-Page 1 of 88- OFFICE OF
CHEMICAL SAFETY AND
POLLUTION PREVENTION 

### UNITED STATES ENVIRONMEN TAL PROTECTION AGENCY WASHINGTON D.C., 20460

PC Code: 018986

DP Barcode: D409544

Date: February 10, 2015

MEMORANDUM

SUBJECT: Environmental Fate and Ecological Ri sk Assessment for Use of the New Herbicide Bicyclopyrone (NOA449280)

TO : Erick Kraft, Risk Manager Reviewer Shaja Joyner, Product Manager Rachel Holloman, Branch Chief Fungicide and Herbicide Branch Registration Division (7505P)

FROM: Andrew Sayer, Ph.D., Biologist Cheryl Sutton, Ph.D., Environmental Scientist

Environmental Risk Branch IV Environmental Fate and Effects Division (7507P)

REVIEWED Thomas Steeger, Ph.D., Senior Science Advisor

BY: Jim Carleton, Ph.D., Senior Scientist

Environmental Risk Branch IV Environmental Fate and Effects Division (7507P)



## APPROVED

BY: Jean Holmes, DVM, Branch Chief

Environmental Risk Branch IV Environmental Fate and Effects Division (7507P)

The Environmental Fate and Effects Division (EFED) has completed a review of the new herbicide bicyclopyrone (PC Code 018986) and its proposed use on corn as a pre-emergent or early post-emergent herbicide vi a ground spray application. The review assessed two formulated end-use products, as a soluble concentrate (SC, in SYN-A16003; 18.1% a.i.) and a mixed formulation capsule suspension and suspension concentrate (ZC; in SYN-A19707; 0.65% a.i.) herbicide. The mixed formulation product, which is proposed as a restricted use (RU) pesticide, also contains atrazine (PC Code 080803), meso trione (PC Code 122990), and S-metolachlor (PC Code 108800). This evaluation is limited to th e exposure associated with bicyclopyrone-Page 2 of 88- 

### specifically and not the other compounds; however, the likeli hood of adverse effects from exposure to the formulated product(s) is assess ed, where data are sufficient to permit such analyses, based on the content of bicyclopyrone in the relevant formulations. For environmental exposure, only the parent compound alone is considered a residue of concern.

Based on peak estimated environmental concen trations (EECs) and the most sensitive ecotoxicity data across multiple taxa, bi cyclopyrone exposure at the maximum proposed application rates may result in risk to federally listed threatened and endangered (hereafter referred to as “listed”) species of terrestrial and semi-aquatic dicotyledonous (dicot) plants. Risk

estimates also exceed the levels of concern (LOC) for listed and non-listed vascular aquatic plants and the chronic ri sk LOC for mammals.

Data Gaps/Uncertainties

Environmental Fate/Exposure

There are no environmental fate data gaps for bicyclopyrone; howev er, there is some uncertainty introduced by a supplemental non-guideline aero bic aquatic metabolism study in which the test soil was irradiated during the incubation (M RID 47842075). Because of the multiple issues associated with the study, it is classified as “reliable with restrictions.”

Additionally, the registrant has sought to show that parent co mpound transported below the soil surface may be wicked upward through evaporative transport flux in the soil and subsequently photodegraded on the surface soil, resulting in more rapid degradation than would occur in soil through metabolism alone (MRIDs 47842030, 47842170). However, in prospective groundwater studies following parent bicycl opyrone application, the soil transformation product SYN503780 was detected in wells at sampling inte rvals up to 3 years after application.

The labels specify that bicyclopy rone is generally to be applied once annua lly; however, a split application for pre-emergent and early post- emergent is allowed, provided the maximum recommended application/year of 0.04 lb a.i./A (50 g/ha) is not exceeded. Aquatic exposure in this assessment is based on the single pre-emergent application. If a split a pplication is used, the acute aquatic exposure in the envi ronment may be less than that qua ntified in this assessment.

Terrestrial exposure in this assessment is based on a single application. Al so, if applied as a preemergent, bicyclopyrone will be a pplied to the soil surface rather than on growing plants. Thus, actual terrestrial exposure in the environment may be less than that estimated quantitatively in

this assessment.

Ecological Effects

No data have been submitted for chronic toxicity to estuarine/marine fish and invertebrates. Therefore, a mysid chronic toxicity test (O CSPP 850.1350) and estuarine/marine fish early-life stage test (OCSPP 850.1400) are clas sified as data gaps. Howe ver, acute-to-chronic ratios (ACRs) have been calculated based on freshwater toxicity data to estimate chronic toxicity endponts for estuarine/marine fish and invertebrates.-Page 3 of 88- 

### The submitted acute oral toxicity study to a passerine species (OCSPP 850.2100; MRID 478420- 78) was classified as supplemental because regurgitation and mortality across the multiple concentrations tested. Furthermore, the study su ggests that passerines may be more sensitive to

either the mallard duck or bobwhite quail and thus would be importa nt in the characterization for avian taxa. EFED has develope d guidance on the testing of pa sserines where regurgitation has

been an issue 1 

### ; this guidance indicates that a dietar y study should be conducted in the event regurgitation cannot be prevented.

Although data indicate bicyclopyr one is practically non-toxic to young adult bees on both an acute contact and oral exposure basis, there is uncertainty regarding the potential acute and chronic effects of the compound on honey bee la rval development and survival as well as potential for chronic effects of adult bees. Sin ce bicyclopyrone is a systemic herbicide, residues may be present in pollen and/or nectar and re present a route of exposure for bees through both contact and ingestion. Therefore, additional data on pollinators is needed to fully characterize the risk associated with bicyclopyrone use to all developmental stages of honey bees, as sensitivity may vary according to life-stage and le ngth of exposure (adult vs. larval and acute vs. chronic, respectively). As described in the guidance for assessing risks to bees 2,3 

### , depending on the outcome of the screening-level risk assessment, additional studies of b ees at the colony level under semi- and full-field conditions may also be recommended.

Label Recommendations

As noted in the Label Review Manual 4 

### , since the product is inte nded for outdoor use, the following statement should appear in the Environmental Hazards Section:

“ For terrestrial uses: Do not apply directly to water, or to area s where surface water is present or to intertidal areas below the mean high water mark. Do not contaminate water when disposing of equipment washwater or rinsate ”.

“ Bicyclopryrone is known to leach through soil into groundwater under certain conditions as a result of label use. This chemical may leach into groundwater if used in areas where soils are permeable, particularly where the water table is shallow. ”

Label language pertaining to Environmental Hazar d Statements differs between labels for the two end-use products, with one prohibiting disc harge of effluent containing bicyclopyrone

without a National Pollutant Di scharge Elimination System (N PDES) permit, and the other prohibiting direct application to water or contamination of wash water or rinsate. While Ground

1 USEPA. 2012. Guidance for Use When Regurgitation is Observed in Avian Acute Toxicity Studies with Passerine Species. Memora ndum from Donald J. Brady. http://www.epa.gov/pesticides/sci ence/efed/policy_guidance/team_authors/terrest rial_biology_tech_team/rr_regurg_acute_passerine .pdf

2 USEPA. 2014. Guidance for Assessing Pesticide Risks to Bees. O ffice of Pesticide Programs. United States Environmental Protec tion Agency.

Available at http://www.epa.gov/pesticides/sci ence/efed/policy_guidance/team_authors/terrest rial_biology_tech_team/GuidanceAssessingPesticid eRisk2Bees. pdf

3 http://www2.epa.gov/sites/production/f iles/2014-06/documents/pollinator_r isk_assessment_guida nce_06_19_14.pdf

4 USEPA. 2012. Lavel Review Manual, Chapter 8: Environmental Hazards. http://www2.epa.gov/sites/production/files/documents/chap08_2.pdf-Page 4 of 88- 

### Water Advisories are alrea dy on the proposed label for th e product SYN-A19707, which also contains the active ingredients at razine and s-metolachlor, it is not on the labe l for the product SYN-A16003, although bicyclopyrone chemical properties are simila r to other chemicals which have been found in groundwater, and bicyclopyrone and one of its degradates was detected in submitted Prospective Groundwater Monitoring studies.

With respect to NPDES statements, the Labe l Review Manual recommends the following

statement:

“ Do not discharge effluent containing this product into lakes, streams, p onds, estuaries, oceans,

or other waters unless in accordance with the requirements of a National Pollutant Discharge Elimination System (NPDES) pe rmit and the permitting authority has been notified in writing prior to discharge. Do not discharge effluent c ontaining this product to sewer systems without previously notifying the local sewage treatment plant authority. For guidan ce contact your State Water Board or Regional Office of the EPA ”.

Given the expected high mobility of the pa rent compound, the label should also state:

“ This product has a high potential for reaching surface water via runoff for several months or more after application A level, well-maintained vegetative buffer strip between areas to which this product is applied and surface water featur es such as ponds, streams, and springs will reduce the potential loading of bicyclopyrone from runoff wate r and sediment. Runoff of this product will be reduced by avoiding applications wh en rainfall or irrigation is expected to occur

within 48 hours. ”-Page 5 of 88- 

# Environmental Fate and Ecological Risk Assessment for Use of the new Herbicide Bicycl opyrone (NOA449280)

O CF 3 

## N O OH O OMe



## Bicyclopyrone

CAS 352010-68-5 PC Code 018986



### 10 February 2015

Prepared by Andrew Sayer, Ph.D., Biologist Cheryl Sutton, Ph.D., Environmental Scientist U.S. Environmental Protection Agency
Office of Pesticide Programs Environmental Fate and Effects Division (EFED)

Environmental Risk Branch IV 1200 Pennsylvania Ave., NW

Mail Code 7507P Washington, DC 20460 

### Reviewed by Thomas Steeger, Ph.D., Senior Science Advisor Jim Carleton, Ph.D., Senior Fate Scientist Jean Holmes, D.V.M., Branch Chief-Page 6 of 88- 

# Table of Contents

1. Executive Summary ............................................................................................................. .............................. 9

2. Problem Formulation ........................................................................................................... ........................... 10

2.1. Nature of Chemical Stressor ................................................................................................... ................ 10

2.2. Stressor Source and Distribution .............................................................................................. .............. 10

2.3. Receptors...................................................................................................................... ............................. 11

2.4. Assessment Endpoints .......................................................................................................... .................... 11

2.5. Conceptual Model .............................................................................................................. ...................... 12

2.5.1. Risk Hypothesis ............................................................................................................... ................ 12

2.5.2. Conceptual Model Pathways and Effects ...................................................................................... 12

2.6. Analysis Plan ................................................................................................................. ........................... 14

2.6.1. Conclusions from Previous Risk Assessments .............................................................................. 14

2.6.2. Identification of Data Gaps and Uncert ainties ............................................................................. 14

2.6.3. Measures of Exposure .......................................................................................................... ........... 15

2.6.4. Measures of Effect ............................................................................................................ ............... 16

2.6.5. Integration of Expo sure and Effects ........................................................................................... ... 17

3. Analysis ...................................................................................................................... ....................................... 18

3.1. Use Characterization .......................................................................................................... ..................... 18

3.2. Exposure Charac terization ..................................................................................................... ................. 18

3.2.1. Environmental Fate and Transport .............................................................................................. . 18

3.2.2. Aquatic Exposure .............................................................................................................. .............. 26

3.2.3. Terrestrial Ex posure .......................................................................................................... ............. 29

3.3. Ecological Effects Characterization ........................................................................................... ............. 31

3.3.1. Ecotoxicity Data .............................................................................................................. ................. 31

3.3.1. Terrestrial Organism and Mamm alian Chronic Endpoints ........................................................ 42

3.3.2. Terrestrial Plants ............................................................................................................ ................. 44

3.3.3. Incident Reports .............................................................................................................. ................ 46

4. Risk Characterization ......................................................................................................... ............................. 46

4.1. Risk Esti mation ............................................................................................................... ......................... 46

4.1.1. Aquatic Or ganisms ............................................................................................................. ............. 46

4.1.2. Terrestrial Or ganisms ......................................................................................................... ............ 48

4.2. Risk Description and Conclusions .............................................................................................. ............ 52

4.2.1. Aquatic Or ganisms ............................................................................................................. ............. 52

4.2.2. Terrestrial Or ganisms ......................................................................................................... ............ 52

4.2.3. Conclusions ................................................................................................................... ................... 53

5. Federally Threatened and Endangered (Listed) Species of Concern .......................................................... 54

5.1. Action Area ................................................................................................................... ............................ 54

5.2. Taxonomic Groups Potentially at Risk .......................................................................................... ........ 55

6. References .................................................................................................................... ..................................... 58



## List of Tables

Table 2.1. List of the various models and the related t axa for which the models will be used to assess risk. .... 13 Table 3.1. Summary of use information for th e bicyclopyrone propos ed use on corn. ....................................... 18 Table 3.2. Leaching Depths and Concentrations in U.S. Terrestrial Field Dissipation Studies ......................... 20 Table 3.3. Chemical properties and environmen tal fate parameters of bicyclopyrone. ...................................... 21 Table 3.4. Input values for the SWCC model for bicyclopyrone 1 .......................................................................... 26

Table 3.5. SWCC scenarios and i nputs for bicyclop yrone modeling ............................................................... ..... 27 Table 3.6. Input Values for the SC I-GROW model for bicyclopyrone. ............................................................. ... 27 Table 3.7. Input values for the PRZM-GW model for bicyclopyrone. .............................................................. .... 28

Table 3.8. Estimated environmental concentr ations for bicyclopyrone use on corn. .......................................... 29 Table 3.9. PRZM-GW and SCI-GROW groundwater EECs for bicyclopyrone use on corn. ............................ 29-Page 7 of 88- Table 3.10. Terrestrial EECs as food residues for anim als exposed to bicyclopyrone as a result of the proposed pre-emergent use. .................................................................................................... .................................. 30 Table 3.11. EECs for non-target terres trial and semi-aquatic plants based on proposed use of bicyclopyrone (TerrPlant ). .................................................................................................................. .............................................. 31 Table 3.12. Acute toxicity endpoints used in risk estimation and characterization fo r freshwater organisms exposed to bicyclopyrone. ..................................................................................................... .................................... 34 Table 3.13. Acute toxicity endpoint s used in risk estimati on and characterization for estuarine/marine organisms exposed to bicyclopyrone. ........................................................................................... ............................ 34 Table 3.14. Toxicity endpoints used in risk estimation and characterization for aquatic plants and algae exposed to bicyclopyrone. ..................................................................................................... .................................... 35 Table 3.15. Chronic toxicity endpoints used in risk estimation and characteriza tion for fish and aquatic invertebrates exposed to bicyclopyrone. ....................................................................................... ........................... 37 Table 3.16. Acute toxicity endpoint s used in risk estimati on and characterization for birds and mammals exposed to bicyclopyrone. ..................................................................................................... .................................... 40 Table 3.17. Acute toxicity en dpoints used in risk estima tion and characterization for terrestrial invertebrates exposed to bicyclopyrone. ..................................................................................................... .................................... 40 Table 3.18. Chronic toxicity endpoints used in risk es timation and characterizati on for terrestrial animals exposed to bicyclopyrone. ..................................................................................................... .................................... 43 Table 3.19. Toxicity endpoints used in risk estimation and characteriza tion for terrestrial and semi-aquatic plants exposed to bicyclopyrone. .............................................................................................. ................................ 44 Table 3.20: Most sensitive 21-day seedling emergence endpoints for plant sp ecies exposed to bicyclopyrone . 45 Table 3.21: Most sensitive 21-day vegetative vigor en dpoints for plant species exposed to bicyclopyrone ....... 46 Table 4.1. Acute and chronic RQ valu es for freshwater fish and invertebra tes exposed to bicyclopyrone TGAI

in surface water. ............................................................................................................. ............................................ 47 Table 4.2. Acute and chronic RQ valu es for freshwater fish and inverteb rates exposed to bicyclopyrone TEP (A16003E) in surface water. ................................................................................................... ................................... 47 Table 4.3. Acute and chronic RQ valu es for estuarine/marine fish and in vertebrates exposed to bicyclopyrone

TGAI in surf ace water. ........................................................................................................ ..................................... 47 Table 4.4. RQ values for listed and non-listed vasc ular and nonvascular aquatic plants exposed to bicyclopyrone TGAI in surface water as a result of spray drift only, based on maximum application rates for

corn. ......................................................................................................................... ................................................... 48 Table 4.5. RQ values for listed and non-listed vasc ular aquatic plants exposed to bicyclopyrone TEP (A15749AD) in surface water as a result of spray drift only, based on maximum application rates for corn. . 48 Table 4.6. RQ values for listed and non-listed nonvas cular aquatic plants exposed to bicyclopyrone TEP (A16003E) in surface water as a result of spray drift only, based on maximum application rates for corn...... 48

Table 4.7. Acute a avian, sub-acute dietary, and chronic ,b dietary-based RQ values for TGAI bicyclopyrone. . 49

Table 4.8. Acute mammalian dose-b ased RQ values for proposed pre-emergent use of bicyclopyrone on

corn. 1,2

.............................................................................................................................. ........................................... 49 Table 4.9. Chronic mammalian dose-based RQ values for proposed pre-emergent us e of bicyclopyrone on

corn. 1

.............................................................................................................................. ............................................. 50 Table 4.10. RQ values for non-listed species 1 of non-target terres trial and semi-aquatic plants based on bicyclopyrone on co rn (TerrPla nt). ............................................................................................ .............................. 50 Table 4.11. RQ values for listed species 1 of non-target terres trial and semi-aquatic plants based on bicyclopyrone on co rn (TerrPla nt). ............................................................................................ .............................. 50 Table 4.12. Seedling Emergence RQ val ues for listed and non-listed species 1 of non-target plants based on bicyclopyrone on corn using ground water-derived irrigation water. ............................................................. ...... 51 Table 4.13. Vegetative vigor RQ values for listed and non-listed species 1 of non-target plants based on bicyclopyrone on corn using ground water-derived irrigation water. ............................................................. ...... 51

Table 4.14. Possible Effects Distance for Nontarget Terrestrial Plants Exposed to Bicyclopyrone through Spray Drift Only Based on the Most Sensitive Cr op Species in Submitte d Toxicity Studies. ............................. 51 Table 5.1. Potential effects to federally listed avia n taxa associated with the proposed used of TGAI bicyclopyrone. ................................................................................................................ ............................................ 57



## Appendices

Appendix A. Proposed Ne w Uses, Bicyclopyrone ................................................................................. ................. 67-Page 8 of 88- Appendix B. Bicyclopyrone and its Envi ronmental Transforma tion Products .................................................. 68 Appendix C. SW CC Results ..................................................................................................... ............................... 76 Appendix D. Groundwat er Modeling Results ..................................................................................... ................... 81 Appendix E. Example STIR (v. 1.0) input and output data ...................................................................... ............ 83 Appendix F. Ecotoxicity da ta gaps and uncertainties .......................................................................... ................. 84 Appendix G. Example T-REX (v. 1. 5.2) input and output data ................................................................... ........ 86 Appendix H. Example TerrPlant (v. 1.2.2) input and output data ............................................................... ........ 88-Page 9 of 88- 

## 1. Executive Summary

Bicyclopyrone is characterized as a select ive, systemic herbicide belonging to the hydroxyphenylpyruvate dioxygenase (H PPD)-inhibitor class, and is purportedly within the

subclass of the tri-ket one chemistry (although only two ketone groups are evident). It is intended as a pre-emergence to early post-emergence he rbicide and is applied using standard ground spraying equipment. Bicyclopyrone is gene rally applied once annually; however, a split application for pre-emergent and early post-emer gent is allowed, provided the maximum rate of 0.04 lb a.i./A (50g/ha) per year, with a minimum 14- day application interval , is not exceeded.

Bicyclopyrone is a relatively soluble, nonvolatile compound that is stable to hydrolysis and is expected to be very highly mobile in soil. Bicyclopyrone photodegrades on surface soil, with half-lives ranging from 4 to 13 da ys. In laboratory studies conducte d in darkness, it is slightly persistent to persistent in aerobic soil, metabo lizing to multiple organic transformation products

and carbon dioxide. It is stable in anaerobi c soil and anaerobic aquatic systems, and only degrades very slowly in aerobic aquatic systems, with half-lives of 393-68 1 days. Bicyclopyrone photodegrades slowly in wa ter, with half-l ives of 11 to 75 days. Based on its octanol-water partition coefficient (log K ow 

### -1.2 at pH 7), bicyclopyrone is not expected to bioaccumulate in aquatic and terrestrial organisms.

Bicyclopyrone may move to groundwater via l eaching, and may move to surface water bodies via spray drift and runoff of disso lved or sorbed residues. In aerobic soil metabolism studies, two of the major transformation products (i ncluding SYN503780) were found to be nonpersistent in aerobic soil, with half-lives of <1 -7.1 days. Laboratory metabolism and field studies also showed in general that persistence in the environment was not an expected issue for these transformation products. However, in prospective groundwater monitoring studies following bicyclopyrone application the tran sformation product SYN 503780 was detected in wells at up to 3 years after application.

Bicyclopyrone is classified as slig htly to practically non-toxic to freshwater and estuarine/marine fish (and to aquatic-phase amphibian s for which freshwater fish serv e as surrogates) as well as to freshwater invertebrates, but is moderately toxic to estuarine/marine invertebrates on an acute exposure basis. An end-use product (A16003E) of bicy clopyrone is classified as slightly toxic to

freshwater fish and invertebra tes (although reported to xicity endpoints in studies using A1600E were greater than the highest concentration tested and not tested at concen trations as high as the technical grade active ingredient [TGAI] bicy clopyrone). Bicyclopyr one is slightly to moderately toxic to birds on an acute oral expo sure basis and is practi cally non-toxic to birds (and to terrestrial-phase amphibians and reptile s for which birds serve as surrogates) on a subacute dietary exposure basis. The compound is classified as practically non-toxic to mammals on an acute oral exposure basis and it is practically non-toxic to and to young adult honey bees ( Apis mellifera ) on both an acute contact and oral exposure basi s. No statistically significant effects were observed in either the freshw ater fish early life stage toxicity test or the

freshwater invertebrate full life cycle test after chronic exposure to bicyclopyrone. No chronic

estuarine/marine fish or invertebrate studies were submitted and therefore acute-to-chronic ratios (ACRs) were used to estimate chronic toxicity endpoints for estuarine/marine animals.

Mammalian chronic effects included decreased growth. Chronic effects in birds included-Page 10 of 88- 

### decreased hatchling growth in both bobwhite quail ( Colinus virginianus ) and mallard ducks ( Anas platyrhynchos ).

Toxicity to aquatic vascular and non-vasc ular plants was obs erved upon exposure to bicyclopyrone. Additionally, exposure to the formulated product A15749AD resulted in decreased growth of vascular aquatic plants while bicyclopyrone metabolites CSAA589691 and

CSCC163768 had no effect. While toxic effects were observed in nonvascular green algae and freshwater and marine diatoms, no toxic effect s were observed in blue -green algae following bicyclopyrone exposure. The en d-use product A16003E, also tested using green algae, resulted in a more sensitive toxicity endpoint than the TGAI.

Bicyclopyrone typical end-use product (TEP) A 15749F (containing 150 g a.i./L bicyclopyrone) exhibited effects (decreased gr owth) with the terrestrial monoc otyledonous (monocot) ryegrass and dicotyledonous (dicot) cabbage plants being the most sensitive species in seedling emergence studies, and the monocot onion and dicot sunflower being the most sensitive plants in the vegetative vigor studies.

Bicyclopyrone exposure at the labele d application rates may result in risk to federally listed threatened and endangered (hereafter referred to as “listed”) species of terrestrial and semiaquatic dicots. Risk to listed dicot plants ex ceeds the Agency’s level of concern (LOC) for preemergent use ( i.e. , on cabbage and sunflower). The likelihood of acute mortality in fish, invertebrates, mollusks, aquatic-phase amphibians, birds, reptiles, terres trial-phase amphibians, and mammals is considered low as RQ values do not exceed the Agency’s acute risk LOC. Conversely, dose-based RQ values exceed the chronic risk LOC for mammals. Since bicyclopyrone is practica lly non-toxic to adult bees on an acute exposure basis, no RQ values are calculated; however, there is unc ertainty regarding the potential for adverse effects on honey bee adults from chronic exposure and to honey bee la rvae from either acute or chronic exposure.



## 2. Problem Formulation

2.1. Nature of Chemical Stressor

Bicyclopyrone [4-hydroxy-3-[[2-[(2-methoxyethoxy) methyl]-6-(trifluoro methyl)-3-pyridinyl] carbonyl]bicyclo[3.2.1]oc t-3-en-2-one; CAS # 352010-68-5) is a selective, systemic herbicide of the HPPD-inhibitor class, and is in the subclass of the tri-ke tone chemistry. Bicyclopyrone inhibits the enzyme hydroxyphenyl pyruvate dioxygenase (HPPD) in the chlorophyll biosynthesis pathway. The mode of action of bicyclopyrone is shared with multiple other registered active ingredients, such as mesotrione, isoxaflutol e, topramezone, tembot rione, pyrasulfatole. Bicyclopyrone is intended to control broad leaf weeds and annual grasses in corn in the U.S and is also undergoing registration for use in Canada on corn and in Australia for use on sugarcane.

2.2. Stressor Source and Distribution

Bicyclopyrone is contained in two formulated end- use products, as a soluble concentrate (SC, in SYN-A16003; 18.1% a.i.) or mixed formulation capsule suspension and suspension concentrate (ZC; in SYN-A19707; 0.65% a.i.) herbicide. Bicycl opyrone is proposed for use in corn as a pre--Page 11 of 88- 

### emergent or early post-emergent herbicide vi a ground spray application. The mixed formulation product, which is proposed as a restricted use (RU) pesticide, also contai ns atrazine, mesotrione,

and S-metolachlor. This evaluation is limited to the exposure associat ed with bicyclopyrone specifically and not the other compounds; however, risk based on exposure to the formulated product(s) is assessed, where data are sufficient to permit anal ysis, based on the content of bicyclopyrone in the rele vant formulations.

For ecological exposure, only the parent compound is considered a residue of concern. Major environmental transformation products of a com pound may be of exposure concern. Available

environmental fate data indi cate that the five major transformation products CSCC163768 (SYN504810), CSAA589691 (NOA412101), CSCD642512 (SYN545859), CSCD656832 (SYN545680) and SYN503780 (CSAA794148) may be present in the environment following use of bicyclopyrone. These degradates of exposur e concern were further examined to determine which of them might be a factor in risk (rather than exposure) concern (USEPA 2014a). In the absence of toxicity data, predicted acute and chr onic toxicity values for the major transformation products of bicyclopyrone were estimated us ing EPA’s Ecological Structure Activity Relationships (ECOSAR) tool (v 1.11) 5 

### which is based on quantitative structure activity relationships (QSAR) for effects on fish, daphnids, mysids, and gree n algae. Predicted toxicity values were also generated for parent bicyclopy rone and compared to observed endpoints from registrant-submitted studies to assess confidence in ECOSAR predictions of the toxicity of bicyclopyrone’s transformation pr oducts. Based on the comparisons to parent, it was tentatively determined that only the transforma tion product CSCD656832 (SYN545680) might be a potential stressor of concern in the ecological risk assessment. Ho wever, based on its detections in laboratory studies, it was present mainly as a minor degradate in aerobic soil studies, reaching

a level of ≥ 10% in only one of 16 soils studied. While it was also detected as a minor degradate in a soil photodegradation study, data from such studies are not used in aquatic exposure modeling. Additionally, in adsorption studies, th e compound was only moderately mobile in one soil and slightly mobile in three soils. Thus, it was determined that it was highly unlikely that inclusion of CSCD656832 residues in aquatic exposure modeling would alter the risk

conclusions.

2.3. Receptors

A receptor is a biological entity that is exposed to a stressor (USEPA 1998). For this assessment, the receptors include terrestr ial and aquatic plants and an imals inhabiting fields where bicyclopyrone is applied, and those inhabiting non-target areas to which bicyclopyrone may be transported ( e.g ., via spray drift and runoff) . Consistent with the process described in the Overview Document (USEPA 2004), the risk assessm ent uses a surrogate sp ecies approach in its evaluation of bicyclopyrone. Toxicological data ge nerated from surrogate test species, which are intended to be representative of broad taxonomic groups, are used to extrapolate to potential effects on a variety of species (receptors) included under these taxonomic groupings.

2.4. Assessment Endpoints

Assessment endpoints represent the ac tual environmental value that is to be protected, defined by

5 http://www.epa.gov/oppt/newchems/tools/21ecosar.htm-Page 12 of 88- 

### an ecological entity ( e.g ., species, community) and its at tributes (USEPA 1998). For bicyclopyrone, the ecological entities include bird s, mammals, freshwater fish and invertebrates, estuarine/marine fish and invertebrates, terrestria l plants, insects, and aqua tic plants and algae.

The attributes evaluated for each of these entities may include growth, reproduction, and

survival.

2.5. Conceptual Model

For a pesticide to pose an ecological risk, it must reach ecological r eceptors in biologically significant concentrations. An exposure pathway is the means by which a pesticide moves in the environment from a source to an ecological recepto r. For an ecological pathway to be complete, it must have a source, a release mechanism, an environmental transport medium, a point of exposure for ecological receptors, an d a feasible route of exposure.

A conceptual model provides a description of the predicted relationships between bicyclopyrone, the potential routes of exposur e, and the predicted effects for each assessment endpoint.

2.5.1. Risk Hypothesis

For bicyclopyrone, the following eco logical risk hypothesis is empl oyed for this risk assessment:

Bicyclopyrone has high mobility in so il; it can move to surface water through spray drift and runoff, and it has potential to leach to ground water in vulnerable environments (e.g., high water tables, high rainfall/i rrigation, sandy soils, etc.). Therefore, bicyclopyrone may produce adverse effects on survival, growth, and/or reproduction of aquatic plants and animals, may pose a chronic risk to small bi rds, terrestrial-phase amphibians, terrestrial plants, invertebrates, reptiles, and mammals. Bees and other pollinators may be at risk due to the systemic nature of the compound and the possibility that residues could be transported to pollen and nectar on which bees forage. To the extent to which terrestrial and/or aquatic plants are affected by the proposed uses of the he rbicide, other taxa may be indirectly affected via di rect effects on primary pr oductivity and loss of habitat.

2.5.2. Conceptual Model Pathways and Effects

The environmental fate properties of bicyclopyrone indicate that for ground spray applications, spray drift, and runoff are potenti al transport mechanisms to a quatic habitats where non-target organisms may be exposed. It is expected that non-target terrestrial organisms can be exposed to bicyclopyrone following pre-emergent applicat ion, through consumption of exposed plants and invertebrates on the treated field. The plant uptake of the chemical may be a pathway of

exposure to non-target terres trial organisms upon consumpti on. Additionally, bicyclopyrone may reach terrestrial environments off treated fi elds via spray drift, and via application of irrigation groundwater containing residues of bicyclopyrone. A summary of the transport pathways and the models used to generate esti mated environmental concentrations (EECs) for those pathways in the as sessment is provided in Table 2.1.-Page 13 of 88- 

###  As bicyclopyrone is nonvolatile , atmospheric transport is no t a major transport pathway. Additionally, the Screening Tool for Inhalati on Risk (STIR) version 1.0 (November 23, 2010) indicates that exposure via inhalation is not likely to be a risk concern for birds and mammals ( Appendix E ). Additionally, the low log K ow 

### (-1.2) suggests that bicyclopyrone is not likely to bioconcentrate or bioaccumulat e in aquatic or terrestrial organisms. With a log acid dissociation cons tant (pKa) of 3.06, bicyclopyrone will exist predominantly as an anion at environmental pH values in U.S. soils. Based on this as well as on submitted soil mobility data, bicy clopyrone is expected to be very highly mobile in soil. Therefore, bicyclopyrone has the potential to leach to groundwater. While bicyclopyrone does not ha ve chemical properties that suggest strong pa rtitioning to sediment, some chemical will inevitably m ove into benthic sediment pore water via

diffusion. Potential risk to sediment-d welling organisms due to exposure to bicyclopyrone in pore water is not evaluated in this assessment, but cannot be precluded. Bicyclopyrone may be applied using standard spraying equipment; thus spray drift is expected to result in exposure to organisms off of treated fields when broadcast applications of liquids occur in s ituations conducive to spray drift.

The transport pathways may result in exposure to various aquatic a nd terrestrial organisms. With exposure, the following attribute change s have the potential to occur:

 Effects to individual organisms,

 Effects to food webs (reduction in prey a nd food, modification of primary constituent elements (PCE) related to prey availability), and

 Effects to habitat integrity (reduction in primary productivi ty, reduced cover, community change, and modification of PCE related to habitat).

Table 2.1. List of the various models and the related taxa for which the models will be used to assess risk.

Environment Taxa of

Concern Exposure

Media Exposure Pathway Model(s) or Pathway Attribute Change

Aquatic Vertebrates/

Invertebrates
Surface water/

sediment Runoff and spray

drift to water and

sediment SWCC Individual Organisms

Food Chain Habitat Integrity

Aquatic Plants (vascular and nonvascular) Food Chain Habitat Integrity

Riparian plants See terrestrial exposure pathways Habitat Integrity

Terrestrial Vertebrate Dietary items Ingestion of

residues in/on dietary items, including treated

seeds as a result

of direct application T-REX Individual Organisms

Food Chain Habitat Integrity

Consumption of aquatic organisms Residues taken up by aquatic

organisms Not a major

transport pathway ----Page 14 of 88- Environment Taxa of

Concern Exposure

Media Exposure Pathway Model(s) or Pathway Attribute Change

Plants Spray drift/runoff Runoff and spray drift to plants TERRPLANT AgDRIFT Individual Organisms

Food Chain Habitat Integrity Surface water Residues in irrigation water

leaching to groundwater SWCC

Groundwater SCIGROW

PRZM-GW

Bees and other

terrestrial

invertebrates 1 Dietary items Spray contact and ingestion of

residues in/on dietary items as

a result of direct

application. Uptake of pollen/nectar from plants. Multiple models Individual Organisms Colony/Population Integrity

All

Environments All Movement through air to aquatic and

terrestrial media Spray drift AgDRIFT (Spray drift) Individual Organisms

Food Chain Habitat Integrity Atmospheric

transport Not a major

transport pathway

Text in italics represent transport pathways that are not of concern.

1 See pollinator SAP white paper for full list of modeling approaches for evaluating exposure used in this assessment (USEPA 2012).



### 2.6. Analysis Plan

The analysis plan is the final step in the Probl em Formulation. During this step, an assessment design is developed, the scope of the assessment is outlined, the met hods for conducting the assessment are determined, measurements of effect s and exposure to evaluate the risk hypothesis are delineated, and initial data gaps and assumptions required to address them are identified.

2.6.1. Conclusions from Previous Risk Assessments

As this is a new registration, there are no previous US EPA ecological risk assessments for bicyclopyrone.

2.6.2. Identification of Data Gaps and Uncertainties

In terms of environmental fate studies required to support the registrati on of bicyclopyrone, there are no data gaps for bicyclopyrone. With respect to data requirements to support the assessment of ecological effects, the submitted passerine study was classified as supplemental due to uncertainties regarding actual exposure as te st birds exhibited regu rgitation (MRID 47842078). In this study, mortality coincided with regurgitation at multiple treatment levels.

No data have been submitted for chronic effects to estuarine/marine fish and invertebrates and

would be beneficial to characte rize the toxic effects of bicyclopyr one to these taxa. Therefore,-Page 15 of 88- 

### an estuarine/marine invertebrate life-cycle test (OCSPP 850.1350) and an estuarine/marine fish early-life stage test (OCSPP 850.1400) are listed as data gaps. However, acute-to chronic ratios (ACRs) based on freshwater fish and invertebrate toxicity valu es have been calculated to

estimate estuarine/marine fish and inve rtebrate toxicity values, respectively.

Although data from the acute contact and oral t oxicity tests with young adult honey bees indicate bicyclopyrone is practica lly non-toxic to bees on an acute exposure basis, ther e is uncertainty regarding the potential acute and chronic ef fects of the compound on honey bee larval development and survival as well as potentia l for chronic effects of adult bees. Since bicyclopyrone is a systemic herbicide, residue s may be transported by the plant into pollen and/or nectar and represent a route of exposure for bees thr ough ingestion of residues in pollen/nectar.

2.6.3. Measures of Exposure

Screening-level assessments are intended to be protective of wildlife on a national level, as opposed to being regionally or lo cally specific. Therefore, this assessment is not intended to represent a spatially- or temporally-specific anal ysis. Maximum application rates are used to model EECs. Measures of exposure are ba sed on aquatic and terrestrial models ( Table 2.1 ) that calculate EECs using maximum proposed applica tion rates and methods. Groundwater is also assessed due to the leaching poten tial of bicyclopyrone and the potential to use groundwater as irrigation water on crops. As this is a new registration, there are currently no monitoring data for bicyclopyrone for comparison to model-genera ted surface water EECs. Limited groundwater data are available from multiple submitted Pros pective Groundwater studies conducted outside

of the United States.

The Surface Water Concentration Calculator (SWCC, v 1.106, May, 2014) is used to generate EECs representing concentrations that may occu r in surface water. The SWCC simulates pesticide transformation on and runoff from an agri cultural field (in addition to loadings from spray drift), following applications to crops. The model then simulates resulting concentrations in an adjacent surface water body ( i.e ., the standard pond).

Groundwater concentrations are estimated using the Screening Concentration in Ground Water (SCI-GROW, v. 2.3, 8/8/2003) model as well as the PRZM-GW model (Pes ticide Root Zone Model for Groundwater, version 1.07), with the GW-GUI (Graphical User Interface, version 1.0, August 31, 2012). PRZM-GW is a one-dimensiona l leaching model that estimates the concentrations of pesticides in groundwater. It account s for pesticide fate in the crop root zone by simulating pesticide transport and degradation through the soil profile af ter a pesticide is applied to an agricultural field. PRZM-GW perm its the assessment of multiple years of pesticide application (up to 100 years) on a single site. Six standard scenarios, each representing a different region known to be vulnerable to groundw ater contamination, are available for use with PRZM-GW for risk assessment purposes. SCI-GROW is a regression model used as a screening tool to estimate potential pest icide concentrations in vulnerabl e groundwater that might be used as drinking water. SCI-GROW was develo ped by fitting a linear model to groundwater concentrations with the Relative Index of Leaching Potential (RILP) as the independent variable.

Groundwater concentrations were taken from 90-day average high concentrations from-Page 16 of 88- 

### Prospective Ground Water studies; the RILP is a function of aerobic soil metabolism and the soil-water partition coefficient.

The Terrestrial Residue Exposure Model (T-REX , version 1.5.2, 6/20/2013) is used to derive

terrestrial EECs on food items for terrestria l vertebrates. Uppe r-bound Kenega nomogram values used in T-REX are based on Hoerger and Kenega (1972) as modified by Fletcher et al

. (1994) are used to derive EECs for terrestria l mammals and birds based on dietary- and dosebased exposures from pre-emergent applicati ons. A one-year time period is simulated. Consideration is given to differe nt types of feeding strategies for mammals and birds, including herbivores, insectivores and gr anivores. For dose-based exposur es, three weight classes of mammals (15, 35, and 1000 g) and birds (20, 100, and 1000 g) are considered.

The TerrPlant model (v. 1.2.2, 12/26/2006) is us ed to derive runoff EECs for estimating exposures to terrestrial plants inhabiting dry and semi-aquatic areas. Exposure estimates using the Screening Tool for Inhalation Risk (STIR, v. 1.0, 11/23/2010) indicated that inhalation was not expected to be a significan t route of exposure for wildlife ( Appendix E ). Exposure models are parameterized using relevant use (proposed label rates) and environmental fate data according to current EFED model input parameter guidance. 6



### To characterize potential non-targ et plant exposure from spray drift alone, Tier 1 modules in AgDRIFT (v. 2.1.1, December 2011) were used to es timate how far off-site spray drift exposure might occur at a level known to cause adverse eff ects in terrestrial plant toxicity studies. For ground applications, EFED used the American So ciety of Agricultural and Biological Engineers (ASABE, formerly ASAE) Very Fine-to-Fine dropl et size category in it s modeling. This size category is EFED’s default distribution when labe ls do not specify application parameters. The volume median diameter (Dv 50 

### ) for the Very Fine-to-Fine dr oplet size dist ribution is 175

microns.

The K ow 

### -based Aquatic BioAccumulation Model (KABAM) 7 

### v. 1.0 is used to estimate potential bioaccumulation of hydrophobic organic pesticid es in freshwater aquatic food webs and subsequent risks to mammals and birds via consumption of contaminated aquatic prey. However, KABAM modeling is not triggere d by bicyclopyrone’s physicochemical

characteristics and therefore is not used in th is assessment. A waiver request for a fish bioaccumulation study was submitted by the registrant (MRID 47842117). The waiver request was granted because the chemical properties of bi cyclopyrone indicate it is polar and would be expected to be lipophobic based on the K ow 

### and solubility (the log K ow 

### is 0.25, -1.2, and -1.9, at pH’s 5, 7, and 9 respectively).

2.6.4. Measures of Effect

Measures of effect are obtained from a suite of registrant-submitted guideline studies which are conducted with a limited number of surrogate speci es. The test species are not intended to be representative of the most sensitiv e species but rather are selected based on their ability to thrive under laboratory conditions. For example, toxi city testing reported in this risk assessment

6 http://www.epa.gov/oppefed1/models/w ater/input_parameter_guidance.htm

7 http://www.epa.gov/oppefed1/models/w ater/kabam/kabam_user_guide.html-Page 17 of 88- 

### utilizes surrogate species to represent all freshwater fi sh (>2000 species) and birds (>680 species) identified in the U.S. Open literature s earches were not conducted to identify data for potential use in this risk assessment becau se bicyclopyrone is a new active ingredient.

The acute measures of effect used in this scre ening-level assessment include the median lethal dose (LD 50 

### ), median lethal concentration (LC 50 

### ), and the median effect concentration (EC 50 

### ). These are measures of acute toxicity which resu lt in 50% of the respective effect in tested organisms. The endpoints for chronic measures of effect are the No Observed Adverse Effects Concentration (NOAEC) and the No Observed Adverse Effects Level (NOAEL). Toxicity studies are submitted for freshwater fish and invertebrates, estuarine/marine fish and invertebrates, aquatic and terr estrial plants, birds, mammals and honey bees. The measurement endpoints used for risk characterization are de rived from studies which underwent review and are classified as “acceptable” (conducted under guideline conditions and considered to be scientifically sound) or “supplemental” (conditions deviated from guidelin es but the results are scientifically sound).

2.6.5. Integration of Exposure and Effects

The exposure and effects data are integrated to evaluate the risk s of adverse ecological effects on non-target species. For the screening-level asse ssment of bicyclopyrone, the deterministic, risk quotient (RQ) method is used to compare estimated exposure and m easured toxicity values. The RQ method involves dividi ng EECs by the most sensitive acute and chronic toxicity values for specific taxa. The resulting RQs are then compar ed to the Agency’s levels of concern (LOCs) (USEPA 2004) for acute and chronic risk. These cr iteria are used to indicate if applications of bicyclopyrone, as directed on the proposed label, have the potential to cause adverse effects to non-target organisms.

Although risk is often described in terms of the likelihood and magn itude of adverse effects, the risk quotient-based approach does not provide a quantitative estimate of likelihood or magnitude of an adverse effect, but rather provides a “y es” or “no” answer depending upon whether or not

LOCs are exceeded.-Page 18 of 88- 

## 3. Analysis

3.1. Use Characterization

Bicyclopyrone is a new chemical proposed for us e in controlling broad leaf weeds and annual grasses in corn in the U.S., at the maximum annua l application rate of 0.045 lb a.i./A (50 g/ha). It is to be applied from pre-emergence thro ugh early post-emergence using standard ground spraying equipment. Based on labe l instructions, bicyclopyrone is generally to be applied once per season; however, a split application ( i.e ., pre-emergent and early post-emergent) that equates to the maximum recommended application/year (with a minimum 14-day re -application interval) may be used for corn grown for grain, seed or silage.

Bicyclopyrone will be contained in one of two proposed products, a soluble concentrate (SC; 18.1% a.i.; SYN-A16003 Herbicide; EPA Reg. No. 100-RUAA), and a Re stricted Use product (RUP) consisting of a mixed formulation of a capsule suspension and suspension concentrate (CS and SC; 0.65% a.i.; SYN-A19707 Herbicide; EPA Reg. No. 100-RUAL). In the RUP, bicyclopyrone will be co-formulated with the othe r active ingredients mesotrione, atrazine, and S-metolachlor. The Canadian registration is for both products, while the Australian registration is for the SC only. As noted earlier, mesotrione has a common mode of ac tion as bicyclopyrone,

i.e. , HPPD inhibition.

Table 3.1. Summary of use in formation for the bicyclopyr one proposed use on corn.

Use Max. Single Applic. Rate

(lbs a.i./A) Max. Seasonal Applic. Rate (lbs a.i./A) Seasonal Max. # of App. Min. App. Interval (d) EPA Reg. No.

Corn (field corn, seed corn, silage corn, yellow popcorn

and sweet corn) 2 0.045 0.045 2 1 14 100-RUAA (SYN-A16003)

Corn (field corn, seed corn, silage corn, yellow popcorn and sweet corn) 0.045 3 0.045 3 2 Not stated,

but 2 nd applicationmust be postemergence 100-RUAL (SYN-A19707;

Restricted Use product)

1 The typical use will be once per year (as modeled in this assess ment), but the label allows fo r a split application up to the m aximum annual application for corn grown for grain, seed or silage.

2 Applications to sweet corn and yellow popcorn must be pre-emergent only. 3 Single and seasonal rate for this product reduce to 0.0375 lb a.i./A for soils with an organic matter content of <3.5% (bas ed on the atrazine component of the co-formulation).



### 3.2. Exposure Characterization

3.2.1. Environmental Fate and Transport

Bicyclopyrone is a relatively so luble, nonvolatile compound that is stable to hydrolysis across all tested pH levels (MRID 47841919). Based on an acid dissociation constant (pKa) of 3.06, which indicates that approximately 50% of a compound will be ionized at an equivalent pH, with increasing percentages as pH in creases, bicyclopyrone will exis t predominantly as an anion (positively charged ion) at envir onmentally relevant pH values in U.S. soils, and available data-Page 19 of 88- 

### indicate that adsorption is not correlated with soil organic matter. Based on this as well as on submitted soil mobility data, bicyclopyrone is expected to be very highly mobile in soil (MRIDs 47842055, 47842056, 47842057, 47842059). Bicyclopyrone photode grades on soil, with halflives ranging from 4 to 13 days (mean of 7.6; n=3; MRID 47842029). In laboratory studies conducted in darkness, it ranges from slightly persistent to persiste nt in aerobic soil, metabolizing to multiple organic transformation pr oducts and carbon dioxide. In the 12 domestic and European soils studied, aerobic soil metabolis m half-lives ranged from 20 to 350 days (mean of 165 days), indicating a wi de variation in persiste nce across soils (MRIDs 47842026, 47842033, 47842034). In four Brazilian soils, all of which were acidic (p H range of 3.5-5.9), the half-life ranged from 82 to 434 days (mean of 243; MRID 4 7842035). The compound is stable in anaerobic soil and anaerobic aqua tic systems (MRIDs 47842027, 47842073, 47842074), and is relatively stable in aerobic aquatic system s, with half-lives of 393-681 days (mean of 550; n=4) in the latter (MRIDs 47842073, 47842074). Although it onl y photodegrades slowly in water, with respective half-lives of 11 and 50 days at pH 5 and 7 buffered water, and 74.8 days in natural water (pH 7.3; MRID 47841921), and is rela tively stable in aerobic aquatic systems, bicyclopyrone degraded with a ha lf-life of roughly 7.5 days in a non-guideline aerobic aquatic metabolism study that was irradiated during the incubation (MRID 47842075). However, the significance of this result is unclear, and there were multiple uncertainties with the study that

resulted in a classification of “r eliable with restrictions.”

Three of the transformation products of bicyclopyrone are characterized as very highly mobile in soil. The major transformation product CSCC1 63768 has Freundlich organic carbon-normalized coefficients (K FOC 

### s) of 2.8 and 3.4 L/kg in two soil s studied (MRID 47842062). Adsorption coefficients could not be quantitatively de termined for the major transformation product SYN503780 and the minor transformation produc t CSAA806573 due to lack of adsorption (MRIDs 47842060, 47842061). The major transforma tion product CSCD656832 was moderately mobile in one soil and slightly mobile in three soils, with K FOC 

### s of 247, 1340, 5179, 6180 L/kg (MRID 47842155). Structures and maximum concentr ations for these and other transformation products are listed by study in Appendix B

.

In terrestrial field dissipation studies, bicyclopyrone was non-pers istent, with dissipation halflives of 1.7-4.4 days in bare-ground plot studie s conducted at three site s in the U.S. (MRIDs 47842038, 47842039, 47842040). The application rate (0.196 lb a.i./A) used in the U.S. studies was over four times the currently pr oposed application rate for corn (and is slightly greater than the proposed U.S. application rate at the time the studies were conducted). However, concentrations of the pesticide in time 0 sa mples were 55%, 80% and 104% of the nominal application rate. Nine field studies conducte d in Europe and one field study conducted in Australia were also submitted. Across all sites, the dissipation half-life was generally five weeks or less (see footnotes, Table 3.3 ).

In the terrestrial field dissipat ion studies conducted in the U.S ., limited leaching of bicyclopyrone and its transformation products was observed ( Table 3.2 ), despite water inputs of 116-207% of the historical averages. Runoff was not monitore d in the studies. Transformation products were a collective maximum of 23.2% (7 days) in the GA study, 20.4% (3 a nd 7 days; single degradate) in the IA study, and 14% (day 1; single degrad ate) in the NE study. Thus, while the parent rapidly dissipated from the surface soils, it was unclear what the predominant routes of-Page 20 of 88- 

### dissipation were in each study. Based on labo ratory data, aerobic soil transformation and photodegradation on soil are potentially major pathways of dissipa tion. It is noted that the major soil photolysis transformation product, SYN503780, was detected at all three sites. The registrant has submitted a non-guideline study (not formally reviewed) suggesting that parent compound transported below the surface may be wicked upward through evaporative transport flux in the soil and subsequently photodegraded on the surface soil. However, in that nonguideline study, the correlation betw een half-lives and total irradi ance is poor (with and without accounting for water input during the first week), and it is noted that the maximum concentration for the photodegradate SYN503780 wa s observed at 1 day post-trea tment in two of the three U.S. field studies, rather than fu rther along in the studies as might be expected if such a wicking process was occurring. Additionally, the lack of de tections of the parent compound or the very highly mobile degradate CSCC1637 68 at depths greater than 0-15 cm throughout the 536- to 546-day studies may indicate that conditions may not have been conducive to leaching or the compound was degraded before leaching could o ccur. Water balance information was not reported for any of the U.S. terre strial field di ssipation studies.

Table 3.2. Leaching Depths and Concentrations in U.S. Terrestrial Field Dissipation Studies

Test System Apparent Major Route of Dissipation Maximum Concentrations and Depths (cm soil; days after application)

Georgia

Dothan soil series Sandy loam
pH 5.9 Transformation 1 Soil Bicyclopyrone: 0.198 lb/A (0-15 cm; day-0) SYN503780: 0.015 lb/A (0-15 cm; 1 day) CSCD656832: 0.023 lb/A (0-15 cm; 21 days) CSCD642512: 0.005 lb/A (0-15 cm; 3 days) CSCC163768: 0.012 lb/A (0-15 cm; 3 days) CSAA806573: 0.004 lb/A (0-15 cm; 1 day)

Iowa

Clarion soil series Sandy loam
pH 7.4 Transformation to SYN503780 Soil Bicyclopyrone: 0.141 lb/A (0-15 cm; day 0) SYN503780: 0.040 lb/A (0-15 cm; 3 and 7 days)

Nebraska Hastings soil series

Silt loam
pH 7.3 Transformation to SYN503780 Soil Bicyclopyrone: 0.105 lb/A (0-15 cm; day 0) SYN503780: 0.027 lb/A (0-15 cm; 1 day) CSAA806573: 0.007 lb/A (0-15 cm; 4 days) CSCD642512: 0.001 lb/A (0-15 cm; 120 days)

Values are reviewer-calculated. Transf ormation products were converted into parent equivalents. Volatilization and run-off were not studied; leaching was not observed.



### Bicyclopyrone residues may move to groundwater via leaching, and may move to surface water bodies via spray drift and runoff of dissolved or (to a lesser exte nt) sediment-sorbed/associated residues (erosion). In aerobic soil metabolism studies cond ucted on two of the transformation products (rather than on parent), each was found to be non-persistent in aerobic soil, with halflives of 4.7-7.1 days for SYN503780 and <1 day for CSAA806573 (MRIDs 47843036, 47843037). Laboratory metabolism and fi eld studies also showed in general that persistence in the environment is not an expected issue for these transformation products. However, in prospective groundwater studies conducted in Europe following parent bicyclopyrone application, SYN503780 was detected in well s at sampling intervals up to 3 years after-Page 21 of 88- 

### application (MRIDs 47842066, 47842067, 47842068, 47842069).

Based on its hydrophilicity (Log K ow 

### of -1.2 at pH 7), bicycl opyrone is not expected to bioaccumulate in aquatic or terrestrial organisms. Table 3.3 summarizes the physical/chemical properties of bicyclopyrone as reported by the registrant and based upon submitted environmental fate studies on the pesticide.

Table 3.3. Chemical properties and environmental fate para meters of bicyclopyrone.

Chemical

Fate/Parameter Value Study

Classification Source (MRID)/Comments

IUPAC Name 4-hydroxy-3-[2-(2-methoxyethoxymethyl)-6- trifluoromethyl-pyridine-3- carbonyl]-bicyclo[3.2.1]oct-3-

en-2-one ̶

Chemical Formula C 19 H 20 F 3 NO 5 ̶

Chemical Structure O CF 3 N O OH O OMe

̶

Molecular Mass (g/mol) 399.36 g/mole (C 19 H 20 F 3 NO 5 )

̶ Registrant-submitted phys/chem property values.

Vapor Pressure (25°C) (Torr) 3.75 x 10 -8

̶ Registrant-submitted phys/chem property values (converted from 5

· 10 -6 Pa).

Henry’s Law Constant (atm-m 3 /mol; pH 7.2) 1.67 x 10 -13

̶ Registrant-submitted phys/chem property values (converted from

1.7

. 10 -8 Pa m3/mol)

Solubility (20°C) (ppm) Pure water: 1.2 g/l (a pH of about 3 was recorded)
Aqueous sol.: 38 g/L at pH 4.9 Aqueous sol.: 119 g/L at pH 7.2 Aqueous sol.: 119 g/L at pH 9.2 ̶ Registrant-submitted phys/chem property values.

Octanol-water partition coefficient at 25°C (log

K
ow ) At pH 5 log K

ow = 0.25 At pH 7 log K

ow = -1.2 At pH 9 log K

ow = -1.9 ̶ Registrant-submitted phys/chem property values.

Acid Dissociation Constant (pK

a ) at 20  C 3.06

̶ Registrant-submitted phys/chem property values. Hydrolysis half-life (pHs 5,7,9; 50 °C) Stable at pH 4, 5, 7, 9 Acceptable MR ID 47841919

Aqueous photolysis

half-life 11.1 days @ pH 5 50.1 days @ pH7 74.8 days in natural water @ pH

7.3 Supplemental MRID 47841921

Soil photolysis half-life 4.4, 5.2, 13.3 days Supplemental MRID 47842029-Page 22 of 88- Chemical

Fate/Parameter Value Study

Classification Source (MRID)/Comments

Aerobic soil

metabolism half-life (20  C) 19.8 1 days (same soil as in study below) Acceptable MR ID 47842026

350, 157, 331, 110, 335, 141, 59.1 days Acceptable MR ID 47842033

53.5, 21.8 1 (same soil as in study above), 266, 89, 68.4 days Acceptable MR ID 47842034

307, 81.9, 434, 148 days (Brazilian soils; values will not

be used in this assessment) Supplemental MRID 47842035

Not parent ; for metabolite

SYN503780 : 4.7, 5.2, 7.1 days Supplemental MRID 47843036

Not parent ; for metabolite

CSAA806573 : <1 day (three soils) Supplemental MRID 47843037

Anaerobic soil

metabolism half-life (20  C) Stable (half-life not calculated; no degradation during anaerobic phase) Acceptable MR ID 47842027

Aerobic aquatic

metabolism half-life (20  C) 681, 393 days (2 systems) Acceptable MR ID 47842073

661, 466 days (2 systems) Acceptable MR ID 47842074

*NON-GUIDELINE* Aerobic aquatic

metabolism with irradiation (metabolism + photodegradation) half-life (20  C) 7.4, 7.5 days (2 systems) MRID 47842075

Anaerobic aquatic

metabolism half-life (20  C) 1423, 6244 (stable; 2 systems) Supplemental MRID 47842073

1159, 2077 (stable; 2 systems) Supplemental MRID 47842074

Freundlich soil-water partition coefficients (K F ); Freundlichorganic carbonnormalized coefficients (K FOC ) Parent Bicyclopyrone

K F : 0.24, 0.83, 0.37, 0.45, 1.39, 0.22, 0.35 L/kg

K FOC : 39, 35, 31, 11, 32, 28, 7 L/kg Acceptable MR ID 47842055

Parent Bicyclopyrone

K F : 1.34, 0.25, 0.20, 0.14, 1.39 L/kg

K FOC : 46, 18, 10, 14, 87 L/kg Acceptable MR ID 47842056

Parent Bicyclopyrone

K F : 0.32, 1.74 L/kg

K FOC : 29, 103 L/kg Acceptable MR ID 47842057-Page 23 of 88- Chemical

Fate/Parameter Value Study

Classification Source (MRID)/Comments

Parent Bicyclopyrone

K F : 0.11, 0.48, 0.29, 0.13, 0.91 L/kg

K FOC : 7, 24, 59, 11, 61 L/kg Acceptable MR ID 47842059

Parent Bicyclopyrone (Brazilian soils)

K F : 1.1, 6.3, 2.2, 26.6 L/kg

K FOC : 46, 352, 241, 264 L/kg Supplemental MRID 47842058

Degradate CSCC163768

K F : 0.03, 0.08 L/kg

K FOC : 2.8, 3.4 L/kg

Values could not be determined due to lack of adsorption in two

additional soils. Acceptable MR ID 47842062

Degradate SYN503780

Values could not be determined

due to lack of adsorption (4 soils). Acceptable MR ID 47842060

Degradate CSAA806573

No values determined due to lack of adsorption (4 soils). Acceptable MR ID 47842061

Degradate CSCD656832

K F : 5.2, 38.9, 51.8, 98.9 L/kg

K FOC : 247, 1340, 5179, 6180 L/kg Acceptable MR ID 47842155

Terrestrial field dissipation half-life (bare soil; simulated corn use conditions) 2 4.4 days GA Accepta ble MRID 47842038 5.0 days IA Accepta ble MRID 47842039

1.7 days NE Accepta ble MRID 47842040

1 The same soil was used in two studies. To prevent double-coun ting when determining the input values for mode ling, the mean of these two (i.e., 20.8 days) is used to represent this soil rather than the two individual half-lives. 2 Reported in the table only for fully reliable, domestic studies. In eight of the reviewed TFD studies (not all fo reign studies were re viewed) conducted in Europe, half-lives were determin ed to be 3.52, 5.9, 10.6, 20.3, 31.5, 36.0, 24.6, and 3.6 days.



### Microbial degradation in aerobic soil and photodegradation in soil are likely to be the main pathways by which the compound transforms in the environment.-Page 24 of 88- 

### Major transformation products of bicyclopyrone include:

 CSCC163768 6-(trifluoromethyl)pyr idine-2,3-dicarboxylic acid

 SYN503780 (or CSAA794148) 2-(2-methoxy-ethoxyme thyl)-6-trifluoromethyl-nicotinic

acid

 CSCD656832 3-hydroxy-6-(trifluoromethyl )pyridine-2-carboxylic acid

 CSCD642512 2-[[3-(2,4-dioxobicyclo[3.2.1]octane -3-carbonyl)-6-(trifluoromethyl)-2- pyridyl]methoxy]acetic acid

 CSAA589691 (1S,3R)-cyclopent ane-1,3-dica rboxylic acid

 carbon dioxide.

Minor transformation products of bicyclopyrone include:

 CSAA806573 2-hydroxymethyl-6-trifluor omethyl-nicotinic acid

 CSAA915194 4-hydroxy-3-[2-(2- hydroxy-ethoxymethyl)-6-trifl uoromethyl-pyridine-3- carbonyl]-bicyclo[3.2.1] oct-3-en-2-one.

A transformation product detected on ly in a single non-guideline study ( i.e ., the aerobic aquatic metabolism study conducted w ith irradiation) was:

 CSAA456156 6-trifluoro-methyl -pyridine-3-carboxylic acid.

Chemical structures, physical/chemical prope rties, and a summary of maximum and final detections of the degradates in the fate studies are provided in Appendix B.

To determine the potential for groundwater contamination, multiple Prospective Groundwater Studies (OCSPP 835.7100 8 

### ) conducted in Europe were submitted to demonstrate the leaching of the compound in the field. A review of the studi es indicated that they are reliable, but with restrictions ( i.e ., classified supplemental). All of the (E uropean) studies had deficiencies relative to OCSPP 835.7100 guidance, such as using multiple rather than single applications, not installing wells in clusters, not screening at two soil depths, pl acing wells outside the perimeter of the test plot, insufficient water inputs, and not collecting soil samples and soil-pore water samples. None of the studies were conducted in the U.S. and all applications were made early post-emergence. Each of the studies is discussed below.

In a study conducted in Germany, bicyclopyrone was broadcast ap plied as an emulsifiable concentrate (EC) formulation (A15749E/A15749F, c ontaining nominal 150 g a.i./L) at a nominal

rate of 0.18 lb a.i./A (equivalent to 200 g a. i./ha or 4 times the cu rrent proposed maximum application rate) annually from May 2007 to 2011 (MRID 47842066). Residues of bicyclopyrone were measured in all eight of the down-gradien t wells studied. All we lls were between 3.37 and 3.93 m deep. Residues above the level of quantification (LOQ = 0.01 μg/L) were first observed (0.04 μg/L) in wells closer to th e point of applicati on at 336-904 days post -treatment, and were observed in all down-gradient wells by 1247 days post-treatment. Residues of bicyclopyrone

8 USEPA. 2008. Fate, Transport and Transformation Test Guid elines. OCSPP 835.7100: Guidance for Prospective Ground-Water Mon itoring Studies. Office of Chemical Safety and Pollution Prevention (OCSPP) formerly the Office of Prevention, Pesticides and Toxic Sub stances (OPPTS) (7101) EPA 712-B-10-001. August 25, 2008. http://www.regulations.gov/#!documen tDetail;D=EPA-HQ- OPPT-2009-0152-0044-Page 25 of 88- 

### generally increased in all down-gradient wells throughou t the study period, with maximum concentrations detected in each well ranging fr om 0.06 to 1.4 μg/L, and residues still detected at 1478-1629 days post-treatment. Bicy clopyrone was not detected a bove the LOQ in up-gradient wells, with the exception of tr ace concentrations (0.01-0.02 μg/L ) in one well following a wet summer period, and trace concentr ations (0.02-0.09 μg/L) in two other wells following a dry spring. The transformation product SYN503780 was first detected in various down-gradient wells at 966 days (1 well), 1111 days (1 well ), and 1399-1428 days (4 wells) days; residues were not detected above the LOQ in two wells during the study period. Maximum observed

SYN503780 concentrations in water from wells B3 -B8 were as follows: 0.04-0.11 μg/L at 1189- 1629 days. Residues of SYN503780 generally increas ed during the study period in one well to a maximum concentration (0.11 μg/L) at 1601-1629 da ys, and appeared to peak and decline to <LOQ (0.01 μg/L) in two other wells. A clear pattern of increase followed by decline was not observed in the other down-gradient wells. Resi dues of SYN503780 were not detected above the LOQ in any of the six up-gradient wells.

In a study conducted in Hungary, bi cyclopyrone was first detected in a shallow, down-gradient well at 0.02 μg/L at 726 days af ter the initial applica tion, and was first dete cted in three other wells at 811-848 days (MRID 47842067) . Bicyclopyrone was detected in one well at a maximum concentration of 0.24 μg/L at 848 days and declined to <LOQ ( 0.01 μg/L) by 1069 days. Bicyclopyrone was detected in two wells at ≤ 0.02 μg/Land had declined to <LOQ by 1134-1169 days. Bicyclopyrone was not detected above th e LOQ (0.01 μg/L) in the other seven wells studied. The only three monitoring wells with consistent detecti ons of bicyclopyrone at >LOQ were all located down-gradient; however, bicycl opyrone was not detected above the LOQ in the pair of wells located directly down-gradient of the prevaili ng groundwater flow direction. Residues of the transformation product SYN503780 were not detected above the LOQ (0.01 μg/L) in any wells.

In a study conducted in France, residues of bicyclopyrone were only measured in four well clusters located down-gradient (MRID 47842068). Bi cyclopyrone was first detected in each of the four shallow down-gradient wells at 306-9 51 days post-treatment and was a maximum of 0.07 μg/L at 740 and 1195 days. Bicyclopyrone was first detected in each of the four downgradient deep wells at 404-951 days post-treatment, was a ma ximum of 0.11 μg/L at 951 days

and was ≤ 0.06 μg/L at 1245 days post-treatment (resid ues detected in thr ee shallow wells and two deep wells). The transformation product SYN503780 was generally only detected in one down-gradient well cluster, with residues first ob served at the LOQ (0.01 μg/L) in both shallow and deep wells at 404-434 days , and residues detect ed at a maximum of 0.03 μg/L at 1043, 1103, and 1131 days in the shallow well. The tran sformation product SYN503780 was also detected once each in two shallow wells at the LOQ ( 0.01 μg/L; 740 and 951 days), and was detected twice in a deep well (at 9 51-986 days) at 0.01-0.02 μg/L.

In a study conducted in Italy (MRID 47842069), bicyclopyrone was first observed in all six studied down-gradient wells between 188 and 353 days post-treatment. Bicyclopyrone residues were detected in separate wells at maxima of 0.04-0.34 μ g/L (589-1053 days). Bicyclopyrone decreased to <LOQ (0.01 μg/L) by 836-1233 days post-treatment in three wells, and was 0.05-

0.13 μ g/L in the other three stud ied wells by the end of th e study (1254 days). The transformation product SYN503780 was initially detect ed in three of the down-gradient wells at-Page 26 of 88- 

### the LOQ (0.01 μg/L) at 188-234 days, and was not detected at ≥ LOQ in the remaining three down-gradient wells until 553-713 days. SYN 503780 was detected in two wells at a maximum of 0.02 μg/L (713-746 days) and declined to <LOQ by 776-868. In two other wells, maximum SYN503780 concentrations were 0.12-0.15 μg/L (776 days) and declined to <LOQ (0.01 μg/L) by 953-986 days. In two wells, SYN503780 residue s were a maximum at 0.17 μg/L (807-868 days) and declined to ≤ 0.03 μg/L by the end of the study (1254 days).

3.2.2. Aquatic Exposure

Screening-level modeling was conducted to gene rate EECs of bicyclopyrone in surface and groundwater following a 7-day pre- emergent application on corn. Surface water modeling was conducted using SWCC with an application rate of 0.045 lb a.i./A, applied in a single ground spray application. Physical/chemical propertie s and environmental fate source data (from submitted studies) are presented in Table 3.3. Input fate parameters used in surface water modeling with SWCC are presented in Table 3.4. Scenarios modeled with SWCC are indicated

in Table 3.5 . Bare-ground applications were modeled wi th the soil incorpor ation depth set to 0

cm.

EECs for bicyclopyrone in groundwater used for irrigation purposes were generated based on maximum labeled use rates and fate input para meters, developed using current EFED Input

Parameter Guidance 9 

### and EFED standard models.

EECs in groundwater were also estimated using EFED’s groundwater m odel SCI-GROW. Input parameter values used for groundwater m odeling with SCI-GROW are presented in Table 3.6. The output of SCI-GROW represents concentrations that might be expected to occur in shallow unconfined aquifers under sandy soils, which is representative of the groundwater most vulnerable to pesticide contamination.

Groundwater EECs for bicyclopyrone were deri ved using the PRZM-GW model with the GWGUI. In PRZM-GW simulations, each of these st andard scenarios was used. Input parameter values used for groundwater modelin g with PRZM-GW are presented in Table 3.7 . PRZM-GW output represents pesticide concentrations in vul nerable groundwater locate d directly beneath an agricultural field, following many ye ars of pesticide application.

Table 3.4. Input values for the SWCC model for bicyclopyrone 1

. Input Parameter Value Source/comment

Molecular weight (g/mol) 399.36 g/mol Registrant-submitted phys/chem property

values.

Vapor pressure (Torr @ 25 oC) 3.75 x 10 -8 Registrant-submitted phys/chem property values (converted from 5

· 10 -6 Pa).

Solubility in water (mg/L @ 20oC; pH 7.2) 119,000 Registrant-submitted phys/chem property

values.

Henry’s Law Constant (atmm 3 /mol; pH 7.2) 1.67 x 10 -13 Registrant-submitted phys/chem property

values (converted from 1.7

. 10 -8 Pa m3/mol).

9 http://www.epa.gov/oppefed1/models/w ater/input_parameter_guidance.htm-Page 27 of 88- Input Parameter Value Source/comment

Hydrolysis half-life (t 1⁄2 in days; pH 7) Stable MRID 47841919

Aqueous Photolysis half-life (t 1⁄2 in days; pH 7) 50.1 MRID 47841921

Aerobic Soil metabolism half-life (t 1⁄2 in days) 213.2 MRIDs 47842026, 47842033, 47842034 Represents the 90 th percentile confidence

bound on the mean of 12 half-lives (mean = 165, SD = 122.14)

Anaerobic aquatic metabolism half-life (t 1⁄2 in days) stable MRIDs 47842073, 47842074

Aerobic Aquatic metabolism half-life (t 1⁄2 in days) 667.2 MRIDs 47842073, 47842074 Represents the 90 th percentile confidence

bound on the mean of 4 half-lives (mean = 550, SD = 142.81)

Soil partition coefficient K FD (mL/g

oc ) 0.59 MRIDs 47842055, 47842056, 47842057,

47842059

Mean K d (mean of 19 K d values; ionic compound; adsorption not correlated with K

oc )

1 EFED input parameter gu idance is located at: http://www.epa.gov/oppefed1/models/wat er/input_parameter_guidance.htm

Table 3.5. SWCC scenarios and i nputs for bicyclopyrone modeling

Use SWCC Scenario Applic. Rate (lbs a.i./A) Applic. Dates Comments

Corn CA_corn IA_corn IL_Corn IN_Corn KS_Corn MN_Corn MS_corn NC_cornE NC_cornW

ND_corn NE_Corn OH_Corn PA_corn STX_corn TX_corn 0.045 (0.05 kg/Ha) Applied 7 days

pre-emergence Single, pre-emergence application to soil surface by ground

spray.

Table 3.6. Input Values for the SC I-GROW model for bicyclopyrone.

Variable Name Data Value Data Source MRID(s) Comment

Application Rate (lbs. a.i./A/application) 0.045 Label

̶

Application Frequency (1/yr) 1 Label

̶

Aerobic Soil Metabolism Half-life (days) 125.5 MRIDs 47842026, 47842033,

47842034 Represents the median of 12

aerobic soil metabolism halflife values. 1-Page 28 of 88- Variable Name Data Value Data Source MRID(s) Comment

K FOC (mL/g

oc ) 7 MRIDs 47842055, 47842056, 47842057,

47842059 Lowest of 19 values (since there is >three-fold variation) 1

1 EFED input parameter gu idance is located at: http://www.epa.gov/oppefed1/models/wat er/input_parameter_guidance.htm

Table 3.7. Input values for the PRZM-GW model for bicyclopyrone.

Variable Name Data Value Data Source MRID(s) Comment

Application Method Ground spray Label

Application Date 7 days pre-emergence Label Single, pre-emergence application to soil.

Application Rate (lbs. a.i./acre) [kg/ha] 0.045 [0.05] Label

Application Frequency 1 Label

Application Interval (days) NA

Hydrolysis Half-life (days; pH 7.2) stable MRID

47841919

Aerobic Soil Metabolism Half-life (days) 213.2 MRIDs 47842026, 47842033,

47842034 Represents the 90

percent upper
confidence limit on

the mean of 12

aerobic soil

metabolism half-life

values.

K FD (mL/g) 0.59 MRIDs 47842055, 47842056, 47842057,

47842059 Mean of 19 K FD values (ionic compound; adsorption

not correlated with

K
oc )

1 EFED input parameter guidance: http://www.epa.gov/oppefed1/models/water/p rzm_gw/wqtt_przm_gw _input_guidance.htm



### The EECs in Table 3.8 reflect the 1-in-10 year peak, 21-day and 60-day surface water

concentrations. The SWCC modeled concentrati ons (μg/L) represent untreated surface water. The scenario with the maximum EEC (NE Corn) is bolded . The selected crop-specific scenarios are standard Agency-developed scenarios. Output files for SW CC are provided in Appendix C

. Groundwater EECs are presented in Table 3.9. The SCI-GROW and PRZM-GW concentrations represent groundwater concentratio ns that might be expected in shallow, unconfined aquifers under sandy soils. Output files for the tw o groundwater models are provided in Appendix D . Of the two groundwater models, PRZM-GW estimated the highest residues based on Wisconsin central sands. To achieve breakthrough, an ex tended weather file of 100 years was used, as breakthrough to groundwater di d not occur using the sta ndard 30-yr modeling run.-Page 29 of 88- Table 3.8. Estimated environmental concentr ations for bicyclopyrone use on corn.

Crop Scenario Acute (1-in-10- yr; ppb) 21-day average (1- in-10-yr; ppb) 60-day average (1- in-10-yr; ppb)

Corn CA_corn 0.86 0.85 0.84

IA_corn 1.03 1.03 1.03

IL_Corn 1.98 1.96 1.92

IN_Corn 2.25 2.26 2.28

KS_Corn 3.11 3.09 3.03

MN_Corn 1.92 1.91 1.88

MS_corn 3.63 3.6 3.58

NC_cornE 0.92 0.93 0.94

NC_cornW 0.96 0.95 0.93

ND_corn 1.65 1.65 1.65

NE_Corn 4.04 4.01 3.92

OH_Corn 2.02 2 1.97

PA_corn 0.95 0.94 0.95

STX_corn 2.24 2.21 2.15

TX_corn 1.03 1.01 0.99

Table 3.9. PRZM-GW and SCI-GROW groundwa ter EECs for bicyclopyrone use on corn.

Model Crop Scenario Highest Daily

Value ( μ g/L) Post Breakthrough Average

( μ g/L) Average

Simulation Breakthrough

Time (days)

PRZM-GW Corn WI Central Sands/Corn 7.95 7.33 12,079

SCI-GROW Corn NA 1.32 NA NA



### 3.2.3. Terrestrial Exposure

The proposed application of bicyclopyrone to crops has the potential to reach non-target terrestrial organisms via spray dr ift and runoff (for plants) and whic h may settle on plants and/or be taken up by plants as a result of systemic uptake and distributi on. For terrestrial animals, TREX (version 1.5.2) is used to ca lculate dietary- and dose-bas ed EECs of bicyclopyrone for mammals and birds feeding on the site of appli cation. EECs are considered worst case and may be lower for split applications. Input values for T-REX include the maximum single application rates, number of applications, and retreatment interval for a given use and are located in Table

3.1 . In this assessment, EFED uses a default foliar dissipation half-life of 35 days as an input for terrestrial exposure modeling in T-REX. The default value is generally consistent with

information from residue decline studies subm itted by the registrant and reviewed by the EPA Office of Pesticide Programs’ Health Effect s Division (HED; Global Joint Review Monograph B.7.6 Residues resulting from supervised tria ls [Annex IIA 6.3; Annex IIIA 8.3], 2011). Dietary- and dose-based exposure estimates from application of bicyclopyrone are presented in

Table 3.10 ; output from T-REX is presented in Appendix G

.-Page 30 of 88-Table 3.10. Terrestrial EECs as food residues for animals exposed to bicyclopyrone asa result of the proposed pre-emergent use.Food TypeChronic DietaryBased(mg/kg diet)(mammals andbirds)Dose Based(mg/kg bw)(birds)Dose Based(mg/kg bw)(mammals)All Size ClassesSmall(20 g)Medium(100 g)Large(1000 g)Small(15 g)Medium(35 g)Large(1000 g)Corn; 0.045 lbs a.i./A; 1 applicationShort grass 10.2 11.6 6.6 3.0 9.7 6.7 1.6Tall grass 4.7 5.3 3.0 1.4 4.5 3.1 0.7Broadleaf plants/small insects 5.7 6.5 3.7 1.7 5.5 3.8 0.9Fruits/pods/large insects 0.6 0.7 0.4 0.2 0.6 0.4 0.1Arthropods 4.0 4.6 2.6 1.2 3.8 2.6 0.6Seeds (granivore) NA 0.2 0.1 0.0 0.1 0.1 0.0N/ANot applicable.-Page 31 of 88- 

### TerrPlant is used to calculate EEC s for non-target plants that inha bit dry and semi-aquatic areas. In this assessment, EECs for non- target plants are calculated based on the potential runoff and spray drift of pre-emergent ap plications of bicyclopyrone ( Table 3.11 ). TerrPlant does not account for particulate drift ( Appendix H ).

Table 3.11. EECs for non-target terres trial and semi-aquatic plants based on proposed use of bicyclopyrone (TerrPlant).

Use(s) Application Technique Single Max. App. Rate (lbs a.i./A) EECs (lbs a.i./A)

Semi-Aquatic Areas (Total) Spray

Drift Dry

Areas (Total)

Corn Ground spray 0.045 0.023 <0.001 0.003

App. - Application. Max. - Maximum. N/A - Not applicable.



### To estimate exposure ( i.e. , EEC) to plants when groundwater contaminated with bicyclopyrone is applied to crops (irrigation water), EFED made the assumption that a field is irrigated with one inch of water containing resi dues. One acre has 6,272,640 cubic inch es of water on the field.

The 1-acre field with 1 inch of water ha s 3,630 cubic ft of water (6,272,640 x 0.00058 cubic ft/cubic inch). The field has 27,156 gallons of water (3,630 cubic ft x 7.481 gallons/cubic ft). Therefore, 1 inch of water on the 1-acre field weighs 226,625 lbs (27,156 gallons x 8.3453 lbs/gallon of water). Using the maximum peak estimate of bicyclopyrone in groundwater from PRZM-GW (7.95 μg a.i./L) and based on the preceding assumptions, the EEC in terms of application rate (loading) is:

226,625 lb of water/acre x 7.95 μg /L = EEC = 0.0018 lbs a.i./A 1,000,000,000

Compared to EECs generated using TerrPlant , estimated residues in groundwater-derived irrigation water are roughly half those estimated for dry areas for runoff and spray drift combined ( i.e ., 0.003 lbs ai/A) and are 13 times lower that EECs estimated for semi-aquatic

areas.

3.3. Ecological Effects Characterization

3.3.1. Ecotoxicity Data

Toxicity endpoints used in risk estimation a nd characterization for the proposed new use of bicyclopyrone are shown in Table 3.12 through Table 3.19 . In the current risk assessment, the most sensitive endpoints available from regist rant-submitted toxicity st udies classified as acceptable or supplemental are the endpoints select ed for quantitative use in risk estimation 10



### .

10 Only studies classified as “Supplemental” for quantitative use are used for risk quotient calculations in EFED assessments; su pplemental studies that are not deemed useful for quantifying ri sks are used for risk characterization purposes only.-Page 32 of 88- 

### As previously stated in Section 3.1 , bicyclopyrone will be contained in one of two proposed products, a soluble concentrate (SC; 18.1% a. i.; SYN-A16003 Herbicide; EPA Reg. No. 100- RUAA), and a Restricted Use product consisting of a mixed formulation of a capsule suspension and suspension concentrate (CS and SC; 0.65% a.i.; SYN-A19707 Herb icide; EPA Reg. No. 100-RUAL). In the RUP, bicyclopyrone will be co-formulated with the other active ingredients mesotrione, atrazine, and S-metolachlor. The Ca nadian registration is for both products, while the Australian registration is for the SC only. As noted earlier, mesotrione has a common mode

of action as bicyclopyrone, i.e. , HPPD inhibition. However, eco toxicity data were not submitted for the restricted use product.

3.3.1.1. Aquatic Organisms

Acute toxicity data for fish and aq uatic invertebrates are summarized in Table 3.12 and Table

3.13 . Based on the available data, bicyclopyrone technical grade active ingredient (NOA449280 TGAI) is classified as pr actically non-toxic to the fr eshwater rainbow trout ( Oncorhynchus mykiss ) and fathead minnows ( Pimephales promelas ), and to the estuarine/marine sheepshead minnows ( Cyprinodon variegatus ) on an acute exposure basis. For all of the freshwater and estuarine/marine fish tested (as well as aquati c-phase amphibians for which freshwater fish serve as surrogates), the acute 96-hr LC 50 

### value exceeded the highest concentration tested, i.e , the acute toxicity estimates were non-definitive values at or close to the limit test concentration of 100 mg a.i./L. Bicyclopyrone is practically non-toxic to the freshwater inve rtebrate water flea ( Daphnia magna ) and yielded a non-de finitive endpoint (EC 50 

### >93.3 mg a.i./L); however, the compound is moderately toxic to estuarine/marine mysid shrimp ( Americamysis bahia ) and the Eastern oyster ( Crassostrea virginica ) on an acute exposure basis. The mysid shrimp was the

most sensitive estuarine/marine invertebrate with an LC 50 

### of 3.4 mg a.i./L. The solubility limit of bicyclopyrone (119 g/L at 20 °C) may be an important consideration in determining the toxicity classifications for non-definitive endpoints.

Two acute toxicity tests were also carried out with the bicyclopyrone end-use formulation A16003E (containing 18.3% NOA449280 w/w) indicating that the formulation is slightly toxic

to rainbow trout and D. magna on an acute exposure basis alt hough for both species, the toxicity

estimates were also non-definitive and were conducted to the limit test concentration of the formulation, i.e. , the LC 50 

### was >18.6 and 19.0 mg formulation/L for the rainbow trout and D.

magna , respectively. However, it should be noted that acute toxicity tests with the formulation were not carried out with mysid shrimp or East ern oyster, which are the most sensitive aquatic animals to bicyclopyrone TGAI.

Toxicity endpoints for aquatic pl ants exposed to bicyclopyrone and its formulations are shown in

Table 3.14 . The freshwater vascular plant duckweed ( Lemna gibba ) was exposed to bicyclopyrone TGAI (MRID 47842095) over a 7-day period; the EC 50 

### was determined to be 0.013 mg a.i./L based on inhibition of frond yield. The empirical NOAEC in this study was determined to be 0.0032 mg a.i./L.

The effects of bicyclopyrone TGAI (MRID 47842092) on the growth of the freshwater green alga (nonvascular plant), Pseudokirchnerie lla subcapitata , were tested; the 96-hour EC 50 

### and empirical NOAEC were determined to be nomi nal concentrations of 2.4 and 1.0 mg a.i./L,-Page 33 of 88- 

### respectively, based on decreased yield. Exposure of blue-green alga ( Anabaena flos-aquae ; MRID 47842093) to TGAI resulted in a 96-hour EC 50 

### and empirical NOAEC of >94.8 and 94.8 mg a.i./L, respectively, based on mean-measured test concentrations; therefore, at the exposure concentrations tested, bicyclopyr one TGAI had no inhibitory effect on the growth of the bluegreen alga. It should be noted the >94.8 mg a.i./L test concen tration is the highest (limit) concentration in aquatic pl ant toxicity tests.

The effects of bicyclopyrone TGAI on the toxicity to the freshwater diatom ( Navicula pelliculosa ; MRID 47842094) were tested; the 96-hour EC 50 

### and empirical NOAEC were determined to be 9.8 and 2.39 mg a.i./L , respectively, based on mean-measured test concentrations and decreases in yield. The eff ects of bicyclopyrone TGAI on the toxicity to the marine diatom ( Skeletonema costatum ); MRID 47842102) were tested; the 96-hour EC 50 

### and empirical NOAEC were determined to be 2.8 a nd 1.6 mg a.i./L, respec tively, based on meanmeasured test concentrations and decreased yield.

Two bicyclopyrone end-use products were tested on duckweed and green algae. Formulation A15749AD (150 g NOA449280/L EC formulation; 14.1% w/w a.i.) was tested on duckweed resulting in an EC 50 

### and empirical NOAEC of 0.016 and 0.004 mg a.i./L, respectively, in a 7-day test (MRID 47842116). The most sensitive endpoint in that test was decreased biomass (dry weight yield). Formulation A16003E (end-us e product of NOA449280 18.3% w/w) was tested on green algae resulting in an EC 50 

### and empirical NOAEC of 2.0 and 0.59 mg a.i./L, respectively, in a 96-hour test with the most sensit ive endpoint being decreased yield (MRID 47842243).

The effects of two transformation products of bicyclopyrone (MRIDs 47842149 and 47842139) were also tested on duckweed in a 7-day test. The two transformation products were CSAA589691 (metabolite of NOA449280; 85% pure) and CSCC163768 (metabolite of NOA449280; 98% pure). The EC 50 

### using CSAA589691 was >0.09 mg a.i./L and the EC 50 

### using CSCC163768 was >100 mg a.i./L. Given that the EC 50 

### of TGAI bicyclopyrone (94.5% a.i.) for duckweed was 0.013 mg a.i./L, the da ta on the two degradates indi cate that they are less toxic than the parent compound.-Page 34 of 88-Table 3.12. Acute toxicity endpoints usedin risk estimation and characterization for freshwaterorganisms exposed to bicyclopyrone.Study TypeSpeciesTest MaterialEndpoints(mg a.i./L)(Study Duration)Toxicity Classification (MRID)(Study Classification)Acute toxicity tofreshwater vertebratesRainbow trout(Oncorhynchus mykiss)NOA449280 TGAI(94.5%)LC50>93.7 mg a.i./L(96 hour test)Practically non-toxic(47842085)(Acceptable)A16003E(end-use product ofNOA449280 18.3% w/w)LC50>18.6 mg a.i./L(96-hour limit test)Slightly toxic(47842241)(Acceptable)Fathead minnow(Pimephales promelas)NOA449280 TGAI(94.5%)LC50>93.4 mg a.i./L(96 hour test)Practically non-toxic(47842086)(Acceptable)Acute toxicity tofreshwater invertebratesWater flea(Daphnia magna)NOA449280 TGAI(94.5%)EC50>93.3 mg a.i./L(48-hour test)Practically non-toxic(47842088)(Acceptable)A16003E(end-use product ofNOA449280 18.3% w/w)EC50>19.0 mg a.i./L(48-hour limit test)Slightly Toxic(47842242)(Acceptable)Table 3.13. Acute toxicity endpoints usedin risk estimation and characterization for estuarine/marine organisms exposed to bicyclopyrone.Study TypeSpeciesTest MaterialEndpoints1(mg a.i./L)(Study Duration)Toxicity Classification (MRID)(Study Classification)Acute toxicity toestuarine/marine fishSheepshead minnow(Cyprinodon variegatus)NOA449280 TGAI(94.5%)LC50> 123 mg a.i./L(96 hour test)Practically non-toxic(47842101)(Supplemental)Acute toxicity toestuarine/marineinvertebratesMysid shrimp(Americamysis bahia)NOA449280 TGAI(94.5%)LC50= 3.4 mg a.i./L(96-hour test)Moderately toxic(47842089)(Acceptable)Toxicity toestuarine/marine mollusks– shell depositionEastern oyster(Crassostrea virginica)NOA449280 TGAI(94.5%)EC50= 37 mg a.i./L(96-hour test)Moderately toxic(47842090)(Acceptable)1Boldedvalues are the most sensitive endpoint(s) for a given taxonomic group and will be used in risk estimation.-Page 35 of 88-Table 3.14. Toxicity endpoints used in risk estimation and characterization for aquatic plants and algae exposed to bicyclopyrone.Study TypeSpeciesTest MaterialEndpoints1(mg a.i./L)Effects(MRID)(Study Classification)Toxicity to vascularaquatic plantsDuckweed(Lemna gibba)NOA449280 TGAI(94.5%)EC50= 0.013 mg a.i./LNOAEC = 0.0032 mg a.i./LLOAEC = 0.010 mg a.i./L(7-day semi-static test)Inhibition of yield(47842095)(Acceptable)A15749AD(150 g NOA449280/L ECformulation; 14.1% w/w ai)EC50= 0.0164 mg a.i./LNOAEC = 0.004 mg a.i./LLOAEC = 0.0126 mg a.i./L(7-day test)Most sensitive endpoint: biomass(known as dry weight yield)(47842116)(Acceptable)CSAA589691(metabolite ofNOA449280; 85% pure)EC50>90.28 mg a.i./LNOAEC = 90.28 mg a.i./L(7-day test)No effect (growth rate and yield)(47842149)(Acceptable)CSCC163768(metabolite ofNOA449280; 98% pure)EC50>100.25 mg a.i./LNOAEC = 100.25 mg a.i./L(7-day test)No effect (growth rate and yield)(47842139)(Acceptable)Toxicity to nonvascularaquatic plantsGreen algae(Pseudokirchneriellasubcapitata)NOA449280 TGAI(94.5%)EC50= 2.4 mg a.i./LNOAEC = 1.0 mg a.i./LLOAEC = 2.0 mg a.i./L(96-hour test)Most sensitive endpoint: yield(47842092)(Acceptable)A16003E(end-use product ofNOA449280 18.3% w/w)EC50= 2.0 mg NOA449280/LNOAEC = 0.59 mg NOA449280/LLOAEC = 1.83 mg NOA449280/L(96-hour test)Most sensitive endpoint: yield(47842243)(Acceptable)Toxicity to blue-greenalgaBlue-green alga (Anabaenaflos-aquae)NOA449280 TGAI(94.5%)EC50>94.8 mg a.i./LNOAEC = 94.8 mg a.i./L(96-hour test)Most sensitive endpoints: growth andyield(47842093)(Acceptable)Toxicity to the freshwaterdiatomFreshwater diatom (Naviculapelliculosa)NOA449280 TGAI(94.5%)EC50= 9.8 mg a.i./LNOAEC = 2.39 mg a.i./LLOAEC = 5.10 mg a.i./L(96-hour test)Most sensitive endpoint: yield(47842094)(Acceptable)Toxicity to the marinediatomMarine diatom (Skeletonemacostatum)NOA449280 TGAI(94.5%)EC50= 2.8 mg a.i./LNOAEC = 1.6 mg a.i./LLOAEC = 3.0 mg a.i./L(96-hour test)Most sensitive endpoint: yield(47842102)(Acceptable)1Boldedvalues are the most sensitive endpoint(s) for a giventaxonomic group and will be used in risk estimation.-Page 36 of 88- 

### Freshwater Fish and In vertebrates: Chronic

Chronic toxicity data for freshwater fish and a quatic invertebrates exposed to bicyclopyrone are

summarized in Table 3.15 . In a 33-day early life-stage t oxicity test with fathead minnows exposed to bicyclopyrone TGAI (MRID 47842087), there were no statistically (p>0.05) or biologically significant e ffects for any measurement endpoint, which included hatchling success, larval survival, and growth yielding a NOAEC of 10 mg a.i./L and a LOAEC >10 mg a.i./L. In a 21-day chronic life-cycle study with D. magna (MRID 47842091), the NOAEC and LOAEC were 103.7 and >103.7 mg a.i./L, respectively. Sim ilar to the chronic endpoints for the fathead minnow, there were no statistically (p>0.05) or biologically significant effects for any measurement endpoint, which included hatch ling success, larval survival, and growth.

Estuarine/Marine Fish and Invertebrates: Chronic

No chronic data have been submitted to the Agency for estuarine/marine fish or invertebrates. Using the available information and assuming the non-definitive endpoints in the acute and

chronic freshwater and estuarine/ marine fish studies are definitive, an ac ute-to-chronic (ACR)

ratio was calculated. Base d on the fathead minnow ( Pimephales promelas ) acute toxicity value of 93.4 mg ai/L and chronic valu e of 10.0 mg ai/L, the ACR is 9.34. Applying this ratio to the estuarine/marine sheepshead minnow ( Cyprinodon variegatus ) acute toxicity value of 123.0 mg ai/L, yields an estimated chronic toxicity end point of 13.2 mg ai/L. Similarly, using the available information and assuming the non-de finitive endpoints in the acute and chronic freshwater and estuarine/marine invertebrate studies are definitive, an ACR value was derived. Based on the water flea ( Daphnia magna ) acute value of 93.3 mg ai/L and chronic NOAEC of 103.7, the ACR is 0.90. Applying this ratio to the estuarine/marine mysid shrimp ( Americamysis

bahia ) acute value of 3.4 mg ai/L re sults in an estimated estuar ine/marine invertebrate NOAEC of 3.7 mg ai/L.-Page 37 of 88-Table 3.15. Chronic toxicityendpoints used in riskestimation and characterization for fish and aquatic invertebrates exposedto bicyclopyrone.Study TypeSpeciesTest MaterialEndpoints1(mg a.i./L)Effects(MRID)(Study Classification)Early life stage toxicity tofreshwater fishFathead minnow(Pimephales promelas)NOA449280 TGAI(94.5%)NOAEC = 10 mg a.i./LLOAEC >10 mg a.i./L(33-day test)None effected (hatching success,larval survival, and growth)(47842087)(Acceptable)Chronic toxicity tofreshwater invertebratesWater flea(Daphnia magna)NOA449280 TGAI(94.5%)NOAEC = 103.7 mg a.i./LLOAEC >103.7 mg a.i./L(21-day test)None effected (hatching success,larval survival, and growth)(47842091)(Acceptable)EstimatedSheepshead minnow(Cyprinodon variegatus)NANOAEC = 13.2 mg a.i./LEstimated using a freshwater acute-to-chronic ratio of 3.4 based onfathead minnow data.EstimatedMysid shrimp(Americamysis bahia)NANOAEC = 3.7 mg a.i./LEstimated using a freshwater acute-to-chronic ratio of 0.90 based onD.magnadata.1Boldedvalues are the most sensitive endpoint(s) for a given taxonomic group and will be used in risk estimation.-Page 38 of 88- 

### 3.3.1.2. Terrestrial Organisms

Birds and Mammals: Acute and Sub-Acute

Acute toxicity data for birds and mammals exposed to bicyclopyrone are summarized in Table

3.16 . Based on the available data, bicyclopyrone is cl assified as slightly-t o-moderately toxic to birds (bobwhite quail, Colinus virginianus ; canary, Serinus canaria ) on an acute oral exposure basis and practically no n-toxic to bobwhite quail and mallard duck ( Anas platyrhynchos ) on a subacute dietary exposure basis. Since birds serv e as a surrogate for terrestrial-phase amphibians and reptiles, bicyclopyrone is classified as moderately toxic on an acute oral exposure basis and practically non-toxic on a subacute dietary exposure basis for these taxa. The avian acute oral toxicity studies with the bobwhite quail and mallard showed signs of sublethal toxicity including ruffled appearance of treated birds, lethargy, loss of coordination, pr ostration, lower limb weakness, and convulsions. An acute oral toxici ty study with the canary resulted in a more

sensitive LD 50 

### (MRID 47842078); however, regurgitati on was observed in the study and mortality was prevalent among birds that that had re gurgitated. Therefore, the study is classified as supplemental and cannot be used for quantitat ive risk assessment purposes. There are no data available describing the effects of any bicyclopyrone formulations to the canary. The subacute studies with the bobwhite quail and mallard ducks provided no ev idence of toxicity at any dietary concentration tested.

The acute oral toxicity of one bicyclopyrone e nd-use product was tested on bobwhite quail. Formulation A16003E (end-use product of NOA 449280 18.3% w/w) was tested resulting in an

LD 50 

### of 425 mg a.i./kg bw in a 14-day test (MRID 47842250) classified as moderately toxic. No regurgitation was observed in any treatment group; however clinical signs of toxicity among treatment groups included ruffled appearance of treated birds, loss of coordination, lethargy, lower limb weakness, and reduced r eaction to external stimuli.

Bicyclopyrone is classified as practically nontoxic to mammals on an acute oral exposure basis. No mortality was observed at the limit dose (5000 mg/kg bw) in an acute oral toxicity study with the rat ( Rattus norvegicus ), which was the most sensitive mammalian species tested; therefore,

the 96-hr LD 50 

### is non-definitive, i.e ., LD 50 

### >5,000 mg a.i./kg bw. HED has concluded that bicyclopyrone exhibits low acute toxicity to mammals by all exposure routes (EPA Toxicity Category III or IV).

Terrestrial Invertebrates

Acute toxicity data for adult honey bees are summarized in Table 3.17 ; however, no data are available for evaluating the effects on adult bees fr om chronic exposure, nor are data available to

evaluate acute or chronic effect s on honey bee larvae. Additiona l non-guideline acute toxicity data on non-target terrestrial arthropods exposed to bicyclopyrone are c onsidered supplemental

information in the current risk assessment and are also summarized in Table 3.17 . Additional non-target arthropods typically not included in current risk asse ssments include the predatory mite ( Typhlodromus pyri) , the parasitoid wasp ( Aphidius rhopalosiphi ), and earthworm ( Eisenia-Page 39 of 88- 

### foetida ) all of which are routine species used in the Organization for Economic Cooperation and Development (OECD) test guidelines.

Bicyclopyrone TGAI and formulation A 16003E (end-use product of NOA449280 18.3% w/w) are practically non-toxic to young adult honey bees on an acute oral and contact exposure basis

with LD 50 

### >200 and 212 μg a.i./bee, respectiv ely (48-hour tests; MRIDs 47842096 and 47842248). The earthworm was exposed to bicy clopyrone TGAI (94.5%) and formulation

A16003E with no observable adverse effects in either study at any of the concentrations tested,

i.e ., LC 50 

### >1000 mg a.i./kg soil (MRIDs 47842098 a nd 47842249). The predatory mite was exposed to formulation A15749AD (150 g NOA 449280/L EC, 14.1% w/w) with no observable adverse effects at any concentration tested, i.e ., LC 50 

### >0.18 lbs a.i./A (47842118). The parasitic wasp was exposed to formulations A15749AD and A15936Z (an EC formulation containing 80 g/L NOA449280 and 400 g/L S-metolachlor). In the study with A15749AD (MRID 47842097) the lethal residue resulting in 50% mortality (LR 50 

### ) was a treatment rate of 0.005 lbs a.i./A based on mortality and decreased reproduction. The study using A15936Z resulted in no observable effects at any concentration tested, i.e ., LR 50 

### >0.179 lbs a.i./A (MRID 47842150).-Page 40 of 88-Table 3.16. Acute toxicity endpoints usedin risk estimation and characterization for birds andmammals exposed to bicyclopyrone.Study TypeSpeciesTest MaterialEndpoints1Toxicity Classification (MRID)(Study Classification)Acute oral toxicity to birdsBobwhite quail(Colinus virginianus)NOA449280 TGAI(94.5%)LD50= 1206 mg a.i./kg bw14-day testSlightly toxic(47842079)(Acceptable)A16003E(end-use product ofNOA449280 18.3%w/w)LD50= 425.11 mg a.i./kg bw(14-day test)Moderately toxic(47842250)(Acceptable)Canary(Serinus canaria)NOA449280 TGAI(94.5%)LD50= 209 mg a.i./kg bw14-day testModerately toxic(47842078)(Supplemental2)Subacute dietary toxicity to birdsBobwhite quail(Colinus virginianus)NOA449280 TGAI(94.5%)LC50>5820mg a.i./kg diet(LD50> 1495 mg/kg bw/day)8-day testPractically non-toxic(47842080)(Acceptable)Mallard duck(Anas platyrhynchos)NOA449280 TGAI(94.5%)LC50>5550 mg/kg diet(LD50>3020 mg/kg bw/day)8-day testPractically non-toxic(47842081)(Acceptable)Acute oral toxicity to mammals3HanRcc:WIST (SPF) rats(Rattus norvegicus)NOA449280 TGAI(94.5%)LD50>5000 mg/kg bwPractically nontoxic(47841966)(Acceptable)1Boldedvalues are the most sensitive endpoint(s) for a given taxonomic group and will be used in risk estimation.2Endpoints cannot be used in risk estimation due to regurgitationin the passerine study. It will be listed as a data gap.3Mammalian toxicity data were reviewed byOPP Health Effects Division (U.S. EPA) as part of the Global Joint Review for bicyclopyrone.Table 3.17. Acute toxicityendpoints used in risk estimationand characterization for terrestrial invertebrates exposed to bicyclopyrone.Study TypeSpeciesTest MaterialEndpoints1Toxicity Classification (MRID)(Study Classification)Acute contact and oral toxicity tohoney beesHoney bee(Apis mellifera)NOA449280 TGAI(94.5%)LD50>200g a.i./bee (contact)LD50>212.2g a.i./bee (oral)(48-hour test)Practically non-toxic (contact)Practically non-toxic (oral)(47842096)(Acceptable)A16003E (end-useproduct ofNOA449280 18.3%w/w)LD50>197.0g a.i./bee (contact)LD50>195.2g a.i./bee (oral)(48-hour test)Practically non-toxic (contact)Practically non-toxic (oral)(47842248)(Acceptable)Acute contact 14-day toxicity toearthwormsEarthworm(Eisenia foetida)NOA449280 TGAI(94.5%)LC50>1000 mg a.i./kg soil(14-day test)NA(47842098)(Supplemental)-Page 41 of 88-Study TypeSpeciesTest MaterialEndpoints1Toxicity Classification (MRID)(Study Classification)A16003E (end-useproduct ofNOA449280 18.3%w/w)LC50>1000 mg a.i./kg soil(14-day test)NA(47842249)(Supplemental)Acute contact 7-day toxicity tothe predatory mitePredatory mite(Typhlodromus pyri)A15749AD (150 gNOA449280/L EC,14.1% w/w)7-d LR50>200 g ai/ha (>0.18 lbs a.i./A)(7-day test)NA(47842118)(Supplemental)Acute contact 48-hr toxicity toparasitic waspParasitic wasp(Aphidius rhopalosiphi)A15749AD (150gNOA449280 /L EC,14.1% w/w)LR50= 6.0 g ai/ha (0.005 lbs a.i./A)(48-hour test)NA(47842097)(Supplemental)A15936Z (an ECformulationcontaining 80 g/LNOA449280 and 400g/L S-metolachlor)LR50>0.179 lbs a.i./A(>200 g a.i./ha)(48-hour test)NA(47842150)(Supplemental)1LR50= Lethal body residues resulting in 50% mortality-Page 42 of 88- 

### 3.3.1. Terrestrial Organism and Ma mmalian Chronic Endpoints

Birds and Mammals: Chronic

Chronic laboratory toxicity data for birds and mammals exposed to bicyclopyrone are

summarized in Table 3.18 . In a 21-week avian reproduction study with bobwhite quail exposed to bicyclopyrone in the diet, th ere was a statistically significan t (5%; p>0.05) decrease in eggs cracked/hen, eggs cracked/eggs la id, hatchlings/egg set, hatchings /live 3-week embryos, and 14- day old survivors/egg set at 640 mg ai/ kg diet (NOAEC/LOAEC 200/640 mg ai/kg diet; 19.1/60.1 mg ai/kg bw; MRID 47842082). In the same study at 2000 mg ai/kg diet reported significant effects included viab le embryos/egg set, live 3-week embryos/viable embryos, and 14-day old survivors/hen.

In a 21-week avian reproduction study with the mallard exposed to bicyclopyrone in the diet, there was a statistically signifi cant (5%; p>0.05) decrease in ha tchlings/live 3-week embryos, 14- day old survivors/hatchling, and 14-day old su rvivors/egg set (NOAEC/LOAEC 70/140 mg ai/kg die; 9.1/17.1 mg ai/kg bw; MRID 47842084).

In both of the avian reproduction studies there was uncer tainty in the biolog ical relevance of some of the measurement endpoints since there was no apparent dose-resp onse relationship. For the bobwhite quail, no dose-response was observe d for mean hatching weight even though a statistically significant effect was detected across multiple dietary treatment levels. Likewise, in the mallard study, no dose-response was observe d for eggs laid/hen and mean 14-day old survivors weight even though a statistically sign ificant effects were detected. Although there was a slight dose-response for mean hatchling weight, the highest bicyclopyrone concentration showed the lowest difference in weight compar ed to controls while the lowest bicyclopyrone concentration had the greatest difference in wei ght. In both avian re production studies there appeared to be considerable variability in cont rol birds making it difficult to detect treatment

effects. Due to these uncer tainties, the studies are clas sified as supplemental.

In a rat 2-generation study evaluated by HED (MRID 47842127) ocular effects, decreases in offspring body weights and weight gains, and reproductive effects were observed. The parental LOAEL was 25 ppm (2.15/2.65 [M/F]) based on ocular effects (cor neal opacity and vascular keratitis P and F1 males) and an increased incidence of pelvic dilation of the kidney (F0 and F1 males and F1 females). Based on decreases (13.4% in males, 11% in female s) in absolute body weights and body weight gains and in increased incidence of litters with vascular keratitis in the F1 and F2 generations, the offspring LOA EL was 500 ppm (43.65/52.7 mg/kg/day [M/F]). The offspring NOAEL was 25 ppm ( 2.15/2.65 mg/kg/day [M/F]). Based on reproductive parameters (changes in sperm parameters i.e., velocity of actual path, straight line velocity, and miscellaneous abnormalities, and a decrease in pr e-coital interval), the reproductive LOAEL is 5000 ppm (435.5/534 mg/kg/day [M/F]) and th e reproductive NOAEL is 500 ppm (43.65/52.7, mg/kg/day [M/F]).-Page 43 of 88-Table 3.18. Chronic toxicityendpoints used in riskestimation and characterization for terrestrial animals exposed to bicyclopyrone.Study TypeSpeciesTest MaterialEndpoints1Effects(MRID)(Study Classification)Avian reproductionBobwhite quail(Colinus virginianus)NOA449280 TGAI(94.5%)NOAEL=19.1 mg a.i./kg bw/day(200 mg a.i./kg diet)LOAEL =60.1 mg a.i./kg bw/day(640 mg a.i./kg diet)21-week testEggs cracked/hen, eggscracked/eggs laid,hatchlings/egg set,hatchings/live 3-weekembryos, and 14-day oldsurvivors/egg set(47842082)(Supplemental)Mallard duck(Anas platyrhynchos)NOA449280 TGAI(94.5%)NOAEL=9.1mg a.i./kg bw/day(70 mg a.i./kg diet)LOAEL = 17.1 mg a.i./kg bw/day(140 mg a.i./kg diet)21-week testHatchlings/live 3-weekembryos, 14-day oldsurvivors/hatchling, and 14-day old survivors/egg set(47842084)(Supplemental)Chronic toxicity to mammals2–two-generation reproductionWistar Han IGS Rat(Crl:WI (Han))(Rattus norvegicus)NOA449280 TGAI(94.5%)NOAEL = 2.15 mg/kg bw/day(25 ppm)LOAEL = 43.65 mg/kg bw/day(500 ppm)Decreases in body weightsand body weight gains;increased vascular keratitisin F1 and F2 generations3(47842127)(Acceptable)1Boldedvalues are the most sensitive endpoint(s) for a given taxonomic group and will be used in risk estimation.2Mammalian toxicity data were reviewed byOPP Health Effects Division (U.S. EPA) as part of the Global Joint Review for bicyclopyrone.3Increased vascular keratitis in F1 and F2 generations was observed in the study but will not be used as the endpoint in risk estimation. Risk estimation will be based on decreases in body weights andbody weight gains.-Page 44 of 88- 

### 3.3.2. Terrestrial Plants

Terrestrial Plant Seedling Em ergence and Vegetative Vigour

Toxicity data for terrestrial plants expos ed to bicyclopyrone formulation A15749F (a NOA449280 EC formulation with 150 g a.i./L) are shown in Table 3.20 . A 21-day seedling emergence study (MRID 47842103) was carried out on eleven terrestrial pl ant species (seven dicotyledonous [dicot] and four monocotyledonous [monocot] species) exposed to A15749F at multiple treatment rates. There were statistical ly significant (p<0.05) inhibitions in biomass for sunflower ( Helianthus annuus ), cucumber ( Cucumis sativa ), and cabbage ( Brassica oleracea ), biomass and height for turnip ( Brassica rapa ) and ryegrass ( Lolium perenne ), and plant survival and shoot height for onion ( Allium cepa ). The most sensitive m onocot was ryegrass with an inhibitory concentration for 25 percent of the plants tested (IC 25 

### ) and NOAEC of 0.073 and 0.067 lbs a.i./A, respectively based on decreased biomass. The most sensitive dicot was cabbage

with an IC 25 

### and NOAEC of 0.005 and 0.002 lbs a.i./A, respectively, based on decreased biomass. The most sensitive seedling emerge nce endpoints for plan t species exposed to bicyclopyrone can be seen in Table 3.20.

Table 3.19. Toxicity endpoints used in risk estimation and characteriza tion for terrestrial and semi-aquatic plants exposed to bicyclopyrone.

Study Type Test Material Most Sensitive Species Endpoints (lbs ai/A) Effects (MRID) (Study Classification)

Terrestrial plant toxicity:

Tier II seedling

emergence A15749F (a

NOA449280

EC formulation

with 150 g

a.i./L) Monocot: ryegrass ( Lolium perenne ) IC 25 = 0.074 lbs a.i./A (82.4 g a.i./ha)

NOAEC = 0.067 lbs a.i./A (75 g a.i./ha)

LOAEC = 0.134 lbs a.i./A (150 g a.i./ha) Biomass (47842103) (Acceptable)

Dicot: cabbage ( Brassica

oleracea ) IC 25 = 0.005 lbs a.i./A (6 g a.i./ha)

NOAEC = 0.002 lbs a.i./A (2.4 g a.i./ha)

LOAEC = 0.004 lbs a.i./A (4.7 g a.i./ha) Biomass (47842103) (Acceptable)

Terrestrial plant toxicity:

Tier II vegetative

vigor A15749F (a

NOA449280

EC formulation

with 150 g

a.i./L) Monocot: onion ( Allium cepa ) IC 25 = 0.02 lbs a.i./A (22.5 g a.i./ha)

NOAEC = 0.017 lbs a.i./A (18.75 g a.i./ha)

LOAEC = 0.03 lbs a.i./A (37.5 g a.i./ha) Biomass (47842104) (Acceptable)

Dicot: sunflower ( Helianthus annus ) IC 25 = 0.001 lbs a.i./A (0.92 g a.i./ha)

NOAEC = 0.0002 lbs a.i./A (0.31 g a.i./ha)

LOAEC = 0.001 lbs a.i./A (0.93 g a.i./ha) Biomass (47842104) (Acceptable)-Page 45 of 88- Table 3.20: Most sensitive 21-day seedling emergence endpoints for plant species exposed to bicyclopyrone

Species Latin name (common name) ER 25 NOER

Relative Sensitivity (g a.i./ha) Most

Sensitive Endpoint NOER (g a.i./ha) Most

Sensitive Endpoint

Zea mays (corn) > 1200 NA 1200 NA

Helianthus annuus (sunflower) 258.75 Height 150 Biomass

Allium cepa (onion) 105.15 Height 150 Survival, Height

Avena sativa (oat) > 150 NA 150 NA

Glycine max (soybean) > 150 NA 150 NA

Cucumis sativa (cucumber) 45.9 Biomass 37.5 Biomass

Lolium perenne (ryegrass) 82.35 Biomass 75 Biomass, Height

Linum usitatissimum (flax) > 75 NA 75 NA

Lycopersicon esculentum (tomato) 29.8 Biomass 37.5 NA

Brassica rapa (turnip) 8.64 Biomass 9.375 Biomass, Height

Brassica oleracea (cabbage) 6 Biomass 2.34 Biomass



### A 21-day vegetative vigour st udy (MRID 47842104) was carried out on eleven terrestrial plant species (seven dicot and four monocot species) exposed to A15749F at multiple treatment rates. There were statistically significant (p< 0.05) inhibitions in biomass for corn ( Zea mays ), sunflower, ryegrass, oats ( Avena sativa ), cucumber, cabbage and turni p. There were statistically significant (p<0.05) inhibitions in plant biom ass and shoot height for onion, and soybean ( Glycine max ), tomato ( Lycopersicon esculentum ), and flax ( Linum usitatissimum ). The most

sensitive monocot was onion with an IC 25 

### and NOAEC of 0.02 and 0.017 lbs a.i./A, respectively

based on decreased biomass. The most se nsitive dicot was sunflower with an IC 25 

### and NOAEC

of 0.001 and 0.0002 lbs a.i./A , respectively, based on decreased plant biomass. The most sensitive seedling emergence endpoints for plant species exposed to bicyclopyrone can be seen

in Table 3.21.-Page 46 of 88- Table 3.21: Most sensitive 21-day vegetative vigor endpoints for plant species exposed to bicyclopyrone

Species Latin name (common name) ER 25 NOER

Relative Sensitivity (g a.i./ha) Most

Sensitive Endpoint NOER (g a.i./ha) Most

Sensitive Endpoint

Zea mays (corn) 530.7 Biomass 300 Biomass

Lolium perenne (ryegrass) 142.8 Biomass 75 Biomass

Avena sativa (oat) 46.5 Biomass 18.75 Biomass

Linum usitatissimum (flax) 25.35 Biomass 8.34 Height

Allium cepa (onion) 22.5 Biomass 18.75 Height, Biomass

Brassica oleracea (cabbage) 13.55 Biomass 8.34 Height, Biomass

Cucumis sativa (cucumber) 5.69 Biomass 2.78 Biomass

Glycine max (soybean) 3.33 Biomass 2.78 Height, Biomass

Brassica rapa (turnip) 1.45 Biomass 0.93 Biomass

Lycopersicon esculentum (tomato) 1.46 Biomass 0.93 Height, Biomass

Helianthus annuus (sunflower) 0.92 Biomass 0.31 Height, Biomass



### 3.3.3. Incident Reports

Bicyclopyrone has no existing registra tions in North America; theref ore, this assessment assumes that there are no existing incident reports associated with bicyclopyrone use in the United States.



## 4. Risk Characterization

Toxicity data and expos ure estimates for bicyclopyrone are us ed to evaluate the potential for adverse ecological effects on non-target species. This screening-level assessment employs a deterministic risk estimation method, based on RQ va lues, to provide a metric of potential risks ( Section 4.1 ). The potential for risk is further characterized in the Risk Description ( Section 4.2 )

based on the risk estimation results and other relevant information about toxicity and ecosystems potentially at risk, and the environmental fate an d transport characteristic s of bicyclopyrone. In cases where an RQ value exceeds the listed species LO C, the potential for risk to listed species is characterized in greater detail in Section 5

.

4.1. Risk Estimation

Unitless RQ values are compared to the Agency ’s LOCs to identify taxonomic groups potentially

at risk of acute or chronic effects associat ed with the proposed ne w use of bicyclopyrone.

4.1.1. Aquatic Organisms

As shown in

Table 4.1 through Table 4.3 , none of the RQ values calculat ed for the bicyclopyrone TGAI either approach or exceed the Agency’s LOCs for risk to non-listed species of fish and invertebrates or aquatic plants. Chronic RQ values for estuarin e/marine fish and invertebrates are based on chronic toxicity values estimated using an ACR. Based on the 60-day and 21-day-Page 47 of 88- 

### surface water concentrations the values for estuar ine/marine fish and invertebrates, respectively, the NOAEC would need to be less than 0.004 mg/L (4 μg/L) in order for there to be a chronic

risk of concern to estuarine/ma rine fish and invertebrates. EECs are reported for parent only (refer to Section 3.2.2 ).

Table 4.4 through Table 4.6 summarize RQ values for aquati c vascular and nonvascular plants

. Further characterization of the potential for adverse effects to aquatic organisms, based on the available data, is provided as pa rt of the Risk Description in Section 4.2.1 . Two exceedances were observed for listed plants for bicycl opyrone TGAI and formulation A15749AD in Table

4.4 and Table 4.5, respectively (note: data are not av ailable for formulation A14749AD on listed or non-listed nonvascular plants).

Table 4.1. Acute and chronic RQ valu es for freshwater fish and invertebra tes exposed to bicyclopyrone TGAI

in surface water.

Use App

Rate

lbs a.i./A

(#app) App

Method EECs (mg/L) RQ Values

Freshwater Fish

LC 50 =93.4 mg/L (TGAI) NOAEC=10 mg/L Freshwater

Invertebrate

EC 50 =93.3 mg/L (TGAI) NOAEC=103.7 μg/L

Peak 21-d 60-d Acute Chronic Acute Chronic

Corn 0.045 (2) Ground

spray 0.004 0.004 0.004 <0.01 <0.01 <0.01 <0.01

RQ=peak EEC/LC 50 (acute) or 21-day (invert) or 60-day (fish) EEC/NOAEC (chronic).

T he acute risk to listed species LOC (RQ ≥ 0.05); the acute risk to non-listed species LOC (RQ ≥ 0.5); the chronic risk LOC (RQ ≥ 1)

Table 4.2. Acute and chronic RQ valu es for freshwater fish and inverteb rates exposed to bicyclopyrone TEP (A16003E) in su rface water.

Use App

Rate

lbs a.i./A

(#app) App

Method EECs (mg/L) RQ Values

Freshwater Fish

LC 50 =18.6 mg/L (TEP)

NOAEC=NA Freshwater

Invertebrate

EC 50 =19.0 mg/L (TEP)

NOAEC=NA

Peak 21-d 60-d Acute Chronic Acute Chronic

Corn 0.045 (2) Ground

spray 0.004 0.004 0.004 <0.01 NA <0.01 NA

NA Not applicable. RQ=peak EEC/LC 50 (acute) or 21-day (invert) or 60-day (fish) EEC/NOAEC (chronic).

T he acute risk to listed species LOC (RQ ≥ 0.05); the acute risk to non-listed species LOC (RQ ≥ 0.5); the chronic risk LOC (RQ ≥ 1)

Table 4.3. Acute and chronic RQ valu es for estuarine/marine fish and in vertebrates exposed to bicyclopyrone

TGAI in surface water.

Use App

Rate

lbs a.i./A

(#app) App

Method EECs (mg/L) RQ Values

Estuarine/Marine

Fish

LC 50 =123 mg/L (TGAI)

NOAEC=13.7 1 Estuarine/Marine

Invertebrate

EC 50 =3.4 mg/L (TGAI)

NOAEC=3.7 1

Peak 21-d 60-d Acute Chronic Acute Chronic

Corn 0.045 (2) Ground

spray 0.004 0.004 0.004 <0.01 <0.01 <0.01 <0.01-Page 48 of 88- NA Not applicable.

1 Based on ACRRQ=peak EEC/LC 50 (acute) or 21-day (invert) or 60-day (fish) EEC/NOAEC (chronic).

T he acute risk to listed species LOC (RQ ≥ 0.05); the acute risk to non-listed species LOC (RQ ≥ 0.5); the chronic risk LOC (RQ ≥ 1)

Table 4.4. RQ values for listed and non-listed vasc ular and nonvascular aquatic plants exposed to bicyclopyrone TGAI in surface water as a result of spray drift only, based on maximum application rates for

corn.

Use App

Rate

lbs a.i./A

(#app) App

Method EECs (mg/

L) RQ Values

Vascular Plants

EC 50 =0.013 mg/L NOAEC=0.003 mg/L Nonvascular Plants

EC 50 =2.4 mg/L NOAEC=1.0 mg/L

Peak Listed Non-listed Listed Non-listed

Corn 0.45 (2) Ground

spray 0.004 1.3 0.31 <0.01 <0.01

Bold values exceed the plant LOC 1.0 RQ = EEC/EC 50 for non-listed species; EEC/NOAEC for listed species

Table 4.5. RQ values for listed and non-listed vascul ar aquatic plants exposed to bicyclopyrone TEP (A15749AD) in surface water as a result of spray drift only, based on maximum application rates for

corn.

Use App Rate

lbs a.i./A

(#app) App Method EECs (mg/L) RQ Values

Vascular Plants

EC 50 =0.016 mg/L NOAEC=0.004 mg/L

Peak Listed Non-listed

Corn 0.45 (2) Ground spray 0.004 1.0 0.25

Bold values exceed the plant LOC 1.0 RQ = EEC/EC 50 for non-listed species; EEC/NOAEC for listed species

Table 4.6. RQ values for listed and non-listed nonv ascular aquatic plants exposed to bicyclopyrone TEP (A16003E) in surface water as a result of spra y drift only, based on maximum application rates

for corn.

Use App Rate

lbs a.i./A

(#app) App Method EECs (mg/L) RQ Values

Nonvascular Plants

EC 50 =2.0 mg/L NOAEC=0.59 mg/L

Peak Listed Non-listed

Corn 0.45 (2) Ground spray 0.004 <0.01 <0.01

Bold values exceed the plant LOC 1.0 RQ = EEC/EC 50 for non-listed species; EEC/NOAEC for listed species



### 4.1.2. Terrestrial Organisms

In this assessment, acute oral, sub-acute dietary, and chronic RQ values are calculated for birds ( Table 4.7 ) and acute oral and chronic RQ values for mammals ( Table 4.8 and Table 4.9 ).

In the bobwhite quail reproduction study, the most sensitive endpoints were eggs cracked/hen, eggs cracked/eggs laid, hatchlings/egg set, hatchings/live 3-week embryos, and 14-day old survivors/egg set resulting in a NOAEC/LOAEC of 200/640 mg a i/kg diet (19.1/60.1 mg ai/kg-Page 49 of 88- 

### bw). Eggshell thickness was reported as not being significantly different from controls at any

treatment level. In the ma llard duck reproduction study, the most sensitive endpoints were hatchlings/live 3-week embryos, 14-day old surv ivors/hatchling, and 14-d ay old survivors/egg set resulting in a NOAEC/LOAEC of 70/140 mg ai/kg diet (9.1/17.1 mg ai/kg bw).

For the pre-emergent use of bicyclopyrone on corn the acute dose-based RQ values for birds are below the Agency’s LOCs for acute risk to listed (RQ ≥ 0.1) and non-listed (RQ ≥ 0.5) species ( Table 4.7 ). Chronic avian data shown in the ta ble is for the most sensitive species, i.e ., mallard; 70 mg ai/kg diet). Furthermore, as can be seen in Table 6.1 , no exceedances were found using the highest bicyclopyrone concen tration in either of the avia n reproduction studies (Mallard; 35 mg ai/kg diet). Therefore, the reported NOAEL/LOAEL is 200/640 mg a i/kg diet and 70/140 mg ai/kg diet for the Bobwhite qua il (MRID 47842082) and Ma llard (MRID 47842084), respectively.

Table 4.7. Acute a avian, sub-acute dietary, and chronic ,b dietary-based RQ values for TGAI bicyclopyrone. Corn 0.045 lbs a.i./A; 1 application Dietary Category Acute RQs Sub-Acute RQs Chronic RQs

Short Grass 0.01 <0.01 0.15

Tall Grass 0.01 <0.01 0.07 Broadleaf plants 0.01 <0.01 0.08 Fruits/pods/seeds <0.01 <0.01 0.01 Arthropods 0.01 <0.01 0.06

Granivore <0.01 NA NA

NA=Not applicable

a Acute risk LOC exceeded for listed species is 0.1.

b Chronic risk LOC exceeded for liste d and non-listed species is 1.0.



### The acute dose-based RQ values for mammals ar e below the Agency’s LOC for acute risk to listed (RQ ≥ 0.1) and non-listed (RQ ≥ 0.5) species ( Table 4.8 ). However, chronic dose-based RQ values exceed the chronic risk LOC (RQ >1; Table 4.9 ) for small (15 g) and medium (35 g) sized mammals that consume short grass and br oadleaf plants. No chronic risk LOCs are triggered by consumption of tall grass, fruits /pods/seeds, or arthr opods, or by large mammals (1000g) consuming any food source.

Table 4.8. Acute mammalian dose-bas ed RQ values for proposed pre-emergent use of bicyclopyrone on corn. 1,2

Application

Rate lbs a.i./A

#app/interval (d) Body Weight

(g) RQs for Corn

Short Grass Tall Grass Broadleaf Plants Fruits/Pods/Seeds Arthropods

0.045

2/14 Small (15g) <0.01 <0.01 <0.01 <0.01 <0.01

Medium

(35g) <0.01 <0.01 <0.01 <0.01 <0.01

Large (1000g) <0.01 <0.01 <0.01 <0.01 <0.01

1 The acute risk to listed species LOC for mammals is 0.1

2 The acute risk to non-listed sp ecies LOC for mammals is 0.5.-Page 50 of 88- Table 4.9. Chronic mammalian dose-based RQ values fo r proposed pre-emergent use of bicyclopyrone on corn. 1

Application

Rate lbs a.i./A

#app/interval (d) Body Weight

(g) RQs for Corn

Short Grass Tall Grass Broadleaf Plants Fruits/Pods/Seeds Arthropods

0.045

2/14 Small (15g) 2.1 0.9 1.2 0.1 0.8

Medium

(35g) 1.8 0.8 1.0 0.1 0.7 Large (1000g) 0.9 0.4 0.5 0.1 0.4

1 Bolded values exceed the chronic LOC for listed and non-listed mammals (1)



### For terrestrial plants, RQ values ( Table 4.10 and Table 4.11 ) for the pre-emergent use on corn

are calculated based on the most sensitive t oxicity endpoints from the submitted seedling emergence tests. RQ values for listed non-list ed species of monocot pl ants are below the LOC for all areas as a result of runoff and spray drift and for spray drift alone. RQ values for nonlisted dicots in semi-aquatic areas exceed the Agen cy’s LOC for risk to plants. RQ values for listed dicots exceed the Agency’s LOC for plants in dry and semi-aquatic areas due to exposure from runoff and spray drift combined, as well as for exposure from spray drift alone. Tables

4.12 and 4.13 list RQ values for corn based on the use of irrigation water. RQ values for listed and non-listed dicots exceeded the Agency’s LOC for risk to plants using groundwater-derived irrigation water. Conclusions regarding potential ri sk to listed and non-listed terrestrial plants, as they relate to RQ values based on the available NOAEC values, are discussed in Section 4.2

.

Table 4.10. RQ values for non-listed species 1 of non-target terres trial and semi-aquatic plants based on bicyclopyrone on corn (TerrPlant).

Use Dry Area RQs Semi-Aquatic Area RQs Spray Drift Only RQs

Monocot Dicot Monocot Dicot Monocot Dicot

Corn <0.1 0.54 0.31 4.59 <0.1 0.45

Bolded values exceed the Agency’s level of concern (LOC) for risk to listed and non-listed species of terrestrial plants (RQ > 1).

1 Seedling emergence IC 25 and NOAEC monocot values are 0.074 and 0.067, and IC 25 and NOAEC dicot values are 0.005 and 0.002. Vegetative vigor IC 25 and NOAEC monocot values are 0.02 and 0.017, and IC 25 and NOAEC dicot values are 0.001 and

0.0002.

Table 4.11. RQ values for listed species 1 of non-target terres trial and semi-aquatic plants based on bicyclopyrone on corn (TerrPlant).

Use Dry Area RQs Semi-Aquatic Area RQs Spray Drift Only RQs

Monocot Dicot Monocot Dicot Monocot Dicot

Corn <0.1 1.35 0.34 11.48 <0.1 2.25

Bolded values exceed the Agency’s level of concern (LOC) for risk to listed and non-listed species of terrestrial plants (RQ > 1).

1 Seedling emergence IC 25 and NOAEC monocot values are 0.074 and 0.067, and IC 25 and NOAEC dicot values are 0.005 and 0.002. Vegetative vigor IC 25 and NOAEC monocot values are 0.02 and 0.017, and IC 25 and NOAEC dicot values are 0.001 and

0.0002.-Page 51 of 88- Table 4.12. Seedling Emergence RQ val ues for listed and non-listed species 1 of non-target plants based on bicyclopyrone on corn using groundwater-derived irrigation water.

Use Monocot: ryegrass ( Lolium perenne ) Dicot: cabbage ( Brassica oleracea )

IC 25 = 0.074 lbs a.i./A NOAEC = 0.067 lbs a.i./A IC 25 = 0.005 lbs a.i./A NOAEC = 0.002 lbs a.i./A

Corn 0.02 0.03 0.36 0.9

Bolded values exceed the Agency’s level of concern (LOC) for risk to listed and non-listed species of terrestrial plants (RQ > 1).

1 RQ values are based on the irrigation water EEC of 0.0018 lbs a.i./A / the seedling emergence IC 25 (non-listed) or NOAEL (listed) value.

Table 4.13. Vegetative vigor RQ values for listed and non-listed species 1 of non-target plants based on bicyclopyrone on corn using groundwater-derived irrigation water.

Use Monocot: ryegrass ( Lolium perenne ) Dicot: cabbage ( Brassica oleracea )

IC 25 = 0.02 lbs a.i./A NOAEC = 0.017 lbs a.i./A IC 25 = 0.001 lbs a.i./A NOAEC = 0.0002 lbs a.i./A

Corn 0.09 0.11 1.8 9.0

Bolded values exceed the Agency’s level of concern (LOC) for risk to listed and non-listed species of terrestrial plants (RQ > 1).

1 RQ values are based on the irrigation water EEC of 0.0018 lbs a.i./A / the vegetative vigor IC 25 (non-listed) or NOAEL (listed)

value.



### To characterize potential non-targ et plant exposure from spray drift alone, Tier 1 modules in AgDRIFT (v. 2.1.1, December 2011) were used to es timate how far off-site spray drift exposure might occur at a level known to cause adverse eff ects in terrestrial plant toxicity studies. For ground applications, EFED used the American So ciety of Agricultural and Biological Engineers (ASABE, formerly ASAE) Very Fine-to-Fine dropl et size category in it s modeling. This size category is EFED’s default distribution when labe ls do not specify application parameters. The

Dv 50 

### for the Very Fine-to-Fine drople t size distribution is 175 microns.

Table 4.14. Possible Effects Distance for Nontarget Terrestrial Plants Exposed to Bi cyclopyrone through Spray Drift Only Based on the Most Sensitive Crop Species in Submitted Toxicity Studies.

Crop Single Max. App. Rate (lbs a.i./A) AgDRIFT

Scenario Distance from Treatment Site (feet)

Monocots (non-listed)

Onion

IC 25 = 0.02 lbs a.i./A Monocots (listed)

Onion

NOAEL

0.017 lbs a.i./A Dicots (non-listed)

Sunflower

IC 25 = 0.001 lbs a.i./A Dicots (listed)

Sunflower

NOAEL =

0.0002 lbs a.i./A

Corn 1 0.045 Ground spray 6.6 6.6 111.6 456

1 While the max application rate during the gr owing season is 0.045 lbs a.i./A, it can be applied as a split dose during the grow ing

season.



### Although the Agency does not typica lly quantify risk to non-target terr estrial invertebrates using the RQ method, acute toxicity studies with the young adult honey bee demonstrate that bicyclopyrone is practically non- toxic to young adult honey bees on an acute oral and an acute contact exposure basis (LD 50 

### >11 μg a.i./bee). The potential fo r risk to non-target terrestrial organisms, associated with the proposed pr e-emergent and early post-emergent use of bicyclopyrone on corn, is discussed further in the Risk Description ( Section 4.2.2 ). There is uncertainty regarding the pot ential acute and chronic eff ects of the compound on honey bee larvae as well as potential for chronic effects of adult. Since bicycl opyrone is a systemic herbicide, residues may be present in pollen and/ or nectar and represent a route of exposure for-Page 52 of 88- 

### bees through both contact and ingestion. Therefor e, there is uncertainty with respect to the

likelihood of adverse effects from acute or chronic exposure of larv al bees to residues that may be translocated to pollen/nectar.

4.2. Risk Description and Conclusions

This assessment evaluates the potential for ecological risks associated with the proposed use of the new herbicide bicyclopyrone as a pre-emergent or early post- emergent ground spray on corn. Bicyclopyrone is a selective, sy stemic herbicide of the HPPD-inhibitor cla ss. The compound is stable to hydrolysis, but de grades on soil by photolysis (non-persistent) and aerobic biodegradation (slightly persistent to persiste nt). With a pKa of 3.06, bicyclopyrone will exist predominantly as an anion at environmentally rele vant pH values, and is expected to be very highly mobile in soil and lik ely to move into surface a nd groundwater. Bicyclopyrone photodegrades slowly in water, but biodegrades in aquatic systems at a negligible rate.

4.2.1. Aquatic Organisms

RQ values are calculated for estimating acute and chronic risk to fish a nd aquatic invertebrates, where the submitted ecotoxicity data are sufficient to use in risk estimation. Aquatic animal and plant toxicity data reported in Section 3.3.1.1 and EECs are both reported in similar units, i.e., mg/L. For the proposed use of bicyclopyrone, acut e and chronic RQ values are below the listed (RQ ≥ 0.05) and non-listed (RQ ≥ 0.1) species acute and chronic (RQ ≥ 1.0) risk LOCs for all assessed fish and aquatic invert ebrates based on toxicity of th e TGAI. RQ values for the formulated product TEP A16003E, tested only in acute studies on freshwater fish and invertebrates, were below LOCs. However, us ing TGAI, chronic NOAEC values would need to

be ≤ 0.004 mg a.i./L to listed and non-listed estu arine/marine fish and invertebrates for

exceedances to occur.

While TGAI bicyclopyrone had no LOC exceedances (RQ ≥ 1) for nonvascular plants and nonlisted vascular plants, it did have an exceedan ce for listed vascular plants. Likewise, TEP

formulation A15749AD had an LOC exceedance for listed vascular plants, but not for non-listed vascular plants. The formulation A16003E had no exceedances for listed or non-listed nonvascular plants. Based on submitted data, vascular plants are more sensitive to bicyclopyrone than are nonvascular plants (EC 50 

### =0.0013 mg/L for duckweed compared to an

EC 50 

### =2.0 mg/L for green algae). Between nonvascular species (green algae, blue-green algae, freshwater diatom, and marine diatom), toxicity values i.e., EC 50 

### values, were roughly similar (range 2.0-9.8 mg/L) except for blue -green algae which had an EC 50 

### >94.8 mg/L.

4.2.2. Terrestrial Organisms

Acute and sub-acute RQ values calculated fo r dose-based risk to birds (and reptiles and terrestrial-phase amphibians for which birds se rve as surrogates) indicate no LOC exceedances although there is uncertainty regard ing passerine species. If the passerine data were to be used,

there would be an exceedance to li sted species (LOC >0.1) for small birds feeding on short grass. No chronic risk LOC is exceeded based on the avian toxicity data although there is some uncertainty with the bobwhite quail and mallard duck reproduction studies. For the bobwhite-Page 53 of 88- 

### quail study, a dose-response was not observed for mean hatching weight even though a statistically significant effect was indicated for the endpoint . Likewise, in the mallard study, a dose-response was not observed for eggs laid/hen and mean 14-day old survivors weight even though a statistically significant effect was obser ved. Also, there was a slight dose-response effect in mean hatchling weight of mallards; however, the highest bicyclopyrone concentration showed the lowest difference compared to contro ls while the lowest bi cyclopyrone concentration had the greatest difference. In both avian reprod uction studies there appeared to be considerable variability in control birds making it di fficult to detect treatment effects.

Acute laboratory tests with terrestrial insects ( i.e. , honey bee) have demonstrated that bicyclopyrone is practically non- toxic to adult honey bees on an acute oral and contact exposure basis, although there is uncertain ty regarding the potenti al chronic effects on adult bees and acute

and chronic effects on larvae.

The RQ values in Section 4.1 demonstrate that pre-emergent use of bicyclopyrone on corn may result in chronic risk to mammals (RQ>1.0). A lthough bicyclopyrone is cla ssified as practically non-toxic to mammals on an acute oral exposure ba sis, chronic RQ values indicate the potential for adverse effects. The submitted two-generation reproduction study in rats indicated toxicity at 25 mg/kg bw/day resulting in decreased ab solute body weights and body weight gains (an increased vascular keratitis in F1 and F2 genera tions was also observed). The chronic risk LOC was triggered for small and medium-sized mamma ls that consume short grass and broadleaf plants. No LOC exceedances were observed w ith large mammals. No LOC exceedances for acute dose-based exposure to mammals of any size category. In order to get below the chronic risk LOC for small and medium-sized mammals, the application rate would need to decrease from 0.045 to 0.021 lbs a.i./A (roughly half).

RQ values for listed and non-listed species of monocot plants are below the LOC for dry and semi-aquatic areas exposed through runoff and sp ray drift combined as well as through spray drift alone. RQ values for non-lis ted dicots in semi-aquatic areas exceed the LOC for risk to terrestrial plants. RQ values for listed dicots exceed the LOC for dry and semi-aquatic areas exposed through runoff and spray drift combined, as well as through spray drift alone. RQ

values for listed and non-listed dicots exceed the Agency’s LOC for risk to plants using irrigation water based on data fr om vegetative vigor studies alone . Irrigation wa ter LOC’s were

not exceeded for monocots and dicots based on the seedling emergence data, or for monocots based on vegetative vigor study data. Based on submitted data, the most sensitive monocot in seedling emergence and vegetative vigor, i.e ., ryegrass and onion, respectively, were roughly an order of magnitude less sensitive than the most se nsitive dicot species, ca bbage and sunflower.

4.2.3. Conclusions

Based on this screening-level assessment, th e physicochemical properties of bicyclopyrone indicate that the herbicide has the potential to reach aquatic environments, including surface and ground water following pre-emergent applications. The available ecotoxicity data demonstrate that bicyclopyrone is practically-to-moderately nontoxic to fish and a quatic invertebrates and LOCs were not exceeded. Using TGAI bi cyclopyrone or A16003E, chronic NOAEC values

would need to be ≤ 0.004 mg a.i./L to lis ted and non-listed estuarine/ma rine fish and invertebrates-Page 54 of 88- 

### for exceedances to occur. Therefore, the likelihood of adverse effects to fish, aquatic invertebrates, and aquatic-phase amphibians, fr om exposure to bicyclopyrone from the proposed

uses is considered low. Estuarine/marine invertebrates are more sensitive than freshwater invertebrates on an acute exposure basis. Howeve r, based on chronic toxicity values estimated using ACRs, RQ values are be low the chronic risk LOC for estuarine/marine fish and

invertebrates.

The risk hypothesis and conceptual diagrams articula ted in the initial proble m formulation of this assessment identified concerns that the proposed use of bicyclopyrone may result in adverse effects on survival and growth in aquatic plants, and chronic risk to sma ll (15 g) and medium (35 g) size classes of mammals. Data indicate monoco ts are less susceptible to the toxic effects of bicyclopyrone than are dicots. RQ values for non-listed dicots in semi-aquatic areas exceed the Agency’s LOC for risk to plants. RQ values for listed dicots exceed the Agency’s LOC for plants in dry and semi-aquatic areas due to expo sure from runoff and spray drift combined, as well as for exposure from spray drift alone. Submitted bicyclopyrone data could not be used to determine chronic risk to avian taxa (and terrestrial-phase amphibians and reptiles) as reproductive effects were observed at all test concentrations us ed in the studies thereby not establishing a NOAEL. Additiona lly, the acute study with the pa sserine species resulted in regurgitation and/or mortality. Th erefore, risk to these taxa cannot be precluded. Although the

acute oral and contact terrestrial invertebrate st udies indicate bicyclopyr one is practically nontoxic to the honey bee, there is uncertainty rega rding the potential acute and chronic effects of the compound on honey bee larval development and su rvival as well as potential for chronic

effects of adult bees.



## 5. Federally Threatened and Endang ered (Listed) Species of Concern

Consistent with the Agency’s responsibility under the Endangered Sp ecies Act (ESA), the Agency evaluates risks to listed species from regi stered use of bicyclopyrone. This assessment is

conducted in accordance with the Overview Document (USEPA, 2004), provisions of the Endangered Species Act (ESA), and the Services’ Endangered Species Consultation Handbook (USFWS/NMFS, 1998).

5.1. Action Area

For listed species assessment purposes, the action area is considered to be the area affected directly or indirectly by bicyclopyrone use and not mere ly the immediate area where bicyclopyrone is applied. At the initial screening-level, th e risk assessment considers broadlydescribed taxonomic groups and cons ervatively assumes that listed species within those broad groups are co-located with the pesticide trea tment area. This means th at terrestrial plants and

wildlife are assumed to be locate d on or adjacent to the treated site, and aquatic organisms are assumed to be located in a surface water body adj acent to the treated site . The assessment also assumes that listed species are located within an assumed area which has the highest relative potential exposure to the pesticide, and that expo sures are likely to decrease with distance from

the treatment area. Section 6.2 of this risk assessment presents the proposed pesticide use sites

that are used to establish initial co-l ocation of species with treatment areas.-Page 55 of 88- 

### 5.2. Taxonomic Groups Potentially at Risk

If the assumptions associated with the screenin g-level action area result in RQs that are below the listed species LOCs, a "no effect" determination conclusion is made with respect to listed species in that taxa, and no further refinement of the action area is necessary. Furthermore, RQs below the listed species LOCs for a given tax onomic group indicate no concern for indirect effects on listed species that depend upon the taxonomic group for which the RQ was calculated. However, in situations where the screening assu mptions lead to RQs in excess of the listed species LOCs for a given taxonomic group, a potenti al for a "may affect" conclusion exists and may be associated with direct effects on listed species belonging to that taxonomic group or may extend to indirect effects upon listed specie s that depend upon that taxonomic group as a resource. In such cases, additional information on the biology of listed species, the locations of these species, and the locations of use sites could be considered to determine the extent to which screening assumptions regarding an action area a pply to a particular listed organism. These subsequent refinement steps could consider how this information would impact the action area for a particular listed organism and may potentially include areas of expo sure that are downwind and downstream of the pesticide use site.

Assessment endpoints, exposure pathways, the c onceptual diagram addressing the proposed new bicyclopyrone use, and the a ssociated exposure and effect s analyses conducted for the bicyclopyrone screening-leve l risk assessment are in Sections 2 to 3 . The assessment endpoints used in the screening-level risk assessment include those defined ope rationally as reduced survival and reproductive impairment for both aqua tic and terrestrial animal species and survival, reproduction, and growth of non-target aquatic a nd terrestrial plant species from exposure via spray drift and runoff. These assessment endpoi nts address the standa rd set forth in the Endangered Species Act requiring federal agencies to ensure that any action it authorizes does not appreciably reduce the likelihoo d of both the survival and recove ry of a listed species in the wild by reducing the reproduction, nu mbers, or distribution of the species. Risk estimates (RQ values) integrating exposure a nd effects are calculated for broa d-based taxonomic groups in the screening-level risk assessm ent and are presented in Section 4.

Both acute and chronic risk to listed species LO Cs are considered in the screening-level risk assessment to identify direct and indi rect effects to taxa of listed species. This section identifies

direct and indirect effect conc erns, by taxa, that are triggered by exceeding listed species LOCs in the screening-level risk assessment. Althoug h concern levels were not exceeded for risk to fish, aquatic-phase amphibians, mollusks, inverteb rates, birds, terrestrial-phase amphibians, and reptiles, indirect effects to these taxa are pos sible given the potential for adverse effects to terrestrial and semi-aquatic plants (via spray dr ift which cannot be precluded) and mammals. Potential effects include, but are not limited to, reduction in food resources , decrease in cover, change in water quality parameters, and loss of breeding/nesting habitat. Additional Description of Assumptions, Limitations, Uncertain ties, Strengths and Data Gaps-Page 56 of 88- 

### Aquatic Exposure

This assessment is based upon available environmen tal fate data. There are no significant data gaps in the environmental fate database submitte d by the registrant. However, there is some uncertainty introduced by a supplemental subm itted non-guideline aerobic aquatic metabolism study that was irradiated during the incuba tion (MRID 47842075; water pH 7.5-7.9, sediment pH 7.1-7.3). In the study, bicyclopyrone dissipated with half-lives of 7.4 and 7.5 days, despite the fact that the compound photodegrades only slowly in water, with respective half-lives of 11 and 50 days at pH 5 and 7, and 74.8 days in natural water (pH 7.3), and was relatively stable in the submitted guideline aerobic aquatic studies (which are conducted in darkness). However, the significance of this ( i.e ., rapid dissipation when the study in cludes irradiation compared with relative stability when it is conducted in darkness ) is unclear, and there were multiple issues with the study that resulted in a classificati on of “reliable with restrictions.”

Additionally, the registrant has sought to show that parent co mpound transported below the soil surface may be wicked upward through evaporative transport flux in the soil and subsequently photodegraded on the surface soil, resulting in more rapid degradation than would occur in soil through metabolism alone (MRIDs 47842030, 47842170). The registrant has hypothesized that the rapid dissipation and lack of substantial leachi ng in the terrestrial field studies is attributable to this process. However, the correlation betw een half-lives and total irradiance is poor (with and without accounting for water input during the fi rst week), and it is noted that the maximum concentration for the soil photolysis transf ormation product SYN503780 was observed at 1 day post-treatment in two of the three U.S. terrestrial field studies, and was not detected below the 0- to 15-cm depth in those. However, in pr ospective groundwater st udies following parent bicyclopyrone application, SYN503 780 was detected in wells at sampling intervals up to 3 years after application.

SWCC simulates the impact of daily weather on the treated agricultural field, and resulting concentrations in an adjacent farm pond over a de fined period (here, thirty years). During this time, pesticide is washed-off of the field into the water-body by twenty to forty rainfall/runoff events per year. Each new additi on of pesticide mass adds to the existing pesticide mass left over in the pond from previous runoff and/or spray-drif t events. Since bicyclopyrone is persistent in aquatic environments, it accumulates in the pond fr om one year to the ne xt. One consequence is that the yearly simulated peaks are not indepe ndent of year other but are temporally autocorrelated, meaning that the “1-in-10 year EECs” obtained from model post-processing are in part functions of the simulation duration, and are therefore inaccurate. As a result, SWCC results likely overestimate concentrations in streams and various other kinds of water bodies, as over the course of thirty years, some loss of bicyclopyro ne is expected due to washout, dispersion, burial of sediment and other dissipative processes that aren’t simulate d. In particular, bicyclopyrone concentrations in lotic (flowing) water bodies are not expected to accumulate from year to year

because of downstream advective removal.

The labels specify that bicyclopy rone is generally to be applied once annua lly; however, a split application for pre-emergent and early post- emergent is allowed, provided the maximum recommended application/year of 0.04 lb a.i./A (50g/ ha). Aquatic exposure in this assessment is-Page 57 of 88- 

### based on the single pre-emergent application. If a split application is used, the acute aquatic exposure in the environment may be less than that estimated quantitativel y in this assessment.

For ecological effects, no data have been submitte d for chronic effects to estuarine/marine fish and invertebrates. However, ACRs were used to estimate chronic toxicity values for both the

estuarine/marine fish and invertebrates

Terrestrial Exposure

Bicyclopyrone is generally applied once annually; however, a split application for pre-emergent and early post-emergent is allowed, provided the maximum recommended application/year of 0.04 lb a.i./A (50g/ha). Terrestrial exposure in this assessment is based on a single application. Also, if applied as a pre-emergent, bicyclopyrone will be applied to the soil surface rather than on growing plants. Thus, actual terrestrial exposu re in the environment may be less than that estimated quantitatively in this assessment.

There is uncertainty with the avian reproduction st udies due to the lack of dose-response in both studies. Specifically, for the bobwhite quail study, a dose-response was not observed for mean hatching weight even though a statistically significan t effect was detected. In the mallard study, a dose-response was not observed for eggs laid/h en and mean 14-day old survivors weight even though a statistically significant effect was obser ved across multiple dietary treatment levels. Although mean hatchling weight appeared to be somewhat treatment-related, the highest bicyclopyrone dietary concentration showed the lowest difference compared to controls while the lowest bicyclopyrone dietary concentratio n had the greatest difference. In both avian reproduction studies there appeared to be consid erable variability in control birds making it

difficult to detect treatment effects. Howeve r, using the most cons ervative bicyclopyrone toxicity value ( i.e ., mallard NOAEL of 35 mg ai/kg diet) in risk estimation, no chronic risk LOC

is exceeded. In order for chro nic exceedances to occur, the toxi city value for the Mallard study would have to be 10 mg ai/kg diet based on an application rate on corn of 0.045 lbs ai/A with 1 application.

Table 5.1. Potential effects to federally listed avia n taxa associated with the proposed used of TGAI bicyclopyrone.

Mallard duck ( Anas platyrhynchos )

MRID 47842084 Corn 0.045 lbs a.i./A; 1 application

Dietary Category Chronic RQs

Short Grass 0.29

Tall Grass 0.13 Broadleaf plants 0.16 Fruits/pods/seeds 0.02 Arthropods 0.11

Granivore NA

NA=Not applicable

1 Chronic risk LOC exceeded for liste d and non-listed species is 1.0.-Page 58 of 88- 

### The submitted acute oral toxicity study to a pa sserine species (MRID 47842078) is classified as supplemental because exposed canaries exhibite d regurgitation and mortality was observed at multiple test concentrations.

Although data from the acute contact and oral t oxicity tests with young adult honey bees indicate bicyclopyrone is practica lly non-toxic to bees on an acute exposure basis, ther e is uncertainty regarding the potential acute and chronic ef fects of the compound on honey bee larval development and survival as well as potentia l for chronic effects of adult bees. Since bicyclopyrone is a systemic herbicide, residues may be transported to pollen and/or nectar and represent a route of exposure for bees through both contact and ingestion. Therefore, additional data on pollinators are needed to fully characterize the potential risk associated with bicyclopyrone use to all developmental stages of honey bees, as sensitivity may vary according to life-stage and length of exposure (adult vs. la rval and acute vs. chronic, respectively).

Data Gaps

There are no fate data gaps for bicyclopyrone.

Appendix F lists whether data gaps for ecological effects have been identified.

No data have been submitted for chronic toxicity to estuarine/marine fish and invertebrates. Therefore, estuarine/marine i nvertebrate life-cycl e (OCSPP 850.1350) and estuarine/marine fish early-life stage (OCSPP 850.1400) are cl assified as data gaps. However, in the absence of these data, ACRs have been used to estimate ch ronic toxicity endpoints for these taxa.

The submitted acute oral toxicity study to a pa sserine species (MRID 47842078) is classified as supplemental because regurgitation and mortality co incided at multiple test concentrations to exposed canaries. Furthermore, the study resulted in a more sensitive endpoint than the other

acute avian studies submitted and thus would be im portant in the characterization to avian taxa. Therefore this study is listed as a data gap.



## 6. References

Fletcher, J.S., J.E. Nellessen, and T.G. Pfleeger. 1994. Literature review and evaluation of the EPA food-chain (Kenaga) nomogram, and instrument for estimating pesticide residues on plants. Environmental Toxicology and Chemistry 13 (9):1383-1391.

Hoerger, F., and E.E. Kenaga. 1972. Pesticide residue s 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. 2014a. Data on Bicyclopyrone and Its Environmental Transformation Products in Support of the ROCKS. September 2014 Memo from Ideliz Negrón-Encarna ción, ROCKS Alternate Secretary Health Effects Division, to Bicyclopyrone Risk Assessment Team Risk Assessment Branch I, HED. DP Barcode

D421264.-Page 59 of 88- USEPA. 2014b. Bicyclopyrone. Report of the Residues of Concern Knowledgebase Subcommittee (ROCKS). July 24, 2014 Memo from Cheryl Sutton and Andrew Sayer, EFED, to ROCKS Co-Chairs Christine Olinger, HED, and Edward Scollon, EFED. DP Barcode D421260.

USEPA. 2012. White Paper in Support of the Proposed Risk Assessment Process for Bees. September 11-14, 2012

. September 11, 2012. U.S. Environmental Protection Agency. Pest Management Regulatory Agency. California Department of Pesticide Regulation. Available at http://www.regulations.gov/#!documen tDetail;D=EPA-HQ-OPP-2012-0543-0004 (Accessed August 18, 2014).

USEPA. 2004. Overview of the Ecological Risk Assessmen t Process in the Office of Pesticide Programs, U.S. Environmental Protection Agency. Endangered and Threat ened Species Effects Dete rminations. Office of Prevention, Pesticides and Toxic Substances, Office of Pesticide Programs, Washington, D.C. Available

online at http://www.epa.gov/oppfead1/endanger/ consultation/ecorisk-overview.pdf

USEPA. 1998. Guidelines for Ecological Risk Assessment. EPA/630/R-95/002F. Published in 63 FR 26846; May 14, 1998. U.S. Environmental Protection Agency, Washington, DC. April, 1998. Available at http://www.epa.gov/raf/publications/pdfs/ECOTXTBX.PDF

USFWS/NMFS. 1998. Endangered Species Consultation Handbook: Procedures for Conducting Consultation and Conference Activities Under Section 7 of the Endangered Sp ecies Act. Final Draft. United States Fish and Wildlife Service (USFWS) and National Marine Fisheries Service (NMFS). Available at http://sero.nmfs.noaa.gov/pr/esa/pdf/Sec%207%20Handbook.pdf (Accessed November 7, 2012).

Fate MRIDs

MRID 47841919. Adam, D., 2008. [Pyridinyl-14C]-labelled NOA449280 – Hydrolysis at four different pH values. Syngenta Ltd., Jealott’s Hill International Research Ce ntre, Bracknell, Berkshire, RG42 6EY, UK. RCC Study Number: B75598. Syngenta Sypos task ID: T013175-05.

MRID 47842075. Adam, D., 2010. NOA449280 – Route and rate of degradation in water/sediment system under artificial sunlight. Syngenta Ltd., Jealott’s Hill Internatio nal Research Centre, Bracknell, Berkshire, RG42 6EY, UK. Study Number: 115 01 042. Task Number: T002567-08.

MRID 47842055. Brice, A.; Gilbert, J. 2010. NOA4492 80- Adsorption and Desorption Properties in Seven Soils: Final Report. Project Number: 1'001923/07/0C~ 1983/076/D2149, 1983/076. Unpublished study prepared by Covance Laboratories, Ltd. 144 p.

MRID 47842027. Brice A and J. Gilbert, 2010. NOA449280 - Metabolism and rate of degradation of 14C-pyridinyl and 14C-bicyclooctenone labelled NOA449280 under anaerobi c laboratory conditions, in one Soil, at 20°. Syngenta Ltd., Jealott’s Hill International Research Centre, Brackne ll, Berkshire, RG42 6EY, UK. Report Number: 1983/070-

D2149. Task Number: T013196-05.

MRID 47842066. Finger, N., 2012a. NOA449280 - Leachi ng behaviour of NOA449280 and its metabolite into groundwater in a field trial – Lorsch, Germany, 2007-201 2. Syngenta Ltd., Jealott’s Hill International Research Centre, Bracknell, Berkshire, RG42 6EY, UK. Report Number: S07-00066-Interim-1. Task Number: TK0009218.

MRID 47842067. Finger, N., 2012b. NOA449280 - Le aching behaviour of NOA449280 and its metabolite into groundwater in a field trial – Aba, Hungary. Syngenta Ltd. , Jealott’s Hill International Research Centre, Bracknell, Berkshire, RG42 6EY, UK. Report Number: S08-01322-Interim-1. Task Number: TK0009273.

MRID 47842068. Finger, N., 2012c. NOA449280 - Leaching behaviour of NOA449280 and its metabolite into groundwater in a field trial – Alsace, Fr ance. Syngenta Ltd., Jealo tt’s Hill International Res earch Centre, Bracknell, Berkshire, RG42 6EY, UK. Report Number: S08-01327-INTERIM-1. Task Number: TK0009274.-Page 60 of 88- MRID 47842073. Gassen M, 2009, NOA449280 - [Pyridinyl-3-14C]-labelled NOA449280 - Metabolism and rate of degradation under aerobic and anaerobic conditions in aqua tic systems. Syngenta Ltd., Jealott’s Hill International Research Centre, Bracknell, Berkshire, RG42 6EY, UK . Study Number: B44425. Syngenta Reference Number:

T013193-05.

MRID 47842074. Gassen M, 2010. [Bicyclooctenone-6,7-14C2]-labelled NOA449280 – Metabolism and rate of degradation under aerobic and anaerobic conditions in aqua tic systems. Syngenta Ltd., Jealott’s Hill International Research Centre, Bracknell, Berkshire, RG42 6EY, UK . Study Number: B46012. Syngenta Reference Number:

T013194-05.

MRID 47842030. Hand, L., C. Nichols and S. Kuet, 2012. Investigation into the factors controlling photolysis and the movement of the active ingredient within soil. Syng enta Ltd., Jealott’s Hill International Research Centre, Bracknell, Berkshire, RG42 6EY, UK. Report Number: PM-08-533. Task Number: T000808-07.

MRID 47842026. Lewis C., 2009. NOA449280 – Metabolism and Rate of Degradation of 14 C-Bicyclooctenone Labelled NOA449280 under Aerobic Laboratory Conditions, in One Soil, at 20°C, Covance Laboratories Limited, UK. Report Number: 1983/071-D2149. Unpublished report (Syngenta File No. NOA449280_11046).

MRID 47842026. Lewis, C.; Gilbert, J. 2012. NOA449 280- Metabolism and Rate of Degradation of [Carbon 14]Bicyclooctenone Labelled NOA449280 Under Aerobic Laboratory Conditions, in One Soil, at 20 (Degrees Celsius): Final Report. Project Numb er: T013183/05/0CR, 1983/071/D2149, 1983/071. Unpublished study prepared by Covance Laboratories, Ltd. 83 p.

MRID 47842032. Brice, A.; Heslop, D. 2009. NOA449280 - Rate of Degradation ofNOA449280 Under Aerobic Laboratory Conditions, in Five Soils, at 20 (D egrees Celsius): Final Report. Project Number: T001436/08/0CR, 1983/089/D2149. Unpublished study prepared by: Covance Laboratories, Ltd .. 117p.

MRID 47842033. Lewis, C.; Gilbert, J. 2009. NOA44928 0 - Metabolism and Rate of Degradation of [Carbon 14]Pyridine Labelled NOA449280 Under Aerobic Laboratory Conditions, in Seven US Soils, at 20 (Degrees Celsius): Final Report. Project Numb er: T001922/07/0CR, 1983/075/D2149. Unpublished study prepared by Covance Laboratories, Ltd. 222 p.

MRID 47842034. Lewis, C.; Gilbert, J. 2009. NOA4 49280- Metabolism and Rate of Degradation of [Carbon 14]Pymine Labelled NOA449280 Under Aerobic Laboratory Conditions, in Five Soils, at 20 (Degrees Celsius): Final Report. Project Number: T013182/05/0CR, 1983/069/D2149. Unpublished study prepared by: Covance Laboratories, Ltd . 188 p.

MRID 47842036. Lewis, C.; Gilbert, J. 2010. NOA449280- Ra te of Degradation of [Carbon 14]-Pyridine Labelled SYN503780, a Soil Metabolite, Under Aer obic Laboratory Conditions, in Thr ee Soils, at 20 (Degrees Celsius). Project Number: T005859/06/0CR, 1983/085/D2149. Unpublished study prepared by: Covance Laboratories, Ltd. 170 p.

MRID 47842037. Dixon, K.; Gilbert, J. 2010. NOA449280- Rate of Degradation of [Carbon 14]-Pyridine Labeled CSAA806573, a Soil Metabolite, Under Aerobic Laboratory Conditions, in Three Soils, at 20 (Degrees Celsius): Final Report. Project Number: T007596/08/0CR, 1983/113/D2149. Unpublished study prepared by Covance Laboratories, Ltd. 117 p.

MRID 47841921. Lewis C. J. And J. Gilbert, 2009. [14C]NOA449280 - Photodegradation and quantum yield in sterile, aqueous solution. Syngenta Ltd., Jealott’s Hill In ternational Research Centre, Bracknell, Berkshire, RG42 6EY, UK. Report Number: 8215834-D2149, Task Number: TK011883.

MRID 47842028. Lewis, C.J. and J. Gilbert, 2010. [14C]NOA449280 - P hotodegradation on Soil Surface. Final Report Amendment 1.Syngenta Ltd., Jealott’s Hill Internat ional Research Centre, Bracknell, Berkshire, RG42 6EY, UK. Report Number: 1983/072-D2149, Task Number: T013191-05.-Page 61 of 88- MRID 47842029. Lewis, C.J. and J. Gilbert, 2011. [14C]NOA449280 -Photodegradation on three US soils. Syngenta Ltd., Jealott’s Hill International Research Centre , Bracknell, Berkshire, RG42 6EY, UK. Report Number: 8215834-D2149, Task Number: TK011883.

MRID 47842060 Lewis, C.; Gilbert, J. 2009. NOA449280- Adsorption and Desorption Properties of [Carbon14]SYN503780 in Four Soils: Final Report. Project Number: 1'005863/06/0CR, 1983/086/D2149. Unpublished study prepared by Covance Laboratories, Ltd. 72 p.

MRID 47842057 Lowden, P.; Brett, R. 2009. [Carbon 14]-NOA449280- Adsorption and Desorption Properties of Two Soils: Final Report. Project Number: 1'013198/05/0CR, NC/07/003. Unpublished study prepared by Battelle UK Ltd. 85 p.

MRID 47841909. Geoffroy, A., 2007. NOA449280 – Vapour Pressure. Syngenta Crop Protection Münchwilen AG, CH-4333 Müchhwilen, Switzerland. Study Number: L07-002662.

MRID 47841914. Weissenfeld, M., 2009. NOA449280 Determination of the water solubility. Syngenta Crop Protection Münchwilen AG, Breitenloh 5, 4333 Münchwilen, Switzerland. Harlan Laboratories Study B46056.

MRID 47842060. Peranginangin, N., D.P. Simmons, A. Sapiets, C. Nichols, 2012. Refined modelling of NOA449280 using data from targeted higher tier laboratory studies to reflect a conceptual model of dissipation pathways under field conditions. Syngenta Crop Protecti on, LLC., Greensboro, NC. Report Number: TK0009393.

MRID 47842038. Simmons, D. and A. Newcombe, 2011a. Dissipation of NOA449280 EC Formulation in Bare Soil Plots Under Simulated Field Corn Production Conditions. Syngenta Crop Protection , LLC., Greensboro, NC. Report Number: T004878-06.

MRID 47842039. Simmons, D., B. Jacobson, N. McLean and A. Sapiets, 2011a. Dissipation of NOA449280 EC formulation on bare soil under simulated corn production conditions in Iowa. Syngenta Crop Protection, LLC., Greensboro, NC. Report Number: T004878-06.

MRID 47842040. Simmons, D., B. Jacobson, N. McLean and A. Sapiets, 2011b. Dissipation of NOA449280 EC formulation on bare soil under simulated corn production co nditions in Nebraska. Syngenta Crop Protection, LLC., Greensboro, NC. Report Number: T004880-06.

MRID 47842070 S:immns, D.; McLean, N. 2012. NOA449280- Stability of NOA449280 and SYN503780 in Soil Under Freezer Storage Conditions: Final Re port. Project Number: T002698/07/ORC

, 11SYN2791REP. Unpublished study prepared by Syngenta Crop Protection LLC and ALS Environmental 141 p.

MRID 47842162. Simmons, D.; McLean, N. 2012. StabilityofCSCC163768, CSCD656832, CSCD642512 and

CSAA806573 in Soil U nder Freezer Storage Conditions: Final Re port. Project Number: T013395/05/0C~ 12SYN3161REP. Unpublished study prepared by Syngenta Crop Protection, LLC and ALS Environmental 267 p.

MRID 47842069. Trev isan, M., 2012. NOA449280 – Fiel d leaching behaviour study at site L01 (Orzinuovi-BS) in Italy – multisite study. Syngenta Ltd., Jealott’s Hill Interna tional Research Centre, Brackne ll, Berkshire, RG42 6EY, UK. Report Number: CZ/08/019/UCSC/NOAGL1/R1. Task Number: TK002356-07 (TK0009355).

MRID 47842071. Zietz, E ., 2012. NOA449280 - Leaching behavi our of NOA449280 a nd its metabolite SYN503780 into groundwater in a field trial – Buzet-sur-Tar n, France. Syngenta Ltd., J ealott’s Hill International Research Centre, Bracknell, Berkshire, RG42 6EY, UK. Report Number: IF-08/01121619-INT-1. Task Number:

TK002355-07.

MRID 47842123. Zietz, E. 20 12. NOA449280 - Determination of the St orage Stability ofNOA449280 and its Metabolites SYN503780, CSCC163768, CSCD656832, CSCD642512 and CSAA806573 in Groundwater: Final Report. Project Number: TK0009215/0CR, IF/09/01378891. Unpublished-Page 62 of 88- study prepared by SGS Institut Fresenius GmbH. 97 p.

MRID 47842117. Brain, R. 2011. NOA449280- Waiver Justification for Fish Bioaccumulation Study. Project Number: TK0089334/0CR Unpublished study prepared by Syngenta Crop Protection, LLC. 5 p

MRID 47841950. Braid, S.; McLean, N. (2009) NOA449280- Residue Analytical Method fur the Determination of NOA449280 and its Metabolites SYN503780, CSCD6 56832, CSCD642512, CSCC163768 and CSAA806573 in Soil Final Determination by LC-MS/MS. Project Number: 1'000993/08/0CR, GRM030/04A. Unpublished study prepared by Syngenta Jealotts Hill In ternational Research Centre. 144p.

MRID 47841954 Crook, S. (2008) NOA449280- Residue Method for the DeterminationofNOA449280 and Metabolite SYN503780 in Water: Final Determination byLC-MS/MS. Project Number: T010139/040CR, GRM030/01A. Unpublished study prepared by Syngenta Jealotts Hill International Research Centre. 48 p.

MRID 47841955 Morriss, A; Eversfield, S. (2008) NOA449280- Validation of a Method (Draft GRM030.01A) for the DeterminationofNOA449280 and SYN503780 in Drinking, Surface and Ground Water. Project Number: 1'013212/05/0CR, CEMR/3547. Unpublished study prepared by CEM Analytical Services, Ltd. 35 p.

MRID 47841956 Zietz, E. (2011) NOA449280- Validation of an Analytical Method (Draft GRM030.06A) for the

DeterminationofNOA449280 and its Metabo lites SYN503780, CSCC 163768, CSCD 656832, CSCD642512 and CSAA806573 in Water. Project Number: TK0009384/0CR, lF/09/01378742. Unpublished study prepared by SGS Institut Fresenius Chemisch e und Biologische. 123 p.

MRID 47841959. Oppilliart, S. (20 08) NOA449280-Validation of Residue Method AGRIMOA/NOA449280-2 for the DeterminationofNOA449280 in Air: Final Report. Project Number: 1'013551/05/0CR, 1'013551/05/REG. Unpublished study prepared by ADME Bioanalyses. 41 p.

MRID 47841949. Hargreaves, S. (2007) NOA449280 - Residue Method fur the Determination ofNOA449280 and

Metabolite SYN503780 in Soil: An alytical Method. Project Numb er: T013208/05/0 CR,GRM/030/02A. Unpublished study prepared by Syngenta Jea1otts Hill International Research Centre. 47 p.

MRID 47841950. Braid, S.; McLean, N. (2009) NOA449280 - Residue Analytical Method fur the Determination of NOA449280 and its Metabolites SYN503780, CSCD6 56832, CSCD642512, CSCC163768 and CSAA806573 in Soil Final Determination by LC-MS/MS. Project Number: 1'000993/08/0CR, GRM030/04A. Unpublished study prepared by Syngenta Jea1otts Hill In ternational Research Centre. 144p.

MRID 47841951. Eversfield, S. (2007) Va1idation of a Method (Draft GRM030.02A) for the Determination of NOA449280 and SYN503780 in Soil Project Number: 1'013392/05/0CR, CEMR/3644. Unpublished study prepared by CEM An alytical Services, Ltd. 31 p.

MRID 47841952. Hagan, M. (2009) NOA449280 - Validation of Draft Method GRM030.04A for the Determination of NOA449280, SYN503780, CSCC163768, CSCD656832, CS CD642512 and CSAA806573 in Soil: Final Report. Project Number: T001384/09, 09SYN256/REP, ALS09SYN01/PRO. Unpublished study prepared by ALS Laboratory Group, Environmental. 109 p.

MRID 47841953 Oppilliart, S. (2009) NOA449280 - Valid ation of Analytical Method GRM030.04A for the Determination of Residues ofNOA449280 and Metabolites SYN503780, CSCD656832, CSCD642512, CSCC163768 and CSAA806573 in Soil Project Number: TK0014608/0CR, TK0014608/REG, S09/02700. Unpublished study prepared by ADME Bioanalyses. 163 p.

Ecological Effects MRIDs-Page 63 of 88- MRID 47842079. Hubbard PM and Beavers JB (2009), NOA449280: An acute oral toxicity study with the Northern Bobwhite. Laboratory Report Number 528-305. Wildlife International Ltd, Easton, Maryland, USA, 2009. Unpublished report. (Syngenta File No. NOA449280_11015).

MRID 47842080. Hubbard P.M., Martin K.H. & Beavers J.B. (2007). NOA449280 – A dietary LC 50 study with the Northern Bobwhite. Laboratory Report Number 528-249 . Wildlife International Ltd, Easton, Maryland, USA. Unpublished report. (Syngenta File No. NOA449280/0077).

MRID 47842081. Hubbard P.M., Martin K.H. & Beavers, J.B. (2007a). NOA449280 – A dietary LC 50 study with the Mallard. Laboratory Report Number 528-250. Wildlife International Ltd, Easton, Maryland, USA. Unpublished report. (Syngenta File No. NOA449280/0078).

MRID 47842082. Frey, L.T., Martin K.H., Beavers, J.B. & Jaber, M. (2008). NOA449280 – A reproduction study with the Northern Bobwhite. Laboratory Report Number 528-253. Wildlife International Ltd, Easton, Maryland, USA. Unpublished report. (Syngenta File No. NOA449280_10995).

MRID 47842084. Frey, L.T., Martin K.H., Beavers, J.B. & Jaber, M. (2009). NOA449280 – A reproduction study with the Mallard. Laboratory Report Number 528-289. Wildlife International Ltd, Easton, Maryland, USA. Unpublished report. (Syngenta File No. NOA4449280_11034).

MRID no. 47842085. Bätscher, R. (2007). NOA449280 - Acute toxicity to rainbow trout ( Oncorhynchus mykiss ) in a 96-hour static test. Laboratory Report Number B3 7091. RCC Ltd, Itingen, Switzerland. Unpublished report. (Syngenta File No. NOA449280/0087).

MRID no. 47842086. Bätscher, R. (2007a). NOA449280 - Acute toxicity to fathead minnow ( Pimephales promelas ) in a 96-hour static test. Laboratory Report Number B37135. RCC Ltd, Itingen, Switzerland. Unpublished report. (Syngenta File No. NOA449280/0084).

MRID no. 47842087. Gallagher, S. P., Kendall, T. Z., and H. O. Krueger (2008). NOA449280: An early life stage toxicity test with the fathead minnow (Pimephales promelas). Laboratory Report Number 528A-167. Wildlife International Ltd., Easton, MD, USA. Unpublished report. (Syngenta File No. NOA449280/0102).

MRID no. 47842088. Bätscher, R. (2007b), NOA449280 - Acute toxicity to Daphnia magna in a 48-hour immobilization test. Laboratory Report number B37056. RCC Ltd, Itingen, Switzerland. Unpublished report. (Syngenta File No. NOA449280/0083).

MRID no. 47842091. Bätscher, R. (2008). NOA449280 - Effect on survival, growth and reproduction of Daphnia

magna in a semi-static test over three weeks. Laboratory Report number B37078. RCC Ltd, Itingen, Switzerland. Unpublished report. (Syngenta File No. NOA449280/0092).

MRID no. 47842092. Bätscher, R. (2007c). NOA449280 - Toxicity to Pseudokirchneriella subcapitata (formerly Selenastrum capricornutum ) in a 96-hour algal growth inhibition test. Laboratory Report Number B36977. RCC Ltd, Itingen, Switzerland. Unpublished report. (Syngenta File No. NOA449280/0081).

MRID no. 47842093. Büche, C. (2008). NOA449280 - Toxicity to Anabaena flos-aquae in a 96 hour algal growth inhibition test. Laboratory Report Number B36990. RCC Lt d, Itingen, Switzerland. Un published report. (Syngenta File No. NOA449280/0082).

MRID no. 47842094. Büche, C. (2007). NOA449280 - Toxicity to Navicula pelliculosa in a 96 hour algal growth inhibition test. Laboratory Report Number B37012. RCC Lt d, Itingen, Switzerland. Un published report. (Syngenta File No. NOA449280/0085).

MRID no. 47842102. Minderhout, T., Kendall, T. Z., and H. O. Krueger. (2008). NOA449280: A 96-hour toxicity test with the marine diatom ( Skeletonema costatum ). Laboratory Report Number 528A-161. Wildlife International, Ltd., Easton, Maryland, USA. Unpublished report. (Syngenta File No. NOA449280/0093).-Page 64 of 88- MRID no. 47842095. Bätscher, R. (2007d). NOA449280 - Toxicity to the Aquatic Higher Plant Lemna gibba in a 7-Day Semi-Static Growth Inhibition Test. Laborator y Report Number B37034. RCC Ltd. Zelgliweg 1, 4452 Itingen, Switzerland. Unpublished report. (Syngenta file No. NOA449280/0071).

MRID no. 47842116. Peither, A. (2011). NOA449280 EC (A15749AD) - Toxicity to the aquatic higher plant Lemna gibba in a 7-day growth inhibition test, supplemented with testing for recovery of growth. Laboratory Report Number B95095. Harlan Laboratories Ltd., 4452 Itingen, Switzerland. Unpublished report. (Syngenta file no. A15749AD_10016).

MRID no. 47842096. IIA 8.7.1/01. Warmers, C. (2007): NOA449280 - Acute Oral and Contact Toxicity to the Honeybee Apis mellifera L. in the Laboratory. Laboratory Report Number 20071298/01-BLEU. Eurofins-GAB GmbH, Niefern-Öschelbronn, Germany. Unpublished report. (Syngenta file No. NOA449280/0065).

MRID no. 47842097. Stevens, J. (2009). NOA449280 EC (A15749AD) – A rate-response laboratory bioassay of the effects of fresh residues on the parasitic wasp Aphidius rhopalosiphi (Hymenoptera, Braconidae). Laboratory Report Number SYN-08-46. Mambo-Tox Ltd., 2 Venture Road, Chilworth Science Park, Southampton SO16 7NP, UK. Unpublished report. (Syngenta file No. A15749AD_10002).

MRID no. 47842118. Fallowfield, L. (2009). NOA449280 EC (A15749AD) – A rate-response laboratory bioassay of the effects of fresh residues on the predatory mite, Typhlodromus pyri (Acari: Phytoseiidae). Laboratory Report Number SYN-08-45. Mambo-Tox Ltd., 2 Venture Road, Chilworth Science Park, Southampton SO16 7NP, UK. Unpublished report. (Syngenta file No. A15749AD_10003).

MRID no. 47842150. Stevens, J, (2009a). NOA449280/S-metolachlor EC (A15936Z) – A rate response extended laboratory bioassay of the effects of fresh residues on the parasitic wasp Aphidius rhopalosiphi (Hymenoptera, Braconidae). Laboratory Report Number SYN-08-48. Mambo-Tox Ltd., 2 Venture Road, Chilworth Science Park, Southampton SO16 7NP, UK. Unpublished report. (Syngenta file No. A15936Z_10004).

MRID no. 47842098. Friedrich, S. (2008), NOA449280 - Acute toxicity to the earthworm Eisenia fetida

. Laboratory Report Number 07 10 48 035 S. BioChem agrar GmbH, Kupferstraße 6, D-04827 Gerichshain, Germany. Unpublished report. (Syngenta file No. NOA449280/0080). PMRA no. 2263386.

MRID no. 47842099. Schulz, L. (2009), NOA449280 SL (A16003E) - Effects on the activity of soil microflora (Nitrogen and carbon transformation tests). Laboratory Report Number 09 10 48 023 C/N. BioChem agrar, 04827 Gerichshain, Germany. Unpublished report. (Syngenta File No. A16003E_10002).

MRID no. 47842101. Gallagher, S., Kendall, T. and H. Krueger. (2008a). NOA449280 – A 96 Hour Static Acute Toxicity Test with the Sheepshead Minnow ( Cyprinodon variegatus). Laboratory Report Number 528A-159. Wildlife International Ltd, Easton, MD, USA. Unpublished report. (Syngenta File No. NOA449280/0101).

MRID no. 47842089. Gallagher, S., Kendall, T. and H. Krueger. (2008b). NOA449280 – A 96 hour static acute toxicity test with the saltwater mysid ( Mysidopsis bahia ). Laboratory Report Number 528A-158. Wildlife International Ltd, Easton, MD, USA. Unpublished report. (Syngenta File No. NOA449280/0095).

MRID no. 47842090. Gallagher, S., Kendall, T. and H. Krueger. (2008c). NOA449280 - A 96 hour shell deposition test with the eastern oyster ( Crassostrea virginica ). Laboratory Report Number 528A-160. Wildlife International Ltd, Easton, MD, USA. Unpublished report. (Syngenta File No. NOA449280/0096).

MRID no. 47842103. Porch, J. R., Martin, K. H. & H. O. Krueger. (2009). NOA449280 EC (A15749F) - Toxicity Effects on the Seedling Emergence of Terrestrial Non-Target Plant Species . Laboratory Report No: 528-265. Wildlife International Ltd., Easton, MD 21601, USA. Unpublished report. (Syngenta file No. A15749F_10001).

MRID no. 47842104. Porch, J. R., Martin, K. H. & H. O. Krueger. (2009a). NOA449280 EC (A15749F) - Toxicity Effects on the Vegetative Vigour of Terrestrial Non-Targ et Plant Species. Laboratory Report No: 528-266, Wildlife International Ltd., Easton, MD 21601, USA. Unpub lished report. (Syngenta file No. A15749F_10002).-Page 65 of 88- MRID no. 47842105. Seyfried, B. (2007). NOA449280 - Toxicity to activated sludge in a respiration inhibition test. Laboratory Report number B37157. RCC Ltd, Itingen, Switzer land. Unpublished report. (Syngenta File No. NOA449280/0088).

MRID no. 47842144. Rudolf R (2009). Screening Test for Acute Toxicity of CA3276A to Rainbow Trout (Onchorynchus mykiss) (96-hour exposure without feeding): Laboratory Report Number TK00480-09, 50513261. IBACON Institut für Biologische Analytik und Consuti ng IBACON GmbH. Unpublished report. (Syngenta file no. CA3276A_11271). PMRA no. 2263484.

MRID no. 47842145. Rudolf R (2009). Screening Test for Acute Toxicity of CA3276A to Daphnia magna Stauss (48 hours exposure without feeding): Laboratory Re port Number TK00480-09, 50512262. IBACON Institut für Biologische Analytik zund Consuting IBACON GmbH. Unpublished report. (Syngenta file no. CA3276A_11270).

MRID no. 47842146. Rudolf R (2009). Screening Test for Toxicity of CA3276A: A 72-hour algal growth

inhibition test with Pseudokirchneriella subcapitata (formerly Selanastrum capricornutum ) Laboratory Report Number TK00480-09, 50511260. IBACON Institut für Biologische Analytik zund Consuting IBACON GmbH. Unpublished report. (Syngenta file no. CA3276A_11272).

MRID no. 47842147. Höger S (2009). Screening Test for Toxicity of CSAA794198 to Lemna gibba . Laboratory Report Number TK0009423. Harlan Laboratories Ltd Zelgliweg 1 4452 Itingen I Switzerland. Unpublished report. (Syngenta file no. NOA449280_11043).

MRID no. 47842149. Höger S (2009). CSAA589691 - Toxicity to the Aquatic Higher Plant Lemna gibba in a 7- Day Growth Inhibition Test. Laboratory Report Number C6 5658. Harlan Laboratories Ltd.Zelgliweg 1 4452 Itingen / Switzerland. Unpublished report. (Syngenta file no. NOA412101_11214).

MRID no. 47842139. Höger S (2010). CSCC163768 - Toxicity to the Aquatic Higher Plant Lemna gibba in a 7- Day Growth Inhibition Test. Laboratory Report Number C6 2036. Harlan Laboratories Ltd.Zelgliweg 1 4452 Itingen / Switzerland. Unpublished report. (Syngenta file no. SYN504810_10001).

MRID no. 47842106. Boonstra, H., van Wijngaarden, R.P.A. and T.C.M. Brock (2010). NOA449280 – Outdoor Multi-Species Test with Aquatic M acrophytes. Laboratory Report Number ALT.HB.2008.1. ALTERRA, Wageningen University and Research Centre, Centre for Water and Climate, Wageningen, The Netherlands. Unpublished report. (Syngenta file no. NOA449280_11116).

MRID no. 47842121. Nair, S.K. (2012). Development of 84-Day Multi-Species Exposure Response Curves for NOA449280. Laboratory Report Number: E2-SYN1293-2012-01. E2 Consulting Engineers, Inc., Oak Ridge, TN 37830 USA. Unpublished report. (Syngenta file no. NOA449280_11147).

MRID no. 47842248. Kling, A. 2009. NOA449280 SL (A16003E)- Acute oral and contact toxicity to the honeybee Apis mellifera L. in the laboratory. Final report. Performing lab: Eurofins-GAB GmbH, Germany. Report no. S09- 01234. Sponsor: Syngenta, UK.

MRID no. 47842249. Friedrich, S. 2009. NOA449280 SL (A16003E) – Acute toxicity to the earthworm Eisenia fetida . Final report. Performing lab: BioChem agrar, Germany. Study number: 09 10 48 039 S. Sponsor: Syngenta,

UK.

MRID no. 47842242. Hoger, S. 2009. NOA449280 SL (200) (A16003E) – Acute toxicity to Daphnia magna in a 48-hour immobilization test. Performing lab: Harlan Laboratories Ltd, Switzerland. Study no. C40932. Sponsor: Syngenta, UK.

MRID no. 47842241. Hoger, S. 2009. NOA449280 SL (200) (A16003E) – Acute toxicity to rainbow trout ( Oncorhynchus mykiss ) in a 96-hour test. Final report. Performing lab: Harlan Laboratories Ltd., Switzerland. Study no. C40921. Sponsor: Syngenta, UK.-Page 66 of 88- MRID no. 47842250. Hubbard, P.M. an d Beavers, J.B. 2009. NOA449280 EC (A16003E) – An acute oral toxicity study with the Northern Bobwhite using a sequential testing procedure. Final report. Performing lab: Wildlife International Ltd. Easton, MD. Report no. 528-295. Sponsor: Syngenta, UK.

MRID no. 47842243. Hoger, S. 2009. NOA449280 SL (200) (A16003E) – Toxicity to Pseudokirchneriella subcapitata in a 96-hour algal growth inhibition test. Final report. Performing lab: Harlan Laboratories, Switzerland. Study no. C40908. Sponsor: Syngenta, UK.-Page 67 of 88-Appendix A. Proposed New Uses, BicyclopyroneProposed products for registration containing bicyclopyrone.ProposedNew End-UseProduct NameSummary Formulation Details:Formulation Typelb bicyclopyrone/gal of productApplication TypeCropsSYN-A16003EPA Reg. No. 100-RUAASoluble concentrate (18.5% a.i.)1.67GroundCorn (field corn, seed corn, silagecorn, yellow popcorn and sweet corn)SYN-A19707;Restricted Use productEPA Reg. No. 100-RUALMixed formulation capsule suspension andsuspension concentrate (0.65%)0.061GroundCorn (field corn, seed corn, silagecorn, yellow popcorn and sweet corn)1Also contains atrazine: 1.0 lb/gal., mesotrione: 0.24 lb/gal., andS-metolachlor: 2.14 lb/gal.-Page 68 of 88-Appendix B. Bicyclopyrone and its Environmental Transformation ProductsTable B1. Bicyclopyrone and its Environmental Transformation Products: Structuresand Maximum Concentrations by StudyCode NameChemical NameChemical StructureStudy TypeMRID(s)Maximum%AR (day)A,BFinal %AR(study length orlast intervaldetected)PARENTNOA449280BicyclopyroneIUPAC:4-hydroxy-3-[2-(2-methoxy-ethoxymethyl)-6-trifluoromethyl-pyridine-3-carbonyl]-bicyclo[3.2.1]oct-3-en-2-oneCAS:4-hydroxy-3-[[2-[(2-methoxyethoxy)methyl]-6-(trifluoromethyl)-3-pyridinyl]carbonyl]bicyclo[3.2.1]oct-3-en-2-oneCAS No.352010-68-5Formula:C19H20F3NO5MW:399.36 g/molSMILES Code:COCCOCc1c(ccc(n1)C(F)(F)F)C(=O)C2=C(C3CCC(C3)C2=O)OOCF3NOOHOOMeAerobic SoilMetabolism47842026478420334784203447842035Not Applicable1.3 (365)46.9 (365)24.7-75.6 (120; 6soils)2.8-57.7 (120; 4soils)6.0 (365)41.2-67.4 (120; 4Brazilian soils)AnaerobicSoilMetabolism4784202771.3 (149/119; nodegradationduring anaerobicphase)AerobicAquaticMetabolism478420734784207479.2-88.8 (105; 4systems)AnaerobicAquaticMetabolism478420734784207473.1-76.9 (105; 4systems)SoilPhotodegradation478420284784202941.4 (30)1.6-16.1 (12-15)Hydrolysis4784191996.0-98.0 (31)AqueousPhotolysis478419213.4 . pH 5(30)70.4 @ pH 7 (30)62.4 nat.wat. (30)TerrestrialFieldDissipation4784203847842039478420401.6-1.7μg/kg (3reps; 363)-Page 69 of 88-Code NameChemical NameChemical StructureStudy TypeMRID(s)Maximum%AR (day)A,BFinal %AR(study length orlast intervaldetected)MAJOR DEGRADATESCSCC163768SYN504810IUPAC:6-(Trifluoromethyl)pyridine2,3-dicarboxylic acidCAS: 6-trifluoromethylpyridine-2,3-dicarboxylic acidCAS No. 90376-94-6MW: 235.1 g/molFormula: C8H4F3NO4SMILES:c1cc(nc(c1C(=O)O)C(=O)O)C(F)(F)FNFFFOOHOOHAqueousPhotolysis4784192126.6@ pH 5 (30)2.9@ pH 7 (30)3.0 nat.wat. (30)26.6@ pH 5(30)2.9@ pH 7 (30)3.0 nat.wat. (30)SoilPhotolysis4784202911.7-17.8 (6-15)C10.7-17.8 (12-15)47842028 9.6 (30) 9.6 (30)835.4100Aerobic SoilMetabolism47842033(7 soils)DND-0.9 (79)ND (120)-0.5(365)47842034(5 soils)D0.7-1.2 (14) ND (120-365)47842035(4 soils)0.1(3, 120)-1.5(92)ND-0.08 (120)835.4300AerobicAquaticMetabolism47842073 1.7-2.8 (60) 0.15-0.85 (105)*NonGuideline*Aer. AquaticMetab. +Photodeg.4784207543.4 (29)-50.1(16)37.3-43.4 (29)835.4400AnaerobicAquaticMetabolism47842073 8.3-9.1 (365) 8.3-9.1 (365)835.6100TerrestrialFieldDissipation4784203847842039478420406.2 (3)NDND1.5 (14)NDND-Page 70 of 88-Code NameChemical NameChemical StructureStudy TypeMRID(s)Maximum%AR (day)A,BFinal %AR(study length orlast intervaldetected)CSAA456156CGA375529IUPAC:6-Trifluoro-methylpyridine-3-carboxylic acidCAS:6-Trifluoromethylpyridine-2,3-dicarboxylic acidFormula:C7H4F3NO2MW:191.108 g/molSMILES:c1cc(ncc1C(=O)O)C(F)(F)F*NonGuideline*Aer. AquaticMetab. +Photodeg.47842075 19.7-20.6 (29) 19.7-20.6 (29)CSAA589691(NOA412101)IUPAC:(1S,3R)-Cyclopentane-1,3-dicarboxylic acidCAS: (1S,3R)-Cyclopentane1,3-dicarboxylic acidCAS No. 876-05-1Formula:C7 H10 O4MW:158.1 g/molSMILES:C1CC(CC1C(=O)O)C(=O)OOHOOOHAqueousPhotolysis4784192126.3@pH 5 (18)18.7@ pH 7 (30)14.5 nat.wat.(30)21.1@pH 5(30)18.7@ pH 7 (30)14.5 nat.wat. (30)SoilPhotolysis47842028 1.4 (0) 1.4 (0)CSCD642512(SYN545859)IUPAC:2-[[3-(2,4-Dioxobicyclo[3.2.1]octane-3-SoilPhotolysis47842029 2.2-4.1 (4-9) ND-3.2 (15)-Page 71 of 88-Code NameChemical NameChemical StructureStudy TypeMRID(s)Maximum%AR (day)A,BFinal %AR(study length orlast intervaldetected)carbonyl)-6-(trifluoromethyl)-2-pyridyl]methoxy]acetic acidCAS: [3-(2-Hydroxy-4-oxobicyclo[3.2.1]oct-2-ene-3-carbonyl)-6-trifluoromethylpyridin-2-ylmethoxy]-aceticacidFormula:C18H16F3NO6MW: 399.3 g/molSMILES:c1cc(nc(c1C(=O)C2C(=O)C3CCC(C3)C2=O)COCC(=O)O)C(F)(F)F47842028 6.2 (30) 6.2 (30)835.4100Aerobic SoilMetabolism47842033(7 soils)D0.7 (35)-5.9(120)ND (365)-5.9(120)ONOOFFFOOHOH47842034(5 soils)D1.2 (50)-6.0(120)0.6-6.0 (120)47842035(4 soils)1.2 (28)-12.1(92)ND-10.84 (120)835.4200AnaerobicSoilMetabolism47842027 2.9 (89) 2.3 (119)835.6100TerrestrialFieldDissipation478420384784203947842040ND2.5 (3)0.7 (120)ND1.2 (14)0.7 (120)CSCD656832*IUPAC:3-Hydroxy-6-Soil 47842029 7.0-8.0 (12-15) 5.8-8.0 (12-15)-Page 72 of 88-Code NameChemical NameChemical StructureStudy TypeMRID(s)Maximum%AR (day)A,BFinal %AR(study length orlast intervaldetected)(SYN545680)*This compound willbe included as aresidue of concernin the ecological riskassessment.(trifluoromethyl)pyridine-2-carboxylic acidCAS: 3-Hydroxy-6-trifluoromethyl-pyridine-2-carboxylic acidFormula:C7H4F3NO3MW:207.1 g/molSMILES:c1cc(nc(c1O)C(=O)O)C(F)(F)FPhotolysis47842028 4.8 (30) 4.8 (30)835.4100Aerobic SoilMetabolism47842033(7 soils)D2.8-9.8 (79) 3.5-7.9 (120)47842034(5 soils)D0.1(79)-14.4(120)ND-12.2(120)47842035(4 soils)0.2(64)-1.4(120) ND-1.45 (120)835.6100TerrestrialFieldDissipation47842038478420394784204011.8 (21)NDND2.3 (180)NDNDSYN503780(CSAA794148)IUPAC:2-(2-Methoxyethoxymethyl)-6-(trifluoromethyl)-nicotinicacidCAS: 3-pyridinecarboxylicAqueousPhotolysis478419216.3@ pH 5 (10)2.9@ pH 7 (30)4.9 nat.wat.(30)1.9@ pH 5 (30)2.9@ pH 7(30)4.9 nat.wat. (30)SoilPhotolysis4784202935.8-62.5 (3-15)C35.8-62.5 (12-15)-Page 73 of 88-Code NameChemical NameChemical StructureStudy TypeMRID(s)Maximum%AR (day)A,BFinal %AR(study length orlast intervaldetected)acid, 2-[(2-methoxyethoxy)methyl]-6-(trifluoromethyl)-Formula:C11H12F3NO4MW:279.2 g/molSMILES:COCCOCc1c(ccc(n1)C(F)(F)F)C(=O)O47842028 25.3 (30) 25.3 (30)835.4100Aerobic SoilMetabolism47842033(7 soils)D0.5 (120)-6.3(50)ND-5.8 (120)47842034(5 soils)D0.6 (7)- 4.2 (21) ND-2.4 (120)47842035(4 soils)1.4(92)-2.1(6) ND-1.96 (120)835.4200AnaerobicSoilMetabolism47842027 3.4 (60) 2.9 (119)835.4300AerobicAquaticMetabolism478420732.3 (105)-2.9(60)1.5-2.5 (105)*NonGuideline*Aer. AquaticMetab. +Photodeg.47842075 3.4 (3)-4.4 (16) ND-1.5 (29)835.4400AnaerobicAquaticMetabolism478420733.8 (182)-4.3(91)2.9-4.0 (365)-Page 74 of 88-Code NameChemical NameChemical StructureStudy TypeMRID(s)Maximum%AR (day)A,BFinal %AR(study length orlast intervaldetected)835.6100TerrestrialFieldDissipation4784203847842039478420407.9 (1)20.4 (3,7)14.0 (1)1.3 (180)5.8 (28)1.5 (21)CO2Carbon dioxideFormula:CO2MW:44.1 g/molSMILES:O=C=OOOAqueousPhotolysis478419214.7 @ pH 5 (30)4.7 @ pH 7 (30)0.6 nat.wat. (30)4.7 @ pH 5 (30)4.7 @ pH 7 (30)0.6 nat.wat. (30)SoilPhotolysis47842029 1.8-2.5 (12-15) 1.8-2.0 (12-15)47842028 20.1 (30) 20.1 (30)835.4100Aerobic SoilMetabolism47842026(1 soil)75.8 (365) 75.8 (365)47842033(7 soils)D4.8-44.1 (120) 4.8-44.1 (120)47842034(5 soils)D10.7-65.8 (120) 10.7-65.8 (120)47842035(4 soils)11.4 (120)-26.2(120)11.4 (120)-26.2(120)835.4200AnaerobicSoilMetabolism478420278.7 (89) 7.6 (89)835.4300Aerobicaquaticmetabolism478420731.0-1.4 (105) 1.0-1.4 (105)478420742.6 (60)-4.5(105)2.5-4.5 (105)*NonGuideline*Aer. AquaticMetab. +Photodeg.47842075 0.5-4.3 (29) 0.5-4.3 (29)835.4400AnaerobicAquaticMetabolism478420730.2-0.3 (365) 0.2-0.3 (365)478420743.1 (182)-7.0(365)2.7-7.0 (365)-Page 75 of 88-Code NameChemical NameChemical StructureStudy TypeMRID(s)Maximum%AR (day)A,BFinal %AR(study length orlast intervaldetected)MINOR DEGRADATESCSAA806573(NOA451778)IUPAC:2-Hydroxymethyl-6-trifluoromethyl-nicotinic acidCAS: 2-Hydroxymethyl-6-trifluoromethyl-nicotinic acidFormula:C8 H6 F3 N O3MW:221.1 g/molSMILES:c1cc(nc(c1C(=O)O)CO)C(F)(F)FNOOHCF3OHAqueousPhotolysis478419215.5@ pH 5 (30)ND @ pH 72.3 nat.wat (30)5.5@ pH 5 (30)ND@ pH 72.3 nat.wat.(30)835.4200AnaerobicSoilMetabolism47842027 1.2 (119) 1.2 (119)835.4400AnaerobicAquaticMetabolism47842073 0.5-2.0 (91) ND (365)835.6100TerrestrialFieldDissipation4784203847842039478420402.1 (1)ND3.5 (4)1.8 (7)ND3.5 (4)CSAA915194(NOA454598)IUPAC:4-Hydroxy-3-[2-(2-hydroxy-ethoxymethyl)-6-trifluoromethyl-pyridine-3-carbonyl]-bicyclo[3.2.1]oct-3-en2-oneCAS: 4-Hydroxy-3-[2-(2-hydroxy-ethoxymethyl)-6-trifluoromethyl-pyridine-3-carbonyl]-bicyclo[3.2.1]oct-3-en-2-oneFormula:C18H18F3NO5MW:385.3g/molSMILES:c1cc(nc(c1C(=O)C2=C(C3CCC(C3)C2=O)O)COCCO)C(F)(F)F835.4300AerobicAquaticMetabolism47842073 1.6-2.0 (105) 1.6-2.0 (105)*NonGuideline*Aer. AquaticMetab. +Photodeg.47842075 7.1-7.6 (6) 0.5-5.1 (29)835.4400AnaerobicAquaticMetabolism478420731.2 (365)-1.6(182)1.2-1.3 (365)OHONOOHOCF3-Page 76 of 88- 

## Appendix C. SWCC Results

SWCC Output File

Variable Volume Water Model, SWCC Compatible Version

*******************************************

Performed on: 9/ 9/2014 at 13:44

Peak 1-in-10 = 4.04 ppb Chronic 1-in-10 = 3.09 ppb Simulation Avg = 2.30 ppb 4-day avg 1-in-10 = 4.03 ppb 21-day avg 1-in-10 = 4.01 ppb 60-day avg 1-in-10 = 3.92 ppb 90-day avg 1-in-10 = 3.83 ppb

Benthic Pore Water Peak 1-in-10 = 3.50 ppb Benthic Pore Water 21-day avg 1-in-10 = 3.50 ppb Benthic Conversion Factor = 0.960 -Pore water (ug/L) to
(total mass, ug)/(dry sed mass,kg)

Benthic Mass Fraction in Pore Water = 0.386

YEAR Peak 4-day 21-day 60-day 90-day Yearly Avg Benthic Pk Benthic 21-day

1 8.38E-01 8.35E-01 8.29E-01 8.07E-01 7.88E-01 4.34E-01

6.74E-01 6.74E-01

2 9.73E-01 9.70E-01 9.65E-01 9.40E-01 9.20E-01 7.75E-01

8.55E-01 8.54E-01

3 9.54E-01 9.52E-01 9.44E-01 9.23E-01 9.02E-01 8.06E-01

8.64E-01 8.63E-01

4 1.76E+00 1.75E+00 1.73E+00 1.69E+00 1.65E+00 1.22E+00

1.47E+00 1.47E+00

5 2.63E+00 2.63E+00 2.60E+00 2.54E+00 2.48E+00 1.94E+00

2.24E+00 2.24E+00

6 3.69E+00 3.68E+00 3.65E+00 3.57E+00 3.48E+00 2.76E+00

3.16E+00 3.16E+00

7 2.97E+00 2.97E+00 2.95E+00 2.95E+00 2.98E+00 2.73E+00

3.00E+00 3.01E+00

8 2.55E+00 2.55E+00 2.54E+00 2.48E+00 2.48E+00 2.30E+00

2.51E+00 2.53E+00

9 3.51E+00 3.50E+00 3.46E+00 3.42E+00 3.35E+00 2.68E+00

3.06E+00 3.06E+00

10 3.03E+00 3.02E+00 2.99E+00 2.93E+00 2.87E+00 2.69E+00

2.88E+00 2.89E+00

11 3.59E+00 3.58E+00 3.55E+00 3.47E+00 3.39E+00 2.84E+00

3.16E+00 3.16E+00

12 2.81E+00 2.81E+00 2.82E+00 2.84E+00 2.87E+00 2.53E+00

2.90E+00 2.92E+00

13 2.64E+00 2.64E+00 2.61E+00 2.55E+00 2.49E+00 2.24E+00

2.39E+00 2.39E+00

14 4.08E+00 4.07E+00 4.05E+00 3.96E+00 3.87E+00 3.00E+00

3.51E+00 3.51E+00-Page 77 of 88- 

### 15 3.23E+00 3.23E+00 3.24E+00 3.26E+00 3.29E+00 2.90E+00

3.32E+00 3.33E+00

16 4.68E+00 4.67E+00 4.63E+00 4.51E+00 4.41E+00 3.42E+00

3.98E+00 3.98E+00

17 4.25E+00 4.24E+00 4.20E+00 4.09E+00 3.99E+00 3.65E+00

3.89E+00 3.89E+00

18 3.33E+00 3.33E+00 3.33E+00 3.36E+00 3.39E+00 3.03E+00

3.44E+00 3.46E+00

19 2.67E+00 2.67E+00 2.66E+00 2.63E+00 2.66E+00 2.45E+00

2.71E+00 2.73E+00

20 2.29E+00 2.28E+00 2.26E+00 2.21E+00 2.20E+00 2.05E+00

2.24E+00 2.25E+00

21 2.41E+00 2.40E+00 2.38E+00 2.33E+00 2.28E+00 2.00E+00

2.17E+00 2.17E+00

22 3.68E+00 3.67E+00 3.64E+00 3.56E+00 3.49E+00 2.73E+00

3.17E+00 3.17E+00

23 3.66E+00 3.66E+00 3.63E+00 3.58E+00 3.51E+00 3.10E+00

3.36E+00 3.36E+00

24 3.17E+00 3.16E+00 3.14E+00 3.08E+00 3.02E+00 2.83E+00

3.02E+00 3.04E+00

25 2.83E+00 2.83E+00 2.80E+00 2.74E+00 2.69E+00 2.50E+00

2.66E+00 2.65E+00

26 2.30E+00 2.30E+00 2.30E+00 2.31E+00 2.33E+00 2.08E+00

2.36E+00 2.37E+00

27 2.16E+00 2.15E+00 2.13E+00 2.08E+00 2.04E+00 1.84E+00

1.97E+00 1.97E+00

28 2.52E+00 2.52E+00 2.50E+00 2.44E+00 2.38E+00 1.99E+00

2.20E+00 2.20E+00

29 1.97E+00 1.97E+00 1.98E+00 1.99E+00 2.01E+00 1.81E+00

2.04E+00 2.05E+00

30 1.81E+00 1.81E+00 1.80E+00 1.77E+00 1.73E+00 1.58E+00

1.69E+00 1.69E+00

**************************************************************************

************************** Effective compartment halflives averaged over simulation duration:

zero washout 0 water col metab halflife (days) = 997.620816648772 zero hydrolysis 0 photolysis halflife (days) = 6714.02721266894 volatile halflife (days) = 1852047775.80744 total water col halflife (days) = 868.562743557013

zero burial 0

zero benthic metab 0 zero benthic hydrolysis 0 zero benthic total degradation 0

*********************************************************************** Fractional Contribution of Transport Processes to Waterbody & Total Mass
(kg):

Due to Runoff = 0.9629 0.4315

Due to Erosion = 0.0037 0.1637E-02

Due to Drift = 0.0335 0.1500E-01-Page 78 of 88- 

### *********************************************************************** Flow in/out Characteristics of Waterbody: Average Daily Runoff Into Waterbody (m3/s) = 6.652821823241803E-004
Baseflow Into Waterbody (m3/s) = 0.000000000000000E+000 Average Daily Flow Out of Waterbody (m3/s) = 6.652821823241945E-004

***********************************************************************

Inputs: 14.75 = oc partitioning coefficient

667.2 = water column half Life 20.00 = reference temp for water column degradation

0.000 = benthic Half Life 20.00 = Reference temp for benthic degradation
2.000 = Q ten value 50.10 = photolysis half life 40.00 = reference latitude for photolysis study 0.000 = hydrolysis half life

399.4 = molecular wt
0.3800E-07 = vapor pressure 0.1190E+06 = 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



# Summary of Water Modeling of Bicyclopyrone and the USEPA

Standard Pond

Estimated Environmental Concentrations for bi cyclopyrone are presented in Table 1 for the USEPA standard pond with the NECornStd field s cenario. A graphical presentation of the yearto-year peaks is presented in Figure 1. These values were generated with the Surface Water Concentration Calculator (SWCC Version 1.106) . Critical input values for the model are

summarized in Tables 2 and 3. This model estimates that about 3% of bicyclopyr one applied to the field eventually reaches the-Page 79 of 88- 

### water body. The main mechanism of transport from the field to the water body is by runoff (96.3% of the total transport), followed by spray drift (3.35%) and erosion (0.37%). In the water body, pesticide dissipates with an effective water column half-life of 868.6 days. (This value does not include diss ipation by transport to the be nthic region; it includes only processes that result in removal of pesticide from the complete system.) The main source of dissipation in the water column is metabolism (effective average half-life = 997.6 days) followed by photolysis (6714 days) and volat ilization (1.852048E+09 days). In the benthic region, pesticide is stable. Most of the pesticide in the benthic region (61%) is

sorbed to sediment rather than in the pore water.

Table 1. Estimated Environmental Concen trations (ppb) for bicyclopyrone.

Peak (1-in-10 yr) 4.04

4-day Avg (1-in-10 yr) 4.03

21-day Avg (1-in-10 yr) 4.01

60-day Avg (1-in-10 yr) 3.92

365-day Avg (1-in-10 yr) 3.09

Entire Simulation Mean 2.30

Table 2. Summary of Model Inputs for bicyclopyrone.

Scenario NECornStd

Cropped Area Fraction 1

Kd F 

### (ml/g) 0.59

Water Half-Life (days) @ 20 °C 667.2

Benthic Half-Life (days) @ 20 °C 0

Photolysis Half-Life (days) @ 40

°Lat 50.1

Hydrolysis Half-Life (days) 0

Soil Half-Life (days) @ 20 °C 213.2

Foliar Half-Life (days) 0

Molecular Wt 399.4

Vapor Pressure (torr) 3.8e-8

Solubility (mg/l) 119e3

Table 3. Application Schedule for bicyclopyrone.

Date (Days

Since Type Amount (kg/ha) Eff. Drift-Page 80 of 88- 

### Emergence)

-7 Ground 0.05 0.99 0.01

Figure 1. Yearly Peak Concentrations-Page 81 of 88- 

## Appendix D. Groundwater Modeling Results

SCIGROW Output



### SCIGROW

VERSION 2.3

ENVIRONMENTAL FATE AND EFFECTS DIVISION

OFFICE OF PESTICIDE PROGRAMS

U.S. ENVIRONMENTAL PROTECTION AGENCY

SCREENING MODEL

FOR AQUATIC PESTICIDE EXPOSURE

SciGrow version 2.3 chemical:bicyclo 2

time is 8/21/2014 11:46:13

‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐ ‐‐‐‐‐‐‐‐‐‐ Application Number of Total Use Koc Soil Aerobic

rate (lb/acre) applications (lb/acre/yr) (ml/g) metabolism (days)

‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐ ‐‐‐‐‐‐‐‐‐‐ 0.045 1.0 0.045 7.00E+00 125.5

‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐ ‐‐‐‐‐‐‐‐‐‐

groundwater screening cond (ppb)
= 1.32E+00

************************************************************************

PRZM-GW Output



# Groundwater Analysis for Bicyclopy rone and the Wisconsin Corn -

WI Central Sands Scenario

Estimated groundwater concentrations and break through times for bicyclopyrone are presented

in Table 1 for the Wisconsin Corn - WI Cent ral Sands groundwater scenario. A graphical presentation of the daily concentr ations in the aquifer is presente d in Figure 1. These values were generated with the PRZM-GW (Version 1.07). Critical input values for the model are

summarized in Tables 2 and 3. To achieve br eakthrough to groundwater, an extended weather file (100 years) was used, as breakthrough did not occur using the standard 30-yr modeling run.

Table 1. Groundwater Results for Bicyclopyr one and the Wisconsin Corn - WI Central

Sands Scenario.

Peak Concentration (ppb) 7.95

Post-Breakthrough Mean Concentration (ppb) 7.33

Entire Simulation Mean Concentration (ppb) 5.05

Average Breakthrough Time (days) 12079.23

Throughputs 2.993735-Page 82 of 88- 

### Table 2. Chemical Properties for Gro undwater Modeling of Bicyclopyrone.

Kd (ml/g) 0.59

Surface Soil Half Life (days) 213.2

Hydrolysis Half Life (days) 0

Diffusion Coefficint Air (cm2/day) 0.0

Henry's Constant 0.0

Enthalpy (kcal/mol) 0.0

Table 3. Pesticide application scheme used for Bicyclopyrone. This application scheme was applied every year of the simulation.

Application Date

(Month/Day) Application Method Application Rate

(kg/ha)

04/30 Ground application with mass distribution increasing proportionally with depth to 4 cm 0.05

Figure 1. Aquifer Breakthrough Curve for Bi cyclopyrone and the Wisconsin Corn - WI

Central Sands Scenario-Page 83 of 88- 

## Appendix E. Example STIR (v. 1.0) input and output data-Page 84 of 88-Appendix F. Ecotoxicity data gaps and uncertaintiesTable 1. Aquatic ecotoxicity data gaps and uncertainties.GuidelineData RequirementTestSubstanceMRIDEPA StudyClassificationAreAdditionalDataNeeded?Endpoints850.1350Estuarine/marineinvertebrates life-cycleNOA449280TGAI(94.5%)No1N/A850.1400Estuarine/marine fishearly-life stageNOA449280TGAI(94.5%)-- --No1N/AN/A = Data are not available1ACR values have been calculated in absence of dataTable 2. Terrestrial ecotoxicity data gaps and uncertainties.GuidelineData RequirementTestSubstanceMRIDEPA StudyClassificationAreAdditionalDataNeeded?Endpoints-Page 85 of 88-GuidelineData RequirementTestSubstanceMRIDEPA StudyClassificationAreAdditionalDataNeeded?Endpoints850.2100Acute oral toxicity tobirdsCanary(Serinus canaria)NOA449280TGAI(94.5%)47842078 SupplementalYesLD50= 209 mg a.i./kg bw14-day testOECD 237and NonGuidelineHoney bee larval acuteand chronic oraltoxicityNOA449280TGAI(94.5%)-- --YesN/ANonGuidelineHoney bee adultchronic oral toxicityNOA449280TGAI(94.5%)-- --YesN/A-Page 86 of 88- 

## Appendix G. Example T-REX (v . 1.5.2) input and output data

TREX MODEL INPUTS You must enable macros for this spreadsheet to work correctly

These values will be used in the calculation of exposure estimates for foliar, granular, liquid and/or seed applications of pesticides.

Application No. Rate

Chemical Name: A pplication Rate (lb ai/acre ) 1

Seed Treatment? (Check if yes) FALSE Seeding Rate (lbs/acre) 2

Use: 3

Product name and form: 4

% A.I. (leading zero must be entered for formulations <1% a.i.): 5

Application Rate (lb ai/acre) 0.045 6

Half-life (days): 35 7

Application Interval (days): 8

Number of Applications: 1 9

Are you assessing applications with

variable rates or intervals? no 10

11

12

What body weight range is assessed (grams)? Birds Mammals 13

Small 20 15 14

Medium 100 35 15

Large 1000 1000 16

17
18

19 94.50%

Assessed Species Inputs (optional, use defaults for RQs for national level assessments) You MUST specify application day in Columns F and G - you may enter up to 30 applications Chemical Identity and Application Information

Bicyclopyrone

Corn

Bicyclopyrone

Avian

Endpoint Toxicity value Indicate test species

below Optional Test Organism Body weight (g) Optional Test Species Name Toxicity Value Reference (MRID)

LD50 (mg/kg-bw) 1206.00 1

LC50 (mg/kg-diet) 5550.00 2

NOAEL (mg/kg-bw) 1

NOAEC (mg/kg-diet) 35.00 2

1.15

Mammalian 1

Acute Study Chronic Study

350 350

Endpoint Toxicity value Reference (MRID)
LD50 (mg/kg-bw) 5000.00

LC50 (mg/kg-diet)

Reported Chronic Endpoint 2.15 1

Is dietary concentration (mg/kg-diet) reported from the

available chronic mammal study? (yes or no) yes

yes

Enter dietary concentration (mg/kg-diet) 25.00

Estimated Chronic Diet Concentration Equivalent to Reported Chronic Daily Dose 25 mg /k g- di e t b ase d on
standard FDA lab rat

conversion Enter the Mineau et al. Scaling Factor

Size (g) of mammal used in toxicity study

mg/kg-bw Bobwhite quail

Mallard duck

Bobwhite quail

Mallard duck-Page 87 of 88- EEC RQ EEC RQ EEC RQ EEC RQ EEC RQ EEC RQ

20 868.84 11.62 0.01 5.33 0.01 6.54 0.01 0.73 0.00 4.55 0.01 0.16 0.00

100 1106.07 6.63 0.01 3.04 0.00 3.73 0.00 0.41 0.00 2.60 0.00 0.09 0.00

1000 1562.37 2.97 0.00 1.36 0.00 1.67 0.00 0.19 0.00 1.16 0.00 0.04 0.00

EEC RQ EEC RQ EEC RQ EEC RQ EEC RQ

5550 10.21 0.00 4.68 0.00 5.74 0.00 0.64 0.00 4.00 0.00

EEC RQ EEC RQ EEC RQ EEC RQ EEC RQ

35 10.21 0.29 4.68 0.13 5.74 0.16 0.64 0.02 4.00 0.11

EEC RQ EEC RQ EEC RQ EEC RQ EEC RQ EEC RQ

15 10989.15 9.73 0.00 4.46 0.00 5.47 0.00 0.61 0.00 3.811167106 0.0003 0.1351 1E-05

35 8891.40 6.73 0.00 3.08 0.00 3.78 0.00 0.42 0.00 2.634026337 0.0003 0.0934 1E-05

1000 3845.80 1.56 0.00 0.71 0.00 0.88 0.00 0.10 0.00 0.610708241 0.0002 0.0217 6E-06

EEC RQ EEC RQ EEC RQ EEC RQ EEC RQ

0 10.21 #DIV/0! 4.68 #DIV/0! 5.74 #DIV/0! 0.64 #DIV/0! 4.00 #DIV/0!

EEC RQ EEC RQ EEC RQ EEC RQ EEC RQ

25 10.21 0.41 4.68 0.19 5.74 0.23 0.64 0.03 4.00 0.16 Table X. Upper Bound Kenaga, Acute Mammalian Dietary Based Risk Quotients
EECs and RQs

Arthropods

Table X. Upper Bound Kenaga, Chronic Mammalian Dietary Based Risk Quotients
EECs and RQs Arthropods

Size class not used for dietary risk quotients NOAEC
(ppm) Size class not used for dietary risk quotients Arthropods

Table X. Upper Bound Kenaga, Chronic Avian Dietary Based Risk Quotients

EECs and RQs

Broadleaf Plants EECs and RQs EECs and RQs Summary of Risk Quotient Calculations Based on Upper Bound Kenaga EECs

Arthropods Short Grass Size class not used for dietary risk quotients

NOAEC
(ppm) Tall Grass

LC50
(ppm) Short Grass Size

Class
(grams) Adjusted

LD50 Short Grass

Fruits/Pods/Seed

s Tall Grass Arthropods Adjusted

LD50

Size class not used for dietary risk quotients

Table X. Upper Bound Kenaga, Acute Mammalian Dose-Based Risk Quotients LC50

Granivore Tall Grass Broadleaf Plants Fruits/Pods/Seeds Arthropods

Short Grass Tall Grass Broadleaf Plants Fruits/Pods/Seed Broadleaf Plants Fruits/Pods/Seed

s Short Grass Tall Grass Broadleaf Plants Fruits/Pods/Seed

s Broadleaf Plants Fruits/Pods/Seeds Granivore Table X. Upper Bound Kenaga, Acute Avian Dose-Based Risk Quotients

EECs and RQs

Short Grass Tall Grass Size

Class
(grams)

Table X. Upper Bound Kenaga, Subacute Avian Dietary Based Risk Quotients-Page 88 of 88- 

## Appendix H. Example TerrPlant (v . 1.2.2) input and output data

TerrPlant v. 1.2.2 Green values signify user inputs (Tables 1, 2 and 4). Input and output guidance is in popups indicated by red arrows.

Parameter

Chemical Name

PC code

Use Application Method

Application Form S o l u bilit y i n W a t er ( ppm )

Input Parameter Symbol Value (user inputs) Units

Application Rate A 0.045 lbs ai/A

Incorporation I 1 none
Runoff Fraction R 0.05 none

Drift Fraction D 0.01 none

Equation EEC

(A/I)*R 0.00225 (A/I)*R*10 0.0225

A *D 0.00045 ((A/I)*R)+(A*D) 0.0027 ((A/I)*R*10)+(A*D) 0.02295

Plant type EC 25 NOAEC EC 25 NOAEC

Monocot 0.074 0.067 0.02 0.017

Dicot 0.005 0.002 0.001 0.0002

Plant Type Listed Status Dry Semi-Aquatic Spray Drift

Monocot non-listed <0.1 0.31 <0.1

Monocot listed <0.1 0.34 <0.1

Dicot non-listed 0.54 4.59 0.45

Dicot listed 1.35 11.48 2.25 Table 3. EECs for Bicyclopryone. Units in lbs ai/A.

Runoff to dry areas Runoff to semi-aquatic areas Spray drift Total for dry areas Table 1. Chemical Identity.

Bicyclopryone

Corn

Table 2. Input parameters used to derive EECs. Ground Spray liquid

119000 18986 User Inputs

*If RQ > 1.0, the LOC is exceeded, resulting in potential for risk to that plant group. Vegetative Vigor Seedling Emergence

Table 5. RQ values for plants in dry and semi-aquatic areas exposed to Bicyclopryone through runoff and/or spray drift.* Table 4. Plant survival and growth data used for RQ derivation. Units are in lbs ai/A. All values are user inputs Description

Total for semi-aquatic areas