  SEQ CHAPTER \h \r 1

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C.  20460

OFFICE OF

PREVENTION, PESTICIDES, AND

TOXIC SUBSTANCES

	PC Code: 118203

	DP Barcode: 349860

MEMORANDUM	April 15, 2009

SUBJECT:	Tiered Drinking Water Exposure Assessment for Saflufenacil (Section 3 New Chemical Uses on Agricultural and Non-agricultural Areas).

TO:	Kathryn Montague, Product Manager

	Joanne Miller, Team Leader

	Herbicide Branch, RM Team 23

	Registration Division (RD) (7505P)

	George F. Kramer, Ph.D., Chemist

	Risk Assessment Branch I

	Health Effects Division (7509P)

FROM:	Greg Orrick, Environmental Scientist

	Environmental Risk Branch IV

	Environmental Fate and Effects Division (7507P)

THROUGH:	R. David Jones, Ph.D., Senior Agronomist

N′-{2-chloro-4-fluoro-5-[1,2,3,6-tetrahydro-3-methyl-2,6-dioxo-4-(trif luoromethyl)pyrimidin-1-yl]benzoyl}-N-isopropyl-N-methylsulfamide] in surface water and in ground water in support of human health risk assessment.  Screening EDWCs (Table 1) of saflufenacil were generated with FIRST for surface water and with PRZM GW for ground water.  Modeled application rates represent the maximum use patterns of five proposed end-use labels with selected uses on row crops, orchard trees, vineyards, tree plantations, and non-agricultural areas (EPA Reg. Numbers pending).  Remaining model input parameters were chosen according to current guidance (USEPA, 2002).  EDWCs reflect exposure to saflufenacil and all degradates of concern in drinking water (USEPA, 2009).  If the screening Estimated Drinking Water Concentrations (EDWC) listed in this memo result in dietary risk exceedances, contact Greg Orrick<PHONE_NUMBER>) of Environmental Risk Branch IV (7507P) to request a refined drinking water exposure assessment.

1-in-10-year Peak Exposure (μg/L)	1-in-10-year Annual Mean Exposure (μg/L)

Surface water (Tier I: FIRST)	37.3	23.8

Ground water (Tier II: PRZM GW)	180	173

	Saflufenacil is a new contact and residual herbicide in the uracil class of compounds that is designed for broadleaf weed control.  The compound is nonvolatile and is increasingly soluble in water with increasing pH.  Saflufenacil weakly sorbs to soil (i.e., is mobile to highly mobile in soil) and may readily move into surface water through runoff and/or present a ground water concern, depending on the permeability of the soil.  Low application rates may limit the extent to which the compound runs off into surface water or leaches into ground water.

	Saflufenacil may be moderately persistent in some environments, such as acidic to neutral ground water, and may readily degrade in other environments, such as surficial and alkaline water bodies.  The compound dissipates in the environment through chemical and microbially-influenced degradation and by leaching and is expected to degrade moderately in aerobic soil (half-life of 1-5 weeks), less quickly in acidic to neutral water bodies (half-life of 4-10 weeks), and more quickly in alkaline water bodies (half-life of <1 week).

	Saflufenacil has fourteen major degradates that were isolated in submitted environmental fate studies.  Seven of them, M01, M02, M07, M08, M15, M22, and product 8, are included with the parent as residues of concern.  Due to the structural similarity of these degradates to the parent and a lack of toxicity data, they are assumed to have equivalent toxicity to the parent (USEPA, 2009).  Exposure estimates in this assessment reflect total residues of concern (TRC).

PROBLEM FORMULATION

	This drinking water assessment uses environmental modeling to provide estimates of surface water and ground water concentrations in drinking water source water (pre-treatment) resulting from saflufenacil use on vulnerable sites.  Estimates reflect drinking water exposure to saflufenacil residues of concern in drinking water, which include the parent compound and its degradates M800H01, M800H02, M800H07, M800H08, M800H15, M800H22, and an unidentified “Product 8” (chemical names and structures in Table I.1, Appendix I), on a per molar basis (USEPA, 2009).  Primary routes of transport to source water include runoff, erosion, leaching, and spray drift.  Exposure in surface water from the proposed saflufenacil uses due to runoff, erosion, and spray drift was assessed with the Tier I screening model, FIRST.  Exposure in ground water due to leaching was assessed with the screening ground water models SCI-GROW (a Tier I model) and PRZM GW (a Tier II model).

ANALYSIS

Use Characterization

	Saflufenacil, also known as BAS 800 H, is a new contact and residual herbicide in the uracil class of compounds that is absorbed by roots and foliage, according to the proposed end-use product label BAS 800 04H FiRoCrop Herbicide.  The compound belongs to the mode-of-action Group 14/Group E, meaning that it inhibits protoporphyrinogen-oxidase (PPO), resulting in membrane damage under light and, ultimately, plant death.  Saflufenacil is proposed for use on broadleaf weeds via pre-plant and pre-emergence applications to cereal small grains, corn, chickpeas, cotton, edible beans, edible peas, lentils, lupine, sorghum, soybeans, and sunflowers; via post-emergence applications to fruit trees, nut trees, and vineyards; and via applications to fallow croplands and non-agricultural areas, including pine plantations, rights-of-way, bare ground, and Christmas tree plantations.  Saflufenacil is also proposed for use as a desiccant and/or defoliant on sunflower.

en™; 12.27% a.i.), an emulsifiable concentrate (EC) for non-agricultural uses.  Table 2 lists the proposed use patterns and maximum application rates on the proposed labels for these five end use formulations.

	The proposed maximum single and annual application rate for saflufenacil is the same, at 0.356 lbs a.i./A  on non-agricultural areas (BAS 800 02H; Sharpen™), which characterizes the maximum use pattern of saflufenacil for this national-level, screening drinking water exposure assessment.  BAS 800 04H (FiRoCrop) and BAS 800 01H (TNV) have a proposed maximum annual application rate of 0.13 lbs a.i./A for selected agricultural crop, orchard, and fallow land uses.  The multi-active ingredient products, BAS 804 00H (LegVeg) and BAS 781 02H, have lower proposed maximum annual application rates for labeled uses, but include directions not to exceed an annual rate of 0.134 lbs saflufenacil per acre from all sources of the chemical.

Table 2.  Proposed use patterns for saflufenacil end use products.

Product Label	Active Ingredient (%)	Use	Maximum Single Application Rate

(lbs saflufenacil/A)	Maximum Annual Application Rate (lbs saflufenacil/A)	Additional Application Directions

BAS 800 04H (FiRoCrop)	Saflufenacil (29.74%)	Fallow, post-harvest	0.13 0.13	Equipment: ground or aerial.

Field corna, sweet cornb, and popcorn	0.13	0.13	Application timing: 14-30 days prior to planting (incorporated or surface) or pre-emergence.

Application rates 15-30 days prior to planting vary by soil texture and organic matter (higher rates on finer soils and soils with higher organic matter); not so 14 days prior to planting.

Equipment: ground or aerial.

Sorghum

	Cotton	0.045	0.045	Application timing: prior to accumulation of 1-inch of rainfall or irrigation to occur 21 days prior to planting.

Equipment: ground or aerial.

Legume vegetablesc	0.089	0.089	Application timing: pre-plant or pre-emergence (pre-plant only for lentils).

Equipment: ground or aerial.

Soybeans (tolerant)

	Small grainsd	0.13	0.13	Application timing: pre-plant or pre-emergence (dormant or during and/or after spring green up for winter wheat at 0.045 lbs a.i./A).

Equipment: ground or aerial.

Sunflower	0.045	0.089	Maximum number of applications per year: 2 (interval not stated).

Application timing: at least 7 days prior to harvest (for desiccation).

Equipment: ground or aerial.

BAS 804 00H (LegVeg)	Saflufenacil (17.80%) and Imazethapyr (50.20%) Clearfield® corn	0.023	0.023	Maximum annual app. rate from all sources: 0.134 lbs saflufenacil/A for Clearfield® corn; 0.089 lbs saflufenacil/A for legume vegetables and soybeans.

Application timing: pre-plant or pre-emergence (pre-emergence only for Clearfield® corn).

Equipment: ground or aerial.

Legume vegetables (per region)e	0.017

(Southern peas only: 0.023)	0.017

(Southern peas only: 0.023)

	Soybeans	0.023	0.023

	BAS 781 02H	Saflufenacil (6.24%) and Dimethenamid-P (55.04%)	Field corna, sweet cornb, and popcorn	0.11	0.11	Maximum annual app. rate from all sources: 0.134 lbs saflufenacil/A.

Application timing: 14-30 days prior to planting (incorporated or surface) or pre-emergence.

Application rates 15-30 days prior to planting vary by soil texture and organic matter (higher rates on finer soils and soils with higher organic matter); not so 14 days prior to planting.

Equipment: ground, aerial, or chemigation.

Grain sorghum

	BAS 800 01H (TNV)	Saflufenacil (70%)	Citrus fruit, pome fruit, stone fruit, tree nuts	0.045	0.13	Maximum number of applications per year: 3 (at least 21 days apart).

Application timing: post-emergence.

Equipment: ground.

Grape vines	0.022	0.066

	BAS 800 02H (Sharpen™)	Saflufenacil (12.27%)	Christmas tree plantations	0.356	0.356	Application timing: post-emergence for Christmas tree plantations; pre-plant for conifer and hardwood plantations; no directions for non-agricultural areas.

Equipment: ground or aerial.

Conifer and hardwood plantations

	Non-agricultural areas

	a  Field corn includes conventional or herbicide-tolerant field corn grown for grain, seed, or silage.

b  Sweet corn does not include sweet corn grown for seed.

c  Legume vegetables include chickpeas, selected edible beans, selected edible peas, and lentils.

d  Small grains include wheat, barley, canaryseed, oats, millet, rye, and triticale.

e  Legume vegetables (per region) includes lentils, white lupins, chickpeas, dry edible peas, English peas, and Southern peas in the states east of and including North Dakota, South Dakota, Wyoming, Colorado, and New Mexico, except the states east of and including Vermont, Massachusetts, and Connecticut; succulent peas, dry edible peas, lentils, and chickpeas in Idaho, Montana, Nevada, Oregon, Utah, and Washington; and chickpeas in Arizona and California.

Fate and Transport Characterization

	Saflufenacil [N’-[2-chloro-4-fluoro-5-(3-methyl-2,6-dioxo-4-(trifluoromethyl)-3,6-d ihydro-1(2H)-pyrimidinyl)benzoyl]-N-isopropyl-N-methylsulfamide] is nonvolatile, hydrophilic, and mobile to highly mobile in soil, as dissolved in surface water runoff and/or ground water.  The compound dissipates in the environment through chemical and microbially-influenced degradation and by leaching and is expected to degrade moderately in aerobic soil (half-life of 1-5 weeks), less quickly in acidic to neutral water bodies (half-life of 4-10 weeks), and more quickly in alkaline water bodies (half-life of <1 week).  While saflufenacil may readily degrade in surficial and alkaline water bodies, the compound may be moderately persistent in acidic to neutral ground water.  Table 3 summarizes the submitted environmental fate data for saflufenacil.

Table 3.  General chemical properties and environmental fate parameters of saflufenacil.

Parameter	Value	Source

Selected Physical/Chemical Parameters

Molecular mass	500.86	MRID 47127817

Vapor pressure (extrapolated)	20°C: 3.4 x 10-17 torr

25°C: 1.5 x 10-16 torr	MRID 47127821

Water solubility (20(C)	pH 4: 14 mg/L

pH 5: 25 mg/L

pH 7: 2,100 mg/L

pH 9: ndA	MRID 47127819

Henry’s Law Constant (25°C)	4.01 x10-20 atm-m3/mol	MRID 47127822

pKa	4.41	MRID 47127817

Log octanol-to-water partition coefficient

(log KOW at pH <4.41)	2.56	MRID 47127818

Persistence

Hydrolysis half-life (25(C)	pH 5: Stable

pH 7: 248 d

pH 9: 4.93 d	MRID 47127823

Aqueous photolysis half-life (22(C)	56 d (buffer; pH 5)

22 d (pond water; pH 7.1)	MRID 47699901

Soil photolysis half-life (22(C)	66 d (12-hr light/day)

84 d (continuous irradiation)	MRID 47127825

Aerobic soil metabolism half-life (25(C)	9.3 d (silt loam; pH 6.1)

23.3 d (loamy sand; pH 5.9)

26.2 d (silty clay loam; pH 5.5)

32.1 d (sandy loam; pH 6.8)	MRID 47445901

Anaerobic soil metabolism half-life (25(C)	[217 d]B (loamy sand; pH 5.0-6.0)	MRID 47611201

Anaerobic aquatic metabolism half-life (25(C)	[29.4 d]B (pH 5.5-8.5) MRID 47127828

Aerobic aquatic metabolism half-life (25(C)	70.7 d (dark; pH 5.8-6.7)

3.6 d (12-hr light/day; pH 6.1-8.0)	MRID 47127827

Mobility

Range of Freundlich organic carbon normalized partition coefficients (KFOC)	9.3–55 L/kgOC (n=6)	MRID 47127829

Field Dissipation

Terrestrial field dissipation half-life (Soil series; texture)		Georgia: 10.7 d (Fuquay; sandy loam)	MRID 47127834

		Arkansas:

	Illinois:

	Manitoba:	6.25 d (Commerce; silt loam)

11.1 d (Cisne-Huey Complex; silt loam)

35.5 d (Neuhorst; loam)	MRID 47127835

		Washington:

	Ontario:

	California:	1.4–4.6 d (Quincy; loamy sand)

7.3–23.6 d (Brant; loam)

13.0–32.2 d (San Joaquin; clay loam)	MRID 47127836

A  “nd” means not determined due to degradation.

B  Half-lives are highly uncertain.

Transport and Mobility

	Saflufenacil will not significantly volatilize due to a low vapor pressure (1.5 x 10-16 torr at 25°C; MRID 47127821) and a solubility in water that increases with increasing pH (14 mg/L (pH 4) to 2.1 x 103 mg/L (pH 7) at 20°C; MRID 47127819).  Saflufenacil’s solubility in water could not be determined at pH 9 due to hydrolysis.  The range of solubility in water across pH values indicates that the compound exhibits acid/base behavior.

	Saflufenacil is expected to be ionic at pH values above its pKa of 4.41 (MRID 47127817).  Dissociation was not determined above pH 5.28.  Given the similarity in water solubility at pH 4 (14 mg/L) and pH 5 (25 mg/L) and the substantially higher water solubility at pH 7 (2.1 x 103 mg/L), it is uncertain whether saflufenacil has an additional dissociation constant above pH 5 and whether the water solubility value at pH 5 is accurate.  Acid/base behavior with respect to octanol-to-water partitioning was not studied, as the log KOW (2.56) was only determined for the neutral species at an unreported pH value less than the compound’s pKa of 4.41 (MRID 47127818).

	At environmental pH values (initial soil pH values of 5.5-8.0), saflufenacil weakly sorbs to soil (MRID 47127829).  However, the compound displays affinity to organic matter (e.g., the coefficient of variation (CV) across six soils for KFOC (60%) is less than that for KF (97%)).  According to the FAO soil mobility classification scheme, saflufenacil is mobile to highly mobile in soil (KFOC of 9.3 to 55 L/kgOC) and may readily move into surface water through runoff and/or to ground water, depending on the permeability of the soil (USEPA, 2006).

Degradation

	Saflufenacil degrades in the environment through chemical and microbially-influenced processes, some of which are not well understood.  Hydrolysis of saflufenacil is pH-dependent, as the compound degrades readily in alkaline environments (half-life of 5 days at pH 9) and persists in acidic to neutral conditions (stable at pH 5; half-life of 248 days at pH 7; MRID 47127823).  Major hydrolysis degradates include M04, M07, M15, and M33 (chemical names structures, and maximum formed amounts of all degradates are listed in Table I.1, Appendix I).

	The compound is moderately photolyzed in clear, near-surface water (half-lives of 56 days in a sterile pH 5 buffer and 22 days in unsterile pH 7.1 pond water; MRID 47699901) and on soil (half-lives of 66 days under 12 hours of irradiation per day and 84 days under continuous irradiation followed by conversion to a value reflecting 12 hours of irradiation per day; MRID 47127825).  No major degradates were formed in the sterile pH 5 buffer.  M29, M33, and an unidentified compound were major degradates in the pond water.  Major photolysis degradates on soil included M15 under 12 hours of light per day and Product 8 under continuous irradiation, an unidentified compound that degraded to M01 during handling and analysis.  These degradates were not formed in major amounts in the dark, where M07 and M08 were.

	In aerobic soil, saflufenacil degraded with a half-life ranging from 9.3 to 32 days in four soils (pH 5.5 to 6.8; MRID 47445901).  The major degradates were M01, M02, M07, M08, M22, M26, and M31, which were up to 10%, 31%, 52%, 66%, 16%, 18%, and 18% of the applied, respectively.  M02, M08, and M22 were major degradates in all four soils.  M26 was a major degradate in only the silt loam soil, in which saflufenacil degraded the quickest.  A mixture of volatile compounds (M26, M29, and carbon dioxide) also accounted for up to 16.5% of the applied radioactivity in the silt loam test system; however, their individual proportions were not determined.  It is unusual that the most prominent degradate (M08) in this aerobic study was a reduction product.  Its presence is likely the result of enzymatic (i.e., uracil hydrogenase) activity.

	In anaerobic soil, saflufenacil degraded with a half-life of 217 days in one soil (pH 5.0-6.0; MRID 47611201).  Major degradates included M01, M02, and M08, which were a maximum of 14%, 24%, and 25% of the applied, respectively.  Results of the study are highly uncertain because anaerobic conditions were marginal; the mean redox potential in the post-flood water was -34 ( 88 mV (n=28).

	In anaerobic aquatic systems, saflufenacil degraded with a half-life of 29.4 days in one system (pH 5.5-8.5).  Major degradates included M07, M15, M29, M33, and 1,1,1-trifluoro-2-propanol, which were a maximum of 71%, 16%, 11%, 16%, and 19% of the applied, respectively, in the total system.  Results of the study are highly uncertain because anaerobic conditions in the water layer, where the majority of the applied partitioned, were marginal; redox potential was not measured in the water layer (it was reducing to strongly reducing in the sediment layer) and dissolved oxygen in the water layer was up to 1.7 mg/L.  Additional uncertainty was due to a declining material balance for the uracil-labeled system and significant dissipation (35-50% of the applied) of saflufenacil in both systems between the 30 and 62 day sampling intervals, when dissolved oxygen appeared to be most elevated.  Due to the detection of major and minor degradation products in this study that were not detected in the aerobic aquatic metabolism or hydrolysis studies, it appears that conditions were partially anaerobic.

	In aerobic aquatic systems, saflufenacil degraded with a half-life of 70.7 days at pH 5.8-6.7 (MRID 47127827).  The major transformation products were M07, M29, M33, and carbon dioxide, which were a maximum of 23%, 8.8%, 23%, and 11% of the applied, respectively, in the total system.  Results of the study are uncertain because dissolved oxygen concentrations (2.7-5.5 mg/L, corresponding to ~33-65% saturation at 25°C) were less than the typical range (7-10 mg/L) and recoveries of the uracil-labeled systems were highly variable (76% to 114%).  Regardless, redox potentials in the water layer (ranging +150 to +410 mV) indicate that the test system was aerobic.  It is not understood why saflufenacil appears to degrade with shorter half-lives in aerobic terrestrial and anaerobic aquatic systems (9.3 to 32 days) than in anaerobic terrestrial and aerobic aquatic systems (half-lives of 71 to 217 days).

Field Studies

	Three terrestrial field dissipation studies were conducted for saflufenacil using five sites in the United States and two sites in Canada, each with three bare ground plots that had <1% slope and no runoff collection equipment.  One study was conducted on a sandy loam soil (Fuquay soil series) in Georgia (MRID 47128234).  Saflufenacil was broadcast once at a target application rate of 0.40 kg a.i./ha (0.357 lb a.i./A), which is the proposed maximum application rate (for use on tree plantations and non-agricultural areas).  Total water input was 122% of the historical average.  Soil samples (0-120 cm depth) were collected through 451 days after treatment.  The mean zero-time concentration of saflufenacil in the 0-7.5 cm soil depth was 0.19 ppm, which was 57% of the theoretical.  Saflufenacil dissipated in the whole soil profile with a half-life of 11 days.  The compound was detected above the limit of quantitation (LOQ = 0.01 ppm or 3% of the theoretical zero-time concentration) at a maximum depth of 45-60 cm, 32 days after treatment.

	For each study, test sites were analyzed for M01, M02, M07, M08, M15, and M22.  In the Georgia sandy loam, M08, M01, and M02 were detected above the LOQ (detections between the LOD and LOQ were not reported).  M08 was detected in the 0-7.5 cm and 7.5-15 cm soil depths at maximum concentrations of 0.04 ppm on the day of treatment (21% of the initial soil concentration of saflufenacil) and 0.05 ppm at 6 days after treatment (26% of the initial soil concentration of saflufenacil), respectively, and was detected above the LOQ at a maximum depth of 90-105 cm at 46 and 75 days after treatment.  M01 was detected in the 0-7.5 cm soil depth at a maximum concentration of 0.02 ppm (10.8% of the initial soil concentration of saflufenacil) from 0-8 days after treatment and was not detected above the LOQ below the 7.5-15 cm depth.  M02 was detected in the 0-7.5 cm soil depth at a maximum concentration of 0.01 ppm (5.4% of the initial soil concentration of saflufenacil) at 0, 1, 2, and 6 days after treatment and was not detected above the LOQ in soil below the 0-7.5 cm depth.

	A second study was conducted on silt loam soils in Arkansas (Commerce soil series) and Illinois (Cisne-Huey Complex soil series) and on a loam soil (Neuhorst soil series) in Manitoba (MRID 47128235).  Saflufenacil was broadcast once at a target application rate of 0.15 kg a.i./ha (0.134 lb a.i./A), which is the proposed maximum application rate for use on corn, sorghum, small grain crops, and fallow land.  Total water input at these sites was 97% to 108% of the historical average.  Soil samples (0-120 cm depth) were collected through 360 days after treatment.  The mean zero-time concentrations of saflufenacil in the 0-7.5 cm soil depth of each site were 0.16 ppm, 0.14 ppm, and 0.09 ppm, which were 101%, 107%, and 48% of the theoretical, respectively.  Saflufenacil dissipated in the whole soil profile of each site with respective half-lives of 6.25, 11.1, and 35.5 days.  The compound was detected above the limit of quantitation (LOQ = 0.01 ppm or 5.3% to 7.6% of the theoretical zero-time concentration) at a maximum depth of 7.5-15 cm in the Arkansas silt loam soil (2 and 6-8 days after treatment), a maximum depth of 0-7.5 cm in the Illinois silt loam soil (0-45 days after treatment), and a maximum depth of 15-30 cm in the Manitoba loam soil (6 days after treatment).

	In the Arkansas silt loam, M08 was the only degradate detected above the LOQ.  In the 0-7.5 cm soil depth, M08 was detected at a maximum concentration of 0.03 ppm (19% of the initial soil concentration of saflufenacil) at 75 to 90 days after treatment and was not detected above the LOQ below this depth.  In the Illinois silt loam, M08 was the only degradate detected above the LOQ.  In the 0-7.5 cm soil depth, M08 was detected at a maximum concentration of 0.03 ppm (21% of the initial soil concentration of saflufenacil) at 30 to 45 days after treatment and was not detected above the LOQ below the 7.5-15 cm depth.  In the Manitoba loam, M07 and M08 were detected above the LOQ.  In the 0-7.5 cm soil depth, M08 was detected at a maximum concentration of 0.03 ppm (33% of the initial soil concentration of saflufenacil) at 6 days after treatment and was not detected above the LOQ below this depth.  M07 was detected in the 0-7.5 cm soil depth at a concentration of 0.01 ppm (15% of the initial soil concentration of saflufenacil) at 45 days after treatment and was not detected above the LOQ below this depth.

	The third study was conducted on a loamy sand soil (Quincy soil series) in Washington, a loam soil (Brant soil series) in Ontario, and a clay loam soil (San Joaquin soil series) in California (MRID 47128236).  Saflufenacil was broadcast three times (21- to 23-day interval) at each site at a target application rate of 0.05 kg a.i./ha/application (0.045 lb a.i./A/application), which is the proposed maximum application pattern for use on orchard trees.  Total water input at these sites was 131% to 846% of the historical average.  Soil samples (0-120 cm depth) were collected from each site through 20 days after the first treatment, 20 days after the second treatment, and 360 days after the third.  Following the first application, the mean zero-time concentrations of saflufenacil in the 0-2.5 cm soil depth of each site were 0.09 ppm, 0.10 ppm, and 0.08 ppm, which were 64%, 76%, and 50% of the theoretical, respectively.  Saflufenacil dissipated in the whole soil profile, following the first and third applications, with respective half-lives of 4.6 and 1.4 days in the Washington loamy sand, 7.3 and 23.6 days in the Ontario loam, and 13.0 and 32.3 days in the California clay loam.  The compound was detected above the limit of quantitation (LOQ = 0.01 ppm or 6.3% to 7.6% of the theoretical zero-time concentration) at a maximum depth of 5-15 cm in all three soils (2-10 days after the first treatment and up to 76 days after the third treatment).  However, samples were not analyzed to a sufficient depth to define leaching at the Ontario site.  At 2, 5, and 9 days following the first application, samples were not analyzed below 15 cm despite the detection of saflufenacil in the 5-15 cm depth at these sampling intervals.  Samples were analyzed to a depth of 30-45 cm at all other sampling intervals, with no detection of saflufenacil above the LOQ at that depth on any sampling interval.

	In the Washington loamy sand, M08 was the only degradate detected above the LOQ.  In the 0-2.5 cm soil depth, M08 was detected at a maximum concentration of 0.02 ppm following the all three applications and was not detected above the LOQ below the 2.5-5 cm depth.  In the Ontario loam, M08 and M01 were detected above the LOQ.  In the 0-2.5 cm soil depth, M08 was detected at a maximum concentration of 0.05 ppm at 1 day after the third application and was not detected above the LOQ below the 5-15 cm depth.  In the 0-2.5 cm soil depth, M01 was detected at a maximum concentration of 0.02 ppm at 10 days after the third application and was not detected above the LOQ below this depth.  In the California clay loam, M01, M07, and M08 were detected above the LOQ.  In the 0-2.5 cm soil depth, M01 was detected at a maximum concentration of 0.02 ppm at 20 days after the third treatment, and M07 and M08 were detected at maximum concentrations of 0.02 ppm and 0.01 ppm, respectively, at 20 and 45 days after the third treatment.  M01, M07, and M08 were not detected above the LOQ below this depth.

Environmental Degradates

	Major identified environmental degradates of saflufenacil are M01, M02, M04, M07, M08, M15, M22, M26, M29, M31, M33, TFP, ‘product 8’, and ‘unknown 3/2/2’, an unidentified photodegradate with a liquid chromatography retention time of 3.9 minutes.  Available IUPAC names and chemical structures are listed in Table I.1 of Appendix I as well as maximum and final amounts formed in the submitted studies.  Table I.2 of Appendix I lists the eleven minor degradates of saflufenacil that were identified as well.

	Degradates M01, M02, M08, and product 8 have an intact uracil ring and are most similar to the parent compound.  M01 and M02 were major demethylation products in the aerobic and anaerobic soil metabolism studies.  Product 8 was a major photodegradate on soil that degraded to M01 but was increasing in concentration at the end of the study.  Reduction/saturation of the uracil ring of saflufenacil produced M08, which was a major degradate in the aerobic soil metabolism and soil photolysis studies.

	Degradates M04, M07, M15, and M22 have a cleaved uracil ring, but remain structurally similar to the parent compound.  M04 was a major hydrolytic product at pH 9 but was not detected 18 days after its peak concentration.  M07 was a major degradate in every submitted environmental fate laboratory study with the exception of the anaerobic soil metabolism study.  M15 was a major hydrolytic degradate at pH 9 and a major degradate in the anaerobic aquatic metabolism study.  M22 was a major degradate in the aerobic soil metabolism study.

	Degradates M26, M29, M31, M33, and TFP are trifluorinated cleavage products of the uracil ring that were identified in submitted studies.  M29 is trifluoroacetic acid (CASRN: 76-05-1), a degradation product shared by pesticides, hydrochlorofluorocarbons, (HCFC), and hydrofluorocarbons (HFC).  According to the Hazardous Substances Data Bank, with a vapor pressure of 110 torr at 25°C, trifluoroacetic acid will volatilize if released to the air or dry soil (USNIH, 2009).  It’s half-life in air is estimated at 31 days due to reaction with hydroxyl radicals.  However, if released to water bodies or wet soil, trifluoroacetic acid will form a persistent anion (pKa of 0.52) that will not degrade by abiotic or microbial means.  The compound has been detected in surface water, seawater, and precipitation (USNIH, 2009).

	Fluoroform (trifluoromethane; CASRN: 75-46-7) is a possible terminal product of the trifluorinated degradates of saflufenacil.  According to the Hazardous Substances Data Bank, fluoroform will volatilize from water and soil based on a Henry's Law constant of 0.095 atm-m3/mol and a vapour pressure of 3.5 x 104 torr at 25°C (USNIH, 2009).  However, the compound has been detected in surface water and ground water.  It will persist in air with a half-life of 180 years and gradually diffuse into the stratosphere with a half-life of 20 years (USNIH, 2009).  As an HFC, fluoroform is included with the greenhouse gases subject to the Kyoto Protocol (United Nations, 1998).

Residues of Concern

	The Residues of Concern Knowledgebase Subcommittee (ROCKS) of the Health Effects Division included as residues of concern in drinking water, saflufenacil parent, M01, M02, M07, M08, M15, M22, and product 8.  Due to the structural similarity of these degradates to the parent and a lack of toxicity data, they are assumed to have equivalent toxicity to the parent (USEPA, 2009).  Because product 8 degrades to M01 during handling and/or analysis, identification of the compound and its inclusion as an analyte in environmental chemistry methods are not requested.

	Drinking water exposure to the residues of concern is estimated using available chemical properties and environmental fate data.  A total residues of concern (TRC) approach was used because degradation studies were not performed on the degradates of concern and their patterns of formation and decline were not always well defined in studies on the parent compound.  Table 4 lists the environmental fate parameters for the saflufenacil TRC that were relevant for exposure modeling.  These parameters reflect regression of the total residues at each interval of the biodegradation studies.  Batch equilibrium data were available for the individual degradates of concern (MRID 47127830).  Chemical properties of the parent compound were used to represent those of the residues of concern due to the lack of data on the degradates of concern.  TRC metabolism half-lives were based on the phenyl-labeled systems only in order to include M07, which doesn’t retain the radiolabel on the uracil ring.

Table 4.  Selected environmental fate parameters of the total residues of concern.

Parameter	Value	Source

Persistence

Hydrolysis half-life (25(C)	Stable (pH 5, 7)	MRID 47127823

Aqueous photolysis half-life (22(C)	90.9 d (pH 5)	MRID 47699901

Aerobic soil metabolism half-life (25(C)	9613 d (silt loam; pH 6.1)

1822 d (loamy sand; pH 5.9)

1433 d (silty clay loam; pH 5.5)

987 d (sandy loam; pH 6.8)	MRID 47445901

Aerobic aquatic metabolism half-life (25(C)	416 d (pH 5.8-6.7)	MRID 47127827

Mobility

Range of Freundlich organic carbon normalized partition coefficients (KFOC) (n=6)	M01: 4.8–27 L/kgOC

M02: NCA–41 L/kgOC

M07: 3.3–111 L/kgOC

M08: 4.8–20 L/kgOC

M15: 9.6–57 L/kgOC

M22: NCA–25 L/kgOC	MRID 47127830

A  “NC” means not calculated due to no absorption.

Drinking Water Exposure Modeling

Models

	The FQPA Index Reservoir Screening Tool (FIRST v1.1.1, Mar. 25, 2008; USEPA, 2008) is a Tier I screening model that simulates the upper-end exposure of the standard water body, the Index Reservoir, to pesticide residues in runoff and spray drift from an application within the standard watershed.  Peak and annual mean EDWCs are generated to estimate acute and chronic exposure.  The Index Reservoir covers 5.2 hectares (ha) with an average depth of 2.74 meters (m) in a standard watershed of 172.8 ha.  A more detailed description of the index reservoir watershed can be found in Jones et al., 1998.  The FIRST model and user’s manual are available from the EPA Water Models web-page (USEPA, 2009).

	Screening Concentration in Ground Water (SCI-GROW v2.3, Jul. 29, 2003; USEPA, 2002a) is a regression model used as a screening tool to estimate pesticide concentrations found in ground water used as drinking water.  SCI-GROW was developed by fitting a linear model to ground water concentrations with the Relative Index of Leaching Potential (RILP) as the independent variable.  Ground water concentrations were taken from 90-day average high concentrations from Prospective Ground Water studies.  The RILP is a function of aerobic soil metabolism and the soil-water partition coefficient.  The output of SCI-GROW represents the concentrations of pesticide residue that might be expected in shallow unconfined aquifers under sandy soils, which is representative of the ground water most vulnerable to pesticide contamination and likely to serve as a drinking water source.  The SCI-GROW model and user’s manual is also available from the EPA Water Models web-page (USEPA, 2009).  Both FIRST and SCI-GROW were used to estimate screening-level exposure of drinking water sources to total residues of concern of saflufenacil.

	PRZM GW is a graphical user interface that automates the Pesticide Root Zone Model (PRZM v3.12.2; May 12, 2005; Suarez, 2006) under a NAFTA-harmonized conceptual model for ground water modeling that was subject to peer review by the FIFRA SAP (USEPA, 2005; 2005a).  The conceptual model (Figure 1) represents vulnerable private drinking water wells in the vicinity of agricultural environments.  In this conceptualization, the pesticide is applied to the soil surface (or plant canopy) and precipitation or irrigation drives the pesticide into the soil.  Meteorological, crop, biological, chemical, and management processes affect the transport of the pesticide as it moves through the soil and into a saturated zone.  Horizontal movement of pesticide (advection via runoff or erosion) and subsequent removal is neglected for this model.

Figure 1.  Depiction of the general ground water scenario concept for estimating pesticide concentrations in drinking water with PRZM GW.

 	The saturated zone of the conceptual model is a shallow surficial aquifer with a water table nine meters below the surface.  Concentrations are based on a vertical spatial average starting at the top of the water table down to a depth of 1 meter below the water table.  This is meant to approximate the vertical depth from which a well screen may sample and supply as drinking water.  The location of the well screen was chosen to sample the higher concentrations expected nearer to the water table.

	The conceptual model includes meteorological events with daily resolution that can significantly affect pesticide transport including precipitation, evaporation, snow, temperature, and wind.  Crop descriptions are needed only in regard to how they impact hydrology or pesticide interception.  Management practices such as irrigation and setback distances are included in the conceptual model.  The default environmental fate scheme uses the aerobic soil degradation rate in the top 10 cm and a linearly declining rate with depth to 1 meter, below which only hydrolysis is assumed to occur.

Input Parameters

	Input parameters for FIRST follow in Table 5.  The modeled use pattern represents the maximum proposed use pattern (one aerial application per year at 0.356 lbs a.i./A).  This is proposed for use on Christmas tree, conifer, and hardwood plantations and non-agricultural areas (Sharpen™ formulation).

Table 5.  FIRST input parameters for total residues of saflufenacil following use on tree plantations and non-agricultural areas.  Source data are in Tables 2-4.

Input Parameter	Value	Comments	Source

Application rate (lbs a.i./A)	0.356	Maximum proposed single application rate.	Proposed label.

Number of applications per year	1	Maximum proposed number of applications per year at the maximum proposed single application rate. Proposed label.

Percent cropped area	100%	Default for non-agricultural uses.	Effland et al., 1999

Organic Carbon Partition Coefficient (KOC) (L/kgOC)	5.9	Represents the mean of the lowest KOC values for the residues of concern in non-sand soils (n=7).	MRID 47127829

MRID 47127830

Aerobic soil metabolism half-life (days)	6833	Represents the upper 90% confidence bound on the mean of four half-lives for the residues of concern.	MRID 47445901

Wetted in?	No	Not required.	Proposed label.

Method of application	Aerial	Proposed application method of highest potential spray drift.	Proposed label.

Solubility in water (ppm)	2100	Solubility in pH 7 water.	MRID 47127819

Aerobic aquatic metabolism

half-life (days)	1247	Represents 3x the single available half-life for the residues of concern.	MRID 47127827

Aqueous photolysis half-life (days)	90.9	Represents the maximum environmental phototransformation half-life for the residues of concern. MRID 47699901

	Chemical property input values were chosen in accordance with current input parameter guidance (USEPA, 2002).  Based on analysis of total residues of concern, the 90% confidence bound on the mean aerobic soil metabolism half-life (6833 d), three times the single available aerobic aquatic metabolism half-life (1247 d), and the maximum environmental phototransformation value (90.9 d) were selected.  The KOC input represents the mean of seven values that represent the lowest non-sand KOC for each of the identified residues of concern (i.e., saflufenacil, M01, M02, M07, M08, M15, and M22).

	Standard percent cropped areas (PCA) are used as conservative default estimates of the extent of watershed on which agricultural crops of unknown specific PCA are grown (Effland et al., 1999).  Because PCA values were not available for non-agricultural uses, they were not used for exposure estimates for these uses.

	Input parameters for the SCI-GROW model appear in Table 6.  The mean of the lowest reported organic carbon partition coefficients (KOC = 5.9 L/kgOC) for the residues of concern was selected.  The median total residue half-life (1627 d) from four aerobic soils was selected to approximate the biodegradation kinetics of the residues of concern in aerobic soil environments.

Table 6.  SCI-GROW input parameters for total residues of saflufenacil.  Source data are in Tables 2-4.

Input Parameter	Value	Comments	Source

Application Rate

(lbs a.i./A)	0.356	Maximum proposed single application rate.	Proposed label.

Applications per Year	1	Maximum proposed number of applications per year at the maximum proposed single application rate.	Proposed label.

Organic Carbon Partition Coefficient (KOC) (L/kgOC)	5.9	Represents the mean of the lowest reported KOC values.	MRID 47127829

MRID 47127830

Aerobic Soil Metabolism Half-life (days)	1627	Represents the median total residue half-life in four soils.	MRID 47445901

	Exposure estimates from the Tier I model SCI-GROW were expected to result in chronic dietary risk exceedances, considering food plus drinking water (personal communication with George Kramer, HED; Apr. 6, 2009).  Therefore, the Tier II screening model PRZM GW was used to refine exposure estimates in ground water for drinking water exposure assessment.  Input parameters for PRZM GW appear in Tables 7 and 8.  The mean of the lowest reported organic carbon partition coefficients (KOC = 5.87 L/kgOC) for the residues of concern was selected.  The median total residue half-life (1627 d) from four aerobic soils was selected to approximate the biodegradation kinetics of the residues of concern in aerobic soil environments.  The modeled scenario represents an acidic soil where saflufenacil will not hydrolyze; therefore, an arbitrarily high hydrolysis half-life (10,000 days) was selected to approximate stability to hydrolysis.

Table 7.  PRZM GW input parameters for total residue degradation rates and the proposed use pattern.  Source data are in Tables 2-4.

Input Parameter	Value	Comments	Source

Application Rate

(kg a.i./ha)	0.4	Maximum proposed single application rate.	Proposed label.

Applications per Year	1	Maximum proposed number of applications per year at the maximum proposed single application rate.	Proposed label.

Application Date	July 1st	Arbitrarily selected date for a non-agricultural application.	(none)

Chemical Application Method	2	Represents foliar application.	(none)

Hydrolysis Half-life (days)	10,000	Represents stability to hydrolysis. MRID 47127823

Aerobic Soil Metabolism Half-life (days)	1627	Represents the median total residue half-life in four soils.	MRID 47445901

Organic Carbon Partition Coefficient (KOC) (L/kgOC)	5.87	Represents the mean of the lowest reported KOC values.	MRID 47127829

MRID 47127830

	A previously developed scenario for corn grown in the Delmarva Peninsula was modified for this assessment of non-agricultural areas on the same vulnerable soil, resulting in a provisional “Delmarva non-ag” scenario.  In comparison to other sites across the United States, this scenario is at the high-end of vulnerability, with a sandy, acidic soil in which saflufenacil residues might be highly mobile and relatively persistent.  Exposure to residues in areas of less sandy soils is expected to be less than is estimated with this scenario.

	Modifications to the Delmarva corn scenario include a lengthening of the minimum depth of evaporation to 17.5 cm in order to be consistent with the PRZM-3 User’s Manual (Suarez, 2006) and adjusting the crop-specific inputs (emergence, maturity, and harvest dates and post-harvest foliar flag) to values that do not reflect the presence of a crop.  Bulk density, field capacity, wilting point, and percent organic carbon values were updated to reflect current values reported in the United States Department of Agriculture (USDA) Natural Resources Conservation Service (NRCS) Soil Data Mart report for map unit EvB (map unit EvA, which was used for the corn scenario, was not listed; USDA, 2009) and the Soil Characterization Database (USDA, 2009a).  The remaining values of the provisional Delmarva non-ag scenario are consistent with those of the Delmarva corn scenario.

Table 8.  PRZM GW scenario input parameters (Delmarva non-ag provisional scenario).

Input Parameter	Value	Comments	Source

Meteorological file	W93721	Represents the meteorology of Baltimore, Maryland from 1961 to 1990.	USEPA, 2009b

Pan Evaporation Factor	0.77	Value from PRZM-3 Manual, Figure 5.9	Suarez, 2006

Snow Melt Factor	0.5	Value in the typical range for open areas.	Suarez, 2006

Minimum Depth of Evaporation (cm)	17.5	Value from PRZM-3 Manual, Figure 5.2	Suarez, 2006

Root Depth (cm)	100	Estimated value	(estimate)

Canopy Coverage (%)	90	Estimated value	(estimate)

Canopy Water Holdup (cm)	0.15	Estimated value consistent with PRZM-3 Manual, Table 5.4	(estimate)

Post-harvest Foliar Residue Flag	3	Foliar residues remain on foliage. (none)

Emergence Date	Jan. 1st	Values are not applicable to non-cropped areas. (none)

Maturity Date	Jan. 2nd

Harvest Date	Dec. 31st

Irrigation	None	Irrigation was not simulated.	(none)

Bulk Density	(0-0.1 m)

	(0.1-10 m)	0.78 g/mL

1.7 g/mL	Midpoint of values reported in the NRCS Soil Data Mart for Evesboro soils	USDA, 2009

Field Capacity	(0-9 m)	0.075	Estimated value consistent with the NRCS Soil Characterization Database	USDA, 2009a

Wilting Point	(0-9 m)	0.01	Estimated value consistent with the field capacity minus the available water capacity reported in the NRCS Soil Data Mart for Evesboro soils	USDA, 2009

Percent Organic	(0-0.1 m)

Carbon	(0.1-10 m)	42

0.25	Midpoint of values reported in the NRCS Soil Data Mart for Evesboro soils	USDA, 2009

Modeling Results

	Screening estimates generated for drinking water exposure assessment are listed in Table 9.  The proposed use pattern for the Sharpen™ formulation for use on tree plantations and non-agricultural areas was the maximum use pattern modeled for surface water and ground water exposure estimates, as described above.  Modeled estimates are 1-in-10-year peak and 1-in-10-year annual mean values.  The 30-year daily time series of EDWCs that the Tier II point estimates for ground water represent will be delivered with this assessment to HED for probabilistic modeling in support of human health dietary risk assessment.  Model input/output data and filenames for these estimates are attached in Appendix II.

Table 9.  Drinking Water Exposure Estimates for the Proposed Maximum Use Patterns of Saflufenacil, Tree Plantations and Non-agricultural Areas.

Source (Tier: Model)	1-in-10-year Peak Exposure (μg/L)	1-in-10-year Annual Mean Exposure (μg/L)

Surface water (Tier I: FIRST)	37.3	23.8

Ground water (Tier I: SCI-GROW)	≤1,100A

Ground water (Tier II: PRZM GW)	180	173

A  Ground water concentrations calculated by SCI-GROW are the highest 90-day running average.

	Exposure estimates for total residues in surface water include a 1-in-10-year peak of 37.3 µg/L and a 1-in-10-year annual average of 23.8 µg/L.  The Tier I screening EDWC for total residues in ground water was 1.1 mg/L (ppm).  This value is uncertain because it is based on model inputs that are outside the ranges of values used to develop the model (KOC range of 32 to 180 L/kg; aerobic soil metabolism half-life range of 13 to 1000 days; USEPA, 2002).  Tier II screening EDWCs were generated for ground water because the Tier I value was expected to result in chronic dietary risk exceedances, when considering food plus drinking water (personal communication with George Kramer, HED; Apr. 6, 2009).  Based on the PRZM GW model, the Tier II screening EDWCs in ground water for use in dietary risk assessment are 180 µg/L for acute exposure and 173 µg/L for chronic exposure.  Figure 2 displays EDWCs in ground water simulated with PRZM GW over 30 years.

Figure 2.  Exposure estimates of saflufenacil in Delmarva ground water over thirty years, generated with PRZM GW and a provisional non-agricultural scenario.

Drinking Water Treatment

	The Office of Pesticide Programs (OPP) does not have direct data on the effects of drinking water treatment on saflufenacil.  Flocculation and sedimentation removal may be effective at reducing saflufenacil concentrations.  Carbon filtering may also reduce saflufenacil concentrations due to the compound’s moderate affinity to organic carbon.  Because of the absence of data on saflufenacil, the effects of drinking water treatment were not considered in this assessment.

CONCLUSIONS

	Screening drinking water exposure estimates for proposed saflufenacil uses on selected row crops, orchard trees, vineyards, tree plantations, and non-agricultural areas are represented by the maximum use pattern on tree plantations and non-agricultural areas (Tables 1 and 9).  The total residues of concern of saflufenacil include saflufenacil parent, M01, M02, M07, M08, M15, M22, and Product 8, all of which are assumed to have similar toxicity to saflufenacil parent.  Exposure estimates in ground water (173-180 µg/L) may be higher than those in surface water (24-37 µg/L).

LITERATURE CITATIONS

Effland, W. R., N. C. Thurman, I. Kennedy.  1999.  Proposed Methods for Determining Watershed-derived Percent Crop Areas and Considerations for Applying Crop Area Adjustments to Surface Water Screening Models.  Presentation to the FIFRA Science Advisory Panel, May 27, 1999.  Online at:  HYPERLINK "http://www.epa.gov/scipoly/sap/meetings/1999/052599_mtg.htm" http://www.epa.gov/scipoly/sap/meetings/1999/052599_mtg.htm

Jones, R. D., S. Abel, W. R. Effland, R. Matzner, R. Parker.  1998.  An Index Reservoir for Use in Assessing Drinking Water Exposure.  Proposed Methods for Basin-scale Estimation of Pesticide Concentrations in Flowing Water and Reservoirs for Tolerance Reassessment.  Presentation to FIFRA Science Advisory Panel, June 29-30, 1998.  Online at:  HYPERLINK "http://www.epa.gov/scipoly/sap/meetings/1998/072998_mtg.htm" http://www.epa.gov/scipoly/sap/meetings/1998/072998_mtg.htm

Suarez, L.  2006.  PRZM-3, A Model for Predicting Pesticide and Nitrogen Fate in the Crop Root and Unsaturated Soil Zones: Users Manual for Release 3.12.2.  Revision A.  EPA/600/R-05/111.  September, 2006.

United Nations.  1998.  Kyoto Protocol to the United Nations Framework Convention on Climate Change.  Online at:   HYPERLINK "http://unfccc.int/resource/docs/convkp/kpeng.pdf"  http://unfccc.int/resource/docs/convkp/kpeng.pdf

United States Department of Agriculture (USDA).  2009.  Soil Data Mart.  U.S. Department of Agriculture, Natural Resources Conservation Service.  Online at:   HYPERLINK "http://soildatamart.nrcs.usda.gov/"  http://soildatamart.nrcs.usda.gov/

USDA.  2009a.  Soil Characterization Database.  U.S. Department of Agriculture, Natural Resources Conservation Service.  Online at:   HYPERLINK "http://ssldata.nrcs.usda.gov/"  http://ssldata.nrcs.usda.gov/

United States Environmental Protection Agency (USEPA).  2002.  Guidance for Selecting Input Parameters in Modeling the Environmental Fate and Transport of Pesticides.  U.S. Environmental Protection Agency, Office of Pesticide Programs, Environmental Fate and Effects Division.  Feb. 28, 2002.  Online at:  HYPERLINK "http://www.epa.gov/oppefed1/models/water/input_guidance2_28_02.htm" http://www.epa.gov/oppefed1/models/water/input_guidance2_28_02.htm

USEPA.  2002a.  SCI-GROW User’s Manual.  U.S. Environmental Protection Agency, Office of Pesticide Programs, Environmental Fate and Effects Division.  Nov. 1, 2001; revised Aug. 23, 2002.

USEPA.  2005.  N-Methyl Carbamate Pesticide Cumulative Risk Assessment: Pilot Cumulative Analysis.  Docket Number: OPP-2004-0405.  Feb. 15-18, 2005.

USEPA.  2005a.  Preliminary N-Methyl Carbamate Cumulative Risk Assessment.  Docket Number: OPP-2005-0172.  Aug. 23-26, 2005.

USEPA.  2006.  Standardized Soil Mobility Classification Guidance.  U.S. Environmental Protection Agency, Office of Prevention, Pesticides and Toxic Substances, Office of Pesticide Programs, Environmental Fate and Effects Division, Memorandum.  Apr. 21, 2006.

USEPA.  2008.  FIRST User’s Manual.  Version 1.1.1.  U.S. Environmental Protection Agency, Office of Pesticide Programs, Environmental Fate and Effects Division.  Mar. 26, 2008.

USEPA.  2009.  Ingredient: Saflufenacil.  Report of the Residues of Concern Knowledgebase Subcommittee (ROCKS).  U.S. Environmental Protection Agency, Office of Prevention, Pesticides, and Toxic Substances, Health Effects Division.  Internal memorandum.  Jan. 6, 2009.

USEPA.  2009a.  Water Models.  U.S. Environmental Protection Agency, Pesticides: Science and Policy, Models and Databases.  Last updated Mar. 23, 2009.  Online at:   HYPERLINK "http://www.epa.gov/oppefed1/models/water/"  http://www.epa.gov/oppefed1/models/water/

USEPA.  2009b.  Meteorological Data.  U.S. Environmental Protection Agency, Center for Exposure Assessment Modeling.  Last Updated Dec. 23, 2008.  Online at:   HYPERLINK "http://www.epa.gov/ceampubl/tools/metdata/index.html"  http://www.epa.gov/ceampubl/tools/metdata/index.html

United States National Institutes of Health (USNIH).  2009.  Hazardous Substances Data Bank.  United States National Institutes of Health, National Library of Medicine, Specialized Information Services, Environmental Health and Toxicology, Toxicology Data Network (TOXNET®), Hazardous Substances Data Bank (HSDB®).  Last updated: Jun. 12, 2008.  Online at:   HYPERLINK "http://toxnet.nlm.nih.gov/"  http://toxnet.nlm.nih.gov/

Submitted Environmental Fate Studies

MRID 47127817.  Beery, J.  BAS 800 H: Dissociation Constant.  Unpublished amended study performed, sponsored and submitted by BASF Corporation, Research Triangle Park, North Carolina.  Study Protocol ID.: F200524.  Feb. 14, 2006.

MRID 47127818.  Vanhook, C.  BAS 800 H: Partition Coefficient (n-Octanol/Water) Estimation by High Performance Liquid Chromatography.  Unpublished study performed, sponsored, and submitted by BASF Corporation, Research Triangle Park, North Carolina.  Study Protocol ID.: 132458.  Dec. 13, 2005.

MRID 47127819.  Vanhook, C.  BAS 800 H: Water Solubility at 20°C by Shake Flask Method.  Unpublished study performed, sponsored, and submitted by BASF Corporation, Research Triangle Park, North Carolina.  Study Protocol ID.: 132452a.  Dec. 2, 2005.

MRID 47127821.  Kroehl, T.  BAS 800 H – Reg.No. 4054449 : Physical Properties of the Pure Active Ingredient.  Unpublished study performed by BASF Aktiengesellschaft, Limburgerhof, Germany; submitted by BASF Corporation, Research Triangle Park, North Carolina.  Study Report Number: 132464-1.  Sep. 30, 2005.

MRID 47127822.  Paulick, R.  Determination of the Henry’s Law Constant for BAS 800 H at 25°C.  Unpublished study performed, sponsored, and submitted by BASF Corporation, Research Triangle Park, North Carolina.  BASF Registration Document Number: 2007/7013512.  Dec. 26, 2007.

MRID 47127823.  Panek, M.  2006.  Hydrolysis of 14C-BAS 800 H.  Unpublished study performed, sponsored, and submitted by BASF Corporation, Research Triangle Park, North Carolina.  BASF Reg. Doc. No.: 2005/7004259.  BASF Study No.: 132680.  Oct. 10, 2006.

MRID 47699901.  Ta, C., and J. Trollinger.  2009.  Aqueous photolysis of 14C-BAS 800 H.  Unpublished amended study performed, sponsored, and submitted by BASF Corporation, Research Triangle Park, North Carolina.  Study Protocol ID: 132683.  Nov. 9, 2007.

MRID 47127825.  Ta, C. 2007.  BAS 800 H: Soil photolysis.  Unpublished amended study performed, submitted, and sponsored by BASF Corporation, Research Triangle Park, North Carolina.  Study Protocol ID: 132653.  Nov. 13, 2007.

MRID 47445901.  Singh, M.  2008.  Aerobic soil metabolism of 14C-BAS 800 H on US soils.  Unpublished amended study performed, sponsored, and submitted by BASF Corporation, Research Triangle Park, North Carolina.  Study Protocol ID.: 132650.  May 30, 2008.

MRID 47611201.  Panek, M. and A. Pyles.  2008.  Anaerobic soil metabolism of 14C-BAS 800 H.  Unpublished study performed, sponsored, and submitted by BASF Corporation, Research Triangle Park, North Carolina.  BASF Study No.: 332554.  Dec. 15, 2008.

MRID 47127828.  Panek, M.  2007.  Anaerobic aquatic metabolism of 14C-BAS 800 H.  Unpublished study performed by BASF Agro Research, Research Triangle Park, North Carolina and Agvise Laboratories, Northwood, North Dakota; sponsored and submitted by BASF Corporation, Research Triangle Park, North Carolina.  Study Protocol ID.: 1326470.  Oct. 18, 2007.

MRID 47127827.  Malinsky, D.S.  2008.  Aerobic aquatic metabolism of 14C-BAS 800 H under dark and light conditions.  Unpublished study performed by BASF Agro Research, Research Triangle Park, North Carolina and Agvise Laboratories, Northwood, North Dakota; sponsored and submitted by BASF Corporation, Research Triangle Park, North Carolina.  BASF No.: 133487.  Jan. 4, 2008.

MRID 47127829.  Ta, C.T. and J. R. Varner.  2007.  Adsorption/desorption of BAS 800 H on soils.  Unpublished study performed, sponsored, and submitted by BASF Corporation, Research Triangle Park, NC.  BASF Study Number: 132674.  Jul. 17, 2007.

MRID 47127830.  Ta, C.T.  2007.  Adsorption/desorption of the major metabolites (M800H01, M800H02, M800H07, M800H08, M800H15, and M800H22) of BAS 800 H on soils.  Unpublished study performed, sponsored, and submitted by BASF Corporation, Research Triangle Park, NC.  Study No. 132677.  Nov. 19, 2007.

MRID 47127834.  Jordan, J.M., M.G. Saha, and R.L. Warren.  2007.  Terrestrial field dissipation of BAS 800 H in pine/vegetation management use patterns.  Unpublished study performed by BASF Agro Research, Research Triangle Park, North Carolina, Agvise Laboratories, Inc., Northwood, North Dakota (soil characterization), and Research Options, Inc., Montezuma, Georgia (field phase); sponsored and submitted by BASF Agro Research, Research Triangle Park, North Carolina.  BASF Study No.: 132665.  Dec. 7, 2007.

MRID 47127835.  Jordan, J., M.G. Saha, and R. Warren.  2008.  Terrestrial field dissipation of BAS 800 H in row crop use patterns.  Unpublished study performed by BASF Agro Research, Research Triangle Park, North Carolina, Mid-South Ag Research, Proctor, Arkansas (field phase), Alvey Agricultural Research, Carlyle, Illinois (field phase), ICMS, Inc., Portage la Prairie, Canada (field phase), and Agvise Laboratories, Inc., Northwood, North Dakota (soil characterization), and sponsored and submitted by BASF Agro Research, Research Triangle Park, North Carolina.  BASF Study No.: 132668.  Jan. 8, 2008.

MRID 47127836.   Jordan, J., M.G. Saha, and R. Warren.  2007.  Terrestrial field dissipation of BAS 800 H in orchard and vineyard use patterns.  Unpublished study performed by BASF Agro Research, Research Triangle Park, North Carolina, Qualls Agricultural Research, Ephrata, Washington (field phase), Vaughn Agricultural Research Services, Branchton, Ontario, Canada (field phase), Research for Hire, Porterville, California (field phase), and Agvise Laboratories, Inc., Northwood, North Dakota (soil characterization), and sponsored and submitted by BASF Agro Research, Research Triangle Park, North Carolina.  BASF Study No.: 134549.  Dec. 19, 2007.

Appendix I.  Chemical Names, Structures, and Maximum Reported Amounts of Saflufenacil and Its Degradates.

 N′-{2-Chloro-4-fluoro-5-[1,2,3,6-tetrahydro-3-methyl-2,6-dioxo-4-(tri fluoromethyl)pyrimidin-1-yl]benzoyl}-N-isopropyl-N-methylsulfamide

CAS: 2-Chloro-5-[3,6-dihydro-3-methyl-2,6-dioxo-4-(trifluoromethyl)-1(2H)-pyr imidinyl]-4-fluoro-N-[[methyl(1-methylethyl)amino] sulfonyl]benzamide

CAS-no: 372137-35-4

Formula: C17H17ClF4N4O5S

MW: 500.86 g/mol

MAJOR (>10%) TRANSFORMATION PRODUCTS

M01

M800H01

	N’-[2-Chloro-4-fluoro-5-(3-methyl-2,6-dioxo-4-(trifluoromethyl)-3,6-d ihydro-1(2H)-pyrimidinyl)benzoyl]-N’-isopropylsulfamide

Formula: C16H15ClF4N4O5S

	Aerobic soil	10 (57)	1.3 (330)

	Anaerobic soil	14 (-3, 34)	10 (75)

	Soil photolysis	5.4 (14)	nd1 (30)

	Aqueous photolysis 	not detected

	Hydrolysis	not identified

	Aerobic aquatic	not detected

	Anaerobic aquatic	not identified

	Field studies	0.02 ppm (0-8, 11, 20)	nd1 (124, 271, 360)

M02

M800H02 N’-[2-Chloro-5-(2,6-dioxo-4-(trifluoromethyl)-3,6-dihydro-1(2H)-pyrimi dinyl)-4-fluorobenzoyl]-N-isopropyl-N-methylsulfamide

Formula: C16H15ClF4N4O5S

 	Aerobic soil	30 (246)	17 (330)

	Anaerobic soil	24 (75)	24 (75)

	Soil photolysis	not detected

	Aqueous photolysis 	not detected

	Hydrolysis	not identified

	Aerobic aquatic	not detected

	Anaerobic aquatic	not identified

	Field studies	0.01 ppm (0-2, 6)	nd1 (360)

M04

M800H04	Formula: C17H19ClF4N4O6S

 	Aerobic soil	not identified

	Anaerobic soil	not identified

	Soil photolysis	not identified

	Aq. photolysis -pH5

Aq. photolysis -pH7	4.1 (20)

5.4 (10)	4.1 (20)

1.8 (21)

	Hydrolysis -pH7

Hydrolysis -pH9	0.95 (30)

13 (3)	0.95 (30)

nd1 (30)

	Aerobic aquatic	not identified

	Anaerobic water

Anaerobic sediment

Anaerobic system	4.4 (62)

0.5 (62)

4.4 (62)	nd1 (364)

nd1 (364)

nd1 (364)

	Field studies	not analyzed

M07

M800H07

	N-{4-Chloro-2-fluoro-5-[({[isopropyl (methyl) amino] sulfonyl} amino) carbonyl] phenyl}-N’-methylurea

Formula: C13H18ClFN4O4S

	Aerobic soil	52 (25)	7.2 (330)

	Anaerobic soil	4.4 (60)	1.5 (75)

	Soil photolysis	19 (14)	2.3 (30)

	Aq. photolysis -pH5

Aq. photolysis -pH7	8.6 (20)

9.5 (15)	8.6 (20)

8.2 (21)

	Hydrolysis –pH7

Hydrolysis –pH9	9.2 (30)

77 (30)	9.2 (30)

77 (30)

	Aerobic water

Aerobic sediment

Aerobic system 	20 (30)

3.7 (60)

23 (60)	19 (60)

3.7 (60)

23 (60)

	Anaerobic water

Anaerobic sediment

Anaerobic system	62 (364)

13 (91)

71 (91)	62 (364)

6.7 (364)

68 (364)

	Field studies	0.02 ppm (11, 20, 44)	nd1 (124, 271)

M08

M800H08

	N’-[2-Chloro-4-fluoro-5-(3-methyl-2,6-dioxo-4-(trifluoromethyl) tetrahydro-1(2H)-pyrimidinyl) benzoyl]-N-isopropyl-N-methylsulfamide

Formula: C17H19ClF4N4O5S

	Aerobic soil	66 (246)	41 (330)

	Anaerobic soil	25 (18)	18 (75)

	Soil photolysis	19 (22)	18 (30)

	Aqueous photolysis 	not detected

	Hydrolysis	not identified

	Aerobic aquatic	not detected

	Anaerobic aquatic	not identified

	Field studies	0.05 ppm (1, 6)	nd1 (124, 360)

M15

M800H15	N-{4-Chloro-2-fluoro-5-[({[isopropyl (methyl) amino] sulfonyl} amino) carbonyl] phenyl}-4-4-4-trifluoro-3,3-dihydroxybutanamide

Formula: C15H18ClF4N3O6S

 	Aerobic soil	not identified

	Anaerobic soil	1.6 (18)	nd1 (75)

	Soil photolysis	9.6 (30)	9.6 (30)

	Aq. photolysis -pH5

Aq. photolysis -pH7	2.3 (20)

1.3 (10)	2.3 (20)

nd1 (21)

	Hydrolysis –pH7

Hydrolysis –pH9	2.3 (30)

22 (30)	2.3 (30)

22 (30)

	Aerobic aquatic	not detected

	Anaerobic water

Anaerobic sediment

Anaerobic system	17 (62-91)

0.9 (273)

17 (62-91)	7.1 (364)

0.8 (364)

7.6 (364)

	Field studies	not detected

M22

M800H22

	3-[({4-Chloro-2-fluoro-5-[({[isopropyl(methyl)amino]sulfonyl}amino)carb onyl]anilino}carbonyl)(methyl)amino]-4,4,4-trifluorobutanoic acid

Formula: C17H21ClF4N4O6S

 	Aerobic soil	16 (43)	7.1 (334)

	Anaerobic soil	1.6 (60)	0.2 (75)

	Soil photolysis	not detected

	Aqueous photolysis 	not detected

	Hydrolysis	not identified

	Aerobic aquatic	not detected

	Anaerobic aquatic	not identified

	Field studies	not detected

M26

M800H26

	N-Methyl-2,2,2-trifluoroacetamide

Formula: C3H4F3NO

 	Aerobic soil	18 (25)	nd1 (334)

	Anaerobic soil	not identified

	Soil photolysis	not identified

	Aqueous photolysis 	not identified

	Hydrolysis	not identified

	Aerobic aquatic	not identified

	Anaerobic aquatic	not identified

	Field studies	not analyzed

M29

M800H29

TFA

(also formulated as TFA, sodium salt)	Trifluoroacetic acid

Formula: C2HF3O2

 	Aerobic soil	not identified but not quantified

	Anaerobic soil	6.9 (0)	3.7 (75)

	Soil photolysis	not identified

	Aq. photolysis -pH5

Aq. photolysis -pH7	4.0 (20)

29 (21)	4.0 (20)

29 (21)

	Hydrolysis	not identified

	Aerobic water

Aerobic sediment

Aerobic system 	6.9 (60)

2.0 (51-60)

8.8 (60)	6.9 (60)

2.0 (60)

8.8 (60)

	Anaerobic water

Anaerobic sediment

Anaerobic system	9.2 (364)

3.6 (91)

11 (364)	9.2 (364)

1.9 (364)

11 (364)

	Field studies	not analyzed

M31

M800H31

3-[Carboxy(methyl)amino]-4,4,4-trifluorobutanoic acid

Formula: C6H8F3NO4

 	Aerobic soil	18 (43)	8.7 (334)

	Anaerobic soil	not identified

	Soil photolysis	not identified

	Aqueous photolysis 	not identified

	Hydrolysis	not identified

	Aerobic aquatic	not identified

	Anaerobic aquatic	not identified

	Field studies	not analyzed

M33

M800H33

1,1,1-Trifluoroacetone

CAS-no: 421-50-1

Formula: C3H3F3O

 	Aerobic soil	not identified

	Anaerobic soil	not identified

	Soil photolysis	not identified

	Aq. photolysis -pH5

Aq. photolysis -pH7	3.2 (20)

20 (15)	3.2 (20)

17 (21)

	Hydrolysis –pH7

Hydrolysis –pH9	4.7 (30)

74 (21)	4.7 (30)

73 (30)

	Aerobic water

Aerobic sediment

Aerobic system 	23 (7)

nd1

23 (7)	3.2 (60)

nd1

 3.2 (60)

	Anaerobic water

Anaerobic sediment

Anaerobic volatiles

Anaerobic system	15 (62)

0.9 (62)

13 (160-364)

25 (62)	nd1 (364)

nd1 (364)

13 (364)

13 (364)

	Field studies	not analyzed

TFP	1,1,1-Trifluoro-2-propanol

CAS-no: 374-01-6

Formula: C3H5F3O

	Aerobic soil	not identified

	Anaerobic soil	not identified

	Soil photolysis	not identified

	Aqueous photolysis 	not identified

	Hydrolysis	not identified

	Aerobic aquatic	not identified

	Anaerobic water

Anaerobic sediment

Anaerobic volatiles

Anaerobic system	16 (62)

3.4 (62)

24 (160-364)

30 (62)	0.4 (364)

nd1 (364)

24 (364)

24 (364)

	Field studies	not analyzed

Product 8

Formula: C17H15ClF4N4O6S

MW: 516.86 g/mol

 	Aerobic soil	not identified

	Anaerobic soil	not identified

	Soil photolysis	17 (15)	17 (15)

	Aqueous photolysis 	not identified

	Hydrolysis	not identified

	Aerobic aquatic	not identified

	Anaerobic aquatic	not identified

	Field studies	not analyzed

Unknown 3/2/2	Unknown compound with tR 3.9 min that formed under irradiated conditions in the aqueous photolysis study, including unknowns 2 (phenyl-labeled) in the pH5 study and unknowns 3 (phenyl-labeled) and 2 (uracil-labeled) in the pH7 study.	Unknown	Aq. photolysis -pH5

Aq. photolysis -pH7	1.0 (20)

9.5 (21)	1.0 (20)

9.5 (21)

1 “nd” means that the compound was not detected.

Table I.2.  Minor Organic Environmental Degradates of Saflufenacil.

Code	Chemical name	Chemical structure	Study Type	Maximum %AR (day)	Final %AR (study length)

M06

M800H06 N-[2-Chloro-4-fluoro-5-(3-methyl-2,6-dioxo-4-(trifluoromethyl)tetrahydro -1(2H)-pyrimidinyl)benzoyl]-N’-isopropylsulfamide

Formula: C16H17ClF4N4O5S

 	Aerobic soil	identified but not quantified

	Anaerobic soil	not identified

	Soil photolysis	not identified

	Aqueous photolysis 	not identified

	Hydrolysis	not identified

	Aerobic aquatic	not identified

	Anaerobic aquatic	not identified

	Field studies	not analyzed

M11

M800H11	N’-[2-Chloro-5-(2,6-dioxo-4-

(trifluoromethyl)-3,6-dihydro-1(2H)-pyrimidinyl)-4-fluorobenzoyl]-N-isop ropylsulfamide

Formula: C15H13ClF4N4O5S

	Aerobic soil	not analyzed

	Anaerobic soil	not identified

	Soil photolysis	not analyzed

	Aqueous photolysis 	not analyzed

	Hydrolysis	not analyzed

	Aerobic aquatic	not detected

	Anaerobic aquatic	not analyzed

	Field studies	not analyzed

M16

M800H18

	2-Chloro-4-fluoro-N-{isopropyl (methyl)-amino] sulfonyl}-5-[(4,4,4-trifluoro-2,3-dihydroxybutanyl) amino] benzamide

Formula: C15H18ClF4N3O6S

	Aerobic soil	not identified

	Anaerobic soil	not identified

	Soil photolysis	not identified

	Aqueous photolysis 	not identified

	Hydrolysis	not identified

	Aerobic aquatic	not identified

	Anaerobic water

Anaerobic sediment

Anaerobic system	8.4 (364)

0.9 (273-364)

9.3 (364)	8.4 (364)

0.9 (364)

9.3 (364)

	Field studies	not analyzed

M18

M800H18

	2-Chloro-4-fluoro-N-[(isopropylamino) sulfmony]-5-{[(methylamino) carbonyl] amino} benzamide

Formula: C12H16ClFN4O4S

	Aerobic soil	not identified

	Anaerobic soil	not identified

	Soil photolysis	not identified

	Aqueous photolysis 	not identified

	Hydrolysis	not identified

	Aerobic aquatic	not identified

	Anaerobic water

Anaerobic sediment

Anaerobic system	6.2 (273)

0.9 (364)

7.0 (273)	6.0 (364)

0.9 (364)

6.7 (364)

	Field studies	not analyzed

M24

M800H24

	(2E)-3-({[4-Chloro-2-fluoro-5-({[(methylamino)sulfonyl] amino}carbonyl)aniline]carbonyl}amino)-4,4,4-trifluoro-2-butenoic acid

Formula: C13H11ClF4N4O6S

	Aerobic soil	identified but not quantified

	Anaerobic soil	not identified

	Soil photolysis	not identified

	Aqueous photolysis 	not identified

	Hydrolysis	not identified

	Aerobic aquatic	not identified

	Anaerobic aquatic	not identified

	Field studies	not analyzed

M25

M800H25

	2-Chloro-4-fluoro-5-(3-methyl-2,6-dioxo-4-(trifluoromethyl)-3,6-dihydro -1(2H)-pyrimidinyl)benzamide

Formula: C13H8ClF4N3O3

	Aerobic soil	identified but not quantified

	Anaerobic soil	not identified

	Soil photolysis	not identified

	Aq. photolysis -pH5

Aq. photolysis -pH7	2.9 (20)

1.8 (15)	2.9 (20)

1.3 (21)

	Hydrolysis	not identified

	Aerobic aquatic	not identified

	Anaerobic aquatic	not identified

	Field studies	not analyzed

M27

M800H27

	N-[2-Chloro-5-(2,6-dioxo-4-(trifluoromethyl)tetrahydro-1(2H)-pyrimidiny l)-4-fluorobenzoyl]-N’-isopropylsulfamide

Formula: C15H15ClF4N4O5S

	Aerobic soil	identified but not quantified

	Anaerobic soil	not identified

	Soil photolysis	not identified

	Aqueous photolysis 	not identified

	Hydrolysis	not identified

	Aerobic aquatic	not identified

	Anaerobic aquatic	not identified

	Field studies	not analyzed

M28

M800H28

	N-[2-Chloro-4-fluoro-5-(3-methyl-2,6-dioxo-4-(trifluoromethyl)tetrahydr o-1(2H)-pyrimidinyl)benzoyl]-N’-methylsulfamide

Formula: C14H13ClF4N4O5S

	Aerobic soil	identified but not quantified

	Anaerobic soil	not identified

	Soil photolysis	not identified

	Aqueous photolysis 	not identified

	Hydrolysis	not identified

	Aerobic aquatic	not identified

	Anaerobic aquatic	not identified

	Field studies	not analyzed

M30

M800H30

	2-Chloro-4-fluoro-5-(3-methyl-2,6-dioxo-4-(trifluoromethyl)tetrahydro-1 (2H)-pyrimidinyl)benzamide

Formula: C13H10ClF4N3O3

	Aerobic soil	identified but not quantified

	Anaerobic soil	not identified

	Soil photolysis	not identified

	Aqueous photolysis 	not identified

	Hydrolysis	not identified

	Aerobic aquatic	not identified

	Anaerobic aquatic	not identified

	Field studies	not analyzed

M35

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

Formula: C11H14ClFN4O4S

	Aerobic soil	identified but not quantified

	Anaerobic soil	not identified

	Soil photolysis	not identified

	Aqueous photolysis 	not identified

	Hydrolysis	not identified

	Aerobic aquatic	not detected

	Anaerobic aquatic	not identified

	Field studies	not analyzed

Product 3 2-Chloro-5-[2,6-dioxo-4-(trifluoromethyl)-3,6-dihydropyrimidin-1(2H)-yl] -4-fluorobenzamide

Formula: C12H6ClF4N3O3

 	Aerobic soil	not identified

	Anaerobic soil	not identified

	Soil photolysis	9.2 (30)	9.2 (30)

	Aqueous photolysis 	not identified

	Hydrolysis	not identified

	Aerobic aquatic	not identified

	Anaerobic aquatic	not identified

	Field studies	not analyzed

Hydroxyl methyl degradate	2-Chloro-5[4-difluoro(hydroxyl) methyl]-(3-methyl-2,6-dioxo-3,6-dihydropyrimidin-1(2H)-yl-N-{[isopropyl( methyl)amino]sulfonyl} benzamide

Formula: C17H19ClF2N4O6S

 	Aerobic soil	not identified

	Anaerobic soil	not identified

	Soil photolysis	not identified

	Aq. photolysis -pH5

Aq. photolysis -pH7	5.3 (10)

3.3 (15)	2.5 (20)

1.0 (21)

	Hydrolysis	not identified

	Aerobic aquatic	not identified

	Anaerobic aquatic	not identified

	Field studies	not analyzed

Appendix II.  Model Input/Output Data.

Table II.1.  Summary of Input/Output Files.

File name	Date	Location/Simulation

Input/Output File for FIRST

Saf4.fir	Apr. 2, 2009	National screen

Input/Output File for SCI-GROW

Saf.sci	Apr. 8, 2009	National screen

Input File for PRZM GW

Saf-nonag 4-9-09.PGI	Apr. 9, 2009	Delmarva non-agricultural area

Crop Scenario File for PRZM GW

Delmarva non-ag 4-9-09.SCN	Apr. 9, 2009	Delmarva non-agricultural area

Weather Data File for PRZM GW

W93721.dvf	Jul. 3, 2002	Baltimore, MD

Example Input/Output Data for Individual Simulations

FIRST Input/Output File.

   RUN No.   1 FOR Saflufenacil     ON   Non-ag        * INPUT VALUES *

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

    RATE (#/AC)   No.APPS &   SOIL  SOLUBIL  APPL TYPE  %CROPPED INCORP

     ONE(MULT)    INTERVAL    Koc   (PPM )   (%DRIFT)     AREA    (IN)

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

   0.356(  0.356)   1   1       5.9 2100.0   AERIAL(16.0) 100.0   0.0

   FIELD AND RESERVOIR HALFLIFE VALUES (DAYS)

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

   METABOLIC  DAYS UNTIL  HYDROLYSIS   PHOTOLYSIS   METABOLIC  COMBINED

    (FIELD)  RAIN/RUNOFF  (RESERVOIR)  (RES.-EFF)   (RESER.)   (RESER.)

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

   6833.00        2           0.00   90.90-11271.60  ******    1122.78

   UNTREATED WATER CONC (MICROGRAMS/LITER (PPB)) Ver 1.1.1  MAR 26, 2008

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

        PEAK DAY  (ACUTE)      ANNUAL AVERAGE (CHRONIC)

          CONCENTRATION             CONCENTRATION

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

             37.341                     23.847

SCI-GROW Input/Output File.

 SciGrow version 2.3

 chemical:Saflufenacil

 time is  4/ 2/2009  17: 0:21

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

  Application      Number of       Total Use    Koc      Soil Aerobic

  rate (lb/acre)  applications   (lb/acre/yr)  (ml/g)   metabolism (days)

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

      0.356           1.0           0.356      0.00E+00     1627.0

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

 groundwater screening cond (ppb) =   5.08E+03

 *********************************************************************** *

PRZM GW Input File.

Saflufenacil

10000

1627

5.87

1

1

6

7

8

9

10

7

8

9

10

15

7

3

4

5

5

5

9

10

11

11

12

0.4

4

2.0

2.1

.987

.0001234

33

34

35

36

.009765632

2

1

1

1

1

2

2

1

1

1

1

Delmarva

C:\Models\Inputs\Metfiles\w93721.dvf

0.77

0.5

17.5

100

90

0.15

1

1

2

1

31

12

3

1

66

67

68

1.515

1.514

1.513

1.512

1.511

1.56

1.509

1.508

1.507

1.506

1.505

1.8

0.15

0.14

0.13

0.12

0.11

0.10

0.09

0.08

0.07

0.06

0.05

0.015

0.014

0.013

0.012

0.011

0.010

0.009

0.008

0.007

0.006

0.005

1.5

1.4

1.3

1.2

1.1

1.0

0.9

0.8

0.7

0.6

0.5

0.1

0.78

1.7

1.7

1.7

1.7

1.7

1.7

1.7

0.075

0.075

0.075

0.075

0.075

0.075

0.075

0.01

0.01

0.01

0.01

0.01

0.01

0.01

42

0.25

0.25

0.25

0.25

0.25

0.25

0.25

 PAGE

 PAGE   2


[Federal Register: November 15, 2005 (Volume 70, Number 219)]
[Notices]
[Page 69364-69365]
[DOCID:fr15no05-94]

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SECURITIES AND EXCHANGE COMMISSION

[File No. 1-08366]

Issuer Delisting; Notice of Application of Polydex
Pharmaceuticals Limited To Withdraw Its Common Stock, $.0167 Par Value,
From Listing and Registration on the Boston Stock Exchange, Inc.

November 8, 2005.
    October 26, 2005, Polydex Pharmaceuticals Limited, a company
organized under the laws of the Commonwealth of the Bahamas
(``Issuer''), filed an application with the Securities and Exchange
Commission (``Commission''), pursuant to section 12(d) of the
Securities Exchange Act of 1934 (``Act'') \1\ and Rule 12d2-2(d)
thereunder,\2\ to withdraw its common stock, $.0167 par value
(``Security''), from listing and registration on the Boston Stock
Exchange, Inc. (``BSE'').
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    \1\ 15 U.S.C. 78l(d).
    \2\ 17 CFR 240.12d2-2(d).
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    On July 20, 2005, the Board of Directors (``Board'') of the Issuer
approved resolutions to withdraw the Security from listing and
registration on BSE. The Issuer stated that the following reasons
factored into the Board's decision to delist the Security from BSE.
First, the Security is traded on the Nasdaq SmallCap Market
(``Nasdaq'') in addition to being listed on BSE. The Board believes
that consolidation of trading of the Security on one market would be in
the best interest of, and eliminate confusion among, the Issuer's
shareholders. The Board believes that the continued listing of the
Security on BSE does not offer any significant benefits to the Issuer's
shareholders, and that such continued listing is not worth the
additional cost to the Issuer with respect to fees, expenses and
employee time in connection therewith. Second, the Issuer received a
letter from BSE on March 23, 2005, and in response, decided to withdraw
the Security from listing and registration on BSE.
    The Issuer stated in its application that it has complied with
applicable rules of BSE by complying with all applicable laws in the
Commonwealth of the Bahamas, the jurisdiction in

which the Issuer is incorporated, and by filing the required documents
governing the withdrawal of securities from listing and registration on
BSE.
    The Issuer's application relates solely to withdrawal of the
Security from listing on BSE and from registration under section 12(b)
of the Act,\3\ and shall not affect its obligation to be registered
under section 12(g) of the Act.\4\
---------------------------------------------------------------------------

    \3\ 15 U.S.C. 78l(b).
    \4\ 15 U.S.C. 78l(g).
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    Any interested person may, on or before December 5, 2005, comment
on the facts bearing upon whether the application has been made in
accordance with the rules of BSE, and what terms, if any, should be
imposed by the Commission for the protection of investors. All comment
letters may be submitted by either of the following methods:

Electronic Comments

     Use the Commission's Internet comment form (http://www.sec.gov/rules/delist.shtml.
); or     Send an e-mail to<EMAIL_ADDRESS>Please include

the File Number 1-08366; or

Paper Comments

     Send paper comments in triplicate to Jonathan G. Katz,
Secretary, Securities and Exchange Commission, 450 Fifth Street, NW.,
Washington, DC 20549-9303. All submissions should refer to File Number
1-08366. This file number should be included on the subject line if e-
mail is used. To help us process and review your comments more
efficiently, please use only one method. The Commission will post all
comments on the Commission's Internet Web site (http://www.sec.gov/rules/delist.shtml
). Comments are also available for public inspection

and copying in the Commission's Public Reference Room. All comments
received will be posted without change; we do not edit personal
identifying information from submissions. You should submit only
information that you wish to make available publicly.
    The Commission, based on the information submitted to it, will
issue an order granting the application after the date mentioned above,
unless the Commission determines to order a hearing on the matter.

    For the Commission, by the Division of Market Regulation,
pursuant to delegated authority.\5\
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    \5\ 17 CFR 200.30-3(a)(1).
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Jonathan G. Katz,
Secretary.
 [FR Doc. E5-6265 Filed 11-14-05; 8:45 am]

BILLING CODE 8010-01-P