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

OFFICE OF CHEMICAL SAFETY AND POLLUTION PREVENTION



### PC Code: 128997 DP Barcode: D 427434 Date: November 24 , 2015



### MEMORANDUM

Subject: Registration Review

– Preliminary Problem Formulation for Ecological Risk and Drinking Water Assessments for Tebuconazole

To: Jose Gayoso

, Chemical Review Manager Cathryn Britton, Team Leader Kevin Costello , Branch Chief Risk Management and Implementation Branch 2 Pesticide Re

- evaluation Division ( 7508P )

Rachel Ricciardi , Chemical Review Manager Regulatory Management Branch II Antimicrobials Division (7510P)

From: Amy Blankinship

, Senior Scientist Ibrahim Abdel

- Sa heb, Environmental Scientist Environmental Risk Branch 6 Environmental Fate and Effects Division (7507P)

James Breithaupt, Agronomist for Daniel Cherry, Biologist Siroos Mostaghimi, Ph.D., Senior Scientist Risk Assessment and Science Support Branch Antimicrobial s Division (7510P)

Reviewed: Nathan Miller, Biologist William P. Eckel, Ph.D, Senior Science Advisor Monica Wait , Risk Assessment Process Leader Environmental Risk Branch 6 Environmental Fate and Effects Division (7507P)

Through: Mark Corbin , Branch Chief Environmental Risk Branch 6 Environmental Fate and Effects Division (7507P)

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

The Environmental Fate and Effects Division (EFED) and Antimicrobials Division (AD) ha ve completed the preliminary problem formulation for the ecological risk and drinking water exposure assessments to be conducted as part of the Registration Review of the fungicide tebuconazole (PC Code 128997). This document is intended to provide an overview of what is currently known regarding the environmental fate and ecological effects associated with tebuconazole and its transformation/ degradation products

. It descr ibes the preliminary ecological risk hypothesis and the processes that will be used during the completion of drinking water and ecological risk assessments in support of Registration Review. Tebuconazole is registered as a conventional pesticide with agri cultural and non

- agricultural use patterns and as an antimicrobial pesticide with uses such as above

- ground and ground

- contact wood and wood

- based composites

, and as a materials preservative in plastic, glues, adhesives, and metalworking fluids.

A dditional ecological effects and environmental fate data are requested to complete the risk assessment and registration review process for conventional tebuconazole uses

. Toxicity data for passeri nes, benthic invertebrates, aquatic nonvascular plants

, hone y bees , and multiple concentration ( Tier II ) seedling emergence and vegetative vigor terrestrial plant testing are requested to support conventional uses

. Analytical methods in water and soil with LOQs less than toxicological levels of concern are also req uested to support conventional uses

. Additional ecological effects data are requested to complete the risk assessment and registration review process for antimicrobial tebuconazole uses

. Toxicity data for benthic invertebrates and aquatic nonvascular plan ts which are requested for the conventional uses will also be used to support antimicrobial uses. Additional environmental fate data to support a down the drain assessment are also requested for the antimicrobial uses which may result in down the drain
exp osures.

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# Problem Formulation for the Ecological Risk and Drinking Water Assessments in Support of the Registration Review of Tebuconazole

[α

- [2

- (4

- chlorophenyl)ethyl]

- α - (1,1

- dimethyl)

- 1H

- 1,2,4

- triazole

- 1

- ethanol] CAS Registry No.: 107534

- 96

- 3 PC Code: 128997

Environmental Fate and Effects Division: Environmental Risk Branch V I Ibrahim Abdel

- Saheb, Ph.D, Environmental Scientist Amy Blankinship, Senior Scientist

Reviewed by: Nathan Miller, Biologist William P. Eckel, Ph.D, Senior Science Advisor Monica Wait

, Risk Assessment Process Leader Mark Corbin , Branch Chief U. S. Environmental Protection Agency Office of Pesticide Programs 1200 Pennsylvania Ave., NW Mail Code 7507P Washington, DC 20460

A ntimicrobials Division : Risk Assessment and Science Support Branch James Breithaupt, Agronomist Daniel Cherry, Biologist Siroos Mostaghimi, Ph.D, Senior Scientist

Reviewed by: 

### Laura Parsons, Associate Branch Chief N N

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### Table of Contents

1. Executive Summary

................................ ................................ ................................ ................... 5 2. Introduction

................................ ................................ ................................ ............................... 7 3. Use Characterization

................................ ................................ ................................ .................. 8 4. Conclusions from Previous Risk Assessments

................................ ................................ ........ 14 5. Environmental Fate and Transport

................................ ................................ .......................... 15 6. Receptors

................................ ................................ ................................ ................................ . 22 7. Exposure Pathways of Concern

................................ ................................ ............................... 31 8. Analysis Plan

................................ ................................ ................................ ........................... 32 8.1 Stressors of Concern

................................ ................................ ................................ ......... 32 8.2 Measures of Exposure

................................ ................................ ................................ ...... 33 8.3 Measures of Effect

................................ ................................ ................................ ........... 34 9. Endangered Species Assessment

................................ ................................ ............................. 34 10. Endocrine Disruptor Screening Program

................................ ................................ ................. 35 11. Preliminary Identification of Data Gaps

................................ ................................ .................. 36 12. References

................................ ................................ ................................ ................................ 47 Appendix A. Toxicity Data for Tebuconazole

................................ ................................ ........... 48 Appendix B. Screening Level Models to Evaluate Potential Importance of Drinking Water and Inhalation Exposure Pathways to Birds and Wild Mammals

................................ ..................... 54 Appendix C. TerrPlant results

................................ ................................ ................................ ..... 56

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# 1. Executive S ummary

The Environmental Fate and Effects Division (EFED) and Antimicrobials Division (AD) ha ve completed the preliminary problem formulation for the ecological risk and drinking water assessments to be conducted as part of the registration rev iew of tebuconazole (PC Co de 128997 )

. The problem formulation describes the methods to be used for the drinking water and ecological risk assessments in support of registration review and provides an overview of the environmental fate, ecological effects, and potential risks as sociated with the use of tebuconazole as well as uncertainties uniqu e to its risk assessment

. This document also identifies additional studies that would be beneficial to the conduct of an ecological risk assessment. If the additio nal recommended toxicity data are not available, EFED may presume risk to those tax a from the conventional uses

. Data needs for ecological effects are:

Conventional Uses

Honeybee Toxicity Data :

Tier 1:

• Adult Honey Bee Acute Contact Toxicity (850.3020) using TGAI

• Adult Honey Bee Acute Oral Toxicity (non

- guideline ) using TGAI

• Adult Honey Bee Chronic Oral Toxicity (non

- guideline) using TGAI

• Larval Honey Bee Acute Oral Toxicity (non

- guideline) using TGAI

• Larval Honey Bee Chronic Oral Toxicity (non

- guidelin e) using TGAI

• Honey Bee Toxicity of Residues on Foliage ( 850.3030 ) Tier 2 :

• Semi

- Field Testing for Pollinators (non

- guideline)

— may be waived pending the results of the lower tier larval and adult honey bee acute and chronic oral toxicity studies Tier 3:

• Field Trial of residues in pollen and nectar (non

- guideline)

- may be waived pending the results of the lower tier larval and adult honey bee acute and chronic oral toxicity studies

• Field Testing for Pollinators (850.3040)

— may be waived pending the results of the lower tier larval and adult honey bee acute and chronic oral toxicity studies

While, a cute oral and contact toxicity studies with adult honey bees are available for end

- use products that contain tebuconazole , a dult and larval honey bee toxicity t esting with TGAI is not available . As such, Tier 1 toxicity testing with TGAI consistent with the pollinator framework is recommend. Depending on the results of Tier 1 testing, additional testing may be requested.

Tier II Te rrestrial Plant Toxicity Dat a:

• Seedling Emergence (850.4 100 ) using a TEP

• Vegetative Vigor (850.4 150 ) using a TEP

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### T he Tier I terrestrial plant toxicity testing resulted in no observed adverse effect concentration ( NOAEC ) values that were less than the limit concentrations (NOAEC< 0.4 lb a.i./A) for monocots for seedling emergence testing and for monocots and dicots for vegetative vigor testing . As such, additional testing is requested in an effort to obtain definitive terrestrial plant toxicity values

. While testing using a dose

- response test design (Tier II) is preferred, Tier I testing may be acceptable if the requirements as outlined in OCSPP 850.4100 and 850.4150 are met for all tested species

.

Sediment (benthic invertebrate) Toxicity Data:

• Freshwater C hronic Sediment Toxicity ( non

- guideline ) using TGAI for two species of freshwater invertebrates

• Estuarine/marine Chronic Sediment Toxicity ( non

- guideline ) using TGAI for one species of estuarine/marine invertebrates

Given the persistence of tebuconazole and its affinity to bind to soil, sediment

- dwelling organisms may be exposed. Toxicity data which indicates that tebucon a zole affects the developmental rate of sediment

- dwelling invertebrates are available. However, toxicity data evaluating reproductive effects are not a vailable. Since reproductive effects have been observed in other aquatic invertebrates, chronic sediment toxicity data which includes evaluation of reproduction is requested

.
Aquatic Non

- vascular Plant Toxicity Data:

• Algal Toxicity (850.4500) using TGAI for two species of non

- vascular plants (freshwater and marine diatoms)

• Cyanobacteria Toxicity (850.4550) using TGAI

Aquatic non

- vascular plant toxicity data are only available for one ( i.e ., green algae) of four recommended in the OCSPP 850.4500/4550 test guidelines. Differential sensitivity may exist among aquatic non

- vascular plants, and as such, additional testing with the three other species is requested

.
Acute Oral Toxicity Testing with Passerines ( 850.2100 ) using TGAI

Acute oral toxicity te sting with passerines is not available. Passerines may exhibit differential toxicity compared to other birds. Given the mortality observed in the acute oral testing with bobwhite quail, testing with passerines is requested

.

Data needs for environmental fate assessment are:

Environmental Chemistry Methods (ECM) and Associated Independent Laboratory Validation (ILV) Reports:

• ECM & ILV report for analytical method in soil (850.6100 ) using TGAI

• ECM & ILV report for analytical method in water (850.6100 ) us ing TGAI

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### Antimicrobial Uses

These ecological effects data are being requested for the conventional uses, but are also needed for the antimicrobial uses.

Sediment (benth ic invertebrate) Toxicity Data:

• Freshwater Chronic Sediment Toxicity (non

- guideline ) using TGAI for one species of freshwater amphipod.

• Estuarine/marine Chronic Sediment Toxicity (non

- guideline) using TGAI for one species of estuarine/marine amphipod.

Aquatic Non

- vascular Plant Toxicity Data:

• Algal Toxicity (850.4500) usi ng TGAI for two species of non

- vascular plants (freshwater and marine diatoms)

• Cyanobacteria Toxicity (850.4550) using TGAI

These environmental fate data are expected to be required for the antimicrobial use patterns only:

• Guideline 850.3300: Activated s ludge respiration inhibition (ASRI)

• Guidelines 835.3110, 835.3220, 835.3240, 835.3280 (WWTP biodegradation studies) 1



### • Guideline 835.1110, Activated Sludge Sorption Isotherm (ASSI) 2



# 2

. Introduction

Tebuconazole ( Figure 1 ) is a triazole herbicide that has protective, curative, and systemic activity, and shows activity against rusts ( Puccinia spp.), powdery mildew , and fungi known to cause decay in wood and other materials . It provides protective activity by preventing compl etion of the infection process by direct inhibition of sterol synthesis. The mode of action of tebuconazole is based on inhibition of cytochrome P450 sterol 14α

- demethylase (P450 14D 

### ) activity, a key enzyme in the sterol biosynthetic pathway. It is rapidly absorbed by plants and translocated systemically in the young growing tissues. Some trade names for products containing tebuconazole include Lynx 45 WG, Lynx 2, Elite 45 DF, and Folicur 3.6F. End

- use products for conventional uses are formulated as water

- soluble granule s and a water

- soluble liquid concentrate, and can be applied by air, ground, or chemigation

. End

- use products for

1. T he results of the Activated Sludge Respiration Inhibition Test (ASRI) will determine which of these four biodegradation tests

is/are anticipated to be required.

• If the ASRI test EC50 is less than or equal to 20 mg/L, then either the (i) Biodegradation in Activated Sludge Study or (ii)

Simulation Test

- Aerobic Sewage Treatment: A. Activated Sludge Units or (iii) the Porous Pot Test is required. If the ASRI test EC50 is greater than 20 mg/L, then the registrant must conduct either: (i) Ready Biodegradability or (ii) a) Biodegradation in Activated Sludge or b) Simulation Test

- Aerobic Sewage Treatme nt: A. Activated Sludge Units or c) the Porous Pot Test.

• If the Ready Biodegradability study is conducted and passes, then no further testing is required. If, however, the antimicrob ial

fails the Ready Biodegradability study, then the a) Biodegradation in Activated Sludge or b) Simulation Test

- Aerobic Sewage Treatment: A. Activated Sludge Units, or c) the Porous Pot study is required.

2 The log Kow is greater than 3 (3.7), and ASSI data are required.

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### antimicrobial uses are formulated as powders and liquid concentrates for wood protection treatments (dip, spray, and pressuriz ed applications), buildings/ indoor products, forest products, and for use in a variety of sites as a materials preservative

.

Figure 1 : Chemical structure of tebuconazole (PC Code 128997)

Laboratory environmental fate studies have shown that there are several m inor degradate s (<10% formation) of tebuconazole . Fate data for these degradates suggest similar persistence as the parent tebuconazole , but they are more mobile than the parent

.

EFED and AD evaluated the most re cent ecologic al risk assessments for tebuconazole in association with the updated toxicity, exposure, and usage information to determine if sufficient data are available or if further updates are needed to support registration review. In addition, EFED and AD considered the latest Agency science policies and risk assessment methodologies.



# 3. Use Characterization

Conventional Uses

T ebuconazole is currently registered on many agricultural crops including some tree nuts, stone fruits, pome fruits, bea ns, and field crops like corn, soybeans, and wheat (including seed treatment use for wheat)

. It is also registered for use on golf course turf, ornamentals, and grasses grown for seed.

BEAD’s chemical profile includes both a summary of labeled uses as w ell as a summary of available reported usage data (Table 1) for the conventional pesticidal uses of tebuconazole

. The Screening Level Usage Analysis (SLUA ; April 29, 2015 ) and chemical profile reports conduc ted by BEAD showed highest usage of tebuconazole on peanuts and wheat with an annual average of 300,000 pounds active ingredient applied to each , based on available data from 200 4

— 201 3 (USEPA, 201 5 ). Other crops with higher usage include grapes, soybeans, cherries and corn

. Additionally, the average pe rcent crop treated with tebuconazole was 60% for garlic, 45% for peanuts, and 30% for cherries. N N

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### Table 1. Screening Level Estimates of Agricultural Uses (SLUA) of Tebuconazole (128997) Annual Average Percent Crop Treated Crop Lbs. A.I. Average Maximum

Almonds 2,000 5 10 Apples <500 <2.5 <2.5 Apricots <500 10 20 Asparagus <500 5 15 Barley 6,000 <2.5 <2.5
Beans, Green <500 <2.5 <2.5 Beans, Lima <500 <2.5 <2.5

Cantaloupes 1,000 <2.5 10

Cherries 10,000 30 45

Corn 10,000 <1 <2.5

Cotton 6,000 <1 <2.5

Cucumbers <500 <1 <2.5 Dry Beans/Peas 4,000 <2.5 5

Garlic 4,000 60 95 Grapes 30,000 25 35

Nectarines 1,000 10 20

Onions 1,000 5 5

Peaches 3,000 10 25

Peanuts 300,000 45 55

Pears <500 5 5

Pecans 9,000 5 15

Pistachios 1,000 5 10

Plums/Prunes <500 <2.5 5 Pumpkins <500 <2.5 <2.5 Soybeans 20,000 <1 <2.5 Squash <500 <2.5 5

Sweet Corn 3,000 <2.5 5

Walnuts <500 <1 <2.5

Watermelons 8,000 15 30

Wheat 300,000 5 15 Wheat (Seed treatment) 7,000 15 20

All numbers are rounded. <500: less than 500 pounds of active ingredients.

<2.5: less than 2.5 percent of crop is treated. <1: less than 1 percent of crop is treated. SLUA data sources include:

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### Table 1. Screening Level Estimates of Agricultural Uses (SLUA) of Tebuconazole (128997) Annual Average Percent Crop Treated Crop Lbs. A.I. Average Maximum USDA

- NASS (United States Department of Agriculture's National Agricultural Statistics Service) Private Pesticide Market Research California DPR (Department of Pesticide Regulation) These results reflect amalgamated data developed by the Agency and are releasable to the public.



### Figure 2 depicts the agricultural usage of tebu conazole on a national scale as compiled by the U.S. Geological Survey (USGS , 2012 ) 3



### . M ajor usage included use on wheat and soybeans with increases in use on corn in more recent years

.

3 http://water.usgs.gov/nawqa/pnsp/usage/maps/show_map.php?year=2012&map=TEBUCONAZOLE&hilo=L&disp= Tebuconazole (accessed October 27, 2015)

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### Figure 2 . National Agricultural Usage of Tebuconazole (USGS, 2012 )

The use profile and parameters to be utilized for EFED’s risk assessment include the terrestrial uses described in Table 2

. EFED will use application scenarios that result in maximum exposure scenarios for a given use for the risk assessment. It is noted that most uses do not indicate the maximum number of applications per year , but do report a maximum application use rate (annual or crop cycle). As such, EFED will divide the maximum application use rate by the single maximum application rate to determine the number of applications per year for modeling (using the minimum re

- application interval between applications). If there are situations where the label reports a maximum application use rate by crop cycle and does not identify a maximum yearl y use rate (based on Label Use Information Systems ( LUIS ) report, only golf courses and ornamental uses and some barley use labels report maximum annual rate) , EFED may use additional information to model more than one crop cycle in a year where appropriate.

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### Table 2. Tebuconazole Agricultural and Non

- agricultural Conventional Use Pattern s 1



### . Crop Maximum Single Application

Rate (lb

a.i./A) Number of Applications Maximum Application Rate (Annual or crop cycle) 2 Re

application

Interval Method of A pplication

Almonds 0.225 NS 0.9 7 Aerial, Ground Apple 0.1297 NS 0.4409 7 Ground Asparagus 0.169 3 0.507 14 Aerial, Ground Banana 0.09 NS 0.45 14 Aerial, Ground Barley 0.113 NS 0.113 NA Aerial, Ground Barley (seed treatment) 2E

- 5 lb /lb seed NA NA NA NA

Beans 0.169 NS 0.677 14 Aerial, Ground Beans, dry type 0.169 NS 0.338 14 Aerial, Ground Beets 0.203 NS 0.81 14 Aerial, Ground Brassica (head and stem vegetables) 0.112 NS 0.45 10 Aerial, Ground

Bulb vegetables 0.164 NS 0.656 10 Aerial, Ground Cherries 0.225 NS 1.35 7 Aerial, Ground Cherries 0.0921 NS 0.1828 7 Aerial, Ground Cherries (fruit cleansing) 0.0045 lb/lb fruit NS NS NS Ground

Corn (unspecified & sweet) 0.169 NS 0.677 7 Aerial, Ground

Corn (seed t reatment) 0.0002 lb/lb seed NA NA NA NA

Corn, field , pop &
sweet 0.0895 NS 0.358 7 Aerial, Ground

Cotton 0.225 NS 0.67 7 Aerial, Ground Cucurbits 0.225 NS 0.67 10 Aerial, Ground Filbert (hazelnut) 0.225 NS 0.9 7 Aerial, Ground Fruiting vegetables 0.225 NS 1.35 7 Aerial, Ground Garlic 0.169 NS 0.33 10 Aerial, Ground Garlic (in

- furrow) 0.57 NS 0.912 NS Ground

Golf course turf 1.3 (some have 0.72 w/max of 4.4) 6 4.4 NS Ground

Grapes 0.11 NS 0.9 7 Aerial, Ground Grasses grown for seed 0.225 NS 0.45 14 Aerial, Ground

Hops 0.225 NS 0.9 10 Aerial, Ground Leek 0.169 NS 0.67 10 Aerial, Ground Melon 0.22 NS 0.44 10 Ground Nectarine 0.225 NS 1.35 7 Aerial, Ground Oats , Wheat & Triticale (seed treatment) 2E

- 5 lb/lb seed NA NA NA NA

Okra 0.169 NS 0.67 14 Aerial, Ground Onion 0.169 NS 0.33 10 Aerial, Ground Onion (in

- furrow) 0.57 NS 0.91 NS Ground Onions, green 0.169 NS 0.67 10 Aerial, Ground

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### Table 2. Tebuconazole Agricultural and Non

- agricultural Conventional Use Pattern s 1



### . Crop Maximum Single Application

Rate (lb

a.i./A) Number of Applications Maximum Application Rate (Annual or crop cycle) 2 Re

application

Interval Method of A pplication

Ornamentals

– tree injection 1.5 lb / see footnote 3 NS NS When needed Injection

Ornamental grasses & Rye (seed
treatment ) 1.5E

- 5 lb/lb seed NA NA NA NA

Ornamentals 0.0013 lb /plant 4 NS 28 Aerial, Ground

Ornamentals & Roses 6.9 E

- 6 lb/ plant NS NS 7 Ground

Ornamentals 2.6 3 or 4 NS 28 Granular Ornamentals 0.28 4 1.1 14 Ground Ornamentals 0.84 4 3.36 14 Ground Peach 0.225 NS 1.35 7 Aerial, Ground Peanuts 0.203 NS 0.81 14 Aerial, Ground Pecan 0.22 5 NS 0.9 10 Aerial, Ground Pistachio 0.225 NS 0.9 10 Aerial, Ground Plantain 0.09 NS 0.45 14 Aerial, Ground Plum, Prune (fruit cleansing) 0.0002 lb/ lb fruit NS NS NS Ground

Pome fruits 0.225 NS 1.35 7 Aerial, Ground Shallot 0.169 NS 0.33 10 Aerial, Ground Shallot (in

- furrow) 0.57 NS 0.91 NS Ground Soybean 0.11 3 0.33 10 Aerial, Ground Stone fruit 0.225 NS 1.35 7 Aerial, Ground Subtropical/tropical fruit 0.169 8 1.35 10 Ground

Sunflower 0.169 NS 0.45 14 Aerial, Ground Tree nuts 0.225 NS 0.9 7 Aerial, Ground Turnip (greens) 0.203 NS 0.81 12 Aerial, Ground Wheat 0.11 NS 0.11 NA Aerial, Ground NS means “not stated” ; NA means “not applicable”

1 Based on BEAD LUIS report

2 Based on LUIS report, only golf courses, ornamentals and some barley labels specify maximum annual use rate ; all other uses appear to be based on maximum rate crop cycle. As such EFED may model more than 1 crop cycle per year, if appropriate, based on agr icultural practices for a crop.

3 If measuring the circumference, divide this number by six (6) to determine the number of capsules needed. If measuring the diameter, divide this number by 2 (two) to determine the number of capsules needed. If the number of capsules results in a fraction, round down to the lower whole number



### Antimicrobial Uses

There are 41 active labels for tebuconazole that contain antimicrobial uses. According to the labels, tebuconazole can be used for above

- ground and ground

- contact wood, plastics, glues, adhesives, and metalworking fluids. Te buconazole may be applied as an antisapstain treatment to wood and wood

- composite products including lumber, timbers (logs), landscape ties, fence boards and posts, decks, docks, walkways, and shingles. Application methods include pressure

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### treatment, dipping, and spraying, and one label (EPA Reg., No. 75341

- 14) includes remedial treatment of in

- service wood using brushes, trowels, and pumps. Two labels (EPA Reg. No. 39967

- 10 and 39967

- 13) also include uses in plastics, glues, adhesives, and metalworking fluids.



# 4. Conclusions from Previous Risk Assessments

4.1. Ecological Risk Assessments

Tebuconazole has been assesse d a number of times for new use risk assessments since the original registration in 19 93

. A couple of the more recent risk assessments include: evaluating tebuconazole use on home lawns, athletic fields, and sod in 2013 (DP405730+), and for use on fruiting vegetables (crop group 8) in 2009 (D362764).

EFED and AD have evaluated these assessments for tebuconazole in association with the current toxicity, exposure, and use information to determine if sufficient data are available and if further data/ updates are needed to support registration review. In t he previous assessments, risks were generally assessed using the parent compound only.

Based on the various past assessments which spanned a range of application rates and use patterns, risk tended to be greatest for freshwater fish ( chronic ), marine/estuarine invertebrates (acute and chronic ), birds (acute and chronic), mammals (chronic) , and terrestrial plants depending on the use patterns and application rates. A qualitative summary of previous risk concerns identified is provided in Table 3

.

Table 3 . Summary of Previous Risk Concerns Identified for Tebuconazole a

Exposure Basis Birds Mammals Terrestrial Plants Terrestrial Inverts. (honey bee hazard) Fish Aquatic Inverts Aquatic Plants Persistence

Acute Yes No Yes No b No Yes c No Yes Chronic Yes Yes Yes Yes

a. At least one LOC has been exceeded in previous assessments b. L ack of t oxicity data

c. Estuarine/marine invertebrates only



### 4 .2. Drinking Water Assessments

The most recent drinking water assessment (DWA) for t ebu conazole (parent only) for an increase of maximum use rate of tebuconazole on golf course turf was conducted in 20 11

. Tebu conazole estimated groundwater concentrations were calculated using the Tier I SCIGROW (Screening Concentration In Ground Water) model. The m aximum concentrations of tebu conazole in surface
water (use on turf) were estimated to be 92.3 

### μg/L for the 1

- in

- 10

- year annual peak, and 72.4 μg/L for the 1

- in

- 10

- year annual average. The maximum peak concentration of tebuconazole in

### Page 15 of 56 

### groundwater was estim ated to be 1.56 μg/L. No surface water monitoring data were available for tebuconazole.

4.3. Clean Water Act Programs

Tebuconazole is not identified as a cause of impairment for any water bodies listed as impaired under section 303(d) of the Clean Water Act. No Total Maximum Daily Load (TMDL) c riteria have been developed for tebuconazole

. No aquatic life criteria have been established for tebuconazole, although a quatic life benchmarks are available for tebuconazole (Table 4) ( http:/www2.epa.gov/pesticide

- sci ence

- and

- assessing

- pesticide

- risks/aquatic

- life

- benchmarks

pesticide

- registration )

.

Table 4. OPP Aquatic Life Benchmarks (μg /L) (freshwater) Fish Invertebrates Nonvascular Plants Vascular Plants Acute Chronic Acute Chronic Acute Acute 1135 12 1440 120 1450 151.5



# 5

. Environmental Fate and Transport

Tebuconazole is persistent in soil (aerobic metabolism T 1/2 

### = 796 days) and moderately to slightly mobile in soil (adsorption K OC 

### s range from 906 to 1251 ml/g). Tebuconazole has little potent ial to reach ground water, except in soils of high sand and low organic matter content. During a runoff event, tebuconazole adsorbed onto the soil particles could enter adjacent bodies of surface water via sediment in runoff. During an application, tebuc onazole may drift off

- site into the surface water. T ebuconazole will not appreciably volatilize from soil or water, based on its vapor pressure and water solubility limit

Tebuconazole is resistant to hydrolysis (T 1/2 

### >> 28 days or stable at pH 5, 7, and 9), aqueous and soil photodegradation [T 1/2 

### = stable (extrapolated T1/2 = 590 days and 192.5 days, respectively)], and soil metabolism (aerobic metabolism T1/2 = 796 days). Terrestrial field dissipation half

lives varied from about 1.6 to 10 months. Tebuconazole dissipated with an extrapolated half

- life of 301 days from loamy sand turf plots at one site in Glenmark, New York, when LYNX 25DF fungicide was surface broadcasted three times at 1. 40 lb a.i./ A and once at 0. 68 lb a.i./ A (applications separated by one

- month). A supplemental study on bare ground in Florida showed leaching of tebuconazole to a lower horizon. In sand soil of Vero Beach, FL (sand = 92%, silt = 0.4%, clay = 7.6%, and organic matter = 1%) tebuconazol e was detected up to 0.12 ppm in the depth of 6 to 12 inches 30 days after surface application of 1.5 lb. a.i./ A (lower depths were not sampled, MRID [Master Record Identification Number ] 40700963). In addition, tebuconazole has a low potential for bioacc umulation in fish tissues , with a log Kow of 3.7 and fish BCFs of 25, 228, and 99 L/kg for edible, nonedible, and whole fish tissues, respectively

. Depuration was

### Page 16 of 56 

### rapid, with 99

- 100% of the accumulated 14 

### C residues eliminated from the fish tissues by day 1 5 of the depuration period.

For the antimicrobial uses, the low K ow 

### (Log P) of 3.7 in MRID 44108304 also indicates that sorption will be a significant route of dissipation, and most residues in the environment will be associated with soil and sediment. In a W astewater Treatment Plant (WWTP) , the primary route of dissipation is expected to be sorption with limited volatility because of the low vapor pressure (1.3 x 10

- 8 

### mm Hg) in MRID 44108304 and the Henry’s Law constant of 2 x 10

- 10 

### atm m 3 

### mol

- 1 

### (calcul ated). In a modified AWPA E11

- 12 4 

### study using submerged blocks in water , leaching from treated wood increases with increasing temperature (5

- 25 o 

### C) and decreases with increasing pH (pH 5.5

- 8.5), with maximum release rates of 0.78

- 2.87 μg/cm 2 

### /day (MRID 468 41601) 5 

### . In an AWPA E11

- 12 study (MRID 48901607, unreviewed), the average leaching of tebuconazole was 6.7 % (no leaching rates calculated). This study will be reviewed during registration review.

A selection of t ebuconazole environmental fate and tran sport properties is summarized in Table 5 below.

Table 5

. Physical Chemical and Environmental Fate Properties of Tebuconazole.

Parameter Value Source Selected Physical/Chemical Parameters
Chemical Structure

CH 3

N N

N C

H 2 C H 3 O H

C H 3 C H 2 C H 2 Cl

Empirical Formula C 16 H 22 ClN 3 O http://pubchem.ncbi.nlm.nih.gov/compound/Teb uconazole#section=Names

- and

- Identifiers

IUAPC Name (RS)

- 1

- p

- chlorophenyl

- 4,4

- dimethyl

- 3

- (1H

- 1,2,4

- triazol

- 1

- ylmethyl)pentan

- 3

- ol http://pubchem.ncbi.nlm.nih.gov/compound/Teb uconazole#section=Names

- and

- Identifiers

CAS No. 107534

- 96

- 3 http://pubchem.ncbi.nlm.nih.gov/compound/Teb uconazole#section=Names

- and

- Identifiers PC Code No. 128997
SMILES string: CC(C)(C)C(CCC1=CC=C(C=C1)Cl)(C N2C=NC=N2)O http://pubchem.ncbi.nlm.nih.gov/compound/Teb uconazole#section=Names

- and

- Identifiers Molecular Weight 307.82 g/mol http://pubchem.ncbi.nlm.nih.gov/compound/Teb uconazole#section=Names

- and

- Identifiers Formulation Water Soluble Granule and Water Soluble Liquid Concentrate

4 American Wood Protection Association, http: //www.awpa.com/standards/

5 U.S. EPA, Milano, T., August 30, 2006 review

### Page 17 of 56 

### Table 5

. Physical Chemical and Environmental Fate Properties of Tebuconazole.

Parameter Value Source

Vapor pressure 1.3X10

- 8 (torr) Tomlin CDS, ed; The e

- Pesticide Manual: a world compendium. Tebuconazole 13th ed. PC CD

- ROM, Version 3.0, 2003

- 04. Surrey, UK: British Crop Protection Council, (2003) Aqueous solubility 36 mg/L at 20 deg C Tomlin CDS, ed; The e

- Pesticide Manual: a world compendium. Tebuconazole 13th ed. PC CD

- ROM, Version 3.0, 2003

- 04. Surrey, UK: British Crop Protection Council, (2003) Dissociation constants (pKa ) 5.0 FootPrint Pesticide Properties Database @http://sitem.herts.ac.uk/aeru/iupac/Re ports/610.htm Henry’s Law Constant 1.4X10

- 10 atm

- cu m/mole calculated

log Kow 3.7 Tomlin CDS, ed; The e

- Pesticide Manual: a world compendium. Tebuconazole. 13th ed. British Crop Protection Council, (2003) 

### Persistence Hydrolysis half

life (pH 5, 7, 9) s table MRID 40700957

Aqueous photolysis half

life Stable MRID 40700958

Soil Photolysis half

- life 192.5 days MRID 40700958

Aerobic soil metabolism half

life 796 days MRID 40700959

Anaerobic soil metabolism half

life 1063 days MRID 40700959

Anaerobic aquatic metabolism half

life >365 MRID 48707403 (supplemental)

Aerobic aquatic metabolism half

life (total system) >52 MRID 48707405 (supplemental)



### Mobility Adsorption/ desorption K OC : 1025, 911, 1251, and 906 mL/g MRID 40995922



### Field Dissipation

### Page 18 of 56 Terrestri al field dissipation half

life 1.6

- 10 months MRID 40700962 41717406 44108306 44108307

- 09 44108310

- 17 44666101

- 06 44699501 45046501 45359901 

### Fish Bioconcentration Fish bioconcentration factors (BCF); depuration rate BCFs (L/kg) 25 (edible) 228 (nonedible) 99 (whole fish tissues)

Depuration 99

- 100% eliminated by day 15 of the depuration period. MRID 40995905 40995906 40995907



### 5.1

. Transformation Products

Based on the environmental fate data, carbon dioxide is the only ma j or degradate of tebuconazole. Additional minor (<10% of applied activity) organic degradates were identified in the soil and aquatic fate studies. These include hydroxyphenyl tebuconazole, dechlorinated tebuconazole, and deschloro hydroxy tebuconazole (dechlorinated alcohol of tebuconazole) . Below, Table 6 a presents identified degradates and their maximum percent of applied radioactivity. Table 6 b presents fate d ata and summa ry information regarding parent degradation; other extracted products were not identified, but were formed in limited (<8%) quantities

. Across the available environmental fate studies, formation of degradates was minor because tebuconazole was slow to degrade

. The transformation product, 1,2,4

- triazole was not detected in any study for tebuconazole (this degradate is considered a major degradate for other conazoles)

. For some conazoles, this degradate has been shown to be more or equally toxi c than the parent conazole for certain taxa ( i.e. , birds), therefore, the presence or absence of this product was noted for tebuconazole. Formation of 1,2,4

- triazole in the environment is uncertain because tebuconazole degraded so slowly during the environmental fate studies that formation of 1,2,4

- triazole, which is formed by other conazoles, was not observed. In the environment, however, 1,2,4

- triazole may form over longer time scales.

### Page 19 of 56 

### Table 6 a . Tebu conazole and Its Environmental Transformation Products f rom Aquatic Metabolism Studies

. Code Name/ Synonym Chemical Name Chemical Structure Study Type MRID Maximum %AR (day) Final %AR (study length) PARENT
Tebuconazole (HWG 1608) IUPAC: ( RS )

- 1

- p

chlorophenyl

- 4,4

- dimethyl

3

- (1 H

- 1,2,4

- triazol

- 1

- ylmethyl)pentan

- 3

- ol

CAS: α

- [2

- (4

- Chlorophenyl)ethyl]

- α

- (1,1

- dimethylethyl)

- 1 H

1,2,4

- triazole

- 1

- ethanol

CAS No.: 107534

- 96

- 3

Formula: C 16 H 22 ClN 3 O MW: 307.8 g/mol SMILES: c1cc(Cl)ccc1CCC(O)(C(C) (C)C)Cn2ncnc2 CH 3

N N

N C

H 2 C H 3 O H

C H 3 C H 2 C H 2 Cl 835.4300 Aerobic aquatic metabolism 48707405 Gravel pit water:sediment 1 94.5% (7 d) 55.8% (364 d)

Drainage ditch water:sediment 1 91.3% (7 d) 67.3% (364 d)

835.4400 Anaerobic

aquatic metabolism 48707403 Pond water/sandy loam 107.0% (28 d) 91.1% (365 d)

MAJOR (>10%) TRANSFORMATION PRODUCTS
Carbon dioxide IUPAC: Carbon dioxide

Formula: CO 2 MW: 44 g/mol SMILES: C(=O)=O C O O 835.4300 Aerobic aquatic metabolism 48707405 Gravel pit water:sediment 1 20.9% (364 d) 20.9% (364 d)

Drainage ditch water:sediment 1 10.0% (364 d) 10.0% (364 d)

835.4400 Anaerobic

aquatic metabolism 48707403 Pond water/sandy loam 0.46% (272 d) 2 0.18% (365 d) 2

Unextractable residues

NA NA 835.4300 Aerobic aquatic metabolism 48707405 Gravel pit water:sediment 1 14.0% (364 d) 14.0% (364 d)

Drainage ditch water:sediment 1 18.9% (364 d) 18.9% (364 d)

### Page 20 of 56 Code Name/ Synonym Chemical Name Chemical Structure Study Type MRID Maximum %AR (day) Final %AR (study length) MINOR (<10%) TRANSFORMATION PRODUCTS Hydroxyphenyl tebuconazole (K237, HWG 2606) IUPAC: 5

- (5

- Hydroxy

- 4

- chlorophenyl)

- 2,2

- dimethyl

- 3

- (1H

- 1,2,4

- triazol

- 1

- ylmethyl)pentan

3

- ol

Formula: C 16 H 22 ClN 3 O 2 MW: 323.8 g/mol SMILES: CC(C)(C)C(CCc1ccc(c(c1) O)Cl)(Cn2cncn2)O CH 3 O H

Cl O H

N N

N C

H 2 C H 3

C H 3 C H 2 C H 2 835.4400 Anaerobic

aquatic metabolism 48707403 Pond water/sandy loam 1.17% (272 d) 0.51% (365 d)

Dechlorinated tebuconazole (K239) IUPAC: 5

- Phenyl

- 2,2

- dimethyl

- 3

- (1H

- 1,2,4

- triazol

- 1

- ylmethyl)pentan

3

- ol

Formula: C 16 H 23 ClN 3 O MW: 273.37 g/mol SMILES: CC(C)(C)C(CCc1ccccc1)( Cn2cncn2)O CH 3 O H

N N

N C

H 2 C H 3

C H 3 C H 2 C H 2 835.4400 Anaerobic

aquatic metabolism 48707403 Pond water/sandy loam 0.71% (272 d) 0.38% (365 d)

Deschloro hydroxy tebuconazole (dechlorinated alcohol of tebuconazole) IUPAC: 2,2

- Dimethyl

- 5

- phenyl

- 3

- (1,2,4

- triazol

- 1

- ylmethyl)pentane

- 1,3

- diol

Formula: C 16 H 23 N 3 O 2 MW: 289.37 g/mol SMILES: CC(C)(CO)C(CCc1ccccc1) (Cn2cncn2)O CH 3 C H 2 O H

C H 2 C H 2

N

N N

C H 2 O H C H 3

835.4400 Anaerobic

aquatic metabolism 48707403 Pond water/sandy loam 0.29% (90 d) 0.05% (365 d)

A AR means “applied radioactivity”. MW means “molecular weight”. 1 Sediments were characterized using the W. German BBA particle size classification system, but soil texture classifications were not reported. 2 Total volatiles are presumed to be carbon dioxide. Results from NaOH, ethylene glycol and H2SO4 traps were not separately r eported.

### Page 21 of 56 

### Table 6 b. Soil Metabolism Studies and Degradation Summary Information for Tebuconazole

Study Percent Distribution of Recovered Radioactivity
Parent Degradate/transformation Product 1 ,2 

### Unextractable Residues Study ID

Aerobic Soil (phenyl 14C labeled) 98.3

- 82% from Day 0

- 112; 78.8% @ 6 months; 67.4% at 12 months 0.4

- 0.9 % from Day 0

- 112; 0.9& 2.6% @ 6 months; 1.1 & 2.1% @ 12 months 0.8

- 16.2% from Day 0

- 112; 17% @ 6 months; 29.1% @ 12 months MRID 40700959

Aerobic Soil (triazole 14C labeled) 98.1

- 85.0% from Day 0

- 58 0.3

- 0.6% from Day 0

- 58 2 

### 1.3

- 14.5% from Day 0

- 58 MRID 40700959

Anaerobic Soil 73.1

- 70.3% from Day 0

- 60 0.4

- 2.2% from Day 0

- 60 4.1

- 7.5% (in flood water) from Day 0

- 60 19.5

- 23.4% from Day 0

- 60 MRID 40700959

Soil Photolysis 96

- 86% from Day 0

- 35 <1

- 3% from Day 0

- 60 2.6

- 5.5% from Day 0

- 60 MRID 40700958 Aqueous Photolysis 94

- 95% from Day 0

- 30 None observed None observed MRID 40700958

1 Extracted product(s) not identified (unknown)

2 1,2,4

- triazole not detected

### Page 22 of 56 

# 6. Receptors

Tables 7 through 9 provide a summary of the taxonomic groups tested to characterize the potential acute and chro nic ecological effects of tebuconazole

. In addition, the table s provide a preliminary overview of the potent ial acute toxicity of tebuconazole by providing the a cute toxicity classifications. The available toxicity data for tebuconazole are presented in Appendix A

.

6.1

. Aquatic Organisms

Invertebrates, Acute . The estuarine/marine invertebrate, mysid shrimp ( Americamysis bahia ), was the most sensitive spe cies with a 96

- hr LC 50 

### value of 0.49 mg a.i./L (MRID 40995902).

Invertebrates , Chronic . Chronic toxicity data are available for freshwater and estuarine/marine fish and invertebrates. In the freshwater invertebrate toxicity study, using Daph nia magna , the NOAEC value was 0.120 mg a.i./L based on reductions in adult body length and reproduction (LOAEC=0.230 mg a.i./L; MRID 40700915). In this study, it is noted that measured test solution concentrations increased during the study which may hav e been related to an increase in stock solution concentration. The reported effects are based on measured concentrations.

A NOAEC of 0.035 mg a.i./L (LOAEC=0.061 mg a.i./L) was reported in the mysid shrimp ( A

. bahia ) chronic toxicity study based on a d ecrease in reproduction (MRID 42038201). Undissolved test material was noted in the diluter system and in the test chambers of the highest test concentration ( 0. 200 m g a.i./L) , and efforts to centrifuge or filter test solution samples prior to analysis we re not reported. Given that there was undissolved material observed in the diluter system which prepared all the test solutions, there is uncertainty in the actual dissolved test concentrations in this study. Test solutions were approximately 50% of nomin al at the beginning of the study, and measured concentrations generally gradually increased over the duration of the study.

Given the uncertainty in exposure concentration in the mysid shrimp chronic toxicity study, an acute to chronic ratio (ACR) using the Daphnia magna toxicity data were used to calculate a chronic toxicity value for mysid shrimp. Using the ACR (28) and the acute mysid shrimp toxicity value (0.49 mg a.i./L), a chronic value of 0.018 mg a.i./L was derived, which is similar to the
repor ted NOAEC in the mysid chronic study. Although there is uncertainty in the exposure concentrations, additional chronic estuarine/marine toxicity data are not requested, as the NOAEC value reported in the study along with other lines of evidence (e.g., ACR calculations, chronic toxicity data from other conazoles) will be used to evaluate potential risk to estuarine/marine invertebrates.

Fish, Acute

. Tebuconazole is classified as moderately acutely toxic to fish and freshwater invertebrates, and highly toxic to estuarine/marine invertebrates. Acute toxicity data were available for three species of fish , with the most sensitive 96

- hr LC 50 

### value reporte d as 2.27 mg a.i./L for rainbow trout, Oncorhynchus mykiss (MRID 46919204). This study was conducted under static

- renewal conditions (24

- hr renewals) in which only Day 0 test solutions were measured. It

### Page 23 of 56 

### was reported that test solutions were measured in the rangefinder study with Day 0 samples ranging from 97

- 100% of nominal and 24

- hr samples ranging from 90

- 102% of the initial Day 0 concentrations, suggesting that test solution may have been stable during the 24

- hr renewal period. In another rainbow trout acute toxicity study conducted under flow

- through conditions, the reported 96

- hr LC 50 

### value is 4.4 mg a.i./L (MRID 40700911)

.
Fish, Chronic

. Several chronic toxicity studies are available for both freshwater and estuarine/marine fish. I n a rainbow tro ut ( O

. mykiss ) fish early life

- stage study, there were no effects on hatch

, but survival and growth were significantly reduced at ≥0.025 mg a.i. /L (NOAEC of 0.012 mg a.i./L; MRID 40700914)

. In another fish early life

- stage toxicity study with sheepshead minnows ( Cyprinodon variegatus )

, there were no effects on hatch or survival, but wet weight was significantly reduced at ≥0.048 mg a.i. /L and length was reduced at 0.099 mg a.i. /L (NOAEC of 0.022 mg a.i./L; MRID 42038202)

. No reproductive effects were noted in a sheep s head minnow life cycle study (MRID 43009601)

, but parental survival was significantly reduced (day 58 & 177) at the highest treatment tested (0.197 mg a.i. /L), and parental body length was significantly reduced at the mid

- high treatment (0 .097 mg/L; highest treatment not analyzed due to mortality). Additionally, offspring length was significantly reduced at the mid and mid

- high concentrations (≥0.044 mg a.i. /L , compared to solvent control ) with an overall study NOAEC of 0.019 mg a.i./L

. In this study, it is noted that salinity and temperature were variable throughout study, and there was low parental survival (24%) in one solvent control replicate at the end of the study (56% survival overall in solvent control) . Also, it was reported that the offspring embryos were treated with 10% formalin to prevent disease.

In a fathead minnow ( Pimephales promelas ) sexual development study (MRID 48109802) , there was no effect on hatch but survival was significantly reduced at ≥0.045 mg a.i. /L with si gnificant reduction in female growth (body weight and length) at 0.022 mg a.i. /L (NOAEC of 0.011 mg a.i. /L) . There was no difference in sex ratio after 54 days of exposure . Increases (not statistically analyzed) in s pinal deformities were observed at ≥0.02 2 mg a.i. /L ; histopathological effect on the liver and pancreas were observed at 0.011 mg a.i. /L, and effects on gonadal histopathology was observed at 0.011 and 0.022 mg a.i. /L for females and males, respectively

. Finally, in the screening

- level fish short

- term reproduction assay (FSTRA) with fathead minnows, there were no statistically significant effect s on survival, growth, or reproduction (fecundity) up to 0.0195 mg a.i./L compared to the control (MRID 48688301). A lterations in non

- apical endpoint s included: alterations in female gonad histology

, and statistically significant decreases in plasma vitellogenin as well as decreases in gonadal weight (relative to body weight) in males and females at 0.0195 mg a.i./L compared to the control. It is note d that in the Endocrine Disruptor Screening Program (EDSP) weight of evidence analysis, a medaka extended one

- generation reproduction assay (MEOGRT) was recommended for tebuconazole (see EDSP section).

In a published study by Yu et al. (2013), zebrafish embryos were exposed to tebuconazole at concentrations of 0, 1, 2, or 4 mg/L from shortly after spawning to 120 h post

- fertilization

. There were no significant effects on hatching, malformations, or survival.

### Page 24 of 56 

### Amphibians

. In the screening

- level amphibian metamorphosis assay (AMA) with Xenopus laevis tadpoles, a s ignificant delay of median Nieuwkoop

- Faber (NF) developmental stage by one stage was observed at Day 7 at all treatment groups (0.017, 0.067 & 0.341 mg/L), and significant delays at Day 21 at the m id (by one stage) and high (by 5 stages) concentrations

. Additionally, decreases in snout

- vent length and body weight were observed at the high concentration on both Day 7 and 21 (MRID 48673701).

Aquatic Plants

. Several green algae toxicity studies are available for tebuconazole with the lowest EC 50 

### value of 1.45 mg a.i./L, based on cell counts, and a NOAEC value of 0.32 mg a.i./L (MRID 40995908). However, toxicity testing for the other three aquatic non

- vascular species are not available ( i.e. , freshwater and marine diatoms, and cyanobacteria). Given that there may be differential sensitivity among the four species and the observed toxicity in the aquatic vascular plant study , toxicity testing with these additional species is recommended to su pport both conventional and antimicrobial uses of tebuconazole. The 14

- d EC 50 

### , based on frond density, for the aquatic vascular plant, Lemna gibba , was reported as 0.151 mg a.i./L (EC 05 

### =0.034 mg a.i./L; MRID 44246901).

Benthic Invertebrates

. A 28

- d sedi ment toxicity study (spiked sediment) with the benthic invertebrate Chironomus riparius , evaluating survival and emergence and development rates is available (MRID 48707402). The most sensitive endpoint was development rate with reported NOAECs of 15.7 mg a.i./kg in sediment and 0.481 and 0.404 mg a.i./L in pore and overlying water, respectively. Given tebuconazole’s observed persistence in terrestrial and aquatic environments and it s potential to bind to soil/sediment, chronic toxicity testing with sedimen t

dwelling (benthic) invertebrates is recommended. While the above study did evaluate longer

- term survival and development, it did not evaluate reproduction which was reported as a sensitive endpoint in both the freshwater and estuarine/marine chronic inv ertebrate studies. Additionally, effects on larval body length were reported for the freshwater benthic harpacticoid copepod, Attheyella crassa (Turresson et al . 2007). As such, chronic benthic toxicity testing with tebuconazole which includes evaluating reproduction is recommended for both freshwater (two species, an amphipod and midge) and estuarine/marine invertebrates (one species, an amphipod) to support conventional uses of tebuconazole

. For antimicrobials, studies conducted for one species of fresh water amphipod and one species of estuarine/marine amphipod will satisfy this requirement.

Mesocosm Study

. A mesocosm study which simulated turf applications of 0.68 lb a.i./A at two week intervals was applied 4 times by subsurface injection was conducted to determine if the use of this product could result in chronic effects to fish and aquatic invertebrate communities (MRID 42760101) . A review of the study found that tebuconazole altered juvenile fish growth and survival at the highest test con centrations (24.4 to 149 μg/L in water). These alterations in fish populations altered the community structure with regards to other species (plant and invertebrates).

### Page 25 of 56 Table 7 . Summary of the Most Sensitive Endpoints from Aquatic Toxicity Studies for Tebuconazole

Taxonomic

Group 

### Study Type Tested Species Toxicity Value (95% conf. intervals ) (mg a.i./L) Acute Toxicity Classification Source (Study Classification) Comments

Freshwater fish 1 Acute Rainbow trout ( Oncorhynchus mykiss ) 96

- Hr LC 50 = 2.27 (1.59

- 3.31) Slope: 3.25 Moderately toxic 46919204 ( Supplemental )

Chronic Fathead minnow ( Pimephales promelas ) NOAEC = 0.011 NA 48109802 (Supplemental) 2 Based on reduction in female growth

Freshwater invertebrates Acute Water Flea ( Daphnia magna ) 48

- Hr E C 50 = 2.88 (2.1

- 3.9) Slope = 2.38 Moderately toxic 46919205 ( Acceptable )

Chronic Water Flea ( Daphnia magna ) 21

- d NOAEC = 0.120 NA 40700915 (Acceptable) Based on reduction in parental body length and reproduction

Estuarine/ marine fish Acute Sheepshead minnow ( Cyprinodon variegatus ) 96

- hr LC50 = 5.9 (5.3

- 7.0) Slope: NA Moderately toxic 40995904 (Acceptable)

Chronic NOAEC = 0.019 NA 43009601 (Supplemental) Based on reduction in offspring body length

Estuarine/ marine invertebrates Acute Mysid shrimp ( Americamysis bahia ) 96

- hr LC50 = 0.49 (0.33

- 0.66) Slope: 2.3 Moderately toxic 48587107 (Acceptable)

Chronic NOAEC = 0.035 NA 42038201 (Supplemental) 3 Based on reduction in reproduction

Aquatic plants and algae Vascular Duckweed ( Lemna gibba ) E C 50 = 0.151 (0.139

- 0.165) EC 05 = 0.034 N/A 44246901 ( A cceptable)

Non

vascular Green Algae ( Scenedesmus subspicatus ) E C 50 = 1.45 ( NA ) NOAEC 0.32 N/A 4 0995908 (Supplemental )

1 Freshwater fish may be surrogates for aquatic

- phase amphibians.

2 Although this species is different than most acutely sensitive species, the rainbow trout chronic NOAEC value is 0.012 mg a.i./L, which is similar to fathead minnow NOAEC.

3 Downgraded during review for problem formulation due to uncertainty in exposure concentrations from observation of undissolved test material



### Formulation Toxicity

. Additionally, acute toxicity studies using a formulation which contained tebuconazole are available for fish, Daphnia , and aquatic plants ( SC 400 ( 200+200 ) G ; 17.1% fluopyram and 17.5

- 17.8% tebuconazole) . However, in these studies, only the other active ingredient (fluopyram, PC 080302) was measured in which re coveries were generally around nominal concentrations . As such, the toxicity values reported in Table 6 are based on nominal tebuconazole concentrations. The results of these studies

, adjusted to percent tebuconazole

, are similar or higher (less toxic) co mpared to toxicity values using TGAI.

### Page 26 of 56 

### Table 8 . Acute Formulation Toxicity Data with Tebuconazole for Aquatic Species Species Acute Toxicity Value (mg product/L) Acute Toxicity Value (mg tebuconazole/L) Study ID

Daphnia magna 48

- hr EC50 = 56.9 48

- hr EC50 = 9.96 1 

### 47567611 Rainbow trout 96

- hr LC50 = 21.7 96

- hr LC50 = 3.8 1 

### 47567612 Lemna gibba 7

- d EC50 = 4.3 7

- d EC50 = 0.76 2 

### 47567616 Lemna gibba 7

- d EC50 = 0.73 7

- d EC50 = 0.13 2 

### 47567617 Green algae 72

- hr EC50 = 11 72

- hr EC50 = 1.9 1 

### 47567618

1 

### Based on 17. 5 % tebuconazole

2 

### Based on 17.8% tebuconazole



### 6.2

. Terrestrial Organisms

Birds, Acute

. Tebuconazole is slightly toxic to birds on an acute oral basis and practically non

toxic on a dietary basis, and it is slightly toxic to mammals on an acute oral exposure basis ( Table 7 ). In the acute oral bobwhite quail study (MRID 40700950 ) with tebuconazole

, the acute LD 50 

### value was 1,988 mg/kg

- bw with decreased body weight observed at doses of ≥720 mg/kg

- bw (no effect 432 mg/kg

- bw). In the subacute dietary studies with mallard duck, no mortalit y was observed up to 4816 mg a.i./kg

- diet , however , reduced body weight gain was observed 4816 mg a.i./kg

- diet (MRID 40700907 ). In the sub

- acute study with bobwhite quail, while the LC 50 

### value was >5,000 mg.kg

- diet, mortalities were observed at ≥2,500 mg/kg

- diet with decreased body weight gains at all treatments (≥325 mg/kg

- diet; MRID 40700908).

No acute passerine bird toxicological data are available. Given the observed mortality in the acute oral and dietar y studies with bobwhite quail and sublethal effects of reduced body weight gain in both the mallard and bobwhite subacute dietary studies, an avian acute oral study using a passerine species is requested to support conventional uses. Passerine exposure is not expected to result from antimicrobial uses, and AD does not anticipate the need for a passerine study to support registration review.

Birds, Chronic

. In the avian one

- generation reproduction toxicity studies (two quail and two duck), dietary admini stration of tebuconazole resulted in reproductive effects in two of the studies. In the first bobwhite quail study, no treatment

- related reproductive effects or clinical signs were noted at dietary levels up to the highest concentration tested, 73.5 mg/kg

- diet (MRID 40700910)

. H owever, in the second bobwhite quail study conducted at higher concentrations (MRID 41624201)

, significant reproducti ve effects were observed at the high dose (290 mg/kg

- diet )

, includ ing a reduction of 33% in the number of eggs laid , 11% reduction in normal hatchlings, as well as a 37% decrease in offspring survival and 7

- 11% decreases in offspring body weight

. In this study, significant reductions in offspring body weight (4

- 6%) were also reported at all treatment group s ( NOAEC < 15 6 mg/kg

- diet ). I n the first mallard duck study, no treatment

- related reproductive effects or clinical signs were noted at dietary levels up to the highest concentration tested, 76 mg/kg

- diet ( MRID 40700909) . H owever, in the second mallard duck study ( MRI D 41818301)

, significant decreases in the number of hatchlings per hen were reported at the high

### Page 27 of 56 

### concentration of 611 mg/kg

- diet; however, no significant effects on the number of hatchling s per viable embryos were determined at any treatment concentration

. Considering the results of these studies collectively and the magnitude of effects observed at 156 mg/kg

- diet, a NOAEC value of 73.5 mg/kg

- diet will be used in the assessment.

Mammals

. The m ammalian acute toxicity LD 50 

### value is 1615 mg / kg bw ( MRID 42090006 ). I n a 2

- generation reproductive toxicity study in rats, t he lowest NOAEL was reported as 300 mg a.i. /kg

- diet , based on decreased maternal and pup body weights and pup viability; the LOAEL was 1000 mg a.i. / kg

- diet ( MRID 40700946 )

.
Honey Bees

. Ac ute contact or oral toxicity data to bees for tebuconazole TGAI were not submitted to the Agency

. A contact LD 50 

### value of 176 μg a.i./bee has been reported. 6 

### However, acute oral and contact toxicity data for adult honeybees are available for two formulation s containing tebuconazole . In the first study (SC 400 (200+200) G) acute oral and contact LD 50 

### value s of 62.5 and > 200 μg product /bee (10.9 and >35 μg tebuconazole/bee) were reported , respectively (MRID 47567613 )

. However, as in the acute aquat ic toxicity studies with this formulation, tebuconazole concentrations were not measured. In another formulation study with tebuconazole (17%), acute contact and oral LD 50 

### values were 7.6 and 1.5 μg a.i./bee, respectively (MRID 48844515). While a definiti ve toxicity value was obtained in the second formulation study, given that there was another active ingredient present and there are no submitted data with tebuconazole only , it is unknown how this other a.i. (flupyradifurone) influenced the overall toxici ty and what may be attributed to tebuconazole

. C hronic toxicity data are not available for adult bees n or are acute or chronic data available for larval bees

. Data on pollinator toxicity is required to sufficiently evaluate risk to pollinators (USEPA 2014 a )

. Therefore, a cute and chronic toxicity data for both adult and larvae honeybees using TGAI are recommended to support conventional uses

. Antimicrobial uses of tebuconazole are expected to present far less exposure risk to honeybees than conventional uses, and then only to adult honeybees. Because tebuconazole is not expected to be applied to wood used to construct honey bee enclosures, tebu conazole poses no appreciable chronic risk to honeybees from antimicrobial uses . Therefore

, only an adult acute contact study is necessary and sufficient to support antimicrobial uses. AD will use the most sensitive data endpoints available at the time of risk assessment to assess the risk posed to honeybees by tebuconazole. However, tebuconazole endpoints extrapolated from formulation toxicity studies are sufficient to characterize the acute risk posed by antimicrobial uses of tebuconazole to adult honeybe es at this time. No further honeybee studies are expected to be required to support antimicrobial uses at this time.

Other Terrestrial Invertebrates

. Other terrestrial invertebrate toxicity data with the SC 400 G formulation are available for earthworms , parasitoid wasps, ladybird beetles, green lacewing, and predatory mites. For these studies, in many cases, there were no effects up to the highest concentration tested (3L product/ha). For earthworms, a 14

- d LC 50 

### value of 875 mg product/kg dry weight (15 3 mg tebuconazole/kg) was reported.

6 As reported in Bayer Report 99753, 1987, cited in Section 3 new use risk assessment D333331, 332261 and 332171. The DER for MRID 48844515 report an LD50 value of > 175 μg/bee for tebuconazole.

### Page 28 of 56 

### Terrestrial Plants

.

Tier I (limit concentration) t errestrial p lant seedling emergence and vegetative vigor data are available for tebuconazole

. While the IC 25 

### values were greater than the limit concentration, NOAEC values were le ss than the limit concentration , except for dicot seedling emergence

. As such, additional testing is requested in an effort to obtain definitive terrestrial plant toxicity values

. While testing using a dose

- response test design (Tier II) is preferred, Tier I testing may be acceptable if the requirements as outlined in OCSPP 850.4100 and 850.4150 for all tested species are met, keeping in mind the concentration for which the current no NOAEC value is set at ( i.e

., testing would likely need to incorporate a rate lower than the current limit concentration). It is noted that the limit concentration (0.4 lb a.i./A) is slightly above estimated environmental concentrations (EECs) using the single maximum ground application rate for golf course turf at 1.3 lb a.i./A ( maximum EEC=0.27 lb a.i./A; TerrPlant v1.2.2 ; Appendix C ). However, while the EECs are lower when modeling one application, EECs using multiple applications may be used in the future.

As mentioned, Tier I (limit test) toxicity studies are available for monocot and dicot seedling
emergence as well as for monocot and dicot vegetative vigor. In the first Tier I seedling emergence study with monocots and the Tier I vegetative vigor study with monocots and dicots, the IC 25 

### values were great er than the limit concentration ( single concentration tested at 0.4 lb a.i./A ; 45821301 

### ). However, there were significant differences between the limit concentration and control for both monocots and dicots (NOAEC<0.4 lb a.i./A)

.

In additional Tier 1 ve getative vigor and seedling emergence studies (MRID 4757615 and 47567614) , the IC 25 

### values for monocots were > 0.18 lb tebuconazole/A (1L product/ha; SC 400 (200+200) G; 17.8% tebuconazole ) . H owever, for monocots in the vegetative vigor study, a significant 14% difference between the limit concentration and control was observed for oats (NOAEC<0.18 lb a.i./A) . For dicots, the IC 25 

### values were < 0.18 lb a.i./A in the seedling emergence study for four dicot species (cucumber was most sensitive with 4 1% inhibition) , and

were > 0.18 lb a.i./A in the vegetative vigor study.

The results of the seedling emergence Tier I stud y showed that dicots were more sensitiv e than
monocots , with dicots exhibiting a >25% effect

. As such, Tier II seedling emergence tes ting was conducted for dicots. The I C 25 

### value for the most sensitive dicot species (tomato) from the Tier II seedling emergence study was 0.045 lb a.i./A (IC 05 

### = 0.016 lb a.i./A; MRID 47299201). Since definitive IC25 and NOAEC values are available, addit ional testing with dicots for seedling emergence is not recommended

. Antimicrobial uses of tebuconazole are expected to present less exposure to terrestrial plants than are conventional uses. No further terrestrial plant toxicity studies are required to support antimicrobial uses of tebuconazole.

### Page 29 of 56 

### Table 9 . Summary of the Most Sensitive Endpoints from Terrestrial Toxicity Studies for Tebuconazole
Taxonomic

Group Study Type 

### Tested Species Toxicity Value Acute Toxicity Classification Source (Study Classification) Comments

Birds 1 Acute

Bobwhite quail ( Colinus. virginianus) 21

- D LD 50 1988 mg a.i./kg

- bw Slightly Toxic 40700905 (Acceptable) Reduced body weight at 720 ppm (no effect at 432).

Sub

- acute dietary 8

- D LC 50 ≥ 5000 mg a.i./kg

- diet Practically non

toxic 40700907 (Acceptable) Mortality at ≥2500 ppm; reduced body weight gain at all concentrations (no effect <325 ppm)

Chronic NOAEC = 73.5 mg a.i./kg

- diet N/A 40700910 & 41624201 (Acceptable) Offspring body weight reductions at 156 ppm

Mammals Acute Oral Mouse ( Mus musculus ) 2 LD 50 1615 mg a.i./kg

bw Slightly toxic 42090006 (Acceptable)

Acute Inhalation Laboratory rat ( Rattus norvegicus ) LD 50 > 0.371 mg/L NA 40700922 (Acceptable); dosing to aerosol for 4 hours with a 14

- d observation period

Chronic 2

- gen NOAEC = 300 mg ai/kg

- diet LOAEC = 1000 mg ai/kg

- diet N/A 40700946 (Acceptable) Based on decreased maternal and pup body weight and decreased pup viability [NOAEC = 15 mg/kg/day; LOAEC = 50 mg/kg

day]

Insects Acute
contact

Honey bee ( Apis mellifera L. ) No data available for TGAI (formulation toxicity data available for acute oral and contact adult honeybees) Acute Oral

Chronic 10

- Day

Larval Emergence

Terrestrial plants Seedling Emergence Dicot

– tomato ( Solanum lycopersicum ) 21

- D IC 25 = 0. 045 lbs ai/acre IC 05 = 0. 016 lbs ai/acre N/A 47299201 ( Supplemental )

### Page 30 of 56 

### Table 9 . Summary of the Most Sensitive Endpoints from Terrestrial Toxicity Studies for Tebuconazole
Taxonomic

Group Study Type 

### Tested Species Toxicity Value Acute Toxicity Classification Source (Study Classification) Comments

Monocot

– wheat ( Triticum aestivum ) 21

- D IC 25 > 0.4 lbs ai/acre NOAEC = <0.4 lbs ae/acre N/A 45821301 (Supplemental)

Vegetative vigor Dicot

— Cucumber ( Daucus carota ) 21

- D IC 25 > 0.4 lbs ai/acre NOAEC = <0.4 lbs ae/acre N/A

45821301 ( Supplemental )

( Monocot

– wheat ( Triticum aestivum ) 21

- D IC 25 > 0.4 lbs ai/acre NOAEC = <0.4 lbs ae/acre N/A

1 Birds represent surrogates for terrestrial

- phase amphibians and reptiles.

2 The acute oral toxicity LD 50 value with rats is 3352 mg/kg

- bw (females) MRID 40700917



### 6.3 Incidents

A review of the Ecological Incident Information System (EIIS, version 2.1) and the Avian Monitoring Information System (AIMS) was completed on October 16 , 2015

. There are 17 reported incident s in EIIS for tebuconazole ( Table 10 )

. No ecological incidents involving tebuconazole were identified in AIMS

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

- B), ‘minor plant’ (P

- B), and ‘other non

- target’ (ONT) incidents

. ‘Other non

- target’ incidents include reports of adverse effects to insects and other terrestrial invertebrates. For tebuconazole , registrants have reported 2 minor fish and wildlife, 43 minor plant, and 0 other non

- target incidents. Incident databases will be reviewed again at the time of the risk assessment.

Table 10 . Summary of Ecological Incidents Associated with Tebuconazole as Reported In EIIS Incident Type Legality Certainty All Possible Probable High Probable Fish and aquatic invertebrates Registered Use or Unknown 1 1

-- --

Known Misuse 1

-- -- 1 All 2 1

-- 1

### Page 31 of 56 

### Table 10 . Summary of Ecological Incidents Associated with Tebuconazole as Reported In EIIS Incident Type Legality Certainty All Possible Probable High Probable Plants Registered Use or Unknown 11 11

-- --

Known Misuse 3 1 2

-- All 14 12 2

--


### One aquatic incident (incident # 1007892

- 003) was reported in compliance with 6(a)2 regulations about a fish kill in Minnesota on June 25, 1998. An undetermined number of fathead minnow were killed along a long stretch of a creek adjacent to two wheat fields that had been treated (one by aircraft) with Folicur. This incident was ra ted as "possible" because of the moderate acute toxicity of tebuconazole to fish. In addition, there were no data with regard to application parameter details

. Regarding one of the i ncidents to terrestrial plants, one was the result of a "misuse" situatio n (incident # I01 5 152

- 001) where a formulator added tebuconazole to a 790

- gallon lot of a mixture of quintozene, thiabendazol, and captan on March 12, 2004. This created a formulation of an unregistered end

- use product for a soybean seed treatment which was used by about 1 0 commercial seed treating companies in IL, IN, OH, MI, and LA. Stunted growth was observed on May 21, 2004, and growers were consequently instructed to destroy their crops. Damage to a bout 1

, 950 acres of soybeans from the use of tebucon azole in conju n ction with unknown a djuvant(s) resulted in plant stress and yellowing (incident # I0 16595

- 031, I0016595

- 032). Another incident with soybean occurred when damage was caused by high heat and the application of tebuconazole (incident # I01 16737

- 021). Damage to spring wheat resulted from a reported "off label use" of tebuconazole (incident # I0 16662

- 021, I01662

- 022). Leaf and head malformation were observed.

One incident (I021587

- 001, 2009) reported mortality to adult honeybees from 320 hi ves in Utah. However, the legality of the use was unknown and was rated as unlikely for tebuconazole.

Overall, the incident data that are available indicate that exposure pathways for tebuconazole are complete and that exposure levels are sufficient to result in field

- observable effects to non

- target terrestrial plants.



# 7

. Exposure Pathways of Concern

The environmental fate properties and conventional use patterns of tebuconazole indicate runoff and
spray drift of tebuconazole applications represent p otential transport mechanisms of tebuconazole to aquatic and terrestrial organisms. The exposure pathways for antimicrobial uses are included in Section 8.2 below.

Drinking Water

. The d rinking water exposure pathway for birds and mammals w as screened using the SIP (Screening Imbibition Program) screening method

. The inhalation exposure pathway is typically evaluated using the STIR (Screening Tool for Inhalation Risk) screening method. SIP and STIR are described in detail at: http://www2.epa.gov/pesticide

- science

- and

- assessing

-

### Page 32 of 56 

### pesticide

- risks/models

- pesticide

- risk

- assessment#terrestrial

. T he drinking water path way alone for tebuconazole was found to not be an exposure pathway of potential concern on an acute or chronic basis for mammals or acute basis for birds, but did suggest a potential pathway of concern on a chronic basis for bir d s. SIP results are present ed in Appendix B

. This pathway will be explored further in the registration review risk assessment for tebuconazole.

Inhalation

. The inhalation exposure pathway was not considered likely to be an exposure pathway of potential concern for mammals or for vapor

- phase for birds. However, it did suggest a potential concern for droplet inhalation for birds ( Appendix B ). In this analysis, a non

- definitive acute LD 50 

### inhalation value for rats was used as a definitive value (no mortality occurred in study). The trigger for potential concern is a ratio greater than 0.1, and the output for droplet inhalation for birds was 0.13. Given the use of the non

- definitive value, and that the ratio was just above 0.1, additional inhalation toxicity data with birds is no t requested at this time

. 

# 8

. Analysis Plan

**8.1 Stressors of Concern** 

8.1.1 Ecological Risk

No major degradates (>10% formation) were identified in either the soil or aquatic metabolism studies. Minor degradates were identified in the anaerobic aquatic metabolism stud y which are similar in structure to parent tebuconazole. Given the similarity in structure to parent tebuconazole, they may have similar toxicity profiles as the parent structure and could be considered f or inclusion in exposure analyses using a total toxic residue (TTR) approach. However, given that the maximum formation rate for the three products ranged from 0.29

- 1.17%, inclusion of these products is anticipated to have no appreciable impact on resultin g estimated environmental concentrations. Therefore, t he stressor of ecological concern for terrestrial and aquatic organisms for the ecological risk assessment will only be the parent compound, tebuconazole

.

8.1.2 Drinking Water

The Health Effects Division ( HED ) Metabolism Committee ( MARC ) determined that the residue of concern in drinking water is tebuconazole per se (Memo, 06/07/2001, W. Donovan, et al., D275136). The refore, the residue that will be assessed in drinking water from surface and grou nd
water is tebuconazole only

.

Estimated drinking water concentrations (EDWC) for tebuconazole uses for use in the human health risk assessment will be modeled during registration review , due to the introduction of new (PRZM

- GW) or revised (SWCC) models since the last drinking water exposure assessment.

### Page 33 of 56 

## 8.2 **Measures of Exposure**

8.2.1 Modeling of Ecological Exposure

Conventional Uses

EFED will use standard available models to evaluate potential exposures to aquatic and terrestrial organisms as described at http://www2.epa.gov/pesticide

- science

- and

- assessing

- pesticide

risks/models

- pesticide

- risk

- assessment

.

Antimi crobial Uses

Based on the summary of registered uses of tebuconazole and the chemical, physical, and environmental fate properties in Table 4, the Agency has developed conceptual model diagrams for exposure of ecological organisms to tebuconazole.

The Ag ency has created conceptual models for potential routes of environmental exposure which are included in “Conceptual Models for Environmental Exposure Pathways of Antimicrobial Pesticides,” (EPA

- HQ

- OPP

- 2014

- 0638

- 0002), found in the docket at http://www.regulations.gov/#!documentDetail;D=EPA

- HQ

- OPP

- 2014

- 0638

- 0002 . The Agency does not consider the wall board or treated adhesives in packaging uses to create environment al exposure because the treated materials are not anticipated to come into contact with water. Use sites and corresponding figures of conceptual model diagrams are as follows:

• Wood preservation (slides 29

- 31)

• Metalworking fluids (slide 18)

• Glues and adhesives (slide 17)

• Plastics (slide 15)

S creening Level Down

- the

- Drain Analysis for Antimicrobial Uses of Tebuconazole

Chemicals that are released down

- the

- drain can typically take from a few to several hours to reach wastewater treatment plant intakes following their discharge and from several hours to roughly a day following their discharge down

- the

- drain to subsequently be discharged from wastewater treatment plants to surface water. Data on WWTP dissipation have not been submitted for tebuconazole, however, the primary routes of dissipation are expected to be partitioning to sludge with some subsequent outflow in efflue nt.

For the m etalworking fluid use , t he Down

- the

- Drain (DtD) module of E

- FAST (Exposure and Fate Assessment Screening Tool) will be used to determine the potential for aquatic organisms downstream of domestic wastewater treatment plants (WWTPs) that rec eive discharges from application of tebuconazole to be exposed to tebuconazole from the point of application to the point of discharge following wastewater treatment

. The results of the DtD module runs are expressed as number of days of exceedance of conc entrations of concern (COC) for aquatic organisms. In order to complete the down the drain assessment, the following studies will need to be submitted by the registrant: 850.3300

- Modified Activated Sludge Respiration inhibition;

### Page 34 of 56 

### 835.3110

- Ready Biodeg radable Test or one of three Biodegradable in Activated Sludge Simulati o n Tests (835.3220, 835.3280, 835.3240); and 835.1110

- Activated Sludge Sorption Isotherm.

8.2.2 Modeling of Drinking Water in Human Dietary Risk Assessment

The drinking water as sessments conducted to support future human health risk assessments of tebuconazole will incorporate modeling of tebuconazole in surface and ground water. Since the last drinking water assessment was conducted, EFED has updated its surface and ground water models, the drinking water modeling input parameters, and the percent crop ped area (PCA) guidelines. For all modeling, input parameters are selected according to the current input guidance , and where in question

, a conservative approach is taken in the selection of half

- lives. Descriptions of all executable versions of current models for drinking water exposure can be obtained from the following URL link: http://www2.epa.gov/pesticide

- science

- and

- assessing

pesticide

- risks/models

- pesticide

- risk

- assessment#aquatic

.

8.2.3 Available Water Quality Monitoring Data

EFED will consider all ground and surface water monitoring data available, and will conduct a comprehensive evaluation of the data for the risk assessment. The data that may be considered include the United States Geological Survey (USGS) National Water

- Quality Assessment (NAWQA) Program monitoring data

, the EPA STOR ET database, and any State data available at the time of risk assessment

.


## 8.3 **Measures of Effect**

Toxicity data presented in Section 6 of this problem formulation will be used to calculate risk quotients. Any additional information submitted by the registrant or found in the open literature prior to conduct of the risk assessment will be considered. The open literature studies are iden tified using EPA’s ECOTOXicology database ( ECOTOX) (USEPA, 2007), which employs a literature search engine for locating chemical toxicity data for aquatic life, terrestrial plants, and wildlife. The evaluation of both sources of data can also provide insi ght into the direct and indirect effects of pesticides on biotic communities from loss of species that are sensitive to the chemicals and from changes in structure and functional characteristics of the affected communities.



# 9. Endangered Species Assessme nt

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

### Page 35 of 56 

### to Endangered and Threatened Species from Pesticides

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

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

, Interim Approaches for National

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

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

. 

# 10. Endocrine Disruptor Screening Program

Tebuconazole was included in the first group of chemicals issued an order to conduct Tier 1 ED SP testing f or which EPA has received all of the required Tier 1 assay data. The Agency has reviewed all of the assay data received for the appropriate List 1 chemicals and the conclusions of those reviews are available at http://www2.epa.gov/ingredients

- used

- pesticide

- products/endocrine

disruptor

- screening

- program

- tier

- 1

- assessments

. For additional information the EDSP program, visit http://www2.epa.gov/endocrine

- disruption

. Based on the weight of evidence findings, f or wildlife

, the Medaka Extended One

- Generation Reproduction Test (MEOGRT) was recommended.

### Page 36 of 56 

# 11

. Preliminary Identification of Data Gaps

**11.1 Environmental Fate** 

Table 1 1 identifies environmental fate studies by MRID that offer data for each guideline requirement, as well as study classifications and whether or not further data are needed in order to support risk assessment. Analytical methods in soil and water and associa ted independent laboratory validations are needed with LOQs below toxicological levels of concern. No other environmental fate data are needed.

Table 1 1 : Environmental Fate Data Requirements for Tebuconazole

Guideline # Data Requirement MRID #s Study Classification Are data needed to conduct risk assessment? Justification and Assumptions EPA will Make in Absence of Data

835.2120 Hydrolysis 40700957 Acceptable No NA

835.2240 Photodegradation in Water 40700958
45344601 Acceptable Unacceptable No NA

835.2410 Photodegradation on Soil 40700958 Acceptable No NA

835.4100 Aerobic Soil Metabolism 40700959
45344601 Acceptable
Invalid No NA

835.4200 Anaerobic Soil Metabolism 40700959 Acceptable No NA

835.4400 Anaerobic Aquatic Metabolism 48707403 Supplemental No NA

835.4300 Aerobic Aquatic Metabolism 48707405 Supplemental No NA

835.1240 835.1230 Leaching

Adsorption/Desor ption 40995922 40700960
40700961 Acceptable Acceptable Unacceptable No NA

835.1410 Laboratory Volatility N/A N/A N/A NA

835.8100 Field Volatility N/A N/A N/A NA

### Page 37 of 56 Table 1 1 : Environmental Fate Data Requirements for Tebuconazole

Guideline # Data Requirement MRID #s Study Classification Are data needed to conduct risk assessment? Justification and Assumptions EPA will Make in Absence of Data

835.6100 Terrestrial Field Dissipation 40700962 41717406 44108306 44108307

- 09 44108310

- 17 44666101

- 06 44699501 45046501 45359901 Supplemental No NA

850.6100 Analytical method in water No data

N/A Yes An a nalytical method in water and an associated independent laboratory validation report are requested for use by state lead agencies.

850.6100 Analytical method in soil No data

N/A Yes An analytical method in soil and an associated independent laboratory validation report are requested for use by state lead agencies.

850.1730 Fish Bioconcentration 40995905

- 07 Supplemental No NA

850.3300 Activated sludge respiration inhibition (ASRI) No data N/A Yes Data are needed to conduct a “down the drain” assessment for the antimicrobial uses.

Only one biodegradation

study is needed. The appropriate study is determined by the results of the ASRI study. 835.3110 835.3220 835.3240 835.3280 WWTP biodegradation studies No data

N/A Yes

835.1110 Activated Sludge Sorption Isotherm No data N/A Yes



## 11. **2 Effects** 

Tables 12 and 1 3 identify ecological effects studies by MRID that offer data for each guideline requirement, as well as study classifications and whether or not further data are needed in order to support risk assessment.

### Page 38 of 56 

### Table 1 2 . Available E cological E ffects D ata for A quatic O rganisms E xposed to T ebuconazole and R emaining D ata G aps.

OCSPP Guideline Data Requirement Submitted Studies (MRID) Study Classification Are data needed to conduct risk assessment for conventional

uses ? Are data need ed to support antimi crobial uses? Justification and Assumptions EPA will Make in Absence of Data

850.1010 Freshwater invertebrate acute toxicity 40700913 46919205 47567611 Acceptable Acceptable Supplemental No No NA

850.1025 850.1035 850.1045 850.1055 Saltwater invertebrate acute toxicity 40995902 40995903 48587107 Acceptable Acceptable Acceptable No No NA

850.1075 Freshwater fish acute toxicity 40700911 40700912 46919204 47567612 Acceptable Acceptable Supplemental Supplemental No No NA

850.1075 Saltwater fish acute toxicity 40995904 Acceptable No No NA

850.1300 Freshwater invertebrate life cycle 40700915 Acceptable No No NA

850.1350 Saltwater invertebrates life cycle 42038201 Supplemental No No NA

850.1400 Freshwater fish early

- life stage 40700914 40700915 48109802 Acceptable Acceptable Supplemental No No NA

850.1400 Saltwater fish early

- life stage 42038202 Acceptable No No NA

850.1500 Fish life cycle 43009601 Supplemental No No NA

850.1735 Whole Sediment Acute Toxicity Invertebrates, Freshwater No data N/A No No Given tebuconazole’s persistence, requesting chronic study below in lieu of acute study

850.1740 Whole Sediment Acute Toxicity Invertebrates, Saltwater No data N/A No No Given tebuconazole’s persistence, requesting chronic study below in lieu of acute study

### Page 39 of 56 

### Table 1 2 . Available E cological E ffects D ata for A quatic O rganisms E xposed to T ebuconazole and R emaining D ata G aps.

OCSPP Guideline Data Requirement Submitted Studies (MRID) Study Classification Are data needed to conduct risk assessment for conventional

uses ? Are data need ed to support antimi crobial uses? Justification and Assumptions EPA will Make in Absence of Data

Non

guideline Whole Sediment Chronic Toxicity Invertebrates, Freshwater No data N/A Yes Yes Tebuconazole is persistent and may partition to soil/sediment and therefore, sediment organisms may be exposed. The exposure should be from treated

s ediment and not overlying water, and the study should evaluate reproduction

Non

guideline Whole Sediment Chronic Toxicity Invertebrates, Saltwater No data N/A Yes Yes Tebuconazole is persistent and may partition to soil/sediment and therefore, sediment organisms may be exposed. The exposure should be from treated

s ediment and not overlying water, and the study should evaluate reproduction

850.4400 Aquatic plant Toxicity Test using Lemna
spp. 44246901 4 7567616 47567617 Acceptable Acceptable Acceptable No No No

850.4500 Algal toxicity 40995908 42905401 44079601 47567618 Supplemental Acceptable Acceptable Supplemental Yes Yes Only toxicity data for green algae are available. Toxicity testing for two other algal taxa are required per 40 CFR Part 158 (i.e., freshwater and marine diatoms). Additionally, given the persistence of tebuconazole in

### Page 40 of 56 

### Table 1 2 . Available E cological E ffects D ata for A quatic O rganisms E xposed to T ebuconazole and R emaining D ata G aps.

OCSPP Guideline Data Requirement Submitted Studies (MRID) Study Classification Are data needed to conduct risk assessment for conventional

uses ? Are data need ed to support antimi crobial uses? Justification and Assumptions EPA will Make in Absence of Data

aquatic environments, there is a po tential for
exposure.

850.4550 Cyanobacteria No data N/A Yes Yes Only toxicity data for green algae are available. Toxicity testing for cyanobacteria are required per 40 CFR Part 158. Additionally, given the persistence of tebuconazole in aquatic enviro nments, there is a potential for
exposure.

### Page 41 of 56 

### Table 1 3 . Available Ecological Effects Data for Terrestrial Organisms Exposed to Tebuconazole and Remaining Data Gaps.

OCSPP Guideline Data Requirement Submitted Studies (MRID) Study Classifications Are data needed for risk assessment for conventional

uses ? Are data needed to support antimicrobial uses? Justification and Assumptions EPA will Make in Absence of Data

850.2100 Avian oral toxicity 40700905 Acceptable Yes No An acute oral study with a passerine species has not been submitted to the
agency. Given observed mortality in the bobwhite quail acute oral and acute dietary study, a study with a passerine species is requested to support conventional uses.

850.2200 Av ian dietary toxicity 40700907 40700908 Acceptable Acceptable No No NA

850.2300 Avian reproduction 40700909 40700910 41624201 41818301 Acceptable Acceptable Acceptable Supplemental No No NA

Non

guideline Avian inhalation No Data N/A No No Data have not been submitted to fulfill this guideline. A data gap was not identified as these data are not necessary for risk assessment at this time.

### Page 42 of 56 

### Table 1 3 . Available Ecological Effects Data for Terrestrial Organisms Exposed to Tebuconazole and Remaining Data Gaps.

OCSPP Guideline Data Requirement Submitted Studies (MRID) Study Classifications Are data needed for risk assessment for conventional

uses ? Are data needed to support antimicrobial uses? Justification and Assumptions EPA will Make in Absence of Data

850.3020 Honey bee
acute contact toxicity 47567613 48844515 Supplemental Acceptable Yes No The available data

were conducted with a formulated product and d ata have not been subm itted to fulfill this guideline for TGAI. These data with TGAI are needed to evaluate acute risk to pollinators for conventional use risk assessment. This study is not needed to support antimic robial uses.

850.3030 Honey bee residue on foliage No Data N/A Yes No Data have not been submitted to fulfill this guideline. The conduct of this study is contingent upon the results of 850.3020 for conventional uses. This study is not needed to support antimicrobial uses.

Non

guideline Honey bee adult acute oral toxicity 47567613 48844515 Supplemental Acceptable Yes No The available data were conducted with a formulated product and d ata have not been subm itted to fulfill this guideline for TGAI. These data with TGAI are needed to evaluate acute risk to pollinators for conventional use risk assessment s

. This study is not needed to support antimicrobial uses.

### Page 43 of 56 

### Table 1 3 . Available Ecological Effects Data for Terrestrial Organisms Exposed to Tebuconazole and Remaining Data Gaps.

OCSPP Guideline Data Requirement Submitted Studies (MRID) Study Classifications Are data needed for risk assessment for conventional

uses ? Are data needed to support antimicrobial uses? Justification and Assumptions EPA will Make in Absence of Data

Non

guideline Honey bee adult chronic oral toxicity No Data N/A Yes No Chronic (repeated dose) data is needed on adult honey bees to evaluate chronic risk to pollinators for the risk
assessment for conventional uses

. Although EPA has not developed a guideline for this study, guidance for a 10

- day oral toxicity study is currently in development by OECD. A protocol should be submitted prior to study initiation. This study is not needed to support antimicrobial uses.

Non

guideline Honey bee larval acute oral toxicity No Data N/A Yes No In addition to the adult honey bee data gaps

### Page 44 of 56 

### Table 1 3 . Available Ecological Effects Data for Terrestrial Organisms Exposed to Tebuconazole and Remaining Data Gaps.

OCSPP Guideline Data Requirement Submitted Studies (MRID) Study Classifications Are data needed for risk assessment for conventional

uses ? Are data needed to support antimicrobial uses? Justification and Assumptions EPA will Make in Absence of Data

Non

guideline Honey bee larval chronic oral toxicity No Data N/A Yes No identified above, data is needed for the additional honey bee life stage of larvae to complete the risk assessment for pollinators. Although EPA has not developed a guideline for these studies, OECD TG237 may b e used to assess acute oral effects on larvae. Chronic (repeat dose) study guidance for assessing chronic oral toxicity to honey bee larvae is currently in development by OECD. A protocol should be submitted prior to study initiation. This study is not

n eeded to support antimicrobial uses.

### Page 45 of 56 

### Table 1 3 . Available Ecological Effects Data for Terrestrial Organisms Exposed to Tebuconazole and Remaining Data Gaps.

OCSPP Guideline Data Requirement Submitted Studies (MRID) Study Classifications Are data needed for risk assessment for conventional

uses ? Are data needed to support antimicrobial uses? Justification and Assumptions EPA will Make in Absence of Data

850.3040 Field testing for pollinators No Data N/A Yes No Data have not been submitted to fulfill this guideline. Results from lower tier studies should inform the conduct of the field test to address remaining uncertainties. Pending the results of lower tier studies (adult honey bee acute oral, chronic adult honey bee, acute and chronic larval), a field testing study may not be needed to

c omplete the risk assessment for pollinators for conventional uses

. A protocol should be submitted prior to test initiation. This study is not needed to support antimicrobial uses.

### Page 46 of 56 

### Table 1 3 . Available Ecological Effects Data for Terrestrial Organisms Exposed to Tebuconazole and Remaining Data Gaps.

OCSPP Guideline Data Requirement Submitted Studies (MRID) Study Classifications Are data needed for risk assessment for conventional

uses ? Are data needed to support antimicrobial uses? Justification and Assumptions EPA will Make in Absence of Data

850.4100 Seedling Emergence and Seedling Growth 45821301 47299201 45821302 45280001 47567601 Supplemental Supplemental Supplemental Supplemental Supplemental Yes 1 No Definitive NOAEC values
were not determined,
t herefore, additional Tier II testing is requested for monocots to support conventional uses

. A definitive IC25 and NOAEC value is available for dicot seedling
emergence, so additional testing with dicots is not requested. This study is not needed to support antimicrobial uses.

850.4150 Vegetative Vigor 45821301 47567615 Supplemental Supplemental Yes 1 No Definitive NOAEC values
were not determined,
t herefore, additional Tier II testing is requested for monocots and dicots to support conventional uses

. This study is not needed to support antimicrobial uses.

1 

### It is noted that while Tier II (dose

- response) testing is preferred, if Tier I testing criteria as outlined in OCSPP 850.4100 and 850.4150 are met for al l tested species, then Tier II testing may not be necessary.

### Page 47 of 56 

# 12. References

MRID 44108304. Fritz, R. (1988) Adsorption/Desorption of FOLICUR (HWG 1608) on Soil: Lab Project Number: 1310222/1: 100101. Unpublished study prepared by Bayer Corp. 48 p.

MRID 46841601. Brooks, K. (2005) Copper and Tebuconazole Loss Rates from Southern Pine Treated to a Retention of 0 .246 Pounds Per Cubic Foot with Copper Azole Type B (CA

- B) Preservative. Unpublished study prepared by Aquatic Environmental Sciences and Battelle Marine Sciences Lab. 332 p.

MRID 48901607. Muchow, T. (2012) AWPA E11 Leachability Testing. Project Number: OSMOSE/2012/21, 10/0504. Unpublished study prepared by Timber Products Inspection. 9p.

United Nations Food and Agriculture Organization. Assessing soil contamination : A reference manual. http://www.fao.org/docrep/003/x2570e/x2570e06.htm

U.S. EPA. August 30, 2006. Review of Leaching Data For Southern Pine Treated With Copper Azole T ype B (CA

- B) Preservative . Milano, T. D 330143

.
USEPA, 201 5 . BEAD Chemical Profile for Registration Revi ew: Tebuconazole ( 128997 ). Office of Pesticides Program, Biological and Economic Analysis Division. Arlington, VA.

USEPA, 2014 a . Guidance for Assessing Pesticide Risks to Bees. Office of Pesticide Programs, USEPA, Washington D.C. Health Canada Pest Ma nagement Regulatory Agency, Ottawa, ON, Canada. California Department of Pesticide Regulation, Sacramento, CA. June 23, 2014.

U.S. EPA, Office of Pesticide Programs, Antimicrobial Division, Risk Assessment and Science Support Branch. August 4, 2014. Conceptual Models for Environmental Exposure Pathways of Antimicrobial Pesticides. EPA

- HQ

- OPP

- 2014

- 0638. http://www.regulations.gov/#!documentDetail;D=EPA

- HQ

- OPP

- 2014

- 0638

- 0002

Yu, L, Chen, M, Liu, Y, et al. (2013) Thyroid endocrine disruption in zebrafish larvae following exposure to hex aconazole and tebuconazole. Aquat. Toxicol. 138 : 35

- 42.

### Page 48 of 56 

## Appendix A. Toxicity Data for Tebuconazole

Table A.1 Summary of Aquatic Toxicity Studies for Tebuconazole (TGAI)

Taxonomic

Group Study Type Tested Species Toxicity Value (95% conf. intervals) (mg a.i./L) Acute Toxicity Classification Source (Study Classification) Comments

Freshwater fish 1 Acute Rainbow trout ( Oncorhynchus mykiss ) 96

- Hr LC 50 = 2.27 (1.59

- 3.31) Slope: 3.25 Moderately toxic 46919204 (Supplemental) ; Sublethal effects observed at ≥0.95 ppm (no effects at 0.46 ppm)

96

- Hr LC 50 = 4.4 ( 3.8

- 5.2 ) Slope: 6.4 Moderately toxic 40700911 ( Acceptable ) ; Sublethal effects observed at ≥2.5 ppm (no effects at 1.5 ppm)

Bluegill ( Lepomis macrochirus ) 96

- Hr LC 50 = 5.7 ( 4.2

- 6.4 ) Slope: NA Moderately toxic 40700912 (Acceptable) Sublethal effects observed at all test concentrations ≥ 1.4
ppm

Chronic Fathead minnow ( Pimephales promelas ) NOAEC = 0.011 NA 48109802 (Supplemental) Based on reduction in female growth (fish sexual development test); LOAEC 0.022 ppm

Rainbow trout ( Oncorhynchus mykiss ) NOAEC = 0.0 12 NA 40700914 ( Acceptable ) Based on reduction larval hatch (early life

- stage study); LOAEC 0.025 ppm

Fathead minnow ( Pimephales promelas ) No effect = 0.019 NA 4 8688301 ( Satisfies ) No effect on survival, growth reproduction at highest conc. Tested (fish short

- term reproduction assay)

Freshwater invertebrates Acute

Water Flea ( Daphnia magna ) 48

- Hr EC 50 = 2.88 (2.1

- 3.9) Slope = 2.38 Moderately toxic 46919205 (Acceptable) ; no effects observed at 0.49 ppm

48

- Hr EC 50 = 4.0 ( 3.4

- 4.8 ) Slope = 3.8 Moderately toxic 46919205 (Acceptable) ; no effects observed at 0.74 ppm

Chronic 21

- d NOAEC = 0.120 NA 40700915 (Acceptable) Based on reduction in parental body length and reproduction ; LOAEC = 0.230 ppm

Estuarine/ marine fish Acute Sheepshead minnow ( Cyprinodon variegatus ) 96

- hr LC50 = 5.9 (5.3

- 7.0) Slope: NA Moderately toxic 40995904 (Acceptable) sublethal effects observed at all test concentrations ≥ 1.2
ppm

Chronic NOAEC = 0.019 NA 43009601 (Supplemental) Based on reduction in offspring body length (fish life

- cycle test); LOAEC=0.044 ppm

### Page 49 of 56 NOAEC = 0.0 22 NA 4 2038202 ( Acceptable ) Based on reduction in body weight (early life

- stage test); LOAEC=0.048 ppm

Estuarine/ marine invertebrates Acute Mysid shrimp ( Americamysis bahia ) 96

- hr LC50 = 0.49 (0.33

- 0.66) Slope: 2.3 Moderately toxic 48587107 (Acceptable) sublethal effects observed at all test concentrations ≥ 0.3
ppm

Chronic NOAEC = 0.035 NA 42038201 (Supplemental) Based on reduction in reproduction (life

- cycle test)

Acute Eastern Oyster ( Crassostrea virginica ) 96

- hr E C50 = 2.7 ( 2.5

- 3.0 ) Slope: NA Moderately toxic 48587107 (Acceptable) ; no effects observed at 1.7 ppm

Aquatic plants and algae Vascular Duckweed ( Lemna gibba ) EC 50 = 0.151 (0.139

- 0.165) EC 05 =0.034 N/A 44246901 (Acceptable)

Non

vascular Green Algae ( Selenastrum capricornutum ) EC 50 = 2.73 ( 2.33

- 3.19 ) NOAEC = 1.24 N/A 42905401 ( Acceptable )

Green Algae ( Selenastrum capricornutum ) EC 50 = 2.83 ( 2.41

- 3.02 ) NOAEC =1.19 N/A 44079601 ( Acceptable )

Green Algae ( Scenedesmus subspicatus ) EC 50 = 1.45 (NA) NOAEC 0.32 N/A 40995908 (Supplemental)

1 Freshwater fish may be surrogates for aquatic

- phase amphibians.



### Table A.2. Acute Formulation Toxicity Data (SC 400 (200+200) G with Tebuconazole for Aquatic Species Species Acute Toxicity Value (mg product/L) Acute Toxicity Value (mg tebuconazole/L) Study ID / Classification

Daphnia magna 48

- hr EC50 = 56.9 48

- hr EC50 = 9.96 1 

### 47567611 / Supplemental Rainbow trout 96

- hr LC50 = 21.7 96

- hr LC50 = 3.8 1 

### 47567612 / Supplemental Lemna gibba 7

- d EC50 = 4.3 7

- d EC50 = 0.76 2 

### 47567616 / Acceptable Lemna gibba 7

- d EC50 = 0.73 7

- d EC50 = 0.13 2 

### 47567617 / Acceptable Green algae 72

- hr EC50 = 11 72

- hr EC50 = 1.9 1 

### 47567618 /Supplemental

1 

### Based on 17.5% tebuconazole

2 

### Based on 17.8% tebuconazole

### Page 50 of 56 

### Table A.3. Summary of Terrestrial Toxicity Studies for Tebuconazole
Taxonomic Group Study Type Tested Species Toxicity Value Acute Toxicity Classification Source (Study Classification) Comments

Birds 1 Acute

Bobwhite quail ( Colinus. virginianus) 21

- D LD50 1988 mg a.i./kg

- bw Slightly Toxic 40700905 (Acceptable) Reduced body weight at 720 ppm (no effect at 432).

Sub

- acute dietary 8

- D LC50 ≥ 5000 mg a.i./kg

- diet Practically non

toxic 40700907 (Acceptable) Mortality at ≥2500 ppm; reduced body weight gain at all concentrations (no effect <325 ppm)

Chronic NOAEC = 73.5 mg a.i./kg

- diet N/A 40700910 (Acceptable) No effects at highest concentration tested

NOAEC <156 mg a.i./kg

- diet NA 41624201 (Acceptable); reduction in offspring body weight

Sub

- acute dietary

Mallard duck ( Anas platyrhynchos ) 8

- D LC50 ≥ 4816 mg a.i./kg

- diet Practically non

toxic 4070090 8 (Acceptable) No mortality ; reduced body weight gain at limit test concentration

Chronic NOAEC = 75 .8 mg a.i./kg

- diet N/A 407009 09 (Acceptable) No effects at highest concentration tested

NOAEC = 320 mg a.i./kg

- diet

NA 41 818301 (Supplemental); based on reduced number of hatchling per pen at 611 ppm (while lower than control, this endpoint is not significant when hatchlings compared to number of live 21

- d embryos)

Mammals Acute Oral Mouse ( Mus musculus ) 2 LD 50 1615 mg a.i./kg

bw Slightly toxic 42090006 (Acceptable)

Acute Inhalation

Laboratory rat ( Rattus norvegicus ) LD50 >0.371 mg/L NA 40700922 (Acceptable); dosing with aerosol for 4 hours with a 14

- d observation period

Chronic 2

- gen NOAEC = 300 mg ai/kg

- diet LOAEC = 1000 mg ai/kg

- diet N/A 40700946 (Acceptable) Based on decreased maternal and pup body weight and decreased pup viability [NOAEC = 15 mg/kg/day; LOAEC = 50 mg/kg

- day]

Insects Acute
contact Honey bee ( Apis mellifera L. ) > 35 μg tebuconazole /bee Practically non

toxic 47567613 (Supplemental) (formulation in which tebuconazole

### Page 51 of 56 

### Table A.3. Summary of Terrestrial Toxicity Studies for Tebuconazole
Taxonomic Group Study Type Tested Species Toxicity Value Acute Toxicity Classification Source (Study Classification) Comments

Acute Oral 10.9 μg tebuconazole /bee N/A concentrations not measured ; fluopyram other a.i. )

Acute
contact 7.6 μg tebuconazole /bee Slightly toxic 48844515 (Acceptable) (formulation ; flupyradifurone other a.i. ) Acute Oral 1.5 μg tebuconazole /bee N/A

Subch ro nic

Earthworm ( Eisenia fetida ) 14

- d LC50 = 875 mg product/kg

dw NA 47567619 (Supplemental) (formulation

- SC400 G; 17.5% tebuconazole); LOAEC= 178 mg product/kg

- dw (NOEC=100)

Chronic 28

- d NOAEC= 30
mg product/kg

dw NA 47567620 (Supplemental) (formulation

- SC400 G; 17.5% tebuconazole); no effects, LOAEC > 30 mg product/kg

- dw

Chronic Parasitoid wasp ( Aphidius rhopalosiphi ) LR50 >3L product/ha NA 47567627 and 47567622 (Supplemental) (formulation

- SC400 G; 17.5% tebuconazole); based on product density rate is 3 lbs product/Acre or 0.53 lb a.i./A

Chronic Ladybird Beetle ( Coccinella septempunctata ) LR50 >3L product/ha NA 47567627 (Supplemental) (formulation

- SC400 G; 17.5% tebuconazole); based on product density rate is 3 lbs product/Acre or 0.53 lb a.i./A

Chronic Green Lacewing ( Chrysoperla

carnea ) LR50 >3L product/ha NA 47567627 (Supplemental) (formulation

- SC400 G; 17.5% tebuconazole); based on product density rate is 3 lbs product/Acre or 0.53 lb a.i./A

Chronic Predatory Mite ( Typholdromus pyri ) LR50 >3L product/ha NA 47567621 (Supplemental) (formulation

- SC400 G; 17.5% tebuconazole); based on product density rate is 3 lbs product/Acr e or 0.53 lb a.i./A

Terrestrial plants Seedling Emergence Dicot

– tomato (Solanum lycopersicum) 21

- D IC 25 = 0.045 lbs ai/acre IC 05 = 0.016 lbs ai/acre N/A 47299201 (Supplemental)

### Page 52 of 56 

### Table A.3. Summary of Terrestrial Toxicity Studies for Tebuconazole
Taxonomic Group Study Type Tested Species Toxicity Value Acute Toxicity Classification Source (Study Classification) Comments

Monocot

– wheat ( Triticum aestivum ) 21

- D IC 25 > 0.4 lbs ai/acre NOAEC = <0.4 lbs

a i /acre N/A

45821301 (Supplemental)

Dicot

– tomato (Solanum lycopersicum) 21

- D IC 25 < 0.4 lbs ai/acre NOAEC = <0.4 lbs

a i /acre N/A

Dicot

– tomato (Solanum lycopersicum) 21

- D IC 25 = 0. 089 lbs ai/acre IC05 = 0.014 lbs a i /acre N/A 4582130 2 (Supplemental)

Dicot

– turnip ( Brassica rapa ) 21

- D IC 25 = 3.4 mg a.i./kg NOAEC = 1 mg a.i./kg N/A

45280001 (Supplemental)

Monocot

– Oat ( Avena sativa) 21

- D IC 25 = 57 mg a.i./kg NOAEC = 10 mg a.i./kg N/A

Dicot

– cucumber ( Cucumis sativus ) 21

- D IC 25 < 0. 18 lbs ai/acre NOAEC

< 0.18 lbs ae/acre N/A

47567614 (Supplemental)

Monocot

– Oat ( Avena sativa ) 21

- D IC 25 > 0. 18 lbs ai/acre NOAEC > 0.18 lbs ae/acre

Vegetative vigor Dicot

— Cucumber ( Daucus carota ) 21

- D IC 25 > 0.4 lbs ai/acre NOAEC = <0.4 lbs ae/acre N/A

45821301 (Supplemental)

(Monocot

– wheat ( Triticum aestivum ) 21

- D IC 25 > 0.4 lbs ai/acre NOAEC = <0.4 lbs ae/acre N/A

### Page 53 of 56 

### Table A.3. Summary of Terrestrial Toxicity Studies for Tebuconazole
Taxonomic Group Study Type Tested Species Toxicity Value Acute Toxicity Classification Source (Study Classification) Comments

Dicot

– Sunflower ( Helianthus annuus L .) 21

- D IC 25 > 0. 18 lbs ai/acre NOAEC > 0.18 lbs ae/acre N/A

47567615 (Supplemental)

Monocot

– Oat ( Avena sativa ) 21

- D IC 25 > 0. 18 lbs ai/acre NOAEC < 0.18 lbs ae/acre N/A

1 Birds represent surrogates for terrestrial

- phase amphibians and reptiles.

2 The acute oral toxicity LD50 value with rats is 3352 mg/kg

- bw (females) MRID 40700917

### Page 54 of 56 

## Appendix **B . Screening Level Models to Evaluate Potential Importance**  **of Drinking Water and Inhalation Exposure Pathways to Birds and Wild**  **Mammals**

SIP ( Screening Imbibition Program, v1.0) Inputs and Conclusions

Table 1. Inputs Parameter Value Chemical name tebuconazole Solubility (in water at 25 o C; mg/L) 36

Mammalian LD 50 (mg/kg-bw) 3352 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) 1988 Avian test species northern bobwhite quail Body weight (g) of "other" avian species Mineau scaling factor 1.15 Mallard NOAEC (mg/kg-diet) Bobwhite quail NOAEC (mg/kg-diet) 73 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) 6.1920 6.1920 Adjusted toxicity value (mg/kg-bw) 2578.2262 11.5374 Ratio of exposure to toxicity 0.0024 0.5367

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) 29.1600 29.1600 Adjusted toxicity value (mg/kg-bw) 1432.2139 7.7598 Ratio of exposure to acute toxicity 0.0204 3.7578

Conclusion* Drinking water exposure alone is NOT a potential concern for birds Exposure through drinking water alone is a potential concern for birds

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

### Page 55 of 56 

### STIR (Screening **Tool for Inhalation Risk, v. 1.0) Inputs and Conclusion**

Non

- definitive rat inhalation value used as definitive value


## Input

Application and Chemical Information
Enter Chemical Name tebuconazole Enter Chemical Use turf 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) 308 Enter Chemical Vapor Pressure (mmHg) 1.30E-08 Enter Application Rate (lb a.i./acre) 1.3

Toxicity Properties

**Bird** Enter Lowest Bird Oral LD 50 (mg/kg bw) 1988 Enter Mineau Scaling Factor 1.15 Enter Tested Bird Weight (kg) 0.178 **Mammal** Enter Lowest Rat Oral LD 50 (mg/kg bw) 3352 Enter Lowest Rat Inhalation LC 50 (mg/L) 0.317 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 ) 2.15E-04 Maximum 1-hour Vapor Inhalation Dose (mg/kg) 2.71E-05 Adjusted Inhalation LD 50 1.05E+00 Ratio of Vapor Dose to Adjusted Inhalation LD 50 2.58E-05 Exposure not Likely Significant Maximum Post-treatment Spray Inhalation Dose (mg/kg) 1.37E-01 Ratio of Droplet Inhalation Dose to Adjusted Inhalation LD 50 1.31E-01 Proceed to Refinements



### Results Mammalian (0.015 kg ) Maximum Vapor Concentration in Air at Saturation (mg/m 3 ) 2.15E-04 Maximum 1-hour Vapor Inhalation Dose (mg/kg) 3.40E-05 Adjusted Inhalation LD 50 1.89E+01 Ratio of Vapor Dose to Adjusted Inhalation LD 50 1.80E-06 Exposure not Likely Significant Maximum Post-treatment Spray Inhalation Dose (mg/kg) 1.73E-01 Ratio of Droplet Inhalation Dose to Adjusted Inhalation LD 50 9.15E-03 Exposure not Likely Significant **NOTE**: When entering values, pres in order to update linked cells.

### Page 56 of 56 

## Appendix C. TerrPlant results

TerrPlant v. 1.2.2 Green values signify user inputs (Tables 1, 2 and 4). Input and output guidance is in popups indicated by red arrows.

Chemical Name PC code Use Application Method

Application Form Solubility in Water (ppm)

Input Parameter Symbol Value Units Application Rate A 1.3 lb ai/A

Incorporation I 1 none Runoff Fraction R 0.02 none

Drift Fraction D 0.01 none

Equation EEC

(A/I)*R 0.026 (A/I)*R*10 0.26 A*D 0.013 ((A/I)*R)+(A*D) 0.039 ((A/I)*R*10)+(A*D) 0.273

Plant type EC 25 NOAEC EC 25 NOAEC

Monocot 0.4 0.4 0.4 0.4

Dicot 0.4 0.4 0.4 0.4

Plant Type Listed Status Dry Semi-Aquatic Spray Drift

Monocot non-listed <0.1 0.68 <0.1 Monocot listed <0.1 0.68 <0.1

Dicot non-listed <0.1 0.68 <0.1 Dicot listed <0.1 0.68 <0.1 Description

Total for semi-aquatic areas Table 1. Chemical Identity.
tebuconazole

golf turf

Table 2. Input parameters used to derive EECs. ground Spray 35 128899

Table 3. EECs for tebuconazole. Units in lb ai/A.

Runoff to dry areas Runoff to semi-aquatic areas Spray drift Total for dry areas

*If RQ > 1.0, the LOC is exceeded, resulting in potential for risk to that plant group. Vegetative Vigor Seedling Emergence

Table 5. RQ values for plants in dry and semi-aquatic areas exposed to tebuconazole through runoff and/or spray drift.* Table 4. Plant survival and growth data used for RQ derivation. Units are in lb ai/A.