Date: Chemical: PC Code: DPBarcode: UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON; D.C.**ZO~l;O**

ornCE OF PREVEm'ION, PF$TlCIDl?S AND TOlClC SlmSTANCES January 22. 2010 Aminocyclopyrachlor 288008,288009,288010 DP 358167


### MEMORANDUM

SUBJECT: Transmittal Memo regarding the "Ecological Risk Assessment for the Section 3 New Chemical Registration ofAminocyclopyrachlor on Non-crop Areas .md Turf'



### FROM:

TO: Anita Ullagaddi, M.S., Environmental

# P~otectiO**~~egiali** t Christopher M. Koper, M.S., Chemist "i(: '2.:1

.. 3J\1,; J,.(1l0 

# Y o--! ....-Anita Pease, M.S., Acting Branch Chief 

### 'frrh /' Environmental Risk Branch I

. Environmental Fate and Effects Division (7507P) Jim Tompkins. Risk Manager Mindy Dodish, Risk Manager Reviewer Registration Division (7505P)

EJ. du Pont de Nemours and Company (DuPont) submitted a petition to the Environmental Protection Agency (EPA) to register the new chemical aminocyclopyracW r. DuPont proposed two technical active ingredients (aminocyclopyrachlor acid and aminocyclopyrachlor methyl ester). The acid can also be fonnulated into aminocyclopyrachlor potassium salt. The proposed uses are on non-crop areas and turf for pre- and post-emergent control ofbroadleaf weeds and grasses. This memorandum summarizes the attached Environmental Fate and Effects Division (EFED)'s ecological risk assessment for aminocyclopyracWor for the proposed uses. Five technical and manufacturing concentrate labels and 29 labels for formulations were submitted under DP 368239 and 358167. EFED's assessment is based on all 29 end-use product labels. However, it was brought to EFED's attention on January 21, 2010 that some labels may be withdrawn. The exact number of labels and their identity that may be withdrawn were unknown at the time this assessment was completed. Because the proposed action to withdraw labels for consideration for registration bas not been received by EFED, thIS assessment includesall 29 labe1s submitted under DP 368239 and 358167. Ifthe registrant proposes to remove specified labels from considerationJQr**regi~tration,** then 

### EFED will submjt an**addend~m** tQ**t1l~** attached ecological risk assessment if the remaining labels do not reflect the assessed uses. Table A shows examples of the proposed application rates for the uses that have been modeled for this ecological risk assessment. See Table 3.1 for a complete table containing all maximwn proposed application rates for the 29 submitted product labels. 

### Table A. Maximum Application Rates from tbe Proposed Aminocvclo .vrachlor Labels Application Single Application Rate Max. # of Maximum Compound Use Method' (Interval between Applications 1 AppUcatiOD Annlicationsl Rate/Year Non-Crop Aerial or 0.284 Ib a.eJA Ground

- I 0.284 Ib a.e .fA Aminocyclopyrachlor WDG (NA) Acid 0.108tb a.eJA Turf Ground - G (30 days) 3 0.324 Ib a.e JA NA = Not Applicable l WDG = waler dispersible granule; SC 

## =soluble concentrate; G 

## = granule. Iff not specified on label, number of applications may have been calculated based on maximum single application rate and maximum annual application rate.

Risks to Non-target Organisms



# ... A screening-level risk assessment based on proposed uses suggests that aminocyclopyrachlor presents potential risks to both non-listed and listed terrestrial plants and 10 organisms that depend on terrestrial plants for habitat and forage. Due to lack of acceptable avian reproduction and freshwater invertebrate life cycle toxicity data, chronic risks to non-listed and listed birds and freshwater and estuarine/marine invertebrates are assumed. Outstanding Data Requirements No additional environmental fate data are recommended for request at this time. Several additional environmental effects studies were identified as data gaps (see Section 2.6.2). The following two studies are high priority studies because they have the potential to add value to the assessment by characterizing potential risks by eliminating uncertainties for both nonlisted and listed species that cannot be accounted for using alternate methods or weights or evidence. Acid

• Avian Reproduction Toxicity Test (850.2300): Data are required for both an upland game and waterfowl species for the proposed use patterns. The submitted studies were classified as invalid due to improper husbandry practices (cage sizes that were much smaller than those recommended in the guideline) that may have caused incidental mortalities in quails and reduced

2egg production in mallards (see Section 4.2.1). Because ofthe lack of avian reproduction data, potential chronic risks to birds cannot be precluded for non-listed and listed species.

• Freshwater Invertebrate Life Cycle Toxicity Test (850.1300): Non dose-response mortalities were observed in the three lowest treatment levels (40%, 30%, and 40%, respectively) for the submitted freshwater daphnid study. Therefore, a NOAEC could not be established. Due to the high mortality observed in the first three treatment levels, the resulting toxicity values are not a reliable estimate of the chronic toxicity to water fleas (see Section 4.1.2 for details). Recommended Labeling Language Following review of physicochemical properties and incident data of similar registered chemicals, EFED recommends that the following language be placed on all aminocyclopyrachlor labels: Surface WalerAdvisory This product may impact surface water quality due to spray drift and runo)jofrain water. 771is is especially trueforpoorly draining soils and soils with shallow ground water. This product is classified as having high potential for reaching surface water via runoff for several months after application. A level, well-maintained vegetative buffer strip**betwee/~** areas to which this product is applied and surface water fealures such as ponds, streams, and springs will reduce lhe pOlenlialloading of aminocyclopyrachlor from runoffwater and sediment. RIUlOff ofthis product will be reduced by avoiding applications when rainfall isforecast to occur within 48 hours. See manual at thefollowing Internet address: http://www.wsi.nrcs.usda.gov/products/\¥2Q/pesvcore4.html Ground Waler Advisory This chemical has properties and characteristics associated with chemicals detected in ground water. This chemical may leach into ground water 

### Ifused in areas where soils are permeable, particularly where the water table is shallow. Residues in Plants orManure Do not use plant residues including grass or hayfr.om trealed areas or manurefrom animals beingfed treated forage or hayfor composting or m"lching of desirable, susceptible broadleaf plants. Do not use manurefrom animals grazing treated areas on land IIsedfor growing broadleaf crops, ornamentals, orchards or other susceptible, desirable plants. ManllTe may contain enough aminocyclopyrachlor to cause injury to susceptible plants. [n addition, EFED has concerns with spray drift management language on the proposed labels. The recommended droplet sizes (>150 to 200 microns) on the proposed labels are consistent with fine droplets according to the American Society ofAgricultural and Biological Engineers (AS ABE). The label characterizes these droplets as "large". Assuming large droplets are similar to course droplets as defined by ASABE, the volume median diameter (YMD) should be >326 microns. Recommended droplet sizes on the proposed labels need to be consistent with ASABE classifications of droplet size.

3

### Ecological Risk Assessment for the Section 3 New Chemical Registration ofAminocyclopyrachlor on Non-crop Areas and Turf



# o OH

CAS: 858956·08·8 (acid), 858954·83·3 (esler), 858956·35·1 (sail) U.S. EPA PC Code: 288008 (acid), 288009 (esler), 288010 (sail)



### Team Members Anita UUagaddi, M.S., Environmental Protection Specialist Christopher M. Koper, M.S., Chemist Peer Reviewers Christine Hartless. Ph.D., Wildlife Biologist James Lin, Ph.D. Environmental Engineer Acting ERBI Branch Chief Anita Pease. M.S. Dale of Approval January 22, 2010

### TABLE OF CONTENTS



## .................................................................................................................................... 1 Executive Summary 4

...................................................................................................................... 1.1 Nature of Chemical Stressor 4

................................................................................................... 1.2 Potential Risks to Non-target Organisms 5

.................................................................................................. 1.3 Conclusions: Exposure Characterization 6 1.4 Conclusions: Effects Characterization
....................................................................................................... 7

................................................................................................................................................... 1.5 Data Gaps 8



## ........................................................................................................................................ 2 Problem Formulation 8

...................................................................................................................... 2.1 Nature of Regulatory Action 8 2.2 Stressor Source and Distribution
................................................................................................................ 9 2.2.1 Nature of the Chemical Stressor
................................................................................................................. 9

........................................................................................................................................ Mode of Action 11

.................................................................................. Environmental Fate and Effects Bridging Strategy 11

................................................................................................................... Overviewof Pesticide Usage 13

.................................................................................................................................................. Receptors 13

................................................................................................................ Aquatic and Terrestrial Effects 13

................................................................................................................ Ecosystems Potentially at Risk 13

.................................................................................................................................... Ecological Effects 14

.................................................................................................................................... Conceptual Model 14 Risk Hypotheses
....................................................................................................................................... 14 Conceptual Diagram
................................................................................................................................. 15 Analysis Plan
............................................................................................................................................ 16

............................................................................................................. Measures of Effect and Exposure 16 Data Gaps
................................................................................................................................................. 17 3 Exposure Analysis

## ............................................................................................................................................ 20

................................................................................................................................ 3.1 Use Characterization 20

............................................................................................................................... 3.2 Exposure Assessment 24

................................................................................ 3.2.1 Environmental Fate and Transport Characterization 24

........................................................................... 3.2.2 Aquatic Exposure Estimates for Aminocyclopyrachlor 32

................................................................................................................ 3.2.3 Terrestrial Wildlife Exposures 35

......................................................................................... 3.2.4 Terrestrial and Semi-Aquatic Plant Exposures 36 4 Ecological Effects Analysis

## .............................................................................................................................. 37 4.1 Aquatic Effects Summary
........................................................................................................................ 37 4.1.1 Toxicity Effects on Fish
.......................................................................................................................... 37

............................................................................................................. 4.1.2 Toxicity Effects on Invertebrates 38.............. Toxicity Effects on Plants
........................................................................................................ 

### ; 40 Terrestrial Effects Summary
..................................................................................................... I .............. 41

.............. .......................................................................................................... Toxicity Effects on Birds : 41 Toxicity Effects on Mammals


### .................................................................................................................. 43 I



### .............. ............................................................................................. Toxicity Effects on Invertebrates 44 I

.......... ........................................................................... ........................... Toxicity Effects onPlants 1.. 1. $45

.................................................................................................. Comparisonof Ester and Acid Toxicity 

# I 46 Review of IncidentData
........................................................................................................................... 47 

# I Review of ECOTOX Data
...................................................................................................... 

### 1

............47 I

......................................................................................................... 5.1.3

. Terrestrial and Semi-aquatic Plants 

# 1 50 

## .................................................................................................................................... 5 Risk Characterization 

## 1 47

...................................................................................................................................... 5.2 Risk Description 5 1 

# I

............................................................................ 5.2.1 Risks of Aminocyclopyrachlorto Aquatic Organisms 51

........................................................... ............. 5.2.2 Risks of Arninocyclopyrachlor to Terrestrial Organisms 52 i i 5.2.3 Potential Risks Due to Exposure to the Degradates
............................................................................. 54 I

........................................................................................ 5.3 Threatened and Endangered Species Concern 57 I 5.1 Risk Estimation: Integrationof Exposure and Effects Data
.....................................................................

.................................................................................. 5.1.1 Non-target Aquatic Fish, Invertebrates,and Plants 5.1.2 Non-target TerrestrialAnimals
................................................................................................................

5.3.1 Action Area
............................................................................................................................................ 57 5.3.2 Taxonomic Groups Potentially at Risk: Direct Effects
.......................................................................... 

# 1 58 i 5.3.3 Use of Probit Slope Response Relationshipto Provide Informationonthe Endangered specie+ Levels of

.......... ................................................................................................................................... Concern 

### .........I.. .59 I 47 48 49

i 5.3.4 Indirect Effects Analysis
.......................................................................................................................... 59 I



## .............................................................................................................................................. 7 Literature Cited 

# 1 64 

# ................................................... 6 Description of Assumptions, Uncertainties, Strengths, and Limitations 

## 1 59

................................................. 

### ........... 6.1 Assumptions and LimitationsRelated to Exposurefor all Taxa 59

............................................ 6.2 Assumptions and Limitations Related to Exposurefor Terrestrial Species 60 

# i

................................................ 6.3 Assumptions and LimitationsRelated to Exposure for Aquatic Species

.................................................................. 6.4 Assumptions and LimitationsRelated to Effects Assessment 62 62

### 1 Executive Summary 1. Nature of Chemical Stressor E.I. du Pont de Nemours and Company (DuPont) is seeking registration for aminocyclopyrachlor, an herbicide in the pyrimidine carboxylic acids class within the family of synthetic auxins. Aminocyclopyrachloris proposed for registration in three different forms. Aminocyclopyrachlor acid (DPX-MAT28,referred to as the acid) and aminocyclopyrachlor methyl ester (DPX-KJM44,referred to as the ester) are technical active ingredients, and these, along with aminocyclopyrachlor potassium salt (referred to as the salt), are formulated into 29 different end-use products. These 29 product labels, which were submittedunder DP368239 and DP358167, are included in this ecological risk assessment. Aminocyclopyrachloris a systemic herbicide; it is biologically active in soil and rapidly absorbed by roots and leaves. It is then translocated through xylem and phloem until it reaches the meristematicplant regions where it mimics the plant hormone auxin. Upregulation of a set of proteins responsible for gene repression and the loss of tight control of the expression of a set of genes that maintain hormonal balance result in undifferentiated cell division and elongation; however, the changes in regulation of gene expression have not been thoroughly described. Effects to target weeds include epinasty (downwardbending of leaves), severe necrosis, stem thickening, growth stunting,leaf crinkling, calloused stems and leaf veins, leaf-cupping, and enlarged roots. These symptoms may begin a few hours to a few days after application, and plant death may take weeks to several months. Aminocyclopyrachlor has been proposed for pre-emergent and post-emergent control of broadleaf weeds, woody species, vines, and grasses in uncultivated non-agricultural areas (airports, highway, railroad and utility rights-of-way, sewage disposal areas), uncultivated agricultural areas -non-crop producing (farmyards, fuel storage areas, fence rows, non-irrigation ditchbanks, barrier strips), industrial sites 

### -outdoor (lumberyards, pipeline and tank farms), natural areas (wildlife management areas, wildlife openings, wildlife habitats, recreation areas, campgrounds, trailheads, and trails), and native grasses and turf grasses. 

### Table 1.1 contains maximum proposed application rates, which were assessed in this document; see 

### Table 

### 3.1 for a complete rate table for all 29 proposed products.

0.284 Ib a.e ./A Arninocyclopyrachlor WDG Acid

NA =Not Applicable 'WDG = water dispersible granule; SC = soluble concentrate; G = granule. 2If not specified on label, number of applicationsmay have been calculatedbased on maximum single application rate and maximum annual application rate. Turf Ground - G 0.108 Ib a.e./A (30 days) 3 0.324Ib a.e ./ADuPont proposed a bridging strategy to relate the environmentalfate and toxicity data @m one form to the other two forms of the chemical due to the ester hydrolyzing rapidly to the #cid and the salt dissociating rapidly to the acid. Therefore,most studies were submitted for the hcid only. In a few cases, studies were conducted with the ester to confirm equivalent toxicity or because it was a more appropriate product. No studies were submittedthat evaluated the toxicity potassium salt. After review of the submitted data, EFED has determined that bridging strategy is not sufficient for evaluating toxicity to non-target a different strategy consideringthe nature of the chemical (see 

### 1.2 

### Potential Risks to Non-target Organisms I I 

### A screening-level risk assessmentbased on proposed uses suggests that aminocyclopyr chlor presents potential risks to both non-listed and listed terrestrialplants and to organisms at depend on terrestrial plants for habitat and forage. Due to lack of acceptableavian repr duction and freshwater invertebrate life cycle toxicity data, chronicrisks to non-listed and liste birds and freshwater and estuarinelmarine invertebrates are assumed. 

# I

I Severalmajor degradateswere identified to be of possible concern. Due to the lack of s bmitted toxicity data for the degradates,potential risks were described (see 

### Section 5.2.3) using methods such as structure activity relationships (SARs),total toxic residue (TTR) approach, and

# 1
comparisons of environmentally relevant concentrationsto effects thresholds. From this EFED was ableto reduce uncertainties regarding potential risks due to exposures to the degradates in the absence of toxicity data. 

### Listed Species Based on available screening level information, for the proposed uses of aminocyclopyr chlor, there is a potential for direct effectsto listed terrestrial plants. Due to lack of acceptable data for the acid, direct effects are assumed for birds (chronic) and freshwaterinvertebrates (chr nic). 

# I Consequently, direct effects must be assumed for estuarinelmarineinvertebrates (chroni ). Submittal of a chronic avian reproduction study and chronic freshwater invertebrate stu y would reduce the uncertainties associatedwith the presumed risk to these taxa. Based on risks o terrestrialplants and presumed chronic risk to freshwaterinvertebrates and birds, there i a potential concern for indirect effects to listed species via habitat perturbation andlorred ction in

effects determinationsis presented in 

### Table 1.1.Because the proposed uses of 

# I

the availabilityof forage or prey. 

### In conducting a screen for indirect effects, direct effec LOCs for each taxonomic group are used to make inferences concerning the potential for indir ct effects upon listed species that rely upon non-endangered organisms in these taxonomic groups as resources critical'totheir life cycle. A summary of the risk conclusions and direct and indirect 

# 1

aminocyclopyrachlor cannot be geographically limited, all federally listed species may be either directly or indirectly affected. I

Terrestrial and semi-aquatic Yes Yes plants -monocots

### Incidents Although no incidentshave been reported for aminocyclopyrachlor because it is a new chemical, several incidents have been reported for a similar class of chemicals, the pyridine carboxylic acids. Incidents involving herbicides such as aminopyralid, picloram, and clopyralid were reported when treated plant residues or manure from animals fed treated residues were used in compost. The compost was then spread on areas where desirable crops or lawns were grown, and crop damage, which may have been caused by a pyridine carboxylic acid herbicide, was observed (see 

### Section 4.4 for more details). Some states as well as the United Kingdom were prompted to take regulatory action because of these incidents. Because aminocyclopyrachlor also shares the persistent and systemic nature in soil and the high seedling emergence toxicity with these similar chemicals, similar incidents could occur following the application of aminocyclopyrachlor. 

### 1.3 

### Conclusions: Exposure Characterization Based on the registrant-submitted studies, the following conclusions were drawn regarding the environmental fate of aminocyclopyrachlor: Aminocyclopyrachloris non-volatile (3.7 x 

### rnm Hg and KH= 3.47 x 10-l2atmm3/mol)and highly soluble (2810mgLat 20°C) in water. Based on the batch equilibrium data, aminocyclopyrachlor displays an affinityto organic carbon. Adsorption (KO,= 2 to 

### 26 rnL/g,) is characterized as being highly mobile to mobile in the test soils.Therefore, dissipationof aminocyclopyrachlor in the environment is expected t$ occur predominantly from runoff and leaching. I The octanol/water partition coefficient (log 

### K, of -2.48 at 20' at pH 7) for 

## ; aminocyclopyrachlor suggests that it has a low tendency for bioaccumulation. 

# ~ Considering biodegradation, aminocyclopyrachlor is persistent in aerobic aquat c and and anaerobic terrestrial environments. 

# i aerobic terrestrial environments. 

### In addition, it is relatively stablein anaerobic ~quatic 

### I Considering abiotic degradation, aqueous photolysis is the major route of degra aminocyclopyrachlor is expected to degrade with a half-life of 1.2days in and well-litnatural (pH 6.2) water bodies and 7.8 days in pH 4 buffer it is slowly photolyzed on soil (tlIz = 129days). hydrolysis at pH 4,7, and 9. Dissipation occurred with half-lives ranging from 22 to 126days in terrestrial fi dissipation studies conducted in the continental United States and Canada. 

# i The major transformation products of aminocyclopyrachlorof concern at this ti IN-LXT69, IN-V0977 and IN-YY905.However,these degradates are not occur at environmentally relevant concentrations relativeto effects thresholds. 

### 1 Conclusions regarding the environmental exposure concentrations for presented below: AquaticEECs produced by GENEEC ranged from 16.64ppb (60-day)to (peak) for aerial spray applications to non-crop areas for one application lb a.e./acre. EECs ranged from 16.26ppb (60-day)to 16.47ppb (peak) applications to non-crop areas for one application at a rate of 0.284 lb ground granular applications at a rate of three applications at 0.108 lb interval), EECs ranged from 16.60ppb (60-day) to 16.82ppb (peak). Considering the highest proposed applicationrate (one application at 0.284 lb a. ./acre), dietary-based exposure concentrations for terrestrialwildlife ranged from 4.26 t 68.16 ppm. Avian and mammalian oral dose concentrations ranged from 0.28 to 77.63 

### glkgbw and 0.14 to 64.99 mglkg-bw, respectively. Terrestrial and semi-aquatic plant ECs ranged from 0 to 0.1562ppm. 

# \

I 

### 1.4 Conclusions: Effects Characterization I I Based on the registrant-submitted studies, the following conclusions were drawn regardi g the environmental effects of aminocyclopyrachlor: 

# h

Studies that evaluated the effects of the acid (DPX-MAT28)and the ester were submitted for aquaticflora and fauna. Toxicityclassifications forranged from practically non-toxic to slightly toxic. The acute freshwater fish and daphnid studies showed that the ester may be more toxic than the acid. No effects were observed in the chronic freshwater fish study, and a toxicity value could not be obtained from the chronic freshwater invertebrate study (see 

### Section 4.1.2). For the most part, aminocyclopyrachlor was practically non-toxic to birds, mammals, and honey bees. As expected since aminocyclopyrachlor is an herbicide, toxicitybased on seedling emergence and vegetativevigor endpointswere observed in the plant studies. 1.5 

### Data Gaps No environmental fate data gaps were identified. Several environmental effects data gaps were identified (see 

### Section 2.6.2). The following two studies are high priority studies because they have the potential to add value to the assessmentby characterizingpotential risks by eliminating uncertainties for both non-listed and listed species that cannot be accounted for using alternatemethods or weights or evidence. 

### Acid Avian Reproduction Toxicity Test (850.2300): Data are required for both an upland game and waterfowl species for the proposed use patterns. The submitted studies were classified as invalid due to improper husbandry practices (cage sizes that were much smaller than those recommended in the guideline) that may have caused incidental mortalities in quails and reduced egg production in mallards (see 

### Section 4.2.1). Because of the lack of avian reproduction data, potential chronicrisks to birds cannot be precluded for non-listed and listed species. Freshwater Invertebrate Life Cycle ToxicityTest (850.1300):Non dose-response mortalities were observed in the three lowest treatment levels (40%, 30%, and 40%, respectively) for the submitted freshwaterdaphnid study. Therefore, a NOAEC could not be established. Due to the high mortality observed in the first three treatment levels, the resulting toxicity values are not a reliable estimate of the chronic toxicity to water fleas (see 

### Section 4.1.2 for details). 

### 2 

### Problem Formulation 2.1 

### Nature of Regulatory Action The purpose of this assessment is to evaluate the environmental fate and ecological risks for the registration of the new chemical aminocyclopyrachlor. Aminocyclopyrachlor can be used pre- or post-emergently to controlbroadleaf weeds, woody species, vines, and certain grasses in nonagricultural areas, agriculturalnon-crop areas, industrial sites,natural areas, and in a residential and commercial setting for the protection of turf. As a new chemical, 

### U.S. EPA is required under the Federal Insecticide Fungicide and RodenticideAct (FIFRA) to ensurethat aminocyclopyrachlor does not have the potential to causeunreasonable adverse effects to the environment. Potential effects to listed species (i.e.,species on the Federal list of endangeredand threatened wildlife and plants) are also considered under the Endangered SpeciesAct in order to ensure that the registration of aminocyclopyrachloris not l~kely tojeopardize continued existence of such listed species or adversely modify their habitat. To these e 

# $e

ds, this assessment follows U.S. EPA guidance on conducting ecological risk assessments (U.9EPA, 

### 1998) and the Office of Pesticide Program's policies for assessing risk to non-target and listed organisms (U.S. EPA, 

### 2004). I I Among the end products of the U.S. EPA pesticide registrationprocess is a whether a product is eligible for registration and, if so, an enforceable product may be used. A label represents the legal documentwhich given pesticide may be used. End-use labels describe the of application, where the product may be applied, and be conducted. Thus, the use, or potential use, "the action" being assessed. 

### 2.2 StressorSource and Distribution I 

### 2.2.1 Nature of the Chemical Stressor I Aminocyclopyrachloris a synthetic auxin and is the first member of a new class of chemistry called the pyrimidine carboxylic acids. This new class is similar to the pyridine carboxy ic acid class, which includes herbicides such as aminopyralid, clopyralid, and picloram. The ch mical's major route of degradation is aqueous photolysis. Aminocyclopyrachloris stableto hyd olysis at pH 4 and 7.Arninocyclopyrachlor is expected to be highly mobile to mobile. It has low

# 1
olatility and is highly soluble in water. Therefore, dissipation of aminocyclopyrachlor from the 

# ~ application site is expected to occur predominantlyvia aqueous photolysis, runoff, and Chemical characteristicsof aminocyclopyrachlorand field dissipation studies suggest residues may leach into ground water. Additionally, off-sitemovement of is expectedthrough spray drift from aerial and ground spray.A summary environmentalfate data on arninocyclopyrachlor is provided in 

### Table 2.1; more detaile descriptionsof the submitted environmental fate data can be found in 

### Section3.2.1.

Common Name

Pesticide Class:

EPA PC Code:

IUPAC Name: Aminocyclopyrachlor synthetic auxin herbicide (pyrimidine carboxylic acid)

288008 (acid), 288009 (ester), 288010 (salt) 6-Amino-5-chloro-2-cyclopropyIpyrimidine-4- carboxylic acid --

I -- I 

# ~ I

-- ! I


## ~
-- 

### i ICAS Name(s):

CAS No:

Formula:

Structure:

Molecular Mass (glmol)
Vapor pressure (torr) at 25' C
Henry's Law Constant at 20' C (atm m3/mol)

Solubility in Water (mg/L) at 20 OC

Octanol- Water Partition Coefficient (Log KO, ) at 20 OC

Dissociation ConstantpKa at 20°C 6-Amino-5-chloro-2-cyclopropyl-4- pyrimidinecarboxylic acid 6-Amino-5-chloro-2-cyclopropyl-pyrimidine-4- carboxylic acid

858956-08-8

CsH8C1N302

28 10in Milli-Q water 3130 atpH4 4200 at pH 7 3870 at pH 92.2.2 

### Mode of Action I According to the registrant, aminocyclopyrachlor is a systemicherbicide; it is biologicz+lly active in soil and rapidly absorbed by roots and leaves. It is then translocated through xylem and phloem until it reaches the meristematic plant regions where it mimics the plant homo e auxin. Upregulation of a set of proteins responsiblefor generepression and the loss of tight co trol of the expression of a set of genes that maintain hormonal balance result 

### in undifferentiate cell division and elongation; however, the changes in regulation of gene expression have no 

# 1

been thoroughly described. Effects to target weeds include epinasty, severenecrosis, stem th ckening, growth stunting, leaf crinkling,calloused stems and leaf veins, leaf-cupping, and enlarg roots. These symptoms may begin a few hours to a few days after application and death may t e weeks to several months. 2.2.3 

### Environmental Fate and Effects Bridging Strategy 

# i

There are three proposed forms of aminocyclopyrachlor: 

### (1)an acid, (2) a methyl ester, and (3) a potassium salt. The registrant did not submit a full suite of required studies for each fo of the chemical. Instead, the registrant submitted mostly full suites of environmental fate and

# i
ffects studies for the acid form of aminocyclopyrachlor, limited data were submitted for the m thy1 

# i; ester, and only a dissociation study was submitted for thepotassium salt. All fate and I toxicological values were converted to the acid equivalent (a.e.)based on the ratio of molecular weights. This was done for ease of comparing fate parameters and toxicity values acros the various forms of aminocyclopyrachlor. It was determined,based on the submitted study that the potassium salt dissociates to the acid rapidly prior to application (when mixed with wat r as the two salt formulation labels state) and that the methyl ester hydrolyzes to the acid in the summarized in 

### Tables 3.2,3.3, and 3.4. 

# I

environment 

### (Figure 1).Availableenvironmental fate data submittedby the registrant


### Figure 

### 1. Schematic of Bridging Strategy of Aminocyclopyrachlor Methyl Ester an Aminocyclopyrachlor Potassium Salt to Aminocyclopyrachlor Acid 

## I ACP Potassium Salt

# + dissociation in water 

### 3 ACP Acid 

## +Potassium Cation 

### (K') 

# 1 I ACP Methyl Ester

# +' microbial-mediated hydrolysis 

# +ACP Acid 

## +Alcohol (methanol alkaline-catalyzed hydrolysis

To assessthe dissociation of the potassium dissociation constant 

### (MRID 478909-01). was previously determined to be 4.65. The dissociation constant of the 4.63 when conducting measurements within 2 to 7 minutes after the to the test system. This study supports the rapid conversion of the base of the acid and the potassium cation.This similarity in behavior of aminocyclopyrachlor acid andTherefore, environmental fate and toxicity data submitted on the acid is also relevant for the potassium salt for the currently proposed uses; if different formulations of the salt are proposed 

### in the future where the salt would be released to the environment rather than dissociating to the acid prior to application (for instance, a granular salt formulation), a full suite of salt toxicity data may be necessary. The submitted laboratory and terrestrial field dissipation data indicate the arninocyclopyrachlor methyl ester is hydrolyzed in alkaline aquatic environments, moist soils, and soillwater slurries. Degradation under environmentally relevantpH conditions is primarily microbe-mediated. Therefore, use of the methyl ester end-use products of aminocyclopyrachlor may result in shortterm exposures to the methyl ester form of arninocyclopyrachlor. However, the methyl ester is expected to degrade to the acid form of aminocyclopyrachlor rapidly under most environmental conditions. The de-esterification of arninocyclopyrachlor methyl ester is more difficult to generalize because it is dependent onheterogeneous hydrolysis (microbe-mediated)and homogeneous hydrolysis (abiotic alkaline catalyzed (Schwarzenbach

### et al., 1993).The de-esterificationof arninocyclopyrachlormethyl ester leads to the formation of the arninocyclopyrachlor acid and the associated alcohol, methanol. Unlike the physical dissociation mechanism of the arninocyclopyrachlor potassium salt, the de-esterificationof aminocyclopyrachlormethyl ester is dependent on abiotic and microbe-mediated processes. Any environmental variable influencing microbe populations or activity could theoretically influence the persistence of aminocyclopyrachlor methyl ester. Soil properties including clay mineralogy, organic carbon content, temperature, and moisture content are known to influence hydrolysis rates (Wolfe et al., 1989and Wolfe, 1990). Registrant-sponsored research indicates that arninocyclopyrachlormethyl ester degrades to form the acid. In the hydrolysis study (MRID478357-Ol),the calculated half-lives at 20°C for pH 4, 7 and 9 were 27, 52 and 0.3 days, respectively. This data suggests alkaline-catalyzed abiotic hydrolysis. Since the hydrolysis study is conducted in a sterile (abiotic) environment, an aerobic soil metabolism 

### (MRID 475602-14) and a batch equilibrium 

### (MRID 475602-18) study were investigated. 

### In the aerobic soil metabolism study, the half-life could not be accurately calculated because of the rapid transformationto the arninocyclopyrachlor acid in acidic soil (pH = 

### 5.4). In the batch equilibrium studies,rapid degradation of the test substancewas also observed in acidic and alkaline soils. The weight of evidence from the aerobic soil metabolism and batch equilibrium (biotic) studies suggest a microbe-mediated hydrolyticprocess at lower pHs. Only two aquatic studies were submitted for the ester (see 

### Section4). The submitted data did not confirm equivalent toxicity; the freshwater fish toxicity value was about an order of magnitude more toxic for the ester than the acid and the freshwater invertebrate toxicity value was about twice as toxic for the ester than the acid. Although acute terrestrial toxicity (based on submitted toxicity data) and chronic terrestrial and chronic aquatic toxicity (based on submitted fate data) for the ester is suspectedto be equivalentto the acid, other aquatictaxa may be exposed to the ester on an acute basis.

### 2.3 Overview ofPesticide Usage , Aminocyclopyrachlor has been proposed for gre-emergent and post-emergent control of broadleaf weeds, woody species, vines, and g~rasses in uncultivated non-agriculturalare'hs (airports, highway, railroad and utility rights-of-way, sewage disposal areas), agricultural areas -non-crop producing (farmyards, fuel storage ditchbanks, barrier strips), industrial sites -outdoor (lumberyards,pipeline natural areas (wildlife management areas, wildlife openings, wildlife campgrounds, trailheads, and trails), and native grasses and turf are found throughout the United States and cannotbe limited to aminocyclopyrachloris a new chemical, use data does not yet exist. 

### 2.4 Receptors 2.4.1 Aquatic and TerrestrialEffects 

# ! The receptor is the biological entity that is exposed to the stressor (U.S. EPA, 

### 1998).C with the process described in the Overview Document (U.S. EPA, 2004), this risk uses a surrogate species approach in its evaluationof aminocyclopyrachlor. generated from surrogate test species,which are intended to be taxonomic groups, are used to extrapolateto potential effects on a variety included under these taxonomic groupings. Acute and chronic toxicity data from studies submittedby pesticide registrants along available open literature are used to evaluatethe potential direct effects of to the aquatic and terrestrialreceptors identified in this section. This technical grade active ingredient, degradates, and when available, "Six-Pack" studies).The open literature studies are identified availableECOTOX database 

### (http://cfpub.epa.~ov/ecotox/), engine for locating chemical toxicity data for aquatic life, evaluationof both sources of data can also provide aminocyclopyrachlor on biotic communities from loss of species that are sensitiveto th chemical and from changes in structure and functional characteristicsof the affected communities. 

# ~ 2.4.2 Ecosystems Potentially at Risk I
I

Aquatic ecosystems potentially at risk includewater bodies adjacent to, or down stream treated field and might include impounded bodlies such as ponds, lakes and reservoirs, o The ecosystems at risk are often extensive 

### in scope; as a result, it may not be possible to1 specific ecosystems during the development of a baseline risk assessment. However, in terms, terrestrial ecosystems potentially at risk could include the treated field and areas immediately adjacent to the treated field that may receive drift or runoff. Areas adjacent treated field could include cultivated fields, fencerows and hedgerows,meadows, fallow grasslands, woodlands, riparian habitats and other uncultivated areas. identify general
to the fields orwaterways such as streams or rivers. For uses in coastal areas, aquatic habitat also includes marine ecosystems, including estuaries. 

### 2.4.3 Ecological Effects Each assessment endpointrequires one or more "measures of ecologicaleffect," which are defined as changes in the attributes of an assessment endpoint itself or changes in a surrogate entity or attribute in response to exposureto a pesticide. Ecological measurement endpoints for this risk assessment would be based on toxicity informationfor aminocyclopyrachlor in the publicly availableECOTOX database (if available) and a suite of registrant-submitted toxicity studies performed on a limited number of organisms in the followingbroad groupings: 1. Birds (mallard duck or bobwhite quail and a passerine species), also used as a surrogate for terrestrial-phaseamphibians and reptiles 2. Mammals (laboratory rat) 3. Freshwater fish (rainbow trout and bluegill sunfish), also used as a surrogate for aquaticphase amphibians 

### 4. Freshwater invertebrates (daphnid) 

### 5. Estuarinelmarine fish (sheepshead minnow) 

### 6. Estuarinelmarine invertebrates (Eastern oyster, mysid shrimp) 

### 7. Terrestrialplants (monocots and dicots) 8. Aquaticplants (vascular and non-vascular plants) 9. Terrestrialinvertebrates (honeybee) Within each of these very broad taxonomic groups, an acute and chronic endpoint is selected from the available test data, as the data allow. 

### 2.5 Conceptual Model A conceptual model provides a written descriptionand visual representationof the predicted relationships between aminocyclopyrachlor,potentialroutes of exposure, and the predicted effects for the assessment endpoint.A conceptual model consists of two major components: risk hypotheses and a conceptual diagram 

### (U.S.EPA, 1998). 

### 2.5.1 Risk Hypotheses Terrestrial and aquaticorganisms are subject to adverse direct effects such as reduced survival,growth, and fecundity or indirect effects such as habitat, food web dynamics, perturbing forage or prey availability,and altering the extent and nature of nesting when exposed to 

### aminocyclopyrachlor/degradateresidues as a result of labeled use of the pesticide. Non-target terrestrial, semi-aquatic,and aquaticplants are subject to adverseeffects such as reductions in vegetativevigor and seedling emergence (terrestrial)or biomass and growth rate (aquatic) when exposed to aminocyclopyrachlor/degradate residues as a result of labeled use of the pesticide

### 2.5.2 

### Conceptual

### Diagram I 

### In order for a biologically significant contaminantmoves 

### in the environmentfrom a sourceto an ecological exposurepathway to be complete,it must have a source, a release transport medium, a point of exposure for ecological receptors, In addition, the potential mechanisms of transformation (i.e., environment, 

### in which media, and how much) must be metabolitesldegradates exposurepathways, pathways for constituents, and the inhalation, and dermal absorption). Figure2. Conceptual model depicting ecological risk based on proposed aminocyclopyrachlor appl cations. Dotted boxes indicated pathways not considered in the risk assessment. 

# i

Based on the labels submitted by the registrant, the source and mechanisms of release fo aminocyclopyrachlor are aerial andlor ground application in the form of soluble concent

# 1 ates and water dispersiblegranules (for non-crop uses and someprofessional turf uses) or 

## ground^ application as a granule (with a fertilizer for all residential and most professional turf us4s). The I Stressor 

# I Aminocyclopyrachlor Applied Aerially and by Ground I 

# + + 4 4 I
I------------ Source1 Volatilization/ 

## : Ground SprayDrift Runoff1 Leaching I I Transport Wind 

## : Deposition Erosion (Infiltration/ 1 pathway I Suspension Percolation) I

### ---- , 

### - , 

### -- , 

### -- 

# + Source/ Exposure Media 4- Ground water Terrestrial Food Residues (foliage, fruit, insects)/ Soil 

## - I
DirectContacV Root Uptake Method Uptake
Receptors TerrestrialAnimals Terrestrial B~rds, Mammals, Upland Plants Riparian Plants Reptiles, Terrestrial- 

### - Plants phaseAmphibians, Bees 

# + Direct Effects:NonEndangered species Upland Foliage/ Soil

IndividualTerrestrial Individual Terrestrial Individual A uatic Animals plants Vertebrates and Reduced Sunrival Seedling Emergence Reduced Invertebrates Growth Rates Reduced Survival Reduced Growth Vegetative Vigor and Biomass Reduced Growth Reduced Reproduction 

## - Reduced Reproduction Bioaccumulation

Indirect Perturbing Forage or Prey Availability I Effects 1 Habitat Alteration: impacting nesting ability, ability to I I I Riparian1 Wetland Foliage/Soil Surface Water, Sedimentconceptual model and subsequent analysis of exposure and effects are all based both on the parent and degradates (where data are available) of aminocyclopyrachlor. Potential emission of volatile compounds is not considered as a viable release mechanism for arninocyclopyrachlor, because Henry's Law constant (3.47 x 10-l2 atm-m3/mol) suggests that volatilizationis not expected to be a significant route of dissipation for this chemical (indicated by dashed lines in the diagram). Aminocyclopyrachlor concentrations in surfacewaters may be relatively high when significantrunoff events occur after applicationandlor spray drift to water bodies in close proximity to the treatment area occurs. Aminocyclopyrachlor has the potential to leach to ground water, which can serve as inputs to surfacewater. The conceptual model shown in 

### Figure 2 generically depicts the potential source of arninocyclopyrachlor,release mechanisms, abiotic receiving media, and biological receptor types. 

### 2.6 Analysis Plan This assessment characterizes the environmental fate and effects of arninocyclopyrachlor and determines whether there is potential for risks to non-target organisms based on the proposed use patterns. Available environmental fate, ecotoxicity, and physicochemical property data were taken from submitted studies to the Agency. The environmentalfate and effects studies underwent reviews to determine their acceptability relative to published U.S. EPA guidelines. The maximum proposed label application rates for the use of arninocyclopyrachloron non-crop areas and turf were selected for modeling environmental concentrations for this base-level deterministic (risk-quotientbased) assessment. The most sensitive toxicity endpoints from surrogate test species are used to estimatetreatment-related effects on survival,growth, and reproduction. Estimated environmental concentrations (EECs) used in terrestrial and aquatic ecological risk assessments are based on the parent aminocyclopyrachlor compound. Because toxicity data has not been submitted for any of the degradates, EECs were not calculated for any degradates; however the total toxic residue approach was used to describe potential risks. For the aquatic assessment, EECs are initiallyproduced by GENEEC. If LOC exceedances were to occur when comparing EECs to the toxicity values, PRZMIEXAMS would then be used to refine exposure estimates.For the terrestrial assessment, EECs are produced by T-REX and TerrPlant. To evaluate the spatial extent of risk to non-target terrestrial plants, AgDRIFTis used to determine at what distance from the application area LOCs are no longer exceeded. The following sections characterize the use, environmental fate, and ecological effects of aminocyclopyrachlor and use the risk quotient (ratio of EEC to toxicity value) approach to estimate the potential for adverse effects on non-target terrestrial and aquatic organisms. This risk quotient-based approach does not provide a quantitative estimateof likelihood and/or magnitude of an adverse effect. Such estimates may be possiblethrough a more refined, probabilistic assessment; however, they arebeyond the scope of this base-level assessment. 

### 2.6.1 Measures ofEffect and Exposure Table 2.2 lists the measures of environmental exposure and ecological effects used to assess the potential risks of arninocyclopyrachlorto non-target organisms (U.S. EPA, 2004).

### Table 2.2. 

### Measures ofEnvironmental Exposure and Ecological Effects Used to Assess the Potential Risks of Aminocyclopyrachlorto Non-targetOrganisms Assessment Endpoint 

## 1 Measures ofEffect 

## I Measures ofExposure 

### 1Abundance (i.e., survival, IBobwhite quail/ mallard duck acute oral LDS0( 

### I reproduction, and growth) of individuals and populations of birds

Abundance (i.e., survival, reproduction, and growth) of individuals and populations of mammals Abundance (i.e.,survival, reproduction, and growth) of individuals and communities of freshwater fish

Abundance (i.e., survival, reproduction, and growth) of individuals and communities of freshwater invertebrates Bobwhite quail/ mallard duck sub-acute dietary LCs0 Bobwhite quail/ mallard duck chronic reproduction NOAEC and LOAEC Laboratory rat acute oral LD50 Laboratory rat Zgeneration NOAEC and LOAEC Rainbow trout and bluegill sunfishLCs0
Rainbow trout and/or bluegill sunfish NOAEC and LOAEC

Abundance (i.e., survival, reproduction, and growth) of individuals and communities of estuarinelmarinefish and invertebrates



### 2.6.2 

### Data Gaps No environmental fate data gaps were identified. I Maximum residu s on food items (fol'ar) 

# 1

I I I Peak EE~

I I 60-day averagkEEC I I Daphnid ECsO Daphnid life cycle NOAEC and LOAEC

Survival ofbeneficial insect populations and natural Lepidoptera predators Maintenance and growth of individuals and populations of terrestrial plants from standing crop or biomass Maintenance and growth of individuals and populations of aquatic plants from standing crop or biomass I Peak EE$ 2 1-dayaveragq EEC
I Sheepshead minnow acute LCs0 Eastern oyster ECS0 Mysid shrimp LCs0 Sheepshead minnow NOAEC and LOAEC Mysid shrimp NOAEC and LOAEC Honeybee acute contact LDSo

Monocot ECZ5 and NOAEC values for seedling emergence and vegetative vigor (survival and growth rate) Dicot ECZ5 and NOAEC values for seedling emergence and vegetative vigor (survival and growth rate) Vascular plant (i.e., Lemna)ECS0 and NOAEC values for growth rate and biomass measurements Non-vascular plant (i.e., green algae)ECSo and NOAEC values for growth rate and biomass measurements I

I Peak EE~ 60-day averagq
- Single Maximum

application EEC

rate 2 1 -day averam EEC

Estimates of run0 and spray drift to non-targ t areas 

# 1

I

, Peak EEC( IData gaps for environmental effects were assigned a low or high priority based on their potential to add value to the ecological risk assessment. While still considered data gaps according to 40 CFR Part 158, low priority studies areunllkely to change risk determinations because alternate methods and weights of evidence (i.e.,acute-to-chronic ratio, scaling factors, or considerationof environmentally relevant concentrations relative to effects thresholds) can be used in the absence of data. High priority studies are needed to characterize potential risks by eliminating uncertainties for both non-listed and listed species that cannot be accounted for using alternate methods or weights of evidence. It is importantto note that a study that is currently assigned a low priority based on its potential to add value could be changedto high priority based on future proposed uses, submitted data, and/or incidents. The following environmental effects data gaps were identified: 

### Acid Avian Acute Oral Toxicity Test (850.2100): Data are required for one passerine species and either one waterfowl species or one upland game bird species for terrestrial, aquatic, forestry, and residential outdoor uses. The current method of calculating a weightadjustedLDsousing bobwhite quail or mallard duck data may over- or under-estimate risks to passerines because these birds may metabolize the chemical differently. Because the 850.2100 guideline has not yet been finalized, protocols for the study of passerine species shouldbe submittedto EPA for approval prior to study initiation. This study has a 

### low priority based on its potential to add value to the ecological risk assessment. Avian Reproduction Toxicity Test (850.2300): Data are required for both an upland game and waterfowl speciesfor the proposed use patterns. The submitted studies were classified as invalid due to improper husbandry practices (cage sizes that were much smaller than those recommended in the guideline) that may have caused incidental mortalities in quails and reduced egg production in mallards (see 

### Section 4.2.1). Because of the lack of avian reproduction data, potential chronic risks to birds cannot be precluded for non-listed and listed species. This study has a 

### high prioritybased on its potential to add value to the ecological risk assessment. EstuarineIMarineFish Early-life Stage Toxicity Test (850.1400):The proposed use patterns indicate that aminocyclopyrachlor may enter estuarinelmarine environments.The acute-to-chronic ratio cannot be used to predict potential chronicrisks to estuarinelrnarine fish because there were no definitive acute or chronic values for the acid. In addition, the acute estuarinelmarine fish studyproduced a non-definitiveLC50. This study has a 

### low priority based on its potential to add value to the ecological risk assessment. Freshwater Invertebrate Life Cycle Toxicity Test (850.1300):Non dose-response mortalities were observed in the three lowest treatment levels (40%, 30%, and 40%, respectively) for the submitted freshwater daphnid study. Therefore, a NOAEC could not be established. Due to the high mortality observed in the first three treatment levels, the resulting toxicity values are not a reliable estimate of the chronic toxicity to water fleas(see 

### Section 4.1.2 for details). This studyhas a 

### highpriority based on its potential to add value to the ecological risk assessment. EstuarineMarine Invertebrate Life Cycle Toxicity Test (850.1350):Thepropos$d use patterns indicate that aminocyclopyrachlor may enter estuarinelmarine Due to the lack of 

### a definitive chronicNOAEC in freshwater chronic ratio cannotbe used to predict potential chronic risks to estuarinelmarin invertebrates.This studyhas a 

### low priority based on its ecological risk assessment. 

### Ester 

# i
EstuarineMarine Fish Acute Toxicity Test (850.1075). This study has a 

### low pri&rity based on its potential to add value to the ecological risk assessment. I I EstuarineMarine Mollusk Acute Toxicity Test (850.1025). This studyhas a 

### low priority based on its potential to add value to the ecological risk assessment. 1 EstuarineJMarine Invertebrate Acute Toxicity Test (850.1035).This studyhas a 

### fow priority based on its potential to add value to the ecological risk assessment. Aquatic Plant Toxicity Test (850.4400). This study has a 

### low priority based on i s potential to add value to the ecological risk assessment. 

# t

I Algal Toxicity Test (850.5400). This study has a 

### low prioritybased on its potent a1 to add value to the ecological risk assessment. 

# f

I 

### Salt I Thetwo proposed salt formulations specifymixing with water prior to is expected to cause the salt to dissociateto the acid in which case the to be released into the environment. Therefore, salt studies are not requested at However, if future uses enable the salt to be applied to the environment (such granular salt formulation), a full suite of acute and chronic toxicity data may adequately assess potential risks. These studies are currently in reserved status. I 

### Degradates I ECOSAR was used to predict aquatic toxicity of the degradates sinceno data weke submitted.Theresults of this modeling indicated that there are two potential deg adates of concern for aquatic organisms (see 

### Section 5.2.3). Freshwater invertebrates

### m y be chronicallyexposed to IN-LXT69 and IN-YY905. Because reliable SARs do not exist for terrestrial ecotoxicity estimation, EFED defers to HED's 

### SAR evaluation in the sence of degradate toxicity data (D370368, October 15, 2009). 

### HED determined that I -V0977 (cyclopropanecarboxylic acid) may be more toxic than the parent to mammals. I -V0977 has the potential to form in aquatic environments through aqueous photolysis an may be 

# imore mobile than the parent. Acute and chronic exposures to birds and mammals are possible. However,to determine the potential to add value to a risk assessment, the total toxic residue and comparisons of EECs to the effects thresholds approaches were used to assign a priority for the receipt of additional studies. For IN-LXT69 and IN-YY905:

o Freshwater Invertebrate Life Cycle Toxicity Test (850.1300). This study has a 

### low priority based on its potential to add value to the ecological risk assessment. For IN-V0977:

o Avian Acute Oral Toxicity Test (850.2100). This study has a 

### low priority based on its potential to add value to the ecological risk assessment.

o Avian Acute Dietary Toxicity Test (850.2200). This study has a 

### low priority based on its potential to add value to the ecological risk assessment.

o Avian Reproduction Toxicity Test (850.2300). This study has a 

### low priority based on its potential to add value to the ecological risk assessment.

o Mammalian Acute Oral Toxicity Test (870.1100). This study has a 

### low priority based on its potential to add value to the ecological risk assessment.

o Mammalian Oral Two Generation Reproduction Toxicity Test (870.3800). This study has a 

### low priority based on its potential to add value to the ecological risk assessment. 

### 3 Exposure 

### Analysis 3.1 

### Use Characterization Aminocyclopyrachlor, a systemic herbicide that is the first member within the new pyrimidine carboxylic acid class of chemistry, is proposed for registration under FIFRA. Aminocyclopyrachlor acid (DPX-MAT28) and aminocyclopyrachlormethyl ester (DPXKJM44) are the two technical active ingredients;the acid is also formulated into' aminocyclopyrachlor potassium salt. Due to the observed rapid hydrolysis of the methyl ester in environmental systems and dissociation of the potassium salt to the acid in tank mixtures, it is appropriateto bridge data for the salt to the acid and terrestrial and chronic aquatic data for the ester to the acid (see 

### Section 2.2.3). However, it is possible, based on the submitted data, that aquatic organisms could be exposed to the ester on an acute basis. Because of the possibility of acute exposure combined with the submitted data showingthat the ester is more acutely toxic to aquatic organisms than the acid, acute aquatic toxicity data for the ester is not bridged to the acid.According to the proposed labels, aminocyclopyrachlor may be used against a variety f registration for non-crop and turf uses. 

# 0 broadleaf weeds, woody species, vines, and tall grasses.The registrant is seeking initia;

### i For non-crop use, aminocyclopyrachloris a dispersible granule that is mixed in water be applied by aerial or ground applicationmethods for pre- or post-emergence for broadleaf weeds and grass species. A single application of 0.284 lb a.e./acre can yearly maximum application rate of 0.284 lb a.e./acre. For residential or commercialturf use, aminocyclopyrachlor is applied with a fertiliz granule that allows selectivepre- or post-emergentbroadleaf weed control in cool se certain warm seasonturf grasses on lawns (residential, industrial, and institutional), parks, cemeteries, athletic fields, and sod fields. Commercial turf uses can also be spray as soluble concentrate and water-dispersible granule formulations are propo registration. Aminocyclopyrachlor may control every major broadleaf weed, som include dandelion, clover, plantains, wild violet and ground ivy. Aminocyclopyr applied only by ground applicationmethods for turf uses. Three applicationsof 0.108 a.e./acrecan be applied with a 30-day application interval for a yearly maximu of 0.324 lb a.e./acre (commercial use rate).
, 

### Table 3.1 summarizes the proposed applicationrates and methods for 29 end-useprodu ts. Four products also contain other active ingredients (sulfometuron, chlorsulfuron, metsulfuro 

# 4 and imazapyr); however, this assessmentonly addressespotential risks due to exposure to aminocyclopyrachlor.

### Table 3.1 does not include the technical labels or the concentrate labels (352-TIG, 352-TIE, 352-TOA, 352-TOL, 352-TIU).

contains sulfometuron and chlorsulfuron)GroundIAerial and imazapyr) DuPontTM DPX-Q2B39 Herbicide (Also contains metsulfuron) DuPontTM DPX-QKJ02 Herbicide (Also contains chlorsulfuron) 352-TON (ester) 352-TOR

(ester) 53.6

53.6

0.094
0.094

0.094

0.108

0.100

0.096

0.108

0.100

0.090 3 (14 days) 3 (14 days) 3 (14days) 3 (30 days) 3 (30 days) 3 (30 days) 3 (30 days)
3 (30 days) 3 (30 days) GroundAerial
-WDG GroundAerial
-WDG

0.282
0.282

0.282

0.324

0.300

0.288

0.324

0.300

0.270 Turf: ProfessionalUse DuPontTM DPX-KJM44 80XPTurfHerbicide DUPontTM DPXMAT28 240SL Turf Herbicide DUPontTMDPXMAT28 50SGTurf Herbicide DuPontTM DPX-KJM44 0.064G TurfHerbicide 

## +Fertilizer DuPontTM DPX-KJM44 0.053GTurf Herbicide 

## +Fertilizer DuPontTM DPX-KJM44 0.032GTurfHerbicide 

## +Fertilizer DuPontTM DPXMAT28 0.06G Turf Herbicide

### +Fertilizer DuPontTMDPXMAT28 0.05GTurf Herbicide

## +Fertilizer DuPontTM DPXMAT28 0.03G Turf Herbicide

### +Fertilizer 

### Turf:ConsumerUse 75 

### *

50

0.06

0.05

0.03

0.06

o.05

o.03 Products 352-TOE

(ester) 352-TOG

(salt) 352-T0U

(acid) 352-~0~

(ester) 352-~01

(ester) 352-~00

, (ester) 352-1RE

(acid) 352-IRG

(acid) 352-IRU

(acid) Products 0.268

0.268

Ground -WDG

Ground - SC

Ground -WDG

Ground - G

Ground - G

Ground - G

Ground - G

Ground - G

Ground - G

0.075 Ground - G 0.068 DuPontTMDPXMAT28 0.068G Lawn Herbicide

### +Fertilizer 1

1

2 (42 days) 352-1RL

(acid) 0.268

0.268

0.150

### Table 

### 3.1. Proposed Application Rates for 

### 29 Products ContainingAminocyclopyracblor

DuPontTM DPX-KJM44 0.073GLawn Herbicide 

### +Fertilizer DuPontTM DPX-KJM44 0.065GLawn Herbicide 

# -+Fertilizer

maximum annual application rate. - - -- DuPontTM DPX-KJM44 0.059GLawn Herbicide 

### +Fertilizer DuPontTM DPX-KJM44 0.053GLawn Herbicide 

### +Fertilizer DuPontTM DPX-lWVf# 0.049G Lawn Herbicide

### +Fertilizer DuPontTM DPX-KJM44 0.039G Lawn Herbicide 

### +Fertilizer DuPontTM DPX-KJM44 0.037G Lawn Herbicideu Fertilizer DuPontTM DPX-KJM44 0.033G Lawn Herbicide

### +Fertilizer DuPontTM DPX-KJM44 0.03G Lawn Herbicide 

### +Fertilizer DuPontTM DPX-KJM44 0.027G Lawn Herbicide

### +Fertilizer DuPontTM DPX-KJM44 0.024GLawn Herbicide 

### +Fertilizer DuPontTM DPX-KJM44 0.02G Lawn Herbicide 

### +Fertilizer 'WDG = water dispersible Maximum Singk Application Rate (Ib a.eJacre) Product

352-INN (ester) 352-INR

(ester) % a.e. EPA File (a.i. form)

'1f not specified onlabel, number of applicationsmay have been calculatedbased on maximum singleapplicatibnrate and 352-1NE

(ester> 352-ING

(ester) 352-IpJU

(ester) 352-JNL

(ester> 352-IN*

(ester) 352-INT

(ester)
352-INI (ester) 352-m0

(ester) 352-IRN

(ester) 352-IRR

(ester) granule; SC Application 

# ' '~omuiation TY pe' Maximum Number of ~~~licationsl~ea? (Application

Interval)

0.069

0.061 Maximum Application Ob a.eJacre)

0.055

0.05

0.046

0.037

0.035

0.031

0.028

0.025

0.023

0.01 8

= soluble Ground -G

Ground -G

Ground - G

Ground - G

Ground - G

Ground - G

Ground -G

Ground -G

Ground - G

Ground - G

Ground - G

Ground - G concentrate;G = 0.075

0.075

0.075

0.075

0.050

0.050

0.038

0.038

0.038

0.038

0.025

0.025 granule. 

### 1 2 (42 days) 

# 1

2 (42 days) 0.150

0.150
2 (42 days) 2 (42 days)
2 (42 days)
2 (42 days)
2 (42 days) 0.150

0.150

0.100

0.100

0.076

2 (42 days) 

# I
0.076
2 (42 days) II 0.076
2 (42 days) 1, 0.076

2 

### 1 (42 days) 

# , I 0.050
2 (42 days) 1 0.050 I

### 3.2 ExposureAssessment 3.2.1 Environmental Fate and Transport Characterization Environmental fateproperties for aminocyclopyrachlor acid (DPX-MAT28) and the end-use products aminocyclopyrachlor methyl ester (DPX-KJM44) and aminocyclopyrachlor potassium salt are listed separatelyin 

### Tables 3.2,3.3, and 

### 3.4, respectively. Aminocyclopyrachlor's major route of degradationis aqueous photolysis. The compound is expected to degrade with a half-life of 1.2 days in natural (pH 6.2) water and 7.8 days in pH 4 buffer solution. Aminocyclopyrachlor is stable to hydrolysis at pH 4,7, and 9. Aminocyclopyrachlor is expected to be highly mobile to mobile. It is non-volatile (4.9 x 10'~ Pa. at 25°C; 3.7 

### x low8 

### mm H~; MRID 475598-18 with KH= 

### 3.47 x 10-l2 atm-m3/mol;MRID 475598-20) and highly soluble (2810 mg/L at 20°C; MRID 475598-16) in water. Therefore, dissipationof aminocyclopyrachlorfrom the application site is expected to occur predominantly via aqueous photolysis,runoff, and leaching. Arninocyclopyrachlor was detected at soil depths of 70 - 

### 90 cm at 365 days (MRID 475751-02), which indicates that leaching of residues into ground water may occur. Additionally, off-sitemovement of aminocyclopyrachlor is expected through spray drift from aerial and ground spray.

Hydrolysis

[161-11

Aqueous Photolysis [161-21 pH 4:t 112 = stable @ 50°C pH 7:t = stable @ 50°C pH 9:t 112 = stable @ 50°C ObservedDTsO > 5 days
pH 4 buffer: t = 7.8days @ 20°C ObservedDTsO 

## - 168 days Natural Water (pH = 6.2): t = 1.4days @ 20°C Observed DTsO 

## - 29 days Transformation products: 1. 5-Chloro-2-cyclopropyl-pyrimidin-4-ylamine (IN-LXT69) - maximum 16.1 % of the applied found only in pH 4 buffer. Degradate found increasing over time. 2. 4-Cyano-2-cyclopropy1-1H-imidazole-5-carboxylic acid (INQFH57)-maximum 13.8% of the applied in pH 4 buffer. Degradate found increasing over time. Maximum 33.1% of the applied in natural water (pH = 6.2). 3. Cyclopropanecarboxylicacid (IN-V0977) - maximum 12.4% of the applied in pH 4 buffer. Maximum 14.6% of the applied in natural water (pH = 6.2). Degradate increasing over time especially in natural water. 475602- 10

475602- 1 1Soil Photolysis [161-31

AerobicAquatic

Metabolism [162-41

AnaerobicAquatic Metabolism [162-31 the applied in pH 4 buffer. Maximum 1 1.7%of the applied in natural water (pH = 6.2). Degradate increasing over time in both 

# ~ systems. 

# 1

I t = 129days @ 20°C 

# 1 Observed DT50> 15days 

# ~ Transformation products:: 

# 1
1. 5-Chloro-2-cyclopropyl-pyrimidin-4-ylamie(IN-LXT69) - maximum 4.9% of the applied found at 7 days (15 day study 

# '

duration). 2. Non-extractableResidues -maximum 17.2% of the applied found at 15days (15 day study duration).

Sand-Water: Observed DT50> 100days (W, S,TS)

## ' Silt-loam-Water: Observed DT50> 100days (W, S,TS) Transformationproducts: 1. 5-Chloro-2-cyclopropyl-pyrimidin-4-ylamine(IN-LXT69)-For Sand-Water: maximum 2.3% in water fraction, 1.0% in sediment fraction, 2.3% in total system. For Silt-Loam-Water: maximum 2.4% in water fraction, 1.2%in sediment fraction,2.4% in total system. Note: Analysis of the test substance standard showed a small amount of IN-LXT69; therefore, it appears likely that the maximum percent of applied dose at Day 0 is a contaminant and not a transformationproduct. 2. Carbon Dioxide: -For Sand-Water: maximum 0.70% of the applied at 100days (100 day study duration). For Silt-Loam-Water: maximum 0.20% of the applied at 100 days (100 day study duration). COzincreasing throughout study. 3. Non-Extractables -For Sand-Water: maximum 6.5% of the applied at 100 days (100 day study duration). For Silt-Loam-Water: maximum 11.1 % of the applied at 100days (100 day study duration). COPincreasingthroughout study.

ppp~~p pp~~ Total System: t = 1733days (stable) Observed DTS0 > 120days Observed DT50> 365 days (W ,S, TS) Transformation products: 1. 5-Chloro-2-cyclopropyl-pyrimidin-4-ylamine (IN-LXT69) - 475602-13

475602- 16

I

I 

# ~

I 475602-17 I I 

# iapplied at 100days (100 day study duration). For Silt-Loam-Water: maximum 0.20% of the applied at 100days (100 day study duration). C02 increasing throughout study. 3. Non-Extractables: maximum 17.1 % of the applied at 180days (365

ObservedDTS0 

## - 3 10days Transformation products: 1. 5-Chloro-2-cyclopropyl-pyrimidin-4-ylami (IN-LXT69) -For Sassafras soil, maximum 2.9% of the applied at 3 days (260 day

Aerobic Soil Metabolism [162-11 2. Carbon Dioxide: -For Sassafras soil: maximum 23.1% of the applied at 360 days (360 day study duration). C02 increasing throughout study. 3. Non-Extractables: -For Sassafras soil: maximum 24.4% of the applied at 300 days (360 day study duration).

Nambsheim: t =433 days (non-linear) Observed DTS0 > 120days Tama: t = 114days ObservedDTS0 

## - 110days Drummer: t = 126days Observed DT50

## - 110days Transformation products: 1. 5-Chloro-2-cyclopropyl-pyrimidin-4-ylami(IN-LXT69) -For Nambsheim soil, maximum 4.0% of the applied at 0 days (120 day study duration). For Tama soil, maximum 4.2% of the applied at 0 days (120 day study duration). For Drummer soil, maximum 6.4% of the applied at 0 days (120 day study duration). 2. Non-Extractables: For Nambsheim soil, maximum 13.0%of the applied at 120days (120 day study duration). For Tama soil, maximum 43.2% of the applied at 120 days (120 day study duration). For Drummer soil, maximum 39.3% of the applied at 120 days (120 day study duration). Sorption increasing throughout study. 475602-2 1Anaerobic Soil t = 6932 days (stable)

Soil type: Drummer Clay Loam AdsorptionKd:0:98 AdsorptionK,: 26

Freundlichadsorption Kfoc: 24.8 DesorptionConstants: Not Determined Soil type: CaliforniaLoam AdsorptionKd: 0.03 Adsorption KO,:5.2 Organic Carbon (%) = 0.5

Adsorption1 Desorption

(%and KO, in L K~-') [163-11 Freundlich adsorption Kf:0.004 Freundlich adsorption Kfo,:0.8 lln: 0.5167 Desorption Constants: Not Determined Soil type: Nambsheim Sandy Loam Adsorption Kd: 0.03 Adsorption &: 2.0 Organic Carbon (%) = 1.3 Clay (%) = 7 Freundlich adsorptionKf:0.016 Freundlich adsorption Kfoc: 1.2 1111: 0.0871 DesorptionConstants: Not Determined Soil type: Lleida Silty Clay Adsorption &:0.05 Adsorption KO,:3.2 Organic Carbon (%) = 1.6 Clay (%) =45 Freundlich adsorption Kf:0.066 Freundlich adsorption Kf,: 4.1 lln: 1.046 Desorption Constants: Not Determined Soil type: Sassafras#16 Sandy Loam Adsorption Kd:0.27 Adsorption KO,: 22

. Organic Carbon (%) = 1.2 Clay (%) = 13 I 

## ~ 

# ~

# i 

# I I 

# i 1 

## i 1
I I 1 I I 

# !
I 1 I i I I I 

# 1

I ICanada Bare Soil: 0-5em. Dissipation t = 126days

California Bare Soil:

Terrestrial Field

Dissipation

[164-11

'W =Water; S = Sediment, TS = Total System (sum of concentrationsin water and sediment extracts) Possible leacher - detected at 70-90cm. No major transformation products detected. Georgia turf: Grass Dissipation t = 22.4 days ObservedDT50

### - 4.3 days 0-5 em: Dissipation t = 27 days Observed DTS0 

## - 10.8 days Possible leacher -detected at 15-30 cm. Canada turf: Grass. Dissipation t = 24.2 days Observed DT50

## - 5.4 days 0-5 em: Dissipation t = 38 days Observed DTSo 

## - 21 days Possible leacher -detected at 50-70 cm. Transformation product detected: 5-Chloro-2-cyclopropyl-pyrimidin-4- ylamine (IN-LXT69) Canada turf: Grass. Dissipation t 112 = 7.2 days Observed DT50

## - 3.3 days 475602-22

475602-23Hydrolysis [161-11

Aerobic Soil Metabolism [162-11

Terrestrial Field

Dissipation

[164-11 t, =26.9 days @ 40°C at pH 4 t%=51.7 days @ 20°C at pH 7 k = 0.3 days @ 20°C at pH 9
pH 4 buffer: t =4.1 days Observed DT50> 2 days Degradates: 1. 6-Amino-5-chloro-2-cyclopropylpyrimidine-4-cboxylic acid (parent aminocyclopyrachlor) -maximum 3.3% of the applied at 8 hours (2 day study duration). 2. 5-Chloro-2-cyclopropyl-pyrimidin-4-ylamine(IN-LXT69) - maximum 9.3% of the applied at 2 days (2day study duration). 3. Cyclopropanecarboxamide (IN-Q3007) -maximum 7.8% of the applied at 2 days (2 day study duration).

Half-life could not be accurately calculated because of therapid transformationto the aminocyclopyrachloracid (< 1% of the applied remaining after 3 days).
Canada Bare Soil: 0-5 cm Dissipation t = 7.7 days Observed DTqn 

## - 4.6 days CA Bare Soil: 0-5 cm. Dissipation t = 3.8 days Observed DTS0 

## - 1.2days GA turf: Grass. Dissipation t 112 = 1.3days Observed DTso

## - 1day 0-5 cm: Dissipation t = 5.5 days Observed DT50

## - 1day Canada turf: Grass. Dissipation t = 5.6 days ObservedDT50 

## - 1day 0-5cm: Dissipation t =48 days Observed DT50

## - 1day '

### Mobility Based on the batch equilibriumdata, aminocyclopyrachlor displays an affinityto organic carbon. Adsorption of aminocyclopyrachlor (Kc = 2 to 26 mL/g,,, MRID 475602-19) is characterized as being highly mobile to mobile in the test soils (FA0 Classification; U.S. EPA, 2006). Desorption constants were not provided. However, 13 - 39% of non-extractable residues were found in an aerobic soil metabolism study (MRID 475602-21). Sufficient extractionmethods were used and sorptionincreased throughout the study. Aminocyclopyrachlor is non-volatile (4.9 x lod Pa. at 25°C; 3.7 x mm Hg; MRID 475598- 18and 

### KH= 3.47 x atm-m3/mol;MRID 475598-20) and highly soluble (2810 mg/L at 20°C; MRID 475598-16) in water. Therefore, dissipationof aminocyclopyrachlor is expected to occur predominantly via runoff and leaching.Aminocyclopyrachlor was detected at soil depths of 70 -90 cm at 365 days (MRID: 475751-02),which indicates that leaching of residues into ground water may occur. 

### Degradation Considering biodegradation,arninocyclopyrachloris persistent in aerobic aquatic (tllz not determined;observed DTso

### > 100 days; MRID 475602-16) and aerobic terrestrial environments (tIl2 = 315 days; MRID 475602-14). 

### In addition, it is relatively stable in anaerobic aquatic (tln= 1733 days; MRID 475602-17) and anaerobic terrestrial environments (tia = 6932 days; MRID 47560215). Considering abiotic degradation,aqueous photolysis (MRID 475602-1 1)is the major route of degradation and aminocyclopyrachlor is expected to degradewith a half-life of 1.2days in shallow, clear, and well-lit natural (pH 6.2) water bodies and 7.8 days in pH 4 buffer solution. However, it is slowlyphotolyzed on soil (tllz= 129 days; MRID 475602-13). Aminocyclopyrachlor is stable to hydrolysis (MRID 475602-10) at pH 4,7, and 

### 9. Dissipation occurred with half-lives ranging from 22 to 126 days in terrestrial field dissipation studies conducted in the continental United States and Canada (MRID 475751-02,475602-22, 475602-23, and 475602-24).Degradates of Concern I 1 The major environmentaldegradates of aminocyclopyrachlor include IN-LXT69, IN-Q H57, IN-Q3007, IN-V0977, IN-YY905, C02and an unidentified aqueous photoproduct (Ta

# ," le 3.5). Most of the major degradates formed under aqueous photolysis and were increasing 

### in mount at study termination.Ecological risks were quantified for the parent arninocyclopyrachlor acid only due to lack of toxicity data for the degradates. ECOSAR was used to predict toxicity of the degradates to aquatic organisms (see Section 5.2.3), and because of the lack of submitt d toxicity data, the total toxic residue (TTR) approach was explored. However, EECs we e not calculated for degradates IN-LXT69 and IN-YY905 because the major degradation pro ess of aminocyclopyrachlor (aqueous photolysis) was not a significant component of residue

target organisms due to exposure to the degradates can be qualitatively described. 

# i

calculation in 

### GENEEC (see Section 5.2.3). Structureactivity relationships (SARs) we e also used to predict the toxicity of the degradates to terrestrial organisms to determine what oxicity data is required for a comprehensive assessment. Using these approaches, potential risk to non- 

# I

### 3.2.2 Aquatic Exposure Estimates for Aminocyclopyrachlor (unidentified)

A Tier I screening-level surface water exposure for aquatic risk assessment was conducted for the Section 3 proposed new chemical registration. Modeled application rates represent the maximum use patterns of the proposed labels for non-crop and turf use. Pre- and post-emergent spray applications (aerial and ground spray for non-crop areas; ground spray only for turf) and granular applications (ground only for turf)are proposed (see 

### Table 3.1). The aquatic exposure estimatespresented in this assessment were based on the use of models as no surface and ground water monitoring data is available for aminocyclopyrachlor within the continentalU.S. To simulate surface water exposure for the ecological risk assessment, the Tier 

### I GENEEC2 model was used. 

### GENEEC2Model Inputs for Aminocyclopyrachlor (unidentified)

The GENEEC (GENeric Estimated Environmental Concentration) model, a Tier 

### I computer program, uses the soillwaterpartition coefficient and degradation kinetic data to estimaterunoff from a ten hectare field into a one hectare by two meter deep "standard"pond. This first tier is designed as a coarse screen and estimates conservative pesticide concentrations in surface water from a few basic chemicalparameters and pesticide label use and application information.Tier 

### I is used to screen chemicalsto determine which ones potentially pose sufficient risk to warrant higher level modeling. GENEEC is a program to calculate acute as well as longer-term estimated environmental concentration (EEC) values. It considers reduction in dissolved pesticide concentration due to adsorption of pesticide to soil or sediment, incorporation, degradation in soil before washoff to a water body, direct deposition of spray drift into the water body, and degradation of the pesticide within the water body. It is designed to mimic a high-end PRZM-EXAMS simulation. Additional 16.8 Aqueous Photolysis MRID 475602- 11information on this and other models canbe found at: 

### http://www.epa.g;ov/oppefed1/models/water/index.htm. The aquatic exposureis estimated for the maximum application pattern to a 10-hafield a 1-hapond, 2-m deep (20,000 m3)with no outlet.Exposure estimates generated using standard pond are intended to represent a wide variety of vulnerable water bodies that ( the top of watersheds including prairiepot holes, playa lakes, wetlands, vernal pools, 

### n and natural ponds, and intermittent and first-order streams. As a group, there are factor make these water bodies more or less vulnerable than the standard surrogatepond. Stat bodies that have larger ratios of pesticide-treated drainage areato water body volume 

### v expected to have higher peak EECs than the standard pond. These water bodies will be smaller in size or have large drainage areas. Smallerwater bodies have limited storage and thus may overflow and carrypesticide in the discharge, whereas the standard pond discharge. As watershed size increases beyond 10-ha,it becomes increasinglyunlikelj entire watershed is planted with a non-major single crop that is all treated simultaneou: the pesticide. Headwater streams can also have peak concentrations higher than the stai pond, but they likelypersist for only short periods of time and are then carried and diss downstream. 

### Table 3.6 summarizes the model input parameter values used in GENEEC2to estimatc aminocyclopyrachlor concentrations in aquatic systems for ecological risk assessment.

# 'I'
3(

i S :I(

c

I' 

### $1 nt i.

bordering his ;cur at m-made that 2 water auld be :ither apacity ias no that the 

### y with dard pated

Method of Application spray zonelbuffer (non-crop

### - parent)

IncorporationDepth (inches) Broadcast Application-MIUD 475602-16

MRID 475602-1 1

The estimated environmentalconcentrations (EECs) for the parent aminocyclopyrachlor acid for non-crop and turf use are listed in 

### Table 3.7. In general, aerial applications resulted in higher EECs compared to ground applications. Maximum concentrations arehighlighted 

### in bold. The GENEEC output files are listed in 

### Appendix A.

1app @ 0.284 a.e./acre



### Aquatic Exposure Monitoring and Field Data Since aminocyclopyrachlor is a new active ingredient, no national-scalemonitoring data were available for this chemical.3.2.3 

### Terrestrial Wildlife Exposures I

I Terrestrial wildlife exposure estimates are typically calculated for birds and mammals emphasizing a dietary exposure route for uptake of pesticide residues on vegetative mat'erand insects. Birds are used as surrogates for terrestrial-phase amphibians as well as reptiles.JFor exposureto terrestrial organisms, pesticide residues on food items are estimated based assumption that organisms are exposed to a single pesticide residue in a given The residue estimatesfrom spray applications are based on a nomogram by (1972) as modified by Fletcher et 

### al. (1994) that correlated residue levels, rate, on various terrestrial items immediately following application in the residue concentration,an upper bound defined by Fletcher et 

### al. (1994), derived from literature and tolerance data. Dissipation of aminocyclopyrachlor residues on food items following single and applicationsis predicted using a first-order residue degradation half-life with v1.4.1 model. T-REX assumes a default foliar dissipation half-life estimate and McDowell, 1987). This half-life is used in lieu of aminocyclopyrachlor data, which were not submittedby the registrant. The maximumpredicted mammalian food items (dietary EECs) as a result of applicationsto in 

### Table 3.8 and 3.9. Application to non-crop areas, accordingto chosen because it represents the scenariowith the highest maximum annual application rates. Although proposed granular applicationrates are lower reason, the ~~~o/ft~ approach was not used. The residues or EECs on food items may be compared directly with sub-acute dietary data or convertedto an ingested whole-body dose (single oral dose). Single oral dose represent, for many pesticides, an exposure maximized over a single ingestion event. Sub-acute dietary estimates provide for of the dietary matrix and more extended gut. However, dietary exposure endpoints ingestion estimates are uncertain and may not be directly to field conditions. The EEC is converted to an oral dose by multiplying the EEC by the percentage of body weight consumed as estimated consumption-weighted EECs (i.e.,EEC equivalent and body size for birds (20, 100, and 1000 equivalentdoses for birds and mammals given in 

### Tables 3.8 and 3.9, respectively. Example output from T-REX is included in 

### Appendix 

### B. As predicted by HED (see 

### Section 5.2.3), the degradateIN-V0977 (cyclopropanecarbox acid)may pose additionalrisks to birds and mammals. However, because toxicity datah been submitted,EECs were not calculated.

### 3.2.4 Terrestrial and Semi-Aquatic Plant Exposures Broadleafplants/small insects Fruits/pods/seeds/large insects Granivores

Terrestrial and semi-aquaticplants may be exposedto pesticides from runoff, spray drift, or volatilization. Semi-aquaticplants are those that inhabit low-lying wet areas that may be dry at certaintimes of the year. The runoff scenario in TerrPlant v1.2.2 is: (1) based on a pesticide's water solubility and the amount of pesticide present on the soil surface and its top one centimeter, (2) characterized as "sheetrunoff" (one treated acre to an adjacent acre) for dry areas, (3) characterized as "channel runoff" (10 acres to a distant low-lying acre) for semi-aquatic or wetland areas, and 

### (4) based on runoff values of 1,2,and 

### 5% for water solubilityvalues of <lo, 10-100,and >I00 ppm, respectively. Spray drift is assumed as (1) 1% for ground application, (2) 

### 5% for aerial, airblast, forced air, and spray chemigation applications, and (3) 0% for granular applications. Currently,EFED derivesplant exposure concentrations from a singlemaximum application rate only. Exposure through volatilizationis not accounted for in this baseline assessment; however, based on the low vapor pressure, it is not expected to be a significant route of exposure. EECs for turf and non-crop areas are presented 

### in 

### Table 3.10. Example of TerrPlant output is provided in 

### Appendix 

### C. 38.34 4.26



### Table 3.10. EECsfor Terrestrial and Semi-aquaticPlants for Aerial and/or Ground Application ----- 

### to Turf and Non-crop Areas 36.55 4.06 0.90

Runoff to dry areas IhrF (0.108 Ib a.ehcre) Ground Description (granule) 25.26 2.81 0.62

Turf (0.094Ib a.e./acre) Ground (spray) Noa-cropAreas (0.284 Ib a.eJacre)

0.0054 5.86 0.65 0.14

Ground (spray) Aerial (spray 0.0047 0.0142 0.0142

### 4 Ecological Effects Analysis I 

### A search of the public ECOTOX database 

### (http://cfpub.epa.~ov/ecotox) on October 30,2009 did not yield any aquatic or terrestrial open literature studies for aminocyclopyrachlor.Thisresult is to be expected as aminocyclopyrachloris a new chemical. Therefore, only studies subrrjittedby the registrant were evaluatedto determine the effects of aminocyclopyrachlor on non-t get organisms. The Ecological Incident Information System (EIIS) was also reviewed to pr 

# "$

vide a refined characterizationof the ecological effects.As expected, no incidentswere found aminocyclopyrachlor; however, several incidents were found involving the pyridine acids (see 

### Section4.4). Runoff to semi-aquatic areas Spray drift Total for dry areas Total for semi-aquatic areas

I 4.1 

### Aquatic Effects Summary 

# ~ 0.054

0 0.0054 0.054 0.047 0.00094 0.00564 0.04794

Studies that evaluated the effects of the acid (DPX-MAT28)and the effects of the ester DPXKJM44) were submitted for aquatic flora and fauna. Toxicity classifications for those st

# i dies requiring them ranged frompractically non-toxic to slightly toxic. The acute freshwater(fishand daphnid studies showed that the ester may be more toxic than the acid. Because the subbitted data on the ester were limited, there are someuncertainties regarding the toxicity of the 

### Section 4.3). 4.1.1 

### Toxicity Effects on Fish i 0.142 0.00284 0.01704 0.14484

Two definitive studies that evaluated the acute effects of the acid to rainbow trout (MRQ 475601-23) and bluegill sunfish (MRID 475601-24) were submitted.Measured test concentrations ranged from 7.6to 122mg a.e./Lfor the rainbow trout and 7.5 to 120m a.e./L for the bluegill sunfish. There was a completelack of mortality and sublethal effects in 0th of the studies;both studies classify aminocyclopyrachloras practically non-toxic and satis y the guideline requirementsfor an acute freshwater fish study.The rainbow trout 96-hr LCsO was >I22 mg a.e./L and the NOAEC was 122mg a.e./L. Thebluegill sunfish 96-hr LCso wa >I20 mg a.e./L and the NOAEC was 120mg a.e./L.A definitive study that evaluated the acut effects of the ester to rainbow trout (MRID 475602-06) was submitted.The 96-hr LCsO was 13 g a.e./L and the NOAEC was 8.1mg a.e./L. Lethargywas the sublethal effect observed in the t o highest test concentrations.Based on these results, the ester would be classified as slightly toxic to freshwater fish. The guidelinerequirements are satisfied by this study. Results of the thr e acute freshwater fish studies are summarized in 

### Table 4.1. 

# 1 (3.142 0.0142 C .0284 C.1562A limit test study was submitted that evaluated the acute effects of the acid to an estuarine/marinefish, sheepshead minnow (MRID 475601-25). There was a complete lack of mortality and sublethal effects; the 96-hr LCsoand 96-hr ECso were >I29mg a.e./L and the NOAEC was 129mg a.e./L. The results of the study classify the acid as practically non-toxic to estuarinelmarinefish. Guideline requirements for an acute study on estuarine/marinefish are satisfied. Results of this study are summarized in 

### Table 4.2.

A 90-day chronic toxicity test was submitted that evaluated the effects of the acid on the earlylife stage of rainbow trout (MRID 475601-30) under flow-through conditions. Measured test concentrations were between 0.69 and 11mg a.e./L. There were no treatment-related effects on hatching success, time to hatch, post-hatch survival, time to swim-up, or growth at any treatment level. The 90-day LC/EC50 for all endpoints was >11 mg a.e./L, and the NOAEC and LOAEC were 11and >11 mg a.e./L,respectively. This study satisfies the guideline requirement for an early-life stage study with freshwater fish. The results are summarized in 

### Table 4.3.

4.1.2 Toxicity Effects on Invertebrates "Denotes value used for RQ calculation. Practically Non-toxic

Slightly Toxic 96-hrLC50:>I20mg a.e./L

NOAEC: 120mg a.e./L (no effects) 96-hrLC50: 13mg a.e./L*

NOAEC: 8.1 mg a.e./L (based on mortality and sublethal effects [lethargy]) 850.1075 acid (92.2%) 850.1075

ester (90.9% a.e.)



### A study was submitted that evaluated the acute effects of the acid on water fleas (MRID 475601- 26). Measured test concentrations were between 3.7 and 120mg a.e./L. The 48-hour LCsowas 39.7 mg a.e./L. Sublethal effects were observed in all but the lowest test concentration; the 48-hr NOAEC based on mortality and sublethal effects (lethargy)was 3.7mg a.e./L. Based on these results, the acid is classified as slightly toxic to freshwater invertebrates. This study satisfies the guideline requirements for an acute toxicity study with freshwater invertebrates.A study was Bluegill sunfish (Lepomis macrochirus) Rainbow trout (Oncorhynchus mykiss) Acceptable

Acceptable 475601-24

475602-06also submitted that evaluated the acute effects of the ester on water fleas (MRID 47560L-07). Measured test concentrations were between 0.92 and 30 mg a.e./L. The 48-hour LCsodas 19.9 mg a.e./L. Sublethal effects were seen at all but the lowest test concentration; the 48-hrlNOAEC based on mortality and sublethal effects (lethargy and surfacing) was 0.92 mg a.e.1L. ~$ese results classify the ester as slightly toxic to freshwater invertebrates. This study satisfie$ the guideline requirements for an acute toxicity study with freshwater invertebrates. The re these two studies are summarized in 

### Table 4.4.

NOAEC: 0.92 mg a.e./L (based on mortality and sublethal effects [lethargy and

Two studies were submitted that evaluated the effects of the acid on estuarinelmarine invertebrates. An oyster shell deposition test using the Eastern oyster (MRID produced an ICsoof >I18 mg a.e./L. observed in the highest test concentration; the NOAEC was 67 mg a.e./L. the acid as practically non-toxicto estuarinelrnarine mollusks, and the requirements. 

### A mysid shrimp acute toxicitytest 

### (MRID 4752601-28) that was >I22mg a.e./L. Because there were no significant NOAEC for this study was 122mg a.e./L. The acid is estuarinelmarine invertebrates. Guideline these two studies are summarized in

A 21-day chronictoxicity study was submitted that evaluated the effects of the acid on fleas (MRID 475601-29) under staticrenewal conditions.Measured test concentrations between 0.37 and 6.0 mg a.e./L. The 21-day LC5()for adult mortality was >6.0 mg a.e./L However, non dose-responsemortalities were observed in the 0.37,0.73, and 

### 1.5mg acid (Crassostrea 96-hr ECS0: >I18 mg a.e./L Acceptable 47560 1-27 (92.2%) 850.1035 acid (92.2%) virginica) Mysid shrimp (Americamysis bahia) NOAEC: 67 mg a.e./L 96-hr LCa: >I22 mg a.e./L NOAEC: 122mg a.e./L (no effects) Non-toxic Practically Non-toxic Acceptable 4752601 -2840%, 30, and 40%, respectively. Therefore, a NOAEC could not be established.This study is scientificallysound but is classified as supplemental. Due to the high mortality observed in the first three treatment levels, the resulting toxicity values do not provide a reliable estimateof the chronic toxicity to water fleas. Additionally,immobility was observed in all treatment levels of the second range-finding test; however, data for the range-finding tests were not provided. Finally, in the acute water flea study (MRID 475601-26), sublethal effects and mortality provided a NOAEC of 3.7 mg a.e./L;this comparison suggests a possible issue with the health of the test organisms in this chronic study. The results of this study are summarized in 

### Table 4.6.

4.1.3 

### Toxicity Effects on Plants Four studies were submitted that evaluated the effects of the acid on non-vascular plants. A 96- hour study was done with freshwaterblue-green algae (MRID 475602-01). Cell density, growth rate, and biomass were the endpoints affected with biomass being the most sensitive. The NOAEC and ECsovalues for biomass were 1.11 and 7.4 mg a.e.L, respectively. There were no differences in cell morphology between the control and treatment groups, but flocculation and aggregation of cells was observed in all treatment levels but the highest. A 96-hour study was done with the marine diatom (MRID 475602-02). There were extremely low or no inhibitions for all endpoints, which resulted in a NOAEC and EC50 value of 120 and >I20 mg a.e./L, respectively. There were no differences in cell morphology between the control and treatment groups, and flocculation, aggregation, and adherence were not observed in any group. A 72-hour study was conducted for freshwater green algae 

### (MRID 475602-03). No endpoint was inhibited by more than 50%; therefore, the EC50value was determined to be >I20 mg a.e.L. The cell density and biomass endpoints shared NOAEC and ECo5 values of 15.3 and 62 mg a.e./L. There were no differences in cell morphology between the control and treatment groups, and flocculation, aggregation, and adherence did not occur in any group. A 96-hour study was conducted on freshwater diatom (MRID 475602-04), and high inhibitions (96-99%) were reported for all three endpoints. Biomass was the most sensitiveendpoint with 

### an EC50of 38 mg a.e./L and a NOAEC of 14mg a.e./L. There were no differences 

### in cell morphology between the control and the treatment groups. There was no evidence of flocculation, aggregation, or adherence in any group. Guideline requirements are satisfied by all four studies (freshwater green algae study satisfies Tier 

### I requirements only), and they are summarized in 

### Table 4.7.A 7-day study was submitted that evaluatedthe effects of the acid on a 

### (MRID 475601-34). None of the endpoints were inhibited by more than 50%; values for frond number, frond number yield, biomass, and growth rate based on frond were >I22mg a.e./L. Frond number and frond number yield were the most sensitive with ECo5 values of 21 mg a.e./L with 

### NOAEC values of 3.75 mg a.e./L. By test there were isolated cases of chlorosis, necrosis, and dead fronds observed in all test level. 

### In the highest test level, some or all of the fronds were small, curled, all of the colonies were coagulating (not breaking apart).This study satisfies guideline requirements for a freshwater vascular plant toxicitytest and is summarized in 850.5400

acid (92.2%) 850.5400 (Tier I) acid (92.2%) 850.5400

acid (92.2%)



### 4.2 Terrestrial Effects Summary Marine diatom (Skeletonemacostatum) Green algae (Pseudokirchneriella subcapitata) Freshwater diatom (Naviculapelliculosa)

850.4400

acid (92.2%)

Thirteen studies were submitted that evaluated the effects of arninocyclopyrachlor to teriestrial non-target organisms. The plant studies were conducted using a technical end-useprodu t 

### (TEP), which was an ester formulation. Similarly, one of the avian acute oral studies and one o the mammalian acute oral studies were conducted using the ester. For the most part, 

# f

I arninocyclopyrachlorwas practically non-toxic to birds, mammals, and invertebrates.A{ expected since arninocyclopyrachloris an herbicide, seedling emergence and vegetativevigor toxicitywas affected in the plant studies. 

# ~ 4.2.1 Toxicity Effects on Birds I 96 hr EC50:>I20 mg a.e./L

NOAEC: 120mg a.e./L (no effects) 72 hr ECSo: >I20mg a.e./L 72 hr ECo5: 62 mg a.e./L NOAEC: 15.3mg a.e./L (cell density and biomass) 96 hr ECS0: 38 mg a.e./L NOAEC: 14mg a.e./L (biomass)

Duckweed (Lemna gibba)

Two acute oral toxicity studies were submitted for bobwhite quail. The study with the adid 

### (MRID475601-18) showed a complete lack of mortality and sublethal effects. Thereweke no signs of toxicity, effects on body weight, or changes in food consumptionbetween the c$ntrol and treatment groups. The 14-dayLDsO was >2075 mg a.e./kg-bw, and the NOAEL was PO75 mg 1 a.e./kg-bw. The study classifies the acid as practically non-toxic and satisfies guideline 1 requirements for an acute oral toxicitytest for an upland game bird or waterfowl speciesi The study with the ester (MRID 475602-05) did not show any mortality. There were no dinikal signs I Acceptabl&
Acceptabl?
Acceptabl?

7-dayEC5O:>I22 mg a.e./L

7-dayECo5:21 mg a.e./L NOAEC: 3.75 mg a.e./L (frond number and frond number yield) 475602-02

475602-03

475602-04

~cce~table 475601 -34of toxicity, effects on food consumption, or change in female body weight; however, there was a significant change in male body weight in the three highest treatment groups. The 14-dayLD50 was >2045 mg a.e./kg-bw, and the NOAEL was 442 mg a.e./kg-bw.This study classifies the ester as practically non-toxic, and guideline requirements are satisfied by this study. Acute dietary toxicity studies were submitted for each of the bobwhite quail and mallard duck. For the 10-day-old bobwhite quail (MRID 475601-20) and the 10-day-old mallard duck (MRID 475601-19),both studies showed a complete lack of mortality and sublethal effects. There were no signs of toxicity, effects on body weight, or changes in food consumption between the control and treatment groups. For both studies, the 8-day LCsowas >5290 mg a.e./kg-diet, and the NOAEC was 5290 mg a.e./kg-diet. These results classify the acid as practically non-toxic to juvenile bobwhite quails and mallard ducks. The four avian acute toxicity studies are summarized in 

### Table 4.9.

Chronic dietary reproduction toxicity studies with the acid were submitted for each of the bobwhite quail (MRID 475601-21) and mallard duck (MRID 475601-22). 

### In the quail study, cages were approximately six times smaller than recommended in the guideline. Seven incidental mortalities occurred in the control and all three treatment groups. It is possible that the small cage size contributedto these mortalities as external injuries, including bruising, fractures, and necrotic lesions, were observed. Therefore, the improper husbandry practices used in the study may have affected reproductive endpoints in both the control and treatment groups. The study is classified as invalid and does not satisfy guideline requirements. 

### In the mallard study, cages were approximately three times smaller than recommended in the guideline. Three incidental mortalities were observed in the control and the two lower treatment groups. It is possible that cage size may have affected the reproductive endpoints measured in this study in all treatment levels, including the controls. Additionally, sixteen hens 

### in the control and treatment groups were observedto be non-productive (less than ten eggs laid). Necropsy showed that egg yolk peritonitis was apparent in the non-laying hens. Although this endpoint may not be treatmentrelated, the health of the birds is questionable. This study is classified as invalid and does not satisfy guideline requirements.

### 4.2.2 

### Toxicity Effects on Mammals , An acute oral acid toxicity study on the rat was conducted using the up-and-down procedure (MRID 475599-34). Three female rats were dosed with 5000 mg a.e./kg-bw (acid, 92.2 o purity) and observed for fourteen days. The day after dosing, one rat had diarrhea but recovere by the next day. There were no mortalities or clinical signs of toxicity at the end of the test; ne ropsies did not show any gross lesions. The 

### LD50 was determined to be >5000 mg a.e.kg-bw, study was classified as acceptable. 

# id

the 

## I An acute oral ester toxicity study on the rat was conducting using the up-and-down pro (MRID 475600-27). Six female rats were dosed with 175,550, 1750, or 5000 mg (ester, 96.9% purity) by gavage (threerats were dosed at the 5000 mgkg-bw observed for fourteen days. One rat at the'5000 mg a.e./kg-bwtreatment on the day of dosing and hair loss (forelimbs) on days 13 and 14. and gained weight during the study. The other animals had no mg a.e./kg-bw, and the study was classified as acceptable. treatment related gross lesions were noted at necropsy. The

In a two-generation reproduction toxicity study (MRID 475751-Ol), 28 ratslsexldose exposed to the acid (90.9-92.2% purity) at dietarylevels of 0,500, 1500,5000, or 17, (equivalent to 010,36141, 1091125,3631416, and 128511454mg a.e.kg-bwlday in ma during pre-mating) for two successive generations with one litterper generation. No related effects were observed on mortality, clinical signs, or macroscopic or microscopi findings. The LOAEC for parental toxicitywas 17,000ppm (equivalentto 12851145 maleslfemales),based on decreased body weights 

### in parental males and females. Th was 5000 ppm (equivalent to 3631416 mag in maleslfemales). The LOAEC for offsp toxicitywas 17,000ppm (equivalent to 128511454mglkg in rnaleslfemales),based o body weights in the F1 and F2 pups. The NOAEC was 5000 ppm (equivalentto 363141 mag in rnaleslfemales).The LOAEC for reproductive toxicitywas not observed. The NOAE was 17,000ppm (equivalent to 128511454mglkg in maleslfemales). This study was classifie as acceptable. 

# I
I
Results of the three mammalian toxicity studies are summarized in 

### Table 4.10. 

## 1

### 4.2.3 

### Toxicity Effects on Invertebrates An acute earthworm toxicity test with the ester (MRID475602-08) was submitted and classified as supplemental because an OPPTS acute toxicity guideline does not exist for earthworms. Earthworms were exposed to the ester at concentrations between 123 and 909 mg a.e./kg-dw soil for 14days. No mortalities or behavioral abnormalities were observed in the control or treatment groups throughout the definitive exposure period. By test termination, mean weight loss was 4.33% in the solvent control and 5.41,5.36, 10.68, 12.98, and 12.18% in the 123,203,334,551, and 909 mg a.e./kg-dw soil treatment groups, respectively.The EC50was >909 mg a.e./kg-dw soil. The NOAEC and LOAEC values, based on % body weight loss, were 203 and 334 mg a.e./kg-dw soil, respectively. Division.

A study was submitted that evaluated the acute contact toxicity and acute oral toxicity of the acid on female young adult worker honey bees (MRID 475601-3 1).In the contact portion of the study, there was a complete lack of mortality and sublethal effects at any treatment level after 48 hours. The LDsowas >I00 pg a.e./bee, and the NOAEL was 100 yg a.e./bee. The contact portion of the study satisfies guidelinerequirements and classifies the acid as practically non-toxic. 

### In the oral portion of the study, there were no significant mortalities. Sublethal effects were observed at 24 hours and included one apathetic bee at the 28.09 pg a.e./bee treatment level and eight bees with coordinationproblems at the 112.03pg a.e./beetreatment level. However, these effects were not observed at 48 hours. Theresulting LCso was >112.03 pg a.e./bee, and the NOAEL was 112.03 pg a.e./bee. The Agency does not have a data requirement or an acute oral toxicity guideline for the honey bee. Therefore, the data is considered supplementalbut classified as acceptable since it was submitted in the same study as the acute contact toxicity test. The results from both the acute and contact toxicity tests are summarizedin 

### Table 4.11. Based on the toxicity values obtained from the acute contact and acute oral honey bee studies, no additional honey bee studies (foliage residue or field) are needed at this time. F1 and F2 male pup body weights) conducted by the Health Effects Toxicity

acid (90.9-92.2%) Formal reviews of n arnrnalian data were



### Table 4.11. 

### Toxic Effects in Earthworms 

### (Eisenia

### fetiaa) and Honey Bee 

### (ApismeUifera)Due to Acute Exposure to Aminocyclopyrachlor

Acute Toxicity Ester (90.9% a.e.)

850.3020 Contact Toxicity acid (92.2%) Toxicity Classification S~Y Classification Study Type OECD TG 207 ECS0: >909 mg a.e./kg-dw soil NOAEC: 203 mg a.e./kg-dw soil (% body weight) LDS0: >I00 pg a.e./bee NOAEL: 100pg a.e./bee (no effects) MRID # Toxicity Value LCso:>909 mg a.e./kg-dw soil NIA
Practically Non-toxic Supplemental

Acceptable 475602-08

475601-3 1Dry Weight



### 4.3 Comparison of Ester and Acid Toxicity Three studies were submitted that evaluated the acute effects of the ester on a freshwater fish, freshwater invertebrate, and upland game bird. Although rapid hydrolysis of the ester to the acid under environmental conditions is expectedto occur, the submitted toxicity studies do not confirm equivalent toxicity. The submitted rainbow trout ester study (MRID 475602-06) was about an order of magnitude (or more due to the acid's non-definitive

### LCso)more toxic than the acid (MRID 475601-23). The daphnid ester study (MRID 475602-07) was about twice as toxic as the acid (MRID 475601-26). While both the ester and the acid bobwhite quail studies showed aminocyclopyrachlorto be practically non-toxic based on mortality, a sublethal effect was observed 

### in the ester study; male body weight was affected by exposure to the ester (MRID 475602-05) at a level about five times lower than the level that produced no effects by the acid (MRID 475601-18). Both the acute oral mammalian studies for the acid and ester did not show any toxicity or sublethal effects (MRID 475599-34,475600-27).

### 4.4 

### Review of Incident Data As of October 30,2009, aminocyclopyrachlorhad not yet been included in the EIIS ecologicalincidents. However, the lack of reported incidents does not preclude terrestrial and aquaticnon-target organisms. An investigationof the EIIS database shows that concerns have been raised with a simi ar class of herbicides, the pyridine carboxylic acids. Severalincidents have been reported invol

# 1 ing residues of clopyralid,picloram, and aminopyralid in compost causing crop injury; sodeof these incidents have caused regulatory actions to be taken. Incidents involving aminopyralid n the United Kingdom resulted in a temporary suspension of sales of products containing 

# \ aminopyralid. Incidents involvingclopyralid resulted in the state of Washington bannin it from use on lawns and turf; the registrant subsequently voluntarily cancelled clopyralid's use on lawns in Washington. Similarly, the California Department of Pesticideregulation cancelled clopyralid's uses on residential lawns. Residues detected in lawn clippings and compos

# 1

have prompted other statesto be on alert for potential issues involving thesetypes of herbicides. I Although aminocyclopyrachlor belongs to the pyrimidine carboxylic acids family, it is systemic, and has high seedlingemergence toxicity. Therefore, aminocyclopyrachlor may end up in treated plant materials used in compost or for feed for animals whose used in compost, which has the potential to cause similar incidents as those reported for aminopyralid, picloram, and clopyralid. 

### 4.5 

### Review of 

### ECOTOX Data I I A search of the publicECOTOX database 

### (htt~://cf~ub.e~a.~ov/ecotox) was conducted n October 30,2009. No studies were found that evaluated the effects of aminocyclopyrac lor on non-target organisms. 

# 4'

I 

### 5 

### Risk Characterization 

# ~ Risk characterization is the integration of exposureand effects characterization to deter ine the potential for ecological risks to non-target organisms including aquaticlife, wildlife, an plants from the use of aminocyclopyrachlor according to the proposed labels. The risk charact rization provides an estimation and description of the risk; articulates risk assessment assumptio s, limitations,and uncertainties; synthesizes an overall conclusion; and provides the risk anagers with information to make regulatory decisions. 

# i

5.1 

### Risk Estimation: Integrationof Exposure and Effects Data 

# il Results of the exposureand toxicity effects data are used to evaluate the potential for adierse ecological effects on non-target species. For the assessment of potential risks of aminocyclopyrachlor,the risk quotient (RQ) method is used to compare exposure and mkasured acute or chronic toxicity values: 

### I RQ =

### EEC / Toxicity Valuewhere: 

### EEC is the estimated environmental concentrationgenerated by the exposure scenarios. The RQs are compared to the Agency's levels of concern (LOCs). These LOCs are the Agency's interpretive policy and are used to analyze potentialrisk to non-target organisms and the need to consider regulatory action (see 

### Appendix 

### D). These criteria are used to indicate when a pesticide's use as directed on the label has the potential to cause adverse effects on non-target organisms. 

### 5.11 Non-targetAquatic Fish, Invertebrates, and Plants The highest surfacewater concentrations resulting from aminocyclopyrachlor application were predicted using a non-crop scenario. Because the turf single application rates were lower than the maximum single application rate for non-crop areas, turf scenarios produced lower surfacewater concentration estimates.Application scenarios were selected to represent the entirerange of soil and environmental conditions of the proposed actions. EECs arebased on aminocyclopyrachlor parent. This conservativeapproach will approximate maximum exposure. Peak EECs were compared to acute toxicity endpoints to derive acute risk quotients. The 21-day EECs were compared to chronic toxicity endpoints (NOAEC values) to derive chronicrisk quotients for invertebrates. The 60-day EECs were compared to chronic toxicity endpoints (NOAEC values) to derive chronicrisk quotients for fish. 

### Fish For the acid, no toxicity was observed at 

### the highest concentrationtested (120-129rng a.e./L)for freshwater and estuarinelrnarine fish. Therefore, acute risk quotients were not calculated and RQs would not be expected to exceed LOCs. For the ester, an LCsowas observed to be 13mg a.e./L for bluegill sunfish. The resulting RQ of <0.01 (Peak EECIToxicity Value = 16.86ppbl13,OOO ppb = 0.0013) does not exceed any of the

. acute LOCs for the highest proposed application rate. The NOAEC produced by the chronicrainbow trout studywas 11mg a.e./L (acid).Theresulting RQ of ~0.01 (60-dayEECIToxicity Value = 16.64ppbll1,OOO ppb = 0.0015) does not exceed the chronicLOC for the highest proposed application rate. A chronic estuarinelrnarine fish study was not submitted.The acute-to-chronic ratio cannot be used to predict potential chronicrisks to estuarinelrnarine fish because the most sensitive acute freshwater fish uses the ester whereas the submitted chronicfreshwater and acute estuarinelmarine fish studies use the acid. 

### In addition, the acute estuarinelmarine fish studyproduced a non-definitiveLCso. 

### Freshwater Invertebrates For the acid, an LCs0of 39.7 mg a.e./Lwas observed. The resulting RQ of <0.01 (Peak EECIToxicity Value = 16.86ppb/39,700 ppb =0.00042)does not exceed any of the acute LOCs for the highest proposed application rate.Similarly, for the ester, an LCsoof 19.8mg a.e./L was observed.Theresulting RQ of <Q.Ol'(Peak EEClToxicity Value = 16.86ppbl19,800ppb = 0.00085) does not exceed any of the acdte LOCs for the highest proposed application rate. A definitive NOAEC was not produced by the chronic daphnid study (acid). The considered supplementaland the data did not allow for quantificationof potential Chronic risks are assumed for non-listed and listed species due to lack of 

### EstuarineIMarine Invertebrates 

### I Mortality was not observed in the Eastern oyster shell deposition toxicity test; NOAEC of 67 mg a.e./L was observed. The resulting RQ of <0.01 (Peak 16.86ppbl67,OOO ppb =0.00025) does not exceed the LOCs. No observed in the mysid shrimp acute toxicity test. Therefore, RQs would not be expected to exceed LOCs. A chronic estuarinelmarine invertebrate study was not submitted.Because the chronic f eshwater invertebrate study did not produce a definitiveNOAEC, the acute-to-chronic ratio cann t be used to estimate potential chronicrisks to estuarinelmarine invertebrates. Chronicrisks are a sumed for non-listed and listed species due to lack of acceptable data. 

# 1

I 

### Aquatic Plants 

# 1
Of the four non-vascularplant and one vascularplant studies submitted, blue-green algap produced the lowest ECsoat 

### 7.4 mg a.e./L. The resulting RQ of <0.01 (Peak
= 16.86ppb/7,400 ppb =0.0023) did not exceed the acute LOC for using the NOAEC of 1.1mg a.e./L for blue-green algae, the resultingRQ of <0.01 (Pe EEClToxicity Value = 16.86/1,100ppb 

### =0.015) did not exceed the 

### 5.1.2 

### Non-targetTerrestrialAnimals I I 

### Birds I I For the acid, no mortality or effects were observed in the bobwhite quail acute oral toxiclitytest and the bobwhite quail and mallard duck acute dietary toxicity tests. Therefore, acute ris quotients were not calculated and RQs would not be expected to exceed LOCs. For the ester, no mortality was observed. However, male body weight was affected at a tkeatment level that was almost five times lower 

### (442 mg a.e./kg-bw)than the level that produced sublethal affects with the acid (2075mg a.e./kg-bw).The T-REX model does not quantify potential risks due to acute sublethal effects; refer to 

### Section 5.2.2 for a potential risk due to reduced male body weight. The submitted avian reproduction studies were classified as invalid (see 

### Section 4.2.1 fo details). Chronic reproductiverisks to birds are assumed-fornon-listed and listed species due to lack of acceptable data. 

# I

### Mammals The acute oral rat studies submitted for both the acid and the ester did not show any mortality or signs of sublethal effects. Therefore, acute risk quotients were not calculated and RQs would not be expectedto exceed LOCs. The chronic two-generation rat reproduction studyproduced a NOAEC of 5000 ppm and a corresponding estimated daily dose of 

### 363 mg a.e./kg-bw.There were no exceedancesof the chronic LOC at the highest single maximum application rate (0.284 lb a.e./acre). Chronic mammalianRQs are summarized in 

### Table 5.1.



### Terrestrial Invertebrates EFED does not currently quantify risks to non-listed terrestrial non-target insects. Risk quotients are not calculated for these organisms. Thehoney bee is used as a surrogate for all terrestrial invertebrates. Aminocyclopyrachloris classified as practically non-toxicbased on the acute contact honey bee study >I00 pg a.i./bee). Similarly, the acute oral study resulted in a nondefinitive LDsoas we11 (>112.03

### yg a.i./bee). 

### 5.1.3 

### Terrestrial and Semi-aquatic Plants Terrestrial and semi-aquaticplants may be exposed to pesticides from runoff and spray drift. Semi-aquatic plants arethose that inhabit low-lying wet areas that may be dry at certain times of the year. EECs for terrestrial and semi-aquaticplants are derived for areas adjacent to the treatment site. Acute RQs for terrestrial plants are derived by dividing the EEC by the ECZ5 from Tier I1 seedling emergence and vegetative vigor toxicity tests. Acute RQs for listed plant species are calculated by dividing the EEC by the NOAEC (if not available, an ECo5 is used) value from Tier 

### I1 toxicity tests. Terrestrial plant EECs and toxicity endpoints are provided in 

### Tables 3.10 and 4.11, respectively. EECs and RQs for applications to non-crop areas and turf are calculated using TerrPlant v1.2.2 

### (Appendix 

### C) and RQs are summarized in 

### Table 

### 5.2.As expected because aminocyclopyrachlor is an herbicide, severalRQs exceededthe LOC. RQs ranged from 

### <O. 

### 1(no spray drift due to granular application)to for listed dicots arebased on an ECosbecause the NOAEC produced was ECoswas outside the range of concentrations tested; therefore, there is this estimated toxicity value.

concentrations. 5.2 

### Risk Description A screening-level (Level I) risk assessment, based onthe proposed uses of aminoc on non-crop areas and turf, suggeststhat levels of aminocyclopyrachlor in the env when compared with the most sensitive toxicity values for a given taxa, may resul adverse effects to terrestrial plants. These direct effectsmay also result in indirect target speciesthrough reduction of habitat or food sources. Due to lack of accept some taxa and lack of data for the degradates, not all potential risks are known. relationships (SARs), total toxic residue (TTR), and comparisons of environme concentrations relative to effects thresholds are methods used to reduce uncert degradate toxicities (see 

### Section 5.2.3). 5.2.1 

### Risks of Aminocyclopyrachlor to Aquatic Organisms I Acute and chronic risk quotients for all aquatic taxa were predicted to be below LOCs were available. However, in the absence of data, chronicrisks are assumed for listed species; these taxa include freshwater and estuarinelmarine chronic toxicity data for freshwater invertebrates has a high ecologicalrisk assessmentby reducing uncertainties, which methods or weights of evidence.Although it was determined that the ester does not have equivalent toxicityto the acid (see 

### Sections 2.2.3 and 2.6.2), the RQs that were calculated for the ester did not exceed any of the LOCs. Submissionof acute estuarinelmarineand aquaticplant toxicity data for the ester has a low potential to add value to this ecological risk assessment because this additional data would have to show about a three to four orders of magnitude increase in toxicity over the available acid data to cause LOC exceedances. 5.2.2 

### Risks of Aminocyclopyrachlor to Terrestrial Organisms Birds and Mammals Acute risk quotients for birds (and terrestrial amphibianslreptiles)would fall below LOCs due to lack of toxicity observed in submitted studies.However, in the avian acute oral study with the ester, reduction in male body weight was observed. This is a significant adverse sublethal effect that may result in changes in survival,growth, reproduction of wild birds. Chronic risks for birds cannot be precluded for non-listed and listed species due to lack of acceptable avian reproduction data. Submissionof chronic toxicity data for birds has a high potential to add value to this ecological risk assessment by reducing uncertainties,which cannot be done using alternate methods or weights of evidence.Acute and chronicrisk quotients for mammals fell below LOCs. From submitted studies, it was determined that the ester would have equivalent acute and chronic toxicityto birds and mammals as the acid. The currentlyproposed salt uses would not result in release of the salt to the environment; however, if different formulations for the salt areproposed in the futurethat would result in release of the salt to the environment, there may be potential for risks to birds and mammals. 

### In this case, salt toxicity data may be needed to adequately assess potential risks. 

### Terrestrial Plants Aminocyclopyrachlor is proposed for pre- and post-emergent control of broadleaf weeds and grasses. As such, it is expected that aminocyclopyrachlor would present potential risks to terrestrial and semi-aquaticplants. RQs exceeded LOCs for the highest use rates, including 

### a granular form. The submittedlabels include statements to reduce the potential for spray drift. 

### If futureuses are proposed for crop uses, it may be necessaryto require a vegetative buffer strip to reduce risks to non-target plants. Although the currentproposed uses are for non-crop areas and turf, a spray driftbuffer analysis was conducted to estimate the buffer distances required to reduce the potential for effects to nontarget terrestrial plants. AgDRIFT was used to model the dissipationdistance to the EC25 levels for non-listed terrestrialplants and to NOAEC levels for listed terrestrialplants. A drop size distributionof ASAE Very Fine to Fine was chosen to reflect the proposed label language (352- TI1was used as an example).Buffer distances were calculated for the most sensitiveendpoints for both monocots and dicots in the seedling emergence and vegetative vigor studies.For ground applications, only a Tier I assessment exists. 

### In the event that a Tier I1 aerial application resulted in an out-of-range estimation (>lo00 feet), the Tier I11 AgDRIFT model could be used to estimate distances up to 2640 feet.

### Non-listed Species Dissipationdistances ranged from 16.4 to >I000 feet for Tier I ground applications at e maximum proposed application rate (0.284 lb a.e./acre). At the lower rate (0.094 lb a.e. acre), 

# "; dissipationdistances ranged from 6.56 to >I000 feet for Tier I ground applications. For aerial applications (TI1or TIII), dissipationdistances ranged from 108.27to >2640 feet at rate (0.284 lb a.e./acre). The lower applicationrate is proposed for ground Dissipation distances can be found in 

### Table 5.3 for non-listed species. Listed Species Dissipation distances ranged from 19.68to >lo00 feet for Tier I ground applications at maximum proposed applicationrate (0.284 lb a.e./acre). At the lower rate (0.094 lb a.e. dissipationdistances ranged from 6.56 to >I000 feet for Tier I ground applications. applications (TI1or TIII), dissipationdistances ranged from 131.23 to >2640 feet at rate (0.284 1b a.e./acre). The lower applicationrate is proposed for ground Dissipationdistances can be found in 

### Table 5.4 for listed species. AgDRIFT does not address chronicconcerns and only functions to model single applic Because the proposed application rates for aminocyclopyrachlor vary based on the site and end-user,thehighest spray applicationrate was chosen (0.284lb a.e./acre areas) and the lowest spray application rate was chosen (0.094 lb a.e./acre for uses). Other higher turf application rates have been proposed,but these are granular formulations.It is important to note that AgDRIFT assumes 

### an entire acrehas which may not necessarily be true in the case of non-crop area and turf uses.Ground water used for irrigation purposes is another potential route of exposure for terrestrial plants due to aminocyclopyrachlor's abilityto leach to and accumulate in ground water. However, because the proposed uses are restricted to non-crop and turf areas, EFED did not estimate ground water EECs using SCI-GROW. 

### If uses are proposed for crop areas in the future, this would be a valuable risk characterization tool. 5.2.3 

### Potential Risks Due to Exposure to the Degradates No toxicity data on degradates have been submitted. Therefore, estimated toxicity values were generated using structure activity relationships (SARs)based on the ECOSAR program (version 1.00) for the purpose of identifying degradates that may need additional investigation. ECOSAR is a publically available1 computerized predictive system that estimates the aquatic toxicity of chemicals.The program estimates a chemical's acute (short-term) toxicity and chronic (long-term or delayed) toxicity to aquatic organisms such as fish, aquatic invertebrates, and aquaticplants by using SARs. Theresults of this modeling exercise suggest that two degradates, IN-LXT69 and IN-YY905, may be more toxic than the parent to daphnids on a chronicbasis 

### (Table5.5, see

### Appendix E for ECOSAR outputs).

http://www

### .epa.gov/op~tjnewchemsltoo1$/2 1 ecosar, htm
54Currently, there is no reliable SAR available that estimates the toxicity of pesticidesto birds. Therefore, the evaluation of degradates conducted by the Health Effects Division 

### (HE ) is generallyused to evaluate the potential toxicity of degradatesto mammals and birds.

# 4 Based on the analysis,IN-V0977 may be more toxic to birds and mammals than the parent chernipal. It forms via aqueous photolysis in quantities up to 

### 14.6%of parent. Potentialroutes of ex birds and mammals for this degradateis through drinking water (dew and puddles) and exposure. However, by comparing the concentrationsexpected in the environment to thresholds, IN-V0977 would have to be more than two orders of magnitude more parent compound to cause LOC exceedances.

Daphnid EC5O: 3 mgiL Algae Ec50: 10mg/L

Algae ChV: No SAR I I 

## i IN-Q3007 

# "I 24.4

Fish ChV: 

# ~ 5mgiL Daphnid ChV: 2.7 mg/L 

# i Algae ChV: 0.1 mg/L Aqueous Photolysis MRID 475602-11

IN-VO977 Fish LC50: 800 mg/L Daphnid EC5O: 200 mg/L 

# ~ AlgaeEc50: 0.8 mg/L

14.6 Aqueous Photolysis MRID 475602-1 1 Fish LC50: >100rngL Daphnid EC5O: >100mgiL Algae Ec50: >100mg/L Fish ChV: >lOOmg/L Daphnid ChV: >I00 mg/L Algae ChV: >100mg/L IThe total toxic residue (TTR) approach is used by EFED to evaluate potential risks to non-target organisms from aquatic exposure to degradates.TTRs represent potential combined exposuresto the parent chemical and its degradates. However, due to the stability of the parent aminocyclopyrachlor,TTR values are expected to be similarto the EECs presented in this assessment for the parent chemical alone. Degradation half-lives used in GENEEC to estimate EECs for the parent chemical were long 

### and essentially stable. Aqueous photolysis is the only degradation pathway input into GENEEC for which aminocyclopyrachlor degrades more rapidly (half-life =7.8 days). However, GENEECestimated EECs are not sensitive to aqueous photolysis inputs. To investigate how aqueous photolysis affected EECs, GENEEC was run with short (tin = 1.0 day) and long (tin = 0 day = stable) half-lives using the proposed maximum applicationrates for non-crop areas and turf. All other inputs were kept constant and were not changed from the inputs previouslypresented in 

### Table 3.6. Theresults for non-crop uses show the peak EEC for photolysis set at tll2 = 0 days (stable) was 16.86ppb and the peak EEC for photolysis set at tin 

### = 1 day was 16.84ppb. The results for turf show the peak EEC for photolysis set at tl,2 = 0 days (stable) was 16.82ppb and the peak EEC for photolysis set at tl,2 = 1 day was 16.82 ppb. Outputs (including the 21-day and 60-day EECs) are located in 

### Appendix 

### F. These results demonstrate that varying the aqueous photolysis input parameter has minimal effect on aquatic exposure values and potential risks. Because aqueous photolysis is the only significant rapid degradation pathway of aminocyclopyrachlor, this conservativeTTR approach shows that aquatic exposure to the degradateswould not result in any additionalpotential risks over those presented from exposure to the parent compoundunless the degradates were a few to several orders of magnitude more toxic than the parent; submissionof both aquatic and terrestrial toxicity data for the three degradates of concern, as predicted by SARs,has a low potential to add value to this ecological risk assessment.

### 5.3 

### Threatenedand EndangeredSpecies Concern I To determine whether the proposed use sites for a pesticide are geographically associat~d with known locations of listed species, a screening-level search of the LOCATES (version 2110.3) database is conducted. The database compared county-level location data for listed spe county-level crop production data (as available in the 2002 agricultural census) to coarse overlaps of listed species with the proposed labeled uses of species arethose that are currently on the Federal list of plants. Becauseproposed uses of aminocyclopyrachlordo not confine its use aminocyclopyrachlormay be used all over the United States. According to the and indirect effects in 

### Table 5.4, every federally listed species may be uses of aminocyclopyrachlor. Therefore, a LOCATES analysis was

I 

### 5.3.1 

### Action Area I For listed species assessment purposes, the action area is considered to be the area directly or indirectly by the Federal action and not merely the immediate area action. At the initial screening-level, the risk assessment considers broadly groups and so conservatively assumes that listed species within those broad located with the pesticide treatment area. This means that terrestrialplants assumed to be located on or adjacent to the treated site and aquatic located 

### in a surface water body adjacent to the treated site. The listed species are located within 

### an assumed area, which has exposureto the pesticide, and that exposures are likely to treatment area. This risk assessment presents the use of initial co-locationof species with treatment areas. If the assumptions associatedwith the screening-level action area result in RQs that ar the listed species LOCs, a "no effect" determination conclusionis made with respect species in that taxa, and no further refinement of the action area is necessary. Furth below the listed speciesLOCs for a given taxonomic group indicateno concernfor indi effects upon listed speciesthat depend upon the taxonomic group covered by the RQ as resource. However, in situations where the screening assumptions lead to RQs in e listed speciesLOCs for a given taxonomic group, a potential for a "may affect" co and may be associatedwith direct effects on listed species belonging to that taxon may extend to indirect effects upon listed species that depend upon that taxonomi resource. In such cases, additional information on the biology of listed species, these species, and the locations of use sites couldbe considered to determine th screening assumptions regarding an action area apply to a particular listed org subsequent refinement steps could consider how this informationwould impa for a particular listed organism and may potentially include areas of exposure and downstream of the pesticide use site. 

## 1 1

### 5.3.2 

### Taxonomic Groups Potentially at Risk: Direct Effects Based on available screening level information, for the proposed uses of aminocyclopyrachlor, there is a potential for direct effects to listed terrestrial plants. Due to lack of acceptable data for the acid, direct effects are assumed for birds (chronic) and freshwater invertebrates (chronic). Consequently, direct effects must be assumed for estuarinelmarineinvertebrates (chronic); however, receipt of a chronic freshwater invertebrate study could eliminate this assumption. There is a potential concern for indirect effects upon the listed organismsby, for example, perturbing habitat, forage or prey availability. 

### In conducting a screen for indirect effects, direct effect LOCs for each taxonomic group are used to make inferences concerning the potential for indirect effects upon listed species that rely upon non-endangered organisms in these taxonomic groups as resources critical to their life cycle. A summary of the risk conclusions and direct and indirect effects determinations is presented in 

### Table 

### 5.6. Because the proposed uses of aminocyclopyrachlor cannot be geographically limited, all federally listed species may be either directly or indirectly affected.

The LOCATES database (version 2.9.7) identifies those U.S. counties that include non-crop and turf areas and that have federally-listed endangered or threatened species that may be directly or indirectly affected.The list of affected species derived from LOCATES was not included in.this assessment because the uses cover most of the United States and the direct and indirect effects includes most species. With additional refinementby exploring more detailed use patterns andspecies biology (e.g., geographic location, specific feeding habits, time of year llkely toutilize crop fields), some species listed may be determinedto be not likely to be affected. 

### 5.3.3 Use of Probit Slope Response Relationship to Provide Information on the Endangered Species Levels of Concern I The Individual Effect Chance Model (Version 1. I), developed by the Environmentall?aJye and Effects Division, is used by the Agency to calculate the chance or probability of an indikidual mortality (effect) correspondingto the listed species' acute LOCs and calculatedRQs. he model, which is an Excel spreadsheet tool, allows for calculationsby entering the mean slope estimate (and the 

### 95% confidence bounds of that estimate) as the slope parameter for th temporal nature of the exposure to make an effect determination. 

# 1
spreadsheet.The generated information serves as a guide to establish the need for and of additional analysis that may be performed as well as evaluations of the Because screening-level acute LOCs were calculated and exceeded for only terrestrial aquaticplants in this assessment,probit analysis was not conducted. The endpoints plant studies include emergence, survival, shoot height, and dry weight rather than sing1 mortality events. 

### 5.3.4 Indirect Effects Analysis The Agency acknowledges that pesticides have the potential to exert indirect effectsupon the listed organisms by, for example, perturbingforage or prey availability,altering the ext nt of nesting habitat, etc. 

### In conducting a screen for indirect effects, direct effect LOCs for ea 

# 1

h taxonomic group are used to make inferences concerning the potential for indirect effect upon listed species that rely upon non-endangered organisms in these taxonomic groups as re ources critical to their life cycle. 

# !

I Based on direct risk to terrestrial plants, there may be potential indirect effects to aquati4 and terrestrial species that depend on these organisms (includingtheir surrogates) as a sourc@ of food or habitat, including riparian habitats. Terrestrialplants serve several important habitat-r lated functions for listed species. 

### In additionto providing habitat and cover, terrestrial vegeta ion also provides shelter for and cover from predators while foraging. Terrestrialplants also pro ide energy to the terrestrial ecosystem through primary production.Upland vegetation inclu ing grassland and woodlands provides cover during dispersal. Riparian vegetationhelps to aintain the integrity of aquatic systemsby providing bank and thermal stability, serving as a buf er to filter out sediment, nutrients, and contaminants before they reach the watershed, and ser ing as an energy source. 

# 1

6 

### Description of Assumptions, Uncertainties, Strengths,and Limit

# a tions 6.1 

### Assumptions and Limitations Related to Exposure for all Taxa I There are a .numberof areas of uncertainty in the aquatic and te~estrial risk assessments.)The toxicity assessment for terrestrial and aquatic animals is limitedby the number of specied tested in the available toxicity studies. Use of toxicity data on representative species does not drovideinformation on the potential variability in susceptibility to acute and chronic exposures. This screening-level risk assessment relies on labeled statements of the maximum rate of aminocyclopyrachlor application, the maximum number of applications,and the shortest interval between applications. Together, these assumptions constitute a maximum use scenario. The frequency at which actual uses approach these maximums is dependant on resistance to the herbicide, timing of applications,and market forces. 

### 6.2 

### Assumptions and Limitations Related to Exposurefor Terrestrial Species Variation in habitat anddietary requirements For screening terrestrial risk assessments, a genericbird or mammal is assumed to occupy either the treated field or adjacent areas receiving pesticide at a rate commensurate with the treatment rate on the field. The habitat and feedingrequirements of the modeled species and the wildlife species may be different.It is assumed that species occupy, exclusivelyand permanently, the treated area being modeled. This assumption leads to a maximum level of exposurein the risk assessment. The acute studies have a fixed exposureperiod, not allowing for the differences in response of individuals to different durations of exposure. Further, for the acute oral study, aminocyclopyrachlor is administered in a single dose which does not mimic wild birds' exposure through multiple feeding. Also, it does not account for the effect of different environmental matrices on the absorption rate of the chemical into the animal. Because exposureoccurs over several days, both the accumulated dose and eliminationof the chemical from the body for the duration of the exposure determine the exact exposure to wildlife, however they are not taken into account in the screening assessment. There was also no assumption of an effect of repeated doses that changethe tolerance of an individual to successive doses. Variation in diet composition The risk assessment and calculated RQs assume 

### 100%of the diet is relegated to single food types foraged only from treated fields. The assumption of 100%diet from a single food type may be realistic for acute exposures,but diets are llkelyto be more variable over longer periods of time. This assumptionis likely to be conservativeand will tend to overestimate potentialrisks for chronic exposure, especiallyfor larger organisms that have larger home ranges. These large animals (e.g., deer and geese) will tend to forage from a variety of areas and move on and off of treated fields. Small animals (e.g., mice, voles, and small birds) may have home ranges smaller than the size of a treated field and will have little or no opportunity to obtain foodstuffs that have not been treated with aminocyclopyrachlor. Even if their home range does cover area outside the treated field, aminocyclopyrachlor may have runoff to areas adjacent to the treated field. Exposure routes other than dietary Only dietary and incidental ingestionof contaminated soils exposureis included in the exposure assessment. Other exposureroutes are possible for animals in treated areas. These routes include ingestion of contaminateddrinking water, dermal contact, inhalation, and preening. Becauseaminocyclopyrachlor does not volatilize appreciably, inhalation does not appear to be a significant contributor to the overall exposure. Given that aminocyclopyrachlor is solubile in water there exists the potential to dissolvein runoff and puddles on the treated field ma$ contain the chemical. If toxicity is expected through any of these other routes of exposure, then the risks of a toxic response to aminocyclopyrachlor is underestimated in this risk assessment. 

## ~ Dietary Intake - 

### The Differences Between Laboratory and Field Conditions 

## i I There are several aspects of the dietarytest that introduce uncertainty into calculation

# 04 the LCro value (Mineau, et al., 1994;ECOFRAM, 1999). The endpoint of this test is reported asithe concentration mixed with food that produces a response rather than as the dose ingested1 Although food consumption sometimes allows for the estimate of a dose, calculations of the mglkglday are confoundedby undocumented over the durationof the test. Usually, if the end of the five-day exposureperiod. allows for a measure of the average consumptionper day for a group; be further confounded if birds die within a treatment group. The birds also complicates the estimateof the dose; controls often durationof the test. Sinceweights are only taken at the the end, the doseper body weight (mglkg) is difficult to interpretation of this test is also confounded because the of the intrinsic toxicity of the pesticide, but also the food. Further, the acute and chronic characterization of risk rely on comparisons of wildlife di tary residues with LCsoor NOAEC values expressed in concentrations of pesticides in labor tory feed. These comparisons assume that ingestion of food items in the field occurs at rates commensuratewith those in the laboratory. Although the screening assessment process adjusts dry-weight estimates of food intake to reflect the increased mass in fresh-weight wildlif food intake estimates, it does not allow for gross energy and assimilative efficiency differenc s 

# I

between wildlife food items and laboratory feed. On gross energy content alone, direct comparison of a laboratory dietary concentration-based effects threshold to a fresh-wei pesticide residue estimatewould result 

### in an underestimation of field exposure by food consumptionby a factor of 1.25 - 2.5 for most food items. Only for seeds would the comparison of dietarythreshold to residue estimate lead to an overestimate of Differences in assimilative efficiencybetween laboratory and wild diets suggestthat c screening assessment methods do not accountfor a potentially important aspect of food requirements. Depending upon species and dietary matrix, bird assimilation of wild ranges from 

### 23 - 80%, and mammal's assimilation ranges from 41 - 85% 

### (U.S. Protection Agency, 1993). If it is assumed that laboratory chow is formulated assimilative efficiency (e.g., a value of 85%), a potential for underestimation existby assuming that consumptionof food in the wild is comparable with laboratory testing. 

### In the screening process, exposure may be rates arenot related to food consumption.Finally, the screening procedure does not account for situations where the feeding rate may be above or below requirementsto meet free living metabolic requirements. Gorging behavior is a possibility under some specific wildlife scenarios (e.g., bird migration) where the food intake rate may be greatly increased. Kirkwood (1983) has suggested that an upper-bound limit to this behavior might be the typical intake rate multiplied by a factor of 

### 5. In contrast is the potential for avoidance, operationally defined as animals responding to the presence of noxious chemicals in their food by reducing consumption of treated dietary elements. This response is seen in nature where herbivores avoid plant secondary compounds. In the absence of additional mformation, the acute oral LD50 test provides the best estimate of acute effects for chemicals where exposure can be consideredto occur over relatively short feeding periods, such as the diurnal feeding peaks common to avian species (ECOFRAM, 1999). Incidental Pesticide Releases Associated with Use This risk assessment is based on the assumption that the entire treatment area is subject to aminocyclopyrachlor application at the rates specified on the label. 

### In reality, there is the potential for uneven applicationof aminocyclopyrachlor through such plausible incidents as changes in calibration of application equipment, spillage, and localized releases at specific areas of the treated field that are associated with specifics of the type of application equipment used (e.g., increased application at turnabouts when using older application equipment). 6.3 

### Assumptions and Limitations Related to Exposure for Aquatic Species The fate and transport database for aminocyclopyrachlorwas sufficient to conduct aquatic modeling for exposure assessment of aquatic species. The GENEEC model was used to produce estimated exposure concentrations. Because no RQs exceeded LOCs for aquatic species, these exposure estimates did not need to be refined by using PRZMIEXAMS. Because aminocyclopyrachloris a new chemical, no monitoring data were available to compare to the model estimates. 6.4 

### Assumptions and Limitations Related to Effects Assessment As described in 

### Sections 2.2.3 and 2.6.2, the lack of acceptable data for the acid, ester, and certain degradates results in effects uncertaintiesfor the respective taxa. However, for many taxa, alternate methods and additional weights of evidence could be used to describe potential risks. For taxa, such as freshwater and estuarinelmarineinvertebrates (chronic) and birds (chronic), where alternate approaches could not be used in the absence of data, risks cannot be precluded for non-listed and listed species. Age class and sensitivity of eflects thresholds It is generally recognized that test organism age may have a significant impact on the observed sensitivityto a toxicant. The screening risk assessment acute toxicity data for fish are collected on juvenile fish between 0.1 and 

### 5 grams. Aquatic invertebrate acute testing is performed on recommended immature age classes (e.g., first instar for daphnids, second instar for amphipods, stoneflies and mayflies, and third instar for midges). Similarly, acute dietary testing with birds isalso performed onjuveniles, with mallard being 

### 5-10 days old and quail 

### 10-14days oldi.

I Testing ofjuveniles may overestimate toxicity of older age classes for pesticide active I ingredients, such as aminocyclopyrachlor, that act directly (without metabolictransfor because younger age classes may not have the enzymatic systems associatedwith xenobiotics. The screening risk assessment has no current provisions for a method that accounts for this uncertainty. In so far as the available toxicity ranges of sensitivity 

### information with respect to age class, the risk sensitive life-stage information as the conservative screening endpoint. 

### Use of theMost Sensitive Species Tested , Although the screening risk assessmentrelies on a selected toxicity endpoint from the ost sensitive species tested, it does not necessarilymean that the selected toxicity endpoint 

# ?

eflect sensitivityof the most sensitive species existing in a given environment. The relativepa/sition of the most sensitive species tested in the distributionof all possible species is a function o the overall variability among speciesto a particular chemical. In the case of listed species, here is uncertainty regarding the relationship of the listed species' sensitivity and the most sens tive species tested. 

# 1 i
The Agency is not limited to a base set of surrogate toxicity informationin establishing isk assessment conclusions. The Agency also considers toxicity data on non-standard test s ecies when available. 

# 4
I

### 7 

### Literature Cited
Beyer, W. N., E. E. Connor and S. Gerould. 1994.Estimates of Soil Ingestion by Wildlife. Journal of WildlifeManagement. 58(2):375-382. Bhatti, M.A., 

### K. Al- Khatib, A.S. Felsot, R. Parker and S. Kadir. 1995. Effects of Simulated Chlorsulfuron Drift on Fruit Yield and Quality of Sweet Cherries (Prunus Avium 

### L.). Environ. Tox. Chem. Vol 14No. 3, pp. 537-544. Briggs GG, Bromilow RH, Evans AA (1982) Relationships between lipophilicityand root uptake and translocationof non-ionised chemicals by barley. Pestic Sci 13: 495-504. ECOFRAM. 1999. ECOFRAM TerrestrialDraft Report. Ecological Committee on FIFRA Risk Assessment Methods.U.S. EPA, Washington D.C.
Fahl GM, Kt-eftL, Altenburger R, Faust 

### M, Boedeker W, Grirnrne LH (1995) pH-dependent sorption, bioconcentrationand algal toxicity of sulfonwea herbicides. Aquat Toxicol 3 1: 175-187. Fletcher, J.S. 1991. Horse Heaven HillsIBadger Canyon, A case Study of Alleged PesticideDrift Damage. Presentation at the 84thAnnual Meeting & Exhibition, Vancouver, British Columbia 91-150.7 Fletcher J.S., T. G. Pfleeger and H.C. Ratsch 1993. Potential Environmental Risks Associated with the New Sulfonylwea Herbicides. Environ. Sci. Technol. Vol27, No 10, pp. 2250- 2252. Fletcher, J.S., J.E. Nellesson, and T. 

### G. Pfleeger. 1994. Literaturereview and evaluationof the EPA food-chain (Kenaga) nomogram, an instrumentfor estimating pesticideresidues on plants. Environ Toxicol Chem 13(9):1383-1391.
Fletcher J.S., T. G. Pfleeger and H.C. Ratsch 1995. Chlorsulfuron Influence on Garden Pea Reproduction. Physiologia Plantarum 94: pp 261-267. Fletcher J.S., T. G. Pfleeger, H.C. Ratsch and R. Hayes 1996. Potential Impacts of Low Levels of Chlorsulfuron and Other Herbicides on Growth 

### and Yields of Non-target Plants. Environ, Tox. and Chem. Vol. 15,No. 7. pp 1189-1196. Food and Agriculture Organizationof the United Nations. FA0PESTICIDE DISPOSAL SERIES 8. Assessing Soil Contamination: A Reference Manual. Appendix 2. Parameters of pesticides that influence processes in the soil. Editorial Group, FA0 Information Division: Rome, 2000. http://www.fao.or~/DOCREP/003/X2570E/XmGusey W.F., Z.D. Maturgo. 1973. Wildlife Utilization of Croplands. Environmental I ConservationDepartment. Shell Oil Company, Houston, TX. Hoerger, 

### F. and E.E. Kenaga. 1972. Pesticideresidues on plants: correlation of represe tative data as a basis for estimationof their magnitude in the environment. In F. Couls on and 

### F. Korte, eds., Environmental Quality and Safety: Chemistry, Toxicology, and Tec nology, Georg Thieme Publ, Stuttgart,West Germany, pp. 9-28. 

# \

~ HSDB, 2002 [Hazardous Substances Data Bank]. National Library of Medicine. Last u4date: 6- 8-2002. Access date: 6-5-2003. 

### http://toxnet.nlm.nih.gov/cgibin~sismtmlgen?HS~DB. Kirkwood, J. 1983. A limit to metabolizable energy intake in mammals and birds. cobp. Biochem. Physiol. 75A: 1-3. I Martin, C. M., 

### H. S.Zim & A. C. Nelson, 1951. American Wildlife and Plants - A ~uid(e to WildlifeFood Habits, Dover Publ. Inc., New York. 

# ~ Merritt, R. W. and 

### K. W. Cumrnins, eds. 1984.An Introduction to the Aquatic Insects o North 

# F America 2nd ed. KendalmuntPublishingCompany, Dubuque, Idaho. 722 pp. 

# ~ Mineau, P., B. Jobin and A. Baril. 1994. A critique of the avian 5-day dietarytest (LC basis of avian risk assessment. Technical Report No. 215, Headquarters, Wildlife Service,Hull, Quebec.p. 23. NatureServe. 2005. NatureServe Explorer: 

### An online encyclopedia of life [web applicat/on]. Version 4.5. NatureServe, Arlington, Virginia. Available 

### http:l/~~~.natureserve.orglexplorer. Schwarzenbach,R.P., Gschwend, P. M., and Imboden, D.M., 1993. Environmental 0rdanic Chemistry. John Wiley and Sons, Inc. New York. SyracuseResearch Corporation. 2006. SurfaceWater Scenario Development for the P Root Zone Model (PRZM) for Modeling Pesticide Exposure in Outdoor Supplement to Metadata. GSA Contract No. GS-00F-0019L,Report 08 1,North Syracuse, 

### NY. Tomlin CDS (ed) (2000) The PesticideManual, 12~ Edition. British Crop Protection ~duncil, UK. I Uesugi Y, Ueji M, Koshioka M (ed) (1997) Pesticide Data Book, 3rd Edition. Soft ~cienbe Publications,Tokyo, Japan. 1 Urban D.J. and N.J. Cook. 1986. Hazard EvaluationDivision Standard Evaluation Proqedure Ecological Risk Assessment. EPA 54019-85-001. U.S. Environmental Protectiob Agency, Office of Pesticide Programs, Washington, DC.USDA Crop Profiles.

### http://www.ipmcenters.or~cropprofiles/CP form.cfm U.S. EPA 1993. Wildlife ExposureFactors Handbook. Volume 

### I of 11. EPN600lR-931187a. Office of Research and Development,Washington, D. C. 20460.EPN600lR-931187a. U.S. EPA 1998. Guidance for Ecological Risk Assessment. Risk Assessment Forum. EPN630lR-95/002F, April 1998. U.S. EPA 2002. Guidance for SelectingInput Parameters in Modeling the Environmental Fate and Transport of Pesticides Input Parameter Guidance. Version I1 February 28,2002. U.S. Environmental ProtectionAgency, Office of Pesticide Programs, Environmental Fate and Effects Division. U.S. EPA 2004. Overview of the Ecological Risk Assessment Process in the Office of Pesticide Programs. Office of Prevention, Pesticides, and Toxic Substances. Office of Pesticide Programs. Washington, D.C. January 23,2004. Wolfe, 

### N.L., M.E-S. Metwally and A.E. Moftah. 1989. HydrolyticTransformations of Organic Chemicals in the Environment. 

### In: Reactions and Movement of Organic Chemicals in Soils. B.L. Sawhneyand 

### K. Brown, (Eds), Soil Science of America and American Societyof Agronomy, Madison,WI. P.229-242. Wolfe, N.L. 1990. Abiotic Transformations of Toxic Organic Chemicals in the Liquid Phase and Sediments. 

### In: Toxic Organic Chemicals in Porous Media. 

### Z. Gerstl, Y. Chen, U. Mingelgrin and B. Yaron. (Eds.). Springer-Verlag,New York. p. 136- 147.

### Appendix A. 

### GENEEC Output Parent: Non-crop aerial (spray) I

RUN No. 1 FOR ACP Acid ON Non-Crop * INPUT VALUES *

# ~

................................................................... 

### t

RATE (#/Ac) NO .APPS & SOIL SOLUBIL APPL TYPE NO-SPRAY INCDR~

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

................................................................... 

## t

FIELD AND STANDARD POND HALFLIFE VALUES (DAYS)

................................................................... lMETABOLIC DAYS UNTIL HYDROLYSIS PHOTOLYSIS METABOLIC COMBINE~I (FIELD) RAIN/RUNOFF (POND) (POND-EFF) ( POND) (POND) 1 I
...................................................................

373.00 2 N/ A 7.80- 967.20 .OO 967.201

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

................................................................... t PEAK MAX 4 DAY MAX 21 DAY MAX 60 DAY MAX 90 DAY 

# ~ GEEC AVG GEEC AVG GEEC AVG GEEC AVG GEEC
-------------------------------------------------------------------& 16.86 16.85 16.79 16.64 16.53 Non-crop ground (spray)
RUN No. 1 FOR ACP Acid ON Non-Crop * INPUT VALUES *

................................................................... t

RATE (#/Ac) NO .APPS & SOIL SOLUBIL APPL TYPE NO-SPRAY INCOR~

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

................................................................... I .284( .284) 1 1 12.0 2810.0 GRHIFI( 6.6) -0 -0 I

FIELD AND STANDARD POND HALFLIFE VALUES (DAYS)

.................................................................... I METABOLIC DAYS UNTIL HYDROLYSIS PHOTOLYSIS METABOLIC COMBINEq (FIELD) RAIN/RUNOFF (POND) ( POND-EFF) ( POND) (POND)

................................................................... 4

373.00 2 N/ A 7.80- 967.20 -00 967.20

# ~

GENERIC EECs (IN MICROGRAMS/LITER (PPB)) Version 2.0 Aug 1, 2004

................................................................... i PEAK MAX 4 DAY MAX 21 DAY MAX 60 DAY MAX 90 DAY 

# ~ GEEC AVG GEEC AVG GEEC AVG GEEC AVG GEEC 

### 1
______-_____-______-------------------------------------------------l 16,47 16.46 16.40 16.26 16.15

### Turf ground (granule)
RUN No. 1 FOR ACP Acid ON Turf * INPUT VALUES *

....................................................................

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

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

.................................................................... .108( .307) 3 30 12.0 2810.0 GRANUL( .O) .O .O

FIELD AND STANDARD POND HALFLIFE VALUES (DAYS)

.................................................................... METABOLIC DAYS UNTIL HYDROLYSIS PHOTOLYSIS METABOLIC COMBINED (FIELD) RAIN/RUNOFF (POND) (POND-EFF) ( POND) ( POND)

....................................................................

373.00 2 N/ A 7.80- 967.20 .OO 967.20

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

.................................................................... PEAK MAX 4 DAY MAX 21 DAY MAX 60 DAY MAX 90 DAY GEEC AVG GEEC AVG GEEC AVG GEEC AVG GEEC

### Appendix 

### B. T-REX Output Summary of Risk Quotient Calculations Based on Upper Bound Kenaga EECs 1application at 

### 0.284 lb a.e./acre

Sizeclass not used for dietary risk quotients

Sizeclass not used for dietary risk quotients

### Appendix 

### C. TerrPlant Output 1 application at 0.108 lb a.e./acre (ground - granule)



### 1application at 0.094 lb a.e./acre (ground - spray) Runoff to semi-aquatic areas Spray drift Total for dry areas Total for semi-aquatic areas

1application at 0.284 lb a.e./acre (ground - spray) (M)*R*10 A*D ((M)*R)+(A*D) ((A/I)*R*1 O)+(A*D)

Runoff to semi-aquaticareas Spray drift Total for dry areas Total for semi-aquaticareas 0.054 0 0.0054 0.054

(M) *R* 10 A*D ((M>*R)+(A*D> ((M)*R*10)+(A*D)



### Table 

### C-5. 

### EECs for Aminocycbpyrachlor 0.047 0.00094 0.00564 0.04794

Description Equation EEC1application at 

### 0.284 lb a.e./acre (aerial - spray) 0.0142 0.142 0.00284 0.01704 0.14484 Runoff to dry areas Runoff to semi-aquatic areas Spray drift Total for dry areas Total for semi-aquatic areas

Monocot Monocot

Dicot Dicot (M)*R (Ah)*R*10 A*D ((M)*R)+(A*D) ((M) *R*10)+(A"D)

*If RQ > 1.0, the LOC is exceeded, resulting in potential for risk to that plant group. non-listed

listed non-listed

listed

Runoff to semi-aquatic areas Spray drift Total for dry areas Total for semi-aquatic areas 0.36 0.43 32.15 34.78

(M)*R*10 A*D ((MI *RR)+(A*D) ((M)*R*1 O)+(A*D) 0.142 0.0142 0.0284 0.1562 3.02 3.68 273.28 295.59 0.49 1.01 37.87 3641.03

### Appendix D. 

### RQ Methods and 

### LOC Definitions

Acute Risk EEC/LCSO or LD50/sqft or LDSO/day Acute Restricted Use EEC/LCSO or LDSO/sqft or LD5dday(or LD50< 50
Acute Listed Species EEC/LCSo or LDS0/sqft or LD50/day ChronicRisk EECINOAEC

Acute Risk EEC/LCSO or LD50/sqft or LDSO/day Acute Restricted Use
Acute Listed Species EEC/LCSO or LDSO/sqft or LDSO/day Chronic Risk EECINOAEC

Acute Risk EEC/LCSO or ECSo Acute Restricted Use EEC/LCSo or ECSo Acute Listed Species EEC/LCSo or ECS0 ChronicRisk EECINOAEC Terrestrial and Semi-Aquatic Plants Acute Risk EEC/EC25 Acute Listed Species EEC/ECo5 or NOAEC

Acute Risk EEC/ECSo The Risk Quotient Method is the means by which the Environmental Fate and Effects qivision (EFED) integrates the results of exposure and ecotoxicitydata. 

### In this method, both acu:e chronicrisk quotients (RQs) are calculated by dividing exposure estimates by the most ecotoxicityvalues derived from the studies.Calculated RQs are then compared to OPP's concern (LOCs). The LOCs are the criteriaused by OPP to indicate potential risk to organisms and the need to consider regulatory action.EFED has defined LOCs for acute potential restricted use, and for listed species. Risk presumptions, along with the corresr RQs and LOCs are summarized in the tablebelow. and sensitive

levels of nor.-target risk, onding

### Appendix E. ECOSAR Outputs

SMILES :cl(C2CC2)ncc(CL)c(N)nl CHEM : CAS Nurn: ChemID1: ChemID2: ChemID3: MOL FOR: C7 H8 CLl N3 MOLWT : 169.61 Log Kow: 1.O1 (KowWin estimate) Melt Pt: Wat Sol: 8453 mg/L (WskowWin estimate) ECOSAR v1.OO Class(es)Found

.............................. Aniline~ (Aromatic Amines) Predicted ECOSAR Class Organism Duration Anilines (Aromatic Amines) :Fish 96-hr Anilines (Aromatic Amines) :Fish 14-day Anilines (Aromatic Amines) :Daphnid 48-hr Anilines (Aromatic Amines) :Green Algae 96-hr Anilines (Aromatic Amines) :Fish Anilines (Aromatic Amines) :Daphnid Anilines (Aromatic Amines) :Green Algae End Pt m& (ppm) -------- 

### ------ ----------

LC50 80.220 LC50 212.499 LC50 2.527 EC50 9.897 ChV 0.376 ChV 0.052 ChV 6.529

-------- ------ ---------- Neutral OrganicSAR : Fish 96-hr LC50 897.019 (Baseline Toxicity) : Daphnid 48-hr LC50 459.298 Green Algae 96-hr EC50 131.980 Fish ChV 87.035 Daphnid ChV 35.617 Green Algae ChV 39.875 Note: * = asterisk designates: Chemical may not be soluble enough to measure this predicted effect. Anilines (Aromatic Amines):

For Fish Acute ToxicityValues: 2,3,5,6-Tetrachloroaniline is 19 times more toxic than predictedby this SAR. Tetrabromoaniline may be more toxic thanpredicted by this SAR as well. For Daphnid and Green Algae ToxicityValues: Tetrachloro- and tetrabromanilinemay be 20 times toxic thanpredicted by this SAR. N-Substituted anilines are less toxic than predicted by these SARs; for these compounds, Neutral Organic SARs are used. ECOSAR v1.00 SAR Limitations: Maximum LogKow: >7.8 (Fish 96-hrLC50, Daphnid 48-h LC50) Maximum LogKow: >3.7 (Fish 14-dayLC50) Maximum LogKow: >4 (Green Algae 96-hr EC50 and ChV) Maximum LogKow: >4.3 (Fish ChV) Maximum LogKow: >2.4 (Daphnid ChV) Maximum Mol Wt: 1000 Baseline Toxicity SAR Limitations: Maximum LogKow: 5.0 (Fish 96-hrLC50; Daphnid LC50) Maximum LogKow: 6.4 (Green AlgaeEC50) Maximum LogKow: 8.0 (ChV)Maximum MolWt: 1000

### Degradate: 

### IN-QFH57

SMILES :c 1 (C2CC2)nc(C(#N))c(C(=O)O)nl CHEM : CAS Num: ChemID1: ChemID2: ChemID3: MOL FOR: C8 H7 N3 02 MOLWT : 177.16 Log Kow: 0.83 (KowWm estimate) Melt Pt: Wat Sol: 6030 mglL (WskowWm estimate) ECOSAR v1.00 Class(es)Found Imidazoles-acid Predicted ECOSAR Class Organism Duration End Pt mgll (ppm) -------- ---------- ------ --zAcid moeity found:Predicted values multiplied by 10 Imidazoles-acid :Fish 96-hr LC50 1135.075 Imidazoles-acid :Daphnid 48-hr LC50 13.191 Imidazoles-acid :Fish ChV 101.028 ! Imidazoles-acid : Daphnid ChV 0.912 !

------ -------- Neutral OrganicSAR Fish 96-hr LC50 1332.358 (Baseline Toxicity) Daphnid 48-hr LC50 667.463 : Green Algae 96-hr EC50 178.090 : Fish ChV 129.792 : Daphnid ChV 50.132 : Green Algae ChV 52.060 Note: * = asterisk designates:Chemical may not be soluble enough to measure this predictedeffect. Note: ! = exclamation designates: The toxicityvalue was determined from

a predicted SAR using established acute-to-chronicratios and ECOSAR regression techniques which are documented in the supporting Technical Reference Manual. When possible, this toxicity value shouldbe considered in a weight of evidenceapproach. Imidazoles:

For Fish and Daphnid Acute Toxicity Values: If the log Kow of the chemical is greater than 5.0,or if the compound is solid and the LC50 exceeds the water solubility by lox,no effects at saturation arepredicted for these endpoints. For Green Algae Acute Toxicity Values: If the log Kow of the chemical is greaterthan 6.4, or if the compound is solid and the EC50 exceeds the water solubility by lox,no effects at saturationare predicted for these endpoints. For All ChronicToxicity Values:If the log Kow of the chemical is greater than 8.0, or ifthe compound is solid and the ChV exceeds the water solubility by 10X,no effects at saturation arepredicted for these endpoints. ECOSAR v1.OO SARLimitations:

--..------------------------ Maximum LogKow: 5.0 (LC50) Maximum LogKow: 6.4 (EC50) Maximum LogKow: 8.0 (ChV) Maximum Mol Wt: 1000 BaselineToxicity SAR Limitations:---------------.----------------- Maximum LogKow: 5.0 (Fish 96-hrLC50; Daphnid LC50) Maximum LogKow: 6.4 (Green Algae EC50) Maximum LogKow: 8.0 (ChV) Maximum Mol Wt: 1000SMILES :ClCClC(=O)N CHEM : CAS Num: ChemID1: ChemID2: ChemJD3: MOL FOR: C4 H7 N101 MOLWT : 85.11 Log Kow: -0.37 (KowWin estimate) Melt Pt: Wat Sol: 2.623E+005 mg/L (WskowWin estimate) ECOSARv1.00 Class(es)Found

-------------....------------- Amides ECOSAR Class Organism

........................... Amides :Fish Amides :Daphnid Amides :Green Algae Amides :Fish Amides :Daphnid Amides :Green Algae Predicted Duration End Pt mg/L (ppm) -------- ------
---7- 96-hr LC50 814.468 48-hr LC50 202.630 96-hr EC50 0.853 ChV 4.815 ChV 2.673 ! ChV 0.142

------ --------- Neutral Organic SAR:Fish 96-hr LC50 6585.711 (Baseline Toxicity) :Daphnid 48-hr LC50 2854.948 :Green Algae 96-hr EC50 466.243 :Fish ChV 658.740 :Daphnid ChV 173.542 :Green Algae ChV 109.548 Note: * = asterisk designates:Chemical may not be soluble enough to measure this predicted effect. Note: ! =exclamation designates:The toxicity value was determined from

a predicted SAR using established acute-to-chronic ratios and ECOSAR regression techniques which are documentedin the supporting Technical Reference Manual. When possible, this toxicity value shouldbe considered in a weight of evidenceapproach. Amides : ------- No limitations known at this time. ECOSARv1.00 SAR Limitations: Maximum LogKow: >8.5 (LC50) Maximum LogKow: >8.0 (EC50,ChV) Maximum Mol Wt: 1000 Baseline Toxicity SAR Limitations: Maximum LogKow: 5.0 (Fish 96-hrLC50; Daphnid LC50) Maximum LogKow: 6.4(Green Algae EC50) Maximum LogKow: 8.0 (ChV) Maximum Mol Wt: 1000SMILES :ClCClC(=O)O CHEM : CAS Num: ChemID1: ChemID2: ChemID3: MOL FOR: C4 H6 02 MOLWT : 86.09 Log Kow: 0.88 (KowWinestimate) Melt Pt: Wat Sol: 9.145E+004 mg/L (WskowWin estimate) ECOSAR v1 .OO Class(es) Found Neutral Organics-acid Predicted ECOSAR Class Organism Duration End Pt mg/L (ppm) 

### -------- ---------- -----dm---------- ------ -->Acid moeity found: Predictedvalues multiplied by 10 Neutral Organics-acid Neutral Organics-acid Neutral Organics-acid Neutral Organics-acid Neutral Organics-acid Neutral Organics-acid Neutral Organics-acid Neutral Organics-acid Neutral Organics-acid Neutral Organics-acid Neutral Organics-acid Neutral Organics-acid :Fish 96-hr :Fish 14-day :Daphnid 48-hr :Green Algae 96-hr :Fish 30-day :Daphnid :GreenAlgae :Fish (SW) 96-hr :Mysid Shrimp 96-hr :Fish (SW) :Mysid Shrimp (SW) :Earthworm 14-day LC50 LC50 LC50 EC50 ChV ChV ChV LC50 LC50 ChV ChV LC50 Note: * = asterisk designates: Chemical may not be soluble enoughto measure this predicted effect. Neutral Organics:

--------..------ For Fish LC50 (96-h),Daphnid LC50, Mysid: If the log Kow is greater than 5.0, or if the compound is solid and the LC50 exceeds the water solubility by lox,no effects at saturationare predicted. For Fish LC50 (14-day) and EarthwormLC50: If the log Kow is greater than 6.0, or if the compound is solid and the LC50 exceedsthe water solubility by lox,no effects at saturation are predicted. For Green Algae Acute Toxicity Values: If the log Kow of the chemical is greater than 6.4, or if the compound is solid and the EC50 exceeds the water solubility by lox,no effects at saturationare predicted for these endpoints. For All ChronicToxicity Values: Jf the log Kow of the chemical is greater than 8.0, or if the compound is solid and the ChV exceedsthe water solubility by lox,no effects at saturationare predicted for these endpoints: ECOSAR v1.00 SAR Limitations:

............................ Maximum LogKow:5.0 (Fish 96-hrLC50; Daphnid LC50, Mysid LC50) Maximum LogKow: 6.0 (Fish 14-dayLC50; EarthwormLC50) Maximum LogKow: 6.4 (Green AlgaeEC50) Maximum LogKow: 8.0 (ChV) Maximum Mol Wt: 1000SMILES :ClCClC(=N)N CHEM : CAS Num: ChemID1: ChemID2: ChemID3: MOL FOR: C4 H8 N2 MOL WT : 84.12 Log Kow: -1.72 (KowWin estimate) Melt Pt: Wat Sol: IE-I-006mg/L (WskowWin estimate) ECOSAR v1.OO Class(es)Found

.............................. Aliphatic Amines Predicted ECOSAR Class Organism Duration End Pt mg/L (ppm) ------- ---------- Aliphatic Amines :Fish 96-hr LC50 2559.187 Aliphatic Amines :Daphnid 48-hr LC50 119.684 Aliphatic Amines :Green Algae 96-hr EC50 15.333 Aliphatic Amines : Fish ChV 32.172 Aliphatic Amines : Daphnid ChV 0.023 Aliphatic Amines : Green Algae ChV 16.327 Aliphatic Amines :Fish (SW) 96-hr LC50 2642.790 Aliphatic Amines :Mysid Shrimp (SW) 96-hr LC50 124.511 Aliphatic Amines : GreenAlgae (SW) 96-hr EC50 15.246 Aliphatic Amines :Fish (SW) ChV 32.172 Aliphatic Amines :Mysid Shrimp (SW) ChV 0.023 Aliphatic Amines :Green Algae (SW) ChV 13.870

------------------ ------ Neutral Organic SAR : Fish 96-hr LC50 91250.281 (Baseline Toxicity) : Daphnid 48-hr LC50 33580.477 : Green Algae 96-hr EC50 3145.013 : Fish ChV 9404.913 :Daphnid ChV 1606.282 :Green Algae ChV 576.973 Note: * = asterisk designates:Chemical may not be soluble enough to measure this predicted effect. Aliphatic Amines: ---------------- For Fish 96-hr LC50: For aliphaticamines with log Kow greater than 7.0. a test duration of greater than 96 hrs may be required for proper expression of toxicity. Also, if the toxicity value obtainedby the use of this equationexceeds the water solubility (measured or estimated), mortalities greater than 50% would not be expected in a saturated solutionduring an exposure period of 96 hrs. For Daphnid 48-hr LC50: For aliphatic amines with log Kow greater than 5.0, a test duration of greater than 48 hrs may be required for proper expression of toxicity. Also, if the toxicity value obtainedby the use of this equationexceeds the water solubility (measured or estimated), significantmortalities would not be expected in a saturated solution during an exposureperiod of 48 hrs. For GreenAlgae Acute Toxicity Values: If the log Kow of the chemical is greater than 7, or if the compound is solid and the EC50 exceeds the water solubilityby IOX, no effects at saturationare predicted for these endpoints. For.Mysid ShrimpAcute Toxicity Values:-Ifthe log Kow of the chemical is greater than 6, or if the compound is solid and the EC50 exceeds the water solubilityby lox,no effects at saturationare predicted for these endpoints.For Fish and Daphnid Chronic Toxicity Values: If the log Kow of the chemical is greater than 8.0, or if the compound is solid and the ChV exceedsthe water solubilityby lox,no effects at saturation arepredicted for these endpoints. For Green Algae ChronicToxicity Values: If the log Kow of the chemical is greater than 7.0, or if the compound is solid and the ChV exceedsthe water solubility by lox,no effects at saturation are predicted forthese endpoints. ECOSAR v1.00 SAR Limitations:

............................ Maximum LogKow: 6.0 (Fish, Mysid LC50) Maximum LogKow: 5.0 (Daphnid LC50) Maximum LogKow: 7.0 (Green Algae EC50) Maximum LogKow: 8.0 (Fish, Daphnid ChV) Maximum LogKow: 7.0 (Green Algae ChV) Maximum Mol Wt: 1000 Baseline Toxicity SAR Limitations:

................................. Maximum LogKow: 5.0 (Fish 96-hrLC50; Daphnid LC50) Maximum LogKow: 6.4 (Green Algae EC50) Maximum LogKow: 8.0(ChV) Maximum Mol Wt: 1000

### Appendix 

### F: GENEEC Outputsfor Total Toxic Residue Approach
RUN No. 1 FOR ACP Acid ON Non -Crop Half-Life= 0 days RATE (#/AC) No.APPS & SOIL SOLUBIL APPL TYPE NO-SPRAY INCORP

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

.................................................................... .284( -284) 1 1 12.0 2810.0 AERL-B( 13.0) .O .O

FIELD AND STANDARD POND HALFLIFE VALUES (DAYS)

.................................................................... METABOLIC DAYS UNTIL HYDROLYSIS PHOTOLYSIS METABOLIC COMBINED (FIELD) RAIN/RUNOFF (POND) (POND-EFF) ( POND) ( POND)

....................................................................

373.00 2 N/ A .OO- .OO .OO .OO

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

.................................................................... PEAK MAX 4 DAY MAX 21 DAY MAX 60 DAY MAX 90 DAY GEEC AVG GEEC AVG GEEC AVG GEEC AVG GEEC

RUN No. 2 FOR ACP Acid ON Non-Crop1 Half-Life=l day

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

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

FIELD AND STANDARD POND HALFLIFE VALUES (DAYS)

.................................................................... METABOLIC DAYS UNTIL HYDROLYSIS PHOTOLYSIS METABOLIC COMBINED (FIELD) RAIN/RUNOFF (POND) (POND-EFF) ( POND) ( POND)

....................................................................

373.00 2 N/ A 1.00- 124.00 .OO 124.00

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

.................................................................... PEAK MAX 4 DAY MAX21DAY MAX60DAY MAX90DAY GEEC AVG GEEC AVG GEEC AVG GEEC AVG GEEC

RUN No. 1 FOR ACP Acid ON Turf Half-Life= 0 days

....................................................................

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

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

.................................................................... .108( .307) 3 30 12.0 2810.0 GRANUL( .O) .O .OFIELD AND STANDARD POND HALFLIFE VALUES (DAYS) METABOLIC DAYS UNTIL HYDROLYSIS PHOTOLYSIS METABOLIC COMBINED (FIELD) RAIN/RUNOFF (POND) (POND-EFF) ( POND) (POND) 

### '

__________-------__------------------------------------------------T

373.00 2 N/A -00- .OO .OO 

### .00 I
GENERIC EECS (IN MICROGRAMS/LITER (PPB)) Version 2.0 Aug 1, 200i

................................................................... I PEAK MAX 4 DAY MAX 21 DAY MAX 60 DAY MAX 90 DAY 

# ~ GEEC AVG GEEC AVG GEEC AVG GEEC AVG GEEC

................................................................... 16.82 16.82 16.82 16.80 16.79

RUN No. 2 FOR ACP Acid ON Turf Half-Life= 1 

### daq -------------------------------------------------------------------L

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

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

FIELD AND STANDARD POND HALFLIFE VALUES (DAYS) METABOLIC DAYS UNTIL HYDROLYSIS PHOTOLYSIS METABOLIC COMBINE9 (FIELD) RAIN/RUNOFF (POND) (POND-EFF) ( POND) ( POND) -------------------------------------------------------------------4

373.00 2 N/A 1.00- 124.00 .OO 124.00

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

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

### 7 GEEC AVG GEEC AVG GEEC AVG GEEC AVG GEEC ______---------_---------------------------------------------------* 16.82 16.75 16.31 15.36 14.69