-2 of 50- metabolism study, conducted in one sediment system should be submitted. Chemical stability will be assumed in the absence of data.

 Anaerobic aquatic metabolism study (835.4400) There are no acceptable anaerobic aquatic metabolism studies. A new anaerobic aquatic metabolism study should be submitted. Two sediment systems are required. Submission of an acceptable anaerobic aquatic metabolism study is necessary to unde rstand the degradation of tefluthrin in oxygen-limiting environments. Chemical stabilit y will be assumed in the absence of data

 The environmental chemistry analytical me thods and independent laboratory (ILV) portions (only) of the terrestrial fiel d dissipation (835.6100) a nd the aquatic field dissipation study (835.6200) ra ther than the full fi eld dissipation study.

The available effects dataset is considered incomplete for the purposes of risk assessment. The following data gaps exist:

 Freshwater and estuarine/marine spik ed whole-sediment chronic tests , TGAI.
Test Method 100.4 (OCSPP 850.1770, in prep .); Whole sediment: ch ronic invertebrates freshwater ( Hyalella azteca ) Test Method 100.5 (OCSPP 850.1760, in prep .); Whole sediment: ch ronic invertebrates freshwater ( Chironomus dilutus ) EPA 600/R-01/020 (OCSPP 850.1780, in prep. ); Whole sediment: chro nic invertebrates marine ( Leptocheirus plumulosus ) . There are no data availabl e regarding chronic toxicity of tefluthrin to benthic organisms, an expos ure compartment of concern. For pyrethroids, spiked whole sediment chronic toxicity data for Hyalella azteca
, Chironomus dilutus , and Leptocheirus plumulosus are necessary for risk assessment.

 Aquatic Invertebrate TGAI Acute Toxicity with Hyalella azteca (Non-guideline special study). Available information indicates that the freshwater amphipod, H. azteca
, is substantially more sensitive to pyrethroids than Daphnia magna , the commonly tested freshwater invertebrate ( e.g. , Anderson et al. 2006; Maund et al. , 2002). Therefore, in order to ensure that risks to sensitive aquatic invertebrate s are appropriately quantified additional acute toxicity testing of H. azteca is needed (water-onl y exposure tests, no sediment present).

 Mysid Chronic Toxicity study (GLN 850.1350)

. As discussed in the document, mysids are generally far more acutely sensitive to tefluthrin than daphnids and exposure to estuarine/marine environments is likely. In th e absence of these data, an acute-to-chronic ratio based on the daphnid data would be used; however this may result in underestimation of potential risk.

 Avian acute oral study with a passerine (GLN 850.2100). Data on the toxicity of tefluthrin to passerines are necessary for risk assessment. A registrant submission examining the potential toxicity of tefluthrin to the house sparrow ( Passer domesticus ; MRID 40161123) is being reviewed to determine if it can be us ed to fulfill this data requirement. Provisionally, the study indicates passerines as more sensitive to tefluthrin than bobwhite or mallard.-3 of 50-  Honey bee acute contact toxicity study (GLN 850.3020). No data are available to assess the potential toxicity of tefluthrin to beneficial invert ebrates. As an insecticide, effects to terrestrial invertebrates are exp ected, but a hazard th reshold has not been established.

 Aquatic vascular plant study (GLN 850.4400). There are no data available regarding the toxicity of tefluthrin to aquatic vascular plants. Aquatic ecosystems are likely to be exposed to tefluthrin through eros ion of treated soil pa rticles to which it is sorbed. These data are necessary for risk assessment.

 Aquatic non-vascular plant testing: one for each of 4 species (GLN 850.5400). There are no data available regarding the toxicity of tefluthrin to aquatic non-vascular plants. Aquatic ecosystems are likely to be exposed to tefluthrin through er osion of treated soil particles to which it is sorbed. These da ta are necessary for risk assessment.

 Terrestrial Plant Toxi city-Seedling Emergence (GLN 850.4100). No data on the toxicity of tefluthrin to terrestrial plants is available. Because tefluthrin may runoff the treated field to nontarget areas, effects to terrestrial plant s eedling emergence may occur. Due to the current use patterns, spray drift is not expected therefor e a vegetative vigor study is not necessary at this time.

Additional detail on the current data gaps for e nvironmental fate and effects for tefluthrin is provided in Section 8.0.

Additional data needed for the risk assessment include label clarification. According to the LUIS report, tefluthrin use is not limited in number of applications. While it appears that tefluthrin is only applied at plan ting, verification and appropriate la bel statements will clarify this issue. Additionally, rates are pr ovided only as lbs ai /linear foot or lbs ai/lb of seed. The registrant indicated in a Focus Meeting on A ugust 14, 2012 that the labels would be updated to limit applications to once per year and specify the maximum amount of active ingredient on a per acre basis. The risk assessment will be based on the stamped labels current at the time of the
assessment.-4 of 50- 

### Problem Formulation for the Enviro nmental Fate and Ecological Risk, Endangered Species, and Drinking Wa ter Assessments in Support of the Registration Review of Tefluthrin

CAS Registry Number: 79538-32-2 PC Code: 128912

P

repared by: Brian D. Kiernan, Biologist Ibrahim Abdel-Saheb, Ph.D ., Environmental Scientist U. S. Environmental Protection Agency Office of Pesticide Programs E nvironmen t al Fate and Effects Division E nvironmental Risk Branch VI 1200 Pennsylvania Ave., NW M

ail Code 7507P Washington, DC 20460 R eviewed by: Elizabeth Riley, Biologist Reuben Baris, Environmental Scientist Stephanie Syslo, RAPL William Eckel, PhD, Acting Branch Chief, ERB 6

August 30, 2012-5 of 50- 1. Purpose

The purpose of this problem formulation is to pr ovide an understanding of what is known about the environmental fate and ecological effects of the registered uses of tefluthrin (PC Code 128912). Tefluthrin is a synthetic pyrethroid inse cticide. Its structure has two rings, one phenyl ring and a cyclopropyl ring. It is not substituted in the alpha position (thus, it is a type 1 synthetic I . pyrethroid).

Currently, tefluthrin is register ed for use on corn as a granular formulation as well as a seed treatment and on sugar beet as a seed treatment. Tefluthrin is formulat ed as a granular and emulsifiable concentrate.

The granular formulation may be applied either at-plant or layby (during cultivation). The atplant applications may be made via band trea tment or furrow treatment (required for highly erodible soils). For the band treatment, the granules must be incorporated into the top 1 inch of soil. Layby applications may be made by placing th e granules at the base of the plant and then covering them with 2-3 inches of soil on each side.

Tefluthrin's mode of action, like other pyrethroids, is to prevent the sodium channels in an organism's neuronal membranes from closing, causi ng paralysis as the nerves cannot revert to a de-excited state.

This document will provide a plan for analyzing data relevant to tefluthrin and for conducting environmental fate and ecological risk, endange red species, and drinking water assessments for its registered uses. Additionally, this problem formulation is intended to identify data gaps, uncertainties, and potential assumptions used to address those uncertainties relative to characterizing the ecological risk associated with the registered us es of tefluthrin.

2. Problem Formulation

2.1. Nature of Regulatory Action

Under the Federal Insecticide, F ungicide, and Rodenticide Act (FIF RA), all pesticid es distributed or sold in the United States generally must be registered by the Environmental Protection Agency (EPA). As part of determining whether a pesticide can be registered in the U.S., the Agency evaluates its safety to non-target spec ies based on a wide range of environmental and health effects studies. In 1996, FIFRA was amended by the Food Quality Protection Act, and the Agency was mandated to implement a new program for the periodic review of pesticides, i.e
., Registration Review ( http://www.epa.gov/oppsrrd1/registration_review/ ). The Registration Review program is intended to ensure that, as th e ability to assess risk evolves and as policies and practices change, all register ed pesticides continue to meet the statutory standard of no unreasonable adverse effects to human health and the environment. Changes in science, public policy, and pesticide use practic es occur over time. Through th e Registration Review program,-6 of 50- the Agency periodically reevaluates pesticides to make sure that as change occurs, products in the marketplace can be used safely.

As part of the implementation of the Registratio n Review program pursuant to Section 3(g) of FIFRA, the Agency is beginning its evaluation of te fluthrin to determine whether it continues to meet the FIFRA standard for registration. This problem formulation for the environmental fate, ecological risk, endangered species, and drinking water assessment chapter in support of the Registration Review will be posted in the initial docket, which will open the public phase of the review process.

2.2. Previous Assessments

 Tefluthrin was registered by the US Envi ronmental Protection Agency (EPA) as an insecticide for use in corn in 1989.

 Drinking Water Assessment for the Proposed New Use of Tefluthrin (Force@ SB) as a Seed Treatment for Sugar Beets (DP Barcode D369420; August 11, 2010). Thedocument reports EDWCs for corn to be 259 ppt (surface water acute), 8.74 ppt (noncancer chronic) and 6.06 ppt (cancer ch ronic), respectively, and the SCI-GROW groundwater concentration as 1.0 ppt, suitable for both acute and chronic exposures. The new use on sugar beets resulted in negligible EDWCs.

 Environmental Fate and Ecological Risk Assessment for the Proposed New Use of Tefluthrin on Sugar Beet as a Seed Tr eatment (DP Barcode: 374771; June 16, 2010). In this assessment, acute and chronic risk s for avian and mammalian species were determined to be above the Agency’s leve l of concern (LOC) fo r listed and non-listed species. Risks could not be estimated for terr estrial and aquatic plants as no studies were submitted that characterized toxicity to thes e taxa. However, as tefluthrin was being proposed as a seed treatment with an incor poration of soil of at least 1 inch, leaching from the seed was not expected. With a very high K OC value of ≥ 100,000 mL/g OC and a classification as hardly mobile to immobile, lo w risk to these taxa is expected due to the chemical likely remaining adsorbed to the s eed. For aquatic organisms in both the water column and sediment pore water, risk was dete rmined to be several orders of magnitude below the LOC. Despite high toxicity to fish and aquatic invertebrates, the chemical has a high K OC value and is not expected to leach off of the seed and enter the aquatic environment. No LOCs were exceeded for a ll freshwater and marine/estuarine fish and invertebrates.

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 indicated that substances with mixed characteristics could be included in both gr oups (see p. 18 of SAP minutes, USEPA 2009). The natural pyrethrins are Type I pyrethroid inse cticides, with no cyano-substitution in the alpha

--7 of 50- position. 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 ma terial available at http://www.regulations.gov ) under EPA-HQ-OPP-2008-0489.

EFED does not currently conduct cumulative ecologi cal risk assessments for several reasons. Specifically, the Division does not currently ha ve the methodology to conduct similar cumulative risk assessments for all of the (non-human) biological entities for which EFED has responsibility. In addition to a ddressing the toxicological aspect s of the cumulative effects of multiple pyrethroids to multiple biological entities, a cumulative ecological risk assessment would likely require consideration of exposure at a watershed scale in order to inco rporate spatial and temporal variability in pyrethroid applications into cumulative exposure assessment. EFED does not have the modeling tools developed for conducting this type of assessment. However, EFED will consider open literature, currently available models and other lines-of-evidence ( e.g. , monitoring data) as available, to address the potential for cumulativ e effects of pyrethroids in the risk description of the ecological risk assessment for tefluthrin.

3. Stressor Source and Distribution

3.1. Mechanism of Action

The pyrethroids (including teflut hrin) share similar modes of ac tion, and are considered axonic poisons that affect both the periph eral and central nervous system. It is now well established that severe neurological symptoms of poisoning with pyrethroids in mammal s and insects are the result of modification of Na + channel activity (cellular pores through which sodium ions are permitted to enter the axon to cause excitation) . Advanced electrophysiological experiments using a voltage clamp and a patch clamp, t ogether with ligand-binding and ionic flux experiments, have unveiled unique acti ons of pyrethroids of keeping the Na + channel in the open state for an extremely long period, sometimes as long as several seconds. This modification of Na + channel properties leads to hyper activity of the nervous system. Pyrethroids have also been shown to suppress GABA and glutamate receptor-c hannel complexes and voltage-activated Ca 2+ channels, but the toxicological significance of these actions is uncertain. Relative to physiological responses, researchers have desi gnated two types of pyrethroids, Type I ( e.g. , pyrethrins, bioallethrin, d-phenothrin, resmethrin, te fluthrin) and Type II ( e.g. , cypermethrin, deltamethrin). In Type I pyrethroids, such as te fluthrin, the action is ma inly associated with compounds that cause nerve excitation symptoms t ypified by the appearance of repetitive firing of axons in the peripheral nervous system a nd a negatively correlated temperature-reversible knockdown property.

3.2. Overview of Pesticide Use and Usage

Tefluthrin is a synthetic pyrethroid insecticide formulated as a granular and emulsifiable concentrate. Tefluthrin is registered for use on corn and sugar beet.-8 of 50- One of the liquid formulation products is only fo r use by commercial seed treaters. It may be applied to corn seeds using eith er liquid seed treating equipment or seed coating equipment. In the field, tefluthrin may be applie d as a spray at the time of planting. Spray applications may be made as either a T-band or furrow treatment, both requiring soil incor poration to 1 inch.

The granular formulation may be applied either at-plant or layby (during cultivation). The atplant applications may be made via band trea tment or furrow treatment (required for highly erodible soils). For the band treatment, the granules must be incorporated into the top 1 inch of soil. Layby applications may be made by placing th e granules at the base of the plant and then covering them with 2-3 inches of soil on each side.

The application rate varies with the formulati on used, stage of weed growth, and application timing ( Table 1 ).

Additional data needed for the risk assessment include label clarification. According to the LUIS report, tefluthrin use is not limited in number of applications. While it appears that tefluthrin is only applied at plan ting, verification and appropriate la bel statements will clarify this issue. Additionally, rates are pr ovided only as lbs ai /linear foot or lbs ai/lb of seed. The registrant indicated in a Focus Meeting on A ugust 14, 2012 that the labels would be updated to limit applications to once per year and specify the maximum amount of active ingredient on a per acre basis. The risk assessment will be based on the stamped labels current at the time of the
assessment.-9 of 50- Table 1. Registered products containing tefluthrin.

MCAP: Microencapsulate NS: Not specified Reg# AI % For mul atio

n Product Name Max App Rate Max # Apps Season al Max

Rate Min. Retreat

ment Interval Appl. Method

Type Appl. Method Appl. Timing

100-1075 3 G FORCE 3G INSECTICIDE .00000938 lb / linear ft NS NS NS Soil band
treatment

Soil infurrow
treatment

Soil
treatment(Tbanding). Soil incorporation

equipment. At
emergence

through seedling

stage.

At planting

Layby

100-1087 26.8 EC FORCE ST INSECTICIDE .00526871 lb / lb

to

.00078055

lb / lb NS NS NS Seed
treatment Coating machine

Liquid seed
treater

Slurry-type seed treater At plantingPreplanting

100-1253 23.4 MC AP FORCE CS INSECTICIDE .00000911 lb / linear ft
to .00000927 lb / linear ft NS NS NS Soil infurrow
treatment

. Soil
treatment(Tbanding). Microtube. Sprayer

Soil incorporation

equipment At planting

100- XXXX (Registrati
on status uncertain) 19.1 EC FORCE SB 0.0161 lbs ai/A NS NS NS Seed
treatment Coating machine

Liquid seed
treater

Slurry-type seed treater Pre-plant-10 of 50- Figure 1 spatially represents tefluthrin use intens ity in the United States . Figure 2 presents the States with highest te fluthrin use as a pe rcent of total use.

Figure 1. Tefluthin Usage by Crop Reportin g District from 2006-2010 (USDA, 2010).

According to the Biological and Economic Analysis Division’s (BEAD), the states with the most agricultural usage in terms of pounds a.i. applied for the y ears 2006-2010 are Illinois (47%), Indiana (15%), Nebraska (12%), Iowa (8%), Mi nnesota (5%) and Wisconsin (5%) (Figure 2). These states ranked similarly in terms of the total area treated (BEAD Chemical Profile for Registration Review: Tefl uthrin, March 21, 2012).-11 of 50- Figure 2. States with Highest Use (Percen t of Total Pounds AI Applied) 2006-2010

3.3. Environmental Fate and Transport Tefluthrin is a soil incorporated or seed treatme nt chemical for use on corn (at plant). When applied to the field, tefluthrin is li kely to mostly partition to the soil.

Tefluthrin appears to bind strongly to soil and organic matter (Kow= 3.16 x 10 6 , and K oc and K FOC on the order of, or greater than 100,000 mL/goc (hardly m obile to immobile, FAO 2000). Thus, it is not expected to substantially le ach into subsurfaces. It may reach aquatic environments via runoff events accompanied by erosion occurring after la rge rainfall events.

Upon hydrolysis, tefluthrin is stable at pHs 5 and 7, and relatively persistentat pH 9 (2:70% was parent compound after 0 days).

Under aqueous and soil photolysis, the major photoproduct is the trans-isomer of tefluthrin (~37% isomerization after 31 days upon aqueous photolysis). Aqueous photolysis is expected in shallow clear waters. If this happened, the trans-isomer of tefluthrin will ha ve same toxicity of the parent. On the other hand, soil photodegradation is not expected to be an important route of dissipation for tefluthrin due to its method of application. Tefluthrin appears to be moderately persistent in terrestrial envi ronments (aerobic soil metabolis m 17.4 -75.3 days; terrestrial field dissipation 12 -124 days). It has the potential to persist in aquatic environments, where it may partition to the sediment and has the poten tial to affect benthic and epibenthic.

Tefluthrin has molecular weight of 418.7 g/mol. W ith a relatively low solubility (0.02 ppm, it is considered as 'not soluble' according to the FAO solubility classifi cation, FAO 2000) and a high octanol/water partition coefficient (K ow = 3.16 x 10 6 ). Based on it octa nol/water partition coefficient, it appears that tefluthrin has the po tential to bioaccumulate, which will be explored more thoroughly in the risk assessmen t. With a vapor pressure of 1.9 x 10 -5 mmHg, and low-12 of 50- solubility (0.02 ppm), its calculated Henry's Law Cons tant is moderate (5.2 x 10 -4 atm-m3/mol). In addition, its C water/ /C air is 45, which classifies it as "rap idly lost from a water surface" (USEPA 2008).

Tefluthrin may be bioaccumulative. 

### In a bioaccumulation in fish study, BCFs reached as high as 12,800~(f or viscera) and the estimated depuration half-life was ca. 14 days. 

### In the edible tissue, 61-66% of the total [14c] residues were te fluthrin and 17-24% of the residues were unextractable.

Even though various degradates were observed in the laboratory st udies, it was found that several of them were the result of the ruptur e of the ester bond of the parent molecule. It has generally been believed that the resulting molecules are not as toxic as the parent because they presumably have lost the ne urotoxic mode of action.

Table 2 Summary of physicochemical properties of tefluthrin

. PARAMETER VALUE(S) (units) SOURCE

CAS Chemical Name (2,3,5,6-tetrafluoro-4-methylphenyl)methyl (1 R ,3 R )- rel -3-[(1 Z )-2- chloro-3,3,3-trifluoro-1-propenyl]-2,2-

dimethylcyclopropanecarboxylate Tefluthrin data sheet: http://www.alanwood.net/ pesticides/tefluthrin.html Accessed 4/14/10. IUPAC Chemical Name 2,3,5,6-tetrafluoro-4-methylbenzyl (1 RS ,3 RS )-3-[( Z )-2-chloro-3,3,3- trifluoroprop- 1-enyl]-2,2-dimethylcy clopropanecarboxylate

or 2,3,5,6-tetrafluoro-4-methylbenzyl (1 RS )- cis -3-[( Z )-2-chloro-3,3,3- trifluoroprop- 1-enyl]-2,2-dimethylcy clopropanecarboxylate

PC Code 128912 OPP Databases

Chemical Structure Tefluthrin data sheet: http://www.alanwood.net/ pesticides/tefluthrin.html Accessed 4/14/10.

CAS Reg. No. 79538-32-2 Tefluthrin data sheet: http://www.alanwood.net/ pesticides/tefluthrin.html Accessed 4/14/10. Chemical Formula C 17 H 14 ClF 7 O 2-13 of 50- PARAMETER VALUE(S) (units) SOURCE

Molecular Weight 418.7 g/mol TOXNET database: http://toxnet.nlm.nih.gov/ Accessed 4/14/10. Appearance Colorless solid.
Melting Point 44.6oC

Solubility ( 20 o C) 0.02 ppm according to FAO solubility classification. MRID 47813004 FAO, 2000
Vapor Pressure (20 o C) 1.9 x 10 -5 mmHgThe vapor pressure is between the two classifications: ‘Nonvolatile’ and ‘Intermediate to high volatility’ under field condition. MRID 47813004 USEPA, 2008

Henry’s Law Constant (20 o C) 5.2 x 10 -4 atm-m 3 /mol Reviewer calculated from VP and water solubility

Octanol-Water Partition Coefficient (20 o C) K OW = 3.16 x 10 6 and log K OW = 6.50 TOXNET database: http://toxnet.nlm.nih.gov/ Accessed 4/14/10.

Octanol-Air

Partition Coefficient

K OA (log K OA ) Constant Law s Henry' RT K
K K K OW

AW OW OA 

 = 1.5 x 10 8 (8.2),

4.68 x 10 7 (7.67) Calculated Value vs. EPISuite v.4.0 Estimate

K AW (log K AW ) K AW = C air /C water = HLC/(RT) = 0.022 (-1.7), 0.0675 (-1.17) ‘Rapidly lost from a water surface.’ Calculated Value vs. EPISuite v.4.0 Estimate

C water /C air      

    

 6 air water 10 GMW P 760 R T S
C C = 1/K AW = 45 (unitless)

‘Rapidly lost from a water surface.’ Calculated USEPA, 2008

OH Radical Reaction Half-life 0.628 days EPISuite 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 tefluthrin, log K OA > 5 (actual 8.2), log K OW > 2 (actual 6.50)

and rate of transformation is moderate in the environment and appears to be relatively slow in fish, with relatively slow depuration; it appears that tefluthrin has a potential to biomagnify in terrestrial food chains. Maximum BCFs: 750x for edible, 12,761x for viscera, 2,051x for whole fish. In edible tissue, 61-66% of the residues were parentcompound, and 17-24% was unextracted residues. The halfdepuration time for the whole fish was ca. 14 days. ** Gobas et al. 2003 and Armitage & Gobas, 2007 support this presumption

utilized here only as a

broad reference to determine the potential for biomagnification.

Table 3 shows the chemical structures of tefluthrin’s major and mi nor degradation products. At this time, at least two of them may be consid ered stressors (see the first two transformation products, which preserve the ester moiety of the parent compound). Of them, only trans

tefluthrin was a major transformation product, and it was observed in the aqueous and soil-14 of 50- photolysis studies. Due to the method of appli cation (incorporated to at least 1 inch), soil photolysis is not expected to be significant for tefluthrin.

1 Table 3. Major Transformation Products of Tefluthrin Chemical Name Structure

trans -tefluthrin 2,3,5,6-tetrafluoro-4-methylbenzyl- trans -3-(Z-2- chloro-3,3,3-trifluoroprop-l-enyl)-2,2-

dimethylcyclopropanecarboxylate NA; includes the (Z)-(1R)- trans -acid and the (Z)-(1S)- trans

acid isomers

4-carboxy-2,3,5,6-tetrafluorobenzyl (1R,3R;1S,3S)-3-(Z-2-chloro-3,3,3-trifluoroprop1-eny1)-2,2-dimethylcyclo-propanecarboxylate

Cl F3C C H 3 CH 3

O

O O

OH F

F

F F

cis-3-(Z-2-chloro-3,3,3-trifluoroprop-l-eny1)-2,2- dimethylcyclopropanecarboxylic acid

Cl F3C C H 3 CH 3

O

O OH

2,3,5,6-tetrafluoro-4-methylbenzyl alcohol O H CH 3 F

F

F F

2,3,5,6-tetrafluoro-4-methylbenzoic acid O H CH 3 F

F

F F

O

2,3,5,6-tetrafluoro-1,4-benzenedicarboxylic acid O H O

OH F

F

F F

O-15 of 50- Table 4 shows summary of the environmental fa te and transport properties for tefluthrin.-16 of 50--17 of 50- 3.4. Bioaccumulation

In a bioaccumulation in fish study, BCFs reach ed a high as 12,800x (for viscera) and the estimated depuration half-life was ca. 14 days. In the edible tissue, 61-66% of the total [14C] residues were tefluthrin a nd 17-24% were unextractable (MRID# 40141333). The potential impact of bioaccumulation in ecosystems will be e xplored in the risk assessment. However, the EPA’s PBT Profiler ( http://www.pbtprofiler.net/ ) does not support the supposition that tefluthrin is likely to bioaccumulate. The model indicates th at tefluthrin meets the criteria for persistence and toxicity, but not bioaccumulation.-18 of 50- 4. Receptors

Consistent with the process described in th e Overview Document (USEPA 2004), the risk assessment for tefluthrin relies on a surrogate sp ecies approach. Toxicological data generated from surrogate test species, which are intended to be representative of broad taxonomic groups, are used to extrapolate the pot ential effects on a variety of species (receptors) included under these taxonomic groupings.

Acute and chronic toxicity data from studies submitted by the pest icide registrant, along with the available open literature, will be used to evaluate the potential direct and indirect effects of tefluthrin to aquatic and terrestri al receptors. This includes toxi city on the technical grade active ingredient, degradates, and when available, formulated products ( e.g. , “Six-Pack” studies). Open literature studies were id entified through EPA’s publica lly available ECOTOXicology (ECOTOX) database (November 2010), which empl oys a literature search engine for locating chemical toxicity data for aquatic and terrestr ial plants and wildlife. The evaluation of both sources of data may also provide insight into the direct and indirect effects of tefluthrin usage on biotic communities from loss of species that are sensitive to the chemical and from changes in structure and functional characteristic s of the affected communities.

A brief summary of the aquatic and terrestrial toxicity data available for the species most sensitive to tefluthrin is provided in Sections 4.1 and 4.2, respectively. In addition, a summary of ecological incidents associated with tefluthrin and a description of ecosystems potentially at risk are provided in Sections 4.3 a nd 4.4, respectively. There are al so no data on the potential toxicity of any degradates. In the absence of data, a total to xic residue (TTR) approach (for relevant degradates) will be employed in the ri sk assessment. While degradate data are not required for risk assessment, the submission of de gradate studies could potentially be used to refine the upcoming Registration Review risk assessment.

Toxicity to fish and aquatic invertebrates is categorized using the system shown in Table 5 (US EPA, 2004). Toxicity to terrestrial fauna (birds and mammals) is categorized using the system shown in Table 6 . Toxicity categories for plan ts have not been defined.

Table 5. Categories of Acute T oxicity for Aquatic Animals
LC 50 (ppm) Toxicity Category < 0.1 Very highly toxic > 0.1 – 1 Highly toxic > 1 – 10 Moderately toxic > 10 – 100 Slightly toxic

> 100 Practically nontoxic

Table 6. Categories of Acute Toxi city for Terrestrial Animals
LD 50 (mg/kg) LC 50 (ppm) Toxicity Category <10 <50 Very highly toxic 10-50 50-500 Highly toxic 51-500 501 - 1000 Moderately toxic 501-2000 1001 - 5000 Slightly toxic

>2000 >5000 Practically nontoxic-19 of 50- 4.1. Effects to Aquatic Organisms

The most sensitive of the available aquatic toxicity data from registrant-submitted studies are provided in Table 7 . If there are any relevant studies available in ECOTOX, they will be reviewed for the risk assessment. Based on the av ailable information, teflut hrin is classified as very highly toxic to fish and invertebrates on an acute exposure basis. The NOAECs in the available chronic exposure studies are as low as 4 ng ai/L. More data on aquatic taxa are necessary for risk assessment as outlined belo w. There are no guideline vascular and nonvascular aquatic plants ava ilable for tefluthrin; however given the use patterns and the physical/chemical properties of tefluthrin, exposur e to terrestrial plants is expected to be minimal.

There are no data on the t oxicity of tefluthrin degradates to aq uatic organisms. In the absence of data, a TTR (total toxic residue) approach (for re levant degradates) may be employed in the risk assessment. The uncertainty in exposure estimat es induced by taking a TTR approach could be reduced if specific toxicity data for de gradates retaining the ester are submitted.

In summary, aquatic data needed or under review:

 Aquatic vascular plant study (GLN 850.4400). There are no data available regarding the toxicity of tefluthrin to aquatic vascular plants. Aquatic ecosystems are likely to be exposed to tefluthrin through eros ion of treated soil pa rticles to which it is sorbed. These data are necessary for risk assessment.

 Aquatic non-vascular plant testing: one for each of 4 species (GLN 850.5400). There are no data available regarding the toxicity of tefluthrin to aquatic non-vascular plants. Aquatic ecosystems are likely to be exposed to tefluthrin through er osion of treated soil particles to which it is sorbed. These da ta are necessary for risk assessment.

 Freshwater and estuarine/marine spik ed whole-sediment chronic tests , TGAI.
Test Method 100.4 (OCSPP 850.1770, in prep .); Whole sediment: ch ronic invertebrates freshwater ( Hyalella azteca ) Test Method 100.5 (OCSPP 850.1760, in prep .); Whole sediment: ch ronic invertebrates freshwater ( Chironomus dilutus ) EPA 600/R-01/020 (OCSPP 850.1780, in prep. ); Whole sediment: chro nic invertebrates marine ( Leptocheirus plumulosus ) . There are no data availabl e regarding chronic toxicity of tefluthrin to benthic organisms, an expos ure compartment of concern. For pyrethroids, spiked whole sediment chronic toxicity data for Hyalella azteca
, Chironomus dilutus , and Leptocheirus plumulosus are necessary for risk assessment.

 Aquatic Invertebrate TGAI Acute Toxicity with Hyalella azteca (Non-guideline special study). Available information indicates that the freshwater amphipod, H. azteca
, is substantially more sensitive to pyrethroids than Daphnia magna , the commonly tested freshwater invertebrate ( e.g. , Anderson et al. 2006; Maund et al. , 2002). Therefore, in order to ensure that risks to sensitive aquatic invertebrate s are appropriately quantified additional acute toxicity testing of H. azteca is needed (water-onl y exposure tests, no sediment present).-20 of 50-  Mysid Chronic Toxicity study (GLN 850.1350)

. As discussed in the document, mysids are generally far more acutely sensitive to te fluthrin and exposure to estuarine/marine environments is likely. In the absence of these data, an acute-to-chronic ratio based on the daphnid data would be used.

Table 7. Aquatic Toxicity Profile for Tefluthrin

MRID# Toxicity Test Endpoint (ppb) Toxicity Study Classification

00156769 00156770 Rainbow trout – Acute toxicity test 96-h LC 50 : 0.06 Very highly toxic Acceptable
Bluegill sunfish – Acute toxicity test 96-h LC 50 : 0.13 Very highly toxic Acceptable

40161137 Sheepshead minnow – Acute

toxicity test 96-h LC 50 : 0.13 Very highly toxic Acceptable

41705101 Fathead minnow – Chronic early life stage test NOAEC: 0.004 LOAEC: 0.008 - Acceptable

40161132 Daphnia magna – Acute toxicity test 48-h EC 50 : 0.07 Very highly toxic Acceptable

41229501 Daphnia magna – Chronic life cycle
test NOAEC: 0.008 LOAEC: 0.024 - Acceptable

40161136 Mysid shrimp ( Mysidopsis bahia ) 96-h LC 50 : 0.053 Very highly toxic Acceptable

4.2. Effects to Terres trial Organisms

Table 8 summarizes the most sensitiv e terrestrial toxicity endpoint s for tefluthrin, based on an evaluation of the submitted data. If open literature studies are identified through ECOTOX, they will be reviewed for the risk assessment. Teflut hrin is classified as practically nontoxic to slightly toxic to birds based on the available acu te oral and subacute dietary exposure studies; however, an acute oral study with the house sp arrow (under review) provisionally indicates tefluthrin is more toxic to pa sserines. The NOAECs for birds ar e the highest dose tested, as no effects were observed. Tefluthrin is classified as highly nontoxic to mammals on an acute oral exposure basis. Effects on pup weights were obs erved in the chronic exposure study with a NOAEC of 2.5 mg ai/kg/day. There are no data regarding the potenti al effects of tefluthrin to honey bees. Honey bees may be used as surrogate s for other nontarget ins ects, including native pollinators.-21 of 50- There are no phytotoxicity data for terrestrial pl ant species; a minimum of Tier 1 studies are required under 40 CFR Part 158. Two incident reports filed with the EPA involved adverse effects to terrestrial plants, but these were reported to be from uni ncorporated broadcast applications, which are not allowed by label. It is possible that te fluthrin may exhibit phytotoxicity to certain sensitive plant specie s, and a seedling emergence study should be submitted. Given the labeled application methods (seed treatment/soil treatment), exposure to emerged terrestrial plants off the target area is ex pected to be negligible , thus a vegetative vigor study is not necessary.

In summary, terrestrial data needed or under review:

 Avian acute oral study with a passerine (GLN 850.2100). Data on the toxicity of tefluthrin to passerines are necessary for risk assessment. A registrant submission examining the potential toxicity of tefluthrin to the house sparrow ( Passer domesticus ; MRID 40161123) is under review. Until the review is complete, it is unknown whether the study can be used to fulfill this data re quirement; however, taken at face-value, it indicates passerine species are more sensitive to tefluthrin than e ither bobwhite quail or mallard duck.

 Honey bee acute contact toxicity study (GLN 850.3020). No data are available to assess the potential toxicity of tefluthrin to beneficial invert ebrates. As an insecticide, effects to terrestrial invertebrates are exp ected, but a hazard th reshold has not been established.

 Terrestrial Plant Toxi city-Seedling Emergence (GLN 850.4100). No data on the toxicity of tefluthrin to terrestrial plants is available. Because tefluthrin may runoff the treated field to nontarget areas, effects to terrestrial plant s eedling emergence may occur. Due to the current use patterns, spray drift is not expected therefor e a vegetative vigor study is not necessary at this time.

The guideline numbers for terrestrial plants in the 40 CFR Part 158 were updated to reflect final 850 guidelines and do not reflect the numbers of the Public Draft 850 guidelines. Part 158 lists 850.4100 and 850.4150 (seedling emergence and vegetativ e vigor, respectively) for both Tier 1 and Tier 2 studies. The Public Draft guidelines 850.4100 and 850.4150 are for Tier 1 and 850.4225 and 850.4250 are for Tier 2.

Table 8. Terrestrial Toxicity Profile for Tefluthrin.

MRID# Toxicity Test Endpoint (mg ai/kg) Toxicity Study Classification

00156766 40161123 00156767 00156768 Mallard duck - Avian Oral

Toxicity LD 50 : 4190 Practically non-toxic Acceptable

House Sparrow - Avian Oral

Toxicity LD 50 : 267 Moderately toxic Under review

Mallard duck - Avian Dietary Toxicity LC 50: 2317 Slightly toxic Acceptable

Bobwhite quail - LC 50 : 15000 Practically non-toxic Acceptable-22 of 50- MRID# Toxicity Test Endpoint (mg ai/kg) Toxicity Study Classification

Avian Dietary Toxicity

40161124 40161125 Mallard duck – Avian reproduction NOAEL: 25 - Acceptable

Bobwhite quail – Avian reproduction NOAEL: 25 - Acceptable

00261401 Laboratory rat – Acute Oral

Toxicity LD 50 : 45.6 Highly toxic Acceptable

40141311 Laboratory rat – Multigenerational reproduction study NOAEL: 2.5 - Acceptable

4.3. Incident Database Review

A review of the Ecological Incident Informa tion System (EIIS), maintained by the Agency’s Office of Pesticide Programs (OPP) indicates seve ral reported ecological incidents reported with the use of tefluthrin. Aggregated incident s and the American Bird Conservancy’s AIMS database will also be reviewed for the risk assessment.

As shown in Table 9 all reported ecological incidents with the exception of one, affected aquatic animals, as most were fish kills. The two inci dents listed at the top of the table, incidents I001081-001 and I001081-02, were clas sified as highly probable, al though there are currently no broadcast spray registrations. In cident ID I001081-001 in particular listed sediment tefluthrin environmental residues between 4 and 21 ppb in the re port. In the majority of the incidents that were listed as “Probable,” or “Highly probable, ” misuse was the most common listed reason with the pesticide being applied as a broadcast instead of the label recommended in-furrow application with the granules not be ing fully incorporated in the soil. In the majority of incidents listed, heavy rain was cited as the primary trigge r of the occurrence and when coupled with the fact that the tefluthrin granules were not fully incorporated (as required by label), it resulted in fish kill incidents.

2 Table 9. Ecological Incident Results as Listed by EIIS
Incident ID Year Legality Certainty State Taxa Affected Application method Product

I001081- 002 1994 Undetermined Highly probable IL Aquatic animals, terrestrial plants Broadcast, unincorporated Force 1.5G

I001081- 001 1994 Misuse Highly probable IL Aquatic animals, terrestrial animals,

terrestrial plants Broadcast, unincorporated Force 1.5G

I014597- 026 2003 Registered use Possible IA Terrestrial plants Granular Force 3G I005805- 002 1997 Undetermined Possible IL Aquatic animals Unknown Force 3G I005805- 1997 Undetermined Possible IN Aquatic animals Unknown Force-23 of 50- Incident ID Year Legality Certainty State Taxa Affected Application method Product

003 3G I009314- 006 1997 Undetermined Possible IL Aquatic animals N/R Force 3G I009314- 007 1997 Undetermined Possible IN Aquatic animals N/R Force 3G I007440- 001 1998 Registered use Probable IN Aquatic animals N/R Force 3G I000038- 001 1992 Misuse (accidental) Probable NE Aquatic animals Broadcast, unincorporated Force 1.5G I005395- 001 1997 Misuse (accidental) Probable IL Aquatic animals N/R Force

I000538- 001 1993 Registered use Probable IN Aquatic animals T-band Force 1.5G B0000- 501-39 1991 Misuse (accidental) Probable OH Aquatic animals Broadcast, unincorporated Force

B0000- 300-79 N/R Misuse (accidental) Probable OH Aquatic animals Broadcast, unincorporated Force 1.5G I007206- 001 1998 Registered use Probable KY Aquatic animals T-band Force 3G N/R = Not recorded

4.4. Ecosystems Potentially at Risk

The ecosystems at risk are often extensive in scop e; therefore, it may not be possible to identify specific ecosystems during the development of a nation-wide ecological risk assessment. However, in general terms, terrestrial ecosystem s potentially at risk could include the treated field and immediately adjacent areas that may recei ve 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.

Aquatic ecosystems potentially at risk include wa ter bodies adjacent to, or downstream from, the treated field and could include impounded bodies such as ponds, lake s and reservoirs, or flowing waterways such as streams or rivers. For uses in coastal areas, aquatic habitat also includes marine ecosystems, including estuaries.

5. Assessment Endpoints

Assessment endpoints are defined as “explicit expressions of the actual envir onmental value that is to be protected.” 1 Selection of the assessment endpoi nts is based on valued entities ( e.g., fish, birds), the ecosystems potentially at risk ( e.g., waterbodies, riparian vegetation, and upland habitats), the migration pa thways of tefluthrin ( e.g., runoff), and the routes by which ecological receptors are exposed to tefluthrin ( e.g., direct contact, etc. )

. Assessment endpoints for tefluthrin include direct toxic effects on the survival, reproduction, and growth of the receptors, as well as indirect e ffects, such as reduction of the prey base or modification of habitat. Each assessment endpoint requires one or more “measures of ecological

1 From U.S. EPA (1992). Framework for Ecological Risk Assessment. EPA/630/R-92/001.-24 of 50- effect,” defined as changes in the attributes of an assessment endpoint or changes in a surrogate entity or attribute in response to exposure to a pesticide. Specif ic measures of ecological effect are generally evaluated based on acute and chronic toxicity information from registrantsubmitted guideline tests that are performed on a limited number of organisms. Additional ecological effects data from the open literature will also be considered.

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.

The conceptual model for tefluthrin provides a wr itten description (risk hypothesis) and visual representation (conceptual diagram) of the predicted relationships between tefluthrin, potential routes of exposure, and the pr edicted effects for the assessmen t endpoint. A conceptual model consists of two major components: risk hypot hesis and a conceptual diagram (USEPA 1998b).

Since tefluthrin is an in-furrow, soil incorporated granule or seed treatment insecticide, ingestion of treated seed or granules plac ed in soil at the time of plan ting is the primary pathway through which exposure may occur for terrestrial wildlife (birds, mammals, reptiles, terrestrial-phase amphibians and invertebrates).

Based on its current registered uses, and the use patterns ( e.g. , granular and banded sprays) and how these exposures will only likely occur with eroded sediment rather than spray drift. Other exposure routes such as dermal contact with treated seed and soil, inhalation of pesticide vapors, and ingestion of contaminated soil a nd drinking water may be considered in the assessment. Potential pathways of exposure to aquatic animals include uptake through gills and/or dermal uptake through inte gument from offsite movement of tefluthrin to nearby water bodies. In view of high tendency for tefluthrin to persist and accumulate in soil, potential does exist for prolonged exposures to both aquatic a nd terrestrial organisms. This assessment does not consider environmental expo sure resulting from root uptak e of tefluthrin by plants, as pyrethroids are not systemic pesticides. The environmental fate and physicochemical characteristics of tefluthrin indicate that it is likely to bind to organic matter (its K ocs are high), and little translocation is expect ed. Therefore, the most cons ervative exposure estimate will result from ingestion of the treated seed rather than movement to foliage and within the plant.-25 of 50- 6.1. Risk Hypothesis

A risk hypothesis describes the predicted re lationship among the stressor, exposure, and assessment endpoint response along with the rationale for their selection. For tefluthrin, the following ecological risk hypothesis will be empl oyed for the national-level ecological risk
assessment:

The registered uses of tefluthrin on corn and se ed treatment will likely involve situations where terrestrial and aquatic animals will be exposed to the chemical and or its transformation products. Based on informati on on environmental fate, mode of action, direct toxicity, and potential indirect effects, EFED assu mes that tefluthrin has the potential to cause reduced survival, grow th, and reproduction to terrestrial and aquatic organisms as a result of the regist ered uses of the pesticide.

6.2. Conceptual Diagram

The conceptual model used to depict the poten tial ecological risk associ ated with the use of tefluthrin (the stressor) assumes that as a pesticid e, tefluthrin can adversely affect terrestrial and aquatic organisms (the receptors) if environmental concentrations exceed toxic thresholds as a result of application according to the label directions ( Figure 3 ). Ecological receptors that may potentially be exposed to te fluthrin include terrestria l and semi-aquatic wildlife ( e.g. , mammals, birds, terrestrial-phase amphibians and reptil es), terrestrial and semi-aquatic plants, and terrestrial invertebrates ( e.g. , honey bees). Additionally, given the mobility of tefluthrin, aquatic organisms ( i.e. , freshwater and estuarine/marine fi sh and invertebrates, aquatic-phase amphibians, and aquatic plants) ar e potential receptors in adjacen t water bodies through off-site transport of tefluthrin from the appli cation site through runoff and erosion.-26 of 50- Figure 3. Conceptual Diagram Depicting Po tential Risks to Terrestrial and Aquatic Animals from the Use of Tefluthrin as an insecticide

7. Analysis Plan

In order to address the risk hypot hesis, the potential for adverse effects on the environment will be estimated. The use, environmental fate, and ecological effects of tefluthrin will be characterized and integrated to assess the risks. This will be accomplished using a risk quotient (ratio of exposure concentration to effects c oncentration) approach. Although risk is often defined as the likelihood and magnitude of advers e 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 individual organisms from particular uses of tefluthrin may be estimated using the probit doseresponse slope and either the level of concern (d iscussed below) or the actual calculated risk quotient value.

Stressor

Source/ Transport Pathway

Source/ Exposure Media

Exposure Method

Receptors

Direct Effects:NonEndangered Species

Indirect Effects Food Web Dynamics Perturbed Forage or Prey Availability Habitat Alteration: impacts on nesting ability, ability to seek cover, etc. Individual Terrestrial Animals Reduced Survival Reduced Growth Reduced Reproduction Individual Terrestrial Plants Seedling Emergence

Vegetative Vigor Individual Aquatic Vertebrates and Invertebrates Reduced Survival Reduced Growth Reduced Reproduction Aquatic Plant Population Reduced Growth Rates and Biomass Terrestrial Animals (Birds, Mammals,Reptiles, Terrestrialphase Amphibians, Bees) Terrestrial Upland Plants Wetland/ Riparian

Plants Runoff and Erosion

Upland Foliage/

Soil Riparian/ Wetland Foliage/Soil Surface Water, Sediment

Direct Contact/

Root Uptake Gill/ Integument Uptake Direct Contact/

Root Uptake Ground
water

Direct Ingestion

Aquatic Invertebrates Aquatic Vertebrates

Aquatic Plants Leaching (Infiltration/ Percolation )

Terrestrial Food Residues (foliage, fruit, insects)/Soil

Dietary uptake 

## Tefluthrin-27 of 50- This analysis plan will be revisited and may be revise d depending upon the information submitted by the public in response to the openi ng of the Registration Review docket for tefluthrin.

7.1. Stressors of Concern

Tefluthrin is a synthetic pyrethr oid insecticide. Its structure ha s two rings, one phenyl ring and a cyclopropyl ring. It is not substituted in the al pha position (thus, it is a type I synthetic pyrethroid). The chemistry of tefluthrin may be di ctated by its ester moiety ; this is substantiated by the hydrolysis study, in which the chemical is stable at pH 5 and 7, but it undergoes partial hydrolysis at the highest pH of 9. The structure of the molecule has two chiral centers in the cyclopropyl group, and a double bond that could result in a total of 8 isomers. Chemically, it is the (Z)-(IR)-cis-acid and the (Z)-(1 S)-cis-acid out of eight isomeric esters. Tefluthrin is tetrafluoro substituted in the phenyl ring, and it has a trifluoromethyl group in the double bond attached to the cyc1opropyl ring. Key et al. 1997 expressed concerns over several polyfluorinated compounds, including teflut hrin's fate in the environment. In the article, it is argued that these moieties (the polyfl uorinated phenyl ring and the trifl uoromethyl group) are persistent in the environment. Examples are shown in Table 3, where the last two degradates (2,3,5,6- tetrafluoro-4-methylbenzoic acid, and 2,3,5,6-tetrafluoro-1,4-be nzenedicarboxylic acid) have structural similarities with oxons.

7.2. Measures of Exposure

In order to estimate risks of tefluthrin exposures in aquatic and terrestr ial environments, exposure modeling will be based on maximum app lication rates and methods cited in Table 1. Measures of exposure are based on aquatic and terrestria l models that predict estimated environmental concentrations (EECs) of tefluthrin. For agricu ltural uses, exposure conc entrations for aquatic ecosystems assessments will be estimated based on EFED's Tier II aquatic model PRZM/EXAMS. A graphical user interface (PES v. 5.0, November 15, 2006) developed by the EPA (http://www.epa.gov/oppefedl/mode ls/water) will be used to facilitate inputting chemical and use specific parameters into the appropriate PRZM input files (*.inp) and EXAMS chemical files.

The Pesticide Root Zone Model (PRZM v. 3.12.2, Ma y 12, 2005) field or orchard crop scenario is the basic file which describes the local or regional climatological information, soil hydrology soil characteristics, crop characteristics, and the pesticide properties necessary to determine pesticide loadings to ground or surface water. Th is basic file constitute s the first part of the "exposure scenario." It simulate s the processes in the agricult ural field, such as runoff and erosion, on a daily time step. The runoff and eros ion flux output data from PRZM are used as chemical loadings to the Exposure Anal ysis Modeling System (EXAMS v. 2.98.04.06, April 25, 2005), which simulates surface wate r, in order to predict the EECs. EECs for ecological risk assessment were determined usi ng a pond modeling scenario which de scribes a standard scenario for the EXAMS component of the modeling exercise.-28 of 50- Given the aquatic toxicity of tefluthrin and its likelihood to occur in se diment, the Agency will also consider the potential expos ures resulting from benthic/ se diment concentrations (EECs). Pore water concentrations are commonly used to predict toxicity of non-ionic substances in sediments and characterize exposure to organisms that spend time in or near sediments (Di Toro et al. 1991; US EPA 2002). PRZM/ EXAMS estimates l-in-l0-year peak and 21-day mean EECs for pore water.

The model used to predict terrestrial EECs on fo od items is the Terrestrial Residue Exposure model (T-REX). The model used to derive EECs relevant to terrestrial plants is TerrPlant. These models are parameterized using relevant review ed environmental fate data from registrant submissions and the literature. Model input values will be consistent with the most recent version of the input parameter guidance (Version 2.1; USEPA 2009).

Exposure estimates for terrestrial organisms assu med to be in the target area or in an area exposed to off-site deposition are derived using the T-REX model (version 1.4.1, 10/09/2008). Given that the registered uses ar e for seed treatment or in-furro w application, the foliar exposure portion of T-REX will not apply. The seed treatment and/or LD 50 /sq ft aspects of the model are likely to be used in the risk assessment.

In order to determine if inhalation is a potential pathway of concern for terrestrial organisms, the S creening T ool for I nhalation R isk (STIR v.1.0) was used to cal culate an upper bound estimate of exposure using tefluthrin’s va por pressure and molecular weight for vapor phase exposure as well as the maximum application rate and met hod of application for spray drift. STIR incorporates results from several toxicity studies including acute oral and inhalation rat toxicity endpoints obtained from the “six-pack” of core st udies, which are a series of six guideline studies that are submitted to the Registration Division of the Office of Pesticide Programs for technical and formulated products of a pesticide as well as the most sensitive acute oral avian toxicity endpoint. A per-acre application ra te of 2.0 lbs ai/A was assumed for tefluthrin, as the labels give application rates in lbs ai /linear foot. This assumed rate uses a 660 foot row and 330 rows per acre. Based on the results of the STIR model, inhalation e xposure alone was not determined to be a potential pathway of concern for avian or mammalian species on an acute exposure basis.

Inhalation exposure via vapor-phase of the pesticide alone does not appear to be of concern. The analysis of the inhalation route in STIR does not consider that aggregation with other exposure pathways such as dietary, dermal, or drinking wa ter may contribute to a total exposure that has a potential for effects to non-target animals. However, the Agency does consider the relative importance of other routes of expos ure in situations where data i ndicate that pesticide exposures through other routes may be potentially significan t contributors to wildlife risk (USEPA, 2004). The risk assessment will discuss the impact of consideration of other r outes of exposure that have been identified as potentially important and the degree of certainty associated with screening-level risk assessment conclusions. Detailed information about STIR v.1.0, as well as the tool, can be found on the EPA’s website
at: http://www.epa.gov/pesticides/science/models_pg.htm#terrestrial

.

The S creening I mbibition P rogram (SIP v.1.0) was used to cal culate an upper bound estimate of exposure using tefluthrin’s solubility, the most sensitive acute and chronic avian and mammalian-29 of 50- toxicity endpoints. Drinking wa ter exposure alone was determined to be a not to be a potential pathway of concern for avian or mammalian spec ies on an acute or chro nic exposure basis. Detailed information about the SIP v.1.0, as well as the tool, can be found on the EPA’s website
at http://www.epa.gov/pesticides/science/models_pg.htm#terrestrial

. EECs for terrestrial plants are derived using Te rrPlant (v.1.2.2). This m odel uses estimates of pesticides in runoff and in spray drift to calculate EECs. EECs are based upon solubility, application rate and mini mum incorporation depth.

The KABAM (K OW (based) A quatic B ioA ccumulation M odel v1.0) may be used to estimate potential bioaccumulation of hydrophobic organic pest icides in freshwater aquatic food webs and subsequent risks to mammals and birds via consumption of contaminated aquatic prey.

7.3. Measures of Effect

Ecological effects data are used as measures of direct and indirect effects to biological receptors. Effects data are obtained from registrant-submitted studies or from literature studies identified by the ECOTOX database.

The acute measures of effect used for 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 stands 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 ef fect in 50% of the test or ganisms. Endpoints for chronic measures of exposure for listed and non-liste d animals are the NOAEL/NOAEC. NOAEL stands for “No Observed-Adverse-Effect-Level” and refers to the highest tested dos e of a substance that has been reported to have no harmful (advers e) effects on test organisms. The NOAEC ( i.e.
, “No-Observed-Adverse-Effect-Concen tration”) is the highest test concentration at which none of the observed effects were statisti cally different from the control. For non-listed plants, only acute exposures are assessed ( i.e. , IC 25 for terrestrial plants and IC 50 for aquatic plants); for listed plants either the NOAEC or EC 05 is used.

Where available, sublethal 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 coloration). However, quantitative assessments of risks are limited to those endpoints that can be di rectly linked to the Agency’s assessment endpoints of impaired survival, growth and reproduction.

In the absence of taxon-specific da ta, the assessment of risk fo r direct effects to non-target organisms makes the assumption that toxicity of tefl uthrin to birds is sim ilar to terrestrial-phase amphibians and reptiles. The same assumption is ma de for fish and aquatic-phase amphibians. In the absence of data for either acute or chronic effects, the conservative assumption will be to presume that teflut hrin is toxic.-30 of 50- 7.4. Integration of Exposure and Effects

Risk characterization is the integration of e xposure and ecological effects characterization to determine the potential ecological risk from the re gistered uses of teflut hrin and the likelihood of direct and indirect effects to non-target orga nisms in aquatic and terrestrial habitats. The exposure and toxicity effects data are integrated in order to evaluate the risks of adverse ecological effects on non-target spec ies. For the assessment of teflut hrin risks, the risk quotient (RQ) method is used to compare exposure and measured toxicity values. EECs are divided by acute and chronic toxicity values . The resulting RQs are then compared to the Agency’s Levels of Concern (LOCs) (USEPA 2004). Th ese criteria are used to indicate when tefluthrin use, as directed on the labels, has the potential to cause a dverse 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 (RQ) based approach described in the risk assessment. An effo rt will be made to further qualitatively describe risk usi ng probabilistic tools that the Ag ency 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 approach es have identified risk s. Newer tools may be available to assess the routes of exposure ( e.g. TIM and SWAMP models) and will be applied as appropriate in Re gistration Review.

7.6. Endocrine Disruptor Screening Program

As required by FIFRA and FFDCA, EPA reviews num erous studies to asse ss potential adverse outcomes from exposure to chemicals. Collectiv ely, these studies includ e acute, subchronic and chronic toxicity, including asse ssments of carcinogenicity, ne urotoxicity, developmental, reproductive, and general or systemic toxicity. These studies include e ndpoints which may be susceptible to endocrine influe nce, including effects on endocri ne target organ histopathology, organ weights, estrus cyclicity, sexual maturatio n, fertility, pregnancy rates, reproductive loss, and sex ratios in offspring. For ecological hazard assessments, EPA evaluates acute tests and chronic studies that assess gr owth, developmental and reprod uctive effects in different taxonomic groups. As part of registration review decision, EPA will review these data and select the most sensitive endpoints for relevant risk assessment scenarios from the existing hazard database. However, as required by FFDCA section 408(p), tefluthrin is s ubject to the endocrine screening part of the Endocrine Di sruptor Screening Program (EDSP).

EPA has developed the EDSP to determine whet her certain substances (including pesticide active and other ingredients) may have an effect in humans or wildlife similar to an effect produced by a “naturally occurring estrogen, or ot her such endocrine effect s as the Administrator may designate.” The EDSP employs a two-tiered approach to making th e statutorily required determinations. Tier 1 consists of a battery of 11 screening assays to identify the potential of a-31 of 50- chemical substance to interact with the estrog en, androgen, 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.

Under FFDCA section 408(p), the Agency must screen all pesticide chemicals. Between October 2009 and February 2010, EPA issued test orders/data call-ins for the first group of 67 chemicals, which contains 58 pest icide active ingredients and 9 inert ingredients. Tefluthrin is not among the group of 58 pesticide active ingredient s on the initial list to be screened under the EDSP. Accordingly, as part of registration review, EPA will issu e future EDSP orders/data callins, requiring the submission of EDSP screening assays for teflut hrin. For further information on the status of the EDSP, the policie s and procedures, the lis t of 67 chemicals, future lists, the test guidelines and the Tier 1 screening battery, please visit our website: http://www.epa.gov/endo/

.

7.7. Endangered Species Assessment

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

The assessment of effects associated with the registration of tefluthrin is based on an action area. 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 indirect effects. The Agency’s approach to de fining the action area under the provisions of the Overview Document (USEPA 2004) considers the results of the risk assessment process to establish boundaries for that action area with the understandi ng that exposures below the Agency’s defined LOCs constitu te a no-effect threshold. For th e purposes of this assessment, attention will be focused on the footprint of the action ( i.e ., the area where tefl uthrin application occurs), plus all areas where offsite transport ( i.e ., spray drift, runoff, etc .) may result in potential exposure that exceeds the Agency’s LOCs. Specific m easures of ecological effect that define the action area for listed species include any direct and indi rect effects and/or potential modification of its critical habitat, including reduction in survival, growth, and reproduction as well as the full suite of sublethal effects availabl e in the effects literature. Theref ore, the action area extends to a point where environmental exposures are below any measured lethal or sublethal effect threshold for any biological entity at the whole organism, organ, tissue, a nd cellular level of organization. In situations where it is not possible to determin e the threshold for an observed effect, the action area will initially be assumed to in clude all counties where tefluthrin is used in the United States.-32 of 50- 7.8. Drinking Water Assessment

In order to bring the drinking water exposure assessment up to da te with current data, models and simulation model guidance, a new drinking water assessment will be conducted to support future human health dietary risk assessments of tefluthrin. The drinking water exposure assessment will be conducted for the maximum labeled use in support of the human health dietary risk assessment. The drinking water assessment will incorporate model estimates of tefluthrin alone in surface water and ground water including any residues that are determined to be of toxicological concern. Con centrations of tefluthrin in su rface waters (Estimated Drinking Water Concentrations, or EDWCs) will be es timated using PRZM/EXAMS (see description above) but using the Index Reservoir scenario rath er than the standard pond used for assessment of exposure in drinking water.

EFED does not anticipate conducting a new DWA.

An EDWC of tefluthrin in gr oundwater will be estimated using EFED’s Tier I aquatic model SCIGROW (Screening Concentrat ion in GROundWater, versi on 2.3; 8/8/2003). SCIGROW is a regression model used as a scr eening tool to estimate pesticid e concentrations found in ground water used as drinking water. The output of SC IGROW represents the concentrations that might be expected in shallow unconfined aquifers unde r sandy soils, which is representative of the ground water most vulnerable to pesticide contam ination likely to serve as a drinking water

source.
7.9. Environmental Monitoring Data

A query of the United States Geological Survey’s (USGS) National Water Quality Assessment Program (NAWQA) for detections of tefluthrin in surface water, groundwater, and sediments samples collected nationwide during the pe riod of 2008 to 2011 (2001-2002 for groundwater samples) are shown in Table 10.

Table 10. NAWQA Tefluthrin monitoring resu lts for surface water, groundwater, and sediments. SURFACE WATER GROUNDWATER SEDIMENTS
Form No. Samples concentrations
range (ug/l) No. Samples concentrations
range (ug/l) No. Samples concentratio
ns range (ug/kg) Tefluthrin 6525 No detection 3879 No detection 78 No detection Tefluthirn Acid benzyl ester 202 No detection 235 No detection Not analyzed for Not analyzed for

Tefluthirn Acid pentaflourobenzyl
ester 202 No detection 235 No detection Not analyzed for Not analyzed for

7.10. Water Quality

Aquatic Life Criteria and Aquatic Life Benchmarks-33 of 50- 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 identifiable effects on health and welfare which might be expected from the presen ce of pollutants in any b ody of water, including ground water. While these recommended crit eria do not, in themselves, impose any requirements, states and authorized tribes can us e them to develop water quality standards. US EPA Aquatic Life Ambient Water Quality Cr iteria document has not been published for tefluthrin (at http://www.epa.gov/waterscience/criteria/ accessed 06/08/12).

For tefluthrin, OPP has not published aquatic life benchmarks for freshwater species, based on the most sensitive species from the most recent risk assessments (refer to the following site http://www.epa.gov/oppefed1/ecorisk_ders/a quatic_life_benchmark.htm#benchmarks accessed 06/08/12).

Impaired Water Bodies Tefluthrin is not individu ally identified as a cause of impair ment for any water bodies listed as impaired 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 (accessed 06/08/12). However, the pyrethroids as a group have been identified as a cause for impairment for three water bodies in Central Vall ey, California: Del Puerto Creek, Ingram Creek Site (from confluence with Hosp ital Creek to Highway 33 cro ssing) and second Ingram Creek Site (from confluence with San Joaquin River to confluence with Hospital Creek). Additional bodies of water were evaluated and included into the list of impaired bodies of water by October 2011 (see http://www.waterboards.ca.gov/water_issu es/programs/tmdl/integrated2010.shtml

, http://www.swrcb.ca.gov/rwqc b5/water_issues/tmdl/impaire d_waters_list/303d_list.shtml and http://www.epa.gov/region9/water/tmdl/303d-pdf/ Final-DecisLtrEnclosResponsSumCA2008-10- 303d.pdf accessed 06/08/12). The 2010 303(d) list for California contains 10 additional streams due to pyrethroids in the sediments. EFED w ill include relevant information on 303(d) listings in the final ecological risk assessment as appropri ate. The Division will also evaluate whether tefluthrin was involved as one of the causes of impairment.

No Total Maximum Daily Load (TMDL) criteria ha ve been developed speci fically for tefluthrin, 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 (accessed 06/08/12). It appears that a TMDL was established for pyrethroids a nd specifically for bifenthrin, a nother synthetic pyrethroid (Rio de Santa Clara/Oxnard Drain No. 3). 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 this pesticide. To the extent 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 accessed 06/08/12 ), in order to ensure they can be us ed quantitatively or qua litatively in pesticide risk assessments.

8.0. Preliminary Identification of Data Gaps-34 of 50- Additional data needed for the risk assessment include label clarification. According to the LUIS report, tefluthrin use is not limited in number of applications. While it seems clear that tefluthrin is only applied at plan ting, verification and appropriate la bel statements will clarify this issue. Additionally, rates are prov ided only as lbs ai/lin ear foot or lbs ai/ lb of seed. Unless these rates are put onto labels as maximum mass per unit area, conservative assumptions will need to be employed at the time of the risk assessment.

8.1. Environmental Fate

The studies submitted to fulfill environmental fa te data requirements for tefluthrin are not sufficient to conduct an exposure assessment; three requirements have not been met as stipulated in 40 CFR part 158 Subpart N §158.1300 for all pestic ides with use patterns for aquatic food and nonfood applications:

 Aerobic aquatic metabolism (GLN 835.4300). There is one unacceptable study for this guideline (MRID# 47813003). An a dditional aerobic aquatic metabolism study, conducted in one sediment system should be submitted.

 Anaerobic aquatic metabolism (GLN 835.4400). There is one unacceptable study for this guideline (47813004). A new anaerobic aquatic metabolism study should be submitted. Two sediment systems are required. Submission of an acceptable anaerobic aquatic metabolism study is necessary to understand the degr adation of tefluthr in in oxygen-limiting environments.

 The environmental chemistry analytical methods and independent laboratory (ILV) portions (only) of the of the terrestrial field dissipation (835.6100) and the aquatic field dissipati on study (835.6200) rather than the full field dissipation study.

The registrant of tefluthrin submitted various aerobic and anaerobic soil and aquatic metabolism studies, and an adsorption/ desorption (batch eq uilibrium) study. The EFED evaluated all the information available and the results are summarized in Table 11

.-35 of 50- Table 11. Environmental Fate Data Requirements for Tefluthrin

Guideline Number Data Requirement MRID Study Classification 1 Are Additional Data Needed for Risk Assessment
835.4100

835.4300 Aerobic Soil Metabolis m Aerobic Aquatic Metabolism 47813003 Supplemental Unacceptable N o
Yes 2

835.4300

835.4400 Aerobic Aquatic Metabolism Anaerobic Aquatic Metabolism 47813004 Supplemental Unacceptable Yes 2

Yes 3

835.4300 Aerobic Aquatic Metabolism 47813005 Unacceptable Yes 2

835.1230 Adsorption/ Desorption (Batch Equilibrium) 47813006 Supplemental No

1 Acceptable: study satisfies guideline; S upplemental: study is scientifically so und, but does not satisfy guideline; Unacceptable: study is not scientifically sound and does not satisfy guideline.
2 An additional aerobic aquatic metabolism study, conducte d in one sediment system should be submitted.
3 A new anaerobic aquatic metabolism study should be submitted. Two sediment systems are required.

Table 12 identifies studies by MRID that offer data for each guideline requirement, as well as study classifications and whether or not furthe r data are needed in order to support risk assessment ( i.e. , whether there is a data gap).

Table 12. Summary of available environmental fate data.

Guideline Study Title MRID / ACC No. Classification Data Gap? Comments

835.2120 Hydrolysis 40141332 Acceptable No

835.2240 Photodegradation in Water 40161141 Acceptable No

835.2410 Photodegradation on Soil 40161142 Acceptable No

835.4100 Aerobic Soil Metabolism 40161143 47813003 Acceptable Supplemental No

835.4200 Anaerobic Soil Metabolism 40161143 Acceptable No

835.4300 Aerobic Aquatic Metabolism 47813004 47813005 Supplemental Unacceptable Yes An additional aerobic aqua tic metabolism study, conducted in one sediment system should be submitted.

835.4400 Anaerobic Aquatic Metabolism 47813004 Unacceptable Yes N ew anaerobic aquatic me tabolism study should be submitted. Two sediment systems are required.

835.1240, 835.1230 Mobility - Adsorption / Desorption 261402 40161144 47813006 Acceptable Acceptable Supplemental No

835.6100 Terrestrial Field Dissipation 40161145 40161147 Supplemental Acceptable No-36 of 50- Guideline Study Title MRID / ACC No. Classification Data Gap? Comments

850.1730 Fish Accumulation 40141333 Acceptable Acceptable No

8.2. Ecological Effects

The available ecological effects dataset for teflut hrin is incomplete (Tables 13-15). Acute avian toxicity data (850.2100) on a passe rine species are necessary, as is a honeybee acute contact study (850.2030). Guideline chronic exposure st udies with estuarine/marine fish and invertebrates are not available for tefluthrin and are necessary for risk assessment, as are a suite of studies specific to pyrethroids including Hyallela spp water column and multiple species sediment testing as listed below.

Given the use patterns and chemical properties of tefluthrin, aquatic plant species are expected to be exposed to tefluthrin through erosion of treated soil particle. Therefore, data on the effects (or lack thereof) to aquatic species are necessary for risk assessment.

There are no phytotoxicity data for terrestrial plan t species. Two incident reports filed with the EPA involved adverse effects to terrestrial plants, but thes e were reported to be from unincorporated broadcast applications, which are not allowed by label. It is possible that tefluthrin may exhibit phytotoxicity to certain sensitive plant species, but given the labeled application methods (seed treatment/soil treatment), exposure to terrestrial pl ants is expected to be negligible.

The available effects dataset is considered incomplete for the purposes of risk assessment. The following data gaps exist:

 Freshwater and estuarine/marine spik ed whole-sediment chronic tests , TGAI.
Test Method 100.4 (OCSPP 850.1770, in prep .); Whole sediment: ch ronic invertebrates freshwater ( Hyalella azteca ) Test Method 100.5 (OCSPP 850.1760, in prep .); Whole sediment: ch ronic invertebrates freshwater ( Chironomus dilutus ) EPA 600/R-01/020 (OCSPP 850.1780, in prep. ); Whole sediment: chro nic invertebrates marine ( Leptocheirus plumulosus ) . There are no data availabl e regarding chronic toxicity of tefluthrin to benthic organisms, an expos ure compartment of concern. For pyrethroids, spiked whole sediment chronic toxicity data for Hyalella azteca
, Chironomus dilutus , and Leptocheirus plumulosus are necessary for risk assessment.

 Aquatic Invertebrate TGAI Acute Toxicity with Hyalella azteca (Non-guideline special study). Available information indicates that the freshwater amphipod, H. azteca
, is substantially more sensitive to pyrethroids than Daphnia magna , the commonly tested freshwater invertebrate ( e.g. , Anderson et al. 2006; Maund et al. , 2002). Therefore, in order to ensure that risks to sensitive aquatic invertebrate s are appropriately quantified-37 of 50- additional acute toxicity testing of H. azteca is needed (water-onl y exposure tests, no sediment present).

 Mysid Chronic Toxicity study (GLN 850.1350)

. As discussed in the document, mysids are generally far more acutely sensitive to tefluthrin than daphnids and exposure to estuarine/marine environments is likely. In th e absence of these data, an acute-to-chronic ratio based on the daphnid data would be used; however this may result in underestimation of potential risk.

 Avian acute oral study with a passerine (GLN 850.2100). Data on the toxicity of tefluthrin to passerines are necessary for risk assessment. A registrant submission examining the potential toxicity of tefluthrin to the house sparrow ( Passer domesticus ; MRID 40161123) is being reviewed to determine if it can be us ed to fulfill this data requirement. Provisionally, the study indicates passerines as more sensitive to tefluthrin than bobwhite or mallard.

 Honey bee acute contact toxicity study (GLN 850.3020). No data are available to assess the potential toxicity of tefluthrin to beneficial invert ebrates. As an insecticide, effects to terrestrial invertebrates are exp ected, but a hazard th reshold has not been established.

 Aquatic vascular plant study (GLN 850.4400). There are no data available regarding the toxicity of tefluthrin to aquatic vascular plants. Aquatic ecosystems are likely to be exposed to tefluthrin through eros ion of treated soil pa rticles to which it is sorbed. These data are necessary for risk assessment.

 Aquatic non-vascular plant testing: one for each of 4 species (GLN 850.5400). There are no data available regarding the toxicity of tefluthrin to aquatic non-vascular plants. Aquatic ecosystems are likely to be exposed to tefluthrin through er osion of treated soil particles to which it is sorbed. These da ta are necessary for risk assessment.

 Terrestrial Plant Toxi city-Seedling Emergence (GLN 850.4100). No data on the toxicity of tefluthrin to terrestrial plants is available. Because tefluthrin may runoff the treated field to nontarget areas, effects to terrestrial plant s eedling emergence may occur. Due to the current use patterns, spray drift is not expected therefor e a vegetative vigor study is not necessary at this time.

TABLE 13. Available ecological effects data fo r terrestrial animals exposed to tefluthrin Guideline # Data Requirement Test Species MRID Study Classification More Data Needed for Risk Assessment?

850.2100

(71-1) Avian Oral LD 50 Mallard Duck 0015 6766 Acceptable No House Sparrow ( Passer domesticus ) 40161123 Under review Yes 1-38 of 50- Guideline # Data Requirement Test Species MRID Study Classification More Data Needed for Risk Assessment?

850.2200

(71-2) Avian Dietary LC 50 Mallard duck 0015 6768 Acceptable No

Bobwhite quail 00156767 Acceptable No

850.2300

(71-4) Avian Reproduction Mallard duck 4016 1124 Acceptable No

Bobwhite qua il 40161125 Acceptable No

850.3020 (141-1) Honeybee acute contact toxicity Honeybee ( Apis mellifera) No data received N/A Yes

1 data are under review; until the review is complete EFED cannot be certain the data are sufficient for risk
assessment.

TABLE 14. Available ecological effects data for aquatic animals exposed to tefluthrin.

Guideline # Data Requirement Test Species MRID Study Classification More Data Needed for Risk Assessment?
850.1075

(72-1) Freshwater Fish LC 50 Rainbow trout 0 0156769 Acceptable No Bluegill sunfish 0 0156770 Acceptable

850.1010

(72-2) Freshwater Invertebrate Acute LC 50 Water flea ( Daphnia
magna ) 40161132 Acceptable No

850.1075 (72-3a) Estuarine/Marine Fish Acute LC 50 Sheepshead minnow 40161137 Acceptable No

850.1300

(72-4) Freshwater Invertebrate Life Cycle Water flea ( Daphnia magna) 41229501 Acceptable No

850.1055

(72-3) Marine/Estuarine Bivalve Acute Toxicity Test Pacific oyster ( Crassotrea gigas) 40161135 Acceptable No

850.1053

(72-4) Estuarine/Marine Invertebrate Acute LC 50 Mysid shrimp 40161136 Acceptable No

850.1350

(72-4) Estuarine/Marine Invertebrate Life Cycle Mysid shrimp No data received N/A Yes 1

850.1400

(72-4) Freshwater Fish Early Life Stage Fathead minnow 4170 5101 Acceptable No

850.1400

(72-4) Estuarine/Marine Fish Early Life Stage (1) -- No data received N/A No

1 fish data are insufficient for an acute-to-chronic ratio (ACR) to be reliably calculated.

TABLE 15. Available ecological effects da ta for plants exposed to tefluthrin.

Guideline # Data Requirement Test Species MRID Study Classification More Data Needed for Risk Assessment? 850.4110 (121-1) (123-1) Seedling Emergence Multiple species No data received N/A Yes-39 of 50- 850.4150 (121-1) (123-1) Vegetative Vigor Multiple species No data received N/A No

850.4400 (122-2) (123-2) Aquatic Vascular Plant Toxicity Duckweed ( Lemna gibba ) No data received N/A Yes

850.5400 (122-2) (123-2) Aquatic Nonvascular Plant Toxicity Multiple species No data received N/A Yes

9. References

Open Literature Citations

Armitage, J. M., & Gobas, F. A P. e. 2007. A terrestrial food-chain bioaccumulation model for POPs. Environmental Science and Technology, 41,4019-4025.

Di Toro, DM, CS Zarba, DJ Hansen, WJ Be rry, RC Swartz, CE Cowan, SP Pavlou, HE Allen, NA Thomas and PR Paquin. 1991. Technical basis fo r establishing sediment quality criteria for nonionic organic chemicals using equilibrium partitioning. Environ. Toxicol. Chem. 10:1541- 1583.

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

Gobas, F. A P. e., Kelly, B. e., & Arnot, J. A 2003. Quantitative structure activity t:elationships for predicting the bioaccumulation of POPs in terrestrial food-webs. QSAR Comb. Sci, 22, 329-336

Hoerger, F., and E.E. Kenaga. 1972. Pesticide residues on plants: Correlation of representative data as a basis for estimation of thei r magnitude in the environment. In F. Coulston and F. Korte, eds ., Environmental Quality and Safety: Chemistry, Toxicology, and Technology, Georg Thieme Publ, Stuttgart, West Germany, pp. 9-28.

Key, B., R Howell and C. Criddle. 1997. Fluorinated Organics in the Biosphere. Environ. Sci. & Technol. 31(9), 1997, pp. 2445-2454.

U.S. Fish and Wildlife Service (USFWS) and Na tional Marine Fisheries Service (NMFS). 1998. Endangered Species Consultation Handbook: Procedures for Conducting Consultation and Conference Activities Under Section 7 of the Endangered Sp ecies Act. Final Draft. March 1998.

USEPA. 2007. Bradbury, S. Guidance for Tier I Estimation of Aqueous Pesticide Concentrations in Rice Paddies. U.S. E nvironmental Protection Agency, Office of Prevention, Pesticides and Toxic Substance, Environmental Fate and Effects Division. Internal Memorandum. May 8, 2007.-40 of 50- USEPA. 2004. Overview of the Ecological Risk Assessment Process in th e Office of Pesticide Programs. U.S. Environmental Protection Ag ency, Office of Prevention, Pesticides and Toxic Substances, Office of Pesticide Programs, Washington DC. January 23, 2004.

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

USDA, 2006-2010. NASS Crop Reporting Districts. Online: http://www.ers.usda.gov/briefing/arms/r esourceregions/resourceregions.htm#nass

. Willis, G.H. and L.L. McDowell. 1987. Pesticide Persistence on Foliage in Reviews of Environmental Contaminati on and Toxicology. 100:23-73.-41 of 50- 

## Submitted Fate Studies

161-1 Hydrolysis

MRID Citation Reference

156762 Hall, J.; Leahey, J. (1983) PP993: Hy drolysis in Sterile Distilled Water at 3 Different pH's: Report Series RJ 0335B . Unpublished study prepared by ICI Plant Protection Div. 18 p.
40141332 Steward, J.; Leahey, J. (1986) Tefluthr in: Hydrolysis at pH5, 7 and 9 in Sterile Aqueous Solutions: Laboratory Project ID: RJ0512B. Unpublished study prepared by ICI Plant Protection Div., J ealott's Hill Research Station. 30 p.



### 161-2 Photodegradation-water

MRID Citation Reference

156763 Woods, T.; Leahey, J. (1984) PP993:- Photolysis in Water at pH7: Report Series RJ 0346B. Unpublished study pr epared by ICI Plant Protection Div. 28 p. 40161141 Amos, R.; Leahey, J. (1987) Tefluthrin: Photodegradation in Sterile Water at pH7: Laboratory Project ID: RJ0562B. Unpublished study prepared by ICI Plant Protection Div., Jealott's H ill Research Station. 64 p.



### 161-3 Photodegradation-soil

MRID Citation Reference

40161142 Amos, R.; Leahey, J. (1987) Tefl uthrin: Photolysis on a Soil Sur- face: Laboratory Project ID: RJ0563B. Unpublis hed study pre- pared by ICI Plant Protection Div., Jealott's Hill Research Sta- tion. 61 p.
40161148 Hill, I. (1987) Tefluthrin: Comparison of Results from Soil Degra- dation and Dissipation Studies: Laboratory Project ID: M4418B. Unpublished study prepared by ICI Plant Protection Div., Jea- lott's Hill Research Station. 33 p.



### 162-1 Aerobic soil metabolism

MRID Citation Reference

40161143 Pluckrose, J.; Bewick, D. (1986) Te fluthrin: Further Studies on Degradation in Soil: Laboratory Project ID: RJ0525B. U npub- lished study prepared by ICI-42 of 50- Plant Protection Div., Jealott's H ill Research Station. 43 p.
47813003 Bewick, D.; Weissler, M. (1985) Tefluthrin: PP993 - Degradation in Soil: Final Report. Project Number: RJ/0423B, T000311/09. Unpublished study prepared by Jealott's Hill Research Station. 54 p.

Not provided Bharty, H., D.W. Bewick, and R.D. White PP563 and PP321 Degradation in Soil



### 162-2 Anaerobic soil metabolism

MRID Citation Reference

40161143 Pluckrose, J.; Bewick, D. (1986) Te fluthrin: Further Studies on Degradation in Soil: Laboratory Project ID: RJ0525B. U npub- lished study prepared by ICI Plant Protection Div., Jealott's H ill Research Station. 43 p.



### 162-3 Anaerobic aquatic metab.

MRID Citation Reference

47813004 Dean, G. (1995) (Carbon 14) Tefluthrin: Degradability and Fate in a WaterSediment Under Aerobic, Anaerobic an d Sterile Conditions: Final Report. Project Number: ISN/3321/950441, T000312/09. Unpublished study prepared by Huntingdon Research Center. 121 p.



### 162-4 Aerobic aquatic metab.

MRID Citation Reference

47813003 Bewick, D.; Weissler, M. (1985) Tefluthrin: PP993 - Degradation in Soil: Final Report. Project Number: RJ/0423B, T000311/09. Unpublished study prepared by Jealott's Hill Research Station. 54 p.
47813004 Dean, G. (1995) (Carbon 14) Tefluthrin: Degradability and Fate in a WaterSediment Under Aerobic, Anaerobic an d Sterile Conditions: Final Report. Project Number: ISN/3321/950441, T000312/09. Unpublished study prepared by Huntingdon Research Center. 121 p.
47813005 Vonk, J. (1990) Tefluthrin: Biodegradation of Tefluthrin in a Static Water/Sediment System: Final Report. Project Number: R/89/382A, T000313/09. Unpublished study prepared by TNO. 46 p.



### 163-1 Leach/adsorp/desorption

MRID Citation Reference-43 of 50- 156765 Stevens, J.; Bewick, D. (1985) PP993: Leaching of PP993 and Its Degradation Products in Soil Columns: Report Series RJ 0428B. Unpublished study prepared by ICI Plant Protection Div. 17 p.
40161144 Pluckrose, J.; Vickers, J.; Bewick, D. (1987) Tefluthrin: Adsorp- tion and Desorption in Soil: Laboratory Project ID: RJ0542B. Unpublished study prepared by ICI Plant Protection Div., Jea- lott's Hill Research Station. 31 p. 42201601 Travis, K.; Wadley, A. (1992) The Distribution of Tefluthrin Between the Adsorbed and Dissolved Phase in Runoff. Unpublished st udy prepared by ICI Agrochemicals, Jeallott's H ill Research Station. 29 p.
42201602 Brusseau, M.; Rao, P. (1989) Sorption nonideality during organic contaminant transport in porous media. Critical Reviews in Environmental Control 19(1): 33-99.
42201603 DiToro, D. (1985) A particle interaction model of reversible organic chemical sorption. Chemosphere 14(10):1503-1538.
42201606 Wallach, R.; Jury, W.; Spencer, W. (1988) Transfer of chemicals from soil solution to surface runoff: A diffusion- based soil model. Soil Science Soc AM. J., 52(1988):612-618.
42201608 Ahuja, L. (1990) Modeling soluble chemical transfer to runoff with rainfall impact as a diffusion process. Soil Science Soc. AM. J., 54(1990):312-321.
42201609 Ahuja, L. (1986) Characterization and modeling of chemical transfer to runoff. Adv. Soil Scie nce 4(1986):149-188.
42201610 Hillel, D. (1992) Introduction to Soil Physics: Force 1.5G. Unpublished study prepared by ICI Americas Inc. 5 p.
42201611 Hartley, ?. (1980) Solubility, parti tion and adsorption. Physical Properties of Pesticides Behavior, Academic Press pp. 11-109.
47813006 Dean, G. (2001) Tefluthrin: Adsorption and Desorption Properties in Four Soils: Final Report. Project Number: GZR/001/013274, T000310/09. Unpublished study prepared by H untingdon Research Center. 92 p.



### 164-1 Terrestrial field dissipation

MRID Citation Reference

40161145 Fitzpatrick, R. (1987) Tefluthrin: Di ssipation in U.S. Soils: Labo- ratory Project ID: TMU3086/B. Unpublished study prepared by ICI Americas Inc. 100 p.
40161146 Murnane, D.; Sapiets, A. (1987) Tefluthrin: Soil Dissipation Study (USA, 1986): Laboratory Project ID: RJ0570B. Unpublished study prepared by ICI Plant Protection Div., Jealott's H ill Research Station. 77 p.
40161147 Hill, I.; Bewick, D.; Bartlett, D.; et al. (1987) Tefluthrin: Fate of Radiolabled Material in Soil under Field Conditio ns: Labo- ratory Project ID: RJ0546B. Unpublished study prepared by ICI Plant Protection Div., Jealott's Hill Research Station in co- operation with Huntingdon Research Center Ltd. 173-44 of 50- p. 40161148 Hill, I. (1987) Tefluthrin: Comparison of Results from Soil Degra- dation and Dissipation Studies: Laboratory Project ID: M4418B. Unpublished study prepared by ICI Plant Protection Div., Jea- lott's Hill Research Station. 33 p.
41022601 Murnane, D.; Yearsdon, C.; Sapiets, A. (1988) Tefluthrin: Soil Dissipation Study (Canada, 1986-87): Laboratory Project ID: RJ0616B. Unpublished study prepared by ICI Amer icas Inc., Jealott's Hill Re search Station. 94 p.
41392201 Hill, I.; Hadfield, S.; Hendley, P.; et al. (1990) ICI Force 1989 Run-off Study Site MS04: An Assessment of its Relevance as a Conventional-Tillage Corn Growing Site. Unpublished study prepared by ICI Agrochemicals. 38 p.
43862202 Killingsworth, D. (1995) Tefluthr in: Soil/Water Release Study from Force Granular Formulation: Lab Project Nu mber: TEFL-93-OT-02: RR 94-063B. Unpublished study prepared by Zeneca Ag Products. 98 p.
43862203 Nett, M. (1995) A Comparison of Agricultural Runoff Between (inert ingredients) Force 1.5G Insecticide Formulations Using Simulated Rainfall on Small Plots: Lab Project Number: 09 93-92-RO-01: RR 94-030B. Unpublished study prepared by Zeneca Ag Products and PTRL East, Inc. 94 p.
43862204 Nett, M. (1995) Anal ytical Report of the 1992 Small Scale Simulated Runoff Comparision of Force 1.5G (inert ingredient) Formulations: Lab Project Number: RR 94-031B: 0993-92-RO-01: RR 90-373. Unpublished study prepared by Zeneca Ag Products and PTRL East, Inc. 76 p.
43862205 Coody, P.; White, J. (1995) A Comparison of Agricultural Runoff Between (inert ingredients) Force 1.5G Insecticide Formulations Using Simulated Rainfall on Small Plots and A Study of the Agricultural Runoff of Dyfonate II 20 G Corn Insecticide Using Simulated Rainfall on Small Plots: Lab Project Number: 0993-92-RO-01: 99KY-92-8070: 716. Unpublished study prepared by Zeneca Ag Products and PTRL East, Inc. 105 p.
43862206 Wadley, A.; Travis, K. (1995) Tefluthrin: Modeling Runoff and Aquatic Fate at Tier 2: Lab Project Number: TMJ3541B. Unpublished study prepared by Zeneca Agrochemicals. 49 p.
46766710 Hendley, P.; Nett, M. (2006) Teflut hrin: A Comparison of Agricultural Runoff Between Force 3G Granule and Microencapsulated Force 30CS Formulations Using Simulated Rainfall on Small Plots: Final Report. Project Number: T014248/05, 1273, TEFL/99/RO /01. Unpublished study prepared by Syngenta Crop Protection, Inc., PTRL East, Inc. and Zeneca Ag Products Inc. 292 p.



### 165-4 Bioaccumulation in fish

MRID Citation Reference

40141330 See 40141333 Hamer, M.; Farrelly, E.; French, D.; et al. (1987) Tefluthrin: Accumulation in Bluegill Sunfish in a Flow-through System: Labo- ratory Project ID: RJ0521B. Unpublished study prepared by ICI Plant Protection Div., Jealott's Hill Research Station. 50 p.
40141333 2070748 Hamer, M.; Farrelly, E.; French, D.; et al. (1987) Tefluthrin: Accumulation in-45 of 50- Bluegill Sunfish in a Flow-through System: Labo- ratory Project ID: RJ0521b. Unpublished study prepared by ICI Plant Protection Div., Jealott's Hill Research Station. 50 p.



## Submitted Effects Studies

71-1 Avian Singl e Dose Oral Toxicity

MRID Citation Reference

156766 Roberts, N.; Fairley, C.; Ander son, A.; et al. (1985) The Acute Oral Toxicity of PP993 to the Mallard Duck: HRC Report No. ISN 4BT/84939. Unpublished study prepared by Hunt ingdon Research Centre. 40 p.
40161123 Grimes, J.; Jaber, M. (1986) PP993 Technical: An Acute Oral Toxi- city Study with the House Sparrow: Project No. 123-137. Unpub- lished study prepared by Wildlife International Ltd. 23 p.

Accession No. 261402. Dawe, I.S. and S.F. Johnson (1985) The Acute Oral Toxicity of PP993 to the Mallard Duck. Prepared by: Huntington Research Centre, Cambridgeshire, England. Submitted by Imperial Chemical Industries, Cheshire, England. Report No. CTL/C1333. Accession No. 261402.



### 71-2 Avia n Dietary Toxicity

MRID Citation Reference

156767 Roberts, N.; Fairley, C.; Ander son, A.; et al. (1985) The Subacute Dietary Toxicity of PP993 to the Mallard Duck: HRC Report No. ISN 6BT/841211. Unpublished study prep ared by Huntingdon Reaearch Centre. 36 p.
156768 Roberts, N.; Fairley, C.; Ander son, A.; et al. (1985) The Subacute Dietary Toxicity of PP 993 to the Bobwhite Quail: HRC Report No. ISN 9BT/841205. Unpublished study prep ared by Huntingdon Research Centre. 39 p.



### 71-4 Avian Reproduction

MRID Citation Reference

40161124 Roberts, N.; Fairley, C.; Anderson, A.; et al. (1987) The Effect of Dietary Inclusion of PP993 on Reproduction in the Mallard Duck: HRC Report No. ISN 104BT/861241. Unpublished study prepared by Huntingdon Research Center Ltd. 152 p.-46 of 50- 40161125 Roberts, N.; Fairley, C.; Anderson, A.; et al. (1987) The Effect of Dietary Inclusion of PP993 on Reproduction in the Bobwhite Quail: HRC Report No. ISN 103BT/861240. Unpublished study pre- pared by Huntingdon Research Center Ltd. 227 p.



### 72-1 Acute Toxicity to Freshwater Fish

MRID Citation Reference

156769 Hill, R. (1985) PP993: Determinat ion of Acute Toxicity to Rainbow Trout (Salmo gairdneri): BL/B/2410. Unp ublished study prepared by ICI Brixham Laboratory. 19 p.
156770 Hill, R. (1985) PP993: Determinat ion of Acute Toxicity to Bluegill Sunfish (Lepomis macrochirus): BL/B/2411. Unpublished study prepared by ICI Brixham Laboratory. 19 p.
40161126 Hill, R. (1987) Tefluthrin 1.5% Milled Formulation: Determination of Acute Toxicity to Rainbow Trout (Salmo gairdneri): Laboratory Project ID: BL/B/2957. Unpublished study prepared by ICI Brix- ham Laboratory. 16 p.
40161127 Hill, R. (1987) Tefluthrin 1.5% Milled Formulation: Determination of Acute Toxicity to Bluegill Sunfish ( Lepomis macrochirus): La- boratory Project ID: BL/B/2958. Unpublished study prepared by ICI Brixham Laboratory. 15 p.
40161128 Farrelly, E.; Vincent, J.; Hamer, M.; et al. (1985) PP993: Toxicity to Bluegill Sunfish and 3 Aquatic Inve rtebrates Daphni a, Asellus and Mayfly nymphs in the Presence/Abse nce of Soil: Laboratory Project ID: RJ0417B. Unpublished study prepared by ICI Plant Protection Div., Jealott's Hill Research Station. 22 p.
43035102 Farrelly, E.; Vincent, J.; Hamer, M.; et al. (1985) Supplemental Information: PP993 (Tefluthrin): Toxicity to Bluegill Sunfish and 3 Aquatic Invertebrates Daphnia, As ellus and Mayfly Nymphs in the Presence/Absence of Soil: Lab Project Number: RJ0417B. Unpublished study prepared by Jealotts H ill Research Stat ion. 21 p.
43862207 Sankey, S.; Holland, M.; Caunter, J. (1992) Tefluthrin: Acute Toxicity to Bluegill Sunfish (Lepomis macrochirus) of a 15g/kg GR Formulation: Lab Project Number: FT14/92: BL4584/B: W239/B. Unpublished study prepared by Zeneca Ltd. 23 p.
43862208 Sankey, S.; Caunter, J.; Penwell, A. (1992) Tefluthrin: Acute Toxicity to Rainbow Trout (Oncorhynchus mykiss ) of a 15g/kg GR Formulation: Lab Project Number: FT13/92: BL4549/B: W239/A. Unpublished study prepared by Zeneca Ltd. 24 p.-47 of 50- 

### 72-2 Acute Toxicity to Freshwater Invertebrates

MRID Citation Reference

40161128 Farrelly, E.; Vincent, J.; Hamer, M .; et al. (1985) PP993: Toxicity to Bluegill Sunfish and 3 Aquatic Inve rtebrates Daphni a, Asellus and Mayfly nymphs in the Presence/Abse nce of Soil: Laboratory Project ID: RJ0417B. Unpublished study prepared by ICI Plant Protection Div., Jealott's Hill Research Station. 22 p.
40161132 Farrelly, E.; Hamer, M.; Hill, I. ( 1987) Tefluthrin: An Investiga- tion of the Toxicity of Granular Formulation: GFU 271 to First Instar Daphnia magna: Laboratory Project ID: RJ0531B. Unpub- lished study prepared by ICI Plant Protection Div., Jealo tt's Hill Research Station. 21 p.

43035103 DER not located Farrelly, E.; Hamer, M. (1992) Teflut hrin: Acute Toxicity of a 1.5% w/w Granular Formulation (GFU524) to First Instar Daphnia Magna: Lab Project Number: 92JH083: RJ1214B. Unpublished study prepared by Jealotts Hill Research Station. 17 p.

43035104 DER not located Farrelly, E.; Hamer, M. (1992) Teflut hrin: Acute Toxicity of a 1.5% w/w Granular Formulation (WF1535) to First Instar Daphnia Magna: Lab Project Number: 92JH084: RJ1215B. Unpublished study prepared by Jealotts Hill Research Station. 17 p.

156771 DER not located Farrelly, E.; Hamer, M.; Hill, I. ( 1984) PP993:- Toxicity to First Instar Daphnia magna: Report Series RJ 0377B. Unpublished study prepared by ICI Plant Protection Div. 14 p.



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

MRID Citation Reference

40161135 Thompson, R. (1986) PP993: Determination of the Acute Toxicity to Larvae of the Pacific Oyster (Crassos trea gigas): Laboratory Project ID: BL/B/2855. Unpublished study prepared by ICI Brix- ham Laboratory. 17 p. 40161136 Thompson, R. (1986) Tefluthrin: Determination of Acute Toxicity to Mysid Shrimps (Mysidopsis bahia): Laboratory Project ID: BL/B/ 2967. Unpublished study prepared by ICI Brixham Laboratory. 17 p.
40161137 Hill, R. (1986) Tefluthrin: Dete rmination of Acute Toxicity to Sheepshead Minnow (Cyprinodon variegatus): Laboratory Project ID: BL/B/2916. Unpublished study prepared by ICI Brixham Labo- ratory. 15 p.-48 of 50- 

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

MRID Citation Reference

40161138 Hamer, M.; Farrelly, E.; Hill, I. (1987) Tefluthrin: 21 Day Daphnia magna Life-cycle Study: Laboratory Project ID: RJ0530B. Unpub- lished study prepared by ICI Plant Protection Div., Jealott's Hill Research Station. 32 p.41229501 Farrelly, E.; Hamer, M.; Hill, I. (1989) Tefluthrin: Daphnia magna Lifecycle Study Using 1 Flow-through System: Rept. No. RJ0769B. Unpublished study prepared by ICI Agrochemicals, Jealotts Hill Research Station. 26 p.



### 72-5 Life cycle fish

MRID Citation Reference

41705101 Tapp, J; Maddock, B.; Gillings, E. (1990) Tefluthrin (Force ICIA099 3): Determination of Chronic Toxicity to Fathead Minnow (Pime- phales promelas) Full Lifecycle: Lab Project Number: S001/A (FT 83/88): BL3737/B. Unpublished study prepar ed by Imperial Chemi- cal Industries PLC. 266 p.
41739800 ICI Agriculture Products (1990) Submission of Toxicity Data In Response to the EEB Review of the La mbda-cyhalothrin fish life- cycle Study. Transmittal of 1 Study.-49 of 50- 

## Appendix A Justification for Studies Requested

Guideline Number: 835.4300 Study Title : Aerobic Aquatic Metabolism Study Substance: tefluthrin Rationale for Requiring the Data

EPA has a limited understanding of how tefl uthrin behaves in the environment once applied. Depending on how quickly and to what extent the compound degrades, tefluthrin may or may not contribute to an tibiotic resistance in human pathogens. Because tefluthrin degradation in water in aerobic conditions is not well understood, EPA is requiring confirmatory data. Practical Utility of the Data

How will the data be used? Aerobic aquatic metabolism data will facilita te a better understanding of tefluthrin under aqueous conditions. If data indicate that degr adation occurs rapidly in water, then EPA could potentially determine that tefluthrin e, when exposed to aerobic water, would not likely contribute to antibiotic resistance in human pathogens. If data indicate that degradation occurs slowly, then EPA could not necessarily conclude that the risk of tefluthrin contributi ng to antibiotic re sistance in human pathogens is negligible and further study and/or restric tions would be required.

How could the data change the Agency’s decision, or impact the Agency’s future decision-making ? If data indicate that tefluthrin degrades slowly in water in aerobic conditions, then antibiotic resistance may be a publ ic health risk of concern a nd additional use precautions and/or restrictions may be necessary.

Study Title: Anaerobic Aquatic Metabolism Guideline Number: 835.4400 Study Substance: tefluthrin Rationale for Requiring the Data Acceptable data have not been provid ed to quantify the metabolism of tefluthrin under anaerobic aquatic conditions; supplemental data has been submitted. According to 40 CFR Part 158 Subpart N, July, 2009 (data requirements for pesticides) anaerobic aquatic metabolism in two water:sediment systems are required for pesticides with terrestrial or aquatic food and nonfood uses. Since tefluthrin uses are classified as te rrestrial, anaerobic aquatic
metabolism data for tefluthrin should be submitted to fulf ill OCSPP Guideline 835.4400.

Practical Utility of the Data-50 of 50- How will the data be used? Currently there are no accept able anaerobic aquatic metabolism studies that track the formation and decline of tefluthrin and its degradates. The submitted data will be used to characterize and quantify the environmental fate of tefluthrin and its degradates in aquatic environments. For quantitative exposure estimation, these data will be used to confirm the conceptual model of tefluthrin fate and transport in aquatic environments.

How could the data impact the Ag ency’s future decision-making? Without these required data, the fate of tefluthrin cannot be fully characterized and exposure to potentially toxic degradates cannot be quantified. The persistence of as ulam and its degradates to which terrestrial and aquatic organisms will be exposed to is uncerta in. In the absence of acceptable data , conservative assumptions will be made regarding the potential for formation of tefluthrin degradates. Therefore, potential for risk to aquatic organisms may be overestimated and the use of tefluthrin might need to be restricted in areas where endangered species could be exposed. The lack of these data will limit the flexib ility the Agency and registrants have in complying with the Endangered Species Act and could result in use restrictions for tefluthrin which are unnecessarily severe.

Guideline Number: Non-guideline special study Study Title: Aquatic Invertebrate Acute Toxicity ( Hyalella ) Rationale for Requiring the Data

Available information indicates that the freshwater amphipod, Hyalella azteca , is substantially more sensit ive to pyrethroids than Daphnia magna , the commonly tested freshwater invertebrate (e .g., Anderson et al. 2006; Maund et al., 2002). Information on the acute toxicity of tefluthrin to H. azteca was not identified in th is problem formulation. Therefore, in order to ensure that risk to sensitive aquatic inverteb rates are appropriately quantified, additional acute toxicity testing of H. azteca is needed (water column exposure, not sediment-spiked)

. 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 us ed to determine the lik elihood that acute risks can potentially impact aquatic communities, either by direct effects on invertebrates or by indirect effects by reducing the food source for their predators ( e.g. , fish). 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 toxicity concerns with tefluthrin.

How could the data impact the Agency’s future decision-making? If future risk assessments are performed w ithout these data, the Agency would have to account for the potential increased sensitivity of Hyalella to bifenthrin using other means which may include using an extrapolation factor based on sensitivity differences with other pyrethroids. Since this extrapolation f actor would involve uncer tainty, it is likely that a conservative factor would be applied. This may impinge on the Agency’s flexibility in coming into compliance with the Endange red Species Act and could result in use restrictions for bifenthrin wh ich are unnecessarily severe.