Document ID: EPA-HQ-OPP-2005-0145-0013
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2006-12-20T05:00Z

Primary Evaluator	

 Douglas A. Dotson, Chemist, RAB2

	

Date:  9/22/2005  

Peer Reviewer	

 William Drew, Chemist, RAB2

	

Date: 10/7/2005 

This DER was originally prepared under contract by Dynamac Corporation
(1910 Sedwick Rd., Building 100, Suite B; Durham, NC 27713; submitted
1/14/2005).  The DER has been reviewed by the HED and revised to reflect
current OPP policies.

STUDY REPORT:

46145101 Chen, H. (2003) BAS 516 (BAS 510 F Plus BAS 500 F): Magnitude
of the Residue on Spinach. Lab Project Number: IR-4 PR No. 08090. 
Unpublished study prepared by IR-4 Project Center for Minor Crop Pest
Management. {OPPTS 860.1500}

EXECUTIVE SUMMARY:

In eight spinach field trials conducted during 2001, boscalid (70% WDG)
was applied using ground equipment as two directed foliar applications
to spinach at commercial maturity, at a retreatment interval (RTI) of
6-8 days.  The application rate was 0.39-0.42 lb ai/A/application, for a
total of 0.78-0.82 lb ai/A/season.  The boscalid was tank mixed with the
last two of four foliar applications of the fungicide pyraclostrobin
(20% WDG); as the pyraclostrobin data from these tests were previously
reviewed (46109101.der), it is not included in this report.  A single
control (designated 0-DAT (days after treatment)) and duplicate treated
samples of spinach leaves were collected from each test at commercial
maturity the same day as the last treatment (0-DAT), 6-7 DAT, and 13-15
DAT.  Samples were stored frozen from collection to analysis for
3.2-11.3 months, an interval supported by available stability data.

The LC/MS/MS method (BASF Method Number D9908) used to determine
residues of boscalid in/on spinach leaves is adequate for data
collection.  For this method, residues are extracted with
methanol:water:2 N HCl, concentrated, cleaned up by solvent partitioning
and silica gel SPE, and analyzed by LC/MS/MS.  The lowest limit of
method validation (LLMV) was 0.05 ppm.  Based on recovery data at the
LLMV, the LOQ and LOD were calculated to be 0.06 and 0.02 ppm,
respectively.

Residues of boscalid were 12.6-41.8 ppm in/on 16 spinach leaf samples
harvested immediately following (0-DAT) the last of two foliar
applications.  Boscalid residues were 4.5-21.3 ppm in/on 16 spinach leaf
samples harvested 6-7 DAT and 0.17-17.8 ppm in/on 16 spinach leaf
samples harvested 13-15 DAT.  Average boscalid residues were 24.9 ppm
(HAFT = 39.5 ppm) from 0 DAT samples, 10.4 ppm (HAFT = 21.0 ppm) from 7
DAT samples, and 6.4 ppm (HAFT = 17.1 ppm) from 14 DAT samples.

STUDY/WAIVER ACCEPTABILITY/DEFICIENCIES/CLARIFICATIONS:

Under the conditions and parameters used in the study, the spinach field
trial residue data are classified as scientifically acceptable.  The
acceptability of this study for regulatory purposes is addressed in the
forthcoming U.S. EPA  Residue Chemistry Summary Document (D322235).

COMPLIANCE:

Signed and dated GLP, quality assurance, and data confidentiality
statements were provided.  No deviations from regulatory requirements
were noted that would impact the study results or their interpretation.

A.	BACKGROUND INFORMATION

Boscalid is an anilide fungicide that inhibits mitochondrial
respiration, thereby inhibiting spore germination, germ tube elongation,
mycelial growth, and sporulation of pathogenic fungi on the leaf
surface.  Permanent tolerances have been established in 40 CFR §180.589
for residues of boscalid in/on numerous plant, animal, and rotational
crop commodities, ranging from 0.02 ppm in/on eggs to 35 ppm in/on dried
hops.  Tolerances have been established for two of the representative
commodities of the leafy vegetables crop group:  head lettuce at 6.5 ppm
and leaf lettuce at 11.0 ppm. The current field trials were submitted by
IR-4 to support the use of boscalid on spinach.  The proposed use rate
cited in the study was for two broadcast foliar applications of boscalid
(70% WDG) at 0.4 lb ai/A/application for a total of 0.8 lb ai/A/season,
with a RTI of 7 days and a 0-Day PHI.  The nomenclature and
physicochemical properties of boscalid are presented below in Tables
A.1. and A.2.

TABLE A.1.	Nomenclature of Boscalid

Compound	

Common name	

Boscalid

Company experimental names	

BAS 510 F

IUPAC name	

2-chloro-N-(4'-chlorobiphenyl-2-yl)-nicotinamide

CAS name	

3-pyridinecorboxamide,2-chloro-N-(4'-chloro[1,1'-biphenyl]-2-yl

CAS #	

188425-85-6

End-use products/EP	

70% WDG (Endura( fungicide; EPA Reg. No. 7969-197)



TABLE A.2.  Physicochemical Properties for Boscalid (BAS 510 F)

Parameter	

Value	

Reference

Melting point	

143.4-143.6(C  (TGAI)	

D278385, M. Nelson, 8/15/03

 

pH (23(C)	

5.5 (1% solution)

	

Density	

1.394g/cm3 (TGAI)

	

Water solubility ( 20(C)	

4.64 mg/L (PAI)

	

Solvent solubility (g/100 mL at 20(C)	

PAI:  16-20 in acetone; 4-5 in acetonitrile; 4-5 in methanol; 6.7-8 in
ethylacetate; 20-25 in  dichloromethane; 2-2.5 in toluene; <1 in
1-octanol

	

Vapour pressure at 20(C	

7 x 10-9 hPa (PAI)

	

Dissociation constant (pKa)	

Does not dissociate in water.

	

Octanol/water partition coefficient at 21(C  Log(KOW)	

2.96 (PAI)

	

UV/visible absorption spectrum	

Not available

	   TGAI:  technical grade active ingredient

   PAI: pure active ingredient

B.	EXPERIMENTAL DESIGN

B.1.	Study Site Information

TABLE B.1.1	Trial Site Conditions.

Trial Identification 

(City, State, Year)	

Soil characteristics	

Meteorological data1

	

Type	

%OM	

pH	

CEC	

Overall total monthly rainfall range (inches)	

Overall average monthly temperature range ((C)

Freeville, NY, 2001	

Silty Clay Loam	

NA = Not Applicable	

Not reported = NR	

NR

Salisbury, MD, 2001	

Loamy Sand	

NA	

NR	

NR

Salisbury, MD, 2001	

Loamy Sand	

NA	

NR	

NR

Weslaco, TX, 2001	

Sandy Loam	

NA	

NR	

NR

Holtville, CA, 2001	

Silty Clay Loam	

NA	

NR	

NR

Salinas, CA, 2001	

Loam	

NA	

NR	

NR

Fort Collins, CO, 2001	

Clay/Clay Loam	

NA	

NR	

NR

Weslaco, TX, 2001	

Sandy Clay	

NA	

NR	

NR

1	Detailed meteorological data were not provided.

Weather conditions were reported to be normal; no further details were
provided.  No unusual conditions that would affect the integrity of the
study were reported.  Rainfall was supplemented with irrigation as
needed. 

In eight spinach field trials conducted during 2001, boscalid (70% WDG)
was applied to spinach plants using ground equipment as two directed
foliar applications (Table B.1.2) at commercial maturity.  The
applications were made when plants were at the 5-8 leaf stage and the
RTI was 6-8 days.  The application rate was 0.39-0.42 lb
ai/A/application, for a total of 0.78-0.82 lb ai/A/season. 

Each field test also included applications of the fungicide
pyraclostrobin (BAS 500 F; 20% WDG) as four broadcast foliar
applications at ~0.2 lb ai/A for a total of 0.8 lb ai/A/season, at  RTIs
of ~7 days.  The final two pyraclostrobin applications were tank mixed
with the two boscalid applications.  Residue data for pyraclostrobin and
its regulated metabolite were included in the submission; however, these
data are not included in this report as the data were previously
reviewed (46109101.der, M. Xue, 7/22/04).

TABLE B.1.2.  Study Use Pattern on Spinach.

Location (City, State), Year	

EP 1	

Method 2; Timing	

Volume (gal/A)	

Single Rate

(lb ai/A) 3 	

No. of Appl.	

RTI (days)	

Total Rate

(lb ai/A) 3	

Tank Mix Adjuvants

Freeville, NY, 2001	

70% WDG	

Foliar directed; 5-12 leaf stage 	

40-42	

0.40, 0.42	

2	

6	

0.82	

None

Salisbury, MD, 2001	

70% WDG	

Foliar directed; mature spinach	

33	

0.40	

2	

8	

0.80	

None

Salisbury, MD, 2001	

70% WDG	

Foliar directed; mature spinach	

33-34	

0.40, 0.41	

2	

8	

0.81	

None

Weslaco, TX, 2001	

70% WDG	

Foliar directed; 12-16 leaf stage	

39	

0.39	

2	

7	

0.78	

None

Holtville, CA, 2001	

70% WDG	

Foliar directed; mature spinach	

39-41	

0.39, 0.40	

2	

7	

0.79	

None

Salinas, CA, 2001	

70% WDG	

Foliar directed; vegetative/mature	

62-75	

0.40, 0.41	

2	

7	

0.81	

None

Fort Collins, CO, 2001	

70% WDG	

Foliar directed; vegetative stage	

40	

0.40	

2	

8	

0.80	

None

Weslaco, TX, 2001	

70% WDG	

Foliar directed; vegetative stage	

42-44	

0.40-0.41	

2	

7	

0.81	

None

1	EP = End-use Product.

2	The applications were made using ground equipment.  

3	The Endura( 70% WDG label rate for lettuce is 0.48 lb ai/A/application
and 0.96 lb ai/A/season.  The target rate for the spinach field trials
was 0.40 lb ai/A/application and 0.80 lb ai/A/season. 

TABLE B.1.3.	Trial Numbers and Geographical Locations.

NAFTA Growing Region 1	

 Spinach

	

Submitted	

Requested

Canada	

US

1	

1	

NA	

1

2	

2	

NA	

2

3	

--	

NA	

--

4	

--	

NA	

--

5	

--	

NA	

--

6	

2	

NA	

2

7	

--	

NA	

--

8	

1	

NA	

--

9	

--	

NA	

1

10	

2	

NA	

2

11	

--	

NA	

--

12	

--	

NA	

--

13	

--	

NA	

--

Total	

8	

NA	

8

1	Regions 14-21 and 1A, 5A, 5B, and 7A were not included as the proposed
use is for the US only.

NA = not applicable.

B.2.	Sample Handling and Preparation

Spinach was harvested at commercial maturity, the same day as the last
application (0-DAT), 6-7 DAT, and 13-15 DAT from all tests.  A single
control (0 DAT only) and duplicate treated spinach leaf samples (3-5 lbs
each) were collected from each test and placed in frozen storage at the
test facility within 40 minutes.  Samples were stored frozen for 1-44
days, then shipped frozen by ACDS freezer truck, FedEx, or Airborne
Express to the analytical laboratory, BASF Agro Research, RTP, NC, and
stored frozen (<-10( C) prior to analysis.  Samples were stored frozen
from collection to analysis for up to 11.3 months.

B.3.	Analytical Methodology

Residues of boscalid were determined using an LC/MS/MS method (BASF
Method Number D9908).  Method D9908 was validated in conjunction with a
previous boscalid petition (DP Barcode D278385, M. Nelson, 8/15/03) and
deemed acceptable for data collection.  A brief description of the
method follows.

Residues are extracted with methanol:water:2 N HCl (70:25:5, v/v/v),
concentrated, and cleaned up by partitioning into cyclohexane.  Residues
are then concentrated, cleaned up using a silica gel solid phase
extraction cartridge eluted with 4% ethyl acetate in methylene chloride.
 Residues are analyzed by LC/MS/MS using the positive ionization mode
monitoring ion transitions from m/z 343 to 307.  Quantitation is
obtained using an external calibration curve of boscalid.  The LLMV for
boscalid residues is 0.05 ppm in/on spinach.  The LOQ and LOD were
determined to be 0.06 ppm and 0.02 ppm, respectively.

In conjunction with the current field trials, control samples of spinach
were fortified with boscalid at 0.05, 1.0, and 50 ppm and analyzed
concurrently with the field samples.

C.	RESULTS AND DISCUSSION

The number and geographic representation of the spinach field trials are
adequate.  Eight field trials were conducted in Regions 1, 2 (two
tests), 6 (two tests), 8, and 10 (two tests). 

The LC/MS/MS method (BASF Method Number D9908) used to determine
residues of boscalid in/on spinach leaves is adequate for data
collection.  Average concurrent recoveries were 84 ± 10% for boscalid
(Table C.1).  Apparent residues of boscalid were <LOQ in/on all control
samples.  Based on the LLMV, the LOQ was estimated to be 0.06 ppm for
residues of boscalid in/on spinach; the LOD was estimated to be 0.02
ppm.  Adequate sample calculations and chromatograms were provided.

Samples were stored frozen from collection to analysis for 3.2-11.3
months (Table C.2).  Storage stability data are available on
representative plant commodities indicating that boscalid is stable in
frozen storage for at least 12 months (D278385, M. Nelson, 8/15/03). 
These data will support the current spinach field trials.

TABLE C.1	Summary of Concurrent Recoveries of Boscalid from Spinach
using LC/MS/MS Method D9908.

Analyte	

Spinach Matrix	

Spiking Level

(mg/kg)	

Sample size	

Recoveries (%)	

Mean Recovery ± SD

Boscalid

(BAS 510 F)	

Leaves	

0.05	

8	

68-105 (1)1	

84 ± 10

1.0	

2	

85, 97

	

50.0	

6	

75-89

	1	The number of recoveries outside the 70-120% range is in parentheses.

TABLE C.2	Summary of Freezer Storage Conditions

Spinach Matrix	

Storage Temp. ((C)	

Actual Storage Duration (months) 1		

Limit of Demonstrated Storage Stability (months) 2

Leaves	

< -10	

3.2-11.3	

12

1	Extracts were stored frozen for 0-1 days prior to analysis.

2	Storage stability data are available indicating that boscalid is
stable in frozen plant commodities for at least 12 months (D278385, M.
Nelson, 8/15/03).

Residues of boscalid were 12.6-41.8 ppm in/on 16 spinach leaf samples
harvested immediately following (0-DAT) the last of two foliar
applications of the 70% WDG totaling 0.78-0.82 lb/A/season (Table C.3). 
Boscalid residues were 4.5-21.3 ppm in/on 16 spinach leaf samples
harvested 6-7 DAT and 0.17-17.8 ppm in/on 16 spinach leaf samples
harvested 13-15 DAT.  Average boscalid residues were 24.9 ppm (HAFT =
39.5 ppm) from 0 DAT samples, 10.4 ppm (HAFT = 21.0 ppm) from 7 DAT
samples, and 6.4 ppm (HAFT = 17.1 ppm) from 14 DAT samples (Table C.4).

Common cultural practices were used to maintain plants, and the weather
conditions and the maintenance chemicals and fertilizer used in the
study did not have a notable impact on the residue data.  In addition,
the application volume has minimal or no impact on residue levels.



TABLE C.3	Residue Data from Spinach Field Trials with 70% WDG
Formulation of Boscalid.

Trial ID 

(City, State, Year)	

EPA

Region	

Spinach Variety	

Matrix	

Total Rate

(lb ai/A)	

PHI (days) 1	

Boscalid Residues (ppm)

Freeville, NY, 2001	

1	

Olympia	

Leaves	

0.82	

0	

25.9, 27.5

	

6	

4.54, 4.95

	

14	

0.18, 0.17

Salisbury, MD, 2001	

2	

Vienna	

Leaves	

0.80	

0	

22.8, 21.9

	

7	

17.6, 21.3

	

14	

16.4, 17.8

Salisbury, MD, 2001	

2	

Vancouver	

Leaves	

0.81	

0	

28.7, 28.2

	

7	

20.9, 21.0

	

14	

14.7, 14.5

Weslaco, TX, 2001	

6	

Olympia	

Leaves	

0.78	

0	

41.6, 34.0

	

7	

9.12, 9.34

	

15	

4.21, 3.75

Holtville, CA, 2001	

10	

Bolero	

Leaves	

0.79	

0	

13.0, 12.6

	

7	

10.2, 8.90

	

14	

5.12, 5.68

Salinas, CA, 2001	

10	

El Palmar	

Leaves	

0.81	

0	

14.3, 16.3

	

6	

7.66, 5.40

	

13	

3.68, 3.08

Fort Collins, CO, 2001	

8	

Unipack 151	

Leaves	

0.80	

0	

17.9, 14.7

	

7	

4.91, 4.49

	

14	

1.05, 2.20

Weslaco, TX, 2001	

6	

Fall Green	

Leaves	

0.81	

0	

37.2, 41.8

	

6	

9.10, 6.65

	

13	

4.76, 4.53

1	The current PHI for lettuce is 14 days; the proposed PHI for spinach
is 0 days.

TABLE C.4.	Summary of Residue Data for Spinach from Crop Field Trials
using a 70% WDG Formulation of Boscalid.

Commodity	

Total Rate

(lb a.i./A) 	

PHI (days) 1	

Boscalid Residue Levels (ppm)

	

n	

Min.	

Max.	

HAFT 2	

Median (STMdR3)	

Mean (STMR3)	

Std. Dev.

Spinach Leaves	

0.78-0.82	

0	

16	

12.6	

41.8	

39.5	

24.4	

24.9	

9.9

6-7	

16	

4.49	

21.3	

21.0	

9.0	

10.4	

6.2

13-15	

16	

0.17	

17.8	

17.1	

4.37	

6.36	

5.93

1	The current PHI for lettuce is 14 days; the proposed PHI for spinach
is 0 days.

2 	HAFT = Highest Average Field Trial. 

3	STMdR = Supervised Trial Median Residue; STMR = Supervised Trial Mean
Residue.

D.	CONCLUSION

The spinach field trial data are adequate and reflect the use of up to
two foliar directed applications of boscalid (70% WDG) at 0.4 lb
ai/A/application, for a total of ~0.80 lb ai/A/season.  The data would
support a 0-day, 7-day, or 14-day PHI.  Maximum boscalid residues were
41.8 ppm from 0-day PHI samples, 21.3 ppm from 7-day PHI samples, and
17.8 ppm from 14-day PHI samples.

E.	REFERENCES

PP#0F06313.  BAS 510 F (Common Name: Boscalid), New Fungicide Active
Ingredient. Residue Chemistry Summary Document, D278385, M. Nelson,
8/15/03

F.	DOCUMENT TRACKING

Petition Number: 1F6313

DP Barcode: D316092

PC Code: 128008

Boscalid/7969-197/PC Code 128008/BASF Corporation/7969

DACO 7.4.1/OPPTS 860.1500/OECD IIA 6.3.1, 6.3.2, 6.3.3 and IIIA 8.3.1,
8.3.2, 8.3.3

Crop Field Trial - Spinach

((((( PAGE  1 ((((( NUMPAGES  8 

DP Barcode D316092/MRID No. 46145101