### 1 OFFICE OF CHEMICAL SAFETY AND POLLUTION PREVENTION 

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

PC Code: 128976/138976 DP Barcode: 428793 Date: December 15, 2015

MEMORANDUM

Subject Problem Formulation for the Ecological Risk and Drinking Water Exposure Assessments to be Conducted for the Registration Review of Uniconazole and Uniconazole-P.

To: Sue Bartow, Chemical Review Manager Cathryn Britton, Team Leader Kevin Costello, Branch Chief Risk Management and Implementation Branch IV Pesticide Re-evaluation Division

Through: Dana Spatz, Branch Chief Environmental Risk Branch III Environmental Fate and Effects Division

From: James K. Wolf, Ph.D., Soil Physicist Frank Farruggia, Ph.D., Biologist Rosanna Louie-Juzwiak, RAPL Environmental Risk Branch III Environmental Fate and Effects Division

Peer Review: James Hetrick Ph.D., Senior Advisor Environmental Risk Branch III Environmental Fate and Effects Division

Executive Summary

The Environmental Fate and Effects Division (EFED) has completed the preliminary problem formulation for the ecological risk and drinking water exposure assessments to be conducted as 

## JAMES WOLF Digitally signed by JAMES WOLF DN: c=US, o=U.S. Government, ou=USEPA, ou=Staff, cn=JAMES WOLF, dnQualifier=0000014028 Date: 2015.12.15 14:12:13 -05'00'



# JAMES HETRICK Digitally signed by JAMES HETRICK DN: c=US, o=U.S. Government, ou=USEPA, ou=Staff, cn=JAMES HETRICK, dnQualifier=0000005599 Date: 2015.12.15 14:49:05 -05'00' 

### FRANK FARRUGGIA Digitally signed by FRANK FARRUGGIA DN: c=US, o=U.S. Government, ou=USEPA, ou=Staff, cn=FRANK FARRUGGIA, dnQualifier=0000048865 Date: 2015.12.15 14:57:13 -05'00'

### 2 part of the Registration Review of the plant growth regulators uniconazole and uniconazole-P. 1 

### Uniconazole is racemic and is a mixture of 4 is omers. Uniconazole-P is the resolved form of uniconazole 2 

### , where 3 of the 4 isomers (that have less herbicidal activity) remain at lower percentages. To date, the submitted ecotoxicity and fate data appear to have been conducted using the resolved form ( i.e. , uniconazole-P) 3



### , 4 

### . Currently, there are only uniconazole-Pcontaining registered products. In this document, the focus will solely be on uniconazole-P as the stressor of concern.

Uniconazole-P is used as a growth retardant on a wide variety of ornamental and fruiting vegetable crops intended for the retail market 5 

### . The two uniconazole-P end-use products are predominantly applied in commercial greenhouses (indoor only); however, one product label includes use in shade houses and lath houses, which may lead to some outdoor exposures. EFED previously conducted an ecological assessment for the addition of shade houses and lath houses, which identified a number of studies that would be needed to assess potential risk to nontarget organisms ( i.e. , terrestrial and aquatic plants). Additionally, consistent with the Guidance for Assessing Pesticide Risks to Bees (U.S. EPA, et. al., 2014), honey bee toxicity and exposure data would be needed in order to co nduct a risk assessment for pollinators. Below is the list of guideline studies that were identified as being needed in order to assess the outdoor uses of uniconazole-P:

- 850.4100, Seedling Emergence and Seedling Growth (TEP)

- 850.41 50, Vegetative Vig or (TEP)

- 850.4400, Aquatic plan t Toxicity Test usin g Lemna (TGAI)

- 850.4500, Alga l toxicity (TGAI)

- 850.4550, Cyanobacteria tox icity (TGAI)

- 850.30 20, Adult Honey B ee Acute Contact Toxicity Test (Tier 1) ( TGAI)

- 850.30 30, Honey bee toxicity of residues on foliage (Tier 1) (TEP)

- OECD 237, Ad ult Hon e y Bee Acute Or a l Toxicity Test (Tier 1) (TGAI)

- Non-guideline, Ad ult Honey B ee Chronic O ral Tox icity Tes t ( T ier 1) ( TGAI)

- Non-guideline, Larv a e H oney B ee Ac ute Or a l Toxicity Tes t ( T ier 1) ( TGAI)

- Non-guideline, La rvae Honey Bee Chro nic Oral Toxicity Test (Tier 1) (TGAI)

- OECD 75, Semi- field T esting for Pollinators (Tier 2) (TEP)

- Non-guideline, Fiel d T rial of Residu es in Poll en an d Nectar (TEP)

1 Resolved uniconazole-P CAS No 83657-17-4

2 Racemic uniconazole CAS. No. 83657-22-1

3 Odenkirchen, E. Registration 62097-RL – Uniconazole-P Technical; Request for Determination of the Similarity Between Product 62097-RL to Va lent Product 59639-38 for Enviro nmental Data Bridging Purposes ; Request for Sufficiency of Cited Studies for Data Requirements . December 14, 2005.

4 Regelman, E. EFGWB Review of Uniconazole, Response to Registra tion Standard (Clarification of Sign of Rotation of Active Ingredient; Clarification of Chemical Abstracts Registry Numbers . November 19, 1990.

5 According to registrant correspondence received on Nov. 19, 2015.

### 3 - 850.3040, Field Testing for Pollinators (Tier 3) (TEP)

OPP recently received a draft revised label 6 

### that would limit foliar spray applications of uniconazole-P to greenhouse (indoor) use only, to minimize potential drift from foliar sprays from applications made in shade houses or lath houses. If this draft label were to be approved, then the vegetative vigor toxicity (GL. 850. 4150) would not be needed.

The following discussion is a summary of the curr ently registered uses as labeled, the available environmental fate and ecological toxicity data and data uncertainties, and the problem formulation to support the conduct of an exposure and risk assessment for outdoor uses.

Chemical Overview

Use Characterization

Uniconazole-P reduces plant height by reducing internode elongation through inhibition of gibberellin biosynthesis. Uniconazole-P is regist ered for use in commercial greenhouses, shade houses and lath houses on a variety of ornamentals, as well as the following food crops: eggplant, groundcherry, pepino, pepper, tomatillo, and tomato. Uniconazole-P may be applied as a pre-plant application to soil surface, dren ch application, a pre-plant bulb soak or foliar application using standard spray equipment.

There are four Section 3 products (two technical and two end-use products) and one Section 24c product registered for uniconazole-P. The end-use labels ( i.e. , EPA Reg. Nos. 59639-37; 62097-18) indicate that multiple applications can be used. The maximum number of applications per year and maximum application rate per year are not specified. Application rates depend on the desired plant height, duration and degree of control, pot size, stage of growth, method of application, season, and cu ltivar response. Cultural practices such as watering, potting media, fertilization, temperature, and light conditions may affect the growth response to a given dosage.

Summary of Previous Risk Assessments

Based on a previous risk assessment (U.S. EPA, 2008 7 

### ) in support of the proposed addition of shade houses and lath house uses to the Sumagi c product label (EPA Reg. No. 59639-37, Valent Corporation), potential acute risks to fish, aquatic invertebrates, birds, and mammals are

6 Email received on November 30, 2015, with draft label from OPP/PRD, S. Bartow.

7 Anderson, B. and M. Corbin. 2008. Transmittal of the Environmental Fate and Effects Division (EFED) Section 3 Ecological Risk Assessment of Uniconazole Proposed for New Uses in Fruiting Vegetables, Bedding Plants, Bulb Crops, and Ornamental Plants in Greenhouses, Shade houses, and Lath-houses (D349381+; 04/10/08).

### 4 expected to be lower than concern levels. However, levels of concern (LOC) were exceeded for reproductive risk to birds and mammals for the highest assessed application rate (0.09 lb a.i./Acre). EFED concluded that a reduction of th e maximum application rate to 0.07 lb a.i./A would result in no LOC exceedance for birds or mammals.

Uniconazole-P use in shade houses and lath-houses may result in exposure to non-target aquatic and terrestrial plants and animals through dietary or contact exposure, resulting from direct spray, residues on food items, or from ru noff and/or spray drift to adjacent areas. Use of uniconazole-P in greenhouse facilities is likel y to reduce environmental exposures, assuming that runoff from indoor treatments is controlled.

No toxicity studies are available that allow for an estimation of chronic risk to fish or aquatic invertebrates, saltwater organisms, aquatic plants, or terrestrial plants. However, potential risks to freshwater or saltwater organisms from chronic exposure to uniconazole-P were not anticipated given that new endpoints would need to be significantly more sensitive ( e.g. , at least 3,000 times) than the available acute toxicity data, to result in an exceedance of the LOC.

Risk to terrestrial and aquatic plants was noted as a potential risk concern because incidents have been reported in the EIIS that correlate uniconazole-P application to plant damage. Also, since uniconazole-P is a plant growth regulator, it is expected that exposed non-target plants would be affected. As such, the following data were conditionally required to support the addition of the proposed outdoor uses onto the product label: seedling emergence and seedling growth study (OCSPP GL. 850.4100), vegetative vigor study (OCSPP GL. 850.4150; Tier I aquatic plant growth studies (850.4400, 850.4500); and, honey bee acute contact study (OCSPP GL. 850.3020). In 2011, EPA evaluated and granted a data waiver request to Valent Corporation for the submission of these studies (DP Barcode D385384) based on the removal of the shade house uses from their labels.

Environmental Fate and Transport Summary

Uniconazole-P (and uniconazole) is a triazole which contains a double bond and one chiral center. Four isomers are possible with uniconazole-P (two geometrical isomers, E and Z, each with two optical isomers, R and S due to the chiral center) (Appendix A). Uniconazole is racemic and is a mixture of 4 isomers. Uniconazol e-P is the resolved form of uniconazole 8 

### , and is the form used in registered products.

The dominant dissipation mechanisms for uniconazole are leaching, plant uptake, and to a lesser extent microbial degradation. Uniconazole is stable to hydrolysis and persistent to

8 Racemic uniconazole CAS. No. 83657-22-1

### 5 degradation in aerobic terrestrial systems. There are no data on degradation in aerobic aquatic or anaerobic aquatic environments, nor are there any field dissipation studies. The physical and chemical properties that determine the fate and transport are detailed in Table 1 . Available environmental fate data include hydrolysis, ae robic soil metabolism, batch equilibrium studies (adsorption/desorption data), and volatility from soil surface.

Table 1. Chemical Properties and Environmental Fate Parameters of Uniconazole-P (and Uniconazole). Chemical/Fate Parameter Value Description/Comments Source (MRID) Selected Physical/Chemical Parameters Company Code 3307D, XE-1019L - - Common Name Uniconazole Plant Growth Regulators -

SMILES Notation Canonical Isomeric Uniconazole-P: CC(C)(C)C(C(=CC1=CC=C( C=C1)Cl)N2C=NC=N2)O CC(C)(C)[C@@H](/C(=C\C1=CC= C(C=C1)Cl)/N2C=NC=N2)O
Molecular formula C 15 H 18 N 3 OCl - 46657801

Molecular mass 291.78 g/mole - 46657801 Vapor pressure (20 q C) 4.0 x 10 -5 mm Hg (S)-(E)-isomer 40820501

Water solubility (25 q C) 8.41 mg/L (S)-(E)-isomer 40820501 Herts b

Octanol-water partition

coefficient (Log K OW ) 3.77 3.84 c (TGAI) Temperature unspecified (S)-(E)-isomer Herts b

Henry’s Law Constant (25°C) 1.83 x 10 -6 atm-m 3 /mole Calculated -

Persistence

Hydrolysis half-life (days; 25 q C) Stable @ pH 5, 7, 9 40345427 40573601
Aerobic soil metabolism halflife (25°C) 857 to 1,880 days a The (S)-(E)-isomer [the active isomer] 40345428 40573602
Volatilization from Soil Surface [Guideline # 163-2] 0.012 to 0.014 % of applied radioactivity (S)-(E)-isomer Required for greenhouse use. 40462604

Vapor-Phase Photodegradation half-life 32.5 days Uniconazole Artificial light 1⁄4 to 1⁄2 the

intensity of sunlight 40820501 40462604

Mobility Soil-water partition coefficients (K F ) [Freundlich] (mL/g) 0.20 to 48.6 Average = 18.6 The (S)-(E)-isomer [the active isomer] 40345429 40573602 40724301

### 6 Chemical/Fate Parameter Value Description/Comments Source (MRID) Organic carbon-normalized soil

partition coefficients (K FOC ) (mL/g oc ) 137 to 636 Average = 371 The (S)-(E)-isomer [the active isomer] 40345429 40573602 40724301
Bioconcentration Factor in Fish

Fish bioconcentration factors (steady-state) 35X, 75X, 99X for fillet, whole fish and viscera, respectively - 40657901

a Half-lives estimated [Slow t 1⁄2 Model] with PestDF 9 following NAFTA Guidance 10

. b http://sitem.herts.ac.uk/aeru/ppdb/en/Reports/675.htm#none



### Uniconazole is a triazole fungicide. Several of the triazole class fungicides have been documented to degrade to 1,2,4-triazole; however, 1,2,4-triazole was not detected in any of the environmental fate studies. Several identified degradates ( i.e. , 7KE, 7KZ, 7SA, 7SK, and 7EP) were detected at percentages of applied less than 5% (Appendix A). These degradates have not been previously identified as being a concern for toxicity and have not been included in this
assessment.

Exposure Pathways

For terrestrial vertebrates, the major routes of exposure to uniconazole-P are considered to be via contact exposure and dietary ingestion of fo od items such as plants and/or animals that have uniconazole-P residues as a result of direct application, spray drift, and/or runoff.Exposure to terrestrial vertebrates through inhalation is considered unlikely given uniconazoleP’s low vapor pressure. The lowest rat inhalation endpoint is non-definitive (LC 50 

### > 2.75 mg/L; MRID 40345409); even if using this as a definitive value, the results from the Screening Tool for Inhalation Risk (STIR v. 1.0) indicate that inhalation is not expected to be an exposure route of concern. The Screening Imbibition Program (SIP v. 1.0) suggests that drinking water alone is not expected to be an exposure pathway of concern for acute and chronic exposure to mammals, and for acute exposures to birds. However, chronic exposure to contaminated drinking water alone may be a potential exposure route of concern for birds ( Appendix B ).

9 http://www.epa.gov/oppefed1/ecorisk_ders/degradation_kinetics/NAFTA_Degradation_Kinetics_Equations.htm

10 http://www.epa.gov/oppefed1/ecorisk_ders/degradation_kinetics/archive2015/ftt_sop_using_nafta_guidance.pdf

### 7 Stressor of Concern

The stressor of concern for terrestrial and aquatic organisms is the parent uniconazole-P. The concentrations of degradate compounds are unlikely to be greater than the parent, as parent is assumed to be persistent. Therefore, any potential risk posed by degradates is expected to be inconsequential in comparison to the parent.

Measures of Exposure

To estimate risks to aquatic and terrestrial organisms from exposure to uniconazole-P, all exposure modeling and resulting risk conclusion s will be made based on maximum application rates, application methods, and any mitigation measures indicated on the label or formally agreed to by registrants prior to the conduct of the risk assessments. Exposure modeling ( e.g. , Surface Water Concentration Calculator ) for uniconazole-P at maximum treatment levels, rates in the lath house or shade houses ( i.e. , based upon concentration per 100 ft 2 

### ) and an upperbound estimated exposure rate ( i.e. , based upon the number of plants/A) will be used for aquatic estimated environmental concentrations (EEC). Models that w ill be used to predict estimated environmental concentrations (EECs) of uniconazole-P are discussed on EPA’s model website . These models include: SWCC, PRZM-GW, T-REX, and TerrPlant.

The Agency is not aware of surface water or groundwater monitoring conducted by federal or state agencies. However, if monitoring data of uniconazole or uniconazole-p becomes available, they will be considered in the assessment.

An updated drinking water assessment (DWA) is not anticipated to be needed at this time; however, if one is needed, an updated exposure assessment will incorporate the current water exposure models ( e.g. , SWCC and PRZM-GW) and guidance for model input parameters.

Measure of Effects

Ecological effects data are used as measures of direct and indirect effects to biological receptors. Data are typically obtained from re gistrant-submitted studies or from literature, including studies housed in ECOTOX. ECOTOX is a source for locating single chemical toxicity data and potential chemical mixture toxicity data for aquatic life, terrestrial plants, and wildlife. ECOTOX was created and is maintained by the USEPA, Office of Research and Development, and the National Health and Environmental Ef fects Research Laboratory's Mid-Continent Ecology Division.

### 8 Table 2 and Table 3 are summaries of the available ecotoxicity data submitted by the registrant.

Table 2. Summary of the Most Sensitive Endpoints from Terrestrial Toxicity Studies for Uniconazole-P

Test Type Endpoint Comments MRID

Laboratory rat Rattus norvegicus LD 50 

### = 430 mg/kgbw Acceptable 40345405

Laboratory rat Rattus norvegicus NOAEC = 150 ppm (7.5 mg/kg-bw) Acceptable 41162004

Northern Bobwhite Quail ( Colinus virginianus ) LD 50 

### = 1461 mg/kgbw Acceptable 40345419

Mallard Duck Anas platyrhynchos LC 50 

### = 3442 ppm Acceptable 40345420

Northern Bobwhite Quail ( Colinus virginianus ) NOAEL = 20 ppm Supplemental study in quail.

Reproduction NOAEC in mallard ducks was 20 ppm. LOAEC was 80 ppm based on increased incidence of cracked eggs. 40936007

Honey Bee Acute Contact None Invalid study 40345426

Table 3. Summary of the Most Sensitive Endpoints from Aquatic Toxicity Studies for Uniconazole-P.

Test Type Endpoint Comments MRID

Acute Freshwater Fish 6.8 mg/L Acceptable study in bluegill. Rainbow trout and carp LC 50 

### s were 14.8 mg/L and 7.5 mg/L, respectively. 40345423

Acute Freshwater Invertebrate Daphnia magna EC 50 

### >10 mg/L Supplemental study because test concentrations did not reach the limit concentration and 50% inhibition was not achieved. Irregular swimming occurred at 10 mg/L. 40345425

### 9 Integration of Exposure and Effects

Risk characterization is the integration of exposure and ecological effects to determine the potential ecological risk from the use of pesticides and the likelihood of direct and indirect effects to non-target organisms in aquatic and te rrestrial habitats. For the assessment of risks, the risk quotient (RQ) method is used to compare exposure and measured toxicity values. EECs are divided by acute and chronic toxicity values. The resulting RQs are then compared to the Agency’s Levels of Concern (LOCs). These criteria will be used to indicate when uniconazole-P use, as directed on the label, has the potential to cause adverse direct or indirect effects to non-target organisms. In addition, any additional incident data from the Ecological Incident Information System v. 2.1.1 (EIIS), maintained by EFED; 2) the Avian Incident Monitoring System (AIMS), maintained by the American Bird Conserva ncy; and, 3) the Incident Data System (IDS) maintained by OPP will be considered as part of the risk characterization.

Incident Information

Three incidents reported in EIIS involving un iconazole-P have been reported, all of which involve damage to terrestrial plants (petunias or oak trees). In all cases uniconazole-P was applied directly to the damaged plants. The certainty index for these uses was probable or possible. Table 4 summarizes the available incidents.

Table 4. Summary of Incidents Reported for Uniconazole-P in EIIS.

Incident No. Product Species Affected Description of Effects Certainty Index

I007467-023 Sumagic Petunia Spots on le aves and scarring on stem tissues Possible

I007467-24 Sumagic Petunia Blisters and Leaf spots Possible

I002969-057 Prunit Oak Unspecified damage Probable



### Endocrine Disruptor Screening Program (EDSP)

Uniconazole-P was not included in the first group of 67 chemicals issued an order to conduct Tier 1 EDSP testing. Tier 1 screening resu lts for List 1 chemicals are available athttp://www2.epa.gov/ingredients-used-pesticide-products/endocrine-disruptor-screeningprogram-tier-1-assessments . For additional information on the EDSP, visit http://www.epa.gov/endo/

.

### 10 Endangered Species

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 Join t Interim Approaches developed to implement the recommendations of the April 2013 Nation al Academy of Sciences (NAS) report, Assessing Risks to Endangered and Threatened Species from Pesticides . The NAS report outlines recommendations on specific sc ientific and technical issues related to the development of pesticide risk assessments that EPA and the Se rvices must conduct in connection with their obligations under the ESA and FIFRA. EPA w ill address concerns specific to uniconazole -P in connection with the development of its final registration review decision for uniconazole -P

.
In November 2013, EPA, the U.S. Fish and Wildli fe 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 specie s from pesticides. These Interim Approaches were developed jointly by the agencies in response to the NAS recommendations, and reflect a common approach to risk assessment shared by th e 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 the Interim Approaches to assess the potential risk s of pesticides to listed species and their designated critical habitat, th is ecological problem formulat ion supporting the Preliminary Work Plan for uniconazole -P 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 registration review of uniconazole -P will describe the level of ESA analysis completed for this part icular 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 bein g 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 uniconazole -P as part of completing this registration review.

### 11 Preliminary Identification of Data Gaps

The following sections identify data that are needed to complete an ecological risk assessment in support of the Registration Review of the registered uses of uniconazole-P.

Environmental Fate and Transport

Table 5 identifies the environmental fate studies submitted by the registrant, as well as study classifications and whether or not additional data are needed in order to support the registration review exposure assessments. It was not possible to confirm that the test material in the environmental fate studies was uniconazole-P (see footnote in Table 5 and Appendix A). However, there are sufficient environmental fate data to conduct an exposure assessment for the existing uses, if needed.

Table 5. Environmental Fate Data for Uniconazole-P a



### .

OCSPP Guideline Data Requirement MRID Study Classification Are Data Needed to Conduct Risk Assessment

835.2120 Hydrolysis 40345427 40573601 Acceptable No

835.2370 Aqueous Photolysis  ̄ - No No studies are currently available. In the absence of empirical data, stability was assumed. In order to assess outdoor uses, the submission of these data would help to address uncertainty with assumed stability.

835.2410 Soil Photolysis - No In the absence of empirical data, stability was assumed. In order to assess outdoor uses, the submission of these data would help to address uncertainty with assumed stability.

835.4100 Aerobic Soil Metabolism 40345428 40573602 Acceptable No

835.4200 Anaerobic Soil Metabolism - - No No studies are currently available. This study is useful for characterization but is not a model input for Tier I exposure assessments.

835.4300 Aerobic Aquatic Metabolism  ̄ - No In the absence of empirical data, stability was assumed. In order to assess outdoor uses, the submission of these data would help to address uncertainty with assumed stability.

### 12 OCSPP Guideline Data Requirement MRID Study Classification Are Data Needed to Conduct Risk Assessment

835.4400 Anaerobic Aquatic Metabolism  ̄ - No No studies are currently available. This study is useful for characterization but is not a model input for Tier I exposure assessments.

835-2370 Vapor-Phase Photodegradation 40820501 40462604 Acceptable No --

835.1230 Adsorption/Desorption (Batch Equilibrium) 40345429 40573602 40724301 Acceptable No --

835.6100 Aquatic Field Dissipation - - No --

835.6100 Terrestrial Field Dissipation - - No No studies are currently available. In the absence of empirical data, stability was assumed. In order to assess outdoor uses, the submission of these data would help to characterize uniconazole-P’s fate in the environment.

835.1730 Bioaccumulation in Fish 40657901 Acceptable No --

a The studies identified the test material as S-3307D; ho wever, S-3307D has referenced as both uniconazole and uniconazole-P, additionally the CAS # of have been used interchangeably. Study introductions suggest the test material was uniconazole-P (CAS No. 83567-17-4).



### Effects

The ecological effects database is incomplete for the risk assessment to support outdoor uses. Table 6 and Table 7 identify the ecological effects studie s, as well as study classifications and whether or not further data are needed in order to support the risk assessment for all currently registered uses of uniconazole.

Table 6. Submitted Aquatic Ecological Effects Data for Uniconazole-P

OCSPP Guideline Data Requirement Submitted Studies (MRID) Study Classifications Are data needed to conduct risk assessment? Comments

850.1010 Freshwater invertebrate acute toxicity 40345425 Supplemental No

### 13 OCSPP Guideline Data Requirement Submitted Studies (MRID) Study Classifications Are data needed to conduct risk assessment? Comments

850.1025 850.1035 850.1045 850.1055 Saltwater invertebrate acute toxicity No study submitted No Saltwater fish and invertebrates would need to be approximately 200-fold or 300- fold, respectively, more sensitive than freshwater organisms on an acute basis to result in LOC exceedances

850.1075 Freshwater fish acute toxicity 40345423 Acceptable

No -- 40345422 Acceptable 40345424 Supplemental

850.1075 Saltwater fish acute toxicity No study submitted -- No Saltwater fish and invertebrates would need to be approximately 200-fold or 300- fold, respectively, more sensitive than freshwater organisms on an acute basis to result in LOC exceedances

850.1300 Freshwater invertebrate life cycle No study submitted -- No Uniconazole-P is expected to be persistent in the aquatic environment. However; the chronic NOAEC would need to be approximately 5000-fold lower than the acute EC50 to result in LOC exceedances for the registered uses.

850.1350 Saltwater invertebrates life cycle No study submitted -- No Potential acute risks to freshwater invertebrates were considerably lower than concern levels, and potential risks from chronic exposure to uniconazole-P were presumably lower than concern levels.

850.1400 Freshwater fish early-life stage No study submitted -- No

--

### 14 OCSPP Guideline Data Requirement Submitted Studies (MRID) Study Classifications Are data needed to conduct risk assessment? Comments

850.1400 Saltwater fish early-life stage No study submitted -- No --

850.1500 Fish life cycle No study submitted -- No The life-cycle NOAEC would need to be approximately 3700 fold lower than the acute LC50 to result in LOC exceedances.

850.4400 Aquatic plant growth: Tier II vascular plants No study submitted -- Yes Needed to assess risk from shade house or other outdoor uses; no data needed for indoor

uses

850.4500 Aquatic Plant Growth: Tier II Algal Toxicity No study submitted -- Yes Needed to assess risk from shade house or other outdoor uses; no data needed for indoor

uses

850.4550 Aquatic Plant Growth: Tier II Cyanobacteria Toxicity No study submitted -- Yes Needed to assess risk from shade house or other outdoor uses; no data needed for indoor

uses



### Table 7. Submitted Terrestrial Ecological Effects Data for Uniconazole-P

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

850.2100 Avian oral toxicity 40345418 Acceptable

No Acute avian oral toxicity studies using mallard duck and bobwhite quail are available. Although data are not available for a passerine species, based on existing information, it is not expected that a passerine study would add any valuable information to the avian risk
assessment. 40345419 Acceptable

850.2200 Avian dietary toxicity 40345420 Acceptable No -- 40345421 Acceptable

### 15 OCSPP Guideline Data Requirement Submitted Studies (MRID) Study Classifications Are data needed for risk assessment? Comments

850.2300 Avian reproduction 40936007/ 43634301 Supplemental/
No -- 40936009/ 43634302 Supplemental/

850.3020 Honey bee
acute contact toxicity 40345426 Invalid Yes Needed to assess risk from shade house or other outdoor uses; no data needed for indoor

uses
NonGuideline Study (Tier I) Honey bee adult acute oral toxicity No study submitted -- Yes Needed to assess risk from shade house or other outdoor uses; no data needed for indoor

uses
NonGuideline Study (Tier I) Honey bee larvae acute oral toxicity No study submitted -- Yes Needed to assess risk from shade house or other outdoor uses; no data needed for indoor

uses
NonGuideline Study (Tier I) Honeybee adult chronic oral toxicity No study submitted -- Yes Needed to assess risk from shade house or other outdoor uses; no data needed for indoor

uses
NonGuideline Study (Tier I) Honey bee larvae chronic oral toxicity No study submitted -- Yes Needed to assess risk from shade house or other outdoor uses; no data needed for indoor

uses

850.3030 Honey bee toxicity of residues on foliage No study submitted Yes Dependent on Tier I results

NonGuideline Study (Tier II) Semi-field testing for pollinators (tunnel or colony feeding studies) No study submitted

-- Yes Dependent on Tier I results

NonGuideline Study (Tier II) Field trial of residues in pollen and
nectar No study submitted

-- Yes Dependent on Tier I results

### 16 OCSPP Guideline Data Requirement Submitted Studies (MRID) Study Classifications Are data needed for risk assessment? Comments

850.3040 (Tier III) Field testing for pollinators No study submitted -- Yes Dependent on Tier I results

850.4100 Terrestrial plant toxicity: Tier II seedling
emergence No study submitted -- Yes Needed to assess risk from shade house or other outdoor uses; no data needed for indoor

uses

850.4150 Terrestrial plant toxicity: Tier II vegetative vigor No study submitted -- Yes Needed to assess risk from shade house or other outdoor uses; no data needed for indoor

uses

### 17 APPENDIX A.

Summary of Fate Data

The chemical structures of the four unico nazole-P isomers along with the chemical nomenclature are given in Table A-1. Uniconazole-P is the resolved form of uniconazole (a process to increase the percent of most active isomer [(S)-(E)-isomer] with the other three isomers occurring as lower percentages. Among the four isomers the (S)-(E)-isomer [or (E)-(S)- isomer] has the highest biologic al activity which is derived from the ability of inhibitingbiosynthesis of gibberellin, and is a major ingredient of the plant growth retardant uniconazoleP. There is some uncertainty concerning the whether uniconazole (racemic) or uniconazole-P (resolved form) was used as the test material (specified on as S-3307D) in the environmental fates studies as there was some inconsistency in the use of the CAS Number (83657-22-1 or 83657-17-4) and Company ID (S-3307D), and name (uniconazole or uniconazole-P) between study reports and literature. The specific study introductions did suggest that the test material was the resolved uniconazole-P.

Abbreviation a Chemical Name a Synonym Used by Registrant Nomenclature Used by Registrant (S)-(E)-isomer b (S)-E-1(p-chlorophenyl)-4,4-dimethyl-2-(1,2,4-triazol-1-yl)-1-penten-3-ol (E)-(S)-isomer (R)-(E)-isomer (R)-E-1(p-chlorophenyl)-4,4-dimethyl-2-(1,2,4-triazol-1-yl)-1-penten-3-ol (E)-(R)-isomer (S)-(Z-isomer (S)-Z-1(p-chlorophenyl)-4,4-dimethyl-2-(1,2,4-triazol-1-yl)-1-penten-3-ol (Z)-(S)-isomer (R)-(Z)-isomer (R)-Z-1(p-chlorophenyl)-4,4-dimethyl-2-(1,2,4-triazol-1-yl)-1-penten-3-ol (Z)-(R)-isomer

a Nomenclature used by Registrant Submissions.
b Most active isomer. Table A-1. Structures and Chemical Names for the Four Isomers of Uniconazole and Uniconazole-P.



### Hydrolysis (MRID 40345427, 40573601)

The S-E isomer showed no degradation at pH 5, 7, or 9. Estimated half-lives were beyond the duration of the study but suggest half-lives of at least one year. Studies also suggest that the

### 18 other isomers exhibit similar hydrolytic ha lf-lives. Trace amounts (<0.1% of applied radioactivity) of the Z-isomers were observed, with no tendency to increase with time. The parent compound is resistant to hydrolysis at pH 5, 7, and 9 (25°C, dark, sterile conditions) and that the E/Z isomerization and R/S epimerization did not occur under these conditions.
Aerobic Soil Metabolism (40345428, 40573602)

The half-lives for the (S)-(E)-isomer ranged from 857 to 1,880 days varied due to radiolabel location and soil type. Generally, the E-isomers had longer half-lives compared to the Z-isomers.

The four isomers of uniconazole-P; E and the Z and the corresponding (R) and (S) were separately labeled in the phenyl (Ph- 14 

### C) and the 1,2,4-triazole (Trz- 14 

### C) rings and were aerobically incubated for a 12-month period in two soils. Several were unique to the E and Z isomers. For the (S)-(E)-isomer, the predominate degradation product was 1-(4-chlorophenyl)- 4,4-dimethyl-2-(1,2,4-triazole-1,2-epoxypentan-3-ol ( 7EP ) (<1.5% of applied after 12 months). Between 2.4 and 5.4% CO 2 

### evolved depending upon the soil. The bound residues increased with time (27 to 46% after 12 months). However, degradation half-lives varied by isomer and followed the order (R)-(Z) -> (S)-(Z) > (R)-(E) > (S)- (E) with corresponding half-lives of 3 to 4 days, 300 to 500 days, 260 to 1,250 days, and 857 to 1,880 days, respectively.

Transformation Products

Uniconazole-P is a triazole fungicide, several of the triazole class fungicides have been documented to degrade to 1,2,4-triazole. However, 1,2,4-triazole was not detected in any ofthe environmental fate studies. Other degradates identified in environmental fate studies are E1-(4-chlorophenyl)-4,4-dimethyl-2-(1,2,4-triazole-1-yl)-1-pentene-3-one ( 7KE ) , Z-1-(4- chlorophenyl)-4,4-dimethyl-2-(1,2,4-triazole-1-yl)-1-pentene-3-one ( 7KZ ), 1-(4-chlorophenyl)- 4,4-dimethyl-2-(1,2,4-triazole-1-yl)-pentan-3-ol ( 7SA ), 1-(4-chlorophenyl)-4,4-dimethyl-2-(1,2,4- triazole-1-yl)-pentan-3-one ( 7SK ), 1-(4-chlorophenyl)-4,4-dimet hyl-2-(1,2,4-triazole-1-yl)-1,2- epoxypentan-3-ol ( 7EP ), and CO 2 

### . All identified degradates were detected at percentages of applied less than 5%. These degradates have not been previously identified as being a concern for toxicity by HED and have not been included in exposure modeling.

A proposed degradation pathways of the (E)- and (Z)-isomers of uniconazole (uniconazole-P) in aerobic soil is shown in Table A-2.

### 19 Table A-2. Proposed degradation pathways of the (E)- and (Z)-isomers in aerobic soil (MRID 40345428).



### Mobility (Sorption) 40345429, 40573602, 40724301)

Adsorption of the (S)-(E) isomer appears to be somewhat dependent on the amount of soil organic matter (MRID 40345429, 40573602, 40724301, and 40728501) with K F 

### ranging from 0.2 to 45 and corresponding K FOC 

### s ranging from 137 to 636. Subsequent analysis suggests a good correlation between K F 

### and fraction of organic carbon (%OC)) with the exception of the Kodaira and Sapporo soils. Measured soil properties for these two soils suggest other factors that may influenced the sorption (K F 

### ) values. Both of these soils had th e highest exchange acidity values (Table 3 MRID 40573602); the exchange acidity values were 53.9 (units not specified) and 35.0 for the Kodaira and Sapporo soil, respectively. Soil pHs values were acidic, 4.4 and 5.3 Kodaira and Sapporo, respectively.

Study authors reported that the Aichi and Muko soils did not adsorbed 30% of applied 14 

### C as observed in the other soils (MRID 40724301). They suggest experimental error as the cause. However, these soils had the lowest organic carbon content (based upon organic matter) and high sand percentages which could also influence sorption capacity.

The soil texture ( i.e. , particle size distribution) and cation exchange capacity (CEC) information submitted by the registrant (MRID 40573602) in order to compare Japanese soils to United States soils is not sufficient. Other factors such as parent material is equally important, for which there was no information submitted, may influence the sorption observed in these two soils. Japanese soils are much more likely to be formed in volcanic material compared to the

### 20 United States. There is uncertainty about the repr esentativeness of the parent material for all the soils used (mobility and aerobic soil meta bolism) being representative of U.S. soils. Additionally, the units of measurement and what was included in the exchangeable acidity would be informative (it is assumed to be meq Fe +3 

### + Al +3 

### /100 g). Specific information would include soil mineralogy ( i.e. , clay), soil parent material ( i.e. , volcanic), drainage class, and climate conditions (temperature and precipitation) would be informative to relate the Japanese soils used for the aerobic soil metabolism study a nd the soil sorption partition coefficients to U.S. soils.

Volatilization of Uniconazole from Soil Surface

The volatilization rate and air concentration of radioactivity (S)-(E)-isomer) on the first day were 7.06 x 10 -6 

### μ g/cm 2 

### /hour and 7.14 x 10 -2 

### μ g/m 3 

### , respectively, and gradually decreasing with time. Uniconazole volatility from soil was low during a 30 day period; with 0.012% and 0.014% of the applied radioactivity volatilized from soil (M RID 40462604). The unchanged (S)-(E)-isomer was a main component of the radiocarbon in the extracts of soil and polyurethane foam plug.

Vapor-Phase Photodegradation of Uniconazole

The photodegradation half-life for uniconazole in air was 32.5 days (first-order rate constant) under artificial light artificial sunlight [24 hours exposure with a lamp with intensity 1⁄4 to 1⁄2 the intensity of sunlight (MRID 40820501). The degradation products identified after 31 days of exposure to light are summarized in Table A-3.

Table A-3. Uniconazole Photodegradation Products (MRID 40820501). % AR Abbreviation, Chemical Name

### 21 APPENDIX B.
Screening Imbibition Program Version 1.0

Table 1. Inputs Parameter Value Chemical name Uniconazole-P Solubility (in water at 25 o C; mg/L) 8.41

Mammalian LD 50 (mg/kg-bw) 430 Mammalian test species laboratory rat Body weight (g) of "other" mammalian species

Mammalian NOAEL (mg/kg-bw) 7.5 Mammalian test species laboratory rat Body weight (g) of "other" mammalian species

Avian LD 50 (mg/kg-bw) 1461 Avian test species mallard duck Body weight (g) of "other" avian species Mineau scaling factor 1.15

Mallard NOAEC (mg/kg-diet) 80 Bobwhite quail NOAEC (mg/kg-diet) 20 NOAEC (mg/kg-diet) for other bird species Body weight (g) of other avian species NOAEC (mg/kg-diet) for 2nd other bird species Body weight (g) of 2nd other avian species

Table 2. Mammalian Results Parameter Acute Chronic Upper bound exposure (mg/kg-bw) 1.4465 1.4465 Adjusted toxicity value (mg/kg-bw) 330.7390 5.7687 Ratio of exposure to toxicity 0.0044 0.2508

Conclusion* Drinking water exposure alone is NOT a potential

concern for mammals Drinking water exposure alone is NOT a potential

concern for mammals

### 22 Table 3. Avian Results Parameter Acute Chronic Upper bound exposure (mg/kg-bw) 6.8121 6.8121 Adjusted toxicity value (mg/kg-bw) 758.5883 2.1260 Ratio of exposure to acute toxicity 0.0090 3.2042

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.

STIR Version 1.0 results 

# Input

Application and Chemical Information Enter Chemical Name Uniconazole-P Enter Chemical Use 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) 297.78 Enter Chemical Vapor Pressure (mmHg) 4.00E-05 Enter Application Rate (lb a.i./acre) 0.07

Toxicity Properties
Bird Enter Lowest Bird Oral LD 50 (mg/kg bw) 1461 Enter Mineau Scaling Factor 1.15 Enter Tested Bird Weight (kg) 0.178 Mammal Enter Lowest Rat Oral LD 50 (mg/kg bw) 430 Enter Lowest Rat Inhalation LC 50 (mg/L) 2.75 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 ) 6.41E-01 Maximum 1-hour Vapor Inhalation Dose (mg/kg) 8.06E-02 Adjusted Inhalation LD 50 5.21E+01

### 23 Ratio of Vapor Dose to Adjusted Inhalation LD 50 1.55E-03 Exposure not Likely Significant Maximum Post-treatment Spray Inhalation Dose (mg/kg) 7.40E-03 Ratio of Droplet Inhalation Dose to Adjusted Inhalation LD 50 1.42E-04 Exposure not Likely Significant


### Results Mammalian (0.015 kg ) Maximum Vapor Concentration in Air at Saturation (mg/m 3 ) 6.41E-01 Maximum 1-hour Vapor Inhalation Dose (mg/kg) 1.01E-01 Adjusted Inhalation LD 50 1.64E+02 Ratio of Vapor Dose to Adjusted Inhalation LD 50 6.19E-04 Exposure not Likely Significant Maximum Post-treatment Spray Inhalation Dose (mg/kg) 9.30E-03 Ratio of Droplet Inhalation Dose to Adjusted Inhalation LD 50 5.68E-05 Exposure not Likely Significant