UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON, D.C. 20460 

OFFICE OF PREVENTION, PESTICIDES AND 

TOXIC SUBSTANCES 

PC Code: 128968 

DP Barcode: 3361 79 

MEMORANDUM DATE: October 24,2007 

SUBJECT: EFED Risk Assessment for the Proposed New Uses of Fluroxypyr on Pome Fruit, 

Proso Millet, and Pearl Millet. 

FROM: Jonathan Angier, Ph.D., Environmental Scientist 

Fred Jenkins, MS, Biologist 

Environmental Risk Branch I1 

Environmental Fate and Effects Division (7507C) 

THRU: Dana Spatz, Acting Chief, 

Environmental Risk Branch I1 

Environmental Fate and Effects Division (7507C) 

TO: Shaja Brothers 

Registration Division (7505P) 

This memorandum pertains to proposed new uses for fluroxypyr on pome fiuit and millet. The 

results and conclusions presented here were obtained using the best available data; however, the 

accuracy of this memo may be limited by uncertainties and data gaps. If additional information 

is acquired in the future that might affect the results presented in this assessment, this knowledge 

will be considered and incorporated in future assessments (if appropriate). 

TEXT SEARCHABLE DOCUMENT
Data gaps that have been identified, and that could ultimately affect the outcome of fluroxypyr 

assessments, include: 

Rate of formation of fluroxypyr acid from fluroxypyr-MHE, and relative 

quantities produced under different conditions. 

Potential impact of both flwoxypyr-MHE and fluroxypyr (acid) co-existing 

within the same environment, as the MHE form degrades to the acid form. 

Lack of acceptable seedling emergence and vegetative vigor study testing 

fluroxypyr acid. 
ECOLOGICAL RISK ASSESSMENT FOR THE 

Registration of New Uses for Fluroxypyr 

USEPA PC Code: 128959 

Proposed New Uses: pome hit, proso millet, and pearl millet 

End Use Product: STARANE@ 

Environment Risk Branch I1 Team: 

Jonathan Angier, Ph.D., Environmental Scientist 

Fred Jenkins, MS, Biologist 

Environmental Fate and Effects Division (75 07C) 

Branch Chief Approval: 

Dana Spatz, Acting Chief 

Environmental Risk Branch I1 

Environmental Fate and Effects Division (7507C) 
Table of Contents 

I . EXECUTIVE SUMMARY ........................................................................................................ 6 

I1 . PROBLEM FORMULATION ................................................................................................ 10 

A . Stressor Source and Distribution ................................................................................ 10 

1 . Source and Intensity ......................................................................................... 10 

2 . Physical/Chemical Fate and Transport Properties ........................................... 11 

3 . Mode of Action ................................................................................................ 12 

4 . Overview of Pesticide Usage ........................................................................... 12 

B . Receptors ..................................................................................................................... 12 

1 . Aquatic Effects .................................................................................................. 13 

2 . Terrestrial Effects ............................................................................................. 14 

3 . Ecosystems at Risk ........................................................................................... 15 

C . Assessment Endpoints ................................................................................................. 15 

D . Conceptual Model ....................................................................................................... 17 

1 . Rational for Risk Hypothesis Selected for Assessment ................................... 17 

2 . Risk Hypothesis ................................................................................................. 19 

3 . Diagram ............................................................................................................ 20 

E . Analysis Plan ............................................................................................................... 22 

1 . Preliminary Identification of Data Gaps and Methods ..................................... 22 

2 . Measures to Evaluate Risk Hypothesis and Conceptual Model ....................... 24 

a . Measures of Exposure .......................................................................... 24 

b . Measures of Effect ............................................................................... 26 

I11 . ANALYSIS ................................. ....................................................................................... 28 

A . Exposure Characterization .......................................................................................... 28 

1 . Environmental Fate and Transport ................................................................... 28 

a . Degradation and Metabolism ........................................................... 28 

b . Transport and Mobility ........................................................................ 28 

c . Field Studies ........................................................................................ 28 

d . Bioaccumulation ................................................................................ 29 

2 . Measures of Aquatic Exposure ........................................................................ 29 

a . Aquatic Exposure Modeling ................................................................. 29 

b . Water Monitoring Data ...................................................................... 30 

3 . Measures of Terrestrial Exposure .................................................................... 30 

a . Dietary Residues ................................................................................... 30 

b . Exposure Modeling for Non-Target Plants .......................................... 31 

c . Spray Drift Analysis ............................................................................. 31 

C . Ecological Effects Characterization ............................................................................ 32 

1 . Aquatic Effects Characterization ..................................................................... 32 

a Aquatic . Animals .................................................................................... 33 

(1) Acute Effects ........................................................................... 33 

(2) Chronic Effects ........................................................................ 35 
(3) Sublethal Effects ...................................................................... 35 

(4) Field Studies ...................................................................... 35 

b . Aquatic Plants ..................................................................................... 35 

2 . Terrestrial Effects Characterization ................................................................. 35 

a . Terrestrial Animals ............................................................................... 35 

(1) Acute Effects ........................................................................... 37 

(2) Chronic Effects ........................................................................ 37 

(3) Sublethal Effects ................................................................ 3 8 

(4) Field Studies ............................................................................ 38 

b Terrestrial Plants . .................................................................................. 38 

IV . RISK CHARACTERIZATION ............................................................................................. 39 

A . Risk Estimation . 'Integration of Exposure and Effects Data ...................................... 39 

1 . Non-target Animals and Plants ........................................................................ 39 

B . Risk Description ........................................................................................................... 44 

1 . Risks to Aquatic Organisms .............................................................................. 44 

a . Animals ................................................................................................. 44 

b . Plants .................................................................................................... 45 

2 . Risks to Terrestrial Organisms ......................................................................... 45 

a . Animals ................................................................................................. 45 

b . Plants .................................................................................................... 46 

C . Federally Threatened and Endangered (Listed) Species Concerns ............................. 46 

a . Action Area ..................................................................................................... 46 

b Taxonomic . Groups Potentially at Risk ............................................................ 47 

(1) Discussion of Risk Quotients .............................................................. 47 

c . Indirect Effects Analysis .................................................................................. 49 

d . Critical Habitat ................................................................................................. 50 

e Co-occurrence . Analysis .................................................................................... 51 

V . REFERENCES ........................................................................................................................ 53 

IV . APPENDICES ....................................................................................................................... 54 
I. EXECUTIVE SUMMARY 

A. Nature of Chemical Stressor 

STARANEB (Fluroxypyr-MHE) is a herbicide intended primarily for postemergent selective 

control of broadleaf weeds. It is currently registered for use on wheat, barley, oats, corn, 

sorghum, fallow cropland, non-cropland (i.e., rangeland), and others. This Ecological Risk 

Assessment regards the proposed new uses on pome hit and millet. 

Fluroxypyr-MHE is formulated as an emulsifiable concentrate that is mixed with water and 

applied as ground or aerial spray. It may be applied as broadcast or banded, or even as spot 

treatment by hand application. STARANE' can be used for pre-plant or post-emergent 

broadleaf weed suppression. 

The proposed new uses for Fluroxypyr-MHE are: Pome Fruit, Group 11; Millet; Proso Millet; 

and Pearl Millet. The proposed new use label for Pome Fruit includes potentially higher 

maximum rates for this use (specifically, application rates for "Weeds Suppressed") than for 

most already approved uses. The proposed new use label states: "Do not apply more than 2 213 

pints per acre (0.5 lb ailacre) per year." This assessment reflects a high-exposure scenario by 

assuming the maximum application amount of 0.5 lb ailA is used per year. 

B. Potential Risks to Non-target, non-listed Organisms 

Based on EFED's evaluation of fluroxypyr-MHE, which is the parent compound that degrades to 

the herbicidally active fluroxypyr acid, risk above the Agency level of concern for listed and 

nonlisted terrestrial dicot plant species may result from the proposed new uses. Based on limited 

supplemental terrestrial plant toxicity data, fluroxypyr, the degradate of fluroxypyr-MHE, may 

pose a greater risk to nontarget terrestrial plants than fluroxypyr-MHE. 

EFED does not expect fluroxypyr-MHE to pose a significant risk to birds, mammals, fish, 

aquatic invertebrates, or aquatic non-vascular plants. 

C. Conclusions - Exposure Characterization 

Fluroxypyr MHE is expected to degrade to its herbicidal active ingredient, fluroxypyr acid 

following application. Degradation to active ingredient fluroxypyr is expected to occur primarily 

over the course of days or weeks, depending on conditions. Therefore, EFED's assessment 

expects terrestrial organisms to potentially be exposed to both fluroxypyr MHE and fluroxypyr 

(acid). However, EFED expects aquatic organisms to be predominately exposed to fluroxypyr 

because of its rapid formation, under aerobic aqueous conditions (tla = 5 days), from its parent 

compound fluroxypyr MHE. In addition, unlike in the terrestrial environment (where potential 

exposure exists immediately following application), most of the aquatic exposure should occur 

when the chemical is transported into water bodies following a rain event (with conversion Erom 

MHE to acid form occurring in the interim). Nevertheless, some MHE may be conveyed directly 

to the water body as spray drift (andlor if runoff occurs soon after application). Consequently, 

while EFED's aquatic assessment would presumably focus primarily on assessing the risk of 

fluroxypyr exposure to aquatic organisms, some exposure to fluroxypyr MHE is also possible 
and cannot be discounted. In the terrestrial environment fluroxypyr MHE is also expected to 

degrade to fluroxypyr, but typically not as rapidly as in the aquatic environment. Thus EFED 

anticipates that terrestrial organisms may be readily exposed to both fluroxypyr MHE and 

fluroxypyr. Accordingly, this assessment evaluated the risk posed to terrestrial species exposed 

to either fluroxypyr MHE or fluroxypyr. 

D. Conclusions - Effects Characterization 

Table 1, below, provides a characterization of how toxic fluroxypyr MHE and fluroxypyr is to 

aquatic organisms. These toxicity data are the most sensitive toxicity endpoints available for 

aquatic organisms. These toxicity data will be used to assess the risk of fluroxypyr and 

fluroxypyr MHE to aquatic organisms. 

Table 1. Aquatic organism toxicity characterizations for fluroxypyr MHE and its Herbicidal Degradate 

As demonstrated in Table 1, above, fluroxypyr is slightly to practically nontoxic to aquatic 

organisms, Fluroxypyr MHE toxicity studies were only able to classify aquatic organism 

toxicity for marine estuarine invertebrates which was shown to be very highly toxic to these 

organism. No chronic toxicity data are available for aquatic organisms for either fluroxypyr or 

fluroxypyr MHE. (See Appendix A for further details on all aquatic toxicity studies) 

Fluroxypyr 

Taxonomic Group 

Freshwater Fish 

Freshwater Fish 

EstuarineMarine Fish 

Estuarinehiarine Fish 

Freshwater Invertebrates 

Freshwater Invertebrates 

Marine 

Estuarine Invertebrates 

Marine 

Estuarine Invertebrates 

Aquatic nonvascular plants 

Aquatic nonvascular plants 

Aquatic vascular plants 

Aquatic vascular plants 

Below, Table 2 presents the characterizations of how toxic fluroxypy MHE and fluroxypyr are to 

terrestrial organisms. These data are the most sensitive fluroxypyr MHE and fluroxypyr toxicity 

endpoints available for terrestrial organisms. These toxicity values will be used to assess the risk 

Chemical 

Fluroxypyr 

Fluroxypy MHE 

Fluroxypyr 

Fluroxypyr MHE 

Fluoxypyr 

Fluroxypyr MHE 

Fluroxypyr 

Fluroxypyr MHE 

Fluroxypyr 

Note 1: This item is not applicable (NA) because the Agency does not assign acute toxicity characterizations to 

aquatic plant toxicity endpoints. 

Note 2: This item is not applicable (NA) because there are no guideline aquatic plant chronic toxicity studies. 

Fluroxypyr MHE 

Fluroxypyr 

Fluroxypyr MHE 

Principal Acute 

Toxicity Endpoint 

LCSo = 14.3 ppm ai 

LC50 = 13.2 ppm ai 

No Data Available 

> 0.087 ppm ai 

ECSo > 100 ppm ai 

ECS0 > 0.109 ppm ai 

5 1 ppm ai 

0.068 ppm ai 

ECso > 100 ppm ai 

0.29 ppm ai 

No Data Available 

> 2.3 ppm ai 

Acute Toxicity 

Categories 

Slightly toxic 

Slightly toxic 

NA 

Not determined 

Practically 

nontoxic 

Not determined 

Slightly toxic 

Very highly 

toxic 

NA ' 

NA 

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

NA 

Principal Chronic 

Toxicity 

Endpoint 

No Data Available 

No Data Available 

No Data Available 

No Data Available 

No Data Available 

No Data Available 

No Data Available 

No Data Available 

NA 

NA 

NA 

NA 
of fluroxypyr MHE and fluroxypyr to terrestrial animals. 

Table 2. Terrestrial organisms 

Taxonomic Group 

Birds 

Birds 

Mammals 

Mammals 

Terrestrial Plants 

toxicity 

Chemical 

Fluroxypyr MHE 

Fluroxyp yr 

Fluroxypyr MHE 

Fluroxypyr 

Fluroxypyr MHE 

Fluroxypyr 

characterizations of flurorypyr 

Principal Acute 

Toxicity Endpoint 

Acute dietary LC50 

> 5620 mg ailkg 

Acute oral toxicity 

data not available 

Acute dietary LC50 

> 5620 mg ailkg 

Acute oral LDso > 

2000 mg dkg 

LD50 79 1 mg dkg 

No Data Available 

Seedling Emergence 

dicot NOAEC = 

0.031 lbs. ailacre 

Monocot EC25 = 

0.075 lbs. ailacre 

Seedling Emergence 

monocot NOAEC = 

0.124 lbs. dacre 

EC25 > 0.25 Ibs. 

ailacre 

Vegetative vigor 

dicot 

NOAEC = 0.001 

lbs. dacre 

ECZ5 = 0.004 lbs. 

ailacre 

Vegetative vigor 

monocot NOAEC = 

0.062 lbs. ailacre. 

EC25 = 0.124 lbs. 

ailacre 

Seedling emergence 

dicot NOEAC = not 

determined 

ECZ5 = 0.025 lb ai/A 

MIIE and fluroxypyr 

Acute Toxicity 

Categories 

Practically 

nontoxic 

Practically 

nontoxic 

Practically 

nontoxic 

----------- 

NA' 

NA' 

Principal Chronic 

Toxicity 

Endpoint 

LOAEC = 500 

PPm ai 

NOAEC = 250 

ppm ai 

No Data Available 

NOAEC = 1000 

ppm ai 

No Data Available 

NA~ 

NA~ 
plant toxicity endpoints. 

Note 2: This item is not applicable (NA) because there no guideline terrestrial plant chronic toxicity studies. 

As demonstrated in Table 2 above, fluroxypyr MHE and fluroxypyr are slightly to practically 

nontoxic to birds, and mammals. The available avian chronic toxicity study demonstrated that 

fluroxypyr MHE caused egg yolk peritonitis in hens at a NOEAC of 250 ppm. The mammalian 

chronic toxicity studies demonstrated that the most sensitive chronic toxic endpoint was a 

parental NOAEL of 1000 ppm for increased kidney weight with corresponding gross and 

microscopic findings including papillary atrophy, edema, necrosis, hyperplasia of the pelvic 

epithelium, degenerationhegeneration of the tubular epithelium, tubulo-interstitial nephritis, and 

dilatation of the tubules (See Appendix A for further details on all terrestrial organism toxicity 

studies). 

E. Uncertainties and Data Gaps 

Fate Uncertainties and Data Gaps 

Once fluroxypyr MHE is applied to the environment, it is expected to degrade to its herbicidal 

active ingredient, fluroxypyr acid (often referred to simply as fluroxypyr). The fate of 

fluroxypyr-MHE in the environment is complicated by uncertainty in the formation rate and 

distribution of the initial degradate fluroxypyr acid (active ingredient in STARANE' fluroxypyrMHE) following spray application. Fluroxypyr-MHE application rates are established based 

upon acid equivalents (ae) pursuant to fluroxypyr acid as the active ingredient (ai). However, the 

solubility of fluroxypyr-MHE is much lower (-0.9 mg/L) than fluroxypyr acid (-8,000 mg/L); 

according to mixing/application instructions, the tank must be agitated before and during 

applications to allow undissolved material to remain in suspension. In neutral or low pH 

aqueous conditions, fluroxypyr-MHE is sufficiently stable such that spray distributed on a target 

zone will initially contain mostly the fluroxypyr-MHE form. Under field conditions it is likely 

that most of the MHE will convert to the active ingredient (fluroxypyr acid) in the course of 

several days or weeks. In the EFED models, it is assumed that the initial spray contains all the 

active ingredient, and that degradation rates for total toxic residues (fluroxypyr MHE and 

fluroxypyr acid) commence immediately after spraying. There may be initial on-site exposure to 
the MHE form after spraying, with degradation occurring first from the MHE to acid form, then 

to other (less-toxic) forms. Actual exposure could then potentially be longer than assessed. 

Conversely, this effect may also attenuate the impact of the active ingredient, as it will be 

introduced onto the site more gradually (according to degradation rates). In high-pH conditions, 

though, degradation of both MHE and acid forms are expected to occur more rapidly. For the 

purpose of EFED assessments, the most conservative fate and effects input parameters are used 

where available; in this instance, it is most conservative to use the values for total toxic residues 

for exposure. 

Ecological Effects Uncertainties and Data Gaps 

Currently, there is a registrant submitted supplemental fluroxypyr seedling emergence study and 

a registrant submitted supplemental fluroxypyr vegetative vigor study. Both studies are deemed 

supplemental because of significant deviations from the study guidelines. Neither of these 

studies produced valid NOAEC values to calculate the risk of fluroxypyr to endangered 

terrestrial plant species. However, the EC25 results of these studies indicate that fluroxypyr is 

substantially more toxic to plants than its parent compound fluroxypyr MHE. Despite the 

available supplemental fluroxypy terrestrial plant toxicity data, EFED would need guideline 

terrestrial plant toxicity data on fluroxypyr in order to more definitively access the risk of 

fluroxypy to terrestrial plants, especially endangered plants. 

11. PROBLEM FORMULATION 

A. Stressor Source and Distribution 

1 Source and Intensity 

Fluroxypyr MHE (active ingredient: fluroxypyr; trade name: StaraneB) is an auxin-type 

herbicide used for control of broadleaf weeds in a variety of crop and non-crop settings. Figure 1 

(below) shows the chemical structure of fluroxypyr (ai); Figure 2 shows the chemical structure of 

parent fluroxypyr-MHE. Fluroxypyr-MHE is formulated to be mixed with water and applied as 

spray. It may be applied as aerial spray, 'broadcast' or 'banded' ground-level spray, or as spot 

treatment by hand spray. 

Figure 1. Fluroxypyr Chemical Structure 
Figure 2. Fluroxypyr MHE Chemical Structure 

2. Physical/Chemical Fate and Transport Properties 

Common Name: 

Chemical Name: 

PC Code: 

Molecular Formula: 

Molecular Weight: 

Density: 

Melting Point: 

Boiling Point: 

Vapor Pressure: 

Water Solubility: 

Chemical Name: 

Molecular Formula: 

Molecular Weight: 

Density: 

Melting Point: 

Boiling Point: 

Vapor Pressure: 

Water Solubility: 

staranem 

Fluroxypyr methylheptyl ester 

128968 

CI~H~ICL~FN~O~ 

367 dm01 

1. g/mL 

56-57°C 

155-181°C 

9.42" 1 o-~ mmHg 

0.9 mg/L 

Fluroxypyr (acid) 

C7H5Cl2FN2O3 

255 dm01 

1.3 g/mL 

232-233°C 

N/A 

1.07* mmHg 

7950 mg/L 

3. Mode of Action 

Fluroxypyr is a broadleaf weed herbicide in the Pyridinoxy acid chemical family. The active 

ingredient fluroxypyr is applied as fluroxypyr-MHE, which is rapidly converted to fluroxypyr 

acid following plant uptake. Fluroxypyr acts by inducing leaf curling and other responses typical 

of auxin-type herbicides. 
4. Overview of Pesticide Usage 

Fluroxypyr-MHE is currently registered for many uses, including: small grains, sweet corn, field 

corn, fallow cropland, and on-farm non-cropland. 

B. Receptors 

Receptors are non-target organisms which potentially could be exposed to a chemical stressor 

such as fluroxypyr MHE andlor its primary degradate fluroxypyr. In the initial stages of a risk 

assessment both aquatic and terrestrial species are considered. Direct acute and chronic 

exposures are considered initially. Aquatic animals of potential concern include freshwater fish 

and invertebrates, estuarine and marine fish and invertebrates, and amphibians. Terrestrial 

animals of potential concern include birds, mammals, and beneficial insects. In determining 

which receptors should be evaluated in a risk assessment, registrant-submitted toxicity studies 

are considered. The measures of effects for Level 1 screening assessments are generally based 

on registrant-submitted toxicity studies performed on a limited number of organisms 

representing broad taxonomic groups (e.g., birds, mammals, fish, invertebrates, plants). 

The taxonomic groups and test species typically evaluated for ecological effects in screeninglevel risk assessments are shown in Table 3. Within each of these broad taxonomic groups, the 

most sensitive acute andlor chronic endpoint is selected from the available test data and is used 

in the risk assessment. 
1. Aquatic Effects 

Table 3. Taxonomic Groups and Test Species Evaluated for Ecological Effects in Screening-level Risk 

Assessments. 

Aquatic effects are determined through assessment of potential impacts of exposure to aquatic 

organisms. Once fluroxypyr MHE is applied to the environment, it is expected to degrade to its 

herbicidal active ingredient, fluroxypyr. The degradation is expected to be very rapid once 

fluroxypyr MHE comes in contact with water. Thus, aquatic organisms may be exposed to both 

fluroxypyr MHE and fluroxypy. However, EFED expects aquatic organisms to be 

predominately exposed to fluroxypyr because of its rapid formation from its parent compound 

(fluroxypyr MHE), and because Starme@ is not intended to be applied directly to water. 

Nevertheless, EFED's aquatic assessment focuses on assessing the risk of exposure to aquatic 

organisms from fluroxypyr total toxic residues (MHE and acid forms) . Fish, aquatic-phase 

amphibians, aquatic invertebrates (epi-benthic, benthic, sediment dwelling), and aquatic plants 

may all be potential receptors for environmental exposure to fluroxypyr residues. 

Taxonomic group 

Birds " 

Mammals 

Freshwater fish 

Freshwater invertebrates 

Estuarine and marine fish 

Estuarine and marine invertebrates 

Terrestrial plants 

Aquatic plants and algae 

The following is a list of registrant submitted toxicity data that is utilized to evaluate the impact 

of fluroxypyr on aquatic organisms. 

Example(s) of representative species 

mallard duck (Anas playtrhynchos) 

bobwhite quail (Colinus virginianus) 

laboratory rat (Rattus nowegicus) 

bluegill sunfish (Lepomis macrochirus) 

rainbow trout (Oncorhynchus mykiss) 

water flea (Daphnia magna) 

sheepshead minnow (Cyprinodon variegatus) 

eastern Oyster (Crassostrea virginica) 

mysid Shrimp (Americamysis bahia) 

monocots - corn (Zea mays) 

dicots - soybean (Glycine ma) 

duckweed (Lemna gibba) 

green algae (Selenastrum capricornutum) 

" Birds represent surrogates for amphibians (terrestrial phase) and reptiles. 

Freshwater fish may be surrogates for amphibians (aquatic phase). 

Four species of two families of monocots, of which one is corn; six species of at least four dicot families, of 

which one is soybeans. 
Available Aquatic Organism Acute Toxicity Data 

Five fluroxypyr MHE freshwater fish acute-toxicity LCs0 studies testing inland 

silverside, bluegill sunfish, rainbow trout, and golden orfe 

Three fluroxypyr freshwater fish acute toxicity LCs0 studies testing rainbow trout, 

bluegill sunfish, and golden orfe. 

Two fluroxypyr MHE .freshwater invertebrate acute toxicity LCs0 studies testing 

waterflea 

Two fluroxypyr freshwater invertebrate ECso studies testing water flea. 

Two fluroxypyr marinelestuarine fish acute toxicity LCs0 studies testing Atlantic 

silverside, and sheepshead minnow. 

Four fluroxypyr MHE marinelestuarine invertebrate ECS0 studies testing eastern 

oyster, grass shrimp, and pink shrimp. 

Two fluroxypyr marinelestuarine invertebrate ECso studies testing eastern oyster and 

grass shrimp. 

These studies are summarized in detail in Appendix A, 

2. Terrestrial Effects 

Terrestrial effects are evaluated through assessment of the potential impact of exposure on 

representative terrestrial organisms. In the terrestrial environment fluroxypyr MHE is expected 

to degrade to fluroxypyr (acid). Terrestrial organisms will be exposed to both fluroxypyr MHE 

and fluroxypyr soon after application. Moreover, fluroxypyr MHE degradation to fluroxypyr in 

the terrestrial environment may not occur as rapidly as in the aquatic environment. Thus EFED 

anticipates that terrestrial animals may be readily exposed to both fluroxypyr MHE and 

fluroxypyr. Consequently, this assessment evaluated the risk posed to terrestrial animals 

exposed to either fluroxypyr MHE or fluroxypyr. Reptiles, birds, mammals, invertebrates, such 

as honeybees and earthworms, and non-target plants are potential terrestrial receptors of concern 

for environmental exposure to fluroxypyr MHE and fluroxypyr. A summary of the registrantsubmitted laboratory studies on the toxicity of fluroxypyr and fluroxypyr MHE to terrestrial 

organisms are available below. 

Available Terrestrial Organism Acute Toxicity Data 

Two fluroxypyr acute oral LD50 studies testing mallard duck, and bobwhite quail 

Two fluroxypyr acute dietary LC50 studies testing bobwhite quail and mallard duck 
Three fluroxypyr MHE acute dietary LC50 studies testing mallard duck and bobwhite 

quail 

Two fluroxypyr MHE avian reproduction studies for bobwhite quail, and mallard duck 

One fluroxypyr acute oral toxicity study for rat 

One fluroxypyr reproductive toxicity test for rat 

One fluroxypyr vegetative vigor toxicity study and one seedling emergence toxicity 

study. 

One fluroxypyr MHE vegetative vigor toxicity study and one seedling emergence toxicity 

study. 

These studies are summarized in detail in Appendix A. 

3. Ecosystems at Risk 

The ecosystems at risk are typically national in scope. Consequently, it may not be possible to 

identify specific ecosystems at the screening level. However, in general terms, ecosystems 

potentially at risk could be identified as those ecosystems in close proximity to sites where 

fluroxypyr MHE is used. These ecosystems could include: 

Freshwater habitats, such as streams, rivers, or lakes 

Estuaries 

Forests 

Grasslands 

Wetlands 

Ecosystems potentially at risk are expressed in terms of the selected assessment endpoints. The 

typical assessment endpoints for screening-level pesticide ecological risks are discussed in 

Section 1I.C (Assessment Endpoints). 

C. Assessment Endpoints 

An assessment endpoint represents an actual environmental value that is to be protected 

(ecological entity) as well as its attributes or characteristics. Examples of specific endpoints 

include individual bird survival, diversity of a fish community, and sustainability of a bird 

population. Each assessment endpoint needs one or more "measures of effect", which are 

changes in the attributes of an assessment endpoint itself in response to exposure to a pesticide. 

Measures of effect are discussed in more detail in Section II.E.2.b. 
The selection of the assessment endpoints is based on valued entities (i.e., ecological receptors), 

the ecosystems potentially at risk, the migration pathways of pesticides, and the routes by which 

ecological receptors are exposed to pesticides. Clearly defined assessment endpoints are 

important because they provide direction and boundaries in the risk assessment for addressing 

risk management issues of concern. 

The typical assessment measures of effect for screening-level pesticide ecological risk 

assessments are reduced survival, impaired reproduction and impaired growth for both aquatic 

and terrestrial animal species. For terrestrial plants including those in semi-aquatic areas, the 

screening assessment endpoint is the perpetuation of populations of non-target species (based on 

data from studies using crops and non-crop plant species). Existing testing requirements for 

terrestrial plants and semi-aquatic plants have the capacity to evaluate emergence of seedlings , 

and vegetative vigor. Although it is recognized that the measures of effect of seedling 

emergence and vegetative vigor may not address all terrestrial and semi-aquatic plant life cycle 

components, it is assumed that impacts at emergence and in active growth have the potential to 

impact individual competitive ability and reproductive success. The assessment endpoint for 

aquatic plants and algae is the maintenance and growth of standing crop or biomass. 

Measurements of effects for this assessment endpoint focus on algal and vascular plant (i.e., 

duckweed) growth rates and biomass measurements. 

In order to protect threatened and endangered species, all assessment endpoints are measured at 

the individual level. Although all endpoints are measured at only the individual level, they 

provide insight into risks at higher levels of biological organization (e.g. populations and 

communities). For example, pesticide effects on individual survivorship have important 

implications for both population rates of increase and habitat carrying capacity. 

The ecological relevance of selecting the above-mentioned assessment measures of effect is as 

follows: 1) complete exposure pathways exist for these receptors; 2) the receptors may be 

potentially sensitive to pesticides in affected media and in residues on plants, seeds, and insects; 

and 3) the receptors could potentially inhabit areas where pesticides are applied, or areas where 

runoff and/or spray drift may impact the sites because suitable habitat is available. 

This ecological risk assessment considers maximum application rates of fluroxypyr MHE to 

fields that have vulnerable soils, maximum number of applications (as well as single 

applications), and minimum intervals for uses on representative crops to estimate exposure 

concentrations. In addition, this assessment is not intended to represent a site- or time-specific 

analysis. Instead, this assessment is intended to represent high-end exposures at a national level. 

Likewise, the most sensitive toxicity measures of effect are used from surrogate test species to 

estimate treatment-related direct effects on survival, reproduction, and growth. Toxicity tests are 

intended to determine effects of fluroxypyr-MHE and its primary degradate, fluroxypyr, 

exposure on birds, mammals, fish, terrestrial and aquatic invertebrates, and plants. These tests 

include short-term acute, subacute, and reproductive studies and are typically arranged in a 

hierarchical or tiered system that progresses from basic laboratory tests to applied field studies. 

The toxicity studies are used: 1) to evaluate the potential of fluroxypyr MHE and fluroxypyr to 

cause adverse effects, 2) to determine whether further testing is required, and 3) to determine the 
need for precautionary label statements to minimize the potential adverse effects to non-target 

animals and plants (CFR 40 5 158.202,2002). 

A summary of the assessment endpoints and measurements of effects selected to characterize 

potential ecological risks associated with exposure to fluroxypyr MHE is provided in Table 4. 

1 I Table 4. Summary of Assessment and Measurement Endpoints for Fluroxypyr MHE and its primary 

degradate, Fluroxypyr (TGAI). I 

I Assessment Endpoint I Measurement Endpoint I 

2. Abundance (i.e., survival) of individuals and I 2 Rat developmental toxicity chronic NOAEL and 

populations of mammals. LOAEL I 

1. Abundance (i.e., survival) of individuals and 

populations of birds. 

la. Bobwhite quail acute oral LD5O. 

lb. Bobwhite quail and mallard duck subacute dietary 

LC50. 

3. Survival and reproduction of individuals and 

communities of freshwater fish and invertebrates. 

D. Conceptual Model 

3a. Rainbow trout and bluegill sunfish acute LC50. 

3b. Water flea acute LCs0. I 

4. Survival of terrestrial plants 

5. Survival and reproduction of aquatic plants 

A conceptual model (CM) consists of a written descriptiodrisk hypothesis and visual 

representation of the predicted relationships between a stressor, the potential routes of exposure, 

and the attribute changes of concern for the assessment endpoint. Visual representations of the 

risk hypothesis assessed in this screening level risk assessment are provided for fluroxypyr MHE 

applied as a ground or aerial spray in Figure 3. 

5a. Seedling emergence EC25 and NOAEC in 

Cocklebur. 

5b. Vegetative vigor EC25 and NOAEC in Cocklebur. 

6a. Duckweed ECS0 and NOAEC. 

6b. Green algae, bluegreen algae, freshwater diatom, 

and marine diatom EC50 and NOAEC. 

1. Rational for Risk Hypothesis Selected for Assessment 

LD50 = Lethal dose to 50% of the test population. 

NOAEC = No-observed-adverse-effect level. 

LOAEC = Lowest-observed-adverse-effect level. 

(EC50) = Lethal (effective) concentration to 50% of the test population. 

LC25 (EC25) = Lethal (effective) concentration to 25% of the test population. 

A risk hypothesis is a statement of the predicted relationship between a chemical stressor (such 

as fluroxypyr MHE and its' herbicidal active degradate, fluroxypyr) and the environment into 

which it is released. Within the context of this assessment, the risk hypothesis takes into account 

elements necessary for pathways of exposure to be completed, and makes assumptions and 
predictions about whether completed exposure pathways could result in adverse effects upon 

receptors of ecological interest. 

An exposure pathway is the means by which a chemical of interest, such as fluroxypyr MHE, 

and its' herbicidal active degradate, fluroxypyr moves in the environment from a source to an 

ecological receptor. For an ecological exposure pathway to be complete, there must be a source, 

a release mechanism, an environmental transport medium, a point of exposure for an ecological 

receptor (this is a location), and a feasible route of exposure for the receptor (for example, oral, 

dermal or inhalation) at the exposure point. 

a) Terrestrial Ecosvstems 

Once fluroxypyr MHE is applied to the target plant it is hydrolyzed to the parent acid, fluroxypyr 

which is the herbicidal active form, and translocated rapidly to other parts of the plants. 

Fluroxypyr acts by inducing characteristic auxin-type responses, e.g. leaf curling. As such, 

potentially complete pathways of fluroxypyr MHE and its degradate, fluroxypyr, exposure to 

nontarget organisms could include: 

exposure of terrestrial plants through foliar contact and root uptake; 

exposure of terrestrial wildlife (birds, mammals, invertebrates) through oral and dermal 

contact with fluroxypyr MHE and its herbicidal degradate, fluroxypyr, applied to plants 

and soil; through inhalation and dermal contact with spray drift; and through oral and 

dermal contact with fluroxypyr in water. 

In regards to the terrestrial environment, the highest fluroxypyr MHE and fluroxypyr residue 

levels are expected to be located in the soil and on foliage, seeds, insects, and soil invertebrates 

on treated fields immediately following applications. While spray drift fi-om ground and aerial 

sprays may result in transport and deposition of fluroxypyr MHE onto off-target field surface 

soil, foliage, seeds, insects or soil invertebrates, the highest concentration for these media are still 

expected to be those on the treated field. 

Risk hypotheses evaluating risk of fluroxypyr MHE and fluroxypyr via exposure of the dietary 

route was developed for screening in this risk assessment. These risk hypotheses include impacts 

fi-om dietary exposure to fluroxypyr MHE and fluroxypyr by secondary and tertiary consumers, 

both vertebrates and invertebrates, representing common ecological functional feeding groups 

(i.e. herbivores, insectivores). Herbivores, as used here, include animals that feed on foliage 

(stems and leaves), seeds, and/or hits; the term granivore is sometimes used to identify animals 

that feed primarily on seeds. Omnivores are also potentially exposed but are not specifically 

included in the receptor list for a screening level risk assessment because exposure 

concentrations and risk levels will fall between the exclusive feeding groups. Because toxicity 

data for reptiles and terrestrial phase amphibians are rarely available, risk hypotheses addressing 

dietary exposure for birds were used as representative as risk to reptiles and terrestrial phase 

amphibians (USEPA 2004). While the selected risk hypotheses only address terrestrial wildlife 

exposure via dietary exposure fi-om residues on foliage and insects, information or data that are 
available to indicate that other routes of exposure may be potentially significant contributors to 

wildlife risk and would affect the outcome of risk conclusions are considered in the risk 

characterization. 

b) Aquatic Ecosvstems 

Potential pathways of exposure in these ecosystems are: 

exposure of aquatic plants via direct contact; 

exposure of aquatic animals via dermal contact and uptake through gills, and other water 

filtration devices and uptake through integument. 

exposure of soil dwellers, epi-benthic, and some benthic organisms via sediments. 

2. Risk Hypothesis 

Terrestrial Ecosystems 

terrestrial herbivore and insectivore vertebrates (birds, mammals, reptiles, terrestrial 

phase amphibians) are subject to reduced number and reproduction when exposed to 

fluroxypyr MHE and fluroxypyr residues on seeds, insects, foliage due to direct 

deposition or spray drift from labeled use of the pesticide. 

upland plants (non-wetlandlriparian) are subject to reduced number and vegetative vigor 

in areas adjacent to treated field when exposed to fluroxypyr MHE and fluroxypyr 

residues in soil from spray drift alone or in concert with surface water run-off from 

labeled use of the pesticide. 

upland plants adjacent to treated field are subject to reduced vegetative vigor when 

exposed to fluroxypyr MHE and fluroxypyr residues on foliage due to spray drift from 

labeled use of pesticide. 

ripariadwetland plants adjacent to treated field are subject to reduced numbers when 

exposed to fluroxypyr MHE and fluroxypyr residues in soil from spray drift alone or in 

concert with surface water run-off from labeled use of the pesticide. 

ripariadwetland plants adjacent to treated field are subject to reduced numbers when 

exposed to fluroxypyr MHE and fluroxypyr residues on foliage due to spray drift from 

labeled use of pesticide. 

Aquatic Ecosystems 

aquatic invertebrates and fish in surface water adjacent to treated fields are subject to 

mortality and reduced reproduction when exposed to fluroxypyr residue in water due to 

spray drift alone or in concert with run-off from labeled use of the pesticide; exchange of 

water and sediments between wetland areas and associated water bodies may also be a 

factor. 
aquatic plants in surface water adjacent to treated field are subject to reduced growth and 

reduced biomass when exposed to fluroxypyr residue in water due to spray drift alone or 

in concert with run-off fiom labeled use of the pesticide. 

The data available for assessing the potential impairment of survival, reproduction, and growth 

associated with the potentially complete pathways of exposure were presented in the previous 

section (Section 3C) and summarized in Table 4. 

Based on the above considerations, this screening-level assessment presumes the following risk 

hypothesis: 

Fluroxypyr MHE application to agricultural fields may result in the exposure of nearby 

non-target plants and animals, in both terrestrial and aquatic ecosystems. Such exposures 

have the potential to cause acute or chronic effects to terrestrial or aquatic animals, and to 

impair growth and survival of terrestrial and aquatic plants. 

3. Diagram 

Figure 3 is a visual depiction of the conceptual model preliminarily used to assess the potential 

ecological impacts of fluroxypyr MHE and fluroxypyr on non-target species and the 

environment. Dashed lines indicate routes that are either unknown or highly unlikely given what 

is understood about this chemical. 
+ + 

Direct Contact Difict Contact1 GilllIntegument U take 

And I gestion P Root ptake Y P 

Figure 3. Conceptual Model for Fluroxypyr MHE New Uses. 
E. Analysis Plan 

This assessment focuses on adverse acute and chronic reproductive effects to terrestrial and 

aquatic wildlife associated with the proposed new uses for fluroxypyr MHE. This analysis 

plan identifies the approach, methods, specific models, information, and data that will be 

used to estimate and evaluate risks from proposed labeled uses of fluroxypyr MHE based on 

the conceptual model and risk hypotheses. 

1. Preliminary Identification of Data Gaps and Methods 

a) Data Gaps and Uncertainties 

There is uncertainty regarding the rate at which fluroxypyr (ai) is converted from fluroxypyrMHE (applied product), or even if this has any practical implications for the risk assessment. 

Under field conditions it is likely that most of the MHE will convert to the active ingredient 

(fluroxypyr acid) in the course of several days or weeks. Both terrestrial and aquatic 

exposure models assume exposure to both fluroxypyr and fluroxypyr-MHE,. Although there 

are differences in physical/chemical characteristics that may presumably influence mobility 

and fate of these 2 forms, for the purpose of aquatic modeling there was no significant 

distinction between model results using the input parameters (where different) for the MHE 

vs. the acid form; therefore, a combined residues approach was used. 

Chronic aquatic toxicological studies are lacking. However, because of the relatively rapid 

degradation of fluroxypyr in aquatic environments (5-14 days), long-term exposure to 

fluroxypyr in surface water is considered unlikely; thus, these studies may not be necessary. 

This is further supported by the lack of detection of fluroxypyr in (foreign) targeted water 

monitoring studies. Low acute toxicity and lack of chronic risk concerns (based on the 

available terrestrial animal studies) also indicate that chronic aquatic risk should be very low. 

There are currently no available registrant-supplied chronic avian toxicological studies for 

fluroxypyr. However, the Agency believes this risk is likely low, based upon absence of 

chronic avian risk from fluroxypyr-MHE and lack of chronic risk to mammals from 

fluroxypyr. Thus, avian chronic toxicological studies for fluroxypyr may not be necessary. 

b) Risk Characterization Method (Risk quotients and levels of concern) 

Risk characterization integrates exposure and measure of effects data to evaluate the 

likelihood of adverse effects. For a screening level risk analysis, the Agency accomplishes 

this integration using a risk index approach, the risk quotient method. Risk quotients (RQs) 

are calculated by dividing estimates of exposure (EEC) by acute and chronic measures of 

effect. 

RQ = EXPOSURE / MEASURE OF EFFECT 

22 
RQs are then compared to levels of concern (LOCs) to indicate the potential risk to nontarget, listed (endangered or threatened), and non-listed organisms. The LOCs are 

presumptive risk values; a RQ that exceeds the LOC has a presumed risk to non-target 

organisms. LOCs currently address the following categories of presumed risk: 

$ acute - potential for acute risk is high and regulatory action beyond restricted 

use classification may be warranted - $ acute restricted - the potential for acute risk is high, but may be mitigated 

through restricted use classification 

$ acute listed species - threatened and endangered species may be adversely 

affected 

$ chronic risk - the potential for chronic risk is high and regulatory action may 

be warranted. 

The measures of effect used in the acute and chronic risk quotients are derived fiom required 

laboratory toxicity studies identified in section II.B.3. Table 5 lists the LOC value by 

taxonomic group associated with a given risk presumption and the specific associated RQ 

calculation. Each of the taxonomic groups corresponds to the risk hypotheses identified for 

this assessment in section 1I.D. 

Table 5. Risk presumption LOC values and associated formulas for RQ calculations 

Risk Presumption RQ LOC 

Birds and Wild Mammals 

Acute ~isk' 

Acute Restricted use1 

Acute Listed species1 

Chronic ~isk' 

EEC~ (ppm) 1 LCSO (ppm) or EEC (mglkg-bwld) I LDSO (mglkg-bwld) 

EEC (ppm) I LCs0 (ppm) or EEC (mg/kg-bwld) 1 LDSO (mglkg-bwld) 

EEC (ppm) 1 LCS0 (ppm) or EEC (mg/kg-bwld) I LD50 (mglkg-bwld) 

EEC (ppm) 1 NOAEC (ppm) or EEC (mglkg-bwld) I NOAEL (mglkgbwld) 

0.5 

0.2 

0.1 

1 .O 

Aquatic Animals 

Acute Risk 

Acute Restricted Use 

Acute Listed Species 

Chronic Risk 

EEC (PP~) (LC50 (ppm) or EC~o bpm)) 

EEC (PP~) (LCso (ppm) or ECso (PP~)) 

EEC bpm) LC50 (PP~) orECso 

EEC (ppm) 1 NOAEC (ppm) 

0.5 

0.1 

0.05 

1.0 

Terrestrial and Plants Inhabiting Semi-Aquatic Areas 

Acute Risk 

Acute Listed Use 

EEC (lbs ai/A) 1 EC2, (lbs ai/A) 

EEC (lbs ai/A) 1 (ECoS or NOAEC (lbs ai/A)) 

1 .O 

1 .O 
Risk Presumption I RQ I LOC 

I Auuatic Plants 1 

.- - , 

dietary level from the laboratory study is adjusted for the body weight of representative exposed mammals or 

birds or compare normalized dose values in terms of milligram of ai per kilogram body weight per day (mglkgbwid). 

2 EEC = estimate environmental concentration 

Acute Risk 

Acute Listed Species 

Screening level models used for deriving EECs to address each of the risk hypotheses by the 

appropriate RQ method and LOC comparison, as defined above, are described in the section 

below in the fate and exposure analysis plan. The fate and exposure analysis plan also 

identifies the type of data required to support model inputs and provides the strategy for 

identifying and using other sources of exposure information to characterize exposure and 

model results. The analysis plan section on effects describes the selection process for the 

measure of effect value to be used in RQ calculations in a screening level risk assessment. 

2. Measures to Evaluate Risk Hypotheses and Conceptual Model 

' For mammals and birds, one can either calculate based on concentration of the ai in the diet (ppm) where the 

EEC (PP~) 1 ECso bpm) 

EEC (ppm) / (ECo5 or NOAEC (ppm)) 

a) Measures of Exposure 

1 .O 

1 .O 

Methods used to determine exposure concentrations of a pesticide are dependent on its 

environmental fate and physicochemical properties, the application method, and the presence 

of reliable monitoring data that are considered representative of the proposed use sites. 

Initial factors considered for the exposure assessment are provided in Table 6 below. 

Table 6. Factors that may affect the exposure of fluroxypyr 

Consideration 

Monitoring data 

Degradation 

Fluroxypyr Specific data 

No targeted data from U.S. 

Targeted monitoring from 

other countries revealed no 

detections 

Fairly rapid degradation, 

especially in aquatic and 

high-pH environments. 

Conclusion 

Insufficient data available to 

use in risk assessment. Lack 

of detects in foreign studies 

indicate probable low aquatic 

risk. 

Little likelihood for longterm high-exposure 

conditions. Greatest exposure 

risk following application 

and decreasing rapidly 

thereafter. 
Exposure in Terrestrial Systems 

Sorption to soil 

Bioconcentration Factor 

(BCF) 

Application method 

For birds and mammals, the screening assessment of the terrestrial dietary exposure route for 

uptake of pesticide active ingredient assumes that organisms are exposed to a single pesticide 

residue level for both acute and chronic exposure estimates. EECs in wildlife food items 

focus on quantifying possible dietary ingestion of residues on vegetative matter and insects 

on the treated field as the highest residue level that will occur from fluroxypyr MHE use per 

the label. EFED uses different EECs for a variety of food substrates. Those food substrates 

are: short grass, tall grass, broadleaf plantslsmal1 insects, and hits/pods/seeds/large insects. 

The EECs are based on a nomogram that relates food item residues to pesticide application 

rate (Hoerger and Kenaga (1 972) as modified by Fletcher et al. (1 994)). The maximum 

Kenaga value represents residue levels present immediately following chemical application 

(day zero). The mean Kenaga value represents mean residue levels present (considering day 

0 and day 100 residue levels). The first tier nomogram uses the maximum predicted residues 

immediately following application. The residue concentrations are converted to a daily oral 

dose based on fractions of body weight consumed daily as estimated from mammalian 

allometric relationships in EPA's Wildlife Exposure Factors Handbook (1 996). The EECs for 

birds are adjusted based on food in-take and body weight differences, so that they are 

comparable for a given weight class of animal. In all screening-level assessments, the 

organisms are assumed to consume 100% of their diet as one food type. EFED also used the 

T-REX model to estimate (1) EECs for different food items for birds and mammals and (2) 

doseldiet based risk to birds as well as dose based risk to mammals. These input parameters 

may be seen in Appendix B. 

EFED used the TERRPLANT model to estimate (1) EECs from a single application only and 

(2) risk from runoff to monocot and dicot terrestrial plants in areas adjacent to the treated 

field (sheet runoff), wetland areas (channelized runoff), and from spray drift. Input 

parameters and assumptions from the model are included in Appendix B.. 

Mobile, according to Koc 

value(s) (FA0 classification) 

< 100 (fish = 26) 

Spray (aerial and ground). 

Exposure in Aquatic Systems 

Rapid degradation limits real 

mobility. 

Low bioaccumulation 

potential. 

Possibility for off-site 

contamination resulting from 

spray drift. 

At the screening risk assessment level for aquatic organisms, such as plants, fish, aquaticphase amphibians, and invertebrates, computer simulation models are used to estimate acute 

(annual instantaneous peak) and chronic (21 and 60 day weighted average annual peaks for 

25 
aquatic invertebrates and fish, respectively) residue levels of the dissolved pesticide active 

ingredient in surface water and sediment pore water and in bulk sediment fi-om runoff and 

spray drift. These models calculate EECs in surface water and sediment using environmental 

fate data for fluroxypyr. Monitoring data, if available, may also be used to determine EECs 

or to support the model's exposure estimates. PRZM-EXAMS, as documented at 

www.epa.govloppefedl/modelslwater/index.htm, is the model used to simulate the fate and 

transport of fluroxypyr MHE fiom a treated field to and into a receiving water body adjacent 

to the treated field. Cropping patterns, soil properties, and weather input data for the 

simulation modeling have been standardized for a number of crops, referred to as crop 

scenarios, to provide high-end estimates of runoff and soil erosion representative of the 

primary growing area for a given crop. The quality control checked crop scenarios and 

associated meteorological files available for use in a risk analysis are also found at the same 

web address under the "PRZM crop scenario metadata" (download WPD file 1468KB). 

b) Measures of Effects 

Each assessment endpoint requires one or more measures of ecological effect, which are 

defined as changes in the attributes of an assessment endpoint itself or changes in a surrogate 

entity or attribute in response to pesticide exposure (Table 4). Ecological measurement 

endpoints for the screening level risk assessment are based on a suite of registrant-submitted 

toxicity studies performed on a limited number of organisms in the following broad 

groupings : 

Birds (typical test species are mallard duck and bobwhite quail) which are also used 

as surrogate taxa for terrestrial-phase amphibians and reptiles. 

Mammals (typical test species are the laboratory rat or mouse) 

Freshwater fish (typical test species are the bluegill sunfish and rainbow trout) which 

are also used as a surrogate for aquatic-phase amphibians 

Freshwater invertebrates (typical test species is the water flea - Daphnia magna) 

Estuarinelrnarine fish (typical test species is the sheepshead minnow or Atlantic 

silverside) 

Estuarinelmarine invertebrates (typical test species are the Eastern oyster and mysid 

shrimp) 

Beneficial insects (typical test species is the domestic honey bee) 

Terrestrial plants (typical test species are corn, onion, ryegrass, wheat, buckwheat, 

cucumber, soybean, sunflower, tomato, and turnip) 

Algae and aquatic plants (typical test species are AnabaenaJlos-aquae, Selenastrum 

capricornutum, Scenedesmus subspicatus, Chlorella vulgaris for algae; Skeletonema 

costatum and Navicula seminulum for diatoms; and Lemna gibba for vascular plants) 
The acute contact LD50 value is used as a measure of effect for beneficial insects. The 

typical test species used as a surrogate for all beneficial insects is the domestic honey bee. 

The screening assessment endpoint for plants in terrestrial and semi-aquatic environments is 

the perpetuation of populations of non-target species (both crop and non-crop species). 

Measures of effect include the concentration of the pesticide formulation that would cause a 

25 percent reduction in seedling emergence (EC25) and the concentration of the pesticide that 

would cause a 25 percent inhibition (EC25) in vegetative vigor. Although it is recognized that 

the seedling emergence and vegetative vigor endpoints may not address all plant life cycle 

components, it is assumed that impacts at emergence and during active growth may impact 

individual competitive ability and reproductive success. Algae and aquatic plant measures of 

effect are the growth and biomass 5-day (7-day for duckweed) EC50. Because the proposed 

labeled use is not for direct application to aquatic systems, the measures of effect desired for 

algae and aquatic plants are for the technical grade active ingredient form of fluroxypyr. 

Measures of effect data submitted by the registrant are identified in Section I1 B and will be 

reviewed for use in RQ calculations. Measures of effect for which data are not available, are 

discussed as data gaps. The ability to evaluate risk is identified in both the Toxicity 

Assessment Section and the Risk Characterization Section. For this screening assessment, the 

most sensitive measure of effect for each surrogate taxa group (i.e., freshwater fish and 

invertebrates, estuarine/marine fish and invertebrates, aquatic plants, terrestrial plants, birds, 

and mammals) will be used in RQ oalculations. 

The same measures of effect used for non-listed species are used for listed species= 

taxonomic groups except the measures of effect for terrestrial plants, algae, and aquatic 

plants. For terrestrial plants, the measure of effect desired is the ECo5 or NOAEC for 

vegetative vigor and the ECo5 or NOAEC for seedling emergence. The ECo5 for growth or 

biomass is used for algae and aquatic plants. 
111. ANALYSIS 

A. Exposure Characterization 

1. Environmental Fate and Transport 

a. Degradation and Metabolism 

Degradation of fluroxypyr-MHE and fluroxypyr in environmental fate laboratory studies 

occurs through base-catalyzed hydrolysis and microbial-mediated metabolism under aerobic 

conditions. In sterilized buffered water, fluroxypyr-MHE hydrolyzed to the fluroxypyr with 

half-lives of 3 and 454 days at pH 9 and 7, respectively. Hydrolysis of fluroxypyr-MHE was 

not observed in the acidic test system at pH 5. No hydrolysis of Fluroxypyr was observed at 

pH 5,7, or 9. In the aerobic soil metabolism study, both fluroxypyr-MHE and fluroxypyr 

transform rapidly. Microbial degradation of fluroxypyr-MHE appears to follow a biphasic 

degradation pattern with an initial first-order half-life of 1 to 3 weeks in four soils. 

Degradation of fluroxypyr-MHE yields fluroxypyr (the herbicidal agent), 4-amino-3,5- 

dichloro-6-fluoro-pyridin-2-01 (pyridinol metabolite), 4-amino-3,5-dichloro-6-fluoro-2- 

methoxypyridine (methoxypyridine metabolite) and C02. Fluroxypyr then degraded with 

calculated half-lives of 12,23, 12, and 7 days. The rate of metabolism decreased significantly 

after 2 months. 

Fluroxypyr-MHE and fluroxypyr degrade rapidly in the aerobic aquatic environment (tin -14 

days). The major degradate 3-chloropyridinol, was present in the water phase at maximum of 

18% of the applied radioactivity at 4 months posttreatment. The major degradate 

dichloropyridinol, was present in the water phase at maximum of 44% of the applied 

radioactivity at 4 weeks posttreatment. These degradates are significantly less toxic than 

either fluroxypyr or fluroxypyr-MHE, and are not included as part of 'total toxic residues' in 

this assessment. Fluroxypyr-MHE and fluroxypyr degrade rapidly in the anaerobic aquatic 

environment (tIl2 -8 days). Major degradates were 3-chloropyridinol and dichloropyridinol. 

Fluroxypyr-MHE and fluroxypyr do not degrade by photolysis in aqueous environments or in 

soil. 

b. Transport and Mobility 

Volatility is not a significant route of dissipation. Fluroxypyr is considered to be mobile 

based on Freundlich Lds values ranging from 0.1 1 - 1.9 mllg in four test soils (silt loam, sandy 

loam, loam, and silty clay textures). Major degradate (fluroxypyr) is not expected to 

bioaccumulate since it will be in an ionic form in water. 

c. Field Studies 

Field dissipation studies conducted in Oklahoma (MRID 45204201), North Carolina (MRID 

44896702) and Missouri (MRID 45204202) indicate a field dissipation half-life of 5-8 days. 

The primary dissipation route appeared to be transformation. 

28 
d. Bioaccumulation 

According to the Staranem Material Safety Data Sheet (Dow AgroSciences), 

bioconcentration potential is low (BCF < 100); a BCF of 26 is cited for fish. 

2. Measures of Aquatic Exposure 

a. Aquatic Exposure Modeling 

The PRZM-EXAMS model was used to estimate the surface water concentrations for 

fluroxypyr from the proposed new uses. Input values for this model are listed in Table 7. 

Values for the fluroxypyr acid form were used for molecular weight, vapor pressure, 

solubility, and hydrolysis, as this is the active ingredient degradation product for which these 

uses are intended. All fateltransport parameters in Table 7 are for total toxic residues (MHE 

and acid forms). Regardless, modeling acid-only versus MHE-only forms yielded 

insignificant differences in predicted Environmental Exposure Concentrations (EECs) for 

EFED baseline-assessment models. 

'TX Sorghum' was used as a surrogate scenario for millet because sorghum is very similar to 

millet in terms of crop type and production methods, and is grown predominantly in the 

southern plains region of the U.S. (Texas being one of the major producers of millet). Below 

(Table 8) are the model results for predicted surface water concentrations (using the PRZMEXAMS model). 

I I pH 7 = Stable I MRID 40244539 I 

Table 7. Fluroxypyr Input Parameters for PRZM-EXAMS Model 

PARAMETER: ' 

Molecular Weight 

Henry's Law Constant 

Vapor Pressure 

Solubility 

Hydrolysis Half-life 

Aqueous Photolysis Half-life 

Water Half-life (aerobic) 

Benthic Half-life (anaerobic) 

Soil Half-life (aerobic) 

KC 

Application Rate: Sorghum 

Application Method: Sorghum 

Number of Applications / Intervals: 

Sorghum 

Application Rate: Pome Fruit 

VALUE: 

255 glmol 

NIA 

9.4*10-~ mm Hg 

7950 mg/L 

pH 5 = Stable 

SOURCE: 

OPPIPesticide Fact Sheetl1998 

STARANEB Material Safety Data Sheet 

STARANEB Material Safety Data Sheet 

pH 9 = Stable 

Stable 

42 days 

24 days 

14 days 

68 

0.125 lb aUA 

Aerial Spray 

2 per year 1 14 days 

0.5 lb aUA 

MRID 44080342 

MRID 44080345 - 3X single value of 14 days 

MRID 44080344 - 3X single value of 8 days 

MRID 42 1373 17 - median value for 4 soil types 

MRID 42 1373 19 - average of 4 values &om 4 

different soils 

Label 

Label 

Label 

Label 
The estimated peak, 4-day, 21 -day, 60-day, and 90-day concentrations of fluroxypyr in 

surface water predicted by PRZM-EXAMS are presented in Table 8, below. Detailed 

PRZM-EXAMS model output files are presented in Appendix E 

Application Method: Pome Fruit 

Number of Applications 1 Intervals: 

Pome Fruit 

Table 8. Tier 2 (PRZM-EXAMS) Estimated Environmental Concentrations (EEC) of 

Ground Spray 

1 per year 

b. Water Monitoring Data 

Label 

Label 

Fluroxypyr in Standard Farm Pond from Use on Pome Fruit and Millet. 

There is insufficient targeted monitoring data for fluroxypyr in the U.S. to allow for 

evaluation of potential exposure in aquatic environments. However, there have been targeted 

studies in other countries. A targeted monitoring study conducted in Australia (Waugh and 

Padovan, 2004) did not detect any fluroxypyr residues in sediments, ground water, or surface 

waters, even though fluroxypyr was one of the most heavily applied chemicals of the 33 

measured (most of the other chemicals had some detections). Similarly, a Norwegian. study 

(Haarstad and Ludvigsen, 2007) did not detect fluroxypyr in any ground water samples 

obtained during the 9 years of monitoring; fkequent detections of other chemicals also 

applied to nearby fields frequently yielded positive results, indicating that some compounds 

(other than fluroxypyr) were indeed entering ground water. Nevertheless, considering the 

lack of robust monitoring for fluroxypyr in the U.S. the Agency has instead used model 

results to make fate and effects determinations. 

CROP: 

Pome fruit 

Millet 

3. Measures of Terrestrial Exposure 

a. Dietary Residues 

Peak 

(ug/L) 

9.18 

7.64 

The predicted maximum residues of fluroxypyr MHE that may be expected to occur on 

selected avian food items immediately following application are presented in Table 9. 

Maximum EECs were calculated based on maximum label use rate for proposed new uses. 

96 hr 

(ug/L) 

7.34 

5.85 

21 Day 

(ug/L) 

3.45 

2.84 

60 Day 

(ug/L) 

1.36 

1.11 

90 Day 

(ug.'L) 

0.92 

0.74 

Yearly 

0.23 

0.18 
b. Exposure Modeling for Non-Target Plants 

Table 9. Estimated environmental concentrations of fluroxypyr MHE 

on avian and mammalian food items. 

Terrestrial and semi-aquatic plant exposure characterization employs runoff and spray drift 

scenarios contained in OPP's Terrplant model. The TerrPlant model is described in fbrther 

detail in Appendix B. Exposure calculations are based on a pesticide's water solubility and 

the amount of pesticide present on the surface soil within the first inch of depth. For dry 

areas, the loading of pesticide active ingredient from runoff to an adjacent non-target area is 

assumed to occur from one acre of treatment to one acre of non-target area; for semi-aquatic 

(wetland) areas, runoff is considered to occur from a larger source area with active ingredient 

loading originating from 10 acres of treated area to a single acre of non-target wetland. 

Default spray drift assumptions are 1% for ground applications and 5% for aerial, airblast, 

forced air, and chernigation applications. Terrestrial plant EECs for non-granular 

formulations are summarized in Table 10. EECs for granular formulations are not presented 

because the label does not specify granular formulations for fluroxypyr MHE. It should be 

noted that Terrplant modeling was conducted for 1 application of the maximum single 

application rate for each crop. 

Crop 

Pome 

millet 

c. Spray Drift Analysis 

APPLICATIONS: 

Rate (Ibs./acre) / 

Number / Interval 

0.51110 

0.12512114 

Table 10. EECs for Fluroxypyr MHE application at maximum use rate for uses on pome 

fruit and millet. Units in Ibs ailacre. 

AgDrift version 2.01 was used to estimate the exposure of downwind terrestrial and aquatic 

plants to fluroxypyr MHE from the proposed new uses. AgDrift is a computer model 

developed by the Spray Drift Task Force to evaluate off-site deposition of pesticides applied 

by aerial, ground, and orchard blast spraying techniques, and for estimation of buffer zones 

Description 

Runoff to dry areas 

Runoff to semi-aquatic areas 

Spray drift 

Total for dry areas 

Total for semi-aquatic areas 

Estimated Environmental Concentration (EEC) (ppm) 

Short grass 

120 

120 

Pome fruit EEC Millet EEC 

0.005 0.001 25 

0.05 0.01 25 

0.005 0.001 25 

0.01 0.0025 

0.055 0.01 375 

I 

Tall grass 

5 5 

24.17 

Broadleaf plantslsmall 

insects 

67.50 

29.66 

Fruits/pods/ 

large insects 

7.5 

3.30 
needed to protect sensitive aquatic and terrestrial species from undesired exposures. For this 

assessment, AgDrift may be used to calculate the distance downwind of a treated field that 

would be needed to reduce exposure to below a no-observed-effect-level for terrestrial and 

aquatic plants. 

C. Ecological Effects Characterization 

In screening-level ecological risk assessments, the effects characterization section describes 

the types of effects on aquatic and terrestrial organisms, which result fi-om pesticide 

exposure. This characterization is based on registrant-submitted studies that describe 

information regarding acute and chronic effects toxicity for various aquatic and terrestrial 

animals and plants. Appendix C summarizes the results of the registrant-submitted toxicity 

studies on fluroxypyr used to characterize effects for this risk assessment. 

The toxicity testing reported in this section is not an exhaustive survey of all species of birds, 

mammals, or aquatic organisms. Only a few surrogate species for both freshwater fish and 

birds are used to represent all freshwater fish (2000+) and bird (680+) species in the United 

States. For mammals, acute studies are usually limited to the Norway Rat or the House 

Mouse. Testing for reptiles and amphibians are not required. The risk assessment assumes 

that conclusions drawn from avian toxicity studies are applicable to reptiles. Similarly, 

conclusions drawn from studies conducted with fish are assumed applicable to amphibians. 

In general, categories of acute toxicity ranging from "practically nontoxic" to "very highly 

toxic" have been established for aquatic organisms (based on LCs0 values), terrestrial 

mammals (based on LDS0 values), avian species (based on LCs0 values), and non-target 

insects (based on LDSo values for honey bees) (U.S. EPA 2001). These categories are 

presented in Appendix D. 

1. Aquatic Effects Characterization 

The most sensitive acute toxicity values associated with exposure of freshwater species to 

fluroxypy MHE and fluroxypyr are summarized in Table 11. A more detailed summary of 

the aquatic toxicity data available to characterize risks associated with fluroxypyr MHE and 

fluroxypyr exposure is given in Appendix A. RQ calculations for aquatic organisms will be 

done based the most sensitive fluroxypyr MHE and fluroxypyr toxicity endpoints among 

fish, aquatic invertebrate, and aquatic plants. For example the freshwater fish acute RQ will 

be done based on the fluroxpyr MHE fish LCs0 of 13.2 ppm ai because it is more sensitive 

than the most sensitive fluroxypyr freshwater fish acute toxicity LCso (Table 12). 
The registrant has submitted toxicity studies for aquatic plants, fish and aquatic invertebrates 

for fluroxypyr MHE and fluroxypyr. The following is a brief discussion of the studies 

submitted. A more detailed summary of the aquatic toxicity data available to characterize 

risks associated with fluroxypyr MHE and fluroxypyr exposure is given in Appendix A. 

Table 11. Aquatic organism toxicity characterizations for fIuroxypyr MHE and its Herbicidal Degradate 

a. Aquatic Animals 

Fluroxypyr 

Taxonomic Group 

Freshwater Fish 

Freshwater Fish 

EstuarineMarine Fish 

EstuarineMarine Fish 

Freshwater Invertebrates 

Freshwater Invertebrates 

Marine 

Estuarine Invertebrates 

Marine 

Estuarine Invertebrates 

Aquatic nonvascular 

plants 

Aquatic nonvascular 

plants 

Aquatic vascular plants 

Aquatic vascular plants 

Note 1 : This item is not 

(1) Acute Effects 

Freshwater Fish 

aquatic plant toxicity endpoints. 

Note 2: This item is not applicable (NA) because there are no guideline aquatic plant chronic toxicity studies. 

Chemical 

Fluroxypyr 

Fluroxypy MHE 

Fluroxypyr 

Fluroxypyr MHE 

Fluroxypyr 

Fluroxypyr MHE 

Fluroxypyr 

Fluroxypyr MHE 

Fluroxypyr 

Fluroxypyr MHE 

Fluroxypyr 

Fluroxypyr MHE 

applicable (NA) because 

Acute Toxicity 

The registrant submitted 3 acceptable freshwater fish acute toxicity tests for fluroxypyr 

including a rainbow trout study, a bluegill sunfish study, and a golden orfe study. The LCsa 

Principal Acute 

Toxicity Endpoint 

LC50 = 14.3 ppm ai 

= 13.2 ppm ai 

No Data Available 

> 0.087 ppm ai 

EC50 > 100 ppm ai 

EC50 > 0.109 pprn ai 

51 ppm ai 

0.068ppmai 

EC50 > 100 ppm ai 

0.29 ppm ai 

No Data Available 

> 2.3 ppm ai 

the Agency does not 

Acute Toxicity 

Categories 

Slightly toxic 

Slightly toxic 

NA 

Not determined 

Practically 

nontoxic 

Not determined 

Slightly toxic 

Veryhighly 

toxic 

NA ' 

NA ' 

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

NA ' 

assign acute toxicity 

Principal 

Chronic Toxicity 

Endpoint 

No Data 

Available 

No Data 

Available 

No Data 

Available 

No Data 

Available 

No Data 

Available 

No Data 

Available 

No Data 

Available 

No Data 

Available 

NA 

NA 

NA 

NA 

characterizations to 
toxicities for these studies ranged from 14.3 pprn ai - > 100 pprn ai. Thus, fluroxypyr is 

slightly to practically nontoxic to freshwater fish. The LC50 of 13.2 pprn ai (table 12) will be 

used to calculate the acute risk quotients for freshwater fish because it is the most sensitive 

toxicity freshwater fish acute toxicity endpoint among the available data for fluroxypyr 

MHE and fluroxypyr. The registrant submitted 2 freshwater fish acute toxicity tests for 

fluroxypyr MHE including an inland silverside and bluegill sunfish. The LCs0 toxicities for 

these studies were 40 pprn and > 0.63 pprn respectively. Fluroxypyr MHE is slightly toxic to 

freshwater fish. 

Freshwater Invertebrates 

Acute toxicity 

The registrant submitted two acceptable freshwater invertebrate studies evaluating the acute 

toxicity of fluroxypyr on Daphnia magna and two acceptable freshwater invertebrates studies 

testing the acute toxicity of fluroxypyr MHE. The ECsO toxicity values were greater than the 

highest values tested (up to > 100 pprn ai) for all the studies. Based on the results of these 

studies fluroxypyr is practically nontoxic to freshwater invertebrates. RQs will not be 

calculated for freshwater invertebrates because the available toxicity studies demonstrated 

that fluroxypyr and fluroxypyr MHE is practically nontoxic to freshwater invertebrates. 

MarineJEstuarine Fish 

Acute Toxicity 

The registrant submitted two marinelestuarine fish toxicity studies testing the acute toxicity 

of fluroxypyr MHE on Atlantic silverside and sheepshead minnow. The study testing 

Atlantic silverside was deemed supplemental. The study testing sheepshead minnow was 

deemed acceptable. The LC50 toxicity values of these studies were not determined because 

the LCso was higher than the hghest concentrations tested which were 0.188 pprn ai and 

0.087 pprn ai. respectively. 

Marine Estuarine Invertebrates 

Acute toxicity 

The registrant submitted two acceptable marinelestuarine invertebrate studies testing 

fluroxypyr acute toxicity on the eastern oyster and grass shrimp. The ECS0 toxicity values for 

these studies ranged from 5 1 pprn ai - > 120 pprn ai. These results demonstrate that 

fluroxypyr is slightly to practically nontoxic to marinelestuarine invertebrates. The registrant 

has also submitted four marinelestuarine studies testing fluroxypyr MHE acute toxicity on 

the eastern oyster, grass shrimp, and pink shrimp. Two of the studies were deemed 

supplemental (one testing eastern oyster and the other testing pink shrimp) and the two other 

studies (one testing eastern oyster and the other testing grass shrimp) was deemed acceptable. 

The supplemental study testing eastern oyster MRID 440803 10 was the only study that 

34 
produced an ECSo value. This value was 0.068 ppm ai The results of this study deemed 

fluroxypyr MHE as very highly toxic to marinelestuarine invertebrates. RQs for marine 

estuarine invertebrates will be calculated using the fluroxypyr MHE most sensitive marine 

estuarine invertebrate acute toxicity value of 0.068 ppm a.i 

(2) Chronic toxicity 

No chronic toxicity tests on aquatic organisms have been submitted by the registrant. 

(3) Sublethal Effects 

None of the available data report any sublethal toxic effects on aquatic organisms. 

(4) Field Studies 

No field studies with aquatic animals are available. 

b. Aquatic Plants 

The registrant submitted several acceptable aquatic plant toxicity studies for fluroxypyr MHE 

and many of it degradates including fluroxypyr, fluroxypyr MHE, 4-amino-3-5,5-dichloro6-fluoro-2-pyridinol, 4-arnino-3,5-dichloro-6-fluoro-2-methoxypyridine. Appendix A 

provides further details of all the aquatic plant toxicity studies submitted. 

2. Terrestrial Effects Characterization 

The most sensitive acute and chronic toxicity values associated with exposure of terrestrial 

species to fluroxypyr MHE and fluroxypyr are summarized in Table 12. A more detailed 

summary of the terrestrial toxicity data available to characterize risks associated with 

fluroxypyr MHE and fluroxypyr is given in Appendix A. 

Table 12. Fluroxypyr MHE and Fluroxypyr Most Sensitive Toxicity Values for Terrestrial Organisms. 

Reference 

(Classification) 

Exposure 

Scenario 

Exposure 

Duration 

Species 

Mammals 

Most Sensitive Toxicity Value 

MRID 44080329 

MRD 44080321 

Acute 

(Dosebased) 

Chronic 

(Dosebased) 

Oral 

Dose 

2 generation 

Rat 

R~~ 

LDro 790 rng ailkg (Fluronypyr MHE) 

NOAEC = 10000 ppm ai (Fluroxypyr MHE) 
a. Terrestrial Animals 

Birds 

The EPA examines two endpoints, the LD50 and LC50, when assessing the acute risk to birds 

and mammals, and generally uses the endpoint that is most sensitive or which represents the 

scenario best. The LD50 may give a better indication of inherent toxicity than the LCso in 

cases where a pesticide is not too palatable, and animals simply avoid eating the resource. 

The LDso may also be more representative of animals that gorge when feeding. 

LDso > 2000 mg ailkg (Fluroxypyr) 

LCSo > 5620 ppm ai(F1uroxypyr and 

Fluroxypyr MHE) 

LOAEC = 500 ppm ai 

NOAEC = 250 ppm a1 

(Fluroxypyr MHE) 

Single oral 

dose 

days 

N,A 

Acute 

(Dosebased) 

Acute 

(Dietarybased) 

Chronic 

(Dietarybased) 

MRID 40244514 and 

MRID 402445 15 

MRTDs 

42137302 and 

42137301 

MRID 42137304 

Northern 

bobwhite 

quail and 

Mallard 

Duck 

Mallard 

Duck 

Mallard 

Duck 

Plant ToxicityMRID 44080335 sing1e application 

single 

application 

Cucumber 

Onion 

Tier I1 

seedling 

emergenc 

Plant Toxicity 

NOAEC = 0.03 1 Ibs. ailacre 

EC25 = 0.075 lbs. aiiacre 

(Fluroxypyr MHE) 

NOAEC = 0.124 lbs. adacre 

EC25 = > 0.25 Ibs. ailacre 

(Fluroxypyr MHE) 

Dicot 

Monocot 

MRID 44080335 

single 

application 

single 

application 

tomato 

and 

sunflower 

Onion 

Vegetative 

Vigor 

Non-target Beneficial Insects 

NOAEC = 0.001 Ibs. ailacre 

EC25 = 0.004 lbs. ailacre 

NOAEC = 0.062 lbs. aiiacre. 

EC25 = 0.124 lbs. ailacre 

(Fluroxypyr MHE) 

Dicot 

Monocot 

MRID 42137314 > 25 uglbee ai 

(FluroxYPyr) 

96 hrs Acute Contact 

Toxicity Honey bee 

@pis mellifera) 
The registrant submitted studies testing fluroxypyr MHE and fluroxypyr on birds, bees, and 

mammals. 

1) Acute Effects 

Birds 

The registrant submitted studies submitted two avian acute oral toxicity studies testing 

fluroxypyr on mallard duck and bobwhite quail. One of the studies was deemed acceptable, 

and the other study was deemed supplemental. Both studies resulted in LDs0 values greater 

than 2000 mglkg. Thus, based on the results of this study fluroxypyr MHE and fluroxypyr 

are practically nontoxic to birds on an acute oral dose basis. 

The registrant also submitted two acceptable avian dietary acute dietary studies testing 

fluroxypyr on bobwhite quail and one acceptable avian acute dietary study testing fluroxypyr 

MHE on mallard duck. All these studies demonstrated that fluroxypyr and fluroxypyr MHE 

were practically nontoxic to birds (LC50 > 5000 pprn ai). 

Mammals 

There is one registrant submitted acute oral MRID study in rats for fluroxypyr MHE (MRID 

44080321). A LDso of 3 160 mgkg (practically nontoxic to mammals) was obtained in the 

study. 

2) Chronic Effects 

Birds 

There are two acceptable registrant submitted guideline avian reproductive toxicity studies 

testing Fluroxypyr MHE on northern bobwhite quail and mallard duck The NOEAC for the 

studies were 5620 pprn ai and 250 pprn ai respectively. There were no endpoints 

significantly affected in the northern bobwhite quail study at the highest concentrations tested 

and the endpoints affected in the mallard duck included egg yolk peritonitis in hens at a 

NOEAL of 250 ppm. 

Mammals 

The registrant submitted one reproductive toxicity study 0x1 rats. The study results yielded a 

parental toxicity NOAEL of 1000 ppm, a reproductive NOEAL of 7500 ppm, and a pup . 

survival and weight gain NOEAL of 10,000 pprn (MRID 44080321). 

37 
3) Sublethal Effects 

None of the terrestrial animal acute toxicity studies report any significant sublethal effects. 

4) Field Studies 

No field studies were submitted to the Agency. 

b. Terrestrial Plants 

Terrestrial Tier I1 seedling emergence and vegetative vigor studies are required for all low 

dose herbicides (those with the maximum use rate < 0.5 lbs ai /A) and any pesticide showing 

a negative response equal to or greater than 25% in Tier I tests. 

The available terrestrial plant toxicity data include acceptable registrant submitted tier I1 

vegetative vigor and tier I1 seedling emergence studies for both the formulated product of 

fluroxypyr MHE and fluroxypyr. 

Results of the acceptable Tier I1 seedling emergence toxicity study on fluroxypyr MHE 

demonstrated that the most sensitive tested species was cucumber. The EC25 and the NOEC 

for cucumber are 0.075 and 0.03 1 lb ai/A. The results of this study also demonstrated that 

fluroxypyr MHE is generally not toxic to monocots at 0.25 lb ai/A. 

The results of the acceptable tier I1 vegetative vigor toxicity testing on a formulated product 

of fluroxypyr MHE showed the most sensitive species was cotton. Based on the most 

sensitive parameter, phytotoxic symptoms, 25% inhibition was predicted to occur at a dose of 

0.0012 lb ai/A. The no observed effect level (NOEL) for cotton was 0.0010 lb ai/A. 

The tier I1 seedling emergence study testing fluroxypyr (which was deemed as supplemental) 

showed that the most sensitive of the six species tested is cotton, which has an EC25 of 0.025 

lb ai/A. This is approximately 5 times lower than the cotton EC25 for fluroxypyr MHE. 

The tier I1 vegetative vigor study testing fluroxypy (which was deemed as supplemental) 

suggested that fluroxypyr acid is more toxic to vegetative vigor than fluroxypyr MHE. The 

most sensitive of the six species in the fluroxypyr acid study is soybean which produced an 

EC25 of 0.00067 lb ai/A. This is approximately 12 times lower than the soybean EC25 for 

fluroxypyr MHE. 
IV. RISK CHARACTERIZATION 

Risk characterization is the integration of exposure and effects characterization to determine 

the ecological risk from the use of fluroxypyr MHE and the likelihood of effects on aquatic 

life, wildlife, and plants based on varying pesticide-use scenarios. The risk characterization 

provides estimations and descriptions of the risk; articulates risk assessment assumptions, 

limitations, and uncertainties; synthesizes an overall conclusion; and provides the risk 

managers with information to make regulatory decisions. 

A. Risk Estimation - Integration of Exposure and Effects Data 

Results of the exposure and toxicity effects data are used to evaluate the likelihood of 

adverse ecological effects on non-target species. For the screening risk assessment of 

fluroxypyr MHE and fluroxypyr, the RQ method as described in Section 1I.E is used to 

compare exposure and measured effects data. The RQs are compared to the Agency=s 

LOCs. These LOCs are listed in Section 1I.E and are the Agency=s interpretive policy to 

analyze potential risk to non-target organisms and assess the need to consider regulatory 

action. These criteria are used to indicate when a pesticide=s directed label use has the 

potential to cause adverse effects on non-target organisms. 

1. Non-target Animals 

Peak EECs were compared to acute measures of effect for fluroxypyr to derive acute RQs for 

fish, and invertebrates., Peak me& 2 1 -day and 60-day EECs could not be used to calculate 

chronic RQs for invertebrates and fish, respectively, because no chronic toxicity data was 

submitted by the registrant or available in the open literature. Results of the RQ calculations 

demonstrate the level of concern is only exceeded for acute risk to marinelestuarine 

invertebrates (Table 13). 

Table 13. Acute and chronic RQs for non-listed fish and aquatic invertebrates using 

the PRZM-EXAMS EECs 

Use site 

Taxa 

Freshwater 

fish 

Acute 

EEC 

@pm) 

0.009 

Chronic 

21 day160 

day EEC 

@pm) A 

0.00341 

0.0014 

Acute 

TOX. 

@pm ai) 

13.2 

Chronic 

Tox. 

@pm ai) 

No data 

available 

RQa @EC/Tox.) 

Acute 

@OC 

exceedances 

are in bold) 

0.0006 

Chronic 

@OC 

exceedan 

ces are in 

bold) 

NA 
fish respectively. 

The LOC for acute risk is not exceeded. 

The acute risk quotient value could not be calculated for freshwater invertebrates because the EC50 value for 

freshwater invertebrates > 100 ppm a.i which was the highest concentration. This study demonstrated that 

fluroxypyr is practically nontoxic to freshwater invertebrates. Thus, EFED does not expect fluroxypyr to pose 

a significant risk to freshwater invertebrates that will exceed the Agency LOC. 

The LOC for acute risk to estuarine marine invertebrates is exceeded. 

Use site 

Pome 

~ill~t 

A The 2 1 

b. Aquatic Plants 

Aquatic plant RQ's are calculated by dividing the peak EEC values for the proposed uses by 

the acute EC5() and NOAEC toxicity endpoints for risk to nonendangered and endangered 

vascular plants, and non-vascular plant to calculate acute RQs to non-listed aquatic plant 

species The Table 14 below lists the results of the RQ calculations. Based on these 

calculations the level of concern is not exceeded for risks to aquatic nonvascular or vascular 

plants. 

Taxa 

Freshwater 

invertebrate 

Estuarine 

fish 

Estuarine 

invertebrate 

Freshwater 

fish 

Freshwater 

invertebrate 

Estuarine 

fish 

Estuarine 

invertebrate 

day EEC and the 

Acute 

EEC 

@pm) 

0.009 

0.009 

0.009 

0.008 

0.008 

0.008 

0.008 

60 day EEC 

Chronic 

21 day160 

day EEC 

@pm) A 

0.00341 

0.0014 

0.00341 

0.00 14 

0.00341 

0.0014 

0.00281 

0.00074 

0.00281 

0.00074 

0.00281 

0.00074 

0.00281 

0.00074 

values are 

Acute 

Tox. 

@pm ai) 

> 100 

No 

endpoint 

available 

0.068 

13.2 

> 100 

No data 

available 

51 

used to calculate 

Chronic 

Tox. 

(ppm ai) 

No data 

available 

No data 

available 

No data 

available 

No data 

available 

No data 

available 

No data 

available 

No data 

available 

chronic risk 

RQa 

Acute 

&OC 

exceedances 

are in bold) 

NoLOC 

Exdeedance 

NA 

0.13 

0.006 

NoLOC 

Exdeedance 

NA 

0.00016 

quotients for 

(EECITox.) 

Chronic 

(LOC 

exceedan 

ces are in 

bold) 

NA 

NA 

NA 

NA 

NA 

NA 

NA 

invertebrates and 
A risk quotient value could not be calcuiated for aquatic vascular plant risk because the aquatic vascular plant 

ECsO value was greater than the highest concentration tested which was 2.3 ppm. An aquatic vascular plant 

ECS0 value > 2.3 ppm ai is far below the Agency LOC based on an acute EEC of 0.009 ppm. 

Table 14. Acute RQs for non-listed aquatic plants 

c. Terrestrial Animals 

Use site 

Pome 

Millet 

A Below the 

- Birds 

The T-REX model (version 1.2.3) is used to estimate risk to birds in fields treated with 

fluroxypyr MHE. The TREX model predicts peak EECs and uses these values in 

combination with the most sensitive acute and chronic toxicity values available to calculate 

risk quotients. Because fluroxypry MHE and fluroxypyr were practically nontoxic to birds 

on an acute dietary and acute oral basis (Appendix A), and there were no mortalities in any of 

the fluroxypy MHE or fluroxypy avian acute toxicity studies, EFED does not expect 

fluroxypyr to pose a significant risk to birds. Especially, since the estimated exposure values 

(Table 8) are several magnitudes lower than the concentrations which demonstrated that 

fluroxypyr MHE and fluroxypyr are practically nontoxic to birds. Thus, based on this 

conclusion of no acute risk to birds, EFED did not calculate any acute risk quotients for birds 

(Table 15). The table below demonstrates the results of the chronic RO calculations for 

birds. 

Taxa 

Aquatic 

nonvascular 

plants 

Aquatic 

vascular 

plants 

Aquatic 

nonvascular 

plants 

Aquatic 

vascular 

plants 

level of concern 

Acute 

EEC 

@pm) 

0.009 

0.009 

0.008 

0.008 

for risk to 

Aquatic 

plant 

EC50 

(PP~ ail 

0.29 

> 2.3 

0.29 

> 2.3 

aquatic plants 

Aquatic 

plant 

@pm ail 

0.18 

1.2 

0.18 

1.2 

RQ* (EEC/T~&) 

Non -listed 

aquatie plant 

RQ 

0.03 

Below LOC 

0.02 

Below LOC 

Listed aquatic 

plant RQ 

0.05 A 

0.0075 A 

0.04 A 

0.0067 
Table 15. Chronic RQs calculations for birds (Upper Bound Kenaga) 

Use site Food habits chronic 

I I 

tall grass 1 0.22 

short grass 

0.48 A 

I 

fruitslpods/lg insects 0.03 

MILLET 

I I 

broadleaf plantslsm insects 1 0.27 

short grass 

tall grass 

Mammals 

0.21 A 

0.10 

broadleaf plants/sm insects 

~ts/pods/lg insects 

The T-REX model (version 1.2.3) was used to estimate risk to mammals in fields treated 

with fluroxypyr MHE. Peak EECs were compared to the acute and chronic toxicity 

endpoints for the rat to calculate acute and chronic RQs to non-listed mammalian species. 

The respective LDso and chronic endpoint values are 125 mag (females) and 25 mag 

(mortality). Results are listed in Table 16. Based on the RQ calculations, there are no 

exceedances for the Agency LOC for mammals. 

0.12 

0.01 

Note A The LOC of 1 is not exceeded for chronic risk to birds 

Table 16. Acute and chronic RQs for non-listed mammals (Upper Bound Kenaga) 

Use site 

POME 

FRUIT 

Food habits 

0.05 A 

0.02 

short grass 

tall grass 

Chronic 

dietary 

based 

RQs 

dose-based RQs 

0.01 

< 0.01 

0.05 

0.01 

15g 

< 0.01 

< 0.01 

acute 

0.02 

0.01 

< 0.01 

< 0.01 

chronic 

35g 

< 0.01 

< 0.01 

acute 

lOOOg 

chronic acute Chronic 
0.2 for acute restricted use, 0.1 for acute endangered species. 

Note B: The chronic RQ is below the Agency LOC of 1 for chronic risk to mammals. 

Note ': The RQ value is below the Agency LOC for risk to mammals and is below the range of values that can 

be displayed by TREX. 

d. Non-target Upland and Wetland/Riparian Plants 

Peak EECs were calculated using TerrPlant (version 1 .O) and compared to the lowest EC25 

(Most Sensitive Toxicity Values, Table 12) to calculate RQs for non-listed terrestrial plant 

species. Fluroxypyr MHE RQ results are listed in Table 17 and 18. Based on the RQ 

calculations for the fluroxypyr MHE uses on apple and millet, the LOC is only exceeded for 

risks to dicot species. Risk quotients for Fluroxypyr MHE degradates, fluroxypyr could not 

be calculated because, the endpoint values produced in this study were deemed as 

inappropriate for use in a risk assessment because of several study deficiencies. 
Dicot listed 0.44 1.25 

*If RQ > 1 .O, the LOC is exceeded, resulting in potential for risk to that plant group. 

B. Risk Description - Interpretation of Direct Effects 

Summary of maior conclusions for non-listed species 

a. Risk to Aquatic Animals and Plants 

Acute Risk 

Based on the RQ calculations the only exceedances of the LOC are for acute risk to marine 

estuarine invertebrates. This LOC exceedance is only applicable to non Federally listed 

marinelestuarine invertebrates since there are no listed marinelestuarine invertebrates. 

Because the acute RQs for other aquatic animals' freshwater fish and aquatic invertebrate are 

several orders of magnitude below the Agency LOC and because fluroxypyr MHE and 

fluroxypyr is only slightly to practically nontoxic to fish and aquatic invertebrate, EFED does 

not expect fluroxypyr to pose a significant acute risk to fish andlor aquatic invertebrate. 

The RQ calculations for fluroxypyr and fluroxypyr MHE risk to aquatic plants also 

demonstrate RQ values several orders of magnitudes below the LOC for risk to aquatic 

plants. Thus, fluroxypyr is not expected to pose a significant risk to aquatic plants. 
Chronic Risk 

EFED could not assess the chronic risk to freshwater and estuarinelmarine fish and 

invertebrates at this time due to lack of registrant submitted and open literature studies. 

Aquatic plant risk 

Based on the RQ calculations for fluroxypyr there are no LOC exceedances for aquatic plants 

and algae. Thus, EFED does not expect fluroxypyr MHE or fluroxypyr to pose significant 

risk to aquatic plants or algae. The registrant submitted toxicity data for aquatic plant and 

algae on the degradates, 4-Amino-3,5-dichloro-6-fluoro-2-pyridinol and 4-Amino-3,5- 

dichloro-6-fluoro-2-methoxypyridine. Risk quotients are not calculated for these degradates 

because of the lack environmental fate data on the degradates. However, EFED does not 

expect these degradates to pose a significant risk to aquatic plants or algae because the 

toxicity data demonstrated that aquatic plants and algae were less sensitive to these than to 

fluroxypyr, which itself does not exceed the Agency level of concern for risk. 

b. Risk to Terrestrial Animals 

In the terrestrial environment fluroxypyr MHE is also expected to degrade to fluroxypyr. 

However, fluroxypyr MHE degradation to fluroxypyr in a terrestrial environment may not 

occur as rapidly as in aquatic environments, and potential exposure exists immediately upon 

application (unlike the aquatic environment, where exposure is unlikely prior to a runoffinducing rain event).. Thus terrestrial animals are expected to be readily exposed to 

fluroxypyr MHE and fluroxypyr. Consequently, this risk assessment characterizes the risk of 

fluroxypyr MHE and fluroxypyr to terrestrial animals exposed to these chemicals. 

Avian Acute Risk 

Although avian acute risk quotients were not calculated, EFED does not expect fluroxypyr or 

fluroxypyr MHE to pose a significant acute risk to birds because the avian acute toxicity test 

demonstrated that both fluroxypyr MHE and fluroxypyr were practically nontoxic to birds on 

an acute oral and acute dietary basis at concentrations that were several orders of magnitude 

higher than the estimated concentrations expected in a terrestrial environment. 

Avian Chronic Risk 

EFED does not expect fluroxypyr MHE to pose any significant risk to avian species because 

the RQ values were well below the LOC for chronic risk to birds. Currently, EFED is unable 

to determine the chronic risk of fluroxypyr to birds because no fluroxypyr avian chronic 

toxicity data are available. However, Agency believes this risk to probably be low, based 

upon absence of chronic avian risk fiom fluroxypyr-MHE and lack of chronic risk to 

mammals from fluroxypyr. Thus, avian chronic toxicological studies for fluroxypyr may not 

be necessary. 

45 
Mammalian Acute Risk 

Currently the Agency has mammalian acute and chronic toxicity data for fluroxypyr only and 

not fluroxypyr MHE. Based on the fluroxypyr mammalian risk quotient calculations, 

fluroxypyr is not expected to pose significant acute or chronic risk to mammals especially 

since the RQ values are well below any LOC for risk to mammals. 

c. Risk to Plants 

Based on the terrestrial plant RQs, spray drift from flwoxypyr MHE application to pome 

fruit poses a risk above the LOC for listed and nonlisted dicot plant species. The RQs also 

specifically demonstrate that spray drift from fluroxypyr MHE use on millet poses a risk 

above the LOC for listed dicot species only. Additionally, based on supplemental data, 

fluroxypyr is more toxic to emerging seedlings than fluroxypyr MHE. The most sensitive of 

the six species tested is cotton, which has an EC25 of 0.025 lb ai/A. This is approximately 5 

times lower than the cotton ECz5 of 0.125 lbs. ai/A for fluroxypyr MHE (Appendix B). 

However, the endpoint values produced in this study were deemed as inappropriate for 

calculating risk quotients because of several study deficiencies. Thus, EFED assumes 

fluroxypyr may pose a greater risk to terrestrial nontarget plants. However, EFED needs 

adequate terrestrial plant toxicity data testing fluroxypyr in order to more effectively 

determine the risk of fluroxypyr to terrestrial plants. 

C. Federally Threatened and Endangered (Listed) Species Concerns 

a. Action Area 

For listed species assessment purposes, the action area is considered to be the area affected 

directly or indirectly by the Federal action and not merely the immediate area involved in the 

action. At the initial screening-level, the risk assessment considers broadly described 

taxonomic groups and so conservatively assumes that listed species within those broad 

groups are collocated with the pesticide treatment area. This means that terrestrial plants and 

wildlife are assumed to be located on or adjacent to the treated site and aquatic organisms are 

assumed to be located in a surface water body adjacent to the treated site. The assessment 

also assumes that the listed species are located within an assumed area, which has the 

relatively highest potential exposure to the p.esticide, and that exposures are likely to decrease 

with distance from the treatment area. The Use Characterization of this risk assessment 

presents the pesticide use sites that are used to establish initial collocation of species with 

treatment areas. 

If the assumptions associated with the screening-level action area result in RQs that are 

below the listed species LOCs, a "no effect" determination conclusion is made with respect 

to listed species in that taxa, and no further refinement of the action area is necessary. 

Furthermore, RQs below the listed species LOCs for a given taxonomic group indicate no 

concern for indirect effects upon listed species that depend upon the taxonomic group 

46 
covered by the RQ as a resource. However, in situations where the screening assumptions 

lead to RQs in excess of the listed species LOCs for a given taxonomic group, a potential for 

a "may affect" conclusion exists and may be associated with direct effects on listed species 

belonging to that taxonomic group or may extend to indirect effects upon listed species that 

depend upon that taxonomic group as a resource. In such cases, additional information on 

the biology of listed species, the locations of these species, and the locations of use sites 

could be considered to determine the extent to which screening assumptions regarding an 

action area apply to a particular listed organism. These subsequent refinement steps could 

consider how this information would impact the action area for a particular listed organism 

and may potentially include areas of exposure that are downwind and downstream of the 

pesticide use site. 

b. Taxonomic Groups potentially at Risk 

The Level I screening assessment process for listed species uses the generic taxonomic 

group-based process to make inferences on direct effect concerns for listed species. The first 

iteration of reporting the results of the Level I screening is a listing of pesticide use sites and 

taxonomic groups for which RQ calculations reveal values that meet or exceed the listed 

species LOCs. In the majority of cases, the screening-level risk assessment process reports 

RQ calculations for the following broad taxonomic groupings: 

Birds (also used as surrogate for terrestrial-phase amphibians and reptiles) 

Mammals 

Freshwater fish (also used as a surrogate for aquatic phase amphibians) 

Freshwater invertebrates 

Estuarine and marine fish 

Estuarine and marine invertebrates 

Terrestrial invertebrates 

Terrestrial plants 

Aquatic plants 

(1) Discussion of Risk Quotients 

Risk Quotients Based on Maximum Application Rate Scenarios 

As mentioned above, there are fluroxypyr MHE LOC exceedances for dicot terrestrial plants. 

These exceedances range from 1.75 to 2.55. 

(2) Probit Dose-Response Relationship 

A. Probit Slope Response Relationship on the Listed Species Levels of Concern 

The Agency uses the probit dose response relationship as a tool for providing additional 

information on the listed animal species acute levels of concern (LOC). The acute listed 
species LOCs of 0.1 and 0.05 are used for terrestrial and aquatic animals, respectively. As 

part of the risk characterization, an interpretation of acute LOCs for listed species is 

discussed. This interpretation is presented in terms of the chance of an individual event (i.e., 

mortality or immobilization) should exposure at the estimated environmental concentration 

actually occur for a species with sensitivity to fluroxypyr with the acute toxicity endpoint 

selected for RQ calculation. To accomplish this interpretation, the Agency uses the slope of 

the dose response relationship available from the toxicity study used to establish the acute 

toxicity measurement endpoints for each taxonomic group. The individual effects probability 

associated with the LOCs is based on the mean estimate of the slope and an assumption of a 

probit dose response relationship. In addition to a single effects probability estimate based on 

the mean, upper and lower estimates of the effects probability are also provided to account 

for variance in the slope. The upper and lower bounds of the effects probability are based on 

available information on the 95% confidence interval of the slope. A statement regarding the 

confidence in the applicability of the assumed probit dose response relationship for 

predicting individual event probabilities is also included. Studies with good probit fit 

characteristics (i.e., statistically appropriate for the data set) are associated with a high degree 

of confidence. Conversely, a low degree of confidence is associated with data fiom studies 

that do not statistically support a probit dose response relationship. In addition, confidence in 

the data set may be reduced by high variance in the slope (i.e., large 95% confidence 

intervals), despite good probit fit characteristics. 

Individual effect probabilities are calculated based on an Excel spreadsheet tool IECV1.l 

(Individual Effect Chance Model Version 1.1) developed by EFED of the U.S. EPA, 

OPP, Environmental Fate and Effects Division (June 22,2004). The model allows for such 

calculations by entering the mean slope estimate (and the 95% confidence bounds of that 

estimate) as the slope parameter for the spreadsheet. In addition, the LOC (0.1 for terrestrial 

animals and 0.05 for aquatic animals) is entered as the desired threshold. The following is the 

summary of screening assessment of listed terrestrial and aquatic species Levels of Concern 

using probit slope relationship. 

Table 19 Probit Slope and Effects Probabilities 

Listed Sp. 

Acute Tox. End 

Point 

LD50/EC50/Lc50 

Probit x2value 

Mean Slope 

Slope Confid. 

Interval 

Effect probability p 

Mallard Duck 

No Mortalities 

NA 

NA 

NA 

NA 

Rat 

3160 

NA 

4.5* 

NA 

3.4E-06 

Daphnia 

No mortalities 

NA 

NA 

NA 

NA 

Bluegill 

14.3 

NA 

4.5" 

NA 

2.39E-09 
Based on the above table, the results of probit slope analysis show that chance of 

individual effect is minimal. The effect probability p(Z) ranges is 3.40E-06 for rat and 

2.40E-09 for bluegill. Since a slope value is unavailable, a default value of 4.5 has been 

assigned in the case of rat, and bluegill. Furthermore, if they share the same slope and LOC 

values (0.1 or 0.05), they will have the same effect probability and hence the chance of 

individual effect. 

(Z) 

(Confidence 

Interval) 

Chance of 

Individual effect 

(11~) 

1. Terrestrial Listed Species (Mallard duck and rat) 

There were no mortalities in the avian toxicity studies. Therefore a probit analysis was not 

performed for birds. Calculations for rat yielded an effect probability (z value) of 3.40E-06 

and individual mortality probability of 1 in 2.94E+05. 

* default slope value (4.5) had to be used due to lack of information 

NA 

2. Aquatic Listed Species (daphnia and rainbow trout) 

There were no mortalities in the aquatic invertebrate toxicity studies. Therefore a probit 

analysis was not performed for aquatic invertebrates. Calculations for rat yielded an effect 

probability (z value) of 2.39E-09 and individual mortality probability of 1 in 4.1 8E+08. 

2.94+05 

(3) Indirect Effects Analysis 

The Agency acknowledges that pesticides have the potential to exert indirect effects upon the 

listed organisms by, for example, perturbing forage or prey availability, altering the extent of 

nesting habitat, creating gaps in the food chain, etc. 

NA 

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-listed organisms in these taxonomic groups as resources critical to their life 

cycle. 

4.18E+08 

Screening-level acute RQs for terrestrial plants and marine estuarine invertebrates are above 

the LOCs. The Agency considers this to be indicative of a potential for adverse effects to 

those listed species within the action area that rely either on a specific plant species (plant 

species obligate) or multiple plant species (plant dependent) for some important aspect of 

49 
their life cycle. The Agency may determine if listed organisms, for which plants were a 

critical component of their resource needs, are within the action area. This will be 

accomplished through a comparison of Service-provided species profiles and listed species 

location data. If no listed organisms that are either plant species obligates or plant dependent 

reside within the action area, a no effect determination on listed species will be made. If 

plant species obligate or dependent organisms reside within the pesticide use area, the 

Agency will consider temporal and geographical nature of exposure, and the scope of the 

effects data, to determine if any potential effects can be determined to not likely adversely 

affect a plant species obligate or dependent listed organism. 

EFED concludes that due to terrestrial plant and marine estuarine invertebrate LOC 

exceedances (using maximum application rates), there may be a concern for indirect effects 

to the following groups of organisms in the area for the fluroxypyr MHE regulatory action: 

Freshwater fish 

Freshwater amphibians 

Freshwater invertebrates 

Terrestrial invertebrates 

Terrestrial plants and plants in semi-aquatic areas 

Birds 

Mammals 

Reptiles 

For listed species that may potentially be affected directly and/or indirectly by the Federal 

action, see Appendix C (Locates runs). 

(4) Critical Habitat 

In the evaluation of pesticide effects on designated critical habitat, consideration is given to 

the physical and biological features (constituent elements) of a critical habitat identified by 

the U.S Fish and Wildlife and National Marine Fisheries Services as essential to the 

conservation of a listed species and which may require special management considerations or 

protection. The evaluation of impacts for a screening level pesticide risk assessment focuses 

on the biological features that are constituent elements and is accomplished using the 

screening-level taxonomic analysis (risk quotients, RQs) and listed species levels of concern 

(LOCs) that are used to evaluate direct and indirect effects to listed organisms. 

The screening-level risk assessment has identified potential concerns for indirect effects on 

listed species for those organisms dependant upon terrestrial plants and marine estuarine 

invertebrates. In light of the potential for indirect effects, the next step for EPA and the 

Service(s) is to identify which listed species and critical habitat are potentially implicated. 

Analytically, the identification of such species and critical habitat can occur in either of two 

ways. First, the agencies could determine whether the action area overlaps critical habitat or 
the occupied range of any listed species. If so, EPA would examine whether the pesticide's 

potential impacts on non-listed species would affect the listed species indirectly or directly 

affect a constituent element of the critical habitat. Alternatively, the agencies could determine 

which listed species depend on biological resources or have constituent elements that fall into 

the taxa that may be directly or indirectly impacted by the pesticide. Then EPA would 

determine whether use of the pesticide overlaps the critical habitat or the occupied range of 

those listed species. At present, the information reviewed by EPA does not permit use of 

either analytical approach to make a definitive identification of species that are potentially 

impacted indirectly or critical habitats that is potentially impacted directly by the use of the 

pesticide. EPA and the Service(s) are working together to conduct the necessary analysis. 

This screening-level risk assessment for critical habitat provides a listing of potential 

biological features that, if they are constituent elements of one or more critical habitats, 

would be of potential concern. These correspond to the taxa identified above as being of 

potential concern for indirect effects and include the following: fish and aquatic 

invertebrates, amphibians, birds, mammals, and reptiles. This list should serve as an initial 

step in problem formulation for further assessment of critical habitat impacts outlined above, 

should additional work be necessary. 

c. Co-occurrence Analysis 

The goal of the analysis for co-location is to determine whether sites of pesticide use are 

geographically associated with known locations of listed species. At the screening level, this 

analysis is accomplished using the LOCATES database. The database uses location 

information for listed species at the county level and compares it to agricultural census data 

for crop production at the same county level of resolution. The product is a listing of 

federally listed species that are located within counties ktiown to produce the crop upon 

which the pesticide will be used. Because the Level I screening assessment considers both 

direct and indirect effects across generic taxonomic groupings, it is not possible to exclude 

any taxonomic group from a LOCATES database run for a screening risk assessment. 

Given the extent of fluroxypyr usage across the U.S. and\the expected large number of listed 

species that are likely,to occur in counties where this pesticide is used, a list of 

endangeredlthreatened species and crop acreage at the county level for the taxonomic groups 

and crops of concern is not included in this phase of the risk assessment process. 

Appendix C provides a list of endangeredlthreatened species at the state level for the 

taxonomic groups of concern. EFED assumes that listed species may be at risk for the states 

where pome fruit and millet use occurs according to LOCATES, but where fluroxypyr usage 

is not reported necessarily by BEAD Usage Report. The registrant must provide information 

on the proximity of Federally listed freshwater invertebrates, terrestrial and aquatic plants, 

birds, mammals, amphibians, crustaceans, reptiles, arachnids, insects, snails, and clams to the 

fluroxypyr use sites. This requirement may be satisfied in one of three ways: 1) having 

membership in the FIFRA Endangered Species Task Force (Pesticide Registration [PR] 

Notice 2000-2); 2) citing FIFRA Endangered Species Task Force data; or 3) independently 

5 1 
producing these data, provided the information is of sufficient quality to meet FIFRA 

requirements. The information will be used by the OPP Endangered Species Protection 

Program to develop recommendations to avoid adverse effects to listed species. 
V. REFERENCES 

EPA's Wildlife Exposure Factors Handbook (1996) 

Haarstad, K. and G.H. Ludvigsen (2007) Ten Years of Pesticide Monitoring in Norwegiam 

Ground Water. Ground Water Monitoring & Remediation 27 (3), 75-89. 

Hoerger and Kenaga (1 972) as modified by Fletcher et al. (1 994) 

Waugh, P.S. and A.V. Padovan (2004) Review of Pesticide Monitoring, Use and Risk to 

Water Resources in the Darwin Region. Report No. 02/2004D, Natural Resource 

Management Division Conservation and Natural Resources Group. 
Appendix A 

a. Toxicity to Terrestrial Animals 

I. Birds, Acute and Subacute 

An acute oral toxicity studyusing the technical grade of the active ingredient (TGAI) is required 

to establish the toxicity to birds. The preferred test species is either mallard duck (a waterfowl) 

or bobwhite quail (an upland gamebird). The registrant submitted acute oral avian toxicity tests 

on fluroxypyr acid and fluroxypyr MHE. The tests indicated that fluroxypyr acid and fluroxypyr 

MHE are practically nontoxic to avian species on an acute oral basis. Results and further details 

of these tests are tabulated below. 

Avian Acute Oral Toxicity 

MRID No. Study 

Species Chemical LD50 (mglkg Toxicity Category Authorh'ear Classification1 

ail 

Mallard duck 

Fluroxypyr acid > 2000 Practically nontoxic 40244514 Supplemental 

Bobwhite quail 

Fluroxypyr acid > 2000 Practically nontoxic 402445 15 Acceptable 

Mallard duck 

Fluroxypyr MHE > 2000 Practically nontoxic 402445 16 Acceptable 

Bobwhite quail 

Fluroxypyr MHE > 5000 Practically nontoxic 4024451 7 Acceptable 

Bobwhite quail 

Fluroxypyr MHE > 2000 Practically nontoxic 40244546 Acceptable 

~cceptabli (study satisfies guideline). 

Two subacute dietary studies using the TGAI are required to establish the toxicity of the TGAI to 

birds. The preferred test species are mallard duck and bobwhite quail. The registrant submitted 

subacute dietary tests on the parent compound, fluroxypyr MHE, and the fluroxypyr acid. 

Fluroxypyr MHE and fluroxypyr acid is practically nontoxic to avian species on an acute dietary 

basis. Results of these tests and further details are tabulated below. 

Avian Subacute Dietary Toxicity 

5-Day LC50 MRID No. 

Species Chemical (PP~ ai)Toxicity Catego~y AuthorNear Study Classification1 

Bobwhite quail Fluroxypyr acid > 5000 Practically nontoxic 40244547 Acceptable 

Mallard duck Fluroxypyr > 5620 Practically nontoxic 42137302 Acceptable 

acid 

Mallard duck 

Fluroxypyr MHE > 5620 Practically nontoxic 42137301 Acceptable 

Acceptable (study satisfies guideline). Supplemental (study is scientifically sound, but does not satisfy guideline. 
ii. Birds, Chronic 

The registrant has submitted a bird reproductive toxicity studies testing the fluroxypyr MHE on 

bobwhite quail, and mallard. Details of the studies are tabulated below. 

Avian Chronic Toxicity Study 

NOEC LQEC Endpoints affected MRID No. 

Species Chemical Study Classification' 

% ai Toxic Toxic 

Endpoint Endpoint 

(PP~ ai) (ppm ai) 

42137303 

Northern Bobwhite Fluroxypyr 5620 > 1000 None Acceptable 

MHE 

42137304 

Mallard Duck Fluroxypyr 250 500 Egg yolk Acceptable 

MHE peritonitis in hens 

iii. Mammals, Acute and Chronic 

Wild mammal testing is required on a case-by-case basis, depending on the results of lower tier 

laboratory mammalian studies, intended use pattern and pertinent environmental fate 

characteristics. In most cases, rat or mouse toxicity values obtained from the Agency's Health 

Effects Division (HED) substitute for wild mammal testing. These toxicity values are reported 

below. 

Table 8. Chronic 

Species 

Laboratory rat 

(Rattus 

norvegicus) 

NOEL/LOEL 

O?P~ ail 

1000 ppm 

750 ppm 

10,000 ppm 

MRU) No. 

44080321 

Mammalian Toxicity 

Test Type 

2-generation 

l-eproduction 

Acute Oral Toxicity for fluroxypyr 

for Fluroxypyr 

Endpoint 

Parental toxicity ((increased kidney 

weight with corresponding gross 

and microscopic findings including 

papillary atrophy, edema, necrosis, 

hypqlasia of the pelvic epithelium, 

degenem!ion/regenemtion of the 

tubular epithelium, tubulo-intersftial 

nephritis, and dilatation of the 

tubules)) 

Reproduction 

Pup sunrival and weight gain 

LD50 a.i 

790 mdkg ai 

Species 

Laboratory rat 

(Rattus 

norvegicus) 

MRID 

44080329 

Test 

Type 

Acute 

oral 

% ai 

25.6% 

Endpoint 

Mortality 
The results indicate that fluroxypry MHE is practically nontoxic to small mammals on an acute 

oral basis. 

iv. Insects 

A honey bee acute contact study using the TGAI is required because the proposed uses may 

result in honey bee exposure. Results of this test are tabulated below. 

Nontarget Insect Acute Contact Toxicity 

LD50 MRID No. Study 

Species Chemical (ug ai.ibee) Toxicity Categoly Classification 

Honey Bee 

Fluroxypry > 25 Relatively non-toxic 42137314 Acceptable 

acid 

Honey Bee 40244527 

Fluroxypry Could not be NA 

determined 

MHE 

Supplemental 

The results as demonstrated above indicate that fluroxypyr acid is relatively non-toxic to bees on 

an acute contact basis. 

b. Toxicity to Freshwater Aquatic Animals 

I. Freshwater Fish, Acute 

Two freshwater fish toxicity studies using the TGAI are required to establish the toxicity to fish. 

The preferred test species are rainbow trout (a coldwater fish) and bluegill sunfish (a warm water 

fish). The registrant submitted studies on the fluroxypyr MHE and fluroxypry acid. Results of 

these tests are tabulated below. 
Freshwater Fish Acute Toxicity 

96-hour 

Species (all of testing LC50 (ppm ai) MRID No. Study 

Below are Static) Chemical Toxicity Category Classification 

Golden Orfe 40244519 

Fluroxypyr > 100 

acid 

Bluegill sunfish 

Fluroxypyr 14.3 

acid 

Rainbow trout 

Fluroxypyr > 100 

acid 

Inland silverside 

Fluroxypyr 40 

MHE 

Bluegill sunfish 

Fluroxypyr r 0.63 

Practically Acceptable 

nontoxic 

42137306 

Slightly Toxic Acceptable 

4024451 8 

Practically Acceptable 

nontoxic 

Slightly toxic 44080309 Acceptable 

Not determined 44080307 Acceptable 

MHE 

Rainbow trout 

Fluroxypyr > 0.7 Not determined 402445-22 Acceptable 

Golden Orfe 

MHE 

Fluroxypyr > 0.7 

MHE 

Rainbow trout 

Fluroxypyr 13.42 

402445-23 

Not determined Supplemental 

402445-25 

Slightly Supplemental 

MHE 

Bluegill sunfish 

Fluroxypyr NA N A 421373-05 Invalid 

MHE 

Since the LC50 falls in the range of 14.3- > 100 ppm ai, fluroxypyr MHE and fluroxypyr acid is 

ranges from slightly to practically non-toxic to freshwater fish on an acute basis. 

ii. Freshwater Fish, Chronic 

Currently, no fish chronic toxicity studies have been submitted to the Agency. 

iii. Freshwater Invertebrates, Acute 

A fieshwater aquatic invertebrate toxicity test using the TGAI is required to establish the toxicity 

to aquatic invertebrates. The preferred test species is Daphnia magna. Results of this test are 

tabulated below. 
Freshwater Invertebrate Acute Toxicity 

48-hour EC50 

Species (PP~ ai)MRID No. Study Classification 

%ai Toxicity Category AuthorNear 

Water flea 

Water flea 

Water flea 

Fluroxypyr > 100 Practically 40244524 Acceptable 

acid nontoxic 

Fluroxypyr > 100 Practically 4024452 1 Acceptable 

acid nontoxic 

Fluroxypyr > 0.6 Not determined 40244520 Acceptable 

MHE 

Water flea 

Fluroxypyr > 0.109 ppm Not determined 421373-08 Acceptable 

MHE 

Since the ECS0 falls in the range of >I00 ppm, fluroxypyr acid is practically nontoxic to 

practically nontoxic to aquatic invertebrates on an acute basis. The guideline (72-2) is fulfilled 

(MRIDs 40244524, and MRID 40244521). 

iv. Freshwater Invertebrate, Chronic 

The registrant has submitted one freshwater chronic toxicity study testing fluroxypyr MHE. The 

results of the study are tabulated below. 

LOEAUNOEAL MRID No. 

ppm ai Authoriyear Species Study Classification 

% ai 

Water flea Fluroxypyr MHE 0.1091 0.06 44080314 Supplanental 

c. Toxicity to Estuarine and Marine Animals 

I. Estuarine and Marine Fish, Acute 

Acute toxicity testing with estuarine and marine fish using the TGAI is required because the enduse product is intended for application sites near coastal counties. 

The registrant submitted to the Agency one estuarine and marine fish acute toxicity test using the 

longnose killifish. Based on the results of this study, fluroxypyr MHE is practically nontoxic to 

estuarine and marine fish. The results of this study are illustrated in the table below. 
Estuarine and Marine Fish Acute Toxicity 

Species (all of testing MRID No. Study 

Below are Static) - %ai (ail Toxicity Category AuthorNear Classification 

Atlantic Silverside 

Fluroxypyr > 0.188 Not determined 42137309 Supplemental 

MHE 

Sheepshead minnow Fluroxypyr 44080308 > 0.087 (> 100 Not determined Acceptable MHE nominal) 

ii. Estuarine and Marine Fish, Chronic 

The registrant did not submit any chronic toxicity data testing marine estuarine organisms. 

iii. Estuarine and Marine Invertebrates, Acute 

Acute toxicity testing with estuarine and marine invertebrates using the TGAI is required 

because the end-use product is intended for application sites near coastal counties. 

The following table demonstrates the toxicity of fluroxypyr acid and fluroxypyr MHE. Oysters 

appear to be more sensitive than shrimp and fish to fluroxypyr acid and fluroxypyr MHE. Since 

the LC50 for the eastern oyster fall in the range of 10 to 100 ppm, Fluroxypyr acid is considered 

slightly toxic to estuarine and marine invertebrates on an acute basis. Fluroxypyr MHE had an 

LC50 of 0.0068 ppm for eastern oyster, categorizing it as very highly toxic to estuarine and 

marine invertebrates on an acute basis. Fluroxypyr MHE is not toxic to marine and estuarine 

shrimp at its solubility limit. 
Table 11. Acute Toxicity to EstuarineiMarine Invertebrates 

SpeciesITest Type 

Eastern oyster 

(Crassostrea virginica), 

Flow-through shell 

deposition I I I I 

440803 1 1 

Boeri, Kowalski, and 

Ward, 1994 

96-hour LC50 or 

EC50 (mg aUL) 

51 (measured) Acceptable 

Flmoxypyr MHE 

I I I I 

Slightly toxic 

Grass shrimp 

(Palaemonetes pugio), 

Flow-through 

Toxicity Category 

Eastern oyster 

(Crassostrea virginica), 

Flow-through shell 

>I20 (measured) 

Eastern oyster 

(Crussostrea virginica), 

Flow-through shell 

MRlD No. 

AuthoriYear 

Acceptable 

Study Classification 

Practically nontoxic 

0.068 (measured) 

Not determined' 45725801 

Springborn 

Laboratories 

-. duorarum), Flow-through I >0.13 (measured) I Not determined3 I Manning 1988 I Supplemental I 

1 ECS0 was higher than the highest concentration tested. 

44080312 

Boeri, Kowalski, and 

Ward, 1994 

Very highly toxic 

Grass shrimp 

(Palaemonetes pugio), 

Flow-through 

2.A test concentrations at the solubility limit caused no mortality 

3 Five percent mortality occurred at the solubility limit. 

Acceptable 

iv. Estuarine and Marine Invertebrate, Chronic 

44080310 

Boeri, Kowalski, and 

Ward, 1995 

> 0.135 (measured) 

The registrant did not submit any chronic toxicity data testing estuarine and marine invertebrate. 

Supplemental 

Not detamined2 

44080313 

Boeri, Kowalski, and 

Ward, 1995 Acceptable 
d. Toxicity to Plants 

I. Terrestrial 

Terrestrial plant testing (seedling emergence and vegetative vigor) is required because 

fluroxypyr has terrestrial non-residential outdoor use patterns and it may move off the 

application site through spray drift or runoff. 

For seedling emergence and vegetative vigor testing the following plant species and groups 

should be tested: (1) six species of at least four dicotyledonous families, one species of which 

is soybean (Glycine max), and the second of which is a root crop, and (2) four species of at 

least two monocotyledonous families, one of which is corn (Zea mays). 

Terrestrial Tier 11 studies are required for all low dose herbicides (those with the maximum 

use rate of 0.5 lbs ai/A or less) and any pesticide showing a negative response equal to or 

greater than 25% in Tier I tests. Tier I1 tests measure the response of plants, relative to a 

control, and five or more test concentrations. Results of Tier I1 toxicity testing on the 

technicaVTEP material for the most sensitive species are as follows. 

Toxicity to Plants 

i. Terrestrial 

Results of Tier I1 seedling emergence toxicity testing with a formulated product of 

fluroxypyr MHE are given in Table J. The most sensitive test species for seedling emergence 

effects was cucumber. The EC25 and the NOEC for cucumber are 0.075 and 0.03 1 lb ai/A. 

Fluroxypyr MHE is generally not toxic to monocots at 0.25 lb ai/A. 
Table J. Phytotoxicity of Fluroxypyr MHE-Tier I1 Seedling Emergence Tests 

Most Sensitive Eczs NOEC Study Classification 

Species Parameter (lb ai/A) (lb ai/A) MRID No. 

AuthorNear 

Corn (monocot) All similar >0.25 0.25 44080335 Acceptable 

Schwab, 1996 

Onion (monocot) All similar >0.25 0.25 Acceptable 

Ryegrass (monocot) Phytotoxic >0.25 0.124 Acceptable 

SymPtOn= 

Wheat (monocot) All similar >0.25 0.25 Acceptable 

Cotton (dicot) Phytotoxic 0.125 0.062 

symptoms 

Cucumber (dicot) Phytotoxic 0.075 0.03 1 

symptoms 

Acceptable 

Acceptable 

Radish (dicot) All similar >0.25 0.25 Acceptable 

Soybean (dicot) Phytotoxic 0.24 0.062 

symptoms 

Sunflower (dicot) Phytotoxic 0.109 0.062 

symptoms 

Tomato (dicot) Shoot fresh 0.142 0.124 

weight 

Acceptable 

Acceptable 

Acceptable 

1 This NOEL is based on 17% mortality of plants occurring at the next higher test level, 0.01 1 lb ai/A. 

2 Seedling emergence data for lyegiass is upgraded from supplemental to acceptable. 

Results of Tier I1 seedling vegetative vigor toxicity testing on a formulated product of 

fluroxypyr MHE are given in Table K. The most sensitive species was cotton. Based on the 

most sensitive parameter, phytotoxic symptoms, 25% idubition was predicted to occur at a 

dose of 0.0012 lb ai/A. The no observed effect level (NOEL) was 0.0010 lb ai/A. 
Table K Phytotoxicity of Fluroxypyr MHE-Tier II Vegetative Vigor Tests 

Most Sensitive EC25 NOEC Study 

Species Parameter (lb aVA) (lb aVA) MRID No.; AuthorNear Classification 

Corn (monocot) Phytotoxic 0.176 0.03 1 44080335; Schwab, 1996 Acceptable 

symptoms 

Onion (inonocot) Phytotoxic 0.124 0.062 

symptom 

Acceptable 

Ryegrass (monocot) All similar >0.25 0.25 Acceptable 

Wheat (monocot) Phytotoxic >0.25 0.062 

symptom 

Cotton (dicot) Phytotoxic 0.0012 0.0010 

symptoms 

Acceptable 

Acceptable 

Cucumber (dicot) Phytotoxic 0.010 

symptoms 

0.004 Acceptable 

Radish (dicot) All similar 0.056 0.03 1 Acceptable 

Soybean (dicot) Phytotoxic 0.008 0.004 

symptoms 

Sunflower (dicot) Phytotoxic 0.004 0.001 

symptoms 

Tomato (dicot) Shoot fresh 0.004 0.001 

weieht 

Acceptable 

Acceptable 

Acceptable 

Since fluroxypyr MHE might degrade to fluroxypyr acid before reaching nontarget plants, 

data on the phytotoxicity of fluroxypyr acid to emerging seedlings is given in Table L. 

Table L. Phytotoxicity of Fluroxypyr Acid-Tier I1 Seedling Emergence Tests 

Most Sensitive ECz5 MRID No.; Study 

Species Parameter (lb aUA) Authornear Classification 

Corn (monocot) Fresh weight 0.178 44094902; Wright and Supplemental 

Rowland, 1996 

Wheat (monocot) Fresh weight 0.079 Supplemental 

Cotton (dicot) Fresh weight 0.025 Supplemental 

Radish (dicot) Fresh weight 0.295 Supplemental 

Soybean (dicot) Fresh weight 0.072 Supplemental 

Sunflower (dicot) Plant height 0.036 Supplemental 

Based on supplemental data, fluroxypyr acid is more toxic to emerging seedlings than 

fluroxypyr MHE. The most sensitive of the six species tested is cotton, which has an ECZ5 of 

0.025 lb ai/A. This is approximately 5 times lower than the cotton EC25 for fluroxypyr MHE. 
Table M. Phytotoxicity of Fluroxypyr Acid-Tier I1 Vegetative Vigor Tests 

Most Sensitive ECzs MRD No.; Study Classification 

Species Parameter (Ib aiJA) AuthorJYear 

Corn (monocot) Fresh weight > 0.5 44094902; Wright and Supplemental 

Rowland, 1996 

Wheat (inonocot) Fresh weight > 0.5 Supplemental 

Cotton (dicot) Fresh weight ND Supplemental 

Radish (dicot) Fresh weight > 0.5 Supplemental 

Soybean (dicot) Fresh weight 0.00067 Supplemental 

Sunflower (dicot) Plant height ND Supplemental 

The fluroxypyr acid data cannot be used to calculate risk quotient calculation because of 

several deviations in the study. However, the study is deemed supplemental. This 

supplemental data suggest that fluroxypyr acid is more toxic to vegetative vigor than 

fluroxypyr MHE. The most sensitive of the six species in the fluroxypyr acid study is 

soybean which produced an EC2~ of 0.00067 lb ai/A. This is approximately 12 times lower 

than the soybean EC25 for fluroxypyr MHE. 
ii. Aquatic Plants 

The results of the Aquatic plant toxicity tests are given in Table M. 
Table N. Nontarget Aquatic Plant Toxicity (Tier 2) 

EGO NOEC MRIDN~. study Classification 

Species (ppm ai) (ppm ai) AuthorNear 

Fluroxypyr Acid 

Green algae 

Kirchnena subcapitata 

Green algae 

chlorella vulgaris 

-- -- 42164501 Invalid 

Cowgill, Milazzo, and 

Murphy, 1988 

>lo0 100 40244526 

Jones, 1984 

Duckweed 7.7 ND 44094902 Invalid 

Lemna gibba 

Duckweed 

Lemna zibba 

>3.2 3.2 4501 16-02 Acceptable 

Ward, Mazazu. and Boeri 

Fresh water Green Alga >3.4 3.4 4501 16-03 Acceptable 

Selenastrum capricomutum Ward, Mazazu, and Boeri 

Freshwater Diatom 

Navicula uelliculosa 

1.1 0.19 450116-01 Acceptable 

Ward. Mazazu. and Boeri - 

Blue-green Algae > 2.9 0.36 450116-04 Acceptable 

Anabaena flos-aquae Ward, Mazazu, and Boeri 

Marine diatom > 3.0 3.0 450116-05 Acceptable 

Skeletonema costaturn Ward, Mazazu, and Boeri 

Fluroxypyr MHE 

Green algae 

Kirchneria subcapitata 

Fresh water Green Alga 

Selenastrum capricomutum 

Fresh water Green Alga 

Selenastrum capricomutum 

Green algae 

Kivchnena subcapitata 

Duckweed 

Lemna gibba 

Duckweed 

Lemna gibba 

Bluegreen Algae 

Anabaenaflos-aquae 

>1.6 0.12 42137312 Supplementali2 

Hughes and Alexander, 

1991 

>1.410 199 440803:40 Acceptable 

> 3.4 3.4 4501 16-03 Acceptable 

Ward, Magazu, and Boeri, 

2000 

>1.4 0.20 44080340 Acceptable 

Milazzo, Hugo, and Martin, 

1996 

23.2 3.2 4501 16-02 Acceptable 

Ward, Magazu, and Boeri, 

2000 

>2.3 1.2 44080338 Acceptable 

Milazzo, Hugo, and Martin, 

1996 

0.40 0.030 44080336 Acceptable 

Milazzo, Hugo, and Martin, 

1996 
Table N. Nontarget Aquatic Plant Toxicity (Tier 2) 

EGO NOEC MRIDNo. Study Classification 

Species (ppin ai) (ppm ai) AuthorNear 

Marine diatom 

Skeletonema costaturn 

0.29 0.18 44080337 Acceptable 

Milazzo, Hugo, and Martin, 

1996 

Freshwater Diatom 0.056 < 0.015 44080339 Invalid 

Navicula pelliculosa Milazzo, Hugo, and Martin, 

1996 

1 The test species is not an acceptable in US guidelines, and cell counts were not determined. 

2 Because of lack of solubility, the concentration of test material in solution during the test was uncertain. 

3. This study did not comply with GLP standards . 

No acceptable aquatic plant toxicity data are available for fluroxypyr acid. Supplemental 

data, however, indicate that it has low toxicity to green algae. Additional data are not 

required on the fluroxypyr acid for registration of products containing fluroxypyr MHE. 

Data on the toxicity of fluroxypyr MHE to aquatic plants are complete with the exception of 

data for a fi-eshwater diatom, such as Naviculapelliculosa. A new study with a fi-eshwater 

diatom is required. The test guideline for tier I1 aquatic plant testing (123-2) is not fulfilled. 

The studies with 4-amino-3,5-dichloro-6-fluro-2-methoxypyridine a degradate product 

(MRID 44080341) is not a GLP study, but it provides usable information on the toxicity of 

this degradation product of fluroxypyr MHE. 
Appendix B Terrestrial Exposure Modeling 

TREX MODEL 

T-IM( Version 1 .t 1 

December7,m 1 

This spreadsheet was developed by the Terrestrial Biology and Exposue Technical Teams. 

For infwmation or quesb'ons ccnceming this spreackheet, please contact the TerrMral -we 

Technical Team &Chairs. 

New version Nates 

711- v. 1.22 Mneau scaling factws for birds MUST be manually entered in the lrputs~lrkket. While the EFED default value 

is 1.15 it MUST also be entered if that default is desired. If novalue is provideQ the mcdel will embit warning sWements in all outpLts. 

Iftheuserdesrestohem,~q~,O~beenteredintheIrpns~. 

Body \ht?igMsfor Mallard duck and Bdmhite quail uere Wusk-3 (Dulning, 1984). 

User can opt for tesi spedes for ac& and chmic mi other than malbrd and txhhite (test animal boqrwei@t data must be provided) 

User can opt for altem bach/weiihts frm defaultsfor ewints esWished vith ithte and mallard 

lhs WR-2 data input Won in the Inputswrksheet was reqanbd to be more user-Wmdty. 

U)50 fi-2 can now be isculated for a liqd brdastapplication. 

AIl references are available in the seed treaiment worlcsheet. iWse references are also hyperlinked. 

Wmum seeding rate infmtion is nm in blue and can be adjusted by the user. 

S'lEW5 v. 1.23. A canment sheet has been x&d so that EEO ws can prod? fe&ack or pose qMm to the Tmrial Biology mi &mure Tebn'lcal Teams 

This Mue is available to EFED users only. 

1~~ v. 1.3.1. Anew sheet 'Print Resllts' was acfd to fadlitate cuning and p&ng into MS Word documents. Fwlrampamq, the mlts summary tables include toxicity and eqx6ue values 

Use of FDA's assumption that a lab raf mmes 5% of its diet cbilywas made aonal for mammalian chrmic sWes If a sWy reports both a NOAEC in ppm and a NOAn in n 

The % a.i. cell was formatted to percent. The ddations of application rate (lbs ailhe) in the lpper boa Kenap and the mean Kenaga sheets m, longer referem a Hdden o 

the applicatian rate in tern of %a.i., but is isdated in the "apflication rate" cell. 

PWitional calarhtions mre incluzkd to allow fa additional dlaracterization of the LD50-W. Anew sheet "C3anular Chamderiaikn Calcs" &estimates the nmber of granules re& 

ck6e that mki bigger a level of concern. The assodated minimtm foragng area with sufficient numher of granulest0 achieve a dose that exwdsthe w l/lM the WL 

assumpbans of feedng effidency (10°/4 50°/+ or 1 Whof granules in an area are mnslrmed). 

7/7R007 v. 1.3.1. For darifiii, percent a.i. vvds rnade a user input in the Granular Onm%rWikm Calcs sheet instead of importing the value from the lrputs sheet. No othw d-tanges we rnade 

Supporting LbcummWon 

For further mdsl information consldt the 'Usec's Guide' doament containing T-RM operating 

instluctians and badcground infcmation. UWs Qide TRM vl.3.1, Dmber 2006, USEPAOffice of Pesticide Rograms, Washington OC 

hning, J.B. 1984. Bodywhts of 686 spedes of Nmth American birds Western Bird bding Assoc. 

MonosraphNo.1. 

Fletcher, J.S, J.E Neil- and T. G Pfleegx. 1994. Literature review and evaluation of the EPAfoodchain 

(Kemga) nwnogrsun, an .nstnunentfor estimating pestid6 residues on plants Envim. Tox And 

Chem. 13(9):1383139l 

Hoerpr, F. and E.E Kerraga. 1972. Pestidde residuss m plants: correlation of representative data as a 

basis for estimation of their mgitude in the environment IN: F. Coulston and F. Corte, eds., 

Envimmental Chality wl %Safety: Chemistry, Toxicdogy and Technology. MI 1. Gewg Theime 

Publishers, Shrttgart, @many. pp. 428 

Mneau, P., BT. CdIirs, A MI. 1996. 01 the use of scaling factMs to improve interspecies extrapoldm to 

acute toxic4ty in binls. Reg. Toxicd. Fbmnxd. 2424-29 

UM, D. J. 2MX). Guidance for Wing Saeening Level Avim Risk kssmmts for Spay Applications 

of Wades OPPIEFED, USEPA 

USEPA 1993. Wldife Exposure Fadm Handxok Vdm I of II. EPN€xX@53/187a. Gffice of Research 

and Development, WsWgtm, D. C. 20460. 

USEPA 1995. &at Lakes Water Wi Technical S&pM Document for Wildlife Cfiteria 

Office of Water, Washington D.C. Doament Ntmber EPA8208095-009 

Wilii and MzIImell. 1987. Pesticide persistence on fdii. him. Ccntam. Toximl. 10032373 
TREX Millet Output Results for Avian RQs 

Avian Results - 

how TO pmvnJe nsk management w th the maxtmum posslole ,nformat on 

~t IS rewmmended that both the oose-based and wncenlrahowbased 

ROS be calculated when data are available 
TREX Millet Output for Mammalian RQs 

Mammalian Results 

Note: To provide risk management with the maximum possible information, 

it is recommended that both the dose-based and concentration-based 

RQs be calculated when data are available 

TREX Pome Fruit Output for Avian RQs 

Avian Results 
Mammalian Results 

Note: To provide risk management with the maximum possible information, 

it is recommended that both the dose-based and concentration-based 

RQs be calculated when data are available 
Appendix C LOCATES Output for Summary of Federally Listed Species 

Species Counts by State for Indicated Crops 

No species were excluded. 

Minimum of 1 Acre. 

All Medium Types Reported 

apples, pears, all 

AL, AK, AZ, AR, CA, CO, CT, DE, DC, FL, GA, HI, ID, IL, IN, IA, KS, KY, LA, ME, MD, 

MA, MI, MN, MS, MO, MT, NE, NV, NH, NJ, NM, NY, NC, ND, OH, OK, OR, PA, PR, 

RI, SC, SD, TN, TX, UT, VT, VA, WA, WV, WI, WY 

Alabama 

The taxa Amphibian has 2 species co-occurring with indicated crops. 

The taxa Bird has 3 species co-occurring with indicated crops. 

The taxa Bivalve has 30 species co-occurring with indicated crops. 

The taxa Crustacean has 1 species co-occurring with indicated crops. 

The taxa Dicot has 10 species co-occurring with indicated crops. 

The taxa Fish has 15 species co-occurring with indicated crops. 

The taxa Gastropod has 10 species co-occurring with indicated crops. 

The taxa Mammal has 4 species co-occurring with indicated crops. 

The taxa Monocot has 3 species co-occurring with indicated crops. 
The taxa Reptile has 5 species co-occurring with indicated crops. 

Arizona 

The taxa Amphibian has 2 species co-occurring with indicated crops. 

The taxa Bird has 7 species co-occurring with indicated crops. 

The taxa Dicot has 16 species co-occurring with indicated crops. 

The taxa Fish has 18 species co-occurring with indicated crops. 

The taxa Gastropod has 1 species co-occurring with indicated crops. 

The taxa Mammal has 9 species co-occurring with indicated crops. 

The taxa Monocot has 2 species co-occurring with indicated crops. 

The taxa Reptile has 2 species co-occurring with indicated crops. 

Arkansas 

The taxa Bird has 2 species co-occurring with indicated crops. 

The taxa Bivalve has 6 species co-occurring with indicated crops. 

The taxa Crustacean has 2 species co-occurring with indicated crops. 

11/8/2007 5:35:04 PM Ver. 2.10.3 Page 1 of 14 

AL, AK, AZ, AR, CA, CO, CT, DE, DC, FL, GA, HI, ID, IL, IN, IA, KS, KY, LA, ME, 

MD, MA, MI, MN, MS, MO, MT, NE, NV, NH, NJ, NM, NY, NC, ND, OH, OK, OR, PA, 

PR, RI, SC, SD, TN, TX, UT, VT, VA, WA, WV, WI, WY 

The taxa Dicot has 4 species co-occurring with indicated crops. 

The taxa Fish has 3 species co-occurring with indicated crops. 

75 
The taxa Gastropod has 1 species co-occurring with indicated crops. 

The taxa Insect has 1 species co-occurring with indicated crops. 

The taxa Mammal has 3 species co-occurring with indicated crops. 

California 

The taxa Amphibian has 6 species co-occurring with indicated crops. 

The taxa Bird has 15 species co-occurring with indicated crops. 

The taxa Crustacean has 9 species co-occurring with indicated crops. 

The taxa Dicot has 158 species co-occurring with indicated crops. 

The taxa Fish has 3 1 species co-occurring with indicated crops. 

The taxa Gastropod has 1 species co-occurring with indicated crops. 

The taxa Insect has 22 species co-occurring with indicated crops. 

The taxa Mammal has 20 species co-occurring with indicated crops. 

The taxa Monocot has 17 species co-occurring with indicated crops. 

The taxa Reptile has 8 species co-occurring with indicated crops. 

Colorado 

The taxa Bird has 2 species co-occurring with indicated crops. 

The taxa Dicot has 8 species co-occurring with indicated crops. 

The taxa Fish has 6 species co-occurring with indicated crops. 

The taxa Insect has 2 species co-occurring with indicated crops. 

76 
The taxa Mammal has 2 species co-occurring with indicated crops. 

The taxa Monocot has 1 species co-occurring with indicated crops. 

Connecticut 

The taxa Bird has 2 species co-occurring with indicated crops. 

The taxa Bivalve has 1 species co-occurring with indicated crops. 

The taxa Dicot has 1 species co-occurring with indicated crops. 

The taxa Fish has 1 species co-occurring with indicated crops. 

The taxa Insect has 1 species co-occurring with indicated crops. 

11/8/2007 5:35:04 PM Ver. 2.10.3 Page 2 of 14 

AL, AK,AZ, AR, CA, CO, CT, DE, DC, FL, GA, HI, ID, IL, IN, IA, KS, KY, LA, ME, 

MD, MA, MI, MN, MS, MO, MT, NE, NV, NH, NJ, NM, NY, NC, ND, OH, OK, OR, PA, 

PR, RI, SC, SD, TN, TX, UT, VT, VA, WA, WV, WI, WY 

The taxa Mammal has 1 species co-occurring with indicated crops. 

77 
The taxa Monocot has 1 species co-occurring with indicated crops. 

The taxa Reptile has 1 species co-occurring with indicated crops. 

Delaware 

The taxa Bird has 1 species co-occurring with indicated crops. 

The taxa Fish has 1 species co-occurring with indicated crops. 

The taxa Mammal has 1 species co-occurring with indicated crops. 

The taxa Monocot has 2 species co-occurring with indicated crops. 

The taxa Reptile has 1 species co-occurring with indicated crops. 

Florida 

The taxa Amphibian has 1 species co-occurring with indicated crops. 

The taxa Bird has 8 species co-occurring with indicated crops. 

The taxa Bivalve has 7 species co-occurring with indicated crops. 

The taxa Crustacean has 1 species co-occurring with indicated crops. 

The taxa Dicot has 23 species co-occurring with indicated crops. 

The taxa Fish has 4 species co-occurring with indicated crops. 

The taxa Insect has 1 species co-occurring with indicated crops. 

The taxa Mammal has 5 species co-occurring with indicated crops. 

The taxa Monocot has 1 species co-occurring with indicated crops. 

The taxa Reptile has 9 species co-occurring with indicated crops. 

78 
Georgia 

The taxa Amphibian has 1 species co-occurring with indicated crops. 

The taxa Bird has 4 species co-occurring with indicated crops. 

The taxa Bivalve has 15 species co-occurring with indicated crops. 

The taxa Dicot has 8 species co-occurring with indicated crops. 

The taxa Fish has 8 species co-occurring with indicated crops. 

The taxa Insect has 1 species co-occurring with indicated crops. 

The taxa Mammal has 2 species co-occurring with indicated crops. 

The taxa Monocot has 6 species co-occurring with indicated crops. 

1 1/8/2007 5:35:04 PM Ver. 2.10.3 Page 3 of 14 

AL, AK, AZ, AR, CA, CO, CT, DE, DC, FL, GA, HI, ID, IL, IN, IA, KS, KY, LA, ME, 

MD, MA, MI, MN, MS, MO, MT, NE, NV, NH, NJ, NM, NY, NC, ND, OH, OK, OR, PA, 

PR,RI, SC, SD,TN,TX,UT,VT,VA, WA, WV, WI, WY 

The taxa Reptile has 2 species co-occurring with indicated crops. 

Hawaii 

The taxa Bird has 21 species co-occurring with indicated crops. 

The taxa Dicot has 113 species co-occurring with indicated crops. 

The taxa Insect has 1 species co-occurring with indicated crops. 

The taxa Mammal has 1 species co-occurring with indicated crops. 

79 
The taxa Monocot has 11 species co-occurring with indicated crops. 

The taxa Reptile has 2 species co-occurring with indicated crops. 

Idaho 

The taxa Bird has 1 species co-occurring with indicated crops. 

The taxa Dicot has 3 species co-occurring with indicated crops. 

The taxa Fish has 8 species co-occurring with indicated crops. 

The taxa Gastropod has 5 species co-occurring with indicated crops. 

The taxa Mammal has 4 species co-occurring with indicated crops. 

Illinois 

The taxa Bird has 2 species co-occurring with indicated crops. 

The taxa Bivalve has 7 species co-occurring with indicated crops. 

The taxa Crustacean has 1 species co-occurring with indicated crops. 

The taxa Dicot has 7 species co-occurring with indicated crops. 

The taxa Fish has 1 species co-occurring with indicated crops. 

The taxa Gastropod has 1 species co-occurring with indicated crops. 

The taxa Insect has 2 species co-occurring with indicated crops. 

The taxa Mammal has 2 species co-occurring with indicated crops. 

The taxa Monocot has 2 species co-occurring with indicated crops. 

Indiana 
The taxa Bird has 2 species co-occurring with indicated crops. 

The taxa Bivalve has 11 species co-occurring with indicated crops. 

The taxa Dicot has 4 species co-occurring with indicated crops. 

The taxa Insect has 2 species co-occurring with indicated crops. 

11/8/2007 5:35:04 PM Ver. 2.10.3 Page4 of 14 

AL, AK, AZ, AR, CA, CO, CT, DE, DC, FL, GA, HI, ID, IL, IN, IA, KS, KY, LA, ME, 

MD, MA, MI, MN, MS, MO, MT, NE, NV, NH, NJ, NM, NY, NC, ND, OH, OK, OR, PA, 

PR, RI, SC, SD, TN, TX, UT, VT, VA, WA, WV, WI, WY 

The taxa Mammal has 2 species co-occurring with indicated crops. 

The taxa Monocot has 1 species co-occurring with indicated crops. 

The taxa Reptile has 1 species co-occurring with indicated crops. 

Iowa 

The taxa Bird has 2 species co-occurring with indicated crops. 

The taxa Bivalve has 2 species co-occurring with indicated crops. 

The taxa Dicot has 3 species co-occurring with indicated crops. 

The taxa Fish has 2 species co-occurring with indicated crops. 

The taxa Gastropod has 1 species co-occurring with indicated crops. 

The taxa Mammal has 1 species co-occurring with indicated crops. 

The taxa Monocot has 2 species co-occurring with indicated crops. 
Kansas 

The taxa Bird has 3 species co-occurring with indicated crops. 

The taxa Bivalve has 3 species co-occurring with indicated crops. 

11/8/2007 5:35:04 PM Ver. 2.10.3 Page 5 of 14 

The taxa Dicot has 1 species co-occurring with indicated crops. 

The taxa Fish has 4 species co-occurring with indicated crops. 

The taxa Insect has 1 species co-occurring with indicated crops. 

The taxa Mammal has 2 species co-occurring with indicated crops. 

The taxa Monocot has 1 species co-occurring with indicated crops. 

Kentucky 

The taxa Bird has 6 species co-occurring with indicated crops. 

The taxa Bivalve has 22 species co-occurring with indicated crops. 

The taxa Crustacean has 1 species co-occurring with indicated crops. 

The taxa Dicot has 10 species co-occurring with indicated crops. 

The taxa Fish has 4 species co-occurring with indicated crops. 

The taxa Insect has 1 species co-occurring with indicated crops. 

The taxa Mammal has 3 species co-occurring with indicated crops. 

Louisiana 

The taxa Bird has 4 species co-occurring with indicated crops. 
AL, AK, AZ, AR, CA, CO, CT, DE, DC, FL, GA, HI, ID, IL, IN, IA, KS, KY, LA, ME, 

MD, MA, MI, MN, MS, MO, MT, NE, NV, NH, NJ, NM, NY, NC, ND, OH, OK, OR, PA, 

PR, RI, SC, SD, TN, TX, UT, VT, VA, WA, WV, WI, WY 

The taxa Dicot has 2 species co-occurring with indicated crops. 

The taxa Fish has 2 species co-occurring with indicated crops. 

The taxa Mammal has 1 species co-occurring with indicated crops. 

The taxa Reptile has 7 species co-occurring with indicated crops. 

Maine 

The taxa Bird has 2 species co-occurring with indicated crops. 

The taxa Dicot has 1 species co-occurring with indicated crops. 

The taxa Fish has 2 species co-occurring with indicated crops. 

The taxa Mammal has 1 species co-occurring with indicated crops. 

The taxa Monocot has 2 species co-occurring with indicated crops. 

Maryland 

The taxa Bird has 1 species co-occurring with indicated crops. 

The taxa Bivalve has 1 species co-occurring with indicated crops. 

The taxa Dicot has 4 species co-occurring with indicated crops. . 

The taxa Fish has 2 species co-occurring with indicated crops. 

The taxa Insect has 2 species co-occurring with indicated crops. 

83 
The taxa Mammal has 2 species co-occurring with indicated crops. 

The taxa Monocot has 2 species co-occurring with indicated crops. 

The taxa Reptile has 1 species co-occurring with indicated crops. 

Massachusetts 

The taxa Bird has 3 species co-occurring with indicated crops. 

The taxa Dicot has 1 species co-occurring with indicated crops. 

The taxa Fish has 1 species co-occurring with indicated crops. 

The taxa Insect has 3 species co-occurring with indicated crops. 

The taxa Mammal has 1 species co-occurring with indicated crops. 

The taxa Monocot has 2 species co-occurring with indicated crops. 

The taxa Reptile has 2 species co-occurring with indicated crops. 

Michigan 

The taxa Bird has 2 species co-occurring with indicated crops. 

11/8/2007 5:35:04 PM Ver. 2.10.3 Page 6 of 14 

AL, AK, AZ, AR, CA, CO, CT, DE, DC, FL, GA, HI, ID, IL, IN, IA, KS, KY, LA, ME, 

MD, MA, MI, MN, MS, MO, MT, NE, NV, NH, NJ, NM, NY, NC, ND, OH, OK, OR, PA, 

PR, RI, SC, SD, TN, TX, UT, VT, VA, WA, WV, WI, WY 

The taxa Bivalve has 2 species co-occurring with indicated crops. 

The taxa Dicot has 4 species co-occurring with indicated crops. 

84 
The taxa Insect has 4 species co-occurring with indicated crops. 

The taxa Mammal has 3 species co-occurring with indicated crops. 

The taxa Monocot has 3 species co-occurring with indicated crops. 

The taxa Reptile has 1 species co-occurring with indicated crops. 

Minnesota 

The taxa Bird has 1 species co-occurring with indicated crops. 

The taxa Bivalve has 2 species co-occurring with indicated crops. 

The taxa Dicot has 2 species co-occurring with indicated crops. 

The taxa Fish has 1 species co-occurring with indicated crops. 

The taxa Insect has 1 species co-occurring with indicated crops. 

The taxa Mammal has 2 species co-occurring with indicated crops. 

The taxa Monocot has 2 species co-occurring with indicated crops. 

Mississippi 

The taxa Amphibian has 1 species co-occurring with indicated crops. 

The taxa Bird has 5 species co-occurring with indicated crops. 

The taxa Bivalve has 8 species co-occurring with indicated crops. 

The taxa Dicot has 2 species co-occurring with indicated crops. 

The taxa Fish has 3 species co-occurring with indicated crops. 

The taxa Mammal has 3 species co-occurring with indicated crops. 

85 
The taxa Reptile has 7 species co-occurring with indicated crops. 

Missouri 

The taxa Bird has 2 species co-occurring with indicated crops. 

The taxa Bivalve has 6 species co-occurring with indicated crops. 

The taxa Dicot has 7 species co-occurring with indicated crops. 

The taxa Fish has 6 species co-occurring with indicated crops. 

The taxa Insect has 2 species co-occurring with indicated crops. 

The taxa Mammal has 2 species co-occurring with indicated crops. 

1 1/8/2007 5:35:04 PM Ver. 2.10.3 Page 7 of 14 

AL, AK, AZ, AR, CA, CO, CT, DE, DC, FL, GA, HI, ID, IL, IN, IA, KS, KY, LA, ME, 

MD, MA, MI, MN, MS, MO, MT, NE, NV, NH, NJ, NM, NY, NC, ND, OH, OK, OR, PA, 

PR, RI, SC, SD, TN, TX, UT, VT, VA, WA, WV, WI, WY 

The taxa Monocot has 1 species co-occurring with indicated crops. 

Montana 

The taxa Bird has 3 species co-occurring with indicated crops. 

The taxa Dicot has 2 species co-occurring with indicated crops. 

The taxa Fish has 5 species co-occurring with indicated crops. 

The taxa Mammal has 3 species co-occurring with indicated crops. 

Nebraska 
The taxa Bird has 3 species co-occurring with indicated crops. 

The taxa Dicot has 1 species co-occurring with indicated crops. 

The taxa Fish has 2 species co-occurring with indicated crops. 

The taxa Insect has 1 species co-occurring with indicated crops. 

The taxa Mammal has 1 species co-occurring with indicated crops. 

The taxa Monocot has 1 species co-occurring with indicated crops. 

Nevada 

The taxa Bird has 2 species co-occurring with indicated crops. 

The taxa Dicot has 8 species co-occurring with indicated crops. 

The taxa Fish has 23 species co-occurring with indicated crops. 

The taxa Insect has 2 species co-occurring with indicated crops. 

The taxa Monocot has 1 species co-occurring with indicated crops. 

The taxa Reptile has 1 species co-occurring with indicated crops. 

New Hampshire 

The taxa Bivalve has 1 species co-occurring with indicated crops. 

The taxa Dicot has 1 species co-occurring with indicated crops. 

The taxa Insect has 1 species co-occurring with indicated crops. 

The taxa Mammal has 1 species co-occurring with indicated crops. 

The taxa Monocot has 1 species co-occurring with indicated crops. 

87 
New Jersey 

The taxa Bird has 2 species co-occurring with indicated crops. 

The taxa Dicot has 2 species co-occurring with indicated crops. 

11/8/2007 5:35:05 PM Ver. 2.10.3 Page 8 of 14 

AL, AK, AZ, AR, CA, CO, CT, DE, DC, FL, GA, HI, ID, IL, lN, IA, KS, KY, LA, ME, 

MD, MA, MI, MN, MS, MO, MT, NE, NV, NH, NJ, NM, NY, NC, ND, OH, OK, OR, PA, 

PR, RI, SC, SD, TN, TX, UT, VT, VA, WA, WV, WI, WY 

The taxa Fish has 1 species co-occurring with indicated crops. 

The taxa Mammal has 1 species co-occurring with indicated crops. 

The taxa Monocot has 3 species co-occurring with indicated crops. 

The taxa Reptile has 1 species co-occurring with indicated crops. 

New Mexico 

The taxa Amphibian has 1 species co-occurring with indicated crops. 

The taxa Bird has 6 species co-occurring with indicated crops. 

The taxa Crustacean has 2 species co-occurring with indicated crops. 

The taxa Dicot has 11 species co-occurring with indicated crops. 

The taxa Fish has 13 species co-occurring with indicated crops. 

The taxa Gastropod has 5 species co-occurring with indicated crops. 

The taxa Mammal has 2 species co-occurring with indicated crops. 

88 
New York 

The taxa Bird has 2 species co-occurring with indicated crops. 

The taxa Bivalve has 1 species co-occurring with indicated crops. 

The taxa Dicot has 4 species co-occurring with indicated crops. 

The taxa Fish has 1 species co-occurring with indicated crops. 

The taxa Gastropod has 1 species co-occurring with indicated crops. 

The taxa Insect has 1 species co-occurring with indicated crops. 

The taxa Mammal has 1 species co-occurring with indicated crops. 

The taxa Monocot has 1 species co-occurring with indicated crops. 

The taxa Reptile has 1 species co-occurring with indicated crops. 

North Carolina 

The taxa Arachnid has 1 species co-occurring with indicated crops. 

The taxa Bird has 4 species co-occurring with indicated crops. 

The taxa Bivalve has 8 species co-occurring with indicated crops. 

The taxa Dicot has 21 species co-occurring with indicated crops. 

The taxa Fish has 4 species co-occurring with indicated crops. 

The taxa Gastropod has 1 species co-occurring with indicated crops. 

1 1/8/2007 5:35:05 PM Ver. 2.10.3 Page 9 of 14 
AL, AK, AZ, AR, CA, CO, CT, DE, DC, FL, GA, HI, ID, IL, IN, IA, KS, KY, LA, ME, 

MD, MA, MI, MN, MS, MO, MT, NE, NV, NH, NJ, NM, NY, NC, ND, OH, OK, OR, PA, 

PR, RI, SC, SD, TN, TX, UT, VT, VA, WA, WV, WI, WY 

The taxa Insect has 1 species co-occurring with indicated crops. 

The taxa Mammal has 4 species co-occurring with indicated crops. 

The taxa Monocot has 5 species co-occurring with indicated crops. 

The taxa Reptile has 5 species co-occurring with indicated crops. 

North Dakota 

The taxa Bird has 1 species co-occurring with indicated crops. 

The taxa Monocot has 1 species co-occurring with indicated crops. 

Ohio 

The taxa Bird has 1 species co-occurring with indicated crops. 

The taxa Bivalve has 6 species co-occurring with indicated crops. 

The taxa Dicot has 4 species co-occurring with indicated crops. 

The taxa Fish has 1 species co-occurring with indicated crops. 

The taxa Insect has 4 species co-occurring with indicated crops. 

The taxa Mammal has 2 species co-occurring with indicated crops. 

The taxa Monocot has 2 species co-occurring with indicated crops. 

The taxa Reptile has 2 species co-occurring with indicated crops. 

Oklahoma 
The taxa Bird has 6 species co-occurring with indicated crops. 

The taxa Bivalve has 2 species co-occurring with indicated crops. 

The taxa Fish has 4 species co-occurring with indicated crops. 

The taxa Insect has 1 species co-occurring with indicated crops. 

The taxa Mammal has 3 species co-occurring with indicated crops. 

The taxa Monocot has 2 species co-occurring with indicated crops. 

Oregon 

The taxa Bird has 4 species co-occurring with indicated crops. 

The taxa Crustacean has 1 species co-occurring with indicated crops. 

The taxa Dicot has 11 species co-occurring with indicated crops. 

The taxa Fish has 19 species co-occurring with indicated crops. 

The taxa Insect has 2 species co-occurring with indicated crops. 

11/8/2007 5:35:05 PM Ver. 2.10.3 Page 10 of 14 

AL, AK, AZ, AR, CA, CO, CT, DE, DC, FL, GA, HI, ID, IL, IN, LA, KS, KY, LA, ME, 

MD, MA, MI, MN, MS, MO, MT, NE, NV, NH, NJ, NM, NY, NC, ND, OH, OK, OR, PA, 

PR, RI, SC, SD, TN, TX, UT, VT, VA, WA, WV, WI, WY 

The taxa Mammal has 1 species co-occurring. with indicated crops. 

The taxa Monocot has 2 species co-occurring with indicated crops. 

Pennsylvania 

9 1 
The taxa Bird has 1 species co-occurring with indicated crops. 

The taxa Bivalve has 2 species co-occurring with indicated crops. 

The taxa Mammal has 2 species co-occurring with indicated crops. 

The taxa Monocot has 2 species co-occurring with indicated crops. 

The taxa Reptile has 1 species co-occurring with indicated crops. 

Rhode Island 

The taxa Bird has 1 species co-occurring with indicated crops. 

The taxa Dicot has 1 species co-occurring with indicated crops. 

The taxa Fish has 1 species co-occurring with indicated crops. 

The taxa Insect has 1 species co-occurring with indicated crops. 

The taxa Mammal has 1 species co-occurring with indicated crops. 

The taxa Monocot has 1 species co-occurring with indicated crops. 

South Carolina 

The taxa Amphibian has 1 species co-occurring with indicated crops. 

The taxa Bird has 4 species co-occurring with indicated crops. 

The taxa Bivalve has 1 species co-occurring with indicated crops. 

The taxa Dicot has 12 species co-occurring with indicated crops. 

The taxa Fish has 1 species co-occurring with indicated crops. 

The taxa Mammal has 1 species co-occurring with indicated crops. 

92 
The taxa Monocot has 6 species co-occurring with indicated crops. 

The taxa Reptile has 5 species co-occurring with indicated crops. 

South Dakota 

The taxa Bird has 3 species co-occurring with indicated crops. 

The taxa Fish has 2 species co-occurring with indicated crops. 

The taxa Insect has 1 species co-occurring with indicated crops. 

The taxa Mammal has 1 species co-occurring with indicated crops. 

11/8/2007 5:35:05 PM Ver. 2.10.3 Page 11 of 14 

AL, AK, AZ, AR, CA, CO, CT, DE, DC, FL, GA, HI, ID, IL, IN, IA, KS, KY, LA, ME, 

MD, MA, MI, MN, MS, MO, MT, NE, NV, NH, NJ, NM, NY, NC, ND, OH, OK, OR, PA, 

PR, Rl, SC, SD, TN, TX, UT, VT, VA, WA, WV, WI, WY 

The taxa Monocot has 1 species co-occurring with indicated crops. 

Tennessee 

The taxa Arachnid has 1 species co-occurring with indicated crops. 

The taxa Bird has 3 species co-occurring with indicated crops. 

The taxa Bivalve has 37 species co-occurring with indicated crops. 

The taxa Crustacean has 1 species co-occurring with indicated crops. 

The taxa Dicot has 16 species co-occurring with indicated crops. 

The taxa Fish has 16 species co-occurring with indicated crops. 

93 
The taxa Gastropod has 2 species co-occurring with indicated crops. 

The taxa Mammal has 3 species co-occurring with indicated crops. 

The taxa Monocot has 2 species co-occurring with indicated crops. 

Texas 

The taxa Amphibian has 4 species co-occurring with indicated crops. 

The taxa Arachnid has 10 species co-occurring with indicated crops. 

The taxa Bird has 12 species co-occurring with indicated crops. 

The taxa Crustacean has 1 species co-occurring with indicated crops. 

The taxa Dicot has 20 species co-occurring with indicated crops. 

The taxa Fish has 7 species co-occurring with indicated crops. 

The taxa Insect has 9 species co-occurring with indicated crops. 

The taxa Mammal has 5 species co-occurring with indicated crops. 

The taxa Monocot has 3 species co-occurring with indicated crops. 

The taxa Reptile has 6 species co-occurring with indicated crops. 

Utah 

The taxa Bird has 2 species co-occurring with indicated crops. 

The taxa Dicot has 22 species co-occurring with indicated crops. 

The taxa Fish has 8 species co-occurring with indicated crops. 

The taxa Mammal has 2 species co-occurring with indicated crops. 

94 
The taxa Monocot has 2 species co-occurring with indicated crops. 

The taxa Reptile has 1 species co-occurring with indicated crops. 

11/8/2007 5:35:05 PM Ver. 2.10.3 Page 12 of 14 

AL, AK, AZ, AR, CA, CO, CT, DE, DC, FL, GA, HI, ID, IL, IN, IA, KS, KY, LA, ME, 

MD, MA, MI, MN, MS, MO, MT, NE, NV, NH, NJ, NM, NY, NC, ND, OH, OK, OR, PA, 

PR, RI, SC, SD, TN, TX, UT, VT, VA, WA, WV, WI, WY 

Vermont 

The taxa Bivalve has 1 species co-occurring with indicated crops. 

The taxa Dicot has 1 species co-occurring with indicated crops. 

The taxa Mammal has 1 species co-occurring with indicated crops. 

The taxa Monocot has 1 species co-occurring with indicated crops. 

Virginia 

The taxa Amphibian has 1 species co-occurring with indicated crops. 

The taxa Bird has 2 species co-occurring with indicated crops. 

The taxa Bivalve has 21 species co-occurring with indicated crops. 

The taxa Crustacean has 2 species co-occurring with indicated crops. 

The taxa Dicot has 13 species co-occurring with indicated crops. 

The taxa Fish has 7 species co-occurring with indicated crops. 

The taxa Gastropod has 1 species co-occurring with indicated crops. 

95 
The taxa Insect has 3 species co-occurring with indicated crops. 

The taxa Mammal has 5 species co-occurring with indicated crops. 

The taxa Monocot has 4 species co-occurring with indicated crops. 

The taxa Reptile has 1 species co-occurring with indicated crops. 

Washington 

The taxa Bird has 4 species co-occurring with indicated crops. 

The taxa Dicot has 7 species co-occurring with indicated crops. 

The taxa Fish has 19 species co-occurring with indicated crops. 

The taxa Mammal has 5 species co-occurring with indicated crops. 

West Virginia 

The taxa Amphibian has 1 species co-occurring with indicated crops. 

The taxa Bivalve has 5 species co-occurring with indicated crops. 

The taxa Dicot has 4 species co-occurring with indicated crops. 

The taxa Gastropod has 1 species co-occurring with indicated crops. 

The taxa Mammal has 5 species co-occurring with indicated crops. 

The taxa Monocot has 1 species co-occurring with indicated crops. 

1 1/8/2007 5:35:05 PM Ver. 2.10.3 Page 13 of 14 

AL, AK, AZ, AR, CA, CO, CT, DE, DC, FL, GA, HI, ID, IL, IN, IA, KS, KY, LA, ME, 

MD, MA, MI, MN, MS, MO, MT, NE, NV, NH, NJ, NM, NY, NC, ND, OH, OK, OR, PA, 

PR,RI, SC, SD,TN,TX,UT,VT,VA, WA, WV, WI, WY 

96 
Wisconsin 

The taxa Bird has 3 species co-occurring with indicated crops. 

The taxa Bivalve has 2 species co-occurring with indicated crops. 

The taxa Dicot has 4 species co-occurring with indicated crops. 

The taxa Insect has 2 species co-occurring with indicated crops. 

The taxa Mammal has 2 species co-occurring with indicated crops. 

The taxa Monocot has 2 species co-occurring with indicated crops. 

Wyoming 

The taxa Dicot has 1 species co-occurring with indicated crops. 

The taxa Mammal has 3 species co-occurring with indicated crops. 

No species were excluded. 

Dispersed species included in report. 

11/8/2007 5:35:05 PM Ver. 2.10.3 Page 14 of 14 
Species Counts by State for Indicated Crops 

No species were excluded. 

Minimum of 1 Acre. 

All Medium Types Reported 

proso millet 

AL, AK, AZ, AR, CA, CO, CT, DE, DC, FL, GA, HI, ID, IL, IN, IA, KS, KY, LA, ME, 

MD, MA, MI, MN, MS, MO, MT, NE, NV, NH, NJ, NM, NY, NC, ND, OH, OK, OR, PA, 

PR, RI, SC, SD, TN, TX, UT, VT, VA, WA, WV, WI, WY 

California 

The taxa Bird has 1 species co-occurring with indicated crops. 

The taxa Dicot has 1 species co-occurring with indicated crops. 

The taxa Fish has 2 species co-occurring with indicated crops. 

The taxa Insect has 1 species co-occurring with indicated crops. 

Colorado 

The taxa Bird has 1 species co-occurring with indicated crops. 

The taxa Dicot has 3 species co-occurring with indicated crops. 

The taxa Fish has 3 species co-occurring with indicated crops. 

The taxa Mammal has 2 species co-occurring with indicated crops. 

98 
The taxa Monocot has 1 species co-occurring with indicated crops. 

Florida 

The taxa Bird has 4 species co-occurring with indicated crops. 

The taxa Bivalve has 1 species co-occurring with indicated crops. 

The taxa Crustacean has 1 species co-occurring with indicated crops. 

The taxa Dicot has 4 species co-occurring with indicated crops. 

The taxa Fish has 1 species co-occurring with indicated crops. 

The taxa Mammal has 1 species co-occurring with indicated crops. 

The taxa Reptile has 5 species co-occurring with indicated crops. 

Georgia 

The taxa Bird has 2 species co-occurring with indicated crops. 

The taxa Bivalve has 5 species co-occurring with indicated crops. 

The taxa Dicot has 4 species co-occurring with indicated crops. 

The taxa Fish has 1 species co-occurring with indicated crops. 

11/9/2007 9:04:04 AM Ver. 2.10.3 Page 1 of 4 

AL, AK, AZ, AR, CA, CO, CT, DE, DC, FL, GA, HI, ID, IL, IN, IA, KS, KY, LA, ME, 

MD, MA, MI, MN, MS, MO, MT, NE, NV, NH, NJ, NM, NY, NC, ND, OH, OK, OR, PA, 

PR, RI, SC, SD, TN, TX, UT, VT, VA, WA, WV, WI, WY 

The taxa Insect has 1 species co-occurring with indicated crops. 
The taxa Mammal has 1 species co-occurring with indicated crops. 

The taxa Monocot has 1 species co-occurring with indicated crops. 

The taxa Reptile has 1 species co-occurring with indicated crops. 

Illinois 

The taxa Dicot has 1 species co-occurring with indicated crops. 

The taxa Mammal has 1 species co-occurring with indicated crops. 

Iowa 

The taxa Dicot has 1 species co-occurring with indicated crops. 

The taxa Mammal has 1 species co-occurring with indicated crops. 

The taxa Monocot has 2 species co-occurring with indicated crops. 

Kansas 

The taxa Bird has 1 species co-occurring with indicated crops. 

The taxa Dicot has 1 species co-occurring with indicated crops. 

The taxa Fish has 1 species co-occurring with indicated crops. 

The taxa Mammal has 2 species co-occurring with indicated crops. 

The taxa Monocot has 1 species co-occurring with indicated crops. 

Michigan 

The taxa Insect has 1 species co-occurring with indicated crops. 

Minnesota 
The taxa Bird has 1 species co-occurring with indicated crops. 

The taxa Mammal has 2 species co-occurring with indicated crops. 

The taxa Monocot has 1 species co-occurring with indicated crops. 

Mississippi 

The taxa Mammal has 1 species co-occurring with indicated crops. 

The taxa Reptile has 1 species co-occurring with indicated crops. 

Montana 

The taxa Bird has 3 species co-occurring with indicated crops. 

11/9/2007 9:04:04 AM Ver. 2.10.3 Page 2 of 4 

AL, AK, AZ, AR, CA, CO, CT, DE, DC, FL, GA, HI, ID, IL, IN, IA, KS, KY, LA, ME, 

MD, MA, MI, MN, MS, MO, MT, NE, NV, NH, NJ, NM, NY, NC, ND, OH, OK, OR, PA, 

PR, RI, SC, SD, TN, TX, UT, VT, VA, WA, WV, WI, WY 

The taxa Dicot has 2 species co-occurring with indicated crops. 

The taxa Fish has 4 species co-occurring with indicated crops. 

The taxa Mammal has 3 species co-occurring with indicated crops. 

Nebraska 

The taxa Bird has 3 species co-occurring with indicated crops. 

The taxa Dicot has 2 species co-occurring with indicated crops. 
The taxa Mammal has 1 species co-occurring with indicated crops. 

North Carolina 

The taxa Bird has 1 species co-occurring with indicated crops. 

The taxa Bivalve has 4 species co-occurring with indicated crops. 

The taxa Dicot has 1 species co-occurring with indicated crops. 

The taxa Fish has 1 species co-occurring with indicated crops. 

The taxa Monocot has 4 species co-occurring with indicated crops. 

North Dakota 

The taxa Bird has 3 species co-occurring with indicated crops. 

The taxa Fish has 1 species co-occurring with indicated crops. 

The taxa Monocot has 1 species co-occurring with indicated crops. 

Ohio 

The taxa Dicot has 1 species co-occurring with indicated crops. 

The taxa Insect has 1 species co-occurring with indicated crops. 

The taxa Mammal has 1 species co-occurring with indicated crops. 

Oklahoma 

The taxa Bird has 4 species co-occurring with indicated crops. 

The taxa Fish has 1 species co-occurring with indicated crops. 

South Dakota 
The taxa Bird has 3 species co-occurring with indicated crops. 

The taxa Fish has 2 species co-occurring with indicated crops. 

The taxa Insect has 1 species co-occurring with indicated crops. 

The taxa Mammal has 1 species co-occurring with indicated crops. 

11/9/2007 9:04:04 AM Ver. 2.10.3 Page 3 of 4 

AL, AK, AZ, AR, CA, CO, CT, DE, DC, FL, GA, HI, ID, IL, IN, IA, KS, KY, LA, ME, 

MD, MA, MI, MN, MS, MO, MT, NE, NV, NH, NJ, NM, NY, NC, ND, OH, OK, OR, PA, 

PR, RI, SC, SD, TN, TX, UT, VT, VA, WA, WV, WI, WY 

The taxa Monocot has 1 species co-occurring with indicated crops. 

Texas 

The taxa Bird has 1 species co-occurring with indicated crops. 

Wisconsin 

The taxa Bird has 1 species co-occurring with indicated crops. 

The taxa Dicot has 1 species co-occurring with indicated crops. 

The taxa Insect has 2 species co-occurring with indicated crops. 

The taxa Monocot has 1 species co-occurring with indicated crops. 

Wyoming 

The taxa Dicot has 1 species co-occurring with indicated crops. 

The taxa Mammal has 2 species co-occurring with indicated crops. 

103 
No species were excluded. 

Dispersed species included in report. 

11/9/2007 9:04:04 AM Ver. 2.10.3 Page 4 of 4 
Appendix D 

Ecotoxicity Categories for Terrestrial and Aquatic Organisms 

Avian 

Acute Oral Dietary 

Concentration (mg/kg) Toxicity Category Concentration @pm) Toxicity Category 

<lo very highly toxic <50 very highly toxic 

10-50 highly toxic 50-500 highly toxic 

5 1-500 moderately toxic 501-1000 moderately toxic 

501-2000 slightly toxic 1001-5000 slightly toxic 

>2000 practically nontoxic 25000 practically nontoxic 

Aquatic Organisms: Acute 

Concentration (ppm) Toxicity Category 

<O. 1 very highly toxic 

0.1 - 1 highly toxic 

>1- 10 moderately toxic 

>10 - 100 slightly toxic 

>lo0 practically nontoxic 

-- 

Wild Mammals: Acute Oral 

Concentration (mg/kg) Toxicity Category 

<lo very highly toxic 

10 - 50 highly toxic 

51 - 500 moderately toxic 

501 - 2000 slightly toxic 

>2000 practically nontoxic 

Non-Target Insects: Acute Toxicity 

Concentration (@bee) Toxicity Category 

<2 highly toxic 

2- 11 moderately toxic 

>11 practically nontoxic 
Appendix E PRZM-EXAMS Output Files 

Pome Fruit : 

stored as STAR-NC.out 

Chemical: fluroxypyr 

PRZM environment: NCappleC.txt modified Satday, 12 October 2002 at 

16:09:36 

EXAMS environment: pond298.e~~ modified Thuday, 29 August 2002 at 

16:33:30 

Metfile: w03812.dvf modified Wedday, 3 July 2002 at 09:05:50 

Water segment concentrations (ppb) 

Year 

1965 

1966 

1967 

1968 

1969 

1970 

1971 

1972 

1973 

1974 

1975 

1976 

1977 

1978 

1979 

1980 

1981 

19 82 

1983 

1984 

1985 

1986 

1987 

1988 

1989 

1990 

Peak 96 hr 21 Day 60 Day 90 Day Yearly 

0.5647 0.4521 0.236 0.1297 0.08803 0.02176 

14.12 11.12 5.299 2.065 1.381 0.3411 

3.796 3.35 1.74 0.7453 0.5072 0.1256 

5.959 4.761 2.251 0.9022 0.6055 0.1492 

0.5653 0.461 0.2629 0.1284 0.0862 0.02134 

1.012 0.8171 0.3949 0.1785 0.1208 0.03028 

0.6613 0.5321 0.2683 0.1072 0.07235 0.01788 

1.687 1.353 0.6366 0.2899 0.2146 0.05309 

8.098 6.42 2.931 1.173 0.7861 0.1941 

7.47 6.073 2.965 1.167 0.7803 0.1926 

0.6038 0.4885 0.2524 0.142 0.0957 0.0237 

1.337 1.08 0.7338 0.3498 0.2352 0.05793 

2.162 1.738 0.8226 0.3736 0.2517 0.0622 

3.578 2.883 1.44 0.5802 0.3885 0.09595 

0.5807 0.4711 0.2253 0.1256 0.08545 0.02114 

0.5078 0.4157 0.2079 0.1232 0.08874 0.02197 

0.28 0.2282 0.1121 0.04486 0.03432 0.0105 

0.28 0.2248 0.1267 0.05545 0.0432 0.01124 

1.182 0.9672 0.5066 0.2256 0.1601 0.03972 

1.404 1.136 0.7825 0.3649 0.2449 0.06037 

6.613 5.341 2.567 1.04 0.7023 0.1735 

1.031 0.834 0.4046 0.2057 0.1383 0.03423 

0.868 0.7055 0.3469 0.164 0.1167 0.02897 

0.2943 0.2399 0.1253 0.08529 0.06247 0.01553 

4.356 3.481 1.649 0.7225 0.4869 0.1204 

11.7 9.503 4.585 1.812 1.227 0.3033 

Sorted results 

Prob. Peak 96 hr 21 Day 60 Day 90 Day Yearly 

0.037037037037037 14.12 11.12 5.299 2.065 1.381 0.3411 

0.0740740740740741 11.7 9.503 4.585 1.812 1.227 0.3033 

0.111111111111111 8.098 6.42 2.965 1.173 0.7861 0.1941 

0.148148148148148 7.47 6.073 2.931 1.167 0.7803 0.1926 

0.185185185185185 6.613 5.341 2.567 1.04 0.7023 0.1735 

0.222222222222222 5.959 4.761 2.251 0.9022 0.6055 0.1492 

0.259259259259259 4.356 3.481 1.74 0.7453 0.5072 0.1256 

0.296296296296296 3.796 3.35 1.649 0.7225 0.4869 0.1204 

0.333333333333333 3.578 2.883 1.44 0.5802 0.3885 0.09595 

0.37037037037037 2.162 1.738 0.8226 0.3736 0.2517 0.0622 

0.407407407407407 1.687 1.353 0.7825 0.3649 0.2449 0.06037 

0.444444444444444 1.404 1.136 0.7338 0.3498 0.2352 0.05793 
0.1 9.1786 7.3449 3.451 1.3647 0.91837 0.22686 

Average of yearly averages: 

0.0856769230769231 

Inputs generated by pe4.pl - 8-August-2003 

Data used for this run: 

I Output File: STAR-NC 

Metf ile: w03812.dvf 

PRZM scenario: NCappleC.txt 

EXAMS environment file: pond298.exv 

Chemical Name: f luroxypyr 

Description Variable Name Value Units Comments 

Molecular weight mwt 255.03 g/mol 

Henry's Law Const. henry 0.0005 atm-mA3/mol 

Vapor Pressure vapr 9.43-7 torr 

Solubility sol 79500 mg/L 

Kd Kd mg/L 

Koc Koc 68 mg/L 

~hotolysis half -1if e kdp 0 days Half-life 

Aerobic Aquatic Metabolism kbacw 42 days Halfife 

Anaerobic Aquatic Metabolism kbacs 24 days Halfife 

Aerobic Soil Metabolism asm 14 days Halfife 

Hydrolysis: pH 5 0 days Half-life 

Hydrolysis: pH 7 0 days Half-life 

Hydrolysis: pH 9 0 days Half-life 

Method : CAM 2 integer See PRZM manual 

Incorporation Depth: DEPI cm 

Application Rate: TAPP 0.56 kg/ha 
Application Efficiency: APPEFF 0.99 fraction 

Spray Drift DRFT 0.01 fraction of application rate applied to pond 

Application Date Date 1-8 dd/mm or dd/mmm or dd-mm or dd-m 

Record 17: FILTRA 

IPSCND 1 

UPTKF 

Record 18: PLVKRT 

PLDKRT 

FEXTRC 0.5 

Flag for Index Res. Run IR Pond 

Flag for runoff calc. RUNOFF none none, monthly or total(average 

of entire run) 
Millet: 

stored as STAR-TXs.out 

Chemical: fluroxypyr 

PRZM environment: TXsorghumOP.txt modified Satday, 12 October 2002 at 

17:29:44 

EXAMS environment: pond298.e~~ modified Thuday, 29 August 2002 at 

16:33:30 

Metfile: w13958.dvf modified Wedday, 3 July 2002 at 09:06:24 

Water segment concentrations (ppb) 

Year 

1961 

1962 

1963 

1964 

1965 

1966 

1967 

1968 

1969 

1970 

1971 

1972 

1973 

1974 

1975 

1976 

1977 

1978 

1979 

1980 

1981 

1982 

1983 

1984 

1985 

1986 

1987 

1988 

1989 

1990 

Peak 96 hr 21 Day 60 Day 90 Day Yearly 

0.4645 0.3376 0.2326 0.1039 0.06955 0.01715 

0.3817 0.2975 0.1925 0.125 0.08378 0.02066 

0.3879 0.2878 0.1777 0.08125 0.05425 0.01338 

0.6191 0.4632 0.25-6 0.1107 0.07402 0.0182 

5.283 4.087 1.869 0.7435 0.4963 0.1224 

1.366 1.083 0.5661 0.2211 0.1475 0.03642 

1.073 0.7974 0.3695 0.1795 0.1199 0.02957 

2.021 1.505 0.9975 0.4399 0.2936 0.07221 

0.745 0.6125 0.4104 0.1819 0.1214 0.02996 

9.79 7.413 3.038 1.145 0.7645 0.1885 

0.3855 0.2835 0.1685 0.08227 0.05552 0.01372 

8.623 6.668 2.947 1.117 0.7458 0.1834 

0.411 0.3067 0.2061 0.09342 0 -0626 0.01544 

2.378 1.765 0.8868 0.3386 0.2259 0.05582 

1.141 0.8859 0.4477 0.2369 0.1583 0.03904 

1.537 1.181 0.6751 0.2956 0.1974 0.04854 

0.3957 0.3006 0.1907 0.1002 0.06686 0.01652 

3.929 2.932 1.263 0.5169 0.3449 0.08504 

5.353 4.06 1.709 1.034 0.6906 0.1703 

0.6646 0.5279 0.4062 0.1696 0.1131 0.02785 

1.259 0.9459 0.596 0.2768 0.1848 0.04557 

0.9949 0.7457 0.5013 0.2212 0.1477 0.03641 

1.94 1.488 0.8109 0.337 0.225 0.05548 

0.3895 0.291 0.1836 0.0843 0.05626 0.01384 

0.3999 0.3045 0.1849 0.08823 0.05907 0.01457 

7.899 6.042 3.196 1.283 0.8563 0.2112 

0.6804 0.5774 0.3621 0.1728 0.1154 0.02847 

0.869 0.6685 0.3491 0.1754 0.1172 0.02883 

2.106 1.782 1.187 0.4868 0.3248 0.0801 

3.851 2.855 1.208 0.4615 0.308 0.07595 

Sorted results 

Prob. Peak 96 hr 21 Day 60 Day 90 Day Yearly 

0.032258064516129 9.79 7.413 3.196 1.283 0.8563 0.2112 

0.0645161290322581 8.623 6.668 3.038 1.145 0.7645 0.1885 

0.0967741935483871 7.899 6.042 2.947 1.117 0.7458 0.1834 

0.129032258064516 5.353 4.087 1.869 1.034 0.6906 0.1703 

0.161290322580645 5.283 4.06 1.709 0.7435 0.4963 0.1224 

0.193548387096774 3.929 2.932 1.263 0.5169 0.3449 0.08504 

0.225806451612903 3.851 2.855 1.208 0.4868 0.3248 0.0801 

0.258064516129032 2.378 1.782 1.187 0.4615 0.308 0.07595 

0.290322580645161 2.106 1.765 0.9975 0.4399 0.2936 0.07221 

0.32258064516129 2.021 1.505 0.8868 0.3386 0.2259 0.05582 
0.1 7.6444 5.8465 2.8392 1.1087 0.74028 0.18209 

Average of yearly averages: 0.059818 

Inputs generated by pe4.pl - 8-August-2003 

Data used for this run: 

Output File: STAR-TXs 

Metfile: w13958.dvf 

PRZM scenario: TXsorghumOP.txt 

EXAMS environment file: pond298.e~~ 

Chemical Name : fluroxypyr 

Description Variable Name Value Units Cononents 

Molecular weight mwt 255.03 g/mol 

Henry's Law Const. henry 0.0005 atm-mA3/mol 

Vapor Pressure vapr 9.43-7 torr 

Solubility sol 7950 mg/L 

Kd Kd mg/L 
Koc Koc 68 mg/L 

Photolysis half-life kdp 0 days Half-life 

Aerobic Acpatic Metabolism kbacw 42 days Halfife 

Anaerobic Aquatic Metabolism kbacs 24 days Halfife 

Aerobic Soil Metabolism asm 14 days Halfife 

Hydrolysis: pH 5 0 days Half-life 

Hydrolysis: pH 7 0 days Half-life 

Hydrolysis: pH 9 0 days Half-life 

Method: CAM 2 integer See PRZM manual 

Incorporation Depth: DEPI cm 

Application Rate: TAPP 0.14 kg/ha 

Application Efficiency: APPEFF 0.95 fraction 

Spray Drift DRFT 0.05 fraction of application rate applied to pond 

Application Date Date 1-5 dd/rnm or dd/m or dd-m or dd-mm 

Interval 1 interval 14 days Set to 0 or delete line for single 

aPP - 

Record 17: FILTRA 

I PSCND 1 

UPTKF 

Record 18 : PLVKRT I 

PLDKRT I 

FEXTRC 0.5 

Flag for Index Res. Run IR Pond I 

Flag for runoff calc. RUNOFF none none, monthly or total(average 

of entire run)