**UNITED STATES ENVIRONMENTAL PROTECTION
AGENCY**![](media/image1.png){width="0.9965277777777778in"
height="0.8097222222222222in"}

WASHINGTON, D.C. 20460

OFFICE OF

PREVENTION, PESTICIDES

AND TOXIC SUBSTANCES

December 20, 2007

**[MEMORANDUM]{.underline}**

SUBJECT: **Sulfometuron Methyl**: HED Chapter of the Reregistration
Eligibility Decision Document (RED). PC Code: 122001, DP Barcode:
346064.

Regulatory Action: Phase 1 Reregistration Action

Risk Assessment Type: Single Chemical, Non-Food

FROM: Wade Britton, MPH, Risk Assessor

> Reregistration Branch 3
>
> and
>
> Larry Chitlik, Ph.D., Toxicologist
>
> Reregistration Branch 1

Health Effects Division (7509P)

THROUGH: Paula Deschamp, RARC Designated Reviewer

> Richard Loranger Ph.D., RARC Designated Reviewer

And

Catherine Eiden, Branch Chief

> Danette Drew, Chemist

Reregistration Branch 3

and

Michael Metzger, Branch Chief

> Registration Branch 1
>
> Health Effects Division (7509P)

TO: Russell Wasem, Chemical Review Manager

Reregistration Branch 1

Special Review & Reregistration Division (7508P)

Attached is the Health Effect Division's preliminary risk assessment for
the sulfometuron methyl RED. This risk assessment document was based on
information contained in the following memos:

Occupational and Residential Exposure Assessment: W. Britton, D345025,
12/18/07

Water Memo: M. Barrett Ph.D., D334287, 10/31/07

DEEM Memo: W. Britton, D346139, 12/18/07

Incident Report: R. Allen Ph.D., M. Hawkins & H. Allender Ph.D., D343943

**Table of Contents**

[1.0 Executive Summary 4](#__RefHeading___Toc185681376)

[2.0 Ingredient Profile 7](#__RefHeading___Toc185681377)

[2.1 Structure and Nomenclature 8](#__RefHeading___Toc185681378)

[3.0 Hazard Characterization/Assessment 9](#__RefHeading___Toc185681379)

[**3.1** **Hazard and Dose-Response Characterization**
9](#__RefHeading___Toc185681380)

[**3.1.1** **Database Summary** 9](#__RefHeading___Toc185681381)

[**3.1.1.1** **Sufficiency of studies/data**
10](#__RefHeading___Toc185681382)

[**3.1.1.2** **Mode of Action, Metabolism, Toxicokinetic Data**
10](#__RefHeading___Toc185681383)

[**3.2** **Absorption, Distribution, Metabolism, Excretion (ADME)**
10](#__RefHeading___Toc185681384)

[**3.3** **Hazard Identification and Toxicity Endpoint Selection**
10](#__RefHeading___Toc185681385)

[**3.3.1 Acute Reference Dose (aRfD) -- All Population Subgroups**
10](#__RefHeading___Toc185681386)

[**3.3.2** **Chronic Reference Dose (cRfD)**
11](#__RefHeading___Toc185681387)

[**3.3.3** **Dermal Absorption** 11](#__RefHeading___Toc185681388)

[**3.3.4** **Dermal Exposure (Short-, Intermediate- and Long-Term)**
11](#__RefHeading___Toc185681389)

[**3.3.5** **Inhalation Exposure (Short- and Intermediate -Term)**
12](#__RefHeading___Toc185681390)

[**3.3.6** **Level of Concern for Margin of Exposure**
13](#__RefHeading___Toc185681391)

[**3.3.7** **Classification of Carcinogenic Potential**
13](#__RefHeading___Toc185681392)

[**3.3.8** **Summary of Toxicological Doses and Endpoints for
Sulfometuron Methyl** 13](#__RefHeading___Toc185681393)

[**3.4** **Endocrine Disruption** 14](#__RefHeading___Toc185681394)

[4.0 Public Health and Pesticide Epidemiology Data
14](#__RefHeading___Toc185681395)

[5.0 Dietary Exposure/Risk Characterization
14](#__RefHeading___Toc185681396)

[**5.1** **Pesticide Metabolism and Environmental Degradation**
14](#__RefHeading___Toc185681397)

[**5.2 Dietary Exposure Estimates** 16](#__RefHeading___Toc185681398)

[6.0 Residential (Non-Occupational) Exposure/Risk
19](#__RefHeading___Toc185681399)

[**6.1** **Other (Spray Drift, etc.)** 19](#__RefHeading___Toc185681400)

[7.0 Aggregate Risk Assessments and Risk Characterization
19](#__RefHeading___Toc185681401)

[8.0 Occupational Exposure/Risk Pathway
19](#__RefHeading___Toc185681402)

[**8.1 Sulfometuron Methyl Occupational Handler Exposure Scenarios**
20](#__RefHeading___Toc185681403)

[**8.1.1** **Data and Assumptions for Handler Exposure Scenarios**
21](#__RefHeading___Toc185681404)

[**8.1.2** **Occupational Handler Exposure/Risk Estimates**
22](#__RefHeading___Toc185681405)

[**8.1.3** **Risk Characterization** 24](#__RefHeading___Toc185681406)

[9.0 Data Needs and Label Recommendations
25](#__RefHeading___Toc185681407)

[Appendix A: Toxicology Assessment 26](#__RefHeading___Toc185681408)

[Appendix B: EPA Review of Human Research - Studies Reviewed for Ethical
Conduct 37](#__RefHeading___Toc185681409)

[]{#__RefHeading___Toc185681376 .anchor}**1.0 Executive Summary**

This assessment provides information to support the issuance of a risk
management decision document known as a Reregistration Eligibility
Decision (RED) Document for sulfometuron methyl. EPA's pesticide
reregistration process provides for the review of older pesticides
(those initially registered prior to November 1984) under the Federal
Insecticide, Fungicide, and Rodenticide Act (FIFRA) to ensure that they
meet current scientific and regulatory standards.

Sulfometuron methyl is a non-food/non-feed use chemical with no current
or proposed usages which could lead to exposures from consuming raw
agricultural commodities and/or processed foods. As a result, no
tolerance levels have been established for this chemical and the
requirements of the Food Quality Protection Act (FQPA) do not apply.
Nevertheless, the present document considers all relevant exposure
scenarios to sulfometuron methyl in order to provide an evaluation of
the risks to human health arising from its supported uses. All drinking
water and all but one occupational exposure scenarios evaluated were
found to have risk levels below HED's level of concern.

Sulfometuron methyl is a nonselective, sulfonyl urea herbicide. It is
labeled for commercial pre- and post-emergent applications to manage
annual and perennial broadleaf weeds and grasses in non-agricultural
sites (i.e., forestry, rights of way, non-crop industrial sites, and
unimproved turf). Sulfometuron methyl acts by inhibiting acetolactate
synthase (ALS), an enzyme that catalyzes the biosynthesis of three
branched-chain amino acids (valine, leucine, and isoleucine), all of
which are essential for plant growth. Control is generally for a full
season or longer with only one required application per year; however,
in some situations (i.e., weed escapes) a second application may be
made, but the total applied annually should not exceed the maximum
application rate. []{.mark}

[]{.mark}

According to the OPPIN Database, there are currently a total of 24
registered sulfometuron methyl products, of which 4 are technical or
manufacturing concentrate formulations. All registered sulfometuron
methyl products are formulated as water dispersable granules (WDGs),
ranging from 18 to 75% ai. Applications range from 0.03 to 0.38 pound of
active ingredient (ai) per acre and are directed via liquid spray using
ground or aerial equipment. Based upon the 11/28/2006 sulfometuron
methyl SMART meeting, there are no registered uses for sites which could
be considered residential or recreational settings. While labeled use
sites of sulfometuron methyl include turf (unimproved) and non-crop
industrial, label language prohibits application to these sites in
residential and recreational areas.

**Hazard Characterization**

Though the toxicological database for sulfometuron methyl is limited, it
is considered to provide sufficient information to conduct a screening
level risk assessment for the current use patterns. In order to refine
the current risk estimates, additional toxicity studies would be
required. In general, the data available indicate a low level of
toxicity. The primary toxic effect of this sulfonyl urea pesticide is
hemolytic anemia, which represents the most sensitive toxic endpoint for
risk assessment. Sulfometuron methyl is not acutely toxic via the oral,
dermal, or inhalation routes of exposure. It shows minimal eye
irritation and minimal skin irritation, but is not a dermal irritant or
a dermal sensitizer.

[]{.mark}

A toxicity endpoint has been selected to assess potential risks
resulting from drinking water and occupational exposure to sulfometuron
methyl. An acute reference dose (aRfD), chronic reference dose (cRfD),
and points of departure for dermal and inhalation toxicity were selected
from a chronic dog feeding study. The endpoint for the acute reference
dose selected from the chronic toxicity study provides a very
conservative point of departure for acute risk assessment. In the
absence of fully acceptable guideline studies which might yield a
different acute endpoint (e.g., acceptable developmental toxicity
studies), and considering the limited findings in the available
developmental studies, use of the chronic dog endpoint will be
protective.

The 21-day dermal rabbit study was determined to be insufficient to
assess dermal exposures due to a number of deficiencies in the study. No
route specific study was available for inhalation toxicity; therefore,
an inhalation endpoint was selected based upon the chronic oral toxicity
study. With chronic oral exposure, signs of hemolytic anemia were
observed in dogs and body weight effects were seen beginning on the
fourth week (and persisting throughout the entire study) of repeated
exposure. Although no hematological or clinical chemistry assessments
are available at the 4-week interval, the decreases in body weight gain
noted beginning on the fourth week of the study provide an appropriate
endpoint for short-term risk assessment. Since the hematological effects
noted at the end of the study occurred at the same dose level as the
body weight gain decrements seen beginning on the fourth week of
exposure, this study and endpoints are also appropriate to assess
potential intermediate- and long-term risks due to sulfometuron methyl
exposure.

[]{.mark}

Carcinogenicity studies on sulfometuron methyl were not required since
it is a non-food/non-feed pesticide and chronic exposure to this
pesticide is not expected based on the use pattern. It was negative in
the mutagenicity/genetic toxicity studies.

**Dietary Exposure**

Since sulfometuron methyl is a non-food/non-feed chemical, any potential
dietary exposure arises from drinking water sources. It is mobile and
persistent in the environment and it dissipates via aerobic and
anaerobic degradation/ metabolism in soil and water (pseudo first-order
degradation half-lives generally around 2 to 6 months), with hydrolysis
potentially dominant under acidic conditions. Sulfometuron methyl's
persistence in water indicates that if it reaches the surface water, it
may persist for a few weeks to several months. The fairly low use rate
and the apparent typical use pattern of applying in only one or two
years out of a several year period should limit the actual exposure to
sulfometuron methyl residues in surface water based drinking water,
specifically over the chronic duration. While recognized as
conservative, the potential exists for exposure from drinking water
sources (surface and ground) and, therefore, an assessment was completed
for acute and chronic exposure durations.

Conservative acute and chronic screening-level drinking water
assessments were made with DEEM-FCID™, based upon the Environmental Fate
and Effects Division's (EFED) determination of Estimated Drinking Water
Concentrations (EDWCs) for exposure (M. Barrett, D334287). The results
indicate that exposures to sulfometuron methyl are below HED's level of
concern. The analysis uses a survey-based consumption distribution
together with an upper-bound residue value for drinking water. The acute
and chronic drinking water exposure to sulfometuron methyl is estimated
to be \< 1 % of the RfDs for the general U.S. population. For the most
highly exposed subgroup, all infants (\< 1 year old), estimated acute
dietary exposure is 2.3 % of the aRfD and chronic dietary exposure is \<
1 % of the cRfD. Therefore, HED is not concerned that the
non-food/non-feed use of sulfometuron methyl could result in
unacceptable risk from potential exposure through drinking water
sources.

**Residential Handler and Postapplication Exposure/Risk**

Residential exposure/risk (handler and postapplication) was not assessed
since label instructions do not allow applications of sulfometuron
methyl to residential or recreational settings.

**Aggregate Risk**

An aggregate exposure assessment, which combines exposures from
different sources and routes, is typically conducted for non-food/
non-feed chemicals when there is potential for human exposure through
water and residential pathways. Since sulfometuron methyl has no
residential uses, the only source of exposure is from drinking water;
therefore, an aggregate exposure assessment was not performed.

**Occupational Handler Exposure/Risk**

Sulfometuron methyl products are registered for use in the occupational
environment to manage annual and perennial broadleaf weeds and grasses
in a variety of sites (i.e., forestry, non-crop industrial, unimproved
turf, and non-crop habitat restoration). As a result, occupational
handlers of sulfometuron methyl could potentially be exposed during the
application process.

Short- (up to 30 days) and intermediate-term (30 days to 6 months)
dermal and inhalation exposure/risk was calculated for occupational
handlers of sulfometuron methyl for different exposure scenarios.
Long-term handler exposures (greater than 6 months) are not expected to
occur. All but one of the occupational handler short- and
intermediate-term scenarios assessed (dermal and inhalation combined)
resulted in risk estimates (MOEs) ≥ 100 at some level of personal
protection and, therefore, are not of concern. The exposure scenario
mixing/loading WDGs for aerial application to forestry and non-crop
areas results in a combined MOE = 90 at the maximum level of personal
protection (double layer with gloves) and, therefore, is of potential
concern. However, this concern is significantly reduced because of the
use of conservative inputs in the risk estimates (e.g., 100% dermal
absorption).

An occupational postapplication assessment of exposure to sulfometuron
methyl was not performed. Since sulfometuron methyl is a non-selective
herbicide used in non-agricultural areas, HED has determined that
contact with previously treated areas is likely to be insignificant.

**Environmental Justice Considerations**

Potential areas of environmental justice concerns, to the extent
possible, were considered in this human health risk assessment, in
accordance with U.S. Executive Order 12898, \"Federal Actions to Address
Environmental Justice in Minority Populations and Low-Income
Populations,\"
<http://www.eh.doe.gov/oepa/guidance/justice/eo12898.pdf>).

As a part of every pesticide risk assessment, OPP considers a large
variety of consumer subgroups according to well-established procedures.
In line with OPP policy, HED estimates risks to population subgroups
from pesticide exposures that are based on patterns of that subgroup's
food and water consumption, and activities in and around the home that
involve pesticide use in a residential setting. Whenever appropriate,
non-dietary exposures based on home use of pesticide products and
associated risks for adult applicators and for toddlers, youths, and
adults entering or playing on treated areas postapplication are
evaluated. Further considerations are currently in development, as OPP
has committed resources and expertise to the development of specialized
software and models that consider exposure to bystanders and farm
workers as well as lifestyle and traditional dietary patterns among
specific subgroups.

**Review of Human Research**

This risk assessment relies in part on data from studies in which adult
human subjects were intentionally exposed to a pesticide or other
chemical. These studies (listed in Appendix B) have been determined to
require a review of their ethical conduct, have received that review and
have been determined to be ethical.

**Additional Data Needs**

No additional data are needed to support the human health assessment of
sulfometuron methyl.

[]{#__RefHeading___Toc185681377 .anchor}**2.0 Ingredient Profile**

Sulfometuron methyl is a non-selective, sulfonyl urea herbicide labeled
for commercial pre- and post-emergent applications to manage annual and
perennial broadleaf weeds and grasses.

**Summary of Use Patterns, Formulations and Application Methods**

All sulfometuron methyl products are formulated as WDG (ranging from 18
to 75% ai) and are directed to the target via liquid spray applications
via aerial or ground application methods. Registered uses of
sulfometuron methyl include:

-   forestry (conifers, hardwoods, hybrid poplar plantations);

-   non-crop industrial sites (public, private, and military lands,
    rights-of-way, under asphalt and concrete);

-   turf (unimproved); and

-   non-crop habitat restoration sites.

**Application Rates, Timing and Frequency of Applications**

Application rates of sulfometuron methyl range from 0.03 to 0.38 pound
of active ingredient (ai) per acre. Control is generally for a full
season or longer with only one application per year; however, in some
situations (i.e., weed escapes) a second application may be made, but
the total applied annually should not exceed the maximum application
rate.

**Application Methods**

Applications of sulfometuron methyl can be made aerially (helicopter and
fixed-wing airplane) or by ground (high and low pressure handwand,
groundboom, and rights-of-way sprayer). Low pressure handwand
applications are typical for selective foliar applications (applied to
target vegetation), while aerial, groundboom, and rights-of-way
applications are specific to wide-area, broadcast treatments.

[]{#__RefHeading___Toc185681378 .anchor}**2.1 Structure and
Nomenclature**

  ---------------------------------------------------------------------------------------------------------
  **Table 2.1.a. Test    
  Compound Nomenclature  
  -- Sulfometuron        
  Methyl**               
  ---------------------- ----------------------------------------------------------------------------------
  Chemical Structure     ![](media/image2.jpeg){width="2.9368055555555554in" height="1.2395833333333333in"}

  Empirical Formula      C~15~H~16~N~4~O~5~S

  Common Name            Sulfometuron Methyl

  IUPAC name             methyl 2-(4,6-dimethylpyrimidin-2-ylcarbamoylsulfamoyl)benzoate

  CAS Name               methyl
                         2-\[\[\[\[(4,6-dimethyl-2-pyrimidinyl)amino\]carbonyl\]amino\]sulfonyl\]benzoate

  CAS Registry Number    74222-97-2

  Chemical Class         Pyrimidinylsulfonylurea Herbicides
  ---------------------------------------------------------------------------------------------------------

  -----------------------------------------------------------------------
  **Table 2.1.b.                             
  Physiochemical                             
  Properties**                               
  ---------------------- ------------------- ----------------------------
  **Parameter**          **Value**           **Reference**

  Molecular Weight       364.4               The Pesticide Manual: A
                                             World Compendium, 9^th^ ed.,
                                             1991, C.R. Worthington, ed.
                                             The British Crop Protection
                                             Council, Surrey, UK pg. 774

  Melting point          203-205°C           

  Physical state         Colorless Solid     

  Vapor pressure (25°C)  6.0 x 10^-5^ mm Hg  

  Water solubility       70 ppm              
  (25°C)                                     

  Log Kow (25°C)         1.2                 
  -----------------------------------------------------------------------

[]{#__RefHeading___Toc185681379 .anchor}**3.0 Hazard
Characterization/Assessment**

The toxicology database for sulfometuron methyl is limited, but
sufficient to provide screening level endpoints for this
non-food/non-feed pesticide. Since risks are generally not of concern
based on this screen, additional data will not be required at this time.
However, if significant additional uses are requested, additional
toxicity data will be required.

Sulfometuron methyl is not acutely toxic. The acute oral LD~50~ in rats
is \> 5 g/kg (Toxicity Category IV), the acute dermal LD~50~ is \> 2
g/kg (Toxicity Category III), and the acute inhalation LC~50~ \> 5.0
mg/L (Toxicity Category IV). Sulfometuron methyl shows minimal eye
irritation and minimal skin irritation, but is not considered a dermal
irritant or dermal sensitizer.

[]{.mark}

The primary toxic effect of this sulfonyl urea pesticide is hemolytic
anemia (the most sensitive toxic endpoint) reported in the chronic oral
toxicity study in dogs. This observation is consistent with reports in
the open literature where hemolytic anemia has been identified as a side
effect of sulfonyl urea compounds (e.g., chlorpropamide, LY186641) used
therapeutically as anti-diabetic or anti-tumor agents^1^. In addition to
hemolytic anemia, decreases in body weight were also seen in the chronic
oral toxicity study beginning on the fourth week of exposure and
persisting throughout the duration of the study.

Other studies available in the database include a dermal toxicity study
as well as pre-natal developmental toxicity studies (in rats and
rabbits). Due to a number of deficiencies identified in the conduct of
these studies, they were not deemed suitable for endpoint selection in
the risk assessment. Nonetheless, based on the information provided
within these studies, the Agency is confident that the use of the
chronic oral toxicity study in dogs would result in a health protective,
albeit conservative, risk assessment. In the rabbit pre-natal
developmental toxicity study, a slight increase in the incidence of
abortions was observed from doses close to or at the limit dose (750 and
1000 mg/kg/day) while no evidence of toxicity *via* the dermal route was
reported after 21 days of exposure at a dose 2-fold higher than the
limit dose. Given the limited use pattern and low likelihood for chronic
durations of exposure for this compound, no rodent chronic toxicity or
carcinogenicity studies are required. It was negative in the
mutagenicity/ genetic toxicity studies.

[]{#__RefHeading___Toc185681380 .anchor}**3.1 Hazard and Dose-Response
Characterization**

[]{#__RefHeading___Toc185681381 .anchor}**3.1.1 Database Summary**

\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_

J.A. Kopicky and C.H. Packman (1986) *The mechanisms of sulfonyul-urea
induced immune hemolysis: Case report and review of the literature.*
Amer. J. Hematol.. **23(3)**: 283-288

Ehlhardt, W.J., *et al.* (1997) *Disposition and metabolism of the
sulfonyl urea oncolytic agent LY295501 in mouse, rat, and monkey.* Drug
Met. Disp. **(25):6**: 701-712

Lee, C.W. et al. (2002). A novel stereo-selective sulfonylurea,
1-\[1-(4-aminobenzoyl)-2,3-dihydro-1H-indol-6-sulfonyl\]-4-phenylimidazolidin-2-one,
has antitumor efficacy in in vitro and in vivo tumor models. Biochem.
Pharmacol. **64(3):** 473-480

[]{#__RefHeading___Toc185681382 .anchor}**3.1.1.1 Sufficiency of
studies/data**

Sulfometuron methyl is registered as a non-food use chemical. The
available toxicological data on sulfometuron methyl is limited, but
sufficient to assess the potential hazard that may result from
sulfometuron methyl exposure. The 21-day dermal and pre-natal
developmental toxicity studies in rats and rabbits were classified as
non-guideline due to multiple deficiencies and, therefore, were not used
for risk assessment purposes. The following study was used to select
toxicity endpoints and doses.

-   Chronic Feeding -- Dog: MRID No. 0129051

    []{#__RefHeading___Toc185681383 .anchor}**3.1.1.2 Mode of Action,
    Metabolism, Toxicokinetic Data**

Studies demonstrating the mode of action of sulfometuron methyl in
mammals have not been identified in the data base. In addition, no
metabolism or kinetic studies were identified in the literature

[]{#__RefHeading___Toc185681384 .anchor}**3.2 Absorption, Distribution,
Metabolism, Excretion (ADME)**

No data were available for assessment.

[]{#__RefHeading___Toc185681385 .anchor}**3.3 Hazard Identification and
Toxicity Endpoint Selection**

The toxicity endpoints and doses for risk assessment were selected based
upon the available toxicity data considering the use profile for
sulfometuron methyl. The selected toxicity endpoints and doses are
presented below.

[]{#__RefHeading___Toc185681386 .anchor}**3.3.1 Acute Reference Dose
(aRfD) -- All Population Subgroups**

[Study Selected]{.underline}: Chronic Feeding -- Dog

[MRID No.]{.underline}: 0129051

[Executive Summary]{.underline}: See Appendix A, Guideline \[§
870.4100\]

[Dose and Endpoint for Risk Assessment]{.underline}: A NOAEL of 27.5
mg/kg/day and LOAEL of 148.5 mg/kg/day were selected to establish an
aRfD based on hemolytic anemia in both sexes and decreased body-weight
gain in males beginning on the fourth week of exposure (and persisting
throughout the entire study).

[Uncertainty Factor(s)]{.underline}: 100X \[10 interspecies; 10X
intraspecies\]

[Comments about Study/Endpoint/Uncertainty Factors]{.underline}:
Although sulfumeturon methyl is considered a non-food/non-feed chemical
and no tolerances are associated with this registration, an aRfD was
established for the purposes of conducting a drinking water risk
assessment. Selection of the endpoint for the acute reference dose from
a chronic toxicity study provides a very conservative point of departure
for acute risk assessment. In the absence of fully acceptable guideline
studies which might yield a different acute endpoint (e.g., acceptable
developmental toxicity studies) and considering the limited findings in
the available developmental studies, use of the chronic dog endpoint
will be protective.

[]{.mark}

[]{#__RefHeading___Toc185681387 .anchor}**3.3.2** **Chronic Reference
Dose (cRfD)**

[Study Selected]{.underline}: Chronic Feeding -- Dog

[MRID No.]{.underline}: 0129051

[Executive Summary]{.underline}: See Appendix A, Guideline \[§
870.4100\]

[Dose and Endpoint for Risk Assessment]{.underline}: A NOAEL of 27.5
mg/kg/day and LOAEL of 148.5 mg/kg/day were selected to establish a cRfD
based on hemolytic anemia in both sexes and decreased body-weight gain
in males beginning on the fourth week of exposure (and persisting
throughout the entire study).

[Uncertainty Factor(s)]{.underline}: 100X \[10X interspecies; 10X
intraspecies\]

Comments about Study/Endpoint/Uncertainty Factors: The study duration
and route of exposure are appropriate for this risk assessment.
Moreover, a clear NOAEL for the effects of concern (hemolytic anemia,
body weight parameters, and alkaline phosphatase) has been identified in
the study.

[]{#__RefHeading___Toc185681388 .anchor}**3.3.3 Dermal Absorption**

No dermal absorption data are available. As a result, a default 100%
dermal absorption factor is assumed in this risk assessment.

[]{.mark}

[]{#__RefHeading___Toc185681389 .anchor}**3.3.4 Dermal Exposure (Short-,
Intermediate- and Long-Term)**

[Study Selected]{.underline}: Chronic Feeding -- Dog

[MRID No.]{.underline}: 0129051

[Executive Summary]{.underline}: See Appendix A, Guideline \[§
870.4100\]

[Dose and Endpoint for Risk Assessment]{.underline}: A NOAEL of 27.5
mg/kg/day and LOAEL of 148.5 mg/kg/day were selected to establish a cRfD
based on hemolytic anemia in both sexes and decreased body-weight gain
in males beginning on the fourth week of exposure (and persisting
throughout the entire study).

[Uncertainty Factor(s)]{.underline}: 100X \[10X interspecies; 10X
intraspecies\]

[Comments about Study/Endpoint/Uncertainty Factors]{.underline}: No
acceptable/guideline route-specific studies are available for this risk
assessment. As a result, the chronic toxicity study in dogs has been
selected for risk assessment purposes. Although no hematological or
clinical chemistry assessments are available at the 4-week interval, the
decreases in body weight gain noted beginning on the fourth week of the
study provide an appropriate endpoint for short-term risk assessment.
Since the hematological effects noted at the end of the study occurred
at the same dose level as the body weight gain decrements seen beginning
on the fourth week of the study, this study and endpoints are also
appropriate to assess potential intermediate- and long-term risks due to
sulfometuron methyl exposure.

[]{.mark}

[]{#__RefHeading___Toc185681390 .anchor}**3.3.5 Inhalation Exposure
(Short- and Intermediate -Term)**

[Study Selected]{.underline}: Chronic Feeding -- Dog

[MRID No.]{.underline}: 0129051

[Executive Summary]{.underline}: See Appendix A, Guideline \[§
870.4100\]

[Dose and Endpoint for Risk Assessment]{.underline}: A NOAEL of 27.5
mg/kg/day and LOAEL of 148.5 mg/kg/day were selected based on hemolytic
anemia in both sexes and decreased body weight gain in males beginning
on the fourth week of the study (and persisting throughout the entire
study).

[Uncertainty Factor(s)]{.underline}: 100X \[10X interspecies; 10X
intraspecies\]

[]{.mark}

[Comments about Study/Endpoint/Uncertainty Factors]{.underline}: With
the exception of the acute inhalation toxicity study, no
acceptable/guideline route-specific studies are available for this risk
assessment. As a result, the chronic toxicity study in dogs has been
selected for risk assessment purposes. Although no hematological or
clinical chemistry assessments are available at the 4-week interval, the
decreases in body weight gain noted beginning on the fourth week of the
study provide an appropriate endpoint for short-term risk assessment.
Since the hematological effects noted at the end of the study occurred
at the same dose level as the body weight gain decrements seen beginning
on the fourth week, this study and endpoints are also appropriate to
assess potential intermediate- and long-term risks due to sulfometuron
methyl exposure.

[]{#__RefHeading___Toc185681391 .anchor}**3.3.6 Level of Concern for
Margin of Exposure**

+--------------------+-------------------------+-----------------------+
| **Table 3.3.6.     |                         |                       |
| Summary of Levels  |                         |                       |
| of Concern for     |                         |                       |
| Risk Assessment**  |                         |                       |
+--------------------+-------------------------+-----------------------+
| **Route**          | **Short-Term**          | **Intermediate-Term** |
|                    |                         |                       |
|                    | **(1 - 30 Days)**       | **(1 - 6 Months)**    |
+--------------------+-------------------------+-----------------------+
| **Occupational     |                         |                       |
| (Worker)           |                         |                       |
| Exposure**         |                         |                       |
+--------------------+-------------------------+-----------------------+
| Dermal             | 100                     | 100                   |
+--------------------+-------------------------+-----------------------+
| Inhalation         | 100                     | 100                   |
+--------------------+-------------------------+-----------------------+
| **Residential      |                         |                       |
| Exposure**         |                         |                       |
+--------------------+-------------------------+-----------------------+
| Inhalation         | NA                      | NA                    |
+--------------------+-------------------------+-----------------------+
| Incidental Oral    | NA                      | NA                    |
+--------------------+-------------------------+-----------------------+

A 100X uncertainty factor should be applied. The Uncertainty Factor
accounts for both interspecies

extrapolation (10X) and intraspecies variability (10X).

[]{#__RefHeading___Toc185681392 .anchor}**3.3.7 Classification of
Carcinogenic Potential**

There are no carcinogenicity studies for sulfometuron methyl since it is
a non-food/non-feed pesticide and chronic exposure to this pesticide is
unlikely. It was negative in the available mutagenicity/genetic toxicity
studies.

[]{#__RefHeading___Toc185681393 .anchor}**3.3.8 Summary of Toxicological
Doses and Endpoints for Sulfometuron Methyl**

+-------------+-----------+--------+-----------+----------------------+
| **Table     |           |        |           |                      |
| 3.3.8.      |           |        |           |                      |
| Summary of  |           |        |           |                      |
| To          |           |        |           |                      |
| xicological |           |        |           |                      |
| Doses and   |           |        |           |                      |
| Endpoints   |           |        |           |                      |
| for         |           |        |           |                      |
| S           |           |        |           |                      |
| ulfometuron |           |        |           |                      |
| Methyl for  |           |        |           |                      |
| Use in      |           |        |           |                      |
| Dietary and |           |        |           |                      |
| Non-O       |           |        |           |                      |
| ccupational |           |        |           |                      |
| Human       |           |        |           |                      |
| Health Risk |           |        |           |                      |
| As          |           |        |           |                      |
| sessments** |           |        |           |                      |
+=============+===========+========+===========+======================+
| **          | **Point   | *      | **RfD,    | **Study and          |
| Exposure/** | of        | *Uncer | Level of  | Toxicological        |
|             | De        | tainty | Concern   | Effects**            |
| *           | parture** | Fac    | for Risk  |                      |
| *Scenario** |           | tors** | Ass       |                      |
|             |           |        | essment** |                      |
+-------------+-----------+--------+-----------+----------------------+
| Acute       | NOAEL=    | UF~A~= | Acute RfD | Chronic 1-year dog   |
| Dietary     | 27.5      | 10 x   | = 0.275   | study                |
| (all        | mg/kg/day |        | mg/kg/day |                      |
| population  |           | UF     |           | LOAEL = 148.5        |
| subgroups)  |           | ~H~=10 |           | mg/kg/day based on   |
|             |           | x      |           | decreases in body    |
|             |           |        |           | weight in males      |
|             |           |        |           | (beginning on the    |
|             |           |        |           | fourth week of       |
|             |           |        |           | exposure and         |
|             |           |        |           | persisted            |
|             |           |        |           | throughout),         |
|             |           |        |           | hemolytic anemia and |
|             |           |        |           | a slight increase in |
|             |           |        |           | alkaline phosphatase |
|             |           |        |           | in males and         |
|             |           |        |           | females.             |
+-------------+-----------+--------+-----------+----------------------+
| Chronic     |           |        | Chronic   |                      |
| Dietary     |           |        | RfD =     |                      |
| (All        |           |        | 0.275     |                      |
| P           |           |        | mg/kg/day |                      |
| opulations) |           |        |           |                      |
+-------------+-----------+--------+-----------+----------------------+
| Dermal      | NOAEL=    | UF~A~= | LOC for   |                      |
| Short-      | 27.5      | 10x    |           |                      |
| (1-30 days) | mg/kg/day |        | MOE = 100 |                      |
| and         |           | UF~H~= |           |                      |
| Interm      |           | 10x    |           |                      |
| ediate-Term |           |        |           |                      |
| (1-6        |           |        |           |                      |
| months)     |           |        |           |                      |
|             |           |        |           |                      |
| (no         |           |        |           |                      |
| residential |           |        |           |                      |
| uses)       |           |        |           |                      |
+-------------+-----------+--------+-----------+----------------------+
| Inhalation  |           |        |           |                      |
| Short-      |           |        |           |                      |
| (1-30 days) |           |        |           |                      |
| and         |           |        |           |                      |
| Interm      |           |        |           |                      |
| ediate-Term |           |        |           |                      |
| (1-6        |           |        |           |                      |
| months)     |           |        |           |                      |
|             |           |        |           |                      |
| (no         |           |        |           |                      |
| residential |           |        |           |                      |
| uses)       |           |        |           |                      |
+-------------+-----------+--------+-----------+----------------------+
| Cancer      | No data   |        |           |                      |
| (oral,      | available |        |           |                      |
| dermal,     | for       |        |           |                      |
| inhalation) | as        |        |           |                      |
|             | sessment. |        |           |                      |
+-------------+-----------+--------+-----------+----------------------+

Point of Departure (POD) = A data point or an estimated point that is
derived from observed dose-response data and used to mark the beginning
of extrapolation to determine risk associated with lower environmentally
relevant human exposures. NOAEL = no observed adverse effect level.
LOAEL = lowest observed adverse effect level. UF = uncertainty factor.
UF~A~ = extrapolation from animal to human (interspecies). UF~H~ =
potential variation in sensitivity among members of the human population
(intraspecies). RfD = reference dose. MOE = margin of exposure. LOC =
level of concern. N/A = not applicable.

[]{#__RefHeading___Toc185681394 .anchor}**3.4 Endocrine Disruption**

EPA is required under the FFDCA, as amended by 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 endocrine effects as the Administrator may designate."
Following 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 androgen 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. For pesticide chemicals,
EPA will use FIFRA and, to the extent that effects in wildlife may help
determine whether a substance may have an effect in humans, FFDCA
authority to require the wildlife evaluations. As the science develops
and resources allow, screening of additional hormone systems may be
added to the Endocrine Disruptor Screening Program (EDSP).

When additional appropriate screening and/or testing protocols being
considered under the Agency's EDSP have been developed, sulfometuron
methyl may be subjected to further screening and/or testing to better
characterize effects related to endocrine disruption.

[]{#__RefHeading___Toc185681395 .anchor}**4.0 Public Health and
Pesticide Epidemiology Data**

Incident report was incomplete at the time of document submission.

\[See R.H. Allen, M. Hawkins & H. Allender, D343943\]

[]{#__RefHeading___Toc185681396 .anchor}**5.0 Dietary Exposure/Risk
Characterization**

The only potential dietary exposures to sulfometuron methyl would be
from drinking water sources since this is a non-food/non-feed chemical.

[]{#__RefHeading___Toc185681397 .anchor}**5.1** **Pesticide Metabolism
and Environmental Degradation**

\[See M. Barrett, D334287, 10/31/2007\]

The body of environmental fate data submitted demonstrates sulfometuron
methyl is mobile and persistent in the environment. It is more soluble
in neutral and alkaline water than in acidic water. The major route of
dissipation for sulfometuron methyl is believed to be aerobic and
anaerobic degradation/ metabolism in soil and water (pseudo first-order
degradation half-lives generally around 2 to 6 months), with hydrolysis
potentially dominant under acidic conditions. Estimated drinking water
concentrations (EDWCs) were formulated for surface and ground water for
total residues including the parent compound, sulfometuron methyl, as
well as the potential water degradates sulfometuron free acid,
sulfometuron pyrimidine amine, sulfometuron sulfonamide, and saccharin.

**Drinking Water Exposure Estimation**

While some monitoring data are available, the data are not targeted to
watersheds known to present the highest exposure potential for
sulfometuron methyl. Consequently, EFED's Tier I models were used for
this drinking water exposure assessment.

**Surface Water Modeling**

The FIRST ([F]{.underline}QPA [I]{.underline}ndex
[R]{.underline}eservoir [S]{.underline}creening [T]{.underline}ool,
Version 1.1.0) model by the Environmental Fate and Effects Division
(EFED) of the USEPA Office of Pesticide Programs (OPP) was used to
assess potential for contamination of surface drinking water sources
from the proposed sulfometuron methyl use.

FIRST is a single-event model (one runoff event), but can account for
spray drift from multiple applications. FIRST is hardwired to represent
the Index Reservoir, a standard water body used by the Office of
Pesticide Programs to assess drinking water exposure (Office of
Pesticide Programs, 2002). It was based on a real reservoir, Shipman
City Lake in Illinois, which was known to be vulnerable to pesticide
contamination (with ample confirmation from pesticide monitoring data).
The single runoff event moves a maximum of 8% of the applied pesticide
into the reservoir. This amount can be reduced due to degradation on the
field and the effects of binding to soil in the field. FIRST also uses a
Percent Cropped Area (PCA) factor to adjust for the area within the
watershed that is planted to the modeled crop. The national default PCA
of 0.87 (i.e., 87 %) was applied in this assessment.

**Ground Modeling**

Sulfometuron methyl concentrations in ground water were estimated by the
Screening Concentration in Ground Water (SCI-GROW v2.3, Jul. 29, 2003)
model. SCI-GROW is a regression model used as a screening tool to
estimate pesticide concentrations found in groundwater used as drinking
water. SCI-GROW was developed by fitting a linear model to ground water
concentrations with the Relative Index of Leaching Potential (RILP) as
the independent variable. Groundwater concentrations were taken from
90-day average high concentrations from Prospective Ground Water
studies. The RILP is a function of aerobic soil metabolism and the
soil-water partition coefficient. The output of SCI-GROW represents the
concentrations of sulfometuron methyl residues that might be expected in
shallow unconfined aquifers under sandy soils.

Further information on these models can be found at the EFED water model
website at http://
[www.epa.gov/oppefed1/models/water/html](http://www.epa.gov/oppefed1/models/water/html).

**Model Inputs and Results (Drinking Water Estimated Concentrations)**

For a complete description of model inputs and results please reference
the following: M. Barrett, D334287, 10/31/2007. Table 5.1 presents the
EDWCs of total residues (i.e., parent compound and degradates) in
drinking water from surface and ground water sources as resulting from
EFED water modeling. Given the limited environmental fate data on the
degradates, no estimation of individual degradate concentrations is
possible at this time. The EDWCs cannot be manipulated to provide
separate degradate and parent compound values.

+-----------+-----------+-------+-------+-------------+-------------+
| **Table   |           |       |       |             |             |
| 5.1. Tier |           |       |       |             |             |
| I EDWCs   |           |       |       |             |             |
| for       |           |       |       |             |             |
| Sul       |           |       |       |             |             |
| fometuron |           |       |       |             |             |
| Total     |           |       |       |             |             |
| Residues  |           |       |       |             |             |
| from      |           |       |       |             |             |
| Forestry  |           |       |       |             |             |
| or Rights |           |       |       |             |             |
| of Way    |           |       |       |             |             |
| Uses\***  |           |       |       |             |             |
+===========+===========+=======+=======+=============+=============+
| **C       | **Appl    |       |       | **Peak Day  | **Annual    |
| hemical** | ication** |       |       | (Acute)**   | Average     |
|           |           |       |       |             | (Chronic)** |
+-----------+-----------+-------+-------+-------------+-------------+
| **Surface | **Rate    | **Num | **    | **Co        |             |
| Water**   | (lb       | ber** | Inter | ncentration |             |
|           | a.i./A)** |       | val** | (µg/L)**    |             |
|           |           |       |       |             |             |
|           |           |       | **(da |             |             |
|           |           |       | ys)** |             |             |
+-----------+-----------+-------+-------+-------------+-------------+
| Aerial    | 0.375     | 1     | NA    | *           | *           |
|           |           |       |       | *[32.35]{.u | *[21.82]{.u |
|           |           |       |       | nderline}** | nderline}** |
+-----------+-----------+-------+-------+-------------+-------------+
| Aerial    | 0.188     | 2     | 30    | 30.21       | 20.38       |
+-----------+-----------+-------+-------+-------------+-------------+
| **Ground  |           |       |       |             |             |
| Water**   |           |       |       |             |             |
+-----------+-----------+-------+-------+-------------+-------------+
| Aerial or | 0.375     | 1     | NA    | 1.13        | 1.13        |
| ground    |           |       |       |             |             |
+-----------+-----------+-------+-------+-------------+-------------+

\* Includes sulfometuron methyl, sulfometuron free acid, sulfometuron
pyrimidine amine, sulfometuron sulfonamide, and saccharin

[]{#__RefHeading___Toc185681398 .anchor}**5.2 Dietary Exposure
Estimates**

\[See W. Britton, D346139, 12/18/07\]

An unrefined acute and chronic screening-level drinking water only
dietary assessment was conducted for the herbicide sulfometuron methyl
using the Dietary Exposure Evaluation Model DEEM-FCID™, Version 2.03
which use food consumption data from the U.S. Department of
Agriculture's Continuing Surveys of Food Intakes by Individuals (CSFII)
from 1994-1996 and 1998 to calculate dietary risk. Sulfometuron methyl
is a non-food/non-feed use chemical with no current or proposed usages
which could lead to dietary exposures from raw agricultural commodities
and/or processed foods. Consequently, sulfometuron methyl dietary risk
was assessed based on drinking water exposures only. Also, FQPA
requirements are not applicable to the current action pursuant to this
RED, therefore, the screening level risk estimates are expressed as RfDs
rather than population adjusted doses (PADs).

The drinking water concentrations used in the dietary risk assessment
were provided by the Environmental Fate and Effects Division (EFED) in
the following memorandum: "Tier I Sulfometuron Methyl Drinking Water
Assessment for Reregistration Eligibility Decision Document" (M.
Barrett, D334287, 10/31/07) and incorporated directly, as single point
estimates, into this dietary assessment. This unrefined assessment
relied solely on modeling analyses to calculate both surface and ground
water EDWCs for exposure. A number of degradates were identified and
these have been added to the parent compound sulfometuron methyl. The
drinking water assessment, therefore, models the parent compound
sulfometuron methyl as well as the potential water degradates
sulfometuron free acid, sulfometuron pyrimidine amine, sulfometuron
sulfonamide, and saccharin, as the combined residues of parent and
metabolites. It is conservative in its approach and is unlikely to
underestimate the concentration of sulfometuron methyl in drinking
water. The highest ground and surface water (acute) EDWCs relevant to
the maximum supported use rate of sulfometuron methyl were 1.1 and 32.4
ppb, respectively. The highest ground and surface water (chronic) EDWCs
relevant to the maximum supported use rate of sulfometuron methyl were
1.1 and 21.8 ppb, respectively. Accordingly, the larger values of 32.4
(acute) and 21.8 (chronic) ppb were used in the present acute and
chronic screening-level drinking water dietary assessments. Again, food
uses were not incorporated into this evaluation since only
non-food/non-feed uses of sulfometuron methyl are being supported by the
registrant.

**Results for Acute Dietary Exposure Analysis**

An acute dietary risk analysis was conducted with the DEEM-FCID™ model
to form a conservative evaluation of exposure for sulfometuron methyl.
The acute analysis yielded estimates well below the 100% of the aRfD
threshold exposure level of concern for the US population and each
population subgroup. For the US Population, acute dietary risk was
calculated at \< 1 % of the aRfD with an exposure level of 0.0017
mg/kg/day. For the subgroup with the highest esimated exposure, all
infants less than 1 year old, acute dietary risk occupied 2.3 % of the
aRfD with an exposure of 0.0064 mg/kg/day. An overview summarizing the
results of the acute dietary assessment with the population subgroup
having the highest exposure being noted in bold is presented in Table
5.2.1.

  ----------------------- ----------------------------- -----------------
  **Table 5.2.1. Summary                                
  of Screening Level                                    
  Drinking Water Exposure                               
  and Risk for                                          
  Sulfometuron Methyl**                                 

  **Population Subgroup** **Acute Dietary^1^**          

                          **Dietary Exposure (95^th^    **%aRfD**
                          percentile) (mg/kg/day)**     

  General U.S. Population 0.001690                      \< 1

  **All Infants (\< 1     **0.006372**                  **2.3**
  year old)**                                           

  Children 1-2 years old  0.002652                      \< 1

  Children 3-5 years old  0.002422                      \< 1

  Children 6-12 years old 0.001686                      \< 1

  Youth 13-19 years old   0.001371                      \< 1

  Adults 20-49 years old  0.001566                      \< 1

  Adults 50+ years old    0.001414                      \< 1

  Females 13-49 years old 0.001575                      \< 1
  ----------------------- ----------------------------- -----------------

^1^ Acute dietary analysis based on a 0.275 mg/kg/day aRfD.

**Results of Chronic Dietary Exposure Analysis**

A chronic dietary risk analysis was conducted with the DEEM-FCID™ model
to form a conservative evaluation of exposure for sulfometuron methyl.
The chronic analysis yielded risk estimates well below the 100% of the
cRfD threshold level of concern for the US population and each
population subgroup. For the US population, chronic dietary risk was
calculated at \< 1 % of the cRfD with an exposure level of 0.00046
mg/kg/day. For the subgroup with the highest estimated exposure, all
infants less than 1 year old, chronic dietary risk occupied \< 1 % of
the cRfD with an exposure of 0.0015 mg/kg/day. An overview summarizing
the results of the chronic dietary assessment with the population
subgroup having the highest exposure being noted in bold is presented in
Table 5.2.2.

+-----------------------+---------------------------+------------------+
| **Table 5.2.2.        |                           |                  |
| Summary of Screening  |                           |                  |
| Level Drinking Water  |                           |                  |
| Exposure and Risk for |                           |                  |
| Sulfometuron Methyl** |                           |                  |
+=======================+===========================+==================+
| **Population          | **Chronic Dietary^1^**    |                  |
| Subgroup**            |                           |                  |
+-----------------------+---------------------------+------------------+
|                       | **Dietary Exposure        | **%cRfD**        |
|                       | (99^th^ percentile)**     |                  |
|                       |                           |                  |
|                       | **(mg/kg/day)**           |                  |
+-----------------------+---------------------------+------------------+
| General U.S.          | 0.000460                  | \< 1             |
| Population            |                           |                  |
+-----------------------+---------------------------+------------------+
| **All Infants (\< 1   | **0.001508**              | **\< 1**         |
| year old)**           |                           |                  |
+-----------------------+---------------------------+------------------+
| Children 1-2 years    | 0.000683                  | \< 1             |
| old                   |                           |                  |
+-----------------------+---------------------------+------------------+
| Children 3-5 years    | 0.000639                  | \< 1             |
| old                   |                           |                  |
+-----------------------+---------------------------+------------------+
| Children 6-12 years   | 0.000441                  | \< 1             |
| old                   |                           |                  |
+-----------------------+---------------------------+------------------+
| Youth 13-19 years old | 0.000332                  | \< 1             |
+-----------------------+---------------------------+------------------+
| Adults 20-49 years    | 0.000429                  | \< 1             |
| old                   |                           |                  |
+-----------------------+---------------------------+------------------+
| Adults 50+ years old  | 0.000452                  | \< 1             |
+-----------------------+---------------------------+------------------+
| Females 13-49 years   | 0.000428                  | \< 1             |
| old                   |                           |                  |
+-----------------------+---------------------------+------------------+

^1^ Chronic dietary analysis based on a 0.275 mg/kg/day cRfD.

**Summary**

The conservative acute and chronic screening-level drinking water
dietary assessment made with DEEM-FCID™ indicates that exposures to
sulfometuron are below HED's level of concern for the US population and
all population subgroups. Therefore, HED is not concerned that the
non-food/ non-feed use of sulfometuron methyl could result in
unacceptable risk through potential exposure from drinking water
sources.

[]{#__RefHeading___Toc185681399 .anchor}**6.0 Residential
(Non-Occupational) Exposure/Risk**

\[See W. Britton, D345025, 12/18/07\]

Residential exposure/risk (handler and postapplication) was not assessed
since label instructions prohibit applications of sulfometuron methyl to
residential or recreational settings.

[]{#__RefHeading___Toc185681400 .anchor}**6.1 Other (Spray Drift,
etc.)**

Spray drift is always a potential source of exposure to residents nearby
to spraying operations. This is particularly the case with aerial
application, but, to a lesser extent, could also be a potential source
of exposure from the ground application methods employed for
sulfometuron methyl. The Agency has been working with the Spray Drift
Task Force, EPA Regional Offices and State Lead Agencies for pesticide
regulation and other parties to develop the best spray drift management
practices. The Agency is now requiring interim mitigation measures for
aerial applications that must be placed on product labels/labeling. The
Agency has completed its evaluation of the new data base submitted by
the Spray Drift Task Force, a membership of U.S. pesticide registrants,
and is developing a policy on how to appropriately apply the data and
the AgDRIFT computer model to its risk assessments for pesticides
applied by air, orchard airblast and ground hydraulic methods. After the
policy is in place, the Agency may impose further refinements in spray
drift management practices to reduce off-target drift and risks
associated with aerial as well as other application types where
appropriate.

[]{#__RefHeading___Toc185681401 .anchor}**7.0 Aggregate Risk Assessments
and Risk Characterization**

An aggregate exposure assessment is typically conducted for non-food
chemicals when there is potential for human exposure through water and
residential pathways. Since sulfometuron methyl has no residential uses,
an aggregate exposure assessment was not performed.

[]{#__RefHeading___Toc185681402 .anchor}**8.0 Occupational Exposure/Risk
Pathway**

\[See W. Britton, D345025, 12/18/07\]

It has been determined there is a potential for exposure in occupational
settings from handling sulfometuron methyl products during the
application process (i.e., mixer/loaders, applicators, flaggers, and
mixer/loader/applicators). A risk assessment has been completed for the
occupational handling of sulfometuron methyl; however, an occupational
postapplication assessment of exposure to sulfometuron methyl was not
performed. Since sulfometuron methyl is a non-selective herbicide used
in non-agricultural areas, contact with previously treated areas is
likely to be insignificant.

Sulfometuron methyl is labeled for commercial pre- and post-emergent
applications to manage annual and perennial broadleaf weeds and grasses.
Application rates of sulfometuron methyl range from 0.03 to 0.38 pound
of active ingredient (ai) per acre. All sulfometuron methyl products are
formulated as WDG (ranging from 18 to 75% ai) and are directed to the
target via liquid sprays applications via aerial or ground application
methods. Applications of sulfometuron methyl can be made aerially
(helicopter and fixed-wing airplane) or by ground (high and low pressure
handwand, groundboom, and rights-of-way sprayer). Registered uses of
sulfometuron methyl include:

-   forestry (conifers, hardwoods, hybrid poplar plantations);

-   non-crop industrial sites (public, private, and military lands,
    rights-of-way, under asphalt and concrete);

-   turf (unimproved); and

-   non-crop habitat restoration sites.

Based upon the use pattern of sulfometuron methyl, HED anticipates both
short- and intermediate-term occupational exposure. Long-term handler
exposures are not expected to occur. The endpoint selected for dermal
and inhalation exposure is for short- and intermediate-term durations.
Risk estimates resulting from the assessment of dermal and inhalation
exposure were combined since it is logical that these routes of exposure
could co-occur.

[]{#__RefHeading___Toc185681403 .anchor}**8.1 Sulfometuron Methyl
Occupational Handler Exposure Scenarios**

Exposure to pesticide handlers is likely during the occupational use of
sulfometuron methyl based on the types of equipment and techniques that
can potentially be used. The quantitative exposure/risk assessment
developed for occupational handlers is based on the following scenarios.
Sulfometuron methyl exposure was estimated (combined dermal and
inhalation) using the Pesticide Handlers Exposure Database (PHED) data.
Mixer/loader exposure scenarios were estimated using PHED data specific
to dry flowable (DF) products since this formulation is most similar to
WDGs; however, all other tasks (i.e., applicators, flaggers, and
mixer/loader/applicators) were assessed with PHED data specific to
liquid products since the WDGs are mixed into and applied as a liquid.

***[Mixer/Loaders:]{.underline}***

\(1\) WDG: Aerial (Fixed Wing Airplane and Helicopter)

\(2\) WDG: Groundboom

\(3\) WDG: Right-of-Way Applications

> ***[Applicators:]{.underline}***

\(4\) Liquid: Aerial Applications (Fixed Wing Airplane and Helicopter)

\(5\) Liquid: Groundboom Applications

\(6\) Liquid: Rights of Way Applications

***[Flaggers:]{.underline}***

\(7\) Flagging for Aerial Sprays

***[Mixer/Loader/Applicators:]{.underline}***

\(8\) Liquid: Low Pressure Handwand Sprayer

[]{#__RefHeading___Toc185681404 .anchor}**8.1.1 Data and Assumptions for
Handler Exposure Scenarios**

**Assumptions for Handler Exposure Scenarios**

A series of assumptions and exposure factors served as the basis for
completing the occupational handler risk assessments. The assumptions
and factors used in the risk calculations include:

-   HED has patterned this risk assessment on a series of likely
    representative scenarios that are believed by HED to represent the
    vast majority of sulfometuron methyl uses;

-   Average body weight of an adult handler is 70 kg because the
    toxicity endpoint values used for the assessments are appropriate
    for average adult body weight representing the general population;

-   For non-cancer assessments, HED assumes the maximum application
    rates allowed by labels in its risk assessments;

-   Since no dermal absorption data are available, a default 100%
    absorption factor is assumed;

-   The average occupational workday is assumed to be 8 hours; and

-   The daily areas treated were defined for each handler scenario (in
    appropriate units) by determining the amount that can be reasonably
    treated in a single day (e.g. acres, square feet, or gallons per
    day). The assumptions for daily areas treated are taken from the HED
    ExpoSAC SOP #9: Standard Values for Daily Acres Treated in
    Agriculture which was completed on July 5, 2000.

    -   Aerial Applications for Forestry -- 1200 acres

    -   Groundboom Applications -- 200 acres

    -   Flaggers -- 350 acres

    -   Right-of-Way Sprayer -- 25 acres (based upon 1000 gallons/day,
        as specified by SOP #9, and a labeled rate of 40 gallons/acre)

    -   Low Pressure Handwand Sprayer -- 1 acre (based upon 40
        gallons/day, as specified by SOP #9, and a labeled rate of 40
        gallons/acre)

**Data for Handler Exposure Scenarios**

No chemical specific information was available for sulfometuron methyl
handler exposure assessments. All occupational handler exposure
estimates were completed using surrogate data from PHED. This data is
outlined in Appendix A in the following document: W. Britton, D345025,
12/18/07.

[]{#__RefHeading___Toc185681405 .anchor}**8.1.2 Occupational Handler
Exposure/Risk Estimates**

Short- and intermediate-term dermal and inhalation exposures/risks were
calculated for occupational handlers of sulfometuron methyl for
different exposure scenarios. Most of the handler short- and
intermediate-term scenarios assessed (dermal and inhalation combined)
resulted in risk estimates (MOEs) ≥ 100 at some level of personal
protection and, therefore, are not of concern. The exposure scenario
mixing/loading of WDGs for aerial application to forestry and non-crop
areas results in a combined MOE = 90 at the maximum level of personal
protection (double layer with gloves) and, therefore, is of potential
concern. A summary of risk calculations performed for occupational
sulfometuron methyl handlers at baseline PPE is presented below in Table
8.1.2a; a summary of calculations for occupational sulfometuron methyl
handlers with additional PPE is presented in Table 8.1.2b.

+---+----------+---------------+-------+-----+------+--------+-------+
| * |          |               |       |     |      |        |       |
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+===+==========+===============+=======+=====+======+========+=======+
| * | **Sc     | **Target**    | *     | **A | **D  | **I    | **C   |
| * | enario** |               | *App. | rea | erma | nhalat | ombin |
| N |          |               | Rate  | T   | l^c^ | ion^d^ | ed^e^ |
| o |          |               | ^b^** | rea | MO   | MOEs** | M     |
| . |          |               |       | ted | Es** |        | OEs** |
| * |          |               | **(lb | (ac |      |        |       |
| * |          |               | ai/ac | res |      |        |       |
|   |          |               | re)** | )** |      |        |       |
+---+----------+---------------+-------+-----+------+--------+-------+
| * |          |               |       |     |      |        |       |
| * |          |               |       |     |      |        |       |
| M |          |               |       |     |      |        |       |
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| * |          |               |       |     |      |        |       |
| * |          |               |       |     |      |        |       |
+---+----------+---------------+-------+-----+------+--------+-------+
| 1 | WDGs:    | Forestry      | 0.38  | 1   | 65   | 5600   | *     |
|   | Aerial   | (Hardwoods,   |       | 200 |      |        | *64** |
|   | E        | Conifers),    |       |     |      |        |       |
|   | quipment | Non-Crop      |       |     |      |        |       |
|   | (Fixed   | Areas         |       |     |      |        |       |
|   | Wing and | (Public,      |       |     |      |        |       |
|   | Hel      | Private,      |       |     |      |        |       |
|   | icopter) | Military      |       |     |      |        |       |
|   |          | Lands)        |       |     |      |        |       |
+---+----------+---------------+-------+-----+------+--------+-------+
|   |          | Turf          | 0.19  |     | 130  | 11000  | 130   |
|   |          | (Unimproved)  |       |     |      |        |       |
+---+----------+---------------+-------+-----+------+--------+-------+
|   |          | Non-Crop Land | 0.09  |     | 260  | 22000  | 260   |
|   |          | Restoration   |       |     |      |        |       |
+---+----------+---------------+-------+-----+------+--------+-------+
| 2 | WDGs:    | Forestry      | 0.38  | 200 | 390  | 33000  | 380   |
|   | Gr       | (Hardwoods,   |       |     |      |        |       |
|   | oundboom | Conifers),    |       |     |      |        |       |
|   | E        | Non-Crop      |       |     |      |        |       |
|   | quipment | Areas         |       |     |      |        |       |
+---+----------+---------------+-------+-----+------+--------+-------+
|   |          | Turf          | 0.19  |     | 780  | 66000  | 770   |
|   |          | (Unimproved)  |       |     |      |        |       |
+---+----------+---------------+-------+-----+------+--------+-------+
|   |          | Non-Crop Land | 0.09  |     | 1500 | 130000 | 1500  |
|   |          | Restoration   |       |     |      |        |       |
+---+----------+---------------+-------+-----+------+--------+-------+
| 3 | WDGs:    | R             | 0.38  | 25  | 3100 | 270000 | 3100  |
|   | Right    | ights-of-Way, |       |     |      |        |       |
|   | s-of-Way | Non-Crop      |       |     |      |        |       |
|   | E        | Areas         |       |     |      |        |       |
|   | quipment |               |       |     |      |        |       |
+---+----------+---------------+-------+-----+------+--------+-------+
|   |          | Turf          | 0.19  |     | 6200 | 530000 | 6100  |
|   |          | (Unimproved)  |       |     |      |        |       |
+---+----------+---------------+-------+-----+------+--------+-------+
|   |          | Non-Crop Land | 0.09  |     | 1    | 1      | 12000 |
|   |          | Restoration   |       |     | 2000 | 100000 |       |
+---+----------+---------------+-------+-----+------+--------+-------+
| * |          |               |       |     |      |        |       |
| * |          |               |       |     |      |        |       |
| A |          |               |       |     |      |        |       |
| p |          |               |       |     |      |        |       |
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| * |          |               |       |     |      |        |       |
| * |          |               |       |     |      |        |       |
+---+----------+---------------+-------+-----+------+--------+-------+
| 4 | Liquids: | Forestry      | 0.38  | 1   | 900  | 63000  | 840   |
|   | Aerial   | (Hardwoods,   |       | 200 |      |        |       |
|   | Appl     | Conifers),    |       |     |      |        |       |
|   | ications | Non-Crop      |       |     |      |        |       |
|   | (Fixed   | Areas         |       |     |      |        |       |
|   | Wing and |               |       |     |      |        |       |
|   | Hel      |               |       |     |      |        |       |
|   | icopter) |               |       |     |      |        |       |
+---+----------+---------------+-------+-----+------+--------+-------+
|   |          | Turf          | 0.19  |     | 1700 | 130000 | 1700  |
|   |          | (Unimproved)  |       |     |      |        |       |
+---+----------+---------------+-------+-----+------+--------+-------+
|   |          | Non-Crop Land | 0.09  |     | 3400 | 250000 | 3400  |
|   |          | Restoration   |       |     |      |        |       |
+---+----------+---------------+-------+-----+------+--------+-------+
| 5 | Liquids: | Forestry      | 0.38  | 200 | 1800 | 35000  | 1700  |
|   | Gr       | (Hardwoods,   |       |     |      |        |       |
|   | oundboom | Conifers),    |       |     |      |        |       |
|   | Appl     | Non-Crop      |       |     |      |        |       |
|   | ications | Areas         |       |     |      |        |       |
+---+----------+---------------+-------+-----+------+--------+-------+
|   |          | Turf          | 0.19  |     | 3700 | 70000  | 3500  |
|   |          | (Unimproved)  |       |     |      |        |       |
+---+----------+---------------+-------+-----+------+--------+-------+
|   |          | Non-Crop Land | 0.09  |     | 7300 | 140000 | 7000  |
|   |          | Restoration   |       |     |      |        |       |
+---+----------+---------------+-------+-----+------+--------+-------+
| 6 | Liquids: | R             | 0.38  | 25  | 160  | 53000  | 160   |
|   | Right    | ights-of-Way, |       |     |      |        |       |
|   | s-of-Way | Non-Crop      |       |     |      |        |       |
|   | Appl     | Areas         |       |     |      |        |       |
|   | ications |               |       |     |      |        |       |
+---+----------+---------------+-------+-----+------+--------+-------+
|   |          | Turf          | 0.19  |     | 320  | 110000 | 310   |
|   |          | (Unimproved)  |       |     |      |        |       |
+---+----------+---------------+-------+-----+------+--------+-------+
|   |          | Non-Crop Land | 0.09  |     | 630  | 210000 | 630   |
|   |          | Restoration   |       |     |      |        |       |
+---+----------+---------------+-------+-----+------+--------+-------+
| * |          |               |       |     |      |        |       |
| * |          |               |       |     |      |        |       |
| F |          |               |       |     |      |        |       |
| l |          |               |       |     |      |        |       |
| a |          |               |       |     |      |        |       |
| g |          |               |       |     |      |        |       |
| g |          |               |       |     |      |        |       |
| e |          |               |       |     |      |        |       |
| r |          |               |       |     |      |        |       |
| s |          |               |       |     |      |        |       |
| * |          |               |       |     |      |        |       |
| * |          |               |       |     |      |        |       |
+---+----------+---------------+-------+-----+------+--------+-------+
| 7 | Liquids: | Forestry      | 0.38  | 350 | 1300 | 42000  | 1300  |
|   | Aerial   | (Hardwoods,   |       |     |      |        |       |
|   | Sprays   | Conifers),    |       |     |      |        |       |
|   | (Fixed   | Non-Crop      |       |     |      |        |       |
|   | Wing and | Areas         |       |     |      |        |       |
|   | Hel      |               |       |     |      |        |       |
|   | icopter) |               |       |     |      |        |       |
+---+----------+---------------+-------+-----+------+--------+-------+
|   |          | Turf          | 0.19  |     | 2700 | 84000  | 2600  |
|   |          | (Unimproved)  |       |     |      |        |       |
+---+----------+---------------+-------+-----+------+--------+-------+
|   |          | Non-Crop Land | 0.09  |     | 5300 | 170000 | 5200  |
|   |          | Restoration   |       |     |      |        |       |
+---+----------+---------------+-------+-----+------+--------+-------+
| * |          |               |       |     |      |        |       |
| * |          |               |       |     |      |        |       |
| M |          |               |       |     |      |        |       |
| i |          |               |       |     |      |        |       |
| x |          |               |       |     |      |        |       |
| e |          |               |       |     |      |        |       |
| r |          |               |       |     |      |        |       |
| / |          |               |       |     |      |        |       |
| L |          |               |       |     |      |        |       |
| o |          |               |       |     |      |        |       |
| a |          |               |       |     |      |        |       |
| d |          |               |       |     |      |        |       |
| e |          |               |       |     |      |        |       |
| r |          |               |       |     |      |        |       |
| / |          |               |       |     |      |        |       |
| A |          |               |       |     |      |        |       |
| p |          |               |       |     |      |        |       |
| p |          |               |       |     |      |        |       |
| l |          |               |       |     |      |        |       |
| i |          |               |       |     |      |        |       |
| c |          |               |       |     |      |        |       |
| a |          |               |       |     |      |        |       |
| t |          |               |       |     |      |        |       |
| o |          |               |       |     |      |        |       |
| r |          |               |       |     |      |        |       |
| s |          |               |       |     |      |        |       |
| * |          |               |       |     |      |        |       |
| * |          |               |       |     |      |        |       |
+---+----------+---------------+-------+-----+------+--------+-------+
| 8 | Liquids: | Non-Crop      | 0.38  | 1   | 51   | 170000 | *     |
|   | Low      | Areas         |       |     |      |        | *51** |
|   | Pressure |               |       |     |      |        |       |
|   | Handwand |               |       |     |      |        |       |
+---+----------+---------------+-------+-----+------+--------+-------+
|   |          | Turf          | 0.19  |     | 100  | 340000 | 100   |
|   |          | (Unimproved)  |       |     |      |        |       |
+---+----------+---------------+-------+-----+------+--------+-------+
|   |          | Non-Crop Land | 0.09  |     | 210  | 680000 | 210   |
|   |          | Restoration   |       |     |      |        |       |
+---+----------+---------------+-------+-----+------+--------+-------+

a Baseline = Long pants, long-sleeved shirt, no gloves

b Application rate based upon maximum labeled value.

c Dermal MOE = Dermal NOAEL (27.5 mg/kg/day)/ ( Dermal Daily Dose
\[Reference W.Britton, 345025\])

d Inhalation MOE = Inhalation NOAEL (27.5 mg/kg/day) / ( Inhalation
Daily Dose \[Reference W.Britton, 345025\])

e Combined MOE = 1/((1/Dermal MOE)+(1/Inhalation MOE))

+---+----------+---------------+-------+-----+------+--------+--------+
| * |          |               |       |     |      |        |        |
| * |          |               |       |     |      |        |        |
| T |          |               |       |     |      |        |        |
| a |          |               |       |     |      |        |        |
| b |          |               |       |     |      |        |        |
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| 8 |          |               |       |     |      |        |        |
| . |          |               |       |     |      |        |        |
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| ^ |          |               |       |     |      |        |        |
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| * |          |               |       |     |      |        |        |
+---+----------+---------------+-------+-----+------+--------+--------+
| * | **Sc     | **Target**    | *     | **A | **D  | **I    | *      |
| * | enario** |               | *App. | rea | erma | nhalat | *Combi |
| N |          |               | Rate  | T   | l^b^ | ion^c^ | ned^d^ |
| o |          |               | ^a^** | rea | MO   | MOEs** | MOEs** |
| . |          |               |       | ted | Es** |        |        |
| * |          |               | **(lb | (ac |      |        |        |
| * |          |               | ai/ac | res |      |        |        |
|   |          |               | re)** | )** |      |        |        |
+---+----------+---------------+-------+-----+------+--------+--------+
| * |          |               |       |     |      |        |        |
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| M |          |               |       |     |      |        |        |
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| G |          |               |       |     |      |        |        |
| l |          |               |       |     |      |        |        |
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| s |          |               |       |     |      |        |        |
| L |          |               |       |     |      |        |        |
| e |          |               |       |     |      |        |        |
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| e |          |               |       |     |      |        |        |
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| o |          |               |       |     |      |        |        |
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| * |          |               |       |     |      |        |        |
| * |          |               |       |     |      |        |        |
+---+----------+---------------+-------+-----+------+--------+--------+
| 1 | WDGs:    | Forestry      | 0.38  | 1   | 91   | 5600   | 90     |
|   | Aerial   | (Hardwoods,   |       | 200 |      |        |        |
|   | E        | Conifers),    |       |     |      |        |        |
|   | quipment | Non-Crop      |       |     |      |        |        |
|   | (Fixed   | Areas         |       |     |      |        |        |
|   | Wing and | (Public,      |       |     |      |        |        |
|   | Hel      | Private,      |       |     |      |        |        |
|   | icopter) | Military      |       |     |      |        |        |
|   |          | Lands)        |       |     |      |        |        |
+---+----------+---------------+-------+-----+------+--------+--------+
| * |          |               |       |     |      |        |        |
| * |          |               |       |     |      |        |        |
| M |          |               |       |     |      |        |        |
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| L |          |               |       |     |      |        |        |
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| v |          |               |       |     |      |        |        |
| e |          |               |       |     |      |        |        |
| l |          |               |       |     |      |        |        |
| o |          |               |       |     |      |        |        |
| f |          |               |       |     |      |        |        |
| P |          |               |       |     |      |        |        |
| P |          |               |       |     |      |        |        |
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| * |          |               |       |     |      |        |        |
| * |          |               |       |     |      |        |        |
+---+----------+---------------+-------+-----+------+--------+--------+
| 8 | Liquids: | Non-Crop      | 0.38  | 1   | 1    | 170000 | 12000  |
|   | Low      | Areas         |       |     | 2000 |        |        |
|   | Pressure |               |       |     |      |        |        |
|   | Handwand |               |       |     |      |        |        |
+---+----------+---------------+-------+-----+------+--------+--------+

a Application rate based upon maximum labeled value.

b Dermal MOE = Dermal NOAEL (27.5 mg/kg/day)/ ( Dermal Daily Dose
\[Reference W.Britton, 345025\])

c Inhalation MOE = Inhalation NOAEL (27.5 mg/kg/day) / ( Inhalation
Daily Dose \[Reference W.Britton, 345025\])

d Combined MOE = 1/((1/Dermal MOE)+(1/Inhalation MOE))

[]{#__RefHeading___Toc185681406 .anchor}**8.1.3 Risk Characterization**

The occupational handler dermal exposure scenario is the only scenario
for which significant risks were estimated for some uses; other risk
assessments completed (e.g., chronic and acute drinking water) were not
of concern. Due to a number of deficiencies identified in the conduct of
the 21-day dermal study, it was deemed unsuitable for endpoint
selection. In lieu of a route-specific study, the endpoint from the
chronic oral toxicity study in dogs was used to estimate the potential
for risk from dermal exposure to sulfometuron methyl. The Agency is
confident that the use of the chronic oral study results in a health
protective risk assessment for the following reasons:

-   Although the 21-day dermal study had significant flaws, no toxicity
    was observed at 2000 mg/kg/day following 21 days of dosing;

-   The results of the acute dermal toxicity study in rabbits shows an
    LD~50~ [\>]{.underline} 2000 mg/kg \[Toxicity Category III\]); and

-   Dermal risks, which drive handler risks, were calculated assuming
    100% dermal absorption due to lack of acceptable dermal absorption
    data. Assuming even a slightly lower dermal absorption of 90%, which
    is still likely to exceed the actual dermal absorption, would result
    in risk estimates which are not of concern for all scenarios,
    assuming some level of personal protective equipment is employed.

The exposure scenario mixing/loading of WDGs for aerial application to
forestry and non-crop areas results in the lowest combined MOE = 90 at
the maximum level of personal protection (double layer with gloves).
While this exposure scenario is of potential concern, this concern is
significantly reduced because of the use of the conservative inputs
described above.

**8.2 Occupational Postapplication Exposures and Risks**

HED uses the term "postapplication" to describe exposures to individuals
that occur as a result of being in an environment that has been
previously treated with a pesticide (also referred to as reentry
exposure). HED believes that there are distinct job functions or tasks
related to the kinds of activities that occur in previously treated
areas. Job requirements (e.g., the kinds of jobs to cultivate a crop),
the nature of the crop or target that was treated and how the chemical
residues degrade in the environment can cause exposure levels to differ
over time.

An assessment of occupational postapplication exposure to sulfometuron
methyl was not performed. Since sulfometuron methyl is a non-selective
herbicide used in non-agricultural areas, HED has determined that
contact with previously treated areas is likely to be insignificant.

[]{#__RefHeading___Toc185681407 .anchor}**9.0 Data Needs and Label
Recommendations**

No additional data are required.

[]{#__RefHeading___Toc185681408 .anchor}**Appendix A: Toxicology
Assessment**

**A.1 Toxicology Data Requirements**

The requirements (40 CFR 158.340) for a non food/feed use for
sulfometuron methyl are in Table 1. Use of the new guideline numbers
does not imply that the new (1998) guideline protocols were used.

+-----------------------------------------+-------------+-------------+
| **Test**                                | **          |             |
|                                         | Technical** |             |
+=========================================+=============+=============+
|                                         | *           | **          |
|                                         | *Required** | Satisfied** |
+-----------------------------------------+-------------+-------------+
| 870.1100 Acute Oral Toxicity            | yes         | yes         |
|                                         |             |             |
| 870.1200 Acute Dermal Toxicity          | yes         | yes         |
|                                         |             |             |
| 870.1300 Acute Inhalation Toxicity      | yes         | yes         |
|                                         |             |             |
| 870.2400 Primary Eye Irritation         | yes         | yes         |
|                                         |             |             |
| 870.2500 Primary Dermal Irritation      | yes         | yes         |
|                                         |             |             |
| 870.2600 Dermal Sensitization           | yes         | yes         |
+-----------------------------------------+-------------+-------------+
| 870.3100 Oral Subchronic (rodent)       | yes^1^      | yes^2^ -    |
|                                         | yes^1^      | no - -      |
| 870.3150 Oral Subchronic (nonrodent)^1^ | yes^1^ no   |             |
|                                         | no          |             |
| 870.3200 21-Day Dermal                  |             |             |
|                                         |             |             |
| 870.3250 90-Day Dermal                  |             |             |
|                                         |             |             |
| 870.3465 90-Day Inhalation              |             |             |
+-----------------------------------------+-------------+-------------+
| 870.3700a Developmental Toxicity        | yes yes no  | no no -     |
| (rodent)                                |             |             |
|                                         |             |             |
| 870.3700b Developmental Toxicity        |             |             |
| (nonrodent)                             |             |             |
|                                         |             |             |
| 870.3800 Reproduction                   |             |             |
+-----------------------------------------+-------------+-------------+
| 870.4100a Chronic Toxicity (rodent)     | no no no no | no yes no   |
|                                         |             | no          |
| 870.4100b Chronic Toxicity (nonrodent)  | no          |             |
|                                         |             | no          |
| 870.4200a Oncogenicity (rat)            |             |             |
|                                         |             |             |
| 870.4200b Oncogenicity (mouse)          |             |             |
|                                         |             |             |
| 870.4300 Chronic/Oncogenicity           |             |             |
+-----------------------------------------+-------------+-------------+
| 870.5100 Mutagenicity---Gene Mutation - | yes yes yes | yes yes yes |
| bacterial                               | yes         | yes         |
|                                         |             |             |
| 870.5300 Mutagenicity---Gene Mutation - |             |             |
| mammalian                               |             |             |
|                                         |             |             |
| 870.5xxx Mutagenicity---Structural      |             |             |
| Chromosomal Aberrations                 |             |             |
|                                         |             |             |
| 870.5xxx Mutagenicity---Other Genotoxic |             |             |
| Effects                                 |             |             |
+-----------------------------------------+-------------+-------------+
| 870.6100a Acute Delayed Neurotox. (hen) | no          | \-          |
|                                         |             |             |
| 870.6100b 90-Day Neurotoxicity (hen)    | no no no no | \- - - -    |
|                                         |             |             |
| 870.6200a Acute Neurotox. Screening     |             |             |
| Battery (rat)                           |             |             |
|                                         |             |             |
| 870.6200b 90-Day Neuro. Screening       |             |             |
| Battery (rat)                           |             |             |
|                                         |             |             |
| 870.6300 Develop. Neuro                 |             |             |
+-----------------------------------------+-------------+-------------+
| 870.7485 General Metabolism             | no          | \- no       |
|                                         |             |             |
| 870.7600 Dermal Penetration             | no          |             |
+-----------------------------------------+-------------+-------------+
| Special Studies for Ocular Effects      | no no no    | \- - -      |
|                                         |             |             |
| > Acute Oral (rat)                      |             |             |
| >                                       |             |             |
| > Subchronic Oral (rat)                 |             |             |
| >                                       |             |             |
| > Six-month Oral (dog)                  |             |             |
+-----------------------------------------+-------------+-------------+

^1^ Conditionally required

^2^ Chronic dog study satisfies requirement for a subchronic toxicity
study in the rodent

[]{.mark}

[]{.mark}

**A.2 Toxicity Profiles**

  ---------------- ----------------------- ---------- ------------ ---------------
  **Table A.2.1                                                    
  Acute Toxicity                                                   
  Profile - Test                                                   
  Substance^1^**                                                   

  Guideline No.    Study Type              MRID       Results      Toxicity
                                           No.(s)                  Category

  870.1100         Acute oral rat          43089201   LD~50~       IV
                                                      \>5g/kg      

  870.1200         Acute dermal rabbit     43089202   LD~50~       III
                                                      \>2g/kg      

  870.1300         Acute inhalation rat    43089203   LC~50~ \>5.0 IV
                                                      mg/L         

  870.2400         Acute eye irritation    00071412   Minimal      III
                   rabbit                             irritant     

  870.2500         Acute dermal irritation 41672808   Not a dermal IV
                   rabbit                             irritant\*   

  870.2600         Skin sensitization      43089204   Not a dermal N/A
                   rabbit                             sensitizer   
  ---------------- ----------------------- ---------- ------------ ---------------

^1^ All studies were conducted on technical grade Sulfometuron methyl,
of at least 98.8%, purity.

\* Minimal skin irritation was noted in the acute dermal toxicity study
(MRID No. 43089202) and an older dermal irritation study of a 75%
formulation (MRID No. 00071411)

+--------+------------+-----------------+------------------------------+
| *      |            |                 |                              |
| *Table |            |                 |                              |
| A.2.2  |            |                 |                              |
| Subch  |            |                 |                              |
| ronic, |            |                 |                              |
| C      |            |                 |                              |
| hronic |            |                 |                              |
| and    |            |                 |                              |
| Other  |            |                 |                              |
| To     |            |                 |                              |
| xicity |            |                 |                              |
| Pro    |            |                 |                              |
| file** |            |                 |                              |
+========+============+=================+==============================+
| **Gui  | **Study    | **MRID No.      | **Results**                  |
| deline | Type**     | (year)/         |                              |
| No.**  |            | Classification  |                              |
|        |            | /Doses**        |                              |
+--------+------------+-----------------+------------------------------+
| 87     | 21-Day     | 00126714 (1983) | NOAEL = 2000 mg/kg/day       |
| 0.3200 | dermal     | Acceptabl       |                              |
|        | toxicity   | e/non-guideline | LOAEL = Not observed         |
|        | (rabbit)   | M/F: 0, 125,    |                              |
|        |            | 500, 2000       |                              |
|        |            | mg/kg/day       |                              |
+--------+------------+-----------------+------------------------------+
| 870    | Prenatal   | 00078798 (1981) | **Maternal** NOAEL =300      |
| .3700a | dev        | Acceptabl       | mg/kg/day (HDT)              |
|        | elopmental | e/non-guideline |                              |
|        | (rabbit)   | F:0, 30, 100,   | LOAEL = 750 mg/kg/day based  |
|        |            | 300 mg/kg/day   | on abortion observed in the  |
|        |            |                 | range-finding study.         |
|        |            |                 |                              |
|        |            |                 | **Developmental** NOAEL =300 |
|        |            |                 | mg/kg/day                    |
|        |            |                 |                              |
|        |            |                 | LOAEL not observed           |
+--------+------------+-----------------+------------------------------+
|        | Prenatal   | 00078797 (1981) | **Maternal** LOAEL = 750     |
|        | dev        |                 | mg/kg/day based on abortion  |
|        | elopmental | F: 100, 300,    |                              |
|        | (rabbit)   | 750, 1000       |                              |
|        | --         |                 |                              |
|        | Ran        | mg/kg/day       |                              |
|        | ge-finding |                 |                              |
|        | study      |                 |                              |
+--------+------------+-----------------+------------------------------+
| 870    | Prenatal   | 00078796 (1981) | **Materna**l NOAEL\> 433     |
| .3700b | dev        | Unaccep         | mg/kg/day LOAEL not observed |
|        | elopmental | table/guideline |                              |
|        | in (rat)   | Run I F: 0,     | **Developmenta**l NOAEL\>433 |
|        |            | 5,000, 20,000,  | mg/kg/day                    |
|        |            | 40,000 and      |                              |
|        |            | 60,000 ppm Run  | LOAEL not observed           |
|        |            | II & III F: 0,  |                              |
|        |            | 50, 1000 and    |                              |
|        |            | 5,000 ppm (433  |                              |
|        |            | mg/kg/day)      |                              |
+--------+------------+-----------------+------------------------------+
| 870    | Chronic    | 00129051 (1983) | NOAEL = 27.5mg/kg/day        |
| .4100b | toxicity   | Accep           |                              |
|        | (dog)      | table/guideline | LOAEL = 148.5 mg/kg/day,     |
|        |            | M: 0, 5.2,      | based on hemolytic anemia in |
|        |            | 27.5, 152.6     | both sexes, decreased        |
|        |            | mg/kg/day F: 0, | body-weight gain in males,   |
|        |            | 5.3, 28.3, and  | and increased alkaline       |
|        |            | 148.5 mg/kg/day | phosphatase in males and     |
|        |            |                 | females. Effects on body     |
|        |            |                 | weight were observed         |
|        |            |                 | beginning on the fourth week |
|        |            |                 | of exposure (and persisting  |
|        |            |                 | throughout the study).       |
+--------+------------+-----------------+------------------------------+
| Gene   | S          | 00078792 (1979) | No mutagenic activity for    |
| Mu     | almonella/ | Accep           | all strains of bacteria      |
| tation | Microsome  | table/guideline | tested.                      |
|        | assay      | in strains TA   |                              |
|        |            | 1535, TA 1537,  |                              |
|        |            | TA 98 and TA    |                              |
|        |            | 100 in the      |                              |
|        |            | presence or     |                              |
|        |            | absence of      |                              |
|        |            | activation.     |                              |
+--------+------------+-----------------+------------------------------+
| Gene   | Chinese    | 00078793 (1981) | No mutagenic activity with   |
| mu     | Hamster    |                 | or without activation.       |
| tation | Ovary      | Accep           |                              |
|        |            | table/guideline |                              |
|        |            |                 |                              |
|        |            | CHO cell line   |                              |
|        |            | was used to     |                              |
|        |            | detect          |                              |
|        |            | mutations for   |                              |
|        |            | HGPRT           |                              |
+--------+------------+-----------------+------------------------------+
| Chrom  | Chinese    | 00146846 (1981) | No increase in chromosome    |
| o-some | Hamster    |                 | damage and aberrations.      |
| aber   | Ovary in   | Accep           |                              |
| ration | vitro      | table/guideline |                              |
|        | c          |                 |                              |
|        | ytogenetic | CHO in vitro    |                              |
|        | assay      | assay with and  |                              |
|        |            | without         |                              |
|        |            | activation      |                              |
+--------+------------+-----------------+------------------------------+
| Un-sch | U          | 00146847 (1983) | No induction of UDS was      |
| eduled | nscheduled |                 | observed.                    |
| DNA    | DNA        | Accep           |                              |
| syn    | synthesis  | table/guideline |                              |
| thesis | in rat     |                 |                              |
|        | h          |                 |                              |
|        | epatocytes |                 |                              |
|        | *in vitro* |                 |                              |
+--------+------------+-----------------+------------------------------+

**A.3 Executive Summaries**

**A.3.1 870.3200 21-Day Dermal Toxicity -- Rabbit**

In a repeated-dose dermal toxicity study (MRID No. 00126714),
sulfometuron-methyl (purity and batch/lot \# were not reported) was
applied as an aqueous paste to the shaved intact skin (surface area
treated not reported) of 5 New Zealand White rabbits/sex/dose at dose
levels of 0, 125, 500, or 2000 mg/kg/day, 6 hours/day for 21 consecutive
days. At the conclusion of the treatment period, 3 rabbits/sex/dose were
sacrificed and subjected to gross and microscopic pathological
evaluations. The remaining 2 rabbits/sex/dose were allowed to recover
for 14 days, after which the animals were sacrificed and subjected to
gross and microscopic pathological evaluations.

No adverse compound-related effects were observed in mortality, clinical
signs of toxicity, body weight, hematology, clinical chemistry, or gross
or microscopic pathology in either sex.

**The LOAEL was not observed. The NOAEL is 2000 mg/kg/day (2x the limit
dose).**

The study is classified as acceptable/non-guideline and it does not
satisfy the guideline requirement for a 21-day dermal toxicity study
(OPPTS 870.3200; OECD 410) in rabbits. The study is considered
non-guideline due to a number of deficiencies which include: test
animals utilized were diseased, daily observation and dermal irritation
data were absent, no animal husbandry data were available, no organ
weight data were provided, no purity lot/batch or stability data were
submitted, no compliance statements were presented. In addition, too few
animals per group were tested to meet guideline requirements.

**A.3.2 Prenatal Developmental Toxicity**

**870.3700a Prenatal Developmental Toxicity Study - Rat**

In a developmental toxicity study (MRID No. 00078796) sulfometuron
methyl (98.8%; Batch \# 13647-02) was initially fed to 10, 10, 11, 13
and 2 Sprague Dawley rats/group at dietary concentrations of 0, 5000,
20,000, 40,000, or 60,000 ppm, respectively, from gestation days 6-15
(identified in the study as Run I). Subsequently, the doses were reduced
and the study repeated, in two additional runs (II and III) with
combined totals of 35 (plus the 10 animals from Run I), 25, 23, and 15
rats (plus the two animals from Run I) per group at dietary dose levels
of 0, 50, 1000, or 5000 ppm, respectively, from gestation days (GD)
6-15. On GD 21, all dams were euthanized, and the uterus was removed via
cesarean section and its contents examined. Fetuses were examined for
external, visceral, and skeletal malformations and variations. The
applicable data from study runs I, II and III were combined although
these studies were not concurrent. No rationale for dietary
administration was provided.

There were no mortalities and no treatment-related clinical signs or
macroscopic findings. During the treatment interval, decreases
(p[\<]{.underline}0.05) in maternal body weight gain (decr. 11%) and
food consumption (decr. 4%) were observed at 5000 ppm compared to
controls. The small change in weight gain is minimal (represents only
6.4 grams in a 300 gram animal, or a change of just 2% in body weight)
and appears to be associated with reduced food consumption at the high
dose. Therefore, the effect might be associated with diet palatability
rather than toxicity in consideration of the high concentration in diet
during Runs II and III (5000 ppm) and up to 60,000 ppm in Run I. In
addition, the corrected body weights and body weight gains at day 21 are
not affected suggesting further that there is no significant overt
maternal toxicity at any dose level in this study. During the
post-treatment interval, body weights and body weight gains in this
group were comparable to controls. However, no individual animal data
were available to confirm this assessment.

**A maternal LOAEL was not observed at 5000 ppm (equivalent to 433
mg/kg/day), the highest dose tested (HDT).**

There were no abortions, premature deliveries, or complete litter
resorptions. Furthermore, there were no effects of treatment on numbers
of litters, live fetuses, deaths/resorptions, or on post-implantation
loss. However, no individual animal data were available in the submitted
report to confirm this assessment.

Fetal body weights were decreased (p[\<]{.underline}0.05) by 5% at 5000
ppm. This finding might be associated with the reduced food consumption
observed in dams at this dose level which appears to have contributed to
a slight reduction in their mean body weights (however, no individual
food consumption or body weight data were available in the submitted
report to assess or confirm these findings) and therefore the effect
observed at the high dose level (5000 ppm) could be associated with
slightly reduced dietary consumption and body weight of the dams. Also
note that one reported concern of the investigators was palatability at
such a high dietary dose and typically dietary developmental toxicity
studies are avoided in the assessment of developmental toxicity for
similar and other reasons which complicate interpretation of maternal
and developmental toxicity. Thus, fetal weight reductions observed might
be associated with reduced dietary consumption of dams with associated
maternal effects (slightly lower body weights) and might not reflect
actual fetal toxicity. Further, this effect represents only a 0.2 gram
difference in mean fetal weights as compared to controls and only a 0.1
gram difference as compared to mean fetal weights at the low dose level,
a dose 1/100^th^ of the high dose level. In addition, mean litter size
was also greatest at the high dose level which also might result in
slightly smaller fetal weights at that level. No individual animal data
were provided in the report to support the summary data assessment.

There were no treatment-related external, visceral, or skeletal
malformations or variations. However, no individual litter data were
provided in the test report.

**A developmental LOAEL was not observed in this dietary developmental
toxicity study at 5000 ppm (equivalent to 433 mg/kg/day).**

This study is classified as **unacceptable/guideline** and it does not
satisfy the guideline requirement for a developmental toxicity study in
rats (OPPTS 870.3700; OECD 414). Overt maternal toxicity was not
demonstrated in this dietary study. In addition, while under certain
circumstances dietary developmental studies may be considered as
acceptable, no rationale/justification was included in the report to
support administration via this route.

**870.3700b Prenatal Developmental Toxicity Study -- Rabbit**

In a developmental toxicity study (MRID No. 00078798)
Sulfometuron-methyl (100% a.i.; Batch \# not provided) in 0.5% aqueous
methylcellulose was administered via oral gavage at a dose volume of 4
mL/kg to 17 artificially inseminated New Zealand White rabbits/dose
group at doses of 0, 30, 100, or 300 mg/kg/day from gestation days (GD)
6-18. On GD 29, all does were euthanized, and the uterus was removed via
cesarean section and its contents examined. Fetuses were examined for
external, visceral, and skeletal malformations and variations.

There were no mortalities and no treatment-related clinical signs or
macroscopic findings. During the treatment interval (GD 6-18), decreased
maternal body weight gains of 44% were observed at the HDT (300
mg/kg/day), as compared to controls. Further evaluation of this finding
revealed that this percent reduction in body weight gain at the high
dose level constitutes only a 95.8 gram difference in animals of greater
than 4 kg mean body weight, is not of biological significance and no
toxicity was observed associated with this finding. Also note that on
gestation day 29, corrected body weights showed no effects at any dose
level. No abortions were noted in this study at any dose level up to the
HDT, 300 mg/kg/day.

In a range-finding developmental toxicity study, five females per dose
level received dose levels of 100, 300, 750 and 1000 mg/kg/day (see
Appendix to this DER) (MRID No. 00078797). In this study, abortion was
observed in one doe at 100 mg/kg/day, 0 does at 300 mg/kg/day, 2 does at
750 mg/kg/day, and 2 does at 1000 mg/kg/day. During peer review of these
data by RRB1, it was concluded that abortion was considered as maternal
toxicity and a LOAEL was determined for this effect at 750 mg/kg/day. It
is also noted that several other dams died at the 100 and 300 mg/kg/day
dose level likely associated with dosing error. It is therefore unclear
whether the abortions observed were also associated with dosing error or
due to test material toxicity since no pathology data were available.
Further, no abortions were observed at the 300 mg/kg/day dose level
which is 3x the dose where abortion was first observed at the 100
mg/kg/day level, no abortion was observed in the definitive study at
dose levels up to 300 mg/kg/day (HDT) and no dose response increase in
the level of abortion was observed at the high dose level in this
range-study.

**Due to the increase in abortion observed in the range-finding study,
the maternal LOAEL was established at 750 mg/kg/day. The maternal NOAEL
is 300 mg/kg/day (HDT).**

There were no complete litter resorptions at any dose level.
Furthermore, there were no effects of treatment on numbers or
percentages of resorptions, live fetuses, or dead fetuses, or on the
number of litters, sex ratio, or post-implantation loss. Fetal body
weights and length were unaffected by treatment. There were no
treatment-related effects on skeletal ossification. There were no
treatment-related external, visceral, or skeletal malformations or
variations.

The developmental LOAEL was not observed. The developmental NOAEL is 300
mg/kg/day (HDT). Based on the results of the range-finding study, much
higher dose levels should have been used in the definitive study (dose
levels\<750 mg/kg/day were supportable) and the fact that no toxicity
was observed in this study, this developmental toxicity study in the
rabbit is considered inadequate to assess the potential developmental
toxicity of sulfometuron methyl.

This study is classified **acceptable/non-guideline** and does not
satisfy the guideline requirement for a developmental toxicity study
(OPPTS 870.3700; OECD 414) in rabbits. The study is considered
non-guideline because dosing was considered inadequate, based on the
lack of maternal toxicity observed at the highest dose level in the
definitive study; the results of the range-finding study indicated that
a dose less than 750 mg/kg/day would be appropriate for the definitive
study.

**A.3.3 Reproductive Toxicity**

**870.3800 Reproduction and Fertility Effects -- Rat**

No reproductive toxicity study is available in the data base and no
study is required as this is not a food or feed use.

[]{.mark}

**A.3.4 Chronic Toxicity**

**870.4100b Chronic Toxicity - Dog**

In a chronic toxicity study in dogs (MRID No. 00129051),
sulfometuron-methyl (98.8-100% a.i., Batch Nos. INT-5648-12 and
INT-5648-13) was administered daily in the diet to 6 beagle
dogs/sex/dose for 1 year at concentrations of 0, 200, 1000, or 5000 ppm
(equivalent to 0/0, 5.2/5.3, 27.5/28.3, and 152.6/148.5 mg/kg/day in
males/females). Additionally, a palatability study was completed where 1
dog/sex/dose was treated with the test compound in the diet at 5000 or
7500 ppm for 4 weeks.

No adverse, treatment-related effects were observed on mortality,
clinical signs, food consumption, food efficiency, urinalysis or gross
pathology. The 5000 ppm males lost weight during the first 4 weeks (-0.3
kg), when food consumption was similar to controls. In addition, overall
body weight gain was also decreased in the 5000 ppm males (-1.3 kg
treated vs 0.2 kg controls) at week 53. Due to the early reductions in
body weight gain observed during weeks 0-2 and 0-4, it might be assumed
that the reduction in gain could be associated with diet palatability
but only a very slight and non-significant reduction in food consumption
was apparent in males.

Sulfometuron methyl induces hemolytic anemia in male and female dogs.
Statistically significant decreases (p≤0.05) in erythrocyte count,
hemoglobin, and hematocrit were noted in the 5000 ppm males (↓13-17%)
and in females at both the 1000 and 5000 ppm dose levels (↓8-10%) at 12
months. Decreases were apparent at other sampling intervals during the
study, but no statistical assessment was performed at these other times.
In addition, increases in platelet count were concurrently observed.
Decreases in monocytes were observed in females at all dose levels at
both the 6 month and 12 month assessment intervals, but not at the 9
month interval at any dose level. Therefore, it is unclear whether the
observed effect on monocytes is a real manifestation of toxicity. Mildly
increased hemosiderin was noted in the spleen of 3/6 females at 5000 ppm
vs 0/6 controls. These effects were considered indicative of hemolytic
anemia and considered compound related.

Increased serum alkaline phosphatase levels were observed in the 5000
ppm males (↑11-113%) and females (↑26-181%). This increase grew in
magnitude with the duration of treatment and was determined to be
statistically different (p≤0.05) from the controls at 12 months in both
males and females. Increased alkaline phosphatase was also apparent at
the 1000 ppm level in females. However, statistical significance was
only assessed at 12-months. Cholesterol was increased in the 1000 ppm
females from 7-37% for months 1, 3, 6, 9 and 12 and in 5000 ppm females
over the same sampling periods (↑14-33%) with statistical significance
(p≤0.05) at the 12 month interval.

Statistically significantly increased (p\<0.05) absolute liver weights
were noted in 5000 ppm females and increased relative liver weights were
observed in male and female 5000 ppm groups. In the absence of
associated histopathological changes in the liver, the increased liver
weight might be considered compensatory and not adverse. In addition,
increased absolute and relative thymus weights were noted in 5000 ppm
females. Increased thymus weights were also observed in males at all
dose levels but without an apparent dose response relationship.

At 5000 ppm, increased incidences of small prostate and mild atrophic
acini in the prostate were noted (2/6 treated vs 0/6 controls).
Testicular atrophy was noted in one control, one 1000 ppm male and two
high dose males. Testicular degeneration was observed in one control,
one 1000 ppm male and in three 5000 ppm males. The two animals with
small prostate noted at necropsy, both had testes weights below the mean
for the 5000 ppm group. The mean testes weight in the 5000 ppm group was
19.068 grams while the animals with the small prostate weights had
testes weights of 18.22 and 17.28 grams. In addition, these same two
animals were two of the three 5000 ppm males with testicular
degeneration. Other organ weight changes were also observed but without
clear dose-response relationships.

**The NOAEL is 1000 ppm (equivalent to 27.5/28.3 mg/kg/day in
males/females). The LOAEL was 5000 ppm (equivalent to 152.6/148.5
mg/kg/day in males/females, respectively) based on findings of hemolytic
anemia, reduced body weight gain in males and increased serum alkaline
phosphatase levels in both males and females.**

This study is classified as **acceptable/guideline** and it satisfies
the guideline requirement (OPPTS 870.4100b, OECD 452) for a chronic oral
toxicity study in dogs. A number of deficiencies were apparent in the
study but most are minor and do not impact upon acceptability of this
study.

**A.3.5 Carcinogenicity**

**870.4200a Carcinogenicity Study - rat**

**870.4200b or 83-2. Carcinogenicity (feeding) -- Mouse**

There are no carcinogenicity studies for sulfometuron methyl since
sulfometuron methyl has no food or feed tolerances and chronic exposure
to this pesticide is unlikely, therefore, such studies are not required.

[]{.mark}

**A.3.6 Mutagenicity**

**Gene Mutation**

[]{.mark}

+----------+----------+----------------------+-------------------------+
| Gene     | Sal      | 00078792 (1979)      | No mutagenic activity   |
| Mutation | monella/ | Acceptable/guideline | for all strains of      |
|          | M        | in strains TA 1535,  | bacteria tested.        |
|          | icrosome | TA 1537, TA 98 and   |                         |
|          | assay    | TA 100 in the        |                         |
|          |          | presence or absence  |                         |
|          |          | of activation.       |                         |
+----------+----------+----------------------+-------------------------+
|          | Chinese  | 00078793 (1981)      | No mutagenic activity   |
|          | Hamster  |                      | with or without         |
|          | Ovary    | Acceptable/guideline | activation.             |
|          |          |                      |                         |
|          |          | CHO cell line was    |                         |
|          |          | used to detect       |                         |
|          |          | mutations for HGPRT  |                         |
+----------+----------+----------------------+-------------------------+

[]{.mark}

**Cytogenetics**

[]{.mark}

+----------+----------+----------------------+-------------------------+
| Ch       | Chinese  | 00146846 (1981)      | No increase in          |
| romosome | Hamster  |                      | chromosome damage and   |
| ab       | Ovary in | Acceptable/guideline | aberrations.            |
| erration | vitro    |                      |                         |
|          | cyt      | CHO in vitro assay   |                         |
|          | ogenetic | with and without     |                         |
|          | assay    | activation           |                         |
+----------+----------+----------------------+-------------------------+

[]{.mark}

**Other Genotoxicity**

[]{.mark}

+----------+----------+----------------------+-------------------------+
| Un-s     | Uns      | 00146847 (1983)      | No induction of UDS was |
| cheduled | cheduled |                      | observed.               |
| DNA      | DNA      | Acceptable/guideline |                         |
| s        | s        |                      |                         |
| ynthesis | ynthesis |                      |                         |
|          | in rat   |                      |                         |
|          | hep      |                      |                         |
|          | atocytes |                      |                         |
|          | *in      |                      |                         |
|          | vitro*   |                      |                         |
+----------+----------+----------------------+-------------------------+

[]{.mark}

[]{.mark}

**A.3.7 Neurotoxicity**

**870.6100 Delayed Neurotoxicity Study -- Hen**

**870.6200 Acute Neurotoxicity Screening Battery**

**870.6200 Subchronic Neurotoxicity Screening Battery**

**870.6300 Developmental Neurotoxicity Study**

[]{.mark}

Neurotoxicity testing is not required as there are no food or feed
tolerances and no indications of neurotoxicity in any available studies.

[]{.mark}

**A.3.8 Metabolism**

**870.7485 Metabolism - Rat**

**870.7600 Dermal Absorption -- Rat**

No dermal absorption data are available in the database.

[]{.mark}

**A.3.9 Special/Other Studies.**

[]{.mark}

Available data do not suggest the need for any special studies.

[]{.mark}

**A.4 References (in MRID No. order)**

> 00071412\. Dashiell, O.L.; Henry, J.E. (1980) Eye Irritation in
> Rabbits, Haskell Laboratory Report No. 963-80. E.I du Pont de Nemours,
> Wilmington, Del.;CDL:244195-N. Unpublished.
>
> 00078792\. Taylor, J.D. (1979) Mutagenic Activity in the Salmonella
> Microsome Assay: Haskell Laboratory Report No. 271-79. E.I. du Pont de
> Nemours & Co., Wilmington, Del.; CDL:245515-K. Unpublished.
>
> 00078793\. Krahn, D.F.; Fitzpatrick, K. (1981) Chinese Hamster Ovary
> Cell Assay for Mutagenicity; Haskell Laboratory Report No. 1074-80. E.
> I. du Pont de Nemours & Co., Wilmington, Del.; CDL:245515-L.
> Unpublished.
>
> 00078796\. Lu, M.H. (1981) Teratogenicity Study by Diet in the Rat
> with Benzoic acid, 2-(((((4,6-dimethyl-2-pyrimidinyl) amino)
> carbonyl)-amino)sulfonyl)-methyl ester: Haskell Laboratory Report No.
> 316-81. E.I. du Pont de Nemours & Co., Wilmington, Del.; CDL:245515-O.
> Unpublished.
>
> 00078798\. Serota, D. G.; Fieser, S.; Durloo, R.S.; et al (1981)
> Teratology Study in Rabbits: H-13647-02: Benzoic Acid,
> 2-(((((4,6-dimethyl ester: Project No. 201-555; HLO-331-81. Hazleton
> Laboratories America, Inc., E.I. du Pont de Nemours & Co., Wilmington,
> Del.; CDL:245515-Q. Unpublished.
>
> 00126714\. Dashiell, O.; Hinckle, L. (1983) Subacute Dermal Toxicity
> (21-days) in Rabbits: Haskell Laboratory Report No. 792-82. E.I du
> Pont de Nemours & Co., Wilmington, DE; CDL:249865-A. Unpublished.
>
> 00129051\. Wood, C.; O'Neal, F. (1983) One-year Feeding Study in Dogs
> with Benzoic Acid, 2-(((((4,6-dimethyl-2-pyrimidinyl)-amin0)carbonyl)
> amino)sulfonyl)-Methyl Ester INT-5648: Haskell Laboratory Report No.
> 482-82. E.I du Pont de Nemours & Co., Inc., Wilmington, DE;
> CDL:250590-A, Unpublished.
>
> 00146846\. Galloway, S. (1981) Mutagenicity Evaluation of H#13,647-03
> in an *in vitro* Cytogenetic Assay Measuring Chromosome Aberration
> Frequencies in Chinese Hamster Ovary (CHO) Cells: (Benzoic Acid,
> 2-((((4,6-dimethyl-2-pyrimidinyl) amino)
> carbonyl)amino)sulfonyl-methyl ester): Project No. 20990. Litton
> Bionetics, Inc. Unpublished.
>
> 00146847\. Ford, L. (1982) Unscheduled DNA Synthesis/Rat Hepatocytes
> in vitro:(Benzoic Acid,
> 2-((((4,6-dimethyl-2-pyrimidinyl)amino)carbonyl)amino)-sulfonyl)-Methyl
> Ester): Haskell Laboratory Report No. 769-82. E.I du Pont de Nemours
> and Co., Unpublished.
>
> 41672808\. Sarver, J. (1990) Primary Dermal Irritation Study with INT
> 5648-40 in Rabbits: Lab Project Number: 137-90: 4581-804. Haskell
> Laboratory. Unpublished.
>
> 43089201\. Sarver, J. (1990) Oral LD50 Test with INT-5648-11 in Male
> and Female Rats: Lab Project Number: 0581-886: HLR 870-80. E.I. du
> Pont de Nemours and Co. Unpublished.
>
> 43089202\. Sarver,J. (1990) Acute Skin Absorption LD50 with
> INT-5648-13 in Male and Female Rabbits: Lab Project Number
> 0581-907:HLR-1078-80. E.I du Pont de Nemours and Co. Unpublished.
>
> 43089203\. O'Neill, A. (1990) Acute Inhalation Toxicity Study with
> INT-5648-18 in Rats: Lab Project Number: 0581-944: HLR-657-82. E.I. du
> Pont de Nemours and Co. Unpublished.
>
> 43089204\. Sarver, J. (1990) Primary skin Irritation and Sensitization
> Test with INT-5548-03 on Guinea Pigs: Lab Project Number : 0581-790:
> HLR 232-79. E.I du Pont de Nemours and Co. Unpublished.

[]{#__RefHeading___Toc185681409 .anchor}**Appendix B: EPA Review of
Human Research - Studies Reviewed for Ethical Conduct**

The PHED Task Force, 1995. The Pesticide Handlers Exposure Database,
Version 1.1. Task Force members Health Canada, U.S. Environmental
Protection Agency, and the National Agricultural Chemicals Association,
released February, 1995.