###  1

 OFFICE OF CHEMICAL SAFETY AND POLLUTION PREVENTION UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON, D.C. 20460



### PC Code: 018986 DP Barcode: D421261 Date: September 30, 2014 MEMORANDUM

SUBJECT : Drinking Water Exposure Assessment in Support of the Section 3 New Chemical Registration for the Proposed Use of Bicyclopyrone on Corn

TO: George Kramer, Residue Chemist Kelly Lowe, Risk Assessor Charles (Billy) Smith, Branch Chief Risk Assessment Branch I Health Effects Division (7509P) and Grant Rowland, Risk Manager Reviewer Kathryn Montague, Product Manager Herbicide Branch Registration Division (7505P)

FROM: Cheryl Sutton, Ph.D., Environmental Scientist Environmental Risk Branch IV Environmental Fate and Effects Division (7507P)

REVIEWED Jim Carleton, Ph.D., Senior Scientist BY: Environmental Risk Branch IV Environmental Fate and Effects Division (7507P)

APPROVED Sarah Winfield, Acting Branch Chief BY: Environmental Risk Branch IV Environmental Fate and Effects Division (7507P)

EXECUTIVE SUMMARY
A screening-level drinking water assessment (DWA) for bicyclopyrone [4-hydroxy-3-[[2-[(2- methoxyethoxy)methyl]-6-(trifluoromethyl)-3-pyridinyl]carbonyl]bicyclo[3.2.1]oct-3-en-2-one; CAS # 352010-68-5; PC Code 018986) was conducted in support of the Section 3 new chemical registration. Bicyclopyrone is a selective herbicide of the HPPD-inhibitor class (HydroxyPhenylPyruvate Dioxygenase), and is in the subclass of the triketone chemistry (see Table A1 in Appendix A for chemical structure). Bicyclopyrone inhibits the enzy me HPPD, a catalyst in the chlorophyll biosynthesis pathway. The mode of action of bicyclopyrone is shared with multiple other active ingredients, such as mesotrione, isoxaflutole, topramezone, tembotrione, pyrasulfatole. The proposed single use in the U.S. is Digitally signed by Sutton, Cheryl DN: cn=Sutton, Cheryl, email=sutton.cheryl@epa.gov Date: 2014.10.01 09:39:19 -04'00'

Digitally signed by Winfield, Sarah DN: cn=Winfield, Sarah, email=Winfield.Sarah@epa.gov Date: 2014.10.01 12:03:28 -04'00' Digitally signed by Jim Carleton DN: cn=Jim Carleton, o=EPA/OPP, ou=EFED/ERBIV, email=carleton.jim@epa.gov, c=US Date: 2014.10.01 12:07:10 -04'00'

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 on corn, at a maximum annual application rate of 0.045 lb a.i./A (50g/ha). Bicyclopyrone is also undergoing new chemical registrations in Canada (corn use) and Australia (sugarcane use).

The Surface Water Concentration Calculator (SWCC) computer model was used to generate surface water Estimated Drinking Water Concentrations (EDWCs) for use in the human health dietary risk assessment, while the Pesticide Root Zone Model for Groundwater (PRZM-GW) and Screening Concentration in Ground Water (SCI-GROW) models were used to generate groundwater EDWCs. The Residues of Concern Knowledgebase Subcommittee (ROCKS) identified the residues of concern (ROC) for bicyclopyrone from exposure through drinking water ( Ref. 7 ). The ROC were determined to be parent bicyclopyrone only. Chemical structures for the parent and six degradates are provided in Appendix A

. The maximum acute, chronic, and cancer surface water EDWCs associated with bicyclopyrone use on

corn were 2.87, 0.857, and 0.388 μ g/L , respectively. Selected SWCC results files are presented in Appendix B

. For groundwater sources of drinking water, the maximum acute, chronic and cancer EDWCs of bicyclopyrone in shallow groundwater from PRZM-GW were 3.76, 3.23 and 1.64 μ g/L , respectively. These values, which represent 30 years of use at the maximum label rate for use on corn, are recommended for use in the human health risk assessment. While there were higher values associated with another scenario (Florida citrus) and with a longer simulation period (100 years, WI corn), the recommended values are representative of the pr oposed use on corn and correspond to an area ( “ DelMarVa ” – DE, MD, VA areas) in which corn is grown in the U.S. The maximum acute and cancer groundwater EDWCs from SCI-GROW were 1.32 and 1.32 μ g/L. PRZM-GW and SCI-GROW results files are provided in Appendix B

. Maximum EDWCs for bicyclopyrone residues in surface water and groundwater are presented in Table 1 ; bolded values are recommended for use in the human health dietary assessment. Complete modeling results are presented in Tables 8 and 9

. Table 1. Maximum EDWCs for bicyclopyrone use on corn.

DRINKING

WATER SOURCE (MODEL USED) USE (rate modeled) MAXIMUM ESTIMATED DRINKING WATER CONCENTRATION (EDWC)

Acute ( μ g/L ) Chronic ( μ g/L) Cancer ( μ g/L)

Surface water (SWCC; ND corn scenario) Corn 0.045 lbs a.i./A x 1 (0.05 kg/ha) 2.87 0.857 0.388

Groundwater (PRZM -GW) Corn 0.045 lbs a.i./A x 1 (0.05 kg/ha) 3.76 1 3.23 1.64

Groundwater (SCIGROW) Corn 0.045 lbs a.i./A x 1 (0.05 kg/ha) 1.32 1.32 1.32

1 Values in bold are recommended for use in the human health risk assessment.



### This assessment is based on available environmental fate data. There are no significant data gaps in the environmental fate database. There are no known mon itoring data available for bicyclopyrone in surface water. Maximum residues of parent in groundwater well s at sites in Germany, Hungary, France, and Italy in PGW studies were 1.4 μ g/L, 0.24 μ g/L, 0.11 μ g/L, and 0.34 μ g/L respectively. Maximum residues of

###  3

 the transformation product SYN503780 were 0.11 μ g/L, <LOQ (0.01 μ g/L), 0.03 μ g/L, and 0.17 μ g/L, respectively.

PROBLEM FORMULATION

This is a screening-level drinking water assessment (DWA) that uses modeling to estimate surface water and groundwater concentrations of pesticides in drinking water source water (pre-treatment), resulting from pesticide use on sites that are expected to be vulnerable to runoff and/or leaching. Screening-level DWAs are designed to eliminate the need for further scrutiny of chemicals with low potential for posing drinking water concerns.

ANALYSIS

Use Characterization

Bicyclopyrone is a selective herbicide of the HPPD-inhibitor class (HydroxyPhenylPyruvate Dioxygenase), and is in the subclass of the tri-ketone chemistry. It inhibits the enzyme HPPD, a catalyst in the chlorophyll biosynthesis pathway. Bicyclopyrone ’s mode of action is shared with multiple other active ingredients, such as mesotrione, isoxaflutole, topramezone, tembotrione, pyrasulfatole.

Bicyclopyrone is a new chemical proposed for use in controlling broad leaf weeds and annual grasses in corn in the U.S., at the maximum annual application rate of 0.045 lb a.i./A (50 g/ha). It is to be applied from pre-emergence through to early post-emergence using standard spraying equipment. Based on label instructions, bicyclopyrone is generally to be appl ied once per season; however, a split application preemergent and early post-emergent that equates to the maximum recommended application rate/year (with a 14-day re-application interval) may be used for corn grown for grain, seed or silage.

Bicyclopyrone will be contained in one of two proposed products, a soluble concentrate (SC; 18.1% a.i.; SYN-A16003 Herbicide; EPA Reg. No. 100-RUAA), and a Restricted Use product (RUP) consisting of a mixed formulation of a capsule suspension and su spension concentrate (CS and SC; 0.65% a.i.; SYNA19707 Herbicide; EPA Reg. No. 100-RUAL). In the RUP, bicyclopyrone will be present along with the other active ingredients mesotrione, atrazine, and S-me tolachlor. The Canadian registration is for both products, while the Australian registration is for the SC only.

Table 2. Summary of use information for the bicyclopyrone proposed use on corn.

Use Max. Single Applic . Rate

(lbs a.i./A) Max. Seasonal Applic . Rate (lbs a.i./A) Seasonal Max. # of App. Min. App. Interval (d) EPA Reg. No.

Corn (field corn, seed corn, silage corn, yellow popcorn

and sweet corn) 2 0.045 0.045 2 1 14 100- RUAA (SYN- A16003)

Corn (field corn, seed corn, silage corn, yellow popcorn and sweet corn ) 0.045 3 0.045 3 2 Not stated, but 2 nd applic. must

be postemergence. 100- RUAL (SYN- A19707; Restricted Use product)

1 The typical use will be once per year (as modeled in this assessment), but the label allows for a split application up to the m aximum annual application for corn grown for grain, seed or silage.
2 Applications to sweet corn and yellow popcorn must be pre-emergent only.
3 Single and seasonal rate for this product reduce to 0.0375 lb a.i./A for soils with an organic matter content of <3.5%.

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 Environmental Fate and Transport Characterization

Bicyclopyrone is a relatively soluble, nonvolatile compound that is stable to hydrolysis across all tested pH levels ( i.e ., pH 4-9; MRID 47841919). With a pKa of 3.06, it will exist predominantly as an anion at environmental pHs in U.S. soils. Based on this as well as on submitted soil mobility data, bicyclopyrone will be very highly mobile in soil (MRIDs 47842055, 47842056, 47842057, 47842059). Bicyclopyrone photodegrades on soil, with half-lives ranging from 4 to 13 days (mean of 7.6; n=3; MRID 47842029). It ranges from slightly persistent to persistent in aerobic soil, metabolizing to multiple organic transformation products and carbon dioxide. In 12 domestic and European soils studied, aerobic soil metabolism half-lives ranged from 20 to 350 days (mean of 165 days), indicating a wide variation in persistence across soils (MRIDs 47842026, 47842033, 47842034). In four Brazilian soils, all of which were acidic (pH range of 3.5-5.9), the half-life ranged from 82 to 434 days (mean of 243; MRID 47842035). It is stable in anaerobic soil and anaerobic aquatic systems (MRIDs 47842027, 47842073, 47842074), and is relatively stable in aerobic aquatic systems, with half-lives of 393-681 days (mean of 550; n=4) in the latter (MRIDs 47842073, 47842074). Although it photodegrades relatively slowly in water at most pH levels, with respective half-lives of 11 and 50 days at pH 5 and 7, and 74.8 days in natural water (MRID 47841921), and is relatively stable in aerobic aquatic systems, bicyclopyrone degraded with total system half-lives of 7.4 and 7.5 days in a non-guideline aerobic aquatic metabolism study (with water phase pH values of 7.5 and 7.9) that was irradiated during the incubation (MRID 47842075). However, the significance of this result is unclear, and there were multiple issues with the study that resulted in a classification of “reliable with restrictions.”

Three of the transformation products of bicyclopyrone are very highly mobile in soil. The major transformation product CSCC163768 has K FOC 

### s of 2.8 and 3.4 L/kg in two soils studied (MRID 47842062). Adsorption coefficients could not be quantitatively determined for the major transformation product SYN503780 and the minor transformation product CSAA806573 due to lack of adsorption (MRIDs 47842060, 47842061). The major transformation product CSCD656832 was moderately mobile in one soil and slightly mobile in three soils, with K FOC 

### s of 247, 1340, 5179, 6180 L/kg (MRID 47842155). Structures and maximum concentrations by study for these and other transformation products are presented in Appendix A

. In terrestrial field dissipation studies, bicyclopyrone was non-persistent, with dissipation half-lives of 1.7- 4.4 days in bareground plot studies conducted at three sites in the U.S. (MRIDs 47842038, 47842039, 47842040). The application rate (0.196 lb a.i./A) used in the U.S. studies was over four times the currently proposed application rate for corn use. Ni ne field studies conducted in Europe and one field study conducted in Australia were also submitted. Acro ss all sites, the dissipat ion half-life was generally five weeks or less (see footnotes, Table 4 ).

In the U.S. terrestrial field dissipation studies, limited leaching of bicyclopyrone and its transformation products was observed ( Table 4 ). Thus, while the parent was rapidly dissipated from the surface soil based on the dissipation half-lives, it was unclear what the predominant routes of dissipation were in each study. It is noted that the major soil photolysis transformation product, SYN503780, was detected at all three sites. The registrant has submitted a non-guideline study (not formally reviewed) suggesting that parent compound transported below the surface may be wicked upward through evaporative transport flux in the soil and subsequently photodegraded on the surface soil. However, in that study, the correlation between half-lives and total irradiance is poor (with and without accounting for water input during thefirst week), and it is noted that the maximum concentration for SYN503780 was observed at 1 day posttreatment in two of the three U.S. field studies. Additionally, the lack of detections of the parent

###  5

 compound or the very highly mobile degradate CSCC163768 at depths greater than 0-15 cm throughout the 536- to 546-day studies may indicate that condi tions may not have been conducive to leaching.

Bicyclopyrone may move to groundwater via leaching, and may move to surface water bodies via spray drift and runoff of dissolved or (to a lesser extent) sorbed residues. In aerobic soil metabolism studiesconducted on two of the transformation products (rather than on parent), each was found to be nonpersistent in aerobic soil, with half-lives of 4.7-7.1 days for SYN503780 and <1 day for CSAA806573 (MRIDs 47843036, 47843037). Laboratory metabolism and field studies also showed in general that persistence in the environment was not an expected issue for these transformation products. However, in prospective groundwater studies conducted in Europe following parent bicyclopyrone application, SYN503780 was detected in wells at sampling inte rvals up to 3 years after application (MRIDs 47842066, 47842067, 47842068, 47842069). A more complete discussion of the submitted prospective groundwater studies is included in a later section of this document.

Based on its hydrophilicity (Log K ow 

### of -1.2 at pH 7), bicyclopyrone is not expected to bioaccumulate in aquatic and terrestrial organisms. Table 3 summarizes the physical/chemical properties of bicyclopyrone as reported by the registrant, and Table 4 contains the submitted environmental fate data for the pesticide

. Table 3. Registrant-submitted physical/chemical properties of bicyclopyrone.

Property Results Molecular mass (molecular formula) 399.36 g/mole (C 19 H 20 F 3 NO 5 ) Physical State (pure active substance) White Powder Melting Point (pure active substance) 65.3°C Relative Density (pure active substance) 1.503 g/cm 3 at 20.5°C Aqueous Solubility (at 25 q C) Pure water: 1.2 g/l (a pH of about 3 was recorded) Aqueous sol.: 38 g/L at pH 4.9 Aqueous sol.: 119 g/L at pH 7.2 Aqueous sol.: 119 g/L at pH 9.2 Solubility in various solvents at 25 q C Acetone > 500 g/L Dichloromethane > 500 g/L Ethyl acetate > 500 g/L Hexane 8.9 g/L Methanol > 500 g/L Octanol 91 g/L Toluene > 500 g/L Vapour Pressure at 20 q C < 5 · 10 -6 Pa (pure) Henry’s Law Constant at 25 q C < 1.7

. 10 -6 Pa m3 / mol (pure water; pH ~3)
< 5.3

. 10 -8 Pa m3 / mol (pH 4.9)
< 1.7

. 10 -8 Pa m3 / mol (pH 7.2)
< 1.7

. 10 -8 Pa m3 / mol (pH 9.2)
Octanol/Water Partition Coefficient at 25°C (Log K ow ) At pH 5 log K ow = 0.25 At pH 7 log K ow = -1.2 At pH 9 log K ow = -1.9 Acid Dissociation Constant (pK a ) at 20 q C 3.06

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 Table 4. Environmental fate parameters of bicyclopyrone.
Parameter Value Source
Persistence Hydrolysis half-life (50 q C) Stable at pH 4, 5, 7, 9 MRID 47841919 Aqueous photolysis half-life (25 q C) 11.1 days @ pH 5 50.1 days @ pH7 74.8 days in natural water @ pH 7.3 MRID 47841921

Soil photolysis half-life (20 q C) 4.4, 5.2, 13.3 days MRID 47842029 Aerobic soil metabolism half-life (20°C) 19.8* days (same soil as in study below) MRID 47842026 350, 157, 331, 110, 335, 141, 59.1 days MRID 47842033 53.5, 21.8*(same soil as in study above), 266, 89, 68.4 days MRID 47842034
307, 81.9, 434, 148 days (Brazilian soils; values will not be used in this assessment) MRID 47842035

Not parent ; for metabolite SYN503780 : 4.7, 5.2, 7.1 days MRID 47843036

Not parent ; for metabolite CSAA806573 : <1 day (three soils) MRID 47843037

Anaerobic soil metabolism half-life (20 q C) Stable (half-life not calculated; no degradation during anaerobic phase) MRID 47842027

Aerobic aquatic metabolism half-life (20 q C) 681, 393 days (2 systems) MRID 47842073 661, 466 days (2 systems) MRID 47842074 *NON-GUIDELINE* Aerobic aquatic metabolism with irradiation (metabolism + photodegradation) half-life (20 q C) 7.4, 7.5 days (2 systems) MRID 47842075

Anaerobic aquatic metabolism half-life (20 q C) 1423, 6244 (stable; 2 systems) MRID 47842073 1159, 2077 (stable; 2 systems) MRID 47842074 Mobility Freundlich soil-water partition coefficients (K F ); Freundlich organic carbon

- normalized coefficients (K FOC ) Parent Bicyclopyrone K F : 0.24, 0.83, 0.37, 0.45, 1.39, 0.22, 0.35 L/kg K FOC : 39, 35, 31, 11, 32, 28, 7 L/kg MRID 47842055

Parent Bicyclopyrone K F : 1.34, 0.25, 0.20, 0.14, 1.39 L/kg K FOC : 46, 18, 10, 14, 87 L/kg MRID 47842056

Parent Bicyclopyrone

K F : 0.32, 1.74 L/kg K FOC : 29, 103 L/kg MRID 47842057

Parent Bicyclopyrone K F : 0.11, 0.48, 0.29, 0.13, 0.91 L/kg K FOC : 7, 24, 59, 11, 61 L/kg MRID 47842059

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 Parameter Value Source Parent Bicyclopyrone (Brazilian soils) K F : 1.1, 6.3, 2.2, 26.6 L/kg K FOC : 46, 352, 241, 264 L/kg MRID 47842058

Degradate CSCC163768 K F : 0.03, 0.08 L/kg K FOC : 2.8, 3.4 L/kg

Values could not be determined in two soils due to lack of adsorption. MRID 47842062

Degradate SYN503780 Values could not be determined due to lack of adsorption in all 4 soils. MRID 47842060

Degradate CSAA806573 V alues could not be determined due to lack of adsorption in all 4 soils. MRID 47842061

Degradate CSCD656832 K F : 5.2, 38.9, 51.8, 98.9 L/kg K FOC : 247, 1340, 5179, 6180 L/kg MRID 47842155

Field Dissipation Terrestrial field dissipatio n half-life (bare soil; simulated corn use conditions ) A 4.4 days GA 5.0 days IA 1.7 days NE MRIDs 47842038 47842039 47842040
* The same soil was used in two studies. To prevent double-counting when determining the input values for modeling, the mean of these two (i.e., 20.8 days) will be used to represen t this soil rather than the two individual half-lives. A Reported in the table only for fully reliable, domestic studies. In eight of the reviewed TFD studies (not all foreign studies were reviewed) conducted in Europe, half-lives were determined to be 3.52, 5.9, 10.6, 20.3, 31.5, 36.0, 24.6, and 3.6 days. 

### Microbial degradation in aerobic soil and photodegradation in soil are likely to be the main environmental fate pathways by which the compound transforms.

Major transformation products of bicyclopyrone include:

x CSCC163768 6-(trifluoromethyl)pyridine-2,3-dicarboxylic acid

x SYN503780 (or CSAA794148) 2-(2-methoxy-ethoxymethyl)-6-trifluoromethyl-nicotinic acid

x CSCD656832 3-hydroxy-6-(trifluoromethyl)pyridine-2-carboxylic acid

x CSCD642512 2-[[3-(2,4-dioxobicyclo[3.2.1]octane-3-carbonyl)-6-(trifluoromethyl)-2- pyridyl]methoxy]acetic acid

x CSAA589691 (1S,3R)-cyclopentane-1,3-dicarboxylic acid



### x carbon dioxide.

Minor transformation products of bicyclopyrone include:

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 x CSAA806573 2-hydroxymethyl-6-trifluoromethyl-nicotinic acid

x CSAA915194 4-hydroxy-3-[2-(2-hydroxy-ethoxym ethyl)-6-trifluoromethyl-pyridine-3- carbonyl]-bicyclo[3.2.1]oct-3-en-2-one.

The transformation product detected only in a single non-guideline study (aerobic aquatic metabolism conducted with irradiation) was:

x CSAA456156 6-trifluoro-methyl-pyridine-3-carboxylic acid.

Chemical structures, physical/chemical properties, and a summary of maximum and final detections of the degradates in the fate studies are provided in Appendix A

. Drinking Water Exposure Modeling

Models

Using EFED’s standard suite of models, surface water and groundwater EDWCs were generated for bicyclopyrone for the proposed use on corn. The Surface Water Concentration Calculator (SWCC, v 1.106, May, 2014) is used to generate EDWCs that may occur in surface water used as drinking water. The SWCC simulates pesticide transformation on and r unoff from an agricultural field (in addition to loadings from spray drift), following applications to crops. The model then simulates resulting concentrations in an adjacent surface water body. Standard assumptions for drinking water assessment are a surface water watershed of 172.8 ha that drains into a drinking water “ index ” reservoir of 5.26 ha surface area, and average depth 2.74 m. A more de tailed description of the index reservoir and its watershed can be found in Ref. 6 . A percent cropped area (PCA) adjustment factor of 0.61 for corn was used in the modeling of bicyclopyrone ( Ref. 1 ). Groundwater EDWCs for bicyclopyrone were derived using the PRZM-GW model (Pesticide Root Zone Model for Groundwater, version 1.0, August 31, 2012), with the GW-GUI (Graphical User Interface, version 1.0, August 31, 2012). PRZM-GW is a one-dimensional leaching model that estimates the concentrations of pesticides in groundwater. It accounts for pesticide fate in the crop root zone by simulating pesticide transport and degradation through the soil profile after a pesticide is applied to an agricultural field. PRZM-GW permits the assessment of multiple years of pesticide application (up to 100 years) on a single site. Six standard scenarios, each representing a different region known to be vulnerable to groundwater contamination, are available for use with PRZM-GW for risk assessment purposes. In PRZM-GW simulations, each of these standard scenarios was used. PRZM-GW output represents pesticide concentrations in vulnerable groundwater located directly beneath an agricultural field, following many years of pesticide application ( Ref. 2 and 3 ). EDWCs in groundwater were also estimated using EFED’s groundwater model SCI-GROW (Screening Concentration in Ground Water, version 2.3; 8/8/2003). SCI-GROW is a regression model used as a screening tool to estimate potential pesticide concentr ations in vulnerable groundwater that might be used as drinking water. SCI-GROW was developed by fitting a linear model to groundwater concentrations with the Relative Index of Leaching Potential (RILP) as the independent variable. Groundwater concentrations were taken from 90-day average high concentrations from Prospective Ground Water monitoring studies; the RILP is a function of aerobic soil metabolism and the soil-water partition coefficient. The output of SCI-GROW represents co ncentrations that might be expected to occur in shallow unconfined aquifers under sandy soils, which is representative of the groundwater most vulnerable to pesticide contamination likely to serve as a drinking water source ( Ref. 4 ).

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 Modeling Approach and Input Parameters

Screening-level modeling was conducted to gene rate EDWCs in surface water and groundwater of bicyclopyrone following a 7-day pre-emergent application on corn. Surface water modeling was conducted using SWCC with an application rate of 0.045 lb a.i./A, applied in a single ground spray application. Physical/chemical properties and environm ental fate source data (from submitted studies) are presented in Tables 3 and 4 . Input fate parameters used in surface water modeling with SWCC are presented in Table 5. Scenarios modeled with SWCC are indicated in Table 6 . Bareground applications were modeled with the soil incorporation depth set to 0 cm.

Input parameter values used for groundwater mode ling with SCI-GROW and PRZM-GW are presented in Tables 7 and 8 . Because temperature is important in groundwater modeling, the half-lives derived from aerobic soil metabolism studies conducted at 20 ° C were adjusted (Ref. 3) to reflect the estimated rate of aerobic soil metabolism at 25 ° C, the temperature simulated in the model. Groundwater modeling using PRZM-GW was conducted using a normal 30-yr simulation with all six available scenarios. For the Wisconsin sands/corn scenario, an extended simulation (100-yr) was also used because breakthrough to the water table was not achieved during the 30-yr simulation.

Table 5. Input values for the SWCC model for bicyclopyrone 1



### . Input Parameter Value Source/comment
Molecular weight (g/mol) 399.36 g/mol Registrant-submitted phys/chem property values.
Vapor pressure ( Torr @ 25 oC) 3.75 x 10 -8 Registrant-submitted phys/chem property values (converted from 5
· 10 -6 Pa). Solubility in water (mg/L @ 20oC; pH 7.2) 119,000 Registrant-submitted phys/chem property values. Henry’s Law Constant ( atmm 3 /mol; pH 7.2) 1.67 x 10 -13 Registrant-submitted phys/chem property values (converted from 1.7

. 10 -8 Pa m3/mol). Hydrolysis half-life (t 1⁄2 in days; pH 7) Stable MRID 47841919
Aqueous Photolysis half-life (t 1⁄2 in days; pH 7) 50.1 MRID 47841921

Aerobic Soil metabolism half-life (t 1⁄2 in days) 213.2 MRIDs 47842026, 47842033, 47842034 Represents the 90 percent upper confidence limit on the mean of 12 half- lives (mean = 165.07, SD = 122.14) Anaerobic aquatic metabolism half-life (t 1⁄2 in days) stable MRIDs 47842073, 47842074

Aerobic Aquatic metabolism half -life (t 1⁄2 in days) 667.2 MRIDs 47842073, 47842074 Represents the 90 percent confidence limit on the mean of 4 half

- lives (mean = 550.25, SD =

142.81)

Soil partition coefficient K FD (mL/g oc ) 0.59 MRIDs 47842055, 47842056, 47842057, 47842059 Mean K d (mean of 19 K d s; ionic compound; adsorption not correlated with K oc )

1 EFED input parameter guidance is located at: http://www.epa.gov/oppefed1/models/water/input_parameter_guidance.htm

###  10

 Table 6. SWCC scenarios and inputs for bicyclopyrone modeling.

Use SWCC Scenario Applic. Rate (lbs a.i./A) Applic. Dates Comments

Corn CA_corn FL_sweetcorn IA_corn IL_Corn IN_Corn KS_Corn MN_Corn MS_corn NC_cornE NC_cornW

ND_corn NE_Corn OH_Corn PA_corn STX_corn TX_corn 0.045 (0.05 kg/Ha) Applied 7 days pre- emergence Single, pre

- emergence application to soil surface by ground spray.



### Table 7. Input values for the SCI-GROW model for bicyclopyrone.

Variable Name Data Value Data Source MRID(s) Comment
Application Rate (lbs. a.i./ A/application) 0.045 Label

̶

Application Frequency 1 Label

̶

Aerobic Soil Metabolism Half -life (days) 125.5 MRIDs 47842026, 47842033, 47842034 Represents the median of 12aerobic soil metabolism halflife values. 1

K FOC (mL/g oc ) 7 MRIDs 47842055, 47842056, 47842057, 47842059 Lowest of 19 values (since there is >three

- fold variation) 1

1 EFED input parameter guidance is located at: http://www.epa.gov/oppefed1/models/water/input_parameter_guidance.htm



### Table 8. Input values for the PRZM-GW model for bicyclopyrone.

Variable Name Data Value Data Source MRID(s) Comment

Application Method Ground spray Label

Application Date 7 days pre-emergence Label Single, pre

- emergence application to soil.

Application Rate (lbs. a.i./acre) [kg/ha] 0.045 [0.05] Label

Application Frequency 1 Label

###  11

 Variable Name Data Value Data Source MRID(s) Comment
Application Interval (days) NA
Hydrolysis Half-life (days; pH 7.2) stable MRID 47841919

Aerobic Soil Metabolism Half -life (days) 151.1 MRIDs 47842026, 47842033, 47842034 Represents the 90% upper confidence limit on the mean of 12 aerobic soil metabolism half

- life values adjusted to 25

° C.

K FD (mL/g) 0.59 MRIDs 47842055, 47842056, 47842057, 47842059 Mean of 19 K FD values (ionic compound; adsorption not correlated with K oc )

1 EFED input parameter guidance: http://www.epa.gov/oppefed1/models/water/przm_gw/wqtt_przm_gw_input_guidance.htm
2 Input value was determined from half-lives adjusted for temperature as described in Ref. 3.


### Modeling Results

Surface water modeling results for bicyclopyrone are presented in Table 9 , with maximum values in bold. Groundwater results for bicyclopyrone are presented in Table 10 , with maximum concentrations in bold. Values from PRZM-GW modeling in Table 10 are recommended for use in the human health dietary assessment, as they are generally higher than the su rface water maximum values. Outputs from the modelrun associated with the maximum values for each model, in addition to results summaries for all PRZMGW scenarios, are provided in Appendix B . Output concentrations for surface water have been adjusted using a PCA adjustment factor of 0.61 representing corn. Output concentrations for groundwater are not adjusted using a PCA, since PCAs represent watershe d-scale dilution effects that cannot be presumed to apply to groundwater.

Table 9. Bicyclopyrone screening level EDWCs for surface water.

Crop Scenario 1-in- 10 year acute ( μ g/L) 1-in- 10 year chronic ( μ g/L) 30 year mean

cancer ( μ g/L)

Corn CA_corn 0.588 0.286 0.153 FL_sweetcorn 1.39 0.235 0.126 IA_corn 0.989 0.360 0.124 IL_Corn 1.20 0.383 0.184 IN_Corn 1.32 0.445 0.164 KS_Corn 2.18 0.570 0.264 MN_Corn 1.29 0.526 0.238 MS_corn 2.87 0.469 0.180 NC_cornE 0.621 0.196 0.095 NC_cornW 0.579 0.152 0.076

ND_corn 0.610 0.395 0.240

###  12

 Crop Scenario 1-in- 10 year acute ( μ g/L) 1-in- 10 year chronic ( μ g/L) 30 year mean

cancer ( μ g/L) NE_Corn 2.71 0.857 0.388 OH_Corn 2.27 0.747 0.218 PA_corn 0.677 0.237 0.106 STX_corn 1.98 0.566 0.247 TX_corn 0.981 0.269 0.116



### Table 10. PRZM-GW and SCI-GROW results based on proposed bicyclopyrone use on corn.

Model Crop Use Modeled 1 Scenario (Tier 1) Highest Daily Value ( μ g/L) Post Breakthrough A verage ( μ g/L) Entire Simulation Mean

Concentration ( μ g/L) Time to Breakthrough ( days) (years)

PRZMGW Corn WI Central Sands/Corn (30 -yr simulation) 1.93 Incomplete (Breakthrough not achieved.) 0.32 Incomplete (Breakthrough not achieved.)

PRZMGW Corn WI Central Sands/Corn ( 100 -yr simulation ) 6.07 5.64 3.89 12,079

PRZMGW Corn DELMARVA Sweet Corn - Evesboro Loamy Sand 3.76 2 3.23 1.64 5,727

PRZMGW Corn Florida Citrus - FL Central Ridge, Polk County/Astatul a sand 5.97 5.19 3.78 3,238

PRZMGW Corn FLORIDA - potato - Jacksonville 2.69 2.52 1.95 2,705

PRZMGW Corn GA - Southern Coastal Plain, Tifton loamy sand - Peanuts 1.87 1.69 1.03 4,900

PRZMGW Corn NC Eastern Coastal Plain - Norfolk loamy sand - Cotton 2.14 1.71 0.536 8,582

SCIGROW Corn NA 1.32 NA NA

−

1 In this context, crop refers to the use modeled in terms of time of application, type of application, and application rates. P RZMGW standard scenarios were developed based on specific crop use areas, so the crop identified for each may differ from the crop use modeled. 2 Values in bold are recommended for use in the human health risk assessment.


### The SCI-GROW and PRZM-GW concentrations repres ent groundwater concentrations that might be expected in shallow, unconfined aquifers under sandy soils. The SWCC modeled concentrations ( μ g/L) represent untreated surface water.

###  13

 Bolded values, from the 30-yr simulation of bicyclopyrone use on corn as modeled using the DELMARVA Sweet Corn - Evesboro Loamy Sand scenario in PRZM-GW, are recommended for use in the human health dietary risk assessment. The simula ted concentrations provided in this assessment are expected to be conservative representations of concentrations in drinking water. While there were higher values associated with another scenario (Flo rida citrus) and with a longer simulation period (100 years; WI corn), the recommended values are represen tative of the proposed use on corn and correspond to an area in which corn is commonly grown in the U.S.

Monitoring Data

Only limited monitoring data are available for bicyclopyrone and its degradates, as bicyclopyrone is a new chemical. There are no surface water monitoring data available. To determine the potential for groundwater contamination, multiple Prospective Groundwater Studies (OCSPP 835.7100) conducted in Europe were submitted to demonstrate the leaching of the compound in the field. The study results are summarized below. A review of the studies indicated that they are reliable, but with restrictions ( i.e
., classified supplemental). All of the (European) studies had deficiencies relative to OCSPP 835.7100 guidance, such as using multiple rather than single applications, not installing wells in clusters, not screening at two depths, placing wells outside the perimeter of the test plot, insufficient water inputs, and not collecting soil samples and soil-pore water samples. None of the studies were conducted in the U.S. Applications were early post-emergence.

(MRID 47842066; Germany) Bicyclopyrone was broadcast applied as an Emulsifiable Concentrate formulation (A15749E/A15749F, containing nominal 150 g a.i./L) at a nominal rate of 0.18 lb a.i./A (equivalent to 200 g a.i./ha) annually from May 2007 to 2011. Residues of bicyclopyrone were measured in all eight studied down-gradient wells. All wells were between 3.37 and 3.93 m deep. Residues above the LOQ (0.01 μ g/L) were first observed (0.04 μ g/L) in wells closer to the point of application at 336-904 days post-treatment, and were observed in all down-gradient wells by 1247 days post-treatment. Residues of bicyclopyrone generally increased in all down -gradient wells throughout the study period, with maximum concentrations in each well ranging from 0.06 to 1.4 μ g/L, and residues still detected at 1478- 1629 days post-treatment. Bicyclopyrone was not detected above the LOQ in up-gradient wells, with the exception of trace residues (0.01-0.02 μ g/L) in one well following a wet summer period, and trace residues (0.02-0.09 μ g/L) in two other wells following a dry spring. The tran sformation product SYN503780 was first detected in various down-gradient wells at 966 days (1 well), 1111 days (1 well), and 1399-1428 days (4 wells) days; residues were not detected above the LOQ in two wells during the study period. Maximum observed SYN503780 concentrations in water from wells B3-B8 were as follows: 0.04-0.11 μ g/L at 1189-1629 days. Residues of SYN503780 generally increased during the study period in one well to a maximum level at 1601-1629 days, and appeared to peak and decline to <LOQ (0.01 μ g/L) in two other wells. A clear pattern of increase or peak and decline was not observed in the other down-gradient wells. Residues of SYN503780 were not detected above the LOQ in any of the six up-gradient wells.

(MRID 47842067; Hungary) Bicyclopyrone was first detected in a shallow, down-gradient well at 0.02 μ g/L at 726 days after the initial application, and was first detected in three other wells at 811-848 days. Bicyclopyrone was detected in one well at a maximum concentration of 0.24 μ g/L at 848 days and declined to <LOQ (0.01 μ g/L) by 1069 days. Bicyclopyrone was detected in two wells at ≤ 0.02 μ g/Land had declined to <LOQ by 1134-1169 days. Bicyclopyrone was not detected above the LOQ (0.01 μ g/L) in the other seven wells studied. The only three monitoring wells with consistent detections of bicyclopyrone at >LOQ were all located down-gradient; however, it was not detected above the LOQ in the pair of wells located directly down-gradient of th e prevailing groundwater flow direction. Residues of the transformation product SYN503780 were not detected above the LOQ (0.01 μ g/L) in any wells.

###  14

 (MRID 47842068; France) Residues of bicyclopyrone were only monitored in four well clusters located down-gradient. Bicyclopyrone was first detected in each of the four shallow down-gradient wells at 306- 951 days post-treatment and was a maximum of 0.07 μ g/L at 740 and 1195 days. Bicyclopyrone was first detected in each of the four down-gradient deep wells at 404-951 days post-treatment, was a maximum of 0.11 μ g/L at 951 days and was ≤ 0.06 μ g/L at 1245 days post -treatment (residues detected in three shallow wells and two deep wells). The transformation product SYN503780 was generally only detected in one down-gradient well cluster, with residues first observed at the LOQ (0.01 μ g/L) in both shallow and deep wells at 404-434 days, and residues detected at a maximum of 0.03 μ g/L at 1043, 1103, and 1131 days in the shallow well. SYN503780 was also detected once each in two shallow wells at the LOQ (0.01 μ g/L; 740 and 951 days), and was detected twice in a deep well (at 951-986 days) at 0.01-0.02 μ g/L.

(MRID 47842069; Italy) Bicyclopyrone was first observed in all six studied down-gradient wells between 188 and 353 days post-treatment. Bicyclopyrone residues were detected in separate wells at maxima of 0.04- 0.34 μ g/L (589 -1053 days). Bicyclopyrone decreased to <LOQ (0.01 μ g/L) by 836-1233 days posttreatment in three wells, and was 0.05- 0.13 μ g/L in the other three studied wells by the end of the study (1254 days). The transformation product SYN503780 was initially detected in three of the down-gradient wells at the LOQ (0.01 μ g/L) at 188- 234 days, and was not detected at ≥ LOQ in the remaining three down-gradient wells until 553-713 days. SYN503780 was detected in two wells at a maximum of 0.02 μ g/L (713-746 days) and declined to <LOQ by 776-868. In two other wells, maximum SYN503780 concentrations were 0.12-0.15 μ g/L (776 days) and declined to <LOQ (0.01 μ g/L) by 953-986 days. In two wells, SYN503780 residues were a maximum at 0.17 μ g/L (807- 868 days) and declined to ≤ 0.03 μ g/L by the end of the study (1254 days).

Drinking Water Treatment Effects

No specific information on the effects of drinking water treatment on the removal of bicyclopyrone or its degradates is currently available. The EDWCs in this assessment are representative of concentrations in drinking water source water (pre-treatment), and are based primarily upon multi-decadal simulated time series of daily concentrations. For surface water, the conceptual model assumes that pesticide reaches surface water via runoff and spray drift, and is then mixed throughout the water column and available to reversibly sorb to benthic sediments. As bicyclopyrone is stable to hydrolysis, the compound is not expected to degrade during the time that elapses between intake and distribution to the consumer tap. Because the chemical’s K FD 

### values indicate high mobility, and it is present mainly as an anion at environmental pHs, treatment methods such as sedimentation, flocculation, and activated carbon filtration, which are designed to remove solids an d/or hydrophobic contaminants, may not remove much of the compound during treatment, and any fraction that might be removed cannot be quantified.

Uncertainties and Data Gaps

This assessment is based upon available environmental fate data. There are no significant data gaps in the environmental fate database submitted by the registra nt. However, there is some uncertainty introduced by a supplemental submitted non-guideline aerobic aquatic metabolism study (with water phase pHs of 7.5 and 7.9) that was irradiated during the incubation (MRID 47842075). In the study, bicyclopyrone dissipated with half-lives of 7.4 and 7.5 days (despite the fact that the compound photodegrades relatively slowly in water at most pH levels, with respective half-lives of 11 and 50 days at pH 5 and 7, and 74.8 days in natural water), and was relatively stable in the submitted guideline aerobic aquatic studies (which are conducted in darkness). However, the significance of this result ( i. e., rapid dissipation in a study that includes irradiation and relative stab ility in a study conducted in darkness) is unclear, and there were multiple issues with the study that resulted in a classification of “reliable with restrictions.”

###  15

 Additionally, the registrant has sought to show that parent compound transported below the soil surface may be wicked upward through evaporative transpor t flux with water in the soil and subsequently photodegraded on the surface soil, resulting in more rapid degradation than would occur in soil through metabolism alone (MRIDs 47842030, 47842170). The registrant has surmised that the rapid dissipation and lack of substantial leaching in the terrestrial field studies is due to this process. However, the correlation between half-lives and total irradiance is poor (with and without accounting for water input during the first week) in that study, and it is noted that the maximum concentration for the soil photolysis transformation product SYN503780 was observed at 1 day post-treatment in two of the three U.S. terrestrial field studies, and was not detected below the 0- to 15-cm depth in those. However, in prospective groundwater studies following parent bicyclopyrone application, SYN503780 was detected in wells at sampling intervals up to 3 years after application.

The drinking water assessment is a screening-level assessment based upon standard models and assumptions. The modeling assessment relies on a ma ximum use pattern (application rate) for corn to reflect surface water and groundwater concentrations, and a national default PCA (0.61) to reflect potential surface water concentrations. To the extent that actual use patterns involve application of less a.i. than the permissible (labeled) maxima or util ize a split application, and location-specific crop acreages represent lower land coverage percentages than the PCA used in this assessment, aquatic concentrations (particularly the acute) in some loca tions could be lower than EDWCs reported herein. Additionally, applications of bicyclopyrone were assumed to occur once every year for 30 years (or longer when required to achieve breakthrough in PRZM -GW). If information were available in the future to indicate that this is not common practice, EDWCs may also be lower than those reported.

It is noted that as a groundwater screening tool, PRZM-GW works to simulate concentrations greater than those observed in the vast majority of drinking water wells. In a non-targeted context, an effective screen provides concentrations that are greater than those observed in monitoring studies. Groundwater EDWCs reported here were modeled with PRZM-GW, which does not take into account photodegradation at the soil surface. With photodegradation on soil half-lives of approximately 4-13 days, it is possible that some degradation will occur on soil in the field via this pathway under normal use conditions, as bicyclopyrone is applied to the soil surface as a pre-emergent. Additionally, PRZM-GW does not consider erosion or runoff of a pesticide, which will also serve to make less available for leaching to groundwater.

References

1. Development and Use of Percent Cropped Area Adjustment Factors in Drinking Water Exposure Assessments (9/9/2010) ( http://www.epa.gov/oppefed1/models/water/pca_adjustment_dwa.html ) 2. PRZM-GW: Guidance for Using PRZM-GW in Drinking Water Exposure Assessments (10/15/ 2012) 3. PRZM-GW: Guidance for Selecting Input Parameters for Modeling Pesticide Concentrations in Groundwater Using the Pesticide Root Zone Model (10/15/ 2012) 4. SCIGROW: Users Manual (11/01/2001, revised 08/23/2002) 5. Guidance for Selecting Input Parameters in Modeling the Environmental Fate and Transport of Pesticides, Version 2.1 (10/22/2009) ( http://www.epa.gov/oppefed1/models/water/input_parameter_guidance.htm ) 6. USEPA. 2010. Development and Use of the Index Reservoir in Drinking Water Exposure Assessments. ( http://www.epa.gov/oppefed1/models /water/index_reservoir_dwa.html ) 7. Bicyclopyrone. Report of the Residues of Concern Knowledgebase Subcommittee (ROCKS). September 2014 Memo from Ideliz Negrón-E ncarnación, ROCKS Alternate Secretary Health

###  16

 Effects Division, to Bicyclopyrone Risk Assessment Team Risk Assessment Branch I, HED. DP Barcode D421264.

Submitted Studies

MRID 47841919. Adam, D., 2008. [Pyridinyl-14C]-labelled NOA449280

– Hydrolysis at four different pH values. Syngenta Ltd., Jealott’s Hill International Research Centre, Bracknell, Berkshire, RG42 6EY, UK. RCC Study Number: B75598. Syngenta Sypos task ID: T013175-05.

MRID 47842075. Adam, D., 2010. NOA449280

– Route and rate of degradation in water/sediment system under artificial sunlight. Syngenta Ltd., Jealott’s Hill International Research Centre, Bracknell, Berkshire, RG42 6EY, UK. Study Number: 115 01 042. Task Number: T002567-08.
MRID 47842055. Brice, A.; Gilbert, J. 2010. NOA449280- Adsorption and Desorption Properties in Seven Soils: Final Report. Project Number: 1'001923/07/0C~ 1983/076/D2149, 1983/076. Unpublished study prepared by Covance Laboratories, Ltd. 144 p.

MRID 47842027. Brice A and J. Gilbert, 2010. NOA449280 - Metabolism and rate of degradation of 14C-pyridinyl and 14C-bicyclooctenone labelled NOA449280 under anaerobic laboratory conditions, in one Soil, at 20°. Syngenta Ltd., Jealott’s Hill International Research Centre, Bracknell, Berkshire, RG42 6EY, UK. Report Number: 1983/070-D2149. Task Number: T013196-05.
MRID 47842066. Finger, N., 2012a. NOA449280 - Leaching behaviour of NOA449280 and its metabolite into groundwater in a field trial

– Lorsch, Germany, 2007- 2012. Syngenta Ltd., Jealott’s Hill International Research Centre, Bracknell, Berkshire, RG42 6EY, UK. Report Number: S07-00066- Interim-1. Task Number: TK0009218.
MRID 47842067. Finger, N., 2012b. NOA449280 - Leaching behaviour of NOA449280 and its metabolite into groundwater in a field trial

– Aba, Hungary. Syngenta Ltd., Jealott’s Hill International Research Centre, Bracknell, Berkshire, RG42 6EY, UK. Report Number: S08-01322-Interim-1. Task Number: TK0009273.
MRID 47842068. Finger, N., 2012c. NOA449280 - Leaching behaviour of NOA449280 and its metabolite into groundwater in a field trial

– Alsace, France. Syngenta Ltd., Jealott’s Hill International Research Centre, Bracknell, Berkshire, RG42 6EY, UK. Report Number: S08-01327-INTERIM-1. Task Number: TK0009274.
MRID 47842073. Gassen M, 2009, NOA449280 - [Pyridinyl-3-14C]-labelled NOA449280 - Metabolism and rate of degradation under aerobic and anaerobic conditions in aquatic systems. Syngenta Ltd., Jealott’s Hill Internat ional Research Centre, Bracknell, Berkshire, RG42 6EY, UK. Study Number: B44425. Syngenta Reference Number: T013193-05.
MRID 47842074. Gassen M, 2010. [Bicyclooctenone-6,7-14C2]-labelled NOA449280

– Metabolism and rate of degradation under aerobic and a naerobic conditions in aquatic systems. Syngenta Ltd., Jealott’s Hill International Research Centre, Bracknell, Berkshire, RG42 6EY, UK. Study Number: B46012. Syngenta Reference Number: T013194-05.
MRID 47842030. Hand, L., C. Nichols and S. Kuet, 2012.Investigation into the factors controlling photolysis and the movement of the active ingredient within soil. Syngenta Ltd., Jealott’s Hill International Research Centre, Bracknell, Berkshire, RG42 6EY, UK. Report Number: PM-08-533. Task Number: T000808-07.

###  17

 MRID 47842026. Lewis C., 2009. NOA449280

– Metabolism and Rate of Degradation of 14 

### CBicyclooctenone Labelled NOA449280 under Aerobic Laboratory Conditions, in One Soil, at 20°C, Covance Laboratories Limited, UK. Report Number: 1983/071-D2149. Unpublished report (Syngenta File No. NOA449280_11046).

MRID 47842026. Lewis, C.; Gilbert, J. 2012. NOA449280- Metabolism and Rate of Degradation of [Carbon 14]Bicyclooctenone Labelled NOA449280 Under Aerobic Laboratory Conditions, in One Soil, at 20 (Degrees Celsius): Final Report. Project Number: T013183/05/0CR, 1983/071/D2149, 1983/071. Unpublished study prepared by Covance Laboratories, Ltd. 83 p.

MRID 47842032. Brice, A.; Heslop, D. 2009. NOA449280 - Rate ofDegradation ofNOA449280 Under Aerobic Laboratory Conditions, in Five Soils, at 20 (Degrees Celsius): Final Report. Project Number: T001436/08/0CR, 1983/089/D2149. Unpublished study prepared by: Covance Laboratories, Ltd .. 117p.

MRID 47842033. Lewis, C.; Gilbert, J. 2009. NOA449280 - Metabolism and Rate of Degradation of [Carbon 14]Pyridine Labelled NOA449280 Under Aerobic Laboratory Conditions, in Seven US Soils, at 20 (Degrees Celsius): Final Report. Project Number: T001922/07/0CR, 1983/075/D2149. Unpublished study prepared by Covance Laboratories, Ltd. 222 p.

MRID 47842034. Lewis, C.; Gilbert, J. 2009. NOA449280- Metabolism and Rate of Degradation of [Carbon 14]Pymine Labelled NOA449280 Under Aerobic Laboratory Conditions, in Five Soils, at 20 (Degrees Celsius): Final Report. Project Number: T013182/05/0CR, 1983/069/D2149. Unpublished study prepared by: Covance Laboratories, Ltd . 188 p.

MRID 47842036. Lewis, C.; Gilbert, J. 2010. NOA449280- Rate of Degradation of [Carbon 14]-Pyridine Labelled SYN503780, a Soil Metabolite, Under Aerobi c Laboratory Conditions, in Three Soils, at 20 (Degrees Celsius). Project Number: T005859/06/0CR, 1983/085/D2149. Unpublished study prepared by: Covance Laboratories, Ltd. 170 p.

MRID 47842037. Dixon, K.; Gilbert, J. 2010. NOA449280- Rate of Degradation of [Carbon 14]- Pyridine Labeled CSAA806573, a Soil Metabolite, Under Aerobic Laboratory Conditions, in Three Soils, at 20 (Degrees Celsius): Final Report. Project Number: T007596/08/0CR, 1983/113/D2149. Unpublished study prepared by Covance Laboratories, Ltd. 117 p.

MRID 47841921. Lewis C. J. And J. Gilbert, 2009 . [14C]NOA449280 - Photodegradation and quantum yield in sterile, aqueous solution. Syngenta Ltd., Jealott’s Hill International Research Centre, Bracknell, Berkshire, RG42 6EY, UK. Report Number: 8215834-D2149, Task Number: TK011883.
MRID 47842028. Lewis, C.J. and J. Gilbert, 2010. [14C]NOA449280 - Photodegradation on Soil Surface. Final Report Amendment 1.Syngenta Ltd., Jealott’s Hill International Research Centre, Bracknell, Berkshire, RG42 6EY, UK. Repo rt Number: 1983/072-D2149, Task Number: T013191-05.
MRID 47842029. Lewis, C.J. and J. Gilbert, 2011. [14C]NOA449280 -Photodegradation on three US soils. Syngenta Ltd., Jealott’s Hill International Research Centre, Brackn ell, Berkshire, RG42 6EY, UK. Report Number: 8215834-D2149, Task Number: TK011883.

MRID 47842060 Lewis, C.; Gilbert, J. 2009. NOA449 280- Adsorption and DesorptionProperties of [Carbon14]SYN503780 in Four Soils: Final Report. Project Number: 1'005863/06/0CR, 1983/086/D2149. Unpublished study prepared by Covance Laboratories, Ltd. 72 p.

###  18

 MRID 47842057 Lowden, P.; Brett, R. 2009. [Carbon 14]-NOA449280- Adsorption and Desorption Properties of Two Soils: Final Report. Project Number: 1'013198/05/0CR, NC/07/003. Unpublished study prepared by Battelle UK Ltd. 85 p.

MRID 47841909. Geoffroy, A., 2007. NOA449280

– Vapour Pressure. Syngenta Crop Protection Münchwilen AG, CH-4333 Müchhwilen, Switzerland. Study Number: L07-002662.
MRID 47841914. Weissenfeld, M., 2009. NOA449280 Determination of the water solubility. Syngenta Crop Protection Münchwilen AG, Breitenloh 5, 4333 Münchwilen, Switzerland. Harlan Laboratories Study B46056.
MRID 47842060. Peranginangin, N., D.P. Simmons, A. Sapiets, C. Nichols, 2012. Refined modelling of NOA449280 using data from targeted higher tier laboratory studies to reflect a conceptual model of dissipation pathways under field conditions. Syngenta Crop Protection, LLC., Greensboro, NC. Report Number: TK0009393.
MRID 47842038. Simmons, D. and A. Newcombe, 2011a. Dissipation of NOA449280 EC Formulation in Bare Soil Plots Under Simulated Field Corn Production Conditions. Syngenta Crop Protection , LLC., Greensboro, NC. Report Number: T004878-06.
MRID 47842039. Simmons, D., B. Jacobson, N. McLean and A. Sapiets, 2011a. Dissipation of NOA449280 EC formulation on bare soil under simulated corn production conditions in Iowa. Syngenta Crop Protection, LLC., Greensboro, NC. Report Number: T004878-06.
MRID 47842040. Simmons, D., B. Jacobson, N. McLean and A. Sapiets, 2011b. Dissipation of NOA449280 EC formulation on bare soil under simulated corn production conditions in Nebraska. Syngenta Crop Protection, LLC., Greensboro, NC. Report Number: T004880-06.
MRID 47842070 S:immns, D.; McLean, N. 2012. NOA449280- Stability of NOA449280 and SYN503780 in Soil Under Freezer Storage Conditions: Final Report. Project Number: T002698/07/ORC

, 11SYN2791REP. Unpublished study prepared by Syngenta Crop Protection LLC and ALS Environmental 141 p.

MRID 47842162. Simmons, D.; McLean, N. 2012. StabilityofCSCC163768, CSCD656832, CSCD642512 and CSAA806573 in Soil Under Freezer Storage Conditions: Final Report. Project Number: T013395/05/0C~ 12SYN3161REP. Unpublished study prepared by Syngenta Crop Protection, LLC and ALS Environmental 267 p.

MRID 47842069



## . Trevisan, M., 2012. NOA449280

– Field leaching behaviour study at site L01 (Orzinuovi-BS) in Italy

– multisite study. Syngenta Ltd., Jealott’s Hill International Research Centre, Bracknell, Berkshire, RG42 6EY, UK. Report Number: CZ/08/019/UCSC/NOAGL1/R1. Task Number: TK002356-07 (TK0009355).
MRID 47842071. Zietz, E., 2012. NOA449280 - Leaching behaviour of NOA449280 and its metabolite SYN503780 into groundwater in a field trial

– Buzet-sur- Tarn, France. Syngenta Ltd., Jealott’s Hill International Research Centre, Bracknell, Berkshire, RG42 6EY, UK. Report Number: IF-08/01121619- INT-1. Task Number: TK002355-07.
MRID 47842123. Zietz, E. 20 12. NOA449280 - Determination of the Storage Stability ofNOA449280 and its Metabolites SYN503780, CSCC163768, CSCD656832, CSCD642512 and CSAA806573 in Groundwater: Final Report. Project Number: TK0009215/0CR, IF/09/01378891. Unpublished

###  19

 study prepared by SGS Institut Fresenius GmbH. 97 p.
MRID 47842117. Brain, R. 2011. NOA449280- Waiver Justification for Fish Bioaccumulation Study. Project Number: TK0089334/0CR Unpublished study prepared by Syngenta Crop Protection, LLC. 5 p
MRID 47841950. Braid, S.; McLean, N. (2009) NOA449280- Residue Analytical Method fur the Determination of NOA449280 and its Metabolites SYN503780, CSCD656832, CSCD642512, CSCC163768 and CSAA806573 in Soil Final Determination by LC-MS/MS. Project Number: 1'000993/08/0CR, GRM030/04A. Unpublished study prepared by Syngenta Jealotts Hill International Research Centre. 144p.

MRID 47841954 Crook, S. (2008) NOA449280- Residue Method for the DeterminationofNOA449280 and Metabolite SYN503780 in Water: Final Determination byLC-MS/MS. Project Number: T010139/040CR, GRM030/01A. Unpublished study prepared by Syngenta Jealotts Hill International Research Centre. 48 p.

MRID 47841955 Morriss, A; Eversfield, S. (2008) NOA449280- Validation of a Method (Draft GRM030.01A) for the DeterminationofNOA449280 and SYN503780 in Drinking, Surfuce and Ground Water. Project Number: 1'013212/05/0CR, CEMR/3547. Unpublished study prepared by CEM Analytical Services, Ltd. 35 p.

MRID 47841956 Zietz, E. (2011) NOA449280- ValidationofanAnalyticalMethod (Draft GRM030.06A) for the DeterminationofNOA449280 and its Metabolites SYN503780, CSCC163768, CSCD656832, CSCD642512 and CSAA806573 in Water. Project Number: TK0009384/0CR, lF/09/01378742. Unpublished study prepared by SGS Institut Fresenius Chemische und Biologische. 123 p.

MRID 47841959. Oppilliart, S. (2008) NOA449280-Validation ofResidue Method AGRIMOA/NOA449280-2 for the DeterminationofNOA449280 in Air: Final Report. Project Number: 1'013551/05/0CR, 1'013551/05/REG. Unpublished stud y prepared by ADME Bioanalyses. 41 p.

MRID 47841949. Hargreaves, S. (2007) NOA449280 - Residue Method fur the Determination ofNOA449280 and Metabolite SYN503780 in Soil: Ana.Jytical Method. Project Number: T013208/05/0CR,GRM/030/02A. Unpublished study prepar ed by Syngenta Jea1otts Hill International Research Centre. 47 p.

MRID 47841950. Braid, S.; McLean, N. (2009) NOA449280 - Residue Ana.Jytical Method fur the Determination of NOA449280 and its Metabolites SYN503780, CSCD656832, CSCD642512, CSCC163768 and CSAA806573 in Soil Final Determination by LC-MS/MS. Project Number: 1'000993/08/0CR, GRM030/04A. Unpublished study prepar ed by Syngenta Jea1otts Hill International Research Centre. 144p.

MRID 47841951. Eversfield, S. (2007) Va1idation of a Method (Draft GRM030.02A) for the Determination of NOA449280 and SYN503780 in Soil Project Number: 1'013392/05/0CR, CEMR/3644. Unpublished study prepared by CEM Ana.Jytical Services, Ltd. 31 p.

MRID 47841952. Hagan, M. (2009) NOA449280 - Valida tion of Draft Method GRM030.04A for the Determination of NOA449280, SYN503780, CSCC163768, CSCD656832, CSCD642512 and CSAA806573 in Soil: Final Report. Project Number: T001384/09, 09SYN256/REP, ALS09SYN01/PRO. Unpublished study prepared by ALS Laboratory Group, Environmental. 109 p.

###  20

 MRID 47841953 Oppilliart, S. (2009) NOA449280 - Validation of Analytical Method GRM030.04A for the Determination of Residues ofNOA449280 and Metabolites SYN503780, CSCD656832, CSCD642512, CSCC163768 and CSAA806573 in Soil Project Number: TK0014608/0CR, TK0014608/REG, S09/02700. Unpublished study prepared by ADME Bioanalyses. 163 p. 21

 Appendix A Table A1. Bicylopyrone and its Env ironmental Transformation Products

Code Name Chemical Name Chemical Structure Study Type MRID(s) Maximum %AR (day) A,B Final %AR (study length or

last interval

detected)

PARENT
NOA449280 Bicyclopyrone

IUPAC: 4-hydroxy-3-[2- (2- methoxy -ethoxymethyl)- 6- trifluoromethyl -pyridine- 3- carbonyl]

- bicyclo[3.2.1]oct-3-

en -2-one CAS: 4-hydroxy-3-[[2- [(2- methoxyethoxy)methyl]

- 6- (trifluoromethyl) -3- pyridinyl]carbonyl]bicyclo[3. 2.1]oct -3-en-2-one

CAS No. 352010-68-5

Formula: C 19 H 20 F 3 NO 5 MW: 399.36 g/mol

SMILES Code: COCCOCc1c(ccc(n1)C(F)(F) F)C(=O)C2=C( C3CCC(C3)C 2=O)O O CF 3 N O OH O OMe Aerobic Soil Metabolism 47842026 47842033 47842034 47842035

Not Applicable 1.3 (365) 46.9 (365) 24.7

- 75.6 (120; 6 soils) 2.8

- 57.7 (120; 4 soils) 6.0 (365) 41.2

- 67.4 (120; 4 Brazilian soils)

Anaerobic Soil Metabolism 47842027 71.3 (149/119; no degradation during anaerobic phase) Aerobic Aquatic Metabolism 47842073 47842074 79.2

- 88.8 (105; 4 systems)

Anaerobic Aquatic Metabolism 47842073 47842074 73.1

- 76.9 (105; 4 systems)

Soil Photodegrada tion 47842028 47842029 41.4 (30) 1.6 -16.1 (12 -15)
Hydrolysis 47841919 96.0-98.0 (31)
Aqueous Photolysis 47841921 3.4 . pH 5(30) 70.4 @ pH 7 (30) 62.4 nat.wat. (30) Terrestrial

Field Dissipation 47842038 47842039 47842040 1.6

- 1.7 μ g/kg (3 reps; 363)

MAJOR DEGRADATES 22

 Code Name Chemical Name Chemical Structure Study Type MRID(s) Maximum %AR (day) A,B Final %AR (study length or

last interval

detected)
CSCC163768 SYN504810 IUPAC: 6-(Trifluoromethyl)pyridine2,3 -dicarboxylic acid CAS : 6-trifluoromethylpyridine -2,3- dicarboxylic acid CAS No . 90376-94-6

MW : 235.1 g/mol Formula : C 8 H 4 F 3 NO 4 SMILES: c1cc(nc(c1C(=O)O)C(=O)O) C(F)(F)F N

F F
F O

O H O OH Aqueous Photolysis 47841921 26.6@ pH 5 (30) 2.9@ pH 7 (30) 3.0 nat.wat. (30) 26.6@ pH 5(30) 2.9@ pH 7 (30) 3.0 nat.wat. (30)

Soil Photolysis 47842029 11.7-17.8 (6- 15) C 10.7

- 17.8 (12-15)

47842028 9.6 (30) 9.6 (30)

835.4100 Aerobic Soil Metabolism 47842033 (7 soils) D ND- 0.9 (79) ND (120)-0.5 (365)

47842034 (5 soils) D 0.7- 1.2 (14) ND (120- 365)

47842035 (4 soils) 0.1(3, 120)- 1.5(92) ND

- 0.08 (120)

835.4300 Aerobic Aquatic Metabolism 47842073 1.7- 2.8 (60) 0.15

- 0.85 (105)

*NonGuideline* Aer. Aquatic

Metab. + Photodeg. 47842075 43.4 (29)

- 50.1 (16) 37.3- 43.4 (29)

835.4400 Anaerobic Aquatic Metabolism 47842073 8.3- 9.1 (365) 8.3- 9.1 (365)

835.6100 Terrestrial

Field Dissipation 47842038 47842039 47842040 6.2 (3) ND ND 1.5 (14) ND ND 23

 Code Name Chemical Name Chemical Structure Study Type MRID(s) Maximum %AR (day) A,B Final %AR (study length or

last interval

detected)
CSAA456156 CGA375529 IUPAC: 6-Trifluoro-methylpyridine -3- carboxylic acid CAS : 6 -Trifluoromethyl

pyridine -2,3- dicarboxylic acid

Formula: C 7 H 4 F 3 NO 2 MW: 191.108 g/mol SMILES: c1cc(ncc1C(=O)O)C(F)(F)F * Non

Guideline * Aer. Aquatic

Metab. + Photodeg. 47842075 19.7

- 20.6 (29) 19.7- 20.6 (29)

CSAA589691 (NOA412101) IUPAC: (1S,3R)- Cyclopentane -1,3- dicarboxylic acid CAS : (1S,3R)- Cyclopentane1,3 -dicarboxylic acid CAS No . 876-05-1

Formula: C7 H10 O4 MW: 158.1 g/mol SMILES: C1CC(CC1C(=O)O)C(=O)O O H O O O H Aqueous Photolysis 47841921 26.3@pH 5 (18) 18.7@ pH 7 (30)

14.5 nat.wat. (30) 21.1@pH 5(30) 18.7@ pH 7 (30) 14.5 nat.wat. (30)

Soil Photolysis 47842028 1.4 (0) 1.4 (0)

CSCD642512 (SYN545859) IUPAC: 2-[[3-(2,4- Dioxobicyclo[3.2.1]octane-3- Soil Photolysis 47842029 2.2-4.1 (4 -9) ND- 3.2 (15) 24

 Code Name Chemical Name Chemical Structure Study Type MRID(s) Maximum %AR (day) A,B Final %AR (study length or

last interval

detected) carbonyl)-6-(trifluoromethyl)- 2-pyridyl]methoxy]acetic acid CAS : [3-(2-Hydroxy-4- oxobicyclo[3.2.1]oct -2-ene-3

- carbonyl) -6- trifluoromethylpyridin -2-ylmethoxy]- acetic acid

Formula: C 18 H 16 F 3 NO 6 MW : 399.3 g/mol SMILES: c1cc(nc(c1C(=O)C2C(=O)C3 CCC(C3)C2=O)COCC(=O)O )C(F)(F)F 47842028 6.2 (30) 6.2 (30)

835.4100 Aerobic Soil Metabolism 47842033 (7 soils) D 0.7 (35)-5.9 (120) ND (365)-5.9 (120)

O N O O

F F

F O OH OH 47842034 (5 soils) D 1.2 (50)-6.0 (120) 0.6- 6.0 (120)

47842035 (4 soils) 1.2 (28)- 12.1 (92) ND

- 10.84 (120)

835.4200 Anaerobic Soil Metabolism 47842027 2.9 (89) 2.3 (119)

835.6100 Terrestrial

Field Dissipation 47842038 47842039 47842040 ND 2.5 (3) 0.7 (120) ND 1.2 (14) 0.7 (120)

CSCD656832* IUPAC: 3-Hydroxy-6- Soil 47842029 7.0-8.0 (12-15) 5.8-8.0 (12-15) 25

 Code Name Chemical Name Chemical Structure Study Type MRID(s) Maximum %AR (day) A,B Final %AR (study length or

last interval

detected) (SYN545680) *This compound will be included as a residue of concern in the ecological risk assessment. (trifluoromethyl)pyridine-2- carboxylic acid CAS : 3-Hydroxy-6- trifluoromethyl -pyridine- 2- carboxylic acid

Formula: C 7 H 4 F 3 NO 3 MW: 207.1 g/mol SMILES: c1cc(nc(c1O)C(=O)O)C(F)(F) F Photolysis

47842028 4.8 (30) 4.8 (30)

835.4100 Aerobic Soil Metabolism 47842033 (7 soils) D 2.8-9.8 (79) 3.5- 7.9 (120)

47842034 (5 soils) D 0.1(79)- 14.4(120) ND- 12.2(120)

47842035 (4 soils) 0.2(64)

- 1.4(120) ND

- 1.45 (120)

835.6100 Terrestrial

Field Dissipation 47842038 47842039 47842040 11.8 (21) ND ND 2.3 (180) ND ND

SYN503780 (CSAA794148 ) IUPAC: 2-(2-Methoxyethoxymethyl) -6- (trifluoromethyl)

- nicotinic acid CAS : 3-pyridinecarboxylic Aqueous Photolysis 47841921 6.3@ pH 5 (10) 2.9@ pH 7 (30) 4.9 nat.wat.(30) 1.9@ pH 5 (30) 2.9@ pH 7(30) 4.9 nat.wat. (30) Soil Photolysis 47842029 35.8-62.5 (3- 15) C 35.8

- 62.5 (12-15) 26

 Code Name Chemical Name Chemical Structure Study Type MRID(s) Maximum %AR (day) A,B Final %AR (study length or

last interval

detected) acid, 2-[(2- methoxyethoxy)methyl]

- 6- (trifluoromethyl) -

Formula: C 11 H 12 F 3 NO 4 MW: 279.2 g/mol SMILES: COCCOCc1c(ccc(n1)C(F)(F) F)C(=O)O 47842028 25.3 (30) 25.3 (30)

835.4100 Aerobic Soil Metabolism 47842033 (7 soils) D 0.5 (120)-6.3 (50) ND- 5.8 (120)

47842034 (5 soils) D 0.6 (7) - 4.2 (21) ND- 2.4 (120)

47842035 (4 soils) 1.4(92)

- 2.1(6) ND

- 1.96 (120)

835.4200 Anaerobic Soil Metabolism 47842027 3.4 (60) 2.9 (119)

835.4300 Aerobic Aquatic Metabolism 47842073 2.3 (105)- 2.9 (60) 1.5- 2.5 (105)

*NonGuideline* Aer. Aquatic

Metab. + Photodeg. 47842075 3.4 (3)

- 4.4 (16) ND- 1.5 (29)

835.4400 Anaerobic Aquatic Metabolism 47842073 3.8 (182)- 4.3 (91) 2.9- 4.0 (365) 27

 Code Name Chemical Name Chemical Structure Study Type MRID(s) Maximum %AR (day) A,B Final %AR (study length or

last interval

detected)
835.6100 Terrestrial

Field Dissipation 47842038 47842039 47842040 7.9 (1) 20.4 (3,7) 14.0 (1) 1.3 (180) 5.8 (28) 1.5 (21)

CO 2 Carbon dioxide

Formula: CO 2 MW: 44.1 g/mol SMILES: O=C=O



### O O Aqueous Photolysis 47841921 4.7 @ pH 5 (30) 4.7 @ pH 7 (30) 0.6 nat.wat. (30) 4.7 @ pH 5 (30) 4.7 @ pH 7 (30) 0.6 nat.wat. (30) Soil Photolysis 47842029 1.8-2.5 (12-15) 1.8-2.0 (12-15) 47842028 20.1 (30) 20.1 (30)

835.4100 Aerobic Soil Metabolism 47842026 (1 soil) 75.8 (365) 75.8 (365)

47842033 (7 soils) D 4.8

- 44.1 (120) 4.8- 44.1 (120)

47842034 (5 soils) D 10.7

- 65.8 (120) 10.7

- 65.8 (120)

47842035 (4 soils) 11.4 (120)-26.2 (120) 11.4 (120)-26.2 (120) 835.4200 Anaerobic S oil Metabolism 47842027 8.7 (89) 7.6 (89)

835.4300 Aerobic aquatic metabolism 47842073 1.0-1.4 (105) 1.0-1.4 (105)

47842074 2.6 (60)-4.5 (105) 2.5- 4.5 (105)

*NonGuideline* Aer. Aquatic

Metab. + Photodeg. 47842075 0.5- 4.3 (29) 0.5- 4.3 (29)

835.4400 Anaerobic Aquatic Metabolism 47842073 0.2-0.3 (365) 0.2-0.3 (365)

47842074 3.1 (182)-7.0 (365) 2.7- 7.0 (365)

MINOR DEGRADATES 28

 Code Name Chemical Name Chemical Structure Study Type MRID(s) Maximum %AR (day) A,B Final %AR (study length or

last interval

detected)
CSAA806573 (NOA451778) IUPAC: 2-Hydroxymethyl-6- trifluoromethyl

- nicotinic acid CAS : 2-Hydroxymethyl- 6- trifluoromethyl

- nicotinic acid

Formula: C8 H6 F3 N O3 MW: 221.1 g/mol SMILES: c1cc(nc(c1C(=O)O)CO)C(F)(F)F N O

O H

CF 3 OH Aqueous Photolysis 47841921 5.5@ pH 5 (30) ND @ pH 7 2.3 nat.wat (30) 5.5@ pH 5 (30) ND@ pH 7 2.3 nat.wat.(30) 835.4200 Anaerobic Soil Metabolism 47842027 1.2 (119) 1.2 (119)

835.4400 Anaerobic Aquatic Metabolism 47842073 0.5- 2.0 (91) ND (365)

835.6100 Terrestrial

Field Dissipation 47842038 47842039 47842040 2.1 (1) ND 3.5 (4) 1.8 (7) ND 3.5 (4)

CSAA915194 (NOA454598) IUPAC: 4-Hydroxy-3-[2-(2- hydroxy -ethoxymethyl)-6- trifluoromethyl -pyridine-3- carbonyl] -bicyclo[3.2.1]oct-3 -en2- one CAS : 4-Hydroxy-3-[2-(2

- hydroxy -ethoxymethyl)-6

- trifluoromethyl -pyridine- 3- carbonyl]

- bicyclo[3.2.1]oct-3-

en -2-one

Formula: C 18 H 18 F 3 NO 5 MW: 385.3g/mol SMILES: c1cc(nc(c1C(=O)C2=C(C3CCC( C3)C2=O)O)COCCO)C(F)(F)F 835.4300 Aerobic Aquatic Metabolism 47842073 1.6- 2.0 (105) 1.6- 2.0 (105)

*NonGuideline* Aer. Aquatic

Metab. + Photodeg. 47842075 7.1- 7.6 (6) 0.5- 5.1 (29)

835.4400 Anaerobic Aquatic Metabolism 47842073 1.2 (365)- 1.6 (182) 1.2- 1.3 (365) OH

O N O OH O

CF 3

###  29

 Appendix B SURFACE WATER MODELING OUTPUT FILES ASSOCIATED WTIH RECOMMENDED EDWCS
MS Corn SWCC Results Summary 

# Summary of Water Modeling of bicyclo pyrone and the USEPA Standard Reservoir Estimated Environmental Concentrations for bicyclopyrone are presented in Table 1 for the USEPA standard reservoir with the MScornSTD field scenario. A graphical presentation of the year-to-year peaks is presented in Figure 1. These values were generated with the Surface Water Concentration Calculator (SWCC Version 1.106). Critical input values for the model are summarized in Tables 2 and 3. This model estimates that about 3.1% of bicyclopyrone a pplied to the field eventually reaches the water body. The main mechanism of transport from the field to the water body is by runoff (92.5% of the total transport), followed by spray drift (6.27%) and erosion (1.19%). In the water body, pesticide dissipates with an effect ive water column half-life of 40.4 days. (This value does not include dissipation by transport to the benthic region; it includes only processes that result in removal of pesticide from the complete system.) The main source of di ssipation in the water column is washout (effective average half-life = 43.2 days) followed by metabolism (694 days), photolysis (6211.3 days), and volatilization (2.521465E+09 days). In the benthic region, pesticide is stable. Most of the pesticide in the benthic region (61%) is sorbed to sediment rather than in the pore water.

Table 1. Estimated Environmental Concen trations (ppb) for bicyclopyrone. Peak (1-in-10 yr) 2.87 4-day Avg (1-in-10 yr) 2.77 21-day Avg (1-in-10 yr) 2.44 60-day Avg (1-in-10 yr) 1.85 365-day Avg (1-in-10 yr) 0.469
Entire Simulation Mean 0.180

Table 2. Summary of Model Inputs for bicyclopyrone.
Scenario MScornSTD Cropped Area Fraction 0.61 Kd (ml/g) 0.59 Water Half-Life (days) @ 20 °C 667.2 Benthic Half-Life (days) @ 20 °C 0 Photolysis Half-Life (days) @ 40 °Lat 50.1

Hydrolysis Half-Life (days) 0 Soil Half-Life (days) @ 20 °C 213.2

###  30

 Foliar Half-Life (days) 0
Molecular Wt 399.4 Vapor Pressure (torr) 3.8e-8 Solubility (mg/l) 119e3

Table 3. Application Schedule for bicyclopyrone. Date (Days Since Emergence) Type Amount (kg/ha) Eff. Drift

-7 Ground 0.05 0.99 0.064

Figure 1. Yearly Peak Concentrations

SWCC Output File MS Corn Variable Volume Water Model, SWCC Compatible Version

******************************************* Performed on: 9/ 9/2014 at 10:27

Peak 1-in-10 = 2.87 ppb Chronic 1-in-10 = 0.469 ppb Simulation Avg = 0.180 ppb 4-day avg 1-in-10 = 2.77 ppb 21-day avg 1-in-10 = 2.44 ppb 60-day avg 1-in-10 = 1.85 ppb 90-day avg 1-in-10 = 1.51 ppb

Benthic Pore Water Peak 1-in-10 = 1.47 ppb Benthic Pore Water 21-day avg 1-in-10 = 1.46 ppb Benthic Conversion Factor = 0.960 -Pore water (ug/L) to (total mass, ug)/(dry sed mass,kg) Benthic Mass Fraction in Pore Water = 0.386

###  31

 YEAR Peak 4-day 21-day 60-day 90-day Yearly Avg Benthic Pk Benthic 21-day 1 3.46E-01 3.34E-01 2.95E-01 2.28E-01 1.88E-01 5.99E-02 1.49E-01 1.48E-01 2 2.55E+00 2.48E+00 2.25E+00 1.73E+00 1.42E+00 4.42E-01 1.48E+00 1.47E+00 3 2.30E-01 2.22E-01 1.96E-01 1.50E-01 1.25E-01 4.58E-02 1.35E-01 1.54E-01 4 2.69E+00 2.60E+00 2.31E+00 1.72E+00 1.41E+00 4.37E-01 1.37E+00 1.37E+00 5 1.52E-01 1.47E-01 1.27E-01 9.67E-02 8.11E-02 2.98E-02 1.31E-01 1.49E-01 6 2.42E-01 2.34E-01 2.06E-01 1.54E-01 1.26E-01 4.19E-02 9.80E-02 9.75E-02 7 5.03E-01 4.86E-01 4.36E-01 3.71E-01 3.13E-01 1.02E-01 2.76E-01 2.74E-01 8 2.04E+00 1.98E+00 1.76E+00 1.34E+00 1.10E+00 3.44E-01 1.15E+00 1.15E+00 9 3.99E-01 3.85E-01 3.39E-01 2.59E-01 2.13E-01 7.18E-02 1.75E-01 1.74E-01 10 2.21E-01 2.14E-01 1.96E-01 1.52E-01 1.26E-01 4.10E-02 9.89E-02 9.84E-02 11 1.31E+00 1.27E+00 1.12E+00 8.42E-01 6.87E-01 2.16E-01 5.59E-01 5.56E-01 12 1.36E-01 1.32E-01 1.22E-01 1.03E-01 8.74E-02 3.05E-02 7.67E-02 8.64E-02 13 9.74E-01 9.46E-01 8.23E-01 6.62E-01 5.47E-01 1.72E-01 4.36E-01 4.34E-01 14 2.51E+00 2.42E+00 2.13E+00 1.60E+00 1.30E+00 4.08E-01 1.38E+00 1.37E+00 15 5.20E-01 5.03E-01 4.56E-01 3.45E-01 2.82E-01 9.30E-02 2.42E-01 2.41E-01 16 1.81E-01 1.75E-01 1.60E-01 1.32E-01 1.10E-01 3.85E-02 9.01E-02 8.97E-02 17 2.89E+00 2.79E+00 2.46E+00 1.86E+00 1.52E+00 4.72E-01 1.31E+00 1.30E+00 18 3.42E-01 3.30E-01 3.07E-01 2.37E-01 1.94E-01 6.60E-02 1.68E-01 1.67E-01 19 3.13E+00 3.06E+00 2.78E+00 2.18E+00 1.80E+00 5.64E-01 1.99E+00 1.98E+00 20 1.52E+00 1.48E+00 1.30E+00 9.67E-01 7.87E-01 2.51E-01 6.07E-01 6.04E-01 21 3.58E-01 3.46E-01 3.00E-01 2.29E-01 1.90E-01 6.26E-02 1.81E-01 1.81E-01 22 7.35E-01 7.10E-01 6.19E-01 4.63E-01 3.77E-01 1.20E-01 2.92E-01 2.90E-01 23 5.04E+00 4.93E+00 4.34E+00 3.27E+00 2.67E+00 8.34E-01 2.75E+00 2.74E+00 24 4.06E-01 3.93E-01 3.50E-01 2.89E-01 2.40E-01 8.44E-02 2.55E-01 2.90E-01 25 6.06E-01 5.86E-01 5.17E-01 4.11E-01 3.39E-01 1.07E-01 3.27E-01 3.25E-01 26 1.31E-01 1.26E-01 1.10E-01 8.70E-02 7.36E-02 2.45E-02 6.00E-02 5.97E-02 27 1.19E-01 1.15E-01 1.05E-01 8.19E-02 7.37E-02 2.51E-02 5.82E-02 5.78E-02

###  32

 28 3.71E-01 3.58E-01 3.11E-01 2.31E-01 1.91E-01 6.32E-02 1.48E-01 1.47E-01 29 6.75E-01 6.60E-01 5.80E-01 4.57E-01 3.78E-01 1.20E-01 3.58E-01 3.56E-01 30 1.84E-01 1.77E-01 1.57E-01 1.24E-01 1.07E-01 3.71E-02 8.69E-02 8.64E-02

************************************************************************************* *************** Effective compartment halflives averaged over simulation duration:

washout halflife (days) = 43.1692326062024 water col metab halflife (days) = 693.972941787900 zero hydrolysis 0 photolysis halflife (days) = 6211.31147099988 volatile halflife (days) = 2521465127.67502 total water col halflife (days) = 40.3769241376847

zero burial 0 zero benthic metab 0 zero benthic hydrolysis 0 zero benthic total degradation 0 *********************************************************************** Fractional Contribution of Transport Processes to Waterbody & Total Mass (kg):

Due to Runoff = 0.9254 4.548 Due to Erosion = 0.0119 0.5845E-01 Due to Drift = 0.0627 0.3080 *********************************************************************** Flow in/out Characteristics of Waterbody: Average Daily Runoff Into Waterbody (m3/s) = 2.678361526923428E-002 Baseflow Into Waterbody (m3/s) = 0.000000000000000E+000 Average Daily Flow Out of Waterbody (m3/s) = 2.678361526923416E-002 *********************************************************************** Inputs: 14.75 = oc partitioning coefficient 667.2 = water column half Life 20.00 = reference temp for water column degradation 0.000 = benthic Half Life 20.00 = Reference temp for benthic degradation 2.000 = Q ten value 50.10 = photolysis half life 40.00 = reference latitude for photolysis study 0.000 = hydrolysis half life 399.4 = molecular wt 0.3800E-07 = vapor pressure 0.1190E+06 = solubility 0.1728E+07 = field area 0.5260E+05 = water body area 2.740 = initial depth 2.740 = maximum depth 3 1=vvwm, 2=usepa pond, 3 = usepa reservoir, 4 = const vol no flow, 5 = const vol w/flow F T = burial, else no burial 0.1000E-07 = mass transfer coefficient 0.5000 = PRBEN 0.5000E-01 = benthic compartment depth 0.5000 = benthic porosity

###  33

 1.350 = benthic bulk density 0.4000E-01 = OC frcation in benthic sediment 5.000 = DOC in benthic compartment 0.6000E-02 = benthic biomass 1.190 = DFAC 30.00 = SS 0.5000E-02 = chlorophyll 0.4000E-01 = OC frcation in water column SS 5.000 = DOC in water column 0.4000 = biomass in water column FRACTION AREA CROPPED = 0.610000000000000


### NE Corn SWCC Results Summary 

# Summary of Water Modeling of bicyclo pyrone and the USEPA Standard Reservoir Estimated Environmental Concentrations for bicyclopyron e are presented in Table 1 for the USEPA standard reservoir with the NECornStd field scenario. A graphical presentation of the year-to-year peaks is presented in Figure 1. These values were generated with the Surface Water Concentration Calculator (SWCC Version 1.106). Critical input values for the model are summarized in Tables 2 and 3. This model estimates that about 3.1% of bicyclopyrone a pplied to the field eventually reaches the water body. The main mechanism of transport from the field to the water body is by runoff (93.4% of the total transport), followed by spray drift (6.32%) and erosion (0.33%). In the water body, pesticide dissipates with an effect ive water column half-life of 90.5 days. (This value does not include dissipation by transport to the benthic region; it includes only processes that result in removal of pesticide from the complete system.) The main source of di ssipation in the water column is washout (effective average half-life = 100.6 days) followed by metabolism (997.6 days), photolysis (9198.2 days), and volatilization (2.537305E+09 days). In the benthic region, pesticide is stable. Most of the pesticide in the benthic region (61%) is sorbed to sediment rather than in the pore water.

Table 1. Estimated Environmental Concen trations (ppb) for bicyclopyrone. Peak (1-in-10 yr) 2.71 4-day Avg (1-in-10 yr) 2.67 21-day Avg (1-in-10 yr) 2.55 60-day Avg (1-in-10 yr) 2.21 365-day Avg (1-in-10 yr) 0.857
Entire Simulation Mean 0.388

Table 2. Summary of Model Inputs for bicyclopyrone.
Scenario NECornStd Cropped Area Fraction 0.61 Kd (ml/g) 0.59 Water Half-Life (days) @ 20 °C 667.2

###  34

 Benthic Half-Life (days) @ 20 °C 0 Photolysis Half-Life (days) @ 40 °Lat 50.1

Hydrolysis Half-Life (days) 0 Soil Half-Life (days) @ 20 °C 213.2 Foliar Half-Life (days) 0
Molecular Wt 399.4 Vapor Pressure (torr) 3.8e-8 Solubility (mg/l) 119e3

Table 3. Application Schedule for bicyclopyrone. Date (Days Since Emergence) Type Amount (kg/ha) Eff. Drift

-7 Ground 0.05 0.99 0.064

Figure 1. Yearly Peak Concentrations

SWCC Output File NE Corn Variable Volume Water Model, SWCC Compatible Version

******************************************* Performed on: 9/ 9/2014 at 12:46

Peak 1-in-10 = 2.71 ppb Chronic 1-in-10 = 0.857 ppb Simulation Avg = 0.388 ppb 4-day avg 1-in-10 = 2.67 ppb 21-day avg 1-in-10 = 2.55 ppb

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 60-day avg 1-in-10 = 2.21 ppb 90-day avg 1-in-10 = 1.98 ppb

Benthic Pore Water Peak 1-in-10 = 1.53 ppb Benthic Pore Water 21-day avg 1-in-10 = 1.53 ppb Benthic Conversion Factor = 0.960 -Pore water (ug/L) to (total mass, ug)/(dry sed mass,kg) Benthic Mass Fraction in Pore Water = 0.386

YEAR Peak 4-day 21-day 60-day 90-day Yearly Avg Benthic Pk Benthic 21-day 1 1.24E+00 1.22E+00 1.16E+00 9.97E-01 8.91E-01 3.54E-01 6.71E-01 6.70E-01 2 6.10E-01 6.00E-01 5.70E-01 4.91E-01 4.39E-01 2.38E-01 3.66E-01 3.84E-01 3 3.89E-01 3.82E-01 3.71E-01 3.27E-01 2.93E-01 1.48E-01 2.35E-01 2.35E-01 4 1.56E+00 1.54E+00 1.44E+00 1.24E+00 1.11E+00 4.65E-01 8.46E-01 8.43E-01 5 2.03E+00 2.00E+00 1.89E+00 1.63E+00 1.46E+00 6.56E-01 1.12E+00 1.12E+00 6 2.67E+00 2.65E+00 2.49E+00 2.14E+00 1.91E+00 8.58E-01 1.48E+00 1.48E+00 7 5.40E-01 5.33E-01 5.12E-01 5.81E-01 6.55E-01 2.79E-01 7.41E-01 7.87E-01 8 4.62E-01 4.55E-01 4.32E-01 3.75E-01 3.36E-01 1.61E-01 2.64E-01 2.63E-01 9 2.34E+00 2.30E+00 2.15E+00 1.90E+00 1.70E+00 7.05E-01 1.30E+00 1.29E+00 10 7.48E-01 7.35E-01 6.97E-01 6.15E-01 5.80E-01 3.25E-01 6.56E-01 6.96E-01 11 2.00E+00 1.97E+00 1.84E+00 1.59E+00 1.42E+00 6.07E-01 1.12E+00 1.12E+00 12 3.38E-01 3.40E-01 3.61E-01 4.17E-01 4.71E-01 1.51E-01 5.38E-01 5.72E-01 13 8.93E-01 8.78E-01 8.20E-01 7.04E-01 6.29E-01 2.62E-01 4.66E-01 4.64E-01 14 3.16E+00 3.11E+00 2.93E+00 2.53E+00 2.26E+00 9.50E-01 1.80E+00 1.79E+00 15 5.40E-01 5.44E-01 5.77E-01 6.67E-01 7.52E-01 2.29E-01 8.57E-01 9.11E-01 16 3.50E+00 3.46E+00 3.24E+00 2.79E+00 2.49E+00 1.01E+00 1.88E+00 1.88E+00 17 1.43E+00 1.40E+00 1.32E+00 1.13E+00 1.01E+00 5.53E-01 9.54E-01 1.01E+00 18 3.04E-01 2.99E-01 2.90E-01 3.02E-01 3.41E-01 1.54E-01 3.91E-01 4.16E-01 19 3.38E-01 3.33E-01 3.19E-01 2.94E-01 2.69E-01 1.24E-01 2.13E-01 2.13E-01 20 4.09E-01 4.05E-01 3.80E-01 3.29E-01 2.94E-01 1.36E-01 2.28E-01 2.27E-01 21 1.06E+00 1.04E+00 9.73E-01 8.38E-01 7.52E-01 3.23E-01 5.95E-01 5.93E-01 22 2.71E+00 2.67E+00 2.55E+00 2.22E+00 1.99E+00 8.48E-01 1.53E+00 1.53E+00 23 1.47E+00 1.45E+00 1.36E+00 1.21E+00 1.10E+00 5.65E-01 9.21E-01 9.18E-01 24 6.77E-01 6.67E-01 6.27E-01 5.44E-01 4.89E-01 2.64E-01 4.33E-01 4.60E-01

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 25 7.07E-01 6.96E-01 6.55E-01 5.66E-01 5.07E-01 2.33E-01 4.06E-01 4.05E-01 26 1.86E-01 1.83E-01 1.71E-01 1.52E-01 1.71E-01 8.99E-02 1.95E-01 2.07E-01 27 7.19E-01 7.07E-01 6.61E-01 5.77E-01 5.19E-01 2.20E-01 3.87E-01 3.86E-01 28 1.39E+00 1.37E+00 1.30E+00 1.12E+00 1.00E+00 4.32E-01 7.53E-01 7.51E-01 29 2.65E-01 2.61E-01 2.59E-01 2.99E-01 3.37E-01 1.43E-01 3.81E-01 4.05E-01 30 5.10E-01 5.04E-01 4.78E-01 4.19E-01 3.76E-01 1.67E-01 2.91E-01 2.91E-01

***************************************************************************************** *********** Effective compartment halflives averaged over simulation duration:

washout halflife (days) = 100.575892719632 water col metab halflife (days) = 997.620816648772 zero hydrolysis 0 photolysis halflife (days) = 9198.21728135637 volatile halflife (days) = 2537305452.85619 total water col halflife (days) = 90.4662794303390

zero burial 0 zero benthic metab 0 zero benthic hydrolysis 0 zero benthic total degradation 0 *********************************************************************** Fractional Contribution of Transport Processes to Waterbody & Total Mass (kg):

Due to Runoff = 0.9335 4.549 Due to Erosion = 0.0033 0.1625E-01 Due to Drift = 0.0632 0.3080 *********************************************************************** Flow in/out Characteristics of Waterbody: Average Daily Runoff Into Waterbody (m3/s) = 1.149607611056183E-002 Baseflow Into Waterbody (m3/s) = 0.000000000000000E+000 Average Daily Flow Out of Waterbody (m3/s) = 1.149607611056210E-002 *********************************************************************** Inputs: 14.75 = oc partitioning coefficient 667.2 = water column half Life 20.00 = reference temp for water column degradation 0.000 = benthic Half Life 20.00 = Reference temp for benthic degradation 2.000 = Q ten value 50.10 = photolysis half life 40.00 = reference latitude for photolysis study 0.000 = hydrolysis half life 399.4 = molecular wt 0.3800E-07 = vapor pressure 0.1190E+06 = solubility 0.1728E+07 = field area 0.5260E+05 = water body area 2.740 = initial depth 2.740 = maximum depth 3 1=vvwm, 2=usepa pond, 3 = usepa reservoir, 4 = const vol no flow, 5 = const vol w/flow F T = burial, else no burial

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 0.1000E-07 = mass transfer coefficient 0.5000 = PRBEN 0.5000E-01 = benthic compartment depth 0.5000 = benthic porosity 1.350 = benthic bulk density 0.4000E-01 = OC frcation in benthic sediment 5.000 = DOC in benthic compartment 0.6000E-02 = benthic biomass 1.190 = DFAC 30.00 = SS 0.5000E-02 = chlorophyll 0.4000E-01 = OC frcation in water column SS 5.000 = DOC in water column 0.4000 = biomass in water column FRACTION AREA CROPPED = 0.610000000000000

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 GROUNDWATER MODELING OUTPUT FILES 

## SCIGROW Output

SCIGROW VERSION 2.3 ENVIRONMENTAL FATE AND EFFECTS DIVISION OFFICE OF PESTICIDE PROGRAMS U.S. ENVIRONMENTAL PROTECTION AGENCY SCREENING MODEL FOR AQUATIC PESTICIDE EXPOSURE

SciGrow version 2.3 chemical:bicyclo 2 time is 8/21/2014 11:46:13

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

------------------------------------------------------------------------ 0.045 1.0 0.045 7.00E+00 125.5

------------------------------------------------------------------------ groundwater screening cond (ppb) = 1.32E+00 ************************************************************************

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## PRZM-GW Output

Groundwater Analysis for bicyclopyrone and the Wi sconsin Corn - WI Central Sands Scenario (Extended 100-year Simulation) Estimated groundwater concentrations and breakthrough ti mes for bicyclopyrone are presented in Table 1 for the Wisconsin Corn - WI Central Sands groundwater scenario. A graphical presentation of the daily concentrations in the aquifer is presented in Figure 1. These values were generated with the PRZM-GW (Version 1.07). Critical input values for the m odel are summarized in Tables 2 and 3.

Table 1. Groundwater Results for bicyclopyrone and th e Wisconsin Corn - WI Central Sands Scenario. Peak Concentration (ppb) 6.07 Post-Breakthrough Mean Concentration (ppb) 5.64

Entire Simulation Mean Concentration (ppb) 3.89

Average Breakthrough Time (days) 12079.23

Throughputs 2.993735

Table 2. Chemical Properties for Groundwater Modeling of bicyclopyrone. Kd (ml/g) 0.59 Surface Soil Half Life (days) 151.1 Hydrolysis Half Life (days) 0 Diffusion Coefficint Air (cm2/day) 0.0 Henry's Constant 0.0 Enthalpy (kcal/mol) 0.0

Table 3. Pesticide application scheme used for bicyclop yrone. This application scheme was applied every year of the simulation. Application Days Relative to Emergence Date (05/01) Application Method Application Rate (kg/ha)

-7 Ground application with mass distribution increasing proportionally with depth to 4 cm 0.05

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 Figure 1. Aquifer Breakthrough Curve for Bicyclopyrone and the Wisconsin Corn - WI Central Sands Scenario (Extended 100-year Simulation)

Groundwater Analysis for bicyclopyrone and the Wisconsin Corn - WI Central Sands Scenario (Normal 30-year Simulation)

Table 1. Groundwater Results for Bicyclopyrone and th e Wisconsin Corn - WI Central Sands Scenario (Normal 30-year Simulation).
Peak Concentration (ppb) 1.93

Post-Breakthrough Mean Concentration (ppb) Incomplete (No Breakthrough)
Entire Simulation Mean Concentration (ppb) 0.32

Average Breakthrough Time (days) Incomplete

Throughputs 0.9069451



## Additional Przm-Gw Scenario Results Summaries

Groundwater Results for Bicyclopyrone and the DE LMARVA sweet corn - Evesboro loamy sand Scenario. Peak Concentration (ppb) 3.76 Post-Breakthrough Mean Concentration (ppb) 3.23

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 Entire Simulation Mean Concentration (ppb) 1.64

Average Breakthrough Time (days) 5727.522

Throughputs 1.913567

DelMarVa Sweet Corn Scenario Aquifer Breakthrough Curve



### Groundwater Results for Bicyclopyrone and the Flo rida Citrus - FL Central Ridge, Polk County - (Tampa) Met File (12842.dvf) - Astatula sand, hrgb A Scenario. Peak Concentration (ppb) 5.97 Post-Breakthrough Mean Concentration (ppb) 5.19

Entire Simulation Mean Concentrati on (ppb) 3.78

Average Breakthrough Time (days) 3238.919

Throughputs 3.383845

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 Florida Citrus Scenario Aquifer Breakthrough Curve



### Groundwater Results for Bicyclopyrone and the FLO RIDA - potato - Met File (13889.dvf) Jacksonville Scenario. Peak Concentration (ppb) 2.69 Post-Breakthrough Mean Concentration (ppb) 2.52

Entire Simulation Mean Concentration (ppb) 1.95

Average Breakthrough Time (days) 2705.307

Throughputs 4.051296

Florida Potato Scenario Aquifer Breakthrough Curve

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 Groundwater Results for Bicyclopyrone and the GA - Southern Coastal Plain, Tifton loamy sand - PEANUTS Scenario. Peak Concentration (ppb) 1.87 Post-Breakthrough Mean Concent ration (ppb) 1.69

Entire Simulation Mean Concentration (ppb) 1.03

Average Breakthrough Time (days) 4900.52

Throughputs 2.236497

Georgia Peanuts Scenario Aquifer Breakthrough Curve



### Groundwater Results for Bicyclopyrone and the NC Eastern Coastal Plain - Norfolk loamy sand - Cotton Scenario. Peak Concentration (ppb) 2.14 Post-Breakthrough Mean Concentration (ppb) 1.71

Entire Simulation Mean Concentration (ppb) 0.536

Average Breakthrough Time (days) 8582.193

Throughputs 1.277063

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 NC Eastern Coastal Plain Cotton Scenario Aquifer Breakthrough Curve