UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON D.C., 20460 

MEMORANDUM 

DATE: 

THRU: 

March 4, 2013 

Dana Spatz, Chie:lC::::::::::::~.t 

Rosanna Louie-Juzwiak, RAPL 

Melissa Panger, Ph.D., Senior Bio s 

James Hetrick, Ph.D., Senior Advisor 

Environmental Risk Branch 3 

Environmental Fate and Effects Division (7507P) 

TO: Carissa Cyran, Chemical Review Manager 

Neil Anderson, Chief 

Risk Management and Implementation Branch 1 

Pesticide Re-evaluation Division (7508P) 

OFFICE OF 

CHEMICAL SAFETY AND 

POLLUTION PREVENTION 

The Environmental Fate and Effects Division (EFED) has completed the problem formulation 

for the ecological risk and drinking water exposure assessments to be conducted as part of the 

Registration Review of EPTC. This document is intended to provide an overview of what is 

currently known regarding the environmental fate and ecological effects associated with EPTC 

and its degradation products, and outlines uncertainties regarding attributes of the parent 

compound and its transformation products. It describes the preliminary ecological risk 

hypothesis and the processes that will be used during the completion of the ecological risk 

assessment in support of Registration Review. 

' 
2

1. INTRODUCTION 

EPTC is a pre-emergence (pre-plant) and early post-emergence thiocarbamate herbicide used to 

control the growth of germinating annual weeds, including broadleaves, grasses, and sedges. Due 

to its volatility, EPTC must be mechanically incorporated, injected in the subsurface of the soil, 

applied in irrigation water, or be watered-in after application. Thiocarbamates inhibit both cell 

division and elongation, fatty acid and lipid biosynthesis, protein synthesis, and may alter plant 

hormonal distribution within a plant. EPTC exerts its herbicidal action through inhibition of 

cuticle formation at the early stages of seedling growth which inhibits germination and seedling 

development. 

EPTC is used throughout the United States in agricultural production for a wide variety of food 

and non-food crops. The registered uses are alfalfa, almond, beans (dried, castor, snap or 

succulent), broccoli, carrot, citrus, clover, conifers (seed orchard), corn (field, pop, silage, sweet, 

unspecified), cotton, grapefruit (bearing, nonbearing), fallow, lemon (bearing, nonbearing), 

lespedeza, lettuce, orange (bearing, nonbearing), ornamentals (ground cover, herbaceous plants, 

seed orchard, woody shrubs and vines, trees), potato (white/Irish), safflower, sugar beets, 

sunflower, sweet potato, tangerine, tomato, trefoil and walnut. The label application rates range 

from 1.5 to 14.9 pounds of active ingredient per acre (lb a.i./A; Table 2). The uses with the 

greatest total annual pounds of EPTC used include alfalfa, potato, sugar beet, safflower, beans 

(all types), corn, carrots, and almonds. 

EPTC is formulated either as an emulsifiable concentrate or a granular. Application equipment 

and methods for EPTC include ground application, soil band treatment, soil broadcast, direct 

spray, chemigation, flood treatment, and aerial application. 

The structure of EPTC, as well as the chemical name and other identifiers are provided in Table 

1. 

Table 1. EPTC Chemical Identifiers

Parameter Identifier 

Chemical Structure H3C S N

CH3

CH3

O

Chemical Name Carbamothioic acid 

N,N-dipropyl-, S-ethyl ester 

SMILES C(C)CN(CCC)C(SCC)=O 

CAS Number 759-94-4 
3

In addition to the technical products (Reg. No. 10163-282, and 19713-557), there are 13 end-use 

products that contain EPTC: three of the products are co-formulated with an additional active 

ingredient, Acetochlor: 2-chloro-2'-methyl-6'-ethyl-N-ethoxymethylacetanilide (PC code 

121601). A summary of all the EPTC formulated products is provided in Table 2. 

Table 2. EPTC Formulated Products

Reg # Product name Active Ingredient(s) 

100-1083 DOUBLEPLAY SELECTIVE HERBICIDE 

67.8 % EPTC; 

16.9 % Acetochlor: 2-chloro-2'-methyl-6'-

ethyl-N-ethoxymethylacetanilide 

10163-281 EPTAM 20-G GRANULES 20 % EPTC 

10163-283 EPTAM 7-E SELECTIVE HERBICIDE 87.8 % EPTC 

10163-284 ERADICANE 6.7-E 82.6 % EPTC 

10163-285 GOWAN EPTAM/ACETOCHLOR 

67.8%/16.9% EC HERBICIDE 

67.8 % EPTC; 

16.9 % Acetochlor: 2-chloro-2'-methyl-6'-

ethyl-N-ethoxymethylacetanilide 

19713-101 DREXEL EPTC-7EC 87.8 % EPTC 

19713-561 EPTC 7EC 87.8 % EPTC 

19713-562 RAZENCANE 6.7E 82.6 % EPTC 

19713-564 EPTAM 7-E SELECTIVE HERBICIDE 87.8 % EPTC 

19713-568 DREXEL POWER PLAY HERBICIDE 

67.8 % EPTC; 

16.9 % Acetochlor: 2-chloro-2'-methyl-6'-

ethyl-N-ethoxymethylacetanilide 

AZ060004 EPTAM 7-E SELECTIVE HERBICIDE 87.8 % EPTC 

CA080024 EPTAM 7-E SELECTIVE HERBICIDE 87.8 % EPTC 

FL070007 EPTAM 7-E SELECTIVE HERBICIDE 87.8 % EPTC 

Based on the usage report prepared by OPP’s Biological and Economic Analysis Division, 

private market pesticide usage data show EPTC's annual (2006 - 2011) agricultural usage 

averaged 1.6 million pounds of active ingredient treating an average of 592,000 acres.1

From 2006-2011, potatoes (47%), dry beans/peas (32%), and beans (11%) accounted for the 

largest percentages of usage in terms of total pounds of active ingredient applied. For the same 

period of time (2006-2011), potatoes (40%), dry beans (38%), and beans (11%) accounted for 

the largest percentages of total area treated. Relative proportions indicate that the application rate 

for potatoes is somewhat higher than the overall average rate while that for dry beans and peas is 

somewhat lower. A summary of the maximum rates for currently registered uses of EPTC is 

provided in Appendix D. 

2. PREVIOUS RISK ASSESSMENTS 

Recent assessments include a Section 3 New Uses assessment on sunflower, transplanted 

watermelon, and citrus in 2012 (D397779), a Section 3 New Use assessment for newly planted 

and established grass conducted in 2010 (D371023) and ecological risk assessments on the 

potential direct and indirect effects to the California red-legged frog (CRLF) and Delta smelt 

 

1

 BEAD Chemical Profile for Registration Review: S-ethyl dipropylthiocarbamate 

or EPTC (041401), dated December 5, 2012. 
4

(DS) and potential modification to designated critical habitat from uses of EPTC, dated 20082

and 20103

 (see Table 3). Prior to these risk assessments, a risk assessment for all EPTC uses was 

conducted in support of the EPTC Reregistration Eligibility Decision (RED, 19994). Citrus and 

sunflower uses were previously assessed as part of the latter three assessments. They were being 

re-assessed in 2012 because proposed label changes were national in scope and the 2008 and 

2010 assessments only assessed risks for citrus and sunflower production in California. These 

uses were also revaluated because risk assessment exposure models have been updated since the 

last nation-wide assessment of these uses in 1999. EFED evaluated these assessments for EPTC 

in association with the current toxicity, exposure, and usage information to determine if 

sufficient data are available and if further updates are needed to support registration review. 

Table 3. Summary of Past Risk Assessments on EPTC. 

DP 

Barcode Year Use site Target Pest Action 

n/a 1999 

alfalfa, almonds, beans, birdsfoot trefoil, citrus, clover, corn (field and 

sweet), cotton, garden beets, lespedeza, potatoes, safflower, sunflower, 

sugar beets, sweet potatoes, tomatoes, walnuts, citrus nursery stock, 

non-bearing orange orchards, non-bearing grapefruit, evergreens, 

deciduous trees, scrubs, pine seedling nurseries, ornamentals (plant, 

flowers), parks, ornamentals, shade trees, evergreens, flower gardens, 

aquatics (drainage systems), turf (ornamental), golf course sand traps. 

Broadleaf 

and grass 

weeds 

Reregistr

ation 

Eligibilit

y 

Decision 

(RED) 

n/a 2008 

California: alfalfa, clover, lespedeza, birdsfoot trefoil, almonds, 

walnut, citrus, grapefruit, lemon, orange, tangerine, broccoli, cabbage, 

cauliflower, field corn, silage, popcorn, sweet corn, sunflower, cotton, 

conifers (seed orchards), pine seed orchards, lettuce, herbaceous 

ornamentals, woody shrubs and vines, white/Irish potato, sweet potato, 

beans, carrot, castor bean, snap beans, sugar beet, tomato, safflower, 

agricultural fallow/idle land. 

Broadleaf 

and grass 

weeds 

Californi

a RedLegged 

Frog 

ESA 

Litigation 

n/a 2010 

California: alfalfa, almond, beans (dried, castor, snap or succulent), 

broccoli, cabbage, carrot, citrus, clover, conifers (seed orchard), corn 

(field, pop, silage, sweet, unspecified), cotton, grapefruit (bearing, 

nonbearing), lemon (bearing, nonbearing), lespedeza, lettuce, orange 

(bearing, nonbearing), ornamentals (ground cover, herbaceous plants, 

seed orchard, woody shrubs), potato (white/Irish), safflower, sugar 

beets, sunflower, sweet potato, tangerine, tomato, trefoil, walnut. 

Broadleaf 

and grass 

weeds 

Delta 

Smelt 

ESA 

Litigation 

371023 2010 Grass: Newly Planted and Established 

Broadleaf 

and grass 

weeds 

Section 

3: New 

Use 

397779 2012 Expansion of Citrus Uses to Crop Group 10-10, and Expansion of 

Sunflower Uses to Crop Subgroup 20b Uses. 

Broadleaf 

and grass 

weeds 

Section 

3: New 

Use 

Potential direct risk to terrestrial and aquatic vascular and non-vascular plants from the use of 

EPTC is expected. There is also the potential for various indirect effects on non-target animal 

species due to the effects on plants (for example, depletion of food sources and habitat). Potential 

 

2 http://www.epa.gov/espp/litstatus/effects/redleg-frog/index.html#eptc 3 http://www.epa.gov/espp/litstatus/effects/redleg-frog/index.html#eptc 4 http://www.epa.gov/oppsrrd1/REDs/0064red.pdf 
5

risk was identified from both aerial and ground applications, and potentially through irrigation 

water that has received EPTC runoff. The major risk concerns thus far for EPTC are summarized 

in Table 4 and are briefly discussed in the subsections below. 

Table 4. Summary of Risk Concerns Identified for EPTC in Previous Assessments 

Birds Mammals Terrestrial 

Plants 

Terrestrial 

Inverts Fish Aquatic Inverts 

Aquatic 

Plants 

Groundwater 

Contamination Persistence Degradates of Concern 

√ √ √ - √ √ √ - - - 

Previous Drinking Water Assessments 

A summary of previous drinking water assessments is provided in Tables 5 & 6. The drinking 

water assessment prepared for the RED (Reregistration Eligibility Decision) considered only the 

parent EPTC (USEPA, 1999). More recent drinking water assessments for EPTC were 

completed in 2008 (D339490), 2010 (D371028), and 2012 (D397831). The estimated drinking 

water concentrations (EDWC) from these assessments differed from the RED due to updates in 

the PRZM and EXAMS models, and the inclusion of the EPTC sulfoxide (ESO) and EPTC 

sulfone transformation products (that can form via chlorination during water treatment). EDWCs 

presented in the 2012 assessment were modeled using the current version of PRZM and EXAMS 

to estimate concentrations in surface water, and groundwater concentrations were estimated 

using the PRZM-GW groundwater exposure model. In general, modeled EPTC surface water 

concentrations are conservative but comparable to EPTC surface water monitoring data. 

In the environmental fate studies, EPTC transformation products, ESO and EPTC sulfone, were 

either not observed or occurred as minor degradation products and appeared to be less persistent 

than EPTC. Consequently, ESO and EPTC sulfone are not expected to form in the environment 

at levels that would contribute to the overall environmental exposure to EPTC residues. 

However, ESO and EPTC sulfone can potentially form in treated drinking water via chemical 

oxidation during chlorination. The transformation process of ESO and EPTC sulfone is 

sequential process. Because these degradation products may be formed during water treatment 

and present in treated drinking water, the estimated concentration in drinking water (ECDW) for 

ESO and EPTC sulfone will be estimated assuming 100% transformation of EPTC to ESO or 

EPTC sulfone. 

Table 5. EPTC Drinking Water Assessment Summary (Surface Water). 

DP Barcode Year Use Site and/or 

Regulatory Action Compound 

Surface Water 

(Tier II) 

Peak 

Concentratio

n 

μg/L (ppb) 

Yearly Mean 

Concentratio

n μg/L (ppb) 

Average of 

Yearly 

Concentratio

ns 

μg/L (ppb)

Reregistratio

n Eligibility 

Decision 

1999 

Reregistration eligibility 

of all registered uses in 

US at the time of the 

evaluation 

EPTC 6.35 to 57.35 0.40 to 3.40 0.19 to 3.80 
6

D339490 2008 

Fallow/Idle 

Sunflower (regional 

expansion) 

Sunflower and Potato 

label modificationsa 

EPTC 

ESO 

EPTC 

Sulfone 

259.4 

281.1 

303.2 

19.6 

21.2 

22.9 

9.7 

10.5 

11.3 

D371028 2010 Grasses grown for seed 

EPTC 

ESO 

EPTC 

Sulfone 

126.05 

136.64 

147.35 

8.13 

8.81 

9.50 

4.38 

4.75 

5.12 

D397831 2012 

Watermelon New Use 

Citrus fruit group 

(Group 10-10) 

Sunflower (subgroup 

20B) 

EPTC 

ESO 

EPTC 

Sulfone

215.46 

233.56 

251.87

12.41 

13.45 

14.51

5.00 

5.42 

5.85 

Bold font indicates the highest EDWCs resulted from uses modeled in this assessment and were the recommended 

EDWCs for consideration in the most recent human health assessment (2012). a

 Label modifications were as follows: adding post-emergent application to sunflowers, reducing PHI on potatoes, 

and increasing the post-plant pre-emergence rate on potatoes. 

Table 6. EPTC Drinking Water Assessment Summary (Groundwater) 

DP Barcode Year Use Site and/or Regulatory 

Action Compound 

Groundwater 

(Tier I) 

Peak 

Concentration 

μg/L (ppb) 

Yearly Mean 

Concentratio

n μg/L (ppb) 

Reregistratio

n Eligibility 

Decision 

1999 Reregistration eligibility of all 

relevant uses in US EPTC 1.84 to 5.89 

D339490 2008 

Fallow/Idle 

Sunflower regional expansion 

Sunflower and Potato label 

modificationsa 

EPTC 

ESO 

EPTC Sulfone 

2.87 

11.2 

11.2 

D371028 2010 Grasses grown for seed 

EPTC 

ESO 

EPTC Sulfone 

1.02 

4.35 

4.69 

D397831 2012 

Watermelon New Use 

Citrus fruit group (Group 10-10) 

Sunflower (subgroup 20B) 

EPTCb

ESOc

EPTC 

Sulfonec

224 

- 

- 

176 

- 

-

a

 Label modifications were as follows: adding post-emergent application to sunflowers, reducing PHI on potatoes, 

and increasing the post-plant pre-emergence rate on potatoes. b

 Concentrations calculated using the PRZM-GW groundwater exposure model. 

c The 2012 assessment assumes that ground water does not undergo chlorination water treatment, and consequently 

ESO and EPTC Sulfone are not produced in groundwater. 

Clean Water Act Programs 

An Aquatic Life Ambient Water Quality Criteria document has not been published specifically 

for EPTC. Based on EPA’s WATERS Expert Query Tool 

(http://iaspub.epa.gov/pls/waters/f?p=ASKWATERS:EXPERT:0:::::), EPTC has not been 

identified as a cause of impairment for any water bodies listed as impaired under section 303(d) 

of the Clean Water Act. It does not appear as though any US states, territories, or tribes have 

developed Total Maximum Daily Load (TMDL) criteria for EPTC. 
7

3. ENVIRONMENTAL FATE AND TRANSPORT 

Physical and Chemical Properties of EPTC 

The physicochemical properties of EPTC are shown in Table 7. Based on these properties alone, 

EPTC is expected to be highly volatile in soil and water. 

Table 7. Selected Physical/Chemical Parameters of EPTC 

Parameter Value Source/Classification

Molecular mass (molecular formula) 189.32 g/mol (C9H19NOS) EPI Suite 4.1 

Vapor pressure (20°C) 1.60 x 10-2 mm Hg MRID 42120801 

Henry’s Law coefficient (calculated 

from partial pressure and solubility 

@20o

C) 

1.08 x 10-5 atm-m3

/mol MRID 42120801 

Aqueous solubility (20C) 370 mg/L MRID 42120801 

Log octanol-to-water partition 

coefficient 

(log KOW) (PAI, 25C) 

3.34 MRID 42120801 

Environmental Fate Properties of EPTC 

Environmental fate properties of EPTC are summarized in Table 8. The primary dissipation 

process for EPTC is volatilization, though runoff and leaching are also important dissipation 

processes for EPTC. EPTC is expected to be moderately mobile in soil. The major degradation 

process for EPTC is microbial-mediated metabolism in soil. Since the major dissipation and 

degradation pathways of EPTC appear to be volatilization and microbial-mediated metabolism, 

respectively, EPTC may be more persistent in soil substrata with lower microbial activity, or in 

ground water and deep surface water. The overall results of its mechanisms of dissipation and 

degradation indicate that EPTC has low to moderate persistence in the environment. Abiotic 

hydrolysis and photodegradation are not important degradation pathways for EPTC. 

Because EPTC is fairly volatile, it is important to understand the fate of EPTC once in the 

atmosphere. Majewski and Capel5

 report observed concentrations of EPTC ranging from 1 to 28 

μg/L (ppb) in rain water. An atmospheric chemistry study conducted for thiocarbamates by 

Kwok, E.S. et al. indicated that the dominant removal process for EPTC in air during daylight 

hours was reaction with OH-

, and that EPTC would have a short atmospheric lifetime of less than 

one day due to its reaction with OH-

 radicals (MRID 42541001). Analyses of the residues 

produced in the OH-

 radical reaction showed that S-ethyl N-formyl-N-propylthiocarbamate was 

the only significant product formed. 

 

5

 Majewski, M. and D. Capel. 1995, Pesticides in the Hydrologic System: Pesticides in the Atmosphere – 

Distribution, Trends, and Governing Factors. Ann Arbor Press, Page 159. 
8

Because volatilization is a primary dissipation pathway for EPTC, preliminary estimates for 

possible exposure of terrestrial organisms to EPTC vapor after field application were calculated. 

These exposure estimates represent the worst-case scenario and are based on the maximum 

EPTC vapor flux rate reported in a field volatility study (MRID 40420404). In this study, a 

flood-irrigated EPTC application to post-emergent alfalfa at a rate of 2.68 lb a.i./acre resulted in 

a maximum vapor flux rate of 18.5 lb a.i./hour. Note that while this field volatility study provides 

sufficient data to estimate inhalation exposures for ecological risk assessment, additional 

volatility data may be needed to estimate potential human exposures to EPTC given the inherent 

uncertainties associated with using this study to estimate EPTC inhalation exposure, as described 

in the paragraphs below. 

Field volatility studies are typically conducted in a manner similar to terrestrial field dissipation 

studies (OCSPP 835.6100); therefore, the maximum single application rate of all uses is 

normally recommended for such studies. However, the EPTC field volatility study available for 

consideration was conducted using an application rate (2.68 lb a.i/acre) much lower than the 

maximum single application rate of 14.8 lb a.i./acre currently permitted for ornamental trees, 

shade trees, and ornamental woody shrubs and vines. In addition to this ornamental tree, shrub, 

and vine use, numerous other uses also have maximum single application rates higher than those 

used in the available flux study (see Appendix D). 

In the absence of flux data from application rates greater than 2.68 lb a.i./acre or data suggesting 

EPTC flux rates do not increase linearly with respect to the application rate, the EPTC vapor flux 

rate was assumed to be directly proportional to the application rate (i.e., an application rate of 

14.8 lb a.i./acre would result in a vapor flux rate of 102 lb a.i./hour). This assumption is justified, 

as one would expect less material to leave the field if the application rate were lowered. 

However, there is some uncertainty with scaling up the application rate, as it is unclear as to how 

the diffusion of EPTC into the air would be impacted by the increase in the amount of 

formulation applied. 

Using an estimated vapor flux rate of 102 lb a.i./hour to represent the worst-case scenario (i.e., a 

scenario representative of the highest application rate for EPTC), a maximum 1-hour 

concentration of EPTC vapor was calculated using the AERSCREEN model (accessible at 

http://www.epa.gov/ttn/scram/dispersion_screening.htm#aerscreen). The output from the 

AERSCREEN model run is located in Appendix C. The results of this screen indicate that a 

maximum 1-hour post-application air concentration of 34.06 mg/m3 may be expected 400 meters 

from the center of a square 80-acre field (i.e., a field with four sides each measuring 568.99 

meters) after an application of 14.8 lb a.i./acre. 
9

 

Table 8. Environmental Fate Parameters of EPTC 

Parameter Value Source/Classification

Persistence

Hydrolysis half-life (25C and 40C) Stable MRID 00141373/ 

acceptable

Aqueous photolysis half-life (25C) Stable MRID 42120803/ 

acceptable 

Soil photolysis half-life (25C) Stable MRID 42120804/ 

acceptable 

Aerobic soil metabolism half-life 

[degradation half-life ] (28±1C) 153.3 days1

MRID 40420402/ 

supplemental 

Estimate based on 

EFED Guidance which 

recommends using 3 

times the Aerobic Soil 

Metabolism half-life 

when data from only 

one soil type are 

available 

Aerobic aquatic metabolism half-life 

[degradation half-life ] 306.6 days 

No data available 

Calculations based on 

EFED Guidance which 

recommends using 2 

times the Aerobic Soil 

Metabolism half-life 

Anaerobic soil metabolism half-life Assumed to be stable Lack sufficient data to 

estimate 

Anaerobic aquatic metabolism half-life Assumed to be stable No data available

Mobility

Organic carbon-normalized adsorption 

coefficient (KOC) 

Freundlich adsorption coefficient (Kads) 

sandy loam: 262 

loamy sand: 146 

loam: 143 

silt loam: 136

sandy loam: 0.76 (1/n = 0.90) 

loamy sand: 1.61 (1

/n = 0.93) 

loam: 2.57 (1

/n = 0.95) 

silt loam: 2.99 (1

/n = 0.90) 

MRID 42120808/ 

acceptable 
10

Parameter Value Source/Classification

Adsorption ratios (Kds) 

sandy loam: 0.38 

loamy sand: 0.68 

clay loam: 1.28 

loam: 1.82 

MRID 40420403/ 

acceptable 

Field Dissipation 

Terrestrial field dissipation half-life 

18.8 days – corn application in CO 

12.7 days – MN, crop not specified 

9.9 days – corn application in NC 

26.6 days – KY, crop not specified 

56.8 days – corn application in OH 

MRID 98250/ 

supplemental 

16.9 days – bare ground application in 

MS 

MRID 146934/ 

supplemental 

7.7 days – incorporated application to 

bare ground in FL 

MRID 146935/ 

supplemental 

6 days – incorporated pre-plant 

application to potatoes in MS 

MRID 40420405/ 

supplemental 

8 days – incorporated pre-plant 

application to succulent beans in CA 

MRID 40420406/ 

supplemental 

4.8 days – incorporated pre-plant 

application to corn in CA 

MRID 40420407/ 

supplemental 

3 to 6 days – irrigated post-plant 

application to alfalfa in CA 

MRID 41724305/ 

supplemental 

2 days – incorporated and irrigated 

bare ground application in CA 

MRID 42120810/ 

supplemental 

7 days – incorporated and irrigated 

bare ground application in CA 

MRID 42120811/ 

supplemental 

Fish Bioconcentration

Fish bioconcentration factor (steady 

state) 

Depuration rate constant

edible fish: 33x 

whole fish: 57x 

non-edible fish: 80x 

edible fish: 0.14 

whole fish: 0.15 

non-edible fish: 0.21 

Supplemental MRIDs 

40575101, 40575102 

1. The aerobic soil metabolism half-life estimate is based on an EPTC measurements in keeton soil from 

MRID 40420402, and do not include volatilization; i.e., the total amount of EPTC residues remaining after 

application was calculated by adding EPTC extracted from the soil as well as EPTC extracted from foam 

plugs that had captured volatilized EPTC. See Appendix E for the keeton soil aerobic half-life calculation. 

2. Range based on study conducted for four soil types: Keeton, Columbia, Sorrento, and Atterberry. KOC

variation was mostly attributable to soil organic carbon content. 
11

Transformation Products 

A few environmental fate studies, mainly mobility studies, have been submitted for the EPTC 

transformation products. EPTC does not appear to have any major transformation/degradation 

products (>10% of applied) resulting from environmental processes in soil and water. EPTC’s 

primary minor transformation/degradation products in soil and water are EPTC sulfoxide (ESO) 

and dipropylamine (a synonym is di-n-propylamine). Available data suggest that they occur as 

relatively low percentages of applied radio-labeled EPTC, do not accumulate, and degrade at rates 

similar to the parent EPTC. 

Table 9. Environmental Fate Parameters of EPTC Transformation Products 

Transformation 

Product Parameter Value Source/ 

Classification 

Mobility 

EPTCSulfoxide 

(ESO) 

Organic carbon-normalized 

adsorption coefficient (KOC) 

Freundlich adsorption coefficient 

(Kads)

KOC ranges from 13 to 67 

Kads ranges from 0.13 to 1.15 

45306701/ 

supplemental 

4. RECEPTORS 

Assessment of risk is based on the most sensitive species tested for terrestrial and aquatic 

organisms. The acute and chronic toxicity values for the most sensitive aquatic animals and 

plants tested are presented in Table 10. The most sensitive terrestrial animal acute and chronic 

toxicity values are presented in Table 11, and the terrestrial plant toxicity data are presented in 

Table 12. The complete available ecotoxicity dataset can be found in Appendix A. 

Aquatic Toxicity Summary 

Table 10 summarizes the most sensitive ecological toxicity endpoints for aquatic organisms. On 

an acute exposure basis, EPTC is slightly toxic to freshwater and saltwater fish (LC50s = 14 and 

17 mg a.i./L) and moderately to highly toxic to freshwater and saltwater invertebrates (6.5 and 

0.63 mg a.i./L). The only aquatic animal chronic toxicity study available for EPTC is a daphnia 

study, which showed reproductive, survival and growth effects. Available saltwater invertebrate 

data showed a higher sensitivity than freshwater invertebrates to EPTC acute toxicity. For 

crustaceans, saltwater shrimp (Penaeus setiferus) were an order of magnitude more sensitive 

than freshwater daphnia (Daphnia magna). A daphnid life-cycle study was available to assess the 

potential chronic risks of EPTC to freshwater invertebrates. An NOAEC of 0.81 mg/L based on a 

reduction in the number of offspring was established in the study and used to calculate RQs. The 

48-hr EC50 was 6.5 mg/L. An acute to chronic ratio (ACR; acute divided by chronic endpoints, 

6.5/0.8 = 8) from daphnid data was applied to white shrimp acute data, resulting in a chronic 

endpoint of 0.08 mg a.i./L. EPTC is also toxic to aquatic vascular and non-vascular plants, 

impacting both growth and biomass. 

 
12

Table 10. Summary of the Most Sensitive Endpoints from Aquatic Toxicity Studies for 

EPTC 

Assessment 

Endpoint

Acute/ 

Chronic Species 

Tested 

Toxicity Value 

Used in Risk 

Assessment 

Citation or 

MRID 

Comment 

Freshwater 

fish 

Acute Bluegill 

sunfish 

Lepomis 

macrochirus

96-h LC50 = 14 

mg/L (nominal 

concentrations1

) 

00144208 Acceptable/Slightly 

toxic1 

NOAEC = 4.2 mg/L; 

LOAEC = 10 mg/L based 

on sublethal effects. 100% 

mortality observed at ≥ 24 

mg/L 

(nominal concentrations1

) 

Chronic -- No data. -- 

Freshwater 

invertebrates 

Acute Water flea 

Daphnia 

magna

48-h EC50 = 6.5 

mg/L (mean 

measured 

concentration) 

42945601 Acceptable/ Moderately 

toxic1 

NOAEC = 1.7 mg/L 

(mean measured). 

LOAEC = 3.2 mg/L based 

on immobility (nominal 

concentration2

).

Chronic Water flea 

D. magna

Reproduction: 

NOAEC = 0.8 

mg/L 

LOAEC = 1.3 

mg/L 

(mean measured 

concentrations) 

45075006 Acceptable 

Survival: 

NOAEC = 1.3 mg a.i./L 

LOAEC = 2.7 mg a.i/L. 

Growth: 

NOAEC = 1.3 mg a.i./L

LOAEC = 2.7 mg a.i./L 

(mean measured 

concentrations)

Estuarine/ 

marine fish 

Acute Sheepshead 

minnow 

Cyprinodon 

variegattis

96-h LC50 = 17 

mg a.i./L 

(mean measured 

concentrations)

46145903 Acceptable/Slightly 

Toxic1 

NOAEC = 10 mg/L; 

LOAEC = 18 mg/L 

based on sublethal 

effects. 55% mortality 

observed at 18 mg/L 

(mean measured 

concentrations) 

Chronic -- No Data -- 

Estuarine/ 

marine 

invertebrates 

Acute Eastern 

oyster 

Crassostrea 

Virginica 

White 

shrimp 

Penaeus 

setiferus

96-h EC50 = 1.8 

mg a.i./L 

48-h LC50 = 0.63 

mg a.i./L 

46145901 

40228401

Acceptable/ Moderately 

Toxic1 

Supplemental/ Highly 

Toxic2

Chronic White 

shrimp 

Penaeus 

setiferus

NOAEC = 0.08 

mg a.i./L 

N/A NOAEC calculated using 

daphnid ACR3

 
13

Aquatic plants 

Nonvascular 

Green Algae 

Pseudokirch

neriella 

subcapitata

4-d EC50 = 1.4 

mg/L 

42921202 

42899801 

Acceptable 

NOAEC = 0.9 mg/L 

LOAEC = 1.6 mg/L (% 

inhibition and cell 

density) 

Vascular Duckweed 

Lemna 

gibba

Biomass: 

EC50 = 5.6 mg 

a.i./L 

NOAEC= 0.89 

mg a.i./L 

Frond Number 

EC50: 6.7 mg 

a.i./L 

NOAEC: 0.29 

mg a.i./L 

43096001 

Acceptable 

LOAEC (biomass): 2.9 

mg a.i./L 

LOAEC (frond number): 

0.89 mg a.i./L 

1 Based on EC50 (mg/L): < 0.1 very highly toxic; 0.1-1 highly toxic; >1-10 moderately toxic; >10-100 slightly 

toxic; >100 practically nontoxic 

2 EPTC has the potential to volatilize during aquatic toxicity tests; measured test concentrations from static 

daphnid, duckweed and algal studies show that EPTC volatilizes from water at levels ranging from 2 to about 

50% losses. These data suggest that test concentrations at the end of 96-h static non-renewal aquatic studies 

would be 20 to 25 percent less than initial nominal concentrations. Applying an average between initial and 

predicted final test concentrations, estimated mean test concentrations would be 10 to 13 percent less than 

nominal test concentrations; thus, fish LC50 values are approximately 10 percent lower than the toxicity values 

listed above. 

3

Acute to Chronic Ratio (ACR) from daphnid data (acute divided by chronic endpoints, 6.5/0.8 = 8). 

Terrestrial Toxicity Summary

Table 11 summarizes the most sensitive ecological toxicity endpoints for terrestrial organisms. 

On an acute exposure basis EPTC is practically non-toxic to slightly toxic to birds (most 

sensitive LD50 >1000 mg a.i./L), mammals (most sensitive LD50 = 1465 mg/kg-bw), and 

honeybees (LD50 >12.09 μg a.i./bee). Effects were reported for birds and mammals from dietary, 

reproduction, and inhalation studies. As expected from an herbicide, terrestrial plants are highly 

sensitive to EPTC (Table 12). 

 
14

Table 11. Summary of the Most Sensitive Endpoints from Terrestrial Toxicity Studies for 

EPTC 

Species Toxicity Value Used in 

Risk Assessment 

Citation 

MRID 

Comment 

Mallard Duck 

Anas platyrhynchos

LD50 > 1000 mg a.i./kgbw 

00131274 Supplemental. No more than slightly 

toxic1

. 

NOAEL: 1000 mg/kg 

LOAEL > 1000 mg/kg. 

Regurgitation was observed in the two 

highest test concentrations, the NOAEL 

is based on regurgitation.

Bobwhite Quail 

Colinus virginianus

LC50 = 20,000 mg 

a.i./kg-diet 

00021834 Supplemental study. Practically nontoxic1

. 

NOAEC: 1800 mg a.i./kg diet 

LOAEC: 3200 mg a.i./kg diet 

Mallard Duck 

Anas platyrhynchos

NOAEC =242 mg a.i./kg 

diet 

46554301 Acceptable study. LOAEC: 593 mg 

a.i./kg diet based on reduction in 

proportion of viable embryos of eggs 

set at the 593 and 1490 mg a.i./kg diet 

levels (13 and 21%, respectively).

Laboratory rat 

Rattus norvegicus

Acute oral LD50 = 1465 

(1290-1663) mg/kg – bw 

(males) 

00157868 Acceptable study. Slightly toxic3

. 

Acute oral LD50: 1712 (1324-2214) 

mg/kg (F), 1599 (1294-1976) mg/kg 

(combined).

Laboratory rat 

Rattus norvegicus

Parent/ NOAEL: 50 ppm 

(2.5 mg/kg bw/day)

00161597 Acceptable study. 

Parental Toxicity 

NOAEL: 50 ppm (2.5 mg/kg bw/day) 

LOAEL: 200 ppm (10 mg/kg bw/day) 

based on decreased body weight, 

degenerative cardiomyopathy, and 

renal tubule degeneration. 

 Offspring/Developmental Toxicity 

NOAEL: 200 ppm (10 mg/kg bw/day)

LOAEL: 800 ppm (40 mg/kg bw/day). 

Reproductive Toxicity NOAEL: 800 

ppm (40 mg/kg bw/day) 

LOAEL: >800 ppm (40 mg/kg 

bw/day). 

Laboratory rat 

Rattus norvegicus

Acute Inhalation 

LC50 Male and Female 

Combined 1.39 ppm 

00157870 NOAEL 0.058 ppm based on 

myocardial degeneration observed at 21 

days in a 90-day inhalation study 

Honey bee acute 

contact

48-hour contact LD50: 

>12.09 μg a.i./bee 

00036935 Acceptable/Practically non-toxic2.

1

Acute Oral (avian/mammal): Based on LD50 (mg/kg) <10 very highly toxic; 10-50 highly toxic; 51-500 

moderately toxic; 501-2000 slightly toxic; >2000 practically nontoxic 

2

 Based on acute contact LD50 (μg a.i./bee) <2 highly toxic; 2-10.99 moderately toxic; ≥11 practically 

non-toxic 

Toxicity to Non-target Terrestrial Plants 

The available seedling emergence studies (MRIDs 42120802 and 43217101) reported EC25 

values for emergence and shoot dry weight (Table 12), in addition to qualitative observations of 
15

phytotoxicity. The former study tested 10 species of terrestrial plants, five of which had less than 

70% seedling emergence in the control treatments. Based on the mode of action, EPTC is 

expected to greatly impact plant height (length) due to developmental inhibition; however the 

available studies did not report this information. Furthermore, in addition to inhibited 

germination, the provided phytotoxicity information describes stunted and malformed plants 

early in the study extending to senescence in later stages. These effects were noted with most of 

the species at all test concentrations, further suggesting that plant height (length) may be more 

sensitive than dry weight. The registrant submitted a follow-up seedling emergence study (MRID 

43217101) which re-ran the earlier study using Triticum aestivum (poor control performance in 

the first study) as well as the first submitted test for Daucus carota. While control performance 

was adequate the study did not report the plant height endpoint. Therefore, the available seedling 

emergence endpoint information will not be used for calculating RQs, but may be used for risk 

characterization. 

The available vegetative vigor study (MRIDs 42120802) reported EC25 values for shoot dry 

weight (Table 12). The authors also report phytotoxicity information describing stunted and 

malformed plants early in the study extending to senescence in later stages. These effects were 

noted with most of the species at all test concentrations, further suggesting that plant height 

(length) may be more sensitive than dry weight. Therefore, the available vegetative vigor 

endpoint information will not be used for calculating RQs, but may be used for risk 

characterization. 

Table 12. Non-target Terrestrial Plant Seedling Emergence and Vegetative Vigor Toxicity 

(Tier II) Data (MRID 42120802). 

Crop Type of Study 

Species 

NOAEC 

[EC05]] 

(lb a.i./A) 

EC25

(lb a.i./A) 

Most sensitive 

parameter 

Slope 

Seedling Emergence1

Monocot Purple nutsedge 

Cyperus rotundus) 

0.17 

0.0144 

0.27 

0.015

Seedling 

emergence 

Dry weight 

1.13±0.425 

Dicot Morning glory 

Ipomea hederacea 

7.4 

[0.035] 

0.23 

>7.4 

0.26 

1.1 

Seedling 

emergence 

Dry weight 

Phytotoxicity 

1.10±0.206 

Vegetative Vigor1 

Monocot Winter wheat 

Triticum aestivum 

0.925 

[0.087] 

2.9 

0.22 

Dry weight 

Phytotoxicity 

2.33±0.740 

Dicot Velvet leaf 

Abutilon theophrastii

[0.085] 

[0.023] 

2.0 

7.4 

Dry weight 

Phytotoxicity 

0.704±0.370 

1

Endpoints will not be used for RQ calculations (see preceding text). 

Degradate Toxicity 

At least one degradate of EPTC was identified as EPTC sulfoxide in the fate studies. One study 

on EPTC sulfoxide was submitted for evaluating acute toxicity to freshwater invertebrates 

(MRID 45442201). This study indicates less toxicity than the parent EPTC (LC50 = 22 mg a.i./L, 
16

NOAEC = 10 mg a.i./L, LOAEC = 18 mg a.i./L). Fate studies suggest that EPTC degradates are 

shorter lived than the parent compound. Based on the volatility of EPTC, the shorter half-lives of 

the EPTC degradates (sulfoxide and sulfone), there is no need for additional acute aquatic 

toxicity tests for these degradates. 

Ecological Incidents 

A search of the Ecological Incident Information System (EIIS) database on December 5, 2012 

showed 3 “Possible” EPTC incidents affecting standing dry bean, alfalfa, and potato crops from 

direct applications, and impacting as much as 2000 acres. There was also one additional 

“Possible” incident caused by runoff following a runoff event after application to corn. This 

incident resulted in a fish kill totaling 30 bluegill and 20 bass. The incident report (ID: B000150-

001) suggests that phorate, tank mixed with EPTC, atrazine, propachlor, 2,4-D, was the likely 

stressor causing the fish kill; however it also regards the presence of EPTC as a contributing 

factor. A search of the Incident Data System (IDS) and the Avian Incident Monitoring System 

(AIMS) databases did not provide any additional incident data. 

5. CONCEPTUAL MODEL 

The environmental fate properties of EPTC indicate that volatilization, runoff, and leaching 

represent potential transport mechanisms. These pathways may result in a wide range of potential 

aquatic and terrestrial exposure scenarios. 

6. ANALYSIS PLAN 

Ecological Risk Assessment 

Stressors of Concern 

The exposure assessments will consider only the parent, EPTC, as the degradates are not 

expected to be present in environmentally relevant concentrations. 

Measures of Exposure 

In order to estimate risks of EPTC exposure to aquatic and terrestrial organisms, all exposure 

modeling and resulting risk conclusions will be made based on maximum application rates, 

application methods, and any mitigation measures specifically indicated on the label. The models 

that will be used to predict the estimated environmental concentrations (EECs) of EPTC are 

discussed on OPP’s model website.6

 These models include: PRZM (Pesticide Root Zone Model) 

and EXAMS (EXposure Analysis Modeling System), PRZM-groundwater (GW), AgDrift, 

AgDisp, T-REX, TerrPlant, and PERFUM (Probabilistic Exposure and Risk Model for 

FUMigants). 

 

6

 http://www.epa.gov/opp00001/science/models_pg.htm 
17

The results of running the SIP and STIR models are presented in Appendix A and Appendix B. 

While the SIP model suggests that there are expected concerns for both mammals and birds, the 

model does not perform well with chemicals that have a high aqueous solubility and have low 

acute toxicity to these organisms. This route of exposure is not likely to be significant enough to 

cause concern. The analysis with STIR indicates that there are potential risks to birds and 

mammals through inhalation of EPTC. 

To get a preliminary estimate for the possible exposure of terrestrial organisms to EPTC vapor 

after field application, EFED used vapor flux data reported in a supplemental field volatility 

study (MRID 40420404) to estimate a maximum 1-hour concentration of EPTC vapor using the 

AERSCREEN model (see discussion in Environmental Fate Properties of EPTC). The results of 

this screen indicated that a maximum 1-hour post-application air concentration of 34.06 mg/m3

may be expected after use of 14.8 lb a.i./acre applied by flood irrigation to an 80-acre field of 

post-emergent alfalfa. Compared to the estimated exposure using STIR (163 mg/m3

), the risk to 

mammals and birds through exposures to EPTC vapor is not expected to result in LOC 

exceedances. 

Given the high volatility of EPTC, there is the potential for non-target organisms to be exposed 

to EPTC that volatilizes from the treated field and redeposits outside the application area. To 

estimate the potential exposure to non-target taxa from the deposition of vapor phase EPTC, an 

empirical model that estimates the Aboveground Produce Concentration Due to Air-to-Plant 

Transfer (Pv)

7

 was used. This method is used to estimate concentrations in exposed and 

aboveground vegetation due to air-to-plant transfer. 

 

The estimated AERSCREEN maximum 1-hour concentration was used as the concentration of 

EPTC in air at the edge of the field (Cyv). The fraction of the concentration of EPTC in vapor 

phase was assumed to be 1. Following the recommendations the authors of the model provided in 

 

7

 USEPA. 2005. Human Health Risk Assessment Protocol for Hazardous Waste Compustion Facilities. EPA530-R05-006. Chapter 5.3.2. 
18

the appendix, the EPTC air to plant biotransfer factor (BVag) was calculated using the following 

formulae: 

Bvol = 10^(1.065*logKow-LOG10(0.0000108/0.000082053/298.15)-1.654) 

and 

BVag = 1.19*Bvol/(1-0.85)*770 

The empirical correction factor (VGag) was assumed to be 1 based on the log Kow of EPTC. 

The resulting estimation of the deposition of vapor phase EPTC in plant tissue (Pv) was 2.28 x 

108 μg EPTC/g of plant dry weight. This concentration was converted to lb/acre units to compare 

to the available Tier 2 terrestrial plant toxicity studies. This assumed one ton of dry weight grass 

per acre. The Pv estimate (0.114 lb EPTC/A) suggests that there is the potential for 

concentrations to be high enough to elicit effects on non-target terrestrial plants (Table 12, 

EC25= 0.22 lb a.i./A; EC05 = 0.023 lb a.i./A) and animals (Table 11, Chronic Mammal NOAEL= 

50 ppm (2.5 mg/kg bw/day)) from the redeposited vapor phase EPTC from fields treated under 

currently labeled rates. EFED intends to use the PERFUM model in the preliminary risk 

assessment to estimate the distance from the edge of the field where the concentration would be 

below levels of concern for non-target listed and non-listed plants and animals.

Measure of Effects 

Ecological effects data are used as measures of direct and indirect effects to biological receptors. 

Data are typically obtained from registrant-submitted studies or from literature studies identified 

by ECOTOX. The ECOTOX database provides more ecological effects data in an attempt to 

bridge existing data gaps. ECOTOX is a source for locating single chemical toxicity data and 

potential chemical mixture toxicity data for aquatic life, terrestrial plants, and wildlife. ECOTOX 

was created and is maintained by the USEPA, Office of Research and Development, and the 

National Health and Environmental Effects Research Laboratory's Mid-Continent Ecology 

Division. 

Integration of Exposure and Effects 

Risk characterization is the integration of exposure and ecological effects to determine the 

potential ecological risk from the use of pesticides and the likelihood of direct and indirect 

effects to non-target organisms in aquatic and terrestrial habitats. For the assessment of risks, the 

risk quotient (RQ) method is used to compare exposure and measured toxicity values. EECs are 

divided by acute and chronic toxicity values. The resulting RQs are then compared to the 

Agency’s Levels of Concern (LOCs) (USEPA 2004). These criteria will be used to indicate 

when EPTC use, as directed on the label, has the potential to cause adverse direct or indirect 
19

effects to non-target organisms. In addition, incident data from the EIIS, IDS, and AIMS will be 

considered as part of the risk characterization.

Endocrine Disruptor Screening Program (EDSP) 

As required by FIFRA and FFDCA, EPA reviews numerous studies to assess potential adverse 

outcomes from exposure to chemicals. Collectively, these studies include acute, subchronic and 

chronic toxicity, including assessments of carcinogenicity, neurotoxicity, developmental, 

reproductive, and general or systemic toxicity. These studies include endpoints which may be 

susceptible to endocrine influence, including effects on endocrine target organ histopathology, 

organ weights, estrus cyclicity, sexual maturation, fertility, pregnancy rates, reproductive loss, 

and sex ratios in offspring. For ecological hazard assessments, EPA evaluates acute tests and 

chronic studies that assess growth, developmental and reproductive effects in different 

taxonomic groups. As part of its reregistration decision, EPA reviewed these data and selected 

the most sensitive endpoints for relevant risk assessment scenarios from the existing hazard 

database. However, as required by FFDCA section 408(p), EPTC is subject to the endocrine 

screening part of the Endocrine Disruptor Screening Program (EDSP). 

EPA has developed the EDSP to determine whether certain substances (including pesticide 

active and other ingredients) may have an effect in humans or wildlife similar to an effect 

produced by a “naturally occurring estrogen, or other such endocrine effects as the Administrator 

may designate.” The EDSP employs a two-tiered approach to making the statutorily required 

determinations. Tier 1 consists of a battery of 11 screening assays to identify the potential of a 

chemical substance to interact with the estrogen, androgen, or thyroid (E, A, or T) hormonal 

systems. Chemicals that go through Tier 1 screening and are found to have the potential to 

interact with E, A, or T hormonal systems will proceed to the next stage of the EDSP where EPA 

will determine which, if any, of the Tier 2 tests are necessary based on the available data. Tier 2 

testing is designed to identify any adverse endocrine-related effects caused by the substance, and 

establish a dose-response relationship between the dose and the E, A, or T effect. 

Under FFDCA section 408(p), the Agency must screen all pesticide chemicals. Between October 

2009 and February 2010, EPA issued test orders/data call-ins for the first group of 67 chemicals, 

which contains 58 pesticide active ingredients and 9 inert ingredients. EPTC was included on 

that list and has been issued an order to conduct the Tier 1 testing. Once all required Tier 1 and 

Tier 2 data have been received and reviewed, the endpoints and safety factors used for risk 

assessment purposes will be examined and a new risk assessment performed if necessary. For 

further information on the status of the EDSP, the policies and procedures, the list of 67 

chemicals, future lists, the test guidelines and the Tier 1 screening battery, please visit our 

website: http://www.epa.gov/endo/. 
20

Endangered Species Assessments 

Consistent with the Agency’s responsibility under the Endangered Species Act (ESA), the 

Agency will evaluate exposure and potential risks to federally listed threatened and/or 

endangered (listed) species from registered uses of pesticides in registration review. 

7. PRELIMINARY IDENTIFICATION OF DATA GAPS 

Fate 

Table 13 identifies the environmental fate studies submitted by the registrant, as well as study 

classifications and whether or not additional data are needed in order to support the registration 

review of EPTC. Rationale for the additional data requested is also presented. 

Table 13. Submitted Environmental Fate Data for Chemical EPTC 

OCSPP 

Guideline 

Data 

Requirement 

Submitted 

Studies 

(MRID) 

Study 

Classifications 

Are data 

needed to 

conduct risk 

assessment?

Comments 

835.2120 Hydrolysis 00141373 acceptable no 

835.2240 Aqueous 

photolysis 42120803 acceptable no 

835.2410 Soil photolysis 42120804 acceptable no 

835.4100 Aerobic soil 

metabolism 

40420402 supplemental 

42120805 supplemental no 

42120806 supplemental 

835.4200 Anaerobic soil 

metabolism 

40420402 supplemental no 42120807 supplemental 

835.4300 Aerobic aquatic 

metabolism no data - 

Required in the December 21, 1999 

reregistration DCI; has not been 

submitted/fulfilled by registrant. 

835.4400 

Anaerobic 

aquatic 

metabolism 

no data no 

835.1230 

835.1240 

Adsorption/ 

desorption and 

leaching 

42120808 acceptable 

40420403 acceptable no 

45306701 supplemental 

835.1410 Volatility – 

laboratory 42120809 acceptable no 

835.8100 Volatility – field 40420404 supplemental no 

835.6100 Terrestrial field 

dissipation 

00098250 supplemental 

no Analytical method appropriate for 

EPTC but not for ESO. 

00146934 supplemental 

00146935 supplemental 

40420405 supplemental 

40420406 supplemental 

40420407 supplemental 

41724305 supplemental 
21

OCSPP 

Guideline 

Data 

Requirement 

Submitted 

Studies 

(MRID) 

Study 

Classifications 

Are data 

needed to 

conduct risk 

assessment?

Comments 

42120810 supplemental 

42120811 supplemental 

Analytical 

method in soil 41724305 supplemental no 

835.6200 Aquatic field 

dissipation no data no 

850.1730 Fish 

bioconcentration 

40575101 supplemental 

40575102 supplemental no 

45124301 none 

Effects 

Table 14 and Table 15 identify the ecological effects studies, as well as study classifications and 

whether or not further data are needed in order to support risk assessment. 

Table 14. Submitted Aquatic Ecological Effects Data for EPTC 

OCSPP 

Guideline 

Data 

Requirement 

Submitted 

Studies 

(MRID) 

Study 

Classifications

Are data 

needed to 

conduct 

risk 

assessment?

Comments 

 850.1010 Freshwater 

invertebrate 

acute toxicity 

 42945601 Acceptable No -- 

00144209 Acceptable 

00131273 Acceptable 

45442201 Supplemental 

00016546 Supplemental 

40094602 Supplemental 

05001497 Supplemental 

850.1025 

850.1035 

850.1045 

850.1055 

Saltwater 

invertebrate 

acute toxicity 

46145901 Acceptable No -- 

46145902 Acceptable 

Meyer 1986 Supplemental 

Butler 1965 Supplemental 

 850.1075 Freshwater fish 

acute toxicity 

00144208 Acceptable No -- 

00021834 Acceptable 

00022361 Supplemental 

00131271 Acceptable 

00131272 Acceptable 

00025286 Supplemental 

00025287 Supplemental 
22

OCSPP 

Guideline 

Data 

Requirement 

Submitted 

Studies 

(MRID) 

Study 

Classifications

Are data 

needed to 

conduct 

risk 

assessment?

Comments 

00027992 Supplemental 

00034683 Supplemental 

00034684 Supplemental 

00084743 Supplemental 

00108342 Supplemental 

40094602 Supplemental 

 850.1075 Saltwater fish 

acute toxicity 

46145903 Acceptable No -- 

Meyer 1986 Supplemental 

 850.1300 Freshwater 

invertebrate 

life cycle 

45075006 Acceptable No -- 

 850.1350 Saltwater 

invertebrates 

life cycle1

 

 Yes Due to the moderate toxicity of 

EPTC to freshwater and estuarine 

invertebrates based on the 

available acute and chronic 

toxicity data, and the potential for 

exposure based on the current 

labels, this chronic reproduction 

study would help to define the 

potential chronic and 

reproductive risks to 

invertebrates in estuarine/marine 

environments. 

 850.1400 Freshwater fish 

early-life 

stage1 

 Yes A Freshwater Fish early-life 

stage study is requested due to 

the moderate toxicity of EPTC to 

freshwater and estuarine fish 

based on the available acute 

toxicity data, and the potential for 

exposure based on the current 

labels. Since the bluegill sunfish 

was acutely the most sensitive 

fish species, it should be used as 

the test species. 

 850.1400 Saltwater fish 

early-life stage 

 No This study is not requested at this 

time based on the expectation 

that this study using a freshwater 

fish will be submitted. 

 850.1500 Fish life cycle No -- 

850.4400 Aquatic plant 

growth: 

Tier II vascular 

plants 

43096001 Acceptable No -- 
23

OCSPP 

Guideline 

Data 

Requirement 

Submitted 

Studies 

(MRID) 

Study 

Classifications

Are data 

needed to 

conduct 

risk 

assessment?

Comments 

850.4500 Aquatic Plant 

Growth: 

Tier II Algal 

Toxicity 

42921202 Acceptable No -- 

42921201 Acceptable 

42899801 Acceptable 

42940901 Acceptable 

850.4550 Aquatic Plant 

Growth: 

Tier II 

Cyanobacteria 

Toxicity 

42883501 Acceptable No -- 

1

This study is an outstanding data requirement identified in the data requirement table in the EFED science chapter 

of the RED, and in memos to the registration division dated January 9, 2002 (D274065), and April 4, 2002 

(D277872, D278969, D274497). In the absence of this study, an acute to chronic ratio approach will be used. 

Table 15. Submitted Terrestrial Ecological Effects Data for EPTC 

OCSPP 

Guideline 

Data 

Requirement 

Submitted 

Studies 

(MRID) 

Study 

Classifications

Are data needed 

for risk 

assessment? 

Comments 

 850.2100 Avian oral 

toxicity 

00131274 Supplemental Yes An acceptable acute avian oral 

toxicity study for exposures of 

bobwhite quail and a 

supplemental study for mallard 

duck were submitted for EPTC; 

however, data are not available 

for a passerine species. In 

addition to the CFR part 158 

data requirements, the available 

data support the need for the 

passerine acute oral toxicity 

study to adequately assess the 

risk to passerine species. A 

passerine study protocol should 

be submitted for review by the 

Agency prior to initiation of 

this study. 

An acceptable acute avian oral 

toxicity study for exposures of 

bobwhite quail or mallard duck 

was requested in a DCI for the 

degradate EPTC sulfoxide. This 

study was requested in the RED 

and remains outstanding. 

00144280 Supplemental 

 850.2200 Avian dietary 

toxicity 

00016527 Supplemental No -- 

00016539 Supplemental 

00021834 Supplemental 
24

OCSPP 

Guideline 

Data 

Requirement 

Submitted 

Studies 

(MRID) 

Study 

Classifications

Are data needed 

for risk 

assessment? 

Comments 

00022361 Supplemental 

00131275 Supplemental 

00131276 Supplemental 

00144207 Supplemental 

 850.2300 Avian 

reproduction 

46554301 Acceptable No -- 

46554302 Acceptable 

 850.3020 Honey bee 

acute contact 

toxicity 

00142894 Acceptable No -- 

 Honey bee 

acute oral 

toxicity 

 No -- 

850.3030 Honey bee 

residue on 

foliage 

 No -- 

 850.3040 Field testing 

for pollinators 

 No -- 

850.4100 Terrestrial 

plant toxicity: 

Tier II seedling 

emergence 

42120802 

43217101 

Supplemental Yes A Tier II Seedling Emergence 

study is needed for a typical 

end use product. Available 

toxicity data suggest that 

terrestrial plants are highly 

sensitive to EPTC, however the 

available submitted studies did 

not report plant height and 

failed to maintain greater than 

70% seedling germination in 

many of the controls. 

850.4150 Terrestrial 

plant toxicity: 

Tier II 

vegetative 

vigor 

42120802 Supplemental Yes A Tier II Vegetative Vigor 

study is needed for a typical 

end use product. Available 

toxicity data suggest that 

terrestrial plants are highly 

sensitive to EPTC, however the 

available submitted studies did 

not report plant height. 

Additional effects information that would be useful to the Agency include: 

1. ecological incidents (non-target plant damage and avian, fish, reptilian, amphibian and 

mammalian mortalities) not already reported to the Agency 

2. major degradate or transformation product toxicity data 

3. information regarding effects of EPTC on plant reproduction (e.g., fruit numbers, seed 

numbers, volume and weight of seed, number of flowers) 
25

4. label clarifications including maximum number of applications per year, maximum 

application rate per year, and the minimum application treatment interval 

 
26

APPENDIX A: RESULTS OF THE SIP MODEL 

 Table 1. Inputs 

 Parameter Value 

 Chemical name EPTC 

 Solubility (in water at 25oC; mg/L) 370 

 

 Mammalian LD50 (mg/kg-bw) 1465 

 Mammalian test species laboratory rat 

 Body weight (g) of "other" mammalian species 

 

 Mammalian NOAEL (mg/kg-bw) 50 

 Mammalian test species laboratory rat 

 Body weight (g) of "other" mammalian species 

 

 Avian LD50 (mg/kg-bw) 1000 

 Avian test species mallard duck 

 Body weight (g) of "other" avian species 

 Mineau scaling factor 1.15 

 

 Mallard NOAEC (mg/kg-diet) 242 

 Bobwhite quail NOAEC (mg/kg-diet) 1800 

 NOAEC (mg/kg-diet) for other bird species 

 Body weight (g) of other avian species 

 NOAEC (mg/kg-diet) for 2nd other bird species 

 Body weight (g) of 2nd other avian species 

 Table 2. Mammalian Results 

 Parameter Acute Chronic 

 Upper bound exposure (mg/kg-bw) 63.6400 63.6400 

 Adjusted toxicity value (mg/kg-bw) 1126.8202 38.4580 

 Ratio of exposure to toxicity 0.0565 1.6548 

 

Conclusion* 

Drinking water 

exposure alone is NOT 

a potential concern for 

mammals 

Exposure through 

drinking water alone is 

a potential concern for 

mammals 

 Table 3. Avian Results 

 Parameter Acute Chronic 

 Upper bound exposure (mg/kg-bw) 299.7000 299.7000 

 Adjusted toxicity value (mg/kg-bw) 519.2254 12.0062 

 Ratio of exposure to acute toxicity 0.5772 24.9620 

 

Conclusion* 

Exposure through 

drinking water alone is 

a potential concern for 

birds 

Exposure through 

drinking water alone is 

a potential concern for 

birds 

*Conclusion is for drinking water exposure alone. This does not combine all routes of exposure. 

Therefore, when aggregated with other routes (i.e., diet, inhalation, dermal), pesticide exposure 

through drinking water may contribute to a total exposure that has potential for effects to non-target 

animals. 

 
27

APPENDIX B: RESULTS OF THE STIR MODEL 

Input for Sunflower Uses 

Application and Chemical Information 

Enter Chemical Name EPTC 

Enter Chemical Use Sunflower 

Is the Application a Spray? (enter y or n) y 

If Spray What Type (enter ground or air) air 

Enter Chemical Molecular Weight (g/mole) 189.3 

Enter Chemical Vapor Pressure (mmHg) 1.60E-02 

Enter Application Rate (lb a.i./acre) 4.6 

 

Toxicity Properties 

Bird 

Enter Lowest Bird Oral LD50 (mg/kg bw) 1000 

Enter Mineau Scaling Factor 1.15 

Enter Tested Bird Weight (kg) 1.58 

Mammal 

Enter Lowest Rat Oral LD50 (mg/kg bw) 1465 

Enter Lowest Rat Inhalation LC50 (mg/L) 3.8 

Duration of Rat Inhalation Study (hrs) 4 

Enter Rat Weight (kg) 0.35 

 

Output 

Results Avian (0.020 kg ) 

Maximum Vapor Concentration in Air at Saturation (mg/m3) 1.63E+02 

Maximum 1-hour Vapor Inhalation Dose (mg/kg) 2.05E+01 

Adjusted Inhalation LD50 1.04E+01 

Ratio of Vapor Dose to Adjusted Inhalation LD50 1.97E+00 Proceed to Refinements 

Maximum Post-treatment Spray Inhalation Dose (mg/kg) 4.42E-01 

Ratio of Droplet Inhalation Dose to Adjusted Inhalation LD50 4.24E-02 Exposure not Likely Significant 

 

Results Mammalian (0.015 kg ) 

Maximum Vapor Concentration in Air at Saturation (mg/m3) 1.63E+02 

Maximum 1-hour Vapor Inhalation Dose (mg/kg) 2.58E+01 

Adjusted Inhalation LD50 2.26E+02 

Ratio of Vapor Dose to Adjusted Inhalation LD50 1.14E-01 Proceed to Refinements 

Maximum Post-treatment Spray Inhalation Dose (mg/kg) 5.55E-01 

Ratio of Droplet Inhalation Dose to Adjusted Inhalation LD50 2.46E-03 Exposure not Likely Significant 
28

Input for Watermelon Uses 

Application and Chemical Information 

Enter Chemical Name EPTC 

Enter Chemical Use Watermelon 

Is the Application a Spray? (enter y or n) n 

If Spray What Type (enter ground or air) ground 

Enter Chemical Molecular Weight (g/mole) 189.3 

Enter Chemical Vapor Pressure (mmHg) 1.60E-02 

Enter Application Rate (lb a.i./acre) 3.5 

 

Toxicity Properties 

Bird 

Enter Lowest Bird Oral LD50 (mg/kg bw) 1000 

Enter Mineau Scaling Factor 1.15 

Enter Tested Bird Weight (kg) 1.58 

Mammal 

Enter Lowest Rat Oral LD50 (mg/kg bw) 1465 

Enter Lowest Rat Inhalation LC50 (mg/L) 3.8 

Duration of Rat Inhalation Study (hrs) 4 

Enter Rat Weight (kg) 0.35 

 

Output 

Results Avian (0.020 kg ) 

Maximum Vapor Concentration in Air at Saturation (mg/m3) 1.63E+02 

Maximum 1-hour Vapor Inhalation Dose (mg/kg) 2.05E+01 

Adjusted Inhalation LD50 1.04E+01 

Ratio of Vapor Dose to Adjusted Inhalation LD50 1.97E+00 Proceed to Refinements 

Maximum Post-treatment Spray Inhalation Dose (mg/kg) not applicable 

Ratio of Droplet Inhalation Dose to Adjusted Inhalation LD50 not applicable not applicable 

 

Results Mammalian (0.015 kg ) 

Maximum Vapor Concentration in Air at Saturation (mg/m3) 1.63E+02 

Maximum 1-hour Vapor Inhalation Dose (mg/kg) 2.58E+01 

Adjusted Inhalation LD50 2.26E+02 

Ratio of Vapor Dose to Adjusted Inhalation LD50 1.14E-01 Proceed to Refinements 

Maximum Post-treatment Spray Inhalation Dose (mg/kg) not applicable 

Ratio of Droplet Inhalation Dose to Adjusted Inhalation LD50 not applicable not applicable 

 
29

APPENDIX C: AERSCREEN OUTPUT 

AERSCREEN 11126 / AERMOD 1206 01/04/13 

 14:00:27 

 TITLE: EPTC TEST 

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

 ****************************** AREA PARAMETERS **************************** 

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

 SOURCE EMISSION RATE: 12.8600 g/s 102.063 lb/hr 

 AREA EMISSION RATE: 0.397E-04 g/(s-m2) 0.315E-03 lb/(hr-m2) 

 AREA HEIGHT: 0.18 meters 0.60 feet 

 AREA SOURCE LONG SIDE: 568.99 meters 1866.76 feet 

 AREA SOURCE SHORT SIDE: 568.99 meters 1866.76 feet 

 INITIAL VERTICAL DIMENSION: 0.00 meters 0.00 feet 

 RURAL OR URBAN: RURAL 

 INITIAL PROBE DISTANCE = 5000. meters 16404. feet 

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

 *********************** BUILDING DOWNWASH PARAMETERS ********************** 

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

 BUILDING DOWNWASH NOT USED FOR NON-POINT SOURCES 

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

 ************************** FLOW SECTOR ANALYSIS *************************** 

 25 meter receptor spacing: 1. meters - 5000. meters 

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

 MAXIMUM IMPACT RECEPTOR 

 Zo SURFACE 1-HR CONC RADIAL DIST TEMPORAL 

 SECTOR ROUGHNESS (ug/m3) (deg) (m) PERIOD 

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

 1* 0.050 0.3406E+05 45 400.0 ANN 

 * = worst case diagonal 

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

 ********************** MAKEMET METEOROLOGY PARAMETERS ********************* 

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

 MIN/MAX TEMPERATURE: 287.1 / 302.0 (K) 

 MINIMUM WIND SPEED: 0.5 m/s 
30

 ANEMOMETER HEIGHT: 10.000 meters 

 SURFACE CHARACTERISTICS INPUT: USER ENTERED 

 ALBEDO: 0.18 

 BOWEN RATIO: 0.30 

 ROUGHNESS LENGTH: 0.050 (meters) 

 METEOROLOGY CONDITIONS USED TO PREDICT OVERALL MAXIMUM IMPACT 

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

 YR MO DY JDY HR 

 -- -- -- --- -- 

 10 01 11 11 01 

 H0 U* W* DT/DZ ZICNV ZIMCH M-O LEN Z0 BOWEN ALBEDO REF WS 

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

 -0.37 0.019 -9.000 0.020 -999. 30. 1.7 0.050 0.30 0.18 0.50 

 HT REF TA HT 

 - - - - - - - - - - - 

 10.0 302.0 2.0 

 METEOROLOGY CONDITIONS USED TO PREDICT AMBIENT BOUNDARY IMPACT 

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

 YR MO DY JDY HR 

 -- -- -- --- -- 

 10 01 11 11 01 

 H0 U* W* DT/DZ ZICNV ZIMCH M-O LEN Z0 BOWEN ALBEDO REF WS 

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

 -0.37 0.019 -9.000 0.020 -999. 30. 1.7 0.050 0.30 0.18 0.50 

 HT REF TA HT 

 - - - - - - - - - - - 

 10.0 302.0 2.0 

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

 ************************ AERSCREEN AUTOMATED DISTANCES ********************** 

 OVERALL MAXIMUM CONCENTRATIONS BY DISTANCE 

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

 MAXIMUM MAXIMUM 

 DIST 1-HR CONC DIST 1-HR CONC 

 (m) (ug/m3) (m) (ug/m3) 

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

 1.00 0.2516E+05 2524.99 6143. 

 25.00 0.2583E+05 2550.00 6097. 

 50.01 0.2651E+05 2575.00 6051. 
31

 75.00 0.2715E+05 2600.00 6007. 

 100.00 0.2777E+05 2625.01 5963. 

 125.00 0.2831E+05 2650.00 5920. 

 150.01 0.2891E+05 2675.00 5878. 

 174.99 0.2949E+05 2700.00 5836. 

 200.00 0.3006E+05 2725.01 5795. 

 225.00 0.3060E+05 2749.99 5754. 

 250.00 0.3114E+05 2775.00 5714. 

 274.99 0.3165E+05 2800.00 5675. 

 300.00 0.3216E+05 2825.00 5636. 

 325.00 0.3265E+05 2849.99 5598. 

 350.00 0.3313E+05 2875.00 5561. 

 375.01 0.3360E+05 2900.00 5524. 

 400.00 0.3406E+05 2925.00 5487. 

 425.00 0.2981E+05 2950.01 5451. 

 450.00 0.2683E+05 2975.00 5416. 

 475.01 0.2474E+05 3000.00 5381. 

 500.00 0.2316E+05 3025.00 5347. 

 525.00 0.2161E+05 3050.01 5313. 

 550.00 0.2061E+05 3075.00 5279. 

 575.01 0.1975E+05 3100.00 5246. 

 599.99 0.1897E+05 3125.00 5214. 

 625.00 0.1828E+05 3150.00 5181. 

 650.00 0.1765E+05 3174.99 5150. 

 675.00 0.1707E+05 3200.00 5118. 

 699.99 0.1654E+05 3225.00 5087. 

 725.00 0.1606E+05 3250.00 5057. 

 750.00 0.1561E+05 3274.99 5027. 

 775.00 0.1519E+05 3300.00 4997. 

 800.01 0.1480E+05 3325.00 4968. 

 825.00 0.1444E+05 3350.00 4939. 

 850.00 0.1409E+05 3375.01 4910. 

 875.00 0.1377E+05 3400.00 4882. 

 900.01 0.1347E+05 3425.00 4854. 

 924.99 0.1318E+05 3450.00 4826. 

 950.00 0.1290E+05 3475.01 4799. 

 975.00 0.1264E+05 3499.99 4772. 

 1000.00 0.1240E+05 3525.00 4745. 

 1024.99 0.1216E+05 3550.00 4719. 

 1050.00 0.1194E+05 3575.00 4693. 

 1075.00 0.1172E+05 3599.99 4667. 

 1100.00 0.1152E+05 3625.00 4642. 

 1125.01 0.1132E+05 3650.00 4617. 

 1150.00 0.1113E+05 3675.00 4592. 

 1175.00 0.1095E+05 3700.01 4568. 

 1200.00 0.1078E+05 3725.00 4543. 

 1225.01 0.1061E+05 3750.00 4519. 

 1250.00 0.1045E+05 3775.00 4496. 

 1275.00 0.1029E+05 3800.01 4472. 

 1300.00 0.1014E+05 3825.00 4449. 

 1325.01 9998. 3850.00 4426. 

 1349.99 9858. 3875.00 4403. 

 1375.00 9723. 3900.00 4381. 

 1400.00 9591. 3924.99 4359. 

 1425.00 9464. 3950.00 4337. 

 1449.99 9340. 3975.00 4315. 
32

 1475.00 9220. 4000.00 4293. 

 1500.00 9105. 4024.99 4272. 

 1525.00 8992. 4050.00 4251. 

 1550.01 8881. 4075.00 4230. 

 1575.00 8775. 4100.00 4209. 

 1600.00 8672. 4125.01 4189. 

 1625.00 8571. 4150.00 4169. 

 1650.01 8474. 4175.00 4147. 

 1674.99 8378. 4200.00 4127. 

 1700.00 8285. 4225.01 4108. 

 1725.00 8195. 4249.99 4088. 

 1750.00 8107. 4275.00 4069. 

 1774.99 8020. 4300.00 4050. 

 1800.00 7936. 4325.00 4031. 

 1825.00 7854. 4349.99 4015. 

 1850.00 7774. 4375.00 3996. 

 1875.01 7696. 4400.00 3978. 

 1900.00 7619. 4425.00 3960. 

 1925.00 7544. 4450.01 3942. 

 1950.00 7471. 4475.00 3924. 

 1975.01 7399. 4500.00 3906. 

 1999.99 7330. 4525.00 3889. 

 2025.00 7264. 4550.01 3872. 

 2050.00 7197. 4575.00 3854. 

 2075.00 7130. 4600.00 3837. 

 2099.99 7067. 4625.00 3820. 

 2125.00 7004. 4650.00 3804. 

 2150.00 6942. 4674.99 3787. 

 2175.00 6881. 4700.00 3771. 

 2199.99 6822. 4725.00 3754. 

 2225.00 6764. 4750.00 3738. 

 2250.00 6706. 4774.99 3722. 

 2275.00 6650. 4800.00 3706. 

 2300.01 6595. 4825.00 3691. 

 2325.00 6541. 4850.00 3675. 

 2350.00 6488. 4875.01 3660. 

 2375.00 6436. 4900.00 3644. 

 2400.01 6386. 4925.00 3629. 

 2424.99 6335. 4950.00 3614. 

 2450.00 6285. 4975.01 3599. 

 2475.00 6238. 4999.99 3584. 

 2500.00 6190. 

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

 ********************** AERSCREEN MAXIMUM IMPACT SUMMARY ********************* 

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

 3-hour, 8-hour, and 24-hour scaled 

 concentrations are equal to the 1-hour concentration as referenced in 

 SCREENING PROCEDURES FOR ESTIMATING THE AIR QUALITY 

 IMPACT OF STATIONARY SOURCES, REVISED (Section 4.5.4) 

 Report number EPA-454/R-92-019 

 http://www.epa.gov/scram001/guidance_permit.htm 

 under Screening Guidance 
33

 MAXIMUM SCALED SCALED SCALED SCALED 

 1-HOUR 3-HOUR 8-HOUR 24-HOUR ANNUAL 

 CALCULATION CONC CONC CONC CONC CONC 

 PROCEDURE (ug/m3) (ug/m3) (ug/m3) (ug/m3) (ug/m3) 

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

 FLAT TERRAIN 0.3407E+05 0.3407E+05 0.3407E+05 0.3407E+05 N/A 

 DISTANCE FROM SOURCE 401.00 meters 

 IMPACT AT THE 

 AMBIENT BOUNDARY 0.2516E+05 0.2516E+05 0.2516E+05 0.2516E+05 N/A 

 DISTANCE FROM SOURCE 1.00 meters
APPENDIX D: SUMMARY OF LABELED USES OF EPTC TO BE ASSESSED IN RISK ASSESSMENT

Granular Formulation Uses 

Site Application 

Method Type 

A. I. Max App Rate (lb/A) 

Max # Apps @ Max Rate 

Minimum Retreatment Interval 

Max Dose/Year (lb/A) 

Application Method Equipment 

Application Method Timing 

Allowable Geographic Areas 

DisallowGeograpAreas 

AGRICULTURAL FALLOW IDLELAND CONSERVATION RESERVE 

Soil incorporated treatment. 

6.0 NS NS NS Soil

incorporation/ injection

equipment.

Preplant. NS NS 

ALFALFA CLOVER LESPEDEZA TREFOIL 

Broadcast. 3.0 NS 30 d 12 Aircraft. Established 

plantings. 

NS NS 

Ground. Established 

plantings. 

NS NS 

Soil incorporated treatment. 

4.0 NS NS NS Soil 

incorporation / injection equipment. 

Preplant. Western, Pacific 

Northwest, Northern 

NS 

3.0 NS 30 d 12 Sprinkler or 

Center Pivot Irrigation. 

Established plantings. 

NS NS 

NS NS Ground. Preplant. NS NS 

BEANS Soil incorporated 

treatment. 

4.0 NS NS NS Soil 

incorporation / injection equipment. 

At planting. Northern, Pacific 

Northwest 

NS 

Postplant. Northern, Pacific 

Northwest 

NS 

Preplant. Northern, Pacific 

Northwest 

NS 

BEANS, DRIED-TYPE 

Soil incorporated treatment. 

4.5 NS NS NS Soil 

incorporation / injection equipment. 

Fall. Minnesota, 

North Dakota 

NS 

CONIFERS (PLANTATIONS/NURSERIES) 

Soil incorporated treatment. 

6.0 NS NS NS Soil

incorporation/ injection

equipment.

Establishedplantings.

NS NS 

Preplant. NS NS 

CORN field, sweet, (SILAGE) 

Soil incorporated treatment. 

3.0 NS NS NS Soil

incorporation/ injection

equipment.

Preemergence. Specific area

(refer to the

issuesreport),Southeast,Northern

NS 
35

Site Application 

Method Type 

A. I. Max App Rate (lb/A) 

Max # Apps @ Max Rate 

Minimum Retreatment Interval 

Max Dose/Year (lb/A) 

Application Method Equipment 

Application Method Timing 

Allowable Geographic Areas 

DisallowGeograpAreas 

GRAPEFRUIT, ORANGE 

Soil incorporated treatment. 

6.0 NS NS NS Soil 

incorporation / injection equipment. 

Nonbearing nursery stock. 

NS NS 

POTATO, WHITE/IRISH Soil incorporated 

treatment. 

6.0 NS NS NS Soil 

incorporation / injection equipment. 

Drag-off. Northern, Pacific 

Northwest 

NS 

Preplant. Northern, Pacific 

Northwest 

NS 

3.0 NS NS NS Granule 

applicator. 

Drag-off. NS NS 

Layby. Southwest, 

Western, Southeast 

NS 

Preplant. Southwest, 

Western, Southeast 

NS 

SAFFLOWER (UNSPECIFIED) 

Soil incorporated treatment. 

3.0 NS NS NS Soil

incorporation/ injection

equipment.

Preplant. NS NS 

SUGAR BEET Soil incorporated 

treatment. 

4.5 NS NS NS Soil

incorporation/ injection

equipment.

Fall. Minnesota,North

Dakota

NS 

SUNFLOWER Soil incorporated 

treatment. 

4.5 NS NS NS Soil

incorporation/ injection

equipment.

Fall. Minnesota,North

Dakota

NS 
36

Emulsifiable Concentrate Formulations 

Site Application 

Method Type 

A. I. Max App Rate (lb/A) 

Max # Apps @ Max Rate 

Minimum Retreatment Interval 

Max Dose/Year (lb/A) 

Application Method Equipment 

Application Method Timing 

Allowable Geographic Areas 

DisallowGeograpc Areas 

AGRICULTURAL FALLOW IDLELAND CONSERVATION RESERVE 

Soil incorporated treatment. 

6.1 NS NS NS Soil 

incorporation / injection equipment. 

Preplant. NS NS 

ALFALFA Chemigatio

n. 

4.0 1 NS NS Sprinkler or 

Center Pivot Irrigation. 

Early fall. Pacific 

Northwest 

NS 

Late summer. 

Pacific Northwest 

NS 

Seedling stage. 

Western NS 

NS NS NS Sprinkler or 

Center Pivot Irrigation. 

Early fall. Pacific 

Northwest 

NS 

Established plantings. 

Pacific Northwest 

NS 

Late summer. 

Pacific Northwest 

NS 

Postplant. Western, Pacific 

Northwest 

NS 

3.9 NS NS NS Sprinkler or 

Center Pivot Irrigation. 

Early fall. Pacific 

Northwest 

NS 

Late summer. 

Pacific Northwest 

NS 

Postplant. NS NS Seedling stage. 

Western NS 

3.1 1 NS NS Sprinkler or 

Center Pivot Irrigation. 

Early summer. 

Pacific Northwest 

NS 

Established plantings. 

Southwest, Northern, Pacific Northwest, Western 

NS 

Spring. Pacific 

Northwest 

NS 

NS NS NS Sprinkler or 

Center Pivot 

Early summer. 

Pacific Northwest 

NS 
37

Site Application 

Method Type 

A. I. Max App Rate (lb/A) 

Max # Apps @ Max Rate 

Minimum Retreatment Interval 

Max Dose/Year (lb/A) 

Application Method Equipment 

Application Method Timing 

Allowable Geographic Areas 

DisallowGeograpc Areas 

Irrigation. 

Established plantings. 

Northern, Southwest 

NS 

Southwest, Northern, Pacific Northwest, Western 

NS 

Spring. Pacific 

Northwest 

NS 

12.3 Sprinkler or 

Center Pivot Irrigation. 

Established plantings. 

Western NS 

3.0 NS NS 12.2 Sprinkler or 

Center Pivot Irrigation. 

Established plantings. 

NS NS 

Soil incorporated treatment. 

4.0 1 NS NS Soil 

incorporation / injection equipment. 

Preplant. Western, Pacific 

Northwest, Northern 

NS 

NS NS NS Soil 

incorporation / injection equipment. 

Preplant. Western, 

Northern 

NS 

3.9 NS NS NS Soil 

incorporation / injection equipment. 

Preplant. Western, Pacific 

Northwest, Northern 

NS 

NS NS 

3.7 NS NS NS Ground. Preplant. Pacific 

Northwest 

NS 

3.1 1 NS NS Ground. Preplant. Southeast, 

Southwest 

NS 

NS NS NS Ground. Preplant. Southeast, 

Southwest 

NS 

Ground Spray. 

Preplant. Southeast, 

Southwest 

NS 
38

Site Application 

Method Type 

A. I. Max App Rate (lb/A) 

Max # Apps @ Max Rate 

Minimum Retreatment Interval 

Max Dose/Year (lb/A) 

Application Method Equipment 

Application Method Timing 

Allowable Geographic Areas 

DisallowGeograpc Areas 

ALMOND Chemigatio

n. 

3.1 2 NS 6.1 Sprinkler or 

Center Pivot Irrigation. 

Postemergence. 

Western NS 

6.2 Sprinkler or 

Center Pivot Irrigation. 

Postemergence. 

Western NS 

BEANS, DRIED-TYPE; FRESH 

Broadcast. 3.1 1 NS NS Soil 

incorporation / injection equipment. 

At planting. Western, Pacific 

Northwest, Southwest 

NS 

Preplant. Western, Pacific 

Northwest, Southwest 

NS 

NS NS 6.1 Ground. Preplant. Southeast NS 

6.2 Soil 

incorporation / injection equipment. 

Preplant. Southeast NS 

7 Soil 

incorporation / injection equipment. 

At planting. Western NS 

Layby. Western NS Preplant. Western NS 

7.9 Soil 

incorporation / injection equipment. 

At planting. Pacific 

Northwest 

NS 

Layby. Pacific 

Northwest 

NS 

Preplant. Pacific 

Northwest 

NS 

Chemigation. 

4.0 1 NS NS Sprinkler or 

Center Pivot Irrigation. 

Preplant. Pacific 

Northwest 

NS 

NS NS 7.9 Sprinkler or 

Center Pivot Irrigation. 

Postplant. Pacific 

Northwest 

NS 

Preplant. Pacific 

Northwest 

NS 
39

Site Application 

Method Type 

A. I. Max App Rate (lb/A) 

Max # Apps @ Max Rate 

Minimum Retreatment Interval 

Max Dose/Year (lb/A) 

Application Method Equipment 

Application Method Timing 

Allowable Geographic Areas 

DisallowGeograpc Areas 

Directed spray. 

4.0 1 NS NS Ground. Postemergen

ce. 

Western, Pacific Northwest, Northern 

NS 

NS NS 7 Soil 

incorporation / injection equipment. 

Layby. Western NS 

7.9 Ground. Layby. Pacific 

Northwest 

NS 

8.6 Ground 

Spray. 

Layby. Northern NS 

Soil band treatment. 

2.0 NS NS 6.1 Ground 

Spray. 

Plant bed. Southeast NS 

Preplant. Southeast NS 

6.2 Soil 

incorporation / injection equipment. 

Preplant. Southeast NS 

7.8 Soil 

incorporation / injection equipment. 

Preplant. Southeast NS 

Soil incorporated treatment. 

4.0 1 NS NS Soil 

incorporation / injection equipment. 

Preplant. Northern, Pacific 

Northwest 

NS 

NS NS 7.9 Ground. Preplant. Pacific 

Northwest 

NS 

8.6 Ground. At planting. Northern NS 

Soil injection treatment. 

3.1 NS NS 6.2 Ground. At planting. Southwest NS 

Preplant. Southwest NS 

7 Soil 

incorporation / injection equipment. 

At planting. Western NS 
40

Site Application 

Method Type 

A. I. Max App Rate (lb/A) 

Max # Apps @ Max Rate 

Minimum Retreatment Interval 

Max Dose/Year (lb/A) 

Application Method Equipment 

Application Method Timing 

Allowable Geographic Areas 

DisallowGeograpc Areas 

Preplant. Western NS 

7.9 Soil 

incorporation / injection equipment. 

At planting. Pacific 

Northwest 

NS 

Preplant. Pacific 

Northwest 

NS 

CARROT (INCLUDING TOPS) 

Soil incorporated treatment. 

3.0 NS NS 9.1 Sprinkler or 

Center Pivot Irrigation. 

Germination. Specific County 

(refer to the issues report) 

NS 

Preplant. Specific County 

(refer to the issues report) 

NS 

CASTOR BEAN Soil 

incorporated treatment. 

2.0 1 NS NS Soil 

incorporation / injection equipment. 

Preemergence. 

Northern NS 

NS NS NS Soil 

incorporation / injection equipment. 

Postplant. Northern NS 

7.8 Soil 

incorporation / injection equipment. 

Postplant. Northern NS 

CLOVER, TREFOIL, LESPEDEZA 

Chemigation. 

3.9 NS NS NS Sprinkler or 

Center Pivot Irrigation. 

Postplant. NS NS 

Soil incorporated treatment. 

4.0 1 NS NS Soil 

incorporation / injection equipment. 

Preplant. Western, Pacific 

Northwest, Northern 

NS 
41

Site Application 

Method Type 

A. I. Max App Rate (lb/A) 

Max # Apps @ Max Rate 

Minimum Retreatment Interval 

Max Dose/Year (lb/A) 

Application Method Equipment 

Application Method Timing 

Allowable Geographic Areas 

DisallowGeograpc Areas 

NS NS NS Soil 

incorporation / injection equipment. 

Preplant. Western,Norther

n 

NS 

CONIFERS(PLANTATIONS/NURSERIES)

Soilincorporatedtreatment.

6.0 NS NS NS Soil

incorporation/ injection

equipment.

Preplant. NS NS 

CORN: FIELD, POP, SWEET, SILAGE, (UNSPECIFIED) 

Broadcast. 6.1 NS NS NS Mixer 

(mechanical). 

Preplant. Eastern 

States,Central States,Western 

Arizona,Secific County (refer to tissues report) 

Soil band treatment. 

6.1 NS NS NS Ground 

Spray. 

Preplant. Eastern 

States,Central States,Western 

Arizona,Secific County (refer to tissues report) 

Soil incorporated treatment. 

6.1 NS NS NS Soil 

incorporation / injection equipment. 

Preplant. Eastern 

States,Central States,Western 

Arizona,Secific County (refer to tissues report) 

Sprinkler or Center Pivot Irrigation. 

Postplant. Specific County 

(refer to the issues report) 

NS 

Preplant. Eastern 

States,Central States,Western 

Arizona,Secific County (refer to tissues report) 

COTTON (UNSPECIFIED) 

Broadcast. 2.0 NS NS NS Soil 

incorporation / injection equipment. 

Established plantings. 

Specific area (refer to the issues report),Southwest,Southeast 

NS 

Soil band treatment. 

2.0 1 NS NS Soil 

incorporation 

Postemergence. 

Specific area (refer to the 

NS 
42

Site Application 

Method Type 

A. I. Max App Rate (lb/A) 

Max # Apps @ Max Rate 

Minimum Retreatment Interval 

Max Dose/Year (lb/A) 

Application Method Equipment 

Application Method Timing 

Allowable Geographic Areas 

DisallowGeograpc Areas 

/ injection equipment. 

issues report),Southwest,Southeast 

Soil incorporated treatment. 

2.0 NS NS NS Soil 

incorporation / injection equipment. 

Established plantings. 

Specific area (refer to the issues report),Southwest,Southeast 

NS 

GRAPEFRUIT Chemigatio

n. 

3.1 1 NS NS Sprinkler or 

Center Pivot Irrigation. 

Bearing. Southwest,West

ern,Southeast 

NS 

Directed spray. 

6.2 1 NS NS Soil 

incorporation / injection equipment. 

Nonbearing. Southwest,West

ern,Southeast 

NS 

NS NS NS Soil 

incorporation / injection equipment. 

Nonbearing nurserystock. 

Southwest,Western,Southeast 

NS 

Nonbearing. Southwest,West

ern,Southeast 

NS 

LEMON Chemigatio

n. 

3.1 1 NS NS Sprinkler or 

Center Pivot Irrigation. 

Bearing. Western NS 

Directed spray. 

6.2 1 NS NS Soil 

incorporation / injection equipment. 

Nonbearing. Western NS 

NS NS NS Soil 

incorporation / injection equipment. 

Nonbearing nurserystock. 

Western NS 

Nonbearing. Western NS 

ORANGE Chemigation. 3.1 1 NS NS Sprinkler or

Center PivotIrrigation.

Bearing. Southwest,Wester

n,Southeast

NS 

Directedspray.

6.2 1 NS NS Soil

incorporation/ injectionequipment.

Nonbearing. Southwest,Wester

n,Southeast

NS 
43

Site Application 

Method Type 

A. I. Max App Rate (lb/A) 

Max # Apps @ Max Rate 

Minimum Retreatment Interval 

Max Dose/Year (lb/A) 

Application Method Equipment 

Application Method Timing 

Allowable Geographic Areas 

DisallowGeograpc Areas 

ORNAMENTAL AND/ORSHADE TREES;

ORNAMENTAL WOODY

SHRUBS AND VINES

Broadcast. 6.2 NS NS NS Hose Posttransplant

.

NS NS 

Pretransplant. NS NS Spring. NS NS 

Ground Spray. Posttransplant

.

NS NS 

Pretransplant. NS NS Spring. NS NS 

Soil band

treatment.

6.1 NS NS NS Ground Spray. Posttransplant

.

NS NS 

Pretransplant. NS NS Spring. NS NS 

Soilincorporatedtreatment.

14.8 NS NS NS Soil

incorporation/ injection

equipment.

Preplant. NS NS 

ORNAMENTAL GROUND

COVER ORNAMENTAL

HERBACEOUS PLANTS

Broadcast. 5.1 NS NS NS Hose Posttransplant

.

NS NS 

Spring. NS NS 

Ground Spray. Posttransplant

.

NS NS 

Spring. NS NS 

Soil band

treatment.

5.0 NS NS NS Ground Spray. Posttransplant

.

NS NS 

Spring. NS NS 
44

Site Application 

Method Type 

A. I. Max App Rate (lb/A) 

Max # Apps @ Max Rate 

Minimum Retreatment Interval 

Max Dose/Year (lb/A) 

Application Method Equipment 

Application Method Timing 

Allowable Geographic Areas 

DisallowGeograpc Areas 

Soilincorporatedtreatment.

14.1 NS NS NS Soil

incorporation/ injection

equipment.

Preplant. NS NS 

PINE SEEDLINGS Soil

incorporatedtreatment.

6.2 NS NS NS Soil

incorporation/ injection

equipment.

Beforeseeding.

Southeast,Southwest

NS 

POTATO, WHITE/IRISH Broadcast. 1.5 1 NS NS Ground. Postplant. Southeast,Southw

est

NS 

NS NS 3.1 Ground. Postplant. Southeast NS 

Soilincorporation/ injectionequipment.

Postplant. Southeast NS 

Chemigation. 6.2 1 NS NS Sprinkler or

Center Pivot

Irrigation.

Postemergence.

Pacific Northwest NS 

NS NS 6.2 Sprinkler or

Center Pivot

Irrigation.

Postemergence.

Pacific Northwest NS 

6.1 NS NS 12.2 Sprinkler or

Center Pivot

Irrigation.

Postemergence.

NS NS 

12.3 Sprinkler or

Center PivotIrrigation.

Postemergence.

Pacific Northwest NS 

Soil band

treatment.

7.8 NS NS 12.3 Soil

incorporation/ injection

equipment.

Preplant. NS NS 

Ground Spray. Postplant. NS NS 

Soilincorporatedtreatment.

7.8 NS NS 12.3 Soil

incorporation/ injection

equipment.

Preplant. NS NS 
45

Site Application 

Method Type 

A. I. Max App Rate (lb/A) 

Max # Apps @ Max Rate 

Minimum Retreatment Interval 

Max Dose/Year (lb/A) 

Application Method Equipment 

Application Method Timing 

Allowable Geographic Areas 

DisallowGeograpc Areas 

Sprinkler orCenter PivotIrrigation.

Postplant. Specific County

(refer to the issues

report)

NS 

SAFFLOWER(UNSPECIFIED)

Chemigation. 3.0 NS NS NS Sprinkler or

Center PivotIrrigation.

Postemergence.

Arizona NS 

Soilincorporatedtreatment.

3.1 NS NS NS Soil

incorporation/ injection

equipment.

Preplant. Western, Pacific

Northwest,Northern

NS 

SUGAR BEET Broadcast. 3.1 NS NS NS Soil

incorporation/ injection

equipment.

Postemergence.

Western, Pacific

Northwest,Northern

NS 

Chemigation. 3.1 2 NS NS Sprinkler or

Center Pivot

Irrigation.

Postemergence.

Western, Pacific

Northwest,Northern

NS 

Soil band

treatment.

3.1 NS NS 3.1 Soil

incorporation/ injection

equipment.

Postemergence.

Western, Pacific

Northwest,Northern

NS 

Soilincorporatedtreatment.

4.6 NS NS NS Soil

incorporation/ injection

equipment.

Fall. Minnesota, North

Dakota

NS 

3.1 NS NS NS Soil

incorporation

/ injectionequipment.

Postemergence.

Western, Pacific

Northwest,Northern

NS 

Soil injectiontreatment.

3.0 NS NS NS Soil

incorporation/ injection

equipment.

Postemergence.

Southwest,Northern, Pacific

Northwest,Western

NS 

SUNFLOWER Chemigation. 3.0 NS NS NS Sprinkler or

Center PivotIrrigation.

Postemergence.

NS NS 

Soilincorporated

4.6 NS NS NS Soil

incorporation

Fall. Minnesota, North

Dakota

NS 
46

Site Application 

Method Type 

A. I. Max App Rate (lb/A) 

Max # Apps @ Max Rate 

Minimum Retreatment Interval 

Max Dose/Year (lb/A) 

Application Method Equipment 

Application Method Timing 

Allowable Geographic Areas 

DisallowGeograpc Areas 

treatment. / injection

equipment.

Preplant (Fall). NS NS 

TANGERINES Chemigation. 3.1 1 NS NS Sprinkler or

Center PivotIrrigation.

Bearing. Southwest,

Western,Southeast

NS 

TOMATO Broadcast. 3.0 NS NS NS Ground Spray. Pretransplant. Florida NS 

Soil band

treatment.

3.1 1 NS NS Soil

incorporation/ injection

equipment.

Postemergence.

Specific County

(refer to the issues

report)

NS 

NS NS NS Soil

incorporation/ injectionequipment.

Layby. Specific County

(refer to the issues

report)

NS 

3.0 NS NS NS Ground Spray. Layby. Specific County

(refer to the issues

report)

NS 

Soilincorporatedtreatment.

3.1 NS NS NS Soil

incorporation/ injection

equipment.

Layby. Specific County

(refer to the issues

report)

NS 

Soiltreatment(surface).

3.0 NS NS NS Ground Spray. Layby. Specific County

(refer to the issues

report)

NS 

Transplanted Watermelon Broadcast,

Band orsubsurface

3.5 NS NS NS Ground spray Pretransplant All regions NS 

Chemigation 3.5 NS NS NS Sprinkler or

Center PivotIrrigation.

Pretransplant All Regions NS 

WALNUT(ENGLISH/BLACK)

Chemigation. 3.1 1 NS NS Sprinkler or

Center PivotIrrigation.

Establishedplantings.

Western, Pacific

Northwest

NS 

NS NS NS Sprinkler or

Center Pivot

Irrigation.

Establishedplantings.

Western, Pacific

Northwest

NS 
47

APPENDIX E: AEROBIC METABOLISM HALF-LIFE CALCULATION USING R-TOOL