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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C. 20460

OFFICE OF CHEMICAL SAFETY

AND POLLUTION PREVENTION

February 19, 2015

MEMORANDUM

SUBJECT: Drinking Water Assessment for IR4 New Uses of Spinosad and Spinetoram on 

Coffee, Berry/Low Growing Berry (Subgroup 13-07G), Berry/Small Fruit/Vine 

Climbing (Subgroup 07-07F), Bulb Vegetables (Subgroup 3-07B), Cottonseed 

(Subgroup 20C), and Dow New Proposed Uses on the Control of Root Maggot 

on Cabbage Plant (Brassica (Cole) Leafy Vegetables, Subgroup 5). 

(PC 110003 - Spinosad, 110008/110009 - Spinetoram; DP Barcodes D415813, 

415815)

FROM: Larry Liu, Chemist, Ph.D.

Environmental Risk Branch 5

Environmental Fate and Effects Division (7507P)

THROUGH: Mah T. Shamim, Ph.D., Branch Chief

Environmental Risk Branch 5

Environmental Fate and Effects Division (7509P)

TO: Tom Bloem

Health Effects Division (7509P)

Barbara Madden; RM 05

Registration Division (7505P)

Summary

Currently proposed section 3 uses and the previously-modeled turf use of spinosad and 

spinetoram were modeled using the currently-released EFED models (SWCC for surface water 

and PRZM-GW for ground water). The results of the modeling exercise indicate that turf use 

results in higher EDWCs than all the proposed new uses. Therefore, the revised EDWCs are as 

follows:

(a) For spinosad concentrations in surface water: the acute 1-in-10 years peak EDWC is 25.0

ppb, the non-cancer/chronic 1-in-10 years annual mean EDWC is 21.7 and the 1-10-years overall 
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mean cancer/chronic is 14.2 ppb. For spinetoram concentrations in surface water: the acute 1-in10 years peak EDWC is 8.6 ppb, the non-cancer/chronic 1-in-10 years annual mean EDWC is 

5.9 and the 1-10-years overall mean cancer/chronic is 3.8 ppb. 

(b) Due to the extremely high adsorption of spinosad and spinetoram with soil, even using 

100-year weather records and all available scenario (DELMARVA_STD.SCN, 

FLCITRUS_STD.SCN, FLPOTATO_STD.SCN, GACOASTAL_STD.SCN, 

NCCOASTAL_STD.SCN, WISANDS_STD.SCN) in PRZM-GW simulation, PostBreakthrough Mean Concentration (PBT) and Simulation Average Breakthrough Time (BT) 

were not achieved (See Appendix E for further details). Although the use on coffee resulted in 

the highest groundwater EDWCs in all proposed uses, these values are below detection limits 

Introduction

The Environmental Fate and Effects Division (EFED) has completed its review of an IR-4 

petition for the new uses of Spinosad (Reg. numbers 62719-266, 62719-497, and 62719-621) and 

Spinetoram (Reg. no. 62719-539, 62719-545, 62719-541) on coffee, berry/low growing berry

(subgroup 13-07G), berry/small fruit/vine climbing (subgroup 07-07F), and bulb vegetables 

(subgroup 3-07B), and cottonseed (subgroup 20C). The other actions associated with the subject 

data package codes are conversions of crop groups, which do not include new uses for 

evaluation, for berry subgroups 13-07A and B, citrus fruit group 10-10, pome fruit group 11-10, 

stone fruit group 12-12, tree nut group 14-12, onion subgroup 3-07A, and fruiting vegetable 

subgroup 8-10. Furthermore, Dow AgroSciences has requested the addition of new proposed use

for the control of root maggot (Brassica (Cole) Leafy Vegetables, Subgroup 5) at the base of 

cabbage plants and adjacent soils by utilizing banded applications.
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Uses of Characterization 

Spinosad is an insecticide and currently registered on a variety of crops and non-crops in the US. 

It controls many foliage feeding pests such as lepidopterous larvae (worms or caterpillars),

leafminers, thrips, and red imported fire ants. This product’s active ingredient, Spinosad, is 

biologically derived from the fermentation of Saccharopolyspora spinosa, and it is formulated as

an SC (suspension concentrate). Table 1 summarizes the application rates from the product label 

for all proposed new uses of spinosad. 

Table 1. Proposed New Uses of Spinosad

Products Crop Single 

Appl. Rate 

(lb ai/A)

Max # 

Appl./

Year

Minimu

m Appl. 

Interval 

(days)

Max Appl. 

Rate/Year 

(lb ai/A)

Appl. 

Methods

Entrust 

SC® 

Insecticide

Coffee 0.064-

0.164

6 5 0.45 Spray/ground, 

chemigation 

and aerial

Berry, Low 

Growing Berry

(Subgroup 13-

07G) except 

cranberry and 

lowbush berry

Berry, Small 

Fruit, Vine 

Climbing 

(Subgroup-13-

07F) except 

fuzzy kiwifruit

0.064-

0.096

0.064-

0.120

5

5

3-7

5

0.45

0.45

Spray/ground, 

chemigation 

and aerial

Spray/ground, 

chemigation 

and aerial

Bulb Vegetables 

(Subgroup 3-

07B)

0.040-

0.120

5 4 0.45 Spray/ground, 

chemigation 

and aerial

Cottonseed 

(Subgroup 20C)

0.046-

0.096

unspec

ified

5 0.45 Spray/ground, 

chemigation 

and aerial

Brassica (Cole) 

Leafy

Vegetables, 

(Subgroup 5) for 

Control of Root 

Maggot on 

Cabbage Plant

0.078-

0.156

6 4 0.45 Spray/ground
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Spinetoram is an insecticide and currently registered on a variety of crops in the US. It controls 

or suppresses many foliage feeding pests such as lepidopterous larvae (worms, caterpillars),

dipterous leafminers, thrips, and certain psyllids. This product’s active ingredient, Spinetoram, is

derived from the fermentation of Saccharopolyspora spinosa, and it is formulated as SC 

(suspension concentrate) and WG (dispersible granules). Table 2 summarizes the application 

rates from the various product labels for all proposed new uses of spinetoram. 

Table 2. Proposed New Uses of Spinetoram

Products Crop Single 

Appl. Rate 

(lb ai/A)

Max # 

Appl./

Year

Minimum 

Appl. 

Interval 

(days)

Max Appl. 

Rate/Year 

(lb ai/A)

Appl. 

Methods

Delegate 

WG® 

Insecticide

Radiant 

SC® 

Insecticide

Coffee 0.032-

0.080

6 5 0.305 Spray/ground, 

chemigation 

and aerial

Berry, Low 

Growing Berry

(Subgroup 13-

07G) except 

cranberry and 

lowbush berry

Berry, Small 

Fruit, Vine 

Climbing 

(Subgroup-13-

07F) except 

fuzzy kiwifruit

0.048-

0.080

5 3-4 0.305 Spray/ground, 

chemigation 

and aerial

Bulb Vegetables 

(Subgroup 3-

07B)

0.040-

0.080

5 4 0.234 Spray/ground, 

chemigation 

and aerial

Cottonseed 

(Subgroup 20C)

0.011-

0.064

6 4 0.266 Spray/ground, 

chemigation 

and aerial

Brassica (Cole) 

Leafy

Vegetables, 

(Subgroup 5) for 

Control of Root 

Maggot on 

Cabbage Plant

0.039-

0.078

6 4 0.266 Spray/ground
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General Physical-Chemical and Fate Properties 

Spinosad 

Spinosad (XDE-105) is a mixture of two active naturally occurring secondary degradates

(Spinosad A and Spinosad D). Even though the two degradates have analogous fate properties 

(i.e., similar half-lives in hydrolysis, aqueous photolysis, soil photolysis, aerobic soil 

metabolism, etc), the key distinction between the two spinosad components is that Factor D 

consists of an extra methyl group at carbon 4 on the central ring. In addition, spinosad A is the 

major component in parent spinosad is at approximately an 85:15 ratio. Both spinosad A and D 

have similar molecular weight (732 vs 746 g/mol respectively). Spinosad A has a greater water 

solubility than spinosad D and as pH increases water solubility decreases. Table 3 presents a 

summary of physicochemical properties of the two spinosad components.

Table 3. Summary of Physicochemical Properties of Spinosad

Physical Property Spinosad A Spinosad D

Structure

CAS Registry Number 131929-60-7 131929-63-0

Empirical Formula C41H65NO10 C42H67NO10

Molecular Weight 731.976 745.988

Odor Slightly stale water or earthy

Relative Density (20C) 0.512

Melting Point 84-99.5C 161.5-170C

Vapor Pressure (25C) 2.4E-10 mmHg

3E-11 kPa

1.6E-10 mm Hg

2E-11 kPa

Octanol/Water Partition Coefficient (log 

Kow)

pH 5

pH 7

pH 9

Distilled water

2.78

4.01

5.16

3.91

3.23

4.53

5.21

4.38

Dissociation Constant (pKa) (20C) 8.10 7.87

Water Solubility (20C)
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Physical Property Spinosad A Spinosad D

pH 5

pH 7

pH 9

Distilled water

290 mg/L

235 mg/L

16 mg/L

89.4 mg/L

28.7 mg/l

0.332 mg/L

0.053 mg/L

0.495 mg/L

Spinosad A and spinosad D converted in an aerobic soil metabolism study to degradates that are 

very identical to the parent with half-lives of approximately 9-17 days. Similar degradates are 

formed under photolytic settings with a half-life of <1 day at pH 7 in sterile water and about 10 

days in soil. Spinosad A has a low to moderate water solubility and a low to slight mobility in 

sandy soils, and is immobile in silt loam and clay loam soils. In terrestrial field dissipation 

studies with Spinosad A on bare ground plots, the half-life was <1 day, no leaching was 

observed, and 3.1% of the applied was recovered in runoff.

Spinosad has a high affinity for sediment and moves rapidly from the water to the sediment 

phases where it, together with its major degradates, is highly persistent. In anaerobic aquatic 

metabolism studies, spinosad had a half-life of 161-250 days. In an aquatic microcosm 

dissipation outdoor study, spinosad residues in the sediment peaked at 8 days and had an 

observed half-life of greater than 25 days (See Appendix A for details). 

Spinetoram 

Spinetoram (XDE-175) is a new second generation spinosyn insecticide consisting of a mixture 

of spinetoram J and spinetoram L at roughly 3:1 ratio. These two components are not isomers. 

Furthermore, spinetoram J is the major component in the spinetoram mixture, and the distinction 

between both components is that spinetoram L contains an extra methyl group at carbon 4 on the 

central ring. Spinetoram L is slightly heavier (760 g/mol) than spinetoram J (748 g/mol), and 

spinetoram J has a lower water solubility than spinetoram L, that is, spinetoram L is more soluble 

in water at pH 5 and 7 (See Table 4). 

Based on laboratory studies, both components of spinetoram dissipate rapidly by photolysis in 

pH 7 buffer solution, with half-lives of <1 day. Other major routes of dissipation are aerobic soil 

metabolism, with non-linear half-lives of 3-31 days, and photolysis in soil, with environmental 

half-lives of 19-88 days. In aerobic and anaerobic water/sediment systems, spinetoram rapidly 

associates with the sediment phase where dissipation proceeds more slowly. Half-lives in total 

aerobic water/sediment systems were 116-124 days, and in total anaerobic water/sediment 

systems were 385-1,386 days. In laboratory soil, spinetoram was generally immobile (Kd = 84 

and Koc =8,570). Under terrestrial and aquatic field conditions, spinetoram dissipated rapidly, 

with observed half-lives of ≤1 day. Leaching was not significant under terrestrial field 

conditions, and migration into sediments was not significant under aquatic field conditions. 

The octanol/water partitioning coefficients for spinetoram J and spinetoram L are 12,303 and 

30,903, respectively. Spinetoram (both components), does accumulate in fish. In rainbow trout 

exposed to spinetoram J, the bioconcentration factors (BCFs) for edible tissue, nonedible tissue, 

and whole fish were 11, 53, and 46 mL/g, respectively. In rainbow trout exposed to spinetoram 
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L, the BCFs for edible tissue, nonedible tissue, and whole fish were 104, 330, and 344 mL/g, 

respectively (See Appendix B for details).

 

Table 4. Physical/Chemical and Fate Properties of Spinetoram 

Spinetoram J Spinetoram L

Chemical Structure

Molecular Weight 

(g/mol)

748 760

Water Solubility -pH 5 423 ppm 1630 ppm

 pH 7 11.3 ppm 46.7 ppm

 pH 9 8 ppm 2 ppm

 pH 10 6.3 ppm 0.7 ppm

Log Kow 4.09 4.38

Vapor Pressure 5.3x10-5 Pa 2.1x10-5 PA

Hydrolysis, pH 5 (halflife)Stable stable

Hydrolysis, pH 7 (halflife)Stable stable

Hydrolysis, pH 9 (halflife)Stable 158 days

Aqueous Photolysis 

(pH 7) (half-life of 

parent)

0.5 day 0.2 day

Soil Photolysis (halflife)27.4 days 9.4 days

Aerobic Soil 

Metabolism (half-life)

26.5 days (CA) 17.9 days (CA)

8.6 days (VA) 3.2 days (VA)

22.7 days (MS) 19.1 days (MS)

30.8 days (IA) 15.3 days (IA)

Anaerobic Aquatic 

Metabolism (half-life)

385 days (total system) 1,386 days (total system)

Aquatic Aerobic 

Metabolism (half-life)

116 days (total system) 124 days (total system)

Kd/Koc (loamy sand) 14/1800 31/3936

Kd/Koc (silt loam) 271/24648 483/43873

Kd/Koc (sandy loam) 38/5490 92/13185

Kd/Koc (loam) 12/2344 24/4816

Terrestrial Field 

Dissipation (half-life)

23.7 days (CA)

6.1 days (VA)

< 1 day (ID)

< 1 day (Ontario, Canada)

O

O O

N

CH3

H

H

H

H

H

O

O

O

O

O

O

O

O

O O

N

CH3

H

H

H

H

H

O

O

O

O

O

O

O
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< 1 day (Prince Edward Island, Canada)

Aquatic Field 

Dissipation(half-life)

< 1 day (GA)

1.3 days (IN)

BCF (non-edible) 53/103 (low dose/high dose) 330/430 (low dose/high dose)

BCF (edible) 11/43 (low dose/high dose) 104/214 (low dose/high dose)

BCF (whole fish) 46/86 (low dose/high dose) 344/348 (low dose/high dose)

Four major degradates were identified in spinetoram fate studies: N-demethyl-J, N-demethyl-L,

O-demethyl-175-J, and O-demethyl-175-L (see Appendix C for details). The registrant has 

submitted absorption studies for two major degradates (N-demethyl-J and N-demethyl-L)

detected in spinetoram assessments. Results suggest that N-demethyl-J and N-demethyl-L are 

classified as slightly mobile and hardy mobile, respectively (Table 5).

Table 5. Physical, chemical, and fate properties for two major degradates (N-demethyl-J 

and N-demethyl-L) detected in the fate studies for spinetoram J and spinetoram L

N-demethyl-J N-demethyl-L

Chemical Structure

Molecular Weight 

(g/mol)

734 746

Kd/Koc (loamy sand) 16/2062 34/4270

Kd/Koc (silt loam) 133/12127 340/30918

Kd/Koc (sandy loam) 32/4642 81/11559

Kd/Koc (loam) 8/1631 19/3718

Average Kd/Koc 47/5116 119/12616

Drinking Water Assessment 

Tier II models (SWCC and PRZM/GW) were used to estimate surface water and groundwater 

EDWCs, respectively, for the proposed uses of spinosad and spinetoram. A total residue method 

was used in estimating EDWCs. This is because the main ring structures in the transformation 

products which were tentatively characterized in the fate studies remain unchanged. For 

example, spinetoram-J has a molecular weight (MW) of 748g/mol whereas as its degradate (Ndemethyl-J) has a MW of 734, due to the loss of a small methyl group. In the modeling, EFED 

assumed all the total spinosad and spinetoram residues (fully or partially identified) are stable 

under the aqueous photolysis, aerobic soil metabolism, aerobic aquatic metabolism, and 

anaerobic aquatic metabolism settings. Table 6 lists the input parameters used in modeling. Due 

to the high adsorption of spinosad and spinetoram with soil, EDWCs in groundwater are 

negligible.

O

O O

N

H

CH3

H

H

H

H

H

O

O

O

O

O

O

O

O

O O

N

H

CH3

H

H

H

H

H

O

O

O

O

O

O

O
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Table 6. Summary of Input Parameters for Spinosad and Spinetoram in SWCC and 

PRZM/GW

The use of spinosad and spinetoram on coffee resulted in the highest surface water EDWCs in all 

the proposed uses, results are presented in Table 7 (see Appendix D). However, since much 

highest application rate on turf (i.e., 1.6 lb ai/A) in all proposed uses was modeled using FIRST

in the 2002 spinosad DWA and the highest application rate on turf (i.e., 0.454 lb ai/A) was

modeled using FIRST in the 2007 spinetoram DWA, in addition to the proposed new uses, 

EFED decided to use the recently released SWCC to generate EDWCs on the registered turf use. 

Although the peak EDWC for coffee is slightly higher than that for turf, since the only available 

scenario for coffee is from Puerto Rico, EFED decided not to consider that those values and 

recommended to use EDWCs from turf use in the current DWA. 

Due to the extremely high adsorption of spinosad and spinetoram with soil, even using 100-year 

weather records and all six available scenario (DELMARVA_STD.SCN, 

FLCITRUS_STD.SCN, FLPOTATO_STD.SCN, GACOASTAL_STD.SCN, 

NCCOASTAL_STD.SCN, WISANDS_STD.SCN) in PRZM-GW simulation, PostBreakthrough Mean Concentration (PBT) and Simulation Average Breakthrough Time (BT) 

were not achieved (See Appendix E for further details). Although the use on coffee resulted in 

the highest groundwater EDWCs in all proposed uses, these values are below detection limits 

(Table 8). 

Input Parameter Spinosad Spinetoram

Hydrolysis Stable Stable

Aqueous Photolysis Stable Stable

Aerobic Soil Metabolism Stable Stable

Aerobic Aquatic Metabolism Stable Stable

Anaerobic Aquatic Metabolism Stable Stable

Koc 11,543 L/kg 12,511 L/kg

Vapor Pressure 2.4x 10 -10 torr 1.6x 10 -7 torr

Water Solubility 87.4 ppm 11.3 ppm

Molecular Weight (g/mol) 734 760

Application Method Aerial Aerial
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Table 7. Surface Water EDWCs from the Proposed Crop Uses and the Registered Turf 

Use of Spinosad and Spinetoram.

Table 8. Groundwater EDWCs from the Proposed Crop Uses of Spinosad and Spinetoram.

Coffee

ChemicalID Scenario ID Peak(ppb) PBT Avg(ppb) SimAvg BT(d)

spinosad DELMARVA_STD.SCN 1.42E-11 Incomplete 7.24E-13 Incomplete 0.0801

spinosad FLCITRUS_STD.SCN 0.000996 Incomplete 0.000117 Incomplete 0.0938

spinosad FLPOTATO_STD.SCN 1.37E-12 Incomplete 1.13E-13 Incomplete 0.0431

spinosad GACOASTAL_STD.SCN 0 Incomplete 0 Incomplete 0.0569

spinosad NCCOASTAL_STD.SCN 7.83E-09 Incomplete 4.66E-10 Incomplete 0.1008

spinosad WISANDS_STD.SCN 3.84E-18 Incomplete 1.65E-19 Incomplete 0.0698

Berry

ChemicalID Scenario ID Peak(ppb) PBT Avg(ppb) SimAvg BT(d)

spinosad DELMARVA_STD.SCN 1.35E-11 Incomplete 6.90E-13 Incomplete 0.0801

spinosad FLCITRUS_STD.SCN 0.00094 Incomplete 0.000111 Incomplete 0.0938

spinosad FLPOTATO_STD.SCN 1.29E-12 Incomplete 1.06E-13 Incomplete 0.0431

spinosad GACOASTAL_STD.SCN 0 Incomplete 0 Incomplete 0.0569

Crop (Registration 

Status)

Estimated Environmental 

Concentrations (ppb) Spinosad Spinetoram 

Coffee (proposed) Peak (1-in-10 yr) 13.8 9.4

365-day Avg (1-in-10 yr) 7.7 5.9

Entire Simulation Mean 5.7 4.6

Berry (proposed) Peak (1-in-10 yr) 6.9 4.4

365-day Avg (1-in-10 yr) 5.7 3.6

Entire Simulation Mean 3.4 2.0

Bulb Vegetables 

(proposed)

Peak (1-in-10 yr) 9.1 4.0

365-day Avg (1-in-10 yr) 8.0 3.5

Entire Simulation Mean 4.6 2.0

Cottonseed 

(proposed)

Peak (1-in-10 yr) 7.0 2.8

365-day Avg (1-in-10 yr) 3.5 2.3

Entire Simulation Mean 2.6 1.7

Cabbage 

(proposed)

Peak (1-in-10 yr) 13.0 7.3

365-day Avg (1-in-10 yr) 6.1 3.4

Entire Simulation Mean 5.1 2.8

Turf (registered) Peak (1-in-10 yr) 25.0 8.6

365-day Avg (1-in-10 yr) 21.7 5.9

Entire Simulation Mean 14.2 3.8
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spinosad NCCOASTAL_STD.SCN 7.32E-09 Incomplete 4.35E-10 Incomplete 0.1008

spinosad WISANDS_STD.SCN 3.60E-18 Incomplete 1.55E-19 Incomplete 0.0698

Bulb 

Vegetables

ChemicalID Scenario ID Peak(ppb) PBT Avg(ppb) SimAvg BT(d)

spinosad DELMARVA_STD.SCN 1.35E-11 Incomplete 6.90E-13 Incomplete 0.0801

spinosad FLCITRUS_STD.SCN 9.40E-04 Incomplete 1.11E-04 Incomplete 0.0938

spinosad FLPOTATO_STD.SCN 1.29E-12 Incomplete 1.06E-13 Incomplete 0.0431

spinosad GACOASTAL_STD.SCN 0.00E+00 Incomplete 0.00E+00 Incomplete 0.0569

spinosad NCCOASTAL_STD.SCN 7.32E-09 Incomplete 4.35E-10 Incomplete 0.1008

spinosad WISANDS_STD.SCN 3.60E-18 Incomplete 1.55E-19 Incomplete 0.0698

Cottonseed

ChemicalID Scenario ID Peak(ppb) PBT Avg(ppb) SimAvg BT(d)

spinosad DELMARVA_STD.SCN 1.32E-11 Incomplete 6.74E-13 Incomplete 0.0801

spinosad FLCITRUS_STD.SCN 0.000944 Incomplete 0.000111 Incomplete 0.0938

spinosad FLPOTATO_STD.SCN 1.30E-12 Incomplete 1.07E-13 Incomplete 0.0431

spinosad GACOASTAL_STD.SCN 0 Incomplete 0 Incomplete 0.0569

spinosad NCCOASTAL_STD.SCN 7.52E-09 Incomplete 4.48E-10 Incomplete 0.1008

spinosad WISANDS_STD.SCN 3.71E-18 Incomplete 1.60E-19 Incomplete 0.0698

Cabbage

ChemicalID Scenario ID Peak(ppb) PBT Avg(ppb) SimAvg BT(d)

spinosad DELMARVA_STD.SCN 1.39E-11 Incomplete 7.10E-13 Incomplete 0.0801

spinosad FLCITRUS_STD.SCN 0.000998 Incomplete 0.000118 Incomplete 0.0938

spinosad FLPOTATO_STD.SCN 1.38E-12 Incomplete 1.14E-13 Incomplete 0.0431

spinosad GACOASTAL_STD.SCN 0 Incomplete 0 Incomplete 0.0569

spinosad NCCOASTAL_STD.SCN 7.94E-09 Incomplete 4.73E-10 Incomplete 0.1008

spinosad WISANDS_STD.SCN 3.91E-18 Incomplete 1.68E-19 Incomplete 0.0698

Coffee

ChemicalID Scenario ID Peak(ppb) PBT Avg(ppb) SimAvg BT(d)

spinetoram DELMARVA_STD.SCN 2.17E-12 Incomplete 1.09E-13 Incomplete 0.0739

spinetoram FLCITRUS_STD.SCN 0.000328 Incomplete 3.81E-05 Incomplete 0.0865

spinetoram FLPOTATO_STD.SCN 2.34E-13 Incomplete 1.92E-14 Incomplete 0.0398

spinetoram GACOASTAL_STD.SCN 0 Incomplete 0 Incomplete 0.0525

spinetoram NCCOASTAL_STD.SCN 1.21E-09 Incomplete 7.11E-11 Incomplete 0.0931

spinetoram WISANDS_STD.SCN 3.12E-19 Incomplete 1.30E-20 Incomplete 0.0645

Berry

ChemicalID Scenario ID Peak(ppb) PBT Avg(ppb) SimAvg BT(d)
Page | 12

spinetoram DELMARVA_STD.SCN 2.06E-12 Incomplete 1.03E-13 Incomplete 0.0739

spinetoram FLCITRUS_STD.SCN 0.000327 Incomplete 3.80E-05 Incomplete 0.0865

spinetoram FLPOTATO_STD.SCN 2.35E-13 Incomplete 1.93E-14 Incomplete 0.0398

spinetoram GACOASTAL_STD.SCN 0 Incomplete 0 Incomplete 0.0525

spinetoram NCCOASTAL_STD.SCN 1.24E-09 Incomplete 7.28E-11 Incomplete 0.0931

spinetoram WISANDS_STD.SCN 3.20E-19 Incomplete 1.34E-20 Incomplete 0.0645

Bulb 

Vegetables

ChemicalID Scenario ID Peak(ppb) PBT Avg(ppb) SimAvg BT(d)

spinetoram DELMARVA_STD.SCN 1.43E-12 Incomplete 7.14E-14 Incomplete 0.0739

spinetoram FLCITRUS_STD.SCN 2.26E-04 Incomplete 2.63E-05 Incomplete 0.0865

spinetoram FLPOTATO_STD.SCN 1.62E-13 Incomplete 1.33E-14 Incomplete 0.0398

spinetoram GACOASTAL_STD.SCN 0.00E+00 Incomplete 0.00E+00 Incomplete 0.0525

spinetoram NCCOASTAL_STD.SCN 8.54E-10 Incomplete 5.03E-11 Incomplete 0.0931

spinetoram WISANDS_STD.SCN 2.11E-19 Incomplete 7.90E-21 Incomplete 0.0645

Cottonseed

ChemicalID Scenario ID Peak(ppb) PBT Avg(ppb) SimAvg BT(d)

spinetoram DELMARVA_STD.SCN 1.86E-12 Incomplete 9.36E-14 Incomplete 0.0739

spinetoram FLCITRUS_STD.SCN 0.000288 Incomplete 3.35E-05 Incomplete 0.0865

spinetoram FLPOTATO_STD.SCN 2.06E-13 Incomplete 1.69E-14 Incomplete 0.0398

spinetoram GACOASTAL_STD.SCN 0 Incomplete 0 Incomplete 0.0525

spinetoram NCCOASTAL_STD.SCN 1.08E-09 Incomplete 6.34E-11 Incomplete 0.0931

spinetoram WISANDS_STD.SCN 2.71E-19 Incomplete 1.06E-20 Incomplete 0.0645

Cabbage

ChemicalID Scenario ID Peak(ppb) PBT Avg(ppb) SimAvg

spinetoram DELMARVA_STD.SCN 1.86E-12 Incomplete 9.36E-14 Incomplete 0.0739

spinetoram FLCITRUS_STD.SCN 0.000288 Incomplete 3.35E-05 Incomplete 0.0865

spinetoram FLPOTATO_STD.SCN 2.06E-13 Incomplete 1.69E-14 Incomplete 0.0398

spinetoram GACOASTAL_STD.SCN 0 Incomplete 0 Incomplete 0.0525

spinetoram NCCOASTAL_STD.SCN 1.08E-09 Incomplete 6.34E-11 Incomplete 0.0931

spinetoram WISANDS_STD.SCN 2.71E-19 Incomplete 1.06E-20 Incomplete 0.0645
Page | 13

Appendix A: Environmental Fate Properties of Spinosad 

Degradation and Metabolism

Spinosad and Spinosad A and spinosad D were relatively stable in pH 5, 7, and 9 sterile aqueous 

buffer solutions that were incubated in the dark at 25°C (MRID 43507301). 

In sterile buffered (pH 7) solutions, spinosad A and spinosad D phototransformed with half-lives 

of 0.8-0.9 days (MRID 43507302). The β-isomers of the 13,14-dihydro of the pseudoaglycone of 

spinosad A and of spinosad D were detected at a maximum of 20.2-24.9% of the applied at 48 

hours (study termination). In alkaline (pH 9.2) pond water, spinosad A and spinosad D 

phototransformed rapidly with half-lives of 0.54-0.55 days. On soil, spinosad A and spinosad D 

had photodegradation half-life of 8.68-9.71 days (MRIDs 44597733 and 43507303). The only 

transformation present at >5 % of the applied was N-demethyl-A, which reached 14.8% of the 

applied at 18 days post-treatment. These studies were not long enough to determine the fate of 

the degradates.

In aerobic silt loam soil, spinosad A and spinosad D converted to degradates with initial halflives of 17.3 and 14.5 days, respectively (MRIDs 44597733 and 43507303). Spinosad A 

converted to degradates with a half-life of 9.4 days in sandy loam soil incubated under similar 

conditions. Approximately 75-90% of the applied spinosad converted to degradates by 28 days. 

The major degradate of spinosad A was N-demethyl-A, which accumulated to a maximum 51-

61% of the applied at 14-28 days post-treatment, then decreased to 12.27-21.72% at 9 months 

and 2.77-5.96% at 1 year. The major degradate of spinosad D was N-demethyl–D, which 

accumulated to a maximum 68% of the applied at 28 days post-treatment and approximately

50% at 6 months. Several minor degradates, each less than 10% of the applied, were isolated but 

not conclusively identified. The anaerobic soil metabolism of spinosad could not be evaluated 

because no studies were submitted.

In anaerobic flooded clay sediment, spinosad A and spinosad D converted to degradates with 

half-lives of 161 and 250 days (MRID 43507305). By 7 days post-treatment, >90% of the 

applied radioactivity was associated with the sediment fraction. Three major degradates of 

spinosad A, each present at a maximum 8-12% of the applied were identified: N-demethyl-A, 

reversepseudoaglycone (806643), and ketoreversepseudoaglycone (814426). One major 

degradate of spinosad D, N-demethyl-D, was present at a maximum 6.5% of the applied. 

The fate of spinosad under the aerobic aquatic environment is unknown. This is because the 

submitted study (MRID 46642701) is classified as unacceptable and is scientifically invalid 

because significant variability in the results between sampling intervals and between systems at 

the same sampling interval prevents any confident interpretation of the study results. Because of 

poor results in the initial experiment, the data presented in this MRID are a compilation of 

analyses of selected test systems from four separate experimental sets for each test substance and 

system. In addition, degradates comprising 10% of the applied may have been present and not 

identified.
Page | 14

Soil sorption and mobility

The mobility of spinosad A, at nominal concentrations of 0.04-5.0 μg/mL, was investigated in 

sand, loamy sand, sandy loam, silt loam, and clay loam soils (MRID 43507306). Koc values 

were 2,862, 831, 4,237, 134,583, and 21,938, respectively. Freundlich Kdes values for both 

desorption phases for the sand, loamy sand, sandy loam, and silt loam soils were 8.4-9.2, 6.6-8.2, 

27-30, 288-357 and 292-296, respectively; corresponding 1/n values ranged from 0.826-0.921. 

Adsorption coefficients for spinosad A were used in modeling.

The mobility of N-demethyl-A, the major degradate of spinosad A, was investigated at 0.05-5.0 

μg/mL in sand, loamy sand, sandy loam, and silt loam soils (MRID 43816602). Koc values were 

2,138, 662, 2,881, and 74,583, respectively. Freundlich Kdes values for both desorption phases 

for the sand, loamy sand, sandy loam, and silt loam soils were 6.3-6.5, 5.3-6.3, 19-20, and 171-

179, respectively; corresponding 1/n values ranged from 0.775-0.880. 

Spinosad A and D are not volatile; vapor pressures (25°C) are 2.0 to 3.0 x 10-11 kPa. CO2 was 

the only volatile compound detected in metabolism studies.

Field dissipation

Radioactive spinosad A, formulated as an emulsifiable concentrate, degraded with half-lives of 

0.5 days in bareground plots of silt loam soil in Mississippi and 0.3 days in loam soil in 

California (MRID 43714301). Approximately 2-3% remained after 3-5 days. The study did not 

include those major degradates detected in the laboratory fate studies as analytes. Spinosad A 

and its degradates were not detected below the 6-inch soil depth. Unextracted [14C] residues 

increased to a maximum of 34-58% by 38-40 days. At the Mississippi site, total radioactivity in 

the runoff accounted for 3.1% of the applied radioactivity. 

Pond water (pH 7.6, ca. surface area 2.2 m2, depth 47.5-50 cm) and clay loam sediment (ca. 

depth 5.5-6 cm) maintained in outdoor tanks were treated once with a broadcast-spray

application of the suspension concentrate at 100 g/ha to the water surface (MRID 43848803). 

Spinosad (including spinosad A and D) dissipated rapidly from the water with a calculated halflife of 1.5 days, and total spinosad residues dissipated from the water with a calculated half-life 

of 4 days. In the water, the degradates N-demethyl-A and N-demethyl-D were detected at 

maximums of 2.3 ppb (8 hours) and 3.6 ppb (0 hour), respectively, and were <0.5 ppb at 15 days. 

In the sediment, spinosad A was detected at a maximum average 14.9 ppb at 4 days and was 14.3 

ppb at 35 days. N-demethyl-A was detected at a maximum average 11.1 at 15 days and was ≤9.4 

ppb at 35 days. Spinosad D was ≤4.2 ppb and N-demethyl-D was not detected (LOD 11.3 ppb) at 

any interval in the sediment. Total spinosad residues in the water had an observed half-life of <1 

days. Spinosad residues (parent and its degradates) in the sediment reached a maximum 

concentration at 8 days post-treatment and had decreased by approximately 25% by 35 days. 

These field studies need to be re-evaluated because the half-lives may reflect the transformation 

of the parent to other degradates similar to the parent. Also the dissipation half-lives reflect the 

movement of the parent and degradates from one media to another and do not show degradation 

of the product.
Page | 15

Accumulation

[

14C]Spinosad A and D accumulated in rainbow trout held under laboratory flow-through 

conditions for up to 28 days (MRIDs 44537734 and 43557601). In the high concentration 

experiments (19.0 ng/L for spinosad A and 33.0 ng/L for spinosad D), maximum BCFs for 

spinosad A were 28.8 mL/g (at Day 28) for the nonedible tissue, 7.5 mL/g (at Day 25) for the 

edible tissue, and 21.1 mL/g (at Day 7) for the whole fish tissue; and for spinosad D were 42 

mL/g (at Day 11) for the nonedible tissue, 20.5 mL/g (at Day 11) for the edible tissue, and 41.9 

mL/g (at Day 7) for the whole fish tissue. Registrant-calculated BCFs for total [14C]residues 

were 103-152, 16-47, and 84-115 mL/g for the nonedible, edible, and whole fish tissues, 

respectively. 

In fish exposed to spinosad A, parent accounted for 68.34% of the HPLC distribution in whole 

fish extracts on exposure day 1, and ≤29.74% at later sampling intervals. Spinosad J was present 

at 125 ng/g in day 25 nonedible extracts and day 28 whole fish extracts; all other degradates 

were each <50 ng/g. In fish exposed to spinosad D, parent accounted for 83.43% of the HPLC 

distribution in whole fish tissue on exposure day 1, 48.80% on day 7, 42.19% on day 14, and 

35.44% on day 28. In the whole fish tissues, 15-Pk4 and 20-Pk4 [N-monomethylated, Odemethylated Spinosad Factor D] was a maximum of 134 ng/g; 15-Pk6 and 20-Pk6 [Nmonomethylated, O-demethylated Spinosad Factor D] was a maximum of 230 ng/g; Spinosad 

Factor L was a maximum of 229 ng/g; Spinosad Factor O was a maximum of 173 ng/g; and Ndemethyl-D was a maximum of 544 ng/g. All other degradates were <50 ng/g.

Spinosad (i.e., spinosad A and D) has a relatively low bioconcentration factor (BCF’s of the 

parent ranged from 8-20,X, 29-42X, and 21-42X for muscle, viscera, and whole fish, 

respectively), and a relatively rapid rate of depuration (half-life of about one day). These factors 

generally would prevent substantial bioconcentration of the material in the food web.
Page | 16

Appendix B: Environmental Fate Properties of Spinetoram

Degradation and Metabolism

The total residue method was used in estimating EECs in the ecological risk assessment. This is 

because the main ring structures in the degradates, which were tentatively identified or partially 

characterized in the fate studies, are essentially the same as the parent. In the modeling of 

spinetoram, EFED used the same toxicity for spinetoram J and spinetoram L and the persistence 

of the spinetoram residues (including parent and its degradates) under the aqueous photolysis, 

soil photolysis, aerobic soil metabolism, and anaerobic aquatic metabolism conditions. 

Spinetoram is expected to dissipate relatively rapidly under most environmentally relevant 

conditions with the apparent primary route of dissipation being via photolysis in water and soil, 

and aerobic metabolism in soil. However, it should be noted that most of the degradates detected 

in the laboratory studies still contain the major complicated ring structures. Parent spinetoram is 

stable to hydrolysis and persistent under aerobic and anaerobic aquatic environments in the 

laboratory, but dissipates rapidly in terrestrial and aquatic field environments. Also, leaching and 

migration into sediments under field conditions was not significant. 

Spinetoram was stable to hydrolysis at pH 5, and 7, and had <10% decline over 30 days at pH 9

(MRID 46695023). The photodegradation half-life in pH 7 buffer solutions for spinetoram J and 

spinetoram L was 12 and 5 hours, respectively (MRID 46695022). In moist loam soil, the 

photodegradation half-life for spinetoram J and spinetoram L was 27.4 and 9.4 days, respectively

(MRID 46695024). In VA loam, MS loam, sandy loam and silt loam soils, spinetoram J 

dissipated with nonlinear half-lives of 9, 23, 27 and 31, respectively; spinetoram L dissipated 

with nonlinear half-lives of 3, 19, 18 and 15 days, respectively (MRID 46695025). 

In aerobic aquatic conditions, the half-life in water could not be determined as dissipation from 

the water phase was very rapid, with both test substances rapidly associating with the sediment; 

spinetoram J and spinetoram L degraded in the sediment with nonlinear half-lives of 126 and 114 

days, respectively; and from the total system with half-lives of 116 and 124 days, respectively

(MRID 46695027). In anaerobic aquatic conditions, both test substances again associated 

rapidly with the sediment; spinetoram J and spinetoram L degraded in the sediment with halflives of 408 and 1,386 days, respectively; and in the total system with half-lives of 385 and 1,386 

days, respectively (MRID 46695026). 

The proposed transformation pathway involves spinetoram J and spinetoram L degrading due to 

photolysis and/or microbial metabolism by de-methylation to yield N-demethyl-J and Ndemethyl-L, respectively (O-demethyl-J and O-demethyl-L, respectively, under anaerobic 

aquatic conditions), and several minor unidentified compounds. Further degradation occurs to 

form numerous increasingly polar compounds over time, and ultimately mineralization to CO2.

Soil Sorption and Mobility
Page | 17

Spinetoram is expected to be generally immobile in soil (MRID 46695028). Spinetoram J and 

spinetoram-L were classified as having low mobility to being immobile according to McCall’s 

Relative Mobility classification system in loamy sand, silt loam, sandy loam and loam soils from 

the U.S., with a Koc of 1800 to 43873 mL/g. 

Field Dissipation

Under terrestrial field conditions, the half-life for spinetoram (-J + -L) in loam and sandy loam 

soil was 23.7 days and 6.1 days, respectively, while the observed half-life was ≤1 day in each 

soil (MRIDs 46695029 and 47072901). Spinetoram was not detected below the 0-15 cm soil 

depth at any sampling intervals. Under aquatic field conditions, spinetoram dissipated very

quickly in water (MRID 46695030), with no partitioning of residues into the sediment. Total 

spinetoram residues (spinetoram J + spinetoram L) dissipated in the water with half-lives of 18.1 

to 20.4 hours. No residues of spinetoram J or spinetoram L were detected in any pre- or postapplication sediment samples.

Accumulation

Since the octanol/water partitioning coefficients for spinetoram J and spinetoram L are high 

(12,303 and 30,903, respectively), these two components are expected to bioconcentrate in fish. 

In rainbow trout exposed to spinetoram J at 17.3 ng/mL, the bioconcentration factors (BCFs) for 

edible tissue, nonedible tissue, and whole fish were 11, 53, and 46 mL/g, respectively (MRID 

46695128). After 1 day of depuration, total [14C] residues in the whole fish had decreased by 

28.2%. After 21 days of depuration, total [14C] residues had decreased by 88.7%. The 

elimination half-lives for [14C] residues in edible tissue, nonedible tissue, and whole fish were 

2.3, and 4.1, and 4.6 days, respectively. In rainbow trout exposed to spinetoram L at 22.3 ng/mL,

the BCFs for edible tissue, nonedible tissue, and whole fish were 104, 330, and 344 mL/g, 

respectively (MRID 46695129). After 1 day of depuration, total [14C] residues in the whole fish 

had steadily decreased by 9.5%. After 14 days of depuration, total [14C] residues had decreased 

by 87.4%. The elimination half-lives for [14C] residues in whole fish, edible tissue, and nonedible 

tissue were 4.5, 3.9, and 4.1 days, respectively. Spinetoram J and spinetoram L rapidly

metabolized, yielding 2-4 more polar degradates; correspondingly, N-demethyl-J and Ndemethyl-L were positively identified, along with 3’-O-deethyl-XDE-175-L.
Page | 18

Appendix C: Summary of Degradates in the Environmental Fate Studies for Spinetoram

Degradate (Name)

Maximum Degradate Concentration (% of applied) and Time (days) to 

Maximum Concentration in Study: Degradates Analyzed in Study:

Hydrolysis

(161-1)

Aqueous

Photo.

(161-2)

Soil 

Photo.

(161-3)

Aerobic 

Soil

(162-1)

Anaerobic

Aquatic

(162-3)

Aerobic 

Aquatic

(162-4)

Field Diss.

(164-1)

Aquatic 

Diss.

(164-2)

Fish Study 

(165-4)

N-demethyl-J

6.7% @ 30 

d

6.6% @ 

0.33 d

Not 

Analyzed

68.1% @ 

125 d

Not 

Analyzed

8.9% @ 16 

d

0.0590 

mg/kg @ 

26 d

0.373 μg/L 

@ 1 h

7.141 

mg/kg @ 

21 d 

N-demethyl-L

11.9% @ 

30 d

12.2% @ 

0.17 d

Not 

Analyzed

41.0% @ 32 

d 

Not 

Analyzed

9.6% @ 21 

d

(0.0039 

mg/kg @ 0 

d) 2

0.060 μg/L 

@ 0.5 h 

Not 

Reported1

N-demethyl-J +

N-demethyl-L

Not 

Analyzed

Not 

Analyzed

Not 

Analyzed

Not 

Analyzed

Not 

Analyzed

Not 

Analyzed

Not 

Analyzed

0.410 ug/L 

@ 6 h1

Not 

Analyzed

O-demethyl-175-J

Not 

Analyzed

Not 

Analyzed

Not 

Analyzed

Not 

Analyzed

26.7% @ 

365 d

2.8% @ 30 

d

Not 

Analyzed

Not 

Analyzed

Not 

Analyzed

O-demethyl-175-L

Not 

Analyzed

Not 

Analyzed

Not 

Analyzed

Not 

Analyzed

10.4% @ 

365 d

Not 

Analyzed

Not 

Analyzed

Not 

Analyzed

Not 

Analyzed

3’-O-deethyl-175-J

Not 

Analyzed

Not 

Detected

Not 

Analyzed

Not 

Analyzed

Not 

Analyzed

Not 

Analyzed

Not 

Analyzed

Not 

Analyzed

Not 

Detected

3’-O-deethyl-175-L

Not 

Analyzed

Not 

Analyzed

Not 

Analyzed

Not 

Analyzed

Not 

Analyzed

Not 

Analyzed

Not 

Analyzed

Not 

Analyzed

Not 

Reported1

N-demethyl-175-L + 

3’-O-deethyl-175-L

Not 

Analyzed

Not 

Analyzed

Not 

Analyzed

Not 

Analyzed

Not 

Analyzed

Not 

Analyzed

Not 

Analyzed

Not 

Analyzed

16.034 

mg/kg @ 

28 d

N-formyl-175-J

Not 

Analyzed

Not 

Detected

Not 

Analyzed

Not 

Detected

Not 

Analyzed

Not 

Analyzed

Not 

Analyzed

Not 

Analyzed

Not 

Detected

Aglycone-175-J

Not 

Analyzed

Not 

Detected

Not 

Analyzed

Not 

Detected

Not 

Analyzed

Not 

Analyzed

Not 

Analyzed

Not 

Analyzed

Not 

Detected

C9-pseudoaglycone-175-J

Not 

Analyzed

Not 

Detected

Not 

Analyzed

Not 

Detected

Not 

Analyzed

Not 

Analyzed

Not 

Analyzed

Not 

Analyzed

Not 

Detected

C9-pseudoaglycone-175-L

Not 

Analyzed

Not 

Detected

Not 

Analyzed

Not 

Detected

Not 

Analyzed

Not 

Analyzed

Not 

Analyzed

Not 

Analyzed

Not 

Detected

C9-ketopseudoaglycone-175-

J

Not 

Analyzed

Not 

Analyzed

Not 

Analyzed

Not 

Analyzed

Not 

Analyzed

Not 

Analyzed

Not 

Analyzed

Not 

Analyzed

Not 

Detected

C9-ketopseudoaglycone-175- Not Not Not Not Not Not Not Not Not 
Page | 19

L Analyzed Analyzed Analyzed Analyzed Analyzed Analyzed Analyzed Analyzed Detected

C17-pseudoaglycone-175-J

Not 

Analyzed

Not 

Detected

Not 

Analyzed

Not 

Detected

Not 

Analyzed

Not 

Analyzed

Not 

Analyzed

Not 

Analyzed

Not 

Detected

C17-pseudoaglycone-175-L

Not 

Analyzed

Not 

Detected

Not 

Analyzed

Not 

Detected

Not 

Analyzed

Not 

Analyzed

Not 

Analyzed

Not 

Analyzed

Not 

Detected

Carbon dioxide Not 

Analyzed

Not 

Analyzed

3.5% @ 

18 d 

spinetoram

J:

from 5.0% 

@ 366 d 

(CA) to 

35.2% @ 

276 d (VA)

spinetoramL:

From

12.50% @ 

276 d (CA) 

to 

36.2% @ 

365 d (VA)

0.2% @ 90 

d

0.7% @ 2 d Not 

Analyzed

Not 

Analyzed

Not 

Analyzed

Nonextractable residues Not 

Analyzed

Not 

Analyzed

15.6% @ 

18 d

37.9% @ 

276 d

12.1% @ 

365 d

11.0% @ 21 

d

Not 

Analyzed

Not 

Analyzed

Not 

Analyzed

1 Data from identified degradates reported as a combined number.

2 Maximum concentration was <LOQ.
Page | 20

Appendix D: Surface Water Modeling of Spinosad and USEPA Standard 

Reservoir 

Estimated Environmental Concentrations for spinosad are presented in Table 1 for the USEPA 

standard reservoir with the FLturfSTD field scenario. A graphical presentation of the year-toyear 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 0.77% of spinosad applied to the field eventually reaches the 

water body. The main mechanism of transport from the field to the water body is by spray drift 

(63.7% of the total transport), followed by runoff (30.3%) and erosion (6.05%).

In the water body, pesticide dissipates with an effective water column half-life of 551.8 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 = 551.9 days) followed by

volatilization (4767521 days).

In the benthic region, pesticide is stable. The vast majority of the pesticide in the benthic region 

(99.92%) is sorbed to sediment rather than in the pore water.

Table 1. Estimated Environmental Concentrations (ppb) for spinosad.

Peak (1-in-10 yr) 25.0

4-day Avg (1-in-10 yr) 24.0

21-day Avg (1-in-10 yr) 23.3

60-day Avg (1-in-10 yr) 22.5

365-day Avg (1-in-10 yr) 21.7

Entire Simulation Mean 14.2

Table 2. Summary of Model Inputs for spinosad.

Scenario FLturfSTD

Cropped Area Fraction 1.0

Koc (ml/g) 11543

Water Half-Life (days) @ 25 °C 0

Benthic Half-Life (days) @ 25 °C 0

Photolysis Half-Life (days) @ 25 

°Lat

0

Hydrolysis Half-Life (days) 0

Soil Half-Life (days) @ 25 °C 0

Foliar Half-Life (days) 35
Page | 21

Molecular Wt 734

Vapor Pressure (torr) 0.00000001

Solubility (mg/l) 87.4

Table 3. Application Schedule for spinosad.

Date (Mon/Day) Type Amount (kg/ha) Eff. Drift

6/1 Foliar 0.448 0.95 0.16

6/8 Foliar 0.448 0.95 0.16

6/15 Foliar 0.448 0.95 0.16

6/22 Foliar 0.448 0.95 0.16

Figure 1. Yearly Peak Concentrations
Page | 22

Appendix E. Groundwater Analysis for spinosad and the Wisconsin Corn -

WI Central Sands Scenario

Estimated groundwater concentrations and breakthrough times for spinosad 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 spinosad and the Wisconsin Corn - WI Central Sands 

Scenario.

Peak Concentration (ppb) 3.84E-18

Post-Breakthrough Mean 

Concentration (ppb)

Incomplete

Entire Simulation Mean 

Concentration (ppb)

1.65E-19

Average Breakthrough 

Time (days)

Incomplete

Throughputs 0.06983208

Table 2. Chemical Properties for Groundwater Modeling of spinosad.

Koc (ml/g) 11543

Surface Soil Half Life (days) 0

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 spinosad. This application scheme was 

applied every year of the simulation.

Application Date

(Month/Day)

Application Method Application Rate

(kg/ha)

6/1 Above canopy application 0.089

6/6 Above canopy application 0.089

6/11 Above canopy application 0.089

6/16 Above canopy application 0.089
Page | 23

6/21 Above canopy application 0.089

6/26 Above canopy application 0.089

Figure 1. Aquifer Breakthrough Curve for spinosad and the Wisconsin Corn - WI Central 

Sands Scenario