UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON D.C., 20460 

MEMORANDUM 

DATE: November 15, 2012 

SUBJECT: 

FROM: 

THRU: 

TO: Jose Gayoso, Chemical Review Manager 

Kevin Costello, Chief 

Risk Management and Implementation Branch 2 

Pesticide Reevaluation Division (7508P) 

OFFICE OF 

CHEMICAL SAFETY AND 

POLLUTION PREVENTION 

The Environmental Fate and Effects Division (EFED) has completed the preliminary problem 

formulation (attached) for the ecological risk, environmental fate, and endangered species · 

assessments to be conducted as part of the Registration Review of foramsulfuron. This 

document is intended to provide an overview of what is currently known regarding the 

environmental fate and ecological effects associated with foramsulfuron and its degradation 

products, and outlines uncertainties regarding attributes of the parent compound and its 

transformation products. It describes the preliminary ecological risk hypothesis and the processes 

that will be used during the completion of the ecological risk assessment in support of 

Registration Review. 

1 
2

1. INTRODUCTION 

Foramsulfuron is a sulfonylurea herbicide used to control annual and perennial grasses and 

broadleaf weeds. Foramsulfuron slows or stunts plant growth (or causes ultimate plant death) by 

limiting amino acid synthesis in plants through inhibition of acetolactate synthase (ALS). The 

structure of foramsulfuron, as well as the chemical name and other identifiers are provided in 

Table 1. 

Table 1. Foramsulfuron Chemical Identifiers

Parameter Identifier 

Chemical Structure 

Chemical Name 

N,N-dimethyl-2-[3-(4,6-dimethoxypyrimidin-2-yl)ureidosulfonyl-4]- 

formylaminobenzamide 

2-[3-(4,6-Dimethoxy-2-pyrimidinyl)ureidosulfonyl]-4-(formamido)-N,Ndimethylbenzamide 

SMILES COc2cc(OC)nc(NC(=O)NS(=O)(=O)c1ccc(NC=O)cc1C(=O)N(C)C)n2 

CAS Number 173159-57-4 

Company Code AE F130360 

In addition to the technical product (Reg. No. 264-688), there are four end-use products that 

contain foramsulfuron: Revolver Herbicide (Reg. No. 432-1266), Tribute WG (Reg. No. 432-

1519), Tribute Solo WB32 Herbicide (Reg. No. 264-686), and Option® Corn Herbicide (Reg. 

No. 264-685). A safener ingredient, isoxadifen-ethyl, is included in some of the formulations 

(Reg. Nos. 264-686 and 264-685) to protect the sprayed field corn from damage. Tribute Solo 

WB32 Herbicide contains an additional active ingredient, iodosulfuron-methyl-sodium. Tribute 

WG contains two additional active ingredients, thiencarbazone-methyl (PC15804) and 

halosulfuron-methyl (PC 128721). A summary of all the foramsulfuron formulated products is 

provided in Table 2. 

Table 2. Foramsulfuron Formulated Products

Product EPA Registration 

Number 

Amount Active Ingredient 

(Product Code) 

Tribute Solo WB32 

Herbicide 264-686 

30.0 % foramsulfuron (122020) 

 2.0% iodosulfuron-methyl-sodium 

(122021) 

Option® Corn Herbicide 264-685 35.0% foramsulfuron (122020) 

Tribute WG 432-1519 

19.8% foramsulfuron (122020) 

9.9% thiencarbazone-methyl (15804) 

30.8% halosulfuron-methyl (128721) 

Revolver Herbicide 432-1266 2.34% foramsulfuron (122020) 
3

Based on the usage report prepared by OPP’s Biological and Economic Analysis Division, less 

than 20,500 pounds of foramsulfuron is used on corn per year.1 No usage data are available for 

sod farms or non-agricultural use sites such as residential turf or golf courses. All currently 

registered uses of foramsulfuron are listed in Table 3. 

 

1

 Screening Level Usage Assessment Jan. 10, 2012. 
4 

Table 3. Currently Registered Foramsulfuron Uses

Crop/Site 

(Reg. No.) 

Timing; 

Application 

Type 

Method/ 

Equipment 

Maximum Single 

Application Rate 

Range 

Maximum 

Application 

Rate Per 

Year

(lb a.i./A) 

Maximum 

Application 

Number 

Preharvest 

Interval 

(days) 

Reentry Interval 

(REI) 

Minim

Retreat

Inter

(day

Field, Sweet, 

and Pop 

Corn 

(264-686, 

264-685) 

foliar; 

broadcast 

aircraft, 

ground boom 0.038 lb a.i./A 0.076 2 45 d (forage) 70 d (grain) 12 h NS 

Golf Course 

Turf* 

(432-1266, 

432-1519) 

broadcast ground boom 0.0516 lb a.i./A NS NS NA NS NS 

spot 

treatment handheld 0.0029 lb a.i./gal cannot be determined NS NA NS NS 

Commercial/

Industrial 

Lawns* 

(432-1266, 

432-1519) 

broadcast ground boom 0.0516 lb a.i./A NS NS NA NS NS 

spot 

treatment handheld 0.0029 lb a.i./gal cannot be determined NS NA NS NS 

Ornamental 

lawns and 

turf* 

(432-1266, 

432-1519) 

broadcast ground boom 0.0516 lb a.i./A NS NS NA NS NS 

spot 

treatment handheld 0.0029 lb a.i./gal cannot be determined NS NA NS NS 

Recreation 

area lawns* 

(432-1266, 

432-1519) 

broadcast ground boom 0.0516 lb a.i./A NS NS NA NS NS 

spot 

treatment handheld 0.0029 lb a.i./gal cannot be determined NS NA NS NS 

Residential 

lawns* 

(432-1266, 

432-1519) 

broadcast ground boom 0.0516 lb a.i./A NS NS NA NS NS 

spot 

treatment handheld 0.0029 lb a.i./gal cannot be determined NS NA NS NS 

*There is uncertainty with the maximum application rate per year for EPA Reg. No. 432-1266.
5 

1. PREVIOUS RISK ASSESSMENTS 

Three ecological risk assessments have been completed for foramsulfuron: the new chemical assessment 

(field corn; D267565; February 25, 2002), a label amendment assessment (corn; D311844; October 3, 

2005), and a new use assessment (popcorn, sweet corn; D324203; September 21, 2006). EFED 

evaluated these assessments for foramsulfuron in association with the current toxicity, exposure, and 

usage information to determine if sufficient data are available and if further updates are needed to 

support registration review. 

Potential direct risk to terrestrial and aquatic vascular and non-vascular plants from the use of 

foramsulfuron is expected. There is also the potential for various indirect effects on non-target animal 

species due to the effects on the plant community (for example, depletion of food sources and habitat).

Potential risk was identified from both aerial applications and potentially through irrigation water that 

has received foramsulfuron runoff. The major conclusions presented in the new chemical assessment 

for foramsulfuron are summarized in Table 4 and are briefly discussed in the subsections below. 

Table 4. Summary of Risk Concerns Identified for Foramsulfuron in Previous Assessments

Birds Mammals Terrestrial 

Plants 

Terrestrial 

Inverts Fish Aquatic Inverts 

Aquatic 

Plants 

Groundwater 

Contamination Persistence Degradates of Concern 

-- -- √ -- -- -- √ √ √ -- 

To date, an ecological risk assessment has not been conducted to assess applications made to lawns and 

golf courses (EPA Reg. Nos. 432-1266 and 432-1519). At the time of considering the registration of 

these uses, the ecological exposure and associated potential risks from the proposed use on turf were 

expected to be comparable to the existing uses on corn (i.e., application rates and timing are similar). 

All registered uses will be considered as part of the registration review risk assessment. 

Previous Drinking Water Assessments 

A drinking water assessment (DWA) was conducted at the time of the new chemical assessment, and 

updated with each subsequent new use, as highlighted in Table 5. The uses assessed include 

applications made to field, sweet and pop corn. At this time, the Health Effects Division reports no risk 

concerns associated with dietary exposures resulting from potential foramsulfuron residues that may 

occur in drinking water sources. Therefore, a revised DWA in support of registration review is not 

planned at this time; however, this may be reconsidered if EPA determines a new DWA is warranted. 

Table 5. Foramsulfuron Drinking Water Assessment Summary 

Assessment Crop 

Tier II Surface Water 

Peak 

Concentration 

μg/L (ppb)

Yearly 

Concentration 

Mean μg/L (ppb)

Average of Yearly 

Concentration 

μg/L (ppb)

D267565/DWA New 

Chemical Field Corn1 

1 0.3 0.2 

Tier I Groundwater 

Peak Concentration 

μg/L (ppb) 

Yearly Mean Concentration 

μg/L (ppb) 

D311844/DWA Label 

Amendment Corn1 

0.05 0.05 D324203/DWA New 

Use Sweet Corn and Popcorn1

1. 2 aerial applications per year at 0.0365 lb a.i./a 14 days apart 
6

Clean Water Act Programs 

Foramsulfuron is not identified as a cause of impairment for any water bodies listed as impaired under 

section 303(d) of the Clean Water Act. No Total Maximum Daily Load (TMDL) criteria have been 

developed for foramsulfuron. Aquatic Life Ambient Water Quality Criteria documents or Aquatic life 

benchmarks have not been published for foramsulfuron. 

2. ENVIRONMENTAL FATE AND TRANSPORT 

Physical and Chemical Properties of Foramsulfuron 

The physicochemical properties of foramsulfuron are shown in Table 6. Based on these properties 

alone, foramsulfuron is not expected to be volatile or to bioaccumulate. It is highly soluble in water. 

Solubility has been shown to increase at higher pHs. 

Table 6. Selected Physical/Chemical Parameters of Foramsulfuron 

Parameter Value Source/Classification

Molecular mass (molecular formula) 452.3 g/mol ( C17H2O7N6S) Calculated using EPI Suite

Vapor pressure (20°C) Less than the detection 

limit (10-5 hPa) at 100 °C MRID 45109311 

Aqueous solubility (20C)

37 mg/L (pH 5) 

3290 mg/L (pH 7) 

94600 mg/L (pH 9) 

45109321 

Log octanol-to-water partition coefficient

(log KOW)

-0.82 

-0.78 

Calculated using EPI Suite 

KOWWIN v.1.67 estimate

Environmental Fate Properties of Foramsulfuron 

Environmental fate properties of foramsulfuron are summarized in Table 7. These parameters have been 

updated from previous assessments to reflect the NAFTA degradation kinetics guidance.2 The updated 

kinetic analyses are presented in APPENDIX A. The results are similar to those previously reported in 

the data evaluation records (DERs). For many studies, the DERs indicated that foramsulfuron 

transformation could not always be adequately described using single first order kinetics. This is 

consistent with the current kinetic analyses. 

Foramsulfuron is susceptible to microbial mediated degradation in soil as well as in aquatic 

environments. Hydrolysis of foramsulfuron is pH dependent with the increased hydrolysis occurring 

under acidic conditions. Photodegradation in aquatic environments is not expected for foramsulfuron. 

No acceptable data are available on the photodegradation of foramsulfuron in soil. Foramsulfuron is 

expected to be mobile in soil. In summary, foramsulfuron is likely to leach to groundwater and runoff or 

drift during application to surface water. 

 

 

2 Guidance for Evaluating and Calculating Degradation Kinetics in Environmental Media, Health Canada, U.S. 

Environmental Protection Agency, December 2012. 
7

Table 7. Environmental Fate Parameters of Foramsulfuron 

Parameter Value Source/Classification

Persistence

Hydrolysis half-life (25C) pH 4: 5 d pH 5: 11 d 

pH 7: 156 d pH 9: 176 d 

MRID 45109324/ 

supplemental1 

Aqueous photolysis half-life (25C) Stable MRID 45109325/ 

acceptable 

Soil photolysis half-life (25C) -- no acceptable 

data available

Aerobic soil metabolism half-life (25°C) 

DT50=8.1 days; DT90=85.9 days; 

tR IORE = 25.8 d (US, North Carolina loamy 

sand) MRID 45109714/ 

Acceptable4

DT50=10.7 days; DT90=128 days; 

tR IORE = 38.6 d (US, Iowa silty clay loam) 

Aerobic soil metabolism half-life (20°C) 

DT50=10 days; DT90=54.4 days; 

tR IORE = 16.4 d2

 (EU3) 

MRID 45109713/ 

Acceptable 

DT50=1.3 days; DT90=11.3 days; 

tR IORE = 3.4 d (EU3

) 

DT50=3.4 days; DT90=38.6 days; 

tR IORE = 11.6 d (EU3

) 

Anaerobic aquatic metabolism half-life (20°C) 

t1/2=37.7 d (total system) 

42.4 d (total system w/out hydrolysis) 

t1/2= 25.8 d (water) 

t1/2= 28.0 d (water w/out hydrolysis) 

MRID 45109729/ 

Reclassified 

to Supplemental5 

Anaerobic aquatic metabolism half-life (10°C) 

t1/2=72.1 d (total system) 

DT50=42.8 days; DT90=182 days; 

tR IORE = 54.7 (water) 

MRID 45109730/ 

Reclassified 

to Supplemental5

Aerobic aquatic metabolism half-life 

[dissipation half-life (25C) 

t1/2=28.5 d (total system) 

t1/2=14.8 d (water) 

45109728/ 

Reclassified 

to supplemental5 

Mobility

Freundlich soil-water partition coefficients 

(KF); organic carbon-normalized Freundlich 

coefficients (KFOC) 

2.6, 0.42,0 .91, 0.31, 1.2 L/kg; 

151, 89, 51, 38, 63 L/kgOC

MRID 45109723/ 

Acceptable 

Leaching in Outdoor Lysimiters 

Supports leaching as a possible dissipation 

route; however, the study suggests that a 

complete mass balance transfer is unlikely. 

MRID 45109721/ 

Supplemental 

Field Dissipation 

Terrestrial field dissipation half-life; leaching 

depth 

t1/2=11 d (New York) 

t1/2=13 d (Missouri) 

t1/2=18 d (west Ontario) 

t1/2=13 d (east Ontario) 

MRID 45109722/ 

supplemental 

Prospective Groundwater 

Study suggests leaching is possible; however, 

it indicates that the total mass (foramsulfuron 

and environmental transformation products) 

applied is not likely to leach through the soil 

profile. 

45721301 

Fish Bioconcentration

Fish bioconcentration factor (steady-state); 

depuration rate -- No data available 
8

Parameter Value Source/Classification

1. Replicate samples were not prepared and it was not specified if the samples were incubated in the dark. 

2. Notable transformation was observed in the sterile control. Hydrolysis is expected to contribute to the 

transformation rate as the soil pH is ~5. The use of the tR IORE value from the non-sterile sample provides a 

more conservative half-life value than subtracting the two SFO rates and then calculating the corresponding halflife value. Transformation is best represented by a two compartment model such as IORE. 

3. No soil taxonomic information is provided; therefore, a comparison between the European soils used in this study 

cannot be made to be representative use sites in the US. In addition, the soil pH reported is slightly acidic. 

Additional hydrolysis may account for the difference between the half-life values calculated for the US and EU 

soils. 

4. Kinetic analysis is provided in APPENDIX A. 

5. There is a large amount unknown radioactive residues present in the water fractions. There is also a large amount 

of non-extracted residues. For these reasons, this study has been reclassified to supplemental. 

Transformation Products 

Several major foramsulfuron transformation products were reported in the submitted environmental fate 

studies. These major transformation products as well as a few minor degradates are listed in Table 8

with the maximum amounts of each chemical formed in the various studies. In both of the anaerobic and 

aerobic aquatic metabolism studies submitted to EPA, a large amount of the applied radioactivity was 

either not extracted or not identified, a major study deficiency. 

A few environmental fate studies, mainly mobility studies, have been submitted for the foramsulfuron 

transformation products. These data are summarized in Table 9. The results suggest that foramsulfuron 

transformation products, AEF153745 and AEF130619 are likely as mobile as foramsulfuron in the soil 

profile; however, AEF092944 is likely less mobile than foramsulfuron in the soil profile. 
9 

Table 8. Foramsulfuron Environmental Transformation Products 

Code Name/ 

Synonym Chemical Name Chemical Structure Study Type Ref. (MRID) Maxi

%AR 

MAJOR 

AEF130619 

4-amino-2-(N-((4,6-dimethoxypyrimidin-2-yl)carbamoyl)sulfamoyl)-N,Ndimethylbenzamide4-amino-2-[3-(4,6-dimethoxypyrimidin-2-yl)ureidosulfonyl]-N,Ndimethylbenamide Formula: C16H20N6O6S

MW: 424.43 g/mol

Hydrolysis (pH 4 

@ 25 °C) 

45109324/ 

Supplemental

2.6 (10 

lab

Hydrolysis (pH 7 

@ 25 °C) 

45109324/ 

Supplemental

9.1 (30 

lab

Hydrolysis (pH 9 

@ 25 °C) 

45109324/ 

Supplemental

7.6 (30 

lab

Aerobic Soil 45109714/ acceptable 10.4 Aerobic Soil 45109713/ acceptable 30.8 

Anaerobic 

Aquatic 

45109729/ 

supplemental

1.2 (

total 

AEF153745 

4-Formylamino-N,Ndimethyl-2-sulfamoylbenzamide Formula: C10H13N3O4S

MW: 271.29 g/mol

NH

S NH2

O O

N

O

O

Hydrolysis (pH 4 

@ 25 °C) 

45109324/ 

Supplemental 66.3 

Hydrolysis (pH 5 

@ 25 °C) 

45109324/ 

Supplemental 71.3 

Hydrolysis (pH 7 

@ 25 °C) 

45109324/ 

Supplemental 3.3 

Hydrolysis (pH 9 

@ 25 °C) 

45109324/ 

Supplemental 4.1 

Aerobic Soil 45109714/ acceptable 5.0 Aerobic Soil 45109713/ acceptable 7.8 

Anaerobic 

Aquatic 

45109729/ 

supplemental

8.2 (

total 
10

Code Name/ 

Synonym Chemical Name Chemical Structure Study Type Ref. (MRID) Maxi

%AR 

AEF092944 

4,6-dimethoxypyrimidin-2-amine 2-amino-4,6-dimethoxypyrimidine Formula: C6H9N3O2

MW: 155.15 g/mol

Hydrolysis (pH 4 

@ 25 °C) 

45109324/ 

Supplemental 79.7 

Hydrolysis (pH 5 

@ 25 °C) 

45109324/ 

Supplemental 83.3 

Hydrolysis (pH 7 

@ 25 °C) 

45109324/ 

Supplemental 4.7 (

Hydrolysis (pH 9 

@ 25 °C) 

45109324/ 

Supplemental 1.9 (

Aerobic Soil 45109714/ acceptable 17.8 Aerobic Soil 45109713/ acceptable 16.9 

TFD 45109722/ supplemental 5.06 μg

F0338795 

Formula: C16H18N6O7S

MW: 438.42 g/mol N

H

S NH

NH

N

N

O O

N

O

O

O OH

O

Anaerobic 

Aquatic 

45109729/ 

supplemental 17.0 (

Unknowns 

Aerobic Aquatic 45109728/ supplemental 28.6 

total 

4.6 (5

Anaerobic 

Aquatic 

45109729/ 

supplemental

53.4 (

total 

13.8 (

Non-extracted Residues 

Aerobic Aquatic 45109728/ supplemental 75.4 (

total 

Anaerobic 

Aquatic 

45109729/ 

supplemental

26.0 (

total 
11

Code Name/ 

Synonym Chemical Name Chemical Structure Study Type Ref. (MRID) Maxi

%AR 

MINOR

AEF148003 

4-amino-N,N-dimethyl2-sulfamoyl-benzamide Formula: C9H13N3O3S 

MW: 243.28 g/mol H2N S NH2

O

N

O

O

Hydrolysis (pH 4 

@ 25 °C) 

45109324/ 

Supplemental 5.6 (

Hydrolysis (pH 5 

@ 25 °C) 

45109324/ 

Supplemental 3.0 (

Aerobic Soil 45109714/ acceptable 2.2 (Aerobic Soil 45109713/ acceptable 0.9 (10

AEF0014940 

6-formamido-1,2-benisothiasol-3(2H)-one 1, 1-dioxide N-(1,1,3-Trioxo-2,3-dihydro-1H-1l6-benzo[d]isothiazol-6-yl)-formamide Formula: C8H6N2O4S 

MW: 226.21 

NH

S NH

O O

N

O

O

Hydrolysis (pH 4 

@ 25 °C) 

45109324/ 

Supplemental 7.9 (

Hydrolysis (pH 5 

@ 25 °C) 

45109324/ 

Supplemental 9.7 (

AEF0001082 

6-amino-1,1-dioxo-1,2-dihydro-1l6-benzo[d]isothiazol-3-one6-amino-1,2-benzisothiasol-3(2H)-one 1,1-dioxide, potassium salt Formula:C7H6N2O3S 

MW: 198.20

H2N S

NH

O

O O

Hydrolysis (pH 4 

@ 25 °C) 

45109324/ 

Supplemental 1.1 (
12

Code Name/ 

Synonym Chemical Name Chemical Structure Study Type Ref. (MRID) Maxi

%AR 

AEF099095 

(4,6-Dimethoxypyrimidin-2-yl)-urea Formula:C7H10N4O3

MW: 198.18 

NH2

NH

N

N

O

O

O

Aerobic Soil 45109713/ acceptable 0.8 (

Bold font indicates the highest percentage observed for a given transformation product. MW: molecular weight * Largest single unknown; it is unclear if the residues cited are the same. 
13 

Table 9. Environmental Fate Parameters of Foramsulfuron Transformation Products 

Transformation 

Product Parameter Value Source/ 

Classification 

Mobility 

AEF130619 

Freundlich soil-water partition 

coefficients (KF); organic carbonnormalized Freundlich coefficients 

(KFOC)

1.90, 0.36, 0.79, 2.98 L/kg;

63, 44, 40, 144 L/kgOC

MRID 45109725/ 

acceptable 

AEF153745 

Freundlich soil-water partition 

coefficients (KF); organic carbonnormalized Freundlich coefficients 

(KFOC) 

0.51, 1.43, 1.49, 0.99 L/kg;

63, 35, 50, 48 L/kgOC

MRID 45109724/ 

acceptable 

AEF092944

Freundlich soil-water partition 

coefficients (KF); organic carbonnormalized Freundlich coefficients 

(KFOC) 

2.47, 2.59, 8.25, 1.05, 1.82, 4.11, 

81.30, 16.50 L/kg;

211, 89, 625, 663, 696, 395, 

11289, 917 L/kgOC

MRID 45109726/ 

acceptable 

Safener 

Isoxadifen-ethyl, the safener included in corn use formulations (Reg. Nos. 264-686 and 264-685) of 

foramsulfuron, is reported to be at concentrations approximately equivalent to foramsulfuron concentrations; 

therefore, the field application rate is expected to be the same (0.038 lb a.i./A). Chemical identifiers for 

isoxadifen-ethyl are included in Table 10. Limited environmental fate data for isoxadifen-ethyl is provided in 

Table 11. Isoxadifen-ethyl is expected to be slightly mobile and has the potential to bioaccumulate. 

Table 10. Isoxadifen-ethyl Chemical Identifiers 

Parameter Identifier 

Chemical Structure 

N

O

O O

Chemical Name ethyl 4,5-dihydro-5,5-diphenyl-1,2-oxazole-3-carboxylate 

ethyl 4,5-dihydro-5,5-diphenyl-3-isoxazolecarboxylate 

SMILES C1(C(OCC)=O)=NOC(C1)(c1ccccc1)c1ccccc1 

CAS Number 163520-33-0 

Table 11. Physical/Chemical Parameters of Isoxadifen-ethyl 

Parameter Value Source/Classification

Molecular mass (molecular formula) 295.34 g/mol (C18H17O3N) Calculated using EPI Suite

Vapor pressure (20°C) 6.79 x 10-5Pa Calculated using EPI Suite

Modified Grain Method 

Aqueous solubility (20C) 1.26 mg/L MRID 44739133 

(algal toxicity study) 
14

Parameter Value Source/Classification

Log octanol-to-water partition coefficient 

(log KOW) 5.66 Calculated using EPI Suite 

KOWWIN v.1.67 estimate

Koc 9777 L/kg Calculated using EPI Suite

Kow method 

Hydrolysis stable Calculated using EPI Suite

3. RECEPTORS 

Table 12 and Table 13 provide a summary of the aquatic and terrestrial taxonomic groups, respectively, and the 

most sensitive surrogate species tested to characterize the potential acute and chronic ecological effects of 

foramsulfuron. The tables provide a preliminary overview of the potential acute toxicity of foramsulfuron by 

providing the acute toxicity classifications. Based on the available ecotoxicity information, the organisms facing 

the greatest hazard are aquatic and terrestrial plants. No toxicity data were submitted or identified in the open 

literature for the foramsulfuron transformation products. However, some toxicity data are available from other 

sulfonylurea chemicals that share common degradates, and are discussed in detail below. 

Table 12. Summary of the Most Sensitive Endpoints from Aquatic Toxicity Studies for Foramsulfuron 

Taxonomic 

Group 

Study 

Type 

Surrogate Species 

and 

Test Material 

Toxicity Value 

(all units in terms of 

measured active 

ingredient) 

MRID and 

Classification 

Acute 

Toxicity 

Classification 

Freshwater fish1

Acute 

Rainbow Trout 

(Oncorhynchus 

mykiss) 

TGAI 

LC50 = >100 mg a.i./L 

Most sensitive endpoint: 

none 

No sublethal effects 

reported. 

45109903 

Acceptable 

Practically 

nontoxic 

Chronic 

(Early 

Life 

Stage) 

Fathead Minnow 

(Pimephales 

promelas) 

TGAI 

NOAEC = 10.5 mg 

a.i./L 

LOAEC = >10.5 mg 

a.i./L 

Most sensitive endpoint: 

none 

No sublethal effects 

reported. 

46241301 

Acceptable -- 

Estuarine/Marine 

fish Acute 

Sheepshead 

Minnow 

(Cyprinodon 

variegatus) 

TGAI 

LC50 = >93.6 mg a.i./L 

Most sensitive endpoint: 

none 

No sublethal effects 

reported. 

45109927 

Acceptable Slightly toxic 

Freshwater 

invertebrates Acute 

Water Flea 

(Daphnia magna) 

TGAI 

EC50 = >102.5 mg a.i./L 

Most sensitive endpoint: 

none 

No sublethal effects 

reported. 

45109906 

Supplemental 

Classification 

based on water 

quality deviations 

from 850 

guideline 

recommendations. 

Practically 

nontoxic 
15

Taxonomic 

Group 

Study 

Type 

Surrogate Species 

and 

Test Material 

Toxicity Value 

(all units in terms of 

measured active 

ingredient) 

MRID and 

Classification 

Acute 

Toxicity 

Classification 

Chronic 

Water Flea 

(Daphnia magna) 

TGAI 

NOAEC = 100 mg a.i./L 

LOAEC = >100 mg 

a.i./L 

Most sensitive endpoint: 

none 

No sublethal effects 

reported. 

45109907 

Acceptable -- 

Estuarine/Marine 

invertebrates 

Acute – 

shell 

deposition 

study 

Eastern Oyster 

(Crassostrea 

virginica) 

TGAI 

EC50 = 118 mg a.i./L 

NOAEC = 13.4 mg 

a.i./L 

45109929 

Acceptable 

Practically 

nontoxic 

Aquatic plants 

and algae 

Nonvascular 

Freshwater 

Cyanobacterium 

(Anabaena flosaquae) 

TGAI 

EC50 = 3.3 mg a.i./L 

NOAEC = < 3.0 mg 

a.i./L 

Endpoint: area under the 

growth curve. 

45109909 

Acceptable -- 

Nonvascular 

Marine Diatom 

(Skeletonema 

costatum) 

TGAI 

EC50 = >105 mg a.i./L 

NOAEC = <105 mg 

a.i./L 

Endpoint: growth rate 

45109930 

Acceptable -- 

Vascular 

Duckweed (Lemna 

gibba) 

TGAI 

EC50 = 0.00065 mg 

a.i./L 

NOAEC = 0.00036 mg 

a.i./L 

Endpoint: area under the 

growth curve. 

45109911 

Acceptable -- 

1. Freshwater fish represent surrogates for aquatic-phase amphibians. 

 
16

Table 13. Summary of the Most Sensitive Endpoints from Terrestrial Toxicity Studies for Foramsulfuron 

Taxonomic 

Group 

Study 

Type 

Surrogate Species 

and 

Test Material 

Toxicity Value 

(all units in terms of 

measured active 

ingredient) 

MRID and 

Classification 

Acute 

Toxicity 

Classification 

Birds1

Acute 

Bobwhite quail 

(Colinus 

virginianus) 

TGAI 

LD50 = >2,000 mg/kg-bw 

Most sensitive endpoint: 

none 

No sublethal effects 

reported. 

45109733 

Acceptable 

Practically 

nontoxic3 

Sub-acute 

dietary 

Mallard Duck 

(Anas 

platyrhynchos) 

TGAI 

LC50 = 

>4438 mg/kg diet 

Most sensitive endpoint: 

none 

No sublethal effects 

reported. 

45109736 

Acceptable 

Practically 

nontoxic3 

Chronic 

Bobwhite quail 

(Colinus 

virginianus) 

TGAI 

NOAEC = 1000 ppm 

LOAEC = >1000 ppm 

Most sensitive endpoint: 

none 

No sublethal effects 

reported. 

45109901 

Supplemental 

Chemical was 

not dissolved 

in carrier for 

preparation of 

food. 

-- 

Mammals 

Acute Oral 

Laboratory rat 

(Rattus 

norvegicus) 

LD50 = >5,000 mg a.i./kg 45109433 

Acceptable 

Practically 

nontoxic3 

Acute 

Inhalation 

Laboratory rat 

(Rattus 

norvegicus) 

LC50 = > 5.04 mg/L 45109435 

Acceptable -- 

Chronic 

Laboratory rat 

(Rattus 

norvegicus) 

NOAEL = 15000 ppm 

LOAEL = ND 

Endpoint: NA 

45109616 

Acceptable 

Practically 

nontoxic3 

Insects 

Acute 

contact 

Honey bee 

(Apis mellifera L.) 

TGAI 

LD50 = >1.9 μg a.i./bee 

No sublethal effects 

reported. 

45109915 

Acceptable 

Moderately 

Toxic2 

Acute Oral 

Honey bee 

(Apis mellifera L.) 

TGAI 

LD50 = >163 μg a.i./bee 

No sublethal effects 

reported. 

45109914 

Acceptable 

Practically 

nontoxic2

Terrestrial plants Vegetative 

Vigor 

Dicot – Radish 

(Raphanus sativus) 

Formulated Corn 

Product 

NOAEC = 0.00005 lbs 

a.i./acre 

IC25 = 0.00010 lbs 

a.i./acre 

Endpoint: Mean Weight 

45483801 

Acceptable -- 

Monocot – Rye 

(Lolium perenne) 

Formulated Corn 

Product 

NOAEC = 0.0004 lbs 

a.i./acre 

EC25 = 0.0014 lbs 

a.i./acre 

Endpoint: Mean Weight 

45483801 

Acceptable -- 

1 Birds represent surrogates for terrestrial-phase amphibians and reptiles. 2

 Based on acute contact LD50 (μg a.i./bee) <2 highly toxic; 2-10.99 moderately toxic; ≥11 practically non-toxic 3 Acute Oral (avian/mammal): Based on LD50 (mg/kg) <10 very highly toxic; 10-50 highly toxic; 51-500 moderately 

toxic; 501-2000 slightly toxic; >2000 practically nontoxic 

 
17

Effects of Foramsulfuron on Plant Reproduction 

EFED's Plant Technical Team (PTT) conducted an analysis of available SU plant reproduction data from the 

open literature and the registrant-submitted data for chlorsulfuron and concluded that data from the vegetative 

vigor guideline (850.4150) study are sufficiently protective of potential impacts to plant reproduction. 

Acetolactate synthase (ALS) inhibitors primarily affect metabolically-active meristem tissues. When plants are 

exposed at a young, vigorously growing life-stage, effects are expressed primarily as inhibition of vegetative 

growth (i.e. biomass, shoot length). As plants mature these effects are less pronounced. However, as plants enter 

their reproductive life-stage, the metabolically active tissue will include flower and seed production. Plants 

exposed to SU herbicides during the reproductive life stage are likely to exhibit adverse effects on reproduction, 

generally expressed as reduced seed number or reduced seed weight. Based on the latest data analysis, these 

effects are expected to occur at similar concentrations to those effects determined in the guideline vegetative 

vigor studies (850.4150) so further data are not requested at this time. 

Degradate Toxicity 

Two degradates AEF130619 and F0338795 contain an intact sulfonyl urea (SU) bridge (-NH-CO-NH-SO2-) 

which has been identified as an important functional structure of SU toxicity thus are considered to have similar 

toxicity to the parent. 

Acute oral toxicity data for AEF092944 (also known as ADMP; and INJ0290) with laboratory rats (LD50 = 836 

mg/kg; MRID 47305226) suggest that this degradate is slightly more toxic than the parent (see Table 13) but is 

considered practically non-toxic. 

The degradate AEF099095 (also known as DOP urea; IR7825; N-(4,6-diethoxypyrimidin-2-yl)urea); and 

UPDM) is practically non-toxic to the laboratory rat (LD50 677 mg/kg, MRID 47305223) on an acute oral basis. 

A preliminary review of the available vascular plant toxicity data for this degradate suggests that it is less toxic 

to vascular plants than the parent (NOAEC >0.3122 lbs/A; MRID 46588504). 

There are no toxicity data available for degradate AEF001082 (aminosaccharin); however, data for saccharin 

suggests similar toxicity to the parent foramsulfuron. 

Safener Toxicity 

Available data suggest that isoxadifen-ethyl (AEF122006), a safener added to formulations intended for corn 

use, is highly toxic to the bluegill (MRID 44739131; LC50 = 0.22 mg/L, NOAEC = 0.09 mg/L) and the rainbow 

trout (MRID 44739130; LC50 = 0.34 mg/L, NOAEC = 0.12 mg a.i./L). Chronic toxicity studies including the 

safener are not available; however, estimated endpoints using ECOSAR (version 1.11) result in chronic toxicity 

concentrations of 8 μg/L for fish and 15 μg/L for invertebrates (APPENDIX D). See the Stressors of Concern

discussion below, which discusses a cursory analysis conducted to assess potential exposure of the safener to 

aquatic animals. 

Ecological Incidents 

A search of the Ecological Incident Information System (EIIS) database showed 45 “Probable” foramsulfuron 

incidents affecting standing corn crops from direct applications, and impacting as much as 400 acres. There 

were also 22 “Possible” incidents affecting as much as 1350 acres of corn crops. 

In the Incident Data System (IDS) database, registrants reported 33 plant incidents associated with 

foramsulfuron use between 2002 and 2011. 
18

A search of the Avian Incident Monitoring System (AIMS) database did not provide any additional incident 

data. 

4. CONCEPTUAL MODEL 

The environmental fate properties of foramsulfuron indicate that direct spray, spray drift, leaching to 

groundwater, and runoff represent potential transport mechanisms. These pathways may result in a wide range 

of potential aquatic and terrestrial exposure scenarios. 

5. ANALYSIS PLAN 

Ecological Risk Assessment 

Stressors of Concern 

The exposure assessments will consider the parent, foramsulfuron, as well as the major degradates listed in 

Table 8 (e.g., AEF130619 and F0338795) using a total toxic residue approach. The transformation products 

AEF130619 and F0338795 contain an intact sulfonyl urea (SU) bridge (-NH-CO-NH-SO2-) which has been 

identified as an important functional structure of SU toxicity. AEF130619 forms under both aerobic and 

anaerobic F0338795; therefore, it will be considered as part of a total toxic residues approach in both the 

terrestrial and aquatic exposure assessments. F0338795 forms under anaerobic aquatic conditions and is also 

assumed to form under anaerobic soil conditions. Therefore, F0338795 will be considered as part of a total toxic 

residue approach for assessing the potential risk to via groundwater irrigation in absence of additional anaerobic 

soil metabolism data. These transformation products will be considered as toxic as the parent unless additional 

toxicity data becomes available. An analysis including the safener AEF122006 will be conducted for corn uses 

only. 

While the toxicity of the safener, isoxadifen-ethyl, to some species including aquatic organisms may be greater 

than the parent, aquatic exposure to the safener at levels of toxicological concern are not expected based on the 

current products registered for use on corn. This was determined by calculating a high-end exposure 

concentration [0.53μg/L (peak)] using the GENEEC (v. 2.0 August 2, 2001)3

. Since the high-end estimated 

exposure concentration is several orders of magnitude less than the most sensitive endpoints (freshwater fish 

acuteLC50 value of 220 μg/L; freshwater invertebrate acute toxicity estimate = 41 μg/L4; fish chronic toxicity 

estimate = 4 μg/L8

), risk is not expected. To confirm this analysis, additional data on the mobility of isoxadifenethyl are recommended, as an estimated Koc value was used in the modeling. Additionally, it is noted that with 

a log KOW of 5.66 5

, this chemical does have the potential to bioaccumulate. 

The results of the GENEEC analysis are provided in APPENDIX E

Measures of Exposure 

In order to estimate risks of foramsulfuron exposure to aquatic and terrestrial organisms, all exposure modeling 

and resulting risk conclusions will be made based on maximum application rates, application methods, and any 

mitigation measures specifically indicated on the label. The models that will be used to predict the estimated 

environmental concentrations (EECs) of foramsulfuron are discussed on OPP’s model website.6

 These models 

 

3

 Modeling assumptions: 2 applications at 0.038 lb/a; 3 d minimum retreatment interval; ground application; high boom; no spray drift 

buffer; fine spray; no incorporation; solubility 1.3 mg/L; Koc = 9777 L/kg; and stable to degradation. 

4

 ECO SAR prediction 

5

 EPI Suite KOWWIN v. 1.67 estimate 

6

 http://www.epa.gov/opp00001/science/models_pg.htm 
19

include: PRZM (Pesticide Root Zone Model) and EXAMS (EXposure Analysis Modeling System), PRZMgroundwater (GW), AgDrift, AgDisp, T-REX, TerrPlant, SIP (Screening Imbibition Program), and STIR 

(Screening Tool for Inhalation Risk). 

The results of running the SIP and STIR models are presented in APPENDIX B and APPENDIX C. While the 

SIP model suggests that there are expected concerns for both mammals and birds, the model does not perform 

well with chemicals that have a high aqueous solubility and have low toxicity to these organisms. This route of 

exposure is not likely to be significant enough to cause concern. The analysis with STIR indicates no presumed 

risk to birds or mammals through inhalation of foramsulfuron. 

Measure of Effects 

Ecological effects data are used as measures of direct and indirect effects to biological receptors. Data are 

typically obtained from registrant-submitted studies or from literature studies identified by ECOTOX. The 

ECOTOX database provides more ecological effects data in an attempt to bridge existing data gaps. ECOTOX 

is a source for locating single chemical toxicity data and potential chemical mixture toxicity data for aquatic 

life, terrestrial plants, and wildlife. ECOTOX was created and is maintained by the USEPA, Office of Research 

and Development, and the National Health and Environmental Effects Research Laboratory's Mid-Continent 

Ecology Division. 

Integration of Exposure and Effects 

Risk characterization is the integration of exposure and ecological effects to determine the potential ecological 

risk from the use of pesticides and the likelihood of direct and indirect effects to non-target organisms in aquatic 

and terrestrial habitats. For the assessment of risks, the risk quotient (RQ) method is used to compare exposure 

and measured toxicity values. EECs are divided by acute and chronic toxicity values. The resulting RQs are 

then compared to the Agency’s Levels of Concern (LOCs) (USEPA 2004). These criteria will be used to 

indicate when foramsulfuron use, as directed on the label, has the potential to cause adverse direct or indirect 

effects to non-target organisms. In addition, incident data from the EIIS, IDS, and AIMS will be considered as 

part of the risk characterization.

Endangered Species Assessments 

Consistent with the Agency’s responsibility under the Endangered Species Act (ESA), the Agency will evaluate 

exposure and potential risks to federally listed threatened and/or endangered (listed) species from registered 

uses of pesticides in registration review. 

6. PRELIMINARY IDENTIFICATION OF DATA GAPS 

Fate 

Table 14 identifies the environmental fate studies submitted by the registrant, as well as study classifications 

and whether or not additional data are needed in order to support the registration review exposure assessments. 

Rationale for the additional data requested is also presented. 
20

Table 14. Submitted Environmental Fate Data for Chemical Foramsulfuron 

OCSPP 

Guideline 

Data 

Requirement 

Submitted 

Studies 

(MRID) 

Study 

Classifications

Are data 

needed to 

conduct risk 

assessment?

Comments 

835.2120 Hydrolysis 45109324 supplemental no 

835.2240 Aqueous 

photolysis 45109325 acceptable no 

835.2410 Soil photolysis yes 

No acceptable study has been submitted.

Foramsulfuron is toxic to plants. 

Knowledge of the persistence of 

foramsulfuron in soil as well as the 

identification of transformation products 

will help the Agency determine and 

estimate exposure of foramsulfuron and 

other residues of potential toxicological 

concern to non-target organisms. The 

results of this study will be used in the 

environmental fate assessment, and later 

on, in the ecological risk 

characterization. 

835.4100 Aerobic soil 

metabolism 

45109714 acceptable 

no 

Additional information on soil 

taxonomy would be helpful; however, it 

is not expected to change the risk 

assessment approach or outcome. 

45109713 acceptable 

835.4200 Anaerobic soil 

metabolism No data no1 

No acceptable study has been submitted. 

Foramsulfuron is toxic to plants. Since 

foramsulfuron has the potential to leach 

through the soil profile knowledge of 

the persistence of it in soil as well as the 

identification of transformation products

under anaerobic soil conditions will help 

the Agency determine and estimate 

exposure of foramsulfuron and other 

residues of potential toxicological 

concern to non-target organisms. The 

results of this study will be used in the 

environmental fate assessment, and later 

on, in the ecological risk 

characterization of the potential 

exposure of anaerobic transformation 

product as results of using groundwater 

for irrigation. 

835.4300 Aerobic aquatic 

metabolism 45109728 supplemental no 

Identification of unknown residues and 

non-extracted materials would be 

helpful; however, we do not expect 

identification of these residues to alter 

the risk assessment conclusions. 

835.4400 

Anaerobic 

aquatic 

metabolism 

45109729 supplemental 

no 

Identification of unknown residues and 

non-extracted materials would be 

helpful; however, we do not expect 

identification of these residues to alter 

the risk assessment conclusions. 45109730 supplemental 
21

OCSPP 

Guideline 

Data 

Requirement 

Submitted 

Studies 

(MRID) 

Study 

Classifications

Are data 

needed to 

conduct risk 

assessment?

Comments 

835.1230 

835.1240 

Adsorption/ 

desorption and 

leaching 

45109723 acceptable 

no1

Mobility data on isoxadifen-ethyl, the 

safener included in the corn 

formulations (Reg. Nos. 264-686 and 

264-685) would be useful to confirm the 

preliminary exposure analysis 

completed (see pg. 18). Additional 

analysis of the effect of the estimated 

Koc value on expected isoxadifen-ethyl 

[Koc =977 L/kg (10X less than the EPI 

estimate); Peak EEC 1.9 μg/L] 

concentrations suggest that exposure at 

levels of toxicological concern are not 

like to occur even if the estimated Koc 

value was an order of magnitude over 

estimated by EPI suite. The GENEEC 

results are provided in APPENDIX E. 

45109725 acceptable 

45109724 acceptable 

45109726 acceptable 

45109721 supplemental 

835.1410 Volatility – 

laboratory No data no 

Foramsulfuron is not expected to be 

volatile based on the reported vapor 

pressure. 

835.6100 

Terrestrial field 

dissipation 45109722 supplemental no No acceptable environmental chemistry 

method for foramsulfuron in soil is 

currently available. 

The MRIDs 45109722 and 45109420 

report the LOQ for foramsulfuron as 2 

ppb while MRID 45109421 reports a 

LOQ of 0.05 ppb. Due to the high 

sensitivity of plants to foramsulfuron it 

is important that the detection limits for 

foramsulfuron in soil capture the level 

of concern for the most sensitive species 

including listed plants. There is also no 

record of an ILV for foramsulfuron in 

soil. An ILV should accompany the 

environmental chemistry method. 

Analytical 

method in soil 

45109420 incomplete 

yes 45109421 incomplete

835.6200 

Aquatic field 

dissipation No data no 

Analytical 

method in water 

45109422 incomplete

yes 

No acceptable environmental chemistry 

method for foramsulfuron in water is 

currently available. 

The MRIDs 45109422 and 45109423 

report the LOQ for foramsulfuron as 0.1 

ppb. Due to the high sensitivity of 

plants to foramsulfuron it is important 

that the detection limits for 

foramsulfuron in water capture the level 

of concern for the most sensitive species 

including listed plants. There is also no 

record of an ILV for foramsulfuron in 

water. An ILV should accompany the 

environmental chemistry method.

45109423 incomplete

165-4 

(850.1730) Fish 

bioconcentration No data no 

Foramsulfuron is not expected to 

bioaccumulate based on the calculated 

Kow. 

1. Additional data would reduce uncertainty. See comments. 
22

Effects 

Table 15 and Table 16 identify the ecological effects studies, as well as study classifications and whether or not 

further data are needed in order to support risk assessment. Rationale for the additional data requested is 

presented below the tables. 

Table 15. Submitted Aquatic Ecological Effects Data for Foramsulfuron 

OCSPP 

Guideline 

Data 

Requirement 

Submitted 

Studies 

(MRID) 

Study 

Classifications 

Are data 

needed to 

conduct 

risk 

assessment? 

Comments 

 850.1010 Freshwater 

invertebrate 

acute toxicity 

 45109906 Supplemental No -- 

 

 

850.1025 

850.1035 

850.1045 

850.1055 

Saltwater 

invertebrate 

acute toxicity 

45109929 Acceptable No -- 

45109928 Supplemental 

 

 850.1075 Freshwater fish 

acute toxicity 

45109903 Acceptable No -- 

45109904 Supplemental 

 

 850.1075 Saltwater fish 

acute toxicity 

45109927 Acceptable No -- 

 

 850.1300 Freshwater 

invertebrate 

life cycle 

45109907 Acceptable No -- 

 850.1350 Saltwater 

invertebrates 

life cycle 

 No Due to the lack of any indication of toxicity of 

foramsulfuron to fish or invertebrates, the 

value of these additional data to the ecological 

risk assessment is likely low. 

 850.1400 Freshwater fish 

early-life stage 

46241301 Acceptable No 

 850.1400 Saltwater fish 

early-life stage 

 No -- 

 850.1500 Fish life cycle No -- 

850.4400 Aquatic plant 

growth: 

Tier II vascular 

plants 

45109913 

45109911 

45109912 

Supplemental 

Acceptable 

Acceptable 

Yes A Tier II Aquatic Plant Growth study on 

Lemna is needed for a typical end use product 

for turf uses. Available Lemna toxicity data 

suggest that aquatic vascular plants are highly 

sensitive to foramsulfuron; however, only 

TGAI and formulations for corn have been 

tested (these contain a herbicide safener that 

may influence the final toxicity estimation). 

850.5400 Aquatic Plant 

Growth: 

Tier II algae 

45109909 Acceptable No -- 

45109910 Acceptable 

45109930 Acceptable 

45109908 Acceptable 

 
23

Table 16. Submitted Terrestrial Ecological Effects Data for Foramsulfuron

OCSPP 

Guideline 

Data 

Requirement 

Submitted 

Studies 

(MRID) 

Study 

Classifications 

Are data 

needed for 

risk 

assessment? 

Comments 

 850.2100 Avian oral 

toxicity 

45109733 Acceptable No Low toxicity to other avian species and low 

use rates suggest that risk to passerine species 

is unlikely to exceed levels of concern. 45109734 Acceptable 

 850.2200 Avian dietary 

toxicity 

45109735 Acceptable No -- 

45109736 Acceptable 

 850.2300 Avian 

reproduction 

45109901 Supplemental No -- 

45109902 Supplemental 

Nonguideline Avian inhalation No -- 

 850.3020 Honey bee acute 

contact toxicity 

45109915 Acceptable No -- 

 Honey bee acute 

oral toxicity 

45109914 Acceptable No -- 

850.3030 Honey bee 

residue on foliage 

 No -- 

 850.3040 Field testing for 

pollinators 

 No -- 

850.4100 Terrestrial plant 

toxicity: 

Tier II seedling 

emergence 

45483802 Acceptable Yes A Tier II Seedling Emergence study is needed 

for a typical end use product for turf uses. 

Available toxicity data suggest that terrestrial 

plants are highly sensitive to foramsulfuron, 

however only TGAI, and end-use 

formulations for corn that contain a safener 

have been tested (the safener may 

underestimate the final toxicity estimation). 

850.4150 Terrestrial plant 

toxicity: 

Tier II vegetative 

vigor 

45483801 

45109931 

Acceptable 

Acceptable 

Yes A Tier II Vegetative Vigor study is needed for 

a typical end use product for turf uses. 

Available toxicity data suggest that terrestrial 

plants are highly sensitive to foramsulfuron, 

however only TGAI, and end-use 

formulations for corn that contain a safener 

have been tested (the safener may 

underestimate the final toxicity estimation). 

124-1 Terrestrial Plant 

Field Testing 

 Yes The November 26, 2002 Notice of 

Registration for EPA Reg. No. 264-686 

identified this study as a requirement. To 

date, it has not been submitted to the EPA. 

124-2 Aquatic Plant 

Field Testing 

 Yes The November 26, 2002 Notice of 

Registration for EPA Reg. No. 264-686 

identified this study as a requirement. To 

date, it has not been submitted to the EPA. 

Additional effects information that would be useful to the Agency include: 

1. ecological incidents (non-target plant damage and avian, fish, reptilian, amphibian and mammalian 

mortalities) not already reported to the Agency 
24

2. major degradate toxicity data 

3. information regarding effects of foramsulfuron on plant reproduction (e.g., fruit numbers, seed numbers, 

volume and weight of seed, number of flowers) 

4. label clarifications including maximum number of applications per year, maximum application rate per 

year, and the minimum application treatment interval 

 
25

APPENDIX A 

Kinetic Analysis Images 

MRID 45109714 combined label lowa silty clay loam 

MRID 45109714 combined label north carolina loamy sand 
26

MRID 45109713 combined label shuttleworth sandy loam 

MRID 45109713 combined label orainville clay loam 

 
27

MRID 45109713 combined label chantepie clay loam 

 
28

APPENDIX B 

 SIP ANALYSIS 

 

Table 1. Inputs 

Parameter Value 

Chemical name Foramsulfuron 

Solubility (in water at 25oC; mg/L) 94600 

 

Mammalian LD50 (mg/kg-bw) 5000 

Mammalian test species laboratory rat 

Body weight (g) of "other" mammalian species 

 

Mammalian NOAEL (mg/kg-bw) 15000 

Mammalian test species laboratory rat 

Body weight (g) of "other" mammalian species 

 

Avian LD50 (mg/kg-bw) 2000 

Avian test species northern bobwhite quail 

Body weight (g) of "other" avian species 

Mineau scaling factor 1.15 

 

Mallard NOAEC (mg/kg-diet) 4438 

Bobwhite quail NOAEC (mg/kg-diet) 1000 

NOAEC (mg/kg-diet) for other bird species 

Body weight (g) of other avian species 

NOAEC (mg/kg-diet) for 2nd other bird species 

Body weight (g) of 2nd other avian species 

 

Table 2. Mammalian Results 

Parameter Acute Chronic 

Upper bound exposure (mg/kg-bw) 16271.2000 16271.2000 

Adjusted toxicity value (mg/kg-bw) 3845.8028 11537.4085 

Ratio of exposure to toxicity 4.2309 1.4103 

Conclusion* 

Exposure through drinking 

water alone is a potential 

concern for mammals 

Exposure through drinking 

water alone is a potential 

concern for mammals 

 

Table 3. Avian Results 

Parameter Acute Chronic 

Upper bound exposure (mg/kg-bw) 76626.0000 76626.0000 

Adjusted toxicity value (mg/kg-bw) 1440.8590 106.2983 

Ratio of exposure to acute toxicity 53.1808 720.8580 

Conclusion* 

Exposure through drinking 

water alone is a potential 

concern for birds 

Exposure through drinking 

water alone is a potential 

concern for birds 

 

*Conclusion is for drinking water exposure alone. This does not combine all routes of exposure. Therefore, when 

aggregated with other routes (i.e., diet, inhalation, dermal), pesticide exposure through drinking water may 

contribute to a total exposure that has potential for effects to non-target animals. 
29

APPENDIX C 

STIR Analysis Results 

Welcome to the EFED 

Screening Tool for Inhalation Risk 

This tool is designed to provide the risk assessor with a rapid method for determining the potential 

significance of the inhalation exposure route to birds and mammals in a risk assessment. 

 

Input 

Application and Chemical Information 

Enter Chemical Name t 

Enter Chemical Use t 

Is the Application a Spray? (enter y or n) y 

If Spray What Type (enter ground or air) air 

Enter Chemical Molecular Weight (g/mole) 452.3 

Enter Chemical Vapor Pressure (mmHg) 7.5E-05 

Enter Application Rate (lb a.i./acre) 0.076 

 

Toxicity Properties 

Bird 

Enter Lowest Bird Oral LD50 (mg/kg bw) 2000 

Enter Mineau Scaling Factor 1.15 

Enter Tested Bird Weight (kg) 0.178 

Mammal 

Enter Lowest Rat Oral LD50 (mg/kg bw) 5000 

Enter Lowest Rat Inhalation LC50 (mg/L) 5.04 

Duration of Rat Inhalation Study (hrs) 4 

Enter Rat Weight (kg) 0.35 

 

Output 

Results Avian (0.020 kg ) 

Maximum Vapor Concentration in Air at Saturation (mg/m3) 1.83E+00 

Maximum 1-hour Vapor Inhalation Dose (mg/kg) 2.30E-01 

Adjusted Inhalation LD50 1.12E+01 

Ratio of Vapor Dose to Adjusted Inhalation LD50 2.04E-02 Exposure not Likely Significant 

Maximum Post-treatment Spray Inhalation Dose (mg/kg) 7.30E-03 

Ratio of Droplet Inhalation Dose to Adjusted Inhalation LD50 6.50E-04 Exposure not Likely Significant 

 

Results Mammalian (0.015 kg ) 

Maximum Vapor Concentration in Air at Saturation (mg/m3) 1.83E+00 

Maximum 1-hour Vapor Inhalation Dose (mg/kg) 2.89E-01 

Adjusted Inhalation LD50 3.00E+02 

Ratio of Vapor Dose to Adjusted Inhalation LD50 9.63E-04 Exposure not Likely Significant 

Maximum Post-treatment Spray Inhalation Dose (mg/kg) 9.18E-03 

Ratio of Droplet Inhalation Dose to Adjusted Inhalation LD50 3.06E-05 Exposure not Likely Significant 
30

APPENDIX D 

ECOSAR Results for the Safeners Isoxadifen-ethyl and Mefenpyr-diethyl 

Isoxadifen-ethyl 

ECOSAR Version 1.10 Results Page 

 SMILES : C2(C(=O)(OCC))=NOC(C2)(c3ccccc3)c1ccccc1 

CHEM : 

CAS Num: 

ChemID1: 

MOL FOR: C18 H17 N1 O3 

MOL WT : 295.34 

Log Kow: 5.660 (EPISuite Kowwin v1.68 Estimate) 

Log Kow: (User Entered) 

Log Kow: (PhysProp DB exp value - for comparison only) 

Melt Pt: (User Entered for Wat Sol estimate) 

Melt Pt: (deg C, PhysProp DB exp value for Wat Sol estimate) 

Wat Sol: 0.1917 (mg/L, EPISuite WSKowwin v1.43 Estimate) 

Wat Sol: (User Entered) 

Wat Sol: (PhysProp DB exp value) 

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

Values used to Generate ECOSAR Profile 

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

Log Kow: 5.660 (EPISuite Kowwin v1.68 Estimate) 

Wat Sol: 0.1917 (mg/L, EPISuite WSKowwin v1.43 Estimate) 

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

Available Measured Data from ECOSAR Training Set 

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

 Measured 

CAS No Organism Duration End Pt mg/L (ppm) Ecosar Class Reference 

=========== ========== ========== ====== ========== =========================== 

========================= 

163520-33-0 Daphnid 48-hr LC50 NES Aliphatic Amines OPP Pesticide Ecotoxicity DB 

ECOSAR v1.1 Class-specific Estimations 

Aliphatic Amines 

 Predicted 

ECOSAR Class Organism Duration End Pt mg/L (ppm) 

=========================== ================== ======== ====== ========== 

Aliphatic Amines : Fish 96-hr LC50 0.223 * 

Aliphatic Amines : Daphnid 48-hr LC50 0.041 

Aliphatic Amines : Green Algae 96-hr EC50 0.014 

Aliphatic Amines : Fish ChV 0.004 

Aliphatic Amines : Daphnid ChV 0.005 

Aliphatic Amines : Green Algae ChV 0.007 

=========================== ================== ======== ====== ========== 

Neutral Organic SAR : Fish 96-hr LC50 0.125 

(Baseline Toxicity) : Daphnid 48-hr LC50 0.133 

 : Green Algae 96-hr EC50 0.126 

 : Fish ChV 0.018 

 : Daphnid ChV 0.025 

 : Green Algae ChV 0.167 

 Note: * = asterisk designates: Chemical may not be soluble enough to 

 measure this predicted effect. If the effect level exceeds the 

 water solubility by 10X, typically no effects at saturation (NES) 

 are reported. 

 
31

APPENDIX E 

GENEEC Results for the Safeners Isoxadifen-ethyl and Mefenpyr-diethyl 

Isoxadifen-ethyl 

RUN No. 2 FOR isoxadifen-ethyl ON any * INPUT VALUES * 

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

 RATE (#/AC) No.APPS & SOIL SOLUBIL APPL TYPE NO-SPRAY INCORP 

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

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

 .038( .076) 2 3 9777.0 1.3 GRHIFI( 6.6) .0 .0 

 FIELD AND STANDARD POND HALFLIFE VALUES (DAYS) 

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 METABOLIC DAYS UNTIL HYDROLYSIS PHOTOLYSIS METABOLIC COMBINED 

 (FIELD) RAIN/RUNOFF (POND) (POND-EFF) (POND) (POND) 

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

 .00 2 N/A .00- .00 .00 .00 

 GENERIC EECs (IN NANOGRAMS/LITER (PPTr)) Version 2.0 Aug 1, 2001 

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

 PEAK MAX 4 DAY MAX 21 DAY MAX 60 DAY MAX 90 DAY 

 GEEC AVG GEEC AVG GEEC AVG GEEC AVG GEEC 

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

 525.66 510.66 427.69 299.21 237.89 

RUN No. 4 FOR isoxadifen-ethyl ON any * INPUT VALUES * 

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 RATE (#/AC) No.APPS & SOIL SOLUBIL APPL TYPE NO-SPRAY INCORP 

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

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

 .038( .076) 2 3 977.0 1.3 GRHIFI( 6.6) .0 .0 

 FIELD AND STANDARD POND HALFLIFE VALUES (DAYS) 

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

 METABOLIC DAYS UNTIL HYDROLYSIS PHOTOLYSIS METABOLIC COMBINED 

 (FIELD) RAIN/RUNOFF (POND) (POND-EFF) (POND) (POND) 

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

 .00 2 N/A .00- .00 .00 .00 

 GENERIC EECs (IN MICROGRAMS/LITER (PPB)) Version 2.0 Aug 1, 2001 

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

 PEAK MAX 4 DAY MAX 21 DAY MAX 60 DAY MAX 90 DAY 

 GEEC AVG GEEC AVG GEEC AVG GEEC AVG GEEC 

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

 1.88 1.87 1.83 1.74 1.67