### UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON D

. C.
, 2 0 46 0



### MEMORANDUM PC Code : 121301 DP Barcode : 412033 

### March 26, 2014

Subject:

To:

From:

Through: Environmental Fate and Effects Division's Response to Public Comments on the Registration Review Preliminary Risk Assessment for Cyromazine

James Parker, Chemical Review Manager Thomas Moriarty, Team Leader Neil Anderson, Branch Chief Risk Management and Implementation Branch I Pesticide Re

- evaluation Division (7508P) 

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Amy Blankinship, M

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James Hetrick, Ph.D., Senior Science Adviso 8tJII1Ul 

# {J. f:(.f/tA.f; Environmental Risk Branch III Environmental Fate and Effects Division (7507P)

This document contains the Environmental Fate and Effects Division's (EFED's) responses to comments received on the Cyromazine Registration Review Preliminary Risk Assessment (EPAHQ-OPP-2006-0108). Only Syngenta Crop Protection, LLC provided comments on the ecological risk assessment. Based on these comments and a reanalysis of the data, EFED has updated the risk assessment conclusions. The table below summarizes the risk conclusions for direct effects to l isted species

. Based on the reanalysis of the data, the levels of concern are no longer exceeded for acute and chronic exposure to avian or mammalian taxa for any foliarapplied crop, except for potatoes for birds

. Additionally, potential chronic risk to aquatic invertebrates is anticipated to be low

.Listed Plant TaxonPotential Direct EffectsTerrestrial and semiaquatic plants –monocots and dicotsUncertain- Phytotoxicity reported (nature of plant injury unknown). Runoff EECs to semi-aquatic areas, but not to dry areas, greaterthan reported toxicity levels, so potential effects may be spatially limited. For spray drift exposure, potential direct effects tomonocots (via ground and aerial application) and for ground application to dicots the likelihood of effects is anticipated to be low;there may be potential direct effects todicots from aerial application in a spatially limited area from aerial application topotatoes(EECs≥toxicity values for≤72 feet off-field)Aquatic plantsNo effectListed Animal TaxonPotential Direct EffectsAcuteNotesChronicNotesTerrestrial invertebrates Yes1Potential direct effects to birds andmammals from onion seed use.For foliar application to all crops, exceptpotato, acute avian (surrogates for reptilesand terrestrial-phaseamphibians) andmammalian RQ values were less thanLOCUncertain for foliar application topotatoes, as screening-level RQ valueswould not exceed the acute LOC for birds(also surrogate for reptiles and terrestrialamphibians) if the application scenariowere modified byreducing the totalnumber of applications from 3 to 2.For foliar applications to potatoes, forreptiles and amphibians, RQs did notexceed LOC (except for animalsconsuming herbivorous mammals) usingmodel default diet assumptions; howeverreptiles and amphibian diets expected tovary between species and this conclusionYes2Potential direct effects to birds andmammals from onion seed use.For foliar application to all crops,except potato,chronic avian(surrogates for reptiles and terrestrialphase amphibians) and mammalianRQ values were less than LOC.Uncertain for foliar application topotatoes, as screening-level RQvalues would not exceed the chronicLOC for birds (also surrogate forreptiles and terrestrial amphibians) ifthe application scenario weremodified byreducing the totalnumber of applications from 3 to1.Chronic exposure not determined forsoil amendment use.3Based on the estimated water concentrationsMammalsSee footnote1See footnote2BirdsSee footnote1See footnote2ReptilesSee footnote1See footnote2AmphibiansSee footnote1See footnote2Freshwater fish Noeffect NoeffectFreshwater invertebrates No effectNoeffect3Molluscs NoeffectNDEstuarine/marine fish No effectNoeffectListed Plant TaxonPotential Direct EffectsEstuarine/marineinvertebratesNo effectmay not apply across all species. If applymodified application scenarios above, thenscreening-level RQ values would notexceed the acute LOC.No effect for amending soil withcyromazine-treated manure use.No effect3and toxicity values for crustaceans andmidges, the RQs did not exceed the LOC, soeffects may be limited. A species in theColeoptera order (beetles) is another targetedpest, and while potential direct effects toaquatic invertebrates in the Coleoptera orderand other orders not mentioned is unknown,there were effects reported for larvae interrestrial Coleoptera beetles. At this time,there are other listed aquatic invertebratesincluding Coleoptera beetles and a dragonfly.Based on the reported geographic areas ofcyromazine use, the potential for direct effectsto other listed aquatic invertebrates (beetlesand dragonfly), is uncertain. However, basedon the available toxicity data and the EECs,species in these orders would need to be fouror more times more sensitive than theavailable species. Therefore, chronic risk toaquatic invertebrates is likely to be low.

## 1. Syngenta Crop Protection Comment: Page 9, Section 1. Executive Summary, B. Nature of Stressor
Syngenta disagrees with EPA’s description on the persistence of cyromazine in soil. The Agency stated that cyromazine is persistent in soil because the half-lives are greater than 100 days. Syngenta stated that the half-lives of cyromazine in soil range from 62 to 142 days. This range of half-lives is classified as slightly degradable (t 1/2 

## = 60 to 180 days) according to the FAO defi nition for degradability in soil.

EFED Response: EPA agrees that cyromazine is sli ghtly degradable in soil. An exact qualifier on the degradat ion potential of cyromazine in soil is subjective because it is dependent on numerous factors including soil type, half-life analysis, soil temperature, soil moisture, etc. EPA believes that cyromazine is moderately persistent to persistent in soil. Belo w is an analysis showing that the upper 90 th 

## confidence bound on the mean half-life can ra nge from 147 to 250 days. These data would suggest that cyromazine is slightly degradable to very slightly degradable according to the FAO classification. The e limination of the half -life in muck soil increases the upper 90 th 

## confidence bound on the mean half -life of cyromazine into the very slightly degradable FAO classification.

Table 1. Summary of Aerobi c Soil Metabolism Half-lives

Study Soil Type Soil Texture All Soils Mineral Soils 157458 Organic Sand-Muck 107 107 107
157458 Mineral Sandy Loam 142 142 142 142 142 142

43767901 Mineral Sandy Loam (Linear SFO) 62 62

43767901 Mineral Sandy Loam ( Nonlinear SFO) 27.3 27.3

43767901 Mineral Sandy Loam (DFOP) 37.1 37.1

Mean 103.67 95.37 92.1 89.55 102 84.65
Standard Deviation 40.10 53.41 58.78 74.18 56.57 81.11 90 th 

### Confidence Bound on the Mean 147.34 153.52 156.10 250.99 225.12 261.17



## 2. Syngenta Crop Protection Comment: Pages 26-27, Section 3. Environmental Fate Characterization and Mo deling Input Parameters
Syngenta stated that field dissi pation half-lives of cyromazi ne range from 83 to 236 days instead of the reported 93 to 240 days. Add itionally, the half-life for cyromazine in chicken manure should be 493 days (MRID 156483) . The registrant also believes that the mobility classification based on the FAO mo bility classification (moderately mobile to mobile) instead of a general statement of “generally less than 2”.

EFED Response : EPA agrees with the registrant th at the field dissipation half-lives for cyromazine range from 83 to 236 days, and the half-life of cyromazine in chicken manure

## 5 is 493 days. EPA agrees the FAO soil mobility classification is moderately mobile to mobile.

3. Syngenta Crop Protection Comment: Page 28, Table 5: Input Parameters in GENEEC and PE5 Modeling to Estimate Cyromazine Concentrations Resulting From the Uses on Crops, Ornamentals, and Soil Amendment (Manure and Feed –throughs, Mushroom Compost)
Syngenta is unable to validate the source of the single value soil metabolism half-life of 150 days used in GENEEC and PRZM/EXAMS modeling. Based on current model input parameter guidance, Syngenta believes the correct half-life for modeling is 147.38 days (90 th 

## percentile confidence bound on the mean half -life). This value was calculated using half-lives of 62 days, 142 days, and 107 days. Because of the recommended change in half-life and the absence of aerobic aqua tic metabolism data, the aerobic aquatic metabolism half-life should be 294.76 days (2 x 147.38 days). The anaerobic aquatic metabolism half-life should be 585.6 days (2 x 97.6 days x 3).
Syngenta stated that the K d 

## model is more appropriate for modeling because the coefficient of variation for K d 

## is less than the coeffi cient of variation for K oc 

## . Therefore, the modeling should be conducted on the mean K d 

## (2.25 ml/g) instead of the lowest K d 

## for a non-sand soil (3.9 ml/g). Syngenta stated that the K d 

## of 17 ml/g, as noted in footnote 3 in Table 5, is for an organic soil (22.9%). They recommend that this K d 

## should not be used in calculating the soil:wat er partitioning coefficient for cyromazine. Also, the registrant stated an incorrect soil te xture (silt loam) is reported for the soil with a K d 

## of 3.87 ml/g. The correct soil texture is loam.

EFED Response : EPA agrees with the model input issues raised by Syngenta except for the half-life of the anaerobic aquatic metabolism half-life. As per current EFED input parameter guidance, the soil metabolis m half-life should be 147.38 days (90 th 

## percentile confidence bound on the mean half-life of 62 days, 142 days, and 107 days) (http:/www.epa.gov/oppefed1/models/water /input_parameter_guidance.htm). Additionally, the aerobic aquatic metabolism half-life for cyromazine would be 294.76 day (147.38 days x 2). The lowest non-sand K d 

## (3.39 ml/g) for cyromazine should actually be the mean K d 

## for mineral soils (2.3 ml/g). EPA believes the anaerobic aquatic metabolism half-life should be 300 days (100 days x 3) because of the available data for a single soil in an an aerobic soil metabolism study (MRID 43767902). Table 2 below (Table 5 in the preliminary risk assessme nt) shows the revised model input table for GENEEC modeling. Table 3 (Table 6 in the preliminary ri sk assessment) shows that the revised model input parameters do not substa ntially alter the EECs as presented in the preliminary risk assessment.

## 6 Table 2. Input Parameters Used in GENEEC Mo deling to Estimate Cyromazine Concentrations Resulting From the Uses on Crops, Ornamentals, and Soil Amendment (Manure and Feed-throughs, Mushroom Compost) Input Parameter Value for Cyromazine Reference
Solubility in Water (mg/L at 25 o 

### C) 1.36 x 10 5 mg/L 

### MRID 43061200
Hydrolysis Half-life (t 1/2 

### at pH 7) Stable at pH 5, 7, and 9 MRID 103148
Aquatic Photolysis Half-life (days; t 1/2 

### at pH 7) Stable in water at pH 7 MRID 103149
Aerobic Soil Metabolism [upper 90 th 

### percentile confidence bound on the mean half-life value (t 1/2 

### ; days)] 147.3 MRIDs 157458, 43767901 Aerobic Aquatic Metabolism Hal f-life [water column; upper 90 th 

### percentile confidence bound on the mean half-life value (t 1/2 

### ; days)] 147.3 days x 2 = 294.6 days EFED Input Parameter Guidance

Average Adsorption Rate Coefficient (K ads 

### ; mL/g) Average K d 

### = 2.3 MRIDs 103139, 103150, 103165 1 The 90 th percent upper bound of mean of 107, 142, 62 days is 147.3 days (http:/www.epa.gov/oppefed1/models ater/input_parameter_guidance.htm). 2 K ads 0.52 (sand), 2.37 (sandy clay loam), 3.87 ( loam). The K d from an organic soil ( 17 ml/g) was excluded because it has an extremely high soil organic matter content (SOM= 22%)



### Table 3. Comparison of Tier I Surface Water for Cyromazine EECs for Registered Crop Uses for the Original Input Parameters and Revised Input Parameters


## . Crops Application Information Estimated Environmental Concentrations (μg/L) Application Rate (lbs ai/A) Number of Applications Seasonal Application Rate (lbs ai/A) Peak 21-Day Average 60-Day Average

Original

EEC Revised EEC Original EEC Revised EEC Original EEC Revised EEC Lima beans, dried beans, hanover salad, bulb vegetables, cucurbit, brassica leafy, celery, head lettuce, peppers, abyssinian seakale cabbage, turnip greens, tomatoes, 0.125 6 0.75 29.95 32.44 29.23 31.79 27.9 30.55

Leafy vegetables (minus brassica leafy, celery, head lettuce) 0.125 5 0.625 25.09 27.34 24.49 26.86 23.37 25.82

Potatoes (Colorado potato beetle and leafminer) 0.249 3 0.747 30.3 33.72 29.57 33.04 28.23 31.75

## 7 4. Syngenta Crop Protection Comment:


## The registrant could not replicate the PRZM/EXAMS modeling in Table 6 of the preliminary risk assessment.

EFED Response: EPA reran the PRZM/EXAMS modeling. Table 4 includes the revised input parameters for the PRZM/EXAM S modeling. As per current EFED input parameter guidance, the soil metabolism half-life was changed to 147.38 days (90 th 

## percentile confidence bound on the mean half-life of 62 days, 142 days, and 107 days) (http:/www.epa.gov/oppefed1/models/water /input_parameter_guidance.htm). Additionally, the aerobic aquatic metabolism half-life for cyromazine was changed to 294.76 day (147.38 days x 2). Addi tionally, The lowest non-sand K d 

## (3.39 ml/g) for cyromazine was changed to represent the mean K d 

## for mineral soils (2.3 ml/g). Also, the anaerobic aquatic metabolism half-life was changed to 300 days (100 days x 3) because of the available data for a single soil in an anaerobic soil metabolism study (MRID 43767902). Table 5 shows the 1 in 10 year sediment, pore water, and water column EECs. The PRZM/EXAMS input files are shown in Appendix A.

Table 4. Input Parameters Used in PRZM/EXAMS Modeling to Estimate Cyromazine Concentrations Resulting From the Potato Use Input Parameter (Symbol; Unit) Value for Cyromazine Reference

Molecular Weight 166.19 SRC Database(http://www.srcinc.com/what-wedo/databaseforms.aspx?id=386)

Henry’s constant (25 o 

### C) 5.65 x 10 -14 atm-m 3 / mole @ 25oC 

### SRC Database(http://www.srcinc.com/what-wedo/databaseforms.aspx?id=386)

Vapor Pressure (torr) 3.36 x 10 -9 torr @ 25oC 

### SRC Database(http://www.srcinc.com/what-wedo/databaseforms.aspx?id=386) Solubility in Water (mg/L at 25 o 

### C) 1.36 x 10 5 mg/L 

### MRID 43061200
Hydrolysis Half-life (t 1/2 

### at pH 7) Stable at pH 5, 7, and 9 MRID 103148 Aquatic Photolysis Half-life (days; t 1/2 

### at pH 7) Stable in water at pH 7 MRID 103149 Aerobic Soil Metabolism [upper 90 th 

### percentile confidence bound on the mean half-life value (t 1/2 

### ; days)] 147.3 MRIDs 157458, 43767901

Aerobic Aquatic Metabolism Half-life [water column; upper 90 th 

### percentile confidence bound on the mean half-life value (t 1/2 

### ; days)] 147.3 days x 2 = 294.6 days EFED Input Parameter Guidance

Anaerobic Aquatic Metabolism Half-life (t 1/2 

### ; days) 100 days X 3 = 300 EFED Input Parameter Guidance Anaerobic Soil Metabolism Half-life (t 1/2 

### ; days) 100 days MRID 43767902 Average Adsorption Rate Coefficient (K ads 

### ; mL/g) Average K d 

### = 2.3 MRIDs 103139, 103150, 103165

## 8 Table 5. PRZM/EXAMS Modeling to EECs for Cyromazine Resulting From the Potato Use

Crop Environmental Compartment Estimated Environmental Concentration (μg/L)

Peak 21-day average 60-day average

Potatoes (Colorado potato beetle and leafminer) Scenario: MEpotatoSTD 4 Application Date: June 1 st Water Column (ppb) 7.337 6.990 6.639

Pore Water (ppb) 5.086 5.075 5.016

Sediment (μg/kg) 13.325 13.295 13.143



## 5. Syngenta Crop Protection Comment, Cover Letter, Pg. 5 Line 12 to Pg. 6 : Syngenta supports the use of additional refinements, which should include the best available higher-tier risk assessment data and methodologies, when making final effect determinations for listed species.
EFED Response : EPA plans to address many of the concerns raised as part of the implementation plan for assessing the risks of pesticides to listed species based on the recommendations of the April 2013 National Academy of Sciences (NAS) report.
The NAS report, available at http://www.nap.edu/catalog.php?record_id=18344, outlines recommendations on specific scientific and tech nical issues related to the development of pesticide risk assessments that are compliant with the Endangered Species Act and the Federal Insecticide, Fungicide, and Rodenticid e Act. In November, the EPA, along with the U.S. Fish & Wildlife Service (USFWS), the Na tional Marine Fisheries Service (NMFS) (collectively, the Services), and the U.S. De partment of Agriculture (USDA), released a summary of their joint Interim Approaches for assessing risks to listed species from pesticides. The Interim Approaches were develo ped jointly by the Agencies in response to the NAS’ recommendations and reflect a common a pproach to risk assessment shared by the Agencies as a way of addressi ng scientific differences between EPA and the Services. The joint Interim Approaches were released prior to the stakeholder workshop held on November 15, 2013. EPA is presenting the joint Interim Approaches at the December 2013 PPDC and SFIREG meetings, allowing additional opportuni ties for stakeholders to comment on the Interim Approaches. The Agencies will consider public comments on the Interim Approaches prior to implementing them. The Agencies intend to jointly implement these approaches as part of a phased iterative proc ess. EPA will refine its listed species risk assessments based on these interim approaches. The details of the joint Interim Approaches are contained in the white paper “Interim Approaches for National-Level Pesticide Endangered Species Act Assessments Base d on the Recommendations of the National Academy of Sciences April 2013 Report,” dated November 1, 2013, available at http://www.epa.gov/espp/2013/nas.html

.

## 9 6. Syngenta Crop Protection Comment, Cover Letter Pg 4 and Section V, Pg. 57, Lines 1-15 : Syngenta agrees with EPA’s initial determination of “n o effects” on listed aquatic invertebrates. Syngenta provi ded a summary regarding thei r co-occurrence analyses for several listed aquatic invert ebrates, for which they stat e that potential exposure of cyromazine to those organisms is limited.
EFED Response : In the preliminary ri sk assessment for cyromazine (USEPA 2013), the preliminary determination for aquatic invertebra tes for potential direct effects from chronic exposure was reported as ‘no effect’. Howe ver, this preliminary determination was characterized in that chronic RQs were belo w the LOC using data from aquatic crustaceans but other data suggested that other aquatic invertebrates (par ticularly in the Diptera order) may be potentially affected by chronic exposure. Additionally, while data on aquatic species in the Coleoptera order were not available, da ta on terrestrial Coleopter a species also suggest potential direct effects. At the time of the assessment, there were no listed species in the Diptera order, but there were other listed aquatic invertebra tes including Coleoptera beetles and a dragonfly. According to the analysis in the risk assessment, based on the reported geographic areas of cyromazine us e, the potential for direct e ffects to other listed aquatic invertebrates (beetles and dr agonfly) may be limited, but this was uncertain. Further refinements to the preliminary risk assessmen t were conducted and results are presented in item #8 of this response.

7. Syngenta Crop Protection Comment, Pg 19-21, Table 4 : Several of the MRID numbers listed in the risk assessment appear to be incorrect, correct MRID numbers were provided.
EFED Response : The MRID numbers reported by Syngenta are correct. The risk assessment used accession numbers reported in the data evaluation records (DERs) and incorrectly labeled them as MRID numbers. However, the MRID for the mallard chronic reproduction study reported in th e risk assessment was correct.

8. Syngenta Crop Protection Comment, Pg. 20, Table 4 and Section III, Pg 36, Lines 30-33 : Based on the study report, the endpoint for the chronic estuarine/marine invertebrate study (MRID 48691501) should be changed to 0.25 mg a.i./L, based on 14- day male length, and the study should be upgraded to acceptable.
EFED Response : Upon review of the data, the EFED reviewer’s conclusion regarding 14- day male lengths differed from the study author . While the inhibition of length at all levels was rather small in magnitude (4 to 8% of control), there was a general dose-responsive decreasing trend for which all treatment groups we re statistically differe nt from the control. However, given the estimated environmental con centrations (EECs) (in the preliminary risk assessment) and the magnitude of effect observed for this endpoint compared to the control, the preliminary risk assessment concluded that the likelihood of adverse effects from chronic exposure of cyromazine to estuarine-marine inve rtebrates, particularly for crustaceans, was also predicted to be low.
Based on comments received for the preliminary risk assessment and adjustments to the model input parameters, aquatic EECs were reca lculated and the recalculated aquatic E ECs

## 10 are similar to the EECs in the preliminary assessment. In the preliminary assessment, the highest calculated overlying water concentratio n was greater than the NOAEC established in a chronic midge development test, therefore, it was determined that there was a potential for direct effects to sediment-dwelling organisms (such as in the Diptera order) from chronic exposure to cyromazine. However, after comp arison to the recalculate d value, the overlying water EEC (6.99 μ g a.i./L) is now 2 times lower than the reported NOAEC value (14.5 μ g a.i./L). Therefore, based on the available data, the prelimin ary conclusion of low likelihood of potential direct effects fr om chronic exposure may be applied to a broader group of aquatic invertebrates to include organisms in the Diptera order. The preliminary conclusion of “Based on the reported geogra phic areas of cyromazine use, th e potential for direct effects to other listed aquatic invert ebrates (beetles and dragonfly) is uncertain” remains true. However, based on the available acute and s ub-chronic data for aquatic crustaceans and midges, acute toxicity studies are classified as slightly to practica lly non-toxic (48-h EC/LC 50 

## values of 9.1 mg/L ( Daphnia ) to ≥ 88.7 mg a.i./L ( Daphnia magna and midges) and a 7-day LC 50 

## of 1.95 mg a.i./L for mysid shrimp). Based on this toxicity data and the re-calculated EECs (highest peak EEC = 33.7 μ g a.i./L for use of potato), ac ute toxicity values for other aquatic invertebrates would need be approxima tely three to fourteen times more sensitive than the currently available data to exceed the acute listed leve l of concern (LOC). Similarly for chronic exposure, based on the available aqua tic invertebrate chroni c toxicity data and EECs (highest peak EEC = 31.8 μ g a.i./L for use of potato), a chronic NOAEC toxicity value for other species of aquatic invertebrates (Daphnia magna NOAEC = 0.31 mg a.i./L) would need to be approximately 10 times lower than this chronic toxicity value for freshwater crustaceans. The chronic mysid shrimp st udy did not have a definitive NOAEC value (<0.13 mg a.i./L) which was based on a slight, but si gnificant, effect on ma le body length (4-8%); a significant effect on survival was also observe d with a NOAEC value of 1.14 mg a.i./L. The current highest EEC is approximately 4 times lower than the non-definitive value for the mysid shrimp, therefore other aquatic invertebra tes would need to be about four times more sensitive than mysids to exceed the chronic LO C. Based on these anal yses, potential acute and chronic risk to aquatic inverteb rates is anticipated to be low.

9. Syngenta Crop Protection Comment, Pg. 21, Table 4 and Section III, Pg. 38, Lines 14 and 15 : Syngenta supports a NOAEL of 1000 mg/kg-diet for the mammalian twogeneration study, based on reduced body we ights (MRID 00103197). However, they suggest basing the NOAEC on an empirically derived value using measured body weights, feed consumption and dietary c oncentrations. Raw data supporting these calculations were subsequen tly supplied by Syngenta.

EFED Response : This study was re-evaluated by the Health Effects Division (HED) and the data evaluation record (DER) for this study (MRID 00103197) was updated. Based on the updated DER, the most sensitive NOAEL wa s 1000 mg/kg-diet based on decreased body weights for both males and females in the F0 and F1 generations (or 50 mg/kg/day (ppm) using the default conversion of 1 ppm = 0.05 mg/kg or 70, 54.6, 84.5, 70.5 mg/kg/day for F0 males, F1 males, F0 females, F1 females, respectively, using actua l food consumption data and actual test material dietary concentrati ons). As there were reported effects on body weights for both males and females in the F0 and F1 groups, the lowest empirically derived NOAEL value (54.6 mg/kg/day) as well as the no minal value (1000 mg/kg-diet) were used as

## 11 the reported chronic mammalian toxicity value and used as the input value in the T-REX model to calculate chronic mammalian RQs.

10. Syngenta Crop Protection Comment, Sect ion III, Analysis 2, Pg. 31, Lines 5-7 : The use of a 35-day foliar dissipation half-life is overly conservative a nd suggests that the value can be refined.
EFED Response : In the preliminary risk assessment , an evaluation of the potential foliar dissipation half-life was discu ssed. Based on the available in formation, it appeared that cyromazine may dissipate on some types of fo liage (i.e., leafy vegetables which may be similar to the broadleaf plant category in T-RE X) with calculated half-lives generally less than 14 days with 7 days in some cases (b ased on magnitude of residue studies; MRID 41976301, Acc. 00150744). But the data also seemed to suggest that for some types of plants, cyromazine did not read ily dissipate during the course of the study (i.e., tomatoes, cucurbits; MRID 42255101, 42116001). Additionally, dissipation data for grasses were not available, therefore, there was uncertainty in the potential di ssipation rate for these other dietary groups, of which short gra ss results in the highest EECs.
Using the available data, a 90th upper conf idence limit foliar dissi pation half-life was calculated and determined to be 7 days. This va lue is based on magnitude of residue data for leafy vegetables (lettuce, celery, spinach), melons (cantaloupe, cucumber, honeydew melon, summer squash, watermelon), tomatoes and peppers (MRIDs 42116001, 47010701, 47011801, 41976301, and 42255101). The data showed that cyromazine did dissipate on leafy vegetables, but was more persistent on me lons and tomatoes. Data on grasses were not available. Therefore, the initial uncertainties in that the available data may not be appropriate for all dietary groups ( e.g., grasses) still remains. However, the foliar dissipation half-life value calculated from empirically derived data as opposed to a default value (35 days) was used to revise the terrestrial EECs and RQs using the model T-REX.

Terrestrial EECs and RQs were recalculated using the revised foliar dissipation half-life value (7 days) and the chronic mammalian NOA EL value (54.6 mg/kg/day). Other input values were based on the maximum use rates as reported by the labels (s ame as used in the preliminary assessment). The EECs and subsequent RQ values are presented in the tables below.

Table 6. Avian Dose-Based Cyromazine Upper Bound EEC Values for Various Crops

Application Rate (crop) Size Class (g) 1 Avian Dose-Based EECs (mg/kg-bw) Dietary Item
Short Grass Tall Grass Broadleaf plants Fruits/ pods Arthropods Seeds

0.125 lb a.i./A @ 6 apps/7-d interval (succulent beans; lima beans; dried beans; hanover salad; bulb veg; cucurbits; brassica leafy; celery, head lettuce; leafy veg; peppers; sea kale cabbage, turnip greens 20 67.27 30.83 37.84 4.20 26.35 0.93

100 38.36 17.58 21.58 2.40 15.02 0.53

1000 17.17 7.87 9.66 1.07 6.73 0.24

## 12 1 

### Adjusted LD 50 

### values (mg/kg-bw): 20 g – 1229; 100 g – 1565; 1000 g– 2210



## Table 7. Mammalian Dose-Based Cyromazine Upper Bound EEC Values for Various Crops

1 

### Adjusted LD 50 

### values (mg/kg-bw): 15 g – 2305; 35 g – 1865; 1000 g – 806.8; LD 50 

### values calculated using initial body weight – study reported range from 20-30 g (i ndividual values not reported), so used 25 grams in TREX. 2 

### Adjusted NOAEL values (mg/kg-bw): 15 g – 109.9; 35 g – 88.9; 1000 g –38.5 0.249 lb a.i./A @3 apps/7-d interval (potatoes) 20 119.11 54.59 67.00 7.44 46.65 1.65

100 67.92 31.13 38.20 4.24 26.60 0.94

1000 30.41 13.94 17.10 1.90 11.91 0.42

0.125 lb a.i./A @ 3 apps /7-d interval (repeat 3 apps @ 7-d interval 21-d after last of first 3 apps) (ornamentals) 20 61.66 28.26 34.68 3.85 24.15 0.86

100 35.16 16.12 19.78 2.20 13.77 0.49

1000 15.74 7.22 8.86 0.98 6.17 0.22

Application Rate (crop) Size Class (g) 1 Mammalian Dose-Based EECs (mg/kg-bw) Dietary Item

Short Grass Tall Grass Broadleaf plants Fruits/ pods Arthropods Seeds

0.125 lb a.i./A @ 6 apps/7-d interval (succulent beans; lima beans; dried beans; hanover salad; bulb veg; cucurbits; brassica leafy; celery, head lettuce; leafy veg; peppers; sea kale cabbage, turnip greens 15 56.31 25.81 31.68 3.52 22.06 0.78

35 38.92 17.84 21.89 2.43 15.24 0.54

1000 9.02 4.14 5.08 0.56 3.53 0.13

0.249 lb a.i./A @3 apps/7-d interval (potatoes) 15 99.71 45.70 56.09 6.23 39.05 1.38

35 68.91 31.58 38.76 4.31 26.99 0.96

1000 15.98 7.32 8.99 1.00 6.26 0.22

0.125 lb a.i./A @ 3 apps /7-d interval ( repeat 3 apps @ 7-d interval 21-d after last of first 3 apps) (ornamentals) 15 51.62 23.66 29.04 3.23 20.22 0.72

35 35.68 16.35 20.07 2.23 13.97 0.50

1000 8.27 3.79 4.65 0.52 3.24 0.11

## 13 Table 8. Dietary-Based Cyromazi ne EEC Values for Various Crops

Application Rate (crop) Dietary-Based EECs (mg/kg-diet) Dietary Item Short Grass Tall Grass Broadleaf plants Fruits/pods/seeds Arthropods 0.125 lb a.i./A @ 6 apps/7-d interval (succulent beans; lima beans; dried beans; hanover salad; bulb veg; cucurbits; brassica leafy; celery, head lettuce; leafy veg; peppers; sea kale cabbage, turnip greens 59.06 27.07 33.22 3.69 23.13

0.249 lb a.i./A @3 apps/7-d interval (potatoes) 104.58 47.93 58.83 6.54 40.96 0.125 lb a.i./A @ 3 apps /7-d interval (repeat 3 apps @ 7-d interval 21-d after last of first 3 apps) (ornamentals) 54.14 24.81 30.45 3.38 21.21



### Table 9. Avian Acute Dose-Based RQ Values for Foliar Application of Cyromazine. Application rate (crop) Functional Feeding Group Dietary Item 20 g bird 100 g bird 1000 g bird
Acute 1 Acute 1 Acute 1

0.125 lb a.i./A @ 6 apps/7-d interval (succulent beans; lima beans; dried beans; hanover salad; bulb veg; cucurbits; brassica leafy; celery, head lettuce; leafy veg; peppers; sea kale cabbage, turnip greens Herbivores/Insectivores
Short Grass 0.06 0.02 0.01
Tall Grass 0.03 0.01 <0.01 Broadleaf plants 0.03 0.01 <0.01 Fruits/pods <0.01 <0.01 <0.01

Arthropods 0.02 0.01 <0.01

Seeds <0.01 <0.01 <0.01

0.249 lb a.i./A @3 apps/7-d interval (potatoes) Herbivores/Insectivores
Short Grass 0.10 0.04 0.01
Tall Grass 0.04 0.02 0.01 Broadleaf plants 0.05 0.02 0.01 Fruits/pods 0.01 <0.01 <0.01 Arthropods 0.04 0.02 0.01

Seed <0.01 <0.01 <0.01

0.125 lb a.i./A @ 3 apps /7-d interval (repeat 3 apps @ 7-d interval 21-d after last of first 3 apps) (ornamentals) Herbivores/Insectivores
Short Grass 0.05 0.02 0.01
Tall Grass 0.02 0.01 <0.01 Broadleaf plants 0.03 0.01 <0.01 Fruits/pods <0.01 <0.01 <0.01 Arthropods 0.02 0.01 <0.01

Seeds <0.01 <0.01 <0.01

## 14 Application rate (crop) Functional Feeding Group Dietary Item 20 g bird 100 g bird 1000 g bird
Acute 1 Acute 1 Acute 1 Bolded RQ values exceed th e acute listed LOC of 0.1; 1 Acute RQ = (upper bound dose-based EEC, mg/kg-bw) / (LD 50 ; mg/kg-bw).

## 15 Table 10. Avian Chronic Dietary RQ values from Foliar Application of Cyromazine. Application Rate (Crop) Dietary Item Chronic RQ 1

0.125 lb a.i./A @ 6 apps/7-d interval (succulent beans; lima beans; dried beans; hanover salad; bulb veg; cucurbits; brassica leafy; celery, head lettuce; leafy veg; peppers; sea kale cabbage, turnip greens Short Grass 0.20
Tall Grass 0.09 Broadleaf plants 0.11 Fruits/pods/seeds 0.01 Arthropods 0.08

0.249 lb a.i./A @3 apps/7-d interval (potatoes) Short Grass 1.39
Tall Grass 0.64 Broadleaf plants 0.78 Fruits/pods/seeds 0.09 Arthropods 0.55

0.125 lb a.i./A @ 3 apps /7-d interval (repeat 3 apps @ 7-d interval 21-d after last of first 3 apps) (ornamentals) Short Grass 0.72
Tall Grass 0.33 Broadleaf plants 0.41 Fruits/pods/seeds 0.05 Arthropods 0.28
Bold values exceed the chronic LOC of 1.0 1 Chronic RQ = (EEC, mg/kg-diet) / chronic NOAEC, mg/ kg-diet; where the chronic NOAEC is 75 mg/kg-diet



### Table 11. Mammalian Acute RQ Values for Foliar Application to Potatoes of Cyromazine Application Rate (Crop) Functional Feeding Group Dietary Item 15 g mammals 35 g mammals 1000 g mammals

Acute 1 Acute 1 Acute 1

0.249 lb a.i./A @3 apps/7-d interval (potatoes) Herbivores/Insectivores

Short Grass 0.04 0.04 0.02
Tall Grass 0.02 0.02 0.01 Broadleaf plants 0.02 0.02 0.01 Fruits/pods <0.01 <0.01 <0.01 Arthropods 0.02 0.01 0.01
Seeds <0.01 <0.01 <0.01

1 Acute RQ = (upper bound dose-ba sed EEC, mg/kg-bw) / (LD 50 ; mg/kg-bw).

## 16 Table 12. Mammalian Chronic Dose-based RQ values for Foliar Application of Cyromazine Application Rate (Crop) Functional Feeding Group Dietary Item 15 g mammals 35 g mammals 1000 g mammals
Chronic 1 Chronic 1 Chronic 1

0.125 lb a.i./A @ 6 apps/7-d interval (succulent beans; lima beans; dried beans; hanover salad; bulb veg; cucurbits; brassica leafy; celery, head lettuce; leafy veg; peppers; sea kale cabbage, turnip greens Herbivores/Insectivores

Short Grass 0.47 0.40 0.21
Tall Grass 0.22 0.18 0.10 Broadleaf plants 0.26 0.23 0.12 Fruits/pods 0.03 0.03 0.01 Arthropods 0.18 0.16 0.08
Seeds 0.01 0.01 <0.01

0.249 lb a.i./A @3 apps/7-d interval (potatoes) Herbivores/Insectivores
Short Grass 0.83 0.71 0.38
Tall Grass 0.38 0.33 0.17 Broadleaf plants 0.47 0.40 0.21 Fruits/pods 0.05 0.04 0.02 Arthropods 0.33 0.28 0.15
Seeds 0.01 0.01 0.01

0.125 lb a.i./A @ 3 apps /7-d interval (repeat 3 apps @ 7-d interval 21-d after last of first 3 apps) (ornamentals) Herbivores/Insectivores

Short Grass 0.43 0.37 0.20
Tall Grass 0.20 0.17 0.09 Broadleaf plants 0.24 0.21 0.11 Fruits/pods 0.03 0.02 0.01 Arthropods 0.17 0.14 0.08

Seeds 0.01 0.01 <0.01 Bold values exceed the chronic LOC of 1 1 Chronic RQ = (upper bound dose-based EEC, mg/kg-bw) / (NOAEC; mg/kg-bw).



### Table 13. Mammalian Chronic Diet ary-based RQ values for Foliar Application to Potatoes for Cyromazine Application Rate (Crop) Dietary Item Chronic RQ 1

0.249 lb a.i./A @3 apps/7-d interval (potatoes) Short Grass 0.10
Tall Grass 0.05 Broadleaf plants 0.06 Fruits/pods/seeds 0.01 Arthropods 0.04

1 Chronic RQ = (EEC, mg/kg-diet) / chronic NOAEC, mg/ kg-diet; where the chronic NOAEC is 1000 mg/kg-diet

## 17 Table 13. Amphibian/Reptile Acute Dose-based RQ values for Foliar Application to Potatoes for Cyromazine

Dose-based RQs (Dose-based EEC/adjusted LD 50 ) Amphibian/Reptile Acute RQs for Small, Medium, and Large Species (grams)

2 20 200 Short Grass 0.00 0.00 0.00 Tall Grass 0.00 0.00 0.00 Broadleaf plants/sm insects 0.00 0.00 0.00 Fruits/pods/seeds/lg insects 0.00 0.00 0.00 Herbivore mammals 0.14 0.06 0.02 Insectivore mammals 0.01 0.00 0.00 Terrestrial phase amphibian 0.00 0.00 0.00



### Table 14. Amphibian/Reptile Dietary based Acute a nd Chronic RQ values for Foliar Application to Potatoes for Cyromazine

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

Acute Chronic
Short Grass 0.02 1.39 Tall Grass 0.01 0.64 Broadleaf plants/sm Insects 0.01 0.78 Fruits/pods/seeds/lg insects 0.00 0.09 Herbivore mammals 0.01 1.07 Insectivore mammals 0.00 0.07 Terrestrial phase amphibian 0.00 0.02



## Using these revised input values, for all uses ex cept for potato, there are no acute listed or non-listed avian or mammalian LOC exceedances or avian or mammalian chronic LOC exceedances. For potatoes, there are no LOC ex ceedances for mammals, but the acute listed LOC was exceeded for small birds consuming short grass (RQ = 0.10). Also, the avian chronic LOC was exceeded for birds consumi ng short grass (RQ=1.39). Additionally, using the revised foliar dissipation half-life and the T-HERPs m odel with the default input parameters, there are no LOC exceedances for th e foliar uses, except for potatoes. For the potato use, the acute listed LOC is exceeded for terrestrial-phase amphibians and reptiles consuming herbivorous mammals, and the chronic LOC is exceeded for terrestrial-phase amphibians and reptiles consuming short grass or herbivorous mammals. However, as THERPs has specific input parameters regardi ng diet and reptile and amphibian diets are expected to vary between species, this c onclusion may not apply across all species.
According to the data compiled by the Biologi cal and Economic Analys is Division (BEAD) (D387940), regarding use of cyromazine, it appear s that the average single foliar application rate for many crops is similar to the maximum single application rate on the label (reported average rate is 0.1 lb a.i./A, whereas the maxi mum label rate is 0.125 lb a.i./A). However,

## 18 where the label allows for a maximum of 6 a pplications, based on the compiled data from BEAD, it appears that the number of applications range from 1-2 with up to 3 for onions.
Use data were not available for foliar use on pot atoes. In the preliminary assessment, there are LOC exceedances for birds for the potato use. Based on the available BEAD data for the other foliar uses, the actual single applica tion rate for potatoes may be similar to the maximum label rate (0.249 lb a. i./A), however, the number of applicatio ns actually applied may be lower than the label maximum number of applications allowed (up to 3 applications). A reduction to two applications for potatoes would reduce the acute avian RQ below the LOC and a reduction to only one application pe r year would reduce the chronic avian RQ below the LOC. The foliar dissipation half-life would need to be 3 days or less for the RQs to be below the LOC, and the availabl e data do not support this value.
Based on the usage data in Table 2 in the preliminary risk assessment, potatoes are not listed. This may suggest that the use of cyromazine on potatoes may be limited in amount applied. Figure 2 in the preliminary risk assessment illu strates that the geographical areas with higher cyromazine use are in California, southern Te xas and Florida and part of New York. Based on available information, Florida produces less than 2% of the annual potato supply, but onethird of the winter/spring crop 1 

## . Other information states that potato cultivation in New York accounts for 1.7% of the U.S. production w ith potatoes planted across several places in the state 2 

## . Other information reported th at in 2011, 36,900, 36,400, 19,100 and 16,500 acres were planted in California, Florid a, Texas and New York, respectively 3



## . When modeling the exposure scenario for the po tato foliar uses, the EECs (short grass) are greater than the avian NOAEC for a period of about 2 weeks for which the EECs do drop below the NOAEC for a short period prior to the next and final application (Figure 1). The EECs are not greater than the reported LOAEC of 300 mg/kg for birds. As stated in the preliminary assessment, the avian study that wa s used in this assessment to calculate RQs was not designed to evaluate how long the pare ntal birds must be c onsuming dietary-items containing the chemical before effects on re production are observed. These studies are designed to allow the birds to consume treat ed feed for many weeks to allow time for equilibrium of the chemical within the bird a nd for the potential mate rnal transfer of the chemical to the eggs. As previously stated in the preliminary risk assessment, information suggests that cyromazine should equilibrate rela tively quickly within an animal. Based on a metabolism study in poultry in which the birds were fed cyromazine-treated feed daily (at the maximum labeled rate), cyromazine is excreted primarily as parent at concentrations essentially equivalent to or gr eater than the concentration in the feed. Once cyromazine was removed from the feed, the cyromazine concentr ations in the excreta were below detection limits by Day 3 of depuration (MRID 44759202).

1 

### http://www.ipmcenters.org/CropProfiles/docs/FLpotatoes.pdf (access January 17, 2013)

2 

### http://www.ipmcenters.org/CropProfiles/docs/nypotatoes.pdf (accessed January 17, 2013) 3 

### http://usda01.library.cornell.edu/usda/current/Pota/Pota-09-20-2012.pdf (accessed January 17, 2013)

## 19 Figure 1. Terrestrial EECs and Chronic Avian NOAEC value (figure generated in T-REX)

In conclusion, the use of the revised foliar dissipation half-life and chronic mammalian twogeneration reproduction NOAEL resulted in RQ valu es that were less than the LOC for all foliar uses except for potatoes. Use data for potatoes, which could allow for further refinement of this use, is not available. Ther efore, based on the RQs, th ere still is uncertainty in the potential for direct effects to small lis ted birds consuming short grass and from chronic direct effects to birds consumi ng short grass. A reduction in the number of applications from a maximum of 3, as per the label, to only one would reduce the avian RQ values below the LOC.

11. Syngenta Crop Protection Comment: The seeding rate for treated onion seeds should be 2 -4 lb seed/A based on available data.
EFED Response: While the risk estimation was conducted using the default seeding rate of 75 lb seed/A, a characterization of the onion seed treatment use was provided using 4 lb seed/A which is the upper limit expressed by Syngenta. When using a seeding rate of 4 lb seed/A, and an application rate of 4.95 lb a.i./100 lb seed, the acute RQs are not exceeded based on the LD 50 

## /ft 2 

## method (method #2 in the assessment and TREX outputs) (RQs = 0.08 for birds and 0.06 for mammals). However, wh en assessing acute a nd chronic exposure on a dietary basis (the number of seeds necessary to exceed the LOC), this evaluation is independent of seeding rate in the field and th erefore, the acute and chronic RQs still exceed the LOC for both birds and mammals. The appli cation rate to the seeds would need to be 0.045 lb a.i. /100 lb seed to be below the acute listed avian LOC and would need to be 0.0075

## 20 lb a.i./100 lb seed to be below the avian chroni c LOC. The currently labeled rate is 4.95 lb a.i./100 lb seed.
In the preliminary risk assessment, an effo rt was undertaken to de termine the number of seeds a bird or mammal would need to consume to exceed either the listed or non-listed LOC. A seeding rate of 4 lb seed/A was used in this exercise; additionally, the available data suggested that the number of onion seeds in a pound ranged from 100,000 to 130,000. Upon review of the data, th e information provided in Table 27 in the preliminary risk assessment was not very clear, therefore, the data are re-presented below in Table 15. Based on the labeled seed treatment applica tion rate and available number of seeds in a pound, a small bird would need to consume 11-14 seeds to achieve the acute listed LOC (1/10th LD 50 

## ), whereas a small mammal would need to consume 15 - 20 seeds to achieve the acute listed LOC. Similarly, a small bird or mammal would need to consume 55-71 or 77-100 seeds to achieve the acute non-listed LOC (1/2 LD 50 

## ). In using a seeding rate of 4 lb seed/A, a small bird would need to glean all seeds planted in one square feet to achieve the acute listed LOC (1/10th LD 50 

## ) or six square feet to achiev e the acute non-listed LOC (1/2 LD 50 

## ) (Table 16). The area necessary to achieve the acute LOC for medium birds and mammals is 8 or 6 square feet, respectively, and is 75 ft 2 

## or greater for large birds and mammals. The gleaning area necessary to achieve the acute non-listed LO C for small birds and mammals is 6 and 16-17 ft 2 

## , respectively. These values assume that a ll planted seeds are available for consumption and are consumed by one bird within the nece ssary area (sufficient competition for food may decrease exposure). However, based on the anal ysis, it appears that there is still potential exposure and potential direct effects to small, and potentially medium, birds and mammals from acute exposure to cyrom azine treated onion seeds.

Table 15. Number of Cyromazine Treated On ion Seeds Consumed by Birds and Mammals Necessary to Reach the Non-listed and Listed Level of Concerns

Bird Mammal Number of seeds to reach the LOC of 0.5 or 0.1 (100,000 seed/lb seed) Number of seeds to reach the LOC of 0.5 or 0.1 (130,000 seeds/lb seed) Weight of assessed animal (kg) 0.02 0.015 Adjusted LD 50 , mg/kg-bw (based on 20 or 15g bird or mammal) 1229 2305 0.225 mg a.i/seed (based on 4.95 lb a.i./100 lb seed) 0.173 mg ai/seed

mg a.i. needed to achieve the LD 50 for animal of assessed weight 24.581 66.891 bird mammal bird mammal

mg a.i. needed to achieve the LOC of 0.5 (1/2 LD 50 ) for animal of assessed weight 12.291 33.445 55 77 71 100

mg a.i. needed to achieve the LOC of 0.1 (1/10th LD 50 ) for animal of assessed weight 2.458 6.689 11 15 14 20

## 21 Table 16. Number of Square Feet Gleaned of Cyromazine Treated Onion Seeds by Birds and Mammals Necessary to Reach the Non-listed and Listed Level of Concerns

4 lb seed/A seeding rate 100,000 seeds per lb seed 130,000 seeds per lb seed Animal Size Class bird mammal bird mammal Area in sq feet necessary to reach LOC

LOC 0.5 (non-listed) 6 17 6 16 Small (20g, bird; 15 g mammal) LOC 0.1 (listed) 1 2 1 2

LOC 0.5 39 31 38 30 Medium (100g bird; 35 g mammal) LOC 0.1 8 6 8 6

LOC 0.5 546 385 532 376 Large (1000g bird & mammal) LOC0.1 109 77 107 75



## 12. Syngenta Crop Protection Comment, Section 2, Pg. 69, Lines 1-12: Cyromazine is a systemic insecticide and complete coverage of vegetation is not required to maintain efficacy. Based on calculations using ASAE medium to coarse droplet size and a toxicity value of 0.033 lb a.i./A (dicot, soybean, seedling em ergence) or 0.268 lb a.i./A (monocot, corn, seedling emergence), the spra y drift EECs overlap th e toxicity values by 36.1 ft or less. For vegetative vigor toxi city values, the overlap is <20 ft for both monocots or dicots. Based on these calculations , effects to non-target plants would be spatially limited; additionally, cyromazine is used extensively as a seed treatment and effects to plants in the field are not expected.

EFED Response: In the preliminary risk assessment , as droplet size is not specified on the labels, spray drift EECs were calculat ed using AgDrift (v2.01), using the default droplet size, fine to medium, for aerial and th en using the user spec ified droplet size of fine to medium/coarse for ground. However, in the EFED guidance memo on modeling offsite deposition of pesticides via spray drift, the default droplet size for ground application should be very fine to fine (USEPA 2013). Therefore, the offsite deposition rates were recalculated using the defined default values (Table 17). For monocots, the overlap between EECs and toxici ty values was four feet or less and was 72 feet or less for dicots. In the preliminary assessment, EFED did recognize based on the analyses, that except for dicots exposed from aerial application to potatoes, any effect is anticipated to be spatially limited.

## 22 Table 17 Spray Drift (Terrestrial) Asse ssment for Terrestrial Plant Species No. of application and app. rate (lb a.i/.A) distance from edge of field % of application rate EEC (lb a.i./A) Dicot (SE) a 

### Monocot (SE) b 

### Monocot (VV) c 

### Spray Method

Terrestrial plants inhabiting a reas off-site of application area 1 @ 0.249 (potatoes) 0 feet 0.5 0.12 3.6 0.44 0.92 Aerial 1 @ 0.249 73 feet 0.13 0.032 0.97 0.12 0.25

1 @ 0.249 0 feet 1 0.27 8.2 1 2.1

Ground 1 @ 0.249 7 feet 0.35 0.088 2.7 0.33 0.68
1 @ 0.249 20 feet 0.05 0.0325 0.98 0.12 0.25

a 

### Based on reported phytotoxicity in dicot species, Glycine max , at 0.033 lb a.i./A in the seedling emergence test. Value represent ratio of dry area EEC by reported value for phytotoxicity

a 

### Based on reported phytotoxicity in monocot species, Zea mays , at 0.27 lb a.i./A in the seedling emergence test. Value represent ratio of dry area EEC by reported value for phytotoxicity Based on reported phytotoxicity in monocot species, Zea mays , at 0.13 lb a.i./A in the vegetative vigor test. Value represent ratio of dry area EEC by reported value for phytotoxicity Drift values based on: aerial - droplet size ASAE Fine to medium, ground – droplet size ASAE very fine to fine, high boom, 90 th 

### percentile



## 13. Syngenta Crop Protection Comment, Section 5, Pg. 72, Lines 11-13: The assumption that all the cyromazine is rem oved while planting treated seeds is overly conservative. Suggest that this expos ure estimate be refined for increased environmental relevance.
EFED Response: EFED agrees that this assumption is potentially conservative, but data regarding potential loss of cyromazine during seeding are not available. However, it is anticipated that exposure of cyromazine to non-target organisms through the labeled uses (foliar application, seed treatmen t, soil amendment) should be sufficient to adequately assess potential risk to non-target or ganisms. Exposure to abrade d dust may be of concern to terrestrial invertebrates thr ough direct contact to the dust. Cyromazine toxicity in invertebrates appears to be target ed to the larval stages of the organism, and therefore, direct contact to the dust would likely be due to a se ttling of the dust after it becomes airborne during the abrasion process. This type of cont act could also be expect ed from direct foliar application and exposure via spray drift, or from soil amendment with cyromazine-treated manure. Therefore, the labele d uses of cyromazine are antic ipated to adequately capture potential exposure routes to terrestrial i nvertebrates during the vulnerable windows of exposure.

## 23 Literature Cited

Brady, Donald. 2013. Guidance on Modeling Offsite Deposition of Pesticides via Spray Drift for Ecological and Drinking Water As sessments. US EPA/OCSPP Memorandum.

U.S. Environmental Protection Agency (USEPA). 2013. 

## Preliminary Ecological Risk Assessment for the Registration Review of Cyromazine . January 24, 2013. Docket No. http://www.regulations.gov/#!doc ketDetail;D=EPA-HQ-OPP-2006-0108

U.S. Environmental Protection Agency (USEPA). 2013. Guidance on Mo deling Offsite Deposition of Pesticides via Spray Drift for Ecological and Drinking Water Assessments. Environmental Fate and Effects Division. Office of Pesticide Programs. December 20, 2013.

## 24 Appendix 1. GEENEC, PRZM-EXAMS, T-REX, T-HERPS, AgDrift outputs.



# GENEEC MODEL OUTPUT

RUN No. 1 FOR cyromazine ON Lima bean * INPUT VALUES *

-------------------------------------------------------------------- RATE (#/AC) No.APPS & SOIL SOLUBIL APPL TYPE NO-SPRAY INCORP ONE(MULT) INTERVAL Kd (PPM ) (%DRIFT) ZONE(FT) (IN)

-------------------------------------------------------------------- .125( .692) 6 7 2.3******* AERL_B( 13.0) .0 .0

FIELD AND STANDARD POND HALFLIFE VALUES (DAYS)

-------------------------------------------------------------------- METABOLIC DAYS UNTIL HYDROLYSIS PHOTOLYSIS METABOLIC COMBINED (FIELD) RAIN/RUNOFF (POND) (POND-EFF) (POND) (POND)

-------------------------------------------------------------------- 147.30 2 N/A .00- .00 294.60 294.60

GENERIC EECs (IN MICROGRAMS/LITER (PPB)) Version 2.0 Aug 1, 2001

-------------------------------------------------------------------- PEAK MAX 4 DAY MAX 21 DAY MAX 60 DAY MAX 90 DAY GEEC AVG GEEC AVG GEEC AVG GEEC AVG GEEC

-------------------------------------------------------------------- 32.44 32.35 31.79 30.55 29.66

RUN No. 2 FOR Leafy Veg ON Leafy Veg * INPUT VALUES *

-------------------------------------------------------------------- RATE (#/AC) No.APPS & SOIL SOLUBIL APPL TYPE NO-SPRAY INCORP ONE(MULT) INTERVAL Kd (PPM ) (%DRIFT) ZONE(FT) (IN)

-------------------------------------------------------------------- .125( .586) 5 7 2.3******* AERL_B( 13.0) .0 .0

FIELD AND STANDARD POND HALFLIFE VALUES (DAYS)

-------------------------------------------------------------------- METABOLIC DAYS UNTIL HYDROLYSIS PHOTOLYSIS METABOLIC COMBINED (FIELD) RAIN/RUNOFF (POND) (POND-EFF) (POND) (POND)

-------------------------------------------------------------------- 147.30 2 N/A .00- .00 294.60 294.60

GENERIC EECs (IN MICROGRAMS/LITER (PPB)) Version 2.0 Aug 1, 2001

-------------------------------------------------------------------- PEAK MAX 4 DAY MAX 21 DAY MAX 60 DAY MAX 90 DAY GEEC AVG GEEC AVG GEEC AVG GEEC AVG GEEC

-------------------------------------------------------------------- 27.42 27.34 26.86 25.82 25.07

RUN No. 3 FOR cyromazine ON potato * INPUT VALUES *

-------------------------------------------------------------------- RATE (#/AC) No.APPS & SOIL SOLUBIL APPL TYPE NO-SPRAY INCORP ONE(MULT) INTERVAL Kd (PPM ) (%DRIFT) ZONE(FT) (IN)

-------------------------------------------------------------------- .249( .723) 3 7 2.3******* AERL_B( 13.0) .0 .0

## 25 FIELD AND STANDARD POND HALFLIFE VALUES (DAYS)

-------------------------------------------------------------------- METABOLIC DAYS UNTIL HYDROLYSIS PHOTOLYSIS METABOLIC COMBINED (FIELD) RAIN/RUNOFF (POND) (POND-EFF) (POND) (POND)

-------------------------------------------------------------------- 147.30 2 N/A .00- .00 294.60 294.60

GENERIC EECs (IN MICROGRAMS/LITER (PPB)) Version 2.0 Aug 1, 2001

-------------------------------------------------------------------- PEAK MAX 4 DAY MAX 21 DAY MAX 60 DAY MAX 90 DAY GEEC AVG GEEC AVG GEEC AVG GEEC AVG GEEC

-------------------------------------------------------------------- 33.72 33.62 33.04 31.75 30.82



# APPENDIX

PRZM MODEL OUTPUT

MePotato; 8/05/02 "Maine Potato, MLRA 146, Modified from MEPOTIR1.inp from F Drive; Metfile: W14607.dvf (old: Met146.met), *** Record 3: 0.8 0.36 0 12.5 1 3 *** Record 6 -- ERFLAG 4 *** Record 7: 0.28 1.34 1 10 3 6 356.8 *** Record 8 1 *** Record 9 1 0.1 60 40 3 89 86 89 0 30 *** Record 9a-e 1 28 0106 1606 0107 1607 0108 1608 0109 1609 0110 0510 1610 0111 1611 0112 1612 0101 .788 .645 .400 .310 .173 .056 .053 .135 .267 .511 .544 .570 .586 .591 .593 .593 .014 .014 .014 .014 .014 .014 .014 .014 .014 .014 .014 .014 .014 .014 .014 .014 86 86 86 86 86 86 86 86 86 89 89 89 89 89 89 89 1601 0102 1602 0103 1603 0104 1604 0105 0505 1505 1605 2005 .592 .591 .590 .589 .594 .604 .623 .640 .631 .758 .762 .801 .014 .014 .014 .014 .014 .014 .014 .014 .014 .014 .014 .014 89 89 89 89 89 89 89 89 89 89 89 89 *** Record 10 -- NCPDS, the number of cropping periods 30 *** Record 11 010661 011061 051061 1 010662 011062 051062 1 010663 011063 051063 1 010664 011064 051064 1 010665 011065 051065 1 010666 011066 051066 1 010667 011067 051067 1 010668 011068 051068 1 010669 011069 051069 1 010670 011070 051070 1 010671 011071 051071 1 010672 011072 051072 1 010673 011073 051073 1

## 26 010674 011074 051074 1 010675 011075 051075 1 010676 011076 051076 1 010677 011077 051077 1 010678 011078 051078 1 010679 011079 051079 1 010680 011080 051080 1 010681 011081 051081 1 010682 011082 051082 1 010683 011083 051083 1 010684 011084 051084 1 010685 011085 051085 1 010686 011086 051086 1 010687 011087 051087 1 010688 011088 051088 1 010689 011089 051089 1 010690 011090 051090 1 *** Record 12 -- PTITLE Cyromazine - 3 applications @ 0.279 0.279 0.279 kg/ha *** Record 13 90 1 0 0 *** Record 15 -- PSTNAM Cyromazine *** Record 16 010661 0 2 0.0 0.279 .95 .05 080661 0 2 0.0 0.279 .95 .05 150661 0 2 0.0 0.279 .95 .05 010662 0 2 0.0 0.279 .95 .05 080662 0 2 0.0 0.279 .95 .05 150662 0 2 0.0 0.279 .95 .05 010663 0 2 0.0 0.279 .95 .05 080663 0 2 0.0 0.279 .95 .05 150663 0 2 0.0 0.279 .95 .05 010664 0 2 0.0 0.279 .95 .05 080664 0 2 0.0 0.279 .95 .05 150664 0 2 0.0 0.279 .95 .05 010665 0 2 0.0 0.279 .95 .05 080665 0 2 0.0 0.279 .95 .05 150665 0 2 0.0 0.279 .95 .05 010666 0 2 0.0 0.279 .95 .05 080666 0 2 0.0 0.279 .95 .05 150666 0 2 0.0 0.279 .95 .05 010667 0 2 0.0 0.279 .95 .05 080667 0 2 0.0 0.279 .95 .05 150667 0 2 0.0 0.279 .95 .05 010668 0 2 0.0 0.279 .95 .05 080668 0 2 0.0 0.279 .95 .05 150668 0 2 0.0 0.279 .95 .05 010669 0 2 0.0 0.279 .95 .05 080669 0 2 0.0 0.279 .95 .05 150669 0 2 0.0 0.279 .95 .05 010670 0 2 0.0 0.279 .95 .05 080670 0 2 0.0 0.279 .95 .05 150670 0 2 0.0 0.279 .95 .05 010671 0 2 0.0 0.279 .95 .05 080671 0 2 0.0 0.279 .95 .05 150671 0 2 0.0 0.279 .95 .05 010672 0 2 0.0 0.279 .95 .05 080672 0 2 0.0 0.279 .95 .05 150672 0 2 0.0 0.279 .95 .05 010673 0 2 0.0 0.279 .95 .05 080673 0 2 0.0 0.279 .95 .05 150673 0 2 0.0 0.279 .95 .05

## 27 010674 0 2 0.0 0.279 .95 .05 080674 0 2 0.0 0.279 .95 .05 150674 0 2 0.0 0.279 .95 .05 010675 0 2 0.0 0.279 .95 .05 080675 0 2 0.0 0.279 .95 .05 150675 0 2 0.0 0.279 .95 .05 010676 0 2 0.0 0.279 .95 .05 080676 0 2 0.0 0.279 .95 .05 150676 0 2 0.0 0.279 .95 .05 010677 0 2 0.0 0.279 .95 .05 080677 0 2 0.0 0.279 .95 .05 150677 0 2 0.0 0.279 .95 .05 010678 0 2 0.0 0.279 .95 .05 080678 0 2 0.0 0.279 .95 .05 150678 0 2 0.0 0.279 .95 .05 010679 0 2 0.0 0.279 .95 .05 080679 0 2 0.0 0.279 .95 .05 150679 0 2 0.0 0.279 .95 .05 010680 0 2 0.0 0.279 .95 .05 080680 0 2 0.0 0.279 .95 .05 150680 0 2 0.0 0.279 .95 .05 010681 0 2 0.0 0.279 .95 .05 080681 0 2 0.0 0.279 .95 .05 150681 0 2 0.0 0.279 .95 .05 010682 0 2 0.0 0.279 .95 .05 080682 0 2 0.0 0.279 .95 .05 150682 0 2 0.0 0.279 .95 .05 010683 0 2 0.0 0.279 .95 .05 080683 0 2 0.0 0.279 .95 .05 150683 0 2 0.0 0.279 .95 .05 010684 0 2 0.0 0.279 .95 .05 080684 0 2 0.0 0.279 .95 .05 150684 0 2 0.0 0.279 .95 .05 010685 0 2 0.0 0.279 .95 .05 080685 0 2 0.0 0.279 .95 .05 150685 0 2 0.0 0.279 .95 .05 010686 0 2 0.0 0.279 .95 .05 080686 0 2 0.0 0.279 .95 .05 150686 0 2 0.0 0.279 .95 .05 010687 0 2 0.0 0.279 .95 .05 080687 0 2 0.0 0.279 .95 .05 150687 0 2 0.0 0.279 .95 .05 010688 0 2 0.0 0.279 .95 .05 080688 0 2 0.0 0.279 .95 .05 150688 0 2 0.0 0.279 .95 .05 010689 0 2 0.0 0.279 .95 .05 080689 0 2 0.0 0.279 .95 .05 150689 0 2 0.0 0.279 .95 .05 010690 0 2 0.0 0.279 .95 .05 080690 0 2 0.0 0.279 .95 .05 150690 0 2 0.0 0.279 .95 .05 *** Record 17 0 1 0 *** Record 18 0 0 0.5 *** Record 19 -- STITLE "Conant Silt Loam MLRA M-146, Aroostook County, ME" *** Record 20 100 0 0 0 0 0 0 0 0 0 *** Record 26 0 0 0 *** Record 33 4

## 28 1 10 1.25 0.341 0 0 0 0.0047060.004706 0 0.1 0.341 0.121 4.64 2.25 2 16 1.25 0.341 0 0 0 0.0047060.004706 0 4 0.341 0.121 4.64 2.25 3 64 1.4 0.266 0 0 0 0.0047060.004706 0 4 0.266 0.116 0.174 2.25 4 10 1.6 0.261 0 0 0 0.0047060.004706 0 5 0.261 0.111 0.116 2.25 ***Record 40 0 YEAR 10 YEAR 10 YEAR 10 1 1 1 ----- 7 YEAR PRCP TCUM 0 0 RUNF TCUM 0 0 INFL TCUM 1 1 ESLS TCUM 0 0 1.0E3 RFLX TCUM 0 0 1.0E5 EFLX TCUM 0 0 1.0E5 RZFX TCUM 0 0 1.0E5



## PRZM-EXAMS WATER COLUMN CONCENTRATION

ME Potato

WATER COLUMN DISSOLVED CONCENTRATION (PPB)

YEAR PEAK 96 HOUR 21 DAY 60 DAY 90 DAY YEARLY

---- ---- ------- ------ ------ ------ ------ 1961 3.041 3.023 2.939 2.845 2.685 1.263 1962 4.468 4.390 4.192 3.884 3.719 2.485 1963 4.458 4.437 4.325 4.057 3.877 2.713 1964 4.584 4.550 4.412 4.200 4.089 2.855 1965 4.687 4.670 4.589 4.448 4.392 3.383 1966 5.372 5.347 5.274 5.222 5.148 3.860 1967 5.850 5.797 5.588 5.149 4.975 3.784 1968 5.004 4.954 4.866 4.715 4.594 3.461 1969 5.484 5.459 5.348 5.067 4.814 3.370 1970 4.628 4.598 4.486 4.344 4.262 2.851 1971 3.853 3.837 3.780 3.650 3.580 2.678 1972 7.069 7.024 6.847 6.651 6.323 4.067 1973 5.328 5.282 5.074 4.686 4.516 3.635 1974 5.101 5.076 4.994 4.802 4.610 3.468 1975 5.644 5.604 5.551 5.415 5.330 4.208 1976 7.370 7.264 7.006 6.535 6.112 4.317 1977 7.367 7.297 7.063 6.704 6.206 4.070 1978 5.873 5.802 5.554 5.228 5.089 3.931 1979 4.643 4.618 4.575 4.485 4.323 3.343 1980 4.972 4.932 4.853 4.725 4.592 3.365 1981 5.355 5.323 5.257 4.889 4.277 2.819 1982 4.732 4.675 4.516 4.215 4.047 2.647 1983 6.123 6.050 5.818 5.346 5.090 3.368 1984 6.740 6.687 6.476 6.152 5.959 4.249 1985 5.593 5.576 5.500 5.400 5.281 4.691 1986 4.718 4.703 4.634 4.454 4.278 3.449

## 29 1987 5.348 5.319 5.239 5.080 4.934 3.734 1988 4.928 4.908 4.825 4.657 4.495 3.662 1989 5.096 5.070 4.987 4.826 4.631 3.584 1990 8.977 8.888 8.666 8.051 7.696 4.554

SORTED FOR PLOTTING

------ --- --------

PROB PEAK 96 HOUR 21 DAY 60 DAY 90 DAY YEARLY

---- ---- ------- ------ ------ ------ ------ .032 8.977 8.888 8.666 8.051 7.696 4.691 .065 7.370 7.297 7.063 6.704 6.323 4.554 .097 7.367 7.264 7.006 6.651 6.206 4.317 .129 7.069 7.024 6.847 6.535 6.112 4.249 .161 6.740 6.687 6.476 6.152 5.959 4.208 .194 6.123 6.050 5.818 5.415 5.330 4.070 .226 5.873 5.802 5.588 5.400 5.281 4.067 .258 5.850 5.797 5.554 5.346 5.148 3.931 .290 5.644 5.604 5.551 5.228 5.090 3.860 .323 5.593 5.576 5.500 5.222 5.089 3.784 .355 5.484 5.459 5.348 5.149 4.975 3.734 .387 5.372 5.347 5.274 5.080 4.934 3.662 .419 5.355 5.323 5.257 5.067 4.814 3.635 .452 5.348 5.319 5.239 4.889 4.631 3.584 .484 5.328 5.282 5.074 4.826 4.610 3.468 .516 5.101 5.076 4.994 4.802 4.594 3.461 .548 5.096 5.070 4.987 4.725 4.592 3.449 .581 5.004 4.954 4.866 4.715 4.516 3.383 .613 4.972 4.932 4.853 4.686 4.495 3.370 .645 4.928 4.908 4.825 4.657 4.392 3.368 .677 4.732 4.703 4.634 4.485 4.323 3.365 .710 4.718 4.675 4.589 4.454 4.278 3.343 .742 4.687 4.670 4.575 4.448 4.277 2.855 .774 4.643 4.618 4.516 4.344 4.262 2.851 .806 4.628 4.598 4.486 4.215 4.089 2.819 .839 4.584 4.550 4.412 4.200 4.047 2.713 .871 4.468 4.437 4.325 4.057 3.877 2.678 .903 4.458 4.390 4.192 3.884 3.719 2.647 .935 3.853 3.837 3.780 3.650 3.580 2.485 .968 3.041 3.023 2.939 2.845 2.685 1.263

1/10 7.337 7.240 6.990 6.639 6.197 4.310

MEAN OF ANNUAL VALUES = 3.462

STANDARD DEVIATION OF ANNUAL VALUES = .715

UPPER 90% CONFIDENCE LIMIT ON MEAN = 3.656



## PRZM-EXAMS PORE WATER CONCENTRATION

ME Potato

PORE WATER DISSOLVED CONCENTRATION (PPB)

YEAR PEAK 96 HOUR 21 DAY 60 DAY 90 DAY YEARLY

---- ---- ------- ------ ------ ------ ------

## 30 1961 1.910 1.910 1.906 1.888 1.873 .898 1962 3.023 3.023 3.021 3.009 2.984 2.195 1963 3.130 3.130 3.128 3.111 3.088 2.594 1964 3.382 3.382 3.377 3.344 3.309 2.612 1965 3.681 3.681 3.680 3.667 3.647 3.136 1966 4.349 4.349 4.344 4.315 4.277 3.599 1967 4.174 4.174 4.166 4.118 4.063 3.624 1968 3.876 3.875 3.870 3.839 3.806 3.267 1969 3.994 3.994 3.991 3.951 3.892 3.367 1970 3.465 3.465 3.458 3.411 3.349 2.776 1971 2.959 2.959 2.956 2.944 2.931 2.477 1972 5.390 5.390 5.381 5.322 5.250 3.934 1973 4.267 4.255 4.206 4.099 4.002 3.572 1974 3.765 3.765 3.765 3.760 3.755 3.289 1975 4.614 4.614 4.613 4.606 4.592 3.847 1976 5.091 5.091 5.081 5.023 4.965 4.345 1977 5.036 5.035 5.023 4.957 4.888 3.964 1978 4.260 4.260 4.258 4.249 4.236 3.728 1979 4.131 4.127 4.096 3.984 3.878 3.392 1980 3.786 3.786 3.784 3.774 3.758 3.077 1981 3.750 3.749 3.721 3.576 3.432 2.978 1982 3.346 3.346 3.344 3.329 3.303 2.374 1983 4.106 4.106 4.101 4.072 4.033 3.081 1984 4.937 4.937 4.937 4.931 4.919 3.904 1985 4.915 4.912 4.901 4.871 4.836 4.545 1986 4.341 4.330 4.267 4.064 3.909 3.481 1987 4.093 4.092 4.091 4.085 4.070 3.438 1988 3.886 3.877 3.841 3.763 3.751 3.534 1989 3.882 3.881 3.874 3.842 3.814 3.431 1990 5.949 5.948 5.942 5.872 5.773 4.255

SORTED FOR PLOTTING

------ --- --------

PROB PEAK 96 HOUR 21 DAY 60 DAY 90 DAY YEARLY

---- ---- ------- ------ ------ ------ ------ .032 5.949 5.948 5.942 5.872 5.773 4.545 .065 5.390 5.390 5.381 5.322 5.250 4.345 .097 5.091 5.091 5.081 5.023 4.965 4.255 .129 5.036 5.035 5.023 4.957 4.919 3.964 .161 4.937 4.937 4.937 4.931 4.888 3.934 .194 4.915 4.912 4.901 4.871 4.836 3.904 .226 4.614 4.614 4.613 4.606 4.592 3.847 .258 4.349 4.349 4.344 4.315 4.277 3.728 .290 4.341 4.330 4.267 4.249 4.236 3.624 .323 4.267 4.260 4.258 4.118 4.070 3.599 .355 4.260 4.255 4.206 4.099 4.063 3.572 .387 4.174 4.174 4.166 4.085 4.033 3.534 .419 4.131 4.127 4.101 4.072 4.002 3.481 .452 4.106 4.106 4.096 4.064 3.909 3.438 .484 4.093 4.092 4.091 3.984 3.892 3.431 .516 3.994 3.994 3.991 3.951 3.878 3.392 .548 3.886 3.881 3.874 3.842 3.814 3.367 .581 3.882 3.877 3.870 3.839 3.806 3.289 .613 3.876 3.875 3.841 3.774 3.758 3.267 .645 3.786 3.786 3.784 3.763 3.755 3.136 .677 3.765 3.765 3.765 3.760 3.751 3.081 .710 3.750 3.749 3.721 3.667 3.647 3.077 .742 3.681 3.681 3.680 3.576 3.432 2.978 .774 3.465 3.465 3.458 3.411 3.349 2.776 .806 3.382 3.382 3.377 3.344 3.309 2.612 .839 3.346 3.346 3.344 3.329 3.303 2.594

## 31 .871 3.130 3.130 3.128 3.111 3.088 2.477 .903 3.023 3.023 3.021 3.009 2.984 2.374 .935 2.959 2.959 2.956 2.944 2.931 2.195 .968 1.910 1.910 1.906 1.888 1.873 .898

1/10 5.086 5.085 5.075 5.016 4.960 4.226



## PRZM-EXAMS SEDIMENT CONCENTRATION

ME Potato

BENTHIC SEDIMENT CONCENTRATION (ug/kg)

YEAR PEAK 96 HOUR 21 DAY 60 DAY 90 DAY YEARLY

---- ---- ------- ------ ------ ------ ------ 1961 5.004 5.004 4.993 4.947 4.908 2.354 1962 7.921 7.921 7.916 7.883 7.818 5.752 1963 8.201 8.201 8.194 8.152 8.090 6.796 1964 8.862 8.861 8.847 8.761 8.671 6.845 1965 9.645 9.645 9.642 9.609 9.555 8.215 1966 11.400 11.390 11.380 11.310 11.210 9.430 1967 10.940 10.940 10.910 10.790 10.640 9.494 1968 10.150 10.150 10.140 10.060 9.972 8.559 1969 10.460 10.460 10.460 10.350 10.200 8.822 1970 9.079 9.078 9.060 8.937 8.775 7.274 1971 7.752 7.752 7.746 7.712 7.678 6.489 1972 14.120 14.120 14.100 13.940 13.760 10.310 1973 11.180 11.150 11.020 10.740 10.480 9.358 1974 9.865 9.865 9.863 9.852 9.838 8.616 1975 12.090 12.090 12.090 12.070 12.030 10.080 1976 13.340 13.340 13.310 13.160 13.010 11.390 1977 13.190 13.190 13.160 12.990 12.810 10.380 1978 11.160 11.160 11.160 11.130 11.100 9.768 1979 10.820 10.810 10.730 10.440 10.160 8.887 1980 9.919 9.919 9.915 9.888 9.847 8.063 1981 9.825 9.822 9.750 9.369 8.992 7.803 1982 8.765 8.765 8.761 8.721 8.654 6.220 1983 10.760 10.760 10.750 10.670 10.570 8.072 1984 12.940 12.940 12.930 12.920 12.890 10.230 1985 12.880 12.870 12.840 12.760 12.670 11.910 1986 11.370 11.350 11.180 10.650 10.240 9.119 1987 10.720 10.720 10.720 10.700 10.660 9.008 1988 10.180 10.160 10.060 9.859 9.829 9.258 1989 10.170 10.170 10.150 10.070 9.993 8.989 1990 15.590 15.590 15.570 15.380 15.120 11.150

SORTED FOR PLOTTING

------ --- --------

PROB PEAK 96 HOUR 21 DAY 60 DAY 90 DAY YEARLY

---- ---- ------- ------ ------ ------ ------ .032 15.590 15.590 15.570 15.380 15.120 11.910 .065 14.120 14.120 14.100 13.940 13.760 11.390 .097 13.340 13.340 13.310 13.160 13.010 11.150 .129 13.190 13.190 13.160 12.990 12.890 10.380 .161 12.940 12.940 12.930 12.920 12.810 10.310 .194 12.880 12.870 12.840 12.760 12.670 10.230 .226 12.090 12.090 12.090 12.070 12.030 10.080 .258 11.400 11.390 11.380 11.310 11.210 9.768

## 32 .290 11.370 11.350 11.180 11.130 11.100 9.494 .323 11.180 11.160 11.160 10.790 10.660 9.430 .355 11.160 11.150 11.020 10.740 10.640 9.358 .387 10.940 10.940 10.910 10.700 10.570 9.258 .419 10.820 10.810 10.750 10.670 10.480 9.119 .452 10.760 10.760 10.730 10.650 10.240 9.008 .484 10.720 10.720 10.720 10.440 10.200 8.989 .516 10.460 10.460 10.460 10.350 10.160 8.887 .548 10.180 10.170 10.150 10.070 9.993 8.822 .581 10.170 10.160 10.140 10.060 9.972 8.616 .613 10.150 10.150 10.060 9.888 9.847 8.559 .645 9.919 9.919 9.915 9.859 9.838 8.215 .677 9.865 9.865 9.863 9.852 9.829 8.072 .710 9.825 9.822 9.750 9.609 9.555 8.063 .742 9.645 9.645 9.642 9.369 8.992 7.803 .774 9.079 9.078 9.060 8.937 8.775 7.274 .806 8.862 8.861 8.847 8.761 8.671 6.845 .839 8.765 8.765 8.761 8.721 8.654 6.796 .871 8.201 8.201 8.194 8.152 8.090 6.489 .903 7.921 7.921 7.916 7.883 7.818 6.220 .935 7.752 7.752 7.746 7.712 7.678 5.752 .968 5.004 5.004 4.993 4.947 4.908 2.354

1/10 13.325 13.325 13.295 13.143 12.998 11.073

## 33 T-REX and T-HERPS MODEL OUTPUT Acute and Chronic RQs are based on the Upp e Kenaga Residues.

Chemical Name: The maximum single day residue estimation i s Use both the acute and reproduction RQs.
Formulation Application Rate 0.249 lbs a.i./acre RQs reported as "0.00" in the RQ tables b e Half-life 7 days <0.01 in your assessment. This is due to r o Application Interval 7 days figure issues in Excel. Maximum # Apps./Year 3

Length of Simulation 1 year Variable application rates? no

Bobwhite quail LD50 (mg/kg-bw) 1706.00

Bobwhite quail LC50 (mg/kg-diet) 0.00

Mallard duck NOAEL(mg/kg-bw) 0.00

Mallard duck NOAEC (mg/kg-diet) 75.00

2029.00

0.00 54.60 1000.00

Kenaga Values Short Grass 104.58 Tall Grass 47.93 Broadleaf plants 58.83 Fruits/pods/seeds 6.54 Arthropods 40.96


### 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 2 3 114 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 1229.05 100 1564.65 1000 2210.12

small mid large

20 100 1000 Short Grass 119.11 67.92 30.41 Tall Grass 54.59 31.13 13.94 Broadleaf plants 67.00 38.20 17.10 Fruits/pods 7.44 4.24 1.90 Arthropods 46.65 26.60 11.91 Seeds 1.65 0.94 0.42 

### Dose-based EECs (mg/kg-bw) Avian Classes and Body Weights (grams) Upper Bound Kenaga Residues For RQ Calculation



### Dietary-based EECs (ppm) NOAEL (mg/kg-bw) NOAEC (mg/kg-diet) 

### Mammals LD50 (mg/kg-bw) LC50 (mg/kg-diet) cyromazine

potatoes 0



### Avian Endpoints Questions? Comments?

Click here

## 34 20 100 1000 Short Grass 0.10 0.04 0.01 Tall Grass 0.04 0.02 0.01 Broadleaf plants 0.05 0.02 0.01 Fruits/pods 0.01 0.00 0.00 Arthropods 0.04 0.02 0.01 Seeds 0.00 0.00 0.00 

### Dietary-based RQs

Acute Chronic Short Grass #DIV/0! 1.39 Tall Grass #DIV/0! 0.64 Broadleaf plants #DIV/0! 0.78 Fruits/pods/seeds #DIV/0! 0.09 Arthropods #DIV/0! 0.55

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

cyromazine potatoes Upper bound Kenaga Residues 

### 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 2305.39 120.00 Herbivores/ 35 1865.31 97.09 insectivores 1000 806.80 42.00 15 2305.39 120.00 Granivores 35 1865.31 97.09 1000 806.80 42.00

15 35 1000 Short Grass 99.71 68.91 15.98 Tall Grass 45.70 31.58 7.32 Broadleaf plants 56.09 38.76 8.99 Fruits/pods 6.23 4.31 1.00 Arthropods 39.05 26.99 6.26 Seeds 1.38 0.96 0.22

15 grams 35 grams 1000 grams Acute Chronic Acute Chronic Acute Chronic Short Grass 0.04 0.83 0.04 0.71 0.02 0.38 Tall Grass 0.02 0.38 0.02 0.33 0.01 0.17 Broadleaf plants 0.02 0.47 0.02 0.40 0.01 0.21 Fruits/pods 0.00 0.05 0.00 0.04 0.00 0.02 Arthropods 0.02 0.33 0.01 0.28 0.01 0.15 Seeds 0.00 0.01 0.00 0.01 0.00 0.01

Acute Chronic Short Grass #DIV/0! 0.10 Tall Grass #DIV/0! 0.05 Broadleaf plants #DIV/0! 0.06 Fruits/pods/seeds #DIV/0! 0.01 Arthropods #DIV/0! 0.04

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 

### Dietary-based RQs (Dietary-based EEC/LC50 or NOAEC ) Mammal RQs Medium mammal Large mammal 

### Dose-based RQs (Dose-based EEC/LD50 or Small mammal 

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

### Dose-based RQs (Dose-based EEC/adjusted LD50)

RQs Avian Acute RQs Size Class (grams)

## 35 Acute and Chronic RQs are based on the Upper Bound Kenaga Residues.

Chemical Name: The maximum single day residue estimation is used for
Use both the acute and reproduction RQs.
Formulation Application Rate 0.249 lbs a.i./acre RQs reported as "0.00" in the RQ tables below should be not e Half-life 7 days <0.01 in your assessment. This is due to rounding and signifi Application Interval 7 days figure issues in Excel. Maximum # Apps./Year 3

Length of Simulation 1 year

Bobwhite quail LD50 (mg/kg-bw) 1706.00 Bobwhite quail LC50 (mg/kg-diet) 5373.00 Bobwhite quail NOAEL(mg/kg-bw) 0.00

Mallard duck NOAEC (mg/kg-diet) 75.00

Kenaga Values Short Grass 104.58 Tall Grass 47.93 Broadleaf plants/sm Insects 58.83 Fruits/pods/seeds/lg insects 6.54

Small herbivore mammals 234.93

Medium herbivore mammal 80.17 Large herbivore mammal 27.35 Small insectivore mammals 14.68

Medium Insectivorous mammal 5.01 Large Insectivorous mammal 1.71 Small terrestrial phase amphibians 3.23 Medium terrestrial phase amphibians 1.85 Large terrestrial phase amphibians 1.05

Terrestrial Herpetofauna Results

Weight Body Ingestion (Fdry) Ingestion (Fwet) % body wgt FI Class Weight (g) (g bw/day) (g/day) consumed (kg-diet/day) Small 2 0.022 0.1 5.6 1.11E-04 Mid 20 0.132 0.7 3.3 6.59E-04 Large 200 0.781 3.9 2.0 3.90E-03

Body A djusted LD50 Weight (g) (mg/kg-bw) 2 1706.00 20 1706.00 200 1706.00

small (g) mid (g) large (g)

2 20 200 Short Grass 5.81 3.44 2.04 Tall Grass 2.66 1.58 0.94 Broadleaf plants/sm Insects 3.27 1.94 1.15

Fruits/pods/seeds/lg insects 0.36 0.22 0.13 Herbivore mammals 246.78 99.17 39.85

Insectivore mammals 15.42 6.20 2.49 Reptile/Terrestrial phase amphibian 3.39 2.28 1.54

2 2 0 200 Short Grass 0.00 0.00 0.00 Tall Grass 0.00 0.00 0.00 Broadleaf plants/sm insects 0.00 0.00 0.00 Fruits/pods/seeds/lg insects 0.00 0.00 0.00 Herbivore mammals 0.14 0.06 0.02 Insectivore mammals 0.01 0.00 0.00 Terrestrial phase amphibian 0.00 0.00 0.00

Acute Chronic Short Grass 0.02 1.39 Tall Grass 0.01 0.64 Broadleaf plants/sm Insects 0.01 0.78 Fruits/pods/seeds/lg insects 0.00 0.09 potatoes

0

Herpetofaunal Size Classes and Body Weights

RQs Upper Bound Kenaga Residues For RQ Calculation

Dietary-based EECs (ppm) cyromazine

Endpoints

Avian

Dietary-based RQs (Dietarybased EEC/LC50 or NOAEC) Amphibian/Reptile Acute RQs for Small, Medium, and Large Species (grams) Dose-based RQs (Dose- based EEC/adjusted LD50) Dose-based EECs (mg/kg-bw) Questions? Comments? Click here

## 36 2 2 0 200 Short Grass 0.00 0.00 0.00 Tall Grass 0.00 0.00 0.00 Broadleaf plants/sm insects 0.00 0.00 0.00 Fruits/pods/seeds/lg insects 0.00 0.00 0.00 Herbivore mammals 0.14 0.06 0.02 Insectivore mammals 0.01 0.00 0.00 Terrestrial phase amphibian 0.00 0.00 0.00

Acute Chronic Short Grass 0.02 1.39 Tall Grass 0.01 0.64 Broadleaf plants/sm Insects 0.01 0.78 Fruits/pods/seeds/lg insects 0.00 0.09 Herbivore mammals 0.01 1.07 Insectivore mammals 0.00 0.07 Terrestrial phase amphibian 0.00 0.02 RQs Dietary-based RQs (Dietary- based EEC/LC50 or NOAEC) Amphibian/Reptile Acute RQs for Small, Medium, and Large Species (grams) Dose-based RQs (Dose- based EEC/adjusted LD50)

## 37 AgDrift example output.