### UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON D.C., 20460

OFFICE OF CHEMICAL SAFETY
AND POLLUTION PREVENTION



### MEMORANDUM PC Code: 109709

DP Barcodes: D403437 April16, 2013

Subject:

To:

From:

Reviewed By:

Through: Registration Review: Preliminary Ecological Risk Assessment and Endangered Species Effects Determination for Metofluthrin

Veronica Dutch, Chemical Review Manager

Risk Management and Implementation Branch V
Pesticide Re-evaluation Division (7508P)

Melissa Panger, Ph.D., Senior Scientist

# ~ '(

# /I~/IJ James Wolf, Ph.D., Environmental Scientist

### <L~-,. 

# f<lJ.1

Environmental Risk Branch III 

# t?..,.,..-.......,.

Environmental Fate and Effects Division**(7507P ~** 



### Rosanna Louie-Juzwiak, RAPL {))_-

# ~ Environmental Risk Branch Ill

## v~ Environmental Fate and Effects Division (7507P )

Dana Spatz, Branch Chief
Environmental Risk BrancfN:H:::S..,.l**"-.7""--.,..._00:::::N~** 

### Environmental Fate and Effects Division (7507P )

The Environmental Fate and Effects Division (EFED) has completed the preliminary ecological

risk assessment and endangered species effects determination for the pyrethroid insecticide

metofluthrin (first registered in 2006). For the currently registered uses 

### (i.e., deck strips, personal fans, and candles), metofluthrin is released into the air as a vapor through passive dissipation, heat-driven or fan-driven evaporation. For these uses, the active ingredient is initially present in the atmosphere in a volatile form but is expected to dissipate rapidly through a combination of degradation and dilution by the large volume of air into which it is released.

Based on the available data, the currently registered use patterns for metofluthrin, and

conservative assumptions regarding exposure, none ofthe EPA's Levels of Concern are exceeded for fish (and, thus, aquatic-phase amphibians), aquatic invertebrates, birds (and, thus, reptiles and terrestrial-phase amphibians), or mammals. Furthermore, there are no known ecological incidents reported for metofluthrin.

Because metofluthrin is used as an insect repellent and has potential insecticidal properties, it is

assumed that any terrestrial invertebrate 

### (e.g., listed flying terrestrial invertebrate species) that is exposed to metofluthrin via ambient exposure 

### (i.e., flying through the metofluthrin released by

the deck strip, fan or candle) has the potential to be affected. Given the relatively limited area of

effect around the metofluthrin dispensing devices (up to 5 m), the likely setting ofuse 

### (i.e., in



### 1

### 2

backyards and other areas around people), the short half-life of metofluthrin in air (ranging from 1.7 to 1.9 hours)

, the fact that non-target invertebrates would be exposed to the metofluthrin only by chance [unlike the target species ( i.e

., mosquitoes, that track humans)], the probability of impacting endangered invertebrates is low. There are currently no data available to assess the potential risk to terrestrial or aquatic plants from the registered metofluthrin uses. Risks to plants, however, are not expected due to the low exposure potential. Therefore, there is no reasonable expectation of effects to federally listed threatened or endangered terrestrial invertebrate, aquatic plant, or terrestrial plant species from use of currently registered metofluthrin products.

Due to a combination of low exposure and relative insensitivity to the active ingredient (for

man y taxa), risks to non-target organisms are not expected. Because direct adverse effects are not expected for birds, reptiles, amphibians, mammals, fish, or aquatic invertebrates, and there is

no re asonable expectation of effects to plants or terrestrial invertebrates, the EPA makes a No
Ef fects (NE) determination for all Federally-listed threatened/endangered species and the currently registered uses of metofluthrin. This determination was supported by the the Office of

P esticide Program’s Science Policy Council/Risk Management Forum De Minimis Subgroup (USEPA, 2013). EPA also has determined that for the currently registered uses of metofluthrin

n o Habitat Modification is likely for designated critical habitats.

### 3 REGISTRATION REVIEW

Preliminary Ecological Risk Assessment and Endangered Species Effects Determination for:

Metofluthrin

(CAS Reg. No. 240494-70-6; USEPA PC # 109709)

2,3,5,6

- tetrafluoro

- 4

- (methoxymethyl)benzyl( E

, Z )

- (1 R ,3 R )

- 2,2

- dimethyl

- 3

- (prop

- 1

- enyl)cyclopropanecarboxylate



### Prepared by: 

### Melissa Panger, Ph

. D

. , Senior Scientist James Wolf, Ph.D., Environmental Scientist

Reviewed by:


### Rosanna Louie

- Juzwiak, RAPL 

### Dana Spatz, Branch Chief

U. S. Environmental Protection Agency Office of Pesticide Programs
Environmental Fate and Effects Division
Environmental Risk Branch 3 1200 Pennsylvania Ave., NW
Mail Code 7507P Washington, DC 20460

April 16, 2013

### 4 TABLE OF CONTENTS

1. Problem Formulation ....................................................................................... 5

Na ture of Regulatory Action ....................................................................................................... 5
Previous Assessments ................................................................................................................. 5 Ecological Risk Assessments ...................................................................................... 5

Dr inking Water Exposure Assessment ....................................................................... 6
Stressor Source and Distribution ................................................................................................ 6

P esticidal Mechanism of Action ................................................................................. 6

Ove rview of Pesticide Use and Usage ........................................................................ 7 Environmental Fate and Transport ............................................................................................. 7
Environme ntal Fate Properties .................................................................................. 10

Ec ological Effects ..................................................................................................................... 11

Ec ological Incidents .................................................................................................. 12 Characteristics of Ecosystems Potentially at Risk .................................................... 12

Asse ssment Endpoints .............................................................................................. 12

C onceptual Model ..................................................................................................... 13 Analysis Plan ............................................................................................................................ 16

Mea sures of Exposure ............................................................................................... 16

Mea sures of Effect .................................................................................................... 18 Integration of Exposure and Effects.......................................................................... 18
Enda ngered Species Assessments ............................................................................. 19

2. RISK CHARACTERIZATION..................................................................... 19
RISK ESTIMATION ................................................................................................................ 19

RISK DESCRIPTION .............................................................................................................. 22

ENDANGERED SPECIES ASSESSMENT ............................................................................ 23
References ................................................................................................................................. 23

### 5

1. PROBLEM FORMULATION

Nature of Regulatory Action

As part of the implementation of the Registration Review program pursuant to Section 3(g) of FIFRA, the Agency is evaluating all current and active registrations for metofluthrin (2,3,5,6

- tetrafluoro-4-(methoxymethyl)benzyl( E

, Z )- (1 R ,3 R )-2,2-dimethyl-3-(prop-1-

e nyl)cyclopropanecarboxylate) to determine whether it continues to meet the FIFRA standard for

re gistration. The structure of this risk assessment is based on guidance contained in U.S. EPA’s
Guida nce for Ecological Risk Assessment (USEPA, 1998a ).

Previous Assessments

Ecological Risk Assessments

Metofluthrin was first registered in 2006 (the current registrants are S.C. Johnson & Sons, Inc., and Sumitomo Chemical Company, LTD). As part of the initial registration, the potential ecological exposures and risks associated with both the deck strip and fan uses were assessed [USEPA, 2006 a] (no additional assessment was conducted for the candle use because the risks were assumed to be similar to the deck strip use). In the deck strip and fan assessment, no EPA
leve ls of concern (LOCs) were exceeded, and it was concluded that risks were not expected for aquatic or terrestrial vertebrates or aquatic invertebrates because of low potential exposure. However, it was concluded that due to the insecticidal properties of metofluthrin, the uses could

pose a direct risk to non-target insects including Federally-listed threatened/endangered species (hereafter referred to as “listed”) and non -listed species. Therefore, the potential for indirect effects to other listed taxa could not be precluded at that time.

S ubsequent to the 2006 assessment, a refined listed species assessment was conducted for the deck strip and fan uses [USEPA, 2006 b ]. In this assessment, EFED determined that no listed

spec ies would be affected through direct or indirect effects from the use of metofluthrin. This was based on the following:

“While it is possible that non-target invertebrates might inadvertently be exposed to the cloud of metofluthrin given off by the devices, further analysis can be done to estimate the ge neral distance (radius) within which such effects might be possible. It is estimated that effects would be unlikely beyond 5 meters; the distance at which no mortality occurred. In addition, metofluthrin was assumed to have a very short half-life in air, with

e stimates ranging from 1.7 to 1.9 hours [see New Chemical Chapter (USEPA, 2006a (July)]. Therefore, clouds of the active ingredient are not expected to persist and move long distances through numerous habitat types. Given the relatively limited area around the metofluthrin dispensing device, the likely setting of use i. e ., in backyards and other

re sidential areas and where people hike and otherwise participate in outdoor activities, and the short half-life, the probability of impacting endangered invertebrates is so low as to amount to no effect. Based on this further analysis, no direct effects to endangered
inver tebrates are expected.” (USEPA, 2006 b , p. 2)

### 6

Drinking Water Exposure Assessment

Metofluthrin has a relatively high vapor pressure, thus, it would be expected to dissipate into the air. If used during daylight hours, metofluthrin can also undergo photodegradation in the air ( half-life < 2 hours). Metofluthrin that is deposited on land surfaces is expected to have low persistence and low mobility, based on the results of laboratory studies (aerobic soil half-lives < 4 days; K

oc 

### > 3700 mL/g
oc 

### ). Metofluthrin that reaches water is stable to hydrolysis in acidic and neutral conditions but may hydrolyze in alkaline conditions (pH 9, t 1⁄2 

### = 33 days) and can degrade through photolysis (t 1⁄2 

### = 6 days). These properties, along with the low deposition rates, indicate that the potential for metofluthrin to reach a water body is very low.

Based upon the uses and the environmental fate properties of meto fluthrin

, EFED did not

c onduct a drinking water exposure assessment to quantify the potential concentration of
metof luthrin residues in drinking water.

Stressor Source and Distribution

Metofluthrin is a synthetic pyrethroid insect repellent and insecticide. There are currently three
end -use outdoor products (all containing metofluthrin as the sole active ingredient) registered for
metof luthrin, all used to repel adult mosquitoes. One is a folded paper strip that is impregnated
with m etofluthrin and is hung in outdoor areas such as decks, porches, barns, stables and kennels [DeckMateTM Mosquito Repellent; EPA Reg. No.: 10308-31; 1.82% active ingredient (a.i.)] (deck strip). Another is an impregnated insert that is used with a battery-operated portable, personal fan that blows air to create a vapor of chemical [Master Name: NORM1 (alternate names: OFF! Clip-On, OFF! Repellent Fan); EPA Reg. No.: 4822-542; 31.2% a.i.] (fan). This

pr oduct is for use outdoors ( e.g ., when camping, fishing, hunting, boating, on the patio or deck,or at the beach). The third registered product is an impregnated fiberglass ring that is heatreleased over a candle meant to be used on patios, decks, and campsites [Charger (alternatename: OFF! Patio Protector); EPA Reg. No.: 4822-583; 31.68% a.i.] (candle). There is one enduse indoor

product that contains metofluthrin, piperonyl butoxide, and clothianidin as the active ingredients [VBC 3 

### Insecticide (alternate name: Crossfire); EPA Reg. No.: 73049-482; 0.1% metofluthrin] (soluble concentrate applied as a spray), and is targeted to kill bed bugs. This

pr oduct is registered for indoor commercial and residential use s a s a direct surface spray on nonfood areas, mattresses, and for crack and crevice and perimeter applications. For the purpose of evaluating potential ecological exposures and effects from uses of metofluthrin, this assessment will focus only on the products registered for outdoor uses.

Pesticidal Mechanism of Action

Metofluthrin is a synthetic pyrethroid that, when employed as a vapor, repels mosquitoes. Repellency is the result of a reaction at the threshold of neural activation and knockdown which causes the exposed insect to lose its ability to find its host (see Kawada, et al. , 2004b). Although it is being reviewed for Registration Review as a repellent, it also has been shown to kill

mosq uitoes ( e .g. , Kawada et al., 200 4 a and 2004b) and other insects (MRIDs 47048301, 47414001).

### 7

Overview of Pesticide Use and Usage

The pesticide is dispersed from impregnated material and is meant to be used outdoors ( e .g ., patios, decks, campsites, beaches, parks, sporting events). Three end-use products are currently registered for use (see Table 1 ). The labels for EPA Registration Numbers (NORM1) 4822-542

a nd (Charger) 4822-583 specify percent active ingredient but do not specify an amount (mass of

pr oduct or active ingredient). For EPA Registration No. 10308-31 (DeckMate), the label specifies that one strip contains 200 mg of metofluthrin. Whe re not specified on the label, the amount of active ingredient was estimated from product packaging ( APPENDIX A ). Produc t information for each registration is summarized in T able 1.

TABLE 1. Registered Metofluthrin End-Use Products.

Product Name (EPA Reg. No .) % A.I. [ Amount of

a.i. Per Product ] Type of Product Use Sites Application Rates

DeckMateTM Mosquito Repellent (10308

- 31) 1.82% [ 200 mg per

strip ] Folded paper strip

that is impregnated
with metofluthrin Hung in outdoor

areas such as decks, porches, barns,
stables and kennels Two deck strips per

100 ft 2 (can be re

used for up to 36 hrs)

Master Name: NORM1 (4822

- 5 42) 31.2% [ 15 mg per

refill disk ] 1 Impregnated insert

that is used with a battery operated portable, personal
fan Used when outdoors

( e.g ., when camping, fishing, hunting, boating, on the patio or deck, or at the beach) Assumed 1 fan per

person

Charger (alternate
name: OFF! Patio Protector) (4822

- 583) 31.68% [ Estimated

215 mg per ring ] 1 Impregnated

fiberglass ring (the ring is heated by a candle) U sed outdoors in

areas such as patios, decks, and campsites Use one candle in an

area up to 10 ft by

10 ft; use two or more in larger areas

1 Determined from product packaging (See APPENDIX A).



### For modeling purposes to assess exposure, an application rate of 0.00388 lb a.i./acre (1,720 mg a.i./acre) was estimated for the candle use by assuming there are houses on quarter acre lots throug hout a watershed. It was assumed that each house had two candles in the yard as recommended on the label (8 candles/acre). Additionally, it was assumed that the entire amount
of act ive ingredient from each candle is released into the environment at the same time, which
lea d s to a very conservative estimate of potential exposure. Exposure from the deck strips would
be essentially the same as for the candles. The exposure from the personal fan is expected to be
lowe r than the potential exposure from the deck strip or candle uses (due to a lower amount of a.i./device). Therefore, although only the candle use was quantitatively assessed, the deck strip and candle estimated application rates are expected to be similar, and are representative of peak,

c onservative exposure values for metofluthrin.

Environmental Fate and Transport

A summary of the physical/chemical properties and the environmental fate properties of metofluthrin submitted in support of the registration is provided in T able 2

. Due to the uses of metofluthrin and expected limited exposure, several of the environmental fate studies were not

re quired. Metofluthrin is a mixture of two isomers, the E

- and the Z -isomer, which differ in the position of the final carbon on the prop-1-enyl chain. The active ingredient is made up of

a pproximately 92% Z

-isomer and 8% E -isomer. Environmental fate studies show that the two

### 8

isomers behave in similar ways in the environment. A detailed review of the environmental fate
studies can be found in the New Chemical Chapter [USEPA, 2006a (July)].

Metofluthrin has a relatively high vapor pressure and will readily volatilize and , if exposed to sunlight, is also expected to photo-degrade in air with an estimated half-life of less than 2 hours. Along with the low quantity of active ingredient in contained in each device, this leads to a low likelihood of significant deposition given that the chemical will likely dissipate through a

c ombination of degradation and dilution through its release into large volumes of air. Laboratory studies suggest that any metofluthrin that is deposited on land surfaces will have low persistence and low mobility. Metofluthrin that reaches water is stable to hydrolysis in neutral and acidic conditions but degrades in alkaline conditions and through photolysis. Due to its high soil partition coefficient, metofluthrin would tend to bind to soil particles rather than remain in the
water column.

TABLE 2. Physical/Chemical Properties and Environmental Fate Properties of

M etofluthrin.

P arameter V alue ( s ) S ource (Classification)

Molecular Structure

Chemical Name 2,3,5,6

- tetrafluoro

- 4

- (methoxymethyl)benzyl( E

, Z )

- (1 R ,3 R )

- 2,2

- dimethyl

- 3

- (prop

- 1

- enyl)cyclopropanecarboxylate

Chemical Class Pyrethroid ester insecticide

Molecular Formula C 18 H 20 F 4 O 3 – Molecular Weight 360.35 g/mol MRID 46406754

Solubility
in water (20 o C) 0.50 mg/L ( Z

- isomer )
0.67 mg/L ( E

- isomer

) MRID 46406708

(Acceptable)

Vapor Pressure (20 o C) 1.47 x 10 - 5 mmHg (torr) MRID 46402005

Henry’s Law Constant (20 o C) 1.5 x 10 - 5 atm m 3 /mol ( Z

- isomer )

1.1 x 10 - 5 atm m 3 /mol ( E

- isomer ) Estimated from vapor

pressure & solubility a

Hydrolysis Half

- life (25 o C) pH 4 & 7 : S table

pH 9 : 33 days MRID 46406750 (Acceptable)

### 9 P arameter V alue ( s ) S ource (Classification)

Aqueous Photolysis
Half

- life (pH 4 ) 6 days MRID 46406754 (Supplemental) [Based on 12

- hour light/

12

- hour dark cycle with Xe lamp]

Photodegradation in Air

Metofluthrin 1.7 to 1.9 hours 46454103 ( Supplemental b )

Soil Photolysis

- Not required

Aerobic Soil Metabolism
Half

- life MS sandy loam : T 1⁄2 = 2.4

- 3.5 days c

DT 50 = 3

- 8 days

CA sandy loam : T 1⁄2 = 2.3

- 2.9 days c

DT 50 = 1

- 3 days MRID 46406751 (Supplemental)

Aerobic Aquatic
Metabolism Half

- life - Not required

Soil Partition Coefficient (K d ) 57.5, 75.8, 85.3, 163 mL/g MRID 46406753 (Supplemental) [EFED calculated, based on submitted data]

Organic Carbon Partition Coefficient (K

oc ) 3704, 4489, 5414, 7187 mL/g

oc MRID 46406753 (Supplemental) [EFED calculated,
based on calculated K d ]

Octanol/water partition coefficient Log K

ow (25 ◦ C) 5.03 (S

- RTE

, E

- isomer )
4.97 (S

- RTZ

, Z

- isomer ) MRID 46406711

(Acceptable)

Terrestrial Field Dissipation - MRID 46406755 ( waived)

a Estimated as Hg = vapor pressure (atm) ÷ solubility (mol/L)

b Estimated photodegradation rates using the Atmospheric Oxidation Program (AOPWIN, Version 1.90, 2000), a component of the EPA’s EpiSuite software

c Using results of 0 to 14 days for calculation of first-order regression (linear)

### 10

Environmental Fate Properties

The environmental fate of metofluthrin that is deposited in terrestrial and aquatic environments can be characterized based on results from guideline environmental fate studies, summarized below (see Table 2 ). Structures of the identified degradates are given in A PPENDIX B

. In soil,
metofluthrin has a short half- li fe (T 1⁄2 

### < 3.5 days) and low mobility (organic carbon partition

c oefficien t K
oc 

### >3704 mL/g
oc 

### ). DT 90 

### s were less than 14 days for both soils. Along with the low
de position rates expected for the registered uses, these properties suggest that metofluthrin has a low potential for transport to surface water or ground water. Additionally, in water the high K
oc 

### sugg ests that metofluthrin would preferentially bind with soil particles rather than remain in the
water column.

Metofluthrin is stable to abiotic hydrolysis for at least 30 days at 25 o 

### C in acidic and neutral conditions (pH 4 and 7), but in alkaline conditions (pH 9), it degrades with a half-life of 33 days (MRID 46406750). This base-catalyzed degradation proceeded via ester cleavage to form the

c orresponding carboxylic acid MMCA and the alcohol MFOA as major degradates. At study

ter mination, each of the degradates remaining were at maximum levels of approximately 50% of the applied. Metofluthrin can also degrade through aquatic photolysis with a half-life of 6 days (MRID 46406754). A half-life of 6 days was measured for this process, although there is some uncertainty in this value, because the concentration of co-solvent was present at 10%. Photodegradation leads to the major degradate Diol-1264 (max. 17%), formed through oxidation
of the prop-1-enyl moiety, as well as the ester cleavage products MMCA (max. 5%) and MFOA (ma x. 24%). Aquatic metabolism studies we re not required for assessing these residential outdoor uses, and so no aquatic metabolism data were available. The degradation product

a cronyms, structures, and studies where they were formed are summarized in APPENDIX B

.

In soil, metofluthrin undergoes rapid microbial metabolism under aerobic conditions. An aerobic soil metabolism study measured transformation rates in sandy loam soils from California and Mississippi (MRID 46406751). In both soils, calculated half-lives were less than 3.5 days,

e mpirical DT 50 

### s were less than 8 days, and DT 90 

### s we re less than 14 days in all cases. The ester cleavage product MFOA was immediately oxidized to MFOA-D, which reached a maximum of
76% of the applied. Further oxidation led to TFPA at up to 57% of the applied. The corresponding ester cleavage product, MMCA, was present at up to 22% of the applied. Oxidation of MMCA led to t-COOH-CA, present at up to 19% of the applied. By study

ter mination, in most cases these degradates were declining or not detectable while bound residues and carbon dioxide were increasing, accounting for 5.5 to 14.3% and 48 to 89% of the applied compound, respectively. EFED is not aware of any toxicity data that indicate that any of
the de gradates is more toxic than the parent. Because of this, the low exposure potential for
metof luthrin (and, thus, its degradates), and the conservative exposure assumptions made; the risk assessment for the parent only is expected to be protective of exposure to metofluthrin and
it s degradates. Therefore, exposures to parent alone are assessed here.

Metofluthrin sorbs strongly to soil. Batch equilibrium tests conducted in four soils found K d 

### values ranging from 60 to 182 mL/g (MRID 46406753). Strong correlation between soil organic
carbon and K d 

### values for different soils (R 2 

### = 0.99) indicates that metofluthrin sorption is dependent on soil organic carbon, with K

oc 

### values ranging from 3704 to 7187 mL/g
oc 

### . Based on these values, metofluthrin is categorized as slightly mobile according to the FAO mobility

### 11

classification scheme (FAO, 2000). Column leaching studies were not conducted, and the

ter restrial field dissipation requirement was waived.

Ecological Effects

Metofluthrin is classified as practically non-toxic to birds and mammals, very highly toxic to freshwater animals (vertebrates and invertebrates), and highly toxic to young adult bees on an

a cute exposure basis. No toxicity data are available for plants (aquatic or terrestrial), and the
onl y available chronic toxicity data for metofluthrin are for rats. A summary of the toxicity data

a nd the resulting measures of ecological effect selected for each taxonomic group are included in

T able 3.

TABLE 3. Summary of Measures of Effects of Metofluthrin.

Study REGISTRANT SUBMITTED STUDIES

MRID Status Measures of Effects

Avian Acute Oral

[Northern Bobwhite Quail ( Colinus virginianus )] 464067

- 57 Acceptable LD 50 >2250 mg/kg

- bw

Ruffled appearance, reduced reaction to stimuli, loss of coordination, lower limb weakness, loss of righting reflex, minor muscle fasciculation, tremors, and gaping during the first day. There was no mortality

.

Avian Sub

- a cute Dietary

[Northern Bobwhite Quail ( Colinus virginianus )] 464067

- 58 Acceptable LC 50 >5760 mg/kg

- diet

No adverse effects were noted in the study

.

Avian Sub

- a cute Dietary

[Mallard Duck (

Anas platyrhynchos ) ] 464067

- 59 Acceptable LC 50 >5760 mg/kg

- diet

Trembling and weight gain reduction were observed

. There was n o mortality

.

Rat Acute Oral 46406719 Acceptable LD 50 >2,000 mg/kg

- bw

Rat Reproductive Development 464541

- 12 Acceptable NOAEL = 20 mg/kg

- bw/day (equivalent to 400 mg a.i./kg

- diet) ( based on maternal mortality during the 57 days of dosing )

There were no reproductive effects observed during the study

. H owever, mortality to parents would reduce reproduction in natural populations.

Honey Bee Acute

( Apis mellifera ) 474140

- 01 Acceptable LD 50 = 0.015 μg a.i./bee

NOAEL = 0.00625 μg a.i./bee (based on mortality)

Freshwater Fish Acute Toxicity

[ Rainbow Trout ( Onchorynchus mykiss )] 464067

- 61 Acceptable LC 50 = 1.2 μg a.i./L

. NOAEC = 0.71 μg a.i./L (based on mortality and clinical signs of toxicity)

Loss of equilibrium, lethargy, and mortality were observed.

### 12 Study REGISTRANT SUBMITTED STUDIES

MRID Status Measures of Effects

Freshwater Invertebrate

Acute Toxicity

[ Daphnid ( Daphnia magna )] 464067

- 62 Acceptable E C 50 = 4.7 μg a.i./L

Effects were immobilization, lethargy and death

.

Aquatic and Terrestrial
Plants No data available



### 1

. Open Literature

In addition to submitted data, data available from the open literature are considered for this assessment. Kawada, et al. (2004a and 2004b) tested the deck strip in both laboratory and field. Mosquitoes were placed in cages at varying distances from suspended deck strips. The study

a uthors found that all of the mosquitoes in cages directly under the test strip were knocked down within three hours and were dead within 24 hours of initial exposure. In the cages that were placed 1.5 meters from the metofluthrin strip, 50% of the mosquitoes were dead six hours after

tre atment. The registrant’s submitted material states that one strip will treat about 50 ft 2 

### , or about 4.5 m 2 

### . Kawada, et al

. (2004b ) determined that no mosquitoes were knocked down (killed) at a distance of 5 m from the strip and estimated that a single strip was effective in an

a rea of about 5 m 2



### . The fan device and candle contain less metofluthrin than the deck strip and
ha ve a lower rate of emission and so are expected to have a smaller area of impact.

Ecological Incidents

Reviews of the Ecological Incident Information System (EIIS, version 2.1), the Avian Incident Monitoring System (AIMS) 1 

### , and the Incident Data System (IDS) were conducted on June 6,

2012 . There were no reported ecological incidents associated with metofluthrin.

Characteristics of Ecosystems Potentially at Risk

The ecosystems potentially at risk are often extensive in scope; 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 ecosystems potentially at risk from conventional pesticide uses could include the areas immediately adjacent to the application site. Aqua tic ecosystems potentially at risk include water bodies adjacent to, or downstream from, the application site.

Assessme nt Endpoints

A summary of the terrestrial and aquatic toxicological endpoints for metofluthrin can be found in

T able 3 in t he Ecological Effects section.

1 http://www.abcbirds.org/abcprograms/policy/toxins/aims/aims/login.cfm?CFID=113048231&CFTOKEN=9243482

### 13

Conceptual Model

The conceptual models for aquatic and terrestrial exposures are shown in Figures 1 and 2

, respectively. For the currently registered uses, metofluthrin is released into the air as a vapor throug h passive dissipation or heat- or fan-driven evaporation. For these uses, the active ingredient is initially present in the atmosphere in a volatile form but is expected to dissipate

ra pidly through a combination of degradation and dilution by the large volume of air into which it is released. Aquatic and terrestrial exposure occurs only after metofluthrin has been deposited on land or water surfaces. In the conceptual models, dashed lines denote exposure routes not assessed due to the likelihood of low potential exposure. Because the exposure (from all of the potential r outes) of non -target organisms to metofluthrin from the currently registered uses is

e xpected to be low, all of the lines on the conceptual models are dashed.

### 14

Figure 1. Conceptual Model for Effects of Metofluthrin on Aquatic Systems

### 15

Figure 2. Conceptual Model for Effects of Metofluthrin on Terrestrial Systems

### 16

Risk Hypothesis

The following ecological risk hypothesis is being employed for this national-level ecological risk

assessment:

Metofluthrin, when used in accordance with current labels, can result in off-site movement of the compound leading to exposure of non-target plants and animals. Exposures in these environmental compartments are expected to be below levels

where adverse effects upon the survival, growth, and reproduction of non-target terrestrial and aquatic organisms (including listed species) would occur.

Anal ysis Plan

In order to address the risk hypothesis, the potential for adverse effects to non -target organisms is

e stimated. The use, environmental fate, and ecological effects of metofluthrin are characterized

a nd integrated to assess risk by using a risk quotient (ratio of exposure concentration to effects

c oncentration) approach when possible. When a risk quotient approach is not possible, risks are

a ssessed qualitatively.

Measures of Exposure

The candle use is the only use quantitatively assessed via standard exposure models because the candle use is expected to result in peak exposure estimates (estimated application rates for the candle are expected to be higher than the fan use, and similar to, but slightly higher, than the deck strip use). Therefore, potential aquatic exposure to metofluthrin is not quantified directly
for the fan or deck strip uses. Instead, EFED estimates the amount of active ingredient that would have to reach a water body to result in risk to non-target organisms and qualitatively
discusse s the likelihood that this might happen. For the candle use, estimated environmental

c oncentrations ( EEC ) are calculated using Tier I exposure models: Terrestrial Residue Exposure ( T-REX; version 1.5 ) for terrestrial environments and the GENeric Estimated Exposure Concentration 2 (GENEEC2 ; version 2.0) for aquatic environments (see T able 4 ).

T-REX runs [using the following assumptions: 1 application at 0.00388 lb a.i./acre (candle) ; default foliar dissipation half-life of 35 days] resulted in a pe ak dietary-based EEC of 0. 9 4 ppm (short grass). The EECs for the other dietary categories were 0.43 ppm (tall grass), 0.53 ppm (broadleaf plants), 0.06 (fruits/pods/seeds), and 0.37 ppm (arthropods) (see APP ENDIX C for
de tails).

An application rate of 0.00388 lb a.i./acre from candles was estimated using a series of conservative assumptions about the extent of use and the potential for deposition (see above).

GENEEC2 runs resulted in a peak EEC of 0.03 μg a.i./L (candle). These models are not specifically designed to handle uses such as those for metofluthrin, but by making several conservative assumptions in describing the use, these models are sufficient to establish a

c onservative upper bound on potential exposure for the purposes of quantitatively assessing ecological risk.

### 17

TABLE 4. GENEEC Input Parameters for Metofluthrin (Deck Strips and Candle) a



### .

Parameter Input Source

Application Rate 0. 00388 lb a.i./A Estimated : 4 houses/A * 2 strips/house *

2 15.6 mg a.i./ ring * 1 lb/453590 mg

Number of Applications 1

Wetted in? No

Application Method Ground; Low boom, coarse droplets Sets amount of a.i. reaching water body through drift at 0.8% b

.

Solubility in Water 0.67 mg/L MRID 46406750 (Highest reported value; for E

- isomer )

Organic Carbon Partitioning
Coefficient (K

oc ) 3704 mL/g MRID 46406753 (lowest value c )

Hydrolysis Half

- life at pH 7 Stable MRID 46406750

Aerobic Soil Metabolism
Half

- life Stable Not anticipated to be exposed to soil, thus, assumed no degradation.

Aerobic Aquatic Metabolism
Half

- life Stable No data

Aquatic Photolysis Half

- life 6 days MRID 46406754 (assuming 12 hr sunlight/day)

a Rate for candle (0. 003 88 lb a.i./A) is used to also represent the deck strip use (0.00353 lb a.i./A)

b This value is thought to be conservative as drift is related to water droplet size where metofluthrin is in the vapor phase.

c http://www.epa.gov/oppefed1/models/water/input_parameter_guidance.htm . EFED guidance recommends using
the mean K

oc , using the lowest K

oc would result in highest EECs.



### The S creening I mbibition P rogram (SIP v.1.0, Released June 15, 2010) was used to calculate an upper bound estimate of exposure to wildlife via drinking water using metofluthrin’s aquatic solubility limit [0.67 mg/L ( E-isomer )], the most sensitive acute avian toxicity endpoint (bobwhite quail LD 50 

### >2,250 mg/kg-bw ; no c hronic avian data are available), and the most sensitive acute and chronic mammalian toxicity endpoints for metofluthrin (rat LD 50 

### >2 ,000 mg/kg-bw, and NOAEL = 20 mg a.i./kg-bw, respectively). Drinking water exposure alone was
de termined not to be a potential pathway of concern for avian or mammalian species on an acute
ba sis or mammalian species on chronic basis. Although not assessed due to a lack of data, drinking water is not expected to be an exposure route of concern for birds from chronic exposure to metofluthrin. For a sample of the output generated by SIP v.1.0, please see

### 18

APPENDIX D . 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

.

The S creening T ool for I nhalation R isk (STIR v.1.0, November 19, 2010) was used to calculate an upper-bound estimate of vapor-phase exposure using metofluthrin’s vapor pressure (1.47 x

10 -5 

### mm Hg ) a nd molecular weight (360.35 g/mol). STIR incorporates results from severaltoxicity studies including acute oral and inhalation rat toxicity endpoints obtained from the “sixpack” of core studies, 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 [rat acute oral LD 50 

### >2,000 mg a.i./kg-bw and acute inhalation LC 50 

### = 1.08 mg/L (MRID 46406723), respectively], as well as the most sensitive acute oral avian toxicity endpoint ( bobwhite quail LD 50 

### > 2,250 mg a.i./kg-bw). The conservative estimated application rate of

0.003 88 lb a.i./acre (candle) w as used. Based on the results of the STIR model, inhalation exposure alone was determined not to be a potential pathway of concern for avian and mammalian species on an acute inhalation exposure basis (see A PPENDIX E for details).

Measures of Effect

Where available, sublethal effects observed in both registrant-submitted and open literature
studies is evaluated qualitatively. In the available metofluthrin toxicity studies, such effects include reduced reaction to stimuli, tremors, loss of coordination, and lethargy. Quantitative assessments of risks, though, are limited to those endpoints that can be directly linked to the Agency’s assessment endpoints of impaired survival, growth and reproduction.

The assessment of risk for direct effects to non-target organisms makes the assumption that toxicity of metofluthrin to birds is similar to terrestrial-phase amphibians and reptiles. The same

a ssumption is made for fish and aquatic-phase amphibians. The acute measures of effect used for animals in this screening-level assessment are the acute LD 50 

### , LC 50

, 

### and EC 50 

### . Endpoints for chronic measures of exposure for listed and non-listed animals are the NOAEL and/or NOAEC.

Inte gration of Exposure and Effects

Risk characterization is the integration of exposure and ecological effects characterization to determine the potential ecological risk from the use of metofluthrin via deck strips, personal fans, and candles, and the likelihood of direct and/or indirect effects to non-target organisms in aquatic

a nd terrestrial habitats. The exposure and toxicity data are integrated in order to evaluate the risks of adverse ecological effects to non -target species. For the assessment of metofluthrin exposure and potential risks associated with the candle use, the risk quotient (RQ) method is
used to compare exposure and measured toxicity values. EECs are divided by the acute and

c hronic toxicity values (if available). The resulting RQ values are then compared to the Age ncy’s LOC values (USEPA, 2004) (see Table 5 ). These criteria are used, in addition to other available data ( e.g ., incident data), to indicate when meto fluthrin ’s uses, as directed on the label, have the potential to cause adverse direct or indirect effects to non-target organisms. The
risks a ssociated with the personal fan and deck strip uses will be qualitatively discussed based on
the available data.

### 19

TABLE 5. Agency Levels of Concern (LOC).

Risk Description RQ Taxa

Acute Potential for acute risk to non

- target organisms

which may warrant regulatory action in addition
to restricted use classification acute RQ > 0.5 aquatic animals, mammals, birds

Acute Restricted

Use Potential for acute risk to non

- target organisms,

but may be mitigated through restricted use
classification acute RQ > 0.1 aquatic animals

acute RQ > 0.2 mammals and

birds

Acute Listed Species Listed species may be potentially affected by

use acute RQ > 0.05 aquatic animals

acute RQ > 0.1 mammals and

birds

Chronic Potential for chronic risk may warrant

regulatory action, listed species may potentially be affected through chronic exposure chronic RQ > 1 all animals

Non

- Listed and
Listed Plant Potential for effects in non

- listed and listed

plants RQ > 1 all plants



### Endangered Species Assessments

Consistent with the EPA’s responsibility under the Endangered Species Act (ESA), EPA
evaluated risks to listed species from registered uses of metofluthrin.

2. RISK CHARACTERIZATION

RISK ESTIMATION

Aquatic Animals

To assess the potential for effects of a pesticide use to aquatic organisms, an EEC is typically determined by modeling the transport of an applied pesticide into the farm pond, a water body of defined proportions and volume ( i.e., 20,000,000 L). The devices available for metofluthrin use ( i.e

., personal fan, candle and deck strip) can be used by any number of people in any locations for any length of time, so it is difficult to specifically describe the use for the sake of modeling aquatic exposure. For an LOC not to be exceeded, the RQ calculated from the EEC and the

tox icity endpoint must be lower than the LOC. This calculation can be reversed to determine the lowest EEC that would be expected to lead to an LOC exceedance:

RQ (below LOC) 

### < LOC and
RQ (below LOC) 

### = EEC (below LOC) 

### ÷ toxicity value; therefore

EEC (below LOC) 

### < LOC * toxicity value.

### 20

All values and equations used in this calculation are summarized in Table 6

. From the available
data on the effects of metofluthrin to aquatic animals (both vertebrates and invertebrates), the most sensitive endpoint is for rainbow trout with an LC 50 

### of 1.2 μg a.i./L. The highest aquatic risk category is for acute risk to endangered species with an LOC of 0.05. Inserting these values into the above equation leads to the result that for an aquatic LOC not to be exceeded, the EEC

must be less than 0.06 μg a.i./L (0.05 * 1.2 μg a.i./L ).

Table 6. Amount of Metofluthrin in an Aquatic Environment th at would Exceed the Most
S ensitive Level of Concern.

Parameter Inputs and Results

Most sensitive endpoints LOC = 0.05 ( listed s pecies) Toxicity = 1.2 μg a.i./L (Rainbow Trout LC 50 )

EEC in farm pond leading to LOC
exceedance 1 0.06 μg a.i./L

Amount of a.i. in farm pond leading to LOC
exceedance 2 1.2 g

Amount of a.i

. per device 3 Personal Fan 15 mg a.i./device Candle

215.6 mg a.i./device Deck Strip

200 mg a.i./device

No. of devices from which entire contents

must end up in pond lead ing to LOC
exceedance 4 80 devices ~6 devices 6 devices

1 RQ (below LOC) < LOC and RQ (below LOC) = EEC (below LOC) ÷ toxicity value therefore EE C (below LOC) < LOC * toxicity value

2 Volume of pond = 20,000 m 3 . Dissolved compound = EEC * volume.

3 MRID 46406752

4 (Amount of a.i. in pond) ÷ (Amount of a.i. per device) = No. of devices to exceed the LOC



### The entire contents of at least 80 personal fan devices and 6 deck strips/candles would need to end up in the farm pond to exceed levels of concern for aquatic animals. Due to low deposition

rates and subsequent dilution in air combined with rapid degradation in air, soil, and water via photol ysis, the amount of metofluthrin that may reach a water body from a single device, deck strip or candle is, in reality, far lower than the total amount of active ingredient contained in each device. The actual number of devices needed to lead to an LOC exceedance, then, is even

g reater than the conservative estimates made here.

The candle and deck strip have a higher amount of metofluthrin in each unit than the fan. For the

c andle and deck strip, the active ingredient from only 6 devices would need to reach the water body to lead to an LOC exceedance. Although unlikely to occur, this situation is within the realm of possibility, so a more detailed analysis using the Tier I aquatic model GENEEC2 was conducted to assess the potential for risk from metofluthrin released using the candle application rate (which was used to represent peak exposures). The peak EEC calculated from GENEEC2

wa s 0.03 μg a.i./L (candle) (see T able 4 ). When this EEC is compared to the available acute

### 21

toxicity endpoints for freshwater fish and freshwater invertebrates, none of the RQs for the candle use exceed an Agency LOC (see Table 7 ).

TABLE 7. RQs for the Candle Use and Freshwater Animals.

Species Toxicity

Endpoint (μg

a.i. /L) P eak EEC (μg

a.i. /L) Acute RQ Level of Concern

Exceeded

Rainbow Trout LC 50 = 1.2 0. 03 0.025 None

Daphnid EC 50 = 4.7 0. 03 0.006 None



### Terrestrial Animals

All of the available acute toxicity data for birds and mammals resulted in non-definitive endpoints ( i.e

., “greater than” values) and indicate that metofluthrin is practically non-toxic to
these organisms (and by extension to reptiles and terrestrial-phase amphibians for which birds

se rve as surrogates) on an acute exposure basis. Therefore, RQs cannot be calculated for birds and mammals from acute exposure to metofluthrin. However, all of the exposure values,

c onservatively estimated using T-REX, were well below the highest concentrations tested in the available acute toxicity studies for terrestrial animals (see A PPENDIX C for details). For

e valuating potential risk from chronic exposure, exposures wer e calculated assuming the maximum estimated label application rate for the candle use (which is expected to be higher than the application rate for the personal fan and similar to the deck strip). Exposures were estimated assuming that all of the metofluthrin in 8 candles/acre (see the ‘Overview of Pesticide Use and Usage’ section above) was released at the same time and deposited as residues on food items.
This i s assumed to result in conservative, peak EECs. Assessments for birds and mammals are
ba sed on dietary exposure to pesticides through the ingestion of contaminated plant or animal

mate rial that is consumed as food. Based on the EECs from T-REX using an estimated

a pplication rate of 0.00388 lb a.i./acre for the candle use, none of the RQs for mammals (different size and dietary categories) exceed the chronic risk LOC ( i.e ., all of the chronic mammalian RQs are ≤0.39) (see A PPENDIX C for details).

There is one acceptable honey bee contact study available for metofluthrin using the European honey bee (

Apis mellifera ) with an LD 50 

### of 0.015 μg a.i./bee (MRID 47414001). There is also an acute contact study available using the Asian bee Apis cerana indica with an LD 50 

### of 0.0089 μg a.i./bee (MRID 47048301). This latter study was classified as supplemental because it was not
conducted with A. mellifera , no raw data were submitted (therefore, the statistics could not be verified), and the age of the bees and lighting conditions during the study were not reported. However, regardless of whether data from A. mellifera or A. cerana are used, metofluthrin is classified as highly toxic to bees, and therefore terrestrial invertebrates, on an acute exposure
ba sis.

Because metofluthrin is used as an insect repellent and has potential insecticidal properties, it is assumed that any terrestrial invertebrate ( e .g ., honey bee or listed flying terrestrial invertebrate species) that is exposed to metofluthrin via ambient exposure ( i.e ., flying through the metofluthrin released by the deck strip, fan or candle) has the potential to be repelled, and perhaps killed. From the Kawada, et al ., studies (2004a and 2004 b ), it is not known how many of

### 22

the caged mosquitoes that died would have been repelled and flown away if they had not been in a cage. It is possible that a mosquito that flew into a cloud of metofluthrin vapor would be

re pelled and fly away unharmed or fly away with neural damage that would lead to its death or reduce its reproductive ability. The same could be true for honey bees and listed terrestrial
invertebrates that enter the treated area.

Kawada, et al

. , (2004b ) determined that no mosquitoes were knocked down (killed) at a distance
of 5 m from the deck strip. The candle has a similar ‘efficacy’ rate as the deck strip based on the
labels ; the labels state that the deck strip and the candle can both treat up to a 10-ft x 10 -ft area.
The fan device contain s less metofluthrin than the deck strip or candle and has a lower rate of
emission and so is expected to have a smaller area of impact. Mosquitoes actively track humans
in order to obtain a blood meal. Bees and listed terrestrial invertebrate species would not be expected to be attracted to humans. Therefore, a non-target terrestrial invertebrate would be exposed to the metofluthrin only by chance, or because it ( e.g. , a moth) was flying toward a light (such as with a burning candle).

Screening-level risk assessments do not typically evaluate risks to terrestrial invertebrates; however, toxicity information for beneficial insects is used to develop precautionary label language where necessary. Based on the available toxicity data alone, precautionary label lang uage for bees would normally be recommended. However, because of the limited exposure potential to bees from the registered metofluthrin uses, the precautionary label language is not considered necessary for the current uses as a deck strip, fan, or candle.

Additionally, given the relatively limited area around the metofluthrin dispensing devices, the likely setting of use ( i. e ., in backyards and other residential areas and where people hike and otherwise participate in outdoor activities), the short half-life of metofluthrin in air (1.7 to 1.9
hours ), and dilution by the large volume of air into which it is released, the probability of
im pacting listed terrestrial invertebrates is considered low and there is no reasonable expectation
of effects.

Plants

There are currently no data available to assess the potential risk to terrestrial or aquatic plants from the registered metofluthrin uses. Th ere is no reasonable expectation of effects to plants due

to t he low exposure potential.

RISK DESCRIPTION

Based on the available data and the currently registered use patterns for metofluthrin ( i.e

., deck strips, personal fans, and candles), none of the EPA’s LOCs are exceeded for metofluthrin. Where RQs could not be calculated due to the lack of toxicity data, potential e xposure is considered low. Furthermore, there are no known ecological
incide nts reported for metofluthrin. Therefore, the risk hypothesis articulated in the

P roblem Formulation is supported, i.e.

, metofluthrin, when used in accordance with current labels, can result in off-site movement of the compound leading to exposure of

non -target plants and animals. Exposures in these environmental compartments are

e xpected to be below levels where adverse effects upon the survival, growth, and

### 23

reproduction of non-target terrestrial and aquatic organisms (including federally-listed

threatene d and endangered species) would occur (see below for the discussion on listed species)

.

Consistent with the assumptions described in the Health Effects Division’s Standard Ope rating Procedure on assessing risks to humans from residential uses (USEPA, 2012),

pa rticles released from the deck strip, fan, and candle uses are expected to remain airborne rather than be deposited on surfaces and would likely dissipate rapidly. This is
due to the size fraction of particles released. Additionally, any metofluthrin releasedfrom the deck strip, fan, or candle during daylight hours is expected to have a short halfli fe (< 2 hours) in air. Furthermore, based on conservative estimates of exposure for the

c andle use, none of the RQs resulted in LOC exceedances for fish, aquatic invertebrates, birds, or mammals. Therefore, risks to non-target species from the use of metofluthrin are not expected based on the results of the quantitative and qualitative assessment.

Unc ertainties and Assumptions

For the currently registered uses of metofluthrin, the fate of the active ingredient is primarily dependent on its behavior in air. Although there were limited data to fully describe the

e nvironmental fate of metofluthrin in air, soil, and water, this assessment’s consideration of metofluthrin in air is largely qualitative. The registered uses of metofluthrin consist of personal use devices that do not deposit the active ingredient directly on land or water surfaces and onl y affect small areas. EFED conducted modeling based on a set of very conservative assumptions, which very likely lead to overestimates of potential exposure. The amount of overestimation is uncertain, and so this modeling is only useful to establish upper bounds on potential environmental exposure rather than to predict actual concentrations. Although the available data were adequate for assessing the exposure and potential risks associated with the fan, deck strip, and candle uses, additional data may be needed in the future if the use pattern (and, thus, the exposure potential) for metofluthrin changes.

ENDANGERED SPECIES ASSESSMENT

Because direct adverse effects are not expected for birds, reptiles, amphibians, mammals, fish,
and aquatic invertebrates, and there is no reasonable expectation of effects to plants or terrestrial invertebrates, the EPA makes a No Effects (NE) determination for all Federally-listed species and a No Habitat Modification determination for all designated critical habitats for the currently registered uses of metofluthrin.

References

FAO. 2000. Appendix 2. Parameters of pesticides that influence processes in the soil . In FAO Information Division Editorial Group (Ed.), Pesticide Disposal Series 8. Assessing Soil Contamination. A Reference Manual. Rome: Food & Agriculture Organization of the United Nations (FAO). (Accessed July 10, 2009).

### 24

Kawada, H. 2004a. Laboratory and Field Evaluation of Spatial Repellency with MetofluthrinImpregnated Paper Strip Against Mosquitoes in Lombok Island, Indonesia, 2004. J. Amer. Mosquito Control Assn . 20:292-298. Kawada, H., et al., 2004 b. Trial of Spatial Repellency of Metofluthrin-Impregnated Paper Strip Aga inst Anopheles and Culex in Shelters without Walls in Lombok, Indonesia. J. Amer. Mosquito Control Assn . 20:434-437. USEPA. 1998a. Guidance for Ecological Risk Assessment. Risk Assessment Forum. EPA/630/R-95/002F, April 1998. USEPA. 2004. Overview of the Ecological Risk Assessment Process in the Office of Pesticide Programs. Office of Prevention, Pesticides, and Toxic Substances. Office of Pesticide Programs. Washington, D.C. January 23, 2004.

USEP A. 2006a. Section 3 Metofluthrin in the “DeckMate” Strip and the “Norm I” Personal Fan Device as Mosquito Repellent. Office of Pesticide Programs. Washington, D.C. July 28, 2006. (DP Barcode: D313232).
USEPA. 2006b. Refined Analysis of Potential Effects to Endangered Species for Metofluthrin Use as a Mosquito Repellant, Relates to July 28, 2006 Review Entitled: Section 3 Metofluthrin in the “DeckMate” Strip and the “Norm l” Personal Fan Device as Mosquito Repellent. Office of Pesticide Programs. Washington, D.C. August 17, 2006. (DP Barcode: D313232).

USEPA. 2013. De Minimis Subgroup Opinion on Metofluthrin. Office of Pesticide Programs,
United St ates Environmental Protection Agency. Washington, D.C. April 16, 2013.

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

### 25

Environmental Fate Studies Cited

MRID Study (Guideline No.) Study Author and Title

46406754 Aqueous Photolysis

(161

- 2) Ponte, M. (2004) Aqueous Photolysis of (Carbon 14)S

- 1264 in

pH 4 Buffer by Artificial Light. Project Number: QAM/0019, 1238W. Unpublished study prepared by PTRL West, Inc. 251 p.

46406708 Solubility in Water

(830.7840) Walsh, K.; Lentz, N. (2003) Determination of Water Solubility

-

S

- 1264. Project Number: 015634/1, QAP/0019, 015634. Unpublished study prepared by Ricerca Biosciences, LLC. 112 p

46406751 Aerobic Soil

Metabolism
(162

- 1) Kodaka, R.; Sugano, T.; Yoshimura, J.; et. al. (2003) Aerobic

Soil Metabolism Study of [Carbon

- 14]S

- 1264. Project Number: SOI2002B, EF/2003/003, QAM/0014. Unpublished study prepared by Sumitomo Chemical Co. 67 p.

46454101

46402005 Vapor Pressure

(830.7950)

- DiFrancesco, D.; Lentz, N. (2004) Determination of Vapor

Pressure

- S

- 1264. Project Number: 015632/1, QAP/0028. Unpublished study prepared by Ricerca Biosciences, LLC. 82 p.

Driver, J.; Ross, J. (2004) Metofluthrin: Non

- Dietary (Residential) Risk Assessment. Project Number: SCJ/009/04. Unpublished study prepared by Infoscientific.Com, Inc. 34 p

.

46406753 Soil Partition

Coefficients Ponte, M. (2004) Soil Adsorption/Desorption of [Carbon

- 14]S

1264 by the Batch Equilibrium Method. Project Number: 1191W, 1191W/1, QAM/0018. Unpublished study prepared by PTRL West, Inc. 291 p.

46406750 Hydrolysis

(835.2110) Ponte, M. (2004) Hydrolysis of [Carbon

- 14]S

- 1264 at pH 4, 7

and 9. Project Number: 1192W, 1192W/001. Unpublished study prepared by PTRL West, Inc. 187 p.

46406711 Partition Coefficient

(n

- octanol/water)
(830.7550) Walsh, K.; Lentz, N. (2003) Determination of n

- Octanol/Water

Partition Coefficient

- S

- 1264. Project Number: 015633/1, QAP/0023, 015633/0/1. Unpublished study prepared by Ricerca Biosciences, LLC. 86 p



### .

46406755 Terrestrial Field

Dissipation
(164

- 1) Curry, K.; Brookman, D. (2004) Request for a Waiver of the

Requirement for Data on Metofluthrin Terrestrial Field Dissipation. Unpublished study prepared by Technology Sciences Group, Inc. 19 p.

46454103 Photodegradation in

Air Nishyama, M.; Katagi, Takimoto, Y. (2004) Stability in Air of S

1264. Project Number: STA2004A, EF/200 4/032, QAP/0032. Unpublished study prepared by Sumitomo Chemical Co. 9 p

### 26

Ecotoxicity Studies Cited

MRID Study (Guideline No.) Study Author and Title

46406757 Avian Acute Oral

(850.2100) Gallagher, S.; Grimes, J.; Beavers, J. (2003) An Acute Oral

Toxicity Study with the Northern Bobwhite. Project Number: QAW/0005, 166/172. Unpublished study prepared by Wildlife International, Ltd. 50 p.

46406758 Avian Sub

- acute

Dietary (850.2200) Gallagher, S.; Grimes, J.; Martin, K.; et. al. (2003) A Dietary LC

5 0 Study With the Northern Bobwhite. Project Number: QAW/0003, 166/170. Unpublished study prepared by Wildlife International, Ltd. 63 p.

46406759 Avian Sub

- acute

Dietary (850.2200) Gallagher, S.; Grimes, J.; Martin, K.; et al. (2003) S

- 1264: A

Dietary LC50 Study With the Mallard. Project Number: QAW/0004, 166/171. Unpublished study prepared by Wildlife International, Ltd. 64 p.

46406719 Rat Acute Oral

(870.1100) Kunimatsu, T. (2002) Acute Oral Toxicity STudy of S

- 1264 in

Rats: Final Report. Project Number: QAT/0004, 3670. Unpublished study prepared by Sumitomo Chemical Co. Ltd., Envr. Health. 30 p.

46454112 Rat 2

- Generation

(870.3800) Hara, H.; Suyami, S.; Ushimaru, T.; et. al. (2002) Study of

Fertility and Early Embryonic Development to Implantation of S

1264 Administered Orally to Rats. Project Number: QAT/0011, ST01083. Unpublished study prepared by Ina Research Inc. 173

p.

47414001 Honey Bee Acute

(contact) (850.3020) Warmers, C. (2008) Acute Contact Toxicity Test of S

- 1264 TG

to the Honey Bee, Apis me llifera L.: Final Report. Project Number: S/1264/TG, 20071335/02/BLEU, QAW/0012. Unpublished study prepared by Eurofins

- GAB GmbH. 23 p.

47046301 Honey Bee Acute

(contact) (850.3020) Jeyalakshmi, T. (2004) Toxicity of S

- 1264 to Honey Bee, Apis

cerana indica. Project Number: 07/067/2004, 14675, PK/020301G. Unpublished study prepared by International Institute of Biotechnology and Toxicology . 20 p.

46406761 Acute Freshwater Fish

(850.1075) Lima, W. (2004) S

- 1264

- Acute Toxicity to Rainbow Trout

(Onco rhynchus mykiss) Under Flow

- Through Conditions. Project Number: 13048/6398, QAW/0007. Unpublished study prepared by Springborn Smithers Laboratories. 51 p.

46406762 Acute Freshwater Fish

(850.1075) Sayers, L. (2008) S

- 1264 Technical Grade

- Acute Toxicity to

Bluegill Sunfish (Lepomis macrochirus): Under Flow

- Through Conditions. Project Number: 13048/6537, QAW/0014. Unpublished study prepared by Springborn Smithers Laboratories. 74 p.

### 27 Appendix A: Estimates of Metofluthrin Mass for Exposure

M etofluthrin is dispersed from impregnated material and is meant to be used outdoors ( e.g ., patios, decks, campsites, beaches, parks, sporting events). Three end-use products are currently registered for outdoor use (see Table A-1 ). The labels for EPA Registration Numbers (NORM1)

4822 -542 and (Charger) 4822-583 specify % active ingredient (a.i.) but do not specify an amount (mass of product or active ingredient) contained in the impregnated material. For EPA Registration No. 10308-31 (DeckMate) the label specifies that one strip contains 200 mg of metofluthrin. When not specified on the label, the amount of active ingredient was estimated from product packaging downloaded from the internet. The amounts are summarized in Table

A-1.

Appendix A

- 1. Products containing Metofluthrin with Registration Numbers, Net Weights, Percent Active Ingredient (a .i. ), and Weight in AI.

Product EPA Reg No. Net wt (oz) Ne t wt

(mg) % ai mg ai g ai lb ai/unit Unit

Charger 4822

- 583 0.024 1 680.40 31.68 215.55 0.2156 0.000485 Ring

DeckMate 10308

- 31

- - 1.82 200 2 0.200 0.000441 Pad

Norm1 4822

- 542 0.0016 3 46 31.2 14.35 4 0.0144 0.0000326 Refill disk

Repellent fan 0.09 5 2552.46 31.2 796.4 0.796 0.00176 Refill disk+

1 Unit Net weight in oz per ring (from packaging)

2 Unit Net weight in mg per strip (Label EPA Reg No. 10308-31)

3 Unit Net weight in oz per refill disk (Clip-On from packaging)

4 15 mg per refill disk used in previous risk assessment (D312123)

5 Unit Net weight in oz per refill disk (from packaging) (pack contains two refills). This also appears to include more than just the
refill disk.

Conversion Constants oz x 28.35 = mg mg x 1000 = g mg x 0.000002046 = lb (1 lb = 453.592 g)

### 28

APPENDIX B: Parent and Degradate Acronyms, Chemical Name, MRID No., Study Type Where Degradate Occurred, and Chemical Structure.

Appendix E

- 1. Parent and degradate abbreviation, chemical name, MRID No., Study where degradate occurred, and structure

ID Number Chemical

Name MRID Study Type 

### Structure

S

- 1264

RTZ [Z

- isomer] Met o fluthrin a

- -

S

- 1264

RTE [E

- isomer] Met o fluthrin

- -

Diol

- 1264 Not Reported 464541

- 03 aqueous photolysis

(E)

- MMCA Not Reported 46406753

46454103 aerobic soil

metabolism

, aqueous photolysis

(Z)

- MMCA Not Reported 46406753

46454103 aerobic soil

metabolism

, aqueous photolysis

### 2 9

Appendix E

- 1. Parent and degradate abbreviation, chemical name, MRID No., Study where degradate occurred, and structure

ID Number Chemical

Name MRID Study Type 

### Structure

MFOA Not Reported 46406753

46406750

46454103 aerobic soil

metabolism

, hydrolysis

, aqueous photolysis

MFOA

- D Not Reported 46406753

46406750 aerobic soil

metabolism

, hydrolysis

MFFO Not Reported 46406750

46454103 hydrolysis

,

aqueous photolysis

TFPA Not Reported 46406753 aerobic soil
metabolism

t

- COOH

CA Not Reported 46406753 aerobic soil
metabolism

### 30 APPENDIX C: T-REX INPUTS AND OUTPUTS Inputs:

Chemical Name: Metofluthrin

Application Rate 0.003 9 lbs a.i./acre

Half

- life 35 days

Application Interval 0 days

Maximum # Apps./Year 1

Length of Simulation 1 year



### Summary of Risk Quotient Calculations Based on Upper Bound Kenaga EECs

Table 1 . Upper Bound Kenaga, Acute Avian Dose

- Based Risk Quotients

Size
Class (grams) Adjusted

LD50 EECs and RQs

Short Grass Tall Grass Broadleaf

Plants Fruits/Pods/Seeds Arthropods Granivore

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

20 1620.97 1.07 0.00 0.49 0.00 0.60 0.00 0.07 0.00 0.42 0.00 0.01 0.00

100 2063.57 0.61 0.00 0.28 0.00 0.34 0.00 0.04 0.00 0.24 0.00 0.01 0.00

1000 2914.87 0.27 0.00 0.12 0.00 0.15 0.00 0.02 0.00 0.11 0.00 0.00 0.00

Table 2 . Upper Bound Kenaga, Acute Mammalian Dose

- Based Risk Quotients

Size
Class (grams) Adjusted

LD50 EECs and RQs

Short Grass Tall Grass Broadleaf

Plants Fruits/Pods/Seeds Arthropods Granivore

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

15 4395.66 0.89 0.00 0.41 0.00 0.50 0.00 0.06 0.00 0.3 5 8E

- 05 0.0 3E

- 06

35 3556.56 0.62 0.00 0.28 0.00 0.35 0.00 0.04 0.00 0.24 7E

- 05 0.0 1 2E

- 06

1000 1538.32 0.14 0.00 0.07 0.00 0.08 0.00 0.01 0.00 0.0 6 4E

- 05 0.0 0 1E

- 06

Table 3 . Upper Bound Kenaga, Chronic Mammalian Dietary Based Risk Quotients

NOAEC (ppm) EECs and RQs

Short Grass Tall Grass Broadleaf

Plants Fruits/Pods/Seeds/Large

Insects Arthropods

EEC RQ EEC RQ EEC RQ EEC RQ EEC RQ

400 0.94 0.00 0.43 0.00 0.53 0.00 0.06 0.00 0.37 0.00 Size class not used for dietary risk quotients

Table X. Upper Bound Kenaga, Chronic Mammalian Dose

- Based Risk Quotients

Size
Class (grams) Adjusted

NOAEL EECs and RQs

Short Grass Tall Grass Broadleaf

Plants Fruits/Pods/Seeds Arthropods Granivore

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

15 43.96 0.89 0.02 0.41 0.01 0.50 0.01 0.06 0.00 0.35 0.01 0.01 0.00

35 35.57 0.62 0.02 0.28 0.01 0.35 0.01 0.04 0.00 0.24 0.01 0.01 0.00

1000 15.38 0.14 0.01 0.07 0.00 0.08 0.01 0.01 0.00 0.06 0.00 0.00 0.00

### 31 APPENDIX D: SIP Inputs and Outputs

Table B

- 1. Inputs

Parameter Value

Chemical name Metofluthrin
Solubility (in water at 25 o C; mg/L) 0.67

Mammalian LD 50 (mg/kg

- bw) 2000 Mammalian test species laboratory rat Mammalian NOAEL (mg/kg

- bw) 20 Mammalian test species laboratory rat

Avian LD 50 (mg/kg

- bw) 2250 Avian test species northern bobwhite quail Mineau scaling factor 1.15



### Table B

- 2. Mammalian Results

Parameter Acute Chronic
Upper bound exposure (mg/kg

- bw) 0.1152 0.1152 Adjusted toxicity value (mg/kg

- bw) 1538.3211 15.3832 Ratio of exposure to toxicity 0.0001 0.0075

Conclusion* Drinking water exposure alone is NOT a potential

concern for mammals Drinking water exposure

alone is NOT a potential

concern for mammals



### Table B

- 3. Avian Results

Parameter Acute Chronic Upper bound exposure (mg/kg

- bw) 0.5427 0.5427 Adjusted toxicity value (mg/kg

- bw) 1620.9664 0.0000 Ratio of exposure to acute toxicity 0.0003 0.0000

Conclusion* Drinking water exposure alone is NOT a potential

concern for birds Due to insufficient data, risk cannot be precluded

*Conclusion is for drinking water exposure alone. This does not combine all routes of exposure. Therefore, when aggregated with other routes ( i.e ., diet, inhalation, dermal), pesticide exposure through drinking water may contribute to a total exposure that has potential for effects to non

- target animals.

### 32 APPENDIX E: STIR Inputs and Outputs

Input

Application and Chemical Information

Enter Chemical Name Metofluthrin Is the Application a Spray? (enter y or n) y If Spray What Type (enter ground or air) ground Enter Chemical Molecular Weight (g/mole) 360.35 Enter Chemical Vapor Pressure (mmHg) 1.47E

- 05 Enter Application Rate (lb a.i./acre) 0.0035



### Toxicity Properties

Bird

Enter Lowest Bird Oral LD 50 (mg/kg bw) 2250 Enter Mineau Scaling Factor 1.15 Enter Tested Bird Weight (kg) 0.178

Mammal

Enter Lowest Rat Oral LD 50 (mg/kg bw) 2000

Enter Lowest Rat Inhalation LC 50 (mg/L) 1.08 Duration of Rat Inhalation Study (hrs) 4 Enter Rat Weight (kg) 0.35



### Output

Results Avian (0.020 kg )
Maximum Vapor Concentration in Air at Saturation (mg/m 3 ) 2.85E

- 01

Maximum 1

- hour Vapor Inhalation Dose (mg/kg) 3.58E

- 02

Adjusted Inhalation LD 50 6.77E+00

Ratio of Vapor Dose to Adjusted Inhalation LD 50 5.29E

- 03 Exposure not Likely Significant

Maximum Post

- treatment Spray Inhalation Dose (mg/kg) 3.70E

- 04

Ratio of Droplet Inhalation Dose to Adjusted Inhalation LD 50 5.46E

- 05 Exposure not Likely Significant

Results Mammalian (0.015 kg )
Maximum Vapor Concentration in Air at Saturation (mg/m 3 ) 2.85E

- 01

Maximum 1

- hour Vapor Inhalation Dose (mg/kg) 4.50E

- 02

Adjusted Inhalation LD 50 6.43E+01

Ratio of Vapor Dose to Adjusted Inhalation LD 50 7.01E

- 04 Exposure not Likely Significant

Maximum Post

- treatment Spray Inhalation Dose (mg/kg) 4.65E

- 04

Ratio of Droplet Inhalation Dose to Adjusted Inhalation LD 50 7.23E

- 06 Exposure not Likely Significant