77613 Kidney bean Inappropriate endpoint Measurement was cold and heat tolerance 77687 Mung bean Inappropriate endpoint Measurement was alleviation of UV stress by triadimefon 77572 Chickpea Triadimefon treatment increased reproductive efficiency as a result of disease control 3. Endocrine Effects EPA is required under the FFDCA, as amended by FQPA, to develop a screening program to determine whether certain substances ( including all pesticide active and other ingredients) " may have an effect in humans that is similar to an effect produced by a naturally occurring estrogen or other such endocrine effects as the Administrator may designate." Following the recommendations of its Endocrine Disruptor Screening and Testing Advisory Committee ( EDSTAC), EPA determined that there was scientific basis for including, as part of the program, the androgen and thyroid hormone systems, in addition to the estrogen hormone system. EPA also adopted EDSTAC's recommendation that the Program include evaluations of potential effects in wildlife. For pesticide chemicals, EPA will use FIFRA and, to the extent that effects in wildlife may help determine whether a substance may have an effect in humans, FFDCA has the authority to require wildlife evaluations. As the science develops and resources allow, screening of additional hormone systems may be added to the Endocrine Disruptor Screening Program ( EDSP). When the appropriate screening and/ or testing protocols being considered under the Agency's EDSP have been developed, triadimefon, triadimenol, and their degradates may be subjected to additional screening and/ or testing to better characterize effects related to endocrine disruption. Page 55 of 241 IV. RISK CHARACTERIZATION Risk characterization is the integration of exposure and effects characterization to determine the ecological risk from the use of triadimefon and the likelihood of effects on aquatic life, wildlife, and plants based on varying pesticide use scenarios. The risk characterization provides an estimation and a description of the risk; articulates risk assessment assumptions, limitations, and uncertainties; synthesizes an overall conclusion; and provides the risk managers with information to make regulatory decisions.

A. Risk Estimation  Integration of Exposure and Effects Data Results of the exposure and toxicity effects data are used to evaluate the likelihood of adverse ecological effects on non target species. For the assessment of triadimefon risks, the risk quotient ( RQ) method is used to compare exposure and measured toxicity values. Estimated environmental concentrations ( EECs) are divided by acute and chronic toxicity values. The RQs are compared to the Agency's levels of concern ( LOCs). These LOCs are the Agency's interpretive policy and are used to analyze potential risk to non target organisms and the need to consider regulatory action. These criteria are used to indicate when a pesticide's use as directed on the label has the potential to cause adverse effects on non target organisms. Appendix C of this document summarizes the LOCs used in this risk assessment.

Based on the toxicity data presented in the ecological effects assessment, the toxicity of triadimenol is equivalent to the toxicity of the parent triadimefon for aquatic species. Therefore, toxicity values for the parent triadimefon were used to calculate RQ values. In terrestrial environments, the degradate triadimenol is formed through microbial degradation in the soil subsurface and following plant uptake through plant metabolism. Our current exposure models only calculates surface residue values. Therefore, terrestrial organism RQ values were derived for triadimefon and not the degradate.

1. Non target Aquatic Animals and Plants Triadimefon surface water concentrations were predicted with the Tier II models PRZMEXAMS Five scenarios that consider food use application of liquid triadimefon ( via ground and aerial spray) were examined: apples ( Pennsylvania, North Carolina, and Oregon), berries ( Oregon), fruit ( California; used to model pear use) and grapes ( California). Non food use was modeled using the turf ( Pennsylvania and Florida) and Christmas tree ( Oregon) models. There are currently no PRZM EXAMS models to examine ornamental use.

One in ten year peak EECs were compared to acute toxicity endpoints to derive acute RQs and 1 in ten year 21 day and 60 day average EECs were compared to chronic toxicity endpoints to derive chronic RQs for fish and invertebrates, respectively. Acute and chronic RQs for freshwater fish and invertebrates are summarized in Tables 20 and 21, respectively. RQ values could not be derived for estuarine/ marine fish or invertebrates because of the lack of data. Due to the lack to toxicity data on vascular aquatic plants, no RQ values could be calculated for these species. However, RQs were calculated for non vascular aquatic plants using 1 in ten year peak EECs and EC 50 values. In addition, peak EECs were also compared to NOAEC values for non vascular plants to derive listed species RQs for this taxonomic group. RQ values for non vascular aquatic Page 56 of 241 plants are presented in Table 22.

a. Freshwater Fish and Invertebrates Table 20 lists the acute RQ values for freshwater fish and invertebrates exposed to triadimefon/ triadimenol. For freshwater fish and aquatic phase amphibians, the acute RQ values associated with all modeled use scenarios are less than the acute risk LOC ( RQ< 0.01). For freshwater invertebrates, the acute RQs for FL and PA turf ( maximum # of applications) exceed acute endangered species LOC, with values of 0.09 and 0.07, respectively. Additionally, the acute RQ for freshwater invertebrates exceeds the acute endangered species LOC for average golf course turf application ( 1.36 lb ai/ A, 26 applications, 14d interval), with an RQ of 0.05.

Table 21 presents the chronic RQ values for freshwater fish and invertebrates exposed to triadimefon/ triadimenol. For freshwater fish, aquatic phase amphibians, and invertebrates, the chronic RQs for FL and PA turf ( golf course, maximum application rates, maximum # of applications) exceed the Agency chronic LOC of 1. Additionally, the chronic LOC was exceeded for freshwater fish and invertebrates for application of triadimefon to FL golf course turf at the average application rate ( 1.36 lb ai/ A,, maximum # of applications). The freshwater fish LOC was exceeded for the average application rate PA golf course turf scenario ( maximum # of applications) and for the FL golf course turf average application rate scenario with only 6 applications ( 60d interval). RQ values ranged from 1.0  3.1.

Table 20. Acute risk quotients for freshwater fish and invertebrates exposed to triadimefon/ triadimenol Crop Application rate ( number of apps) Application method Peak EEC ( ppb) Risk Quotients Freshwater Fish LC50 = 4100 ppb Freshwater Invertebrate LC50 = 1600 ppb NC Apple ( 0.25 lb ai/ A, 3 apps, 7d interval) ground spray 3.3 < LOC < LOC aerial spray 4.3 < LOC < LOC OR Apple ( 0.25 lb ai/ A, 3 apps, 7d interval) ground spray 1.6 < LOC < LOC aerial spray 3.0 < LOC < LOC PA Apple ( 0.25 lb ai/ A, 3 apps, 7d interval) ground spray 4.4 < LOC < LOC aerial spray 5.5 < LOC < LOC CA Grape ( 0.1875, 3 apps, 14d interval) ground spray 1.0 < LOC < LOC aerial spray 1.3 < LOC < LOC NY Grape ( 0.1875, 3 apps, 14d interval) ground spray 2.6 < LOC < LOC aerial spray 3.5 < LOC < LOC CA fruit ( represents pears) ( 0.25 lb ai/ A, 3 apps, 7d interval) ground spray 0.5 < LOC < LOC aerial spray 2.0 < LOC < LOC Page 57 of 241 OR berries  ground spray ( 0.125 lb ai/ A, 7 apps, 28d interval) ground spray 1.7 < LOC < LOC OR Xmas Tree ( 0.25 lb ai/ A, 8 apps, 14d interval) ground spray 2.6 < LOC < LOC aerial spray 4.1 < LOC < LOC FL turf ( golf course application) ( 2.7 lb ai/ A, 26 apps, 14d interval) MAX ground spray ( no incorporation) 150.6 < LOC 0.09*

FL turf ( golf course application) ( 1.36 lb ai/ A, 26 apps, 14d interval) AVE ground spray ( no incorporation) 75.6 < LOC 0.05*

FL turf ( golf course application) a ( 2.7 lb ai/ A, 6 apps, 60d interval) MAX ground spray ( no incorporation) 54.4 < LOC < LOC FL turf ( golf course application) a ( 1.36 lb ai/ A, 6 apps, 60d interval) AVE ground spray ( no incorporation) 27.3 < LOC < LOC FL turf ( lawn & landscape) ( 1.36 lb ai/ A, 2 apps, 30d interval) ground spray 16.2 < LOC < LOC FL turf  granules ( consumer use) ( 1.31 lb ai/ A, 2 apps, 30d interval) broadcast 14.9 < LOC < LOC PA turf ( golf course application) ( 2.7 lb ai/ A, 13 apps, 14d interval) MAX ground spray 110.3 < LOC 0.07*

PA turf ( golf course application) ( 1.36 lb ai/ A, 13 apps, 14d interval) AVE ground spray 55.2 < LOC < LOC PA turf ( lawn & landscape) ( 1.36 lb ai/ A, 2 apps, 30d interval) ground spray 11.0 < LOC < LOC PA turf  granules ( consumer use) ( 1.31 lb ai/ A, 2 apps, 30d interval) broadcast ( no incorporation) 9.8 < LOC < LOC < LOC = below all Agency LOC (< 0.01) * exceeds Agency acute endangered species LOC of 0.05 a6 application, 60d interval scenario modeled for comparative purposes only Table 21. Chronic risk quotients for freshwater fish and invertebrates exposed to triadimefon/ triadimenol Crop Application rate ( number of apps) Application method 21 day EEC ( ppb) 60 day EEC ( ppb) Risk Quotients FW Fish NOAEC = 41 ppb FW Invert NOAEC = 52 ppb NC Apple ( 0.25 lb ai/ A, 3 apps, 7d interval) ground spray 2.9 2.3 < LOC < LOC aerial spray 3.6 3.1 < LOC < LOC OR Apple ( 0.25 lb ai/ A, 3 apps, 7d interval) ground spray 1.3 1.0 < LOC < LOC aerial spray 2.6 2.0 < LOC < LOC PA Apple ( 0.25 lb ai/ A, 3 apps, 7d interval) ground spray 3.7 3.2 < LOC < LOC Page 58 of 241 aerial spray 4.7 4.0 < LOC < LOC CA Grape ( 0.1875, 3 apps, 14d interval) ground spray 0.7 0.5 < LOC < LOC aerial spray 1.1 0.9 < LOC < LOC NY Grape ( 0.1875, 3 apps, 14d interval) ground spray 2.4 2.0 < LOC < LOC aerial spray 3.1 2.7 < LOC < LOC CA fruit ( represents pears) ( 0.25 lb ai/ A, 3 apps, 7d interval) ground spray 0.5 0.3 < LOC < LOC aerial spray 1.7 1.3 < LOC < LOC OR berries  ground spray ( 0.125 lb ai/ A, 7 apps, 28d interval) ground spray 1.5 1.3 < LOC < LOC OR Xmas Tree ( 0.25 lb ai/ A, 8 apps, 14d interval) ground spray 2.2 1.8 < LOC < LOC aerial spray 3.5 3.2 < LOC < LOC FL turf ( golf course application) ( 2.7 lb ai/ A, 26 apps, 14d interval) MAX ground spray ( no incorporation) 127.5 108.3 3.1* 2.1*

FL turf ( golf course application) ( 1.36 lb ai/ A, 26 apps, 14d interval) AVE ground spray ( no incorporation) 64.2 54.3 1.6* 1.0*

FL turf ( golf course application) ( 2.7 lb ai/ A, 6 apps, 60d interval) MAXa ground spray ( no incorporation) 45.5 34.2 1.1* < LOC FL turf ( golf course application) ( 1.36 lb ai/ A, 6 apps, 60d interval) AVEa ground spray ( no incorporation) 22.8 17.1 < LOC < LOC FL turf ( lawn & landscape) ( 1.36 lb ai/ A, 2 apps, 30d interval) ground spray 13.3 9.9 < LOC < LOC FL turf  granules ( consumer use) ( 1.31 lb ai/ A, 2 apps, 30d interval) broadcast 12.2 9.1 < LOC < LOC PA turf ( golf course application) ( 2.7 lb ai/ A, 13 apps, 14d interval) MAX ground spray ( no incorporation) 93.2 74.1 2.3* 1.4*

PA turf ( golf course application) ( 1.36 lb ai/ A, 13 apps, 14d interval) AVE ground spray ( no incorporation) 46.8 37.2 1.1* < LOC PA turf ( lawn & landscape) ( 1.36 lb ai/ A, 2 apps, 30d interval) ground spray ( no incorporation) 9.1 6.9 < LOC < LOC PA turf  granules ( consumer use) ( 1.31 lb ai/ A, 2 apps, 30d interval) broadcast ( no incorporation) 8.1 6.1 < LOC < LOC < LOC = below all Agency LOC (< 1.0) * Exceeds Agency chronic LOC of 1.0 a6 application, 60d interval scenario modeled for comparative purposes only Page 59 of 241 b. Estuarine/ Marine Fish and Invertebrates No RQ values were calculated for estuarine/ marine fish and invertebrates because no toxicity data was submitted to the Agency.

c. Aquatic Plants Table 22 lists the RQs for aquatic, non vascular plants potentially exposed to triadimefon/ triadimenol. For non listed non vascular plants, no acute RQs exceeded the Agency's LOC ( RQ< 1). For listed non vascular plants, the Agency's LOC was exceeded for the FL and PA turf scenarios ( golf course, maximum # of applications), with RQ values of 1.5 and 1.1, respectively.

Table 22. Acute non endangered and endangered species risk quotients for aquatic non vascular plants exposed to triadimefon Crop Application rate ( number of apps) Application method Peak EEC ( ppb) Risk Quotients Non endangered EC50 = 1710 ppb Endangered NOAEC = 100 ppb NC Apple ( 0.25 lb ai/ A, 3 apps, 7d interval) ground spray 3.3 < LOC < LOC aerial spray 4.3 < LOC < LOC OR Apple ( 0.25 lb ai/ A, 3 apps, 7d interval) ground spray 1.6 < LOC < LOC aerial spray 3.0 < LOC < LOC PA Apple ( 0.25 lb ai/ A, 3 apps, 7d interval) ground spray 4.4 < LOC < LOC aerial spray 5.5 < LOC < LOC CA Grape ( 0.1875, 3 apps, 14d interval) ground spray 1.0 < LOC < LOC aerial spray 1.3 < LOC < LOC NY Grape ( 0.1875, 3 apps, 14d interval) ground spray 2.6 < LOC < LOC aerial spray 3.5 < LOC < LOC CA fruit ( represents pears) ( 0.25 lb ai/ A, 3 apps, 7d interval) ground spray 0.5 < LOC < LOC aerial spray 2.0 < LOC < LOC OR berries  ground spray ( 0.125 lb ai/ A, 7 apps, 28d interval) ground spray 1.7 < LOC < LOC OR Xmas Tree ( 0.25 lb ai/ A, 8 apps, 14d interval) ground spray 2.6 < LOC < LOC aerial spray 4.1 < LOC < LOC FL turf ( golf course application) ( 2.7 lb ai/ A, 26 apps, 14d interval) MAX ground spray ( no incorporation) 150.6 < LOC 1.5 Crop Application rate ( number of apps) Application method Peak EEC ( ppb) Risk Quotients Non endangered EC50 = 1710 ppb Endangered NOAEC = 100 ppb Page 60 of 241 FL turf ( golf course application) ( 1.36 lb ai/ A, 26 apps, 14d interval) AVE ground spray ( no incorporation) 75.6 < LOC < LOC FL turf ( golf course application) ( 2.7 lb ai/ A, 6 apps, 60d interval) MAXa ground spray ( no incorporation) 54.4 < LOC < LOC FL turf ( golf course application) ( 1.36 lb ai/ A, 6 apps, 60d interval) AVEa ground spray ( no incorporation) 27.3 < LOC < LOC FL turf ( lawn & landscape) ( 1.36 lb ai/ A, 2 apps, 30d interval) ground spray 16.2 < LOC < LOC FL turf  granules ( consumer use) ( 1.31 lb ai/ A, 2 apps, 30d interval) broadcast 14.9 < LOC < LOC PA turf ( golf course application) ( 2.7 lb ai/ A, 13 apps, 14d interval) MAX ground spray ( no incorporation) 110.3 < LOC 1.1*

PA turf ( golf course application) ( 2.7 lb ai/ A, 13 apps, 14d interval) AVE ground spray ( no incorporation) 55.2 < LOC < LOC PA turf ( lawn & landscape) ( 1.36 lb ai/ A, 2 apps, 30d interval) ground spray 11.0 < LOC < LOC PA turf  granules ( consumer use) ( 1.31 lb ai/ A, 2 apps, 30d interval) broadcast ( no incorporation) 9.8 < LOC < LOC * Exceeds Agency LOC of 1.0 a6 application, 60d interval scenario modeled for comparative purposes only 2. Non target Terrestrial Animals The EEC values for terrestrial exposure for spray applications were derived from the Kenaga nomogram, as modified by Fletcher et al., ( 1994), based on a large set of actual field residue data. For spray applications, EECs were calculated for six different crop scenarios ( apples/ pears, raspberries, grapes, golf course turf, residential/ commercial turf, and Christmas trees) with application rates ranging from 0.125 lb ai/ A to 2.7 lb ai/ A and varying number of applications and application intervals. Typically, risk quotients are based on the most sensitive LC 50 and NOAEC values for birds and LD 50 and NOAEL for mammals ( based on laboratory rat studies). For granular applications, the mg ai/ ft2 values are compared to LD 50 values to estimate the potential for mortality. However, definitive avian LD 50 values were not available for triadimefon ( no mortalities or signs of toxicity were seen in the study at the highest exposure level), so dose based RQ values were not calculated. However, an subacute dietary study demonstrated an LC 50 of 8392 ppm, which was used to calculate acute dietary based RQ values for birds. Page 61 of 241 a. Birds  Spray Application Table 23 summarizes the acute and chronic avian dietary based RQs for various triadimefon uses. Agency acute LOCs are exceeded only for golf course turf with the maximum application rate ( 26 applications, 14d interval and 6 applications, 60d interval) as well as the average application rate ( 26 applications, 14d interval). The acute restricted use, and endangered species LOC are exceeded for birds that feed on short grass, tall grass, broadleaf plants, and small insects.

Avian dietary based chronic RQ values exceed the Agency LOC of 1 for birds that feed on short grass, tall grass, broadleaf plants, and small insects for all modeled scenarios and application rates. RQ values range from 1.6  133.7. Additionally, the chronic LOC is exceeded for birds that feed on fruits, pods, seeds, and large insects for all golf course scenarios ( 26 applications, 6 applications, 1 application at both maximum and average use rates) and residential/ commercial/ recreational turf scenarios.

Table 23. Avian dietary based acute and chronic risk quotients for selected uses of nongranular triadimefon ( based on LC 50 of 8392 mg/ kg diet and NOAEC of 50 mg/ kg diet) based on upper bound Kenaga values.

Use Food items Upper Bound EEC ( mg/ kg) Acute dietary based RQ1 ( EEC/ LC50) Chronic dietary based RQ2 ( EEC/ NOAEC)

Apples & Pears ( 0.25 lb ai/ A, 3 applications, 7d interval) Short grass 157.7 < LOC 7.9****

Tall grass 72.28 < LOC 3.6****

Broadleaf plants/ small insects 88.71 < LOC 4.4****

Fruits, pods, seeds, large insects 9.86 < LOC < LOC Raspberries ( 0.125 lb ai/ A, 7 applications, 28d interval) Short grass 69.03 < LOC 3.5****

Tall grass 31.64 < LOC 1.6****

Broadleaf plants/ small insects 38.83 < LOC 1.9****

Fruits, pods, seeds, large insects 4.31 < LOC < LOC Grapes ( 0.1875 lb ai/ A, 3 applications, 14d interval) Short grass 104.95 < LOC 5.2****

Tall grass 48.10 < LOC 2.4****

Broadleaf plants/ small insects 59.03 < LOC 2.9****

Fruits, pods, seeds, large insects 6.56 < LOC < LOC Use Food items Upper Bound EEC ( mg/ kg) Acute dietary based RQ1 ( EEC/ LC50) Chronic dietary based RQ2 ( EEC/ NOAEC)

Page 62 of 241 Golf Course Turf ( 2.7 lb ai/ A, 26 applications, 14d interval) MAX use rate Short grass 2674.1 0.3** 133.7****

Tall grass 1225.6 0.2** 61.3****

Broadleaf plants/ small insects 1504.2 0.2** 75.2****

Fruits, pods, seeds, large insects 167.1 < LOC 8.4****

Golf Course Turf ( 2.7 lb ai/ A, 1 application) MAX use rate Short grass 648.0 < LOC 32.4****

Tall grass 297.0 < LOC 14.9****

Broadleaf plants/ small insects 364.5 < LOC 18.2****

Fruits, pods, seeds, large insects 40.5 < LOC 2.0****

Golf Course Turf ( 2.7 lb ai/ A, 6 applications, 60d interval) a MAX use rate Short grass 931.3 0.1* 46.6****

Tall grass 426.8 0.1* 21.3****

Broadleaf plants/ small insects 523.9 0.1* 26.2****

Fruits, pods, seeds, large insects 58.2 < LOC 2.9****

Golf Course Turf ( 1.36lb ai/ A, 26 applications, 14d interval) AVE use rate Short grass 1347.0 0.2** 67.4****

Tall grass 617.4 0.1* 30.9****

Broadleaf plants/ small insects 757.7 0.1* 37.9****

Fruits, pods, seeds, large insects 84.2 < LOC 4.2****

Golf Course Turf ( 1.36lb ai/ A, 1 application) AVE use rate Short grass 326.4 < LOC 16.3****

Tall grass 149.6 < LOC 7.5****

Broadleaf plants/ small insects 183.6 < LOC 9.2****

Fruits, pods, seeds, large insects 20.4 < LOC 1.0****

Residential/ Commercial/& Recreational Turf ( 1.36 lb ai/ A, 2 applications, 14d interval) Short grass 573.8 < LOC 28.7****

Tall grass 263.0 < LOC 13.1****

Broadleaf plants/ small insects 322.7 < LOC 16.1****

Fruits, pods, seeds, large insects 35.9 < LOC 1.8**** Use Food items Upper Bound EEC ( mg/ kg) Acute dietary based RQ1 ( EEC/ LC50) Chronic dietary based RQ2 ( EEC/ NOAEC)

Page 63 of 241 Christmas Trees ( 0.25 lb ai/ A, 8 applications, 14 day interval) Short grass 220.8 < LOC 11.0****

Tall grass 101.2 < LOC 5.1****

Broadleaf plants/ small insects 124.2 < LOC 6.2****

Fruits, pods, seeds, large insects 13.8 < LOC < LOC 1Kenaga EEC ( mg/ kg food item) / LC50 ( mg/ kg diet) 2Kenaga EEC ( mg/ kg food item) / NOAEC ( mg/ kg diet) * exceeds LOC for acute risk to listed species ( RQ $ 0.1) ** exceeds LOC for acute risk to listed species and restricted use ( RQ $ 0.2) *** exceeds LOC for acute risk to listed species, restricted use, and acute risk ( RQ $ 0.5) **** exceeds LOC for chronic risk ( RQ = 1.0) a6 application, 60d interval scenario modeled for comparative purposes only b. Mammals  Spray Application Table 24 summarizes the mammalian dose based acute RQs for all uses of triadimefon. Acute, acute restricted use and/ or listed species acute risk LOCs are exceeded for turf ( golf course and residential/ commercial/ recreation) for mammals that feed on short grass, tall grass, broadleaf plants, and small insects. The acute listed species LOC is exceeded for all sizes of mammals that feed on short grass, 15 and 35g mammals that feed on broadleaf plants and small insects, and 15g mammals that feed on tall grass for triadimefon use on apples and pears. Use of triadimefon on grapes leads to exceedances of the acute listed species LOC for 15 and 35g mammals that feed on short grass. Additionally, the acute listed species LOC is exceeded for mammals that feed on short grass for Christmas tree triadimefon application. RQ values range from 0.1 to 1.7.

Table 25 presents the mammalian dose based chronic RQs for triadimefon use. Chronic LOCs are exceeded for all sizes of mammals that consume short grass, tall grass, broadleaf plants, and small insects for all modeled scenarios and application rates. Additionally, Agency LOCs are exceeded for mammals that feed on fruits, pods, and large insects for all scenarios except raspberries. Turf use results in exceedances for mammals that feed on seeds. Chronic RQ values range from 1.1  464.0.

Table 26 summarizes the mammalian dietary based chronic RQs for triadimefon uses. Chronic LOCs are exceeded for mammals that consume short grass, tall grass, broadleaf plants, and small insects for uses on apples, turf ( golf course and residential/ commercial/ recreational), and Christmas trees, with chronic RQs ranging from 1.4  53.5. Risk quotients based on dietary exposure levels are provided for comparison purposes.

Table 24. Mammalian dose based acute risk quotients for selected uses of non granular triadimefon ( based on triadimenol LD 50 of 689 mg/ kg in rats) based on upper bound Kenaga values. Page 64 of 241 Use Body Weight ( g) Adjusted LD50 Mammalian Dose based Acute Risk Quotients1 Short grass Tall grass Broadleaf plants/ small insects Fruits/ pods/ large insects Seeds Apples & Pears ( 0.25 lb ai/ A, 3 applications, 7d interval) 15 1514.3 0.1 0.1 0.1 < LOC < LOC 35 1225.2 0.1 < LOC 0.1 < LOC < LOC 1000 530.0 0.1 < LOC < LOC < LOC < LOC Raspberries ( 0.125 lb ai/ A, 7 applications, 28d interval) 15 1514.3 < LOC < LOC < LOC < LOC < LOC 35 1225.2 < LOC < LOC < LOC < LOC < LOC 1000 530.0 < LOC < LOC < LOC < LOC < LOC Grapes ( 0.1875 lb ai/ A, 3 applications, 14d interval) 15 1514.3 0.1 < LOC < LOC < LOC < LOC 35 1225.2 0.1 < LOC < LOC < LOC < LOC 1000 530.0 < LOC < LOC < LOC < LOC < LOC Golf Course Turf ( 2.7 lb ai/ A, 26 applications, 14d interval) MAX rate 15 1514.3 1.7*** 0.8*** 1.0*** 0.1* < LOC 35 1225.2 1.4*** 0.7*** 0.8*** 0.1* < LOC 1000 530.0 0.8*** 0.4** 0.4** 0.1* < LOC Golf Course Turf ( 2.7 lb ai/ A, 1 application) MAX rate 15 1514.3 0.4** 0.2** 0.2** < LOC < LOC 35 1225.2 0.4** 0.2** 0.2* < LOC < LOC 1000 530.0 0.2** 0.1* 0.1* < LOC < LOC Golf Course Turf ( 2.7 lb ai/ A, 6 applications, 60d interval) a MAX rate 15 1514.3 0.6*** 0.3** 0.3** < LOC < LOC 35 1225.2 0.5*** 0.2** 0.3** < LOC < LOC 1000 530.0 0.3** 0.1* 0.2** < LOC < LOC Golf Course Turf ( 1.36 lb ai/ A, 26 applications, 14d interval) AVE rate 15 1514.3 0.9*** 0.4** 0.5*** 0.1* < LOC 35 1225.2 0.7*** 0.3** 0.4** 0.1* < LOC 1000 530.0 0.4** 0.2** 0.2** < LOC < LOC Golf Course Turf ( 1.36 lb ai/ A, 1 application) AVE rate 15 1514.3 0.2** 0.1* 0.1* < LOC < LOC 35 1225.2 0.2** 0.1* 0.1* < LOC < LOC 1000 530.0 0.1* < LOC 0.1* < LOC < LOC Residential/ Commercial/ & Recreational Turf ( 1.36 lb ai/ A, 2 applications, 14d interval) 15 1514.3 0.4** 0.2** 0.2** < LOC < LOC 35 1225.2 0.3** 0.1* 0.2** < LOC < LOC 1000 530.0 0.2** 0.1* 0.1* < LOC < LOC Page 65 of 241 Christmas Trees ( 0.25 lb ai/ A, 8 applications, 14 day interval) 15 1514.3 0.1* 0.1* 0.1* < LOC < LOC 35 1225.2 0.1* 0.1* 0.1* < LOC < LOC 1000 530.0 0.1* < LOC < LOC < LOC < LOC 1Acute daily exposure ( mg/ kg bw) / adjusted LD50 ( mg/ kg bw) * exceeds LOC for acute risk to listed species ( RQ $ 0.1) ** exceeds LOC for acute risk to listed species and restricted use ( RQ $ 0.2) *** exceeds LOC for acute risk to listed species, restricted use, and acute risk ( RQ $ 0.5) a6 application, 60d interval scenario modeled for comparative purposes only Table 25. Mammalian dose based chronic risk quotients for selected uses of non granular triadimefon ( based on rat NOAEL of 2.5 mg/ kg body weight and upper bound Kenaga values).

Use Body Weight ( g) Adjusted NOAEL Dose based Chronic Risk Quotients1 Short grass Tall grass Broadleaf plants/ small insects Fruits/ p ods/ large insects Seeds Apples & Pears ( 0.25 lb ai/ A, 3 applications, 7d interval) 15 5.5 27.4* 12.5* 15.4* 1.7* < LOC 35 4.5 23.4* 10.7* 13.2* 1.5* < LOC 1000 1.9 12.5* 5.7* 7.1* < LOC < LOC Raspberries ( 0.125 lb ai/ A, 7 applications, 28d interval) 15 5.5 12.0* 5.5* 6.7 < LOC < LOC 35 4.5 10.2* 4.7* 5.8* < LOC < LOC 1000 1.9 5.5* 2.5* 3.1* < LOC < LOC Grapes ( 0.1875 lb ai/ A, 3 applications, 14d interval) 15 5.5 18.2* 8.4* 10.2* 1.1* < LOC 35 4.5 15.6* 7.1* 8.8* 1.0* < LOC 1000 1.9 8.3* 3.8* 4.7* < LOC < LOC Golf Course Turf ( 2.7 lb ai/ A, 26 applications, 14d interval) MAX rate 15 5.5 464.0* 212.7* 261.0* 29.0* 6.4*

35 4.5 396.4* 181.7* 223.0* 24.8* 5.5*

1000 1.9 212.5* 97.4* 119.5* 13.3* 3.0*

Golf Course Turf ( 2.7 lb ai/ A, 1 application) MAX rate 15 5.5 112.4* 51.5* 63.3* 7.0* 1.6*

35 4.5 96.1* 44.0* 54.0* 6.0* 1.3*

1000 1.9 51.5* 23.6* 29.0* 3.2* < LOC Golf Course Turf ( 2.7 lb ai/ A, 6 applications, 60d interval) a MAX rate 15 5.5 161.6* 74.1* 90.9* 10.1* 2.2*

35 4.5 138.0* 63.3* 77.7* 8.6* 1.9*

1000 1.9 74.0* 33.9* 41.6* 4.6* 1.0* Use Body Weight ( g) Adjusted NOAEL Dose based Chronic Risk Quotients1 Short grass Tall grass Broadleaf plants/ small insects Fruits/ p ods/ large insects Seeds Page 66 of 241 Golf Course Turf ( 1.36 lb ai/ A, 26 applications, 14d interval) AVE rate 15 5.5 233.7* 107.1* 131.5* 14.6* 3.3*

35 4.5 199.7* 91.5* 112.3* 12.5* 2.8*

1000 1.9 107.0* 49.1* 60.2* 6.7* 1.5*

Golf Course Turf ( 1.36 lb ai/ A, 1 application) AVE rate 15 5.5 56.6* 26.0* 31.9* 3.5* < LOC 35 4.5 48.4* 22.2* 27.2* 3.0* < LOC 1000 1.9 25.9* 11.9* 14.6* 1.6* < LOC Residential/ Commercia l/& Recreational Turf ( 1.36 lb ai/ A, 2 applications, 14d interval) 15 5.5 99.6* 45.6* 56.0* 6.2* 1.4*

35 4.5 85.0* 39.0* 47.8* 5.3* 1.2*

1000 1.9 45.6* 20.9* 25.6* 2.9* < LOC Christmas Trees ( 0.25 lb ai/ A, 8 applications, 14 day interval) 15 5.5 38.3* 17.6* 21.6* 2.4* < LOC 35 4.5 32.7* 15.0* 18.4* 2.1* < LOC 1000 1.9 17.5* 8.0* 9.9* 1.1* < LOC 1EEC ( mg/ kg bw)/ NOAEL ( mg/ kg bw) * Exceeds the Agency chronic LOC of 1.0 a6 application, 60d interval scenario modeled for comparative purposes only Page 67 of 241 Table 26. Mammalian dietary based chronic risk quotients for selected uses of non granular triadimefon ( based on rat NOAEC of 50mg/ kg diet and upper bound Kenaga values).

Use Dietary based Chronic Risk Quotients1 Short grass Tall grass Broadleaf plants/ small insects Fruits/ pods/ large insects Apples ( 0.25 lb ai/ A, 3 applications, 7d interval) 3.2* 1.5* 1.8* < LOC Raspberries ( 0.125 lb ai/ A, 7 applications, 28d interval) 1.4* < LOC < LOC < LOC Grapes ( 0.1875 lb ai/ A, 3 applications, 14d interval) 2.1* < LOC 1.2* < LOC Golf Course Turf ( 2.7 lb ai/ A, 26 applications, 14d interval) 53.5* 24.5* 30.1* 3.3*

Golf Course Turf ( 2.7 lb ai/ A, 1 application) 13.0* 5.9* 7.3* < LOC Golf Course Turf ( 2.7 lb ai/ A, 6 applications, 60d interval) a 18.6* 8.5* 10.5* 1.2*

Golf Course Turf ( 1.36 lb ai/ A, 26 applications, 14d interval) 26.9* 12.4* 15.2* 1.7*

Golf Course Turf ( 1.36 lb ai/ A, 1 application) 6.5* 3.0* 3.7* < LOC Residential/ Commercial/& Recreational Turf ( 1.36 lb ai/ A, 2 applications, 14d interval) 11.5* 5.3* 6.5* < LOC Christmas Trees ( 0.25 lb ai/ A, 8 applications, 14 day interval) 4.4* 2.0* 2.5* < LOC 1EEC ( mg/ kg food item) / NOAEC ( mg/ kg diet) * Exceeds the Agency chronic LOC of 1.0 a6 application, 60d interval scenario modeled for comparative purposes only c. Granular Application The predicted triadimefon granular EEC value resulting from residential application at a rate of 1.31 lb ai/ A ( 30 day interval, 2 applications per year) is 14 mg ai/ ft2. Definitive RQ values for birds could not be derived because LD 50 values were set as greater than the highest triadimefon concentration tested, and there were to mortalities at any test level. Mammalian acute risk quotients based on granular triadimefon application are presented in Table 27. Page 68 of 241 Table 27. Mammalian risk quotients resulting from use of granular triadimefon on residential/ commercial turf ( 1.31 lb ai/ A, 30d interval, 2 applications)

Mammal size EEC ( mg ai/ ft2) LD50 ( mg/ kg body weight) Adjusted LD50 ( mg/ kg body weight) RQ 15g 14 689 1514.3 0.6***

35g 14 689 1225.2 0.3**

1000g 14 689 530.0 < LOC * exceeds LOC for acute risk to listed species ( RQ $ 0.1) ** exceeds LOC for acute risk to listed species and restricted use ( RQ $ 0.2) *** exceeds LOC for acute risk to listed species, restricted use, and acute risk ( RQ $ 0.5)

d. RQs Based on Mean Kenaga Residues Appendix D presents acute and chronic avian and mammalian RQs using mean Kenaga residue values. These RQs do not for the basis of risk conclusion for birds and mammals but are provided for comparison purposes. Using the mean Kenaga residue values for calculating Rqs would not protect birds and mammals that consume food items that have residues on the higher end of the residue distribution. An analysis of the residue distribution for the different food items using input values from Fletcher et al. ( 1994) and assuming a log normal distribution of residues on food items was conducted. The analysis shows that the mean Kenaga values range from about the 62  87th percentile, indicating that up to 38% of the higher end food item estimates are not captured by using the mean Kenaga values. Importantly, if the actual distribution differed from log normal, these estimates could change substantially. The implications and utility of these values is described further in the Risk Description Section below.

3. Non target Terrestrial Plants No terrestrial plant toxicity data were submitted to the Agency. Several studies ( see Section III. C. 2. f) obtained through the ECOTOX database demonstrated that triadimefon may have negative effects on both monocot and dicot non target terrestrial plants. Although the studies did not provide adequate information to quantitatively calculate RQ values for non target terrestrial plants, further terrestrial plant studies must be performed and submitted to the Agency as part of the data requirements.

B. Risk Description  Interpretation of Direct Effects The results of this screening level risk assessment suggest the potential for direct adverse acute effects to freshwater invertebrates and listed non vascular aquatic plants at the maximum and average application rates of non granular triadimefon ( golf course turf, 2.7 lb ai/ A and 1.36 lb ai/ A) and maximum number of yearly applications ( 26, 14 day interval). Additionally, there are potential direct adverse acute effects to listed and non listed birds based on dietary exposure at this same application rates ( 26 applications, 14 day interval), as well as for the maximum rate with 6 applications ( 60 day interval). Acute effects may also occur in mammals ( listed and non listed) exposed to non granular triadimefon applied to apples, pears, grapes, golf course turf, Christmas trees, and residential/ commercial/ recreational turf, as well as granular triadimefon applied to residential/ commercial turf. Chronic effects may occur to freshwater fish and invertebrates at the Page 69 of 241 highest application rates of non granular triadimefon ( see above), and to birds and mammals at all application rates and scenarios. A description of the potential direct effects associated with exposure to triadimefon is discussed for each of the taxonomic groups below. Table 28 provides a summary of the direct effects for Federally listed species of concern, including the range of RQ values and the acute dose response slopes used for probit analysis, as applicable.

Table 28. Summary of Direct Effects for Federally Listed Species Listed Species Taxonomic Group of Concern Direct Effects Slope RQ range Freshwater fish Acute: none Chronic: reduced growth1 4.3 ( 95% CI: 2.8  5.8) NA < LOC < LOC  3.1 Freshwater invertebrates Acute: mortality/ immobilization1 Chronic: reduced adult length1 4.3 ( 95% CI: 2.2  6.4) NA < LOC  0.1 < LOC  2.1 Non vascular aquatic plants Acute: reduced cell density NA < LOC  1.5 Birds Acute: reduced survival 3 Chronic: reduced egg viability, viable embryos, 14 d survivors 4.52 ( 95% CI: 2  9) NA < LOC  0.3 < LOC  133.7 Mammals Acute: reduced survival Chronic: reduced pup weight 4.5 ( 95% CI: 2  9) NA < LOC  1.7 < LOC  464.0 1Exceedances for FL and PA turf scenarios, maximum and average use rates 2Default slope value and 95% confidence intervals were used ( Urban and Cook, 1986) 3Exceedances for golf course turf scenario, maximum and average use rate, 26 and 6 applications < LOC = below all Agency LOC (< 0.1)

1. Risks to Aquatic Organisms and Plants The risk assessment for aquatic species is based on data from both triadimefon and its major degradate, triadimenol. Input parameters used to derive aquatic EEC values reflect total residues ( parent + triadimenol). Review of triadimenol aquatic toxicity values indicate that this degradate is unlikely to cause significant toxic effects. Therefore, risk quotients for aquatic organisms were calculated using triadimefon toxicity values.

a. Freshwater Fish Risk quotients indicate that there is a potential for chronic, but not acute, effects to freshwater fish at the Agency's level of concern. Chronic LOC exceedances occur for the 2.7 lb ai/ A ( maximum) and 1.36 lb ai/ A ( average) application of non granular triadimefon to golf course turf, for both the Florida turf ( 26 applications, 14 day intervals) and Pennsylvania turf ( 13 applications, 14 day intervals) scenarios in PRZM EXAMS. Additionally, there are chronic exceedances for the maximum use rate ( 2.7 lb ai/ A) with 6 applications ( 60 day interval) for the FL turf scenario. No exceedances occurred based on granular triadimefon application.

The high number of applications modeled for triadimefon golf course use were based on the lack of language specifying the maximum number of applications per year; the only label specification is an application interval of 14 days. States with a year round growing season for turf, represented by the Florida turf scenario, have 26 potential applications per year according to the Page 70 of 241 label, whereas more temperate climates ( represented by the Pennsylvania turf scenario) with shorter turf growing seasons could potentially apply triadimefon approximately 13 times. It should be noted that there remains potential for chronic risk to freshwater fish 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).

b. Estuarine/ Marine Fish Acute risk to estuarine/ marine fish is unlikely, based on the results of the screening level assessment demonstrating no acute risks to freshwater fish. However, no data were submitted to the Agency for estuarine/ marine fish, and therefore risk to these species cannot be precluded. No chronic estuarine/ marine fish toxicity data were submitted or located in the open literature for triadimefon; therefore, chronic risks associated with estuarine/ marine fish exposure are unknown.

c. Freshwater Invertebrates As detailed above, acute endangered species LOCs are exceeded for freshwater invertebrates based on the application of non granular triadimefon to golf course turf, for both the Florida turf ( 26 applications, 14 day intervals) and Pennsylvania turf ( 13 applications, 14 day intervals) scenarios in PRZM EXAMS at the maximum use rate of 2.7 lb ai/ A. Additionally, the acute endangered species LOC is exceeded based on the average use rate of 1.36 lb ai/ A and the Florida turf scenario ( 16 applications, 14 day intervals). Chronic LOCs are also exceeded for freshwater invertebrates based on these same golf course scenarios. No exceedances occurred based on granular triadimefon application.

The high number of applications modeled for triadimefon golf course use were based on the lack of language specifying the maximum number of applications per year; the only label specification is an application interval of 14 days. States with a year round growing season for turf, represented by the Florida turf scenario, have 26 potential applications per year according to the label, whereas more temperate climates ( represented by the Pennsylvania turf scenario) with shorter turf growing seasons could potentially apply triadimefon approximately 13 times. It should be noted that there remains potential for chronic risk to freshwater invertebrates with only 6 applications of triadimefon per year based on the FL scenario, and 11 applications per year based on the PA scenario ( 2.7 lb ai/ A; 14 day interval). Acute LOCs are exceeded with only 7 applications using the FL turf scenario.

d. Estuarine/ Marine Invertebrates No acute or chronic estuarine/ marine toxicity data were submitted or located in the open literature for triadimefon; therefore, the risks associated with estuarine/ marine invertebrate exposure to this chemical are unknown.

e. Aquatic Plants Based on the predicted EECs for triadimefon use on golf course turf ( Florida and Pennsylvania scenarios in PRZM EXAMS) and available toxicity data, the endangered species LOC is exceeded for non vascular aquatic plants. No aquatic vascular plant toxicity data was submitted or located in the open literature for triadimefon; therefore, the potential risk associated with non Page 71 of 241 vascular aquatic plant exposure to this chemical are unknown. No exceedances for non vascular aquatic plants occurred based on granular triadimefon application.

The high number of applications modeled for triadimefon golf course use were based on the lack of language specifying the maximum number of applications per year; the only label specification is an application interval of 14 days. States with a year round growing season for turf, represented by the Florida turf scenario, have 26 potential applications per year according to the label, whereas more temperate climates ( represented by the Pennsylvania turf scenario) with shorter turf growing seasons could potentially apply triadimefon approximately 13 times. It should be noted that there remains potential for acute endangered species risk to aquatic nonvascular 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).

2. Risks to Terrestrial Organisms and Plants a. Birds i. Discussion of Potential Risks Avian mortality, based on acute exposure to both non granular and granular applications of triadimefon is unlikely based on acute toxicity tests showing no mortality to both mallard duck and bobwhite quail at the highest doses tested ( 5000 and 2000 mg/ kg bw, respectively) ( MRID 071469). Therefore, dose based RQ values could not be calculated for birds. However, subacute dietary studies demonstrated an LC 50 of 8392 ppm diet in bobwhite quail. Based on this endpoint, the dietary based acute endangered species LOC is exceeded for golf course application ( maximum and average application rates, 26 applications and 6 applications) of non granular triadimefon on all food items, and the restricted use LOC is exceeded on short grass. It should be noted that the avian dietary acute LOC is still exceeded with only two golf course applications of triadimefon ( 2.7 lb ai/ A, 14 day interval).

Chronic risks to birds from non granular triadimefon application were evaluated using a bobwhite quail NOAEC of 20 ppm, based on an increase in eggs cracked, reduction in fertile eggs, viable embryos, hatchlings, and 14 day survival. Based on this value, dietary based chronic RQ values exceed the Agency LOC of 1 for birds that feed on short grass, tall grass, broadleaf plants, and small insects for all modeled scenarios and application rates. RQ values range from 1.6  133.7. Additionally, the chronic LOC is exceeded for birds that feed on fruits, pods, seeds, and large insects for all golf course scenarios ( 26 applications, 6 applications, 1 application at both maximum and average use rates) and residential/ commercial/ recreational turf scenarios. A onetime application of 0.08 lb ai/ A 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. Page 72 of 241 ii. Spray Drift The AgDrift model was used to calculate the distance from the edge of a field required to bring spray drift deposition below the LOC of 1 for chronic risk to birds. Spray drift distances were calculated based on short grass Kenaga EEC values using an adjusted application rate to account for the limitations of the AgDrift model. Spray drift distances are presented in Table 29 below. Spray drift area ranges from 16  108 feet for aerial application and 3.3  144 for ground spray.

Table 29. Avian Spray Drift Calculations Use Adjusted Application Rate1 Short grass upper bound EEC ( mg/ kg) Fraction of applied2 Buffer distance ( feet)

Aerial Spray Ground Spray Apples ( 0.25 lb ai/ A, 3 applications, 7d interval) 0.66 lb ai/ A 157.7 0.127 75.5 9.8 Raspberries ( 0.125 lb ai/ A, 7 applications, 28d interval) 0.29 lb ai/ A 69.0 0.29 16.4 3.3 Grapes ( 0.1875 lb ai/ A, 3 applications, 14d interval) 0.44 lb ai/ A 105.0 0.19 36.1 6.6 Golf Course Turf ( 2.7 lb ai/ A, 26 applications, 14d interval) 11.3 lb ai/ A 2703.9 0.007 NA 144.4 Golf Course Turf ( 2.7 lb ai/ A, 1 application) 2.7 lb ai/ A 648.0 0.03 NA 29.5 Residential, Commercial, & Recreational Turf ( 1.36 lb ai/ A, 2 applications, 14d interval) 2.4 lb ai/ A 573.8 0.03 NA 29.5 Christmas Trees ( 0.25 lb ai/ A, 8 applications, 14d interval) 0.92 lb ai/ A 220.8 0.09 108.3 13.1 1Adjusted rate is short grass EEC/ 240 to account for the ability of AgDrift to only make calculations based on a single application 2 Fraction of EEC needed to generate an RQ = 1.0 ( LOC); [ EEC of 20 mg/ kg]

b. Mammals i. Discussion of Potential Risks The following dose based acute LOCs are exceeded for mammals following the application of non granular triadimefon:

Golf course turf ( 2.7 lb ai/ A, 26 applications) ° acute risk, acute restricted use, and acute endangered species LOCs for all sized mammals that feed on short grass, 15g mammals that feed on tall grass, and 15g Page 73 of 241 and 35g mammals that feed on broadleaf plants and small insects. ° acute restricted use and acute endangered species LOCs for 35g and 1000g mammals that feed on tall grass and 1000g mammals that feed on broadleaf plants and small insects Golf course turf ( 2.7 lb ai/ A, 1 application) ° acute restricted use and acute endangered species LOCs for 15g and 35g mammals that feed on short grass, and 15g mammals that feed on broadleaf plants and small insects ° acute endangered species LOCs for 1000g mammals that feed on short grass, 15g and 35g mammals that feed on tall grass, and 35g mammals that feed on broadleaf plants and small insects. Residential/ Commercial & Recreational turf ( 1.36 lb ai/ A, 2 applications, 14d interval) ° acute restricted use and acute endangered species LOCs for 15g and 35g mammals that feed on short grass ° acute endangered species LOCs for 1000g mammals that feed on short grass, and 15g and 35g mammals that feed on tall grass, broadleaf plants, and small insects Christmas Trees ( 0.25 lb ai/ A, 8 applications, 14d intervals) ° acute endangered species LOC for 15g and 35g mammals that feed on short grass, and 15g mammals that feed on broadleaf plants and small insects. Apples & Pears ( 0.25 lb ai/ A, 3 applications, 7d interval) ° acute endangered species LOC for 15g, 35g, and 1000g mammals that feed on short grass, 15g and 35g mammals that feed on broadleaf plants and small insects, and 15g mammals that feed on tall grass Grapes ( 0.1875 lb ai/ A, 3 applications, 14d interval) ° acute endangered species LOC for 15g and 35g mammals that feed on short grass Acute restricted use and endangered species LOCs were also exceeded for the use of granular triadimefon on residential/ commercial turf at an application of 1.31 lb ai/ A ( 2 applications, 30d interval) based on the LD 50 / ft2 calculation for 15g and 35g mammals.

Both dietary based and dose based chronic RQ values were calculated for mammals exposed to triadimefon. Dietary RQ values were calculated by directly comparing the concentration of a pesticide administered orally to laboratory rats in a dietary study to the concentration of a pesticide on potential food items. Dietary RQs do not account for the fact that smaller sized animals need to consume more food in terms of body weight than to larger sized animals, or that differential amounts of food may be consumed based on nutritional value and water percentage of the feed. Dose based RQs incorporate the ingestion rate adjusted exposure from the various food items to the different weight classes of animals ( for mammals, 15g, 35g, and 1000g) and the weight class scaled toxicity endpoints.

Dose based chronic risks to mammals from non granular triadimefon application were evaluated using a laboratory rat offspring NOAEL of 50 ppm ai based on 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). Based on this value, a NOAEC of 2.5 mg/ kg body weight Page 74 of 241 was calculated to adjust for rat food intake and used in the RQ calculations. Chronic dose based LOCs are exceeded for all sizes of mammals that feed on short grass, tall grass, broadleaf plants, and small insects for all crops and at all application rates. Additionally, the LOC is exceeded for mammals that also feed on fruits, pods, large insects, and seeds for turf applications ( golf course and residential/ commercial & recreational) at all application rates. The mammalian dose based chronic RQ values range from < LOC to 464. A one time application of 0.025 lb ai/ A would be required to achieve chronic dose based RQ values for mammals that are lower than the Agency LOC of 1.0. This value is approximately 108 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 99% in order to achieve an RQ value below the LOC.

Dietary based chronic risks to mammals from non granular triadimefon application were evaluated using the laboratory rat NOAEC of 50 ppm ai. LOCs were exceeded for all applications at all rates for mammals that feed on short grass. LOCs were also exceeded for mammals that feed on tall grass, broadleaf plants, and small insects for the apple, golf course turf, residential/ commercial & recreational turf, and Christmas tree scenarios. Additionally, the chronic LOC was exceeded for mammals that feed on fruits, pods, and large insects based on the 26 application golf course turf scenario.

ii. Spray Drift The AgDrift model was used to calculate the distance from the edge of a field required to bring spray drift deposition below the LOC of 1 for chronic risk to mammals. Spray drift distances were calculated based on short grass Kenaga EEC values using an adjusted application rate to account for the limitations of the AgDrift model. Spray drift distances are presented in Table 30 below. Spray drift areas range from 121.4  311.7 feet for aerial spray and 13  521 for ground spray.

Table 30. Mammalian spray drift buffer calculations Use Adjusted Application Rate1 Short grass upper bound EEC ( mg/ kg) Short grass 15g mammal adjusted EEC ( mg/ kg) Fraction of applied2 ( adjusted for 15g mammal) Buffer distance ( feet)

Aerial Spray Ground Spray Apples ( 0.25 lb ai/ A, 3 applications, 7d interval) 0.66 lb ai/ A 157.7 150.0 0.04 236.2 23.0 Raspberries ( 0.125 lb ai/ A, 7 applications, 28d interval) 0.29 lb ai/ A 69.0 65.6 0.08 121.4 13.1 Grapes ( 0.1875 lb ai/ A, 3 applications, 14d interval) 0.44 lb ai/ A 105.0 100.0 0.06 160.8 16.4 Page 75 of 241 Golf Course Turf ( 2.7 lb ai/ A, 26 applications, 14d interval) 11.3 lb ai/ A 2703.9 2568.7 0.002 NA 521.7 Golf Course Turf ( 2.7 lb ai/ A, 1 application) 2.7 lb ai/ A 648.0 615.6 0.009 NA 108.3 Residential, Commercial, & Recreational Turf ( 1.36 lb ai/ A, 2 applications, 14d interval) 2.4 lb ai/ A 573.8 545.1 0.01 NA 95.1 Christmas Trees ( 0.25 lb ai/ A, 8 applications, 14d interval) 0.92 lb ai/ A 220.8 209.8 0.03 311.7 29.5 1Adjusted rate is short grass EEC/ 240 to account for the ability of AgDrift to only make calculations based on a single application 2 Fraction of EEC needed to generate an RQ = 1.0 ( LOC); [ EEC of 2.5 mg/ kg]

c. Non Target Insects EFED currently does not calculate risk quotients for terrestrial non target insects. However, and appropriate label statement is required to protect foraging honeybees when the LD 50 is < 11 µ g/ bee. Based on the acute contact toxicity study to honeybees, the LD 50 for triadimefon is > 25 µ g/ bee. This classifies triadimefon as practically non toxic to honeybees.

d. Earthworms Although there are no data on the toxicity of triadimefon or triadimenol to earthworms, an estimation of the concentration of the chemical within earthworms was calculated in order to determine the possible contribution of earthworm ( and other terrestrial invertebrate) consumption to mammal and avian risk. This estimation of earthworm concentration was calculated using a fugacity based ( equilibrium partitioning) approach based on the work of Trapp and McFarlane ( 1995) and Mackay and Paterson ( 1981). Earthworms dwelling within the soil are exposed to contaminants in both soil pore water and via the ingestion of soil ( Belfroid et al. 1994). The concentrations of triadimefon and its degradates in earthworms were calculated as a combination of uptake from soil pore water and gastrointestinal absorption from ingested soil:

C earthworm = [( C soil )( Z earthworm / Z soil )]+[( C soil water )( Z earthworm / Z water )]

where: C soil is the concentration of chemical in bulk soil ( note: a chemical concentration averaged over a 15 cm soil depth was used to reflect a concentration across the earthworm occupied area of soil) Z earthworm is the fugacity capacity of chemical in earthworms = ( lipid)( K ow )( Dearthworm )/ H Page 76 of 241 Z soil is the fugacity capacity of chemical in soil = ( K d )( Dsoil )/ H Z water is the fugacity capacity of chemical in water = 1/ H C soil water is the concentration of chemical in soil water = C soil / K bw K bw is the bulk soil to water partitioning coefficient = ( Dsoil )( K d )+ 2 +(, 2)( K aw ) K aw is the air to water partitioning coefficient = H/ RT H = Henry's Constant specific to triadimefon R = universal gas constant, 8.31 Joules m3/ mol oK T = temperature oK, assumed to be 298 oK K d = soil partitioning coefficient = ( chemical K oc )( 0.02 assumed fraction of soil organic carbon) Dsoil = bulk density of soil, assumed to be 1.3 g/ cm3 2 = volumetric fraction of the soil, assumed to be 0.30 , = volumetric total porosity of the soil, assumed to be 0.50 lipid = fraction of lipid in organism 0.01 ( Cobb et al. 1995) K ow = fipronil or degradate octanol to water partitioning coefficient Dearthworm = the density of the organism g/ cm3, assumed to be 1 g/ cm3 Assuming the maximum application rate of triadimefon of 2.7 lb/ acre ( 3.1 kg/ ha) to a bare, very low density soil ( 1.3 g/ cm3) incorporated to 1 cm depth ( it should be noted that triadimefon is applied without incorporation), the following soil concentrations can be calculated for a depth of 1 cm:

triadimefon soil concentration =

3.1 kg 1x106 mg 1 ha 1 cm3 ha X kg X 1x108 cm2 X 1 cm X 0.0013 kg = 23.8 mg/ kg Based on this soil concentration calculation of 23.8 mg/ kg, the concentration of triadimefon in an earthworm based on the above earthworm fugacity model equation ( using the maximum application rate) would be 0.13 mg/ kg ( for detailed calculations, see Appendix H).

The calculated earthworm tissue concentrations of triadimefon/ triadimenol suggest that ingestion of earthworms by birds and mammals based on dietary dose ( triadimefon NOAEC = 20 mg/ kg diet and NOAEL = 2.5 mg/ kg bw, respectively) could be another exposure pathway contributing to chronic risk, although the low earthworm concentrations would necessitate consumption of a large number of worms.

e. Non target Plants No terrestrial plant toxicity studies were submitted to the Agency by the registrant. In addition, studies obtained through the ECOTOX database did not provide information to quantitatively assess the potential risks associated with triadimefon use to terrestrial non target plants. Information from several studies obtained through ECOTOX suggest potential deleterious effects of triadimefon exposure to both monocot and dicot plants, but this information could not be used Page 77 of 241 quantitatively for the purposes of this assessment. However, this study underscores the need for registrant submitted terrestrial plant toxicity studies, which represent a major data gap.

3. Incident Data Review A review of the Ecological Incident Information System ( EIIS) was completed on April 21, 2005. No incidents involving triadimefon or its metabolite triadimenol were reported.

4. Federally Threatened and Endangered ( Listed) Species of Concern Section 7 of the Endangered Species Act, 16 U. S. C. Section 1536( a)( 2), requires all federal agencies to consult with the National Marine Fisheries Service ( NMFS) for marine and anadromous listed species, or the United States Fish and Wildlife Services ( FWS) for listed wildlife and freshwater organisms, if they are proposing an " action" that may affect listed species or their designated habitat. Each federal agency is required under the Act to insure that any action they authorize, fund, or carry out is not likely to jeopardize the continued existence of a listed species or result in the destruction or adverse modification of designated critical habitat. To jeopardize the continued existence of a listed species means " to engage in an action that reasonably would be expected, directly or indirectly, to reduce appreciably the likelihood of both the survival and recovery of a listed species in the wild by reducing the reproduction, numbers, or distribution of the species." 50 C. F. R. § 402.02.

To facilitate compliance with the requirements of the Endangered Species Act subsection ( a)( 2) the Environmental Protection Agency, Office of Pesticide Programs has established procedures to evaluate whether a proposed registration action may directly or indirectly reduce appreciably the likelihood of both the survival and recovery of a listed species in the wild by reducing the reproduction, numbers, or distribution of any listed species ( U. S. EPA 2004). After the Agency's screening level risk assessment is conducted, if any of the Agency's listed species LOCs are exceeded for either direct or indirect effects, an analysis is conducted to determine if any listed or candidate species may co occur in the area of the proposed pesticide use or areas downstream or downwind that could be contaminated from drift or runoff/ erosion. If determined that listed or candidate species may be present in the proposed action areas, further biological assessment is undertaken. The extent to which listed species may be at risk then determines the need for the development of a more comprehensive consultation package as required by the Endangered Species Act.

The federal action addressed herein is the proposed re registration of pesticide products that contain the active ingredient triadimefon. Triadimefon uses proposed for re registration are identified in Section II. Growing areas for these uses encompasses most of the United States due to its extensive use on turf.

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. Page 78 of 241 a. Action Area For listed species assessment purposes, the action area is considered to be the area affected directly or indirectly by the Federal action and not merely the immediate area involved in the action. This screening level risk assessment considers broadly described taxonomic groups and so conservatively assumes that listed species within those broad groups are co located with the pesticide treatment area. For example, terrestrial plants and wildlife are assumed to be located on or adjacent to the treated site and aquatic organisms are assumed to be located in a surface water body adjacent to the treated site. This assessment also assumes that the listed species are located within an assumed area which has the relatively highest potential exposure to the pesticide, and that exposures are likely to decrease with distance from the treatment area. Section II of this risk assessment presents the triadimefon use sites that are used to establish initial co location of species within treatment areas. Due to the use of triadimefon on turf, it must be assumed that the species co occurrence could occur in most areas of the United States. The Agency does not currently have a method to determine which areas are covered with turf.

b. Taxonomic Groups Potentially at Risk If the assumptions associated with the screening level action area result in RQs that are below the listed species LOCs, a " no effect" determination conclusion is made with respect to listed species in that taxa, and no further refinement of the action area is necessary. Furthermore, RQs below the listed species LOCs for a given taxonomic group indicate no concern for indirect effects on listed species that depend upon the taxonomic group for which the RQ was calculated. However, in situations where the screening assumptions lead to RQs in excess of the listed species LOCs for a given taxonomic group, a potential for a " may affect" conclusion exists and may be associated with direct effects on listed species belonging to that taxonomic group or may extend to indirect effects upon listed species that depend upon that taxonomic group as a resource. In such cases, additional information on the biology of listed species, the locations of these species, and the locations of use sites are considered to determine the extent to which screening assumptions regarding an action area apply to a particular listed organism. These subsequent refinement steps will consider how this information would impact the action area for a particular listed organism and potentially include areas of exposure that are downwind and downstream of the pesticide use site.

Assessment endpoints, exposure pathways, and the conceptual model addressing proposed triadimefon re registration uses, and the associated exposure and effects analyses conducted for the triadimefon screening level risk assessment are in Section III. The assessment endpoints used in the screening level risk assessment include those defined operationally as reduced survival and reproductive impairment for both aquatic and terrestrial animal species and survival, reproduction, and growth of aquatic and terrestrial plant species from both direct acute and direct chronic exposures. These assessment endpoints address the standard set forth in the Endangered Species Act requiring federal agencies to ensure that any action they authorize does not reduce appreciably the likelihood of both the survival and recovery of a listed species in the wild by reducing the reproduction, numbers, or distribution of broad based taxa groups.

Both acute endangered species and chronic risk LOCs are considered in the screening level risk Page 79 of 241 assessment to identify direct and indirect effects to taxa of listed species. This section identifies direct effect concerns, by taxa, triggered by exceeding endangered LOCs in the screening level risk assessment with an evaluation of the potential probability of individual effects for exposures that may occur at the established endangered species LOC. Data on exposure and effects collected under field conditions are evaluated to make determinations on the predictive utility of the direct effect screening assessment findings to listed species. Additionally, the results of a screen for indirect effects to listed species, using direct effect acute and chronic LOCs for each taxonomic group, is presented and evaluated.

i. Listed Species Risk Quotients The Agency's levels of concern for Federally listed freshwater fish, freshwater invertebrates, aquatic non vascular plants, birds, and mammals are exceeded for the use of triadimefon. The preliminary risk assessment for Federally listed species indicates that triadimefon exceeds the endangered species LOCs for the following combinations of analyzed uses, application rates, and species: ° Freshwater fish: Chronic LOC exceedance is for the 2.7 lb ai/ A application of non granular triadimefon to golf course turf, for both the Florida turf ( 26 applications, 14 day intervals) and Pennsylvania turf ( 13 applications, 14 day intervals) scenarios in PRZM EXAMS.

° Freshwater invertebrates: Acute LOCs are exceeded based on the application of non granular triadimefon to golf course turf, for both the Florida turf ( 26 applications, 14 day intervals) and Pennsylvania turf ( 13 applications, 14 day intervals) scenarios in PRZM EXAMS. Chronic LOCs are also exceeded for freshwater invertebrates based on these two golf course scenarios.

° Non vascular aquatic plants: LOCs are exceeded based on the application of nongranular triadimefon to golf course turf, for both the Florida turf ( 26 applications, 14 day intervals) and Pennsylvania turf ( 13 applications, 14 day intervals) scenarios in PRZM EXAMS.

° Birds: Dietary based acute LOCs are exceeded for golf course application ( 26 applications) of non granular triadimefon on all food items. Dietary based chronic LOCs are exceeded for birds that consume short grass, tall grass, broadleaf plants, and small insects for all modeled scenarios and application rates ( 0.125  2.7 lb ai/ A). Additionally, the chronic LOCs are exceeded for birds that consume the aforementioned food items plus fruits, pods, seeds, and small large insects based on all turf applications ( golf course and residential/ commercial).

° Mammals: Listed species dose based acute risk LOCs ( RQ$ 0.1) for direct effects of triadimefon on mammals were exceeded for apples, pears, grapes, golf course turf ( 26 and 1 application), residential/ commercial & recreational turf, and christmas tree applications for several combinations of body size and food item. In addition, for uses of triadimefon on golf course turf ( one application), Page 80 of 241 residential/ commercial & recreational turf, and Christmas trees, there were less exceedances for some food types and larger mammals compared to other uses. Listed species dose based chronic LOCs ( RQ $ 1.0) were exceeded for all triadimefon uses for all mammals that feed on grasses, broadleaf plants, and small insects. There were also exceedances for mammals that consume fruits, pods, and large insects for the apple, grape, turf ( all), and Christmas tree applications. Additionally, there were exceedances for seed consuming mammals for all turf scenarios.

ii. Probit Dose Response Analysis The Agency uses the probit dose response relationship as a tool for providing additional information on the listed animal species acute levels of concern. Acute listed species LOCs of 0.1 and 0.5 are used for terrestrial and aquatic animals, respectively. As part of the risk characterization, an interpretation of acute LOCs for listed species is discussed. This interpretation is presented in terms of the chance of an individual event ( i. e., mortality or immobilization) should exposure at the estimated environmental concentration actually occur for a species with sensitivity to triadimefon or triadimenol on par with the acute toxicity endpoint selected for RQ calculation. To accomplish this interpretation, the Agency uses the slope of the dose response relationship available from the toxicity study used to establish the acute toxicity measures of effect for each taxonomic group. The individual effects probability associated with the LOC is based on the mean estimate of the slope and an assumption of a probit dose response relationship. In addition to the single effects probability estimate based on the mean, upper, and lower estimates of the effects probability are also provided to account for variance in the slope. The upper and lower bounds of the effects probability are based on available information on the 95% confidence interval of the slope. A statement regarding the confidence in the estimated event probabilities is also included. Studies with good probit fit characteristics ( i. e., statistically appropriate for the data set) are associated with a high degree of confidence. Conversely, a low degree of confidence is associated with data from studies that do not statistically support a probit dose response relationship. In addition, confidence in the data set may be reduced by high variance in the slope ( i. e., large 95% confidence intervals), despite good probit fit characteristics.

Individual effect probabilities are calculated based on an Excel spreadsheet tool IECC1.1 ( Individual Effect Chance Model Version 1.1) developed by the USEPA, Office of Pesticide Programs, Environmental Fate and Effects Division ( June 22, 2004). The model allows for such calculations by entering the mean slope estimate ( and the 95% confidence bounds of that estimate) as the slope parameter for the spreadsheet. In addition, the LOC ( 0.1 for terrestrial animals and 0.05 for aquatic animals) is entered as the desired threshold.

Aquatic Listed Species The probability of individual effects at the acute endangered species LOC ( RQ = 0.05 which is equivalent to 1/ 20 of the LC 50 or EC50) for each major listed species taxonomic group and the probability of individual effects at estimated acute RQs above the endangered species acute risk LOC is provided in Table 31. In addition, extrapolation of low probability events such as those occurring at the LOC, are associated with a high degree of uncertainty. To address this Page 81 of 241 uncertainty, analyses of individual effects are also conducted at the upper and lower 95% confidence interval of the probit slope for each taxa. The probit slopes used in this analysis were obtained from dose response relationships used in calculating RQs.

° Freshwater Fish: An event probability was calculated for the listed species LOC for application of non granular triadimefon, based on the probit dose response relationship slope of 4.3 ( 95% CI: 2.8  5.8) obtained from the rainbow trout triadimefon acute toxicity study ( MRID 43256201). The corresponding estimate chance of individual mortality associated with the listed species LOC ( 0.05) of the acute toxic endpoint for freshwater fish is 1 in 9x107. It is recognized that extrapolation of very low probability events is associated with considerable uncertainty in the resulting estimates. In order to explore the possible bounds to such estimates, the upper and lower bounds of the slope estimate ( 95% CI: 2.8  5.8) were used to calculate the upper and lower estimates of the effects probability associated with the listed species LOC. The respective lower and upper effects probability estimates are 1 in 7400 and 1 in 4.4x1013. The uncertainty in estimated event probabilities for this taxonomic group is increased by the large confidence intervals associated with the slope.

° Freshwater Invertebrates: Acute RQ values were derived based on toxicity data from Daphnia magna demonstrating an LC50 of 1.6 ppm ( MRID 231311). An event probability was calculated for the listed species LOC based on the probit dose response relationship slope of 4.3 ( 95% CI = 2.2  6.4). The corresponding estimate chance of individual mortality associated with the listed species LOC ( 0.05) of the acute toxic endpoint for freshwater invertebrates is 1 in 9x107. It is recognized that extrapolation of very low probability events is associated with considerable uncertainty in the resulting estimates. In order to explore the possible bounds to such estimates, the upper and lower bounds of the slope estimate ( 95% CI: 2.2  6.4) were used to calculate the upper and lower estimates of the effects probability associated with the listed species LOC. The respective lower and upper effects probability estimates are 1 in 475 and 1 in 1.0x1016. The uncertainty in estimated event probabilities for this taxonomic group is increased by the large confidence intervals associated with the slope.

Table 31. Probability of Direct Individual Effects to Aquatic Organisms Associated with Triadimefon Use.

Crop Site ( application rate) Fish and Amphibian Probit Slope = 4.3 Invertebrate Probit Slope = 4.3 Agency LOC = 0.05 1 in 9x107 1 in 9x107 FL turf ( golf course) ( 2.7 lb ai/ A, 26 apps, 14d interval)  a RQ = 0.1 1 in 1.17 x 105 PA turf ( golf course) ( 2.7 lb ai/ A, 13 apps, 14d interval)  a RQ  0.08 1 in 8.33 x 105 a = endangered species acute LOC is not exceeded and the probability of an individual effects is less than the value listed for the endangered species LOC. Page 82 of 241 Terrestrial Listed Species The probability of individual effects at the acute endangered species LOC ( RQ = 0.1 which is equivalent to 1/ 10 of the LD 50 ) for each major listed species taxonomic group and the probability of individual effects at estimated acute RQs above the endangered species acute risk LOC is provided in Table 32. In addition, extrapolation of low probability events such as those occurring at the LOC, are associated with a high degree of uncertainty. To address this uncertainty, analyses of individual effects are also conducted at the upper and lower 95% confidence interval of the probit slope for each taxa. The probit slopes used in this analysis were obtained from doseresponse relationships used in calculating RQs.

° Birds: Based on the raw data available from the bobwhite quail subacute dietary toxicity study, the probit method could not be used to examine the dose response relationship because there were less than two test concentrations at which the percent mortality was between zero and 100%. Therefore, the default probit dose response slope of 4.5 was used to calculate the probability of effects on individual birds exposed to triadimefon. The lower and upper confidence limits are assumed to be 2 and 9, respectively. Based on these assumptions, the probability of individual effects is 1 in 294,000. At the lower and upper confidence limits, the probability of individual effects is 1 in 44 and 1 in 1 x 1016, respectively. For birds exposed to triadimefon at the highest registered use rate, the probability of individual effects ranges from 1 in 1,210 to 1 in 11.4.

° Mammals: Based on the raw data available from the rat acute toxicity study demonstrating a male rat triadimenol LD 50 of 689 mg/ kg bw ( MRID 00125411), the data does not fit a probit dose response relationship. Therefore, the default probit doseresponse slope of 4.5 was used to calculate the probability of effects on individual mammals exposed to triadimefon. The lower and upper confidence limits are assumed to be 2 and 9, respectively. Based on these assumptions, the probability of individual effects is 1 in 294,000. At the lower and upper confidence limits, the probability of individual effects is 1 in 44 and 1 in 1 x 1016, respectively. For mammals exposed to triadimefon at the highest registered use rate, the probability of individual effects ranges from 1 in 1210 to 1 in 1.74.

Table 32. Probability of Acute Mortality of an Individual, by Taxa Group and Body Weight, Exposed at the Endangered Species LOC ( 0.1) at the highest registered use rate ( 2.7 lb ai/ A, 26 applications, 14 day interval) for Triadimefon Taxa Body weight ( g) Dietary Food Source LOC = 0.1 2.7 lb ai/ A, 26 apps, 14day interval Probability of effect at LOC ( 1 in _) EEC ( ppm) RQ Probability of effect at RQ ( 1 in _)

Birds ( slope = 4.5) NA short grass 2.94 x 105 2704 0.5 11.4 tall grass 2.94 x 105 1239 0.3 107 Page 83 of 241 broadleaf plants/ small insects 2.94 x 105 1521 0.2 1210 Mammals ( slope = 4.5) 15 short grass 2.94 x 105 2704 1.1 1.74 35 short grass 2.94 x 105 2704 0.9 2.39 1000 short grass 2.94 x 105 2704 0.5 11.4 15 tall grass 2.94 x 105 1239 0.5 11.4 35 tall grass 2.94 x 105 1239 0.4 27.3 1000 tall grass 2.94 x 105 1239 0.2 1210 15 broadleaf plants/ small insects 2.94 x 105 1521 0.6 6.29 35 broadleaf plants/ small insects 2.94 x 105 1521 0.5 11.4 1000 broadleaf plants/ small insects 2.94 x 105 1521 0.3 107 c. Indirect Effects Pesticides have the potential to cause indirect effects to endangered or threatened species by, for example, perturbing forage or prey availability, altering the extent of nesting habitat, etc. The potential for indirect effects is determined by comparing RQs to the LOCs. If the RQ exceeds the LOC, then there is the potential for indirect effects to listed species dependent on those taxa for which the RQ values exceed the LOC.

For aquatic species potentially exposed to triadimefon, RQs exceeded the listed species acute risk LOC for freshwater invertebrates and non vascular aquatic plants. The listed species LOC was only exceeded for freshwater invertebrates and non vascular aquatic plants for triadimefon applications to golf course turf ( FL and PA scenarios).

Based on the aquatic LOC exceedances for triadimefon, indirect effects to listed species would be expected most for species dependent on freshwater invertebrates and freshwater non vascular plants based on the above analysis. Given that both non vascular aquatic plants and freshwater invertebrates are important components of any aquatic ecosystem, indirect effects on a number of aquatic and terrestrial listed species is possible. The most obvious indirect effects would likely relate directly to reductions in food availability or habitat alterations associated with reduced aquatic plant and invertebrate biomass. Other, less obvious indirect effects might include disruptions of listed species life cycles if certain life cycle components are dependent on particular plant or invertebrate species. It is important to note that for most applications of triadimefon, there were no listed species RQ exceedances, and that the FL and PA golf course turf scenarios assume a high number of repeated applications ( 26 and 13, respectively). Page 84 of 241 For terrestrial species, the screening level analysis indicated that, for most uses, triadimefon may cause deleterious effects in exposed bird and mammal populations ( i. e., acute and chronic LOCs are exceeded for birds and mammals). This suggests potential concern for indirect effects on listed organisms dependent upon vertebrate species ( birds, mammals, reptiles, amphibians) as prey items. A potential drop in vertebrate biomass associated with triadimefon use may reduce a significant potion of the prey base. While it is likely that fields can be repopulated by immigrants and living breeders after the use of pesticides, if the prey base is removed at a critical life cycle juncture, over a large area, or if it is removed for a long enough duration, some species may have difficulty meeting energy needs. Also, some species may be particularly sensitive during reproductive or developmental periods. A starting point for evaluating the potential risk of such a scenario would be to first identify listed species likely to occur in triadimefon use areas, compare the life histories of listed species in known use areas, and determine if this use is likely to overlap with a sensitive life cycle component.

Because of the likelihood of direct impacts to birds and mammals under numerous uses of triadimefon, there is also a potential for indirect effects to some listed plant species through effects on pollinators. For example, if avian pollinators are negatively impacted by triadimefon, use during the reproductive period of a particular plant could reduce successful pollination. This particular indirect effect is dependent both on pollinator species affected and on the timing and manner of triadimefon use. A preliminary analysis could include first, identifying plants that could be at risk based on location and timing of pollination. Second, identifying potential pollinators and whether they would be affected by the intended use of triadimefon as not all uses may cause risk to all pollinators.

The information presented on indirect effects serves as a guide to establish the need for and extent of additional analyses that may be performed using Services provided " species profiles" as well as evaluations of the geographical and temporal nature of the exposure to ascertain if a " not likely to adversely affect" determination can be made. The degree to which additional analyses are performed is commensurate with the predicted probability of adverse effects from the comparison of the dose response information with the EECs. The greater the probability that exposures will produce effects on a taxa, the greater the concern for potential indirect effects for listed species dependant upon that taxa, and therefore, the more intensive the analysis on the potential listed species of concern, their locations relative to the use sites, and information regarding the use scenario ( e. g., timing, frequency, and geographical extent of pesticide application).

d. Critical Habitat for Listed Species In the evaluation of pesticide effects on designated critical habitat, consideration is given to the physical and biological features ( constituent elements) of a critical habitat identified by the U. S Fish and Wildlife and National Marine Fisheries Services as essential to the conservation of a listed species and which may require special management considerations or protection. The evaluation of impacts for a screening level pesticide risk assessment focuses on the biological features that are constituent elements and is accomplished using the screening level taxonomic analysis ( risk quotients, RQs) and listed species levels of concern ( LOCs) that are used to evaluate direct and indirect effects to listed organisms. Page 85 of 241 The screening level risk assessment has identified potential concerns for indirect effects on listed species for those organisms dependant upon birds, reptiles, terrestrial phase amphibians, freshwater invertebrates, and non vascular aquatic plants. In light of the potential for indirect effects, the next step for EPA and the Service( s) is to identify which listed species and critical habitat are potentially implicated.

Analytically, the identification of such species and critical habitat can occur in either of two ways. First, the agencies could determine whether the action area overlaps critical habitat or the occupied range of any listed species. If so, EPA would examine whether the pesticide's potential impacts on non endangered species would affect the listed species indirectly or directly affect a constituent element of the critical habitat. Alternatively, the agencies could determine which listed species depend on biological resources, or have constituent elements that fall into the taxa that may be directly or indirectly impacted by the pesticide. Then EPA would determine whether use of the pesticide overlaps the critical habitat or the occupied range of those listed species. EPA and the Service( s) are presently working together to conduct the necessary analysis.

This screening level risk assessment for critical habitat provides a listing of potential biological features that, if they are constituent elements of one or more critical habitats, would be of potential concern. These correspond to the taxa identified above as being of potential concern for indirect effects and include the following birds, reptiles, terrestrial phase amphibians, and freshwater invertebrates. The Agency recognizes that there are no listed non vascular aquatic plant species. This list should serve as an initial step in problem formulation for further assessment of critical habitat impacts outlined above, should additional work be necessary.

Table 33. Tabulation by Taxonomic Group and Crop of Listed Species that Occur in Proposed Triadimefon Re registration Use Areas.

Crop Taxonomic Group Birds Mammals Reptiles Amphibians Fish Crustaceans Arachnids Insects Snails Clams Plants Total Apples 57 56 26 17 108 18 11 44 27 69 498 931 Pears 31 44 22 15 70 11 11 33 12 41 276 566 Raspberries 19 31 8 6 25 9 0 21 2 14 188 323 Grapes 35 46 23 16 75 15 9 37 13 60 318 647 Christmas Trees 33 42 22 15 56 13 11 35 14 59 285 585 Turf 90 78 36 21 114 21 12 44 32 70 746 1264 Total Unique Species 90 78 36 21 114 21 12 44 32 70 746 1264 Total States/ Territories 55 50 23 12 41 13 2 27 16 28 54  Page 86 of 241 Table 34. Tabulation by State/ Territory and Taxonomic Group of Listed Species that Occur in Proposed Triadimefon Re registration Use Areas State Taxonomic Group Birds Mammals Reptiles Amphibians Fish Crustaceans Arachnids Insects Snails Clams Plants Total Alabama 4 4 5 2 15 1 0 0 10 21 17 88 Alaska 3 0 0 0 0 0 0 0 0 0 1 4 Am. Samoa 0 0 2 0 0 0 0 0 0 0 0 2 Arizona 8 8 2 2 16 0 0 0 2 0 18 56 Arkansas 3 3 0 0 3 2 0 1 1 6 4 23 California 16 22 8 6 28 8 0 22 1 0 180 291 Colorado 3 2 0 0 6 0 0 2 0 0 13 26 Connecticut 3 2 0 0 1 0 0 1 0 1 2 10 Delaware 2 2 0 0 1 0 0 0 0 0 3 7 District of Columbia 1 0 0 0 0 1 0 0 0 0 0 2 Florida 10 16 10 0 4 1 0 1 1 7 55 105 Georgia 5 4 2 1 11 0 0 1 0 16 21 61 Guam 6 2 2 0 0 0 0 0 0 0 1 11 Hawaii 32 2 2 0 0 1 0 1 1 0 271 309 Idaho 2 4 0 0 7 0 0 0 6 0 3 22 Illinois 3 2 0 0 1 1 0 2 1 6 8 24 Indiana 3 2 1 0 0 0 0 2 0 10 2 20 Iowa 3 1 0 0 2 0 0 0 1 2 6 15 Kansas 4 2 0 0 4 0 0 1 0 0 2 13 Kentucky 3 3 0 0 5 1 0 0 0 21 10 43 Louisiana 6 2 3 0 2 0 0 0 0 2 2 17 Maine 3 2 0 0 2 0 0 0 0 0 3 10 Maryland 2 3 0 0 2 0 0 2 0 1 6 16 Massachusetts 3 2 1 0 1 0 0 3 0 0 3 13 Michigan 3 2 1 0 0 0 0 3 0 2 7 18 Minnesota 2 1 0 0 1 0 0 0 0 2 4 10 State Taxonomic Group Birds Mammals Reptiles Amphibians Fish Crustaceans Arachnids Insects Snails Clams Plants Total Page 87 of 241 Mississippi 6 1 5 1 3 0 0 0 0 3 2 21 Missouri 3 2 0 0 7 0 0 1 1 5 8 27 Montana 4 3 0 0 4 0 0 0 0 0 2 13 Nebraska 4 1 0 0 2 0 0 0 0 1 3 11 Nevada 2 0 1 0 23 0 0 2 0 0 9 37 New Hampshire 1 1 0 0 0 0 0 1 0 1 2 6 New Jersey 3 2 0 0 1 0 0 0 0 0 5 11 New Mexico 6 5 1 1 12 1 0 0 2 0 13 41 New York 3 2 0 0 1 0 0 1 1 1 6 15 North Carolina 5 6 1 0 4 0 0 1 1 5 28 51 North Dakota 4 0 0 0 1 0 0 0 0 0 1 6 N. Mariana Islands 6 2 1 0 0 0 0 0 0 0 1 10 Ohio 2 1 2 0 1 0 0 1 0 6 4 17 Oklahoma 7 3 0 0 4 0 0 1 0 2 2 19 Oregon 5 1 0 0 24 1 0 2 0 0 13 46 Pennsylvania 2 2 0 0 0 0 0 0 0 2 2 8 Puerto Rico 9 1 8 3 0 0 0 0 0 0 49 70 Rhode Island 1 2 0 0 1 0 0 1 0 0 2 7 South Carolina 4 3 2 1 1 0 0 0 0 1 19 31 South Dakota 4 1 0 0 2 0 0 1 0 0 1 9 Tennessee 3 4 0 0 14 1 1 0 3 29 19 74 Texas 12 5 3 4 9 1 10 8 0 0 27 79 Utah 2 2 1 0 8 0 0 0 0 0 24 37 Vermont 1 1 0 0 0 0 0 0 0 1 2 5 Virgin Islands 3 0 5 0 0 0 0 0 0 0 4 12 Virginia 3 6 1 1 5 2 0 1 1 18 13 51 State Taxonomic Group Birds Mammals Reptiles Amphibians Fish Crustaceans Arachnids Insects Snails Clams Plants Total Page 88 of 241 Washington 5 5 0 0 17 0 0 1 0 0 6 34 West Virginia 1 5 0 1 0 0 0 0 1 5 5 18 Wisconsin 3 1 0 0 0 0 0 2 0 2 6 14 Wyoming 1 4 0 1 2 0 0 0 0 0 2 10 Total Unique Species 90 78 36 21 114 21 12 44 32 70 746 1264 C. Description of Assumptions, Limitations, Uncertainties, Strengths, and Data Gaps 1. Assumptions and Limitations Related to Exposure for All Taxa This screening level risk assessment relies on proposed label statements and the use closure memo for the maximum rates of triadimefon application, the maximum number of applications, and the shortest interval between applications. The frequency at which actual uses approach these levels is dependent on agricultural conditions and market forces. Moreover, conditions may change on a yearly basis, affecting disease rates and therefore application rates and frequency.

2. Assumptions and Limitations Related to Exposure for Aquatic Species ° This assessment attempts to examine potential aquatic exposure to both triadimefon and its major degradate, triadimenol. The principle triadimefon toxic degradate of concern, triadimenol, primarily forms within soil as a result of microbial activity. Lab soil column studies indicate that little or no parent triadimefon is found in leachate; field studies typically do not detect triadimefon below depths of 12  24 inches ( depending on soil type). Therefore, triadimefon is unlikely to be a major concern for groundwater contamination unless groundwater is very shallow. In addition, triadimefon is less stable in anaerobic ( soil and water) conditions than in aerobic conditions. However, the degradate triadimenol is more likely to be of concern for groundwater contamination because of its greater propensity for leaching ( typically detected at depths 2x greater than the parent) and longer persistence in anaerobic conditions; triadimenol appears stable under anaerobic soil conditions. Thus, a likely sequence of events is that triadimefon degrades to triadimenol mostly in the shallow ( aerobic) subsurface, where it can then be leached deeper into the soil, eventually reaching the groundwater and anoxic/ suboxic conditions. In this environment triadimenol may persist indefinitely, eventually being discharged as baseflow. Triadimenol is of less concern for runoff, as it forms within the soil some time after application. Conversely, parent triadimefon is more likely to be transported via surface runoff, as it has moderately low solubility and is usually applied in spray or granular form at or above the surface; the field dissipation half life of 417 days allows a Page 89 of 241 relatively long period of time during which the compound may be transported off site either dissolved in runoff water or sorbed onto soil particles eroded from the application area.

° There are some uncertainties associated with the use of the PRZM/ EXAMS standard runoff scenario. Major uncertainties associated with the standard runoff scenario include the physical construct of the watershed and representation of vulnerable aquatic environments for different geographic regions. The physicochemical properties ( pH, redox conditions, etc.) of the standard farm pond are based on a Georgia farm pond. These properties are likely to be regionally specific because of local hydrogeological conditions. Any alteration in water quality parameters may impact the environmental behavior of a pesticide. The farm pond represents a well mixed, static water body. Because the farm pond is a static water body ( no flow through), it does not account for pesticide removal through flow through or water releases. The lack of flow through the farm pond provides an environmental condition for accumulation of persistent pesticides. The assumption of uniform mixing does not account for stratification due to thermoclines ( e. g., seasonal stratification in deep water bodies). Additionally, the dimensions of the standard runoff scenario assumes a watershed area to water body volume ratio of 10 ha: 20,000m3. This ratio is recommended to maintain a sustainable constructed pond in the Southeastern United States. The use of higher watershed area to water body volume ratios ( as recommended for sustainable ponds in drier regions of the United States) may lead to higher pesticide concentrations when compared to the standard watershed area to water body volume ratio.

The standard runoff scenario assumes uniform soils and agronomic management practices across the standard 10 hectare field. Soils can vary substantially across even small areas; this variation is not reflected in the model simulations. Additionally, the impact of unique soil characteristics and soil management practices ( e. g., tile drainage) are not considered in the standard runoff scenario. The assumption of uniform site and management conditions is not expected to represent some site specific conditions. Extrapolating the risk conclusions from the standard pond scenario to other aquatic habitats ( e. g., marshes, streams, creeks, and shallow rivers, intermittent aquatic areas) may either underestimate or overestimate the potential risks in those habitats.

° The Oregon berry scenario is intended to be used as a surrogate for raspberries that are grown in California only. EFED does not have a PRZM EXAMS scenario for raspberries grown in California; however, Oregon is probably the best surrogate scenario for Northern California because of similarities in weather conditions and soil types. It is expected that EECs from Oregon and Northern California would be comparable.

° For the golf course turf applications ( FL turf and PA turf scenarios), the label does not specify the specific maximum number of applications that can be made per year. In the case of Florida turf, a year round golf course season was assumed due to the climate. Based on current label specifications that indicate a 14 day application interval, it was assumed that up to 26 applications at the maximum rate could be made per year to a Florida golf course. This high number of applications may overestimate risk. Therefore, EFED also calculated aquatic Page 90 of 241 EEC values assuming a single application at the maximum application rate. For the Pennsylvania turf scenario, a shorter golf course " growing" season was assumed, and EEC values were calculated based on 13 applications at the maximum rate. As with the Florida scenario, EFED also calculated aquatic EEC values assuming a single application at the maximum application rate. These two calculations for each scenario represent the upper and lower bounds of the aquatic EECs for triadimefon application to golf course turf.

° The Florida and Pennsylvania turf PRZM EXAMS scenarios may underestimate aquatic EEC values for triadimefon golf course turf use. The standard PRZM EXAMS turf scenarios are not specific to golf courses. Golf courses are commonly built near water, and many are near wetland areas. Golf courses are typically designed to drain water, and they incorporate mixed areas with depressions, higher slopes, and tile drainage systems. The drainage systems rapidly transport water that can infiltrate to discharge points in nearby surface water bodies.

° The label does not specify different application rates for particular golf course playing areas ( e. g., greens, tees, rough, fairways). Due to the lack of label language, no golf course adjustment factors were applied to the EEC calculations. Therefore, it was assumed that triadimefon could be applied to the entire golf course area at the maximum application rate.

3. Assumptions and Limitations Related to Exposure for Terrestrial Species a. Location of wildlife species In screening terrestrial risk assessments for listed species, a generic bird or mammal is assumed to occupy either the treated field or adjacent areas receiving pesticide at a rate similar to the treatment rate on the field. This assumption leads to an overestimation of exposure to species that do not occupy the treated field. For screening level risk assessment purposes, the actual habitat requirements of any particular terrestrial species are not considered, and it is assumed that species occupy, exclusively and permanently, the treated area being modeled. This assumption leads to an overestimation of exposure in the risk estimates of a proportion of individuals of the exposed population. Although this estimate represents higher levels of exposure, it is within the range of possibility as some species may occupy habitats near the use site and use it to forage. Gorging can be a common opportunistic behavior in some animals whereby food items are consumed in excess of daily requirements due to availability. This example is more likely to support an acute exposure scenario. Chronic exposure is more difficult to ascertain since it occurs over a longer duration, thereby providing more opportunity for animals to move and seek forage elsewhere. Nontheless, many animals do forage over a range that would be included in triadimefon application areas; all prey items for these species may come from use areas.

b. Routes of exposure Screening level risk assessments for applications of pesticides consider dietary exposure alone. Other routes of exposure, not considered in this assessment, are discussed below. Page 91 of 241 i. Incidental soil ingestion This risk assessment does not consider incidental soil ingestion. Available data suggests that up to 15% of the diet can consist of incidentally ingested soil, depending on the species and feeding strategy ( Beyer et al., 1994). In the case of triadimefon, its major degradate, triadimenol, is formed mainly through aerobic microbial degradation in the soil subsurface. This degradate is also toxic to terrestrial species, and therefore current estimates of exposure that only examine exposure to the parent triadimefon may underestimate risk. A simple first approximation of soil concentration of a pesticide resulting from spray application shows the effect of not considering soil ingestion:

Assuming the maximum application rate of non granular triadimefon of 2.7 lb ai/ A ( 3.1 kg/ ha) to a bare, very low density soil ( 1.3 g/ cm3) incorporated to a 1 cm depth ( actual incorporation depths may vary), the following soil concentrations can be calculated for a depth of 1 cm:

soil concentration = ((( 3.1 kg/ ha)( 1 x 106 mg/ kg)) / ( 1.3 x 108 cm3/ ha)))( 1cm3/ 0.001kg) = 31 mg/ kg Including this concentration into the standard screening level method and assumptions for food item pesticide residues ( e. g., 2703 mg/ kg residue assumption for short grass) shows that ingestion of soil at an incidental rate of up to 15% of the diet would not significantly increase dietary exposure. For example, a 20g bird consumes approximately 22.8g of food daily. The amount of triadimefon ingested as a result of feeding on short grass is approximately 61 mg ( 22.8g food consumed x 2703 mg/ kg in food). The amount of triadimefon/ triadimenol ingested as a result of incidental soil ingestion is approximately 0.1 mg ( 15% x 22.8g x 31 mg/ kg), which represents 0.2% of the total exposure due to eating triadimefon/ triadimenol contaminated food items.

ii. Ingestion of plant food items The current model used by EFED to estimate ingestion of pesticide contaminated food items uses the Kenaga nomogram to calculate foliar residue value EECs resulting from application. This method examines residue levels only and does not take into account ingestion of pesticide residues and/ or degradates that are taken up by the plant from the soil ( e. g., the pesticide inside the plant itself). Triadimenol, the major triadimefon degradate, is formed through both microbial degradation in the soil and within the plant once it is systemically absorbed. Therefore, the terrestrial organism exposure to triadimefon and triadimenol may be underestimated.

iii. Inhalation exposure This screening level risk assessment does not consider inhalation exposure. Such exposure may occur through three potential sources: ( 1) spray material in the form of droplets at the time of application, ( 2) vapor phase pesticide volatilizing from treated surfaces, and ( 3) airborne particulate ( soil, vegetative material, and pesticide dusts).

Available data suggest that inhalation exposure at the time of application is not an appreciable route of exposure for birds. According to research on mallard ducks and bobwhite quail, respirable particle size in birds ( e. g., particles reaching the lungs) is limited to a maximum diameter of 2 to 5 micros ( EPA, 1990). The spray droplet spectra covering the majority of Page 92 of 241 pesticide application situations ( AgDrift model scenarios for very fine to coarse droplet sizes) suggests that less than 1% of the applied material is within the respirable particle size. However, the particles may still be ingested, and the model does not address this concern.

Theoretically, inhalation of a pesticide active ingredient in the vapor phase may be another source of exposure for some pesticides under certain exposure situations. Considering the low vapor pressure of triadimefon, it is unlikely that it will exist in the gaseous phase at any considerable amount to cause adverse effects via inhalation.

The impact from exposure to dusts contaminated with the pesticide cannot be assessed generically as partitioning issues related to application site soils and chemical properties render the exposure potential from this route highly situation specific.

iv. Dermal exposure The screening level assessment does not consider dermal exposure, except as it is indirectly included in calculations of RQs based on lethal doses per unit of pesticide treated area ( for granular applications). Dermal exposure may occur through three potential sources: ( 1) direct application of spray to terrestrial wildlife in the treated area or within the drift footprint, ( 2) incidental contact with contaminated vegetation, or ( 3) contact with contaminated water or soil.

The available measured data related to wildlife dermal contact with pesticides are extremely limited. The Agency is actively pursuing modeling techniques to account for dermal exposure via direct application of spray and by incidental contact with vegetation.

c. Foliar Dissipation Half life Due to the lack of available foliar disspiation half life studies, a default value of 35 days was used as an input into T REX to calculate foliar residue levels for terrestrial exposure. It is therefore possible that terrestrial exposure via food item residues could be overestimated. However, chronic LOC exceedances for birds and mammals still occur when the foliar dissipation half life is set to one day. Therefore, although the EEC values may be overestimated by using a foliar dissipation half life of 35 days, the overall potential risk to terrestrial species is not altered by using a lower value.

d. Incidental Pesticide Releases Associated with Use This risk assessment is based on the assumption that the entire treatment area is subject to triadimefon application at the rates specified on the label. In reality, there is the potential for uneven application of triadimefon through such plausible incidents as changes in calibration of application equipment, spillage, and localized releases at specific areas of the treated field that are associated with specifics of the type of application equipment used.

e. Residue Levels Selection As discussed earlier in the exposure section of this document, the Agency relies on the work of Kenaga and Fletcher et al ( 1994) for setting the assumed pesticide residues in wildlife dietary food items. The Agency believes that these residue assumptions reflect a realistic upper bound residue Page 93 of 241 estimate, although the degree to which this assumption reflects a specific percentile estimate is difficult to quantify. It is important to note that the field measurement efforts used to develop the Fletcher estimates of exposure involve highly varied sampling techniques. It is entirely possible that much of these data reflect residues averaged over entirely above ground plants in the case of grass and forage sampling. Depending upon a specific wildlife species' foraging habits, whole above ground plant samples may either underestimate or overestimate actual exposure.

f. Dietary Intake  Differences Between Laboratory and Field Conditions The acute and chronic characterization of risk rely on comparisons of wildlife dietary residues with LC 50 or NOAEC values expressed in concentrations of pesticide in laboratory feed. These comparisons assume that ingestion of food items in the field occurs at rates similar to those in the laboratory. Although the screening level assessment process adjusts dry weight estimates of food intake to reflect the increased mass in fresh weight wildlife food intake estimates, it does not allow for gross energy and assimilative efficiency differences between wildlife food items and laboratory feed.

On gross energy content alone, direct comparison of a laboratory dietary concentration based effects threshold to that of a fresh weight pesticide residue estimate would result in an underestimation of field exposure by a food consumption factor of 1.25  2.5 for most food items. Only for seeds would the direct comparison of dietary threshold to residue estimate lead to an overestimation of exposure.

Differences in assimilative efficiency between laboratory and wild diets suggest that current screening assessment methods do not account for a potentially important aspect of food requirements. Depending upon species and dietary matrix, bird assimilation of wild diet energy ranges from 23  80%, and mammal assimilation of diet ranges from 41  85% ( USEPA, 1993). If it is assumed that laboratory chow is formulated to maximize assimilative efficiency ( e. g., a value of 85%), the potential for underestimation of exposure may exist by assuming that consuption of food in the wild is comparable with consumption during laboratory testing. In the screening level process, exposure may be underestimated because metabolic rates are not related to food consumption.

Finally, the screening procedure does not account for situations where the feeding rate may be above or below requirements to meet free living metabolic requirements. Gorging behavior is a possibility under some specific wildlife scenarios ( e. g., bird migration) where the food intake rate may be greatly increased. Kirkwood ( 1983) has suggested that an upper bound limit to this behavior might be the typical intake rate multiplied by a factor of 5.

In contrast, there is the potential for avoidance, operationally defined as animals responding to the presence of noxious chemicals in their food by reducing consumption of treated dietary elements. This response is seen in nature where herbivores avoid plant secondary compounds. However, reduced food intake, particularly over an extended period, could result in reduced survival or Page 94 of 241 reproductive output.

g. Exposure to Triadimefon Degradates The current assessment does not quantitatively evaluate the exposure to terrestrial organisms that may occur to the triadimefon degradates, triadimenol and triazole. Triadimenol has approximately equal toxicity to mammalian species as the parent triadimefon, and is slightly less toxic to avian species. Exposure to triadimenol is beyond the scope of this assessment. It is formed within plant tissues following uptake, as well as in the soil subsurface. The Agency's current methods of assessing terrestrial exposure deal with foliar residue levels, and do not account ( see above) for these alternate exposure pathways. It is necessary to consider total terrestrial organism exposure would include parent and degradate, and that current estimations of risk based solely on parent triadimefon could therefore be underestimated. 1,2,4 triazole is not addressed in this risk assessment and will be examined in a future separate risk assessment by the Agency.

4. Assumptions and Limitations Related to Effects Assessment a. Age Class and Sensitivity of Effects Thresholds It is generally recognized that test organism age may have a significant impact on the observed sensitivity to a toxicant. The screening risk assessment acute toxicity data for fish are collected on juvenile fish between 0.1 and 5 grams. Aquatic invertebrate acute testing is performed on recommended immature age classes ( e. g., first instar for daphnids, second instar for amphipods, stoneflies and mayflies, and third instar for midges). Similarly, acute dietary testing with birds is also performed on juveniles, with mallard being 5 10 days old and quail 10 14 days old. The screening risk assessment has no current provisions for a generally applied method that accounts for uncertainty associated with study organism age. In so far as the available toxicity data may provide ranges of sensitivity information with respect to age class, the risk assessment uses the most sensitive life stage information as the screening endpoint.

b. Lack of Effects Data for Amphibians and Reptiles Currently, toxicity studies on amphibians and reptiles are not required for pesticide registration. Since these data are lacking, the Agency uses fish as surrogates for aquatic phase amphibians and birds as surrogates for terrestrial phase amphibians and reptiles. These surrogates are thought to be reflective of or protective of ( more sensitive) herpetofauna. Amphibians are characterized by a permeable skin. The most important route of exposure for aquatic amphibians would likely be the dermal route. Using freshwater fish may be suitable surrogates since exposure would likely be surface area dependent and the gill surface of many fish is a fairly large surface area. Also, both fish and amphibians are ectothermic so metabolic rates and demands would likely be similar. For terrestrial species, however, the difference between amphibians and birds and reptiles and birds is quite large. Terrestrial amphibians and reptiles are both ectothermic while birds are endothermic; birds have a higher basal metabolic rate to required to maintain constant body temperature. The higher metabolic demands of birds may be predispose birds to higher relative exposures. However, this does not address any potential differences in toxicity. To date, there are few controlled studies on reptile species that could be used to compare to similar studies on birds. A priori, there is no strong reason to think that one taxa is more or less sensitive than another. Further research is required to determine whether, in general, reptiles and terrestrial phase Page 95 of 241 amphibians are suitably represented by birds species in assessing risks.

c. Use of the Most Sensitive Species Tested Although the screening risk assessment relies on a selected toxicity endpoint from the most sensitive species tested, it does not necessarily mean that the selected toxicity endpoints reflect sensitivity of the most sensitive species existing in a given environment. The relative position of the most sensitive species tested in the distribution of all possible species is a function of the overall variability among species to a particular chemical. The relationship between the sensitivity of the most tested species versus wild species ( including listed species) is unknown and a source of significant uncertainty. The use of laboratory species has historically been driven by availability and ease of maintenance. A widespread comparison of species is lacking, however, even variation within a species can be quite high.

d. Data Gaps The major data gap is the lack of terrestrial and aquatic vascular plant toxicity studies. For triadimefon, the only registrant submitted plant study was on green algae ( Selenastrum capricornutum). Results from this study indicate that triadimefon is toxic to green alga ( Selenastrum capricornutum), however, there is insufficient data to generate a suitable understanding of the toxicity of triadimefon to aquatic plants. There are no registrant submitted data for the effects of triadimefon on terrestrial plants, and none of the plant toxicity studies obtained through the ECOTOX database were suitable to quantitatively assess risk, although one of the studies suggests potential negative effects of triadimefon exposure on both monocot and dicot terrestrial plants. However, it is impossible to quantitatively assess risks to terrestrial plants from the use of triadimefon. This is particularly important in assessing risks to federally listed species. The lack of toxicity data on aquatic and terrestrial plants represents a serious data gap in the toxicity profile of triadimefon. Given the importance of plants to ecosystem function and to the sustainability of numerous animal communities and populations of listed species, a complete dataset on the toxicity of triadimefon to plants is required.

Another important data gap is the lack of acute and chronic toxicity studies on estuarine/ marine fish and invertebrates. Risk estimates for freshwater fish and invertebrates indicate a low potential for risks, even at the highest use rates of triadimefon. This result may suggest a low potential for risk to estuarine/ marine species as well; however, in order to generate robust estimates of risk for estuarine/ marine fish and invertebrates, toxicity studies on representative species from these taxa are required.

5. Assumptions Associated with the Acute LOCs The risk characterization section of the assessment document includes an evaluation of the potential for individual effects to listed species at an exposure level equivalent to the LOC. This evaluation is based on the median lethal dose estimate and dose/ response relationship established for the effects study corresponding to each taxonomic group for which the LOCs are exceeded. The slope of the probit dose response is used to generate a probability of individual effects near the low end tail of the curve. Predictions based on low probability events are by nature highly uncertain. Moreover, for this assessment the dose response curve representing a given taxa is Page 96 of 241 generated from one study using one species. It is likely that the resulting dose response relationship does not represent the response of all species within a taxa. Calculating the probability of individual effects at the lower and upper bounds of the slope is designed to address this source of uncertainty but the extent to which this captures the variability within a taxa is unknown. In some cases, a probit dose response relationship cannot be calculated, as was the case with mammals in this assessment ( data was unavailable). Here, event probabilities for mammalian species were calculated based on a default slope assumption of 4.5 with upper and lower confidence intervals of 2 and 9 ( Urban and Cook, 1986). Given the large uncertainty associated with the probability estimates, it is not possible to accurately predict the chance of an individual mortality event for listed mammalian species. Page 97 of 241 LITERATURE CITED Belfroid, A., M. Sikkenk, W. Seinen, K. V. Gestel, J. Hermens. 1994. The toxicokinetic behavior of chlorobenzenes in earthworm ( Eisenia andrei) experiments in soil. Environ. Toxicol. Chem. 13: 93 99 Beyer, W. N., E. E. Connor, and S. Gerould. 1994. Estimates of soil ingestion by wildlife. J. Wildl. Manage. 58( 2): 375 382.

Cobb, G. P., E. H. Hol, P. W. Allen, J. A Gagne, R. J. Kendall. 1995. Uptake, metabolism, and toxicity of terbufos in the earthworm ( Lumbricus terrestris) exposed to COUNTER 15G in artificial soils. Environ. Toxicol. Chem. 14( 2): 279 285.

Felthousen, R. 1977. Classification of Granulated Formulations. USEPA, September 9, 1977 Fletcher, J. S., J. E. Nellessen, and T. G. Pfleeger. 1994. Literature review and evaluation of the EPA foodchain ( Kenaga) nomogram, and instrument for estimating pesticide residues on plants. Environmental Toxicology and Chemistry 13 ( 9): 1383 1391.

Hoerger, F., and E. E. Kenaga. 1972. Pesticide residues on plants: Correlation of representative data as a basis for estimation of their magnitude in the environment. In F. Coulston and F. Korte, eds., Environmental Quality and Safety: Chemistry, Toxicology, and Technology, Georg Thieme Publ, Stuttgart, West Germany, pp. 9 28.

Kirkwood, J. H. 1983. A limit to metabolizable energy intake in mammals and birds. Comp. Biochem. Physiol. 75A: 1 3.

Mackay, D. and S. Paterson. 1981. Calculating fugacity. Environ. Sci. Technol. 15: 1006 1014.

Trapp, S. And J. C McFarlane ( eds.). 1995. Plant Contamination Modeling and Simulation of Organic Chemical Processes. Lewis Publishers. Boca Raton, Florida.

Urban D. J. and N. J. Cook. 1986. Hazard Evaluation Division Standard Evaluation Procedure Ecological Risk Assessment. EPA 540/ 9 85 001. U. S. Environmental Protection Agency, Office of Pesticide Programs, Washington, DC.

U. S. EPA. 2004. Overview of the Ecological Risk Assessment Process in the Office of Pesticide Programs. Office of Prevention, Pesticides and Toxic Substances. Office of Pesticides Programs. Washington, DC. January 23, 2004.

U. S. EPA. 1993. Wildlife Exposure Factors Handbook. EPA/ 600/ R 13/ 187a, Office of Research and Development, Washington, D. C.

U. S. EPA. 1990. Laboratory Test Methods of Exposure to Microbial Pest Control Agents by the Respiratory Route to Nontarget Avian Species. Environmental Research Laboratory, Corvalis, OR. EPA/ 600/ 3 90/ 070. Page 98 of 241 Willis, G. H., and L. L. McDowell. 1987. Pesticide Persistence on Foliage in Reviews of Environmental Contamination and Toxicology. 100: 23 73. Page 99 of 241 APPENDIX A. Environmental Fate Studies FATE STUDIES FOR TRIADIMEFON: SUMMARIES AND REVIEWS Solubility Somewhat soluble (~ 70ppm  RED # D27523), Triadimefon is capable of being transported dissolved in water ( as surface runoff or as leachate to groundwater). Most applications are already in liquid form: as aerial spray, ground spray, pestigation, or broadcast. Granular applications are also allowed for turf treatments. In all these cases there is the potential for transport into groundwater ( via leaching through soil) and surface water ( in 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 ( height of column used in experiment) in sandy loam and clay loam. 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 ( total 5.44 lb a. i./ A). Triadimenol ( the most common degradate found in most studies) appears to be even more prone to leaching; it was detected at depths up to 48 inches. This may partly be due to it's formation in the ( aerobic) subsurface, where subsequent rain or irrigation events can leach it deeper into the soil. None of these studies, which evaluate constituents in soil porewater, measure or account for the likelihood of preferential flow ( e. g., macropores) and potentially efficient delivery to the saturated zone ( and thus into groundwater). Once within the saturated zone, there is little possibility of degradation because of the physico chemical properties of the compound ( see below).

Vapor Pressure / Henry's Law Constant Triadimefon has moderate to low volatility ( vapor pressure = 7.6E 7 mm Hg, Henry' law const. = 1.15E 7 atm m3/ mol; CAS # 43121433), and is less volatile than water. In any event, airborne triadimefon is not likely to be a major source of contamination, whether from spray drift, volatilization, or other mechanisms. Estimated half life of airborne triadimefon is ~ 14 hours, primarily by photochemical degradation ( CAS # 43121433). Wet or dry deposition onto surfaces ( e. g., vegetation) will be subject to degradation, mostly by photolysis.

Hydrolysis Triadimefon is stable to hydrolysis in acidic ( pH 4), neutral, and basic ( pH 9) environments ( MRID # 41922101).

Aqueous Photolysis Triadimefon should degrade fairly rapidly in water exposed to direct sunlight ( half life = 7.6 hours  MRID # 42112901 & 41933601).

Soil Photolysis Triadimefon is somewhat more stable to photolysis on soil, with a half life of 30 days ( MRID # 42820401). Page 100 of 241 Aerobic Soil Metabolism Triadimefon appears to undergo slow degradation in aerobic soil, with a field measured half life of 417 days ( MRID # 42242701). However, lab studies yielded a much shorter half life of 5.6 days ( MRID # 42224104 & 41686102). 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. 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. The half life for total residues ( triadimefon + triadimenol) is 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)

Anaerobic Soil Metabolism Triadimefon may be somewhat less stable in anaerobic soils ( half life = 23.1 days, MRID # 41686101). However, anaerobic aquatic studies ( see below), which supersede anaerobic soil studies, indicate a much longer half life, albeit still shorter than under aerobic conditions.

Aerobic Aquatic Metabolism Triadimefon is very stable in aerobic aquatic environments, with a half life for total residues of concern ( triadimefon + triadimenol) of 480 days ( MRID # 42224104), which, in the absence of data, was derived by multiplying the aerobic soil value by a factor of two. Thus, triademifon residues are expected to remain for long periods in surface waters ( e. g., streams and lakes) and in oxic unconfined aquifers ( notably, shallow groundwater).

Anaerobic Aquatic Metabolism Triadimefon appears to be less stable in anaerobic aquatic conditions than in aerobic conditions. Nevertheless, the half life of 217 days ( MRID # 42401201) still allows for some accumulation over time with repeated applications.

Field Dissipation Triadimefon dissipated slowly in the field ( aerobic soil conditions), with a half life of 417 days ( MRID # 42242701). Although lab studies indicate an aerobic soil half life of 5.6 days, this is almost certainly an underestimation. 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. If the aerobic soil halflife were truly 5.6 days, triadimefon would not be detected in field studies at the concentrations noted.

Adsorption ( Koc) Triadimefon is considered moderately mobile, with a Koc of 387 L/ kgoc ( MRID # 41616008). Combined with it's solubility and degradation characteristics, triadimefon presents a significant potential for long term contamination of both surface and ground water. In addition, shallow soil depths (< 30 cm) are also likely at risk. Page 101 of 241 Triadimefon would appear to be capable of persisting and accumulating in a variety of environmental conditions. Moderate mobility and adsorption characteristics can allow it to leach to shallow soil depths, where it may persist for long periods under aerobic soil conditions typical of the vadose zone. Repeated annual treatments ( in some cases twice yearly, or more) 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 ( which may be used as drinking water sources in rural areas). Likewise, surface water bodies ( rivers, ponds, and other sources that often serve as drinking water supplies, and that provide habitat for many endangered species) can receive loads from surface runoff ( as this chemical is often applied onto the land surface) as well as from groundwater contributions during baseflow. Contamination via atmosphere is much less likely. Page 102 of 241 FATE STUDIES FOR TRIADIMENOL: SUMMARIES AND REVIEWS Solubility 64 ( Bayleton, http:// www. cdms. net/ ldat/ mp239005. pdf)

Vapor Pressure / Henry's Law Constant ? [ N/ A  subsurface]

Hydrolysis Stable ( EFGWB # 295,296)

Aqueous Photolysis 1.5 days ( EFGWB # 295,296)

Soil Photolysis Stable ( EFGWB # 295,296)

Aerobic Soil Metabolism 744 days [ 248 days ( MRID # 41686102 & 42224104) * 3]

Anaerobic Soil Metabolism Stable ( MRID # 41686101, 42401201)

Aerobic Aquatic Metabolism 1488 days ( 2x aerobic soil)

Anaerobic Aquatic Metabolism Stable Adsorption ( Koc) 365 ( MRID # 41616008  averaged from 4 soils)

Kd 3.5 ( average)

Considering the overall similarities in chemical characteristics to Triadimefon, it might be expected that triadimenol would behave in a similar fashion, especially as regards 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, there is great potential for this compound to persist and accumulate. Thus, groundwater should be most vulnerable. Page 103 of 241 OVERVIEW OF GUIDELINE STUDIES MRID # 423566 01 Column Leaching Study ( satisfies EPA FIFRA Guideline 163 1):

Sandy loam soil was incubated for 30 days with the equivalent of 5.44 lb. a. i./ A ( highest single application rate) of 14C triadimefon under aerobic conditions. Samples of this aged soil were applied to the tops of soil columns containing either sandy loam ( 1.0% organic matter), sand ( 3.7% organic matter), silt loam ( 2.9% organic matter), or clay loam ( 2.2% organic matter). Columns were then leached with the equivalent of 20 inches of rainfall delivered over a 1 2 day period. Less than 12% of triadimefon residues leached through the 45cm soil columns. Most of the residues ( 37.5 60%) remained within the top 6cm. Average amount found in leachate was < 3%. In the columns of sandy loam and clay loam, triadimefon and the degradate triadimenol were found throughout the columns and in the leachate. The greatest mobility was observed in the clay loam column, and the least in the sand column. The study author ascribes this result to differences in organic matter content among the columns.

MRID # 416160 08 Adsorption Desorption Study ( satisfies EPA FIFRA Guideline 163 1):

Adsorption and desorption values were evaluated using 4 soils. These soil types and corresponding organic carbon ( OC) percentages were: Sand ( 0.53% OC), Sandy loam ( 0.58% OC), Silt loam ( 1.5% OC), and Clay loam ( 1.2% OC). K oc values were 224 for the Clay loam, 320 for Sandy loam, 454 for Silt loam, and 460 for Sand. The average K oc value was 365.

MRID # 416861 02 Aerobic Soil Metabolism Study ( satisfies EPA FIFRA Guideline 162 1):

Triadimefon degraded with a half life of 5.6 days in sandy loam soil that was incubated aerobically in darkness at 25oC and 75% of 0.33 bar moisture. Approximately 75% of triadimefon in soil had converted to the degradate triadimenol within 60 days under aerobic conditions. After 180 days, this had dropped to < 60% triadimenol. Specifically, after 60 days in aerobic soil there was detected: 7.3% remained of total parent triadimefon added at beginning of experiment 76.8% had converted to triadimenol At 183 days: 4.6% of triadimefon remained 50.2% was triadimenol 19.5% had become triazole  most of the triazole ( except 1.5% of parent) formed within the last 90 days of the experiment and was tightly bound to soil particles; since formation occurred in the subsurface and triazole forms from triadimenol, it is unlikely that surface dwelling land animal would come into much contact via this degradation pathway. Page 104 of 241 MRID # 422241 04 Aerobic Soil Metabolism Study ( satisfies EPA FIFRA Guideline 162 1):

Revised version of MRID 416861 02, with additional data ( extended from 183 days to 364 days) reported. After 364 days: 8.1% of initial application consisted of triadimefon 32.4% of initial application consisted of triadimenol 30.7% of initial application consisted of triazole.

MRID # 419221 01 Hydrolysis Study ( satisfies EPA FIFRA Guideline 161 1):

Triadimefon was essentially stable (< 3 % degradation) in sterile, aqueous solutions that were buffered ( pH's 5, 7, and 9) and incubated in darkness at 25oC for 30 days.

MRID # 42112901 & 41933601 Aqueous Photolysis Study ( satisfies EPA FIFRA Guideline 161 2):

Triadimefon degraded with a half life of 7.6 hours in sterile non buffered water that was continuously irradiated using a xenon lamp, at approximately 25oC. Triadimefon did not degrade in the dark control. Six degradates were isolated; however, only p chlorophenol was conclusively identified.

MRID # 428204 01 Soil Photolysis Study ( satisfies EPA FIFRA Guideline 161 3):

Triadimefon degraded with a half life of 30 days ( 720 hours of irradiation) on sandy loam soil that was continuously irradiated for 15 days using a UV filtered xenon light source at 22 43oC. The only significant degradate in the irradiated soil was p chlorophenol.

MRID # 416861 01 Anaerobic Soil Metabolism Study ( satisfies EPA FIFRA Guideline 162 2):

Triadimefon degraded with a half life of 23.1 days in sandy loam soil that was incubated under anaerobic conditions ( nitrogen atmosphere) in darkness at 25oC and 75% of 0.33 bar moisture. The major degradate identified was triadimenol. Page 105 of 241 MRID # 416861 01 Anaerobic Aquatic Metabolism Study ( satisfies EPA FIFRA Guideline 162 3):