Page 1 of 241 Cl O N O N N ENVIRONMENTAL FATE AND EFFECTS CHAPTER Environmental Fate and Ecological Risk Assessment For TRIADIMEFON ( CAS#: 43121 43 3) 1( 4 chlorophenoxy) 3,3 dimethyl 1( 1,2,4 triazol 1 yl) 2 butanone USEPA PC Code: 109901 Reregistration January 19, 2006 ERB II Team:

Jonathan Angier, Ph. D.

Michelle Embry, Ph. D.

Environmental Fate and Effects Division Secondary Review:

Dana Spatz, RAPL Branch Chief:

Tom Bailey, Ph. D.

Environmental Risk Branch II Environmental Fate and Effects Division Page 2 of 241 TABLE OF CONTENTS I. EXECUTIVE SUMMARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 4 of 236 A. Nature of the Chemical Stressor . . . . . . . . . . . . . . . . . . . . . . . . . . Page 4 of 236 B. Potential Risks to Non target Organisms . . . . . . . . . . . . . . . . . . . Page 4 of 236 C. Conclusions  Exposure Characterization . . . . . . . . . . . . . . . . . . Page 10 of 236 D. Conclusions  Effects Characterization . . . . . . . . . . . . . . . . . . . . Page 10 of 236 E. Uncertainties and Data Gaps . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 10 of 236 II. PROBLEM FORMULATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 12 of 236 A. Stressor Source and Distribution . . . . . . . . . . . . . . . . . . . . . . . . Page 12 of 236 1. Source and Intensity . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 12 of 236 2. Physical and Chemical Properties . . . . . . . . . . . . . . . . . . Page 13 of 236 3. Mode of Action . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 14 of 236 4. Overview of Pesticide Usage . . . . . . . . . . . . . . . . . . . . . . Page 14 of 236 B. Receptors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 14 of 236 1. Ecological Effects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 14 of 236 2. Ecosystems at Risk . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 15 of 236 C. Conceptual Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 16 of 236 1. Terrestrial Environment . . . . . . . . . . . . . . . . . . . . . . . . . Page 16 of 236 2. Aquatic Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 18 of 236 D. Analysis Plan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 18 of 236 1. Preliminary Identification of Data Gaps and Methods . . . Page 19 of 236 2. Measures to Evaluate Risk Hypotheses . . . . . . . . . . . . . . Page 19 of 236 3. Risk Quotients and Levels of Concern . . . . . . . . . . . . . . . Page 25 of 236 III. ANALYSIS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 28 of 236 A. Expanded Use Characterization . . . . . . . . . . . . . . . . . . . . . . . . . Page 28 of 236 B. Exposure Characterization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 30 of 236 1. Environmental Fate and Transport . . . . . . . . . . . . . . . . . Page 30 of 236 2. Aquatic Resource Exposure Assessment . . . . . . . . . . . . . Page 34 of 236 3. Terrestrial Organism Exposure Modeling . . . . . . . . . . . . Page 38 of 236 4. Non Target Plant Exposure Modeling . . . . . . . . . . . . . . . Page 42 of 236 C. Ecological Effects Characterization . . . . . . . . . . . . . . . . . . . . . . Page 43 of 236 1. Aquatic Effects Characterization . . . . . . . . . . . . . . . . . . . Page 47 of 236 2. Terrestrial Effects Characterization . . . . . . . . . . . . . . . . . Page 49 of 236 IV. RISK CHARACTERIZATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 54 of 236 A. Risk Estimation  Integration of Exposure and Effects Data . . . . Page 54 of 236 1. Non target Aquatic Animals and Plants . . . . . . . . . . . . . . Page 54 of 236 Page 3 of 241 2. Non target Terrestrial Animals . . . . . . . . . . . . . . . . . . . . Page 59 of 236 3. Non target Terrestrial Plants . . . . . . . . . . . . . . . . . . . . . . Page 66 of 236 B. Risk Description  Interpretation of Direct Effects . . . . . . . . . . . Page 66 of 236 1. Risks to Aquatic Organisms and Plants . . . . . . . . . . . . . . Page 67 of 236 2. Risks to Terrestrial Organisms and Plants . . . . . . . . . . . . Page 69 of 236 3. Incident Data Review . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 75 of 236 4. Federally Threatened and Endangered ( Listed) Species of Concern . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 75 of 236 C. Description of Assumptions, Limitations, Uncertainties, Strengths, and Data Gaps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 86 of 236 1. Assumptions and Limitations Related to Exposure for All Taxa . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 86 of 236 2. Assumptions and Limitations Related to Exposure for Aquatic Species . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 86 of 236 3. Assumptions and Limitations Related to Exposure for Terrestrial Species . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 88 of 236 4. Assumptions and Limitations Related to Effects Assessment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 92 of 236 5. Assumptions Associated with the Acute LOCs . . . . . . . . Page 93 of 236 LITERATURE CITED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 95 of 236 APPENDICES APPENDIX A. Environmental Fate Studies . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 97 of 236 APPENDIX B. Aquatic Exposure Modeling Assessment  PRZM EXAMS Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 104 of 236 APPENDIX C. Triadimefon and Triadimenol Toxicity Data . . . . . . . . . . . . . . Page 168 of 236 APPENDIX D: Terrestrial Organism RQ Calculations Based on Mean Kenaga Residue Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 179 of 236 APPENDIX E. Endangered Species Associated with Triadimefon Use . . . . . . Page 183 of 236 APPENDIX F. Triadimefon Papers Accepted by ECOTOX and OPP/ EFED . . Page 208 of 236 APPENDIX G. Triadimefon Papers Accepted by ECOTOX and Rejected by OPP/ EFED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 213 of 236 APPENDIX H. Triadimefon Papers Rejected by ECOTOX . . . . . . . . . . . . . . Page 216 of 236 APPENDIX I: Fugacity Approach for Earthworm Pesticide Residue Modeling Page 235 of 236 Page 4 of 241 I. EXECUTIVE SUMMARY The purpose of the ecological risk assessment ( ERA) of triadimefon ( Bayleton ® ) is to assist the Agency in evaluating the actions needed, if any, to address ecological risks from currently registered uses of triadimefon. The goal of reregistration is to update labeling and use requirements and to reduce potential risks associated with older pesticide active ingredients.

A. Nature of the Chemical Stressor Triadimefon ( Bayleton ® ) is a broad spectrum, systemic fungicide that is used for the systemic control of various fungal diseases in fruits, turf, pine seedlings, Christmas trees, and ornamentals. Triadimefon is classified as a demethylation inhibitor ( DMI) that inhibits fungal sterol biosynthesis. Current triadimefon formulations include granular, wettable powder, water soluble packets, liquid concentrate, and ready to use ( i. e., refined oil solution). Based on current label information, triadimefon is applied via ground spray, aerial spray, chemigation, and broadcast ( granular only) to apples, pears, raspberries, grapes, Christmas trees, ornamentals, pine seedlings, and turf ( golf course, residential, commercial, and recreational). Additionally, triadimefon is used as a post harvest dip fungicide for pineapples and as a seed piece treatment prior to planting. The post harvest dip use does not lead to environmental exposure and is therefore not addressed in this assessment. The Agency currently does not have methods to address potential exposure to seed piece treatment and this use is not covered in this assessment. The major degradate, triadimenol ( which is also a registered seed treatment fungicide active ingredient), is formed via microbial degradation in the soil subsurface as well as within plants following systemic uptake as a result of plant metabolism. Both triadimefon and triadimenol are evaluated in this assessment. 1,2,4 triazole is also formed as a degradate of triadimefon; however, this compound is not addressed in this risk assessment and will be examined in a future separate risk assessment by the Agency.

B. Potential Risks to Non target Organisms This is a national screening level ecological risk assessment for all labeled uses of triadimefon as per the Agency Use Closure Memo ( 26 July, 2004). The aquatic assessment involved Tier II modeling ( PRZM EXAMS) for scenarios representing all proposed triadimefon uses. Monitoring data were not considered in characterizing exposure and risk because national scale monitoring studies were not identified. Foliar residue levels were used to characterize terrestrial exposure using T REX ( v 1.1.2, USEPA, 2005). Tables 1 and 2 summarize the major conclusions and uncertainties of this assessment for terrestrial and aquatic receptors, respectively. The results of this screening level risk assessment suggest the potential for direct adverse chronic effects to birds and mammals at all application rates, scenarios, number of applications, and application intervals.

A one time application of 0.08 lb ai/ A for all crops ( e. g., only one application per year at this rate) would be required to achieve chronic dietary RQ values for birds that are lower than the Agency LOC of 1.0. This value is approximately 34 times lower than the maximum application rate for golf course turf of 2.7 lb ai/ A. The 2.7 lb ai/ A one time application rate would have to be reduced by approximately 97% in order to achieve an RQ value below the LOC. For mammals, the same single application rate would have to be reduced by 99% to 0.025 lb ai/ A for the chronic RQ values to be below the Agency LOC. Page 5 of 241 Additionally, application of triadimefon to golf course turf ( 26 applications per year, 2.7 lb ai/ A) suggests the potential for acute risk to birds, and acute risk to mammals may occur with application of triadimefon to all types of turf ( golf course, residential, commercial, and recreational) at all application rates, as well as Christmas trees. Acute effects to freshwater invertebrates may occur based on maximum application rates and number of applications to golf course turf ( 2.7 lb ai/ A). The results also suggest chronic risk to freshwater fish and invertebrates and listed non vascular aquatic plants based on triadimefon application to golf course turf ( maximum application rate, 26 applications per year), which is representative of a 12 month growing season.

For aquatic risks, it should be noted that there remains potential for chronic risk to freshwater invertebrates with only 6 golf course applications of triadimefon per year based on the Florida year round season scenario, and 11 applications per year based on the Pennsylvania 6 month season scenario ( 2.7 lb ai/ A; 14 day interval). Acute LOCs are exceeded with only 7 applications using the FL turf scenario. Potential for chronic risk to freshwater fish occurs with only 3 applications of triadimefon per year based on the FL scenario, and 6 applications per year based on the PA scenario ( 2.7 lb ai/ A; 14 day interval), and there remains potential for acute endangered species risk to aquatic non vascular plants with only 11 applications of triadimefon per year based on the FL scenario, and 5 applications per year based on the PA scenario ( 2.7 lb ai/ A; 14 day interval).

Risks to estuarine/ marine species, vascular aquatic plants, and terrestrial plants could not be determined due to the lack of toxicity data. The Endangered Species assessment is preliminary and is not complete, due to the identified data gaps as well as potential risk from exposure to the triadimefon degradate 1,2,4 triazole, which will be evaluated in a separate risk assessment by the Agency. Page 6 of 241 Table 1 Summary of Agency Level of Concern Exceedances for Terrestrial Organisms and Plants Risk Category Use: Application Rate Summarized Risk Characterization and Important Uncertainties Acute Risk to Birds Golf course turf: 2.7 lb ai/ A, 26 applications, 14d interval ( Florida)*** ( maximum use rate)

Golf course turf: 1.36 lb ai/ A, 26 applications, 14d interval ( average use rate) Acute restricted use, endangered species, and/ or acute risk LOCs are exceeded for birds that consume short grass, tall grass, broadleaf plants, and small insects for 12 month growing season golf course turf uses of triadimefon based on dietary based toxicity endpoints. Exposure concentrations based on application to golf course turf with a 6

month growing season ( same maximum application rate, 13 applications) did not result in exceedances. Additionally, a single application ( 2.7 lb ai/ A) of triadimefon to 12 month season golf course turf did not result in any exceedances. The golf course turf scenario is representative of a year round growing season, and 26 applications represents the maximum possible labeled use ( there are no labeling limitations on maximum number of applications per year).

Chronic Risk to Birds Apples & Pears: 0.25 lb ai/ A, 3 applications, 7d interval Raspberries: 0.125 lb ai/ A, 7 applications, 28d interval Grapes: 0.1875 lb ai/ A, 3 applications, 14d interval Golf course turf: 2.7 lb ai/ A, 1 application, 14d interval Golf course turf: 2.7 lb ai/ A, 26 applications, 14d interval Residential/ Commercial/ Recreational Turf: 1.36 lb ai/ A, 2 applications, 14d interval Christmas Trees: 0.25 lb ai/ A, 8 applications, 14d interval The chronic LOC is exceeded for all triadimefon uses, based on reproductive effects,

specifically, increase in eggs cracked and reductions in fertile eggs, eggs set, viable embryos, hatchlings, and 14 day old chick survivors Acute Risk to Mammals Golf course turf: 2.7 lb ai/ A and 1.36 lb ai/ A, 26 applications, 14d interval***

Golf course turf: 2.7 lb ai/ A and 1.36 lb ai/ A, 1 application,

14d interval**

Apples & Pears: 0.25 lb ai/ A, 3 applications, 7d interval Residential/ Commercial/ Recreational Turf: 1.36 lb ai/ A, 2 applications, 14d interval**

Christmas Trees: 0.25 lb ai/ A, 8 applications, 14d interval* Acute restricted use, listed species, and/ or acute risk LOCs are exceeded for mammals that consume short grass, tall grass, broadleaf plants, and small insects across most weight classes for all triadimefon uses except raspberries based on a dose based malespecific toxicity endpoint for triadimenol. Acute LOCs are exceeded even when nonconservative predicted mean residue values ( exposure concentrations) are used to assess risk. Table 1 Summary of Agency Level of Concern Exceedances for Terrestrial Organisms and Plants Risk Category Use: Application Rate Summarized Risk Characterization and Important Uncertainties Page 7 of 241 Chronic Risk to Mammals Apples: 0.25 lb ai/ A, 3 applications, 7d interval Raspberries: 0.125 lb ai/ A, 7 applications, 28d interval Grapes: 0.1875 lb ai/ A, 3 applications, 14d interval Golf course turf: 2.7 lb ai/ A and 1.36 lb ai/ A, 1 application,

14d interval Golf course turf: 2.7 lb ai/ A and 1.36 lb ai/ A, 26 applications, 14d interval Residential/ Commercial/ Recreational Turf: 1.36 lb ai/ A, 2 applications, 14d interval Christmas Trees: 0.25 lb ai/ A, 8 applications, 14d interval Based on dose based toxicity endpoints, the chronic LOC is exceeded for all use rates, for wild mammals that consume short grass, tall grass, broadleaf plants, and small insects,

and in some cases fruits, pods, large insects, and seeds. Additionally, the LOC is exceeded based on dietary based toxicity endpoints at all use rates for wild mammals that consume short grass, and for all uses except raspberries and grapes for species that consume tall grass, broadleaf plants, and small insects. Risk estimates are based on deleterious effects of triadimefon on pup weight and viability.

Terrestrial Plants Unknown There are no available terrestrial plant toxicity data; this is a major data gap and source of uncertainty in this assessment. Risk to terrestrial plants can not be precluded. A single study obtained through the ECOTOX database suggests potential toxicity to terrestrial plants.

Non target Insects None Based on acute contact toxicity studies on honeybees, triadimefon is classified as practically non toxic to these receptors.

* Exceeds acute listed species LOC for terrestrial animals.

** Exceeds acute listed species and acute restricted use LOC for terrestrial animals.

*** Exceeds acute listed species, acute restricted use and acute LOC for terrestrial animals. Page 8 of 241 Table 2 Summary of Agency Level of Concern Exceedances for Aquatic Organisms and Plants Risk Category Use: Application Rate Summarized Risk Characterization and Important Uncertainties Acute Risk to Freshwater Fish None The available data suggest that triadimefon is not likely to pose risk above LOCs to freshwater fish based on modeled acute exposure estimates for all uses.

Chronic Risk to Freshwater Fish Golf course turf: 2.7 lb ai/ A, 26 applications,

14d interval ( Florida) The chronic RQs based on ground spray applications of triadimefon to Florida golf course turf exceeds the LOC. Exposure concentrations based on application to Pennsylvania golf course turf ( same application rate, 13 applications) did not result in exceedances.

Additionally, a single application ( 2.7 lb ai/ A) of triadimefon to Florida golf course turf did not result in any exceedances. The Florida golf course turf scenario is representative of a year round growing season, and 26 applications represents the maximum possible labeled use ( there are no labeling limitations on maximum number of applications per year).

Acute Risk to Freshwater Invertebrates Golf course turf: 2.7 lb ai/ A and 1.36 lb ai/ A, 26 applications, 14d interval**

Golf course turf: 2.7 lb ai/ A and 1.36 lb ai/ A, 13 applications, 14d interval* The acute RQs based on ground spray applications of triadimefon to Florida and Pennsylvania golf course turf exceeds the LOC. Single applications ( 2.7 lb ai/ A) of triadimefon to Florida or Pennsylvania golf course turf did not result in any exceedances.

The Florida golf course turf scenario is representative of a year round growing season,

whereas the Pennsylvania turf scenario is representative of a more temperate climate with a 6 month season. The number of applications represents the maximum possible labeled use ( there are no labeling limitations on maximum number of applications per year).

Chronic Risk to Freshwater Invertebrates Golf course turf: 2.7 lb ai/ A and 1.36 lb ai/ A, 26 applications, 14d interval ( Florida) The chronic RQs based on ground spray applications of triadimefon to Florida golf course turf exceeds the LOC. Exposure concentrations based on application to Pennsylvania golf course turf ( same application rate, 13 applications) did not result in exceedances.

Additionally, a single application ( 2.7 lb ai/ A) of triadimefon to Florida golf course turf did not result in any exceedances. The Florida golf course turf scenario is representative of a year round growing season, and 26 applications represents the maximum possible labeled use ( there are no labeling limitations on maximum number of applications per year).

Acute Risk to Estuarine/ Marine Fish Unknown Acute endpoints for esturaine/ marine fish can not be derived because toxicity data was not available. Risk to esturaine/ marine fish from acute exposure to triadimefon can not be precluded. This is a source of uncertainty in this assessment.

Chronic Risk to Estuarine/ Marine Fish Unknown Chronic endpoints for esturaine/ marine fish can not be derived because toxicity data was not available. Risk to esturaine/ marine fish from chronic exposure of triadimefon can not be precluded. This is a source of uncertainty in this assessment. Table 2 Summary of Agency Level of Concern Exceedances for Aquatic Organisms and Plants Risk Category Use: Application Rate Summarized Risk Characterization and Important Uncertainties Page 9 of 241 Acute Risk to Estuarine/ Marine Invertebrates Unknown Acute endpoints for esturaine/ marine invertebrates can not be derived because toxicity data was not available. Risk to esturaine/ marine fish from acute exposure to triadimefon can not be precluded. This is a source of uncertainty in this assessment.

Chronic Risk to Estuarine/ Marine Invertebrates Unknown Chronic endpoints for estuarine/ marine invertebrates can not be derived because toxicity data are not available. Risk to estuarine/ marine invertebrates from chronic exposure of triadimefon can not be precluded. This is a source of uncertainty in this assessment.

Acute Risk to Estuarine/ Marine Molluscs Unknown Acute endpoints for estuarine/ marine molluscs can not be derived because toxicity data was not available. Risk to esturaine/ marine molluscs from acute exposure to triadimefon can not be precluded. This is a source of uncertainty in this assessment.

Risk to Aquatic Vascular Plants Unknown There are no available aquatic vascular plant toxicity data; this is a major data gap and source of uncertainty in this assessment. Risk to aquatic vascular plants can not be precluded.

Risk to Aquatic Nonvascular Plants Golf course turf: 2.7 lb ai/ A, 26 applications,

14d interval Golf course turf: 2.7 lb ai/ A, 13 applications,

14d interval The RQs based on ground spray applications of triadimefon to Florida and Pennsylvania golf course turf exceeds the endangered aquatic plant LOC. Single applications ( 2.7 lb ai/ A) of triadimefon to Florida or Pennsylvania golf course turf did not result in any exceedances. The Florida golf course turf scenario is representative of a year round growing season, whereas the Pennsylvania turf scenario is representative of a more temperate climate with a 6 month season. The number of applications represents the maximum possible labeled use ( there are no labeling limitations on maximum number of applications per year).

* Exceeds acute listed species LOC for aquatics.

** Exceeds acute listed species and acute restricted use LOC for aquatics.

*** Exceeds acute listed species, acute restricted use and acute LOC for aquatics Page 10 of 241 C. Conclusions  Exposure Characterization Triadimefon applied to an agricultural field or turf will likely be exported off site to some extent, due to the moderate solubility, mobility, and persistence of this compound. In addition, the primary degradate, triadimenol, has characteristics that enable it to leach into the soil profile and into ground water. Thus, there are several routes by which triadimefon and triadimenol may be transported, the principle mechanisms being: runoff of dissolved triadimefon into nearby surface water bodies, erosion of particulate bound triadimefon from the application areas into surface waters, and leaching of the degradation product triadimenol into ground water ( which can ultimately be discharged into surface waters as baseflow). There may also be exposure to both aquatic and terrestrial organisms due to spray drift resulting from ground and aerial application of liquid triadimefon. Due to the mechanism of formation of triadimenol ( microbial soil degradation and plant metabolism), organisms may be exposed to this degradate through incidental soil ingestion and/ or plant consumption.

D. Conclusions  Effects Characterization Triadimefon and its degradate triadimenol are practically non toxic to honeybees, birds, and mammals on an acute exposure basis. Triadimefon and triadimenol are moderately to slightly toxic to freshwater fish and invertebrates on an acute exposure basis.

Triadimefon demonstrates chronic toxicity in mammals and birds. Chronic effects in bobwhite quail included an increase in number of eggs cracked and a decrease in fertile eggs, viable embryos, viable hatchlings, and 14 day old chicks. For mammals, chronic effects were limited to reductions in pup weight and pup viability. Triadimenol is considerably less toxic on a chronic basis than the parent triadimefon.

E. Uncertainties and Data Gaps The major data gap is the lack of estuarine/ marine organism, aquatic vascular plant, and terrestrial plant toxicity studies for both triadimefon and triadimenol. For triadimefon, the only registrantsubmitted plant study was on green alga ( Selanastrum capricornutum). Due to the estimated risk to listed non vascular plants based on this toxicity information, data on other aquatic plant species is necessary. Evaluation of the open literature through ECOTOX provided several terrestrial plant studies; however, the studies were not deemed acceptable for quantitative use in this risk assessment. One study from the ECOTOX database provided data that did suggest the potential for adverse effects of triadimefon exposure to non target terrestrial plants, but this data could not be used quantitatively. Registrant submitted data is required to further elucidate this potential risk.

The largest source of uncertainty in this risk assessment concerns the major degradate of triadimefon, triadimenol. Although this degradate is significantly less toxic to aquatic organisms than the parent, it is equally toxic to mammals and only slightly less toxic to birds. Therefore, terrestrial risk associated with both the parent and degradate must be considered. Current Agency methods to assess terrestrial exposure examine dietary ingestion foliar residues. Triadimenol is formed in the soil subsurface through microbial degradation and within the plant following vascular uptake, and these exposure routes are not quantitatively considered in this assessment. Therefore, it is possible that risk calculations are underestimated in that they do not account for exposure to triadimenol. Page 11 of 241 It must be noted that the risk assessment for listed species was conducted only for the parent compound and not any of the degradates of triadimefon. Until risk assessments are completed for triadimefon degradates of concern, the listed species risk assessment should be considered incomplete.

Although it is known from several studies that triadimenol is formed in plants as well as the soil subsurface, additional data is needed on the specific rates of formation, conditions under which triadimenol is most likely to form, and formation pathways. Page 12 of 241 II. PROBLEM FORMULATION The purpose of the ecological risk assessment ( ERA) of triadimefon is to assist the Agency in evaluating the actions needed, if any, to address ecological risks from currently registered labeled uses of triadimefon. The objectives of the current ERA were to identify current registered uses of triadimefon, identify potential exposure pathways and ecological receptors that are appropriate to consider for these uses, estimate exposure concentrations based on labeled uses, identify ecological effect endpoint values, and calculate and characterize risks to ecological receptors from the labeled uses. This screening level ERA follows the Agency's ecological risk assessment guidelines ( USEPA 1986, 2000a, b, c).

A. Stressor Source and Distribution 1. Source and Intensity The source and intensity of triadimefon analyzed in this assessment is based on current Section3 labels as defined in the Agency's Use Closure Memo ( 26 July, 2004). These uses and labels are discussed in detail in Section III. A. Expanded Use Characterization.

Triadimefon ( Bayleton ® ) is a broad spectrum, systemic fungicide that is used for the control of various fungal diseases in fruits, turf, pine seedlings, Christmas trees, and ornamentals. Formulations include granular ( 0.5%, 1.0%), wettable powder ( 25%, 50%), water soluble packets ( 25%, 50%), liquid concentrate, and ready to use. Triadimefon is applied to fruit crops and Christmas trees via ground spray and aerial spray. Additionally, triadimefon is used as a postharvest dip fungicide for pineapples and a seed piece pre plant dip treatment. The post harvest use does not lead to environmental exposure and is therefore not addressed in this assessment. Treatment of seed pieces could result in ecological exposure; however, the Agency currently does not have a method to address this exposure and it is therefore not considered quantitatively in this assessment. Liquid triadimefon formulations are applied to turf ( residential, commercial, and residential), ornamentals ( landscape and nursery), and golf course lawns by ground spray and chemigation. Granular triadimefon is only used for consumer residential lawns via broadcast application. The highest use rates for triadimefon occur on golf course turf, with an application rate of 2.7 lbs ai/ A, an application interval of 14 28 days, and no maximum number of applications. Average golf course use rates are 1.36 lb ai/ A with the same application interval ( 14 28 days). Triadimefon is used on food crops ( apples, pears, grapes, and raspberries) at considerably lower rates ( maximum application rate of 0.25 lb ai/ A; maximum yearly application of 0.88 lb ai/ A). The major triadimefon metabolite of concern is triadimenol, which is formed in the soil and within plant tissues and comprises ~ 75% of total soil residues 60 days following application. Triadimenol and triadimefon have approximately equal toxicities to terrestrial organisms, and triadimenol is significantly less toxic than triadimefon to aquatic species ( fish and invertebrates). 1,2,4 triazole is also formed as a degradate of triadimefon; however, this compound is not addressed in this risk assessment and will be examined in a future separate risk assessment by the Agency.

The main focus of this assessment is on the turf uses of triadimefon, since the largest LOC exceedances occurred with this use. Additionally, aquatic environment exposure is a major focus, due to the large runoff potential resulting from triadimefon use on golf courses, residential lawns, and other large turf areas. Page 13 of 241 Cl O N O N N Cl O N N N OH Triadimefon Triadimenol microbial degradation plant metabolism 2. Physical and Chemical Properties Bayer Corporation is seeking reregistration for the use of triadimefon ( CAS No. 43121 43 3). A brief summary of the physical and chemical properties of triadimefon and known major degradates is provided here to support the decision on what exposure pathways were considered in this assessment, which are described in Section II. C. Conceptual Model. Fate properties needed for the assessment and the sources which were examined for this data are described in Section II. E. Analysis Plan with the detailed analysis of fate properties provided in Section III. B Exposure Characterization.

The chemical structure of triadimefon is provided in Figure 1. Physical and chemical properties of triadimefon are listed in tabular format below. The physical properties of triadimefon are characterized by its moderate solubility, moderate mobility, and relative persistence ( especially of the degradation product triadimenol). The primary metabolites of triadimefon are triadimenol and triazole, which make up approximately 75 and 15 percent ( respectively) of total residues after 60 days. Triadimenol is formed via microbial degradation in the soil subsurface and within the plant ( via plant metabolism) following systemic uptake.

Figure 1. Chemical structure of triadimefon and its major degradate triadimenol Common Name: Bayleton ®

Chemical Name: 1( 4 chlorophenoxy) 3,3 dimethyl 1( 1,2,4 triazol 1 yl) 2 butanone CAS No.: 43121 43 3 PC Code: 109901 Molecular Formula: C 14 H 16 ClN 3 O 2 Molecular Weight: 293.7 Melting Point: 82 N C Vapor Pressure: 7.6 x 10 7 mm Hg Water Solubility: 70 ppm Henry's Law Constant: 1.15 x 10 7 atm m3/ mol Octanol Water Partition Coefficient: 2.77 Formulations: granular ( 0.5%, 1.0%), wettable powder ( 25%, 50%), water soluble packets ( 25%, 50%), liquid concentrate, and ready to use Page 14 of 241 3. Mode of Action Triadimefon belongs to the class of demethylation inhibitory fungicides ( DMI), which inhibit the C14 demethylation step within fungal sterol biosynthesis. It is a broad spectrum, systemic fungicide that is used to control brown patch, dollarspot, snow mold, summer patch, powdery mildew, rust, anthracnose, and red thread diseases on a variety of crops.

4. Overview of Pesticide Usage Triadimefon is intended for use as a fungicide on pears, apples, raspberries, pinepples, and grapes, as well as pine ( seedlings and nurseries), Christmas trees, turf ( golf course, residential, commercial, and recreational), and ornamentals. The maximum use rates for triadimefon liquid formulations applied via ground spray range from 0.25 lb ai/ A ( 3 applications/ year, 7 day intervals) for apples and pears to 2.7 lb ai/ A ( 14 28 day interval, no maximum number of applications) for golf course turf. Triadimefon is also applied via aerial spray to Christmas trees at a rate of 0.25 lb ai/ A ( 8 applications, 14 day intervals) ornamentals at a rate of 0.5 lb ai/ A ( 4 applications, 14 day intervals). Triadimefon is also applied to apples, pears, and grapes via aerial spray at the same rates mentioned above for ground spray. Granular triadimefon is applied to lawns and turf ( excluding golf courses) at a rate of 1.3 lb ai/ A ( 30 day intervals, 2 applications). The common use rate for triadimefon on golf course turf is 1.36 lb ai/ A ( 14 28 day interval, no maximum number of applications). No further information on average triadimefon use rates is available at this time, and therefore maximum labeled use rates were used in this risk assessment for all other applications. For a complete list of specific uses and use rates, refer to Table 6.

B. Receptors 1. Ecological Effects Each assessment endpoint requires one or more " measures of ecological effect," which are defined as changes in the attributes of an assessment endpoint itself or changes in a surrogate entity or attribute in response to pesticide exposure. Ecological measurement endpoints for the screening level risk assessment are based on a suite of registrant submitted toxicity studies.

Toxicity studies used in the risk assessment are usually performed on a limited number of organisms in the following broad groupings:

° Birds ( mallard duck and bobwhite quail) used as surrogate species for terrestrialphase amphibians and reptiles ° Mammals ( laboratory rat) ° Freshwater fish ( bluegill sunfish and rainbow trout) used as a surrogate for aquatic phase amphibians ° Freshwater invertebrates ( water flea  Daphnia magna) ° Estuarine/ marine fish ( sheepshead minnow) ° Estuarine/ marine invertebrates ( Eastern oyster and mysid shrimp) ° Terrestrial plants ( corn, onion, ryegrass, wheat, buckwheat, cucumber, soybean, sunflower, tomato, and turnip) ° Algae and aquatic plants ( algae, diatoms, and duckweed) Page 15 of 241 ° Pollinators ( honeybee  Apis mellifera)

Within each of these very broad taxonomic groups, an acute and/ or chronic endpoint is selected from the available test data. Additional ecological effects data are available for the major metabolite of triadimefon, triadimenol. Toxicity data for the are available for the 1,2,4 triazole degradate; however, this compound is not addressed in this risk assessment and will be examined in a future separate risk assessment by the Agency.

Toxicity testing reported in this section does not represent all species of birds, mammals, or aquatic organisms. Only a few surrogate species for both freshwater fish and birds are used to represent all freshwater fish ( 2000+) and bird ( 680+) species in the United States. Mammalian acute studies are usually limited to Norway rat or New Zealand rabbit or the house mouse. Estuarine/ marine testing is usually limited to a crustacean, a mollusk, and a fish. Also, neither reptiles nor amphibians are tested. The risk assessment assumes that avian and reptilian toxicities are similar. The same assumption is used for fish and amphibians.

A complete discussion of all toxicity data available for this risk assessment and the resulting measurement endpoints selected for each taxonomic group are included in Appendix C. A summary of the assessment and measurement endpoints selected to characterize potential ecological risks associated with exposure to triadimefon and its metabolites is provided in Table 3.

2. Ecosystems at Risk Ecosystems potentially at risk are expressed in terms of the selected assessment endpoints. The typical assessment endpoints for screening level pesticide ecological risks are reduced survival, and reproduction and growth impairment for both aquatic and terrestrial animal species. Aquatic animal species of potential concern include freshwater fish and invertebrates, estuarine/ marine fish and invertebrates, and amphibians. Terrestrial animal species of potential concern include birds, mammals, reptiles, terrestrial phase amphibians, beneficial insects, and earthworms. For both aquatic and terrestrial animal species, direct acute and direct chronic exposures are considered. In order to protect threatened and endangered species, all assessment endpoints are measured at the individual level. Although all endpoints are measured at the individual level, they provide insight about risks at higher levels of biological organization ( e. g. populations and communities). For example, pesticide effects on individual survivorship have important implications for both population rates of increase and habitat carrying capacity.

For terrestrial and semi aquatic plants, the screening assessment endpoint is the perpetuation of populations of non target species ( crops and non crop plant species). Existing testing requirements have the capacity to evaluate emergence of seedlings and vegetative vigor. Although it is recognized that the endpoints of seedling emergence and vegetative vigor may not address all terrestrial and semi aquatic plant life cycle components, it is assumed that impacts at emergence and in active growth have the potential to affect individual competitive ability and reproductive success. Page 16 of 241 For aquatic plants, the assessment endpoint is the maintenance and growth of standing crop or biomass. Measurement endpoints for this assessment endpoint focus on algal and vascular plant ( i. e., duckweed) growth rates and biomass measurements.

The ecological relevance of selecting the above mentioned assessment endpoints is as follows: 1) complete exposure pathways exist for these receptors; 2) the receptors may be potentially sensitive to pesticides in affected media and in residues on plants, seeds, and insects; and 3) the receptors could potentially inhabit areas where pesticides are applied, or areas where runoff and/ or spray drift may impact the sites because suitable habitat is available.

C. Conceptual Model A conceptual model ( CM), which summarizes graphically the results of the problem formulation for evaluating risks to ecological receptors following application either liquid or granular triadimefon ( via aerial and ground application) to agricultural fields, Christmas tree farms, turf, and ornamentals is provided in Figures 2 and 3. The CMs are working hypotheses about how triadimefon and its metabolites are likely to reach ( i. e., exposure pathways) and affect ecological entities ( i. e., attribute changes) of concern on and adjacent to a treated area. In order for a pesticide stressor to pose an ecological risk, it must reach an ecological receptor in biologically significant concentrations. The CMs outline specifically which measures of exposure, ecological receptors, and measures of effects or measurement endpoints will be used to estimate risks from proposed reregistration uses of triadimefon.

Triadimefon is used on agricultural lands located in a wide diversity of eAcceptablegions and habitats spanning the continental United States. The wide diversity of land forms and vegetation types across triadimefon use areas also provides for a large diversity of mammals, birds, reptiles, amphibians, terrestrial invertebrates, freshwater and estuarine/ marine fish and invertebrates, and terrestrial and aquatic plants that could potentially be exposed.

1. Terrestrial Environment a. Liquid Applications Following spray ( ground or aerial) application of liquid triadimefon, terrestrial wildlife ( birds, mammals, reptiles, and terrestrial phase amphibians) may be exposed via ingestion of residues present on food items ( Figure 2). Wildlife exposure could also result from a number of other exposure pathways and wildlife actions or behaviors including dermal uptake via direct contact of skin with the soil residues, contact with residues in puddles present on the field at the time of application or formed after a rain event, or ingestion of water from residues in puddles. Triadimefon is expected to be readily absorbed by plant roots from the soil and transported through a plant via plant fluids following application based on physicochemical properties and mechanism of action. Triadimenol is formed within the plant tissues as a result of plant metabolism, as well as within the soil subsurface as a result of microbial degradation. Spray drift resulting from aerial application of triadimefon may result in upland vegetation exposure and subsequent uptake by these plant species. Exposure to the major triadimefon degradate, triadimenol, may also occur via the same basic exposure pathways. However, since triadimenol is Page 17 of 241 formed mostly in the shallow soil subsurface and within the plant itself, surface exposure to triadimenol is probably less frequent than surface exposure to parent. Nevertheless, rooting within shallow soil and plant consumption may still lead to significant triadimenol exposure.

b. Granular Applications Immediately following granular application of triadimefon to lawns and turf, granules are expected to be available at the surface. Terrestrial wildlife exposure could result from mistakenly ingesting granules as seeds, ingesting them as part of incidental soil ingestion while foraging for food, or ingesting food items with granular residue ( either soil or actual granules), such as earthworms. Further exposure may also occur via ingestion of residues ( as a result of foliar uptake), inhalation of granular dust particulates, dermal uptake via direct contact of skin with the granules or soil residues, or contact with residues in puddles present on the area at the time of application. Currently, terrestrial wildlife exposure is estimated via the amount of toxicant per unit area in a screening level risk assessment for granular pesticides ( LD 50 / ft2 index). This index was developed considering these other routes of exposure; however, they are not separately accounted for in the index calculations. Following the dissolution of the triadimefon granules, exposure could also occur via the pathways described for liquid application above ( Figure 3). As with the liquid applications, exposure to the degradate, triadimenol, could also occur. c. Receptors of Concern Ecological receptors of concern identified for consideration in the terrestrial environment include primary producers, represented by both upland and wetland/ riparian vegetation, and primary and secondary consumers, both vertebrates and invertebrates, representing common ecological functional feeding groups ( i. e., herbivores and insectivores). Herbivores as used here include animals that feed on foliage ( stems and leaves), seeds, and/ or fruit; the term granivore is sometimes used to identify animals that feed primarily on seeds. Omnivores ( i. e., consumers that feed on a mixed diet of animals and plants) are also potentially exposed but are not specifically included in the receptor list for a screening level risk assessment because exposure concentrations and risk levels will fall between the exclusive feeding groups. Food chain transfer through biomagnification or bioaccumulation of triadimefon to higher trophic level predators ( e. g., carnivores) is not considered as a viable significant exposure pathway since triadimefon's octanolwater partition coefficient and bioconcentration factors are low. A low octanol water partition coefficient indicates that the chemical has low affinity for fatty tissues and is therefore unlikely to bioconcentrate in organisms ( e. g., has a low bioconcentration factor, BCF).

d. Risk Hypotheses Based on the sources/ transport pathways, exposure media, and potential receptors of concern, specific questions or risk hypotheses are formulated to characterize direct effects of triadimefon application to terrestrial organisms.

Birds and mammals are subject to reduced survival or reduced reproductive ability when exposed to triadimefon and/ or its metabolites as a result of labeled uses.

Upland and riparian/ wetland plants are subject to adverse effects ( reduced survival) when Page 18 of 241 exposed to triadimefon and/ or its metabolites as a result of labeled uses.

2. Aquatic Environment a. Liquid Applications Following spray ( ground or aerial) application of liquid triadimefon, freshwater and estuarine/ marine fish, freshwater and estuarine/ marine invertebrates, aquatic phase amphibians, and aquatic plants may be exposed through runoff from agricultural fields and spray drift. Additionally, the leaching of triadimefon into the groundwater may subsequently lead to aquatic organism exposure. Exposure to the triadimefon degradate triadimenol may occur via the same mechanisms described above ( Figure 2). In particular, exposure to triadimenol via groundwater discharge into streams and other surface water bodies may be substantial, in light of its greater persistence in anaerobic environments ( common to groundwater) relative to the parent and its higher overall propensity to infiltrate the subsurface ( and reach groundwater).

b. Granular Applications Direct application of triadimefon to streams, lakes, and ponds is forbidden by product labels. However, following a rain event, granular triadimefon may reach aquatic environments from areas of application ( turf) in sheet and channel flow runoff since it is readily water soluble and moderately persistent in terrestrial environments. Freshwater and estuarine/ marine fish, freshwater and estuarine/ marine invertebrates, aquatic phase amphibians, and aquatic plants may be exposed to triadimefon and triadimenol through runoff following granular application ( Figure 3).

c. Receptors of Concern For the aquatic ecosystem ecological receptors include all aquatic life ( fish, amphibians, invertebrates, plants) and those terrestrial animals ( e. g., birds and mammals) that consume aquatic organisms. d. Risk Hypotheses Based on the sources/ transport pathways, exposure media, and potential receptors of concern, specific questions or risk hypotheses are formulated to characterize direct effects of triadimefon application to aquatic organisms.

Aquatic fish and invertebrates are subject to adverse effects such as reduced survival and reduced reproduction when exposed to triadimefon and/ or its metabolites as a result of labeled use.

Aquatic plants are subject to adverse effects ( reduced survival) when exposed to triadimefon and/ or its metabolites as a result of labeled use.

D. Analysis Plan This document includes an assessment of risks to aquatic and terrestrial animals and plants resulting from the use of liquid triadimefon on apples, pears, grapes, raspberries, turf ( residential, commercial, and residential), ornamentals ( landscape and nursery), and golf course lawns. Risks Page 19 of 241 resulting from the use of granular triadimefon on residential lawns is also examined.

1. Preliminary Identification of Data Gaps and Uncertainties The major data gap is the lack of estuarine/ marine organisms, aquatic vascular plant, and terrestrial plant toxicity studies. For triadimefon, the only registrant submitted plant study was on green alga ( Selanastrum capricornutum). Due to the estimated risk to listed non vascular plants based on this toxicity information, data on other aquatic plant species is necessary. Evaluation of the open literature through ECOTOX provided several terrestrial plant studies; however, the studies were not deemed acceptable for use in this risk assessment, either quantitatively or qualitatively ( see Table 19).

Major data gaps include: ° § 123 2: Aquatic vascular plant growth ( triadimefon and triadimenol) ° § 72 3a: Estuarine/ Marine Fish LC 50 ( triadimefon and triadimenol) ° § 72 3b: Estuarine/ Marine Mollusk EC 50 ( triadimefon and triadimenol) ° § 72 3c: Estuarine/ Marine Shrimp EC 50 ( triadimefon and triadimenol) ° § 123 1a: Seedling Emergence ( triadimefon and triadimenol) ° § 123 1b: Vegetative Vigor ( triadimefon and triadimenol)

° Information regarding the formation of the degradate triadimenol ( rate, conditions, and pathways of formation)

Although it is known from several studies that triadimenol is formed in plants as well as the soil subsurface, additional data is needed on the specific rates of formation, conditions under which triadimenol is most likely to form, and formation pathways. 1,2,4 triazole is also formed as a degradate of triadimefon; however, this compound is not addressed in this risk assessment and will be examined in a future separate risk assessment by the Agency.

2. Measures to Evaluate Risk Hypotheses a. Measures of Exposure i. Terrestrial Environment Due to the approximate equal toxicity of triadimefon and its major metabolite, triadimenol, to terrestrial organisms, this assessment assumes exposure to both the parent triadimefon as well as triadimenol. Terrestrial wildlife exposure estimates are typically calculated for birds and mammals, emphasizing a dietary exposure route for the uptake of pesticide active ingredients. These exposures are considered surrogates for terrestrial phase amphibians and reptiles. For terrestrial wildlife exposure, OPP primarily looks at the residues of pesticides on food items and assumes that organisms are exposed to a single pesticide residue in a given exposure scenario. The residue estimates are based on a nomogram that relates food item residues to pesticide application rate ( Fletcher et al., 1994). The first tier of the nomogram uses the maximum predicted residues. Subsequent refinements may consider the mean residue values. However, maximum body concentration is converted to daily oral dose based on fractions of body weight consumed daily as estimated from mammalian allometric relationships in EPA's Wildlife Exposure Page 20 of 241 Factors Handbook. In all screening level assessments, the organisms are assumed to consume 100% of their diet as one food type.

Triadimenol is formed via microbial degradation in the soil subsurface and through plant metabolism following uptake. Our current estimation of pesticide concentrations in wildlife food items following spray applications focuses on quantifying possible dietary ingestion of residues on vegetative matter and insects and not on ingestion of residues within the plant material. Therefore, terrestrial exposure to triadimenol is not quantitatively evaluated in this assessment. However, terrestrial organism exposure to triadimenol is likely, and although not quantitatively evaluated, must be considered in the overall determination of risk.

Terrestrial plant exposure is calculated based on spray drift resulting from ground or aerial spray application, assuming 1% and 5% drift, respectively. Additionally, wetland plant exposure is determined via both spray drift and runoff calculations.

Granular applications of pesticides require different estimation methods to assess exposure. Triadimefon is applied in granular form to residential turf and is not incorporated into the soil. Ingestion of the granules left on the soil/ turf surface is considered the major route of exposure to terrestrial organisms, and risk is calculated using the LD 50 / ft2 index ( Felthousen et al., 1977). Terrestrial plant exposure following granular application can occur through uptake of the pesticide; however, this exposure route is not quantitatively considered in this assessment.

ii. Aquatic Environment This assessment assumes exposure to both the parent triadimefon as well as triadimenol for aquatic organisms. OPP generally uses computer simulation models to estimate exposure of aquatic organisms, such as plants, fish, aquatic phase amphibians, and invertebrates, to a pesticide. These models calculate estimated environmental concentrations ( EECs) in surface water using laboratory data that describe the rate at which the pesticide breaks down and how it moves into the environment. The Pesticide Root Zone Model and Exposure Analysis Modeling System ( PRZM EXAMS) model is initially used to calculate high end estimates of surface water concentrations of pesticide in a generic pond. This model was used to generate EECs of total triadimefon ( parent + triadimenol) in surface water. The User's Manual and PRZM EXAMS model description can be consulted for additional information at: www. epa. gov/ offefed1/ models/ water/ index. htm. No EECs are generated in instances where no toxicity was observed at concentrations above the active ingredient's water solubility or at or above the recommended limit concentration for a particular type of study.

Aquatic exposure resulting from food crop triadimefon use was modeled using the following scenarios: PA, NC, and OR apple, OR berry, CA and NY grape, CA fruit, OR Christmas tree, FL turf, and PA turf. The three apple scenarios are representative of both apple and pear triadimefon application in three different geographical regions of the country where the chemical may be applied. The CA fruit scenario is representative of all non citrus crops grown in the Central Valley. Based on use information from BEAD ( Table 7), the majority of triadimefon use on Page 21 of 241 pears occurs in CA, WA, and OR. The OR berry scenario is representative of the use of triadimefon on raspberry crops, although it is noted, based on BEAD information ( Table 7) that 100% of the triadimefon use on raspberries occurs in California. Oregon is probably the best surrogate scenario for Northern California raspberry production because of similarities in weather conditions and soil types. The CA and NY grape scenarios are limited to two regions, whereas grapes are grown in the midwest ( IN, MO, MI, OH), south ( AR, NC, TN, VA), northeast ( NY, PA), and west ( CA, OR, WA). The same limitations exist for the OR Christmas tree scenario, with potential triadimefon use on this commodity occurring in numerous geographical regions of the country. Despite these modeling limitations, the scenarios chosen to model potential triadimefon exposure in the aquatic environment are considered adequately representative of the potential uses. Seasonal application timing varied depending on climate and pest season.

The two turf scenarios represent a temperate climate with a single growing season ( May September; PA), as well as a warm, humid climate with a year round growing season ( FL). These two scenarios generally cover the climatological range under which triadimefon may be used on turf. It is important to note that triadimefon turf use includes golf courses, as well as other commercial, residential, and recreational applications, and therefore the PRZM EXAMS turf scenarios may over or under represent potential aquatic triadimefon exposure from these other applications. Page 22 of 241 Spray ( ground or aerial) Application of Triademifon Leaching ( infiltration/ percolation)

Upland Soil/ Foliage Riparian/

Wetland Soil/ Foliage Water Body Groundwater Ingestion Direct contact/

Root Uptake Direct contact/

Root Uptake Gill/ Integument Uptake Terrestrial Vertebrates Birds, Mammals,

Reptiles, Terrestrial Phase Amphibians Plant population Reduced population growth Terrestrial Upland Plants Wetland/

Riparian Plants Aquatic invertebrates Aquatic vertebrates Aquatic plants Individual vertebrates/

Invertebrates Reduced survival Reduced growth Reduced reproduction Individual plants Seedling emergence Vegetative vigor Individual animals Reduced survival Reduced growth Reduced reproduction Runoff/ Erosion Terrestrial Food Residues Direct Deposition Spray Drift Triadimenol Degradate Figure 2. Ecological conceptual exposure model for spray ( ground or aerial) application of liquid triadimefon Page 23 of 241 Direct Granular Triadimefon Application to Turf Leaching ( infiltration/ percolation)

Upland soil Riparian/

Wetland Soil Water Body Groundwater Ingestion Direct contact/

Root Uptake Direct contact/

Root Uptake Gill/ Integument Uptake Terrestrial Vertebrates Birds, Mammals,

Reptiles, Terrestrial Phase Amphibians Plant population Reduced population growth Terrestrial Upland Plants Wetland/

Riparian Plants Aquatic invertebrates Aquatic vertebrates Aquatic plants Individual vertebrates/

Invertebrates Reduced survival Reduced growth Reduced reproduction Individual plants Seedling emergence Vegetative vigor Individual animals Reduced survival Reduced growth Reduced reproduction Triadimenol Degradate Runoff/ Erosion Figure 3. Ecological conceptual exposure model for granular application of triadimefon to turf Page 24 of 241 b. Measures of Effect Assessment endpoints are defined as " explicit expressions of the actual environmental value that is to be protected." Two criteria are used to select the appropriate ecological assessment endpoints: 1) identification of the valued attributes of the environment that are considered to be at risk, and 2) the operational definition of assessment endpoints in terms of an ecological entity ( i. e., a community of fish and aquatic invertebrates) and its attributes ( i. e., survival and reproduction). Therefore, the selection of assessment endpoints is based on valued entities ( i. e., ecological receptors), the ecosystems potentially at risk, the migration pathways of pesticides, and the routes by which ecological receptors are exposed to pesticide related contamination. The selection of clearly defined assessment endpoints is important because they provide direction and boundaries in the risk assessment for addressing risk management issues of concern.

Aquatic and terrestrial non target toxicity endpoints ( animals and plants) are provided by the acute and, where appropriate, chronic toxicity data. These toxicity endpoints are compared with the environmental concentrations of triadimefon, based on fate properties, exposure method, etc. For this assessment, the most sensitive toxicity endpoints for each surrogate taxa ( ie. freshwater fish and invertebrates, estuarine/ marine fish and invertebrates, aquatic plants, terrestrial plants, birds, and mammals) for both the parent ( triadimefon) and its major metabolite ( triadimenol) will be used in Risk Quotient ( RQ) calculation with various exposure values ( see above). Terrestrial risk quotients for granular use will be calculated using the LD 50 per square foot index as per Felthousen ( 1977) and Urban and Cook ( 1986).

An acute and chronic endpoint is selected from the available test data, as the data sets allow. Additional ecological effects data were available for triadimefon and its major metabolite, triadimenol, and were incorporated into the risk characterization as other lines of evidence. Endpoints used in this assessment are listed in Table 3. Page 25 of 241 Table 3. Summary of assessment and measurement endpoints used in calculations Assessment Endpoint Chemical Measurement Endpoint 1. Survival, reproduction, and growth of birds Triadimefon Acute oral bobwhite quail LD50 > 2000= mg/ kg Subacute dietary bobwhite quail LC50 = 8392 ppm Reproductive toxicity bobquite quail NOAEL = 20 ppm Triadimenol Acute oral bobwhite quail LD50 > 2000 mg/ kg Reproductive toxicity mallard duck NOAEL = 100 ppm 2. Survival, reproduction, and growth of mammals Triadimefon Acute oral rat LD50 = 1090 mg/ kg ( females) Chronic 2 generation rat reproduction NOAEL = 50 ppm Triadimenol Acute oral rat LD50 = 689 mg/ kg ( males) Chronic 2 generation rat reproduction NOAEL = 100 ppm 3. Survival and reproduction of freshwater fish and invertebrates Triadimefon Acute rainbow trout LC50 = 4.1 ppm Chronic rainbow trout NOAEL = 0.041 ppm Acute daphnid LC50 = 1.6 ppm Chronic daphid NOAEL = 0.052 ppm Triadimenol Acute rainbow trout LC50 = 14 ppm Acute daphnid LC50  2.5 ppm Chronic daphnid NOAEL = 0.1 ppm 4. Survival and reproduction of estuarine/ marine fish and invertebrates Triadimefon NO DATA Triadimenol NO DATA 5. Perpetuation of nontarget terrestrial plants ( crops and non crop species) Triadimefon NO DATA Triadimenol NO DATA 6. Survival of beneficial insect populations Triadimefon Honey bee ( acute contact basis) LD50 > 25 ug/ bee 7. Maintenance and growth of aquatic plants from standing crop or biomass Triadimefon Green algae EC50 = 1.71 ppm Triadimenol Green algae EC50 = 3.7 ppm LD 50 = Lethal dose to 50% of test population NOAEC = No observed adverse effect concentration LOAEC = Lowest observed adverse effect concentration LC 50 = Lethal concentration to 50% of the test population EC 50 / EC 25 = Effect concentration to 50%/ 25% of the test population 3. Risk Quotients and Levels of Concern Risk characterization integrates exposure and ecotoxicity data to evaluate the likelihood of adverse effects. For ecological effects, the Agency accomplishes this integration using the quotient risk method. Risk quotients ( RQs) are calculated by dividing exposure estimates by acute and chronic ecotoxicity values.

RQ = EXPOSURE / TOXICITY RQs are then compared to the Office of Pesticide Program's levels of concern ( LOCs) to assess Page 26 of 241 potential risk to non target organisms and the need to consider regulatory action. Calculation of an RQ that exceeds the LOC indicates that a particular pesticide use poses a presumed risk to non target organisms. LOCs currently address the following categories of presumed risk: ° acute  potential for acute risk is high and regulatory action beyond restricted use classification may be warranted ° acute restricted  the potential for acute risk is high, but may be mitigated through restricted use classification ° acute endangered species  threatened and endangered species may be adversely affected ° chronic risk  the potential for chronic risk is high and regulatory action may be warranted. The ecotoxicity values used in the acute and chronic risk quotients are endpoints derived from required laboratory toxicity studies. Ecotoxicity endpoints derived from short term laboratory studies that assess acute effects are: ° LC 50  fish and birds ° LD 50  birds and mammals ° EC 50  aquatic plants and aquatic invertebrates ° EC 25  terrestrial plants The NOAEC ( No Observable Adverse Effect Concentration) is the endpoint used to assess chronic effects. Table 4 lists LOCs and gives formulas for calculating RQs and LOCs for various risk presumptions.

Table 4. Formulas for RQ calculations and LOC used for risk assessment of triadimefon Risk Presumption RQ LOC Birds and Wild Mammals Acute Risk EEC1/ LC50 or LD50/ ft2* or LD50/ day2 0.5 Acute Restricted Use EEC/ LC50 or LD50/ ft2 or LD50/ day ( or LD50< 50 mg/ kg) 0.2 Acute Endangered Species EEC/ LC50 or LD50/ ft2 or LD50/ day 0.1 Chronic Risk EEC/ NOAEC5 1.0 Aquatic Animals Acute Risk EEC3/ LC50 or EC50 0.5 Acute Restricted Use EEC/ LC50 or EC50 0.1 Acute Endangered Species EEC/ LC50 or EC50 0.05 Chronic Risk EEC/ NOAEC 1.0 Risk Presumption RQ LOC Page 27 of 241 Terrestrial and Plants Inhabiting Semi Aquatic Areas Acute Risk EEC4/ EC25 1.0 Acute Endangered Use EEC/ EC05 or NOAEC 1.0 Aquatic Plants Acute Risk EEC3/ EC50 1.0 Acute Endangered Species EEC/ EC05 or NOAEC 1.0 * mg/ ft2 1Abbreviation for Estimate Environmental Concentration ( ppm) on avian/ mammalian food items 2 mg of toxicant consumed/ day 3 EEC = ppm or ppb in water 4 EEC = lbs ai/ A 5 No chronic risk was calculated for terrestrial animals based on the LD50/ ft2 index for granular uses Page 28 of 241 III. ANALYSIS A. Expanded Use Characterization Triadimefon is a broad spectrum fungicide used to treat such diseases as powdery mildew, dollar spot, copper spot, rusts, black rot, bunch rot, and downy mildew ( for complete crop/ disease list, see Table 5). It is applied to pears, apples, raspberries, and grapes, as well as pine ( seedlings and nurseries), Christmas trees, turf ( golf course, residential, commercial, and recreational), and ornamentals. Additionally, it is used as a post harvest dip treatment and a pre plant seed piece treatment on pineapples.

Triadimefon is sold as granular ( 0.5%, 1.0%), wettable powder ( 25%, 50%), water soluble packets ( 25%, 50%), liquid concentrate, and ready to use formulations. Liquid formulations are applied via ground spray, aerial spray, and chemigation. Granular triadimefon is specified for use only on residential turf, and is applied via broadcast without soil incorporation. Diseases targeted by triadimefon are presented in Table 5. A list of current EPA registration numbers, uses, maximum application rates, and application methods based on the Agency Use Closure Memo ( 26 July, 2004) is available in Table 6. Risks were not calculated for pineapple ( seed piece treatment and post harvest dip), pine seedlings, and ornamentals. There is currently no Agency method of quantitatively assessing exposure to seed pieces treated with pesticide, and no ecological exposure is likely to result from post harvest pineapple dip treatment. Pine seedling and ornamental uses of triadimefon are also not assessed individually because the application rates to these crops fall within the current range of assessed uses. Additionally, there are no currently available aquatic exposure model scenarios available for these uses.

Of the triadimefon uses, the highest number of pounds of triadimefon used per year is on turf and ornamentals followed by grapes and apples ( Table 6). Based on the rate and quantitative use analysis, it was decided to focus the risk analysis on the maximum labeled rates for all crop uses except for pineapple post harvest and seed piece treatment, pine seedling and nursery uses, and ornamentals ( landscape and nurseries). Because a single application rate on turf use is approximately 10x higher than for food use crops and the number of applications in a year is only limited by the requirement of a two week interval between applications, additional focus was placed on determining risk for alternative turf applications.

Table 5. Triadimefon target diseases Crop Disease( s)

Apple cedar apple rust powdery mildew Pear powdery mildew Grapes powdery mildew black rot bunch rot dead arm downy mildew Crop Disease( s)

Page 29 of 241 Pineapple ( pre plant seed piece treatment and post harvest) pineapple butt rot fresh fruit rot Raspberries powdery mildew Pine ( seedlings and nursery) pine rust fusiform rust Christmas trees needlecast rusts ( fusiform, gall) stem and cone tip blight Turf dollar spot copper spot powdery mildew corticium red thread rusts ( Puccinia spp.) brown patch anthracnose southern blight stripe smut fusarium blight summer patch zoysia patch gray snow mold pink snow mold Ornamentals flower blight leaf blight/ spots powdery mildew rusts tip blight Table 6. Triadimefon Maximum Labeled Use Rates Used in this Assessment CROP EPA LABEL # FORM MAX APP RATE ( lb ai/ A) MAX # OF APPS MIN APP INTERVAL ( days) MAX TOTAL APP/ SEASON ( lb ai/ A) APP METHOD( S)

Apple & Pear 264 737 432 1294 50% WP 0.25 3 7 0.75 ground spray aircraft Grapes 264 737 432 1294 50% WP 0.1875 3 14 0.5625 ground spray aircraft Raspberries 264 737 432 1294 50% WP 0.125 7 28 0.88 ground spray Christmas Trees 264 737 50% WP 0.25 8 14 2.0 ground spray aircraft Golf Course Turf* 829 289 0.88% FlC 2.7 NS 60 NS ground spray Page 30 of 241 432 1293 25% WP 2.7 NS 14 NS chemigation Ornamental s 432 1367 50% WP 0.5 4/ yr 14 2.0 chemigation aerial spray Lawns and Turf 432 1360 432 1367 50% WP 1.36 2 30 NS chemigation ground spray 28293 278 1% G 1.31 2 30 NS broadcast * Common use rates for golf course turf based on Use Closure Memo indicate an application of 1.36 lb ai/ A ( same interval and number of applications) WP = wettable powder FlC = flowable concentrate G = granular NS = not specified Table 7. Triadimefon typical state and crop use information ( BEAD Quantitative Usage Analysis, April 8, 2002)

Crop Acres Treated ( max) Total lbs applied/ yr ( max) Highest use states (%)

Raspberries 2000 2000 CA ( 100%)

Apples 38,000 8000 WA MI VA NY UT CA ( 70%)

Pears 8000 2000 OR WA CA ( 89%)

Grapes ( raisin) 3000 2000 CA ( 100%)

Grapes ( table) 10,000 3000 CA MI ( 95%)

Grapes ( wine) 17,000 3000 CA MI ( 92%)

Turf & Ornamentals NA 320,000 NA Pine, Christmas Trees, Pineapple NA NA NA TOTAL 78,000* 340,000

* not including turf and ornamental, pine, Christmas tree, or pineapple acreage B. Exposure Characterization 1. Environmental Fate and Transport Acceptable studies for triadimefon are available for all fate and transport guideline requirements; however, there are few studies on the triadimefon degradate triadimenol. Further studies must be performed on this toxic degradate to fully characterize total residue exposure. The status of the data requirements is described in Appendix A. Selected fate properties for triadimefon and triadimenol are summarized in Tables 8 and 9, respectively. Page 31 of 241 Table 8. Triadimefon fate and transport properties Property Value Reference Hydrolysis half life pH 4 pH 7 pH 9 stable stable stable MRID# 41922101 Aqueous photolysis half life 7.6 hours MRID# 42112901 & 41933601 Soil photolysis half life 30 days MRID# 42820401 Anaerobic soil half life 23.1 days MRID# 41686101 Aerobic soil metabolism half life ( All studies conducted at 20 degrees Celsius)* 5.6 days ( laboratory), multiplied by 3 ( single data source) = 16.8 days MRID# 41686102* & 42224104*

*( This study conducted at 25 B C)

Aerobic aquatic half life 33.6 days ( in the absence of data, 2X aerobic soil value) MRID# 41686102 Anaerobic aquatic half life 217 days MRID# 42401201 Field dissipation half life 417 days MRID# 42242701 Adsorption coefficient Koc 387 L/ kg oc MRID# 41616008 Bioconcentration factor ( BCF) 40x ( edible tissue) 134x ( non edible tissue) 77x ( whole organism) MRID# 41619901 Page 32 of 241 Table 9. Triadimenol fate and transport properties Property Value Reference Hydrolysis half life pH 4 pH 7 pH 9 stable stable stable EFGWB # 295, 296 Aqueous photolysis half life 1.5 days EFGWB # 295, 296 Soil photolysis half life stable EFGWB # 295, 296 Anaerobic soil half life stable MRID # 41686101 & 42401201 Aerobic soil metabolism half life ( All studies conducted at 20 degrees Celsius)* 744 days ( 3 x 248 days) MRID# 41686102* & 42224104*

*( This study conducted at 25 B C)

Aerobic aquatic half life 1488 days ( 2 x aerobic soil value) MRID # 41686102 Anaerobic aquatic half life stable MRID # 42401201 Adsorption coefficient Koc 365 L/ kg oc MRID # 41616008 ( averaged from 4 soils)

a. Persistence Triadimefon would seem to be capable of persisting and accumulating in a variety of environmental conditions. Moderate mobility and adsorption characteristics may allow it to leach to shallow soil depths, where it can persist for long periods under aerobic soil conditions typical of the vadose zone. Repeated annual treatments create the potential for accumulation within the shallow vadose zone. In addition, it is sufficiently mobile that it can enter groundwater ( especially via preferential flow), where it can remain fairly stable, particularly in shallow, oxic, unconfined aquifers. Overall, triadimefon is likely to be of greater concern for surface runoff issues, presenting less of a potential groundwater contamination problem because it typically does not penetrate deeply enough into the soil profile.

Triadimefon appears to undergo slow degradation in aerobic soil, with a field measured half life of 417 days for California soils ( MRID # 42242701). However, lab studies yielded a much shorter half life of 5.6 days. Nevertheless, detection of applied triadimefon in aerobic soils nearly 2 orders of magnitude longer than predicted from lab studies indicates that the lab studies failed to account for real world behavior of triadimefon. Typically, field dissipation rates in aerobic soil should be faster than lab rates for aerobic soil because presumably multiple degradation pathways are available in the field, whereas in lab studies single processes are isolated. Thus, long term contamination of the vadose zone is likely under repeated ( annual) applications, since the field ( aerobic) half life is greater than one year, allowing potential accumulation of contaminant to occur. Page 33 of 241 Considering the overall similarities in chemical characteristics, it might be expected that triadimenol would behave in a similar fashion to triadimefon, especially in regard to persistence. The most notable difference is that triadimenol appears to be more stable under anaerobic conditions. Once introduced into the saturated zone ( especially deep, confined aquifers) or other anaerobic environments ( e. g., wetlands) there is great potential for this compound to persist and accumulate. Combined with its formation primarily in the subsurface, the degradation product triadimenol is more likely to be of concern for groundwater than the parent triadimefon. Greater persistence in anaerobic conditions, greater leaching potential within the soil column, and consequently higher propensity for transmission into and through groundwater make triadimenol more likely to be transported long distances ( as groundwater can be discharged into surface water at some distance from the areas of application) and over longer time periods ( groundwater generally moves much more slowly than surface runoff and discharge is not limited to storm events). Thus, triadimenol is apt to be more persistent than parent triadimefon in most settings.

b. Mobility Both triadimefon and triadimenol are moderately soluble ( 70 ppm), and are therefore capable of being transported dissolved in water as surface runoff or as leachate to groundwater. Most triadimefon applications are already in liquid form, as aerial spray, ground spray, or chemigation. Broadcast granular applications are also allowed for residential turf applications. In all of these cases there is the potential for transport into groundwater ( via leaching through soil) and surface water ( as runoff or as baseflow contributions to stream water). Soil column leaching studies ( MRID # 41616008 & 42356601) indicated that triadimefon did move down through the soil profile; parent compound was detected up to a depth of 20 cm in sand and silt loam soils and > 30 cm in sandy loam and clay loam. Triadimefon field dissipation studies ( MRID # 42242701, 41686104, & 41686103) revealed detectable levels of triadimefon in the soil at depths up to 24 inches following single and multiple turfgrass applications. Triadimenol appears to be even more prone to leaching; it was detected at depths up to 48 inches. This may be due partly to its formation in the aerobic subsurface, where subsequent rain or irrigation events can leach it deeper into the soil. None of these studies, which evaluated constituents in soil porewater, measured or accounted for the likelihood of preferential flow ( into groundwater). Once within the saturated zone, there is little possibility of triadimenol degradation because of the persistence of the compound under these environmental conditions ( see Table 9 above).

Surface runoff issues are particularly salient to triadimefon usage for turf grass. Repeat applications ( as many as 26 per year according to label usage for golf course applications) of fairly large amounts create conditions where significant runoff into streams and ponds can occur. Although aqueous photolysis is relatively rapid ( half life = 7.6 hours) for triadimefon, runoff water is usually very turbid; therefore photolysis would be severely inhibited by the water's opacity ( in runoff, stream water receiving runoff, and other water bodies fed by storm flow). The impact of the toxic degradate triadimenol should be less important for runoff water, since it is primarily formed in the subsurface where there is less risk of influence on runoff. Page 34 of 241 2. Aquatic Resource Exposure Assessment Tier II Estimated Environmental Concentrations ( EECs) for triadimefon were estimated using EFED's aquatic models PRZM EXAMS ( EXposure Analysis Modeling System). PRZM is used to simulate pesticide transport as a result of runoff and erosion from an 10 ha agricultural field, and EXAMS considers environmental fate and transport of pesticides in surface water and predicts EECs in a standard pond ( 10,000 m2 pond, 2 m deep), with the assumption that the small field is cropped at 100%. Calculations are carried out with the linkage program shell  PE4VO1. pl  which incorporates the standard scenarios developed by EFED. Additional information on these models can be found at: http:// www. epa. gov/ oppefed1/ models/ water/ index. htm and in Table 10.

The crops for which triadimefon is registered include apples, pears, raspberries, turf ( commercial and residential), Christmas trees, and ornamentals. To simulate these uses, representative scenarios from several geographical regions ( when available) were run using the maximum labeled use rates, maximum number of applications per season ( where specified), and minimum application interval. These parameters were chosen in order to be representative of the legal labeled allowable maximum use. The crop scenarios used and the associated monitoring stations and meteorological files are summarized in Table 10.

Table 10. Summary of Crop Scenarios Used in Estimating EECs Triadimefon Uses ( EPA Reg. #) Crop Scenario MLRA/ Met Station Scenario Characterization Apple ( 264 737 & 432 1294) OR apple: Marion County, Cornelius silt loam MLRA A2; W24229 Selected based on geographical location, agricultural practices, and use patterns.

PA apple: Lancaster County, Elioak silt loam MLRA 148; W14737 NC apple: Henderson County, Hayesville loam MLRA 130; W03812 Grapes ( 264 737 & 432 1294) CA grape: San Joaquin County, San Joaquin loam MLRA 17; W23155, W23232 Selected based on geographical location, agricultural practices, and use patterns.

NY grape: Chautauqua County; Lordstown Channery silt loam MLRA 100/ 140; W14860 Pears ( 264 737 & 432 1294) CA fruit: Central Valley, Exeter fine sandy loam MLRA 17; W93193 CA fruit scenario represents all non citrus fruit grown in Central Valley CA. Selected based on label information.

Raspberries ( 264 737 & 432 1294) OR berries: Marion County, Woodburn silt loam MLRA A2; W24232 OR berry scenario represents blackberries, which is representative of caneberries ( including raspberries) Triadimefon Uses ( EPA Reg. #) Crop Scenario MLRA/ Met Station Scenario Characterization Page 35 of 241 Christmas Trees ( 264 737) OR Christmas Tree: Benton County; Pilchuck fine sand MLRA A2; W24232 Selected based on geographical location, agricultural practices, and use patterns.

Turf ( 829 289, 432 1293, 432 1360, 432 1367, 28293 278) FL Turf: Osceola County; Adamsville sand MLRA 156A; W12834 These turf scenarios are considered to be essentially generic, with no distinction made between sod farms, golf course fairways, greens and tees, or residential lawns. PA Turf: York County; Glenville silt loam MLRA 418; W14737 a. PRZM EXAMS Input Parameters Runoff and erosion output values as modeled by PRZM EXAMS take into account only that which is in the top 2 cm of soil. In reality, what is on the surface is paramount, with influence decreasing rapidly within the top 2 cm. Since the primary degradation product of concern, triadimenol, is formed mostly in the shallow subsurface, it is assumed that most of what becomes available for runoff/ erosion would be the parent compound triadimefon. However, some triadimenol is formed at or very near the surface, and some may even be formed on or within the vegetation. Since the dominant degradate formed will be triadimenol ( which is the principle degradate of concern), and this degradate is both more persistent and potentially more mobile than the parent, it must be considered along with the parent triadimefon. Therefore, it is necessary to model ` total' residues ( parent + degradate), since some portion of the total potential runoff should be assumed to be degradate. This was accomplished by calculating the half life of total residues, based on a 364 day soil study ( MRID # 42224104). Triadimefon degraded to triadimenol fairly quickly ( half life = 5.6 days), but triadimenol degraded much more slowly. Triadimenol continued to form for at least the first 60 days, reaching a peak of 76.8% of total applied parent. The half life for combined residues was determined by summing the percentage of total residues of concern ( traidimenol + tridimefon) over the course of the study, plotting this over time, and calculating the half life of the summed residues from a 2 parameter exponential decay curve fitted to the data ( r2 = 0.99). This value ( half life of total residues of concern), used in the PRZM/ EXAMS modeling, was determined to be 240 days.

For the PRZM/ EXAMS model, some initial assumptions/ simplifications were made: 1) Treated total residues ( parent triadimefon plus the degradate triadimenol) as a single component, in terms of fate properties ( half lives, etc.). Most of the parent converts to the degradate of concern, triadimenol, which is generally more persistent in the environment and thus cannot be ignored. 2) Assigned an application depth for the total residues of 0 cm to reflect surface applications. 3) Set the input parameters that are most relevant to processes that occur at or near time of application ( molecular weight, vapor pressure, solubility, K oc , and photolysis) to reflect the characteristics of the parent alone, because that is what is applied to the field. These values are very close to those for triadimenol; there is little or no impact on the overall risk assessment if the Page 36 of 241 input values for the degradate are used instead. Other inputs that are relevant to transport, fate, and persistence of compound ( soil and water half lives) are derived from characteristics of total residues ( parent + triadimenol, as determined from MRID # 42224104 & 42401201) since the degradate starts to form soon after application. 4) The aerobic soil half life for total residues ( triadimefon + triadimenol) was determined to be 240 days ( MRID # 42224104), calculated by combining radioactivity of both compounds for the duration of the study ( 364 days) and applying a 2 parameter exponential decay function ( r2 = 0.99, p < 0.0001). The aerobic aquatic half life for total residues of concern is then 480 days ( MRID # 42224104), which, in the absence of data, was derived by multiplying the aerobic soil value by a factor of 2.

Input Parameters. The following values were used as inputs for the Tier 2 model PRZM EXAMS with the Pond scenario. The values were chosen in accordance with the Input Parameter Guidance, and are intended to represent the combined residues of parent triadimefon and the degradate triadimenol ( Tables 11 and 12). Resulting aquatic EEC values are presented in Table 13.

Table 11. PRZM EXAMS Input Parameters  Fate Properties Input Parameter Value Reference/ Comment Molecular Weight 293.7 g/ mol Henry's Law Constant 1.15 x 10 7 atm m3/ mol CAS # 43121433 Vapor Pressure 7.6 x 10 7 mm Hg CAS # 43121433 Solubility 70 mg/ L RED # D275423 Koc 387 MRID # 41616008 Chemical Application Method 1 Indicates soil applied, uniform depth, user defined incorporation depth Incorporation Depth 0 cm spray application ( or broadcast granular)

Application efficiency 0.95 0.99 0.99 Indicates aerial spray application Indicates ground spray application Indicates granular broadcast application Spray Drift Fraction 0.05 0.01 0 Aerial spray application only Ground spray application only Granular broadcast application only Hydrolysis stable MRID # 41922101 Aqueous Photolysis Half life 0.32 days MRID # 42112901 & 41933601 Water Half life 480 days In absence of data, 2X aerobic soil metabolism half life of 240 days  MRID 42224104 Benthic Half life 217 days MRID # 41686101 Page 37 of 241 Soil Half life 240 days MRID 42224104  sum of parent + triadimenol, r2 = 0.99, p < 0.0001 FILTRA, UPTKF, PLVKRT, PLDKRT 0 Default values FEXTRC 0.5 Default value Table 12. PRZM EXAMS Scenario Specific Input Parameters Scenario Application Rate ( kg ai/ ha) # of applications Application interval Application date( s)

OR apple PA apple NC apple 0.2801 3 7 days April 1, April 8, April 15 CA grape NY grape 0.21 3 14 days May 1, May 15, May 29 CA fruit 0.2801 3 7 days April 1, April 8, April 15 OR berry 0.14 7 28 days May 1; 28 day intervals OR Xmas tree 0.2801 8 14 days May 1; 14 day intervals FL Turf ( spray)  golf max FL Turf ( spray)  golf max* PA Turf ( spray)  golf max FL Turf ( spray)  golf ave FL Turf ( spray)  golf ave* PA Turf ( spray)  golf ave FL Turf ( spray)  lawn PA Turf ( spray)  lawn FL Turf ( granular) PA Turf ( granular) 3.03 3.03 3.03 1.52 1.52 1.52 1.52 1.52 1.47 1.47 26 6 13 26 6 13 2 2 2 2 14 days 60 days 14 days 14 days 60 days 14 days 30 days 30 days 30 days 30 days Jan 1; 14 day intervals Jan 1; 60 day intervals Apr 1; 14 day intervals Jan 1; 14 day intervals Jan 1; 60 day intervals Apr 1; 14 day intervals May 1, June 1 May 1, June 1 May 1, June 1 May 1, June 1 * 6 application, 60d interval scenario modeled for comparative purposes only Table 13. Surface water EECs for triadimefon Scenario ( application) Application Method Peak concentration ( ppb) 21 day concentration ( ppb) 60 day concentration ( ppb)

NC Apple ( 0.25 lb ai/ A, 3 apps, 7d interval) ground spray 3.3 2.9 2.3 aerial spray 4.3 3.6 3.1 OR Apple ( 0.25 lb ai/ A, 3 apps, 7d interval) ground spray 1.6 1.3 1.0 aerial spray 3.0 2.6 2.0 PA Apple ( 0.25 lb ai/ A, 3 apps, 7d interval) ground spray 4.4 3.7 3.2 aerial spray 5.5 4.7 4.0 Scenario ( application) Application Method Peak concentration ( ppb) 21 day concentration ( ppb) 60 day concentration ( ppb)

Page 38 of 241 CA Grape ( 0.1875, 3 apps, 14d interval) ground spray 1.0 0.7 0.5 aerial spray 1.3 1.1 0.9 NY Grape ( 0.1875, 3 apps, 14d interval) ground spray 2.6 2.4 2.0 aerial spray 3.5 3.1 2.7 CA fruit ( represents pears) ( 0.25 lb ai/ A, 3 apps, 7d interval) ground spray 0.5 0.5 0.3 aerial spray 2.0 1.7 1.3 OR berries  ground spray ( 0.125 lb ai/ A, 7 apps, 28d interval) ground spray 1.7 1.5 1.3 OR Xmas Tree ( 0.25 lb ai/ A, 8 apps, 14d interval) ground spray 2.6 2.2 1.8 aerial spray 4.1 3.5 3.2 FL turf ( golf course application  max) ( 2.7 lb ai/ A, 26 apps, 14d interval) ground spray ( no incorporation) 150.6 127.5 108.3 FL turf ( golf course application  max)* ( 2.7 lb ai/ A, 6 apps, 60d interval) ground spray ( no incorporation) 54.4 45.5 34.2 FL turf ( golf course application  ave) ( 1.36 lb ai/ A, 26 apps, 14d interval) ground spray ( no incorporation) 75.6 64.2 54.3 FL turf ( golf course application  ave)* ( 1.36 lb ai/ A, 6 apps, 60d interval) ground spray ( no incorporation) 27.3 22.8 17.1 FL turf ( lawn & landscape) ( 1.36 lb ai/ A, 2 apps, 30d interval) ground spray ( no incorporation) 16.2 13.3 9.9 FL turf  granules ( consumer use) ( 1.31 lb ai/ A, 2 apps, 30d interval) broadcast 14.9 12.2 9.1 PA turf ( golf course application  max) ( 2.7 lb ai/ A, 13 apps, 14d interval) ground spray ( no incorporation) 110.3 93.2 74.1 PA turf ( golf course application  ave) ( 1.36 lb ai/ A, 13 apps, 14d interval) ground spray ( no incorporation) 55.2 46.8 37.2 PA turf ( lawn & landscape) ( 1.36 lb ai/ A, 2 apps, 30d interval) ground spray ( no incorporation) 11.0 9.1 6.9 PA turf  granules ( consumer use) ( 1.31 lb ai/ A, 2 apps, 30d interval) broadcast ( no incorporation) 9.8 8.1 6.1 * 6 application, 60d interval scenario modeled for comparative purposes only 3. Terrestrial Organism Exposure Modeling Terrestrial wildlife exposure estimates are typically calculated for birds and mammals, emphasizing a dietary exposure route for uptake of the pesticide. These exposures are considered surrogates for terrestrial phase amphibians as well as reptiles. Pesticide residues on food items are estimated based on the assumption that terrestrial organisms are exposed to a single pesticide residue in a given exposure scenario. Application methods for liquid triadimefon formulations include ground spray, aerial spray, and chemigation. Additionally, granular triadimefon is broadcast on residential lawns and turf ( no soil incorporation). Page 39 of 241 Exposure of free ranging receptors is a function of the timing and extent of pesticide application with respect to the location and behavior of identified receptors. EFED's terrestrial exposure model generates exposure estimates assuming that the receptor is present on the use site at the time that pesticide levels are their highest. The maximum pesticide residue concentration on food items is calculated from both initial applications and any additional applications taking into account pesticide degradation between applications. Although this is a conservative approach, it is not outside the realm of possibility, particularly when evaluating acute risks. Longer term exposure estimates used in generating chronic risk estimates also assume that a receptor is present when pesticide residue levels are highest, and furthermore assume the receptor uses the site to forage on a repeated basis although the exact frequency and duration of foraging events on the use site is not specified.

The duration of the exposure for estimates of acute risks is a single day and occurs when pesticide residues on food items are highest. The acute exposure level is the quantity of residues consumed in a single day associated with food requirements for that day.

The current approach to screening level terrestrial exposure estimation does not directly relate the timing of exposure to critical or sensitive population, community, or ecosystem processes. Given that for triadimefon, application timing and location are crop dependent, it is difficult to address the temporal and spatial co occurrence of triadimefon use and sensitive ecological processes. However, it is worth noting that pesticides are frequently used on agricultural crops from spring through fall, which are times of active migrating, feeding, and reproduction for many wildlife species. Triadimefon use of turf may encompass the entire year, thereby allowing for potential year round exposure to organisms. The increased energy demands associated with these activities ( as opposed to hibernation, for example) can increase the potential for exposure to pesticide contaminated food items since agricultural areas can represent a concentrated source of relatively easily obtained, high energy food items. In this assessment, the spatial extent of exposure for terrestrial animal species is limited to the use area only. The majority of applied triadimefon will likely be limited to the use area although some spray drift is possible, particularly for aerial spray applications.

Currently, the Agency does not require toxicity studies on reptiles and amphibians in support of pesticide registrations. To accommodate this data gap, birds are used as surrogates for terrestrialphase amphibians and reptiles. It is assumed that given the typically lower metabolic demands of reptiles and amphibians compared to birds, exposure to birds would be greater due to higher relative food consumption. While this assumption is likely true, there are no supported relationships regarding the relative toxicity of a compound to birds and herpetofauna. The lack of toxicity data on reptiles and amphibians represents an important source of uncertainty in this assessment.

a. Spray Applications and Residues Estimated exposure concentrations for terrestrial receptors were determined using the standard screening level exposure model, TREX ( v. 1.2) ( US EPA, 2005). Maximum exposure levels were calculated for spray applications of triadimefon using maximum proposed application rates, Page 40 of 241 maximum number of applications, and minimum application intervals for all proposed uses ( Table 14). Additionally, average golf course use rates and application intervals were used, based on information provided in the Use Closure Memo. These exposure estimates are based on a database of pesticide residues on wildlife food sources associated with a specified application rate. Essentially, for a single application, there is a linear relationship between the amount of pesticide applied and the amount of pesticide residue present on a given food item. These relationships for the various food items are determined from the Kenaga nomogram as modified by Fletcher ( Hoerger and Kenaga, 1972; Fletcher et al., 1994). TREX ( v. 1.2) is a simulation model that, in addition to incorporating the nomogram relationship, also includes pesticide degradation in the estimation of EECs.

TREX calculates pesticide residues on each type of food item on a daily interval for one year. A first order decay function is used to calculate the residue concentration at each day based on the concentrations present from both the initial and additional applications. The first order rate equation is:

C t = C i e kt Where C t is concentration at time t ( days; t= 0 initially), C i is initial concentration after application, k is the foliar dissipation half life, and t is time in days. The initial concentration, C i , is determined by multiplying the application rate by a constant specific to a food item. For 1.0 lb a. i. of pesticide per acre the upper bound, food item concentration ( ppm) is: 240 for short grass, 110 for tall grass, 135 for broadleaf plants and small insects, and 15 for fruits, pods, and large insects. In many cases, an empirically determined foliar dissipation half life value is not available, in which case the default value of 35 days is used ( Willis and McDowell, 1987). The food item concentration on any given day is the sum of all concentrations up to that day taking into account the first order degradation. The initial application is on day 0 ( t = 0) and runs for 365 days. Over the 365 day run, the highest residue concentration is used in calculations of the RQ.

The EECs on food items may be compared directly with dietary toxicity data or converted to an oral dose, as is the case for small mammals. This triadimefon screening level risk assessment uses upper bound predicted residues as the measure of exposure. The predicted upper bound and mean residues of triadimefon that may be expected to occur on selected avian or mammalian food items immediately following application of the liquid formulation on apples, raspberries, grapes, golf course turf, residential/ commercial and recreational turf, and Christmas trees are presented in Table 14. For mammals, the residue concentration is converted to daily oral dose based on the fraction of body weight consumed daily as estimated through mammalian allometric relationships.

Importantly, TREX considers exposure only in the area where triadimefon is applied. The underlying assumption is that most, if not all, of the applied pesticide will settle in the use area. However, depending on weather conditions and type of application, spray drift of pesticides may occur, increasing the likelihood of wildlife exposure outside the use area. Since triadimefon is applied via spray methods, spray drift in some cases is likely. Page 41 of 241 Page 42 of 241 Table 14. Triadimefon EECs on avian and mammalian food items following application Use Food items Max EEC ( ppm) Mean EEC ( ppm)

Apples ( 0.25 lb ai/ A, 3 applications, 7d interval) Short grass 157.7 55.9 Tall grass 72.3 23.7 Broadleaf plants/ small insects 88.7 29.6 Fruits, pods, seeds, large insects 9.9 4.6 Raspberries ( 0.125 lb ai/ A, 7 applications, 28d interval) Short grass 69.0 24.5 Tall grass 31.6 10.4 Broadleaf plants/ small insects 38.8 12.9 Fruits, pods, seeds, large insects 4.3 2.0 Grapes ( 0.1875 lb ai/ A, 3 applications, 14d interval) Short grass 104.9 37.2 Tall grass 48.1 15.7 Broadleaf plants/ small insects 59.0 19.7 Fruits, pods, seeds, large insects 6.6 3.1 Golf Course Turf  maximum rate ( 2.7 lb ai/ A, 26 applications, 14d interval) Short grass 2703.9 957.6 Tall grass 1239.3 405.6 Broadleaf plants/ small insects 1520.9 507.0 Fruits, pods, seeds, large insects 169.0 78.9 Golf Course Turf  average rate ( 1.36 lb ai/ A, 26 applications, 14d interval) Short grass 1347.0 477.1 Tall grass 617.4 202.1 Broadleaf plants/ small insects 757.7 252.6 Fruits, pods, seeds, large insects 84.2 39.3 Residential/ Commercial/& Recreational Turf ( 1.36 lb ai/ A, 2 applications, 14d interval) Short grass 573.8 203.2 Tall grass 263.0 86.1 Broadleaf plants/ small insects 322.7 107.6 Fruits, pods, seeds, large insects 35.9 16.7 Christmas Trees ( 0.25 lb ai/ A, 8 applications, 14 day interval) Short grass 220.8 78.2 Tall grass 101.2 33.1 Broadleaf plants/ small insects 124.2 41.4 Fruits, pods, seeds, large insects 13.8 6.4 b. Granular Applications Triadimefon is applied in granular form to residential turf and is not incorporated into the soil. Birds and mammals in the field may be exposed to triadimefon by ingesting dietary material ( e. g., granules, plants, earthworms). They also may be exposed via other routes, such as incidental soil ingestion, dermal contact, preening activities, and ingestion of drinking water. Although the Page 43 of 241 habitat of a bird or mammal is not limited to a square foot, there is presumably a direct correlation between the concentration of a pesticide in the environment ( mg/ ft2) and the chance that an animal will be exposed to a concentration that could adversely affects its survival. Further description of the mg/ ft2 index is provided in US EPA, 2004a and US EPA, 1992.

Terrestrial EECs were calculated based on an estimation of loading of pesticide per unit area. The labeled application rate for the active ingredient is the basis for exposure, and the broadcast application method of granular triadimefon to turf assumes that 100% of the granules are unincorporated.

Table 15. EECs for granular triadimefon application to residential lawns/ turf Application rate EEC ( mg ai/ ft2)

1.31 lb ai/ A 2 applications, 30d interval 14 4. Non Target Plant Exposure Modeling Terrestrial plant exposure characterization employs runoff and spray drift scenarios contained in OPP's Terrplant model. Exposure calculations are based on a pesticide's water solubility and the amount of pesticide present in the surface soil within the first inch of depth. For dry areas, the loading of pesticide active ingredient from runoff to adjacent non target area is assumed to occur from one acre of treatment to one acre of non target area. For terrestrial plants inhabiting semiaquatic ( wetland) areas, runoff is considered to occur from a larger source area with active ingredient loading originating from 10 acres of treated area to a single acre of non target wetland. Default spray drift assumptions are 1% for ground applications and 5% for aerial, airblast, forced air, and chemigation applications. Terrestrial plant EECs for non granular and granular formulations are summarized in Table 16. Predicted EECs resulting from spray drift and aerial applications are derived for non granular application only.

Table 16. Terrestrial Plant EECs for spray and granular triadimefon applications Crop/ scenario Application Adjacent Area Runoff Wetland Area Runoff Spray Drift EEC ( lb ai/ A) EEC ( lb ai/ A) EEC ( lb ai/ A)

Apples & Pears ( 0.25 lb ai/ A) Ground Unincorp. 0.008 0.053 0.003 Aerial, Airblast, Spray Chemigation 0.016 0.043 0.013 Raspberries ( 0.125 lb ai/ A) Ground Unincorp. 0.004 0.026 0.001 Grapes ( 0.1875 lb ai/ A) Ground Unincorp. 0.006 0.039 0.002 Aerial, Airblast, Spray Chemigation 0.012 0.032 0.009 Golf Course Turf ( 2.7 lb ai/ A) Ground Unincorp. 0.081 0.567 0.027 Page 44 of 241 Residential/ Commercial& Recreational Turf ( 1.36 lb ai/ A) Ground Unincorp. 0.041 0.286 0.014 Christmas Trees ( 0.25 lb ai/ A) Ground Unincorp. 0.008 0.053 0.003 Aerial, Airblast, Spray Chemigation 0.016 0.043 0.013 GRANULAR Residential/ Commercial & Recreational Turf ( 1.31 lb ai/ A) Unincorporated 0.026 0.262 N/ A C. Ecological Effects Characterization In screening level ecological risk assessments, effects characterization describes the types of effects a pesticide can produce in an organism or plant. This characterization is based on registrant submitted studies that describe acute and chronic toxicity information for various aquatic and terrestrial animals and plants. Toxicity data are available for parent triadimefon as well as the major metabolite, triadimenol. In addition, other sources of information, including reviews of the open literature and the Ecological Incident Information System ( EIIS), are conducted to further refine the characterization of potential ecological effects.

Appendix C presents the results of the registrant submitted toxicity studies. Studies obtained through the ECOTOX database are described in Appendices F, G, and H. In addition to the data submitted in support of registration and the information compiled through the Agency pesticide review process, the ECOTOX ( ECOTOXicity) database was used to identify additional data from the open literature.

Following implementation of the Overview document ( USEPA, 2004a), EFED began developing guidelines for incorporation of open literature into ecological risk assessments ( USEPA, 2004b). Toxicity data from open literature are identified via the ECOTOX search engine maintained by EPA/ ORD. Open literature data presented in this draft of the risk assessment were obtained from the data provided to EFED by ORD on July 4, 2005 . In order to be included in the ECOTOX database, papers must meet the following minimum criteria:

( 1) the toxic effects are related to a single chemical exposure ( 2) the toxic effects are on an aquatic or terrestrial plant or animal species ( 3) there is a biological effect on live, whole organisms ( 4) a concurrent environmental chemical concentration/ dose or application rate is reported ( 5) there is an explicit duration of exposure Data that passes the ECOTOX screen are evaluated along with the registrant submitted data, and may be incorporated qualitatively or quantitatively into the risk assessment. In general, effects data in the open literature that are less than or more conservative than the registrant submitted data are considered. The degree to which open literature data is quantitatively or qualitatively Page 45 of 241 characterized is dependent on whether the information is relevant to the assessment endpoints ( i. e., maintenance of survival, reproduction, and growth) identified in the problem formulation. For example, endpoints such as behavior modifications cause a reduction in species survival, reproduction, and/ or growth. Specific open literature that are considered include the following:

( 1) the endpoint is more sensitive than those identified in the registrant data ( 2) the data is for under represented taxa ( i. e., amphibians) ( 3) the data includes endpoints not normally evaluated in registrant studies, but is ecologically relevant For detailed information regarding studies obtained through ECOTOX, see Appendices F, G, and H. Based on the reviewed registrant submitted studies, triadimefon and triadimenol are practically non toxic to slightly toxic to birds and mammals and slightly to moderately toxic to freshwater fish and invertebrates on an acute basis. Tables 17 and 18 summarize the most sensitive ecological toxicity endpoints for aquatic and terrestrial species, respectively. These toxicity endpoints are based on an evaluation of both the submitted studies and the open literature, as previously discussed. Discussions of the effects of triadimefon and triadimenol on aquatic and terrestrial taxonomic groups are presented below. Submitted studies are also addressed for each taxonomic group.

Table 17. Aquatic Toxicity profile for Triadimefon and Triadimenol Endpoint Chemical Environment/ Species Toxicity Value Used in Risk Assessment Reference Comments Acute Toxicity to Fish Triadimefon Freshwater Rainbow trout ( TGAI)

Est/ Marine No data ( TGAI) 96 hr LC50 = 4.1 ppm No Data MRID 43256201 NA Acceptable No studies were submitted or located in the open literature Triadimenol Freshwater Rainbow trout Bluegill sunfish ( TGAI)

Est/ Marine No data ( TGAI) 96 hr LC50 = 14 ppm No Data MRID 071469 NA Acceptable No studies were submitted Chronic Toxicity to Fish Triadimefon Freshwater Rainbow trout ( TGAI)

Est/ Marine No data ( TGAI) NOAEC = 0.041 ppm LOAEC = 0.116 ppm No Data MRID 251243 NA Supplemental: insufficient reporting of replicate results; 20% reduction in growth at 0.116 ppm.

No studies were submitted or located in the open literature Endpoint Chemical Environment/ Species Toxicity Value Used in Risk Assessment Reference Comments Page 46 of 241 Triadimenol Freshwater No data ( TGAI)

Est/ Marine No data ( TGAI) No Data No Data NA NA No studies were submitted No studies were submitted Acute Toxicity to Invertebrates Triadimefon Freshwater Daphnia magna ( TGAI)

Est/ Marine No data ( TGAI) 48 hr LC50 = 1.6 ppm No Data MRID 231311 NA Acceptable No studies were submitted or located in the open literature Triadimenol Freshwater Daphnia magna ( TGAI)

Est/ Marine No data ( TGAI) 48 hr LC50 = 2.5 ppm No Data MRID 071469 NA Acceptable No studies were submitted Chronic Toxicity to Invertebrates Triadimefon Freshwater Daphnia magna ( TGAI)

Est/ Marine No data ( TGAI) NOAEC = 0.052 ppm LOAEC = 0.119 ppm No Data MRID 41922101 NA Supplemental: individual animal lenths not included; reduction in adult length No studies were submitted or located in the open literature Triadimenol Freshwater No data ( TGAI)

Est/ Marine No data ( TGAI) No Data No Data NA NA No studies were submitted No studies were submitted Toxicity to Aquatic Plants Triadimefon Vascular No data ( TGAI)

Non vascular Green algae S. subspicatus ( TGAI) No Data EC50 = 1.71 ppm NOAEC = 0.1 ppm NA MRID 00159558 No studies were submitted or located in the open literature Supplemental: not guideline test species Endpoint Chemical Environment/ Species Toxicity Value Used in Risk Assessment Reference Comments Page 47 of 241 Triadimenol Vascular No data ( TGAI)

Non vascular Green algae S. subspicatus ( TGAI) No Data EC50 = 3.7 ppm NOAEC = 0.32 ppm NA MRID 00159558 No studies were submitted Supplemental: not guideline test species Table 18. Terrestrial Toxicity Profile for Triadimefon and Triadimenol Endpoint Chemical Environment/ Species Toxicity Value Used in Risk Assessment Reference Comments Acute Toxicity to Birds Triadimefon Bobwhite quail LD50 = > 2000 mg ai/ kg bw MRID 41895901 Acceptable: no mortalities or signs of toxicity at any test concentration Triadimenol Bobwhite quail LD50 = > 2000 mg ai/ kg bw MRID 071469 Acceptable: no mortalities or signs of toxicity at any test concentration Subacute Toxicity to Birds Triadimefon Bobwhite quail LC50 = 8392 ppm MRID 00050066 Acceptable: reduced body weight gain, reduced food consumption Triadimenol Mallard duck LC50 > 5000 ppm MRID 00126277 Acceptable: no mortalities or signs of toxicity at any test concentration Reproductive Toxicity to Birds Triadimefon Bobwhite quail NOAEC = 20 ppm LOAEC = 100 ppm MRID 110431 Acceptable: Increase in eggs cracked, reduction in fertile eggs, viable embryos, hatchlings, and 14 day survival Triadimenol Mallard duck NOAEC = 100 ppm LOAEC = 500 ppm MRID 40283102 Acceptable: Reduction in eggs laid, viability, hatchability, and 14 day survivors Acute Toxicity to Mammals Triadimefon Rat LD50 = 1090 mg/ kg ( females) MRID 00264276 Acceptable Triadimenol Rat LD50 = 689 mg/ kg ( males) MRID 00125411 Acceptable Chronic Toxicity to Mammals Triadimefon Rat NOAEC = 50 ppm LOAEC = 1800 ppm MRID 00155075 92188019 92188320 Decreased pup weights and viability Triadimenol Rat NOAEC = 100 ppm LOAEC = 500 ppm MRID 00151248 Decreased pup weights Page 48 of 241 Acute toxicity to honey bees Triadimefon Honey bee LD50 = > 25 µ g ai/ bee MRID 42307804 Acceptable Triadimenol No data No data NA No studies were submitted Toxicity to Terrestrial Plants Triadimefon No data No data NA Not required; No studies were submitted or located in the open literature that could be used quantitatively, Triadimenol 1. Aquatic Effects Characterization a. Toxicity to Freshwater Animals i. Acute Toxicity to Freshwater Fish Two freshwater fish toxicity studies using the TGAI are required to establish the toxicity of triadimefon. The preferred test species are rainbow trout ( Oncorhynchus mykiss  a coldwater fish) and bluegill sunfish ( Lepomis macrochirus  a warmwater fish). Toxicity data are available for technical grade triadimefon as well as the formulated product 50WP, a 50% formulation. Complete toxicity results are available in Appendix C. Freshwater fish acute toxicity values ( LC 50 ) for triadimefon range from 4.1  28 ppm ( rainbow trout) and 10  24.7 ppm ( bluegill sunfish), indicating that triadimefon is slightly to moderately toxic to freshwater fish on an acute basis. The most sensitive species tested is the rainbow trout, with an LC 50 of 4.1 ppm, which is categorized as moderately toxic ( MRID 43256201). Toxicity data for an additional freshwater fish species, the channel catfish ( Ictalurus punctatus) were also provided, with an LC 50 value of 15 ppm ( MRID 231311).

As with triadimefon, two freshwater fish toxicity studies are required to establish the toxicity of the major triadimefon degradate, triadimenol. Toxicity data are available for rainbow trout, bluegill sunfish, goldfish ( Carasium auratus) and golden orfe ( Leuciscus idus melanotus). Complete toxicity results are available in Appendix C. Freshwater fish acute toxicity values ( LC 50 ) for triadimenol range from 14  50 ppm, indicating that triadimenol is slightly toxic on an acute basis. The most sensitive species tested were the rainbow trout and bluegill sunfish, with an LC 50 of 14 ppm, which is characterized as slightly toxic ( MRID 071469). The goldfish study ( MRID 071469) indicated that the triadimenol LC 50 was between 10 and 50 ppm, but the actual LC 50 could not be calculated because there were too few organisms per test level and the test levels were too far apart.

No further acute freshwater fish studies were obtained through the ECOTOX literature database.

ii. Chronic Toxicity to Freshwater Fish A freshwater fish early life stage test using the TGAI is required for triadimefon because the enduse product is expected to be transported to water from the intended use sites. Given its intended use, triadimefon's presence in water is likely to be continuous or recurrent, and it has a long halflife in the aquatic environment ( 668 days for aerobic aquatic metabolism). Toxicity data are available for the fathead minnow ( Pimephales promelas) and rainbow trout. The most sensitive Page 49 of 241 species is the rainbow trout, with a NOAEL of 41 ppb based on reduction of larval growth ( MRID 251243). The fathead minnow study demonstrated a NOAEL of 170 ppb based on adult survival ( MRID 41922103).

There are currently no chronic fish toxicity studies submitted or in the open literature ( ECOTOX) for the degradate triadimenol, and no further chronic freshwater fish studies were obtained through ECOTOX for either chemical.

iii. Acute Toxicity to Freshwater Invertebrates A freshwater aquatic invertebrate toxicity test using the TGAI is required to establish the toxicity of triadimefon to aquatic invertebrates. Acute freshwater invertebrate data are available for both the TGAI as well as the formulated product 50WP, a 50% formulation. Complete toxicity results are available in Appendix C. Freshwater invertebrate 48 hour acute toxicity values ( LC 50 ) for triadimefon range from 1.6  11.3 ppm for Daphnia magna, indicating that triadimefon is slightly to moderately toxic to freshwater invertebrates on an acute basis. The most sensitive study indicated an LC 50 of 1.6 ppm ( MRID 231311). Toxicity data for an additional species, the crayfish ( Orconectes neglectus) indicated that triadimefon is practically non toxic to this species ( LC 50 = 104 ppm; MRID 254693).

Freshwater invertebrate toxicity tests were also performed for the degradate triadimenol. The 48 hour Daphnia magna LC 50 for triadimenol is 2.5 ppm ( MRID 071469), classifying this degradate as moderately toxic to Daphnia.

No further acute freshwater invertebrate studies were obtained through the ECOTOX literature database.

iv. Chronic Toxicity to Freshwater Invertebrates A freshwater aquatic invertebrate life cycle test using the TGAI is required for triadimefon because the end use product is expected to be transported to water from the intended use sites Given its intended use, triadimefon's presence in water is likely to be continuous or recurrent, and it has a long half life in the aquatic environment (> 4 days; triadimefon t 1/ 2 = 668 days for aerobic aquatic metabolism). Toxicity data are available for Daphnia magna, with NOAEL values of 0.087 ppm ( decreased reproduction; MRID 246736) and 0.052 ppm ( decreased adult length; MRID 41922102).

No chronic freshwater invertebrate toxicity data area available for the degradate triadimenol.

No further chronic freshwater invertebrate studies were obtained through the ECOTOX literature database.

b. Toxicity to Estuarine/ Marine Animals No triadimefon or triadimenol estuarine/ marine animal ( fish and invertebrate) acute or chronic toxicity tests were submitted to the Agency. However, acute tests are required because the enduse product is expected to reach this environment based on its widespread use patterns ( e. g. turf). Page 50 of 241 Estuarine/ marine animal chronic toxicity tests are also required for triadimefon because the enduse produce is expected to be transported to the estuarine/ marine environment from the intended use sites and the following conditions are met: ( 1) the pesticide is intended for use such that its presence in the water is likely to be continuous or recurrent regardless of toxicity, and ( 2) the pesticide is persistent in water ( t 1/ 2 > 4 days). Triadimefon has an aerobic aquatic half life of 668 days.

The lack of any estuarine/ marine animal toxicity data represents a data gap, although the relatively low toxicity of triadimefon and triadimenol to freshwater animals suggests that submission of new studies with estuarine/ marine animal species may not be crucial to this assessment. No estuarine/ marine toxicity studies were obtained through the ECOTOX database.

c. Toxicity to Aquatic Plants Currently, aquatic plant testing is not required for pesticides other than herbicides or chemicals applied directly to the aquatic environment, or on a case by case basis ( e. g., phytotoxicity problems concerning the product arise and open literature data are not available to address the problems). Aquatic plant toxicity studies were performed for triadimefon on both TGAI and the 50WP formulated product ( 50% formulation) on green algae ( Selenastrum capricornutum). EC 50 values ranged from 0.91 to 1.71 ppm ( MRIDs 43401707, 41616007, & 00159558). The EC 50 for triadimenol ( TGAI) was 3.7 ppm ( MRID 266051). No studies were performed on vascular aquatic plant species. No aquatic plant toxicity data area available for the degradate triadimenol. Additionally, no further aquatic plant studies were obtained through ECOTOX for triadimefon or triadimenol.

2. Terrestrial Effects Characterization a. Acute and Subacute Toxicity to Birds In order to establish the acute and subacute toxicity to birds, the following tests are required using triadimefon TGAI: one avian single dose oral ( LD 50 ) study on one species ( preferably mallard or bobwhite quail), and two subacute dietary studies ( LC 50 ) on one species of waterfowl ( preferably the mallard duck) and one species of upland game bird ( preferable bobwhite quail).

The acute oral toxicity of triadimefon ( TGAI) to 14 day old mallard ducks ( Anas platyrhynchos) was assessed over 8 days ( MRID 00050070). The 8 day acute oral LD 50 exceeded the highest dose tested (> 4000 mg ai/ kg bw). There were no mortalities in any treatment groups, and therefore triadimefon is classified as practically non toxic to mallard ducks. Triadimefon acute oral toxicity to adult bobwhite quail was assessed over 14 days ( MRID 41895901). The 14 day oral LD 50 exceeded the highest dose tested (> 2000 mg ai/ kg bw). No mortality occurred at any dose level throughout the study and no clinical signs of toxicity were observed, classifying triadimefon as practically non toxic to bobwhite quail. An additional study was performed on the non guideline species canary, which demonstrated no mortality of signs of toxicity at any dose level. The LD 50 value therefore exceeded the highest dose tested ( LD 50 = > 1000 mg ai/ kg bw; MRID 126274).

Two subacute dietary studies using triadimefon TGAI are required to establish toxicity to birds. Page 51 of 241 Toxicity tests performed on the bobwhite quail indicate that triadimefon is practically non toxic on a subacute dietary basis to this species. Dietary LC 50 values ranged from > 4640 ppm for bobwhite quail ( MRID 00050066) to > 10,000 ppm for the mallard duck ( Acc. # 231311, 1977). Only one dietary study ( MRID 0050066) indicated any mortalities, and the bobwhite quail LC 50 was calculated to be 8392 ppm for this study.

Avian single dose oral toxicity studies were also performed on the major degradate triadimenol. The acute oral ( LD 50 ) toxicity of triadimenol to bobwhite quail exceeded the highest dose tested (> 2000 mg ai/ kg) ( MRID 126276). Additionally, a triadimenol subacute dietary study was performed with mallard ducks, and no mortality or signs of toxicity were seen at any doses ( LC 50 > 5000 ppm; MRID 00126277).

No further acute avian studies were obtained through ECOTOX for triadimefon or triadimenol.

b. Chronic Toxicity to Birds Chronic avian testing is required because triadimefon is persistent and has multiple applications per growing season. Four avian reproduction studies, which are summarized in Appendix C, were submitted for review.

In the bobwhite quail study ( MRID 110431), the NOAEC was determined to be 20 ppm ai, based on an increase in cracked eggs and decreases in the number of fertile eggs, viable embryos, hatchlings, and 14 day old survivors. The primary effect of triadimefon on avian reproduction seems to be the number of fertile eggs and viable 14 day old survivors. Both of these endpoints demonstrated an 83% decrease at the highest dose of 500 ppm. The LOAEC was 100 ppm ai.

The other bobwhite quail study ( MRID 42342301) was classified as supplemental because of problems with the incubator causing cracked eggs in the control dose. A mallard duck study ( MRID 42342302) demonstrated a NOAEC at the highest tested concentration of 780 ppm ai. There were no effects of triadimefon exposure on mortality, behavior, or reproductive performance at this concentration. A second mallard duck study ( MRID 248117) was classified as supplemental because of poor reproductive success of the control ( poor hatchling survival rates in the controls).

Avian reproductive toxicity tests were also performed for the degradate triadimenol. The NOAEC for mallard duck ( MRID 149835) was determined to be 100 ppm ai, based on decreases in the number of eggs laid, viability, hatchability, and 14 day survivors. A study with the bobwhite quail was classified as invalid ( MRID 149834) because the observations in the study suggest that the controls may have been less capable of successful reproduction than the test organisms, thereby diminishing their value as a true control for all reproductive parameters.

No further chronic avian studies were obtained through ECOTOX for triadimefon or triadimenol.

c. Acute Toxicity to Mammals Wild mammal testing is required on a case by case basis, depending on the results of lower tier Page 52 of 241 laboratory mammalian studies, intended use patterns, and pertinent environmental fate characteristics. In most cases, rate or mouse toxicity values obtained from the Agency's Heath Effects Division ( HED) substitute for wild mammal testing. The acute mammalian toxicity studies cited in HED's one liners are summarized in Appendix C. Rats exposed to triadimefon ( TGAI) showed LD 50 values of 1470 mg/ kg ( males; 95% C. I.= 982  2192) and 1090 mg/ kg ( females; 95% C. I. = 753  1549) ( MRID 00264276), classifying triadimefon as slightly toxic to mammals on an acute basis.

Mammal acute toxicity tests were also performed on laboratory rats for the degradate triadimenol. Rats exposed to triadimenol ( TGAI) showed LD 50 values of 689 mg/ kg ( males; 95% C. I. = 571  831) and 752 mg/ kg ( females; 95% C. I. = 647  874) ( MRID 00125411), classifying triadimenol as slightly toxic to mammals on an acute basis.

For the purposes of this risk assessment, the acute toxicity value for triadimenol of 689 mg/ kg will be used to calculate risk quotients for both parent triadimefon and triadimenol.

One study obtained through the ECOTOX database was identified by the OPP/ EFED screen as a more sensitive toxicity endpoint ( Reference # 77575). This study was deemed supplemental but could not be used quantitatively because it cannot be linked directly to the effects endpoints used by the Agency. Only male rats were dosed with triadimefon, the study only lasted 15 days, and the endpoint ( increase in liver weight) cannot be quantitatively linked to fertility, fecundity, or survival.

d. Chronic Toxicity to Mammals Similar to the acute data, mammalian chronic data obtained from the Agency's HED are substituted for wild mammalian testing. HED reproductive and developmental toxicity values are reported in Appendix C. These studies provide adequate toxicity data on chronic developmental and reproductive effects of triadimefon. Chronic triadimefon studies using laboratory rats show decreased pup weights and viability in the F 1 and F 2 generations and decreased litter size in the F 2 generation ( MRID 00155075, 92188019, 92188320), with an offspring NOAEL of 50 ppm ai.

Chronic toxicity studies on the degradate triadimenol showed decreased pup weights with a NOAEL of 100 ppm ai and a LOAEL of 500 ppm ai ( MRID 00151248).

e. Acute Toxicity to Non target Insects ( Honeybee) A honey bee acute contact study using the TGAI is required for triadimefon because its use will result in honeybee exposure. The results of acute contact toxicity testing of triadimefon on the honeybee ( Apis mellifera) are summarized in Appendix C. No mortality was observed after 48 hours in the contact or oral tests at exposure up to 25 µ g/ ai bee. The LD 50 for both studies was determined to be > 25 µ g ai/ bee ( MRID 42307804 & 5001991), classifying triadimefon as practically non toxic to honeybees on an acute basis. No data are available for the degradate triadimenol, and no further studies were obtained from ECOTOX for either chemical.

f. Toxicity to Non target Plants Page 53 of 241 Currently, terrestrial plant testing is not required for pesticides other than herbicides except on a case by case basis. No terrestrial plant toxicity values were submitted for triadimefon. Although several studies were obtained through ECOTOX, none of the identified studies were suitable for use as quantitative toxicity endpoints in this risk assessment; however, several of the studies can be interpreted qualitatively to demonstrate potential terrestrial plant risk from triadimefon use. The following studies obtained from ECOTOX provide valuable information on the effects of triadimefon to terrestrial plant species:

° ECOTOX reference # 77555: The study demonstrated that Kentucky bluegrass regrowth ( measured as dry weight) following treatment with 0.2 lb ai/ A triadimefon was significantly inhibited 14 days after treatment. This same study showed a height decrease in kidney bean plants treated with 0.25 mg triadimefon per plant. Although the study did not provide adequate information to quantitatively calculate RQ values for non target terrestrial plants, these results suggest that triadimefon may have negative effects on both monocot and dicot non target terrestrial plants.

° ECOTOX reference # 76504: The study demonstrated a decrease in Easter lily plant height following soil drench ( 300  500 mg/ L ai) or bulb dip treatment ( 20  100 mg/ L ai).

° ECOTOX reference # 77554: The study showed a decrease in seed germination rate, root length, shoot length, and area of primary and secondary leaves in barley treated with a soil drench of 250 µ M triadimefon.

° ECOTOX reference # 72042: The study demonstrated a decrease in 4 12 week old clover fresh weight and nitrogen fixation exposed to 50 mg/ kg triadimefon.

° ECOTOX reference # 77683: The study showed a decrease in coleoptile length in barley exposed to 0.15 g/ kg seed triadimefon ( seed treatment).

Although none of the studies provided adequate information to quantitatively calculate RQ values for non target terrestrial plants, these results suggest that triadimefon may have negative effects on both monocot and dicot non target terrestrial plants.

The following ( Table 19) is a listing of the other terrestrial plant studies identified by ECOTOX and the reasons why they were deemed unsuitable for use ( either qualitatively or quantitatively) in this risk assessment:

Table 19. Rationale for Exclusion of Terrestrial Plant ECOTOX Studies ECOTOX Reference Number Species Rational for Exclusion 76505 Winter Wheat Study examined the effect of fungicidal properties on subsequent crop yield 77554 Barley Seed treatment Page 54 of 241 77556 Cucumber Inappropriate endpoint Measurement was tolerance to cold stress 77577 Spring Barley Study showed that application of triadimefon to barley controlled leaf disease without influencing yield 77591 Wheat Inappropriate endpoint Measurement was moisture stress tolerance 77669 Wheat Inappropriate endpoint Measurement was moisture stress tolerance 77672 Cowpea Triadimefon treatment lead to increased yield ( due to disease control)