### Page 3 of 66



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

Mesotrione

2

- [4

- methylsulfonyl

- 2

- nitrobenzoyl]

- l,3

- cyclohexanedio 

## CAS Registry Number: 104206

- 82

- 8

PC Code: 122990

Prepared by:

Michael J. Wagman , Biologist Iwona L. Maher, Chemist U. S. Environmental Protection Agency Office of Pesticide Programs Environmental Fate and Effects Division

Environmental Risk Branch VI 1200 Pennsylvania Ave., NW

Mail Code 7507P Washington, DC 20460 Reviewed by: William P. Eckel, Senior Science Advisor Amy Blankinship, Senior Scientist Mark Corbin, ERB 6 Branch Chief



### J une 3 , 2014 

## Office of Chemical Safety

and Pollution Prevention

### Page 4 of 66



## Table of Contents

1. Executive summary

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

2. Introduction

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

3. Use Characterization

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

4. Conclusions from Previous Risk Assessments

................................ .......................... 10

4.1. Ec ological Risk Assessment

................................ ................................ ...................... 10

4.2. Drinking Water Exposure Assessments

................................ ............................. 11

4.3. Clean Water Act Programs

................................ ................................ ................. 11

5. Environmental Fate and Transport

................................ ................................ ............. 12

6. Receptors

................................ ................................ ................................ .................... 15

6.1. Effects to Aquatic Organisms

................................ ................................ ............ 16

6.2. Effects to Terrestrial Organisms

................................ ................................ ........ 20

6.3. Ecological Incidents

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

7. Exposure Pathways of Concern

................................ ................................ ................. 25

8. Analysis Plan

................................ ................................ ................................ ............. 26

8.1. Stressors of Con cern

................................ ................................ ........................... 26

8.2. Measures of Exposure

................................ ................................ ........................ 26

8.3. Measures of Effect

................................ ................................ ............................. 28

9. Endangered Specie s Assessments

................................ ................................ .......... 28

10. Endocrine Disruptor Screening Program

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

11. Preliminary Identification of Data Gaps

................................ ............................ 30

11.1. Environmental Fate

................................ ................................ ......................... 30

11.2. Effects

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

12. References

................................ ................................ ................................ .................. 39 Appendix A: Label Use Information for Mesotrione (PC Code 122990) by Use Site 41 Appendix B: Summary Data for Mesotrione Related Incidents

................................ ... 44 Appendix C: SIP Inputs and Outputs

................................ ................................ ................. 6 5

### Page 5 of 66



# 1. Executive summary

The Environmental Fate and Effects Division (EFED) has completed the preliminary problem formulation for the ecological risk, environmental fate, endangered species, and drinking water assessments to be conducted as part of the registration review of

mesotrione . The problem formulation de scribes the methods planned to be used during the completion of drinking water and ecological risk assessments in support of registration review and provides an ove rview of the environmental fate, ecological

effects , and potential risks associated with the use of mesotrione as well as uncertainties unique to the risk assessment of mesotrione . This document also identifies additional studies that would be beneficial to the conduct of an ecological risk assessment. Major findings include:

The following env ironmental fate data gaps exist for mesotrione :

 Environmental Chemistry Methods and Independent Laboratory Validation on Soil, Water, and Sediment (OCSPP Guideline 8 50.6 100): The environmental chemistry method for mesotrione residues of concern (parent plus major degradates) in soil, water, and sediment as well as independent laboratory validation of the methods are required to support monitoring for mesotrione residues and current and newly submitted environmental fate and ecological

effects data. This is considered a major data gap.

 Anaerobic soil metabolism for Mesotrione ( Guideline 835.42 00 ): No data are available for anaerobic soil metabolism. It is expected that mesotrione anaerobic soil metabolism is pH dependent hence data for soils with ty pical pH for

mesotrione use areas are recommended.

 Aerobic Aquatic Metabolism for Mesotrione ( Guideline 835.43 00 ) : This data for mesotrione are limited to two British natural water

- sediment systems with experimental pH 7.9 and 6.9. T hese experimental pHs are higher than those of most of the many soils used in the aerobic soil metabolism studies, and we might expect longer half

- lives at lower aquatic system pHs. In addition, it is not certain that the microbial makeup of the British water

- sediment systems is similar to the one in the US. Therefore, a new study conducted on a US natural

- water sediment sys tem at a variety of pHs typical for me sotrione use area s is needed

. Study should be conducted until patterns of decline of parent and patterns of formation and decline of transformation products are established. For the purpose of modeling a very conservative approach will be taken in selecting the input parameters if the data are not available

.

 Anaerobic aquatic metabolism for Mesotr ione (Guideline 835.4400): Currently the data for mesotrione are limited to one flooded Radford U.S. soil system with purified water (two radiolabels and pH 6.9 to 7) and the obtained

half

- life is comparable to the aerobic soil metabolism rate, and essent ially the same as those from the two different aerobic aquatic systems. These results

### Page 6 of 66 

### indicate that metabolism progresses under suboxic conditions, and may be more influenced by pH than lower oxygen content. A n additional anaerobic aquatic

metabolism study is requested to facilitate our understand ing of mesotrione metabolism under anaerobic aquatic conditions in natural systems in variety of pH s

. Study should be conducted until patterns of decline of parent and patterns of

formation and decline of transform ation products are established. For the purpose of modeling a very conservative approach will be taken in selecting the input parameters if the data are not available.

 Ae robic Soil Metabolism for MNBA ( OCSPP Guideline 835.4100 ): N o aerobic soil metabolism data are available for MNBA alone and therefore it is

un certain if there is concern for exposure from MNBA from mesotrione use. Fate data indicate that MNBA would be a major product in many soils in which corn and other major use sites are grown

. The data are needed to alleviate the uncertainty associated with the chemical behavior in soil and availability for potential transport to surface water and availability for exposure

. The aerobic soil metabolism study should be conducted at a variety of pHs.

 Aerobic Aquatic Metabolism for MNBA (OCSPP Guideline 835.4300): The Agency has no data on the fate of MBNA under aerobic aquatic conditions. The longer MBNA persists in the soil, the greater the opportunity for it to move into surface water, where its fate is unknown and where it potentially could impact aquatic species. Data from th is study would address the uncertainty in regards to MNBA behavior in the aquatic environment under aerobic conditions. The study should be conducted at a variety of p Hs.

 Analytical Methods ( OCSPP Guideline 835

. 6100 ) with the St orage Stability

Characteristics for Surface Water Monitoring (MRID 47244503): It is requested for the purpose of upgrading an unacceptable Surface Water Monitoring study to supplemental because surface water samples were stored for up to 18 months before analysis. If upgraded, the available surface water data could be used for qualitative characterization or even used more quanti tatively (chronic exposure results) in the risk assessment.

 Drinking Water Treatment Method for MRID 47578301 ( OCSPP Guideline

not Available ) : Information on the types of treatment that were used in surface water samples from the monitoring study ( MRID 47 244503 ) to obtain drinking

w ater are requested

.

Data are requested for t he following mesotrione ecolo gical data gaps:

Estuarine/ M arine Invertebrate Acute Toxicity Study using MNBA (OCSPP Guideline 850.1035) : Mesotrione is significantly more toxic on an acute basis to estuarine/marine invertebrates compared to freshwater invertebrates. D ata for the degradates indicate that they are substantially ( ~5.3

— 6.3x ) more toxic than parent

mesotrione to daphnids

. If t he degradate MNBA is also similarly more toxic to

### Page 7 of 66 

### mysids than parent mesotrione , our calculations suggest that adverse acute effects

for estuarine/marine invertebrates could occur at surface water concentrations

near 1/20 th 

### the peak mesotrione EECs calculated in past assessments (USEPA, 2013; D408583). A preliminary I ndividual E ffect C hance (IEC) analysis

conducted for this problem formulation indicates that the chance of an adverse effect to an individual organism is 0.2% for exposure to paren t and may be up to

4.3% for the metabolites. The se calculations suggest a potential for risk to listed species of saltwater invertebrates

. S ince AMBA is usually produced under anaerobic conditions, it is not expected that there would be a likely exposure pathway for saltwater inv ertebrates in the water column and therefore, an acute mysid toxicity test with this degradate is not requested at this time. However, the lack of an acute mysid toxicity study with the degradate MNBA remains a major data gap , and this study is requested

. In the absence of this information, EPA may rely on the differential in the acute daphnid toxicity studies between parent mesotrione and the MNBA degradate to calculate an acute mysid endpoint

for MNBA’s effects to saltwater inve rtebrates and compare that to expected

MNBA EECs in the risk assessment. However, it is unc ertain whether this approach would underestimate or overestimate risk to saltwater invertebrates.

 Estuarine/Marine Invertebrate Chronic Toxicity Study (OCSPP Guid eline 850.1350): Mesotrione has outdoor uses that may result in exposure to

estuarine/marine invertebrates. Mysids are the most sensitive aquatic animal on an acute basis and are significantly (~2 orders of magnitude) more sensitive than daphnids. No acce ptable chronic data are available for either freshwater or saltwater invertebrates, therefore an acute to chronic ratio (ACR) approach cannot currently be used. Since the mysid is significantly more acutely sensitive than the daphnid, the lack of a chronic saltwater invertebrate study is a major data gap.

EPA may use acute and chronic estuarine/marine invertebrate data in an ACR approach to estimate a chronic freshwater invertebrate endpoint. In the absence

of these data, ris k cannot be precluded f or aquatic invertebrates.

 Terrestrial Plant Seedling Emergence Tier II Study (OCSPP Guidelines

8 50.4100 ) with the degradate MNBA on onion, lettuce and cabbage : No data

are available for the toxicity of the metabolite MNBA to terrestrial plants. Since MNBA is a major degradate that forms at a rate up to 60% of parent in aerobic

soil metabolism studies to which non

- target plants may be exposed via runoff,

these data are needed to evaluate the risk posed to terrestrial plants from runoff containing the degradate. Testing should be conducted using the most sensitive monocot (onion) and dicot (lettuce and cabbage) species as determined from the parent mesotrione seedling emergence data.

The following ecological data gaps for mesotrione are also noted, but as new data would likely not change the risk assessment, the data are not needed at this time:

### Page 8 of 66



###  Freshwater Invertebrate Life Cycle (OCSPP Guideline 850.1300) : A

submitted chronic daphnid study was previously deemed Acceptable. However, this study (MRID 44505010 ) had several issues confounding its results (including precipitates and extremely acidic conditions in high concentrations and inconsistent effects at lower concentrations) which has resulted in its downgrade to Supplemental

— Qualitative. The lack of an acceptable chronic freshwater invertebrate study is a data gap. However, on an acute basis the estuarine/marine invertebrate (mysid) was much more sensitive (2

- 3 orders of ma gnitude) to mesotrione than the freshwater invertebrate (daphnid). Previous assessments indicate that maximum expected environmental concentrations are substantially lower than acute freshwater invertebrate endpoints and levels of concern were not

exceeded . Therefore, if a chronic mysid study is available at the time of the risk assessment, an acute to chronic ratio (ACR) can be generated from the acute and chronic mysid data and applied to the acute daphnid data to estimate a chronic daphnid endpoint.

 Estuarine/Marine Fish Early

- Life Stage Toxicity Study (OCSPP Guideline 850.1400): An estuarine/marine fish early life

- stage test using the TGAI has not been submitted, since it was not considered to be necessary based on previous risk

assessments for mesot rione. An ACR approach cannot be used because the endpoints in the acute data are nondefinitive. In the absence of these data EPA will use the rainbow trout early life stage data as a surrogate for the chronic

saltwater fish. T he utility of a n estuarine /marine fish ELS study for the risk assessment is considered low at this time, given the predicted difference between the exposure estimates from previous assessments and the toxicity estimate derived using the freshwater fish ELS study. Therefore, a n estu arine/marine fish early life stage toxicity test is not requested at this time

.

 Acute Avian Oral Toxicity Study

— Passerine species (OCSPP Guideline 850.2100): No data are available for passerine species, which may be more

sensitive than the tested bobwhit e species. However, the LD 50 

### and LC 50 

### data for the mallard and bobwhite were all nondefinitive (“greater than”) values, and there were no sublethal effects in any acute or subacute avian study . Maximum use rates for currently registered uses of mesotrione are expected to result in residues in dietary items that are below any levels of concern for birds using the

nondefinitive acute endpoints. Therefore , a passerine study is not need ed at this

time. However, if there is an expansion of the Experimental Use Permit ( EUP ) on soybeans (which has a maximum annual application rate that is three times other currently registered uses) to a broader use pattern or if other new registrations with higher application rates are proposed , the lack of passerine data would be considered a major data gap.

Major uncertainties:

### Page 9 of 66



### Major uncertainties are raised by the lack of chronic aquatic invertebrate data for parent mesotrione and both terrestrial plant and acute estuarine/marine invertebrate data for mesotrione’s major deg radate MNBA

. Lack of fate data for both parent mesotrione and MNBA is also a major uncertainty. Given the large number of reported terrestrial plant incidents for this chemical, damage to non

- target plants from spray drift from mesotrione

formul ations is of particular concern

.



# 2. Introduction

Mesotrione is a tri

- ketone compound used as a systemic p re

- emergence and post

emergence herbicide for "the selective contact and residual control of broadleaf weeds." (Callisto label, EPA Reg. No. 100

- 1131). It is absorbed from the soil by emerging weeds and through the foliage of emerged weeds. According to the registrant, it acts by inhibiting the enzyme p

- hydroxyphenylpyruvate dioxygenase (HPPD) , which is necessary for carotenoid biosynthesis resulting in photodegradation of the affected plant’s chlorophyll by sunlight. Mesotrione is a synthetic analog of leptospermone developed to mimic the effects of that natural herbicide produced in some members of the myrtle (Myrtaceae) family (Cornes, 2005).

There a re currently 27 Section 3 regis tered products

, 14 Section 24c (Special Local

Need

— SLN) registered pr oducts and 1 section 5 EUP s for mesotrione.

EFED evaluated the most recent ecological risk assessments for mesotrione in association with the update d tox icity, exposure, and usage information to determine if sufficient data are available and if further updates are needed to support registration review. Recent risk

assessments include a 2013 assessment modifying the uses on corn, sugarcane, grass seed, cra nberry and grain sorghum ( USEPA, 2013 a ; D408583 ) and a 2008 Experimenta l

Use Permit and New Use assessment on HPPD

- tolerant soybeans (USEPA, 2008 b ; D357888)

. In addition, EFED considered the latest Agency science policies and risk assessment methodologies

.



# 3. Use Characterization

Currently registered uses include asparagus, corn (field corn, field corn for silage, yel low popcorn, and sweet corn), bush and cane berries (blueberries, lingonberries, black an d red raspberries, and blackberries), cranberries, flax, sod farms, grass for s eed, millet (pearl and proso)

, oats, okra, rhubarb, sorghum (sweet and grain), s ugarcane, and soybean. Registered non

- agricultural use sites include: golf courses, lawns, ornamental t urf, ornamental flowering plants , buildings and recreational areas. For currently register ed

uses, the maximum single application rates range from 0.168 lb a.i ./ A to 0.2 5 lb a.i./A and seasonal application rates rang e from 0.188 to 0.5 lb a.i./A. Appendi x A provides additional label use information for mesotrione, organized by use site. T he EUP on soybeans has an annual ap p lication rate three times higher than any registered application

rate. The annual EUP rate is 1.5 lbs ai/A and allows for three applic ations made in 14

- d

### Page 10 of 66



### interval; i.e. 0.75 lb a.i/A, 0.375 a.i/A, and 0.375 a.i/A, resp ectively

. The highest usage, in terms of total pounds applied and total acres treated with mesotrione is on corn with approximately 98% of total usage (most usage on field corn, but also substantial usage on

sweet corn, BEAD Chemical Profile, USEPA 2014)

. Other use sites with substantial usage (average >5% of crop) of mesotrione include blueberries and sorghum (BEAD Screening Level Usage Analysis , USEP A, 2013 b )

.

Mesotrione is applied both pre

- and post

- emergence and is registered for both ground and aerial applications.



# 4. Conclusions from Previous Risk Assessments

4.1. Ecological Risk Assessment

The last ecological risk assessment conducted on mesotrio ne was the 2013 n ew u se assessment adding aerial application for corn and sugarcane, increasing the number of applications and application rate for grasses grown for seed, adding chemigation for cranberry and modifying application timing for use on grain s orghum ( USEPA, 2013 a )

. This assessment did not include a new assessment for terrestrial animals since the label changes did not impact the overall risk conclusions compared to previous assessments as the proposed maximum application rates were lower than already assessed rates on

different use sites . The assessment did evaluate risk to plants and included a spray drift analysis to characterize the extent of risk to off

- field terrestrial plants fro m spray drift for ground compared with aerial applications. The aquatic assessment was refined using Tier

II models. Risk s of concern were identified for listed and non

- listed vascular aquatic plants from the sugarcane and cranberry use patterns

, for lis ted vascular aquatic plants

from the corn use , and for listed and non

- listed monocots and dicots from all proposed

uses. No other taxa were concluded to be at risk. No data gaps were noted in this risk

assessment.

In 2008 EFED conducted a combined Section 3 New Use Assessment on Soybeans and a Section 5 Experimental Use Permit (USEPA, 2008b) which included an annual application rate of 1.5 lbs a.i./A (three times the highest previously registered rate for any

use si te ) on soybeans . For the proposed Section 3 use (applied at 0.188 lbs ai/A) , the proposed application rate was equal to the lowest previously registered rate

, and risks of

concern were identified for all categories of terrestrial plants except for non

- lis ted monocots in adjacent dry upland areas exposed to mesotrione in runoff. However, for the

EUP rate, levels of concern were exceeded for all categories of terrestrial and aquatic plants except for non

- vascular aquatic plants. Additionally, the Section 5 assessment indicated acute risk to listed species of birds (small birds feeding on short grass only) and chronic risk (all size classes of birds feeding on short grass or tall grass).

### Page 11 of 66



## 4.2. Drinking Water Exposure Assessments

The latest surface water expos ure modeling for the drinking water exposure assessment

for the EUP in 2008 was based on the Mississippi Soybean scenario. Since then

, Estimated Drinking Water Concentrations ( EDWCs ) for ground water have been simulated using the newly available PRZM

- GW model (US EPA, 2014; D 415369 )

. The total annual rate modeled was 1.5 lbs ai/A/yr (3 apps, 14

- d interval, 0.75 lb a.i/A, 0.375 a.i/A, 0.375 a.i/A, resp ectively) (USEPA, 2008

, D35451 0) . Modeling results are presented in Table 1 below

.

Table 1. Estimated D rinking Water Concentrations (EDWCs) for Mesotrione

Drinking water source (model) Use

(modeled rate) 1

- in

- 10 year

acute (μg/L) 1

- in

- 10 year

chronic (μg/L) 30

- year average

(μg/L)

Surface water A
(PRZM/EXAMS) Soybean

- EUP

(1.5 lb a i /A) ground 38.1 5.1 2.2

Ground water B
(PRZM

- GW ) Soybean

- EUP/WI corn

(1.5 lb a i /A) ground 26.2 1 8.4 ≤18.4

Ground water A
(SCI

- GROW) Soybean

- EUP

(1.5 lb a i /A) ground 0.54 ≤ 0.54 ≤ 0.54

A S ource : US EPA, 2008 ; D 354510

. B Source: US EPA, 2014, D 415369



### In addition , the registrant submitted a community water system (CWS) surface water monitoring study for mesotrione (MRID 47244503) , conducted in the Midwest, primarily in Illinois, Indiana, and Ohio

. Th is study indicate s that 18% of raw surface water samples had detections of mesotrione. The annual average raw water concentration of mesotrione was 0.22 pg/L in 2005 and 0.32 pg/L in 2006. The maximum mesotrione concentration was 2.4 pg/L in untreated water with detectable residu es lasting for at least several weeks. This study was deemed unacceptable ( upgradable to supplemental upon submittal of information on the analytical methods and storage stability characteristics since s amples were stored up to 18 mon ths before analysis )

. If upgraded, the results of the study can be incorporated into mesotrione drinking water assessments for qualitative characterization

or potentially be used more quantitatively ( chronic exposure results )

.

The same monitoring study ha d no detections of mes otrio ne in finished water. The sampling was conducted at the same time and in the same locations as that for untreated water, but there is no information as to the types of treatment that were used in sampled systems. Preliminary review of a submitted chlo rination study (MRID 47578301)

indicates that upon addition of chlorine mesotrione is rapidly transformed to the degradate MNBA.



## 4.3. Clean Water Act Programs

Mesotrione is not identified as a cause of impairment for any water bodies listed as impaired under section 303(d) of the Clean Water Act. No Total Maximum Daily Load

### Page 12 of 66



### (TMDL) criteria have been developed for mesotrione

. Aquatic benchmarks have been

established for m esotrione and are available at http://www.epa.gov/oppefed1/ecorisk_ders/aquatic_life_benchmark.htm . Any data submitted or otherwise located as part of the registration rev iew process may be used to update aquatic life benchmarks if applicable.



# 5. Environmental Fate and Transport

This chemical has acidic ionic property (pKa of 3.12; is 40 times more acidic than acetic acid) that has a major influence on the behavior of me sotrione in environmental media at different pHs. Mesotrione appears to be mobile based on K oc 

### of 16.5 to 390 L/kg

, and presents limited persistence in soil and aquatic environments. The lower the pH, the higher the sorption to soil organic matter. In soil , mesotrione dissipates throu gh aerobic

metabolism with half

- lives ranging from 5.5 days to 32 days that are increasingly rapid in

acidic environments. T he lower the pH, the higher the sorption to soil organic matter and the longer the corresponding aerobi c soil half

- life. Mesotrione major routes of dissipation include leaching into the soil profile, runoff into surface water, microbial

- mediated degradation in soil and water and photodegradation on soil

.

In the terrestrial field studies in IL, MS, and NC (MRID 44505205, 44505206, and 44505207), mesotrione dissipated rather rapidly with half

- lives ranging from 2 to14 days and did not find any residues below 6 inches. In NC small

- scale prospective groundwater study, mesotrione and its degradates were detecte d above the limit of quantitation only in

soil

- pore water at the 3 foot depth. Throughout the 38 months of the study duration, no detections of parent or degradates were made at any deeper lysimeters or in ground water. These findings are indicative that the parent is not very likely to leach into ground water in soil of a moderate to low permeability (MRID 47418901). Because m e sotrione has properties and characteristics associated with chemicals detected in ground water, this study result does not preclud e the fact that mesotrione use may result in groundwater contamination in areas where soils are very permeable, and the water table is shallow. Mesotrione may reach surface water through spray drift during its application and runof f

.

In aquatic environme nts, mesotrione is stable to hydrolysis and has limited photolysis but degrades rapidly through aerobic (half

- lives (t 1/2 

### ) = 3 to 6 days) and anaerobic

metabolism ( t 1/2 

### = 4 days). Based on physicochemical properties, mesotrione is not expected to bioconcen trate. Likewise, it is not expected to volatilize from soil. A selection of mesotrione environmental fate and transport properties is summarized in

Table 2 below.

Table 2. Physical Chemical and Environmental Fate Properties of Mesotrione.

Parameter Value Source

Selected Physical/Chemical Parameters

Chemical Structure MRID 44505131

### Page 13 of 66



### Table 2. Physical Chemical and Environmental Fate Properties of Mesotrione.

Parameter Value Source

Empirical Formula C 14 H 13 O 7 NS D253844

IUAPC Name 2

- [4

- methylsulfonyl

- 2

- nitrobenzoyl]

- l,3

- cyclohexanedio D253844

CAS Name

CAS No. 104206

- 82

- 8 D253844 Molecular Weight 3 39 g/mole Product Chemistry Physical state opaque solid DP Barcode D253844 Vapor pressure 4.30 x 10

- 8 torr DP Barcode D263245
Aqueous solubility (25  C) 1,600 mg/L DP Barcode D263245
Dissociation constants (pKa ) pKa = 3.12 at 20" C DP Barcode D253844 pH at 25 o C 3.4 (for a 1% by wt. dispersion in water) DP Barcode D253844 Henry’s Law Constant 5.1 x 10

- 7 Pa

- m 3 /mol DP Barcode: D263245 Log octanol

- to

- water partition coefficient(log P OW ) at 20" C log Pow = 0.1 1 in unbuffered water log Pow = 0.90 in pH 5 buffer log Pow <

- 1 at pH 7 and 9 buffered water DP Barcode D253844



### Persistence
Hydrolysis half

- life (pH 5, 7, 9) Stable MRID: 44373529 Aqueous photolysis half

- life 84 days (d ark corrected; 12 hr light/12 h r dark cycle ) MRID: 44537108

Soil photolysis half

- life 29 days MRIDs: 44505128 and

45196005

Aerobic soil metabolism half

life ( range in days) 5 to 32 days (mean 28.9 days)

M easured in 17 soils and found to be strongly pH correlated MRID: 44505129

DP Barcode D253844

Anaerobic aquatic metabolism

half

- life (avg. of two

radiolabels in total system) 4 days A MRID s: 44505131 and

44505132

Aerobic aquatic metabolism

half

- life (total system) 3 days (pH=7.9) and 6 days (pH=6.9) in

British natural water

- sediment systems MRID: 45196011



### Mobility
Adsorption/desorption ( K f

- oc range) 16.5 to 390 mL/g

S oil mobility was measured in 17 soils and found to be strongly pH correlated. MRID s : 44505204

Field Dissipation Terrestrial Field Dissipation 2 to 14 days (did not find any residues below 6 inches soil depth) MRIDs: 44505207 &

44505 125

, 44505206,

44505205 & 44505126

A

- The system was a flooded Radford series silt loam soil under moderately oxidizing to moderately reducing (suboxic) conditions

.



### Mesotrione appears to metabolize to two major degradates MNBA (2

- nitro

- 4

- methylsulfonylbenzoic acid) and AMBA (2

- amino

- 4

- methylsulfonylbenzoic acid), in

addition to C0 2 

### . MNBA was detected in the aerobic soil metabolis m study at up to 60%,

and AMBA in the a naerobic aquatic metabolism study at up to 60%. MNBA is formed by

### Page 14 of 66



### an oxidative process when the cyclohexane ring portion of the mesotrione molecule splits

away

. AMBA is the amine product formed by reduction of the MNBA nitro group.

AMBA aerobic soil meta bolism half

- life ranged from 16 to 27 days (MRID 44901714) and its only identified metabolite was carbon dioxide. Data were insufficient to determine the range of variation of half

- life with pH. Under suboxic conditions, half

- lives

for AMBA could not be r eliably established from formation and decline curve because of study deficiencies ( D253844 ) ; a crude estimation half

- life for AMBA under the existing study conditions is 110 days, but may be longer with greater restriction of oxygen.

Because of the acidic nature of MNBA, its sorption is likely to be affected by pH. The

aerobic soil metabolism half

- life of MNBA can only be crudely estimated from the available data and are highly uncertain. In at least two aerobic soils, MNBA half

- lives appeared to be measur ed in one to several months, but seemed to be much shorter in

others (D253844). Neither of the degradates were detected at any sampling interval of three terrestrial field dissipation studies conducted prior 1997

. MNBA was not detected in any soil samples in an NC P rospective Ground Water (P GW ) study . In the same study, AMBA was detected in soil on days 3 through 28, at concentrations 2 .4 to 6.4 ppb , with a peak at 14 days and return to the LOQ level of 2.0 ppb by 64 days. M esotrione and both degradates wer e detected in soil

- pore water at the 3 foot depth (MRID 47418901 )

. These degradates were not included in the previous risk assessments. Their physicochemical properties and available environmental fate properties ar e summaries in Table 3 below.

The ir m aximum percent formation are presented in Table 4.

Table 3. Selected Physicochemical Properties of MNBA and AMBA

Chemical Name MNBA : 4

- (methylsulfony1)

- 2

- nitrobenzoic acid

AMBA: 2

- amino

- 4

- (methylsulfonyl)benzoic acid

CAS No. MNBA : 1 10964

- 79

- 9

AMBA: Not Available Molecular Mass (g / mol) MNBA : 245.21

AMBA: 215.22

Acid Ionization Constant in Water (Ka) and pKa MNBA: 1.6 x (pKa= 1.8)

AMBA: 9.3 x (pKa = 4.0) Approximate values calculated from solubility and pH in unbuffered water given in next row below: Solubility in water MNBA: 4.0 mg/mL in unbuffered water (final pH 2.0) 14.2 mg/mL at pH 2.6 32.4 mg/mL at pH 2.9 Note:

exceeds buffer capacities at higher pH

AMBA: 0.3 mg/mL in unbuffered water (final pH 3.5) 1.8 mg/mL at pH 4.7 23 mg/mL at pH 6.1

Octanol/Water Partition Coefficient (Pow) MNBA: log Pow =

- 1.3 in unbuffered water log Pow =

- 2.6 in pH 5 buffer

AMBA: log Pow = 0.32 in unbuffered water

log Pow =

- 0.30 in pH 5 buffer Vapor Pressure MNBA: 6.4 x l0

- 7 Pa (4.8 x 10

- 9 Torr)

AMBA: 4.7 x 10

- 7 Pa (3 .5 x 10

- 9 Torr) Henry's Law Constant (Calculated from

vapor pressure and solubility above ) i n

un buffered water: MNBA: 3.9 x 10

- 8 Pa

- m 3 /mol ( 3 .9 x 10

- 13 atm

m 3 /mol)

AMBA: 3.4 x 10

- 7 Pa

- m 3 /mol (3.4 x 1 0

- l2 atm

- m 3 /mol)

### Page 15 of 66



### Table 3. Selected Physicochemical Properties of MNBA and AMBA
Adsorption/desorption ( K f

- oc ) MNBA : 3 and 6 mL/g (US soils),

less than 20, 6, and 10 mL/g (European soils)

AMBA: 45, 23, 122, 5 1, and 18 mL/g

Aerobic soil metabolism half

- life AMBA: 16, 27, and 20 days (effect of pH could not be determined)



### Table 4

. Environmental Degradates of Mesotrione

. Degradate/

Molecular formula Chemical

Structure Max Percent Formation in

%AR (Study) Source/Study MRID

MNBA

4

- (methylsulfony1)

- 2

- nitrobenzoic acid 7.9% (6 d)

6

- 8%

57.2 % (28 d) 27.9% ( 7 d) US sandy loam 46.8% ( 7 d) French l oam soil Aerobic Soil Metabol i s m ./44373531

Aerobic Soil Metabolism ./ 45 19600 6

Aerobic Soil Metabolism /44505129

Aerobic Soil Metabolism / 44505208

Aerobic Soil Metabolism / 44505208

AMBA

2

- amino

- 4

- (methylsulfonyl)benzoic

acid 9.7% (23 d)

6

- 8%

ca. 6 0 % (14 d) 4.2% (7 d) Aerobic Soil Metabolism ./ 44373531

Aerobic Soil Metabolism ./ 45 19600 6 Anaerobic Aquatic Metab olism / 44505 13 1

Aerobic Soil Metabolism / 44505208



### It is important to note that because of specific study shortcomings, their partial nature, the existence of several closely related series of studies, and the pH dependence of mesotrione and degradates, individual DERs cannot be used in isolation, but must b e taken in the context of all submitted data (US EPA, 2001 ; D253844 ).



# 6. Receptors

Tables 5 through 10 provide a summary of the aquatic and terrestrial taxonomic groups,

and the most sensitive surrogate species tested to characterize the potential acute and chronic ecological effects of mesotrione and its degradates, AMBA and MNBA

. In addition, the tables provide a preliminary overview of the potential acute toxicity of

mesotrione by providing the acute toxicity classifications.

Much of the aquatic data had issues with precipitates and highly acidic conditions , most pronounced in the highest treatments. Based on the available ecotoxicity information, mesotrione is practically non

- toxic to a ll freshwater animals and estuarine/marine fish

and slightly to moderately toxic to estuarine/marine invertebrates. The chronic freshwater

invert ebrate study (MRID 44505010) is being downgraded to supplemental

- qualitative due to pH, solubility issues, and significant differences in bodyweights even at the lowest concentrations ( i.e., NOAEC < 97,000 ppb) , though it could not be determined from the

limited data whether these differences were treatment related since only two treatment

### Page 16 of 66



### groups had organisms surv ive to test termination with 46% inhibition at the 97,000 ppb treatment group but only 18% inhibition in the 180,000 ppb treatment group

. Additionally, n o chronic data are available for mesotrione’s effects to estuarine/marine

invertebrates. For aquati c plants, mesotrione was significantly more toxic ( two orders of magnitude) to vascular plants than to non

- vascular plants.

Mesotrione’s degradates, AMBA and MNBA, were slightly more toxic to freshwater fish

and invertebrates , though still practically non

- toxic, and were somewhat less sensitive to green algae than parent mesotrione

. No degradate data were available for the most sensitive aquatic taxa to parent mesotrione, estuarine/marine invertebrates and aquatic vascular plants.

For terrestrial animals, the available data indicate that mesotrione is practically non

- toxic

to all taxa on an acute basis

. As expected for an herbicide, mesotrione’s end

- use products appear particularly toxic to terrestrial plants. Additional detail is included in the following tables. No information is available on the toxicity of the major metabolites

, AMBA and MNBA to terrestrial plants , birds or insects, though the available data indicate that these degradates are practically non

- toxic to mammals on an acute basis

.



## 6.1. Effects to Aquatic Organisms

Table 5 . Summary of the M ost S ensitive E ndpoints from A quatic Animal T oxicity S tudies

for Mesotrione (toxicity endpoints in ppb)

Taxonomic Group Study

Type Surrogate

Species Toxicity

Value (all units in

terms of

measured

active ingredient ) Acute

Toxicity

Classification Source

(Classification )

Freshwater fish 1 Acute Rainbow Trout Oncorhynchus mykiss 96

- Hr LC 50 >

120,000 Practically

non

- toxic 44373510

(Acceptable)

Chronic (Early

Life

Stage) Fathead Minnow

Pimephales promelas 32

- Day

NOAEC =

11 ,000

LOAEC =
23,000 (Endpoint: length) N/A 44505011 (Acceptable)

Freshwater

invertebrates Acute Waterflea Daphnia magna 48

- Hr EC 50 =

840 ,000 Practically

non

- toxic 44373511

(Acceptable)

Chronic Waterflea

Daphnia magna NOAEC <

97 ,000

LOAEC =
97,000 Endpoint: Body Weight N/A 44505010 ( Supplemental

-- Qualitative )

### Page 17 of 66 Taxonomic Group Study

Type Surrogate

Species Toxicity

Value (all units in

terms of

measured

active ingredient ) Acute

Toxicity

Classification Source

(Classification )

Estuarine/marine

fish Acute Sheepshead

minnow Cyprinodon variegates 96

- Hr LC 50 >

100 ,000

NOAEC =
100,000 Practically

non

- toxic 44505007

( Supplemental

Qualitative )

Chronic No Data NOAEC =
11,000 2 N/A N/A 2

Estuarine/marine

invertebrates Acute Mysid Shrimp Mysidopsis bahia 96

- Hr LC 50 = 3,300 Slope = 1.46 Moderately

Toxic 44505008

(Acceptable)

Acute Pacific Oyster

Crassostrea gigas 48

- Hr EC 50 = 72,000 Slightly Toxic 44505009 (Acceptable)

Chronic No Data No Data N/A N/A

1 Freshwater fish may be surrogates for aquatic

- phase amphibians.

2 In the absence of additional data, the freshwater fish chronic NOAEC of 11,000 pp b will be used as a surrogate for the saltwater fish chronic endpoint.

Table 6 : Summary of Most Sensitive Aquatic Plant Toxicity Data from the Use of Mesotrione, Alone and with Adjuvants (toxicity endpoints in ppb)

Surrogate Species 

### No Adjuvant 1 

### AgriDex 2 

### Agral 90 3

VASCULAR Duckweed

Lemna gibba 114

- D EC 50 = 1 7.7

NOAEC = 7.5 EC 50 = 6.7

NOAEC = 2.4 EC 50 = 7.1

NOAEC=3.8

NON

VASCULAR Green Alga

Selenastrum capricornutum 120

- Hr EC 50 = 1900

NOAEC = 820 No Data No Data

1 The endpoints with no adjuvant were reported in the DERs for duckweed (MRID 44505123) and green algae (MRID 44505124)

2 The duckweed endpoint with the AgriDex adjuvant was reported in the DER for MRID 46562907.

3 The duckweed endpoint with the Agral 90 adjuvant was reported in the DER for MRID 46562906

.



### Ta ble 7 . Summary of the M ost S ensitive E ndpoints from the Available A quatic T oxicity

S tudies for Degradate AMBA (units in ppb)

Taxonomic Group Study

Type Surrogate

Species Toxicity Value

(all units in terms

of measured active ingredient ) Acute Toxicity

Classification Source

(Classification)

Freshwater fish 1 Acute Rainbow Trout Oncorhynchus mykiss 96

- Hr LC 50 =

150,000 Practically

non

- toxic 44901702

(Acceptable)

Freshwater

invertebrates Acute Water Flea Daphnia magna 48

- Hr EC 50 =

160,000 Practically

non

- toxic 44901704

(Acceptable)

### Page 18 of 66 Taxonomic Group Study

Type Surrogate

Species Toxicity Value

(all units in terms

of measured active ingredient ) Acute Toxicity

Classification Source

(Classification)

Aquatic plants and algae Non

vascular Green Algae

Selenastrum capricornutum 72

- Hr I C 50 = 8,900

NOAEC = 3,700 N/A 44901709 (Supplemental)

1 Freshwater fish may be surrogates for aquatic

- phase amphibians.



### Table 8 . Summary of the M ost S ensitive E ndpoints from the Available A quatic T oxicity

S tudies for Degradate MNBA (units in ppb)

Taxonomic Group Study

Type Surrogate

Species Toxicity Value

(all units in terms

of measured active ingredient ) Acute Toxicity

Classific ation Source

(Classification)

Freshwater fish 1 Acute Rainbow Trout Oncorhynchus mykiss 96

- Hr LC 50 >

120,000 Practically

non

- toxic 44901703

(Acceptable)

Freshwater

invertebrates Acute Water Flea Daphnia magna 48

- Hr EC 50 =

134,000 Practically

non

- toxic 44901705

(Acceptable)

Aquatic plants and algae 2 Non

vascular Green Algae

Selenastrum capricornutum No Data N/A No Data )

1 Freshwater fish may be surrogates for aquatic

- phase amphibians.



### Although there are no chroni c data for saltwater fish, the test chemical was not any more acutely toxic to saltwater fish than freshwater fish and the chronic freshwater fish endpoint is several orders of magnitude above the expected environmental concent rations

from recent assessments. Therefore additional c hronic data on saltwater fish would be unlikely to add significa nt value to the risk assessment. In the absence of additional data,

t he chronic freshwater fish endpoint will be used as a surrogate for chronic saltwater fish

in the risk assessment. The lack of chronic estuarine/marine invertebrate data is a major data gap . Since the mysid shrimp data suggests that estuarine/marine invertebrates are much more ( two orders of magnitude) acutely sensitive than freshwater invertebrates , the

lack of data esta blishing a definitive chronic freshwater invertebrate NOAEC is not considered a major data gap likely to add significant value to the risk assessment. If an estuarine/marine invertebrate life cycle study is submitted, than an Acute to Chronic Ratio (ACR) will be calculated and applied to the daphnid acute value to generate a new chronic daphnid endpoint for the risk assessment.

As noted above, there were issues with pH in several of the aquatic plant studies. In the

blue

- green algae study (MRID 4450512 2) the pH of the two highest treatment concentrations was very acidic (3.6

— 4.1) and precipitate was in the highest test concentration with no filtration or centrifugation of test samples. This study has been downgraded to Supplemental

— Qualitative. Howeve r, no effects were seen at the 56,000 ppb treatment level and pH was normal at this dosage . Given the difference between the

NOAEC and other aquatic plant endpoints (duckweed IC 50 

### of 17.7 ppb) as well as

### Page 19 of 66



### maximum EECs in past assessments, the lack of an acceptable blue

- green algae is not considered a major data gap and a new study is not needed

.

In the available green algae study with parent mesotrione (MRID 44505122), the algae in

the control and lowest two treatments may have grown to the extent they were at the upper bound of the test systems carrying capacity as pH in these groups was very high (9.9

— 10.0). These high pH levels are unlikely to represent actual conditions in the

environment and may hav e inhibited performance in these g roups which leads to uncertainty around the IC 50 

### estimate. This study is also being downgraded to Supplemental

— Qualitative, however, the NOAEC of 820 ppb seems valid and there is still a large difference between this valu e and either the most sensitive aquatic plant data (duckweed IC 50 

### of 17.7 ppb) and the maximum EECs from past assessments. Therefore, the lack of an acceptable green algae study is not considered a major data gap and a new study is not requested.

In the freshwater diatom study (MRID 44505121), mesotrione appeared to cause progressively increasing stimulation of cell densities with concentration (11

— 46% stimulation compared to controls) except for the very highest concentration of 96,000 ppb which experie nced a 96% decrease in cell density compared to the control plants. This study is being downgraded to Supplemental

— Quantitative. The NOAEC of 46,000 ppb from this study is considered valid and is significantly higher than other available endpoints for aqu atic plants. A new study with freshwater diatoms is not requested at this

time.

There are no data on the toxicity of the degradates, AMBA and MNBA to the most sensitive aquatic taxa to parent mesotrione, estuarine/marine invertebrates and vascular

aqua tic plants. Since mesotrione only metabolizes to AMBA in anaerobic environments, the lack of ecotoxicity data for this degradate is not considered a major data gap. In the available green algae study with the degradate MNBA (MRID 44901710), the pH in the control and four lowest treatment doses rose to high basic levels (9.5

— 10) and declined to very acidic levels (<4.5) in the three highest treatment doses. These high and low pH’s are unlikely to represent conditions in the environment and are likely to h ave impacted both control performance and each treatment level’s performance. Therefore, there is uncertainty around the IC 50 

### and NOAEC endpoints and this study is being downgraded to Supplemental

— Qualitative. This makes comparison with the green algae s tudy with parent mesotrione difficult. However, since this study had similarly high pH’s in the control and three lowest concentrations (3,300

— 10,000 ppm) and there was no inhibition in these concentrations, while the green algae study with parent mesotri one had significant inhibition at concentrations as low as 1,500 ppm , the lack of data on MNBA’s effects to aquatic plants is not considered a major data gap and new data is not requested.

For aquatic invertebrates

, since the MNBA degradate appears to be approximately 6.3x more toxic to daphnids than parent mesotrione, the lack of ecotoxicity data for the MNBA degradate to estuarine/marine invertebrates is considered a major data gap

. If the

difference in toxicities between parent mesotrione and MNBA (~6.3x) from the daphnid studies is applied to the mysid acute LD 50 

### endpoint of 3300 ppb, than an estimated mysid

### Page 20 of 66



### LD 50 

### for MNBA would be approximately 524 ppb. When compared to the maximum EECs from previous assessments (cranberry use site ; USEPA, 2013a, D 408583 ), this

estimated LD 50 

### value is < 20 times greater; therefore, there is potential for risk to endangered species. EFED ran the IEC v1.1 (Individual Effect Chance) model to quantify the potential for risk to an i ndividual organism. Using the threshold value of 0.067 (from the estimated mysid LD 50 

### value for MNBA and the highest peak EEC of 35 ppb from previous assessments) and a probit dose

- response slope of 1.46 (from the mysid acute toxicity study with parent m esiotrione), the likelihood of an effect for an individual organism is 4.3% (95% CI: 1.2%

-- 12%). The likelihood of an effect for an individual organism exposed to mesotrione without MNBA was calculated to be 1

- in

- 508 (0.2%). The submission of mysid acute data with the MNBA degradate would enable EFED to determine the action area for endangered species determinations. In the absence of this data, EFED will use the estimated LD 50 

### value described here (524 ppb) in the risk assessment, however it is uncertain whether this approach will under

- or over

- estimate

risk.

Certain adjuvants or formulations may increase the toxicity of mesotrione to plant species. Duckweed exposed to eith er the Agral 90 or AgriDex adjuvants in combination with mesotrione was approximately twice as toxic compared to mesotrione alone. The endpoints reported in previous assessments for the Agral 90 and AgriDex studies are slightly different than what is repo rted in this problem formulation. Previous assessments used the endpoints reported by the study authors in laboratory reports while this problem formulation reports endpoints from the relevant DERs (for MRIDs 46562906 & 46562907) which are slightly lower and will be used in the risk assessment.



## 6.2. Effects to Terrestrial Organisms

Table 9

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

Taxonomic Group Study

Type Surrogate

Species Toxicity Value

(all units in

terms of

measured active ingredient) Acute

Toxicity

Classification Source

(Classification)

Birds 1 Acute Bobwhite quail

Colinus virginianus 14

- d LD 50 > 2000

mg/kg

Nominal Practically

non

- toxic 44373506

(Acceptable)

Sub

- acute dietary Bobwhite quail

Colinus virginianus 8

- D LC 50 > 4,770 Practically

non

- toxic 44373507

(Acceptable)

Chronic Mallard Duck

Anas platyrhynchos 22

- Wk NOAEC =

120 ppm

LOAEC = 600

ppm Endpoint: Normal hatchlings/eggs

laid N/A 44505005 (Acceptable)

### Page 21 of 66 Taxonomic Group Study

Type Surrogate

Species Toxicity Value

(all units in

terms of

measured active ingredient) Acute

Toxicity

Classification Source

(Classification)

Mammals Acute

Oral Laboratory rat

Rattus norvegicus LD 50 > 5,000

mg/kg Practically

non

- toxic 44373512

(Acceptable)

Acute

Inhalation No Data No Data N/A N/A

Chronic Mouse

Mus musculus N OAEL = 350

ppm LOAEL = 1500

ppm ( 71.4 mg/kg

bw /day) Endpoint: Body weight in F 1 and

F 2 male pups & opaque/cloudy

eyes N/A 4450534 (Acceptable )

Insects Acute

contact Honeybee

Apis mellifera 48

- Hr LD 50 > 100

μg/bee Practically

non

- toxic 44373528

(Acceptable)

Acute

Oral Honeybee

Apis mellifera 48

- Hr LD 50 > 11

μg/bee Practically

non

- toxic 44373528

(Acceptable)

1 Birds are considered a surrogate for terrestrial phase amphibians and reptiles



### Table 10

. Summary of most sensitive terrestrial plant toxicity data from application of mesotrione, alone and with adjuvants.

No Adjuvant 1 

### AgriDex 2 

### Agral 90 2



### Most

Sensitive Species EC 25 

### /

NOAEC Most

Sensitive Species EC 25 

### /

NOAEC (or EC 05 

### ) Most

Sensitive Species EC 25 

### /

NOAEC (or EC 05 

### )



### Terrestrial Plants

– Seedling Emergence (lb a.i./A)

MONOCOT Onion 0 .028 /

0.017 Onion 0.011 /

0.006 Onion 0.016 /

0.0023

DICOT Lettuce 0 .0033 /

0.0012 Cabbage 0.0032 /

0.0007 Cabbage 0.0019 /

0.000 5



### Terrestrial Plants

– Vegetative Vigor (lb a.i./A)

MONOCOT Onion 0.0009/

0.0001 None 3 > 0.0208/

0.0208 Onion 0 .014 /

0.00695

DICOT Tomato 0.00023/

0.0001 Lettuce 0 .00051 /

0.000086 Lett uce &

Cuc umber 0 .0017 /

0.000257

1 All of these endpoints with no adjuvant were reported in the initial new use assessment, DP Barcode D253844

. 2 T hese endpoints with adjuva nts were reported in DER review memo s, either DP Barcode D318274 (MRID 46562903) or D338942 (MRID 47093501)

. 3 No monocots exhibited a reduction of  25% for any endpoint analyzed.

### Page 22 of 66



### The available data indicate that mesotrione is practically non

- toxic on an acute basis to

birds and mammals. There is no data for the effects of mesotrione to passerine birds. Passerine bird species can frequently be more sensitive than upland and waterfowl bird species

. Using T

- Rex version 1.5.2 to model mesotrione’s residues on avian dietary items, the maximum expected residues for all currently registered uses is less than 1/10 th



### the bobwhite non

- definitive LD 50 

### value. However, the EUP rate on soybeans is over three times higher than other registered use rates and would result in dietary residues greater than 1/10 th 

### the bobwhite acute endpoint. Since neither mortality nor sublethal

effects were observed in the acut e oral test (MRID 44373506), the only mortalities occurring in subacute dietary studies (MRIDs 44373507 & 44373508) did not appear to

be treatment related and expected residues are lower than 1/10 th 

### the nondefinitive bobwhite acute endpoint , the lack o f a passerine study is not considered a major data gap and a new study is not requested for the risk assessment. However, if there is an expansion of the EUP to a broader use pattern or if application rates change in the future

, than the lack of passerine data would be considered a major data gap.

Previous EFED assessments used the chronic rat study (MRID 44920801) with a LOAEL of 2,000 mg/kg

- diet ( ppm ) based on ossification . However , the most sensitive data available to the agency is a two generation study using the mouse (MRID 4450534 )

. At low doses (10

— 350 ppm), this study found tyr o sinemia , increased kidney weights and

increased incidence of oc cular discharge

. EFED does not typically use these endpoint s in

risk assessment as their direct relation to survival, growth and reproduction is uncertain

. At the highest doses (7,000 ppm) , body weight was decreased in F 1 

### generation males and females (16

- 17%) at one week, P generation females during lactation (3

-- 13%), F 1 

### generation females during gestation (9%) and F 1 

### generation females during lactation (9

— 12%). Food consumption was also reduced at this dosage for P generation females (15

— 28%) and F 1 

### generation females (10

-- 33%). The average day of preputial separation was also reduced (10 % or ~ 3 days) in the F 2 

### generation at 7000 ppm . F 1 

### and F 2 

### pup body weights were also reduced at 7,000 ppm (6

— 24% for F 1 

### pups and 9

— 20% for F 2 

### pups). Pup body weights were also significantly reduced for both male (11

- 14%) and female (9

- 14%) for F 1 

### pup weights at 1500 ppm and for male F 2 

### pup weights (8

- 10%)

. Pup weights at lower treatment levels were also significantly reduced, but with less than 10%

inhibition. Incidence of opaque or cloudy eyes was elevated in F 2 

### males at both the 7,000 ppm (30% ) and 1500 ppm (13%) . Given that significant pup body weights were observed across multiple generations and these decreases were > 10% at the 1500 ppm treatment level and the elevated occurrence of opaque/cloudy eyes (which may result in decreased

fitness for the survival, growth and reproduction of mammals in the environment) at the same treatment level, EFED will use a NOAEC of 350 ppm and a LOAEC of 1500 ppm

in the risk assessment.

No acute toxicity data are available for the mouse using either mesotrio ne or its degradates . However, there is no evidence to indicate that the compound has a greater

acute effect on mice than it does to rats.

### Page 23 of 66



### No avian toxicity data are available for mesotrione’s metabolites, MNBA and AMBA.
However, acute data are availab le for the degradates’ toxicity to rats (MRIDs 44505015 & 44505016) with both being practically non

- toxic (LD 50 

### s > 5,000 mg/kg).

The available data indicate that certain adjuvants can increase the toxicity of mesotrione to plant taxa. For vegetative vi gor, adjuvants did not appear to increase the toxicity, however for effects on seedling emergence the adjuvants did appear to increase the toxicity of mesotrione, as much as ~2

— 2.5x for Agral 90 and AgriDex, respectively, to onion seedling emergence. Al though no data are available for Typical End

- Use Product (TEP) effects to vegetative vigor, Syngenta has stated that the amount of adjuvant used in the Agral 90 and AgriDex vegetative vigor studies is “proportionally to the product as they are recommended and used by commercial applicators” (D338942). EFED raised concerns that although the percentage of adjuvant applied is consistent with label rates, the diminishing test concentrations were applied in a constant volume of water (USEPA, 2007). If the adju vant is used in the formulation to facilitate active ingredient contact with leaf surface, such facilitation may have been affected due to the greater relative proportion of carrier (water) than the label prescribes. As such uncertainty exists as to

wheth er the true extent of toxicity was identified. While a new study is not being requested at this time, the uncertainty has been highlighted.



## 6.3. Ecological Incidents

A preliminary review on April 15, 2014 of the Ecological Incident Information System (EIIS, version 2.1.1), which is maintained by the Agency’s Office of Pesticide Programs, and the Avian Monitoring Information System (AIMS), which is maintained by the American Bird Conservancy, indicates a total of 319 reported ecological incidents in the United States associated with the use of mesotrione (summarized by certainty in Table

11 with a more thorough listing by date and location in Appendix B ). All of the reported incidents associated with mesotrione involved damage to terrestrial plants and appear to be crop damage. It is unclear how many of the incidents were due to spray drift compared to other exposure routes.

All of the mesotrione incidents occurred between 2001 and 2013 (mesotrione was first registered by EPA in 2001)

. The certainty ca tegories 1 

### regarding the likelihood that the

1 The Ecological Incident Information System (EIIS) used by EPA to store incident data relies on the following certainty indices:

 Highly Probable : (residues detected in affected organisms and other lines of evidence support cause)

 Probable : (residues were not measured or the measured residues were not sufficient to be considered toxic, but pesticide was used in close proximity and would be capable of exerting such an effect)

 Possible : multiple pesticides were used in close proximity and any of them are cap able of causing such an

effect.

 Unlikely: there are no measured residues and the observed effects are not consistent with those caused by pesticides use d in the area or there was no pesticide use known in the area.

 Unrelated: effects observed in the inci dent are unrelated to pesticide use.

### Page 24 of 66



### use of mesotrione caused the 319 incidents ranged from Unlikely (5 incidents, 1.6%), Possible (116 incidents, 36.4%), and Probable (198 incidents, 46%). 184 (58%) of the

incidents were considered to be associated with the legal use of mesotrione, 29 (9%) were considered to be misuses (4 of which were identified as accidental misuses), and the legality of use was not determined in 101 (32%) of the reported incidents.

In the risk assessment, the incidents will be f urther evaluated to determine if the reported incidents represent current patterns of use for mesotrione. Examples of additional considerations are mitigation ( e.g ., reduced application rates), product cancellations, and changes in use patterns that have o ccurred since the date of the reported incidents.

Table 11 . Summary of ecological incidents associated with mesotrione use, by certainty



### Incident Type Use Type Certainty

All (excluding unlikely) Unlikely Possible Probable Highly

Probable

Plants Agricultural

Site (Misuse) 29 0 4 25 0

Agricultural

Site (Registered Use) 184 5 18 166 0

Agricultural

Site (Unknown) 101 0 94 7 0

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

- B), ‘minor plant’ (P

- B), and ‘other non

- target’ (ONT)

incidents. ‘Other non

- target’ incidents include reports of adverse ef fects to insects and other terrestrial invertebrates. For mesotrione, registrants have reported 1 minor fish and wildlife incidents, 748 minor plant incidents, and 0 other non

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

### Page 25 of 66



# 7. Exposure Pathways of Concern

The environmental fate properties and use patterns of mesotrione indicate that direct

spray onto food residu es , spray drift, leaching to ground water

, and runoff represent potential transport mechanisms of mesotrione to aquatic and terrestrial organisms

.

The Screening Tool for Inhalation Risk (STIR v.1.0) is normally used to assess the potential for risk to birds and mammals through inhalation exposure. The exposure pathways that are assessed by this tool include both droplet inhalation and vapor

- phase

inh alation. STIR, used in the problem formulation phase, is intended to determine if exposure is likely and not whether the potential for risk exists. If STIR predicts that exposure is likely, additional inhalation data may be necessary to adequately assess r isk due to the inhalation exposure pathway. However, because no data are currently available for mammalian inhalation toxicity, STIR analysis cannot be conducted for mammals exposed to mesotrione

. However, given the vapor pressure of the chemical and the acute oral toxicity data, inhalation is not deemed a likely route of exposure.

The Screening Imbi bi tion Program (SIP 1.0, Released June 15, 2010) was used to calculate an upper bound estimate of exposure using mesotrione’s solubility in water (1600 mg/L), the most sensitive acute and chronic avian toxicity endpoints ( nondefinitive

bobwhite acute LD 50 

### of > 2,000 mg/kg

- bw

, mallard chr onic NOAEC of 120 mg/kg

- diet ) and the most sensitive acute and chronic mammalian toxicity endpoints ( nondefinitive

l aboratory r at acute LD 50 

### of > 5,000 mg/kg

- bw and mouse chronic NOAEL of 10 mg/kg

bw). Drinking water exposure alone was not determined to be a potential pathway of concern for mammalian species on an acute basis , but was determined to be a potential pathway of concer n for mammalian species on a chronic basis

. For birds, drinking water exposure alone was determined to be a potential pathway of concern on both an acute and chronic basis. Potential for concern may be less than the screening tool indicates as for

acute exposures, the avian LD 50 

### used in the screening tool was nondefinitive ( i.e. “greater than”). Additionally, as described in the fate and acute ecotoxicity studies, mesotrione’s solubility is variable and may be considerably less than 1600 mg/L depending o n environmental conditions. Therefore, less of the chemical may be available for uptake in drinking water.

These conclusions are for drinking water exposure alone. The results do not take into account that when aggregated with other exposure pathways (dietary food sources, dermal, inhalation) drinking water may contribute to a total exposure that has a potential

for effects on non

- target animals and should be explored further. Be cause there is a high degree of conservatism in the SIP 1.0 exposure estimate , there is limited expectation that use scenarios not triggering a SIP 1.0 concern would contribute significantly to aggregate risks from water plus diet when a refined water expo sure model is incorporated in the actual quantitative risk assessment. Detailed information about SIP v1.0, as well as the tool, can be found on the EPA’s website at http :www.epa.gov/pesticides/science/models_pg.htm#terrestrial

.

### Page 26 of 66



### This pathway will be explored further with the development of SIP v.2.0 in the Ecologi cal Risk Assessment for mesotrione

. For a sample of the output generated by SIP v.1.0, please see Appendix C

.

Non

- target terrestrial plants may be exposed to mesotrione residues from spray drift, runoff or if residues persist on the field. Aquatic plants may also be exposed via direct contact or vascular uptake.



# 8. Analysis Plan

8.1. Stressors of Concern

8.1.1. Ecologica l Risk Assessment

The stressor of concern are mesotrione a nd mesotrione ’s major degradates, MNBA and

AMBA. Due to the limited persistence of mesotrione and similarities in toxicity of the parent and the degradates a total toxic residues ( TTR ) approach is recommended for the

risk assessment

. Because available fate studies may not allow for the TTR half

- life

calculation s and there are limited data available for the degradates, at the time of writing

a risk assessment a decision will be made whether conduct a n assessment on the TTR or

the parent and degradate s separately depending on which approach will allow for less

uncertaint y

.

8.1.2. Drinking Water

The drinking water assessments conducted to support future human health risk

assessments of mesotrione will incorporate modeling of the parent only, mesotrione

, in surface and ground water. Since the last drinking water assessment was conducted, EFED has updated its models (PRZM

- EXAMS), the drinking water modeling input parameters, and the percent crop area (PCA ) guidelines. For all modeling, the input parameters will be selected according to the current input guidelines, and where in question a conservative approach will be taken in the selection of half

- lives

. Descriptions of all

executable versions of current models for drinking water exposure can be obtained from the following URL link: http://www.epa.gov/oppefed1/models/water/

EFED will consider all ground and surface water monitoring data available to us, and will conduct a comprehensive evaluation of the data for the risk assessment.



## 8.2. Measures of Exposure

EFED will use standard available models to evaluate potential exposures to aquatic and terrestrial organisms as described at http://www.epa.gov/pesticides/science/models_db.htm

.

### Page 27 of 66



### Available Monitoring Data

M esotrione was not included in the United States Geological Survey (USGS) National

Water

- Quality Assessment (NAWQA) Program monitoring schedule.

The registrant, however, submitted monitoring study for mesotrione in surface water (MRID 47244503). The study analyzes raw and fini shed water samples collected fr om 2005

- 2007 at Community Water Systems included in the Atrazine Monitoring Program.
In raw water, the study found mesotrione concentrations of up to 2.4 ppb with primary dissipation times of one to several weeks and low levels (≤ 0.5 ppb) persisting for several

weeks beyond that. Sampling was conducted in the Midwest, primarily in Illinois, Indiana, and Ohio, and in those areas is representative of use on corn, the only registered

use at the time of sampling. The study was classified as “ unacceptable upgradable ” at the time of evaluation and was not upgrade d since then. Upon submittal of an analytical

methods and storage stability characteristics the study could be upgraded to supplemental

.

Aquatic Exposure Modeling

The models used to predict aquatic estimated environmental concentrations (EECs) are

the P esticide Root Zone Model coupled with the Exposure Analysis Modeling System (PRZM/EXAMS) and PRZM

- Groundwater (PRZM

- GW) publically available at: http://www.epa.gov/oppefed1/models/water/in dex.htm . The PRZM/EXAMS Standard Pond scenario will be used to estimate the aquatic EECs in surface water. Modeling will

be conducted for the TTR of mesotrione preferably or the parent and degradates separately. All use patterns will be assessed using standard approaches, however, applications to rooftops is a non

- standard use. Applications to rooftops will be assessed with the same method as spot treatments. That is, it is assumed residues are washed off by a minimum of 2 mm o f water for washoff stipulated in the PRZM model. The treated

area will be assumed to be 50% and impervious surface scenarios will be used

.

Terrestrial Exposure Modeling

Exposure estimates for terrestrial animals assumed to be in the target area or in a n area exposed to spray drift are derived using the T

- REX model (version 1.5.2, March 2012). This model incorporates the Kenaga nomograph, as modified by Fletcher et al . (1994), which is based on a large set of field residue data. The upper limit values f rom the nomograph represent the 95 th 

### percentile of residue values from actual field measurements (Hoerger and Kenega 1972). The Fletcher et al . (1994) modifications to the Kenaga nomograph are based on measured field residues from 249 published research p apers, including information on 118 species of plants, 121 pesticides, and 17 chemical classes.

Instead of a default 35

- day foliar dissipation rate

, an estimated f oliar dissipation half

- life will be used derived from the available magnitude residue data

. S creening level calculations have suggested that the drinking water exposure pathway may be a

### Page 28 of 66



### significant concern for birds and will be further evaluated at the time of risk assessment

with SIP v2.0.

EECs for terrestrial plants inhabiting dry and wetland areas are derived using TerrPlant (version 1.2.2, December 2006). This model uses estimates of pesticides in runoff and in spray drift to calculate EECs. EECs are based upon solubility, application rate and minimum incorporation depth in addition to typ e of formulation and method of application. The Agency is currently developing a replacement model for TerrPlant. If the replacement has been approved prior to the initiation of the risk assessment, this new

model will be used instead.

Two spray drift models, AgDisp and AgDRIFT, are used to assess exposures of aquatic

and t errestrial organisms to mesotrione deposited in terrestrial and aquatic habitats by sp ray drift. AgDrift (version 2. 1 .1 ; dated 12/29 /20 1 1) is the model most commonly used to

simulate spray drift into terrestrial and aquatic environments from a erial and ground applications. AgDisp (version 8.13; dated 12/14/2004) ( Teske and Curbishley, 2003 ) is used when a parameter needs to be modeled that is not available in AgDRIFT. Spray drift analysis will be an import ant part of the analysis in defining the potential area of effects for endangered species.

These models are parameterized using relevant reviewed environmental fate data from registrant submissions and the literature; model input values will be consisten t wit h the most recent version of EFED’s aquatic model input parameter guidance (Version 2.1; EFED 2009).



## 8.3. Measures of Effect

Toxicity data presented in Section 6 of this problem formulation will be used to calculate risk quotients. Any additional information submitted by the registrant or found in the open literature prior to conduct of the risk assessment will also be considered. The open

literature studies are identified using EPA’s ECOTOXicology database ( ECOTOX) (USEPA, 2009 ), which employs a literature search engine for locating chemical toxicity data for aquatic life, terrestrial plants, and wildlife. The evaluation of both sources of data can also provide insight into the direct and indirect effects of pesticides on biotic communities from loss of species that are sensitive to the chemicals and from changes in

structure and functional characteristics of the affected communities.



## 9. Endangered Species Assessm ents

Consistent with the Agency’s responsibility under the Endangered Species Act (ESA), the Agency will evaluate risks to federally listed threatened and/or endangered (listed) species from registered uses of pesticides in registration review

. The proces s for evaluating potential risks to listed species is further described at

### Page 29 of 66



### http://www.epa.gov/oppfead1/endanger/litstatus/riskasses.htm

. An endangered species

assessment has not b een conducted for mesotrione to date.



## 10. Endocrine Disruptor Screening Program

As required by FIFRA and FFDCA, EPA reviews numerous studies to assess potential adverse outcomes from exposure to chemicals. Collectively, these studies include acute,

subchro nic and chronic toxicity, including assessments of carcinogenicity, neurotoxicity, developmental, reproductive, and general or systemic toxicity. These studies include endpoints which may be susceptible to endocrine influence, including effects on endocrine target organ histopathology, organ weights, estrus cyclicity, sexual maturation, fertility, pregnancy rates, reproductive loss, and sex ratios in offspring. For ecological hazard assessments, EPA evaluates acute tests and chronic studies that assess growth, developmen tal and reproductive effects in different taxonomic groups. As part of the Problem Formulation for Registration Review for mesotrione

, EPA reviewed these data and selected the most sensitive endpoints for relevant risk assessment scenarios from the

existi ng hazard database. However, as required by FFDCA section 408(p), mesotrione is subject to the endocrine screening part of the Endocrine Disruptor Screening Program (EDSP).

EPA has developed the EDSP to determine whether certain substances (including

pe sticide active and other ingredients) may have an effect in humans or wildlife similar to an effect produced by a “naturally occurring estrogen, or other such endocrine effects as the Administrator may designate.” The EDSP employs a two

- tiered approach to making the statutorily required determinations. Tier 1 consists of a battery of 11 screening assays to identify the potential of a chemical substance to interact with the estrogen, androgen, or thyroid (E, A, or T) hormonal systems. Chemicals that go thr ough Tier 1 screening and are found to have the potential to interact with E, A, or T hormonal systems will proceed to the next stage of the EDSP where EPA will determine which, if any, of the Tier 2 tests are necessary based on the available data. Tier 2 testing is designed to identify any adverse endocrine

- related effects caused by the substance, and establish a

dose

- response relationship between the dose and the E, A, or T effect.

Under FFDCA section 408(p), the Agency must screen all pesticide chemica ls. Between October 2009 and February 2010, EPA issued test orders/data call

- ins for the first group of 67 chemicals, which contains 58 pesticide active ingredients and 9 inert ingredients. A second list of chemicals identified for EDSP screening was pub lished on June 14, 2013 2


### and includes some pesticides scheduled for registration review and chemicals found in

water

. Neither of these lists should be construed as a list of known or likely endocrine disruptors.

2 See http://www.regulations.gov/#!documentDetail;D=EPA

- HQ

- OPPT

- 2009

- 0477

- 0074 for the final

second list of chemicals.

### Page 30 of 66



### For further information on the status of t he EDSP, the policies and procedures, the lists of chemicals, future lists, the test guidelines and the Tier 1 screening battery, please visit our

website. 3



## 11. Preliminary Identification of Data Gaps

11.1. Environmental Fate

Table 12 identifies 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 risk assessment.

Table 12 . Submitted Environmental Fate Data for Mesotrione and its D egradates

.

OCSPP

Guideline Data

Requirement Submitted

Studies (MRID) Study

Classifications Are new

data required? Rationale for Additional Data Need

835.2120 Hydrolysis 44373529 Acceptable No Not Applicable

835.2240 Aqueous

photolysis 44537108 Acceptable No Not Applicable

835.2410 Soil photolysis 44505128 &

45196005 (addendum) Supplemental

upgradable No Not Applicable

835.4100 Aerobic soil

metabolism 44373530,

445051 3 0, (4437353 1 & 45196006),

44505 129, 44505208, (44901714, AMBA) Acceptable No Not Applicable

835.4200 Anaerobic soil

metabolism Not Available Not Available Yes An anaerobic soil metabolism study is required for soils under different pH

conditions characteristic for mesotrione

use areas

.

835.4300 Aerobic aquatic

metabolism 45196011 P a rtially Acceptable Yes The study was conducted on two British

natural water

- sediment systems in only two pH s

. T he microbial makeup of the

studied system may not be similar to the

one in the US

. A new study conducted

on US natural

- water sediment system s in variety of pH s typical in mesotrione use

area is re quested

.

3 htt p://www.epa.gov/endo/

### Page 31 of 66

Table 12 . Submitted Environmental Fate Data for Mesotrione and its D egradates

.

OCSPP

Guideline Data

Requirement Submitted

Studies (MRID) Study

Classifications Are new

data required? Rationale for Additional Data Need

835.4400 Anaerobic

aquatic

metabolism 44505131 &

44505132 Partially

Acceptable Yes The results obtained in this study are essentially the same as those from the two different aerobic aquatic systems

. This could suggest that m etabolism progresses under suboxic conditions, and may be more influenced by pH than lower oxygen content. Additional study is required to verify this as sumption.

835.1230

835.1240 Adsorption/

desorption Leaching 44505203,

44505204, 44373532,

44505201 (MNBA)

44505202 (AMBA) Acceptable No No Applicable

835.6100 Terrestrial field

dissipation (44505207 &

44505125), 44505206, (44505205 & 44505126) Supplemental No Not Applicable

850.1730 Fish

bioconcentration Not Available No ne No Bioconcentration of mesotrione and its

metabolites is not expected based on low

octanol

- to

- water partitioning ratios which

are consistent with low sorptions to soil organic matter and relatively high solubilities in water for these polar, acidic compounds. On this basis and their relative lack of persistence under aerobic conditions (which decreases opportunity

for prolonged surface exposure), the Agency is n ot requiring any formal study

of bioconcentration.

835.7100 Small

- Scale

Prospective

Ground Water Study 44901718

44901717

46562901

47020001

47106801

4741 8901 Acceptable No Not Applicable

850.6100 Analytical

method in soil 44505125,

44505126,

44505127 and

44505210 Unacceptable Yes I nadequacy was noted of soil extraction methods for aged soil. As a result the extraction and separation of mesotrione and degradates/metabolites were not reliable and quantitatively efficient.

Analytical

method in water

and sediment. 44901715

44901716 --- Yes The methods are required to support monitoring for mesotrione residues and current and newly submitted environmental fate and ecological effects

data

.

### Page 32 of 66

Table 12 . Submitted Environmental Fate Data for Mesotrione and its D egradates

.

OCSPP

Guideline Data

Requirement Submitted

Studies (MRID) Study

Classifications Are new

data required? Rationale for Additional Data Need

Not

available Surface Water

Monitoring 47244503 Unacceptable upgradable Yes This study can be upgraded to supplemental upon submittal of the analytical methods and storage stability characteristics since samples were stored up to 18 months before analysis

. Not

available Chlorination of

River Water 47578301

--- No Only preliminary review is available

.

840.1100 Droplet Size

Spectrum spray drift task

force spray drift task force

840.1200 Drift Field

Evaluation spray drift task

force spray drift task force



### Environmental Fate Data Gaps

Environmental Chemistry Methods and Associated Independent Laboratory

Validation: Guideline 850.6100 The environmental chemistry method for mesotrione residues of concern (parent plus major degradates) in soil, water, and sediment as well as independent la boratory validation of the methods are require d to support monitoring for mesotrione residues and

current and newly submitted environmental fate and ecological effects data. Independently validated analytical methods for residues in soil, water, and sedime nt, and plant material (environmental chemistry methods) submitted by the registrant are used to evaluate analyses described in submitted environmental fate and ecological effects studies. Submitted analytical methods are also used by various federal, stat e, tribal, and local agencies to detect and monitor residues that are or are suspected to be in environmental compartments from outdoor uses and accidental releases. Independent laboratory validations for submitted analytical methods are necessary to conf irm that the methods are functional and to confirm the levels of detection and quantitation reported in registrant

- prepared validations. Presently, the available methods for soil are not reliable

and of questionable value

.

Anaerobic soil metabolism for Mesotrione: Guideline 835.4200 No data are available for anaerobic soil metabolism. It is expected that mesotrione

anaerobic soil metabolism is pH dependent h ence data for soils with typical pH s for

mesotrione use area s are r ecommended.

Aerobic Aquatic Metabolism for Mesotrione : Guideline 835.43 00 Laboratory data for mesotrione are limited to two British natural water

- sediment systems with experimental pH 7.9 and 6.9. A longer half

- lives at lower aquatic system pHs might

be e xpected if the aerobic aquatic metabolism rates are system pH dependent

. In addition

, it is not certain that the microbial makeup of the British water

- sediment systems is similar

to the one in the US. Therefore, a new study conducted on U S natural

- water sediment

system at a variety of pHs typical in mesotrione use area is recommended. Study should

### Page 33 of 66



### be conducted until patterns of decline of parent and patterns of formation and decline of transformation products are established. For the purpose of modeling a very conservative approach will be taken in selecting the input parameters if the data are not available.

Anaerobic aquatic metabolism for Mesotrione: Guideline 835.4400 Currently the data for mesotrione are limited to one flooded Radford U.S. soil syste m with purified water (two radiolabels and pH 6.9 to 7) and the obtained half

- life is comparable to the aerobic soil metabolism rate, and essentially the same as those from the two different aerobic aquatic systems. These results indicate that metabolism

p rogresses under suboxic conditions, and may be more influenced by pH than lower oxygen content. If this is true, an additional study is requested to further understand mesotrione metabolism under anaerobic aquatic conditions in natural systems at a variety of pH s . Study should be conducted until patterns of decline of parent and patterns of formation and decline of transformation products are established. For the purpose of modeling a very conservative approach will be taken in selecting the input parameter s if

the data are not available.

Aerobic Soil Metabolism for MNBA: Guideline 835.4100

There are no separate aerobic soil metabolism study for MNBA alone, as there was for

AMBA , thus is not certain if there is concern for exposure from MNBA from mesotrione

use

. Fate data indicate that MNBA would be a major product in many soils in which corn is grown. (In three of seventeen aerobic soils with more neutral pHs (more desirable for growing corn), maximum concentrations of MNBA reached approximately 30, 50, and 60% of the dose.) Even though the registrant attempted to estimate half

- lives for MNBA from mesotrione metabolism data, EFED concludes that the available data are insufficient for the purpose. In at least two soils, MNBA "half

- lives" appeared to be one to several months, but much shorter in others. The submitted data will alleviate the uncertainty associated with the metabolite persistence and uncertainty with its availability in soil for potential transport to surface water. Without this data it will be a ssumed that the degradate’s aerobic soil metabolism half

- life is three times the most conservative

estimated half

- live obtained from a formation and decline curve.

Aerobic Aquatic Metabolism for MNBA: OCSPP Guideline 835.4300 The Agency has no data on th e fate of MBNA under aerobic aquatic conditions. The longer MBNA persists in the soil, the greater the opportunity for it to move into surface water, where its fate is unknown and where it potentially could impact aquatic species. Data from this study wo uld address the uncertainty in regards to MNBA behavior in the aquatic environment under aerobic conditions. The study should be conducted at a variety of pHs.

Analytical Methods with the Storage Stability Characteristics for Surface Water Monitoring (MRID 47244503) : Guideline 850.6100

Additional data are requested for the purpose of upgrading the unacceptable Surface Water Monitoring study . S urface water samples collected for the monitoring study were stored for up to 18 months before analysis. If up graded, the available surface water data

### Page 34 of 66



### could be used for qualitative characterization or used more quantitatively (chronic exposure results) in the risk assessment.

Drinking Water Treatment Method for MRID 47578301: Guideline not Available

Information on the types of treatment that were used in surface water samples from the monitoring study ( MRID 47244503 ) to obtain drinking water are requested. The surface monitoring stud y had no detections of mesotrio ne in finished water. The sampling was

conducted a t the same time and in the same locations as that for untreated water, but there is no information as to the types of treatment that were used to obtain finished water

.



## 11.2. Effects

Table 13 and Table 1 4 identify ecological effects studies by MRID that offer data for each g uideline requirement, as well as study classifications and whether or not further data are needed in order to support risk assessment.

Table 13 . Submitted Aquatic Ecological Effects Data for Mesotrione and its Degradates

OCSPP

Guideline Data

Requirement TGAI/

TEP/

Metabolite Submitted

Studies (MRID) Study

Classifications Are data

needed to

conduct

risk

assessment? Current Additional Data

Need

/Notes

850.1010 Freshwater

invertebrate acute toxicity TGAI 44373511 Acceptable No N/A

AMBA 44901704 Acceptable

MNBA 44901705 Acceptable

850.1025

850.1035

850.1045

850.1055 Saltwater

invertebrate acute toxicity TGAI 44505008 Acceptable No 1 MNBA was more toxic than parent to freshwater

invertebrates and saltwater

invertebrates were much more (~2 orders of magnitude) acutely sensitive to parent

mesotrione than freshwater

invertebrate s. An acute mysid study with the MNBA degradate is required. TGAI 44505009 Acceptable No

AMBA No Data N/A No

MNBA No Data N/A Yes 1

850.1075 Freshwater fish

acute toxicity TGAI 44373510 Acceptable No N/A

TGAI 44373509 Acceptable

AMBA 44901702 Acceptable

MNBA 44901703 Acceptable

850.1075 Saltwater fish acute

toxicity TGAI 44505007 Supplemental

— qualitative 2 No 2 None

— the study is sufficient

to indicate the LC 50 for saltwater fish is greater than 100 ppm AMBA No Data N/A

MNBA No Data N/A

850.1300 Freshwater

invertebrate TGAI 44505010 Supplemental

— Qualitative 3 No 3 3 The previously acceptable daphnid study was downgraded

### Page 35 of 66

OCSPP

Guideline Data

Requirement TGAI/

TEP/

Metabolite Submitted

Studies (MRID) Study

Classifications Are data

needed to

conduct

risk

assessment? Current Additional Data

Need

/Notes

life cycle AMBA No Data N/A due to issues with solubility, pH and inconclusive effects data. However, since the mysid is much more acutely sensitive to mesotrione, a new study is not requested. In the absence of data, EFED wil l use the mysid acute and chronic (see below) data to generate an ACR that can be applied to the daphnid acute data. MNBA No Data N/A

850.1350 Saltwater

invertebrates life cycle TGAI None N/A Yes 4 4 Since the mysid was significantly more (~2 orders of magnitude) acutely toxic than the daphnid, chronic data is required. Additionally, the results of this study will be used to generate an ACR and applied to the freshwater invertebrate acute endpoints. AMBA None N/A No

MNBA None N/A No

850.1400 Freshwater fish

early

- life stage TGAI 44505011 Acceptable No

--

AMBA No Data N/A

MNBA No Data N/A

850.1400 Saltwater fish

early

- life stage TGAI No Data N/A No 5 5 In the absence of data EPA

will use the freshwater fish ELS study endpoint as a conservative surrogate for the saltwater fish chronic endpoint. AMBA No Data N/A

MNBA No Data N/A

850.1500 Fish life cycle TGAI No Data N/A No

--

AMBA No Data N/A No

MNBA No Data N/A No

850.4400 Aquatic plant

Toxicity Test using

Lemna spp. TGAI 44505123 Acceptable No 6 Since Lemna is much more sensitive (~3 orders of magnitude) to mesotrione than the green algae, and MNBA forms in aerobic conditions, a Tier II study with Lemna using MNBA is required. TEP 46562906 Acceptable No

TEP 46562907 Acceptable No

AMBA No Data N/A No

MNBA No Data N/A Yes 6

850.4500 Algal toxicity TGAI 44505120 Acceptable No

TGAI 44505124 Supplemental

-- Qualitative No

TGAI 44505121 Supplemental

-- Quantitative No

### Page 36 of 66

OCSPP

Guideline Data

Requirement TGAI/

TEP/

Metabolite Submitted

Studies (MRID) Study

Classifications Are data

needed to

conduct

risk

assessment? Current Additional Data

Need

/Notes

AMBA 44901709 Supplemental

-- Quantitative No

MNBA 44901710 Supplemental

-- Qua litative No

850.4550 Cyanobacteria TGAI 44505122 Supplemental

-- Qualitative No

--

AMBA No Data N/A No

MNBA No Data N/A No



### Table 14 . Submitted Terrestrial Ecological Effects Data for Mesotrione.

OCSPP

Guideline Data

Requirement Submitted

Studies (MRID) Study

Classifications Are data

needed for

risk

assessment? Current Additional

Data Need

850.2100 Avian oral

toxicity 44373506 Acceptable No 1 1 A passerine acute oral study is not required due to no mortality or

sublethal effects in the

available data and EECs are expected to be lower than would trigger the study request. However, if there is an expansion of

the EUP to a broader use pattern, than the lack of passerine data would be considered a major data

gap as EECs would be high enough to trigger the study request. No Data N/A

850.2200 Avian dietary

toxicity 44373507 Acceptable No

--

44373508 Acceptable No

850.2300 Avian

reproduction 44505005 Acceptable No

44505006 Supplemental

--

Quantitative No

850.3020 Honey bee

acute contact toxicity 44373528 Acceptable No

--

850.3030 Honey bee

residue on foliage No Data N/A 

### No

--

### Page 37 of 66 OCSPP

Guideline Data

Requirement Submitted

Studies (MRID) Study

Classifications Are data

needed for

risk

assessment? Current Additional

Data Need

850.3040 Field testing

for pollinators No Data N/A 

### No

--

850.4100 Seedling

Emergence and Seedling

Growth 47093501 Acceptable No 2 Data for cabbage and onion were supplemental

3 Data for lettuce and cabbage were invalid 46562902 Supplemental 2 /

Acceptable No

46562903 Supplemental/

Invalid 3 No

44505119 Acceptable No

N/A N/A Yes 4 4 Seedling emergence data are required for

MNBA’s effects. The recommended species are

the most sensitive ones from the parent mesotrione dataset, onion (for monocot species), lettuce and cabbage.

850.4150 Vegetative

Vigor 44505119 Acceptable No

--

46592904 Acceptable No

46592905 Acceptable No



### Ecological Effects Data Gaps

 Freshwater Invertebrate Life Cycle (OCSPP Guideline 850.1300) : A submitted chronic daphnid study was previously deemed Acceptable. However, this study (MRID 44505010 ) had several issues confounding its results (including precipitates and extremely acidic conditions in high concentrations and inconsistent effects at lower concentrations) which has resulted in its downgrade to Supplemental

— Qualitative. The lack of an ac ceptable chronic freshwater invertebrate study is a data gap. However, on an acute basis the estuarine/marine invertebrate (mysid) was much more sensitive (2

- 3 orders of magnitude) to mesotrione than the freshwater invertebrate (daphnid). Previous assessm ents indicate that maximum expected environmental concentrations are substantially lower than acute freshwater invertebrate endpoints and levels of concern were not exceeded. Therefore, if a chronic mysid study is available at the time of the risk

assessm ent, an acute to chronic ratio (ACR) can be generated from the acute and chronic mysid data and applied to the acute daphnid data to estimate a chronic daphnid endpoint.

 Saltwater Invertebrate Acute Toxicity Study (OCSPP Guideline 850.1035) with the deg radates AMBA and MNBA : Mesotrione is significantly more toxic on an acute basis to estuarine/marine invertebrates compared to freshwater

### Page 38 of 66 

### invertebrates. Although data is available for the degradates toxicity to daphnids, this may underestimate their toxic ity to mysids, especially since the degradates were significantly (5

- 6) times more toxic than parent mesotrione to the daphnid. Using the toxicity differential between parent and metabolites described in the acute daphnid toxicity studies and applying this differential to the mysid acute endpoint with parent mesotrione results in acute endpoints with the degradates

that are near 1/20 th 

### the peak mesotrione EECs calculated in past assessments (USEPA, 2013; D408583). A preliminary IEC analysis conducted in th is problem formulation indicates that the chance of an effect to an individual organism is 0.2% for exposure to parent and may be up to 4.3% for the metabolites. Therefore, there is potential for risk to listed species of saltwater invertebrates.
However, since AMBA is usually produced under anaerobic conditions, it is not expected that there would be a likely exposure pathway for saltwater invertebrates in the water column and therefore, an acute mysid toxicity test with this degradate

is not requested at this time. However, the lack of an acute mysid toxicity study with MNBA remains a major data gap, and this study is requested. In the absence of this information, EPA may use the differential in the acute daphnid toxicity studies between parent mesotrio ne and the MNBA degradate to calculate an acute mysid endpoint for MNBA’s effects to saltwater invertebrates and compare that to expected MNBA EECs in the risk assessment. However, it is uncertain whether this approach would underestimate or overestimate risk to saltwater invertebrates.

 Estuarine/Marine Invertebrate Chronic Toxicity Study (OCSPP Guideline 850.1350): Mesotrione has outdoor uses that may result in exposure to

estuarine/marine invertebrates. Mysids are the most sensitive aquatic animal on a n acute basis and are significantly (~2 orders of magnitude) more sensitive than daphnids. No acceptable chronic invertebrate data is available for either freshwater or saltwater invertebrates, therefore an acute to chronic ratio (ACR) approach cannot cur rently be used. Since the mysid is significantly more acutely sensitive than the daphnid, the lack of a chronic saltwater invertebrate study is a major data gap and is more significant than the lack of a chronic freshwater invertebrate study. Therefore, EPA requests that a chronic estuarine/marine invertebrate study be submitted and endpoints from this study may also be used in an ACR approach to estimate a chronic freshwater invertebrate endpoint. In the absence of this data, risk would not be able to be precluded to estuarine/marine

invertebrates in the risk assessment.

 Estuarine/Marine Fish Early

- Life Stage Toxicity Study (OCSPP Guideline 850.1400): An estuarine/marine fish early life

- stage test using the TGAI has not been submitted, since it was not considered to be necessary based on previous risk assessments for mesotrione. An ACR approach cannot be used because the endpoints in the acute data are nondefinitive. In the absence of data EPA will use the rainbow trout early life stage data as a surr ogate for the chronic saltwater fish. Although according to the data requirement section in 40 CFR Part 158 the lack of this study is considered a data gap, the utility of a n estuarine/marine fish ELS study for the risk assessment is considered low at thi s time, given the predicted

### Page 39 of 66 

### difference between the exposure estimates from previous assessments and the toxicity estimate derived using the freshwater fish ELS study. Therefore, a n estuarine /marine fish early life stage toxicity test is not requested at th is time

.

 Acute Avian Oral Toxicity Study (OCSPP Guideline 850.2100): No data are available for passerine species, which may be more sensitive than the tested bobwhite species. However, the LD 50 

### and LC 50 

### data for the mallard and bobwhite

were all nondefin itive (“greater than”) values, and there were no sublethal effects in any acute or subacute avian study . Maximum use rates for currently registered uses of mesotrione are expected to result in residues in dietary items that are below any levels of concern for birds using the nondefinitive acute endpoints. Therefore, a passerine study is not requested at this time. However, if there is an expansion of the EUP on soybeans (which has a maximum annual application rate that is three times other currently registered uses) to a broader use pattern or if other new registrations with higher application rates become registered, than the lack of passerine data would be c onsidered a major data gap.



# 12. References

Derek Cornes, 2005

. Callisto: a very successful maize herbicide inspired by allelochemistry"

. Fourth World Congress on Alleo pathy . The Regional Institute Ltd. Retrieved May 26, 2011.

USEPA, 2001. New Chemical Review (Section 3) for the Use on Corn of the Herbicide Mesotrione (DP Barcode D253844). May, 2001. USEPA/OPPTS/OPP.

USEPA

, 2007a. Section 3 registration for new use of mesotrione on cranberries, flax, millet, and bush and cane berries (DP Barcode D325840) and on turf (DP Barcodes D333402, D333409, D333414, D333419). January, 2007.

USEPA/OPPTS/OPP.

USEPA

, 2007b. Section 3 r egistration for new use of mesotrione on asparagus, grass grown for seed, oats, okra, rhubarb, sugarcane, and sorghum (DP Barcodes D335361 and D335363). November, 2007. USEPA/OPPTS/OPP.

USEPA, 2008 a . Tier II Drinking Water Assessment for Mesotrione New Uses on Soybeans (Experimental Use Permit), Soybeans (Section 3 New Use), and Turf (Section 3 New Use). November 25, 2008. USEPA, OPP, EFED, Washington,

DC.

USEPA, 2008b. Ecological Risk Assessment for Experimental Use Permit (DP Barcode 34510) and S ection 3 New Use (DP Barcode 357888) registrations for use of mesotrione on soybeans. December 22, 2008. USEPA/OPPTS/OPP. Washington, D.C.

### Page 40 of 66



### USEPA

, 2013 a

. Environmental Fate and Ecological Risk Assessment for the Section 3 New Uses of Mesotrione (Callist o Herbicide) (DP Barcode 408583 ). September
10, 2013 . USEPA/OPPTS/OP P.

USEPA, 2013b. Mesotrione (122990) Screening Level Usage Analysis (SLUA). March
12, 2013. USEPA/OPPTS/OP P.

USEPA

, 2014

. Mesotrione: Drinking Water Exposure Assessment for New Use on

Mesotrione

- Tolerant Soybean. (DP Barcode 415369 ). April, 2014

. USEPA/OPPTS/OPP.

USEPA, 2014. BEAD Chemical Profile (BCP) for Registration Review: Mesotrione (122990). Biological and Economi c Analysis Division. Office of Pesticide Programs. U.S. Environmental Protection Agency. Arlington, VA. April 9,

2014.

## Appendix A : Label Use Information for Mesotrione (PC Code 122990) by Use Site

Use Site Formulation

Type Max Rate (lbs

a.e./Acre) Max.

No. of Apps

per Year 1 Min.

App.

Interval 2 Application

Methods Comments/

Restrictions Single Annual

Caneberry subgroup Soluble

Concentrate 0.1875 0.1875 NS 14 Broadcast

, Directed Spray Nonbearing or

Prebloom Bushberry subgroup Soluble

Concentrate 0.1875 0.1875 NS 14 Broadcast

, Directed Spray Nonbearing or

prebloom Airports/Landing

Fields Emulsifiable

Concentrate 0.25 0.5 NS 14 Broadcast

, Spot

Treatment Aerial Not

Allowed

Asparagus Soluble

Concentrate 0.2406 0.2406 NS NS Band Treatment

, Broadcast Postharvest

Blueberry Soluble

Concentrate 0.125 0.125 1 NA Broadcast Prebloom /

Aerial not

Allowed

Restricted to

Maine

Commercial/

Industrial Lawns Soluble

Concentrate,

Emulsifiable

Concentrate 0.25 0.5 NS NS (14) Broadcast, Spot Treatment, Spray

Corn (silage, unspecified, field, pop & sweet) Soluble

Concentrate,

Emulsifiable

Concentrate

, Water Dispersible

Granules 0.2406 0.2406 NS NS (14) Soil Band, Soil, Broadcast, Burndown, Directed Spray,

Soil Treatment (Surface), Spray, All have Aerial

not allowed except for label Reg. Nos 100

- 1131 on corn (unspecified) &
AR130010,

MO130001 &

MS120006 on

field corn

Cranberry Soluble

Concentrate 0.25 0.5 2 14 Broadcast, Chemigation After bud

break

Flax Soluble

Concentrate 0.1875 0.1875 1 NA Broadcast Preemergence

Golf Course Turf Emulsifiable

Concentrate,

Soluble 0.25 0.5 NS 14 Broadcast, Spot treatment, Spray Aerial not

allowed except for EPA Reg.

No. 100

- 1265Concentrate,

Granular Grasses grown

for Seed Soluble

Concentrate 0.1875 0.2813 NS NS Broadcast

Millet (pearl) Soluble

Concentrate 0.1875 0.1875 NA NA Broadcast Preemergence

Oats Soluble

Concentrate 0.1875 0.1875 1 NA Broadcast

Okra Soluble

Concentrate 0.1875 0.1875 1 NA Directed spray,

soil band

treatment Postemergence

use has a lower rate (0.938 lbs ai/A)

Ornamental

Herbaceous

Plants Emulsifiable

Concentrate,

Soluble

Concentrate 0.125 NS NS NS Broadcast Only registered

in North

Carolina and

Minnesota (lower rate in MN)

Ornamental

Lawns and Turf Emulsifiable

Concentrate 0.25 0.5 NS NS (14) Broadcast, Spot

Treatment Aerial Not

Allowed

Ornamental Sod

Farm Emulsifiable

Concentrate,

Granular 0.25 0.5 NS (2) NS (14) Broadcast, Spot

Treatment Aerial Not

Allowed except for label Reg.

No. 100

- 1265

Recreation Area

Lawns Soluble

Concentrate,

Granular 0.2493 0.495 NS (2) NS (14) Broadcast, Spray Aerial Not Allowed except for label Reg.

No. 100

- 1265

Recreation

Areas Emulsifiable

Concentrate 0.25 0.5 NS NS (14) Broadcast, Spot

Treatment Aerial Not

Allowed

Residential

Lawns Emulsifiable

Concentrate,

Soluble
Concentrate,

Branular 0.25 0.5 NS NS (14) Broadcast, Spot Treatment, Spray Aerial Not

Allowed except for label Reg.

No. 538

- 317 &

100

- 1265

Rhubarb Soluble

Concentrate 0.1875 NS NS (1) NS Broadcast Dormant, Preemergence

Sorghum Emulsifiable

Concentrate,

Soluble

Concentrate 0.2 NS (0.2) NS (1) NS Broadcast, Soil

treatment (surface), Directed Spray Aerial Not

Allowed except for label Reg.

No. 100

- 1131

Soybeans Soluble

Concentrate 0.1875 0.1875 NS NS Broadcast Preemergence

Sugarcane Soluble

Concentrate, 0.2406 0.3344 NS (2) 14 Broadcast, Spray, Directed SprayNS = Not Specified

NA = Not Applicable

1 NS (#) = Some labels did not state the max imum number of applications per year . The # in parentheses is the maximum for the labels which did provide a number.

2 NS (#) = Some labels did not state the minimum interval between applications

. The # in parentheses represents the minimum for those labels which did provide a number. Emulsifiable

Concentrate

## Appendix B : Summary Data for Mesotrione Related Incidents



# E I IS P e s t i c i de S u m m a r y R e po r t: Ge n e r al I nfo r m a t i o n

M e sot r io n e (1 2 29 9 0)

Cer t ai nt y C od e: 0 =U n rel a te d

, 1 =U nl ike l y
, 2 = P o s s ibl e, 3 = P r o b a bl e, 4 =H i g h ly P r ob a bl e.

L e g a l i t y C o d e: RU=Re g i s t e red Us e
, M = M i su s e, M A = Mi s u s e ( A cci d e n ta l ), M I = Mi s u se (I n t en t i on a l ), U=U n k no w n

.I n cident # D at e C o u n t y S t a t e Ce rta i n t y L e g a l

. F o r m ul. A pp l

. M et h od Total M a g nitu d e



### P L AN T S

A g r i c u l t u r

al a r e a

I021 4 8 5

- 0 19 A d a ir IA 2 M P o s t

- B ro ad c ast 60 .0 a c r es

I013 5 5 4

- 0 15 6 / 29 / 2 0 0 2 L a P or te IN 3 M SC Br o ad ca s t 11 3 ac r es

I018 0 3 5

- 0 85 5 / 17 / 2 0 0 6 J ac k s o n IN 3 RU Br o ad ca s t 12 6 ac r es

I020 2 8 3

- 0 57 11 / 1 / 2 0 0 7 MN 2 UN F Br o ad ca s t 12 0 ac r es

I020 2 8 3

- 0 61 11 / 1 / 2 0 0 7 IL 2 UN F Br o ad ca s t 24 0 ac r es

I020283

- 05 8 11 / 1 / 200 7 MN 2 UN F B r oadca s t 30 0 a c r es

I020 2 8 3

- 0 59 11 / 1 / 2 0 0 7 MN 2 UN F Br o ad ca s t 1 0 a c r es

I020 2 8 3

- 0 69 11 / 1 / 2 0 0 7 MN 2 UN F 6 a c r es

I020 2 8 3

- 0 85 11 / 1 / 2 0 0 7 MN 2 UN F 3 0 a c r es

I020 2 8 3

- 0 52 11 / 1 / 2 0 0 7 NE 2 UN F Br o ad ca s t 7 3 a c r es

I020 2 8 3

- 0 60 11 / 1 / 2 0 0 7 MN 2 UN F Br o ad ca s t 2 2 a c r es

I020 2 8 3

- 0 47 11 / 1 / 2 0 0 7 MN 2 UN F Br o ad ca s t 3 0 a c r es

I020283

- 05 1 11 / 1 / 200 7 NE 2 UN F B r oadca s t 4 9 acre s

I020 2 8 3

- 0 90 11 / 1 / 2 0 0 7 IA 2 UN F Br o ad ca s t 25 0 ac r es

I020 2 8 3

- 0 09 11 / 1 / 2 0 0 7 MS 3 UN F Br o ad ca s t 1 0 a c r esInci d ent # D a t e C o un t y S ta t e C erta inty L egal

. F o r m ul. A pp l

. M et h od Total M a g nitu d e

I020 2 8 3

- 0 15 11 / 1 / 2 0 0 7 WI 2 UN F Br o ad ca s t 2 2 a c r es

I020 2 8 3

- 0 67 11 / 1 / 2 0 0 7 IL 2 UN F Br o ad ca s t 8 0 a c r es

I020283

- 13 6 11 / 1 / 200 7 IA 3 UN F B r oadca s t 357 5 a cre s

I020 2 8 3

- 0 62 11 / 1 / 2 0 0 7 IL 2 UN F Br o ad ca s t 30 0 ac r es

I020 2 8 3

- 0 49 11 / 1 / 2 0 0 7 MN 2 UN F Br o ad ca s t 28 0 ac r es

I020 2 8 3

- 0 92 11 / 1 / 2 0 0 7 IN 2 UN F Br o ad ca s t 4 0 a c r es

I021 5 0 0

- 0 15 7 / 7 / 20 09 Ma co u p in IL 2 UN Br o ad ca s t 9 0 a c r es

I022 4 5 0

- 0 07 3 / 31 / 2 0 1 0 S tea r ns MN 2 UN Br o ad ca s t,

u n in c orpor ated 31 9 ac r es

I022 4 5 0

- 0 05 6 / 22 / 2 0 1 0 C a r v er MN 2 UN Br o ad ca s t 35 0 ac r es

I022 4 5 0

- 0 06 8 / 17 / 2 0 1 0 W a b as h a MN 2 UN Br o ad ca s t 2 5 a c r es

I022 4 5 0

- 0 08 9 / 24 / 2 0 1 0 S tea r ns MN 2 UN Br o ad ca s t,

u n in c orpor ated 40 0 ac r es

I022 4 5 0

- 0 03 9 / 29 / 2 0 1 0 R ic h la n d ND 2 UN Br o ad ca s t 8 2 a c r es



### A l f a lf a

I013 5 5 4

- 0 05 5 / 13 / 2 0 0 2 A D A I R IA 3 RU SC Br o ad ca s t A ll 1 5 0 a c r es

I015 7 1 3

- 0 50 8 / 18 / 2 0 0 4 Gr a n t WI 2 RU Br o ad ca s t 7 3 a c r es a f f ected

I021 5 0 0

- 0 02 10 / 5 / 2 0 0 9 Gr a n t WA 2 UN Br o ad ca s t 12 5 ac r es

I022 4 5 0

- 0 15 6 / 28 / 2 0 1 0 Mc L e o d MN 2 UN Br o ad ca s t 3 7 a c r es



### A p p l e

I013 5 5 4

- 0 06 6 / 14 / 2 0 0 2 Van B u r en MI 2 UN SC Br o ad ca s t 54 00 ac r esInci d ent # D a t e C o un t y S ta t e C erta inty L egal

. F o r m ul. A pp l

. M et h od Total M a g nitu d e

I014 5 9 7

- 0 28 5 / 26 / 2 0 0 3 Kal a m azoo MI 3 M F S pr ay 

### B e an

B e a n
, d r y 5 2 a c r es

I013 5 5 4

- 0 13 7 / 24 / 2 0 0 2 W a d e n a MN 3 M SC Br o ad ca s t 6 6 a c r es



### B e r r y
, b l a ck b e r r

y

I023 4 4 4

- 0 03 6 / 29 / 2 0 1 1 W a s h in g t o n OR 2 UN N/R B and 10 0% o f 1 4 a c r es



### C o r b

, f i e l d

I015 7 1 3

- 0 09 6 / 1 / 20 04 P eo r ia IL 2 RU Br o ad ca s t 18 5 ac r es



### C or n

I013 5 5 4

- 0 20 6 / 11 / 2 0 0 2 Ga g e NE 2 MA SC Br o ad ca s t 12 0 ac r es

I015 7 1 3

- 0 37 8 / 2 / 20 04 S te u b en IN 3 RU Br o ad ca s t 7 0 a c r es

I015 7 1 3

- 0 13 8 / 10 / 2 0 0 4 Boo n e NE 2 RU Br o ad ca s t 1 2 a c r es a f f ected

I015713

- 01 8 9 / 22 / 200 4 E ff in g h a m IL 2 RU B r oadca s t 13 6 a c r es

I015 7 1 3

- 0 61 10 / 2 2 / 2 0 0 4 IN 2 RU Br o ad ca s t 5 5 a c r es a f f ected

I016 2 9 6

- 0 01 5 / 16 / 2 0 0 5 K n o x IN 2 UN S pr ay S m all

I016 8 1 3

- 0 01 6 / 4 / 20 05 Gru n d y IL 1 RU R T U S pr ay 8 0 a c r es co r n

I016 9 2 8

- 0 01 6 / 27 / 2 0 0 5 NE 1 RU R T U S pr ay 7 5 a c r es

I016 9 0 6

- 0 01 7 / 15 / 2 0 0 5 T i pp ec a n o e IN 1 RU R T U S pr ay 10 0 ac r es

I016 9 0 3

- 0 07 7 / 21 / 2 0 0 5 IL 2 RU R T U Br o ad ca s t 7 0 a c r es p o p c or n

I016905

- 00 1 7 / 27 / 200 5 H e n dr icks IN 1 RU R T U S pra y 6 5 acre sInci d ent # D a t e C o un t y S ta t e C erta inty L egal

. F o r m ul. A pp l

. M et h od Total M a g nitu d e

I016 9 4 1

- 0 01 8 / 9 / 20 05 W i lk in MN 1 RU R T U 18 7 ac r es

I018 0 6 5

- 0 70 11 / 1 / 2 0 0 5 K o s c i u s k o IN 3 RU Br o ad ca s t 100

I018035

- 02 7 5 / 25 / 200 6 G r u n d y MO 3 RU B r oadca s t 7 0 acre s

I018 0 3 5

- 0 52 6 / 7 / 20 06 B ur e au IL 3 RU Br o ad ca s t 4 0 a c r es

I018 0 3 5

- 1 01 6 / 7 / 20 06 B ur e au IL 3 RU Br o ad ca s t 10 0 ac r es

I018 0 3 5

- 0 05 6 / 9 / 20 06 M o nr o e MI 3 RU Br o ad ca s t 4 o u t o f 6 a c r es

I018 0 3 5

- 1 19 6 / 23 / 2 0 0 6 W h i t es i d e IL 3 RU Br o ad ca s t 4 5 a c r es

I018 0 3 5

- 0 08 6 / 23 / 2 0 0 6 W h i t es i d e IL 3 RU Br o ad ca s t 12 2 ac r es

I018 0 3 5

- 0 82 7 / 11 / 2 0 0 6 C ass IL 3 RU Br o ad ca s t 8 5 a c r es

I018035

- 12 7 7 / 12 / 200 6 C o les IL 3 RU B r oadca s t 8 0 acre s

I018 0 3 5

- 0 97 7 / 12 / 2 0 0 6 Ch a m p ai g n IL 3 RU Br o ad ca s t 8 0 a c r es

I018 0 3 5

- 1 00 7 / 12 / 2 0 0 6 Ch a m p ai g n IL 3 RU Br o ad ca s t 6 0 a c r es

I018 0 3 5

- 0 98 7 / 12 / 2 0 0 6 C o les IL 3 RU Br o ad ca s t 4 0 a c r es

I018 0 3 5

- 0 16 7 / 13 / 2 0 0 6 W o o d f or d IL 3 RU Br o ad ca s t 13 0 ac r es

I018 0 3 5

- 1 10 7 / 13 / 2 0 0 6 F or d IL 3 RU Br o ad ca s t 59 .1 a c r es

I018 0 3 5

- 0 57 7 / 13 / 2 0 0 6 Mc L ean IL 3 RU Br o ad ca s t 12 5 ac r es

I018035

- 04 9 7 / 14 / 200 6 L ivi n g s to n IL 3 RU B r oadca s t 10 1 A cre s

I018 0 3 5

- 1 09 7 / 14 / 2 0 0 6 Ma r s hall IL 3 RU Br o ad ca s t 2 2 a c r es

I018 0 3 5

- 0 80 7 / 17 / 2 0 0 6 Ch a m p ai g n IL 3 RU Br o ad ca s t 8 0 a c r es

I018 0 3 5

- 0 12 7 / 17 / 2 0 0 6 Ol m s t ed MN 3 RU Br o ad ca s t 2 5 a c r esInci d ent # D a t e C o un t y S ta t e C erta inty L egal

. F o r m ul. A pp l

. M et h od Total M a g nitu d e

I018 0 3 5

- 0 06 7 / 17 / 2 0 0 6 Ol m s t ed MN 3 RU F Br o ad ca s t 10 5 ac r es

I018 0 3 5

- 1 17 7 / 18 / 2 0 0 6 C a rro ll IL 3 RU Br o ad ca s t 80 .1 a c r es

I018035

- 02 3 7 / 18 / 200 6 Cu m berl and IL 3 RU B r oadca s t 5 0 acre s

I018 0 3 5

- 0 75 7 / 19 / 2 0 0 6 P iatt IL 3 RU Br o ad ca s t 8 0 a c r es

I018 0 3 5

- 0 56 7 / 19 / 2 0 0 6 Ch a m p ai g n IL 3 RU Br o ad ca s t 7 7 a c r es

I018 0 3 5

- 0 41 7 / 21 / 2 0 0 6 MI 3 RU Br o ad ca s t 5 0 a c r es

I018 0 3 5

- 0 87 7 / 22 / 2 0 0 6 Gr a n t WI 3 RU Br o ad ca s t 5 0 a c r es

I018 0 3 5

- 1 23 7 / 22 / 2 0 0 6 R aci n e WI 3 RU Br o ad ca s t 24 7 ac r es

I018 0 3 5

- 0 74 7 / 22 / 2 0 0 6 F o nd Du L ac WI 3 RU Br o ad ca s t 8 0 a c r es

I018035

- 12 0 7 / 24 / 200 6 G ra n t WI 3 RU B r oadca s t 3 4 acre s

I018 0 3 5

- 0 46 7 / 24 / 2 0 0 6 F o nd Du L ac WI 3 RU Br o ad ca s t 6 0 a c r es

I018 0 3 5

- 0 35 7 / 25 / 2 0 0 6 L e n a w ee MI 3 RU Br o ad ca s t 5 0 a c r es

I018 0 3 5

- 0 90 7 / 25 / 2 0 0 6 S t. J os ep h IN 3 RU Br o ad ca s t 6 5 a c r es

I018 0 3 5

- 0 91 7 / 25 / 2 0 0 6 He n r y OH 3 RU Br o ad ca s t 14 4 ac r es

I018 0 3 5

- 0 30 7 / 25 / 2 0 0 6 F u l t o n OH 3 RU Br o ad ca s t 3 0 a c r es

I018 0 3 5

- 0 44 7 / 25 / 2 0 0 6 He n r y OH 3 RU Br o ad ca s t 3 0 a c r es

I018035

- 03 6 7 / 25 / 200 6 W oo d OH 3 RU B r oadca s t 3 3 acre s

I018 0 3 5

- 0 68 7 / 25 / 2 0 0 6 S t. J os ep h IN 3 RU Br o ad ca s t 1 5 a c r es

I018 0 3 5

- 0 89 7 / 25 / 2 0 0 6 W o o d OH 3 RU Br o ad ca s t 4 0 a c r es

I018 0 3 5

- 0 32 7 / 26 / 2 0 0 6 P or ter IN 3 RU Br o ad ca s t 5 0 a c r esInci d ent # D a t e C o un t y S ta t e C erta inty L egal

. F o r m ul. A pp l

. M et h od Total M a g nitu d e

I018 0 3 5

- 0 55 7 / 26 / 2 0 0 6 L a P or te IN 3 RU Br o ad ca s t 5 0 a c r es

I018 0 3 5

- 1 04 7 / 26 / 2 0 0 6 L a P or te IN 3 RU Br o ad ca s t 32 0 ac r es

I018035

- 06 6 7 / 26 / 200 6 H e n r y OH 3 RU B r oadca s t 26 9 a c r es

I018 0 3 5

- 0 96 7 / 26 / 2 0 0 6 P or ter IN 3 RU Br o ad ca s t 4 0 a c r es

I018 0 3 5

- 0 25 7 / 26 / 2 0 0 6 J as p er IN 3 RU Br o ad ca s t 7 5 a c r es

I018 0 3 5

- 0 53 7 / 26 / 2 0 0 6 E a t o n MI 3 RU Br o ad ca s t 4 7 a c r es

I018 0 3 5

- 0 73 7 / 27 / 2 0 0 6 L i v i n g s ton IL 3 RU Br o ad ca s t 26 0 ac r es

I018 0 3 5

- 0 77 7 / 27 / 2 0 0 6 K o s c i u s k o IN 3 RU Br o ad ca s t 1 0 a c r es

I018 0 3 5

- 1 14 7 / 28 / 2 0 0 6 K o s c i u s k o IN 3 RU Br o ad ca s t 30 0 ac r es

I018035

- 12 1 7 / 28 / 200 6 L a Salle IL 3 RU B r oadca s t 24 0 a c r es

I018 0 3 5

- 0 47 7 / 28 / 2 0 0 6 K o s c i u s k o IN 3 RU Br o ad ca s t 20 0 ac r es

I018 0 3 5

- 0 99 7 / 28 / 2 0 0 6 L a S alle IL 3 RU Br o ad ca s t 4 0 a c r es

I018 0 3 5

- 0 69 7 / 28 / 2 0 0 6 K o s c i u s k o IN 3 RU Br o ad ca s t 30 0 ac r es

I018 0 3 5

- 0 17 7 / 28 / 2 0 0 6 W h i t es i d e IL 3 RU Br o ad ca s t 3 2 a c r es

I018 0 3 5

- 1 16 7 / 28 / 2 0 0 6 Ma r s hall IL 3 RU Br o ad ca s t 64 0 ac r es

I018 0 3 5

- 0 09 7 / 28 / 2 0 0 6 L a S alle IL 3 RU Br o ad ca s t 3 0 o u t o f 1 00 ac r es

I018035

- 01 5 7 / 28 / 200 6 M e r c e r IL 3 RU B r oadca s t 10 0 a c r es

I018 0 3 5

- 1 25 7 / 28 / 2 0 0 6 L a S alle IL 3 RU Br o ad ca s t 5 0 a c r es

I018 0 3 5

- 1 28 7 / 28 / 2 0 0 6 P or ta g e WI 3 RU Br o ad ca s t 5 5 a c r es

I018 0 3 5

- 0 72 7 / 28 / 2 0 0 6 K o s c i u s k o IN 3 RU Br o ad ca s t 3 0 a c r esInci d ent # D a t e C o un t y S ta t e C erta inty L egal

. F o r m ul. A pp l

. M et h od Total M a g nitu d e

I018 0 3 5

- 0 10 7 / 28 / 2 0 0 6 C o l u m b i a WI 3 RU Br o ad ca s t 4 5 o u t o f 1 00 ac r es

I018 0 3 5

- 0 65 7 / 28 / 2 0 0 6 L i v i n g s ton IL 3 RU Br o ad ca s t 25 0 ac r es

I018035

- 08 8 7 / 28 / 200 6 L ivi n g s to n IL 3 RU B r oadca s t 16 5 a c r es

I018 0 3 5

- 0 84 7 / 28 / 2 0 0 6 Ma r s hall IN 3 RU Br o ad ca s t 4 0 a c r es

I018 0 3 5

- 0 70 7 / 28 / 2 0 0 6 K o s c i u s k o IN 3 RU Br o ad ca s t 6 5 a c r es

I018 0 3 5

- 1 07 7 / 28 / 2 0 0 6 W h i t es i d e IL 3 RU Br o ad ca s t 28 0

. 1 a c r es

I018 0 3 5

- 0 92 7 / 28 / 2 0 0 6 K o s c i u s k o IN 3 RU Br o ad ca s t 60 0 ac r es

I018 0 3 5

- 0 83 7 / 28 / 2 0 0 6 O g le IL 3 RU Br o ad ca s t 73 9 ac r es

I018 0 3 5

- 0 18 7 / 31 / 2 0 0 6 W h i t es i d e IL 3 RU Br o ad ca s t 20 0 ac r es

I018035

- 11 3 7 / 31 / 200 6 O g l e IL 3 RU B r oadca s t 7 0 acre s

I018 0 3 5

- 1 03 7 / 31 / 2 0 0 6 J o D a v i e s s IL 3 RU Br o ad ca s t 7 3 a c r es

I018 0 3 5

- 0 61 7 / 31 / 2 0 0 6 O g le IL 3 RU Br o ad ca s t 70 0 ac r es

I018 0 3 5

- 1 02 7 / 31 / 2 0 0 6 S te p h e n s on IL 3 RU Br o ad ca s t 18 5 ac r es

I018 0 3 5

- 1 11 7 / 31 / 2 0 0 6 E d g a r IL 3 RU Br o ad ca s t 8 0 a c r es

I018 0 3 5

- 0 07 7 / 31 / 2 0 0 6 Ve r m ili o n IL 3 RU F Br o ad ca s t 6 8 a c r es

I018 0 3 5

- 0 48 7 / 31 / 2 0 0 6 L i v i n g s ton IL 3 RU Br o ad ca s t 4 0 a c r es

I018035

- 10 8 7 / 31 / 200 6 W h itesi d e IL 3 RU B r oadca s t 10 0 a c r es

I018 0 3 5

- 0 50 7 / 31 / 2 0 0 6 C a rro ll IL 3 RU Br o ad ca s t 25 7 ac r es

I018 0 3 5

- 0 51 7 / 31 / 2 0 0 6 C a rro ll IL 3 RU Br o ad ca s t 7 2 a c r es

I018 0 3 5

- 0 64 7 / 31 / 2 0 0 6 W h i t es i d e IL 3 RU Br o ad ca s t 18 4 ac r esInci d ent # D a t e C o un t y S ta t e C erta inty L egal

. F o r m ul. A pp l

. M et h od Total M a g nitu d e

I018 0 3 5

- 0 67 7 / 31 / 2 0 0 6 Ch a m p ai g n IL 3 RU Br o ad ca s t 8 0 a c r es

I018 0 3 5

- 1 26 7 / 31 / 2 0 0 6 Ch a m p ai g n IL 3 RU Br o ad ca s t 37 .5 a c r es

I018035

- 11 2 8 / 1 / 200 6 L ivi n g s to n IL 3 RU B r oadca s t 4 0 acre s

I018 0 3 5

- 0 86 8 / 1 / 20 06 W a s h in g t o n IA 3 RU Br o ad ca s t 1 a c r e

I018 0 3 5

- 0 81 8 / 1 / 20 06 L i v i n g s ton IL 3 RU Br o ad ca s t 8 0 a c r es

I018 0 3 5

- 0 29 8 / 1 / 20 06 Ke n d all IL 3 RU Br o ad ca s t 13 6

. 1 a c r es

I018 0 3 5

- 0 93 8 / 1 / 20 06 O g le IL 3 RU Br o ad ca s t 7 8 a c r es

I018 0 3 5

- 0 14 8 / 1 / 20 06 Mc L ean IL 3 RU Br o ad ca s t 4 0 a c r es

I018 0 3 5

- 0 42 8 / 2 / 20 06 W a y ne IL 3 RU Br o ad ca s t 8 0 a c r es

I018035

- 10 6 8 / 2 / 200 6 De K a lb IL 3 RU B r oadca s t 460. 8 acre s

I018 0 3 5

- 1 18 8 / 2 / 20 06 De Kalb IL 3 RU Br o ad ca s t 29 4

. 6 a c r es

I018 0 3 5

- 0 54 8 / 2 / 20 06 De Kalb IL 3 RU Br o ad ca s t 14 4 ac r es

I018 0 3 5

- 0 59 8 / 2 / 20 06 L a S alle IL 3 RU Br o ad ca s t 5 8 a c r es

I018 0 3 5

- 0 38 8 / 3 / 20 06 IL 3 RU Br o ad ca s t 3 0 a c r es

I018 0 3 5

- 0 11 8 / 3 / 20 06 F o nd Du L ac WI 3 RU Br o ad ca s t 7 5 a c r es

I018 0 3 5

- 0 62 8 / 4 / 20 06 C o l u m b i a WI 3 RU Br o ad ca s t 8 5 a c r es

I016903

- 00 5 8 / 8 / 200 6 G ra n t WI 2 RU R T U B r oadca s t 2 7 acre s co r n se e d

I018 0 3 5

- 0 78 8 / 9 / 20 06 Ma r s hall IN 3 RU Br o ad ca s t 20 0 ac r es

I018 0 3 5

- 0 40 8 / 9 / 20 06 He n d e r s o n IL 3 RU Br o ad ca s t 5 0 a c r es

I018 0 3 5

- 0 28 8 / 9 / 20 06 K o s c i u s k o IN 3 RU Br o ad ca s t 3 2 a c r esInci d ent # D a t e C o un t y S ta t e C erta inty L egal

. F o r m ul. A pp l

. M et h od Total M a g nitu d e

I018 0 3 5

- 0 13 8 / 14 / 2 0 0 6 De Kalb IL 3 RU Br o ad ca s t 50 .0 a c r es

I018 0 3 5

- 0 76 8 / 22 / 2 0 0 6 S t. C ha r les MO 3 RU Br o ad ca s t 4 0 a c r es

I018035

- 06 3 8 / 24 / 200 6 M a r s hall IN 3 RU B r oadca s t 7 5 acre s

I018 0 3 5

- 0 60 8 / 24 / 2 0 0 6 Ma r s hall IN 3 RU Br o ad ca s t 16 0 ac r es

I018 0 3 5

- 1 05 8 / 24 / 2 0 0 6 Ma r s hall IN 2 RU Br o ad ca s t 6 0 a c r es

I018 0 3 5

- 1 15 8 / 24 / 2 0 0 6 K o s c i u s k o IN 3 RU Br o ad ca s t 3 5 a c r es

I018 0 3 5

- 0 37 8 / 29 / 2 0 0 6 H u r on OH 3 RU Br o ad ca s t 2 0 a c r es

I018 0 3 5

- 0 79 8 / 30 / 2 0 0 6 F u l t o n OH 3 RU Br o ad ca s t 2 5 a c r es

I018 0 3 5

- 0 26 8 / 30 / 2 0 0 6 Van B u r en MI 3 RU Br o ad ca s t 20 2 ac r es

I018035

- 04 5 8 / 30 / 200 6 IL 3 RU B r oadca s t 8 4 acre s

I018 0 3 5

- 0 43 8 / 30 / 2 0 0 6 Ka n k a kee IL 3 RU Br o ad ca s t 3 9 a c r es

I018 0 3 5

- 0 33 8 / 30 / 2 0 0 6 Ka n k a kee IL 3 RU Br o ad ca s t 12 0 ac r es

I018 0 3 5

- 1 22 8 / 30 / 2 0 0 6 Hi l l s d ale MI 3 RU Br o ad ca s t 2 4 a c r es

I018 0 3 5

- 0 34 8 / 30 / 2 0 0 6 Ka n k a kee IL 3 RU Br o ad ca s t 9 3 a c r es

I018 0 3 5

- 0 39 8 / 31 / 2 0 0 6 H u r on OH 3 RU Br o ad ca s t 4 2 a c r es

I018 0 3 5

- 0 24 8 / 31 / 2 0 0 6 M or g an IL 3 RU Br o ad ca s t 1 0 a c r es

I018035

- 03 1 8 / 31 / 200 6 M a co u p in IL 3 RU B r oadca s t 1 5 acre s

I018 0 3 5

- 0 71 9 / 5 / 20 06 T aze w ell IL 3 RU Br o ad ca s t 8 0 a c r es

I018 0 3 5

- 1 24 10 / 9 / 2 0 0 6 C o l u m b i a WI 3 RU Br o ad ca s t 20 0 ac r es

I018 0 3 5

- 0 95 10 / 9 / 2 0 0 6 D od g e WI 3 RU Br o ad ca s t 20 0 ac r esInci d ent # D a t e C o un t y S ta t e C erta inty L egal

. F o r m ul. A pp l

. M et h od Total M a g nitu d e

I018 0 3 5

- 0 94 10 / 9 / 2 0 0 6 R o ck WI 3 RU Br o ad ca s t 5 0 a c r es

I018 0 3 5

- 0 58 10 / 1 2 / 2 0 0 6 Ma r s hall IN 3 RU Br o ad ca s t 30 0 ac r es

I019130

- 02 9 6 / 10 / 200 7 L o u isa IA 2 UN B r oadca s t 21 0 a c r es

I019 1 3 0

- 0 39 6 / 21 / 2 0 0 7 L ee IL 2 UN Br o ad ca s t 59 .7 a c r es

I018 1 3 0

- 0 51 7 / 19 / 2 0 0 7 Valley NE 2 UN Br o ad ca s t 8 2 a c r es

I021 5 0 0

- 0 20 12 / 2 / 2 0 0 8 Ma d i s o n IN 2 UN Br o ad ca s t 4 8 a c r es

I021 5 0 0

- 0 10 5 / 31 / 2 0 0 9 C a r v er MN 2 UN Br o ad ca s t 50 0 ac r es

I021 5 0 0

- 0 13 6 / 15 / 2 0 0 9 O g le IL 2 UN Br o ad ca s t 1 8 a c r es

I021 5 0 0

- 0 14 7 / 7 / 20 09 S ib l ey MN 2 UN Br o ad ca s t 7 4 a c r es

I021500

- 01 1 7 / 17 / 200 9 H o lt NE 2 UN B r oadca s t 10 0 a c r es

I022 4 5 0

- 0 14 6 / 14 / 2 0 1 0 Ke ar n ey NE 2 UN Br o ad ca s t 15 1 a c r es

I022 4 5 0

- 0 16 10 / 2 5 / 2 0 1 0 Ru sh IN 2 UN Br o ad ca s t 29 0 ac r es

I025 4 5 8

- 0 18 6 / 21 / 2 0 1 3 Mills IA 3 M t o tal g a rd en y ell o w



### f i e l d

I015 7 1 3

- 0 27 Del a w a r e IA 3 RU Br o ad ca s t 6 5 a c r es a f f ected

I015 7 1 3

- 0 66 5 / 25 / 2 0 0 4 P o s ey IN 2 RU B and 6 0 a c r es a f f ected

I015 7 1 3

- 0 65 5 / 25 / 2 0 0 4 K n o x IN 2 RU Br o ad ca s t 3 8 a c r es a f f ected

I015 7 1 3

- 0 67 5 / 28 / 2 0 0 4 He n r y IL 2 RU Br o ad ca s t 25 0 ac r es a f f ected

I015 7 1 3

- 0 10 6 / 1 / 20 04 P eo r ia IL 2 RU Br o ad ca s t 4 6 a c r es a f f ected

I015 7 1 3

- 0 68 6 / 24 / 2 0 0 4 Boo n e NE 2 RU Br o ad ca s t 14 0 ac r es a f f ected 

### C o r n
,Inci d ent # D a t e C o un t y S ta t e C erta inty L egal

. F o r m ul. A pp l

. M et h od Total M a g nitu d e

I015 7 1 3

- 0 25 6 / 25 / 2 0 0 4 VA 3 RU Br o ad ca s t 6 a c r es

I015 7 1 3

- 0 69 6 / 30 / 2 0 0 4 He n r y IL 2 RU Br o ad ca s t 26 0 ac r es a f f ected

I015713

- 02 6 6 / 30 / 200 4 D e la w ar e IA 3 RU B r oadca s t 53 3 a c r es

I015 7 1 3

- 0 70 7 / 1 / 20 04 Kal a m azoo MI 2 RU Br o ad ca s t 7 5 a c r es a f f ected

I015 7 1 3

- 0 71 7 / 2 / 20 04 Kal a m azoo MI 2 RU Br o ad ca s t 23 2 ac r es a f f ected

I015 7 1 3

- 0 72 7 / 19 / 2 0 0 4 MO 2 RU Br o ad ca s t 5 0 a c r es a f f ected

I015 7 1 3

- 0 73 7 / 21 / 2 0 0 4 Vi g o IN 2 RU Br o ad ca s t 16 0 ac r es a f f ected

I015 7 1 3

- 0 36 7 / 27 / 2 0 0 4 MD 3 RU N/R 2 4 a c r es a f f ected

I015 7 1 3

- 0 11 7 / 30 / 2 0 0 4 S ac IA 2 RU Br o ad ca s t 7 5 a c r es a f f ected

I015713

- 07 4 8 / 2 / 200 4 J o h nson IA 2 RU B r oadca s t 1 5 acre s a f f ec ted

I015 7 1 3

- 0 16 8 / 13 / 2 0 0 4 B u ff alo NE 2 RU Br o ad ca s t 5 0 a c r es a f f ected

I016 9 0 8

- 0 01 7 / 8 / 20 05 J ay IN 2 MA R T U S pr ay 5 0 a c r es

I016 9 0 3

- 0 04 7 / 18 / 2 0 0 5 Boo n e NE 2 RU R T U Br o ad ca s t 7 5 a c r es o f co r n

I021 5 0 0

- 0 03 7 / 2 / 20 09 Bo n H o mm e SD 2 UN Br o ad ca s t 7 8 a c r es

I022 0 8 2

- 0 38 6 / 8 / 20 10 P l ym o u th IA 2 UN Br o ad ca s t 10 0% o f 1 6 0 a c r es



### swe e t

I016 9 0 3

- 0 06 6 / 25 / 2 0 0 5 M o w er MN 2 RU R T U Br o ad ca s t 23 0 ac r es c or n

I021 5 0 0

- 0 04 7 / 16 / 2 0 0 9 F r ee b or n MN 2 UN Br o ad ca s t 2 4 a c r es 

### C o r n
,

N / R

I013 5 5 4

- 0 12 5 / 27 / 2 0 0 2 Da k o ta MN 3 M SC Br o ad ca s t 15 72 ac r esInci d ent # D a t e C o un t y S ta t e C erta inty L egal

. F o r m ul. A pp l

. M et h od Total M a g nitu d e

I013 5 5 4

- 0 18 6 / 12 / 2 0 0 2 S T J O S EP H MI 3 M SC Br o ad ca s t 28 5 ac r es

I013 5 5 4

- 0 19 6 / 19 / 2 0 0 2 K A NDIYOHI MN 3 M SC Br o ad ca s t 3 7 a c r es o u t of 80

I013554

- 01 7 6 / 20 / 200 2 SH E R B U R NE MN 3 M SC B r oadca s t 7 2 acre s

I013 5 5 4

- 0 14 6 / 29 / 2 0 0 2 L a P or te IN 3 M SC Br o ad ca s t 3 0 a c r es

I013 5 5 4

- 0 16 6 / 29 / 2 0 0 2 L a P or te IN 3 M SC Br o ad ca s t 6 0 a c r es

I013 5 5 4

- 0 11 7 / 21 / 2 0 0 2 C al h o un IA 3 MA SC Br o ad ca s t 14 4 ac r es

I013 5 5 4

- 0 21 9 / 10 / 2 0 0 2 L a P or te IN 3 MA SC Br o ad ca s t 49 8 ac r es

I014 5 9 7

- 0 13 4 / 10 / 2 0 0 3 R o ck WI 3 M R T U 15 0 ac r es

I014 5 9 7

- 0 14 5 / 1 / 20 03 K o s c i u s k o IN 2 M R T U 8 0 a c r es

I014597

- 01 2 5 / 12 / 200 3 Fu l t o n IN 3 M R T U 10 0 a c r es



### P e a

I013 5 5 4

- 0 09 4 / 22 / 2 0 0 2 Mas o n IL 3 UN SC Br o ad ca s t 15 6 ac r es

I014 5 9 7

- 0 30 4 / 22 / 2 0 0 3 Nic o l l et MN 3 M F S pr ay 60 ac r es

I014 5 9 7

- 0 29 4 / 28 / 2 0 0 3 W at o n w an MN 3 M F S pr ay 12 0 ac r es

I014 5 9 7

- 0 32 5 / 2 / 20 03 Br o w n MN 3 M F S pr ay 3 0 a c r es

I014 5 9 7

- 0 33 5 / 3 / 20 03 F a r ib a u l t MN 3 M F S pr ay 3 8 a c r es



### P o t a t o

I013 5 5 4

- 0 10 7 / 3 / 20 02 T a m a IA 3 UN SC Br o ad ca s t 34 2 ac r es



### S o y b e an

I013 5 5 4

- 0 07 6 / 21 / 2 0 0 2 Ma r s hall IA 3 RU SC Br o ad ca s t 17 4 ac r esInci d ent # D a t e C o un t y S ta t e C erta inty L egal

. F o r m ul. A pp l

. M et h od Total M a g nitu d e

I015 7 1 3

- 0 24 6 / 18 / 2 0 0 4 H o lt NE 3 RU Br o ad ca s t 18 0 ac r es

I015 7 1 3

- 0 30 7 / 1 / 20 04 MN 3 RU Br o ad ca s t 17 0 ac r es a f f ected

I015713

- 03 1 7 / 9 / 200 4 M ills IA 3 RU B r oadca s t 7 4 acre s a f f ec ted

I015 7 1 3

- 0 32 7 / 13 / 2 0 0 4 E m m et IA 3 RU Br o ad ca s t 8 5 a c r es a f f ected

I015 7 1 3

- 0 33 7 / 14 / 2 0 0 4 C al h o un IA 3 RU Br o ad ca s t 15 5 ac r es a f f ected

I015 7 1 3

- 0 34 7 / 19 / 2 0 0 4 Des M o i n es IA 3 RU Br o ad ca s t 9 0 a c r es a f f ected

I015 7 1 3

- 0 35 7 / 26 / 2 0 0 4 Ot s e g o MI 3 RU Br o ad ca s t 6 0 a c r es

I015 7 1 3

- 0 38 8 / 2 / 20 04 Br o w n NE 3 RU Br o ad ca s t 13 0 ac r es a f f ected

I015 7 1 3

- 0 39 8 / 2 / 20 04 H o lt NE 3 RU Br o ad ca s t 71 .7 a c r es a f f ected

I015713

- 01 4 8 / 10 / 200 4 A lle g a n MI 2 RU B r oadca s t 2 0 acre s a f f ec ted

I015 7 1 3

- 0 46 8 / 12 / 2 0 0 4 Mi n n e ha h a SD 3 RU Br o ad ca s t 3 5 a c r es a f f ected

I015 7 1 3

- 0 15 8 / 12 / 2 0 0 4 C a r v er MN 2 RU Br o ad ca s t 12 0 ac r es a f f ected

I015 7 1 3

- 0 45 8 / 12 / 2 0 0 4 Mi n n e ha h a SD 3 RU Br o ad ca s t 30 0 ac r es a f f ected

I015 7 1 3

- 0 42 8 / 12 / 2 0 0 4 Mi n n e ha h a SD 3 RU Br o ad ca s t 4 5 a c r es a f f ected

I015 7 1 3

- 0 43 8 / 12 / 2 0 0 4 Mi n n e ha h a SD 3 RU Br o ad ca s t 2 0 a c r es a f f ected

I015 7 1 3

- 0 41 8 / 12 / 2 0 0 4 I n g h am MI 3 RU Br o ad ca s t 6 0 a c r es a f f ected

I015713

- 04 0 8 / 12 / 200 4 MI 3 RU B r oadca s t 8 0 acre s a f f ec ted

I015 7 1 3

- 0 44 8 / 12 / 2 0 0 4 Mi n n e ha h a SD 3 RU Br o ad ca s t 20 0 ac r es a f f ected

I015 7 1 3

- 0 12 8 / 13 / 2 0 0 4 P o w e s h i ek IA 2 RU Br o ad ca s t 3 2 a c r es a f f ected

I015 7 1 3

- 0 47 8 / 16 / 2 0 0 4 C e d ar IA 3 RU Br o ad ca s t 9 8 a c r es a f f ectedInci d ent # D a t e C o un t y S ta t e C erta inty L egal

. F o r m ul. A pp l

. M et h od Total M a g nitu d e

I015 7 1 3

- 0 78 8 / 16 / 2 0 0 4 A l l a m a k ee IA 3 RU Br o ad ca s t 3 9 a c r es a f f ected

I015 7 1 3

- 0 76 8 / 16 / 2 0 0 4 C la y t o n IA 3 RU Br o ad ca s t 8 a c r es

I015713

- 07 7 8 / 16 / 200 4 C la y t o n IA 3 RU B r oadca s t 9 acre s

I015 7 1 3

- 0 48 8 / 17 / 2 0 0 4 W o o db u r y IA 3 RU Br o ad ca s t 1 6 a c r es a f f ected

I015 7 1 3

- 0 49 8 / 18 / 2 0 0 4 L a f a y ette WI 3 RU Br o ad ca s t 6 3 a c r es a f f ected

I015 7 1 3

- 0 51 8 / 18 / 2 0 0 4 Io w a WI 3 RU Br o ad ca s t 22 5 ac r es a f f ected

I015 7 1 3

- 0 52 8 / 18 / 2 0 0 4 F r a nk lin NE 3 RU Br o ad ca s t 7 8 a c r es a f f ected

I015 7 1 3

- 0 53 8 / 18 / 2 0 0 4 L ac q u i P a r le MN 3 RU Br o ad ca s t 16 0 ac r es a f f ected

I015 7 1 3

- 0 17 8 / 19 / 2 0 0 4 G oo dh u e MN 2 RU Br o ad ca s t 6 9 a c r es a f f ected

I015713

- 07 9 8 / 19 / 200 4 Fill m or e MN 3 RU B r oadca s t 9 0 acre s a f f ec ted

I015 7 1 3

- 0 54 8 / 19 / 2 0 0 4 R o ck WI 3 RU Br o ad ca s t 2 0 a c r es a f f ected

I015 7 1 3

- 0 57 8 / 20 / 2 0 0 4 Mi n n e ha h a SD 3 RU

Br o ad ca s t 7 5 ac r es a ff ected

I015 7 1 3

- 0 56 8 / 20 / 2 0 0 4 Mi n n e ha h a SD 3 RU Br o ad ca s t 5 5 a c r es a f f ected

I015 7 1 3

- 0 55 8 / 20 / 2 0 0 4 F r e m ont IA 3 RU Br o ad ca s t 8 0 a c r es a f f ected

I015 7 1 3

- 0 59 10 / 2 1 / 2 0 0 4 M o n tg o m e r y IA 3 RU Br o ad ca s t 20 0 ac r es a f f ected

I015 7 1 3

- 0 58 10 / 2 1 / 2 0 0 4 Mills IA 3 RU Br o ad ca s t 18 5 ac r es a f f ected

I015 7 1 3

- 0 60 10 / 2 1 / 2 0 0 4 M o n tg o m e r y IA 3 RU Br o ad ca s t 22 0 ac r es a f f ected

I015 7 1 3

- 0 62 10 / 2 6 / 2 0 0 4 C o l u m bus WI 3 RU Br o ad ca s t 5 4 a c r es a f f ected

I015 7 1 3

- 0 64 10 / 2 6 / 2 0 0 4 Da n e WI 3 RU Br o ad ca s t 1 3 a c r es a f f ected

I015 7 1 3

- 0 63 10 / 2 6 / 2 0 0 4 C o l u m bus WI 3 RU Br o ad ca s t 20 0 ac r esInci d ent # D a t e C o un t y S ta t e C erta inty L egal

. F o r m ul. A pp l

. M et h od Total M a g nitu d e

I019 1 3 0

- 0 34 6 / 14 / 2 0 0 7 L ee IL 2 UN Br o ad ca s t 6 9 a c r es

I019 1 3 0

- 0 37 6 / 18 / 2 0 0 7 Mc L ean IL 3 UN Br o ad ca s t 21 7 ac r es

I019130

- 04 0 6 / 21 / 200 7 L e e IL 2 UN B r oadca s t 3 0 acre s

I019 1 3 0

- 0 43 6 / 26 / 2 0 0 7 Wr i g ht MN 2 UN Br o ad ca s t 6 5 a c r es

I019 1 3 0

- 0 44 6 / 29 / 2 0 0 7 F a r ib a u l t MN 2 UN Br o ad ca s t 4 0 a c r es

I019 1 3 0

- 0 46 7 / 3 / 20 07 A d a m s IA 2 UN Br o ad ca s t 43 8

. 8 a c r es

I019 1 3 0

- 0 54 7 / 25 / 2 0 0 7 Ot t er T ail MN 2 UN Br o ad ca s t 5 5 a c r es

I019 1 3 0

- 0 55 7 / 26 / 2 0 0 7 M orr i s o n MN 2 UN Br o ad ca s t 13 5 ac r es

I019 1 3 0

- 0 90 7 / 26 / 2 0 0 7 L i v i n g s ton IL 2 UN Br o ad ca s t 20 0 ac r es

I019130

- 08 9 7 / 26 / 200 7 L ivi n g s to n IL 2 UN B r oadca s t 20 0 a c r es

I019 1 3 0

- 0 88 7 / 26 / 2 0 0 7 Mc L ean IL 2 UN Br o ad ca s t 60 ac r es

I019 1 3 0

- 0 64 8 / 24 / 2 0 0 7 M o u l tr i e IL 3 UN Br o ad ca s t 6 3 a c r es

I019 1 3 0

- 0 85 10 / 2 3 / 2 0 0 7 L i n n IA 2 UN Br o ad ca s t 3 4 a c r es

I021 5 0 0

- 0 18 11 / 1 9 / 2 0 0 8 C l i n t o n MI 2 UN Br o ad ca s t 50 0 ac r es

I021 5 0 0

- 0 17 7 / 24 / 2 0 0 9 C l i n t o n MI 2 UN Br o ad ca s t 3 0 a c r es

I021 5 0 0

- 0 16 7 / 24 / 2 0 0 9 S h i a w as s ee MI 2 UN Br o ad ca s t 4 0 a c r es

I021500

- 00 6 8 / 2 / 200 9 W i n o n a MN 2 UN B r oadca s t 16 0 a c r es

I021 5 0 0

- 0 12 9 / 21 / 2 0 0 9 N ob le IN 2 UN Br o ad ca s t 20 0 ac r es

I021 5 0 0

- 0 19 9 / 21 / 2 0 0 9 De Kalb IN 2 UN Br o ad ca s t 20 0 ac r es

I022 4 5 0

- 0 17 3 / 31 / 2 0 1 0 Ot t er T ail MN 2 UN Br o ad ca s t,

u n in c orpor ated 1

, 2 0 0 a c r esInci d ent # D a t e C o un t y S ta t e C erta inty L egal

. F o r m ul. A pp l

. M et h od Total M a g nitu d e

I013 5 5 4

- 0 08 6 / 14 / 2 0 0 2 P eo r ia IL 3 UN SC Br o ad ca s t

I015 2 8 5

- 0 13 6 / 28 / 2 0 0 4 NC 2 UN I022 4 5 0

- 0 04 10 / 1 9 / 2 0 1 0 W a s h in g t o n WI 2 UN Br o ad ca s t 3

, 3 0 0 a c r es

I023 4 4 4

- 0 04 8 / 6 / 20 11 L e S u e u r MN 2 UN N/R Br o ad ca s t 10 0% o f 9 0 a c r es



### S o y b e a n s

I014 5 9 7

- 0 20

I014 5 9 7

- 0 21

I014 5 9 7

- 0 15

I014 5 9 7

- 0 19

I014 5 9 7

- 0 18

I014 5 9 7

- 0 16

I014 5 9 7

- 0 17

I015 7 1 3

- 0 29

I015 7 1 3

- 0 28

I015 7 1 3

- 0 75



### S o y b e na 4 / 26 / 2 0 0 3

5 / 2 / 20 03

5 / 13 / 2 0 0 3

5 / 18 / 2 0 0 3

5 / 20 / 2 0 0 3

5 / 30 / 2 0 0 3

6 / 10 / 2 0 0 3

7 / 1 / 20 04

7 / 7 / 20 04

8 / 12 / 2 0 0 4 K o s c i u s k o

Ma r s hall

Da n e

P or ter

S auk

B e rr ien

K n o x

Br o w n

C lay

Mi n n e ha h a I N 3 M S C S pr ay 14 5 ac r es

I N 3 M S C S pr ay 8 0 a c r es

W I 3 M S C S pr ay 1 a c r e

I N 3 M S C S pr ay 10 0 ac r es

W I 3 M S C S pr ay 2 8 a c r es

M I 3 M S C S pr ay 5 0 a c r es

I N 3 M S C S pr ay 7 8 a c r es

NE 3 R U Br o ad ca s t 15 0 ac r es

I A 3 R U Br o ad ca s t 7 5 a c r es

S D 3 R U Br o ad ca s t 2 0 a c r es a f f ected

I021500

- 00 5 6 / 22 / 200 9 D a k o ta MN 2 UN B r oadca s t 83 % o f tr ea ted

acres



### T r e e

U n k n own 2

U n k n o w nInci d ent # D a t e C o un t y S ta t e C erta inty L egal

. F o r m ul. A pp l

. M et h od Total M a g nitu d e 

### TE RR EST R I ALInci d ent # D a t e C o un t y S ta t e C erta inty L egal

. F o r m ul. A pp l

. M et h od Total M a g nitu d e



### C or n

I023 4 4 4

- 0 32 11 / 1 / 2 0 1 0 W a b ash IL 2 UN N/R Br o ad ca s t 46 % of 1 2 0 a c r es

I023 4 4 4

- 0 30 11 / 1 / 2 0 1 0 Du P a g e IL 2 UN N/R Br o ad ca s t 10 0% o f 4 5 a c r es

I023 4 4 4

- 0 31 11 / 8 / 2 0 1 0 S T

. CR OIX WI 2 UN N/R Br o ad ca s t 10 0% o f 1 4 1 a c r es

I023 4 4 4

- 0 29 11 / 2 4 / 2 0 1 0 Mi a m i IN 2 UN N/R Br o ad ca s t 70 % of 2 5 0 a c r es

I023 4 4 4

- 0 23 6 / 6 / 20 11 P o s ey IN 2 UN N/R Br o ad ca s t 10 0% o f 1 2 3 a c r es

I023 4 4 4

- 0 27 6 / 6 / 20 11 E d w a rd s IL 2 UN N/R Br o ad ca s t 50 % of 80 ac r es

I023 4 4 4

- 0 24 6 / 6 / 20 11 Da v iess IN 2 UN N/R Br o ad ca s t 10 0% o f 2 3 2 a c r es

I023 4 4 4

- 0 14 6 / 13 / 2 0 1 1 S ta r k IL 2 UN Br o ad ca s t 10 0% o f 3 0 a c r es

I023 4 4 4

- 0 16 6 / 13 / 2 0 1 1 Ma r s hall IL 2 UN Br o ad ca s t 10 0% o f 1

, 5 0 0

acres

I023 4 4 4

- 0 13 6 / 13 / 2 0 1 1 L e S u e u r MN 2 UN Br o ad ca s t 10 0% o f 2 5 a c r es

I023 4 4 4

- 0 15 6 / 13 / 2 0 1 1 Ma r s hall IL 2 UN Br o ad ca s t 10 0% o f 4 0 0 a c r es

I023444

- 02 0 6 / 14 / 201 1 Gi b s o n IN 2 UN B r oadca s t 100 % o f 5 0 acre s

I023 4 4 4

- 0 25 6 / 14 / 2 0 1 1 Da v iess IN 2 UN N/R Br o ad ca s t 89 % of 90 ac r es

I023 4 4 4

- 0 17 6 / 28 / 2 0 1 1 P eo r ia IL 2 UN Br o ad ca s t 10 0% o f 4 0 0 a c r es

I023 4 4 4

- 0 18 7 / 25 / 2 0 1 1 F il l m or e IL 2 UN Br o ad ca s t 50 % of 1 0 0 a c r es

I023 4 4 4

- 0 28 8 / 6 / 20 11 W a u p aca WI 2 UN N/R Br o ad ca s t 50 % of 16 ac r es

I023 4 4 4

- 0 19 8 / 22 / 2 0 1 1 Ma r i o n OH 2 UN Br o ad ca s t 10 0% o f 3 3 a c r es

I023 4 4 4

- 0 33 9 / 12 / 2 0 1 1 L a w r e n ce IL 2 UN N/R Br o ad ca s t 91 % of 1 6 0 a c r es

I023444

- 02 1 10 / 20/201 1 K o sci u s k o IN 2 UN N/R B r oadca s t 10 0 % o f 6 0 a c er sInci d ent # D a t e C o un t y S ta t e C erta inty L egal

. F o r m ul. A pp l

. M et h od Total M a g nitu d e



### C or n f i el d

I022 5 2 9

- 0 07



### C o r n
, f i e l d

I022 2 0 2

- 0 72



### S o r g hum 6 / 11 / 2 0 1 0

7 / 5 / 20 10 S hel b y

M u s k e g o n I L 2 R U N/R P o s t

- bro a d ca s t 10 0% o f 10 8 ac r es

M I 2 UN S pr ay 1 .2 a c r es

I023 4 4 4

- 0 26 7 / 6 / 20 11 R ed W i l l o w NE 2 UN N/R Br o ad ca s t 10 0% o f 2 8 3 a c r es

I023 4 4 4

- 0 22 7 / 28 / 2 0 1 1 N u ckolls NE 2 UN N/R Br o ad ca s t 54 % of 1 8 5 a c r es

## Appendix C : SIP Inputs and Outputs

Table 1. Inputs

Parameter Value

Chemical name Mesotrione
Solubility (in water at 25 o C; mg/L) 1600

Mammalian LD 50 (mg/kg

- bw) 5000

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

Mammalian NOAEL (mg/kg

- bw) 10
Mammalian test species other Body weight (g) of "other" mammalian species 35

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) 120 Bobwhite quail NOAEC (mg/kg

- diet) 3000 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 speciesEnter body weight of 'other' mammalian species for NOAEL.

Table 2. Mammalian Results

Parameter Acute Chronic Upper bound exposure (mg/kg

- bw) 275.2000 275.2000 Adjusted toxicity value (mg/kg

- bw) 3845.8028 4.3253 Ratio of exposure to toxicity 0.0716 63.6255

Conclusion* Drinking water exposure alone is NOT a potential

concern for mammals Exposure through drinking water alone is a potential concern for

mammals

Table 3. Avian Results

Parameter Acute Chronic Upper bound exposure (mg/kg

- bw) 1296.0000 1296.0000 Adjusted toxicity value (mg/kg

- bw) 1440.8590 5.9535 Ratio of exposure to acute toxicity 0.8995 217.6868

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.