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

PC Code: 128810

DP Barcode: 427660 December 10, 2015

MEMORANDUM

Subject: Registration Review: Draft Risk Assessment of the Environmental Fate and Ecological Risk of Azoxystrobin

To: Veronica Dutch, Chemical Review Manager Jill Bloom, Team Leader Linda Arrington, Branch Chief Risk Management and Implementation Branch 5

Pesticide Re

- Evaluation Division (7508P)

Stephen Savage, Chemical Review Manager

Rose Kyprianou, Team Leader Lance Wormell, Branch Chief Regulatory Management Branch II Antimicrobials Division (7510P)

From: Stephen Carey, Biologist William P. Eckel, Senior Science Advisor

Environmental Risk Branch 6

Environmental Fate and Effects Division (7507P)

Laura Parsons, Associate Branch Chief Risk Assessment and Science Support Branch Antimicrobial Division (7510P)

Through: Mark Corbin, Branch Chief Monica Wait, RAPL Amy Blankinship, Senior Biologist

Ibrahim Abdel

- Saheb, Environmen tal Scientist

Environmental Risk Branch 6 Environmental Fate and Effects Division (7507P)

Steven Weiss, Branch Chief Risk Assessment and Science Support Branch Antimicrobial Division (7510P)

### The Environmental Fate and Effects Division (EFED) and Antimicrobials Division (AD) have completed the draft risk assessment (DRA) for the environmental fate and ecological risk, and endangered species, for the r egistration r eview of the fungicide, azoxystrobin (PC Code 128810).

At this current stage of the r egistration r eview process, it is premature to make direct or indirect

effects determinations until further refinements are conducted. An in

- depth listed species evaluation determining the potential co

- occurrence of listed species and use patterns of

azox ystrobin is needed; however, additional information on the biology of listed species, the locations of these species, and the locations of use sites are needed to determine the extent to which screening assumptions regarding an action area apply to a parti cular listed organism.

Risk Conclusions Summary

The risks of azoxystrobin to terrestrial and aquatic animals including plants are summarized below. As a result of the DRA review for Registration Review, EFED determined that azoxystrobin exposures to aqu atic organisms and nonvascular plants continue to be potentially at risk as the new aquatic EECs (e stimated e nvironmental c oncentrations) are similar to previous calculated EECs. For azoxystrobin exposures to terrestrial animals, chronic risk concerns for birds and mammals are anticipated depending on the azoxystrobin use site; for example, there is a concern for birds only when foraging on azoxystrobin

- treated seeds ; for mammals the concern is foraging on food items with azoxystrobin residues and/or azoxys trobin

- treated seeds. Terrestrial plants, specifically dicots and those identified in incident reports as possibl y susceptible to azoxystrobin, are a concern.

For materials preservative uses, AD determined that exposure to aquatic taxa from process water created from manufacturing and leaching of azoxystrobin during in

- service use of manufactured products is expected to be low; further, these uses are not expected to result in exposure s to terrestrial taxa. In summary, risk to aquatic and terrestrial taxa exposed to process water is expected to be negligible.

The risks to each taxon exposed to foliar applications or azoxystrobin

- treated seeds are

summarized below in Tables 1 and 2 , respectively.

Table 1. Potential for Direct Effects for the Foliar Uses of Azoxystrobin 1



### .

Taxa Exposure Duration and Endpoint Maximum RQ Potential for

Direct Effects? Data gaps/

Refinements/

Lines of evidence Listed Non

listed
Aquatic vascular plants Frond Count 0.2 No No None

Aquatic non

vascular plants Measures of biomass 7.5 (listed) 3.1(non

- listed) Yes Yes None

Dicot terrestrial plants Measures of biomass 1.1 (listed) <0.1 (non

- listed) Yes No Monocots not adversely affected and only two dicot

species affected >25%; however, incident data on plants Monocot terrestrial plants Measures of biomass <0.1 No No

Freshwater fish Acute: mortality 0.32 Yes No None

### Table 1. Potential for Direct Effects for the Foliar Uses of Azoxystrobin 1



### .

Taxa Exposure Duration and Endpoint Maximum RQ Potential for

Direct Effects? Data gaps/

Refinements/

Lines of evidence Listed Non

listed

Chronic: Reduced body length 1.0 Yes

Estuarine/ marine

fish Acute: mortality 0.22 Yes No

Chronic: NOAEC extrapolated using ACR

for freshwater fish 0.72 No

Freshwater

invertebrates Acute: mortality 0.58 Yes Yes

None Chronic: Reduced

number of young/adult/day 3 .5 Yes

Estuarine/ marine

Invertebrates Acute: mortality 2.7 Yes Yes

None Chronic: Reduced young/adult/day and mortality 16 Yes

Mammals Acute oral dose: No mortality Not calculated No No

None Chronic: decreased growth in F 1 and F 2 pups 8 Yes

Birds Acute oral dose : Sub

- Acute dietary: No mortality Not calculated No No

Chronic : number of eggs laid; 3

- wk hatchlings; 14

- day

survivors 0. 2 No

Terrestrial

invertebrates Individual survival: No mortality Not c alculated No Tier 1 larval acute and

chronic larval and adult

data are not available to

evaluate risk. Individual survival: Chronic dietary No data

Brood Size and success:

Acute and chronic larval No data

ACR=Acute

- to

- chronic; RQ=risk quotient; LOC=level of concern; E/M=estuarine/marine; NOAEC=No observable adverse effect concentration; BCF=bioconcentration factor; EEC=estimated environmental concentration

1 ‘Taxa’ cells and ‘potential for direct effects’ cells are shaded as follows:

- red indicates high confidence in a high likelihood of direct adverse effects ( e.g ., multiple lines of evidence, RQs exceed LOCs, RQs b ased on reliable data and exposure estimate);

- yellow indicates lower confidence in a high likelihood of direct adverse effects ( e.g ., low confidence in data used to calculate RQs, lack of data, or few lines of evidence support the conclusion); and

- green in dicates a high confidence in a low likelihood of direct adverse effects ( e.g ., full data set, high confidence in exposure estimates and toxicity dataset).

- When data were not available to evaluate risk and there are no lines of evidence suggesting a potent ial for direct effects, the cell was not shaded.

### Table 2. Potential for Direct Effects for the Seed Treatment Use s of Azoxystrobin 1



### .

Taxa Exposure Duration and Endpoint Maximum RQ Potential for

Direct Effects? Data gaps/

Refinements/

Lines of evidence Listed Non

listed

Aquatic vascular plants Frond Count <0.1 No No None

Aquatic non

vascular plants Measures of biomass <0.1 No No None

Dicot terrestrial plants Measures of biomass <0.1 No No

None Monocot terrestrial plants Measures of biomass <0.1 No No

Freshwater fish Acute: mortality 0.0 1 No No

None Chronic: Reduced body length <0.1 No

Estuarine/ marine

fish Acute: mortality <0.01 No No

Chronic: NOAEC extrapolated using ACR

for freshwater fish <0.1 No

Freshwater

invertebrates Acute: mortality 0.02 No No

None Chronic: Reduced

number of young/adult/day 0.14 No

Estuarine/ marine

Invertebrates Acute: mortality 0. 1 Yes No

Chronic: Reduced

number of young/adult/day and mortality 0.6 No

Mammals Acute oral dose: No mortality Not calculated No No

Chronic: decreased growth in F 1 and F 2 pups 15 Yes

Birds Acute oral dose : Sub

- Acute dietary: No mortality Not calculated No No

Chronic : number of eggs laid; 3

- wk hatchlings; 14

- day

survivors 2 Yes

Terrestrial

invertebrates Individual survival: No mortality Not c alculated No Tier 1 larval acute and

chronic larval and adult

data are not available to

evaluate risk. Individual survival: Chronic dietary No data

Brood Size and success:

Acute and chronic larval No data

### Table 2. Potential for Direct Effects for the Seed Treatment Use s of Azoxystrobin 1



### .

Taxa Exposure Duration and Endpoint Maximum RQ Potential for

Direct Effects? Data gaps/

Refinements/

Lines of evidence Listed Non

listed

ACR=Acute

- to

- chronic; RQ=risk quotient; LOC=level of concern; E/M=estuarine/marine; NOAEC=No observable adverse effect concentration; BCF=bioconcentration factor; EEC=estimated environmental concentration

1 ‘Taxa’ cells and ‘potential for direct effects’ c ells are shaded as follows:

- red indicates high confidence in a high likelihood of direct adverse effects ( e.g ., multiple lines of evidence, RQs exceed LOCs, RQs based on reliable data and exposure estimate);

- yellow indicates lower confidence in a high likelihood of direct adverse effects ( e.g ., low confidence in data used to calculate RQs, lack of data, or few lines of evidence support the conclusion); and

- green indicates a high confidence in a low likelihood of dir ect adverse effects ( e.g ., full data set, high confidence in exposure estimates and toxicity dataset).

- When data were not available to evaluate risk and there are no lines of evidence suggesting a potential for direct effects, the cell was not shaded.



### Data Gaps

The e cological effects and environmental fate data base is largely completed for azoxystrobin except for the following required studies under 40 CFR Part 158:

Environmental Fate:

• None.

Ecological Effects :

• Pollinators may be exposed to azoxys trobin when foraging from off

- site plants that are contaminated by spray drift

. A complete set of toxicity data to honey bee adults and larvae

have not been submitted for azoxystrobin and are now needed under EPA’s recent policy on pollinator protection 1



### . Thus, the following six Tier I , II and III honey bee studies , yet to be submitted for azoxystrobin, are needed :

o Honey bee larval acute oral toxicity study (following OECD 2 37 )

o Honey bee adult 10

- day chronic oral (special study)

o Honey bee larval repeated dose study (special study renamed as honey bee larval chronic oral toxicity study)

o F ield testing for pollinators (OCSPP 850.3040, Tier III)

o F ield trial of residues in pollen and nectar (special study, Tier II)

o S emi

- field testing for pollinators (special study, Tier II)

.
Note that it is possible to conduct the larval chronic oral study in such a way as to derive both

an LD 50 

### (acute endpoint of interest) and a NOAEC (chronic endpoint of interest) from a single study. If the chronic larval toxicit y study is conducted in such a way that it derives

1 (Guidance for Assessing Pesticide Risks to Bees, 06.23.2014; signed by Donald Brady , Director, EFED; http://www2.epa. gov/sites/production/files/2014

- 06/documents/pollinator_risk_assessment_guidance_06_19_14.pdf )

### both an LD 50 

### and NOAEC, then a separate acute larval toxicity study is not needed. For pollinator studies without finalized OECD guidelines, protocols should be submitted for EPA review and comment prior to study initiation.

Tier II and III studies are r eserved pending the results of T ier I tests.

### 1 

# Pr eliminary Environmental Fate and Ecological Risk

Assessment in Support of the Registration Review of Azoxystrobin

Methyl(E)

- 2

- {2

- [6

- (2

- cyanophenoxy)pyrimidin

- 4

- yloxy]phenyl}

- 3

- methoxyacrylate CAS Registry Number: 13160

- 33

- 8

PC Code: 128810

Prepared by: Stephen Carey, Biologist William P. Eckel, Senior Science Advisor U. S. Environmental Protection Agency Office of Pesticide Programs Environmental Fate and Effects Division

Environmental Risk Branch VI 1200 Pennsylvania Ave., NW

Mail Code 7507P Washington, DC 20460 

### Reviewed by: Amy Blankinship, Senior Biologist

Ibrahim Abdel

- Saheb, Environmental Scientist Monica Wait, RAPL Mark Corbin, ERB6 Chief

December 10 , 2015 

## Office of Chemical Safety

and Pollution Prevention

### 2 EXECUTIVE SUMMARY

................................ ................................ ................................ ........... 3 POTENTIAL RISKS TO NONTARGET TERRESTRIAL AND AQUATIC ANIMALS AND

PLANTS 3

CONCLUSIONS

– EXPOSURE CHARACTERIZATION 6

CONCLUSIONS

– EFFECTS CHARACTERIZATION 6

II. PROBL EM FORMULATION

................................ ................................ ............................... 8

II.1. Nature of Regulatory Action 8

II.2. Mode of Action 8

III. ANALYSIS

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

III.1 Use Characterization 9

III.2. Exposure Characterization 11

III.2.1. Environmental Fate and Transport Characterization

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

III.1.3. Measures of Terrestrial E xposure

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

III.1.3.1. Exposure Modeling for Terrestrial Vertebrates

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

III.2.3.3. Exposure Modeling for Terrestrial Invertebrates

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



### III.3. Ecological Effects Characterization 30

III.3.1. Aquatic Effects Characterization

................................ ................................ ......................... 31

III.3.2. Terrestrial Effects Characterization

................................ ................................ ..................... 37



### IV. RISK CHARACTERIZATION

................................ ................................ ........................... 47

IV.1. Risk Estimation

- Integration of Expo sure and Effects Data 47

IV.1.1

. Non

- target Aquatic Organisms

................................ ................................ ........................... 49

IV.1.2 Terrestrial Animals

................................ ................................ ................................ ............... 64

IV.1.3. Terrestrial Plants in Dry and Semi

- aquatic Environments

................................ ................... 71



### IV.2. Risk Description 72

IV.2.1. Risks to Aquatic Organisms and Plants

................................ ................................ ............... 73

IV.2.2. Risks to Terrestrial Animals and Plants

................................ ................................ ............... 79



### V. FEDERALLY THREATENED AND ENDANGERED (LISTED) SPECIES CONCERNS

.................... 84

V.1. Endocrine Disruptor Screening Program 85

### 3 

# EXECUTIVE SUMMARY

Azoxystrobin is registered as a systemic fungicide for agricultural, commercial, outdoor, residential, indoor , and antimicrobial uses with aerial and ground applications , chemigation, and

seed treatments

. Foliar application rates range from 0.1 to 0.55 pounds of active ingredient per acre (lb a.i./A) per application with seasonal maximum application rates ranging from 0.45 to 5.0

lb a.i ./A. Maximum seed treatment rates range from 0.00062 lb a.i./A to 0.012 lb a.i./A. As a materials preservative, liquid formulations of azoxystrobin are added during manufacturing to paper, building materials, fibers, rubber and plastics.



## POTENTIAL RISKS T O NONTARGET TERRESTRIAL AND AQUATIC ANIMALS AND

PLANTS

Taxa for which risk were identified at or above the Agency’s levels of concern for foliar applications and seed treatments are summarized below in Table s 1 and 2

.

For antimicrobial uses, exposure to aquatic taxa from process water created from manufacturing and leaching of azoxystrobin during in

- service use of manufactured products is expected to be

l ow; further, these uses are not expected to result in exposure to terrestrial taxa. In summary, risk

to these tax a exposed to process water is expected to be negligible.

Table 1 . Potential for Direct Effects on the Foliar Use of Azoxystrobin 1



### .

Taxa Exposure Duration and Endpoint Maximum RQ Potential for

Direct Effects? Data gaps/

Refinements/

Lines of evidence Listed Non

listed
Aquatic vascular plants Frond Count 0.2 No No None

Aquatic non

vascular plants Measures of biomass 7.5 (listed) 3.1(non

- listed) Yes Yes None

Dicot terrestrial plants Measures of biomass 1.1 (listed) <0.1 (non

- listed) Yes No Monocots not adversely affected and only two dicot

species affected >25%; however,

i ncident data on plants Monocot terrestrial plants Measures of biomass <0.1 No No

Freshwater fish Acute: mortality 0.32 Yes No

None Chronic: Reduced body length 1.0 Yes

Estuarine/ marine

fish Acute: mortality 0.22 Yes + No

Chronic: NOAEC extrapolated using ACR

for freshwater fish 0.72 No

Freshwater

invertebrates Acute: mortality 0.58 Yes Yes

None Chronic: Reduced

number of young/adult/day 3 .5 Yes

Acute: mortality 2.7 Yes Yes None

### 4 Table 1 . Potential for Direct Effects on the Foliar Use of Azoxystrobin 1



### .

Taxa Exposure Duration and Endpoint Maximum RQ Potential for

Direct Effects? Data gaps/

Refinements/

Lines of evidence Listed Non

listed

Estuarine/ marine

Invertebrates Chronic: Reduced young/adult/day and mortality 16 Yes

Mammals Acute oral dose: No mortality Not calculated No No

None Chronic: decrea s ed growth in F 1 and F 2 pups 8 Yes

Birds Acute oral dose : Sub

- Acute dietary: No mortality Not calculated No No

Chronic : number of eggs laid; 3

- wk hatchlings; 14

- day

survivors 0. 2 No

Terrestrial

invertebrates Individual survival: No mortality Not c alculated No Tier 1 larval acute and

chronic larval and adult

data are n ot available to

evaluate risk. Individual survival:

C hronic dietary No data

Brood Size and success:

Acute and chronic larval No data

ACR=Acute

- to

- chronic; RQ=risk quotient; LOC=level of concern; E/M=estuarine/marine; NOAEC=No observable adverse effect concentration; BCF=bioconcentration factor; EEC=estimated environmental concentration

1 ‘Taxa’ cells and ‘potential for direct effects’ cells are shaded as follows:

- red indicat es high confidence in a high likelihood of direct adverse effects ( e.g ., multiple lines of evidence, RQs exceed LOCs, RQs based on reliable data and exposure estimate);

- yellow indicates lower confidence in a high likelihood of direct adverse effects ( e.g ., low confidence in data used to calculate RQs, lack of data, or few lines of evidence support the conclusion); and

- green indicates a high confidence in a low likelihood of direct adverse effects ( e.g ., full data set, high confidence in exposure estimates a nd toxicity dataset).

- When data were not available to evaluate risk and there are no lines of evidence suggesting a potential for direct effects, the cell was not shaded.



### Table 2. Potential for Direct Effects on the Seed Use of Azoxystrobin 1



### .

Taxa Exposure Duration and Endpoint Maximum RQ Potential for

Direct Effects? Data gaps/

Refinements/

Lines of evidence Listed Non

listed

Aquatic vascular plants Frond Count <0.1 No No None

Aquatic non

vascular plants Measures of biomass <0.1 No No None

Dicot terrestrial plants Measures of biomass <0.1 No No

None Monocot terrestrial plants Measures of biomass <0.1 No No

Freshwater fish Acute: mortality 0.0 1 No No None

### 5 Table 2. Potential for Direct Effects on the Seed Use of Azoxystrobin 1



### .

Taxa Exposure Duration and Endpoint Maximum RQ Potential for

Direct Effects? Data gaps/

Refinements/

Lines of evidence Listed Non

listed

Chronic: Reduced body length <0.1 No

Estuarine/ marine

fish Acute: mortality < 0.01 No No

Chronic: NOAEC extrapolated using ACR

for freshwater fish <0.1 No

Freshwater

invertebrates Acute: mortality 0.02 No No

None Chronic: Reduced

number of young/adult/day 0.14 N o

Estuarine/ marine

Invertebrates Acute: mortality 0. 1 Yes No

Chronic: Reduced

number of young/adult/day and mortality 0.6 No

Mammals Acute oral dose: No mortality Not calculated No No

Chronic: decreased growth in F 1 and F 2 pups 15 Yes

Birds Acute oral dose : Sub

- Acute dietary: No mortality Not calculated No No

Chronic : number of eggs laid; 3

- wk hatchlings; 14

- day

survivors 2 Yes

Terrestrial

invertebrates Individual survival: No mortality Not c alculated No Tier 1 larval acute and

chronic larval and adult

data are not available to

evaluate risk. Individual survival: Chronic dietary No data

Brood Size and success:

Acute and chronic larval No data

ACR=Acute

- to

- chronic; RQ=risk quotient; LOC=level of concern; E/M=estuarine/marine; NOAEC=No observable adverse effect concentration; BCF=bioconcentration factor; EEC=estimated environmental concentration

1 ‘Taxa’ cells and ‘potential for direct effects’ cells are shaded as follows:

- red indicates high confi dence in a high likelihood of direct adverse effects ( e.g ., multiple lines of evidence, RQs exceed LOCs, RQs based on reliable data and exposure estimate);

- yellow indicates lower confidence in a high likelihood of direct adverse effects ( e.g ., low confiden ce in data used to calculate RQs, lack of data, or few lines of evidence support the conclusion); and

- green indicates a high confidence in a low likelihood of direct adverse effects ( e.g ., full data set, high confidence in exposure estimates and toxicity dataset).

- When data were not available to evaluate risk and there are no lines of evidence suggesting a potential for direct effects, the cell was not shaded

.

### 6 

## C ONCLUSIONS

– EXPOSURE CHARACTERIZATION

Azoxystrobin is relatively persistent, but not highly mobile. T he dissipation of azoxystrobin is predomina n tly dependent on aquatic photodegradation and to a lesser extent microbial

- me diated degradation, and limited mobility in to ground a nd surface waters

. The low mobility in soil was confirmed in the field studies where azoxystrobin dissipated slowly on the surface (0

- 6 inch) of

non

- flooded soils. No azoxystrobin residue was found in soil layers deeper than 6 inches (TFD studies, Table I II.1)

. Since photodegradation is a major route of degradation for azoxystrobin, the dissipation of azoxystrobin is expected to be dependent on condition of the water ( e.g ., sediment loading, depth, etc .) affecting sunlight penetration

. Although azoxystrobin has limited mobility and is subject to photolysis, the compound has been detected in federal and state surface water monitoring studies.



## CONCLUSIONS

– EFFECTS CHARACTERIZATION

Available toxicity data classifies azoxystrobin as h ighly toxic to freshwater and estuarine/marine fish and freshwater invertebrates, but is very highly toxic to estuarine/marine invertebrates on an acute exposure basis

. F reshwater fish serve as surrogates for aquatic

- phase amphibians in the absence of amph ibian

- specific data; therefore, azoxystrobin is classified as highly toxic to aquatic

- phase amphibians. Chronic exposure resulted in impaired growth in freshwater fish and invertebrates and reproductive effects in estuarine/marine invertebrates

. In the abs ence of data,

an a cute

- to

- c hronic r atio (ACR) w as used to estimate the chronic toxicity endpoint for estuarine/

marine fish. Toxicity data show that of the degradates of azoxystrobin , three degradates (compounds 2, 28 and 30) are practically nontoxic to fr eshwater fish and invertebrates and to aquatic nonvascular plants ; the other degradates’ (i.e. compounds 9 (Z

- isomer)) toxicity to aquatic organisms is unknown as data are not available. T hus, the only stressor of concern for ecological effects is azoxyst robin , the parent compound . Studies conducted with a typical end

use product (TEP) co

- formulated with the fungicide chlorothalonil, indicate that that product is very highly toxic to freshwater fish and that aquatic non

- vascular plants are more sensitive to the TEP than to technical grade azoxystrobin because chlorothalonil contributes to the toxicity of the formulated product

.

For terrestrial wildlife, a zoxys trobin is practically nontoxic to birds on both an acute oral and subacute dietary exposure basis. Since birds serve as surrogates for reptiles and terrestrial

- phase amphibians in the absence of taxa

- specific data

, azoxystrobin is classified as practicall y nontoxic to reptiles and terrestrial

- phase amphibians on an acute exposure basis

. Chronic exposure resulted in reproductive effects in birds

.

Azoxystrobin is practically nontoxic to mammals on an acute oral basis . Chronic exposure resulted in impaired growth of offspring

.

Azoxystrobin is classified as practically non

- toxic to adult honey bee s ( Apis mellifera ) on an

acute contact and oral exposure basis. A formulated product was also tested and is practically

non

- toxic to adult honey bees as well

.

### 7 Effects to terrestrial plants were limited to the seedling emergence in which dicotyledonous plants were the only species to be inhibited 25% or more. None of the monocot yledonous plants

tested were impacted.

### 8 

# II. PROBLEM F ORMULATION

In 2009, the Environmental Fate and Effects Division of the Office of Pesticide Programs completed a preliminary problem formulation 1 

### for the ecological risk and drinking water assessments for azoxystrobin

, which was then released for comment. The preliminary problem formulation provides a more detailed discussion of ecosystems potentially at risk, assessment endpoints evaluated in the risk assessment

, conceptual model

, and risk hypothesis associated with the uses of azoxystrobin. An analysis plan was also articulated

, an d the reader is referred to

that document.



## II.1. Nature of Regulatory Action

Under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), all pesticides distributed or sold in the United States must be registered by the United States Environmental Protection Agency (EPA or the Agency). To determine whether a pesticide can be registered, the EPA evaluates the product’s safety to non

- target species based on a wide range of environmental and

health effects studies. In 1996, FIFRA was amended by the Food Quality Protection Act (FQPA), and EPA was mandated to implement a new program for the periodic review of pesticides, i.e ., Registration Review 2 

### . The registration review program is intended to ensure that

as the abil ity to assess risk evolves and as policies and practices change, all registered pesticides continue to meet the statutory standard of no unreasonable adverse effects to human health and the environment. Changes in science, public policy, and pesticide use practices will occur over time. Through the registration review program, the Agency periodically reevaluates pesticides to make sure that as changes occur, products in the marketplace can be used safely.

Additionally, potential effects to Federally

- liste d endangered and threatened species (hereafter referred to as “listed”) and their designated critical habitat are also considered under the Endangered Species Act (ESA) in order to ensure that the continued registration of azoxystrobin is not likely to jeo pardize the continued existence of listed species or adversely modify their critical habitat. In order to meet the requirements of FIFRA and the ESA, this assessment follows EPA guidance on conducting ecological risk assessments (USEPA, 1998) and Office o f Pesticide Program’s Overview Document, which contains guidance for assessing pesticide risks

to non

- listed and listed species (USEPA, 2004).



## II.2. Mode of Action

Azoxystrobin is a fung icide in a class of compounds called β

- methoxy acrylates, which are derived from the naturally occurring strobilurins. Their biochemical mode of action is inhibition of electron transport.

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

- HQ

- OPP

- 2009

- 0835

- 0008

2 http://www2.epa.gov/pesticide

- reevaluation

### 9 

# III. ANALYSIS

In order to address the risk hypothesis in the Problem Formulation (EPA

- HQ

- OPP

- 2009

- 0835

- 0008), the potential for adverse effects on the environment is estimated. The use pattern, environmental fate, and ecological effects of azoxystrobin are charac terized and integrated to assess the risks. This is accomplished using a risk quotient (ratio of exposu re concentration to effects concentration) approach. Although risk is often defined as the likelihood and magnitude of adverse ecological effects, the risk quotient

- based approach does not provide a quantitative estimate of likelihood and/or magnitude of a n adverse effect. However, as outlined in the Overview Document (USEPA 2004), the likelihood of effects to individual organisms from particular uses of azoxystrobin is estimated using the level of concern (discussed below), lines of evidence, or actual cal culated risk quotient value.



## II I

. 1 Use Characterization

Initially registered in 1997, azoxystrobin is used as a fungicide on a wide variety of terrestrial food and feed crops and terrestrial non

- food crops

. As an antimicrobial pesticide, i t is also used

as a fungicidal materials preservative for a variety of building materials, textiles and plastics

. There are currently 95 active Section 3 product registrations for azoxystrobin ( Table s I I I.1 and

I I I.2 ). Other non

- agricultural uses include turf, ornamental s, and both indoor and outdoor

residential uses. Based on the most recent usage data provided by the Biological and Economic Analysis Division (BEAD) in the October 9, 2014 Screening Level Usage Analysis (SLUA), on

average, roug hly 1.1 million pounds of a zoxystrobin are applied annually to agricultural crops

. This represents a 42.8% increase in usage relative to what was reported in the April 9, 2009 SLUA (778,000 lbs).

Azoxystrobin is formulated as a water dispersible granule, dry flowable, emulsifiable concentrate, flowable concentrate, granular, dust, and liquid. Azoxystrobin applications are made

pre

- plant, at

- plant, pre

- transplant, at

- emergence, spring, early summer, summer, crown, foliar,

post

- plant, at bud break

- through, early jointing, early bloom, bloom, petal fall, tillering, boot, cutting, pre

- harvest, post

- harvest, delayed dormant through foliar, and seed treatment.

Application methods include aerial and ground spray, chemigation (drip irrigation, sprinkler irrigation), pump sprayer, soil in

- furrow treatment, band, basal spray treatment, dip treatment, drench, injection treatment, high volume spray (low concentration), low volume spray (high concentration), high and low volume ground sprayer, and seed treatment (slurry and mis t

- type seed treater). Indoor uses are surface treatment s with hand held spray wand, pump

- up sprayer, package applicator

, and pressure sprayer

.

Azoxystrobin end

- use products can be co

- formulated with other pesticide active ingredients such

as chlorothaloni l, difenoconazole, cyproconazole, fludioxonil, propiconazole, thiamethoxam,

lambda

- cyhalothrin, mefenoxam, tetraconazole, acibenzolar

- S

- methyl, and abamectin

.

### 10 Table I I I .1. Overview of Fungicid al Uses of Azoxystrobin Crop Grouping Representative Use

Agricultural uses Almonds, artichoke (globe), asparagus, bananas (& plantains), barley, oats, rye,

bus hberries, caneberries, cranberries, low growing berries, dry beans, dry and succulent beans, brassica head and stem, brassica (cole) leafy vegetables, brassica leafy greens, bulb vegetables, canola, carrots, cel ery, chickpeas, citrus fruits, corn (field, pop and seed), corn (sweet) , cotton, cucurbits, filberts, fruiting vegetables, grapes and other vine climbing small fru its, herbs & spices, leafy vegetables, legume vegetables, dry and succulent and legume vegetables, foliage of any cultivar of bean and field pea, mint, nongrass animal feeds (forage, fodder, straw and hay), oilseed crops, onion (green and bunching), onion (dry bulb), peanuts, pecans, pepper/eggplant/okra, pistachios, potatoes, rice, sorghum, soybean & immature soybean seeds (edamame), stone fruits, strawberries, sugarbeet, sugarcane, Ti palm, tobacco, tomatoes & tomatillos, tree nuts, tropical fruits, root and tuber vegetables, tuberous and corm vegetables, watercress, cereals, and wild rice.

Outdoor Uses Golf course turf, ornamentals, recreational areas/lawns, Christmas tree plantations, grasses grown for seed, ornamental sod f arms, seed orchard trees, and trees such as softwood/conifers, cypress, fir, juniper, red cedar, and spruce.

Residential Uses (Indoor/Outdoor) Domestic dwellings/premi ses, carpets, residential lawns and ornamentals.

Antimicrobial U ses Materials preservative added during manufacturing to: Paper, building materials, fibers, rubber and plastics. wallboard (drywall and gypsum board) and paperboard products, ceiling tiles, water

- based paints, stains, and coatings, latex caulks, sealants, adhesives, and binders, natural and synthetic fibers (textiles, fabrics, canvas and cordage which are not for apparel, but may include building materials such as awnings, boat covers, carpets (carpet backing only), cordage, tents, tarpaulins and wall

- covering yarn), rubber and plastic products.

Commercial (Indoor/Outdoor) Institutional/industrial premises/equipment, hospitals, storage/warehouses, transportation facilities, automobiles, industrial lawns.



### Table I I I. 2. Registered Uses and Application Rates for Azoxystrobin

Use Range of Max. Single Application Rate s (lbs a.i./A) 1 Maximum Seasonal Application Rate

(lbs a.i./A)

Grapes, pecans, peaches, bananas, wheat, bulb vegetables, cotton, tropical fruits Up to 0.25 up to 1.5

Citrus fruits, Root & Tuber Vegetables, Strawberry, mint, watercress, Grasses grown for seed, Leafy Brassica and Turnip greens, Bushberries, Peppers, Okra, Eggplant, Artichoke, Head and Stem Brassica, Asparagus, Herbs Max rates range from 0.2

to 0.33 0.8 to 2

Wild Rice 0.1

– 0.3 0.7

Leafy Vegetables & Cilantro, Corn, Peanuts, Soybeans, Tomatoes 0.1

– 0.4 0.4 to 2

Turf 0.55 5

Barley 0.1

– 0.2 0.4

Herbs 0.25 1.5

### 11 Table I I I. 2. Registered Uses and Application Rates for Azoxystrobin

Use Range of Max. Single Application Rate s (lbs a.i./A) 1 Maximum Seasonal Application Rate

(lbs a.i./A)

Spices 0.25 1.5

Seed Production 0.11 to 0.23 0.45

Tobacco 0.2 0.52

Fruiting vegetables 0.1 to 0.25 1.0

Forage, fodder, straw, and hay grass and non

- grass, legume vegetables 0.1 to 0.25 0.75 to 1.5

Clover, Cotton

– Aerial Spray 0.15 0.45

Sorghum, Sugarcane

– Ground/Aerial Spray 0.2 0.8

Seed Treatment

– Head/Stem Brassi ca Crops 0.00198

(3.08 fl oz/cwt) 0.00198

Seed Treatment

– Sorghum 0.00048

(3.75 fl oz/cwt) 0.00048

1 lbs a.i./A = pounds of active ingredient per acre



## III. 2

. Exposure Characterization

III. 2 .1. Environmental Fate and Transport Characterization

Azoxystrobin is relatively persistent and mobile to moderately mobile. The primary route of degradation for azoxystrobin is through photolysis in water and on soil and to a lesser extent by

microbial

- mediated degradation in soil. The compound is stable to hydrolysis. Since photodegradation is a major route of degradation for azoxystrobin, the dissipation of azoxystrobin is expected to be dependent on condition s of the water affecting sunlight penetration ( e.g ., sediment loading, depth, etc. )

. Table III

. 3 li sts the environmental fate properties of azoxystrobin

as identified in the submitted environmental fate and transport studies

.



### Table III. 3

. Environmental fate properties of azoxystrobin, the degradation/transformation products and the residues of concern.

Study

(Guideline Numbers) Value Degradation/Transformat

ion Products 1



### (maximum % of applied radioactivity) MRID#

Henry’s Constant (at 20 oC) 7.3 x 10

- 14 atm m 3 mol

- 1 NA

Vapor Pressure 8.2 x 10

- 13 torr (mm Hg) NA

(161

- 1, 835.2120)

Hydrolysis T 1⁄2 (at 25 ° C) stable at pH5, 7, 9 NA 43678172

(161

- 2, 835.2240)

Direct Aquatic Photolysis T 1⁄2 = 11 and 17 days Compound 9 (15.0%)

Compound 13 (1.7%) 43678173

44150904

### 12 Table III. 3

. Environmental fate properties of azoxystrobin, the degradation/transformation products and the residues of concern.

Study

(Guideline Numbers) Value Degradation/Transformat

ion Products 1



### (maximum % of applied radioactivity) MRID#

T 1⁄2 Compound 21 (<5.6%)

Compound 24 (<2.6%)

Compound 28 (<8.9%)

Compound 30 (<2.4%)

CO 2 (5.9%)

(161

- 3, 835.2410)

Soil Photolysis T 1⁄2 = 17.6 to 28.4 days Compound 3 (0.7%)

Compound 9 (9.0%)

Compound 13 (<3.5)

Compound 19 (<6.0%)

Compound 24 (<3.2%)

Compound 28 (<6.5%)

Compound 30 (<5.0%)

U13 (<5.2%)

CO 2 (<17 to 24%) 43678174

(162

- 1, 835.4100)

Aerobic Soil Metabolism

T 1⁄2 72, 85, 164 days Compound 2 (28%) **

Compound 3 (3.1%)

Compound 28 (3.1%)

Compound 30 (<2.8%)

Compound 36 (2.8%)

CO 2 (18 to 27%) 43678175

44046801

(162

- 2, 835.4200)

Anaerobic Soil Metabolism

T 1⁄2 DT 50

– 49

- 56 days Compound 2 (68%) **

Compound 3 (0.6%)

Compound 28 (4.2%)

Compound 30 (<2.8%)

Compound 36 (1.1%)

CO 2 (<5%) 43678175

44046801

(162

- 4, 835.4300)

Aerobic Aquatic

Metabolism T 1⁄2 138 (SFO)/609(IORE)

to 206 days (SFO) 49112201

(162

- 3, 835.4400)

Anaerobic Aquatic Metabolism, T 1⁄2 50 to 59 days

(soil

- water system)

62.3 90 % upper bound 43678175

### 13 Table III. 3

. Environmental fate properties of azoxystrobin, the degradation/transformation products and the residues of concern.

Study

(Guideline Numbers) Value Degradation/Transformat

ion Products 1



### (maximum % of applied radioactivity) MRID#

(164

- 1, 835.6100)

Terrestrial Field Dissipation T 1⁄2 65 days

85 days

60 days

28

- 32 days Compounds 2, 9, 28

Compounds 28, 29

Compounds 2, 9

Compounds 28, 30

Compound 2 (6.7%)

Compound 28 (3.7%)

Compound 30 (0.5%)

Compound 30

Compound 28, 30

Compounds 28, 30 43678184

43678185

43678186

43678187

44058709

44058711

44058712

44058713

(163

- 1, 835.1240) Mobility (Freundlich Sorption Coefficients) K fads 1.5 to 23 mL/g

0.35 to 6.8 mL/g

0.76 to 11 ml/g

0.27 to 4.2 ml/g Azoxystrobin

Compound 2

Compound 28

Compound 30 43678178

43678181

43678179

43678177

43678180

1 Structures and chemical names are given in Appendix 1. Table1.

* Residue of concern.

** Major degradation products (>10%). 

### SFO: single first

- order kinetics; IORE: Indeterminate order rate equation kinetics.

In terms of abiotic routes of degradati on, a zoxystrobin is stable to hydrolysis at pH 5, 7, and 9 at

25 ° 

### C ; however

, t he dissipation half

- life (T 1⁄2 

### ) of azoxystrobin by photolysis on soil is 34.4 days and in surface water is 12.5 days. T he Z

- isomer ( ( methyl (Z)

- 2

- {2

- [6

- (2

- cyano

phenoxy)pyrimidin

- 4

- yloxy]

- phenyl}

- 3

- methoxyacrylate) ; Compound 9)) of azoxystrobin , a transformation product o nly formed during photolysis, was previously determined by t he Health Effects Division (HED) to be a residue of concern for dietary exposure. For drinking water, a total toxic residue (TTR) half

- life was calculated for photolysis in surface water of 15.4 d ays based on residues of the parent compound combined with the Z

- isomer ; however, for the ecological aspect of the risk assessment, only the parent compound was used in the calculations

because the Z

- isomer does not form in soil metabolism studies

.

With respect to biotic routes of degradation, azoxystrobin is expected to slowly undergo

biotransformation in aerobic and anaerobic soils. T he aerobic soil metabolism half

- lives range

from 72 to 164 days ; therefore, a zoxystrobin is expected to be moderately per sistent to persistent

in aerobic mineral soils.

A new aerobic aquatic metabolism study (MRID 49112201) was submitted since the 2009

Problem Formulation ; t he aerobic aquatic metabolism half

- life ranged from 138 to 206 days.

### 14 Transformation Products

Nine degradation or transformation products were identified in the photolysis studies. Only the

Z

- isomer of azoxystrobin and parent azoxystrobin have been identified as residues of concern in drinking water

. Five degradation products were identified in laborato ry metabolism studies (aerobic and anaerobic). In the terrestrial field dissipation studies, five degradation/ transformation products were identified (including the Z

- isomer).

The major degradation or transformation processes which act on azoxystrobin ar e photolysis i n water and o n soil and biotransformation in soil and water. Six degradation or transformation

p roducts ( Appendix 1, Table 1 ) plus CO 2 

### were identified in the aqueous photolysis study. They are compounds 9 (percent of applied 15.0%), 13 (1.7%), 21 (<5.6%), 24 (<2.6%), 28 (<8.9%), and 30 (<2.4%). Only compound 9 ( Z isomer: methyl (Z)

- 2

- {2

- [6

- (2

- cyano

- phenoxy)pyrimidin

4

- yloxy]

- phenyl}

- 3

- methoxyacrylate) which is an isomer of azoxystrobin has been determined to be an degradation or transformation product of concern. A similar distribution of transformation products w as identified in the soil photolysis study

. ; compounds 9 (percent of appli ed 9.0%), 3 (0.7%), 13 (<3.5%), 19 (<6.0%), 24 (<3.2%), 28 (<6.5%), and 30 (<5.0%), and U13 (<5.2%).

In the aerobic soil metabolism degradation products identified were compounds 2 (percent of applied 28%), 3 (3.1%), 28 (3.1%), 30 (<2.8%), 36 (2.8%), and CO 2 

### (17

- 24%). The degradation products in the anaerobic studies identified were 2 (68%), 3 (0.6%), 28 (4.2%), 30 (2.8%), 36 (<1.1%), and CO 2 

### (<5%). Compound 9 was not identified in the aerobic and anaerobic metabolism studies (laboratory studies) , thus i t was not included as a residue of concern . F ive transformation products were identified in the terrestrial field dissipation studies

.

Mobility

Based upon organic carbon partition coefficients (K
oc 

### ) values of 210 to 1610 mL/g
oc 

### , azoxystrobin is classified as mobile to moderately mobile according to the FAO classification

scheme. The K oc values (21 to 500 mL/g
oc 

### ) for the transformation compounds 2, 28, and 30 suggest that they are more mobile than azoxystrobin. The soil/water pa rtitioning coefficients (Freundlich K f 

### ) for azoxystrobin ranged from 1.5 to 23 mL/g
oc 

### . The relatively low mobility was confirmed in the field studies where azoxystrobin dissipated slowly on the surface (0

- 6 inch) of

non

- flooded soils. No azoxystrobin re sidue was found in soil layers deeper than 6 inches. The vapor pressure of azoxystrobin ( 8.2 x 10

- 13 

### torr @ 25 o C ) would suggest that it has a low potential to volatilize from dry or moist soils or from water.

Bioaccumulation

Based on the low octanol

- water partitioning coefficient (K
ow 

### = 316) , azoxystrobin is not expected to bioaccumulate in aquatic organisms

.

### 15 Table III. 4

. Summary of environmental fate parameters for azoxystrobin and values
used for modeling (SWCC , GENEEC, and Rice ).

Parameter Value or Range Value Used in Model Source

Molecular Weight 403.4 g/mol 403.4 g/mol

Solubility in water @ 20 ° C 6.7 mg/L 6.7 mg/L

Vapor Pressure @ 25 ° C 8.2x10

- 13 torr 8.2x10

- 13 torr

Hydrolysis T 1⁄2 (at 25 ° C) 1 Stable @ pH 5, 7, & 9 0 43678172

Aquatic Photolysis T 1⁄2 12.5 days 1

- p arent only 15.4 days

Photolysis Reference Latitude:

30 ° 43678173

44150904

Aerobic Soil Metabolism

T 1⁄2 1 116 days

84.8 days

143 days 142 days 3 @ 20 ° C (SWCC) 100.5 days 2,3 @ 25 ° C (PRZM

- GW) 43678175

44046801

Anaerobic Soil Metabolism

T 1⁄2 1 46.1 days

57.3 days 62.3 days 3 43678175

44046801

Aerobic aquatic

Metabolism T 1/2 @ 20 ° C 206 days (SFO)

609 days (IORE) 787.5 days 3 49112201

Anaerobic Aquatic Metabolism, T 1⁄2 1 46.1 days

57.3 days 62.3 days 3 43678175

Sorption K d 1.5 to 23 mL/g 8.87 43678178

Foliar Dissipation Half

Life 1 22.8 days, 13.7 days

7.98 days, 5.26 days,

5.4 days, 10.5 days 14.8 days 3 44150911

Application Efficiency

-- 0.99

– ground application

0.95

– aerial application

Spray Drift % to pond

-- 0.125

– aerial

0.062

- ground (EFED, 200 9 )

1 Half

- lives were recalculated using PestDF (EFED, 2014) . IORE half

- life value of 609 days used for water column metabolism; SFO half

- life 138 days, Log

- linear half

- life 141 days.

2 EFED Input Parameter Guidance: 90 th Percentile (EFED, 2009)

3 Half

- life values adjusted to 25 ° C



### Monitoring Data

Monitoring data for azoxystrobin were downloaded from the Water Quality Portal database ( http://waterqualitydata.us /) on May 28 , 2015. The Water Quality Portal integrates data from the USGS National Water Information System (NWIS), EPA’s STORET data warehouse, and USDA ARS STEWARDS platform. A total o f 5,581 records were retrieved for the analysis of azoxystrobin spanning from 2006 to 2014. The majority of the data comes from the Minnesota Department of Agriculture with 2,662 records from the years 2010 to 2014. There were 1,661

detects with a concen tration range from 10.2 to 589 ng/L. The Water Quality portal contained data from four additional states; Arizona, Montana, Colorado, and Indiana; however, the samples

from these states were all non

- detects.

### 16 The USGS National Water Quality Assessment (NA WQA) Program also contains azoxystrobin monitoring data ( http://cida.usgs.gov/nawqa_queries_public/jsp/mxmaster.jsp ) and was also accessed on May 28, 2015. The NAWQA database has 8 4 records from 8 states from the years

2010 to 2013 ( Table III. 2 ) with detections as high as 520 ng/L in surface water

.

Table III. 2 . NAWQA Azoxystrobin Monitoring Results.

State Year Total Records Detects Concentration Range (ng/L)

GA 2010 2 0

--
CA 2012 12 7 7

– 128.3

IA 2013 12 4 3.4

– 86

IN 2013 12 7 6.4

– 86

MO 2013 11 9 7.2

– 99.2

NE 2013 12 10 4

– 520.1

TX 2013 11 0

--
WI 2013 12 6 24.2

– 69.8



### Data from California Department of Pesticide Regulation was also accesse d for this assessment

on June 10 , 2015. The sampling period s for which azoxystrobin w ere monitored in surface and ground water w ere 2004

- 2005, 2007

- 2008, and 2012. A total of 86 records were retrieved with a limit of quantitation of 0.5 ppb for years 2004

- 2008 and 0.005 μg/L (parts per billion; ppb ) in

2012. For years 2004

- 2008, there were 56 records and 5 detections (9% detection frequency) ranging from 0.53 to 2.67 ppb. In 2012, there were 30 records and 17 detections (57% detection frequency) ranging from 0.0062 to 0.012 ppb suggesting that the more sensitive detection limits provided a better opportunity to determine the extent to which azoxystrobin is moving into

surface waters

. The CADPR surface water database can be found at: http://www.cdpr.ca.gov/docs/emon/surfwtr/surfcont.htm

.

Data provided by the State of Colorado to the EPA returned 138 results for the year 2010. Two of the samples were detects of 0.0 39 and 0.0 40 ppb with a detection limit of 0.0 20 ppb

.

None of the monitoring data listed above is a result of sampling targeted to azoxystrobin use. That coupled with a less robust sampl ing frequency would suggest that the monitoring results are most likely missing the peak co ncentrations of azoxystrobin

.

M ultiple m onitoring studies of pesticide residues in honey bee colonies (Mullin, 2010; Pettis, 2013; Stoner, 2013; Rennich, 2012) have demonstrated detectable quantities of azoxystrobin in various hive matrices ( e.g ., wax, po llen). Residues in comb wax were detected at a maximum of 278 ppb in wax (limit of detection LOD = 1 ppb) and in pollen as high as 107 ppb (LOD = 1.0 ppb).

Simulation Modeling

Aquatic exposures are quantitatively estimated for all assessed uses using sc enarios that represent high exposure sites for azoxystrobin use. Each of these sites represents a 10

- hectare

field that drains into a 1

- hectare pond that is 2 meters deep and has no outlet. Exposure estimates generated using the standard pond are intended to represent a wide variety of vulnerable water

### 17 bodies that occur at the top of watersheds including prairie pot holes, playa lakes, wetlands, vernal pools, man

- made and natural ponds, and intermittent and first

- order streams. As a group,

there are factors that make these water bodies more or less vulnerable than the standard surrogate pond. Static water bodies that have larger ratios of drainage area to water body volume would be expected to have higher peak EECs than the standard pond. These water bodies will be either shallower or have large drainage areas (or b oth). Shallow water bodies tend to have limited additional storage capacity, and thus, tend to overflow and carry pesticide in the discharge whereas the standard pond has no discharge. As watershed size increases beyond 10 hectares, at some point, it becom es unlikely that the entire watershed is planted in a single crop and treated

with the same pesticide. Headwater streams can also have peak concentrations higher than the standard pond, but they tend to persist for only short periods of time and residues a re then carried

downstream.

Surface Water

Models

For surface water assessments, the Tier 2 Surface Water Concentration Calculator (SWCC)

version 1.106 (EFED, 2014)

, Tier 1 Generic Estimated Environmental C oncentrations (GENEEC) version 2.0 (EFED, 2001) , and Tier 1 Rice version 1.0 (EFED, 2007) models w ere used to estimate environmental concentrations of the active ingredient azoxystrobin in surface

waters. For further information on these models see: http://www2.epa.gov/pesticide

- science

- and

assessing

- pesticide

- risks/about

- water

- exposure

- models

- used

- pesticide

.

Scenario Selection

The EECs for a c hemical are calculated based on the use parameters that produce the highest potential exposures (e.g., highest application rate

, minimum reapplication interval

, etc.) for the registered use sites.

The scenarios used for modeling in this assessment include the use site s that previously resulted in the highest EECs ( i.e

., turf and rice ) and uses with the highest application rates according to the October 9, 2014 SLUA. These uses include corn, peanuts, wheat, potatoes, and almonds

. Additionally, suga rcane and leafy vegetable use s are modeled to represent minor crop uses with relatively high application rates. A total of 25 standard foliar spray scenarios in the SWCC and

27 seed treatment scenarios in the GENEEC model and tier I Rice model are availab le to model these use patterns.

Additionally, t he 1999 New Use assessment for leafy vegetables (DP260137) modeled the leafy vegetable group as a maximum yearly application rate of 1.5 lbs a

. i

. /A; however, the Use Summary Table submitted by the registran t in March 2015 notes that it is possible to for some

uses to have three crop cycles (planting through harvest) in a year, which would yield a maximum yearly application rate of 4.5 lbs a

. i

. /A. It is possible that three successive seasons of azoxystrobin applications could occur in one year, either through replanting of the same crop or rotation to different crops

. B oth the single and three crop cycles per year scenarios were modeled

for this assessment.

### 18 Application parameters used for modeling azoxystr obin in SWCC , GENEEC and Rice can be

found in Table III. 3 . Application of azoxystrobin was modeled using efficiency and spray drift

values from foliar application and seed treatments. Inputs used for SWCC and GENEEC modeling can be found in Table III.1

.

Table III.3. Maximum Application Parameters for Azoxystrobin Modeling

Use site

– application

method Max. Single Application

Rate

(lbs a.i./A) Minimum Reapplication

Interval


### (Max. # Applications ) First Application

Date Max. Seasonal Application

Rate

(lbs a.i./A) SWCC modeling

Scenario 1



### Modeling for Azoxystrobin Foliar Sprays (SWWC)

Turf

– Ground 0.55 14 days (9 applications) Emergence Day 0 in SWCC 5 FLturfSTD, PAturfSTD

Corn

– Air 0.25 7 days (4 applications) V4

– V8 stage Day 15 in SWCC 2 IAcornstd

, ILCornSTD, INCornStd, KSCornStd, MNCornStd, MScornSTD, NCcornESTD, NECornStd, OHCornSTD, PAcornSTD

Peanuts

– Air 0.4 10 days (2 applications) At plant Day (

- 10) in

SWCC 0.8 NCpeanutSTD

Wheat

– Air 0.2 14 days (2 applications) Prior to disease development Day 0 SWCC 0.4 NDwheatSTD

Potatoes

– Air 0.33 7 days (6 applications) Prior to disease development Day 0 SWCC 2 IDNpotato_WirrigSTD, MEpotatoSTD

Almond

– Air 0.25 7 days (6 applications) When disease

appears Day 0 SWCC 1.5 CAalmond_WirrigSTD

Sugarcane

– Air 0.2 14 days (4 applications) Prior to rust development continuing throughout season Day 30 SWCC 0.8 FLsugarcaneSTD LAsugarcaneSTD

Leafy Vegetable

– Air 0.25 14 days 2
(1 CC/year

– 6 applications 3 CC/year

– 18 applications) Prior to disease

onset (Day 0 SWCC) 1.5 4.5 per year CAlettuceSTD, FLpepperSTD, ORbeanSTD, NJmelonSTD, MIasparagusSTD,

PAtomatoSTD 

### Modeling for Azoxystrobin Seed Treatments (GENEEC)

Use site

– application

method Max. Single Application

Rate Minimum Reapplication

Interval First Application

Date Max. Seasonal Application

Rate SWCC modeling

Scenario

### 19 (lbs a.i./A) (Max. # Applications) (lbs a.i./A)

SEED TREATMENT

- DYNASTY PRODUCT (9.6% A.I.) EPA Reg No. 100

- 1159

Brassica crops 0.00062 (3.75 fl. oz./CWT) None (one application) -- 1 0.00062 A

--

Rice 0.012 (1.53

fl. oz./ CWT) None (one application) -- 0.012

--

Sorghum 0.00175 (3.08 fl. oz./CWT) None (one application) -- 0.00175

--

Soybeans 0.00478 (0.459 fl. oz./CWT) None (one application) -- 0.00478

--

Sunflower 0.009 (37.5

fl. oz./ CWT) None (one application) -- 0.009

--

SEED TREATMENT

- DYNASTY CST PRODUCT (6.64% A.I.) EPA Reg No. 100

- 1177

Cotton 0.0032 (3.95

fl. oz./ CWT) None (one application) -- 0.0032

--

SEED TREATMENT

- DYNASTY EXTREME PRODUCT (8.33% A.I.) EPA Reg No. 100

- 1284

Cotton 0.0033 (3.0

fl. oz./ CWT) None (one application) -- 0.0033

--

SEED TREATMENT

- ADAGE DELUXE PRODUCT (0.32% A.I.) EPA Reg No. 100

- 1449

Soybean 0.0015 (4.29

fl. oz./ CWT) None (one application) -- 0.0015

--

SEED TREATMENT

- ADAGE PREMIER PRODUCT (0.32% A.I.) EPA Reg No. 100

- 1450

Soybean 0.0015 (4.23

fl. oz./ CWT) None (one application) -- 0.0015

--

SEED TREATMENT

- AVICTA CORN 250 PRODUCT (10.3% A.I.) EPA Reg No. 100

- 1405

Field corn 0.023 (11.61

fl. oz./ CWT) None (one application) -- 0.023

--

Popcorn 0.038 (25.8

fl. oz./ CWT) None (one application) -- 0.038

--

Sweet corn 0.046 (20.65

fl. oz./ CWT) None (one application) -- 0.046

--

SEED TREATMENT

- AVICTA CORN 500 PRODUCT (10.2% A.I.) EPA Reg No. 100

- 1399

Field corn 0.022 (11.4

fl. oz./ CWT) None (one application) -- 0.022

--

### 20 Popcorn 0.037 (25.2

fl. oz./ CWT) None (one application) -- 0.037

--

Sweet corn 0.045 (20.2

fl. oz./ CWT) None (one application) -- 0.045

--

SEED TREATMENT

- CRUISER EXTREME PRODUCT (0.5% A.I.) EPA Reg No. 100

- 1208

Field corn 0.00024 (2.51 fl. oz./ CWT) None (one application) -- 0.00024

--

Popcorn 0.0004 (5.58

fl. oz./ CWT) None (one application) -- 0.0004

--

Sweet corn 0.0005 (4.46

fl. oz./ CWT) None (one application) -- 0.0005

--

SEED TREATMENT

- CRUISER MAXX RICE PRODUCT (1.32% A.I.) EPA Reg No. 100

- 1369

Rice 0.0078 (7.0

fl. oz./ CWT) None (one application) -- 0.0078

--

SEED TREATMENT

- FOUR WAY VAP PRODUCT (0.9% A.I.) EPA Reg No. 100

- 1384 Foliage of Legume Veg. Crop Group 7 (common beans) 0.0029 (3.0

fl. oz./ CWT) None (one application) -- 0.0029

--

Legume Veg. Crop Group 6 (succulent or dried) 0.0077 (3.0

fl. oz./ CWT) None (one application) -- 0.0077

--

Soybean 0.0029 (3.0

fl. oz./ CWT) None (one application) -- 0.0029

--

SEED TREATMENT

- MAXIM QUATTRO PRODUCT (1.33% A.I.) EPA Reg No. 100

- 1352

Field corn 0.0003 (1.18

fl. oz./ CWT) None (one application) -- 0.0003

--

Popcorn 0.0006 (3.07

fl. oz./ CWT) None (one application) -- 0.0006

--

Sweet corn 0.0006 (2.05

fl. oz./ CWT) None (one application) -- 0.0006

--

SEED TREATMENT

- QUARTET PRODUCT (5.24% A.I.) EPA Reg No. 100

- 1286

Cotton 0.0026 (4.0

fl. oz./ CWT) None (one application) -- 0.0026

--

SEED TREATMENT

- TRIO CST PRODUCT (6.64% A.I.) EPA Reg No. 100

- 1285

### 21 CC = one crop cycle; 3 CC = three crop cycles

1 Scenarios are identified by state and crop

2 GENEEC does not have exposure scenarios or application dates for modeling.

3 Annual application rates in lb a.i./A were calculated through T

- REX using its seed treatment worksheet.



### Azoxystrobin environmental fate data used for generating model parameters are listed in Table

III. 1

. Chemical property input values were chosen in accordance with current input parameter guidance (USEPA, 2009). The SWCC EECs for foliar sprays are provided in Table III. 4 ; GENEEC EECs and Rice EECs for seed treatments are provided in Table III. 5

.

Table III

. 4 . Estimated Environmental Concentrations (EEC) for Azoxystrobin in

Standard Farm Pond from Foliar Sprays using SWCC 1

- in

- 10 year Azoxystrobin Concentration (μg/L)

Scenario

- State Crop Peak 21

- Day Average 60

- Day Average

FL

- Turf 43.7 42 40.3

PA

– Turf 32.9 32 31.1

IA

– Corn 24.3 23.4 22.1

IL

– Corn 30.9 29.7 27.8

IN

– Corn 24.9 24.1 23.1

KS

– Corn 41.1 39.3 36.6

MN

– Corn 29.7 28.6 27.6

MS

– Corn 34.2 33.3 31.4

NC

– Corn 22.2 21.3 20.2

NE

– Corn 33.2 31.7 30.2

OH

– Corn 28.9 27.9 26.2

PA

– Corn 25.3 24.8 24.8

NC

– Peanut 17.4 16.6 15.7

ND

– Wheat 10 9.69 9.2

ID

– Potato 32.5 32.1 30.9

ME

– Potato 52.6 51.3 49.1

CA

– Almond 21.5 20.6 19.7

FL

– Sugarcane 29.7 28.6 27.2

LA

– Sugarcane 31.5 30.5 28.8

CA

– Lettuce (3 CC/year) 1 82.3 80.9 79.3

CA

– Lettuce (1 CC/year) 33.5 32.5 31.1

FL

– Pepper 2 (3 CC/year) 150 152 151

FL

– Pepper 2 (1 CC/year) 50.6 49.4 51.1

OR

– Bean 2 (3 CC/year) 111 111 110

NJ

– Melon 2 (3 CC/year) 96.7 95.1 93.1

MI

– Asparagus 2 (3 CC/year) 60 58.2 56.9

PA

– Tomato 2 (3 CC/year) 96.5 95.4 92.8

1 Crop cycles per year Cotton 0.0029 (3.5

fl. oz./ CWT) None (one application) -- 0.0029

--

### 22 2 Leafy vegetable surrogate scenario



### Table III.5. Estimated Environmental Concentrations (EEC) for Azoxystrobin in

Standard Farm Pond from Seed Treatment using GENEEC and tier I Rice

1

- in

- 10 year Azoxystrobin Concentration (parts

- per

- billion

, μ g/L)

Crop Peak 21

- Day Average 60

- Day Average

DYNASTY

Brassica crops 0.0078 0.0075 0.0071

Sorghum 0.022 0.021 0.020

Rice 6.1 6.1 6.1

Soybeans 0.06 0.058 0.055

Sunflowers 0.113 0.109 0.103

DYNASTY CST

Cotton 0.04 0.039 0.037

DYNASTY EXTREME

Cotton 0.04 0.039 0.037

ADAGE DELUXE

Soybeans 0.019 0.018 0.017

ADAGE PREMIER

Soybeans 0.019 0.018 0.017

AVICTA CORN 250

Field corn 0.288 0.279 0.264

Popcorn 0.476 0.462 0.436

Sweet corn 0.576 0.559 0.523

AVICTA CORN 500

Field corn 0.288 0.279 0.264

Popcorn 0.476 0.462 0.436

Sweet corn 0.576 0.559 0.523

CRUISER EXTREME

Field corn 0.003 0.0029 0.0027

Popcorn 0.005 0.0049 0.0046

Sweet corn 0.0063 0.0061 0.0057

CRUISER MAXX RICE

Rice 4.0 4.0 4.0

FOUR

- WAY VAP
Foliage of legume veg crop group

7 0.036 0.035 0.033

Legume veg crop group 6 0.096 0.094 0.088

Soybean 0.036 0.035 0.033

MAXIM QUATTRO

Field corn 0.0038 0.0036 0.0034

Popcorn 0.0075 0.0073 0.0069

Sweet corn 0.0075 0.0073 0.0069

### 23 QUARTET

Cotton 0.033 0.032 0.03

TRIO CST

Cotton 0.036 0.035 0.033



### I II

. 1 .3. Measures of Terrestrial Exposure

III. 1 .3.1. Exposure Modeling for Terrestrial Vertebrates

Exposure estimates for terrestrial animals assumed to be in the target area or in an area exposed

to azoxystrobin as a result of spray drift or foraging for seeds are derived using the terrestrial exposure ( T

- REX ) 3 

### model (version 1.5.2.). This model incorporates the Kenaga nomograph, as modified by Fletcher et al. (1994), which is based on a large set of actual field residue data. The

upper

- limit values from the nomograph represent an approximation of the highest residue value

observ ed in the data set (Hoerger and Kenaga 1972). Consideration is given to different types of feeding strategies for mammals and birds, including herbivores, insectivores and granivores. For

dose

- based exposures, three weight classes of birds (20, 100, and 1000 g) and mammals (15, 35, and 1000 g) are considered. A cceptable foliar dissipation half

- lives of 22.8, 7.98, 13.7, and 5.26 days were available to determine a reviewer

- calculated foliar dissipation half

- life of 14.9 days

, all T

- REX EECs are based on the measured half

- life value of 14.9 days

.

Ingestion of Food Items Based on Foliar Application

The azoxystrobin application rates are taken from active labels and are used to estimate terrestrial exposure for this assessment. The dietary

- based EECs on a variety of food items from the use of azoxystrobin applied at the maximum label rates for the current uses are provided in

Table III. 6 ; dose

- based EECs are provided in Table I II. 7

.

3 USEPA. 2013. Pesticides: Science and Policy. Terrestrial Models, T

- REX Version 1.5.2. http://www2.epa.gov/pesticide

- science

- and

- assessing

- pesticide

- risks/models

- pesticide

- risk

- assessment#terrestrial

### 24 Table III. 6 . T

- REX Calculated Dietary

- Based EECs for Azoxystrobin on Food

Residues. *

Use Pattern (Foliar Application) Food Type Maximum Dietary

- based EECs (mg/kg

- diet)

Turf; 0.55 lb a.i./A x 14 days interval x 9

apps Short Grass 275

Tall Grass 126

Broadleaf plants 155

Fruits/pods/seeds 17

Arthropods 108

Corn; 0.25 lb a.i./A x 7 days interval x 4

apps Short Grass 157

Tall Grass 72

Broadleaf plants 88

Fruits/pods/seeds 10

Arthropods 62

Peanuts; 0.4 lb a.i./A x 14 days intervals x 2

apps Short Grass 146

Tall Grass 67
Broadleaf plants 82
Fruits/pods/seeds 9
Arthropods 57

Wheat; 0.2 lb a.i./A x 10 days intervals x 2

apps Short Grass 78

Tall Grass 36
Broadleaf plants 44
Fruits/pods/seeds 5
Arthropods 31

Potatoes; 0.33 lb a.i./A x 7 days interval x 6

apps Short Grass 245

Tall Grass 112
Broadleaf plants 138
Fruits/pods/seeds 15
Arthropods 96

Almonds; 0.25 lb a.i./A x 7 days intervals x 6

apps Short Grass 185

Tall Grass 85
Broadleaf plants 104
Fruits/pods/seeds 12
Arthropods 73

Sugarcane; 0.25 lb a.i./A x 14 days interval x 4

apps Short Grass 116

Tall Grass 53
Broadleaf plants 65
Fruits/pods/seeds 7
Arthropods 45

Leafy Vegetables (1 crop cycle per year); 0.25 lb a.i./A x 14 days interval x 6 apps Short Grass 123

Tall Grass 56
Broadleaf plants 69
Fruits/pods/seeds 8
Arthropods 48

Leafy Vegetables Short Grass 125

Tall Grass 57

### 25 (3 crop cycles per year); 0.25 lb a.i./A x 14 days x 18 apps Broadleaf plants 71
Fruits/pods/seeds 8
Arthropods 49

* Based on reviewer

- calculated foliar dissipation half life of 14.9 days



### Table III.7 . T

- REX Calculated Dose

- Based EECs for Azoxystrobin on Food Residues. *

Use Pattern (Foliar applications) Food Type Dose

- based EECs for

Birds (mg/kg

- bw) Dose

- based EECs for Mammals (mg/kg

- bw)

Small (20 g) Medium (100 g) Large (1000 g) Small (15 g) Medium (35 g) Large (1000 g)

Turf;

0.55 lb a.i./A x 14 days interval x 9

apps Short grass 313 179 80 262 181 42

Tall grass 144 82 37 120 83 19

Broadleaf

plants 176 100 45 147 102 24
Fruits/pods 20 11 5 16 11 3
Arthropods 123 70 31 103 71 16

Seeds (granivore) 4 2 1 4 3 0.6

Corn;

0.25 lb a.i./A x 7 days interval x 4

apps Short grass 179 102 46 150 104 24

Tall grass 82 47 21 69 47 11

Broadleaf

plants 101 57 26 84 58 14
Fruits/pods 11 6 3 9 6 2
Arthropods 70 40 18 59 41 9

Seeds (granivore) 2 1 0.6 2 1 0.3

Peanuts;

0.4 lb a.i./A x 14 days intervals x 2

apps Short grass 166 95 42 139 96 22 Tall grass 76 43 19 64 44 10

Broadleaf

plants 94 53 24 78 54 13 Fruits/pods 10 6 3 9 6 1

Arthropods 65 37 17 54 38 9

Seeds (granivore) 2 1 0.6 2 1 0.3

Wheat;

0.2 lb a.i./A x 10 days intervals x 2

apps Short grass 89 51 23 75 51 12 Tall grass 41 23 10 34 24 5

Broadleaf

plants 50 29 13 42 29 7 Fruits/pods 6 3 1 5 3 0.8 Arthropods 35 20 9 29 20 5

Seeds (granivore) 1 0.7 0.3 1 0.7 0.2

Potatoes;

0.33 lb a.i./A x 7 days interval x 6

apps Short grass 279 159 71 233 161 37 Tall grass 128 73 33 107 74 17

Broadleaf

plants 157 89 40 131 91 21 Fruits/pods 17 10 4 15 10 2 Arthropods 109 62 28 91 63 15

Seeds (granivore) 4 2 0.99 3 2 0.5

### 26 Almonds;

0.25 lb a.i./A x 7 days intervals x 6

apps Short grass 211 120 54 177 122 28 Tall grass 97 55 25 81 56 13

Broadleaf

plants 119 68 30 99 69 16 Fruits/pods 13 8 3 11 8 2 Arthropods 83 47 21 69 48 11

Seeds (granivore) 3 2 0.75 2 2 0.39

Sugarcane;

0.25 lb a.i./A x 14 days interval x 4

apps Short grass 132 75 34 111 77 18 Tall grass 61 35 15 51 35 8

Broadleaf

plants 74 42 19 62 43 10 Fruits/pods 8 5 2 7 5 1 Arthropods 52 30 13 43 30 7

Seeds (granivore) 2 1 0.47 2 1 0.25

Leafy Vegetable (1 crop cycle per year);

0.25 lb a.i./A x 14

days x 6 apps Short grass 140 80 36 117 81 19 Tall grass 64 37 16 54 37 9

Broadleaf

plants 79 45 20 66 46 11 Fruits/pods 9 5 2 7 5 1 Arthropods 55 31 14 46 32 7

Seeds (granivore) 2 1 0.50 2 1 0.26

Leafy Vegetables (3 crop cycles per year);

0.25 lb a.i./A x 14

days x 18 apps Short grass 143 81 36 120 83 19 Tall grass 65 37 17 55 38 9

Broadleaf

plants 80 46 21 67 47 11 Fruits/pods 9 5 2 7 5 1 Arthropods 56 32 14 47 32 8

Seeds (granivore) 2 1 0.51 2 1 0.27 * Based on foliar dissipation half

- life of 14.9 days estimated by the reviewer



### Ingestion of Azoxystrobin

- treated Seeds as a Result of Seed Treatment

The azoxystrobin application rates are taken from active labels and are used in T

- REX to
estimate exposure (seed dose

- based EECs) a s well as dietary

- based exposure in terms of the amount of azoxystrobin available as treated seed on a field for birds and mammals

. The dose

based EECs on seed treatment uses applied at the maximum label rates are provided in Table

III.8 ; EECs based on azoxystrobin available in the form of treated seed on the field are provided

in Table III.9

.

Table III .8 . T

- REX Calculated Dose

- Based EECs of Azoxystrobin on Seeds

.

Use (Seed treatment) Seed Application

Rate (mg a.i./kg seed) Dose

- based EECs for

Birds (mg a.i./kg

- bw/day) Dose

- based EECs for Mammals (mg a.i./kg

- bw/day)

Small (20 g) Medium (100 g) Large (1000 g) Small (15 g) Medium (35 g) Large (1000 g)

DYNASTY (9.6% A.I.)

Rice 95.59 24.2 13.8 6.2 20.3 14 3.3

### 27 Sunflower 2342.8 593 338 151 496 343 80 Soybeans 28.68 7.3 4.1 1.9 6.1 4.2 0.97 Sorghum 192.42 48.7 27.8 12.4 40.8 28.2 6.5

Head/Stems Brassica Crops 234.28 59.3 33.8 15.1 49.6 34.3 7.95

DYNASTY CST (6.64% A.I.)

Cotton 170.7 43.2 24.6 11.0 36.2 25.0 5.8 DYNASTY EXTREME (8.33% A.I.)

Cotton 162.6 41.2 23.5 10.5 34.5 23.8 5.5

ADAGE DELUXE (0.32% A.I.) Soybean 8.9 2.3 1.3 0.6 1.9 1.3 0.3 ADAGE PREMIER (0.32% A.I.) Soybean 8.8 2.2 1.3 0.6 1.9 1.3 0.3 AVICTA CORN 250 (10.3% A.I.)

Field corn 778 197 112 50 165 114 26 Popcorn 1729 438 250 112 366 253 59

Sweet corn 1384 350 200 89 293 203 47 AVICTA CORN 500 (10.2% A.I.)

Field corn 757 192 109 49 160 111 26 Popcorn 1673 423 241 108 354 245 57

Sweet corn 1341 339 194 87 284 196 46 CRUISER EXTREME (0.5% A.I.)

Field corn 8.2 2.1 1.2 0.5 1.7 1.2 0.3 Popcorn 18.2 4.6 2.6 1.2 3.9 2.7 0.6

Sweet corn 14.5 3.7 2.1 0.9 3.1 2.1 0.5 CRUISER MAXX RICE (1.32% A.I.)

Rice 60 15 8.7 3.9 13 8.8 2.0 FOUR WAY VAP (0.9% A.I.) Foliage of legume

vegetables crop group 7 17.6 4.5 2.5 1.1 3.7 2.6 0.6

Legume vegetables crop group 6 17.6 4.5 2.5 1.1 3.7 2.6 0.6

Soybean 17.6 4.5 2.5 1.1 3.7 2.6 0.6 MAXIMUM QUATTRO (1.33% A.I.)

Field corn 10.2 2.6 1.5 0.7 2.2 1.5 0.4 Popcorn 26.6 6.7 3.8 1.7 5.6 3.9 0.9

Sweet corn 17.7 4.5 2.6 1.2 3.8 2.6 0.6 QUARTET (5.24% A.I.)

Cotton 136 34.5 19.7 8.8 28.9 20.0 4.6 TRIO CST (6.64% A.I.)

Cotton 151 38.3 21.8 9.8 32.0 22.2 5.1



### Table III.9 . T

- REX Calculated EECs of Azoxystrobin

Available on a Field

.

Use Pattern (Seed treatment) Maximum Application

Rate (lb a.i./A) EE C (mg a.i./ft 2 )

DYNASTY (9.6% A.I.)

Rice 0.012 0.129

Sunflower 0.009 0.098 Soybeans 0.0048 0.05

### 28 Sorghum 0.0 018 0.018

Head/Stems Brassica Crops 0.00 06 0 .006

DYNASTY CST (6.64% A.I.)

Cotton 0.003 0.032 DYNASTY EXTREME (8.33% A.I.)

Cotton 0.003 0.032 ADAGE DELUXE (0.32% A.I.) Soybean 0.0015 0.016 ADAGE PREMIER (0.32% A.I.) Soybean 0.0015 0.015 AVICTA CORN 250 (10.3% A.I.)

Field corn 0.023 0.24 Popcorn 0.038 0.398

Sweet corn 0.046 0.48 AVICTA CORN 500 (10.2% A.I.)

Field corn 0.022 0.23 Popcorn 0.037 0.38

Sweet corn 0.045 0.46 CRUISER EXTREME (0.5% A.I.)

Field corn 0.00024 0.003 Popcorn 0.0004 0.004

Sweet corn 0.0005 0.005 CRUISER MAXX RICE (1.32% A.I.)

Rice 0.0078 0.08 FOUR WAY VAP (0.9% A.I.) Foliage of legume vegetables crop group 7 0.0029 0.03

Legume vegetables crop group 6 0.0077 0.08

Soybean 0.0029 0.03 MAXIMUM QUATTRO (1.33% A.I.)

Field corn 0.0003 0.003 Popcorn 0.0006 0.006

Sweet corn 0.0006 0.006 QUARTET (5.24% A.I.)

Cotton 0.0026 0.027 TRIO CST (6.64% A.I.)

Cotton 0.0029 0.03



### III. 1 .3.2. Exposure Modeling for Terrestrial Plants

Azoxystrobin exposure to terrestrial and semi

- aquatic plants is estimated using the Terrestrial Plant ( TerrPLANT 4 

### ; version 1.2.2) model. The model generates EECs for plants residing near a

use area that may be exposed via a combination of surface water runoff and spray drift from foliar applications

, or via surface water runoff from seed treatments

. The EECs are generated from one application at the maximum rate for a particular use and compound

- specific solubility information. Only a single application is considered because it is assumed that for plants, toxic

4 USEPA. 2013a. Pesticides: Science and Policy. Terrestrial Models, TerrPlant Version 1.2.2. http://www2.epa.gov/pesticide

- scienc e

- and

- assessing

- pesticide

- risks/models

- pesticide

- risk

- assessment#terrestrial

### 29 effects are likely to manifest shortly after the initial exposure and that subsequent exposures do not contribute to the response. Hence, the model estimates EECs based on application rate, the solubility limit, and default assumptions of drift. The EECs for terrestrial and semi

- aquatic plants for a single application of azoxystrobin current uses are presented in Table III.10

. In addition, of the numerous azoxystrobin uses which permit aerial or ground applications, turf uses with the highest single and seasonal application rate of all uses do not allow aerial applications thus only EECs from ground applications w ere modeled for turf uses.

With the AgDRIFT model (v. 2.1.1) available for modeling exposure to plants from spray drift alone, the drift EECs in TerrPLANT are no longer used for asse ssments and are replaced with AgDRIFT to better represent the azoxystrobin that is expected to drift downwind off the treated

areas to non

- target plants inhabiting areas adjacent to the treated areas. To characterize potential

non

- target plant exposure fro m spray drift alone as a result of foliar applications , Tier 1 modules in AgDRIFT were used to estimate EECs for off

- site spray drift exposure in dry and semi

aquatic areas and water bodies ( i.e. , standard farm pond) ( Table III.11 ) for water

- disper sible granular and flowable/emulsifiable concentrate formulations. For aerial applications, the American Society of Agricultural and Biological Engineers (ASABE, formerly ASAE) Fine

- to

Medium droplet size category is used in modeling. This drop let size categor y is EFED’s default distribution when labels do not specify application parameters. For ground applications, the ASABE Very Fine

- to

- Fine droplet size category is used with a high boom height. Again, this droplet size category is EFED’s default distributi on when labels do not specify the application parameters for ground applications. For seed treatments, EECs are based on surface water runoff only since seeds are planted in the ground and no spray drift is produced; thus, spray drift from

seed treatments w as not modeled.

In previous risk assessments, the highest exposure of all scenarios modeled for the current uses did not resulted in any risks of concern for terrestrial plants exposed to azoxystrobin; thus, EECs

are estimated with TerrPLANT and AgDRIFT using only the maximum and the 2 nd 

### highest application rates instead of modeling EECs for all exposure scenarios.

Table III.10

. TerrPLANT EECs for Terrestrial Plants Located Adjacent to Azoxystrobin

Treated Sites.

Max. Single Application Rate (lb a.i ./A) Application

Method TerrPLANT EECs (lbs a.i./A) Total Loading to Dry Areas Adjacent to Treated Areas 1 Total Loading to Semi

- Aquatic Areas Adjacent to Treated

Areas 2

0.55 Aerial Unincorp. Spray No aerial applications for turf uses

0.4 0.024 0.06

0.55 Ground Unincorp. Spray 0.011 0.0605

0.4 0.008 0.044

0.012 Ground Incorp. Spray 3 0.00008 0.0008

0.009 0.0006 0.006

1 EEC = Sheet Runoff (1:1 ratio) + Drift ( 0% for seed; 1% for ground; 5% for aerial)

2 EEC = Channelized Runoff (10:1 ratio ) + Drift ( 0% for seed; 1% for ground; 5% for aerial )

3 An incorporation depth of 1.5 inches is assumed for seed treatments

.

### 30 III.2 .3.3. Exposure Modeling for Terrestrial Invertebrates

Concentrations of azoxystrobin residues i n pollen and nectar resulting from foliar applications of azoxystrobin were not calculated for honey bee ( Apis mellifera ) contact and dietary routes of

exposure

. EECs will be calculated when the complete set of data for honey bees is available.



## III .3. Ecological Effects Characterization

The effects characterization describes the types of effects (toxicity) a pesticide can have on aquatic and terrestrial organisms. This characterization is based on the registrant

- submitted toxicity data as well as published toxicity data for birds, mammals, fish, invertebrates, and plants

for azoxystrobin for this phase of Registration Review.

As described in the Agency’s Overview Document (USEPA 2004), the most sensitive endpoint for each taxon is used for risk estimation. For this assessment, evaluated taxa include freshwater

and estuarine /marine fish (also a surrogate for aquatic phase amphibians), freshwater and estuarine/marine invertebrates, aquatic plants, aquatic nonvascular plants

, birds (also a surrogate
for terrestrial

- phase amphibians and reptiles), mammals, honey bee s, and terres trial plants.

Toxicity endpoints are established based on data generated from guideline studies submitted by the registrant, and from open literature studies that meet the criteria for inclusion into the ECOTOX database maintained by EPA/Office of Resear ch and Development (ORD) (U.S. EPA, 2004). In general, effects data in the open literature that indicate effects at lower concentrations

Table III.11 . Maximum Drift Loadings at Specific Distances for Terrestrial and Semi

Aquatic Areas and Ponds Alongside Azoxystrobin Use Areas.

Broadcast Application

Rate (lb a.i./A) Application

Method Distance from Edge of

Field

(ft) AgDRIFT EEC

Dry Areas (lb a.i./A) Wetland (lb a.i./A) Pond ( μ g/L)

0.55 Ground 0 0.55 0.03 1.9

10 0.1 0.02 1.2

50 0.03 0.01 0.6

100 0.01 0.007 0.4

500 0.002 0.002 0.09

997 0.0008 0.0007 0.04

0.4 Aerial 0 0.2 0.05 2.8

10 0.1 0.04 2.4

50 0.07 0.03 1.6

100 0.04 0.02 1.1

500 0.007 0.006 0.4

997 0.005 0.005 0.3

Ground 0 0.4 0.025 1.4

10 0.1 0.015 0.8

50 0.02 0.008 0.4

100 0.01 0.005 0.3

500 0.002 0.001 0.07

997 0.006 0.0005 0.03

### 31 than the registrant

- submitted data are considered. The degree to which open literature data are quantitatively or qual itatively characterized is dependent on whether the information is relevant to the assessment endpoints (survival, reproduction, and growth). For example, endpoints such as behavior modifications are likely to be qualitatively evaluated, because quantitati ve relationships between modifications and reduction in species survival, reproduction, and/or growth are not

available. On August 31 , 201 5 , of the open literature on azoxystrobin that passed the ECOTOX

screen that show ed effects at lower concentrations than the registrant

- submitted studies could be not be used quantitatively and thus they are not used in this risk assessment.

In addition to registrant

- submitted and open literature toxicity information, reviews of other

sources of information including the Ecological Incident Information System (EIIS), are conducted to further refine the characterization of potential adverse ecological effects associated with exposure to azoxystrobin. A summary of the available aquatic a nd terrestrial ecotoxicity information for azoxystrobin are provided in Section IV.2 , respectively.

Ecological effects studies have been submitted for azoxystrobin , its degradates , and the

formulated end

- use product s Heritage ® 

### Fungicide containing 50% azo xystrobin (EPA Reg

. No.

100

- 1093) and Renown ® 

### Fungicide containing 3% azoxystrobin and 45% chlorothalonil (EPA Reg

. No. 100

- 1315). In the ecological effects characterization section, toxicity values are expressed based in terms of active ingredient (a.i. ) as opposed to formulated product

.

III .3. 1

. Aquatic Effects Characterization

The most sensitive acute and chronic effects measurement endpoints associated with azoxystrobin exposure to freshwater and estuarine/marine species are summarized in Table III. 13 ; these values are used for estimating risk to aquatic organisms

. Selected effects endpoints for the risk assessment are from acceptable and supplemental studies for azoxystrobin and are briefly described below.

Based on the available acute toxicity d ata, azoxystrobin is classified as highly toxic to most aquatic

vertebrate and invertebrate organisms ; azoxystrobin is classified as very highly toxic to
estuarine/marine invertebrates . In addition, freshwater fish are surrogates for aquatic

- phase amphibians in the absence of amphibian

- specific data; therefore, using the acute toxicity data with freshwater fish, azoxystrobin would be classified as highly toxic to aquatic

- phase amphibians. Chronic toxicity data were available for fish and invertebrat es except for estuarine/marine fish

. Chronic exposure resulted in reproductive effects in estuarine/marine invertebrates and effects on growth in freshwater fish and invertebrates . Acute

- to

- c hronic r atio (ACR) calculations w ere used

to estimate the chroni c no

- observed adverse effect concentration ( NOAEC ) for estuarine /marine

fish using acute and chronic toxicity data for freshwater fish

. However, the relative sensitivity of the fish used in estimating the ACR is uncertain

.

T oxicity data show that the azox ystrobin degradates (compounds 2, 28, 30 only) are practically

nontoxic to freshwater fish and invertebrates and to a quatic nonvascular plants. However, toxicity

tests with a typical end

- use product ( TEP ) show that it is very highly toxic to freshwater fish and aquatic nonvascular plants

, indicating that the TEP is more toxic to these aquatic organisms than

the technical grade active ingredient ( TGAI )

.

### 32 Table III.13 . Most Sensitive Acute and Chronic Toxi city Data for Aquatic Organisms Exposed to Azoxystrobin and its Degradates

.

Exposure

Scenario Species Test

Material Affected Endpoint Toxicity Measurement MRID (Classification)

Freshwater Fish

Acute Rainbow trout ( Oncorhynchus mykiss ) TGAI

Mortality 96

- hr LC 50 = 0.47 mg a.i./L (no probit slope) 43678115 (acceptable) Compound 2

d egradate 96

- hr LC 50 >150

mg compound 2 /L 44158803 (acceptable)

Renown ® 96

- hr LC 50 = 0.00206 mg

a.i./L 48860607 (acceptable)

Chronic Fathead minnow ( Pimephales promelas ) TGAI Reduction in length NOAEC = 0.147 mg

a.i./L 43678120 (acceptable)

Freshwater Invertebrates

Acute Water flea ( Daphnia magna ) TGAI

Immobility 48

- hr EC 50 = 0.26 mg a.i./L (no probit slope) 43678116 (acceptable) Compound

28 d egradate 48

- hr EC 50 >50 mg Compound 28 /L 44158801 (acceptable) Compound

30 d egradate 48

- hr EC 50 >50 mg Compound 30 /L 44158802 (acceptable) Compound 2

d egradate 48

- hr EC 50 >190 mg Compound 2 /L 44158804 (acceptable)

Chronic TGAI Growth NOAEC = 0.044 mg

a.i./L 43678121 (acceptable)

Estuarine/Marine Fish

Acute Sheepshead minnow ( Cyprinodon variegates) TGAI Mortality 96

- hr LC 50 : 0.67 mg a.i./L (no probit slope) 43678117 (acceptable)

Chronic TGAI No data

available Estimated NOAEC = 0.21 mg a.i./L ACR 1

Estuarine/Marine Invertebrates

Acute Mysid shrimp ( Mysidopsis bahia ) TGAI Mortality 96

- hr LC 50 = 0.056 mg

a.i./L 43678118 (acceptable)

Chronic TGAI Reproduction NOAEC = 0.0095 mg

a.i./L 44452302 (acceptable) Aquatic Plants

7

- day

exposure Duckweed ( Lemna gibba ) TGAI Frond count 7

- day EC 50 = 3.4 mg

a.i./L NOAEC = 0.8 mg a.i./L 43678165 (acceptable)

96

- hour

exposure Freshwater diatom ( Navicula ) TGAI Cell density 96

- hr EC 50 = 0.049 mg

a.i./L NOAEC = 0.02 mg a.i./L 43678164 (acceptable)

Freshwater green algae ( Pseudokircheriella subcapitata formerly

Selenastrum capricornutum ) Renown ® Cell density 96

- hr EC 50 = 0.0053 mg

a.i./L NOAEC = 0.0026 mg

a.i./L 4886060 6 (supplemental)

1 Estimated value based on ACR method

, using rainbow trout acute and fathead minnow chronic data; The ACR of

3.19 is applied to the s heepshead minnow acute toxicity value (LC 50 of 0.67 mg/L)

.

### 33 

## Freshwater Fish, Acute Effects

Fish toxicity studies using TGAI , the Compound 2 degradate, and the formulated product

Renown ® 

### Fungicide ( containing 3% azoxystrobin and 45% c hlorothalonil) were submitted to establish the acute toxicity of azoxyst robin to freshwater fish. Results of the acu te study with the

TGAI indicate rainbow trout ( Oncorhynchus mykiss ) are the most sensitive with an LC 50 

### value of 0.47 mg a.i./L ( Table III.1 4 ). As a result, azoxystrobin is categorized as highly toxic to fish on an acute exposure basis . The TGAI LC 50 

### i s used to e stimate potential acute risk of azoxystrobin

to fresh water fish. The Compound 2 degradate is several orders of magnitude less toxic than the azoxystrobin TGAI

. When adjusted for percent azoxystrobin in the formulation, Renown ® 

### is more acutely toxic to fish than TGAI azoxystrobin by several orders of magnitude (Renown ® 

### = 0.002 mg azoxystrobin/L; TGAI = 0.47 mg a.i./L). When the formulation toxicity value is adjusted to account for the other active ingredient, chlorothalonil, the resulting value (0.031 mg a.i./L) is similar to the acu te toxicity value for chlorothalonil TGAI (0.018 mg a.i./L (MRID 45710219)), indicating that the enhanced toxicity of Renown ® 

### compared to TGAI azoxystrobin is likely due to the presence of chlorothalonil.



## Freshwater Fish, Chronic Effects

A fish early life

- stage toxicity stud y using the TGAI was submitted to establish the chronic toxicity of azoxystrobin to freshwater fish. The preferred test species is the most sensitive fish of the freshwater fish acute toxicity tests , which is the rainbow trout. However, because a different species (fathead mi nnow ; Pimephales promelas ) was used instead of the rainbow trout in the chronic study, there is uncertainty whether fathead minnows represent the most sensitive test species . T here are no acute toxicity data available for the fathead minnow and it is unknown

whether the fish is more or less sensitive than the trout on an acute exposure basis

. Results of the chronic study with the TGAI on fathead minnow indicate an NOAEC of 0.147 mg a.i./L ( Table

III.1 5 ). Thus, the NOAEC of 0.147 mg a.i./L i s used to ev aluate potential chronic effects of azoxystrobin to freshwater fish.

Table III.14 . Freshwater Fish Acute Toxicity Profi le for Azoxystrobin , Formulation, and its Degradates.

Species % a.i. or degradate LC 50 mg a.i./ L (95% Confidence Interval) Toxicity Category MRID No.

Author/Year Study

Classification

Rainbow trout ( Oncorhynchus mykiss ) 96.2 0.4 7 (0.4

- 0.58 mg a.i./L) Highly

toxic 43678115 Craig et al . 1992 Acceptable

DEG ( Compound 2 )

98 >150 mg/L Practically

nontoxic 44158803

Kent et al . 1993 Acceptable

( Renown ® )

2.94 0.0020 6 (0.00169

- 0.0025 mg a.i./L) Very highly

toxic 48860607

Bormann 2010 Acceptable

Bluegill sunfish ( Lepomis

macrochirus ) 96.2 1.1 

### ( 0.9

- 1.7 mg a.i./L ) Moderately

toxic 43678114 Sankey et al . 1992 Acceptable

### 34 Table III.15

. Freshwater Fish Chronic Toxicity Profile for Azoxystrobin.

Species % a.i. / NOAEC /

LOAEC (mg a.i./L) Endpoint

Affected MRID No.

Author/Year Study

Classification

Fathead minnow

(Pimephales promelas) 96.2 0.147 /0.193 Length 43678120

Rhodes et al . 1994 Acceptable



## Freshwater Invertebrates, Acute Effects

Toxicity studies using the TGAI, Compound 2 degradate, Compound 28 degradate, and Compound 30 degradate were submitted to establish the acute toxicity of azoxystrobin and its degradates to the waterflea ( Daphnia magna ) . Results of the acute study with the TGAI indicate

an EC 50 

### value of 0.259 mg a.i./L ( Table III.1 6 ), which categorizes azoxystrobin as highly toxic

to freshwater invertebrates on an acute exposure basis . Thus, the TGAI EC 50 

### of 0.259 mg a.i./L

i s used to evaluate potential acute effects of azoxystrobin to freshwater invertebrates. Relative to the parent compound, the degradates tested yield non

- definitive endpoints when testing a t concentrations several orders of magnitude higher than studies with the TGAI. Based on these studies, the degradates are categorized as practically nontoxic to freshwater inve rtebrates on an acute exposure basis.



## Freshwater Invertebrates, Chronic Effects

A laboratory toxicity study using the TGAI was submitted to establish the chronic toxicity of azoxystrobin to freshwater invertebrates. Results of the full lifecycle study with D

. magna indicate a NOAEC value of 0.044 mg a.i./L based on reduced young produced per adult ( Table

III.1 7 ). The NOAEC i s used to evaluate potential chronic effects of azoxystrobin to freshwater

invertebrates.

Table III.16 . Freshwater Invertebrate Acute Toxicity Profile for Azoxystrobin and its Degradates.

Species % a.i. EC 50 mg a.i./ L
(95% Confidence Interval) Toxicity Category MRID No.

Author/Year Study

Classification

Water flea

( Daphnid

magna ) 96.2 0.26

( 0.126

- 0.644 mg a.i./L ) Highly

toxic 43678116
Rapley et al

. 1994 Acceptable

99 >50 mg Compound 28 /L Practically

nontoxic 44158801 &

44158802

Hamer 1996 Acceptable 98 >50 mg Compound 30 /L

98 >190 mg Compound 2 /L Practically

nontoxic 44158804

Kent et al. 1993 Acceptable

### 35 Table III.17

. Freshwater Invertebrate Chronic Toxicity Profile for Azoxystrobin.

Species % a.i. NOAEC

/ LOEAC (mg a.i./L) Endpoint

Affected MRID No.

Author/Year Study

Classification

Water flea

(Daphnia magna) 96.2 0.044 / 0.084 Reproduction (young per adult) 43678121

Rhodes et al

. 1994 Acceptable



## Estuarine/Marine Fish, Acute Effects

A study using the TGAI was submitted to establish the acute toxicity of azoxystro bin to the

estuarine/marine sheepshead minnow ( Cyprinodon variegatus ) . Results of the acute study

indicate an LC 50 

### value of 0.67 mg a.i./L ( Table III.1 8 ), which categorizes azoxystrobin as highly

toxic to estuarine/marine fish on an acute exposure basis . The LC 50 

### value of 0.67 mg a.i./L i s used to evaluate potential acute effects of azoxystrobin to estuarine/marine fish.



## Estuarine/Marine Fish, Chronic Effects

No chronic toxicity data are available for estuarine/marine fish ; therefore, a n acute

- to

- chronic ( ACR ) approach was used to estimate the chronic toxicity to estuarine/marine fish

. The ACR based on acute and chronic toxicity data for freshwater fish is 3.19 mg ai/L

. Applying this ACR

to the sheepshead acute toxicity value ( LC 50 

### of 0.67 mg a.i./L ) results i n a chronic toxicity

estimate of 0.21 mg a.i./L for estuarine/marine fish. The NOAEC of 0.21 mg a.i./L i s used to evaluate potential chronic effects of azoxystrobin to estuarine/marine fish.



## Estuarine/Marine Invertebrates, Acute Effects

Toxicity studies using the TGAI were submitted to establish the acute toxicity of azoxystrobin to

estuarine/marine invertebrates. Results of the acute studies indicate the lowest LC 50 

### /EC 50 

### value

for estuarine/marine invertebrates to be 0.056 mg a.i./L ( Table III. 19 ). As a result, azoxystrobin is categorized as very highly toxic to estuarine/marine invertebrates. The LC 50 

### of 0.056 mg a.i./L was used to evaluate potential acute effects of azoxystrobin to estuarine/marine invertebrates.

Table III.18 . Estuarine/Marine Fish Acute Toxicity Profile for Azoxystrobin.

Species %

a.i. LC 50 mg a.i./ L
(95% Confidence Interval) Toxicity Category MRID No.

Author/Year Study

Classification

Sheepshead minnow

(Cyprinodon variegates) 96.2 0.67

( 0.56

- 0.8 mg a.i./L ) Highly

toxic 43678117
Sankey et al

. (1992) Acceptable

### 36 Table III.19

. Estuarine/Marine Invertebrate Acute Toxicity Profile for Azoxystrobin.

Species %

a.i. LC 50 /EC 50 mg a.i./ L (95% Confidence Interval) Toxicity Category MRID No.

Author/Year Study

Classification

Mysid shrimp

(Mysidopsis bahia) 96.2 0.05 6

(0.035

- 0.11 mg a.i ./L) Very highly

toxic 43678118

Kent et al

. 1993 Acceptable

Pacific oyster
[shell deposition]

( Crassostrea gigas ) 96.2 1. 3

(1.1

- 1.4 mg a.i./L) Moderately

toxic 43678119

Kent et al

. 1993 Acceptable



## Estuarine/Marine Invertebrates, Chronic Effects

A laboratory toxicity study using the TGAI was submitted to establish the chronic toxicity of azoxystrobin to estuarine/marine invertebrates. Results of the life

- cycle study with mysid shrimp ( Americamysis bahia ) indicate a NOAEC of 0.0095 mg a.i./L based on reduced number of young produced per adult and reduced survival ( Table III.2 0 ). The NOAEC i s used to evaluate potential chronic effects of azoxystrobin to estuarine/marine invertebrates.

Table III.20 . Estuarine/marine Invertebrates Chronic Toxicity Profile for Azoxystrobin.

Species % a.i. LOEAC /

NOAEC (mg a.i./L) Endpoint

Affected MRID No.

Author/Year Study

Classification

Mysid shrimp ( Americamysis

bahia formerly Mysidopsis bahia) 96.2 0.016 / 0.0095 Reproduction (young per adult)

and survival 44452302

Boeri et al

. 1997 Acceptable



## Effects to Aquatic Vascular and Non

- vascular Plants

Azoxystrobin studies were submitted for a freshwater vascular plant (duckweed, Lemna gibba ) and four phytoplanktonic nonvascular plants: green algae ( Pseudookirchneriella subcapitata ), cyanobacteria ( Anabaena flos

- aquae ), freshwater diatom ( Navicula pelliculosa ) and the marine alga ( Skeletonema costatum ) ( Table III.2 1 ).

Aquatic plant toxicity studies using the TGAI and a TEP ( Renown ® 

### Fungicide ) were submitted to establish the toxicity of azoxystrobin to vascular and non

- vascular species. T esting with

duckweed yielded an EC 50 

### and NOAEC of 3.4 and 0.8 mg a.i./L, respectively ( Table III.21 )

. T he most sensitive EC 50 

### for aquatic nonvascular plants studies was for N. pelliculosa with EC 50 

### and NOAEC of 0.049 and 0.02 mg a.i./L , respectively. The most sensitive EC 50 

### and NOAEC values for vascular and nonvascular aquatic plants are used to evaluate potential effect of azoxystrobin to non

- listed and listed aquatic plants , respectively

.

Toxicity testing with TEP indicates that green algae is several orders of mag nitude more

sensitive to Renown ® 

### (EC 50 

### = 0.0053 mg a

. i

. /L) compared to the azoxystrobin TGAI (EC 50 

### = 0.106 mg a

. i

. /L). When the formulation toxicit y value is adjusted to the other active ingredient, chlorothalonil, the value (0.098 mg a.i./L) is similar to the acute toxicity value for chlorothalonil

### 37 TGAI (0.19 mg a.i./L (MRID 42432801)), indicating that the enhanced toxicity of Renown ®


### compared to TG AI azoxystrobin is likely due to the presence of chlorothalonil.

Table III.21 . Aquatic Plant Toxicity Profile for Azoxystrobin and its Formulated Product

.

Species % a.i. EC 50 mg a.i./L
( 95% Confidence Interval ) NOAEC mg a.i./L MRID No.

Author/Year Study

Classification

Vascular Plants

Duckweed

( Lemna gibba ) 96.2 3.4

( 3.0

- 3.9 mg a.i./L ) 0.8 43678165
Smyth et al

. 1993 Acceptable

Non

- Vascular Plants

Freshwater green algae

( Pseudokirchneriella subcapitata formerly

Selenastrum capricornutum ) 96.2 0.106

( 0.092

- 0.121 mg a.i./L ) <0.025

(EC 05 = 0.023) 43678161
Smyth et al

. 1994 Acceptable

TEP

2.94 0.0053

(0.0039

- 0.007 mg a.i./L) 0.0026 4886060 6
Dengler 2010 Supplemental 1

Freshwater blue

- green algae ( Anabaena flos

- aquae ) 96.2 13

( 12

- 14 mg a.i./L ) 9 43678162
Smyth et al

. 1994 Acceptable

Marine diatom ( Skeletonema costatum ) 96.2 0.453

( 0.386

- 0.532 mg a.i./L ) 0.1 43678163
Smyth et al

. 1994 Acceptable

Freshwater diatom ( Navicula pelliculosa ) 96.2 0.04 9 

### (0.043

- 0.058 mg a.i./L) 0.02 43678164
Smyth et al

. 1994 Acceptable

1 Only three replicates per level were used; guideline requires 4 replicates per level.



### III .3 .2. Terrestrial Effects Characterization

The most sensitive acute and chronic effects measurement endpoints associated with azoxystrobin exposure to terrestrial species are summarized in Table III

. 22

. Selected effects endpoints for the risk assessment are from acceptable and supplemental studies for azoxystrobin and are described

below.

Overall, azoxystrobin is practically nontoxic to birds on an acute oral and subacute dietary

exposure basis. Azoxystrobin caused no significant mortality or sub

- lethal effects up to and including oral doses of 2 ,000 mg a.i./kg bw and dietary concentrations of 5 200 mg a.i./kg diet. In addition, birds also serve as surrogates for reptiles and terrestrial

- phase amphibians in the absence

of taxa

- specific data; therefore, using the acute toxicity data for birds , azoxy strobin is classified as practically nontoxic to reptiles and terrestrial

- phase amphibians on an acute oral and subacute dietary exposure basis

. Following chronic exposure, reproductive e ffects were reported at 3000 mg a.i./kg diet; the resulting NOAE L w as 1 2 00 mg a.i./kg diet.

### 38 Azoxystrobin is practically nontoxic to mammals on an acute oral basis ( LD 50 

### >5,000 mg a.i/kg

bw) . In the chronic 2

- generation studies with laboratory rats ( Rattus norvegicus )

, growth effects were reported at 165.4 mg a.i./kg/day ( NOAEL = 32.3 mg a.i./kg/day), based on decreased body weight gains for pups

.

Results of the honey bee acute contact and oral test s with azoxystrobin and the formulated product Heritage ® 

### Fungicide ( 50% azoxystrobin ; EPA Reg

. No. 100

- 1093 ) indicate the active ingredient

content is practically nontoxic to young adult honey bees (LD 50 

### ≥ 2 00 μg a.i./bee )

. No data are available to evaluate the toxicity of the TGAI to larval bees.

Effects to t errestrial plants were limited to the seedling emergence stage. C arrot and rape plants were the only species to be inhibited 25% or more resulting in a tier II study. None of the monocotyledonous (monocots) plants were impacted. All monocots and dicot yledenou s (dicots)

at the true 3

- leaf stage (vegetative vigor study) w ere not affected at the limit treatment level of 1.0 lb a.i./A, which was tested higher than the maximum labeled rate of 0.55 lb a.i./A . T he lowest EC 25 

### and NOAEC value obtained in the tier II study was for dicots (carrots) at 0.59 and 0.5 lb a.i./A,

respe ctively.

### 39 Table III.22 . Most Sensitive Endpoints from Acute and Chronic Toxicity Data for Terrestrial Animals and Plants Exposed to Azoxystrobin.

Exposure

Scenario Species Affected Endpoint Toxicity

Measurement MRID (Classification)

Mammals

Acute (Dose

- based) Laboratory rat ( Rattus norvegicus ) Mortality LD 50 >5000 mg a.i./kg

- bw 43678122 (acceptable)

Chronic (Dietary

- based) Decreased pup body weight gain LOAEL = 1500 ppm (165.4 mg/kg/day) NOAEL = 300 ppm (32.3 mg/kg/day) 43678144 (acceptable)

Birds

Acute (Dose

- based) Northern bobwhite quail (Colinus virginianus) Mortality LD 50 >2000 mg a.i./kg bw 43678108 (acceptable)

Canary ( Serinus canaria ) LD 50 >2000 mg a.i./kg bw 49337501 (acceptable)

Acute (Dietary

- based) Northern bobwhite quail (Colinus virginianus) Mortality LC 50 >5200 mg a.i./kg diet 43678111 (acceptable)

Chronic (Dietary

- based) Northern bobwhite quail (Colinus virginianus) Number of eggs laid,

live 3

- week embryos,

and 14

- day old

survivors LOAEC = 3000 mg a.i./kg diet

NOAEC = 1200 mg a.i./kg

- diet 43678113 (acceptable)

Terrestrial Plants

Seedling

emergence All monocots

Growth EC 25 >1.0 lbs a.i./A

NOAEC = 1.0 lbs

a.i./A 43678160 (acceptable) Carrot (dicot) EC 25 = 0.59 lbs

a.i./A

NOAEC = 0.5 lbs

a.i./A

Vegetative Vigor All species EC 25 >1.0 lbs a.i./A

NOAEC = 1.0 lbs

a.i./A 43678158

43678159 (acceptable)

Terrestrial Invertebrates Acute (Contact

based)

Honey bee Mortality via contact LD 50 >200 μg

a.i./bee 43678166 (acceptable) Acute (Oral

based) Adult

Mortality via oral LD 50 >25 μg

a.i./bee

Larval No data No data

Chronic (Oral

based) Adult No data No data

Larval No data No data



## Birds, Acute Oral

Acute oral toxicity studies using the TGAI are required to establish the acute toxicity of azoxystrobin to birds. The submitted acute data indicate that the TGAI is categorized as practically

### 40 nontoxic to upland game birds

, i.e ., Bobwhite quail ( Colinus vir ginianus ), and passerines

, i.e

., canaries ( Serinus canaria ) with LD 50 

### value s >2000 mg a.i./kg bw, the maximu m dose tested, and

no effects to waterfowl

, i.e

., mallard ducks ( Anas platyrhynchos ), were observed at up to 250 mg a.i./kg bw ( Table III.2 3 ). Thus, with no mortality at doses as high as 2,000 mg a.i./kg

- bw in the acceptable studies, the LD 50 

### s of >2000 mg a.i./kg

- bw were used to evaluate potential acute effects

of the TGAI to birds via the oral route of exposure . The available avian acute oral toxicity data are

summarized in Table III.23

.

Table III.23 . Avian Acute Oral Toxicity Profile for Azoxystrobin.

Species %

a.i. LD 50 

### (mg a.i./kg bw) Toxicity Category MRID No.

Author/Year Study

Classification

Canary

( Serinus canaria ) 99.2 >2000 Practically

nontoxic 49337501

Hubbard PM, Beavers JB.

2014. Acceptable

Mallard duck

( Anas platyrhynchos ) 96.2 >250 No effects up to 250 mg a.i./kg

bw 43678109

Hakin, Johnson, Anderson, Dawe (1992) Supplemental 1

Northern bobwhite quail

(Colinus virginianus) 96.2 >2000 Practically

nontoxic 43678108

Hakin, Johnson, Anderson, Dawe (1992) Acceptable

1 Test birds in the three highest treatment groups regurgitated within an hour of dosing. An accurate LD 50 could not be determined; thus, a LD 50 of > 250 mg/kg (the lowest dose) since the actual dosage each bird received above 250 mg/kg is unknown due to vomiting.



## Birds, Subacute Dietary

Dietary studies using the TGAI are required to establish the subacute toxicity of azoxystrobin to birds. The submitted data indicate no mortality occurred and the sub acute dietary LC 50 

### for duck and quail were both >5200 mg a.i./kg diet, the maximum dietary concentrations tested. The TGAI is categorized as practically non

- toxic to upland game birds and waterfowl on a subacute dietary basis ( Table III.2 4 ). Therefore, the LC 50 

### value of >5200 mg a.i./kg

- diet was used to evaluate potential effects of the TGAI to birds following subacute dietary exposure . The available avian subacute dietary studies are summarized in Table III.2 4

.

Table III.24 . Avian Suba cute Dietary Toxicity Profile for Azoxystrobin

Species %

a.i. Nominal LC 50 (mg a.i./kg diet) Toxicity Category MRID No.

Author/Year Study

Classification

Mallard duck

( Anas platyrhynchos ) 96.2 >5200 Practically

nontoxic 43678111

Hakin et al

. 1992 Acceptable

Northern bobwhite quail

(Colinus virginianus) 96.2 >5200 Practically

nontoxic 43678110

Hakin et al

. 1992 Acceptable

### 41 

## Birds, Reproduction

Avian reproduction studies using the TGAI are required to establish the chronic toxicity of azoxystrobin to birds ( Table III.2 5 ). A NOAEC of 1200 mg a.i./kg diet f or both species i s used to evaluate potential chronic effects of the TGAI to birds.

Table III.25 . Avian Chronic Toxicity Profile for Azoxystrobin.

Species %

a.i. NOAEC / LOAEC (mg a.i./kg

- diet) Affected endpoints MRID no.

Author/Year Study

classification

Northern bobwhite quail

(Colinus virginianus) 96.2 1200/3000 Number of eggs laid, eggs set, viable embryos, live 3

- week

embryos, normal hatchling, and 14

- day

old survivors 44452301
Gallagher et al

. 1997 Acceptable

Mallard duck

( Anas platyrhynchos ) 96.2 1200/3000 Number of eggs laid 43678113

Cameron et al.

1994 Acceptable



## Mammals, Acute Oral

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 in Table III.2 6

.

Results of the acute oral study with rats indicate azoxystrobin is categorized as practically nontoxic (LD 50 

### >5000 mg a.i/kg

- bw) to small mammals on an acute oral exposure basis. The LD 50 

### value of >5000 mg a.i./kg

- bw i s used to evaluate potential acute effects to mammals.

Table III.26 . Mammalian Acute Oral Toxicity Profile for Azoxystrobin.

Species % a.i. Test Type LD 50 (mg a.i./kg bw) Affected Endpoints MRID No. Author, Year Study

Classification

Rat (Wistar) 95.2 acute oral LD 50 >5000 None 43678122

Robinson (1991) Acceptable



## Mammals, Chronic

In a 2

- generation study of rats ( Table III.2 7 ), azoxystrobin (96.2% a.i.) resulted in a treatment

related reduction ( ↓ 8

- 21%) in adjusted (for initial weight) pup body weights in the F 1a 

### and F 2a 

### pups dosed at 1500 ppm ( 165.4 mg/kg bw /day). The corresponding NOAEL is 300 ppm (3 2. 3 mg/kg/day).

### 42 Table III.27 . Mammalian Reproductive Toxicity Profile for Azoxystrobin

.

Species % a.i. Test Type Toxicity ppm (mg a.i./kg bw/day) Affected Endpoints MRID No.

Rat (Wistar) 96.2 2

- generation Reproduction NOAEL = 300 (32.3)

LOAEL = 1500 (165.4) Decreased pup body weight 43678144 (acceptable)



## Terrestrial Invertebrates, Acute

Acute contact and oral honey bee studies with adult bee s and their larvae exposed to azoxystrobin

are used to establish the toxicity of the TGAI to terrestrial invertebrates because of outdoor uses that will result in exposure. The submitted data ( Table III.2 8 ) with the TGAI and Heritage ®


### Fungicide ( 50% azoxystrobin ; EPA Reg No. 100

- 1093 ) indicate no significant mortality occurred

in the studies and the acute contact LD 50 

### for adult bees for both test materials were >200 μg a.i./bee,

the maximum concentrations te sted, while the oral LD 50 

### s for adult bees exposed to the TGAI and formulated product Heritage ® 

### Fungicide w ere >200 and >25 μg a.i./bee, respectively. The TGAI is categorized as practically non

- toxic to adult bees on a n acute contact and dietary exposure basis

, and because no definitive endpoint was identified for the formulated product, its relative toxicity

could not be discerned

. Therefore, the acute contact and acute oral L D 50 

### value s of >200 μg a.i./bee

are used to evaluate potential acute effects of the TGAI to b ees via contact from foliar sprays and through ingestion of residues in pollen and nectar

. Although azoxystrobin is practically non

- toxic to adult bees on an acute exposure basis, there is uncertainty regarding the potential acute effects

of a zoxystrobin on bee larvae.

Table III.28

. Honey bee Acute Toxicity Profile for Azoxystrobin.

Species % a.i. Life Stage LD 50 (μg a.i./bee) Toxicity Category MRID No. Study

Classification

Honey bee ( Apis mellifera ) 96.2 Adult >200 (contact) Practically

nontoxic 43678166 Gough et al

. 1993 Acceptable

>25 (oral) Practically

nontoxic Acceptable

Herita

ge ®

51.6 Adult >200 (contact) Practically

nontoxic 43678167 Gough and

Jackson 1994 Acceptable

>200 (oral) Practically

nontoxic Acceptable

N/A Larval No data N/A N/A N/A



## Terrestrial Invertebrates, Chronic

Chronic honey bee toxicity studies with larval and adult bees exposed to azoxystrobin are

necessary to establish the toxicity of the TGAI to terrestrial invertebrates because of outdoor uses that will result in exposure; however, no chronic toxicity studies with adult or larval honey bees

have been submitted. Therefore, there is uncertainty regarding th e effects of azoxystrobin on both adult bees and their brood (larvae and pupae) as a result of chronic (repeat) exposure

.

### 43 

## Terrestri al Plants

Terrestrial plant studies are required for all terrestria l outdoor pesticides. Tier I terrestrial plant

toxicit y studies were conducted to establish the toxicity of the TEP, Heritage ® 

### Fungicide (EPA Reg No. 100

- 1093

, 50% azoxystrobin ) , at the maximum limit dose of 1.0 lb a.i./A to non

- target terrestrial plants ; the TEP was tested at rates higher than the maximum

- labeled single application

rate of 0. 55 lb a.i./A.

The recommendations for seedling emergence and vegetative vigor studies are for testing of (1) six species of at least four dicot 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 ).

In Tier I testing , seedling emergence of most of the test s pecies

— except for two dicot species

, carrot ( Daucus carota ) and rape ( Brassica napus )

-- w as not inhibited 25% or more by the formulated product

, at the limit dose. Emergence of carrot and rape plants in the Tier I seedling emergence study were inhibited by more than 25% ( Table III.29 ) ; Tier II tests were conducted for both of these species. EC 25 

### and NOAEC values for the Tier II study is reported in Table III.30

. Since carrots were the most sensitive species tested in that study

, the EC 25 

### of 0.59 lb a.i./A and its corresponding NOAEC of 0.5 lb a.i./A a re used to estimate risk s for seedling emergence of non

listed and listed terrestrial plants in dry and semi

- aquatic areas adjacent to site s treated with azoxystrobin and exposed to residues of azoxystrobin in surface water runoff and spray drift

.

In the Tier I vegetative vigor studies, n one of the monocot or dicot plants were inhibited 25% or

more at the limit dose

. Testing was repeated with rape (MRID 43678159) because rape plants had been treated with another pesticide during the course of the original study. R esults of these studies

are summarized in Table s III.31 and III.32

. EC 25 

### value s were all >1.0 lb a.i./A and a Tier II vegetative vigor study was not necessary. With no significant effects to the tested plants in the vegetative vigor study , the limit dose i s used as the endpoint to assess risk to non

- listed and listed terrestrial plants in dry and semi

- aquatic areas adjacent to a treated site exposed to azoxystrobin

residues via downwind spray drift

.

### 44 

## Terres trial Plants, Seedling Emergence

Tier I

Table III.29 . Summary of Tier I Seedling Emergence Results for Heritage ® 

### Fungicide *

Species Most

sensitive endpoint %

Inhibition Nominal EC 25 (lb a.i./A) Nominal NOAEC (lb a.i./A) Study

Classification

Corn Dry weight 14.4 >1.0 1.0 Acceptable

Meadow

fescue Damage 8.6 >1.0 1.0 Acceptable

Purple nutsedge Dry weight 5.3 >1.0 1.0 Acceptable

Wheat Dry weight 24.6 >1.0 1.0 Acceptable

Wild oat 1

- - >1.0 1.0

--

Carrot Damage 33.2**

- -
Cocklebur Damage 16.1 >1.0 1.0 Acceptable

Morning

glory Dry weight 10.1 >1.0 1.0 Acceptable

Rape Dry weight 27.2** >1.0 1.0 Acceptable

Soybean Damage 10.2 >1.0 1.0 Acceptable

Sugar beet Dry weight 11.2 >1.0 1.0 Acceptable

Velvetleaf Dry weight 14.8 >1.0 1.0 Acceptable

* 48 % a.i azoxystrobin , tested at the limit dose of 1.0 lb a.i./A; MRID 43678156

, Canning et al . 1994

. ** Tier II testing is required for this species for which emergence was inhibited at or greater than 25%.

1 Poor germination at 17% made it difficult to adequate assess inhibition in wild oats; thus, results are not reported. T his would be considered a data gap ; however, because seedling emergence data are required for only 10 species, repeating the

test with wild o ats is not necessary.



### Tier II

Table III.30 . Summary of Tier II Seedling Emergence Toxicity Profile for Azoxystrobin. A

Species Most Sensitive Endpoint NOAEC EC 05 EC 25 Study Classification

Carrot Dry weight 0.5 0.37 0.59 Acceptable Rape Emergence 1.0 0.55 3.2 Acceptable

A 51.6 % a.i; MRID 43678160

, Everett et al . 1995.

### 45 

## Terrestrial Plants, Vegetative Vigor

Tier I

Table III.3 1 . Summary of Tier I Vegetative Vigor Results for Heritage ® 

### Fungicide *

Species Most

sensitive endpoint %

Inhibition Nominal EC 25 (lb a.i./A) Nominal NOAEC (lb a.i./A) Study

Classification

Corn Dry weight 8.7 >1.0 1.0 Acceptable Purple nutsedge Dry weight 2.9 >1.0 1.0 Acceptable

Wheat Dry weight 4.9 >1.0 1.0 Acceptable

Wild oat Dry weight 11.4 >1.0 1.0 Acceptable

Cocklebur Damage 0.3 >1.0 1.0 Acceptable Morning

glory None 0.0 >1.0 1.0 Acceptable

Rape Dry weight 6.7

- - Invalid 1
Soybean Damage 0.3 >1.0 1.0 Acceptable Sugar beet Damage 1.3 >1.0 1.0 Acceptable

Velvetleaf Damage 0.7 >1.0 1.0 Acceptable

* 48 % a.i azoxystrobin , tested at the limit dose of 1.0 lb a.i./A; MRID 43678158

, Canning et al

. 1994

.
1 Rape plants were treated with primicarb to control aphids ; thus, results are not reported

.



### Table III.3 2 . Summary of Tier I Vegetative Vigor Results for Azoxystrobin 50 WG *

Species Most

sensitive endpoint %

Inhibition Nominal EC 25 (lb a.i./A) Nominal NOAEC (lb a.i./A) Study

Classification

Rape Damage 5.7 >1.0 1.0 Acceptable

* 51.6 % a.i azoxystrobin , tested at the limit dose of 1.0 lb a.i./A; MRID 43678159; Everett et al

. 1995

.



## Ecological Incidents

A review of the Ecological Incident Information System (EIIS) maintained by the Agency’s Office

of Pesticide Programs (OPP) indicates a total of 36 reported ecological incidents associated with

the use of azoxystrobin ( Table III. 33 ) . The reported incidents involved damage mainly to terrestrial plants. Incidents were associated with misuse or registered use s of azoxystrobin as a

result of off

- site spray drift or direct treatments . In addition, there a re 40 aggregate incident s including 3 ‘Other Non

- Target’ incidents reported for azoxystrobin that were reported by the pesticide registrant.

There is one incident to birds (bald eagle ; Haliaeetus leucocephalus ) as a result of indirect poisoning. The repo rt states the chemical analysis of the crop contents showed the presence of carbofuran and azoxystrobin. The certainty was highly probable for carbofuran and unlikely for azoxystrobin ; however

, it was undetermined if the pesticides were used legally

. The A vian Incident Monitoring System (AIMS) database also reported the bald eagle incident.

### 46 Table III.13. Summary of Ecological Incidents Associated with Azoxystrobin Uses, By Crop

. Incident

# Species Response Exposure Certainty Legality Formulation Appl.

Method Magnitude



### Plants Agricultural Area

I009314

- 004 apple plant damage drift Probable Misuse N/R m ist

blower 3.5 acres

I009314

- 001 apple plant damage drift Possible Undetermi

ned F b roadcast 450 trees

I009314

- 003 apple plant damage drift Probable Misuse N/R mist

blower 150 to 175

trees

I021500

- 071 tobacco plant damage treated directly N/R N/R N/R N/R 6.7 acres

I021500

- 072 tobacco plant damage treated directly N/R N/R N/R N/R 32 acres

I021500

- 073 tobacco mortality treated directly N/R N/R N/R N/R 12.87 acres

I021500

- 074 field corn plant damage N/R N/R N/R N/R N/R N/R

I021500

- 075 field corn plant damage treated directly N/R N/R N/R N/R 35 acres

Apple

I009314

- 002 apple plant damage N/R Possible Misuse F spray 16 acres

I020627

- 012 apple plant damage drift Highly probable undetermi

ned N/R N/R 4 acres

Corn

I019130

- 070 corn plant damage carryover Probable Undetermi

ned N/R broadcast 400 acres

Grape

I009314

- 026 imperial gala apple plant damage drift Probable Misuse F N/R 15 acres

N/R

I014597

- 001 tobacco plant damage N/R Possible Undetermi

ned F N/R 6 acres

I009314

- 022 apple plant damage drift Probable Misuse N/R N/R 27 acres

I009314

- 023 apple plant damage drift Possible Misuse N/R N/R 3 acres

I009314

- 024 apple plant damage drift Probable Misuse N/R N/R 1.5 acres

I009314

- 025 apple plant damage drift Probable Misuse N/R N/R unknown

Orchards

I008384

- 407 apple plant damage N/R Probable Registered

Use N/R N/R N/R

I008384

- 408 apple mortality N/R Probable Registered

Use N/R N/R N/R

I008384

- 409 apple mortality N/R Probable Registered

Use N/R N/R N/R

I008384

- 410 apple mortality N/R Probable Registered

Use N/R N/R N/R

### 47 Table III.13. Summary of Ecological Incidents Associated with Azoxystrobin Uses, By Crop

. Incident

# Species Response Exposure Certainty Legality Formulation Appl.

Method Magnitude

I008384

- 411 apple mortality N/R Probable Registered

Use N/R N/R N/R

I008384

- 412 apple mortality N/R Probable Registered

Use N/R N/R N/R

I008384

- 413 apple mortality N/R Probable Registered

Use N/R N/R N/R

I008384

- 414 apple mortality N/R Probable Registered

Use N/R N/R N/R

I008384

- 415 apple mortality N/R Probable Registered

Use N/R N/R N/R

I008384

- 416 apple mortality N/R Probable Registered

Use N/R N/R N/R

I008384

- 417 apple mortality N/R Probable Registered

Use N/R N/R N/R

Ornamentals

I013612

- 007 cypress plant damage treated directly Probable Registered

Use WDG 434

Peanut

I016903

- 001 peanut plant damage treated directly Possible Registered

Use F broadcast 80 acres

Soybean

I015713

- 083 soybean plant damage treated directly Possible Registered

Use DF broadcast 88 acres

Sugar beet

I015713

- 001 sugar beet mortality treated directly Possible Registered

Use N/R band 222 acres

I015713

- 002 sugar beet plant damage treated directly Possible Registered

use N/R band 532 acres

I015713

- 003 sugar beet mortality treated directly Possible Registered

Use N/R band 664 acres

Terrestrial Use site not reported

I018723

- 002 bald eagle incapacitati

on ingestion unlikely Undetermi

ned N/R N/R 1 bird

N/R

- not reported ; F

– flowable ; WDG

– water dispersible granule; DF

– dry flowable



# IV. RISK CHARACTERIZATION

Risk characterization provides the final step in the risk assessment process. In this step, exposure

and effects data are integrated to provide an estimate of risk relative to Agency’ s established levels of concern (LOCs). The results are then interpreted for the risk manager through a risk description and synthesized into an overall conclusion.



## IV.1. Risk Estimation

- Integration of Exposure and Effects Data

A deterministic (poin t estimate) approach is used to evaluate the likelihood of adverse ecological

effects to non

- target species. In this approach, risk quotients (RQs) are calculated by dividing

### 48 acute and chronic point estimates of exposure ( EECs) by acute and chronic point estimates of toxicity for non

- target species.

RQ = EXPOSURE/TOXICITY

RQs are then compared to LOCs used by the Agency to indicate potential risk to non

- target wildlife and the need to consider regulatory action. Exceedance of the LOC by the RQ indicates that a pesticide used as directed has the potential to cause adverse effects on non

- target wildlife. LO Cs currently address the following risk presumption categories: (1) acute risk

- potential for acute

risk to non

- target animals which may warrant regulatory action in addition to restricted use classification, (2) acute restricted use

– potential for acute risk to non

- target animals, but may be mitigated through restricted use classification, (3) acute listed species

– listed species may be potentially affected by use, (4) chronic risk

– potential for chronic risk may warrant regulatory action, listed speci es may potentially be affected through chronic exposure, (5) non

- listed plant

risk

- potential for effects in non

- target (non

- listed) plants, and (6) listed plant risk

– potential for effects in listed plants.

For acute studies on taxa where a definiti ve LC 50 

### /LD 50 

### /EC 50 

### is not established due to insufficient mortality or no effects were observed, an RQ was not calculated, and the study is discussed further in the Risk Description section.

Risk presumptions, along with the basis for deriving RQs and LOCs are tabulated below in Tables IV.1, IV.2, and IV.3 :

Table IV.1. Risk Presumptions for Terrestrial Animals

Risk Presumption RQ LOC

Birds :
Acute Risk EEC 1 /LC 50 or LD 50 /sq ft 2 or LD 50 /day 3 ≥0.5

Acute Restricted Use EEC/LC 50 or LD 50 / sq ft or LD 50 /day (or LD 50 < 50 mg a.i./kg) ≥0.2

Listed Species EEC/LC 50 or LD 50 /sq ft or LD 50 /day ≥0.1

Chronic Risk EEC/NOAEC ≥1

Wild Mammals :
Acute Risk EEC/LC 50 or LD 50 /sq ft or LD 50 /day ≥0.5

Acute Restricted Use EEC/LC 50 or LD 50 /sq ft or LD 50 /day (or LD 50 < 50 mg a.i./kg) ≥0.2

Listed Species EEC/LC 50 or LD 50 /sq ft or LD 50 /day ≥0.1

Chronic Risk EEC/NOAEC ≥1

Invertebrates: Listed Species EEC/LD 50 ≥0.4

Chronic Risk EEC/NOAEC ≥1

1 EEC=abbreviation for Estimated Environmental Concentration (mg a.i./kg) on avian/mammalian food items

2 mg/ft 3 mg of toxicant consumed/day

LD 50 * wt. of bird LD 50 * wt. of bird



### Table IV.2. Risk Presumptions for Aquatic Animals

Risk Presumption RQ LOC

Acute Risk EEC 1 /LC 50 or EC 50 ≥0.5

Acute Restricted Use EEC/LC 50 or EC 50 ≥0.1

### 49 Table IV.2. Risk Presumptions for Aquatic Animals

Risk Presumption RQ LOC Acute Listed Species EEC/LC 50 or EC 50 ≥0.05

Chronic Risk EEC/NOAEC ≥1

EEC = (mg a.i./L or μg a.i./L) in water



### Table IV.3. Risk Presumptions for Plants

Risk Presumption RQ LOC

Terrestrial Plants in Terrestrial and Semi

- Aquatic Areas:

Non

- Listed Plant Species EEC 1 /EC 25 ≥1 Listed Plant Species EEC/NOAEC or EC 05 3 ≥1 Aquatic Plants:

Non

- Listed Plant Species EEC 2 /EC 50 ≥1 Listed Plant Species EEC/NOAEC or EC 05 3 ≥1

1 EEC = lbs a.i./acre 2 EEC = (μg a.i./L or mg a.i./L) in water

3 An EC 05 is only used when a definitive NOAEC is not available.



### The following section presents the acute and chronic risk quotients calculated for azoxystrobin

and indicates whether LOCs are exceeded. Further discussion of the risk quotients and

uncertainties i n the assessment is presented in Section IV .2

.

IV.1.1

. Non

- target Aquatic Organisms

Tables IV.4 thru IV

. 11 list acute and chronic RQs calculated for aquatic organisms (freshwater

fish a re surrogates for aquatic

- phase amphibians) exposed to azoxystrobin based on the EECs generated from SWCC modeling for foliar sprays and EECs from GENEEC and tier I Rice modeling for seed treatment s

.

Depending on the use site, r esults of the assessment on a quatic organisms indicate acute and/ or chronic risk LOC exceedances for fish and /or invertebrates exposed to azoxystrobin via foliar applications and seed treatments ( Table s IV.4 and IV.5

– freshwater fish

, Tables IV.6 and IV.7

– freshwater invertebrates

, Table s IV.8 and IV.9

– estuarine/marine fish; and Table s IV.10 and

IV.11

- est uarine/marine invertebrates).

As part of the analysis plan discussed in the preliminary problem formulation, to address the gap about the number of crop cycles per year for several use sites , 1 and 3 crop cycles per year were

modeled for this assessment , each cycle with applications of azoxystrobin . As a result, modeling for leafy vegetable use s (i.e., lettuce, pepper, bean, melon, asparagus and tomato) with three crop cycles per year yields the highest EECs of all use scenarios. RQs may exceed LOCs for particular

use sites with three crop cycles per year

, but not necessar il y for 1 or 2 crop cycles per year

. Also, if there are no LOC exceedances for leafy vegetables after three application cycles, exceedances are not expected for all other uses with lower EECs.

Additionally, for azoxystrobin

- treated seeds, modeling for rice yields the highest EECs of all seed treatments. Thus, if rice uses do not results in LOC exceedances , there are no LOC exceedances

for all other uses with lower EECs , which apply to many taxa.

### 50 For foliar applications, e xcept for use s on wheat and peanuts, other uses modeled exceed the acute risk to listed species LOC (RQ>0.05) of freshwater fish; howe ver, none of the uses modeled exceed

the acute risk to non

- listed species LOC of 0.5 ( Table IV.4 ). Except for use on peppers where 3 cycles per year were modeled, RQ values are below the chronic risk LOC of 1.0 for freshwater

fish. Estimated run

- off from seed treatments does not exceed acute or chronic risk LOCs ( Table

IV.5 )

For listed species, LOC exceedances from foliar sprays require an additional in

- depth listed species evaluation of the potential co

- occurrence of listed species in azoxystrobin

- treat ed areas to

characterize risks. This step has not been undertaken for this assessment.

The potential adverse effects to fish and invertebrates are discussed further in Section IV

. 2.

### 51 F reshwater Fish

- Foliar Spray

Table IV.4 . Risk Quotients for Freshwater Fish via Foliar Sprays

Crop Scenario Use Pattern ( lb a.i./A x days

interval x no. of

applications ) 1

- in

- 10

-
year Peak EEC

( μg /L) Freshwater Fish

LC 50 = 470 μg a.i./L 1

- in

- 10

- year 60

- day EEC ( μ g/L) Freshwater Fish

NOAEC = 147 μg a.i./L Acute RQs Chronic RQs

Turf FLturf 0.55 x 14 x 9 43.7 0.09 * 40.3 0.3

PAturf 32.9 0.07 * 31.1 0.2

Corn IAcorn

0.25 x 7 x 4 24.3 0.05 * 22.1 0.2

ILcorn 30.9 0.07 * 27.8 0.2

INcorn 24.9 0.05 * 23.1 0.2

KScorn 41.1 0.09 * 36.6 0.2

MNcorn 29.7 0.06 * 27.6 0.2

MScorn 34.2 0.07 * 31.4 0.2

NCcorn 22.2 0.05 * 20.2 0.1

NEcorn 33.2 0.07 * 30.2 0.2

OHcorn 28.9 0.06 * 26.2 0.2

PAcorn 25.3 0.05 * 24.8 0.2

Peanuts NCpeanut 0.4 x 10 x 2 17.4 0.04 15.7 0.1

Wheat NDwheat 0.2 x 14 x 2 10 0.02 9.2 0.1

Potato IDpotato 0.33 x 7 x 6 32.5 0.07 * 30.9 0.2

MEpotato 52.6 0.11 ** 49.1 0.3

Almond CAalmond 0.25 x 7 x 6 21.5 0.05 * 19.7 0.1

Sugarcane FLsugarcane 0.25 x 14 x 4 29.7 0.06 * 27.2 0.2

LAsugarcane 31.5 0.07 * 28.8 0.2

Lettuce CAlettuce 0.25 x 14 x 6 (1 Crop Cycles /

yea r)

0.25 x 14 x 18 82.3 (3 CC/yr) 0.18 ** 79.3 (3 CC/yr) 0.5

33.5 (1 CC/yr) 0.07 * 31.1 (1 CC/yr) 0.2

Pepper FLpepper 150 (3 CC/yr) 0.32 ** 151 (3 CC/yr) 1.0 †

### 52 Table IV.4 . Risk Quotients for Freshwater Fish via Foliar Sprays

Crop Scenario Use Pattern ( lb a.i./A x days

interval x no. of

applications ) 1

- in

- 10

-
year Peak EEC

( μg /L) Freshwater Fish

LC 50 = 470 μg a.i./L 1

- in

- 10

- year 60

- day EEC ( μ g/L) Freshwater Fish

NOAEC = 147 μg a.i./L Acute RQs Chronic RQs (3 Crop Cycles / year) 

### 50. 6 (1 CC/yr) 0.11 ** 

### 51.1 (1 CC/yr) 0.3

Bean ORbean 11 1 (3 CC/yr) 0.24 ** 

### 110 (3 CC/yr) 0.7

Melon NJmelon 96.7 (3 CC/yr) 0.21 ** 

### 93.1 (3 CC/yr) 0.6

Asparagus MIasparagu s 60 (3 CC/yr) 0.13 ** 

### 56.9 (3 CC/yr) 0.4

Tomato PAtomat o 96.5 (3 CC/yr) 0.21 ** 

### 92.8 (3 CC/yr) 0.6

* RQ meets or exceeds the acute risk listed species LOC of 0.0 5. **RQ exceeds the acute risk listed species LOC of 0.05 and the acute restricted use LOC of 0.1 

### † RQ exceeds the chronic risk LOC of 1.0.

F reshwater Fish

– Seed Treatment

Table IV.5. Risk Quotients for Freshwater Fish via Seed Treatment

Crop Application Rate (lb a.i./A) Rice

Model

Peak EEC

(μg/L) Freshwater Fish

LC 50 

### = 470 μg a.i./L Rice Model

60

- day EEC ( μ g/L) Freshwater Fish

NOAEC = 147 μg a.i./L Acute RQs Chronic RQs

DYNASTY

Rice 1 

### 0.012 6.1 0.01 6.1 <0.1

1 Based on Tier I Rice Model

.



### Because this use, with the highest EECs of all the seed treatment uses, does not yield RQs greater than the LOCs, we can conc lude that none of the other seed treatment uses of azoxystrobin will yield RQs greater than the LOCs.

F reshwater Invertebrates

- Foliar Spray

### 53 With the exception of use on wheat, RQ values exceed the acute risk to listed aquatic invertebrate species and the majority o f uses exceed the restricted use LOC of 0.1 as well ( Table IV.6 ). Use on peppers for 3 cycles per year exceeds the acute risk to non

- listed species LOC of 0.5; whereas, a single crop cycle for peppers does not exceed the acute risk to non

- listed species LOC, but does exceed

the restricted use LOC. With re spect to chronic risk to aquatic invertebrates , potatoes, lettuce, peppers, beans , melons, asparagus and

tomatoes exceed the chronic risk LOC of 1.0. Estimated run

- off from seed treatments does not exceed acute or chronic risk LOCs ( Table IV.7 ).

Table IV. 6 . Risk Quotients for Freshwater Invertebrates via Foliar Sprays

Crop Scenario Use Pattern (lb a.i./A x days

interval x no. of

applications) 1

- in

- 10

- year Peak EEC

(μ g/L) Freshwater

Invertebrates

LC 50 = 260 μg a.i./L 1

- in

- 10

- year 21

- day EEC ( μ g/L) Freshwater

Invertebrates

NOAEC = 44 μg a.i./L Acute RQs Chronic RQs

Turf FLturf 0.55 x 14 x 9 43.7 0.17 ** 42 0.95

PAturf 32.9 0.13 ** 32 0.7

Corn IAcorn

0.25 x 7 x 4 24.3 0.09 * 23.4 0.5

ILcorn 30.9 0.12 ** 29.7 0.7

INcorn 24.9 0.10 ** 24.1 0.5

KScorn 41.1 0.16 ** 39.3 0.9

MNcorn 29.7 0.11 ** 28.6 0.7

MScorn 34.2 0.13 ** 33.3 0.8

NCcorn 22.2 0.09 * 21.3 0.5

NEcorn 33.2 0.13 ** 31.7 0.7

OHcorn 28.9 0.11 ** 27.9 0.6

PAcorn 25.3 0.10 ** 24.8 0.6

Peanuts NCpeanut 0.4 x 10 x 2 17.4 0.07 * 16.6 0.4

Wheat NDwheat 0.2 x 14 x 2 10 0.04 9.69 0.2

Potato IDpotato 0.33 x 7 x 6 32.5 0.13 ** 32.1 0.7

MEpotato 52.6 0.20 ** 51.3 1.2 †

Almond CAalmond 0.25 x 7 x 6 21.5 0.08 * 20.6 0.5

### 54 Table IV. 6 . Risk Quotients for Freshwater Invertebrates via Foliar Sprays

Crop Scenario Use Pattern (lb a.i./A x days

interval x no. of

applications) 1

- in

- 10

- year Peak EEC

(μ g/L) Freshwater

Invertebrates

LC 50 = 260 μg a.i./L 1

- in

- 10

- year 21

- day EEC ( μ g/L) Freshwater

Invertebrates

NOAEC = 44 μg a.i./L Acute RQs Chronic RQs

Sugarcane FLsugarcane 0.25 x 14 x 4 29.7 0.11 ** 28.6 0.7

LAsugarcane 31.5 0.12 ** 30.5 0.7

Lettuce CAlettuce

0.25 x 14 x 6 (1 CC / year)

0.25 x 14 x 18 (3 CC / year) 82.3 (3 CC/yr) 0.32 ** 80.9 (3 CC/yr) 1.8 †

33.5 (1 CC/yr) 0.13 ** 32.5 (1 CC/yr) 0.7

Pepper FLpepper 150 (3 CC/yr) 0.58 *** 152 (3 CC/yr) 3.5 †

50.6 (1 CC/yr) 0.19 ** 49.4 (1 CC/yr) 1.1 †

Bean ORbean 111 (3 CC/yr) 0.43 ** 111 (3 CC/yr) 2.5 †

Melon NJmelon 96.7 (3 CC/yr) 0.37 ** 95.1 (3 CC/yr) 2.2 †

Asparagus MIasparagus 60 (3 CC/yr) 0.23 ** 58.2 (3 CC/yr) 1.3 †

Tomato PAtomato 96.5 (3 CC/yr) 0.37 ** 95.4 (3 CC/yr) 2.2 †

* RQ meets or exceeds the acute risk to listed species LOC of 0.05 .

** 

### RQ exceeds the acute risk to listed species LOC of 0.05 and the acute restricted use LOC of 0.1.

** * 

### RQ exceeds the acute risk to listed species LOC of 0.05, the acute restricted use LOC of 0.1, and the acute risk to listed species LOC of 0.5.

† 

### RQ exceeds chronic risk LOC of 1.0.

.

### 55 F reshwater Invertebrates

– Seed Treatment

Table IV.7. Risk Quotients for Freshwater Invertebrates via Seed Treatment

Crop Application Rate (lb a.i./A) Rice Model

Peak EEC

(μg/L) Freshwater

Invertebrates

LC 50 = 260 μg a.i./L Rice

Model

21

- day

EEC ( μ g/L) Freshwater

Invertebrates

NOAEC = 44 μg a.i./L Acute RQs Chronic RQs

DYNASTY

Rice 1 0.012 6.1 0.02 6.1 0.14

1 Based on Tier I Rice model

.



### For foliar applications, with the exception of peanuts and wheat, RQ values for other modeled uses exceed the acute risk to listed species

LOC for e stuarine/marine fish. Use on potatoes, lettuce, peppers, beans, melons and tomatoes also exceed the acute restricted use LOC ( Table IV.8 ). None of the uses modeled exceed the chronic risk LOC for estuarine/marine fish. Estimated run

- off from seed treatments does not exceed acute or chronic risk LOCs ( Table IV.9 ).

Estuarine/marine Fish

- Foliar Spray

Table IV. 8 . Risk Quotients for Estuarine/marine Fish via Foliar Sprays

Crop Scenario Use Pattern (lb a.i./A x days

interval x no. of

applications) 1

- in

- 10

-
year Peak EEC

(μ g/L) Estuarine/marine

Fish

LC 50 = 670 μg a.i./L 1

- in

- 10

- year 60

- day EEC ( μ g/L) Estuarine/marine Fish

ACR calculated NOAEC

= 210 μg a.i./L

Acute RQs Chronic RQs

Turf FLturf 0.55 x 14 x 9 43.7 0.07 * 40.3 0.19

PAturf 32.9 0.05 * 31.1 0.15

Corn IAcorn

0.25 x 7 x 4 24.3 0.04 22.1 0.11

ILcorn 30.9 0.05 * 27.8 0.13

INcorn 24.9 0.04 23.1 0.11

KScorn 41.1 0.06 * 36.6 0.17

MNcorn 29.7 0.04 27.6 0.13

MScorn 34.2 0.05 * 31.4 0.15

### 56 Table IV. 8 . Risk Quotients for Estuarine/marine Fish via Foliar Sprays

Crop Scenario Use Pattern (lb a.i./A x days

interval x no. of

applications) 1

- in

- 10

-
year Peak EEC

(μ g/L) Estuarine/marine

Fish

LC 50 = 670 μg a.i./L 1

- in

- 10

- year 60

- day EEC ( μ g/L) Estuarine/marine Fish

ACR calculated NOAEC

= 210 μg a.i./L

Acute RQs Chronic RQs

NCcorn 22.2 0.03 20.2 0.10

NEcorn 33.2 0.05 * 30.2 0.14

OHcorn 28.9 0.04 26.2 0.12

PAcorn 25.3 0.04 24.8 0.12

Peanuts NCpeanut 0.4 x 10 x 2 17.4 0.03 15.7 0.07

Wheat NDwheat 0.2 x 14 x 2 10 0.01 9.2 0.04

Potato IDpotato 0.33 x 7 x 6 32.5 0.05 * 30.9 0.15

MEpotato 52.6 0.08 * 49.1 0.23

Almond CAalmond 0.25 x 7 x 6 21.5 0.03 19.7 0.09

Sugarcane FLsugarcane 0.25 x 14 x 4 29.7 0.04 27.2 0.13

LAsugarcane 31.5 0.05 * 28.8 0.14

Lettuce CAlettuce

0.25 x 14 x 6 (1 CC / year)

0.25 x 14 x 18 (3 CC / year) 82.3 (3 CC/yr) 0.12 ** 79.3 (3 CC/yr) 0.38

33.5 (1 CC/yr) 0.05 * 31.1 (1 CC/yr) 0.15

Pepper FLpepper 150 (3 CC/yr) 0.22 ** 151 (3 CC/yr) 0.72

50.6 (1 CC/yr) 0.08 * 51.1 (1 CC/yr) 0.24

Bean ORbean 111 (3 CC/yr) 0.17 ** 110 (3 CC/yr) 0.52

Melon NJmelon 96.7 (3 CC/yr) 0.14 ** 93.1 (3 CC/yr) 0.44

Asparagus MIasparagus 60 (3 CC/yr) 0.09 * 56.9 (3 CC/yr) 0.27

Tomato PAtomato 96.5 (3 CC/yr) 0.14 ** 92.8 (3 CC/yr) 0.44

* RQ meets or exceeds the acute risk to listed species LOC of 0.05 .

** RQ exceeds the acute risk to listed species LOC of 0.05 and the acute restricted use LOC of 0.1.

### 57 Estuarine/marine Fish

– Seed Treatment

Table IV.9. Risk Quotients for Estuarine/marine Fish via Seed Treatment

Crop Application Rate (lb a.i./A) Rice

Model

Peak EEC

(μg/L) Estuarine/marine

Fish

LC 50 

### = 670 μg

a.i./L Rice Model

60

- day EEC ( μ g/L) Estuarine/marine Fish

ACR calculated

NOAEC = 210 μg a.i./L Acute RQs Chronic RQs

DYNASTY

Rice 1 

### 0.012 6.1 <0.01 6.1 <0.1

1 Based on Tier I Rice model

.



### For foliar applications, RQ values for all of the uses modeled exceed the acute risk to listed estuarine/marine invertebrate species LOC and the acute restricted use LOC; the majority of uses also exceed the acute risk to non

- listed species LOC. All of the uses modeled

also exceed the chronic risk LO C.

### 58 Estuarine/marine Invertebrates

- Foliar Spray

Table IV. 10 . Risk Quotients for Estuarine/marine Invertebrates via Foliar Sprays

Crop Scenario Use Pattern (lb a.i./A x days

interval x no. of

applications) 1

- in

- 10

- year Peak EEC

( μg /L) Estuarine/marine

Invertebrates

LC 50 

### = 56 μg a.i./L 1

- in

- 10

- year 21

- day EEC ( μ g/L) Estuarine/marine

Invertebrates

NOAEC = 9.5 μg a.i./L Acute RQs Chronic RQs

Turf FLturf 0.55 x 14 x 9 43.7 0.8 *** 

### 42 4.4 †



### PAturf 32.9 0.6 *** 

### 32 3.4 †



### Corn IAcorn

0.25 x 7 x 4 24.3 0.4 ** 

### 23.4 2.5 †



### ILcorn 30.9 0.6 *** 

### 29.7 3.1 †



### INcorn 24.9 0.4 ** 

### 24.1 2.5 †



### KScorn 41.1 0.7 *** 

### 39.3 4.1 †



### MNcorn 29.7 0.5 *** 

### 28.6 3.0 †



### MScorn 34.2 0.6 *** 

### 33.3 3.5 †



### NCcorn 22.2 0.4 ** 

### 21.3 2.2 †



### NEcorn 33.2 0.6 *** 

### 31.7 3.3 †



### OHcorn 28.9 0.5 *** 

### 27.9 2.9 †



### PAcorn 25.3 0.5 *** 

### 24.8 2.6 †



### Peanuts NCpeanut 0.4 x 10 x 2 17.4 0.3 ** 

### 16.6 1.7 †



### Wheat NDwheat 0.2 x 14 x 2 10 0.2 ** 

### 9.69 1.0 †



### Potato IDpotato 0.33 x 7 x 6 32.5 0.6 *** 

### 32.1 3.4 †



### MEpotato 52.6 0.9 *** 

### 51.3 5.4 †



### Almond CAalmond 0.25 x 7 x 6 21.5 0.4 ** 

### 20.6 2.2 †



### Sugarcane FLsugarcane 0.25 x 14 x 4 29.7 0.5 *** 

### 28.6 3.0 †



### LAsugarcane 31.5 0.6 *** 

### 30.5 3.2 †



### Lettuce CAlettuce 0.25 x 14 x 6 (1 CC / year)

0.25 x 14 x 18 82. 3 (3 CC/yr) 1.5 *** 

### 80.9 (3 CC/yr) 8.5 †



### 33.5 (1 CC/yr) 0.6 *** 

### 32.5 (1 CC/yr) 3.4 †

### 59 Table IV. 10 . Risk Quotients for Estuarine/marine Invertebrates via Foliar Sprays

Crop Scenario Use Pattern (lb a.i./A x days

interval x no. of

applications) 1

- in

- 10

- year Peak EEC

( μg /L) Estuarine/marine

Invertebrates

LC 50 

### = 56 μg a.i./L 1

- in

- 10

- year 21

- day EEC ( μ g/L) Estuarine/marine

Invertebrates

NOAEC = 9.5 μg a.i./L Acute RQs Chronic RQs

Pepper FLpepper ( 3 CC / year) 150 (3 CC/yr) 2.7 *** 

### 152 (3 CC/yr) 16.0 †



### 50.6 (1 CC/yr) 0.9 *** 

### 49.4 (1 CC/yr) 5.2 †



### Bean ORbean 111 (3 CC/yr) 2.0 *** 

### 111 (3 CC/yr) 11.7 †



### Melon NJmelon 96.7 (3 CC/yr) 1.7 *** 

### 95.1 (3 CC/yr) 10.0 †



### Asparagus MIasparagus 60 (3 CC/yr) 1.1 *** 

### 58.2 (3 CC/yr) 6.1 †



### Tomato PAtomato 96.5 (3 CC/yr) 1.7 *** 

### 95.4 (3 CC/yr) 10.0 †

** 

### RQ exceeds the acute risk to listed species LOC of 0.05 and the acute restricted use LOC of 0.1.

*** 

### RQ exceeds the acute risk to listed species LOC of 0.05, the acute restricted use LOC of 0.1, and the acute risk to listed species LOC of 0.5.

† 

### RQ exceeds chronic risk LOC of 1.0.

For Dynasty and Cru i ser Max seed treatments on rice, RQ values exceed the acute ri s k to listed species LOC; Dynast y seed treatment on rice also exceeds the acute restricted use LOC ( Table IV.11 ). None of the seed treatment uses modeled exceed the chronic risk

LOC.

### 60 Estuarine/marine Invertebrates

– Seed Treatment

Table IV.11. Risk Quotients for Estuarine/marine Invertebrates via Seed Treatment

Crop Application Rate (lb a.i./A) GENEEC

Peak EEC

(μg/L) Estuarine/marine

Invertebrates

LC 50 

### = 56 μg a.i./L GENEEC

21

- day EEC ( μ g/L) Estuarine/marine

Invertebrates

NOAEC =

9.5 μg a.i./L Acute RQs Chronic RQs

DYNASTY

Brassica crops 0.00062 0.0078 <0.01 0.0075 <0.1

Sorghum 0.00175 0.022 <0.01 0.021 <0.1

Rice 1 0.012 6.1 0.1 ** 6.1 0.6

Soybeans 0.00478 0.06 <0.01 0.058 <0.1

Sunflower 0.009 0.113 <0.01 0.109 <0.1

DYNASTY CST

Cotton 0.0032 0.04 <0.01 0.039 <0.1

DYNASTY EXTREME

Cotton 0.0033 0.04 <0.01 0.039 <0.1

ADAGE DELUXE

Soybean 0.0015 0.019 <0.01 0.018 <0.1

ADAGE PREMIER

Soybean 0.0015 0.019 <0.01 0.018 <0.1

AVICTA CORN 250

Field corn 0.023 0.288 <0.01 0.279 <0.1

Popcorn 0.038 0.476 <0.01 0.462 <0.1

Sweet corn 0.046 0.576 0.01 0.559 <0.1

AVICTA CORN 500

Field corn 0.022 0.288 <0.01 0.279 <0.1

Popcorn 0.037 0.476 <0.01 0.462 <0.1

Sweet corn 0.045 0.576 0.01 0.559 <0.1

### 61 Table IV.11. Risk Quotients for Estuarine/marine Invertebrates via Seed Treatment

Crop Application Rate (lb a.i./A) GENEEC

Peak EEC

(μg/L) Estuarine/marine

Invertebrates

LC 50 

### = 56 μg a.i./L GENEEC

21

- day EEC ( μ g/L) Estuarine/marine

Invertebrates

NOAEC =

9.5 μg a.i./L Acute RQs Chronic RQs

CRUISER EXTREME

Field corn 0.0024 0.003 <0.01 0.0029 <0.1

Popcorn 0.0004 0.005 <0.01 0.0049 <0.1

Sweet corn 0.0005 0.0063 <0.01 0.0061 <0.1

CRUISER MAXX RICE

Rice 1 0.0078 4.0 0.07 * 4.0 0.4

FOUR WAY VAP

Crop group 7 0.0029 0.036 <0.01 0.035 <0.1

Crop group 6 0.0077 0.096 <0.01 0.094 <0.1

Soybean 0.0029 0.036 <0.01 0.035 <0.1

MAXIM QUATTRO

Field corn 0.0003 0.0038 <0.01 0.0036 <0.1

Popcorn 0.0006 0.0075 <0.01 0.0073 <0.1

Sweet corn 0.0006 0.0075 <0.01 0.0073 <0.1

QUARTET

Cotton 0.0026 0.033 <0.01 0.032 <0.1

TRIO CST

Cotton 0.0029 0.036 <0.01 0.035 <0.1

* RQ meets or exceeds the acute risk to listed species LOC of 0.05

** RQ exceeds the acute risk to listed species LOC of 0.05 and the acute restricted use LOC of 0.1.

1 Based on Tier I Rice model

.

### 62 IV .1. 2. Aquatic Plants

RQs for non

- listed and listed aquatic plants exposed to azoxystrobin via runoff and spray drift

from foliar treatments are calculated in Tables IV.12 and IV.14 ; the RQs for aquatic plants exposed to runoff from azoxystrobin

- treated seeds are tabulated in Tables IV.13 and IV.15

. For aquatic vascular plants, RQ values are below the LOC of 1.0 for both non

- listed and listed species from runoff for both foliar ( Tab le IV.12 ) and seed treatments ( Table IV.13 ). The potential risks to aquatic plants are discussed further in Section IV .2

.

Aquatic Vascular Plants

- Foliar Spray

Table IV.12 . Risk Quotients for Aquatic Vascular Plants via Foliar Sprays

Crop Scenario Use Pattern (lb a.i./A x days

interval x no. of

applications) 1

- in

- 10

-
year Peak

EEC (μ g/L) Non

- listed Aquatic

Vascular Plants

EC 50 = 3400

μg a.i./L Listed Aquatic

Vascular Plants NOAEC = 800 μg

a.i./L

Non

- listed RQ Listed RQs

Pepper FLpepper 0.25 x 14 x 18 ( 3 CC / year) 150 <0.1 0.2



### Aquatic Vascular Plants

– Seed Treatment

Table IV.1 3 . Risk Quotients for Aquatic Vascular Plants via Seed Treatment

Crop Application

Rate (lb a.i./A) Rice Model

Peak EEC

(μg/L) Non

- listed Aquatic

Vascular Plants

EC 50 = 3400

μg a.i./L Listed Aquatic Vascular

Plants NOAEC = 800 μg a.i./L

Non

- listed RQ Listed RQs

DYNASTY

Rice 1 0.012 6.1 <0.1 <0.1

1 Based on Tier I Rice model.



### Aquatic Non

- Vascular Plants

- Foliar Spray

For foliar applications, except for uses on peanuts and wheat, all of the RQ values exceed the LOC for risk to listed species ( Table IV.14 ). For uses on potatoes, lettuce, beans, melons, asparagus and tomatoes, RQs exceed the acute risk to non

- listed species LOCs. Run

- off from seed treatme nts resulted in RQ values below aquatic plant LOCs ( Table IV.15 ).

Table IV.14 . Risk Quotients for Aquatic Non

- vascular Plants via Foliar Sprays

Crop Scenario Use Pattern (lb a.i./A x days

interval x no. of

applications) 1

- in

- 10

-
year Peak EEC

(μ g/L) Non

- listed Aquatic

Nonvascular

Plants

EC 50 = 49 μg a.i./L Listed Aquatic

Nonvascular

Plants NOAEC = 20 μg

a.i./L

Non

- listed RQ Listed RQs

Turf FLturf 0.55 x 14 x 9 43.7 0.9 2.2

PAturf 32.9 0.7 1.6

Corn IAcorn 0.25 x 7 x 4 24.3 0.5 1.2

### 63 Table IV.14 . Risk Quotients for Aquatic Non

- vascular Plants via Foliar Sprays

Crop Scenario Use Pattern (lb a.i./A x days

interval x no. of

applications) 1

- in

- 10

-
year Peak EEC

(μ g/L) Non

- listed Aquatic

Nonvascular

Plants

EC 50 = 49 μg a.i./L Listed Aquatic

Nonvascular

Plants NOAEC = 20 μg

a.i./L

Non

- listed RQ Listed RQs

ILcorn 30.9 0.6 1.5

INcorn 24.9 0.5 1.2

KScorn 41.1 0.8 2.1

MNcorn 29.7 0.6 1.5

MScorn 34.2 0.7 1.7

NCcorn 22.2 0.5 1.1

NEcorn 33.2 0.7 1.7

OHcorn 28.9 0.6 1.4

PAcorn 25.3 0.5 1.3

Peanuts NCpeanut 0.4 x 10 x 2 17.4 0.4 0.9

Wheat NDwheat 0.2 x 14 x 2 10 0.2 0.5

Potato IDpotato 0.33 x 7 x 6 32.5 0.7 1.6

MEpotato 52.6 1.1 2.6

Almond CAalmond 0.25 x 7 x 6 21.5 0.4 1.1

Sugarcane FLsugarcane 0.25 x 14 x 4 29.7 0.6 1.5

LAsugarcane 31.5 0.6 1.6

Lettuce CAlettuce

0.25 x 14 x 6 (1 CC / year)

0.25 x 14 x 18 (3 CC / year) 82.3 (3 CC/yr) 1.7 4.1

33.5 (1 CC/yr) 0.7 1.7

Pepper FLpepper 150 (3 CC/yr) 3.1 7.5

50.6 (1 CC/yr) 1.0 2.5

Bean ORbean 111 (3 CC/yr) 2.3 5.6

Melon NJmelon 96.7 (3 CC/yr) 2.0 4.8

Asparagus MIasparagus 60 (3 CC/yr) 1.2 3.0

Tomato PAtomato 96.5 (3 CC/yr) 2.0 4.8

A bold cell indicates that the RQ meets or exceeds the plant LOCs of 1.0 for both listed and non

- listed plants, respectively

.

### 64 Aquatic Nonvascular Plants

– Seed Treatment

Table IV.15 . Risk Quotients for Aquatic Nonvascular Plants via Seed Treatment

Crop Application

Rate (lb a.i./A) Rice Model

Peak EEC

(μg/L) Non

- listed Aquatic

Nonvascular Plants

EC 50 = 49 μg a.i./L Listed Aquatic

Nonvascular Plants NOAEC = 20 μg a.i./L

Non

- listed RQ Listed RQs

DYNASTY

Rice 1 0.012 6.1 <0.1 <0.1

1 Based on Tier I Rice model

.



### IV.1.2 Terrestrial Animals

Brief Description of T

- REX Modeling for Birds and Mammals

F oliar spray f ormulas presented below in Table IV.1 6 are used to calculate dose

- based a nd dietary based risk quotients. Seed treatment f ormulas in Table IV.1 7 are used to calculate dose

based and available pesticide acute risk quotients . For seed treatment chronic risk quotients, the

m aximum seed application rate for b irds and the dose

- based route for mammals were used

. The potential risks to terrestrial animals are discussed further in Section IV.2

.

Table IV.16 . F oliar Spray F ormulas Used to Calculate Dose

- Based and Dietary

- Based Risk Quotients

Duration Dose or Dietary RQ Surrogate Organism Equation

Acute Dose

- based Birds and

mammals Acute Daily Exposure (mg/kg

- bw) / adjusted LD 50 (mg/kg

bw) 1,2
Dietary

- based Birds Kenaga EEC (mg/kg

- food item) / LC 50 (mg/kg

- diet)

Chronic Dietary

- based Birds and

mammals EEC (mg/kg

- food item) / NOAEC (mg/kg

- diet)

Dose

- based Mammals only EEC (mg/kg

- bw) / Adjusted NOAEL (mg/kg

- bw) 2

1 Adj. Bird LD 50 = Bird LD 50 (AW/TW) (a

- 1)

2 Adj. Mammal LD 50 or NOAEL = Mammal LD 50 or NOAEL (TW/AW) 0.25

### 65 Table IV.17

. Seed Treatment Formulas Used to Calculate Dose

- Based and Available Pesticide Risk Quotients

Duration Type of RQ Surrogate Organism Equation

Acute Dose

- based Birds and

mammals Daily Exposure (mg/kg

- bw /day ) / adjusted LD 50 (mg/kg

bw) 1,2

Available A.I. Birds and

mammals mg a.i./ft 2 / adjusted L D 50 (mg/kg

- bw )

Chronic Seed application

rate Birds EEC (mg/kg

- seed) / NOAEL (mg/kg

- bw/day )

Dose

- based Mammals Daily Exposure (mg/kg

- bw/day) / Adjusted NOAEL (mg/kg

- bw) 2

1 Adj. Bird LD 50 = Bird LD 50 (AW/TW) (a

- 1)

2 Adj. Mammal LD 50 or NOAEL = Mammal LD 50 or NOAEL (TW/AW) 0.25



### Risk Quotient Calculations Based on Foliar Application

Birds and mammals foraging short grass with azoxystrob in residues via the dose

- based route assumes the highest exposure of all scenarios modeled for the current uses ( Tables IV.18 (mammal, dose

- based)

, IV.23 (bird, dietary

- based)

, and IV.24 (mammal, dietary

- based) ). Thus exposure for other modeled scenarios is expected to be lower than the maximum scenario modeled

when heavier ver tebrates, use patterns with lower rates, or/and selected food items other than short grass are used. With chronic LOC exceedances observed for chronic effects to mammals from foraging short grass with the residues, other T

- REX food items in order from high est to lowest

exposure were assess ed for exceedances ( Tables IV.19 thru IV.22 for dose

- based ). The food item resulting in the lowest potential exposure (seeds for granivores) was not tabulated as no LOC

exceedances occurred. Except for mammals foraging fr uits and pods, the majority of uses resulted

in dose

- based RQ values

, which exceed the chronic risk LOC for each of the three sizes of listed

and non

- listed mammals evaluated.

Dosed

- based chronic RQs for mammals of different body weight sizes are tabula ted below in

Tables IV.18 thru IV.22

. In addition, T

- REX does not differentiate between aerial or ground applications; thus, T

- REX results are based on broadcast foliar applications.

Table IV.18 . Dose

- Based Chronic Risk Quotients for Mammal s of Different Body Weight Classes Foraging Short Grass with Azoxystrobin Residues *

Crop App Rate

in lbs a.i./A / No. of Apps / # days interval Short Grass

EEC for 15 g / 35 g / 1000 g (mg/kg

- bw) Chronic RQs (dose

- based EEC/ adjusted NOAEL)

15 g; small 35 g; medium 1000 g; large

Turf 0.55 / 9x / 14D 262/181/42 8 * 7 * 4 *

Corn 0.25 / 4x / 7D 150/104/24 5 * 4 * 2 *

Peanuts 0.4 / 2x / 10D 139/96/22 4 * 4 * 2 *

Wheat 0.2 / 2x / 14D 75/51/12 2 * 2 * 1 *

Potato 0.33 / 6x / 7D 233/161/37 7 * 6 * 3 *

Almond 0.25 / 6x / 7D 177/122/28 5 * 5 * 2 *

### 66 Table IV.18 . Dose

- Based Chronic Risk Quotients for Mammal s of Different Body Weight Classes Foraging Short Grass with Azoxystrobin Residues *

Crop App Rate

in lbs a.i./A / No. of Apps / # days interval Short Grass

EEC for 15 g / 35 g / 1000 g (mg/kg

- bw) Chronic RQs (dose

- based EEC/ adjusted NOAEL)

15 g; small 35 g; medium 1000 g; large

Sugarcane 0.2 / 4x / 14D 111/77/18 3 * 3 * 2 *

Leafy Vegetables 0.25 / 6x / 14D 117/81/19 4 * 3 * 2 *

0.25 / 18x / 14D 120/83/19 4 * 3 * 2 *

* Bold value indicates the RQ exceeds the chronic risk LOC for listed and non

- listed mammals

.



### Table IV.19. Dose

- Based Chronic Risk Quotients for Mammals of Different Body Weight Classes Foraging Broadleaf Plants with Azoxystrobin Residues*

Crop App Rate

in lbs a.i./A / No. of Apps / # days interval Broadleaf plant EEC for 15 g / 35 g / 1000 g (mg/kg

- bw) Chronic RQs (dose

- based EEC/ adjusted NOAEL)

15 g;

small 35 g;

medium 1000 g; large

Turf 0.55 / 9x / 14D 147/102/24 4 * 4 * 2 *

Corn 0.25 / 4x / 7D 84/58/14 3 * 2 * 1 *

Peanuts 0.4 / 2x / 10D 78/54/13 2 * 2 * 1 *

Wheat 0.2 / 2x / 14D 42/29/7 1 * 1 * 0.6

Potato 0.33 / 6x / 7D 131/91/21 4 * 3 * 2 *

Almond 0.25 / 6x / 7D 99/69/16 3 * 3 * 1 *

Sugarcane 0.2 / 4x / 14D 62/43/10 2 * 2 * 0. 9

Leafy Vegetables 0.25 / 6x / 14D 66/46/11 2 * 2 * 0.9

0.25 / 18x / 14D 67/46/11 2 * 2 * 0.9

* Bold value indicates the RQ exceeds the chronic risk LOC of 1.0 for listed and non

- listed mammals.



### Table IV.20 . Dose

- Based Chronic Risk Quotients for Mammals of Different Body Weight Classes Foraging Tall Grass with Azoxystrobin Residues*

Crop App Rate

in lbs a.i./A / No. of Apps / # days interval Tall Grass EEC for 15 g / 35 g / 1000 g (mg/kg

bw) Chronic RQs (dose

- based EEC/ adjusted NOAEL)

15 g;

small 35 g;

medium 1000 g; large

Turf 0.55 / 9x / 14D 120/83/19 4 * 3 * 2 *

Corn 0.25 / 4x / 7D 69/47/11 2 * 2 * 0.95

Peanuts 0.4 / 2x / 10D 64/44/10 2 * 2 * 0.9

Wheat 0.2 / 2x / 14D 34/24/5 1 * 0.9 0.5

Potato 0.33 / 6x / 7D 107/74/17 3 * 3 * 1 *

Almond 0.25 / 6x / 7D 81/56/13 2 * 2 * 1 *

Sugarcane 0.2 / 4x / 14D 51/35/8 2 * 1 * 0. 7

Leafy Vegetables 0.25 / 6x / 14D 54/37/9 2 * 1 * 0.8

0.25 / 18x / 14D 55/38/9 2 * 1 * 0.8

### 67 Table IV.20 . Dose

- Based Chronic Risk Quotients for Mammals of Different Body Weight Classes Foraging Tall Grass with Azoxystrobin Residues*

Crop App Rate

in lbs a.i./A / No. of Apps / # days interval Tall Grass EEC for 15 g / 35 g / 1000 g (mg/kg

bw) Chronic RQs (dose

- based EEC/ adjusted NOAEL)

15 g;

small 35 g;

medium 1000 g; large

* Bold value indicates the RQ exceeds the chronic risk LOC of 1.0 for listed and non

- listed mammals.



### Table IV.21 . Dose

- Based Chronic Risk Quotients for Mammals of Different Body Weight Classes Foraging Arthropods with Azoxystrobin Residues*

Crop App Rate

in lbs a.i./A / No. of Apps / # days interval Arthropod EEC for 15 g / 35 g / 1000 g (mg/kg

bw) Chronic RQs (dose

- based EEC/ adjusted NOAEL)

15 g; small 35 g;

medium 1000 g; large

Turf 0.55 / 9x / 14D 103/71/16 3 * 3 * 1 *

Corn 0.25 / 4x / 7D 59/41/9 2 * 2 * 0.8

Peanuts 0.4 / 2x / 10D 55/38/9 2 * 1 * 0. 8

Wheat 0.2 / 2x / 14D 29/20/5 0.9 0.8 0.4

Potato 0.33 / 6x / 7D 91/63/15 3 * 2 * 1 *

Almond 0.25 / 6x / 7D 69/48/11 2 * 2 * 0.96

Sugarcane 0.2 / 4x / 14D 43/30/7 1 * 1 * 0.6

Leafy Vegetables 0.25 / 6x / 14D 46/32/7 1 * 1 * 0.6

0.25 / 18x / 14D 47/32/8 1 * 1 * 0.7

* Bold value indicates the RQ exceeds the chronic risk LOC of 1.0 for listed and non

- listed mammals.



### Table IV.22 . Dose

- Based Chronic Risk Quotients for Mammals of Different Body Weight Classes Foraging Fruits and Pods with Azoxystrobin Residues*

Crop App Rate

in lbs a.i./A / No. of Apps / # days interval Fruits and Pods EEC for 15 g / 35 g / 1000 g (mg/kg

- bw) Chronic RQs (dose

- based EEC/ adjusted NOAEL)

15 g;

small 35 g;

medium 1000 g; large

Turf 0.55 / 9x / 14D 16/11/3 0.5 0.4 0.2

Corn 0.25 / 4x / 7D 9/6/2 0.3 0.2 0.1

Peanuts 0.4 / 2x / 10D 9/6/1 0.3 0. 2 0.1

Wheat 0.2 / 2x / 14D 5/3/1 0.1 0.1 <0.1

Potato 0.33 / 6x / 7D 15/10/2 0. 4 0. 4 0. 2

Almond 0.25 / 6x / 7D 11/8/2 0.3 0. 3 0.2

Sugarcane 0.2 / 4x / 14D 7/5/1 0.2 0.2 0.1

Leafy Vegetables 0.25 / 6x / 14D 7/5/1 0.2 0.2 0.1

0.25 / 18x / 14D 7/5/1 0.2 0.2 0.1



### T

- REX results of dietary

- based chronic RQs for birds are tabulated below in Table IV.23 . No

chronic risk LOC exceedances were observed for birds foraging on short grass using the maximum

### 68 exposure scenario; thus, LOC exceedances for other selected feed items and exposure scenarios with lower EECs are not expected.

Table IV.23 . Dietary

- Based Chronic Risk Quotients for Birds Foraging Short Grass with Azoxystrobin Residues

Crop App Rate in lbs a.i./A / No. of Apps / # days interval Short Grass EEC (mg/kg

- bw) Chronic RQs (dietary

based EEC/ NOAEC)

Turf 0.55 / 9x / 14D 275 0.2

Corn 0.25 / 4x / 7D 179 0.1

Peanuts 0.4 / 2x / 10D 146 0.1

Wheat 0.2 / 2x / 14D 78 < 0.1

Potato 0.33 / 6x / 7D 245 0.2

Almond 0.25 / 6x / 7D 185 0.2

Sugarcane 0.2 / 4x / 14D 116 0.1

Leafy Vegetables 0.25 / 6x / 14D 123 0.1

0.25 / 18x / 14D 125 0.1



### T

- REX results of dietary

- based chronic RQs for mammals are tabulated below in Table IV.24

. There were no chronic risk LOC exceedances for mammals fora ging on short grass in all current use sites; thus, LOC exceedances for other selected feed items and exposure scenarios with lower EECs are not expected ( Table IV.24 ).

Table IV.24 . Dietary

- Based Chronic Risk Quotients for Mammals Foraging Short

Grass wit h Azoxystrobin Residues

Crop App. Rate in lbs a.i./A / No. of Apps / # days interval Short grass EEC (mg/kg

bw) Chronic RQs (dietary

- based EEC / NOAEC)

Turf 0.55 / 9x / 14D 275 0.9

Corn 0.25 / 4x / 7D 179 0. 5

Peanuts 0.4 / 2x / 10D 146 0. 5

Wheat 0.2 / 2x / 14D 78 0.3

Potato 0.33 / 6x / 7D 245 0.8

Almond 0.25 / 6x / 7D 185 0. 6

Sugarcane 0.2 / 4x / 14D 116 0. 4

Leafy Vegetables 0.25 / 6x / 14D 123 0.4

0.25 / 18x / 14D 125 0.4



### Risk Quotient Calc ulations Based on Seed Treatment

### 69 T

- REX results of chronic RQs for birds and mammals foraging azoxystrobin

- treated seed s are tabulated below in Tables IV.2 5 and IV.2 6 , respectively . Chronic risk LOC exceedances were

observed for birds in sunflower and in sweet corn and popcorn use sites and for mammals of all weights in field corn, popcorn, and sweet corn use sites, for small ( 15 g ) and medium ( 35 g) mammals in head/stem Brassica crops and sorghum use sites , and for 15

- g mammals in cotton

use sites

.

Table IV.25 . Chronic Risk Quotients for Birds Exposed via Seed Treatment*

Crop App Rate

in fl. oz./CWT Seed Application

Rate (mg/kg

- seed) Chronic RQs (mg/kg

- seed / NOAEL)

DYNASTY Brassica crops 3.75 234.28 0.2

Rice 1.53 95.59 0.08

Sorghum 3.05 190.55 0.16

Soybeans 0.459 28.68 0.02

Sunflower 37.5 2342.81 1.95 *

DYNASTY CST

Cotton 3.95 170.69 0.14

DYNASTY EXTREME

Cotton 3.0 162.63 0.14

ADAGE DELUXE

Soybean 4.29 8.93 0.01

ADAGE PREMIER

Soybean 4.23 8.81 0.01

AVICTA CORN 250

Field corn 11.61 778.22 0.65

Popcorn 25.8 1729.39 1.44 *

Sweet corn 20.65 1384.18 1.15 *

AVICTA CORN 500

Field corn 11.4 756.7 0.63

Popcorn 25.2 1672.77 1.39 *

Sweet corn 20.2 1340.87 1.12 *

CRUISER EXTREME

Field corn 2.51 8.17 0.01

Popcorn 5.58 18.16 0.02

Sweet corn 4.46 14.5 0.01

CRUISER MAXX RICE

### 70 Table IV.25 . Chronic Risk Quotients for Birds Exposed via Seed Treatment*

Crop App Rate

in fl. oz./CWT Seed Application

Rate (mg/kg

- seed) Chronic RQs (mg/kg

- seed / NOAEL)

Rice 7 60.13 0.05

FOUR WAY VAP

Crop group 7 3 17.57 0.01

Crop group 6 3 17.57 0.01

Soybean 3 17.57 0.01

MAXIUM QUATTRO

Field corn 1.18 10.21 0.01

Popcorn 3.07 20.57 0.02

Sweet corn 2.05 17.74 0.01

QUARTET

Cotton 4 136.4 0.11

TRIO CST

Cotton 3.5 151.24 0.13

* Bold value indicates the RQ exceeds the chronic risk LOC of 1.0 for listed and non

- listed species.



### Table IV. 26 . Chronic Risk Quotients for Mammals of Body Weight Classes Exposed

via Seed Treatment *

Crop App Rate

in fl. oz./CWT Seed EEC for 15 g / 35 g / 1000 g

(mg/kg

- bw) Chronic RQs (dose

- based EEC/ adjusted NOAEL)

15 g;

small 35 g;

medium 1000 g; large

DYNASTY

Head/Stem Brassica crops 3.75 50/34/8 1.5 * 1.3 * 0.7

Rice 1.53 20/14/3 0.6 0.5 0.3

Sorghum 3.05 41/28/7 1.2 * 1.1 * 0.6

Soybean 0.459 6/4/1 0.18 0.16 0.08

Sunflower 37.5 496/343/80 15 * 13 * 7 *

DYNASTY CST

Cotton 3.95 36/25/6 1.1 * 0.9 0.5

DYNASTY EXTREME

Cotton 3 34/24/6 1.05 * 0.9 0.5

ADAGE DELUXE

Soybean 4.29 2/1/0.3 0.06 0.05 0.03

ADAGE PREMIER

### 71 Table IV. 26 . Chronic Risk Quotients for Mammals of Body Weight Classes Exposed

via Seed Treatment *

Crop App Rate

in fl. oz./CWT Seed EEC for 15 g / 35 g / 1000 g

(mg/kg

- bw) Chronic RQs (dose

- based EEC/ adjusted NOAEL)

15 g;

small 35 g;

medium 1000 g; large

Soybean 4.23 2/1/0.3 0.06 0.05 0.03

AVICTA CORN 250

Field corn 11.61 165/114/26 5 * 4.3 * 2.3 *

Popcorn 25.8 366/253/59 11 * 9.5 * 5.1 *

Sweet corn 20.65 293/203/47 8.9 * 7.6 * 4.1 *

AVICTA CORN 500

Field corn 11.4 160/111/27 4.9 * 4.2 * 2.2 *

Popcorn 25.2 354/245/57 10.8 * 9.2 * 4.9 *

Sweet corn 20.2 284/196/46 8.6 * 7.4 * 4.0 *

CRUISER EXTREME

Field corn 2.51 2/1/0.3 0.05 0.04 0.02

Popcorn 5.58 4/3/0.6 0.12 0.1 0.05

Sweet corn 4.46 3/2/0.5 0.09 0.08 0.04

CRUISER MAXX RICE

Rice 7 13/9/2 0.4 0.3 0.2

FOUR WAY VAP

Crop group 7 3 4/3/0.6 0.11 0.1 0.05

Crop group 6 3 4/3/0.6 0.11 0.1 0.05

Soybean 3 4/3/0.6 0.11 0.1 0.05

MAXIM QUATTRO

Field corn 1.18 2/2/0.4 0.07 0.06 0.03

Popcorn 3.07 6/4/0.9 0.17 0.15 0.08

Sweet corn 2.05 4/3/0.6 0.11 0.1 0.05

QUARTET

Cotton 4 29/20/5 0.88 0.75 0.4

TRIO CST

Cotton 3.5 32/22/5 0.97 0.83 0.45

* Bold value indicates the RQ exceeds the chronic risk LOC of 1.0 for listed and non

- listed species.



### IV.1. 3. Terrestrial Plants in Dry and Semi

- aquatic Environments

TerrPLANT modeling yield s no LOC exceedances at the maximum exposure scenario using the highest single application rate applied via air, ground, or seeds to terrestrial plants inhabiting dry

and semi

- aquatic areas adjacent to a treated site e xposed to a combination of surface water runoff

### 72 and spray drift; thus, all other exposure scenarios with lower application rates are not expected to exceed the plant LOC as well ( Table IV. 27 )

.

For spray drift alone usin g AgDRIFT, the RQ exceeded the LOC for risk to listed terrestrial plants exposed to off

- site drift from ground applications at the maximum application rate (turf uses). The RQs did not exceed the LOC for risk to listed plants inhabiting areas at a distance of 10 feet or more from the edge o f a treated turf site; the RQs also did not exceeded the LOC for all other uses receiving a downwind drift of azoxystrobin residues ( Table IV. 2 8 ).

Unlike T

- REX, TerrPLANT and AgDRIFT differentiate between aerial and ground applications

but turf use label s for azoxystrobin do not allow aerial applications, only EECs from ground applications were modeled for turf uses. All other uses were modeled for aerial and ground applications ; however , because there were no LOC exceedances in previous risk assessments, only the maximum application scenario and aerial applications (the method resulting in the highest exposure potential) were calculated for any change in its risk conclusion for terrestrial plants

. The potential risks to terrestrial plants are discussed further in Section IV.2

.

Table IV.2 7 . Risk Quotients for Terrestrial Plants 1



### — Spray Drift and Run

- off

Crop App Rate

in lbs a.i./A (method of app) EEC (lb a.i./A) RQs



### Dry

Areas Semi

aquatic

Areas Dry Area Semi

- aquatic Area

Non

- listed RQ Listed RQs Non

- listed RQ Listed RQs

Turf 0.55 (ground) 0.011 0.0605 <0.1 <0.1 <0.1 0. 1 2

All other Uses 0.4 (aerial) 0.024 0.06 <0.1 <0.1 <0.1 0.12

Rice 0.012 (seed trt) 0.00008 0.0008 <0.1 <0.1 <0.1 <0.1

trt

- treatment

1 Based on most sensitive terrestrial plant tested

– carrots; the EC 25 and NOAEC value s were 0.59 and 0.5 lb a.i./A respectively.



### Table IV.2 8

. AgDRIFT Assessment for Spray Drift Only

-- Non

- target Listed and Non

listed Terrestrial Plant Species Inhabiting Areas Adjacent to a Treated Site a
No. of Applications and Application Rate (lb a.i/.A) Distance from Edge of Field EEC (lb a.i./A) Non

- listed Plant RQ Listed Plant RQ Spray

Method

Terrestrial plants inhabiting dry areas

1 @ 0.55 0 feet 0.55 0.9 1. 1 * Ground 1 0 feet 0.1 0.2 0.2

1 @ 0.4 0 feet 0.2 0.3 0.4 Aerial

a Based on carrot EC 25 and NOAEC value of 0.59 and 0. 5 lb a.i./A

, respectively.

*Value in bold indicates the LOC for risk to plants is exceeded.



## IV.2. Risk Description

The risk hypothesis in the Preliminary Problem Formulation written in support of the Registration

Review s tated that the use of azoxystrobin as a fungicide for terrestrial crop sites as a foliar spray with aerial and ground

- boom equipment or through seed t reatment has the potential to adversely affect survival, reproduction, and/or growth of non

- target aquatic and terrestrial animals and

### 73 plants. Based on the available ecotoxicity data and predicted environmental exposures, the hypothesis is confirmed for p otential adverse effects to fish (and aquatic

- phase amphibians )

, aquatic invertebrates, birds (and terrestrial

- phase amphibians and reptiles), mammals , terrestrial

dicot plants, and aquatic non

- vascular plants based on the current uses for azoxystrobin and additionally the presumption of risk to terrestrial invertebrates in the absence of data . Results of

the risk estimation indicate terrestrial monocot plants and aquatic vascular plants (duckweed) were

not likely to be adversely affected. The following sec tions discuss the potential risks of azoxystrobin to these taxonomic groups.

IV.2.1. Risks to Aquatic Organisms and Plants

In the problem formulation, the conceptual model states spray drift and surface runoff/leaching to adjacent bodies of water fro m foliar sprays and surface runoff to adjacent bodies of water from

seed treatments were predicted as the most l ikely sources of exposure of az oxystrobin to non

- listed aquatic organisms and plants. Risks to aquatic species ( i.e

. , fish, invertebrates, and plants) were assessed based on modeled EECs and available toxicity data. The aquatic EECs were estimated using SWCC ( Table III. 4 ) for foliar appl ications and GENEEC/Rice for seed treatment ( Table

III. 5 )

. The RQ calculations for e ach taxonomic group are shown in Tables IV.4 thru IV .11 in

Section IV.1

. Detail ed d iscussions of the potential risks and the magnitude to fish, aquatic invertebrates, aquatic plants, and aquatic nonvascular plants can be found below in the subsequent

sections.

In summary, AgDRIFT was used to assess risks to non

- listed fish, aquatic invertebrates, aquatic plants, and aquatic nonvascular plants that inhabit water bodies adjacent or in close proximity to azoxystrobin

- treated sites and to assess the distance from the edge of a n application site at which RQs f or spray drift fall below the acute risk to non

- listed species LOC of 0.5 ( Table IV. 29 ). The RQs were calculated by comparing the amount of deposition (“EEC”) at a specific distance from the edge of the field and the respective toxicity endpoints for each taxon . As the deposition distance increases, the magnitude of exposure s to species outside a treated site decreases

.

This spray drift exposure analysis indicates that when aerial

- b ased application methods are used ( the method resulting in the highest exposure potential ) at the maximum label rate of 0.4 lb a.i./A

, exposure falls below the LOC for non

- listed species beyond the edge of a treated field ; thus, risks

are not of concern

. With ground

- based applications at the maximum label rate of 0.55 lb a.i./A, there were no LOC exceedances from spr ay drift exposures for non

- listed aquatic fauna and flora inhabiting waterbodies adjacent to the edge of a treated site. Therefore , adverse ef fects to non

listed aquatic species in waterbodies adjacent to treated site exposed to spray drift alo ne are not likely. This suggests surface water runoff with azoxystrobin residues contributes more to the risk potential than when exposed to off

- site spra y drift alone.

Table IV. 29

. Ag D RIFT Assessment for Non

- Listed Aquatic Fauna and Flora Species

No. of Applications

and Application

Rate (lb a.i./A) Distance from Edge of Field EEC in pond (μg a.i./L) RQ (EEC/ LC 50

or EC 50 ) RQ (EEC/ NOAEC) Spray

Method

Freshwater fish inhabiting pond a

### 74 1 @ 0.55 0 feet 1.9 <0.01 <0.1 Ground

1 @ 0.4 0 feet 2.8 <0.01 <0.1 Aerial Freshwater Invertebrates inhabiting pond b

1 @ 0.55 0 feet 1.9 <0.01 <0.1 Ground

1 @ 0.4 0 feet 2.8 0.01 <0.1 Aerial Estuarine/marine fish inhabiting pond c

1 @ 0.55 0 feet 1.9 <0.01 <0.1 Ground

1 @ 0.4 0 feet 2.8 < 0.01 <0.1 Aerial Estuarine/marine invertebrates inhabiting pond d

1 @ 0.55 0 feet 1.9 0.03 0.2 Ground

1 @ 0.4 0 feet 2.8 0.05 0.3 Aerial Aquatic vascular plants inhabiting pond e

1 @ 0.55 0 feet 1.9 <0. 1 <0.1 Ground

1 @ 0.4 0 feet 2.8 <0. 1 <0.1 Aerial Aquatic non

- vascular plants inhabiting pond f

1 @ 0.55 0 feet 1.9 <0. 1 <0.1 Ground

1 @ 0.4 0 feet 2.8 <0. 1 0.1 Aerial

a Based on trout LC 50 of 470 μg a.i ./L and fathead minnow NOAEC of 147 μg a.i./L

. b Based on a daphnid EC 50 of 260 μg a.i./L and NOAEC of 44 μg a.i./L.

c Based on sheepshead minnow LC 50 of 670 μg a.i./L and ACR

- adjusted NOAEC of 21 0 μg a.i./L

. d Based on mysid shrimp LC 50 of 56 μg a.i./L an d NOAEC of 9.5 μg a.i./L

.

e Based on duckweed EC 50 of 3400 μ g a.i./L and NOAEC of 800 μ g a.i./L.

f Based on marine diatom EC 50 and NOAEC of 49 and 20 μ g a.i./L, respectively.



## Risk to Fish

IV.2.1.1. Risk to Fish Exposed to Foliar Sprays of Azoxystrobin

Available acute toxicity data indicates that azoxystrobin is highly toxic to freshwater and estuarine/marine fish on an acute basis. The most sensitive endpoint derived from the available studies for freshwater species ( rainbow trout ) and the sheepshead minnow study for estuarine/marine species were compared to several SWCC for fish inhabiting water bodies adjacent to crops treated with azoxystrobin . A cute RQs (RQ range: 0.05

– 0.32 based on aerial application for turf and ground appl ication for all other current uses )) for freshwater species of the exposure scenarios representative of the current uses modeled except for wheat and peanuts all

exceeded the acute risk to listed species and restricted use LOCs of 0.05 and 0.1, respectivel y, following foliar applications. The RQ s for wheat and peanuts are 0.0 2 and 0.0 4 , respectively,

which are below the acute risk to listed species LOC of 0.05

. None of the RQ values for fish

exceeded the acute risk to non

- listed species LOC of 0.5.

T he fre shwater fish acute RQs exceed the a cute r estricted u se LOC of 0.1 and acute risk to listed

s pecies LOC of 0.05 following azoxystrobin applications to leafy vegetables and potatoes and

exceed the a cute risk to l isted s pecies LOC following foliar applications on corn, almond, sugarcane, and turf

. E stuarine/marine ha ve RQ values ( LOC exceedances ) similar to the freshwater species; however, acute RQs do not exceed the a cute restricted use LOC for use on potatoes.

A zoxystrobin was highly toxic to rainbow trout and moderately toxic to the bluegill sunfish with

LC 50 

### values rang ing from 470 to 1 10 0 μg a.i./L. To assess the extent of freshwater species affected when exposed to azoxystrobin , a comparison of the least sensitive species ( sunfish LC 50 

### of 1100

### 75 μg a.i./L) and the highest SWCC EEC using the FL pepper scenario after three application cycles

per year ( 150 μg a.i./L), the RQ is 0. 14 and exceeds the acute risk to listed species LOC of 0.05. Thus it is anticipated that freshwater species would be adverse ly a ffected when exposed to azoxystrobin as a result of foliar sprays ; however, more data on freshwater fish species are needed to determine the distribution of fish sensitivities to azoxystrobin . With the acute estuarine/marine

fish toxici ty data limited to a single species , the range of estuarine/marine species adversely

affected to azoxystrobin applications could not be assessed.

T he chronic NOAEC for freshwater fish is 147 μg a.i./L based on reductions of growth. The

NOAEC for estuarine/marine fish is 21 0 μg a.i./L is based on an ACR

- derived value calculated using rainbow trout acute and fathead minnow chronic data . Chronic RQs for both freshwater and

estuarine/marine fish generally resulted in no exceedance of the c hronic r isk LOC with the exception of freshwater fish for use of azoxystrobin on pepper s after three crop cycles per year for

which the chronic RQ of 1.0 is at the chronic risk LOC of 1.0

.

Risk quotients for freshwater fish indicate that aquatic

- phase amphibians are also anticipated to be subject to adverse effects from acute exposures to the TGAI as a result of runoff and spray drift to adjacent water bodies following azoxystrobin foliar tr eatments but not following seed treatments

. Of all the exposure scenarios modeled, t he c hronic r isk LOC was only exceeded for freshwater

fish inhabiting water bodies adjacent to peppers after a total of three crop cycles per year ; thus, aquatic

- phase amphibians a re also anticipated to be at risk when chronically exposed to azoxystrobin applied in pepper fields throughout the year

. However, none of the other current uses

exceed the chronic risk LOC including use on pepper where th ere is a single crop cycle per year

.

IV.2.1.2. Risks to Fish Exposed to Azoxystrobin

- treated S eed s

The freshwater and estuarine/marine acute and chronic endpoints were compared to several exposure scenarios using GENEEC and Rice models for fish inhabiti ng water adjacent to use sites

where azoxystrobin

- treated seed s are planted . Acute and chronic RQs ( acute RQs < 0.01 ; chronic RQs <0.1 ) for azoxystrobin

- treated seed uses a re below the acute and chronic risk LOCs of 0.05 and 1.0, respectively.

IV.2.1.3. Formulated Product, Degradate , Non

- Guideline Studies, Etc

.

Acute RQs for freshwater fish exposed to the formulated product and degradate are not calculated. Toxicity of a co

- formulated product (containing azoxystrobin and chlorothalonil) to the rainbow trout indicates the product is more toxic than the azoxystrobin TGAI alone to freshwater fish on

an acute exposure basis.

One degradate study with freshwater fish species observed no significant mortality at the limit

dose of 1 5 0 mg/L ; therefore, the com pound 2 degradate is at least >300 times less toxic than the

TGAI.

Acute estuarine/marine fish toxicity data with the TEP and degradate a re not available. Chronic fish toxicity data (both freshwater and estuarine/marine) with the degradate s a re not avail able

.

### 76 Chronic toxicity data with the TEP are typically not needed as the constituents in the formulation would not stay intact but likely dissipate at considerably different rates over time

.

IV.2.1.4 Risk Summary for Fish

Based on the available information, this ecological risk assessment for freshw ater and

estuarine/marine fish suggests potential for adverse effects on survival to freshwater and

estuarine/marine fish and aquatic

- phase amphibians from acute exposure to azoxystrobin as a result of foliar applications

. T here are no concerns on the freshwater fish species from acute exposure to the degradate ; however, there is a concern from exposure to the co

- formulated product

Renown ®



### , which is more toxic to freshwater fish due to the presence of t he other active ingredient,

chlorothalonil

. Formulated product and d egradate data were not available for estuarine/marine fish. For seed treatments, t he likelihood of adverse effects to fish from exposure to run

- off is considered

low

.

T he chronic RQ for adverse effects on r eproduction and growth to freshwater fish and aquatic

phase amphibians inhabiting in water bodies adjacent to pepper fields after a total treatment of three crop cycles equaled the chronic risk LOC; c hronic RQs for all other exposu re scenarios

modeled did not exceed the chronic risk LOC, including a single treatment of pepper sites. For estuarine/marine species, chronic exposure is expected to be minimal.



## Risk to Aquatic Invertebrates

IV.2.1.5. Risk to Invertebrates Exposed to Foliar Sprays of Azoxystrobin

Registrant

- submitted studies suggest that azoxystrobin is very highly toxic to estuarine/marine invertebrates and highly toxic to freshwater invertebrates. The most sensitive endpoint derived from the daphnid study for freshw ater invertebrates and from the available studies for estuarine/marine invertebrates ( mysid shrimp ) were compared to SWCC exposure scenarios for invertebrates inhabiting adjacent to crops treated with azoxystrobin

.

With estuarine/marine invertebrates more acutely sensitive than freshwater invertebrates , the acute RQs for estuarine/marine invertebrates exceed the a cute risk n on

- l isted s pecies, a cute r estricted

u se, and a cute risk to l isted s pecies LOCs following multiple azoxystrobin applications, whil e the

LOCs for acute restricted use and acute risk to listed species are only exceeded for freshwater invertebrates. The highest acute RQ of 2.7 for estuarine/marine invertebrates from foliar applicati ons using the highest EEC i s 54 times higher than the a cute risk to non

- listed species LOC

threshold of 0.05

. Only acute RQs for freshwater invertebrates inhabiting waters adjacent to wheat

use sites did not exceed the acute risk LOCs. In addition, unlike other aquatic taxonomic groups,

estuarine/marine invert ebrates are the only taxonomic group with RQs exceeding the acute risk LOC for azoxystrobin treatment in wheat use sites.

Of the acute studies submitted for estuarine/marine invertebrates, the crustacean (mysid) was more sensitive than the mollusk ( Pacific oyster); toxicity values range d from 56

– 1 3 00 μg a.i./L. To

assess the extent of estuarine/marine invertebrate species affected when exposed to azoxystrobin

,

### 77 a comparison of the least sensitive species ( oyster E C 50 

### of 1 3 00 μg a.i./L) and the most

conservative SWCC EEC using the pepper use scenario with three application cycles per year ( 150 μg a.i./L), the RQ is 0.1 and exceeds the acute restricted use and acute risk to listed species LOCs

. Thus it is anticipated that a range of estuarine/marine in vertebrates would both be adversely affected when exposed to azoxystrobin , however, more data on estuarine/marine invertebrates are needed to determine the distribution of invertebrate sensitivity to azoxystrobin . With the acute

freshwater invertebrate tox icity data limited to a single species , the range of freshwater

invertebrates’ sensitivity is unknown

.

Chronic RQ estimations for estuarine/marine invertebrates result in an exceedance of the c hronic

r isk LOC for all exposure scenarios

, while for freshwater invertebrates the exceedances a re limited

to potatoes and most leafy vegetable use scenario s except for lettuce after a single application crop cycle. The highest chronic RQ of 16 based on the most conservative scenario for estuarine/marine

spec ies was 16 ; whereas

, the LOC threshold is 1.0 for chronic risk to non

- listed and listed

freshwater invertebrates.

IV.2.1.6. Risk to Invertebrates Exposed to Azoxystrobin

- treated

S eed s

The daphnid and shrimp acute and chronic endpoints were compared to e xposure scenarios for azoxystrobin

- treated seed s with GENEEC and Rice models . Using the daphnid data, the highest acute RQ of 0.02 and chronic RQ of 0.14 for freshwater invertebrates inhabiting waters adjacent

to use sites with azoxystrobin

- treated seed s a re below the acute and chronic risk LOCs of 0.05 and 1.0, respectively. For estuarine/marine invertebrates usin g the shrimp data, the acute RQ of 0.07

- 0.1 for rice seed use sites exceed the a cute r estricted u se, and a cute risk to l isted s pecies LOCs ; while the acute RQs for all other use sites with azoxystrobin

- treated seed s d o not exceed the acute

risk LOCs.

IV.2.1.7. Formulated Product, Transformation Products, Non

Guideline Studies, Etc

.

RQs for freshwater invertebrates exposed to the degradates are not quantitatively calculated. The degradate data indicate the degradates are much less toxic than the TGAI to freshwater

invertebrates on an acute exposure basis. Three degradate studies with freshwater invertebrate species resulted in no significant mort ality at doses up to 190 mg/L, which indicate the degradates

are at least 700 times less toxic than the TGAI.

T oxicity data with the formulated products were not available

.

IV.2.1.8. Risk Summary for Aquatic Invertebrates

Based on the available information, this ecological risk assessment for freshwater and

estuarine/marine invertebrates suggests a potential for adverse effects on survival, reproduction and growth to freshwater and estuarine/marine invertebrates from acute and chronic exposure to azoxystrobin as a result of the current label uses.

### 78 The likelihood of adverse effect f rom acute exposure to the degr adates is considered low

.

For seed treatments, there is a concern for estuarine/marine invertebrates where treate d rice seed is planted

. The likelihood of adverse effects to estuarine/marine invertebrates due to run

- off from

other seed treatment sites and for freshwater invertebrates in all seed treatment sites is considered

low

.



## Risk to Aquatic Vascular and Non

- Vas cular Plants

IV.2.1.9. Risk to Aquatic Plants Exposed to Foliar Sprays of Azoxystrobin

T o evaluat e the potential exposure of foliar applications to non

- listed aquatic plants, t he EC 50 

### derived from the duckweed study for aquatic vascular plants and from the most sensitive aquatic

non

- vascular plants ( freshwater diatom ) were compared to SWCC exposure scenarios for plants inhabiting bodies of water adjacent to crops treated with azoxystrobin

. The RQ value s for non

listed aquatic non

- vascular plants using th e freshwater diatom exceed the LOC of 1 following

treatments on potatoes ( highest RQ = 1.1) and leafy vegetables ( highest RQ = 3.1 ). The RQs for

non

- listed aquatic vascular plants using the duckweed were all <0.1 and were below the LOC.

The most sensiti ve NOAEC derived from the duckweed study for aquatic vascular plants and from available studies for aquatic non

- vascular plants ( freshwater diatom) were compared to SWCC exposure scenarios for plants inhabiting bodies of water adjacent to sites treated with azoxystrobin

. The RQ value s for listed aquatic non

- vascular plants using the freshwater diatom all exceed the

LOC of 1 for risk to listed aquatic plants by factors as high as 7.5 following azoxystrobin applications . Listed plant RQs for aquat ic vascular plants using the duckweed were all <0.1 and

are below the LOC for risk to listed aquatic vascular plants.

Of the acceptable studies submitted for aquatic non

- vascular plants, the freshwater blue

- green alga was the least sensitive (EC 50 

### = 130 0 μg a.i./L with its corresponding NOAEC of 900 μg a.i./L );

overall sensitivit ies range between 50 to 1300 μg a.i./L for the non

- listed plant endpoint and between 20 to 900 μg a.i./L for the listed plant endpoint . To assess the range of non

- listed and

list ed aquatic non

- vascular species affected when exposed to azoxystrobin , a comparison of the least sensitive species (blue

- green algae EC 50 

### and NOAEC of 1300 and 900 μg a.i./L , respectively )

and the most conservative SWCC EEC using the pepper use scenario with three application crop cycles per year ( 150 μg a.i./L) results in an RQ of 0.1 and 0.2 , which is below the LOC for risk to

non

- listed and listed plants , respectively . Thus it is anticipated that not all aquatic nonvascular plants would be adversely a ffected when exposed to azoxystrobin. Aquatic vascular plants data

were limited to the duckweed study; therefore, the range of aquatic vascular plants adversely

affected to azoxystrobin applications could not be assessed.

IV.2.1.10. Risk to Aquatic Plant s Exposed to Azoxystrobin

- treated

S eed s

The toxicity endpoints for evaluating risk to non

- listed and listed aquatic vascular and nonvascular plant’s non

- listed and listed were compared to several exposure scenarios using GENEEC and

### 79 Rice models for aquatic flora inhabiting surface water adjacent to sites w here azoxystrobin

- treated

seed s are planted

. Non

- listed and listed RQs are less than 0.1 and a re below the LOC of 1.0 for

risk to non

- listed and listed species of aquatic plants

.

IV.2.1.11. Formulated Product, Transformation Products, Non

Guideline Studies, Etc.

The RQs for freshwater green algae exposed to the formulated product are not calculated. Toxicity

of the TEP Renown ® 

### Fungicide ( containing azoxystrobin and c hlorothalonil ) to fresh water green algae indicates the product is more toxic than the TGAI to aquatic nonvascular plants due to the presence of chlorothalonil, the other active ingredient. Effects of the degradates to freshwater diatom, the most sensitive aqua tic plant, or to the other nonvascular plant species a re not available

.

IV.2.1.12. Risk Summary for Aquatic Plants

This ecological risk assessment for aquatic plants suggests potential for adverse effects on survival and growth of non

- listed and listed non

- vascular plants from exposure to azoxystrobin as a result

of current uses label uses. The likelihood of adverse effects on vascular aquatic plants from

exposure to azoxystrobin is considered low

. Similarly, the likelihood of adv erse effects on nonvascular or vascular aquatic plants from exposure to runoff as a result of azoxystrobin

- treated seeds planted in areas adjacent to surface waters is considered low.

IV .2.2. Risks to Terrestrial Animals and Plants

In the conceptual mod el, dietary ingestion of azoxystrobin residues on vegetative matter and

insects including azoxystrobin

- treated seed s on treated areas are considered the most likely sources of azoxystrobin exposure to terrestrial animals. Spray drift, runoff and wind erosi on of soil particles with resulting residues on upland and/or wetland foliage and soil are the most likely sources of azoxystrobin exposure to non

- target terrestrial plants. Risks to terrestrial species ( i.e.

, birds, mammals, terrestrial invertebrates, and plants) are assessed based on modeled EECs and available toxicity data.

To characterize the extent to which RQs for terrestrial wildlife in adjacent habitats are affected by

distance from an azoxystrobin

- treated field, AgDRIFT was used ( Table IV.3 0 )

. T he spray drift

distances were estimated using LOCs divided by risk quotients (calculated based on a single application) as the “Fraction of Applied” in AgDRIFT to estimate the spray drift di stance for

terrestrial vertebrates . As the spray drift distance increases, the chance for exposure to non

- listed species outside a treated site increases. Since azoxystrobin is practically non

- toxic to bees on an acute exposure basis and resulting toxicity values are non

- definitive, RQ value s for terrestrial

invertebr ates were not calculated ; thus, terrestrial invertebrates a re no t included in the spray drift exposure analysis. In addition, the analysis was not performed for birds or mammals from acute

exposures since azoxystrobin is practically non

- toxic to these taxa as well and again toxicity

estimates were non

- definitive and RQs were not calculated . Also, since chronic RQ values are below the chronic risk LOC, these were not further analyzed

.

### 80 This spray drift exposure analysis indicates that when aerial

- based app lication methods are used (which produces the highest exposures) at the maximum label rate of 0.4 lb a.i./A, there were no

chronic risk LOC exceedances for non

- listed mammals beyond the edge of the treated field ( 0 feet). With ground

- based applications at the ma ximum label rate of 0.55 lb a.i./A, the RQ is

below the chronic risk to non

- listed species LOC at a distance of 3 feet off

- site from the edge of

a treated field. Therefore, the likelihood of adverse effects to non

- listed terrestrial species in untreated areas adjacent to a treated site exposed to off

- site spray drift alone is considered low

.

Inhalation of Azoxystrobin in Treated Fields

The Screening Tool for Inhalation Risk (STIR v.1.0 ) was used to calculate an upper

- bound estimate of wildlife inhalation exposure using azoxystrobin vapor pressure and molecular weight as well as the maximum application rate. STIR incorporates results from several toxicity studies including the rat acute oral ( LD 50 

### >5000 mg/kg

- bw ) and inhalation toxicity (female LC 50 

### = 0.698 mg/L ) as well as the most sensitive acute oral avian toxicity endpoint (mallard LD 50 

### >2000 mg/kg

bw). Based on the results of the STIR model ( Appendix 2 ), exposure through inhalation of spray drift or the vapor phase of azoxystrobin is not a potential pathway of concern for either avian or mammalian species on an acute exposure basis. Table IV.3 0

. AgDRIFT (Terrestrial) Assessment for Non

- Listed Terrestrial Vertebrate Species Exposed to Ground Spray at 0.55 lb a. i./A and to Aerial Spray at 0.4 lb a.i./A of Azoxystrobin

Taxa Type of Endpoint Highest Risk Quotient Non

- listed Species

LOC Fraction of Applied ( Non

listed LOC/RQ) Distance from Edge of Field Where RQ Falls

below LOC

Aerial Application of 0.4 lb a.i./A

Birds Acute RQs not calculated due to non

- definitive values

Chronic No LOC exceedances

Mammals Acute RQs not calculated due to non

- definitive values

Chronic 2.8 1 0.36 0 feet

Ground application of 0.55 lb a.i./A

Birds Acute RQs not calculated due to non

- definitive values

Chronic No LOC exceedances

Mammals Acute RQs not calculated due to non

- definitive values

Chronic 3.8 1 0.26 3 feet

### 81 The analysis of the inhalation route in STIR does not consider that aggregation with other exposure pathways such as dietary, dermal, or drinking water may contribute to a total exposure that has a potential for effects to non

- target animals. However, the Agency does consider the relative importance of other routes of exposure in situations where data indicate that pesticide exposures through other routes may be potentially significant contributors to wildlife risk (USEPA 2004).

The risk characterization s ection ( Section IV.2 ), discusses the impact of consideration of other routes of exposure that have been identified as potentially important and the degree of certainty associated with screening

- level risk assessment conclusions. Detailed information about STIR v.1.0, as well as the tool, can be found on EPA’s website ( http://www2.epa.gov/pesticide

- science

and

- assessing

- pesticide

- risks/models

- pesticide

- risk

- assessment#terrestrial )

.

Ingestion of Azoxystrobin through Drinking Water Alone

The Screening Imbibition Program (SIP v.1.0, released June 15, 2010) was used to ca lculate an

upper

- bound estimate of wildlife drinking water exposure using azoxystrobin solubility ( i.e ., 6.7 mg/L at 20 o 

### C), and compared to the most sensitive acute and chronic avian and mammalian toxicity endpoints. Based on results of the screening mode l SIP for azoxystrobin, drinking water exposure alone is NOT a concern for birds and mammals ( Appendix 3 ). For a sample of the output generated by SIP v.1.0, please see Appendix 3 . Detailed information about the SIP v.1.0, as well as the tool, can be found on the EPA’s website at http://www2.epa.gov/pesticide

- science

- and

assessing

- pesticide

- risks/models

- pesticide

- risk

- assessm ent#terrestrial

.

Exposure through Ingestion of A quatic O rganisms Containing Azoxystrobin Residues

Azoxystrobin has a low octanol

- water partitioning coefficient (K
ow 

### = 316)

, which indicates that the likelihood the compound will accumulat e in aquatic food chains is low . A s of a result, a n assessment using the Agency’s KABAM model ( K ow 

### (based) Aquatic BioAc cumulation Model;

v1.0 ) for pisciv or ous birds and mammals was unnecessary.



## Risk to Birds

IV.2.2.1 Risk to Birds Exposed to Foliar Sprays of Azoxystrobin

Available avian acute toxicity data indicate that azoxystrobin is practically non

- toxic to birds on

both an acute oral and subacute dietary exposure basis ( e.g. , LD 50 

### >2000 mg a.i./kg bw and

LC 50 

### >5200 mg a.i./kg diet). Due to non

- definitive va lues, the likelihood of adverse effects birds following acute exposure is anticipated to be low.

Chronic avian RQs for broadcast spray of azoxystrobin were below the chronic risk LOC of 1, with a calculated maximum RQ of 0. 2

. Chronic avian RQs for seed t reatment were below the chronic risk LOC of 1, the highest RQ was 0.2.

No mortalities were observed in the acute studies with birds , yet sub

- lethal effects were observed in the reproduction studies at 30 00 mg a.i./kg diet and higher.

IV.2.2.2. Risk to Birds Exposed to Azoxystrobin

- treated S eed s

### 82 For azoxystrobin

- treated seed s
, depending on which formulated product was used, the RQs exceed

the chronic risk LOC for birds of all body weight classes foraging on azoxystrobin

- treated popcorn, sweet corn and sunflower seed s

. The chronic risk LOC i s not exceeded for birds for field corn or any of the other seed treatments evaluated

.

IV.2.2.3 Risk Summary for Birds

There is a potential for adverse effects on reproduction and growth to birds from chronic consumption of azoxystrobin

- treated seed s in cornfields grown for popcorn and sweet corn and in

sunflower fields as a r esult of current seed treatment rates

. Th e adverse effects discussed above

would be observed for those birds that rem ain in a treated site and feed exclusively on azoxystrobin

- treated seed s. However, the likelihood of adverse effects to birds from acute

exposure to azoxystrobin

- treated seeds is considered low.

No risk concerns are identified for birds exposed to azoxystrobin residues on food resources as a result of foliar applications.

The Screening Imbibition Program model (SIP) and the Screening Tool for Inhalation Risk model (STIR) indicate low concern for birds and mammals exposed to az oxystrobin through drinking water and inhalation.

Risks to Mammals

IV.2.2.4. Risk to Mammals Exposed to Foliar Sprays of Azoxystrobin

Available mammalian acute toxicity data indicate that azoxystrobin is practically non

- toxic to

mammals on an acute oral exposure basis. Due to non

- definitive values

, the likelihood of adverse

effects to mammals from acute exposure is anticipated to be low

.

Based on the most sensitive mammalian 2

- generation NOAEL and upper bound T

- REX EECs, the

dose

- based RQs of 1

- 8 excee d the chronic risk LOC for 15 g, 35 g and 1000 g mammals foraging on short grass, tall grass, broadleaves and arthropods following azoxystrobin applications at the

maximum label rate to turf

. Thus, these exceedances indicate mammals there is a potential for adverse effects on reproduction and growth from chronic exposure to azox ystrobin as a result of

the labeled uses of the fungicide when using a reviewer

- calculated foliar dissipation half

- life of

14.9 days and the maximum exposure use scenario

. Although a shorter foliar dissipation half

- life

did not r educe RQ values below the chronic risk LOC

, reducing the number of applications from 9 applications to 2 applications or less would reduce the RQ to below the chronic risk LOC. In addition, none of the dietary

- based RQs exceeded the chronic risk LOC for mammals of all body weight sizes foraging on any of the selected food items.

IV.2.2.5. Risk to Mammals Exposed to Azoxystrobin

- treated

S eed s

### 83 For azoxystrobin

- treated seed s depending on which formul ated product i s used

, the dose

- based RQs exceed the chronic risk LOC for mammals of all body weight classes foraging exclusively on azoxystrobin

- treated corn and sunflower seed s ; for 15g and 35g mammals foraging on azoxystrobin

- treated head/stem brassica and sorghum seeds; and for 15g mammals foraging on azoxystrobin

- treated cotton seeds. The chronic risk LOC i s not exceeded for mammals foraging on azoxystrobin

- treated soybean, rice, and legume vegetable seed trea tments.

IV.2.2.6. Risk Summary for Mammals

F or mammals, there is a potential for adverse effects from chronic exposure to azoxystrobin as a

result of current uses label uses , including seed treatments

. The likelihood of a dverse effects would

be increased for those mammals that remain in a treated site all the time and forag e exclusively on food items containing azoxystrobin residues or azoxystrobin

- treated seed s. The likelihood of adverse effects to mammals from acute exposure following foliar application s or consumption of azoxystrobin

- treated seed is considered low.



## Risk to Terrestrial Plants

IV.2.2.7. Risk to Terrestrial Plants Exposed to Foliar Sprays of Azoxystrobin

Based on the available data, monocots were not sensitive to azoxystrobin as none were inhibited 25% or more in the seedling emergence or vegetative vigor tests. However, two dicots out of 6 were inhibited more than 25% and tier II testing was conducted on these two dicots to establish measurement endpoints . The RQs from T err PLANT for runoff to semi

- aquatic areas result in the highest RQs compared to dry areas. This scenario represents a 10

- acre area running off into a one

acre area. The highest RQ for a combination of runoff and spray drift from 10 acre in to an one acre semi

- aquatic area is 0.12

, resulting from a rate o f 0.06 lb a.i./A , which does not exceed the Agency’s LOC of 1 for risk to plants.

For spray drift alone, AgDRIFT indicates that for aerial

- based applications at the maximum single application rate o f 0.4 lb a.i./A did not exceed terrestrial plant LOC beyond the actual treatment

site

, while for ground

- based applications at the maximum single application rate of 0.55 lb a.i./A

, the highest RQ of 1.1 drops below the LOC for risk to listed terrestrial plants at approximately 5

feet from the treatment site . This suggests that effects to non

- listed terrestrial plants would not occur outside the site of application.

IV.2.2.8. Risk to Terrestrial Plants Exposed to Azoxystrob in

trea ted S eed s

The phytotoxicity endpoints for non

- listed and listed terrestrial plants were compared to several exposure scenarios using TerrPLANT for plants inhabiting sites adjacent to use sites with azoxystrobin

- treated seed s. The RQs for non

- listed plants and listed plants are <0.1 for terrestrial plants inhabiting in dry and semi

- aquatic areas adjacent to use sites with azoxystrobin

- treated seed s and are below the LOC of 1.0.

### 84 IV.2.2.9. Risk Summary for Terrestrial Plants

Overall, there is a potential for adverse effects on survival and growth of terrestrial dicots that

inhabit areas adjacent to azoxystrobin

- treated fields and which are exposed through spray drift

alone. The likelihood of adverse effects to terrestrial plants inhabiting both dry and semi

- aquatic areas subjected to both surface water runoff and spray drift with azoxystrobin residues and to monocots subjected to spray drift alone is considered low

. In addition, the incident data reported 35 instances of adverse effects to terrestrial plants as a result of being treated directly or from exposure to spray drift

. 18 incidents were as a result of registered uses, 8 from misuse, and the remaining were undetermined or not reported.



## Risk to Terrestrial Invertebrates

IV.2.2.10. Risk to Terrestrial Invertebrates Exposed to Azoxystrobin

The available terrestrial invertebrates toxicity data, based on tests with honey bee s, suggest that the TGAI is practically non

- toxic to adult bees on an acute contact and oral exposure basis. Th e
LD 50 

### value was >2 00 and >25 μg a.i./bee. Terrestrial invertebrates were not assessed quantitatively as the acute toxicity values for adult bees are non

- definitive. No data are available for assessing the acute effects of azoxystrobin on larval bees and no data are available to assess the chronic effects of azoxystrobin on either adult or larval bees. Thus, additional data 5 

### on the acute and chronic toxicity of azoxystrobin to larval bees and the chronic toxicity to adult bees are needed to
address the unc ertainty.

IV.2.2.11. Risk Summary for Terrestrial Invertebrates

The complete set of toxicity data for honey bees is not available; until data set is complete, the re is uncertainty regarding potential risk to terrestrial invertebrates.



# V. FEDERALLY THREA TENED AND ENDANGERED (LISTED) SPECIES

CONCERNS

In November 2013, the EPA, along with the U.S. Fish & Wildlife Service (USFWS), the National Marine Fisheries Service (NMFS) (collectively, the Services) , and the U.S. Department of Agriculture (USDA) released a summary of their joint Interim Approaches for assessing risks to

5 A complete set of toxicity data for honey bee adults and larvae have not been submitted for azoxystrobin and are now needed u nder EPA’s recent guidance on pollinator protection 5 . Thus, the following honey bee studies have yet to be submitted for azoxystrobin:

o Honey bee larval acute [single dose] toxicity study (following OECD 237)

o Honey bee adult 10

- day chronic [repeat dose] (special study)

o Honey bee larval [repeat dose] study (special study)

o Field testing for pollinators (OCSPP 850.3040, Tier III)

o Field trial of residues in pollen and nectar (special study, Tier II)

o Semi

- field testing for pollinators (special study, Tier II).

The need for higher Tier semi

- field and full field pollinator studies for azoxystrobin will be determined after review of the Tier I studies.

### 85 listed species from pesticides. The Interim Approaches were developed jointly by the agencies in response to the National Academy o f Sciences’ (NAS) recommendations and reflect a common approach to risk assessment shared by the agencies as a way of addressing scientific differences

between the EPA and the Services. The NAS report outlines recommendations on specific

scientific and te chnical issues related to the development of pesticide risk assessments that EPA and the Services must conduct in connection with their obligations under the Endangered Species Act (ESA) and FIFRA.

The joint Interim Approaches were released prior to a st akeholder workshop held on November 15, 2013. In addition, the EPA presented the joint Interim Approaches at the December 2013 Pesticide Program Dialogue Committee (PPDC) and State

- FIFRA Issues Research and Evaluation Group ( SFIREG) meetings, and held a s takeholder workshop in April 2014, allowing additional opportunities for stakeholders to comment on the Interim Approaches. As part of a phased, iterative process for developing the Interim Approaches, the agencies will also consider public

comments on th e Interim Approaches in connection with the development of upcoming Registration Review decisions. The details of the joint Interim Approaches are contained in the white paper “Interim Approaches for National

- Level Pesticide Endangered Species Act

Asses sments Based on the Recommendations of the National Academy of Sciences April 2013 Report,” dated November 1, 2013.

Given that the agencies are continuing to develop and work toward implementation of the Interim Approaches to assess the potential risks of pesticides to listed species and their designated critical habitat, this preliminary risk assessment for azoxystrobin does not contain a complete ESA analysis that includes effects determinations for specific listed species or designated critical

habit at. Although EPA has not yet completed effects determinations for specific species or habitats, for this preliminary assessment EPA conducted a screening

- level assessment for all taxa

of non

- target wildlife and plants that assumes for the sake of the asses sment that listed species and designated critical habitats may be present in the vicinity of the application of azoxystrobin . This screening level assessment will allow EPA to focus its future evaluations on the types of species where the potential for e ffects exists once the scientific methods being developed by the agencies have been fully vetted. This screening

- level risk assessment for azoxystrobin indicates potential risks of direct effects to listed terrestrial plants. Listed species of plant

- depen dent taxa may also be affected through indirect effects because of the potential for direct effects on listed and non

listed species upon which such species may rely. Potential direct effects on listed terrestrial plants

from the use of azoxystrobin may b e associated with modification of Primary Constituent Elements (PCEs) of designated critical habitats, where such designations have been made. Once the agencies have fully developed and implemented the scientific methods necessary to complete risk

assessm ents for endangered and threatened (listed) species and their designated critical habitats, these methods will be applied to subsequent analyses for azoxystrobin as part of completing this registration review.



## V.1

. Endocrine Disruptor Screening Program

As required by FIFRA and FFDCA, EPA reviews numerous studies to assess potential adverse outcomes from exposure to chemicals. Collectively, these studies include acute, subchronic and chronic toxicity, including assessments of carcinogenicity, neurotoxic ity, developmental,

### 86 reproductive, and general or systemic toxicity. These studies include endpoints

, which may be susceptible to endocrine influence, including effects on endocrine target organ histopathology, organ weights, estrus cyclicity, sexual matura tion, fertility, pregnancy rates, reproductive loss, and sex ratios in offspring. For ecological hazard assessments, EPA evaluates acute tests and chronic studies that assess growth, developmental and reproductive effects in different taxonomic groups.

A s part of registration review for azoxystrobin, EPA reviewed these data and selected the most sensitive endpoints for relevant risk assessment scenarios from the existing hazard database. However, as required by FFDCA section 408(p), azoxystrobin is subje ct to the endocrine screening part of the Endocrine Disruptor Screening Program (EDSP).

EPA has developed the EDSP to determine whether certain substances (including pesticide active and other ingredients) may have an effect in humans or wildlife similar to an effect produced by a “naturally occurring estrogen, or other such endocrine effects as the Administrator may designate.” The EDSP employs a two

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

adverse endocrine

- related effects caused by the su bstance, and establish a dose

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

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

- ins for the first group of 67 chemicals, which contains 58 pesticide active ingredients and 9 inert ingredients. A second list of chemicals identified for EDSP screening was published on June 14, 2013 6 

### and includes some pesticides scheduled for registration revie w and chemicals found in water

. Neither of these lists should be construed as a list of known or likely endocrine disruptors. Azoxystrobin is not on List 1. For further information on the status of the EDSP, the policies and procedures, the lists of chemic als, future lists, the test guidelines and the Tier 1 screening battery, please visit our website. 7



### References

U.S. EPA 2009. Registration Review

– Preliminary Problem Formulation for the Ecological Risk and Drinking Water Exposure Assessments for Azoxystrobin. Dated October 21, 2009.

D365654.

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

- HQ

- OPPT

- 2009

- 0477

- 0074 for the final second list of

chemicals.

7 http://www2.epa.gov/endocrine

- disruption/endocrine

- disruptor

- screening

- program

- edsp

- overview

### 87 U.S. EPA. 2004. Overview of the Ecological Risk Assessment Process in the Off ice of Pesticide
Programs. January 23, 2004. Office of Pesticide Programs. Office of Prevention, Pesticides, and Toxic Substances. Washington, D.C.

Guidelines for Ecological Risk Assessment, United States Environmental Protection Agency.

EPA/630/R

- 95/002F. April 1998.

Mullin, CA, et al. “High Levels of Miticides and Agrochemicals in North American Apiaries: Implications for Honey Bee Health.” PLoS ONE 5.3 (2010): e9754. Web. http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0009754.doi:10.1 371/journal.pone.0009754

Pettis, J.S., E. M. Lichtenberg, M. And ree, J. Stitzinger, R. Rose, and D. vanEngelsdorp. 2013. Crop Pollination Exposes Honey Bees to Pesticides which Alters their Susceptibility to the Gut Pathogen Nosema ceranae . PLoS One 8(7): e70182. Doi:10.1371/journal.pone.0070182.

Stoner, K.A., and B.D. Eitzer. “Using a Hazard Quotient to Evaluate Pesticide Residues Detected in Pollen Trapped from Honey Bees ( Apis mellifera ) in Connecticut” PLoS ONE 8.1 (2013): e77550. doi: 10.1371/journal.pone.0077550.

Rennich, K., et al . “2011

- 2012 National Honey Bee Pests and Diseases Survey Report.” USDA Animal Plant and Health Inspection (2012) Available at

< http://www.aphis.usda.gov/plant _health/plant_pest_info/honey_bees/downloads/2011_Nat ional_Survey_Report.pdf >.

USEPA. 2013. Pesticides: Science and Policy. Terrestrial Models, T

- REX Version 1.5.2. http://www2.epa.gov/pesticide

- science

- and

- assessing

- pesticide

- risks/models

- pesticide

risk

- assessment#terrestrial

Fletcher e t al. (1994). Literature review and evaluation of the EPA food

- chain (Kenaga) nomogram in instruments for estimating pesticide residues on plants . Envir. Tox. And

Chem. 9:1383

- 1391.

Hoerger and Kenaga, 1972. Pesticides residues on plants: Correlation of r epresentative data as basis for estimation of their magnitude in the environment. Envir. Quality. Vol. 1, Academic Press, New York, pp. 9

- 28.

### 88 Appendix 1. Table 1. .Azoxystrobin and its degradation products in soil and water.

Common Name

Chemical Name Structure Substrate (maximum % of applied radioactivity.

Azoxystrobin

methyl (E)

- 2

- {2

- [6

- (2

- cyanophenoxy)pyrimidin

- 4

- yloxy]

- phenyl}

- 3

- methoxyacrylate Parent Compound

Z isomer; Compound 9

methyl (Z)

- 2

- {2

- [6

- (2

- cyano

phenoxy)pyrimidin

- 4

- yloxy]

- phenyl}

- 3

- methoxyacrylate Aqueous photolysis (15.0%)

Soil photolysis (9.0%)

Compound 2

(E)

- 2

- {2

- [6

- (2

- cyanophenoxy)

- pyrimidin

4

- yloxy]phenyl}

- 3

- methoxyacrylic acid Aerobic soil metabolism (28%)

Anaerobic soil metabolism (68%)

Compound 3

methyl (E)

- 2

- [2

- (6

- hydroxy

- pyrimidin

- 4

- yloxy)phenyl]

- 3

- methoxyacrylate Aerobic soil metabolism (3.1%)

Anaerobic soil metabolism (0.6%)

Soil Photolysis (0.7%)

Compound 13

2

- hydroxybenzonitrile Aqueous photolysis (1.7%)

Soil photolysis (<3.5%)

Compound 19

methyl 2

- {2

- [6

- (2

- cyanophenoxy)

- pyrimidin

- 4

- yloxy]phenyl}

- oxoacetate Soil photolysis (<6.0%)

### 89 Appendix 1. Table 1. .Azoxystrobin and its degradation products in soil and water.

Common Name

Chemical Name Structure Substrate (maximum % of applied radioactivity.

Compound 21

Methyl {2

- [6

- (2

- cyanophenoxy) pyrimidin

- 4

- yloxy]phenyl}acetate Aqueous photolysis (5.6%)

Compound 24

methyl 2

- {2

- [6

- (2

- cyanophenoxy)

- pyrimidin

- 4

- yloxy]phenyl}glycolate Aqueous photolysis (<2.6%)

Soil photolysis (<3.2%)

Compound 28

4

- (2

- cyanophenoxy)

- 6

- hydroxypyrimidine Aerobic soil metabolism (3.1%)

Anaerobic soil metabolism (4.2%)

Aqueous photolysis (8.9 %)

Soil photolysis (< 6.5%)

Compound 30

2

- [6

- (2

- cyanophenoxy)pyrimidin

- 4

- yloxy]benzoic acid Aerobic soil metabolism (2.8%)

Anaerobic soil metabolism (<2.8%)

Aqueous photolysis (2.4%)

Soil photolysis (<5.0%)

Compound 36

methyl (E)

- 2

- {2

- [6

- (2

- carbamoyl

phenoxy)pyrimidin

- 4

- yloxy]

- phenyl}

- 3

- methoxyacrylic acid Aerobic soil metabolism (2.8%)

Anaerobic soil metabolism (<2.8%)

Compound U13

methyl 3

- [6

- (cyanophenoxy)pyrimidin

- 4

- yloxy]

- 2

- methoxy

- 3H

- 3 benzofuroate Soil Photolysis (<5.2%)

### 90 Appendix 2: STIR



# Input

Application and Chemical Information

Enter Chemical Name azoxystrobin

Enter Chemical Use all Is the Application a Spray? (enter y or n) y
If Spray What Type (enter ground or air) ground Enter Chemical Molecular Weight (g/mole) 403.4 Enter Chemical Vapor Pressure (mmHg) 8.20E

- 13 Enter Application Rate (lb a.i./acre) 0.55

Toxicity Properties

**Bird**

Enter Lowest Bird Oral LD 50 (mg/kg bw) 2000 Enter Mineau Scaling Factor 1.15 Enter Tested Bird Weight (kg) 0.178

**Mammal**

Enter Lowest Rat Oral LD 50 (mg/kg bw) 5000

Enter Lowest Rat Inhalation LC 50 (mg/L) 0.698 Duration of Rat Inhalation Study (hrs) 4 Enter Rat Weight (kg) 0.35



# Output

Results Avian (0.020 kg )
Maximum Vapor Concentration in Air at Saturation (mg/m 3 ) 1.78E

- 08

Maximum 1

- hour Vapor Inhalation Dose (mg/kg) 2.24E

- 09

Adjusted Inhalation LD 50 1.56E+00

Ratio of Vapor Dose to Adjusted Inhalation LD 50 1.44E

- 09 Exposure not Likely Significant

Maximum Post

- treatment Spray Inhalation Dose (mg/kg) 5.81E

- 02 Ratio of Droplet Inhalation Dose to Adjusted Inhalation

LD 50 3.73E

- 02 Exposure not Likely Significant



### Results Mammalian (0.015 kg )
Maximum Vapor Concentration in Air at Saturation (mg/m 3 ) 1.78E

- 08

Maximum 1

- hour Vapor Inhalation Dose (mg/kg) 2.81E

- 09

Adjusted Inhalation LD 50 4.16E+01

Ratio of Vapor Dose to Adjusted Inhalation LD 50 6.77E

- 11 Exposure not Likely Significant

Maximum Post

- treatment Spray Inhalation Dose (mg/kg) 7.31E

- 02 Ratio of Droplet Inhalation Dose to Adjusted Inhalation

LD 50 1.76E

- 03 Exposure not Likely Significant

### 91 Appendix 3: SIP

Table 1. Inputs

Parameter Value

Chemical name azoxy Solubility (in water at 25 o C; mg/L) 6.7

Mammalian LD 50 (mg/kg

- bw) 5000
Mammalian test species laboratory rat Body weight (g) of "other" mammalian species

Mammalian NOAEL (mg/kg

- bw) 15
Mammalian test species laboratory rat Body weight (g) of "other" mammalian species

Avian LD 50 (mg/kg

- bw) 2000
Avian test species mallard duck Body weight (g) of "other" avian species Mineau scaling factor 1.15

Mallard NOAEC (mg/kg

- diet) 1200 Bobwhite quail NOAEC (mg/kg

- diet) NOAEC (mg/kg

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

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

Table 2. Mammalian Results

Parameter Acute Chronic Upper bound exposure (mg/kg

- bw) 1.1524 1.1524 Adjusted toxicity value (mg/kg

- bw) 3845.8028 11.5374 Ratio of exposure to toxicity 0.0003 0.0999

Conclusion* Drinking water exposure
alone is NOT a potential

concern for mammals Drinking water exposure alone is NOT a potential

concern for mammals

Table 3. Avian Results

Parameter Acute Chronic Upper bound exposure (mg/kg

- bw) 5.4270 5.4270 Adjusted toxicity value (mg/kg

- bw) 1038.4508 59.5351 Ratio of exposure to acute toxicity 0.0052 0.0912

Conclusion* Drinking water exposure alone is NOT a potential

concern for birds Drinking water exposure alone is NOT a potential

concern for birds

*Conclusion is for drinking water exposure alone. This does not combine all routes of exposure. Therefore, when aggregated with other routes ( i.e ., diet, inhalation, dermal), pesticide exposure through drinking water may contribute to a total exposure that has potential for effects to no n

- target animals.