  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 (703-305-6140) 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   

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