## Environmental Fate and Ecological Risk Assessment for Section 3 

## and IR-4 Registration of New 

## Uses of

## Zeta-cypermethrin

ci CH,

Date: May 8,2007 PC Code: 129064 DP Barcode: D335628, D335629, D335630 and D335631 Prepared by: United States Environmental Protection Agency N.E.Federoff, Wildlife Biologist OfficeofPesticide Programs JosC L. Meltndez, Chemist EnvironmentalFate and Effects Division Reviewed by: Environmental Risk Branch V Mah T. Sharnim,Branch Chief Ariel Rios Building Environmental Risk Branch V 1200Pennsylvania Ave.,NW Mail Code 7507P Washington, DC 20460

### MEMORANDUM SUBJECT: Section 3 

### and IR-4 Registration of Zeta-cypermethrin (FURY and MUSTANG) for use on Wild rice, Safflower, Citrus and Okra. TO: 

### Daniel Rosenblatt, Chief Richard Gebken, Chief George Larocca, Chief Sidney Jackson, Risk Manager Reviewer Linda DeLuise, Risk Manager Reviewer Registration Division (7913P, 72 19P and 7237P) -9 

### FROM: 

### N.E. Federoff, Wildlife Biologist 

### ep Josk Luis Melendez, Chemist -//6 d~ -aM 

### Environmental Risk Branch V Environmental Fate and Effects Division (7507P) THROUGH: 

### Mah 

### T. Shamim, Ph.D., Chief Environmental Risk Branch V 

### Environmental Fate and Effects Division (7507P) EFEDhascompletedthe assessmentfor wild rice forzeta-cypermethnn. EFEDwill relyonprevious assessments for use of zeta-cypermethrin on Safflower, Okra and Citrus. Water Column Exposure for Wild Rice 

## - Acute and Chronic Risk 

### The Rice Model ("Policy for Estimating Aqueous Concentrations from Pesticides Labeled for Use on Rice," 10129102Memorandum, From Steven Bradbury, To EFED), was utilized to obtain column water EECs for Wild Rice. Acute and chronic RQs for aquatic animals in the water column are summarized in the tables below. Based on the toxicity data for all cypermethrin products (alpha-, beta-, theta-, and zeta-cypermethrin), there ispotential for acuterisk to nontarget listed and non-listed freshwater and estuarinelmarinefish and invertebrates resulting from spray applications of zeta-cypermethrin to wild rice. Based on a comparison of acute LCs0values, invertebrates appear to be the most sensitive aquatic animals. Acute RQs for invertebrates (854.73 - 

### 1127.77)are much higher than those derived for fish (4.27 - 

### 10.41). As anticipated, based on a comparison ofthe chronic NOAEC values, chronic RQs derived for aquatic invertebrates (2038 -

### 2695) are much higher than those derived for fish (1.8 -

### 4.3).

### Previous and current assessment 

### The following attached assessment (DP Barcodes: D290875, D292524, D3 121 36, D3 12 138, D312470, D3 12474,D3 12476,D3 15421,D3 18775,D322954andD322955)maybeused inplace of a new terrestrial and aquatic assessment forthe currently proposed new uses of zeta-cypermethrin (DP Barcodes: D335628, D335629,D335630 and D335631).

### Theprevious assessment for cilantro, leafy vegetables, headlstem brassica,poine and stonehit canbe used in place ofa new assessment for okra. Grass, forage, hay group, rapeseed and canola canbeused in place ofcitrus and wild rice. Non-grass forage, feed and fodder can be used inplace of safflower.Therates are the same (0.2 lbs ailA1seasonfor 4 applications for citrus and wild rice, 0.3 1bsailA1seasonfor 6 applications for okra and 0.15 lbs ai/A/season for 3 applications for safflower) for the crops groupings mentioned above. In 

### addition, previous assessments, other than the onepresently attached, also had similarrates for othercrops (ie.,corn, alfalfa, cotton, etc). A listing of endangered speciesisnot attachedbecause the listingwould be extremely large in volume.

Acute RQs for freshwater and estuarinelmarine fish and invertebrates exposed to zeta-cypermethrin 

# ."

Terrestrial EECs and resulting RQs can be used from the attached assessment since use rates were the same.A tableofprevious and current aquaticEECsareprovided below for comparison purposes. EstuarinelMarine Invertebrate

Acute RQ

854.73 '" Estuarinemarine Fish Acute RQ

4.27 h' * CropUse

Wlld R~ce

a RQs = EEC /LC v,,whe~e EFCs ate the peak concentlatlons In sutface water gene~ated from PRZMIEXAMS for the varlous clop scenarios consldered. and acute toxlclty tefe~ence values aleas follows fieshwatel fish, lambow t~out 96-h~ LC5,, =0 39 pg a I IL, freshwater lnvertebrates amphlpod 96-h~ LC,,,=0 0036 kig a I /L 

### .estuar~~ielmar~ne fish,sheepshead mlnnow 96-hou~ LC,(,=0 95 pg a I IL. and est~~arlnel~nar~ne ~nvel-tehlates, lnys~d sh~nnp 96-hou~ LC,,, =0 00475 pg a I /L " RQs meet 01 exceed I OC for acute iisk (LOC 0 5)

RQs meet or exceed LOC fo~ acute test1lcted use (LOC 0 I ) "QS meet 01 exceed LOC fo~ acute endangered speclea (LOC 0 05)
ChronicRQs for freshwater and estuarinetmarinefish and invertebratesexposed to zeta-cypermethrin

# .' Freshwater Fish Acute RQ

10.41 "" Rice Model Acute Scenario

EECs @pb) 4 06 Freshwater Invertebrate

Acute RQ 1127.77 " '

Estuarinemarine Invertebrate Chronic RQ
2038.5 Crop Use

Wlld Rlcc
RQs = EEC NOAEC, whele the ch~on~c EECs foi ~nberteb~ates and fish alethe 21day and the 60-day avelage concentlatlons In su~face water genelated from PRZMIEXAMS fo~ the vallous clop scenario?, ~espectlvely, and chlonlc toxlcltyrefe~ence values are as follows freshwater fish, tathead Ininnom 30-day NOAFC =0 14 pg a I IL. tieshmater lnvertebrates, estnnated chron~c NOAEC =0 00059 pg a I IL. estuarlnel~narlne fish, estnnated cliron~c NOAFC =0 34 pg a I IL. and estuar~~ielmar~ne vertebrates. mqsid ~hr~mp 28-day NOAEC =0 000781 pg a I IL Detalls for all estl~nated chlon~c toxlc~ty talues aleplov~ded ~n

the Ecolog~cal Effects Chatacte~lzatlon sectron "RQs exceed LOCs fo~ chton~c Ilsk (LOC I ) Rice Model Chronic Scenario EECs (ppb)

21 day-1 59 60 daq-0 62 Freshwater Fish Chronic RQ
4.43 Freshwater Invertebrate Chronic RQ
2695 Estuarinernarine Fish Chronic RQ
1.8 "Previous Estimated Environmental Concentrations(EECs) of Zeta-cypermethrin (ppb) in the water column,benthic pore water, and in benthic sediment.

Current Estimated Environmental Concentrations(EECs) ofzeta-cypermethrin (ppb)in the water 60-day 0 0106 0 00104

5 89 0 01 19 0 00161

9 15 0 0641 0 0142

71 9 0 00215 0 000343

1 94

column, benthic

Crop Scenario

FLcucu~nbe~ gound"

FL cucu~nbe~

(I'A cltrus gound "

C A clllus ae~~al '

Wild R~ce " A chosen leptesentatlve scenalto fo~ splay appllcat~ons of zeta-cypenneth~~n to agtlcultu~al clops hchosen leplesentatl\e scenat~o Sol g~anula~ appllcatlons ofzeta-cype~ineth~~n to ~es~dentlal lawns,home pelllnetelq, galdens, and lndusttldl non-agllcultula]areas.

Crop Scenario

CA Gtapes*

GA Peaches "

PA Apples"

F I SUI~ Peak 0 0841 0 00159

9 04 0 201 0 00255

144 146 0 0197

112 0 0405 0 000624

3 53 Media Wdte~ Colu~nn Benth~c PoleWater Benth~c Sed~rnent Watet Column Bcnth~c Pole Wate~ Benth~c Scd~~nent Water Colu~nn Benth~c Pole Wate~ Benth~c Sednnent Wate~ Column Benth~c Pore Wate~ Benthic Sednnent



# " chosen ~eplesentat~ve scenallo foi splay appl~cat~ons of zeta-cypenneth~~n to agt~cultu~al clops 21-day 0 0150 000137

7 79 0 0195 0 00225

12 8 0 122 0 0173

80 3 0 00403 0 000466

2 64

60-day 0 00487 0 000966

5 47 0 0132 0 00170

9 63 0 00206 0 000285

1 62 0 00803 0 001 10

6 28 0 62 pore water, and benthic sediment. 21-day 0 00832 0 00129

7 31 00191 0 00227

12 87 0 00289 0 000384

2 18 0 01 12 0 00149

8 47 1 59 Media Wate~ Colu~nn Benth~c Pole Wate~ Benth~c Sed~tnent Water Column ae~lalVenth~c Pole Watet Benth~c Sedttnent Water Column Benth~c Pole Watet Benth~c Sednnent Wate~ C olu~nn Benth~c Pole Wate~ Benth~c Sednnent Water Colu~nn Peak 0 0883 0 00147

8 35 0 0932 0 00256

14 51 0 0215 0 000414

2 35 0 0838 0 00161

9 14 4 06TABLE OFCONTENTS



### ........................................................................................................................ I

# . Executive Summary 8 A

# . Nature of Chemical Stressor


### ...................................................................................................... 8 B

# . PotentialRisks to Nan-Target Organisms



### ........................................................................... 8 C

# . Conclusions 

## - Exposure Characterization


### .............................................................................. 11



### ................................................................................... D

# . Conclusions 

## - Effects Characterization 13



### .................................................................................................. E

# . Uncertainties and Data Gaps 14 1

# . Environmental Fate


### ................................................................................................................. 14



### ..................................................................................................................... 2

# . Ecological Effects 15



### ................................................................................................................... I1

# . Problem Formulation 15



### ................................................................................................ A

# . Stressor Source and Distribution 15



### ............................................................................................................ 1



# . Source and Intensity 15



### ........................................................... 2

# . PhysicaYChemicaVFate and Transport Properties 16



### ........................................................................ 3

# . Pesticide Type, Class, andMode of Action 17



### ................................................................................................. 4

# . Overview of Pesticide Usage 17



### .................................................................................................................................. B

# . Receptors 18 1

# . Aquatic Effects


### ..................................................................................................................... 19 2

# . Terrestrial Effects


### ................................................................................................................ 19



### ............................................................................................................... 3

# . Ecosystems atRisk 20 C

# . Assessment Endpoints


### ................................................................................................................. 20



### ..................................................................................................................... D

# . Conceptual Model 21



### ................................................................................................................... 1



# . Risk Hypotheses 21 2

# . Diagram


### .................................................................................................................................... 22 E

# . Analysis Plan


### ............................................................................................................................. 26 1

# . Preliminary Identification of Data Gaps andMethods


### .................................................. 26 2

# . Measures to Evaluate Risk Hypotheses and ConceptualModel


### ...................................... 27



# . ..................................................................................................... a Measures of Exposure 27 b

# . Measures of Effect

........................................................................................................... 29 c

# . Measures of Ecosystem and Receptor Characteristics


### .................................................. 30 I11

# . Analysis



### ......................................................................................................................................... 30 A

# . Use Characterization


### ................................................................................................................... 30 B

# . Exposure Characterization


### ......................................................................................................... 33 1

# . Environmental Fate and Transport Characterization


### ......................................................... 33 a

# . Summary


### .............................................................................................................................. 33 b

# . Hydrolysis


### ............................................................................................................................ 33 c

# . Photolysis



### ............................................................................................................................. 34 d

# . Metabolism


### .......................................................................................................................... 34 e

# . SedimentIWater Systems


### .................................................................................................... 35



### ................................................................................................................................ f

# . Mobility 35 g

# . Field Dissipation



### .................................................................................................................. 36 h

# . Bioaccumulation


### .................................................................................................................. 37 i

# . Nomenclature andDegradation Products of Cypermethrin


### .......................................... 37 2

# . Measures of Aquatic Exposure


### ............................................................................................... 37 a

# . Aquatic Exposure Modeling



### ............................................................................................... 37 b

# . Aquatic Exposure Monitoring (Field Data)


### ...................................................................... 41 3

# . Terrestrial Exposure Assessment


### ........................................................................................... 41 a

# . Terrestrial Animal ExposureModeling- Spray Applications


### ......................................... 42

### ..................................... b

# . Terrestrial Animal Exposure Modeling-Granular Applications 44 C

# . Ecological Effects Characterization


### .......................................................................................... 47



### .......................................................................................... 

# . 1 Aquatic Effects Characterization 48



### ............................................................................................................... 

# . a Aquatic Animals 51 i

# . Acute Effects


### ................................................................................................................... 51 ii

# . ChronicEffects


### ............................................................................................................... 53 iii

# . Sub-lethal Effects


### ........................................................................................................ 55



# . .................................................................................................................... iv Field Studies 56



# . ........................................................................................ b Plants Inhabiting Aquatic Areas 56



# . ...................................................................................... 2 Terrestrial Effects Characterization 56



### ............................................................................................................. a

# . Terrestrial Animals 57 i

# . Acute Effects



### ................................................................................................................... 57



### ............................................................................................................... 

# . ii ChronicEffects 58 iii

# . Sub-lethal Effects



### ........................................................................................................ 59 iv

# . Field Studies


### .................................................................................................................... 59



# . ................................................................................................................ b Terrestrial Plants 60 IV

# . Risk Characterization



### .................................................................................................................. 60 A

# . Risk Estimation 

## - Integration of Exposure andEffects Data


### ................................................. 60



# . .............................................................................. 1 Non-Target Aquatic Animals and Plants 60 a

# . Water ColumnExposure 

## - Acute and Chronic Risk


### ..................................................... 61



# . .............................................................. b Sediment Exposure 

## - Acute and Chronic Risk 62



# . ..................................................................................................................... c Aquatic Plants 63 2

# . Non-Target Terrestrial Animals


### ............................................................................................ 63



### ................................................ a

# . SprayApplications: Acute Risk to Birds andMammals 64



### ............................................. b

# . Spray Applications: ChronicRiskto Birds and Mammals 68 c

# . Granular Applications: Acute and Chronic Riskto Birds and


### ....................................... 69 Mammals


### ...................................................................................................................................... 69 

### 3

# . Non-target Plants Inhabiting Terrestrial and Semi-Aquatic Areas


### .................................... 70 

### B

# . Risk Description


### ........................................................................................................................... 70 1

# . Risks to Aquatic Organisms



### .................................................................................................. 71 a

# . Aquatic Animals: Water Column Exposure


### ..................................................................... 72 b

# . Aquatic Animals: Sediment Exposure


### ............................................................................... 73 c

# . Aquatic Plants


### .................................................................................................................... 74 d

# . Summary of Risk to Aquatic Systems


### ............................................................................... 74 2

# . Risks to Terrestrial Organisms



### .............................................................................................. 76 a

# . SprayApplications: Acute and Chronic Risk to Birds andMammals


### ........................... 76 b

# . Granular Applications: Acute and Chronic Risk to Birds andMammals


### ..................... 78 c

# . Non-Target TerrestrialInvertebrates



### ............................................................................... 79 d

# . Terrestrial Plants



### ................................................................................................................ 79 

### 3

# . Review of Incident Data


### .......................................................................................................... 79 a

# . Incidents Involving Aquatic Organisms



### ............................................................................ 80 b

# . Incidents Involving Terrestrial Organisms



### ....................................................................... 80 4

# . Endocrine Effects


### .................................................................................................................. 81 5

# . Threatened and Endangered Species Concerns


### .................................................................... 81 a

# . Action Area



### .......................................................................................................................... 81 b

# . Taxonomic GroupsPotentially atRisk



### ..........................................................................83 i

# . Discussion of Risk Quotients



### .......................................................................................... 84 ii

# . Probit Dose Response Relationship


### ............................................................................... 85c

# . Indirect Effects Analysis


### ..................................................................................................... 87 d

# . CriticalHabitat


### ................................................................................................................... 88 e

# . Co-occurrenceAnalysis

...................................................................................................... 88 C

# . Description of Assumptions. Limitations. Uncertainties. Strengths and Data Gaps



### .............89 1

# . Exposure For All Taxa


### ............................................................................................................ 89 2

# . Exposure For Aquatic Species



### ................................................................................................ 90 3

# . Exposure For Terrestrial Species


### ........................................................................................... 91 a

# . Location of Wildlife Species



### ............................................................................................... 91 b

# . Routes of Exposure


### ............................................................................................................. 91 i

# . Incidental Soil Ingestion Exposure


### ................................................................................ 91 ii

# . Inhalation Exposure


### ....................................................................................................... 92 iii

# . Dermal Exposure


### ........................................................................................................ 92 iv

# . Drinking Water Exposure


### .............................................................................................. 93 c

# . Incidental Pesticide Releases Associated with Use


### ..........................................................93 d

# . Residue Levels Selection


### ..................................................................................................... 93 e

# . Dietary Intake

## - The Differences Between Lab & Field Conditions


### ............................... 93 4

# . Effects Assessment



### ................................................................................................................... 94 a

# . Age Class and Sensitivity of Effects Thresholds



### ............................................................... 95 b

# . Lack of Effects Data forAmphibians and Reptiles


### ......................................................... 95 c

# . Use of theMost Sensitive SpeciesTested



### ........................................................................... 96 5

# . Acute and Chronic LOCs


### ....................................................................................................... 96 V

# . Literature Cited


### ............................................................................................................................... 96 VI

# . Appendices A

# . Environmental Fate and Transport Data 

### B

# . Information About PRZMIEXAMSRun C

# . T-REX Model (Version 1.2.3, August. 2005) D

# . Fugacity Model: Terrestrial Chronic Exposure Estimates for GranularApplications of Zeta- cypermethrin E

# . Ecological Effects Data F

# . TheRisk Quotient Method and Levels of Concern G

# . Equilibrium Partitioning and Concentration in the Sediment 

### H

# . Summary of EndangeredIThreatened Species I

# . Data Requirement Tables -Environmental Fate and Effects andEcological Effects J

# . Incident Reports 

### K

# . Environmental Fate and Monitoring Bibliography And Ecotoxicology Bibliography

### I. Executive Summary A. Nature of Chemical Stressor Zeta-cypermethrin (CAS number 97955-44-7) is a pyrethroid pesticide prepared from the esterification of 3-phenoxybenzaldehyde and 

### 3-(2.2-dichloroviny1)-2,2-dimethylcyclopropanecarboxylic acid. It consists of a mixture of four diastereoisomers, each of which is present as a pair of enantiomers, resulting in eight geometrical and optical isomers. Zeta-cypermethrin is an enriched mixture ofthe (S) alcohol isomers. Different ratios of the eight isomers have resulted in four different cypermethrin products (alpha-, beta-, theta-, and zeta-cypermethrin) all of which have similar environmental fate and toxicological properties. Therefore, for the purposes of this risk assessment, the Agency has allowed use of the cypermethrin TGAI database to fulfill many registration requirements for zeta-cypermethrin and exposure and toxicity data for all cypermethrin products (alpha-, beta-, theta-, and zeta-cypermethrin) have been bridged. Cleavage at the ester moiety of zeta-cypermethrin results in two primary degradation products, 3-(2,2- 

### dichloroetheny1)-2,2-dimethylcyclopropanecarboxylic acid (DCVA) and 3-phenoxybenzaldehyde, which degrades further to 3-phenoxybenzoic acid (3-PBA). Based on the assumption that cleavage ofthe ester bond in theparent compound results in biologically inactive degradates, these compounds should not present a significant risk to non-target organisms and only the parent compound was considered of concern for both aquatic and terrestrial ecosystems. 

### In fact, this assumption is supported by the results of acute toxicity studies in freshwater fish and invertebrates which indicate that the zeta-cypermethrin degradate 3- phenoxy benzoic acid is much less toxic than the parent compound. Like all pyrethroids, zeta-cyper~nethrin is a neural toxin that binds to voltage-gated sodium channels, prolongs the sodium ion penneability during the excitatory phase ofthe action potential, results in spontaneous depolarizations, augmented neurotransmitter secretion rate, and neuromuscular block, and eventually leads to muscle spasms, paralysis, and/or death. Forlnulations for zeta-cypermethrin include an emulsifiable concentrate and a granular. Zeta-cypermethrin is already used to control many pests, including those of cotton, alfalfa, bulb vegetables corn, fruiting vegetables (except cucurbits), legume vegetables, succulent edible-podded peas and beans, rice, sorghum (grain) and millet, soybeans, sugar beets, wheat and triticale crops. Theregistrant is also requesting tolerances or new agricultural uses for the emulsifiable concentrate to include cilantro, head and stem brassica vegetables, leafy vegetables (except brassica), sunflowers,grass forage, fodder, hay group, canola rapeseed, barley, grapes, tree nut group (almond, pecan), berries, peanuts, root and tuber vegetables, cucurbit vegetable group, non-grass feeds (forage, fodder, straw and hay), pome fruits, and stone fruits. Furthermore, a granular zeta-cypermethrin formulation is proposed for use on turf on residential lawns, home perimeters, gardens, and other industrial non-agricultural areas, while a zeta-cyperinethrin emulsion is proposed for use as a termiticide. Zetacypermethrin emulsifiableconcentrate formulations are to be applied as a groundlaerial broadcast foliagelfruit spray while the granular fonnulations are to be applied by ground broadcast equipment to infested areas. B. Potential Risks to Non-Target Organisms This is the Environmental Fate and Effects Division's (EFED) national screening-level ecological risk assessment for the proposed uses of zeta-cypermethrin. Table 1 and Table 2 summarizethe major conclusions and uncertainties ofthis assessment for aquatic and terrestrial receptors, respectively. Functionally, the estimated risks may translate to reduced survival and reproduction of impacted species with subsequent effects at higher levels of biological organization. Based on the toxicity data for all cypermethrin products (alpha-, beta-, theta-, and zeta-cypemethrin), this national screening-level risk 

### 8assessment suggeststhe potential for acuterisk to non-target federally endangered and threatened species (listed) and non-listed freshwater and estuarinetmarine fish (and aquatic-phase amphibians) and invertebratesresulting from both granular and spray applications of zeta-cypermethrin. Overall,risks to aquatic organisms resulting from exposure to granular applications ofzeta-cypennethrin are lower than risks resulting from exposure to spray applications. Based on a comparison of acute LCs"values, invertebrates appear to be the most sensitive aquatic animals, and RQs for invertebrates are much higher than those derived for fish. Theresults also suggest the potential for chronic risk to all aquatic invertebrates (estuarinetmarineand freshwater) and benthic organisms based on modeled national spray and granular applications of zeta-cyperinethrin. For terrestrial organisms, there appearsto be both acute and chronic risk to mammals, but no risk avian species. Specifically, there is the potential for acuterisk to listed and non-listed mammals resulting from zeta-cypermethrin granular applications, while zeta-cypermethrin spray applications result in acute and chronic dose-based RQs for mammals exceeding the acute endangered speciesLOC and the chronic LOC, respectively. Although the Agency does not quantitativelyevaluaterisks to terrestrial invertebrates, a qualitative assessment of toxicitytests on beneficial insects and terrestrial invertebrates indicatesthat zeta-cypermethrin can be classified as highly toxic to non-target beneficial insects and earthworms. Therefore, risks to these taxonornic groups resulting from zeta-cypennethrin granular and sprayapplications cannot be precluded at this time. Risks to aquatic and terrestrial plants were not assessed because toxicity data arenot available; however, based on zeta-cypermethrin's neural toxic mode of action, the Agency doesnot expect zeta-cypennethrin to have phytotoxic effects. In addition, based on the lack of studies demonstrating adverse effects of zetacypermethrin or any other pyrethroid to plants, and the fact that no incident reports have reliably linked zeta-cyper~nethrin or any synthetic pyrethroid to phytotoxic effects despitebeing applied on or near agricultural plants, it appears unlikely that zeta-cypermethrin poses a phytotoxic concern.

7 Table 1. Summary ofenvironmental risk conclusions for aquatic organismsand plantsexposed to nongranularandlor granular zeta-cypermethrin. Assessment Endpoint
Acute Risks to Fish and Aquatic lnvertehrates (Freshwater & Estuarine'Marine) Granular or NonGranular? Non-Granular

Granular Summarized Risk Characterization and Major Uncertainties

The LOC for acute restricted use (L,OC 0.1) is exceeded for all aquatic animals and modeled spray application crop scenarios, except for estuarinelmarine fish under the CA grapes scenario (RQ=0.09). The highest acute RQs are obsec-ved for freshwater inve~tebrates, ranging from 23.33 (CA grapes)to 404.44 (PAapples),greatly exceeding all acute L,OCs. Acute RQ values derived for estuarinelma~ine invertebrates also greatly exceed acute LOCs for spray applications, with RQ values ranging from 17.68 (CAgrapes)to 306.53(PAapples). Because acute toxicity values for frcshwater and estuarine!marine tish are similar in magnitude. the ranges of acute RQs for these taxonornic goups are also similar (0.22to 3.73 for freshwater fish and 0.09 to 1.53for estuarine:marine fish). Overall, RQs to aquatic organisms resulting tiwn exposure to granular applications of zeta-cypennethrin are lower than RQs resulting from exposure to spray applications. For granular applications of zetacypennethrin, the LOC for acute restricted use (LOC 0.I)is exceeded for all aquatic animals, except for estuarinel~narine fish under the FL. turf scenario (RQ =0.04). The acute RQs for freshwater fish, freshwater invertebrates, and estuarine!marine invetteb~ates are 0.10, 1 1.25, and 8.53,respectively.Table 1. Summary of environmentalrisk conclusions for aquatic organisms and plants exposed to nongranular and/or Assessment Endpoint
Chronic Risks to Fish and Aquatic Invertebrates (1:reshwater & EstuarinelMarine)

Acute and Chronic Risks to Benthic Organisms

Risks to Aquatic Vascular and Non-Vascular Plants

Table 2. Summary of environmental risk conclusions for terrestrial organisms and plants exposed to nongranular andlor granular zeta-cypermethrin. Assessment Endpoint
Acute and Ch~on~c Risk to Rnds granuiar Granular or NonGranular? Non-Granular & Granular

Non-Granular

Granular

Non-Granular & Granular zeta-cypermethrin. Summarized Risk Characterization and Major Uncertainties

('hronic RQs derived for aquatic invertebratesare much higher than those deiived for tish, and exceed the chronic L OC' (I)in all instances for both spray and granular applications. For splay and granular applications, chronic RQs exceed the chronic LOC (LOC I) by factors ranging from 5 to 156and fiom 7to 207 for estuarinel~narine and freshwater invertebrates, respectively.The chronic RQs for tish do not exceed the chronic LOC for any ofthc crop scenarios considered in this assessment; RQs range from 0.02 to 0.46 and fi-om<0.0\ to 0.19 for fieshwater and estuarine!inarine fish, respectively. For all aquatic animal species, the highest chronic RQs are observed for the PA apples spray application scenario, and the lowest chronic RQs are observed for the FL turf granular application scenario. IIueto chronic toxicity data gaps for fieshwater invertebrates and estuarinel~narine fish, there is uncertainty regarding the magnitude ofchronic risk esti~nates for these taxonomic groups because RQs are based on estimated chronic toxicity values (detailed description provided in the Ecological Effects Characterization section of the chapter). All acute (RQranges = 2.51to 31.08 and 0.78to 7.78 for sediment and pore water. respectively) and chronic (RQranges = 13.20 to 165.90and 2.38to 40.48 for sediment and pore water, respectively) RQs for benthic organisms exceed the LO('s for acute risk (LOC 0.5),acute restricted use (LOC 0.1), acute endangered species (I.OC 0.05)and chronic risk (LOC I)for all spray application scenarios. For granular applications, all sediment RQs for benthic organisms exceed the LOCs for acuterisk (LOC 0.5).acute restricted use (LOC 0.I),acute endangered species (LOC0.05)and chronic risk (LOC 1)(Acute and chronic RQs =0.98and 4.47,respectively); however, pore water RQs forbenthic organisms only exceed the LOCs for acute restricted use (LOC 0.I),acute endangered species (LOC0.05),and chronic risk (LOC I)(Acuteand chronic RQs = 0.24 and 1.11,respectively!,

_

### -_ _ - - - -_ -_ _ _ _ _ _ _ _ - 

### _ - - - -_ _ - - - _ _ _ - - - -----------------~~~~------~~~~~.~.....---~~~~~~~...

There is uncertainty regarding acute and chronic risk estimates for benthic organisms for the following reasons that are discussed in greater detail in the Ecological Effects and Risk Characterization sections of the assessment: I ) Acute RQs for pore water were derived using a toxicity value estimated with the Equilibrium I'artitioning Theory and the definition ofthe k,v;2)The acute sediment toxicity value (in tenns of whole sediment) used to esti~nate risk and to generate acute pore water and chronic pore water and sediment toxicity values was obtained from a study using a water-sediment system that was not at equilibrium and may underestimate sediment toxicity; and 3)Due to chronic toxicity data gaps for benthic organisms, there is uncertainty regarding the magnitude of chronic risk estimates for this taxonomic group because RQs are based on estimated chronic toxicity values. Toxicity data arenot available to evaluate the risk of zeta-cypennethrin exposure to non-target plants inhabiting aquatic environments; however, EFEII is not concerned about the level ofphytotoxicity ofzetacypennethrin products because its neural toxic mode of action is not expected to be a phytotoxic concern, there are no studies demonstrating adverse effects of zeta-cypamethrin or any other pyrethroid to plants, and no incident reports have reliably linked zeta-cypennethrin or any other compound in the synthetic pyrethroid class of chemicals to phytotoxic effects in algae or aquatic macrophytes.

Granular or NonGranular? Non-Gtanulat

GI

anula~ Summari~ed Risk Characterization and Major Uncertainties

All dose-based (RQs5 0 02 for all crop us scenar~os) and d~etarq-based (RQs5 0 01 for all crop use scenarios) avlan acute RQs atebelow all acute LOCs fo~ spray apphcat~ons ot zeta-cype~meth~ln In add~t~on, all chton~c RQs fo~ bnds are below the LOC fo~ chron~c r~sk (LOC 1)(RQrange= 0 03to 0 63) All acute RQs (~~~,,lft' value<)fo~ ganula~ appl~cat~ons of zeta-cype~~netht~n, arebelow all acute LO( s (RQs i0 08)tor avlan spscles In add~t~on the chronlc avlan RQ IS below the LOC for chron~c r~sk (RQ=0 1) to1 granula~ apphcat~onzC. Conclusions

# - Exposure Characterization Table 2. granular Assessment Endpoint
Acute Risk to Ma~n~nals

Chronic Risk to Mammals

Non-target Beneficial Insectsrre~~est rial lnve~teb~ates

Terrestrial Plants

It appears that zeta-cypermethrin degradation is mainly the product ofmetabolic activity. Aerobic and anaerobic soil metabolism were found to be about 60 and 52-63 days, respectively. In contrast, the rates for aerobic and anaerobic aquatic metabolisrn were 9-10 and 14-17 days, respectively. All abiotic processes appeared to represent relatively insignificant dissipation mechanisms for zeta-cypermethrin. 

### 11 Summary of and/or granular Granular or NonGranular? Non-Granular

Granular

Non-Granular

Granular

Non-Granular & Granular

Non-Granular & Granularenvironmentalrisk conclusions for terrestrial organismsand plants exposed to nonzeta-cypermethrin. Summarized Risk Characterization and Major Uncertainties

For spray applications of zeta-cypennetrhin, no acute dose-based RQs for any size of ma~nmals under any crop scenario exceed the LOC for acute risk (LOC 0.5)or acute restricted use (LOC0.2). However, for 15gand 35g ~nannnals that consume short grass exposed to zeta-cypennethrin via splay applications (RQsrange from 0.05to 0.16 for all sizes of inammals feeding on short pass under all crop use scenarios), dose-based acute RQs exceed the LOCs for acute endangered species (LOC 0.1).None of the RQs for l000g ~nannnals feeding on any dietary item excced any of the acute I.OCs. and all RQs for matn~nals feeding strictly on broadleaf plantsis~nall insects, tall grass, fi.uitslpods~large insects, 01.seeds arebelow the acute LOCs. The acute RQ (LD,~/A~ values) for 15g ~nannnals (RQ=0.83)exceeds all acute LOCs, while the RQ for 35g ~nannnals (RQ=0.44)exceeds the LOC's for acute restricted use (LOC 0.2)and acute endangered species (LOC 0.1).For larger ~nannnals (1000g),the acute RQ (RQ=0.04)is below all acute LOCs. Dieta~y-based chronic RQs for ~namrnals range from 0.02 (mammals feeding on fiuitslpodsllarge insects for zeta-cypennethrin use on barley) to 0.39 (mammalsfeeding on short grass for zeta-cype~methrin use on stone fruits),with no RQs exceeding the chronic LOC (1). Dose-based chronic RQs exceed the LOC for chronic risk (LOC I ) for all modeled crop uses for exposure via short grass; RQs range fiom 0.81 ( 1000g ~nannnals for zeta-cypenneth~in use on barley) to 2.73 ( 15 g ~narnmals for zeta-cypennethrin use stone fruits). For mammals feeding on tall grass, dose-based chronic RQs range from 0.37 ( 1000 gram rnam~nals for zetacypennethrin use on barley) to 1.25 ( 15 gram ~na~n~nals for zeta-cypennethrin use on stone fiuits); chronic RQs exceed the chronic LOC for the stone fruits (RQrange = 0.57to 1.25)and canola (RQrange =0.51 to I.I I ) scenarios, but not for the non-grass animal feeds (RQrange =0.45 to 0.98)or barley scenarios (RQ range =0.37to 0.81). For ~nannnals feeding on broadleafplants~insects. dose-based chronic RQs range from 0.45 ( 1000gram tna~n~nals for zeta-cypc~~nethrin use on barley) to 1.53(15 gram ~nannnalsfor zetacypennethrin use on stone fiuits);chronic RQs exceed the chronic LOC for the stone fixits (RQrange =0.70 to 1.53),canola (RQ range = 0.63to 1.37).and non-grass aniinal feeds (RQrange =0.55 to 1.21)scenarios, but not for the barley scenario (RQrange =0.45to 0.99). All RQs for ma~ntnals feeding on fiuits!pods/large insects and seeds are below the chronic LOC. The chronic RQ for rnam~nals exposed to granular zeta-cypenneth~in is less than the chronic risk LOC (RQ=0.05). In addition, based on a co~nparison of estimated chronic doses for insectivorous ~namnlals and adjusted NOAEIs for three size classes, chronic risk resulting from exposure to granular zeta-cypennethrin appears unlikely (RQrange=0. 19to 0.41). -- --------- -------- ...................................................................... For chronic risk to ~nam~nals, it is unclear whether other routes of granular zeta-cypermethrin exposure or combined routes of exposure (i.e.,direct consumption of granules, ingestionof granules that adhere to soil inve~tebrates. partitioning of dissolvedzeta-cypa~nethrin to on-site sources of wildlife drinking water, and dermal exposure of granules released to sutx-oundingsoil and on-site puddles) would result in chronic risk concelns for terrestrialreceptors. Although EFEII does not quantitativelyestimate risk to non-targetterrestrial invertebrates, this hazard assesslnent shows that zeta-cypennethrin exposure can he expected to result in acute toxicity to honey bees and is considered to be highly toxic on both a contact (LDS0 = 0.023ug a.i./bee)and an oral basis (LD5,, = 0.172 ug a.i.ihee).In addition. results of an acute study with eatthwonns yielded a 48-hour contact 12C'5,~ value of 26.09 ug a.i.lctn2for cypennethrin applied to filter paper, categorizing zeta-cype~methrin as vely toxic to earthwo~lns.Based on the data available at this time, acute and chronic toxic effects to non-target insects and terrestrial inve~tebrates resulting htn the proposed zeta-cypel-inethrin uses cannot be precluded and risk is presumed. Toxicity data are not available to evaluate the risk of zeta-cypennethrin exposure to non-target te~vestrial plants; however, EFED is not concerned about the level ofphytotoxicity of zeta-cypennethrin products because its neural toxic mode of action is not expected to be a phytotoxicconceln, there areno studies demonstrating adverse effects ofzeta-cypennethrin or any other pyethmid to plants, and no incident repo~ts have reliably linked zeta-cypermethrin or any other co~npound in the synthetic pyrethroid class of chernicals to phytotoxic effects non-targette~vestrial plants.Zeta-cypermethrin appears to be stableto hydrolysis (except in alkaline media at pH 9, tlh-2 days) and in the presence of light. Photolysis in water was 36 days and on soil, 128-215days (dark control corrected). Thebasic mechanism of degradation of zeta-cypermethrin is cleavage at the ester moiety, which results in twoprimary degradation products, 

### 3-(2,2-dichloroetheny1)-2,2-dimethylcyclopropane carboxylic acid (trans-DCVA, maximum. 79% in pH 9 solution, and 34% in anaerobic aquatic ~netabolism study) and 3- phenoxybenzaldehyde, which is further oxidized to 3-phenoxybenzoic acid (3-PBA, maximum 35% in aqueousphotolysis study). Another degradation product was cyperamide. Thisproduct keeps a similar structure to that of the parent; however, it was observed only in one laboratory study, the soil photolysis study, at a maximum of 13.3%,which approaches the limit that EFED generally considers of concern (10% ofthe applied). Zeta-cypermethrin is not likely to leach to ground water, as shown by an adsorptionldesorptionbatch equilibrium study (Koc =20,800 

### - 328,500 LIKg) and an aged leaching study. Zeta-cypermethrin shows a relatively low potential for volatilization from moist soils and water (vapor pressure 2.5x10-hm~~ and Henry's Law constant 3.4~10.' ~tm-m3/mol; relatively low solubility

### in water 0.0040 tngIL, and high soillwater partitioning). When zeta-cypennethrin is applied to the field, due to the relatively low mobility of the chemical, it is expected to reach adjacent bodies of water via spray drift or through runoff events accompanied by erosion. Once there, zeta-cypermethrin may be expected to remain adsorbed to suspended solids or organic matter in the water colu~nn, or partition with the sediment phase, where it could persist (the aerobic and anaerobic aquatic tnetabolism studies for zeta-cypennethrin indicate that the chemical is not persistent; however, field studies conducted on rice, with zeta-cypennethrin, show high persistence in aquatic environments). If zeta-cypermethrin is applied repeatedly, it is possible that the chemical may accumulate in the sediment in ever larger amounts, with slow biodegradation. Generally zeta-cypermethrin is not expected to leach substantially into groundwaters. Zeta-cypennethrin shows a moderate potential to bioaccumulate in fish,with maximum BCF of468 for whole fish in a 28 day study. Depuration appeared to be moderate, with near 10-15% of the initial residues remaining after 2 1days. Theuncertainties related to the fate database arerelated to the difference observed between the laboratory aquatic metabolism studies, which predict short half-lives, while the supplemental aquatic field dissipation studies showed longer term half-lives. Estimated environmental concentrations (EECs) for zeta-cypermethrin calculated using the Tier 2 PRZMIEXAMS aquatic models and employing tnaxi~numapplication rates, indicate that zetacypermethrin preferentially partitions to the sediment compartment in model water bodies. Four crop usage scenarios,which represent worst case scenarios, were considered: apples,peaches, turf, and grapes. Ecological exposure can occur through several pathways. Terrestrial and avian speciesmay inadvertently be exposed to cypennethrin as a result of its direct application to crops (both dermal and inhalation pathways are possible). Ingestion of food and drinking water contaminated with zeta-cypermethrin are also possible exposure pathways. Spraydrift from the target area as well as runoff and erosion of zetacypermethrin to soils can result in exposure to aquatic organisms. To estimate exposure of terrestrial animals, terrestrial EECs were generated using the Tier 1 model T-REX (T-REX, Version 1.2.3, dated August 8, 2005) for spray applications based on maximum application rates and use patterns. For foliar spray applications, EECs and acute and chronic RQs were estimated for residues on various forage categories (short grass, tall grass, broadleaf plants/small insects, fruitslpods/large insects, and seeds) for four representative crop uses: stone fruits, canola, non-grass animal feeds, andbarley.For granular applications, acute exposure and risks were estimated with the conceptual approach using the ~~~"lft' method given in the Tier 1 model T-REX. Terrestrial EECs were calculated based on an estimation of loadings of pesticide per unit area (expressed in terms of mg a.i./ft2),assuming that 100%of the application was present on the surface ofthe soil. Estimates for chronic exposure of terrestrial wildlife to granular zeta-cypermethrin in this risk assessment were based only on direct ingestion of soil invertebrates that havebio-concentrated zeta-cyperinethrin residues of granules in soil. This estimation of earthworm concentration was calculated using a hgacitybased (equilibrium partitioning) approach based on the work of Trapp and McFarlane (1995) and Mackay and Paterson (1981). D. Conclusions 

### - Effects Characterization Based on theresults of acute toxicity studies with all cypennethrin products (alpha-, beta-, theta-, and zetacypennethrin), zeta-cypennethrin can be classified as very highly toxic on an acutebasis to freshwater fish, freshwater invertebrates (e.g. daphnids, midge, amphipods, and gastropods), estuarinelmarine fish, and estuarinelmarine invertebrates (e.g. shrimp and crustaceans). In addition, zeta-cypermethrin can be categorized ashighly toxic to oysters. Acute toxicity studies on the cypermethrin degradate 3- phenoxybenzoic acid in freshwater fish and invertebrates show that the degradate is much less toxic than cypermethrin TGAI. The lowest acute LCSo values reported for freshwater fish and estuarinelrnarine fish range from 0.39 pg a.i.1Lin rainbow trout to 0.95 pg a.i.lL in sheepshead minnow, whereas the lowest acute LC50values for freshwater and estuarinelmarine invertebrates are approximately two orders of magnitude less and range from 0.0036 pg a.i./L in amphipods to 0.00475 pg a.i./L in mysids; thus, invertebrates are expected to be at a greatest risk for acute effects (lethality). The LCSo values for benthic organisms based on exposure to cyperinethrin in bulk sediment and pore water were 3.6 pg a.i.1kg sediment and 0.00257 pg a.i./L, respectively.


### In addition to lethality data, several acutetoxicity studies provide information regarding sub-lethal effects of cypermethrin. For fish, sub-lethal effects include rapid and erratic swimming, partiallcomplete loss of equilibrium,jaw spasms, gulpingrespiration, lethargy, and darkened pigmentation. 

### In aquatic invertebrates, sub-lethal effects include lethargy, erratic swimming behavior, loss of equilibrium, surfacing, immobilization, and decreased movement in response to stimulation. In most studies, the acute NOAEC values for sub-lethal effects are approxiinately 2- to 3-fold lower than the corresponding LC50 values, indicating that sub-lethal effects can occur at exposure levels below the concentrations that cause lethality. Chronic toxicity studies with cyperinethrin are available for freshwater fish and estuarinelmarine invertebrates. Results of these studies suggest that zeta-cypermethrin can be expected to adversely affect neonate survival of freshwater fish (NOAEC =0.14 pg a.i.lL) and reproduction and growth of estuarinelmarine invertebrates (NOAEC= 0.781 ng ai1L). Currently, there are no data available on the chronic effects of zeta-cypennethrin or any other cypermethrin product on benthic organisms, estuarinelmarine fish, or freshwater invertebrates. However, estimates of chronic toxicity to benthic organisms (NOAECs =0.59 ug ailkg sediment and 0.0042 pg a.i./Lpore water), estuarinelrnarine fish (NOAEC =0.34pg a.i./L), and freshwater invertebrates (NOAEC =0.00059 pg a.i.1L) were derived to estimate risk using the methodology described in the Ecological Effects Characterization section ofthe assessment.Results of acute toxicity studies on birds suggest that zeta-cypermethrin can be classified aspractically non-toxic to slightly toxic to avian species (LDSo >2,000 mg a.i./kg body weight LCj0> 2,634 ing a.i.1kg diet), moderately toxic to mammalian species (LDSo = 86 mglkg body weight ), highly toxic to honey bees on both an acute contact (LDSo =0.023pg a.i./bee) and acute oral basis (LD50=0.172 pg a.i./bee), and very toxic to earthworms (LCSO = 26.09pg/cm2)on an acute contact basis. Avian reproduction studies showed no adverse effects at 50 ing a.i./kg diet (the highest concentration tested), while the NOAEC value of 100mg a.i./kg diet (5 mg a.i./kg/day) was established for mammals based on decreased body weight and body weight gain in adults and offspring in the available 2- and 3- generation reproduction studies with rats. Currently, there are no data available regarding the effects of zeta-cypermethrin degradates to any terrestrial organism or the effects of zeta-cypermethrin to terrestrial or aquatic vascular and non-vascular plants. E. Uncertainties andData Gaps 1. Environmental Fate The environmental fate database for zeta-cypermethrin is considered to be complete. However, monitoring data specific for zeta-cvpermethrin in U.S. groundwater, drinking water, surface water, and sediment were not identified in searches of the National Drinking Water Contaminant Occurrence Database (NCOD), National Water Quality Assessment Program (NAWQA), or the Storage and Retrieval (STORET) database. Estimations regarding the spray drift fraction in the PRZMIEXAMS model runs were based upon the Tier 

### I mode of AgDRIFTBprogram. Theprimary assumption is that the wind speeds at each site are generally below 10tnph. This is consistent with the label language that indicates "Make aerial or ground applications when the wind velocity favors on target product deposition (approximately 3 to 10mph). Do not apply when wind velocity exceeds 15mph." However, there may be uncertainty with respect to unconcerned applicatorsthat would apply the chemical at wind speeds above 10mph. There is uncertainty with respect to the level of mitigation that a buffer zone of 150ft plus a vegetative strip of 10ft can provide. The estimation of spray drift was obtained from AgDRIFTB; however, there is no way to know how well the buffer zone will protect the bodies of water from runoff. In certain cases, the level of runoff is the most important factor, rather than the level of spraydrift. This is an assumption made in the Tier I calculation of AgDRIFTO. Cypermethrin is an enhanced mixture of four diastereoisomers, each of which ispresent as a pair of enantiomers, resulting in eight isomers. Different ratios ofthe eight isomers have resulted in four different cypermethrin products (alpha-, beta-, theta-, and zeta-cypermethrin) all of which have similar environmental fateproperties. The cis:trans ratio of zeta-cypermethrin isomers was found to vary in different toxicity tests (e.g., 48.8:42.7, 55:45,53.6:46.4,54:46). However the cis:trans ratio is close to a 5050ratio suggesting that toxicity profiles should be accurate. The label for Fury and Mustang Insecticide specify cisltrans ratio: maximum 55% (k)cis and minimum 45% (i) trans. An enhanced zetacypermethrin [(S)alcohol enriched] has an equivalent toxicity profile to the cypermethrin enantioineric mixture but is more efficacious (half the application rate of the enantiomeric mixture). The maximuin rate of application for the emulsifiable concentrate to crops is 0.05 lb a.i.1A with a maximum of 6 applicationslseason and a minimum interval of 7 days between applications (a total 

### 14maximuin seasonal application rate of 

### 0.3 lbs a.i./A). However, for this risk assessment 

### EFED assumed that zeta-cyperinethrin was applied at a inaxiinuln of 

### 6 times per year. If there are conditions under which there is more than one growing season for a crop within a single year, exposure estimates and risk to aquatic and terrestrial organisms could be significantly underestimated. Examples of crops that have multiple seasons where this may be a concern include leafy, brassica, and fruiting vegetables in CA, AZ, FL, GA,LA, NC, TX, andlor SC. It is assumed for pesticides which have residential outdoor uses (applications to home lawns, gardens, parks, etc.) that runoff water from rain and/or lawn watering may remove pesticide to storm sewers and then directly to surface water. However, in general, outdoor residential uses are comprised of multiple, relatively small, temporally and spatially variable applications that are not simulated in agricultural models. Therefore, there is some uncertainty 

### in the aquatic exposure assessment because a model specifically aimed at simulating pesticide fate and transport in a complex urban landscape has not yet been developed to generate exposure estimates strictly for urban areas. Furthermore, the Agency does not have a method to obtain EECs for termiticide uses in urban areas as well. However, EFED believes that the exposure due to this particular use (subterranean) would be ininimal and that both surface and ground waters are not at a high risk. Zeta-cypermethrin is likely to bind strongly to soils, and although it is unlikely that the use will result in substantial exposure, there is uncertainty. In addition, the likelihood of significant exposure from the use of zeta-cypermethrin as a barrier treatment is also uncertain. 2. Ecological Effects The screening level risk assessment for zeta-cypennethrin has been conducted despiteunfulfilled guideline requirements and existing data gaps. Table 1-2 (Appendix

### I) lists the status of the ecological effects data requirements for zeta-cypermethrin. The following is a brief synopsis ofthe major ecological effects data gaps and uncertainties. There is uncertainty surrounding estimates of chronic toxicity to freshwater invertebrates, estuarinelmarine fish, and benthic organisms, because no data are currently available. To assess risk to these taxonomic groups, RQswerebased on chronic NOAEC values derived using acute-to-chronic ratios. The available acute toxicity study for benthic organisms was not conducted with the exposure system at equilibrium. Sincethe chronic RQ for sediment and acute and chronic RQs for pore water were derived from the sediment toxicity value, uncertainty is introduced to all categories ofthe risk assessment for benthic organisms. Acute and chronic sediment studies have been recently submitted by the pyrethroid working group (PWG) but were not reviewed in time for inclusion in this assessment. 11. Problem Formulation A. Stressor Source and Distribution 1. Source and Intensity This assessment considers only the current proposed uses of zeta-cypermethrin; for use on agricultural crops and turf on residential lawns, home perimeters, gardens, and other industrial non-agricultural areas for the control of certain insect pests and termites. Thevarious formulations can be applied viagroundlaerial broadcast foliagelfruit spray or by ground broadcast treatment of infested areas using granular formulations. Themajor degradation products of zeta-cypermethrin in the environment are cis- and trans-DCVA, 3-PBA, and 3-phenoxybenzaldehyde. However the available toxicity data suggest that degradates should not be considered asmajor stressor sources because of efficacious inactivity ofthe parent compound after the ester bond has been cleaved. For the purposes of this risk assessment, only the parent compound is considered an important stressor. Terrestrial exposure to the parent compound is based on direct spray application on food items including short grass, tall grass, seeds, and broadleaf plants and insects resulting from applications of zetacypermethrin at the maxiinurn label rates. Exposure to aquatic organisms is theresult ofrunofflerosion and spray drift from labeled applications and is functionally the amount of compound in the water that would directly contact organisms.Themaximumrate of spray application to crops is0.05 lb a.i.1A with a maximum of 6 applications/season and a minimum interval of 7 days between applications. Themaximum use scenario of granular zeta-cypermethrin is a single application at the inaximuln rate of 0.225 lb a.i.lAlyear. The magnitude of exposure estimates are largely dependent on the biology of the receptor (e.g., food consumption rate), the use patterns and environmental fate and transport, which are further explored later in this document. 2. PhysicaWChemicaVFateand Transport Properties Cypermethrin 

### ((RS)-a-cyano-3-phenoxybenzyl (IRS,3RS;1 

### RS,3SR)-3-(2,2-dichloroviny1)-2,2- dimethylcyclopropanecarboxylate) is a mixture of four diastereoisomers, each of which ispresent as a pair of enantiomers, resulting in eight isomers. It is prepared by the esterification of 3-phenoxybenzaldehyde and 

### 3-(2,2-dichloroviny1)-2,2-dimethylcyclopropane carboxylic acid. Different ratios of the eight isomers have resulted in four different cypermethrin products (alpha-, beta-, theta-, and zeta-cypermethrin) all of which have similar environmental fate properties. Zeta-cypermethrin is an enhanced mixture of (S) alcohol isomers. For the purposes of this risk assessment, the Agency has allowed use of the cypermethrin TGAI database to fulfillmany registration requirements for zeta-cypermethrin and exposure data for all cypennethrin products (alpha-,beta-, theta-, and zeta-cypermethrin) have been bridged. The two isomeric mixtures are expected to behave similarly in the environment. Zeta-cypermethrin is expected to have little mobility in soil surfaces (Koc>20,800 LIKg) and leaching into groundwater is not expected to be an important transport process. Volatilization is not expected to be an important transport process neither, since zetacypermethrin has a relatively low vapor pressure and Henry's Law constant (refer to Table 

### 3). Zetacypermethrin is moderately persistent in the environment and degrades through a combination of biotic and abiotic mechanisms. Zeta-cypermethrin is relatively stable to hydrolysis at acidic and neutral pH levels, but degrades in a few days under alkaline conditions (pH 

### 9, t :/, 

# -2 days). Zeta-cypennethrin is relatively light stable, but still undergoes photolysis in water, with half-lives of about a month or more in distilled water. Therate ofphotolysis appearsto be enhanced in natural waters (which contain photosensitizing agents like hu~nic and fulvic acids), where the accelerated degradation results in half-lives of a few days. Zeta-cypennethrin photodegrades on soil with a dark control corrected half-lives of1128 days. Under both aerobic and anaerobic soil conditions, zeta-cypermethrin biodegrades relatively slowly in soils, with halflives on the order of about 

### 2 months. In contrast, under aerobic and anaerobic aquatic metabolism conditions, the degradation rate is enhanced, with half-lives of around 9 to 17days. If released to water, zeta-cypermethrin partitions to sediment and may degrade slowly. Degradates observed in laboratory studies result from cleavage at the ester moiety of zeta-cypermethrin, which formed 3-(2,2-dichloro-

### etheny1)-2,2-dimethylcyclopropane carboxylic acid (cis- and trans-DCVA, maximum 79% in pH 9 solution, and 34%in anaerobic aquatic metabolism study) and 3-phenoxybenzaldehyde (maximum 

### 65% in pH 9 solution). The latter one is further oxidized to 3-phenoxybenzoic acid (3-PBA, maximum 35%in aqueousphotolysis study). Another product observed in the soil photolysis study only, was cyperamide (maximum 13.3%). Themain chemical and physical properties of zeta-cypermethrin are summarized in Table 3.

3. Pesticide Type, Class, and Mode ofAction

Table 3. Physical and chemical properties ofzeta-cypermethrin

# .

The pyrethroids (includingzeta-cwennethrin) share similar modes of action, and are considered axonic poisons that affect both the peripheral and central nervous system. It is now well established that severe neurological symptomsofpoisoning with pyrethroids in mammals and insects are the result of modification of Na' channel activity (cellular pores through which sodium ions arepermitted to enter the axon to cause excitation) (Matsumura,l985). Advanced electrophysiological experiments using a voltage clamp and a patch clamp, together with ligand-binding and ionic flux experiments, have unveiled unique actions ofpyrethroids of keeping the Na' channel in the open state for an extremely long period, sometimes as long as several seconds. This modification of ~a' channel properties leads to hyperactivity of the nervous system. This action leads to spontaneousdepolarizations, augmented neurotransmitter secretion rate and neuro~nuscular block, which ultimately results in paralysis ofthe insect. Pyrethroids have also been shown to suppress GABA and glutamate receptor-channel complexes and voltage-activated Ca "channels, but the toxicological significance ofthese actions is uncertain. Relative to physiological responses, researchers have designated two types of pyrethroids, Type 

### I (e.g., pyrethrins, S-bioallethrin, resmethrin, permethrin) and Type I1 (e.g.,cypennethrin, deltamethrin, fenvalerate). Zeta-cypermethrin is classified as a type 11 synthetic pyrethroid, with a cyano group at the a-carbon position ofthe alcohol moiety, and is considered a third generation pyrethroid, that is, more light- stable and persistent in the environment than early pyrethroids like allethrin, phenothrin (also commonlyknown as sumithrin) and resinethrin. Zeta-cypermethrin has three optically active centers and is composed of 

### 8 isomers, and like all pyrethroids, is a contact poison that can quickly penetrate thenervous system and have an effective "knockdown" action (induction oftemporaryparalysis) for most flying insects. Reference Laskowsk~ (2002) Property Molecula~ we~ght

4. Overview of Pesticide Usage Value 416 3 SMll FS notallon C AS numbel

Wate~ solub~l~ty Meltlng polnt Bolllng polnt Vapor plessure log K,,, Henty's Law constant CIC(CI)=C'CI C(C)(C)CIC'(=O)OC(C#N)c2cccc(Oc3ccccc3)c2 97955-44-7 (52315-07-8 fol zeta-cype~inethnn)

4 0x10' mg/~ 78-81 "C 200 "C at 9 3 Pa (0070 mm lig) 2 SXIO'I~I~H~ 6 54 3 4x 10

### '~tm-~n'l~nol 11111) \\\\\\ Lh~~~~~r~clt~\~~\ < <*111 LII~*IIII&J 01<)5')11~1111 Laskowsk~ (2002) To~nl~n 1994 roml~n 1994 Iaskowsk~ (2002) Laskowsk~ (2002) Laskowsk~ (2002)Zeta-cypermethrin is an insecticide already registered for use on a number of agricultural crops (including cotton and rice); however, this assessment focuses on the registrant's proposed uses and requested tolerances for cilantro, head and stem brassica vegetables, leafy vegetables (except brassica), sunflowers, grass forage, fodder, hay group, canola rapeseed, barley, grapes, tree nut group (almond, pecan), berries, peanuts, root and tuber vegetables, cucurbit vegetable group, non-grass feeds (forage, fodder, straw and hay), pome fruits, stonefruits. Zeta-cypermethrin is also proposed for use on turf and as a termiticide (see Use Characterization section of the assessment for additional detail). Zeta-cypermethrin formulations proposed for use include emulsifiable concentrates (for agricultural spray applications), granular formulations (for use on turf on residential lawns, home perimeters, gardens, and other industrial nonagricultural areas), and emulsion fonnulations (for use as a termiticide). B. Receptors Each assessment endpoint requires one or more measures ofecological effect, which are defined as changes in the attributes of an assessment endpoint itself or changes in a surrogate entity or attribute in response to exposure to a pesticide. Ecological measures of effect for this screening level risk assessment arebased on a suite ofregistrant-submitted toxicity studies performed on a limited number of organisms in broad groupings. Table4 gives examples of taxonomic groups and test species evaluated for ecological effects in this screening level risk assessment. Within each of these very broad taxonomic groups, an acute andlor chronic endpoint is selected from the available test data. A complete discussion of all toxicity data available for this risk assessment and the resulting measures of effect selected for each taxonomic group are included in Appendix 

### E. It should be noted that zeta-cypermethrin is a modified form of cypermethrin, and a comparison oftheir respective databases (although it is limited for zeta-cypennethrin) indicates that they have similar toxicity to non-target organisms. Therefore, the Agency assumes equivalent toxicity and has allowed use of the cyperinethrin TGAI databaseto fulfill many registration requirements for zeta-cypermethrin; toxicity data for all cyperlnethrin products (alpha-,beta-, theta-, and zeta-cypennethrin) are being bridged for risk assessment purposes.

Table 4. Taxonomic groups and test species evaluated for ecological effectsin this screening-level risk assessment for zeta-cypermethrin. Taxonomic group

Birds " Mammals
Benficial Insects / Terrestrial 1nvertebl.ates

Freshwater Fish Example(s) of representative species Mallard duck (AntrspItr@~h.vnchos) Bobwhitc quail (Colin~rs lmirginiatltr~) Laborato~y rat (Rattwnorvegiclis) Honey bee (.?pisntellifiro) Earthwo~rn (Ei.~etiia.fetida) Bluegill sunfish (L.e~?on~i.~ nzcrcrochir~u) Rainbow trout (Oncorh.vncA~rs n~-vkiss) Fathead minnow (Pintephnles promelns)1. Aquatic Effects Table 4. Taxonomic groups and test species evaluated for ecological effectsin this screening-level risk assessment for zeta-cypermethrin.

For aquatic effects, registrant-submitted studies on cypermethrin technical grade active ingredient 

### (TGAI) are available for acute and chronic exposure of freshwater fish, acute exposure of freshwater invertebrates, acute exposure of estuarineharinefish, and acute and chronic exposure of estuarinelmarine invertebrates. Additional ecological effects data are available fromregistrant-submitted studies of acute cypermethrin exposure to benthic organisms. No scientifically valid studies on zeta-cypermethrin TGAI were submitted by the registrant for chronic exposure of freshwater invertebrates or estuarinelmarine fish. No toxicity studies on zeta-cypermethrin were submitted for algae or aquatic macrophytes. Taxonomic group

FI-eshwaterInvertebrates'
Benthic Organisms '
Estuarinelmarine Fish

I:stuarine!~narine Invertebrates
" Birds represent sunogates for reptiles and te~rest~ial phase amphibians.



### In addition to studies on the parent compound, ecological effects data for the zeta-cyperinethrin degradate 3-phenoxybenzoic acid are available for freshwater fish and invertebrates Example(s) of representative species Water flea (Dcrphrtinntagno) Crayfish (Oronecte.~ sp.) Maytly larvae (Enelisrltodarli) Maytly la~-vae(Cloeon dipteruni) Whirligig(Gvrinwnatritor ) Backswi~nrner (Notonectnsp.) Waterboatman (Corixaptlttctota) Water mite (Pionaccfutca) Amphipod (Ganinicrr11.~ pulc,.~) Midge (C'ltir-o~~omtr.~ thlrninli) lsopod (A.~cllrrs .spp) Gastropod (L.vnittea peregrtr) Midge (Cltaoborirssp.) Midge (C'hirortontirs riparil~s) Midge (Cltironornt~s trntarts) Amphipod (/<i,alella azteca) Sheepshead tninnow (C:vprinodort~~crriegatrts) Atlantic salmon (Scrlnroscrlar) Eastern oyster (Gassostrcarirgi~~ica) Mysid shrimp (MlsidopsisBohia) Pink shrimp (Penaetlsiflrorarlrm) Shrimp (C.septem.~pirtosn) Lobster (tjomartunrnerircrn~ls) I'acific oyster (Crassosrreogigos) Fiddler crab (Uca plcgilrrtor)

2. Terrestrial Effects " Freshwater tish may be surrogates for aquatic phase amphibians. "Only studies that exposed benthic organisms via water-sediment systems were used to evaluate potential risk to benthic organisms; all other studiesthat exposed benthic organisms via water-only systems werc used to evaluate risk to water colu~nn dwelling organisms.

For terrestrial effects, registrant-submitted studies on cyperinethrin TGAI are available for acute, subacute, and chronic exposureto birds, and acute and chronic exposure to mammals. Additional ecological effects data for cyperinethrin are available for honey bees (Apismellife~*u) and earthworms (Eisenia,fetida); results of these studies havebeen incorporated into the risk characterization as an additional line of evidence. No toxicity studies on zeta-cypermethrin were submitted for plants inhabiting terrestrial areas.Toxicity data ofterrestrial organismsto zeta-cypennethrin degradates were not submitted. 

### 3. Ecosystems at Risk 

### The ecosystemsthat could be potentially at risk from drift and runoff of zeta-cypennethrin include freshwater, estuarineharine,and terrestrial ecosystems. Zeta-cyperlnethrin can be applied directlyto terrestrial habitats as a spray or as granules. The spray application is limited to agricultural settings; however, the granular forlnulationsand the emulsion formulations for termiticide use can be used in residential and other non-crop areas. Given the number and nature of uses of zeta-cypermethrin (proposed and already registered), the area ofthe United Statesthat could be potentially exposed to the chemical is expansive (virtuallyeverywhere). Due to zeta-cypermethrin's potential use across the United States as an insecticide and the nature of its application in both agricultural (spray) and residential settings (granular), it may be introduced to a more diverse array of ecosystems than are typically exposed to other pesticides that are applied primarily around agricultural areas. From these terrestrial ecosystems the chemical is expected to be transported to aquatic ecosystems via spray drift and/or runoff/erosion. Given zeta-cypermethrin's low solubility and affinity for binding to organic carbon and particulate matter, the bio-availability of the chemical in the water colu~nn may be limited after 24 to 48 hours. Therefore, while there ispotential for acuterisk to organisms living in this media within an aquatic ecosystem, chances of chronic exposure and risk to organisms strictly residing there is much lower. However, because zeta-cypermethrin is expected to quicklyprecipitate out ofthe water column, settle on thebenthos, bind to the sediment, and persist for extended periods of time, the anticipated nature of the exposure in the benthos mayresult 

### in significant potential for acute and chronic risk to organisms living in this compartment of the aquatic ecosystem. Ecosystems potentially at risk reflect a potential concern by the Agency and can be expressed in terms of the selected assessment endpoints. The typical assessment endpoints for screening-level pesticide ecological risk assessments arereduced survival, and reproductive and growth impairment for both aquatic and terrestrial animal species. Potential effects on a set of surrogate species areused to extrapolaterisk to all species. For both aquatic and terrestrial animal species, direct acute and direct chronic effects are considered. Although these endpoints are measured at the individual level, they provide insight about risks at higher levels of biological organization (e.g.populations and communities). For example, pesticide effects on individual survivorship have important i~nplications for both population rates of increase and habitat carrying capacity. Indirect effects and effects on critical habitat are only considered in therisk characterization for potential effects on endangered species. C. Assessment Endpoints Thisrisk assessment considers the maximum application rates of zeta-cypermethrin on vulnerable soils as reported on the label, the maximum numbers of applications, and the minimum application intervals as reported by theregistrant to estimate exposure concentrations as a result of the proposed uses of zetacypennethrin. This assessment is not intended to represent a site or time-specific analysis. Instead, this assessment is intended to represent high-end exPosures at a national level. Likewise, the most sensitive toxicity endpoints are used from surrogate test species to estimate treatment-related direct effects on acute mortality and chronic reproductive, growth and survival assessment endpoints. The ecological relevance of selecting the above-mentioned assessment endpoints is as follows: 1) complete exposurepathways exist for these receptors; 2)thereceptors may be potentially sensitive to pesticides in affected media and in residues on plants, seeds, and insects; and 3) the receptors could potentially inhabit areas where pesticides are applied, or areas where runoff and/or spray drift may impact the sites because suitable habitat isavailable. These endpoints are meant to reflect population sustainability and ecosystem biodiversity, and are standard assessment endpoints that are considered for the majority of pesticides with agricultural uses. Specifically, this assessinent addresses assessment endpointsfor birds, mammals, reptiles, amphibians, beneficial insectslterrestrial invertebrates, fish, aquatic invertebrates, and benthic organisms. Although data on direct toxicity to reptiles and amphibians are not required aspart ofthe standard dataset submitted to the Agency for pesticide registration and arenot currently available for zeta-cypennethrin, toxicity and risks to reptiles arebased on surrogatedata from studies with avian species. For amphibians, freshwater fish are considered a suitable surrogate for the aquatic life-stage and birds a suitable surrogate for the terrestrial life-stage. The toxicity studies are used to evaluate the potential of zeta-cypermethrin to cause adverse effects, to detennine whether further testing is required, and to determine the need for precautionary label statements to minimize thepotential adverse effects to non-target animals and plants (40

### CFR 

### 3 158.202,2002). A summary of the assessment endpoints and measures of effects selected to characterize potential ecological risks associated with exposure to zeta-cypennethrin is provided in Table 5.

Table 5. Summary of assessment and measures of effect for zeta-cypermethrin. Assessment Endpoint Measure of Effect la. Bobwhite quail and mallard duck acute 01x1LD~II. I. Abundance (i.e.,survival, reproduction, and growth) of Ib. Bobwhite quail and mallardduck subacute dietary LCsII. individuals and populations ofbirds. Ic. Bobwhite quail and mallard duck chronic reproduction >NOAEC. 2a, laboratotyrat acute oral LD5(,. 2. Abundance (i.e.,survival, reproduction, and growth) of 2b. laboratotyrat 2- and 3-generation reproduction chronic NOAEC individuals and populations of maintnals. and LOAEC'. 3a. Rainbow trout and bluegill suntish acute LC;O(guidelinerecommended species). Acute LCrll in several other species of freshwater tish 3b. Fathead minnow chronic (early-life) NOAEC and LOAEC. 3c. Water flea acute LCsll and ECill (guideline-recommended species). 3. Survival and reproduction of individuals and cotnmunities of Acute LC5,, and EC5,, in several other species of freshwater freshwater fish and invertebrates. invertebrates. 4a. Sheepshead minnow acute LCIO. 4b. Eastern oyster and mysid shrimp acute I.Cill and EGO(guidelinerecommended species). Acute LCil,and ECiO in several other species 4. Sut-vivaland reproduction of individuals and communities of of estuarineimarine invertebrates. ctustaceans. and molluscs. estuarinelmarine fish and invertebrates. 4c. Mysid shrimp chronic NOAEC and LOAEC. 5. Survival of individuals and communities of freshwater benthic 5a. Midge and amphipod acute LCqII. organisms. 6. Survival ofterrestrial invertebrate populations (beneficial insects 6a. I-Ioneybee acute contact l.D51,. and ea~thwonns). 6b. Ea~thwonn acute contact LCill I.Ui,, = Lethal dose to 50% ofthe test population. LC'~I~(ECiIl) = Lethal (effective)concentration to 50% of the test population. NOAEC = No-observed-adverse-effect concentration. IDAEC = 1-owest-observed-adverse-effect concenhation. D. Conceptual Model 1. Risk Hypotheses Risk hypotheses are specific assumptions about potential adverse effects (i.e., changes in assessmentendpoints) and may bebased on theory and logic, empirical data, mathematical models, or probability models (US EPA 2004). For this assessment, the risk is stressor-initiated, where the stressor is the release of zeta-cypermethrin to the environment. The following risk hypothesis is presumed for this screening level assessment: Based on ir?for.mation onpersistence, mode qf action, direct toxicity, andpotential indirect effects to trophic,foodwebs, tlie use qfzeta-cypermetltrin in accordance wit11tlzepi*oposedlabels will result in crdver-seeffects or1 survival,,fecundity,and/orgrowtli ofnon-target terrestrial and/or lrq~~atic animals. Ecological receptors that may potentially be exposed to zeta-cyperinethrin includeterrestrial and semiaquatic wildlife (i.e., mammals, birds, and reptiles), terrestrial plants and terrestrial plants in semi-aquatic areas, and soil invertebrates. In addition to terrestrial ecological receptors, aquatic receptors (e.g., freshwater and estuarinelmarinefish and invertebrates, and amphibians) may also be exposed to zetacypermethrin by its migration from the site of application to various watersheds and other aquatic environments via runoff accompanied by erosion and spray drift. Data from toxicity studies formed the basis for identifying potential endpoints, stressors, and ecological effects associated with uses of zetacypennethrin.Despite that exposure of aquatic and terrestrial plants to zeta-cypermethrin is likely, EFED is not concerned about the level ofphytotoxicity of zeta-cypermethrin products because its neural toxic mode of action is not expected to be a phytotoxic concern, there are no studies demonstrating adverse effects of zeta-cypennethrin or any other pyrethroid to plants, and no incident reports have reliably linked zetacypermethrin or any other compound in the synthetic pyrethroid class of chemicals to phytotoxic effects non-target terrestrial plants. 

### In addition, although zeta-cypermethrin degradate exposure to aquatic and terrestrial organisms is also possible, based on the assumption that cleavage of the ester bond moiety in the parent structure results in biologically inactive degradates, these compounds are not expected to present a significant risk to non-target organisms. 2. Diagram In order for a chemical to pose an ecological risk, it must reach ecological receptors in biologically significant concentrations. An exposurepathway is the means by which a pesticide moves in the environment from a source to an ecological receptor. For an ecological exposurepathway tobe complete, it must have a source, a release mechanism, an environmental transport medium, a point of exposure for ecological receptors, and a feasible route of exposure. 

### In addition, the potential mechanisms of transformation (i.e., which transformation products may fonn in the environment, in which media, and how much) must be understood, especially for a chemical whose 

### metabolitesltransformation products are of greater toxicological concern than the parent compound. The assessment of ecological exposure pathways, therefore, includes an examination ofthe source and potential migration pathways for constituents, and the determination of potential exposure routes (e.g., ingestion, inhalation, dermal absorption). Theconceptual model used to depict the potential ecological risk associated with zeta-cypermethrin is fairly generic and assumes that as a pesticide, zeta-cypermethrin is capable of affecting terrestrial and aquatic organismsprovided that environmental concentrations are sufficiently elevated as a result of proposed label uses. However, through a preliminary iterative process of examining fate and effects data, the conceptual model, i.e.,the risk hypothesis, has been refined to reflect the exposurepathways and the organisms that are most at risk (Figures 1 and 2). In the specific case of zeta-cypermethrin, the source and mechanism ofrelease may include ground or aerial spray applications to agricultural crops. For turf applications it is a granular application directly overthe turf. For termiticide uses it is to be applied directly to subterranean environments, or to building or structure surfaces,perimeters, and foundations. Surface runoff from the areas of application is assumed to depend on factors such as topography, irrigation, andrainfall events. Additional transport mechanisms include spray drift and wind erosion, which may potentially transport contaminants to the surrounding sites. In addition, direct deposition may result in contamination of food items that may be consumedby terrestrial organisms. The major point of exposure for aquatic organisms is direct effects from the water column, as well as sediment andpore water (gill/ integument uptake). However, indirect effects to aquatic organisms (especially fish) can also occur through impact to various food chains. Zeta-cypermethrin exposure to terrestrial animals is expected through ingestion of food items such as grass, foliage, and small insects.

### Stressor
Sourcel Transport Pathways
Sourcel Exposure Media

Exposure Point Receptors

Attribute Changes Zeta-cypermethrin applied as an emulsifiable concentrateto agricultural crops via groundlaerial broadcast foliagelfruit spray. I 6 t t t t 

## ;Volatilization

## ; ; /Wind 

## ; Deposition 

### 1 Suspension 

### ! Drift 

# m Erosion r----------------- I I I Leaching I 

### I Infiltration/Percolation 

### ------------------ I 

# I Terrestrial Food Residues (foliage,

fruit, insects) 

# 1 Gill1Integument Ingestion& Dermal Uptakeand Uptake 

# I 

# I I lngegtion
Birds, Mammals, Invertebrates Reptiles,Terrestrial and Vertebrates Invertebrates Amphibians 

# I

r------------- 

# I Individual Animals Reducedsurvival Reducedgrowth Reduced reuroduction r_----------------- 

## ; Individual Plants 

### ; ! Seedling emergence ! Vegetative vigor I------------------- 

## ; Plant ~ouulation 

## ; ; Reduced population 

## ; ! growth 

### ! IndividualAnimals Reducedsurvival Reducedgrowth Reduced reproduction

** The dotted lines represent unlikely routes of exposure/effects Figure 1. Ecological conceptual modelfor spray applicationsof zeta-cypermethrin.


### 24

### Stressor Granular zeta-cypermethrin applied to turf via broadcast ground application.


### Source1 Transport Pathways
Source1 Exposure Media

Exposure Point t Deposition 

# 1

itemsthat have bioconcentrated 

# 1 Ingestion 

# 1 Receptors



## I Reduced reproduction 

## I Terrestrial Oraanisms: Birds, Mammals, Reptiles,Terrestrial lnvertebrates



### Attribute Changes r----------------- Leaching I Erosion 

## ; InfiltrationIPercolation 

### ------------------

IndividualAnimals Reducedsurvival Reducedgrowth Plants Plants Gill1Integument Uptake and

lnge tion 

# I Aquatic lnvertebrates and Vertebrates

Amphibians 

# r-l

I Plant population Individual Plants 

## ; I Reduced 

## ; Seedling emergence 

## I
I I population Reduced survival Vegetative vigor '------------------I 1 , arowth ! Reduced growth 

# - -------------- Reduced 

# I reproduction

** The dotted lines represent unlikely routes of exposure/effects Figure 2. Ecological conceptual model for granular applications of zeta-cypermethrin.

### E. Analysis Plan 1. Preliminary Identification ofData Gaps and Methods Theprimary method used to assess risk in this screening-level assessment is the risk quotient (RQ) and follows closely methods outlined in the EPA Overview Document (EPA, 2004). The RQ is the primary risk value for the screening-level assessment and is the result of comparing measures of exposure to measures of effect. A commonly used measure of exposure is the estimated exposure concentration (EEC) and comlnonlyused measures of effect include toxicity values such asthe LDsoor NOAEC. Assessment endpoints and their respective measures of effect are listed in Table 

### 5. Theresulting RQ is then compared to a specified level of concern (LOC), which represents a point of departure for concern; ifthe RQ exceeds the LOC, then risks are triggered. Although not necessarily a true estimate ofrisk since there is no estimated probability of effect, in general, thehigher the RQ, the more certain the potential risks. Risk presumptions, along with the corresponding RQs, equations, and LOCs are summarized in Appendix 

### F. Levels of concern (LOC) are the policy tool for interpreting risks from direct pesticide effects and have a magnitude, duration, frequency, and spatial extent. The magnitude is set by the risk presumption for each endpoint. The frequency of potential risk is once every ten years for aquatic endpoints and one in everyten foliage samples for terrestrial risk. The spatial extent is defined by the use area, and the areas downstream and areas potentially affected by spraydrift. Generation ofrobust RQs are dependent on the quality of data from both fate and toxicological studies. The adequacy of the submitted data was evaluated relative to Agency guidelines. The following identified data gaps for ecological fate and toxicity endpointsresult in a degree ofuncertainty in evaluating the ecologicalrisk of zeta-cypermethrin. There isuncertainty regarding chronic toxicity to freshwater invertebrates and estuarinelmarinefish because no data are currently available. To assess risk to these taxonomic groups, RQs were based on chronic NOAEC values derived using acute-tochronic ratios. Risks to terrestrial plants and terrestrial plants in semi-aquatic areas were not evaluated because toxicity data on these receptors are not available; however, EFED is not concerned about the level of phytotoxicity of zeta-cypermethrin products because its neural toxic mode of action is not expected to be a phytotoxic concern, there are no studies demonstrating adverse effects of zeta-cypennethrin or any other pyrethroid to plants, and no incident reports have reliably linked zeta-cypermethrin or any other compound in the synthetic pyrethroid class of chemicals to phytotoxic effects to non-target terrestrial plants. Results of acute toxicity studies in freshwater fish and invertebrates indicatethat the zetacypermethrin degradate 3-phenoxy benzoic acid is much less toxic than the parent compound. No information is available on the toxicity of other zeta-cypermethrin degradates or on the toxicity of any degradate to terrestrial organisms; therefore, risk resulting from exposure to zeta-cypermethrin degradates could not be evaluated in this assessment. However, based on the assumption that cleavage ofthe ester bond moiety in theparent structure results in biologically inactive degradates, these compounds should not present a significant risk to non-target organisms.There were no chronic data available to estimate chronic risk of zeta-cypermethrin exposure to benthic organisms, there were no acutetoxicity data for benthic organisms based on pore water concentrations, and estimates of acutetoxicity to benthic organisms based on sediment concentrations may underestimate toxicity because the water-sediment systems were not at equilibrium. Therefore, acuteto chronic ratios were used to derive chronic NOAEC values for the purposes of this risk assessment, the equilibrium partitioning (EqP) theory and definition ofthe koc were used to estimatetoxicity values in terms of pore water concentrations, and additional sediment toxicity studies have recently been submitted to the Agency by the Pyrethroid Working Group (PWG) to address these uncertainties. 2. Measures to Evaluate Risk Hypotheses and Conceptual Model

a. Measures of Exposure Themaximum rate of application for the emulsifiable concentrate to crops is 0.05 Ib a.i.1A with a maximum of 6 applicationslseason and a minimum interval of 7 daysbetween applications (a total maximum seasonal application rate of 0.3 lbs a.i./A). However, for this risk assessment EFED assumed that zeta-cypermethrin was applied at a maximum of 6 times per year. If there are conditions under which there is more than one growing season for a crop within a single year, exposure estimates and risk to aquatic and terrestrial organisms could be significantly underestimated. Examples of crops that have multiple seasons where this may be a concern include leafy, brassica, and fruiting vegetables in CA, AZ, FL, GA, LA, NC, TX, andlor SC. It is assumed for pesticides which have residential outdoor uses (applications to home lawns, gardens, parks, etc.) that runoff water from rain andlor lawn watering may remove pesticide to storm sewers and then directly to surfacewater. However, in general, outdoor residential uses are comprised of multiple, relatively small, temporally and spatially variable applications that are not simulated in agricultural models. Therefore, there is some uncertainty in the aquatic exposure assessment because a model specifically aimed at simulating pesticide fate and transport in a complex urban landscape has not yet been developed to generate exposure estimates strictly for urban areas. There is also uncertainty with respect to the exposure due to the use of zeta-cypermethrin as a termiticide in residential or industrial areas because the Agency does not have a model to calculate the EECs for this use. However, the EFED believes that the exposure dueto the termiticide subterranean uses are likelyto be minimal due to the nature of the application method, and the fate properties of zeta-cypermethrin (strongly adsorbed by soils). However, the perimeter treatments are more uncertain because the chemical may be exposed to the elements. Zeta-cypermethrin seems to be degraded mainly by metabolism. 

### In soils, the metabolism appears to be somewhat slower than in aquatic media. Therates for aerobic and anaerobic soil metabolism were about 60 and 52-63 days, respectively. 

### In contrast, the rates for 

### - aerobic and anaerobic aquatic metabolism were 9-10 and 14-1 7 days, respectively. All abiotic processes appeared to be insignificant dissipation mechanisms for zetacypermethrin. The chemical appears to be stable to hydrolysis, except on alkaline media(at pH 9 tlp2 days). In the presence of light, zeta-cypermethrin photolyses relatively slowly, both in water and on soil. Thepotential impact to water quality from the use of zeta-cypermethrin is mostly due to the parent. The laboratory studies indicate that zetacypermethrin is moderately to highlypersistent under most environmental conditions. This makes the chemical available for lengthy periods of time for runoff. The impact of zeta-cypennethrin would also be affected by its mobility. The available studies indicated that zeta-cypermethrin has very low mobility in the various soils tested. Therefore, the means to runoff for zeta-cypermethrin from crop sites to adjacent bodies of water can be runoff accompanied by erosion. Another means to reach adjacent waters is via spray drift. For agricultural uses, exposure concentrations for aquatic ecosystems assessments were estimated based on EFED's Tier 2 aquatic model PRZMIEXAMS. A graphical user interface (pe4), developed by the EPA <Ilttv. \I \\ n .cna.rrot oppclkd 1 ~nodels 'Mntcr>, was used to facilitate inputting chemical and use specific parameters into the appropriate PRZM input files (inp) and EXAMS chemical files. This approach employs PRZM, which simulates the processes in the agricultural field, such asrunoff and erosion, on a daily time step. The runoff and erosion flux output data from PRZM are used as chemical loadings to EXAMS, which simulates surface water in order to predict the EECs. Five PRZM field (crop) scenarios were modeled: CAgrapes, GApeaches, IDpotatoes, PA apples, and FL trrrf: An effort was made to cover all areas ofthe continental United States and to select crops with the highest application rates. EECs for ecological risk assessment were determined using a pond modeling scenario which describes a generic scenario for the EXAMS component of the modeling exercise. It was found that the EECs for CA grapes and ID potatoes were very similar. Therefore, sincethey would yield similar RQs, only the CA grapes scenario was kept in the assessment. Theresults from PRZMIEXAMS for the ID potatoes scenario appear in the Appendix 

### B. Since zeta-cypermethrin, like other pyrethroids, binds to organic carbon (mean Koc = 141,700mg1L) and eventually accumulates in aquatic sediment, toxic exposure to organisms living in this media is a concern. EFED has estimated zeta-cypermethrin sediment exposure to benthic organisms by calculating sediment and pore water exposure values using the PRZMIEXAMS model. Screening level RQs for sediment dwelling organisms were estimated with an extrapolation method recommended by the Office of Water (USEPA).This was based on the Agency Equilibrium PartitioningSediment Guidelines (ESG)under the Clean WaterAct [CWA Section 304(a)(2)]. After consultation with the OW, EFED adopted the equilibrium partitioning (EqP) sediment method to be used when sediment toxicity and exposuredata are not available(Appendix G).This extrapolationmethod is useful for estimating potential sediment exposure values, aswell as sedimenttoxicity values that can be used in a screeninglevel risk assessment. The EqP theoryholds that a nonionic compound in the sediment partitions between sediment organic carbon, interstitial (pore) water and benthic organisms (Di Toro et al., 1991, U.S. Environmental Protection Agency, 2000~). At equilibrium,if the concentrationin any phase is known, then the concentration in the otherphases can be predicted through the organic1carbon soilpartition coefficient. The EECs are calculated from the pore water concentration (an output from PRZMI EXAMS) through the 

### Gc. The measurement of the level of drift was performed with the model AgDRIFTB, which is capable to determine the level of drift to the EXAMS standard pond from apredetermined buffer zone. The ground portion of the model was validated with actual field data. For exposure ofterrestrial organisms to spray applications of zeta-cypermethrin, residues in potential dietary sources (e.g.,vegetation and insects) for marmnals and birds were estimated using the conceptual approach given in the Tier 1 model T-REX (T-REX, Version 1.2.3, dated, August 8, 2005). This model provides estimates of concentrations (maximum, or upper bound, and average) of chemical residues on the surfaces of different forage that may be sources of dietary exposure for avian, mammalian, reptilian, or terrestrial-phase amphibian receptors. The surfaceresidue concentration (ppm) is estimated by multiplying the application rate (pounds active ingredient per acre)by a value specific to each food item. The T-REX model was run for four crop use scenarios: stone fruits, canola,non-grass animal feeds, and barley. These scenarios were selected to represent a variety of crops and use scenarios in the continental US. For acute exposure of terrestrial organisms to granular applications of zeta-cypermethrin, exposure and risks were estimated with the conceptual approach using the ~~~~lft' method given in the Tier 1model 

### T-REX. Terrestrial EEC values were calculated based on an estimation of loadings ofpesticide per unit area. The T-REX model was run the maximum use scenario of granular zeta-cypermethrin on turf. For chronic exposure of terrestrial organisms to granular zeta-cypermethrin, only direct ingestion of soil invertebrates that have bio-concentrated zeta-cypermethrin residues of granules in soil was considered. This estimation of earthworm concentration was calculated using a fugacity-based (equilibrium partitioning) approach based on the work of Trapp and McFarlane (1995) and Mackay and Paterson (198 1 ). b. Measures of Effect Measures of ecological effects are obtained from a suite of registrant-submitted guideline studies conducted with a limited number of surrogate species. Thetest species are not intended to be representative of the most sensitive species but rather were selected based on their ability to thrive under laboratory conditions. Measures of effect are based on deleterious changes in a receptor as a result of chemical exposure. Functionally, measures of effect typically used in risk assessments include changesin survival, reproduction, or growth as determined from standard laboratory toxicity tests. The focus on these effects for quantitativerisk assessment is dueto their clear relationship to higher-order ecological systems such as populations, communities, and ecosystems. Although monitoring data may also be used to provide supporting lines of evidence for therisk characterization, monitoring data is lacking for this new chemical. In addition, effects other than survival, reproduction, and growth may be considered, rarely are they used quantitativelyto estimate risks since, in many cases, the relationship between these effects and higherorder processes is tenuous at best. Commonly used laboratory-derived toxicity values include estimates of acute mortality (c.g.,LD50, LC50, or EC50) and estimates of effects due to longer term, chronic exposures (e.g.,NOAEC, NOAEL). The latter can reflect changes seen in mortality, reproduction, or growth. Registrant-submitted data are available for all cypermethrin products (alpha-, beta-, theta-, and zetacypermethrin); the Agency assumes equivalent toxicity is bridging the TGAI data for risk assessment purposes. Limited toxicity data on the zeta-cypernethrin degradate 3-phenoxybenzoic acid has also been identified and incorporated into this risk assessment. A complete summary of the measures of effect based on toxicity studies for different ecological receptors and measures of effect (acutelchronic) for cypermethrin (TGAI) is given in Table 

### 5, with study details provided in Appendix 

### E.

### c. Measures 

### ofEcosystem and Receptor Characteristics The changes in ecosystems and free-ranging receptors in response to proposed uses of zeta-cypermethrin are not explicitly quantified in this assessment. It would be nearly impossible to addressthe myriad of uses, ecosystems and receptors that may interact as a result of zeta-cypermethrin use. Instead, the measures of exposure and measures of effect areused to generate estimates of risk that can be applied to a wide variety ofreceptorlecosystem combinations that are represented by the specified assessment endpoints. The assessment endpoints specified in 

### Table 5can be summarized as survival, growth, and reproduction of terrestrial and aquaticreceptors to include birds, mammals, reptiles, amphibian, fish, and invertebrates. Theresponse ofthese receptors to zeta-cypennethrin exposure is represented by a small number of toxicity studies on representative or surrogate species. Hence, there is uncertainty regarding the response of a freeranging receptor since data for all species potentially exposed arenot available. The lowest available measure of effect for a given assessment endpoint is used to calculate RQs to accommodate for some of this inherent uncertainty. However, the extent to which this is sufficient is unknown. For the assessmentsusing the Tier I1 aquatic model PRZMIEXAMS and the Tier I terrestrial model 

### TREX, the ecosystemsthat are modeled are intended to be generally representative of any aquatic or terrestrial ecosystem associated with areas where zeta-cypermethrin is used. Thereceptors addressed by the aquatic and terrestrial risk assessments for zeta-cypermethrin are summarized in 

### Table 4. For aquatic assessments, fish and aquatic invertebrates in both freshwater and estuarine/marine environments are represented. For terrestrial assessments, three different size classes of small mammals arerepresented, along with fivepotential foraging categories (short grass, tall grass, broadleaf plantslsmall insects, fruitslpods/large insects, and seeds). For birds, three different size classes are represented, along with four potential foraging categories are considered (short grass, tall grass, broadleaf plantslsmall insects, and fruits/pods/seeds/largeinsects). 111. 

### Analysis A. 

### Use Characterization Zeta-cypermethrin is an insecticide that is formulated as an emulsion, an emulsifiable concentrate, and a granular. Zeta-cypermethrin is already used to control many pests, including those of cotton, alfalfa, bulb vegetables corn, fruiting vegetables (except cucurbits), legume vegetables, succulent edible-podded peas andbeans, rice, sorghum (grain) and millet, soybeans, sugarbeets, wheat and triticale crops. Theregistrant is also requesting tolerances or new agricultural uses for the emulsifiable concentrate to include cilantro, head and stem brassica vegetables, leafy vegetables (except brassica), sunflowers, grass forage, fodder, hay group, canola rapeseed, barley, grapes, tree nut group (almond, pecan), berries, peanuts, root andtuber vegetables, cucurbit vegetable group, non-grass feeds (forage, fodder, straw and hay), pome fmits, and stone fruits. Furthermore, a granular zeta-cypermethrin formulation isproposed for use on turf on residential lawns, home perimeters, gardens, and other industrial non-agricultural areas, while a zetacypennethrin emulsion is proposed for use as a tenniticide. Zeta-cypermethrin emulsifiable concentrate formulations are to be applied as a groundlaerial broadcast foliagelfruit spraywhile the granular formulations are to be applied by ground broadcast equipment to infested areas. Themaximum rate of application for the emulsifiable concentrate to crops is 0.05 lb a.i.1A with a maximum of 6 applications/season and a minimum interval of 7 days between applications (a totalPecans RIL~ Sotghum Soybean$ 5uga1cdne Wheat 0 05 0 05 0 05 0 05 0 05 0 05 Crops propoved in C~lantro Head aud Stem Bra~sica Vegetables L.eafy Vegetables (except Brassica) Sunflowers Grass forage, fodder, hay grouP Canola, Rapeseed Uallej Grapes

rree nut group (almood, pecan) Berrie? Peanuts Hoot aud ruber Vegetables 6 4 5 6 4 5 th~s Section 3: 0.05

0.05

0.05 0.05

0.05

0.05 0.05 0.05

0.05 0.05 0.05

0.05 0 3 0 2 0 25 0 3 0 2 0 25

6

6

6 5

4

4 5 6

5 6 6

6 NS 7 10 7 21 14

0.3

0.3

0.3 0.25

0.2

0.2 0.25 0.3

0.25 0.3 0.3

0.3 G 6.A G A G,A G A 6. A 0 0 0 0 0 0

7

7

7 NS

7

7 14 7

7 7 NS

NS G, A

G,A
G, A G,A

G,A C, A G, A G,A
G, A G G, A
G, A 0

0

0 0

0

0 0 0

0 0 0

0

### B. Exposure Characterization J

1. Environmental Fate and Transport Characterization Termiticide

a. Summary May be applied as subterranean treatment to critical areas, by removing the soil and applyi~~g the material as a liquid, as a preconstruction subterranean treatment, postconstruction soil treatment (drill holes in the foundation to allow for the application), or foam applications for spot tratments, and perimeter treatment.

Theregistrant has submitted an extensive and complete body of data. Based on mostly valid and some supplemental studies, the behavior of zeta-cypennethrin in the environment can be predicted with reasonable certainty. Studieswere performed with cypermethrin or with zeta-cypermethrin. The field study appears to corroborate what is predicted by the laboratory studies. It appears that zeta-cypermethrin degradation is mainly theproduct of metabolic activity. Aerobic and anaerobic soil metabolism were found to be about 60 and 52-63 days, respectively. 

### In contrast, the rates in aquatic media appear to be more rapid, with aerobic and anaerobic aquatic metabolism of 9-10 and 14-17 days, respectively. All abiotic processes appeared to represent relatively insignificant dissipation mechanisms for zeta-cypermethrin. Zeta-cypermethrin appears to be stableto hydrolysis (except in alkaline media at pH 9 t:p2 days) and in the presence of light (photolysis in water was 20 

### - 36 days and on soil, 57 

## - 100days). In the field, the half-lives were 12.2 and 3.2 days in CA and LA, respectively. 

### In aquatic field dissipation studies, the halflives indicated persistence, with 181 and 126days in CA and LA, respectively. Cypermethrin shows a inoderate potential for bioaccumulation in fish, with lnaxilnum BCF of 468 for whole fish in a 28 day study. Depuration appeared to be moderate, with near 10-1 5%ofthe initial residues remaining after 2 1 days. Themajor transformation products for zeta cypermethrin are cis- and trans-DCVA, 3-PBA and 3- phenoxybenzoic acid. They are the product ofthe cleavage ofthe esterbond.

G=ground;A=aerial; IJLV=ultra low volu~ne application;NS=Not specified. 

### ' For use on residential lawns, home perimeter, ornamental and flower gardens.

b. HydrolysisCypermethrin was approximately stableto abiotic hydrolysis in pH 5 and 7 solutions, while in pH 9 solutions, the half-lives were 1.8-2.5days (cyclopropyl and the benzyl [I4c]-labeledmaterials). Two major degradates were detected in the pH 9 solutions. A mixture of cis- and trans-DCVA steadily increased to 78.7% at hour 120. And 3-phenoxybenzaldehyde, which increased to 64.9% at hour 120.

c. Photolysis Cypermethrin photolysed in aqueous solutions exposed to sunlight,with half-lives of 20 and 36.2 days, compared to an essentially stable dark control. One major individual cyclopropyl-labeled degradate (maximum 21.2% of the applied on day 30) was not identified). Another major degradate was 3- phenoxybenzoic acid which steadily increased to 34.6% (day 35) in the sunlight irradiated solution. On a thin layer of sandy loam soil, cypermethrin, exposed to sunlight, degraded with half-lives of 56.2 and 56.5 days, compared to dark controls of 75.9 and I00 days. The EFED's calculated half-lives for photodegradation only (substracting the contribution presented by the dark control). Theresults were 215 and 128days. The major degradate was cypermethrin amide which steadily increased onboth the irradiated soil and on the dark control (observed in both labels at up to 13.3%). All values for the phenyl and the cyclopropyl labels, respectively. Cypermethrin has a relatively low solubility and vapor pressure (reported solubility from 0.2 to as low as 4.0x10-bg/~, and vapor pressure between 2.5~10.~ torr and 6.7x10-~ torr or 8.8 x 10.'~ atm). The corresponding Henry's Law Constant varies from 1.6x10-' at~narn~l~nol and 3.4x10-' atmarn~z/mol. Cypermethrin is not expected to have any significant potential for volatilization from water or soil, and therefore, air photolysis would be a very little component in the environmental fate of the chemical. d. Metabolism In an aerobic soil inetabolisin study, conducted on a sandy loam, cypermethrin degraded with calculated half-lives of 60.7, and 59.8 days, for the cyclopropyl, and phenyl labeled material, respectively. In the cyclopropyl labeled study, the major degradates were C02 (a maximum of 35.8%of applied at day 128), and a mixture of cis- and trans-DCVA (which increased to a maximum of 24.2% of applied on day 62 and then decreased to 4.4% by day 150).

### In the phenyl labeled study, there was one major degradate: COr which steadily increased to a maximum of 46.1% of applied on day 150.The minor degradate 3- phenoxybenzoic acid was 28.4%of the applied throughout the study. Some supplemental studies show shorter degradation half-lives for cypermthrin. In three foreign soils, the half-lives were 2.7, 7.3, and 6.9days in British clay loam, loamy sand soil, and peat soil. 

### In all three cases, the major degradate was I4co2, which reached between about 60 and 70% of the applied by 25 days. The studies were conducted only with the benzyl labeled material. The onlynon-volatile degradate detected at >lo%was 3-phenoxybenzoic acid, which was up to 12.3% (day 1)in the peat soil. In an anaerobic soil metabolism study, cypermethrin was incubated aerobically for 32 days in the same sandy loam soil used in the aerobic study. After this period, the soil was flooded to establish anaerobic conditions. At the time the anaerobic conditionswere established, cypermethrin accounted for about 66- 67% ofthe applied. Based upon cypermethrin declines during 60 days of flooded conditions,the anaerobic soil metabolism half-lives were 5 1.5 and 62.9 days for the cyclopropyl and thephenyl labeled cypermethrin,respectively. The major cyclopropyl labeled degradate was a mixture of cis- and transDCVA (inax. of 33.3%ofthe applied 30 days after flooding). The major phenyl labeled degradate was 3-phenoxybenzoic acid (max. at the end ofthe study, 60 days, with 25.9% of the applied). C02 increased from 13.2%of applied on day 0 of the flooded period to 20.9% (day 60).

e. SedimenttWaterSystems The sedimentlwater studies were conducted with zeta-cypermethrin. In one aerobic aquatic metabolism study, total [14~]-zeta-cypermethrin (sedimentlwater system), at a nominal application rate of 0.15 ppin, degraded with calculated half-lives of 8.9 and 10.1days for the phenyl and cyclopropyl radiolabel materials, respectively, in flooded clay loam sediment that was incubated aerobicallyin the dark at 25f 1 OC for up to 30 days. The approximate DT50obtained by inspection of the data appeared to be about 3 days. Close inspection of the data reveals that the dissipation of the cypermethrin becomes slow (perhapsbiphasic) with time, which explains the long calculated halflives and short observed DT50's. In the phenyl label study the major degradate was 3-phenoxybenzoic acid, which increased to a maximum of 48.4% at 21 days posttreatment Evolved 

## I4co2 reached 7.1% of the nominal application 30 days posttreatment. Nonextractable [I4c] residues were a maximum of 16.8%ofthe applied at 30 days posttreatment.. 

### In the cyclopropyl label study, the major degradate was trans-DCVA, which was a rnaximum of 48.8%of the nominal application by 30 days posttreatment. 

### In addition, cis-DCVA was a maximum of 19.4%ofthe applied at 30 days. 

### In an anaerobic aquatic metabolism study, ['4~]-zeta-cypermethrin, at a nominal application rate of 0.15 ppm, degraded with half-lives of 13.8days and 16.5days, in flooded clay loam sediment, incubated anaerobically in the dark, at 25*1 OC for up to 90 days (benzyl label) or 183days (cyclopropyl label). 

### In studies conducted with both radiolabels, the majority ofthe radioactivity of the parent was associated with the sediinent. In the benzyl label study the major degradate was 3-phenoxybenzoic acid. 

### In the sediment, it reached a lnaximuln in the sediment at 30 days posttreatment, with 42.5% ofthe applied. Evolved I4c02 was 69.8 of the applied after 90 days posttreatment. Nonextractable radioactivity was a maximum of 14.7%of the applied at 14daysposttreatment. In the cyclopropyl label study, the major degradate was trans-DCVA, which increased in the aqueous phase to a maximum of 34.1% of the applied by 30 days and decreased to 10.8%by 18 1-183 days. In the sediment, the same degradate, was present at a maximum of 31.3%of the applied by 71 days posttreatment. By 183days it was only 21% of the applied. Nonextractable [I4c] residues were a maximum of 14.0% ofthe applied at 183days posttreatment. f. Mobility Data on the adsorption and desorption ofcypermethrin were provided for four soils with a variety of properties, like %OC ranging from 0.2 to 2.3. The reported adsorption and desorption constants for cyperlnethrin binding to the 4 test soils indicated low mobility for cypennethrin in all four soils. The 

### Kqads) ranged from 4 16to 1900,while the value corrected for organic carbon, 

### Koc. ads, ranged from 20,800 and 328,500. lln values were between 1.16 and 1.47. There are several aspects ofthe above data that are unusual and are asyet unexplained, the major one being lower desorption than adsorption values for 3 of the soils. Binding isotherms and Freuendlich parameters were not provided for any ofthe cypennethrin degradates.14 

### In an aged leaching study, C-cyclopropyl labeled and I4c-benzyllabeled cypermethrin were applied to the tops of 30 cm soil columns containing a sandy loam soil (1 1 % clay, 1.8%OM,pH 6.9), aged for 30 days and then leached with 20 inches of water. Of the total '4~-cyclopropyl labeled residues added to the top of replicate soil columns, 11.3-13.6%was recovered froin the leachate. Ofthat amount, 89-97% was identified as a mixture of cis- and trans DCVA. Of the total I4c-benzyllabeled residues added to the top of replicate soil columns, < 1% was recovered from the leachate. Theresults ofthis aged soil column leaching study indicated that the degradate DCVA was substantially more mobile than cypermethrin and benzyl labeled degradates such as 3-phenoxybenzoic acid. Conclusions with respect to the mobility of benzyl labeled degradates should be limited by the relatively low levels of such degradates formed within the relatively short aging period of 30 days.

g. Field Dissipation In a terrestrial field dissipation study, conducted at Madera, CA, cypermethrin in the EC fonnwas applied three times at 0.2 Ib a.i.lAiapplication to a bare silt loam soil. Based upon dissipation in the top 0-3" soil cores, half-life of 12.2 days was estimated over the 28 days required for the chemical to dissipate to a level below the detection limit. Cypennethrin was detected in 3-6" cores collected immediately after each application (max. 33 ugikg), and days 2, and 4 after the 3rd application (20 and 29uglkg, respectively). Cypennethrin was detected at 10 uglkg only in one 6-12" core collected 2 days after the last application, but it was not detected above a detection limit of 7 uglkg in any soil cores collected below 6 inches. The degradate 3-phenoxybenzoic acid was detected in 0-3" cores collected immediately after the 

### 2nd and 3rd applications (8 and 17uglkg, respectively), and the following days after the 3rd application (max. 32 uglKg on day 4). It was not detected above a detection limit of 7 uglkg in any soil cores collected below 3 inches. Potential degradates cis- and trans-DCVA were not detected above a detection limit of 7 uglkg in any of the soil cores. No other degradateswere monitored in the study. Total rainfall and irrigation combined during the study was 16.5inches. In another terrestrial field dissipation, conducted at Cheneyville, LA, cypermethrin in the EC form was applied three times at 0.2 lb a.i./A/application to a bare loamy sand soil. Based upon dissipation in the top 0-3" soil cores, the dissipation half-life for cypermethrin was 3.2 days over the 28 days required for the chemical to dissipate to a level below the detection limit. Cypermethrin was not detected above a detection limit of 7 ugikg in any cores collected below 3 inches. The degradate trans-DCVA was detected in 0-3" cores collected on a few days after the 3rd application: days 2 and 7 (16 and 8uglkg, respectively). The degradate 3-phenoxybenzoic acid was detected in 0-3" cores collected immediately after the 2"d and 3rd application (10 and 20 ugfkg, respectively), and 2 days after the 3rd application (44 uglkg). The degradate cis-DCVA was not detected above a detection limit of 7 uglkg in any ofthe soil cores. None of the analytes were detected above a detection limit of 7 uglkg in any ofthe soil cores collected below 3 inches. Total rainfall and irrigation during the study was 53.7 inches.Two aquatic field dissipation studies wereperformed with zeta-cypermethrin on rice plots 

### in California and Louisiana; these studies provide limited supplemental infonnation. Thereported half-lives of 

### 181 and 126days in CA and LA, respectively, do not agree with the values of the aerobic aquatic or the anaerobic aquatic metabolism studies (tI,<'s ranged between 

### 9 and 

### 17 days). Thereported aquatic field dissipation half-lives included the sedimentsonly, not the flood water. h. Bioaccumulation Bluegill sunfish were exposed in separate tests to nominal 

### 0.20ug/L cyclopropyl and benzyl labeled cypermethrin in flow-through tanks for a 

### 28 dayuptake phase. After 28 days of exposure thebluegill sunfish were placed in cypennethrin free water for a 2 1 day depuration phase. Maximum total cyclopropyl residue BCFs were observed on day 

### 28: 161 for edibletissue, 833 for viscera, and 444 for whole fish. BCFs gradually increased with increasing exposure time, and steady state may not have been obtained by the last day of exposure. After 21 days depuration, total cyclopropyl residues



# . declined from 

### 29 uglkg to 3.2uglkg in edible tissues, from 

### 150 uglkg to 

### 13 ugkg in viscera, and from 80

uglkg to 11 uglkg in whole fish. Maximum total benzyl residue BCFs were observed on day 

### 28 for edibletissue, and day 21 for viscera and whole fish. Max. BCF's were: 

### 111 for edible tissue, 

### 579 for viscera, and 

### 468. BCFs rapidly increased with increasing exposure time and appeared to reach approximate steady state by only 

### 1 day of exposure for viscera and whole fish. For edible tissue, BCFs gradually increased with increasing exposure time, and steady state may not havebeen obtained by the last day of exposure. After 21 days depuration, total benzyl residues declined from 

### 21 uglkg to 

### 2.9uglkg in edible tissues, from 93 uglkg to 

### 12 ugkg in viscera, and from 

### 57 uglkg to 

### 10 ugikg in whole fish. i. Nomenclature andDegradation Products of Cypermethrin trans-DCVA = 

### (*)trans-3-(2,2-dichloroethenyl)-2,2-dimethylcyclopropane carboxylic acid cis-DCVA = 

### ~cis-3-(2,2-dichloroethenyl)-2,2-dimethylcyclopropane carboxylic acid MPB-acid = 3-PB-acid = 3-phenoxybenzoic acid 3-PBA = 3-phenoxybenzaldehyde 2. Measures ofAquatic Exposure

a. Aquatic Exposure Modeling For agricultural uses, exposure concentrations for aquatic ecosystems assessments were estimated based on EFED's Tier I1 aquatic model PRZMIEXAMS. A graphical user interface (pe4), developed by the EPA <11111): itn L{ .cl-t,l.~cn ov~clcd 1 m~)dcla ivaies>, was used to facilitate inputting chemical and use specific parameters into the appropriate

### PRZM input files (inp) and EXAMS chemical files. ThePesticide Root Zone Model (PRZM) field or orchard crop scenario is the basic file which describes the local or regional cliinatological information, soil hydrology, soil characteristics, crop characteristics, and the pesticide properties necessary to determinepesticide loadings to ground or surface water. This basic file constitutes the first part of the "exposure scenario." It simulates the processes in the agricultural field, such asrunoff and erosion, on a daily time step. The runoff and erosion flux output data from PRZM areused as chemical loadings to EXAMS (Exposure Analysis Modeling System), which simulates surfacewater inorder to predict the EECs. The PRZM scenario selected for modeling were California grapes, Georgia peaches, Idahopotatoes, Pennsylvania apples and Florida turf. EECs for ecological risk assessment were determined using a pond inodeling scenario which describes a standard scenario for the EXAMS component of the lnodeling exercise (EXAMS Mississippi pond). To determine the level 

### of spray drift with the buffer zones imposed in the label for this chemical, the model AgDRIFTB was utilized. Following is a table of input parameters for zeta-cypermethrin. It was found that the EECs for CA grapes and 

### ID potatoes were very similar. Therefore, since they would yield the same RQs, only the CA grapes scenario was reported in the assessment. Theresults from PRZMIEXAMS for the ID potatoes scenario appear in the Appendix 

### B.
Table 7. Input Parameters Parameter (units) Output File Name Chemical Name CropNarne

Application Rate (Kga.i./ha) Day of Application (day-month)

Number of Applications Allowed Interval between Applications (days) Koc

Aerobic Soil Metabolis~n (days)

Incorporation Depth Method of Application Buffer Zone (ft.) Application Efficiency (fraction)
Spray Drifi (fiaction)

Solubility in Water (ppm)

Aerobic Aquatic Metabolistn (days) Utilized in PRZMIEXAMS Value(s) zcyper Zeta-cypamcthrin C'A gapes GA peaches ID potatoes PA apple FL turf 0.056 0.252 for turf C'A grapes 01-07 GA peachcs 0 1-07 ID potatoes 2 1-08 PA apples 15-08 FL turf 0 1-06 6 I for FL turf 7 days for grapes, potatoes, peaches and apples, 3 days for cotton. 141,700

61

0.0 in Ground or Aerial 25 ground, 150 aerial 1.OO for turf 0.99 for peaches and apples 0.95 for other crops 0.0 for turf 0.028for peaches and apples 0.039 for othet.crops 0.040

10.7 for Zeta-cypermethrin: Sources
--- Label label

ILabel

---

Label Label

MRID: 42129003

MRID: 42 156601

Label Label Label
---
AgDRIFT

Laskowski. 2002

MRlD 45920801 Comments
--- Proposed label Mustang Max and Fuly lnsecticides Mustang Max and Futy Insecticides

Mustang Max (0.050Ib aiIA; 0.225 Ib a.i./Afor turf) Estimated from ~netadata tile.

Mustang Max and Fury Mustang Max and Fury
Represents the average bc value among four values ranging from 20,800 to 328,000 mVg; the KQ~ model was utilized asper recommendation of the SAP. Represents the 90"' percentile of the upper confidence bound on the mean of two half-life values: 60.7. 59.8days; mean = 60.25 days; std. dev. =0.45 days Mustang Max and Fury Mustang Max and Fu~y Mustang Max and Fury EFED guidance on input parameters for PR%M/EXAMSdated 2128102 rurf is a granular application, peaches and apples are airblast applications, and the other crops are aerial applications. 10X the actual solubility as per EFED guidance on input parameters for PRZMIEXAMS. At 20°C. Laskowski, 2002 Rev. Environ. Contam. Toxicol. 174:49-170 Represents the 90"' percentile of the upper contidence bound on theTable 7. Input Parameters Parameter (units)

Anaerobic Aquatic Metabolism (days)

tlydrolysis at pti 7 Aqueous Photolysis @ pH 7 (days) Molecular Weight (glmole) Vapor Pressure (tonor mmHg) Henry's Law Constant (atrn-rn';mol) Environment Field Size Runoff PRZM Scenario

Metfile Scenario

CAM (C'hernicalApplication Method) FEXTRC, Foliar extraction PI.DKRT, Decay rate on foliage PI-VKRT. Volatilization rate from Ibllage IIPI'KF, llptake factor

Table 8. Estimated environmental concentrations ofzeta-cypermethrin (ppb) in the water column, benthic pore water, and benthic sediment. Utilized in PRZMIEXAMS

Value(s)

18.1

Stable 36.2 416.3 2.5 x 10.' 3.4 10.' pond298.exv Pond overall CAgtapesOC.txt CiApeaches.txt IDNpotato-Ni~uigC,txt PAappleC. txt FLtu~ff .txt Gape
- w93 193.dvf Peach
- w038 13.dvf Potato
-w24156.dvf Apple - w 14737.dvf Turf w 12834.dvf 2 0.5 0 0 0

Crop Scenario

CA Grapes"

GA Peaches'

PA Apples " W~ite Benthic Pore Water C'oncenh-ations? Write Benthic Sediment File'? for Zeta-cypermethrin: Sources

MRlD 42156602

MRlD 42620501 MRlD 42395701 Laskowsky 2002 Laskowsky 2002 Laskowsky 2002

--- --- ---

-..

---

..-

Media Water Column Benthrc Pore Wate~ Benthrc Sednnent

Water Column Benth~c Pole Water Benth~c Sed~ment Wata Column Benthrc Pole Wate~ Benth~c Sed~ment Comments mean of two half-life values: 8.9 and 9.8 days; rnean = 9.35 days; std. dev. =0.45 days Represents the 90"' percentile of the upper confidence bound on the mean of two half-life values: 13.8 and 16.5 days; mean = 15.15 days; std. dev. = 1.35 days
--- --- Laskowski, 2002 Rev. Environ. Contarn.Toxicol. 174:49-170 Laskowski, 2002 Rev. Environ. Contam. Toxicol. 174:49-170 Laskowski, 2002 Rev. Environ. Contam. Toxicol. 174:49-170 Default for pond scenario. as opposed to index reservoir.
--- Selected to be representative of crops existent and new crops, taking into consideration geographical areas. As indicatedby the shell (pe4).

Linear foliar based on crop canopy EFED guidance on input parameters for PRZMIEXAMSdated 2/28/02 EFED guidance on input parameters for PRZMIEXAMS dated 2/28/02 EFED guidance on input parameters for PRZMIEXAMS dated 2/28/02 EFED guidance on input parameters Yes Yes

Peak 0 0841 0 00159

9 04 0 201 0 00255

144 1 46 0 0197

112 --- for PRZMIEXAMS dated 2/28/02 Necessa~y to calculate the benthic risk quotients.

21-day 00150 0 00137

7 79 0 0195 0 00225

12 8 0 122 0 0173

80 3 60-day 0 0106 0 00104

5 89 0 01 19 0 00161

9 15 0 0641 0 0142

71 9At first glance at Table 

### 8, it is noted that all three types of peak EECs followed the sametrend. Apples had thehighest peak EECs while turf had the lowest. The turf scenario had the lowest peak EEC despite the fact that it had thehighest application rate, and only one application. It ispossible that this scenario had a small runoff component and the level of drift, being 0,did not contribute towards the EEC, which remained small. Table 8. Estimated environmental concentrationsofzeta-cypermethrin (ppb) in the water column, benthic pore water, and benthic sediment.

Equilibrium Partitioning and Concentration in the SediinentlPore water As mentioned previously, zeta-cypermethrin, like other pyrethroids, is a lipophilic compound that can adsorb readily to particulate and sediment, thus possibly limiting its exposureto aquatic life in the water column but increasing toxic exposure in the benthos. Sediment can act as a reservoir for lipophilic persistent compounds. The sediinent and particulate likely adsorb a high percentage of zeta-cypermethrin TGAI, as indicated by its relatively high Koc. Therefore, coupled with zeta-cypermethrin's persistence in anaerobic environments, sediment bound zeta-cypermethrin TGAI could present a toxicity risk for benthic aquatic life and aquatic ecosystems in general.

Crop Scenario

FL Turf

Therefore, in order to assess this potential for pesticide risk to aquatic benthic systems, the Environmental Fate and Effects Division (EFED) of the Office of Pesticides Program (OPP) has adopted the method used by the Office ofWater that relies on equilibrium partitioning (EqP) of chemicals. The EqP theory is based on the hydrophobicity and concentrations ofthe chemical normalized to organic carbon (OC) in sediment (De Toro et nl. 1991)and holds that a nonionic chemical in sediment partitions between sediment organic carbon, interstitial (pore) water and benthic organisms. At equilibrium, ifthe concentration in any phase is known, then the concentration in the other phases can be predicted. A key component to this theory is the chemicals organic carbon coefficient (Koc), which is constant for everychemical and represents the ratio of the chemical concentration in water to the concentration in organic carbon. The document, 

### "Technical Basis for the Derivation of Equilibrium Partitioning Sediment Guidelines (ESGs) for the Protection of Benthic Organisms: Nonionic Organics" (USEPA, 2000a), demonstrates that biological responses of benthic organisms to nonionic organic chemicals in sediments are different when the sediment concentrations are expressed on a dryweight basis, but similar when expressed on 

### a ug chemicallg organic carbon basis (uglg,,). Similar responses were also observed across sediments when interstitial water concentrations were used to normalize biological availability. TheTechnical Basis Document hrther demonstrates that ifthe toxic effect concentration in water is known (e.g., LC5&the effect concentration in sediment on a uglg,, basis can be predicted by lnultiplying the effect concentration in water by the chemical KO,.

Since, EFED uses a deterministic method for its screening level risk assessment, the calculation ofrisk quotient values (RQ) is important for assessing possible risk. The RQ values are calculated by taking the

A chosen tepresentatlve scenalro fo~ splay appllcatronsofzeta-cypennethr~n to agt~cultural crops " A chosen ~epesenta~~ve scenalro fol g~anuldr appl~catrons of zeta-cypertneth~rn to restdenttal lawns. home per Itnetets, gardens, and ~ndust~ lal non-agncultutal ateas. Media Watet Colu~nn Benth~c Pore Wate~ Benthrc 5edunent 60-day 000215 0 000343

1 94 Peak 0 0405 0 000624

3 53 21-day 0 00403 0 000466

2 64ratio ofthe estimated exposure concentrations (EEC) to the toxicity effect value (e.g., LC50, NOAEC). The EEC values are model generated (e.g., PRZMI EXAMS) and reflect peer evaluated and approved scenarios for assessing pesticide exposure to an aquatic environment. However, the PRZMI EXAMS output produces water column EEC values, as well as sediment andpore water EEC values. Therefore, to assess possible toxic pesticide exposure to aquatic organisms from sediments, EFED is using the PRZMI EXAMSto generate EECs for sediment and pore water model based on the principles ofthe equilibrium partitioning theory. By relying on sediment andlor pore water output values, EFED has two ways for calculating RQ values for sediments by using pore water exposure values and bulk sediment values. The calculationsthat rely on pore water can be calculated by dividing the PRZM/ EXAMS output value for pore water concentrations by the dissolved concentrations in the water column that caused toxicity in bioassays using zeta-cypermethrin TGAI (e.g., LC5o). EEC pore water ugL/ LC50 ugL If sediment effects data are available (LC50 uglkg,,), RQ can be produced by using the PRZMI EXAMS sediment output value for sediment. EEC sediment uglugoc I LC50 ugikg,, In the case of zeta-cypennethrin, toxicity data were available in terms of bulk sediment, but not in terms of pore water concentrations. Subsequently, the equivalent concentrations in pore water were calculated based on the equilibrium partitioning theory and the definition ofthe 

### Kc: K,, (Wkg OC) = Sediment Conc in OC (mg/kgOC) +Conc in pore water (mg/L). Additional details on the equilibrium partitioning theory can be found in Appendix G. b. Aquatic Exposure Monitoring (Field Data) Deposits of cvperinethrin on the surfaceof three streams adjacent to vineyards in France that were sprayed (via mistblowers) with cypermethrin insecticide were in the range of 0.04-0.45 mg/sq m(1); cypermethrin concns in subsurface water of the streams were in the range of 0.4-1.7 ugll soon after spraying, and decreasing to c0.1 ugll within a period of about 5 hours(1). [(I)Crossland NO et al; Aquatic Toxicol 2: 253-70 (1982)-as cited in HSDB] A search was conducted using the USGS National Water QualityAssessment (NAWQA)database ofthe Pesticides National Synthesis Project. It appears that zeta-cypermethrin was not targeted pesticides in this survey. However, a survey of cypermethrin performed in Alabama showed no detections in 13ground water samples from five site, and 26 surface water samples from five sites (at the pglL level). 

### In addition the Pesticides in Ground Water Database (1971-1991) was searched, it reports 311wells sampled for cyper~nethrin only from 1986to 1988in AR, MO, and TX. No detections were reported in any case. Due to the nature of the database, it is not known the limit of detection or the methodology used. 

### 3. Terrestrial Exposure Assessment Terrestrial wildlife exposure estimates are typically calculated for bird and mammals, emphasizing a dietary exposure route for uptake ofpesticide active ingredients. These exposures are considered assurrogates for terrestrial-phase amphibians aswell as reptiles. For exposure to terrestrial organisms, such as birds and small mammals, pesticide residues on food items are estimated, based on the assumption that organisms are exposed to a single pesticide residue in a given exposure scenario. Application methods of zeta-cypermethrin include ground or aerial spray application for agricultural uses, granular application for residential lawn, home perimeter, garden, and industrial non-agricultural uses, and subterranean, barrier, and perimeter treatments for termiticide uses. For this terrestrial exposure assessment, both spray applications and granular applications are considered, as described below.

a. Terrestrial Animal Exposure Modeling- Spray Applications A primary concern with zeta-cypermethrin is that birds and mammals may be exposed shortly after application through oral or dietary exposure to vegetative plant material or insects when foraging in the treated fields for nesting material or food. Therefore, for zeta-cyperrnethrin sprayapplications, estimation ofpesticide concentrations in wildlife food items focuses on quantifying possible dietary ingestion of residues on vegetative matter and insects. The EFED terrestrial exposure model T-REX (T-REX, Version 1.2.3, dated August 8,2005)is used to estimate exposure andrisks in conservative scenariosto avian species for four forage food types and to mammalian species for five forage food types for spray applications of zeta-cypennethrin. Input values for avian and mammalian toxicity as well as chemical application and foliar dissipation half-life data are required to run the model. The model provides estimates of exposure concentrations and risk quotients (RQs). Specifically, the model provides estiinates of concentrations (upper-bound and mean) of chemical residues on the surface of different types of foliage and insects that may be dietary sources of exposure to avian, mammalian, reptilian, or terrestrial-phase amphibian receptors. The surfaceresidue concentration (ppm) is estimated by multiplying the application rate (pounds active ingredient per acre) by a value specific to each food item. These values (termed the Hoerger-Kenaga estimates) along with a more detailed discussion ofthe methodology implemented by TREX, are presented in Appendix C. For multiple applications, the EEC is detennined by adding the mass on the surface iinrnediately following the application to the mass ofthe chemical still present on the surfaces on the dayof application (determined based on first order kinetics using the foliar half-life as the rate constant). For this risk assessment, terrestrial EECs as a result of spray applications of zeta-cypennethrin were estimated using the inaxiinuin proposed application rates, the maximum number of applications, and the minimum application interval for four representative crop uses: stone fruits, canola, non-grass animal feeds, and barley. These usage scenarios (application rate, application interval, and number of applications) were evaluated because they are expected to be representative ofthe exposure to wildlife resulting from the broad range of proposed uses of zeta-cypennethrin. Input values used for estimating avian and mammalian exposure risks to zeta-cypermethrin are summarized in Table 9. The inaximuin number of applicationsper year, the minilnuin application intervals, and the maximuin application rates for each crop scenario were derived from the product labels, whereas the foliar half-life of 11.1 days was based on data for cypermethrin in Willis and McDowe11 (1987). The foliar half-life of 11.1 days represents the 90%upper confidence limit of the mean half-life for all crops that had half-life estimates based on total residues (internal plus dislodgeable residues). Data on all available crops (i.e., cotton and beans) were considered because T-REX is used to calculate terrestrial exposureconcentration estimates on all plant surfaces following pesticide application, and not just concentration estiinates on a particular crop. However, half-lives based on dislodgeable residues alone were not considered for zeta-cypermethrin because the compound (based on cypermethrin's log 

### 16, )has a high log lq,, (6.54) and is expected to bind strongly to plants. Therefore, half-lives based on total residues(i.e., half-lives of 7.9 and 4.8 for cotton and beans, respectively) will likelyprovide more realistic estimates, whereas half-livesbased on dislodgeable residues alone will likely underestimate exposure concentrations. By comparing estimated concentrations to acute and chronic toxicity reference values, acute and chronic RQs are calculated. The EECs on food items may be compared directly with dietary toxicity data or converted to an oral dose. Theresidue concentration can be converted to a daily oral dose based on the fraction ofbody weight consumed daily as estimated through allometric relationships; for both birds and mammals, three weight categories (or sizes) were considered. The screening-level risk assessment for zetacypern~ethrin uses upper-bound predicted residues asthe measure of exposure. Summaries of the predicted residues of zeta-cypermethrin that may be expected to occur on selected avian or mammalian food items immediately following application for representative maximum use scenarios are presented in Table 10. Exposure and risks could be overestimated ifthe actual application rate, frequency of application, or number of applications are lower than the input parameters used for the conservative exposure scenarios that were modeled. On the other hand, terrestrial EECs could be an underestimation of actual exposure concentrations in the environment. Although the label stated that zeta-cypermethrin can be applied via foliar spray applicationup to a maximum of 

### 6 times per season, for this risk assessment, EFED assumed that zeta-cypermethrin was applied at a maximum of 

### 6 times per year. If there are conditions under which there is more than one growing season for a crop within a single year, exposure estimates and risk to terrestrial organisms could be significantly underestimated. Examples of crops that have multiple seasons where this may be a concern include leafy, brassica, and fruiting vegetables in CA, AZ, 

### FL, GA, LA, 

### NC, TX, and/or SC.

Stone Fruits

C'anola

Non-grass Animal Feeds

Barley

"Thishalf-life represents the 90% upper confidence limit of the mean half-life for all crops that had half-life estimates based on total residues (internal plus dislodgeable residues)in Willis and McDowe11 ( 1987). 0.05

0.05

0.05 11.1

11.1

11.1 7

7

14 4

3

5

### b. Terrestrial Animal Exposure Modeling-Granular Applications Stone Fruits

Canola

Non-grass Animal Feeds

Barley

There is potential for exposure of birds and mammals to granular zeta-cypermethrin used on residential lawns, home perimeters, gardens, and industrial non-agricultural areas by direct ingestion of granules. They also may be exposed by other routes, such as incidental ingestion ofcontaminated soil, dermal contact with treated granular surfaces and soil during activities in the treated areas, preening activities, and ingestion of drinking water contaminated with pesticide. It should be noted, however, that theprimary route of exposure to zeta-cypermethrin granules will be via the oral route because it is not volatile and it is not expected to appreciably absorb through the skin. Therefore, ingestion of granules and consumption of terrestrial invertebrates that have bio-concentrated pesticide residues were considered as routes of exposure in this assessment. Although a bird's or mammal's habitat isnot limited to a square foot, there ispresumably a direct correlation between the concentration of a pesticide in the environment (mg/ft2)and the chance that an animal will be exposed to a concentration that could adversely affect its survival. Typically for ground application of granular formulations, acute exposure and risks are estimated with the conceptual approach using the ~~~~/ft' method given in the Tier 1 model T-REX (T-REX, Version 1.2.3, dated August 8, " EEC equivalent dose = tipper-bound Kenega value * (%UWconsumed!100). %UW consumed = 1 14%, 65%, and 29% for small, medium, and large birds, rcspectively. Short grass Tall grass Broadleaflforageplants & s~nall insects F~uits/pods/seedsllatge insects Shott pass Tall grass Broadleaflforageplants & s~nall insects Fmitsipodslseedsilarge insects Sho~t grass Tall grass Broadleaflforage plants & sinall insects Fruitslpodslseedsilargeinsects Shoit grass Tall grass Broadleaflforageplants 61s~nall insects Ruitsipodslseeds!lat.ge insects 3 1 14 18 2 28 13 16 2 25 I I 14 2 20 9 I I 1 I I 5 6 I 10 4 5 1 9 4 5 1 7 3 4 I2005). Terrestrial EECs are calculated based on an estimation of loadings of pesticide per unit area (expressed in terms of mg a.i./ft2), assuming that 100%ofthe application was present on the surface of the soil. This approach compares the availablemass ofpesticide per square foot to the acute oral dose for toxicity 

### (LD50 values adjusted for body weight and percent body weight consumed)to deriverisk quotients (Further description of the mg/ft2 index is provided in Appendix C,U.S. EPA, 2004, and U.S. EPA, 1992). Exposure andrisk resulting from granular applications to turf were evaluated using this method and the input values provided in Table 11. The EECs generated by T-REX represent the application rate (lb a.i./A) expressed in terms of ing a.i./ft2. The EEC for the maximum zeta-cypermethrin granular application scenario was 2.34 mg a.i./ft2.

- - - - - - -- -- - - - -- - - -- -- .- -- - -- - -- 

### -- 11. Input parameters used in T-REX (v1.2.3) to determine terrestrial acute EECs for the application of granular zeta-cypermethrin to turf.

Maxiinuin application rate 

# I Input Variable ParameterValue

Maximuin number of applications per year Minimum application interval


### I Soil 

### 1 Fo~~nulation type: granular 

### 1 Source

Inputs for the LD$,J~~~ Method for Granular Applications to
EFED has no standard methodology for assessing chronic risk to terrestrial organisms from granular applications. The chronic exposure estimation and risk characterization for terrestrial wildlife in this risk assessment considers granular routes of exposure including direct ingestion of soil invertebrates that have bioconcentrated zeta-cypermethrin residues of granules in soil. This estimation of earthworm concentration was calculated using a fugacity-based (equilibrium partitioning) approach based on the work of Trapp and McFarlane (1995) and Mackay and Paterson (1981). Earthworms dwelling within the soil are exposed to contaminants in both soil pore water and via the ingestion of soil (Belfroid et al. 1994). Soil concentrations of zeta-cypennethrin were calculated based on a depth of 7.6 cm (three inches; a chemical concentration averaged over a 7.6-cm soil depth was used to reflect a concentration across the earthworm occupied area of soil), theuse characterization for the application of granular zeta-cypermethrin to turf (a maximum one-time application of 0.225 lb a.i./A), and a I-acre terrestrial environment. The concentrations of zeta-cypennethrin in earthworms were calculated as a combination of uptake from soil pore water and gastrointestinal absorption from ingested soil: 1
NIA
Application method: broadcast

where: Product Label

CSoil s the concentration of chemical in bulk soil (note: a chemical concentration averaged over a 7.6cm soil depth was used to reflect a concentration across the earthworm occupied area of soil) Z,,r,~l,,onl, isthe fugacity capacity of chemical in earthworms = (lipid)(&w)(~eart11won11)lH ZSoil is the fugacity capacity of chemical in soil = (Kd)(psoil)/H Zwater is the fugacity capacity of chemical in water = 1/HCSOil is the concentration of chemical in soil water =Csoil/Kbw Kbwis the bulk soil-to-water partitioning coefficient = (~soil)(Kd)+0 +(~-0)(Kaw) K,, is the air-to-water partitioning coefficient =HIRT 

### H =Henry's Constant specific to zeta-cypennethrin = 3.4E-07 R =universal gas constant, 8.3 1~oules-dlmol-OK 

### T =temperature OK, assumed to be 298 OK Kd= soil partitioning coefficient = 2834= (chemical K,,, )(0.02 assumed fraction of soil organic carbon) psOil =bulk density of soil, assumed to be 1.3g/cm3 0 =volumetric fraction of the soil, assumed to be 

### 0.30 E =volumetric total porosity of the soil, assumed to be 0.50 lipid = fraction of lipid in organism =0.01 (Cobb et al. 1995) 

### k, =zeta-cypermethrin (based on cypermethrin's) octanol to water partitioning coefficient = 3467368.5 

### Pean,lwonn =the density of the organism g/cm3,assumed to be 1 g/cin" Assuming the maximum application rate of zeta-cypermethrin of 0.225 lb a.i./acre to abare, very low density soil (I .3g/cm7)incorporated to 7.6-cm depth, the following soil concentrations can be calculated for a depth of 7.6 an:

. = applicrrtior~ r-ute - - AR x CF, x CF, soil depth x soil density z x CF, x px0,, where, Coil = concentration in soil immediatelyfollowing a single application (mglkg) AR = application rate (lb a.i./acre) 

### z = soil depth (cm) pi = soil bulk density (g/cm7) CFI = conversion factor, 453582.4 mg = 1 lb CF2 = conversion factor, 1acre =40468730 cm' CF3 = conversion factor, 0.001 kg = 1 g Based on this soil concentration calculation of 0.26mglkg, the concentration of zeta-cypermethrin in an earthworm based on the above earthworm fugacity model equation (using the maximum application rate) would be 4.8mg a.i./kg (for detailed calculations, seeAppendix 

### D). Table 12 summarizes the model inputs and exposure estimates (i.e., earthworm concentrations 

### in ppm) for insectivorous birds and mammals, based on a granular zeta-cypermethrin application rate of 0.225 lb a.i./A.

Table 12. Model Input Parametersand Dietary Exposure Estimates for Avian and Mammalian Receptors Parameter 

# I

.I 

# IC,,I,,,.,(mg/kg @ 7 6 cm depth)

Farthworln Concentratlun (~ng'kg) (C,,,, ,,,,,,,,) 026 4 8Chronic risks for birds and inammalsthat consumeterrestrial invertebrates asthe majority of their diet were estimated based on comparison ofthe concentration of zeta-cypermethrin in earthworm tissue (Cearthwonn) with chronic toxicity values for birds and mammals. In addition to dietaryestimates, residue concentrations in terrestrial invertebrates were converted to daily oral doses for mammals based on the fraction of body weight consumed as estimated through mammalian allometric relationships, and were then compared with chronic oral toxicity values for mammals. A detailed description ofthe fugacity model and methodology used to estimate chronic exposure and risk for granular applications of zeta-cypermethrin are presented in greater detail in Appendix 

### D. C. Ecological Effects Characterization 

### In screening-level ecological risk assessments, the effects characterization describes the types of effects a pesticide can have on aquatic or terrestrial organisms. This characterization is based on registrantsubmitted studies that describe information regarding acute and chronic effects toxicity for various aquatic and terrestrial animals. Appendix 

### E summarizes the results of the registrant-submitted toxicity studies used to characterize effects for this risk assessment. It should be noted that ecological toxicity data specific to zeta-cypermethrin is sparse. However, zeta-cypermethrin is a modified form of cypermethrin, and a comparison oftheir respective databases (although it is limited for zeta-cypennethrin) indicates that they have similar toxicityto non-target organisms. Therefore, the Agency has allowed use of the cypermethrin TGAI database to fulfill many registration requirements for zeta-cypermethrin and toxicity data for all cypennethrin products (alpha-,beta-, theta-, and zeta-cypermethrin) are being bridged for risk assessment purposes. Toxicity testing reported in this section doesnot represent all species of birds, mammals, or aquatic organisms. Only a few surrogate species for both freshwater fish and birds are used to represent all freshwater fish (2000+) andbird (680+) species in the United States. For mammals, acute studies are usually limited to the Norway rat or the house mouse. Estuarinelmarine testing is usually limited to a crustacean, a mollusk, and a fish. Also, testing for reptiles and amphibians are not required. Therisk assessment assumes that avian and reptilian toxicities are similar. The same assumption is used for fishand amphibians. 

### In general, categories of acute toxicity ranging from "practically nontoxic" to "very highly toxic" have been established for aquatic organisms (based on LC50values), terrestrial mammals (based on LD50 values), avian species (based on LCs0values), and non-target insects (based on LDsovalues for honey bees) (U.S. EPA 2001). These categories arepresented in Appendix 

### E. 1. Aquatic Effects Characterization Themost sensitive acute and chronic toxicity reference values associated with zeta-cypermethrin (based on data for any of cypermethrin's four different products; alpha-, beta-, theta-, and zeta-cypermethrin) exposure to freshwater and estuarinelmarine species are sumlnarized in Table 13. All toxicity reference values used to assess the potential risks of zeta-cypermethrin exposure are obtained from studiesusing the technical grade ingredient,rather than from studiesusing metabolites or formulated products. A more detailed summary of the aquatic toxicity data available to characterize risks associated with zetacypermethrin applications is given in Appendix E. Results of acute toxicity studies indicate that zeta-cypermethrin can be classified as very highly toxic on an acute basis to freshwater fish, freshwater invertebrates, estuarinelmarine fish, estaurinelmarine invertebrates (shrimp and crustaceans), and benthic organisms. In addition, zeta-cypennethrin can be categorized ashighly toxic to oysters. Acute toxicity studies on the cypermethrin degradate 3- phenoxybenzoic acid in freshwater fish and invertebrates show that the degradate is much less toxic than cypermethrin TGAI. The lowest acute LCSo values reported for freshwater fish and estuarinelrnarine fish range from 0.39 pg a.i./L in rainbow trout to 0.95 pg a.i./L in sheepshead minnow. These results suggest that freshwater and estuarinelmarine fish should have a similar susceptibility to zeta-cypermethrin toxicity. For freshwater and estuarinelmarine invertebrates, the lowest acute LCjovalues range from 0.0036pg a.i./L 

### in amphipods to 0.00475 pg a.i.1L in mysids, approximately 100times lower than the LCjovalues reported for aquatic fish, indicating that aquatic invertebrates are likely to be more sensitive to zeta-cypermethrin toxicity than aquatic vertebrates. Thus, invertebrates are expected to be at a greatest risk for acute effects (lethality). 

### In addition to lethality data, several acutetoxicity studies provide information regarding sub-lethal effects of cypermethrin. For fish, sub-lethal effects include rapid and erratic swimming, partiallcomnplete loss of equilibrium,jaw spasms, gulping respiration, lethargy, and darkened pigmentation. In aquatic invertebrates, sub-lethal effects include lethargy, erratic swimming behavior, loss of equilibrium, surfacing, immobilization, and decreased movement in response to stimulation. In most studies,the acute NOAEC values for sub-lethal effects are approximately 2- to 3-fold lower than the corresponding LCso values, indicating that sub-lethal effects can occur at exposure levels below the concentrations that cause lethality. Calculations for sediment and pore water exposure to benthic organisms followed the equilibrium partitioning model asnoted previously and in Appendix G.The LCjovalues for benthic organisms based on exposure to cypermethrin in bulk sediment and pore water were 3.6pg a.i./kg sediment and 0.00257 pg a.i./L, respectively. Chronic toxicity studies with cypermethrin are available for freshwater fish and estuarinelrnarine invertebrates. Results of these studies suggest that zeta-cypermethrin can be expected to adversely affect neonate survival of freshwater fish and reproduction and growth of estuarinelrnarine invertebrates. No dataare currently available on the chronic effects of zeta-cypermethrin or any other cypermethrin product to benthic organisms, estuarinelmarine fish, or freshwater invertebrates. However, estimates of chronic toxicity to benthic organisins (NOAECs =0.59 ug ailkg sediment and 0.0042 pg a.i./Lpore water), estuarinelinarine fish (NOAEC =0.34 pg a.i./L), and freshwater invertebrates (NOAEC =0.00059 pg a.i./L) were derived to estimaterisk using the inethodology described below. There are no data available on the effects of zeta-cypermethrin to aquatic vascular or non-vascular plants.Table 13. Zeta-cyperrnethrin toxicity reference values (TRVs)for aquatic organisms. Reference Effects Toxicity Reference

Value (pga.i.L) Freshwater Fish Exposure Duration Exposure Scenario Species

MRlD 44546027

MRlD 89039 Molb~d~ty

G~owth and ~no~b~dity LCqI,=O 39yga11L

NOAEC=O 1411gallL LOAFC = 0 33 pg ad1 Acute

C h~on~c

Freshwater 111,ertebrates Ra~nbow t~out (OIILOI II~IIC~IIS n1oX1rs) I-athcadlnlnnow (Plme/~/lole~ promeln Y)

MRlD 44423501 96 houls

30 days

Motb~d~ty LC5,,=00036pga~IL

Ch~on~c Acute

No adequate data suhmltted, to assess chion~c r~sk to freshwater lnverteblates, a sunogate NOAEC value of0 00059 pg a I 'L was dawed based on the acute-to-ch~on~c ratlo method uslng acute and chron~c data for estua~ ~nelmar~ne ~nve~tebrates " Atnph~pod (Hvalella arteca) 96 hou~ s

Bentl~ic Organisn~s MRlD 44074406 Mo~b~d~ty and Glowth Acute

C hton~c No chron~c data subm~tted. to assess ch~on~c r~sk to benth~c organisms. suliogatechronlc NOAEC tox~clty values fol sedumentof 0 59 pg a I /kg sed~ment' and to1 pole watel of 0 00042 pg a I /Ld wwne de~~vedbased on the acute-toch~on~c latlo method uslng acute and ch~on~c data fo~ estua~~neltnar~ne ~vertebtates Amph~pod (Hvolellircrztetcr) 10 dd)s

Estuarine/Marioe Fish Exneinnentdl sed~ment value LC 511 = 3 6 11ga I /kg sednnent I1e1 red note water value1' LC%(, = 0 00257 pg a I iL

Acute

C htonlc Shecp<head lnlnnow (Cvp1 lrlldoll I ur rester)

EstuarineIMarine Invertebrates No datd subm~tted, to assess ch~on~c 11skto estua~~ne~ina~tne fish. a suliogate NOAEC value of 0 34 pg a I /L fol sheepshead rnlnnow was de~~ved based on the acute-to-chtonlc latlo method uslng acute and chion~c data fo~ fieshwate~ fish ' 96 houls

Acute

Ch~on~c LC 

### ,,,=0 95 pg a I IL

Mys~d sh~~mp (Misrdop~rs Bahra) Mysid shninp (MI rrdoprrs Rolrra) Morb~d~ty

96 bouts

28 daysf MRlD 90075

LC;(,=0 00475 pg a I IL

NOAEC =0 00078 1 pg a I IL I OAR = 0 00197 pg a I 11 NOAEC =0 00ISpg a I IL LOAEC = 0 0028 11ga I IL Molhld~ty We~ght of females educed Numbel of offsp~ing Ace No 070562

MRlD 42725301The acute toxicity oftechnical grade cypermethrin to freshwater fish was evaluated in several species, with 96-hour LCs0values ranging from 0.39 pg a.i./Lin rainbow trout (MRID 44546027) to 4.5 pg a.i./L in bluegill sunfish (MRID 44546030). Details of these studies areprovided in Appendix 

### E. Based on these results, zeta-cypermethrin can be categorized asvery highly toxic to freshwater fish on an acute basis. Taking the most conservative approach, the lowest 96-hour LCsoof 0.39 pg a.i./L in rainbow trout isused to evaluate acute toxic exposure of freshwater fish to zeta-cypermethrin. Acute toxicity studies in freshwater fish were also submitted for the cypermethrin degradate 3- phenoxybenzoic acid in rainbow trout (MRID 89037) and bluegill sunfish (MRID 89038). Results yield 96-hour LCSo values of 13.3and 36.3 mg degradatelL in rainbow trout and bluegill sunfish,respectively (details provided in Appendix 

### E). Based on these 96-hour LC50 values, 3-phenoxy benzoic acid is categorized as slightly toxic to freshwater fish on an acutebasis and is much less toxic than cypermethrin TGAI to freshwater fish. No acute toxicity studies with zeta-cypermethrin formulations and freshwater fish were submitted. Freshwater Invertebrates Acute toxicity studies oftechnical grade cypermethrin to freshwater invertebrates yield toxicity values ranging from a 96-hour LC50value of 0.0036 pg a.i./L in Hynlella (MRID 44423501) to a 24-hour LCjo value of >5.0 pg a.i./L in Notonectn, Cl~ironomus tl~ummi, andLymneaperegrn (Acc. No. 070562). Studydetails areprovided in 

### Appendix 

### E. Based on these results, zeta-cypermethrin can be categorized asvery highly toxic on an acute basis. Taking the most conservative approach, the lowest LCso value reported (96- hour LC5o value of 0.0036 yg a.i./L) is used to evaluate acutetoxic exposure of freshwater invertebrates to zeta-cyperinethrin. Acute toxicity tests in freshwater invertebrates using the cyperinethrin degradate 3-phenoxybenzoic acid to daphnids were also submitted. Results yield 48-hour EC50values of 89.0 mg degradatell (MRID 152739) and 1 1 1mg degradatell(Acc. No. 070562). Based on these acutetoxicity values, 3-phenoxy benzoic acid is categorized aspractically non-toxic to slightly toxic to freshwater invertebrates on an acute basis. Thus, the 3-phenoxy benzoic acid degradate is much less toxic than cyperinethrin TGAI to freshwater invertebrates. No acute toxicity studies with zeta-cypermethrin formulations and freshwater invertebrates were submitted. EstuarineIMarineFish The acute toxicity oftechnical grade cypermethrin to estuarinelmarine fish was evaluated in sheepshead minnow and Atlantic salmon, with 96-hour values of0.95 pg a.i./L (MRID 90075) and 3.42 pg a.i./L (MRID 41968212)respectively, indicating that zeta-cypermethrin can be classified asvery highly toxic to estuarinelmarine fish on an acutebasis. Study details are provided in 

### Appendix E. Taking the most conservative approach, the lowest 96-hour LCsovalue of0.95 pg a.i.1L for sheepshead minnow is used to evaluate acute toxic exposure of estuarinelrnarine fish to zeta-cypermethrin. No acute toxicity studies with zeta-cypermethrin formulations or degradates and estuarinelmarine fish were submitted. EstuarineIMarine Invertebrates Acute toxicity tests with estuarinelrnarine invertebrates using the cypermethrin TGAI were conducted with shrimp, inollusks, and crustaceans. Study details are provided in 

### Appendix E. Toxicity values (ECSo and LCS0)reported for shrimp range from the 96-hour LCsovalue of 0.00475 yg a.i.1L (Acc. No. 070562) to the 96-hour LCsovalue of 0.01 pg a.i./L (MRID 41068003). Similar results were observed in lobster (96- hour LC50 =0.04 pg a.i./L;MRID 41068003) and fiddler crab (96-hour LCso= 0.197 pg a.i./L; MRID 89045). Based on these results, zeta-cypermethrin can be categorized as very highly toxic to estuarinelrnarine shrimp and crustaceans. Results of acutetoxicity tests with cypermethrin TGAI and mollusks demonstratethat zeta-cypermethrin can be classified asmoderately to highly toxic to oysters, with a 96-hour ECsovalue of 0.37 mg a.i.iL in Eastern oyster (MRID 89049) and a 48-hour LCSo value of >2.27 mg a.i./L in Pacific oyster (Acc. No. 070562). Results of these studies indicate that it can be expected that mollusks are less susceptible than shrimp and crustaceans to zeta-cypermethrin toxicity on an acute basis. Taking the most conservative approach, the 96-hour LC50 value of 0.00475 pg a.i./Lfor lnysid shrimp will be used to estimate acuterisk to estuarinelmarine invertebrates exposed to zeta-cypermethrin. No acute toxicity studies with zeta-cypermethrin fornlulations or degradates and estuarinelmarine invertebrates were submitted. Benthic Organisms Several studies on the toxicity of cypennethrin TGAI to benthic organisms havebeen submitted; details are summarized in 

### Appendix E. However, studies were conducted using two types of experimentalprotocols, exposure in a water-only system and exposure in a water-sediment system. 

### In the water system studies, organisms were exposed to cypermethrin in overlying (surface) water; no sediment was present in the test chamber. Because the exposure scenario under which the endpointswere derived in the water-only studies were not considered appropriatelrepresentative of that group of organisms, only those studiesthat exposed sediment dwellers to cypermethrin in a water-sediment svstern were considered for determining risk tobenthic organisms. The only two studies that met these criteria were MRID 44074402 and MRID 44074406; MRID 44074402 was conducted with midge while MRID 44074406 was conducted with amphipods. Both studies were conducted using the sameprotocol and sediments from three sources (Florissant, Mississippi, and Duluth). All toxicity values for these studies are expressed in terms of the concentration of cypermethrin in sediment (pg a.i./kg) on Day 0. Results yield 10-dayLC5() values ranging from 3.6 pg a.i./kg sediment (Florrisant sediment) in amphipods to 67 pg a.i./kg sediment in midge (Mississippi sediment). 

### In general, toxicity decreased (asreflected by higher LCj0values), with increasing organic carbon content of the sediment. Taking the most conservative approach, the lowest 10-dayLCsovalue of 3.6 pg a.i./kg sediment in amphipods will be used to estimate the acuterisk of exposure of benthic organisms to zetacypermethrin. Although compounds bound to the sediment present potential toxicity concerns, those residues that have reached equilibrium in thepore water are considered a greater source of toxic risk to benthic invertebrates (Di Toro et nl., 1991).

### In order to assess the risk associated with acute exposure of benthic organisms to zeta-cypermethrin in pore water, the equivalent toxicity value in pore water is derived using the lowest 10- day LCsovalue of 3.6 pg a.i./kg sediment in amphipods as follows. The LCs0value in whole sediment [3.6 pg a.i./kg sediment] is divided by the proportion of organic carbon (OC) in the sediment [0.0099kg OC/kg whole sediinent]. Thus, the LCs0 value in units of OC is 364 pg a.i./kg OC [3.6pg a.i./kg sediment + 0.0099 kg OC/kg sediment]. The equivalent concentration in pore water is based on the equilibrium partitioning theory and the definition ofthe 

### kc: KO,(Llkg OC) = Sediment Conc in OC (mglkg OC) -+ Conc in pore water (mg/L). For cypermethrin,the 

### Kc is taken as 141,700 [Llkg OC] (MRID 42129003). Thus, the calculated concentration in pore water corresponding to the LCSo value of 364 pg a.i./kg OC is 0.00257 pg a.i./L [364 1-18 a.i./kg OC + 141,700L/kg OC]. To assess the risk associated with acute exposure ofbenthic organisms to zeta-cypermethrin in pore water, the derived LCsovalue of 0.00257 pg a.i./L isused. It should be noted that for the above two sediment toxicity studies, cypermethrin was applied to watersediinent systems and allowed to settle for only 2 days, after which organisms were introduced to the water-sediment systems, and toxicity was assessed after a 10-dayexposureperiod. Therefore, these studies present a degree 

### ofuncertainty because ofthe lack of equilibration of spiked sediments with the pore water; measurement of cypennethrin in sediment and surface water on Days 0 and 10of exposure indicates that the water-sediment system was not at equilibrium. Sinceresidues that have reached equilibrium in the pore water are considered a greater source oftoxic risk to benthic invertebrates (Di Toro et 

### nl., 1991),the studies presented in this assessment may underestimate sediment toxicity and equilibration should have occurred for at least one month prior to testing. Although the registrant has conducted new sediment studies in order to address this uncertainty, the studies are currently in review and have not been included in this risk assessment. No tests on the toxicity of zeta-cypermethrin degradates to freshwater benthic organisms were submitted. ii. Chronic Effects Freshwater Fish An early life-stage study in fathead minnow was submitted by the registrant to establish the chronictoxicity of cypennethrin to freshwater fish (MRID 89039);data are summarized in Appendix 

### E. Results of this 30-day exposure study show that survival was significantly reduced compared to controls at 0.33 pg a.i./L, yielding a 30-day NOAEC value for survival of 0.14 pg a.i./L. No treatment-related effects were observed for hatchability or growth. The NOAEC value for survival of 0.14 pg a.i./L will be used to assess the risk of chronic exposure of freshwater fish to zeta-cypermethrin. No chronic toxicity studieswith zetacypermethrin degradates and freshwater fish were submitted. Freshwater Invertebrates No valid chronic toxicity studies with zeta-cypermethrin and freshwater invertebrates were submitted. However, a chronic NOAEC was estimated for freshwater invertebrates based on the acute-to-chronic ratio method, determined by the following mathelllaticalrelationship: Estuarinelmarineinvertebrate LC5()(0.00475 pg a.i.1L) IEstuarinelmarine invertebrate NOAEC (0.000781 pg a.i.1L) =Freshwater invertebrate LCso(0.0036 pg a.i./L)/ 

### X (estimated value for Freshwater invertebrate NOAEC), where 

### X =0.00059 pg a.i./L. To assess the risk to freshwater invertebrates as a result of chronic exposure to zeta-cypermethrin, the estimated NOAEC for freshwater invertebrates of 0.00059 pg a.i./L is used. No chronic toxicity studies with zeta-cypermethrin degradates and freshwater invertebrates were submitted. EstuarineIMarine Fish No valid chronic toxicity studies with zeta-cypennethrin and estuarinelmarine fish were submitted. However, a chronic NOAEC was estimated for estuarinelmarine fish based on the acute-to-chronic ratio method, determinedby the following mathematical relationship: Freshwater fish LC5,](0.39 pg a.i./L) IFreshwater fish NOAEC (0.14 pg a.i./L) = EstuarinelMarine fish LCso(0.95pg a.i.1L)l X (estimated value for EstuarineIMarine fish NOAEC), where X =0.34 pg a.i./L. To assess the risk to estuarinelmarinefish as a result of chronic exposure to zeta-cypermethrin, the estimated NOAEC for estuarinelmarine invertebrates of 0.34 pg a.i.iL isused. No chronic toxicity studies with zeta-cypermethrin degradates and estuarinelmarine fish were submitted. Estuarinehlarine Invertebrates Three studies involving life-cycle tests in mysid shrimp were submitted by theregistrant to establish the chronic toxicity of cypermethrin to estuarinelmarine invertebrates; data are summarized in Appendix E. TheNOAEC values reported in these studies range from 0.78 1 ng a.i./L for effects on first generation mortality, male length and weight and female weight (MRID 42725301), to 1.5ng a.i./L for number of offspring (Acc. No. 070562) and survival and reproduction (MRID 44546035). Taking the most conservative approach, the lowest NOAEC value of 0.781 ng a.i.1Lwill be used to assess the risk of chronic exposure of estuarinelmarine fish to zeta-cypennethrin. No chronic toxicity studieswith zetacypermethrin degradates and estuarinelmarine invertebrates were submitted. Benthic Orrranisms Although theregistrant has conducted chronic sediment studies with cypermethrin, the studies are currently in review and have not been included in this risk assessment. However, chronic NOAECs based on sediment and pore water concentrations were estimated for benthic organisms based on the acute-tochronic ratio method. The chronic NOAEC estimated for benthic organisms in terms of pg a.i./kgsediment was determined by the following mathematical relationship: Estuarinelmarineinvertebrate LCs0(0.00475 pg a.i.1L) I Estuarinelmarine invertebrate NOAEC (0.000781 pg a.i./L) =Benthic LC5o in sediment 3.6 yg a.i.1kg sediment 1

### X (estimated benthic NOAEC value in sediment), where X =0.59 pg a.i./kgsediment. The chronic NOAEC estimated for benthic organisms in units of yg a.i./kg pore water is based on the acute-to-chronic ratio method, determined by the following mathematical relationship: Estuarinelmarineinvertebrate LCso(0.00475 pg a.i.1L) 1Estuarinelmarine invertebrate NOAEC (0.000781 pg a.i.1L) =Benthic LCsoin pore water (0.00257 pg a.i./L 1

### X (estimatedbenthic NOAEC value in pore water ), where 

### X =0.00042 yg a.i.1L. To assess the risk to benthic organisms as a result of chronic exposure to zeta-cypermethrin, the estimated NOAEC values of 0.59 yg a.i.1kgsediment and 0.00042 yg a.i.1Lpore water are used. No chronic toxicity studies with zeta-cypermethrin degradates and benthic organisms were submitted. iii. Sub-lethal Effects Freshwater Fish In addition to lethality endpoints, sub-lethal effects of acute cypermethrin (TGAI) exposure were assessed in studies in rainbow trout and bluegill sunfish. Studydetails areprovided in Appendix E. The sub-lethal signs of toxicity includerapid and erratic swimming, partiallcomplete loss of equilibrium, jaw spasms, gulping respiration, lethargy, and darkened pigmentation. The acuteNOAEC values for sub-lethal effects ranged from 0.1 1 pg a.i./Lin rainbow trout (MRID 44546027) to 2.1 pg a.i./L in bluegill sunfish (MRID 44546030). Results of a chronic toxicity study in fathead minnow report that no significant treatment-related effects on hatchability or growth were observed during a 30-day exposure to technical grade cypermethrin (MRID 89039). Thus, no sub-lethal effects were observed at concentrations up to 0.33 yg a.i./L, the highest dose tested. Freshwater Invertebrates The sub-lethal effects of acute cypermethrin (TGAI) exposure were assessed in studies in waterflea. Study details areprovided in Appendix E. The sub-lethal signs of toxicity include immobilization and decreased movement in response to stimulation. Acute NOAEC values for sub-lethal effects range from 0.085 yg a.i./L (MRID 44546032) to 0.14 yg a.i.1L (MRID 44546031). EstuarineIMarineFish Sub-lethal effects of acute cypermethrin exposure in estuarinelmarine fish (loss of equilibrium and lethargy) were reported in two studies of sheepshead minnow (Appendix E). Acute NOAEC values for sub-lethal effectsranged from 0.84 yg a.i.1L (MRID 44546034) to 1.4pg a.i./L (MRID 44546033) and are approximately 2- to 3-fold lower than the corresponding LCSo values of 2.7 and 2.4 pg a.i./L, respectively. EstuarineIMarineInvertebrates Sub-lethal effects (lethargy, erratic swimming behavior, loss of equilibrium, and surfacing) of cypermethrin TGAI in estuarinelmarine invertebrates were reported in two studies of mysid shrimp (AppendixE). Acute NOAEC values for sub-lethal effects range from 1.7ng a.i.1L (MRID 445612 10)to2.3 ng a.i./L (MRID44561209) and are approximately 2- to 3-fold lower than the corresponding LC50 values of 5.5 and 5.9 ng a.i./L,respectively. Results of chronic toxicity studies in mysid shrimp show that exposure to technical grade cypermethrin had adverse effects on reproductive and growth parameters; study details areprovided in Appendix E. For decreased number of young, a chronic NOAEC value of 1.5ng a.i./L was reported in two studies (Acc. No. 070562, MRID 44546035). For decreased growth and length, the chronic NOAEC value reported is 0.781 ng a.i./L (MRID42725301). Benthic Organisms Acute toxicity tests using the water-sediment system (Appendix E)report decreased growth (length and dry weight) in both ainphipod (MRID 44074406) and midge (MRID 44074402). Acute NOAEC values range from <1.8 yg a.i./kg sediment in amphipod (Florrisant sediment) and 25 pg a.i./kgsediment in midge (Mississippi sediment). Acute toxicity studies in benthic organisms using the water-only system did not specificallyreport sub-lethal effects resulting from cypennethrin exposure. iv

# . Field Studies No field studies on the effects of zeta-cypermethrin on aquatic organisms were submitted. b. Plants Inhabiting Aquatic Areas No data were availableto evaluate the risk of zeta-cypermethrin exposure to aquatic plants; however, EFED isnot concerned because zeta-cypemethrin's neural toxic mode of action is not expected to induce phytotoxic effects. In addition,based on the lack of studies demonstrating adverse effects of zetacypennethrin or any other pyrethroid to plants, and the fact that no incident reports have reliably linked zeta-cypermethrin or any other compound in the synthetic pyrethroid class of chemicals to phytotoxic effects despite being applied on or near agricultural plants, it appearsunlikely that zeta-cypermethrin poses a phytotoxic concern. Therefore, Tier 

### I aquatic plant growth studies with algae (Guideline 122-2)and duckweed (Guideline 123-2) are in reserve and are not being requested at this time. 

### 2. Terrestrial Effects Characterization Themost sensitive acute and chronic toxicity reference values associated with zeta-cypermethrin (based on data for any of cypermethrin's four different products; alpha-,beta-, theta-, and zeta-cypermethrin) exposure to mammals and birds are summarized in Table 14. All toxicity reference values used to assess the potential risks of zeta-cypermethrin exposure are obtained from studies using the technical grade ingredient, rather than from studies using metabolites or formulated products. A more detailed sulnmaryof the terrestrial toxicity data availableto characterize risks associated with zeta-cypermethrin applications is given in Appendix 

### E. Based on the results of acute oral and acute dietary avian toxicity studies with cypennethrin, zeta-cypermethrin can be categorized aspractically non-toxic and slightly toxic, respectively. 

### In mammals, results of acute exposure studies indicate that zeta-cypermethrin is moderately toxic. Results of availabletoxicity studieswith cypennethrin indicate that zeta-cypermethrin can be classified ashighly toxic to honey bees and very toxic to earthworms on an acute contact basis. Thus, honey bees and non-target insects are expected to be the species at risk for acute effects (lethality). Although there is a concern for chronicrisk to mammals based on parental toxicity and toxicity to offspring (decreased body weight and body weight gain) in the available rat reproduction studies,cypermethrin exposure does not appear to induce adverse chronic effects 

### in birds and zeta-cypermethrin is not expected to pose a risk to this taxonomic group. Currently, there areno data available regarding the effects of zeta-cypennethrin degradates to any terrestrial organism or the effects of zeta-cypermethrinto terrestrial plants.

a. Terrestrial Animals reproduction study offspring) = 100ppm (5 mg/kg/day) I,OAEC = (toxicity to parents and offspring) = 500 ppm (25ing/kg/day) Birds

1. Acute Effects Birds Acute toxicity studies on technical grade cypennethrin have been conducted with bobwhite quail and MRID 9007 1

MRlD 44546024

MRlD 90073 and MRlD 90074 a LCsl, >2,634 lng a.i.ikg diet

LDc1, >2,000 mg a.i./kgbody wt

NOAEC = 50 ppm LOAEC > 50 ppln 5-day dieta~y

Single oral dose

Reproduction study Acute

Acute

Chronic

Non-Target Terrestrial Invertebrates Mallard duck (Atlas plo~r.l~v~tchos) Bobwhite quail (Co1i11r1.s virginionus) Mallard duck and Bobwhite quail(Anos pla~~~rl~vnclios and Colin~ts ~,ii.ginion~rs)

Acc. No. 260647

Acc. No. 260647

Roberts and Dorough 1984 LD5,,=0.023 pg a.i./bee
LDq,=0.172 pg a.i./bee
L('sI,= 26.09~1glcni~ 48-Hour acute contact toxicity test 48-Hour acute oral toxicity test 48-Hour acute contact toxicity test Acute

Acute

Acute Honey bee

, 

### yo Honey bee (Apisn~ellifir.cr) Earthwor~n (Eisenio,foetido)mallard ducks; results are summarized in Appendix 

### E. Results ofthe acute oral toxicity studies in mallard ducks (Acc. No. 241598) and bobwhite quail (MRID 44546024) yield LDSo values for cypermethrin of >9,520 and >2,000 mg a.i./kg body weight, respectively, indicating that zeta cypermethrin can be classified aspractically non-toxic to birds on an acute oral basis. Results of acute dietary toxicity studies in mallard ducks and bobwhite quail yield LCSo values for cypermethrin ranging from>2,634mg a.i./kgdiet in mallard ducks (MRID 9007 1)to >5,290 mg a.i./kg diet in mallard ducks (MRID 44546025) and bobwhite quail (MRID 44546026), indicating that zeta-cypermethrin can be categorized aspractically non-toxic to slightly toxic on an acute dietary basis. To assess acute risk of zeta-cypennethrin to birds, the lowest acute oral LD50 value of >2,000 mg a.i./kgbody weight and the lowest acute dietary LCso value of >2,634mg a.i./kgdiet areused. No acute toxicity studies with zeta-cypermethrin formulations or degradates and avian species were submitted. Mammals Results of an acute oral toxicity study in rats yield LDSO values for cypermethrin TGAI of 247 mg a.i./kg body wt in lnales and 309 mg a.i./kg body weight in females (MRID 00056800). Results of an acute oral toxicity study in rats yield LDsovalues for zeta-cypermethrin TGAI of 134mg a.i./kg body 

### wt in males and 86 mg a.i./kgbody weight in females (MRID 417761 15). Studydetails areprovided in Appendix E. Based on these results, zeta-cypennethrin TGAI is classified asmoderately toxic to mammals. The lowest oral LDSo of 86 mg a.i./kg body weight is used to assess acuterisk in mammals. No acute toxicity studies with zeta-cypermethrin formulations or degradates and mammalian species were submitted. Non-Target Terrestrial Invertebrates Although EFED does not assess risks to non-target terrestrial invertebrates, results of an acute contact study in honey bees using technical grade cypermethrin yield a 48-hour LDSO value of0.023 ug a.i./bee, categorizing cypermethrin and zeta-cypennethrin ashighly toxic to honey bees (Acc. No. 260647). Results are summarized in Appendix 

### E. In an oral exposure study 

### in honey bees, a LDS0 value of 0.172 ug a.i./bee was reported (Acc. No. 260647). An acute contact study in earthworms was identified from an open literature study (Roberts and Dorough 1984;Appendix 

### E). Results ofthis study yield a 48-hour contact LCSo value of 26.09 ug a.i./cm2for cypermethrin applied to filter paper, categorizing cypennethrin and zeta-cypermethrin as very toxic to earthworms. No acute toxicity studies with zeta-cypermethrin degradates and terrestrial invertebrates were submitted. ii. Chronic Effects Birds One-generation reproductive studies were submitted for mallard ducks (MRID 90073) and bobwhite quail (MRID 90074). Results ofboth studies show no treatment-related effects on adults, reproductive parameters, or offspring, as a result of cypermethrin exposure at dietary concentrations up to 50mg a.i./kg diet (thehighest concentration tested). To assess chronic risk to avian species, the lowest NOAEC value of 50 mg a.i./kg diet is used. Details are summarized in Appendix E.No chronic toxicity studies with zeta-cypermethrin formulations or degradates and avian species were submitted. Mammals Results of 2- and 3-generation reproduction studies in rats show that exposure to technical grade cypermethrin (MRIDs 001 12912,42068504,9202704,and 00090040) and zeta-cypermethrin (MRID 41968204) results in decreased body weight and decreased body weight gain in both adults and offspring, with NOAECs ranging from 100mg a.i.1kgdiet (equivalent to 5 mg a.i./kgbody weight/day) (MRID 00090040) to 150mg a.i./kg diet (equivalent to 7.5 mg a.i./kg body weightlday) (MRIDs 001 12912, 42068504, 9202704). No other significant treatment-related effects on reproductive parameters were reported in these studies. To assess chronic risk to mammalian species,the lowest NOAEC value of 100 mg a.i.1kgdiet (equivalent to 5 mg a.i./kg body weightlday) is used. Details are summarized in Appendix E. No chronic toxicity studies with zeta-cypermethrin formulations or degradates and mammalian species were submitted. Non-Target Terrestrial Invertebrates No chronic toxicity studies with the TGAI, formulation, or degradates of any cypermethrin product (alpha-, beta-, theta-, and zeta-cypermethrin) and non-target terrestrial invertebrates were available for this assessment. iii. Sub-lethal Effects Birds Acute toxicity studies in birds report aversion to feed containing cypermethrin at concentrations greater than approximately 2,000 mg a.i./kg diet (MRIDs 44546025,44546026, 90072, and 90071). In addition, reductions in body weight, which may havebeen caused by aversion to feed, were reported, with NOAEC values ranging from 1290to 2550 mg a.i.1kgdiet (MRDs44546025 and 44546026). No other gross pathological findings, clinical signs of toxicity, or adverse effects on reproductive parameters or offspring were reported in the submitted acute and chronic toxicity studies in avian species. Mammals Exposure of rats to a single dose of cypennethrin produced clinical signs of neurotoxicity and abnormal gait. Results of chronic toxicity studies show that exposure to technical grade cypermethrin and zetacyperinethrin results in decreased body weight and decreased body weight gain in both adults and offspring, with NOAELs ranging from 100mg a.i./kg diet (equivalent to 

### 5 mg a.i./kgbody weightiday) (MRID 00090040) to 150mg a.i./kgdiet (equivalent to 7.5 mg a.i./kg body weightlday) (MRIDs 001 12912, 42068504, 9202704). Other sub-lethal effects include signs of emaciation, ataxia, increased sensitivity to sound, increased relative brain weight, chromodacryorrhea, chromorhinorrhea, softlliquid stools, decreased food consumption, and high stepping gait (MRIDs 00112912,42068504, 9202704, and 41968204). No other significant treatment-related effects on reproductive parameters were reported in these studies. Terrestrial Invertebrates No information on sub-lethal effects of zeta-cypermethrin on terrestrial invertebrates was reported in the available studies in honey bees and earthworms. iv. Field StudiesNo field studies on the effects of zeta-cypermethrin on terrestrial organisms were submitted. b. TerrestrialPlants No data were availableto evaluate the risk of zeta-cypermethrin exposure to non-target terrestrial plants; however, EFED is not concerned because zeta-cypermethrin's neural toxic mode of action is not expected to induce phytotoxic effects. 

### In addition,based on the lack of studies demonstrating adverse effects of zetacypermethrin or any other pyrethroid to plants, and the fact that no incident reports have reliably linked zeta-cypermethrin or any other compound in the synthetic pyrethroid class ofchemicalsto phytotoxic effects despite being applied on or near agricultural plants, it appears unlikely that zeta-cypermethrin poses a phytotoxic concern. Therefore, Tier 

### I plant studies [Guideline 122-1 (a) Seedling Emergence and Guideline 122-1(b) Vegetative Vigor] are in reserve and are not being requested at this time. IV. Risk Characterization Risk characterization is the integration of exposure and effects characterization to determine the ecological risk from the use of zeta-cyperinethrin and the likelihood of effects on aquatic life and wildlife based on varying pesticide-use scenarios. Therisk characterization provides an estimation and a description ofthe risk; articulatesrisk assessment assumptions, limitations, and uncertainties; synthesizes an overall conclusion; and provides the risk managers with information to make regulatory decisions. A. RiskEstimation 

## - Integration of Exposure and Effects Data Results ofthe exposure and toxicity effects data are used to evaluate the likelihood of adverse ecological effects on non-target species. For the assessment of zeta-cypennethrin risks, the risk quotient (RQ)method is used to compare exposure and measured toxicity values (Appendix F). Estimated environmental concentrations (EECs) are divided by acute and chronic toxicity values. Theresulting RQs are then compared to the Agency's levels of concern (LOCs). These LOCs, summarized in Appendix F, are the Agency's interpretivepolicy used to analyze potential risk to non-target organisms and the need to consider regulatory action. These criteria are used to indicate when a pesticide's use as directed on the label has the potential to cause adverse effects on non-target organisms. For non-target aquatic animals (i.e.,fish and invertebrates), surface water, pore water, and sediment EECs were obtained from the Tier 2 model PRZMIEXAMS. For non-target terrestrial animals 

### (i.e.,birds and mammals), EECs and RQs were obtained from T-REX (Appendix C). Toxicity reference values for aquatic and terrestrial organisms exposed to zeta-cypermethrin are summarized in Table 13 and Table 14,respectively. 1. Non-Target Aquatic Animals and Plants To assess risks of zeta-cypermethrin to non-target aquatic animals 

### (i.e., fish and invertebrates), surface water, pore water, and sediment EECs were obtained from the Tier I1model PRZMIEXAMS (Table8). ThePRZMIEXAMS model was run using the following four representative scenarios: California grapes, Georgia peaches, Pennsylvania apples, and Florida turf. All of the scenarios except the Florida turf scenario represent proposed spray applications of zeta-cypermethrin; the Florida turf scenario was used to estimate EECs for granular applications of zeta-cyperinethrin to residential lawns, home perimeters, gardens, and other industrial non-agricultural areas. EFED uses the peak concentration to derive RQs for acute exposure. The 21-day average concentration and the 60-day average concentrations to derive chronic RQs for invertebrates (including benthic organisms) and fish,respectively. To evaluatethepotential fortoxic risk from zeta-cypermethrin exposure in the water column, EFED divided the water column EEC by an effects endpoint (LC5o, ECso,orNOAEC) from water column toxicity studies to generate acute and chronic RQ values. The evaluation oftoxic risk to benthic organisms was approached by assuming equilibrium partitioning of a high 

### &, coinpound like zeta-cypermethrin between the sediment and thepore water (i.e.,the water found between particulates 

### in the sediment). Risk to the benthos was assessed using two approaches: (1) EECs for sediment were model-generated (PRZMIEXAMS) and compared to the toxicity value asreported for sediment exposure (LCSO) from the available toxicity studies with watersediment systems; and (2) EECs for pore water were model-generated (PRZMIEXAMS) and compared to a derived toxicity value for pore water (based on the sediment exposure toxicity value). Sinceresults of acute toxicity studies in freshwater fish and invertebrates (See Appendix E)indicate that the major cypermethrin degradate (3-phenoxy benzoic acid) is much less toxic than theparent compound, EECs and RQs were derived only for the parent compound, not for total residue (parent plus degradates). The major biodegradation transformation products: 3-PBA, cis- and trans-DCVA and 3- phenoxybenzaldehyde, arethe result of the cleavage of the ester moiety of the parent compound.

a. Water Column Exposure

# - Acute and ChronicRisk Acute RQs for aquatic animals are suminarized in Table 15. Based on the toxicity data for all cypennethrin products (alpha-, beta-, theta-, and zeta-cypermethrin), there is potential for acute risk to nontarget listed and non-listed freshwater and estuarinelmarine fish and invertebrates resulting from both granular and spray applications of zeta-cyperinethrin. The LOC for acuterestricted use (LOC 0.1) is exceeded for all aquatic animals and modeled crop scenarios, except for estuarinelmarine fish under the CA grapes and FLturf scenarios (RQs = 0.09 and 0.04, respectively). As discussed previously (Ecological Effects Characterization section), based on a comparison of acute 

### LC5() values, invertebrates appear to be the most sensitive aquatic animals, and RQs for invertebrates are much higher than those derived for fish. Thehighest acute RQs are observed for freshwater invertebrates, ranging from 11.25 (FL turf) to 404.44 (PA apples), greatly exceeding all acute LOCs. Acute RQ values derived for estuarineimarine invertebrates also greatly exceed acute LOCs, with RQ values ranging from 8.53 (FL turf)to 306.53 (PA apples). Because acute toxicity values for freshwater and estuarinelmarine fish are similar in magnitude, the ranges of acute RQs for these taxonomic groups are also similar (0.10 to 3.73 for freshwater fish and 0.04 to 1.53for estuarinelmarinefish). For all aquatic animal species, the highest acute RQs are observed for the PA apples scenario, and the lowest acute RQs are observed for the FL turf scenario. Thistrend reflects the sametrend of the values ofthe EECs (Table S),which areused in the calculation ofthe RQs. Chronic RQs for aquatic animals are summarized 

### in Table 16. As anticipated based on a comparison of the chronic NOAEC values, chronic RQs derived for aquatic invertebrates are much higher than those derived for fish, and exceed the chronic LOC (1) in all instances. Chronic RQs exceed the chronic LOC (LOC 

### I)by factorsranging from 5 to 156 and from 7 to 207 for estuarinelmarine and freshwater invertebrates,respectively. The chronic RQs for fish do not exceed the chronic LOC for any ofthe crop scenarios considered in this assessment; RQs range from 0.02 to 0.46 and from <0.01 to 0.19for freshwater and estuarinelmarine fish,respectively. Due to chronic toxicity data gaps for freshwater invertebrates and estuarinelmarine fish, there is uncertainty regarding the magnitude of chronic risk estimates for these taxonomic groups because RQs are based on estimated chronic toxicity values (detailed description provided in Ecological Effects Characterization section). For all aquatic animal species, the highest chronic RQs are observed for the PA apples scenario, and the lowest chronic RQs are observed for the FL turf scenario.Table 15. Acute RQs for freshwaterand estuarinelmarinefish and invertebratesexposed to zetacypermethrin 

## .'

b. Sediment Exposure 

### - Acute and Chronic Risk Table 16. ChronicRQs for freshwaterand estuarinelmarinefish and invertebrates exposed to zetacypermethrin

# .'

Acute and chronic RQs have been derived for exposure of benthic organisms via sediment and pore water (Table 17). All acute (RQ ranges = 2.51 to 3 1.08and 0.78 to 7.78 for sediment and pore water, respectively) and chronic (RQ ranges = 13.20to 165.90 and 2.38 to 40.48 for sediment and pore water, respectively) RQs for benthic organisms exceed the LOCs for acuterisk (LOC 0.5), acute restricted use (LOC 0.1), acute endangered species (LOC 0.05) and chronic risk (LOC 1)for all spray application scenarios. For granular applications (FL turf), all sediment RQs for benthic organisms exceed the LOCs for acute risk (LOC 0.5), acute restricted use (LOC 0.l),acute endangered species (LOC 0.05) and chronic risk (LOC 1)(Acute and chronic RQs =0.98 and 4.47, respectively); however, pore water RQs for benthic organisms only exceed the LOCs for acuterestricted use (LOC 0.

### I), acute endangered species (LOC 0.05), and chronic risk (LOC 1)(Acute and chronic RQs = 0.24 and 1.11,respectively). Higher RQs were EstuarineIMarine Invertebrate

Acute RQ

17.68 " ' " 42.32 "'

### " 306.53 "' * 8.53 h'"

a RQs = EEC/LC 50, whe~e EEC s atethe peak concenhattons In su~face wate~ generated from PRZMiEXAMS for the vartous crop scenattos constdeled, and acute tox~c~ty refe~ence values ateas follows freshwatet fish, ta~nbow ttout 96-hr LC<,] =0 39 pg a I IL. freshwater ~nvertebrates. amph~pod 96-h~ LC',,] =0 0036 pg a I /I
.estoartneln~ar~ne f~cli. sheepshead mlnnou 96-hout I C<,, =0 95 pg a I IL. and estuarlneimar~ne ~nvet-teblates, mystd sh~~tnp 96-hout LCqo =0 00475 pg a I /L I' RQc meet 01 exceed LOC fot acute 11sk(LO< 0 5) 'RQs meet 01exceed LO(' fo~ acute ~estllcted use (LOC 0 I ) " RQs meet 01 exceed 1OC fot acute endange~ed specles (LOC'0 05) EstuarinetMarine Fish Acute RQ 0.09 0.21 ' " 1.53~'"

0 04

EstuarineIMarine Invertebrate Chronic RQ 19.21 " 24.97' 156.21 5.16' Crop Use

GIapes Peaches Apples

Turf

" RQs = FFC 'NOAFC, where the ch~on~c EECs fo~ tnvetteb~ates and fish atethe 21day and the 60-day average concenhatlons In surfacewater genetated from I'RZMIEXAMF fo~ the vanous clop scenallos, respect~vely, and chronlc toxtc~ty reference values are as follows freshwater fish, fathead mlnnow 30-da) NOAEC =0 14 pg a I IL, fresli\cater Invertebrates, estnnated chron~c NOAEC =0 00059 pg a I /L, estuarttie/mar~ne fish. estnnated chron~c NOAEC =0 34 pg a I /L, and estuar~nel~nartne tnvettebtates, mystd shrnnp 28-day NOAEC =0 000781 pg a I /L Detatls for all estnnated ch~on~c toxtc~ty values ateprov~ded In the FcologtcalEffects Chatacta~zat~on sectlon h~Qs exceed LOCs fot chton~c nsk (I0C' 1) Crop Use

gtapes pcaches apples

tutt Freshwater Fish Acute RQ 0.22 ' " 0.52 ' 3.73 " ' 0.10 '" PRZMJEXAMS Scenario

CA gtapes (;A peaches I'A apples

FL turf

Freshwater Invertebrate Chronic RQ 25.42" 33.05" 206.78"

6.83 Freshwater Invertebrate

Acute RQ

23.33 "' 55.83 "' 404.44 ' " 11.25""

EstuarineAMarine Fish Chronic RQ 0 03 0 04 0 19 <0 01 PRZMIEXAMS Scenario

CA grapes GApeaches PA apples

FL tu~f Freshwater Fish Chronic RQ 0 08 0 09 0 46 0 02observed in the acute and chronic values derived from the sediment EECs than from the pore water EECs in all scenarios.

c. Aquatic Plants

Table 17. Acute and chronic RQs for benthic organismsexposed to zeta-cypermethrin.

Toxicity data on the effects of zeta-cyper~nethrin on non-target aquatic plants are currently unavailable; thus RQs cannot be derived. Crop Use

grapes peaches apples

tulf

2. Non-Target Terrestrial Animals The EFED terrestrial exposure model T-REX (v 1.2.3)was used to estimate exposure and risks in conservative scenariosto avian species for four forage food types and to mammalian species for five forage food types for spray applications of zeta-cypermethrin as described in the Exposure Characterization. For this risk assessment, terrestrial EECs as a result of spray applications of zeta-cypermethrin were estimated using the maxilnuln proposed application rates, the maximum number of applications, and the minimum application interval for four representative crop uses: stone fruits, canola, non-grass animal feeds, and barley. Risk quotients were calculated using upper-bound EECs. For birds, acute RQs were derived using dietary-based and dose-based acute toxicity values, and chronic RQs were derived using a dietary-based chronic toxicity value. For mammals, acute RQs were derived using a dose-based acutetoxicity value, and chronic RQs were derived using 

### a dietary-based chronic toxicity value and a calculated dose-based chronic toxicity value (as determined using the standard FDA lab rat conversion in T-REX). Dietary-based RQs were calculated using EECs expressed in terms of residue concentration for the various forage categories, and toxicity values (LCs0or NOAEC) are expressed in units of dietary concentration. Dose-based RQs

' Sedltnent acute RQs = EECi LCV,. whe~e EFCs alethepeak concentratlon In sed~ment generated fiom PRZMiFXAMS forthe vallouc clop scenatlos, and acutetoxlc~ty ~efe~ence value IS the alnphlpod 10-dayLC ,,, = 3 6 pg a I kg sedlment "porewatel acute RQs = EECi LCII,, where CEC s alethe peak concentlat~on In pole watel t~oln PRZMIEXAMSfo~ the varlous clop scenarios, and estllnated acute LC$(, =0 00257 pg a I /L. pore water (detalls for estimatedtoxlclty value aleplov~ded mthe tcological Effects Cha~acte~lrat~on section) ' Sedllnent ch~onlc RQs = EECINOAEC ,whe~e EEC s arethe 21-day avaageconcentratlon In sedltnent fioln PRZM'EXAMS for the vallous crop scenarios, and estlniated chron~c NOAEC =0 59 pg a I 'kg sed~ment (deta~ls for estllnatedtoxlclty value alep~ov~ded the Ecolog~cal Effects Chalactnlratlon sect~on) " Pole watel ch~onlc RQs = EECINOAEC, whe~e EFCs atethe 21-day avetdge concentratlon In pole water fiom PRZMIEXAMS fo~ the vallous crop scenallos,and estnnated chronlc NOAI-C =0 00042 pg a I IL pore water (detalls for estllnatedtoxiclty value aleprov~ded In the Ecological Eftec& Cha~actalzatlon section) All RQs exceed LOC s 101acute 11sk (1OC 0 5). acute lest~~cted use (LO( 0 1). acute endangeled specles (LOC0 05),and chronlc tlsk (LOC 1) 'RQs meet 01exceed LOC for acute 11sk(LOC 0 5) "Qs meet 01exceed LO( to1 acutelest1lcted use (LO( 0 1)

RQs meet ol exceed LOC tor acute endange~ed species (LOC 0 05) 'RQs exceed IBCsto1 chron~c 11sk(LOC 1 ) PRZMIEXAMS Scenario CA glapes GApeaches PA apples

FL tulf Sediment Acute RQ " 2.51"~ 4.00'" 31.08"~ 0.98" Pore Water Acute RQ 0.78" 0.99 7.78'" 0.24 ' Sediment chronicRQ ' 13.20' 21.69' 165.90' 4.47' Pore Water Chronic RQ 2.38' 5.36' 40.48' 1.11'were calculated using a body weight-adjusted LD50and consumption-weighted equivalent dose sorted by food source and body size. For both birds and mammals, three weight categories (or sizes) were considered. For granular applications of zeta-cypermethrin, acute exposure and risks were estimated with the conceptual approach using the ~~~~/ft~ method given in the Tier 

### 1 model T-REX (T-REX, Version 1.2.3). Terrestrial EEC values were calculated based on an estimation of loadings ofpesticideper unit area. By comparing the available mass of pesticide per square foot to the acute oral dose for toxicity (LD5o),an acute oral RQ was calculated that could be compared to the Agency's LOCs. Terrestrial chronic exposure estimates and risks for granular applications of zeta-cypennethrin were derived using a fugacity-based (equilibrium partitioning) approach that focuses on direct ingestion of soil invertebratesthat havebioaccumulated zeta-cypermethrin residues of granules in soil. This methodology is discussed in greater detail in the Exposure Characterization and Appendix 

### D.

a. SprayApplications: Acute Risk to Birds and Mammals Dietary-based and dose-based acute RQs for birds are summarized in Table 18 and Table 19,respectively. All dose-based (RQs 

### 5 0.02 for all crop use scenarios) and dietary-based (RQs 5 0.01 for all crop use scenarios) avian acute RQs are below the LOCs for acuterisk (LOC 0.5), acuterestricted use (LOC 0.2), and acute endangered species (LOC 0.1). 

### In addition, acuteRQs are less than the reported value for birds, since the available acute toxicity studies did not establish definitive acuteLCs0or LDS0 values (toxicity values are reported as "greater than" the highest doselconcentration tested). However, since all avian acute RQs are well below LOCs for acuterisks, this uncertainty does not affect the acute avian risk characterization. Dose-based acute RQs for mammals are summarized in Table 20. No acute dose-based RQs for any size ofmammals under any crop scenario exceed the LOC for acuterisk (LOC 0.5) or acuterestricted use (LOC 0.2). However, for 15gand 35g mammals that consume short grass exposed to zeta-cypennethrin TGAI via spray applications (RQsrange from 0.05 to 0.16 for all sizes of mammals feeding on short grass under all crop use scenarios), dose-based acute RQs exceed the LOCs for acute endangered species (LOC O.l)(Table20). None ofthe RQs for 1OOOg mammals feeding on any dietary item exceed any of the acute LOCs, and all RQs for mammals feeding strictly on tall grass, broadleaf plantslsmall insects, fruitslpodsllarge insects, or seeds arebelow the acute LOCs.

Table 18. Avian dietary-based acute" and chronic" RQvaIuesforproposed uses ofzeta-cypermethrin based on uwer-bound Kenaga residues on short grass, tall grass, broadleafplants/smallinsects, and fruits/pods/seeds/largeinsects as calculated by T-REX (v1.2.3).

Crop Use

Stone Ftu~ts Maximum Application Rate in Ibs. a.i./A (no. of applications, interval in days) 0 05 Food Items

Short grass Acute RQ

0 01 ChronicRQ '

0 63Table 19. Avian dose-based acute RQ valuesafor proposed uses of zeta-cypermethrin based on uDaerbound Kenaga residues on short grass, tall grass, broadleaf plants/small insects, and fruits/pods/seedsAarge insects ascalculated by T-REX (v1.2.3). I I I Table 18. Avian dietary-based acute' and chronicb 

### v value sf or proposed uses of zeta-cypermethrin based on u~~er-bound Kenaga residues on short grass, tall grass, broadleaf plantslsmall insects, and

Chronic RQ'

0 29 0 35 0 04 0 56 0 26 0 31 0 03 0 50 0 23 0 28 0 03 0 41 0 19 0 23 0 03 (mga I kgdlet) fruits/pods/seedsilarge

Crop Use

Canola

Non-@ass Anlmal Feeds

Barley

" Acute dletaly-based

CropUse genelated from T-RFX and the toxlclty value ISthe acute dletaly-based LC'sl,>2,634 tng a I /kg dlet In lnalla~d duck "Chronlc dletaty-based RQ = tFC/NOAFC, where FEC values ateuppel-bound resldues explessed as dletaly concentlatlons (mga I kgdlet) genelated tiom 1-RFX and the toxrclty value 1sthe chronlc dletaly NOAFC value of 50 Ing a I /kg dlet In bobwhlte qua11and mallald ducks 'All RQs alebelow the I OC fol acute rlsk (LO( 0 5).acute lestllcted use (10C0 2),and acute endangered specles (1.OC 0 I ) 

### " All acutc RQs ale <the lepolted value because the non-defin~tlve LC,(,value of >2,634 mg a I /kg dlet was used to estlmate tisk All RQs alebelow the LOC fol chlonlc IISL (LOC 1) insects as Maximum Application Rate in Ibs. a.i./A (no. of applications, interval in days) (6 17)

0 05 (417)

0 05 (317)

0 05 (51 14)

RQ = EECILCS~,, whele

Maximum Application Ratein Ibs. a.i./A (no. of applications,

interval in days) calculated by T-REX (v1.2.3).

Food Items

Tall glass B~oadleaf plantsls~nall nsects Fmlts, pods, seeds, and lalge Insects Sholt glass rail glass Bloddleafplants/stna~~ lnsects Fruits, pods, seeds, and large Insects Sholt glass 7all grass B~oadleaf plantstslnall insects Frults,pods, seeds, and lalge Insects Short grass Tall glass B~oadleaf plantsls~nall nsects Fruits, pods, seeds, and lalge Insects EEC values are upper-boundresldues expressed

~~d~ Weight (g) AcuteRQc~d

0 01 0 01 <O 01 0 01 1001 0 01 <O 01 0 01 <O 01 0 01 <O 01 0 01 <O 01 <O 01 <O 01 as d~etary concentrations

Avian Acute Risk ~uotients""
Short Grass Tall Grass Broadleaf Plants/Small Insects FruitslPods/ Seeds/ Large InsectsTable 18. Avian dietary-based acuteaand chronicb RQvaluesfor proposed uses of zeta-cypermethrin based on uwwer-bound Kenaga residues on short grass, tall grass, broadleaf plantslsmall insects, and fruitslpodslseedsllarge insects ascalculated by T-REX (v1.2.3).

Crop Use Maximum Application Rate in Ibs. a.i./A (no. of applications, interval in days) Food Items

Stone F~ults

Canola

Non-gass Annnal Feeds

Barley 0 05 (6 7)

0 05 (417)

0 05 (3 17)

0 05 (5 1 14) 20 loo 1000 20 100 1000 20 100 1000 20 100 1000 AcuteRQGd

a Acute dose-based RQ = EECILD~II, where EEC generated fioln T-REX and the tox~c~ty value ISthe acute dose-based LD5(, >2,000 mg a I /kg body we~ght In bobwhite qua11 I' All RQs are below the LOC for acute r~sk (IOC 0 S),acute restricted use (LOC 0 2), and acute endangered specles (LOC 0 I) All acute RQFale <the leported value because the non-definlt~ve LCro value of >2,000 tng a i /kgbody we~ght was used to estnnate 11sk
Table 20. Mammalian dose-based acuteRQvaluesafor proposed uses of zeta-cypermethrin based on uwwer-bound Kenaga residues on short grass, tall grass, broadleaf plantslsmall insects, and fruits/podslseedsllarge insects as calculated by T-REX (v1.2.3). Chronic RQ'

values are uppel-bound lesldues explessed as equ~valent dose (mga I kg body we~ght) 0 02 0 01
<o Ol 0 02 0 01
<o Ol 0 02 0 01
<o 01 0 02 0 01
<o 01

CropUse

Stone Fru~ts

-. c anola 0 01 0 01
<o 01 0 01
<o 01
<o 01 0 01 <O 01
<o 01 0 01 <O 01
<o 01

Maximum Application Rate in Ibs. a.i./A (no. of applications,

interval in days)
0 05 (6 17)
0 05 0 01 0 01
<o 01 0 01 0 01
<o 01 001 <O 01
<o Ol 0 01 <O Ol
<o 01

Body Weight (g)

15 35 1000

15 <o 01
<o 01 <O 01
<o 01
<o 01
<o 01 1001 <O 01
<o 01
<o 01 <O 01
<o 01

Mammalian Acute Risk Quotients

Grass

0.16~ 0.14h 0 07 0.14O Tall Grass

0 07 0 06 0 03 0 06 Small Insects

0 09 0 08 0 04 0 08 FruitstPods / Large Insects

0 01 0.01 <O 01 0 01 Seeds

<O 01 <0.01 <O 01 <O 01Table 18. Avian dietary-based acutea and chronicb RQvaluesfor proposed uses of zeta-cypermethrin based on upper-bound Kenaga residues on short grass, tau grass, broadleaf plants/smaUinsects, and fruitslpodslseedsllarge insects ascalculated by T-REX (v1.2.3).

Crop Use 

## I interval in days) 

# I (4: 7)

Non-grass

Animal 

# 1
005 (317) Feeds Maximum Application Rate in Ibs. a.i.1A (no. of applications,

Barley 35

15 3 5

Table 21. Mammalian dose-based chronic RQvaluesa for proposed uses of zeta-cypermethrin based on upper-bound Kenaga residues on short grass, tall grass, broadleaf plantslsmall insects, and Food Items

"cute dose-based KQ = EE(I':LDi(,, where EEC values are upper-bound residues expressed as equivalent dose (mga.i./kgbody weight) generated l?om T-REX and the toxicity value is the acute dose-based LDco= 86mg a.i./kg body weight in female rats. " RQs meet 01. exceed the LOC for acute endangered species (LOC 0.1). 0.05 (5 114)

fruits/pods/seeds/large

Crop Use

\tone Ftults

Canola
Non-grass

Animal I I I I 0.12"

O.lZh 0.1I AcuteRQGd

1000 I5 35 1000

insects Maximum Application Ratein Ibs. a.i.1A (no. of applications,

interval in days)

0 05 (6 17)

0 05 (417)
0 05 (3

## ' 7) Chronic RQ'

0 06

0.06 0.05 0.06 0.10" 0.09 0.05

as calculated

Body Weight (g)

15 3 5 1000 15 3 5 1000 15 3 5 0 07

0.07 0.06 0.03 0.05 0.04 0.02

by T-REX (v1.2.3). 0 01

0.01 0.01

Short Grass

2.73 " 2.33

### " 1.25I' 2.43I' 2.07 I' 1.1I I' 2.15" 1.83I' <O 01

40.01 <0.01 0.03 0.06 0.05 0.03

Mammalian

Tall Grass

1.25 I' 1.07 I' 0 57 1.11~' 0 95 0 51 0 98 0 84 <0.01 0.01 0.01 <0.01 10.01 <0.01 <0.01 <0.01

Chronic

Broad1eaf

Plants1 Small Insects

1.53I' 1.31" 0 70 1.37 " 1.17" 0 63 1.21 1.03 " Risk Quotients

FruitsIPods 1Large Insects

0 17 0 15 0 08 0 15 0 13 0 07 0.13 0 11 Seeds

0 04 0 03 0 02 0 03 0 03 0 02 0 03 0 03Table 18. Avian dietary-based acuteaand chronicb 

### valuesf sf or proposed uses of zeta-cypermethrin based on u~~er-bound Kenaga residues on short grass, tall grass, broadleaf plants/small insects, and fruits/pods/seeds/large insects ascalculated by T-REX (v1.2.3). I I I I

Table 22. Mammalian dietary-based chronicRQvalues a for proposed uses of zeta-cypermethrin based on u~~er-bound Kenaga residues on short grass, tall grass, broadleaf plants/small insects, and

. fruits/pods/seeds/large insects ascalculated by T-REX (v1.2.3). I I CropUse

Non-grass Animal 0.05 Feeds 

# I (317) 

# I 0.25 

# 1 0.1 1 

# 1 0.14 

# 1 0.02 

# 1 Maximum Application Rate in Ibs. a.i./A (no. of applications, interval in days)

CropUse

Stone Frutts

C anola

I I I I I I>iet:ir).-h;csedKO?; .- Ll:( U( )At (',w hz1.c I.l.('?; \sluts arc upper hound residues exprezsed as d~eta~v concentrations (~np a i ,kgd1e0 reeds

Bal ley



### - - generated fi-omT-REX and the toxicity value is the chronic diet& NOAEC value of 100mg a.i./kg diet in rats. " All KQs arebelow the LOC' for chronic risk (L.OC I ). Food Items

Maximum Application Rate in lbs. a.i./A (no. of applications,

interval in days)

0 05 (6 ' 7) 0 05 14 i 7)

b. SprayApplications: ChronicRisk to Birds andMammals aC hlonlc dose-based RQ = EFC'INOAEL, whe~e EtC values are uppel-bound tesldues expressed as equivalent dose (mga I /kg body welght) generated fiom T-REX and the chron~c toxlclty\slue IS the chronlc NOAFL = 5 mg a I /kgbody welght In rats. converted from the NOAEC of 100mg a I )kgdiet In the lat uslng the standard FDA lab rat conversion by T-REX I' RQs meet or exceed the LOC for chtonlc I ~sh (LOC I) Acute RQG"

0 01 0 02 0 02 0 01 0 05 (5 14)

Mammalian Chronic Risk Quotients Chronic RQ '

Short Grass

0 31
0 28 1000

15 3 5

Tall Grass

0 14
0 13 0 98 1.76" 1.51 I' 1000 I 0 81

P1antslSmal' Insects

0 18
0 16 0 45 0 81 0 69

Fruits/Pods/Seeds/ Large Insects

0 02
0 02 0 37 0 55 0 99 0 85 0 06 0 I1 0 09 0 45 0 05All chronic RQs for birds arebelow the LOC for chronic risk (LOC l)(Table 

### 18). Chronic RQs for birds range from 0.03 (birds feeding on fruitslpodsllarge insects for application of zeta-cypermethrin to barley) to 0.63 (birds feeding on short grass for application of zeta-cypermethrin to stone fruits). Dietary-based chronic RQs for mammals range from 0.01 (mammals feeding on fruits/pods/large insects for zeta-cypermethrin use on barley) to 0.31(mammals feeding on short grass for zeta-cypermethrin use on stone fruits), with no RQs exceedingthe chronic LOC (Table 22). Dose-based chronic RQs for mammals are summarized in Table 21. Dose-based chronic RQs exceed the LOC for chronic risk (LOC 1) for all modeled crop uses for exposure via short grass; RQs range from 0.81 (1000g mammals for zeta-cypermethrin use on barley) to 2.73 (15 g mammals for zeta-cypermethrin use stone fruits). For mammals feeding on tall grass, dose-based chronic RQsrange from 0.37 (1000 gram mammals for zeta-cyperinethrin use on barley) to 1.25 (15 gram mammals for zeta-cypermethrin use on stone fruits); chronic RQs exceed the chronic LOC for the stone fruits (RQ range =0.57 to 1.25)and canola (RQ range =0.5 1to 1.11) scenarios, but not for the non-grass animal feeds (RQ range =0.45 to 0.98) or barley scenarios (RQ range =0.37 to 0.81). For mammals feeding onbroadleaf plantslinsects, dose-based chronic RQs range from 0.45 (1000 gram mammals for zeta-cypennethrin use on barley) to 1.53(15 gram mammals for zeta-cypermethrin use on stone fruits); chronic RQs exceed the chronic LOC for the stone fruits (RQ range =0.70 to 1.53),canola (RQ range =0.63 to 1.37),and non-grass animal feeds (RQ range =0.55 to 1.21)scenarios, but not for the barley scenario (RQrange =0.45 to 0.99). All RQs for mammals feeding on fruits/pods/large insects and seeds arebelow the chronic LOC.

c. Granular Applications: Acute and Chronic Risk to Birds and Mammals Acute RQs (~~~~lft' values) for birds and mammals exposed to zeta-cypermethrin as a granular application are summarized in Table 23. Although none ofthe acute LOCs are exceeded for avian species of any size, acute RQs suggest that granular applications of zeta-cyperinethrin may pose an acute risk to 15gand 35g mammals; the RQ for 15gmammals (RQ=0.83) exceedsthe LOCs for acuterisk (LOC 0.5), acute restricted use (LOC 0.2), and acute endangered species (LOC 0.I), while the RQ for 35g mammals (RQ=0.44) exceeds the LOCs for acuterestricted use (LOC 0.2) and acute endangered species (LOC 0.1). For larger mammals (1000 g), the acute RQ (RQ=0.04) is below all acute LOCs. Terrestrial chronic exposure estimates and risks for granular applications of zeta-cypennethrin were derived according to the methodology presented in Appendix 

### D. Chronic risks to birds and malnlnals associated with ingestion of earthworms that have bioaccumulated zeta-cypermethrin granules are not expected based on a comparison of the estimated earthworm residue (4.8mg a.i.ikg diet) with the avian and mammalian chronic dietary endpoints (50 and 100mg a.i./kg diet, respectively); RQs are less than the chronic risk LOC (1). 

### In addition,based on a comparison of estimated chronic doses for insectivorous mammals and adjusted NOAELs for three size classes, chronic risk resulting from exposure to granular zeta-cypermethrin appears unlikely; chronic RQ values ranged from 0.19 for 1000gmammals to 0.41 for 15gmammals (Table 24).
Table 23. Acute RQ values (~~~dft') for birds and mammalsfor the proposed granular uses ofzetacypermethrinas calculated by T-REX (v1.2.3). I 

# I Crop Use 

# / Maximum 

# I Birds 

# I Mammals 

# I

### 3. Non-target Plants Inhabiting Terrestrial and Semi-Aquatic Areas No toxicity data on the effects of zeta-cypennethrin on non-target terrestrial plants and terrestrial plants in semi-aquatic areas plants are available; thus RQs cannot be derived. Mammalian Acute RQ"

(IJD,dftf)

0.83 '*
0.44 '"
0 04

B. Risk Description - Mammalian Weight fg) 15 35 1000

Although the label stated that zeta-cypermethrin emulsifiable concentrate formulations can be applied up to a nlaximum of 0.3 lb a.i./A per season, for this risk assessment, EFED assumed that zeta-cypermethrin was applied at a maximum of 0.3 lb a.i./A per year for spray applications. 

### Ifthere are conditions under which there is more than one growing season for a crop within a single year, exposure estimates and risk to aquatic and terrestrial organisms could be significantly underestimated. However, despite this possibility, the Agency has still identified acuterisk concerns to fish, aquatic invertebrates (benthic and water columndwelling), terrestrial invertebrates, and mammals, and chronic risk to aquatic invertebrates (benthic and water column-dwelling)based on the proposed use patterns and the fate and toxicity databases for all cypermethrin products (alpha-, beta-, theta-, and zeta-cypennethrin). This concern includes risk to listed and non-listed fish, aquatic crustaceans, snails, clams, amphibians, mammals, and terrestrial invertebrates. Turf

' RQ =ulb a I /A) x (I aclel43.560 sauare feet) x (453.590 nlellbU [(LDSO 1ng1kg) x (we~ght of anunal (kg))] " RQs meet 01 exceed the LOC fol acute r~sk (RQ305) " RQs meet 01 exceed the LOC for restr~cted use (LOC 0.2) " RQs meet 01 exceed thc LOC fol acuteendangered specles (l OC 0 1 )
Table 24. Dose-basedchronic RQsfor insectivorousmammals for the proposed granularuses of zeta-cypermethrin.

For spray applications of zeta-cypermethrin, there is acuterisk to all aquatic invertebrates and fish, and chronic risk to all aquatic invertebrates. For granular applications, there is acute risk to freshwater fish and all aquatic invertebrates, and chronic risk to aquatic invertebrates. 0 225 (IINA) Avian Body Weight (g) 20 100 1000 - - Avian AcuteRQ'Body

(LD,,Jft2) 0 08 0 01 <0 01

Body Weight (g)

15 35 1000 " Dose-adjusted EFCw = Dletaly FEC, (ppm)* (%BWconsu1ned/100) " Adjusted NOAI-L = NOAEL (TWIAW)"~' 'Chlon~c RQ = Dose-adjusted EEC, / Adjusted NOAEL " All RQs alebelow the LOC for chronlc rlsk (LOC I ) AdjustedNOAEL (mglkg-BW~day)~ 1099 8.89 3 85 Dose-adjustedEEC,,

(mglkg-BWIday)" 4.56 3 17 0 72 ChronicRQcd

0 41 0 36 0 19Although this compound binds readily to particulate and organic carbon in the water column (average 

### I&,

= 141,700LIKE),possibly limiting bioavailability in this media after 24 to 48 hours, the bound residues settle onto the benthos, increasing zeta-cypermethrin concentrations in the sediment. Zeta-cypermethrin is expected to be relatively stable to breakdown from sunlight (aqueous photolysis half-life of approximately 36 days and a dark control corrected soil photolysis half-life of over 100days) and biodegrade slowlywith a half-life of about 2 months in aerobic and anaerobic soils. Therefore the sediment compartment can serve as a repository ofpesticide residues that can result in a direct toxic risk concern for benthic and epibenthic aquatic organisms (e.g.early life stage of many invertebrates and fish, as well as crabs and shrimp). The cypennethrin data pertaining to sediment toxicity shows that zeta-cypermethrin can be expected to be potentially very highly toxic and biologically available. Therefore, coupled with its persistence and toxicity profile, sediment bound zeta-cypennethrin from both granular and spray applications presents a potential for direct acute and chronic toxic risk to aquatic life in the benthos and a potential indirect sub-lethal risk to fish through food chain alterations that can affect freshwater and estuarine fish year classes. Relative to the proposed use patterns identified in this assessment, acute and chronic risk to avian species is not expected for spray or granular applications of zeta-cypermethrin. However, exposure of mammals to zeta-cypermethrin spray applications is expected to result in acuterisk to listed species, and chronic risk to listed and non-listed species, while exposure of mammals to zeta-cypermethrin granular applications is expected to result in acuterisk to both listed and non-listed species. Chronic risks to birds and mammals associated with ingestion of earthworms that have bioaccu~nulated zeta-cyperrnethrin granules are not expected. Although EFED doesnot quantitatively estimate risk to non-target terrestrial invertebrates, a qualitative analysis of the available information leads to concern for the potential for risk to listed and nonlisted terrestrial invertebrates, such ashoney bees and earthworms. Results of acute toxicity studies in freshwater fish and invertebrates indicate that the zeta-cypermethrin degradate 3-phenoxy benzoic acid is much less toxic than the parent compound. No information is available on the toxicity of other zeta-cypermethrin degradates or on the toxicity of any degradate to terrestrial organisms; therefore, risk resulting from exposure to zeta-cypermethrin degradates could not be evaluated in this assessment. However, based on the assumption that cleavage of the ester bond moiety in theparent structure results in biologically inactive degradates, these compounds should not present a significantrisk to non-target organisms. It is assumed for pesticides, such as zeta-cypermethrin, which may have residential outdoor uses (applications to home lawns, gardens, parks or tenniticide uses applied subterranean or for perimeter treatment, etc), that runoff water from rain and/or lawn watering may remove pesticide to storm sewers and then directly to surface water. However, 

### in general, outdoor residential uses are comprised of multiple, relatively small, temporally and spatially variable applications that are not simulated 

### in agricultural models. Therefore, there is some uncertainty in the aquatic exposure assessment because a model specifically aimed at simulating pesticide fate and transport in a complex urban landscape has not yet been developed to generate exposure estimates strictly for urban areas. 1. Risks to Aquatic Organisms This risk assessment of zeta-cypennethrin shows that aquatic systems arepotentially at risk from acute and chronic toxic exposure to this chemical. Evaluation of this risk to aquatic organisms was approached by dividing the aquatic system into two general compartments, the water column and thebenthos. The first compartment, the water column, which is defined asthe aquatic areabetween surface and the benthos (approximately 6 inches above the bottom) represents an area where organisms are free-swimmingand can feed and breed at the surface, mid water andlor on the benthos (sediment). Direct pesticidal contact (e.g., gill lamella, ingestion, and integument) to these organisms is assumed to be from the surface water via drift andlor runoff. The toxicity assessment points are the acuteLCs0/EC50 and chronic NOAEC that are generated through standard water column toxicity tests. The second aquatic compartment to be considered is the benthos, which is composed of sediments and an area 6 inches above the sediment (epibenthos). Thebenthos is composed of a diversity of aquatic invertebrates (e.g.,insect larvae, crustaceans, mollusks) and species of fish (e.g., catfish, loachs), as well as certain critical life stages of organisms that reside in the water column; the benthos is also the initial breeding strata and nursery area for several species of fish, especially commercial species such as salmonids. The benthos can also be a source of food items for several species of fish that are actively feeding on the organisms in the sediment andlor capturing organisms that are emerging from this area.

a. Aquatic Animals: Water Column Exposure Sincezeta-cypermethrin can be classified asvery highly toxic on an acutebasis to freshwater (lowest LCj"

= 0.39 pg a.i./L) and estuarinelmarine fish (lowest LC50 = 0.95 pg a.i./L) and freshwater (lowest LC5"= 0.0036 pg a.i./L) and estuarinelmarine (lowest LCjo= 0.00475 pg a.i./L) invertebrates (Table 13),the potential for risk to aquatic systems was anticipated. Results of this assessment show that PRZMIEXAMS modeled surfacewater concentrations resulting from drift and runoff from agricultural areas pose acuterisk to listed andnon-listed fish and invertebrates (freshwater and estuarinelrnarine), and chronicrisk to freshwater and estuarinelrnarine invertebrates. As shown in Table 15,all acute RQs (for all spray and granular scenarios considered) exceed the acuterisk, acuterestricted use, and acute endangered species LOCs for all aquatic invertebrates, and the risk appears to be several orders ofmagnitude greater than the potential risk to fish. This was an expected outcome of this risk analysis, based on comparison oftoxicity values for aquatic animals. However, there is still potential for acute risk to fish, as acute RQs exceed the acute risk, acute restricted use, and acute endangered species LOCs for the most conservative spray application crop scenario considered (PA apples). For granular applications (FL turf scenario), the acute RQ exceeds the acuterestricted use and acute endangered species LOCs for freshwater fish,but there are no exceedances of acute LOCs for estuarinelmarine fish. Based on the available toxicity data (the lowest LCS~IEC~~ for all aquatic water column dwelling organisms; 0.0036 pg a.i./L), it is expected that a peak surface water EEC less than 0.00018 pg a.i.1Lwould be sufficiently low to achieve acute RQ values for all aquatic water colurnn-dwelling organisms that are less than the endangered species LOC (0.05). This means that thehighest peak water coluinn EEC of 1.456pg a.i.lL would have to be reduced by -100%. Results of this risk analysis identify the potential for acuterisks to aquatic animals based on measures of acute lethality, and indicate that zeta-cypermethrin exposure has the potential to reduce survival of aquatic animal populations. However, in addition to acute lethality, results of acutetoxicity studies in fish and invertebrates show that sub-lethal effects can occur at zeta-cypermethrin concentrations 2-3 times lower than corresponding acute LCjovalues. Development of these sub-lethal effects, which include erratic swimming,partiallcomplete loss of equilibrium, immobility, lethargy, and darkened pigmentation, is likely to leave fish and invertebrates more vulnerable to predation pressure, resulting in indirect effects on survival of aquatic populations (Hill 

### et al., 1973; Sousa, 1998). Sub-lethal effects and subsequent indirect effects on population survival are anticipated to occur at concentrations lower than those triggering acute risks to aquatic animals. Results of an early-life stage study in freshwater fish show that long-term exposure to zeta-cypermethrin at a level half of the magnitude of the most sensitive acutetoxicity endpoints for the taxonomic group cansignificantly reduce larval survival. 

### In addition, results of mysid life-cycle studies show that long-term exposure to zeta-cypermethrin at a concentration about one-third ofthe magnitude of the acute toxicity endpoints for the taxonomic group can significantly reduce growth and offspring survival. However, as shown in Table 16,results ofthis assessment show that the chronic LOC is exceeded for all aquatic invertebrates under every scenario considered, whereas there areno exceedancesfor freshwater or estuarinelmarine fish under any scenario. Based on the available toxicity data (the lowest NOAEC for aquatic water column dwelling organisms; 0.00059 pg a.i./L), it is expected that a 21 -day surfacewater EEC less than 0.00059 pg a.i./Lwould be sufficiently low to achieve chronic RQ values for all aquatic water column dwelling organisms that are less than the chronic LOC (1). This means that the highest 21

## - day surface water EEC of 0.122 pg a.i./Lwould have to bereduced by -99.5%. One important point regarding the estimated chronic risk to freshwater invertebrates and estuarine!marine fish is that despite the absence of data on the chronic effects of zeta-cypermethrin on these taxonomic groups, EFED assumed that there are physiological similarities (e.g., developmental, reproduction, etc.) between freshwater invertebrates and estuarinelmarine invertebrates, and between freshwater fish and estuarinelmarine fish. In addition, asnoted by scientists in EFED, the ratio between acute and chronic toxicity values can be expected to vary dependingupon the pesticide, but typically within a median ratio range of 5 

### - 25 (Brian Montegue,personal comnzt~nicntion). Based on assumed physiological similarities and correlationsbetween acute and chronic toxicity values, EFED extrapolated NOAEC values for freshwater invertebrates and estuarinelmarine fish by using the acute-to-chronic ratio method described in the Ecological Effects Characterization section of the assessment. This extrapolation method consists of applylng the lowest observed similar species' acute and chronic effects values as a ratio (e.g., LCS0/NOAEC) to a similar relationship in another aquatic group (e.g., freshwater fish vs. estuarinelmarine fish and fieshwater invertebrates vs. estuarinelmarine invertebrates). Therefore, there isuncertainty regarding estimates of chronic risk for freshwater invertebrates and estuarinelmarine fish dwelling in the water columnn. b. Aquatic Animals: Sediment Exposure Risk estimates for benthic organisms show that zeta-cypennethrin poses acute and chronic risks to benthic organisms, based on acute and chronic RQs calculated using both sediment and pore water EECs (Table 17). However, it should be noted that there are uncertainties regarding acute and chronic risk estimates for benthic organisms. First, the acuteLC,,,value for pore water and the chronic NOAECs for sediment and pore water that were used to generate RQs were not determined in controlled laboratory studies. Rather, acute RQs for pore water were derived using a toxicity value estimated with the Equilibrium Partitioning Theory and the definition of the 

### Km, and the chronic RQs for sediment and pore water were generated based on NOAECs calculated using the acute-to-chronic ratio method (details provided in the Ecological Effects Characterization section and the previous section entitled, Aquatic Animals: Water Column Exposure). Second, the acute sediment toxicity value (in terms ofwhole sediment) used to estimate risk and to generate acute pore water and chronic pore water and sediment toxicity values was obtained from a study using a water-sediment system that was not at equilibrium; sediment concentrations decreased throughout the exposure period. Sinceresidues that have reached equilibrium in the pore water are considered a greater source oftoxic risk to benthic invertebrates (Di Toro et nl., 1991),the studies presented in this assessment may underestimate sediment toxicity and equilibration should have occurred for at least one month prior to testing. Ifthe exposure system had been at equilibrium, it is likely that the acute and chronic toxicity reference values for sediment and pore water would be lower, resulting in RQs that arehigher than those derived in this assessment. However, even with these uncertainties, there are acute and chronic risks to benthic organisms for all modeled crop uses. EFED also realizes that there is uncertainty regarding the amount of sorbed pesticide that may contribute to the toxicity of organisms, that the model-generated pore water values may be an overestimation or underestimation of actual exposure values noted in the laboratory or field, and that inherent variations in biological uptake asresult of differences in feeding pathways (Landrum, et. al., 1994;McGroddy et al., 1996;Bott and Standley2000), organism life stage (Leppanen and Kukkonen 1998),and population-level effects versus individual responses (Hallam et al., 1990)could affect the toxicity of sorbed pesticide to benthic organisms. Although theregistrant has conducted acute and chronic sediment studies with cypermethrin to address some of the current uncertainties associated with risk to benthic organisms exposed to zeta-cypermethrin, the studies are currently in review and have not been included in this risk assessment. Based on the availabletoxicity data (the lowest LCSo for benthic organisms; 0.00257 pg a.i./L pore water and 3.6 pg a.i./kg sediment), it is expected that a peak pore water EEC less than 0.000129 pg a.i./Lpore water and a peak sediment EEC less than 0.18 pg a.i./kgsediment would be sufficiently low to achieve acute RQ values for all benthic organisms that are less than the endangered species LOC (0.05). This means that the highest peak pore water and sediment EECs of0.02 pg a.i./Lpore water and 111.9pg a.i./kg sediment, respectively, would have to be reduced by -99.4% and 99.8%, respectively. Based on the available toxicity data (the lowestNOAEC for benthic organisms of0.00042 pg a.i./L pore water and 0.59 pg a.i./kg sediment), it is expected that a 21-day pore water EEC of approximately 0.00041 ppb and a 21-day sediment EEC of 0.58 pg a.i./kg sediment would be sufficiently low to achieve chronic RQ values for all benthic organisms that are less than the chronic LOC (1). This means that the highest 21

### - daypore water and sediment EECs of 0.017pg a.i./L pore water and 80.3 pg a.i./kg sediment, respectively, would have to be reduced by -97.6% and 99.3%,respectively.

c. Aquatic Plants Toxicity data arenot available to evaluate the risk of zeta-cypermethrin exposure to non-target plants inhabiting aquatic environments;however, EFED is not concerned about the level of phytotoxicity of zetacypermethrin products because zeta-cypermethrin's neural toxic mode of action is not expected to be a phytotoxic concern. 

### In addition,based on the lack of studies demonstrating adverse effects of zetacypermethrin or any other pyrethroid to plants, and the fact that no incident reports have reliably linked zeta-cypermethrin or any other compound in the synthetic pyrethroid class ofchemicalsto phytotoxic effects in algae or aquatic macrophytes, it appears unlikely that zeta-cypermethrin poses a phytotoxic concern. d. Summary ofRisk to Aquatic Systems The complexities ofnatural aquatic systeins forgoes the use of a single factor approach in evaluating even a screening-level assessment ofrisk to fish and aquatic invertebrates from toxic exposure to zetacypermethrin. Thus, EFED approached the zeta-cypermethrin evaluation by assessing the potential toxic impact to the aquatic system from exposure in the water column and in sediment andpore water. As noted earlier, EFED modeled the possible exposure of zeta-cypermethrin use from the proposed use areas for application to grapes, peaches, apples, and turf. These crops were chosen because their use patterns arerepresentative of all oftheproposed uses for zeta-cypennethrin. One ofthe crops is representative of granular applications (turf), while the rest are representative of spray applications. Exposure estimates for aquatic environments could not be generated strictly for urban areas because a model specificallyaimed at simulating pesticide fate and transport in a complex urban landscape has not yet been developed. 

### In general, outdoor residential uses are comprised of multiple, relatively small, teinporally and spatially variable applications that arenot simulated in agricultural models. However, for aquatic ecological exposure assessments for pesticides which have residential outdoor uses (applicationsto residential lawns, home perimeters, gardens, and other industrial non-agricultural areas), it is assumed that runoff water from rain andior lawn watering may remove pesticide to storm sewers and then directly to surface water. Therefore, the Agency is concerned with the potential for zeta-cypennethrin runoff and/or erosion from residential areas. Even though pyrethroids generally have a strong affmity to bind to soils and surfaces, residue monitoring in non-agricultural areas (e.g., California) have shown that residues of pyrethroids toxic to aquatic organisms are occurring in aquatic areas that receive runoff from suburban developments. Weston et al. (2005) found residues ofpyrethroids from these residential areas and suggested that these areas are unlikely to be unique with similar residueprofiles occurring in other suburban areas, particularly in dryregions where landscape irrigation can dominate seasonal flow in some water bodies. Despitethe limitations in modeling capabilities for outdoor residential uses, this screening-level assessment of zeta-cypemethrin showsthat the use of this pyrethroid on crops can result in the potential for significant toxic exposure and risk to aquatic systems. This concern includes organismsthat frequent the surface and water column, as well as those that live inion the benthos. As zeta-cypermethrin is introduced to surface water via drift or runoff from a crop area, it can disperse down through the water column causing acute toxicity (sub-lethal and lethal effects) to sensitive species. 

### In addition to acute risk, chronic effects are a potential concern for aquatic organisms that are exposed to zeta-cypermethrin in the water colulnn during critical life stages. Possible chronic effects to aquatic life inay also be a concern where an initial zeta-cypennethrin exposure may cause embryological effects (possible neonate mortality and growth effects inay reflect toxin exposure at an early embryological stage) or possible reproductive effects 2 1 days to 60 days following initial exposure. Because zeta-cypermethrin has a high affinity to bind to particulate and organic carbon, sediment can act as a sink where zeta-cypennethrin can accumulate. Toxic exposure of zeta-cypermethrin in the sediment can present a more far-reaching impact on a multitude of organisms than exposure in the water column (e.g., zeta-cypermethrin residues can be expected to rapidly decline in the water column). A wide variety of aquatic organisms depend upon the benthos for food (e.g., fish feeding on invertebrates), reproduction (e.g., salmonid and other speciesusing the benthic substrate for breeding), and shelter (e.g.,bottom dwelling fish, mollusks, aquatic invertebrates, etc.); the benthos is a dynamic system that interacts directly or indirectly with most, if not all aquatic species at somepoint in their development or life stages. Because oftheir influence on various functional parameters in streams, such asprimary productivity, detritus processing, and energy flow, changes in abundances and distributions ofbenthic macroinvertebrates have the potential to reflect changes in stream ecosystems. 

### In addition, because benthic macroinvertebrates are the major prey ofmany species of fish (freshwater and estuarineimarine), they also have societal relevance in terms ofrecreation and ecological biodiversity. As food resources decline or widely fluctuate, fish communities often display increased disease, parasitism, and deformities as a result of less than adequate diet. EFED has a concern for the potential chronic risk that may occur to aquatic organismsfrom zetacypennethrin load in sediments. Chronic toxicant loads in sediments may drive populations toward alimited set of tolerant genotypes over time. Such reductions in genetic diversity could reduce a population's plasticity to adapt to the new stresses that can arise as anthropogenic stress on aquatic ecosystems increases (especially in agricultural areas). This impact cumulativelyresults in structural and functional responses of the aquatic ecosystems andbiota. The timerequired for invertebrate assemblages to return to their natural state, following disturbances such asthose ofpesticide drift andlor runoff, can be on the order of many years for streams, and decades for lakes. 2. Risks to TerrestrialOrganisms

a. SprayApplications: Acute and Chronic Risk to Birds andMammals Pesticide exposure can vary substantially 

### in space, mostly because ofuse patterns. However, terrestrial exposure tends to localize near the application site, extended somewhatby spray drift down wind. In some cases, long range aerial transport can extend this range for a volatile compound. However, in the case of zeta-cypennethrin, volatility isnot an issue of concern. Therefore, to assess risks to terrestrial organisms (e.g., birds and mammals) from spray applications of zeta-cypennethrin, this assessment focuses on the potential for toxic exposure to zeta-cypermethrin residues on food items. Given the low order oftoxicity observed in acutetoxicity studies in birds (LCs0 >2,634 mg a.i./kg diet and LDsO >2,634lng a.i./kgbody weight) and the fact that no effects were observed in the available avian reproduction studies (LOAEC > 50mg a.i./kgdiet, the highest concentration tested), acute and chronic risks to avian speciesresulting from exposure to spray applications of zeta-cypermethrin were not expected. In fact, results of this assessment show that all acute RQs for birds are below acuterisk, acute restricted use, and acute endangered species LOCs (Tables 18and 19), and all chronic RQs arebelow the chronic risk LOC (Table 18). Therefore, acute and chronic risks resulting in adverse effects on growth, reproduction, and survival of avian species are not expected for the maximum application scenarios considered in this assessment. Relative to the use patterns identified in this assessment, exposure of terrestrial organismsto zetacypermethrin spray applications is expected to result in acute dose-based risk to listed mammals (Table 20), and chronic dose-based risk to listed and non-listed mammals (Table21), but not chronic dietarybased risk to listed or non-listed species (Table 22). Acute dietary-based risk to mammals is not typically evaluated, and was not estimated in this risk assessment. Given the moderate toxicity of zeta-cypermethrin in mammals (LDS0 = 86 mg a.i./kg body weight) and the adverse effects of zeta-cypennethrin on body weight and body weight gain in parents and offspring in the available 2- and 3-generation reproduction studies in rats (NOAEC = 100mg a.i./kg diet or 5 mg a.i./kg body weightlday), acute and chronic risks to malnmalian species resulting from exposure to spray applications of zeta-cypermethrin were expected. Acute risks (listed species only) to 15gand 35g mammals feeding on short grass under all scenarios except the barley scenario are anticipated. Risk appears to be highest for mammals exposed under the stone fruits scenario, and lowest for those exposed under thebarley scenario. Based on the highest acute dose-based RQ value of 0.16, a zeta-cypermethrin application rate about one-half of the proposed rate (<0.03 Ib a.i.1A) would be required to ensure that all acute RQ values for spray applications of zeta-cypenllethrin are less than the acute LOCs for all terrestrial organisms. Although no dietary-based chronic RQs for mammals exceed the chronic LOC, thepotential for chronic dose-based risk was identified for mammals feeding on short grass, tall grass, andbroadleaf plantslsmallinsects 

### (Table21). Dose-based chronic RQs exceed the LOC for chronic risk (LOC 1)for all modeled crop uses for exposure via short grass. For mammals feeding on tall grass, dose-based chronic RQs exceed the chronic LOC for the stone fruits and canola scenarios, but not for the non-grass animal feeds or barley scenarios. For mammals feeding on broadleaf plantslinsects, dose-based chronic exceed the chronic LOC for the stone fruits, canola, and non-grass animal feeds scenarios, but not for the barley scenario. All RQs for mammals feeding on fruitslpodsllarge insects and seeds arebelow the chronic LOC. Based on these analyses, zeta-cypermethrin exposureresulting from theproposed uses has thepotential for chronic effects to mammals, including decreased body weight and decreased body weight gain in adults and offspring. The estimated upper-bound dose-based EEC (-3 1mglkg bwlday) on short grass for small mammals under the most conservative application scenario considered in this risk assessment (stone fruits scenario; application rate of 0.05 lb a.i./A,6 applications, and a 7-day interval) is about three times higher than the adjusted NOAEL for small mammals (-1 1mgikg bwlday). Based on the highest chronic RQ value of 2.73, a zeta-cypennethrin application rate of<0.018lb a.i.1A would be required to ensure that chronic RQ values are less than the chronic LOCs for all mammals. One source of uncertainty for this risk assessment is that the dietary-based chronic RQs suggest a lower risk to inammals than do the dose-based chronic RQs. 

### In general, dose-based estimates oftoxicity are the basis ofrisk conclusions sincethey are body-weight specific and typically present a more conservative estimate ofrisk (higher RQs), although the dietary-based estimates doprovide further insight intopotential risks of somecompounds. The dose-based approach considers theuptake and absorption kinetics of a gavage toxicity studyto approximate exposure associated with uptake from a dietary matrix. Toxic response is a function of duration and intensity of exposure. For many compounds a gavage dose represents a very short-term high intensity exposure. Although the dose-based estimates may not reflect reality in that animals do not receive a gavage while feeding, it is possible that a short-duration, highintensity exposure could occur associated with feeding on an agricultural field since many animals may gorge themselves when food items are available. While the dietary-based estimates may suggest greater "realism", they too suffer from some uncertainties. Primarily, the dietary-based approach assumes that animals in the field are consuming food at a rate similar to that of confined laboratory animals despite the fact that energy content in food items differs between the field and the laboratory as does the energy requirements ofwild and captive animals. To bound the estimates ofrisk to mammals resulting from acute and chronic exposure to zetacypermethrin, RQs using mean Kenaga residue values rather than upper-bound values were calculated. Using the non-conservative mean residue values, implying that higher predicted residue values are expected half the time, the acute LOC is not exceeded for mammals based on the acute dose-based risk quotients (RQ range =<0.01 to 0.07) when mean Kenaga residue values are used. 

### In addition,the chronic LOC is not exceeded for mammals based on the dose-based risk quotients (RQ range =<0.01 to 0.96) or the dietary-based RQs (RQ range =0.01 to 0.1 1) when mean residues are used. However, relying on the mean Kenaga residue values for calculating RQs would not protect birds and mammals that consume food items that have residues on the higher end of the residue distribution. An analysis ofthe residue distribution for the different food items using input values from Fletcher et al. (1994) and assuming a lognormal distribution ofresidues on food items showsthat the inean Kenaga values range from about the 62- 

### 87 percentile indicating that up to 38% ofthe higher-end food item residue estimates are not captured by using the inean Kenaga values. In contrast, for the upper-end Kenaga residue estimates, about 3-13% of the upper-end residue estimates were not captured. This highlights the fact that the upper-end Kenaga values are not a maximum exposure level.b. GranularApplications: Acute and ChronicRisk to Birds and Mammals Birds and mammals 

### in the field may be exposed to granules treated with pesticides by ingesting material directly with the diet. They also may be exposed by other routes, such as incidental ingestion of contaminated soil, dermal contact with treated granular surfaces and soil during activities in the treated areas, preening activities, and ingestion of drinking water contaminated with pesticide. To estimaterisk resulting from granular applications of zeta-cypermethrin to turf in this risk assessment, ingestion of granules and consumption of terrestrial invertebrates that have bioconcentrated pesticide residues were considered as routes of exposure. Although none of the acute LOCs are exceeded for avian species of any size, exposure ofterrestrial organisms to granular zeta-cypermethrin applied to turf is expected to result in acuterisk to both listed and non-listed lna~nlnals (Table 23). Specifically, based on the ~~~~lft' method given in the T-REX model, acute RQs (~~~~lft') suggest that granular applications of zeta-cypermethrin may pose an acuterisk to 15g and 35g mammals, but not to 1000gmammals; the RQ for 15gmammals exceeds the LOCs for acute risk, acute restricted use, and acute endangered species, while the RQ for 35g mammals exceeds the LOCs for acute restricted use and acute endangered species. Based on the highest RQ value of 0.83, a zetacypermethrin application rate of about 0.025 lb a.i.1Awould be required to ensure that all acute RQ values for granular applications of zeta-cypermethrin are less than the acute LOCs for all terrestrial organisms. Terrestrial chronic exposure estimates and risks for granular applications of zeta-cypermethrin derived according to a fugacity-based (equilibrium partitioning) approach (Appendix 

### D) demonstratethat chronic risks to birds and lnainmals associated with ingestion ofterrestrial invertebrates that have bioaccumulated zeta-cyperrnethrin granules arenot expected based on a comparison of the estimated earthwonn residue (4.8mg a.i./kg diet) with the avian and mammalian chronic dietary endpoints (50 and 100mg a.i./kgdiet, respectively); RQs are less than the chronic risk LOC (1). In addition, based on a comparison of estimated chronic doses for insectivorous malnmals and adjusted NOAELs, it doesnot appear likely that chronicrisk will result from exposure to granular zeta-cypemethrin for all three size classes of mammals (Table 24). There are a number ofuncertainties associated with the estimations of zeta-cypermethrin concentrations in earthworm tissue and subsequent risks to insectivorous terrestrial wildlife that need to be discussed. First, a zeta-cypermethrin concentration averaged over a 7.6-cm soil (3-inch) depth was used to reflect a concentration acrossthe earthwonn occupied area of soil. However, in some instances it is possible that earthworms may be restricted to shallower depths; therefore, exposure and risk estimates based on a 7.6 cm averaging depth assumption could potentially underestimate exposure and risk depending on the actual depth of earthworm occupied soil. For instance, if concentrations were averaged over a 1-cm soil depth, the estimated earthworm residue would be 36.5 ppm, and there would be potential for chronic risk resulting from exposure to granular zeta-cypermethrin; chronic RQ values would range from 1.42 for 1000gmammals to 3.16 for 15gmammals. In fact, it has been estimated that if soil concentrationswere averaged over depths of 53.2 cm, there would be chronic risks to mammals associated with ingestion of terrestrial invertebrates that have bioaccumulated zeta-cypennethrin granules. Second,thefugacity-based model assumes equilibrium partitioning between bulk soil and soilporewater. In addition, themodel assumes a fixed valuefor soil density, earthworm density, temperature, pore space, organic carbon, and the lipid content ofthe earthworm. Resulting concentrations of zeta-cypermethrin in earthwonn tissue maybe either under- or over-estimated dependingon the soil type, temperature,and sizellipidcontent of the earthworm, at the time of exposure.And lastly, this assessment considers only one route of chronic exposure (i.e., ingestion of terrestrial invertebratesthathavebioaccumulated zeta-cypermethrinfromgranulesinthe soil) for insectivorous birds and mammals. In addition,it isassumed that 100%of the diet is comprised of terrestrial soil invertebrates. Given species-specific feeding habits and dietary requirements, this assumption may overestimate risks associated with ingestion of soil invertebrates that have accumulated zeta-cypermethrin. Other potential routes of exposure including direct ingestion of granules, ingestion of granules that adhere to soil invertebrates, partitioning of dissolved zeta-cypermethrin to sources of wildlife drinking water, and dermal exposure of granules released to surrounding soil and puddles or combined routes of exposure were not considered. Although this model shows that risk to birds and mammals strictly exposed to only bioaccumulated zetacypermethrin in terrestrial invertebrates is low, it is unknown whether other routes of exposure or aggregate routes of exposure would result in unacceptable risk for avian or mammalian receptors.

c. Non-Target Terrestrial Invertebrates Although EFED doesnot quantitatively estimate risk to non-target terrestrial invertebrates, risks can be assessed qualitatively. This hazard assessment shows that zeta-cypermethrin exposure can be expected to result in acute toxicity to honey bees and is considered to be highly toxic on both a contact (LDSo = 0.023 ug a.i./bee) and an oral basis (LDSo =0.172ug a.i.ibee). In addition, results of an acute studywith earthworms yielded a 48-hour contact LCs0value of 26.09ug a.i./cm2for cypermethrin applied to filter paper, categorizing cypermethrin and zeta-cypemethrin as very toxic to earthworms. This rate is equivalent to 2.32 lb a.i./A,a rate about ten times the single maximum application rate of granular zetacypermethrin (0.225 Ib a.i./A),and almost 

### 8 times the maximum annual application rate for spray applications of zeta-cypermethrin (0.3 lb a.i./A). Based on the data available at this time, acute and chronic toxic effects to non-target insects and terrestrial invertebrates resulting from the proposed zetacypermethrin uses cannot be precluded and risk is presumed. d. Terrestrial Plants No data were available to evaluate the risk ofzeta-cypermethrin exposure to non-target terrestrial plants; however, EFED is not concerned about the level ofphytotoxicity of zeta-cypermethrin products because zeta-cypermethrin's neural toxic mode of action is not expected tobe a phytotoxic concern. 

### In addition, based on the lack of studies demonstrating adverse effects ofzeta-cypermethrin or anyother pyrethroid to terrestrial plants, and the fact that no incident reports have reliably linked any other compound in the synthetic pyrethroid class of chemicalsto phytotoxic effects despite being applied on or near agricultural plants, it appears unlikely that zeta-cypermethrin poses a phytotoxic concern. Review of Incident Data Incident reports submitted to EPA since approximately 1994 have been tracked by assignment of "incident numbers" in an Incident Data System (IDS),microfiched, and then entered to a second database, the Ecological Incident Information System (EIIS). An effort has also been made to enter information to EIIS on incident reports received prior to establishment of current databases. Incidents entered into EIIS are categorized into one of several certainty levels:highlyprobable, probable, possible, unlikely, or unrelated. In brief, "highly probable" incidents usually require carcass residues, substantial ChE inhibition in avian and/or mammalian species, andlor clear circumstances regarding the exposure. "Probable" incidents include those where residues were not available and/or circumstances were less clear than for "highly probable." "Possible" incidents include those where multiple chemicals may havebeen involved and it is not clear what the contribution was of a given chemical. The "unlikely" category isused, for example, where a given chemical is practically nontoxic to the category of organism killed and/or the chemical wastested for but not detected 

### in samples. "Unrelated incidents are those that have been confirmed to benot pesticide-related. Incidents entered into the EIIS are also categorized asto use/misuse. Unless specifically confirmed by a state or federal agency to be misuse, or there was very clear misuse such as intentional baiting to kill wildlife, incidents would not typically be considered misuse. Data entry personnel often do not have a copy of the specific label used in a given application, and would not usually be able to detect a variety of label-specific violations, for example. Thenumber of documented kills in EIIS arebelieved to be a very small fraction of total mortality caused by pesticides. Mortality incidentsmust be seen, reported, investigated, and have investigation reports submitted to EPA to have the potential for entry into the database. Incidents often are not seen, due to scavengerremoval of carcasses, decay in the field, or simply because carcasses may be hard to see on many sites andlor few people are systematically looking. Poisoned birds may also move off-site to less conspicuous areas before dying. Incidents seen may not get reported to appropriate authorities capable of investigating the incident because the tinder may not know ofthe importance ofreporting incidents, may not know who to call, may not feel they have the time or desire to call, may hesitate to call because oftheir own involvement in the kill, or the call maybe long-distance and discourage callers, for example. Incidents reported may not get investigated ifresources are limited or may not get investigated thoroughly, with residue analyses, for example. Also, ifkills are not reported and investigated promptly, there will be little chance of documenting the cause, since tissues and residues may deteriorate quickly. Reports of investigated incidents often do not get submitted to EPA, sincereporting by states is voluntary and some investigatorsmay believe that they don't have theresources to submit incident reports to EPA. An effort has also been made to enter information to EIIS on incident reports received prior to establishment of current databases. Although many of these havebeen added, the system is not yet a complete listing of all incident reports received by EPA. In addition, there are a number of uncertainties associated with the data that are reported. Incident reports are not received in a consistent format (e.g., states and various laboratories usually have their own formats), may involve multiple incidents involving multiple chemicals in one report, and may report on only part of a given incident investigation (e.g., residues). While some progress hasbeen made 

### in recent years, both in getting incident reports submitted and entered, there has never been the level of resources assigned to incidents that there has been to the tracking and review of laboratory toxicity studies, for example. This addsto thereasons cited above for why EPA believes the documented kills are but a fraction of total mortality caused by pesticides. Incident reports associated with zeta-cypermethrin are summarized below and in Appendix 

### J.

a. Incidents Involving Aquatic Organisms No incidents involving aquatic organisms have been identified for zeta-cypermethrin. b. Incidents Involving Terrestrial Organisms A total of 2 incidents involving terrestrial exposure havebeen reported to EPA and tracked by EIIS (AppendixJ, TableJ-1). Incident reports show there is one "possible" allegation,and one "unlikely" allegation,that zeta-cypermethrin containingproducts applied to alfalfa caused mortality to honeybees. The "possible" incident was based on a report from a bee keeper on 8/8/2002 that 

### 6 of a pre-existing 32 hives disappeared, and 8 of the remaining hives were queenless and failing. In addition, an erratic or spottybrood pattern was common. An alfalfa field 2.75 miles from the bee keeper's yard was treated 23 days prior to the observations with the zeta-cypermethrin containing product, Fur*. No traces of zeta-cypermethrin were detected when pollen samples were taken and analyzed, although the insecticide coumaphos was identified. The second and "unlikely" incident was based on a report from abee keeper on 9/4/2002 that dead bees were detected in his yard, despite that 7 days prior all hives were fine. A nearby alfalfa field had been treated 50 daysprior to the observed symptomswith zeta-cyperinethrin containing product, Fur*. No traces of zeta-cypermethrin were detected when pollen and bee tissue samples were taken and analyzed, although the insecticide coumaphos was identified at unspecified levels. No information regarding application rate, residue analysis, or time of event relative to application was provided for either of these incidents. In addition, other pesticides were identified asbeing present while zeta-cyperinethrin was not. Therefore, the strength ofthese incidents involving exposure ofterrestrial organisms as an additional line of evidence for this assessment is highly uncertain. 4. Endocrine Effects Results of the available toxicity studies show that zeta-cypermethrin does not appear to affect reproductive parameters in birds or mammals (effects on rats reflected a decrease in pup body weight and body weight gain), but does adversely affect the reproduction of aquatic species (decreased number of offspring in estuarinelinarine invertebrates). Under the Federal Food, Drug and Cosmetic Act (FFDCA), as amended by the Food Quality Protection Act (FQPA), EPA is required to develop a screening program to determine whether certain substances (including all pesticide active and other ingredients) "may have an effect in humans that is similar to an effect produced by a naturally-occurring estrogen, or other such endocrine effects asthe Administrator may designate." Following the recommendations of its Endocrine Disruptor Screening and Testing Advisory Committee (EDSTAC), EPA determined that there was scientific basis for including, aspart of the program, the androgen- and thyroid hormone systems, in addition to the estrogen hormone system. EPA also adopted EDSTAC's recorninendation that the Program include evaluations of potential effects in wildlife. For pesticide chemicals, EPA will use 

### FIFRA and, to the extent that effects 

### in wildlife mayhelp determine whether a substance may have an effect in humans, FFDCA authority to require the wildlife evaluations. As the science develops and resources allow, screening of additional hormone systems may be added to the Endocrine Disruptor Screening Program (EDSP). When the appropriate screening and or testing protocols being considered under the Agency's Endocrine Dismptor Screening Program have been developed, zeta-cyperinethrin may be subjected to additional screening and or testing to better characterize effects related to endocrine disruption. 5. Threatened and Endangered Species Concerns

a. Action Area For listed species assessment purposes, the action area is considered to be the area affected directly or indirectly by the Federal action and not merely the immediate area involved in the action. At the initial screening-level, the risk assessment considers broadly described taxonomic groups and so conservatively assumesthat listed species within those broad groups are collocated with the pesticide treatment area. This means that terrestrial plants and wildlife are assumed to be located on or adjacent to the treated site and aquatic organisms are assumed to be located in a surface water body adjacent to the treated site. The assessment also assumes that the listed species are located within an assumed area which has the relatively highest potential exposureto the pesticide, and that exposures are likelyto decrease with distance from the treatment area. Section III(A) of this risk assessment presents the pesticide use sites that are used to establish initial collocation of species with treatment areas.If the assumptions associated with the screening-level action area result in RQs that arebelow 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, RQsbelow the listed species LOCs for a given taxonomic group indicate no concern for indirect effects upon listed species that depend upon the taxonomic group covered by the RQ as a resource. However, in situations where the screening assu~nptions lead to RQs in excess ofthe listed species LOCs for a given taxonomic group, a potential for a "may affect" conclusion exists and may be associated with direct effects on listed species belonging to that taxono~nic group or may extend to indirect effects upon listed species that depend upon that taxonoinic group as a resource. 

### In such cases, additional information on the biology of listed species, the locations of these species, and the locations ofuse sites could be considered to determine the extent to which screening assumptions regarding an action area apply to a particular listed organism. These subsequent refinement steps could consider how this information would impact the action area for a particular listed organisin and may potentially include areas of exposure that are downwind and downstream ofthepesticide use site. Table 25 summarizes the potential concerns for direct and indirect adverse effects to federally-listed threatened or endangered plants and animals (listed species) due to the proposed uses of zeta-cypermethrin.

Table 25. Listed species risks associated with direct or indirect effectsdue to applications ofzetacypermethrin.
Listed Taxon

Te~~estrial and Semi-Aquatic Plants
- lnonocots and dicots

Beneficial Insects~e~restrial

Invettebrates
Birds, Reptiles, and Terrestrialphase amphibians1

Mammals

Aquatic Vascular Plants Direct Effects

No

Yes

No

No Basis for Direct Effects Conclusion Although toxicity data are not availableto evaluate the risk of zeta-cypemethrin exposure to non-target te~restrial and scmiaquatic plants, EFED is not concerned about the level of phytotoxicityof zetacypennethrin products because zetacypennethrin's neural toxic mode of action is not expected to be a phytotoxicconcetm. In addition, based on the lack of studies demonstrating adverse effects of zetacypennethrin or any other pyl-ethroidto plants, and the fact that no incident reports have reliably linked zeta-cypennethrin or any other compound in the synthetic pyrethroid class of chemicals to phytotoxic effects in tctrestrial or semi-aquatic plants, it appears unlikely that zeta-cype~methrin poses a phytotoxic concem. Zeta-cypennethrin is registered as an insecticide and is highly toxic to non-target insects; therefore, potential risk to nontarget insects is anticipated.

l'he acute endangered species LOC and chronic risk I.OC were not exceeded.

The acute endangered species L.OC and chronic risk LOC were exceeded. Although toxicity data are not available to evaluate the tisk of zeta-cypennethrin exposure to non-target vascularplants, EFED is not concerned about the level of phytotoxicity of zeta-cype~methrin products because zeta-cype~methrin's neural toxic mode of action is not expected Indirect Effects

Yes

Yes

Yes

Yes

Yes Basis for Indirect Effects Conclusion

Potential for indirect effects to plants based on potential effects to mammals or insectslinvertebrates aspollinators or seed dispetsers

lndirect effects to beneficial insects may occur ham potential direct effects to insectivorous mammals.

Indirect effects tobirds may occur from potential direct effects to te~~est~ial insects/invertebrates or mammals.
lndirect effects to mammals may occur from direct effects to tet~estrial insectslinve~tebrates. Potential indirect effects to aquatic plants may occur froin direct effects to pollinators, dispersers, and/or consumers.b. Taxonomic Groups Potentially at Risk Freshwater and Estuarine1 Marine Fish and Aquaticphase ~rn~hibians' Freshwater and EstuarineIMarine

Invertebrates

Aquatic Nonvascular Plants - algae and diatotns

I Birds are used as

The Level 

### I screening assessment process for listed species uses the generic taxonomic group-based process to make inferences on direct effect concerns for listed species. The first iteration ofreporting the results ofthe Level I screening is a listing of pesticide use sites and taxonomic groups for which 

### RQ calculations reveal values that meet or exceed the listed species LOCs. 

### In the majority of cases, screeninglevel risk assessmentsreport RQ calculations for the following broad taxonomic groupings: Birds (also used as surrogate for terrestrial-phase amphibians and reptiles) Mammals Freshwater fish (also used as a surrogate for aquatic phase amphibians) Freshwater invertebrates Estuarinelmarine fish Estuarinelmarine invertebrates Terrestrial plants Algae and aquatic plants

reptilian, and amphibian species are considered equivalent. 

## ' Fish areused as a su~~ogate foraquatic phase amphibians; therefore, potential direct and indirectefl'ectsto endangered fishand amphibian species are considered equivalent. Yes

Yes

No

sumgatespecies to be a phytotoxic concem. In addition, based on the lack of studies detnonst~ating adverse effects of zeta-cypeiinethrin or any other pyrethroid to plants. and the fact that no incident reports have reliably linked zeta-cype~inethrin or any other compound in the synthetic pyrethroid class of chemicals to phytotoxic effects in aquatic vascular plants, it appears unlikely that zeta-cypennethrin poses a phytotoxic concetn.
The acute risk LO(', but not the chronic risk LOC, was exceeded.

The acuterisk LOC and chronic risk LOC were exceeded. Although toxicity data are not available to evaluate the risk ofzeta-cypermethlin exposure to non-target aquatic nonvascular plants, EFED is not concerned about the level ofphytotoxicityofzeta-cype~inethrin products because zeta-cypeimethrin's neural toxic inode ofaction is not expected to be a phytotoxicconcetn. In addition, based on the lack of studies demonstrating adverse effects of zeta-cype~methrin or any other pyethroid to plants. and the fact that no incident reports have reliably linked zeta-cype~inethrin or any other compound in the synthetic pyrethroid class of chemicals to phytotoxic effects in aquatic nonvascular plants. it appears unlikely that zeta-cypermethrin poses a phytotoxic concem. forterrestrial-phase amphibians and reptiles; Yes

Yes

Yes

therefore, potential direct Potential indirect effects to fish and amphibians may occur from direct effects to aquatic invertebrates or mam~nals. Potential indirect effects to aquatic invertebrates tnay occur from direct effects to fish.

Indirect effects to aquatic nonvascular plants arepossible; however, there areno listed aquatic nonvascular plants in the endangered species database.

and indirect effects toendangered avian.I. 

### Discussion 

### ofRisk Quotients Should estimated exposure levels occur in proximity to listed resources, the available screening level infonnation suggests a potential concern for direct effects to listed fish (freshwater and estuarinelmarine), aquatic-phase amphibian, invertebrate (freshwater and estuarinelmarine), beneficial insect/terrestrial invertebrate, and mammalian species associated with areas where zeta-cypermethrin is employed for the proposed uses in this assessment (Table6). More specifically, the available screening level information indicates the following: Based on the toxicity data for all cypermethrin products (alpha-,beta-, theta-, and zetacypermethrin), zeta-cypermethrin granular applications result in acute RQs exceeding acute restricted use and acute endangered species LOCs for freshwater fish. Based on the toxicity data for all cypermethrin products (alpha-, beta-, theta-, and zetacypermethrin),zeta-cypermethrin spray applications result in acute RQs exceeding acute risk, acute restricted use, and acute endangered species LOCs for fish (freshwater and estuarinelmarine). Based on the toxicity data for all cypermethrin products (alpha-, beta-, theta-, and zetacypermethrin), zeta-cypermethrin granular and sprayapplications result in acute RQs exceeding acute risk, acute restricted use, and acute endangered species LOCs for invertebrates (estuarinelmarineand freshwater invertebrates). Based on the toxicity data for all cypermethrin products (alpha-,beta-, theta-, and zetacypermethrin), zeta-cypennethrin granular and spray applications result in RQs exceeding the chronic risk LOC for all invertebrates (estuarinelmarine and freshwater invertebrates). Based on the toxicity data for all cypermethrin products (alpha-, beta-, theta-, and zetacypennethrin), zeta-cypennethrin granular and spray applications result in acute and chronic RQs exceeding all LOCs for benthic organisms. Based on the toxicity data for all cypermethrin products (alpha-, beta-, theta-, and zetacypermethrin),risk to terrestrial invertebrates (including non-target beneficial insects and earthworms)resulting from zeta-cypemethrin granular and spray applications cannot be precluded at this time. Based on the toxicity data for all cypermethrin products (alpha-, beta-, theta-, and zetacypermethrin), zeta-cypermethrin granular applications result in acute RQs exceeding acuterisk, acute restricted use, and acute endangered species LOCs for mammals. Based on the toxicity data for all cypennethrin products (alpha-, beta-, theta-, and zetacypermethrin),zeta-cypermethrin spray applications result in acute dose-based RQs exceeding the acute endangered species LOC for mammals. Based on the toxicity data for all cypermethrin products (alpha-, beta-, theta-, and zetacypermethrin), zeta-cypermethrin spray applications result 

### in chronic dose-based RQs exceeding the chronic LOC for mammals.

### ii. Probit Dose Response Relationship The Agency uses the probit dose responserelationship as a tool for providing additional information on the listed animal species acute levels of concern. Acute listed species LOCs of 0.1 and 0.05 are used for terrestrial and aquatic animals, respectively. As part oftherisk characterization, an interpretation of acute LOCs for listed species is discussed. This interpretation is presented in terms of the chance of an individual event (i.e., mortality or immobilization) should exposure at the estimated environmental concentration actually occur for a specieswith sensitivityto zeta-cypermethrin on par with the acute toxicity endpoint selected for RQ calculation. To accomplish this interpretation, the Agency uses the slope ofthe doseresponse relationship available from the toxicity study used to establish the acute toxicity measures of effect for each taxonomic group. Theindividual effects probability associated with the LOCs is based on the mean estimate ofthe slope and an assumption of a probit dose response relationship. In addition to a single effects probability estimate based on the mean, upper and lower estimates of the effects probability are also provided to account for variance in the slope. The upper and lower bounds ofthe effects probability are based on available information on the 95% confidence interval ofthe slope. A statement regarding the confidence in the estimated event probabilities is also included. Studieswith good probit lit characteristics (i.e., statistically appropriate for the data set) are associated with a high degree of confidence. Conversely, a low degree of confidence is associated with data from studiesthat do not statistically support a probit doseresponse relationship. In addition, confidence in the data set may be reduced byhigh variance in the slope (i.e., large 95% confidence intervals), despite good probit fit characteristics. Lndividual effect probabilities are calculated based on an Excel spreadsheet tool IECV1.l (Individual Effect Chance Model Version 1.1)developed by the U.S. EPA, OPP, Environmental Fate and Effects Division (June 22, 2004). The model allows for such calculations by entering the mean slope estimate (and the 95% confidence bounds of that estimate) asthe slope parameter for the spreadsheet. In addition, the LOC (0.1 for terrestrial animals and 0.05 for aquatic animals) is entered as the desired threshold. The chance of an individual event corresponding to the listed species acute LOCs is calculated based on the formula logLCk= logLCSO+(z/b), where z is the standard normal deviate and b equals the slope. It is important to note that the IEC model output can estimate an event probability as low as 1 in 1 x 1016.This cut-offis a limit in the Excel spreadsheet environment and is not to be interpreted as an agreed upon lower bound threshold for concern for individual effects in any given listed species. If an LDjoor LCsohas been established for a particular taxonomic group, but information isunavailable to estimate a slope from a study, a default slope assumption of4.5 is used asper original Agency assumptions oftypical slope cited in Urban and Cook (1986). In instances where an LC5() or LDjO has not been established for a particular taxonomic group, an individual effects probability is not estimated. 

### FreshwaterFish (MRID44546027) Based on an assumption of a probit dose response relationship with amean estiinated slope of 38.9, the corresponding estimated chance of individual mortality associated with the listed species LOC of 0.05 the acute toxic endpoint for 

### freshwater fish is -1 

### in 1.0 x 10': It is recognized that extrapolation of very low probability events is associated with uncertainty in theresulting estimates. To explorepossible bounds to such estimates, the upper and lower values for the mean slope estimate (-363560 

### to 363637) were used to calculate upper and lower estimates ofthe effects probability associated with the listed species LOC. These values are -1 in 1

### and -1 

### in 1.0 

### x 1016, respectively. Although the Agency has assumed a probit dose response relationship in establishing the listed speciesLOCs, the available data for the toxicity study generating RQs for this taxonomic group do not statistically support a probit dose response relationship (Pearson Chi-Square;

### p <0.001) and so the confidence 

### in estimated event probabilities based on this dose response relationship and the listed species LOC is low. Freshwater Invertebrates (MRID 44423501) Based on an assumption of a probit doseresponse relationship (Pearson Chi-Square;p =0.99) with a mean estimated slope of4.5,the corresponding estimated chance of individual mortality associated with the listed species LOC of 0.05 the acute toxic endpoint for freshwater invertebratesis -1 in 4.18 x 

### lo8. It isrecognized that extrapolation of very low probability events is associated with uncertainty in the resulting estimates. To explorepossible bounds to such estimates, the upper and lower values for the mean slopeestimate (2.3 to 6.7) were used to calculate upper and lower estimates ofthe effects probability associated with the listed species LOC. These values are -1 in 722 and -1 in 6.99 x 1017,respectively. EstuarineIRIarine Invertebrates (Acc. No. 070562) Based on an assumption of a probit dose response relationship with a mean estimated slope of3.74, the corresponding estimated chance of individual mortality associated with the listed speciesLOC of 0.05 the acute toxic endpoint for estuarinelmarine invertebratesis -1 in 1.75 x 

### lo6. It is recognized that extrapolation of very low probability events is associated with uncertainty in the resulting estimates. To explore possible bounds to such estimates, the upper and lower values for the mean slope estimate (1.2 to 6.3) were used to calculateupper and lower estimates of the effects probability associated with the listed species LOC. These values are -1 in 16.9 and -1 in 8.08~ 10'" respectively. Although the Agency has assumed a probit dose response relationship in establishing the listed species LOCs, the available data for the toxicity study generating RQs for this taxonomic group donot statistically support a probit dose response relationship (Pearson Chi-Square;

### p =0.003) and so the confidence in estimated event probabilitiesbased on this dose response relationship and the listed speciesLOC is low.
EstuarineIMarineFish (MRID 90075) Based on an assumption of a probit doseresponse relationship with a mean estimated slope of 54.6, the corresponding estimated chance of individual mortality associated with the listed species LOC of 0.05 the acute toxic endpoint for estuarinelmarine fish is -1 in 1 x 1016. It is recognized that extrapolation of very low probability events is associated with uncertainty in the resulting estimates. To explorepossible bounds to such estimates, the upper and lower values for the mean slope estimate (-557139 to 557248) were used to calculate upper and lower estimates ofthe effects probability associated with the listed species LOC. These values are-1 in 1 and -1 in 1.0 x 1016, respectively. Although the Agency has assumed a probit dose response relationship in establishing the listed species LOCs, the available data for the toxicity study generating RQs for this taxonomic group do not statistically support a probit dose responserelationship (Pearson Chi-Square;p <0.001) and so the confidence in estimated event probabilities based on this dose response relationship and the listed species LOC is low. Benthic Invertebrates (MRID 44074406) Based on an assumption of a probit dose response relationship (Pearson Chi-Square;p =0.86) with a mean estimated slope of 4.2, the corresponding estimated chance of individual mortality associated with the listed species LOC of 0.05 the acutetoxic endpoint for freshwater benthic invertebrates is -1 in 4.30 x 

### lo7.It is recognized that extrapolation of very low probability events is associated with uncertainty in the resulting estimates. To explorepossible bounds to such estimates, the upper and lower values for themean slope estimate (3.1 to 5.3) were used to calculate upper and lower estimates of the effects probability associated with the listed speciesLOC. These values are -1 in 3.63 x 

### lo4and -1 in 3.73 

### x 

### loL', respectively. Mammals (MRID 00056800) Based on an assumption of a probit doseresponse relationship (Pearson Chi-Square;

### p =0.31) with a mean estimated slope of4.1,the corresponding estimated chance of individual mortality associated with the listed species LOC of 0.1 the acute toxic endpoint for mammals is -1 in 4.84 

### x lo4. It isrecognized that extrapolation of very low probability eventsis associated with uncertainty in theresulting estimates. To explore possible bounds to such estimates, the upper and lower values for the mean slope estimate (2.0 to 6.2) were used to calculate upper and lower estimates of the effects probability associated with the listed species LOC. These values are -1 in 44 and -1 in 3.54 x 

### lo9, respectively. Birds (MRID 90071 and 44546024) The available acute toxicity studies (both dietary and dose-based) on avian species were unable to establish toxicity values (LCsoor LDSo).It was demonstrated that the LCs0is greater than 2634ppm and the LDSO is greater than 2000 mg a.i./kg-bw with no treatment-related mortality occurring up to these test levels. Therefore, this risk assessment is unable to fit a probit dose response relationship to the available data to estimate an individual effects probability for avian species based on LCsoor LDsO values.

c. Indirect Effects Analysis The Agency acknowledgesthat pesticides have the potential to exert indirect effects upon the listed organisms by, for example,perturbing forage or prey availability, altering the extent of nesting habitat, and creating gaps in the food chain. 

### In conducting a screen for indirect effects, direct effect LOCs for each taxonomic group areused to make inferences concerning the potential for indirect effects upon listed species that rely upon non-endangered organisms in these taxonomic groups asresources critical to their life cycle. Species specific concerns for zeta-cypennethrin indirect effects to listed organismswill require a determination of the coincidence of zeta-cypennethrin use with locations of listed species and the biologically based resources upon which they depend. TheAgency uses the doseresponse relationship from the toxicity study used for calculating the RQ to estimate theprobability of acute effects associated with an exposure equivalent to the EEC (see Probit Doseresponse Relationship above). 

### In instances where infonnation on the dose response is available, it serves as a guide to establish the need for and extent of additional analysis that may be performed using Services-provided "species profiles" as well as evaluations ofthe geographical and temporal nature ofthe exposure to ascertain if a "not likely to adversely affect" determination can be made. The degree to which additional analyses areperformed is commensurate with the predicted probability of adverse effects from the comparison of the dose response information with the EECs. The greater the probability that exposures will produce effects on a taxa, the greater the concern for potential indirect effects for listed species dependant upon that taxa, and therefore, the more intensive the analysis on thepotential listed species of concern, their locations relative to the use site, and information regarding the use scenario (e.g., timing, frequency, and geographical extent ofpesticide application). Relative to zeta-cypennethrin proposed usage, EFED's screening level analysis shows that there is a concern for indirect effects to listed species that may depend upon other taxonomic group for their survival (e.g., invertebratesas a food source for listed fish, etc.). This assessment identified the potential for direct effects (risks)to beneficial insectslterrestrial invertebrates, mammals, and freshwater and estuarinelmarinefish and invertebrates asresult of the proposed uses of zeta-cyperrnethrin. Therefore, the nature of the toxicological endpoint, Services-provided "species profiles", and further evaluation of the geographical and temporal nature ofthe exposurewill need to be considered to determine if a rationale for a "not likely to adversely effect" determination ispossible. Indirect effects analyses for organisms that depend on insects, mammals, fish, and aquatic invertebrates as a critical component oftheir resource needs are described in Table 25. 

### d. Critical Habitat In the evaluation ofpesticide effects on designated critical habitat, consideration is given to thephysical andbiological features (constituent elements) of a critical habitat identified by the U.S Fish and Wildlife and National Marine Fisheries Services as essential to the conservation of a listed species and which may require special management considerations or protection. The evaluation of impacts for a screening level pesticide risk assessment focuses on the biological features that are constituent elements and is accoinplished using the screening-level taxonomic analysis (risk quotients, RQs) and listed species levels of concern (LOCs) that are used to evaluate direct and indirect effects to listed organisms. The screening-level risk assessment has identified potential concerns for indirect effects on listed species for those organisms dependant upon freshwater and estuarinelmarine fish and invertebrates, beneficial insectslterrestrial invertebrates, and mammals. In light of the potential for indirect effects, thenext step for EPA and the Service(s) is to identify which listed species and critical habitat are potentially implicated. Analytically, the identification of such species and critical habitat can occur 

### in either oftwo ways. First, the agencies could determine whether the action area overlaps critical habitat or the occupied range of any listed species. If so, EPA would examinewhether the pesticide's potential impacts on non-endangered species would affect the listed species indirectly, or directly affect a constituent element of the critical habitat. Alternatively, the agencies could determine which listed species depend on biological resources, or have constituent elements that fall into the taxa that may be directly or indirectly impacted by the pesticide. Then EPA would determine whether use of the pesticide overlaps the critical habitat or the occupied range ofthose listed species. At present, the information reviewed by EPA does not permit use of either analytical approach to make a definitive identification of species that are potentially impacted indirectly or critical habitats that ispotentially impacted directlyby theuse of the pesticide. EPA and the Service(s) are working together to conduct the necessary analysis. This screening-level risk assessment for critical habitat provides a listing ofpotential biological features that, ifthey are constituent elements of one or more critical habitats, would be of potential concern. These correspond to the taxa identified above asbeing of potential concern for indirect effects and include the following: freshwater and estuarinelmarine fish and invertebrates, beneficial insects/terrestrial invertebrates, and mammals. This list should serve as an initial step in problem formulation for further assessment of critical habitat impacts outlined above, should additional work benecessary.

e. Co-occurrence Analysis The goal ofthe analysis for co-location is to determinewhether sites ofpesticideuse are geographically associated with known locationsoflisted species. At the screeninglevel, this analysis is accomplished using the LOCATES database. The database uses location information for listed species at the county level and compares it to agricultural census data for cropproduction at the samecounty level of resolution. The product is a listing of federallylisted speciesthat are located within countiesknown to produce the crop upon which the pesticide will be used. Becausethe Level I screeningassessment considersboth direct and indirect effects across generictaxonomic groupings, it is not possible to exclude any taxonomic group from aMRID 65812

MRID 89037

MRID 89038

MRID 89039

MRID 89043

MRID 89045

MRID 89046

MRID 89047

MRID 89048 ICI (1980) Determination ofthe acutetoxicity of cypermethrin (PP383)to Bluegill Sunfish (Lepomis macrochirus).
Hill, R. W.; Young, B.E.; Comber,M.H.I. (1981)Determination ofthe Acute Toxicity of 3-Phenoxy Benzoic Acid to Rainbow Trout (Salmo gairdneri): Brixham Report No. BllBl2038. (Unpublished study received Dec 30, 1981under 101 82-64; prepared by Imperial Chemical Industries, Ltd., England, submitted by ICI Americas, Inc., Wilmington, Del.; CDL:070562-B). Hill, R.W.; Young, B.E.; Comber, M.H.I. (1981) Determination of the Acute Toxicity of 3-Phenoxy Benzoic Acid to Bluegill Sunfish (Lepomis macrochirus): Brixham Report No. BLlB12086. (Unpublished study received Dec 30, 1981under 101 82-64; prepared by Imperial Chemical Industries, Ltd., England, submitted by ICI Americas, Inc., Wilmington, Del.; CDL:070562-C). Jaber, M.J.; Hawk, R.E. (1981) The Toxicity of Cypermethrin to Fathead Minnow (Pimephales promelas) Embryos and Larvae: Report Series TMUE0007lB. (Unpublished study received Dec 30, 1981 under 10182- 64; submitted by ICI Americas, Inc., Wilmington, Del.; CDL:070562-D). Jaber, M.J.; Hawk, R.E. (198 1 ) The Acute Toxicity of Cypennethrin to Pink Shrimp (Penaeus duorarum): Report SeriesTMUE004lB. (Unpublished study received Dec 30, 1981under 101 82-64; submitted by ICI Americas, Inc.,Wilmington, Del.; CDL:070562-I). Jaber, M.J.;Hawk, R.E. (1981)TheAcute Toxicity of Cypermethrin to Fiddler Crabs (Uca pugilator): Report Series TMUE0003lB. (Unpublished study received Dec 30, 198 1under 10182-64; submitted by ICI Americas, Inc., Wilmington, Del.; CDL:070562-K). Edwards, P.J.; Brown, S.M.; Swaine, H.; et al. (1980) 3-Phenoxybenzoic Acid: Toxicity to First Instar Daphnia magna: Report SeriesRJ 0148B. (Unpublished study received Dec 30, 198 1 under 101 82-64; prepared by Imperial Chemical Industries, Ltd., submitted by ICI Americas, Inc., Wilmington, Del.; CDL:070562-L). Cypermethrin: 21 -day Daphnia magna life cycle study. Submittedby ICI Americas for Phase 4 List B review. MRID 92027-025 (Summary Report) and MRID 00089047 (StudyReport). Edwards, P.J.; Brown, S.M.;Hamer, M.J.; et al. (1980) Cypermethrin: Acute Toxicity to the Mayfly, Baetis rhodani: Report Series RJ 0173B. (Unpublished study received Dec 30, 1981under 10 182-64;prepared by Imperial Chemical Industries, Ltd., submitted by ICI Americas, Inc., Wilmington, Del.; CDL:070562-N).MRID 89049

MRID 00090040

MRID 90070

MRID 9007 1



### MRID 90072

MRID 90073

MRID 90074

MRID 90075 Jaber, M.J.; Hawk, R.E. (1981) The Acute Toxicity of Cypermethrin to Eastern Oysters (Crassostrea virginica): Report SeriesTMUE0009lB. (Unpublished study received Dec 30,1981under 10182-64; submitted by ICI Americas, Inc., Wilmington, Del.; CDL:070562-0). Hend, 

### R.W.; Hendy, R.; Fleming, D.J. (1972?) Toxicity Studies on the Insecticide WL 43467: A Three Generation Reproduction Study in Rats: Group Research Report TLGR.0188.78. (Unpublished studyreceived Dec 30, 1981under 10182-64;prepared by Shell Research, Ltd., England, submitted by ICI Americas, Inc., Wilmington, Del.; CDL:070564-H). Roberts, N.L.; Fairley, C.(1980) The Acute Oral Toxicity (LD50) of Cypermethrin to the Mallard Duck: ICI 302i80305; CTLl81994. (Unpublished study received Dec 30, 1 98 1 under 10 182-64; prepared by Huntington Research Centre, England, submitted by ICI Americas, Inc., Wilmington, Del.; CDL:070561-B). Roberts, N.L. ;Fairley, C.;Woodhouse, R.N. (1980) The Subacute Dietary Toxicity (LC50) of Cypermethrin to the Mallard Duck: ICI 330lWLi80812;55 1 (a)/3. (Unpublished studyreceived Dec 30, 198I under 10182-64;prepared by Huntingdon Research Centre, England, submitted by ICI Americas, Inc., Wilmington, Del.; CDL: 070561-C). Roberts, N.L.; Fairley, C.;Woodhouse, R.N. (1981) The Subacute Dietary Toxicity (LC50) ofCypermethrin to the Bobwhite Quail: ICI 331 WLl808 11;5E.1 (a)/4. (Unpublished study received Dec 30, 198 1 under 10182-64;prepared by Huntingdon Research Centre, England, submitted by ICI Americas, Inc., Wilmington, Del.; CDL: 070561-D). Roberts, N.L.; Fairley, C.; Chanter, D.O.; et 

### al. (1981) The Effect of the Dietary Inclusion of Cypermentrin on Reproduction in the Mallard Duck: ICI 34118164;CTLiCl1091. (Unpublished study received Dec 30, 1981 under 10182-64;prepared by Huntingdon Re- search Centre, England, submitted by ICI Americas, Inc., Wilmington, Del.; CDL:070561

### -E). Roberts, N.L.; Fairley, C.; Chanter, D.O.; et 01. (1981) TheEffect of Dietary Inclusion of Cypermethrin on Reproduction in the Bobwhite Quail: ICI 342181341;CTLICII 105. (Unpublished studyreceived Dec 30, 1981under 101 82-64; prepared by Huntingdon Research Centre, England, submitted by ICI Americas, Inc., Wilmington, Del.; CDL:070561 

### -F). Jaber, M.J.; Hawk, R.E. (1981)TheAcute Toxicity of Cypermethrin to Sheepshead Minnows (Cyprinodon variegatus): Report Series TMUE0002lB. (Unpublished study received Dec 30,1981 under 101 82- 64; submitted by ICI Americas, Inc., Wilmington, Del.; CDL:079561-G).MRID 001 12912

MRID 152739

MRID 155740

MRLD 155770

MRID 155772

MRID 41068003

MRID 4 1068004

MRID 41776115

MRID 41968204

MRID 4 1968208 Milburn, G.; Banham, P.; Birtley, R.;et al. (1982) Cypermethrin: Three Generation Reproduction Studyin theRat: Report No. CTL/P/683. (Unpublished study received Sep 1, 1982under 2F2623; prepared by Imperial Chemical Industries PLC, Eng., submitted by ICI Americas, Inc., Wilmington, DE; CDL:071074-A; 071 075). Everett, C.J., M.J. Hamer, and I.R. Hill. (1983). 3-phenoxybenzoic acid: Toxicity to first instar Daphnia magna (11). Report SeriesRJ 0318B. Prepared and submitted by ICI Plant Protection Division, Bracknell, Berkshire, England. Bull, J.; Wilkinson, W. (1980) Cypermethrin: Laboratory Determination of the Acute Toxicity to Honeybees of Technical Material and an Emulsifiable Concentrate (GFU 061): Report Series: RJ 0 169B. linpublished study prepared by ICI Plant Protection Div. 35 p. Crossland,N. (1982) Aquatic toxicology of cypermethrin. 11. Fate and biological effects in pond experiments. Aquatic Toxicology 2:205222. Crossland, N.; Shires, S.;Bennett, D. (1982) Aquatic toxicology of cypermethrin. 111. Fate, and biological effects of spray drift deposits in fresh water adjacent to agricultural land. Aquatic Toxicology 2:253-270. McLeese, D.; Metcalfe, C.;Zitko, V. (1980) Lethality of permethrin, cypermethrin and fenvalerate to salmon, lobster and shrimp. Bulletin of Environmental Contamination and Toxicology 25:950-955. Stephenson,R. (1981)Aquatic toxicology of cypermethrin: acute toxicology to some freshwater fish and invertebrates in laboratory tests. Aquatic Toxicology 2: 175-185. Freeman, C. (1989) Acute Oral Toxicity Study in Rats: FMC 56701 1.5 Technical: Lab Project Number: A89-2914. Unpublished study prepared by FMC Corp. 33 p. Hoberman, A. (1991) Multigeneration Studywith FMC 56701 Technical Administered Orally via Diet to Cr1:CD (SD)BR Rats: Lab Project Number: A89-2959: 106-007. Unpublished study prepared by Argus Research Laboratories, Inc. 12 1

### 1 p. Overman, 

### M.; Barron, M.; Vaishnav, D. (1990) Cyperinethrin-S (FMC 56701): Acute Toxicity to Rainbow Trout (Oncorhynchusmykiss) Under Flow-through Test Conditions: Lab Project Number: 3903026- 0700-3 140. Unpublished study prepared by Environmental Science and Engineering, Inc. 48 p.MRID 41968209

MRID 4 1968210

MRID 4 19682 1 1

MRID 41968212

MRID 41 968213

MRID 42068504

MRID 4244460 1

MRID 42725301

MRID 42898301 Vaishnav, D.; Yurk, J. (1990) Cypennethrin (FMC 45806): Acute Toxicity to Rainbow Trout (Oncorhynchus mykiss)Under Flow-through Test Conditions: Lab Project Number: 3903026-0750-3 140. Unpublished study prepared by Environmental Science and Engineering, Lnc. 46 p. Ward, T.; Boeri, R. et nl. (1991) Acute Toxicity ofFMC 56701 Technical and Cypermethrin Technical to the Daphnid, Daphnia magna: Lab Project Number: 901 86-FMC: A90-33 10. Unpublished study prepared by Resource Analysts, Inc. 46 p. Overman, M.A., M.G. Barron, and D.D. Vaishnav. (1990). CypermethrinS (FMC 56701): Acute Toxicity to Sheepshead Minnow (Cyprinodon varieqatus) Under Flow-Through Test Conditions. Laboratory Project No. 3903026-0600-3 140. Studyperformed by Environmental Science and Engineering, Inc., Gainesville, FL. submitted by FMC Corporation, Philadelphia, PA. Chandler, A. (1990)FMC 45806: Acute Toxicity to Sheepshead Minnow (Cyprinodon variegatus) Under Flow-through Test Conditions: Lab Project Number: 3903026-0350-3 140. Unpublished study prepared by Environmental Science and Engineering(ESE), Inc. 43 

### p. Ward, T.; Boeri, R. (1991)Acute Toxicity of FMC 56701 Technical and Cypermethrin Technical to the Mysid, Mysidopsis bahia: Lab Project Number: 90 187-FMC: A90-3309. Unpublished study prepared by Resource Analysts, Inc. 52 p. Berry,D. (199 1 )Addendum to Phase 3 Summary of MRID No. 1 1 2912, Cypermethrin: Three Generation Reproduction Study in the Rat: Lab Project Number: CTLiPl683. Unpublished study prepared by ICI Central Toxicology Lab. 6 p. Ward, TimothyJ., Robert L. Boeri, and Mark A Palmieri. (1992). Acute toxicity ofFMC 56701 Technical and Cypermethrin Technical to the Mysid, Mvsidopsis bahia. FMC study number A91-3454. Submitted by FMC Corporation. Performed by EnviroSystems Division, Resource Analysts, Inc. Hainpton, New Hampshire. Wheat, J. (1993) FMC-30980(carbon 14)-Cypermethrin:Chronic Toxicity to the Mysid, Mysidopsis bahia, Under Flow-Through Test Conditions: Lab Project Number: J9205004A. Unpublished study prepared by Toxikon Environmental Sciences. 63p. Wheat, J. (1993) FMC-30980 ((carbon 14)labeled Cypermethrin): Chronic Life-Cycle Toxicity to the Water Flea, Daphnia magna, Under Flowthrough Test Conditions: Lab Project Number: J9205004B: A91 -3479. Unpublished study prepared by Toxikon Environmental Sciences. 71 p.MRID 43293501

MRID 44074401

MRID 44074402

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MRID 44423501

MRID 44546024

MRID 44546025

MRID 44546026

MRID 44546027

MRID 44546028

MRID 44546029 Wheat, J.; Evans, J. (1994) Zetacypermethrin Technical and Cypermethrin Technical: Comparative Acute Toxicity to the Water Flea (Daphnia magna), under Flow-Through Test Conditions: Lab Project Number: 592 10001 B: A9213636. Unpublished study prepared by Toxikon Environmental Sciences. 76p. Rapley, J.; Hamer, M. (1996) Cypermethrin: Toxicity to Chironomus riparius and Hyalella azteca: Lab Project Number: RC0002: 95JH082. Unpublished study prepared by Zeneca Agrochemicals. 15 p. Gentle, W.; Goggin, U.; Rapley, J.; et al. (1996) Cypermethrin: Toxicity to Chironomus tentans in Sediment-Water Systems: Lab Project Number: RC0001: 96JH007. Unpublished study prepared by Zeneca Agrocheinicals. 3 1p. Farrelly, 

### E.; Gentle, W.; Goggin, U.; et al. (1996) Cypermethrin: Toxicity to Hyalella azteca in Sediinent-Water Systems: Lab Project Number: RC0006: 95JH228. Unpublished study prepared by Zeneca Agrochemicals. 30 p. Hamer, M. (1997) Cypermethrin: Acute Toxicity of Short-Term Exposures to Hyalella Azteca: Lab Project Number: TMJ3904B. Unpublished study prepared by Zeneca Agrochemicals. 10p. Johnson, A. (1998) Acute Toxicity (LD50) to Bobwhite Quail: Betacypermethrin: Lab Project Number: PWT 129:PWT 1291962076. Unpublished study prepared by Huntingdon Life SciencesLtd. 38p. Johnson, 

### A. (1998) Dietary (LC50) to the Mallard Duck: Betacypennethrin: Lab Project Number: PWT 128: PWT 1281962075. Unpublished study prepared by Huntingdon Life Sciences Ltd. 40 p. Johnson, A. (1998) Dietary LC50) to the Bobwhite Quail: Betacypermethrin: Lab Project Number: PWT 127:PWT 1271962074. Unpublished study prepared by Huntingdon Life Sciences Ltd. 40p. Sousa,J. (1998) (Carbon 14)-Cypermethrin--Acute Toxicityto Rainbow Trout (Oncorhynchus mykiss) Under Flow-Through Conditions: Final Report: Lab Project Number: 97-1 1-71 66: 12442.1096.6223.108. Unpublished study prepared by Springborn Labs., Inc. 91 p. Sousa, J. (1998) Cypermethrin Technical--Acute Toxicityto Rainbow Trout (Oncorhynchus mykiss) Under Flow-Through Conditions: Final Report: Lab Project Number: 98-1-72 13: 12442.1096.6222.108. Unpublished study prepared by Springborn Labs., Inc. 78 p. Sousa,J. (1998) (Carbon 14)(Beta)-Cypermethrin--AcuteToxicityto Bluegill Sunfish (Lepomis inacrochirus) Under Flow-Through Conditions:MRID 44546030

MRID 4454603 1

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MRID 44546035

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MRID 45 121822 Final Report: Lab Project Number: 97-12-7177: 12442.1096.6225.105. Unpublished study prepared by Springborn Labs., Inc. 91 p. Sousa, J. (1 998) Cypermethrin Technical--Acute Toxicity to Bluegill Sunfish (Lepomis macrochirus) Under Flow-Through Conditions: Final Report: Lab Project Number: 97-12-7195: 12442.1096.6224.105. Unpublished study prepared by Springborn Labs., Inc. 76p. Putt, A. (1998) (Carbon 14)(Beta)Cypermethrin--Acute Toxicity to Daphnids (Daphnia magna) Under Flow-Through Conditions: Final Report: Lab Project Number: 97-9-7079: 12442.1096.6227.115. Unpublished study prepared by Springborn Labs., Inc. 95 p. Putt, A. (1998) Cypermethrin Technical--Acute Toxicity to Daphnids (Daphnia magna) Under Flow-Through Conditions: Final Report: Lab Project Number: 97-11-7138: 12442.1096.6226.115.Unpublished study prepared by Springborn Labs., Inc. 74p. Dionne, 

### E. (1998) Cypermethrin Technical--Acute Toxicity to Sheepshead Minnow (Cyprinodon variegatus) Under Flow-Through Conditions: Final Report: Lab Project Number: 97-12-7197: 12442.1096.6230.505. Unpublished study prepared by Springborn Labs., Inc. 75 p. Sousa, J. (1998) (Carbon 

### 14)(Beta)-Cypennethrin--ChronicToxicity to Sheepshead Minnow (Cyprinodon variegatus) Under Flow-Through Conditions: Final Report: Lab Project Number: 97-1 -72 12: 12442.1096.623 1.505. Unpublished study prepared by Springborn Labs., Inc. 91 p. Sousa, J. (1998) (Carbon 

### 14)(Beta)-Cypermethrin--Chronic Toxicity to Mysids (Mysidopsis bahia) Under Flow-Through Conditions: Final Report: Lab Project Number: 97-12-7 170: 12442.1096.6232.530. Unpublished study prepared by Springborn Labs., Inc. 101 p. Putt, A. (1998) (Carbon-1 4) Beta-Cypemethrin--Acute Toxicity to Mysids (Mysidopsis bahia) Under Flow-Through Conditions: Final Report: Lab Project Number: 97-1 1-7 153: 12442.1096.6229.5 15. Unpublished study prepared by Springborn Laboratories, Inc. 79p. Putt, A. (1 998) Cypennethrin Technical--Acute Toxicity to Mysids (Mysidopsis bahia) Under Flow-through Conditions: Final Report: Lab Project Number: 98-1 -7224: 12442.1096.6228.815. Unpublished study prepared by Springborn laboratories, Inc. 76 p. Hall, A.; Lam, C. (1999)Chronic Toxicity ofMKH 3586 Technical to the Waterflea (Daphnia magna) Under Static Renewal Conditions: Lab Project Number: M684070 1: 108454. Unpublished study prepared by Bayer Corp. 50p.MRID 92027011

MRID 92027025

MRID 92027040 Treacy, C. (1990) ICI Americas Inc. Phase 3 Summary of MRID 00062792. Cypennethrin (PP383): Determination ofthe Acute Toxicity of Active Ingredient (91. 5% purity) to Rainbow Trout (Salmo gairdnerii) Report No. BLlBl2006; Study No.: F342lB.: 12 p. Hamer, M. (1990)ICI Americas Inc. Phase 3 Summary ofMRID 00089047. Cypermethrin: 21 Day Daphnia inagna Life-cycle Study: Report No.: RJ0177B; PP383lCN104. Prepared by ICI Agrocheinicals Jealott's Hill Research Station 17 p. Guttmann, E. (1990) ICI Americas Inc. Phase 3 Summary of MRID 00112912.Cypermethrin: Three Generation Reproduction Study in the Rat: CTL Report No.: CTL/P/683; CTL Study No.: RR0143.: 9 p. Open Literature and Government Reoorts Atkins, EL; Kellum, D; and Atkins, KW. 1981.Reducing pesticide hazards to honey bees: mortality prediction techniques and integrated management strategies. University of California, Division of Agricultural Sciences, Leaflet 2883,23pp Belfroid, A., 

### M. Sikkenk, W. Seinen, K.V. Gestel, J. Hermens. 1994. The toxicokinetic behavior of chlorobenzenes in earthworm (Eisenia andrei) experiments in soil. Environ. Toxicol. Chem. 13: 93-99 Beyer, W. N.; Connor, E; Gerould, S. 1994. Survey of soil ingestion by wildlife. Journal of Wildlife Management 58:375-382. Bott, T.L., Standley, 

### L.J. 2000. Transfer ofbenzo [a] pyrene and 

### 2,2'5,5'-tetrachlorobiphenyl from bacteria to sediment-asociated freshwater invertebrates.Envil-on. Sci. Teclinol. 34:4936-4942. Burns, Lawrence, 1997. Exposure Analysis Modeling System (EXAMS): User Manual and System Documentation. Ecosystem Research Division, National Exposure Research Laboratory. U. S. Environmental Protection Agency, Athens, GA. Carsel, R. F., J. C. Iinhoff, P. R. Huinel, J. M. Cheplick, and A. S.Donigian, Jr. 1997.PRZM-3, A Model for Predicting Pesticide and Nitrogen Fate in the Crop Root and Unsaturated Zones: User's Manual for Release 3.0.National Exposure Research Laboratory, Office ofResearch and Development, U. S. Environmental Protection Agency, Athens, GA. Crossland,N.O., S.W. Shires, and D. Bennett. 1982. Aquatic Toxicology of Cypermethrin. 111. Fate and Biological Effects of Spray Drift Deposits in Fresh Water Adjacent to Agricultural Land. Aquat. Toxicol. 2:253-270. Dunning, J.B. 1984. Body weights of 686 species ofNorth American birds. Western Bird Banding Assoc. Monograph No. 1. Di Toro DM, Zarba CS, Hansen DJ, Berry WJ, SwartzRC, Cowan CE,Pavlou SP, Allen HE Thomas NA, Paquin PR. 1991. Technical basis for establishing sediment quality criteria for nonionic organic chemicals using equilibrium partitioning. Environ Toxicol Chem 10:1 541-1583.Farmer, 

### D., I.R. Hill, and S.J. Maund. 1995. A Comparison of the Fate and Effects of Two Pyrethroid Insecticides (lambda-Cyhalothrin and Cypennethrin) in Pond Mesocosms. Ecoto?ricolo~ 4(4):2 19-244 Fletcher, J.S., J.E.Nellesson and T. G. Pfleeger. 1994. Literature review and evaluation of the EPA foodchain (Kenaga) nomogram, an instrument for estimating pesticide residues on plants. Environ. Tox. And Chem. 13(9):1383-1391. Hallarn, T.G., Lassiter, R.R., Li, 

### J., McKinney, W. 1990. Toxicant-induced mortality in models of Daphnia populations. Environ. Toxicol. Clzem. 9597-621. Hoerger, F. and 

### E.E. Kenaga. 1972. Pesticide residues on plants: correlation of representative data as a basis for estimation of their magnitude in the environment. 

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### F. Corte, eds., Environmental Quality and Safety: Chemistry, Toxicology and Technology. Vol 1. George Theime Publishers, Stuttgart, Germany. pp. 9-28. Kirkwood, RC. (1 983). The relationship of metabolism studies to the modes of action of herbicides. Pestic. Sci. 14:453-460. Mackay, 

### D. And S. Paterson. 1981. Calculating fugacity. Environ. Sci. Technol. 15: 1006-1014. Mineau, P., B.T. Collins, A. Baril. 1996. On the use of scaling factors to improve interspecies extrapolation to acute toxicity in birds. Reg. Toxicol. Pharmacol. 24:24-29. Landrum, P.F., Dupuis, W.S., Kukkonen, J. 1994. Toxicokinetics and toxicity of sediment-associated pyrene and phenanthrene in Diporeia spp.Environ. Toxicol. Clzem. 13: 1769-1 780. Leppanen, M.T. and Kukkonen, J.V.K. 1998.Relationship between reproduction, sediment type, and feeding activity of Lumbriculus variegatus. Envirotl. Toxicol. Chem. 17:2196-2202. McGroddy, S.E.,Farrington, J.W., Gschwend, P.M. 1996. Comparison ofthe in situe and desorption sediment-water partitioning of polycyclic aromatic hydrocarbons and polychlorinated biphenyls. Envivon. Sci. Technol.30:172-1 77. Kedwards, T.J., S.J. Maund, and P.F. Chapman. 1999a. Community Level Analysis of Ecotoxicological Field Studies: 

### I. Biological Monitoring. Environ.Toxicol.Chem. 18(2):149-1 57. Kedwards, T.J., S.J. Maund, and 

### P.F. Chapman. 1999b. Community Level Analysis ofEcotoxicological Field Studies: 11. Replicated-Design Studies. Environ.Toxicol.Chem. 18(2):158-1 66.
Roberts, B.L., and H.W. Dorough. 1984. Relative Toxicities of Chemicals to the Earthworm Eisenia foetida. Environ.Toxicol.Chem. 3(1):67-78. Trapp, S. And J.C McFarlane (eds.). 1995. Plant Contamination Modeling and Simulation of Organic Chemical Processes. Lewis Publishers. Boca Raton, Florida.T-REX. 2005. Terrestrial Residue Exposure Model (T-REX), Version 1.2.3. August 8, 2005. Environmental Fate and Effects Division, Office ofPesticide Programs, U.S. Environmental Protection Agency, Washington, D.C. U.S. EPA. 1982. Pesticide Assessment Guidelines, FIFRA Subdivision E, Hazard Evaluation: Wildlife and Aquatic Organisms, Subsection 71-4. U.S. Environmental Protection Agency, Office of Pesticide Programs. Washington D.C. U.S. EPA. 1989.U.S. Environmental Protection Agency. Endangered Species Program. Washington, DC. Federal Register: 27984-28008, July 3. U.S. EPA. 1992. Comparative analysis of acute avian risk from granular pesticides. Office of Pesticide Programs. U.S. EPA. March 1992. U.S. EPA. 1993. 

### U. S. Environmental Protection Agency. Wildlife Exposure Factors Handbook. Volume I of 11. EPAl600lR-931187a.Office ofResearch and Development, Washington, D. C. 20460. U.S. EPA. 1995. Great Lakes Water Quality Technical Support Document for Wildlife Criteria. Office of Water, Washington D.C. Document Number EPA-820-B095-009. U.S. EPA. 1996. Ecological Effects Test Guidelines, OPPTS 850.2300: Avian Reproduction Test, (Public Draft), Environmental Protection Agency, Office ofPesticide Programs. Washington, D.C. U.S. EPA. 2001. U.S. Environmental Protection Agency. Ecological Risk Assessor Orientation Package. U.S. Environinental Protection Agency, Ecological Fate and Effects Division. Draft Version, August 200 1. U.S. EPA. 2004. U.S. Environmental Protection Agency. Overview ofthe Ecological Risk Assessment Process in the Office of Pesticide Programs, U.S. Environmental Protection Agency: Endangered and Threatened Species Effects Determinations. Office of Prevention, Pesticide, and Toxic Substances. January 23. Urban, D. J. 2000. Guidance for Conducting Screening Level Avian Risk Assessments for Spray Applications ofPesticides. OPPIEFED, USEPA. July 7,2000. Urban, 

### D.J. and N.J. Cook. 1986.Hazard Evaluation Division Standard Evaluation Procedure Ecological Risk Assessment. EPA 54019-85-001. U.S. Environmental Protection Agency, Office of Pesticide Programs, Washington, DC. Weston, D.P, R.W. Holmes, J. You, and M.J. Lydy. 2005. Aquatic toxicity due to residential use of pyrethroid insecticides. Environ.

### Sci. Tecl~nol. 39(Dec. 15): 9778-9784. Willis and McDowell. 1987.Pesticide persistence on foliage. Environ. Contam. Toxicol. 100:23-73.LOCATES database run for a screeninglevel risk assessment. Given the extent of zeta-cypermethrin usage across the U.S. for the proposed uses as well as alreadyregistered uses (virtually everywhere)and the expected large number of listed speciesthat are likelyto occurin countieswhere zeta-cypennethrin is used, a list of endangeredlthreatened species and crop acreage at the county level for the taxonomic groups and crops of concern is not included in this phase ofthe risk assessment process. Given that the potential extent of zeta-cypermethrin usage for theproposed uses as well as alreadyregistered uses includes every state, and that all taxonomic groups are included in the initial LOCATES run for a screening level risk assessment,Appendix H provides the entire list of endangeredlthreatened species at the state level. The registrantmust provide information on the proximity ofFederally listed birds, fish, mammals, amphibians, crustaceans, reptiles, arachnids, insects, plants, snails, and clams to the zeta-cypennethrinuse sites. This requirementmay be satisfiedin one ofthree ways: 1)having membership in the FIFRA Endangered SpeciesTask Force (PesticideRegistration [PR] Notice 2000-2); 2) citingFIFRA Endangered SpeciesTask Force data; or 3) independently producingthese data,provided the information is of sufficient qualityto meet FIFRA requirements. The information will be used by the OPP Endangered Species Protection Program to develop recommendationsto avoid adverse effectsto listed species. C. Description ofAssumptions, Limitations, Uncertainties, Strengths and Data Gaps 1. Exposure For All Taxa This screening-level risk assessment relies on best available estimates of environmental fate and physicochemical properties, maximum application rate of zeta-cypermethrin, maximum number of applications, and the shortest interval between applications. However, several uncertainties and limitations are noted and should be considered in interpreting the results of this risk assessment. Cypermethrin is an enhanced mixture of four diastereoisomers, each of which is present as a pair of enantioiners, resulting in eight isomers. Different ratios ofthe eight isomershave resulted in four different cypennethrin products (alpha-,beta-, theta-, and zetacypermethrin) all of which have similar environmental fate properties. Therefore,the Agency has allowed use ofthe cypermethrin TGAI databaseto fulfill manyregistration requirements for zeta-cypermethrin and exposure data for all cypermethrin products (alpha-,beta-, theta-, and zeta-cypermethrin) have been bridged for risk assessment purposes. The toxicity assessment for terrestrial and aquatic animals is limited by the number of species tested in the available toxicity studies. Use of toxicity data on representative species does not provide information on the potential variability in susceptibility acute and chronic exposures. This screening-level risk assessment relies on labeled statements of the maximum rate of cypermethrin application, the maximum number of applications, and the shortest interval between applications. These assumptions constitute a maximum use scenario. The frequency at which actual uses approach these maximums is dependant on resistance to the pesticide, timing of applications, and market forces. Although the label stated that zeta-cypennethrin can be applied up to a maximum of 0.3 lb a.i./A per season, for this risk assessment, EFED assumed that zeta-cypennethrin was applied at a maximum of 0.3 lb a.i./Aper year. If there are conditions under which there is more than one growing season for a crop within a single year, exposure estimates and risk to aquatic organisms could be significantly underestimated. Examples of crops thathave multiple seasons where this may be a concern include leafy, brassica, and fruiting vegetables in CA, 

### AZ, FL, GA, LA, NC, TX, andlor SC. 2. Exposure For Aquatic Species There are a number of uncertainties and model limitations that should be considered in interpreting the results ofthis Tier I1 aquatic exposure assessment, including: It is assumed for pesticides, such as zeta-cypermethrin, which may have residential outdoor uses (applications to home lawns, gardens, and parks, or termiticide uses applied to subterranean environments or for perimeter treatment, etc), that runoff water from rain and/or lawn watering may remove pesticide to storm sewers and then directly to surface water. However, in general, outdoor residential uses are comprised of multiple, relatively small, temporally and spatially variable applications that are not simulated in agricultural models. Therefore, there is some uncertainty in the aquatic exposure assessment because a model specifically aimed at simulating pesticide fate and transport in a complex urban landscape has not yet been developed to generate exposure estimates strictly for urban areas. For an acute risk assessment, there is no averaging time for exposure. An instantaneous peak concentration, with a 1in 10year return frequency, is assumed. Theuse of the instantaneous peak assumes that instantaneous exposure is of sufficient duration to elicit acute effects comparable to those observed over more protracted exposureperiods tested in the laboratory, typically 48 to 96 hours. In the absence of data regarding time-to-toxic event analyses and latent responses to instantaneous exposure, the degree to which risk is overestimated cannot be quantified. There are no monitoring studies for zeta-cypermethrinin freshwater or marine; therefore, the exposure of aquatic species to zeta-cypennethrin is based entirely on the modeled data. It is noted that the fate characteristics of zeta-cypermethrin indicate that it will partition with the sediment. Sediment monitoring data are not available either. The output of models such as PRZMIEXAMS is dependent upon the quality of the environmental fate input parameters. For zeta-cypennethrin, the environmental fate database is considered to be complete. Estimations regarding the spray drift fraction in the PRZMIEXAMS model runs were based upon the assutnption that the wind speeds at each site are generally below 10mph. Meteorological data fiom coastal regions in California where lettuce is grown suggest that this assumption may not be accurate for this particular scenario. Major uncertainties associated with the standard runoff scenario include the physical construct ofthe watershed and representation ofvulnerable aquatic environments for different geographic regions. The physicochemical properties (pH,redox conditions, etc.) of the standard farm pond are based on a Georgia farm pond. These properties are likely to be regionally specific because of local hydrogeological conditions. Any alteration in water quality parameters may impact the environmental behavior of a pesticide. The farm pond represents a well mixed, static water body. Because the farmpond is a static water body (no flow through), it does not account for pesticide removal through flow through or water releases. The lack of flow through the farm pond provides an environmental condition for accumulation ofpersistent pesticides. The assumption ofuniform mixing does not account for stratification due to thermoclines (e.g.,seasonal stratification in deep water bodies). Additionally, the dimensions ofthe standard runoff scenario assumes awatershed area to water body volume ratio of 10 ha: 20,000m" Thisratio is recommended to maintain a sustainable constructedpond in the Southeastern United States. The use ofhigher watershed area to water body volume ratios (as recommended for sustainable ponds in drier regions of the United States)may lead to higher pesticide concentrations when compared to the standard watershed area to waterbody volume ratio. The standard runoff scenario assumes uniform soils and agronomic management practices across the standard 10 hectare field. Soils can vary substantially across even small areas; this variation is not reflected in the model simulations. Additionally, the impact of unique soil characteristics and soil manageinent practices 

### (e.g.,tile drainage) are not considered in the standard runoff scenario. The assumption ofuniform site and manageinent conditions is not expected to represent some site-specific conditions. Extrapolating the risk conclusions from the standard pond scenarioto other aquatic habitats 

### (e.g.,marshes, streams, creeks, and shallow rivers, intermittent aquatic areas) may either underestimate or overestimate the potential risks in those habitats. 

### 3. Exposure For Terrestrial Species The data available to support the terrestrial exposure assessment for zeta-cypermethrin is consideredto be substantially complete. However, a number of uncertainties and model limitations that should be considered in interpreting the results ofthis terrestrial exposure assessment are discussed below.



### a. Location of Wildlife Species For screening terrestrial risk assessments, a generic bird or mammal is assumed to occupy either the treated field or adjacent areas receiving the pesticide at a rate commensurate with the treatment rate on the target field. This assumption may lead to an overestimation of exposure to species that do not occupy the treated field. The actual habitat requirements of any particular terrestrial species are not considered, and it is assumed that species occupy, exclusively and permanently, the treated area being modeled. This assumption leads to a maximum level of exposure in the risk assessment. b. Routes ofExposure Screening-level risk assessments for spray applications 

### ofpesticides consider dietary exposure alone, and assume that 100%ofthe diet is relegated to single food types foraged only from treated fields. These assumptions are likely to be conservative for many species and will tend to overestimate potential risks. The assumption of 100%diet from a treated area may be realistic for acute exposures, but long-term exposures modeled as single food types composed entirely of material from a treated field is uncertain. It is unclear whether other routes of zeta-cyperinethrin exposure or combined routes of exposurewould result in increased or decreased risk concerns for terrestrial receptors. Other routes of exposure, not considered 

### in this assessment, are discussed below.

I. Incidental Soil Ingestion Exposure This risk assessment does not consider incidental soil ingestion. Available data suggests that up to 15%of the diet can consist of incidentally ingested soil depending on the species and feeding strategy (Beyer et al., 1994). A simple first approximation of soil concentration ofpesticide from spray application shows the effect of not considering incidental soil ingestion: The maximum concentration of the zeta-cypennethrin in the soil canbe determinedby employing the Fugacity Model that was used to assess chronic risk ofbirds and mammals to granular zeta-cypermethrin(AppendixD). Assuming the maximuin exposure scenario (spray application rate of zeta-cypermethrin of 0.05 lb a.i./A the maximum number oftimes 

### (6) and with the minimum application interval (7-days) applied directly to a bare, very low density soil (1 g/cm3)incorporated tol-cm depth),themaximum concentration of zeta-cypermethrin that can be expected to be found in the top 1 -cm of soil is 2.14 mg a.i./kg soil. Including this concentration into the standard screening-level method and assumptions for food item pesticide residues (e.g., 31ppm residue assumption for short grass under the stone fruits scenario) shows that ingestion of soil at an incidental rate of up to 15%ofthe diet would not significantly increase dietary exposure. For example, a 20 g bird consumes approximately 22.8 g food daily. The amount of zetacypermethrin ingested from short grass is approximately 0.71 mg (0.0228 kg food consumed x 31 ppm in food). The amount of zeta-cypermethrin ingested as a result of incidental soil ingestion is approximately 0.007 mg (0.15 x 0.0228 x 2.14 ppin), which represents about 1% ofthetotal exposure due to eating zetacypermethrin-contaminated food-items. ii. Inhalation Exposure The screening risk assessment doesnot consider inhalation exposure. Such exposure may occur through three potential sources: (1) spraymaterial in droplet form at the time of application (2)vapor phase pesticide volatilizing from treated surfaces, and (3) airborne particulate (soil, vegetative material, and pesticide dusts). Available data suggest that inhalation exposure at the time of application is not an appreciable route of exposure for birds. According to research on mallards and bobwhite quail,respirable particle size in birds (particles reaching the lung) is limited to a maximum diameter of 2 to 5 microns. The spray droplet spectra covering the majority of pesticide application situations (AgDrift model scenarios for very-fine to coarse droplet applications) suggests that less than 1 % ofthe applied material is within the respirable particle size. However, the particles still may be ingested, and the model does not address this. Theoretically, inhalation of pesticide active ingredient in the vapor phase may be another source of exposure for some pesticides under some exposure situations. However, considering zeta-cypermethrin's relatively low vapor pressure value and Henry's Law constant, it is unlikely that zeta-cypermethrin will exist in the gaseous phase at levels high enough to cause any adverseeffects via inhalation. Therefore, volatilization from water and soil surfaces and inhalation is not expected to be an important exposure pathway. The impact from exposure to dusts contaminated with the pesticide cannot be assessed generically as partitioning issues related to application site soils and chemical properties render the exposurepotential from this route highly situation-specific. iii. DermalExposure The screening assessment doesnot consider dermal exposure, except asit is indirectly included in calculations of RQs based on lethal dosesper unit ofpesticide treated area. Dermal exposure may occur through three potential sources: (1) direct application of sprayto terrestrial wildlife in the treated area or within the drift footprint, (2) incidental contact with contaminated vegetation, or (3) contact with contaminated water or soil.The available measured data related to wildlife dermal contact with pesticides are extremelylimited. The Agency is actively pursuing modeling techniquesto account for dermal exposurevia direct application of spray and by incidental contact with vegetation. iv. Drinking Water Exposure Drinking water exposure to a pesticide active ingredient may be the result of consumption of surfacewater or consumption of the pesticide in dew or other water on the surfaces oftreated vegetation. For pesticide active ingredients with a potential to dissolve in runoff, puddles on the treated field may contain the chemical. Since zeta-cypennethrin is not highly soluble in water and is expected to adsorb appreciablyto suspended solids and sediment in the water column, the potential for exposureto zeta-cypermethrin from drinking water relative to dietary exposure is likelyto be low.

c. Incidental Pesticide Releases Associated with Use This risk assessment is based on the assumption that the entiretreatment area is subject to zetacypermethrin application at the rates specified on the label. 

### In reality, there is the potential for uneven application of zeta-cypermethrin through such plausible incidents as changes 

### in calibration of application equipment, spillage, and localized releases at specific areas of the treated field that are associated with specifics ofthe type of application equipment used (e.g., increased application at turnabouts when using older ground application equipment). d. Residue Levels Selection As discussed earlier in the exposure section ofthis document, the Agency relies on the work of Kenaga and Fletcher et al. (1994) for setting the assumed pesticide residues in wildlife dietary items. TheAgency believes that these residue assumptions reflect a realistic upper-bound residue estimate, although the degree to which this assumption reflects a specific percentile estimate is difficult to quantify. It is important to note that the field measurement efforts used to develop the Fletcher estimates of exposure involve highly varied samplingtechniques. It is entirely possible that much ofthese data reflect residues averaged over entire above ground plants in the case of grass and forage sampling. Depending upon a specific wildlife species' foraging habits, whole aboveground plant samples may either underestimate or overestimate actual exposure.

e. Dietary Intake 

## - The Differences Between Lab & Field Conditions The acute and chronic characterization of risk rely on comparisons ofwildlife dietary residues with LC50or NOAEC values expressed in concentrations of pesticides in laboratory feed. These comparisons assume that ingestion of food items in the field occurs at rates commensurate with those in the laboratory. Although the screening assessment process adjusts dry-weight estimates of food intaketo reflect the increased mass in fresh-weight wildlife food intake estimates, it does not allow for gross energy and assi~nilative efficiency differencesbetween wildlife food items and laboratory feed. On gross energy content alone, direct comparison of a laboratory dietary concentration- based effects threshold to a fresh-weight pesticide residue estimate would result in an underestimation of field exposure by food consumption by a factor of 1.25 

### - 2.5 for most food items. Only for seeds would the direct comparison of dietarythreshold to residue estimate lead to an overestimate of exposure.Differences in assimilative efficiency between laboratory and wild diets suggest that current screening assessment methods do not account for a potentially important aspect of food requirements. Depending upon species and dietary matrix, bird assimilation of wild diet energy ranges from 23 

### - 80%, and mammal's assitnilation ranges from 41 

### - 85% (U.S. Environmental Protection Agency, 1993). If it is assumed that laboratory chow is formulated to maximize assimilative efficiency (e.g., a value of 85%), a potential for underestimation of exposure may exist by assuming that consumption of food in the wild is comparable with consumption during laboratory testing. In the screening process, exposure may be underestimated because metabolic rates are not related to food consumption. Finally, the screening procedure does not account for situations where the feeding rate may be above or below requirements to meet free living metabolic requirements. Gorging behavior is a possibility under some specific wildlife scenarios (e.g., bird migration) where the food intake rate may be greatly increased. Kirkwood (1983) has suggestedthat an upper-bound limit to thisbehavior might bethetypical intake rate multiplied by a factor of 5. In contrast, there is the potential for avoidance, operationally defined as animals responding to the presence of noxious chemicals in their food by reducing consumption oftreated dietary elements. This response is seen in nature where herbivores avoid plant secondary compounds. However, reduced food intake, particularly over an extendedperiod, could result in reduced survival or reproductive output. 4. Effects Assessment Data gaps, uncertainties, and limitations for the terrestrial and aquatic ecological effects assessment for zeta-cypermethrin are summarized as follows: As mentioned previously, the Agency has allowed use of the cypermethrin TGAI database to fulfill many registration requirements for zeta-cypermethrin, toxicity data for all cypennethrin products (alpha-, beta-, theta-, and zeta-cypermethrin) havebeen bridged for risk assessment purposes, and equivalent toxicity has been assumed. Results of acute toxicity studies in freshwater fish and invertebrates indicate that the zetacypermethrin degradate 3-phenoxy benzoic acid ismuch less toxic than theparent compound. No information is available on the toxicity of other zeta-cypennethrin degradates or on the toxicity of any degradate to terrestrial organisms; therefore, risk resulting from exposure to zeta-cypermethrin degradates could not be evaluated in this assessment. However, based on the assumption that cleavage of the ester bond moiety in theparent structure results in biologically inactive degradates, these compounds should not present a significant risk to non-target organisms. Although there were no aquatic or terrestrial plant data available to the Agency, EFED is not concernedbecause zeta-cypermethrin's neural toxic mode of action is not expected to induce phytotoxic effects. In addition, based on the lack of studies demonstrating adverse effects of zeta-cypermethrin or any other pyrethroid to plants, and the fact that no incident reports have reliably linked zeta-cypermethrin or any other compound 

### in the synthetic pyrethroid class of chemicals to phytotoxic effects despitebeing applied on or near agricultural plants, it appears unlikely that zeta-cypermethrin poses a phytotoxic concern.
There is uncertainty surroundingestimates of chronic toxicity to freshwater invertebrates, estuarinelmarinefish, or benthic organisms, because no data are currently available. Toassess risk to these taxonomic groups, RQs were based on chronic NOAEC values derived using acute-to-chronic ratios as decribed in the Ecological Effects Characterizaion section of this chapter.

• The available acute toxicity study for benthic organisms was not conducted with the exposure system at equilibrium, adding uncertainty to the acute RQs derived for exposure via the sediment. Furthermore, since the chronic RQ for sediment and acute and chronic RQs for pore water were derived fromthe sediment toxicity value, this uncertainty is introduced to all categories of the risk assessment for benthic organisms. These studies have been recently submittedby the pyrethroid working group (PWG)but were not reviewed in time for inclusion in this assessment.

a. Age Class and SensitivityofEffects Thresholds It is generally recognized that test organism age may have a significant impact onthe observed sensitivity to a toxicant. The screening risk assessment acute toxicity data for fish are collected onjuvenile fish between 0.1 and 5 grams. Aquatic invertebrate acute testing is performed on recommended immature age classes (e.g.,frlst instar for daphnids, second instar for amphipods, stoneflies and mayflies, and third instar for midges). Similarly, acute dietary testing with birds is also performed on juveniles, with mallard being 5-1

### 0 days old and quail at 10-14days of age. Testing ofjuveniles may overestimate the toxicity of direct acting pesticides in adults. Asjuvenile organisms do not have fully developed metabolic systems, they may not possess the ability to transform and detoxify xenobiotics equivalent to the olderiadult organism. The screening risk assessment has no currentprovisions for a generally applied method that accounts for this uncertainty. In so far as the available toxicity data may provide ranges of sensitivity information with respect to age class, the risk assessment uses the most sensitive life-stage information as the conservative screening endpoint. 

### b. Lack ofEffects Data for Amphibians and Reptiles Currently, toxicity studies on amphibians and reptiles are not required for pesticide registration. Since these data are lacking, the Agency uses fish as surrogates for aquatic phase amphibians and birds as surrogates for terrestrial phase amphibians and reptiles. These surrogates are thought to be reflective of or protective (more sensitive) of herpetofauna. Amphibians are characterized by a permeable skin. The most important route of exposure for aquatic amphibians would likelybe the dermal route. Using freshwater fishmay be suitable surrogates since exposure would likely be surface area dependent and the gill surface of many fish is a fairly large surface area. Also, both fish and amphibians are ectothermic so metabolic rates and demands would likely be similar. For terrestrial species, however, the difference between amphibians and birds and reptiles and birds is quite large. Terrestrial amphibians and reptiles are both ectotherinic while birds are endothermic; birds have a higher basal metabolic rate to required to maintain constant body temperature. Thehigher metabolic demands of birds may be predispose birds to higher relative exposures. However, this does not address any potential differences in toxicity. To date, there are few controlled studies on reptile species that could be used to compare to similar studies on birds. A pviol-i,there is no strong reason to think that one taxa is more or less sensitive than another. Therefore, it was assumed that the use of surrogate effects data is sufficiently conservative to apply thebroad of species within taxonomic groups. If other species 

### are more or less sensitive to zeta-cypermethrin than the surrogates, risks may beunder- or overestimated, respectively. TheAgency isnot limited to a base set of surrogate toxicity information in establishing risk assessment conclusions. The Agency also considers toxicity data on non-standard test species when available. Further research is required to determinewhether, in general, reptiles and terrestrial-phase amphibians are suitably represented by birds species in assessing risks for zeta-cypennethrin.

c. Use ofthe Most Sensitive Species Tested Although the screening risk assessment relies on a selected toxicity endpoint from the most sensitive species tested, it does not necessarily mean that the selected toxicity endpoints reflect sensitivity ofthe most sensitive species existing in a given environment. The relative position ofthe most sensitive species tested 

### in the distribution of all possible species is a hnction ofthe overall variability among species to a particular chemical. The relationship between the sensitivityofthe most sensitive tested species versus wild species (including listed species) is unknown and a source of significant uncertainty. 

### In addition, in the case of listed species, there is uncertainty regarding the relationship ofthe listed species' sensitivity and the most sensitive species tested. The use of laboratory species has historically been driven by availability and ease ofmaintenance. A widespread comparison of species is lacking, however, even variation within a species can be quite high. 5. Acute and Chronic LOCs Therisk characterization section ofthe assessment includes an evaluation of the potential for individual effects at an exposure level equivalent to the LOC. This evaluation is based on the median lethal dose estimate and doselresponse relationship established for the effects study corresponding to each taxonomic group for which the LOCs are exceeded. V. Literature Cited Environmental Fate 

### MRID Studies Submitted to EPA 

### MRID 421 2900 1 Estigoy, L.; Ruzo, L.; Shepler, 

### K. (1991)Photodegradation of Carbon 14- Acid and Carbon 14-Alcohol Cypermethrin in Soil by Natural Sunlight: Lab Project Number: 2491250W: 191E1390El: PC- 0159. Unpublished study prepared by PTRL West. 115 p. MRID 42 129002

MRID 42 129003

MRID 42 156601

MRID 42 156602 Froelich, L. (1 991). Soil Mobility Studies: Adsorption/Desorption Studies of Cypermethrin: Lab Project Number: 191 E3290E1. Unpublished study prepared by FMC Corp. 65 p. Curry, S. (1991)Leaching of Carbon 14-Cypermethrinin Soil Following Aerobic Aging: Lab Project Number: 191 E3 190E1.Unpublished study prepared by FMC Corp. 97p. Ramsey A. (1991) Environmental Fate Studies: Aerobic Soil Metabolism of Cypermethrin in a Sandy Loam Soil: Lab Project Number: 19 1E2 190EI.Unpublished study prepared by FMC Corp. 99p. Ramsey A. (1 991) EnvironmentalFate Studies: Anaerobic Soil Metabolism of Cypermethrin in a Sandy Loam Soil: Lab Project Number: 19 1E2 190EI.Unpublished study prepared by FMC Corp. 93 p.MRID 42395701

MRID 42459601

MRID 42620501

MRID 42868203

MRID 44876105

MRID 45920801 Estigoy, L.; Ruzo, L.; Shepler, 

### K. (1992) Photodegradation of

## I4c Cypermethrin in Buffered Aqueous Solution at pH 7 by Natural Sunlight: Revised: Lab Project Number: 2471248W: 2471248W-1; 191 El290E1. Unpub- lished study prepared by Pharmacology and Toxicology Research Research Lab (PTRL-West) and FMC Corp. 144 p. Leppert,B. (1992) Amno 2.5 EC Insecticide--Terrestrial Field Dissipation: Lab Project Number: 191 E4191El:RAN-0239. Unpublished studyprepared by FMC Corporation. 182p. Clifton 5.(1992) Environmental Fate Studies: Hydrolysis Studies of Cypermethrin in Aqueous Buffered Solutions: Lab Project Number: 191E1192E1:P-2771. Unpublished study prepared by FMC Corp. 77 p. Giroir, 

### E.; Sherman, L. (1993) Cypermethrin (carbon 14) Bioconcentration by Bluegill Sunfish (Lepomis macrochirus): Lab Project Number: 191 E5491E1: 400 18:PC-0189. Unpublished studyprepared by ABC Labs, Inc. 3 11 p. Ramsey, A.A. 1998. Anaerobic aquatic metabolism of I4C-zetacypennethrin. Unpublished study performed, sponsored and submitted by FMC Corporation, Princeton, NJ. Curry, S.J. 2003. Aerobic aquatic metabolism of '4~-zeta-cyperinethrin. Unpublished study perfonned, sponsored and submitted by FMC Corporation, Princeton, NJ. FMC StudyNo.: 194E2202El. Experimental initiation September 17, 2002 (p. 17), and completion April 2,2003 (p. 12). Final report issued April 28,2003. Open Literature and GovernmentReports EXAMS. 2002. SurfaceWater Model, Version 2.98.04. Environmental Fate and Effects Division, Office of Pesticide Programs, U.S. Environmental Protection Agency, Washington, D.C. Georgia Pecan Commission. A Commercial Users Guide for Georgia Pecans. Available at : http://www.georgiapecans.org/cominercial.html Gorsuch CS. Clemson University Pest Management Handbook. Fruits and Nuts (last updated 3-1 1-2003).

hit^): cu1;~n.clcmson.edu ~~incu~tir: mdln htni Helsel, D.R. and R.M. Hirsch. 1993. Statistical Methods in Water Resources. Elsevier. Amsterdam. Jackson L., Mayberry K., Laemmlen F., Koike S., Schulbach 

### K., ChaneyW. Iceberg lettuce production in California. Vegetable Research and Information Center Univ of California Div of Agriculture andNatural Resources. Publication Number 72 15 (1996). Laskowski D.A.. 2002. Physical and Chemical Properties of Pyrethroids. Rev. Environ. Contam. Toxicol.

174:49-170National Agricultural Statistical Service (NASS). 

### U.S. Dept. Of Agriculture. htl~. 

### ww\\ .usda.(.cn nass NCFAP. 2003. National Center for Food and Agricultural Policy, National Pesticide Use Database. Information taken on February 28, 2005 from the website: hltp. \\ti14 .~lcf'ap.or~ dataknse del'ault.litm PRZM 3.12 beta. 1998. Surface Water Model, Version 3.12Beta. Environmental Fate and Effects Division, Office of Pesticide Programs, U.S. Environmental Protection Agency, Washington, D.C.. Information downloaded from the website

### htt~llwww.epa.e;ov/ceain~ubl/e;water1vrzm3/index.htm. Roof ME. Clemson University Pest Management Handbook. Cotton Insect Control (last updated 5-26- 2004). hftp: cuf;in.clcmso~~.cci~i pn~cu~dc. ma~n.hl~n Takahashi N., Mikami 

### I., Matsuda T., Miyamoto J. 1985. Photodegradation of the pyrethroid insecticide cypermethrin in water and on soil surface. Nippon Noyaku Gakkaishi 10:629-42. Tolnlin C. 1994. Pesticide Manual 10"'edition. British Crop Protection Council. The Royal Society of Chemistry, Cambridge U.K. U.S. EPA. 2002. U. S. Environmental Protection Agency. Guidance for Selecting Input Parameters in Modeling the Environmental Fate and Transport of Pesticides, Version 11. Office of Pesticide Programs, Environmental Fate and Effects Division, U.S. Environmental Protection Agency, Washington, D.C. 21 Pgs. Willis and McDowell 1987, as cited in Carsel, R.F., et.al., "PRZM-3, A Model for Predicting Pesticide and Nitrogen Fate in the Crop Root and Unsaturated Soil Zones: User's Manual for Release 3.0." National Exposure Research Laboratory USEPA, Athens, GA; AQUA TERRA Consultants, Mountain View, CA; and Waterborne Environmental, Inc., Leesburg, VA. p. 5-12. Ecotoxicology Bibliography Ecolo~ical Effects 

### MRID Studies Submitted to EPA Acc. No. 070562 Edwards, P.J., Brown, S.M., Swaine, 

### H. (1980). 3-phenoxybenzoic acid : Toxicity to first instar Daphnia magna. Unpublished report by the Plant Protection Division, submitted 12/28/81 by I C I Americas Inc., Wilmington, Delaware. Acc. No. 070562

Acc. No. 070562 Jaber, M.J. (198 1). The acute and chronic toxicity of cypemethrin to mysid shrimp (Mysidopsis bahia). Unpublished report by 

### EG&G Bionomics, submitted 12128181by ICI Americas Inc., Wilmington, Delaware. Jaber, M.J. (1981).The acute toxicity of cypermethrin to crayfish, (Unpublished report from Union Carbide Environmental Services Laboratory, submitted 12128181by 

### I C I Americas, Wilmington,Delaware.Acc. No. 070562

Acc. No. 070562

Acc. No. 070562

Acc. No. 241598

Acc. No. 241598

Acc. No. 241598

Acc. No. 260647

MRID 00056800

MRID 62792

MRID 62793 Stephenson, R. (1 980) The acute toxicity of WL 43467 to some freshwater invertebrates in static water tests. Unpublished report by Shell Toxicology Laboratory, Tunstall, submitted 12128181by ICI Americas Inc. Stephenson, R.R, Kane, D.F. (1980). The acute toxicity of cypermethrin (WL 43467) to the freshwater shrimp (Gammerus pulex) and larvae of the mayfly (Cleon dipterum), in continuous-& low tests. Unpublished report from Shell Research Ltd, submitted 12128181by I C I Americas, Wilmington, Delaware. Thompson, R.S. (1981) Investigation of the Acute Toxicity of PP 383 to Larvae of the Pacific Oyster (Crassostrea gigas). Unpublished report by the Brixhain Laboratory of Imperial Chemical Industries, Ltd., submitted 12128181by ICI Americas, Inc.; Wilmington, Delaware. Hill, R.W., Maddock, B.G., Hart, B. (1976). Determination of the acute toxicity of PP383 to Rainbow trout (Salmo gairdneri). ICIBrixham Laboratory Report No. BLlB117 1 1,March 1976. Hill, R. W, Maddock, B.G., Hart, 

### B., Gilbert, J. L. (1977). Determination of the acute toxicity of PP383 to bluegill sunfish (Lepomis macrochirus)



### . ICI Brixham Laboratory Report NO. BLlB11775,March 1977. Ross, D.B., D.M. Cameron, N.L. Roberts (1977). TheAcute Qral Toxicity (LDSO) of PP383 to the Mallard Duck. Huntington Research Centre Report No. ICI 128WLl7733,August 1977. Bull, J.M., Wilkinson, W. (1 980). Cypermethrin: Laboratory determination of the acute oral and contact toxicity to honeybees of technical material and an emulsifiable concentrate (GFUO61)


### . Submitted by 1C1,Plant Protection Division



### .Reg. NO. 10182-65. Henderson, C.; Oliver, G.A.; Smith, I.K.; et al. (1980) Cypermethrin (PP383):Acute Toxicity and Local Irritation: Report No. CTLR1537. (Unpublished study received Dec 29, 1980under 101 82-EX-19;prepared by Imperial Chemical Industries,Ltd.,United Kingdom, submitted by ICI Americas, Inc., Wilmington, Del.; CDL:099855-B). ICI (1980)Determination ofthe acute toxicity of cypermethrin (PP383) to Rainbow Trout (Salmo gairdneri). Cypermethrin (PP3838): Toxicity of technical and formulated material to first instar Daphnia inagna. Submittedby ICI Americas for Phase 4 List B review. MRID 92027-0 14 (Summary Report) and MRID 00062793 (Study Report)



### .No date given.