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

Elizabeth Behl, Branch Chief

Environmental Risk Branch IV

Environmental Fate and Effects Division (7507P)

1. EXECUTIVE SUMMARY

This assessment provides estimated drinking water concentrations (EDWC) of 

saflufenacil [BAS 800 H; N′-{2-chloro-4-fluoro-5-[1,2,3,6-tetrahydro-3-methyl-2,6-dioxo-4-

(trifluoromethyl)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 
2

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.

Table 1. Tiered Drinking Water Exposure Estimates for Proposed Saflufenacil Uses.

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 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).

2. 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 SCIGROW (a Tier I model) and PRZM GW (a Tier II model).
3

3. ANALYSIS

3.1. 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 enduse product label BAS 800 04H FiRoCrop Herbicide. The compound belongs to the mode-ofaction 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.

Five end use formulations of saflufenacil are proposed for registration in the United 

States. These include BAS 800 04H (FiRoCrop; 29.74% a.i.), an aqueous suspension 

concentrate (SC) for agricultural crop and fallow land uses; BAS 804 00H (LegVeg; 17.80% 

a.i.), a water soluble granule (WG) containing 50.20% imazethapyr and for agricultural uses; 

BAS 781 02H (6.24% a.i.), an emulsifiable concentrate (EC) containing 55.04% dimethenamid-P 

and for agricultural uses; BAS 800 01H (TNV; 70.0% a.i.), a water soluble granule (WG) for 

orchard and vineyard uses; and BAS 800 02H (SharpenTM; 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; SharpenTM), 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. 
4

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 grainsd0.13 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
5

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 

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.

Grape vines 0.022 0.066 Equipment: ground.

BAS 800 

02H 

(SharpenTM)

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.
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3.2. Fate and Transport Characterization

Saflufenacil [N’-[2-chloro-4-fluoro-5-(3-methyl-2,6-dioxo-4-(trifluoromethyl)-3,6-

dihydro-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 microbiallyinfluenced 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-m

3

/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
7

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

Parameter Value Source

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.

3.2.1. 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).

3.2.2. 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 
8

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 
9

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 halflives 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).

3.2.3. 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 
10

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 
11

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.

3.2.4. 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 atmm

3

/mol and a vapour pressure of 3.5 x 104torr 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 
12

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).

3.2.5. 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.
13

3.3. Drinking Water Exposure Modeling

3.3.1. 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.
14

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.

3.3.2. 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

(SharpenTM formulation).

Water Table

Lateral Groundwater

Movement

100 cm

Set back distance

Biodegradation 

Zone 100 cm

Abiotic

Degradation

Pesticide Application Area

Potable Well

Depth to 

Water 

Table

Water Table

Lateral Groundwater

Movement

100 cm

Set back distance

Biodegradation 

Zone 100 cm

Abiotic

Degradation

Pesticide Application Area

Potable Well

Depth to 

Water 

Table
15

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. 
16

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 halflife 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 nonagricultural 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 halflife 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 
17

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 postharvest 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.

Maturity Date Jan. 2 (none) nd

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
18

3.3.3. Modeling Results

Screening estimates generated for drinking water exposure assessment are listed in Table 

9. The proposed use pattern for the SharpenTM formulation for use on tree plantations and nonagricultural 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.
19

Figure 2. Exposure estimates of saflufenacil in Delmarva ground water over thirty years,

generated with PRZM GW and a provisional non-agricultural scenario.

3.3.4. 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.

4. 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).

0

20

40

60

80

100

120

140

160

180

200

1/1/1961 6/24/1966 12/15/1971 6/6/1977 11/27/1982 5/19/1988

Date

E

D

W

C (ppb)
20

5. 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: 

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: 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: 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: http://soildatamart.nrcs.usda.gov/

USDA. 2009a. Soil Characterization Database. U.S. Department of Agriculture, Natural Resources Conservation 

Service. Online at: 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: 

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: 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: http://www.epa.gov/ceampubl/tools/metdata/index.html
21

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: http://toxnet.nlm.nih.gov/

5.1. 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.
22

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.
23

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

Table I.1. Saflufenacil and Its Major Organic Environmental Degradates.

Code Name/ 

Synonym Chemical Name Chemical Structure Study Type Maximum %AR (day)

Final %AR 

(study length)

PARENT

Saflufenacil

BAS 800H

IUPAC: N′-{2-Chloro-4-fluoro-5-

[1,2,3,6-tetrahydro-3-methyl-2,6-

dioxo-4-(trifluoromethyl)pyrimidin1-yl]benzoyl}-N-isopropyl-Nmethylsulfamide

CAS: 2-Chloro-5-[3,6-dihydro-3-

methyl-2,6-dioxo-4-

(trifluoromethyl)-1(2H)-

pyrimidinyl]-4-fluoro-N-

[[methyl(1-methylethyl)amino] 

sulfonyl]benzamide

CAS-no: 372137-35-4

Formula: C17H17ClF4N4O5S

MW: 500.86 g/mol

O

N

H

S

N

CH3

H3C

O

O

N

CH3

F

O

N O

CH3

Cl

F

F

F

MAJOR (>10%) TRANSFORMATION PRODUCTS

M01

M800H01

N’-[2-Chloro-4-fluoro-5-(3-methyl2,6-dioxo-4-(trifluoromethyl)-3,6-

dihydro-1(2H)-

pyrimidinyl)benzoyl]-N’-

isopropylsulfamide 

Formula: C16H15ClF4N4O5S

MW: 486.83 g/mol

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-dihydro1(2H)-pyrimidinyl)-4-

fluorobenzoyl]-N-isopropyl-Nmethylsulfamide 

Formula: C16H15ClF4N4O5S

MW: 486.83 g/mol

O

N

H

S

N

CH3

H3C

O

O

N

CH3

F

O

N

H

O

Cl

F

F

F

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)

O

N

H

S

NH

H3C

O

O

N

CH3

F

O

N O

CH3

Cl

F

F

F
24

Code Name/ 

Synonym Chemical Name Chemical Structure Study Type Maximum %AR (day)

Final %AR 

(study length)

M04

M800H04

Formula: C17H19ClF4N4O6S

MW: 518.87 g/mol

O

N

H

S

N

CH3

H3C

O

O

HN

CH3

F

O

N O

CH3

Cl

F

F

F

HO

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

MW: 380.83 g/mol

O

N

H

S

N

CH3

H3C

O

O

HN

CH3

F

N

H

H3C

O

Cl

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-methyl2,6-dioxo-4-(trifluoromethyl) 

tetrahydro-1(2H)-pyrimidinyl) 

benzoyl]-N-isopropyl-Nmethylsulfamide

Formula: C17H19ClF4N4O5S

MW: 502.88 g/mol

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)

O

N

H

S

N

CH3

H3C

O

O

N

CH3

F

O

N O

CH3

Cl

F

F

F
25

Code Name/ 

Synonym Chemical Name Chemical Structure Study Type Maximum %AR (day)

Final %AR 

(study length)

M15

M800H15

N-{4-Chloro-2-fluoro-5-

[({[isopropyl (methyl) amino] 

sulfonyl} amino) carbonyl] 

phenyl}-4-4-4-trifluoro-3,3-

dihydroxybutanamide 

Formula: C15H18ClF4N3O6S

MW: 479.84 g/mol

O

N

H

S

N

CH3

H3C

O

O

HN

CH3

F

O

Cl

F

F F

HO

OH

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)

nd

1

(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]sulfon

yl}amino)carbonyl]anilino}carbony

l)(methyl)amino]-4,4,4-

trifluorobutanoic acid 

Formula: C17H21ClF4N4O6S

MW: 520.89 g/mol

O

N

H

S

N

CH3

H3C

O

O

HN

CH3

F

N O

CH3

Cl

F

F

F

O

HO

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

MW: 127.07 g/mol N

H

O

F

F

F CH3

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
26

Code Name/ 

Synonym Chemical Name Chemical Structure Study Type Maximum %AR (day)

Final %AR 

(study length)

M29

M800H29

TFA

(also 

formulated 

as TFA, 

sodium salt)

Trifluoroacetic acid 

Formula: C2HF3O2

MW: 114.02 g/mol

OH

O

F

F

F

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

MW: 215.13 g/mol OH

N O

CH3

F

F

F

O

HO

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

MW: 112.05 g/mol

CH3

O

F

F

F

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
27

Code Name/ 

Synonym Chemical Name Chemical Structure Study Type Maximum %AR (day)

Final %AR 

(study length)

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

CAS-no: 374-01-6

Formula: C3H5F3O

MW: 114.07 g/mol

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

O

N

S

NH

H3C

O

O

N

CH3

F

O

N O

CH3

Cl

F

F

F

OH

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 (uracillabeled) 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.

CH3

OH

F

F

F
28

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-methyl2,6-dioxo-4-

(trifluoromethyl)tetrahydro-1(2H)-

pyrimidinyl)benzoyl]-N’-

isopropylsulfamide

Formula: C16H17ClF4N4O5S

MW: 488.85 g/mol

O

N

H

S

NH

H3C

O

O

N

CH3

F

O

N O

CH3

Cl

F

F

F

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]-Nisopropylsulfamide

Formula: C15H13ClF4N4O5S

MW: 472.81 g/mol

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

MW: 479.84 g/mol

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

MW: 366.80 g/mol

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

O

N

H

S

NH

H3C

O

O

N

CH3

F

O

N

H

O

Cl

F

F

F

O

N

H

S

N

CH3

H3C

O

O

N

H

CH3

F

O

Cl

F

F

F

HO

OH

O

N

H

S

NH

H3C

O

O

HN

CH3

F

N

H

H3C

O

Cl
29

Code Chemical name Chemical structure Study Type Maximum 

%AR (day)

Final %AR 

(study length)

M24

M800H24

(2E)-3-({[4-Chloro-2-fluoro-5-

({[(methylamino)sulfonyl] 

amino}carbonyl)aniline]carbonyl}ami

no)-4,4,4-trifluoro-2-butenoic acid 

Formula: C13H11ClF4N4O6S

MW: 462.77 g/mol

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

MW: 365.67 g/mol

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)-

pyrimidinyl)-4-fluorobenzoyl]-N’-

isopropylsulfamide 

Formula: C15H15ClF4N4O5S

MW: 474.82 g/mol

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-methyl2,6-dioxo-4-

(trifluoromethyl)tetrahydro-1(2H)-

pyrimidinyl)benzoyl]-N’-

methylsulfamide

Formula: C14H13ClF4N4O5S

MW: 460.79 g/mol

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

O

N

H

S

N

H

CH3

O

O

HN

F

N

H

O

Cl

F

F

F

O

HO

O

NH2

N

O

N O

CH3

Cl

F

F

F

F

O

N

H

S

NH

H3C

O

O

N

CH3

F

O

N

H

O

Cl

F

F

F

O

N

H

S

N

H

CH3

O

O

N

F

O

N O

CH3

Cl

F

F

F
30

Code Chemical name Chemical structure Study Type Maximum 

%AR (day)

Final %AR 

(study length)

M30

M800H30

2-Chloro-4-fluoro-5-(3-methyl-2,6-

dioxo-4-(trifluoromethyl)tetrahydro1(2H)-pyrimidinyl)benzamide 

Formula: C13H10ClF4N3O3

MW: 367.69 g/mol

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

MW: 352.77 g/mol

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

MW: 351.65

O

NH2

N

F

O

N

H

O

Cl

F

F

F

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

MW: 480.88 g/mol

O

N

H

S

N

CH3

H3C

O

O

N

CH3

O

N O

CH3

Cl

HO F

F

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

O

NH2

N

F

O

N O

CH3

Cl

F

F

F

O

N

H

S

NH

H3C

O

O

HN

CH3

F

H2N O

Cl
31

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.) 

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

 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
32

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
33

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
34

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