OFFICE OF CHEMICAL SAFETY AND POLLUTION PREVENTION **UNITED STA TES ENVIRONMENTA**  **L PROTECTION A GENCY** 

WA SHINGTON, D.C. 20460 January 23 , 2012 **PC Code: 129131**  **MEMORANDUM DP Barcode: 3**  **91431 SUBJECT**  **: Fenpyroximate**  **:** Drinking Water Exposure Assessment for Proposed New Uses

on Snap Beans and Tropical Fruits including Avocado and a Proposed Outdoor Use on Cucumbers **FROM :**  Greg Orrick, Environmental Scientist

ERB2 /EFED (7507P) **THROUGH :**  James Lin, Environmental Engineer

Kris tina Garber, Senior Biologist Brian Anderson , Chief ERB2 /EFED (7507P) **TO :**  George Kramer, Ph.D., Senior Chemist

Dana Vogel, Chief RAB1/HED (7509P) Sidney Jackson , Product Manager Barbara Madden , Team Leader , RM Team 5 RIMUERB /RD (7505 P) **1. EXECUTIVE SUMMARY**  This assessment provides estimated drinking water concentrations (EDWC) of fenp yroximate in surface water and in ground water in support of human health risk assessment. Screening EDWCs ( **Table 1** ) of fenpy roximate were generated with FIRST and a Provisional Cranberry

M odel for surface water and with SCI - GROW for ground water. Modeled use patterns are th os e of current and proposed end - use labels that result in the highest exposure . M odel input parameters were chosen according to current guidance ( USEPA , 2009 ). EDWCs reflect exposure in drinking water to the residues of concern of fenpy roximate , which include fenp yroximate parent , its cis isomer M - 1, and its carboxylic acid M - 3, all of which are assumed to have similar toxicity (USEPA, 2003 ). Labeled application buffers to fish - bearing waters were not modeled. The EDWCs listed in this assessment are the result of a coarse screen and do not necessaril y reflect actual exposures that may occur or may have occurred. If the screen ing EDWC s listed in this assessment result in dietary risk exceedances, contact Greg Orrick (703 -2

305 - 6140) of Environmental Risk Branch II (7507P) to request a refined drinking water exposure assessment. **Table 1.1. Maximum Screening Drinking Water Exposure Estimates for**  **Current and Proposed**  **Fenpyroximate Uses**  **A Source (Tier: Model)**  **Use (Maximum Annual**  **Rate) Peak Exposure**  **(μg/L) Annual Mean** 

**Exposure (μg/L)** Surface water (Tier I: FIRST) Ornamentals ( 0.69 lbs a.i./A) 29 1.9 Surface water (Tier I: Cranberry model) Cranberries (0.20 lbs a.i./A) **43 8.6**  Ground water (Tier I: SCI - GROW) Ornamentals (0.69 lbs a.i./A) ≤0.27 A Maximum values in bold. A maximum screening exposure estimate in fish that may be consumed b y humans was also calculated with the Provisional Cranberry Model and KABAM, at 30 mg/kg - bw (ww) . Fenp yroximate is a p yraz ole contact insecticide and miticide that inhibits mitochondrial comple x Ielectron transport. The compound is relatively nonvolatile , lipophilic, and may bioconcentrate in fish . Fenpy roximate is slightly to hardly mobile in soil and may move to surface water through runoff of residues sorbed to suspended sediment . Fenpy roximate degrades mainly via moderate biodegradation in soil and water bodies (half - lives of 23 - 41 day s in aerobic and anaerobic s ys tems). The compound is also rapidly photoisomerized to reach equilibrium with its cis isomer M - 1 and photoly zed in shallow, illuminated water (fenpy roximate half

- life of 1.5 hours; M - 1 half

- life of 10.5 hours). However, the importance of this degradation pathway is expected to be limited because fenp yroximate and its isomer are expected to partition to sediment in water bodies, where aqueous photol ys is is limited. Fenp yroximate’s cis isomer M - 1, its carbox yl ic acid M - 3, and cleavage products M - 6, M 8, M - 11, M - 16, and carbon dioxide are its major transformation products that were isolated in submitted environmental fate studies. M - 1 and M - 3 are included with the parent as residue s of concern. Due to lack of toxicity data, the residues of concern are assumed to have equivalent tox icity (USEPA, 2003 ). Exposure estimates in this assessment reflect total residues of concer n (TRC). EPA Reg. No. 71711 - 4 states “Do not appl y more than 48 fl oz per crop cycle or per growing season, whichever is longer.” This was interpreted as an annual application rate limit. However, the label language is vague and could be misinterpreted . It is recommended to reword this limitation as an annual application rate limit in terms of mass of active ingredient per area. **2. PROBLEM FORMULATION**  This drinking water assessment uses environmental modeling to provide estimates of surface water and ground water concentrations in drinking water source water (pre - treatment) resulting from fenp yroximate use on vulnerable sites . Estimate s reflect drinking water exposure to fenpy roximate residues of concern in drinking water , which include the parent compound , its cis isomer M - 1, and its carboxylic acid M - 3 (chemical names and structures are in **Table A .1**  **, Appendix**  **A** ), on a per molar basis (USEPA, 2003 ). Primary routes of transport to source water3

include spray

drift and runoff of dissolved residues (m ainly M - 3) and residues sorbed to suspended sediment (mainly fenp yr oximate and M - 1) . E xposure in surface water from proposed and current fenp yr oximate uses due to runoff, erosion, and spray drift was assessed with the Tier I screening model , FIRST , and a Provisional Cranberry M odel . Exposure in ground water due to leaching was ass essed with the Tier I screening ground water model SCI - GROW . Exposure in fish consumed b y humans was assessed with the Provisional Cranberry M odel and KABAM. **2.1. Nature of the**  **Chemical** Fenp yroximate is a p yraz ole contact insecticide and miticide that inhibits mitochondrial comple x Ielectron transport. The mode of action blocks cell respiration by blocking formation of adenosine triphosphate (ATP) , causing the target pest to l ose motor control and collapse. Fenp yroximate specifically targets the proton - translocation in NADH:ubiquinone oxidoreductase enzy me blocking ubiquinone reduction. NADH:ubiquinone oxidoreductase, also known as respiratory complex Iof mitochondria, trans fers electrons from NADH to ubiquinone (coenzy me Q) and links this process with translocation of protons across the inner membrane to the cy toplasmic side creating a proton gradient which drives the sy nthesis of ATP. NADH:ubiquinone oxidoreductase enz ym e is comprised of a number of subunits. The number of subunits and total mass of this enzy me and density within mitochondria depends on the organism. It consists of at least 41 different subunits in mammals. The highest number of subunits is 46 for bovine heart mitochondria, whereas bacteria have a minimum of 14 subunits. The total mass of the enzy mes ranges from approximately

500 to 1000 kiloDaltons (kDa), depending on the organism. Sensitivity of an organism to fenp yroximate is expected to be affected by the specific organism NADH:ubiquinone oxidoreductase enzy me affinity

with fenpy

roximate , the density

of the NADH:ubiquinone oxidoreductase enzy me within mitochondria, and the presence of alternative energy pathway s. In addition to the acute respirat ory activity , at sub lethal levels fenp yroximate causes inhibition of molting of all immature stages (as in insect growth regulators), inhibits oviposition, and decreases feeding action. **3. ANALYSIS**  **3.1. Use Characterization**  Fenp yroximate is p roposed for u se on s nap be ans and tropical fruits including avocado . Use on greenhouse - grown cucumbers is also proposed to be expanded to include cucumbers grown outdoors. The proposed use of fenp yroximate on tropical fruits (including avocado) is b y ground applicati on at a maximum single application rate of 0.10 pounds of active ingredient per acre ( lbs a.i./A ) . A second application may be made at this rate a minimum of 14 day s later, to meet a seasonal application rate limit of 0.20 lbs a.i./A per growing season. Supplemental proposed labels propose the same application directions and limitations for snap beans and cucumbers (grown out doors) as for tropical fruits.4

The fenp yroximate uses of maximum aquatic exposure are the current uses on ornamentals and cranberri es. The single and seasonal maximum application rates for ornamentals are 0.343 lbs a.i./A and 0.686 lbs a.i./A, respectively . The seasonal application rate limit wa s inferred based on a label statement to “not apply more than 48 fl oz per crop cycle or per growing season, whichever is longer.” It was assumed that this label statement was intended to be in terms of fl oz per acre per crop cycle or growing season, which results in the seasonal rate limit of 0.686 lbs a.i./A. A reapplication interval was not provided. Aerial application was not disallowed. Use directions for low - growing berries (including cranberries) are similar to those of the proposed uses. **Table 3.1** lists all of the currently labeled and proposed maximum use patterns for fenp yr oximate .5

**Table 3.1. Proposed an**  **d current use**  **s of fenpyroximate EPA**  **Reg. No. Active** 

**Ingredient (%) Use**  **Max. Single**  **App .**  **Rate (lbs a.i./A)**  **Max. Annual**

**Ap p.**  **Rate (lbs a.i./A)**  **App.**

**Interval (d)**  **Application**

**Type Additional Application Directions**  71711 - 4 Fenpyroximate

( 5 %) Ornamentals, Christmas trees,

nonbearing fruit trees and vines 0.343 0.686 A Not stated Aerial or ground Do not use products with the same mo de of

action in consecutive applications. Greenhouse cucumbers and tomotoes 0.105 0.42 14 Ground

71711 - 19 Fenpyroximate

( 5 %) Avocado, black sapote, canistel,

mamey sapote, mango, papaya, sapodilla, and star apple 0.10 0.20 B 14 Aerial or ground Do not apply within 75 feet of fish - bearing

waters. Do not use products with the same mo de of action in consecutive applications. Snap beans 0.20 C Cucumbers Melons (crop subgroup 9A) 0.10 Not stated Lo w - growing berry (crop subgroup 13 - 07G) D 0.10 0.20 C

14 Ground Citrus fruits (crop group 10) east of the Mississippi River 0.20 0.20 B Aerial or ground Do not apply by air except in FL and TX.

Do not apply within 75 feet of fish - bearing waters. For aerial use in FL, do not apply within 150 feet of all aquatic areas. Do not use products with the same mode of action in consecutive applications. Citrus fruits (crop group 10) west of the Mississippi River 0.20 0.40 B Do not apply by air except in TX. Do not apply within 75 feet of fish - bearing waters. Do not use products with the same mode of action in consecutive applications. Cotton 0.10 0.10 B Do not apply within 75 feet of fish - bearing waters. Do not use products with the same mo de of action in consecutive applications. Fruiting vegetables (crop group 8) 0.10 0.20 C Not stated

Grapes 0.10 0.10 B Ground Hops 0.15 0.15 B Mint 0.10 0.20 B 7 Nonbearing fruit trees, nut trees,

and vines 0.10 0.10 B Not stated Ornamentals 0.10 0.10 B Pome fruits (crop group 11) 0.10 0.10 B Not applicable6

**EPA Reg. No.**  **Active**

**Ingredient (%) Use**  **Max. Single**  **App .**  **Rate (lbs a.i./A)**  **Max. Annual**

**Ap p.**  **Rate (lbs a.i./A)**  **App.**

**Interval (d)**  **Application**

**Type Additional Application Directions**  Almonds and pistachios west of the Mississippi River 0.20 0.40 B 14 Tree nuts (crop group 14) excluding almonds and pistachios, we st of the Mississippi River 0.20 0.20 B Tree nuts (crop group 14) east of the Mississippi River 0.10 0.10 B Not applicable A The label vaguely provides a maximum product volume per crop cycle or growing season, whichever is longer . This is interpreted a s an annual rate limit. B The labeled application rate limit is given per growing season , which is interpreted as per year. C The labeled application rate limit is given per crop cycle. These crops are not typically planted more than once per year in the same field (USEPA, 2007). Therefore, the application rate limits per crop cycle were used as annual rate limits. D The low - growing berry crop subgroup (13 - 07G) includes cranberries.7

**3.2. Fate and Transport Characterization**  Fenp yroximate [ tert- b utyl ( E ) - α - (1,3 - dimethyl - 5 - phenoxy py razol - 4 - yl methyleneaminooxy) - p - toluate ; CAS# 134098 - 61 - 6 ] is a trans stereoisomer) and a tert- butyl ester (chemical structure is in **Appendix A** ) . The compound is relativel y nonvolatile, lipo philic, and slightly to hardl y mobile in s oil . Fenpyroximate degrades mainl y via moderate biodegradation in soil and water bodie s (half - lives of 23 - 41 day s in aerobic and anaerobic sy stems) . The compound is also rapidly photo isomerized to reach equilibrium with its cis isomer M - 1 and photolyzed i n shallow, illuminated water ( fenp yr oximate half - life of 1.5 hours ; M - 1 half - life of 10.5 hours ) . However, the importance of this degradation pathway is expected to be limited because fenp yroximate and its isomer are expected to partition to sediment in water bodies, where aqueous photoly sis is limited. Fenpyroximate does not hydroly ze readil y and may bioconcentrate in fish . Fenpy roximate’s cis isomer M - 1 , its carbo xylic acid M - 3 , and cleavage product s M - 6, M - 8 , M - 11, M - 16, and carbon dioxide are its major transformation products (chemical names and structures are in **Appendix A** ). Fenp yroximate is not expected to move to ground water but may move to surface water bodies via spray

drift and runoff of residues sorbed to suspended sediment. **Table 3.2**  summarizes the submitt ed chemical and environmental fate data for fenp yr oximate. **Table 3.2**  **. Chemical Properties and Environmental Fate Param**  **eters of Fenpyroximate**  **Parameter Value**  **Source Selected Physical/Chemical Parameters**  Molecular mass (molecular formula) 421.50 g/mol ( C 24 H 2 7N 3 O 4 ) (Calculated) Vapor pressure (25 °C) 5.6 x 10 - 8 torr MRID 44781003 Aqueous solubility (25  C) pH 5: 0.023 mg/L pH 7: 0.026 mg/L pH 9 : 0.034 mg/L MRID 44781003 Henry’s Law Constant (25 °C , pH 7 ) 1.2 x10 - 6 atm - m3 /mol (Calculated) Log octanol - to -water partition coefficient (log K OW) 5.01 MRID 44781003 Dissociation constant (pKb ) Not determined MRID 4 4781003 **Persistence** Hydrolysis half

- life (25  C) pH 5: 180 d pH 7 : 226 d pH 9: 221 d MRID 44847909 Aqueous photolysis half

- life (25  C) 1. 8 hrs (0.1 5 solar days) MRID 4 4781016 Soil photolysis half

- life (25  C) 24 d MRID 4 5649705 Aerobic soil metabolism half - life (25 °C) 28, 41 d MRID 4 5187901/ 45649706 39 d MRID 4 6158501 Anaerobic aquatic metabolism half - life (25  C) 33 d MRID 4 5649707 Aerobic aquatic metabolism half - life (2 0  C) 23, 34 d MRID 475214068

**Parameter Value**  **Source Mobility**  Freundlich soil -water partition coefficients (KF ); Freundlich organic carbon -normalized coefficients (KFOC ) 83, 93, 175, 290, 1, 370 L/kg; 7,5 50, 18,600, 41,400, 44,000, 58,300 L/kg OC MRID 45649709 **Field Dissipation** Terrestrial field dissipation half - life 1 d (German sandy silt loam),

11 d (German sandy loam), 12 (German loamy sand), 24 d (German sandy loam) MRID 4 5649710/ 45649711 3.6 d (Commerce silt loam, AR), 4.1 d ( Cajon sandy loam, CA), 15 d (Norfolk sandy loam, NC) MRID 4 5649712/ 45734203 **Fish Bioconcentration** Fish bioconcentration factors (steady - state, total residues) 770 - 1100 (edible), 2800 - 4100 (inedible), 1800 - 2700 (whole fish) MRID 48381102 **3.2.1. Transport and Mobility**  Fenp yroximate will not significantl y volatilize despite having a low solubility in water (0.023 - 0.034 mg/L at pH 5 - 9, 25 °C ; MRID 44781003 ) and moderate Henry ’s Law Constant (1.2 x 10 - 6 atm - m 3 /mol ) because of its low vapor pressure ( 5.6 x 10 - 8 torr at 25 °C ; MRID 4 4781003 ) and high K OW of 100,000 (log KOW of 5.0 1 ; MRID 44781003). Minimal volati lity was observed in the environmental fate studies because of high sorption to soil. Fenp yroximate is slightl y to hardl y mobile in soil , with KFOC values of 7,550 - 58,30 0 L/kg OC (MRID 45649709 ). Sorption to soil correlates with the organic carbon fraction in soil ( i.e . , the coefficient of variation across five soils for KFOC ( 60 %) is less than that for KF ( 136 %) ) . The compound is not expected to move to ground water via leaching but may be sorbed to suspended sediment in runoff feeding surface water bodies. **3.2.2. Degradation**  Fenp yroximate slowly

hydroly zes at environmental pH values, with half - lives of 180 - 226 day s at pH 5 - 9 ( MRID 44847909 ). In contrast, fenpy roximate is rapidly photo isomerized to reach equilibrium with its cis isomer, M - 1, and photoly zed in water, with a half

- life of 1 . 8 hours (MRID 44781016) . The phot oly sis half - life of M - 1 was 12 hours. M - 11 was the predominant photoproduct of fenp yr oximate and M - 1. The importance of phototransformation is expected to be limited, however, because fenp yr oximate and its isomer are expected to partition to sediment in water bodies, where aqueous photoly sis is limited. F enp yroximate moderately degraded in aerobic soil with half - lives of 28, 39, and 41 day s (MRID 45187901/456 49706, 46158501) . M - 3, M - 8, and carbon dioxide were major degradates in soil . Inaerobic aquatic sy stems, the compound moderatel y degraded at similar rates, with half - lives o f 23 and 34 day s (MRID 47521406 ). M - 3, M - 8, and M - 11 were major degradates in9

these sy stems . Un der anaerobic aquatic conditions , fenp yroximate degraded at a simi lar rate, with a half

- life of 33 days (MRID 45649707). M - 3, M - 8, M - 11, and M - 16 were the major degradates in anaerobic conditions . **3.2.3. Field Studies**  Fenp yroximate dissipated under terrestrial field conditions with half - lives of 1 - 24 day s (MRID 45649710/ - 11 and 45649712/45734203) , based on the results of three bare ground field experiments conducted in the United S tates and four conducted in Germany . These field dissipation half

- lives range from being shorter than to similar to laboratory - derived degradation half - lives in soil (28 - 41 day s). At the U . S . sites, half - lives of fenpy

roximate + M - 1 + M - 3 were 35 day s in the silt loam soil in Arkansas, 15 day s in the sandy loam soil in California, and 43 day s in the sandy

loam soil in North Carolina. Fenpy roximate plus M - 1 was not detected below the 15 - cm soil depth, and was not detected at any s ite after 61 days posttreatment. The soils were also anal yz ed for the tran sformation products M - 3, M - 8, and M - 11. M - 8 and M - 11 were not detected at any of the sites. M - 3 was detected in all three U.S. studies. At the German sites, fenp yroximate + M - 1 + M - 3 dissipated with half - lives of 3 to 37 day s. Fenpy roximate was not det ected below the 10 - cm depth, except at one site at one sampling interval, and was not detected at any site after 56 days posttreatment. **3.2.4. Fish Bioconcentration**  Fenp yroximate may

bioaccumulate in aquatic organisms , with fish bioconcentration factors of up t o 1100, 4100, and 2700 for edible, inedible, and whole fish tissues , respectively ( factors are uncertain due to high total organic carbon concentrations in the test sy stems; MRID 48381102) . Only one concentration of fenpy roximate was studied and degradati on was not monitored in this study . Depuration half - lives for the edible, inedible, and whole fish tissues were 5.2 - 5.3 day s . The r espective depuration rate co nstant for whole fish (kT of 0 .131 d - 1 ) was well above the sum of elimination constants estimated b y KABAM (k2 +kE +k G of 0.035 d - 1 ), which indicates that the compound was metabolized in fish (KABAM neglects metabolism by default). The KABAM - estimated BCF for fenp yr oximate was 4900, which is higher than the study- derived values of 1800 - 2700 for whole fish. However, the KABAM - estimated BCF for fenp yroximate based on the contribution of fish concentrati ons due to respiration is reduced from 3900 to 1100 when a metabolism rate constant (kM ) for small t o large fish of 0.096 d - 1 is used . Th is metabolism rate constant was calculated b y s ubtracting the sum of elimination rate constants estimated by

KABAM (k2 + kE +k G of 0.035 d - 1 ) from the study- derived depuration rate constant (k T of 0.131 d - 1 ). The BCF estimate of 110 0 is lower than the study- derived BCF values of 1800 - 2700, which indicates that the calculated metabolism rate constant may be overestimated. **3.2.5. Environmental Degradates**  Major identified environmental transformation products of fenp yroximate are its cis isomer M - 1 , its carbox yl ic acid M - 3 , and cleavage products M - 6, M - 8, M - 11, M - 16, and carbon dioxide (chemical names and structures are in **Appendix A** ). **Figure A.1 of Appendix A** illustrates the transformation pathway of fenpy roximate in the envi ronment.10

M ajor organic degradates of fenp yroximate (and M - 1) tend to have higher mobility in soil than the parent compound (and its isomer) . Mean KFOC values for M - 3, M - 8, and M - 11 are 660, 90 , and 611 L/kg OC (n=4; MRID 45649708 and 47521401 ). As expected for a carbox yl ic acid, M - 3 is orders of magnitude more soluble in water (solubility of ≥25 mg/L at 25°C; MRID 45649708) than fenp yr oximate. **3.2.6. Residues of Concern**  The Metabolism Assessment Review C ommittee ( MARC ) of the Health Effects Divisio n included as residues of concern in drinking water, fenp yroximate parent , its cis isomer M - 1, and its carbox yl ic acid M - 3 ( USEPA, 2003 ) . Due to the structural similarity of the compounds and the lack of toxicity

data , they

are assumed to have eq

uivalent toxicity . Drinking water exposure to the residues of concern is estimated using available chemical properties and environmental fate data. A total residues of concern (TRC) approach wa s used because the residues are assumed to have equivalent toxicity and degradation studies were not performed on M - 3 . **Table 3.3**  lists the environmental fate parameters for the fenp yroximate TRC that are relevant for exposure modeling . Degradation half - lives reflect regression of the total residues at each study interval. Batch equilibrium data were available for M - 3 (MRID 45649708 ). Chemical properties of the parent compound were used to represent those of the residues of concern due to the lack of data on M - 3. **Table 3.3 . E**  **nvironmental fate parameters of the total residues of concern**  **Parameter Value**  **Source Persistence**  Hydrolysis half

- life (25  C) Stable (pH 5 , 7 , 9 ) MRID 44847909 Aqueous photolysis half

- life (25  C) 12 hrs (0.98 solar days) MRID 4 4781016 Aerobic soil metabolism half - life (2 5  C) 31, 47 d MRID 45187901/ 45649706 53 d MRID 46158501 Aerobic aquatic metabolism half - life (20  C) 37, 4 4 d MRID 47521406 Anaerobic aquatic metabolism half - life (25  C) 149 d MRID 4 5649707

**Mobility** Range of Freundlich organic carbon normalized partition coefficients (KFOC ) Parent: 7,550 - 58,300 L/kg OC (n=5) MRID 45649709 M - 3 : 124 - 1,310 L/kg OC (n=4) MRID 4564970811

**3.3. Drinking Water Exposure Modeling**  **3.3.1. Models**  **3.3.1.1. FIRST**  The FQPA Index Reservoir Screening Tool (FIRST v1.1.1, Mar. 25, 2008; USEPA, 2008 ) is a Tier I screening model that simulates the upper - end exposure of the standard water body , the Index Reservoir, to pesticide residues in runoff and spray drift from an application within the standard watershed. Peak and annual mean EDWCs are generated to e stimate acute and chronic exposure. The Index Reservoir covers 5.2 hectares (ha) with an average depth of 2.74 meters (m) in a standard watershed of 172.8 ha. A more detailed description of the index reservoir watershed can be found in Jones et al ., 2010 . The FIRST model and user’s manual are available from the EPA Water Models web - page (USEPA, 2012 ).

**3.3.1.2. Provisional Cranberry Model**  The Provisional Cranberry Model is a provisional refinement to the Tier I Rice Model (v1.0, May

8, 2007). Refinements include the addition of simple degradation processes in dry and flooded conditions and a water depth of twelve inches, rather than the water depth of four inches used in the rice model. These modifications allow estimation of screening - level peak and annual m ean EDWCs of fenp yroximate residues of concern that may occur in untreated surface water used as drinking water following use on cranberries. The Tier I Rice Model relies on an equilibrium partitioning concept to provide conservative estimates of EDWCs re sulting from application of pesticides to rice paddies. When a pesticide is applied to a rice paddy, the model assumes that it will instantaneously partition between a water phase and a sediment phase. The model does not account for pesticide degradation , mass transfer between the aqueous phase and the sediment, volatilization, dilution, or other dissipation processes. The Tier I Rice Model was calibrated to generate estimates that are consistent with or conservative for dissolved concentrations measured within rice paddies and in discharged paddy water. The model was not evaluated or calibrated for concentrations measured in sediment and does not account for residues bound to suspended sediment. Guidance for using the Tier I Rice Model may be found on the U.S. Environmental Protection Agency (EPA) Wat er Models web - page (USEPA, 2012 ). The Provisional Cranberry Model is based on the same assumptions as the Tier I Rice Model, with the addition of degradation processes in dry and flood conditions and a water depth of twelve inches in the flooded cranberry bog. Degradation of fenpy roximate residues of concern is assumed to occur predominantl y via aerobic microbial metabolism , whether on dry cranberry bog soil or in bog flood water. The cranberry

bog water depth of twelve inches is a maximum depth recommended by the Cape Cod Cranberry

Growers Association (2001). Previous assessments of mesotrione uses that employed the Provisional Cranberry Model assumed a water depth of eighteen inc hes (DP barcode 339984, USEPA, 2004; DP barcode 325840, USEPA, 2006a), which is within the range12

of water depths traditionally used. However, modern water conservation pressures are causing cranberry growers to reduce the flood depth to fewer inches above the vertical cranberry branches, which grow up to eight inches high (Cape Cod Cranberry Growers Association, 2001; The Cranberry

Institute, 2008). Therefore, a twelve - inch deep flood is a reasonable refinement to model assumptions. The equations used in the Provisional Cranberry Model are briefl y described in **Appendix C**  . EDWCs generated with the Provisional Cranberry Model have not been evaluated. However, the Tier I Rice Model is expected to generate conservative EDWCs that exceed peak measured concentrations of pesticides in water bodies well downstream of rice paddies by less than one order of magnitude to multiple orders of magnitude.

**3.3.1.3. SCI**  **- GROW**  Screening Concentration in Ground Water (SCI - GROW v2.3, Jul. 29, 2003; USEPA, 2002) is a regression mo del used as a screening tool to estimate pesticide concentrations found in ground water used as drinking water. SCI - GROW was developed by fitting a linear model to ground water concentrations with the Relative Index of L eaching Potential (RILP) as the ind ependent variable. Ground water concentrations were taken from 90 - day average high concentrations from Prospective Ground Water studies. The RILP is a function of aerobic soil metabolism and the soil - water partition coefficient. The output of SCI - GROW represents the concentrations of pesticide residue that might be expected in shallow unconfined aquifers under sandy soils, which is representative of the ground water most vulnerable to pesticide contamination and likely

to serve as a drinking water source . The SCI - GROW model and user’s manual is also available from the EPA Water Models web - page (USEPA, 201 2). FIRST , the Provisional Cranberry

Model, and SCI - GROW were used to estimate screening - level exposure of drinking water sources to total residues of concern of fenpy roximate . **3.3.2. Input Parameters**  **3.3.2.1. FIRST**  Inp ut parameters for FIRST follow in **Table 3.**  **4** . The modeled use pattern represents the current or proposed use pattern of highest estimated exposure , which is the current use on ornamentals (two aerial application s per year at 0. 343 lbs a.i./acre ). A reapplication interval for use on ornamentals is not stated on the label; however, the label prohibits consecutive applications of products with the same mode of action. Therefore, a reapplication i nterval of 6 day s was modeled, assuming that treatments may be necessary every 3 day s, with an alternative chemistry applied between applications of fenpy roximate. **Table 3.4**  **. FIRST input parameters for total residues of fenpyroximate**  **A Input Parameter**  **Value Comments**  **Source** Application rate (lbs a.i./A) 0. 343 Maximum proposed single application rate EPA Reg. No. 71711 - 4 Number of applications per year 2 Number of applications at the maximum application rate that achieves the maximum rate per growing season . EPA Reg. No. 71711 - 413

**Input Parameter Value**  **Comments Source**  Application interval (d) 6 Assumed in the absence of label directions (see text for discussion). EPA Reg. No. 71711 - 4 Percent cropped area 87 % Default agricultural PCA Jones et al. , 2010 a Organic carbon partition c oefficient (K OC ) (L/kg OC ) Parent: 34,000 M - 3: 649 Represents the mean KFO C values for

parent (n=5 ) and M - 3 (n=5 ) . MRID 45649708 , 45649709 Aerobic soil metabolism half - life (days) 56 Represents the upper 90% confidence bound on the mean of three half - lives for the residues of concern. MRID 45187901/ 45649706, 46158501 Wetted in? No Not required. EPA Reg. No. 71711 - 4 Method of application Aerial Application method assumed in the absence of label directions for ornamentals . EPA Reg. No. 71711 - 4 Solubility in water (ppm) Parent: 0.026 M - 3: 25 Upper limit for parent and lower limit

for M - 3 in pH 7 water. MRID 44781003, 45649708 Aerobic aquatic metabolism half - life (days) 51 Represents the upper 90% confidence bound on the mean of two half - lives for the residues of concern. MRID 47521406 Aqueous photolysis half

- life (days) 0.975 Represents the maximum half - life for the residues of concern . MRID 44781016 A Source data are in **Tables 3.1 -**  **3 .**  **3** . Chemical property input values were chosen in accordance with current input parameter guidance (USEPA, 2009 ). Based on anal ys is of total residues of concern, the 90% confidence bound on the mean half

- life for aerobic soil metabolism ( 56 d) and for aerobic aquatic metabolism (51 d) were selected. Water solubility limits and KOC input s representing the mean values for the parent compound (n=5) and for M - 3 (n=5 ) were modeled separatel y to bracket the potential exposure to residues of concern, representing cases of 1) no M - 3 formation and 2) complete conversion of residues to M - 3, which is more soluble in water and more mobile in soil than fenp yroximate and M - 1. Standard percent cropped areas (PCA) are used as conservative default estimates of the ex tent of watershed on which agricultural crops of unknown specific PCA are grown ( Jones et al. , 2010 a ). For this screening assessment, the default national PCA value of 87% was used to adjust exposure estimates because fenp yroximate is labeled for use on a variety of agricultural crops as well as ornamentals, many of which are agricultural, such as nonbearing fruit trees and vines . **3.3.2.2. Provisional Cranberry Model**  The current use of fenpy

roximate on cranberries at the maximum proposed application rate (0. 1 0 lbs a.i./acre ) may occur no more than two times per year , resulting in an annual application rate limit of 0.20 lbs a.i./acre (EPA Reg. No. 71711 - 19) . The minimum reapplication interval of 14 day s stated on the proposed label was modeled; however, this limitation is not on the current label . If this reapplication interval is not implemented, then exposure should be reanal yz ed assuming a shorter reapplication interval.14

Cranberry

bogs are often flooded on the night before harvesting. EPA Reg. No. 71711 - 19 states not to apply

fenpy roximate to cranberries within 1 day of harvest. Therefore, the single application rate (0.10 lbs a.i./acre ) was aged on dry soil with the Provisional Cranberry Model for two durations that are 14 day s apart : 16 and 2 day s. Th e resulting residues (in lbs a.i./acre ) were summed together for each residue and input into the flooded component of the model to estimate exposure in bog tailwater following harvest. Peak and annual mean EDWCs were calculated beginning three day s after flooding to account for transport time to a down - gradient drinking water intake following release of bog tailwater not long after flooding. Chemical property input values were calculated for modeling as was done for FIRST. Model input parameters are listed in **Table 3. 5**  . As stated above, the default national PCA value of 87% was used to adjust exposure estimates in this assessment. **Table 3.5 . Provisional Cranberry Model input parameters for total residues of**  **fenpyroximate A**  **Input Parameter Value**  **Comments Source**  Application r ate (lbs a.i./A) 0.10 Maximum p roposed single application rate EPA Reg. No. 71711 - 19 Applications per year 2 Maximum number of applications per year at the maximum s ingle application rate EPA Reg. No. 71711 - 19 Application - to -h arvest i ntervals (d) 2 , 1 6 Intervals between applications and harvest are discusse d in the text above. EPA Reg. No. 71711 - 19 Organic carbon partition c oefficient (K OC ) (L/kg OC ) Parent: 34,000 M - 3: 649 Represents the mean KFOC values for

parent (n=5) and M - 3 (n=5). MRID 45649708, 45649709 Aerobic soil metabolism h alf - life (days) 56 Represents the upper 90% confidence bound on the mean of three half - lives for the residues of concern. MRID 45187901/ 45649706, 46158501 Aerobic a quatic metabolism h alf - life (days) 51 Represents the upper 90% confidence bound on the mean of two half - lives for the residues of concern. MRID 47521406 A Source data are in **Tables 3. 1**  **- 3**  **. 3**  .

**3.3.2.3. SCI**  **- GROW**  Input parameters for the SCI - GROW model appear in **Table 3.**  **6** . The lowest Freundlich organic carbon partition coefficient s for fenpy roximate (KFO C = 7550 L/k g OC ) and M - 3 (KFOC = 124 L/kg OC ) were selected to bracket exposure between residues of undegraded fenp yroximate and its isomer and residues of the carbox yl ic acid M - 3 (as was explained for modeling with FIRST) . The m ean total residue half - life (44 d) from three aerobic soils was selected to approximate the biodegradation kinetics of the residues of concer n in aerobic soil environments.15

**Table 3. 6**  **. SCI**  **- GROW input parameters for total residues of**  **fenpyroximate .**  **A Input Parameter**  **Value Comments**  **Source** Application rate (lbs a.i./A) 0.343 Maximum proposed single application rate EPA Reg. No. 71711 - 4 Number of applications per y ear 2 Number of applications at the maximum application rate that achieves the maximum rate per growing season. EPA Reg. No. 71711 - 4 Organic carbon partition c oefficient (K OC ) (L/kg OC ) Parent: 7 , 55 0 M - 3: 124 Represent the lowest KFOC values , due

to greater than 3 - fold variation . MRID 45649708, 45649709 Aerobic soil metabolism h alf - life (days) 44 Represents the mean of three half - lives for the residues of concern. MRID 45187901/ 45649706, 46158501 A Source data are in **Tables 3.1 -**  **3.3** . **3.3.3. Modeling Results**  Screening estimates generated for drinking water exposure assessment are listed in **Table 3.**  **7** . The current use on ornamentals was the use resulting in maximum surface water and ground water exposure using the FIRST and SCI - GROW models, as described above. The current use on low growing berries was the use of maximum surface water exposure using the Provisional Cranberry Mo del . Model ed e stimates are peak and annual mean values for total residues, using a KOC input for either fenpy roximate parent or M - 3 , assuming complete conversion. Model input/output data and filenames for these estimates are attached in **Appendix B**  . **Table 3.7 .**  **Maximum Drinking Water Exposure Estimates for the**  **Current and Proposed**  **Use s**  **of Fenpyroximate**  **. A**  **Source (Tier: Model) K** **OC input**  **(L/kg OC**  **) Peak Exposure** 

**(μg/L) B**  **Annual Mean**

**Exposure (μg/L) B**  Surface w ater (Tier I: FIRST) Parent: 34,000 11 0.38 M - 3: 649 **29 1.9**  Surface water (Tier I: Cranberry model) Parent: 34,000 3.6 0.72 M - 3: 649 **43 8.6**  Ground w ater (Tier I: SCI - GROW) Parent: 7,55 0 ≤0. 005 M - 3: 124 **≤ 0.27**  A Maximum values per model are in bold . B Surface water concentrations calculated by FIRST are 1 - in - 10 - year values . Ground water concentrations calculated by SCI - GROW are the highest 90 - day running average. Exposure estimates for M - 3 were substantially higher than those for the parent compound. In surface water, the maximum e xposure estimates for M - 3 following use on cranberries were a peak of 43 μ g/L and an annual average of 8.6 μg/L . M aximum exposure esti mates for M - 3 following use on ornamentals were lower, with a 1 - in - 10 - ye ar peak of 29 μg/L and a 1 - in - 10 - ye ar annual average of 1.9 μg/L . The Tier I screening EDWC for M - 3 in ground water wa s 0.27 μ g/L.16

**3.3.4. Drinking Water Treatment**  The Office of Pesticide Programs (OPP) does not have direct data on the effects of drinking water treatment on fenp yroximate. Flocculation and sedimentation removal may be effective at reducing fenpy roximate concentrations. Carbon filtering is also likel y to reduce fenp yroximate concentrations due to the compound’s affinity to organic carbon. Carbon filtering may

be less effective at r educing M - 3 concentrations , however . Because of the absence of data on fenp yroximate and M - 3 , the effects of drinking w ater treatment were not considered in this assessment. **3.4. Fish Exposure**  A sc reening estimate of fenpy roximate residues of concern in potentiall y human consumed fish was generated using the KOW (based) A quatic B io A ccumulation M odel (KABAM v.1.0) and the Provisional Cranberry Model. Provisional Cranberry

Model inputs are as listed in **Table 3.5** for drinking water exposure modeling, with the KOC input of 34,000 L/kg OC for the parent compound ( and M - 1 ) . M - 3 was included as a residue of concern in fish because its log KOW value (4.25) estimated by EpiSUITE (v4.1) is greater th an three . Whether it is included as a residue of concern does not substantially change fish concentrations. The cranberry model output was 3.4 μg/L, which is the 30 - day mean water concentration beginning 3 day s after bog flooding . A 30 - day mean concentration was used because the 30 day s is the time to steady- state estimated by KABAM. A 3 - day

period between flooding and release of bog water was assumed to occur to allow for h arvesting. KABAM was used to estimate screening concentrations of fenp yroximate residues of concern in large fish . The bioaccumulation portion of KABAM is based on an aquatic food web bioaccumulation model published by Arnot and Gobas (2004) that relies on a pesticide's octanol water partition coefficient (KOW) to estimate uptake and elimination constants through respiration and diet of aquatic organisms in different trophic levels. Pesticide tissue concentrations in aquatic organisms are calculated for different trophic levels of a food w eb through diet and respiration . The KABAM model and user’s manual are available from the EPA Water Models web - page (USEPA, 2012 ). KABAM was run in default mode (see user’s guide for full descriptio n), with a log KOW of 5.01 , a KOC of 34,000 L/kg OC , a metabolism rate constant (kM ) for small to large fish of 0.096 d - 1 , a study- derived water temperature of 22°C, and the single surface water and pore water 30 - day mean concentration of 3.4 μg/L, which wa s generated with the Provisional Cranberry Model. The metabolism rate constant was calculated b y s ubtracting the sum of elimination rate constants estimated by

KABAM (k2 + kE +kG of 0.035 d - 1 ) from the study- derived depuration rate constant (kT of 0.131 d - 1 ) . This was done because KABAM does not account for metabolism by default . The resulting fenp yroximate residues concentration in large fish was 7.1 mg/kg - bw (ww) . If fenp yr oximate residues were to completely convert to M - 3 in the environment, the residue concentration in large fish would be estimated at 30 mg/kg - bw (ww). This is the result of entering the K OC input of 649 L/kg OC for M - 3 into the Provisional Cranberry Model and17

KABAM and entering the resulting 7 - day mean concentration in cranberry bog water (47 μg/L) and the EpiSUITE - estimated log KOW value of 4.25 into KABAM, leaving all other input values for the modeling of fenpy roximate unchanged. However, complete conversion to M - 3 is unlikely in the environment because M - 3 onl y formed up to 1 5% and 25% of the applied in the submitted soil biodegradation (MRIDs 45649706 and 46158501 ) and aquatic biodegradation (MRID 47521406 ) studies, respectivel y. These screening estimate s represent high - end concentration s in fish that may occur following rel ease of cranberry bog water into a stagnant fish - bearing water body . Dissipation processes such as dilution, flow downstream, and partitioning to water body s ediment were neglected. If these screening concentration s in fish result in risk concerns, then exposure assessment refinements are needed (the concentration s do not necessaril y reflect actual exposure that may occur or may

have occurred). **4. CONCLUSIONS**  Screening drinking water exposure estimates for proposed fenp yr oximate use s on snap beans and tropical fruits including avocado and an outdoor use on cucumbers are represented b y the maximum use pattern s on cranberries and ornamentals ( **Tables 1.1** and **3.7** ). The total residues of concern of fenpy roximate include fenpy

roximate parent , its cis isomer M - 1, and its carbox yl ic acid M - 3, all of which are assumed to have similar toxicity . Maximum s creening Tier I e xposure estimates in ground water ( 0.27 μg/L ) are two orders of magnitude less than those in surface water ( 29 - 43 μg/L ). The maximum screening e xposure estimate in fish that may be consumed b y humans is 30 mg/kg - bw (ww) . **5. LITERATURE CITATIONS**  Arnot, J.A. and F.A.P.C. Gobas. 2004. A food web bioaccumulation model for organic chemicals in aquatic ecosystems. Environmental Toxicology and Chemistry , **23** (10): 2343 - 2355 Cape Cod Cranberry Growers Association. 2001. Cranberry Water Use: An Information Fact Sheet. June, 2001. Online at: http://www.cranberries.org/pdf/wateruse.pdf . Accessed Jan. 10, 2012 . Jones, R. D., K. Costello, J. Hetrick, J. Lin, R. Parker, N. Thurman, C. Peck. 2010. Development and Use of the Index Reservoir in Drinking Water Exposure Assessments. U.S. Environmental Protection Agency, Office of Pesticide Programs. Ap ril 15, 2010. Online at: http://www.epa.gov/oppefed1/models/water/index_reservoir_dwa.html Jones, R. D., K. Costello, J. Hetrick, J. Lin, R. Parker, N. Thurman, C. Peck, G. Orrick. 2010 a . Development and Use of Percent Cropped Area Adjustment Factors in Drinking Water Exposure Assessments. U.S. Environmental Protection Agency, Office of Pesticide Programs. September 9, 2010. Online at: http://www.epa.gov/oppefed1/models/water/pca_adjustment_dwa.html The Cranberry Institute. 2010 . About Cranberries. 2003 - 2010 . Online at: http://www.cranberryinstitute.org/about_cranberry.htm . Accessed Jan. 10, 2012 . United States Environmental Protection Agency ( USEPA) . 2002. SCI - GROW User’s Manual. U.S. Environmental Protection Agency, Office of Pesticide Programs, Environmental Fate and Effects Division. Nov. 1, 2001; revised Aug. 23, 2002.18

USEPA. 2003. Stokes, J. Fenpyroximate: Conclusion and Briefing Memorandum for 07/09/03 Meeting of the Health Effects Divisi on (HED) Metabolism Assessment Review Committee (MARC). DP barcode 292639. U.S. Environmental Protection Agency, Office of Prevention, Pesticides, and Toxic Substances, Health Effects Division. Internal memorandum. Aug. 12, 2003. USEPA. 2008. FIRST User’s Manual. Version 1.1.1. U.S. Environmental Protection Agency, Office of Pesticide Programs, Environmental Fate and Effects Division . Mar. 26, 2008. USEPA. 2009. Guidance for Selecting Input Parameters in Modeling the Environmental Fate and Transport of Pesticides. Version 2.1. U.S. Environmental Protection Agency, Office of Pesticide Programs, Environmental Fate and Effects Division, Oct. 22, 2009. Onl ine at: http://www.epa.gov/oppefed1/models/water/input_parameter_guidance.htm USEPA. 201 2 . Water Models. U.S. Environmental Protection Agency, Pesticides: Science and P olicy , Models and Databa ses. Last updated Jan. 10, 2012 . Online at: http://www.epa.gov/oppefed1/mo dels/water/ **5.1. Submitted**  **Environmental Fate Studies**  **MRID Citation Reference**  44781003 Todhunter , J.; Hill, J. (1999) Fenpyroximate -- Technical Active Ingredient (TGAI) and Fenpyroximate

5% SC (End Use Product): Product Chemistry, Series 63: Lab Project Number: NNI - FENPY - 99 - 003. Unpublished study prepared by SRS International Corporation. 19 p. 4478 1016 Swanson, M. (1993) Direct Photolysis of Pyrazole - (carbon - 14) - Fenpyroximate in a Buffered Aqueous

Solution Under Artificial Sunlight: Final Report: Lab Project Number: SC910077: SC910089: E - 4015. Unpublished study prepared by Battelle Memorial Institut e. 126 p. 44847909 Saxena, A.; McCann, D. (1992) Hydrolysis of Pyrazole - (carbon - 14) - Fenpyroximate in Buffered

Aqueous Solutions: Final Report: Lab Project Number: SC900192. Unpublished study prepared by Battelle Memorial Institute. 97 p. 44847910 Rom

bke, J.; Brodesser, J. (1992) Determination of the Degradation in Soil of Fenpyroximate: Final Report: Lab Project Number: E - 4020: BE - ME - 107 - 90 - 01SAB1. Unpublished study prepared by Battelle Europe. 46 p. 44847911 McCann, D. (1992) Sorption/Desorption of Pyrazole - (carbon - 14) - Fenpyroximate on Soils by the Batch

Equilibrium Method: Final Report: Lab Project Number: SC9101024. Unpublished study prepared by Battelle Memorial Institute. 124 p. 45187901 Funayama, S.; Atsuko, H.; Izawa, Y. (1990) Degradati on of (Pyrazole - 14C) and (Benzyl - 14C)

Fenpyroximate in Soils Under Laboratory Conditions: Lab Project Number: E - 4005. Unpublished study prepared by Nihon Nohyaku Co., Ltd. 52 p. 45649705 Concha, M. (2001) Photodegradation of (Carbon - 14) Fenpyroximate in/ on Soil by Artificial Light: Lab

Project Number: E - 4030: 870W - 1: 870W. Unpublished study prepared by PTRL West, Inc. 188 p. 45649706 Maks, M. (2002) Degradation of Pyrazole - (Carbon - 14) and Benzyl - (Carbon - 14) Fenpyroximate in Soils

Under Laboratory Conditions: Lab Project Number: E - 4005. Unpublished study prepared by Nichino America, Inc. 8 p. 45649707 McKemie, T.; Shepler , K. (2001) Anaerobic Aquatic Metabolism of (Carbon 14) Fenpyroximate: Lab

Project Number: 889W - 1: 889W: E - 4031. Unpublished study prepared by PTRL West, Inc. 232 p. 45649708 Concha, M. (2002) Soil Adsorption/Desorption of (Carbon 14) M - 3 by the Batch Equilibrium Method:

Lab Project Number: 1045W. Unpublished study prepared by PTRL West, Inc. 132 p. 45649709 Concha, M. (2002) Soil Adsorption/Desorption of (Carbon 14) Fenpyroximate by the Batch Equilibrium

Method: Lab Project Number: 987W: E - 4033. Unpubl ished study prepared by PTRL West, Inc. 151 p.19

**MRID Citation Reference**  45649710 Burstell, H.; Sochor, H. (1994) Fenpyroximate Water Miscible Suspension 50g/l: Investigation of the

Degradation Behaviour in Soil Under Field Conditions: Lab Project Number: E - 4028: ER91DEU824: A537 73. Unpublished study prepared by Hoechst Schering AgrEvo GmbH. 55 p. 45649711 Specht, W. (1993) Determination of the Residues of Fenpyroximate (HOE 094552), M - 1 (HOE 112573)

and M - 3 (HOE 112721) in Soil: Lab Project Number: HOE - 9107: 93615/91: A53773. Unpublished study prepared by Chemische Laboratorien GMBH. 146 p. 45649712 Baker, F.; Mickelson, K.; Hiler, R. (2001) Field Soil Dissipation of Fenpyroximate in Bare Ground in

North Carolina, Arkansas, and California: Lab Project Number: 803W - 1: 803W: E - 4 032. Unpublished study prepared by Research for Hire. 253 p. 45734203 Hiler, R. (2002) Quantification of Metabolites M - 3, M - 8, and M - 11 in Soil from Field Soil Dissipation

of Fenpyroximate in Bare Ground in North Carolina, Arkansas and California: Lab Pr oject Number: E 4038: 1026W: 1026W - 1. Unpublished study prepared by Research for Hire. 855 p. 46158501 Shepler, K. (2003) Aerobic Soil Metabolism of (Carbon 14) Fenpyroximate. Project Number: 1038W.

Unpublished study prepared by PTRL West, Inc. 160 p. 47521401 Hiler, T. (2008) Soil Adsorption/Desorption of M - 8 and M - 11 by the Batch Equilibrium Method. Project

Number: 1705W, 1705W/1. Unpublished study prepared by PTRL West, Inc. 269 p. 47521406 Volkl, D. (2001) (Carbon - 14) Fenpyroximate (NNI - 850) [Pyraz ole - labelled] Degradation and

Metabolism in Aquatic Systems. Project Number: E/4027/SUPP/1, 7L365. Unpublished study prepared by RCC Ltd. 134 p. 48381102 Thomas, S.; Kendall, T.; Krueger, H. (2010) Fenpyroximate: A Bioconcentration Test with the Bluegill

(Lepomis macrochirus): Final Report. Project Number: 397A/140. Unpublished study prepared by Wildlife International, Ltd. 93 p.20

**Appendix A**  **. Chemical Names and**  **Structures of Fenpyroximate**  **and Its Transformation Products**  **Table A.**  **1. Fenpyroximate**  **and Its Environmental Transformation Products**  **Code Name/ S**  **ynonym Chemical N**  **am e**  **Chemical S tructure**  **PARENT Fenpyroximate**  **(E -**  **isomer) IUPAC:**  tert - butyl (E) - α - (1,3 - dimethyl - 5 -phenoxypyrazol 4 - yl methyleneaminooxy) -p - toluate **CAS:** 1,1 - dimethylethyl 4 - [[[( E ) - [(1,3 - dimethyl - 5 - phenoxy - 1 H -py

razol - 4 - yl)methylene]amino]oxy]methyl]benzoate **CAS No.:** 134098 - 61 - 6 **Form ula:**  C 24 H 27N 3 O 4 **MW:** 421.50 g/mol **MAJOR TRANSFORMATION PRODUCTS**  **M -**  **1 (Z**  **- isomer)**  tert- butyl (Z) - 4 - [(1,3 - dimethyl - 5 -phenoxypyrazol - 4 -

yl)methylene - aminooxymethyl] - benzoate **Form ula:**  C 24 H 27N 3 O 4 **MW:** 421.50 g/mol21

**Code Name/ S**  **ynonym Chemical N**  **am e**  **Chemical S tructure**  **M -**  **3** ( E ) - 4 - [(1,3 - dimethyl - 5 -phenoxypyrazol - 4 - yl)methylene aminooxy - methyl] - benzoic acid O H O C H 2 O H C H 3

N

C H 3 O N N

**M -**  **6** 1,3 - dimethyl - 5 -phenoxypyrazole - 4 - carbaldehyde22

**Code Name/ S**  **ynonym Chemical N**  **am e**  **Chemical S tructure**  **M -**  **8** 1,3 - dimethyl - 5 -phenoxypyrazole - 4 - carboxylic acid

**M -**  **11** 1,3 - dimethyl - 5 -phenoxypyrazole - 4 - carbonitrile

**M -**  **16** 4 - hydroxymethylbenzoic acid

**Carbon dioxide** Carbon dioxide

**Form ula:**  CO 2 **MW:** 44.1 g/mol 

### O O23

**Figure A.**  **1. Environmental Transformation Route of Fenpyroximate (MRID 45187901, p 52)**  **.**24

**Appendix B .**  **Model Input/Output Files** 

Fen py rox im

ate_ 1-10 -12. fi r Fenpy rox im ate 1-11-12. sc i **Input/ Output Data for Individual Simulations**  **FIRST Input**

**/Output File** RUN No. 1 FOR Fenpyroximate ON Ornamental * INPUT VALUES *

-------------------------------------------------------------------- RATE (#/AC) No.APPS & SOIL SOLUBIL APPL TYPE %CROPPED INCORP ONE(MULT) INTERVAL Koc (PPM ) (%DRIFT) AREA (IN)

-------------------------------------- ------------------------------ 0.343( 0.661) 2 6 649.0 25.0 AERIAL(16.0) 87.0 0.0 FIELD AND RESERVOIR HALFLIFE VALUES (DAYS)

-------------------------------------------------------------------- METABOLIC DAYS UNTIL HYDROLYSIS PHOTOLYSIS METABOLIC COMBINED (FIELD) RAIN/RUNOFF (RESERVOIR) (RES. - EFF) (RESER.) (RESER.)

-------------------------------------------------------------------- 56.00 2 0.00 0.98 - 120.90 51.00 35.87 UNTREATED WATER CONC (MICROGRAMS/LITER (PPB)) Ver 1.1.1 MAR 26, 2008

-------------------------------------------------------------------- PEAK DAY (ACUTE) ANNUAL AVERAGE (CHRONIC) CONCENTRATION CONCENTRATION

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

29.355 1.909 RUN No. 2 FOR Fenpyroximate ON Ornamental * INPUT VALUES *

---------------------------------------------- ---------------------- RATE (#/AC) No.APPS & SOIL SOLUBIL APPL TYPE %CROPPED INCORP ONE(MULT) INTERVAL Koc (PPB ) (%DRIFT) AREA (IN)

-------------------------------------------------------------------- 0.343( 0.661) 2 6 34000.0 26.0 AERIAL(16.0) 87.0 0.0 FIELD AND RESERVOIR HALFLIFE VALUES (DAYS)

-------------------------------------------------------------------- METABOLIC DAYS UNTIL HYDROLYSIS PHOTOLYSIS METABOLIC COMBINED (FIELD) RAIN/RUNOFF (RESERVOIR) (RES. - EFF) (RESER.) (RESER.)

-------------------------------------------------------------------- 56.00 2 N/A 0.98 - 120.90 51.00 35.87 UNTREATED WATER CONC (MICROGRAMS/LITER (PPB)) Ver 1.1.1 MAR 26, 2008

-------------------------------------------------------------------- PEAK DAY (ACUTE) ANNUAL AVERAGE (CHRONIC) CONCENTRATION CONCENTRATION

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

10.756 0.37525

**SCI -**  **GROW Input/Output File** SciGrow version 2.3 chemical:Fenpyroximate time is 1/11/2012 10:27:46

------------------------------------------------------------------------ Application Number of Total Use Koc Soil Aerobic rate (lb/acre) applications (lb/acre/yr) (ml/g) metabolism (days)

------------------------------------- ----------------------------------- 0.343 2.0 0.686 7.55E+03 44.0

------------------------------------------------------------------------ groundwater screening cond (ppb) = 5.17E - 03 ****************************** ****************************************** SciGrow version 2.3 chemical:Fenpyroximate time is 1/11/2012 10:28:35

------------------------------------------------------------------------ Application Number of Total Use Koc Soil Aerobic rate (lb/acre) applications (lb/acre/yr) (ml/g) metabolism (days)

------------------------------------------------------------------------ 0.343 2.0 0.686 1.24E+02 44.0

-------------------------------- ---------------------------------------- groundwater screening cond (ppb) = 2.69E - 01 ************************************************************************26

**Appendix C .**  **Provisional Cranberry Model Equations** The Provisional Cranberry Model is a refinement of the Tier I Rice Model v1.0 (Equation s 1 and 2 ) , which is a simple equilibrium partitioning equation that calculates a single, screening - level concentration in rice paddy water and released tailwater based on a compound’s applic ation rate and soil mobility . **Equation s**  **1 -** **2 : Tier I Rice Model v1**  **.0 (USEPA, 2007b).** 

#   d b sed sed w ai w 

### K

d d m C 

 3 2 0 

### 10

' 10

 

###    (1) and, if appropriate:

OC d 

### K K 01 . 0  (2) where, C w0 = initial water concentration [μg/L ] m ai ' = mass applied per unit area [kg/ha] Kd = water - sediment partitioning coefficient [L/kg] KOC = organic carbon partitioning coefficient [L/kg] dw = water column depth = 0.10 m d sed = sediment depth = 0.01 m θ sed = porosity

of sediment = 0.509 ρ b = bulk density

of sediment = 1300 kg/m 3 First, the Tier I Rice Model was provisionally modified (Equation 3 ) to include as inputs degradation rate constants in order to estimate single, screening - level concentration s in paddy water or tailwater at a giv en time after application. **Equation 3 : Provisional Modified Ri** **ce Model (Jones, 2006).**

d kt ai w 

### K

e m C 00013

. 0 00105 . 0 '    (3) where, C w = water concentration [μg/L ] t = interval since last application [ d ] k = upper 90 th percentile degradation rate constant [ 1/d]27

Then, the Provisional Modified Rice Model water column depth was lengthened to a depth that is used to flood cranberry bogs ( i.e. , 12 inches; Cape Cod Cranberry Growers Association, 2001 ). i.e. , dw = water column depth = 0.305 m In order to model degradation prior to the flood at harvest, the application rates for n number of pre - harvest applications were independently degraded over the interim until flooding and then summed (Equation 4). **Equation 4: Degradation in a Dry Bog.** 

# 

 

###   n t

k n ai ai n



### e m m 1 2



### ' ' (4) where, m ai ' = mass per unit area at flood [kg/ha] m ai ' n = mass applied per unit area on the nth application [kg/ha] k2 = upper 90 th percentile degradation rate constant on dry bog [ 1/d ] tn = interval from the nth application to harvest [ d ] n = number of pre - harvest applications These four equations and parameter sets constitute the Provisional Cranberry Model (reorganized below as Equations 4, 5, and 2 plus parameters ).28

**Equations 2,**  **4**

**, and 5 : Provisional Cranberry Model.** 



# 

 

###   n t

k n ai ai n



### e m m 1 2



### ' ' (4) where, m ai ' = mass per unit area at flood [kg/ha] m ai ' n = mass applied per unit area on the nth application [kg/ha] k2 = upper 90 th percentile degradation rate constant on dry bog [1/d] tn = interval from the nth application to harvest [d] n = number of pre - harvest applications followed b y: 

#   d b sed sed w kt

ai w 

### K d d e

m C 

 3 2 

### 10 ' 10



 

###    ( 5 ) and, if appropriate:

OC d 

### K K 01 . 0  (2) where, C w = water concentration [μg/L ] t = interval since flood [d] k = upper 90 th percentile degradation rate constant [1/d] Kd = water - sediment partitioning coefficient [L/kg] KOC = organic carbon partitioning coefficient [L/kg] dw = water column depth = 0.305 m d sed = sediment depth = 0.01 m θ sed = porosity

of sediment = 0.509 ρ b = b ulk density

of sediment = 1300 kg/m 3