Document ID: EPA-HQ-OPP-2013-0504-0007
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2014-09-03T04:00Z

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON D.C., 20460
                                   OFFICE OF
                              CHEMICAL SAFETY AND
                             POLLUTION PREVENTION
                                   OFFICE OF
                              CHEMICAL SAFETY AND
                             POLLUTION PREVENTION

                                                                PC Code: 129112
                                                      Chemical: Trifloxystrobin
                                                         	DP Barcode: D413110		

	August 18, 2014
													
MEMORANDUM

SUBJECT:	Ecological Risk Assessment for New Uses of Trifloxystrobin on Chickpeas, Dry Peas, and Lentils 

TO:	Tony Kish, Product Manager
            Fungicide Branch
            Registration Division (7505P)

FROM:	Nicholas Mastrota, Wildlife Biologist
		Melanie Biscoe, Physical Scientist
		Environmental Risk Branch 3
		Environmental Fate and Effects Division (7507P)

REVIEWED	Melissa Panger, Ph.D., Senior Biologist
BY:		Environmental Risk Branch
		Environmental Fate and Effects Division (7507P)
 
THROUGH:	Dana Spatz, Branch Chief
	Environmental Risk Branch 3
		Environmental Fate and Effects Division (7507P)

This memorandum summarizes the potential ecological risks associated with the proposed new uses of the fungicide trifloxystrobin (PC code: 129112) on chickpeas, dry peas, and lentils. The proposed single application rate for use on chickpeas, dry peas, and lentils is 0.119 lb a.i./acre. Up to two applications may be made. The maximum annual rate is 0.24 lb a.i./A.  The rate for the proposed uses is within the range of existing registered uses on food crops and less than the existing rate for use on turf. The ecological risks associated with these new uses are no greater than those of existing uses.

Risk Summary

EFED's Tier I risk assessment indicates that potential ecological risks from trifloxystrobin parent and its isomers resulting from the proposed new uses do not exceed the EPA's level of concern (LOC) for non-endangered species.  However, all proposed uses exceed the endangered species level of concern for acute risk to saltwater invertebrates and terrestrial plants, and uses with aerial application exceed the endangered species LOC for acute risk to freshwater fish.  These risks are similar to those identified in previous risk assessments for other uses of trifloxystrobin.
Previous Risk Conclusions
 
Trifloxystrobin has been previously evaluated by EFED for use on numerous commodities including pome fruits, grapes, cucurbits, peanuts, and turf (New Chemical Review, D244219, D245281, D254206, D254285, D254286); almonds, fruiting vegetables, hops, potatoes, sugar beets, and wheat (D254215, D254220, D254222); root vegetable subgroup 1B (except beet and radish) and leaf petiole subgroup 4B (D286427); barley, oats, sweet corn, and soybeans (D315580, D314187, D318621, D318623, D363130); grass grown for seed (D332979, D332982); asparagus, tropical crops, radish, root vegetables, strawberries (D331915, D339548, D348876), and artichoke (D378918). Detailed summaries of these assessments can be found in the following previous risk assessments: D309489, D331915, D378918. 

Based on previous reviews, EFED concluded that some uses are expected to present risk on an acute basis to freshwater and/or estuarine/marine aquatic organisms (fish and invertebrates); including Federally-listed endangered and threatened species. Those uses include turf, cucurbits, grasses grown for seed, tropical crops, root vegetables, leaf petiole, almonds, fruiting vegetables, hops, and potatoes. Ecological risks are not expected for any of the other registered uses based on previous assessments.
Overview of Pesticide Usage
 
The active ingredient in USF 0728 325 SC Fungicide is the E,E isomer of trifloxystrobin, which referred to generally as trifloxystrobin for the purposes of this risk assessment. New use sites that are proposed for the registration of trifloxystrobin are chickpea, dry pea, and lentil. For all of these proposed new uses, the maximum single-application rate is 0.12 lb a.i./A, and no more than 0.24 lb a.i./A of trifloxystrobin may be applied per year. Up to two applications may be made per year, with a 10- to 14 day interval between applications. The product is sprayed onto the foliage of plants. Spray applications may be made with ground or aerial spray equipment, or through irrigation systems (chemigation).
Environmental Fate and Transport

Trifloxystrobin isomers E,E (parent); E,Z; Z,E; and Z,Z, are expected to be in equilibrium in the environment. For the purposes of this assessment, all four isomers are considered in the exposure estimates using a Total Toxic Residues (TTR) approach. This approach was used to determine the environmental fate data parameters for modeling in conjunction with the Guidance for Selecting Input Parameters in Modeling the Environmental Fate and Transport of Pesticides, Version 2.1, October 22, 2009 and the draft Guidance for Modeling Pesticides Total Toxic Residues (TTR) May 20, 2009.  

Although trifloxystrobin's major degradation product (CGA-321113) comprises >50% of applied trifloxystrobin in some dissipation studies, the available data suggest that CGA-321113 is considerably less toxic to aquatic organisms on an acute and chronic basis than trifloxystrobin (see Appendix 1). Therefore, it is 'anticipated that risk quotients based on chronic studies using trifloxystrobin and its isomers would be protective of aquatic organisms exposed to CGA-321113 on a chronic basis. Since the mode of action of trifloxystrobin (inhibition of cellular respiration) is the same in terrestrial and in aquatic organisms, CGA-321113 is assumed to be also less toxic to terrestrial organisms than the parent. Therefore,  the risk assessment will be based on exposure to the parent compound and the three aforementioned isomers and not CGA-321113.

The chemical names and structures for the trifloxystrobin isomers considered in this assessment are summarized in Table 1. 

Table 1. Chemical identification information for trifloxystrobin isomers
                                   Chemical
                                   Structure

CGA279202, Trifloxystrobin, (Parent) (EE-isomer) 

(E,E)-Methoxyimino-{2-[1-(3-trifluoro methyl-phenyl)-ethylideneaminooxymethyl]-phenyl}-acetic acid methyl ester 

Chemical Abstracts #: 141517-21-7

                                       
CGA357262 (ZZ-isomer) 

(Z,Z)-Methoxyimino-{2-[1-(3-trifluoro methyl-phenyl)-ethylideneamino-oxymethyl]-phenyl}-acetic acid methyl ester

                                       

CGA357261 (ZE-isomer) 

(Z,E)-Methoxyimino-{2-[1-(3-trifluoro methyl-phenyl)-ethylideneaminooxymethyl]-phenyl}-acetic acid methyl ester

                                       
CGA331409 (EZ-isomer) 

(E,Z)-Methoxyimino-{2-[1-(3-trifluoro methyl-phenyl)-ethylideneamino-oxymethyl]-phenyl}-acetic acid methyl ester

                                       

 
Parent: Trifloxystrobin E,E Isomer

Available data suggest that trifloxystrobin is not persistent and has low mobility in the environment. The major routes of degradation and dissipation for trifloxystrobin are associated with alkaline-catalyzed hydrolysis, microbial-mediated metabolism, photodegradation, and soil binding. Hydrolysis of trifloxystrobin is most important under alkaline conditions. Dispersion of trifloxystrobin will also occur in the environment by spray drift, in runoff water and eroded soil. The major degradate in hydrolysis, metabolism and photodegradation on soil is CGA-321113, the free acid degradation product of trifloxystrobin; however, as previously mentioned, CGA-321113 is not considered to be a degradate of concern in this risk assessment. 

Trifloxystrobin has a low solubility (0.61 mg/L @ pH 7) in water. The vapor pressure is 2.55 x 10[-8] torr at 25 °C, and the calculated Henry's Law Constant is 2.25 x 10[-8] atm-m3 mol[-1]. These values suggest that trifloxystrobin is non-volatile under field conditions from water and moist soil surfaces. Volatilization is not a likely route of dissipation. 

Trifloxystrobin is non-persistent in soil. Laboratory studies indicate that biotransformation is an important route of trifloxystrobin transformation in aerobic soil. Trifloxystrobin degraded rapidly in aerobic soils with half-lives ranging between 0.41 and 0.91 days. The photo-induced isomerization half-life (t1/2) was 2.1 days on soils. Based upon the soil organic carbon coefficient, KFOC (median KFOC =2709 mL/goc), trifloxystrobin would fall into the slightly mobile class. There is no correlation between soil organic matter and KF (r[2]=0.04, p-value=0.72) and the coefficient of variation for the KF's is lower than that for the KFOC's.  This indicates that sorption is controlled by factors other than soil organic carbon content.

Laboratory studies indicate that trifloxystrobin is also not persistent in water. The aerobic and anaerobic metabolism half-lives for trifloxystrobin are each less than one day. Hydrolysis of trifloxystrobin is dependent on pH; while trifloxystrobin is stable to hydrolysis under acidic conditions (pH 4), it readily hydrolyzes in alkaline conditions (t1/2 = 55.2 days at pH 7 and 0.83 days at pH 9). In the aquatic environment, the photo-induced isomerization half-life (t1/2) was 14.8 days.  

Trifloxystrobin demonstrated a biphasic degradation pattern in field dissipation studies conducted in California, New York, and Georgia. For the first degradation phase, trifloxystrobin half-life values ranged from 1.9 to 24 days. In the second degradation phase, half-life values ranged from 6.5 days to 4 months. 

The log Kow of 4.5 suggests that trifloxystrobin may bioaccumulate.  Trifloxystrobin has bioconcentration factors in bluegill sunfish edible tissues of 130-166X, 1172-1144X for nonedible tissues, and 542-547X in whole fish.  The bioaccumulation plateau was rapid (3 days post exposure).  However, depuration was rapid, with 96.7-98.1% of the total [[14]C]residues accumulated by exposure day 28 eliminated from all tissues by 7 days in the 0.16 ug/L system, and 98.3-98.5% eliminated from all tissues by 14 days in the 1.6 ug/L system.  Due to the relatively low fish bioconcentration factors in fish tissue, rapid aquatic biotransformation to CGA-321113 (acid) and the rapid depuration of trifloxystrobin observed in the fish study, bioaccumulation is unlikely.

Trifloxystrobin Total Toxic Residues (TTR): Parent and Isomers of Concern in Aquatic Environments

The trifloxystrobin isomers considered in the TTR approach are expected to have the same physical and chemical properties as the parent isomer.

The proposed degradation pathways of trifloxystrobin in aquatic systems indicate that the E,Z; Z,E; and Z,Z isomers are in equilibrium with the parent (E,E) isomer in aquatic environments (DP405629).  

The Z,E isomer is the major transformation product resulting from photo-induced isomerization of the parent in aqueous environments. The Z,E isomer formed up to 63.8% and 1% of the applied radioactivity in the aqueous photolysis and aerobic soil metabolism studies, respectively. The Z,E isomer was not detected in the other fate laboratory studies, and was not detected below 18 inches in the terrestrial field dissipation studies. 

The Z,E isomer is expected to be more mobile than the parent, with KFOC's ranging from 389 to 567 mL/goc. Sorption is highly dependent on soil organic carbon content, as the KF's are highly correlated with percent organic carbon (r[2]=0.99, p-value=7e[-4]) and the coefficient of variation for the KFOC's is lower than that for the KF's. Because the Z,E isomer is more mobile than the parent isomer, the KFOC for the Z,E isomer is used in modeling estimated exposure concentrations.

The Z,Z isomer is a minor transformation product in the aqueous photolysis, soil photolysis, and aerobic soil metabolism studies, forming up to 9.1%, 4.1%, and 0.5% of applied radioactivity, respectively. The Z,Z isomer was not detected in the other fate laboratory studies. In the terrestrial field dissipation studies, it was detected once in the 12-18 inch segments, and not detected below 18 inches. An adsorption/desorption study is not available for this isomer.

The E,Z isomer is a minor transformation product in the aerobic soil metabolism, soil photolysis, and aerobic aquatic metabolism studies, forming up to 4.2%, 4.1%, and 0.4% of applied radioactivity, respectively. The E,Z isomer was not detected in the other fate laboratory studies or in the terrestrial field dissipation studies. An adsorption/desorption study is not available for this isomer.

The aqueous photolysis half-life for trifloxystrobin TTR is 54.7 days and the aerobic aquatic metabolism half-life for trifloxystrobin TTR is 0.492 days. Aerobic soil metabolism half-lives could not be calculated for trifloxystrobin TTR because the submitted studies did not measure the non-parent isomers of concern until mid-way through each study. Although an uncertainty, this is not expected to substantially change the estimated exposure concentrations, as the non-parent isomers were observed at < 5% applied radioactivity in these studies.  The soil photolysis half-life for trifloxystrobin TTR was not calculated, as it is not currently used in aquatic exposure modeling. The half-lives for trifloxystrobin TTR in the other laboratory studies are the same as those for the parent.

Environmental fate data for trifloxystrobin and trifloxystrobin TTR are summarized in Table 2.

Table 2. Physical/Chemical Properties and Environmental Fate Data for Trifloxystrobin and Trifloxystrobin TTR
Parameter
                              Trifloxystrobin[1]
                            Trifloxystrobin TTR[2]
                                    Source
Molecular Weight
                                     408.4
                                 MRID 44052801
Solubility (20 [◦]C)
                               0.61 mg/L at pH7
                                 MRID 44052801
Vapor Pressure (20 [◦]C)
                               2.55e[-08] mm Hg
                              DP Barcode D254920
Henry's Law Constant
                           2.2e[-08]atm m[3] mol[-1]
                               DP Barcode 405629
Hydrolysis Half-life
                                Stable at pH 4
                               55.2 days at pH 7
                               0.83 days at pH 9
                                 MRID 44496727
Aquatic Photolysis Half-life
                               14.8 days at pH 5
                               54.7 days at pH 5
                                 MRID 44496727
TTR half-life calculated using NAFTA Degradation Kinetics Guidance (2012) and includes isomers identified in the study and expected to be in equilibrium with the parent in aquatic environments: CGA-357261 and CGA-357262
Photolysis on soil Half-life
                                   2.1 days
                               Not calculated[3]
                                 MRID 44496729
Aerobic Soil Metabolism Half-life
                           0.74, 0.41, and 0.91 days
                                       
                          Mean = 0.69 d, Std = 0.25 d
                               Not calculated[4]
                                 MRID 44496732
                                 MRID 44496730
                                 MRID 44496731
Anaerobic Aquatic Metabolism Half-life
                                   0.72 days
                                 MRID 44496733
                                       
No isomers identified in this study are expected to be in equilibrium with the parent in aquatic environments.
                                       
Aerobic Aquatic Metabolism Half-life
                                   0.60 days
                                  0.492 days
                                   (tR IORE)
                                 MRID 44496734

TTR half-life calculated using NAFTA Degradation Kinetics Guidance (2012) and includes an isomer identified in the study that is expected to be in equilibrium with the parent in aquatic environments: CGA-331409.
Organic Carbon Partition Coefficient (KFOC) (mL/g-oc)
                       Data for the parent (E,E) isomer:
                                       
                       2354, 951, 3064, 3927, 9871, 951 
                                       
       KF vs. organic matter coefficient of determination (r[2]) = 0.03
                                p-value = 0.72
                           Data for the Z, E isomer:
                                       
                            476, 526, 479, 389, 567
                                       
KF vs. organic matter coefficient of determination (r[2]) = 0.99, p-value = 0.001
                            MRID 44496802 (Parent)
                          MRID 44496805 (Z,E isomer)
                                       
For trifloxystrobin parent and the three isomers expected to be present in aquatic environments, only two adsorption desorption studies are available and considered  -  one for the parent and one for CGA-357261. CGA-357261 is more mobile and is therefore used as the model input.
Soil Partition Coefficient (KF)
(mL/g)
                       Data for the parent (E,E) isomer:
                                       
                                6.8 Loamy Sand
                                7.7 Sandy Loam
                         16.0 Low Organic Matter Sand
                         59.4 High Organic Matter Sand
                                91.8 Clay Loam
                                33.2 Silt Loam
                                       
                            Mean = 35.8; Std = 33.8
                           Data for the Z, E isomer:
                                       
                                   14.9 Loam
                                       
                                12.8 Clay Loam
                                       
                            2.8 Hanford Sandy Loam
                                       
                            3.2 Saw-Wake Sandy Loam
                                       
                                   4.6 Sand
                                       
                             Mean = 7.7 Std = 5.7
                                       
[1] Trifloxystrobin Parent is the E,E isomer
[2] Trifloxystrobin TTR includes the parent E,E, isomer and the E,Z; Z,E; and Z,Z, isomers.
[3] Value currently not used in modeling, and was therefore not calculated for trifloxystrobin TTR.
4 Although the Z,E; Z,Z; and E,Z isomers were detected in the aerobic soil metabolism studies at levels below 5% of applied radioactivity, the studies did not report data for these isomers during the initial stages of each study. As a result, reliable half-lives for trifloxystrobin TTR could not be calculated. 

Estimation of Exposure

Aquatic Exposure

The aquatic estimated environmental concentrations (EECs) in surface water were estimated with the Surface Water Concentration Calculator (SWCC version 1.106). The SWCC generates daily exposures and 1-in-10-year EECs of trifloxystrobin that may occur in surface water bodies adjacent to application sites receiving trifloxystrobin through runoff and spray drift. A detailed description, documentation, and direct links for running the SWCC can be found at http://www.epa.gov/oppefed1/models/water/index.htm.
 
 EECs for trifloxystrobin TTR were estimated for the Michigan Beans, Washington Beans, and California Row Crop scenarios, using the maximum application rates on the proposed label and assuming an annual application for thirty years. Details on the pesticide application assumptions used for the modeling are summarized in Table 3, and the environmental fate properties used for modeling are summarized in Table 4. The maximum peak, 21-day, 60-day means for the trifloxystrobin new uses are summarized in Table 5. A sample SWCC output file from the Michigan Beans (aerial) modeling is in Appendix 3.
   
Table 3. Summary of application input parameters used in aquatic modeling for total toxic residues.
Model Input Parameter
                             Input Value and Unit
                                    Source/
                                    Comment
SWCC Scenarios
                                   MI Beans
                               WA Beans (NMC)[1]
                            CA Row Crop (RLF v2)[2]
Proposed End-Use Label (EPA Reg. # 264-1055)
Maximum Single Application Rate
                                0.1344 kg ai/ha

Maximum Number of Applications per Year
                                       2

Method of Application
                                    Ground
                                    Aerial
Proposed End-Use Label (EPA Reg. # 264-1055) allows chemigation as well as ground and aerial applications; ground application is assessed instead of chemigation and is assumed to be protective of potential exposures from chemigation.
Application Efficiency
                                     0.99
                                     0.95
December 2013 EFED Spray Drift Guidance
Spray Drift Fraction
                                     0.062
                                     0.125

Type of Application
                                    Foliar
Proposed End-Use Label (EPA Reg. # 264-1055).
Initial Date of Application 
(month/day)
                               MI Beans: June 1 
                           WA Beans (NMC): June 16 
                       CA Row Crop (RLF v2): January 1 
Initial application dates are assumed to occur on the crop emergence dates listed in scenario metadata.
Minimum Interval between Applications
                                    10 days
Proposed End-Use Label (EPA Reg. # 264-1055)

[1] Scenario developed for the N-Methyl Carbamate Cumulative Risk Assessment
[2] Scenario developed for the Red-Legged Frog Endangered Species Risk Assessment

Table 4. Summary of environmental fate input parameters used in aquatic modeling for total toxic residues.
Model Input Parameter
                             Input Value and Unit
                                Source/Comments
Foliar Half-life
                                    Stable
Assumption based on Input Parameter Guidance
Molecular Weight
                                 408.37 g/mol
Calculated molecular weight of trifloxystrobin (C20H19F3N2O4)
Vapor pressure (25°C)
                              2.55 x 10[-8] torr
USEPA Fact Sheet reports 3.4 x 10[-6] torr (@25 °C), PMRA Reg2004-03 and Trifloxystrobin (213) report 3.4 x 10[-6] Pa @ 25 °C
Solubility in water 
(20C, pH 7)
                                   0.61 mg/L
MRID 44502801
Hydrolysis half-life 
(25+-1C, pH 4)
                                    Stable
MRID 44496727
Aqueous photolysis half-life (25+-1C, pH 5)
                                   54.7 days
MRID 44496727

Aerobic soil metabolism half-life (25+-1°C)
                                   0.96 days
MRIDs 44496732, 44496730, 44496731
The 90th percentile upper bound of mean (0.74, 0.41, and 0.91 days). 
Anaerobic soil metabolism half-life
                                    Stable
No Data Submitted
Aerobic aquatic metabolism half-life (25°C)
                                   1.48 days
MRID 44496734
3 x the aerobic aquatic metabolism half-life for a single test system (0.492 days), per input parameter guidance. 
Anaerobic aquatic metabolism half-life (20-29C)
                          2.16 days (assume 25 deg C)
MRID 44496733
3 x the anaerobic aquatic metabolism half-life for a single test system (0.72 days). 
Freundlich soil-water partition coefficient for isomer CGA-357261 (Koc) (25+-1°C)
                                 487.4 mL/g-oc
MRID 44496802
Mean Koc for isomer CGA-357261. 

Table 5. SWCC Trifloxystrobin TTR Estimated Environmental Concentrations (EECs) for the Proposed New Uses
Crop
                              Application Method
                           Maximum Application Rate
                                   (lb a.i./
                                     acre)
                               # of Applications
                         Minimum Application Interval
                                    (days)
                                   Scenario
                                 (State crop)
                                       
                                1st Appl. date
                                   (day-mo)
                                 EECs* (ug/L)
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                     Peak
                                    21 day
                                    60 day
Chickpea, Dry Peas, Lentil
                                 Aerial Spray
                                     0.12
                                       2
                                      10
                                   MI Beans
                                     1-Jun
                                     1.08
                                     0.341
                                     0.123

                                       
                                       
                                       
                                       
                                WA Beans (NMC)
                                    16-Jun
                                     0.902
                                     0.289
                                     0.103

                                       
                                       
                                       
                                       
                              CA Row Crops (RLF)
                                     1-Jan
                                     1.04
                                     0.479
                                     0.190

                                 Ground Spray
                                     0.12
                                       2
                                      10
                                   MI Beans
                                     1-Jun
                                     0.667
                                     0.205
                                    0.0736

                                       
                                       
                                       
                                       
                                WA Beans (NMC)
                                    16-Jun
                                     0.448
                                     0.143
                                    0.0511

                                       
                                       
                                       
                                       
                              CA Row Crops (RLF)
                                     1-Jan
                                     0.540
                                     0.258
                                     0.101
*Values in bold are the most conservative values. 

Terrestrial Exposures

The T-REX Model (version 1.5.2) was used to calculate EECs for wildlife food items. To calculate maximum EECs, the model assumed two applications at the maximum application rate of 0.12 lb a.i./A, separated by a 10-day interval.  EECs represent predicted peak residue levels which are expected to occur immediately after the second application. The model's default foliar half-life of 35-day is used, which is expected to account for persistence of trifloxystrobin and its isomers. 

Table 6 provides predicted dietary-based EECs for the proposed new use on chickpeas, dry peas, and lentils.

Table 6. Terrestrial Dietary-Base EECs for Proposed New Uses of Trifloxystrobin
                                     Crop 
                                  Food Item 
                                   EEC (ppm)
                          Chickpea, Dry Peas, Lentil
Short Grass
                                     52.4

Tall Grass
                                     24.0

Broadleaf Plants
                                     29.5

Fruits/Pods/Seeds
                                     3.28

Arthropods
                                     20.5

The EECs were converted to an oral dose and compared with the oral toxicity data. These "dose-based" EECs were calculated for small, medium, and large birds and mammals. Body weights of 20 g, 100 g, and 1000 g were assumed for small, medium, and large birds, respectively, and body weights of 15 g, 35 g, and 1000 g were assumed for small, medium, and large mammals, respectively. Predicted dose-based EECs are presented in 
Table 7.

Table 7. Terrestrial Dose-Based EECs Proposed New Uses of Trifloxystrobin
                                     Crop 
                                   Food Item
                                EEC (mg/kg-bw)
                                       
                                       
                                     Small
                                    Medium
                                     Large
                                  Avian EECs
                          Chickpea, Dry Peas, Lentil
Short Grass
                                     59.7
                                     34.1
                                     15.2

Tall Grass
                                     27.4
                                     15.6
                                     6.99

Broadleaf Plants
                                     33.6
                                     19.2
                                     8.57

Fruits/Pods/Seeds
                                     3.73
                                     2.13
                                     0.95

Arthropods
                                     23.4
                                     13.3
                                     5.97

Seeds
                                     0.83
                                     0.47
                                     0.21
                                Mammalian EECs
                          Chickpea, Dry Peas, Lentil
Short Grass
                                     50.0
                                     34.6
                                     8.01

Tall Grass
                                     22.9
                                     15.8
                                     3.67

Broadleaf Plants
                                     28.1
                                     19.4
                                     4.51

Fruits/Pods/Seeds
                                     3.12
                                     2.16
                                     0.50

Arthropods
                                     19.6
                                     13.5
                                     3.14

Seeds
                                     0.69
                                     0.48
                                     0.11

TerrPlant (Version 1.1.2) was used to calculate EECs for non-target plant species inhabiting dry and semi-aquatic (wetland) areas. Parameter values for application rate, drift assumption and incorporation depth are based upon the use and related application method. A runoff value of 0.01 is utilized based on trifloxystrobin's solubility, which is classified by TerrPlant as <10 mg/L. Predicted terrestrial plant EECs are provided in Table 8.

Table 8. Terrestrial Plant EECs for the New Uses of Trifloxystrobin
                               Exposure Scenario
                                      EEC

                              Ground Applications
                              Aerial Applications
Runoff to dry areas
                                    0.0012
                                    0.0012
Runoff to semi-aquatic areas
                                     0.012
                                     0.012
Spray Drift
                                    0.0012
                                     0.006
Total for dry areas
                                    0.0024
                                    0.0072
Total for semi-aquatic areas
                                    0.0132
                                     0.018
Ecological Effects Characterization

Effects to Aquatic Organisms

Table 9 provides aquatic toxicity data that was used to assess the risk of trifloxystrobin to aquatic plants and animals. The toxicity data indicate that trifloxystrobin is very highly toxic to fish and aquatic invertebrates on an acute exposure basis. Data for green algae (Pseudokirchneriella subcapitata) indicate toxicity to algae occurs at relatively low exposure levels, with toxicity endpoints comparable to the acute toxicity endpoints for fish and aquatic invertebrates. On a chronic basis, the most sensitive test species was the waterflea (Daphnia magna), in which significant growth and reproduction was observed at 5.98 ug ai/L. The waterflea NOAEC was established at 2.76 ug ai/L. 

Table 9. Summary of the Most Sensitive Endpoints from Aquatic Toxicity Studies for Trifloxystrobin 
Taxonomic Group
                                  Study Type
                               Surrogate Species
                                Toxicity Value
              (all units in terms of measured active ingredient)
                         Acute Toxicity Classification
                                       
                                    Source
Freshwater fish[1]
Acute
Rainbow Trout
(Oncorhynchus mykiss)
96-hr LC50 = 14.3 ug/L
Very highly toxic
MRID 44502803

Chronic (Early Life- Stage)
Rainbow Trout
NOAEC = 4.3 ug/L
LOAEC = 7.7 ug/L
Endpoint: Post-hatch survival
--
MRID 44502804
Freshwater invertebrates
Acute
Water Flea 
(Daphnia magna)
48-hr EC50 = 25.3 ug/L
Very highly toxic
MRID 44496611

Chronic
Water Flea 
NOAEC = 2.76 ug/L
LOAEC = 5.98 ug/L
Endpoint: Dry weight and fecundity
--
44496615
Estuarine/marine fish
Acute
Sheepshead Minnow (Cyprinodon variegatus)
96-hr LC50 = 78.0 ug/L
Very highly toxic
MRID 44496612
Estuarine/marine invertebrates
Acute
Mysid
(Americamysis bahia)
96-hr EC50 = 8.62 ug/L 
Very highly toxic
44496614
Aquatic plants and algae
Vascular
Duckweed 
(Lemna gibba)
NOAEC = 410 ug/L[2]
14-d EC50 >1930 ug/L[2]
--
MRID 44496725

Non-vascular
Green Algae (Pseudokirchneriella 
subcapitata)
NOAEC = 10.5 ug/L
5-d EC50 = 37.1 ug/L
--
MRID 44496724
1 Freshwater fish may be surrogates for aquatic-phase amphibians.
2 These results are uncertain because the test material was unstable and renewals were not done, resulting in dramatic declines of the test material during the duration of the exposure period. The study was classified as Supplemental.

Available toxicity data for CGA-321113, the major degradation product of trifloxystrobin, are given in Table 10. The data indicate that this compound is much less toxic to fish, aquatic invertebrates, and algae than the parent compound. CGA-321113 is classified as practically nontoxic to fish and aquatic invertebrates on an acute basis. A supplemental life-cycle study with CGA-321113 established an NOAEC for chronic effects at 3.2 mg/L. The chronic toxicity endpoints derived from this study were greater than 3 orders of magnitude higher than that obtained for this species when tested with the parent compound. Although the lack of evaluation of growth endpoints (dry weight or length) may make this study less sensitive than a study that adhered to the test guideline, the study provides sufficient evidence to conclude that this degradation product has much less chronic toxicity than the parent compound.

Table 10. Summary of the Most Sensitive Endpoints from Aquatic Toxicity Studies for CGA-321113
Taxonomic Group
                                  Study Type
                               Surrogate Species
                                Toxicity Value
              (all units in terms of measured active ingredient)
                                     Acute
                            Toxicity Classification
                                    Source
                                  (MRID No.)
Freshwater fish[1]
Acute
Rainbow trout
96-hr EC50 > 106 mg/L
Practically nontoxic
44527502
Freshwater invertebrates
Acute
Water Flea
(Daphnia magna)
48-hr EC50 > 95.3 mg/L
Practically nontoxic
44527503

Chronic
Water Flea
 NOAEC= 3.2 mg/L[2]
LOAEC= 10.0 mg/L[2]
Endpoint: Survival
--
44869701
Aquatic plants and algae
Non-vascular
Green Algae (Pseudokirchneriella 
subcapitata)
NOAEC = 15.7 mg/L
5-d EC50 = 77.1 mg/L
--
44496724
1 Freshwater fish may be surrogates for aquatic-phase amphibians.
2 This study was classified as Supplemental because it did not follow the experimental design prescribed by the test guideline. The study did not evaluate growth parameters (dry weight or length) and thus the results may not be as sensitive as a fully acceptable study.
Effects to Terrestrial Organisms

Table 11 provides toxicity data that was used to assess the risk of trifloxystrobin to terrestrial plants and animals. All available acute oral and subacute dietary studies indicate that trifloxystrobin is practically nontoxic to birds, mammals, and bees on an acute basis. Acute testing with the rat (Rattus norvegicus) show that acute toxicity to mammals from the dermal and inhalation routes of exposure is also low. With chronic exposure, trifloxystrobin did not cause any observable toxic effect to birds at dietary concentrations up to 320 mg a.i./kg-diet. Chronic toxicity to birds at exposures greater than 320 mg ai/kg-diet is not known; however, maximum residues on terrestrial food items from the proposed uses are not expected to reach this concentration. Chronic toxicity studies with the laboratory rat showed bodyweight effects to adult and young with chronic exposures of 750 mg a.i./kg-diet and above, with an NOAEL established at 500 mg a.i./kg-diet. No reproductive impairment was noted in rats exposed to up to 1500 mg a.i./kg-diet. Testing with the honey bee found that trifloxystrobin is practically nontoxic to bees. Tier I phytotoxicity studies found that exposure of trifloxystrobin to terrestrial plants at approximately 0.25 lb a.i./A caused some inhibition of growth (no more than 13% inhibition). These studies are adequate for demonstrating that the proposed uses of trifloxystrobin would have little toxicity to target plants that are sprayed directly at the maximum label application rate. 

Table 11. Summary of the Most Sensitive Endpoints from Terrestrial Toxicity Studies for Trifloxystrobin 
                                Taxonomic Group
                                  Study Type
                               Surrogate Species
                                Toxicity Value
                   (all units in terms of active ingredient)
                         Acute Toxicity Classification
                                    Source
                                  (MRID No.)
Birds[1]
Acute
Bobwhite (Colinus virginianus)
LD50 > 2000 mg/kg-bw
(No mortality)
Practically nontoxic
44496606

Sub-acute dietary
Bobwhite and Mallard (Anas platyrhynchos)
LC50 > 5050 mg/kg-diet
(No treatment-related mortality)
Practically nontoxic
444966-07
444966-08

Chronic
Bobwhite quail
NOAEC = 320 mg/kg-diet
LOAEC > 320 mg/kg-diet
                                      --
44496609
Mammals
Acute Oral
Laboratory rat 
(Rattus norvegicus)
LD50 > 5000 mg/kg-bw
(No mortality, minor sublethal effects[2])
Practically nontoxic
44496622

Acute Dermal
Laboratory rat 
LD50 > 2000 mg/kg-bw
Toxicity Category III-IV
44496627

Acute Inhalation
Laboratory rat 
LC50 > 4.65 mg/L
Toxicity Category IV
44496630

Chronic
(2-Gen. Repro.)
Laboratory rat 
(Rattus norvegicus)
Parental:
NOAEL: 50 ppm
LOAEL: 750 ppm
Endpoint: Reduced body weight, body weight gain, and food consumption

Offspring:
NOAEL: 50 ppm
LOAEL: 750 ppm
Endpoint: Reduced body weight

Reproduction:
NOAEL: 1500 ppm
LOAEL: >1500 ppm
                                      --
44496710
Insects
Acute contact
Honey bee 
(Apis mellifera L.)
LD50 > 200 ug/bee
Practically nontoxic
44496726
Terrestrial plants
Seedling Emergence
Dicot  -  cabbage
13% inhibition in dry weight at 0.249 lb a.i./A
                                      --
44496723

Monocot  -  ryegrass
7% inhibition in dry weight at 0.249 lb a.i./A

Vegetative vigor
Dicot  -  tomato
10% inhibition in dry weight at 0.249 lb a.i./A

44496723

Monocot  -  ryegrass
9% inhibition in dry weight at 0.249 lb a.i./A

1 Birds represent surrogates for terrestrial-phase amphibians and reptiles.
[2] Observed sublethal effects included hypersensitivity to touch, red stained face, excessive salivation, soft or watery stool, and dark stained or wet urogenital area, and decreased body weight (3-4%) in three of five females during the 7 to 14 day interval.

No in vivo studies are available on the toxicity of CGA-321113 to terrestrial organisms. However, an in vitro study of this compound using rat hepatocyte cultures has been submitted to the EPA (MRID 44496720). This study found that CGA-321113 does not express the toxic mechanism of action of the parent compound, i.e., inhibition of mitochondrial respiration, and is much less toxic to hepatocyte cells than is the parent. The NOAEL was 600 uM for CGA-321113 compared to <30 uM for trifloxystrobin. These results agree with the findings of aquatic toxicity studies which also showed that CGA-321113 is much less toxic to animals and plants than trifloxystrobin.
Ecological Risk Estimation 

Risk characterization compares EECs to toxicity endpoints to determine whether the proposed uses pose ecological risks that exceed EPA's levels of concern (LOC). In a deterministic approach, a single point estimate of toxicity is divided by an exposure estimate to calculate a risk quotient (RQ). The RQ is then compared to Agency LOCs, which serve as criteria for categorizing potential risk to non-target organisms (see Appendix 2). In this assessment, RQs were calculated with EECs that represent total concentrations of all racemic isomers of trifloxystrobin.

Risk to Aquatic Organisms

Acute aquatic RQs range from <0.01 to 0.13 (Table 12). Because acute RQs are less than the acute LOC for non-listed species (0.5), the proposed uses are not expected to pose high acute risk to fish and aquatic invertebrates. However, RQs for saltwater invertebrates are above the endangered species LOC. The RQ for freshwater fish also exceeded the listed species LOC for aerial applications. 

Chronic RQs ranged from <0.01 to 0.06 (Table 13). Because all of the chronic RQs were less than the chronic LOC (1), the proposed uses are expected to pose minimal chronic risk to fish and aquatic invertebrates.

Table 12. Acute RQs for Fish and Aquatic Invertebrates
Use Scenario
                                 Habitat Type
                                   Peak EEC
                                   ( ug/L)
                               EC50 (ug a.i./L)
                               RQ[2] (EEC/EC50)

                                       
                                       
                                     Fish
                                   Inverts.
                                     Fish
                                   Inverts.
Aerial Applications
2 applications at 0.119 lb a.i./A, separated by 10-day interval
                                  Freshwater
                                     1.08
                                     14.3
                                     25.3
                                    0.076*
                                     0.043

                                   Saltwater
                                     1.08
                                     78.0
                                     8.62
                                     0.014
                                     0.13*
Ground Applications
2 applications at 0.119 lb a.i./A, separated by 10-day interval
                                  Freshwater
                                     0.667
                                     14.3
                                     25.3
                                     0.047
                                     0.026

                                   Saltwater
                                     0.667
                                     78.0
                                     8.62
                                   <0.01
                                    0.077*
[*]Exceeds the LOC for Acute endangered species (RQ >= 0.05)

Table 13. Chronic RQs for Fish and Aquatic Invertebrates
Use Scenario
                                 Habitat Type
                                  Average EEC
                                  (ug/L)[1]
                              NOAEC (ug a.i./L)
                               RQ[1] (EEC/NOAEC)

                                       
                                       
                                     Fish
                                   Inverts.
                                     Fish
                                   Inverts.
Aerial Applications
2 applications at 0.119 lb a.i./A, separated by 10-day interval
                                  Freshwater
                                  21-d: 0.479
                                  60-d: 0.190
                                      4.3
                                     2.76
                                     0.044
                                     0.17

                                 Saltwater[2]
                                  21-d: 0.479
                                  60-d: 0.190
                                     23.5
                                     0.94
                                   <0.01
                                     0.51
Ground Applications
2 applications at 0.119 lb a.i./A, separated by 10-day interval
                                  Freshwater
                                  21-d: 0.258
                                  60-d: 0.101
                                      4.3
                                     2.76
                                     0.023
                                     0.060

                                 Saltwater[2]
                                  21-d: 0.258
                                  60-d: 0.101
                                     23.5
                                     0.94
                                   <0.01
                                     0.27
[1] The 60-d average EEC is used for fish RQs, whereas the 21-d EEC is used for invertebrate RQs.
[2] Chronic endpoints for saltwater species were estimated from acute toxicity endpoints on acute-to-chronic ratios (ACRs) derived from freshwater species. The ACR was 3.33 for fish and 9.17 for crustaceans.

For aquatic vascular and non-vascular plants, RQs range from <0.01 to 0.029 for non-listed species, and <0.01 to 0.10 for listed species (Table 14). Because all of the RQs are less than the LOC for aquatic vascular and non-vascular plants (1), the proposed new uses are expected to pose minimal risk to listed and non-listed species of aquatic vascular and non-vascular plants.

Table 14. RQs for Vascular and Non-vascular Aquatic Plants 
Use Scenario
                                   Peak EEC
                                    (ug/L)
                             Vascular Plant RQ[1]
                           Non-Vascular Plant RQ[2]

                                       
                              Non-listed Species
                                  (EEC/EC50)
                                Listed Species
                                  (EEC/NOEC)
                              Non-listed Species
                                  (EEC/EC50)
                                Listed Species
                                  (EEC/NOEC)
Aerial Applications
2 applications at 0.119 lb a.i./A, separated by 10-day interval
                                     1.08
                                   <0.01
                                   <0.01
                                     0.029
                                     0.10
Ground Applications
2 applications at 0.119 lb a.i./A, separated by 10-day interval
                                     0.667
                                   <0.01
                                   <0.01
                                     0.018
                                     0.063
[1] Based on the green algae EC50 of 0.024 ppm
[2] Based on the duckweed EC50 of >1.93 ppm 

In conclusion, the risk assessment for aquatic organisms indicates that the new use of trifloxystrobin on chickpeas, dry peas, and lentils will not pose a risk to any aquatic organism that exceeds the EPA LOC for non-listed species, but the LOC for listed saltwater invertebrates is exceeded, as is the LOC for listed freshwater fish when trifloxystrobin is applied by air.

Risk to Terrestrial Organisms

The T-REX model was used to calculate acute and chronic risk quotients (RQs) for the proposed new uses on chickpea, dry peas, and lentils. For acute risk, the non-definitive "greater than" value generated by the acute toxicity values were entered into the model as if they were definitive values. Thus, while the actual acute RQs are unknown, we know that they are less than the RQs generated by this approach. This approach is, therefore, appropriate for conducting a conservative screen of acute risk. Endpoints from chronic studies were definitive, and thus the chronic RQs are the actual values.

For birds, acute dose-based RQs ranged from <0.01 to 0.06 (Table 15), and acute dietary-based RQs were all less than or equal to 0.01 (Table 17). All acute RQs were less than the LOC for risk to non-endangered species (0.5), as well as the LOC for risk to threatened and endangered species (0.1). As mentioned above, these RQs are conservative since they were calculated using the limit dose of 2000 mg a.i/kg and no mortality was observed at this limit dose. For chronic risk, RQs ranged from 0.01 to 0.16 (Table 17). All chronic RQs were less than the EPA's LOC for chronic risk (1.0). In conclusion, the risk assessment indicates that the proposed new uses will pose minimal risk to birds, and are not expected to directly harm any threatened or endangered (listed) species of birds. These conclusions also apply to reptiles and terrestrial-phased amphibians, for which birds serve as a surrogate.

For mammals, acute dose-based acute RQs were all less than 0.01 (Table 15). All acute RQs were therefore less than the LOC for risk to listed species (0.1) as well as the LOC for non-listed species (0.5). Chronic dose-based RQs ranged from <0.01 to 0.30 (Table 16) and chronic dietary-based RQs ranged from <0.01 to 0.03 (Table 17). All chronic RQs were less than the EPA's LOC for chronic risk (1.0). In conclusion, the risk assessment indicates that the proposed new uses will pose minimal risk to mammals, and are not expected to directly harm any listed species of mammals.

Table 15. Acute Terrestrial Dose-Based RQs for Proposed New Uses of Trifloxystrobin
                                     Crop
                                   Food Item
                                 Risk Quotient
                                       
                                       
                                     Small
                                    Medium
                                     Large
                                   Birds[1]
                          Chickpea, Dry Peas, Lentil
Short Grass
                                     0.06
                                     0.03
                                     0.01

Tall Grass
                                     0.03
                                     0.01
                                   <0.01

Broadleaf Plants
                                     0.03
                                     0.01
                                   <0.01

Fruits/Pods/Seeds
                                   <0.01
                                   <0.01
                                   <0.01

Arthropods
                                     0.02
                                     0.01
                                   <0.01

Seeds
                                   <0.01
                                   <0.01
                                   <0.01
                                  Mammals[2]
                          Chickpea, Dry Peas, Lentil
Short Grass
                                   <0.01
                                   <0.01
                                   <0.01

Tall Grass
                                   <0.01
                                   <0.01
                                   <0.01

Broadleaf Plants
                                   <0.01
                                   <0.01
                                   <0.01

Fruits/Pods/Seeds
                                   <0.01
                                   <0.01
                                   <0.01

Arthropods
                                   <0.01
                                   <0.01
                                   <0.01

Seeds
                                   <0.01
                                   <0.01
                                   <0.01
   [1] Assumed bodyweights for small, medium, and large birds are 20 g, 100 g, and 1000 g, respectively. Avian toxicity is based on the LD50 for the bobwhite (>2000 mg a.i./kg-bw, MRID 44496606). The weight-adjusted LD50 estimates are 1038, 1322, and 1867 mg a.i./kg-bw for small, medium, and large birds, respectively.
   [2] Assumed bodyweights for small, medium, and large mammals are 15 g, 35 g, and 1000 g, respectively. Mammalian toxicity is based on the LD50 for the laboratory rat (>5000 mg a.i./kg-bw, MRID 44496622). The weight-adjusted LD50 estimates are 10,890, and 8891, and 3846 mg a.i./kg-bw for small, medium, and large birds, respectively.
   

Table 16. Chronic Mammalian Dose-Based RQs for Proposed New Uses of Trifloxystrobin
                                     Crop
                                   Food Item
                                 Risk Quotient
                                       
                                       
                                     Small
                                    Medium
                                     Large
                          Chickpea, Dry Peas, Lentil
Short Grass
                                     0.30
                                     0.26
                                     0.14

Tall Grass
                                     0.14
                                     0.12
                                     0.06

Broadleaf Plants
                                     0.17
                                     0.15
                                     0.08

Fruits/Pods/Seeds
                                     0.02
                                     0.02
                                     0.01

Arthropods
                                     0.12
                                     0.10
                                     0.05

Seeds
                                   <0.01
                                   <0.01
                                   <0.01
   [1] Assumed bodyweights for small, medium, and large birds are 20 g, 100 g, and 1000 g, respectively. Avian toxicity is based on the LD50 for the bobwhite (>2000 mg a.i./kg-bw, MRID 44496606). The weight-adjusted LD50 estimates are 1038, 1322, and 1867 mg a.i./kg-bw for small, medium, and large birds, respectively.
   [2] Assumed bodyweights for small, medium, and large mammals are 15 g, 35 g, and 1000 g, respectively. Mammalian toxicity is based on the LD50 for the laboratory rat (>5000 mg a.i./kg-bw, MRID 44496622). The weight-adjusted LD50 estimates are 10,890, and 8891, and 3846 mg a.i./kg-bw for small, medium, and large birds, respectively.

Table 17. Terrestrial Dietary-Base Acute and Chronic RQs for Proposed New Uses of Trifloxystrobin
                                     Crop 
                                  Food Item 
                                      RQs
                                       
                                       
                                     Acute
                                    Chronic
                                   Birds[1]
                          Chickpea, Dry Peas, Lentil
Short Grass
                                     0.01
                                     0.16

Tall Grass
                                   <0.01
                                     0.08

Broadleaf Plants
                                     0.01
                                     0.09

Fruits/Pods/Seeds
                                   <0.01
                                     0.01

Arthropods
                                   <0.01
                                     0.06
                                  Mammals[2]
                          Chickpea, Dry Peas, Lentil
Short Grass
                                    N/A[3]
                                     0.03

Tall Grass
                                      N/A
                                     0.02

Broadleaf Plants
                                      N/A
                                     0.02

Fruits/Pods/Seeds
                                      N/A
                                   <0.01

Arthropods
                                      N/A
                                     0.01
   [1] Avian acute RQs are based on the dietary LC50 for the bobwhite and mallard (>5050 mg a.i./kg-diet, MRID 44496607 and 44496608). Avian chronic RQs are based on the avian reproductive NOAEC for the bobwhite (320 mg/kg-diet, MRID 44496609).
   [2] Mammalian acute RQs are were not calculated because no acute dietary LC50 was available. Mammalian chronic RQs are based on the two-generation reproduction NOAEC for the laboratory rat (50 mg a.i./kg-diet, MRID 44496710).
   
   [3] RQ could not be calculated because acute dietary toxicity data are not available for mammals. 

The acute contact toxicity value for honeybees is >200 ug/bee, which is practically non-toxic. Risk estimations for terrestrial invertebrates are not routinely conducted. Based on the low acute contact toxicity study to honeybees, acute risk to adult terrestrial insects is expected to be low. However, additional data are needed for the EPA to conduct a complete risk assessment for potential adverse effects to honey bees and other insect pollinators. Because bees are attracted to the blooms of legume crops, bees may be exposed to nectar and pollen of the crops of this new use. Therefore, a honeybee acute oral toxicity study is needed to assess risk from oral exposure. Also, chronic toxicity studies with adult and larval bees are needed to assess the risk of lethal and sublethal effects from chronic exposure to trifloxystrobin. 

Table 18 provides RQs for non-target plants for the proposed new uses on chickpeas, dry peas, and lentils. For both aerial and ground applications, all RQs calculated for non-listed terrestrial plants were less than 0.1. These RQs were less than one-tenth the LOC for listed terrestrial plants, and thus indicate minimal risk to all non-target plants. RQs for listed species of terrestrial plants could not be calculated because phytotoxicity tests failed to obtain either a NOAEL or an EC05 for terrestrial plants. In the Tier I phytotoxicity test with trifloxystrobin, exposure to plants at 0.25 lb a.i./A did not have any more than a 13% inhibitory effect on any plant tested. The maximum seasonal application rate for the proposed new uses is approximately equal to the exposure rate used in this limit test. Therefore, while the risk to terrestrial plants appears to be low, possible adverse effects to listed species of terrestrial plants cannot be discounted.

Table 18. RQs for Plants in Dry and Semi-aquatic Areas Exposed to Trifloxystrobin TTR through Runoff and/or Spray Drift.
                                 Use Scenario
                                  Plant Type
                                 Listed Status
                                      Dry
                                 Semi-Aquatic
                                  Spray Drift
              Aerial Application on Chickpea, Dry Peas, or Lentil
                                    Monocot
                                  Non-listed
                                    <0.1
                                    <0.1
                                    <0.1
                                       
                                       
                                    Listed
                                    N/A[1]
                                      N/A
                                      N/A
                                       
                                       
                                     Dicot
                                  Non-listed
                                    <0.1
                                    <0.1
                                    <0.1
                                       
                                       
                                    Listed
                                      N/A
                                      N/A
                                      N/A
                                       
              Ground Application on Chickpea, Dry Peas, or Lentil
                                    Monocot
                                  Non-listed
                                    <0.1
                                    <0.1
                                    <0.1
                                       
                                       
                                       
                                    Listed
                                      N/A
                                      N/A
                                      N/A
                                       
                                       
                                     Dicot
                                  Non-listed
                                    <0.1
                                    <0.1
                                    <0.1
                                       
                                       
                                       
                                    Listed
                                      N/A
                                      N/A
                                      N/A
                                       
[1] RQs are not available for listed species because phytotoxicity studies with trifloxystrobin failed to establish an NOAEC.

Incident Reports

On 4 August 2014, the Ecological Incident Information System (EIIS, v. 2.1), Incident Data System (IDS), and Avian Incident Monitoring System (AIMS) were queried for ecological incidents involving exposure to trifloxystrobin. The EIIS database contains 28 incidents that were associated with trifloxystrobin (Table 19). All of these incidents involved damage to plants that were directly treated with trifloxystrobin. All of the incidents had a certainty index of either "possible" or "probable." None of the incidents were associated with known misuse of trifloxystrobin. Except for incidents on ornamental plants, most of the incidents involved exposure to one or more pesticide other than trifloxystrobin, and thus the causal agent is uncertain. For ornamental plants, however, all but one of these involved exposure to only trifloxystrobin, providing stronger evidence that trifloxystrobin caused the plant damage. All of the ornamental plant incidents occurred in nurseries in Florida.

Table 19. Ecological Incidents Associated with the Use of Trifloxystrobin.
                                     Crop
      Number of Incidents Involving Trifloxystrobin and other Pesticides
                 Number of Incidents Involving Trifloxystrobin
Cereal
                                       1
                                       0
Corn
                                       4
                                       0
Grape
                                       1
                                       1
Ornamental Plants
                                       1
                                      10
Soybean
                                       2
                                       1
Wheat, spring
                                       5
                                       0
Wheat, winter
                                       1
                                       0
Tomato
                                       0
                                       1
Total
                                      15
                                      13

The Incident Data System (IDS) was also queried for aggregated incident reports that listed ecological incidents for products containing trifloxystrobin. Ten aggregated incident report were reported for minor plant damage incidents associated with products containing trifloxystrobin. The products involved in these incident reports included Stratego YLD (5), Stratego (3), and Gem 25WG (2). No aggregated incidents were reported for adverse effects to animals. Also, no avian incidents have been reported for trifloxystrobin in the AIMS database of the American Bird Conservancy.

Altogether, ecological incidents suggest that trifloxystrobin may cause adverse effects to plants that are sprayed directly. They do not provide evidence of risk to plants exposed by spray drift or runoff, or risk to non-target organisms other than plants.

Risk Description

Non-target Aquatic Animals and Plants

Aquatic Animals

Although trifloxystrobin is highly toxic to aquatic animals, the low application rate, low persistence, and low mobility in soils together work to limit aquatic exposure. Based on water modeling conducted with three different scenarios (Michigan beans, Washington beans, and California row crops), the combined aquatic residues of trifloxystrobin and its racemic isomers are not expected to reach levels where the risk would exceed the EPA's level of concern (LOC) for non-listed species. However, peak EECs for ground and aerial applications were high enough to result in RQs that exceed the listed species LOC for saltwater invertebrates, and peak EECs for aerial applications also exceeded the listed species LOC for freshwater fish. These acute aquatic risks are similar to those previously predicted for other registered uses of trifloxystrobin. Concentrations of trifloxystrobin and its racemic isomers did not reach toxic levels on a chronic basis.

Trifloxystrobin was found to be less toxic to aquatic plants than to aquatic animals. None of the RQs for aquatic plants exceeded the LOC for either non-listed or listed species. Therefore, risk to aquatic plants is not a concern.

Non-target Terrestrial Animals and Plants

Toxicity studies indicate that trifloxystrobin has low acute toxicity to all terrestrial animals tested. Because of this  low toxicity, combined with the relatively low application rate, the acute risk to terrestrial animals are predicted to be below the LOC for both listed and non-listed species. Because peak EECs did not exceed the NOAEC for chronic effects to birds or mammals, chronic RQs are less than one, indicating that chronic risk to terrestrial animals is not a concern.

The proposed new use of trifloxystrobin are expected to result in both contact and oral exposure to bees and other insect pollinators. Because the acute contact toxicity of trifloxystrobin to the honeybee is very low (LD50 > 200 ug a.i./bee) and the application rates of trifloxystrobin are low, acute risk to bees and other insect pollinators from contact exposure is assumed to be low. However, additional tier-1 honey bee toxicity studies are needed for EFED to conduct a complete tier-1 risk assessment for insect pollinators. The additional honey bee studies that are needed are listed below in the section on uncertainties.

Both the Tier I phytotoxicity tests and the incident data indicate that trifloxystrobin can cause some phytotoxicity to plants that receive full direct spray at the application rate. Tier I seedling emergence and vegetative vigor studies found that exposure of some plants at or near the maximal seasonal rate of 0.25 lb a.i./A resulted in inhibition of growth ranging from 7% to 13%. Incidents have also been reported that allege that crops have been damaged by direct application of trifloxystrobin. However, the risk assessment indicates that off-site exposure from spray drift and runoff is not expected to reach levels that are toxic to plants. RQs calculated for non-listed terrestrial plants were all below 0.1, well below the LOC of 1. Therefore, risk to non-listed terrestrial plants is not a concern. However, because some growth effects were observed in the Tier I phytotoxicity studies, and some incidents of plant damage have been reported, the possibility of adverse effects to listed plants cannot be excluded at this time.

Uncertainties
 
 The Registration Review Preliminary Problem Formulation completed for trifloxystrobin in 2013 requests the following ecotoxicity studies (DP405629):
 
   * Guideline 850.4500, Aquatic Algae Growth and Reproduction, Tier II (The guideline is satisfied for freshwater green algae, but additional testing is needed with a freshwater diatom and a saltwater diatom.)
   * Guideline 850.4450, Cyanobacteria Toxicity with Anabaena flos-aquae (bluegreen algae) 
   * Guideline 850.4100, Terrestrial Plant Toxicity, Seedling Emergence Test
   * Guideline 850.4150, Terrestrial Plant Toxicity, Vegetative Vigor Test

Tier 1 honey bee toxicity studies are now also requested for assessing all new pesticide uses with potential exposure to insect pollinators. In addition to the honey bee acute contact toxicity study, which has already been submitted, the following studies are now needed to complete the tier-1 bee risk assessment:

   * A honey bee acute oral study (OECD 213)
   * A honey bee chronic oral toxicity study with adult bees
   * A honey bee chronic oral toxicity study with bee larvae.

Depending on the results of these studies, additional higher-tiered honey bee testing may be required.

For terrestrial plants, the EC25 is > 0.25 lb a.i./A. Using that value, the LOC for non-listed terrestrial plants would not be exceeded; however, neither a NOAEC nor an EC05 has been established for terrestrial plants. Therefore, there is uncertainty in whether there is or is not a hazard to threatened and endangered terrestrial plants. Since the data from the Tier I study are not sufficient for calculation of an EC05 nor determining a NOAEC, risk to endangered plant species cannot be assessed. Tier 2 phytotoxicity studies have been recommended in the recent Registration Review problem formulation for trifloxystrobin (D405269) to reduce this uncertainty and to support uses with application rates above 0.25 lb a.i./A. However, considering that the single application rate of the current new use is half of the application rate used in the terrestrial plant study mentioned above (MRID 44496723), significant adverse effects to listed terrestrial plants appear to be unlikely. 

REFERENCES

Burns, L. A.  2002.  EXAMS (Exposure Analysis Modeling System) Version 2.98.04.06.  Environmental Research Laboratory.  U. S. Environmental Protection Agency. Athens, GA.

Carsel et al.  1997.  PRZM (Pesticide Root Zone Model) Version 3.12.2  Environmental Research Laboratory.  U. S. Environmental Protection Agency. Athens, GA.

FAO 2000. Appendix 2. Parameters of pesticides that influence processes in the soil. In FAO Information Division Editorial Group (Ed.), Pesticide Disposal Series 8. Assessing Soil Contamination. A Reference Manual. Rome: Food & Agriculture Organization of the United Nations (FAO). http://www.fao.org/docrep/003/x2570e/x2570e00.htm 

Fletcher, J.S., J.E. Nellessen, and T.G. Pfleeger.  1994.  Literature review and evaluation of the EPA food-chain (Kenaga) nomogram, an instrument for estimating pesticide residues on plants.  Environ. Tox. Chem. 13:1383-1391.

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.

USEPA.  1998.  Guidelines for Ecological Risk Assessment.  Risk Assessment Forum, Office of Research and Development, Washington, D.C.  EPA/630/R-95/002F.  April 1998. http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=30759 

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

USEPA. 2006. User's Guide TerrPlant version 1.2.2.  December 2006.   United States Environmental Protection Agency. Environmental Fate and Effects Division.  Office of Pesticide Programs.

USEPA 2009a.  Guidance for Selecting Input Parameters in Modeling the Environmental Fate and Transport of Pesticides. Version 2.1 October 22, 2009.   http://www.epa.gov/oppefed1/models/water/input_guidance2_28_02.htm.   U.S. Environmental Protection Agency, Office of Pesticide Programs, Environmental Fate and Effects Division.  Arlington, VA.

USEPA 2009b.  DRAFT Guidance for Modeling Pesticides Total Toxic Residues (TTR) May 20, 2009.   U.S. Environmental Protection Agency, Office of Pesticide Programs, Environmental Fate and Effects Division.  Arlington, VA.

USEPA 2012a.  Guidance for Residues of Concern in Ecological Risk Assessment. December 20, 2012.  U.S. Environmental Protection Agency, Office of Pesticide Programs, Environmental Fate and Effects Division.  Arlington, VA.

USEPA 2012b.  NAFTA Guidance for Evaluating and Calculating Degradation Kinetics in Environmental Media.  December 17, 2012.  U.S. Environmental Protection Agency, Office of Pesticide Programs, Environmental Fate and Effects Division.  Arlington, VA.

USEPA 2012c.  Standard Operating Procedure for Using the NAFTA Guidance to Calculate Representative Half-life Values and Characterizing Pesticide Degradation.  November 30, 2012. U.S. Environmental Protection Agency, Office of Pesticide Programs, Environmental Fate and Effects Division.  Arlington, VA.

APPENDIX 1. SWCC Output File: Michigan Beans, Aerial Application

Variable Volume Water Model, SWCC Compatible Version
 
 *******************************************
Performed on:  7/22/2014  at 11: 2
 
Peak 1-in-10       =   1.08     ppb
Chronic 1-in-10    =  0.202E-01 ppb
Simulation Avg     =  0.184E-01 ppb
4-day avg 1-in-10  =  0.668     ppb
21-day avg 1-in-10 =  0.341     ppb
60-day avg 1-in-10 =  0.123     ppb
90-day avg 1-in-10 =  0.820E-01 ppb
 
Benthic Pore Water Peak 1-in-10       =  0.609E-01 ppb
Benthic Pore Water 21-day avg 1-in-10 =  0.433E-01 ppb
Benthic Conversion Factor             =   19.9     -Pore water (ug/L) to (total mass, ug)/(dry sed mass,kg)
Benthic Mass Fraction in Pore Water   =  0.186E-01
 
YEAR    Peak      4-day      21-day     60-day     90-day   Yearly Avg Benthic Pk  Benthic 21-day
  1    9.27E-01   6.04E-01   3.40E-01   1.23E-01   8.20E-02   2.02E-02   5.01E-02   3.11E-02
  2    1.39E+00   7.84E-01   3.37E-01   1.21E-01   8.05E-02   1.98E-02   1.30E-01   4.73E-02
  3    9.19E-01   5.71E-01   3.16E-01   1.13E-01   7.56E-02   1.86E-02   3.55E-02   2.58E-02
  4    9.03E-01   5.55E-01   3.08E-01   1.11E-01   7.40E-02   1.83E-02   5.37E-02   2.78E-02
  5    8.99E-01   5.44E-01   2.94E-01   1.05E-01   7.03E-02   1.73E-02   3.20E-02   2.44E-02
  6    9.43E-01   5.99E-01   3.41E-01   1.22E-01   8.17E-02   2.01E-02   4.01E-02   2.93E-02
  7    9.40E-01   5.89E-01   3.31E-01   1.18E-01   7.87E-02   1.94E-02   3.82E-02   2.75E-02
  8    9.29E-01   5.77E-01   3.26E-01   1.20E-01   7.97E-02   1.96E-02   3.70E-02   2.72E-02
  9    1.00E+00   6.73E-01   3.83E-01   1.40E-01   9.36E-02   2.31E-02   5.30E-02   4.43E-02
 10    9.01E-01   5.38E-01   2.88E-01   1.03E-01   6.85E-02   1.69E-02   3.09E-02   2.21E-02
 11    9.19E-01   5.79E-01   3.17E-01   1.14E-01   7.60E-02   1.87E-02   3.79E-02   2.63E-02
 12    8.96E-01   5.39E-01   2.89E-01   1.04E-01   6.92E-02   1.71E-02   3.50E-02   2.28E-02
 13    9.37E-01   5.89E-01   3.32E-01   1.18E-01   7.89E-02   1.95E-02   3.93E-02   2.90E-02
 14    9.17E-01   5.66E-01   3.11E-01   1.11E-01   7.42E-02   1.83E-02   3.39E-02   2.48E-02
 15    8.93E-01   5.23E-01   2.75E-01   9.89E-02   6.60E-02   1.63E-02   2.97E-02   2.17E-02
 16    9.15E-01   5.57E-01   3.03E-01   1.08E-01   7.21E-02   1.78E-02   3.32E-02   2.38E-02
 17    8.85E-01   5.17E-01   2.69E-01   9.68E-02   6.45E-02   1.59E-02   2.80E-02   1.99E-02
 18    8.92E-01   5.30E-01   2.79E-01   9.94E-02   6.63E-02   1.64E-02   3.09E-02   2.11E-02
 19    9.05E-01   5.59E-01   3.00E-01   1.09E-01   7.23E-02   1.78E-02   3.32E-02   2.36E-02
 20    9.12E-01   5.73E-01   3.10E-01   1.13E-01   7.55E-02   1.86E-02   3.49E-02   2.51E-02
 21    9.20E-01   5.75E-01   3.17E-01   1.13E-01   7.55E-02   1.86E-02   4.65E-02   2.73E-02
 22    1.09E+00   6.22E-01   2.97E-01   1.06E-01   7.08E-02   1.75E-02   6.17E-02   3.39E-02
 23    9.35E-01   6.04E-01   3.36E-01   1.22E-01   8.12E-02   2.00E-02   3.98E-02   2.86E-02
 24    9.31E-01   5.77E-01   3.23E-01   1.15E-01   7.68E-02   1.89E-02   3.68E-02   2.64E-02
 25    9.10E-01   5.63E-01   2.97E-01   1.07E-01   7.14E-02   1.76E-02   3.37E-02   2.36E-02
 26    1.43E+00   8.72E-01   3.80E-01   1.37E-01   9.12E-02   2.25E-02   9.93E-02   4.69E-02
 27    8.75E-01   4.88E-01   2.44E-01   8.64E-02   5.76E-02   1.42E-02   2.43E-02   1.62E-02
 28    8.90E-01   5.26E-01   2.73E-01   9.75E-02   6.50E-02   1.60E-02   2.90E-02   1.99E-02
 29    9.05E-01   5.40E-01   2.92E-01   1.05E-01   6.97E-02   1.72E-02   3.11E-02   2.28E-02
 30    9.22E-01   5.84E-01   3.21E-01   1.15E-01   7.65E-02   1.89E-02   4.04E-02   2.72E-02
****************************************************************************************************
 Effective compartment halflives averaged over simulation duration:
 
 zero washout                          0
 water col metab halflife (days) =      3.74860934970674     
 zero hydrolysis                       0
 photolysis halflife (days)  =          7704.75777615493     
 volatile halflife (days)  =            13967.9605636501     
 total water col halflife (days) =      3.74578164510793     
 
 zero burial                           0
 benthic metab halflife (days) =        5.47094337524768     
 zero benthic hydrolysis               0
 total benthic halflife (days) =        5.47094337524768     
 ***********************************************************************
 Fractional Contribution of Transport Processes to Waterbody & Total Mass (kg):
 
 Due to Runoff  =     0.0370          0.3917E-01
 Due to Erosion =     0.0112          0.1187E-01
 Due to Drift   =     0.9518           1.008    
 ***********************************************************************
 Flow in/out Characteristics of Waterbody:
 Average Daily Runoff Into Waterbody (m3/s) =   4.882614124166565E-004
 Baseflow Into Waterbody (m3/s)             =   0.000000000000000E+000
 Average Daily Flow Out of Waterbody (m3/s) =   4.882614124166484E-004
 ***********************************************************************
 Inputs:
   487.4     = oc partitioning coefficient
   1.480     = water column half Life
   25.00     = reference temp for water column degradation
   2.160     = benthic Half Life
   25.00     = Reference temp for benthic degradation
   2.000     = Q ten value
   54.70     = photolysis half life
   40.00     = reference latitude for photolysis study
   0.000     = hydrolysis half life
   408.4     = molecular wt
  0.2550E-07 = vapor pressure
  0.6100     = solubility
  0.1000E+06 = field area
  0.1000E+05 = water body area
   2.000     = initial depth
   2.000     = maximum depth
   2         1=vvwm, 2=usepa pond, 3 = usepa reservoir, 4 = const vol no flow, 5 = const vol w/flow 
 F  T = burial, else no burial
  0.1000E-07 = mass transfer coefficient 
  0.5000     = PRBEN
  0.5000E-01 = benthic compartment depth
  0.5000     = benthic porosity
   1.350     =  benthic bulk density
  0.4000E-01 = OC frcation in benthic sediment
   5.000     = DOC in benthic compartment
  0.6000E-02 = benthic biomass
   1.190     = DFAC
   30.00     = SS
  0.5000E-02 = chlorophyll
  0.4000E-01 = OC frcation in water column SS
   5.000     = DOC in water column
  0.4000     = biomass in water column
 FRACTION AREA CROPPED =    1.00000000000000     

APPENDIX 2. Output from T-REX Model for Trifloxystrobin

Upper Bound Kenaga Residues For RQ Calculation

                                                                 Chemical Name:
                                Trifloxystrobin
                                                                            Use
                       Dry Peas, chickpeas, and lentils
                                                                    Formulation
                                 All products
                                                              Application Rate 
                                                                           0.12
lbs a.i./acre
                                                                     Half-life 
                                                                             35
days 
                                                           Application Interval
                                                                             10
days
                                                           Maximum # Apps./Year
                                                                              2
 
                                                           Length of Simulation
                                                                              1
year
                                                    Variable application rates?
                                                                             no
 

Endpoints

Avian
                                                                  Mallard duck 
                                                                LD50 (mg/kg-bw)
                                    2000.00

                                                                Bobwhite quail 
                                                              LC50 (mg/kg-diet)
                                    5050.00

                                                                Bobwhite quail 
                                                                NOAEL(mg/kg-bw)
                                     0.00

                                                                Bobwhite quail 
                                                             NOAEC (mg/kg-diet)
                                    320.00
 
 
 
                                       
Mammals
                                                                LD50 (mg/kg-bw)
                                    5000.00

                                                              LC50 (mg/kg-diet)
                                     0.00

                                                               NOAEL (mg/kg-bw)
                                     75.00

                                                             NOAEC (mg/kg-diet)
                                    1500.00

Dietary-based EECs  (ppm)
                                    Kenaga

                                    Values
Short Grass 
                                     52.43
Tall Grass 
                                     24.03
Broadleaf plants
                                     29.49
Fruits/pods/seeds
                                     3.28
Arthropods
                                     20.53

Avian Results

                                     Avian
                                    Body   
                               Ingestion (Fdry)
                               Ingestion (Fwet)
                                  % body wgt
                                      FI
                                     Class
                                  Weight (g)
                                  (g bw/day)
                                    (g/day)
                                   consumed
                                 (kg-diet/day)
                                     Small
                                      20
                                       5
                                      23
                                      114
                                   2.28E-02
                                      Mid
                                      100
                                      13
                                      65
                                      65
                                   6.49E-02
                                     Large
                                     1000
                                      58
                                      291
                                      29
                                   2.91E-01
 
                                      20
                                       5
                                       5
                                      25
                                   5.06E-03
                                  Granivores
                                      100
                                      13
                                      14
                                      14
                                   1.44E-02
 
                                     1000
                                      58
                                      65
                                       6
                                   6.46E-02

                                 Avian Body   
                                 Adjusted LD50
                                  Weight (g)
                                  (mg/kg-bw)
                                      20
                                    1038.45
                                      100
                                    1322.00
                                     1000
                                    1867.37

Dose-based EECs   
(mg/kg-bw) 
                    Avian Classes and Body Weights (grams)

                                     small
                                      mid
                                     large

                                      20
                                      100
                                     1000
Short Grass 
                                     59.71
                                     34.05
                                     15.24
Tall Grass 
                                     27.37
                                     15.61
                                     6.99
Broadleaf plants
                                     33.59
                                     19.15
                                     8.57
Fruits/pods
                                     3.73
                                     2.13
                                     0.95
Arthropods
                                     23.39
                                     13.34
                                     5.97
Seeds
                                     0.83
                                     0.47
                                     0.21

Dose-based RQs         (Dose-based EEC/adjusted LD50)
                      Avian Acute RQs
Size Class (grams)

                                      20
                                      100
                                     1000
Short Grass
                                     0.06
                                     0.03
                                     0.01
Tall Grass
                                     0.03
                                     0.01
                                     0.00
Broadleaf plants
                                     0.03
                                     0.01
                                     0.00
Fruits/pods
                                     0.00
                                     0.00
                                     0.00
Arthropods
                                     0.02
                                     0.01
                                     0.00
Seeds
                                     0.00
                                     0.00
                                     0.00

Dietary-based RQs  (Dietary-based EEC/LC50 or NOAEC)
                                      RQs
 

 
                                     Acute
                                    Chronic
Short Grass 
                                     0.01
                                     0.16
Tall Grass 
                                     0.00
                                     0.08
Broadleaf plants
                                     0.01
                                     0.09
Fruits/pods/seeds
                                     0.00
                                     0.01
Arthropods
                                     0.00
                                     0.06

Note:  To provide risk management with the maximum possible information,
it is recommended that both the dose-based and concentration-based 
RQs be calculated when data are available

Mammalian Results

                                   Mammalian
                                    Body   
                               Ingestion (Fdry)
                               Ingestion  (Fwet)
                                  % body wgt
                                      FI
                                     Class
                                    Weight
                                  (g bwt/day)
                                    (g/day)
                                   consumed
                                 (kg-diet/day)
 
                                      15
                                       3
                                      14
                                      95
                                   1.43E-02
Herbivores/
                                      35
                                       5
                                      23
                                      66
                                   2.31E-02
insectivores
                                     1000
                                      31
                                      153
                                      15
                                   1.53E-01
 
                                      15
                                       3
                                       3
                                      21
                                   3.18E-03
Grainvores
                                      35
                                       5
                                       5
                                      15
                                   5.13E-03
 
                                     1000
                                      31
                                      34
                                       3
                                   3.40E-02

                                   Mammalian
                                    Body   
                                   Adjusted
                                   Adjusted
                                     Class
                                    Weight
                                     LD50
                                     NOAEL

 
                                      15
                                   10989.15
                                    164.84
Herbivores/
                                      35
                                    8891.40
                                    133.37
insectivores
                                     1000
                                    3845.80
                                     57.69
 
                                      15
                                   10989.15
                                    164.84
Granivores
                                      35
                                    8891.40
                                    133.37
 
                                     1000
                                    3845.80
                                     57.69

Dose-Based EECs 
(mg/kg-bw)
                       Mammalian Classes and Body weight

                                    (grams)

                                      15
                                      35
                                     1000
Short Grass 
                                     49.98
                                     34.55
                                     8.01
Tall Grass 
                                     22.91
                                     15.83
                                     3.67
Broadleaf plants
                                     28.12
                                     19.43
                                     4.51
Fruits/pods
                                     3.12
                                     2.16
                                     0.50
Arthropods
                                     19.58
                                     13.53
                                     3.14
Seeds
                                     0.69
                                     0.48
                                     0.11

Dose-based RQs
(Dose-based EEC/LD50 or NOAEL)
                                 Small mammal
                                 Medium mammal
                                 Large mammal

                                                                             15
grams
                                                                             35
grams
                                                                           1000
grams

                                     Acute
                                    Chronic
                                   Acute   
                                    Chronic
                                   Acute   
                                    Chronic
Short Grass 
                                     0.00
                                     0.30
                                     0.00
                                     0.26
                                     0.00
                                     0.14
Tall Grass
                                     0.00
                                     0.14
                                     0.00
                                     0.12
                                     0.00
                                     0.06
Broadleaf plants
                                     0.00
                                     0.17
                                     0.00
                                     0.15
                                     0.00
                                     0.08
Fruits/pods
                                     0.00
                                     0.02
                                     0.00
                                     0.02
                                     0.00
                                     0.01
Arthropods
                                     0.00
                                     0.12
                                     0.00
                                     0.10
                                     0.00
                                     0.05
Seeds
                                     0.00
                                     0.00
                                     0.00
                                     0.00
                                     0.00
                                     0.00

Dietary-based RQs  (Dietary-based EEC/LC50 or NOAEC)
                                  Mammal RQs

                                       
                                       

                                     Acute
                                    Chronic
Short Grass 
                                    #DIV/0!
                                     0.03
Tall Grass
                                    #DIV/0!
                                     0.02
Broadleaf plants
                                    #DIV/0!
                                     0.02
Fruits/pods/seeds
                                    #DIV/0!
                                     0.00
Arthropods
                                    #DIV/0!
                                     0.01

Note:  To provide risk management with the maximum possible information,
it is recommended that both the dose-based and concentration-based 
RQs be calculated when data are available

APPENDIX 3. Output from TERRPLANT Model for Trifloxystrobin

TerrPlant v. 1.2.2
 
 
 
 
Table 1. Chemical Identity.
 
                                 Chemical Name
Trifloxystrobin
 
                                    PC code
129112
 
                                      Use
Chickpeas, lentils, and dry peas
                                       
                              Application Method
Aerial
                                       
                               Application Form
Spray
                                        
                           Solubility in Water (ppm)
0.61
                                       
                                       
                                       
                                       
                                       
                                       
Table 2. Input parameters used to derive EECs.
 
                                Input Parameter
                                    Symbol
                                     Value
                                     Units
                                       
                               Application Rate
                                       A
                                     0.12
                                    lb ai/A
                                       
                                 Incorporation
                                       I
                                       1
                                     none
                                       
                                Runoff Fraction
                                       R
                                     0.01
                                     none
                                       
                                Drift Fraction
                                       D
                                     0.05
                                     none
                                       
 
 
 
 
 
Table 3. EECs for Trifloxystrobin.  Units in lb ai/A.
 
                                  Description
                                   Equation
                                      EEC
                                       
                              Runoff to dry areas
                                    (A/I)*R
                                    0.0012
                                       
                         Runoff to semi-aquatic areas
                                  (A/I)*R*10
                                     0.012
                                       
                                  Spray drift
                                      A*D
                                     0.006
                                       
                              Total for dry areas
                                ((A/I)*R)+(A*D)
                                    0.0072
                                       
                         Total for semi-aquatic areas
                              ((A/I)*R*10)+(A*D)
                                     0.018
                                       
 
 
 
 
 
Table 4. Plant survival and growth data used for RQ derivation. Units are in lb ai/A.
 
                              Seedling Emergence
                               Vegetative Vigor
                                  Plant type
                                     EC25
                                    NOAEC 
                                     EC25
                                    NOAEC 
                                    Monocot
                                     0.25
                                       x
                                     0.25
                                       x
                                     Dicot
                                     0.25
                                       x
                                     0.25
                                       x
 
                                       
                                       
                                       
                                       
Table 5. RQ values for plants in dry and semi-aquatic areas exposed to Trifloxystrobin through runoff and/or spray drift.*
                                  Plant Type
                                 Listed Status
                                     Dry 
                                 Semi-Aquatic
                                  Spray Drift
                                    Monocot
                                  non-listed
                                    <0.1
                                    <0.1
                                    <0.1
                                    Monocot
                                    listed
                                    #VALUE!
                                    #VALUE!
                                    #DIV/0!
                                     Dicot
                                  non-listed
                                    <0.1
                                    <0.1
                                    <0.1
                                     Dicot
                                    listed 
                                    #VALUE!
                                    #VALUE!
                                    #DIV/0!
*If RQ > 1.0, the LOC is exceeded, resulting in potential for risk to that plant group.