### 1 UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON D.C., 20460



### PC C odes : 123009
DP B arcode : 425608
D ate : August 26 , 2015
MEMORANDUM

SUBJECT: Problem Formulation for the Ecological Risk and Drinking Water Exposure
Assessments to b e Conducted For the Registration Review for Topramezone

To: Kevin Costello, Chief Jose Gayoso, Chemical Review Manager Risk Management and Implementation Branch 2 Pesticide Re

- evaluation Division (7508P)

FROM: Rochelle F. H. Bohaty, Ph.D., Chemist Tanja Crk

, M.A.

, Biologist Environmental Risk Branch 3 Environmental Fate and Effects Division (7507P)

THROUGH: Dana Spatz, Branch Chief Environmental Risk Branch 3 Environmental Fate and Effects Division (7507P)

PEER REVIEW: Rosanna Louie

- Juzwiak, RAPL Environmental Risk Branch 3 Environmental Fate and Effects Division (7507P)

This memo transmits the Problem Formulation for the e cological risk and d rinking w a ter

e xposure a ssessments to be c onducted for the Registration Review for t opramezone.

### 2 

# Contents

I. Executive Summary

................................ ................................ ................................ ........................ 3
II. Introduction

................................ ................................ ................................ ................................ .. 5
1. Previous Ecological Risk Assessments

................................ ................................ ............................ 5
2. Drinking Water Exposure Assessments

................................ ................................ .......................... 7
3. Clean Water Act Programs

................................ ................................ ................................ ............. 8
III. Stressor Source and Distrib ution

................................ ................................ ................................ .... 8
A. Description of Stressors

................................ ................................ ................................ ................. 8
B. Mechanism of Action

................................ ................................ ................................ ..................... 9
C. Ove rview of Pesticide Usage

................................ ................................ ................................ .......... 9
1. Label Uncertainties

................................ ................................ ................................ ....................... 10
A. Environmental Fate and Transport

................................ ................................ .............................. 14
IV. Receptors

................................ ................................ ................................ .............................. 21
A. Ecological Incidents

................................ ................................ ................................ ...................... 25
B. E xposure Pathways of Concern

................................ ................................ ................................ .... 26
V. Analysis Plan

................................ ................................ ................................ ................................ 26
A. Ecological Risk Assessment

................................ ................................ ................................ .......... 26
1. Stressors of Concern

................................ ................................ ................................ .................... 26
2. M easures of Exposure

................................ ................................ ................................ .................. 27
3. Measure of Effects

................................ ................................ ................................ ....................... 27
4. Integration of Exposure and Effects

................................ ................................ ............................. 27
5. Endangered Species Assessments

................................ ................................ ................................ 28
6. Endocrine Disruptor Screening Program

................................ ................................ ...................... 28
B. Drinking Water

................................ ................................ ................................ ............................. 28
VI. Preliminary Identification of Data Gaps

................................ ................................ .................. 29
A. Environmental Fate

................................ ................................ ................................ ...................... 29
B. Eco logical Effects

................................ ................................ ................................ .......................... 30
VII. References (general) (to be completed during review)

................................ ............................ 36
APPENDIX A. BIBLIOGRAPHY

................................ ................................ ................................ ............ 37
APPENDIX B. ADDITIONAL ENVIRONMENTAL FATE DATE FOR TOPRAMEZONE AND ITS
TRANSFORMATION PRODUCTS

................................ ................................ ................................ ........ 40
APPENDIX C. SIP ANALYSIS RESULTS

................................ ................................ ................................ 42
APPENDIX D. STIR ANALYSIS RESULTS

................................ ................................ ............................... 43

### 3 

## I. EXECUTIVE S UMMARY

The Environmental Fate and Effects Division (EFED) has completed the preliminary problem formulation (attached) for the ecological risk and drinking water exposure assessments to be conducted as part of the Registration Review of the systemic herbicide top ramezone (PC Code 123009). This document is intended to provide an overview of what is currently known regarding the environmental fate and ecological effects associated with topramezone and its degradation products, and outlines uncertainties regarding at tributes of the parent compound and its transformation products. It describes the preliminary ecological risk hypothesis and the processes that will be used during the completion of the preliminary ecological risk assessment in support of Registration Revi ew. Uncertainties unique to the risk assessment of topramezone are also discussed.

A bibliography that includes the study classification for all of the studies that have been submitted to support the registration of topramezone is included in APPENDIX A

. EFED recommends requesting the following additional data to better understand the environmental fate and ecological effects to support the current registrations of topramezone :

• The analytical soil method (LOQ = 0.001 mg/kg; 0.002 lb a.i. /A) is not adequa te to detect topramezone at concentrations equal to the level of concern (EC 05 

### 0.0000102 lb a.i. /A) for terrestrial plants (vegetative vigor). Based on the level of concern, a soil method with a limit of quantification of 5.1 x 10

- 6 

### mg/kg is needed.

• The analyti cal water method is adequate; however, the validations for the water methods ( MRIDs 48600417, 48837001 ) were conducted under the supervision of the same study director

. T herefore, these submissions do not have a supporting independent laboratory val idation.

Guidance recommends testing on four of the most sensitive nonvascular organisms. Three are acceptable and the fourth (MRID 45902332) on Navicula pelliculosa was deemed invalid because it was not possible to differentiate whether the reduction in diatom growth was due to topramezone, or from a reduction in pH

. Multiple incident reports have involved topramezone and plant species.

• An a lgal toxicity study (OCSPP 850.4500 ) on freshwater diatom Navicula pelliculosa using topramezone is needed.

Topramezone use was previous ly identified as posing a risk concern to birds based on chronic exposure

. In addition, the toxicity of topramezone on an acute basis to birds was uncertain due to lack of data (e.g., passerine data not used at time of risk asse ssment

– study was deemed invalid).

• An a vian oral acute toxicity study (OCSPP 850.2100) on passerine using topramezone is needed to resolve this uncertainty.

• A n a vian reproduction study (OCSPP 850.2300) on mallard using topramezone is needed.

T hough previous risk assessments did not identify honey bee risk concern, the conclusions are based solely on acute oral and contact toxicity tests for adults. T he full Tier I suite of honey bee data is not available but is needed for parent topramezone (TGAI, un less otherwise noted below). Tier 2 test ing is contingent on results of T ier 1 tests and screening level residues. Tier 3 testing is contingent on results of earlier tiers of testing.

### 4 • A h oney bee larvae acute oral study (N on

- guideline /OECD TG237, Tier 1)

.

• A honey bee larvae chronic oral toxicity study (Non

- guideline, Tier 1).

• A h oney bee adult chronic oral toxicity study ( Non

- guideline, Tier 1)

.

• Semi

- field testing for pollinators using TEP ( Non

- guideline / OECD 75, Tier 2)

• Field trial of residues in poll en and nectar using TEP ( Non

- guideline, Tier 2)

• Field testing for pollinators using TEP ( OCSPP 850.3040

, Tier 3)

### 5 

## II. INTRODUCTION

Conclusions of the previous assessments are summarized in Table II

. 1 and additional details are provided in the subsections below.

Table II

. 1

. Summary of Previous Risk Concerns a 

### Identified for Topramezone

Exposure Basis Birds Mammals Terrestrial Plants Terr.
Inverts. (honey
bee hazard) Fish Aquatic
Inverts Aquatic Plants Mobile Persistence Degradates of Concern

Acute U b No Yes No c No No Yes Yes Yes M670H05, M670H01,
M670H10 Chronic Yes No Yes Yes

a. At least one LOC has been exceeded in previous assessments
b. U = uncertain due to lack of data (e.g., passerine data not used at time of risk assessment

– study was deemed invalid )

c. The conclusion is based on acute contact and oral adult honey bee data; the full Tier I suite of data is not available.



### 1. Previous Ecological Risk Assessments

Four previous ecological risk assessments have been completed for the regist ration of topramezone for use on agricultural crops and non

- cropped areas

. Conclusions of the previous assessments are
summarized in Table II

. 2 and Table II

. 3

. The only residue of concern identified in these assessments was topramezone given that l imited toxicity data are available for environmental transformation products of topramezone

. Available data (duckweed) on degradate M670H05 suggests reduced toxicity relative to the parent. Note that yearly application rates previously assessed do not reflect yearly application rates

current ly permitted on labels because the label s describe applications on a seasonal basis ; therefore, for

some use sites multiple crop seasons are possible and for these use sites the estimated environmental concentrations (EECs) may have been underestimated.

Table II

. 2

. Summary of Previous Risk Assessments Conducted on Topramezone

Use Reference /

Year Completed Maximum Application Rate Assessed (lb a.i./A) Conclusions

Corn a D290065 /
2005 0.022 (single, seasonal, annual aerial and ground ) Risk was identified for a quatic plants and terrestrial plants . However, minimal risk was associated with bird, mammal, fish, reptile, amphibian, and
invertebrate

Non

- cropped
Areas b D352689 /
2009 0.089 c (single, seasonal, annual aerial and ground ) Risk was identified for a quatic plants and terrestrial plants

.

Turf Grass d D397476 /
2012 0.089 (single, seasonal, annual ground and spot

treatment ) Risk was identified for a quatic plants and terrestrial plants

.

### 6 a. See footnote 1 ; new chemical registration is under BAS 670 336 SC Post

- Emergent Corn Herbicide end use product label (29.7% a.i.)
b. See footnote 2 ; new use registration is under end use label Topramezone 2.8 SC (29.7% a.i.) for pre

emergence and post

- emergence weed control

.
c. In this assessment the definition of ‘season’ was unclear. The label states not to apply more than 0.089 lbs a.i./A of Topramezone 2.8 SC during the growing season. For the analysis, one growing season per year was
assumed for the assessed uses.
d. See footnote 3 ; new use registration is under the end use label Topramezone 2.8 SC (EPA Reg No. 7969

- 281 ) for post

- emergence weed control



### Table II

. 3 . Ri sk Conclusions from Aquatic Use Assessment (D400305 /2013 ) a,b



### Application type Risk Assessment type Application Rate Conclusions

Foliar spray (aerial and ground) Terrestrial and aquatic 0.35 lb a.i./A Potential risk to birds (chronic basis),

non

- target terrestrial plants, and vascular aquatic plants.

Direct in

- water Aquatic 0.05 mg a.i./L Potential risk to estuarine/marine invertebrates (chronic basis), freshwater fish (chronic basis), and vascular aquatic plants. Irrigation water (on food crops) Terrestrial plant 1.0 μ g/L c Potential risk to non

- target terrestrial plants.

a See footnote 7; t he new use registration is under end use label Oasis® Aquatic Herbicide (EPA Reg. no.
7969

- 339 29.7% a.i.) for management of vegetation

b The assessment was tripartite to account for multiple application rates and use areas.

c The lowest labeled concentration of topramezone residues that can remain in irrigation water before use on hydroponic crops or ornamentals (nonfood). Other specific labeled uses permit higher residues in irrigation water: e.g. , corn (max 25 μ g/L) and turf (max 5 μ g/L).

1 grain, seed, popcorn, and sweet corn

2 Non

- cropland areas include Christmas tree, conifer, and hardwood plantations; field grown ornamentals; non

cropland areas such as railroad, utilities, highway, pipeline rights

- of

- way; highway guardrails, delineators, sign posts, utility substations, petrol eum tank farms, pumping installations, farmyards, around farm buildings, fence rows, storage areas, airports, non

- irrigation ditch banks, wildlife openings, and areas grazed or cut for hay.

3 Turf grass includes residential (spot spray only) and nonresid ential turf grass including: airports, athletic fields, cemeteries, golf courses, grounds or lawns around residential and commercial establishments, houses of worship, military and other institutions, single/multifamily dwellings, parks, picnic grounds, ro adsides, schools, and sod farms

.

### 7 

### 2. Drinking Water Exposure Assessments
Several drinking water assessments (DWA) have been completed for topramezone including for use on

corn 1 

### ( D314642 4 

### ) , non

- cropped areas 2 

### ( D356497 5 

### ) , turf grass 3 

### (D388368 6 

### ) and aquatic environments 7 

### ( D408687, D401166 8 

### )

. The only residue of concern considered in these drinking water assessments was topramezone. The highest estimated drinking water concentrations (EDWCs) were reported for direct aquatic applications. According to product labels, f or water bodies with functi onal potable water intakes the topramezone concentration cannot exceed 45 ppb

.

Table II

. 4 . Summary of Previous Drinking Water Assessments

Use Reference Models
Used Estimated Surface Water
Concentrations (μg/L) a Estimated Groundwater
Concentrations b (μg/L)

1

- in

- 10 year Peak 1

- in

- 10 year Annual Mean 30 Year
Mean Peak Post Breakthrough Average

Corn a D314642 PRZM

EXAMS,
SCI

- GROW 0.77 0.14 0.07 0.0671

Non

cropped
Areas b D356497 PRZM

EXAMS,
SCI

- GROW 5.28 2.0 1.02 0.0671

Turf Grass c D388368 PRZM

EXAMS,
SCI

- GROW 1.36 0 .69 0.38 0.271

Terrestrial

Sites d D408687,
D401166 PRZM

EXAMS,
PRZM

- GW 31.2 12.5 7.2
15.4 11.4 Aquatic

Sites e n/a 45

a. See footnote 1

. b. See footnote 2

. c. See footnote 3

. d. Terrestrial use sites were r emodeled when the new use of aquatic use sites were assessed.

e. See footnote 7.

4 Wolf, J., Termers, S., Topramezone (BAS 670H) Herbicide CAS Name, [3

- (4,5

- Dihydro

- 3

- isoxazolyl)

- 2

- methyl

- 4

- (methylsulfonyl)phenyl](5

- hydroxy

- 1

- methyl

- 1H

- pyrazol

- 4

- yl) methanone CAS Registry Number, 210631

- 68

- 8 Tier II Dri nking Water Assessment March 18 , 20 05 (DP Barcode: 388368)

5 Hetrick, J., Corbin, M

. Topramezone (BAS 670H) Herbicide CAS Name, [3

- (4,5

- Dihydro

- 3

- isoxazolyl)

- 2

- methyl

- 4

- (methylsulfonyl)phenyl](5

- hydroxy

- 1

- methyl

- 1H

- pyrazol

- 4

- yl) methanone CAS Registry Number, 210631

- 68

- 8 Tier I and II Drinking Water Assessment September
, 29 , 2008 (DP Barcode: 356497 )

6 Hetrick, J., Spatz, D. Drinking Water Assessment to Support Topramezone Use on Golf Courses, Sod Farms, and Residential Lawns November, 14, 2011 (DP Barc ode: 388368)

7 V egetation in ponds, lakes, reservoirs, marshes, wetlands, bayous, drainage ditches, non

- irrigation and dewatered irrigation canals, and slow

- moving or quiescent bodies of water including vegetation control on shoreline and riparian areas within or adjacent to these and other aquatic sites.

8 Wolf, J., Drinking Water Exposure Assessment for a Proposed Increase of the maximum use rate of Topramezone Frequency Herbicide (EPA Reg. No. 7969

- 281) for non

- cropland uses, and Proposed New Use for Direct Applications to Aquatic Environments (Oasis Aquatic Herbicide, EPA File Symbol No. 7969

- GGO) January, 29, 2013 , (DP Barcodes: 408687; 401166)

### 8 

### 3. Clean Water Act Programs

Topramezone has not been identified as a cause of impairment for any water bodies listed as impaired under section 303(d) of the Clean Water Act. 9 

### No Total Maximum Daily Load (TMDL) criteria have been developed for either compound. 10 

### The EPA invites submission of water quality data for this pesticide. To the extent possible, data should conform to the quality standards in Appendix A of the OPP Standa rd Operating Procedure: Inclusion of Impaired Water Body and Other Water Quality Data in OPP’s Registration Review Risk Assessment and Management Process 11 

### in order to ensure the data can be used quantitatively or qualitatively in pesticide risk assessments.

Aquatic benchmarks have been established for topramezone and are available online. 12 

### Any data submitted or otherwise located as part of the registratio n review process may be used to update aquatic life benchmarks if applicable.



## III. STRESSOR SOURCE AND DISTRIBUTION

A. Description of Stressors

The chemical structure of topramezone along with the chemical identification and select physical

chemical properties are provided in Table III

. 3

. In addition to the technical grade products (5481

- 523 and 7969

- 261), there are five topramezone registered end

- use products (5481

- 524, 7969

- 327, 7969

- 281,
7969

- 262 and 7969

- 339. None of these products contain other active ingredients. Environmental t ransformation products of topramezone include M670H01, M670H10, M670H11,
M670H12 and M670H05 ( additional information on these transformation products is included in the Environmental Fate Section of this document as well as in Appendix B ; stressors of concern are highlighted in Table II.1. )

.

9 http://iaspub.epa.gov/tmdl_waters10/attains_nation_cy.cause_detail_303d?p_cause_group_id=885

10 http://iaspub.epa.gov/tmdl_waters10/attains_nation.tmdl_pollutant_detail?p_pollutant_group_id=885&p_polluta nt_group_name=PESTICIDES

11 http://www.epa.gov/oppsrrd1/registration_review/water_quality_sop.htm

12 http://www.epa.gov/oppefed1/ecorisk_ders/aquatic_life_benchmark.htm

### 9 Table III

. 1

. Chemical Identification and Physical Chemical Properties of Topram e zone

Common Chemical Name Topram e zone
Company Code BAS F 670H
BAS 670H

Chemical Name 3

- (4,5

- Dihydro

- 3

- isoxazolyl)

- 2

- methyl

- 4

- (methylsulfonyl) phenyl](5

- hydroxy

- 1

- methyl

- 1H

- pyrazol

- 4

- yl) methanone CAS Registry Number 210631

- 68

- 8

Chemical Structure


### S O

O O

N O

N N OH

Molecular Formula C 16 H 17 N 3 0 5 S
SMILES NOTATION C1=N[N](C(=C1C(C2=CC=C(C(=C2C)C3=NOCC3)[S](=O)(=O)C)=O)O)C Molecular Mass (g/mol) 363.39 Vapor Pressure (25 °C) 7.3 x 10

- 13 torr
Water Solubility (g/L;
25 °C) pH 5: 0.98 pH 7: 15 pH 9 23.4 Henry’s Law Constant 2.3 x 10

- 17

Log K ow pH 4:

- 0.81 pH 7:

- 1.52 pH 9:

- 2.34 pKa 4.06



### B. Mechanism of Action

Topramezone belongs to the phenyl pyrazolyl ketone chemical family of herbicides. 13 

### Its mode of herbicidal action is inhibition of carotenoid biosynthesis by inhibiting the 4

- hydroxyphenyl

- pyruvate

dioxygenase enzyme (4

- HPPD) in the chlorophyll ultimately leading to breakdown of the chloroplast pathway. This mode of action is shared with isoxaflutole (cyclopropylisoxazole family) and mesotrione (a triketone belonging to the benzoylcyclohexanedione family. 14



### C. Overview of Pesticide Usage

Topramezone is a broad

- spectrum systemic pre

- and post

- emergence herbicide used to control or suppress broadleaf and certain grass weeds. According to the Biological and Economic Analysis Division’s (BEAD) Chemical Profile (BCP) , topramezone is the only py razolone herbicide in the U.S., a type of HPPD enzyme inhibitor.

Topramezone was first registered in the United States in 2005. Topramezone is currently registered for

use on corn 1



### , non

- cropped areas 2



### , turf grass 3 

### , and aquatic use sites 7 

### . All products are formulated as emulsifiable or soluble concentrate that may be applied as a liquid spray . Application types include broadcast (aerial and ground), shoreline treatment (aerial and ground), water treatment (subsurface and surface; aerial and ground), ground spot treatment, ground band treatment, and ground directed

spray. Based on current labels, the maximum single application rate ranges from 0.022 to 0.35 pounds of active ingredient per acre (lb a.i./acre) and up to four applications per year for some uses. The highest

13 http://www.plantprotection.org/HRAC/MOA.html

14 http://www.hclrss.demon.co.uMclassqesticides.html

### 10 annual applicat ion rates generally are found in the non

- agricultural and aquatic uses. A complete list of all current topramezone uses and how EFED currently understands the uses is presented in Table III

. 2

.

Based on the BCP for Registration Review report, between 2006

- 2013, the agricultural uses with the highest usage (in pounds a.i. applied per year) are field and sweet corn with 19,000 lb a.i. average pounds applied annually to 1.3 million acres. Approximately 93% of total pounds of topramezone applied was to field corn; 7% to sweet corn. According to the BEAD Screening Level Usage Analysis (SLUA) 15 

### , between 2004

- 2012, the average percent c rop treated (PCT) for field corn was <2.5% and 15% for sweet corn; the average annual pounds a.i. applied was 10,000 lb a.i. to field corn and 1,000 lb a.i. to

sweet corn

. No usage data are available for non

- agricultural use sites including turf grass, non

- cropped areas or aquatic use sites.



### 1. Label Uncertainties



### a) Terrestrial Uses

For some terrestrial uses, the number of applications of topramezone that can be applied per calendar year or the maximum annual application rate for a given use is not explicitly stated on many of the current labels. See Table III

. 2 for specifics. Assumptions that will be made in absence of label clarifications are provided.



### b) Aquatic Uses

In addition to the uncertainties listed for terrestrial uses there are additional u ncertainties associated with aquatic uses. These uncertainties are listed below ; further details of aquatic use label uncertainties

are provided in the aquatic use assessment (D400305; USEPA 2013).

• There is no defined maximum duration of maintaining som e concentration of topramezone in the water body. The current label language is vague and states to ‘retreat the water to maintain a sufficient concentration for a minimum of 60 days or until satisfactory weed cont rol is achieved.

• No maximum depth is state d on the label

. It is possible the water bodies may become stratified; therefore, the concentration of topramezone based on total volume may result in a much higher
concentration in a given layer if th or ough mixing is not observed.

• The label indicates a m aximum rate of 62 fl oz/acre

- ft (1.35 lb a.i./acre

- ft). This would suggest a potential for periods of time where concentrations may temporarily exceed the target concentration during an application (i.e., > 0.05 mg a.i./L) upon initial and subsequent appli cations of topramezone until dilution (i.e., achieving the desired concentration).

• The treatment of flowing water is dependent on flow rate and length of time that the application occurs. The label doesn’t provide information on minimum or maximum flow rates that can be treated. Potential Concentration Spikes: The maximum concentration permitted for the direct in

- water uses (single or multiple applications) per year, per season, or per tre atment period should also be clarified in the current label (Oasis® aquatic herbicide, EPA Reg. No. 7969

- GGO).

15 LaVerne, D., Topramezone Label Use Report Package in Support of Registration Review

, J anuary 20, 2015

### 11 Table III

. 2

. Topramezone Label SummaryCrop/Site Timing; Application Type Method/ Equipment Maximum Single Application Rate by Formulation Maximum Application Rate Maximum Application

NumberPHI (days)dMRI (days)dGeographic Restrictions

Comments

( lb/A) a Per
Year b lb/A Per
CC b,c
lb /A Per
Year Per
CC c

AGRICULTURAL FALLOW/IDLELAND /
CONSERVATION RESERVE NS Broadcast/ Aerial,
Ground 0.0219 0.0219 NA 1 NA NA 14 NR None

AQUATIC AREAS/WATER Post

emergence Broadcast ( floating, emergent, shoreline)/ Aerial,
Ground 0.3501 NS NA [1] NA e NA NS NR None

Broadcast (surface)/ Aerial,
Ground 0.3501 NS NA [1] NA NA 60 NR None

Single In

- water

(Pond, Lake Reservoir) 30

- 50 μg /L (0.03

- 0.05 mg/L) 50 μg /L d

0.05 mg/L NS [1] c NA NA NS NR None

Split/Multiple In

water (Pond, Lake Reservoir) 20

- 50 μg /L (0.02

- 0.05 mg/L) 50 μg /L d

0.05 mg/L NS NS c NA NA NS NR None

CHRISTMAS TREE
PLANTATIONS Post

emergence Broadcast, Band, Directed/ Ground 0.0875 0.3501 NA 4 NA NS 30 NR None

Corn Post

emergence Broadcast/ Aerial,
Ground 0.0219 [0.0657] 0.0219 [3] 1 45 NS NR None

### 12Crop/Site Timing; Application Type Method/ Equipment Maximum Single Application Rate by Formulation Maximum Application Rate Maximum Application

NumberPHI (days)dMRI (days)dGeographic Restrictions

Comments

( lb/A) a Per
Year b lb/A Per
CC b,c
lb /A Per
Year Per
CC c

FOREST TREES (HARDWOODS, BROADLEAF TREES) Post transplant Broadcast/ Aerial,
Ground 0.0875 NS NS NS NS NA NS NR None

NONAGRICULTURAL
UNCULTIVATED AREAS/SOILS Post

emergence Broadcast/ Aerial,
Ground 0.3501 0.3501 NS [1] NA NA NS NR None

NURSERY STOCK Pre and Post

emergence Direct Spray/
Ground 0.0875 0.3501 NA 4 NA NA NS NR None

ORNAMENTAL LAWNS
AND TURF Post

emergence Broadcast/ Aerial,
Ground 0.0875 0.3501 NA 4 NA NS NS NR None

ORNAMENTAL SOD FARM (TURF) Post

emergence Broadcast/ Ground 0.0438 0.0875 NA 4 NA NS NS NR None

RECREATION AREA
LAWNS Post

emergence Spot Treatment/
Ground 0.0438 0.0875 NA 4 NA NS NS NR None

RECREATION AREA
LAWNS Post

emergence Spot Treatment/
Ground 0.0438 0.0875 NA 2 NA NS NS NR None

a. Reported as per crop cycle or per season
b. PHI

– Preharvest Interval; REI

– Reentry Interval; MRI

– Minimum Retreatment Interval

c. Per label, ‘use in compliance with Best Management Practices, which are developed to maintain and/or monitor target concentra tions over large areas, ensure accurate applications, and maximize treatment performance, minimize resistance development, and to m onitor concentrations in water used for

### 13Crop/Site Timing; Application Type Method/ Equipment Maximum Single Application Rate by Formulation Maximum Application Rate Maximum Application

NumberPHI (days)dMRI (days)dGeographic Restrictions

Comments

( lb/A) a Per
Year b lb/A Per
CC b,c
lb /A Per
Year Per
CC c

potential irrigation.’ The label also encourages the BASF Corporation technical specialists be called upon to assist ‘applica tors and resource managers to ensure compatibility with potential uses of the water and man agement objectives. d. There is uncertainty on the maximum number of applications for these uses, which could pertain to a single treatment regimen (lasting at least 60 days for the split/multiple in

- water use only), a growing season, or multiple times a year , but the label does not specify this point.

e. A season is only specified in the case for weed control on shoreline and riparian areas within or adjacent to aquatic sites. No Restrictions (NR); Not Specified (NS); Not Applicable (NA) [ ] are used to define a ssumptions that will be made in absences of label clarification. When information was not specified on the label the maximum number of applications was assumed to be 26 that corresponds to one application every two weeks.

### 14 A. Environmental Fate and Transport

Based on physicochemical properties ( Table III

. 1 ) alone, volatility is not expected to be a major dissipation pathway for topramezone, and topramezone is not expected to bio concentrate

. Environmental fate parameters of topramezone are prese nted in Table III

. 3 and summarized below

.

In summary, t opramezone is persistent and mobile in terrestrial and aquatic environments. Topramezone is stable in sterile solutions at pH 4, 5, 7, and 9 at temperatures ranging from 25 to 50 °C (MRID 45902416) . In natural water, topramezone has a photodegradation half

- life of 144 days (MRID
45902417 ) . Topramezone was stable to photodegradation in sterile buf fered solutions.

A erobic soil metabolism half

- life values ranged from 129 to 305 days in five soils (MRID 45902421) ; however, t opramezone was found to be stable in one soil (MRID 45902419 )

. In soil, t opramezone transforms to M670H05 at concentrations up to 15% of applied and M670H01 at concentrations up to 10% of applied.

Aerobic aquatic metabolism total system (sediment and water) half

- life values for topramezone were 345 and 471 days (MRID 45902423) . M670H01 was the only transformation product observe d but with
concentrations that did not exceed 10 % of applied . I n anaerobic environments, topramezone degr aded with total system half

- life values ranging from 13 to 47 days (MRID s 45902422

, 48600413 )

. I n anaerobic aquatic environments , major transformation products included M670H10 ( 48% of applied ) while
M670H01 , M67 H 011 and M670H12 were observed at concentrations less than 10% of the applied radioactivity depending on the test system

.

Based upon soil organic carbon coefficient (K foc 

### 38

– 297 ; MRID 4590242 5 ) topramezone is considered mobile to moderately mobil e based on FAO mobility classification 16



### . Dissipation of top ramezone in field studies [ terrestrial (MRID 45902426) and aquatic (MRID 48600414 ) ] was generally faster than that observed in the laboratory studies; however, field studies confirm persistence and mobility. No transformation products were observed in the field studies that were not previously identified in laboratory studies.

Several s tudies were submitted without adequate storage stability studies; however, g iven the persistence of topramezone observed in the various laboratory studies except for the anaerobic aquatic metabolism studies topramezone is assumed to be stable during storag e

.

The environmental chemistry method for soil reports the limit of quantification (LOQ) of topram e zone and M670H05 in soil 0.001 ppm [0.001 mg/kg; 1 μg/kg; 0.002 lb/A 17 

### (MRID 45902429)]. The environmental chemistry method for water and sediment reports a LOQ of 0.001 ppm [sediment: 0.001 mg/kg; 1 μg/kg; 0.002 lb a.i. /A 17 

### /water: 1.0 μg/L; 0.0002 lb a.i. /A 18 

### (MRID 48837001)]. A limit of

16 USEPA, 2006. Standardized Soil Mobility Classification Guidance. Memorandum: S. Bradbury, April 21, 2006.

17 LOQ = 0.0 01 m g/kg
0.0 01 mg/kg (s) = [x] kg/ha x 10 6 mg/kg / [0.15 m (depth) x 10 4 m 2 /ha x 1.5 x 10 3 kg(s)/m 3 (density)]
0.0 01 mg/k g(s) = [x] kg/ha x 10 6 mg/kg / 2.25 x 10 6 kg (s)/ha
= 2.25 x 10

- 3 kg/ha = LOQ = 0.0 0 2 lb a.i. /A

18 LOQ = 1.0 μg/L 226,625 lb of water/acre x 1.0 μ g/L /1,000,000,000 = 0.0002 lb /A 0.0002 lb /A = 2.54 x 10

- 4 kg a.e./ha

### 15 detection (LOD) was not established in either study; therefore, the LOD is assumed to be equal to the LOQ. Independent laboratory validation are not available for the water method

. Based on toxicity information presented in Table IV

. 1 and Table IV

. 2 these methods are adequate for detecting topramezon e at concentrations that are equal to the level of concern except for the soil method. The soil method is not adequate to detect topramezone at concentrations equal to the level of concern (EC 05 

### 0.0000102 lb a.i./A) for terrestrial plants (vegetative vigor MRID 49365105 ).

[x] mg/kg (s) = 1.46 x 10

- 5 kg a.e./ha x 10 6 mg/kg / [0.15 m (depth) x 10 4 m 2 /ha x 1.5 x 10 3 kg(s)/m 3 (density)] LOQ 1.1 x 10

- 4 mg/kg (s)
0.0 0011 mg/kg (s) = [x] kg/ha x 10 6 mg/kg / [0.15 m (depth) x 10 4 m 2 /ha x 1.5 x 10 3 kg(s)/m 3 (density)]
0.0 0011 mg/kg(s) = [x] kg/ha x 10 6 mg/kg / 2.25 x 10 6 kg (s)/ha
= 2.48 x 10

- 4 kg/ha = LOQ = 0.0 00 2 lb a.i. /A

### 16 Table III

. 3

. Chemical Properties and Environmental Fate Parameters of Topramezone

Study/
Guideline System Name/
Characteristics Kinetic Model Fitted a Value
and Unit (Fitting Equation) Representative Half

- life
Value

-- Value Used to Derive

Model Input Values (days) b

-- Source/
Classification Comments

DT50 (days) DT90 (days)

Hydrolysis
835.2010 pH 5, 25  ̊C
stable 0 MRID
45902416 acceptable --- pH 7, 25  ̊C pH 9, 25  ̊C

Aqueous Photolysis
835.2240 0.01 M acetate, pH 5 stable

0 MRID
45902417 acceptable --- 0.01 M tris, pH 9 Stable

---

natural NC pond water, pH 7 72.1 144* 239 478* *values transformation at 80% of natural sunlight in spring at 40  ̊ N and reflect s a 12

- hour light

- 12

- hour dark cycle

.

Soil Photolysis
835.2410 sandy loam, pH 6.3 stable 0 MRID
45902418 acceptable There are an insufficient number of sampling intervals; however, the rate of transformation of topramezone in the irritated and dark control sample was similar. Therefore, soil photolysis is not expected to be a significant dissipation process in the
envir onment. Therefore, despite the noted deficiency additional data are unlikely to provided additional information.

Aerobic Soil Metabolism

835.4100 North Carolina Sandy Loam, pH 6.3, 2.6% OM stable 0 MRID
45902419 Reclassified to supplemental The dissipation of topramezone was biphasic with a large amount (up to 65% of the applied material)
of unextracted residues were observed. The extraction procedure
was not considered exhaustive. Based on the profile of the formation of non

- extracted
residu es and the apparent biphasic

### 17 Study/
Guideline System Name/
Characteristics Kinetic Model Fitted a Value
and Unit (Fitting Equation) Representative Half

- life
Value

-- Value Used to Derive

Model Input Values (days) b

-- Source/
Classification Comments

DT50 (days) DT90 (days) dissipation the unextracted residues may be topramezone. Idaho Loam, pH 6.6,
6.3% OM 143 477 202 (DFOP)

MRID
45902421 Reclassified to supplemental Not all transformation products
detected at ≥ 10% of the applied
material were identified. Indiana Silt Loam, pH 6.8, 1.4% OM 152 505 203 (DFOP)

Iowa Loam, pH 6.6,
6.4% OM 305 1013 305 (SFO)

Minnesota Clay Loam, pH 6.0, 7.0% OM 129 429 129 (SFO)

South Dakota Silt Loam, pH 5.9, 4.9% OM 156 519 231 (DFOP)

Anaerobic Soil
Metabolism

835.4200 No data

Aerobic Aquatic Metabolism

835.4300 Ohio water

- loam (Grand River) pH 7.7, 0.9 % OM 269 895 269 (SFO) phenyl

MRID
45902423
47496702 Reclassified to supplemental Up to 18% of the applied radioactivity was associated with unextracted residues. Application rate 0.033 mg/L. A relatively low amount of initial dissipation was observed (up to 25% percent of the applied). Kinetic analysis were completed for two different radiolabels independently and combined. The representative half

life value for the combined radiolabels is t R IORE = 3.71 x10

- 11 days following the NAFTA guidance; however, the SFO t 1/2 = 345 days better reflect the results of the
individual datasets. 475 1579 475 (SFO) pyrazole

### 18 Study/
Guideline System Name/
Characteristics Kinetic Model Fitted a Value
and Unit (Fitting Equation) Representative Half

- life
Value

-- Value Used to Derive

Model Input Values (days) b

-- Source/
Classification Comments

DT50 (days) DT90 (days)

345 1146 345 (SFO)
combined ---

Ohio water

- loam (Homestead Pond) pH 4.9, 5.3 % OM 471 1566 471 (SFO) Rapid dissipation of topram e zone was observed; however, this dissipation was consistent with the formation of unextracted residues. Up to 79% of the applied radioactivity was associated with
unextracted residues were observed. The extraction procedure
was not considered exhaustive. In addition, these results are not consistent with corresponding river water system. Kinetic analysis were completed for the combination of topramez one and the unextracted
residues. The results are consistent with the results obtained for the river water system. The difference
in unextracted residues observed between the two test systems may be a function of the higher organic material noted in the po nd water test system.

Anaerobic

Aquatic Metabolism

834.4400 South Dakota water pH 8.2, organic carbon 15.6 mg/L; sediment pH 7.8, organic matter 8.3% 13 43.1 13 (SFO) MRID
45902422 Supplemental Dissipation of topram e zone was observed; however, there is a large amount of unextracted residues [up to 60%; half

- life of 149 days (SFO) when unextracted residues are considered]. The extraction procedure was not considered exhaustive. In addition, there are noted study defici encies including

### 19 Study/
Guideline System Name/
Characteristics Kinetic Model Fitted a Value
and Unit (Fitting Equation) Representative Half

- life
Value

-- Value Used to Derive

Model Input Values (days) b

-- Source/
Classification Comments

DT50 (days) DT90 (days) variability between replicate samples (not all samples had replicates) and stabilty concerns including sample work up and storage stability.
Florida water pH 8.6, organic sediment pH 7.7, organic matter 0.97% 47 157 47 (SFO)

MRID
48600413 supplemental An exaggerated application rate (26x) was used and may have affected the microbial activity of the water:sediment systems, and thereby influence the rate and route of transformation of topramezone. The sediment extraction procedure ma y not have been adequate to remove all identifiable residues from the
sediments. And, for the sand sediment system, transformation products detected at ≥10% of applied were not identified. Pennsylvania water pH 8.6, organic sediment pH 5.4, organic matter 6.7% 25 84 25 (SFO)

Terrestrial
Field Dissipation
835.6100 Cambridge, Ontario 20.5 1837 912 (DFOP) MRID
45902427 Supplemental T he results are consistent with laboratory data that indicate topramezone is persistent. Results indicate that topramezone may leach through the soil profile. Topramezone was detected in samples down to 15

- 30 cm (279 and 364 days following the second application). Not all transformation products were analyzed. Indiana, bareground, pH 6.3, 1.5% OM Kinetic analyses were not updated 67* MRID
45902426 T he results are consistent with laboratory data that indicate

### 20 Study/
Guideline System Name/
Characteristics Kinetic Model Fitted a Value
and Unit (Fitting Equation) Representative Half

- life
Value

-- Value Used to Derive

Model Input Values (days) b

-- Source/
Classification Comments

DT50 (days) DT90 (days) South Dakota, bareground, pH 7.6,
4.3% OM 185* Supplemental topramezone is persistent. Topramezone was observed to leach through the soil profile. * values were taken from DER. California, bareground, pH 8.2, 0.7% OM 158*

California, cropped plot, pH 8.2, 0.7% OM 29*

Aquatic Field Dissipation
835.6200 Florida, water 79.2 263 79.2 (SFO)

MRID
48600414 Supplemental The stability of topramezone and its transformation products in frozen water and sediment was not adequately determined. An insufficient number of sediment samples were collected per sampling interval and samples may
not have been collected to a sufficient depth. An independent laborator y method validation was
not conducted. Florida, sediment 22.3 130 39.1 (IORE) Indiana, water 23.7 78.6 23.7 (SFO)

Indiana, sediment 4.5 183 55 (IORE)

DT50 and DT90 values were calculated using single first

- order (SFO), double first

- order in parallel (DFOP), or indeterminate

- order equation (IORE). For DFOP, the overall DT50 and DT90 are reported when available. The equations can be found in the docume nt, Standard Operating Procedure for Using the NAFTA Guidance to Calculate Representative Half

- life Values and Characterize Pesticide Degradation, U.S. Environmental Protection Agency, March 23,
2012. The value used to estimate a model input value is the c alculated SFO DT 50 , T IORE , or the 2 nd DT 50 from the DFOP equation. The model chosen is consistent with that recommended using the, Guidance for Evaluating and Calculating Degradation Kinetics in Environmental Media , Health Canada, U.S.
Environmental Prote ction Agency, December 21, 2012. The same model used to estimate the value used to derive a model input, is used to describe the
DT50 and DT90 results.

### 21 

## IV. RECEPTORS

Table IV

. 1 and Table IV

. 2 provide a summary of the terrestrial and aquatic toxicity data, respect ively, and the most sensitive surrogate species tested to characterize the potential acute and chronic ecological effects of topramezone. Table IV

. 3 provides information on the non

- guideline toxicity data available for topramezone.

Table IV

. 1

. Summary of the Most Sensitive Endpoints from Terrestrial Toxicity Studies for Topramezone

Study Type Endpoint Val ue Used in Risk
Assessment Toxicity Classification Study Rating MRID

Rat acute oral LD 50 > 2000 mg /kg

- bw Practically
nontoxic Acceptable (x3) 459021

- 18;

- 19;

- 20

Rat 2

- generation reproduction NOAEC/
LOAEC Parental and offspring toxicity (male) a : 4 / 40 mg/kg

- diet 0.4 / 4.2 mg/kg/day

Reproductive toxicity (male) b : 4000 />4000 mg/kg

- diet
426.8 / >426.8 mg/kg/day --- Acceptable 459022

- 14

Avian acute oral (Bobwhite) LD 50 > 2000 mg ai/kg

- bw
No mortalities Practically
nontoxic Acceptable 459023

- 09

Avian sub

- acute dietary (Mallard) LC 50 > 5080 mg ai/kg

- diet Practically
nontoxic Acceptable 459023

- 11

Avian reproductive

(Mallard) NOAEC /LOAEC <100 / 100 mg ai/kg

- diet --- Supplemental c 459023

- 13

< 66.5 / 66.5 mg

a.i./kg

- diet --- Supplemental d 493651

- 02

Honey bee , adult

acute contact LD 50 >100 μg ai/bee Practically
nontoxic Acceptable 459023

- 25

Terrestrial Plant

– Seedling Emergence I C 25 /
NOAEC 0.042 / 0.015 lb a.i. /acre (monocot);
0.0039 / 0.002 lb a.i./acre (dicot) --- Acceptable e 459023

- 27

> 0.044 / 0.044 lb a.i./acre (monocot )

>0.022 / 0.022 lb a.i./acre ( dicot) (Deg: M670H 05) -- Supplemental f

, for qualitative

use 493651

- 04

### 22 Study Type Endpoint Val ue Used in Risk
Assessment Toxicity Classification Study Rating MRID

Terrestrial Plant

– Vegetative Vigor I C 25 /
NOAEC 0.01 / 0.005 lb a.i./acre (monocot);
0.0001 / [ 0.000009 ] g

lb a.i. /acre (dicot) --- Acceptable e 459023

- 28

0.00 204 / 0.0 0 0 52 lb a.i./acre (monocot)
0.0000867 / [0.0000102] g lb a.i./acre (dicot ) (Parent M670 01H mixed with adjuvant ) -- Supplemental h

, for quantitative

use 493651

- 05

*Values in bold will be used in RQ calculation.

a Parental toxicity is based on decreased body weights and body weight gains in males; increased kidney and thyroid weights, histopathological findings in the eyes, kidney, and thyroid of both sexes. Offspring toxicity is based on decre ased pup weight and body weight gains in the F 2 generation and increased time to preputial separation in the F1
males.

b No treatment

- related effects on reproductive toxicity.

c The most sensitive endpoint is non

- definitive. A NOAEC is undefined given the significant treatment

- related losses in body weight (i.e., hatchling body weight and adult female weight gain) at all treated levels relative to the control.

d The most sensitive endpoint is non

- definitive. A NOAEC is undefined given the significant, trea tment

- related loss in adult male body weight at all treated levels relative to the control.

e Toxicity of topramezone end

- use product (BAS 670 00H, 31% a.i.).

f Test substance is TGAI (as opposed to TEP) topramezone transformation product (BAS M670H 05).

g EC 05 value. The EC 05 is used in place of a NOAEC if a NOAEC value is not established in the study.

h Test substance is TGAI (as opposed to TEP) topramezone mixed with an adjuvant

### 23 Table IV

. 2

. Summary of the Most Sensitive Endpoints from Aquatic Toxicity Studies for Topramezone

Study Endpoint Toxicity Value Toxicity Classification Study Rating MRID

Acute freshwater

fish (Rainbow Trout) LC 50 > 94.6 mg TEP a /L (> 28.38 mg a.i./L) ≤ Slightly toxic Acceptable 459018

- 13

Early life

- stage freshwater fish (Rainbow Trout) NOAEC /
LOAEC 2.93 / 9 .01 mg a.i./L
“F

o ” wet weight, length,
and survival b --- Acceptable 459023

- 21

Chronic life

- cycle freshwater fish (Fathead minnow) NOAEC/
LOAEC < 0.248 c / 0.248 mg a.i./L

F

1 wet weight at 8 weeks post

- hatch -- Acceptable

BAS 670 H 99.2% purity 48600406

Acute freshwater invertebrate (Waterflea) EC 50 > 99 mg TEP d /L (> 29.7 mg a.i./L) ≤ Slightly toxic Acceptable 459018

- 20

Life

- cycle freshwater
invertebrate (Waterflea) NOAEC (21

- day) / LOAEC 48.6 / 97.5 mg a.i./L

--- Supplemental e 459023

- 20

29 / 58 mg a.i./L

-- A cceptable 493651

- 03

Acute estuarine/marine fish (Sheepshead minnow) 96

- hr
LC 50 /
NOAEC > 37 / 37 mg a.i./L No effects Practically non

toxic Acceptable

BAS 670 01H TEP:

30.2% purity 48600410 †

Chronic early life

stage estuarine/marine fish (Sheepshead minnow) NOAEC/
LOAEC 10 / >10 mg a.i./L

No effects -- Acceptable

BAS 670 H 97.5% purity 48600404

Acute estuarine/marine
invertebrate

(Mysid) LC 50 /
NOAEC 1.8 / 0.84 mg a.i./L Mortality Moderately
toxic Acceptable

BAS 670 01H TEP:

30.2% purity 48600412 †

Chronic life

- cycle estuarine/marine
invertebrate

(Mysid) NOAEC/
LOAEC 0.036 / 0.069 mg a.i./L
Juvenile survival -- Supplemental f

BAS 670 01H TEP:

30.2% purity 48600411 †

Aquatic plant, Tier
II

– vascular (Duckweed) EC 50 /
NOAEC 0.0067 / 0.001 mg a.i./L

--- Acceptable 459023

- 29

Aquatic plant, Tier
II

– vascular (Duckweed) EC 50 /
NOAEC 0.36 / 0.0067 mg M670H05/L --- Acceptable g 462427

- 04

Aquatic plant, Tier
II

– vascular (Duckweed) EC 50 /
NOAEC 0.0286 / 0.0023 mg EP/L (0.00858 / 0.00069 mg ai/L) --- Acceptable h 459018

- 21

### 24 Study Endpoint Toxicity Value Toxicity Classification Study Rating MRID

Aquatic plant, Tier

II

– non

- vascular

(Freshwater Green algae; Marine diatom) EC 50 /
NOAEC 19 / 3 mg a.i./L;
49 / 3 mg a.i./L --- Acceptable; Acceptable 459023

- 33;

- 31

10

- day Spiked
Sediment survival of Marine Arthropod ( Leptocheirus plumulosus ) LC 50 / NOAEC/
LOAEC Mean

- measured sediment: 1.06/0.50/0.96 mg a.i./kg
OC

- normalized mean

measured sediment: 48.2/22.7/43.6 mg a.i./kg TOC
Mean

- measured pore water: 2.65/1.23/2.49 mg a.i./kg

Mean

- measured overlying

water: 0.40/0.191/0.350 mg a.i./kg
Survival -- Acceptable

BAS 670 H 98.9% purity 48600407

Prolonged Spiked

Sediment with

Chironomus

riparius EC 50 / NOAEC/
LOAEC TWA sediment: >55.6/55.6 / >55.6 mg a.i./kg TWA pore water: >23.1/23.1/>23.1 mg a.i./L TWA overlying water: >14.5/14.5/>14.5 mg a.i./L No effects -- Supplemental i

BAS 670 H 98.9% purity 48600408

*Values in bold may be used in RQ calculation. For aquatic plants, the EC 50 is used to calculate the non

- listed plant RQ and the NOAEC is used to calculate the listed plant RQ.

† The study was conducted with an end use product containing 30.2% topramezone a.i.

a TEP = Ref No. 375080 (335.6 g/L BAS 670 H; approximately 30% a.i.)

b Endpoints affected: wet weight, length, juvenile survival; abnormalities included decreased growth (reduction of body length) in juveniles

c Response of this endpoint was not dose

- dependent, but reductions at all treatment levels ranged from 10 to 23% lower than weights of negative control fish. Analysis and interpretation of effects on this endpoint were limited by the low replicate number (n=2). Despite this low statistical power, differences from control were detected across the range of reduced weig hts. Given the magnitude of the reductions from control and the detection of a significant reduction at the lowest level, the possibility that the test material was affecting response of this endpoint could not be dismissed; thus, th e NOAEC could not be de fined in this study.

d TEP = Ref No. 375080 (337.7 g/L BAS 670 H; 30% a.i.)

e Dry weights of surviving daphnids were not measured; total length was not reported. Endpoint based on reduced number of live young produced.

f The number of offspring produced pe r female in the negative control is 4.1, which falls below the anticipated optimal level of 8 offspring per female.

g Toxicity of topramezone primary degradate (M670H05, 99.3 % ai)

h Toxicity of topramezone end

- use product (BAS 670 00H, 30% ai)

I The OECD 218 does not meet U.S. EPA guidelines for a chronic life cycle toxicity test with the midge because the test is run through emergence and does not include reproduction endpoints.

### 25 Table IV

. 3

. Summary of the N on
- Guideline Toxicity Endpoints for Topramezone

Study Endpoint Toxicity Value Toxicity Classification Study Rating MRID

Non

- target
Insect (Earthworm) LC 50 /
NOAEC >1000 / 296.3 mg ai/kg dry wt soil Practically
nontoxic Supplemental a,b 459023

- 26

Non

- target
Insect (Earthworm) LC 50 >1000 mg EP/kg dry
wt soil Practically
nontoxic Supplemental a,c 459018

- 19

Non

- target Insect (Carabid beetle) LR 50 d >223 mL/ha (0.07 lb ai/A) Practically
nontoxic Supplemental a,c 459018

- 18

Non

- target
Insect (Lacewing) LR 50 d >225 mL/ha (0.07 lb ai/A) Practically
nontoxic Supplemental a,c 459018

- 17

Non

- target Insect (Predatory mite) LR 50 d >675 mL/ha (0.24 lb ai/A) Practically
nontoxic Supplemental a,c 459018

- 16

Non

- target
Insect (Parasitic wasp) LR 50 d >675 mL/ha (0.24 lb ai/A) Practically
nontoxic Supplemental a,c 459018

- 15

a Not an EPA guideline

b Toxicity of topramezone (95.8 % ai)

c Toxicity of end

- use product (BAS 670 00 H, 31% ai)

d LR 50 is the application rate of compound at which 50% of test organisms die



### A. Ecological Incidents
Three incident databases are available: 1) the Ecological Incident Information System v. 2.1.1 (EIIS), maintained by EFED; 2) the Avian Incident Monitoring System (AIMS), maintained by the American Bird Conservancy; and, 3) the Incident Data System (IDS) maintained by OPP. These databases were searched on June 10, 2015.

The Ecological Incident Information System (EIIS) database was queried for incidents related to topramezone use. Three incidents were reported in the EIIS database, all three with effects to plants (damage or mortality), specifically corn and hay. The incidents occurred in different states: Ohio, Kansas, and Oregon. The certainty index for the dama ge in all 3 incidents to plants was rated as possibly related to exposure to topramezone.

• Incident 1 (I022217

- 028): On July 1, 2010 in Warren County, Ohio 92.1% of 35 acres of corn was damaged from direct broadcast treatment.

• Incident 2 (I021535

- 001): On May 30, 2009 in Brown County, Kansas 108 acres of corn exhibited mortality from direct broadcast treatment.

• Incident 3 (I021950

- 001): On March 10, 2010 in Douglas County, Oregon 1

- 2 acres of hay was damaged from a runoff event from a right

- of

- way.

A quer y of the aggregate Incident System (IDS) on June 10, 2015 reported no incidents.

### 26 The Avian Incident Monitoring System (AIMS), a database administered by the American Bird Conservancy, was queried for topramezone on June 10, 2015 and to date, there were no bird incidents reported.

The absence of documented incidents in these databases does not necessarily mean that such incidents did not occur. Mortality incidents must be seen, reported, investigated, and submitted to the Agency in order to be recorded in the incident databases. In addition, incident reports for non

- target organisms typically provide information only on mortality events and plant damage. Sublethal effects in organisms such as abnormal behavior, reduced growth and/or impaired reproduction are rarely reported, except
f or phytotoxic effects in terrestrial plants.

B. Exposure Pathways of Concern

Based on the use pattern and environmental fate characteristics of this pesticide, the following exposure pathways are expected to be most relevant for determining exposure and poten tial risk to non

- target organisms:

• Direct spray

• Spray drift

• Runoff

• Leaching to ground water followed by irrigation

In addition, terrestrial animals that use treated fields may be exposed to topram e zone from consuming contaminated plants and invertebrates , dermal absorption, and drinking from contaminated puddles. Drinking water exposure pathways were screened using SIP (Screening Imbibition Program) and indicate that drinking from contaminated puddles is a pathway of potential concern for topramezone

. The potential for i nhalation exposure was screened using S TIR (Screening Tool for Inhalation Risk )

. Based on this analysis inhalation is a pathway of low concern (no LOC exceedances are expected)

.
SIP and STIR are described in detail at http://www.epa.gov/oppefed1/models/terrestrial/index.htm and the SIP and STIR model inputs and outputs for topramezone are available in APPENDICES C AND D

, respectively.

While topramezone is expected to be taken up by plants and translocated

, concentrations in nectar and pollen are unknown. Nevertheless, both oral and contact exposure to pollinators is expected to occur as a result of direct sp r ay onto flowering weeds.



## V. ANALYSIS PLAN

A. Ecological Risk Assessment



### 1. Stress ors of Concern

B oth topramezone and environmental transformation products M670H05, M670H01, and M670H10 are considered the stressors of concern. Data on the degradate M670H05 has been submitted for only two sets of species, the aquatic vascular plant duckweed and the terrestrial plants (seedling emergence only). In both instances, the sensitivity of the plants to the transformation products appears to be orders of magnitude less than the sensitivity to the parent. However, little is known about the effect s of the

### 27 other major degradates M670H01 and M670H10. EcoSAR estimates were not informative as the estimates for topramezone do not reasonably compa re with available toxicity data . In absence of additional data

, EFED will use a total toxic residue (TTR) approach

. The TTR approach is ba sed on the assumption that the transformation products are of equal toxic ity to the assessed organisms tested with the parent compound

. The total toxic residues (TTRs) are defined as t opramezone, M670H05, M670H01, and M670H10 for all taxa except plants. For plants, M670H05 is excluded from the TTR because available data indicate that it is orders of magnitude less toxic than topramezone. In addition, the core structure of the parent compound is no t maintained.



### 2. Measures of Exposure

In order to estimate risks of topramezone (and its environmental transformation products) exposure to aquatic and terrestrial organisms, all exposure modeling and resulting risk conclusions will be made based on maximum a pplication rates, application methods, and any mitigation measures specifically indicated on the label. The models that will be used to predict the EECs are discussed on OPP’s model website. 19



### Available monitoring data will be evaluated and considered in a n assessment conducted for Registration
Review.

Exposure to terrestrial animals is estimated using the Terrestrial Residue Exposure (T

- REX) model. Exposure to terrestrial plants is estimated using the TerrPlant model. For terrestrial plants, exposure is b ased on the calculated maximum application rates with assumed exposure from runoff, but not spray drift. A description of t hese models may be found at: http://www.epa.gov/pesticides/scienc e/models_db.htm

.



### 3. Measure of Effects
Ecological effects data are used as measures of direct and indirect effects to biological receptors. Data are typically obtained from registrant

- submitted studies and from literature studies identified by
ECOTOX (USEPA 2014) . The ECOTOX database provides more ecological effects data in an attempt to bridge existing data gaps. ECOTOX is a source for locating single chemical toxicity data and potential chemical mixture toxicity data for aquatic life, terrestrial pl ants, and wildlife. ECOTOX was created and is maintained by the U.S. EPA, Office of Research and Development, and the National Health and Environmental Effects Research Laboratory's Mid

- Continent Ecology Division. Toxicity data presented in
Section IV of t his problem formulation will be used in the quantitative risk assessment. Any additional toxicity data submitted by the registrant , as well as relevant toxicity information found in the open literature

, will also be considered.



### 4. Integration of Exposure and Effects

Exposure and effects will be integrated in an updated risk assessment using a total toxic residue approach (described in the stressors of concern section of this document) , incorporating new data (described in the identification of data gaps sectio n of this document) and analytical approaches (current as of the time of the updated assessment) , label clarifications, and any additional information obtained since the previous risk assessments were conducted.

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

### 28 

### 5. Endangered Species Assessments

Consistent w ith EPA’s responsibility under the Endangered Species Act (ESA), the Agency will evaluate risks to federally listed threatened and endangered (listed) species from registered uses of pesticides in accordance with the Joint Interim Approaches developed to i mplement the recommendations of the April 2013 National Academy of Sciences (NAS) report, Assessing Risks to Endangered and Threatened Species from Pesticides

. The NAS report outlines recommendations on specific scientific and technical issues related to the development of pesticide risk assessments that EPA and the Services must conduct in connection with their obligations under the ESA and FIFRA. EPA will address concerns specific to topramezone in connection with the development of its final registration review decision for topramezone

.

In November 2013, EPA, the U.S. Fish and Wildlife Service, National Marine Fisheries (the Services), and
USDA released a white paper containing a s ummary of their joint Interim Approaches for assessing risks to listed species from pesticides. These Interim Approaches were developed jointly by the agencies in response to the NAS recommendations, and reflect a common approach to risk assessment shared by the agencies as a way of addressing scientific differences between the EPA and the Services. Details of the joint Interim Approaches are contained in the November 1, 2013 white paper

, Interim Appro aches for National

- Level Pesticide Endangered Species Act Assessments Based on the Recommendations of the National Academy of Sciences April 2013 Report.

Given that the agencies are continuing to develop and work toward implementation of the Interim Approaches to assess the potential risks of pesticides to listed species and their designated critical habitat, this ecological problem formulation supporting t he Preliminary Work Plan for topramezone does not describe the specific ESA analysis, including effects determinations for specific listed species or designated critical habitat, to be conducted during registration review. While the agencies continue to d evelop a common method for ESA analysis, the planned risk assessment for the registration review of topramezone will describe the level of ESA analysis completed for this particular registration review case. This assessment will allow EPA to focus its futu re evaluations on the types of species where the potential for effects exists, once the scientific methods being developed by the agencies have been fully vetted. Once the agencies have fully developed and implemented the scientific methods necessary to

co mplete risk assessments for listed species and their designated critical habitats, these methods will be applied to subsequent analyses of topramezone as part of completing this registration review.



### 6. Endocrine Disruptor Screening Program

Topramezone was no t included in the first group of 67 chemicals issued an order to conduct Tier 1 EDSP testing. Tier 1 screening results for List 1 chemicals are available at http://www2.epa.gov/ingredients

used

- pesticide

- products/endocrine

- disruptor

- screening

- program

- tier

- 1

- assessments

. For additional information on the EDSP, visit http://www.epa.gov/endo /

.

B. Drinking Water

Unless the residues of concern are redefine d for topramezone, a n updated drinking water assessment for registration review is not plan n ed at this time. The most recent drinking water assessment conducted for aquatic uses is expected to provide conservative EDWC s and the results are exp ected to be higher than that of any other uses current ly registered

.

### 29 

## VI. PRELIMINARY IDENTIFI CATION OF DATA GAPS

A. Environmental Fate

Table VI

. 1 identif ies environmental fate studies by MRID that offer data for each guideline requirement, as well as study classifications and whether or not further data are needed in order to support r isk

assessment.

Table VI

. 1

. Environmental Fate Data for Topramezone and Its Environmental Transformation Products

OCSPP Guideline Data Requirement Submitted
Studies (MRID) Study Classifications Are data
needed? Comments

835.2120 Hydrolysis 45902416 acceptable No

--

835.2240 Aqueous
P hotolysis 45902417 acceptable No --

835.2410 Soil
P hotolysis 45902418 acceptable No --

835.4100 Aerobic Soil
Metabolism 45902419 supplemental

No -- 45902421 supplemental

45902420 acceptable Study conducted on BAS 670H Acid (M670H05), a major metabolite of BAS 670H

835.4200 Anaerobic Soil
Metabolism No data No

--

835.4300 Aerobic Aquatic Metabolism 45902423 supplemental No Duplicate study submission

47496702

45902424 unacceptable Semi

- field study

835.4400 Anaerobic Aquatic Metabolism 45902422 supplemental

No --

48600413 supplemental All transformation products observed at concentrations greater than 10% need to be identified. In absence of additional information, these residues will be considered a toxicological concern.

835.1230
835.1240 Adsorption/ desorption and Leaching 45902425 acceptable
No --

46242703 acceptable

835.6100 Terrestrial
Field Dissipation 45902427 supplemental

No 45902426 supplemental

47498704

- This is a response to concerns related to the
TFD studies 45902426 and 45902427.

47411701

- This is a rationale document for not conducted a TFD for conifer and hardwood plantation

uses.

47496705

- This is a response to concerns related to storage stability studies for the TFD studies

. 48739401

-
45902428 unacceptable No

### 30 OCSPP Guideline Data Requirement Submitted
Studies (MRID) Study Classifications Are data
needed? Comments

Storage Stability 47498705

- This is a response to concerns related to storage stability studies for the TFD studies

.

835.6200 Aquatic Field Dissipation 48600414 s upplemental No

850.6100 Analytical
Method in
Soil 45902429 (ECM) a cceptable

Yes Data are available for to pramezone; however, the LOD/LOQ are not lower than the most sensitive terrestrial plant endpoint.

45902430 (ILV) a cceptable This ILV is for the soil method presented in
MRID 45902429.

Analytical
Method in

Water 48837001 ( ECM ) a cceptable

Yes For these submission (MRIDs 48600417, 48837001), personnel conducting the validation of the ECM were under supervision of the same study director; therefore, these submissions do not have a supporting independent laboratory validation. 48600417

( ECM ) a cceptable

45902432

(ECM) a cceptable This method is not the same as the method presented in MRIDs 48837001 and 48600417.

165

- 4
850.1730 Fish Bio

concentratio

n 45902322 u nacceptable No Additional data are not required at this time as physical

- chemistry data do not suggest topramezone will bioconcentration. Environmental Chemistry Methods (ECM) Independent Laboratory Validation (ILV)



### B. Ecological Effects

Table VI

. 2 and identify ecological effects studies for aquatic and terrestrial organisms, respectively, that provide data for each guideline requirement . These tables also identify the study classificat ions and indicate whether EFED recommends requesting additional data in order to support risk assessment and the rationale for the data request

.

Table VI

. 2 . Aquatic Ecological Effects Data for Topramezone

OCSPP Guideline Data Requirement

Test Material Submitted
Studies (MRID) Study Classifications Are data needed for
risk
assessment? Comments

850.1010 Freshwater invertebrate acute toxicity 45901820 (TEP) Acceptable No None

850.1025
850.1035 Estuarine/saltwater
invertebrate acute toxicity 48600412 (TEP) Acceptable No None

850.1075 Freshwater fish acute toxicity 45901813 (TEP) Acceptable No None

### 31 OCSPP Guideline Data Requirement

Test Material Submitted
Studies (MRID) Study Classifications Are data needed for
risk
assessment? Comments

850.1075 Saltwater fish acute toxicity 48600410 (TEP) Acceptable No None

850.1300 Freshwater invertebrate

life cycle 45902320 (TEP) Supplemental No See footnote a

.

49365103

(TGAI) Acceptable TBD None

850.1350 Estuarine/saltwater
invertebrates

life cycle 48600411 (TEP) Supplemental No None

850.1735

/ OECD

218 Benthic
invertebrates (freshwater, prolonged) 48600408 (TGAI) Supplemental ( Chironomus

riparius ) No None

850.1740 Benthic
invertebrates (marine, 10

- day) 48600407 (TGAI) Acceptable ( Leptocheirus plumulosus ) No None

850.1400 Freshwater fish early

- life stage 45902321 (TGAI) Acceptable No None

850.1400 Estuarine/saltwater
fish early

- life stage 48600404 (TGAI) Acceptable No None

850.1500 Fish life cycle (freshwater) 48600406 (TGAI) Acceptable No None

850.4400

Aquatic plant Toxicity Test Using Lemna spp. 45902329 (TGAI) Acceptable No None

46242704 (degradate : M670H05 ) Acceptable No None

45901821 (TEP) Acceptable No None

850.4500 Algal Toxicity (freshwater algae : P. subcapitata ) 45902333 (TGAI) Acceptable

Yes Guidance recommends testing on four of the most
sensitive nonvascular organisms. Three are acceptable and the fourth (MRID 45902332) on Navicula pelliculosa was deemed invalid b . Multiple incident reports have involved topramezone and plant species. Alga l Toxicity (freshwater diatom) No valid data No valid data

Algal Toxicity (marine diatom : S.

costatum ) 45902331 (TGAI) Acceptable

### 32 OCSPP Guideline Data Requirement

Test Material Submitted
Studies (MRID) Study Classifications Are data needed for
risk
assessment? Comments

850.4550 Cyanobacteria (Anabaena flos

aquae) Toxicity 45902330 (TGAI) Acceptable No

850.1740 10

- day Spiked Sediment survival of

Marine Arthropod

( Leptocheirus plumulosus ) 48600407 (TGAI) Acceptable No 

### None

850.1735

(OECD 218) Prolonged Spiked
Sediment with

( Chironomus

riparius ) 48600408 (TGAI) Supplemental No 

### None

a The aquatic invertebrate (waterflea, Daphnia magna ) life

- cycle study (MRID 45902320) did not measure the dry weight of surviving daphnids. The EFED requested that, if available, the data on dry weight be submitted in order to determine growth deficiencies of daphnids. A response was provided in MRID 47496707 to address this request. EFED agrees that, per OPPTS 850.1300 Guideline (April 1996), either total length or dry weight (or both) may suffice to meet the growth assessment requirement. Presumably, only total lengths were measured. However, they were not reported. EFED requests that, if available, the data on total lengths be submitted in order to determine growth deficiencies of daphnids. The study is still considered supplemental. The endpoint (NOAEC = 48.6 mg a.i./L) determined from this TEP

- based study has been used in past assessments. A new study (MRID 49365103) was reviewed for this problem formulation that determined greater sensitivity of the Daphnia (NOAEC = 29 mg a.i./L) to topramezone TGAI on the basis of reproduction endpoints ( i.e., the number of live neonates per surviving adult and the number of immobilized neonates of surviving adults)

.

b The aquatic plant (freshwater diatom, Navicula pelliculosa ) study (MRID 459023

- 32) is considered invalid because it was not possible to di fferentiate whether the reduction in diatom growth was due to topramezone, or from a reduction in pH. The EFED recommends a new study with N. pelliculosa. Initial pH levels at all treatment levels must be 7.5 ± 0.1 which should be maintained as closely as possible throughout the test. This information would help determine the toxicity of topramezone to freshwater diatoms. A BASF memo dated July 31, 2008 (MRID 474967

- 00) states that 'BASF is requesting a time extension for one year to complete the study.'



### Table VI

. 3 . Terrestrial Ecological Effects Data for Topramezone

OCSPP Guideline Data Requirement

Test Material Submitted Studies (MRID) Study Classifications Are data needed for risk
assessment? Comments

850.2100 Avian oral toxicity 45902309 (TGAI) Acceptable Yes Based on effects noted in the available toxicity data,

### 33 OCSPP Guideline Data Requirement

Test Material Submitted Studies (MRID) Study Classifications Are data needed for risk
assessment? Comments

48600409

(TGAI) Invalid (passerine) and the potential for passerines to be more sensitive than the species previously tested (i.e., bobwhite quail) , EFED recommends requesting a

new passerine study. See footnote a

.
850.2200 Avian dietary toxicity 45902311 (TGAI) Acceptable (mallard) No None

45902310

(TGAI) Acceptable (quail; upgraded from supplemental) No None

850.2300 Avian reproduction 45902313 (TGAI) Supplemental (mallard) No See footnote b

.

49365102

(TGAI) Supplemental (mallard) Yes See footnote c

.

45902312

(TGAI) Acceptable (quail; upgraded from supplemental) No The study endpoints are not
the most sensitive relative to the other avian reproduction studies and
have not been used in previous risk assessments.

Non

guideline Avian inhalation No data No Based on STIR analysis, risks through inhalation pathway are not expected.

81

- 1 Acute mammalian
oral LD 50 (rat) 45902118; 45902119;
45902120 Acceptable (3x) No None

83

- 4 Mammalian Reproduction (rat) 45902214 Acceptable No None

### 34 OCSPP Guideline Data Requirement

Test Material Submitted Studies (MRID) Study Classifications Are data needed for risk
assessment? Comments

850.3020 Honey bee adult

acute contact toxicity 45902325 (TGAI) Acceptable

No Tier 1 toxicity test.

45901814 (TEP) Supplemental d

850.3030 Honey bee toxicity of residues on foliage None No This study is not triggered based on the reported endpoint in the honey bee adult acute contact study.

Non

guideline
OECD TG
213 Honey bee adult acute oral toxicity

TGAI 45901814 (TEP) Supplemental d No Tier 1 toxicity test.

Non

guideline
OECD TG
237 Honey bee larvae acute oral toxicity

TGAI No data Yes Tier 1 toxicity test.

Non

guideline Honey bee larvae chronic oral toxicity

TGAI No data Yes Tier 1 toxicity test.

Non

guideline Honey bee adult chronic oral toxicity

TGAI No data Yes Tier 1 toxicity test.

Non

guideline
OECD Guidance
75 Semi

- field testing for pollinators

TEP No data Yes Tier 2 test contingent on results of tier 1 tests and screening level residues.

Non

guideline Field trial of residues in pollen
and nectar

TEP No data Yes Tier 2 test contingent on results of tier 1 tests and screening level residues.

850.3040 Field testing for pollinators

TEP No data Yes Tier 3 test contingent on results of earlier tiers of testing.

### 35 OCSPP Guideline Data Requirement

Test Material Submitted Studies (MRID) Study Classifications Are data needed for risk
assessment? Comments

850.4100 Terrestrial plant toxicity: Tier II seedling

emergence 45902327 (TEP, parent ) Acceptable No Data in this study is on the TEP with the parent compound. Data was requested for degradate in previous assessments.

49365104

(TGAI,
metabolite
BAS
M670H 05 ) Supplemental e

, for qualitative

use No Though the test was not conducted at concentrations high enough
to detect an IC 25 for either monocot or dicot, the study suggests that the tested
metabolite is not as toxic as the parent compound.

850.4150 Terrestrial plant toxicity: Tier II vegetative vigor 45902328 (TEP, parent ) Acceptable No Data in this study is on the TEP without the adjuvant and/or surfactant. In previous assessments data was requested for the parent plus adjuvant and surfactant.

49365105

(TGAI, parent
BAS 670

01H + adjuvant ) Supplemental f

, for quantitative

use No The study uses nomenclature for a metabolite (BAS 670 01H)
but chemical structure confirms the test compound was the parent.

a For the zebra finch, a fasting period prior to dosing is expected to last 2

- 3 hours. The fasting period in the study
was 20

- 22 hours. The prolonged fasting may have stressed the birds, and also led to altered metabolic processes and changes in gut motility. As a result, the prolonged fasting (20

- 22 hours) could potentially have led to fast excretion of the test compound without adequate time for absorption into the test organism (evidenced by diarrhea noted in the control and all treatment groups within the fir st hour after dosing), which might have the equivalent effect of regurgitation in the study.

b All three concentrations tested elicited adverse effects on hatchling body weight and adult female weight gain; therefore, a NOAEC could not be determined. A resp onse was provided in MRID 47496707 to address this requirement but with which EFED did not agree. Without a definitive NOAEC value, EFED cannot conclusively determine avian chronic risk. Therefore, EFED continued to recommend that a new study be performed with concentrations lower than the tested concentrations in order to establish a NOAEC. A new study (MRID 49365102) was submitted and reviewed for this problem form ulation. However, see footnote ( c )

.

c All three concentrations tested elicited adverse effect s on adult male body weight gain; therefore, a NOAEC
could not be determined.

d The acute oral component of the study is not an EPA guideline study.

e Test substance is TGAI (as opposed to TEP) topr amezone transformation product (BAS M670H 05).

f Test substance is TGAI (as opposed to TEP) topramezone mixed with an adjuvant

### 36 

## VII. REFERENCES

USEPA. 2004. Overview of the Ecological Risk Assessment Process in the Office of Pesticide Programs

. January 23, 2004. Office of Pesticide Programs. Office of Prevention, Pesticides, and Toxic Substances

. Available at : http://www.epa.gov/espp/consultation/ecorisk

- overview.pdf USEPA. 2005. Wolf, J., Termers, S., Topramezone (BAS 670H) Herbicide CAS Name, [3

- (4,5

- Dihydro

- 3

- isoxazolyl)

- 2

- methyl

- 4

- (methylsulfonyl)phenyl](5

- hydroxy

- 1

- methyl

- 1H

- pyrazol

- 4

- yl) methanone CAS Registry Number, 210631

- 68

- 8 Tier II Drinking Water Assessment March 18,
2005 (DP Barcode: 388368)

USEPA. 2005. Carey, S., Termes, S., Wolf, J. New Chemical Registration: Ecological Risk Assessment of Proposed Use on Corn (incl. grain, seed, popcorn, and sweet corn). May 12, 2005. (DP Barcode: 290065)

USEPA. 2008. Hetrick, J., Corbin, M. Topramezone (BAS 670H) Herbicide CAS Name, [3

- (4,5

- Dihydro

- 3

- isoxazolyl)

- 2

- methyl

- 4

- (methylsulfonyl)phenyl](5

- hydroxy

- 1

- methyl

- 1H

- pyrazol

- 4

- yl) methanone CAS Registry Number, 210631

- 68

- 8 Tier I and II Drinking Water Assessment September, 29, 2008 (DP Barco de: 356497)

USEPA. 2009. Crk, T., Termes, S., Hetrick. J. Ecological Risk Assessment for the Section 3 New Use Registration of Topramezone on non

- cropland areas. March 10, 2009. (DP Barcodes: 352689, 354091, 355501)

USEPA

. 2011. Hetrick, J., Spatz, D. Dr inking Water Assessment to Support Topramezone Use on Golf Courses, Sod Farms, and Residential Lawns November, 14, 2011 (DP Barcode: 388368)

USEPA. 2012. Wolf. J., Crk. T. Ecological Risk Assessment for the Section 3 New Use Registration of Topramezone on new golf courses, sod farms, and residential turfgrass uses. January 9, 2012. (DP Barcode: 397476).

USEPA. 2013. Wolf, J., Drinking Water Exposure Assessment for a Proposed Increase of the maximum use rate of Topramezone Frequency Herbicide (EPA Reg. No. 7969

- 281) for non

- cropland uses, and Proposed New Use for Direct Applications to Aquatic Environments (Oasis Aquatic Herbicide, EPA File Symbol No. 7969

- GGO) January, 29, 2013 , (DP Barcodes: 408687; 401166)

USEPA. 2013. Crk. T. Wolf. J. Ecological Risk Assessment for the Proposed New Use of Topramezone for Aquatic Vegetation Management. May 16, 2013 . (DP Barcode: 400305).

USEPA. 2014. ECOTOX User Guide: ECOTOXicology Database System . Version 4.0. Available: http:/www.epa.gov/ecotox/

US EPA. 2015. LaVerne, D., Topramezone Label Use Report Package in Support of Registration Review, January 20, 2015

### 37 

### APPENDIX A. BIBLIOGRAPHY

Table A. 1. Environmental Fate Studies Submitted for Topramezone
Guideline MRID Classification Citation

Hydrolysis
835.2010 45902416 Acceptable Venkatesh, K. (1999) Hydrolysis of BAS 670 H (Pyrazol

- 4

- (Carbon 14)) in Aqueous Media: Lab Project Number: 56797: 99/5070: C7. Unpublished study prepared by BASF Corporation. 80 p. Aqueous Photolysis
835.2240 45902417 Acceptable Guirguis, A. (2000) Water Photolysis of (Carbon 14)

- BAS 670 H: Lab Project Number: 56799: 1999/5100. Unpublished study prepared by BASF Corporation. 65 p.

Soil Photolysis
835.2410 45902418 Acceptable Singh, M. (2002) Photolysis of (Carbon 14)

- BAS 670 H on Soil: Lab Project Number: 66424: 2002/5004142. Unpublished study prepared by BASF Corporation. 115 p.

Aerobic Soil
Metabolism

835.4100 45902419 Supplemental Venkatesh, K. (2002) Aerobic Soil Metabolism of (Carbon 14)

- BAS 670 H in a US Soil: Lab Project Number: 64444: 2001/5003312. Unpublished study prepared by BASF Agro Research and Agvise Laboratories. 83 p.

45902421 Supplemental Singh, M. (2002) Aerobic Degradation of (Carbon 14)

- Phenyl))

- BAS 670 H in a US Soils: Lab Project Number: 58525: 2002/5003685. Unpublished study prepared by BASF Agro Research and Agvise Laboratories. 216 p.

45902420 Acceptable Venkatesh, K. (2002) Aerobic Soil Metabolism of (Carbon 14)

- BAS 670 H Acid in a US Soil: Lab Project Number: 66422: 2002/5003792. Unpublished study prepared by BASF Agro Research and Agvise Laboratories. 68 p.
Anaerobic Soil

Metabolism

835.4200 No Data

Aerobic Aquatic

Metabolism

835.4300 45902423 Supplemental David, M. (2002) BAS 670 H: Aerobic Aquatic Metabolism: Lab Project Number: 56940: 2002/5003947: ENV 01

- 055. Unpublished study prepared by BASF Corporation. 165 p.
47496702 Duplicate submission as 45902423

45902424 Unacceptable Fent, G. (2002) Degradation and Distribution of BAS 670 H in
a Water

- Sediment System Under Outdoor Conditions: Final Report: Lab Project Number: 2002/1007741: BAS670. Unpublished study prepared by Staatliche Lehr

- und Forchungsanstalt. 43 p.

Anaerobic

Aquatic Metabolism

834.4400 45902422 supplemental Guirguis, A. (2002) Anaerobic Aquatic Metabolism of (Carbon 14)

- BAS 670 H: Final Report: Lab Project Number: 58523: 2002/5003696. Unpublished study prepared by BASF Corporation and BASF Aktiengesellschaft. 170 p.

48600413 supplemental McGinty, K. (2012) Anaerobic Aquatic Metabolism of (Carbon 14)

- BAS 670 H. Project Number: 2011/7005338/OCR, 402577. Unpublished study prepared by BASF Corporation. 181p.

47496703 not classified Paulick, R. (2008) BASF Response to EPA Conditions of Registration for Topramezone: Anaerobic Aquatic Metabolism

- MRIDs 45902422. Project Number: 2008/7012539. Unpublished study prepared by BASF Agro Research. 11 p.

### 38 Guideline MRID Classification Citation

Terrestrial Field Dissipation
835.6100 45902426 supplemental Jackson, S.; Saha, M. (2002) 2000 Field Dissipation of BAS 670
H in Terrestrial Use Patterns: Lab Project Number: 63880: 2002/5003700: A63880. Unpublished study prepared by BASF Corporation, Ag Search Company, and Prairie Ag Research. 557 p.

45902427 supplemental Jackson, S.; Saha, M. (2002) 2000 Field Dissipation of BAS 670
H in Terrestrial Use Patterns for Canada: Lab Project Number: 59933: 2002/5003699: 2002/5003700. Unpublished study prepared by BASF Corporation and Agvise Laboratories, Inc. 184 p.

47411701 not classified Lingard, S.; Zawierucha, J.; Akers, R. (2008) Rationale for a Terrestrial (Soil) Dissipation Study in Support of Conifer and Hardwood Plantation Use with BAS 670 01 H. Project Number: 2008/7004905, RTP/NC/27709. Unpublished study prepared by BASF Agro Research. 10 p.

47496704 not classified Panek, M . (2008) BASF Response to Conditions of Registration for Topramezone: Terrestrial Field Dissipation

- MRIDs 45902426 and 45902427. Project Number: 2008/7012570. Unpublished study prepared by BASF Agro Research. 13 p.

47496705 not classified Panek, M. (20 08) BASF Response to Conditions to Registration for Topramezone: Terrestrial Field Dissipation

- Storage Stability

- MRID 45902468. Project Number: 2008/7012571. Unpublished study prepared by BASF Agro Research. 22 p.

48739401 supplemental Negley, T.; Warren, R.; Newcombe, A. (2012) Dissipation of BAS 670 H (Topramezone 2.8 SC Herbicide) in Bare Soil Plots
at Test Sites Located in North Carolina and Texas: Final Report. Project Number: 2011/7002506/OCR, 201108/08/01, 328058. Unpublished study prepared b y Arcadis and ADPEN Laboratories, Inc. 938p.

Aquatic Field

Dissipation
835.6200 48600414 supplemental Petty, D.G. 2011. Aquatic Dissipation of Topramezone in Freshwater Systems. Unpublished study performed by NDR Research, Plainfield, IN; EPL

- BAS, Niantic , IL; Agvise Laboratories Inc., Northwood, ND; Florida Pesticide Research, Oviedo, FL; and Paragon Research, Zionsville, IN; sponsored and submitted by BASF Corporation, Agricultural Products Division, Research Triangle Park, NC. Study ID No.:
NDR0901. BAS F Registration Doc. No.: 2011/7006384. Experiment initiation February 3, 2010 and completion October 25, 2011 (p. 3).

Adsorption/ Desorption Batch Equilibrium
835.1230 45902425 supplemental Zirnstein, M. (2002) Adsorption/Desorption

-- Study of BAS
670 H and M670H05 (Metabolite of BAS 670 H) on Six North American Soils: Final Report: Lab Project Number: PI020020: 2002/1008895. Unpublished study prepared by BASF Aktiengesellschaft. 73 p. {OPPTS 835.1230}

46242703 acceptable Zirnstein, M. (2003) Adsorption / Desorption

- Study of BAS 670 H Metabolite M670H10 (Reg. No. 4969168) on Six North American Soils: Final Report. Project Number: 168585, 2003/1009251. Unpublished study prepared by BASF Aktiengesellschaft and BASF Aktiengesellschaft. 79 p.

### 39 Guideline MRID Classification Citation

Method
Valid ation
850.6100 45902429 acceptable Saha, M. (2002) Validation of BASF Method No. D0103: The
Determination of Residues of BAS 670 H and Its Metabolites in Soil Using LC

- MS/MS: Lab Project Number: 64266: 2002/5002831: 64256. Unpublished study prepared by BAS F Corporation. 67 p.

45902430 acceptable Jackson, S.; Saha, M. (2002) 2000 Field Dissipation of BAS 670 H in Terrestrial Use Patterns for Canada: Lab Project Number: 59933: 2002/5003699: 2002/5003700. Unpublished study prepared by BASF Corporation and Agvise Laboratories, Inc. 184 p.

45902432 Supplemental (not an independent
validation the study director was same for
both ECM and ILV) Genari, G. (2000) Validation of Analytical Method CP 357 "Bestimmung von BAS 670 H (Reg.

- Nr. 375080) in Wasser
Mittels HPLC": Final Report: Lab Project Number: PCP05706: 2000/1013455. Unpublished study prepared by BASF Aktiengesellschaft. 14 p.

45902431 acceptable Genari, G. (2000) Determination of BAS 670 H (Reg. No. 375080) in Water by Means of HPLC: Lab Project Numbe r: 2001/1019440: 357. Unpublished study prepared by BASF Aktiengesellschaft. 20 p.

Bioconcentration
850.1730 45902322 unacceptable Nietschmann, D. (2002) Uptake, Depuration,
Bioconcentration and Metabolism of Carbon

- 14 Labeled BAS 670 H in Bluegill Sunfish (Lepomis macrochirus) Under Flow

Through Conditions: Final Report: Lab Project Number: 56754: 2002/5002984: 46811. Unpublished study prepared by BASF Corporation. 40 p. {OPPTS 850.1730}

### 40 

### APPENDIX B. AD DITIONAL ENVIRONMENTAL FATE DATA FOR TOPRAMEZONE AND ITS
TRANSFORMATION PRODUCTS

Test System K d K oc K f K foc 1/n Topramezone
Idaho Loam pH 6.7, 3.7% OC, 6.3% OM 1.81 48.34 1.40 38.3 9 0.88

South Dakota Silt Loam pH 5.9, 2.9% OC, 4.9% OM 3.73 130.93 2.59 90.8 8 0.85

Iowa Loam pH 6.8, 3.7% OC,
6.4% OM 2.59 69.72 1.9 8 53.1 2 0.86
Indiana Silt Loam pH 6.9, 0.81% OC, 1.4% OM 0 .5 6 68.61 0.4 4 53.70 0.82
Minnesota Clay Loam pH 6.1, 4.1% OC, 7.0% OM 7.47 183.61 4.86 119.41 0.86
North Carolina Sandy Loam pH 5.7, 1.2% OC, 2.1% OM 6.93 48.34 3.62 296.72 0.7 9

M670H10
Idaho Loam pH 6.7, 3.7% OC, 6.3% OM 13.80 376.9 3 10.66 291.28 0.93

South Dakota Silt Loam pH 5.9, 2.9% OC, 4.9% OM 34.73 1218.6 7 23.85 836.93 0.92
Iowa Loam pH 6.8, 3.7% OC,
6.4% OM 30.04 807.43 19.49 523.96 0.90
Indiana Silt Loam pH 6.9, 0.81% OC, 1.4% OM 6.94 856.7 5 4.35 536.85 0.86
Minnesota Clay Loam pH 6.1, 4.1% OC, 7.0% OM 81.0 4 1991.11 52.61 1292.61 0.92
North Carolina Sandy Loam pH 5.7, 1.2% OC, 2.1% OM 91.01 7459.84 69.24 5675.61 0.950

M670H05 Minnesota Clay Loam pH 6.1, 4.1% OC, 7.0% OM 0.11 2.80 0.1 2 2.60 0.90 North Carolina Sandy Loam pH 5.7, 1.2% OC, 2.1% OM 0.20 16.2 9 0.1 8 14.34 0.88

### 41 Chemical Name Chemical Structure

M670H01,
BAS 670 H cyano [3

- Cyano

- 4

- methane

- sulfonyl

- 2

- methyl

phenyl](5

- hydroxy

- 1

- methyl

- 1H

- pyrazol

4

- yl)methanone

SMILES: C1=N[N](C(=C1C(C2=CC=C(C(=C2C)C#N)[S ](=O)(=O)C)=O)O)C S O

O O N

N N OH

M670H05
BAS 670 H acid 3

- (4,5

- Dihydro

- isoxazol

- 3

- yl)

- 4

- methanesulfonyl

- 2

- methyl

- benzoic acid

SMILES: C(C1=CC=C(C(=C1C)C2=NOCC2)[S](=O)(= O)C)=O S O

O HO O

N O

M670H10 6

- [(5

- Hydroxy

- 1

- methyl

- 1H

- pyrazol

- 4

- yl)carbonyl]

- 5

- methyl

- 2,3

- dihydro

- 4H

- 1

- benzothiopyran

- 4

- one

SMILES: C1=N[N](C(=C1C(C2=CC=C3C(=C2)C(CCS3) =O)=O)O)C O

N N OH S O

M670H12 (tautomer) mw 335.0940 g/mol, C 15 H 17 N 3 O 4 S

M670H11 Topramezone structural isomer mw 363.0889 g/mol, C 16 H 17 N 3 O 5 S

### 42 

### APPENDIX C. SIP ANALYSIS RESULTS

Table C 1. SIP Inputs (using the lowest solubility value at pH 5 of 0.98 g/L)

Parameter Value Chemical name Topramezone Solubility (in water at 25 o C; mg/L) 980

Mammalian LD 50 (mg/kg

- bw) 2000 Mammalian test species laboratory rat Body weight (g) of "other" mammalian species

Mammalian NOAEL (mg/kg

- bw) 200 Mammalian test species laboratory rat Body weight (g) of "other" mammalian species

Avian LD 50 (mg/kg

- bw) 2000 Avian test species northern bobwhite quail Body weight (g) of "other" avian species Mineau scaling factor 1.15

Mallard NOAEC (mg/kg

- diet) 100 Bobwhite quail NOAEC (mg/kg

- diet) NOAEC (mg/kg

- diet) for other bird species Body weight (g) of other avian species NOAEC (mg/kg

- diet) for 2nd other bird species Body weight (g) of 2nd other avian species

Table C 2. Mammalian Results taken from SIP

Parameter Acute Chronic Upper bound exposure (mg/kg

- bw) 168.5600 168.5600 Adjusted toxicity value (mg/kg

- bw) 1538.3211 153.8321 Ratio of exposure to toxicity 0.1096 1.0957

Conclusion* Exposure through drinking water alone is a potential

concern for mammals Exposure through drinking water alone is a potential

concern for mammals

Table C 3. Avian Results taken from SIP

Parameter Acute Chronic Upper bound exposure (mg/kg

- bw) 793.8000 793.8000 Adjusted toxicity value (mg/kg

- bw) 1440.8590 4.9613 Ratio of exposure to acute toxicity 0.5509 159.9998

Conclusion* Exposure through drinking water alone is a

potential concern for birds Exposure through drinking water alone is a

potential concern for birds

*Conclusion is for drinking water exposure alone. This does not combine all routes of exposure. Therefore, when aggregated with other routes ( i.e ., diet, inhalation, dermal), pesticide exposure through drinking water may contribute to a total exposure that has potential for effects to non

- target animals.

### 43 

### APPENDIX D. STIR ANALYSIS RESULTS

The S creening T ool for I nhalation R isk (STIR v.1.0, November 19, 2010) was used to calculate an upper bound estimate of exposure using topramezone’s vapor pressure and molecular weight for vapor phase exposure as well as the maximum application rate and method of application for spray drift. STIR incorporates results from several toxicity studies including acute oral and inhalation rat toxicity endpoints obtained fr om the “six

- pack” of core studies, which are a series of six guideline studies that are submitted to the Registration Division of the Office of Pesticide Programs for technical and formulated products of a pesticide [acute oral LD 50 

### >2,000 mg a.i./kg

- bw, r at (MRID 45902118); acute
inhalation LC 50 

### > 5.05 mg/L, rat (MRID 45902124)] as well as the most sensitive acute oral avian toxicity endpoint [LD 50 

### > 2,000 mg a.i./kg

- bw, bobwhite quail (MRID 45902309)]. Based on the results of the STIR model, inhalation exposure alone was not determined to be a potential pathway of concern for avian or mammalian species on an acute basis for either ground or aerial spray types. Detailed information about STIR v.1.0, as well as the tool, can be found on the EPA’s website at: http://www.epa.gov/pesticides/science/models_pg.htm#terrestrial

.

### 44 

# Input

Application and Chemical Information

Enter Chemical Name Topramezone Enter Chemical Use Aquatic Is the Application a Spray? (enter y or n) y If Spray What Type (enter ground or air) ground Enter Chemical Molecular Weight (g/mole) 363.39 Enter Chemical Vapor Pressure (mmHg) 7.30E

- 13 Enter Application Rate (lb a.i./acre) 0.35

Toxicity Properties

**Bird**
Enter Lowest Bird Oral LD 50 (mg/kg bw) 2000 Enter Mineau Scaling Factor 1.15 Enter Tested Bird Weight (kg) 0.178
**Mammal**
Enter Lowest Rat Oral LD 50 (mg/kg bw) 2000
Enter Lowest Rat Inhalation LC 50 (mg/L) 5.05
Duration of Rat Inhalation Study (hrs) 4 Enter Rat Weight (kg) 0.35



# Output Results Avian (0.020 kg ) Maximum Vapor Concentration in Air at Saturation (mg/m 3 ) 1.43E

- 08
Maximum 1

- hour Vapor Inhalation Dose (mg/kg) 1.79E

- 09 Adjusted Inhalation LD 50 2.82E+01 Ratio of Vapor Dose to Adjusted Inhalation LD 50 6.37E

- 11
Maximum Post

- treatment Spray Inhalation Dose (mg/kg) 3.70E

- 02 Ratio of Droplet Inhalation Dose to Adjusted Inhalation LD 50 1.31E

- 03



### Results Mammalian (0.015 kg ) Maximum Vapor Concentration in Air at Saturation (mg/m 3 ) 1.43E

- 08
Maximum 1

- hour Vapor Inhalation Dose (mg/kg) 2.26E

- 09 Adjusted Inhalation LD 50 3.01E+02 Ratio of Vapor Dose to Adjusted Inhalation LD 50 7.50E

- 12
Maximum Post

- treatment Spray Inhalation Dose (mg/kg) 4.65E

- 02 Ratio of Droplet Inhalation Dose to Adjusted Inhalation LD 50 1.55E

- 04