### 2 (DCI) to address uncertaintie s surrounding the environmental fate and potential ecological
effects of sulfometuron methyl

.

### 3 

# Problem Formulation for the Environmental Fate, Ecological Risk, Endangered Species, and Human Health Drinking Water Exposure Assessments in Support of the Registration Review of Sulfometuron Methyl

SULFOMETURON METHYL PC Code: 122001; CAS Number: 74222

- 97

- 2
SMILES: n1c(C)cc(C)nc1NC(=O)NS(=O)(=O)c2ccccc2C(=O)OC

Chemical Name:
2

- [[[[(4,6

- Dimethyl

- 2

- pyrimidinyl) amino] carbonyl] amino] sulfonyl] benzoic acid, methyl ester

Prepared by: 

### Robin Sternberg , Ecologist , ERB I
Michael Barrett

, Senior Chemist , ERB V U.S. Environmental Protection Agency Office of Pesticide Programs
Environmental Fate and Effects Division
Environmental Risk Branch V 1200 Pennsylvania Ave., NW
Mail Code 7507P Washington, DC 20460 Reviewed by: 

### Keith Sappington, Biologist, ERB V
José L

. Meléndez, Chemist , ERB V Approved by: 

### Mah Shamim, PhD, Branch Chief , ERB V 

## Date: Dece mber 5
, 2012

### 4 TABLE OF CONTENTS

1. INTRODUCTION

................................ ................................ ................................ ................................ .................. 5

2. PREVIOUS CONCLUSI ONS

................................ ................................ ................................ ................................ ... 7

E COLOGICAL R ISK A SSESSMENTS

................................ ................................ ................................ ................................ ....... 7

D RINKING W ATER E XPOSURE A SSESSMENTS

................................ ................................ ................................ ....................... 8

C LEAN W ATER A CT P ROGRAMS

................................ ................................ ................................ ................................ ........ 9

3. FATE SUMMARY

................................ ................................ ................................ ................................ ................. 9

3.1. C HEMISTRY AND E NVIRONMENTAL F ATE OF P ARENT

................................ ................................ .............................. 9

3.2. T RANSFORMATION P RODUCTS

................................ ................................ ................................ ......................... 19

4. RECEPTORS

................................ ................................ ................................ ................................ ................. 21

4.1. E FFECTS OF P ARENT S ULFOMETURON M ETHYL TO A QUATIC AND T ERRESTRIAL O RGANISMS

................................ ......... 21

4.2. E FFECTS OF DEGRADATES TO AQUATIC AND TERRE STRIAL ORGANISMS

................................ ................................ ...... 23

4.2.1. Overview

................................ ................................ ................................ ................................ .................. 23 4.2.2. Analysis of Available Toxicity Data

................................ ................................ ................................ ........... 24

4.3. E COLOGICAL I NCIDENTS

................................ ................................ ................................ ................................ .. 29

5. EXPOSURE PATHWAYS OF CONCERN

................................ ................................ ................................ .......... 32

6. ANALYSIS PLAN

................................ ................................ ................................ ................................ ............... 32

6.1. S TRESSORS OF C ONCERN

................................ ................................ ................................ ................................ . 32

6.2. M EASURES OF E XPOSURE

................................ ................................ ................................ ............................... 33

6.3. M EASURES OF E FFECT

................................ ................................ ................................ ................................ .... 33

6.4. E NDANGERED S PECIES A SSESSMENTS

................................ ................................ ................................ ................ 34

6.5. E NDOCRINE D ISRUPTOR S CREENING P ROGRAM

................................ ................................ ................................ ... 34

7. PRELIMINARY IDEN TIFICATION OF DATA G APS

................................ ................................ ............................... 34

Environmental Fate Data Requirements

................................ ................................ ................................ ............ 35 Ecological Effects Data Requirements

................................ ................................ ................................ ................ 37

APPENDIX 1. SUBMITT ED ENVIRONMENTAL FAT E AND EFFECTS STUDIE S

................................ .......................... 42

ENVIRONMENTAL FATE S TUDIES

................................ ................................ ................................ ......................... 42

SUBMIT TED EFFECTS STUDIES:

................................ ................................ ................................ ................................ 50

APPENDIX 2: STRUCTUR ES AND CHEMICAL NAME S OF SULFOMETURON ME THYL METABOLITES

....................... 55

APPENDIX 3. UNCERTA INTIES RELATED TO TH E USE OF INCIDENT IN FORMATION FROM THE E COLOGICAL

INCIDENT INFORMATION SYSTEM

................................ ................................ ................................ ....................... 57

APPENDIX 4. SIP V.1 .0 INPUTS AND OUTPUT S

................................ ................................ ................................ .... 59

APPENDIX 5. STIR V. 1.0 INPUTS AND OUTPU TS

................................ ................................ ................................ .. 61

APPENDIX 6. THE RIS K QUOTIENT METHOD AN D LEVELS OF CONCERN

................................ .............................. 62

APPENDIX 7. TOXICIT Y ENDPOINTS FOR SULF OMETURON METHYL AND ITS DEGRADATES AND A NALOGUES

.... 64

Degradate toxicity in comparison to parent toxicity

................................ ................................ .......................... 66

### 5 

# 1. Introduction

The purpose of this problem formulation is to provide an understanding of the environmental fate and ecological effects of the registered uses of sulfometu ron methyl ( 2

- [[[[(4,6

- Dimethyl

- 2

- pyrimidinyl) amino] carbonyl] amino] sulfonyl] benzo ic acid, methyl ester )

. Sulfometuron

methyl is a sulfonyl urea herbicide; this class of pesticides has been targeted by the Agency for
the evaluation of common degradate s and with respect to their m ode s of action and toxicological profiles which will be ad dressed in this document

. Similar to other sulfonylurea herbicides, the
mode of action of parent sulfometuron methyl involves inhibiting the activity of the enzyme acetolactate synthase (ALS), which in turn inhibits the synthesis of selected amino acids th at are required for cell proliferation in plants. ALS is also known as acetohydroxyacid synthase ( AHAS) (HRAC Group B) 1



### . This particular mode of action appears to impart herbicidal activity and require relatively low concentrations of the chemical to produce such effects, as evidenced by the generally low range of labeled rates.

In sulfometuron methyl the sulfonylurea moiety serves as a “bridge” between an amino

pyri mi dine (the “ Q ” moiety on the

- NH

- or amine side of bridge) and an ester i fied ben zoic acid (“ A ” on the

- SO 2 

### - or sulfonyl side of bridge) ring structures in the molecule as shown below in Figure 1

.

Generic Molecular Structure for Sulfonylurea Herbicides

1 URL: http://www.hracglobal.com/ (accessed 08/02/2012) Stidham, Mark A. 1 991. Herbicides That Inhibit Acetohydroxyacid Synthase. Weed Science 39(3):428

- 434.

### 6 Sulfometur on Methyl Chemical Structure Figure 1 . Molecular structure of a sulfonylurea and sulfometuron methyl

.

Many sulfonylurea herbicides share similar A and Q moieties, these will be discussed further in the Toxicity discussion below.

Sulfometuron

- methyl is labeled for use on rangeland, uncu ltivated agriculture areas, and swamps/marshes/bogs after water has receded, seasonally dry flood areas 2



### , rights of way, forest trees, ornamental lawns and turf, ornamental woody shrubs and vines, ornamental and/or shade trees, drainage systems, drained ca nals, uncultivated nonagricultural areas, loading docks (outdoor), and storage areas (outdoor). The uses of sulfometuron methyl are further summarized in the “BEAD Chemical Profile for Registration Review: Sulfometuron

- methyl (122001) dated
5/30/2012. Recent label changes in response to the Reregistration Eligibility Document have been approved by the Agency ( memorandum entitled “Clarifications to Sulfometuron Methyl
Label Table Dated October 2011” from OPP Pesticide Re

- Evaluation Division to Registrati on Division ). Currently labels are adopting measures from the Reregistration Eligibility Decision (RED) to mitigate identified risks. Major changes on the new labels will be that all uses will be limited to a maximum single rate of 0.199 lb ai / A for for estry uses and 0.281 lb ai / A for other (non

- agricultural) uses, aerial applications of liquid formulations will be limited to rotary aircraft, and numerical buffers will be required for applications made near sensitive sites. For the
current Problem Form ulation, the Agency has assessed the subject sulfometuron methyl labels as they are currently registered. The Agency acknowledges that risks are expected to be reduced

once mitigation has been fully implemented , and anticipates that the preliminary risk assessment for sulfometuron methyl will reflect label changes required via the RED

Sulfometuron

- methyl is formulated as a water dispersible granular and soluble concentrate ; and is applied using ground or aerial application methods . On current labels both the maximum single and annual application rate s are up to 0.375 lb a

. i

. / acre or less depending on the use site

2 The labels prohibit applications to natural or man

- made bodies of water such as lakes, reservoirs, ponds, streams,
and canals.

### 7 (the range of application rates allowed by site is summarized in detail in the revised risk assessment for the RED, DP Barcode D354292, 7/ 14/2008; only rangeland uses have been added since then)

.

This document will provide a plan for analyzing data relevant to environmental and human
health risk for sulfometuron

- methyl

. Additionally, this problem formulation is intended to identify data gap s, uncertainties, and potential assumptions used to address those uncertainties,
relative to a sulfometuron methyl ecological risk assessment

.

EFED will use application scenarios that result in maximum exposure for a given use for the risk

assessment. Any absence of information on the labels that specifies the maximum single application rate, the application interval, the annual maximum rate allowed (lbs a.i./year), or application method will result in conservative assumptions as illustrated in the foll owing examples:

• A maximum single application rate is specified with a re

- application interval of 7 days without specifying a maximum annual rate may result in an assumption of 52 applications with 7

- day intervals;

• A label that does not preclude aerial appl ications will likely result in an assumption of aerial pesticide applications;



# 2. Previous Conclusions

Recent EFED reviews for sulfometuron methyl include:

• DP Barcode D354292; 7/14/2008: R eregistration eligibility EFED chapter, revised.

• DP Barcode: D355888; 2/2/2009: New use for rangeland restoration.

• DP Barcode D334277; 2/8/2009; Drinking water assessment.

• DP Barcode D346187and D346188 ; 4/2008 : Review of sulfometuron

- methyl spray drift study.

• DP Barcode D346169; 11/2009: Response to RED comments an d refined spray drift analysis by EFED.

Risk assessment conclusions from these assessments are summarized below.



## Ecological Risk Assessments

In previous ecological risk assessments concerns were identified for direct effects on terrestrial and aquatic pl ants from sulfometuron methyl uses. Although direct effects on birds, mammals, fish, and aquatic invertebrates were not identified some uncertainties remain and these are
discussed below

.

Important exposure pathways include leaching to groundwater, spray drift, and runoff to surface water. Although the residues of concern are believed to be for parent only, it is important to note the exposure level to degradates can be equal or higher than to parent (an analysis of the potential for risk from exposure to degradates is also included in this document)

.

### 8 At the maximum registered application rate for sulfometuron methyl (0.375 lb a

. i

. /A), LOCs for direct effects on aquatic and terrestrial anim als are not exceeded. Lack of risk from direct effects on animals is consistent with the mode of action of sulfometuron methyl and findings from other
sulfo nylurea risk assessments.

Potential risks to aquatic and terrestrial plants have been identified with LOCs exceeded for terrestrial and aquatic plants at all application rates. This is the case because sulfometuron methyl is by design a herbicide with especially high activity on so me sensitive plant species and it cannot be assumed that any exposed plant is less sensitive in the absence of specific toxicity data for the species in question. The impact of spray drift practices recommended by the label did not reduce RQ values below L OCs for terrestrial plants (RQs were reduced only by a factor of three compared to ‘high end’ exposure assumptions). Potential risks to terrestrial plants from irrigation with sulfometuron methyl contaminated surface water were also evident (RQ = 3.9 and

7 1 for non

- endangered and endangered species, respectively) 3



### . Risks to plants from groundwater exposure were evaluated and determined to not exceed LOCs. Although LOCs were not exceeded for terrestrial or aquatic animals, animals that depend on plants for survival or reproduction (presumably all taxa at the screening level) are also at risk from indirect effects resulting from potential direct effects to aquatic or terrestrial plants.

Use of ‘typical’ application rates as reported by the registrants woul d result in RQs significantly
lower than annual application of the max imum application rate (for example, because applications apparently are only rarely applied more than once or twice every several years, not annually as the current labels allow)

, howeve r, the typical rates may still result in RQs above Agency LOCs for terrestrial and aquatic plants. The conclusion of potential risks to aquatic and terrestrial plants from sulfometuron methyl application in non

- crop uses is consistent with findings from o ther sulfonylurea herbicide risk assessments and ecological incident reports associated with sulfometuron methyl use.

Direct effects LOCs were exceeded for endangered aquatic and terrestrial plants. In addition, there is potential for indirect effects to all animal taxa that depend on plants for survival, growth, or reproduction, which are presumably all animal taxa at the screening level. Therefore, listed species from all taxonomic groups are potentially at risk from sulfometuron methyl uses.



## Drinki **ng Water Exposure Assessments**

A drinking water exposure assessment for the proposed new use on rhubarb was conducted for
sulfometuron

- methyl as part of the Reregistration Eligibility Decision in 200 8 (USEPA, DP Barcode D334277; 2/ 14 / 200 8 ; EFED ecological risk assessment chapter {revised} for reregistration eligibility ). For surface water, the acute screening value was 31.98 ppb and the
chronic was 14.51 ppb . The groundwater screening concentration wa s 0.3 3 ppb . These values
represent upper

- bound estimates of the concentrations that might be found in surface water (a

v ulnerable reservoir) and ground water for drinking water due to the use of sulfometuron methyl

3 Endangered / listed species assessments require a more conservative LOC assumption resulting in higher estimated RQs for the same level of exposure.

### 9 at the maximum allowable rate within the watershed. Exposure estimates were also generat ed for the total residues of sulfometuron methyl which include sulfometuron

- methyl and major degradates such as a pyrimidine amine, a sulfonamide degradate, and saccharin (see Appendix 1 for structures and chemical names of degradates)

. For surface water s ulfometuron methyl total residue exposure the acute value wa s 32.35 ppb and the chronic wa s 21.82 ppb . The

groun dwater screening concentration wa s 1. 13 ppb

. Overall, this screening level analysis showed that even if all degradates of sulfometuron methyl a re included in a drinking water assessment acute exposure is not significantly increased and chronic exposure is increased by about 50% compared to the estimated exposure to parent sulfometuron methyl alone.



## Clean Water Act Programs

Sulfometuron methyl 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 sulfometuron methyl. Aquatic benchmarks have been
established for sulfometuron methyl and are summarized in Table 1 . Details are available at http://www.epa.gov/oppefed1/ecorisk_ders/aquatic_life_benchmark.htm . Any data submitted or otherwise located as part of the Registration Review process may be used to update aquatic life benchmarks if applicable.

Table 1

. OPP freshwater A quatic Life Benchmarks (μg / L)

.

Organism

- ---- -  Fish Invertebrates No n vas

c ular

Plants Vascular

Plants

Exposure Duration

--  Acute Chronic Acute Chronic Acute Acute

Pesticide:

Sulfometuron methyl > 74,000 — > 75,000 97,000 4.6 0.48



# 3. Fate Summary

**3.1. Chemistry and Environmental Fate of Parent** 

The physicochemical properties ( Table 2 ) and the body of environmental fate data submitted ( Table 3 ) demonstrates sulfometuron methyl is mobile (all measured Koc values < 100 and persistent (degradation half

- lives from a few weeks to several months in various laboratory and field studies) in the environment. Sulfometuron methyl is more soluble in neutral and alkaline water than in acidic water. The major route of dissipation for sulfometuron methyl is aerobic and

### 10 anaerobic degradation / metabolism in soil and water (pseudo first

- order degradation half

- lives 4 

### generally around 2 to 6 months), with hydrolysis potentially dominant under acidic conditions. However, sulfometuron methyl degradation rate and mobility in the environment can be characterized as highly variable

– significantly affected by soil and water properties such as pH

an d organic matter and with often significantly increased resist a nce to degradation in soil over
time.

As summarized in Table 3 and previously in the Ecological Fate and Effects chapter to the
sulfometuron

- methyl RED (DP Barcode D354292 ) the sulfometuron methyl environmental fate data show some unusual characteristics of sulfometuron methyl in that some field dissipation
rates at some sites are slower t han the degradation rates measured in aerobic soil metabolism
studies. Furthermore, both measured laboratory degradation and field dissipation rates are in some cases slower than the hydrolysis rate measured in the laboratory (particularly under acidic

co nditions) for sulfometuron methyl. These data indicate that the fate of sulfometuron methyl may be highly site dependent

– an important factor to consider in risk assessments

.

Table 2 . Nature and product chemistry of the chemical s tressor

- Sulfometuron methyl.

Common name Sulfometuron methyl

IUPAC Chemical Name 2

- (4,6

- Dimethylpyrimidin

- 2

- ylcarbamoylsulfamoyl) benzoic acid, methyl

ester

or 2

- [3

- (4,6

- dimethylpyrimidin

- 2

- yl)ureidosulfonyl] benzoic acid, methyl ester

CAS Chemical Name 2

- [[[[(4,6

- Dimethyl

- 2

- pyrimidinyl) amino] carbonyl] amino] sulfonyl] benzoic acid, methyl ester

Structure

Pesticide type Herbicide

Chemical class Sulfonylurea herbicide

CAS number 74222

- 97

- 2 Empirical formula C 15 H 16 N 4 SO 5 Molecular Mass (g/mol) 364.38 Vapor pressure at 20 o C 5.4 x10 - 16 Torr Henry’s Law Constant at 20 o C (atm m3/mol) 1.1 x 10 - 18 , calculated from vapor pressure Solubility in water (mg/L) at 20 0 C pH 5 buffer...... 6.42 ppm pH 7 buffer ...... 244 ppm pH 8.6 buffer.. 12,500 ppm Log K
ow pH 5 = 1.03 pH 7 =

- 0.46 pH 9 =

- 1.87 pKa at 25°C 5.2

4 All first

- order rates / degradation half

- lives discussed in this document, were, unless otherwised specified, calculated from linear regression of log

- transformed decay data.

### 11 Table 3

. K ey results of sulfome turon methyl environmental fate studies.

Parameter
Guideline # [ Old Guideline #] Value 1 MRID(s)

Hydrolysis

835.2120 [161

- 1] t 1⁄2 = 8.8 days @ 25 o C, pH 5;

t 1⁄2 =139 days @ 25 o C, pH 7;

t 1⁄2 = 224 days @ 25 o C, pH 9.

Major degradates (from cleavage of the sulfonylurea bridge):
Sulfonamide

– only in acidic water
Saccharin

– all pH levels Pyrimidine amine

– all pH levels 42715201

Direct photolysis
in water
835.2240 [161

- 2] Combined labels results:

t 1⁄2 = 428 days @ 24 o C, pH 5;

t 1⁄2 = stable @ 24 o C, pH 7;

t 1⁄2 = stable @ 24 o C, pH 9. (calculated by the difference in degradation rates between irradiated and dark controls and adjusting for typical light levels on sunny days)

Major degradates (irradiated water): pH 5: sulfonamide, pyrimidine amine; pH 7: none; pH 9: none. 42182401
43174101 (suppleme ntal)
Previous study
#41672812
is supplement
al.

Photolysis on soil
835.2410 [161

- 3] t 1⁄2 = 72.1 days @ 25 o C 5

, Study duration was 33 days, substantial degradation occurred in dark controls and the calculated photolysis half

- life represents the difference in the dissipation rate in the irradiated and the dark control samples.

Major degradates (from clea vage of the sulfonylurea bridge): Saccharin reached a maximum of 48.4% of the applied at 33 days (study termination.) Pyrimidine amine reached a maximum of 53.1% at 33 days (study termination.) There was no substantial difference in the degradation pathway of sulfometuron methyl between the irradiated

- and the dark control soil.

No other degradate accounted for >4% of the applied radioactivity regardless of whether the phenyl ring or the pyrimidine ring was 14 C

- labeled. 41420601

5 Hydrolysis may have been a significant factor in the dark controls. The reported pH of the test soil (Keyport silt loam) was 6.8, but the soil series tends to be more acidic which would likely promote signifincant abiotic hydrolysis.

### 12 Table 3

. K ey results of sulfome turon methyl environmental fate studies.

Parameter
Guideline # [ Old Guideline #] Value 1 MRID(s)

Aerobic soil
metabolism
835.4100 [162

- 1] Study with [pyrimidine

- 2

- 14 C] Sulfometuron Methyl Soil: Keyport Silt loam (pH 6.3, 1.6% O.C.) from Delaware (0. 68 mg a.i./kg

First Order t 1⁄2 : 57.8 days (r 2 = 0.9239).
Observed DT50: 23 days.
Observed DT90: 110 days.
Sterile soil First Order t 1⁄2 : 364 days

Major transformation products: Pyrimidine amine (maximum 41.0% of the applied at 30 days, Final: 11.4% at 365 days ) Pyrimidine

- ol (maximum 10.5% of the applied at 63 days, 4.6% at 365 days ).
CO 2 (maximum 53.1% of ap plied). Minor transformation products: Free acid sulfometuron methyl (up to 4.1%)

. Pyrimidine urea (up to 2.4%)

. 42091401

Aerobic soil
metabolism
835.4100 [162

- 1] Study with U

- 14 C

- phenyl

- labeled Sulfometuron Methyl Soil: Keyport Silt loam (pH 6.4, 1.6 % O.C.) from Delaware (0.12 mg a.i./kg) results (an exaggerated rate of 1.0 mg ai/kg was also tested)

. First Order t 1⁄2 : 5 1.1 days ( linear; r 2 = 0.9 664 ).
Observed DT50: 29 days.
Observed DT90: 162 days. (values are calculated from results with 2 applica tion rates: 0.12 and 1.0 mg a.i. / kg with the higher rate study added to facilitate more precise characterization of degradation pathways.

Major transformation products : Sulfonamide (maximum 17% of applie d at 0 days, Final: <1% at 168 days. Saccharin (maximum 30% of applied at 14 days, 3 % at 168 days ) At the high rate sulfonamide was up to 11% at 14 days and <1% at 168 days and saccharin was up to 37% at 28 days and 14% at 168 days.

Minor (possibly major) products : Free acid sulfonamide (Max imum of % at 168 days); at the exaggerated rate it was 22% at 72 days and declined to 2% at 168 days). 43174102
and
245375

### 13 Table 3

. K ey results of sulfome turon methyl environmental fate studies.

Parameter
Guideline # [ Old Guideline #] Value 1 MRID(s)

Anaerobic aquatic
metabolism
835.4200 [162

- 3] 1. Study performed with [pyrimidine

- 2

- 14 C] Sulfometuron Methyl

Matrix: Bradenton Pond water

- sand sediment.
First Order t 1⁄2 : 37.4 days (r 2 = 0.6125). Observed total system DT50: 22 to 61 days (inconsistent decline data). Observed total system DT90: 102 days. Major transformation products (both systems):
free acid sulfometuron methyl (Up to 5 3.9 % at 28 days; Final: 3.6 % at 364 days)

. pyrimidine amine (Up to 52.7 % at 1 68 days; Final: 27.0 % at 364 days)

. Minor identified transformation products: pyrimidine

- ol.
CO 2
.

Matrix: Landenberg Pond water

- sandy loa m sediment.
First Order t 1⁄2 ; total system: 17.1 days (r 2 = 0. 0.6394). Observed total system DT50: 6.1 days. Observed total system DT90: 21.7 days. Major transformation products (both systems): free acid sulfometuron methyl (Up to 55.9% at 28 days; Final: 0 .8% at 364 days)

. pyrimidine amine (Up to 71.4% at 112 days; Final: 56.2% at 364 days)

. Minor identified transformation products: pyrimidine

- ol.
CO 2
. 42091402
and
43188601

### 14 Table 3

. K ey results of sulfome turon methyl environmental fate studies.

Parameter
Guideline # [ Old Guideline #] Value 1 MRID(s)

Anaerobic aquatic
metabolism
835.4400 [162

- 3] 2. Study with [phenyl

- U

14 C] Sulfometuron Methyl

Matrix: Pond water

- sandy loam sediment from Bradenton, Florida. (water pH 5.5 . Sediment: pH 5.1; O.C. = 5.9 %).
First Order t 1⁄2 ; total system: 104 days (r 2 = 0.4883)*. Observed DT50 in total system: ca. 21 days.
Sterile t 1⁄2 ; total syst em: 44 days

* Residues were highly variable over time data.

Matrix: Pond water

- silt loam sediment from Landenberg, Pennsylvania. (water pH 5.8 . Sediment: pH 5.6; O.C. = 2.1 %).
First Order t 1⁄2 ; total system: 87 days (r 2 = 0.3577).
Observed DT50 in total system: ca. 28 days.
Sterile t 1⁄2 ; total system: 175 days

Matrix: Pond water

- loam sediment from Saskatoon, Canada. (water pH 8.3 . Sediment: pH 7.8; O.C. = 0.9 %).
First Order t 1⁄2 ; total system: 77 days (r 2 = 0.5853). Observed DT50 in total system: ca. 70 days.
Sterile t 1⁄2 ; total system: 399 days

Matrix: Pond water

- silt loam sediment from Walnut Grove, Tennessee. (water pH 5.5 . Sediment: pH 5.1; O.C. = 0.5 %).

First Order t 1⁄2 ; total system: 73 days (r 2 = 0.5691). Observed DT50 in total system: ca. 28 day s. Sterile t 1⁄2 ; total system: 95 days

Major transformation products:
saccharin.
free acid sulfonamide. Minor identified transformation products: Methyl

- 2

- aminocarbonyl(aminosulfonyl)benzoate. 4413010

- 20 (143540)

### 15 Table 3

. K ey results of sulfome turon methyl environmental fate studies.

Parameter
Guideline # [ Old Guideline #] Value 1 MRID(s)

Aerobic aquatic
metabolism
835.4300 [162

- 4] Study performed with [pyrimidine

- 2

- 14 C] Sulfometuron Methyl

Matrix used: Pond water

- silt loam sediment (Landenberg, acidic system )
First Order t 1⁄2 ; total system: 9.2 days (r 2 = 0.94). Observed DT50 in total system: 15 days.
Observed DT90 in total system: 31 days (extrapolated).

Major transformation products: Pyrimidine amine (pyrimidine label). Hydroxymethyl

- pyrimidine sulfometuron methyl. Free acid sulfonamide (phenyl label). Sulfonamide (phenyl label). Minor identified transformation products:
C O 2
.

Matrix used: Pond water

- sand sediment (Bradenton, alkaline system).
First Order t 1⁄2 ; total system: 187.3 days (r 2 = 0.5713). Observed DT50 in total system: > >39 day s (study termination)

.

Major transformation products: Pyrimidine amine (pyrimidine label). Free acid sulfonamide (phenyl label). Minor identified transformation products: Hydroxymethyl

- pyrimidine sulfometuron methyl. Sulfonamide (phenyl label).
CO 2
. 42091403
and
43174103

### 16 Table 3

. K ey results of sulfome turon methyl environmental fate studies.

Parameter
Guideline # [ Old Guideline #] Value 1 MRID(s)

Adsorption/ Desorption (K d and

K
oc in L K 1 g - 1 )
835.1230 [163

- 1] Parent sulfometuron methyl : Soil type: Chino Sandy loam; pH 7.1, organic carbon 1.0%. Adsorption K d : 0.35. Adsorption K

oc : 35. Freundlich adsorption K F : 0.153. Freundlich adsorption K Foc : 14.7.
1/N 0.504

Soil type: Fargo silt loam ; pH 7.7, organic carbon 2.6%. Adsorption K d : 2.07. Adsorption K

oc : 79.6. Freundlich adsorption K F : 2.12. Freundlich adsorption K Foc : 83.2.
1/N 1.23

Soil type: Miaka Sand ; pH 7.0, organic carbon 0.6%. Adsorption K d : Negative.

K
oc : Negative. Freundlich adsorption K F : 0.508. Freundlich adsorption K Foc : 87.6.
1/N 1.61

Soil type: Tama Silt loam ; pH 6.7, organic carbon 1.5%. Adsorption K d : 0.79. Adsorption K

oc : 52.7. Freundlich adsorption K F : 0.974. Freundlich adsorption K Foc : 67.2.
1/N 0.851 42789301

### 17 Table 3

. K ey results of sulfome turon methyl environmental fate studies.

Parameter
Guideline # [ Old Guideline #] Value 1 MRID(s)

Adsorption/ Desorption Of Degradates Sulfometuron Pyrimidine amine

This study is in review.

For rimsulfuron, a structurally similar pyrimidine amine degradate (but with

4

- , 6

- dimethoxy rather than 4

- , 6

- dimethyl substitution of the pyr i midine amine) was reported to have K d values of 0.23 to 1.52 and K

oc values of 19 to 61 in four test soils. See DP Barcode D326660, EFED review of rimsulfuron methyl new uses dated 3/14/07 for more details.

Saccharin

This study is in review.

Saccharin has been reported elsewhere to be quite mobile, e.g. : When tested as a degradate of metsulfuron methyl ( http://ec.europa.eu/food/plant/protection/evaluation/existactive/list1

- 13_en.pdf )

Sulfometuron Sulfonamide

This study is in review. 42789301

### 18 Table 3

. K ey results of sulfome turon methyl environmental fate studies.

Parameter
Guideline # [ Old Guideline #] Value 1 MRID(s)

Terrestrial Field/Lysimet er Dissipation 2

835. 6100 Greenville, MS silty clay loam soil: pH 6.7, 0.6% O.C.
Half

- life: 49.2 days (based on 0

- to 359

- day data); 12.2 days (based on 0

- to 91

- day data).
DT90: 32 days Major transformation products detected (>0.01 ppm):
S ulfometuron free acid (SFA) Pyrim i dine amine (PYA)
Sulfonamide IN

- D5803 (SFN)
Saccharin IN

- 581 (SCC)

Rochelle, IL silty clay loam soil: pH 6.8, 1.0% O.C.
Half

- life: 128 days (based on 0

- to 723

- day data, residues in 0

- 15 cm depth only); 14.4 days (based on 0

- to 90

- day data).
DT90: 35 days Major transformation products detected (>0.01 ppm): PYA, SFN, and SCC

Uvale, TX clay soil: pH 7.9, 1.3% O.C.
Half

- life: 53.3 days (based on 0

- to 447

- day data); 13.0 days (based on 0

- to 90

- day data).
DT90: 25 days Major transformation products detected (>0.01 ppm): PYA, SFN, and SCC

Maldera, CA sandy loam soil: pH 7.8, 0.7% O.C.
Half

- life: 44.1 days (based on 0

- to 420

- day data); 22.9 days (based on 0

- to 180

- day data).
DT90: 55 days Major transformation product s detected (>0.01 ppm): PYA, SFN, and SCC 43212101
and
43637101

Forestry Dissipation
835.6300 Gainesville, FL sand soil: pH 4.0, 0.62% O.M. (study in review)

Scooba, Mississippi silty clay loam soil: pH 4.5, 4.0% O.M. (study in review) 42091404
and
43174104

1 Unless otherwise specified, half

- lives were derived with a “Log

- linear” degradation rate calculation; a process of calculating degradation rates and half

- lives from linear regression of log

- transformed concentration
measurements over time. This provides a first

- order type of measurement of pesticide decline.

2 For these field dissipation studies, differences between half

- lives measured over various time durations apparently reflect both slowing of degradation at lower temperatures and a large v ariability in measured concentrations; also, a 2

- compartment degradation model for adsorbed and dissolved sulfometuron is quite possibly more appropriate (little dissipation of the remaining residues in the top soil occurred during the second year of these studies, for example). A 2

- compartment model was not used to represent dissipation rate here
because the data are not sufficient ly robust ( e.g. , very high variability between replicate measurements), the effects of weather changes on degradation rate cann ot easily be isolated, and the amount of residues lost through dissipation out of the topsoil also cannot be separated from the amount lost to degradation. At all four of these field study sites about 99% of the applied sulfometuron methyl dissipated from the top soil within 3 to 6 months.

### 19 Sulfometuron

- methyl persistence in water indicates that if, either via spray drift or any runoff event, sulfometuron methyl reaches surface water, it may persist for a few weeks to several months and present some concern to surface water resources. The toxicity of sulfometuron methyl to certain plant species at very low levels ( i.e. , at only a small fraction of the already low application rates) means that there is a risk for exposure at toxic levels at far distances from the application site via spray drift (discussed in greater detail in previous reviews). The fairly low use rate (maximum annual rate of 0.375 lb ai/A) and the apparent typical use pattern of applying
in on ly one or two years out of a several year period should limit the actual exposure of sulfometuron methyl parent residues in surface water

. H owever, note that sulfometuron methyl could negatively affect certain sensitive plants at very low exposure levels b ecause it is such a potent herbicide with respect to many plant species

.

The log K OW 

### values for sulfometuron methyl are ≤ 1.03 and therefore, bioconcentration of the
chemical in aquatic animal tissue is not expected.



## 3.2. **Transformation Products**

Like most other registered sulfonylurea herbicides, cleavage of the sulfonylurea bridge between two ring structures occurs early in the degradation of the molecule creating two separate degradation pathways with fractions of the parent molecule; in the case of sulfometuron methyl

, these are an esterified benzoic acid and a pyrimidine amine mo iet y

. The rate at which the sulfonylurea bridge is cleaved is similar under anaerobic and aerobic conditions. Complete degradation / mineralization is more rapid under aerobic conditions. The h ydrolytic cleavage of the sulfonylurea bridge generates a sulfonamide plus the aminopyrimidine (resulting in elimination of a carbon dioxide molecule) ; similar metabolites may be the products of other sulfonylurea herbicides (discussed in further detail below)

. The sulfonamide is further cyclized with the carbomethoxy group in the ortho position, yielding saccharin

. Degradation by this same pathway occurs at a slower rate under sterile conditions.

The most common ly formed and persistent environmental degradates are the sulfometuron sulfonamide, the sulfometuron pyrimidine amine, and saccharin; other degradates occur less commonly (see A PPENDIX 2 : Structures and Chemical Names of Sulfometuron methyl
Metabolites ). D eesterification from sulfometuron methyl to the free acid occurs , but this degradate does not appear to accumulate substantially

.

### The sulfometuron methyl pyrimidine amine and benzoic acid methyl ester moieties are shared in similar or identical in a number of other sulfonylurea herbicides (all of these herbicides by definition share the sulfonylurea bridge) as list ed below 6 

### :

“Q” Moiety Pyrimidine amine (dimethyl) : Sulfometuron methyl Pyrimidine amine (Other substituted

– usually methoxy

- or dimethoxy

- ) : Amidosulfuron
Azimsulfuron
Bensulfuron
Chlorimuron
Flazasulfuron
Foramasulfuron Halosulfuron methyl
Imazosulfuron
Mesosulfuron
Nicosulfuron
Orthosulfamuron
Primisulfuron methyl Pyrazosulfuron
Rimsulfuron
Sulfosulfuron

“A” Moiety:
Benzoic acid ester : Bensulfuron methyl Chlorimuron ethyl Ethametsulfuron methyl Metsulfuron methyl Primisulfuron methyl Sulfometuron methyl Tribenuron methyl Benzoic ester with other ring substitution : Idosulfuron Triflusulfuron methyl

The only submitted studies directly evaluating the fate of sulfometuron methyl degradates were adsorption / desorption studies on the pyrimidine amine and saccharin. The soil retention characteristics
of t hree of the sulfometuron methyl degradates were studied in batch equilibrium adsorption / desorption
studies

, these studies are in review and these results have not yet been validate d; therefore the following values can only be considered suggestive of what the sorption characteristics of these compounds might
be : saccharin K f 

### s were 0.03 to 0.27 and the pyrimidine amine K f 

### s were 0.17 to 3.70 in the four test soils ( Table 3 ). This means saccharin might be slightly more mobile and the pyrimidine amine slightly less mobile than parent (K f 

### s of 0.15 to 2.12 in the same four soils)

.

6 Not all of the listed herbicides have registered uses in the United States. The “Q” and “A” moieties are defined in Section 1

.

### 21 

# 4. Receptors

**4.1. Effects**  **of Parent Sulfometuron Methyl to Aquatic**  **and Terrestrial Organisms** 

A summary of toxicity data for sulfometuron methyl from registrant

- submitted studies is provided in
Table 4

. As expected, the acute toxicity of sulfometuron methyl to aquatic and terrestrial animals is very low (slightly to practically non

- toxic) whereas its toxicity to plants is very high. This finding is
consis tent with the mode of action of sulfometuron methyl ( i.e. , inhibition of ALS) and is similar to toxicity findings from other sulfonylurea herbicides. The following data are not available for sulfometuron methyl:

• c hronic reproductive toxicity data for fish

, birds, and mammals

,

• chronic toxicity data for estuarine/marine invertebrates and fish, and

• acute toxicity data for a passerine species.

In previous risk assessments the Levels of Concern (LOCs) for sulfometuron on sensitive terrestrial plant species have been shown to be exceed ed by wide margins when exposure is calculated from sulfometuron methyl use at maximum label rates (e.g., DP Barcode D355888 and D354292) with spray drift a major route of exposure. LOCs are also exceeded for aquatic plants, but by much smaller margins than terrestrial plants.

LOCs are not exceeded for any terrestrial or aquatic animal taxa evaluated. Sulfometuron methyl is practically non

- toxic to birds, mammals

, and bees on an acute toxicity basis ( Table 4 )

. No sublethal effects were observed from the acute toxicity studies of birds and mammals. Data on reproductive effects of sulfometuron methyl to birds were not available. Acceptable d ata on mammalian reproductive effects were also not available. Data on the effects of gestational exposure to sulfometuron methyl were available from a rabbit developmental toxicity study which resulted in a NOAEL of 300 mg ai/ kg

- bw/d (highest dose tested ). Sulfometuron methyl is practically non

- toxic or at most slightly toxic for aquatic animal taxa ( Table 4 ). This compares with expected peak exposure levels of 0.032 mg/L or less in surface waters even when sulfometuron methyl is applied at maximum label rates throughout the watershed ( Table 5 ).

Table 4

. Summary of the Endpoints from Aquatic and Terrestrial Toxicity Studies for Sulfometuron Methyl

Taxonomic Group Study Type Species Toxicity Value Acute Toxicity
Classification Source

Freshwater
f ish Acute Rainbow t rout ( Oncorhynchus mykiss ) 96

- hr LC 50 > 148 mg a.i./L
96

- hr NOEC = 148 mg a.i./L (no mortality) Practically

non

- toxic MRID 43501802* Acceptable

Bluegill sunfish ( Lepomis
macrochirus ) 96

- hr LC 50 > 150 mg a.i./L
96

- hr NOEC = 150 mg a.i./L (no mortality) Practically

non

- toxic MRID 43501801 Acceptable

Chronic No data

### 22 Taxonomic Group Study Type Species Toxicity Value Acute Toxicity
Classification Source

Freshwater
invertebrates Acute Water flea ( Daphnia

magna ) 96

- hr EC 50 > 150 mg a.i./L
96

- hr NOEC = 150 mg a.i./L Practically

non

- toxic MRID 43501803 Acceptable

Chronic Water flea ( Daphnia

magna ) 21

- day NOEC = 97 mg a.i./L N/A MRID 41672806* Acceptable

Saltwater
fish Acute Sheepshead
minnow ( Cyprinodon variegatus ) 96

- hr LC 50 > 45 mg a.i./L
96

- hr NOEC = 45 mg a.i

. /L At most

s lightly toxic 1 MRID 41672803 Supplemental**

Chronic No data

Saltwater
invertebrates Acute Eastern oyster ( Crassostrea virginica ) 48

- hr IC 50 > 38.2 mg a.i../L
48

- hr NOEC = 38.2 mg a.i./L At most

s lightly toxic 1 MRID 41672805 Supplemental**

Mysid shrimp ( Mysidopsis
bahia ) 96

- hr LC 50 > 44.8 mg a.i./L
96

- hr NOEC = 44.8 mg a.i./L (no mortality) At most

s lightly toxic 1 MRID 41672804 Supplemental**

Chronic No data

Aquatic plants Vascular Duckweed ( Lemna gibba G3) 14

- day EC 50 = 0.4 5 μg a.i./L

14

- day NOEC = 0.207 μg a.i./L N/A MRID 43538503* Acceptable

Non

vascular Green alga ( Selenastrum capricornutum ) 5

- day EC 50 = 4. 3 μg a.i./L
5

- day NOEC = 0.63 μg a.i./L (based on cell density) N/A MRID 41680102 * Acceptable

Blue

- green alga ( Anabaena flos

aqua ) 5

- day EC 50 = 73 μg a.i./L
5

- day NOEC = 14 μg a.i./L (based on cell density) N/A MRID 43538502 * Acceptable

Freshwater
diatom ( Navicula pelliculosa ) 5

- day EC 50 > 370 μg a.i./L
5

- day NOEC = 370 μg a.i./L (based on cell density) N/A MRID 43538502 * Acceptable

Marine diatom ( Skeletonema

costatum ) 5

- day EC 50 > 410 μg a.i./L
5

- day NOEC = 410 μg a.i./L (based on cell density) N/A MRID 43538502 * Acceptable

Birds Acute Mallard duck ( Anas platyrhynchos ) 14

- day LD 50 > 4650 mg a.i./kg

- bw (no mortality) Practically

non

- toxic MRID 00078700 Acceptable

Passerine No data

Sub

- acute dietary Mallard duck ( Anas platyrhynchos ) 8

- day LD 50 > 4600 mg a.i./kg

- diet (no mortality) At most

s lightly toxic 1 MRID 00071414 Acceptable

Northern bobwhite quail ( Colinus virginianus ) 8

- day LD 50 > 5620 mg a.i. /kg

- bw (no mortality) Practically

non

- toxic MRID 00088813 Acceptable

Chronic No data

Mammals Acute Rat 14

- day LD 50 > 5000 mg a.i./kg

- bw Practically

non

- toxic MRID 43089201

Terato

genicity 2 Rabbit NOAEC = 300 mg a.i./kg

bw/d N/A MRID 00078798

### 23 Taxonomic Group Study Type Species Toxicity Value Acute Toxicity
Classification Source

Terrestrial
invertebrates Acute

contact Honeybee ( Apis mellifera ) 48

- hr LD 50 > 100 μg a.i./bee
48

- hr NOEC = 100 a.i. μg/bee Practically

non

- toxic MRID 41672810 Acceptable

Terrestrial plants Seedling

emergence Most sensitive monocot

N/A MRID 43538501* Acceptable Sorghum EC 25 = 1.9x10 - 4 lb a.i./A
EC 05 = 4.3x10 - 5 lb a.i./A + (based on shoot height)

Most sensitive dicot Sugar beet EC 25 = 3.1x10 - 5 lb a.i./A
NOEC = 2.9x10 - 5 lb a.i./A (based on shoot dry weight)

Vegetative vigor Most sensitive monocot

N/A MRID 43538501* Acceptable Corn EC 25 = 3.7x10 - 5 lb a.i./A
EC 05 = 8.4x10 - 6 lb a.i./A + (based on shoot dry weight)

Most sensitive dicot Soybean EC 25 = 1.8x10 - 5 lb a.i./A
EC 05 = 1.0x10 - 6 lb a.i./A + (based on shoot dry weight) N/A = not applicable

1 Toxicity endpoint was greater than the highest concentration tested, which fell in the slightly toxic category.

2 A combined 2

- generation reproduction/ oncogenicity study and 2

- year chronic reproduction study with rats exposed to sulfometuron methyl was submitted to the agency (MRID 42385705 and 42385706). However, study authors had to abandon the study on about day 200 due to disease of the test organisms that was n ot related to exposure, and the study was classified as unacceptable by HED. A developmental toxicity study with rat (MRID 00078796) was also classified as unacceptable by

HED.
* Toxicity values were revised after a re

- review and analysis of the study resu lts in 2007 (MRIDs 41672806, 43501802, and 43538501) and 2012 (MRIDs 41680102, 435385032, and 43538503). ** Supplemental classification due to high variability in measured test concentrations and uncertainty in exposure to dissolved sulfometuron methyl ( i. e. , test samples were not centrifuged prior to analysis).

+ EC 05 is reported for estimating effects to listed (endangered) terrestrial plants because the NOAEC equaled or exceeded the
EC 25
.



### Table 5

. Summary of Estimated Environmen tal Concentrations (EECs) for Aquatic Exposure to Parent Sulfometuron Methyl as Modeled for the 2008 Ecological Risk Assessment for the Reregistration of Sulfometuron Methyl (USEPA, 2008)

Method of Application Peak EEC ( m g/L) 21

- day EEC ( m g/L) 60

- day EEC ( m g/L)
Ground 0.0046

- 0.0261 0.0004

- 0.0216 0.0003

- 0.0155

Aerial 0.0012

- 0.0315 0.0011

- 0.0262 0.0010

- 0.0205

1 BOLD indicates largest EEC ; values are estimated 1 in10 year return frequency concentrations after long

- term application
at maximum labeled rates throughout the watershed.



## 4. **2**

**. Effects of degradates to aquatic and terrestrial organisms** 

4.2.1 . Overview

Five degradates were identified as major products in at least one environmental fate study: saccharin

, pyrimidine amine, pyrimidine

- ol, sulfonamide, and free acid sulfonamide (full chemical names and

### 24 structures of each are given in Appendix 2). The major degradates of sulfometuron methyl form by bridge cleavage producing fractional degradates having a toxicological p rofile that may be very different from the parent molecule and

, given the low application rates of sulfometuron methyl, the degradates need to be fairly potent toxins to a particular class of organisms to trigger a risk concern.

F rom the substantial diff erence in structure from the parent molecule it appears unlikely that the identified major degradates would significantly contribute to toxicity to sensitive plants on or near the application site . However, no direct data have been submitted to support thi s hypothesis. We also explored the potential for ecological effects from these degradates and have concluded that t he preponderance of the available evidence indicates that ecological effects from sulfometuron use likely primarily arise from the toxicity o f sulfometuron per se to sensitive terrestrial or aquatic plant and alga l species (including indirect effects on organisms that may be impacted by these direct effects on plants and algae)

.

For this Problem Formulation we analyzed structure

- activity relat ionships using the Ecological Structure Activity Relationships (ECOSAR) version 1.00 model and additionally performed some comparisons with toxicity data from related degradates of other Note that ECOSAR, only estimates effect levels for aquatic species (and does not include aquatic macrophyte estimates)

. In terms of effects on terrestrial species we not e that

, while no direct data are available for degradate effects on terrestrial organisms

, exposure to degradates on or near application areas will be lo wer than to parent because of dissipation processes as well as because the mass of each of the degradate molecules is much lower than the mass of the parent sulfometuron methyl molecule.



## 4.2.2 . Analysis of Available Toxicity Data

Direct toxicity testing is only available for the saccharin degradate. In the absence of toxicity
data for the effects of the other degradates on the growth, reproduction, development, and
survival of aquatic animals and plants, predicted acute and chronic toxicity values for pyrimidine amine, pyrimidine

- ol, sulfonamide, and free acid sulfonamide were generated us ing ECOSAR
which is based on quantitative structure activity relationships (QSAR) for effects on fish, daphnids, and green algae (effects on aquat ic and terrestrial plants are not estimated) . Predicted chronic toxicity values were also generated for saccharin since no chronic toxicity data were
submitted for saccharin.

ECOSAR

- predicted toxicity (and, when available, measured toxicity) values were compared to predicted estimated environmental concentrations ( EECs ) to determine whether additional degradate
toxici ty data could add value to the R egistration R eview ecological risk assessment (these comparisons
are summarized in . Since EECs cannot be r eliably modeled individually for the degradates due to the lack of appropriate data on the environmental fate of these compounds, predicted EECs for the degradates were conservatively assumed to be similar to those of the parent compound sulfometuron methy l 7 

### . EECs for sulfometuron methyl were taken from the 2008 ecological risk assessment for the reregistration of sulfometuron methyl (USEPA, 2008 )

.

7 The amount of each degradate formed is expected to be less than the amount of parent applied because of incomplete conversion (the degradates also form in smaller masses because the molecular weights of major degradates formed by

### 25 An overall summary of the measured and estimated levels for toxic effects of parent and degradates is presented in Table 6

.

splitting of the parent m olecule are substantially less than parent). Mobility of degradates is expected to be equivalent to or less than parent based up on available data. Degradate persistence could be somewhat higher than parent, but this is not expected to be enough to result in higher EECs.

### Table 6

. Summary of Available Measured and ECOSAR

- Predicted Toxicity Endpoints for Sulfometuron methyl, its Major Degradates, and Analogues.

PREDICTED OR MEASURED EFFECT LEVELS

PARENT SULFOMETURON DEGRADATES 8 ANALOG (to sulfom. Pyrimidine amine) 

### Organism Expected Exposure
Level 

### Parent (measured) 

### Parent (model) 

### PyrAm (model) 

### PyrOl (model) 

### SfnAm (model) 

### SfnAc (model 

### Sacch (meas.) 

### Sacch (model) 

### Dimethoxy PyrAm (measured) 9 

### Dimethoxy PyrAm (modeled)
mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L



### Fish

Acute ( 96

- hr
LC 50 ) 0.0315 >148.0 72

– 79.00 61.00 60.00 151 to
268 10 11669.0 124.00

--- 97.00 11 79 to 920

Chronic (~30

- day) 0.0205 ND 0.47

– 6.90 0.29 3.60 1.60 to
18.00 69.00 2.40

--- ND 0.38 to
90.00



### Algae

Acute (~ 96

- hr
LC 50 ) 0.0315 0.0046 0.04 101.0 79.0 1.10 17.0 >10.00 12

--- 120.0 0.92 to 130

Chronic (# days?) 0.0262 ND 0.01 30.00 38.0 0.36 3.40 ND 3.4 ND ND

8 PyrAm = Pyrimidine Amine PyrOl = Pyrimidine

- ol SfnAm = Sulfonamide

SfnAc = Sulfonamide acid Sacch = Saccharin
9 Other company chemical codes for this metabolite include INJV0290, AE

- F092944, and HOE092944. All measured aquatic toxi city data for this compound were retrieved from PPDB through a search for the string “2

- amino

- 4,6

- dimethoxypyrimidine” or for “AE

- F092944” (duplicate entries for this compound in the database may not contain this information). The Pesticide Properties Data base (aka. Footprint) may be accessed at: http://sitem.herts.ac.uk/aeru/footprint/en/index.htm

2 ChV = ECOSA R chronic toxicity value

10 Acute and chronic endpoint estimation ranges listed are based upon ester SAR classification for both fresh and saltwater fish species and amide classification
for freshwater fish.
11 The species tested was Rainbow trout ( Oncorhynchus mykiss )

. 12 Species tested: Green alga ( Selenastrum capricornutum ); MRID 48518910; in review . Reported value is 72

- hr. LC 50
.

### 27 PREDICTED OR MEASURED EFFECT LEVELS

PARENT SULFOMETURON DEGRADATES 8 ANALOG (to sulfom. Pyrimidine amine) 

### Organism Expected Exposure
Level 

### Parent (measured) 

### Parent (model) 

### PyrAm (model) 

### PyrOl (model) 

### SfnAm (model) 

### SfnAc (model 

### Sacch (meas.) 

### Sacch (model) 

### Dimethoxy PyrAm (measured) 9 

### Dimethoxy PyrAm (modeled)



### Daphnid

Acute (~ 48

- hr
LC 50 ) 0.0315 >150.0 40

– 154.0 700.0 16.0 98 to
364 3192* >118

---- >100 2.4 to 469

Chronic ~(21

- day) 0.0262 97.0 0.53

- 105.0 + 27 3.1 1.3 to
316 42 + 13 ND 1.70 24.0 0.05

– 36.0



### Mysid shrimp

Acute (~ 96

- hr
LC 50 ) 0.0315 >44.8 121 ND ND 419.0 ND ND ND ND ND

Chronic (# day ns) 0.0262 ND 16516 * ND ND 430000 14 ND ND ND ND ND



### Aquatic macrophyte (Lemna gibba)

Acute (7

- or 14

- day EC 50 ) 0.0262 ND ND ND 62.0 ND ND 5.5 ND >100.0 ND



### Saltwater fish

Acute ( 96

- hr
LC 50 ) 0.0315 >45.0 111.0 ND 67.0 256.0 ND ND ND ND ND

Chronic (# day ns) 0.0262 ND 15 + ND ND 30 + ND ND ND ND ND

13 

### + = The toxicity value was determined from a predicted SAR using established ACR ratios and ECOSAR regression techniques.

14 * = P redicted toxicity value may exceed compound’s aqueous solubility

.

## Saccharin Degradate

The saccharin degradate of sulfometuron methyl has numerous other anthropogenic origins in the environment including from its commercial use as an artificial sweetener and as a degradate of certain other pesticides (including several sulfonylurea herbicides) and pharmaceuticals. A literature
review was not conducted for this Problem Formulation but we note here that, given its widespread
use as a food additive and its other sourc es it is likely the published literature may provide additional information on the toxicity of saccharin.

Although some of this data is in review, a preliminary examination of the data indicates that saccharin is practically non

- toxic to freshwater fish a nd invertebrates and mammals on an acute basis with toxicity endpoints comparable to those of parent sulfometuron methyl. However, saccharin is 4 to 5 orders of magnitude less acutely toxic to aquatic plants than sulfometuron methyl.

Acute aquatic toxi city values (5.5 to >124 mg/L) for saccharin are at least 2 order s of magnitude greater than the largest predicted peak EEC for sulfometuron methyl (0.0315 mg/L, and chronic aquatic toxicity values (1.7 to 3.4 mg/L) are at least two orders of magnitude gre ater than the largest predicted 21

- and 60 day EECs (0.0205 to 0.0262 mg/L; Table 10 ). Thus there is little concern for risk to these organisms from exposure to saccharin.



## Other Degradates ( pyrimidine amine, pyrimidine

- ol, sulfonamide, and free acid
sulfonamide )

No direct studies are available regarding the toxicity of the other four major or potentially major degradates so we used ECOSAR to predict levels at which toxic effects might occur and have compared these levels to the highest EECs for aquatic exposure to parent in Table 11 (as a conservative surrogate for the potential exposure to degradates )

. 15 

### All of the predicted toxic endpoints are multiple orders of magnitude lower than the highest parent sulfometuron methyl EECs

exce pt for the following:

• Pyrimidine amine predicted fish chronic toxicity value is as low as 0.29 mg/ L compared to a possible exposure level of 0.02 mg / L

• Sulfonamide predicted green algae chronic toxicity value is as low as 0.36 mg/ L compared to a possibl e exposure level of 0.02 mg / L

Even the above two predicted toxicity values are more than 10x less than the highest predicted parent EECs.

In addition to the measured values for degradates in Table 6 , measured and estimated toxicity values for a structurally related degradate to the sulfometuron methyl dimethyl pyrmidineamine are presented in the same table and

– this analysis also shows effects levels on plants and animals for this analog to occur only at levels of exposure much greater than expected to arise from the application of sulfometuron methyl. Additional details on this analysis are provided in Appendix 7.

15 A rare exception to this would be where a degradate persists for multiple years in a water body with no outlet or turnover of water potentially resulting in long

- term accumulation of residues in the water body.

### 29 

## 4. **3**

**. Ecological Incid**  **ents**

A preliminary review on July 25, 2012, of the Ecological Incident Information System (EIIS, version 2.1), which is maintained by the Agency’s Office of Pesticide Programs, and the Avian Monitoring Information System (AIMS), which is maintained by the American Bird Conservancy, indicates a
total of 34 reported ecological incidents associated with the use of sulfometuron methyl. These
incidents are sum marized in Table 7 . This total excludes incidents classified as ‘unlikely’ or ‘unrelated’ and only includes those incidents with certainty categories of ‘possible’, ‘probable’, and ‘highly probable’ (for EIIS) and ‘possible’, ‘probable’, ‘likely’, ‘highl y likely’ and ‘certain’ (for AIMS). Incidents classified as ‘unlikely’ the result of or ‘unrelated’ to sulfometuron methyl will not be included in this Problem Formulation or the ecological risk assessment conducted for Registration
Review.

All of the su lfometuron methyl incidents, excluding those classified as ‘unlikely’ or ‘unrelated’,
occurred between 1985 and 2009. One o f the sulfometuron methyl incidents involved aquatic animals, 2 i nvolved terrestrial animals, and 33 i nvolved plants. The certainty categories regarding the likelihood that the use of sulfometuron methyl caused the 34 incidents ranged from ‘highly probable’ (1 incident) to ‘possible’ ( 13 incidents); a majority of the incidents (20) were categorized as ‘probable.’ Twenty

- two of the incidents were considered registered uses at the time of the incident, 6 involved misuses, and the legality of use was undetermined for 6 incidents. None of the incidents involved additional chemicals besides sulfometuron methyl. Sulfometuron methyl residues were not reported in any of the incident reports. All of the reported incidents for sulfometuron methyl involved 12 uses that are currently registered (agricultural area, apiary, forest, industrial site, municipal operation, peach, right

- of

- way, seedling, residential turf, utility plant, wheat, yard), and

one in which the use site was not specified. The reported incidents associated with the 12 currently registered uses had certainty categories of ‘highly probable’, ‘probable’, and ‘possible’.

I n the risk assessment, the incidents will be further evaluated to determine if the reported incidents represent current patterns of use for sulfometuron methyl. Examples of additional considerations are mitigation ( e.g ., reduced application rates), produc t cancellations, and changes in use patterns that have occurred since the date of the reported incident(s).

In addition to the incidents recorded in EIIS and AIMS, additional incidents have been reported to the Agency in aggregated incident reports. Pes ticide registrants report certain types of incidents to the Agency as aggregate counts of incidents occurring per product per quarter. Ecological incidents reported in aggregate reports include those categorized as ‘minor fish and wildlife’ (W

- B), ‘minor

p lant’ (P

- B), and ‘other non

- target’ (ONT) incidents. ‘Other non

- target’ incidents include reports of adverse effects to insects and other terrestrial invertebrates. For sulfometuron methyl, registrants
have reported 5 minor fish and wildlife incidents, 25 minor plant incidents, and 0 other non

- target incidents. Unless additional information on these aggregated incidents becomes available, they will be assumed to be representative of registered uses of sulfometuron methyl in the risk assessment.

### Table 7

. Ecological Incidents Associated with Sulfometuron Methyl 1

Incident
Number Taxa Involved Magnitude Year State Use Legality 2 Certainty

I000903

- 001 Terrestrial plant S eeds, unknown woody plant: NR 1991 TX Agricultural area Registered use Probable

I000903

- 002 Terrestrial plant P each, pecan: NR 1994 TX Agricultural area Registered use Probable

I000903

- 003 Aquatic animal, aquatic plant, terrestrial animal, terrestrial plant D eer, forage, unknown fish, unknown plant: NR 1994 TX Agricultural Area Registered use Probable

I006010

- 002 Terrestrial plant Corn: u nknown 1997 TX Agricultural area Misuse (accidental) Probable

I007269

- 001 Terrestrial plant G rape: NR 1998 CA Agricultural area Registered use Probable

I009556

- 005 Terrestrial plant Unknown Unknown NC Agricultural area Misuse (accidental) Possible

I009556

- 043 Terrestrial plant P otato: $4.4 million in damages 1992 CO Agricultural area Registered use Probable

I020592

- 001 Terrestrial plant D ouglas fir: 80% of 80 acres 2008 WI Agricultural area Registered Use Possible

I021457

- 012 Terrestrial plant P ea: some 2006 WA Agricultural area Undetermined Unlikely

I021587

- 003 Terrestrial animal H oney bee: hives 2009 NJ Apiary Registered Use Possible

I000903

- 005 Terrestrial plant U nknown tree: NR 1991 TX Forest Misuse (accidental) Probable

I015217

- 001 Terrestrial plant P asture grass: 8,000 sq ft 2004 OH Forest Registered use Probable

I016312

- 001 Terrestrial plant P onderosa pine: 300 acres 2005 OR Forest Undetermined Possible

I005972

- 001 Terrestrial plant L ive oak: 3 1997 TX Industrial site Registered Use Probable

I016429

- 001 Terrestrial plant S weet corn: 10 acres; potato: 15 acres 2005 WA Industrial site Registered use Probable

I011666

- 001 Terrestrial plant S ugar beet: 46,800 acres; garlic: 2 acres; corn: unknown; potato: unknown; wheat: 10,700 acres; alfalfa: unknown, 800 acres 2000 ID Munic i pal operation Registered Use Highly
Probable

B000601

- 001 Terrestrial plant O nion: 10 acres 1988 CA N/R Undetermined Possible

I000071

- 001 Terrestrial plant P each: large numbers 1992 SC Peach Registered Use Possible

I016680

- 001 Terrestrial plant G rap e : 13 acres 2005 OR Right

- of

- way Undetermined Possible

I013086

- 001 Terrestrial plant S ugar beet: unknown 2002 WA Right

- of

- way, rail Registered use Probable

I013194

- 001 Terrestrial plant S ugar beet: 10 acres 2002 ND Right

- of

- way, rail Registered use Probable

I020180

- 033 Terrestrial plant B russel s sprout: 9 acres 2008 CA Right

- of

- way, railroad Undetermined Possible

B000601

- 007 Terrestrial plant S ugar beet: NR 1985 NE Right

- of

- way, road Registered use Possible

I006010

- 001 Terrestrial plant C otton: unknown 1997 LA Right

- of

- way, road Misuse (accidental) Probable

I014409

- 011 Terrestrial plant O nion: NR 1992 WA Right

- of

- way, road Registered use Possible

I015576

- 001 Terrestrial plant S ugar beet: NR 2004 OR Right

- of

- way, road Registered use Probable

I015832

- 001 Terrestrial plant P ecan: 1 2004 LA Right

- of

- way, road Registered use Probable

I016302

- 001 Terrestrial plant G rass, wheat: < 1 acre 2005 WA Right

- of

- way, road Registered use Probable

I015440

- 001 Terrestrial plant C orn, soybean: 1 acre 2003 MN Right

- of

- way, utility Misuse (accidental) Probable

I015796

- 001 Terrestrial plant C orn: 1

- 4 acres 2004 KY Right

- of

- way, utility Registered use Possible

### 31 Incident
Number Taxa Involved Magnitude Year State Use Legality 2 Certainty

I015265

- 001 Terrestrial plant P ine: unknown 2004 TX Seedling Registered use Possible

I017481

- 001 Terrestrial plant Turf: un known 2006 WI Turf, residential Undetermined Probable

I006010

- 003 Terrestrial plant, aquatic plant Grass: unknown aquatic plant:
unknown 1997 MS Utility plant Misuse (accidental) Probable

I020627

- 007 Terrestrial plant O rnamental: NR 2001 WA Wheat Undetermined Possible

I007269

- 002 Terrestrial plant G rass seed: NR 1998 TN YARD Registered use Probable NR = not reported

1 ‘Minor’ incidents aggregately reported by the registrant(s) are not included in this table.

2 Incidents classified as ‘unrelated’ and ‘unlikely’ are excluded.

# 5. Exposure Pathways of Concern

The environmental fate properties of sulfometuron methyl indicate that spray drift, leaching to ground water, atmospheric deposition, and runoff represent potential transport mechanisms of sulfometuron methyl to aquatic and terrestrial organisms. Spray drift has been noted to be a special concern for many sulfo nylurea herbicides because sensitive plants can be adversely affected by a small fraction of the applied amount. Drinking water and inhalation exposure pathways were screened using the SIP (Screening Imbibition Program, v1.0) and STIR (Screening Tool for Inhalation Risk, v1.0) screening methods. Results generated by SIP indicate that chronic exposure through drinking water alone is a potential concern for birds (see Appendix 3 ) . However, there is some uncertai nty associated with this result . Since a NO AEC is not available for birds, chronic exposure to sulfometuron methyl through drinking water was characterized using chronic toxicity data for primisulfuron and flazasulfuron, sulfonylureas with a similar toxicity profile and the same mode of action as s ulfometuron methyl

. Results generated by STIR indicate exposure via inhalation was of low concern (no LOC exceedances are expected ; see Appendix 4 ). SIP and STIR are described in detail at: http://www.epa.gov/oppefed1/models/terrestrial/index.htm

.


# 6 . Analysis Plan

In order to address the risk hypothesis, the potential for adverse effects on the environment is estimated. The use, environmental fate, and ecological effects of sulfom eturon methyl are characterized and integrated to assess the potential for risks. This is accomplished using a risk quotient (ratio of exposure concentration to effects concentration) approach (Appendix 6 ). Although risk is often defined as the likelihoo d and magnitude of adverse ecological effects, the risk quotient

- based approach does not provide a quantitative estimate of likelihood and/or magnitude of an adverse effect. However, as outlined in the Overview Document (USEPA 2004), the likelihood of eff ects to individual organisms from particular uses of sulfometuron methyl is estimated using the probit dose

- response slope and either the level of concern (discussed below) or actual calculated risk quotient values.

This analysis plan will be revisited an d may be revised depending upon the information submitted by the registrant and the public in response to the opening of the Registration Review
docket for sulfometuron methyl

.



## 6.1. **Stressors of Concern**

Ecological Risk Assessment

The stressor of concern for terrestrial and aquatic organisms is parent sulfometuron methyl.

### 33 As previously stated in the section on degradate toxicity, the major degradates of sulfometuron methyl are several orders of magnitude less toxic than the parent sulfometuron methyl to terrestrial plants, and are therefore not expected to alter the risk picture. Furthermore, none of the degradates have been identified as chemicals of concern based on the conclusions of the EPA
Health Effects Division Metabolism C ommittee Meeting (D200158, March 29, 1994). Therefore, EFED does not expect any of these degradates to be toxic to mammals or birds.

Drinking Water

A new drinking water assessment will be conducted to support future human health dietary risk

assessme nts of sulfometuron methyl and will consider all currently registered uses of sulfometuron methyl

. The new drinking water assessment will incorporate model estimates as well as available monitoring data of sulfometuron methyl and any transformation product s of toxicological concern that might be identified by the Health Effects Division in surface water and groundwater. The potential toxicity of sulfometuron methyl transformation products will be considered in the drinking water assessment conducted during the Registration Review process. The final determination of the residues of concern will be made through consultation with the Health Effects Division (HED) and through any proceedings of the ROCKS (Residues of Concern Knowledge Subcommittee).



## 6.2. **Mea sures of Exposure** 

In order to estimate risks of sulfometuron methyl 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 sulfometuron methyl are discussed on OPP’s water model website. 16 

### These models include: PRZM ( P esticide R oot Z one M odel) and EXAMS ( EX posure A nalysis M odeling S ystem),

PRZM

- groundwater (GW), T

- REX, TerrPlant, STIR (Screening Tool for Inhalation Risk) and SIP (Screening Imbibition Program) . Results of the SIP and STIR model runs are presented in Appendix 4 and 5, respectively.



## 6.3. **Measures of Effect**

Toxicity data presented in Section 3 of this problem formulation will be used to calculate risk quotients. Any additional information submitted by the registrant or found in the open literature prior to conduct of the risk assessment

, will also be consi dered. The open literature studies are identified using EPA’s ECOTOXicology database ( ECOTOX) (USEPA, 2007 c ), which employs a literature search engine for locating chemical toxicity data for aquatic life, terrestrial plants,
and wildlife. The evaluation of both sources of data can also provide insight into the direct and indirect effects of pesticides on biotic communities from loss of species that are sensitive to the chemicals and from changes in structure and functional characteristics of the affected
communities.

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

### 34 

## 6.4. **Endangered Species Assessments**

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

, threatened and/or endangered species from registered uses of pesticides in Registration Review . These assessments will be conducted in accordance with standard EPA procedures and good scientific judgment. The process for evaluating potential risks to listed species is further described at http://www.epa.gov/oppfead1/endanger/litstatus/riskasses.htm

.



## 6.5. **Endocrine Disruptor Screening Program**

Sulfometuron methyl was not included in the first group of 67 chemicals issued an order to
conduct T ier 1 EDSP testing. For additional information the EDSP program, visit http://www.epa.gov/endo/

.

EPA is required under the Federal Food, Drug, and Cosmetic Act (FFDCA), as amended by the Food Quality Protection Act (FQPA), to develop a screening program to determine whether certain substances (including all pesticide active and other ingredients) “ may have an effect in humans that is similar to an effect produced by a naturally occurring estrogen, or other such
endo crine effects as the Administrator may designate. ” Following the recommendations of its Endocrine Disruptor Screening and Testing Advisory Committee (EDSTAC), EPA determined that there was a scientific basis for including, as part of the program, the andr ogen and thyroid hormone systems, in addition to the estrogen hormone system. EPA also adopted EDSTAC’s recommendation that the Program include evaluations of potential effects in wildlife. When the appropriate screening and/or testing protocols being co nsidered under the Agency’s EDSP have been developed, sulfometuron methyl may be subjected to additional screening and/or testing to better characterize effects related to endocrine disruption.



# 7. Preliminary Identification of Data Gaps

Table 8 and Table 9 identify environmental fate and eco

- toxicological studies , respectively, that offer data for each guideline requirement, as well as study classifications and whether or not further data are needed in order to support risk assessment.

In addition to providing the guideline number and study title for required dat a, the DCI table provides a rationale for requiring the data, an explanation of how the data will be used, and a brief description of the how the data could impact the Agency’s future decision

- making

.

Before the status and needs of environmental fate and ecotoxicological studies are presented,
additional information related to sulfometuron methyl labels is needed. The maximum number of applications and minimum time interval between applications are not specified for many uses

on current sulfometuron meth yl labels. The labels should express these aspects of sulfometuron

### 35 methyl precise ly or provide a rationale as to while, in some cases these aspects of application cannot be exactly specified (but with the maximum seasonal rates still clearly specified).



## Environmental Fate Data Requirements

The Agency has completed a review of all available data submitted by the registrant as part of Registration Review. The following is required:

Guideline 835.6100 Terrestrial Field Dissipation Study

– (Supporting Envir onmental Chemistry Methods (ECMs)/Independent Laboratory Validation ( ILV): Sulfometuron methyl) : State of the art ECMs in soil and water and ILVs used in sulfometuron methyl environmental fate studies are requested at this time 17 

### . Environmental chemistry methods for soil and water are only available for parent sulfometuron methyl. In addition, no ILVs have been submitted to the Agency with the exception of the immunoassay method which does not detect sulfometuron methyl with full specificity. Therefore, ECMs should be submitted with their associated ILVs for parent sulfometuron methyl and its major degradates sulfometuron pyrimidine amine ( IN

- X0993 ), sulfometuron sulfonamide ( IN

- D5803) , and saccharin ( IN

- 581 ) in
water and soil.

Guideline 835.4100 Aerobic soil metabolism: Guideline requirements are partially fulfilled. The studies submitted to fulfill environmental fate data requirements for sulfometuron

- methyl are not complete by current standards as stipulated in 40 CFR part 158 Subpart N §158.130 0 for all pesticides with use patterns for aquatic food and nonfood applications: There are acceptable data from only one s oil for aerobic soil metabolism under guideline #835.4100. The guideline stipulates that results from at least four relevant soils of different organic carbon content, pH, clay content, and with an active microbial biomass must be submitted in order to characterize the variability in the aerobic biodegradation of the pesticide in the environment. Therefore, studies
must be conducted on three additional test soils.

The following studies have been submitted but are currently in review:
Guideline 835.1240 Adsorption / desorption (for degradates).
Guideline 835.6100 Forestry dissip ation (required because of the forestry use of
sulfometu ron )

.

Table 8 lists the status of the fate and transport data requirements for sulfomet uron methyl . The adequacy of the submitted data was evaluated relative to Age ncy guidelines.

Table 8 . Environmental Fate Data Requirements for Sulfometuron Methyl.

Guideline Data Requirement Test Material MRID Study
Classification Data Requirement
Met? More
Data
Needed?

835.2120

[161

- 1] Hydrolysis S ulfometuron methyl 42715201 Acceptable Yes No

17 The actual Field Dissipation stud ies have already been submitted and accepted.

### 36 Guideline Data Requirement Test Material MRID Study
Classification Data Requirement
Met? More
Data
Needed?

835.2240

[161

- 2] Direct photolysis
in water S ulfometuron methyl 42182401
43174101
41672812 Acceptable Acceptable Supplemental

18 Yes No

835.2410

[161

- 3] Photolysis on soil S ulfometuron methyl 41420601 Acceptable Yes No

None [161

- 4] Photodegradation
in Air NA NA Waived 19 NA NA

835.4100

[162

- 1] Aerobic soil
metabolism S ulfometuron methyl 42091401 Acceptable
but incomplete 20 Partially Yes

835.4100 [162

- 1] Aerobic soil
metabolism S ulfometuron methyl 43174102
and
00 245375 Acceptable 13 Partially Yes

835.4200

[162

- 2] Anaerobic Soil
Metabolism NA NA ref 162

- 3 Yes No

835.4200

[162

- 3] Anaerobic aquatic
metabolism S ulfometuron methyl 42091402
and
43188601 Acceptable Yes No

835.4200

[162

- 3] Anaerobic aquatic
metabolism S ulfometuron methyl 4413010

- 20 (143540) Acceptable Yes No

835.4300

[162

- 4] Aerobic aquatic
metabolism S ulfometuron methyl 42091403
and
43174103 Acceptable Yes No

835.1240

[163

- 1] Adsorption/ Desorption S ulfometuron methyl 42789301 Acceptable Yes No

835.1240

[163

- 1] Adsorption/ Desorption (degradates) Pyrimidine
amine degradate 42789301 In Review 21

--- ---

S accharin degradate 42789301 In Review

--- ---

Sulfonamide

degradate 42789301 In Review

--- ---

None [163

- 2] Laboratory Volatility NA NA Waived 22 NA NA

None [163

- 3] Field Volatility NA NA Waived NA NA

835.6100

[164

- 1] (also see Terrestrial Field Dissipation Sulfometuron methyl 43212101
and
43637101 Acceptable Yes No

18 The initial photolysis study submitted was classified as supplemental; a replacement study was submitted and accepted to fully meet the 835.2240 data requirements.
19 Data requirement was waived based on sulfo met uron

- methyl’s low vapor pressure and Henry’s Law Constant.

20 Current guidelines require aerobic soil metabolism studies (Guideline 835.4100) in four test soils. The submitted studies are all only for one test soil and differ in the position of the radio label on the applied sulfometuron methyl.

21 Adsorption / desorption studies were submitted for three sulfometuron methyl degradates

– initial review indicates that these studies may have deficiencies and in Registration Review it will be determined whether additional data should be required to further understand the sorption characteristics of the degradates.
22 Data requirement was waived based on sulfomet uron

- methyl’s low vapor pressure and Henry’s Law Constant.

### 37 Guideline Data Requirement Test Material MRID Study
Classification Data Requirement
Met? More
Data
Needed? below)

835.6100
and
835.6300 ( Support

ing ) Environmental Chemistry
Methods in soil and water; Independent Lab.
Validation Sulfometuron methyl + degradates? 44035201; 43505001; 43505002;
43764801 Partial;(degrad
ate methods needed along with updated
parent methods) No Yes

835.6200

[164

- 2] Aquatic Field Dissipation No study NA NA NA NA

835.6 3 00

[164

- 3] (also see

above Forestry Dissipation Sulfometuron methyl 42091404
and
43174104 In review 23

--- ---

850.1730

[165

- 4] Accumulation in
Fish Waived 41418623
and
146279 NA NA NA

835.7100

[166

- 1] Ground Water Monitoring (small scale prospective) --- N/A NA NA No

[165

- 5] Accumulation in aquatic non

- target organism (crayfish) Waived NA NA NA NA

NA = not applicable * Only an Independent Laboratory Validation for the immunoassay method has been conducted, this method is not specific enough to fulfill the data requirement )

.



## Ecological Effects Data Requirements

Although a number of data gaps for ecological effects data requirements have been identified for
sulfometuron methyl, we are not requiring additional data; analysis is provided below.

Guideline 850.1025

– Acute toxicity estuarine/marine invertebrate (bivalve); Guideline
850.1035

– Acute toxicity estuarine/marine invertebrate (mysid) ; Gu ideline 850.107 5

– Acute t oxicity estuarine/marine fish : A cceptable acute toxicity data for an estuarine/marine bivalve, mysid, and fish are not available. Submitted studies for these data requirements with a
48

- hr IC 50 

### > 38.2 mg a.i. /L (MRID 41672805)

, a 48

- hr L C 50 

### > 44.8 mg a.i. /L ( MRID 41672803 )

, and a 48

- hr L C 50 

### > 45 mg a.i. /L (MRID 41672804) , respectively, are classified as supplemental due to high variability in measured test concentrations and uncertainty in exposure to dissolved sulfometuron methyl ( i.e. , test samples were not centrifuged prior to analysis). Although these

23 Data were submitted for the field dissipation of sulfometuron applied on forestry sites in a Gainesville, FL sand and a Scooba, MS silty clay loam and will be assessed to meet the requirements to meet field dissipation study requirements for this major u se of sulfometuron methyl.

### 38 deficiencies could have rendered the study classifications as invalid, the studies are considered to provide some useful information for the Registration Review ecological risk assessment ( i.e. , an indica tion of a lack of toxicity at or near solubility limits in te st solutions ). Furthermore, when
vie wed in the context of predicted EECs ( i.e. , a maximum peak concentration of 0.031 5 mg/L in

water, see Table 5 )
, the bioavailable (dissolved) portion sulfometuron methyl would have to be approximately 1200

- 1400 fold lower than the highest m easured test concentrations (~ 38

- 45 mg/L) for risks to be evident. Therefore, r epeating these studies would not likely affect the risk assessment conclusions, and new studies are not required.

Guideline 850.1350

– Estuarine/marine invertebrate life cycle: Aquatic invertebrate life cycle toxicity data for an estuarine/marine inver tebrate are required under 40 CFR Part 158 if the product is expected to enter the environment in significant concentrations because of its expected use or mobility patterns. No studies have been submitted for this data requirement. Given that
the acute toxicity of sulfometuron methyl to aquatic animals is very low (slightly to practically

non

- toxic), the NOEC for the freshwater invertebrate life cycle study ( MRID 41672806 ) 

### was set at the highest test concentration, and there is no evidence to indicate th at estuarine/marine
animals are substantially more sensitive to sulfometuron methyl than freshwater animals, fulfilling this data requirement has a low potential to add value to the R egistration R eview risk

assessment. In the absence of this data, toxicit y to estuarine/marine invertebrates from chronic exposure to sulfometuron methyl will be characterized using toxicity data for freshwater invertebrates. New study is not required.

Guideline 850.1400

– Estuarine/marine and freshwater fish early

- life stage: Early

- life stage toxicity data for a freshwater fish are required under 40 CFR Part 158 . E arly

- life stage toxicity data for an estuarine/marine fish are required under 40 CFR Part 158 if the product is expected to enter the environment in significant con centrations because of its expected use or mobility
patterns. No studies have been submitted for this data requirement. Given that the acute toxicity of sulfometuron methyl to aquatic animals is very low (sli ghtly to practically non

- toxic), the
NOEC for the freshwater invertebrate life cycle study ( MRID 41672806 ) 

### was set at the highest

tes t concentration, and there is no evidence to indicate that estuarine/marine animals are substantially more sensitive to sulfometuron methyl than fres hwater animals, fulfilling these data requirement s has a low potential to add value to the R egistration R eview risk assessment. In the absence of this data, toxicity to freshwater fish from chronic exposure to sulfometuron methyl will be estimated using a freshwater fish ACR for another sulfonylurea with a similar toxicity profile and the same mode of action ( e.g. , flazasulfu ron, PC code 119011 ; see 2008 RED, USEPA, 2008 ) to extrapolate from existing acute toxicity data for freshwater fish. For estuarine/marine fish, a s imilar approach may be taken

. A new study is not required.

Guideline 850.2100

– Avian oral toxicity, passerine species: A cute oral toxicity data for a passerine species a re required under the new 40 CFR Part 158. No studies have been submitted
for th is data requirement. T he acute toxicity of sulfometuron methyl to birds and mammals is very low (practically non

- toxic) . In addition, acute toxicity data for a passerine species is
available for flazasulfuron ( PC code 119011 ), a sulfonylurea with a similar toxicity profile and
the same mode of action as sulfometuron methyl. This study (MRID 47939912) indicates that flazasulfuron is practically non

- toxic to the zebra finch ( Taeniopygia guttata ) on an acute oral basis (LD 50 

### > 2000 mg a.i./kg

- bw ). The refore, fulfilling this data requirement has a low

### 39 potential to add value to the R egistration R eview risk assessment. In the absence of this data, toxicity to passerines from acute exposure to sulfometuron methyl will be characterized using all
acute toxi city data for other sulfonylureas with a similar toxicity profile and the same mode of
action that are available at the time of the R egistration R eview risk assessment. A passerine acute study with SMM is not required.

Guideline 850.2300

– Avian reproduct ion, upland game and waterfowl species: Avian reproductive toxicity data for water fowl and upland game species are required under 40 CFR
Part 158. No studies have been submitted for this data requirement. T he acute toxicity of sulfometuron methyl to bir ds and mammals is very low (practically non

- toxic) . In addition, there
is ample avian reproductive toxicity data available for other sulfonylurea s with a similar toxicity profile and the same mode of action ( e.g. , halosulfuron, PC code 128721, NOAEC = 1010 mg a.i./kg

- diet, MRIDs 47792801 and 47792802; primisulfuron, PC code 128973, NOAEC = 500 mg a.i./kg

- diet, MRID 40512004; rimsulfuron, PC code 129009, NOAEC = 1250 ppm,

D 358867, D358872 ; flazasulfuron, PC code 119011, NOAEC = 4 84 mg a.i./kg

- diet, MRID 46220975). Avian reproductive NOECs for these sulfonylureas are 1 to 2 orders of magnitude greater than the peak sulfometuron methyl EEC of 90 mg/kg

- diet (for birds consuming short grass) as calculated for the 2008 ecological risk assessment for the reregistration of sulfometuron methyl (USEPA, 2008) suggesting there is little concern for risk to birds from chronic exposure to sulfometuron methyl

. Therefore, fulfilling this data requirement has a low potential to add
value to the R egistration R eview risk assessment. In the absence of this data, toxicity to birds from chronic exposure to sulfometuron methyl will be characterized using chronic toxicity data
for other sulfonylurea s with a similar toxicity profile and the same mode of action . New studies are not required.

Non

- Guideline

– Special study for non

- target plant reproductive toxicity with TEP: A DCI for this study, previously published as a result of the 2008 RED for sulfometuron methyl, has not
been fulfilled. 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 850.4150 vegetative vigor guideline study are sufficiently

pro tective 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 inhibit ion 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

c oncentrations to those effects determined in the guideline vegetative vigor studies (850.4150). Therefore, fulfilling this DCI has a low potential to add value to the R egistration Review risk assessment, and a study is not required.

### 40 Table 9 provides ecological effects studies by MRI D that offer data to fulfill each guideline requirement as well as indicates whether or not further data are needed i n order to support the Registration Review ecological risk assessment ( i.e. , whether there is a data gap).

Table 9

. Ecological Effects Data Requirements for Sulfometuron Methyl and Remaining Data Gaps

. Guideline D ata Requiremen t Test
Substance MRID/
Citation Study
Classification Data Requirement
Met? More
Data
Needed?

850.1010 Acute toxicity
freshwater
invertebrates 99.6% 43501803 Acceptable Yes No

850.1025
850.1055 Acute toxicity
estuarine/marine
invertebrate (bivalve) 99.1% 41672805 Supplemental No No 1

850.1035
850.1045 Acute toxicity
estuarine/marine
invertebrate (crustacean) 99.1% 41672804 Supplemental No No 1

850.1075 Acute toxicity
freshwater fish (cold water species) 99.6% 43501802 Acceptable Yes No

Acute toxicity
freshwater fish (warm water species) 99.6% 43501801 Acceptable Yes No

Acute toxicity
estuarine/marine fish 99.1% 41672803 Supplemental No No 1

850.1300 Aquatic invertebrate life cycle (freshwater) 99.1% 41672806 Acceptable Yes No

850.1350 Aquatic invertebrate
life c ycle ( saltwater ) No data No No 1

850.1400 Fish early

- life s tage (freshwater) No data No No 1
Fish early

- life s tage ( saltwater ) No data No No 1

850.2100 Avian oral toxicity (upland game or waterfowl species) 93% 00078700 Acceptable Yes No

Avian oral toxicity (passerine species) No data No No 1

850.2200 Avian dietary toxicity (upland game species) 92.5% 00088813 Acceptable Yes No

Avian dietary toxicity (waterfowl species) 92% 00071414 Acceptable Yes No

850.2300 Avian reproduction (upland game species) No data No

No No 1

No 1 Avian reproduction (waterfowl species) No data

850.3020 Honeybee acute contact toxicity 99.8% 41672810 Acceptable Yes No

### 41 Guideline D ata Requiremen t Test
Substance MRID/
Citation Study
Classification Data Requirement
Met? More
Data
Needed?

850.4100 Seedling e mergence 95.72%

TEP 43538501 Acceptable Yes No

850.4150 Vegetative v igor 95.72%

TEP 43538501 Acceptable Yes No

Non

guideline Terrestrial p lant reproduction toxicity No data No No 1

850.4400 Aquatic p lant g rowth:
Vascular 85.72% 43538503 Acceptable Yes No 1

850.5400 Aquatic p lant g rowth:

Non

- v ascular 99.1%
99.16% 41680102
43538502 Acceptable Yes No 1

1 Additional data are not required. See below for analysis.

### 42 

# APPENDIX 1 . Submitted Environmental Fate and Effects Studies

Environmental Fate Studies

Guideline: 161

- 1 Hydrolysis

------------------------------------------------------------------------------------- MRID: 71419 Harvey, J., Jr.; Bennett, C.T.; Reiser, R.W. (19??) Hydrolysis of ^14IC

- DPX

- 5648. (Unpublished study received Jan 23, 1981 under 352

- EX

- 107; submitted by E.I. du Pont de Nemours & Co., Wilmington, Del.; CDL:244195

- U)

MRID: 71420 Harvey, J., Jr.; Bennett, C.T.; Reiser, R.W. (1980?) Photolysis of ^14IC

- DPX

- 5648: Document
No. AMR

- 01

- 81. (Unpublished study received Jan 23, 1981 under 35 2

- EX

- 107; submitted by E.I. du Pont de Nemours & Co., Wilmington, Del.; CDL:244195

- V)

MRID: 41418623 Harvey, J.; Dulka, J.; Anderson, J . (1985) Properties of Sulfome turon methyl affecting its
environmental fate: aqueous hydrolysis and photolysis, mobility and ads orption on soils and
bioaccumu lation potential. Journal of Agricultural Food Chemistry. 33: 590

- 596.

MRID: 41672811 Brattsen, L. (1987) Hydrolysis of ?Pyrimidine

- 2

- C14| Sulfometuron Methyl: Lab Project
Number: AMR

- 541

- 86. Unpublished study pre

- pared by E. I. du Pont de Nemours and Co. 40

p.

MRID: 42715201 Schneiders, G. (1993) Hydrolysis of (Phenyl

- carbon 14 (U)) and (Pyrimidine

- 2

- carbon 14))Sulfometuron Methyl in Buffer Solutions of pH 5, 7, and 9: Lab P roject Number: AMR
2426

- 92. Unpublished study prepared by E.I. du Pont de Nemours & Co. 48 p.
MRID: 93206022 Harvey, J. (1990) E.I. du Pont De Nemours Co. Phase 3 Summary of MRID 00071419. Hydrolysis of Sulfometuron Methyl: AMR 2

- 81,AMR

- 1819

- 90. Prepar ed by E.I. DU PONT DE NEMOURS CO. INC. 11 p.

Guideline: 161

- 2 Photodegradation

- water

------------------------------------------------------------------------------------- MRID: 41418623 Harvey, J.; Dulka, J.; Anderson, J. (1985) Properties of Sulf ome

- turon methyl affecting its
environmental fate: aqueous hydrolysis and photolysis, mobility and ads orption on soils and
bioaccumu lation potential. Journal of Agricultural Food Chemistry. 33: 590

- 596.

MRID: 41672812

### 43 Naidu, M. (1990) Aqueous Photolys is of (Pyrimidine

- 2

- C14) Sulfometuron Methyl: Lab Project
Number: AMR

- 564

- 86. Unpublished study prepared by E. I. Du Pont de Nemours and Co. 43 p.

MRID: 42182401 Schneiders, G.; Bachmura, S. (1992) Photodegradation of Phenyl

- Carbon 14(U) and ?Pyrimidi ne

- 2

- carbon 14| Sulfometuron Methyl in Water

-- Conducted in Simulated Sunlight: Lab Project Number: AMR 2179

- 91. Unpublished study prepared by E.I. du Pont de Nemours and Co. 48 p.

MRID: 43174101 Schneiders, G. (1994) Photodegradation of (Phenyl

- (carbo n 14)(U)) and (Pyrimidine

- 2

- (carbon 14)) Sulfometuron Methyl in Water Conducted in Simulated Sunlight: Supplement: Lab Project
Number: AMR 2179

- 91. Unpublished study prepared by DuPont Agricultural Products. 18 p.

Guideline: 161

- 3 Photodegradati on

- soil

------------------------------------------------------------------------------------- MRID: 137864 Hardesty, P. (1983) Soil Photolysis of Sulfometuron Methyl: Docu

- ment No. AMR

- 123

- 83. (Unpublished study received Apr 12, 1984 under 352

- 401; subm itted by E.I. du Pont de Nemours & Co., Inc., Wilmington, DE; CDL:252941

- C)

MRID: 41420601 Ryan, D.; Atkins, B. (1986) Photodegradation of ?Phenyl(U)

- Carbon 14|Sulfometruron Methyl and ?Pyrimidine

- 2

- Carbon 14|Sulfometuron Methyl on Soil: Lab Project Num ber: AMR

- 573

- 86. Unpublished study prepared by E. I. du Pont de Nemours and Co. 35 p.

MRID: 41680103 Ryan, D.; Atkins, B. (1986) Aged Soil Column Leaching Study with ?Phenyl(U)

- carbon 14|Sulfometuron Methyl and Pyrimidine

- 2

- ?car

- bon 14|Sulfometuron m ethyl: Lab Project
Number: AMR/643/86. Un

- published study prepared by E. I. du Pont de Nemours & Co. 35 p.

MRID: 42385707 Ryan, D.; Atkins, B. (1987) Photodegradation of ?Phenyl(U)

- ?carbon 14||

- Sulfometuron Methyl and ?Pyrimidine

- 2

- ?carbon 14||

- Sulfome turon Methyl on Soil: Supplement No. 1: Lab Project
Number: AMR 573

- 86. Unpub

- lished study prepared by E. I. du Pont de Nemours and Co. 15

p.

MRID: 93206023 Cadwgan, G. (1990) E.I. du Pont De Nemours Co. Phase 3 Summary of MRID 41420601. Photodegrada tion of Sulfometuron Methyl on Soil: du Pont Report No. AMR

- 573

- 86, AMR

1861

- 90. Prepared by E.I. DU PONT DE NEMOURS CO. INC. 12 p.

Guideline: 162

- 1 Aerobic soil metabolism

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

### 44 MRID: 78701 Anderson, J.J. (1980) Microbial Metabolism of ^14IC

- Phenyl Labeled DPX

- 5648 in a Viable Soil Ecosystem: Document No. AMR

- 34

- 81. (Unpublished study received Jun 17, 1981 under
352

- EX

- 108; sub

- mitted by E.I. du Pont de Nemours & Co ., Wilmington, Del.; CDL: 245375

- B)

MRID: 42091401 Monson, K.; Hoffman, D. (1990) Aerobic Soil Metabolism of ?Pyrimid

- ine

- 2

- Carbon 14|Sulfometuron: Methyl in Keyport Silt Loam: Lab Project Number: AMR

- 1113

- 88. Unpublished study prepared by E.I. du Pon t de Nemours and Co. 42 p.

MRID: 43174102 Anderson, J. (1994) Microbial Metabolism of (carbon 14)

- Phenyl

- Labeled DPX

- T5648 in a Viable Soil Ecosystem: Supplement: Lab Project Number: AMR 34

- 81. Unpublished study prepared by DuPont Agricultural Product s. 7 p.

MRID: 93206024 Anderson, J. (1990) E.I. du Pont De Nemours Co. Phase 3 Summary of MRID 00078701. Microbial Metabolism of [Carbon 14]

- Phenyl

- Labeled DPX

- T5648 in a Viable Soil Ecosystem: du Pont Report Nos. AMR 34

- 81, AMR

- 1846

- 90. Prepared by E.I. DU PONT DE NEMOURS CO. INC. 10 p.

Guideline: 162

- 2 Anaerobic soil metabolism

------------------------------------------------------------------------------------- MRID: 143540 Dulka, J.; Anderson, J. (1982) The Fate of [Carbon radiolabeled]

- DPX

- T5648 in an Anaerobic Environment. Unpublished study pre

- pared by E. I. du Pont de Nemours and Co., Inc. 28 p.

Guideline: 162

- 3 Anaerobic aquatic metab.

------------------------------------------------------------------------------------- MRID: 78703 Anderson, J.J.; Dulka, J.J.; Harvey, J., Jr. (1981) Metabolism/ Environmental Fate Studies with
^14IC

- DPX

- 5648: Document No. AMR

- 35

- 81. Interim summary rept. (Unpublished study re

ceived 17, 1981 under 352

- EX

- 108; submitted by E.I. du Pont de Nemours & Co., Wilmington, Del.; CDL:245375

- D)

MRID: 143540 Dulka, J.; Anderson, J. (1982) The Fate of [Carbon radiolabeled]

- DPX

- T5648 in an Anaerobic Environment. Unpublished study pre

- pared by E. I. du Pont de Nemours and Co., Inc. 28 p.

MRI D: 42091402 Fallon, R. (1989) Anaerobic Aquatic Metabolism of (Pyrimidine

- 2

- Carbon 14) Sulfometuron Methyl in Landenberg, Pennsylvania and Bradenton, Florida Pond Water and Sediment Systems:

### 45 Lab Project Number: AMR 1084

- 88: 587

- 87. Unpublished study pre pared by E.I. du Pont de Nemours and Co., Haskell Lab for Toxicology and Industrial Medicine. 64 p.

MRID: 43188601 McCord, E. (1994) Anaerobic Aquatic Metabolism of (Pyrimidine

- 2

- (carbon 14))Sulfometuron Methyl in Landenberg, Pennsylvania and Bradenton , Florida Pond Water and Sediment Systems: Supplement: Lab Project Number: AMR 1084

- 88: 587

- 87: 7831

- 001. Unpublished study prepared by Haskell Laboratory for Toxicology and Industrial Medicine, E.I. du Pont de Nemours and Co., Inc. 26 p.

MRID: 932060 25 Anderson, J. (1990) E.I. du Pont De Nemours Co. Phase 3 Summary of MRID 00143540. The Fate of [Carbon 14]DPX

- T5648 in an Anaerobic Environment: du Pont Report No. 65

- 82, AMR

1848

- 90. Prepared by E.I. DU PONT DE NEMOURS CO. INC. 10 p.

Guideline: 16 2

- 4 Aerobic aquatic metab.

------------------------------------------------------------------------------------- MRID: 42091403 Rhodes, B. (1991) Aerobic Aquatic Metabolism of Carbon 14

- Sulfometuron Methyl: Lab Project
Number: AMR

- 1896

- 90. Unpublish ed study prepared by E.I. du Pont de Nemours and Co. 40

p.

MRID: 43174103 Rhodes, B. (1994) Aerobic Aquatic Metabolism of (Carbon 14)

- Sulfometuron Methyl: Supplement: Lab Project Number: AMR 1896

- 90. Unpublished study prepared by DuPont Agricultural P roducts. 7 p.

Guideline: 163

- 1 Leach/adsorp/desorption

------------------------------------------------------------------------------------- MRID: 71423 Dulka, J.J.; Rapisarda, C.; Babineaux, B. (19??) Adsorption/Desorption Studies of (Carbon 14 )

- Phenyl (UL)

- Labeled DPX

- 5648 on Soil and Partitioning of DPX

- 5648 between Octanol and HI2^0 (KIow^): Document No. AMR

- 25

- 80. (Unpublished study received Jan 23, 1981 under
352

- EX

- 107; prepared in cooperation with Univ. of Delaware, College of Agricultur al Sciences, submitted by E.I. du Pont de Nemours & Co., Wilmington, Del.; CDL:244195

- Y)

MRID: 78702 Dulka, J.J. (1981) Mobility of (Carbon 14)

- Phenyl Labeled DPX

- 5648 in Soil; Soil Column Leaching Studies: AMR

- 11

- 81. (Unpublished study received Jun 17 , 1981 under 352

- EX

- 108; submitted by E.I. du Pont de Nemours & Co., Wilmington, Del.; CDL:245375

- C)

MRID: 78706 Dulka, J.J. (1980) Dissipation of ^14IC

- DPX

- 5648 in the Field: Document No. AMR

- 35

- 81

- C.

### 46 Interim rept. (Unpublished study received Jun 17 , 1981 under 352

- EX

- 108; submitted by E.I. du Pont de Nemours & Co., Wilmington, Del.; CDL:245375

- G)

MRID: 41418623 Harvey, J.; Dulka, J.; Anderson, J. (1985) Properties of Sulfome

- turon methyl affecting its environmental fate: aquous hydrolysis and ph otolysis, mobility and adsorption on soils and
bioaccumu

- lation potential. Journal of Agricultural Food Chemistry. 33: 590

- 596.

MRID: 42789301 Kraut, G. (1993) Batch Equilibrium (Adsorption/Desorption) Study of (Phenyl(U)

-- (carbon 14))Sulfometuron Meth yl, IN

- X993, IN

- D5803, and Saccharin: Lab Project Number: AMR
2607

- 93. Unpublished study prepared by E.I. duPont de Nemours and Co. 84 p.

MRID: 93206026 Cadwgan, G. (1990) E.I. du Pont De Nemours Co. Phase 3 Summary of MRID 00071423 and
Related MRIDs 0 0078702. Soil Mobility of Sulfometuron Methyl: AMR

- 25

- 80,AMR

- 11

- 81. Prepared by E.I. DU PONT DE NEMOURS CO. INC. 12 p.

Guideline: 163

- 2 Volatility

- lab

------------------------------------------------------------------------------------- MRID: 41418623 Harvey, J.; Dulka, J.; Anderson, J. (1985) Properties of Sulfome

- turon methyl affecting its environmental fate: aquous hydrolysis and photolysis, mobility and adsorption on soils and
bioaccumu

- lation potential. Journal of Agricultural Food Chem istry. 33: 590

- 596.

Guideline: 164

- 1 Terrestrial field dissipation

------------------------------------------------------------------------------------- MRID: 78705 Anderson, J.J. (1980) Terrestrial Field Dissipation Study of ^14IC

- DPX

- 5648 in De laware, North Carolina, and Mississippi Soils: Document No. AMR

- 35

- 81

- B. Interim rept. (Unpublished study received Jun 17, 1981 under 352

- EX

- 108; submitted by E.I. du Pont de Nemours & Co., Wilmington, Del.; CDL:245375

- F)

MRID: 94840 Anderson, J.J. (1 981) Terrestrial Field Dissipation Study of ^14IC

- DPX

- T5648 in Delaware, North Carolina, and Mississippi: Document No. AMR

- 59

- 81. (Unpublished study received Feb 11, 1982 under 352

- 401; submitted by E.I. du Pont de Nemours & Co., Inc., Wilmington, Del.;
CDL:246795

- A)

MRID: 43212101 Trubey, R. (1994) Field Soil Dissipation on Oust Herbicide: Sulfometuron Methyl: Lab Project
Number: AMR/1922/91: DUPDE01B

- 2. Unpublished study prepared by E.I. du Pont de Nemours and Co. and Alta Analytical Lab., Inc. 11 51 p.

### 47 MRID: 43253501 Wauchope, R.; Williams, R.; Marti, L. (1988) Runoff of Sulfometuron Methyl and Cyanazine from Small Plots: Effects of Formulation and Grass Cover. Journal of Environmental Quality
19:119

- 125.

MRID: 43637101 Trubey, R. (1995) Fie ld Soil Dissipation of Oust Herbicide: Supplement No. 1 to Revision No. 1: Lab Project Number: AMR 1922

- 91: DUPDE01B

- 2. Unpublished study prepared by DuPont Agricultural Products and Alta Analytical Labs, Inc. 120 p.

MRID: 93206027 Anderson, J. (1990 ) E.I. du Pont De Nemours Co. Phase 3 Summary of MRID 00094840. Terrestrial Field Dissipation Study of [Carbon 14]

- DPX

- T5648 in Delaware, North Carolina, and Mississippi: du Pont Report No. AMR

- 59

- 81,AMR

- 1847

- 90. Prepared by E.I. DU PONT DE
NEMOURS CO. I NC. 10 p.

Guideline: 164

- 3 Forest field dissipation

------------------------------------------------------------------------------------- MRID: 42091404 Michael, J.; Neary, D. (1991) Movement of Sulfometuron Methyl in Forest Watersheds After
Aeri al Application of Oust for Herbaceous Weed Control (75% Dispersible Granule): Lab Project Number : AMR

- 1641

- 90. Unpublished study prepared by Auburn University Southern Forest Experiment Station. 172 p.

MRID: 43174104 Trubey, R. (1994) Movement of Sul fometuron Methyl in Forest Watersheds After Aerial Application of Oust for Herbaceous Weed Control (75% Dispersible Granule): Lab Project
Number: AMR 1641

- 90. Unpublished study prepared by Southern Forest Experiment Station, Auburn University and DuPont A gric. Products. 38 p.

MRID: 43174105 Trubey, R.; Devine, P. (1994) Storage Stability of Sulfometuron Methyl in Soil (Frozen) and in Water (Frozen, Refrigerated, and Room Temperature): Lab Project Number: AMR 1586

- 90: 02

- 9002. Unpublished study prepared by DuPont Agricultural Products and Minnesota Valley Testing Laboratories, Inc. 79 p.

MRID: 43492501 Trubey, R. (1994) Movement of Sulfometuron Methyl in Forest Watersheds After Aerial Application of Oust for Herbaceous Weed Control (75 (percent) Disp ersible Granule): Supplement No. 2: Lab Project Numbers: FS

- SO

- 4105

- 1.19: AMR 1641

- 90. Unpublished study prepared by Auburn University. 143 p.

### 48 Guideline: 165

- 1 Confined rotational crop

------------------------------------------------------------ ------------------------- MRID: 47459401 Swanson, M. (1988) Confined Accumulation Study of [carbon 14]

- Sulfometuron Methyl of Rotational Crops. Project Number: AMR/956/87. Unpublished study prepared by DuPont Experiment Station Laboratories. 42 p.

Gu ideline: 165

- 4 Bioaccumulation in fish

------------------------------------------------------------------------------------- MRID: 146279 Harvey, J. (1981) Bioaccumulation Studies of [Carbonradiolabeled]

- Phenyl

- DPX

- 5648 in Fish. Unpublished study prepared by E. I. du Pont de Nemours and Co., Inc. 15 p.

MRID: 41418623 Harvey, J.; Dulka, J.; Anderson, J. (1985) Properties of Sulfome

- turon methyl affecting its environmental fate: aquous hydrolysis and photolysis, mobility and adsorption on soils and
bioaccumu

- lation potential. Journal of Agricultural Food Chemistry. 33: 590

- 596.

MRID: 93206028 Harvey, J. (1990) E.I. du Pont De Nemours Co. Phase 3 Summary of MRID 00146279. Bioaccumulation of Sulfometuron Methyl in Fish: AMR

- 41

- 81,AMR

- 1820

- 90 . Prepared by E.I. DU PONT DE NEMOURS CO. INC. 11 p.

Guideline: 171

- 4B Residue Analytical Methods

------------------------------------------------------------------------------------- MRID: 44035201 Powley, C.; de Bernard, P. (1996) Analytical Method for the Determination of Azimsulfuron, Bensulfuron Methyl, Chlorimuron Ethyl, Ethametsulfuron Methyl, Sulfometuron Methyl, and Triflusulfuron Methyl in Water: Lab Project Number: AMR 3720

- 95. Unpublished study prepared by E. I. du Pont de Nemours a nd Co. 60 p.

MRID: 71421 Citation: Anderson, J.J.; Berg, D.S. (1980?) Studies To Determine the Effect of DPX

- 5648 on
Metabolic Processes of Soil Microbes: Document No. AMR

- 01

- 81. (Unpublished study received Jan 23, 1981 under 352

- EX

- 107; prepared in cooperation with Univ. of Delaware, College of Agricultural Sciences, submitted by E.I. du Pont de Nemours & Co., Wilmington, Del.; CDL:244195

- W)

MRID: 71422 Citation: Hadley, B.A.; Bembry, R.P.; Larsen, J.M.; et al. (19??) The Effect of DPX

- 5648 on
So il Microorganism Populations. (Unpublished study received Jan 23, 1981 under 352

- EX

- 107; prepared in co

- operation with Univ. of Delaware, Soil Testing Laboratory, sub

- mitted by E.I.

### 49 du Pont de Nemours & Co., Wilmington, Del.; CDL:244195

- X)

MRID: 7870 4 Citation: Harvey, J., Jr. (1981) Aerobic Soil Metabolism of ?^14IC|

- Phenyl

- DPX

- 5648:
Document No. AMR

- 35

- 81

- A. Interim rept. (Unpublished study received Jun 17, 1981 under
352

- EX

- 108; submitted by E.I. du Pont de Nemours & Co., Wilmington, Del.; CDL: 245375

- E)

MRID: 78707 Citation: Dulka, J.J. (1980) The Fate of ?^14IC|

- DPX

- 5648 in an Anaerobic Environment:
Document No. AMR

- 35

- 81

- D. Interim rept. (Un

- published study received Jun 17, 1981 under
352

- EX

- 108; submit

- ted by E.I. du Pont de Nemours & Co., Wilmington, Del.; CDL: 245375

- H)

MRID: 78710 Citation: Harvey, J., Jr. (1981) Bioaccumulation Studies of ?^14IC|

- Phenyl

- DPX

- 5648 in Fish:
Document No. AMR

- 35

- 81

- F. Interim rept. (Unpublished study received Jun 17, 1981 under
352

- EX

- 108; sub

- mi tted by E.I. du Pont de Nemours & Co., Wilmington, Del.; CDL: 245375

- K)

MRID: 137863 Citation: Harvey, J. (1981) Bioaccumulation Studies of 14C

- Phenyl

- DPX

- 5648 in Fish:
Document No. AMR

- 41

- 81. (Unpublished study received Apr 12, 1984 under 352

- 401;

su bmitted by E.I. du Pont de Nemours & Co., Inc., Wilmington, DE; CDL:252941

- B)

MRID: 43039601 Citation: Whitcomb, C. (1991) (Compilation Concerning the Use of Sulfonylurea

- type Herbicides and the Fate and Effects in plants and the Environment). Unpubli shed study. 264 p.

### 50 

# SUBMITTED EFFECTS STUDIES:

Guideline: 71

- 1 Avian Single Dose Oral Toxicity

------------------------------------------------------------------------------------- MRID: 78700 Dudeck, S.H.; Bristol, K.L. (1981) Final Re port: Single

- dose Oral Toxicity in Mallard Ducks: Project No. 201

- 552. (Unpublished study received Jun 17, 1981 under 352

- EX

- 108; prepared by
Hazle

- ton Laboratories America, Inc., submitted by E.I. du Pont de Nemours & Co., Wilmington, Del.; CDL:245375

- A )

Guideline: 71

- 2 Avian Dietary Toxicity

------------------------------------------------------------------------------------- MRID: 71414 Dudeck, S.H.; Twigg, C.J. (1980) Final Report: Avian Dietary Toxic

- ity (LC50) Study in Mallard Ducks: Proje ct No. 201

- 548; HLO

- 788

- 80. (Unpublished study received Jan 23, 1981
under 352

- EX

- 107; prepared by Hazleton Laboratories America, Inc., submitted by E.I. du Pont de Nemours & Co., Wilmington, Del.; CDL:244195

- P)

MRID: 71415 Dudeck, S.; Bristol, K.L. ( 1981) Final Report: Avian Dietary Toxic

- ity Study in Bobwhite Quail: Project No. 201

- 549; HLO

- 17

- 81. (Unpublished study received Jan 23, 1981 under 352

- EX

- 107; pre

- pared by Hazleton Laboratories America, Inc., submitted by E.I. du Pont de Nemours & Co., Wilmington, Del.; CDL:244195

- Q)

MRID: 88813 Fink, R.; Beavers, J.B.; Joiner, G.; et al. (1981) Final Report: Eight

- day Dietary LCI50^

-- Bobwhite Quail: H

- 13,647

- 03: Project No. 112

- 122. (Unpublished study received Dec 12, 1981
under 352

- 401; prepared by Wildlife International, Ltd., submitted by E.I. du Pont de Nemours & Co., Inc., Wilmington, Del.; CDL: 246409

- A)

Guideline: 72

- 1 Acute Toxicity to Freshwater Fish

----------------------------------------------------------------------------------- -- MRID: 71416 Muska, C.F.; Trivits, R.L. (1980) 96

- hour LC50 to Rainbow Trout: Haskell Laboratory Report
No. 630

- 80. (Unpublished study re

- ceived Jan 23, 1981 under 352

- EX

- 107; submitted by E.I. du Pont de Nemours & Co., Wilmington, Del.; CDL:244195

- R)

MRID: 71417 Muska, C.F.; Hall, C.L. (1980) 96

- hour LC50 to Bluegill Sunfish: Haskell Laboratory Report
No. 629

- 80. (Unpublished study received Jan 23, 1981 under 352

- EX

- 107; submitted by E.I. du Pont de Nemours & Co., Wilmington, Del.; CDL:244195

- S)

MRID: 143539 Driscoll, R. (1984) Early Life Stage Toxicity of INT

- 5648

- 18 to Fathead Minnow: Report No.
765

- 82. Unpublished study prepared by Haskell Laboratory. 29 p.

### 51 MRID: 43501801 Brown, M. (1994) Static, Acute, 96

- Hour LC50 of DPX

- T5648

- 42 (Sul fometuron Methyl) to Bluegill Sunfish, Lepomis macrochirus: (Limit Test): Lab Project Numbers: 9868

- 001: 590

- 94:
HLR 590

- 94. Unpublished study prepared by E.I. du Pont de Nemours and Co. 27 p.

MRID: 43501802 Brown, M. (1994) Static, Acute, 96

- Hour LC5 0 of DPX

- T5648

- 42 (Sulfometuron Methyl) to Rainbow Trout, Oncorhynchus mykiss: (Limit Test): Lab Project Numbers: 9868

- 001: 589

- 94:
HLR 589

- 94. Unpublished study prepared by E.I. du Pont de Nemours and Co. 28 p.

Guideline: 72

- 2 Acute Toxicity to Freshwater Invertebrates

------------------------------------------------------------------------------------- MRID: 71418 Muska, C.F.; Trivits, R.L. (1980) 48

- hour LC50 to Daphnia Magna: Haskell Laboratory Report
No. 631

- 80. (Unpublished study re

- ceiv ed Jan 23, 1981 under 352

- EX

- 107; submitted by E.I. du Pont de Nemours & Co., Wilmington, Del.; CDL:244195

- T)

MRID: 145514 Wetzel, J. (1984) 48

- Hour EC50 to Daphnia Magna: Report No. 147

- 84. Unpublished study prepared by Haskell Laboratory. 5 p.

M RID: 43501803 Brown, M. (1994) Static, Acute, 96

- Hour LC50 of DPX

- T5648

- 42 (Sulfometuron Methyl) to Daphnia magna: (Limit Test): Lab Project Numbers: 9868

- 001: 588

- 94: HLR 588

- 94. Unpublished study prepared by E.I. du Pont de Nemours and Co. 26 p.

Gu ideline: 72

- 3 Acute Toxicity to Estuarine/Marine Organisms

------------------------------------------------------------------------------------- MRID: 41672803 Ward, T.; Boeri, R. (1990) Static Acute Toxicity of IN T5648

- 40 to the Sheepshead Minnow, Cyprinodon variegatus: Lab Project Num

- ber: 4581

- 804: 90108

- DU. Unpublished study prepared by Resource Analysts, Inc. 32 p.

MRID: 41672804 Ward, T.; Boeri, R. (1990) Static Acute Toxicity of IN 75648

- 40 to the Mysid, Mysidopsis bahia: Lab Project Nu mber: 615

- 90: 90109

- DU. Unpublished study prepared by Resource Analysts, Inc. 32 p.

MRID: 41672805 Ward, T.; Boeri, R. (1990) Static Acute Toxicity of IN T5648

- 40 to Bivalve Mollusc Embryos and Larvae: Lab Project Number: 633

- 90: 90110

- DU. Unpublishe d study prepared by Resource Analysts, Inc. 31 p.

### 52 Guideline: 72

- 4 Fish Early Life Stage/Aquatic Invertebrate Life Cycle Study

------------------------------------------------------------------------------------- MRID: 126600 Muska, C.; Driscoll, R. (1982) Early Life Stage Toxicity of Int

- 5648

- 18 to Fathead Minnow: Haskell Laboratory Report No. 765

- 82. (Unpublished study received Mar 28, 1983 under 352

- 401; submit

- ted by E.I. du Pont de Nemours & Co., Inc., Wilmington, DE; CDL:249796

- A)

MRID: 143539 Driscoll, R. (1984) Early Life Stage Toxicity of INT

- 5648

- 18 to Fathead Minnow: Report No.
765

- 82. Unpublished study prepared by Haskell Laboratory. 29 p.

MRID: 41672806 Baer, K. (1990) Chronic Toxicity of IN T5648

- 40 to Daphnia magna: Lab Pro ject Number: 614

- 90: MR

- 4581

- 804. Unpublished study pre

- pared by Haskell Laboratory. 260 p.

Guideline: 122

- 1 Seed Germination/Seedline Emergence and Vegetable Vigor

------------------------------------------------------------------------------- ------ MRID: 41672809 Drake, D. (1990) Tier Testing Evaluation of Sulfometuron Methyl on Plants Grown under Greenhouse: Lab Project Number: DCD

- 90

- 2. Unpublished study prepared by E. I. Du Pont de Nemours and Co. 13 p.

MRID: 43538501 McKelvey, R. (1995 ) Influence of Sulfometuron Methyl (DPX

- T5648) on Seedling Emergence and Vegetative Vigor of Several Terrestrial Plants: Lab Project Number: AMR 2871

- 93. Unpublished study prepared by DuPont Agricultural Products. 415 p.

Guideline: 122

- 2 Aquatic p lant growth

------------------------------------------------------------------------------------- MRID: 41680102 Hoberg, J. (1990) Sulfometuron methyl

- Toxicity to the Freshwater Green Alga Selenastrum capricornutum: Lab Project Number: AMR

- 1893

- 90. Unpu blished study prepared by Springborn Laboratories, Inc. 24 p.

MRID: 43538502 Thompson, S. (1994) Sulfometuron Methyl (DPX

- T5648): Influence on Growth and Reproduction of Three Select Algal Species: Lab Project Number: AMR 2892

- 93: 112A

- 121. Unpublishe d study prepared by Wildlife International and Haskell Lab for Toxicology and Industrial Medicine. 58 p.

Guideline: 123

- 1 Seed germination/seedling emergence and vegetative vigor

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

### 53 MRID: 41672809 Drake, D. (1990) Tier Testing Evaluation of Sulfometuron Methyl on Plants Grown under Greenhouse: Lab Project Number: DCD

- 90

- 2. Unpublished study prepared by E. I. Du Pont de Nemours and Co. 13 p.

MRID: 43228101 Cain, J. (1994) Letter Sent to Office of Pesticide Programs dated May 5, 1994: Report of supplementary study information: DuPont Sulfometuron Methyl, DuPont Oust Herbicide: (Terrestrial Tier II Non

- target testing: plant studies: AMR 2871

- 93). Prepared by DuPont Agricultural Products. 3 p.

MRID: 43538501 McKelvey, R. (1995) Influence of Sulfometuron Methyl (DPX

- T5648) on Seedling Emergence and Vegetative Vigor of Several Terrestrial Plants: Lab Project Number: AMR 2871

- 93. Unpublished study prepared by DuPont Agricultural Products. 415 p.

Guideline: 123

- 2 Aquatic plant growth

------------------------------------------------------------------------------------- MRID: 43538502 Thompson, S. (1994) Sulfometuron Methyl (DPX

- T5648): Influence on Growth and Reproduction of Three Select Algal Species: Lab Project Number: AMR 2892

- 93: 112A

- 121. Unpublished study prepared by Wildlife International and Haskell Lab for Toxicology and Industrial Medicine. 58 p.

MRID: 43538503 Kannuck, R.; Sloman, T. (1995) Su lfometuron Methyl (DPX

- T5648): Influence on Growth and Reproduction of Lemna gibba G3: Lab Project Number: AMR 2902

- 94. Unpublished study prepared by Stine

- Haskell Research Center. 41 p.

Guideline: 141

- 1 Honey bee acute contact

----------------- -------------------------------------------------------------------- MRID: 41672810 Hoxter, K. ; Smith, G. (1990) An Acute Contact Toxicity Study with the Honey Bee: Lab Project
Number: 112

- 243: 583

- 90. Unpublished study prepared by Wildlife Internationa l Ltd. 14 p.



## Analytical Methods

MRID: 43505001 Citation: Trubey, R.; Sund, R. (1994) An ELISA Immunoassay Method for the Determination of Residues of Sulfometuron Methyl in Soil and Water: Lab Project Number: AMR 3066

- 94. Unpublished study prepar ed by DuPont Agricultural Products. 116 p.

MRID: 43505002

### 54 Citation: Trubey, R.; Bethem, R.; Peterson, B. (1994) An LC/MS Method for the Determination of Residues of Sulfometuron Methyl in Soil and Water: Lab Project Number: AMR 3164

- 94: 13710. Unpubl ished study prepared by Alta Analytical Lab. 110 p.

MRID: 43764801 Citation: Trubey, T.; Sund, R.; Hill, S. (1995) Analytical Method for the Determination of Residues of Sulfometuron Methyl in Soil and Water, Using Supercritical Fluid Extraction: Lab Project Number: AMR 2498

- 92. Unpublished study prepared by DuPont Ag Products. 72 p.

### 55 

# A PPENDIX 2 : Structures and Chemical Names of Sulfometuron methyl Metabolites

Chemical Structures
Trivial or common names Company ID or similar alternate names
Full chemical names

Sulfometuron methyl

DPX

- T5648; DPX

- 5648; IN

- T5648 ; IN
T5648

- 18 Methyl 2

- (4,6

- dimethylpyrimidin

- 2

-

ylcarbamoylsulfamoyl)benzoate Saccharin

IN

- 581 1,2

- Benzisothiazol

- 3(2H)

- one, 1,1

- dioxide

Sulfometuron pyrimidine amine

IN

- X 0 993; IN

- X993; PA 4,6

- Dimethyl

- 2

- pyrimidinamine 4,6

- dimethyl

- 2

- pyrimidinamine Sulfometuron sulfonamide

IN

- D5803; SA; methyl phenylsulfonamide Methyl 2

- (aminosulfonyl)benzoate.
2

- (Aminosulfonyl)

- benzoic acid, methyl ester

### 56 Pyrimidine

- ol

IN

- 11859 4,6

- Dimethyl

- 2

- pyrimidinol Sulfometuron free acid

FA

- SM; IN

- T6385
2

- [[[[(4,6

- Dimethyl

- 2

- pyrimidinyl)amino]carbonyl]amino]sulfonyl]

- benzoic acid

Free acid Sulfonamide

FA

- Sulfonamide; Free acid; IN

- D5119
2

- (Aminosulfonyl)benzoic acid 

## O O H

S

O O

N

H H

### 57 

# APPENDIX 3

. Uncertainties Related to the Use of Incident Information from the Ecological Incident Information System

Incident data are used in risk assessments to provide evidence that the risk predictions from the screening level assessment are supporte d by actual effects in the field. Incident reports submitted to EPA since approximately 1994 have been tracked by assignment of incident numbers in an Incident Data System (IDS), microfiched, and then entered to a second database, the Ecological Incident Information System (EIIS). Additionally, there is an on

- going effort to enter information to EIIS on incident reports received prior to establishment of current databases. Incident reports are not received in a consistent format ( e.g ., states and various labs usually have their own formats), may involve multiple incidents involving multiple chemicals in one report, and may report on only part of a given incident investigation ( e.g ., residues).

Incidents entered into EIIS are categorized into one of sev eral certainty levels regarding the likelihood that a particular pesticide is associated with the incident: highly probable, probable, possible, unlikely, or unrelated. In brief, “highly probable” incidents usually require carcass
residues and/or clear ci rcumstances regarding the exposure. “Probable” incidents include those where residues were not available and/or circumstances were less clear than for “highly probable.” “Possible” incidents include those where multiple chemicals may have been involved

an d it is not clear what the contribution was of a given chemical. The “unlikely” category is used, for example, where a given chemical is practically nontoxic to the category of organism killed and/or the chemical was tested for but not detected in samples . “Unrelated” incidents are those that have been confirmed to be not pesticide

- related.

Incidents entered into the EIIS are also categorized as to use/misuse. Unless specifically confirmed by a state or federal agency to be misuse, or there was very cle ar misuse such as intentional baiting to kill wildlife, incidents are not typically considered misuse.

The number of documented kills in EIIS is believed to be a small fraction of total mortality caused by pesticides. Mortality incidents must be seen, reported, investigated, and have investigation reports submitted to EPA to have the potential for entry into the database. Incidents often are not seen, due to scavenger removal of carcasses, decay in the field, or simply because carcasses may be hard to see on many sites and/or few people are systematically looking. Poisoned animals may also move off

- site to less conspicuous areas before dying. Incidents may not get reported to appropriate authorities capable of investigating the incident for a variety of reasons including the finder may not know of the importance of reporting incidents, may not know who to call, may not feel they have the time or desire to call, or may hesitate to call because of their own involvement in the kill. Incidents reported ma y not get investigated if resources are limited or may not get investigated thoroughly, with residue analyses, for example. Also, if kills are not reported and investigated promptly, there will be little chance of documenting the cause, since tissues and residues may deteriorate quickly. Reports of investigated incidents often do not get submitted to EPA, since reporting by states is voluntary.

Furthermore, the database relies heavily on registrant

- submitted incident reports, and registrants

are curren tly only required to submit detailed information on ‘major’ ecological incidents, while ‘minor’ incidents are reported aggregately.

### 58 Based on the 40 CFR (§159.184 Toxic or adverse effect incident reports), an ecological incident is considered ‘major’ if a ny of the following criteria are met:

Fish or wildlife :

(A) Involves any incident caused by a pesticide currently in Formal Review for ecological concerns.

(B) Fish: Affected 1,000 or more individuals of a schooling species or 50 or more
individuals of a non

- schooling species.

(C) Birds: Affected 200 or more individuals of a flocking species, or 50 or more individuals of a songbird species, or 5 or more indi viduals of a predatory species.

(D) Mammals, reptiles, amphibians: Affected 50 or more individuals of a relatively common or herding species or 5 or more individuals of a rare or solitary species.

(E) Involves effects to, or illegal pesticide treatment ( misuse) of a substantial tract of habitat (greater than or equal to 10 acres, terrestrial or aquatic).

Plants :

(A) The effect is alleged to have occurred on more than 45 percent of the acreage exposed to the pesticide.

All other ecological incidents are considered ‘minor’ and only need to be aggregately reported. ‘Minor’ incidents reported by the registrants are not included in the EIIS database. Therefore, for example, an incident could affect 900 fish, 150 birds, 45 mammals, and 40% of an exposed

cro p and not be included in the EIIS database [unless is it reported by a non

- registrant ( e.g ., an incident submitted by a state agency

– which are not systematically collected)]. Therefore,
because the number of documented kills in EIIS is believed to be a small fraction of total mortality caused by pesticides, absence of reports does not necessarily provide evidence of an
absence of incidents.

### 59 

# APPENDIX 4 . SIP v.1.0 Inputs and Outputs

SIP employs the following conservative assumptions to derive upper bound exposure
estimates: 1) The chemical concentration in drinking water is at the solubility limit in water (at 25 o 

### C). 2) The assessed animals obtain 100% of their daily water needs through drinking water. 3) The daily water need is equivalent to the daily water flux rate as calculated by Nagy and Peterson (1988). 4) The body weight of the assessed bird is equivalent to the smallest generic bird modeled
in T

- REX (i.e., 20 g). This assumption results in the highest ratio of exposure to toxicity for
the 3 assessed avian body weights of T

- REX (i.e., 20, 100, 1000 g). 5) The body weight of the assessed mammal is equivalent to the largest generic mammal
modeled in T

- REX (i.e., 1000 g). This results in the highest ratio of exposure to toxicity for the 3 assessed mammalian body weights of T

- REX (i.e., 15, 35, 1000 g).

Table 1. Inputs

Parameter Value Data source

Chemical name Sulfometuron methyl
Solubility (in water at 25 o C; mg/L) 244 2008 RED; USEPA, 2008

Mammalian LD 50 (mg/kg

- bw) 5000 MRID 43089201 Mammalian test species laboratory rat Body weight (g) of "other" mammalian species

Mammalian NOAEL (mg/kg

- bw) 300 MRID 00078798 Mammalian test species other Body weight (g) of "other" mammalian species 3898

Avian LD 50 (mg/kg

- bw) 4650 MRID 00078700 Avian test species mallard duck Body weight (g) of "other" avian species Mineau scaling factor 1.15

Mallard NOAEC (mg/kg

- diet) 500 For flazasulfuron, MRID 46220926 Bobwhite quail NOAEC (mg/kg

- diet) 484 For primisulfuron, MRID 40512004 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

Enter body weight of 'other' mammalian species for NOAEL.

### 60 Table 2. Mammalian Results

Parameter Acute Chronic Upper bound exposure (mg/kg

- bw) 41.9680 41.9680 Adjusted toxicity value (mg/kg

- bw) 3845.8028 421.5331 Ratio of exposure to toxicity 0.0109 0.0996

Conclusion* Drinking water exposure alone is NOT a potential

concern for mammals Drinking water exposure alone is NOT a potential

concern for mammals

Table 3. Avian Results

Parameter Acute Chronic Upper bound exposure (mg/kg

- bw) 197.6400 197.6400 Adjusted toxicity value (mg/kg

- bw) 2414.3981 24.8063

Ratio of exposure to acute toxicity 0.0819 7.9673

Conclusion* Drinking water exposure alone is NOT 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.

### 61 

# APPENDIX 5 . STIR v.1.0 Inpu ts and Outputs

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 Data Source Application and Chemical Information
Enter Chemical Name Sulfometuron methyl

Enter Chemical Use non

- crop 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) 364.38 2008 RED, USEPA Enter Chemical Vapor Pressure (mmHg) 5.40E

- 16 2008 RED, USEPA Enter Application Rate (lb a.i./acre) 0.375 2008 RED, USEPA Toxicity Properties
**Bird**

Enter Lowest Bird Oral LD 50 (mg/kg bw) 4650 MRID 00078700 Enter Mineau Scaling Factor 1.15 Enter Tested Bird Weight (kg) 1.58

**Mammal**

Enter Lowest Rat Oral LD 50 (mg/kg bw) 5000 MRID 43089201

Enter Lowest Rat Inhalation LC 50 (mg/L) 5 MRID 43089203 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/m 3 ) 1.06E

- 11

Maximum 1

- hour Vapor Inhalation Dose (mg/kg) 1.33E

- 12

Adjusted Inhalation LD 50 1.87E+01

Ratio of Vapor Dose to Adjusted Inhalation LD 50 7.12E

- 14 Exposure not Likely Significant
Maximum Post

- treatment Spray Inhalation Dose (mg/kg) 3.60E

- 02 Ratio of Droplet Inhalation Dose to Adjusted Inhalation
LD 50 1.93E

- 03 Exposure not Likely Significant

Results Mammalian (0.015 kg ) Maximum Vapor Concentration in Air at Saturation (mg/m 3 ) 1.06E

- 11

Maximum 1

- hour Vapor Inhalation Dose (mg/kg) 1.67E

- 12

Adjusted Inhalation LD 50 2.98E+02

Ratio of Vapor Dose to Adjusted Inhalation LD 50 5.62E

- 15 Exposure not Likely Significant
Maximum Post

- treatment Spray Inhalation Dose (mg/kg) 4.53E

- 02 Ratio of Droplet Inhalation Dose to Adjusted Inhalation
LD 50 1.52E

- 04 Exposure not Likely Significant

### 62 

# APPENDIX 6 . The Risk Quotient Method and Levels of Concern

The Risk Quotient Method is the means used by EFED to integrate the results of exposure and ecotoxicity data. For this method, Risk Quotients (RQs) are calculated by dividing exposure estimates by the acute and chronic ecotoxicity values (i.e., RQ = EXPOSU RE/TOXICITY). These RQs are then compared to OPP's levels of concern (LOCs). These LOCs are criteria used by OPP to indicate potential risk to non

- target organisms and the need to consider regulatory action. EFED has defined LOCs for acute risk, potential restricted use classification, and for endangered species.

The criteria indicate that a pesticide used as directed has the potential to cause adverse effects

on non

- target organisms. LOCs currently address the following risk presumption categories:

(1) a cute

- there is a potential for acute risk; regulatory action may be warranted in addition to restricted use classification;

(2) acute restricted use

- the potential for acute risk is high, but this may be mitigated through restricted use classification;

(3) acute endangered species

- the potential for acute risk to endangered species is high, regulatory action may be warranted; and

(4) chronic risk

- the potential for chronic risk is high, regulatory action may be warranted.

Currently, EFED does not perform assessments for chronic risk to plants, acute or chronic
risks to non

- target insects, or chronic risk from granular/bait formulations to mammalian or avian species.

The ecotoxicity test values (i.e., measurement endpoints) used in the acute and chronic RQs are derived from required studies. Examples of ecotoxicity values derived from short

- term laboratory studies that assess acute effects are: (1) LC50 (fish and birds), (2) LD50 (birds and mammals), (3) EC50 (aquatic plants and aquatic invertebrates), and (4) EC25 (terrestrial plants). Examples of toxicity test effect levels derived from the results of long

- term laboratory studies that assess chronic effects are: (1) the Lowest Observed Adverse Effect Concentration (LOAEC) ( birds, fish, and aquatic invertebrates), and (2) the No Observed Adverse Effect Concentration (NOAEC) (birds, fish and aquatic invertebrates). The NOAEC is generally used as the ecotoxicity test value in assessing chronic effects. Risk presumptions, along with the corresponding RQs and LOCs are summarized in Table B1

.

### 63 Table B1. Agency risk quotient (RQ) metrics and levels of concern (LOC) per risk class.

Risk Class Risk Description RQ LOC

Aquatic Animals (fish and invertebrates)

Acute Potential for effects to non

- listed animals from acute

exposures Peak EEC/LC 50 1 0.5

Acute
Restricted Use Potential for effects to animals from acute exposures

Risks may be mitigated through restricted use
classification Peak EEC/LC 50 1 0.1

Acute Listed Species Listed species may be potentially affected by acute

exposures Peak EEC/LC 50 1 0.05

Chronic Potential for effects to non

- listed and listed animals from chronic exposures 60

- day EEC/NOEC (fish) 1

21

- day EEC/NOEC (invertebrates)

Terrestrial Animals (mammals and birds)

Acute Potential for effects to non

- listed animals from acute

exposures EEC 2 /LC 50 (Dietary) 0.5

EEC/LD 50 (Dose)

Acute
Restricted Use Potential for effects to animals from acute exposures

Risks may be mitigated through restricted use classification EEC 2 /LC 50 (Dietary) 0.2

EEC/LD 50 (Dose)

Acute Listed Species Listed species may be potentially affected by acute

exposures EEC 2 /LC 50 (Dietary) 0.1

EEC/LD 50 (Dose)

Chronic Potential for effects to non

- listed and listed animals from chronic exposures EEC 2 /NOAEC 1

Plants

Non

- Listed Potential for effects to non

- target, non

- listed plants from exposures EEC/ EC 25 1

Listed Plant Potential for effects to non

- target, listed plants from

exposures EEC/ NOEC 1

EEC/ EC 05

1 LC 50 or EC 50
. 2 Based on upper bound Kenaga values.

### 64 

# APPENDIX 7

. Toxicity Endpoints for Sulfometuron Methyl and its Degradates and Analogues

Detailed summaries of measured and modeled endpoints for sulfometuron methyl and its degradates and related compounds are presented in T ables 10 to 13

.

Table 10

. Summary of Toxicity Endpoints for Saccharin

Taxonomic Group Study Type Species Toxicity Value & Acute Toxicity Classification Source

Freshwater
f ish Acute Rainbow t rout ( Oncorhynchus mykiss ) 96

- hr LC 50 > 124 mg /L Practically non

- toxic MRID 48518912
In review

Chronic N/A Chronic value* = 2.4 mg/L ECOSAR: Class amides

Freshwater
invertebrates Acute Water flea ( Daphnia magna ) 48

- hr EC 50 > 118 mg/L Practically non

- toxic MRID 48518911
In review

Chronic N/A Chronic value* = 1.7 mg/L ECOSAR: Class amides

Aquatic plants Vascular Duckweed ( Lemna gibba ) 14

- day EC 50 = 5.5 mg/L
14

- day NOEC < 0.63 mg/L MRIDs 48518909 and 45791505
In review

Non

vascular Green alga ( Selenastrum capricornutum ) 72

- hr EC 50 > 10 mg/L MRID 48518910
In review

Green algae Chronic value* = 3.4 mg/L ECOSAR: Class thiazolinones (iso

- )

Mammals Acute
oral Rat LD 50 > 142,000 mg/kg

- bw Practically non

- toxic PPBD data 1

* duration associated with the reported chronic value was not reported by the ECOSAR program

1 T oxicity data were retrieve d from PPDB through a search using the CAS number for saccharin, 81

- 07

- 2 . The Pesticide Properties Database (aka. Footprint) may be accessed at : http://sitem.herts.ac.uk/aeru/footprint/en/index.htm



### Table 11

. ECOSAR

- predicted Toxicity Values for Four Major Degradates of Sulfometuron Methyl

. Degradate Name ECOSAR Class Organism Toxicity Endpoint Degradate Toxicity
Value (mg/L) 24 Parent
EEC (mg/L)

pyrimidine amine

( 2

- Pyrimidinamine, 4,6

- dimethyl ) Anilines

– aromatic amines Fish 1 96

- hr LC 50 Chronic value 61
0.29 0.0315
0.0205 Neutral organics Daphnid 1 48

- hr LC 50 Chronic Value** 700
27 0.0315
0.0205 Green Algae 1 96

- hr EC50
Chronic value** 101
30 0.0315
0.0205

24 When possible, the ECOSAR class that best predicts the toxicity for each degradate/taxon combination was chosen by comparing laboratory toxicity data and ECOSAR

- predicted toxicity values for related degradates of registered sul fonylurea herbicides.

### 65 Degradate Name ECOSAR Class Organism Toxicity Endpoint Degradate Toxicity
Value (mg/L) 24 Parent
EEC (mg/L)

pyrimidine

- ol

( 2

- Hydroxy, 4,6

- dimethyl pyrimidine ) Phenols Freshwater f ish 96

- h r LC 50 30

- day Chronic
value*** 60
3.6 0.0315
0.0262

Daphnid 48

- h r LC 50 21

- d ay Chronic

v alue 16
3. 1 0.0315
0.0262

Green a lgae 96

- h r EC 50 Chronic value** 79
3 8 0.0315
0.0205 Lemna gibba 7

- day EC 50 6 2 0.0315

Saltwater fish 96

- hr LC 50 67 0.0315

Sulfonamide

( 2

- (Aminosulfonyl) benzoic acid, methyl ester ) Esters Freshwater f ish 96

- h r LC 50 32/33

- day Chronic

v alue 15 1
18 0.0315
0.0262

Daphnid 48

- h r LC 50 21

- day Chronic

v alue 36 4
316 0.0315
0.0262

Mysid shrimp 96

- hr LC 50 Chronic value** 41 9
4. 3 x10 5 * 0.0315
0.0205

Saltwater fish 96

- hr LC 50 Chronic value** 256
30 + 0.0315
0.0205

Amides Freshwater f ish 96

- h r LC 50 Chronic value** 26 8
1. 6 0.0315
0.0205 Daphnid 48

- h r LC 50 Chronic v alue ** 98
1. 3 0.0315
0.0205 Green algae 2 96

- hr EC 50 Chronic value** 1.1
0.36 0.0315
0.0205

free acid sulfonamide

2

- (Aminosulfonyl) benzoic acid Amides

- acid Fish 96

- hr LC 50 Chronic value** 11669*
69 0.0315
0.0205 Daphnid 48

- hr LC 50 Chronic value** 3192*
42 + 0.0315
0.0205 Green algae 2 96

- hr EC 50 Chronic value** 17
3.4 0.0315
0.0205

1 ECOSAR class w as chosen by comparing laboratory toxicity data and ECOSAR

- predicted toxicity values for

related degradate of dimethoxy a minopyrimidine (see Table 12 ).

2 ECOSAR class (amides) was chosen by comparing laboratory toxicity data and ECOSAR

- predicted toxicity

values for related degradate of IND1R84. * predicted toxicity value may exceed compou nd’s aqueous solubility ** duration associated with the reported chronic value was not reported by the ECOSAR program
*** 60

- day chronic value of 0.004 mg/L was deemed unreliable based on the paucity of underlying data used to generate the
value
+ The t oxicity value was determined from a predicted SAR using established ACR ratios and ECOSAR regression techniques.



### Table 12

. Toxicity Data and QSAR Analysis for Dimethoxy Aminopyrimidine (CP 17477)
Endpoint CP 17477 (PPDB data 1 ) CP 17477 (ECOSAR

– aromatic amine SAR) CP 17477 (ECOSAR

– neutral organic SAR)
Fish 96

- h LC 50 97 mg/L (rainbow trout) 79 mg/L 920 mg/L

### 66 Fish chronic toxicity value 2 No data 0.38 mg/L 90 mg/L Algae 96h EC 50 120 mg/L ( P. subcapitata ) 9.2 mg/L 130 mg/L

Lemna 7

- d EC 50 >100 mg/L No prediction No prediction Daphnid 48

- h EC 50 >100 mg/L 2.4 mg/L 469 mg/L Daphnid chronic toxicity value 2 24 mg/L (21

- d NOEC) 0.05 mg/L 36 mg/L

1 Other company chemical codes for this metabolite include INJV0290, AE

- F092944, and HOE092944. Aquatic toxicity data were retrieved from PPDB through a search for the string “2

- amino

- 4,6

- dimethoxypyrimidine” or for

“AE

- F092944” (duplicate entries for this compound in the database may not contain this information). The Pesticide Properties Database (aka. Footprint) may be accessed at: http://sitem.herts.ac.uk/aeru/footprint/en/index.htm

2 ChV = ECOSAR chronic toxicity value



## Degradate toxicity in compari son to parent toxicity

Also important to the analysis of degradate toxicity is the comparative data for parent compound

– both measured and ECOSAR predictions for parent are summarized and compared to EECs in
Table 6 and provided in more detail in Table 13

. ECOSAR

- predicted toxicities for sulfometuron methyl are based on returned results for toxicity endpoints for three ECOSAR classes: esters, amides, and sulfonylureas. Collectively, ECOSAR predicted the toxicity of sulfonylureas to be slightly toxic to practically non

- toxic to fish, daphnids, and mysid shrimp on
an acute exposure basis

– similar to the level of toxicity for sulfometuron methyl degradates discussed above. Also, this is similar to observed data from registrant

- submitted studies (also provided in Table 13 ). The predicted toxicity of each of the degradates to non

- vascular plants / algae was much lower ( Table 10 and Tab le 11 ) than parent toxicity supporting a conclusion that the primary effects on plants from sulfometuron methyl application likely come from exposure to the parent molecule.

Table 13

. ECOSAR

- predicted and Observed Toxicity Values for Parent Sulfometuron Methyl Organism Toxicity Endpoint Toxicity Value (mg/L) Registrant

submitted data 1 ECOSAR class

Esters Amides Sulfonylu reas Freshwater
f ish 96

- h r LC 50 Chronic v alue >148
No data 72
6.9 79
0.47 No predictions

Daphnid 48

- h r LC 50 Chronic v alue >150
97 154
105 40
0.53 + 134
12 +

Green a lgae 96

- or 120

- h r EC 50 Chronic value 0.0046
No data 68
16 0.96
0.61 0.04
0.01 + Mysid shrimp 96

- hr LC 50 Chronic value > 44.8
No data 121
16516* No predictions No predictions

Saltwater
fish 96

- hr LC 50 Chronic value >45
No data 111
15 + No predictions No predictions

* predicted toxicity value may exceed compound’s aqueous solubility + The toxicity value was determined from a predicted SAR using established ACR ratios and ECOSAR regression techniques.

1 from Table 4

### 67 

## Comparisons to measured toxicity values for related pesticide degradates

Many sulfonylurea herbicides have similar degradates to each other (where sulfometuron methyl relates structurally to many other sulfonylurea herbicides with similar degradates is summarized in Section 3.2 above. In this section we provide some context to the sulfometuron degradate toxicological analysis for the pyrimidine amine degradate by an analysis of the availab le toxicity data for a similar degradate produced by several other sulfonylurea herbicides.

Confidence in the ability of ECOSAR to predict the toxicity of degradates of sulfometuron methyl was assessed by comparing observed endpoint values from laborator y studies with
ECOSAR

- predicted values for dimethoxy aminopyrimidine (CP17477), a pyrimidine degradate of a number of sulfonylurea herbicides that is structurally similar to the pyrimidine amine ( 4,6

- dimethyl

- 2

- pyrimidinamine) degradate of sulfometuron met hyl.

Results for dimethoxy aminopyrimidine (a degradation product of many registered sulfonylurea herbicides which is predicted to have a similar toxicological profile to the dimethyl aminopyrimidine formed from the degradation of sulfometuron methyl) wer e previously discussed in the halosulfuron methyl Problem Formulation ( DP Barcode: D394807 ; 3/8/2012 ), including both direct test data and QSAR results from ECOSAR. Table 12 shows the observed
values record ed in the Pesticide Properties Datab ase (PPDB) maintained by the FOOTPRINT Project 25 

### and predicted toxicity using either neutral organic or aromatic amine structure

- activity relationships in ECOSAR

. Based on the data available in the PPDB database, the measured values are within the range of the predicted values by ECOSAR . The aromatic amine ECOSAR class best predicts toxicity to freshwater fish, and the neutral organic ECOSAR class best predicts tox icity to algae and daphnia. This analysis suggests that ECOSAR may serve as a reliable predictor of toxicity values for the pyridimine amine degradates of sulfonylureas.

25 More information accessible at: http://sitem.herts.ac.uk/aeru/footprint/

.