Page 1 of 13

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON D.C., 20460

OFFICE OF CHEMICAL SAFETY

AND POLLUTION PREVENTION

 

PC Code: 122101

Date: February 2, 2011

DP Barcodes: 383339, 383347

MEMORANDUM

SUBJECT: Potential Impacts to Ecological Risk Assessment of Azoxystrobin as a Result of 

the Proposed Label Change to Include the Spray Volume from Aerial 

Applications to 0.5 Gallons Per Acre on Soybeans and Wheat

TO: Shaja Joyner, Risk Manager

Shaunta Hill, Risk Manager Reviewer

Registration Division (7505P)

FROM: Reuben Baris, Environmental Scientist

Stephen Carey, Biologist

Environmental Risk Branch VI

Environmental Fate and Effects Division (7507P)

REVIEWED

BY: William P. Eckel, Ph.D, Senior Science Advisor

Environmental Risk Branch VI

Environmental Fate and Effects Division (7507P)

APPROVED

BY: Mark Corbin, Branch Chief

Environmental Risk Branch VI

Environmental Fate and Effects Division (7507P)

The Environmental Fate and Effects Division (EFED) has completed its review of the impact of 

the proposed label change to allow ultra-low volume (ULV) applications of azoxystrobin to 

soybeans and wheat via aerial applications using the formulated products QuiltTM XCEL (EPA 

Reg. No. 100-1324) and Quilt® (EPA Reg. No. 100-1178). QUILTTM XCEL and QUILT®

fungicides contains two active ingredients (a.i.), azoxystrobin (CAS No. 131860-33-8) and 

propiconazole (CAS No. 60207-90-1). This document addresses the ecological risks associated 

with the addition of ULV to the label as proposed under the Section 3 new use of azoxystrobin 

on soybean and wheat. Propiconazole (PC 122101) will be addressed in a separate assessment. 
Page 2 of 13

The maximum single ULV application rate for soybean and wheat evaluated in this assessment is 

0.1 to 0.194 lbs a.i./A for QUILT® and QUILTTM Xcel, respectively (0.2 to 0.38 lbs 

a.i./A/season), with a minimum flow rate of 0.5 gallons per acre, and minimum reapplication 

interval of 14 days. For the proposed label change, including the addition of 0.5 gallon per acre 

spray volume application for soybeans and wheat, the estimated risk will be less than previously 

assessed by EFED in D380859 for a corn ULV use. In the previous assessment, the taxonomic 

groups’ RQs that exceeded the Levels of Concern (LOC) for risk resulting from azoxystrobin 

ULV applications to corn were aquatic organisms and aquatic non-vascular plants. 

Consequently, the RQs for the proposed action are lower than the RQs for corn use; therefore, 

two taxonomic groups (freshwater fish and aquatic non-vascular plants) were assessed to be 

below the LOC when ULV application is used on soybeans and wheat (compared to ULV 

applications to corn). The invertebrates, both freshwater and estuarine/marine, remain at risk 

when exposed to ULV applications that are treated in soybean, wheat, or corn fields (as assessed 

in this document and in D380859).

Previous EFED drinking water and ecological risk assessments used the default spray drift 

assumption of 5% (drift fraction) for aerial applications. Most recently (September 2010, 

D380859), EFED completed a combined drinking water and ecological risk assessment that 

investigated exposure from ULV sprays to corn (application rate of 0.129 lbs a.i./A, 2.0 lbs 

a.i./A/yr; D380859). EFED employed AgDRIFT (version 2.01) modeling to estimate potential 

changes in offsite deposition of azoxystrobin at the edge of field that may result from use of 

lower spray volume (0.5 GPA is consider to be an ultra low volume (ULV) application), because 

the default spray drift assumptions tend to underestimate off-site movement of the chemical

when applied at ultra low volumes. The resulting spray drift fraction was input into 

PRZM/EXAMS to provide estimated environmental concentrations (EECs) for use in ecological 

risk assessments and drinking water assessments. Risk quotients (RQs) to terrestrial and aquatic 

organisms resulting from the maximum application for soybeans and wheat (0.194 lbs a.i./A, 1.5 

lbs a.i./A/yr, for soybeans) are presented below in Table 1. RQs from the corn ULV uses are 

provided (D380859) as well for comparison. 

Conclusions - Potential Risk to Non-target Wildlife 

Based on all available data, potential acute and chronic risks from the proposed new uses of 

azoxystrobin on soybean and wheat are expected for freshwater and estuarine/marine 

invertebrates. The potential for risks to birds, terrestrial-phase amphibians, reptiles, mammals, 

insects, fish, terrestrial and aquatic plants are anticipated to be minimal. 

 

Table 1 presents the Risk Quotients (RQs) and use patterns used to determine the potential risks 

to terrestrial and aquatic wildlife and plants exposed to azoxystrobin. 
Page 3 of 13

Table 1. Summary of Risk Quotient Calculation for Azoxystrobin Exposures to Terrestrial and 

Aquatic Organisms and Plants.*

Species Azoxystrobin Use Pattern and RQs Summary for Soybean and Wheat Use

(Including Corn Use).

Soybean and Wheat ULV Corn ULV

Aquatic Organisms and Plants

Fish (and aquatic-phase 

amphibians)

Acute RQ: 0.04

Chronic RQ: <0.1

Acute RQ: 0.054

Chronic RQ: <0.1

Freshwater 

Invertebrates

Acute RQ: 0.07

Chronic RQ: 0.3

Acute RQ: 0.098

Chronic RQ: 0.6

Marine/estuarine Fish Acute RQ: 0.03

Chronic RQ: no data

Acute RQ: 0.04

Chronic RQs: no data

Marine/estuarine 

Invertebrates

Acute RQ: 0.32

Chronic RQ: 1.9

Acute RQ: 0.45

Chronic RQ: 2.6

Aquatic Vascular Plants Non-Listed Plant RQ: <0.1 

Listed Plant RQ: <0.1

Non-Listed Plant RQs: <0.1 

Listed Plant RQs: <0.1

Aquatic Non-Vascular 

Plants

Non-Listed Plant RQ: 0.4

Listed Plant RQ: 0.9

Non-Listed Plant RQ: 0.5

Listed Plant RQ: 1.3

Terrestrial Animals and Plants 

Birds (and terrestrialphase amphibians and 

reptiles)

Not assessed; RQs anticipated to be 

below the LOC based on results of 

corn ULV applications with higher 

EECs.

Acute RQs: <0.011

Chronic RQs: <0.1 – 0.21

Mammals Acute RQs: <0.011

Chronic RQs: <0.1 – 0.71

Terrestrial Plants Non-Listed Plant RQs: N.R.2

Listed Plant RQs: N.R.

* Bold entries indicate LOC exceedance or concern

1 Corn ULV application risk quotients (current uses) for terrestrial animals and plants were derived from 

D380859

2 N.R. – not reported or not assessed at that time

Conclusions- Listed Species

Based on estimated maximum application rates, exposure levels and available effects data, 

azoxystrobin used as a fungicide for prevention and control of certain diseases in soybean and 

wheat indicates direct effects LOC exceedances for freshwater and estuarine/marine 

invertebrates. Such findings suggest a potential concern for indirect effects to listed animal and 

plant species with both narrow (i.e., species that are obligates or have very specific habitat or 

feeding requirements) and general dependencies (i.e., cover type requirements) on aquatic 

invertebrates as a resource or important habitat component. Therefore, there is a potential for 

indirect effects to all animal and plant taxonomic groups (i.e., mammal, bird, amphibian, reptile, 

fish, crustacean, mollusks, and gastropods) that depend on those aquatic invertebrates as food 

resources to survive, grow, and reproduce and are presented in Table 2.
Page 4 of 13

Table 2. Potential Listed Species Risks Associated with Direct or Indirect Effects due to 

the Use of Azoxystrobin on Soybean and Wheat. 

Listed Taxon Direct Effects from 

Acute Exposures

Direct Effects from 

Chronic Exposures

Indirect Effects

Aquatic

Aquatic non-vascular plants No N/A No

Aquatic vascular plants No N/A No

Freshwater invertebrates Yes No Yes

Marine/estuarine 

invertebrates

Yes Yes Yes

Freshwater fish No No Yes

Marine/estuarine fish No No Yes

Aquatic-phase amphibians1 No No Yes

Terrestrial

Semi-aquatic plants -

monocots

No N/A No

Semi-aquatic plants - dicots No N/A No

Terrestrial plants – monocots No N/A No

Terrestrial plants - dicots No N/A No

Insects No N/A No

Birds No No Yes

Terrestrial-phase amphibians No No Yes

Reptiles No No Yes

Mammals No No Yes

N/A - indicates that this exposure route is not assessed. 1 Freshwater fish acts as a surrogate for aquatic-phase amphibians 2 Bird acts as a surrogate for terrestrial-phase amphibians

Modeling Approach for ULV Uses

Currently, EFED does not have approved methodology in place to assess the influence of ULV 

on ecological exposure assessments. It is anticipated that due to finer drop size spectrum and 

lower application volumes that the drift fraction will increase for ULV methods of application 

compared to other methods of application. The requested minimum spray volume is 0.5 gallons 

per acre with an oil carrier. The following modeling approach was used to estimate aquatic 

exposure concentrations from the addition of ULV applications using AgDRIFT. Two 

azoxystrobin applications of 0.194 lbs a.i./A with a 14-day reapplication interval were run with 

PRZM/EXAMS using the standard Missouri soybean scenario and the AgDRIFT drift fraction 

input to obtain aquatic EECs for the proposed ULV use for soybeans and wheat (Table 6).
Page 5 of 13

Estimate of ULV Drift Fraction

AgDrift Model (Version 2.01) with ASAE aerosol to very fine droplet size and Tier 2 aerial 

agricultural drift option was used to estimate drift. All parameters were default for the AgDrift 

ASAE aerosol to very fine drop size template with the exception of spray material. Spray 

material values were determined (in Table 3) and the calculation option implemented. The 

aquatic assessment was run for Tier 2 aerial application with the user selected water body option 

selected (EPA defined pond) for the aquatic assessment.

Table 3. Estimates of Spray Drift Fraction for ULV using AgDrift (Version 2.01)

Spray material: Maximum 

(fl.oz./A)

Quilt®

(7% ai)

QuiltTM Xcel

(13.5% ai)

Drift Fraction

[fraction of applied] 

Non-Volatile Rate (lb/A)1: 21 Max. fl.oz./A 0.328 0.328

Active Rate (lb/A)2: 0.022962 0.044283

Spray Volume Rate (gal/A) 0.5 0.5

Carrier Oil Oil

Aquatic 0.503 (or 50%) 1

Non-volatile rate = (14 fl oz/A ÷128 fl oz/gal) ÷ 0.5 gallons/A [lbs/A] 2 Active rate = 0.328 lb/A * fraction a.i. (0.07) = 0.02296 3 Active rate = 0.328 lb/A * fraction a.i. (0.135) = 0.04428

In addition, the drift fraction in this assessment is higher than previously estimated for ULV 

applications to corn (50% vs. 27%, respectively). This is due in large part to the selection of the 

droplet size distribution (DSD); the corn ULV assessment used “very fine to fine” DSD, while 

this assessment selected “aerosol to very fine” DSD. The aerosol to very fine DSD better 

represents the spray volume for the ULV applications.

PRZM/EXAMS Model Inputs

Input parameters for aquatic exposure modeling (PRZM-EXAMS) were derived from previous 

risk assessments. Model input parameters are presented below in Table 4. 

The chemical application method (CAM) used for PRZM modeling is 2, which is interception 

based upon canopy and default soil incorporation depth of 4 cm (Table 4). The spray drift 

fraction estimated for the aquatic assessment is 0.503, calculated using AgDrift 2.01 considering

the application as ULV. 
Page 6 of 13

Table 4. Summary of Environmental Fate Parameters for Azoxystrobin and Values 

Used for PRZM/EXAMS Modeling.

Parameter Range Value Used Source

Solubility in water 6.7 mg/L @ pH 7; 20 oC 6.7 mg/L MRID 43678105

Vapor Pressure 8.2 x 10-13 torr 8.2 x 10-13 torr MRID 43678105

Hydrolysis t1⁄2 (at 25 °C) stable at pH5, 7, 9 0 days MRID 43678172

Aquatic Photolysis, t1⁄2

(half-life)

t1⁄2 = 11.1, 16.6, and 17.1 

days

23.23 (90th percent 

upper confidence bound 

on mean T1⁄2

MRID 43678173

Soil Photolysis DT50 = 11 days

t1⁄2 = 17.6 to 28.4 days. 

Not currently used in 

PRZM MRID 43678174

Aerobic Soil 

Metabolism, t1⁄2

72, 85, 164 days

mean = 107 days

std = 49.79

median = 85

90 percent upper bound 

on mean = 161.2 day

MRID 43678175,

44046801

Aerobic Aquatic 

Metabolism, t1⁄2

none available

2 x aerobic soil 

metabolism

2 x 161.2 = 322.2 days

EFED, 2009

Anaerobic Aquatic 

Metabolism, t1⁄2

50 to 59 days

(soil-water system)

62.3 days 90 % upper 

bound

MRID 43678175

(Supplemental)

Sorption Kd

2.1, 4.3, 6.0, 9.0, 12.0, 20.0, 

and 36.0 mL/g; mean = 

12.68 mL/g

12.68 mL/g MRID 43678178

MRID 43678181

Sorption Koc

300, 360, 710, 720, 760, 

1490, 1690 mL/goc; mean = 

841.25 mL/goc

Not used in assessment MRID 43678178

MRID 43678181

Spray Drift PRZM variable

Spray Drift (DRFT) 0.50 (ULV)1 EFED. 2009

Application Efficiency PRZM variable 0.95 (APPEFF) EFED. 2009

Foliar Wash-Off PRZM variable 0.5 (FEXTRC) EFED. 2009

CAM (chemical 

application method)

2 – interception on crop 

canopy (PRZM variable) ULV Label Directions

DEPI (depth of soil 

incorporation) Default by model 4 cm

1 Drift estimated with AgDrift Version (2.01), Tier II Aquatic Assessment (oil carrier), 10 mph wind speed.

Scenario Selection

The MS soybean scenario was used for the ULV assessment because it provides conservative 

estimates of runoff resulting from applications to soybeans (Tables 5 and 6). 

Table 5. Use (crop), Modeling Scenario, Meteorological File, Crop Emergence, 

Maturity and Harvest Dates, and Date of First Application.

Crop Scenario Met file Dates(mn-day):

Emergence/Maturity/Harvest 

Application date

(mm-dd)

Soybean

and Wheat MS soybean W03940.dvf 04-16/09-01/10-10 01-05
Page 7 of 13

Tier II PRZM/EXAMS Modeling

Tier II PRZM/EXAM modeling was conducted using the MS soybean scenario to estimate 

aquatic exposure resulting from applications to soybeans and wheat. PRZM/EXAMS results are 

summarized in Table 6. 

Table 6. Surface Water EECs for Aquatic Exposure using PRZM/EXAMS Resulting 

from the ULV Application of Azoxystrobin to Soybean and Wheat. 

Scenario Method Spray Drift

(Fraction)

Minimum 

Reapplicatio

n Interval 

(days)

Number and 

Application 

Rate

(lb a.i./A)

1 in 10 yr

Peak 

(μg/L)

21-day 

mean 

(μg/L)

60-day 

mean 

(μg/L)

MS soybean ULV1 0.52 14 23 @ 0.1944 18.8 17.9 16.6 1 ULV – Ultra-low volume application 2 ULV spray drift fraction estimated with AgDrift (Version 2.01)

3 Maximum number of applications at maximum rate proposed for application to wheat and soybean by ULV (42 fl oz 

product/A/season) 4

 Maximum single azoxystrobin application rate for soybean and wheat by ULV

Risk Characterization

For the proposed label change including the addition of 0.5 gallon per acre spray volume 

application for soybeans and wheat, the estimated risk will be less than previously assessed for 

corn ULV use by EFED in D380859. Consequently, the RQs for the proposed action are lower 

than the RQs for corn use; therefore, EFED does not expect that the proposed action will result in 

additional risk to terrestrial and aquatic organisms. With aquatic organisms and non-vascular 

plants potentially at risk in the previous assessment for corn ULV uses, results for the other

taxonomic groups that did not exceed the LOCs with higher RQs are not discussed in this 

assessment. To add ULV applications for soybean and wheat uses, this assessment focuses on 

aquatic organisms and non-vascular plants only. Tables 7, 8, and 9 compare the proposed action 

EECs and associated RQs with the previously assessed ULV applications to corn. Results of the

comparison with aquatic organisms and non-vascular plants indicate lower RQs for the proposed 

action; however, it is noted that as oppose to corn ULV use, for freshwater fish and aquatic nonvascular plants, there are no LOC exceedances for those taxonomic groups when exposed to 

azoxystrobin ULV applications in wheat and soybean fields. 
Page 8 of 13

Table 7. Tier II Risk Quotients for Freshwater Organisms for Proposed Azoxystrobin ULV uses 

on Soybeans and Wheat

Use

Corn

(#/lb a.i./A)

(Drift 

fraction)

PRZM

Scenario

Peak 

EEC

21D 

EEC

60D 

EEC

Freshwater Fish

(LC50 = 0.47 mg a.i./L ; 

NOAEC = 0.147 mg a.i./L) 

Freshwater Invertebrate

(EC50 = 0.26 mg a.i./L ; 

NOAEC = 0.044 mg a.i./L)

Acute Chronic Acute Chronic

ULV Applications on Soybeans (proposed action)

2 @ 0.194

(0.5) MS Soybean 18.8 17.9 16.6 0.04 <0.1 0.07 0.3

ULV Applications on Corn (D380859)

4 @ 0.129

(0.27) KS Corn 25.45 24.45 22.75 0.054 <0.1 0.098 0.6

Table 8. Tier II Risk Quotients for Estuarine/marine Organisms for Proposed Azoxystrobin 

ULV Uses on Soybeans and Wheat

Use

Corn

(#/lb a.i./A)

(Drift 

fraction)

PRZM

Scenario

Peak 

EEC

21D 

EEC

60D 

EEC

Marine/Estuarine Fish 

(LC50 = 0.67 mg a.i./L

NOAEC = no data)

Marine/Estuarine Invertebrate

(EC50 = 0.056 mg a.i./L;

NOAEC = 0.0095 mg a.i./L)

Acute Chronic Acute Chronic

ULV Applications on Soybeans (proposed action)

2 @ 0.194 

(0.5) MS Soybean 18.8 17.9 16.6 0.03 No data 0.32 1.9

ULV Applications on Corn (D380859)

4 @ 0.129 

(0.27) KS Corn 25.45 24.45 22.75 0.04 No data 0.45 2.6
Page 9 of 13

Table 9. Tier II Risk Quotients for Aquatic Plants for Proposed Azoxystrobin ULV Uses

on Soybeans and Wheat

Use

Corn

(#/lb a.i./A)

(Drift 

fraction)

PRZM 

Scenario

Peak EEC Vascular Aquatic Plant

(EC50 = 3.4 mg a.i./L

NOAEC = 0.8 mg a.i./L)

Non-Vascular Aquatic Plant

(EC50 = 0.049 mg a.i./L;

NOAEC = 0.02 mg a.i./L)

Non-target3 Listed4 Non-target5 Listed6

ULV Applications on Soybean (Proposed Action)

2 @ 0.194 

(0.5) MS Soybean 18.8 <0.1 <0.1 0.4 0.9

ULV Applications on Corn (D380859)

4 @ 0.129 

(0.27) KS Corn 25.45 <0.1 <0.1 0.5 1.3

Input data and model run information for PRZM/EXAMS and AgDRIFT are presented in 

Appendices A and B, respectively. Specific information on the effects endpoints can be found in 

D380859.
Page 10 of 13

Appendix A. PRZM/EXAMs Model input and Output Data

stored as MSsoy.out

Chemical: AZOXYSTROBIN

PRZM environment: MSsoybeanSTD.txt modified Tueday, 29 May 2007 at 12:58:06

EXAMS environment: pond298.exv modified Tueday, 26 August 2008 at 05:14:08

Metfile: w03940.dvf modified Tueday, 26 August 2008 at 05:14:14

Water segment concentrations (ppb)

Year Peak 96 hr 21 Day 60 Day 90 Day Yearly

1961 10.13 9.984 9.426 9.014 8.759 4.648

1962 13.2 13.03 12.4 11.19 10.45 6.757

1963 13.64 13.47 12.79 11.95 11.75 7.872

1964 14.54 14.36 13.75 12.61 11.92 8.313

1965 14.34 14.17 13.49 12.22 11.49 8.142

1966 18.28 18.18 17.58 15.99 14.98 9.844

1967 19.03 18.81 18.18 16.96 15.97 10.84

1968 17.24 17.06 16.75 15.35 14.38 10.03

1969 15.18 15 14.32 12.95 12.24 8.617

1970 14.97 14.79 14.12 12.82 12.08 8.337

1971 16.22 16.03 15.3 13.9 13.07 8.714

1972 15.52 15.33 14.62 13.23 12.46 8.318

1973 14.8 14.62 14.16 12.8 11.97 7.919

1974 13.89 13.72 13.07 12.61 11.84 8.028

1975 15.96 15.76 15.02 13.98 13.34 9.065

1976 17.33 17.14 16.63 15.74 14.91 9.993

1977 15.59 15.41 14.67 13.53 12.85 9.248

1978 17.28 17.08 16.42 14.89 13.93 9.221

1979 16.83 16.64 15.89 15.53 15.42 10.57

1980 18.8 18.59 17.97 16.34 15.22 10.35

1981 17.33 17.15 16.75 15.74 14.98 9.965

1982 15.65 15.47 14.77 14.24 14.04 10.01

1983 21.32 21.08 20.2 18.5 17.28 11.22

1984 17.11 16.92 16.4 15.05 14.29 10.12

1985 15.06 14.88 14.19 12.91 12.23 8.892

1986 17.74 17.53 16.83 15.64 14.74 9.598

1987 15.5 15.31 14.58 13.99 13.3 9.186

1988 14.88 14.7 14.02 12.63 11.94 8.469

1989 18.35 18.14 17.37 16.61 15.69 10.14

1990 16.73 16.54 15.96 14.59 13.65 9.398

Sorted results

Prob. Peak 96 hr 21 Day 60 Day 90 Day Yearly

0.032258064516129 21.32 21.08 20.2 18.5 17.28 11.22

0.0645161290322581 19.03 18.81 18.18 16.96 15.97 10.84

0.0967741935483871 18.8 18.59 17.97 16.61 15.69 10.57

0.129032258064516 18.35 18.18 17.58 16.34 15.42 10.35

0.161290322580645 18.28 18.14 17.37 15.99 15.22 10.14

0.193548387096774 17.74 17.53 16.83 15.74 14.98 10.12

0.225806451612903 17.33 17.15 16.75 15.74 14.98 10.03

0.258064516129032 17.33 17.14 16.75 15.64 14.91 10.01

0.290322580645161 17.28 17.08 16.63 15.53 14.74 9.993

0.32258064516129 17.24 17.06 16.42 15.35 14.38 9.965

0.354838709677419 17.11 16.92 16.4 15.05 14.29 9.844

0.387096774193548 16.83 16.64 15.96 14.89 14.04 9.598

0.419354838709677 16.73 16.54 15.89 14.59 13.93 9.398

0.451612903225806 16.22 16.03 15.3 14.24 13.65 9.248

0.483870967741936 15.96 15.76 15.02 13.99 13.34 9.221

0.516129032258065 15.65 15.47 14.77 13.98 13.3 9.186

0.548387096774194 15.59 15.41 14.67 13.9 13.07 9.065

0.580645161290323 15.52 15.33 14.62 13.53 12.85 8.892
Page 11 of 13

0.612903225806452 15.5 15.31 14.58 13.23 12.46 8.714

0.645161290322581 15.18 15 14.32 12.95 12.24 8.617

0.67741935483871 15.06 14.88 14.19 12.91 12.23 8.469

0.709677419354839 14.97 14.79 14.16 12.82 12.08 8.337

0.741935483870968 14.88 14.7 14.12 12.8 11.97 8.318

0.774193548387097 14.8 14.62 14.02 12.63 11.94 8.313

0.806451612903226 14.54 14.36 13.75 12.61 11.92 8.142

0.838709677419355 14.34 14.17 13.49 12.61 11.84 8.028

0.870967741935484 13.89 13.72 13.07 12.22 11.75 7.919

0.903225806451613 13.64 13.47 12.79 11.95 11.49 7.872

0.935483870967742 13.2 13.03 12.4 11.19 10.45 6.757

0.967741935483871 10.13 9.984 9.426 9.014 8.759 4.648

0.1 18.755 18.549 17.931 16.583 15.663 10.548

Average of yearly averages: 9.0608

Inputs generated by pe5.pl - Novemeber 2006

Data used for this run:

Output File: MSsoy

Metfile: w03940.dvf

PRZM scenario: MSsoybeanSTD.txt

EXAMS environment file: pond298.exv

Chemical Name: AZOXYSTROBIN

Description Variable Name Value Units Comments

Molecular weight mwt 403 g/mol

Henry's Law Const.henry atm-m^3/mol

Vapor Pressure vapr 8.2E-13 torr

Solubilitysol 6.7 mg/L

Kd Kd 12.68 mg/L

Koc Koc mg/L

Photolysis half-life kdp 23.23 days Half-life

Aerobic Aquatic Metabolism kbacw 322.2 days Halfife

Anaerobic Aquatic Metabolism kbacs 62.3 days Halfife

Aerobic Soil Metabolism asm 161.2 days Halfife

Hydrolysis: pH 5 0 days Half-life

Hydrolysis: pH 7 0 days Half-life

Hydrolysis: pH 9 0 days Half-life

Method: CAM 2 integer See PRZM manual

Incorporation Depth: DEPI 4 cm

Application Rate: TAPP 0.217 kg/ha

Application Efficiency: APPEFF 0.95 fraction

Spray Drift DRFT 0.5 fraction of application rate applied to pond

Application Date Date 01-05 dd/mm or dd/mmm or dd-mm or dd-mmm

Interval 1 interval 14 days Set to 0 or delete line for single app.

app. rate 1 apprate 0.187 kg/ha

Record 17: FILTRA

IPSCND 1

UPTKF

Record 18: PLVKRT

PLDKRT

FEXTRC0.5

Flag for Index Res. Run IR EPA Pond

Flag for runoff calc. RUNOFFnone none, monthly or total(average of entire run)
Page 12 of 13

Appendix B. AgDRIFT Model Inputs and Outputs

AgDRIFT® Input Data Summary

--General--

Tier: II

Title: Untitled

Notes: 

Calculations Done: Yes

Run ID: AgDRIFT® soy50.agd 2.01 01-13-2011 10:36:58

Default values appear when they differ from the Current values.

--Aircraft-- ----------Current----------- ----------Default----

-------

Name Air Tractor AT-401

Type Slow Fixed-wing

Boom Length (%) 76.3

Boom Height (ft) 10

Flight Lines 20

--Drop Size Distribution-- ----------Current----------- ----------Default----

-------

Name Aerosol to Very Fine ASAE Fine to 

Medium

Type Basic

Drop Categories # Diam (um) Frac Diam (um) 

Frac

 1 10.77 0.0280 10.77 

0.0010

 2 16.73 0.0350 16.73 

0.0003

 3 19.39 0.0300 19.39 

0.0007

 4 22.49 0.0200 22.49 

0.0003

 5 26.05 0.0210 26.05 

0.0007

 6 30.21 0.0460 30.21 

0.0010

 7 35.01 0.0780 35.01 

0.0010

 8 40.57 0.1060 40.57 

0.0020

 9 47.03 0.1250 47.03 

0.0033

 10 54.50 0.1240 54.50 

0.0053

 11 63.16 0.0860 63.16 

0.0067

 12 73.23 0.0610 73.23 

0.0090

 13 84.85 0.0700 84.85 

0.0133

 14 98.12 0.0710 98.12 

0.0223
Page 13 of 13

 15 113.71 0.0540 113.71 

0.0330

 16 131.73 0.0270 131.73 

0.0393

 17 152.79 0.0060 152.79 

0.0480

 18 177.84 0.0020 177.84 

0.0647

 19 205.84 0.0100 205.84 

0.0830

--Swath-- ----------Current----------- ----------Default----

-------

Swath Width 60 ft

Swath Displacement 0.6506 x Swath Width 0.3702 x 

Swath Width

--Spray Material-- ----------Current----------- ----------Default----

-------

Nonvolatile Rate (lb/ac) 0.328 

0.501

Active Rate (lb/ac) 0.0443 

0.2505

Spray Volume 

 Rate (gal/ac) 0.5 

2

Carrier Type Oil 

Water

--Meteorology-- ----------Current----------- ----------Default----

-------

Wind Speed (mph) 10

Temperature (deg F) 86

Relative Humidity (%) 50

--Transport-- ----------Current----------- ----------Default----

-------

Flux Plane (ft) 0