studies indicate that distribution, metabolism, and elimination of CGA - 169374 w ere not sex related. There was a slight dose difference in the metabolism and elimination of CGA - 169374. In phenyl and triazole labeling studies, fecal excretion of radioactivity was higher in the high dose animals compared to the low dose animal s, and an additional metabolite was found in the feces of the hi gh dose animals compared to the low dose animals. There was no major difference in the distribution and excretion of radioactivity with labeling at the phenyl and triazole ring positions, howe ver, there we re some different metabolites identified. The studies also showed that administration of 0.5 and 300 mg/kg CGA - 169314 did not induce any treatment related clinical effects.Page 49 of 69

Table 13.0b Subchronic, Chronic and Other Toxicity Profile of Difenoconazole Guideline No. Study Type MRID No. (year)/ Classification /Doses Results 870.7485 Metabolism and

pharmacokinetics (rat) 420710013, 42710014

(1990) Acceptable/ guideline 0.5 or 300 mg/kg These two studies described the absorption, distribution, and excretion as the pharmacokinetics and isolated and identified urinary metabolites. Issues raised in the previous supplementary studies were answere d. In conjunction with these studies, the previous studies are upgraded. 870.7485 Metabolism and

pharmacokinetics (rat) 42090029 (1987)

Acceptable/ guideline [14C]CGA - 169374 w as rapidly and extensively distributed. metabolized, and excreted in rats for all dosing regimens. The extent of absorption is undetermined pending determination of the extent of biliary excretion. The 4 - day recoveries were 97.4 - 107.75% of the administered dose for all dosing groups. The elimination of radioactivity in the feces (7 8.06 - 94.61% of administered dose) and urine (8.48 - 21.86%) w ere almost comparable for all oral dose groups, with slightly higher radioactivity found in the feces of the high dose group than the low dose groups. This was probably due to biliary excretion, p oor absorption or saturation of the metabolic pathw ay. The radioactivity In the blood peaked at about 24 - 48 hours for all dosing groups. Half - lives of elimination appear to be approximately 20 hours for the low dose groups and 33 - 48 hours for the high do se group. The study results also indicate that CGA - 1 69374 and/or its metabolites do not bioaccumulate to an appreciable extent following oral exposure since all the tissues contained negligible levels (<1%) of radioactivity 7 days postexposure. 870.7485 Metabolism and

pharmacokinetics (rat) 42090030 (1987)

Acceptable/ guideline The metabolism of CGA - 169374 appears to be extensive because the metabolites accounted for most of the recovered radioactivity in the excreta. Three major metabolites were identi fied in the feces (i.e., A, B, and C). Two of the metabolites were separated into isomers (i.e., A1, A2, B1, and B2). Metabolite C was detected only In the high dose groups, indicating that metabolism of CGA - 169374 is dose related and involves saturation o f the metabolic pathway. Free triazole metabolite was dete6ted in the urine of triazole labeled groups and its byproduct was detected In the liver of phenyl labeled groups only. Other urinary metabolites were not characterized.Page 50 of 69

Table A.1.3. Subchronic, Chronic and Other Toxicity Profile of Difenoconazole Metabolites Guideline No. Study Type MRID No. (year)/ Classification /Doses Results 870.5100 In vitro Bacterial

Gene Mutation (Salmonella typhimurium/ E. coli) / mammalian activation gene mutation ass ay 46950314 (1991)

Unacceptable/ guideline 0, 31.3, 62.5, 125, 250, 500 or 1000 μg/plate in strains TA100 and TA 1537 ( - S9) 0, 31.3, 62.5, 125, 250, 500 or 1000 μg/plate in all strains (+S9) 0, 62.5, 125, 250, 500, 1000 or 2000 μg/plate in strains TA1535, W P2 uvrA and TA98 ( - S9) 0, 62.5, 125, 250, 500, 1000 or 2000 μg/plate in strains W P2 uvrA (+S9) The number of revertants per plate w as not increased over the concurrent solvent control value at any test material concentration, with or without S9 - mix, in any tester strain. The solvent and positive controls induced the appropriate responses in the corresponding strains. There was no evidence of induced mutant colonies over background. Tested: CGA - 189138 (m etabolite of difenoconazole)

870.5100 In vitro Bacter ial

Gene Mutation (Salmonella typhimurium/ E. coli) / mammalian activation gene mutation assay 46950315 (1991)

Unacceptable/ guideline 0, 156, 313, 625, 1250, 2500 or 5000 μg/plate (  S9) The number of revertants per plate w as not increased over the concurre nt solvent control value at any test material concentration, with or without S9 - mix, in any tester strain. The solvent and positive controls induced the appropriate responses in the corresponding strains. There was no evidence of induced mutant colonies ov er background. Tested: CGA205374 (metabolite of difenoconazole) 870.5100 In vitro Bacterial

Gene Mutation (Salmonella typhimurium/ E. coli) / mammalian activation gene mutation assay 46950317 (1991)

Unacceptable/ guideline 0, 2.50, 5.00, 10.0, 20.0, 40.0 or 80.0 μg/plate in all strains ( - S9) 0, 5.00, 10.0, 20.0, 40.0, 80.0 or 160 μg/plate in strains TA100 and TA 1535 (+S9) 0, 10.0, 20.0, 40.0, 80.0, 160 or 320 μg/plate in strains WP2 uvrA and TA 1537 ( - S9) 0, 2.50, 5.00, 10.0, 20.0, 40.0, or 80.0 μg/plate in strain TA98 (+S9) The number of revertants per plate w as not increased over the concurrent solvent control value at any test material concentration, with or without S9 - mix, in any tester strain. The solvent and positive controls induced the appropriate re sponses in the corresponding strains. There was no evidence of induced m utant colonies over background. Tested: CGA205375 (metabolite of difenoconazole)Page 51 of 69

EXECUTIVE SUMMARIES OF SOME STUDIES: STUDY TYPE : 28 - Day Dermal Toxicity – Rat

( OPPTS 870.3200 [§ 82 - 2] (rodent); OECD 410). CITATION : Gerspach, R. Difenoconazole: 28 - Day Repeated Dose Dermal Toxicity Study in Rats. Novartis Crop protection AG Toxicology (Switzerland). Novartis Report Number: 993072; Sy

ngenta Report Number: T002728 - 06. July 11, 2000, MRID 46950310 and MRID 46950311. Unpublished. EXECUTIVE SUMMARY : Ina 28 - day dermal toxicity

study (MRID 46950310) CGA 169374 Technical (91.8% a.i., Batch No. P807002 ) was applied to the shaved skin of ten male and ten female rats at dose levels of 0, 10 , 100 and 1000 mg/kg bw/day . There were no treatment - related effects on body weight or food consumption. Non clinical signs of toxicity were noted including specific indicators of neurotoxicity . The dose level of 1000 mg/kg bw/day

caused hy

perkeratosis at the skin application site. A high incidence of follicular cell hy

pertrophy of the thy

roid was observed in males and females of control and all treatment groups and variations with dose are not considered treatment - related . Minimal inconsequential changes w ere noted on clinical chemistry parameters in high dose males that were not relevant toxicologically . T he incidence and severity was increased in animals in the highest dose group. There was an increase in the absolute (12%) and relative (16%) weight of th e liver in males in the high dose group accompanied by

an increased incidence of slight hepatocellular hy pertrophy (7/10) compared to controls (2/10). Females in the high dose group also had an increase in the relative weight of the liver (10%) with an in creased incidence of slight hepatocellular hy pertrophy (7/10) compared to controls (1/10). These effects are consistent with adaptive responses of the liver. A systemic LOAEL for male and female rats was not established. The NOAEL for male and female rats is 1000 mg/kg bw/day. A dermal irritation LOAEL for male and female rats is 1000 mg/kg bw/day based on hyperkeratosis at the skin application site. The dermal NOAEL for male and female rats is 100 mg/kg bw/day . This 28 - day

dermal toxicity

study in the F ischer 344 rat is A cceptable/Guideline and satisfies the guideline requirement for a 28 - day dermal toxicity

study (OPPTS 870.3200; OECD 410) in the rat. STUDY TYPE : A cute Neurotoxicity - Rats OPPTS 870.6200a [ § 81 - 8]; OECD 424. CITATION : Pinto, P.J. (2006 ) Difenoconazole Technical (CGA169374): Acute

Neurotoxicity

Study in Rats . Central Toxicology L aboratory

(Cheshire,Page 52 of 69 UK). Laboratory

report number AR7517 - REG - R1 , July 28, 2006. MRID 46950327. Unpublished. Pinto, P.J. (2006) Difenoconazole Technical (CGA1 69374): Preliminary Acute Neurotoxicity

Study in Rats . Central Toxicology L aboratory

(Cheshire, UK). Laboratory

report number AR7518 - REG , June 16, 2006. MRID 46950325. Unpublished. EXECUTIVE SUMMARY : Inan acute neurotoxicity study (MRID 46950327), grou ps of fasted Alpk:AP f

SD Wistar - derived rats (10/sex/dose) , at least 42 day s old , were given a single oral dose of difenoconazole technical (CGA169374) (94.3% w/w, batch/lot # WM806228 ) in 1% w/v aqueous carboxy methylcellulose (CMC) at doses of 0, 25, 200, or 2000 mg/kg bw and observed for 14 day s. Dose levels selected for this study were based on the results of a preliminary acute neurotoxicity

study (MRID 46950325). Neurobehavioral assessment (functional observational battery and motor activity

testing) was performed on 10 animals/sex/group on day s - 7, 1, 8, and 15. Body weight and food consumption were measured weekly throughout the study . At study termination, 5 animals/sex/group were euthanized and perfused in situ for neuropathological examination; brain weight was recorded from these animals. Of the perfused animals, 5 animals/sex from the control and high dose groups were subjected to histopathological evaluation of brain and peripheral nervous system tissues. There were no unscheduled deaths at any dose level. Weight change on the day of dosing by the control, low - , mid - , and high - dose groups was - 2.1, - 1.0, - 7.8, and - 18.3 g, respectively , for males and 0.0, 2.1, - 3.8, and - 13.0 g, respectively , for females. Body weight for females had recover ed to control levels by day 8. Food consumption for males given 2000 mg/kg was approximately 20% less than control during week 1 only (p<0.01). Food consumption for these animals recovered to control levels during week 2. There were no differences from control for females at any dose level or for males at the lower dose levels. These effects on body weight and food consumption were not toxicologically significant. At 2000 mg/kg, a number of adverse clinical signs were observed on day 1 (at the time of peak effect), including: upward curvature of the spine (8 males, 9 females); tip - toe gait (3, 8); decreased activity

(6, 7); piloerection (3, 5); sides pinched in (3, 7); and subdued (1, 0). Females were affected more than males. All treatment - related cl inical signs observed on day 1 showed complete recovery by day 5 (males) or day

7 (females). Significant decreases in fore - limb grip strength were seen in mid - ( ↓ 23%) and high - dose ( ↓ 26%) males on day

1. Females dosed with 2000 mg/kg had lower motor activities on day 1 (37%), at the time of peak effect, and on day 8 (31%). Males dosed with 200 or 2000 mg/kg had higher motor activities than the controls on day 1, 50% and 55%, respectively , at the time of peak effect. There were no effects on brain weight at any dose level . NeuropathologicalPage 53 of 69

examination of the central and peripheral nervous system showed no effects of treatment at doses of 2000 mg/kg in both sexe s . The LOAEL for acute neurotoxicity of difenoconazole technical (CGA169374) in male rats is 200 mg/kg bw based on reduced fore - limb grip strength in males on day 1 and increased motor activity on Day 1 . The NOAEL is 25 mg/kg bw. The LOAEL for acute ne urotoxicity of difenoconazole technical (CGA169374) in female rats is 2000 mg/kg bw based on decreased body weight, the following clinical signs: upward curvature of the spine, tip - toe gait, decreased activity, piloerection and sides pinched in and decrea sed motor activity . The NOAEL is 200 mg/kg bw. This acute neurotoxicity

study is classified as Acceptable/Guideline and satisfies the guideline requirement for an acute neurotoxicity study in rats (870.6200; OECD 424). Positive control data have been submitted for review and were considered acceptable. STUDY TYPE : Subchronic Neurotoxicity, OPPTS 870.6200b [ § 82 - 7] feeding - rat;

(OECD 424). CITATION : Pinto, P J. (2006). Difenoconazole technical (CGA 169374) subchronic

neurotoxicity study

in rats, final report. Central Toxicology L aboratory , Alderley Park, Macclesfield, Cheshire, UK SK 10 4TJ. Report number PR1330 - REG - R1. July

28, 2006. MRID 46950329. Unpublished. Pinto, P.J. (2006). Difenoconazole technical (CGA 169374) 28 - day dietary rangefinding study

in rats, final report. Central Toxicology L aboratory , Alderley Park, Macclesfield, Cheshire, UK SK 10 4TJ. Report number KR1606 - REG. June 13, 2006. MRID 46950326. Unpublished. Alexander, O. (2006) Difenoconazole techni cal (CGA 169374) subchronic neurotoxicity

study in rats

– study

profile. Sy

ngenta Crop Protection, Inc., 410 Swing Road, P.O. Box 18300, Greensboro, NC 27419 - 8300. Report number PR1330 - REG - R1. September 19, 2006. MRID 46950330. Unpublished. EXECUTIVE SUMMARY : Ina subchronic neurotoxicity study (MRID 46950329) difenoconazole technical (94.5% w/w, batch no. WM806228) was administered to groups of 12 male and 12 female Alpk:AP f SD (Wistar - derived) rats at concentrations of 0, 40, 250, or 1500 ppm in the diet for 90 day s. Respective dose levels corresponded to 0, 2.8, 17.3 or 107.0 mg/kg bw/day for males and 0, 3.2, 19.5, or 120.2 mg/kg bw/day for females. Neurobehavioral assessment (functional observational battery and motor activity testing) was perfo rmed in 12 animals/sex/group pretest and during weeks 2, 5, 9, and 14. Cholinesterase activity was not determined. At study termination, 5 animals/sex/group were euthanized and perfused in situ for neuropathological examination. Of the perfused animals, 5/sex from the control group and 5/sex from thePage 54 of 69

1500 ppm group were subjected to histopathological evaluation of brain and peripheral nervous sy stem tissues. Treatment with difenoconazole at concentrations up to 1500 ppm in the diet had no effect on mortality

or clinical signs. Relative to respective control weight, final body weight of males and females in the 1500 ppm group was reduced by 9% and 7%. Body

weight gain was reduced by

22% in males and 23% in females. Food consumption was reduced in this group (statistically

significant only

in females [7%]), and food efficiency was significantly

reduced in males by

21% (p ≤0.05) and in females by 21% (ns). L ower dose groups were unaffected. Absolute liver weight in males and females in the 1500 ppm group was increased over respective co ntrol weight by 38% and 45%. L iver was not weighed in lower dose groups. The increase in liver weight was considered a normal response to chemical treatment. During weeks 2, 9 and 14, hind - limb grip strength in males in the 1500 ppm group was reduced by 18 to 27% relative to the control values. At week 14, hind - limb grip strength in males in the 250 ppm group was significantly (p ≤0.05) reduced by

20% relative to the control values. FOB observations in females were unaffected by treatment. Motor activi ty was unaffected in both sexes at all observation times. Brain weight was unaffected by

treatment and there were no treatment - related neuropathological lesions. The LOAEL in male rats is 250 ppm in the diet (17.3 mg/kg bw/day), based on decreased hind limb strength. The NOAEL is 40 ppm (2.8 mg/kg bw/day). The LOAEL in female rats is 1500 ppm in the diet (120.2 mg/kg bw/day), based on decreased body weight, body weight gain and food efficiency. The NOAEL is 250 ppm (19.5 mg/kg bw/day). The study is classified as A cceptable/Guideline and does satisfies the guideline requirement for a subchronic neurotoxicity study in rats (870.6200b). Positive control data have been submitted for review and were considered acceptable. STUDY TYPE : Rodent In Viv o Dermal Penetration Study

– Rat

OPPTS 870.7600 [ § 85 - 2]; OECD none. CITATION : Hassler, S. (2003) Difenoconazole 250 EC (A7402G): Dermal absorption

of [Triazole - U 14 C] CGA 169374 formulated as Score ® 250 EC (A 7402G) in the rat ( in vivo ). Sy ngenta Crop Pro tection AG, Health Assessment/Animal Metabolism CH - 4002 Basel, Switzerland. Sy ngenta Number T002729 - 06, May 6, 2003. MRID 46950333. Unpublished. EXECUTIVE SUMMARY : Ina dermal penetration study (MRID 46950333), [Triazole

–

U 14 C] CGA 169374 (radiolabled: b atch # 50.2 - 1 and 50.2 - 2 contained 98 and 99.3% a.i., respectively ; nonradiolabeled: batch # AMS 255/3 contained 99.3% a.i.) formulated as Score ® 250 EC (A - 7402G) was administered to 16 male HanBrl: WI STPage 55 of 69

(SPF) rats/dose to a skin area of 10 cm 2 at nominal dose levels of 0, 0.005, 0.0125, and 2.5 mg/cm 2 skin. The 2.5 mg/cm 2 dose was repeated because of a high variability in the results of the washing procedure. Measured dose levels were 0.005, 0.0130, 2.4, and 2.6 mg/cm 2 for the low, mid, and high dose and high dose repeat groups, respectively . Exposure duration was 6 hours and animals were monitored for 6, 24, 48, or 72 hours . The remaining discussion of dermal penetration at the high dose will include only the “high - dose repeat” data (i.e., the results of the first high - dose exposure will not be discussed). Recovery

of the applied dose was acceptable with group means ranging from 95.44 to 103.67 %. Results were not adjusted for incomplete recovery of the applied dose. The majority

of the applied dose was recovered in the skin wash, accounting for 49 - 69%, 73 - 78%, and 76 - 86% of the low, mid, and high dose, respectively . The amount of the applied dose retained at the application site was 8 - 12%, 3 - 5%, and 2 - 5% of the low, mid, and high dose, respectively . At the low and mid dose, the major part of the radioactivity remaining in the skin was associated with the stratum corneum (7 - 11% and 2 - 5%, respectively

), while only

1 - 2% of the high dose was recovered in the upper skin layer. Dermal absorption ( sum of blood, carcass, urine, feces, skin test site, gastrointestinal tract, untreated skin, and cagewash) accounted for 15 - 38%, 7 - 15%, and 3 - 11% of the low, mid, and high doses, respectively . Of the test substance sy stemically absorbed, excretion into the feces was generally the primary

route of elimination, accounting for up to 18%, 8%, and 2% of the low, mid, and high doses, respectively . Of the radioactivity remaining in the animal 72 hours after application, the gastrointestinal tract contained 3.0%, 1.4%, and 0.3% of the low, mid, and high doses, respectively , and the carcass contained 1.5%, 0.7%, and 1.1%, respectively . Blood concentrations during and after the exposure period were at or below the limits of determination. Based on the limited blood concentration data available, maximum blood concentrations were measured between 6 - 8 hours after dose application. Based on the amount of radioactivity entering the sy stemic circulation within 6 hours of exposure, the calculated penetration rates at the low, mid, and high doses were 0.013, 0.162, and 30.4 μ g cm - 2 h - 1 , respectively . The penetration rates increased somewhat proportionally

with the increase of the test substance concentration at the three dose levels (1:26:5100 for the concentration ratio of th e dose levels versus 1:12:2300 for the ratio of the penetration values). This study

in the rat is unacceptable/guideline and does not satisfy the guideline requirement for a dermal penetration study (870.7600) in rats. Major deficiencies include uncertai nty

in the ability

of the laboratory

to perform the experiment, and only one exposure duration was tested (6 hours), despite minimum Guideline recommendations for durations of 1, 10, and 24 hours. See “Study Deficiencies” for listing of numerous minor def iciencies. STUDY TYPE : In Vitro Dermal Penetration Study – Rat and Human

OPPTS 870.7600 [ § 85 - 2]; OECD none. CITATION : Hassler, S. (2003) Difenoconazole 250 EC (A7402G): The percutaneousPage 56 of 69 penetration of [Triazole - U 14 C] CGA 169374 formulated as Score ® 250 EC (A - 7402G) through rat and human split - thickness skin membranes ( in vitro ). Sy ngenta Crop Protection AG, Health Assessment/Animal Metabolism CH - 402 Basel, Switzerland. Sy ngenta Number T002730 - 06, April 9, 2003. MRID 46950332. Unpublished. EXECUTIVE SUM MARY : Inan in vitro percutaneous penetration study (MRID 46950332), [Triazole

–

U 14 C] CGA 169374 (98% a.i., batch number 50.2 - 1) mixed with nonradiolabeled CGA 169374 (batch number AMS 255/3 containing 99.3% a.i.) formulated as SCORE 250 ® (A - 7402) was app lied to skin membranes prepared from rat [male HanBrl: WI ST (SPF)] and human (cadaver) abdominal skin. Percutaneous absorption at low, mid, and high doses of 0.5, 12.5, or 2500 μ g/ cm 2 (actual applied doses of 0.5, 12, or 2345 μ g/ cm 2 ) was assessed over 24 h ours. Results clearly

indicate that transfer of [Triazole

– U 14 C] CGA 169374 across skin membrane was notably

greater for the rat skin membrane than for human skin membrane as shown by

flux values that were 10 - , 12 - , and 32 - fold greater for the low, mid, and high concentrations, respectively . A concentration - dependent absorption was also indicated by greater flux values with increasing concentration: flux values at the low, mid, and high doses for the rat skin membranes were 0.020, 0.455, and 26.2 ug/cm 2 , respectively , and for human skin membranes were 0.002, 0.037, and 0.822 ug/cm 2 , respectively . The increasing flux values resulted in greater absolute amounts of test article being transferred across the skin membranes with increasing concentration: valu es at the low, mid, and high doses for the rat skin membranes were 0.35, 7.7, and 539.2 ug/cm 2 , respectively , and for human skin membranes were 0.04, 0.84, and 15.6 ug/cm 2 , respectively . However, the percutaneous absorption was decreased, indicating satur ated kinetics (absorption values at the low, mid, and high doses expressed as percent of applied dose for the rat skin membranes were 71%, 64%, and 23% , respectively , and for human skin membranes were 8%, 7%, and 0.7%, respectively ). This in vitro percutaneous absorption study in the rat is acceptable/nonguideline , but does not satisfy the guideline requirement for a dermal penetration study (870.7600) in rats. The study

is a specialty

study and was designed to provide only supplemental information to th e OPPTS 870.7600 requirement. Results of this study provide information on the differences in dermal absorption between rat and human skin membranes. STUDY TYPE : In vitro Mammalian Cytogenetics (chromosomal aberrations) a ssay

in Chinese hamster CHO cel ls; OPPTS 870.5375 [§84 - 2]; OECD 473 CITATION : Ll oyd, M. (2001) Difenoconazole Technical: Induction of chromosome

aberrations in cultured Chinese hamster ovary (CHO)cells. Covance Laboratories Ltd., Otley

Road, Harrogate, North Yorkshire HG3 1PY,Page 57 of 69 England . L aboratory

Project ID: Covance Number 252/293, Sy ngenta Number T002874 - 06, December 11, 2001. MRID 46950319. Unpublished EXECUTIVE SUMMARY : Ina mammalian cell cy togenetics assay

( Chromosomal aberrations) (MRID 46950319), Chinese hamster CHO cells in culture were exposed to CGA 169374 Technical (94.3% w/w, L ot No. WM806228) in DMSO for three hours at concentrations of 0, 21.99, 27.49, or 34.36 μg/mL without metabolic activation (S9 - mix) and at concentrations of 0, 34.36, 53.69 or 67.11 μg/mL with S9 - mi x. Cells were harvested 17 hours following the end of exposure. Cells were exposed in a second confirmatory

study for three hours at concentrations of 0, 21.99, 27.49 or 34.36 μg/mL without S9 - mix and for three hours at concentrations of 0, 34.36, 53.69, 67.11 or 83.89 μg/mLwith S9 - mix. Cells were harvested 17 hours following exposure. Cells were evaluated for the presence of structural chromosomal aberrations and for numerical aberrations (poly

ploidy , endoreduplication and hy perploidy ). The S9 - fracti on was obtained from Aroclor 1254 induced male Sprague - Dawley rat liver. CGA 169374 Technical was tested up to cy totoxic concentrations as evidenced by a dose related reduction in mitotic activity seen with and without S9 - mix. There was a statistically significant increase in the percentage of cells with structural chromosomal aberrations at a CGA 169374 Technical concentration of 34.36 μg/mL without S9 - mix in the first study . The slides were rescored to determine if aberrations at the fragile X site we re present. Aberrations at the fragile X site are not likely relevant to clastogenicity . Aberrations at the fragile X site were not found but the values obtained on rescoring were within the historical solvent control range. There was no clear reason gi ven why the percent of aberrant cells was lower when the slides were rescored. Possibly the distribution of cells on the slides was uneven. The increase at this dose without S9 - mix was not seen in the confirmatory assay and thus the increase was not consid ered biologically

significant. A statistically significant increase in the percent of aberrant cells was seen in the first study at 67.11 μg/mLwith S9 - mix. The statistical significance remained upon rescoring and all values exceeded the historical solve nt control range. No statistically

significant increase was seen at this or a higher concentration in the confirmatory

study with S9 - mix. The failure to see a significant increase in the percent of aberrant cells in the confirmatory study makes the resul ts equivocal. The solvent and positive controls (4 - Nitroquinoline 1 - oxide without S9 - mix and cyclophosphamide with S9 - mix) induced the appropriate responses. There was evidence of a weak induction of structural chromosomal aberrations over background in the presence of S9 - mix. This study

is classified as Acceptable/Guideline and satisfies the guideline requirement for OPPTS 870.5375; OECD 473 for in vitro cy togenetic mutagenicity

data. STUDY TYPE : In vitro Mammalian Cytogenetics (chromosomal aberrations ) a ssay

in Chinese hamster CHO cells; OPPTS 870.5375 [§84 - 2]; OECD 473 CITATION : Ogorek, B. (2001) Difenoconazole Technical: Cy togenetic test on ChinesePage 58 of 69 hamster cells in vitro . Sy

ngenta Crop Protection AG, Health Assessment 2 Stein/Genetic Toxicology , CH - 4332 Stein, Switzerland. L aboratory Project ID: Sy

ngenta AG Test Number 20013013, Sy ngenta Number T002875 - 06, December 3, 2001. MRID 46950321. Unpublished EXECUTIVE SUMMARY : Ina mammalian cell cy togenetics assay

( Chromosomal aberrations) (MRID 46950321) , Chinese hamster CHO cells in culture were exposed to CGA 169374 Technical (94.3% w/w, L ot No. WM806228) in DMSO for three hours at concentrations of 0, 26.3, 39.5 or 59.3 μg/mL without metabolic activation (S9 - mix) and at concentrations of 0, 11.7 or 17. 6 μg/mLwith S9 - mix. Cells were harvested 18 hours following the end of exposure. Cells were exposed in a second confirmatory study for 21 hours at concentrations of 0, 2.3, 5.2 or 11.7 μg/mL without S9 - mix and for three hours at concentrations of 0, 7.8 , 11.7 or 17.6 μg/mLwith S9 - mix. Cells were harvested immediately

following the 21 - hour exposure and 18 hours after the three - hour exposure. Cells were evaluated for the presence of structural chromosomal aberrations and for poly ploidy . The S9 - fraction was obtained from Aroclor 1254 induced male HanIbm:WI ST(SPF) rat liver. CGA 169374 Technical was tested up to cy totoxic concentrations as evidenced by a dose related reduction in mitotic activity seen with and without S9 - mix. There was a statistically significant increase in the percentage of CHO cells with structural chromosomal aberrations at a CGA 169374 Technical concentration of 59.3 μg/mL without S9 - mix in the original study when aberrations at the fragile X site were included but not when they

we re excluded. Aberrations at the fragile X site are not likely relevant to clastogenicity . No statistically significant increase in the percent of aberrant cells was seen in the original study

with S9 - mix. An increase in the percent of aberrant cells was seen in the confirmatory

study at 17.6 μg/mLwith S9 - mix and the increase was statistically

significant (p ≤0.001) when aberrations at the fragile X site were excluded. The value of 6.5% aberrant cells exceeded the value of >6% set as a criterion for a po sitive effect in the testing laboratory . The failure to see a significant increase in the percent of aberrant cells in the original study makes the results equivocal. No statistically significant increase in the percentage of aberrant cells was seen at a ny of the three test material concentrations without S9 - mix in the confirmatory study . The solvent and positive controls (Mitomycin C without S9 - mix and Cyclophosphamide with S9 - mix) induced the appropriate responses. There was evidence of a weak inducti on of structural chromosomal aberrations over background. This study

is classified as Acceptable/Guideline and satisfies the guideline requirement for OPPTS 870.5375; OECD 473 for in vitro cy togenetic mutagenicity

data. STUDY TYPE : In vitro Mammalian C ytogenetics (chromosomal aberrations) a ssay

in human lymphocytes ; OPPTS 870.5375 [§84 - 2]; OECD 473 CITATION : Fox, V. (2001) Difenoconazole Technical: In vitro cy togenetic assay

in human ly mphocy tes. Central Toxicology

L aboratory , AlderleyPage 59 of 69 Park/Macclesfiel d, Cheshire, UK SK10 4TJ. L aboratory Project ID: CTL Number SV1090, Sy

ngenta Number T002876 - 06, August 29, 2001. MRID 46950323. Unpublished EXECUTIVE SUMMARY : Ina mammalian cell cy togenetics assay

( Chromosomal aberrations) (MRID 46950323), human ly mphoc yt es in culture were exposed to CGA 169374 Technical (94.3% w/w, L ot No. WM806228) in DMSO for three hours at concentrations of 0, 5, 30 or 75 μg/mL without metabolic activation (S9 - mix) and at concentrations of 0, 5, 30 or 62 μg/mL with S9 - mix. Cells wer e harvested 17 hours following the end of exposure. Cells were exposed in a second experiment for 20 hours at concentrations of 0, 1, 5 or 10 μg/mL without S9 - mix and for three hours at concentrations of 0, 5, 30 or 50 μg/mL with S9 - mix. Cells were harve sted immediately following the 20 - hour exposure and 17 hours after the three - hour exposure. Cells were evaluated for the presence of structural chromosomal aberrations. The S9 - fraction was obtained from Phenobarbital + β - naphthoflavone induced male Sprague - Dawley rat liver. CGA 169374 Technical was tested up to cy totoxic concentrations as evidenced by a dose related reduction in mitotic activity seen with and without S9 - mix. No statistically significant increases in the percentage of cells with structural aberrations, excluding gaps, over the solvent control values were seen at any test material concentration with or without S9 - mix in the first experiment or without S9 - mix in the second experiment. A statistically

significant increase over the solvent control value was seen at 5μg/mL with S9 - mix in the second experiment; however, the increase was not considered biologically significant because the value (4.00%) was within the historical solvent control range, the values at the two higher concentrations were not significantly increased and no increase was seen in the first experiment. The solvent and positive controls (Mitomycin C without S9 - mix and Cyclophosphamide with S9 - mix) induced the appropriate responses. There was no evidence of structural chrom osomal aberrations induced over background. This study

is classified as Acceptable/Guideline and satisfies the guideline requirement for OPPTS 870.5375; OECD 473 for in vitro cy togenetic mutagenicity

data. DIFENOCONAZOLE METABOLITES: STUDY TYPE : In vitro Bacterial Gene Mutation (Bacterial system, Salmonella

typhimurium and Escherichia coli )/ mammalian activation gene mutation assay ; OPPTS 870.5100 [§84 - 2]; OECD 471 (formerly OECD 471 & 472). CITATION : Nakajima, M. (1991) CGA189138 (metabolite of difenoc onazole): reverse

mutation assay

of CGA189138. Biosafety Research Center; Foods, Drugs and Pesticides (An - Pyo Center); 582 - 2, Arahama Shioshinden; Fukude Cho Iwata - Gun.; Shizuoka 437 - 12; Japan. L aboratory Project ID: BRC Number 1809, October 21, 1991. MRID 46950314. Unpublished.Page 60 of 69

EXECUTIVE SUMMARY : Ina reverse gene mutation assay in bacteria (MRID 46950314), strains TA98, TA100, TA1535 and TA1537 of S. typhimurium and strain WP2 uvrA of E. coli were exposed to CGA - 189138, a metabolite of difenoconazole, (97.8% a.i., lot number 910806) dissolved in DMSO in two independent assays using a 20 - minute preincubation procedure and duplicate plating. I n the first mutagenicity

assay , which was alternatively

called the pilot assay

and the dose - finding assay , concentrations of 0, 51.2, 128, 320, 800, 2000 or 5000 μg/plate were tested with and without S9 - mix. In the second assay , which was called the main assay , concentrations of 0, 31.3, 62.5, 125, 250, 500 or 1000 μg/plate were tested in the absence of S9 - mix in str ains TA100 and TA1537 and in the presence of S9 - mix in all Salmonella strains; concentrations of 0, 62.5, 125, 250, 500, 1000 or 2000 μg/plate were tested in the absence of S9 - mix in strains TA1535, WP2 uvrA and TA98 and in the presence of S9 - mix in strain W P2 uvrA . The S9 fraction was obtained from phenobarbital and 5,6 - benzoflavone - induced male Sprague Dawley rat liver. CGA - 189138 was tested at concentrations up to the limit concentration for the assay in the pilot assay , and many of the higher concentrations tested in both assay s showed cy totoxicity and sometimes also insolubility . Inthe absence of S9 - mix in the pilot assay , the test material was cy

totoxic, as judged by

stereomicroscopic examination of the bacterial lawns, at concentrations of 800 μg/pl ate and higher in strains TA100 and TA1537 and at concentrations of 2,000 μg/plate and higher in strains TA1535, WP2 uvrA and TA98. In the presence of S9 - mix in the pilot assay , the test material was cy totoxic at concentrations of 800 μg/plate and higher i n all four Salmonella strains and at concentrations of 2,000 μg/plate and higher in strain WP2 uvrA . Inthe absence of S9 - mix in the main assay , the test material was cy totoxic at concentrations of 500 μg/plate and higher in strain TA100, at concentrations of 1,000 μg/plate and higher in strains TA1535 and TA98, and at the maximum concentrations tested in strains WP2 uvrA and TA1537. Inthe presence of S9 - mix in the main assay , the test material was cy totoxic at concentrations of 500 μg/plate and higher in strains TA100, TA1535 and TA1537 and at the maximum concentrations tested in strains WP2 uvrA and TA98. At cy totoxic concentrations there was often also a marked decrease in the number of revertant colonies found. In the pilot assay , precipitation of the white powdery test material was observed on the surface of the agar plates at the time of colony counting at concentrations of 5,000 μg/plate in the absence of S9 - mix and at concentrations of 2,000 μg/plate and above in the presence of S9 - mix. In the main a ssay , such precipitation was observed only in the presence of S9 - mix and at the highest concentration tested in strain WP2 uvrA . The number of revertants per plate was not increased over the concurrent solvent control value at any test material concentrati on, with or without S9 - mix, in any tester strain. The solvent and positive controls induced the appropriate responses in the corresponding strains. There was no evidence of induced mutant colonies over background. This study

is classified as Unacceptable/ Guideline and does not satisfies the requirements for Test Guideline OPPTS 870.5100; OECD 471 for in vitro mutagenicity (bacterial reverse gene mutation) data. Five strains of S. typhimurium were not used in the assay . The study

can not be upgraded.Page 61 of 69

STU DY TYPE : In vitro Bacterial Gene Mutation (Bacterial system, Salmonella

typhimurium and Escherichia coli )/ mammalian activation gene mutation assay ; OPPTS 870.5100 [§84 - 2]; OECD 471 (formerly OECD 471 & 472). CITATION : Nakajima, M. (1991) CGA205374 (metab olite of difenoconazole): reverse

mutation assay

of CGA205374. Biosafety Research Center; Foods, Drugs and Pesticides (An - Pyo Center); 582 - 2, Arahama Shioshinden; Fukude Cho Iwata - Gun.; Shizuoka 437 - 12; Japan. L aboratory Project ID: BRC Number 1746, August 14, 1991. MRID 46950315. Unpublished. EXECUTIVE SUMMARY : Ina reverse gene mutation assay in bacteria (MRID 46950315), strains TA98, TA100, TA1535 and TA1537 of S. typhimurium and strain WP2 uvrA of E. coli were exposed to CGA - 205374, a metabolite of difenoconazole, (99.3% a.i., lot number 9106054) dissolved in DMSO in two independent assays using a 20 - minute preincubation procedure and duplicate plating. I n the first mutagenicity

assay , which was alternatively

called the pilot assay

and the dose - findi ng assay , concentrations of 0, 51.2, 128, 320, 800, 2000 or 5000 μg/plate were tested with and without S9 - mix. In the second assay , which was called the main assay , concentrations of 0, 156, 313, 625, 1250, 2500 or 5000 μg/plate were tested with and without S9 - mix. The S9 fraction was obtained from phenobarbital and 5,6 - benzoflavone - induced male Sprague - Dawley rat liver. CGA - 205374 was tested at concentrations up to the limit concentration for the assay , but the effective concentrations tested were limited by insolubility . Evidence of cy totoxicity , which was collected by stereomicroscopic examination of the bacterial lawns, was seen only in strain TA1537 at the maximum concentration tested, and then only in the main assay in the presence of S9 - mix. The test material was quite insoluble, with cloudiness of the preincubation mixture being observed even at 128 μg/plate. The white powdery precipitate of the test material was observed on the surface of the agar plates at the time of colony counting at concentrati ons of 320 μg/plate and higher in the pilot assay in the absence of S9 - mix and at concentrations of 800 μg/plate and higher in the presence of S9 - mix. In the main assay , this precipitate was noted at concentrations of 313 μg/plate and higher both in the p resence and absence of S9 - mix. This precipitate became heavy enough to make it difficult to observe the bacterial lawn at concentrations of 1250 μg/plate or higher in the absence of S9 - mix and at the concentration of 5000 μg/plate in the presence of S9 - mix . The number of revertants per plate was not increased over the concurrent solvent control value at any test material concentration, with or without S9 - mix, in any tester strain. The solvent and positive controls induced the appropriate responses in the co rresponding strains. There was no evidence of induced mutant colonies over background. This study

is classified as Unacceptable/Guideline and does not satisfies the requirements for Test Guideline OPPTS 870.5100; OECD 471 for in vitro mutagenicityPage 62 of 69

(bacterial reverse gene mutation) data. Five strains of S. typhimurium were not used in the assay . The study

can not be upgraded. STUDY TYPE : In vitro Bacterial Gene Mutation (Bacterial system, Salmonella

typhimurium and Escherichia coli )/ mammalian activation gene mutation assay ; OPPTS 870.5100 [§84 - 2]; OECD 471 (formerly OECD 471 & 472). CITATION : Nakajima, M. (1991) CGA205375 (metabolite of difenoconazole): reverse

mutation assay

of CGA205375. Biosafety Research Center; Foods, Drugs and Pesticides (An - Pyo C enter); 582 - 2, Arahama Shioshinden; Fukude Cho Iwata - Gun.; Shizuoka 437 - 12; Japan. L aboratory Project ID: BRC Number 1747, August 14, 1991. MRID 46950317. Unpublished. EXECUTIVE SUMMARY : Ina reverse gene mutation assay in bacteria (MRID 46950317), str ains TA98, TA100, TA1535 and TA1537 of S. typhimurium and strain WP2 uvrA of E. coli were exposed to CGA - 205375, a metabolite of difenoconazole, (99.8% a.i., lot number 9106055) dissolved in DMSO in two independent assays using a 20 - minute preincubation pr ocedure and duplicate plating. In the first mutagenicity assay , which was alternatively

called the pilot assay

and the dose - finding assay , concentrations of 0, 51.2, 128, 320, 800, 2000 or 5000 μg/plate were tested with and without S9 - mix. In the second as say , which was called the main assay , concentrations of 0, 2.50, 5.00, 10.0, 20.0, 40.0 or 80.0 μg/plate were tested in the absence of S9 - mix in all strains; concentrations of 0, 5.00, 10.0, 20.0, 40.0, 80.0 or 160 μg/plate were tested in the presence of S 9 - mix in strains TA100 and TA1535; concentrations of 0, 10.0, 20.0, 40.0, 80.0, 160 or 320 μg/plate were tested in the presence of S9 - mix in strains WP2 uvrA and TA1537 ; and concentrations of 0, 2.50, 5.00, 10.0, 20.0, 40.0, or 80.0 μg/plate were tested in the presence of S9 - mix in strain TA98. The S9 fraction was obtained from phenobarbital and 5,6 - benzoflavone - induced male Sprague - Dawley rat liver. CGA - 205375 was tested at concentrations up to the limit concentration for the assay in the pilot assay . Mos t of the concentrations in that assay showed cy

totoxicity and some of the higher ones also showed insolubility . Some of the higher concentrations in the main assay , which used much lower concentrations, also showed cy totoxicity . Inthe absence of S9 - mix in the pilot assay , the test material was cy totoxic, as judged by

stereomicroscopic examination of the bacterial lawns, at all concentrations in strains TA100 and TA1537 and at concentrations of 128 μg/plate and higher in strains TA1535, WP2 uvrA and TA98. In the presence of S9 - mix in the pilot assay , the test material was cy totoxic at all tested concentrations in strain TA98, at concentrations of 128 μg/plate and higher in strains TA100 and TA1535, and at concentrations of 320 μg/plate and higher in strains WP2 uvrA and TA1537. Inthe absence of S9 - mix in the main assay , the test material was cy totoxic at concentrations of 40.0 μg/plate and higher in strain TA100 and at the highest tested concentration in the other strains. In the presence of S9 - mix in the ma in assay , the test material was cy

totoxic at concentrations of 40.0 μg/plate and higher in strain TA98, at concentrations of 80.0 μg/plate and higher in strain TA100, at concentrations of 160Page 63 of 69

μg/plate and higher in strain TA1537 and at the maximum concentrations tested in strains TA1535 and WP2 uvrA . At cy totoxic concentrations there was often also a marked decrease in the number of revertant colonies found. Because cy totoxicity was excessive at most concentrations, the pilot assay provided only

slight usef

ul information on mutagenesis in most strains. In the pilot assay , the needle cry stalline precipitate of the test material was observed on the surface of the agar plates at the time of colony counting at concentrations of 800 μg/plate and above in the abse nce of S9 - mix and at concentrations of 2,000 μg/plate and above in the presence of S9 - mix. No precipitation was observed at any of the much lower concentrations tested in the main assay . The number of revertants per plate was not increased over the concurr ent solvent control value at any test material concentration, with or without S9 - mix, in any tester strain. The solvent and positive controls induced the appropriate responses in the corresponding strains. There was no evidence of induced mutant colonies o ver background. This study

is classified as Unacceptable/Guideline and does not satisfies the requirements for Test Guideline OPPTS 870.5100; OECD 471 for in vitro mutagenicity (bacterial reverse gene mutation) data. Five strains of S. typhimurium were n ot used in the assay . The study

can not be upgraded.Page 64 of 69

Appendix 3 . Proposed Metabolic Pathway for difenoconazole in RatsPage 65 of 69Page 66 of 69 Appendix 4 Environmental Fate Degradates Table 13.0c . Sum ma ry of Difenoconazole Major Degradates and Maxim um Percent Form ation Observed in the Laboratory and Field Studies. Degradate 1 Max Degradate Concentration (% of applied) and Time (days) to Max Concentration Analyzed Degradates Lab Accumulation in Fish Aqueous

Photolysis 2,3,4 Aerobic Soil Anaerobic Aquatic Aero bic

Aquatic TFD 5 Ground Water CGA 205375 51 - 64% 3.8% (4) 14.8% (360)* 12.6% (175) 11.6% (90) 4.5% (121) A 5.3% (364) B 3.5% (123) C 6.9% (182) D No study CGA 205374 1.1% (14) 2.1 % (272) 0.8% (247) CGA 71019 20.6% (190) 35.9% (350)* CGA - 142856 41.8% (30) 4 * CGA - 107069/ CGA - 71019 12.27% (30) 4 * 12.9% (9) 4 1 Refer to Table I - 2 for name and structure; 2 Difenoconazole was stable under hydrolysis; 3 No meaningful amount of degradates were formed in soil photolysis study ( ≤ 0.2% and only single replicates); 4 In sterile natural water (MRID 46950105 and MRID 42245128); 5 % of the total applied difenoconazole, based on four applications; A under bare soil conditions in GA (MRID 46950126); B under potato production condition in ND (MRID 46950129); C under a bare plot of loam soil in CA (MRID 46950129); D in CA bare loamy sand soil (MRID 42245140) ; and * The max concentration was observed in the last sampling interval.Page 67 of 69 Table 13.0d . Chemical Structures of Difenocon azole and Degradation Products Detected in Subm itted Environm ental Fate Studies. Nam e(s) Structure Known Chemical and Fate Param eters CGA - 169374 Difenoconazole 1 - [2 - [2 - Chloro - 4 - (4 - chlorophenoxy)phenyl] - 4 - methyl - 1,3 - dioxolan - 2 - ylmethyl] - 1H - 1,2,4 - triazole. 1 - [[2 - [2 - Chloro - 4 - (4 - chlorophenoxy)phenyl] - 4 - methyl - 1,3 - dioxolan - 2 - yl]methyl] - 1H - 1,2,4 - triazole. 1 - (2 - [4 - (4 - Chlorophenyoxy) - 2 - chlorophenyl - (4 - methyl - 1,3 - dioxolan - 2 - yl) - methyl]) - 1H - 1,2,4 - triazole. CAS #: 119446 - 68 - 3 Cl O Cl O O C H 3 C H 2 N N NPage 68 of 69 Nam e(s) Structure Known Chemical and Fate Param eters CGA - 205374 [CGA - 176459] 1 - [2 - Chloro - 4 - (4 - chlorophenoxy) - phenyl] - 2 - [1,2,4]triazol - 1 - yl - ethanone 1 - [2 - Chloro - 4 - (4 - chlorophenoxy)phenyl] - 2 - (1H - 1,2,4 - triazol - 1 - yl) - ethanone CAS #: 136815 - 80 - 0 O N N N Cl O Cl

CGA - 205375 [CGA - 211391] 1 - [2 - Chloro - 4 - (4 - chlorophenoxy) - phenyl] - 2 - [1,2,4]triazol - 1 - yl - ethanol alpha - [2 - Chloro - 4 - (4 - chlorophenoxy)phenyl] - 1H - 1,2,4 - triazole 1 - ethanol. CAS #: 117018 - 19 - 6 N N N Cl O Cl O H Mobility data available

CGA - 142856 [1,2,4]Triazol - 1 - yl - acetic acid 1H - 1,2,4 - Triazole - 1 - acetic acid. CAS #: 28711 - 29 - 7 O H O N N N DW assessment completed in 2006 CG A - 71019 1 - H - (1,2,4) - Triazole 1H - 1,2,4 - Triazole 4H - [1,2,4]Triazole CAS #: 288 - 88 - 0 N N N H DW assessment completed in 2006 CGA - 107069 1 - H - (1,2,4) - Triazole - 1 - methanol CAS #: 74205 - 82 - 6 C H 2 N N N O HPage 69 of 69 Nam e(s) Structure Known Chemical and Fate Param eters CGA - 131013 2 - Amino - 3 - [1,2,4]triazol - 1 - yl - propionic acid alpha - Amino - 1H - 1,2,4 - triazole - 1 - propanoic acid CAS #: 86362 - 20 - 1 O H O N H 2 N N N