                     U. S. ENVIRONMENTAL PROTECTION AGENCY
                            Washington, D.C. 20460	

              OFFICE OF CHEMICAL SAFETY AND POLLUTION PREVENTION
                                                                       								
                                                                PC Code: 090100
                                                             DP Barcode: 414839

September 23, 2013                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   MEMORANDUM	

SUBJECT:	Tier II Drinking Water Assessment to Establish Tolerances of Chlorantraniliprole on Various Crops with Multiple Seasons

TO:	Jennifer Urbanski, Risk Manager Reviewer
	Venus Eagle, Risk Manager
	Laura Nollen, Risk Manager Reviewer
	Barbara Madden, Risk Manager
         Kristin Rury, Health Effects Division	
	
FROM:	Christopher M. Koper, Chemist
	Sujatha Sankula, Ph.D., Branch Chief 
	Environmental Risk Branch I
	Environmental Fate and Effects Division (7507P)

EXECUTIVE SUMMARY

A Tier II screening-level drinking water assessment was conducted to establish tolerances of chlorantraniliprole for various crops with multiple seasons including Brassica (Cole) leafy vegetables, curcurbit vegetables, fruiting vegetables, leafy vegetables, legumes, root and tuber vegetables and strawberries.  This is a follow up assessment to the drinking water assessment (D411577+) recently issued on 24 July 2013.  

The assessment was based on information contained in DuPont(TM) Coragen(R) (EPA Reg. No. 352-729) insect control label and the estimated drinking water concentrations (EDWCs) were based on the maximum proposed application rates and management practices specified in the product label.  The EDWCs for the human health risk assessment and modeling input parameter tables are presented in Table 1 and Table 2.  A representative surface water modeling output file is attached in Appendix I.  

For surface water, the EDWCs for the scenarios modeled in this assessment did not exceed the previous EDWCs for use on cranberries reported in a previous drinking water assessment (D381819+) dated 01 December 2010.  The previously reported acute concentration of 55.30 ug/L, annual mean (chronic) concentration of 39.87ug/L are greater than the reported EDWCs from the proposed uses for all scenarios reported in Table 1.  Therefore, the current EDWCs for surface water do not supersede the drinking water concentrations for cranberry previously estimated for this chemical. 

For groundwater, SCI-GROW and PRZM-GW simulations were not executed since the maximum rates were identical to the drinking water assessment (D411577+) recently issued on 24 July 2013.  To recall, the SCI-GROW model estimated a chlorantraniliprole concentration of 3.42 ug/L (Table 1).    In addition, PRZM-GW concentration estimates were significantly greater than SCI-GROW estimates.  To summarize, these conclusions are identical to the drinking water assessment (D411577+) recently issued on 24 July 2013.  If additional refinements are necessary, please contact Chris Koper at 703.347.8065 or koper.christopher@epa.gov.

Table 1.  Chlorantraniliprole Estimated Drinking Water Concentrations (EDWCs)[1] for Surface Water and Ground Water based on selected Crop Scenarios
                              Proposed Label Use
                                  PRZM/EXAMS
                                  Scenario[1]
                               (first app date)
                                   Method[2]
                               Application Rate
                        (interval between applications)
                          1-in-10 year acute (ug/L)
                         1-in-10 year chronic (ug/L)
                           30- year average (ug/L)
                                 Surface Water
Dupont(TM) Coragen[(R)] insect control with RYNAXPYR[(R)]  [EPA Reg. No. 352-729]
Brassica (Cole)
Leafy Vegetables

CA Cole Crop
(February 08 - foliar)
                                       A
                          3 app @ 0.067 lb a.i./acre
                               (3-day interval)
                             [0.2 lb a.i./A/crop]
                             [0.8 lb a.i./A/year]
                                     30.47
                                     14.31
                                     10.76
Cucurbit Vegetables
FL Cucumber
(November 01  -  foliar)
                                       A
                          2 app @ 0.100 lb a.i./acre
                               (5-day interval)
                             [0.2 lb a.i./A/crop]
                             [0.6 lb a.i./A/year]
                                     23.19
                                     5.24
                                     3.15

MI Melon
(June 11  -  foliar)
                                       

                                     17.53
                                     8.22
                                     6.44

MO Melon
(June 17  -  foliar)
                                       

                                     24.90
                                     5.65
                                     3.33

NJ Melon
(June 16  -  foliar)
                                       

                                     17.78
                                     8.23
                                     5.05

Fruiting Vegetables


CA Tomato
(June 17   -  foliar)
                                       A
                          2 app @ 0.100 lb a.i./acre
                               (5-day interval)
                             [0.2 lb a.i./A/crop]
                             [0.6 lb a.i./A/year]
                                     21.05
                                     14.30
                                     10.89

FL Tomato
(April 7   -  foliar)
                                       

                                     26.98
                                     4.99
                                     3.60

PA Tomato
(June 16  -  foliar)
                                       

                                     22.02
                                     9.32
                                     5.84
Leafy Vegetables
CA Lettuce
(April 21   -  foliar)
                                       A
                          2 app @ 0.100 lb a.i./acre
                               (3-day interval)
                             [0.2 lb a.i./A/crop]
                             [0.8 lb a.i./A/year]
                                     30.05
                                     15.94
                                     12.04
Legumes
MI Beans
(July 13   -  foliar)
                                       A
                          2 app @ 0.100 lb a.i./acre
                               (3-day interval)
                             [0.2 lb a.i./A/crop]
                             [0.6 lb a.i./A/year]
                                     36.32
                                     15.07
                                     9.37
Root and Tuber Vegetables

Leaves of Root and Tuber Vegetables
FL Carrot
(January 01  -  foliar)
                                       A
                          3 app @ 0.067 lb a.i./acre
                               (3-day interval)
                             [0.2 lb a.i./A/crop]
                             [0.8 lb a.i./A/year]
                                     32.17
                                     6.25
                                     4.27

ID Potato
(August 01   -  foliar)
                                       

                                     16.03
                                     11.29
                                     9.92

ME Potato
(September 17   -  foliar)
                                       

                                     21.40
                                     11.96
                                     10.02

MN Sugarbeet
(September 17   -  foliar)
                                       

                                     25.54
                                     20.05
                                     13.85

NC Sweet Potato
(September 01   -  foliar)
                                       

                                     34.82
                                     11.68
                                     8.74
Strawberry 

FL Strawberry
(October 27   -  foliar)
                                       A
                          3 app @ 0.067 lb a.i./acre
                               (7-day interval)
                             [0.2 lb a.i./A/crop]
                             [0.4 lb a.i./A/year]
                                     12.17
                                     2.50
                                     1.66
                                 Ground Water
SCI-GROW
Brassica (Cole) Leafy Vegs
Root and Tuber Vegs

                                      --
                          12 app @ 0.067 lb a.i./acre
                                     3.42
                                     3.42
                                     3.42
PRZM-GW

--------------------------------------------------------------------------------
Wisconsin Corn Scenario
Brassica (Cole) Leafy Vegs
Root and Tuber Vegs





                                      ---

                        11 app x 0.073 lb a.i./acre [2]
                                       
                                      221
                                    207[*]
                                      --
1 For surface water (PRZM/EXAM), EDWC values adjusted with a Percent Cropped Area (PCA) factor of 0.91.  For ground water (SCI-GROW and PRZM-GW), no PCA adjustment was utilized.  
[2] The maximum application rate of 0.80 lb a.i./A/year was divided by 11 instead of 12 because the shell of PRZM-GW maximum application number is 11.
* PRZM-GW value represents the post-breakthrough average.


Table 2.  PRZM/EXAMS Input Parameters for Chlorantraniliprole
Input Parameter:
Value:
Comment:
Source:
Scenario(s):
Brassica (Cole) Leafy Vegetables:
CA Cole Crop

Curcurbit Vegetables:
FL Cucumber
MI, MO, NJ Melon

Fruiting Vegetables:
CA, FL, PA Tomato

Leafy Vegetables:
CA Lettuce

Legumes:
MI Beans

Leaves of /and Root and Tuber Vegetables:
FL Carrot
ID, ME Potato
MN Sugarbeet
NC Sweet Potato

Strawberry:
FL Strawberry
representative scenarios for each use
N/A 
Maximum Single 
Application Rate
lbs a.i./acre (kg a.i./ha)
Brassica (Cole) Leafy Vegs:  0.067 (0.075)  

Curcurbit Vegetables:  0.100 (0.112)    

Fruiting Vegetables:  0.100 (0.112)    

Leafy Vegetables:  0.100 (0.112)    

Legumes:  0.100 (0.112)    

Leaves of /and Root and Tuber Vegs:  0.067 (0.075)  

Strawberry:  0.067 (0.075)   
proposed maximum single application rate
proposed  label
Applications per Year
Brassica (Cole) Leafy Vegs:  12
(3 apps/season x 4 seasons)

Curcurbit Vegetables:  6
(2 apps/season x 3 seasons)

Fruiting Vegetables:  6
(2 apps/season x 3 seasons)

Leafy Vegetables:  8
(2 apps/season x 4 seasons)

Legumes:  6
(2 apps/season x 3 seasons)

Leaves of /and Root and Tuber Vegs:  12
(3 apps/season x 4 seasons)

Strawberry:  6
(3 apps/season x 3 seasons) 
label directions.  Application number for maximum single application rate.
proposed label
Application Interval (days)
Brassica (Cole) Leafy Vegs:  3
Curcurbit Vegetables:  5
Fruiting Vegetables:  5
Leafy Vegetables:  3
Legumes:  3
Leaves of /and Root & Tuber Vegs:  3
Strawberry:  7 
proposed application intervals
proposed label
Date of Initial Application
(scenario: day-month)
Brassica (Cole) Leafy Vegetables:
CA Cole Crop:  08-02
Curcurbit Vegetables:
FL Cucumber:  01-11
MI Melon:  11-06
MO Melon:  17-06
 NJ Melon:  16-06
Fruiting Vegetables:
CA Tomato:  17-06
FL Tomato:  07-04
PA Tomato:  16-06
Leafy Vegetables:
CA Lettuce:  21-04
Legumes:
MI Beans:  13-07
Leaves of /and Root and Tuber Vegetables:
FL Carrot:  01-01
ID Potato:  01-08
ME Potato:  17-09
MN Sugarbeet:  17-09
NC Sweet Potato:  01-09
Strawberry:
FL Strawberry:  27-10
For most crops, to give a representative window of the growing season, the date of initial application was selected as two weeks (14 days) before crop maturation from crop scenario data.  For FL Cucumber, November 01 was selected as the initial date of application in order to fit all applications in a given calendar year which is needed to run the model.

Crop Scenarios
Application Method
Foliar:  aerial 
label directions
proposed label
CAM Input
2  (foliar: aerial, ground)

(2) linear foliar based on crop canopy
US EPA, 2005
IPSCND Input
Brassica (Cole) Leafy Vegs:  2
Curcurbit Vegetables:  3
Fruiting Vegetables:  3
Leafy Vegetables:  2
Legumes:  3
Leaves of /and Root & Tuber Vegs:  3
Strawberry:  3 
...remaining pesticide on foliage is (2) remaining pesticide on foliage is completely removed after harvest (3) is retained as surface residue and continues to decay.  This input only applies to foliar applications (CAM 2).
US EPA, 2005
Spray Drift Fraction
0.16  (aerial)

--
Input parameter guidance (USEPA, 2009) 
Application Efficiency
0.95  (aerial)

--
Input parameter guidance 
(USEPA, 2009)
Molecular Mass (g/mol)
483.15
--
--
Vapor Pressure at 25°C (torr)
1.57 x 10[-13]
--
DuPont 16517
Henry's Law Constant
(atm-m[3]/mol)
9.76 x 10[-14]
estimated
calculated from solubility, vapor pressure and molecular weight
Solubility in Water (mg/L)
1.023
--
MRID 46889026
Organic Carbon Partition Coefficient (KOC) (L/kgOC)
330
[1] represents the average KOC from 5 values
MRID 46889123
Aerobic Soil Metabolism Half-life (days)
627 
2 , 3, 4 Calculated 90[th] percentile of mean. (mean= 509 days, SD= 253 days, t= 1.40, n= 9)
*Several reported half-lives in MRID 46889124
 were not used because of poor fit with first-order degradation model
MRID 46889014
MRID 46889015
MRID 46889124

Aerobic Aquatic Metabolism Half-life (days)
341
2 Calculated 90[th] percentile of mean.  Mean= 178 days, SD= 74.95 days, t= 3.078, n=2
MRID 46889016
Anaerobic Aquatic Metabolism Half-life (days)
624
208 days single half-life
(3 x 208 days  per EFED guidance)
DuPont 14568
Hydrolysis Half-lives (days)
0  (stable)
pH 7
MRID 46889017
Aqueous Photolysis
Half-life (days)
32.8 [5]
Natural sunlight half-life
MRID 46889122
 N/A = Not Applicable
[1] = Koc values include 152, 438, 535, 268, 255.
2 = tinput=Mean + (t90,n-1*SD) / √N
[3] =  EFED recalculated first-order half-lives for both benzo- and pyrazole-labeled chlorantraniliprole. The calculated half-lives are based on aerobic soil 
       metabolism data in non-sterile soil at 25[0]C. Half-lives used in the assessment include 578, 537, 375, 41, 247, 228, 889, 924, 396 days.  
4 =  The 90[th] percentile of the mean half-life for chlorantraniliprole was 600 days for half-lives values presented in the OECD Chlorantraniliprole 
       Volume  3(1): Annex B, Environmental Fate and Behavior. (mean = 491 ( 886, 539, 380, 233, 323, 629, 423, 518 days); SD=203; t90, n-1 =1.417; N=8
5 =  The natural sunlight half-life value of 32.8 days was modeled because this better half-life characterizes the behavior of  
       chlorantraniliprole in the environment.  MRID 46889018 calculates a half-life of 0.31 days from a xenon arc lamp experiment using
       continuous irradiation.







APPENDIX I:  Representative Outputs












PRZM/EXAMS:  Michigan Beans  -  Aerial Application to represent Legumes



