                     U. S. ENVIRONMENTAL PROTECTION AGENCY
                            WASHINGTON D.C., 20460
                                                                      OFFICE OF
                              CHEMICAL SAFETY AND
                             POLLUTION PREVENTION
                                   OFFICE OF
                              CHEMICAL SAFETY AND
                             POLLUTION PREVENTION

                                                                PC Code: 122304
                                                             DP Barcode: 430356
MEMORANDUM
                                                                    May 5, 2016

SUBJECT:	Flupyradifurone: Tier II Drinking Water Exposure Assessment in support of the Proposed Use of Flupyradifurone on Ornamentals, Residential, Greenhouse, Nursery, Stone fruit C12-12, Caneberry 13-07A, Taro leaves, Turnip greens, Abiu, Akee Apple, Avocado, Bacury, Banana, Canistel, Cupuacu, Etambe, Jatoba, Kei apple, Langstat, Lanjut, Lucuma,Mabolo Mango, Mangosteen, Paho, Papaya, Pawpaw, Pelipisan, Pequi, Persimmon, Plantain, Pomegranate, Poshte, Quandong, Sapote, Sataw, Screw-pine, Star apple, Tamarind of the indies and Wild loquat.
TO:
               Johnnie Smith, Dietary Assessor
               Greg Akerman, Risk Assessor
               Christine Olinger, Branch Chief
               Risk Assessment Branch III
               Health Effects Division (7509P)
CC:
               Jessica Rogala, Risk Manager
               Venus Eagle, Product Manager
               Meredith Laws, Branch Chief
               Invertebrate-Vertebrate Branch 3
               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 Fate Scientist
               Katrina White, Ph.D., Risk Assessment Process Leader
	Environmental Risk Branch IV
	Environmental Fate and Effects Division (7507P)

APPROVED
BY:	Jean Holmes, DVM, MPH, Branch Chief
Environmental Risk Branch IV
	Environmental Fate and Effects Division (7507P)

EFED has reviewed the proposed new uses of flupyradifurone (PC Code 122304, 2(5H-(furanone), 4-{{(6-chloro-3-pyridinyl)methyl](2,2-difluoroethyl)amino]-, also known as BYI 02960) and degradate residues of concern for their potential concentrations in surface water and in groundwater.  The complete list of new uses can be found in Appendix A. Most uses have the same proposed maximum annual application rates of 0.18 lbs active ingredient per acre (lbs a.i./A) and 0.365 lbs a.i./A. This is the same maximum application rate simulated in the previous drinking water assessment.  The exceptions are turnip greens and taro leaves which have a yearly application rate of 0.044 lbs a.i./A and 0.007 lbs a.i./A, respectively.  The number of proposed crops or annual applications is not specified for many uses, and retreatment intervals range from "not specified" to 10 days.  The labels do include a maximum yearly application rate and thus the maximum number of applications per crop may be estimated by dividing the maximum crop application rate by the maximum single application rate.

In the previous drinking water assessment (DWA), estimated drinking water concentrations (EDWCs) of flupyradifurone in surface water and in ground water were generated based upon the Section 3 new chemical use registration (USEPA, 2014; DP 415166; Appendix B). EDWCs were calculated for total toxic residues (TTR) consisting of a combination of the parent and various potential residues of concern (M47, M48 and DFA): 1) parent plus M47 (BYI 02960-azabicyclosuccinamide) plus M48 (BYI 02960-succinamide) plus unextracted residues (referred to as "TTR-UN"), and 2) parent plus M47 plus M48 (referred to as "TTR").  EDWCs were also calculated for DFA alone (difluoroacetic acid).  The structures of M47 and M48 are similar to that of the parent, and they may thus possess a similar mode of action.  The structure of DFA is very different from that of the parent, and its mode of action and observed toxicity patterns are also different.

The maximum EDWCs for residues of flupyradifurone can be found in Table 1. Flupyradifurone plus M47 plus M48 plus unextracted residues for acute were: 112 ug/L for surface water (Rice Tier 1 Model) and 352 ug/L(3 growing seasons) for groundwater. The acute EDWCs for residues of DFA were 43 ug/L for surface water (based on the use pattern on cranberries) and 152 ug/L for groundwater. Please note that the cranberry use will not be supported by the registrant and that the current labels for new uses are unclear regarding some use parameters that were not evaluated for drinking water.

 EXECUTIVE SUMMARY

In the previous DWA (USEPA, 2014; DP 415166), a suite of models was used to estimate the EDWCs: Tier I Rice Model and Surface Water Concentration Calculator (SWCC) for surface water and PRZM-GW (Pesticide Root Zone Model for Groundwater, version 1.0, August 31, 2012) and Screening Concentration in Ground Water (SCI-GROW v2.3, Jul. 29, 2003) models for groundwater. The EDWCs reported in the assessment conducted in 2014 (Table 1 and 2) are greater than the newly-generated EDWCs for the new uses (See Table 3), therefore, Table 1 and Table 2 from USEPA 2014 are still recommended for the Health Effects Division's (HED) dietary risk assessment of flupyradifurone.

Table 1.  Tier I EDWCs for residues of flupyradifurone plus M47 plus M48 plus unextracted residues.
Source of Drinking Water (Model)
                TTR-UN concentration in drinking water (ug/L)

                                     Acute
                  Annual Average or Post Breakthrough Average
Surface Water (Modified Tier 1 Rice Model)
                                      112
                                      112
Surface water (PRZM/EXAMS)
                               46.1 ( 1 season)
                               47.7 (2 seasons)
                               52.5 (3 seasons)
                               13.9 ( 1 season)
                               20.1 (2 seasons)
                               22.3 (3 seasons)
Groundwater (PRZM-GW)
                                117 (1 season)
                               23.8 (2 seasons)
                                352 (3 seasons)
                                102 (1 season)
                                208 (2 seasons)
                                307 (3 seasons)
* All values reflect residues of flupyradifurone plus M47 plus M48 plus unextracted residues.

Table 2.  Tier I EDWCs for residues of Difluoroacetic acid (DFA).[1]
Source of Drinking Water (Model)
                  DFA concentration in drinking water (ug/L)

                                     Acute
                  Annual Average or Post Breakthrough Average
Surface Water (Modified Tier 1 Rice Model)
                                      43
                                      43
Surface water (PRZM/EXAMS)
                               7.35 ( 1 season)
                               8.18 (2 seasons)
                               9.71 (3 seasons)
                               4.34 ( 1 season)
                               5.12 (2 seasons)
                               7.74 (3 seasons)
Groundwater (PRZM-GW)
                                51.7 (1 season)
                                105 (2 seasons)
                                152 (3 seasons)
                                36.0 (1 season)
                               76.2 (2 seasons)
                                114 (3 seasons)

Table 3. EDWCs of Flupyradifurone plus M47 plus M48 plus unextracted residues in Surface Water. Two crops per year were assumed and foliar application only.
PRZM Scenario
                                 EDWC in ug/L

Peak
1-day
Annual Average
Overall Average
CA nursery
9.33
9.32
8.03
5.89
MI nursery
8.77
8.74
3.83
3.09
NJ nursery
9.68
9.63
3.55
2.37
OR nursery
5.33
5.31
2.90
2.42
FL nursery
14.0
13.6
3.19
2.87
TN nursery
10.3
10.1
3.02
1.63
NC apple
9.56
9.52
3.86
2.22
OR apple
4.05
4.03
2.22
1.78
PA apple
6.44
6.42
3.61
2.23
Application rate used was: 0.18 lbs a.i./A x 2 applications for a total of 0.365 lbs a.i./A per year. The Pesticide in Water Calculator version 1.52 was used to model surface water concentrations. Chemical inputs used were based on the previous DWA (USEPA, 2014)

When using the maximum application rate on nurseries and stone fruits (0.18 lbs a.i./A x 2 applications for a total of 0.365 lbs a.i./A per year of flupyradifurone) Tier I modeling resulted in a maximum concentration of 93 ug/L and a long-term mean (post-breakthrough) of 87.6 ug/L in groundwater (Appendix C).  The groundwater EDWCs were not recalculated as the numbers are not dependent on the PRZM-GW scenario used to simulate the use and the previous EDWC for groundwater can be relied upon.

 CONCLUSION

The EDWCs generated for the uses assessed in 2014 (Table 1 and 2) exceed the EDWCs generated for the newly proposed uses (See Table 3).  Accordingly, the concentrations reproduced in Table 1 and Table 2 continue to be recommended by EFED for use by the Health Effects Division (HED) in their dietary risk assessment of flupyradifurone.

 REFERENCES

USEPA. 2014. Drinking Water Exposure Assessment for the Section 3 New Chemical Registration for use of Flupyradifurone on a Variety of Agricultural Crops. From K. White to S. Funk, K. Rury, C. Olinger, J. Rogala and M. Laws. DP D415166, February 18, 2014)

                 Appendix A-Proposed Uses of Flupyradifurone
                                   Use Site
                             Max Single App. Rate
                                in lbs. a.i./A
                                 (kg a.i./ha)
                                   # of App
                                     Per*
                            Max App. Rate per year
                                  lbs. a.i./A
                                 (kg a.i./ha)
                                  MRI (days)
                          Type of application, label
                                 Ornamentals1
                                     0.18
                                    (0.20)
                                      NS
                                  (assumed 2)
                                     0.365
                                    (0.409)
                                      NS
                     Drench application and foliar, Altus

                                Residential[1]
                                      NS
                                (assumed 0.365)
                                      NS
                                  (assumed 1)
                                      NS
                                (assumed 0.365)
                                      NS
                 Drench application, Altus, FDF Ready to use
                                  Nursery[1]
                                     0.14
                                    (0.16)
                                      NS
                                  (assumed 2)
                                     0.365
                                    (0.409)
                                       7
                                Foliar, Altus
                              Stone Fruits C12-12
                                     0.18
                                    (0.20)
                                      NS
                                 (assumed 2)
                                     0.365
                                    (0.409)
                                      10
                                 Aerial, Altus

                                     0.18
                                    (0.20)
                                      NS
                                  (assumed 2)
                                     0.365
                                    (0.409)
                                       7
                                Foliar, Sivanto
                               Caneberry 13-07 A
                                     0.18
                                     (020)
                                      NS
                                  (assumed 2)
                                     0.365
                                    (0.409)
                                       7
                                Foliar, Altus

                                     0.122
                                    (0.137)
                                      NS
                                  (assumed 3)
                                     0.365
                                    (0.409)
                                       7
                               Aerial, Sivanto
                                Taro leaves[1]
                                    0.0023
                                   (0.0026)
                                      NS
                                  (assumed 3)
                           NS assumed 0.007 (0.008)
                                      NS
                                 Foliar, Altus

                                     0.122
                                    (0.137)
                                      3
                                     0.365
                                    (0.409)
                                       7
                               Foliar, Sivanto
                                 Turnip greens
                                    0.0044
                                   (0.0049)
                                       1
                                    0.0044
                                      NA
                                 Foliar, Altus

                                     0.122
                                    (0.137)
                                    3 crops
                                     0.365
                                    (0.409)
                                       7
                                Aerial, Sivanto
                                    Avocado
                                     0.18
                                    (0.20)
                                      NS
                                  (assumed 2)
                                     0.365
                                    (0.409)
                                      14
                                Foliar, Sivanto
                                     Sataw
                                     0.18
                                    (0.20)
                                      NS
                                  (assumed 2)
                                     0.365
                                    (0.409)
                                      14
                                Foliar, Sivanto
                                     Pequi
                                     0.18
                                    (0.20)
                                      NS
                                  (assumed 2)
                                     0.365
                                    (0.409)
                                      14
                               Foliar , Sivanto
                              Tamarind of indies
                                     0.18
                                    (0.20)
                                      NS
                                  (assumed 2)
                                     0.365
                                    (0.409)
                                      14
                               Foliar, Sivanto
                                     Abiu
                                     0.18
                                    (0.20)
                                      NS
                                  (assumed 2)
                                     0.365
                                    (0.409)
                                      14
                                Foliar, Sivanto
                                  Pomegranate
                                     0.18
                                    (0.20)
                                      NS
                                  (assumed 2)
                                     0.365
                                    (0.409)
                                       7
                                Foliar, Sivanto

                                     0.18
                                    (0.20)
                                      NS
                                  (assumed 2)
                                     0.365
                                    (0.409)
                                      14
                                 Foliar, Altus
                                   Persimmon
                                     0.18
                                    (0.20)
                                      NS
                                  (assumed 2)
                                     0.365
                                    (0.409)
                                       7
                               Foliar, Sivanto

                                     0.18
                                    (0.20)
                                      NS
                                  (assumed 2)
                                     0.365
                                    (0.409)
                                      14
                                 Foliar, Altus
                                    Papaya
                                     0.18
                                    (0.20)
                                      NS
                                  (assumed 2)
                                     0.365
                                    (0.409)
                                       7
                               Foliar, Sivanto
                                    Mabolo
                                     0.18
                                    (0.20)
                                      NS
                                  (assumed 2)
                                     0.365
                                    (0.409)
                                      14
                               Foliar, Sivanto
                                     Mango
                                     0.18
                                    (0.20)
                                      NS
                                  (assumed 2)
                                     0.365
                                    (0.409)
                                      14
                           Foliar, Sivanto and Altus
                                   Canistel
                                     0.18
                                    (0.20)
                                      NS
                                  (assumed 2)
                                     0.365
                                    (0.409)
                                      14
                               Foliar, Sivanto
                                    Etambe
                                     0.18
                                    (0.20)
                                      NS
                                  (assumed 2)
                                     0.365
                                    (0.409)
                                      14
                               Foliar, Sivanto
                                  Kei apple
                                     0.18
                                    (0.20)
                                      NS
                                  (assumed 2)
                                     0.365
                                    (0.409)
                                      14
                               Foliar, Sivanto
                                   Langstat
                                     0.18
                                    (0.20)
                                      NS
                                  (assumed 2)
                                     0.365
                                    (0.409)
                                      14
                               Foliar, Sivanto
                                    Lucuma
                                     0.18
                                    (0.20)
                                      NS
                                  (assumed 2)
                                     0.365
                                    (0.409)
                                      14
                               Foliar, Sivanto
                                    Pawpaw
                                     0.18
                                    (0.20)
                                      NS
                                  (assumed 2)
                                     0.365
                                    (0.409)
                                      14
                               Foliar, Sivanto
                                  Mangosteen
                                     0.18
                                    (0.20)
                                      NS
                                  (assumed 2)
                                     0.365
                                    (0.409)
                                      14
                               Foliar, Sivanto
                                     Paho
                                     0.18
                                    (0.20)
                                      NS
                                  (assumed 2)
                                     0.365
                                    (0.409)
                                      14
                               Foliar, Sivanto
                                   Quandong
                                     0.18
                                    (0.20)
                                      NS
                                  (assumed 2)
                                     0.365
                                    (0.409)
                                      14
                               Foliar, Sivanto
                                  Wild loquat
                                     0.18
                                    (0.20)
                                      NS
                                  (assumed 2)
                                     0.365
                                    (0.409)
                                      14
                               Foliar, Sivanto
                                  Akee apple
                                     0.18
                                    (0.20)
                                      NS
                                  (assumed 2)
                                     0.365
                                    (0.409)
                                      14
                               Foliar, Sivanto
                                   Pelipisan
                                     0.18
                                    (0.20)
                                      NS
                                  (assumed 2)
                                     0.365
                                    (0.409)
                                      14
                               Foliar, Sivanto
                                    Poshte
                                     0.18
                                    (0.20)
                                      NS
                                  (assumed 2)
                                     0.365
                                    (0.409)
                                      14
                               Foliar, Sivanto
                                   Plantain
                                     0.18
                                    (0.20)
                                      NS
                                  (assumed 2)
                                     0.365
                                    (0.409)
                                      14
                          Foliar, Sivanto  and Altus
                                    Banana
                                     0.18
                                    (0.20)
                                      NS
                                  (assumed 2)
                                     0.365
                                    (0.409)
                                      14
                           Foliar, Sivanto and Altus
                                    Sapote
                                     0.18
                                    (0.20)
                                      NS
                                  (assumed 2)
                                     0.365
                                    (0.409)
                                      14
                               Foliar, Sivanto
                                  Screw-pine
                                     0.18
                                    (0.20)
                                      NS
                                  (assumed 2)
                                     0.365
                                    (0.409)
                                      14
                               Foliar, Sivanto
                                  Start apple
                                     0.18
                                    (0.20)
                                      NS
                                  (assumed 2)
                                     0.365
                                    (0.409)
                                      14
                               Foliar, Sivanto
                                    Lanjut
                                     0.18
                                    (0.20)
                                      NS
                                  (assumed 2)
                                     0.365
                                    (0.409)
                                      14
                               Foliar, Sivanto
                                    Jatoba
                                     0.18
                                    (0.20)
                                      NS
                                  (assumed 2)
                                     0.365
                                    (0.409)
                                      14
                               Foliar, Sivanto
                                    Cupuacu
                                     0.18
                                    (0.20)
                                      NS
                                  (assumed 2)
                                     0.365
                                    (0.409)
                                      14
                               Foliar, Sivanto
                                    Bacury
                                     0.18
                                    (0.20)
                                      NS
                                  (assumed 2)
                                     0.365
                                    (0.409)
                                      14
                               Foliar, Sivanto
App=application; MRI=minimum retreatment interval; PHI=preharvest interval; NA=not applicable; NS=not specified on the label; a.i.=active ingredient; A=acre
*Applications limitations were on a single and crop number application basis.  It is possible that the chemical could be applied over multiple crops to one field.
[1]There are uncertainties regarding the application rate on these crops as the label doesn't provide the information

                                  Appendix B
              2014 Drinking Water Assessment of Flupyradifurone

                                  Appendix C
PRZM-GW results when using the maximum application rate on nurseries and stone fruits (0.18 lbs a.i./A x 2 applications for a total of 0.365 lbs a.i./A per year of flupyradifurone).