Document ID: EPA-HQ-OPP-2012-0912-0007
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2013-10-18T04:00Z

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON D.C., 20460

                                   OFFICE OF
                              CHEMICAL SAFETY AND
                             POLLUTION PREVENTION
							     
								 	       
                         				        
                                     		      PC Code: 121027			          DP Barcode: D407566
                                           	     

MEMORANDUM                                                                                         April 23, 2013

SUBJECT:	Drinking Water Assessment for the IR-4 New Use Petitions for the Use of Methoxyfenozide on Herb Subgroup 19A (except chives), Dates, Sorghum, Fruiting Vegetable Group 8-10, Pome Fruit Group 11-10, Berry Subgroups 13-07 A, F & G and Tropical Tree Fruits. 

TO:		Elizabeth Holman, Dietary and Risk Assessor
        		William Drew, Chemist
        		Risk Assessment Branch II
        		Health Effects Division, 7509P 

CC:		Laura Nollen, Risk Manager
                	Risk Integration Minor Use & Emergency Response Branch
                     	Mark Suarez, Product Manager Insecticide Branch
                	Registration Division, 7505P

FROM:	Karen Milians, Ph.D., Chemist
		Environmental Risk Branch IV
		Environmental Fate and Effects Division (7507P)

REVIEWED
BY:		Jim Carleton, Ph.D., Senior Scientist
		Environmental Risk Branch IV
		Environmental Fate and Effects Division (7507P)

APPROVED
BY:		Marietta Echeverria, Branch Chief
		Environmental Risk Branch IV
		Environmental Fate and Effects Division (7507P)

Executive Summary

	EFED has reviewed the IR-4 request for methoxyfenozide (Intrepid[(R)] 2F) registration on herb subgroup 19A (except chives), dates, sorghum, fruiting vegetable group 8-10, pome fruit group 11-10, berry subgroups 13-07 A, F & G, and tropical tree fruits (sugar apple, cherimoya, atemoya, custard apple, ilama, soursop, and biriba).  The maximum proposed single application rates for these crops range from 0.06 to 0.31 lbs a.i./acre, and the maximum seasonal rates range from 0.75 to 1.0 lbs a.i./acre. 
      The last drinking water assessment was completed in August 2011 for new uses on root vegetables subgroup 1B and citrus (USEPA, 2011).  The estimated drinking water concentrations (EDWCs) were based on the globe artichoke use represented by the CA lettuce scenario. 
      Table 1 lists the EDWCs recommended for use in HED's dietary risk assessment. These values are based on the globe artichoke use represented by the CA lettuce scenario with an application rate of 0.25 lbs. a.i./acre/application and a total of 1.0 lb a.i./acre/season.  The surface water EDWCs are slightly higher than EDWCs reported in previous assessments (68.8, 43.4 and 31.8 ppb for acute, chronic, and cancer, respectively).  The EDWCs are higher because of changes in the input parameters (to reflect current EFED policies) and a new PCA number used for all crops (USEPA, 2012a). Similarly, the groundwater EDWCs listed in Table 1 are higher than those reported in the most recent assessments (USEPA 2011) mainly because of the implementation of a new groundwater model; PRZM-GW, which accounts for pesticide fate in the crop root zone and multiple years of application. 
      EFED continues to have concerns that the combination of high persistence and moderate mobility of methoxyfenozide makes it plausible that this compound may pose a greater long-term risk than what is suggested by the screening-level drinking water assessments.  In particular, once introduced into the environment, this compound could migrate to sensitive environmental compartments and persist for extended periods of time.  One outstanding data requirement from the conditional registration of this compound is for the monitoring of surface water and sediment in a representative sample of high use areas in proximity to surface water.  The main purpose of this study is to address EPA's concern that multiple years of IntrepidTM use may result in accumulation of methoxyfenozide residues in water and/or sediment.  DAS (Dow Agricultural Science) has recently submitted an interim report regarding the monitoring study in lotic (flowing) (e.g. rivers) and lentic water bodies (e.g. ponds) as well as sediment in each of the following states: California, Mississippi, and Michigan. More details of the report are provided in the following sections. The final monitoring report is expected to be submitted by DAS by March 18, 2014 (USEPA 2011).  
        
Table 1. Tier II estimated drinking water concentrations (EDWCs) resulting from applications of methoxyfenozide (PRZM-EXAMS)
                            Drinking water source 
                                      Use
                                (modeled rate)
                           1-in-10 year acute (ppb)
                          1-in-10 year chronic (ppb)
                            30- year average (ppb)
                                 Surface water
                             (aerial application)
                                Globe Artichoke
              (0.25 lb a.i./A x 4 applic.; total of 1.0 lb/A/yr)
                                     77.7
                                     51.6
                                     37.4
                                 Surface water
                             (ground application)
                                Globe Artichoke
              (0.25 lb a.i./A x 4 applic.; total of 1.0 lb/A/yr)
                                     77.4
                                     50.4
                                     35.8
                    Tier I EDWCs for Groundwater (PRZM-GW)
                                 Crop/Scenario
                          Highest Daily value (ug/L)
                       Post Breakthrough Average (ug/L)
                  Average Simulation Breakthrough Time (days)
                          Fruiting Vegetable/WI corn
                                      251
                                      214
                                    8684.63
Value in bold show the highest EDWC, which is recommended for use in HED's dietary risk assessment. 

use Characterization

	Methoxyfenozide is currently registered for use on dried peas and beans (except soybean), pomegranate, popcorn, citrus, corn, cotton, cucurbit vegetables, grapes, pome and stone fruits, root vegetables, spearmint and peppermint, berries (including strawberries and cranberries), tree nuts, leafy vegetables, globe artichokes, legume vegetables, a variety of tropical fruits, black-eyed and southern peas, bushberries, dry beans, grass forage, peanuts, tuberous and corm vegetables, non-grass forage, avocado, green onion, ornamentals, and root vegetables.  Methoxyfenozide is the sole active ingredient in Intrepid[(R)] 2F and Intrepid 80WSP, and it is applied aerially or through ground equipment.  
      The maximum single application rates for the proposed IR-4 new uses are listed in Table 2.  
      
Table 2.  Summary use information for methoxyfenozide proposed new uses, based on Intrepid[(R)]2F supplemental label (EPA Reg. No. 62719-442).
                                      Use
            Max. Single Application Rate             (lbs. a.i./A)
                           Max. No. of Applications 
                Max. Seasonal[1] Application Rate (lbs. a.i./A)
                       Min. Application Interval (days)
                              Application Method
                                   Comments
                               Herb subgroup 19A
                                     0.25
                             Not stated on label.
                                     1.0 
                                      10
                         Ground spray (foliar)/Aerial
                                       
                                     Dates
                                     0.31
                             Not stated on label.
                                     1.0 
                                      10
                             Ground spray (foliar)
                                       
                                    Sorghum
                                     0.16
                             Not stated on label.
                                     0.75 
                                      10
                         Ground spray (foliar)/Aerial
Min application interval was only specified for beet armyworm and fall armyworm
                         Fruiting vegetable group 8-10
                                     0.25
                             Not stated on label.
                                      1.0
                                       7
                         Ground spray (foliar)/Aerial
                                       
                            Pome fruit group 11-10
                                     0.25
                             Not stated on label.
                                     1.0 
                                      10
                         Ground spray (foliar)/Aerial
Aerial application is allowed only for the last two applications prior to harvest
                         Caneberries subgroups 13-07 A
                                     0.25
                                       3
                                     0.75 
                                       7
                         Ground spray (foliar)/Aerial
                                       
                            Berry subgroups 13-07 G
                                     0.19
                             Not stated on label.
                                     1.0 
                                      10
                         Ground spray (foliar)/Aerial
                                       
                      Small fruit vine subgroups 13-07 F
                                     0.25
                             Not stated on label.
                                     0.75 
                                      10
                         Ground spray (foliar)/Aerial
                                       
                             Tropical tree fruits
                                     0.25
                                       5
                                     1.0 
                                       6
                         Ground spray (foliar)/Aerial
                                       
[1]For the purposes of this assessment, the maximum annual use rate was assumed to be equal to the reported "per season" rate (i.e., it was assumed only one crop per year would be grown).  Use on more than one crop per year (either the same crop or other crops with registered methoxyfenozide uses) on the same site may require further assessment to determine new estimated drinking water concentrations.
      
Environmental fate and transport characterization
      
      Methoxyfenozide is very persistent (t1/2 = 1 to 3 years in soil and water) and moderately mobile (Koc = 219  -  922 L/kgoc in various soils).  It is stable to photolysis and hydrolysis, is not significantly volatile, and degrades only very slowly by microbial activity.  Degradates are predominantly RH-117236 (3,5-Dimethylbenzoic acid N-tert-butyl-N'-(3-hydroxy-2-1nethylbenzoyl)hydrazide) and RH-131154 (3-[N-tert-butyl-N'-(3-methoxy-2-methylbenzoyl)-hydrazinocarbonyl]-5-methylbenzoaicci d), but these were only found at low concentrations (less than 10% of the applied radioactivity)  in submitted studies.  Because of its resistance to degradation and its mobility, methoxyfenozide has the potential to accumulate and to move off the site of application by leaching and erosion/runoff.  Table 3 summarizes the physico-chemical properties of methoxyfenozide.  For further details on the environmental fate and transport of methoxyfenozide, please refer to DP Barcode D249466.

Table 3.  General Chemical Properties and Environmental Fate Parameters of Methoxyfenozide.
Chemical/Fate Parameter
Value
Source
                                 Chemical name
n-tert-butyl-N'-[2-methyl-3-methoxybenzoyl]-3,5-dimethylbenzohydrazide
D249466
                                Molecular mass
368 g/mol
D249466
                             Vapor pressure (25C)
2.0 x 10[-8] torr
D249466
                               Solubility  (25C)
3.3 mg/L
D249466
                   Octanol-water partition coefficient (Kow)
10[3.72]
D249466
             Organic carbon partitioning coefficient (Koc, L/kgoc)
267, 922, 678, 219, 365 
MRID 44144433
                    Soil partition coefficient  (Kd, L/kg)
4.2, 1.1, 1.2, 6.2, 3.8
MRID 44144433
                       Hydrolysis half-life (pH 5, 7, 9)
Stable
MRID 44144430
                         Aqueous photolysis half-life
Stable
MRID 44617805
                           Soil photolysis half-life
Stable
MRID 44617806
                       Aerobic soil metabolism half-life
573, 1100, 772, 336 d
MRIDs 44617808, 44617807, 4414432
                     Aerobic aqueous metabolism half-life
387, 962 d
MRID 44617809
                    Anaerobic aqueous metabolism half-life
654 d
MRID 44617810
                    Terrestrial field dissipation half-life
237, 139, 151, 92 d
MRID 44617812, 44617811
      
drinking water modeling

      EDWCs were generated using EFED's standard suite of models.  The proposed new IR-4 uses on herb subgroup 19A (except chives), date, sorghum, pea and bean subgroup 6C (except blackeyed and southern pea), fruiting vegetable group 8-10, pome fruit group 11-10, berry subgroups 13-07 A, F & G, and tropical tree fruits (sugar apple, cherimoya, atemoya, custard apple, ilama, soursop, and biriba) were assessed. Additionally, the globe artichoke use that was assessed in the last DWA (USEPA 2011) was included in this assessment for characterization purposes.

 Models

	The Pesticide Root Zone Model (PRZM 3.12.2 dated May 12, 2005) and Exposure Analysis Modeling System (EXAMS 2.98.04.06 dated April 25, 2005) are simulation models coupled with the input shell PE 5.0 (US EPA, 2006) to generate EDWCs of methoxyfenozide residues that may occur in surface water used as drinking water.  The PRZM model simulates transformation on and movement from an agricultural field of a pesticide following its application.  The EXAMS model simulates resulting pesticide concentrations in an adjacent waterbody.  For surface water/drinking water, EFED assumes the field to constitute a standard watershed 172.8 ha in area draining into an adjacent drinking water reservoir 5.26 ha in area, with a mean depth of 2.74 m.  A more detailed description of this "Index Reservoir" and its watershed can be found in Jones et al., 1998.  The PRZM and EXAMS models and their user's manuals may be downloaded from the U.S. Environmental Protection Agency (EPA) Water Models web-page (US EPA, 2006).  Percent Cropped Area (PCA) adjustment factors that account for the maximum percent area within a watershed that may be planted with the modeled crop are used to adjust concentrations estimated by PRZM and EXAMS (USEPA, 2012).
	Tier 1 groundwater EDWCs for methoxyfenozide, resulting from the chemical's use on fruiting vegetable, were derived with PRZM-GW (Pesticide Root Zone Model for Groundwater, version 1.0, August 31, 2012), using the PRZM-GW GUI (Graphical User Interface, version 1.0, August 31, 2012).  PRZM-GW is a one-dimensional leaching model that estimates potential concentrations of pesticides in groundwater.  It accounts for pesticide fate in the crop root zone by simulating pesticide transport and degradation through the soil profile, after a pesticide is applied to an agricultural field.  PRZM-GW was used to simulate 30 years of repeated methoxyfenozide application in six standard scenarios: Delmarva, GA coastal, NC cotton, WI corn, FL potato and FL citrus.  Each scenario represents a different location known to be vulnerable to groundwater contamination.  The input parameters are found in Table 6.  PRZM-GW outputs represent pesticide concentrations in a vulnerable groundwater supply located directly beneath an agricultural field (Table 9).  The results show the greatest single-day maximum concentration for the WI corn scenario.  
	Additionally, tier 1 groundwater EDWCs for methoxyfenozide were developed using the Screening Concentration In GROund Water (SCI-GROW v2.3, Jul. 29, 2003) model.  SCI-GROW is a regression model used as a screening tool to estimate pesticide concentrations found in ground water used as drinking water.  SCI-GROW was developed by fitting a linear model to ground water concentrations with the Relative Index of Leaching Potential (RILP) as the independent variable.  Ground water concentrations were taken from 90-day average high concentrations from Prospective Ground Water monitoring studies.  The RILP is a function of a pesticide's aerobic soil metabolism and soil-water partition coefficient.  The output of SCI-GROW represents concentrations of methoxyfenozide that might occur in shallow, unconfined aquifers under sandy soils.  Such locations are representative of groundwater that is likely to be maximally vulnerable to pesticide contamination, and that may serve as a drinking water supply.  The SCI-GROW model and user's manual may also be downloaded from the EPA Water Models web-page (US EPA, 2006).  
      
Input Parameters

	Input parameters for the PRZM/EXAMS, PRZM-GW and SCI-GROW models are listed in Tables 4 -5, 6 and 7, respectively.  Explanations of various model input parameters are discussed below. 

Table 4.  PRZM and EXAMS application-specific input parameters for methoxyfenozide  
                                     Uses
                                 PRZM Scenario
                          Max App rate (lbs ai/A)[1]
                                    # Apps
                                   Interval
                                    (days)
                              % Drift/ Efficiency
                                 CAM/IPSCND[2]
                         Date of 1[st] of application
                              Herb Subgroup 19 A
                                    OR mint
                                     0.25
                                       4
                                      10
                                   0.16/0.95
                                      2/3
                                 April 15[th] 
                                       
                                    OR mint
                                     0.25
                                       4
                                      10
                                  0.064/0.99
                                      2/3
                                 April 15[th]
                                   Dates[3]
                           CA citrus with irrigation
                                     0.31
                                       3
                                      10
                                  0.064/0.99
                                      2/3
                                  Aug 1[st] 
                                  Sorghum[4]
                                  KS sorghum 
                                     0.16
                                       4
                                      10
                                   0.16/0.95
                                      2/3
                                  June 1[st]
                                       
                                  KS sorghum
                                     0.16
                                       4
                                      10
                                  0.064/0.99
                                      2/3
                                  June 1[st]
                         Fruiting vegetable group 8-10
                                   PA tomato
                                     0.25
                                       4
                                       7
                                   0.16/0.95
                                      2/3
                                 June 30[th] 
                                       
                                   PA tomato
                                     0.25
                                       4
                                       7
                                  0.064/0.99
                                      2/3
                                  June 30[th]
                                       
                                   FL tomato
                                     0.25
                                       4
                                       7
                                   0.16/0.95
                                      2/3
                                 Sep 10[th]  
                                       
                                   FL tomato
                                     0.25
                                       4
                                       7
                                  0.064/0.99
                                      2/3
                                  Sep 10[th] 
                                       
                                   FL pepper
                                     0.25
                                       4
                                       7
                                   0.16/0.95
                                      2/3
                                  Nov 1[st] 
                                       
                                   FL pepper
                                     0.25
                                       4
                                       7
                                  0.064/0.99
                                      2/3
                                   Nov 1[st]
                           Pome fruit[5] group 11-10
                                   PA apple
                                     0.25
                                       4
                                      10
                                   0.16/0.95
                                      2/3
                                  May 16[th] 
                                       
                                   PA apple
                                     0.25
                                       4
                                      10
                                  0.064/0.99
                                      2/3
                                  May 16[th]
                           Caneberries subgroups[6] 
                                    13-07 A
                                  OR berries
                                     0.25
                                       3
                                       7
                                   0.16/0.95
                                      2/3
                                  May 1[st] 
                                       
                                  OR berries
                                     0.25
                                       3
                                       7
                                  0.064/0.99
                                      2/3
                                  May 1[st] 
                               Berry subgroups 
                                    10-07 G
                                FL strawberries
                                     0.19
                                       5
                                      10
                                   0.16/0.95
                                      2/3
                                 Nov 10[th]  
                                       
                                FL strawberries
                                     0.19
                                       5
                                      10
                                  0.064/0.99
                                      2/3
                                 Nov 10[th]  
                          Small fruit vine groups[6] 
                                    13-07 F
                                  OR berries
                                     0.25
                                       3
                                      10
                                   0.16/0.95
                                      2/3
                                  May 1[st] 
                                       
                                  OR berries
                                     0.25
                                       3
                                      10
                                  0.064/0.99
                                      2/3
                                  May 1[st] 
                             Tropical tree fruits
                                  FL avocado
                                     0.25
                                       4
                                       6
                                   0.16/0.95
                                      2/3
                                  Mar 1[st] 
                                       
                                  FL avocado
                                     0.25
                                       4
                                       6
                                  0.064/0.99
                                      2/3
                                   Mar 1[st]
   1. Maximum application rates were multiplied by 1.12 to convert to kg a.i./ha for use in modeling.
   2. Chemical application method (CAM) and post-harvest foliar pesticide disposition (ISPCND). CAM 2 = foliar application; ISPCND 3= the pesticide is left as-is on foliage.
   3. Three applications were modeled using 0.31 lb a.i./A, and a fourth application using 0.07 lb a.i./A
   4. Four applications were modeled using 0.16 lb a.i./A, and a fifth application using 0.11 lb a.i./A
   5. Previous assessments used 6 applications/yr and a higher application rate.  Current label reflects a slightly lower single application rate of 0.25 lb a.i./A and a maximum of 1.0 lb a.i./acre/season. 
   6. There is not a standard scenario available for either the caneberry or small fruit vine groups.  The OR berries OP scenario was used because this scenario provides the best representation of agricultural practices for these crops from among the available EFED-approved PRZM scenarios. 

Table 5.  PRZM/EXAMS chemical-specific input parameters for methoxyfenozide.  
Input Parameter
                                     Value
Comment
Source
Molecular Mass (g/mol)
                                      368
Product chemistry data
D249466
Vapor Pressure at 25°C (torr)
                                 2.0 x 10[-8]
Product chemistry data
D249466
Solubility in Water at 25[o]C (mg/L)
                                      3.3

D249466
Organic Carbon Partition Coefficient (KOC) (L/kgOC)
                                      490
Represents the average KOC.
MRID 44144433
Aerobic Soil Metabolism Half-life (days)
                                      960
Represents the 90[th] %-ile confidence bound on the mean half-life.
MRIDs 44617808, 44617807, 4414432
Aerobic Aquatic Metabolism Half-life (days)
                                     1559
Represents the 90[th] %-ile confidence bound on the mean half-life.
MRID 44617809
Anaerobic Aquatic Metabolism Half-life (days)
                                     1962
3x one data point
MRID 44617810 
Hydrolysis Half-lives (days)
                                       0
Stable
MRID 44144430
Aqueous Photolysis
Half-life (days)
                                       0
Stable
MRID 44617805
Foliar Degradation Half-life (days)
                                       0
Stable, no data
Default
Foliar Washoff Extraction Coefficient (cm[-1])
                                      0.5

Default

Table 6. PRZM-GW Input Parameters
                               Parameter (units)
                                  Input Value
                                  Data Source
                               Application Rate
                                0.25 lbs a.i./A
                                     Label
                            Number of Applications
                                       4
                                     Label
                               Application Dates
                                  (month/day)
                          06/30; 07/07; 07/14; 07/21
                                  IPM center
                        Annual Application Retreatment
                                Once every year
                                       
                          Hydrolysis Half-life (days)
                                  Stable (0)
                                 MRID 44144430
                       Soil Metabolism Half-life (days)
             960 (90[th] percentile confidence bound on the mean)
                       MRIDs 44617808, 44617807, 4414432
                            average of Koc (mL/goc)
                                      490
                                 MRID 44144433

Table 7.  SCI-GROW input parameters for methoxyfenozide.  
Input Parameter
Value
Comment
Source
Application Rate (lbs a.i./A)
See Table 4
Label directions
Proposed and current labels
Applications per Year
See Table 4
Label directions
Proposed and current labels
Organic Carbon Partition Coefficient (kOC) (L/kgOC)
219
Lowest KOC value;  > 3x variation in data
MRID 44144433
Aerobic Soil Metabolism
Half-life (days)
695
Average of 4 values
MRIDs 44617808, 44617807, 4414432

      Ten currently approved PRZM scenarios were used in the modeling for new uses: OR mint, CA citrus, KS sorghum, MI beans, PA tomato, FL pepper, PA apple, OR berries, FL strawberries and FL avocado.  The chemical application method (CAM) parameter was derived from information on the supplemental label (Intrepid 2F), as were the application rate and retreatment interval.  The retreatment interval represents the minimum amount of time required between applications of the pesticide.  Most crops were modeled using aerial and ground application except dates, for which only ground application was modeled.
      Table 4 lists the specific PRZM/EXAMS scenarios modeled to represent the new uses.  The highest simulated single application rate was 0.31 lb a.i./acre on dates, which was represented using the CA citrus scenario because no approved date scenario exists, and 100% of dates in the U.S. are cultivated in California.  Similarly, there are no approved standard scenarios for caneberries or small fruit vine group 10-07 F, therefore the Oregon berry OP (organophosphate) scenario was used because this scenario provides the best representation of agricultural practices for these crops from among the available approved PRZM scenarios.  The application dates for the scenarios were chosen according to the crops' profiles, lifecycle, and/or time when heavy pest pressure is likely to appear (USDA Crop Profiles). 
	Chemical property model input values were chosen in accordance with EFED's current input parameter guidance (USEPA 2009 and USEPA 2012b).  The upper 90% confidence limit on the mean half-life (960 d) was selected to represent aerobic soil metabolism in surface water modeling and PRZM-GW, and the median half-life (695 d) was used in SCI-GROW modeling, in accordance with the input parameter guidance.  Both hydrolysis and photolysis were modeled as stable.  The upper 90% confidence limit on the mean half-life (1559 d) was selected to represent aerobic aquatic metabolism, and 3 times the anaerobic aquatic metabolism half-life was used to represent anaerobic aquatic metabolism since only one measured value (1962 d) was available.  The default all-agriculture PCA of 0.91 was used for all simulations (USEPA 2012a).  The mean Koc (490 L/kgoc) was used for PRZM-GW and PRZM/EXAMS modeling, whereas the lowest Koc value (219 L/kgoc) was used in the SCI-GROW modeling. 

Modeling Results

      The EDWCs for application of methoxyfenozide on the new uses and the previously evaluated globe artichoke use are listed in Table 8.  The EDWCs obtained for the globe artichoke use pattern as represented by the CA lettuce scenario, generated the highest EDWCs for both surface water and groundwater, followed by the fruiting vegetable group uses as represented by the FL tomato scenario.  EDWCs for Tier I PRZM-GW are shown in Table 9.  The highest EDWCs are associated with the WI corn scenario, and are recommended for use in HED's dietary assessment.  Refer to Attachment 1 for more details on the PRZM/EXAMS, PRZM-GW and SCI-GROW modeling outputs.
       
Table 8. Maximum Concentrations of methoxyfenozide: Tier II EDWCs for surface water. Bolded values are the maximum values found for the crops[1][,2]
                                      Use
                              Application Method
                                     PRZM
                                   Scenario
                           Maximum Application Rate
                              [lb. a.i./A; kg/ha]
                                  No. of Apps
                              1-in-10 Year Acute
                                    (ug/L) 
                             1-in-10 Year Chronic
                                   (ug/L) 
                           30- Year Average (ug/L)
                               Herb Subgroup 19
                                    aerial
                                    OR mint
                                   0.25/0.28
                                       4
                                     12.6
                                      7.2
                                      6.2
                                       
                                    ground
                                    OR mint
                                   0.25/0.28
                                       4
                                      8.3
                                      4.7
                                      3.7
                                     Dates
                                    ground
                           CA citrus with irrigation
                                   0.31/0.35
                                       3
                                     16.5
                                     14.6
                                     11.7
                                    Sorghum
                                    aerial
                                  KS sorghum
                                   0.16/0.18
                                       5
                                     28.5
                                     13.1
                                      9.9
                                       
                                    ground
                                  KS sorghum
                                   0.16/0.18
                                       5
                                     27.7
                                     12.5
                                      9.1
                                       
                           Fruiting vegetable group
                                     8-10
                                       
                                    aerial
                                   PA tomato
                                   0.25/0.28
                                       4
                                     34.3
                                     17.2
                                     11.7
                                       
                                    ground
                                   PA tomato
                                   0.25/0.28
                                       4
                                     32.9
                                     16.1
                                     10.3
                                       
                                    aerial
                                   FL tomato
                                   0.25/0.28
                                       4
                                     75.6
                                     13.3
                                      9.0
                                       
                                    ground
                                   FL tomato
                                   0.25/0.28
                                       4
                                     75.9
                                     13.3
                                      8.8
                                       
                                    aerial
                                   FL pepper
                                   0.25/0.28
                                       4
                                     51.6
                                     11.7
                                      6.5
                                       
                                    ground
                                   FL pepper
                                   0.25/0.28
                                       4
                                     51.0
                                     11.6
                                      6.2
                            Pome fruit group 11-10
                                    aerial
                                   PA apple
                                   0.25/0.28
                                       4
                                     39.5
                                     20.1
                                     14.1
                                       
                                    ground
                                   PA apple
                                   0.25/0.28
                                       4
                                     38.9
                                     18.4
                                     12.2
                             Caneberries subgroups
                                    13-07 A
                                    aerial
                                 OR berries[3]
                                   0.25/0.28
                                       3
                                      9.2
                                      6.0
                                      5.3
                                       
                                    ground
                                 OR berries[3]
                                   0.25/0.28
                                       3
                                      6.8
                                      4.2
                                      3.5
                                Berry subgroups
                                    10-07 G
                                    aerial
                                FL strawberries
                                   0.19/0.21
                                       5
                                     26.1
                                      6.5
                                     36.8
                                       
                                    ground
                                FL strawberries
                                   0.19/0.21
                                       5
                                     24.9
                                      6.0
                                      4.1
                            Small fruit vine groups
                                    13-07 F
                                    aerial
                                 OR berries[3]
                                   0.25/0.28
                                       3
                                      9.1
                                      6.2
                                      5.4
                                       
                                    ground
                                 OR berries[3]
                                   0.25/0.28
                                       3
                                      7.0
                                      4.4
                                      3.6
                             Tropical tree fruits
                                    aerial
                                  FL avocado
                                   0.25/0.28
                                       4
                                     22.3
                                     17.8
                                     12.3
                                       
                                    ground
                                  FL avocado
                                   0.25/0.28
                                       4
                                     15.8
                                     13.2
                                      7.7
                                Globe Artichoke
                                    aerial
                                  CA lettuce
                                   0.25/0.28
                                       4
                                     77.7
                                     51.6
                                     37.4
                                       
                                    ground
                                  CA lettuce
                                   0.25/0.28
                                       4
                                     77.4
                                     50.4
                                     35.8
      1. The annual rate for these crops do not exceed 1.0 lb a.i./acre/season.
      2. PCA values are 0.91 for all the crops. 
Bolded values represent the highest EDWCs for methoxyfenozide.
         
         

Table 9. PRZM-GW (30 years simulation) and SCI-GROW EDWCs (1 year) in Groundwater Resulting from the Use of Methoxyfenozide.
                                 Crop/Scenario
                          Highest Daily value (ug/L)
                       Post Breakthrough Average (ug/L)
                  Average Simulation Breakthrough Time (days)
                         Fruiting Vegetable/FL potato 
                                     30.4
                                     30.3
                                   10568.95
                         Fruiting Vegetable/ FL citrus
                                      154
                                      139
                                    4243.13
                          Fruiting Vegetable/Delmarva
                                      147
                                      133
                                    4264.59
                         Fruiting Vegetable/ NC cotton
                                      180
                                      157
                                    5020.61
                         Fruiting Vegetable/GA coastal
                                     62.7
                                     52.9
                                    8983.61
                          Fruiting Vegetable/WI corn
                                      251
                                      214
                                    8684.63
                                SCI-GROW EDWCs 
                         Globe Artichoke (1.0 lb/A/yr)
                                  4.13 ug/L
Bolded value represents the highest EDWC for methoxyfenozide

Monitoring Data

   Methoxyfenozide is not identified as a cause of impairment for any water bodies listed as impaired under section 303(d) of the Clean Water Act.  The following databases and sources were searched on February 8, 2013 for monitoring information on methoxyfenozide:
   * The United States Geological Survey (USGS) National Water-Quality Assessment (NAWQA) Program Data Warehouse (http://infotrek.er.usgs.gov/traverse/f?p=NAWQA:HOME:1405517206944567)[2] 
   * The USGS National Stream Quality Accounting Network (NASQAN) program (http://water.usgs.gov/nasqan/)[3]
No monitoring data for methoxyfenozide were found, as these programs did not include this compound in their lists of analytes.  EFED is not aware of water or sediment monitoring data on methoxyfenozide from any other sources.  Due to uncertainties identified during the Section 3 Registration process, methoxyfenozide is conditionally registered.  One of the outstanding conditional registration requirements is:
      
      Three years after use, obtaining approval for and conducting monitoring of surface water and sediment in a representative sample of high use areas in proximity to surface water. 
      
      DAS (Dow Agricultural Science) has agreed to sample for methoxyfenozide over a two-year period in lotic (flowing) water bodies (e.g. rivers) and lentic water bodies (e.g. ponds) and sediment in each of the following states: California, Mississippi, and Michigan with the Agency's guidance (USEPA 2011).  A summary of interim sampling results is provided below in Table 10.  For more information refer to USEPA, 2013.  The final monitoring report is expected to be submitted by DAS by March 18, 2014 (USEPA 2011).  

Table 10. Summary of Interim Sampling Results
                                     State
                                  Parameters
                                     Lotic
                                    Lentic
                                       
                                       
                                 Water (ug/L)
                               Sediment (ug/kg)
                                 Water (ug/L)
                               Sediment (ug/kg)
                                      CA
                                Detects/Samples
                                     Range
                                  Mean/Median
                                     72/72
                           0.018  -  1.0 0.14/0.061
                                      0/4
                                     1/10
                                     0.017
                                     0/10
                                      MI
                                Detects/Samples
                                     Range
                                  Mean/Median
                                     0/14
                                      0/2
                                     8/11
                                0.025  -  0.85
                                   0.19/0.06
                                     1/11
                                      3.4
                                      MS
                                Detects/Samples
                                     Range
                                  Mean/Median
                                     38/48
                                0.016  -  0.181
                                  0.036/0.025
                                      0/4
                                     8/10
                                0.019  -  0.233
                                  0.056/0.024
                                     0/10
For water, the limit of detection (LOD) was 0.015 ug/L and the limit of quantitation (LOQ) was 0.05 ug/L.  For sediment, the LOD was 3 ug/kg and the LOQ was 10 ug/kg.

Conclusions

      The EDWCs reported here are based on currently registered uses, and the following new uses: herb subgroup 19A (except chives) date, sorghum, fruiting vegetable group 8-10, pome fruit group 11-10, berry subgroups 13-07 A, F & G, and tropical tree fruits (sugar apple, cherimoya, atemoya, custard apple, ilama, soursop, and biriba).  The fruiting vegetable group 8-10 use yielded the highest value for surface water EDWCs from the new uses.  However, the globe artichoke use generated the highest EDWCs from all currently registered uses of methoxyfenozide for surface water.  Table 1 reflects the most conservative (highest) EDWCs, which are recommended for use in HED's dietary assessment. 
      There remains an outstanding data requirement for monitoring of surface water and sediment in a representative sample of high use areas in close proximity to surface water. Additionally, EFED continues to have concerns that the persistence of methoxyfenozide makes it plausible that this compound may pose a greater long-term drinking water exposure concern than what is suggested by this screening-level assessment.  Given its persistence and mobility, once introduced into the environment, this compound may enter sensitive environmental compartments such as aquatic sediment, and persist for extended periods of time.  As such, EFED has concerns regarding the potential for long-term drinking water exposure associated with the use of this chemical.  
      There is also a continuing concern regarding label language.  The proposed label currently specifies a maximum application rate on a seasonal basis rather than an annual basis.  Given the persistence of methoxyfenozide, repeated applications on crops for which there is more than one growing season per year could result in greater accumulation and higher aquatic concentrations than reported in this assessment.
 

References

USEPA. 2002. SCIGROW: Users Manual. Online at: 	http://www.epa.gov/oppefed1/models/water/#scigrow

USEPA. 2005. PRZM 3.12.2: Users Manual. Online at:
	http://www.epa.gov/oppefed1/models/water/#przm 

USEPA. 2005. EXAMS 2.98.04.06: Users Manual. Online at:
	http://www.epa.gov/oppefed1/models/water/#exams 

USEPA. 2006. Water models PE Version 5: User Manual. Online at:
	http://www.epa.gov/oppefed1/models/water/pe5_user_manual.htm  

USEPA.  2009.  Guidance for Selecting Input Parameters in Modeling the 	Environmental 	Fate and Transport of Pesticides.  U.S. Environmental Protection 	Agency, 	Office of chemical Safety and Pollution Prevention, Office of Pesticide 	Programs, Environmental Fate and Effects Division, Oct. 22, 2009.  Online at: 	http://www.epa.gov/oppefed1/models/water/input_parameter_guidance.htm

USEPA. 2011. DP Barcode: D394308. Review of Addendum to Site Selection Report 	with Recommended Alternate Sampling Sites for Lentic Water Bodies in 	California (MRID 47809904) from Environmental Fate and Effects Division 	(EFED) to Pesticide Re-evaluation Division (PRD) from Chuck Peck to Clayton 	Myers. October 12, 2011.

USEPA. 2012a. Development and Use of Percent Cropped Area Adjustment Factors in 	Drinking Water Exposure Assessments. U.S. Environmental Protection Agency, 	Office of chemical Safety and Pollution Prevention, Office of Pesticide Programs, 	Environmental Fate and Effects Division, September 9, 2010. Online at:  	http://www.epa.gov/oppefed1/models/water/pca_adjustment_dwa.html 

USEPA. 2012b. Guidance for Selecting Input Parameters for Modeling Pesticide 	Concentrations in Groundwater Using the Pesticide Root Zone Model. Office of 	chemical Safety and Pollution Prevention, Office of Pesticide Programs, 	Environmental Fate and Effects Division, and Health Canada  Pesticide 	Management Regulatory Agency, Oct.15, 2012.  

USEPA. 2013. Methoxyfenozide: Review of Interim Report on Surface Water and 	Sediment Monitoring (MRID 49050001). Office of 	Chemical Safety and 	Pollution Prevention, Office of Pesticide Programs, From Environmental Fate and 	Effects Division (EFED) to Registration Division (RD); from Chuck Peck 	to 	Mark Suarez. March 26, 2013.

USEPA MEMORANDUM. DP Barcode: D249466. Methoxyfenozide: Tier II Drinking 	Water EECs for Use in the Human Health Risk Assessment from environmental 	fate and effects division (EFED) to Registration Division (RD), from Dirk F. 	Young to Joseph Tavano and Arnold Layne, July 21, 1999.

US EPA MEMORANDUM. DP Barcode: 331949, 340542. Drinking Water Assessment 	for the Section 3 New Use Petitions for the Use of Methoxyfenozide on vegetable 	(tuberous and corm subgroup 1 D), bushberry (subgroup 13B), dry beans, grass, 	forage, fodder and hay (group 17), peanut, green onion (subgroup 3B), avocado, 	guava and related tropical fruits, from environmental fate and effects division 	(EFED) to Registration Division (RD), from Marietta Echeverria to John Redden, 	October 18, 2007.

US EPA MEMORANDUM. DP Barcode: D388876. Drinking Water Assessment for the 	IR-4 New Use Petitions for the Use of Methoxyfenozide on Root Vegetables for 	Crop Subgroup 1B (Except Sugar Beets) and Citrus Crop Group 10 from 	environmental fate and effects division (EFED) to Registration Division (RD), 	from Karen Milians to Richard Gebken August 17, 2011.

USDA Crop Profiles. Available online at: 
	http://www.ipmcenters.org/cropprofiles/CP_form.cfm 

Jones, R. David, Abel, Sidney, Effland, William, Matzner, Robert, and Parker, Ronald. 	1998. An Index Reservoir for Use in Assessing Drinking Water Exposure. 	Chapter IV in Proposed Methods for Basin-Scale Estimation of Pesticide 	Concentrations in Flowing Water and Reservoirs for Tolerance Reassessment., 	presented to the FIFRA Science Advisory Panel, July 29, 1998. Attachment 1. Modeling Input and Output: 
Scenario/application rate: Globe Artichoke/0.25 lb ai/A
stored as caartnewae.out
Chemical: methox
PRZM environment: CAlettuceSTD.txt	modified Tueday, 8 January 2013 at 16:16:28
EXAMS environment: ir298.exv	modified Tueday, 26 August 2008 at 05:14:07
Metfile: w23273.dvf	modified Wedday, 3 July 2002 at 08:04:22
Water segment concentrations (ppb)

Year	Peak	96 hr	21 Day	60 Day	90 Day	Yearly
1961	46.36	45.71	43.36	27.23	19.11	6.558
1962	53.99	53.41	51.58	47.41	45.66	36.11
1963	57.25	56.63	54.66	52.15	51.3	40.88
1964	63.73	63.03	60.56	55.6	46.36	34.45
1965	74.16	73.68	70.72	55.82	46.57	40.31
1966	70.48	69.79	67.07	59.87	57.13	47.92
1967	71.34	70.71	68.53	64.07	62.4	50.46
1968	47.98	47.55	46.35	44.96	42.16	37.33
1969	49.61	49.33	48.32	45.61	43.73	36.54
1970	73.67	72.9	67.06	50.13	42.4	37.21
1971	69.62	68.95	66.3	61.3	58.22	48.13
1972	65.75	65.02	62.31	54.13	45.24	36.15
1973	57.86	57.35	55.38	53.54	51.58	43.3
1974	98.48	97.74	93.38	65.17	54.86	47.75
1975	94.59	93.63	89.9	87.9	85.12	64.88
1976	86.34	85.8	82.86	76.74	72.94	60.33
1977	77.07	76.65	74.39	69.61	66.53	57.03
1978	72.87	72.19	69.49	64.4	62.47	54.21
1979	58.86	58.5	57.57	55.75	54.1	44.28
1980	65.12	64.59	62.65	60.68	58.62	46.84
1981	65.9	65.5	63.26	61.26	59.22	47.7
1982	46.03	45.64	44.16	42.18	40.49	36.48
1983	45.57	45.25	44.31	42.45	41.29	36.91
1984	48.94	48.46	44.03	36.03	34.64	30.79
1985	52.59	52.07	50.11	41.56	39.52	34.55
1986	49.29	48.89	47.38	44.75	44.18	39.05
1987	51.42	50.99	47.71	45.15	42.53	38.99
1988	52.45	51.96	49.8	47.08	45.33	39.16
1989	50.58	50.14	48.42	45.29	43.27	34.47
1990	32.88	32.65	31.95	31.31	30.29	25.83

Sorted results
Prob.	Peak	96 hr	21 Day	60 Day	90 Day	Yearly
0.032258064516129	98.48	97.74	93.38	87.9	85.12	64.88
0.0645161290322581	94.59	93.63	89.9	76.74	72.94	60.33
0.0967741935483871	86.34	85.8	82.86	69.61	66.53	57.03
0.129032258064516	77.07	76.65	74.39	65.17	62.47	54.21
0.161290322580645	74.16	73.68	70.72	64.4	62.4	50.46
0.193548387096774	73.67	72.9	69.49	64.07	59.22	48.13
0.225806451612903	72.87	72.19	68.53	61.3	58.62	47.92
0.258064516129032	71.34	70.71	67.07	61.26	58.22	47.75
0.290322580645161	70.48	69.79	67.06	60.68	57.13	47.7
0.32258064516129	69.62	68.95	66.3	59.87	54.86	46.84
0.354838709677419	65.9	65.5	63.26	55.82	54.1	44.28
0.387096774193548	65.75	65.02	62.65	55.75	51.58	43.3
0.419354838709677	65.12	64.59	62.31	55.6	51.3	40.88
0.451612903225806	63.73	63.03	60.56	54.13	46.57	40.31
0.483870967741936	58.86	58.5	57.57	53.54	46.36	39.16
0.516129032258065	57.86	57.35	55.38	52.15	45.66	39.05
0.548387096774194	57.25	56.63	54.66	50.13	45.33	38.99
0.580645161290323	53.99	53.41	51.58	47.41	45.24	37.33
0.612903225806452	52.59	52.07	50.11	47.08	44.18	37.21
0.645161290322581	52.45	51.96	49.8	45.61	43.73	36.91
0.67741935483871	51.42	50.99	48.42	45.29	43.27	36.54
0.709677419354839	50.58	50.14	48.32	45.15	42.53	36.48
0.741935483870968	49.61	49.33	47.71	44.96	42.4	36.15
0.774193548387097	49.29	48.89	47.38	44.75	42.16	36.11
0.806451612903226	48.94	48.46	46.35	42.45	41.29	34.55
0.838709677419355	47.98	47.55	44.31	42.18	40.49	34.47
0.870967741935484	46.36	45.71	44.16	41.56	39.52	34.45
0.903225806451613	46.03	45.64	44.03	36.03	34.64	30.79
0.935483870967742	45.57	45.25	43.36	31.31	30.29	25.83
0.967741935483871	32.88	32.65	31.95	27.23	19.11	6.558

0.1	85.413	84.885	82.013	69.166	66.124	56.748
					Average of yearly averages:	41.1532666666667

Inputs generated by pe5.pl - Novemeber 2006

Data used for this run:
Output File: caartnewae
Metfile:	w23273.dvf
PRZM scenario:	CAlettuceSTD.txt
EXAMS environment file:	ir298.exv
Chemical Name:	methox
Description	Variable Name	Value	Units	Comments
Molecular weight	mwt	368	g/mol
Henry's Law Const.	henry		atm-m^3/mol
Vapor Pressure	vapr	2e-8	torr
Solubility	sol	3.3	mg/L
Kd	Kd		mg/L
Koc	Koc	490	mg/L
Photolysis half-life	kdp	0	days	Half-life
Aerobic Aquatic Metabolism	kbacw	1559	days	Halfife
Anaerobic Aquatic Metabolism	kbacs	1962	days	Halfife
Aerobic Soil Metabolism	asm	960	days	Halfife
Hydrolysis:	pH 7	0	days	Half-life
Method:	CAM	2	integer	See PRZM manual
Incorporation Depth:	DEPI	0	cm
Application Rate:	TAPP	0.28	kg/ha
Application Efficiency:	APPEFF	0.95	fraction
Spray Drift	DRFT	0.16	fraction of application rate applied to pond
Application Date	Date	16-4	dd/mm or dd/mmm or dd-mm or dd-mmm
Interval 1	interval	7	days	Set to 0 or delete line for single app.
app. rate 1	apprate	0.28	kg/ha
Interval 2	interval	7	days	Set to 0 or delete line for single app.
app. rate 2	apprate	0.28	kg/ha
Interval 3	interval	7	days	Set to 0 or delete line for single app.
app. rate 3	apprate	0.28	kg/ha
Record 17:	FILTRA	
	IPSCND	3
	UPTKF	
Record 18:	PLVKRT	
	PLDKRT	
	FEXTRC	0.5
Flag for Index Res. Run	IR	Reservoir
Flag for runoff calc.	RUNOFF	total	none, monthly or total(average of entire run)

           SCIGROW
                          VERSION 2.3
            ENVIRONMENTAL FATE AND EFFECTS DIVISION
                 OFFICE OF PESTICIDE PROGRAMS
             U.S. ENVIRONMENTAL PROTECTION AGENCY
                        SCREENING MODEL
                FOR AQUATIC PESTICIDE EXPOSURE
 
 SciGrow version 2.3
 chemical:Methoxyfenozide
 time is  1/ 3/2013  16:23:59
 ------------------------------------------------------------------------
  Application      Number of       Total Use    Koc      Soil Aerobic
  rate (lb/acre)  applications   (lb/acre/yr)  (ml/g)   metabolism (days)
 ------------------------------------------------------------------------
      0.250           4.0           1.000      2.19E+02      695.0
 ------------------------------------------------------------------------
 groundwater screening cond (ppb) =   4.13E+00 
 ************************************************************************

Note: The outputs for the scenarios mentioned here are attached on a separate file name: 121027_407566_DWAscenarios_041613.

\s

Fruiting Vegetable/FL potato (30 years simulation)
Fruiting Vegetable/FL citrus (30 years simulation)

Fruiting Vegetable/Delmarva (30 years simulation)

Fruiting Vegetable/ NC cotton (30 years simulation)

Fruiting Vegetable/GA coastal (30 years simulation)

Fruiting Vegetable/WI corn (30 years simulation)