UNITED STATES ENVIRONMENTAL PROTECTION

AGENCY

WASHINGTON D.C., 20460

OFFICE OF

CHEMICAL SAFETY

AND

POLLUTION

PREVENTION

PC Code: 119011

DP Barcode: 372897

DATE: 3/ 16 /2011

MEMORANDUM

SUBJECT: Flazasulfuron : Drinking Water Assessment for First Food Uses on citrus,

grapes and sugarcane and new outdoor non

- food uses on Christmas trees

and industrial vegetation management

FROM: Andrew Shelby, Physical Scientist

Environmental Fate and Effects Divison/ERB6 (7507P)

THRU: Mark Corbin, Branch Chief

Environmental Fate and Effects Divison/ERB6 (7507P)

TO: Cassi Walls,

Health Effects Division (7509P)

Linda Arrington , Risk Manager (RM 25 )

Registration Division (7505P)

The Environmental Fate and Effects Division (EFED) of the Office of Pesticide Programs (OPP)

has completed a Drinking Water Assessment for new use of flazasulfuron on citrus, grapes and

sugarcane and new outdoor non

- food uses on Christmas trees and industrial vegetation

management

. For all proposed new uses, the proposed maximum single application rate is 0.045

lb ai/A and the maximum seasonal application rate is 0.15 lb ai/A. Uses on Christmas trees and

non

- crop land has no maximum seasonal application limitation on the current pro posed label.

However, the registrant is aware of this and is in the process of submitting labels with consistent

annual application limitations of 0.15 lb ai/A per year across all uses. This assessment has been

conducted assuming these rates will be on t he final label. If they are not, the exposure levels

from these uses maybe different than those presented here. Currently registered for uses in

control of annual and perennial grasses, sedges, and broadleaf weeds on golf courses and other

non

- residentia l turf areas, this is the first food use petition associated with flazasulfuron. This

Tier II assessment , in accordance with the ROCKS memo (D386767), considers the major

degradates as parent in a total toxic residue (TTR) approach . Toxicity data and acc eptableenvironmental fate data is unavailable for flazasulfuron degradates. Submission of degradate

toxicity and environmental fate data would reduce uncertainty in the TTR approach and could

potentially reduce exposure. Given current uncertainty, the f ollowing degradates are included in

the TTR approach:

DTPU N

- [[(4,6

- dimethoxy

- 2

- pyrimidinyl)amino]carbonyl]

- 3

- (trifluoromethyl)

- 2

- pyridinesulfonamide

DTPP 4,6

- dimethoxy

- N

- [3

- trifluoromethyl)

- 2

- pyridinyl]

- 2

- pyrimidinamine

HTPP 6

- methoxy

- 2

- [[3

- trifluorome thyl)

- 2

- pyridinyl]amino]

- 4

- pyrimidinol

TPSA 3

- (trifluoromethyl)

- 2

- pyridinesulphonamide

ADMP 2

- amino

- 4,6

- dimethoxypyrimidine

2,3

- GTF 3

- trifluoromethyl

- 2

- pyridylguanidine

Based on modeling results ( SCIGROW ), the maximum estimated groundwater exposure

concentration for total toxic residues of flazasulfuron for new and expanded uses is 257 μg/L for

acute and chronic exposure

. The SCIGROW input and output files that produced these results

are attached as Appendix B.

Based on modeling results (PRZM/EXAMS ) , the maximum estimated surface water exposure

concentrations for total toxic residues of flazasulfuron for new and expanded uses are:

26.9 μg/L for the 1 in 10 year annual peak concentration

4.67 μg/L for the 1

- in

- 10 year annual average , and

2.76 μg/L for the 30 year annual average

These results were generated from the CA impervious scenario which represents new use for

industrial vegetation management. The CA impervious scenario produced the highest EDWCs

in comparison to other relevant scen arios. Other scenarios used for this Drinking Water

Assessment include FL citrus, FL nursery, FL sugarcane, LA sugarcane, MI sugarcane, NJ

nursery and TN nursery to represent agricultural uses on citrus, grapes, sugarcane and Christmas

trees and CA rangel and, CA residential, CA right of way, CA turf, FL turf, impervious BSS

,

range BSS and right of way BSS to represent industrial vegetation management uses . The

PRZM/EXAMS input and output files that produced these results are attached as Appendix A

.

This DWA differs from previous DWAs on flazasulfuron and reports higher EDWCs because of

the inclusion of nonextracted residues in metabolism studies. Nonextracted residues are likely

to be parent flazasulfuron or degradates included as total toxic residues. Data characterizing

adsorption/desorption behavior of degradates and metabolism studies with more rigorous

extraction techniques would reduce uncertainty associated with nonextracted residues.

Excluding nonextracted residues from half

- life calculations r educes EDWCs by less than 1% to

9% for scenarios resulting in highest crop and non

- crop EDWCs (CA impervious and LA

sugarcane). Assuming the K

oc of flazasulfuron represents the mobility of all degradates reduces

the acute and chronic groundwater EDWC by 9 4%. Adsorption/desorption and t oxicity data for

degradates would be of most use to reduce uncertainty with the TTR approach.

No monitoring data is available for flazasulfuron.Fate and Transport Characterization

The most significant degradation pathway for total toxic residues of flazasulfuron is photolysis

(half

- life = 34 days; MRID 46220950). Total toxic residues of f lazasulfuron are relatively more

persistent to metabolism with half

- lives ranging from 385 days to 3,466 days (MRID s 46220951,

46220953, 46220954). Total toxic residues of flazasulfuron are stable to hydrolysis (MRID

46220949). Parent flazasulfuron is mobile with a K D of 10 mL/g (MRID 46220955). It is not

appropriate to use K OC to characterize the mobility of flazas ulfuron because adsorption

coefficients do not sufficient ly correlate with soil organic carbon content. Degradates of

flazasulfuron are considered to be mobile (FAO Classification). The lowest degradate

adsorption coefficient estimated by EpiSuite is K OC = 10 mL/ g o.c. for ADMP.

Drinking Water Exposure Modeling

Input parameters for the derivation of Tier II surface water concentrations and the Tier 1

groundwater concentration are as follows:

Table 1

. PRZM/EXAMS input parameter values for flazasulfuron. Use on citrus, grapes,

sugarcane, Christmas trees and industrial vegetation management

**PARAMETER (units) VALUE(S)**  **SOURCE COMMENT** 

Application Rate (kg a.i./ha) 0.050 Proposed

label. Represents the maximum possible single

application rate per crop season (year) for

all uses. Equivalent to 0.045 lb a.i./A.

Number of Applications 3 + application of

0.019 kg a.i./ha Proposed

label. Represents the maximum possible

applications per crop season (year) for each

use. 4 th application achieves maximum

seasonal application rate.

Interval between Applications

(days) 14 Proposed

label. Represents the minimum possible interval

between applications per crop season (year)

for each use.

Molecular weight (g/mol) 407.4 Product

Chemistry -

Henry’s Law Constant (atm

m 3 /mol) 1.91 x 10

- 6 Product

Chemistry -

Vapor Pressure (torr) 7.5 x 10

- 3 Product

Chemistry -

Solubility in Water @ 20 O C,

(mg/L or ppm) 2100 Product

Chemistry –

Soil Partition Coefficient (mL/g) K OC = 10 EpiSuite Because acceptable degradate adsorption

data is not available, the lowest modeled

adsorption coefficient for flazasulfuron

degradates was used to represent the

mobility of total toxic residues (ADMP: 10

mL/g o.c.).**PARAMETER (units) VALUE(S)**  **SOURCE COMMENT** 

CAM (Chemical Application

Method) 1 Proposed

label. ground spray; pre

- plant or pre

- emergence,

unincorporated

Depth of Incorporation (inches) 0 Proposed

label. –

Application efficiency (decimal) Ground spray:

0.99 Input

Parameter

Guidance.

Spray drift fraction (decimal) Ground spray:

0. 01 Input

Parameter

Guidance.

Percent Cropped Area (decimal) Citrus, Grapes

Sugarcane,

Christmas trees:

0.87

Industrial

Vegetation

Management: No

PCA PCA

guidance National Default PCA used for agricultural

uses

Application date (day/month) Emergence dates

specified in

PRZM scenario Proposed

label and

PRZM

scenarios. Multiple a pplication dates surrounding the

emergence dates for highest agricultural and

non

- agricultural EDWCs were modeled also

Hydrolysis Half

- life (days) Stable MRID :

46220949 TTR included in estimation

Aqueous Photolysis Half

- life @

pH 7 (days) 34 MRID:

46220950 TTR included in half

- life estimation

. Study

conducted only at pH 7. Half

- life

estimation is likely to vary at a range of

pHs.

Aerobic Aquatic Metabolism Half

life (days) 432 MRID:

46220954 TTR and nonextracted residues included in

half

- life estimation. Represents the 90 th

percentile confidence bound on the mean of

two half

- life values (range: 408 days and

385 days ) . The study is supplemental due

to unaccounted residues and unextracted

residues >10% of applied by conclusion of

study.

Anaerobic Aquatic Metabolism

Half

- life (days) 2598 MRID:

46220953 TTR and nonextracted residues included in

half

- life estimation. 3X half

- life due to

single half

- life value per Input Parameter

Guidance**PARAMETER (units) VALUE(S)**  **SOURCE COMMENT** 

Aerobic Soil Metabolism Half

- life

(days) 10398 MRID :

46220951 TTR and nonextracted residues included in

half

- life estimation. 3X half

- life due to

single half

- life value per Input Parameter

Guidance . Study is supplemental due to

study termination at 268 days, inadequate

characterization of degradate formation

decline and inadequate records of sample

storage.

1 “Input Parameter Guidance” refer s to Guidance for Selecting Input Parameters in Modeling the Environmental

Fate and Transport of Pesticides; Version 2.1

, October 22, 2009

.

Table 2

. SCIGROW input parameter values for flazasulfuron. Use on citrus, grapes,

sugarcane, Christmas trees and industrial vegetation management

PARAMETER (units) VALUE(S) SOURCE COMMENT

Maximum Application Rate (lb

a.i./A) 0.045 Proposed label.

–

Number of Applications per Year 3.36 Proposed label. Represents the maximum possible

applications per crop season (year) for each

use. 4 th application achieves maximum

seasonal application rate.

Organic Carbon Partition

Coefficient (K

oc ; mL/g) 10 EpiSuite Because acceptable degradate adsorption

data is not available, the lowest modeled

adsorption coefficient for flazasulfuron

degradates was used to represent the

mobility of total toxic residues (ADMP: 10

mL/g o.c.).

Aerobic Soil Metabolism Half

- life

(days) 3466 MRID:

46220951 TTR and nonextracted residues included in

half

- life estimation. Study is supplemental

due to study termination at 268 days,

inadequate characterization of degradate

formation decline and inadequate records of

sample storage.

Percent Crop Area (PCA) post

- processing on surface water EDWCs are incorporated for food

uses but not for the non

- crop use, industrial vegetation management. The proposed label allows

applications for industrial vegetation management to “uncultivated non agricultural areas

including but not limited to airports, ditch banks, dry canals, highway, railroad and utility rights

of

- way, industrial sites, manufacturing sites, storage areas and warehouse areas.” This use

pattern is not captured in PCA estimates. No PCA adjustment is applied to the groundwater

exposure concentration. Modeled estimates are as follows.Table 3

. Ranges of Tier II Estimated Drinking Water Concentrations (EDWCs) for

surface water based on ground application of flazasulfuron to cit rus, grapes, sugarcane

and Christmas trees

. 0.87 PCA applied

Crop Scenario 1

- in

- 10 year Acute

concentration (ppb) 1

- in

- 10 year annual

average 30

- year annual

average

CA grape 0.37 0.17 0.09

FL citrus 2.97 0.74 0.27

FL nursery 2.68 0.66 0.21

FL sugarcane 5.09 0.90 0.48

LA sugarcane 6.40 1.05 0.62

NJ nursery 2.67 0.63 0.26

TN nursery 2.79 0.69 0.28

Table 4

. Ranges of Tier II Estimated Drinking Water Concentrations (EDWCs) for

surface water based on ground application of flazasulfuron industrial vegetation

management . N o PCA applied

.

Crop Scenario 1

- in

- 10 year Acute

concentration (ppb) 1

- in

- 10 year annual

average 30

- year annual

average

CA impervious 26.9 1 4.67 2.76

CA rangeland 2.37 0.573 0.417

CA residential 1.92 0.676 0.408

CA right of way 3.63 0.813 0.371

CA turf 2.26 0.866 0.479

FL turf 0.296 0.111 0.0623

impervious BSS 2 6.6 1 3.44 2 1.97 1

R ange BSS 2.62 0.696 0.306

right of way BSS 6.16 1.37 0.629

1

– January 7 application dateAppendix A: Output files for PRZM/EXAMS scenarios producing highest EDWCs

CA impervious January 1 application

stored as CAimperviousHYD.out

Chemical: flazasulfuron

PRZM environment: CAImperviousRLF.txt modified Tueday, 26 August 2008 at 05:16:48

EXAMS environment: ir298.exv modified Tueday, 26 August 2008 at 05:14:08

Metfile: w23234.dvf modified Tueday, 26 August 2008 at 05:15:38

Water segment concentrations (ppb)

Year Peak 96 hr 21 Day 60 Day 90 Day Yearly

1961 16.25 15.72 14.29 11.45 9.319 3.54

1962 12.86 12.56 10.91 6.712 5.053 1.693

1963 29.96 28.49 25.7 18.4 13.95 4.478

1964 5.27 5.103 4.846 4.225 3.898 1.926

1965 11.14 11.03 10.3 8.761 8.379 3.341

1966 26.88 26.22 22.1 16.75 14.79 7.425

1967 39.72 33.92 25.62 20.75 15.9 4.695

1968 21.17 19.77 18.29 15.03 12.34 5.223

196 9 18.71 17.4 12.82 7.513 5.8 1.96

1970 9.147 8.06 6.004 5.256 4.736 2.217

1971 3.438 3.279 2.712 2.345 2.227 1.255

1972 6.042 5.926 5.644 5.247 4.788 2.284

1973 19.85 18.46 12.97 8.597 6.462 2.192

1974 15.55 15 13.16 11.69 9.741 3.34

1975 25.5 24.61 20.48 12.52 9.188 3.132

1976 7.711 7.486 6.709 5.285 4.735 2.267

1977 11.06 10.89 9.865 8.347 7.371 3.861

1978 8.968 7.974 5.752 4.748 3.783 1.149

1979 15.85 14.39 9.944 7.335 6.212 2.631

1980 10.49 9.647 6.455 4.822 4.086 1.705

1981 5.15 4.997 4.629 3.561 2.901 1.211

1982 8.35 7.895 6.267 3.732 3.331 1.021

1983 12.27 11.27 9.303 5.726 4.019 1.094

1984 8.424 8.304 7.656 6.313 5.852 2.749

1985 10.68 10.17 8.47 6.431 5.658 2.554

1986 13.61 12.93 9.12 6.693 4.861 1.433

1987 12.16 11.6 9.113 7.435 6.725 3.317

1988 8. 417 8.133 7.761 7.456 7.019 3.211

1989 8.622 8.428 8.25 7.108 6.174 2.607

1990 8.496 8.185 7.428 6.893 6.412 3.168

Sorted results

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

0.032258064516129 39.72 33.92 25.7 20.75 15.9 7.4250.0645161290322581 29.96 28. 49 25.62 18.4 14.79 5.223

0.0967741935483871 26.88 26.22 22.1 16.75 13.95 4.695

0.129032258064516 25.5 24.61 20.48 15.03 12.34 4.478

0.161290322580645 21.17 19.77 18.29 12.52 9.741 3.861

0.193548387096774 19.85 18.46 14.29 11.69 9.319 3.54

0.22580645161290 3 18.71 17.4 13.16 11.45 9.188 3.341

0.258064516129032 16.25 15.72 12.97 8.761 8.379 3.34

0.290322580645161 15.85 15 12.82 8.597 7.371 3.317

0.32258064516129 15.55 14.39 10.91 8.347 7.019 3.211

0.354838709677419 13.61 12.93 10.3 7.513 6.725 3.168

0.387096774193548 12.86 12.56 9.944 7.456 6.462 3.132

0.419354838709677 12.27 11.6 9.865 7.435 6.412 2.749

0.451612903225806 12.16 11.27 9.303 7.335 6.212 2.631

0.483870967741936 11.14 11.03 9.12 7.108 6.174 2.607

0.516129032258065 11.06 10.89 9.113 6.893 5.852 2.554

0.548387096774194 10.68 10.17 8.47 6.712 5.8 2.284

0.580645161290323 10.49 9.647 8.25 6.693 5.658 2.267

0.612903225806452 9.147 8.428 7.761 6.431 5.053 2.217

0.645161290322581 8.968 8.304 7.656 6.313 4.861 2.192

0.67741935483871 8.622 8.185 7.4 28 5.726 4.788 1.96

0.709677419354839 8.496 8.133 6.709 5.285 4.736 1.926

0.741935483870968 8.424 8.06 6.455 5.256 4.735 1.705

0.774193548387097 8.417 7.974 6.267 5.247 4.086 1.693

0.806451612903226 8.35 7.895 6.004 4.822 4.019 1.433

0.838709677419355 7.71 1 7.486 5.752 4.748 3.898 1.255

0.870967741935484 6.042 5.926 5.644 4.225 3.783 1.211

0.903225806451613 5.27 5.103 4.846 3.732 3.331 1.149

0.935483870967742 5.15 4.997 4.629 3.561 2.901 1.094

0.967741935483871 3.438 3.279 2.712 2.345 2.227 1.021

0.1 26.74 2 26.059 21.938 16.578 13.789 4.6733

Average of yearly averages: 2.75596666666667

Inputs generated by pe5.pl

- Novemeber 2006

Data used for this run:

Output File: CAimperviousHYD

Metfile: w23234.dvf

PRZM scenario: CAImperviousRLF.txt

EXAMS environment file: ir298.exv

Chemical Name: flazasulfuron

Description Variable Name Value Units Comments

Molecular weight mwt 407.4 g/mol

Henry's Law Const. henry 1.91E

- 6 atm

- m^3/mol

Vapor Pressure vapr 7.5E

- 3 torr

Solubility sol 2100 mg/LKd Kd mg/L

Koc K oc 10 mg/L

Photolysis half

- life kdp 34 days Half

- life

Aerobic Aquatic Metabolism kbacw 432 days Halfife

Anaerobic Aquatic Metabolism kbacs 2598 days Halfife

Aerobic Soil Metabolism asm 10398 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 1 integer See PRZM manual

Incorporation Depth: DEPI 0 cm

Application Rate: TAPP 0.050 kg/ha

Application Efficiency: APPEFF 0.99 fraction

Spray Drift DRFT 0.01 fraction of application rate applie d to pond

Application Date Date 1

- 1 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 0.05 kg/ha

Interval 2 interval 14 days Set to 0 or delete line for single app.

app. rate 2 apprat e 0.05 kg/ha

Interval 3 interval 14 days Set to 0 or delete line for single app.

app. rate 3 apprate 0.018 kg/ha

Record 17: FILTRA

IPSCND 1

UPTKF

Record 18: PLVKRT

PLDKRT

FEXTRC 0.5

Flag for Index Res. Run IR Reservoir

Flag for runoff calc. RUNOFF none, monthly or total(average of entire run)

CA impervious January 2 application

stored as CAimperviousHYD12.out

Chemical: flazasulfuron

PRZM environment: CAImperviousRLF.txt modified Tueday, 26 August 2008 at 05:16:48

EXAMS environment: ir298.exv modi fied Tueday, 26 August 2008 at 05:14:08

Metfile: w23234.dvf modified Tueday, 26 August 2008 at 05:15:38

Water segment concentrations (ppb)

Year Peak 96 hr 21 Day 60 Day 90 Day Yearly

1961 13.08 12.58 11.93 9.581 7.795 2.963

1962 12.83 12.54 10.88 7.346 5. 619 1.961

1963 38.31 36.23 31.44 21.66 16.45 5.293

1964 5.81 5.626 5.334 4.66 4.299 2.128

1965 11.15 11.03 10.31 8.766 8.384 3.343

1966 18.07 17.4 15.07 11.77 10.46 5.4231967 39.71 33.92 26.8 22.66 17.45 5.174

1968 18.72 17.48 16.23 13.36 11.08 4.715

1969 18.7 17.39 11.23 6.563 5.077 1.72

1970 10.14 8.935 7.562 6.528 5.9 2.769

1971 4.54 4.33 3.585 3.493 3.373 1.749

1972 6.098 5.98 5.694 5.292 4.831 2.308

1973 24.61 22.86 15.07 9.318 6.937 2.305

1974 15.55 15 13.16 11.66 9.763 3.363

1975 27.1 26.15 21.34 12.94 9.47 3.222

1976 7.719 7.494 6.715 5.291 4.741 2.269

1977 15.17 14.72 13.51 12.03 11.48 5.546

1978 12.58 11.49 7.339 5.421 4.209 1.223

1979 15.56 14.13 9.763 6.254 5.19 2.319

1980 10.99 10.09 6.774 4.194 3.43 1.577

1981 6.937 6.732 6.185 4.263 3.471 1 .503

1982 8.524 8.06 6.4 4.224 3.616 1.093

1983 12.27 11.28 9.306 5.741 4.029 1.096

1984 6.567 6.486 5.991 4.885 4.297 2.053

1985 10.66 10.15 8.452 6.413 5.64 2.546

1986 11.56 10.62 7.733 5.915 4.322 1.288

1987 12.57 11.82 10.65 10.04 8.662 3.868

1988 11.8 8 11.26 9.4 8.712 8.452 3.889

1989 8.671 8.477 8.302 7.149 6.216 2.624

1990 10.38 10.06 9.387 8.729 7.935 3.695

Sorted results

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

0.032258064516129 39.71 36.23 31.44 22.66 17.45 5.546

0.0645161290322581 38.31 33.9 2 26.8 21.66 16.45 5.423

0.0967741935483871 27.1 26.15 21.34 13.36 11.48 5.293

0.129032258064516 24.61 22.86 16.23 12.94 11.08 5.174

0.161290322580645 18.72 17.48 15.07 12.03 10.46 4.715

0.193548387096774 18.7 17.4 15.07 11.77 9.763 3.889

0.225806451612903 18.07 17.39 13.51 11.66 9.47 3.868

0.258064516129032 15.56 15 13.16 10.04 8.662 3.695

0.290322580645161 15.55 14.72 11.93 9.581 8.452 3.363

0.32258064516129 15.17 14.13 11.23 9.318 8.384 3.343

0.354838709677419 13.08 12.58 10.88 8.766 7.935 3.222

0.387096 774193548 12.83 12.54 10.65 8.729 7.795 2.963

0.419354838709677 12.58 11.82 10.31 8.712 6.937 2.769

0.451612903225806 12.57 11.49 9.763 7.346 6.216 2.624

0.483870967741936 12.27 11.28 9.4 7.149 5.9 2.546

0.516129032258065 11.88 11.26 9.387 6.563 5.64 2.319

0.548387096774194 11.56 11.03 9.306 6.528 5.619 2.308

0.580645161290323 11.15 10.62 8.452 6.413 5.19 2.305

0.612903225806452 10.99 10.15 8.302 6.254 5.077 2.2690.645161290322581 10.66 10.09 7.733 5.915 4.831 2.128

0.67741935483871 10.38 10.06 7.562 5.741 4.741 2.053

0.709677419354839 10.14 8.935 7.339 5.421 4.322 1.961

0.741935483870968 8.671 8.477 6.774 5.292 4.299 1.749

0.774193548387097 8.524 8.06 6.715 5.291 4.297 1.72

0.806451612903226 7.719 7.494 6.4 4.885 4.209 1.577

0.838709677419355 6.937 6.732 6 .185 4.66 4.029 1.503

0.870967741935484 6.567 6.486 5.991 4.263 3.616 1.288

0.903225806451613 6.098 5.98 5.694 4.224 3.471 1.223

0.935483870967742 5.81 5.626 5.334 4.194 3.43 1.096

0.967741935483871 4.54 4.33 3.585 3.493 3.373 1.093

0.1 26.851 25.821 20.8 29 13.318 11.44 5.2811

Average of yearly averages: 2.83416666666667

Inputs generated by pe5.pl

- Novemeber 2006

Data used for this run:

Output File: CAimperviousHYD12

Metfile: w23234.dvf

PRZM scenario: CAImperviousRLF.txt

EXAMS environment file: ir298.exv

Chemical Name: flazasulfuron

Description Variable Name Value Units Comments

Molecular weight mwt 407.4 g/mol

Henry's Law Const. henry 1.91E

- 6 atm

- m^3/mol

Vapor Pressure vapr 7.5E

- 3 torr

Solubility sol 2100 mg/L

Kd Kd mg/L

Koc Koc 10 mg/L

Photoly sis half

- life kdp 34 days Half

- life

Aerobic Aquatic Metabolism kbacw 432 days Halfife

Anaerobic Aquatic Metabolism kbacs 2598 days Halfife

Aerobic Soil Metabolism asm 10398 days Halfife

Hydrolysis: pH 5 0 days Half

- life

Hydrolysis: pH 7 0 days Half

- life

Hy drolysis: pH 9 0 days Half

- life

Method: CAM 1 integer See PRZM manual

Incorporation Depth: DEPI 0 cm

Application Rate: TAPP 0.050 kg/ha

Application Efficiency: APPEFF 0.99 fraction

Spray Drift DRFT 0.01 fraction of application rate applied to pond

Applicat ion Date Date 2

- 1 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 0.05 kg/ha

Interval 2 interval 14 days Set to 0 or delete line for single app.app. rate 2 apprate 0.05 kg/ha

Interval 3 interval 14 days Set to 0 or delete line for single app.

app. rate 3 apprate 0.018 kg/ha

Record 17: FILTRA

IPSCND 1

UPTKF

Record 18: PLVKRT

PLDKRT

FEXTRC 0.5

Flag for Index Res. Run IR Reservoir

Flag for runoff calc. RUNOFF none, monthl y or total(average of entire run)

Appendix B: Output files for SCIGROW producing the groundwater EDWC

SciGrow version 2.3

chemical:flazasulfuron

time is 3/ 9/2011 13:12:18

------------------------------------------------------------------------ Ap plication Number of Total Use Koc Soil Aerobic

rate (lb/acre) applications (lb/acre/yr) (ml/g) metabolism (days)

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

0.045 3.4 0.151 1.00E+01 3466.0

------------------------------------------------------------------------ groundwater screening cond (ppb) = 2.57E+02

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