2 analysis plan for evaluating and characterizing risk to non-target species in support of the registration of lambda -cyhalothrin and gamma -cyhalothrin.

Many of the environmental fate properties of lambda -cyhalothrin and gamma -cyhalothrin are known. Nonetheless, there is uncertainty with respec t to the anaerobic soil and anaerobic aquatic metabolism of lambda- cyhalothrin and gamma- cyhalothrin and their overall persistence in the environment. Lambda- cyhalothrin and gamma- cyhalothrin are moderately persistent in aerobic environments , but appear to be more persistent in anaerobic environments. The fate of lambda -cyhalothrin and gamma -cyhalothrin in publicly-owned treatment works is also an uncertainty.

In addition, there are ecologi cal data gaps that need to be addressed to reduce uncertainties in the preliminary risk picture for lambda -cyhalothrin and gamma

cyhalothrin. Lambda - and gamma -cyhalothrin are very highly toxic to fish, aquatic invertebrates and terrestrial invertebrates. However, there is uncer tainty concerning the potential for acute and chronic adverse aquatic effects to listed and non-listed species. Specifically, uncertainty is particularly hi gh for estimating risks to benthic aquatic invertebrates via sediment exposure, aquati c invertebrates via acu te and chronic water column exposures, fish via chronic exposures and aquatic vascular pl ants. There is also uncertainty concerning the potential for advers e effects for via acute exposures to listed and non-listed passerine birds and terrestrial plants.

The potential risk to pollinators and other beneficial insects from use of lambda

cyhalothrin and gamma -cyhalothrin appears to be hi gh. Based on a bioconcentration factor of 4,600X in whole fish, lambda- cyhalothrin and gamma- cyhalothrin are highly bioaccumulative and depuration occurs at moderately slow rates.

# Environmental Fate and Ecological Risk Assessment Problem Formulation in Support of Registration Review of Lambda -cyhalothrin and Gamma -cyhalothrin

Lambda -cyhalothrin Gamma -cyhalothrin PC Code 128897 PC Code 128807

Case No. 7408 Case No. 7437



## November 22, 2010



# Environmental Fate and Effects Division Office of Pesticide Programs US Environmental Protection Agency

3Prepared by: Amanda Solliday, Biologist José L. Meléndez, Chemist Keith Sappington, Senior Scientist

Secondary Review: Mah T. Shamim, Ph.D., Branch Chief

Environmental Risk Branch 5

45 Table of Contents

1. Purpose..................................................................................................................... ............... 6 2. Problem Formulation ......................................................................................................... ..... 6 2.1 Nature of Regulatory Action............................................................................................... . 6 2.2. Previous Risk Assessments................................................................................................. . 7 3. Stressor Source and Distribution .......................................................................................... 12 3.1. Mechanism of Action...................................................................................................... .. 18 3.2. Overview of Pesticide Usage............................................................................................ 19 3.3. Environmental Fate and Transport.................................................................................... 32 4. Receptors................................................................................................................... ............ 46 4.1. Aquatic and Terrestrial Effects ......................................................................................... 46 4.2. Incident Database Review................................................................................................. 57 4.3. Ecosystems Potentially at Risk ......................................................................................... 59 5. Assessment Endpoints ........................................................................................................ .. 46 6. Conceptual Model..................................................................................................... ......... 61 6.1. Risk Hypothesis ............................................................................................................... 61 6.2. Conceptual Diagram ........................................................................................................ 62 7. Analysis Plan ........................................................................................................ ............. 67 7.1. Stressors of Concern ......................................................................................................... 68 7.2. Measures of Exposure....................................................................................................... 68 7.3. Measures of Effect ............................................................................................................ 71 7.4. Integration of Exposure and Effects ................................................................................. 72 7.5. Deterministic and Probabilistic Assessment Methods...................................................... 73 7.6. Endangered Species Assessments..................................................................................... 73 7.7. Drinking Water Assessment ............................................................................................. 74 7.8. Preliminary Identification of Data Gaps........................................................................... 75
7.8.1. Fate............................................................................................................................. 75 7.8.2 Effects ......................................................................................................................... 79 8. References................................................................................................................................ 87 9. Bibliography..................................................................... Appendix A. SRRD data request justification tables................................................................ 108 Appendix B. Aquatic Ecological Effects Data ......................................................................... 126 Appendix C. Open Literature Information................................................................................ 1306 1. Purpose

The purpose of this problem formulation is to provide the foundation for the ecological risk assessment being conducted fo r the registered uses of lambda -cyhalothrin and gamma

cyhalothrin. As such, it articula tes the purpose and objectives of the risk assessment, evaluates the nature of the problem, and provides a plan fo r analyzing the data and characterizing the risk (USEPA, 1998). Additionally, th is problem formulation is in tended to identify data gaps, uncertainties and potential assumptions needed to address those uncertainties in characterizing the ecological risk associated w ith the registered uses of lambda -cyhalothrin and gamma -cyhalothrin.

Lambda -cyhalothrin is a Type II synthe tic pyrethroid insecticide that is registered for numerous agricultural, non-agricultural and residential uses. Type II pyret hroids are characterized by the cyano moiety in the alpha carbon in their chemi cal structure (Type I pyrethroids do not contain this moiety, see Mechanism of Action for add itional distinctions between the two types). Lambda -cyhalothrin is a mixture of two of the 16 possible isomers in its structure. Lambda

cyhalothrin is a restricted-use, br oad-spectrum, insecticide registered in the U.S. for most major aphid, caterpillar, and beetle pests on a wide vari ety of crops and for public health pests such as mosquitoes and cockroaches in non- agricultural uses. It is registered on a wide range of crops (prominent brand names include Warrior® and Karate®, among others) as well as for the treatment of various non-a gricultural settings (residential la wns, pet living quarters, ships and boats, etc.). There are no posthar vest treatment uses. Crops for which it is registered include fruits, vegetables, and row and field crops such as alfalfa, rice, soybean, and wheat. The major agricultural use sites app ear to be alfalfa, cotton, soybeans, winter wheat, and rice.

Gamma -cyhalothrin is another Type II pyrethroid, consisting of one of the two isomers of lambda -cyhalothrin. The environmental fate and ecological effects properties of lambda

cyhalothrin and gamma -cyhalothrin are expected to be similar to each other. The database for

gamma -cyhalothrin was supplemented by available data for lambda -cyhalothrin and vice versa.

Gamma -cyhalothrin is a restricted-use , broad-spectrum, insecticide regi stered in the U.S. for most major aphid, caterpillar and beetle pests on a wide variety of crops a nd non-agricultural uses. It is registered on a wide range of crops under the brand names Cobalt® and Proaxis®, among others, as well as for the treatment of various non-agricult ural settings (eating establishments, feed mills, animal kennels, etc.). It also has a few labels for use as a postharvest treatment for almonds, cherries, nectarines, and peaches. Crops for which it is registered include tree fruit, vegetables, and row and field crops such as alfalfa, rice, so ybean, and wheat. The major use sites appear to be alfalfa, soybean, and winter wheat.

2. Problem Formulation

2.1. Nature of Regulatory Action

This report summarizes the Environmental Fa te and Effects Division’s (EFED) Problem Formulation for the Registration Review of lambda -cyhalothrin and gamma -cyhalothrin.7 Previous risk assessments were completed for the uses of these chemicals, which serve as the basis for this assessment.

The Food Quality Protection Act (FQPA) of 1996 mandated the EPA to implement a new

program, i.e ., registration review ( http://www.epa.gov/oppsrrd1/registration_review/ ). All pesticides distributed or sold in the United States generally must be registered by the EPA. The decision to register a pesticide is based on the co nsideration of scientific data and other factors showing that it will not cause unreasonable risks to human health, workers, or the environment when used as directed on product labeling. The re gistration review program is intended to ensure that, as the ability to assess risk evolves and as policies and practices change, all registered pesticides continue to meet th e statutory standard of no unreas onable adverse effects to human health and the environment. Changes in scien ce, public policy, and pest icide use practices will occur over time. Through the new registration review program, the Agency periodically reevaluates pesticides to make su re that as change occurs, products in the marketplace can be used safely.

As part of the implementation of the new Regist ration Review program purs uant to Section 3(g) of the Federal Insecticide, Fungi cide and Rodenticide Act (FIFRA), the Agency is beginning its evaluation to determine whether lambda -cyhalothrin and gamma -cyhalothrin continue to meet the FIFRA standard for registration. This problem formulation for the environmental fate and ecological risk assessment chapter in support of the registration review is intended for the initial docket opening the public phase of the review process.

2.2. Previous Risk Assessments an d Scientific Advisory Panels

Previous Assessments: Lambda-Cyhalothrin Recent risk assessments conducted on lambda -cyhalothrin and gamma -cyhalothrin, indicated risk concerns for freshwater and estuar ine/marine organisms. In additi on, there were risk concerns for organisms living in the benthos.

In November of 2008, the Agency issued an incremental assessment for the use of lambda

cyhalothrin on non-bearing citrus orchards (D 355940; Meléndez & Solliday 2008). It relied extensively on two previous assessments fo r the chemical (D262918+ and D324224+; Ramasamy et al. 2002 and Meléndez & Hoffmann 2006). The propos ed maximum seasonal application rate of 0.24 lb a.i./A was found to be si milar to previously assessed crops.

Prior to the 2008 review, the Agen cy issued a risk assessment fo r the use of the chemical on cereal grains, cucurbit vegetables, grass forage, fodder and hay, wild rice, and tuberous and corm vegetables (D324224+; Meléndez & Hoffmann 2006) . This review, dated December of 2006, included both aerial and ground applications and the seasonal application rates ranged from 0.06 to 0.18 lb a.i./A. The terrestrial risk portion of this assessment was completely based on a previously issued review (D262918+; Ramasamy et al. 2002) because the estimated exposure concentrations (EECs) derived for the new scenarios using T-RE X were very similar to those8 derived using ELL-FATE 1 for the previously assessed crops. However, the aquatic EECs in this review were higher (parti cularly the chronic EECs for the new us e on wild rice). Furthermore, in the review, risk towards benthic communities was evaluated, utilizing the equilibrium partitioning approach (refer to Section 7.2 ). Multiple levels of concern (LOCs) were exceeded for aquatic species, with the highest risks predicted for aquati c invertebrates via water column exposure. For freshwater and marine inverteb rates, acute risk quotients (R Qs) ranged from 3.57 to 82.80 and the chronic RQs were 2 to 850. For freshwater a nd marine fish, acute RQs ranged from 0.03 to 1.97 and the chronic RQs exceeded the LOC under the NC sweet potato and wild rice scenarios. With respect to the benthic comm unities, acute RQs were 0.09 to 1.58 for freshwater and estuarine/marine organisms (incl uding freshwater and estuarine/ marine benthic organisms), and the chronic RQs ranged from 0.32 to 38.65. For a quatic plants, the RQs were well below the LOC ( ≥ 1), with all values ≤ 0.01. It was stated that ri sk to terrestrial plants could not be evaluated due to lack of toxicity data.

In June of 2002, a risk assessment for several new uses of lambda -cyhalothrin was issued (D262918+; Ramasamy et al. 2002). The new uses included peas and beans (succulent and dried), fruiting vegetables, canola, sugarcane, sorghum, wheat, wh eat hay and other small grains, peanut, pome fruits, stone fruits, tree nuts, t obacco, termite barrier, non- cropland, and conifers and deciduous trees (plantations, nurseries, and s eed orchards). The seasonal application rates ranged from 0.08 to 0.36 lb a.i./A and both ground and aerial applications were possible. The proposed uses exceeded LOCs for freshwater and es tuarine/ marine fish and invertebrates (see also above for a discussion of aquatic organism s). Using ELL-FATE, a wi de range of exposure scenarios, and the most sensitive species, acute RQs for birds were well below the LOCs; however, some of the chronic RQs exceeded the chronic LOC ( ≥ 1), with a range from <0.1 to 2.5. For mammals, the acute RQs ranged from <0.01 to 1.26 while the chronic RQs were <0.1 to 2.5. Lambda -cyhalothrin is considered hi ghly toxic to honeybees, thus, pot ential risk was presumed for pollinators and other beneficial insects.

Several reviews were issued for lambda -cyhalothrin prior to 2002, whic h are not discussed here in detail. These included uses such as rice, co tton, turf and ornamentals, uses in and around buildings, soybeans and sunflowers.

Previous Assessments: Gamma-Cylahothrin There are two reviews for gamma -cyhalothrin. In May of 2009, an incremental risk assessment for the use of gamma -cyhalothrin (D357895+; DeCant 2009) on wheat in several states was issued, which was based on a previous ly issued assessment (D288057+; Maher et al. 2004). The proposed maximum seasonal rate of 0.0176 lb a.i. /A was lower than the previously assessed maximum rate.

The full risk assessment dated March of 2004 is also the new chemical review for gamma

cyhalothrin. The review was consider ed supplemental to the assessment for lambda -cyhalothrin of June of 2002 discussed above (D262918+; Ramasamy et al. 2002). The available studies for

1 ELL-FATE is a model, which is the prec ursor of T-REX. T-REX is describe d in the Analysis segment of this document ( Section 7.2 ).9 gamma -cyhalothrin, despite being mostly suppleme ntal, were considered sufficient for the purpose of bridging and supplementing existing lambda -cyhalothrin data. In the review, it was indicated that the potentia l risks from the proposed gamma -cyhalothrin uses are consistent with risks estimated for lambda -cyhalothrin and other pyrethroids, which include aquatic organisms (fish and invertebrates) and non-targ et insects. Risks to sediment dwelling organisms were also considered possible. The proposed uses included among others alfalfa, cole crops, corn, fruiting vegetables, legume vegetables, pome fruits, rice, cotton, soybean, stone fruits, tree nuts, wheat and conifers and deciduous trees. The maximum proposed application rate appeared to be 0.25 lb a.i./A/season (Appendix A of the review). The c onclusions of the review relied extensively on the lambda -cyhalothrin review, but a spra y drift analysis of the aqua tic risks was performed with three possible levels of binding (0, 50 and 99%), and two levels of drift exposure (high and low), for ground, aerial and airblast applications.

1999 Scientific Advisory Panel A FIFRA Scientific Advisory Panel (SAP) in 1999 examined the sediment toxicity and fate of synthetic pyrethroids. In response to a question regarding whether sediment toxicity data on one pyrethroid (cypermethrin) could be used to predict sediment toxic ity to all pyrethroids, the panel generally supported the method of using data from a few pyrethroi ds to extrapolate information on toxicity to other pyrethroids. The panel recommended testing cypermethrin, bifenthrin (relatively non-toxic to freshwater aquatic organisms, very insoluble in water, large bioconcentration factor) and possibly tefluthrin (h ighly toxic to freshwat er aquatic organisms, stable in water, intermediate solubility in wa ter to cypermethrin and bifenthrin) (USEPA 1999). Although this agreement was made in 1999, the new CFR Part 158 ecological effects data requirements include sediment toxicity tests which are considered particularly important for assessing ecological risks of s ynthetic pyrethroids, including lambda -cyhalothrin and gamma

cyhalothrin.

The SAP commented on the use of K d or K OC to estimate concentrations of synthetic pyrethroids in sediments, recommending that the Agency reconsider K OC as a measure of the binding potential of synthetic pyrethroids to sediment and soil because the use of K d alone limits extrapolation to experime ntal conditions while K OC “allows one to estimate partitioning across a wide variety of soil/sediment types” (USEPA 1999) . The Panel expressed concern that standard methods used to measure sorption may not be applicable to highly hydrophobic compounds due to high solids to water ratio, cons ideration of the char acter of the organic matter, presence of dissolved organic carbon, use of non-representative soils and sediments as sorbents, and improper methods used to measure organic carbon.

While the biota-sediment accumulation factor is a widely accepted method of assessment of bioaccumulation in sediments, the Panel indi cated that the bioconcentration data for Daphnia and Hyalella should be sufficient to predict bioconcen tration of pyrethroids. Finally, the Panel indicated that use of a solid phase microextraction (SPME) method to determine the dissolved concentration in water could be used to account for sorption of pyrethroids to organic carbon and colloids present in the water column in th e measurement of bioconcentration factors.10 In 2003 and in response to the comments from the SAP on pyrethroids, EFED requested the following studies on the pyrethroi ds cyfluthrin, cypermethrin, esfenvalerate and bifenthrin (Rexrode & Meléndez, memorandum dated 12/22/03):

850.1735: Acute Sediment (freshwater) - Test organism: Hyalella azteca and Chironomus dilutus

. - Duration: 10 days, endpoint is survival.

EPA/600/R01/020: Chronic Estuarin e/Marine Sediment Testing - 28 day test on Leptocheirus plumulosus

. - Percentage of neonates that survive as adults. - Growth rate. - Reproduction (#eggs/ female, etc .). - Behavior.

A chronic 65-day freshwater test was also requested only for cypermethrin.

EPA/600/R-991064: Chronic Freshwater Sediment Testing - 65 day test on Chironomus dilutus

. - Survival. - Growth rate. - Reproduction (# eggs/ female, time to ovipos ition, proportion of females ovipositing, % hatch).

2009 Scientific Advisory Panel OPP presented a “Proposed Common Mechanis m Grouping for the Pyrethrins and Synthetic Pyrethroids to a FIFRA SAP in June 2009. O PP proposed two subgroups based on Type I or Type II effects related to sodium current tails and neurobehavioral impact, with esfenvalerate and fenpropathrin showing symptoms of both types. The panel indicate d that substances with mixed characteristics could be included in both groups (see p. 18 of SAP minutes, USEPA 2009). Lambda -cyhalothrin and gamma -cyhalothrin are Type II synthetic pyrethroids; they are cyanosubstituted in the alpha positi on. This mechanism of action assessment was performed by HED/OPP and presented to the SAP to determine if a cumulative assessment is required for the synthetic pyrethroids. Information on the SAP is available in the doc ket (with non-copyright material available at http://www.regulations.gov ) under EPA-HQ-OPP-2008-0489.

EFED does not currently conduct cumu lative ecological risk assessments . EFED does not currently have the methodology to conduct similar cumulative risk assessments for all of the (non-human) biological entities for which EFED has responsibility. In addition to addressing the toxicological aspects of the cumulative effects of multiple pyrethroids to multiple biological entities, a cumulative ecological ri sk assessment would likely require consideration of exposure at a watershed scale in order to incorporate sp atial and temporal variability in pyrethroid applications into cumulative exposure assessmen t. EFED does not currently have the modeling tools developed for conducting this type of a ssessment. However, EFED will consider open literature, currently available models and other lines-of-evidence ( e.g. , monitoring data), as11 available to address the potential for cumulative effects of pyrethroi ds in the risk description of the ecological assessment for lambda - and gamma -cyhalothrin.

Open Literature Information There are multiple articles in the ope n literature that indicate concern over lambda -cyhalothrin,

gamma -cyhalothrin and other pyrethroids’ toxicity towards benthic and other non-target aquatic organisms. Also, the articles illustrate cyhalo thrin’s prevalence over the environment. Please, refer to the Appendix B for further details.

Lambda -cyhalothrin is among the constituents monitored by the National Water Quality Assessment (NAWQA), maintained by the U.S. Geol ogical Survey. One kind of parameter (type of samples) is reported: “ lambda -Cyhalothrin_ water_ filtered_ recoverable_ micrograms per liter,” with a reported percent of samples with this parameter of 7.4 (report units of μ g/L).

Aquatic Life Criteria and Aquatic Life Benchmarks The Clean Water Act requires the Agency to publish water quality criteria that accurately reflect the latest scientific knowledge on the kind and ex tent of all identifiabl e effects on health and welfare which might be expected from the presen ce of pollutants in any body of water, including ground water. While these recommended criteria do not, in themselves, impose any requirements, states and authorized tribes can use them to develop water quality stan dards. US EPA Aquatic Life Ambient Water Quality Criteria document has not been published for lambda -cyhalothrin or

gamma -cyhalothrin (at http://www.epa.gov/waterscience/criteria/ ). However, the Agency is aware of other efforts to derive aquatic life criteria for lambda -cyhalothrin and gamma -cyhalothrin, and will consider this work when characteri zing risk in the forthcoming assessment ( http://www.swrcb.ca.gov/rwqcb5/ water_issues/tmdl/central_valley_projects/central_valley_pesti cides/criteria_method/ and Giddings et al. , 2009).

Based on toxicity values revised by the EPA, the OPP publishes aquatic life benchmarks for freshwater species, based on the most sensitive species from the most recent risk assessments.
For lambda -cyhalothrin and gamma -cyhalothrin, aquatic life benchmar ks have been published (at http://www.epa.gov/oppefed1/ecorisk_ders/a quatic_life_benchmark.htm#benchmarks ). The aquatic life benchmarks are as follows:

Table 2.1. OPP Aquatic Life Be nchmarks (Freshwater) for Lambda - and Gamma -cyhalothrin

All values in μg/L Fish Invertebrates Non-vascular plants

Chemical Name Acute Chronic Acute Chronic Acute
Gamma -cyhalothrin 0.0145 - - 0.00024 - - >2,850
Lambda -cyhalothrin 0.105 0.031 0.0035 0.002 >310

There were no available acute benchmarks for vascul ar plants; thus, a column for vascular plants does not appear in the table.12 Impaired Water Bodies Lambda -cyhalothrin and gamma -cyhalothrin are not individually identified as a cause of impairment for any water bodies listed as impair ed under section 303(d) of the Clean Water Act, based on information provided at http://iaspub.epa.gov/tmdl_waters10/attains_na tion_cy.cause_detail_303d ?p_cause_group_id=885

. However, the pyrethroids as a group have been identified as a cause for impairment for three water bodies in Central Valley, California: Del Puerto Creek, Ingr am Creek Site (from confluence with Hospital Creek to Highway 33 crossing) and second Ingram Creek Site (from confluence with San Joaquin River to confluence with Hosp ital Creek). At the present time, additional bodies of water are being evaluated to be included into the list of impair ed bodies of water; however, they have not been finalized.

Nonetheless, no Total Maximum Daily Load (TMDL) criteria have been developed specifically for lambda -cyhalothrin and gamma -cyhalothrin, based on information provided at http://iaspub.epa.gov/tmdl_waters10/attains_ nation.tmdl_pollutant_de tail?p_pollutant_group_id= 885&p_pollutant_group_name=PESTICIDES . More information on impaired water bodies and TMDLs can be found at http://www.epa.gov/owow/tmdl/ . The Agency invites submission of water quality data for these pesticides. To the exte nt possible, data should conform to the quality standards in Appendix A of the OPP Standard Operating Procedur e: Inclusion of Impaired Water Body and Other Water Quality Data in OPP’s Regist ration Review Risk Assessment and Management Process (at http://www.epa.gov/oppsrrd1/regist ration_review/water_quality_sop.htm ), in order to ensure they can be used quantitatively or qualitati vely in pesticide risk assessments.

3. Stressor Source and Distribution

Lambda -cyhalothrin ( Table 3.1a ) is a synthetic pyrethroid insecticide. Its structure has three rings, two phenyl rings attached to each ot her by an oxygen atom (phenyl and phenoxy), and a cyclopropyl ring. It is a Type II synthetic pyrethroid (it is cyano-substituted in the alpha position). The chemistry of cyhalothrin may be dictated by its ester moiety. It would be expected to hydrolyze as the pH increases; this is confirmed from the hydrolysis study, where lambda

cyhalothrin and gamma -cyhalothrin were stable at pH 5, near ly stable at pH 7 and hydrolyzed at pH 9. The structure of the molecule has thre e chiral centers and a double bond which raise the number of possible isomers to 2 4 = 16. However, lambda -cyhalothrin consists only of two of these isomers. Lambda -cyhalothrin has a 2-ch loro-3,3,3-trifluoropropeny l group and it is 2,2- dimethyl substituted in the cyclopropane ring. Chemically, it is the (S)-alcohol ( Z )-(1R)- cis acid and the (R)-alcohol ( Z )-(1S)- cis acid out of 16 isomeric esters.

Gamma -cyhalothrin ( Table 3.1a ) is a single isomer out of 16 possi bilities of its st ructure, and one of the two isomers in lambda -cyhalothrin. Chemically, it is the (S)-alcohol ( Z )-(1R)- cis acid out of 16 isomeric esters.

In addition, cyhalothrin (not lambda - nor gamma -cyhalothrin) consists of four of the 16 possible isomers in its structure, of which two of them appear in lambda -cyhalothrin and one appears in13 gamma -cyhalothrin ( Table 3.1b ). Cyhalothrin is not a regi stered pesticide in the U.S.

In general, the physicochemical and envir onmental fate properties of cyhalothrin, lambda

cyhalothrin and gamma -cyhalothrin may be expected to be similar to each other. Information about the identification of lambda -cyhalothrin and gamma -cyhalothrin is provided in Table 3.1a

. A summary of physicochemical properties of lambda -cyhalothrin and gamma -cyhalothrin is included in Table 3.1b

.

Table 3.1a. Identification information for lambda -cyhalothrin and gamma -cyhalothrin

CHEMICAL LAMBDA -CYHALOTHRIN GAMMA -CYHALOTHRIN

PARAMETER VALUE(S) (units) SOURCE VALUE(S) (units) SOURCE

CAS Chemical
Name ( R )-cyano(3- phenoxyphenyl)methyl (1 S ,3 S )-

rel -3-[(1 Z )-2-chloro-3,3,3- trifluoro-1-propenyl]-2,2- dimethylcyclopropanecarboxylate Lambda -cyhalothrin data sheet ( S )-cyano(3- phenoxyphenyl)methyl (1 R ,3 R )-3-

[(1 Z )-2-chloro-3,3,3-trifluoro-1- propenyl]-2,2- dimethylcyclopropanecarboxylate Gamma -cyhalothrin data sheet

PC Code 128897 OPP Databases 128807 OPP Databases

Case Number 7408 OPP Databases 7437 OPP Databases

IUPAC Chemical
Name reaction product comprising equal quantities of: ( R )- α -cyano-3-phenoxybenzyl (1 S ,3 S )-3-[( Z )-2-chloro-3,3,3- trifluoropropenyl]-2,2- dimethylcyclopropanecarboxylate and ( S )- α -cyano-3-phenoxybenzyl

(1 R ,3 R )-3-[( Z )-2-chloro-3,3,3- trifluoropropenyl]-2,2- dimethylcyclopropanecarboxylate
or of ( R )- α -cyano-3-phenoxybenzyl (1 S )- cis -3-[( Z )-2-chloro-3,3,3- trifluoropropenyl]-2,2- dimethylcyclopropanecarboxylate and ( S )- α -cyano-3-phenoxybenzyl

(1 R )- cis -3-[( Z )-2-chloro-3,3,3- trifluoropropenyl]-2,2- dimethylcyclopropanecarboxylate Lambda -cyhalothrin data sheet ( S )- α -cyano-3-phenoxybenzyl (1 R ,3 R )-3-[( Z )-2-chloro-3,3,3- trifluoropropenyl]-2,2- dimethylcyclopropanecarboxylate

or ( S )- α -cyano-3-phenoxybenzyl (1 R )- cis -3-[( Z )-2-chloro-3,3,3- trifluoropropenyl]-2,2- dimethylcyclopropanecarboxylate Gamma -cyhalothrin data sheet

CAS Reg. No. 91465-08-6 Lambda -cyhalothrin data sheet 76703-62-3 Gamma -cyhalothrin data sheet14 Table 3.1a. Identification information for lambda -cyhalothrin and gamma -cyhalothrin

LAMBDA -CYHALOTHRIN GAMMA -CYHALOTHRIN CHEMICAL

SOURCE PARAMETER VALUE(S) (units) VALUE(S) (units) SOURCE

Chemical Structure

(from chemical’s data sheet)

Lambda -cyhalothrin data sheet accessed 05/24/10: http://www.alanwood.net/pesticides/ lambda -cyhalothrin.html

. Gamma -cyhalothrin data sheet accessed 05/24/10: http://www.alanwood.net/pesticides/ gamma -cyhalothrin.html

.15 Table 3.1b. Summary of physicochemical properties of lambda -cyhalothrin and

gamma -cyhalothrin

PARAMETER VALUE(s) units (chemical name) SOURCES

CAS Reg. No. 68085-85-8 (cyhalothrin) 91465-08-6 ( lambda -cyhalothrin) 76703-62-3 ( gamma -cyhalothrin) TOXNET/ HSDB 2

Lambda - and gamma

cyhalothrin data sheets

Composition Cyhalothrin Lambda -cyhal Gamma -cyhal

60:40 A:B 1:1 enantiomers of pair B Only S-alcohol ( Z

)-(1R)- cis acid where, (1R,3R,alphaR) and (1S,3S,alphaS) is known as pair A (1R,3R,alphaS) and (1S,3S,a lphaR) is known as pair B Alternative nomenclature for Pa ir B is also (S)-alcohol ( Z )- (1R)- cis acid and (R)-alcohol ( Z )-(1S)- cis acid Laskowski, 2002 & lambda - and gamma

cyhalothrin data sheets

Molecular Formula C 23 H 19 ClF 3 NO 3 (cyhalothrin, lambda -cyhalothrin and gamma -cyhalothrin) Lambda -cyhalothrin and

gamma -cyhalothrin’s data sheets

Molecular Weight 449.86 (cyhalothrin, lambda -cyhalothrin and gamma -cyhalothrin) TOXNET/ HSDB

Melting Point Below 10oC (cyhalothrin) 49.2oC ( lambda -cyhalothrin) TOXNET/ HSDB & EXTOXNET 3

NPIC 4

Boiling Point 187-190°C @ 0.2 mmHg; decomposes at 275°C (cyhalothrin) TOXNET/ HSDB

Solubility in Organic Solvents In acetone, dichloromethane, methanol, diethyl ether, ethyl acetate, hexane, toluene, all > 500 g/l at 20°C (cyhalothrin) TOXNET/ HSDB

Solubility in Water 5.0 x 10 -3 mg/L or 5.0 ppb, temp not spec. (cyhalothrin)
5 x 10 -3 mg/L @ pH 6.5 and 20°C ( lambda -cyhalothrin)
5.00 x 10 -3 mg/L or 5.00 ppb @ 20°C ( lambda

cyhalothrin) 0.0021 ppm or 2.1 ppb at 20 o C ( gamma -cyhalothrin) ‘Not Soluble’ TOXNET/ HSDB EXTOXNET & 00151580 Laskowski 2002, MRID 45794902 FAO, 2000

Vapor Pressure 7.5 x 10 -9 mm Hg at 25°C (cyhalothrin)
1.56 x 10 -9 mmHg at 20°C ( lambda -cyhalothrin) 2.60 x 10 -9 mmHg at 25 o C ( gamma -cyhalothrin)
7.73 x 10 -10 mmHg at 20 o C ( gamma -cyhalothrin) ‘Non-volatile under field conditions’ ( ≤ 9.98 x 10 -7 mmHg) TOXNET/ HSDB Laskowski 2002 MRID 45794902

USEPA, 2008

Henry’s Law Constant 1.5 x10 -6 atm-m 3 /mol (cyhalothrin) 1.9 x 10 -7 atm-m 3 /mol at 20 o C ( lambda -cyhalothrin)
2.18 x 10 -7 atm-m 3 /mol at 20 o C ( gamma -cyhalothrin) TOXNET/ HSDB Laskowski, 2002
MRID 45794901
Octanol-Water Partition Coefficient
K OW (log K OW ) 6.3 x 10 6 (6.8) (temp. not specified) (cyhalothrin) 1.00 x 10 7 (7.00) (temp. not spec.) ( lambda -cyhalothrin) 90698 (4.96) at 19 o C ( gamma -cyhalothrin) TOXNET/ HSDB Laskowski, 2002
MRID 45794902

Octanol-Air Partition Coefficient
K OA (log K OA ) Constant Law sHenry' RTK

K K K OW

AW OW OA ==

1.3 x 10 12 (12.1) ( lambda -cyhalothrin)
1.0 x 10 10 (10.0) ( gamma -cyhalothrin) 1.282 x 10 10 – 1.043 x 10 11 (10.108-11.018) ( lambda

cyhalothrin); EPIWEB estimate Calculated Values EPIWEB v.4.0 Estimate

2 http://toxnet.nlm.nih.gov/ (data for cyhalothri n, accessed 05/24/10).

3 EXTension TOXicology NETwork at http://extoxnet.orst.edu/pips/lambdacy.htm (accessed 05/24/10).

4 National Pesticide Information Center at http://npic.orst.edu/npicfact.htm (accessed 05/24/10).16 Table 3.1b. Summary of physicochemical properties of lambda -cyhalothrin and

gamma -cyhalothrin

PARAMETER VALUE(s) units (chemical name) SOURCES

K

AW (log K AW ) K AW = C air /C water = HLC/RT
7.9 x 10 -6 (-5.1) ( lambda -cyhalothrin) 9.0 x 10 -6 (-5.0) ( gamma -cyhalothrin)
6.05 x 10 -5 (-4.22) ( lambda -cyhalothrin); EPIWEB v. 4.0 estimate ‘Non-volatile’ Calculated Values
EPIWEB v.4.0 USEPA, 2008

C water /C air ⎟ ⎠ ⎞ ⎜ ⎝ ⎛

×× ×××

= 6 air water 10GMW P 760RT S

C C = RT/HLC

130,000 (unitless) ( lambda -cyhalothrin) 110,000 (unitless) ( gamma -cyhalothrin) ‘Non-volatile’ Calculated USEPA, 2008

OH Radical Reaction Half-life 0.340 days ( lambda -cyhalothrin) (Assumptions: 12-hr days; 1.5 x 10 6 OH/cm 3 ) EPIWEB v.4.0 Estimate

Biomagnification Potential Presumption: If log K OA > 5, log K OW > 2 and the rate of chemical transformation is low, the chemical may biomagnify in terrestrial food chains **

For lambda -cyhalothrin and gamma -cyhalothrin, log K OA > 5, log K OW > 2 and rate of transformation is moderate in the environment, and it appears to moderate in fish, with very

high bioconcentration factors (4,600x) and moderate to slow depuration (~9 days, based on a bioaccumulation in

fish study conducted with cyhalothrin); it appears that lambda -cyhalothrin and gamma -cyhalothrin may have some potential to biomagnify in terrestrial food chains under certain circumstances. ** Gobas et al. 2003 and Armitage & Gobas, 2007 support this presumption utilized here only as a broad reference to determine the potential for biomagnification.

Cyhalothrin, lambda -cyhalothrin and gamma -cyhalothrin have a high molecular weight of 449.9 g/mol. They also have a small solubility (only 2-5 ppb) and a high octanol/ water partition coefficient (log K OW = 5.0 to 7.0). Based on their octanol/ water partition coefficient, it appears that lambda - and gamma -cyhalothrin have the potential to bioaccumulate/ bioconcentrate (K OW ≥ 1000) in fish and other aquatic organism s. With a vapor pressure of ~10 -9 mmHg, they are considered “non-volatile under fiel d conditions.” Their calculated Henry’s Law Constant is low (~10 -7 atm-m 3 /mol). In addition, their C water /C air is ≥ 110,000, which classify them as “nonvolatile” (USEPA 2008). Thus, lambda -cyhalothrin and gamma -cyhalothrin do not have a potential to volatilize fro m dry or wet surfaces. The potenti al to volatilize may be further attenuated in the environment by thei r tendency to bind to organic matter ( e.g. , soils, sediments, or organic matter and partic ulate in natural water).

Lambda -cyhalothrin was found to be highly bioacc umulative (4,600x in the whole body), and its depuration rate is considered moderately slow (h alf-depuration time of around 9 days). It is noted that its predicted depuration rate based on K OW alone would be much longer ( i.e ., 30 to > 300 days), thus suggesting that bi otransformation processes may be contributing to its faster depuration. Biotransformation in biota is typical for synthe tic pyrethroids. For lambda

cyhalothrin and gamma -cyhalothrin, the log K OA is in the range of 10-12 (calculated and EPIWEB v.4.0 estimates), the log K OW is ~5-7 and the rate of transformation is moderate in the environment and in fish, with high bioconcentra tion factors and a moderately slow rate of17 depuration, it appears that lambda -cyhalothrin and gamma -cyhalothrin may have some potential to biomagnify in terrestrial food chains under certain circumstances ( i.e. , if biotransformation rates are sufficiently slow), based on the presumption made by Gobas et al. and Armitage & Gobas, in 2003 and 2007 articles, respectively, as they relate to poorly metabolized chemicals. Even though EFED has not adopted an official re ference or guideline to distinguish chemicals that biomagnify, Gobas et al. and Armitage & Gobas’ presumpti on was utilized here as a general or broad reference to detect th e potential for biomagnifi cation in terrestrial food chains for these chemicals.

Even though various degradates were observed in the laboratory studies ( e.g. Compound Ia and Compound V), it was found that the majority were the result of the ruptur e of the ester bond of the parent molecule. It has been believed that the resulting molecules are not as toxic as the parent because they presumably have lost the neurotoxic mode of action. Table 3.1c shows the chemical structures of cyhalothri n’s major degradation products. At this time, it appears that only Compound XV may be considered a st ressor of concern in the fo rthcoming environmental fate and ecological risk assessment.18 Table 3.1c. Major Transformation Products of Lambda -cyhalothrin & Gamma -cyhalothrin

Common

Name Chemical Name Structure

Compounds

Ia and Ib Ia : (1 RS )- cis -3-( ZE)-2-chloro3,3,3-trifluoro-1-propenyl)-2,2- dimethylcyclopropanecarboxylic

acid and

Ib : (1 RS )- trans -3-( ZE)-2-chloro3,3,3-trifluoroprop-1-enyl)-2,2- dimethylcyclopropanecarboxylic

acid

Compound IV 3-Phenoxybenzaldehyde

O

O

Compound V 3-Phenoxybenzoic acid

O

O OH

Compound VI 3-Phenoxybenzenemethanol

O OH

Compound XV 1 α (S*),3 α ( Z )-(±)-cyano-[3-(4'- hydroxyphenoxy)phenylmethyl]-

3-(2-chloro-3,3,3-trifluoro-1-propenyl)-2,2-dimethylcyclopropanecarboxylate

3.1. Mechanism of Action

Both, lambda -cyhalothrin and gamma -cyhalothrin are neural toxi c insecticides acting through direct contact and ingestion. The insecticidal e ffect of pyrethroids is characterized by a rapid “knock down,” or paralysis, of insects. All pyrethroids act as axonic poi sons, affecting both the peripheral and central nervous systems, and sh are similar modes of action. The primary19 biological effects of lambda -cyhalothrin, gamma -cyhalothrin and other pyrethroids on insects and vertebrates reflect an inhibition of the correct fi ring of neurotransmitter delivery signals from one cell to another. Specifically, this involves ne rve membrane inhibition of the voltage-gated Ca 2+ (calcium ion) channels coupled with a stimulatory effect on the voltage-gated Na + (sodium ion) channels. The pyrethroids (including lambda -cyhalothrin and gamma -cyhalothrin) share similar modes of action, and are consider ed axonic poisons that affect both the peripheral and central nervous system.

It is now well established that severe neurological symptoms of poisoning with pyrethroids in mammals and insects are the re sult of modification of the Na + channels activity (cellular pores through which Na + ions are permitted to enter the axon to cause excitation) (Matsumura, 1985). Advanced electrophysiological experiments using voltage clamp and patch clamp, together with ligand-binding and ionic flux experiments, have unve iled unique actions of pyrethroids of keeping the Na + channel in the open state for an extremel y long period, sometimes as long as several seconds. This modification of Na + channel properties leads to hyperactivity of the nervous system. This action leads to spontaneous depol arizations, augmented ne urotransmitter secretion rate and neuromuscular block, which ultimately results in paralysis of the insect.

Pyrethroids have also been shown to suppress GABA and glutamate receptor-channel complexes and voltage-activated Ca 2+ channels, but the toxicological significance of these actions is uncertain. Relative to physiol ogical responses, researchers ha ve designated two types of pyrethroids, Type I ( e.g. , bifenthrin, resmethrin, permethrin) and Type II ( e.g. , deltamethrin, fenvalerate, cyfluthrin, lambda -cyhalothrin and gamma -cyhalothrin). Type I pyrethroids action is mainly associated with compounds that caus e nerve excitation symp toms typified by the appearance of repetitive firing of axons in the peripheral nervous system and a negatively correlated temperature re versible knockdown property (Clark & Matsumura, 1987). In insects, the type II pyrethroids predominantly cau se ataxia and uncoordinated movement.

3.2. Overview of Pesticide Usage

The Label Use Information System (LUIS) report & Usage/Label Use Reports for lambda

cyhalothrin and gamma -cyhalothrin were based on all labels available for the chemical. The use information presented in this problem formulatio n was obtained from the LUIS report, from the Chemical Profiles for lambda -cyhalothrin and gamma -cyhalothrin, supplied by BEAD, and from various labels as indicated. Lambda -cyhalothrin and gamma -cyhalothrin have numerous uses. A summary of agricultura l use patterns for lambda -cyhalothrin and gamma -cyhalothrin, based on the indicated labels for lambda -cyhalothrin and gamma -cyhalothrin, are shown Tables 3.2a and
3.2b

.

Table 3.2a. Summary use information for LAMBDA -cyhalothrin based on Karate® Insecticide with Zeon TechnologyTM (EPA Reg. No. 100-1097) and WARRIOR Insecticide with Zeon Technology® Insecticide (EPA Reg. No. 100-1112) representative labels.

Use Single App. Rate (lb. a.i./A) Number of Apps. Seasonal App. Rate (lbs. a.i./A) Interval
Between Apps. (days) App.
Method Incorporation Depth (inches)20 Table 3.2a. Summary use information for LAMBDA -cyhalothrin based on Karate® Insecticide with Zeon TechnologyTM (EPA Reg. No. 100-1097) and WARRIOR Insecticide with Zeon Technology® Insecticide (EPA Reg. No. 100-1112) representative labels.

Use Single App. Rate (lb. a.i./A) Number of Apps. Seasonal App. Rate (lbs. a.i./A) Interval
Between Apps. (days) App.
Method Incorporation Depth (inches) Barley, Buckwheat, Oat, Rye, Triticale, Wheat, Wheat hay 0.03 2 0.06 3 G,A 0

Cucurbit Vegetables: Chayote (fruit), Chinese waxgourd, Citron melon, Cucumber, Gherkin, Ghourd (edible), Momordica species, Muskmelon (hybrids and/or cultivars of Cucumis melo ), Pumpkin, Summer squash (includes various varieties), Winter squash (also includes various types of squash), Watermelon (includes hybrids and/or varieties) 0.03 6 0.18 5 G,A 0

Grass Forage, Fodder and Hay: Pasture and rangeland grass, Grass grown for hay or silage, and Grass grown for seeds. 0.03 1 per cutting;

3 per

season 0.03 per cutting; 0.09 per

season 30 per cutting G,A 0

Tuberous and Corm Vegetables: Arracacha, Arrowhoot, Artichoke (Chinese and Jerusalem only), Edible canna, Cassava (bitter and sweet), Chayote (root), Chufa, Dasheen, Ginger, Leren, Potato, Sweet potato, Tanier, Turmeric, Yam (bean and true) 0.03 4 0.12 7 G,A 0

Cotton 0.04 5 0.2 3 G,A,ULV 0

Peanuts 0.03 4 0.12 7 G,A 0 Rice, Wild rice 0.04 3 0.12 3 first applic.
& 5-7 for subsequent applications G,A 0

Sorghum 0.03 2-3 0.08 3 G,A 0 Sugarcane 0.04 4 0.16 7 G,A 0
Alfalfa and Alfalfa Grown for Seed 0.03 per cutting 4 0.12 Not Specified G,A 0

Canola 0.03 3 0.09 5 G,A 021 Table 3.2a. Summary use information for LAMBDA -cyhalothrin based on Karate® Insecticide with Zeon TechnologyTM (EPA Reg. No. 100-1097) and WARRIOR Insecticide with Zeon Technology® Insecticide (EPA Reg. No. 100-1112) representative labels.

Use Single App. Rate (lb. a.i./A) Number of Apps. Seasonal App. Rate (lbs. a.i./A) Interval
Between Apps. (days) App.
Method Incorporation Depth (inches) Corn, Field corn, Popcorn, Seed corn, Sweet corn 0.09 at plant, 0.03 for foliar applications Field corn,

popcorn, seed corn
2-4

Sweet

corn: 14-16 Field corn, popcorn, seed

corn: 0.12 from at plant

and foliar applications

Sweet corn: 0.48 Field corn, popcorn, seed

corn: 3

Sweet corn: Not specified G,A, T band and In-furrow 0

Cole Crops: Broccoli, Brussels sprouts, Cabbage, Cavalo broccolo, Cauliflower, Chinese broccoli, Chinese cabbage, Chinese Mustard, Kohlrabi 0.03 8 0.24 5 G,A 0

Fruiting Vegetables: Tomato, Tomatillo, Peppers (bell and non-bell), Eggplant, Ground cherry, Pepino 0.03 12 0.36 5 G,A 0

Legume Vegetables: (Beans and Peas): Edible podded, Succulent, Shelled or Dried shelled 0.03 4 0.12 5 G,A 0

Soybeans 0.03 2 0.06 5 G,A 0 Lettuce (head and leaf) 0.03 10 0.3 5 G,A 0 Onion (bulb), Garlic 0.03 8 0.24 5 G,A 0 Pome Fruits: Apple, Crabaple, Loquat, Mayhaw, Oriental pear, Pear, Quince 0.04 5 0.20 5 G,A 0

Stone Fruits: Apricot, Sweet and tart cherry, Nectarine, Peach, Plum, Chickasaw plum, Damson plum, Japanese plum, Plumcot, Prune 0.04 5 0.20 5 G,A 0

Sunflower 0.03 4 0.12 5 G,A 0
Tobacco 0.03 3 0.09 7 G,A 022 Table 3.2a. Summary use information for LAMBDA -cyhalothrin based on Karate® Insecticide with Zeon TechnologyTM (EPA Reg. No. 100-1097) and WARRIOR Insecticide with Zeon Technology® Insecticide (EPA Reg. No. 100-1112) representative labels.

Use Single App. Rate (lb. a.i./A) Number of Apps. Seasonal App. Rate (lbs. a.i./A) Interval
Between Apps. (days) App.
Method Incorporation Depth (inches) Tree Nuts: Almonds, Beech nut, Brazil nut, Butter nut, Cashew, Chestnut, Chinquapin, Filbert (hazlenut), Hickory nut, Macadamia nut, Black walnut, English walnut (Persian), Pecan 0.04 4 0.16 5 G,A 0

Conifers and deciduous trees (plantations and nurseries) 0.04 6 0.24 Not specified G,A 0

Conifers and deciduous trees (seed orchards) Apply directly to the tree, or for ground application

apply at max of 0.156
For aerial applications: max. 0.117 4@0.125

5@0.1 0.5 Not specified G,A 0

Non-cropland (adjacent to crops) (excluding public land) As per general use directions As per general

use directions 0.2 As per general use directions G 0

Non-Bearing Citrus Orchards (Calamondin, Citron, Citrus hybrids, Grapefruit, Kumquat, Lemon, Lime, Mandarin, Orange (sweet and sour), Pummelo, Satsuma mandarin, Tangerine, Uniq fruit and/or hybrids of these) 0.04 6 0.24 Not specified G,A 023 Table 3.2b. Summary use information for GAMMA -cyhalothrin based on Proaxis® EX Insecticide (EPA Reg. No. 62719-522) and Proaxis® Insect icide (EPA Reg. No. 74921-3) labels.

Use Single App. Rate (lb. a.i./A) Number of Apps. Seasonal App. Rate (lbs. a.i./A) Interval
Between Apps. (days) App.
Method Incorporation Depth (inches) Wheat, Wheat hay and Triticale 0.015 2 0.03 5 G,A

Cotton 0.02 5 0.1 3 G,A,ULV 0

Peanuts 0.015 4 0.06 7 G,A 0
Rice 0.02 3 0.06 3 first applic.
& 5-7 for subsequent applications G,A 0

Sorghum 0.015 2-3 0.04 3 G,A 0 Sugarcane 0.02 4 0.08 7 G,A 0
Alfalfa and Alfalfa Grown for Seed 0.015 per cutting 4 0.06 Not Specified G,A 0

Canola 0.015 3 0.045 5 G,A 0 Corn, Field corn, Popcorn, Seed corn, Sweet corn 0.045 at plant, 0.015 for foliar

applications Field corn,

popcorn, seed corn 2-4

Sweet

corn: 14-16 Field corn, popcorn, seed

corn: 0.06 from at plant

and foliar applications

Sweet corn: 0.24 from at

plant and foliar applics. Field corn, popcorn, seed

corn: 3

Sweet corn: Not specified G,A, T band and In-furrow 0

Cole crops: Broccoli, Brussels sprouts, Cabbage, Cavalo broccoli, Cauliflower, Chinese broccoli, Chinese cabbage, Chinese Mustard, Kohlrabi 0.015 8 0.12 5 G,A 0

Fruiting Vegetables: Tomato, Tomatillo, Peppers (bell and non-bell), Eggplant, Ground cherry, Pepino, Okra 0.015 12 0.18 5 G,A 0

Legume Vegetables: (Beans and Peas): Edible podded, Succulent, Shelled or Dried shelled 0.015 4 0.06 5 G,A 0

Soybeans 0.015 2 0.03 5 G,A 0 Lettuce (head and leaf) 0.015 10 0.15 5 G,A 0 Onion (bulb), Garlic 0.015 8 0.12 5 G,A 0 Pome Fruits: Apple, Crabaple, Loquat, Mayhaw, Oriental pear, Pear, Quince 0.02 5 0.1 5 G,A 024 Table 3.2b. Summary use information for GAMMA -cyhalothrin based on Proaxis® EX Insecticide (EPA Reg. No. 62719-522) and Proaxis® Insect icide (EPA Reg. No. 74921-3) labels.

Use Single App. Rate (lb. a.i./A) Number of Apps. Seasonal App. Rate (lbs. a.i./A) Interval
Between Apps. (days) App.
Method Incorporation Depth (inches) Stone Fruits: Apricot, Sweet and tart cherry, Nectarine, Peach, Plum, Chickasaw plum, Damson plum, Japanese plum, Plumcot, Prune 0.02 5 0.1 5 G,A 0

Sunflower 0.015 4 0.06 5 G,A 0 Tobacco (air dried) 0.015 3 0.04 5 7 G,A 0 Tree Nuts: Almonds, Beech nut, Brazil nut, Butter nut, Cashew, Chestnut, Chinquapin, Filbert (hazlenut), Hickory nut, Macadamia nut, Black walnut, English walnut (Persian), Pecan, Pistachios 0.02 4 0.08 5 G,A 0

Conifers and deciduous trees (plantations and nurseries) 0.02 6 0.12 Not specified G,A 0

Conifers and deciduous trees (seed orchards) Apply directly to the tree, or for ground applic. apply at max of 0.078
For aerial applications: max. 0.059 4@0.0625

or 5@0.05 0.25 Not specified G,A 0

Non-cropland (adjacent to crops) (excluding public land) As per general use directions As per general

use directions 0.1 As per general use directions G 0

Ornamentals (Commercial greenhouses, Shadehouses, Nurseries) 0.027 lb a.i./100 gal 1 Not specified 0.28 Not specified G 0

Turf (Sod farms and Grass seed farms) 0.1 2-3 0.28

1 . The actual application rate is not stated, according to the instructions, the plants should be thoroughly covered, including stems, twigs and foliage.

In general, for a given crop, the application rate for gamma -cyhalothrin is around half that for lambda -cyhalothrin. For agricultural products, a pplication methods incl ude aerial or ground spray (foliar) and ULV. In addi tion, soil applications ar e possible, particularly for corn, at plant.

Various differences were noted between the labe ls. The following groups were only present in the labels for lambda -cyhalothrin: cucurbit vegetables; gra ss forage, fodder and hay; tuberous and corm vegetables and non-bearing citrus. In a ddition, the following individual crops were not25 present in the gamma -cyhalothrin labels: wheat, wheat hay and triticale. The following crops appear only in the evaluated gamma -cyhalothrin labels: okra and pi stachio. Also, ornamentals and turf appear in the labels for gamma -cyhalothrin (see also Tables 3.5a and 3.5b ).

The inspected labels for lambda -cyhalothrin and gamma -cyhalothrin have the following Environmental Hazards statements:

“This pesticide is extremely toxic to fish and aquatic organisms and toxic to wildlife. [For terrestrial uses: (in the evaluated labels for lambda -cyhalothrin) ] Do not apply directly to water or to areas where surface water is present or to intertidal areas below the mean high water mark. Do not apply when weather conditions favor drift from treated areas. Drift and runoff from treated area s may be hazardous to aquatic organisms in neighboring areas. Do not contaminate water when disposing of equipment washwater.

This product is highly toxic to bees exposed to direct treatment or residues on blooming crops or weeds. Do not apply this product or allow it to drift to blooming crops or weeds if bees are visiting the treatment area.”

Under spray drift precau tions, the labels for lambda -cyhalothrin and gamma -cyhalothrin require a buffer zone of 10 ft around certain bodies of water, such as lakes, reservoirs, rivers, permanent streams, marshes or natural ponds, estuaries and commercial fish farm ponds, so as to allow growth of a maintained vegetativ e filter strip. The agricultural products should not be applied by ground equipment within a distance of 25 ft, or by aer ial equipment within a distance of 150 ft, or by ULV within a distance of 450 ft from freshw ater or estuarine/ marine bodies of water ( e.g. lakes, reservoirs, rivers, permanent streams, ma rshes or natural ponds, es tuaries and commercial fish farm ponds).

For lambda -cyhalothrin, formulations include microen capsulated, pelleted/tableted, emulsifiable concentrate, wettable powder, gra nular, ready-to-use, and impregnate d material. This chemical is applied in a number of ways. Agricultural app lication methods include sprays made with ground and aerial application equipment, chemigation via irrigation equipm ent, foliar treatment, and soil treatments (in-furrow, T-banding, etc.). Non-agricultural application methods for lambda

cyhalothrin include soil treatments ( e.g. , subslab injection and “r odding”), foam application, contact and/or surface treatment, premise treatment (including outdoor premise treatment), crack and crevice and/or spot treatment, perimeter treatment, indoor general surface treatment, spot treatment, ultra low volume, broadcast, mound treatment, mound drench, band treatment, indoor premise treatment, barrier treatment, void treat ment, prepaving treatment, impregnated covering application, wood surface treatment, manual br ush treatment, and injection treatment.

For gamma -cyhalothrin, formulations include mi croencapsulated, liquid, emulsifiable concentrate, ready-to-use, impregnated co llar-tag, pressurized li quid, and granular. Gamma

cyhalothrin products are applied as crack and crevice and/or spot tr eatment, indoor general surface treatment, indoor premise treatment, void treatment, contact and/or surface treatment, spray, directed spray, perimeter treatment, broad cast, chemigation, high volume spray (dilute),26 low volume spray (concentrate), outdoor treatment, outdoor premis e treatment, animal treatment (pour-on), animal treatment (ear tag), mound drench, soil treatmen t (T-banding), soil in-furrow treatment, conservation tillage, mound treatment, band treatment, dip treatment, and bark

treatment.

Both lambda -cyhalothrin and gamma -cyhalothrin have uses on cat tle and calves (beef and nonlactating). They are used “[F]or the control of lice and horn flies on beef cattle, cows and calves” (sample language from label 53883-248). In all instances, the products are formulated with piperonyl butoxide (PBO). A summary of th e use information for the three products for lambda

cyhalothrin appears in Table 3.3a . For lambda -cyhalothrin, there are two types of products: ear tags and pour on insecticides.

Table 3.3a. End Use Labels for Lambda -cyhalothrin for the Use on Cattle

Label (EPA Reg. No.) lambda

cyhalothrin Application
Method Max. App. Rate per Treatment No. of Apps. per Season Int. Between Applications

Saber® Extra Insecticide Ear Tags (773-75) 10% a.i. (plus 13%

PBO) Application tobeef and nonlactating cattle

and calves 9.5 g product per tag, 2 tags per head (~2.09x10 -4 lb a.i./ tag or 4.18x10 -4 lb a.i./ cattle) Not specified Not specified, effective for 4- 5 months

Ultra Saber Pour

On Insecticide (773-92) 1.0% a.i. (plus 5.0% PBO) Pour on application tobeef and nonlactating cattle

and calves 10-15 mL or 1⁄3 -1⁄2 fl oz/ cattle or up to approx. 3.13x10 -4
lb a.i./ cattle 4 per 6 month period 14 days

Lambda Pour On Plus or Cyonara

Plus Pour-On Topical Insecticide (53883-248) 1.0% a.i. (plus 5.0% PBO) Pour on application tobeef and nonlactating cattle

and calves 10-15 mL or 1⁄3 -1⁄2 fl oz/ cattle or up to approx. 3.13x10 -4
lb a.i./ cattle 4 per 6 month period 14 days

Table 3.3b provides equivalent information for gamma -cyhalothrin for the single product registered for use on cattle as a pour on insecticid e. A comparison of the pour on products with lambda -cyhalothrin indicates that th e proportion of PBO to active ingredient is higher for the product containing gamma -cyhalothrin.

Table 3.3b. End Use Label for Gamma -cyhalothrin for the Use on Cattle

Label (EPA Reg. No.) gamma
cyhalothrin Application
Method Max. App. Rate per Treatment No. of Apps. per Season Int. Between Applications
Gamma Pour On Plus or CSI

Gamma

Cyhalothrin Synergized Topical Insecticide Pour-On (53883-270) 0.5% a.i (plus 5.0% PBO) Pour on application tobeef and nonlactating cattle

and calves 10-15 mL or 1⁄3 -1⁄2 fl oz/ cattle or up to approx. 1.56x10 -4
lb a.i./ cattle 4 per 6 month period 14 days27 Figure 3.1 shows the cattle and cal ves inventory as of 2002. 5

Figure 3.1. Cattle and Calves Inventory as of 2002

The usage of lambda -cyhalothrin, from the Screening Level Usage Analysis (SLUA) is provided in Table 3.4a . The table is arranged in alphabetical orde r of crops. Accordi ng to the table, the major agricultural uses for lambda -cyhalothrin (crops for which ≥ 5,000 lb a.i. are applied), are alfalfa, corn, cotton, onions, rice, soybeans, sweet corn and wheat. Crops with relatively high percent crop treated ( ≥ 40%) include apricots, cabbage, lettuce, onions and sweet corn (maximum of 40, 45, 40, 55 and 60% crop treated, respectively). Both onion and sweet corn, which are the crops with the highest maximum percent cr op treated, are among the major crops (with ≥ 5,000 lb a.i., as identified above). For these crops, the average percent crop treated is also high, with 45 and 40%, respectively. According to the BEAD Chemical Profile for lambda -cyhalothrin, from 1998-2008, the largest markets in terms of total p ounds of active ingredient applied were cotton, soybeans, corn, alfalfa, winter wheat and rice.

5 Information obtained from the fo llowing website accessed 08/17/10: http://www.nass.usda.gov/research/atlas02/Livestock/Ca ttle/Cattle%20and%20Calves/Cattle%20and%20Calves%20- %20Inventory.gif28 Table 3.4a. Screening-Level Estimates of Agricultural Uses of Lambda -cyhalothrin (SLUA, dated 01/25/10). Percent Crop Treated Crop lb a.i. Avg. Max.

Alfalfa 20,000 5 10

Almonds 2,000 10 10

Apples 2,000 10 15
Apricots <500 10 40

Artichokes <500 5 5
Asparagus <500 <1 <2.5

Barley <500 10 10

Beans, Green 1,000 10 25

Broccoli 1,000 10 20
Cabbage 2,000 30 45
Canola/Rapeseed <500 <1 <2.5
Cantaloupes <500 <2.5 5

Carrots <500 <1 <2.5

Cauliflower <500 15 30
Celery <500 10 20

Cherries <500 5 15

Corn 20,000 <2.5 <2.5

Cotton 50,000 10 15

Cucumbers <500 5 10
Dry, Beans/Peas 1,000 <2.5 <2.5
Eggplant <500 15 15

Garlic <500 10 30
Hazelnuts, (Filberts) <500 5 10

Lettuce 4,000 30 40

Onions 5,000 45 55

Peaches 1,000 5 15

Peanuts 3,000 10 15

Pears 1,000 20 30

Peas, Green <500 <2.5 <2.5

Pecans <500 <2.5 5
Peppers <500 5 15

Potatoes <500 <1 <2.5

Prunes <500 <2.5 5
Pumpkins <500 5 1029 Table 3.4a. Screening-Level Estimates of Agricultural Uses of Lambda -cyhalothrin (SLUA, dated 01/25/10). Percent Crop Treated Crop lb a.i. Avg. Max.

Rice 10,000 15 25
Seed Crops (NPUD '02) <500 NC 25
Sod (NPUD '02) + <500 NC 5
Sorghum 2,000 <2.5 10
Soybeans 60,000 5 10
Spinach + <500 <2.5 5

Squash <500 <2.5 10

Strawberries + <500 <1 <2.5
Sugar Beets + <500 <1 <2.5

Sugarcane 1,000 5 10

Sunflowers 7,000 10 20

Sweet Corn 20,000 40 60

Tobacco <500 5 5

Tomatoes 3,000 20 25

Walnuts 1,000 5 10

Watermelons <500 <1 <2.5

Wheat 10,000 <2.5 <2.5 All numbers are rounded. '<500' indicates less than 50 0 pounds of active ingredient. '<2.5' indicates less than 2.5 percent of crop is treated. '<1' indicates less than 1 percent of crop is treated. ‘+’ Crops not known to be listed on active end use product registrations or as Section 18 emergency exemptions when the report was run. ‘N/C’ not calculated. The sources of the SLUA include the USDA-NASS, Private Pesticide Market Research, National Pesticide Use Database (N PUD 2002) of the CropLife America Foundation and California Department of Pesticide Regulation (CDPR) data. The information reflects amalgamated data developed by the Agency and are in a releasable format.

The usage of gamma -cyhalothrin, from the Screening Level Usage Analysis (SLUA) is provided in Table 3.4b . The table is also arranged in alphabetical order of crops. It appears that the major uses for gamma -cyhalothrin are soybeans and rice, with 3000 and 1000 lb a.i., respectively, but the percent crop treated is less than 2.5%. Se veral other uses show <500 lb a.i. each, which include major crops such as alfalfa, corn and cotton. The crop with the highest percent crop treated is apples with 5% (a verage) and 5% (maximum). A ccording to the BEAD Chemical Profile for gamma -cyhalothrin, from 2004-2008, the largest ma rkets in terms of total pounds of active ingredient applied were soybeans (more than half of th e pounds), alfalfa, rice, winter wheat, apples, and cotton.30 Table 3.4b. Screening-Level Estimates of Agricultural Uses of Gamma -cyhalothrin (SLUA, dated 01/25/10). Percent Crop Treated Crop lb a.i. Avg. Max.

Alfalfa <500 <1 <2.5

Almonds <500 <2.5 <2.5

Apples <500 5 5
Beans, Green <5 00 <1 <2.5

Broccoli <500 <2.5 <2.5
Cabbage <500 <1 <2.5

Corn <500 <1 <2.5

Cotton <500 <1 <2.5

Cucumbers + <5 00 <1 <2.5
Dry Beans/Peas <500 <1 <2.5

Lettuce <500 <2.5 <2.5

Onions <500 <2.5 5

Peaches <500 <1 <2.5

Peanuts <500 <1 <2.5

Pears <500 <2.5 <2.5

Pecans <500 <2.5 <2.5
Peppers <500 <1 <2.5

Rice 1,000 <2.5 <2.5

Tomatoes <500 <2.5 <2/5
Sorghum <500 <1 <2.5
Soybeans 3,000 <1 <2.5

Sunflowers <500 <1 <2.5

Sweet Corn <500 <1 <2.5

Wheat <500 <1 <2.5 All numbers are rounded. '<500' indicates less than 500 pounds of active ingredient. '<2.5' indicates less than 2.5 percent of crop is treated. '<1' indicates less than 1 percent of crop is treated. ‘+’ Crops not known to be listed on active end use product registrations or as Section 18 emergency exemptions when the report was run. The sources of the SLUA include the USDA-NASS, Private Pesticide Market Research, the National Pesticide Use Database (NPUD 2002) of the CropLife America Foundation and California Department of Pesticide Regulation (CDPR) data. Th e information reflects amalgamated data developed by the Agency and are in a releasable format.

According to the BEAD Chemical Profile for lambda -cyhalothrin, the states with the most agricultural usage in te rms of pounds active ingredient appl ied are Arkansas, Minnesota, North Carolina, Illinois, Louisiana, Texa s, Mississippi, and California. Th ese states are also the largest in terms of total acres treated from 1998-2008. The U.S. Geological Survey (USGS) pesticide agricultural use maps ( Fig. 3.2 ) show regional scale patterns in use intensity within the United31 States. The USGS pesticide maps are based on St ate level estimates of pesticide use rates for individual crops, which have been compiled by the National Center fo r Food and Agricultural Policy (NCFAP) for 1999 through 2004, and on the 2002 Census of Agriculture for county crop acreage crop. According to the map, the major agricultural uses for lambda -cyhalothrin are soybeans and cotton with 19.34 and 17.65% of the use, respectively. Thes e crops are followed by corn, sweet corn and rice with 10.57-13.32% of the use. Other crops with >1% of the use included alfalfa hay, wheat for grain, tomatoes, p eanuts and dry onions. As expected, there is a general agreement between the SLUA and the data in the USGS map. The map shows a generalized use of lambda -cyhalothrin for agricultural purpo ses throughout the country, with higher use towards the East of the country. It al so shows potential uses in estuarine/ marine regions of the US. Multiple agri cultural uses are approved for lambda -cyhalothrin, other than the ones in the map, as i ndicated above in the Table 3.2a

.

Fig. 3.2. Estimated Use of Lambda -cyhalothrin in 2002

Note of Caution: The pesticide use maps available ( http://water.usgs.gov/nawqa/pnsp/usage/maps/compound_listing.php?year=02 ) show the average annual pesticide use intensity expre ssed as average weight (in p ounds) of a pesticid e applied to each square mile of ag ricultural land in a county. The area of each map is ba sed on state-level estimates of pesticide use ra tes for individual crop s that were compiled b y the CropLife Foundation, Crop Protection Research Institute during based on information collected during 1999 through 2004 and on 2002 Censu s of Agriculture county crop acreage. The maps do not represent a specific year, but rather show typical use patterns over the five year period 1999 through 2004. Use intensity rates are expressed as the pounds applied per square mile of mapped agricultural land in a county. The area of mapped agricultural land for each county was obtained from an enhanced version of the 1992 USGS National Land Cove r Data (NLCD). The ke y limitations of the data used to produce these maps include the following: (1) state use coefficients represent an average for the entire state and consequently do not reflect the local variability of pesticide management practices found within states and counties, (2) pesticide use estimates are not for a speci fic year, but represent32 typical use patterns for the five year period, (3) state pesticide use coefficients may not have been available for all states where a pesticide may have been applied to agricultural land, and therefore, are not displayed on the maps, (4) the county crop acreage is based on the 20 02 Census of Agriculture and may not represent all crop acreage because of Census nondisclosure rules, and (5) agricultural land area used to calculate the pesticide use intensity and display the data was derived from 30-meter satellite remote sensing data that may over estimate or underestimate the actual agricultural land area. The maps are not intended for making local-scale estimates of pesticide use, such as estimates at the county level. Please refer to Method for Estimating Pesticide Use for a detailed discussion of how the pesticide use data were developed.

At the present time, there is no similar USGS agricultural use map for gamma -cyhalothrin.
However , according to the BEAD Chemical Profile for gamma -cyhalothrin, the states with the most agricultural usage in terms of “pounds ai applied” are Minnesota, S outh Dakota, Mississippi, Iowa, Colorado, and New York. The report also indicates that the us e has been steadily increasing from 2004 to 2008.

In addition to the classical agricultural use sites, lambda -cyhalothrin and gamma -cyhalothrin have multiple other non-agricultural uses. Lambda -cyhalothrin and gamma -cyhalothrin may also be used in multiple urban environments. Examples of uses that may be classified as outdoor residential include ornamental lawns and turf, recr eation area lawns, residential lawns and paths/ patios. Tables 3.5a and 3.5b provide a summary of the nonagric ultural (terrestrial or outdoor) use sites for lambda -cyhalothrin and gamma -cyhalothrin, respectively. Application methods vary (see above). Many of these uses could involve substantive exposure to wildlife, specifically, aquatic organisms, and they will be assessed accordingly ( e.g. , conifers - seed orchard, forest trees, commercial/ industrial lawns, residential lawn, golf course tu rf, ornamental lawns and turf, recreation area lawn and residential lawns). Note that there are fewer non-food uses for gamma

cyhalothrin than for lambda -cyhalothrin. For example, lambda -cyhalothrin has uses on nonagricultural rights-of-way/ fencerows/ hedgerows, but gamma -cyhalothrin does not have this use. Another use that will be evaluated is wood protection trea tment (outdoors).

Table 3.5a. Terrestrial Non-Food Uses for Lambda -cyhalothrin

Use Max. App. Rate/ units Max. No. Applications/
Year Max. App. Rate per

Year Min. App. Interval/

days agricultural rights-of-way/fencerows/ hedgerows 0.03 lb/A NS 0.08 lb 5 agricultural/farm premises .0033 lb 1K sq. ft. NS NS 21 agricultural/farm structures/buildings and equi pment stated in lb/1 gal NS .3594 lb/yr 7 airports/landing fields stated in lb/1 gal NS .3594 lb/yr 7 animal kennels/sleeping quarters (commerc ial) 0.0033 lb 1K sq. ft. NS NS 7, 21 automobiles, taxis, limousines, recreational vehicles, & tires stated in lb/1 gal NS .3594 lb/yr 7 commercial storages/warehouses premises stated in lb/1 gal NS .3594 lb/yr 7

commercial/industrial lawns 0.0032 lb/mound 0.0032 lb 1K sq. ft. NS, 6/yr Various NS, 7 commercial/institutional/industrial premises/equipment (outdoor) 0.0033 lb 1K sq. ft. NS NS, 0.3594 lb/yr 7, 21 conifers (seed orchard) 0.156 lb/A NS .5 lb/yr NS

eating establishments stated in lb/1 gal NS NS, 0.3594 lb/yr 7, 21 forest nursery plantings (for transpla nt purposes) 0.0416 lb/A NS 0.2496 lb/yr NS forest plantings (reforestati on programs)(tree farms, tree plantations, etc.) 0.0416 lb/A NS 0.2496 lb/yr NS forest trees (all or unspecified) 0.0416 lb/A NS 0.2496 lb/yr NS

forest trees (softwoods, conifers) 0.04 lb/A NS 0.24 lb/cc, 0.24 lb/yr NS golf course turf 0.0032 lb 1K sq. ft NS, 6/yr 0.36 lb/yr 7 grasses grown for seed 0.0784 lb/A 6/1 yr, NS .36 lb/yr NS, 7

household/domestic dwellings outdoor premises 0.0033 lb 1K sq. ft., 3.281E-04 lb/mound 6/yr, NS NS, 0.3594 lb/yr NS, 7, 21, 5633 Table 3.5a. Terrestrial Non-Food Uses for Lambda -cyhalothrin

Use Max. App. Rate/ units Max. No. Applications/
Year Max. App. Rate per

Year Min. App. Interval/

days nonagricultural outdoor buildings/structures 0.0019 lb sq. ft. 6/yr, NS NS, 0.36 lb/yr NS, 7

nonagricultural rights-of-way/fencerows/hedgerows 0.0150 lb linear ft NS NS, 0.3594 lb/yr NS, 7

nonagricultural uncultivated areas/soils 0.0033 lb 1K sq. ft., 0.0076 lb lin. ft/ft depth, 0.0038 lb linear ft. NS NS, 0.3594 lb/yr NS, 7, 21, AN

ornamental and/or shade trees 1.125E-04 lb/mound, 0.0018 lb 1K sq. ft. 6/yr, NS NS, 0.36 lb/yr NS, 7

ornamental grasses 0.0025 lb/mound, 0.0032 lb 1K sq. ft. NS NS, 0.3594 lb/yr 7

ornamental ground cover 0.0018 lb 1K sq. ft., 1.125E-04 lb/mound 6/yr, NS NS, 0.36 lb/yr NS, 7

ornamental herbaceous plants 0.0018 lb 1K sq. ft., 1.125E-04 lb/mound 6/yr, NS NS, 0.36 lb/yr NS, 7

ornamental lawns and turf 0.0030 lb 1K sq. ft., 6.563E-04 lb/mound 6/yr, 7/yr, NS NS, 0.41 lb/yr NS, 7

ornamental nonflowering plants 0.0018 lb/sq. ft., 1.125E-04 lb/mound 6/yr, NS NS, 0.36 lb/yr NS, 7

ornamental sod farm (turf) 0.0032 lb/sq. ft., 0.0025 lb/mound 6/yr, NS NS, 0.36 lb/yr NS, 7

ornamental woody shrubs and vines 0.0018 lb/sq. ft., 1.125E-04 lb/mound 6/yr, NS NS, 0.36 lb/yr NS, 7 paths/patios 0.0033 lb 1K sq. ft. NS NS, 0.36 lb/yr 7, 21

recreation area lawns 0.0032 lb 1K sq. ft., 0.0032 lb/mound 6/yr, NS NS, 0.4117 lb/yr NS, 7

residential lawns 0.0032 lb 1K sq. ft., 0.0032 lb/mound 6/yr, NS NS, 0.4117 lb/yr NS, 7 seed orchard trees 0.0042 lb/tree NS 0.52 lb/yr NS wide area/general outdoor treatment (public hea lth use) 0.0032 lb 1K sq. ft. NS .3594 lb/yr 7

wood protection treatment to buildings/products outdoor 0.0075 lb 1K sq. ft., 0.015 lb lin. ft/ft depth NS NS NS NS = Not Specified; AN = As Needed; cc = crop cycle. Data obtained from LUIS Report.

Table 3.5b. Terrestrial Non-Food Uses for Gamma -cyhalothrin

Use Max. App. Rate/ units Max. No. Applications/
Year Max. App. Rate per

Year Min. App. Interval/

days agricultural/farm premises 0.0081 lb 1K sq. ft. NS NS 21, AN, NS agricultural/farm structures/buildings and e quipment 0.0081 lb 1K sq. ft. NS NS NS, 21 airports/landing fields 0.0016 lb 1K sq. ft. NS NS NS, AN animal kennels/sleeping quarters (commercial) 0.0081 lb 1K sq. ft. NS NS 21, AN, NS automobiles, taxis, limousines, re creational vehicles, & tires 0.0026 lb 1K sq. ft. NS NS 21, AN, NS christmas tree plantations 0.02 lb/A NS 0.12 lb/yr NS commercial storages/warehouses premises 0.0079 lb 1K sq. ft. NS NS 21, AN, NS

commercial/industrial lawns 0.0625 lb/A, 0.0079 lb 1K sq. ft.,

0.0016 lb/mound NS 0.1641 lb/yr, NS NS, 7, 30 commercial/institutional/industrial premises/equipment (outdoor) 0.0016 lb/mound NS NS AN, NS

conifers (seed orchard) 0.0781 lb/A 0.0020 lb/tree NS, 3 cc 0.25 lb/yr, NS NS, 7 eating establishments 0.0016 lb 1K sq. ft. NS NS 21, AN, NS forest trees (all or unspecified) .0200 lb/A NS 0.12 lb/yr NS

forest trees (softwoods, conifers) .0200 lb/A 3/cc 0.1203 lb/yr, NS 7, NS34 Table 3.5b. Terrestrial Non-Food Uses for Gamma -cyhalothrin

Use Max. App. Rate/ units Max. No. Applications/
Year Max. App. Rate per

Year Min. App. Interval/

days

golf course turf 0.0015 lb 1K sq. ft., 0.0016 lb/mound NS NS, 0.1641 lb/yr 7, AN

household/domestic dwellings outdoor premises 0.021 lb 1K sq. ft., 1.635E-04 lb/mound NS, 6/yr NS NS, 60, AN nonagricultural areas (public health use) 0.0126 lb 1K sq. ft. NS NS NS, AN nonagricultural outdoor buildings/structures 0.0079 lb 1K sq. ft NS NS NS, AN nonagricultural rights-of-way/fencerows/hedgero ws 0.0016 lb 1K sq. ft NS NS NS, AN nonagricultural uncultivated areas/soils 0.0026 lb 1K sq. ft NS NS NS, AN

ornamental and/or shade trees 0.0625 lb/A, 0.0015 lb 1K sq. ft.,

0.0016 lb/mound NS 0.1641 lb/yr, NS 7, 30, NS, AN

ornamental ground cover 0.0625 lb/A, 0.0015 lb 1K sq. ft.,

0.0016 lb/mound NS 0.1641 lb/yr, NS 7, 30, AN

ornamental herbaceous plants 0.0625 lb/A, 0.0015 lb 1K sq. ft.,

0.0016 lb/mound NS 0.1641 lb/yr,
NS 7, 30, NS, AN

ornamental lawns and turf 0.0625 lb/A, 0.0421 lb 1K sq. ft.,

0.0016 lb/mound NS, 7/yr, 14/yr 0.1641 lb/yr, NS 7, NS, 21, 30, AN

ornamental nonflowering plants 0.0625 lb/A, 0.0015 lb 1K sq. ft.,

0.0016 lb/mound NS 0.1641 lb/yr, NS 7, 30, NS

ornamental sod farm (turf) 0.0015 lb 1K sq. ft., 0.0016 lb/mound NS 0.1641 lb/yr 7, AN

ornamental woody shrubs and vines 0.0625 lb/A, 0.0015 lb 1K sq. ft.,

0.0016 lb/mound NS 0.1641 lb/yr, NS 7, 30, NS, AN paths/patios 0.0016 lb 1K sq. ft. NS NS NS, AN pet living/sleeping quarters 0.0079 lb 1K sq. ft. NS NS NS

recreation area lawns 0.0015 lb 1K sq. ft., 0.0016 lb/mound NS 0.1641 lb/yr, NS 7, AN

recreational areas 0.0625 lb/A, 0.0016 lb/mound NS 0.1641 lb/yr 7, 30 refuse/solid waste sites (outdoor) 0.0081 lb 1K sq. ft. NS NS 21

residential lawns 0.0625 lb/A, 0.0015 lb 1K sq. ft.,

0.0016 lb/mound NS, 6/yr 0.1641 lb/yr,
NS 7, 30, NS, AN sewage disposal areas 0.0016 lb 1K sq. ft. NS NS NS, AN wood protection treatment to buildings/products outdoor 0.0043 lb 1K sq. ft. NS NS NS NS = Not Specified; AN = As Needed; cc = crop cycle. Data obtained from LUIS Report.

In addition, there are several other indoor non-food or indoor re sidential use sites for both lambda -cyhalothrin and gamma -cyhalothrin, like for example, commercial storage/ warehouse premises, commercial/ institutional/ industr ial premises/ equipment (indoor), eating establishments, food stores/ markets/ supermar kets premises, hospitals/ medical institutions premises (human/ veterinarian), household/ domesti c dwellings and pet livi ng/ sleeping quarters. Lambda -cyhalothrin and gamma -cyhalothrin also have greenhouse uses.

For the indoor uses, the Division has conducte d environmental risk assessments for a few chemicals (such as permethrin, resmethrin a nd pyrethrins) for Re-registration Eligibility Decisions. In one study (Weston and Lydy 2010), several synthetic pyr ethroids were observed in effluents after secondary treatmen t from POTWs in the Sacramento -San Joaquin Delta. In the study, bifenthrin was the most fre quently detected pyrethroid. Lambda -cyhalothrin was found in35 17% of the municipal wastewater treatment plan t effluents (POTWs) tested in the SacramentoSan Joaquin Delta (18 samples tested), at a ma ximum concentration of 5.5 ng/L, and it exceeded the Hyalella azteca EC 50 of 2.3 ng/L in 17% of the samples. There is the potential for synthetic pyrethroids to reach surface waters via exposur e from contaminated drains, and even after treatment in plants (POTWs) (for fu rther information about this study, see Appendix B ). EFED will evaluate the potential for exposure to aquatic organisms from the indoor uses of lambda

cyhalothrin and gamma -cyhalothrin in the final ecological risk assessment (see Section 6

. Conceptual Model, and Section 7 , Analysis Plan for further details).

Toxicity data on environmental mixtures of lambda -cyhalothrin and gamma -cyhalothrin with other pesticides may be presented, if available, as part of the ecological ri sk assessment. It is expected that the toxic effect of lambda -cyhalothrin and gamma -cyhalothrin, in combination with other pesticides used in the environment, is lik ely to be a function of many factors including but not necessarily limited to: (1) the exposed species, (2) the co-contaminants in the mixture, (3) the ratio of lambda -cyhalothrin or gamma -cyhalothrin and co-contamin ant concentrations, (4) differences in the pattern and duration of expos ure among contaminants, and (5) the differential effects of other physical/ chemical char acteristics of the receiving waters ( e.g. organic matter present in sediment and suspended water). Quan titatively predicting the combined effects of all these variables on mixture toxicity to any given taxa with confid ence is beyond the capabilities of the available data and methodologies. However, a discussion of implications of the available pesticide mixture effects data regarding the confidence of risk assessment conclusions will be addressed as part of the uncertainty analysis . EFED will consider open literature, currently available models and other lines-of-evidence ( e.g. , monitoring data), as available to address the potential for cumulative effects of pyrethroids in the risk descri ption of the ecological assessment for lambda - and gamma -cyhalothrin.

Piperonyl butoxide (PBO) and M GK-264 are commonly used in form ulations with pyrethroids. PBO acts as a potentiator in both mammals and in sects because the pyrethr oid is not metabolized and excreted as quickly in its presence (B arile 2004; Hodgson & Smart 2001). Exposure to pyrethroids along with PBO increases the toxic ity of the pyrethroids (Amweg & Weston 2007; Weston & Lydy 2010). MGK-264, another potentiato r/synergist used with pyrethroids, has similar effects as those observed for piperonyl butoxide (Hodgson & Smart 2001).

A total of 4 active product registrations exist for lambda -cyhalothrin and gamma -cyhalothrin formulations with PBO:

• Lambda -cyhalothrin and PBO: # 773-75, #773-92, #53883-248

• Gamma -cyhalothrin and PBO: # 53883-270

The registrations are for cattle ear tags ( #773-75) or cattle pour-on treatments (#773-92, #53883- 248 and #53883-270). (See discussion above and Tables 3.3a and b .).

Lambda -cyhalothrin and gamma -cyhalothrin are not co-formu lated with MGK-264 in any currently active registrations.36 The Agency routinely assesses po tential exposure to formulations by examining acute exposure to spray drift or direct applications to water. Toxi city data may be also requested if there is any indication that a formulated produc t may be more toxic than the te chnical grade active ingredient. Acute toxicity data on the formulation containing PBO will be compared to estimated exposure of runoff resulting from cattle pour-on treatments.

PBO and/or MGK-264 from other pyrethroid ap plications ( e.g. the application of an adulticide containing PBO), could interact with lambda -cyhalothrin and gamma -cyhalothrin in the environment. Available literature data also sugge st the potential for synergism in the environment (Amweg et al. 2006, Weston et al. 2006). Therefore, potential intera ctions will be discussed in the risk assessment. EPA is evaluating options fo r gathering and designing studies that would improve the evaluation of pyrethroid end use products co-formulated with a synergist.

3.3. Environmental Fate and Transport

Cyhalothrin (PP563) is a racemic mixtur e that consists of four isomers (1R, cis

, Z -S’; 1S, cis

, Z -R’; 1R, cis

, Z -R’; and 1S, cis

, Z -S’); while lambda -cyhalothrin (PP321) is a ra cemic mixture that consist of two of the isomers pr esent in cyhalothrin (1R, cis

, Z -S’ and 1S, cis

, Z -R’). Greater than 98% of

gamma -cyhalothrin (XDE-225 or XR-225) is th e biologically ac tive enantiomer (1R, cis

, Z -S’) (please, refer to further discussion in Section 3 ).

Table 3.6 summarizes the environmental fate/transport properties of lambda -cyhalothrin and

gamma -cyhalothrin. For information about the phys icochemical properties of these compounds, refer to Table 3.1b

.37 Table 3.6. Summary of environmental fate parameters for lambda - and gamma -cyhalothrin

Lambda -cyhalothrin Gamma -cyhalothrin Parameters Value Source Value Source Hydrolysis T 1/2 pH 5 stable pH 7 stable pH 9 13 days 00151604 (S) Rate exceeded the limit of solubility. pH 5 stable pH 7 relatively stable pH 9 2.5 days*
N atural river water 26.8 days* 45447409 (pH 5, 7, A) (pH 9, U, upgradable) *River water and pH 9
T 1/2 values are of high uncertainty. Aqueous Photolysis (pH 5) T 1/2 Reviewer calculated linear half-lives: 29.5 days* (phenyl label) 36.9 days* (cyclopropyl) 44861501 (U) *Halflives are uncertain. Test substance did not remain in solution throughout the study. 8.2 days (cyclopropyl) 8.3 days (phenoxy label) 8.6 days (combined lab) 13 days (environmental phototransformation T 1/2 ) 46394702 (A)

Soil Photolysis T 1/2 Fairly stable loam, only 13-16% degraded after

ca. 35 days. Compound II was a minor product. 40052405 (A) Not Available Not Available

Aerobic Soil Metabolism
T 1/2 T 1/2 46.2 days sandy loam Reported DT 50 31, 55, 26 days sandy loam 102 days loamy sand *12.2 days loam 14.5 days silt loam (CS formulation Warrior T; purity 11.8% a.i.) [** For cypermethrin: 24 days clay loam, 73 d. loamy coarse sand, 42 days fen peat] 00151607 & 44861504 (A) [ For cyhalothrin:
DT 50 26, 48 days SL 83 days loamy sand ] *45447410 (S)

[** 00089995 (A) Cypermethrin tested to provide info on alcohol moiety] 28.2 days sandy loam 36.9 days silt loam

*32.5 days loam 51.5 days silt loam (CS formulation GF-231; purity 14.8% a.i.) 45447411 (S) [+ For cyhalothrin: 46.8 days sandy loam 60.5 days - silt loam ] *45447410 (S)

Anaerobic Soil Metabolism
T 1/2 Aerobic 30 days, then flooded, T 1/2 = 30 days sandy loam cyhalothrin; flooded DT 50 110 days for cyhalothrin; 107 days for lambda -cyhalothrin 00151607 & 44861504 (A) Not Available Not Available

Aerobic aquatic metabolism T 1/2 21.1 days sand 34.1 days sandy loam
52.9 days loam (123.8 days silty clay –
T 1/2 is of limited value) 44861506 (A)

44367402 (S) Silty clay sediment: 40.1 days - total system 41.0 days - in sediment <3 days - water column (Extrapolated values) 45447412 (S)

Anaerobic aquatic metabolism T 1/2 142 days silty clay 44367401 (S) Not Available Not Available

Soil Partition Coefficient (K d in mL/g)

Mean K d ( lambda

cyhalothrin) = 4,350 mL/g

Mean K d ( gamma
cyhalothrin) = 622 mL/g Sandy Loam 3810 Loamy Sand 1970 Silty Clay Loam 5880 Loamy Sand 2100 Silty Clay Loam 4490 Sandy Loam 6890 Sandy Loam 7610 Loamy Sand 3470 Sand 2400 Sandy Loam 4870 44861503 (A) Loamy Sand 672, Sandy Loam 751, Silty Loam 826, Sandy Loam 239

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

Loamy Sand 555, Sandy Loam 601, Silty Loam 630, Sandy Loam 355 45447413 (S)

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

These values are for cyhalothrin, which was tested along with

g amma -cyhalothrin.38 Table 3.6. Summary of environmental fate parameters for lambda - and gamma -cyhalothrin

Lambda -cyhalothrin Gamma -cyhalothrin Parameters Value Source Value Source

Soil Partition Coefficient (K OC in mL/g OC )

Mean K OC ( lambda

cyhalothrin) = 333,200 mL/g OC

Mean K OC ( gamma
cyhalothrin) = 59,700 mL/g OC Sandy Loam 346,000 Loamy Sand 200,000 Silty Clay Loam 298,000 Loamy Sand 724,000 Silty Clay Loam 209,000 Sandy Loam 270,000 Sandy Loam 305,000 Loamy Sand 352,000 Sand 518,000 Sandy Loam 110,000 44861503 (A) Loamy Sand 34133, Sandy Loam 92692, Silty Loam 69952, Sandy Loam 41932

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

Loamy Sand 28176, Sandy Loam 74212, Silty Loam 53345, Sandy Loam 62242 45447413 (S)

--------------------------- These values are for cyhalothrin, which was tested along with

g amma -cyhalothrin. Mean = 54,500 Aged Adsorption/ Desorption In aged batch equilibrium study (up to 8 weeks of incubation in darkness at 4 and 20°C, sandy loam),
≥ 97.6% of the applied radioactivity remained adsorbed after 24 hr of equilibration. However, it was >80% for soil incubated under ambient light and subject to wet/ dry cycles. 44861509 (S) Not Available Not Available

Column Leaching The aged (30 days) residues of cyhalothrin and lambda

cyhalothrin were immobile in two soil columns (loamy sand and sandy loam). All residues were wthin the upper 0-5 cm soil depth. 00151608 (A, partial) Not Available Not Available

Terrestrial Field Dissipation T 1/2 IL Clay Loam 33 days (~18-21% AR remained at 279 days) MS Silty Loam 12 days In IL & MS most of the AR in the 0-5 & 5-10 cm depth (1 lb/gal EC 14 CPP321, 2 labels). 40052407 (A) MS Silty Loam 15.6 days 45794902 (A) CA Loam 29.5 days All residues in the 0-15 cm soil depth. GF-231 CS; 14.8% a.i.

Aquatic Field Dissipation
T 1/2 MS (rice) 0.4-1.8 days CA (rice) 1.0-1.8 days (T 1/2 from water, no data on soil/ sediment) 44367403 (S) 44367404 (S) Artificial pond Not Available Not Available

Dissipation in Aquatic Microcosm T 1/2 17 hours water layer, 34 hours total system 44861508 (S) (water pH 9.83) Not Available Not Available

Bioaccumulation in Fish Cyhalothrin: 4600x whole fish (carp); DT 50 ~9 days depuration. 77-79% of the radioactivity eliminated after 28 days. ~50-70% of the residues were cyhalothrin and ~10-19% was Compound Ia. Cypermethrin: Benzyl label: 111x edible; 468x whole fish; 579X non-edible; 83- 87% depurate after 21 days.
DT 50 ~1.2 days for depuration. mPBacid was ~7% in edible tissue. 00152744, 00152745 (A)

42868203 (A) [Cypermethrin: provided information about the alcohol moiety] Not Available Not Available39 Lambda -cyhalothrin and gamma -cyhalothrin are Type II synthetic pyrethroids (they are cyano substituted in the alpha position). They have a 2-chloro-3,3,3-trifluoropropenyl group and they are 2,2-dimethyl substituted in the cyclopropane ring. The envi ronmental fate database for lambda -cyhalothrin is substantially complete, but it contains various suppl emental studies. The database for gamma -cyhalothrin is smaller and it consists mostly of supplemental studies, but it was largely supplemented with data from lambda -cyhalothrin. All studies on gamma -cyhalothrin were considered supplemental, except for th e terrestrial field di ssipation study. Both lambda

cyhalothrin and gamma -cyhalothrin show very low solubilities ( ≤ 5.0 ppb). They are hydrophobic compounds and their octanol/ water pa rtition coefficients are high (log K OW ≥ 4.96). Based on their octanol/water partition coefficient, they would be predicted to be hightly bioaccumulative (which appears to be confirmed by the bioaccumula tion in fish study, see further details below). Volatilization from moist or dry surfaces is not e xpected to be an important transport process, since both chemicals have relatively low vapor pressures and Henry’ s Law constants (see Section 3 for further details). Furthermore, lambda -cyhalothrin and gamma -cyhalothrin readily bind to soils or partition with suspended matter and sedi ment. Thus, potential volatilization would be greatly reduced.

Based on a combination of data for lambda -cyhalothrin and gamma -cyhalothrin, it is concluded that they are moderately persistent in the e nvironment and degrade slowly through a combination of biotic and abiotic mechanisms. Lambda -cyhalohrin and gamma -cyhalothrin are stable to relatively stable in acidic and ne utral water, but hydrol yze in a matter of se veral days to weeks under alkaline conditions (half-life 13 days for lambda -cyhalothrin at pH 9). Lambda -cyhalothrin and gamma -cyhalothrin are more stable to light than the first or second generation pyrethroids like, for example, allethrin and resmethrin, but s till undergo some photolysis in water, with halflives of several weeks in water (h alf-life 13 environmental days for gamma -cyhalothrin). It appears that the alpha -cyano group stabilizes somewhat th e molecules and they do not undergo photolysis readily. On soil, lambda -cyhalothrin is fairly stable (w ith very little degradation on the order of only ~13% in 35 days). Under both aerobic and anaerobic soil metabolism conditions, cyhalothrin, lambda -cyhalothrin and gamma -cyhalothrin biodegrade at moderate rates, with comparable half-lives of several weeks. Various aerobic soil studies availa ble with all three test substances, which included even additional capsule suspension formulated studies, corroborate that the rates of aerobic transformation is simila r for these chemicals (ra nge of aerobi c soil halflives is 28.2-60.5 days out of five stud ies). In aquatic metabolism conditions, lambda -cyhalothrin and gamma -cyhalothrin may biodegrade at moderate rate s under aerobic conditi on, with half-lives on the order of about 21-53 days (aerobic, bot h chemicals), but more slowly under anaerobic condition, with a half-life of 142 days ( lambda -cyhalothrin only). Terrestrial field dissipation studies confirm the results observe d in the laboratory, indicating th at a combination of biotic and abiotic mechanisms of dissipation take place. Half-lives of 12-33 days were observed in the field for both lambda -cyhalothrin and gamma -cyhalothrin, with the majority of the residues remaining in the uppermost soil layer. Due to their low mob ility observed in laboratory studies and in the field, both chemicals are expected to have little mobility on soil surfaces and, therefore, leaching into groundwater is not expected to be an important environmental fate process. However, despite the protective imposed buffer zone and ve getated buffer strip, they could reach adjacent surface waters via spray drift or runoff events acc ompanied by erosion. In aquatic environments,40 these chemicals will partition with the sediment and will linger for long periods of time (several months). The sediments coul d serve as re positories of lambda -cyhalothrin and gamma

cyhalothrin in dynamic equilibrium with the pore water and with the su rface water, occurring after numerous applications. Lambda -cyhalothrin and gamma -cyhalothrin are highly bioaccumulative (~4,600x), based on a study performed with cyhalothrin, and they depurate at moderately slow rates (~9 days). There is the potential for bioaccumulation and biomagnification to take place. Willis and McDowe ll (1987) indicate that for synt hetic pyrethroids with similar structure to that of lambda -cyhalothrin and gamma -cyhalothrin, dissipation from plant foliage occurs with half-lives on the or der of 5-6 days, but it may be highe r for the total residues. A low rate of volatilization was observe d from leaves (88% of applied remaining on the leaves after 24 hours). 6 The chemical does not tran slocate in the plant tissue.

Abiotic Degradation Both, lambda -cyhalothrin and gamma -cyhalothrin have an ester moie ty that is expected to be susceptible to hydrolysis (particula rly at high pHs). This behavior is confirmed in the hydrolysis studies, where both lambda -cyhalothrin and gamma -cyhalothrin are fairly stable in pH 5 and pH 7 buffered solutions. In pH 9 solution, lambda -cyhalothrin degraded with a half-life of 13 days (however, the pH 9 part of the study conducted with gamma -cyhalothrin was considered highly uncertain, and the study conducted with lambda -cyhalothrin was conducte d at a rate that exceeded the solubility limit). (1 RS )- cis -3( ZE )-2-chloro-3,3,3-triflu ro-1-propenyl)-2,2- dimethylcylopropane-carboxylate (Compound Ia, ma ximum 68% AR at 30 days) was the major metabolite observed in the lambda -cyhalothrin study. Even though ther e is a reported half-life for

gamma -cyhalothrin at pH 9, it was not considered in this assessment; however, in the study, two major metabolites were observed. For gamma -cyhalothrin, at pH 9, the major early degradate observed was 3-phenoxybenzaldehyde (Compound IV , maximum 55.6% AR at 2 days), followed by subsequent oxidation into 3-phenoxybenzoid acid (Compo und V or 3-PBA, maximum 54.6% AR at 30 days).

Upon aqueous photolysis (pH 5), gamma -cyhalothrin showed a half-life of 13 environmental days. This half-life was consider ed representative for both chemical s. The half-life of 30-37 days observed in the study conducted with lambda -cyhalothrin was not considered accurate because there was evidence of precipitati on in the study. Aquatic photolys is appears to be a moderate route of dissipation for these chemicals when co mpared to other soil, sediment, and water halflives. In the new chemical review of gamma -cyhalothrin, and considering the registrant’s bridging plan, the aqueous photol ysis study was not requested, si nce aqueous photolysis is not expected to be enantioselective (although it was submitted and found acceptable). For the assessment it was assumed that the gamma -cyhalothrin photodegradation rate is comparable to that of lambda -cyhalothrin. It is worth noting that for aqueous photolysis, the relative contribution of this route of degradation in su rface water modeling and the environment is not expected to be significant. Lambda -cyhalothrin and gamma -cyhalothrin’s high soil binding affinity and the limited light penetration into most water bodies greatly reduce the potential for aqueous photodegradation. Nonethel ess, both studies coincided with respect to the identity of the metabolites. Compounds Ia and Ib were a ma ximum of 13.7 and 7.1% AR, respectively in the

6 European Commission Review Report for the Active Substa nce Lambda-Cyhalothrin, 7572/VI/97-final; Jan 25, 200141 study with lambda -cyhalothrin. Unspecified compounds Ia and Ib were a maximum of 45.0% AR in the study with gamma -cyhalothrin. The other metabolite identified was Compound V, which was a maximum of 25.0-42.0% AR (both chemicals).

Upon soil photodegradation, lambda -cyhalothrin appeared to be persistent through the testing period. Only 13-16% of the applied lambda -cyhalothrin degraded after ca. 35 days. Compound V was a minor product in the study. Gamma -cyhalothrin is expected to show a similar photolytic behavior on soils.

Metabolism Several aerobic soil metabolism studies were identified for cyhalothrin, lambda -cyhalothrin and

gamma -cyhalothrin. Among the studies, half-lives were in the relatively narrow range of 28.2- 60.5 days (5 half-lives, observed in three soils and three test substa nces). Further, the registrant conducted aerobic soil metabolism studies with lambda -cyhalothrin and gamma -cyhalothrin in capsule suspension (CS) formula tion in order to evaluate whet her encapsulating would increase the persistence of the test substances relative to the technical material. For lambda -cyhalothrin, the half-lives were 12.2 and 14.5 days and for gamma -cyhalothrin, the half-lives were 32.5 and 51.5 days, for a loam and a silt loam, respectively. The CS half-lives will not be considered in assessment because they represent other additional processes which are not related to metabolism, but they generally also indicate th at the aerobic soil half-lives are of the same order of magnitude for both chemicals and relatively comparable. Degradation of gamma -cyhalothrin in aerobic soil appears to occur in a similar ma nner to that of cyhalothrin and lambda -cyhalothrin. The studies submitted for bridging purposes do not provide an indication of those soil properties that may increase or decrease the rate of degradation. However, the degrad ates observed in the aerobic soil metabolism studies for lambda -cyhalothrin and gamma -cyhalothrin ( e.g. , hydroxylated products) suggest that the type and activity of soil microbes could affect the rate of lambda -cyhalothrin and

gamma -cyhalothrin degradation. Hydroxylation at the para -carbon of the phenoxy ring of lambda -cyhalothrin and gamma -cyhalothrin appears to yiel d 3-(2-chloro-3,3,3-trifluoro-1- propenyl)-2,2-dimethyl-cyclopropanecar boxylic acid cyano[3-(4-hydroxyphenoxy) phenyl]methyl ester (Compound XV, 12.5% at 63 days for lambda -cyhalothrin). Compound XV and the parent compound can yield 3-(4- hydroxyphenoxy)-benzaldehyde and Compound V, respectively, following ester cleavage, and lo ss of the cyano group. Further oxidation and hydrolysis reactions presumably result in th e ultimate formation of carbon dioxide (CO 2 ). In aerobic soil metabolism st udy of technical product gamma -cyhalothrin the major degradation product was 3-(4-hydroxyphenoxy )-benzaldehyde (maximum 12.2% AR at 17 days). Other metabolites were only minor (<10% AR).

One anaerobic soil metabolism study conducted on c yhalothrin was identified in this assessment. The half dissipation time was roughly 30 days, af ter which the degradation appeared to proceed much slower. Due to the limited numb er of data points in the study, the DT 50 was considered highly uncertain. After reaching natural water bodies, lambda -cyhalothrin and gamma

cyhalothrin will partition to dissolved organic ma terial, suspended solids, and sediment. Four aerobic aquatic metabolism studies were id entified in this assessment (three for lambda

cyhalothrin and one for gamma -cyhalothrin). The half-lives were in the range of 21.1 to 52.942 days for lambda -cyhalothrin and it was 40.1 days for gamma -cyhalothrin, indicating that both test substances degrade with similar rates under the te st conditions. In the ae robic aquatic metabolism study, gamma -cyhalothrin dissipated from the water la yer very rapidly and was detected at ≤ 4.5% AR at any sampling interval from time zero through 30 days posttreatment. The first measurement of gamma -cyhalothrin in the disso lved phase on day 0 of the study was 3.7% of applied material. On day 14 the dissolved level ha d decreased to 1.8% of the applied material. In the sediment gamma -cyhalothrin degraded with an extrapol ated half-life of 41 days. The end products of the aeroibic aquatic process are cons istent with those observed in the aerobic soil metabolism study. One of the products appears to be Compound V (16.0% AR at 30 days for lambda -cyhalothrin and 26.9% AR at 30 days for one replicate in the gamma -cyhalothrin study) and Compound Ia (22.0% AR at 30 days for gamma -cyhalothrin). Compound XV was a minor product. Under anaerobic aquatic conditions, lambda -cyhalothrin appears to be more stable than under aerobic condition. For a single study, the anaerobic aquatic metabolism half-life was 142 days. Consistent with the other metabolism studies, the major metabolites were Compound 1a and Compound V.

Mobility In an acceptable study, for lambda -cyhalothrin, the K d values ranged from 1970 to 6890 mL/g and the K OC values ranged from 110,000 to 518,000 mL/g OC (10 soils were tested, immobile according to FAO mobility classi fication, FAO 2000). It is note d that this study was conducted with sterile soils. Gamma -cyhalothrin simple K d values ranged from 239 to 826 mL/g, while for cyhalothrin (teste d concurrently) K d values ranged from 355-601 mL/g. For gamma -cyhalothrin the corresponding K OC values ranged from 34,133 to 92,692 mL/g OC (hardly mobile as per FAO 2000) for all tested soils and for cyhalothrin K OC values were 28,176 -74,212 mL/g OC (hardly mobile, FAO 2000). Just as for cyhalothrin and lambda -cyhalothrin there was no linear relationship between the soil or ganic carbon content and the K d values for different soils for

gamma -cyhalothrin. Because K d values were obtained only at one concentration, the Freundlich adsorption/desorption coefficients could not be calculated for gamma -cyhalothrin or for cyhalothrin. However, the data suggest that gamma -cyhalothrin, similar to cyhalothrin and lambda -cyhalothrin, is expected to be largely immobile in soil and water environments with settled sediment. The bulk of lambda -cyhalothrin and gamma -cyhalothrin transport would most likely occur with movement of so il as erosion in runoff and suspe nded sediment in lotic (moving) water bodies.

In a soil column study (two soils tested: loamy sand and sandy loam), aged (30 days) lambda

cyhalothrin’s residues remained mostly in the uppermost soil layer (0-5 cm). Residues were characterized as immobile. In a supplemental study, lambda -cyhalothrin was aged for up to 8 weeks in darkness at 4 and 20°C in a sandy loam. The soil was then equilibrated in a batch equilibrium-type study for 24 hours. It was found that ≥ 97.6% AR remained adsorbed to the soil. In the same study, another sample of sandy lo am soil was incubated under ambient light and subject to wet/ dry cycles. In this latter instance ≥ 80% AR remained in the soil after equilibration.

Field Dissipation43 Lambda -cyhalothrin and gamma -cyhalothrin appear to be immobile and moderately persistent in laboratory studies and in th e field environment. It is highly unlikely that lambda -cyhalothrin and

gamma -cyhalothrin will reach ground water resources due to their high soil adsorption affinity.
For lambda -cyhalothrin, two terrestrial field dissipation studies indicated half -lives of 33 days (IL) and 12 days (MS). The test substance remain ed mostly in the uppermost layers of soil (0-5 and 5-10 cm). Gamma -cyhalothrin was not detected belo w the 0-15 cm soil depth, with the exception of a single detection below the LOQ (0.010 μg/g) at 4 days post-treatment in the 15-30 cm soil depth in MS site. Gamma -cyhalothrin dissipation half-lives were similar to those of lambda -cyhalothrin with 15.6 days (MS) and 29.5 days (CA). Because the capsule suspension formulation might be expected to behave di fferently in the environment compared to nonencapsulated formulations, a terrestria l field dissipation study using the gamma -cyhalothrin capsule suspension (CS) was conduc ted. In the terrestrial field dissipation study conducted with lambda -cyhalothrin, transformation products monitored at the two sites were re ported to be at low levels (<7%). Field soil samples were not analyzed for transformation products in the gamma

cyhalothrin study. The study authors stated that gamma -cyhalothrin was the only residue of environmental concern because the major degradates are fully and rapidly mineralized in soil and water, do not leach, and are formed via the det oxification process of es ter cleavage. In two supplemental aquatic field dissipation studies conducted on rice pl ots in MS and CA, lambda

cyhalothrin appeared to dissipa te rapidly from the water (hal f-lives were 0.4-1.8 days in the water); however the studies did offer suitable information about the dissipation of the chemical from the soil/sediment.

As indicated earlier, lambda -cyhalothrin and gamma -cyhalothrin will likely reach surface waters via soil erosion and particulate runoff after rain fall, and via spray drift during or shortly after application. A published report measured 73% to 90% of synthetic pyrethroids are bound to eroding sediment in runoff (Liu et al. , 2004). The major routes of lambda -cyhalothrin and

gamma -cyhalothrin transport and dissipat ion are binding to soil particles (K OC values 110,000 to 518,000 in an acceptable study), degradation through ab iotic processes in alkaline environments (at pH 9.0 t 1/2 =13 days), and through biotic proce sses via aerobic soil metabolism (t 1/2 =28.2-60.5 days) and aerobic aquatic metabolism (t 1/2 =21.1-52.9 days in total system). It appears that in acidic or anaerobic environments, lambda -cyhalothrin and gamma -cyhalothrin would be more persistent.

Bioaccumulation in Fish In a study performed with cyhalothrin, the chem ical appears to be hi ghly bioaccumulative (4,600x in the whole fish), but it depurates at moderately slow rates (depuration t 1/2 about 9 days). It appears that situations may occur, wh ere this test substance, as well and lambda -cyhalothrin and

gamma -cyhalothrin, may persist in fish tissue for ex tended periods of time. Compound Ia was up to 22% in muscle and viscera. In a study pe rformed with cypermethrin, which provided some information on the alcohol moiety of lambda -cyhalothrin and gamma -cyhalothrin, around 7% was Compound V in the edible tissue.

Table 3.7a provides a summary of the data on the occurrence of th e transformation products of lambda -cyhalothrin and gamma -cyhalothrin.44 Table 3.7a. Summary of degradate formation for lambda -cyhalothrin & gamma -cyhalothrin
DEGRADATE and MAXIMUM CONCENTRATION (% of the applied)

STUDY TYPE Compound Ia 7 and/ or Compound Ib 8 Compound IV 9 Compound V 10 Metabolite XV 11 Hydrolysis (1) Lambda -cyhalothrin : (at pH 9, Ia 68% at 30 days) Gamma -cyhalothrin : (at pH 9, 55.6%, 2 days) Gamma -cyhalothrin : (at pH 9, 54.6%, 30 days) Gamma -cyhalothrin : (river water, 21.6%, 30 days) Aqueous Photolysis (1) Lambda -cyhalothrin : (Ia 13.7% at 31 days) (cyclopropane ring) (Ib 7.1% at 31 days) (cyclopropane ring)
Gamma -cyhalothrin : (unspecified 45.0% at 21 days) Lambda -cyhalothrin : Minor product Lambda -cyhalothrin : (25.0% at 31 days)
Gamma -cyhalothrin : (42.0% at 15 days)

Soil Photolysis Lambda -cyhalothrin : Minor product Aerobic Soil Metabolism (2) Lambda -cyhalothrin : Minor product Cypermethrin : Minor product Cypermethrin : Minor product
Gamma -cyhalothrin : Minor product Lambda -cyhalothrin : (12.5% at 63 days)
Gamma -cyhalothrin : Minor product
Anaerobic Soil Metabolism Lambda -cyhalothrin : Ia 10.8% at 30 days postflooding. Lambda -cyhalothrin : 11.1% at time of flooding (30 days) Aerobic Aquatic Metabolism Lambda -cyhalothrin : Ia 11.4% in the water

and 10.6% in the sediment of the SL sediment system at 30

days (total 22.0%). Lambda -cyhalothrin : Minor product
Gamma -cyhalothrin : (14.4% in sediment, 16.0% in total system at 30 days, last interval) Lambda -cyhalothrin : Minor product.

Anaerobic Aquatic Metabolism Lambda -cyhalothrin : Ia 0.023 ppm at 365

days water; 0.008 ppm at 182 days soil (information was not provided as percent of the applied) Lambda -cyhalothrin : 0.010 ppm at 91 days in water; 0.039 ppm at 120 days in soil (information

was not provided as percent of the applied) Lambda -cyhalothrin : Minor product.

Degradation in Aquatic Microcosm (3) Lambda -cyhalothrin : Ia 40.6% at 4 days in water; it was minor in the sediment Bioaccumulation in Fish (4) Lambda -cyhalothrin : Ia 22% in mucle and viscera Cypermethrin : Detected Cypermethrin : ~7% in edible tissue

7 (1 RS )-cis-3( ZE )-2-chloro-3,3,3-trifluro-1-propenyl)-2,2-dimethylcylopropanecarboxylate.

8 (1 RS )-trans-3-( ZE )-2-chloro-3,3,3-trifluoroprop-1-enyl)-2,2-dimethylcyclopropane-carboxylic acid.

9 3-phenoxybenzaldehyde

10 3-PBA or 3-phenoxybenzoic acid

11 (1 R ) cis α -( S ) cis α -( R ) α -cyano-3-(4-hydroxyphenoxy) benzyl 3-(Z-2-chloro-3,3,3-trifluoroprop-1-enyl)-2,2- dimethylcyclopropanecarboxylate.45 Table 3.7a. Summary of degradate formation for lambda -cyhalothrin & gamma -cyhalothrin
DEGRADATE and MAXIMUM CONCENTRATION (% of the applied)

STUDY TYPE Compound Ia 7 and/ or Compound Ib 8 Compound IV 9 Compound V 10 Metabolite XV 11 (1). Hydrolysis: Isomerization was rapid in the pH 9 solution and moderate in pH 7 solution. It did not occur in the pH 5 solu tion. Isomerization also occurred in the aqueous photolysis study. (2). 3-(4-Hydroxyphenoxy)-benzaldehyde was a major product in the sandy loam (12.2% at 17 days, gamma -cyhalothrin study). (3). In the TFD study conducted with lambda -cyhalothrin, transformation products monitored at the two sites were reported to be at low levels (<7%). In the study conducted with gamma -cyhalothrin no transformation products were monitored. (4). In the cypermethrin study, 3-phenoxyb enzyl alcohol (mPBalc) was also detected.

The Compounds Ia [(1 RS )- cis -3-( ZE )-2-chloro-3,3,3-trifluoroprop-1-enyl)-2,2- dimethylcyclopropane-carboxylic acid] (and possibly Ib, the trans -isomer), and Compound IV (3- phenoxybenzaldehyde) are the expected result of the hydrolysis of the ester linkage of the pyrethroid structure, followed by loss of the cyano group. However, in general, the major degradates appear to be Compounds Ia and Ib, and Compound V (3- phenoxybenzoic acid, also named 3-PBA, m-PBA, 3-PBAc or 3-PBacid), which were observed mostly in the metabolism studies. It appears that Compound IV oxidizes quickly to Compound V in metabolic environments. The findings in the field corr oborate the laboratory predictions. Compound V shows relatively hi gh mobility, with K OC values 118-215 mL/g OC and K F values ≤ 3.11 mL/g (moderately mobile according to FAO mobility cla ssification, three soils tested, while for a sand soil, the K FOC could not be determined b ecause of the low sorption) ( Table 3.7b ).

Ring-hydroxylated lambda -cyhalothrin, (1 R ) cis α -( S ) cis α -( R ) α -cyano-3-(4-hydroxyphenoxy) benzyl 3-(Z-2-chloro-3,3,3-trifluoroprop- 1-enyl)-2,2-dimethylcyclopropanecarboxylate (Compound XV), formed in aerobic soil microbial de gradation (12% of the applied at 63 days post-treatment) appears to degrad e readily to carbon dioxide in a separate aerobic soil metabolism study, and it appears to partition with soils and se diments. Its solubility is only 9 ppb (WSKOW SAR modeling), similar to the pa rent compound, which is not surpri sing due to their structural similarity. It also has low mobility based on the estimated K OC value of 770,900 mL/g OC , from structure activity relationship (SAR) modeling. The aerobic soil metabol ism linear half-lives (t 1/2 s) for Compound XV ranged from 13.9 to 17.4 days (three soils tested, Table 3.7b ). The potential for groundwater contaminat ion with the degradate is low. However, it has the potential to reach surface water via runoff (in erodible particles), after rainfall events.

Table 3.7b summarizes the available environmental fate/transport proper ties of Compounds V and XV, which are relevant metabolites of lambda -cyhalothrin and gamma -cyhalothrin.46 Table 3.7b. Summary of Environmental Fa te Parameters for Compounds V and XV

Parameters Value Source
Soil Partition Coefficient Compound V (3-PBA) (K F in mL/g) Not Determined Sand 3.11 Silt Loam 0.98 Sandy Loam 1 2.44 Sandy Loam 2 43424901 (S) [Reported Freundlich correlations were good (r 2 close to unity), but n values were around 1.5 (or 1/n of around 0.7).]
Soil Partition Coefficient Compound V (3-PBA) (K FOC in mL/g OC ) Not Determined Sand 122 Silt Loam 118 Sandy Loam 1 215 Sandy Loam 2 43424901 (S) [See note above.]

Solubility of Compound XV 0.009 ppm or 9 ppb

- - - - - (reported as <0.01 ppm in a study) Estimated from log K OW (SAR; WSKOW v1.40)
44861505 Aerobic Soil Metabolism for Compound XV , T 1/2 Sandy clay loam 13.9 days Loamy sand 14.7 days Sandy Loam 17.4 days 44861505 (S) Reviewer calculated first order log-linear half-lives. Three UK soils tested.
Soil Partition Coefficient for Compound XV (K OC in mL/g OC ) 770,900 SAR Modeling

There are multiple articles in the open literatur e that document the occurrence and behavior (which pertains to Section 3.3 ) and as well as the ecotoxi city (which pertains to Section 4.1 ) of synthetic pyrethroids such as lambda -cyhalothrin and gamma -cyhalothrin in the environment. Particularly, there has been recent concern for th e toxicity of pyrethroids to sediments dwelling organisms. For a summary of selected li terature articles, please, refer to the Appendix B

.

4. Receptors

4.1. Aquatic and Terrestrial Effects

The receptor is the biological entity th at is exposed to the stressor (EPA, 1998). Due to the outdoor uses of lambda -cyhalothrin and gamma -cyhalothrin, the types of receptors that may be exposed include both aquatic and terrestrial receptors, such as birds, reptiles, mammals, amphibians, freshwater and estuarine/marine fis h, non-target terrestrial & aquatic invertebrates and terrestrial & aquatic plants. This list may not be comprehensive. Spray drift and runoff exposures are expected for both gr ound and aerial applications of lambda -cyhalothrin and

gamma -cyhalothrin. Consistent with the process described in th e Overview Document (USEPA, 2004), this risk assessment uses a surrogate species approach in its evaluation of lambda

cyhalothrin and gamma -cyhalothrin. Toxicological data gene rated from surrogate test species, which are intended to be repres entative of broad taxonomic groups , are used to extrapolate to potential effects on a variety of species (receptors) included under these taxonomic groupings.

Tables 4.1, 4.2, 4.3 and 4.4 provide a summary of the taxon omic groups and the surrogate species tested to help understa nd potential acute ecol ogical effects of pes ticides to these nontarget taxonomic groups. In addition, the tables provide a preliminary overview of the potential acute toxicity of lambda -cyhalothrin and gamma -cyhalothrin, by providi ng the acute toxicity47 classifications.

Terrestrial Species – Lambda Cyhalothrin Birds The available toxicity data suggests that lambda -cyhalothrin appears to be practically non-toxic to slightly toxic on an acute basis to avian species. A mallard duck ( Anas platyrynchos ) acute oral
LD 50 >3950 mg ai/kg bw (MRID 00151594, acceptable). In this study, no mortalities were observed in the controls or at any of the five tr eatment level tested (739-3 950 mg ai/kg bw). In an 8-day dietary study with mallard duck, the LC 50 = 3948 (2868-7602) mg ai/ kg diet, and sublethal effects included subdued behavi or and unsteadiness in the 203 0-5040 mg ai/kg diet treatment levels (MRID 00151595, acceptable). In an 8-da y dietary study with bobwhite quail ( Colinus virginianus ), the LC 50 > 5300 mg ai/kg diet because there wa s only one mortality per 10 birds in each of the 577, 1020, 3040 and 5300 mg ai/kg diet trea tment levels (no control mortality). No sublethal effects were observed at any le vel during the test (MRID 00151596, acceptable).

No data have been submitted to evaluate lambda -cyhalothrin acute toxicity to passerine species of birds.

Three tests were submitted to examine the chronic effects of cyhalothrin (not lambda -cyhalothrin

or gamma -cyhalothrin) 12 on avian species. Two chronic studies with mallard ducks have been submitted. The most sensitive test resulted in a NOAEL = 5 ppm and LOAEL = 50 ppm based on a statistically significant reduction in the number of eggs laid and eggs set when compared to control birds. Postmortem examin ation of test birds showed evid ence of aggressive behavior (bruising and missing feat hers) and underdeveloped ovaries in all treatment levels (5 and 50 ppm) (MRID 00153504, supplemental). The study was classifi ed as supplemental because the raw data were not included in the study re port and the NOAEL may potentiall y be less than 5 ppm if an adequate statistical review could be conducte d. In the other chronic mallard duck test, the NOAEL= 30 ppm and LOAEL > 30 ppm based on no st atistically significant adverse effects on hatchling body weight, eggshell thickness, food consumption or body weight. Pathological results showed an increase in egg yolk peritonitis in all treatment groups (5-30 ppm) when compared to the control birds. A residue analysis of the egg, li ver and fat tissue of the test birds showed that lambda -cyhalothrin primarily accumulates in the fat tissue, but there was no increase in concentrations over the cour se of the study (MRID 41512101, supplemental). The study was designated as supplemental because the test bi rds were sharing a room with another avian reproductive test for hexaconazole, and the study authors shared the control birds for these two tests. In a reproductive study with bobwhite qua il, the NOAEL was determined to be 50 ppm and LOAEL was greater than 50 ppm due to no statitistically signi ficant adverse effects on the number of eggs laid, eggs cracked, eggs set, viable embryos, normal hatchlings and 14-day survivors at the highest treatment level te sted (MRID 00153505, acceptable). Effects noted during the postmortem examination of this test include u nderdeveloped ovaries and testes, blotchy livers, no eggs in developed oviduct and egg bi nding at levels as low as 5 ppm.

12 Note: As indicated previously, cyhalothrin consists of four enantiomers out of the 16 possibilities in its structure; lambda -cyhalothrin consists of two of those isomers, while gamma -cyhalothrin consists of a single isomer.48 While all three avian reproduction studies are on cyhalothrin, cyhalo thrin showed similar chronic toxicity to lambda -cyhalothrin and gamma -cyhalothrin in submitted mammalian data – see Lambda -Cyhalothrin and Gamma -Cyhalothrin Human Health Assessment Scoping Document in Support of Registration Review, D379544). In addition, the different isomeric mixtures present in lambda -cyhalothrin and gamma -cyhalothrin have similar acute avian toxicity. In the risk assessment, the cyhalothrin avian reproductive en dpoints will be used to calculate chronic risk quotients for birds.

Mammals The mammalian toxicity profiles for the cyhalothrins are similar. Lambda -cyhalothrin is categorized as moderately toxic to mammals on an acute oral ba sis based on studies conducted on rats (most sensitive acute LD 50 = 56 mg a.i./kg bw, MRID 00259805) . In the 90-day rat studies,

gamma -cyhalothrin, lambda -cyhalothrin, and cyhalothrin te chnical had similar NOAELs (50 ppm), however, more severe effects were seen at a lower dose with gamma -cyhalothrin (mortality and neuromuscular effects at the LOAEL of 10 0 ppm) than with cyhalothrin (decreased body weight/body weight gain at the LOAEL of 250 ppm) and lambda -cyhalothrin (decreased body weight gain, food consumption and food e fficiency at the LOAEL of 250 ppm) ( Lambda

Cyhalothrin and Gamma -Cyhalothrin Human Health Assessm ent Scoping Document in Support of Registration Review, D379544).

For mammalian toxicity, EFED will coordinate with HED to determine the most sensitive endpoints for acute and chronic studies.

Terrestrial Invertebrates Acute contact and oral studi es were conducted with both lambda -cyhalothrin technical and the formulated product (Karate, 5.04% active i ngredient) (MRID 40052409, acceptable). Both the technical grade active ingredient and the formulat ed product were highly t oxic to honey bees. For lambda -cyhalothrin technical, the 48-hour contact LD 50 = 0.038 μg ai/bee and the 48-hour oral
LD 50 = 0.909 μg ai/bee. For the lambda -cyhalothrin formulated pr oduct, the 48-hour contact LD 50 = 0.098 μg ai/bee and the 48-hour oral LD 50 = 0.483 μg ai/bee. A foliar residue study was also conducted with a lambda -cyhalothrin formulated product The LT 50 was between 4 and 12 hours at the 0.013 lbs a.i./acre applica tion rate and 23 hours at 0.031 lb s ai/acre, also indicating high toxicity to nontarget terrestrial invertebrates. The time to no-effect, based on mortality, was 24-48 hours at the lower application rate , and greater than 96 hours at th e higher application rate (MRID 40436302). In another submitted study (that fulfills no guideline), lambda -cyhalothrin was applied at rates of 7.5 g a.i./hectacre and 15 g a.i./hectare to winter wheat with simulated honeydew (sprayed sucrose solution). Honeybee foraging was inhibited for up to three days compared to control conditions, and there was no significant increase in mortality at these treatment levels when compar ed to controls (MRID 40436303).49 Table 4.1 Summary of most sensitive endpoints fr om submitted terrestrial toxicity studies for lambda -cyhalothrin.

Species

(common

name) Taxa Represented Endpoint Concentration Test Substance

(% a.i.) MRID Acute Toxicity Classification

LD 50 56 mg/kg bw 92.6-96 00259805 Moderately

NOAEL 10 mg ai/kg/day Rattus norvegicus

(Laboratory Rat) Mammals

LOAEL 15 mg ai/kg/day 89.3 00154800 Not Applicable

LD 50 >3950 mg ai/kg bw 96 00151594

Acceptable Practically non-toxic

LC 50 3948 mg ai/kg diet 96.5 00151595

Acceptable Slightly toxic

NOAEC 5 ppm 1 Anas platyrynchos (Mallard duck) Birds, terrestrialphase amphibians, and reptiles

LOAEC 50 ppm 92

(cyhalothrin) 00153504

Supplemental Not Applicable

Apis mellifera

(Honey bee) Terrestrial invertebrates Contact
LD 50 0.038 μg/bee 96 40052409

Acceptable Highly toxic

1 Adequate statistical analysis could not be performed because raw data was not included in the study report. Therefore, some uncertainty exists for this endpoint but it is currently the most sensitive study available.

Terrestrial Species – Gamma Cyhalothrin

Birds The registrant has submitted two studies evaluating the acute effects of gamma -cyhalothrin on birds following oral dosing of the chemical. Both studies were conducted with the bobwhite quail ( Colinus virginianus ). The study conducted on the techni cal grade active ingredient (100%) resulted in an LD 50 greater than 2000 mg a.i./kg bw duri ng a 14-day observation period, based on mortality (MRID 45447210, acceptable). Decreased body weight and food consumption were observed in the treatment birds on days 0-3 compared to the control, but th ese difference were not observed on days 7 and 14. In another study with a formulated product (XR-225, 14.7% a.i.), the
LD 50 was also greater than 2000 mg a.i./kg bw during a 14-day observation period, based on mortality (MRID 45447211, acceptable). Food consump tion in the 1400 and 2000 mg a.i./kg bw50 treatment group was significantly lower on days 0- 3 compared to the control. However, these differences were not observed on days 7 and 14. No significant effects on bodyweight were observed during the study. All dos ed groups displayed head twitc hing behavior indicative of intoxication during the firs t two days of the study.

No data have been submitted to evaluate gamma -cyhalothrin acute toxicity to passerine species of birds.

Two avian 8-day dietary studi es have been conducted on gamma -cyhalothrin technical. In the dietary study with the mallard duck, after 5 days on treated diets, there were 20 and 40% mortality in the 2400 and 4430 mg a.i./kg diet treatment groups, respectively. The controls and other treatment groups had no mortalities. There were significant reductions in body weight change for all treatment groups during the exposure period. Food consumption decreas ed as the treatment concentrations increased during the test period. The food consumption improved over the recovery period. The sublethal effects of ataxia , swollen/weepy right ey es, and/or hyporeactivity were observed in the 933, 1430, 2400, and 4430 mg a.i./kg diet treatment groups. The gross pathological findings observed in the 2400 and 4430 mg a.i./kg diet treatment groups were emaciation, lesion/growth on intestin es, and/or discoloration of in ternal organs. The 8-day acute dietary LC 50 was >4430 mg a.i./kg diet. The NOAEC was <617 mg a.i./kg diet, based on reductions in body weight (MRID 45447213, acceptabl e). In a dietary study with the bobwhite, quail, after 5 days on treated diets, there was 10, 10, 30, and 90% mortality in the 933, 1430, 2400, and 4430 mg a.i./kg diet treatment groups, re spectively. The controls and 617 mg a.i./kg diet treatment group had no mortal ities. Significant reductions in body weight change for all treatment groups occurred during the exposure pe riod and these reductions were not apparent during the recovery period. F ood consumption decreased as the treatment concentrations increased during the test peri od. The food consumption improved over the recovery period. The sublethal effects of ataxia, hyporeactivity, and moribundity were observed in the 1430, 2400, and 4430 mg a.i./kg diet treatment gr oups. No significant gross pathol ogical findings were observed. The 8-day acute dietary LC 50 was 2794 mg a.i./kg diet (MRID 45447212, acceptable).

Three tests were submitted to examine the chronic effects of cyhalothrin (not lambda -cyhalothrin

or gamma -cyhalothrin) on avian species. See the disc ussion of the submitted cyhalothrin avian reproduction studies in the bird section for lambda -cyhalothrin above, and summary in Table 4.2.

Terrestrial Invertebrates Acute contact and oral studi es were conducted with both gamma -cyhalothrin technical and a formulated product (GF-231, 14.7% active ingredie nt). For the acute contact study conducted on the technical product, the LD 50 value was 0.0061 μg a.i./bee. Subl ethal effects (lethargy and live animals on their backs) were observed in all treatment groups (0.0013 – 0.080 μg a.i./bee). As a result, gamma -cyhalothrin technical is categorized as hi ghly toxic to honeybe es on a contact basis (MRID 45464802, acceptable). In the acute oral honeybee study submitted for the technical product, all concentrations we re reported in nominal valu es. Measurements of actual concentrations were not conducted, and stock so lutions (prepared in 500 g/L sucrose solutions)51 are likely to have exceed ed the solubility limit of gamma- cyhalothrin, making estimated exposure values questionable and inva lidating the study for use in risk assessment (MRID 45447408).

In another submitted study, the honey bee, Apis mellifera , was exposed to a 14.7% gamma

cyhalothrin formulation (GF-231) for 48 hour s in an acute cont act test (MRID 45464803). Sublethal effects (lethargy and/ or live animals on their backs) were observed in all treatment groups (0.0063 – 0.10 μg GF-23 l/bee) during the study. The LD 50 value was 0.030 μg GF231/bee equal to an LD 50 of 4.4 ng a.i./bee for gamma -cyhalothrin. As a result, the gamma

cyhalothrin formulation (GF-231) is categorized as highly toxic to honeybees on a contact basis. This study was categorized as supplemental, as onl y nominal concentrations were reported. In an acute oral study with a gamma -cyhalothrin formulation (GF-2 31), honeybees were exposed to diluted in sucrose water for 48 hours, at nomin al concentrations of 0.625 – 10 μg GF-23l/bee (actual ingested doses averaged 0.601 – 4.88 μg GF-231/bee). By 48 hours, mortality ranged from 10 to l00%, and the LD 50 value was 1.259 μg GF-231/bee, equal to an LD 50 of 0.185 μg a.i./bee for gamma -cyhalothrin. As a result, the gamma -cyhalothrin formulation (GF-231) is categorized as highly toxic to honeybees on an acute oral ba sis. This acute oral study is classified as supplemental, as it is a non-guideline study.

A honey bee toxicity study with 14.7% gamma -cyhalothrin formulation (GF-231) residues on foliage has also been submitted to the Agency (MRID 45464805). The alfalfa foliage was exposed to GF-231 at an application rate of 17 g a.i./ha and weathered for 3, 6, and 24 hours. The honeybees were exposed to the weathered foliage for 24 hours. There was 0% bee mortality in the control and all treatment groups (exposure to 3, 6, and 24 hour-old residues), and no signs of toxicity were observed during the study. Leaves were not chemica lly analyzed to determine the actual residue concentrations, so this foliar residue study is classified as supplemental.

Table 4.2 Summary of most sensitive endpoints fr om submitted terrestrial toxicity studies for

gamma -cyhalothrin.

Species

(common

name) Taxa Represented Endpoint Concentration Test Substance

(% a.i.) MRID Acute Toxicity Classification

LD 50 >2000 mg ai/kg bw 100 and 14.7 45447210, 45447211

Acceptable Practically non-toxic Colinus virginianus (Bobwhite

quail)

LC 50 2794 mg ai/kg diet 100 45447212

Acceptable Slightly toxic

Anas platyrynchos Birds, terrestrialphase amphibians, and reptiles

NOAEC 5 ppm 1 92 00153504 Not Applicable52 Table 4.2 Summary of most sensitive endpoints fr om submitted terrestrial toxicity studies for

gamma -cyhalothrin.

Species

(common

name) Taxa Represented Endpoint Concentration Test Substance

(% a.i.) MRID Acute Toxicity Classification

(Mallard duck)
LOAEC 50 ppm (cyhalothrin) Supplemental

Apis mellifera

(Honey bee) Terrestrial invertebrates Contact
LD 50 4.4 ng a.i./bee 48 45464803

Supplemental Highly toxic

1 Adequate statistical analysis could not be performed because raw data was not included in the study report. Therefore, some uncertainty exists for this endpoint but it is currently the most sensitive study available.

Aquatic Species

Freshwater Fish

Lambda -cyhalothrin technical is ve ry highly toxic to freshwat er fish, with a 96-hour LC 50 range from 0.078 μg a.i./L to 0.240 μg a.i./L in submitted acute toxicity tests (MRIDs 00151598, 00151601, 43908812, 00151597, 00151600, 43908813, 00153506; Tables 4.3 and A.1 ). The most sensitive species in the submitted acute toxicity tests is golden orfe ( Leuciscus idus) . In this study, the NOAEC value was 0.055 μg ai/L based on mortality and sublethal effects. Sublethal effects (quiescent, sounding, erratic swimming, sp iraling, loss of balance, rapid respiration, labored respiration, ceas ed swimming, light discoloration, su rfacing, irregular respiration, gulping air) were observed in the groups exposed to time -weighted average concen trations as low as 0.11 μg ai/L of lambda -cyhalothrin (MRID 00153506, supplemental because not a preferred test species). In other submit ted toxicity tests with lambda -cyhalothrin technical, the most sensitive endpoints for standard test species are a 96-hour LC 50 = 0.240 μg a.i./L for coldwater rainbow trout ( Oncorhynchus mykiss ) (MRID 00151597, acceptable) and a 96-hour LC 50 = 0.210 μg a.i./L for warmwater bluegill sunfish ( Lepomis macrochirus ) (MRID 00151598, acceptable).

For lambda -cyhalothrin formulated products (either 12.9 or 23.7 % active ingredient), the 96-hour LC 50 ranged from 1.2 to 3.4 μg ai/L (MRIDs 0015601, 43908812, 00151600 and 43908813, all acceptable).

A chronic full life cycle freshwater fish study for lambda -cyhalothrin techni cal resulted in a NOAEC of 0.031 μg a.i./L and LOAEC of 0.062 μg a.i./L for fathead minnow ( Pimephales promelas ) based on reduced growth in adult (F0) and o ffspring (F1), as well as offspring survival (MRID 41519001, supplemental). This study was determined to be supplemental because of numerous factors including low-le vel contamination in the solven t and negative controls, use of lower number of eggs than guideline recommenda tions, and other guidelin e deviations. It is53 worthy to note that the NOAEC of 0.031 μg a.i./L is only about a factor of two less than the 96-h LC 50 of 0.078 μg a.i./L for the golden orfe for lambda -cyhalothrin and virtua lly identical to the 96-h LC50 of 0.029 μg a.i./L for bluegill with gamma -cyhalothrin (MRID 45447215).

Fewer toxicity data for fish are available for gamma -cyhalothrin ( Tables 4.4 and A.1 ). Specifically, 96-h LC 50 values determined with the TGAI ar e available for two species of fish range from 0.029 μg a.i./L (bluegill, MRID 45447215) to 0.19 μg a.i./L for rainbow trout (MRID 45447217). In the bluegill study, fish were expos ed to mean-measured concentrations of <5 (LOQ, negative and solvent controls ), 7.74, 12.4, 20.2, 38.1, 60.3, and 105 ng/L under flow through conditions. After 96 hours of exposure, mortality was 10, 10, 20, 60, 90, and 100% in the 7.74, 12.4, 20.2, 38.1, 60.3, and 105 ng/L treatment groups, respectively. The LC 50 (29 ng/L or 0.029 ug/L) was calculated using the solvent control (0% mortality) since the negative control had 20% mortality on the last day of the study. This deviation, along with the use of fish with mean weight less than the 0.5 to 5g guideline recomm endation, resulted in its classification as supplemental. The NOAEC for sublethal eff ects was 0.0077 ug/L based on lethargy and loss of equilibrium.

For gamma -cyhalothrin, a 96-hour LC 50 of 1.1 μg ai/L (14.7% a.i.; MRID 45447218) was determined for bluegill which approximates the low end of the range of LC 50 values described earlier for lambda -cyhalothrin (1.2 to 2.2 μg ai/L).

Regarding the comparative toxicity of lambda - and gamma- cyhalothrin, bluegill appear somewhat more sensitive to gamma- cyhalothrin (TGAI) on an acute toxi city basis (i.e., about 4X more sensitive based on species mean LC 50 values of 0.16 and 0.04 μg ai/L for lambda and gamma

cyhalothrin, respectively). However, rai nbow trout appear similarly sensitve to lambda - and

gamma -cyhalothrin TGAI ( i.e. , within a factor of 2X; Table A.1 ).

No freshwater fish chronic toxicity data for were submitted for gamma -cyhalothrin.

Estuarine/Marine Fish

For lambda- cyhalothrin, estuarine/marine fish ar e represented by th e sheepshead minnow ( Cyprinodon variegatues ). Acute toxicity studies indicates that lambda -cyhalothrin technical is very highly toxic to estuarine/marine fish, with an LC 50 = 0.81 μg a.i./L (MRID 00153506, acceptable). A lambda -cyhalothrin early life-stage test was conducted with sheepshead minnow ( Cyprinodon variegatus ). The NOAEC = 0.25 μg a.i./L and the LOAEC = 0.38 μg a.i./L based on effects to larval growth (MRID 00152732). This study was initially determined to be supplemental because fewer than the recommended number of 80 eggs were used per treatment, raw data were not provided for statistical analys is and the measured concentrations of the test material were only 20 to 64% of the nominal va lues. Subsequently, this study was upgraded to “core/acceptable” upon submission of further information from the registrant.

For gamma -cyhalothrin, no acute or chronic toxicity data were submitted for estuarine/marine fish.54 Freshwater Invertebrates

Acute toxicity values for daphnids suggest that lambda -cyhalothrin technical is very highly toxic to freshwater invertebrates. The most sensitive 96-hour EC 50 = 0.0067 μg a.i./L with the amphipod Gammarus pulex (MRID 00152730, supplemental). This test was classified as supplemental because Gammarus pulex is not the guideline test species (typically Daphnia

magna ), the raw data were not included in th e study report, and cal culation of the EC 50 required extrapolation for exposure estimates of the th ree lowest treatment levels because test concentrations were below the level of detection (2.3 ng a.i./L). Several Daphnia magna studies were submitted for lambda -cyhalothrin technical and formul ated products. The daphnid 48-hour EC 50 for the technical product is 0.24 μg a. i./L (MRID 00151599, acceptable), and the studies conducted with formulated products containing 5.5- 24 % active ingredient resulted in slightly more sensitive EC 50 s ranging from 0.04 to 0.18 μg a. i./L (MRIDs 00151602, supplemental and 43908811, acceptable).

Two daphnid life cycle studies were submitted for lambda -cyhalothrin. In the most sensitive daphnid chronic life-cycle test, the NOAEC = 0.0002 μg a.i./L and the LOAEC = 0.0035 μg a.i./L based on adverse effects to # of young/female a nd total young at mean-meas ured concentrations in static renewal conditions (MRID 41217501, suppl emental). This study was classified as supplemental because only the healthiest organisms in the source population were chosen for the test and there were only two repl icates at each treatment level. Exposure concentrations also varied substantially within a treatment (appr oximately 3x), such that maximum and minimum values overlapped among treatments. Another daphnid life cycle submitted earlier by the registrant resulted in a NOAEC = 0.0004 μg a.i. /L and the LOAEC = 0.005 μg a.i./L based on adverse effects to # of young/female at mean-meas ured concentrations in flow-through conditions (MRID 00152733, supplemental). The study was classifi ed as supplemental because the measured concentrations varied greatly thr oughout the course of the test (from 3x to 10x), so much that the treatment levels overlapped in their exposure concentrations. A lthough this study is considered supplemental, EFED is requesting an additional fres hwater invertebrate life cycle test due to the high uncertainty caused by the ove rlapping test concentrations on interpretation of the study results and the extreme chronic sensitivity of daphnia (and aquatic invetebr ates in general) to lambda -cyhalothrin (i.e., NOAEC values below 1 ng/L).

Similar to lambda- cyhalothrin, gamma- cyhalothrin is very highly toxi c to freshwater invertebrates is indicated by an 96-h LC50 valu e of 0.00048 ug/L for the amphipid, Gammarus pseudolimnaeus . However, this study was classified as supplemental due to problems in the study with rapidly declining test con centrations occurred over the dura tion of the study, thus suggesting that a more accurate LC 50 value would be lower. The high sensitivity of Gammarus to lambda and gamma -cyhalothrin is consistent with sensitivity trends observed for other pyrethroids for which amphipods were found to be among the most se nsitive freshwater inve rtebrates. To address uncertainties in the acute toxicity endpoi nts with freshwater invertebrates for both lambda and

gamma -cyhalothrin, an additional acute toxicity study with a freshwater amphipod is being requested for gamma -cyhalothrin.55 No acute or chronic freshwater invertebrate studies were submitted for gamma -cyhalothrin.

Estuarine/Marine Invertebrates

Estuarine/marine aquatic invertebrates are represented by the mysid shrimp ( Mysidopsis bahia ) and eastern oyster ( Crassostrea virginica ). Submitted toxicity studies indicate that lambda

cyhalothrin is very highly toxic to crustaceans and pr actically nontoxic to bi valves. In an acute study with mysid shrimp, the 96-hour LC 50 = 0.0041 μg a.i./L for lambda -cyhalothrin technical (MRID 00152728). In a study with the eastern oyster, the 96-hour EC 50 >590 μg a.i./L for lambda -cyhalothrin technical (MRID 00152728). A chronic estuarine/marine study with estuarine/marine invertebrates has also been submitted for lambda -cyhalothrin technical. The NOAEC = 0.0002 μg a.i./L and LOAEC = 0.0005 μg a.i. /L based on reductions in the number of young per reproductive day and number of young per treatment (Accesion #073989, acceptable).

No acute or chronic estuarine/marine invertebrate studies were submitted for gamma -cyhalothrin.

Table 4.3. Summary of most sensitive endpoints from submitted aqua tic toxicity studies for lambda -cyhalothrin.

Species

(common name) Taxa Represented Endpoint Duration (hours) Mean concentration

(μg a.i./L) Citation

MRID Acute Toxicity Classification

Leuciscus idus (Golden orfe) LC 50 96 0.078 00153506
Supplemental Highly toxic

NOAEC 0.031 Pimephales promelas
(Fathead Minnow) Freshwater fishand aquaticphase amphibians LOAEC 60 (days) 0.062 41519001

Supplemental NA

Gammarus pulex (amphipod) EC 50 48 0.007 00152730

Supplemental Very highly toxic

NOAEC 0.0020 Daphnia magna

(Water Flea) Freshwater Invertebrates

LOAEC 21 (days) 0.0035 41217501

Supplemental NA

LC 50 96 0.807 00153506

Supplemental Very highly toxic

NOAEC 0.25 Cyprinodon variegatus (Sheepshead

minnow) Estuarine/ Marine Fish

LOAEC 28 (days) 0.38 00152732

Supplemental NA

LC 50 96 0.0041 00152728

Acceptable Very highly toxic Mysidopsis bahia

(Mysid shrimp) Estuarine/ Marine Invertebrates

NOAEC 28 (days) 0.0002 Acc 073989

N A56 Table 4.3. Summary of most sensitive endpoints from submitted aqua tic toxicity studies for lambda -cyhalothrin.

Species

(common name) Taxa Represented Endpoint Duration (hours) Mean concentration

(μg a.i./L) Citation

MRID Acute Toxicity Classification

LOAEC 0.0005 Acceptable

Table 4.4. Summary of most sensitive endpoints from submitted aqua tic animal toxicity studies for gamma -cyhalothrin.

Species

(common name) Taxa Represented Endpoint Duration (hours) Mean concentration

(μg a.i./L) Citation

MRID Acute Toxicity Classification

Lepomis macrochirus (Bluegill sunfish) Freshwater fishand aquaticphase amphibians LC 50 96 0.029 45447215

supplemental Highly toxic

Gammarus pseudolimnaeus

(Amphipod) Freshwater Invertebrates EC 50 96 0.00048 46065601

supplemental Very highly toxic

Plants No terrestrial plant data or a quatic vascular plants studies ar e available to the Agency for lambda or gamma -cyhalothrin. One study conducted using aquatic non-vascular plant (freshwater green algae) reported the EC 50 as >310 ppb. Two studies conducted us ing aquatic non-vascular plants were conducted with gamma -cyhalothrin, and these studies also s how low toxicity to algal species (EC 50 >2850 μ g a.i. /L and EC 50 = 15000 μ g a.i. /L, MRIDs 45447406 and 45447407). In these studies, the algae were exposed to levels much higher than the solubility of either chemical.

Table 4.5. Acute Toxic Effects of Lambda -cyhalothrin and Gamma -cyhalothrin to Aquatic Plants

Species Study Guideline % A.I. Toxicity Endpoint

μ g a.i. /L Study Classification MRID #

Freshwater Non-vascular Plants

Green Algae Selenastrum capricornutum ( Lambda

cyhalothrin ) 123-2 96.5 EC 50 96 hr :>310
NOAEC : ≥ 310 Supplemental 152731

Green Algae 123-2 EC 50 96 hr :>285057 Table 4.5. Acute Toxic Effects of Lambda -cyhalothrin and Gamma -cyhalothrin to Aquatic Plants

Selenastrum capricornutum ( Gamma

cyhalothrin) 100 NOAEC : <1340 Supplemental 45447406

Green Algae Selenastrum capricornutum ( Gamma

cyhalothrin) 123-2 14.7 Cell density EC 50 72 hr: 15000 NOAEC: 5480 Growth rate EC 50 72 hr:41300 NOAEC: 5480 Area under curve EC 50 72 hr:16100 NOAEC: N.R. Supplemental 45447407

ECOTOX Available open literature will be used to evaluate the potential direct effects of lambda

cyhalothrin and gamma -cyhalothrin to the terrestrial receptors identified in this section. This includes toxicity data on the te chnical grade active ingredient, and when available, formulated products ( e.g. “Six-Pack” studies).

At this time, a full and complete ECOTOX search has not been performed, but will be conducted prior to issuance of any Data Call-in. The open l iterature studies will be identified through EPA’s ECOTOX database ( http://cfpub.epa.gov/ecotox/ ), which employs a literature search engine for locating chemical toxicity data fo r aquatic life, terrestrial plants, and wildlife. The evaluation of data can also provide insight into the direct and indi rect effects of lambda -cyhalothrin and

gamma -cyhalothrin on biotic communities from loss of species that are sensitive to the chemical and from changes in structure and functional char acteristics of the affected communities. Open literature toxicity data for other ‘target’ insect species (not incl uding bees, butterflies, beetles, and non-insect invertebrates including soil arthropods and worms), which include efficacy studies, are not currently considered in deriving the most sens itive endpoint for terrestrial insects. Efficacy studies do not typically provide endpoint valu es that are useful for risk assessment ( e.g. , NOAEC, EC 50 , etc.), but rather are intended to identify a dose that maximizes a particular effect ( e.g. , EC 100 ). Therefore, efficacy data and non-efficacy t oxicological target insect data will not be included in the ECOTOX open literature search.

4.2. Incident Database Review

A preliminary review on August 12, 2010 of the Ec ological Incident Information System (EIIS, version 2.1), which is maintained by the Agency’s Office of Pesticide Programs indicates reported ecological incidents associ ated with the use of lambda -cyhalothrin and gamma -cyhalothrin. A search for incidents involving lambda -cyhalothrin or gamma -cyhalothrin was also conducted in the American Bird Conservancy’s Avian Incident Monitoring System (AIMS). These incidents are summarized in Table 4.5 . This total excludes incidents cl assified as ‘unlikely’ and only58 includes those incidents with certainty categor ies of ‘highly probable’ , and ‘probable’ and ‘possible’ (for EIIS) and ‘certain’, ‘highly likely’, ‘likely’, ‘probable’, and ‘possible’ (for AIMS). In the EIIS and AIMS databases, the “unlikely” ca tegory is used when a chemical is not likely to be responsible for the incident. For example, an ‘unlikely’ classificati on might be applied in situations where a given chemical is practically nontoxic to the category of organism killed and/ or there is evidence that anothe r pesticide or stressor likely caused the incident. Incidents classified as ‘unlikely’ for lambda -cyhalothrin and gamma -cyhalothrin will not be included in this Problem Formulation or the ecological risk asse ssment conducted for Regi stration Review (one “unlikely” incident was reported in EIIS for lambda -cyhalothrin).

There were 12 total incidents reported to the Agency for lambda -cyhalothrin. Of these incidents, 1 was reported as highly probabl e, 4 were reported as probable and 7 reported as possible for association with lambda -cyhalothrin use. Nine of the reported incident involved aquatic species of fish and invertebrates, and three of the incident s involved terrestrial plan t species. These incidents indicate that aquatic organisms and possibly plan ts may be adversely affected if exposed to lambda -cyhalothrin, even if used as registered. See Table 4.5 for summary.

No incidents were reported in EIIS for gamma -cyhalothrin. The AIMS data base contains no avian incidents involving lambda -cyhalothrin or gamma -cyhalothrin.

Table 4.5. Wildlife Incidents Associated with lambda -cyhalothrin

Incident
Number Taxa
Involved Magnitude Year Location (County,

State) Use Legality of Use Certainty Category 1

I007462- 001 Fish 16 1998 Jackson, MO Broadcast

near building M Probable

I007176- 001 Crayfish 90 to 100

acre area 1998 LA Spray, corn RU Probable

I000922- 001 Fish Not reported 1991 Laurens, GA Broadcast,

cotton RU Possible

I000921- 001 Bass
Bream Catfish Hundreds 1991 Lowndes, GA Broadcast,

cotton RU Probable

I003826- 029 Bass 200 1994 Cumberland, NC Cotton (no details) RU Possible

I015186- 003 Crayfish Not reported 2004 Wilson, TX Spray, Cotton RU Highly Probable

I005805- 003 Not reported Not reported 1997 Scott, IN Unknown UN Possible59 Incident
Number Taxa
Involved Magnitude Year Location (County,

State) Use Legality of Use Certainty Category 1

I009314- 007 Not reported Not reported 1997 Scott, IN Unknown UN Possible

I007650- 001 Crayfish Not reported 1998 Acadia, LA In field, no

crop specified M Probably

I016036- 006 Basil Not reported 2004 Stanislaus, CA Air blast RU Possible

I014597- 027 Cotton 78 acres 2003 Hardin, IA Suspension RU Possible

I014597- 047 Tobacco 200 acres 2003 Breckinridge , KY Spray M Possible

1 Incidents classified as ‘unlikel y’ are excluded; RU = Register ed Use; M = Misuse; UN = Unknown

Incident reports for non-target organisms typical ly provide information only on mortality events and plant damage incidents. Except for phytotoxic e ffects in terrestrial plan ts, sublethal effects for organisms such as reduced growth or impaired reproduction are rarely repo rted. EPA’s changes in the registrant reporting requirements for incide nts in 1998 may account for a reduced number of reported incidents. Registrants are now only re quired to submit detailed information on ‘major’ fish, wildlife, and plant incidents. Minor fish, wildlife, and plant incidents, as well as all other nontarget incidents, are ge nerally reported aggregately and are not included in EIIS. In addition, there have been changes in state monitori ng efforts due to lack of resources.

In the forthcoming ecological risk assessment, these incidents will be further evaluated to determine if they represent current patterns of use for lambda -cyhalothrin and/ or gamma

cyhalothrin. Examples of additional considerations are mitigation ( e.g ., reduced application rates), product cancellations, and changes in use pa tterns that have occurred since the date of the reported incidents.

Lambda -cyhalothrin is among the constituents monitored by the National Water Quality Assessment Data Warehouse, (NAWQA) maintained by the U.S. Geological Survey; furthermore, multiple articles from the literature document the presence of synthetic pyrethroids like lambda

cyhalothrin and/ or gamma -cyhalothrin in both urban and agricultural water and sediments (refer

to Appendix B ).

4.3. Ecosystems Potentially at Risk

Lambda -cyhalothrin and gamma -cyhalothrin may be applied on a variety of food/feed crops, including (but not limited to), wheat, cotton, peanut , sugarcane, alfalfa, corn, cole crops, fruiting vegetables, legume vegetables, lettuce, onion, soybea n, pome fruits, stone fruits and tree nuts. In addition, they may be used on numerous non-food sites ( e.g. conifers, forest trees, ornamentals,60 golf courses, and ornamental lawns and turf). Finally, these chemicals may be used on an aquatic environment ( i.e. use on rice). Thus, the ecosystems at ri sk may be extensive in scope, and as a result it may not be possible to identify specifi c ecosystems during the development of a baseline risk assessment. In general terms, terrestrial ecosystems potentially at risk due to the use of lambda -cyhalothrin and gamma -cyhalothrin, could include the tr eated field and areas immediately adjacent to the treated field that may receive drift or runoff. Areas adjacent to the treated field could include cultivated fields, fencerows and hedgerows, meadows, fallow fields or grasslands, woodlands, riparian habitats and other uncultivated areas. Due to the potential persistence of lambda -cyhalothrin and gamma -cyhalothrin, they are expected to drift and/or runoff due to application to food crops, resu lting in possible exposure to aquatic ecosystems. Aquatic ecosystems potentially at risk due to the use of lambda -cyhalothrin and gamma -cyhalothrin include water bodies adjacent to, or down str eam from, the treated field and might include impounded bodies such as ponds, lakes and reservoirs , or flowing waterways such as streams or rivers. For uses in coastal areas, aquatic hab itat also includes marine ecosystems, such as estuaries.

5. Assessment Endpoints

Assessment endpoints are defined as “explicit expressions of the actual envir onmental value that is to be protected.” Defining an assessment endpoint involves two steps: 1) identifying the valued attributes of the environment that are considered to be at risk; and 2) operationally defining the assessment endpoint in terms of an ecological entity ( i.e. , a community of fish and aquatic invertebrates) and its attributes ( i.e. , survival and reproduction). Therefore, selection of the assessment endpoints is based on valued entities ( i.e. , ecological receptors), the ecosystems potentially at risk, the migration pathways of pesticides, and the routes by which ecological receptors are exposed to pesticide-related cont amination. The selection of clearly defined assessment endpoints is important because they provide direction and bou ndaries in the risk assessment for addressing risk management issues of concern. Changes to assessment endpoints are typically estimated from the available toxici ty studies, which are used as the measures of effects to characterize potential ecological risks associated with exposure to pesticides, such as lambda -cyhalothrin and gamma -cyhalothrin.

To estimate exposure concentrations, the ecological risk assessment considers applications at the maximum application rate to fields that have vu lnerable soils. 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. Toxicity tests are intended to determine effects of pesticide e xposure on birds, mammals, fish, terrestrial and aquatic invertebrates, and pl ants. These tests include short-term acute, sub-acute, and reproduction studies and are typically arranged in a hier archical or tiered system that progresses from basic laboratory tests to appl ied field studies. The toxicity studies are used to evaluate the potential of a pesticide to cause adverse effects, to determine wh ether further testing is required, and to determine the need for precautionary labe l statements to minimize the potential adverse effects to non-target animals and plants.61 An open literature search will be conducted to determine any relevant endpoints. The search will focus on survival, growth and reproductive eff ects for aquatic and terrestrial effects of lambda

cyhalothrin and/ or gamma -cyhalothrin. More sensitive endpoints from acceptable open literature studies will be included in this risk assessment.

6. Conceptual Model

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

A conceptual model provides a written descriptio n and visual representation of the predicted relationships between lambda -cyhalothrin or gamma -cyhalothrin, potential routes of exposure, and the predicted effects for the assessment endpoi nt. A conceptual model consists of two major components: risk hypothesis and a conceptual diagram (USEPA, 1998).

6.1. Risk Hypothesis

Risk hypotheses are specific assumptions about potential adverse effects ( i.e. , changes in assessment endpoints) and may be based on theory and logic, empirical data, mathematical models, or probability models (USEPA 1998). For th is assessment, the risk is stressor-initiated, where the stressor is the release of lambda -cyhalothrin or gamma -cyhalothrin into the environment. The following risk hypotheses are presumed for this screening-level assessment:

Lambda-cyhalothrin and gamma- cyhalothrin, when used in accordance with registered labels, will likely lead to off- site movement of the compound vi a runoff, spray drift, and eroded soil leading to exposure of nontarget plants and animals Based on information on the environmental fate, mode of action, direct toxicity and potential in direct effects, EFED assumes that registered uses of lambda- cyhalothrin and gamma-cyhalothrin have the potential to cause reduced survival, growt h, and reproduction to non-target terrestrial and/ or aquatic animals and plants.

Lambda-cyhalothrin and gamma- cyhalothrin, when used indoors, in accordance with current labels, may result in off-site movem ent of the compound via wash-off into surface waters via drains and treatment plants, lead ing to exposure of nontarget aquatic plants and animals. This potential ex posure pathway may result in adverse effects upon the survival, growth, and/or re production of non-target aquat ic animals and plants.

Lambda-cyhalothrin and gamma-cyhalothrin, when used in ear tag and cattle pour on products, in accordance with current labels , may result in off-s ite movement of the compound via wash-off of cattle and calves or accidental fall of an ear tag into surface waters, leading to exposure of nontarget aquat ic plants and animals. This potential62 exposure pathway may result in adverse ef fects upon the survival, growth, and/or reproduction of non-target aquatic animals and plants.

The conceptual model is a generic graphic depi ction of the risk hypothesis. It includes the potential pesticide or stressor ( lambda -cyhalothrin, gamma -cyhalothrin and possible metabolites, as well as synergists), the source of the pesticide and/or transport pathways, exposure media, exposure point, biological receptor types, and attribute changes.

6.2. Conceptual Diagram

The conceptual site model is a generic graphic de piction of the risk hypothesis, and assumes that the insecticides lambda -cyhalothrin and gamma -cyhalothrin, which are Type II synthetic pyrethroids, having multiple outdoor agricultura l and non-agricultural uses, are capable of affecting aquatic and terrestrial animals prov ided that environmental concentrations are sufficiently elevated as a result of proposed label uses. Based on an examination of the physicochemical properties of lambda -cyhalothrin and gamma -cyhalothrin, the fate and disposition in the environment, and mode of application, a concep tual model was developed that represents the possible relati onships between the stressors, ecological recept ors, and the assessment endpoints. Through a preliminary iterat ive process of examining available data, the conceptual model ( i.e ., the representation of the risk hypothe sis) may be refined to reflect the likely exposure pathways and the organisms that are most relevant and applicable to this assessment ( Figures 6.1a and 6.1b ). They include the potenti al pesticide or stressor ( lambda

cyhalothrin and/or gamma -cyhalothrin, but the presence of toxicologically important metabolites cannot be ruled out), the sources and/ or transport pathways, expos ure media and exposure points, biological receptor types and attribute changes.

In order for a chemical to pose an ecologica l risk, it must reach ecological receptors in biologically significant c oncentrations. An exposure pathway is the means by which a pesticide moves in the environment from a source to an ecological receptor. For an ecological exposure pathway to be complete, it must have a source, a release mechanism, an environmental transport medium, a point of exposure for ecological recep tors, and a feasible route of exposure. In addition, the potential mechanisms of degradation/ transformation ( i.e. , which degradation/ transformation products may form in the environm ent, in which media, and how much) must be understood, especially if for the chemical, its metabolit es/ transformation products are of greater toxicological concern than the parent com pound. The assessment of ecological exposure pathways, therefore, includes an examination of the source and pot ential migration pathways for constituents, and the determination of potential exposure routes.

Under the possible uses of lambda -cyhalothrin and gamma -cyhalothrin, the sources and mechanisms of release of the compounds are fr om ground or aerial spray or ULV applications. Note that this conceptual model considers agri cultural applications as well as certain nonagricultural applications. Surface runoff from th e areas of application is assumed to depend on factors such as topography, irrigation, and rain fall events. Direct deposition may result in contamination of food items that may be consumed by terrestrial organisms. Spray drift results in63 contaminated adjacent areas, including bodies of water. Leaching to groundwater is not considered an important source because lambda -cyhalothrin and gamma -cyhalothrin show low mobility in a variety of soils. Lambda -cyhalothrin and gamma -cyhalothrin appear to have a low potential for volatilization, with a low vapor pressure and Henry’s Law Constants. Further, the hydroxyl radical reac tion half-life for lambda -cyhalothrin is 0.34 days (and the ozone reaction half-life is 7.05 days, both are EP I Suite v.4.0 estimates). The short (atmospheric) half-life, the low vapor pressure (~10 -10 to ~10 -9 mmHg) and Henry’s Law constants (~10 -7 atm/m 3 -mol), and their binding capacity, suggest that the potential for atmospheric transport for lambda -cyhalothrin and gamma -cyhalothrin is relatively low and that this source of the chemical is of low importance, compared to spray drift, runoff and/ or direct cont act after application.

For aquatic receptors, the major point of expos ure is through direct contact with the water column, sediment, and pore water (gill/ integumen t) contaminated with spray drift (from spray application) and/or runoff from tr eated areas. Indirect effects to aquatic organisms (both fish and aquatic invertebrates) can also occur through impact to various f ood chains. It was established earlier in this document that lambda -cyhalothrin and gamma -cyhalothrin have the potential to bioaccumulate/ bioconcentrate. The representative aquatic receptors are certain freshwater and estuarine/ marine fish, inverteb rates, and, in certain cases, aqua tic plants. The major point of exposure for terrestrial animals is consumption of food contaminated with re sidues such as grass, foliage, and small insects. For plants, the point of exposure is direct contact or root uptake. The representative terrestrial receptors are mammals , birds and terrestrial plants. The attribute changes used to assess risk to terrestri al receptors depend on the type of test ( e.g. , reduced survival, growth, or reproduction for animals a nd seedling emergence and vegetative vigor for plants). It should be noted, that these species do not cover all th e possible species in the animal and plant kingdoms; certain taxa ar e considered as surrogates for other taxa. For example, fish are considered surrogates fo r aquatic phase amphibians.

This conceptual model also shows details about biomagnification for a chemical (see piscivorous birds and mammals in Fig. 6.1b ). Lambda -cyhalothrin and gamma -cyhalothrin have a very high
K OW and according to its physicochemical and fa te properties, there is a potential for bioaccumulation/ bioconcentration in aquatic or ganisms, and biomagnification in terrestrial organisms.

Lambda -cyhalothrin and gamma -cyhalothrin show a very lo w solubility, a very high K OW and also high K OC s. These properties suggest that the ch emicals partition with the sediments, and with organic matter, suspe nded in the water bodies. Lambda -cyhalothrin and gamma -cyhalothrin are likely to concentrate in th e sediments, especially after re peated exposures (applications), where they could persist. Such sediments could se rve as repositories of the chemical for extended periods of time and could potentially be toxic to sediment dwelling organisms, affecting the food chain. These issues will also be assessed in the risk assessment for lambda -cyhalothrin and

gamma -cyhalothrin.64 Figure 6.1a. Aquatic conceptual model de picting stressors, exposure pathways, and potential effects to aquatic organisms from the use of lambda -cyhalothrin and gamma
cyhalothrin on agricultural and certain non-agricultural sites

**Route of exposure includes only ingestion of fish and aquatic inverts. 

### Stressor

Source

Receptors

Attribute Change Bifenthrin applied to agricultural or non-agricultural use site

Spra y drift

Aquatic animals Invertebrates Vertebrates **Piscivorous mammals and birds

Individual organisms Reduced survival Reduced growth Reduced reproduction Food chain Reduction in algae and vascular plants Reduction in prey Modification of PCEs related to prey availability Habitat integrity Reduction in primary productivity Reduced cover Community change Modification of PCEs related to habitat Surface water/ S ediment Runoff

Aquatic Animals Invertebrates Vertebrates 

### Exposure Media

Uptake/gills or integument

In g estion Ingestion Atmospheric transport

Wet/dry deposition Soil Leaching to Groundwater

Uptake/gills or integument

Aquatic Plants Non-vascular Vascular Uptake/cell, roots, leaves Riparian plants terrestrial
exposure pathways; see

Figure 6.1b Impervious Surfaces

Flow 1

1 Includes flow across vegetation and vegetated drainage systems ( e.g. , swales) and flow across impervious surfaces and through impervious (piped) storm drains.

Dotted lines indicate exposure pathways that have a low likelihood of contributing to ecological risk.65 Figure 6.1b. Terrestrial conceptual model de picting stressors, exposure pathways, and potential effects to terrestria l organisms from the use of lambda -cyhalothrin and gamma
cyhalothrin on agricultural and certain non-agricultural sites

Stressor

Source

Attribute Change Lambda -cyhalothrin and/ or gamma -cyhalothrin applied to agricultural or non-agricultural use sites

Direct application Spray drift

Terrestrial vertebrates Terrestrial invertebrates

Individual organisms Reduced survival Reduced growth Reduced reproduction Food chain Reduction in prey and food Modification of PCEs related to prey availability Habitat integrity Reduction in primary productivity Reduced cover Community change Modification of PCEs related Terrestrial plants grasses/ forbs, fruit, seeds (trees, shrubs) Runoff

Terrestrial vertebrates Exposure Media & Receptors Soil

Ingestion Ingestion Ingestion Dermal uptake/Ingestion Atmospheric transport

Root uptake/contact
Wet/dry deposition

Ingestion Leaching to Groundwater Irrigation

water

to habitat

Dotted lines indicate exposure pathways that have a low likelihood of contributing to ecological risk.

The conceptual model for potential risks of lambda -cyhalothrin and/or gamma -cyhalothrin to aquatic organisms due to various indoor uses of the chemical that could potentially end up in a “drain” is depicted in Fig. 6.2 . The stressor is the chemical of concern, lambda -cyhalothrin and

gamma -cyhalothrin. It is noted that the transport pa thway is wastewater flow, the exposure media is the treatment facility and the exposure point or route, recepto r, and attribute changes for aquatic organisms are similar to the conceptual model for agricultural applications.66 Figure 6.2. Conceptual mode l for potential risks of lambda -cyhalothrin and gamma
cyhalothrin to aquatic organisms for various indoor uses of the chemical that could potentially end up in the “drain.”

Stressor

Source/ Transport Pathways Wastewater flow

Source/ Exposure Media Treatment facility discharges into surface
waters

Exposure
Route Gill/ Integument Uptake

Receptors

Attribute Changes Aquatic Invertebrates, Vertebrates

Individual Vertebrates and

Invertebrates Reduced survival or reproduction Plant Population Reduced population

growth A quatic Plants Uptake/ Adsorption Lambda -cyhalothrin and gamma -cyhalothrin applications that could p otentiall y end u p “down-the-drain”

The conceptual model for potential risks of lambda -cyhalothrin and/ or gamma -cyhalothrin to terrestrial and aquatic organisms as a result of th e ear tags or pour on treatment on cattle or calves is depicted in Fig. 6.3 . The stressor is the chemical of concern, lambda -cyhalothrin and gamma

cyhalothrin, and potentially inter actions caused by applications with the synergist PBO. The organisms that could be expected to be affected are terrestrial pl ants, aquatic plants and aquatic animals. It is noted that the potential transport pathway, th e exposure media and the exposure point or route, receptor, and at tribute changes for plant and aquatic organisms are similar to the conceptual model for agricultural applications Fig. 6.1a

. Figure 6.3: Conceptual mode l for potential risks of lambda -cyhalothrin or gamma
cyhalothrin to aquatic organisms a result of the ear tags or pour on treatment on cattle or
calves.67 Stressor Lambda -cyhalothrin or Gamma -cyhalothrin Used as Ear Tags or Pour-On Treatment (Immersion in Surface Water Body or Washoff Transported N earby or to Surface Waters)

Source/ Transport Pathways Surface waters

Source/ Exposure Media Riparian/ Wetland Foliage/Soil Receiving Water Body/ Sediment

Exposure
Route Direct Contact/ Root Uptake Gill/ Integument

Uptake

Receptors

Attribute Changes Aquatic Invertebrates,

Vertebrates Wetland/ Riparian

Plants

Individual Plants Reduced survival, growth, or reproduction Individual Vertebrates and Invertebrates Reduced survival or reproduction Plant Population Uptake/ Adsorption

Aquatic Plants

Reduced population

growth

7. Analysis Plan

In order to address the risk hypot hesis, the potential for adverse effects on the environment is estimated. Usage, environmental fate a nd transport, and ec ological effects of lambda -cyhalothrin and gamma -cyhalothrin are characterized a nd integrated to assess the risks. This is accomplished using a risk quotient (ratio of exposure concen tration to effects con centration) approach. Although risk is often defined as the likelihood a nd magnitude of adverse ecological effects, the risk quotient-based approach does not provide a quantitative estimate of likelihood and/ or magnitude of an adverse effect. However, as outlined in the Overview Document (USEPA 2004), the likelihood of effects to indivi dual organisms from particular us es of a chemical is estimated using the probit dose-response slope and either the level of con cern (discussed below) or the actual calculated risk quotient value.

This analysis plan will be re visited and may be revised dependi ng on the data available in the open literature and the information submitted by th e public or the registrant in response to the opening of the Registration Review docket.68 7.1. Stressors of Concern

The focus of this assessment is on the parent materials, lambda -cyhalothrin and gamma

cyhalothrin. However, the Agency will review open literature to identify degradate(s) of potential toxicological concern ( e.g. , Compound XV, Compounds Ia and Ib, and Compound V). Also, risk resulting from use of lambda -cyhalothrin and gamma -cyhalothrin with the synergist PBO will be assessed for cattle pour-on treatments.

Toxicity data for environmental mixtures of lambda -cyhalothrin and gamma -cyhalothrin with other pesticides (those mixtures occurring in the environment following application), if available, may be presented as part of th e ecological risk assessment. Lambda -cyhalothrin and gamma

cyhalothrin may be applied in ta nk mixtures with other products approved for use on registered crops. It is expected th at the toxic effect of lambda -cyhalothrin and gamma -cyhalothrin, in combination with other pesticides used in the en vironment, is likely to be a function of many factors including, but not necessa rily limited to (1) the exposed species, (2) the co-contaminants in the mixture, (3) the ratio of lambda -cyhalothrin and/or gamma -cyhalothrin and co-contaminant concentrations, (4) differences in the pattern and duration of exposure among contaminants, and (5) the differential effects of ot her physical/ chemical characteristics of the receiving waters ( e.g. organic matter present in sediment and suspende d water). A discussion of implications of the available pesticide mixture effects data on the confidence of risk assessment conclusions will be addressed in the risk description of the final ecological assessment.

7.2. Measures of Exposure

In order to estimate risks of lambda -cyhalothrin and gamma -cyhalothrin exposures in aquatic and terrestrial environments, all exposure modeling an d resulting risk conclusions will be made based on maximum application rates for the current use patterns. Available monitoring data will also be considered when describing pot ential environmental exposur e to non-target organisms.

Measures of exposure are based on aquatic and terrestrial models that predict estimated environmental concentrations of lambda -cyhalothrin and gamma -cyhalothrin using maximum labeled application rates and methods, as well as any mitigation measures specifically indicated on the label. The models used to predict aq uatic EECs are the Pestic ide Root Zone Model coupled with the Exposure Analysis Model Syst em (PRZM/EXAMS). Also, to estimate aquatic exposure related to releases of lambda -cyhalothrin and gamma -cyhalothrin from domestic wastewater treatment plants, the Exposure a nd Fate Assessment Screening Tool’s (E-FAST2) down-the-drain module will be used. The Tier 1 Rice Model v.1.0 is used to derive aquatic exposure estimates related to the us es of these chemicals on rice plot s. For the cattle ear tag and pour on uses, measures of exposure will be calcul ations assuming direct applications to water considering living habits of cattle livestock. The model used to predict terrestrial exposure is TREX. The model used to derive EECs relevant to terrestrial and wetland plants is TerrPlant. The potential for bioaccumulation for the chemical is assessed using the KABAM model, as well the results from bioconcentra tion in fish studies ( e.g. the bioconcentration fact ors). These models are parameterized using relevant reviewed registrant-submitted environmental fate and transport data.69 PRZM (v.3.12.2, May 2005) and EXAMS (v.2.98.4.6, Ap ril 2005) are screening simulation models coupled with the input shell PE5.pl (August, 2007) to gene rate daily exposures and 1-in10 year EECs of lambda -cyhalothrin and gamma -cyhalothrin, that may occur from spray drift and runoff to surface water bodies adjacent to app lication sites. PRZM simulates pesticide application, movement and transformation on an agricultural field and th e resultant pesticide loadings to a receiving water body via runoff, erosion and spray drift. The EXAMS model simulates the fate of the pestic ide and resulting concentrations in the water body. The standard scenario used for ecological pesticide asse ssments assumes application to a 10-hectare agricultural field that drains into an adjacent 1-hectare water body that is 2 meters deep (20,000 cubic meters volume) with no outlet. PRZM/ EXAMS is used to estimate screening-level exposure of aquatic organisms to lambda -cyhalothrin and/ or gamma -cyhalothrin and/ or their transformation products, should they be of concer n. The measure of exposure for aquatic species is the 1-in-10 year return peak or rolling mean concentration. Th e 1-in-10 year peak is used for estimating acute exposures of direct effects to aq uatic organisms. The 1-in-10-year 60-day mean is used for assessing chronic exposure to fish an d aquatic-phase amphibians. The 1-in-10-year 21- day mean is used for assessing aqua tic invertebrate chronic exposure.

At the present time, EFED considers the use of the impervious scenar io (a PRZM modeling scenario) as the most suitable available modeling approach for impervious runoff. The PRZM impervious scenario may be used in the tier 2 coupled aquatic models PRZM/EXAMS along with a residential or other suitable scenario such as rights-of-way (ROW) to obtain EECs. The conceptual model for the resident ial scenario integrates simulta neous modeling of the individual use scenario with an impervious scenario. This approach assumes that no watershed is completely covered by either the 1⁄4 acre lot (the basis for the residential scenario) or undeveloped land (the basis for the ROW scenario) for residen tial and ROW use patterns; therefore, differential amounts of runoff will occur within the watershed. The impervious scenario was developed to represent the paved areas within a watershed not including roads, parking lots, sidewalks, and buildings outside the 1⁄4 acre lot (the 1⁄4 acre lot sc enario accounts for impervious surfaces such as buildings within the represented ar ea). By modeling a separate s cenario for impervious surfaces, it is also possible to estimate that amount of exposure that c ould occur when the pesticide is oversprayed onto this surface. Using two scenar ios in tandem requires post-processing of the modeled output in order to derive a weighted EEC that represen ts the contribution of both the pervious ( i.e. , residential and ROW scenarios) and the impervious surfaces. A Microsoft Excel spreadsheet has been developed that allows for the weighting and aggregation of exposure from both scenarios. The daily time series from each m odel run should be copied from the times series file (NAME_TS.out) generated from the PRZM graphical user interf ace (PE5.pl) into the spreadsheet provided. The time series data are th en weighted based on percentage of impervious surface, the percentage of the pervious surface tr eated, and an adjusted tim e series is created. Rolling averages for the releva nt durations of exposure ( e.g. , 21 day and 60 day averages) are calculated, and the relevant one-i n-ten year return EEC is gene rated from these distributions.

Given the aquatic toxicity of lambda -cyhalothrin and gamma -cyhalothrin and their likelihood to occur in sediment, the Agency will also consider the potential exposures re sulting from benthic/70 sediment concentrations (EECs). Pore water concentrations are commonly used to predict toxicity of non-ionic substances in sediments a nd characterize exposure to organisms that spend time in or near sediments (Di Toro et al. 1991; US EPA 2002). PRZM/ EXAMS estimates 1-in10-year peak and 21-day mean EECs for pore water.

To estimate exposure related to releases of lambda -cyhalothrin and gamma -cyhalothrin from domestic wastewater treatment plants, the Agen cy will rely on the Office of Pollution Prevention and Toxics (OPPT) model, Exposure and Fate Assessment Screening Tool (EFAST, version 2.0, or EFAST2, 2007). From this model, the Agency will use the “Down-the-Drain” module, which is designed for releases to dome stic wastewater treatment. It is suitable for all the sources of lambda -cyhalothrin and gamma -cyhalothrin that could potential ly be exposed through a “downthe-drain” scenario. The model provides screening level estimate concentrations of chemicals in surface water that may result from household uses and the disposal of consumer products into wastewater using a few simple input parameters (production volum e and fraction of the chemical removed during wastewater treatment).

Since lambda -cyhalothrin and gamma -cyhalothrin have uses on rice (and wild rice for lambda

cyhalothrin), the screening-level Tier 1 Rice Model v.1.0 will be utilized to obtain estimated exposure concentrations (EECs) related to that use. The Ti er I Rice Model v1.0 relies on an equilibrium partitioning concept to provide conservative estimates of environmental concentrations resulting from a pplication of pesticides to rice paddies. When a pesticide is applied to a rice paddy, the model assumes that it will instantaneously partition between a water phase and a sediment phase. Among the assumpti ons of this model, the degradation of the pesticide and the mass transfer from the aqueous phase to the sediment ar e not considered. Also, volatilization and other dissipation processes are not considered.

There are three possible scenarios whereby lambda -cyhalothrin and gamma -cyhalothrin residues can enter the aquatic ecosystem due to treatment to cattle. First, ear tags can fall off cattle into water bodies (note that ear tags apply only to lambda -cyhalothrin). Second, multiple cattle that are treated with lambda -cyhalothrin and gamma -cyhalothrin can direct ly enter a water body. Third, rainfall can cause washoff of lambda -cyhalothrin and/ or gamma -cyhalothrin residues to be transported from treated multiple cattle to water bodies via runoff. For each of these cases, surface water concentrations will be ca lculated using the maximum mass of lambda -cyhalothrin and gamma -cyhalothrin per animal, 4.18x10 -4 lb a.i./ cattle (0.190 g) for the lambda -cyhalothrin ear tag use, 3.13x10 -4 lb a.i./ cattle (0.142 g) for the lambda -cyhalothrin pour on products, and
1.56x10 -4 lb a.i./ cattle (0.0708 g) of gamma -cyhalothrin for the single pour on product, spilling into a standard farm pond of 1 ha area and 2 m depth or a volume of 2.0 x 10 7 L. Surface water EECs will be calculated utilizing a suitable pr ogram which considers the soil-water partition coefficient and the depth of the sediment laye r such as the KdCalc (v.1.0 10/02/02). Certain assumptions are required for these scenarios. For example, for the se cond scenario, 20 treated cattle may be assumed to enter the water and for the third scenario, a 1000 treated cattle feedlot may be assumed (USDA NASS data). 13 A maximum of 20% is assumed to wash off cow hide for

13 http://www.nass.usda.gov/Surveys/Guide_to _NASS_Surveys/Cattle_On_Feed/index.asp and http://usda.mannlib.cornell.edu/usda/cur rent/CattOnFe/CattOnFe-07-23-2010.pdf (both accessed 08/16/10) “Cattle on71 the ear tags treatment; however, 100% is assumed for pour on products.

Exposure estimates for terrestrial an imals assumed to be in the target area are derived using the TREX model (version 1.3.1, 12/07/2006). This spr eadsheet-based model calculates the residues on avian and mammalian food items along with the dissi pation rate of a chemical applied to foliar surfaces (for single or multiple applications) in order to estimate acute and reproductive risk quotients. T-REX calculates EECs and risk quo tients based on both the upper bound and mean residue concentrations as pres ented by Hoerger and Kenaga ( 1972) and modified by Fletcher et al. (1994). These concentrations are determined usi ng nomograms that relate application rate of a pesticide to residues remaining on dietary items of terrestrial or ganisms. EECs for terrestrial plants inhabiting dry and wetla nd areas are derived using Terr Plant (version 1.2.2, 12/26/2006). This model uses estimates of pesticides in runo ff and in spray drift to calculate EECs. EECs are based upon solubility, app lication rate and minimu m incorporation depth.

As indicated in Table 3.1 and its associated text in Section 3

, lambda -cyhalothrin and gamma

cyhalothrin appear to have a pot ential to bioconcentrate in aquatic organisms and it appears that there is also some potential to biomagnify in terrestrial organisms. The potential for bioaccumulation of lambda -cyhalothrin and gamma -cyhalothrin will also be examined in the risk
assessment. Because lambda -cyhalothrin and gamma -cyhalothrin have a fairly high K OW (10 5 to 10 7 ) and the chemical may be persistent in wa ter and sediments, there is a potential for bioaccumulation. The maximum bioconcentration factor was 4,600x for whole fish and depuration rate is moderate (half depu ration time of ~9 days, MRID 00152744, 00152745). Bioaccumulation will be assessed using the results from bioaccumulation in fish studies, as well as the KABAM model (K OW (based) Aquatic BioAccumulation Model, version 1.0, 2009), adjusting for biotransformation rates. KABAM is used to estimate potential bioaccumulation of hydrophobic organic pesticides in freshwater aquatic ecosystems and risks to mammals and birds consuming aquatic organisms whic h have bioaccumulated these pest icides. Monitoring data and biotransformation rates in terrestrial species will also be evaluated, to assess the potential for bioaccumulation in terrestrial food webs.

7.3. Measures of Effect

Ecological effects data are used as measures of dir ect and indirect effects to biological receptors. Data are typically obtained from registrant-submitte d studies or from literature studies identified by ECOTOX. The ECOTOX database provides more ecological effects data in an attempt to bridge existing data gaps. EC OTOX is a source for locating single chemical toxicity data and potential chemical mixture toxicity data for aquatic life, terrestrial plants, and wildlife. ECOTOX was created and is maintained by the USEPA, Office of Research and Development, and the National Health and Environmental Effects Research Laboratory's Mid-Continent Ecology Division.

feed in feedlots with 1,000 or more head accounted for 84 percent of the total cattle on feed on July 1, 2010, down slightly from July 1, 2009.”72 The acute measures of effect used fo r animals in this assessment are the LD 50 , LC 50 and EC 50

. LD stands for "Lethal Dose", and LD 50 is the amount of a material, given all at once, that is estimated to cause the death of 50% of the test organisms. LC st ands for “Lethal Concentration” and LC 50 is the concentration of a chemical that is estimated to kill 50% of the test organisms. EC stands for “Effective Concentration” and the EC 50 is the concentration of a chemical that is estimated to produce a specific effect in 50% of the test organisms. Endpoints for chronic measures of exposure for listed and non-lis ted animals are the NOAEL/NOAEC and NOEC. NOAEL stands for “No Observed-Adverse-Effect-Level ” and refers to the hi ghest tested dose of a substance that has been reported to have no harm ful (adverse) effects on test organisms. The NOAEC ( i.e. , “No-Observed-Adverse-Effect-Concentration” ) is the highest test concentration at which none of the observed effects were statistically different from the control. The NOEC is the No-Observed-Effects-Concentration. For non-li sted plants, only acute exposures are assessed ( i.e. , EC 25 for terrestrial plants and EC 50 for aquatic plants); for liste d plants either the NOAEC or EC 05 is used.

Information on the potential effects of lambda -cyhalothrin and gamma -cyhalothrin on non-target animals is also collected from the Ecological Inci dent Information System (EIIS). The EIIS is a database containing adverse effect (typically mortality) reports on non-target organisms where such effects have been associated with the use of pesticides. Informa tion on incidents involving avian species is also provided through the Av ian Monitoring Information System (AIMS), which is maintained by the American Bird Conservancy.

Where available, sub-lethal effects observed in both registrant-submitted and open literature studies will be evaluated qualitatively. Such effects may include behavioral changes ( e.g. , lethargy and changes in colora tion). Quantitative assessments of risks, though, are limited to those endpoints that can be di rectly linked to the Agency’s assessment endpoints of impaired survival, growth and reproduction.

The assessment of risk for direct effects to non- target organisms makes the assumption that the toxicity of lambda -cyhalothrin and gamma -cyhalothrin to birds is similar to terrestrial-phase amphibians and reptiles. The same assumption is made for fish and aquatic-phase amphibians.

Past Agency ecological risk assessments of lambda - and gamma -cyhalothrin have bridged aquatic toxicity data for the two active i ngredients using assumptions of re lative compositions of the most biologically active isomers (US EPA, 2004a; D289801, 289799, 289797, 289794, 289798, 288057). Based on the review of the available da ta, some aquatic organisms show greater sensitivity to gamma -cyhalothrin than lambda -cyhalothrin.

7.4. Integration of Exposure and Effects

Risk characterization is the integration of e xposure and ecological effects to determine the potential ecological risk from the use of pesticides and the likelihood of direct and indirect effects to non-target organisms in aquatic and terrestrial habitats. The exposure a nd toxicity effects data are integrated in order to evalua te the risks of adverse ecological effects on non-target species.73 For the assessment of risks, the risk quotient (RQ) method is used to compare exposure and measured toxicity values. EECs are divided by ac ute and chronic toxicity values. The resulting RQs are then compared to the Agency’s Levels of Concern (LOCs) (USEPA 2004). These criteria will be used to indicate when lambda -cyhalothrin and/ or gamma -cyhalothrin’s uses, as directed on the label, have the potential to cause adverse direct or indirect effects to non-target organisms. In addition, incident data from the EIIS will be considered as part of the risk characterization.

7.5. Deterministic and Probabilistic Assessment Methods

The quantitative assessment of risk will primarily depend on the deterministic point-estimate based approach described in the risk assessment. An effort may also be made to further qualitatively describe risk using probabilistic to ols that the Agency has developed. These tools have been reviewed by FIFRA Scientific Advisory Panels ( http://www.epa.gov/sc ipoly/sap/index.htm ) and have been deemed as appropriate means of refining assessments where deterministic approaches have identified risks.

7.6. Endangered Species Assessments

Consistent with the Agency’s responsibility under the Endangered Species Act (ESA), the Agency will evaluate risks to Federally-listed th reatened and/or endangere d (listed) species from registered uses of lambda -cyhalothrin and gamma -cyhalothrin. This assessment will be conducted in accordance with the Overview Do cument (USEPA 2004), provisions of the ESA, and the Services’ Endangered Species Consultation Handbook (USFWS/NMFS, 1998).

The assessment of effects associ ated with the registration of lambda -cyhalothrin and gamma

cyhalothrin is based on an action ar ea. The action area is considered to be the area directly or indirectly affected by the federal action, as indicated by the exceedance of Agency Levels of Concern (LOCs) used to evaluate direct or indir ect effects. The Agency’s approach to defining the action area under the provision s of the Overview Document (USEPA 2004) considers the results of the risk assessment process to es tablish boundaries for that action area with the understanding that exposures below the Agency’s de fined LOCs constitute a no- effect threshold. For the purposes of this assessment, attention w ill be focused on the footprint of the action ( i.e.

, the area where lambda -cyhalothrin and gamma -cyhalothrin application o ccurs), plus all areas where offsite transport may result in potential exposure that exceeds the Agency’s LOCs. Specific measures of ecological effect that defi ne the action area for listed species include any direct and indirect effects and/ or potential modification of its cr itical habitat, including reduction in survival, growth, and reproduction as well as the full suite of sub- lethal effects available in the effects literature. Therefore, the action area extends to a point where environmental exposures are below any measured lethal or sub-lethal effect threshold for any biologica l entity at the whole organism, organ, tissue, and/ or cellular level of organization. In situations where it is not possible to determine the threshold for an observe d effect, the action area is not spatially limited and is assumed to be the entire United States.74 Currently, EFED does not assess risk to non-target insects. Results of a cceptable studies are used for recommending appropriate label precautions. Lambda -cyhalothrin and gamma -cyhalothrin are both classified as highly t oxic on an acute contact basis. Th is study suggests that the acute toxicity to non-target benefi cial endangered insects may also be of concern should exposure

occur.

Toxicity data are not available for terrestrial plants; thus, risks associated with lambda

cyhalothrin and gamma -cyhalothrin exposure to terr estrial plants cannot be assessed. In the past, it had been indicated that a review of lambda -cyhalothrin and gamma -cyhalothrin’s mode of action (neural toxin) suggested that direct toxicity to plants would not be an issue of concern. Nonetheless, data for these chemicals are required in the absence of any information to support conclusions regarding lambda -cyhalothrin and gamma -cyhalothrin phytotoxicity.

7.7. Drinking Water Assessment

A drinking water assessment will be conducted to support future human health risk assessments of lambda -cyhalothrin and gamma -cyhalothrin should it be require d, based on all the available environmental fate information. The drinking wa ter assessment will incorporate model estimates of lambda -cyhalothrin and/ or gamma -cyhalothrin in surface and gr ound waters. Concentrations in surface waters will be estimated using FQPA Index Reservoir Screening Tool (FIRST, v.1.1.1, 12/18/07) (or subsequently using PRZM/ EXAMS, with the Index Re servoir – for description see above – if refinements are required). Ground water estimates of concentrations will be obtained using the Screening Concentr ation In GRound Water (SCI-GRO W) model (v.2.3, July 2003). The drinking water assessment will also include a summary of available surface and ground water monitoring data.

7.8. Endocrine Disruptor Screening Program

As required under FFDCA section 408(p), EPA has developed the Endocrine Disruptor Screening Program (EDSP) to determine whether certain su bstances (including pesticide active and other ingredients) may have an effect in humans or wildlife si milar to an effect produced by a “naturally occurring estrogen, or other such endocrine effects as the Administrator may designate.” The EDSP employs a two-tiered ap proach to making the statutorily required determinations. Tier 1 consists of a battery of 11 screening assays to identify the potential of a chemical substance to interact with the estroge n, androgen, and or thyroid (E, A, or T) hormonal systems. Chemicals that go th rough Tier 1 screening and are found to have the potential to interact with E, A, or T hormonal systems will proceed to the next stag e of the EDSP where EPA will determine which, if any, of th e Tier 2 tests are necessary base d on the available data. Tier 2 testing is designed to identify a ny adverse endocrine related eff ects caused by the substance, and establish a dose-response relationship between the dose and the E, A, or T effect.

Between October 2009 and February 2010, EPA issued test orders/data call-ins for the first group of 67 chemicals, which contains 58 pesticide active ingredients and 9 inert ingredients. This list of chemicals was selected based on the potential for human exposure through pathways such as75 food and water, residential activity, and certain po st-application agri cultural scenarios. This list should not be construed as a list of known or likely endocrine disruptors.

Lambda -cyhalothrin and gamma -cyhalothrin are not among the group of 58 pesticide active ingredients on the initial list to be screened under the EDSP. The Agency will review the EDSP Tier 1 data and any “other scie ntifically relevant information” submitted in response to test orders. Based on this review the Agency will determine the need for additional testing. For further information on the status of the EDSP, the policies and procedur es, the list of 67 chemicals, the test guidelines and the Tier 1 screening battery, please refer to the following website: http://www.epa.gov/endo/

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7.9. Preliminary Identification of Data Gaps

7.9.1. Fate

After evaluation of the available data for lambda -cyhalothrin and gamma -cyhalothrin, the following data gaps for registrati on review have been identified.

835.2120 Hydrolysis – At this time, there is one availa ble study that was deemed acceptable at pH 5 and 7, conducted on gamma- cyhalothrin; however, the part conducted at pH 9 was deemed unacceptable, but upgradable. The other study wa s conducted at a rate that exceeded the solubility limit of lambda -cyhalothrin. In order to clarify the ra te of reaction of the test substance in pH 9 buffered solutions, the re gistrant should submit data to upgrade the pH 9 study, or a new study should be conducted at pH 9.

835.4200 Anaerobic Soil Metabolism – There is one available anaerobic soil metabolism study, conducted on lambda -cyhalothrin, conducted with one soil, but it supplies only very limited information, with only a few data points. Anaerob ic studies with one soil type are generally sufficient for the evaluation of transformation pathways. Rates of transformation should be determined in at least three additional soils (from Fate, Transport and Transformation Test Guidelines – OCSPP Guideline 835.4100 & 835.4200). For metabolism studies, domestic soils are preferred. The study should be performed with lambda -cyhalothrin or gamma -cyhalothrin.

835.4400 Anaerobic Aquatic Metabolism – A study is available in one soil/ sediment system. According to the OCSPP Fate, Transport a nd Transformation Test Guidelines (835.4300 & 835.4400) “At least two sediments and their associated waters are used for both the aerobic and the anaerobic studies respectively... However, ther e may be cases where more than two aquatic sediments should be used, for example, for a chemical that may be present in freshwater and/or marine environments. Sediments should be repr esentative of intended use sites.” Since both lambda -cyhalothrin and gamma -cyhalothrin have the potential fo r use near estuarine/ marine areas, one of the required sedime nt systems should be from estuarine/ marine environment. Two sediment systems are required for lambda -cyhalothrin, one of which should be of marine origin. For the metabolism studies, domestic sediments are preferred.76 Other studies:

Leachability from Treated Wood – A study is required for lambda -cyhalothrin and/ or gamma

cyhalothrin. It should be conducted using TEP and according to the American Wood Preservers Association Standard Method of Determining the Leachability of Wood Preservatives (E11, edition 06). It is strong ly preferred that the regi strant provided a protocol to be evaluated by the Agency prior to performing the study.

Environmental Chemistry Methods (ECMs), and Independent Laboratory Validations (ILVs), for Soil, Water and Sediment . ECMs associated with the Terrestrial Field Dissipation study (Field dissipation §158.1300; OPPT S guidelines 835.6100, 835.6200, and 835.6300), along with successful confirmatory method trials (validation) by an i ndependent laboratory ( i.e. ILVs), are required. If there is ri sk concern for a given taxon, ECMs should be available for the environmental media in which organisms of the taxon reside. These ECMs should have limits of quantitation for the residues of c oncern that are lower than the relevant toxicological levels of concern. Previous reviews on lambda -cyhalothrin and gamma -cyhalothrin indicate that there is high concern for acute and chronic toxicity to aquatic animals. Certain scenarios may have triggered acute and chronic levels of concern for freshwater and/ or estu arine/ marine aquatic invertebrates and/ or for fish a nd/ or organisms living in the be nthos. Therefore, ECMs for water and sediment are required in addition to the EC M for soil. The ECMs s hould include parent and those residues found in the laboratory studies th at exceeded 10% of the applied. Based on the available data at this time, the following appear to be the residues of concern for each media, but this could change, based upon the results of new environmental fate studies: Soil – parent, Compounds XV, Ia, Ib and 3-(4-hydroxyphenoxy) benzaldehyde Water and Sediment – parent, Compounds Ia, Ib and V The registrant is encouraged to submit state-of-the-art environm ental chemistry methods; further, multi-residue methods (MRMs) for soil, water and sediment are preferred, if applicable. The registrant submitted one method (MRID 40515901, published in the Agency’s ECM website), 14 that could quantify lambda -cyhalothrin in water and sediment. EFED located an Environmental Chemistry Method Evaluation (ECME) performed by the Analytical Chemistry Branch (ACB) of the water portion of th is study (BEAD review dated 9/23/ 93, Environmental Chemistry Method Validation Report No. ECM 0004W1). The ACB dete rmined an LOD of 10 ng/L (ppt) while the registrant’s value is 1 ppt. This method cannot be used to determine lambda -cyhalothrin’s transformation products. Furthermore, ther e is one ECM and one ILV that quantifies lambda

cyhalothrin and other pyreth roids in sediments (MRID 47053001 and 47053002). It is uncertain wether this method can distinguish gamma -cyhalothrin from lambda -cyhalothrin. The Agency will verify the suitability of these methods and the appropriateness of their levels of quantification. At this time, no specific methods have been id entified for the analysis of gamma

cyhalothrin. A full description of the method va lidation procedures performed by an independent laboratory should also be submitted. It shoul d include the following information (Corbin et al. 2006): (a) Recovery level(s) of the test compound(s) from the soil, water and sediment (substrates) at various relevant fortification level(s) using the residue analytical methodology; (b) a validated method sensitivity level; (c) results of the study and stat istical test applied, including a

14 Available at url: http://www.epa.gov/oppbead1/methods/ecmindex.htm77 stepwise presentation of the proc edure for calculating percent recove ry from the raw data; (d) all the data/ information necessary to independently verify the results ; (e) summary of the results; and, (f) discussion and conclusions of the results.

POTW Effluent Monitoring – EFED requests any existi ng or ongoing POTW effluent monitoring data for the pyrethroids be submitted to the Agency.

POTW Treatability Study – The Agency has recently requested and provided comments on a protocol developed by the Pyre throid Working Group (PWG) for a bench scale study of waste water treatment, to assess the percentage rem oved in the biosolids by the treatment, the amount that would degrade during treatment, and the am ount that would remain in the waste water. These data would be used to inform removal pe rcentages by waste water treatment, which is an input to the Exposure and Fate A ssessment Screening Tool’s (E-F AST) down-the-drain module. The Office of Pesticide Programs will continue to c onfer with the Office of Water with the goal of refining our down-the-drain assessm ent for registration review. It is the responsibility of the registrant to ensure that lambda -cyhalothrin and gamma -cyhalothrin are included in the study completed by the PWG or conduct a similar st udy on their own (following submission of a protocol for review).

Table 7.1 lists the status of the environm ental fate data requirements for lambda -cyhalothrin and

gamma -cyhalothrin.

Table 7.1. Summary of Environ mental Fate Data Requirements for Lambda -cyhalothrin and Gamma -cyhalothrin

Study Identification Use
Pattern 1 Does EPA Have Data To Satisfy This Requirement? Bibliographic Citation Must Additional Data Be Submitted Under FIFRA

3(c)(2)(B)?

§158.1300 ENVIRONMENTAL FATE

Degradation Studies-Lab :

835.2120 Hydrolysis 1,2 Yes 00151604, 45447409 Yes 2

835.2240 Photodegradation in
Water 1,2 Yes 44861501, 46394702 No

835.2410 Photodegradation on Soil 1,2 Yes 40052405 No

835.2370 Photodegradation in Air 1,2 No Not Available No

Metabolism Studies-Lab :

835.4100 Aerobic Soil 1,2 Yes 00089995, 00151607, 44861504, 45447410, 45447411 No

835.4200 Anaerobic Soil 1,2 Yes 00151607, 44861504 Yes 378 Table 7.1. Summary of Environ mental Fate Data Requirements for Lambda -cyhalothrin and Gamma -cyhalothrin

Study Identification Use
Pattern 1 Does EPA Have Data To Satisfy This Requirement? Bibliographic Citation Must Additional Data Be Submitted Under FIFRA

3(c)(2)(B)?

835.4300 Aerobic Aquatic 1,2 Yes 44367402, 44861506, 45447412 No

835.4400 Anaerobic Aquatic 1,2 No 44367401 Yes 4

Mobility Studies :

835.1230 Leaching – Adsorption/ Desorption 1,2 Yes 00151608, 44861503, 44861509, 45447613 No

835.1410 Volatility (Lab) 1,2 No Not Available No

835.8100 Volatility (Field) 1,2 No Not Available No

Dissipation Studies-Field :

835.6100 Terrestrial Field Dissipation 1,2 Yes 40052407, 45794902 No

835.6200 Aquatic Field Dissipation 1,2 Yes 44367403, 44367404 No

835.6300 Forestry Dissipation 1,2 No Not Applicable N/A

Ground Water Monitoring Studies :

835.7100 Ground Water Monitoring 1,2 No Not Available Reserved

§158.1100 SPRAY DRIFT
201-1 Droplet Size Spectrum 1,2 Yes Not Available No 5

202-1 Drift Field Evaluation 1,2 Yes Not Available No 5

Other Studies :

Environmental Chemistry Methods (ECMs) and Independent Laboratory Validations (ILVs) 1,2 Yes 40515901, 47053001, 47053002 Yes 6

Leachability from Treated Wood 1, 2 No Not Available Yes 7

POTW Effluent Monitoring and POTW Treatability Study Indoor Uses No Not Available Yes 8

1. Use Patterns: 1=Terrestrial/Food; 2=Terrestrial/Feed. 2. The registrant should submit data to upgrade the pH 9 study conducted with gamma- cyhalothrin or a new study conducted at pH 9 is required.79 Table 7.1. Summary of Environ mental Fate Data Requirements for Lambda -cyhalothrin and Gamma -cyhalothrin

Study Identification Use
Pattern 1 Does EPA Have Data To Satisfy This Requirement? Bibliographic Citation Must Additional Data Be Submitted Under FIFRA

3(c)(2)(B)? 3. Data are required for lambda -cyhalothrin on four soils, as per current guidance. 4. Additional data are required in one sediment system of freshwater origin and another of estuarine/ marine origin. 5. Data requirements covered by submission of the Spray Drift Task Force. 6. The data requirement remains unfulfilled for lambda -cyhalothrin, pending evaluation of three available studies. No data have been identified for gamma-cyhalothrin. 7. It is preferred that the registrant provided a protocol to be evaluated by the Agency prior to performing the study. 8. It is anticipated that these studies will be required.

7.9.2 Effects

Based on previously submitted studies, the Environm ental Fate & Effects Division believes that the ecological effects data can be bridged for lambda - and gamma -cyhalothrin (see discussion in Section 4). Therefore, toxicity data may be submitted for either lambda - and gamma -cyhalothrin to address data concerns. For registration revi ew, the following studies are being requested to fulfill any data gaps:

Study Title: Endocrine Disruptor Screening Program As required under FFDCA section 408(p), EPA has developed the Endocrine Disruptor Screening Program (EDSP) to determine whether certain su bstances (including pesticide active and other ingredients) may have an effect in humans or wildlife si milar to an effect produced by a “naturally occurring estrogen, or other such endocrine effects as the Administrator may designate.” The EDSP employs a two-tiered ap proach to making the statutorily required determinations. Tier 1 consists of a battery of 11 screening assays to identify the potential of a chemical substance to interact with the estroge n, androgen, and or thyroid (E, A, or T) hormonal systems. Chemicals that go th rough Tier 1 screening and are found to have the potential to interact with E, A, or T hormonal systems will proceed to the next stag e of the EDSP where EPA will determine which, if any, of th e Tier 2 tests are necessary base d on the available data. Tier 2 testing is designed to identify a ny adverse endocrine related eff ects caused by the substance, and establish a dose-response relationship between the dose and the E, A, or T effect.

Between October 2009 and February 2010, EPA issued test orders/data call-ins for the first group of 67 chemicals, which contains 58 pesticide active ingredients and 9 inert ingredients. This list of chemicals was selected based on the potential for human exposure through pathways such as food and water, residential activity, and certain po st-application agri cultural scenarios. This list should not be construed as a list of known or likely endocrine disruptors.

Lambda - and gamma -cyhalothrin are not among the group of 58 pesticide active ingredients on the initial list to be screened under the EDSP, but data may be required in future screening lists. The Agency will review the EDSP Tier 1 data and a ny “other scientifically relevant information” submitted in response to test orders. Based on this review the Agency will determine the need for80 additional testing. For further information on the status of the EDSP, the policies and procedures, the list of 67 chemicals, the test guidelines and the Tier 1 screening batter y, please refer to the following website: http://www.epa.gov/endo/

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Guideline Number: 850-2100 Study Title: Passerine Acute Avian Oral Although an acute avian oral study was received for both the mallard duck ( lambda -cyhalothrin) and bobwhite quail ( gamma -cyhalothrin), the Agency updated its data requirements in 40 CFR Part 158 (October 26, 2007) to include an acute or al toxicity study for both a passerine species and either a waterfowl or an upla nd game species. Prior to starting toxicity testing, a protocol will need to be provided for review. Many passerine species utilize agricu ltural fields, forests, residential areas and surrounding areas, and, theref ore, have the potential to be exposed to pesticides used in agricultural, fo rest, and residential settings. It is likely that, for most pesticide use patterns, passerines are more likely to be expo sed to pesticides than upland game species and waterfowl. Passerines are smaller in size and generally have faster metabolisms than the waterfowl and upland game bird species traditionally used in avian toxicity tests which could impact their sensitivity to chemical s. A study is requested with either lambda - or gamma

cyhalothrin.

Guideline Numbers: Non-guideline Study Title: Aquatic Invertebrate Acute Toxicity ( Hyalella azteca ) Based on a review of the registrant-submitted studies, amphipods ( Gammarus pseudolimnaeus

, EC 50 =0.00048 μg a.i./L) are more sensitive to gamma -cyhalothrin technical than the Daphnia

magna (EC 50 =0.045 μg a.i./L) by two orders of magnitude. For lambda -cyhalothrin, the same trend is observed (EC 50 =0.0067 μg a.i./L for Gammarus pulex compared to an EC 50 =0.24 μg a.i./L for Daphnia magna based on studies with the technical product). The previously submitted amphipod study is classified as supplemental and be lieved to be an underestimation of the true toxicity of gamma -cyhalothrin technical because of rapidl y declining exposure concentration over the duration of the study. In a ddition, available information in the Agency ECOTOX database and studies in the open literature (Weston and Lydy, 2010; Solomon et al 2001) indicate that the freshwater amphipod, Hyalella azteca , is substantially more sensitive to pyrethroids than Daphnia

magna , the commonly tested freshwater invertebra te. Information on the acute toxicity of lambda - or gamma -cyhalothrin to Hyalella azteca was not identified in th is problem formulation. Therefore, in order to ensure that risk to sensitive aquatic invertebrates (e.g., amphipods) are appropriately quantified, additional ac ute toxicity testing of the amphipod Hyalella azteca is needed (water column exposure, not sediment-spiked)

. In addition to its high sensitivity, the freshwater amphipod, Hyalella azteca , is recommended as the test species because it is also being requested for chronic freshwater sediment toxi city testing, thereby en abling acute risk to Hyalella to be estimated via porewater expos ure. A study is requested with gamma -cyhalothrin, based on the increased sensitivity of aquatic species to gamma - compared to lambda -cyhalothrin.

Guideline Numbers: 850.1075 Study Title: Freshwater Fish Acute Toxicity (fathead minnow)81 The only available study on chronic toxicity of lambda -cyhalothrin to freshwater fish was conducted with the fathead minnow, Pimephales promelas (MRID 41519001; supplemental). The NOAEC from this study (0.031 μ g a.i./L) is only about a fact or of two less than the 96-h LC 50 of 0.078 μg a.i./L for the most acutely sensitiv e freshwater fish species (golden orfe) to lambda- cyhalothrin. Furthermore, this NOAEC is virtually identical to the 96-h LC 50 of 0.029 μg a.i./L determined for bluegill with gamma -cyhalothrin (MRID 45447215). It is therefore apparent that the fathead minnow is likely not among the most sensitive freshw ater fish species tested to lambda - or gamma -cyhalothrin. In order to estimate the ch ronic toxicity to sensitive freshwater fish species (e.g., bluegill, golden orfe), an acute -chronic ratio (ACR) will likely be needed. This ACR would be applied to the most acutely sensiti ve fish species to estimate its corresponding chronic sensitivity. ACRs should be determined on the same species (in this case, fathead minnow) in order to reduce uncertainty in predicte d chronic toxicity values. However, there are no submitted acute toxicity studies with fathead minnow from which to derive an ACR. Deriving an ACR based on an acutely sensitive species (e. g., bluegill) and a chronica lly insensitive species (fathead minnow) would likely grossly under estimat e chronic risk to sensitive fish species. Without this study, estimation of chronic risks to sensitive fish species will involve substantial uncertainty. Therefore, the Agency is requesting an acute toxicity test of lambda- cyhalothrin to the fathead minnow in order to a ppropriately estimate chronic toxi city to fish based on existing chronic data with fathead minnow . Fathead minnow is one of the recommended test species in the OPPTS test guidelines.

Guideline Numbers: 850.1075, 850.1010 and non-guideline Study Title: Freshwater Fi sh Acute Toxicity (TEP) Freshwater Aquatic Invertebrate Acute Toxicity (TEP) Whole sediment: chronic invertebrates freshwater and marine Because there are registered outdoor uses that ma y result in significant exposure to water bodies,

acute lambda - and gamma -cyhalothrin TEP data with the synergist PBO is requested for freshwater fish and freshwater in vertebrates. The registrations are for cattle ear tags (#773-75) or cattle pour-on treatments (#773-92, #53883-248 and #53883-270).

A total of 4 active product registrations exist for lambda -cyhalothrin and gamma -cyhalothrin formulations with PBO:

• Lambda -cyhalothrin and PBO: # 773-75, #773-92, #53883-248

• Gamma -cyhalothrin and PBO: # 53883-270

Products with the synergist PBO are likely to cau se increased toxicity to nontarget aquatic species. Currently, no data is available to quant ify the difference in toxicity for fish or invertebrates that may be concurrently exposed to lambda - and gamma -cyhalothrin and PBO compared to the active ingredients alone. While these studies are requested for the "TEP," the registrant must submit a protocol prior to conducting these TEP studies that addresses the expected toxicity from differing c oncentration ratios of PBO and th e TGAI that are likely to occur in the aquatic environment. Results from the acu te freshwater toxicity tests can be used to optimize the design of the chronic sediment toxicity test. This approach is being followed by the Agency with TEP testing of PBO and pyrethrins.82 Guideline Number: 850.1350 Study Title: Aquatic Invert ebrate Life-Cycle (freshwater) Previously submitted studies indicate that freshwater invertebrates are among the most chronically sensitive species to lambda - and gamma -cyhalothrin, with chronic effects expected below 1 ng/L. While two supplemental studies ha ve been submitted on the chronic toxicity of lambda -cyhalothrin to Daphnia magna (MRID 41217501, 00152733), the toxicity endpoints derived from these studies are considered hi ghly uncertain. Spec ifically, the exposure concentrations used in these studies varied so much (3X to more than 10X) that maximum and minimum values overlapped among treatments. This excessive variability in exposure concentrations within treatments brings into que stion the ability to accura tely determine a chronic toxicity endpoint from these st udies (e.g., NOAEC). Other guideline de viations were also noted in these two studies (e.g., high light in tensities, use of too few rep licate chambers per treatment, culling of less healthy organisms during the course of the study). Obtaining an accurate chronic NOAEC for freshwater invert ebrates (e.g., daphnids) is critical to future risk assessment since this value will likely be used to estimate chronic toxicity to other more sensitive freshwater invertebrates (e.g., amphipods) which will form the basis of the risk assessment conclusions. As substantial advances in both analytical and biol ogical test methods have occurred over the past two decades (the previously submitted studies were conducted in 1985 and 1989), it is highly likely that a repeat of these st udies would yield results that are much more scientifically defensible. Without this study, estimation of chro nic risks to sensitive freshwater invertebrates (e.g., daphnia, amphipods) will involve substant ial uncertainty. A study is requested with gamma

cyhalothrin, based on the increased sensitivity of aquatic species to gamma - compared to lambda

cyhalothrin.

Guideline Number: Non-guideline Study Title: Whole sediment: chronic invertebrates freshwater and marine No chronic sediment toxicity tests for freshwater or marine invertebrates have been submitted to satisfy the Agency’s updated data requirements for outdoor uses in 40 CFR Part 158 (October 26, 2007). For lambda - and gamma -cyhalothrin, available informa tion indicates that benthic organisms may be exposed via run-off or spray drif t applications used in agricultural, forest, and residential settings. Based on calculations in the most recent EFED assessment for lambda

cyhalothrin (Section 18 Emergenc y Exemption for the Use of Lambda -cyhalothrin in Washington on Asparagus, D379522, August 2010) (see Appendix D for modeling information), the peak sediment porewater EECs predicted for lambda -cyhalothrin (0.00253 μg a.i. /L) exceeds 0.1 of the most sensitive acute LC/EC 50 (0.00048 μg a.i./L for Gammarus pseudolimnaeus ), which satisfies one of the criteria for requiring chronic whole sediment toxicity testing under 40 CFR Part 158. This comparison is based on exposure concentrations predicted for lambda -cyhalothrin and the most sensitive toxicity information for gamma -cyhalothrin. However, the exposure would is expected to be similar for gamma -cyhalothrin based on similar fate properties. Additionally, the rates proposed for asparagus (3 applications of 0.034 kg a.i./ha at 21 day intervals) were not the highest currently registered use rates (see Section 3.2). Chronic effects were also seen in all aquatic taxa tested at levels as low as 0.0002 μg a.i./L (Accession #073989, mysid shrimp).83 The expected half-life of lambda - and gamma -cyhalothrin in sediment (28 – 61 days for aerobic soil metabolism and 21 – 53 days for aerobic aquatic metabolism) is substantially greater than 40 CFR Part 158 criterion of 10 days. The potential for persis tent exposure from lambda - and

gamma -cyhalothrin in sediment is also indicate d by open literature studies on pyrethroids (Weston et al. 2005, Amweg et al. 2006 and Ding et al . 2009).

The third set of trigger criteria for requiring chronic testing (K d > 50, or log K OW >3 or K OC > 1000) is also met for lambda - and gamma -cyhalothrin (for lambda -cyhalothrin K d mean value is 4350, log K OW is 7, and mean K OC value 333,200; for gamma -cyhalothrin K d mean value is 622, log K OW is 5, and K OC mean value is 59,700). The physic ochemical property triggers (K d , K OW and K OC ) reflect the propensity of the chemical to partition onto the partic ulate or organic matter phases of sediments. Exceeding any one of the phys icochemical property triggers listed above is sufficient for indicating the pesticide has reason able potential for parti tioning to the sediment compartment.

For sediment studies involving pyrethroids, chronic whole sediment tests on Hyalella azteca

, Chironomus tentans , and Leptocheirus plumulosus are requested. Although both are freshwater species, Hyalella and Chironomus differ substantially in their ecological niche ( i.e. , epibenthic v. infaunal species), physiology, and th ere is some evidence suggesting Hyalella is among the more sensitive invertebrates to some pyrethroi ds based on water column tests (Anderson et al. 2006, Maund et al. 2002). Lambda - and gamma -cyhalothrin have the potential to enter estuarine/marine water bodies based on current usuage patterns that include coastal areas. Therefore, testing is also required for an estuarine/marine sedi ment-dwelling invertebrate species.

A study is requested with gamma -cyhalothrin, based on the increased sensitivity of aquatic species to gamma - compared to lambda -cyhalothrin.

Guideline Numbers: 850.4150 and 850.4250 Study Title: Vegetative vigor and Seedling emergence, Tier I/ Tier II No acceptable toxicity data are currently available to assess the risk of lambda - and gamma

cyhalothrin to non-target terrestrial plants. Since lambda - and gamma -cyhalothrin have residential outdoor uses, vegetative vigor and seedling emerge nce studies are require d. These phytotoxicity data are needed to assess the impact of pe sticides on endangered a nd threatened non-target terrestrial plants. A study is requested with either lambda - or gamma -cyhalothrin.

Guideline Number: 850.4400 Study Title: Aquatic Vascular Plant Growth- Lemna spp. Tiers I/II No acceptable toxicity data are currently available to assess the risk of lambda - and gamma

cyhalothrin to non-target aqua tic vascular plants. Since lambda - and gamma -cyhalothrin have residential outdoor uses, aquatic vascular plant studies are required. These phytotoxicity data are needed to assess the impact of pesticides on enda ngered and threatened aqua tic vascular plants. A study is requested with either lambda - or gamma -cyhalothrin.84 Table 7.2 lists the status of the ecological effects data requirements for lambda - and gamma cyhalothrin.

Table 7.2. Ecological Effects Data Requirements for lambda - and gamma - cyhalothrin.

Data Requirement Use
Pattern 1 Does EPA Have Data To Satisfy This Requirement?

(Yes, No, or

Partially) Bibliographic Citation Must Additional

Data Be Submitted Under FIFRA

3(c)(2)(B)?

§158.490 TERRESTRIAL ORGANISMS

71-1(a) Acute Avian Oral, Quail/Duck 1,2 Partially 00151594, 45447210, 45447211 Yes 2

71-2(a) Acute Avian Diet, Quail 1,2 Yes 45447212 No

71-2(b) Acute Avian Diet, Duck 1,2 Yes 00151595, 45447213 No

71-3 Wild Mammal Toxicity 1,2 N/A

71-4(a) Avian Reproduction Quail 1,2 Yes 00153505 No

71-4(b) Avian Reproduction Duck 1,2 Yes 00153504, 41512101 No

§158.630 AQUATIC ORGANISMS TESTING

72-1(a) Acute Fish Toxicity Bluegill 1,2 Yes 00151597, 45447215 No

72-1(b) Acute Fish Toxicity (TEP) 1,2 Partially 0015601, 43908812, 00151600, 43908813 and 45447218 Yes 3

72-1(c) Acute Fish Toxicity Rainbow
Trout 1,2 Yes 00151598, 45447217 No

72-2(a) Acute Aquatic Invertebrate 1,2 Yes 00152730, 00151599, 45447219, 45447220 No

72-2(b) Acute Aqua tic Invertebrate (TEP) 1,2 Partially 00151602, 43908811, 00151599, 45447221 Yes 3

72-3(a) Acute Est/Mar Toxicity Fish 1,2 Yes 00153506 No

72-3(b) Acute Est/Mar Toxicity Mollusk 1,2 Yes 00152728 No

72-3(c) Acute Est/Mar Toxicity Shrimp 1,2 Yes 00152728 No

72-3(d) Acute Est/Mar Toxicity Fish (TEP) 1,2 No N/A No

72-3(e) Acute Est/Mar Toxicity Mollusk (TEP) 1,2 No N/A No

72-3(f) Acute Est/Mar Toxicity Shrimp (TEP) 1,2 No N/A No85 Table 7.2. Ecological Effects Data Requirements for lambda - and gamma - cyhalothrin.

Data Requirement Use
Pattern 1 Does EPA Have Data To Satisfy This Requirement?

(Yes, No, or

Partially) Bibliographic Citation Must Additional

Data Be Submitted Under FIFRA

3(c)(2)(B)?

72-4(a) Early Life Stage Fish 1,2 Yes 00152732 No

72-4(b) Life Cycle Aquatic Invertebrate (freshwater) 1,2 No 00152733, 41217501 Yes 4

850.1350 Life Cycle Aquatic Invertebrate (saltwater) 1,2 Yes Acc #073989 No

72-5 Life Cycle Freshwater Fi sh 1,2 Yes 41519001 No

72-6 Aquatic Organism Accumulation 1,2 N/A

72-7(1) Simulated Aquatic Field Study 1,2 N/A

72-7(b) Actual Aquatic Field Study 1,2 N/A

850.1730 Bioaccumulation in Fish 1,2 Yes 00152744, 00152745 No

Whole sediment: chronic invertebrates freshwater & marine 1, 2 No N/A Yes 5

Non-guideline Aquatic Invertebrate Acute Toxicity ( Hyalella ) 1, 2 No N/A Yes 5

850.1075 Freshwater Fish Acute Toxicity (fathead minnow) 1, 2 No N/A Yes 6

§158.540 PLANT PROTECTION

122-1(a) Seed Germ, Seedling Emergence 1,2 No NA Yes

122-2 Aquatic Plant Growth 1,2 No NA Yes

122-1(b) Vegetative Vigor 1,2 No NA Yes

123-1(a) Seed Germ./Seedling Emerg. 1,2 No NA No 7

123-1(b) Vegetative Vigor 1,2 No NA No 7

123-2 Aquatic Plant Growth 1,2 No NA No 8

§158.490 NONTARGET INSECT TESTING

141-1 Honey Bee Acute Contact 1,2 Yes 40052409 No

141-2 Honey Bee Residue on Foliage 1,2 Yes 40436302 No

141-5 Field Test for Pollinators 1,2 NA86 1 Use Patterns: 1=Terrestrial/Food; 2=Terrestrial/Feed.

2 Data are required for one passerine speci es and either on waterfowl or one uplan d game bird species. At this time, only acute oral tests for a game bird species and a waterfowl have been submitted. Data are required for either lambda - or
gamma -cyhalothrin. Registrant is required to submit a protocol for review.

3 Data are required for a TEP acute toxicity study with lambda - or gamma - cyhalothrin and the synergist PBO.

4 Previously submitted studies are not considered acceptable to meet guideline requirements. Data are required for gamma

cyhalothrin.

5 Data requested for gamma -cyhalothrin.

6 Data required for an acute toxicity test of lambda- cyhalothrin to the fathead minnow in order to appropriately estimate chronic toxicity to fish based on existing chronic data with fathead minnow. Fathead minnow is one of the recommended test species in the test guidelines.

7 Required if a tested terrestrial species exhibits a 25 percent or greater detr imental effect in the Tier I study.

8 Required if a tested aquatic species exhibits a 50 per cent or greater detrimental e ffect in a Tier I study.87 8. References

Amweg, E.L., D.P.Weston, and N.M. Ureda. 2005. Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environm ental Toxicology and Chemistry, Vol. 24, No. 4, pp. 966–972

Amweg, E.L., D.P. Weston, C.S. Johnson, J. You and M.J. Lydy. 2006a. Effect of Piperonyl Butoxide on Permethrin Toxicity in the Amphipod Hyalella azteca . Environ. Tox. & Chem. 25(7), pp. 1817-1825.

Amweg, E.L. D.P. Weston, J. You and M.J. Lydy. 2006b. Pyrethroid Insecticides and Sediment Toxicity in Urban Creeks from California and Tennessee. Environ. Sci. Technol. , 2006

, 40 (5), pp 1700–1706.

Amweg, E.L. and D.P. Weston. 2007. Whole-Sediment Toxicity Id entification Evaluation Tools for Pyrethroid Insecticides: I. Piperonyl But oxide Addition. Environ. Toxicol. & Chem., Vol. 26, No. 11, pp. 2389–2396, 2007

Armitage, J.M., & Gobas, F.A.P.C. 2007. A terr estrial food-chain bio accumulation model for POPs. Environmental Science and Technology, 41 , 4019-4025.

Barile, F.A. 2004. Clinical Toxicology: Principles and Mechanisms . Boca Raton, FL: CRC Press.

Bennett E.R., M.T. Moore, C.M. Cooper, and S. Smith, Jr. 2005. Ve getated Agricultural Drainage Ditches for the Mitigation of Pyrethro id-Associated Runoff. Environ. Tox. Chem. 24 (9) pp. 2121–2127.

Bouldin , J.L. , J.L. Farris, M.T. Moore, S. Smith, Jr., W.W. Stephens, and C.M. Cooper. 2005. Evaluated Fate and Effects of Atrazine and Lambda -Cyhalothrin in Vegetated and Unvegetated Microcosms. Environ Toxicol 20: 487–498.

Brown, J.S., M. Sutula, C. Stransky, J. R udolph, and E. Byron, 2010. Sediment Contaminant Chemistry and Toxicity of Freshwater Urban Wetlands in Southern California. Journal of the
American Water Resources Association (JAWRA) 46(2):367-384.

Budd, R, S. Bondarenko, D. Haver, J. Kabashima, and J. Gan. 2007. Occurrence and Bioavailability of Pyrethroids in a Mixed Land Use Watershed. J. Environ. Qual. 36: 1006–1012 (2007).

Clark, J.M and F. Matsumura. 1987. The action of two classes of pyrethroi ds on the inhibition of brain Na-Ca and Ca + Mg ATP hydrolyzing activities of the American cockroach, Comp. Biochem. Physiol. C. 86 (1987) (1), pp. 135–145.88 Cooper, C.M., M.T. Moore, E.R. Bennett, S. Smith, Jr., and J.L. Farris. 2002. Alternative environmental benefits of agri cultural drainage ditches. Verh. Internat. Verein. Limnol. 28 , 1678- 1682.

Corbin, M, W. Eckel, M. Ruhman, D. Spatz, N. Thurman, R. Gangaraju, T. Kuchnicki, R. Mathew, and I. Nicholson. 2006. NAFTA Guidan ce Document for Conducting Terrestrial Field Dissipation Studies. Available at url: http://www.epa.gov/oppefed1/ecorisk_ders /terrestrial_field_dissipation.htm (accessed 06/24/10).

DeCant, J. 2009. Section 3 new use registration for gamma -Cyhalothrin in the product COBALT TM on wheat in the following states: Alabama, Arkansas, Georgia, Illinois, Indiana, Iowa, Kentucky, Louisiana, Michigan, Missour i, North Carolina, Ohio, South Carolina, Tennessee, Virginia, and Wisconsin. Memorand um to V. Eagle and A. Abramovich dated 05/11/09 (DP Barcodes D357895 and D357900). Envir onmental Fate and Effects Division, OPP, OCSPP, USEPA.

Di Toro, D.M., C.S. Zarba, D.J. Hansen, W.J. Berry, R.C. Swartz, C.E. Cowan, S.P. Pavlou, H.E. Allen, N.A. Thomas and P.R. Paquin. 1991. Techni cal basis for establishing sediment quality criteria for nonionic organic chemicals using equilibrium partitioning. Environ. Toxicol. Chem.
10:1541-1583.

Ding, Y., A.D. Harwood, H.M. Foslund, and M.J. Lydy. 2010. Distribution and Toxicity of Sediment-Associated Pesticides in Urban and Agricultural Waterways from Illinois, USA. Environmental Toxicology and Chemistry, Vol. 29, No. 1, pp. 149–157, 2010.

Fojut, T.L. and R.S. Tjeerdema. 2010. Water Quality Criteria Report for Lambda-cyhalothrin. Prepared for the Central Valley Regional Water Qu ality Control Board. University of California, Davis. http://www.swrcb.ca.gov/rwqcb5/wa ter_issues/tmdl/central_valley_p rojects/central_valley_pestic ides/criteria_method/lambda_cyhalothrin/ final_lambda_cyhaloth rin_criteria_rpt.pdf

Food and Agriculture Organization of the United Nations. FAO PESTICIDE DISPOSAL SERIES 8. Assessing Soil Contamination: A Re ference Manual. Appendix 2. Parameters of pesticides that influence pro cesses in the soil. Editorial Group, FAO Information Division: Rome, 2000. http://www.fao.org/DOCREP/003/X2570E/X2570E00.htm

Gan, J., S.J. Lee, W.P. Liu, D.L. Haver, and J. N. Kabashima. 2005. Distribution and Persistence of Pyrethroids in Runoff Sediments. J. Environ. Qual. 34:836–841 (2005).

Giddings, J.M., I. Barber, and W. Warren-Hicks. 2009. Comparative aquatic toxicity of the pyrethroid insecticide lambda -cyhalothrin and its resolved isomer gamma -cyhalothrin. Ecotoxicology (2009) 18:239–249.

Gobas, F.A.P.C., B.C. Kelly and J.A. Arnot. 2003. Quantitative structure activity relationships for89 predicting the bioaccumulation of POPs in terr estrial food webs. QSAR Comb. Sci. 22:329-336.

Gu B.G., H.M. Wang, W.L. Chen, D.J. Cai, Z.J. Shan. 2007. Risk assessment of λ -cyhalothrin on aquatic organisms in paddy field in China. Regulatory Toxicology and Pharmacology 48 (2007) 69–74.

Hamer M.J., U.M. Goggin, K. Muller and S.J. Maund. 1999. Bioavailability of lambda

cyhalothrin to Chironomus riparius in sediment-water and water-only systems. Aquat Ecosys Health Manag 2:403–412 (as cited by He et al. 2008).

Hand, L.H., S.F. Kuet, M.C.G. Lane, S.J. Maund, J. S. Warington, and I.R. Hill. 2001. Influences of Aquatic Plants on the Fate of the Pyrethroid Insecticide Lambda -cyhalothrin in Aquatic Environments. Environ. Tox. Chem. 20(8), pp. 1740–1745.

He, L., J. Troiano, A. Wang, and K. Goh. 2008. Environmental Chemistry, Ecotoxicity, and Fate of Lambda -Cyhalothrin. Reviews of Environmental Contamination and Toxicology . D.M. Whitacre (ed.), Springer 2008. pp 71-91.

Heckmann, L. and N. Friberg. 2005. Macroinvertebrate Community Response to Pulse Exposure with the Insecticide Lambda -cyhalothrin Using In-stream Mesocosm. Environ. Tox. Chem. 24(3), pp. 582–590.

Hill B.D. and D.J. Inaba. 1991. Dissipation of lambda -Cyhalothrin on Fallow vs Cropped Soil. J. Agric. Food Chem. 1991, 39, 2282-2284.

Hintzen, E.P., M.J. Lydy, and J.B. Belden. 2009. Occu rrence and potential toxi city of pyrethroids and other insecticides in bed sediments of urban streams in central Texas. Environ Pollut
157:110–116.

Hodgson, E., & Smart, R. C. (Eds.). 2001. Introduction to Biochemical Toxicology (Third ed.). New York: Wiley-Interscience.

Holmes, R.W., B.S. Anderson, J.W. Hunt, D. B. Crane, A. Mekebri and V. Connor. 2008. “Statewide Investigation of the Role of Pyrethroid Pesticides in Sediment Toxicity in California’s Urban Waterways.” Environ. Sci. Technol. 2008

, 42, 7003–7009.

Hunter, W., Y. Yang, F. Reichenberg, P. Mayer, and J. Gan. 2009. Measuring Pyrethroids in Sediment Pore Water Using Matrix-Solid Phas e Microextraction. Envi ron. Tox. Chem. 28(1), pp. 36–43, 2009.

Jiang, W., K. Lin, D. Haver, S. Qin, G. Ayre, F. Spurlock, and J. Gan. 2010. Wash-off Potential of Urban Use Insecticides on Concrete Su rfaces. Environ. Tox. Chem. 29(6), pp. 1203–1208,
2010.90 Jorgenson, B., and T. Young. 2010. Formulation Effects and the Off-Target Transport of Pyrethroid Insecticides from Urban Hard Surfaces. Environ. Sci. Technol. 2010

, 44, 4951–4957

.
Kumar, A., B. Sharma and R.S. Pandey. 2007. Pr eliminary Evaluation of The Acute Toxicity of Cypermethrin and λ -Cyhalothrin to Channa Punctatus . Bull Environ Contam Toxicol (2007)
79:613–616.

Laskowski, D.A., 2002. Physical and chemical pr operties of pyrethroids. Rev. Environ. Contam. Toxicol. 2002; 174:49-170.

Lao, W, D. Tsukada, D.J. Greenstein, S.M. Bay, a nd K.A. Maruya. 2010. Analysis, Occurrence, and Toxic Potential of Pyrethroid s, and Fipronil in Sediments from and Urban Estuary. Environ. Tox. Chem. 29(4), pp. 843–851, 2010.

Lauridsen, R.B., and N. Friberg. 2005. Stream Macroinvertebr ate Drift Response to Pulsed Exposure of the Synt hetic Pyrethroid Lambda -Cyhalothrin. Environmental toxicology 20(5) pp.
513-521.

LeBlanc, L. & B. Perkins. 2009. Pyrethroid Analysis for Maine Board of Pesticide Control. University of Maine Food and Chemical Safety Laboratory, Orono Maine. An e:mail communication from G. Fish to R. Gebken, da ted 11/02/09 and forwarded to EFED on 11/19/09. Original communication from L. LeBlanc to G. Fish and H. Jennings, dated 05/25/09.

Lee, D. 2009. Pyrethroid Pesticide Contamina tion of Urban Runoff in Stormwater Detention Ponds. Pesticides in Stormwater Runoff. May 11, 2009. 21 pp.

Leistra, M., A.J. Zweers, J.S. Warinton, S.J. H. Crum, L.H. Hand, W.H.J. Beltman, and S.J. Maund. 2003. Fate of the insecticide lambda -cyhalothrin in ditch en closures differing in vegetation density. Pest Manag Sci 60:75–84.

Liu, W., J.J. G an , S. L ee , and J.N. Kabashima. 2004. Phase Di stribution of Synthetic Pyrethroids in Runoff and Stream Water. Environ Tox Chem 23(1) pp. 7–11.

Maher, I, N. Birchfield, P. Jennings and S. Abel. 2004. Ecol ogical risk assessment and human drinking water assessment for gamma -cyhalothrin use on multiple agricultural use sites and noncropped areas. Memorandum to W. Sproat and G. LaRocca dated 03/19/04 (DP Barcodes D288057, D289794, D289797, D289799, D289798 and D289801). Environmental Fate and Effects Division, OPP, OCSPP, USEPA.

Matsumura, F. 1985. Toxicology of in sects. 2nd ed. Plenum New York.

Maund, S.J., M.J. Hamer, J.S. Warinton, and T.J. Kedwards. 1998. Aquatic Ecotoxicology of the Pyrethroid Insecticide Lambda -cyhalothrin: Considerations for Higher-Tier Aquatic Risk Assessment. Pestic. Sci. 1998, 54, 408-417.91 Meléndez, J.L. and Hoffmann, M. 2006. Enviro nmental Fate and Ecological Risk Assessment for Section 3 Registration of Lambda -cyhalothrin, an Insecticide for New Uses on Cereal Grains, Cucurbit Vegetables, Grass Forage, Fodder a nd Hay, Wild Rice and Tuberous and Corm Vegetables. Memorandum to G. LaRocca a nd D. Rosenblatt dated 12/29/06 (DP Barcode D324224 and D313316). Environmental Fate and Effects Division, OPP, OCSPP, USEPA.

Meléndez, J.L. and A. Solliday. 2008. EFED New Use Registration for Lambda -cyhalothrin on Non-bearing Citrus Orchards. Memorandum to O. Odiott, K. Nesci and M. Johnson dated 11/04/08 (DP Barcode D355940). Environmental Fate and Effects Division, OPP, OCSPP, USEPA.

Moore M.T., E.R. Bennett, C.M. Cooper, S. Smith Jr., F.D. Shields Jr., C.D. Milam, and J.L. Farris. 2001. Transport and fate of atrazine and lambda -cyhalothrin in an ag ricultural drainage ditch in the Mississippi Delta, USA. Agriculture, Ecosystems and Environment 87 (2001) 309–
314.

Moore M.T., R.E. Lizotte Jr. and S. Smith Jr. 2007. Responses of Hyalella azteca to a Pyrethroid Mixture in a Constructed Wetland. Bu ll Environ Contam Toxicol (2007) 78:245–248.

Moore, M.T., C.M. Cooper, S. Smith, Jr., R.F. Cullum, S.S. Knight, M.A. Locke and E.R. Bennett. 2009. Mitigation of two pyrethroid in secticides in a Mississi ppi Delta constructed wetland. Environmental Pollution 157 (2009) 250–256.

Ramasamy, S., I. Maher, P. Jennings, and S. Ab el. 2002. Section 3 request for new uses of lambda cyhalothrin (P.C. Code: 128897) on peas and beans, fruiting vegetables, canola, sugarcane, sorghum, wheat, wheat ha y and other small grains, peanut, hay, pome fruit, stone fruit, tree nuts, termite barrier, tobacco, non-cropla nd and trees (conifer and deciduous trees). Memorandum to A. Layne and W. Spro at dated 06/12/02 (DP Barcodes D262918, D262919, D279087 and D279088). Environmental Fate and Effects Division, OPP, OCSPP, USEPA.

Rexrode, M. and J.L. Meléndez. 2003. EF ED’s rationale for choosing Cypermethrin, Esfenvalerate, Bifenthrin, and Cyfl uthrin for sediment testing as discussed with the Pyrethroid Working Group (PWG). Memorandum to M. Johnson & G. LaRocca dated 12/22/03. Environmental Fate and Effects Division, OPP, OPPTS, USEPA.

Smith Jr., S., R.E. Lizotte Jr. 2007. Influence of Selected Water Quality Characteristics on the Toxicity of λ -Cyhalothrin and γ -Cyhalothrin to Hyalella azteca . Bull Environ Contam Toxicol (2007) 79:548–551.

Solomon, K.R., J.M. Giddings, and S.J. Maund. 2001. Probabilistic Risk Assessment of Cotton Pyrethroids: I. Distributional Analyses of La boratory Aquatic Toxicity Data. Environ. Tox. Chem., 20(3), pp. 652–659, 2001.92 Stout II, D.M., K Bradham, P.P. Egeghy, P. Jones, C.W. Croghan, P.A. Ashley, E. Pinzer, W. Friedman, M.C. Brinkman, M.G. Nishioka an d D.C. Cox. 2009. American Healthy Homes Survey: A National Study of Residential Pe sticides Measured from Floor Wipes. Environ. Sci. Technol., 2009 , 43, 4294–4300.

Trimble, A.J, D.P. Weston, J.B. Belden, and M.J. Lydy. 2009. Identification and Evaluation of Pyrethroid Insecticide Mixtures in Urban Sedi ments. Environ Toxicol & Chem 26 (8) pp. 1687–
1695.

Ureda, N. 2004. Sediment LC 50 Analyses of the Pyrethroid Pesticides Cyfluthrin, Deltamethrin, and Lambda -Cyhalothrin. [Available at url: http://nature.berkeley.edu/classes/es196/projects/2004final/Ureda.pdf accessed 06/25/10].

U.S. Environmental Protection Agency. 1998. Guid elines for Ecological Risk Assessment. Risk Assessment Forum, Office of Research and De velopment, Washington, D.C. EPA/630/R95/002F. April 1998.

U.S. Environmental Protection Agency. 1999. FIFRA Scientific Advisory Panel Meeting, February 23, 1999 held at the Holiday Inn Hotel, Arlington, VA

. SAP Report No. 99-03A. March 25, 1999. Office of Pesticide Programs. Available at url: http://www.epa.gov/scipoly/sap/m eetings/1999/022399_mtg.htm#materials (Accessed December 15, 2009)

U.S. Environmental Protection Agency. 2000. Risk Characterization Handbook. Science Policy Council, U.S. Environmental Protection Agenc y, Washington, D.C. 20460. EPA 100-B-00-002. December 2000.

U.S. Environmental Protection Agency. 2002. Technical Basis for the derivation of Equilibrium Partitioning Sediment Guidelines (ESGs) for the Protection of Benthi c Organisms: Nonionic Organics [Draft]. EPA Do cument No. 822R02041. October 2002.

U.S. Environmental Protection Agency. 2004a. Ecological risk assessment and human drinking water assessment for gamma-cyhalothrin use on mu ltiple agricultural us e sites and non-cropped areas. DP barcode: 289801, 289799, 289797, 289794, 289798, 288057. March 19, 2004.

U.S. Environmental Protection Agency. 2004b. Ov erview of the Ecological Risk Assessment Process in the Office of Pestic ide Programs, U.S. Environmental Protection Agency. Endangered and Threatened Species Effects Determinations . Office of Prevention, Pesticides and Toxic Substances, Office of Pesticide Prog rams, Washington, D.C. January 23, 2004.

U.S. Environmental Protection Agency. 2005. Generic Format and Guidance for the Level I Screening Ecological Risk Assessments Conducte d in the Environmental Fate and Effects Division. Office of Pesticide Program s, Washington, D.C. January 24, 2005.

U.S. Environmental Protection Agency. 2008. OPPTS 835.6100 Terrestrial Field Dissipation

.93 EPA 712-C-08-020. October 2008. Office of Preventi on, Pesticides, and Toxic Substances. United States Environmental Protection Agency. Available at http://www.epa.gov/opptsfr s/publications/835_6100.pdf (Accessed March 31, 2010).

U.S. Environmental Protection Agency. 2009. A Set of Scientific Issues Being Considered by the EPA Regarding: Evaluation of the Common Mechanis m of Action of Pyrethroid Pesticides. SAP Minutes No. 2009-07. FIFRA SAP Meeting held 6/16/09 in Arli ngton, VA. Meeting Minutes dated 9/9/09.

U.S. Fish and Wildlife Service (USFWS) and Na tional Marine Fisheries Service (NMFS). 1998. Endangered Species Consultation Handbook: Pr ocedures for Conducting Consultation and Conference Activities Under Section 7 of the Enda ngered Species Act. Fi nal Draft. March 1998.

Van Wijngaarden , R.P.A. , T.C.M. Brock, P.J. van den Brink, R. Gylstra, and S.J. Maund. 2006. Ecological Effects of Spring and Late Summer Applications of Lambda -Cyhalothrin on Freshwater Microcosms. Arch. E nviron. Contam. Toxicol. 50, 220–239 (2006).

Van Wijngaarden, R.P.A. I. Barber, and T.C. M. Brock. 2009. Effects of the pyrethroid insecticide gamma -cyhalothrin on aquatic invertebrates in laboratory and outdoor microcosm tests. Ecotoxicology (2009) 18:211–224.

Wang, W., D.J. Cai, Z.J. Shan, W.L. Chen, Nick Poletika, and X.W. Gao. 2007. Comparison of the acute toxicity for gamma -cyhalothrin and lambda -cyhalothrin to zebra fish and shrimp. Regulatory Toxicology and Pharmacology 47 (2007) 184–188.

Weston, D.P., J. You, and M.J. Lydy. 2004. Distri bution and Toxicity of Sediment-Associated Pesticides in Agriculture-Domina ted Water Bodies of California’ s Central Valley. Environ. Sci. Technol. 2004 , 38, 2752-2759.

Weston, D.P., R.W. Holmes, J. You and M.J. Lydy. 2005. Aquatic Toxicity Due to Residential Use of Pyrethroid Insecticides. Environ. Sci. Technol. , 2005

, 39 (24), pp 9778–9784.

Weston, D. 2007. Impacts of Pyrethroid Pesticides on Water Quality from Urban and Agricultural Sectors. Conference Proceed ings; California Plant and Soil Conference: Opportunities for California Agriculture. Ca lifornia Chapter of the American Society of Agronomy, pp. 35-37.

Weston, D.P., J. You, A.D. Harwood and M. J. Lydy. 2009a. Whole Sediment Toxicity Identification Evaluation Tools for Pyrethroid Insecticides: III. Temperature Manipulation. Environ. Tox. & Chem., Vol. 28, No. 1, pp. 173–180, 2009

Weston, D.P., R.W. Holmes, and M. J. Lydy. 2009b. Residential runo ff as a source of pyrethroid pesticides to urban creeks. E nvironmental Pollution 157 (2009) 287–29494 Weston D.P. and C.J. Jackson. 2009. Use of Engineered Enzymes to Identify Organophosphate and Pyrethroid-Related Toxicity in Toxicity Identification Evaluations. Environ. Sci. Technol. 2009, 43, 5514–5520.

Weston, D.P. and M.J. Lydy. 2010. Urban and Agricult ural Sources of Pyrethroid Insecticides to the Sacramento-San Joaqui n Delta of California. Environ. Sci. Technol. 2010, 44, 1833–1840.

Wheelock, C.E., J.L. Miller, M.J. Miller, S.J. Gee, G. Shan, and B.D. Hammock. 2004. Development of Toxicity Identification Evaluati on Procedures for Pyrethroid Detection Using Esterase Activity. Envi ron. Tox. Chem. 23(11), pp. 2699–2708, 2004.

Wheelock, C.E., J.L. Miller, M.J. Miller, B.M. Ph illips, S.A. Huntley, S.J. Gee, R.S. Tjeerdema, and B.D. Hammock. 2006. Use of Carboxylestera se Activity to Remove Pyrethroid-Associated Toxicity to Ceriodaphnia Dubia and Hyalella azteca in Toxicity Identific ation Evaluations. Environ. Toxicol. Chem. 25(4): 973–984.

Willis, G.H. and L.L. McDowell. 1987. Pesticide persistence on foliage. Reviews of Environmental Contamination and Toxicology, Vol. 100, page 23 (Springer-Verlag, New York, Inc)

Woudneh, M.B and D.R. Oros. 2006. Pyrethroid s, pyrethrins, and piperonyl butoxide in sediments by high-resolution gas chromatography/ high-resolution mass spectrometry. J. of Chromatography A 1135 (2006) 71–77.

Xu, C., J. Wang, W. Liu, G.D. Sheng, Y. Tu, and Y. Ma. 2008. Separation and Aquatic Toxicity of Enantiomers of the Pyrethroid Insecticide Lambda -cyhalothrin. Environ. Tox. Chem. 27(1), pp. 174–181, 2008.

Xu, Y., J. Gan, Z. Wang, and F. Spurlock. 2008. Effect of Aging on Desorption Kinetics of Sediment-Associated Pyrethroids. Environ. Tox. Chem. 27(6), pp. 1293–1301, 2008.

Yang, W., F. Spurlock, W. Liu, and J. Gan. 2006. Inhibition of Aquatic T oxicity of Pyrethroid Insecticides by Suspended Sediment. Environ. Tox. Chem. 25(7), pp. 1913–1919, 2006.

Yang, W.C., W. Hunter, F. Spurlock and J. Ga n. 2007. Bioavailability of Permethrin and Cyfluthrin in Surface Waters with Low Levels of Dissolved Organic Matter. J. Environ. Qual. 36:1678–1685 (2007).

Zhou , J. , S. Rowland, and R.F. Mantour a. 1995. Partition of Synthe tic Pyrethroid Insecticides Between Dissolved and Particulate Phases. Wat. Res. 29(4), pp. 1023-1031, 1995.95 9. Fate and Ecotoxicity Bibliography



### Lambda -Cyhalothrin Environmental Fate Bibliography

161-1 Hydrolysis

MRID Citation Reference

151604 Collis, W.; Leahey, J. (1984) PP321: Hydrolys is in Water at pH 5, 7 and 9: Report No. RJ 0338B. Unpublished study prepared by J ealotts Hill Research Station, ICI Plant Protection Division. 20 p.

40052404 Wagner, J. (1987) Environmental Fate Data Overview and Summary for Resubmission for PP321 on Cotton: [Response to EPA's Co mments]. Unpublished study prepared by ICI Americas Inc. 36 p. 

### 161-2 Photodegradation-water

MRID Citation Reference

151605 Curl, E.; Leahey, J.; Lloyd, S. (1984) PP321: Aqueous Photolysis at pH 5: Report No. RJ 0362B. Unpublished study prepared by J ealotts Hill Research Station, ICI Plant Protection Division. 23 p.

40052404 Wagner, J. (1987) Environmental Fate Data Overview and Summary for Resubmission for PP321 on Cotton: [Response to EPA's Co mments]. Unpublished study prepared by ICI Americas Inc. 36 p.

44861501 Priestley, D.; Leahy, J. (1988) PP321: Aqueous Photolysis at pH 5: Lab Project Number: RJ 0605B. Unpublished study prepared by Zeneca Agrochemicals. 61 p.

44861508 Hand, L.; Mehta, P. (1999) Lambda-Cyhalothrin: Degradation in an Aquatic Microcosm: Lab Project Number: 98JH083: RJ2730B. Unpublished study prepared by Zeneca Agrochemicals. 69 p. 

### 161-3 Photodegradation-soil

MRID Citation Reference

151606 Curl, E.; Leahey, J.; Lloyd, S. (1984) PP321: Photodegradation on a Soil Surface: Report No. RJ 0358B. Unpublished study prepa red by Jealotts Hill Research Station, ICI Plant Protection Divi- sion. 36 p.

40052404 Wagner, J. (1987) Environmental Fate Data Overview and Summary for Resubmission for PP321 on Cotton: [Response to EPA's Co mments]. Unpublished study prepared by ICI Americas Inc. 36 p.

40052405 Parker, S.; Leahey, J. (1986) PP321: Photodegradation on a Soil Surface: Laboratory Project ID: RJ0537B. Unpublished study prepar ed by ICI Americas Inc., Jealott's Hill96 Research Station. 55 p.



### 162-1 Aerobic soil metabolism

MRID Citation Reference

151607 Bharti, H.; Bewick, D.; White, R. ( 1985) PP563 and PP321: Degrada- tion in Soil: Report No. RJ0382B. Unpublished study prepared by Jealotts Hill Research Station, ICI Plant Protection Divi- sion. 66 p.

44861504 Harvey, B. (1996) PP563 and PP321: Degradation in Soil: Report Addendum Number 1): Lab Project Number: RJ 0382B-ADD1. U npublished study prepared by Zeneca Agrochemicals. 24 p.

44861505 Shi, C.; Ericson, J. (1998) (Carb on-14)R211133 (Ref. XV), A Metabolite of LambdaCyhalothrin: Rate of Degradation in Soil under Aerobic Laboratory Conditions: Lab Project Number: RR98-019B. Unpublished study prepared by Zeneca Ag Products. 41
p.


### 162-2 Anaerobic soil metabolism

MRID Citation Reference

151607 Bharti, H.; Bewick, D.; White, R. ( 1985) PP563 and PP321: Degrada- tion in Soil: Report No. RJ0382B. Unpublished study prepared by Jealotts Hill Research Station, ICI Plant Protection Divi- sion. 66 p. 

### 162-3 Anaerobic aquatic metab.

MRID Citation Reference

44075504 Wagner, J. (1996) Karate Insecticide (Containing Lambda-Cyhalothrin): Discussion of Environmental Fate Data Requirements to Support Registration on Rice: Lab Project Number: ZA0724961. Unpublished study prepared by Zeneca Ag Products. 10 p.

44367401 Tambling, D.; Goldsby, G.; Labatore, D. et al. (1997) (Carbon 14)-Lambdacyhalothhrin: Anaerobic Aquatic Soil Me tabolism: Lab Project Number: PMS 420: WINO 15859: RR 96-102B. Unpublished st udy prepared by Zeneca Ag Products (Western Research Center) 69 p. 

### 162-4 Aerobic aquatic metab.

MRID Citation Reference

44075504 Wagner, J. (1996) Karate Insecticide (Containing Lambda-Cyhalothrin): Discussion of Environmental Fate Data Requirements to Support Registration on Rice: Lab Project Number: ZA0724961. Unpublished study prepared by Zeneca Ag Products. 10 p.

44367402 Tambling, D.; Goldsby, G.; Labatore, D. et al. (1997) (Carbon 14)-Lambda-97 cyhalothhrin: Aerobic Aquatic Soil Metabo lism: Lab Project Number: PMS 421: WINO 15858: RR 96-094B. Unpublished study prepared by Zeneca Ag Products (Western Research Center) 77 p. 

### 163-1 Leach/adsorp/desorption

MRID Citation Reference

151608 Stevens, J.; Bewick, D. (1985) PP563 and PP321: Leaching of PP563 and PP321 and Their Degradation Products in Soil Columns: Re- port No. RJ 0408B. Unpublished study prepared by Jealotts H ill Research Station, ICI Plant Protection Division. 17 p.

152748 Stevens, J.; Poole, N. (1981) Cy halothrin: Leaching on Soil Thick- layer Chromatograms: No. 6/HA/003802: Report No. RJ0206B. Un- published study prepared by Imperial Chemical Industries PLC. 29 p.

40052404 Wagner, J. (1987) Environmental Fate Data Overview and Summary for Resubmission for PP321 on Cotton: [Response to EPA's Co mments]. Unpublished study prepared by ICI Americas Inc. 36 p.

40052406 Vickers, J.; Bewick, D. (1986) PP321: Adsorption and Desorption in Soil: Laboratory Project ID: RJ0535B. Unpublished study pre- pared by ICI Americas Inc., Jealott's Hill Research Station. 108 p.

44861503 Muller, K.; Goggin, U.; Lane, M. ( 1996) Lambda-Cyhalothrin: Adsorption and Desorption Properties in Soil and Sediment: Lab Project Number: 94JH243. Unpublished study prepared by Zeneca Agrochemicals. 56 p.

44861509 Kuet, S.; Lane, M. (1999) Lambda-Cyhaloth rin: Aged Desorption in Soil: Lab Project Number: 98JH135: RJ2761B. Unpublished study prepared by Zeneca Agrochemicals. 36 p. 

### 164-1 Terrestrial field dissipation

MRID Citation Reference

40052404 Wagner, J. (1987) Environmental Fate Data Overview and Summary for Resubmission for PP321 on Cotton: [Response to EPA's Co mments]. Unpublished study prepared by ICI Americas Inc. 36 p.

40052407 Bewick, D.; Bartlett, D.; Hendl ey, P. (1986) PP321: Fate of Radio- labelled Material in Soil under Field Conditions: Laboratory Project ID: RJ0529B. Unpublished study prepared by ICI Americas Inc., Jealo tt's Hill Research Station. 159 p. 

### 164-2 Aquatic field dissipation

MRID Citation Reference

44075504 Wagner, J. (1996) Karate Insecticide (Containing Lambda-Cyhalothrin): Discussion of Environmental Fate Data Requirements to Support Registration on Rice: Lab Project Number: ZA0724961. Unpublished study prepared by Zeneca Ag Products. 10 p.98 44367403 Patterson, S.; Francis, P.; Robbins, J. et al. (1997) Lambda-cyhalothhrin: Aquatic Field Dissipation after Application to Rice in Mississippi During 1996: Lab Project Number: LCYH-96-SD-01: WINO 23631: RR 97-002B . Unpublished study prepared by Zeneca Ag Products (Western Research Center) 143 p.

44367404 Patterson, S.; Francis, P.; Robbins, J. et al. (1997) Lambda-cyhalothhrin: Aquatic Field Dissipation after Application to Rice in California During 1996: Lab Project Number: LCYH-96-SD-02: 94-CA-96-592: WINO 15346. Unpublished study prepared by Zeneca Ag Products (Western Research Center) 146 p.



### 165-4 Bioaccumulation in fish

MRID Citation Reference

152740 ICI Americas Inc. (1985) Karate Inse cticide (Containing PP321): Environmental Fate. Unpublished compilation. 27 p.

152744 Yamauchi, S.; Yamauchi, F.; Shigeoka, T.; et al. (1984) PP-563 (Cyhalothrin): Accumulation in Fish (Carp) in a Flow -through Water System: Report No. 58-367. Unpublished study prepared by Mitsubishi-Kasei Institute of Toxicological & Environmental Sciences. 53 p.

152745 Leahey, J.; Parker, S. (1985) Cyhalothrin: Characterisation of Re- sidues Accumulated by Carp Continuously Exposed to [Carbon-14]- Cyhalothrin: Report No. RJ0407B. Unpublished study prepared by Imperial Chemical Industries PLC. 22 p.

152746 Hamer, M.; Hill, I. (1985) Cyhalothrin: The Accumulation of Cyhalo- thrin and Its Degradation Products by Channel Catfish & Daphnia magna in a Soil/Water System: Report No. RJ0427B. Unpublished study prepar ed by Imperial Chemical Industries PLC. 40 p.

40052404 Wagner, J. (1987) Environmental Fate Data Overview and Summary for Resubmission for PP321 on Cotton: [Response to EPA's Co mments]. Unpublished study prepared by ICI Americas Inc. 36 p.



### Gamma -Cyhalothrin Environmental Fate Bibliography

45447409. Smith, J.K. and A.D. Thomas. 2001. Hydrolysis of 14 C-XDE-225 in natural water and buffered water as a function of pH. U npublished study performed, sponsored and submitted by Global Environmental Chemistry Laboratory- Indianapolis Lab, Dow AgroSciences LLC, Indianapolis, Indiana. Laboratory Study ID: 000379. Experimental start November 13, 2000, and termination May 10, 2001 (p. 3). Fi nal report issued May 23, 2001.

45447410. Yoder, R.N. 2001. Aerobic soil degr adation of lambda-cyhalothrin and XDE-225 formulated as a capsule suspension. Unpublished study performed, sponsored and submitted by Dow AgroSciences LLC, Indianapolis, IN. Study ID No.: 010008. Experiment initiation February 6, 2001, and completion May 16, 2001 (p. 3). Final report issued May 23, 2001.

45447411. Cook, W.L. 2001. Aerobic soil degrad ation of XDE-225 and cyhalothrin at 25 ° C. Unpublished study performed, sponsored and submitted by Dow AgroSciences LLC,99 Indianapolis, IN. Study ID No.: 990065. Experiment initiation September 6, 2000, and completion May 1, 2001 (p. 3). Fi nal report issued June 1, 2001.

45447412. Yoder, R.N. 2001. Aerobic aquatic degradation of XDE-225. Unpublished study performed, sponsored and submitted by Dow AgroSciences LLC, Indianapolis, IN. Study ID No.: 010009. Experiment initiation March 26, 2001, and completion May 3, 2001 (p. 3). Final report issued May 25, 2001.

45447413. Cook, W.L. and A.D. Thomas. 2001. Batc h equilibrium sorption of XDE-225 and cyhalothrin on four soils. Unpublished study pe rformed, sponsored , and submitted by Global Environmental Chemistry Laboratory- Indianapo lis Lab, Dow AgroSciences LLC, Indianapolis, Indiana. Laboratory Study ID: 000307. Experiment al initiation April, 2 000, and completion July, 2000 (p. 3). Final report issued May 29, 2001.

45794902. Roberts, D.W., D.R. Foster and G.E. Schelle. 2002. Terrestrial dissipation of XDE225. Unpublished study performed by Dow AgroScie nces LLC, Indianapolis, IN and AGVISE Laboratories, Inc., Northwood, ND, and sponsored and submitted by Dow AgroSciences LLC, Indianapolis, IN. Laboratory Study ID: 010038.01. Experiment initiation April 30, 2001 and completion January 23, 2002 (p. 3). Fi nal report issued August 26, 2002.

46394702. Yoder, R.N., K.P. Smith, J.L. Balcer, and S. Hilla. 2003. Aqueous photolysis of XDE-225 in pH 5 buffer under xenon light. Un published study performed, sponsored, and submitted by Dow AgroSciences LLC, Indianap olis, IN. Dow AgroSciences Study Number: 020015. Experimental start date April 10, 2002, and completion date April 18, 2003 (p. 6). Final report issued May 6, 2003.



### Lambda -Cyhalothrin Ecotoxicology Bibliography

71-1 Avian Singl e Dose Oral Toxicity

MRID Citation Reference

151594 Roberts, N.; Fairley, C. (1984) The Acute Oral Toxicity (LD50) of PP321 to the Mallard Duck: Report No. ICI 438BT/831011. Unpub- lished study prepared by Huntingdon Research Centre. 17 p.

40052408 Wagner, J. (1987) Fish and Wildlife Data Overview and Summary for Resubmission for PP321 on Cotton: [Response to EPA's Comments]. Unpublished study prepared by ICI Americas Inc. 50 p.

42291107 Hakin, B.; Johnson, A.; Anderson, A.; et al. (1991) Fonofos/LambdaCyhalothrin: Acute Oral Toxicity (LD50) to Mallard Duck of a 240/4 g/kg GR Formulation: Lab Project Num ber: ISN 240/9193. Unpublished study prepared by Huntingdon Resear ch Centre Ltd. 40 p.

42291108 Hakin. B.; Johnson, A.; Anderson, A.; et al. (1991) Fonofos/LambdaCyhalothrin: Dietary Toxicity (LC50) to Mallard Duck of a 200/4 g/kg GR100 Formulation: Lab Project Number: ISN 242/9158. Unpublished study prepared by Huntingdon Resear ch Centre Ltd. 30 p.



### 71-2 Avia n Dietary Toxicity

MRID Citation Reference

151595 Roberts, N.; Fairley, C.; Anderson, A.; et al. (1985) The Subacute Dietary Toxicity of PP321 to the Mallard Duck: Report No. ISN 46BT/85171. Unpublished study prepared by Hunt ingdon Research Centre. 34 p.

151596 Roberts, N.; Fairley, C.; Anderson, A.; et al. (1985) The Subacute Dietary Toxicity of PP321 to the Bobwhite Quail: Report No. ISN/45BT/841287. Unpublished study prepared by Hunt ingdon Research Centre. 34 p.

40052408 Wagner, J. (1987) Fish and Wildlife Data Overview and Summary for Resubmission for PP321 on Cotton: [Response to EPA's Comments]. Unpublished study prepared by ICI Americas Inc. 50 p.

42291109 Hakin, B.; Johnson, A.; Anderson, A.; et al. (1991) Fonofos/LambdaCyhalothrin: Dietary Toxicity (LC50) to Bobwhite Quail of a 200/4 g/kg GR Formulation: Lab Project Number : ISN 241/901822. Unpublished study prepared by Huntingdon Resear ch Centre Ltd. 30 p.



### 71-4 Avian Reproduction

MRID Citation Reference

153504 Roberts, N.; Fairley, C.; Chanter, D.; et al. (1982) The Effect of the Dietary Inclusion of Cyhalothrin on Reproduction in the Mallard Duck: Study No. JX0089: Report No. 375/82701. U npub- lished study prepared by Huntingdon Research Centre. 178 p.

153505 Roberts, N.; Fairley, C.; Chanter, D.; et al. (1982) The Effect of the Dietary Inclusion of Cyhalothrin on Reproduction in the Bobwhite Quail: Study No.: JX0090: Report No.: 376/82768. U npublished study prepared by Huntingdon Research Centre. 207 p.

41512101 Beavers, J.; Hoxter, K.; Jaber, M. (1990) PP321: A One-Generation Reproduction Study with the Mallard (Anas platyrhynchos): Lab Project Number: 123-143. Unpublished study prepared by Wildlife International Ltd. 192 p. 

### 72-1 Acute Toxicity to Freshwater Fish

MRID Citation Reference

151597 Hill, R. (1984) PP321: Determinatio n of Acute Toxicity to Rainbow Trout (...): Report No. BL/B/2405. Unpub lished study prepared by Imperial101 Chemical Industries Ltd. 19 p.

151598 Hill, R. (1984) PP321: Determinatio n of Acute Toxicity to Bluegill Sunfish (...): Report No. BL/B/2406. Unpub lished study prepared by Imperial Chemical Industries Ltd. 19 p.

151600 Hill, R. (1985) PP321: Determination of Acute Toxicity of a (...) EC Formulation to Rainbow Trout (...) : Report No. BL/B/2609. Unpublished study prepared by Imperial Chemical Industries Ltd. 13 p.

151601 Hill, R. (1985) PP321: Determination of Acute Toxicity of (...) EC Formulation to Bluegill Sunfish: Report No. BL/B/2610. Unpub- lished study prepared by Imperial Chemical Industries Ltd. 13 p.

152738 Hill, R. (1984) PP890: Determinatio n of Acute Toxicity to Rainbow Trout (Salmo gairdneri): Study No. M027/B: Report No. BL/B/2457. Unpublished study prepared by Imperial Chemical Industries PLC. 17 p.

42291110 Tapp, J.; Sankey, S.; Caunter, J.; et al. (1990) Fonofos and LambdaCyhalothrin: Acute Toxicity to Rainbow Trout (Salmo gairdneri) of a 200/4 g/kg GR Formulation: Lab Project Number: T545/A FT86/90: BL3951/B. Unpublished study prepared by Imperial Chemical Industries PLC. 27 p.

42291111 Tapp, J.;Sankey, S.;Caunter, J.;et al. (1990) Fonofos and LambdaCyhalothrin: Acute Toxicity to Bluegill Sunfish (Lepomis macrochirus) of a 200/4 g/kg GR Formulation: Lab Project Number: T545/B FT87/90: BL3984/B. Unpublished study prepared by Imperial Chemical Industries PLC. 27 p.

43908812 Kent, S.; Sankey, S.; Caunter, J.; et al. (1995) Lambda-Cyhalothrin: Acute Toxicity to Bluegill Sunfish ( Lepomis macrochirus) of a 25 CS Formulation: Lab Project Number: AA1091/C: BL5380/B. Unpublished study prepared by Brixham Environmental Lab. 24 p.

43908813 Kent, S.; Sankey, S.; Caunter, J.; et al. (1995) Lambda-Cyhalothrin: Acute Toxicity to Rainbow Trout (Oncorhynchus mykiss) of a 25 CS Formulation: Lab Project Number: AA1091/B: BL5379/B. Unpublished study prepared by Brixham Environmental Lab. 24 p.

44584001 Kent, S.; Shillabeer, T. (1997) Lambda-Cyhalothrin: Acute Toxicity to Golden Orfe (Leuciscus idus): Lab Project Number: BL6142/B. Unpublished study prepared by Zeneca Limited. 22 p.

45447216 Marino, T.; Rick, D. (2001) XR-2 25 and Lambda-cyhalothrin: An Acute Toxicity Comparison Study with the Bluegill Sunfish, Lepomis macrochirus Rafinesque: Lab Project Number: 001074(B). Unpublished study prepared by The Dow Chemical Company. 67 p.



### 850.1075 Fish acute toxi city test, freshwater and marine

MRID Citation Reference

45447217 Machado, M. (2001) XDE-225 and Lambda-cyhalothrin: Comparative Toxicity to Rainbow Trout (Oncorhynchus mykiss) under Flow-Through102 Conditions: Lab Project Number: 12550.6140: 011056. Unpublished study prepared by Springborn L aboratories, Inc. 76 p. 

### 72-2 Acute Toxicity to Freshwater Invertebrates

MRID Citation Reference

151599 Farrelly, E.; Hamer, M.; Hill, I. (1984) PP321: Toxicity to First Instar Daphnia magna: Report No. RJ 0359B. Unpublished study prepared by Jealotts Hill Research Station, ICI Plant Protection Division. 13 p.

151602 Farrelly, E.; Hamer, M.; Hill, I. (1985) PP321: Toxicity of Formu- lations JF9509 and GFU383C to First Instar Daphnia magna: Re- port No. RJ 0426B. Unpublished study prepared by J ealott's Hill Research Station, ICI Plant Protection Division. 19 p.

152730 Hamer, M.; Farrelly, E.; Hill, I. (1985) PP321: Toxicity to Gam- marus pulex: Report No. RJ0414B. Unpublished study prepared by Imperial Chemical Industries PLC. 29 p.

152733 Hamer, M.; Farrelly, E.; Hill, I. (1985) 21 Day Daphnia magna Life-cycle Study: Study No. PP321/CN/02: Repor t No. RJ0541B. Unpublished study prepared by Imperial Chemical Industries PLC. 35 p.

40052408 Wagner, J. (1987) Fish and Wildlife Data Overview and Summary for Resubmission for PP321 on Cotton: [Response to EPA's Comments]. Unpublished study prepared by ICI Americas Inc. 50 p.

40515901 Kennedy, J.; Cole, J.; Ekoniak, P.; et al. (1988) PP321: Evalua- tion of the Impact of Run-off and Spray-drift on Aquatic Ecosys- tems, using USA Experimental Ponds (Mesocosms): Laboratory Pro- ject ID: RJ0614B. Unpublished study prepared by ICI Plant Pro- tection Division. 1855 p.

42275602 Farrelly, E.; Hamer, M. (1991) Fonofos/Lambda-Cyhalothrin: Acute Toxicity to First Instar Daphnia magna of a 200/4 g/kg Granular Formulation: Lab Project Number: 90JH341. Unpublished study prepared by ICI Americas, Inc. 21 p.

43908811 Kent, S.; Sankey, S.; Banner, A.; et al. (1995) Lambda-Cyhalothrin: Acute Toxicity to Daphnia magna of a 25 CS Formulation: Lab Project Number: AA0679/C: BL5235/B. Unpublished study prepared by Brixham Environmental Lab. 22 p. 

### 850.1010 Aquatic inver tebrate acute toxicity , test, freshwater daphnids

MRID Citation Reference

45447220 Machado, M. (2001) XDE-225 and Lambda-Cyhalothrin: Comparative Toxicity to Daphnids (Daphnia magna) Under Static-Renewal Conditions: Lab Project Number: 12550.6139: 011055. Unpublished study prepared by Springborn Laboratories, Inc. 76 p.103 

### 72-3 Acute Toxicity to Estuarine/Marine Organisms

MRID Citation Reference

152728 Thompson, R. (1985) PP321: Determination of the Acute Toxicity to Larvae of the Pacific Oyster (Crassos trea gigas): Study No. M258/D: No. FT 17/84: No.: BL/B/2643. Unpublished study prepared by Imperial Chemical Industries, PLC. 14 p.

152729 Thompson, R. (1985) PP321: Determination of Acute Toxicity to Mysid Shrimps (Mysidopsis bahia): Study No. M258/C: Report No. BL/B/2635. Unpublished study prepared by Imperial Chemical Industries PLC. 12 p.

152732 Hill, R.; Caunter, J.; Cumming, R. (1985) PP321: Determination of the Chronic Toxicity to Sheepshead Minnow (Cyprinodon variega- tus) Embryos and Larvae: Study No. N090B: Report No. BL/B/2677. Unpublished study prepared by Imperial Chemical Industries PLC. 35 p.

153506 Hill, R. (1985) PP321: Determinat ion of Acute Toxicity to Sheeps- head Minnow (Cyprinodon variegatus): Study No. M258/B: Report No. BL/B/2615. Unpublished study prepared by Imperial Chemical Industries PLC. 17 p. 

### 72-4 Fish Early Life Stage/ Aquatic Invertebrate Life Cycle Study

MRID Citation Reference

41217501 Farrelly, E.; Hamer, M. (1989) PP321: Daphnia magna Life-Cycle Study Using a Flow-through System: Rep t. No. RJ0764B. Unpub- lished study prepared by ICI Agrochemicals, Jealo tts Hill Re- search Station. 29 p.

41217500 ICI Agricultural Products (1989) S ubmission of Daphnia Lifecycle Study in Compliance with Registration Standard for Karate In- secticide: (10182-96). Transmittal of 1 study.

No MRID on DER Thompson, R.S. 1987 Mysid Lifecycle Study with PP321



### 72-5 Life cycle fish

MRID Citation Reference

41016101 Tapp, J.; Maddock, B.; Harland, B.; et al. (1989) Second Interim Report-- Lambdacyhalothrin (Karate PP321): Determination of Chro- nic Toxicity to Fathead Minnow (Pimephales promelas ) Full Life- cycle: Report No. BL/B/3489. Unpublished study prepared by Imperial Chemical Industries PLC. 32 p.

41519001 Tapp, J.; Maddock, B.; Harland, B. et al. (1989) Lambda-Cyhalothrin in (Karate PP321): Determination of Chronic Toxicity to Fathead minnow (Pimephales promelas) Full Lifecycle: Lab Project No.: Q600/E (FT35/87).104 Unpublished study prepared by Imperial Chemi- cal Industries PLC. 255
p.

41745501 Tapp, J. (1990) Summary of Control Data Generated During Full Lifecycle Studies with the Fathead Mi nnow Pimephales promelas ...: Lab Project Number: P171/C: Q600/E: S001/A. Unpublished study prepared by ICI Americas. 11 p.

41739801 Tapp, J.; Smith, C. (1990) ICI Re sponse to the July 26, 1990 EEB Review of the PP321 Fish Lifecycle Study: Unpublished Study prepared by ICI Group Environmental Laboratory. 14 p. 

### 72-7 Simulated or Actual Field Testing

MRID Citation Reference

40515902 Kennedy, J.; Cole, J.; Ekoniak, P. et al. (1988) USA Experimental Ponds (Mesocosms): Biological Development of the Ponds During the 3 Months following Construction, II: Laboratory Project ID: RJ0612B. Unpublished study prepared by ICI Plant Protection Division. 379 p.

41253901 Hill, I.; Cole, J.; Hadfield, S.; et al . (1989) ICI Response to EEB's Review of April 11, 1989, of the PP321 Mesocosm Study: RJ0612B: RJ0614B. Unpublished study prepared by ICI Agrochemi- cals, Jealott's Hill Research Station. 293 p.

42675703 Runnalls, J. (1992) Lambda-Cyhalothrin: Addendum to RJ0614B; Evaluation of the Impact of Run-Off and Spray-Drift on Aquatic Ecosystems, Using USA Experimental Ponds (Mesocosms); Additional Water Residue Data: Lab Project Number: PP321CF01: RJ0614B. Unpublished study prepared by ICI Agrochemicals, Jealott's Hill Research Station. 27 p. 

### 141-1 Honey bee acute contact

MRID Citation Reference

40052409 Gough, H.; Collins, I.; Everett, C.; et al. (1986) PP321: Acute Contact and Oral Toxicity to Honey Bees (Apis mellifera): Labo- ratory Project ID: RJ0390B. Unpublished study prepared by ICI Americas Inc., Jealott's Hill Research Station. 23 p. 

### 123-1 or 2 Plant Testing

152731 Thompson, R. (1985) PP321: Toxicity to the Green Alga Selenastrum capricornutum: Study No. M068/B: Re port No. BL/B/2584. Unpub- lished study prepared by Imperial Chemical Industries PLC. 17 p. 

### 141-2 Honey bee residue on foliage

MRID Citation Reference105 40436302 Gough, H.; Brown, R. (1987) PP 321: Toxicity of Residues on Foliage to Honey Bees (Apis mellifera): Laboratory Project ID RJ 0611B. Unpublished study prepared by ICI Plant Protection Div. 29 p.

40436303 Gough, H.; Collins, I.; Wilkinson, W. (1986) PP 321: Effects on Honey Bees (Apis mellifera) Foraging on Simulated Honeydew on Winter Wheat, 1985: Laboratory Project ID RH 0464B. Unpublished study prepared by ICI Plant Protection Div. 54 p.



### 128807 Gamma Cyhalothrin Eco Effects bibliography

71-1 Avian Singl e Dose Oral Toxicity

MRID Citation Reference

45447210 Medlicott, B.; Harris, T. (2000) XR-225 Technical: Avian Acute Oral Toxicity Test with Northern Bobwhite (Colinus virginianus): Lab Project Number: 000030: 00008. Unpublished study prepared by Genesis Laboratories, Inc. 43 p.

45447211 Medlicott, B.; Harris, T. (2000) XR-225 Formulation (GF-231): Avian Acute Oral Toxicity Test with Northern Bobwhite (Colinus virginianus): Lab Project Number: 000118: 00024. Unpublished study prepared by Genesis Laboratories, Inc. 42 p.



### 71-2 Avia n Dietary Toxicity

MRID Citation Reference

45447212 Medlicott, B.; Harris, T. (2000) XR -225 Technical: Avian Acute Dietary Toxicity Test with Northern Bobwhite (Colinus virginianus): Lab Project Number: 000033: 00009. Unpublished study prepared by Genesis Laboratories, Inc. 62 p.

45447213 Medlicott, B.; Harris, T. (2000) XR -225 Technical: Avian Acute Dietary Toxicity Test with the Mallard (Anas platyrhynchos): Lab Project Number: 000034: 00010. Unpublished study prepared by Genesis Laboratories, Inc. 62 p. 

### 72-1 Acute Toxicity to Freshwater Fish

MRID Citation Reference

45447214 Marino, T.; Rick, D. (2000) XR-225: An Acute Toxicity Study with the Rainbow Trout, Oncorhynchus mykiss Walbaum: Lab Project Number: 001073. Unpublished study prepared by The Dow Chemical Company.106 50 p.

45447215 Marino, T.; Rick, D. (2001) XR-225: An Acute Toxicity Study with the Bluegill Sunfish, Lepomis macrochirus Rafinesque: Lab Project Number: 001074(A). Unpublished study prepared by The Dow Chemical Company. 48 p.

45447216 Marino, T.; Rick, D. (2001) XR-2 25 and Lambda-cyhalothrin: An Acute Toxicity Comparison Study with the Bluegill Sunfish, Lepomis macrochirus Rafinesque: Lab Project Number: 001074(B). Unpublished study prepared by The Dow Chemical Company. 67 p.

45447218 Marino, T.; Rick, D.; Staley, J.; et. al. (2001) XDE-225 Insecticide: GF231 (150G/L Formulation): An Acute Toxicity Study with the Rainbow Trout, Oncorhynchus mykiss Walbaum: Lab Project Number: 001191. Unpublished study prepared by The Dow Chemical Company. 46 p.

45447217 Machado, M. (2001) XDE-225 and Lambda-cyhalothrin: Comparative Toxicity to Rainbow Trout (Oncorhynchus mykiss) under Flow-Through Conditions: Lab Project Number: 12550.6140: 011056. Unpublished study prepared by Springborn Laboratories, Inc. 76 p.



### 72-2 or 850-1010 Acute Toxicit y to Freshwater Invertebrates

MRID Citation Reference

45447219 Marino, T.; Rick, D. (2000) XDE-225: An Acute Toxicity Study with the Daphnia, Daphnia magna Straus: Lab Project Number: 001075. Unpublished study prepared by The Dow Chemical Company. 44 p.

45447221 Marino, T.; McClymont, E.; Staley, J. (2001) XDE-225 Insecticide; GF231 (150G/L Formulation): An Acute Toxicity Study with the Daphnia, Daphnia magna STRAUS: Lab Project Number: 001192. Unpublished study prepared by The Dow Chemical Company. 49 p.

45447220 Machado, M. (2001) XDE-225 and Lambda-Cyhalothrin: Comparative Toxicity to Daphnids (Daphnia magna) Under Static-Renewal Conditions: Lab Project Number: 12550.6139: 011055. Unpublished study prepared by Springborn Laboratories, Inc. 76 p.

46065601 Henry, K.; McClymont, E.; Najar, J. (2003) XDE-225: Toxicity Testing with Various Life Stages of the Amphipod, Gammarus pseudolimnaeus. Project Number: 021119. Unpublished study prepared by The Dow Chemical Co. 83 p.

46394703 Henry, K.; McClymont, E.; Najar, J. (2003) XDE-225: An Acute Toxicity Study With The Amphipod, Gammarus pseduolimnaeus. Project Number: 021059. Unpublished study prepared by The Dow Chemical Co. 39 p. 

### 72-4 Fish Early Life Stage/ Aquatic Invertebrate Life Cycle Study107 MRID Citation Reference

45447222 Kirk, H.; McClymont, E.; Staley, J .; et. al. (2001) XDE-225: Evaluation of the Chronic Toxicity with the Da phnid, Daphnia magna STRAUS: Lab Project Number: 011051. Unpublished study prepared by The Dow Chemical Company. 92 p. 

### 123-2 Aquatic plant growth

MRID Citation Reference

45447406 Kirk, H.; Gilles, M.; McClymont, E.; et. al. (2000) XR-225: Growth Inhibition Test with the Freshwater Green Alga, Selenastrum capricornutum PRINTZ: Lab Project Number: 001093. Unpublished study prepared by The Dow Chemical Company. 41 p.

45447407 Kirk, H.; Gilles, M.; McClymont, E. et al. (2001) Gf-231 Insecticide: Growth Inhibition Test with the Fr eshwater Green Algae, Selenastrum capricornutum PRINTZ: Lab Project Number: 001203. Unpublished study prepared by The Dow Chemical Company. 45 p. 

### 141-1 Honey bee acute contact

MRID Citation Reference

45447408 Hahne, R. (2000) XR-225 Technical: Acute Oral Toxicity Test with the Honeybee (Apis mellifera): Lab Project Number: 46098: 000112. Unpublished study prepared by ABC Laboratories, Inc. 21 p.

45464802 Hahne, R.; Whitaker, J. (2000) XR-225 Technical: Acute Contact Toxicity Test with the Honeybee, Apis mellifera: Lab Project Number: 46099: 000113. Unpublished study prepared by ABC Laboratories, Inc. 18 p.

45464803 Hahne, R.; Whitaker, J. (2000) XR-225 Formulation (GF-231): Acute Contact Toxicity Test with the Honeybee, Apis mellifera: Lab Project Number: 46101: 000115. Unpublished study prepared by ABC Laboratories, Inc. 17 p.

45464804 Hahne, R. (2000) XR-225 Formulation(GF-231): Acute Contact Toxicity Test with the Honeybee, Apis mellifera: Lab Project Number: 46100: 000114. Unpublished study prepared by ABC Laboratories, Inc. 21 p. 

### 141-2 Honey bee residue on foliage

MRID Citation Reference

45464805 Hahne, R. (2000) XR-225 Formulation (GF-231): Toxicity of Residues on Foliage to the Honeybee (Apis mellifera): Lab Project Number: 46102: 000116. Unpublished study prepared by ABC Laboratories, Inc. 17 p.108 Appendix A. PRD data reque st justification tables

The following proposed Data Call-in tables include rationales for requiring the data requested in this problem formulation, explanations of the util ity of the data, and explanations for how the data might impact risk assessment, follo wing the format provided by PRD.

Guideline Number: 835.2120 Study Title: Hydrolysis Rationale for Requiring the Data According to 40 CFR Part 158, Subpart N (Environmental Fate) §158.1300 (Environmental fate data requirements table), th ese data are required for all terrestrial use patterns.

At this time, there is one available study that was deemed acceptable at pH 5 and 7, conducted on gamma- cyhalothrin; however, the part conducted at pH 9 was deemed unacceptable, but upgradable. The other study wa s conducted at a rate that exceeded the solubility limit of lambda -cyhalothrin. “Experiments are performed to determine the rate of hydrolysis of the test substa nce as a function of pH and the identity or nature and rates of formation and decline of hydrolysis produc ts to which organisms may be exposed.” (From Fate, Transport and Transformati on Test Guidelines – OCSPP Guideline 835.2120.) In order to clarify the rate of react ion of the test substa nce in pH 9 buffered solutions, the registrant should submit data to upgrade the pH 9 study, or a new study should be conducted at pH 9.

Practical Utility of the Data
How will the data be used? Lambda -cyhalothrin and gamma -cyhalothrin are synthetic pyre throids with high toxicity towards aquatic organisms, including those li ving in the benthos. Knowledge of their persistence in terrestrial and aquatic environments is importa nt. The results of this study will be used in the environmental fate asse ssment, and later on, in the ecological risk characterization.

How could the data impact the Agency’s future decision-making? Without these data, the Agency would have to make certain conservative assumptions ( e.g. assume that the chemicals are stable under alkaline conditions). These conservative assumptions could lead to incorrect conclusions about the environmental fate assessment and consequently about the ecological risk characterization. Also, there would be a higher degree of uncertainty in the environm ental fate assessment. Knowledge of these dissipation pathways in detail is essential to perform a better and accurate environmental fate assessment and ecological risk assessment.

The lack of these data will limit the flexibi lity the Agency and registrants have in coming into compliance with the Endangered Species Ac t and could result in use restrictions for109 lambda -cyhalothrin and gamma -cyhalothrin that may be unnecessary.110 Guideline Number: 835.4200 Study Title: Anaerobic Soil Metabolism Rationale for Requiring the Data According to 40 CFR Part 158, Subpart N (Environmental Fate) §158.1300 (Environmental fate data requirements table), th ese data are required for all terrestrial use patterns.

The available supplemental anaerobic soil metabolism study, conducted on lambda

cyhalothrin, was performed with only one so il, for a period of only two months of anaerobic incubation, and sampli ng was insufficient to determ ine a suitable half-life. Furthermore, the pattern of anaerobic degradatio n appeared to be bipha sic, but this could not be corroborated with the limited availabl e data. A new study is required. Anaerobic studies with one soil type are generally su fficient for the evaluation of transformation pathways, but for lambda- cyhalothrin, cyclopropyl- and phenyl- or phenoxy-labeled studies are needed. Rates of transformation should be dete rmined in at least three additional soils (from Fate, Transport and Transformation Test Guidelines – OCSPP Guideline 835.4100 & 835.4200). Practical Utility of the Data
How will the data be used? Lambda -cyhalothrin and gamma -cyhalothrin are synthetic pyre throids with high toxicity towards aquatic organisms, including those li ving in the benthos. Knowledge of their persistence in terrestrial and aquatic environments is importa nt. The results of this study will be used in the environmental fate asse ssment, and later on, in the ecological risk characterization.

How could the data impact the Agency’s future decision-making? Without these data, the Agency would have to make certain conservative assumptions ( e.g. assume that the chemicals are stable under anaerobic soil metabolism conditions). These conservative assumptions could l ead to incorrect c onclusions about the environmental fate assessment and c onsequently about th e ecological risk characterization. Also, there would be a higher degree of uncertainty in the environmental fate assessment. Knowledge of these dissipation pathways in detail is essential to perform a better and accurate environmental fate assessment and ecological risk assessment.

The lack of these data will limit the flexibi lity the Agency and registrants have in coming into compliance with the Endangered Species Ac t and could result in use restrictions for lambda -cyhalothrin and gamma -cyhalothrin that may be unnecessary.111 Guideline Number: 835.4400 Study Title: Anaerobic Aquatic Metabolism Rationale for Requiring the Data According to 40 CFR Part 158, Subpart N (Environmental Fate) §158.1300 (Environmental fate data requirements table), th ese data are required for all terrestrial use patterns.

There is only one anaerobic aquatic metabo lism study (soil/ sediment system) that was conducted with [ 14 C-cyclopropyl]- or [ 14 C-phenoxy]-labeled lambda -cyhalothrin. Two studies should be conducted utilizing lambda -cyhalothrin on one sediment system of freshwater and one of estuarine/ marine orig in. According to the OCSPP Fate, Transport and Transformation Test Guidelines (835.4300 & 835.4400)...“At least two sediments and their associated waters are used for both the aerobic and the anaerobic studies respectively...However, there may be cases where more than two aquatic sediments should be used, for example, for a chemical that may be present in freshwater and/or marine environments. Sediments should be re presentative of intended use sites.” Since both lambda -cyhalothrin and gamma -cyhalothrin have the potential for use near estuarine/ marine areas, one of the required sediment systems should be from estuarine/ marine environment.

Practical Utility of the Data
How will the data be used? Lambda -cyhalothrin and gamma -cyhalothrin are synthetic pyre throids with high toxicity towards aquatic organisms, including those li ving in the benthos. Knowledge of their persistence in soil and aquatic environments is important. The results of this study will be used in the environmental fate assessm ent, and later on, in the ecological risk characterization.

In addition, the data will be used to derive th e rate of reaction input parameter to be used in the aquatic models GEN EEC2, PRZM/ EXAMS and FIRST. The results from these models are used for ecological risk estim ation and in drinking water exposure

assessments.

How could the data impact the Agency’s future decision-making? Without these data, the Agency would have to make certain conservative assumptions ( e.g. use three times the single avai lable half-life value as half-life input for the anaerobic aquatic metabolism). This conservative assumption could lead to higher predicted concentrations (EECs), according to the models , and consequently, higher risk quotients. Also, there would be a higher degree of uncerta inty in the environmental fate assessment. At this time, the anaerobic aquatic metabolism of lambda -cyhalothrin and gamma

cyhalothrin is uncertain because only one value is available. Knowledge of this dissipation pathway in detail is essential to perform a be tter and accurate environmental fate assessment and risk assessment.112 The lack of these data will limit the flexibi lity the Agency and registrants have in coming into compliance with the Endangered Species Ac t and could result in use restrictions for lambda -cyhalothrin and gamma -cyhalothrin that may be unnecessary.113 Guideline Number: None Study Title: Environmental Chemistry Methods (ECM) and Independent Laboratory Validation (ILV) for Soil, Water and Sediment Rationale for Requiring the Data According to the data requirements in 40 CFR Part 158, ECMs are currently required along with successful confirmatory method trials (validation) by an independent laboratory ( i.e. ILVs). The registrant submitted one method (MRID 40515901, published in the Agency’s ECM website), 15 that could quantify lambda -cyhalothrin in water and sediment. EFED located an Environmen tal Chemistry Method Evaluation (ECME) performed by the Analytical Chemistry Branch (ACB), of the water portion of this study (BEAD review dated 9/23/93, Environmenta l Chemistry Method Validation Report No. ECM 0004W1). The ACB determined an LOD of 10 ng/L (ppt) while the registrant’s value was 1 ppt. This method cannot be used to determine lambda -cyhalothrin’s transformation products. Furthermore, ther e is one ECM and one ILV that quantifies lambda -cyhalothrin and other pyrethroids in sediments (MRID 47053001 and 47053002). It is uncertain whether th is method can distinguish gamma -cyhalothrin from lambda

cyhalothrin. The Agency will verify th e suitability of these methods and the appropriateness of their levels of quantita tion. At this time, no methods have been identified for the analysis of gamma -cyhalothrin. In addition to the method for soil, at this time, methods are required for water and sediment. The results of previous assessments indicate that there is risk fo r freshwater and estuarine/ marine fish, invertebrates and benthic organisms. Th erefore, ECMs for water and sediment are required in addition to the ECM for soil. The ECMs should include parent and those residues found in the laborato ry studies that exceed 10% of the applied. Acceptable ECMs for the residues of concern (paren t and its transformation products, Compounds XV, Ia, Ib, V and 3-(4-hydroxyphenoxy)-benzaldehyde) should have levels of quantitation that are adequate to address risk concerns or that are at levels below the toxicological endpoints for the relevant aquatic organisms. The registrant is encouraged to submit state-of-the-art environmental chemistry methods; further, multi-residue methods (MRMs) for soil, wate r and sediment are preferred. Practical Utility of the Data
How will the data be used? The data will be used to verify the suitabili ty of the methods. Subsequently the methods could be used by states or other enforcement agencies, departments or entities, to monitor concentrations of the residues of concern. Va lidated analytical methods in environmental media ( a.k.a. , ECMs) are useful for conducting and evaluating submitted environmental fate and toxicity field and monitoring studi es and for addressing potential risks to the environment posed by the use and/or accidental release of pesticides.

How could the data impact the Agency’s future decision-making? If monitoring of the chemical is required or performed, the Agency could be able to determine if the chemical is present in th e environment at concentrations that are

15 Available at url: http://www.epa.gov/oppbead1/methods/ecmindex.htm114 Guideline Number: None Study Title: Environmental Chemistry Methods (ECM) and Independent Laboratory Validation (ILV) for Soil, Water and Sediment threatening to wildlife (or to humans, in th e case of drinking wate rs), according to the levels of concern (LOCs or DWLOCs). If th at is the case, measures to prevent these concentrations to occur could be taken. Th e data could also be used by enforcement entities like the states or government agencies or departments. Without these data, the potential for the determination of residues of lambda -cyhalothrin, gamma -cyhalothrin and transformation products ( e.g. , Compounds XV, Ia, Ib, V and 3-(4-hydroxyphenoxy)- benzaldehyde) in soil, water and sediment is restricted. The lack of these data will limit the flexibility the Agency and registrants have in coming into compliance with the Endangered Species Act, and could result in use restrictions for lambda -cyhalothrin and

gamma -cyhalothrin which may otherwise be avoi ded, or which are unnecessarily severe.115 Guideline Number: Non-guideline Study Title: Wood Leachability Rationale for Requiring the Data A study is required. It should be conducted according to the Amer ican Wood Preservers Association Standard Method of Determini ng the Leachability of Wood Preservatives (E11-06). It is suggested that the registrant provide a protocol to be evaluated by the Agency prior to performing the study. Practical Utility of the Data
How will the data be used? Lambda -cyhalothrin and gamma -cyhalothrin are synthetic pyre throids with high toxicity towards aquatic organisms, including those livi ng in the benthos. They are used for wood protection treatment to buildings/products outdo or. The results of this study will be used in the ecological risk characterization, and in particular, for aquatic assessments. At the present time, based on the binding capacity of these chemicals to soil organic carbon, and their high octanol/ water partition coefficient, the EFED believes that lambda -cyhalothrin and gamma -cyhalothrin bind strongly to the wood ma terial, but there are uncertainties as to the degree to which this occurs. Knowle dge of the leachability from treated wood for these chemicals is important.

In addition, the data will be used to derive the equivalent application ra te to be used in the aquatic models GENEEC2 and PRZM/ EXAMS. The results from these models are used for exposure assessment, ecological risk esti mation, and ultimately in risk assessment.

How could the data impact the Agency’s future decision-making? Without these data, the Agency would have to make certain conservative assumptions ( e.g. assume that 100% of the lambda -cyhalothrin and/ or gamma -cyhalothrin leaches instantaneously from the wood, to estimate the application rate in GENEEC and PRZM/ EXAMS). These conservative assumptions could lead to hi gher predicted concentrations (EECs), according to the models, and cons equently, higher risk quotients. The application rate input parameter has a major effect in the determination of the aquatic EECs. Also, there would be a higher degree of uncertainty in the overall transport assessment for ecological effects. Knowledge of the leachability from treated wood of this chemical in detail is essential to pe rform a better and accurate environmental fate/ transport and risk assessment.

The lack of these data will limit the flexibi lity the Agency and registrants have in coming into compliance with the Endangered Species Ac t and could result in use restrictions for this chemical that may be unnecessary.116 Guideline Number: None Study Title: POTW Effluent Monitoring and POTW Treatability Study Rationale for Requiring the Data POTW Effluent Monitoring – Request any existing or ongoing POTW effluent monitoring data for the pyrethroids be submitted to the Agency.

POTW Treatability Study – The Agency has recently requested and provided comments on a protocol developed by the Py rethroid Working Group (PWG) for a bench scale study of waste water treatment, to assess the percentage removed in the biosolids by the treatment, the amount that would degrad e during treatment, and the amount that would remain in the waste water. Thes e data would be used to inform removal percentages by waste water treatment, whic h is an input to the Exposure and Fate Assessment Screening Tool’s (E-FAST) down-the-drain module. The Office of Pesticide Programs will continue to confer with the Office of Water with the goal of refining our down-the-drain assessment for regist ration review. It is the responsibility of the registrant to ensure that lambda -cyhalothrin and gamma -cyhalothrin are included in the study completed by the PWG or conduct a similar study on their own (following submission of a protocol for review).

Practical Utility of the Data
How will the data be used? These data would be used to inform rem oval percentages by waste water treatment, which is an input to the E xposure and Fate Assessment Screening Tool’s (E-FAST) down-the-drain module.

How could the data impact the Agency’s future decision-making? Without these data, the Agency will have to make assumptions regarding the level of removal of lambda -cyhalothrin and gamma -cyhalothrin ( e.g. , results of modeling from the EPIWEB v.4.0 may be used). These assumptions are likely to be crude and conservative. The lack of these data will li mit the flexibility the Agency and registrants have in coming into compliance with the Enda ngered Species Act, a nd could result in use restrictions for lambda -cyhalothrin and gamma -cyhalothrin which may otherwise be avoided, or which are unnecessarily severe.

Guideline Number: 850-2100 Study Title: Passerine Acute Avian Oral Rationale for Requiring the Data Although an acute avian oral study was received for both the mallard duck ( lambda

cyhalothrin) and bobwhite quail ( gamma -cyhalothrin), the Agency updated its data requirements in 40 CFR Part 158 (October 26, 2007) to include an acute oral toxicity study for both a passerine species and either a waterfowl or an upland game species. Prior to starting117 toxicity testing, a protocol will need to be pr ovided for review. Many passerine species utilize agricultural fields, forests, re sidential areas and surrounding ar eas, and, therefore, have the potential to be exposed to pestic ides used in agricultural, forest , and residential settings. It is likely that, for most pesticide use patterns, passerines are more likely to be exposed to pesticides than upland game species and waterfow l. Passerines are smaller in size and generally have faster metabolisms than the waterfowl and upland game bird species traditionally used in avian toxicity tests which could impact their sensitivity to chemicals. Data are required for either lambda - or gamma -cyhalothrin.

Practical Utility of the Data
How will the data be used? Data from passerine toxicity studies will be used to estimate potential risks to birds associated with uses of lambda- and gamma -cyhalothrin. The data will reduce uncertainties associated with the current risk assessment for passerine sp ecies and will improve our understanding of the potential effects of lambda- and gamma -cyhalothrin.

How could the data impact the Agency’s future decision-making? Because birds significantly contribute to overa ll environmental quality, a solid understanding of the potential risks to birds, in cluding passerine species, is es sential for sound environmental management. Without acceptable data for lambda- and gamma -cyhalothrin, the Agency cannot determine the levels of these chemicals that result in effects to passerine species. If the data indicates that registered usage may pose a risk of adverse effects to non -target birds above the Agency Level of Concern, the Agency may explore decision options to miti gate this risk. The lack of these data will limit the flexibility the Agency and registrants have in coming into compliance with the Endangered Species Act, and could result in us e restrictions for lambdaand gamma -cyhalothrin which may otherwise be avoi ded, or which are u nnecessarily severe.

Guideline Number: Non-guideline Study Title: Aquatic Invertebrate Acute Toxicity ( Hyalella ) Rationale for Requiring the Data

Based on a review of the registrant-submitted studies, amphipods ( Gammarus pseudolimnaeus

, EC 50 =0.00048 μg a.i./L) are more sensitive to gamma -cyhalothrin technical than the Daphnia

magna (EC 50 =0.045 μg a.i./L) by two orders of magnitude. For lambda -cyhalothrin, the same trend is observed (EC 50 =0.0067 μg a.i./L for Gammarus pulex compared to an EC 50 =0.24 μg a.i./L for Daphnia magna based on studies with the technical product). The previously submitted amphipod study is classified as supplemental and be lieved to be an underestimation of the true toxicity of gamma -cyhalothrin technical because of rapidl y declining exposure concentration over the duration of the study. In a ddition, available information in the Agency ECOTOX database and studies in the open literature (Weston and Lydy, 2010; Solomon et al 2001) indicate that the freshwater amphipod, Hyalella azteca , is substantially more sensitive to pyrethroids than Daphnia

magna , the commonly tested freshwater invertebra te. Information on the acute toxicity of lambda - or gamma -cyhalothrin to Hyalella azteca was not identified in th is problem formulation.118 Therefore, in order to ensure that risk to sensitive aquatic invertebrates (e.g., amphipods) are appropriately quantified, additional ac ute toxicity testing of the amphipod Hyalella azteca is needed (water column exposure, not sediment-spiked)

. In addition to its high sensitivity, the freshwater amphipod, Hyalella azteca , is recommended as the test species because it is also being requested for chronic freshwater sediment toxi city testing, thereby en abling acute risk to Hyalella to be estimated via porewater exposure.

A study is requested with gamma -cyhalothrin, based on the increased sensitivity of aquatic species to gamma - compared to lambda -cyhalothrin.

Practical Utility of the Data
How will the data be used? The freshwater acute toxicity study with Hyalella would allow the Agency to analyze acutely toxic effects to one of the most sensitive species of freshwater aquatic invertebrates. The effects data would be used to determine the likelihood that acute risks can pot entially impact aquatic communities, either by direct effects on inverteb rates or by indirect effects by reducing the food source for their predators (e.g., fish). By refini ng the assessment, the Agency would be able to determine whether the mitigation imposed as part of the registration review process was appropriate due to toxicity concerns with lambda - and gamma -cyhalothrin.

How could the data impact the Agency’s future decision-making? If future risk assessments are performed without these data, the Agency would have to account for the potential increased sensitivity of Hyalella to lambda - and gamma -cyhalothrin using other means which may include using an extrapolation f actor based on sensitivity differences with other pyrethroids. Since this extrap olation factor would involve uncertainty, it is likely that a conservative factor would be applied. This ma y impinge on the Agency’s flexibility in coming into compliance with the Endangered Species Act and could result in use restrictions for which are unnecessarily severe.

Guideline Number: 850.1075 Study Title: Fish Ac ute Toxicity (freshwater) Rationale for Requiring the Data

The only available study on chronic toxicity of lambda -cyhalothrin to freshwater fish was conducted with the fathead minnow, Pimephales promelas (MRID 41519001; supplemental). The NOAEC from this study (0.031 μ g a.i./L) is only about a fact or of two less than the 96-h LC 50 of 0.078 μg a.i./L for the most acutely sensitiv e freshwater fish species (golden orfe) to lambda- cyhalothrin. Furthermore, this NOAEC is virtually identical to the 96-h LC 50 of 0.029 μg a.i./L determined for bluegill with gamma -cyhalothrin (MRID 45447215). It is therefore apparent that the fathead minnow is likely not among the most sensitive freshw ater fish species tested to lambda - or gamma -cyhalothrin. In order to estimate the ch ronic toxicity to sensitive freshwater fish species (e.g., bluegill, golden orfe), an acute -chronic ratio (ACR) will likely be needed. This ACR would be applied to the most acutely sensiti ve fish species to estimate its corresponding119 chronic sensitivity. ACRs should be determined on the same species (in this case, fathead minnow) in order to reduce uncertainty in predicte d chronic toxicity values. However, there are no submitted acute toxicity studies with fathead minnow from which to derive an ACR. Deriving an ACR based on an acutely sensitive species (e. g., bluegill) and a chronica lly insensitive species (fathead minnow) would likely grossly under estimat e chronic risk to sensitive fish species. Without this study, estimation of chronic risks to sensitive fish species will involve substantial uncertainty. Therefore, the Agency is requesting an acute toxicity test of lambda- cyhalthrin to the fathead minnow in order to a ppropriately estimate chronic toxi city to fish based on existing chronic data with fathead minnow . Fathead minnow is one of the recommended test species in the test guidelines. Practical Utility of the Data
How will the data be used? The acute toxicity study with fa thead minnow would allow the Agen cy to estimate chronic effects and risks to sensitive freshwater (and estuarine/ marine) species by facilitating the derivation of an ACR. The effects data would be used to dete rmine the likelihood that the chronic risks can potentially impact aquatic communities, either by direct effects on invertebrates or by indirect effects on fish by reducing their food sources. By refining the assessment, the Agency would be able to determine whether the mitigation imposed as part of the registration review process was appropriate due to toxi city concerns with lambda- and gamma- cyhalothrin. .

How could the data impact the Agency’s future decision-making? Without this data, future risk assessments (inclu ding those for endangered sp ecies) would have to acknowledge substantial uncerta inty in chronic risk estimation for freshwater and estuarine/marine fish, such that the Agency’s “effect determinations” for endangered fish, aquatic-phase amphibians, and endangered species fr om other taxa indirectly could be called into question. This in turn might affect the determ ination of risk mitigation measures (e.g., use restrictions in areas where enda ngered species could be exposed). The lack of these data will limit the flexibility the Agency and registrant s have in coming into compliance with the Endangered Species Act and could result in use restrictions for lambda - and gamma -cyhalothrin which are unnecessarily severe.

Guideline Numbers: 850.1075, 850.1010 and non-guideline Study Title: Freshwater Fi sh Acute Toxicity (TEP) Freshwater Aquatic Invertebrate Acute Toxicity (TEP) Whole sediment: chronic invertebrates freshwater and marine

Rationale for Requiring the Data

Because there are registered outdoor uses that ma y result in significant exposure to water bodies,

acute lambda - and gamma -cyhalothrin TEP data with the synergist PBO is requested for freshwater fish and freshwater in vertebrates. The registrations are for cattle ear tags (#773-75) or cattle pour-on treatments (#773-92, #53883-248 and #53883-270).120 A total of 4 active product registrations exist for lambda -cyhalothrin and gamma -cyhalothrin formulations with PBO:

• Lambda -cyhalothrin and PBO: # 773-75, #773-92, #53883-248

• Gamma -cyhalothrin and PBO: # 53883-270

Products with the synergist PBO are likely to cau se increased toxicity to nontarget aquatic species. Currently, no data is available to quant ify the difference in toxicity for fish or invertebrates that may be concurrently exposed to lambda - and gamma -cyhalothrin and PBO compared to the active ingredients alone. While these studies are requested for the "TEP," the registrant must submit a protocol prior to conducting these TEP studies that addresses the expected toxicity from differing c oncentration ratios of PBO and the TGAI that are likely to occur in the aquatic environment. Results from the acu te freshwater toxicity tests can be used to optimize the design of the chronic sediment toxicity test. This approach is being followed by the Agency with TEP testing of PBO and pyrethrins.

Practical Utility of the Data
How will the data be used? These data are needed for a registration revi ew decision and for an endangered species assessment, which will be conducted as part of th at decision. The data would allow the Agency to determine acute risk to fres hwater organisms from exposure to lambda - and gamma

cyhalothrin in conjunction with th e synergist PBO. The effects da ta would be used to determine the likelihood that use of lambda - and gamma -cyhalothrin and PBO can potentially impact aquatic communities, either by direct effects or by indirect effects on other organisms by reducing their food sources.

How could the data impact the Agency’s future decision-making? If future endangered species risk assessments are performed without th ese data, the Agency would have to assume that lambda - and gamma -cyhalothrin “may affect" endangered invertebrates directly (and endange red species from other taxa indirectly), and use might need to be restricted in areas where endangered species could be exposed. The lack of these data will limit the flexibility the Agency and registrant s have in coming into compliance with the Endangered Species Act and could result in use restrictions which ar e unnecessarily severe.

Guideline Number: 850.1300 Study Title: Aquatic Invert ebrate Life-Cycle (freshwater) Rationale for Requiring the Data

Previously submitted studies indicate that freshwater invertebrates are among the most chronically sensitive species to lambda - and gamma -cyhalothrin, with chronic effects expected below 1 ng/L. While two supplemental studies ha ve been submitted on the chronic toxicity of lambda -cyhalothrin to Daphnia magna (MRID 41217501, 00152733), the toxicity endpoints derived from these studies are considered highly uncertain. Specifically, the exposure concentrations used in these studies varied so much (3X to more than 10X ...?) that maximum121 and minimum values overlapped among treatments . This excessive variability in exposure concentrations within treatments brings into que stion the ability to accurately determine a chronic toxicity endpoint from these st udies (e.g., NOAEC). Other guideline de viations were also noted in these two studies (e.g., high light intensities, use of too few re plicate chambers per treatment, culling of less healthy organisms during the course of the study). Obtaining an accurate chronic NOAEC for freshwater invert ebrates (e.g., daphnids) is critical to future risk assessment since this value will likely be used to estimate chronic toxicity to other more sensitive freshwater invertebrates (e.g., amphipods) which will form the basis of the risk assessment conclusions. As substantial advances in both analytical and biol ogical test methods have occurred over the past two decades (the previously submitted studies were conducted in 1985 and 1989), it is highly likely that a repeat of these st udies would yield results that are much more scientifically defensible. Without this study, estimation of chro nic risks to sensitive freshwater invertebrates (e.g., daphnia, amphipods) will invol ve substantial uncertainty.

A study is requested with gamma -cyhalothrin, based on the increased sensitivity of aquatic species to gamma - compared to lambda -cyhalothrin. Practical Utility of the Data
How will the data be used? The aquatic invertebrate life-cy cle study would allow the Agency to analyze chronic effects, including effects on reproductive su ccess and growth, to freshwater invertebrates. The effects data would be used to determine the likelihood that the chronic risks can potentially impact aquatic communities, either by direct effects on invertebrates or by indirect effects on fish by reducing their food sources. By refining the asse ssment, the Agency would be able to determine whether the mitigation imposed as part of the reregistration process was appropriate due to toxicity concerns with lambda - and gamma -cyhalothrin.

How could the data impact the Agency’s future decision-making? Without this data, future risk assessments (inclu ding those for endangered sp ecies) would have to acknowledge substantial uncertainty in chronic risk estimation for fr eshwater invertebrates, such that the Agency’s “effect determinations” for endangered invertebrates directly (and endangered species from other taxa indirectly ) could be called into question. This in turn might affect the determination of risk mitigation measures (e.g., use restrictions in areas where endangered species could be exposed). The lack of these data will limit the flexibility the Agency and registrants have in coming into compliance with the Enda ngered Species Act and could result in use restrictions for lambda - and gamma -cyhalothrin which are unnecessarily severe.

Guideline Numbers: Non-guideline Study Title: Chronic whole sediment: Freshwater and marine invertebrates Rationale for Requiring the Data No chronic sediment toxicity tests for fres hwater or marine inve rtebrates have been submitted to satisfy the Agency’s updated data requirements for outdoor uses in 40 CFR Part 158 (October 26, 2007). For lambda - and gamma -cyhalothrin, available information indicates that benthic organism s may be exposed via run-off or spray drift applications122 used in agricultural, forest, and residential settings. Based on calculations in the most recent EFED assessment for lambda -cyhalothrin (Section 18 Emergency Exemption for the Use of Lambda -cyhalothrin in Washington on Asparagus, D379522, August 2010) (see Appendix D for modeling information), th e peak sediment porewater EECs predicted for lambda -cyhalothrin (0.00253 μg a.i./L) exceed s 0.1 of the most sensitive acute LC/EC 50 (0.00048 μg a.i./L for Gammarus pseudolimnaeus ), which satisfies one of the criteria for requiring chronic whole sediment toxicity testing under 40 CFR Part 158. This comparison is based on exposure concentrations predicted for lambda -cyhalothrin and the most sensitive toxicity information for gamma -cyhalothrin. However, the exposure would is expected to be similar for gamma -cyhalothrin based on sim ilar fate properties. Additionally, the rates proposed for asparagus (3 applications of 0.034 kg a.i./ha at 21 day intervals) were not the highest current ly registered use rates (see Section 3.2). Chronic effects were also seen in all aquati c taxa tested at leve ls as low as 0.0002 μg a.i./L (Accession #073989, mysid shrimp).

The expected half-life of lambda - and gamma -cyhalothrin in sediment (28 – 61 days for aerobic soil metabolism and 21 – 53 days for aer obic aquatic metabolism) is substantially greater than 40 CFR Part 158 cr iterion of 10 days. The potential for persistent exposure from lambda - and gamma -cyhalothrin in sediment is also indicated by open literature studies on pyrethroids (Weston et al. 2005, Amweg et al. 2006 and Ding et al . 2009).

The third set of trigger criteria for requiring chronic testing (K d > 50, or log K OW >3 or
K OC > 1000) is also met for lambda - and gamma -cyhalothrin (for lambda -cyhalothrin K d mean value is 4350, log K OW is 7, and mean K OC value 333,200; for gamma -cyhalothrin
K d mean value is 622, log K OW is 5, and K OC mean value is 59,700). The physicochemical property triggers (K d , K OW and K OC ) reflect the propensity of the chemical to partition onto the particulate or organic matter phases of sediments. Exceeding any one of the physicochemical propert y triggers listed above is sufficient for indicating the pesticide has reasonable potential for partitioning to the sediment compartment.

For sediment studies involving pyrethroids, chronic whole sediment tests on Hyalella

azteca
, Chironomus tentans , and Leptocheirus plumulosus are requested. Although both are freshwater species, Hyalella and Chironomus differ substantially in their ecological niche ( i.e. , epibenthic v. infaunal species), phy siology, and there is some evidence suggesting Hyalella is among the more sensitive invert ebrates to some pyrethroids based on water column tests (Anderson et al. 2006, Maund et al. 2002). Lambda - and gamma

cyhalothrin have the potentia l to enter estuarine/marine water bodies based on current usuage patterns that include coastal areas. Therefore, testing is also required for an estuarine/marine sediment-dwe lling invertebrate species.

A study is requested with gamma -cyhalothrin, based on the increased sensitivity of aquatic species to gamma - compared to lambda -cyhalothrin.

Practical Utility of the Data123 How will the data be used? Data from sediment toxicity studies will be used to estimate potential risks to benthic organisms associated with uses of lambda - and gamma -cyhalothrin. The data will reduce uncertainties associated with the current ri sk assessment for benthic species and will improve our understanding of the potential effects of lambda - and gamma -cyhalothrin.

How could the data impact the Agency’s future decision-making? Although there was uncertainty in estimating the effect of lambda - and gamma

cyhalothrin on benthic organisms in previous assessments, there was a potential risk associated with adverse effects identified fo r other aquatic organisms. Acceptable data for benthic organisms will reduce the uncertainty from the previous assessment If the data indicates that registered lambda - and gamma -cyhalothrin usage may pose a risk of adverse effects to non-target benthic organisms above the Agency Level of Concern, the Agency may explore decision options to mitigate this risk. The lack of these data will limit the flexibility the Agency and registrant s have in coming into compliance with the Endangered Species Act, and could result in use restrictions which may otherwise be avoided, or which are unnecessarily severe.

Guideline Numbers: 850.4150 and 850.4250 Study Title: Vegetative vigor and Seedling emergence, Tier I/ Tier II

Rationale for Requiring the Data

No acceptable toxicity data are currently available to assess the risk of lambda- and

gamma -cyhalothrin to terrestrial plants.

Since lambda- and gamma -cyhalothrin has outdoor uses, vegetative vigor and seedling emergence studies are required. These phytotoxicity data are needed to evaluate the level of pesticide exposure to non-targ et terrestrial and aquatic plan ts and to assess the impact of pesticides on endangered and threatened plants. Data are required for either lambda - or
gamma -cyhalothrin.

Practical Utility of the Data

How will the data be used? Data from terrestrial plant toxicity studies will be used to estimate potential risks to plants associated with uses of lambda- and gamma -cyhalothrin. The data will reduce uncertainties associated with the current risk assessment for terrestrial plants and will improve our understanding of the potential effects of lambda- and gamma -cyhalothrin on plants.124 How could the data impact the Agency’s future decision-making? Because plants form the basis of most ha bitats and significantly contribute to overall environmental quality, a solid unde rstanding of the potential risk s to terrestrial plants is essential for sound environmental management . Without acceptable plant growth data, the Agency cannot determine the levels of lambda- and gamma -cyhalothrin that result in effects to terrestrial plants. If the data indi cates that registered usage may pose a risk of adverse effects to non-target te rrestrial plants plants above the Agency Level of Concern, the Agency may explore decision options to mitigate this risk. The lack of these data will limit the flexibility the Agency and registrant s have in coming into compliance with the Endangered Species Act, and could result in use restrictions for lambda- and gamma

cyhalothrin which may otherwise be avoi ded, or which are u nnecessarily severe.

Guideline Number: 850.4400 Study Title: Aquatic Vascular Plant Growth- Lemna spp. Tiers I/II

Rationale for Requiring the Data

No acceptable studies for lambda- or gamma -cyhalothrin have been submitted for vascular aquatic plants. The Agency has finalized its upda te to the data requirements in 40 CFR Part 158. In these updated data requirements, which were promulgated on October 26, 2007, vascular plant testing is required for pesticides with outdoor uses such as lambda- and gamma

cyhalothrin. Data are required for either lambda - or gamma -cyhalothrin.

Practical Utility of the Data125 How will the data be used? Data from aquatic plant toxicity studies will be used to estim ate potential risks to plants associated with uses of lambda- and gamma -cyhalothrin. The data will reduce uncertainties associated with the current risk assessme nt for aquatic plants and will improve our understanding of the pot ential effects on vascular aquatic plants.

How could the data change the Agency’s d ecision, or impact the Agency’s future decision-making? Because plants form the basis of most ha bitats and significantly contribute to overall environmental quality, a solid unders tanding of the potential risks to aquatic plants is essential for sound environmental management. Without plant growth data for lambda- and gamma

cyhalothrin, the Agency cannot determine the leve ls that may result in effects to vascular aquatic plants. If the data indicates that registered lambda- and gamma -cyhalothrin usage may pose a risk of adverse effects to non-target aqua tic vascular plants above the Agency Level of Concern, the Agency may explore decision options to mitigate this risk.

If future endangered species risk assessments are performed without th ese data, the Agency would have to assume that lambda- and gamma -cyhalothrin "may affect" endangered plants and use might need to be restricted in areas where endangered species could be exposed. The lack of these data will limit the flexibility the Agency and registrants have in coming into compliance with the Endangered Species Act and c ould result in use rest rictions that may be unnecessarily severe.126 Appendix B: Aquatic Ecological Effects Data

Fish Toxicity

Table B-1. Acute Toxic Effects of Lambda cyhalothrin and Gamma cyhalothrin (shaded) to Freshwater and Estuarine Fish

Species Study Guideline % A.I. Toxicity Endpoint (95 % Confidence Interval) μ g a.i. /L Toxicity Classification Study Classification MRID #

Freshwater Fish

Bluegill Sunfish (Lepomis macrochirus) 72-1a 98 LC 50 96 hr : 0.210 (0.16- 0.31) NOAEC : 0.16 (mortality) very highly toxic Core 00151598

Bluegill Sunfish (Lepomis macrochirus) 72-1b 12.9 LC 50 96 hr : 2.2 (1.9-2.7) NOAEC : 0.77 very highly toxic Core 00151601

Bluegill Sunfish (Lepomis macrochirus) 72-1b 24 LC 50 96 hr : 1.2 (1.0-1.5) NOAEC :0.46 very highly toxic Core 43908812

Bluegill Sunfish (Lepomis macrochirus) 72-1b 100 LC 50 96 hr: 0.051 (0.039- 0.066) NOAEC : <0.013 (mortality and sublethal) very highly toxic Supplemental 45447216

Bluegill Sunfish (Lepomis macrochirus) 72-1b 100 LC 50 96 hr: 0.029 (0.021- 0.039) NOAEC : 0.02 (mortality) NOAEC : 0.0077 (sublethal effects) very highly toxic Supplemental 45447215

Rainbow Trout (Oncorhynchus mykiss) 72-1c 98 LC 50 96 hr : 0.240 (0.20- 0.29) NOAEC : 0.11 (mortality) very highly toxic Core 00151597

Rainbow Trout (Salmo gairdneri) 72-1d 12.9 LC 50 96 hr : 3.4 NOAEC : N/A very highly toxic Core 00151600

Rainbow Trout (Oncorhynchus mykiss) 72-1c 24 LC 50 96 hr : 2.7 (2.3-3.1) NOAEC :1.3 (mortality) very highly toxic Core 43908813

Rainbow Trout (Oncorhynchus mykiss) 72-1c 100 LC 50 96 hr: 0.19 (0.16- 0.22) NOAEC : 0.031 (sublethal effects) very highly toxic Supplemental 45447217

Rainbow Trout (Salmo gairdneri) 72-1d 100 LC 50 96 hr: 0.072 (0.057- 0.091) NOAEC: <0.0093 (mortality and sublethal effects) very highly toxic Supplemental 45447214127 Table B-1. Acute Toxic Effects of Lambda cyhalothrin and Gamma cyhalothrin (shaded) to Freshwater and Estuarine Fish

Rainbow Trout (Oncorhynchus mykiss) 72-1c 14.7 LC 50 96 hr: 1.10 (0.86- 1.89) NOAEC: 0.28 (mortality and sublethal effects) very highly toxic Core 45447218

Golden orfe ( Leuciscus idus ) 72-1d 87.7 LC 50 96 hr : 0.078 (0.055- 0.11) NOAEC :0.055 (mortality) very highly toxic Supplemental 00153506

Estuarine/Marine Fish

Sheepshead Minnow ( Cyprinodon variegatus ) 72-3a 96.5 LC 50 96 hr : 0.807 (0.672- 0.967)
NOAEC : ≥ 0.29 (mortality) very highly toxic Core 00153506

Table B-2. Chronic T oxicity Effects of Lambda cyhalothrin to Fish

Species Study Guideline % A.I. Toxicity Endpoint (95% Confidence Interval)

μ g a.i. /L Study Classification MRID #

Freshwater Fish

Fathead Minnow ( Pimephales promelas ) 72-5 96.7 NOAEC: 0.031 LOAEC: 0.062 (adult growth; young survival and growth) Supplemental 41519001

Estuarine/Marine Fish

Sheepshead Minnow ( Cyprinodon variegatus ) 72-4a 96.6 NOAEC: 0.25 LOAEC: 0.38 (weight of the survival) Core 00153506

Aquatic Invertebrate Toxicity

Table B-3. Acute Toxic Effects of Lambda -cyhalothrin (non-shaded) and Gamma cyhalothrin (shaded) to Aquatic Invertebrates

Species Study Guideline % A.I. Toxicity Endpoint (95% Confidence Interval) μ g a.i. /L Acute Toxicity Classification Study Classification MRID #

Freshwater Invertebrates

Daphnia magna 72-2a 96.5 EC 50 48 hr :0.23 (0.18-0.29) NOAEC : 0.04 very highly toxic Core 00151599

Daphnia magna 72-2 5.5 EC 50 48 hr : 0.04 (0.03-0.06) NOAEC: Not established very highly toxic Supplemental 00151602

Daphnia magna 72-2 12.9 EC 50 48 hr : 0.065 (0.04-0.11) very highly toxic Supplemental 00151602128 Table B-3. Acute Toxic Effects of Lambda -cyhalothrin (non-shaded) and Gamma cyhalothrin (shaded) to Aquatic Invertebrates

NOAEC: Not established

Daphnia magna 72-2 24 EC 50 48 hr : 0.18 (0.14-0.23) NOAEC : 0.03 (immobility) very highly toxic Core 43908811

Daphnia magna 72-2 100 EC 50 48 hr : 0.045 (0.020-0.079) NOAEC: <0.015 very highly toxic Core 45447220

Daphnia magna 72-2 100 EC 50 48 hr : 0.095 (0.078-0.114) NOAEC: <0.0263 very highly toxic Supplemental 45447219

Daphnia magna 72-2 14.7 EC 50 48 hr : 0.154 (0.099-0.310) NOAEC: <0.011 very highly toxic Supplemental 45447221

Gammarus pulex 72-2a 94 EC 50 96 hr : 0.007 (0.005-0.009) NOAEC : 0.0005 (mortality) very highly toxic Supplemental 00152730

Gammarus pseudolimnaeus 72-2a 99.2 LC 50 :
0.00048 (neonate), 0.00385 (juvenile), 0.00812 (adult) very highly toxic Supplemental 46065601

Estuarine/Marine Invertebrates

Eastern Oyster ( Crassostrea gigas ) Mollusk Shell Deposition 72-3b 96.5 LC 50 48 hr : >590 NOAEC : 590 (immobility) highly toxic Core 00152728

Mysid Shrimp ( Mysidopsis bahia ) 72-3c >97 LC 50 96 hr : 0.0041 (0.004-0.006) NOAEC :Not established very highly toxic Core 00152729129 Table B-4. Chronic Toxic Effects of Lambda -cyhalothrin to Aquatic Invertebrates

Species Study Guideline % A.I. Toxicity Endpoint (95% Confidence Interval)

μ g a.i. /L Study Classification MRID #

Freshwater Invertebrates

Daphnia magna 72-4b 92.8 NOAEC: 0.004 LOAEC:0.005 Number of young/female Supplemental 00152733

Daphnia magna 72-4b 96.6 NOAEC: 0.002 LOAEC: 0.0035 Number of young/female, Total young Supplemental 41217501

Estuarine/Marine Invertebrates

Mysid 72-4b 98.5 NOAEC: 0.0002 LOAEC: 0.0005 Number of young per reproductive day and Number of young/treatment Core MRID (not available) Accession Number 073989

Aquatic Plant Toxicity

Table B-5. Acute Toxic Effects of Lambda -cyhalothrin (non-shaded) and Gamma cyhalothrin (shaded) to Aquatic Plants

Species Study Guideline % A.I. Toxicity Endpoint

μ g a.i. /L Study Classification MRID #

Freshwater Non-vascular Plants

Green Algae Selenastrum capricornutum 123-2 96.5 EC 50 96 hr :>310
NOAEC : ≥ 310 Supplemental 152731

Green Algae Selenastrum capricornutum 123-2 100 EC 50 96 hr :>2850
NOAEC : <1340 Supplemental 45447406

Green Algae Selenastrum capricornutum 123-2 14.7 Cell density
EC 50 72 hr: 15000 NOAEC: 5480 Growth rate
EC 50 72 hr:41300 NOAEC: 5480 Area under curve
EC 50 72 hr:16100 NOAEC: N.R. Supplemental 45447407Appendix C. Open Literature Information

The following is a cursory search of the available literature on lambda -cyhalothrin, gamma

cyhalothrin and synthetic pyrethroi ds in general, mostly about th eir prevalence/ occurrence, and about their toxicity to aquatic i nvertebrates and sediment dwelling organisms. It is not intended to be exhaustive. In the rela tively recent past there has been an increased awareness of the prevalence and toxicity of lambda -cyhalothrin, gamma -cyhalothrin, and other synthetic pyrethroids, in sediment environmen ts of urban and agricu ltural sites, particularly in California.

Ureda 2004 determined the LC 50 s for deltamethrin, lambda -cyhalothrin and cyfluthrin, in sediments, using the test species Hyalella azteca . Also, sediment samples from two locations in Central Valley, California were tested. They fo und that there was a linear relationship between the LC 50 and the total organic carbon for cy fluthrin. They found that for lambda -cyhalothrin, the LC 50 s ranged from 0.20 to 0.46 μ g/g OC

. Lambda -cyhalothrin appeared to be the most toxic of the three pyrethroids. The LOEC for lambda -cyhalothrin were of around 0.23 μ g/g OC . In addition, Amweg, et al. , 2005 determined the toxicity of six pyr ethroids in three Central Valley, CA sediments towards Hyalella azteca . They found that of all the synthetic pyrethroids tested, bifenthrin exhibited the highest toxicity, while lambda -cyhalothrin was the chemical with the next highest toxicity with the average sediment 10-day median LC 50 of 0.45 μg/g OC , which is of the same order of magnitude to Ureda 2004.

Two major factors affect the toxi city of the pyrethroids: the pres ence of a synergist, such as piperonyl butoxide (PBO) and th e temperature. The dissolved organic matter (DOM) appears to have an effect on the bioavailability of certain pyrethroids. Amweg et al. 2006a documented the effect of PBO on the pyrethroid permethrin’s toxicity towards Hyalella azteca in sediment samples. It was found that PBO could increase the toxicity of permethrin in sediment up to seven-fold. Also, Amweg and Weston 2007, documen ted the effects of the presence of PBO in sediments containing the synthetic pyrethroid bi fenthrin and other repr esentative chemicals, which included cadmium (a metal), chlorpyrifos (an organophosphate), DDT (an organochlorine), and flouranthene (a polycyclic aromatic hydrocar bon). The presence of PBO was considered as a Toxicity Identification Evaluation (TIE) tool. The bifenthrin 10-day Hyalella azteca LC 50 was 0.26 μg/g OC , compared to 0.12 μg/g OC in the presence of PBO in the overlying water at 25 μg/L (increas ed toxicity by a factor of 2.2) . For the other chemicals, the factor was around or less than 1 with no statistical difference in toxicity for all but chlorpyrifos. Eight field collected sediments, containing a va riety of synthetic pyret hroids, or synthetic pyrethroids and chlorpyrifos (except for one sedi ment that contained only chlorpyrifos), that were previously tested and found to be toxic to Hyalella azteca , were examined with and without the presence of PBO. All the sediments exhib ited higher toxicity in th e presence of PBO except for the sediment that cont ained only chlorpyrifos.

The effect of temperature was documented by Weston et al. , 2009a. In an effort to identify factors affecting the toxicity identification evaluation (TIE) of the synthetic pyrethroids (“manipulating a sample in a manner that alters th e toxicity of some toxi cants but not others”), they performed sediment toxicity tests at va rious temperatures (13, 18, 23 and 28oC). 10-day LC 50 ’s to Hyalella azteca were determined fo r four pyrethroids ( lambda -cyhalothrin, permethrin, bifenthrin and esfenvalerate), also for ch lorpyrifos, cadmium and DDT (which were

130representative of other classes of chemical s). For the four pyrethroids, the toxicity approximately doubled when the temperature was decreased from 23 to 18oC, and approximately tripled when the temperature was further decreased to 13oC. The results at 28oC were mixed, but for some of the control samples, survival was low, which could indicate th at the test species was not tolerant of the change to high temperature. For DDT, there was a similar response profile with temperature, but not as pr onounced as for the synthetic pyreth roids. For chlorpyrifos and cadmium, the responses with temperature were n early independent of temperature, and opposite to the one for the pyrethr oids, respectively. For lambda -cyhalothrin, at the standard temperature of 23oC, the 10-day Hyalella azteca LC 50 was found to be 0.42 μ g/g OC and it was found to be the most toxic of all the pyrethroid s analyzed. Various field samp les with known amounts of seven pyrethroids (some of which included lambda -cyhalothrin) and chlorpyrif os, also showed similar responses to those of the tested pyrethroids (as indicated above), with a few exceptions. The authors discussed the possible re percussions of the temperatur e dependence of the synthetic pyrethroids during the wi nter season, when the temperatures of the waters and sediments are lower.

Other TIE tools were explored by Wheelock et al . (2004). They described the uses of a pyrethroid selective antibody (an antibody synthetized in their laboratory thatselectively binds to permethrin and to a lesser degree to cypermethr in), PBO and carboxyl este rase (an enzyme that degrades pyrethroids) as TIE for pyrethroids. It was i ndicated that PBO blocks the toxicity of the OPs, while synergizes the synthetic pyrethr oids, which could confound results of samples of unknown composition, containing both types of compounds. Six pyrethroids, including lambda

cyhalothrin were explor ed in the study and Cerodaphnia dubia was the test organism. It was found that the antibody reduced the toxicity of cypermethrin samples towards C. dubia , but that the antibody controls presented some toxi city towards the species. PBO at 100 μ g/L synergized the pyrethroids by factors ra nging from 9- to 137-fold. Lambda -cyhalothrin presented a toxicity ratio of 40-fold. In the presence of esterase, mo rtality was removed for all the pyrethroids tested, but not for diazinon and chlorpyrifos. The authors indicate that esterase could be a promising TIE tool for synthetic pyrethroids. It is noted that the esterase activity (hydrolysis rate) for lambda -cyhalothrin could not be measured unde r the testing conditions. In 2006, Wheelock et al . published an article on the use of carboxyl esterase in TIE using both C. dubia and H. azteca in a variety of water samples (activity was show n also in municipal effluents and seawater), showing the usefulness of this enzyme in TIE. The pyrethroids used in this latter study were permethrin and bifenthrin.

Weston and Jackson (2009) also evaluated enzime s as toxicity identification evaluation (TIE) tools for pyrethroids and orga nophosphates in water and sediment . The carboxylesterase from Lucilia cuprina (E3) was able to reduce th e toxicity of three pyrethroids towards Hyalella azteca in water 12-70-fold for three repres entative pyrethroids (not including lambda - or gamma

cyhalothrin). In sediments, a re duction of only 2-fold was achieve d in toxicity of pyrethroids. On the other hand, the phosphotriesterase from Agrobacterium radiobacter (OpdA) achieved at least a reduction of 35-fold in toxicity towards chlorpyrifos, an organophosphate insecticide. The authors indicated that fo r pyrethroids, which are str ongly hydrophobic, exposure towards H.

azteca through interstitial water may be important , but that the E3 enzime may not diffuse effectively into sediments (to reduce the toxicity).

131In 2008, Xu et al. published a report about th e desorption kinetics of pyret hroids in sediments. They observed that aging sediments may have a marked effect on the desorption rates of pyrethroids in sediments. Two spiked sedime nts and two field samples containing pyrethroids were aged for various periods of time through 200 days. For the spiked sediments, four representative pyrethroids were used (including lambda -cyhalothrin). Their observation was that the fraction of the pyrethroi ds that desorbs quickly ( F rapid ) decreases with time rapidly, while the fraction that desorbs very slowly increases with time. For all the pyrethroids tested, the halflives for F rapid were two months or less. This was the coupled result of the degradation. The
F

rapid was considered the potentially bioa vailable fraction of the pyrethroids.

Using solid phase microextra ction (SPME) technique, Liu et al . (2004) achieved low levels of detection for two representative pyrethroids (b ifenthrin and permethrin) in runoff and stream waters. They found that in stream waters, th e freely dissolved pyrethroid concentrations contributed to only 0.4 to 1.0% of the overall co ncentration, while in the runoff waters, it was 10 to 27%. Partitioning was dominated by the adsorption to suspended solids, followed by dissolved organic matter (DOM). Concentr ation determination following liquid-liquid partitioning of the water samples overestimated the concentrations, compared to the SPME sampling followed by GC analysis even after fi ltration of the samples or centrifugation. The authors suggested that a better understanding of water quality coul d be achieved using the SPME sampling for pyrethroids.

The Hunter et al. team (2009) us ed solid phase microextraction (SPME) to meas ure pyrethroids in sediment pore water. They used disposable polydimethylsiloxane fi bers to detect seven pyrethroids (not including lambda - or gamma -cyhalothrin). They observed that the fibersediment partition equilibrium was reached in less than 5 days when the samples were agitated at low speed, but more than 23 days without agitatio n. SPME applied to field samples was able to detect pore-water concentrations as low as 0.1 ng/L. Three sediments were used in method development, and two urban runoff sediments we re also tested. The authors pondered on the advantages and disadvantages of agitation to measure pyrethroi ds. They indicated that the matrix-SPME method is “simple, inexpensive, and relatively fast...a s well as sensitive.”

In an early study, it was found that lambda -cyhalothrin adsorbed to suspended matter with organic coatings with variab le sorptive capacities (Zhou et al . 1995). They observed that both the quantity and the character of the organic matter are important in describing the distribution of lambda -cyhalothrin. Adsorption was low on minera l particles (without or ganic coatings) and followed the order montmorillonite > aluminum oxide > kaolinite. The adsorption to clay minerals with variable levels of organic material was greater. The increa se was directly related to the fraction of organic carbon (ƒ oc ). The K OC s varied with the composition of the organic coating. The highest K OC s were observed for coatings with the highest levels of aromatic material. The K OC s decreased with increasing pola rity of the organic material.

In another study, Yang et al . (2006) used SPME to determine the freely dissolved pyrethroid concentrations of four pyrethroids (that did not include lambda -cyhalothrin or gamma

cyhalothrin) in waters contai ning low levels of suspended solids (SS). As the SS levels increased, the acute toxicity of the pyrethroids decreased. The highest level of SS was 200 mg/L

132which was indicated to be similar to what w ould be observed in storm runoff and irrigation runoff. Four types of sedime nts were used in this study.

Smith and Lizotte Jr. (2007) used waters from 12 ponds and lakes from Mississippi and assessed the influences of dissolved organic car bon, turbidity, suspended solids and phytoplankton (measured as chlorophyll a) on the acute toxicity of lambda -cyhalothrin and gamma -cyhalothrin towards Hyalella azteca . It was observed that the recoveries of these chemicals were relatively low which may have been due to the holding period of 24 hours allowed for stabilization of the solutions. The 48-hour immobilization EC 50 values varied by around one order of magnitude “ranged from 1.4 to 15.7 ng/L and 0.6 to 13.4 ng/L for lambda -cyhalothrin and gamma

cyhalothrin, respectively”). Gamma -cyhalothrin was found to be around 1.9 times more toxic to H. azteca than lambda -cyhalothrin. For both compounds, significant linear relationships were observed between the EC 50 s and suspended solids, turbidity, DOC and chlorophyll a. It was indicated that due to regional c limate conditions, turbidity and su spended solids were associated with phytoplankton density in the study.

Yang et al. 2007 observed the effect of dissolved organi c matter (DOM) on the bioavailability of the pyrethroids cyfluthrin and perm ethrin, and their toxicity towards Daphnia magna and Ceriodaphnia dubia . A total of 15 surface water samples from southern California were utilized. The dissolved organic conten t (DOC) ranged from 3.3-20.2% a nd the pH ranged from 6.67-7.76. Various indicators were also char acterized in the waters like an indicator of the level of aromaticity, the carboxyl group capacity and the phenol group capacity. The authors also estimated bioconcentration factors (BCFs) for D. magna . Using polydimethylsiloxane (PDMS) activated fiber, a measure of the freely dissolv ed pesticide concentration was obtained (the PDMS fibers were placed in scintillation vial s and measured via LSC). Based on their low absortivity at 254 nm, it was suggested that th e water samples had low DOM aromaticity. The E4/E6 (a ratio of absorbance at two specified wavelengths) of <5 suggested humic acid dominated composition and lesser fulvic acids. Finally, the molar content of carboxylic acid and phenolic acid, normalized for DOC varied widely. The DOM did not affect the freely available permethrin, but for cyfluthrin, the freely available cyfluthrin was lower in the natural waters than for the control samples in all instances. The K DOC s were less for cyfluthrin than for permethrin by about twice, suggesting affinity of cyfluthrin towards the DOM.
K DOC = (C
w – C free ) / (DOC x C free ) The cyfluthrin D. magna body residues were lower in natural wa ters than in the control in 14 of the 15 samples (for 9 samples, the difference was significant). There was a significant correlation between the cyfl uthrin body residue and C free , but not for permethrin. In 96-hour static exposure tests with C. dubia neonates, the cyfluthrin LC 50 s were greater than the controls in every case (for 7 samples, the difference was significant). These finding s suggest high affinity of cyfluthrin with organic carbon and organic matte r, and lower bioavailabili ty in natural waters than in control waters. However, for permethri n, the DOM appeared to ha ve little effect on the bioavailability and toxicity.

In a recent study (Stout II, et al. 2009), conducted by the US Department of Housing and Urban Development, in collaboration with the Agency, several chemicals were surveyed on floors of occupied homes. The survey include d several synthetic pyrethroids like lambda -cyhalothrin. The most frequently detected pesticide was permethrin (89% of the samples). Piperonyl

133butoxide was also commonly observed (52% of the samples). Lambda -cyhalothrin was detected with a frequency of 21% (n = 467 samples; m ean not reported for chemicals with detection frequency below 30%; maximum value = 61 ng/cm 2 ), illustrating that this chemical is commonly applied, detected and present in homes.

Lambda -cyhalothrin is among the constituents monitored by the National Water Quality Assessment (NAWQA), maintained by the U.S. Geol ogical Survey. One kind of parameter (type of samples) is reported: “ lambda -Cyhalothrin_ water_ filtered_ recoverable_ micrograms per liter,” with a reported percent of samples with this parameter of 7.4 (report units of μ g/L).

Multiple articles from the literature document the presence of synthetic pyrethroids, like lambda

cyhalothrin and gamma -cyhalothrin, in both urban and agricultural sediments. Weston et al. 2005, studied the presence of synthetic pyrethroids in Roseville, CA, selected as a typical suburban development. Sediments from creeks th at drain subdivisions of single-family homes were found to be toxic to Hyalella azteca . The sediments were tested for several pesticides, as well as 7 pyrethroids, including lambda -cyhalothrin. Bifenthrin was present in all the sediment samples. It was considered to be the primary cause of the toxicity towards the organism, with additional significant contributions of the pyret hroids cyfluthrin and cypermethrin. The maximum concentration of lambda -cyhalothrin was found to be 13 ng/g dry weight, for the tributary 13, Kaseberg Creek sample. It was de tected in 16 out of 24 sediment samples. The authors indicate that the presence of synthetic pyrethroids was not likely to be due to agricultural uses. In Placer County, the use of synthetic pyret hroids for agricultural pu rposes was reported to amount to around 1%.

Amweg et al. 2006b also studied synthetic pyrethroids in urban areas of California and Tennessee. Bifenthrin was found to be the majo r contributor to the t oxicity of sediments sampled in California to Hyalella azteca , due to its high reported con centrations and toxicity. Cypermethrin, cyfluthrin, deltamethrin and lambda -cyhalothrin may have contributed to the toxicity in some of the sites. The concentratio ns of cypermethrin and cyfluthrin were typically higher than for other synthetic py rethroids (usually 2-30 ng/g), but the bifenthrin and permethrin concentrations were the highest. On the othe r hand, in Tennessee only a few samples contained synthetic pyrethroids and none of the samples were toxic to Hyalella azteca . The differences between the two sites were attributed to different climate, types of residential development and pesticide use practices.

Holmes et al. 2008 presented the occurrence and toxicity of the synthetic pyrethroids throughout the state of California’s urban cr eek sediment samples. First, 90 samples were screened for toxicity to Hyalella azteca , of which around one third caused signi ficant toxicity to the organism. Later, 30 sample locations were selected for the final study. Of the 30 samples, 25 were toxic to Hyalella azteca at 23oC and all 30 samples were toxic at 15oC (the synthetic pyrethroids often show higher toxicity at lower temperatures, as in dicated above). Seven of eight pyrethroids were detected in the sediment samples. Fenpropathri n was not detected in any of the samples, and deltamethrin and esfenvalerate were detected infre quently; but bifenthrin was present in all the 30 samples (2.19 to 219 ng/g dry weight). Permethr in was the second most detected pyrethroid and lambda -cyhalothrin was detected in 10 samples a nd it was observed in most regions. The results suggested an important role of the synt hetic pyrethroids in Ca lifornia’s urban creeks sediment toxicity. Bifenthrin accounted for around two thirds of the toxicity on an average basis,

134with cyfluthrin and cypermethrin also playing an important role in the pyrethroid toxicity statewide.

Trimble et al. 2009 screened a previously referenced database of 24 pesticides and 94 urban sediment samples, with minimal agricultural or industrial contribution, collected from creeks and streams throughout central and north ern California. The seven synt hetic pyrethroids tested and chlorpyrifos were the pesticides most comm only occurring in toxico logically significant mixtures. Bifenthrin, permethrin and DDT were observed in greater than 90% of the samples. After normalizing the chemical con centrations for organic carbon “t o provide better estimates of the biologically available chemical fractions,” all the seven pyrethroids monitored had levels exceeding the established level of interest, LO I (defined as 0.005 toxic units, 0.005 TU) for at least one sample. Lambda -cyhalothrin was detected in around 65% of the samples (Fig. 1 of the report) and it exceeded the LOI in around 65% of the samples (apparently in all the samples). The chemical exceeded 0.5 TU in greater th an 5% of the samples (Fig. 1, and p. 1690). Bifenthrin, cypermethrin and cyfluthrin exceeded 0.5 TU (100x the initially established LOI) in greater than 30% of the samples. It was stated that... “The three pestic ides with the highest average TU values were bifenthrin (2.4 TU), cypermethrin (1.2 TU ), and cyfluthrin (0.5 TU).” These are just a few examples that illustrate the high use of syntheti c pyrethroids in urban settings and potential ecological ramifications . The concentration addition model (CA) was found to adequately predict the to xicity of pyrethroid mixtures; how ever, it was stated that there is the potential for mixtures to deviate from addi tivity. Furthermore, thei r results indicated that there is no substantial synergis tic or antagonistic effect to H. azteca from exposures to mixtures of pyrethroids.

Budd et al. 2007 sampled sediments in mixed land (urb an and agricultural) in the San Diego Creek in Newport Bay Watershed in southern Ca lifornia. Bifenthrin and fenpropathrin were among the most frequently detected synthetic py rethroids, with bifenthrin found in 95-100% of the samples. Lambda -cyhalothrin was observed less frequen tly, at a highest concentration of
2.51 μ g/kg. The highest concentrations were associat ed with commercial nurseries. The authors found in this case that the con centration of synthetic pyreth roids was generally lower in residential or commercial areas as opposed to agricultural sites. They observed that the sediments from the wet season had “a more diverse profile of detections,” as compared to the dry season sediment samples. Also, the frequency of detections of pyrethroids was higher during the wet season ( e.g. , for lambda -cyhalothrin 56% vs. 16%), but th e total concentration was not statistically different between the wet and dr y seasons. In the study, the SPME methodology was utilized to determine the free concentration of the pyrethroids in the pore water. With the exception of bifenthrin, other pyret hroids were not detected fre quently. Based on results of a poor correlation of the organic carbon normalized concentration in the sediment against the C free , for bifenthrin, it was suggested that SPME methods would be a better alte rnative to monitor for pyrethroids in sediments instead of the whole sediment analysis.

Weston et al. 2004 studied the presence of 26 pesticid es, including five pyrethroids, in 70 sediment samples taken from the agriculture domin ated Central Valley inCalifornia. Ten-day sediment tests were conducted for Hyalella azteca and Chironomus dilutus (formerly known as Chironomus tentans ), for some of the samples. Syntheti c pyrethroids were found in 75% of the sediment samples; also they were found, based on a toxicity unit basis, to be sufficiently high to

135cause toxicity in 40% of the samples toxic to C. dilutus and around 70% of the samples toxic to H. azteca . The most commonly found pyr ethroids were permethrin > esfenvalerate > bifenthrin

> lambda -cyhalothrin. The presence of several synthetic pyrethroids i llustrated the pos sibility of high levels of several synthetic pyr ethroids in agricultural zones.

In a study, Gan et al. 2005 monitored the spatia l distribution and enrichment (as measured by the enrichment ratio, ER, or ratio of the concentratio n of a substance in eroded sediment to that of the source matrix) of the synt hetic pyrethroids permethrin a nd bifenthrin, along a 260 meters runoff path. A sedimentation pond was used as the source poin t for the study (permethrin and bifenthrin had been used extensivel y at the site, for ant control, in a nursery environment). It was observed that, in general, the sediment concentrat ion of permethrin and bifenthrin increased with distance (downstream from the source). Using the source as the reference value, ERs were calculated for these chemicals. The ERs r eached 25.7-32.2 for bifenthrin at 145 m and beyond, and they were lower for permethrin. Also, the persistence of the test substances was assessed, both, in aerobic and anaerobic environments. Desp ite the fact that this study was not conducted with lambda -cyhalothrin or gamma -cyhalothrin, this study illust rated the possibility of enrichment through a runoff path for the synthetic pyrethroids. Both ch emicals have very high
K OC values and are very highly hydrophobic.

Woudneh & Oros 2006 presented a multi-chemical an alytical method that included among others lambda -cyhalothrin (it appears that the method could separate isomers A from isomers B) and piperonyl butoxide (PBO). Anal ysis of the San Francisco Bay tr ibutary sediment samples (six samples from five sites) revealed that lambda -cyhalothrin was detected in four of the sediments, at a maximum of 1.71 ng/g and was less than the detection limit in the other two samples. PBO was detected in all the samples at 0.010-0.215 ng/g.

Most of the studies related to the synthetic pyrethroi ds were conducted in California, but other studies document the presence of synthetic pyrethroids elsewhere.

Hintzen et al. 2009 monitored for 12 insecticides and de gradation products, including synthetic pyrethroids and fipronyl in Texa s stream sediments from urban sites in 2006, as a model to evaluate their potential impact in Southern US. Bifenthrin was the pyrethroid found with the highest frequency. Lambda-cyhalothrin and perm ethrin were also frequently detected; the detections of lambda-cyhalothrin occurred frequently at concentrations of concern, but the concentrations of permethrin were below the LC 50 for H. azteca . Bifenthrin was the greater contributor to the TUs, followed by lambda -cyhalothrin. Lambda -cyhalothrin’s frequency of detection was 56.9% (mean = 0.50 μ g/g OC ; maximum = 1.7 μ g/g OC ; compared to the 10-day LC 50 to Hyalella azteca of 0.45 μ g/g OC ). The TUs generally correlated well with the toxicity of the samples, although some discrepancies between th e TUs and toxicity were noted (even after normalization for organic carbon). There we re no seasonal variations of the TUs.

Ding et al. 2010 conducted monitoring for 29 pesticides , including pyrethroids like bifenthrin, fenpropathrin and lambda -cyhalothrin, from both urban and ag ricultural sites in central and southern counties in the state of Illinois in 2008. Most of the urban samples were from constructed storm drains, while the agricultural samples were from small waterways between farmlands in areas where mostly corn and soybe ans were grown and the major pesticides used

136were tefluthrin and atrazi ne. Furthermore, sedimenttoxicity tests towards Hyalella azteca were performed. In the urban samples, the synthetic pyre throids were detected in 95% of the samples. Bifenthrin was detected in 80% of the samples, while permethrin, lambda -cyhalothrin and fenpropathrin were also frequently detected. Lambda -cyhalothrin was detected in 8 out of 20 samples (frequency of detection 40%). In the agricultural samp les, bifenthrin, permethrin, cypermethrin and tefluthrin we re detected (frequency of de tection 47%), while cyfluthrin, fenpropathrin and lambda -cyhalothrin were not detected (n = 49). Ten of 17 urban sediment samples tested were significantly more toxic to H. azteca than the controls. Only one of the agricultural sediment samples was significantly more toxic than the controls. The major source of TUs were the pyrethroids (in pa rticular, bifenthrin). It was indicated that the detections of fenpropathrin in the urban samples was unexpected because it is a pesticide primarily used in agriculture.

LeBlanc & Perkins, 2009, documented the presence of synthetic pyrethroids in Maine sediments. Of five synthetic pyrethroids monitored, only bifenthrin was de tected, at levels of 1.26 – 16.68 ng/g (means). The other synthetic pyrethroids monitored were lambda -cyhalothrin, permethrin, cyfluthrin and cypermethrin. Four sediments were monitored: Mill Creek Lower Intertidal, Mill Creek Upper Intertidal, Back Cove and Payson Park.

Weston 2007 said that, “Contrary to popular perception, non-agricu ltural use of pyrethroids far exceeds agricultural use, at least in California, one of the few ar eas where data are available. A similar situation is likely elsewhere where ther e is substantial urban development. Whereas agricultural use of pyret hroids in California is about 300,000 lb /yr, non-agricultural commercial use (mostly applications done by professional pe st control firms) is currently about 700,000 lb/yr. Retail sales to homeowners are not incl uded in this non-agricu ltural figure, but are probably about another 100,000 lb/yr. Some of the major urban uses of pyrethroids include cypermethrin and permethrin for termite cont rol, permethrin to maintain landscaping, and bifenthrin and cyfluthrin for a variety of pests around homes.”

Analysis of pyrethroids has not b een limited to sediments. Weston et al. 2009b, found that bifenthrin was the most frequently detected pyr ethroid from runoff wate rs from Roseville and Elk Grove urban sites. Cyfluthrin and perm ethrin were also de tected frequently. Lambda

cyhalothrin was detected in two out of eight samples at a maxi mum concentration of 7 ng/L in the wet season, but it was not detect ed in the four samples of the dry season. It was noted that stormwater runoff (which occurs mostly around th e winter) was responsible for more transport than irrigation runoff (which occurs mostly around the summer), towards surface waters. Suspended sediments were found to have higher con centrations of pyrethroi ds with no apparent seasonal patterns. They contained lambda -cyhalothrin at up to 7 times the acutely toxic threshold (reported LC 50 to H. azteca of 7.2 ng/g dry weight). Th e highest concentration was 67 ng/g dry weight. It was suggested that mitigati on of the effects of the synthetic pyrethroids would need to target both sources of runoff. It was reported that the use of bifenthrin (for retail and for professional use) was higher approxi mately in the months around the summer.

In an article, Weston & Lydy 2010 studied the possi ble sources of pyrethr oids in California’s Sacramento – San Joaquin River Delta, including th ree types of samples: (a). urban runoff, (b). municipal wastewater treatment plants (or Publ icly Owned Treatment Works, POTWs), and (c).

137agricultural discharges, in a study that focused on water samples (as opposed to most of the studies above that are related to sediments). Samples were take n during the wet and dry seasons. First, urban runoff samples were taken from concrete sumps, from which pumps lift waters to adjacent rivers over levees. Sec ond, POTW effluents with secondary (and in one case, tertiary) treatment were sampled just prio r to discharge to surface waters. And finally, third, agricultural discharges were collected at pum p stations, where the runoff is lifted over the levees. Samples were tested for 8 pyrethroids and chlorpyrifos (LOQ around 1 ng/L for most samples). Tests to Hyalella azteca were also performed on the water samples. Lambda -cyhalothrin was found in 45, 17 and 11% of the samples of urban runoff, POTWs and agricultural drains, respectively. Also, 24, 17, and 9% of the samples, respectively, exceeded the EC 50 = 2.3 ng/L for H. azteca

. The maximum measured lambda -cyhalothrin concentration was 17.5 ng/L in agricultural drain samples. Through TIE, it was found that the to xicity of most samples was increased in the presence of PBO. A similar effect was obser ved when the temperature of the samples was decreased. In the presence of the enzyme E3, wh ich is capable to degrade the pyrethroids, the effect was a decreased toxici ty of the samples towards H. azteca . In the presence of bovine serum albumin (BSA), no effect on th e toxicity of the samples towards H. azteca , was observed. The pyrethroid presence in PO TWs was unexpected because the effluents had low suspended material and for the possible partitioning with bios olids within the plants. The authors indicated that possible sources of pyrethroids are sewer disposal of household in secticides, lice control shampoos, pet products and pe rmethrin treated clothing.

Lee (2009) observed the presence of pyrethroid pesticides at the inlet and outlet of four different stormwater detention ponds in Alameda and Mari n Counties, in northern California, during two rain events occurring during the winter and spri ng (2008-2009). Of the total 18 samples tested, 66% were toxic to Hyalella azteca . The most toxic samples were collected from the inlets of Heron Bay and Tysons Pond sites. Via toxicity identification evaluation (T IE), pyrethroids were considered the cause of mortality in every toxi c sample. At all sites, there was significant difference in toxicity between th e inlet and the outlet waters. The ponds showed reductions of pesticide concentrations as high as 90% (for the Tysons Pond, which is the largest detention pond). Five of 8 pyrethroids were detected in the Alameda County ponds, while only bifenthrin was detected in the Marin County pond. Bifenthr in was the most commonl y detected pyrethroid in Alameda County ponds, followed by cyfluthrin and lambda -cyhalothrin. Permethrin and cypermethrin were also detected, but at small co ncentrations. Samples with less than 1 toxic unit (<1 TU) generally were non-toxic to H. azteca while samples with >2 TUs were toxic. The fall samples overall had higher populations of H. azteca (as measured 1 week after the first significant rain event (11/08), co mpared to those sampled 1 week after the last rain event (3/2009). The author indicated that the numbe r of amphipods could not correlate solely on pesticide concentrations, but that other factors may be present.

The presence of pyrethroids and fipronil in se diments from an urban estuary was presented recently by Lao et al. (2010). They tested sediments from the Ballona Creek (in Los Angeles, CA), for eight pyrethroids (including lambda -cyhalothrin), using two gas chromatographic methods. The observed, that “permethrin, bifent hrin, and cypermethrin were the most abundant compounds.” In the 18 sediment samples tested from the Ballona estuary, seven of the eight pyrethroids were detected (excep t fenpropathrin). The sum of t oxic units (TU) of pyrethroids (based on the LC 50 to Hyalella azteca and the observation that H. azteca is approximately twice

138as sensitive to pyrethroids to Eohastorius estuarius , a toxicologically re levant species) was estimated and found to significantly correlate to percent mortality of E. estuarius . The lambda

cyhalothrin TU values exceeded 1 (one unit) for 3 out of 18 sediment samples. Concentrations and TUs of fipronil and degradates were relativ ely low. The spatial pattern of pyrethroid concentrations correla ted with fine grained sediments with higher organic carbon (OC) concentrations. The pyrethroids alone did not e xplain the observed toxicity of three sediments with relatively low sum of TU of pyrethroids; the authors indicated that it was possible that other toxicants may be present in the sediments.

Pyrethroids were also documented in urban wetlands in southern California, by Brown et al. (2010), in another recent article. In this extensive study, the team measured sediment toxicity, chemistry and macroinvertebrate (MI) community metrics for 21 southern CA wetlands that received urban runoff (plus 2 reference wetlands) . Several metals, PAHs, PCBs, organochlorine, organophosphate and pyrethroid pesticides were te sted (10 pyrethroids an d pyrethrins, including lambda -cyhalothrin). Lambda -cyhalothrin exceeded the Hyalella azteca LC 50 (1 toxic unit, TU) in 5 out of 23 sites, but it was detected in 8 site s (it was not detected in the reference sites). Bifenthrin exceeded 1 TU in 13 out of th e 23 sites. Ten sites were toxic to H. azteca . Via chemical analysis and toxicity identification eval uation (TIE), the pyrethroids were identified as the most plausible cause for the decreased survival to H. azteca species. It was found that an index of the degree of sediment contamination correlated negatively with the MI diversity in the wetlands.

In an effort to understand the fate of various in secticides on hardscapes such as concrete, Jiang et al . (2010) measured the wash-off pot ential of pesticides from impervious (concrete) surfaces, as possible source of pesticide runoff following applications around homes. Four model pyrethroids were used, including lambda -cyhalothrin, and the insecticid e fipronil. They studied two formulations of lambda -cyhalothrin (granular and liquid), sp iking concrete disks as per label recommendations and transferring them to outdoors under sunlight. After va rious intervals, the concrete disks were subjected to washing with water (samples were equilibrated with 0.01 M CaCl 2 solution). In general, the pe rcent of pesticide transferred to water decreased with time, but it followed a biphasic pattern, with rapid decrease approximately during the first 7 days (112 day study duration). Data from both phases fitted first order decay with good correlations, with certain exceptions. The DT 50 s for lambda -cyhalothrin were as follows: the initial (0-7 days) half-lives were 1.1 and 2 days for the liquid form ulation and granule, re spectively. Final halflives were 6.2 and 35.7 days for the same formul ations, respectively. The solid formulations ( e.g. , the granule for lambda -cyhalothrin) appeared to be mo re persistent overall, which was attributed to the solid carrier materials, which may have shielded the test substance from exposure to the elements. For lambda -cyhalothrin, the washoff for the day 0 samples was the lowest of all the pyrethroids ( 4.3% and 7.9% for the liquid and the granule, respectively). It was speculated that the insecticides may have been ir reversibly retained by co ncrete. Also, washed concrete disks pulled 56 days af ter treatment were thoroughly ex tracted to determine how much pesticide remained in the concrete. Af ter this period of 56 days, 11.0% of the lambda

cyhalothrin was extracted with the first acetone extraction from the washed concrete disks treated with granular formul ation, and only 1.0% from the ones treated with the liquid formulation. In an experiment assessing repeat ed washes of concrete surfaces, it was observed that the granule formulation of lambda -cyhalothrin was among the most persistent treatments.

139The authors suggested that concrete surfaces ma y serve as reservoirs or repositories of pyrethroids for extended periods of time, and were possibly “retaine d below the surface, likely in the micropores, due to physical trapping or chemical sorption.”

Another effort to study pyrethroids on impervi ous surfaces was offered by Jorgenson and Young (2010). They studied the washoff profiles among di fferent formulations, and were led to also study the effects of inert ingredie nts such as surfactants on the wash-off from concrete surfaces. Four pyrethroids (three types of formul ations and five products), including lambda -cyhalothrin (EC dilutable formulation), were used. Analysis of the formulations te sted revealed complex mixtures. It was determined analytically th at four of the five products contained linear alkylbenzene sulfonate surfactant (LAS) at variou s concentrations; thus, LAS was selected as a model surfactant to determine th e role of formulation components on pyrethroid wash-off. The experiments included: form ulated products (including lambda -cyhalothrin), neat pyrethroids (only esfenvalerate and bifenthrin), and pyret hroid plus LAS (only bifenthrin). These researchers used a rain simulator to model r unoff events. For the pyrethroids, during a runoff event, an initial rapid dissipation was followed by a steadier rate of wash-off in most instances (named Type A profile). In other instances, a relatively constant rate of pyrethroid wash-off during the whole runoff-event was noted (named Type B profile). Lambda -cyhalothrin EC had the third highest wash-off factor in the order of percentages of the total mass applied. Increasing the set time decreased the wash-off for all the pr oducts. It appeared that the EC formulation tended to yield Type B profiles, as observed for lambda -cyhalothrin and esfenvalerate. When bifenthrin and esfenvalerate were applied in hexane (as opposed to formulation), the dissipation followed the Type B profile. Testing of bifenthrin with LAS surfactant alone, resulted in a Type A profile, and in an increase (7-fold) of the total mass wash-off and of the event mean concentrations (EMC). However, the total mass removed was not as high as for the formulation 2007 Bifenthrin CE (microemulsion RTU). The authors indicate that the complexities and differences of a formulated product may be res ponsible for the behavior (order of magnitude differences) of the pyrethroids on concrete surfaces.

Solomon et al . (2001) evaluated the distribut ion analysis of laboratory aquatic toxicity data for several pyrethroids. For lambda -cyhalothrin, the 10 th centile value for all organisms was 10 ng/L (n = 9). The most sensitive species was A. bahia . Two species were omitted because their effects concentrations were in exces s of the chemical’s solubility limit.

In an in-stream mesocosm study, Heckman a nd Friberg (2005) studi ed the impact of lambda

cyhalothrin on aquatic biota. The study was designed such that the main route of exposure was through the water phase due to uni directional current (stream), wh ich in turn, allowed for the measurement of catastrophic dr ift as an endpoint. Pronounced catastrophic drift was found for several taxa, which was also dose dependent a nd species specific. For the low doses, the macroinvertebrate communities were stabilized fast . The lowest concentrations measured were indicated to occur under actual use of lambda -cyhalothrin while the highe st concentrations were indicated to represent worst case conditions.

In another in-stream design study (Lauridsen and Friberg 2005), stream m acroinvertebrates were exposed to 1-hour pulse of lambda -cyhalothrin at concentrations ranging from 0.001 to 1.0 μ g/L. The setup of the experiment was described as seminatural outdoor experimental (stream

140microcosms). The drift response was concentration dependent. Gammarus was found to be the most sensitive species. Two insect and one amphipod species responded with catastrophic drift even at the lowest concentration (amphipod Gammarux pulex ) and at 0.01 μ g/L (insects Beatis rhodani and Leuctra fusca/ digitata ).

Van Wijngaarden et al . (2006), and Van Wijngaarden et al . (2009), published microcosm studies conducted on lambda -cyhalothrin and gamma -cyhalothrin, respectively. The first study used macrophyte dominated experimental ditch systems tr eated in spring and late summer. No major treatment related differences were observed between seasons. Only slight and transient effects were observed at the community level in the lowe st treatment level (10 ng/L). In the second study, a laboratory derived HC 5 (based on eight species) was 2.12 ng/L for gamma -cyhalothrin, compared to the multi-species ecosystem NOEC community of 5 ng/L, which were considered comparable.

Kumar et al . 2007 determined the acute 96-hour LC50 of the freshwater species Channa
punctatus towards cypermethrin and lambda -cyhalothrin. The latter was around 50x more toxic with an LC 50 of 7.92 μ g/L. An EC formulation was used in this test for both chemicals. Effects on behavioral patterns were observe d at concentrations as low as 0.8 μ g/L.

In 2008, He et al . (of CalDPR and CalEPA) published a comprehensive summary that included physicochemical properties, ecological effects and environmental fate of lambda -cyhalothrin. The article provides information from literature as well as approved documents and databases. Only one highlight is in cluded here. Citing Hamer et al . (1999) information about the bioaccumulation of lambda -cyhalothrin to Chironomus riparius in 10 water/sediment systems, exposed for a period of 48 hours, it was found that the BCFs were nearly independent from the sediment. BCFs ranged from 1,300 to 3,400 (mean 2,300, coefficient of variation 25%), based on aqueous phase concentrations. The results support the equilibrium partitioning theory.

A study was performed to assess the ri sk of various formulations of lambda -cyhalothrin to aquatic organisms in paddy field in China (Gu et al . 2007). Four tests species were used (zebra fish, shrimp, crab and clam species). Shrimp was found to be much more sensitive than zebra fish to both formulations of lambda -cyhalothrin, but the 2.5% SC formulation was found to be less toxic to both species. Lambda -cyhalothrin concentrations decreased to below the limit of detection after 5 days of application in th e simulated paddy field. The WP and the EC formulations dissipated faster than the SC formulation. In the wate r, the reported half-lives were 0.23 to 0.53 days; the half-lives in the soil were 0.96 to 7.35 days. The water in the paddy field ws drained to a pond from 1 to 4 days after pesticide application. It was found that all formulations were safe to shrimp the fourth day.

A comparison of the acute toxicity of lambda -cyhalothrin and gamma -cyhalothrin towards two species (zebra fish and shrimp) was conducted by Wang et al . (2007). The 96-hour LC 50 towards zebra fish was found to be similar for both chemicals (1.94 and 1.93 μ g/L for lambda - and

gamma -cyhalothrin, respectively). However, both ch emicals were much more toxic to shrimp (respective LC 50 s of 0.04 and 0.28 μ g/L). In the same study, they observed the fate and effects of these chemicals in simulated rice paddi es. Following a holdi ng period of 96 hours, no lambda -cyhalothrin or gamma -cyhalothrin was detected in the water; but after diluting 5x the

141water, it was still toxic to shrimp. Following a holding period of 7 days and a 5x dilution of the water, neither lambda - nor gamma -cyhalothrin were toxic to zebra fish or shrimp.

In 2009, Giddings et al . compared the toxicities of lambda -cyhalothrin and gamma -cyhalothrin towards aquatic invertebrates and fish. They fou nd using a range of species tested for regulatory purposes, and species sensitivity distribution curves, that gamma -cyhalothrin was approximately twice as toxic as lambda -cyhalothrin. Since the application rate for lambda -cyhalothrin is twice that for gamma -cyhalothrin, they concluded that the aquatic risks of these chemicals were in essence the same.

C. Xu et al . (2008) separated the enantiomers of lambda -cyhalothrin using HPLC with various chiral stationary phases. They found that the (-) enantiomer was mo re toxic to zebra fish than the (+) enantiomer using standard acute tests and em bryo tests. The (+) or (-) assignment was done based on their circular dichroism (CD) detector response, coupled with HPLC. The 96-hour LC 50 was found to be 0.875 μ g/L for the racemate, 0.740 μ g/L for the (-) enantiomer and <0.012

μ g/L for the (+) enantiomer. For the embrios, the 96-hour LC 50 was 1.30 mg/L for the racemate and 0.18 mg/L for the (-) enantiomer. The lowest malformation 96-hour EC 50 were 0.03, 0.09 and 0.03 mg/L for the racemate, the (+) enantiomer, and the (-) enantiomer, respectively.

Much work has been done with lambda -cyhalothrin and its partitioning with vegetation. Hand et al . (2001) investigated the infl uence of aquatic plants on the fate and behavior of lambda

cyhalothrin, the extent of adsorption to the plants, and the metabolism of lambda -cyhalothrin in water/ plant systems. The mean adsorption K P (the concentration of the analyte in the plant material divided by the concentration in the water) were 1,100 and 1,800 L/Kg for two aquatic plant species (see also report MRID 44861507, suppl emental). Secondly, the authors assessed the metabolism of lambda -cyhalothrin in aquatic plants. In the test system, 40-50% of the activity was adsorbed to the plant tissue at 1 day, while >70% of the ra dioactivity was in the water after 14 days. Formation of Compound Ia wa s mainly responsible fo r this radioactivity.
For lambda -cyhalothrin, the DT 50 in the aqueous phase and the to tal system was <1 day. Finally, in an indoor aquatic microcosm st udy, by 1 day <10% of the applied lambda -cyhalothrin was in the water column and 4.3% was in the plant tissu e and 5% of the applied was in the sediment by the second day, when a plateau was reached in the sediment. Compound Ia, which was mainly associated with the water, reached 42% of the applied by 4 days. The dissipation DT 50 of lambda -cyhalothrin in the water column and the tota l system were found to be <3 hours (in both cases). It is noted that in the microcosm, a pH of 9.8 was observed, which may have promoted the hydrolysis of lambda -cyhalothrin; however, the study suggests that aquatic plants may affect the fate of this chemical in aquatic environments (see also report MRID 44861508, supplemental).

Moore et al . (2001) reported on the effects of agricu ltural vegetated drainage ditches in the Mississipi Delta area on atrazine and lambda -cyhalothrin after simulating a storm runoff event. Sampling occurred over a 28 day period. After only 1 hour, mean percentages of lambda

cyhalothrin in water, sediment and plants were only 12, 1 and 87%, respec tively (indicating that the plant tissue adsorbs much of the chem ical). After 24 hours, 97 and 3% of the lambda

cyhalothrin was associated with the plant materi al and the sediment, re spectively. The observed half-lives were 14.3, 15.1 and 4.6 days in the plant material, sediment and water, respectively. It

142was predicted through regression anal ysis that the concentration of lambda -cyhalothrin would be below a no effect concentration of 0.02 μ g/L 50 meters down the ditch.

Copper et al . (2002) also explored the potential of ag ricultural drainage ditches to mitigate pesticides in the Mississippi Delta region. In the first part of this study, atrazine and lambda

cyhalothrin were used while in the second part bifenthrin and lambda -cyhalothrin were used. Within 3 hours of a simulated rain ev ent, 97% and 96% of the measured lambda -cyhalothrin was associated with the ditch vegetation in the firs t and the second parts of the study, respectively. At the end of the study 2 ± 1% and 12 ± 16% of the lambda -cyhalothrin was associated with the sediment for the first and second part of the study, respectively. The authors discussed that ditch vegetation could play an important role in trap ping pesticides associated with runoff, and in particular, the pyrethroids used on cotton in MS.

The fate of lambda -cyhalothrin in experimental ditch en closures with variable levels of vegetation and a silty clay loam se diment layer was studied by Leistra et al . (2003). The nominal applied concentration was base d on a 5% spray drift event (at 0.25 μ g/L). Applications were performed in May and in A ugust. They observed that the lambda -cyhalothrin concentration in the water decreased rapidly; the concentrations of the chemical were lower in the enclosures with phytoplankton than in the ones with macrophyt es. In the August experiment, the concentration of lambda -cyhalothrin was found to be lower with greater plant mass, a trend observed at 1 and 3 days. After 7 days, the concentrations of lambda -cyhalothrin were very low. Up to 12% of the dose was found in the sediments. The authors indicated that the most likely route of dissipation of lambda -cyhalothrin is alkaline hydrolysis in the water. The mean pH values were 9.5-10 (registered at noon) in May and 7.6 in August. Another possible route of dissipation identified was aqueous photolysis.

In 2005, Bouldin et al . evaluated the fate and effects of two pesticides (atrazine and lambda

cyhalothrin, separately and in combination), in vegetated and unvegetated microcosm in a greenhouse. Study design included atrazine, lambda -cyhalothrin, a combination or control, in two vegetated monocultures and in a field and ditch sediment-types (a total of 12 microcosms). Samples were collected from 3 hours to 28 da ys postapplication. At 3 hours, the highest concentrations of lambda -cyhalothrin were registered. Based on the results, the authors concluded that vegetation provide s increased binding sites for both chemicals and that they may be important in the remediat ion of pesticides. They i ndicate that diverse macrophyte communities may be required due to the possibl e co-occurrence of chemicals with diverse chemical properties.

Bennett et al . (2005) evaluated the retention and partitioning of two pyrethroids (bifenthrin and lambda -cyhalothrin) in vegetated agricultural ditche s in the area of the Mississippi Delta, the possible role of aquatic plants to mitigate such chemicals, and the drainage ditch lengths required to mitigate the two pyrethroids. They simula ted a runoff event by applying bifenthrin and lambda -cyhalothrin into a 650-meter ditch segment with approximately 88% vegetative cover. Sampling of water, plant and sediment revealed that concentrations in water decreased rapidly with distance. This behavior was consistent during the initial 14 da ys of the study. The maximum lambda -cyhalothrin concentration measured at 3 hours (distance of 0 meters) was 375

μ g/L. During and after 14 days, concentrations were below 0.02 μ g/L. The maximum

143concentration in plant tissue and sediment was 8.79 mg/Kg (dry weight) within 50 meters of the inlet and 0.0538 mg/Kg with in the first 25 meters of the d itch system, respectively. Based on regression analysis, of concentrations in water, it was found that the firs t 120 meters of the ditch would reduce the concentra tions of bifenthrin and lambda -cyhalothrin to 1% of the initial value, and 0.1% within 280 meters. Material balance showed that the majority of these pyrethroids were in the plant compartment by 12 hours, show ing that this compartment may be important and effective in the mitigation of the tested subs tances. It was indicate d that relatively little partitioning with the sediment was due to the dense plant community.

Moore et al. 2007 examined the use of constructed we tlands in Leflore County, MS to mitigate exposure and ecological impacts in runoff from ag ricultural fields. The synthetic pyrethroids cyfluthrin and lambda -cyhalothrin were used as mode l contaminants. Testing with Hyalella

azteca was performed to determine the efficiency of the system. There was spatial and temporal variation of the two pyrethroids’ concentrations in water, sediment and leaf litter in all three wetland constructed cells. By 61 days, there were l ittle or no pyrethroids in water or leaf-litter. The concentration of the pyrethroi ds decreased with distance fr om the application point, but there was no decrease in the H. azteca toxicity in water during the 61-day observation period even though the pyrethroids’ concentrations decreas ed significantly. The authors concluded that the pyrethroids can move, affecting non-target aquatic organisms for weeks to months after entering a constructed wetland.

In 2009, Moore et al. also used cyfluthrin and lambda -cyhalothrin in constructed wetlands (comprised of a sediment retention basin, and tw o treatment cells) in a study lasting 55 days. A high percentage of the measured cyfluthrin was associated with vegetation while for lambda

cyhalothrin, it was associat ed with the sediment. It was dete rmined that wetlands lengths of 210- 217 m were required to mitigate inflow of bot h chemicals from a 14 ha contributing field.

In a 3-year field te st studying honey bee ( Apis mellifera ) colony health, Chauzat et al. (2009) found no residues of cyfluthrin at levels of 0.7 μg/bee (MRID 47775501) (Note that the acute
contact LD 50 for honeybees is 0.037 μg/bee according to registrant-submitted studies). Although no statistical significant relations hips were found between colony mortality and the presence of pesticides overall, the authors state that “mor e work is needed to determine the role these residues play in affecting col ony health”. In another study, Dai et al. (2010) examined the sublethal effects of two pyrethroids, deltameth rin and bifenthrin, on bee colony health. The authors concluded that both chemicals adversel y impacted bees by reducing bee fecundity and decreasing the rate of bee development into adulthood.

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