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 enzyme 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'
2

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 μg/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 μg/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 proposed 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 μg/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 (μg/L) Chronic (μg/L) Cancer (μg/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) 

3.761 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 monitoring data available for bicyclopyrone in surface 

water. Maximum residues of parent in groundwater wells at sites in Germany, Hungary, France, and Italy 

in PGW studies were 1.4 μg/L, 0.24 μg/L, 0.11 μg/L, and 0.34 μg/L respectively. Maximum residues of 
3

the transformation product SYN503780 were 0.11 μg/L, <LOQ (0.01 μg/L), 0.03 μg/L, and 0.17 μg/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 applied 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 suspension 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-metolachlor. 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 21 14 100-RUAA 

(SYN-A16003) 

Corn (field corn, 

seed corn, silage 

corn, yellow popcorn 

and sweet corn) 

0.0453 0.0453 2 

Not stated, 

but 2nd

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 maximum 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%. 
4

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 KFOCs 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 KFOCs 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. Nine field studies conducted in Europe and one field 

study conducted in Australia were also submitted. Across all sites, the dissipation 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 the 

first 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 conditions 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 studies 

conducted 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 intervals 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 Kow 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 (C19H20F3NO5) 

Physical State (pure active substance) White Powder 

Melting Point (pure active substance) 65.3°C 

Relative Density (pure active substance) 1.503 g/cm3 at 20.5°C 

Aqueous Solubility (at 25qC) 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 25qC 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 20qC < 5 · 10-6 Pa (pure) 

Henry’s Law Constant at 25qC < 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 Kow) 

At pH 5 log Kow = 0.25 

At pH 7 log Kow = -1.2 

At pH 9 log Kow = -1.9 

Acid Dissociation Constant (pKa) at 20qC 3.06 
6

Table 4. Environmental fate parameters of bicyclopyrone.

Parameter Value Source

Persistence

Hydrolysis half-life (50qC) Stable at pH 4, 5, 7, 9 MRID 47841919 

Aqueous photolysis half-life (25qC) 11.1 days @ pH 5 

50.1 days @ pH7 

74.8 days in natural water @ pH 7.3 

MRID 47841921 

Soil photolysis half-life (20qC) 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 (20qC) Stable (half-life not calculated; no 

degradation during anaerobic phase) MRID 47842027 

Aerobic aquatic metabolism half-life (20qC) 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 (20qC) 

7.4, 7.5 days (2 systems) MRID 47842075 

Anaerobic aquatic metabolism half-life (20qC) 1423, 6244 (stable; 2 systems) MRID 47842073 

1159, 2077 (stable; 2 systems) MRID 47842074 

Mobility

Freundlich soil-water partition coefficients (KF); 

Freundlich organic carbon-normalized coefficients 

(KFOC) 

Parent Bicyclopyrone

KF: 0.24, 0.83, 0.37, 0.45, 1.39, 0.22, 

0.35 L/kg 

KFOC: 39, 35, 31, 11, 32, 28, 7 L/kg 

MRID 47842055 

Parent Bicyclopyrone

KF: 1.34, 0.25, 0.20, 0.14, 1.39 L/kg 

KFOC: 46, 18, 10, 14, 87 L/kg MRID 47842056 

Parent Bicyclopyrone

KF: 0.32, 1.74 L/kg 

KFOC: 29, 103 L/kg MRID 47842057 

Parent Bicyclopyrone

KF: 0.11, 0.48, 0.29, 0.13, 0.91 L/kg 

KFOC: 7, 24, 59, 11, 61 L/kg MRID 47842059 
7

Parameter Value Source

Parent Bicyclopyrone (Brazilian soils) 

KF: 1.1, 6.3, 2.2, 26.6 L/kg 

KFOC: 46, 352, 241, 264 L/kg MRID 47842058 

Degradate CSCC163768 

KF: 0.03, 0.08 L/kg 

KFOC: 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 

Values could not be determined due to 

lack of adsorption in all 4 soils. 

MRID 47842061 

Degradate CSCD656832

KF: 5.2, 38.9, 51.8, 98.9 L/kg 

KFOC: 247, 1340, 5179, 6180 L/kg 

MRID 47842155 

Field Dissipation 

Terrestrial field dissipation 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 represent this soil rather than the two individual half-lives. 

AReported 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: 
8

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

x CSAA915194 4-hydroxy-3-[2-(2-hydroxy-ethoxymethyl)-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 runoff 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 detailed 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 concentrations 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 concentrations 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). 
9

Modeling Approach and Input Parameters 

Screening-level modeling was conducted to generate 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 environmental 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 modeling 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 bicyclopyrone1. 

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 (atmm3

/mol; pH 7.2) 1.67 x 10-13 Registrant-submitted phys/chem property 

values (converted from 1.7 .

 10-8Pa m3/mol). 

Hydrolysis half-life (t1⁄2 in days; 

pH 7) Stable MRID 47841919 

Aqueous Photolysis half-life (t1⁄2

in days; pH 7) 50.1 MRID 47841921 

Aerobic Soil metabolism half-life 

(t1⁄2 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 (t1⁄2 in days) stable MRIDs 47842073, 47842074 

Aerobic Aquatic metabolism 

half-life (t1⁄2 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 KFD 

(mL/goc) 0.59 

MRIDs 47842055, 47842056, 47842057, 

47842059 

Mean Kd (mean of 19 Kds; ionic compound; 

adsorption not correlated with Koc) 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 12 

aerobic soil metabolism halflife values.1

KFOC (mL/goc) 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. 

KFD (mL/g) 0.59 

MRIDs 

47842055, 

47842056, 

47842057, 

47842059 

Mean of 19 KFD

values (ionic 

compound; adsorption 

not correlated with 

Koc) 

 1EFED input parameter guidance: http://www.epa.gov/oppefed1/models/water/przm_gw/wqtt_przm_gw_input_guidance.htm

 2Input 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 surface water maximum values. Outputs from the model 

run 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 watershed-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 (μg/L) 

1-in-10 year 

chronic (μg/L) 

30 year mean

cancer (μg/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 (μg/L) 

1-in-10 year 

chronic (μg/L) 

30 year mean

cancer (μg/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 

Modeled1

Scenario 

(Tier 1) 

Highest 

Daily 

Value 

(μg/L) 

Post 

Breakthrough 

Average (μg/L) 

Entire 

Simulation Mean 

Concentration 

(μg/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 

3.762 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. PRZMGW 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 represent groundwater concentrations that might be 

expected in shallow, unconfined aquifers under sandy soils. The SWCC modeled concentrations (μg/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 simulated 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 (Florida citrus) and with a longer simulation period (100 

years; WI corn), the recommended values are representative 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 μg/L) were first observed (0.04 μg/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 μg/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 μg/L) in one well following a wet summer period, and trace 

residues (0.02-0.09 μg/L) in two other wells following a dry spring. The transformation 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 μg/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 μg/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 

μg/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 μg/L at 848 days and 

declined to <LOQ (0.01 μg/L) by 1069 days. Bicyclopyrone was detected in two wells at ≤0.02 μg/Land 

had declined to <LOQ by 1134-1169 days. Bicyclopyrone was not detected above the LOQ (0.01 μg/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 the prevailing groundwater flow direction. Residues of 

the transformation product SYN503780 were not detected above the LOQ (0.01 μg/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 μg/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 μg/L at 951 days and was ≤0.06 μg/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 μg/L) in both shallow and deep 

wells at 404-434 days, and residues detected at a maximum of 0.03 μg/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 μg/L; 

740 and 951 days), and was detected twice in a deep well (at 951-986 days) at 0.01-0.02 μg/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 μg/L (589-1053 days). Bicyclopyrone decreased to <LOQ (0.01 μg/L) by 836-1233 days posttreatment in three wells, and was 0.05-0.13 μg/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 μg/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 

μg/L (713-746 days) and declined to <LOQ by 776-868. In two other wells, maximum SYN503780 

concentrations were 0.12-0.15 μg/L (776 days) and declined to <LOQ (0.01 μg/L) by 953-986 days. In 

two wells, SYN503780 residues were a maximum at 0.17 μg/L (807-868 days) and declined to ≤0.03 

μg/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 KFD 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 and/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 registrant. 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 stability 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 transport 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 maximum 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 utilize 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 locations 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-Encarnación, 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 International 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 anaerobic 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 14CBicyclooctenone 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 Aerobic 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. Report 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, Bracknell, Berkshire, RG42 6EY, UK. 

Report Number: 8215834-D2149, Task Number: TK011883. 

MRID 47842060 Lewis, C.; Gilbert, J. 2009. NOA449280- 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 study 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 prepared 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 prepared 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 - Validation 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 Environmental 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: C19H20F3NO5

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 CF3

N

OH O

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 μg/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: C8 H4F3NO4

SMILES: 

c1cc(nc(c1C(=O)O)C(=O)O)

C(F)(F)F

N

F

F

F

O

HO

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-Trifluoromethylpyridine-2,3-dicarboxylic acid 

Formula: C7H4F3NO2

MW: 191.108 g/mol 

SMILES: 

c1cc(ncc1C(=O)O)C(F)(F)F 

*NonGuideline* 

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 

HO

O

O HO

 

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: C18H16F3NO6

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

OH O

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: C7H4F3NO3

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: C11H12F3NO4

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 

OO

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 Soil 

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

HO

CF3

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: C18H18F3NO5 

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 O OH

CF3
29

Appendix B 

SURFACE WATER MODELING OUTPUT FILES ASSOCIATED WTIH RECOMMENDED EDWCS

MS Corn SWCC Results Summary 

Summary of Water Modeling of bicyclopyrone 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 applied 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 effective 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 dissipation 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 Concentrations (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 bicyclopyrone and the USEPA Standard 

Reservoir 

Estimated Environmental Concentrations for bicyclopyrone 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 applied 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 effective 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 dissipation 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 Concentrations (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 
35

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 
36

 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 
37

 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 
38

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 

 ************************************************************************ 

 

 
39

PRZM-GW Output 

Groundwater Analysis for bicyclopyrone and the Wisconsin Corn - WI Central Sands Scenario 

(Extended 100-year Simulation)

Estimated groundwater concentrations and breakthrough times 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 model are summarized in Tables 2 and 3. 

Table 1. Groundwater Results for bicyclopyrone and the 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 bicyclopyrone. 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 
40

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 the 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 DELMARVA sweet corn - Evesboro loamy sand 

Scenario. 

Peak Concentration (ppb) 3.76 

Post-Breakthrough Mean 

Concentration (ppb)

 3.23 
41

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 Florida 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 

Concentration (ppb) 

 3.78 

Average Breakthrough 

Time (days)

3238.919 

Throughputs 3.383845 
42

Florida Citrus Scenario Aquifer Breakthrough Curve 

Groundwater Results for Bicyclopyrone and the FLORIDA - 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 
43

Groundwater Results for Bicyclopyrone and the GA - Southern Coastal Plain, Tifton loamy sand - 

PEANUTS Scenario. 

Peak Concentration (ppb) 1.87 

Post-Breakthrough Mean 

Concentration (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 
44

NC Eastern Coastal Plain Cotton Scenario Aquifer Breakthrough Curve