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

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

                                                                      OFFICE OF
                                                            CHEMICAL SAFETY AND
                            		POLLUTION PREVENTION
MEMORANDUM

Date:		24-MAR-2011

Subject:	Saflufenacil in/on Vegetable, Legume, Subgroup 6C, pea and bean (except soybean); Soybean; Rapeseed Subgroup 20A; Sunflower Subgroup 20B; and Cottonseed Subgroup 20C.  Summary of Analytical Chemistry and Residue Data.

PC Code:  118203
DP Barcodes:  D381129, D381977
Decision Nos.:  436793, 437943
Registration No.:  7969-278
Petition Nos.:  0F7744, 0F7766
Regulatory Action:  Sec. 3 Registration
Risk Assessment Type:  NA
Case No.:  NA
TXR No.:  NA
CAS No.:  372137-35-4
MRID Nos.:  480809-01 thru -06, 48135201, 48135202
40 CFR:  §180.649

From:		George F. Kramer, Ph.D., Senior Chemist
		Sarah J. Levy, Chemist
		Risk Assessment Branch 1 (RAB1)
		Health Effects Division (HED) (7509P)

Through:		Dana M. Vogel, Branch Chief
		RAB1/HED (7509P)

To:	       Kathryn Montague/Susan Stanton, PM Team 23
    Registration Division (RD; 7505P)

Executive Summary

Saflufenacil (BAS 800 H) is a broad-spectrum herbicide developed by BASF.  It belongs to the herbicide mode-of-action Group 14 (cell membrane disruptors).  Saflufenacil acts through the inhibition of protoporphyrinogen oxidase (PPO), resulting in cell membrane damage and subsequent plant death.  Sharpen[(TM)] Powered by Kixor Herbicide (EPA Reg. No. 7969-278), a 2.85 lb ai/gal suspension-concentrate (SC) formulation, is currently registered for use on legume vegetables (Crop Group 06), the foliage of legume vegetables (Crop Group 07), cereal grains (Crop Group 15), the forage, fodder, and straw of cereal grains (Crop Group 16), cotton, and sunflower.

BASF has submitted a proposal to amend the established tolerances for saflufenacil on cotton, dry bean, dry pea, and soybean (PP#0F7744).  The amended tolerances on these crops are the result of the proposed harvest aid/desiccation use pattern for Sharpen[(TM)] Powered by Kixor Herbicide (EPA Reg. No. 7969-278); the currently-registered uses are for preplant application.  In addition, BASF has submitted a proposal for a new use of Sharpen[(TM)] on rapeseed subgroup 20A as harvest aid/desiccant (PP#0F7744).

Sharpen[(TM)] is proposed for up to 2 foliar spray applications with a total maximum application rate of 0.045 lb ai/A as a harvest aid.  Applications may be made using ground or aerial equipment, and use of an adjuvant is required.  Preharvest intervals (PHIs) of 2-5 days are proposed.

Concurrently, BASF has petitioned for the establishment of permanent tolerances for "saflufenacil, including its metabolites and degradates, in or on the commodities in the table below.  Compliance with the tolerance levels specified below is to be determined by measuring only the sum of saflufenacil, 2-chloro-5-[3,6-dihydro-3-methyl-2,6-dioxo-4-(trifluoromethyl)-1(2H)-pyrimidinyl]-4-fluoro-N-[[methyl(1-methylethyl)amino]sulfonyl]benzamide, and its metabolites N-[2-chloro-5-(2,6-dioxo-4-(trifluoromethyl)-3,6-dihydro-1(2H)-pyrimidinyl)-4-fluorobenzoyl]-N'-isopropylsulfamide and N-[4-chloro-2-fluoro-5-({[(isopropylamino)sulfonyl]amino}carbonyl)phenyl]urea, calculated as the stoichiometric equivalent of saflufenacil" in/on the following raw agricultural commodities (RACs):

                                   PP#0F7744
Oilseeds, Cottonseed Subgroup 20C, gin byproducts
                                    3.5 ppm
Oilseeds, Cottonseed Subgroup 20C, undelinted seed
                                    0.2 ppm
Oilseeds, Sunflower Subgroup 20B, seed
                                    1.0 ppm
Pea, vines
                                    8.0 ppm
Soybean, aspirated grain fractions
                                   4.52 ppm
Soybean, hulls
                                   0.42 ppm
Soybean, seed
                                    0.1 ppm
Vegetable, Legume, Subgroup 6C, beans, dry
                                    0.5 ppm
Vegetable, Legume, Subgroup 6C, peas, dry
                                    0.1 ppm
                                   PP#0F7766
Oilseeds, Rapeseed Subgroup 20A, seed
                                    0.8 ppm

The nature of the residue in plants, rotational crops, and livestock is adequately understood based on acceptable metabolism studies conducted on corn (preplant application), soybean (preplant and preharvest application), tomato (preplant application), rotational crops, lactating goats, and laying hens.

In plants, the main reactions involved in the metabolic pathway of saflufenacil are N-demethylation at the uracil ring, stepwise degradation (N-dealkylation) of the N-methyl-N-isopropyl group, hydrolytic opening of the uracil ring generating a urea side chain, and hydroxylation of the phenyl ring.  M800H11 was found in all corn and soybean matrices from both [14]C-labeled uracil and [14]C-labeled phenyl saflufenacil.  M800H11 is formed when saflufenacil undergoes demethylation at both nitrogen atoms.  M800H35 was detected only after [14]C-labeled phenyl saflufenacil treatment and was detected at higher levels in soybean matrices.  M800H35 is formed when parent saflufenacil undergoes demethylation at the sulfonylurea side chain and opening of the uracil ring.  The HED Residues of Concern Knowledgebase Subcommittee (ROCKS) determined that residues of concern for the tolerance expression and risk assessment consist of saflufenacil, M800H11, and M800H35 (Memo, B. Daiss, 1/6/09; D359645).  An additional major metabolite (M800H02) that is not included in the tolerance expression was observed in soybean seed following post-emergence application.  As the structure of M800H02 is closely related to the parent compound and it is the precursor of the regulated metabolite M800H11, HED concludes that M800H02 is a residue of concern for risk-assessment purposes in seed crops following post-emergence treatment.

The metabolism of saflufenacil in rotational crops appears to be consistent with the pathway observed in the plant metabolism studies.  The residues of concern for rotational crops are saflufenacil, M800H11, and M800H35 (Memo, B. Daiss, 1/6/09; D359645).  Unless the petitioner requests plantback intervals (PBIs) shorter than 4 months, no additional data are required, and tolerances for inadvertent residues in/on rotational crops need not be established in conjunction with the proposed uses.

In livestock, saflufenacil was metabolized by several dealkylation steps occurring at two different sites in the molecule (N-isopropyl-N-methylsulfamide side chain and at the uracil ring) and via hydrolytic opening of the uracil ring (goat only).  In the ruminant metabolism study, saflufenacil was a major residue in all matrices.  M800H04, a ring opening product, was the only significant metabolite found (liver).  In the poultry metabolism study, saflufenacil was a major residue in all matrices and no significant metabolites were found.  The HED ROCKS determined that saflufenacil per se is the only residue of concern in livestock for the tolerance expression and risk assessment (Memo, B. Daiss, 1/6/09; D359645).

The petitioner has submitted two liquid chromatography/mass spectroscopy/mass spectroscopy (LC-MS/MS) analytical methods for the determination of residues of the parent and its metabolites in/on plant and livestock commodities.  BASF Method D0603/02 was developed for determination of residues of saflufenacil and its metabolites M800H11 and M800H35 in different plant matrices using LC-MS/MS.  The limit of quantitation (LOQ) was 0.01 ppm for each analyte in food matrices (human consumption) and 0.025 ppm for each analyte in feed matrices (livestock consumption).  BASF analytical Method No. L0073/01 was developed for determination of saflufenacil in livestock matrices using LC-MS/MS.  The LOQ was 0.01 ppm in all matrices.  These methods were used as the data-collection methods in the analysis of samples for residues of concern from the various studies associated with the current petition.  Each method has been adequately validated by the petitioner as well as by independent laboratories.  Method No. L0073/01 was also adequately radiovalidated using weathered samples obtained from metabolism studies.

HED has determined that Methods D0603/02 and L0073/01 are suitable enforcement methods for plant and livestock commodities, respectively, as defined in Standard Operating Procedure (SOP) No. ACB-019 (9/15/08).

The submitted magnitude of the residue data for the raw and processed commodities of cotton, dry bean, dry pea, canola, and soybean are adequate.  There are also adequate storage stability data to validate the storage conditions and intervals of samples collected from the field and processing trials.  With the exception of soybean hulls and aspirated grain fractions (AGFs), no concentration of the total saflufenacil residue was found in any processed commodity, separate tolerances for residues in/on processed commodities are not required.

An adequate dairy cow feeding study has been submitted; this study is acceptable for determining tolerance levels for ruminant commodities.  The increased reasonably-balanced dietary burdens (RBDBs) resulting from the proposed uses necessitate that the established tolerances be increased to 2.5 ppm for residues in liver and 0.05 ppm for residues in meat byproducts except liver of cattle, goats, horses, and sheep.

Regulatory Recommendations and Residue Chemistry Deficiencies

Pending submission of a revised Section F (see requirements under Proposed Tolerances), and the submission of reference standards for the saflufenacil metabolites (see requirements under Submittal of Analytical Reference Standards); there are no residue chemistry issues that would preclude granting an unconditional registration for the use of saflufenacil on the requested crops.

The proposed uses and the submitted data support:  "Tolerances are established for residues of saflufenacil, including its metabolites and degradates, in or on the commodities in the table below.  Compliance with the tolerance levels specified below is to be determined by measuring only the sum of saflufenacil (2-chloro-5-[3,6-dihydro-3-methyl-2,6-dioxo-4-(trifluoromethyl)-1(2H)-pyrimidinyl]-4-fluoro-N-[[methyl(1-methylethyl)amino]sulfonyl]benzamide) and its metabolites N-[2-chloro-5-(2,6-dioxo-4-(trifluoromethyl)-3,6-dihydro-1(2H)-pyrimidinyl)-4-fluorobenzoyl]-N'-isopropylsulfamide and N-[4-chloro-2-fluoro-5-({[(isopropylamino)sulfonyl]amino}carbonyl)phenyl]urea, calculated as the stoichiometric equivalent of saflufenacil, in or on the commodities."

Cotton, gin byproducts
0.45 ppm
Cottonseed Subgroup 20C
0.20 ppm
Sunflower Subgroup 20B
1.0 ppm
Pea, hay
17 ppm
Grain, aspirated fractions
10 ppm
Soybean, hulls
0.50 ppm
Soybean, seed
0.10 ppm
Pea and bean, dried shelled, except soybean, subgroup 6C
0.30 ppm
Rapeseed Subgroup 20A
0.45 ppm

Note to RD:  In conjunction with establishing these tolerances, the existing tolerance for "Vegetable, foliage of legume, group 7" should be modified to "Vegetable, foliage of legume, group 7 (except pea hay)"; the existing tolerance for "Vegetable, legume, group 6" should be replaced with "Vegetable, legume, edible podded, subgroup 6A" plus "Pea and bean, succulent shelled, subgroup 6B"; and the existing tolerances for "Sunflower, seed" and "Cotton, undelinted seed" should be deleted.

The proposed uses and the submitted data also support:  "Tolerances are established for residues of saflufenacil, including its metabolites and degradates, in or on the commodities in the table below.  Compliance with the tolerance levels specified below is to be determined by measuring only saflufenacil, 2-chloro-5-[3,6-dihydro-3-methyl-2,6-dioxo-4-(trifluoromethyl)-1(2H)-pyrimidinyl]-4-fluoro-N-[[methyl(1-methylethyl)amino]sulfonyl]benzamide, in or on the commodities."

Cattle, liver
2.5 ppm
Cattle, meat byproducts, except liver
0.05 ppm
Goat, liver
2.5 ppm
Goat, meat byproducts, except liver
0.05 ppm
Sheep, liver
2.5 ppm
Sheep, meat byproducts, except liver
0.05 ppm
Horse, liver
2.5 ppm
Horse, meat byproducts, except liver
0.05 ppm

860.1650 Submittal of Analytical Reference Standards

   * Analytical standards of saflufenacil, M800H11, and M800H35 are currently available in the National Pesticide Standards Repository [source:  personal communication with T. Cole of Analytical Chemistry Laboratory/Biological and Economics Analysis Division (ACL/BEAD), 10/28/10].  However, since the standards for M800H11 and M800H35 expired on 10/1/10, the petitioner is requested to provide an updated Certificate of Analysis (COA) or a new supply to the Repository.

860.1550 Proposed Tolerances

   * The petitioner is requested to submit a revised Section F specifying the revised tolerance levels and commodity definitions are presented in Table 22 (summarized above).

A human-health risk assessment is forthcoming in a separate document (DP# 380636).

Background

Saflufenacil is a broad-spectrum herbicide developed by BASF.  It belongs to the herbicide mode-of-action Group 14 (cell membrane disruptors).  Saflufenacil acts through the inhibition of PPO, resulting in cell membrane damage and subsequent plant death.  Susceptible weeds develop symptoms within hours of application under active growing conditions.  Plant death occurs within 3-5 days depending upon growing conditions.  The chemical structure and nomenclature of saflufenacil and its metabolites M800H11 and M800H35, and the physicochemical properties of the technical grade of saflufenacil, are presented in Tables 1 and 2.

Table 1.  Saflufenacil and Metabolite Nomenclature.
Chemical Structure

Common name
Saflufenacil
Company experimental name
BAS 800 H (synonyms:  AC 433 379, BASF Reg. No. 4054449)
IUPAC name
N'-[2-Chloro-4-fluoro-5-(3-methyl-2,6-dioxo-4-(trifluoromethyl)-3,6-dihydro-1(2H)-pyrimidinyl)benzoyl]-N-isopropyl-N-methylsulfamide
CAS name
2-Chloro-5-[3,6-dihydro-3-methyl-2,6-dioxo-4-(trifluoromethyl)-1(2H)-pyrimidinyl]-4-fluoro-N-[[methyl(1-methylethyl)amino]sulfonyl]benzamide
CAS registry number
372137-35-4
End-use product (EP)
Sharpen[(TM)] Powered by Kixor Herbicide (EPA Reg. No. 7969-278) (2.85 lb ai/gal SC formulation)
Chemical Structure

Common name
M800H11
Chemical name
N-[2-Chloro-5-(2,6-dioxo-4-(trifluoromethyl)-3,6-dihydro-1(2H)-pyrimidinyl)-4-fluorobenzoyl]-N'-isopropylsulfamide
Chemical Structure

Common name
M800H35
Chemical name
N-[4-Chloro-2-fluoro-5-({[(isopropylamino)sulfonyl]amino}carbonyl)phenyl]urea

Table 2.  Physicochemical Properties of Technical Grade Saflufenacil.
Parameter
Value
Melting point
Average = 189.9 °C, peak max = 193.4 °C
pH
4.43 of 1% solution at 25 °C
Bulk Density (ambient temp.)
0.661 kg/L (free fall), 0.736 kg/L (packed)
Water solubility (20°C)
in g/100-mL:
0.0025 in water (pH = 5); 0.0014 in pH 4 buffer; 0.21 in pH 7 buffer; not determined due to degradation in pH 9 buffer
Solvent solubility (20°C)
in g/100-mL:
19.4 acetonitrile; 24.4 dichloromethane; 55.4 N,N-dimethylformamide; 27.5 acetone; 6.55 ethyl acetate; 36.2 tetrahydrofuran; 35.0 butyrolactone; 2.98 methanol; 0.25 isopropyl alcohol;
0.23 toluene; <0.01 1-octanol; <0.005 n-heptane
Vapor pressure at 20/25°C
20° C = 4.5 x 10-15 Pa
25° C = 2.0 x 10-15 Pa
Dissociation constant (pKa)
4.41
Octanol/water partition coefficient
Mean Log Pow = 2.6 (Pow = 368.3)
UV/visible absorption spectrum
wavelength maximum:  λmax = 271.6 nm
extinction coefficient:  ε = 9709 L/mol-cm
Reference:  BASF Registration Document Number (DocID) 2005/1026464.

860.1200 Directions for Use

BASF has submitted draft labels dated 6/24/10 for the 2.85 lb ai/gal SC formulation (Sharpen[(TM)] Powered by Kixor Herbicide (EPA Reg. No. 7969-278).  Information pertaining to the proposed end-use product is listed in Table 3.  A summary of the proposed use patterns on legume vegetables and oilseeds is detailed in Table 4.

Table 3.  Summary of Proposed End-Use Products.
Trade Name
                                   Reg. No.
                             ai (% of formulation)
                               Formulation Type
                                 Target Crops
                                 Target Pests
                                  Label Date
Sharpen[(TM)] Powered by Kixor Herbicide
                                   7969-278
                                     29.74
                                      SC
                          legume vegetables, oilseeds
                                Broadleaf weeds
                        Draft labels submitted 6/24/10

Table 4.  Summary of Directions for Use of Saflufenacil.
                       Applic. Timing, Type, and Equip.
                                  Formulation
                                [EPA Reg. No.]
                                   App. ate
                                 (lb ai/acre)
                           Max. No. App. per Season
                            Max. Seasonal App. Rate
                                 (lb ai/acre)
                                      PHI
                                    (days)
                        Use Directions and Limitations
                        Oilseeds, Rapeseed Subgroup 20A
                                  Preharvest
                                 Desiccation
                                  Broadcast,
                               Ground or aerial
                                 Sharpen[(TM)]
                                   Herbicide
                                2.85 lb/gal SC
                                  [7969-278]
                                 0.0225-0.045
                                       2
                                     0.045
                                       3
Applications are to be made in >=10 gal/acre (ground) or >=3 gal/acre (aerial).
                       Oilseeds, Sunflower Subgroup 20B
                                  Preharvest
                                 Desiccation
                                  Broadcast,
                               Ground or aerial
                                 Sharpen[(TM)]
                                   Herbicide
                                2.85 lb/gal SC
                                  [7969-278]
                                 0.0225-0.045
                                       2
                                     0.090
                                       7
Applications are to be made in >=10 gal/acre (ground) or >=3 gal/acre (aerial).
                       Oilseeds, Cottonseed Subgroup 20C
                                  Preharvest
                                 Desiccation
                                  Broadcast,
                               Ground or aerial
                                 Sharpen[(TM)]
                                   Herbicide
                                2.85 lb/gal SC
                                  [7969-278]
                                 0.0112-0.045
                                       2
                                     0.045
                                       5
Applications are to be made in >=10 gal/acre (ground) or >=5 gal/acre (aerial).
Dry Edible Beans (all Phaseolus, Lupinus and Vigna species, broad bean (fava bean), garbanzo bean (chickpea), guar, lablab bean (hyacinth bean), and lentils)
                                  Preharvest
                                 Desiccation
                                  Broadcast,
                               Ground or aerial
                                 Sharpen[(TM)]
                                   Herbicide
                                2.85 lb/gal SC
                                  [7969-278]
                                 0.0225-0.045
                                       2
                                     0.045
                                       2
Applications are to be made in >=10 gal/acre (ground) or >=3 gal/acre (aerial).  Do not graze or feed treated hay or straw to livestock.
Dry Peas (including dry field peas as well as all other Pisum species and pigeon pea)
                                  Preharvest
                                 Desiccation
                                  Broadcast,
                               Ground or aerial
                                 Sharpen[(TM)]
                                   Herbicide
                                2.85 lb/gal SC
                                  [7969-278]
                                 0.0225-0.045
                                       2
                                     0.045
                                       3
Applications are to be made in >=10 gal/acre (ground) or >=3 gal/acre (aerial).  Desiccation-treated pea vines may be grazed or fed to livestock
                                   Soybeans
                                  Preharvest
                                 Desiccation
                                  Broadcast,
                               Ground or aerial
                                 Sharpen[(TM)]
                                   Herbicide
                                2.85 lb/gal SC
                                  [7969-278]
                                 0.0225-0.045
                                       2
                                     0.045
                                       3
Applications are to be made in >=10 gal/acre (ground) or >=3 gal/acre (aerial).  Do not graze or feed treated hay or straw to livestock.
Note:  Thorough spray coverage and a methylated seed oil (MSO) plus ammonium-based adjuvant system is required for optimum desiccation activity.

Table 5.  Rotational Crop PBIs for Saflufenacil (from Master Label, no changes proposed).
Crop
                                 PBI (months)

                         Application rate (lb ai/acre)

                                    0.0225
                                     0.045
                                     0.067
                                     0.089
                                     0.112
                                     0.134
Corn
                                       0
                                       0
                                       0
                                       0
                                       0
                                       0
Corn, sweet
                                      0.5
                                       1
                                       2
                                       3
                                       4
                                       4
Sorghum
                                       0
                                       0
                                       0
                                       0
                                       1
                                       1
Small Grains
                                       0
                                       0
                                       0
                                       0
                                       3
                                       3
Chickpea, Field pea, Edible pea
                                       0
                                       0
                                       3
                                       3
                                       6
                                       6
Lentil
                                       1
                                       2
                                       3
                                       4
                                       6
                                       9
Soybean
                                       1
                                       2
                                       3
                                       4
                                       6
                                       9
Cotton
                                      1.5
                                       3
                                       4
                                       6
                                       6
                                       9
Other Crops
                                       4
                                       5
                                       6
                                       7
                                       8
                                       9

Conclusions:  The submitted use directions for Sharpen[(TM)] Herbicide are adequate to allow evaluation of the residue data relative to the proposed uses.

860.1300 Nature of the Residue - Plants

DER Reference List:	Soybean (48080901.der.doc)

Soybean

The metabolism of saflufenacil was investigated in soybean following a single post-emergent spray of [uracil-4-[14]C]-saflufenacil to soybean plants at BBCH growth stage 87-89 at an application rate of 0.089 lb/A (2X).  Soybean matrices (stem, pod, seed, and leaves) were sampled 7 days after application.  The soybean plants were cultivated in containers in climatic chambers (phytotrons) under simulated conditions for a typical U.S. soybean growing area.  The interval of frozen storage of samples for both labels was supported by the re-extraction and analysis of soybean seed and leaves samples at the end of the analytical phase.

[14]C-Residues in homogenates of soybean stem, pod, seed, and leaves were extracted sequentially three times with methanol (3x) and two times (2x) with water.  The unextractable residues after solvent extraction were subjected to solubilization procedures with 1% aqueous ammonia followed by incubation with macerozyme/cellulase, amylase/amyloglucosidase, tyrosinase/laccase, and HCl (seed only).  The accountabilities, calculated as (total extractable + total unextractable)/(calculated total radioactive residue) x 100, were acceptable ranging from 86-99%.

The radioactivity in extracts was determined by liquid scintillation counting (LSC).  Solid samples were oxidized prior to analysis.  The identity of residues in the purified methanol extracts were confirmed by LC-MS and LC-MS/MS analyses.  Additional metabolites were identified/characterized by co-chromatography and comparison of retention times with the respective radiolabeled reference standards; and by comparison of the metabolite profiles.

The total radioactive residues (TRR) in soybean matrices were determined directly by combustion analyses and indirectly by the sum of the extractable and unextractable [14]C-residues. The TRR were similar using either method of determination.  The TRRs, as determined by direct combustion analyses, were 19.6 ppm (leaves), 1.74 ppm (pod), 0.412 ppm (stem), and 0.049 ppm (seed).  The TRR, determined indirectly by the summation of the extractable and unextractable residues, were 17.9 ppm (leaves), 1.86 ppm (pod), 0.419 ppm (stem), and 0.043 ppm (seed).  All calculations throughout the soybean metabolism study were based on TRR calculated.

The major residues (>10% TRR) identified in soybean leaves were saflufenacil (63.8% of the TRR; 11.4 ppm), M800H02 (15.2% of the TRR; 2.72 ppm), and M800H01 (13.6% of the TRR; 2.44 ppm).  In soybean seed, the major residues identified were saflufenacil (26.1% of the TRR; 0.011 ppm), M800H02 (26.3% of the TRR; 0.011 ppm), and M800H11 (10.9% of the TRR; 0.004 ppm).  The only major residue identified in soybean pod was saflufenacil (76.4% of the TRR; 1.42 ppm).  In soybean stem, the major residues identified were saflufenacil (73.2% of the TRR; 0.306 ppm) and M800H02 (18.2% of the TRR; 0.076 ppm).  These results are summarized in Table 6.

Table 6.  Summary of Characterization and Identification of Radioactive Residues in Soybean Matrices Following a 2X Post-emergence Treatment with [Uracil-U-[14]C]-Saflufenacil.
Compound
                                     Stem
                                     Pod
                                     Seed
                                    Leaves

                                TRR = 0.419 ppm
                                TRR = 1.859 ppm
                                TRR = 0.043 ppm
                                TRR = 17.92 ppm

                                      ppm
                                     %TRR
                                      ppm
                                     %TRR
                                      ppm
                                     %TRR
                                      ppm
                                     %TRR
Saflufenacil
                                    0.306
                                     73.2
                                    1.420
                                     76.4
                                    0.011
                                     26.1
                                    11.431
                                     63.8
M800H01
                                       -
                                       -
                                    0.048
                                      2.6
                                       -
                                       -
                                    2.441
                                     13.6
M800H02
                                    0.076
                                     18.2
                                    0.115
                                      6.2
                                    0.011
                                     26.3
                                    2.716
                                     15.2
M800H03
                                       -
                                       -
                                    0.010
                                      0.6
                                       -
                                       -
                                    1.589
                                      8.9
M800H11
                                    0.031
                                      7.5
                                    0.054
                                      2.9
                                    0.004
                                     10.9
                                    0.952
                                      5.3
Total identified + characterized
                                    0.420
                                     100.3
                                    1.769
                                     95.1
                                    0.036
                                     84.6
                                    19.493
                                     108.8
Unextractable (PES)[1]
                                    0.009
                                      2.0
                                    0.061
                                      3.3
                                    0.002
                                      5.1
                                    0.103
                                      0.6
[1]  Residues remaining after exhaustive extractions.

The proposed metabolic pathway of radiolabeled saflufenacil in soybean following post-emergence treatment is outlined in Figure 1 and can be described as:

         * N-demethylation of the 3-methyl group of the uracil ring to form M800H02;
         * N-demethylation of the N-isopropyl-N-methylsulfamide side chain to generate M800H01 and elimination of the respective N-isopropyl group to generate M800H03; and
         * Demethylation of the N-isopropyl-N-methylsulfamide side chain and N-demethylation of the uracil ring to generate M800H11.

FIGURE 1.  Metabolic Profile of Saflufenacil in Soybean following Post-emergence Treatment.

Conclusions:  The previously-submitted metabolism data for corn, soybean, and tomato were adequate to elucidate the nature of the residue in plants resulting from pre-plant/pre-emergence application.  The main reactions involved in the metabolic pathway of saflufenacil were N-demethylation at the uracil ring, stepwise degradation (N-dealkylation) of the N-methyl-N-isopropyl group, hydrolytic cleavage of the uracil ring generating a urea side chain, and hydroxylation of the phenyl ring.  The HED ROCKS determined that residues of concern for the tolerance expression and risk assessment consist of saflufenacil, M800H11, and M800H35 (Memo, B. Daiss, 1/6/09; D359645).  The proposed metabolic pathway of radiolabeled saflufenacil in soybean following post-emergence treatment follows the same initial pathways, but is not as extensive (comparison of Figure 1 with Figure 2).  No new metabolites were observed following post-emergence treatment; however, an additional major metabolite (M800H02), that is not included in the tolerance expression, was observed in soybean seed.  As the structure of M800H02 is closely related to the parent compound and it is the precursor of the regulated metabolite M800H11, HED concludes that M800H02 is a residue of concern for risk-assessment purposes in seed crops following post-emergence treatment.

FIGURE 2.  Metabolic Profile of Saflufenacil in Soybean following Pre-emergence Treatment.
soil
metabolites
860.1300 Nature of the Residue - Livestock
Conclusions:  No new livestock metabolism data were submitted with these petitions.  The previously-submitted goat and poultry metabolism data are adequate to satisfy data requirements. Saflufenacil was metabolized by several dealkylation steps occurring at two different sites in the molecule (N-isopropyl-N-methylsulfamide side chain and at the uracil ring) and via hydrolytic opening of the uracil ring (goat only).  In the ruminant metabolism study, saflufenacil was a major residue in all matrices.  Only M800H04, a ring opening product, exceeded 10% of the TRR and 0.05 ppm (liver; 14.2% of the TRR, 0.543 ppm).  In the poultry metabolism study, saflufenacil was a major residue in all matrices and no metabolites exceeded 10% of the TRR and 0.05 ppm.  The HED ROCKS determined that saflufenacil per se is the only residue of concern for the tolerance expression and risk assessment (Memo, B. Daiss, 1/6/09; D359645).  The decision to exclude the plant metabolites M800H11 and M800H35 as residues of concern in livestock was based on the low potential for exposure associated with the previously proposed uses and should be reevaluated if additional proposed uses result in a significant increase in the livestock dietary burden.  The post-emergence uses proposed with action do result in a significant increase in the livestock dietary burden; however, metabolites M800H11 and M800H35 are not major residues in soybeans following a desiccation application.  M800H02 does not need to be included as a residue of concern as its concentration in soybean leaves is 4-5X lower than the parent compound.  HED thus concludes that saflufenacil per se is still the only residue of concern for the tolerance expression and risk assessment in livestock.

860.1340 Residue Analytical Methods

BASF Method D0603/02 is the current enforcement method for determination of residues of saflufenacil and its metabolites M800H11 and M800H35 in different plant matrices.  Residues of saflufenacil and its metabolites M800H11 and M800H35 were extracted from non-oily crop matrices with methanol:water (70:30; v:v).  The methanol extract, or in some matrices the concentrated methanol extract, was partitioned with a mixture of ethyl acetate-cyclohexane (70:30; v:v) and 0.1% trifluoroacetic acid (TFA).  An aliquot of the organic phase was evaporated and reconstituted in methanol:water (50:50; v:v) for LC-MS/MS analysis.  Oily crops were extracted with methanol:water (70:30; v:v) and pre-partitioned with isooctane.  An aliquot of the aqueous methanol phase or the concentrated methanol phase was partitioned with a mixture of ethyl acetate-cyclohexane (70:30; v:v) and 0.1% TFA.  An aliquot of the organic phase was evaporated and reconstituted in methanol:water (50:50; v:v) for LC-MS/MS quantitation.  For the residues in oil matrices (corn oil), samples were extracted with acetonitrile.  Following partitioning of the acetonitrile extract with isooctane (3 times), an aliquot of the acetonitrile layer was diluted with methanol-water (50:50; v:v) for LC-MS/MS determination.  Two transitions per analyte were monitored for the quantitation and confirmation of saflufenacil, M800H11 and M800H35.  The residues of each analyte were expressed as parent equivalents using a molecular weight conversion factor (1.0 for saflufenacil, 1.06 for M800H11, and 1.42 for M800H35).  The LOQ was 0.01 ppm for each analyte in food matrices (human consumption) and 0.025 ppm for each analyte in feed matrices (livestock consumption).  The limit of detection (LOD) was not tested, but set at 20% of LOQ.

Recovery samples, prepared at levels of LOQ and 10X LOQ in each matrix, were generally within the acceptable range of 70-120%.  The method detector response was determined to be linear in the range of 0.05-0.5 ng/mL (r >=0.98).
860.1360 Multiresidue Methods (MRM)

Saflufenacil and its metabolites M800H11 and M800H35 were screened through the MRM described in the United States Food and Drug Administration (FDA) Pesticide Analytical Manual, Vol. I (PAM I).  Saflufenacil and the metabolites were tested using procedures outlined in Protocols B, C, D, E, and F of the MRM.  All Protocols B, C, D, E, and F were found to be unsuitable for determination of residues of saflufenacil and its metabolites M800H11 and M800H35.  Since the analytes are not N-methyl-carbamates, naturally fluorescent or substituted urea derivatives, the tests using Protocol A and G were not performed.

860.1380 Storage Stability

Plant commodities

DER Reference List	47523801.der.doc

Samples of corn (forage, grain, and stover), garbanzo bean (chickpea), orange (fruit, juice, oil, and pulp), radish roots, grape (raisin), and soybean (forage, hay, and seed) were fortified separately with saflufenacil, M800H11, and M800H35 at a level of 1.0 ppm each and were stored at <-5ºC for a duration of 0, 44, 130, 214, 410-422, and 548-553 days (approximately 0, 1.5, 4.3, and 7.1, 13.7-14.1, and 18.3-18.4 months).  The samples were analysed for residues of saflufenacil and the metabolites M800H11 and M800H35 by LC-MS/MS using BASF Analytical Method Number D0603/02.  The freezer storage stability results were corrected for mean concurrent recovery values obtained from freshly fortified samples.

Under these conditions, residues of saflufenacil and its metabolites M800H11 and M800H35 are stable in/on corn (grain, forage, stover); soybean (seed, forage, hay); orange (fruit, pulp, juice, oil); radish (root); grape (raisin); and garbanzo bean (seed) commodities during frozen storage for up to 548 days.

Sample storage conditions and intervals

The storage intervals and conditions of samples from the residue field trials, rotational crop field trials, and processing studies which were submitted to support this petition are presented in Table 7.

Table 7.  Summary of Storage Conditions and Intervals of Samples from Crop Field Trial, Processing, and Field Rotational Crop Studies.
Matrix
                           Storage Temperature (°C)
                   Actual Storage Duration for Most Samples
                  Interval of Demonstrated Storage Stability
Dry Bean (MRID 48080902)
Bean, Dried Seed
                                    <-5
                                  69-163 days
                                   548 days
Dry Pea (MRID 48080903)
Pea, dried seed (dried shelled peas)
                                    <-5
                                 122-189 days
                                   548 days
Pea, vines

                                 151-269 days

Soybean (MRID 48080904 & 48080905)
Soybean, seed (dried)
                                    <-5
                                  93-181 days
                                   548 days
Flour, Hulls, Meal, Refined Oil, Soy milk, Tofu, AGFs

                                  15-30 days

Canola (MRID 48135201 & 48135202)
Canola, seed (dried)
                                    <-5
                               Maximum, 299 days
                                   548 days
Meal, Refined oil

                                  98-217 days

Cotton (MRID 48080906)
Undelinted seed and gin byproducts
                                    <-5
                                   214 days
                                   548 days
Hulls, Meal, Crude oil, Refined oil

                                   112 days

Conclusions:  Adequate storage stability data have been submitted.  Residues of saflufenacil, M800H11, and M800H35 were stable (<30% degradation) in all plant matrices during freezer storage for up to 548 days.  These data support the storage conditions and intervals of samples collected from the various crop field trials.  There are no unresolved storage stability issues, and no corrections need to be applied to the various magnitude of the residue studies.

860.1480 Meat, Milk, Poultry, and Eggs

Livestock dietary burdens

The potential for secondary transfer of saflufenacil residues of concern in meat, milk, and eggs exists because there are livestock feedstuffs associated with the existing and proposed uses.  The livestock dietary burdens of saflufenacil and its metabolites are presented in Tables 8a-8d and reflect the most recent guidance from HED (June, 2008) concerning revisions of feedstuff percentages in Table 1 and constructing RBDBs.  The calculated total dietary burdens of saflufenacil and its metabolites (based on tolerance-level residues) are 0.13 ppm for beef cattle, 0.77 ppm for dairy cattle, 0.27 ppm for poultry, and 0.18 ppm for swine.

Table 8a.  Beef Cattle Dietary Burden Contribution for Saflufenacil.
Feedstuff
                                    Type[1]
                                   Tolerance
                                     (ppm)
                                 % Dry Matter
                                   % Diet[2]
                         Dietary Contribution (ppm)[3]
Target % Diet Roughage
                                      15

Corn, field, forage
                                       R
                                     0.10
                                      40
                                      10
                                     0.025
Cotton, gin byproducts
                                       R
                                     0.45
                                      90
                                       5
                                     0.025

Target % Diet Carbohydrate Concentrate
                                      80

Corn, field, grain
                                      CC
                                     0.03
                                      88
                                      80
                                     0.027

Target % Diet Protein Concentrate
                                       5

Sunflower meal
                                      PC
                                      1.0
                                      92
                                       5
                                     0.054
TOTALS
                                      100
                                     0.13

Table 8b.  Dairy Cattle Dietary Burden Contribution for Saflufenacil.
Feedstuff
                                    Type[1]
                                   Tolerance
                                     (ppm)
                                 % Dry Matter
                                   % Diet[2]
                         Dietary Contribution (ppm)[3]
Target % Diet Roughage
                                      45

Field pea, hay
                                       R
                                    4.88[4]
                                      88
                                      10
                                     0.55
Corn, field, forage
                                       R
                                     0.10
                                      40
                                      35
                                     0.09

Target % Diet Carbohydrate Concentrate
                                      45

Corn, field, grain
                                      CC
                                     0.03
                                      88
                                      45
                                     0.015

Target % Diet Protein Concentrate
                                      10

Sunflower meal
                                      PC
                                      1.0
                                      92
                                      10
                                     0.11
TOTALS
                                      100
                                     0.77

Table 8c.  Poultry Dietary Burden Contribution for Saflufenacil.
Feedstuff
                                    Type[1]
                                   Tolerance
                                     (ppm)
                                 % Dry Matter
                                   % Diet[2]
                         Dietary Contribution (ppm)[3]

Target % Diet Carbohydrate Concentrate
                                      75

Corn, field, grain
                                      CC
                                     0.03
                                      --
                                      75
                                     0.022

Target % Diet Protein Concentrate
                                      25

Sunflower meal
                                      PC
                                      1.0
                                      --
                                      25
                                     0.25
TOTALS
                                      100
                                     0.27

Table 8d.  Swine Dietary Burden Contribution for Saflufenacil.
Feedstuff
                                    Type[1]
                                   Tolerance
                                     (ppm)
                                 % Dry Matter
                                   % Diet[2]
                         Dietary Contribution (ppm)[3]

Target % Diet Carbohydrate Concentrate
                                      85

Corn, field, grain
                                      CC
                                     0.03
                                      --
                                      85
                                     0.026

Target % Diet Protein Concentrate
                                      15

Sunflower meal
                                      PC
                                      1.0
                                      --
                                      15
                                     0.15
TOTALS
                                      100
                                     0.18
[1]  R:  Roughage; CC:  Carbohydrate concentrate; PC:  Protein concentrate.
[2]  OPPTS 860.1000 Table 1 Feedstuffs (June 2008).
[3]  Dietary contribution = tolerance /% dry matter x % diet (for poultry and swine % dry matter is not considered).
4  The maximum residue for pea hay (4.88 ppm) was used in these calculations due to the large difference as compared to the recommended tolerance (17 ppm).  This process will allow harmonization with Canadian MRLs.

Dairy cattle feeding study

Saflufenacil was administered orally in treated feed to 14 Friesian dairy cows for 28-29 consecutive days (Table 9).  The target doses were 0.1 (0.13X), 0.3 (0.39X), and 1.0 ppm (1.3X).  In whole milk samples, residues of saflufenacil were <0.01 ppm (<LOQ) over the entire 28- to 29-day dosing period.  Residues of saflufenacil did not concentrate in samples of skim milk (<0.01 ppm) or cream (<0.01 ppm).  In tissues, residues of saflufenacil were not quantifiable in fat (<0.01 ppm) or muscle (<0.01 ppm).  There was a linear relationship between the feeding level and residues of saflufenacil in kidney and liver.  Residues of saflufenacil in kidney were <0.01 ppm at the 0.1-ppm dose level, 0.02 ppm at the 0.3-ppm dose level and ranged from 0.03 ppm to 0.04 ppm at the 1.0-ppm dose level.  In liver, residues of saflufenacil ranged from 0.17 ppm to 0.26 ppm at the 0.1-ppm dose level, 0.67 ppm to 0.88 ppm at the 0.3-ppm dose level, and from 2.09 ppm to 3.49 ppm at the 1.0-ppm dose level.

Following withdrawal of the dose, residues of saflufenacil were <0.01 ppm (<LOQ) in samples of whole milk, muscle, and fat on day 30 and day 35 of the study.  In kidney, residues of saflufenacil decreased from 0.03 ppm at day 30 to <0.01 ppm at day 35.  In liver, residues of saflufenacil decreased from 1.66 ppm at day 30 to 0.34 ppm at day 35.  Half lives of 2.5 and 4.0 days were calculated for saflufenacil residues in liver and kidney, respectively.

Table 9.  Summary of Residue Data from Ruminant Feeding Study with Saflufenacil.[1]
Matrix
                          Target Feeding Level (ppm)
                             Residue Levels (ppm)

                                       n
                                     Min.
                                     Max.
                                    Median
                                     Mean
                                   Std. Dev.
Whole milk/day 1-28/29
Skim milk/day 22
Cream/day 22
                                       0
                                       3
                                   <0.01
                                   <0.01
                                   <0.01
                                   <0.01
                                       0

                                  0.1 (0.13X)
                                       3
                                   <0.01
                                   <0.01
                                   <0.01
                                   <0.01
                                       0

                                  0.3 (0.39X)
                                       3
                                   <0.01
                                   <0.01
                                   <0.01
                                   <0.01
                                       0

                                  1.0 (1.3X)
                                       5
                                   <0.01
                                   <0.01
                                   <0.01
                                   <0.01
                                       0
Fat
                                       0
                                       3
                                   <0.01
                                   <0.01
                                   <0.01
                                   <0.01
                                       0

                                  0.1 (0.13X)
                                       3
                                   <0.01
                                   <0.01
                                   <0.01
                                   <0.01
                                       0

                                  0.3 (0.39X)
                                       3
                                   <0.01
                                   <0.01
                                   <0.01
                                   <0.01
                                       0

                                  1.0 (1.3X)
                                       3
                                   <0.01
                                   <0.01
                                   <0.01
                                   <0.01
                                       0
Muscle
                                       0
                                       3
                                   <0.01
                                   <0.01
                                   <0.01
                                   <0.01
                                       0

                                  0.1 (0.13X)
                                       3
                                   <0.01
                                   <0.01
                                   <0.01
                                   <0.01
                                       0

                                  0.3 (0.39X)
                                       3
                                   <0.01
                                   <0.01
                                   <0.01
                                   <0.01
                                       0

                                  1.0 (1.3X)
                                       3
                                   <0.01
                                   <0.01
                                   <0.01
                                   <0.01
                                       0
Liver
                                       0
                                       3
                                   <0.01
                                   <0.01
                                   <0.01
                                   <0.01
                                       0

                                  0.1 (0.13X)
                                       3
                                     0.17
                                     0.26
                                     0.19
                                     0.21
                                     0.047

                                  0.3 (0.39X)
                                       3
                                     0.67
                                     0.88
                                     0.76
                                     0.77
                                     0.105

                                  1.0 (1.3X)
                                       3
                                     2.09
                                     3.49
                                     2.25
                                     2.61
                                     0.77
Kidney
                                       0
                                       3
                                   <0.01
                                   <0.01
                                   <0.01
                                   <0.01
                                       0

                                  0.1 (0.13X)
                                       3
                                   <0.01
                                   <0.01
                                   <0.01
                                   <0.01
                                       0

                                  0.3 (0.39X)
                                       3
                                     0.02
                                     0.02
                                     0.02
                                     0.02
                                       0

                                  1.0 (1.3X)
                                       3
                                     0.03
                                     0.04
                                     0.04
                                     0.037
                                     0.006
[1]  The LOQ for saflufenacil in all matrices analyzed was reported as 0.01 ppm.

Expected secondary residues in meat and milk

To determine the need for tolerances for saflufenacil residues in milk and tissues, the anticipated secondary residues in cattle matrices were estimated using transfer coefficient factors calculated from the maximum residues of saflufenacil observed in the ruminant feeding study.  The transfer coefficients (calculated as residue-level-to-feed ratios) are presented in Table 10.  The transfer coefficient for each matrix was then used to calculate the expected secondary residues by multiplying the transfer coefficient by the calculated dietary burden (Table 8b).

Table 10.  Residue-Level-to-Feed Ratios (Transfer Coefficients) in Dairy Cattle Milk and Tissues.[1]
Matrix
                             Maximum Residue (ppm)
                              Feeding Level, ppm
                             Transfer Coefficient
Milk/Cream
                                   <0.01
                                      1.0
                                   <0.01
Fat
                                   <0.01

                                   <0.01
Muscle
                                   <0.01

                                   <0.01
Kidney
                                     0.02
                                      0.3
                                     0.067
                                 Ave. = 0.054

                                     0.04
                                      1.0
                                     0.04

Liver
                                     0.26
                                      0.1
                                      2.6
                                  Ave. = 3.0

                                     0.88
                                      0.3
                                      2.9

                                     3.49
                                      1.0
                                     3.49

[1]  Calculated from the maximum residues divided by the dose level.

Table 11.  Expected Secondary Residues in Meat and Milk.
Matrix
                             Dietary burden (ppm)
                          Secondary Residues (ppm)[1]
                          Established Tolerance (ppm)
                          Recommended Tolerance (ppm)
Milk
                                     0.77
                                  <0.0077
                                     0.01
                                     0.01
Fat

                                  <0.0077
                                     0.01
                                     0.01
Kidney

                                     0.042
                                    0.02[2]
                                    0.05[2]
Muscle

                                  <0.0077
                                     0.01
                                     0.01
Liver

                                      2.3
                                     0.80
                                      2.5
[1]  Calculated from dietary burden x average transfer coefficient from Table 10.
[2]  Meat byproducts, except liver.

Conclusions:  The feeding study data indicate that the established tolerances should be increased to 2.5 ppm for residues in liver and 0.05 ppm for residues in meat byproducts except liver; and do not need to be increased in fat and meat of cattle, goats, horses, and sheep, and in milk.  The tolerances for hog commodities do not need to be increased as the hog RBDB did not increase.

Poultry feeding study waiver request

HED previously agreed to waive the data requirement for a poultry feeding study.  As the poultry RBDB is unchanged by the proposed new used, this waiver is still appropriate.

860.1500 Crop Field Trials

Dry Bean

DER Reference List	48080902.der.doc

BASF Corporation has submitted field trial data for saflufenacil on dried shelled beans (Phaseolus spp.).  Ten bean field trials were conducted in North American Free Trade Agreement (NAFTA) Growing Zones 5 (MO, ND, IA, and WI; one trial each), 7 (ND, one trial), 7A (AB, one trial), 8 (KS, one trial), 9 (UT, one trial), 10 (CA, one trial), and 11 (ID, one trial).

Each trial location consisted of one untreated and one treated plot.  Each treated plot received a single harvest aid/desiccant broadcast application of the 70% WG formulation of saflufenacil (BAS 800 00 H) at 0.044-0.046 lb ai/A (1X).  The applications were made using ground equipment with 16-30 gal/A spray volumes.  An adjuvant (methylated seed oil, Merge[(TM)]) was included in the spray mixture, together with ammonium sulfate fertilizer.

Samples of mature dried seed were harvested at a 2-day PHI.  At one trial in ID, additional treated samples were collected at 0, 1, 7, and 10 days after the last application to evaluate residue decline.

The results from these trials on bean show that after a single harvest aid/desiccant broadcast application of saflufenacil applied as a harvest aid/desiccant targeting 0.045 lb ai/A, maximum saflufenacil residues were 0.23 ppm in/on bean dried seed samples harvested at a 2-day PHI; M800H11 and M800H35 residues were below the LOQ (<0.01 ppm each) in/on all samples (Table 12).  Maximum combined residues of saflufenacil in/on dried seed were <0.25 ppm at the 2-day PHI.

In the residue-decline experiment, after an initial increase during the period immediately following application, saflufenacil residues decreased at longer post-treatment intervals.  Mean saflufenacil residues in/on bean, dried seed, were 0.01 ppm on the day of the application, were 0.03 ppm at 1 DAT, were a maximum of 0.10 ppm at 2 DAT, and declined to 0.03 ppm at 7 and 10 DAT; M800H11 and M800H35 were <0.01 ppm each in all samples at all sampling intervals.

Table 12.  Summary of Residue Data from Crop Field Trials with Saflufenacil.
Commodity
                         Total Applic. Rate (lb ai/A)
                                  [kg ai/ha]
                                  PHI (days)
                                    Analyte
                            Residue Levels (ppm)[1]

                                       n
                                     Min.
                                     Max.
                                    HAFT[2]
                                    Median
                                     Mean
                                   Std. Dev.
Bean, Dried, Seed
                                  0.044-0.046
                                 [0.049-0.052]
                                       2
                                 Saflufenacil
                                      20
                                   <0.01
                                     0.23
                                     0.16
                                   <0.01
                                     0.05
                                     0.07

                                    M800H11
                                      20
                                   <0.01
                                   <0.01
                                   <0.01
                                   <0.01
                                   <0.01
                                     0.00

                                    M800H35
                                      20
                                   <0.01
                                   <0.01
                                   <0.01
                                   <0.01
                                   <0.01
                                     0.00

                                  Combined[3]
                                      20
                                   <0.03
                                   <0.25
                                   <0.18
                                   <0.03
                                   <0.07
                                     0.07
[1]  For calculation of the HAFT, median, mean, and standard deviation, seed residue values of  <0.01 ppm (<LOQ) were considered to be 0.01 ppm (LOQ).
[2]  HAFT = highest-average field trial.
[3]  Combined residues of saflufenacil (parent + M800H11 + M800H35).

Conclusions:  The submitted residue data are adequate to fulfill data requirements for dried shelled beans as a representative crop of Crop Subgroup 6C, Dried shelled pea and bean (except soybean) subgroup.  The number and locations of the crop field trials are in accordance with OPPTS Guideline 860.1500 (Table 13).  The available data will support the proposed use pattern.

Table 13.  Trial Numbers and Geographical Locations.
NAFTA Growing Zones
                          Bean (dried shelled beans)

                                   Submitted
                                 Requested[1]

                                    Canada
                                     U.S.
1

                                      1/0
5
                                       4
                                       4
                                      5/4
7
                                       1

                                      2/1
7A
                                       1
                                       1

8
                                       1

                                      1/1
9
                                       1

                                      1/1
10
                                       1

                                      1/1
11
                                       1

                                      1/1
Total
                                      10
                                       5
                                     12/9
[1]  As required under US EPA OPPTS 860.1500 for dried bean, and PMRA Directive 98-2.
[2]  The second number is used when the representative commodity is used to obtain a crop group tolerance.

The residue data for dried shelled beans were entered into the Agency's tolerance spreadsheet as specified by the Guidance for Setting Pesticide Tolerances Based on Field Trial Data; see Appendix II.  The recommended tolerance for the combined residues of saflufenacil and its metabolites M800H11 and M800H35, expressed as parent equivalents, is 0.30 ppm for Crop Subgroup 6C, Dried shelled pea and bean (except soybean) subgroup.

Dry Peas

DER Reference List	48080903.der.doc

BASF Corporation has submitted field trial data for saflufenacil on dried shelled peas (Pisum spp.).  Nine pea field trials were conducted in NAFTA Growing Zones 5 (ND and WI; one trial each), 11 (ID, two trials; OR, one trial), and 14 (AB and MB, one trial each; SK, two trials).

Each trial location consisted of one untreated and one treated plot.  Each treated plot received a harvest aid/desiccant broadcast application of the 70% WG formulation of saflufenacil (BAS 800 00 H) applied at 0.044-0.046 lb ai/A (1X).  The applications were made using ground equipment with 19-33 gal/A spray volumes.  An adjuvant (methylated seed oil, Merge[(TM)]) was included in the spray mixture, together with ammonium sulfate fertilizer.  Samples of mature pea seed and vines were harvested at a 2- to 4-day PHI.  At one trial in ID, additional treated samples were collected at 0, 1, 7, and 10 days after the last application, to evaluate residue decline.

The results from these pea trials show that after a single harvest aid/desiccant broadcast application of saflufenacil (70% WG, BAS 800 00 H) targeting 0.045 lb ai/A, maximum saflufenacil residues were 0.05 ppm in/on pea dried seed samples harvested at a 2-4 day PHI; M800H11 and M800H35 residues were below the LOQ (<0.01 ppm each) in/on all samples (Table 14).  Maximum combined residues of saflufenacil in/on dried seed were <0.07 ppm at the 2- to 4-day PHI.  Maximum residues of saflufenacil, M800H11, and M800H35 were 4.83, 0.13, and <0.025 ppm, respectively, in/on pea vines harvested at a 2- to 4-day PHI after a single broadcast foliar application of saflufenacil (70% WG, BAS 800 00 H) targeting 0.045 lb ai/A.  Maximum combines residues of saflufenacil in pea vines were <4.88 ppm.

In the residue-decline experiment, average parent saflufenacil residues in/on seed decreased overall with increasing sampling intervals, from 0.05 ppm at the 0-day PHI to <0.01 ppm at the 10-day PHI.  Average parent saflufenacil residues in/on pea vines also decreased with increasing sampling intervals, from 3.45 ppm at the 0-day PHI to 0.69 ppm at the 10-day PHI.  Residues of the metabolites M800H11 and M800H35 were below the respective LOQs in/on all seed and vines samples (<0.01 or <0.025 ppm) collected from the residue decline experiment.  The residue decline data indicate that residues of saflufenacil in pea seed and vines decrease at longer PHIs.

Table 14.  Summary of Residue Data from Crop Field Trials with Saflufenacil.
Commodity
                         Total Applic. Rate (lb ai/A)
                                  [kg ai/ha]
                                  PHI (days)
                                    Analyte
                            Residue Levels (ppm)[1]

                                       n
                                     Min.
                                     Max.
                                    HAFT[2]
                                    Median
                                     Mean
                                   Std. Dev.
Pea, dried seed
(dried shelled seed)
                                  0.044-0.046
                                 [0.049-0.051]
                                      2-4
                                 Saflufenacil
                                      18
                                   <0.01
                                     0.05
                                     0.04
                                   <0.01
                                     0.02
                                     0.01

                                    M800H11

                                   <0.01
                                   <0.01
                                   <0.01
                                   <0.01
                                   <0.01
                                     0.00

                                    M800H35

                                   <0.01
                                   <0.01
                                   <0.01
                                   <0.01
                                   <0.01
                                     0.00

                                  Combined[3]

                                   <0.03
                                   <0.07
                                   <0.06
                                   <0.03
                                   <0.04
                                     0.01
Pea, vines
                                  0.044-0.046
                                 [0.049-0.051]
                                      2-4
                                 Saflufenacil
                                      18
                                     0.09
                                     4.83
                                     4.56
                                     1.72
                                     2.12
                                     1.58

                                    M800H11

                                   <0.025
                                     0.13
                                     0.13
                                     0.04
                                     0.05
                                     0.04

                                    M800H35

                                   <0.025
                                   <0.025
                                   <0.025
                                   <0.025
                                   <0.025
                                     0.00

                                  Combined[3]

                                   <0.23
                                   <4.88
                                   <4.61
                                     1.95
                                     2.31
                                     1.61
[1]  For calculation of the HAFT, median, mean, and standard deviation, seed residue values of <0.01 ppm (<LOQ) were considered to be 0.01 ppm (LOQ), and vine residue values of <0.025 ppm (<LOQ) were considered to be 0.025 ppm.
[2]  HAFT = highest-average field trial.
[3]  Combined residues of saflufenacil (parent + M800H11 + M800H35).

Conclusions:  The submitted residue data are adequate to fulfill data requirements for dried shelled peas as a representative crop of Crop Subgroup 6C, Dried shelled pea and bean (except soybean) subgroup.  The number and locations of the trials are in accordance with OPPTS Guideline 860.1500 (Table 15).  The available data will support the proposed use pattern.
Table 15.  Trial Numbers and Geographical Locations.
NAFTA Growing Zones
               Peas (dried cultivars of shelled pea, Pisum spp.)

                                   Submitted
                                 Requested[1]

                                    Canada
                                     U.S.
5
                                       2
                                       2

11
                                       3

14
                                       4
                                       6

Total
                                       9
                                       8
                                       5
[1]  As required under US EPA OPPTS 860.1500 for pea, and PMRA Directive 98-2.  The guidelines do not specifically state the geographical distribution needed for a national registration on dried shelled peas; however, the trials were located in the areas of highest crop production for dried shelled peas.

The residue data for dried shelled peas were not entered into the Agency's tolerance spreadsheet as specified by the Guidance for Setting Pesticide Tolerances Based on Field Trial Data SOP as the residues significantly were less than those in dried shelled beans.  The results from the dried shelled bean trials will thus be used to set the pea and bean, dried shelled, except soybean, subgroup 6C subgroup tolerance.  The residue data for dried pea vines were entered into the Agency's tolerance spreadsheet as specified by the Guidance for Setting Pesticide Tolerances Based on Field Trial Data.  HED notes that, as defined in OPPTS 860.1000 Table 1, the commodity identified by the petitioner as "vines" is actually hay (i.e., desiccated vines).  The recommended tolerance for the combined residues of saflufenacil and its metabolites M800H11 and M800H35, expressed as parent equivalents, is 17 ppm for pea hay.

Soybean

DER Reference List	48080904.der.doc

Field trial data have been generated for saflufenacil on soybean.  A total of 20 field trials on soybean (dried) were conducted during the 2009 growing season in NAFTA Growing Zones 2 (SC and GA, one trial each); 4 (MO, AR and MS, one trial each); and 5 (IA, KS, MN, MO, ND, and WI, two trials each; IL, OH, and ON, one trial each).

Each trial location consisted of one untreated and one treated plot.  Each treated plot received a single harvest aid/desiccant, broadcast application of the 70% WG formulation of saflufenacil at 0.043-0.046 lb ai/A (1X, Treatment 02).  In addition, at three trial sites, a "side-by-side" bridging comparison plot was treated in the same manner with a single late-season, broadcast application of the 342 g/L SC formulation of saflufenacil applied at 0.046 lb ai/A (1X, Treatment 03).  The applications were made using ground equipment with 14-38 gal/A spray volumes.  An adjuvant (methylated seed oil, Merge[(R)]) was included in the spray mixture, together with ammonium sulfate fertilizer.  Samples of mature soybean dried seed were harvested at a 2- to 4-day PHI.  At two trials, including one at which both formulations were tested, additional treated samples were collected at 0, 1, 7, and 10 days after the last application, in addition to the targeted 3+-1 day PHI, to evaluate residue decline.

The results from these trials on soybean show that after a single late-season, broadcast application of saflufenacil applied at 0.045 lb ai/A, maximum saflufenacil residues were 0.05 ppm in/on soybean dried seed samples harvested at a 2-4 day PHI; M800H11 and M800H35 residues were below the LOQ (<0.01 ppm each) in/on all samples (Table 16).  Maximum combined residues of saflufenacil in/on dried seed were <0.07 ppm at the 2-4 day PHI.  The "side-by-side" bridging trials comparing the two formulations (WG vs. SC) demonstrated that there was no substantial difference in residues in soybean treated with the two formulations.  The residue decline data suggest that residues of saflufenacil decrease at longer PHIs.

Table 16.  Summary of Residue Data from Crop Field Trials with Soybeans.
Commodity; Treatment
                         Total Applic. Rate (lb ai/A)
                                  [kg ai/ha]
                                  PHI (days)
                                    Analyte
                            Residue Levels (ppm)[1]

                                       n
                                     Min.
                                     Max.
                                    HAFT[2]
                                    Median
                                     Mean
                                   Std. Dev.
Soybean, dried seed;

Treatment 2
(WG formulation)
                                  0.043-0.046
                                 [0.049-0.051]
                                      2-4
                                 Saflufenacil
                                      40
                                   <0.01
                                     0.05
                                     0.05
                                   <0.01
                                   <0.01
                                     0.01

                                    M800H11

                                   <0.01
                                   <0.01
                                   <0.01
                                   <0.01
                                   <0.01
                                     0.00

                                    M800H35

                                   <0.01
                                   <0.01
                                   <0.01
                                   <0.01
                                   <0.01
                                     0.00

                                  Combined[3]

                                   <0.03
                                   <0.07
                                   <0.07
                                   <0.03
                                   <0.03
                                     0.03
Soybean, dried seed;

Treatment 3
(SC formulation)
                                     0.046
                                    [0.051]
                                       3
                                 Saflufenacil
                                       6
                                   <0.01
                                     0.03
                                     0.02
                                   <0.01
                                     0.02
                                     0.01

                                    M800H11

                                   <0.01
                                   <0.01
                                   <0.01
                                   <0.01
                                   <0.01
                                     0.00

                                    M800H35

                                   <0.01
                                   <0.01
                                   <0.01
                                   <0.01
                                   <0.01
                                     0.00

                                  Combined[3]

                                   <0.03
                                   <0.05
                                   <0.04
                                   <0.03
                                   <0.04
                                     0.04
Soybean, dried seed;

Both Treatments
                                  0.043-0.046
                                 [0.049-0.051]
                                      2-4
                                 Saflufenacil
                                      46
                                   <0.01
                                     0.05
                                     0.05
                                   <0.01
                                   <0.01
                                     0.01

                                    M800H11

                                   <0.01
                                   <0.01
                                   <0.01
                                   <0.01
                                   <0.01
                                     0.00

                                    M800H35

                                   <0.01
                                   <0.01
                                   <0.01
                                   <0.01
                                   <0.01
                                     0.00

                                  Combined[3]

                                   <0.03
                                   <0.07
                                   <0.07
                                   <0.03
                                   <0.03
                                     0.03
[1]  For calculation of the HAFT, median, mean, and standard deviation, seed residue values of <0.01 ppm (<LOQ) were considered to be 0.01 ppm (LOQ).
[2]  HAFT = highest-average field trial.
[3]  Combined residues of saflufenacil (parent + M800H11 + M800H35).
**  Note that additional samples collected to examine residue decline are not shown; only those samples collected at the targeted 3-day PHI.

Conclusions:  The submitted field trial data for soybean are adequate to fulfill data requirements.  The number and locations of the trials are in accordance with OPPTS Guideline 860.1500 (Table 17).  The available data will support the proposed use pattern.

Table 17.  Trial Numbers and Geographical Locations.
NAFTA Growing Zones
                                Soybean (dried)

                                   Submitted
                                 Requested[1]

                                    Canada
                                     U.S.
2
                                       2

                                       2
4
                                       3

                                       3
5
                                      15
                                      11
                                      15
5B

                                       1

Total
                                     20[2]
                                      12
                                      20
[1]  The requested number and geographic distribution of field trials for soybean, according to US EPA OPPTS 860.1500 and PMRA Directive 98-2.
[2]  One bridging trial in each region (three total trials) included side-by-side test plots comparing the WG and SC formulations.

The residue data for soybean were not entered into the Agency's tolerance spreadsheet as specified by the Guidance for Setting Pesticide Tolerances Based on Field Trial Data SOP as >75% of the residues were <LOQ.  The recommended tolerances for the combined residues of saflufenacil and its metabolites M800H11 and M800H35, expressed as parent equivalents, are 0.10 ppm for soybean seed.

Cotton

DER Reference List	48080906.de1.doc

Field trial data were generated for saflufenacil on cotton and conducted during the 2009 growing season at the following 12 locations:  NAFTA Growing Zone 2 (GA; one trial); Zone 4 (AR; 3 trials); Zone 6 (OK; one trial); Zone 8 (TX; 4 trials); and Zone 10 (CA; 3 trials).

Each location consisted of an untreated control plot (Treatment 1) and at least one treated plot (Treatment 2) at a plot size large enough to yield the required cotton samples.  One of the four sites in Region 8 collected additional samples to determine a residue decline profile.  Two sites, one each in Regions 2 and 8, had a second treated plot treated with an exaggerated rate to generate bulk samples of undelinted seed for simulated commercial processing.

The treated plots received a single harvest aid/desiccant broadcast application of BAS 800 00 H 70% WG at a target rate of 0.045 lb ai/A (1X).  The second treated plot at the trial locations in Regions 2 and 8 received an exaggerated rate targeted at 0.225 lb ai/A (5X).  The applications were made using typical ground boom equipment with a tank mix spray volume of about 30-40 gal/A, along with an adjuvant.

At five trial locations, samples of seed only were collected.  At the remaining seven trial locations, seed and gin byproducts consisting of stems, leaves, burrs, immature seed, and dust were collected including one trial which was sampled at five time points to generate a residue decline profile.  Mature seed cotton was harvested at a 5-day PHI, except for the decline trial in which mature seed cotton was collected at 1-, 4-, 5-, 10-, and 15-day PHIs.  Additionally, one untreated and one treated bulk samples were collected from the additional exaggerated rate treated plots at two trial locations.

After a single late-season, broadcast application of saflufenacil targeting 0.045 lb ai/A, maximum combined residues of saflufenacil were <0.14 ppm in/on undelinted seed samples harvested at a targeted 5-day PHI (parent, 0.12 ppm; M800H11, <0.01 ppm; M800H35, <0.01 ppm) (Table 18).  Maximum combined residues of saflufenacil were <2.30 ppm in/on cotton gin byproducts samples harvested at a targeted 5-day PHI (parent, 2.25 ppm; M800H11, <0.025 ppm; M800H35, <0.025 ppm).

The residue decline data indicated that residues of saflufenacil in undelinted seed RAC samples decrease at longer PHIs and for cotton gin byproducts residues decrease from days 1-4 and remain constant thereafter.

Table 18.  Summary of Residue Data from Crop Field Trials with Cotton.
Commodity; Treatment
                         Total Applic. Rate (lb ai/A)
                                  [kg ai/ha]
                                  PHI (days)
                                    Analyte
                            Residue Levels (ppm)[1]

                                       n
                                     Min.
                                     Max.
                                    HAFT[2]
                                    Median
                                     Mean
                                   Std. Dev.
Cotton, Undelinted seed
                                  0.043-0.046
                                    [0.050]
                                       5
                                 Saflufenacil
                                      24
                                   <0.01
                                     0.12
                                     0.11
                                     0.03
                                     0.04
                                     0.03

                                    M800H11
                                      24
                                   <0.01
                                   <0.01
                                   <0.01
                                   <0.01
                                   <0.01
                                     0.00

                                    M800H35
                                      24
                                   <0.01
                                   <0.01
                                   <0.01
                                   <0.01
                                   <0.01
                                     0.00

                                  Combined[3]
                                      24
                                   <0.03
                                   <0.14
                                   <0.13
                                   <0.05
                                   <0.06
                                     0.03
Cotton gin byproducts; stripper
                                  0.043-0.045
                                    [0.050]
                                       5
                                 Saflufenacil
                                       8
                                     0.14
                                     0.29
                                     0.22
                                     0.165
                                     0.188
                                     0.05

                                    M800H11
                                       8
                                   <0.025
                                   <0.025
                                   <0.025
                                   <0.025
                                   <0.025
                                     0.00

                                    M800H35
                                       8
                                   <0.025
                                   <0.025
                                   <0.025
                                   <0.025
                                   <0.025
                                     0.00

                                  Combined[3]
                                       8
                                   <0.19
                                   <0.34
                                   <0.27
                                   <0.215
                                   <0.234
                                     0.05
Cotton gin byproducts;
picker
                                  0.043-0.046
                                    [0.050]
                                       5
                                 Saflufenacil
                                       6
                                     0.08
                                     2.25
                                     2.08
                                     1.83
                                     1.34
                                     0.98

                                    M800H11
                                       6
                                   <0.025
                                   <0.025
                                   <0.025
                                   <0.025
                                   <0.025
                                     0.00

                                    M800H35
                                       6
                                   <0.025
                                   <0.025
                                   <0.025
                                   <0.025
                                   <0.025
                                     0.00

                                  Combined[3]
                                       6
                                   <0.13
                                   <2.30
                                   <2.13
                                   <1.88
                                   <1.34
                                     0.98
[1]  For calculation of the HAFT, median, mean, and standard deviation, seed residue values of <0.01 ppm (<LOQ) were considered to be 0.01 ppm (LOQ) and <0.025 for gin byproducts.
[2]  HAFT = highest-average field trial.
[3]  Combined residues of saflufenacil (parent + M800H11 + M800H35).
**  Note that additional samples collected to examine residue decline are not shown; only those samples collected at the targeted 5-day PHI.

Conclusions:  The submitted field trial data for cotton are adequate to fulfill data requirements.  The number and locations of the trials are in accordance with OPPTS Guideline 860.1500 (Table 19).  The available data will support the proposed use pattern.

Table 19.  Trial Numbers and Geographical Locations.
NAFTA Growing Zones
                                    Cotton

                                   Submitted
                                 Requested[1]

                                    Canada
                                     U.S.
2
                                       1
                                       -
                                       1
4
                                       3
                                       -
                                       3
6
                                       1
                                       -
                                       1
8
                                       4
                                       -
                                       4
10
                                       3
                                       -
                                       3
Total
                                      12
                                       -
                                      12
[1]  The requested number and geographic distribution of field trials for cotton, according to US EPA OPPTS 860.1500 and PMRA Directive 98-2.  OPPTS 860.1000, Table 1, specifies that two field trials must be conducted for cotton gin byproducts using stripper harvesting equipment.

The residue data for cottonseed were entered into the Agency's tolerance spreadsheet as specified by the Guidance for Setting Pesticide Tolerances Based on Field Trial Data SOP to determine appropriate tolerance levels; see Appendix II.  The recommended tolerance for the combined residues of saflufenacil and its metabolites M800H11 and M800H35, expressed as parent equivalents, is 0.20 ppm for cottonseed.  The residue data for cotton gin byproducts (stripper harvest) were entered into the Agency's tolerance spreadsheet as specified by the Guidance for Setting Pesticide Tolerances Based on Field Trial Data SOP to determine appropriate tolerance levels; see Appendix II.  In one of the trials, residues were higher at a PHI (10 days) that is greater than the proposed PHI (5 days).  In this case, the higher values were entered into the spreadsheet.  The recommended tolerance for the combined residues of saflufenacil and its metabolites M800H11 and M800H35, expressed as parent equivalents, is 0.45 ppm for cotton gin byproducts.

Rapeseed Subgroup 20A

Canola (representative crop for rapeseed subgroup 20A)

DER Reference List	48135201.der.doc

BASF Corporation has submitted field trial data for saflufenacil on rapeseed (canola varieties only).  Sixteen canola field trials were conducted during the 2009 growing season in NAFTA Growing Zones 2 (GA; one trial), 5 (MI, one trial), 7 (NE, one trial), 11 (ID, two trials), and 14 (MB, two trials; SK, four trials; and AB, five trials).

Each trial location consisted of one untreated and one treated plot.  Each treated plot received a single harvest aid/desiccant, broadcast application of the 70% WG formulation of saflufenacil at 0.044-0.046 lb ai/A (1X, Treatment 02).  In addition, at three trial sites, a "side-by-side" bridging comparison plot was treated in the same manner with a single late-season, broadcast application of the 342 g/L SC formulation of saflufenacil (BAS 800 04 H, SHARPEN[(TM)] Powered by KIXOR[(R)] Herbicide, EPA Reg. No. 7969-278) applied as a harvest aid/desiccant at 0.041-0.046 lb ai/A (1X, Treatment 03).  The applications were made using ground equipment with 14-33 gal/A spray volumes.  An adjuvant (methylated seed oil, Merge[(R)]) was included in the spray mixture, together with ammonium sulfate fertilizer.  Samples of mature canola dried seed were harvested at a 2-3 day PHI.  At two trials, additional treated samples were collected at 0, 1, 7, and 10 days after treatment, in addition to the targeted 3+-1 day PHI, to evaluate residue decline.

The results from these trials on canola show that after a single harvest aid/desiccant broadcast application of saflufenacil applied at 0.045 lb ai/A, maximum saflufenacil residues were 0.48 ppm in/on canola dried seed samples harvested at a 2-3 day PHI; the metabolite M800H11 and M800H35 residues in/on canola seed samples were below the LOQ (<0.01 ppm each), with the exception of five isolated samples that bore M800H11 residues at 0.01-0.05 ppm (Table 20).  Maximum combined residues of saflufenacil in/on dried seed were <0.55 ppm at the 2-3 day PHI.  The "side-by-side" bridging trials comparing the two formulations (WG vs. SC) demonstrated that there was no substantial difference in residues in canola treated with the two formulations.  The residue decline data indicated that residues of saflufenacil decrease or remained relatively constant at longer PHIs (at one site the residues increased from 0-7 days then decreased slightly from 7-10 days).

Table 20.  Summary of Residue Data from Crop Field Trials with Canola.
Commodity; Treatment
                         Total Applic. Rate (lb ai/A)
                                  [kg ai/ha]
                                  PHI (days)
                                    Analyte
                            Residue Levels (ppm)[1]

                                       n
                                     Min.
                                     Max.
                                    HAFT[2]
                                    Median
                                     Mean
                                   Std. Dev.
Canola, dried seed;

Treatment 2 (WG formulation)
                                  0.044-0.046
                                 [0.049-0.052]
                                      2-3
                                 Saflufenacil
                                      32
                                     0.01
                                     0.33
                                     0.29
                                     0.06
                                     0.08
                                     0.06

                                    M800H11

                                   <0.01
                                     0.03
                                     0.02
                                     0.01
                                     0.01
                                     0.00

                                    M800H35

                                   <0.01
                                   <0.01
                                     0.01
                                     0.01
                                     0.01
                                     0.00

                                  Combined[3]

                                   <0.01
                                   <0.35
                                     0.32
                                     0.08
                                     0.10
                                     0.07
Canola, dried seed;

Treatment 3 (SC formulation)
                                  0.041-0.046
                                 [0.046-0.052]
                                       3
                                 Saflufenacil
                                       6
                                     0.02
                                     0.48
                                     0.43
                                     0.05
                                     0.17
                                     0.21

                                    M800H11

                                   <0.01
                                     0.05
                                     0.05
                                     0.01
                                     0.02
                                     0.02

                                    M800H35

                                   <0.01
                                   <0.01
                                     0.01
                                     0.01
                                     0.01
                                     0.00

                                  Combined[3]

                                   <0.04
                                   <0.55
                                     0.49
                                     0.07
                                     0.20
                                     0.23
Canola, dried seed;

Both Treatments
                                  0.041-0.046
                                 [0.046-0.052]
                                      2-3
                                 Saflufenacil
                                      38
                                     0.01
                                     0.48
                                     0.43
                                     0.06
                                     0.09
                                     0.10

                                    M800H11

                                   <0.01
                                     0.05
                                     0.05
                                     0.01
                                     0.01
                                     0.01

                                    M800H35

                                   <0.01
                                   <0.01
                                     0.01
                                     0.01
                                     0.01
                                     0.00

                                  Combined[3]

                                   <0.03
                                   <0.55
                                     0.49
                                     0.08
                                     0.12
                                     0.11
[1]  For calculation of the HAFT, median, mean, and standard deviation, seed residue values of  <0.01 ppm (<LOQ) were considered to be 0.01 ppm (LOQ).
[2]  HAFT = highest-average field trial.
[3]  Combined residues of saflufenacil (parent + M800H11 + M800H35).
**  Note that additional samples collected to examine residue decline are not shown; only those samples collected at the targeted 3-day PHI.

Conclusions:  The submitted field trial data for canola seed are adequate to fulfill data requirements.  The number and locations of the trials are in accordance with OPPTS Guideline 860.1500 (Table 21).

Table 21.  Trial Numbers and Geographical Locations.
NAFTA Growing Zones
                                    Canola

                                   Submitted
                                 Requested[1]

                                    Canada
                                     U.S.
2
                                       1

                                       1
5
                                       1
                                       1
                                       2
7
                                       1
                                       1
                                       2
11
                                       2

                                       3
14
                                      11
                                      14

Total
                                     16[2]
                                      16
                                       8
[1]  The requested number and geographic distribution of field trials for canola, according to US EPA OPPTS 860.1500 and PMRA Directive 98-2.
[2]  Three bridging trials (one in Zone 11, two in Zone 14) included side-by-side test plots comparing the WG and SC formulations.

The residue data for canola seed were entered into the Agency's tolerance spreadsheet as specified by the Guidance for Setting Pesticide Tolerances Based on Field Trial Data SOP to determine appropriate tolerance levels; see Appendix II.  In one of the trials, residues were higher at a PHI (7 days) that is greater than the proposed PHI (3 days).  In this case, the higher values were entered into the spreadsheet.  The recommended tolerance for the combined residues of saflufenacil and its metabolites M800H11 and M800H35, expressed as parent equivalents, is 0.45 ppm for rapeseed subgroup 20A.

Sunflower Subgroup 20B, seed

A tolerance of 1.0 ppm is already established for saflufenacil residues in/on sunflower seed, the only representative crop for sunflower subgroup 20B.  As the proposed use directions for oilseeds, sunflower subgroup 20B are identical to the registered use directions for sunflower, the established tolerance of 1.0 ppm for saflufenacil residues in/on sunflower seed can be expanded to sunflower subgroup 20B.

860.1520 Processed Food and Feed

Soybean

DER Reference List	48080905.der.doc

Soybean processing studies were conducted to determine the potential for concentration of residues of saflufenacil in/on the processed fractions of soybean and to determine the magnitude of the residue of saflufenacil in/on AGF samples.

In two field trials conducted during the 2009 growing season NAFTA Growing Zones 2 (GA, one trial) and 5 (IA, one trial), saflufenacil (formulation, BAS 800 00 H; 70% WG) was applied as a single late-season, broadcast foliar application to soybean at a rate of 0.225 lb ai/A (5X).  In addition, a separate plot at the trial located in GA was treated with one application of saflufenacil at 0.045 lb ai /A (1X) to generate AGF samples.  The applications were made in approximately 11-19 gal/A using ground equipment.  An adjuvant (methylated seed oil, Merge[(R)]) was included in the spray mixture, together with ammonium sulfate fertilizer.  Bulk samples of mature soybean dried seed (RAC) were harvested at a 2- or 3-day PHI.

Processing Studies:  The results from these trials show that after one application of saflufenacil to soybean targeting 0.223 lb ai/A/season (5X), combined residues of saflufenacil in two treated soybean seed RAC samples were <0.06 ppm (from GA site) and <0.08 ppm (from IA site), each collected at a 2- or 3-day PHI.  For the individual analytes, parent saflufenacil residues were 0.04 and 0.06 ppm, respectively, and both M800H11 and M800H35 were <LOQ (<0.01 ppm) in/on the two treated soybean seed RAC samples collected 2-3 days after treatment.

The two exaggerated-rate treated, bulk seed RAC samples, described above, were separately processed using simulated commercial processing procedures into meal, hulls, and refined oil, the currently EPA-regulated commodities of soybean.  In addition, flour, soy milk, and tofu samples were collected for analysis.  A comparison of the residues in the RAC with those in each processed fraction indicates that the combined residues of saflufenacil concentrate in hulls (5.0-6.9X, average processing factor of 6.0x), but do not concentrate appreciably (on average) in meal, flour, refined oil, soy milk, or tofu.  The reported processing factor for hulls does not exceed the theoretical concentration factor.  According to Table 3 of OPPTS 860.1520, the theoretical concentration factor based on component separation is 11.3X for soybean hulls.

AGFs:  Combined residues were <4.52 ppm in/on one treated AGF sample derived from a seed sample treated with a single broadcast foliar application of saflufenacil targeting 0.045 lb ai/A (0.50 kg ai/ha/season, Treatment 2) and harvested at a 3-day PHI.  Residues of parent were 4.50 ppm and residues of the metabolites M800H11 and M800H35 were each <0.01 ppm (<LOQ) in/on the treated AGF sample.  Total residues of saflufenacil concentrate in AGF by a factor of 150X.

The residue samples were stored frozen (<-5ºC) for a maximum of 189 days (6.2 months), from harvest to extraction for analysis, for soybean seed RAC samples, and 32 days (1.1 months), from fraction collection to extraction for analysis, for AGFs and processed commodity samples.  Adequate storage stability data are available to support the storage conditions and durations for the samples in the present study.

Conclusions:  The submitted soybean processing data are adequate to fulfill data requirements.  Based on the average processing factors of 6X and 150X and a HAFT residue of 0.07 ppm for soybean seed, the processing data will support a tolerances of 0.50 ppm and 10 ppm for soybean hulls and AGFs, respectively.  Separate tolerances are not required for meal or refined oil.

Cotton

DER Reference List	48080906.de2.doc

In two field trials conducted during the 2009 growing season in NAFT) Growing Zones 2 (GA, one trial) and 8 (TX, one trial), saflufenacil (formulation, BAS 800 00 H; 70% WG) was applied as a single late-season, broadcast application to cotton at a rate of 0.225-0.234 lb ai/A (5X).  The applications were made using typical ground boom equipment with a tank mix spray volume of 32.5-40.7 gal/A for thorough coverage of the plot area.  All applications were made using water as the carrier.  In addition to the test substance, the tank mix for the GA trial contained 1% (v/v) MSO and 15-17 lbs/100 gallons of AMS and the tank mix for the TX trial contained 1% (v/v) MSO only in the final spray mixture.  Undelinted cottonseed samples were mechanically harvested 5 days after application using either a cotton picker (GA trial) or cotton stripper (TX trial).

The results for the cotton processed fractions from the two field trials show that after a single application of BAS 800 00 H at a target rate of 0.225 lb ai/A with a target 5-day PHI, the individual residues of saflufenacil, M800H11, and M800H035 ranged from <LOQ (0.01 ppm) to 0.08 ppm for undelinted seed.  Total residues were <0.04 or <0.10 ppm.

For processed fractions of hulls, meal, crude oil, and refined oil, individual residues ranged from <LOQ (0.01 ppm) to 0.04 ppm.  Total residues ranged from <0.03 to <0.06 ppm in all processed fractions [combined residues of saflufenacil (parent + M800H11 + M800H35) are expressed as parent equivalents].  A comparison of the residues in the seed with those in each processed fraction indicates that residues of saflufenacil do not concentrate in cotton processed commodities (refined oil, crude oil, meal, and hulls).

Conclusions:  The submitted cotton processing data are adequate to fulfill data requirements.  As residues of saflufenacil do not concentrate in cotton processed commodities, separate tolerances for refined oil, meal, or hulls will not be required.

Canola

DER Reference List	48135202.der.doc

Canola processing studies were conducted to determine the potential for concentration of residues of saflufenacil in the processed fractions of canola (rapeseed, canola varieties only, as the representative crop of Oilseeds Rapeseed Subgroup 20A).  In two field trials conducted during the 2009 growing season in NAFTA Growing Zones 5 (ND, one trial) and 11 (ID, one trial), saflufenacil (formulation, BAS 800 00 H; 70% WG) was applied as a single late-season, broadcast application to canola at a rate of 0.220-0.234 lb ai/A (5X).  The applications were made in approximately 14-23 gal/A using ground equipment.  An adjuvant (MSO, Merge[(R)]) was included in the spray mixture, together with ammonium sulfate fertilizer.  Bulk samples of mature canola dried seed (RAC) were harvested at a 3-day PHI.  One untreated and one treated bulk seed sample from each trial site were later processed into canola processed fractions.

The results from these trials show that after one application of saflufenacil to canola targeting 0.225 lb ai/A/season, parent saflufenacil residues in/on two treated canola seed RAC samples were 0.04 ppm (from ND site, mean of two replicate subsamples A and B) and 1.73 ppm (from ID site, mean of two replicate subsamples A and B), each collected at a 3-day PHI; M800H11 and M800H35 residues were non-quantifiable (<0.01 ppm each) in the treated canola seed samples collected at a 3-day PHI and in all processed fractions collected during the study.  The two treated bulk seed RAC samples, described above, bearing quantifiable saflufenacil residues were separately processed using simulated commercial processing procedures into meal and refined oil.  A comparison of the residues in the seed with those in each processed fraction indicates that residues of saflufenacil do not concentrate in canola processed commodities (meal and refined oil).

Conclusions:  The submitted canola processing data are adequate to fulfill data requirements.  As residues of saflufenacil do not concentrate in canola processed commodities, separate tolerances for residues in meal or oil will not be required.

860.1650 Submittal of Analytical Reference Standards

Analytical standards of saflufenacil, M800H11, and M800H35 are currently available in the National Pesticide Standards Repository [source:  personal communication with T. Cole of ACL/BEAD, 10/28/10].  However, since the standards for M800H11 and M800H35 expired on 10/1/10, the petitioner is requested to provide an updated COA or a new supply to the Repository.  The reference standards should be sent to the ACL, which is located at Fort Meade, to the attention of Theresa Cole at the following address:

	USEPA
	National Pesticide Standards Repository/Analytical Chemistry Branch/OPP
	701 Mapes Road
	Fort George G. Meade, MD  20755-5350
(Note that the mail will be returned if the extended zip code is not used.)

860.1850 Confined Accumulation in Rotational Crops

The metabolism of saflufenacil in rotational crops was investigated using lettuce, radish and wheat after a single spray application of the test substance in the EC formulation BAS 800 UBH at a nominal application rate of 0.134 lbs. ai/A (1X the pre-emergent rate, 0.67X the post-emergent rate).
Saflufenacil in rotational crops was metabolized by:  a) stepwise degradation (N-dealkylation) of the N-methyl-N-isopropyl group to NH2, forming a sulfonamide group; b) a N-demethylation at the uracil ring; and c) a hydrolytic opening of the uracil ring generating a urea side chain.  The metabolite M800H35 was identified as a metabolite in which the methyl group of the N-methyl-N-isopropyl unit was lost and the uracil ring was cleaved generating a urea side chain.  Metabolites M800H01 and M800H05 resulted from stepwise demethylation and dealkylation of the N-methyl-N-isopropyl group to NH2.  Metabolite M800H11 was formed by demethylation of the methyl group of the N-methyl-N-isopropyl unit and demethylation of the N-methyl group in the uracil ring.  M800H10 was identified as a derivative of saflufenacil in which the N-isopropyl group was lost and the uracil ring was demethylated.  The metabolite TFA was only found in the uracil label.  Based on the quantitative difference in TRR and the comparison of the metabolite patterns from both labels, the study authors suggested that the metabolite TFA originate from an uptake of the metabolite or a precursor molecule from the soil into the plants.

Conclusions:  The submitted confined rotational crop study is adequate to satisfy data requirements.  The metabolism of saflufenacil in rotational crops appears to be consistent with the pathway observed in the plant metabolism studies.  The HED ROCKS determined that residues of concern for rotational crops consist of saflufenacil, M800H11, and M800H35 (Memo, B. Daiss, 1/6/09; D359645).

860.1900 Field Accumulation in Rotational Crops

The field rotational study was conducted in NAFTA Growing Regions 2 (3 trials in GA) and 10 (three trials in CA).  Saflufenacil (70% WG, formulation code BAS 800 00 H) was applied as a single pre-emergence application to the soil, after planting of the primary crop wheat, at 0.132-0.137 lb ai/A (1X the pre-emergent rate, 0.67X the post-emergent rate).  The representative rotational crops radish, lettuce, and wheat (spring and winter) were grown at PBIs of 4 months (119-125 days), 6 months (180-183 days), and 9 months (270-274 days).

Residues of saflufenacil and its metabolites M800H11 and M800H35 were all below the LOQ in rotated wheat (<0.025 ppm for wheat forage, hay, and straw, <0.01 ppm for grain), radish (<0.01 ppm, top and roots), and lettuce (<0.01 ppm, leaves).

Conclusions:  The submitted field rotational crop data are adequate to satisfy data requirements.  The available data indicate that residues of saflufenacil and its metabolites M800H11 and M800H35 were each <LOQ in/on all rotational crop matrices at a 120-day PBI.  These data support the labeled rotational crop restriction of 4 months for all non-labeled crops.  Unless the petitioner requests PBIs shorter than 120 days, no additional data are required, and tolerances for inadvertent residues in/on rotational crops need not be established in conjunction with the currently proposed uses.

860.1550 Proposed Tolerances

A summary of the recommended tolerances for the current petition are listed in Table 22.  The petitioner should submit a revised section F reflecting the recommended tolerances and commodity definitions presented in Table 22.

There are no Codex maximum residue limits (MRLs) established for residues of saflufenacil and its metabolites in crop or livestock commodities.  Canadian MRLs are established for vegetable, legume, subgroup 6c; cotton, undelinted seed; and livestock commodities, all at levels lower than those recommended to support the current action.  Canada is currently in the process of reviewing the proposed harvest-aid uses use of saflufenacil.  EPA and Canadian tolerance/MRL recommendations will be harmonized as part of the joint-review process.

The Agency's Guidance for Setting Pesticide Tolerances Based on Field Trial Data was utilized for determining appropriate tolerance levels for sunflower seed; see Appendix II for tolerance calculations.  A detailed discussion of the assessment of livestock commodity tolerances is presented in the "860.1480 Meat, Milk, Poultry, and Eggs" section of this Summary Document.

Table 22.  Tolerance Summary for Saflufenacil.

Commodity
                           Proposed Tolerance (ppm)
                        HED-Recommended Tolerance (ppm)
Correct Commodity Definition/Comments
Oilseeds, Cottonseed Subgroup 20C, gin byproducts
                                      3.5
                                     0.45
Cotton, gin byproducts
Oilseeds, Cottonseed Subgroup 20C, undelinted seed
                                      0.2
                                     0.20
Cottonseed Subgroup 20C
Oilseeds, Sunflower Subgroup 20B, seed
                                      1.0
                                      1.0
Sunflower Subgroup 20B
Pea, vines
                                      8.0
                                      17
Pea, hay
Soybean, aspirated grain fractions
                                     4.52
                                      10
Grain, aspirated fractions
Soybean, hulls
                                     0.42
                                     0.50

Soybean, seed
                                      0.1
                                     0.10

Vegetable, Legume, Subgroup 6C, beans, dry
                                      0.5
                                     0.30
Pea and bean, dried shelled, except soybean, subgroup 6C
Vegetable, Legume, Subgroup 6C, peas, dry
                                      0.1

Oilseeds, Rapeseed Subgroup 20A, seed
                                      0.8
                                     0.45
Rapeseed Subgroup 20A
Cattle, liver
                                       -
                                      2.5

Cattle, meat byproducts, except liver
                                       -
                                     0.05

Goat, liver
                                       -
                                      2.5

Goat, meat byproducts, except liver
                                       -
                                     0.05

Sheep, liver
                                       -
                                      2.5

Sheep, meat byproducts, except liver
                                       -
                                     0.05

Horse, liver
                                       -
                                      2.5

Horse, meat byproducts, except liver
                                       -
                                     0.05

Note:  In conjunction with establishing these tolerances, the existing tolerance for "Vegetable, foliage of legume, group 7" should be modified to "Vegetable, foliage of legume, group 7 (except pea hay)"; the existing tolerance for "Vegetable, legume, group 6" should be replaced with "Vegetable, legume, edible podded, subgroup 6A" plus "Pea and bean, succulent shelled, subgroup 6B"; and the existing tolerances for "Sunflower, seed" and "Cotton, undelinted seed" should be deleted.

Attachments:
International Residue Limit Status (IRLS) sheet.
Appendix I - Chemical Name and Structure Table.
Appendix II - Tolerance Assessment Calculations.

cc:  G. Kramer (RAB1)
RDI:  RAB1 Chemists (12/1/10)
G.F. Kramer:S10957:PY-S:(703)305-5079:7509P:RAB1IRLS Sheet.

              Saflufenacil (118203; Date of Request:  11/04/2010)
Summary of U.S. and International Tolerances and Maximum Residue Limits
Residue Definition:
U.S.
Canada
Mexico[2]
Codex
40 CFR 180.649:
Plant:  saflufenacil, including its metabolites and degradates, sum of saflufenacil, 2-chloro-5-[3,6-dihydro-3-methyl-2,6-dioxo-4-(trifluoromethyl)-1(2H)-pyrimidinyl]-4-fluoro-N-[[methyl(1-methylethyl)amino]sulfonyl]benzamide, and its metabolites N-[2-chloro-5-(2,6-dioxo-4-(trifluoromethyl)-3,6-dihydro-1(2H)-pyrimidinyl)-4-fluorobenzoyl]-N'-isopropylsulfamide and N-[4-chloro-2-fluoro-5-({[(isopropylamino)sulfonyl]amino}carbonyl)phenyl]urea, calculated as the stoichiometric equivalent of saflufenacil
Livestock:  saflufenacil