++<ED 

### UNITED STATESENVIRONMENTAL PROTECTION AGENCY WASHINGTON, D. C. 20460

OFFICE OF PREVENTION, PESTICIDES AND TOXIC SUBSTANCES



### DPBarcodes: D3V 1784

Date: January 28,2010

SUBJECT: Tier I1 

### Drinking Water Assessment of Bifenazate (PC Code: 000586; GAS # 

### 149877-41-8)and the Degradate of Toxic Concern (D1989) for the ~rd~osed New Uses on Avocado, Tropical Fruit, Low Growing Berry, and Small ~iie ClimbingFruit

TO: Barbara Madden, RM 05 Risk Integration Minor Use, and Emergency Response Branch Registration Division (7505P)
Dana Vogel, Branch Chief Risk Assessment Branch I 

### Health Effects Division (7509P)

FROM: Mark Corbin, SeniorEn ' 

### Dana Spatz,Branch Chi Environmental Risk Branc Environmental Fate and Effects Division (7507P)

\ \ \ \



### Executive Summary

This document contains the Tier I1 

### Estimated Drinking Water Exposure Concentratiojs (EDWC) of bifenazate (isopropyl3-(4-methoxybiphenyl-3-yl) carbazate, CAS # 

### 149877-41-8)! and the bifenazate degradate, D 1989 (4-methoxybiphenyl, CAS # 

### 6 13-37-6),in surface and qround water for proposed new uses on Avocado, Tropical Fruit
,

### Low Growing Berry 

### ,and S/mallVine Climbing Fruit. The new use rates are similarto those recently assessed in October 2409 and are summarized in Table1



## . I

I



# l

# llllllllllulllllllllllllllllllIl1Il1 2084482

### ropical Fruit (LA sugarcane)'

ow Growing Berry 

### (FL strawberry)

Small Vine Climbing Fruit (NY grapes)

Bifenazatehas been previously assessed several times with the most recent drinking m!ater assessmentcompleted in August 3,2009 (D366486). Additional assessments were completed on November 21,2001, October 24,2006, and September 2008.

Based on available fate data, bifenazate (hydrazine carboxylic acid, 

### 2-(4-methoxy-[l ,

## 1'- biphenyl]-3-y1)-methylethyl ester) and the initial degradate, diazene (D3598) would bb expected to dissipate rapidlyunder most environmental conditions, with half-lives in the range of hours. The relatively stable degradate 4-methoxybiphenyl (D1989) is a major soil metabolite, and is

more persistent relative to the parent bifenazate. The aerobic soil metabolism half-life for the major bifenazate degradate,D1989, is estimated to be about two2or three months3. qile the parent compound, bifenazate, degrades too rapidly to accurately determine a specific

## &, value,

\ 

### laboratory data indicates that both bifenazatq, and the Dl989 degradationproduct, will be



## , slightly mobile. The degradation product Dl989 has the potential to reach surfacewater and ground water due to the persistence of Dl989 relative to the parent compound, bifenaaate.

Because of the rapid conversion of parent to Dl989 and the equivalent toxicity of Dl489 previous assessments have modeled the degradate and this assessment adopts that approach. The modeled application rate was adjustedto account forthe persistence of the degradationproduct relative to the parent compound, and the assumption that 100% of bifenazate convertsinto degradateD1989. Differences in molecular weight of bifenazate and the degradationproduct, D1989, were adjustedusing the following equation:

Modeled Application Rate =

### Labeled Application Rate ofBifenazate



### X (Molecular Weight of Dl989 / 

### Molecular Weight of Bifenazate)

The maximum reported EDWC from these previous assessments was 

### 37.3 ppb for aer;ial sprayto dry beans. The maximum EDWC from this assessment yielded a peak concentrationof 21.3 ppb

1 Tropical Fruit previously assessed in D366481 dated August 3, 2009

Calculated by EFEDIJ.Jordonfrom MRID 45 1440-02 3 Repo,ped in HED Metabolism Assessment Review Committee (MARC) Decision Document

### for low growing berries (strawberry scenario).


### Analysis Plan

This assessmentprovides EDWC for bifenazate and it's degradate (D1989). Dl889 is included in the DWA because it has been deemed to be a degradate of concern for human health effects. This assessmentrelies upon both existing and new environmental fate data (MRID 4767902) for the estimation of model inputs. EFED calculated the half-life for summed bifenazateresidues (parent and D1989) in aerobic soil metabolism studies. The upper 9oth percentile of the mean aerobic soil metabolism half-life for bifenazateresidues (bifenazate

# +D1989) is 42.7 days. This half-life was used in the exposure modeling. The 

### &, for Dl989 was used in exposuremodeling because it was lower than parent bifenazate.

PRZM (Version 3.1.22)lEXAMS (Version 2.98.06) models in the PE5 shell were used to estimateTier I1EDWC in surface water. The SCI-GROW (Version 2.3) model was used to estimate the Tier 1EDWC in ground water. Model inputs were derived from supplementaland acceptable registrant submitted data for bifenazate. Modeling scenariosused in this assessment

were selected to yield the highest EDWC from all available scenarios based on availability and runoff potential. 

### An exceptionto this is the tropical fruit use which was previously aslsessed in 2009 and whose EDWC are used here. Model inputs for PRZM/EXAMS and SCIGRQW are summarized in Table 2 and Table 3, respectively.

For drinking water exposure assessments EFED uses a percent cropped area (PCA) adjustment factor to account for the percentage of a watershed cropped to agriculture. For this aqessment, the default (87%) PCA has been applied because bifenazate can be applied to multiple crops.

(adjusted from 0.75 lblacre due to 2 applications @ 

### molecular wt 0.45 lblacre -


### fruit, & 

### low growingberry 9oth%of five Aerobic Soil 42.7 days individual TTR half Metabolism MRID 

### 45 144002 lives (60,21.1,23.3, 

### MRD 47607902 t l/, 

### 21.4, and 3 

### 1.2 days)

### Table 2. 

### PRZM/EXAMS Input Parametersfor Total Residues of Bifenazate TTR (Parentplus D1989) 

### for IRJPCA Drinking Water Assessment

Model Parameter Value Comments Source

Aerobic Aquatic 2x aerobic soil Degradation 85.4 days metabolism EFED Guidance
t ?h 

### Aqueous Photolysis Stable no data available for 

### mID 44464953
t l/, 

### degradate

, 

### Hydrolysis Stable no data available for 

### mID 

## d44649i2 

# I

degradate

Koc Due to bifenazate's rapid degradation in

aerobic soil study and immobility in 301 1mllg-OC soil column study, MRID 44464955 the lowest non-sand 

### MRID 44464956

(silt loam) Koc for the major degradate Dl989 was modeled. EPI Suite2000 3.8 ppm value for degradate (v3.12)

# bsKOW Water Solubility used

Fate and Transportof Pestjcjdes"dated February28,2002.



### 1application @ 

### 0.45 lblacre - 

### small vine Application Rate & 

### Max. climbing fruit Number of Application Product Labkl 2 applications @ 

### 0.45 lblacre - 

### avocado,tropical fruit, & 

### low

### Modeling Results

The EDWC for surfacewater are shown in Table 4. The tropical fruit use generated the highest 1 in 10year peak EDWC (16.7 pg/L). TheEDWC for ground water are shown in Table 

### 5.

Low Growing Berry



### Table

### 5: EFED EDWC (pg/L) 

### in Groundwater for Bifenazate (Combined Residues) Application Use Rate & # 

### of 

### DWEC (ppb) Applications 

# I Small Vine Climbing Fruit 0.45 lbs ailacre 

### 8.2E-3 1

### aPP Avocado 0.45 lbs ailacre Tropical Fruit 1.6 

### E-2 Low Growing.Berrv 2 

### aPPs I

### APPENDIX A PRZM/EXAMS & 

### SCIGROWMODEL OUTPUT

PRZM/EXAMS

stored as CA avocado air Eco.out Chemical: bifenazate PRZM environment: CAAvocadoRLF-V2.txt modifiedWedday, 26 March 2008 at 09:28:12 EXAMS environment: pond298.e~~ modifiedTueday, 26 August 2008 at 05:14:08 Metfile: w23188.dvf modifiedTueday, 26 August 2008 at 05:15:38 Water segment concentrations (ppb)

Year

Sorted results

Prob. Peak 1961 1.797 1962 2.1 9 1963 2.22 1964 2.422 1965 4.181 1966 2.927 1967 2.824 1968 2.778 1969 4.03 1970 2.668 1971 2.538 1972 2.38 1973 2.393 1974 2.433 1975 2.604 1976 2.61 1 1977 3.525 1978 2.783 1979 2.747 1980 2.723 1981 2.633 1982 2.696 1983 2.552 1984 2.34 1985 4.781 1986 2.928 1

987 2.717 1988 2.706 1989 2.473 1990 2.41 1

Peak 0.032258 4.781 21 Day 1.076 1.458 1584 1.686 3.053 2.1 88 2.083 2.037 2.767 1.926 1.797 1.638 1.649 1.742 1.861 1.911

2.54 2.099 2.038 1.983 1.892 1.954

1.81 1.597 3.214 2.191 1.976 1.963

1.73 1.668 60 Day 90 Day 0.7748

1.156 1.185 1.382 2.324 1.871 1.767 1.722 2.121 1.614 1.488 1.327 1.343 1.349 1.547 1.546 2.017 1.729 1.693 1.659 1.576 1.632 1.496 1.293 2.339 1.867 1.658 1.648 1.422 1.362

60 96 hr 21 Day Day 90 Day

4.328 3.214 2.339 Yearly 0.248 0.6857 0.7918 0.9203

1.137 1

535 1.438 1.302 1.481 1.219 1.059 0.9515 0.8855 0.9713

1.096

1.17 1.318 1.356 1.327 1.296 1.211 1.231 1.064 0.8596

1.143 1.581 1.311

1.24 0.9789 0.9282

Yearly 1

5810.1 3.9795 3.6332 2.7443 2.1 106 1.8326 1.4767 Average of yearly averages: 1.124527
Inputs generated by pe5.pl- Novemeber 2006

Data used for this run: Output File: CA avocado air Eco Metfile: PRZM scenario: EXAMS environment file: Chemical Name:
Description Molecularweight Henry's Law Const.
Vapor Pressure Solubility Kd Koc w23188.dvf CAAvocadoRLF-V2,txt pond298.exv bifenazate Variable Name Value Units Comments mwt 184 g/mol henry atm-mA3/mol3.80Evapr 04 torr sol 27.7 mg/L Kd mg/L Koc 3011 mg/LPhotolysis half-life Aerobic Aquatic Metabolism Anaerobic Aquatic Metabolism Aerobic Soil Metabolism
Hydrolysis:
Hydrolysis:
Hydrolysis: Method: Incorporation Depth: Application Rate:

- Application Efficiency: Spray Drift Application Date Interval 1 app. rate 1 Record 17:

Record 18:

Flag for Index Res. Run Flag for runoff calc. kdp kbacw kbacs
asm

pH 9 CAM DEPl TAPP APPEFF DRFT Date interval apprate FILTRA IPSCND UPTKF PLVKRT PLDKRT FEXTRC IR RUNOFF Halfdays life days Halfife days Halfife days HalfifeHalfdays lifeHalfdays lifeHalfdays life integer See PRZM manual
cm kglha fraction fraction of application rate applied td pond ddlmm or ddtmmm or dd-mm or dd-pmm days Set to 0 or delete line for single app. kglha

0.5 EPA Pond
none none, monthly or total(average of entire run)stored as FL strawberry air Eco.out Chemical: bifenazate PRZM environment: modified Tueday, 29 May 2007 at FLstrawberry-WirrigSTD.txt 12:53:40 EXAMS environment: pond298.exv modified Tueday, 26 August 2008 at 05:14:08 Metfile: w12842.dvf modified Tueday, 26 August 2008 at 05:14:20 Water segment concentrations (ppb)

Year

Sorted results

Prob. Peak 3.198 7.051 4.907 9.066 11.34 6.469 11.41 7.097 10.59 7.364 9.768 10.41 8.889 5.232 6.407 8.356 5.156 5.146 8.936 6.776 8.225 8.156 8.513 7.502 11.52 6.332 6.866 13.06 8.296 7.476 60 21 Day Day

2.287 2.085 5.253 4.543 3.822 3.542 7.149 6.494 8.683 6.579 5.743 4.918 8.488 6.18 5.898 5.355

8.89 7.176 6.226 5.343 7.424 6.556 8.496 6.484 7.213 6.85 4.464 4.21

5.28 4.867 6.049 5.074 4.305 4.062 4.479 3.913 7.632 6.98 5.846 5.309 6.358 5.694 6.732 6.325 7.148 6.482 6.198 5.525 8.274 6.993 5.518 5.199 5.935 5.334 9.642 8.057 7.326 6.451

6.32 5.388 90 Day

60 Peak 96 hr 21 Day Day 90 Day 0.032258 13.06 11.96 9.642 8.057 0.06451 6 11.52 10.71 8.89 7.176 0.096774 11.41 10.58 8.683 6.993 0.129032 11.34 10.34 8.496 6.98

0.16129 10.59 9.776 8.488 6.85 Yearly 0.7063

1.952 2.455 3.279 3.803 3.446 3.553 3.757 4.258 3.802 3.905 4.156 4.21 2 3.353 3.135 3.313

2.98 2.832 3.845 3.823 3.568 4.204 4.233 3.823 4.114 4.042 3.827 4.359 4.633 3.892

Yearly 4.633 4.359 4.258 4.233 4.2126.4158 Average of yearly averages:
Inputs generated by pe5.pl- Novemeber 2006

Data used for this run: Output File: FL strawberry air Eco Metfile: PRZM scenario: EXAMS environment file: Chemical Name:
Description Molecular weight Henry's Law Const.
Vapor Pressure Solubility Kd Koc
Photolysis half-life Aerobic Aquatic Metabolism Anaerobic Aquatic Metabolism wl2842.dvf FLstrawberry-WirrigSTD.txt pond298.e~~ bifenazate Variable Name Value Units Comments mwt 184 glmol henry atm-mA3/mol3.80Evapr 04 torr sol 27.7 mg/L Kd mg/L Koc 3011 mg/L Halfkdp 0 days life kbacw 360 days Halfife kbacs days HalfifeAerobic Soil Metabolism
Hydrolysis:
Hydrolysis:
Hydrolysis: Method: Incorporation Depth: Application Rate: Application Efficiency: Spray Drift

. Application Date Interval 1 app. rate 1 Record 17:

Record 18:

Flagfor Index Res. Run Flagfor runoff calc. asm
pH 5
pH 7
pH 9 CAM DEPl TAPP APPEFF DRFT Date interval apprate FILTRA IPSCND UPTKF PLVKRT PLDKRT FEXTRC I R RUNOFF days HalfifeHalfdays lifeHalfdays lifeHalfdays life integer See PRZM manual
cm kglha fraction fraction of application rate applied to pond ddlmm or ddlmmm or dd-mm or dd-mmm days Set to 0 or delete linefqr single app. kglha

0.5 EPA Pond
none none, monthly or total(average of entire run)stored as NY grapes air Eco.out Chemical: bifenazate PRZM environment: modifiedTueday, 29 May 2007 at NYGrapesSTD.txt 12:59:44 EXAMS environment: pond298.exv modifiedTueday, 26 August 2008 at 05:14:08 Metfile: w14860.dvf modifiedTueday, 26 August 2008 at 051512 Water segment concentrations (ppb)

Year Peak 1961 1.251 1962 3.471 1963 2.078 1 964 3.671 1965 5.105 1966 3.005 1967 5.882 1968 2.28 1 969 2.101 1 970 4.87 1971 3.336 1972 4.225 1 973 2.212 1974 2.249 1975 3.257 1976 2.232 1977 3.699 1978 4.302 1979 4.756 1980 5.89 1981 3.337 1982 3.271 1983 4.176 1 984 3.26 1 985 4.024 1986 3.093 1987 3.694 1988 3.198 1989 2.26 1990 2.995 21 Day 0.761 7 2.422

1.63 2.683 3.517 2.291 4.016

1.78 1.525 3.41 8 2.516 3.039 1.675 1.748 2.639 1.796 2.981 3.319 3.486 4.257

2.85 2.626 3.488 2.538 3.244 2.418 2.797 2.438 1.787 2.382 90 Day

Sorted results 60 Prob. Peak 96 hr 21 Day Day 90 Day 0.032258 5.89 5.429 4.257 3.724 0.06451 6 5.882 5.356 4.016 3.157 0.096774 5.105 4.665 3.517 2.933 0.129032 4.87 4.42 3.488 2.844

0.16129 4.756 4.41 3.486 2.763 Yearly 0.1739 0.81 48 1.127 1.324 1.629 1:436 1.549 1.322

1.04 1.358 1.636 1.641 1.277 1.125 1.525 1.293 1.443 1.912 2.142 2.459 2.207 1.904 1.872 1.751 1.658 1.558 1.697 1.641

1.34 1.206

Yearly 2.459 2.207 2.142 1.912 1.904Inputs generated by pe5.pl 

## - Novemeber 2006

Data used for this run: Output File: NY grapes air Eco Metfile: wl4860.dvf PRZM scenario: NYGrapesSTD.txt EXAMS environmentfile: pond298.exv

, Chemical Name: bifenazate Variable Description Name Value Molecular weight mwt 184 Henry's Law Const. henry 3.80EVapor Pressure vapr 04 Solubility sol 27.7 Kd Kd Koc Koc 301 1
Photolysis half-life kdp 0 Aerobic Aquatic Metabolism kbacw 360 Anaerobic Aquatic kbacs 2.6564 2.1 19 Average of yearly averages: 1.502023

Units Comments g/mol atm-mA3/mol

torr
mg/L

mg/L
m

### g/L Halfdays life days Halfife days HalfifeMetabolism Aerobic Soil Metabolism
Hydrolysis:
Hydrolysis:
Hydrolysis: Method: Incorporation Depth: Application Rate: Application Efficiency: Spray Drift Application Date Record 17:

Record 18:

Flag for Index Res. Run Flag for runoff calc. asm

PH 9 CAM DEPl TAPP APPEFF DRFT Date FILTRA IPSCND UPTKF PLVKRT PLDKRT FEXTRC IR RUNOFF days HalfifeHalfdays lifeHalfdays lifeHalfdays life integer See PRZM manual
cm kglha fraction fraction of application rate appliedto podd ddlmm or ddlmmm or dd-mm or dd-mmlm

0.5 EPA Pond
none none, monthly or total(average of entirerun)

### SCIGROW

VERSION 2.3 ENVIRONMENTAL FATE AND EFFECTS DIVISION OFFICE OFPESTICIDE PROGRAMS U.S. ENVIRONMENTAL PROTECTION AGENCY SCREENING MODEL FOR AQUATIC PESTICIDE EXPOSURE

SciGrowversion 2.3 chemicakbifenazate time is 81 312009 9: 7: 

### 9

........................................................................ 

### Application Number of Total Use Koc Soil Aerobic rate (lblacre) applications (lb/acrelyr) (ml/g) metabolism (days)

---------------------------------------------------------+-------------- 

### 0.450 2.0 0.900 3.01E+03 42.7

........................................................................ 

### groundwater screening cond (ppb) = 

### 1.64E-02

*****************************%*%**%**%**%*****%****************%***% 



### SCIGROW VERSION 2.3 ENVIRONMENTALFATE AND EFFECTS DIVISION OFFICE OF PESTICIDE PROGRAMS U.S. ENVIRONMENTAL PROTECTIONAGENCY SCREENING MODEL

\ 

### FOR AQUAT~ 

### PESTICIDE

## EXPOSUM

SciGrow version 2.3 chemical: bifenazate time is 81 312009 9: 9:57

---_--_--_----_-_-------------------------T----------------------------- 

### Application Number of Total Use Koc Soil Aerobic rate (lb/acre) applications (lblacrelyr) (mllg) metabolism (days)

........................................................................ 

### 0.450 

### 1 .O ' 

### 0.450 3.01E+03 42.7

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

### groundwater screening cond (ppb) = 

### 8.18E-03 ' ** ***************************b******************************%*%*%