UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D. C.  20460

		

OFFICE OF

PREVENTION, PESTICIDES

AND TOXIC SUBSTANCES



DP Barcodes: D323892

October 24, 2006

Aquatic Exposure Assessment

SUBJECT:	Tier I Drinking Water Assessment of Bifenazate (PC Code:
000586; CAS # 			149877-41-8) and the Degradate of Toxic Concern (D1989)
Resulting from the Use 		on Pea, Tuberous and Corm Vegetable Groups

TO:		Sidney Jackson

		Minor Use and Emergency Response Branch

		Registration Division (7505P)

		Dana Vogel, Acting Branch Chief

		Risk Assessment Branch 1

		Health Effects Division (7509P)

FROM:	Lucy Shanaman, Chemist

Environmental Risk Branch III

Environmental Fate and Effects Division (7507P)

THRU:	Daniel Rieder, Branch Chief

Environmental Risk Branch III

Environmental Fate and Effects Division (7507P)

	This document contains the Tier I Drinking Water (EDWCs) of bifenazate
(hyrrazine carboxylic acid,
2-(4-methoxy-[1,1'-biphenyl]-3-yl)-methylethyl ester, CAS #
149877-41-8),  and the bifenazate degradate,  D1989 (4-methoxybiphenyl,
CAS # 613-37-6), in surface and ground water for the new uses tuberous
and corm vegetables, and for garden peas and edible pea pods.  

	The maximum application rate listed in the proposed label(s) for
tuberous and corm vegetables are one application at 0.75 pounds per
acre.  The maximum application rate listed in the proposed label(s) for
succulent peas is one application at 0.50 pounds per acre.  These
application rates do not exceed the rates used in previous Tier 1
drinking water assessment for use of bifenazate on hops, potatoes and
strawberries, (D286171, October 09, 2003, appended below).  Because Tier
1 assessments are generic, and do not represent specific crops grown in
select geographic locations, these new uses are not expected to produce
EDWCs that significantly exceed those in the previous assessments. 
While EFED recognizes that the use of more current versions of the Tier
1 models would produce slightly differing concentration values, the
resulting changes are not expected to be substantially different. 
Please inform EFED if further refinement of these estimated
concentrations is desired.  

	UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

 

	WASHINGTON, D.C.  20460

     	            	 							 OFFICE OF  

       PREVENTION, PESTICIDES

        AND TOXIC SUBSTANCES 

DP Barcode: D286171

Out Date: October 09, 2003

Water Resources Assessment- Amendment I 

SUBJECT:	Tier I Water Resources Assessment of Bifenazate and its
Degradate, D1989

Bifenazate PC Code: 000586; CAS # 149877-41-8

Company: Crompton Uniroyal Chemical 

TO:		Andrew Ertman, PM Team Reviewer

Insecticide-Rodenticide Branch

Registration Division (7505C)

FROM:	Thuy L. Nguyen, Chemist

Environmental Risk Branch III

Environmental Fate and Effects Division (7507C)

THRU:	Ben Smith, Branch Chief

Environmental Risk Branch III

Environmental Fate and Effects Division (7507C)

CC:		Mary Clock-Rust

Registration Action Branch 1

Health Effects Division (7509C)

This document represents an amendment to the Aquatic Exposure Assessment
of Bifenazate issued on November 21, 2001 and supercedes any aquatic
exposure assessment previously reported under this chemical.

This assessment includes the Tier I Drinking Water Estimated
Concentrations (DWEC) and Estimated Environmental Concentrations (EECs)
of bifenazate degradate, D1989, based on the use of bifenazate on
strawberries (DP286171; two ground applications per season, 0.5 lb
ai/A/application at 21-day apart), and on potatoes (DP293438/DP293439;
one aerial application per season, 0.75 lb ai/A).  The previous document
(“Tier I Aquatic Exposure Assessment of Bifenazate”
TLNguyen/SOonnithan, dated November 21, 2001) only addressed hops and
cotton at one single ground application rate of 0.75 lb ai/A per season.

The screening results reported in this assessment are based the
assumption that bifenazate totally metabolizes and degrades to D1989. 
However, based on the aerobic soil metabolism study of the parent
bifenazate, D1989 was detected at a maximum of only 27% of total
applied.  Please refer to the November 21, 2001 report for a detailed
water resources assessment of D1989.

Table I lists the DWECs estimated by FIRST (surface water) and by
SCI-GROW (ground water) for use in assessing human health exposure, and
the EECs by GENEEC2 for use in terrestrial exposure.

Table I - DWECs and EECs for D1989

	

Hops 

one ground application

0.75 lb ai/A	

Potatoes

one aerial application

0.75 lb ai/A	

Strawberries

two ground applications 0.5 lb ai/A/appl



Surface Water (FIRST) DWEC:  Peak (acute) 	

17.8 ppb	

19.1 ppb	

22.8 ppb



                                                Annual Average (chronic)


4.96 ppb	

5.71 ppb	

6.38 ppb



Surface Water (GENEEC2) EECs:  Peak            	

8.53 ppb	

9.95 ppb	

11.0 ppb



                                              4 day average	

8.43 ppb	

9.85 ppb	

10.9 ppb



                                               21 day average	

7.87 ppb	

9.20 ppb	

10.1 ppb



                                               60 day average	

6.77 ppb	

7.93 ppb	

8.73 ppb



                                              90 day average	

6.08 ppb	

7.14 ppb	

7.84 ppb



Ground Water ( SCI-GROW) DWEC: acute and chronic 	

<1 ppt	

<1 ppt	

<1 ppt



For human health exposure, based on the previously registered uses and
the currently proposed uses, EFED recommends the use of the DWECs
generated by FIRST on strawberries, since they are the most conservative
values.

   Appendix I- 			

 FIRST - RUN No.   1 FOR D1989         ON   POTATO        * INPUT VALUES
* 

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

    RATE (#/AC)   No.APPS &   SOIL   SOLUBIL   APPL TYPE  %CROPPED   
INCORP

     ONE(MULT)    INTERVAL    Koc    (PPM )       (%DRIFT)         AREA 
         (IN)

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

   .750(   .750)               1   1        3011.0    3.8         
AERIAL(16.0)         87.0             .0

   FIELD AND RESERVOIR HALF-LIFE VALUES (DAYS) 

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

   METABOLIC  DAYS UNTIL  HYDROLYSIS   PHOTOLYSIS   METABOLIC  COMBINED

    (FIELD)         RAIN/RUNOFF  (RESERVOIR)    (RES.-EFF)        
(RESER.)         (RESER.) 

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

    180.00                      2                        N/A            
     .00-     .00           360.00              360.00

   UNTREATED WATER CONC (MICROGRAMS/LITER (PPB))    Ver 1.0 AUG 1, 2001

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

        PEAK DAY  (ACUTE)      ANNUAL AVERAGE (CHRONIC)      

          CONCENTRATION             CONCENTRATION            

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

                    19.122                                        5.707

 FIRST - RUN No.   2 FOR D1989         ON   HOPS          * INPUT VALUES
* 

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

    RATE (#/AC)   No.APPS &   SOIL   SOLUBIL   APPL TYPE  %CROPPED   
INCORP

     ONE(MULT)    INTERVAL    Koc    (PPM )       (%DRIFT)         AREA 
         (IN)

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

   .750(   .750)              1   1        3011.0        3.8       
GROUND( 6.4)     87.0              .0

   FIELD AND RESERVOIR HALF-LIFE VALUES (DAYS) 

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

   METABOLIC  DAYS UNTIL  HYDROLYSIS   PHOTOLYSIS   METABOLIC  COMBINED

    (FIELD)         RAIN/RUNOFF  (RESERVOIR)    (RES.-EFF)        
(RESER.)         (RESER.) 

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

    180.00                     2                         N/A            
   .00-     .00            360.00             360.00

   UNTREATED WATER CONC (MICROGRAMS/LITER (PPB))    Ver 1.0 AUG 1, 2001

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

        PEAK DAY  (ACUTE)      ANNUAL AVERAGE (CHRONIC)      

          CONCENTRATION             CONCENTRATION            

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

              17.753                                           4.964

FIRST - RUN No.   3 FOR D1989         ON   STRAWBERRY          * INPUT
VALUES * 

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

    RATE (#/AC)   No.APPS &   SOIL   SOLUBIL   APPL TYPE  %CROPPED   
INCORP

     ONE(MULT)    INTERVAL    Koc    (PPM )       (%DRIFT)         AREA 
         (IN)

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

   .500(   .500)            2    21         3011.0     3.8         
GROUND( 6.4)      87.0             .0

   FIELD AND RESERVOIR HALF-LIFE VALUES (DAYS) 

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

   METABOLIC  DAYS UNTIL  HYDROLYSIS   PHOTOLYSIS   METABOLIC  COMBINED

    (FIELD)         RAIN/RUNOFF  (RESERVOIR)    (RES.-EFF)        
(RESER.)         (RESER.) 

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

    180.00                     2                            N/A         
  0.00-  496.00         360.00             360.00

   UNTREATED WATER CONC (MICROGRAMS/LITER (PPB))    Ver 1.0 AUG 1, 2001

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

        PEAK DAY  (ACUTE)      ANNUAL AVERAGE (CHRONIC)      

          CONCENTRATION             CONCENTRATION            

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

             22.786                                           6.377

GENEEC2 - RUN No.   1 FOR D1989         ON    POTATO      * INPUT VALUES
* 

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

    RATE (#/AC)    No.APPS &     SOIL   SOLUBIL    APPL TYPE    NO-SPRAY
   INCORP

     ONE(MULT)    INTERVAL      Koc     (PPM )         (%DRIFT)         
  (FT)               (IN)

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

   .750(   .750)              1   1             3011.0    3.8          
AERL_B( 13.0)          .0                 .0

   FIELD AND STANDARD POND HALF-LIFE VALUES (DAYS) 

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

   METABOLIC  DAYS UNTIL  HYDROLYSIS   PHOTOLYSIS   METABOLIC  COMBINED

    (FIELD)       RAIN/RUNOFF         (POND)          (POND-EFF)        
(POND)           (POND) 

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

    180.00                     2                           N/A          
    .00-     .00            360.00              360.00

   GENERIC EECs (IN MICROGRAMS/LITER (PPB))     Version 2.0 Aug 1, 2001

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

       PEAK      MAX 4 DAY     MAX 21 DAY    MAX 60 DAY    MAX 90 DAY

       GEEC      AVG GEEC       AVG GEEC        AVG GEEC        AVG GEEC

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

        9.95               9.85                    9.20                 
  7.93                     7.14

GENEEC2 - RUN No.   2 FOR D1989         ON   STRAWBERRY    * INPUT
VALUES * 

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

    RATE (#/AC)    No.APPS &     SOIL    SOLUBIL    APPL TYPE   
NO-SPRAY    INCORP

     ONE(MULT)    INTERVAL      Koc      (PPM )         (%DRIFT)        
   (FT)             (IN)

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

   .500(   .961)         2      21         3011.0          3.8         
GRHIFI(  6.6)         .0                  .0

   FIELD AND STANDARD POND HALFLIFE VALUES (DAYS) 

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

   METABOLIC  DAYS UNTIL  HYDROLYSIS   PHOTOLYSIS   METABOLIC  COMBINED

    (FIELD)          RAIN/RUNOFF      (POND)         (POND-EFF)        
(POND)           (POND) 

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

       180.00                     2                       N/A           
    .00-     .00           360.00              360.00

   GENERIC EECs (IN MICROGRAMS/LITER (PPB))     Version 2.0 Aug 1, 2001

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

       PEAK      MAX 4 DAY     MAX 21 DAY    MAX 60 DAY    MAX 90 DAY

       GEEC      AVG GEEC       AVG GEEC        AVG GEEC        AVG GEEC

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

       10.99            10.87                    10.14                  
 8.73                    7.84

GENEEC2  RUN No.   3 FOR D1989         ON    HOPS      * INPUT VALUES * 

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

    RATE (#/AC)    No.APPS &     SOIL   SOLUBIL    APPL TYPE    NO-SPRAY
   INCORP

     ONE(MULT)    INTERVAL      Koc     (PPM )         (%DRIFT)         
  (FT)               (IN)

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

   .750(   .750)              1   1             3011.0    3.8          
GRHIFI(  6.6)           .0                 .0

   FIELD AND STANDARD POND HALF-LIFE VALUES (DAYS) 

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

   METABOLIC  DAYS UNTIL  HYDROLYSIS   PHOTOLYSIS   METABOLIC  COMBINED

    (FIELD)       RAIN/RUNOFF         (POND)          (POND-EFF)        
(POND)           (POND) 

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

    180.00                     2                           N/A          
    .00-     .00            360.00              360.00

   GENERIC EECs (IN MICROGRAMS/LITER (PPB))     Version 2.0 Aug 1, 2001

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

       PEAK      MAX 4 DAY     MAX 21 DAY    MAX 60 DAY    MAX 90 DAY

       GEEC      AVG GEEC       AVG GEEC        AVG GEEC        AVG GEEC

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

        8.53               8.43                    7.87                 
  6.77                     6.08

SCI-GROW - RUN No.   1 FOR D1989          ** INPUT VALUES **    

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

    APP RATE   APPS/     TOTAL/      SOIL       AEROBIC SOIL METAB  

    (LBS/AC)     YEAR     SEASON     KOC          HALF-LIFE (DAYS)    

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

       .750                1              .750        3905.0            
     60.00

 GROUND-WATER SCREENING CONCENTRATION (IN PPB) Ver 2.1  MAY 1, 2001

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

                     .0006 

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

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