# •

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

MEMORANDUM Date: August 2, 2012 Subject:

To:

From:

Approved: Registration Review -Ecological Risk, Environmental Fate, and Endangered Species Assessment for N,N-diethyl-meta-toluamide (DEET)

PC Code: 080301

DP Barcode: D399065

Susan Bartow, Chemical Review Manager

Anne Overstreet, Team Leader
Risk Management and Implementation Branch IV
Pesticide Re-evaluation Division (PRD)

Christine Hartless, Ph.D., Wildlife Biologist

James Lin, Ph.D., Environmental Engineer

Environmental Risk Branch 2
Environmental Fate and Effects Division

Office of Pesticide Programs

Jean Holmes, RAPL

# ~ Brian Anderson, Branch Chief 

# )'l (

1

### ~ n Environmental Risk Branch 2

Environmental Fate and Effects Division

Office of Pesticide Programs

The Environmental Fate and Effects Division (EFED) has completed the ecological effect,
environmental fate, and endangered species risk assessment to be conducted as part of the registration review of the insect repellant, N,N-diethyl-meta-toluamide (DEET). An evaluation

of environmental risk to aquatic and terrestrial organisms as a result of the use of DEET is

summarized in the Executive Summary and the Risk Characterization sections of the attached

document. A separate document containing a problem formulation was not prepared for DEET;
the problem formulation is contained within this risk assessment. At the present time, there are

no identified data needs for the currently registered uses ofDEET as an insect repellant.

There are no aquatic LOC exceedances based on low environmental exposure relative to DEET's toxicity to aquatic organisms. There are also no terrestrial risk concerns based on lack of a complete exposure pathway. In addition to effects on non-listed species, an assessment for

effects on listed species was also prepared. No direct or indirect effects for any taxonomic groups and no habitat modifications were identified for labeled uses ofDEET.

Page 1 of 41Page 2 of 41 

# Environmental Fate and Ecological Risk Assessment for the Registration
Review of N,N-diethyl-m-toluamide (DEET)

N,N-diethyl-m-toluamide (DEET) (CAS 134-62-3)

P

repared by: Christine Hartless, Ph.D., Wildlife Biologist James Lin, Ph.D., Environmental Engineer U. S. Environmental Protection Agency Office of Pesticide Programs

E nvironmental Fate and Effects Division

E nvironmental Risk Branch IV 1200 Pennsylvania Ave., NW

M

ail Code 7507P Washington, DC 20460 R eviewed by: Jean Holmes, RAPL Brian Anderson, Branch ChiefPage 3 of 41 Table of Contents

1. Executive Summary ............................................................................................................. ... 4

1.1. Nature of Chemical Stressor ............................................................................................ 4

1.2. Potential Risks to Non-target Organisms ......................................................................... 4

1.3. Conclusions - Exposure Characterization ........................................................................ 5

1.4. Conclusions - Effects Characterization ............................................................................ 6

2. Problem Formulation ........................................................................................................... ... 6
2.1 Conclusions from Previous Risk Assessments................................................................. 6

2.2. Nature of Regulatory Action ............................................................................................ 7

2.3. Stressor Source and Distribution ...................................................................................... 7

2.4. Conceptual Model ............................................................................................................ 9

2.5. Analysis Plan ................................................................................................................. . 11

2.6. Endangered Species Assessment .................................................................................... 15

2.7. Endocrine Disruptor Screening Program ....................................................................... 15 3. Analysis............................................................................................................. ................. 16

3.1. Exposure Characterization ............................................................................................. 16

3.2. Ecological Effects Characterization ............................................................................... 20

4. Risk Characterization ......................................................................................................... ... 23

4.1. Risk Estimation .............................................................................................................. 23

4.2. Risk Description ............................................................................................................. 25

4.3. Uncertainties and Data Gaps .......................................................................................... 25

5. Federally Threatened and Endangere d (Listed) Species Concerns ....................................... 26

5.1. Action Area ................................................................................................................... . 27
5.2. Taxonomic Groups Potentially at Risk .......................................................................... 27
6. References ................................................................................................................ ................ 29

Appendix A: Environmental Fate and Ecot oxicity Data Requirement Tables ............................. 31 Appendix B: Publically Available Data Table from EPA’s ECOTOX Database ....................... 35 Appendix C: Ecological Incident Reports ................................................................................... 39Page 4 of 41 

## 1. Executive Summary

1.1. Nature of Chemical Stressor

Registration review is being perf ormed for the insect repellent N,N-diethyl-m-toluamide (DEET, CAS Registry Number 134-62-3 , PC Code 080301). This document contains the problem
formulation as well as the environmental fa te, ecological risk, and endangered species assessments for its registered uses. This risk assessment is intended to identify ecological risks associated with the registered uses of DEET as an insect and tick repellent. In addition to the repellent registrations, DEET has se veral industrial uses, as both a resin solvent and as a surface plasticizer (Holsten and Neely 1993). These industr ial uses will not be evaluated in this risk

assessment.

DEET is a broad spectrum insect and tick repellent used on the human body and clothing (skin, hair, clothing, footwear, shoes, and headgear (caps)) as well as on horses (body treatment). DEET is used to repel biting flies, biting midges, black flies, chiggers, deer flies, fleas, gnats, horse flies, mosquitoes, no-see-ums, sand flies, stable flies, and ticks. DEET was registered in the United States in 1957 for use by the general public after first being developed by the U.S. Army in 1946 for use by military personnel in insect-infested areas (USE PA, 1998b). DEET is not registered for any agricultural, non-agricultural, or greenhouse applications. It is also not registered for any home, residential, or indoor applications in which the chemical is applied to surfaces other than human skin and hair, currently worn clothing, footwear, and headgear, or horse skin.

Currently, DEET is formulated as a microencapsula ted, pressurized spray (aerosol), as impregnated materials (e.g. towelettes, roll-on), and as a ready-to-use solution (non aerosol pump spray, liquid, cream, lotion, or foam). DEET concentrations in end-use products range from 5.0 to 98.25% a.i.



### 1.2. Potential Risks to Non-target Organisms

The results of this assessment on currently registered DEET uses indicate that there are no LOC exceedances to listed or non-listed non-target organisms ( Table 1.1 ). Additionally, the Agency
has determined that there is no habitat modifica tion of any designated critical habitat for listed species from the current registered uses of DEET.

Conclusions regarding aquatic organisms are base d on lack of acute LOC exceedances in the risk estimation. RQs were not calculated for aquatic plan ts as toxicity data were not available; EFED presumed direct risks were lower than concern le vels to aquatic plants given the mode of action of DEET and the large margin of safety obs erved for other aquatic taxonomic groups. In addition, no aquatic incidents have been reported. Conclusions regarding terrestrial organisms and plants are based on the lack of a complete exposure pathway. Exposure in terrestrial habitats would be limited to human skin, clothing, and shoe s, as well as horse sk in and hair. Products formulated as lotions or impregnated wipes woul d be applied directly to the human skin. Many other product labels specify recommended spray distances of less than 10 inches from the intended application sites (human skin, clothing, and shoes, as well as horse skin and hair).Page 5 of 41 Exposure to listed species is not expected because they would not likely come in close contact with humans or domestic horses ( i.e., the registered use sites). Ev en if a non-target organism were to come into contact with DEET from over-spr ay, exposure levels would be expected to be low; therefore, given its low toxicity profile, effects to non-target organisms would not be anticipated to exceed concern levels even if exposure occurred.

Table 1.1. Potential Effects to Federally Listed Taxa Associated with Direct or
Indirect Effects from the Currentl y Registered Uses of DEET.

Listed Taxon Direct Effects Indirect Effects

Terrestrial and semi-aquatic plants - monocots No No

Terrestrial and semi-aquatic plants - dicots No No

Birds No No Terrestrial-phase amphibians and reptiles No No

Mammals No No

Terrestrial invertebrates No No Aquatic nonvascular plants No No

Aquatic vascular plants No No

Freshwater fish No No Aquatic-phase amphibians No No

Freshwater invertebrates No No

Marine/estuarine fish No No

Marine/estuarine invertebrates No No



### 1.3. Conclusions - Exposure Characterization

DEET is expected to be moderate ly mobile in the soil column. In surface waters and soil, DEET is expected to degrade at a moderate to rapid rate (its half-life is measured in days to weeks).
The small amounts of DEET retained in air ar e subject to rapid photo-oxidation via hydroxy radical-mediated degradation with an estim ated half-life between 10 to 15 hours. The bioaccumulation potential of DEET is low; it is neither a persistent , bioaccumulative toxicant nor a persistent organic pollutant.

Aquatic exposure estimates for DEET are based on washoff after application to skin or clothing or to horses. Exposure estimates ranged from 0.005 to 0.42 mg a.i./L depending on the number of individuals entering a 20,000,000 L water body (standard farm pond). Surface water monitoring data based on multiple studies in dicated a median of 0.046 μg a.i./L, and a
90 th percentile of 0.4 μg a.i./L (Aronson et al ., 2011).

Exposure to terrestrial n on-target organisms and plants is ex pected to be inconsequential based on the labeled use patterns.Page 6 of 41 

### 1.4. Conclusions - Effects Characterization

Aquatic Organisms

Technical grade DEET is classifi ed as slightly toxic to fis h, aquatic-phase amphibians, and aquatic invertebrates on an acute exposure basis. Toxicity data were not available for evaluation of DEET chronic exposure to freshwater fish and invertebrates. No toxici ty data were available
for estuarine/marine fish and invertebrates or for vascular and non-vasc ular aquatic plants.

Terrestrial Organisms

DEET is slightly toxic to birds on an acute oral exposure basis and is pr actically non-toxic to mammals on an acute oral exposure basis. No diet ary or chronic toxicity data were available for birds. A two-generation laborat ory rat study resulted in an offs pring NOAEC = 500 mg/kg-diet based on decreased body weight in female pups; no frank reproductive effects were identified for parental survival, growth or reproduction. No toxi city data were availabl e for non-target insects or terrestrial plants.



## 2. Problem Formulation

The purpose of problem formulation is to provide the foundation for the environmental fate and ecological risk assessment for th e registration review risk asse ssment for the insect repellant,

DEET . The problem formulation sets the objectives for the risk assessment, establishes a risk hypothesis and conceptual model depicting potentia l risk, and provides a plan for analyzing the data and characterizing the risk associated with the uses of DEET (USEPA, 1998b).



### 2.1 Conclusions from Previous Risk Assessments

EFED has not conducted any ecological risk as sessments for DEET. The DEET Re-registration Eligibility Document (RED, si gned April 1998) stated that:

“Environmental risk assessments are not conducted for pesticides with exclusively indoor use patterns. N,N-diet hyl-m-toluamide (DEET) is considered
to be an "indoor residential" use rather than an outdoor use because it is only applied directly to the human body/cl othing, cats, dogs, pet quarters, and household/domestic dwellings. Application of DEET to these site s is not likely to adversely affect terrestrial w ildlife or aquatic organisms.

A limited set of toxicity data for indoor-u se pesticides is required to determine precautionary label statements and to a ssess environmental hazards in case of spills. The available data characterize DEET as slightly toxic to birds, fish, and aquatic invertebrates and as pr actically nontoxic to mammals.”Page 7 of 41 

### 2.2. Nature of Regulatory Action

The U.S. Environmental Protection Agency (EPA or the Agency) is required under the Federal Insecticide, Fungicide, and Rode nticide Act (FIFRA) to ensure that the currently registered pesticide DEET is re-evaluated for potential to cause any unreasonable adverse effects to the environment. In addition potenti al effects to listed species ( i.e. , species on the Federal list of endangered and threatened wildli fe and plants) and their designa ted critical habitat are also considered under the Endangered Species Act (ESA ) in order to ensure that the continued registration of DEET is not likely to jeopardize the continued existence of listed species or adversely modify their critical ha bitat. In order to meet the re quirements of FIFRA and the ESA, this assessment follows EPA guidance on co nducting ecological risk assessments (USEPA, 1998a).

The end result of the EPA pesticide registration review process ( i.e. , the FIFRA regulatory action) is a set of approved product labels. The la bel is a legal document that stipulates how and where a given pesticide may be used. Product labe ls (also known as end-use labels) describe the formulation type ( e.g. , liquid or granular), acceptable methods of application, approved use sites, and any restrictions on how applications may be conducted. Therefore, the use, or potential use, described by the pesticide’s labels is considered “the action” being assessed. This assessment was prepared to support evaluation of the registra tion review of DEET as an insect repellant;
industrial uses of DEET will not be evaluated in this risk assessment.



### 2.3. Stressor Source and Distribution

2.3.1. Nature of Chemical Stressor

DEET belongs to the chemical class of N,N-dial kylamides. The specific mechanism of action of DEET has not been determined. Early research conc luded that DEET interfer ed with receptors in mosquito (and other biting insects) antennae that detect L-lactic acid and carbon dioxide, the primary attractants emitted by humans and other an imals. Insects exposed to DEET are thereby unable to effectively locate a host (Davis et al ., 1976; McIver et al ., 1981; Snow, 1970). Later research indicated that DEET had a repellant e ffect on mosquitos with carbon dioxide as the only attractant, thus demonstrating that an inte raction between DEET and lactic acid was not necessary to repel mosquitoes (Boeckh, et al., 1996; Hoffmann and Miller, 2003). Recent mosquito behavior research sugge sts that repellency is due to direct detection of vapor phase DEET by the olfactory receptor neurons (ORNs) in the antenna (Syed and Leil, 2008). Bohbot and Dickens (2010) reported that DEET has both excitatory and inhibitory properties on odorant receptors (ORs) resulting in the scrambling of cognitive olfactory inputs and ultimately behavioral disruption.

2.3.2. Overview of Pesticide Usage

It has been previously estimated that approx imately 30% of the U.S. population uses DEET on their body and/or clothing annually as an insect and tick repe llent (USEPA 1998b). Based on current DEET registration and use information, ther e are a total of 123 ac tive registrations, 108 are DEET only and 15 are co-formulated with bo th MGK 326 (insecticide, PC Code 047201) andPage 8 of 41 MGK 264 (synergist, PC code 057001). Ten end-use pr oducts contain a suns creen in addition to DEET. Percent a.i. in the ready-to-use produc ts ranges from 5 to 98.25%. There is only one product registered for horse use, DEET Plus Com posite Insect Spray II (packaged in 4 oz can with 17.5% a.i.). The approved pests associated w ith DEET uses are: biti ng flies, black flies, chiggers, deer flies, fleas, gnats, mosquitoes, st able fly, ticks, no-see-ums, biting insects, biting midges, greenhead flies, horse flie s, mites, punkies, and sand flies. Application of DEET insect repellents to the skin and clothing can help prevent bites from mosquitoes, ticks and other vectors that may transmit diseases such as Lyme disease, West Nile virus, malaria, yellow fever, dengue fever, and encephalitis.

The physical forms of the registered products in clude: ready-to-use solution, pressurized liquid, impregnated materials, emulsifiable concentr ate, soluble concentrate, microencapsulated,
technical chemical and formulation intermediate . The approved use sites are human skin, human face area, human neck area, human clothi ng, human clothing footwear, human clothing headgear, shoes and horses. Us es supported at the time of th e 1998 RED but that are no longer
on current labels are households/domestic dwe llings, cats (adults/kittens), dogs/canines (adults/puppies), and pet living/sleeping quarters.

The following list provides representative directions for DEET end-use products:

 Sun Skeeter (Illinois Tool Works , Inc.) (reg# 11694-112: 20% ai). Remove towelette and unfold fully. For maximum protection, wipe evenly and completely over all exposed skin. Avoid overexposure; frequent reappl ication and saturation are unnecessary. Use just enough Sun Skeeter to cover exposed skin. After returning indoors, wash treated skin with soap and water or bathe. Remove and wash treated clothing be fore wearing it again.

 CUTTER Original Insect Repellent Pump Spray Formula MMI (Spectrum, United Industries) (reg# 121-34: 23% ai). For outdoor use only. Do not spray in enclosed
areas. Hold bottle 6 - 8 inches from skin and clothing while spraying, keeping sprayer pointed away from face. Slightly moiste n skin. Use just enough repellent to cover exposed skin and/or clothing. Do not us e under clothing. For maximum protection on skin, spread with hand after application. Fo r extra protection from ticks, chiggers and fleas, spray along all openings of clothing, such as neckband, waistband, pant and sleeve cuffs, sock tops and other areas where insects may crawl under clothing. Frequent reapplication or satu ration is unnecessary· A void over-application of this product. After returning indoors, wash treated skin with soap and water. Wash treated clothing before wearing it again.

 REPEL 15 (United Industries Corp .) (reg# 305-48: 15% ai). Hold container 6 to 8 inches from skin or clothing and spray w ith a slow sweeping motion. Do not spray in enclosed areas. Use just enough repellent to cover exposed skin a nd/or clothing. Do not use under clothing. Avoid over-application. Work s on clothing too: Spray shirts, pants, and hats. For ticks, chiggers and fleas apply to tops of socks and around openings of outer clothing. After returning indoors, wash treated skin with so ap and water. Wash treated clothing before wearing it again.

 Maximum Strength Pump Spray Deep Woods OFF! (S. C. Johnson & Son) (reg# 4822-276: 98.25% ai). Hold container upright 4 to 6 inches away from skin or clothing. Use just enough repellent to cover exposed skin and/or clothing. Avoid over-application of this product. Frequent r eapplication and satura tion are unnecessary. Spray shirts, pants,Page 9 of 41 socks, and hats. For ticks and chiggers al so spray cuffs, socks and around other openings in outer clothing.

 CUTTER Maximum Strength Insect Repelle nt Formula 100 (Spectrum, United Industries) (reg# 121 -25: 98.11% ai). For outdoor use only. Do not use in enclosed areas. To apply, put a few drops in palm of ha nd, rub palms together, then spread evenly over exposed skin. Use just enough repellent to cover exposed skin and/or clothing. Do not use under clothing. For extra protection from ticks, chiggers and fleas, apply along all openings of clothing, such as neck-band, wais tband, pant and sleeve cuffs, sock tops and
other areas where insects may crawl under clothing. Fr equent reapplication is unnecessary. Avoid ove r-application of this product. After returning indoors, wash treated skin with soap and water. Wash treated clothing before wearing it again.

 CCL Quick Breaking Insect Repellent Fo am (K-G Spray-Pak) (reg# 46813-46: 8.89% ai). Shake can well. Spray foam into palms of your hands and spread evenly on exposed areas of skin such as legs, arms , body, neck and face. Use just enough repellent to cover exposed skin and/or clothing. A void over-application of this product. After returning indoors, wash treated skin with soap and water. Wash treated clothing before wearing it again.



### 2.4. Conceptual Model

For a pesticide to pose an ecological risk, it must reach ecological receptors (a biological entity that is exposed to a stressor (USEPA, 1998a)) in biologically significant concentrations. An exposure pathway is the means by which a pesticid e moves in the environment from a source to an ecological receptor. For an ecological path way to be complete, it must have a source, a release mechanism, an environmental transpor t medium, a point of exposure for ecological receptors, and a feasible route of exposure.

The conceptual model for DEET provides a written description and visual representation of the predicted relationships between DEET, potential r outes of exposure, and th e predicted effects for the assessment endpoint. A conceptual model cons ists of two major components: risk hypothesis and a conceptual diagram (USEPA 1998a).

2.4.1. Risk Hypotheses

For the DEET national-level ecological risk asse ssment, the following ecological risk hypotheses are being employed: 1) DEET, when used in accordance with cu rrent labels, can result in off-site movement of the compound via washoff by treated individuals entering water bodies as well as from showering/bath ing and laundry leadi ng to exposure of non-target aquatic plants and animals in cluding federally-listed threatened and endangered species. 2) Direct applications of DEET to human skin, clothing, and horse skin are not expected to result in significant exposu re to non-target te rrestrial plants and animals including federally-listed threatened and endangered species.Page 10 of 41 2.4.2. Conceptual Diagram

The transport mechanism (washoff from treated i ndividuals by swimming, bathing, and laundry) that may result in the movement of DEET into aquatic (water and sediment) habitats is depicted in the conceptual model below ( Figure 2.1 ). Based on the use characteristics and environmental fate properties of DEET, runoff, spray drift, l eaching, and atmospheric deposition are unlikely to result in aquatic or terrestrial exposures to non-target plants and organisms. For DEET, the only potential exposure pathway is wa shoff from skin and clothing when treated individuals enter
recreational water bodies or tr eated individuals bathe themse lves or launder clothing.

Exposure in terrestrial habitats would be limited to human skin, clothing, and shoes, as well as
horse skin and hair. Products formulated as lo tions or impregnated wi pes would be applied directly to the human skin. Many other product la bels specify recommended spray distances of
less than 10 inches from the inte nded application sites (human ski n, clothing, and shoes, as well as horse skin and hair). Any m ovement away from the site of application represents potential exposure pathways for a broad range of biological receptors of concern (non-target terrestrial animals and plants) and the potential attribute changes, i.e. , effects such as reduced survival, growth and reproduction, in the receptors due to DEET exposure. The amount of DEET resulting from human or horse application in the terrestr ial environment (air, groun d, plants, or non-treated animals) is inconsequential. As there is no co mplete exposure pathway, a conceptual diagram for terrestrial exposure and effects was not included in this assessment.Page 11 of 41 Figure 2.1. Conceptual model for DEET effects on aquatic organisms. Dotted lines indicate exposure pathways that have a low likelihood of contributing to ecological risk.



### 2.5. Analysis Plan

In order to address the risk hypot hesis, the potential for advers e effects on the environment is estimated. The use, environmental fate, and ec ological effects of DEET are characterized and integrated to assess the risks. This is accomp lished using a risk quotient (ratio of exposure
concentration to effects concentr ation) approach. Although risk is often defined as the likelihood and magnitude of adverse ecological effects, the risk quotient-based approach does not provide a quantitative estimate of likelihood and/or magnit ude of an adverse effect. The likelihood of effects to individual organisms fr om particular uses of DEET is estimated using the probit doseresponse slope and either the level of concern (d iscussed below) or actual calculated risk quotient
value. 

### Stressor

Source

Receptors

Attribute Change DEET applied to use site (humans or horses)

Spray drift

Fish/aquatic-phase amphibians Eggs

Larvae
Juveniles / Adults

Individual organisms
Reduced survival Reduced growth Reduced reproduction Food chain Reduction in algae Reduction in prey Habitat integrity Reduction in primary productivity
Reduced cover Community change Surface water/

Sediment Runoff

Aquatic Animals
Invertebrates

Vertebrates 

### Exposure
Media

Uptake/gills or integument

In g estion In g estion Soil Groundwater

Uptake/gills or integument

Aquatic Plants

N on-vascular

Vascular Uptake/cell, roots, leaves Atmos p here WashoffPage 12 of 41 2.5.1. Residues of Concern

The parent compound, DEET, is the toxicant that will be assessed. Toxicity of DEET isomers and degradates will be assumed to be equivalent to parent compound in the absence of data to suggest otherwise.

2.5.2. Evaluation of Multiple Active Ingr edients, Mixtures and Formulated
Products

The Agency does not routinely include in its risk assessments an evaluation of mixtures of active ingredients, either those mixtures of multiple ac tive ingredients in product formulations or those in the applicator’s tank. In th e case of the product formulations of active ingredie nts (that is, a registered product containing more than one active ingredient), each active ingredient is subject to an individual risk assessment for regulator y decision regarding the active ingredient on a particular use site. If effects data are available for a formulat ed product containing more than one active ingredient, they may be used qualitatively or quantitatively.

2.5.3. Measures of Exposure

The ecosystems potentially at risk are often extens ive in scope; therefore, it may not be possible to identify specific ecosystems during the de velopment of a nation-wide ecological risk

assessment.

Aquatic ecosystems potentially at risk from DE ET exposure include water bodies adjacent to, or downstream from, the water bodies that were ente red by treated humans or horses. In order to estimate risks of DEET exposures in aquatic environments, all exposure modeling and resulting risk conclusions will be based on maximum appli cation rates and methods. Measures of aquatic exposure are typically based on models that pr edict estimated environm ental concentrations (EECs) of DEET such the Pesticide Root Zone Model coupled with the Exposure Analysis Modeling System (PRZM/EXAMS). Because of th e limited application methods (directly to human skin, clothing, shoes, and horse skin), th e typical models used for exposure estimation
will not be used in this assessment. It wa s assumed that DEET reaches surface water by application to humans or horses and the treate d individuals enter the water body, and the applied DEET is then presumed to wash off the treated humans or horses and remain in the water column. Water concentrations in the standard po nd will be calculated under the assumption of 10 treated adults, 100 treated adults, 50 cans of product, or 10 treated horses entering the water body on a single day. Given the small size of the modeled water body, 10 and 100 swimming adults represent low and moderate aqua tic exposures. Applic ation of the equiva lent of 50 cans of product represents a highly unlikely, very conser vative aquatic exposure scenario, as it is not expected that such a large num ber of treated individuals woul d enter a single 1–hectare water body within a 24 hr period. The scenario is pres ented as a convenient me asure to evaluate the plausibility of exposure levels approaching those that may cause concern for aquatic organisms. DEET application to ten horses that enter a wate r body also represents a high exposure scenario for the horse use pattern.Page 13 of 41 Because of the application method and limited scope of use sites for DEET, terrestrial ecosystems potentially at risk could include the area in which treatment (application to human or horse) occurred. Exposure to non-targ et terrestrial organisms and pl ants is presumed negligible ( Section 2.4.2 ) and will not be estimated.

2.5.4. Measures of Effect

Measures of effect are obtained from a suite of registrant-submitted guideline studies that were
conducted with a limited number of surrogate test species ( Table 2.1) . Toxicity data generated using surrogate test species, which are intended to be representative of broad taxonomic groups, are used to infer potentia l effects on a variety of species (receptors) incl uded under these broader taxonomic groupings. Birds repres ent surrogates for terrestrial- phase amphibians and reptiles, and freshwater fish represent surrogates for aq uatic-phase amphibians. No additional non-target ecotoxicity data on DEET were located, based on a May 2012 query of the open literature in the publically available version of the ECOTOX database (http://c fpub.epa.gov/ecotox/).

Table 2.2 lists the measures of environmental exposur e and ecological effects used to assess the potential risks of DEET to non-target organi sms. Assessment endpoints represent the actual environmental value that is to be protected, de fined by an ecological entity (species, community, or other entity) and its attribut e or characteristics (USEPA, 1998a). The attributes for each of these entities may include grow th, survival, and reproduction.Page 14 of 41 Table 2.1. Measures of Exposure and Measures of Effect Used in Assessing Potential Risks Associated with the Regi stered Uses of DEET.

Assessment Endpoint Surrogate Species and Measures of Ecological Effect 1 Measures of Exposure

Aquatic Animals (Freshwater fish and invertebrates) 2 Survival Lowest tested LC 50 or EC 50 (acute toxicity test) estimated aquatic
concentrations after
treated individuals entered water body

Reproduction
and Growth No data Not calculated as no acute
LOC exceedances and no chronic toxicity data
available

Aquatic Animals (Estuarine/marine fish

and invertebrates) 2 Survival No data Presumed concentrations in water equal or less than
those estimated for small freshwater pond

Reproduction
and Growth No data Not calculated as no acute
LOC exceedances and no chronic toxicity data
available

Aquatic plants Growth No data estimated aquatic
concentrations after
treated individuals entered water body

Birds 3 Survival Lowest acute LD 50 (single oral dose test)

No LC 50 (dietary exposure) data available

Not calculated as no exposure expected Reproduction
and Growth No data

Mammals Survival Lowest acute LD 50 (single oral dose test)
Reproduction
and Growth Lowest NOAEC for frank reproductive effects (2-generation reproduction test)

Insects Survival No data Not calculated as no exposure expected

Terrestrial plants Survival and growth No data Not calculated as no exposure expected

1 The most sensitive species tested within taxonomic gr oups is used for screening-level risk assessments.

2 Freshwater fish are considered su rrogates for aquatic-phase amphibians.

3 Birds are considered surrogates for te rrestrial-phase amphibians and reptiles.

2.5.6. Integration of Exposure and Effects

Exposure and toxicity data are in tegrated in order to evaluate the risks of adverse ecological effects on non-target species. For the screening- level risk assessment of DEET, the deterministic risk quotient (RQ) method is used to compare es timated exposure concentrations with measured toxicity values. The RQ method involves di viding point estimates of environmental concentrations by acute and chronic toxicity values. The resulting unitless RQs are then compared to the Agency’s Levels of Concern (LOC) ( Table 2.2 ). These criteria are used to indicate when applications of DEET, as direct ed on the proposed labels , have the potential to
cause adverse effects to listed a nd non-listed non-tar get organisms.Page 15 of 41 Table 2.2. Agency Acute Risk Quotient (RQ) Metrics and Le vels of Concern (LOC) for Aquatic Animals (fish and invertebrates)

RISK CLASS RISK DESCRIPTION RQ LOC

Acute Potential for effects to non-listed animals from acute

exposures Peak EEC/LC 50 1 0.5

Acute Restricted Use Potential for effects to an imals from acute exposures Risks may be mitigated through restricted use
classification Peak EEC/LC 50 1 0.1

Acute Listed Species Listed species may be potentially affected by acute

exposures Peak EEC/LC 50 1 0.05

1 LC 50 or EC 50

.



### 2.6. Endangered Species Assessment

Consistent with the Agency’s responsibility under the Endangered Sp ecies Act (ESA), the Agency evaluates risks to Federally-listed threat ened and/or endangered (listed) species from registered uses of DEET.

The assessment of effects associated with the registration of DEET 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 LOCs used to evaluate direct or indirect effects. The action area is defined using the results of the risk assessment to establish bound aries for that action area with the understanding that exposures below the Agency’s defined LOCs constitute a no-effect threshold. For the purposes of this assessment, attention will be focused on the footprint of the action ( i.e ., the area where DEET app lication occurs), plus all areas where offsite transport may result in potential exposure that exceeds the Agency’s LOCs. Specific measures of ecological effect that define the action area for listed species include any direct and indirect effects and/or potential modificat ion of its critical habitat, including reduction in survival, growth, and reproduction as well as the full suite of sub-lethal e ffects available in the effects literature. Therefore, the action area extends to a point where environmental exposures are below any measured lethal or sub-lethal effect thre shold for any biological entity at the whole organism, organ, tissue, and/or cellular level of organization. In situations where it is not possible to determine the threshold for an observed effect, the action area is not spatially limited
and is assumed to be the entire United States. The action area for DEET will be determined in
Section 5.1

.



### 2.7. Endocrine Disruptor Screening Program

As required under FFDCA sec tion 408(p), EPA has develope d the Endocrine Disruptor Screening Program (EDSP) to determine whether certain substances (inc luding pesticide active and other ingredients) may have an effect in hu mans or wildlife similar to an effect produced by a “naturally occurring estrogen, or other such endocrine eff ects as the Administrator mayPage 16 of 41 designate.” The EDSP employs a two-tiered approach to making the statutorily required determinations. Tier 1 consists of a battery of 11 screening assays to identify the potential of a chemical substance to interact with the estrogen, androgen, and or thyroid (E, A, or T) hormonal systems. Chemicals that go through Tier 1 scre ening and are found to ha ve the potential to interact with E, A, or T hormonal systems will pr oceed to the next stage of the EDSP where EPA will determine which, if any, of the Tier 2 tests are necessary based on the available data. Tier 2 testing is designed to identify a ny adverse endocrine related effects caused by the substance, and establish a dose-response relationship between the dose and the E, A, or T effect.

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

DEET is not among the group of 58 pesticide active ingredients receiving EDSP test orders. For
information on the status of the orders issued under the EDSP for each chemical, please visit our website at http://www.epa.gov/endo/ and click on the "Status of EDSP Orders/DCIs" in the Highlights Box. Additional info rmation on the EDSP, including th e policies and procedures, the list of 67 chemicals, the test guid elines and the Tier 1 screening battery, can al so be found at this
website.



## 3. Analysis

3.1. Exposure Characterization

3.1.1. Environmental Fate and Transport Characterization

DEET is an all-purpose insect repellent which c ontains a minimum of 95% of the meta isomer, the most effective form of diethyl toluamide, as a technical ingr edient. The technical DEET is a nearly colorless liquid with a fain t characteristic odor. It is re latively stable, highly hygroscopic and sensitive to light. It is practically insolubl e in glycerin but miscible with several organic
solvents.

The physicochemical characteristics asso ciated with DEET are summarized in Table 3.1 ; the parameter values are from Weeks, et al. (2011).Page 17 of 41 Table 3.1. Physicochemical properties of DEET

Parameter Value Method

Molecular formula C 12 H 17 NO
Molecular weight 191.3 g/mol calculated

Density 1.01 kg/L @ 20 o C

1.02 to 0.998 kg/L @ 20 o C OECD 109
ISO 1183, Method 3

Water solubility 2072 mg/L@ 20 o C 11200 mg/L @ 25 o C OECD 105

EPA 830.7840

Vapor pressure 0.00013 mm Hg @ 25°C

0.017 Pa @ 25°C OECD 104

EPA 830.7950
Henry’s law constant 3.4 x 10 -8 atm-m 3 /mol calculated
Octanol-water partition coefficient (log K

ow ) 2.02

2.4 OECD 107

EPA 830.7570

Bioconcentration factor (BCF) in fish 22 L/kg 13.3 L/kg Regression w/ log K

ow EPISuite v4.10

Soil sorption coefficient (K

oc ) 47 to 126 L/kg 43.3 L/kg OECD 106 (5 soils)

OECD 121

The only environmental fate study submitted to the Agency is the hydrolysis study (MRID 40192701). The study demonstrated that DEET is st able to hydrolysis in solutions initially buffered to pH 5, 7, and 9. It can be concluded that DEET will be stable to hydrolysis at pH
levels found in the environment.

Based on the information from Weeks et al. (2011) presented in Table 3.1 , DEET is expected to be moderately mobile in the soil column. In surface waters and soil, DEET is expected to degrade at a moderate to rapid rate (its half-l ife is measured in days to weeks). The small
amounts of DEET retained in ai r are subject to rapid phot o-oxidation via hydroxy radicalmediated degradation with an estimated half-l ife between 10 to 15 hours. The bioaccumulation potential of DEET is low; it is neither a pers istent, bioaccumulative toxicant nor a persistent organic pollutant according to European Union (EU) re gulatory PBT criteria (KemI 2010; Weeks et al. 2012).

3.1.2. Estimated Surface Water Concentrations of DEET

In order to estimate risks of DEET exposures in aquatic envi ronments, all exposure modeling and resulting risk c onclusions will be based on maximu m application rates and methods. Measures of aquatic exposure are typically base d on models that predict estimated environmental concentrations (EECs) of DEET such the Pestic ide Root Zone Model coupled with the Exposure Analysis Modeling System (PRZM/EXAMS). Because use is restricted to direct application to human skin, clothing, shoes, and horse skin, the typical models used for exposure estimation will
not be used in this assessment.

Aquatic exposure could be expected via two rout es: (1) washoff from tr eated skin and clothing when people or horses enter water bodies and (2 ) washoff from treated skin and clothing when people bathe or launder clothing. EFED estimated DEET water concentrations after people or horses entered a water body using the approach de tailed below. DEET “down-the-drain” waterPage 18 of 41 concentrations (result of bathing and laundry) co uld be estimated using the EPA E-FAST model ( http://www.epa.gov/opp t/exposure/pubs/efast.htm ). Monitoring data indicated that DEET may be present in effluent ( Section 3.1.3 ); however, the aquatic exposure assessment methods utilized for exposure from treated humans and ho rses swimming in water bodies are expected to account for peak and high-end EECs and would be protective of any potential “down-the-drain”

exposure.

Two end-use products for humans containing the highest quantity of DEET in single sale containers and the end-use product registered for use on horses will be evaluated for potential aquatic exposure. Super Guard Insect Repellan t (EPA Reg. No. 54287-2) is 98.11% a.i. and sold in a 6 oz ready-to-use solution pump spra y. PIC X-100% DEET (EPA Reg. No. 30950-27) is 98.11% a.i. and sold in a 6 oz ready-to-use pres surized liquid-aerosol spray. Since the density of DEET is 0.996 g/l, fluid ounces are approximately e qual to ounces as a unit of weight. Therefore, both 6 oz packages contain approximate ly 167,000 mg DEET. The only end-use product registered for use on horses is DEET Plus Co mposite Insect Spray II (EPA Reg. No. 54287-13, 17.5% a.i.), and it will also be evaluated.

The standard scenarios used fo r ecological pes ticide assessments assume application to a 10- hectare agricultural field that drains into an ad jacent 1-hectare water body that is 2 meters deep (20,000 m 3 volume equivalent to 20,000,000 L) with no outlet. PRZM /EXAMS is typically used to estimate screening-level exposure of aquatic organisms through runoff and drift. In this assessment, it was assumed that DEET reaches su rface water by application to humans or horses
and the treated individuals ente r the water body. The applied DEET is then presumed to wash off
the treated humans or horses and then remain in the water column. Water concentrations in the standard pond will be calculated under the assumption of 10 treated adults, 100 treated adults, 50 cans of product, or 10 treated horses entering the water body on a single day. Given the small size of the modeled water body, 10 and 100 swimmi ng adults represent a range of possible exposure scenarios, although an assumption of 100 swimming adults is conservative. Application of the equivalent of 50 cans of product represents a highly unlikely, very conservative aquatic exposure scenario, as it is no t expected that such a large number of treated individuals would enter a singl e 1–hectare water body within a 24 hr period. DEET application to ten horses also represents a high ex posure scenario for th e horse use pattern.

The Standard Operating Procedures for Residen tial Pesticide Exposure Assessment developed by the Health Effects Division (H ED) provide methods for assessm ent of pesticide exposures unrelated to employment or dietary intake of food or water (USEPA, 2012). Exposure
assessment methods in this document include scenarios reflecting i ndividuals who purchase pesticides and complete their own applications , such as adult and child application rate calculations for insect repella nts. Of the different availa ble application methods and concentrations of DEET in the individual product s, pump sprays and aerosol sprays provide the highest application rates per individual. HED’s methodology determines an applied dose (mg a.i./kg-day) as well as an absorbed dose (mg a.i./kg-day); however for the purposes of this aquatic exposure estimation, the applied dose will be used and converted to a total daily dose per individual using an average adult body weight of 80 kg:Page 19 of 41 D = AR F * F AI

* ET * AppF * SA/BW * F Body * BW

where:

D = dose (mg/individual-day);

AR F = formulation-specific app lication rate (mg product/cm 2 skin);

F AI = product-specific fraction of activ e ingredient (mg ai/mg product); ET = exposure time (hours/day); AppF = application freque ncy (applications/hour); SA/BW = total body surface area to body weight ratio (cm 2 /kg);

F Body = clothing-dependent fraction of body e xposed (fraction exposed/application); BW = 80 kilograms.

For adult human applications, AR F , ET, AppF, SA/BW, F Body , and BW were determined using
default values from HED’s SOP. For horse s, the SA/BW and BW values were 100 cm 2 /kg and 500 kg, respectively ( http://www.rd1.com/lifestyle/horse-a rticles/summer-feeding-strategies ). Using the high concentrations of end-use products for humans (98% a.i.), adult individuals were treated with 9453 or 16771 mg a.i./day for pump and aerosol sprays, respectively ( Table 3.2 ).
Individual horses were treate d with 3764 mg a.i./day assumi ng the same fraction coverage, application intervals, and exposure time as humans.

Under the assumption that 10 adults, 100 adul ts, or 10 horses ente red a 20,000,000 L waterbody and all the applied DEET washed off skin/hair/cl othing and was instantaneously mixed into the waterbody, the resulting concentrations of D EET in the water ranged between 0.002 and 0.08 mg a.i./L ( Table 3.3 ). If the equivalent of 50 containers of product (6 oz of 98% a.i.) were instantaneously mixed in the 20,000,000 L water body, the resulting DEET concentration was calculated to be 0.42 mg a.i./L. These scenarios result in conservative screening level exposure estimates for aquatic organisms.

Table 3.2. Calculations for determining mg a.i./individual/day for DEET spray treatments.

Repellent
without

sunscreen Amount
of ai in product (mg ai/mg product) Formulationspecific AR (mg product/cm 2
skin) Fraction Body Exposed SA to BW
Ratio (cm 2 /kg) Exposure
Time (hr/day) Application Frequency

(#/hr) Exposure(mg a.i./kgday) a Exposure (mg a.i./
individual/ day) b

Human (pump spray) 0.98 0.62 0.75 280 3.7 0.25 118 9453

Human (aerosol spray) 0.98 1.10 0.75 280 3.7 0.25 210 16771

Horse (pump spray) 0.18 0.62 0.75 100 3.7 0.25 7.5 3764

a Exposure calculated by multiplying the values in the pr eceding six columns (see Standard Operating Procedures for Residential Pesticide Exposure Assessment at http://www.epa.gov/pesticides/science/residential-exposuresop.html#sops for details).

b Individual exposure calculated by multiplying estimated body weight (80 kg for adult humans and 500 kg for horses) by exposure (mg a.i./kg-day) from the preceding column.Page 20 of 41 Table 3.3. Aquatic exposure estimates of DEET (mg a.i./L)

End-use product % a.i. Total application Total mg a.i. mg a.i./L in pond a

SUPER GUARD INSECT

REPELLENT (EPA Reg. No. 54287-2),

pump spray 98.11 10 adults 94,530 0.005

100 adults 945,300 0.05

50 cans product 8,344,355 0.42

PIC X-100% DEET (EPA Reg. No. 3095-27), aerosol spray 98.11 10 adults 167,710 0.008

100 adults 1,677,100 0.08

50 cans product 8,344,355 0.42

DEET PLUS COMPOSITE

INSECT SPRAY II (EPA Reg. No. 54287-13), aerosol spray 17.5 10 treated horses 37,600 b 0.002

a Pond volume of 20,000,000 L.

b Calculated using same approach as for adult huma ns except surface area to body weight ratio was 100

cm 2 /kg and body weight was 500 kg (http://www.rd1 .com/lifestyle/horse-articles/summer-feedingstrategies).

3.1.3. Surface Water Concentrations of DEET Based on Monitoring

Available monitoring data is used to qualita tively characterize exposure and compare with modeling results. Surface water concentrations in the United States and elsewhere are reviewed and evaluated by Aronson et al. (2011). The distribution of DEET concentrations from multiple monitoring studies of wastewater effluents, and streams, and rivers was found to have a median of 0.046 μg/L and a 90 th percentile of 0.4 μg/L. The expect ed concentrations across the United States depend on the geographical distribution of population, and the factor s affecting dilution of DEET residues as they travel in wastewater. The locations of waste water treatment plants (WWTPs), their effluent volumes , population served, and the netw ork of receiving streams are all known to a relatively good degree for the United States. These data are contained in databases made available by the USEPA and USGS. Aronson et al . (2011) used two publicly available modeling systems (E-FAST and iSTR EAM) to predict the pattern of DEET concentrations expected throughout the United States. The results show that the known repellent
use of DEET is consistent with the observed dist ribution of concentrations seen in monitoring
studies.

3.1.4. Estimates of Terrestri al Exposure to DEET

Exposure to non-target terres trial organisms and plants is presumed negligible ( Section 2.4.2 )
and will not be estimated.



### 3.2. Ecological Effects Characterization

In screening-level ecological risk assessments, effects characterization describes the types of effects a pesticide can have on aq uatic and terrestrial organisms. To date, toxicity tests forPage 21 of 41 amphibian or reptiles are not re quired; birds are used as surroga tes for reptiles and terrestrialphase amphibians and freshwater fish are used as surrogates for aquatic-phase amphibians. This characterization is based on the registrant-submitted toxicity data for birds, mammals, fish, and
invertebrates.

This assessment evaluates the potential for DEET to directly or indirectly a ffect listed species or modify designated critical habitat. As previously discussed in Section 2.5 , assessment endpoints may include direct toxic effects on the survival, reproduction, and growth of listed entities, as well as indirect effects, such as reduction of the prey base or modi fication of habitat. In addition, potential modification of criti cal habitat is assessed by eval uating effects to the primary constituent elements (PCEs), which are component s of the critical habita t areas that provide essential life cycle needs of listed entities.

The most sensitive endpoint for each taxon is us ed for risk estimation. For this assessment, evaluated taxa include freshwater fish (surro gate for aquatic-phase amphibians), freshwater invertebrates, birds (surrogate for terrestria l-phase amphibians and reptiles), and mammals.
Table 3.4 provides a summary of the taxonomic groups and the surrogate species tested to characterize the potential acute and chronic ecological effect s of DEET. In addition, the table provides a preliminary overview of the potential acute toxicity of DEET by providing the acute toxicity classifications.

Table 3.4. Test Species Evaluated for Assess ing Potential Ecologica l Effects of DEET and the Associated Acute Toxicity Classification.

Taxonomic Group Tested Species and Study Type Toxicity Endpoint Study MRID and Toxicity
Classification

Birds 1 Bobwhite quail ( Colinus virginianus ) (acute oral) LD 50 = 1375 mg a.i./kg-bwt 41159701 (acceptable) Slightly toxic

Avian dietary No data --

Avian reproduction No data --

Mammals Laboratory rat ( Rattus norvegicus ) (acute oral) LD 50 = 3900 mg a.i./kg-bwt 41678101 (acceptable 3 )Practically nontoxic

Laboratory rat (2-generation) Offspring NOAEC = 500 ppm (NOAEL = 2.5 mg/kg-bw) based on LOAEC of 2000 ppm for decreased body weight in female pups. No frank reproductive effects were identified for parental survival, growth or reproduction ( i.e ., parental and reproductive NOAEC = 5000 ppm; NOAEL = 250 mg/kg-bw) 40979001

Insects Honey bee No data --

Freshwater fish 2 Rainbow trout ( Oncorhynchus mykiss ) LC 50 = 75 mg a.i./L 00001026 (acceptable) Slightly toxic

Freshwater
invertebrates Daphnia magna EC 50 = 75 mg a.i./L 00243419 (acceptable) Slightly toxicPage 22 of 41 Table 3.4. Test Species Evaluated for Assess ing Potential Ecologica l Effects of DEET and the Associated Acute Toxicity Classification.

Taxonomic Group Tested Species and Study Type Toxicity Endpoint Study MRID and Toxicity
Classification

Estuarine/marine
fish No data --

Estuarine/marine

invertebrates No data --

Terrestrial plants No data -- Aquatic plants and algae No data --

1 Birds are considered surrogates for terr estrial-phase amphibians and reptiles.

2 Freshwater fish are considered su rrogates for aquatic-phase amphibians.

3 Study classification made by Health Effects Division (HED).

3.2.1. Effects to Aquatic Organisms

Technical grade DEET is classifi ed as slightly toxic to fis h, aquatic-phase amphibians, and aquatic invertebrates on an acute exposure basis. Toxicity data were not available for evaluation of DEET chronic exposure to freshwater fish and invertebrates. No toxici ty data were available
for estuarine/marine fish and invertebrates or for vascular and non-vasc ular aquatic plants.

3.2.2. Effects to Terrestrial Organisms

DEET is slightly toxic to birds on an acute oral exposure basis and is pr actically non-toxic to mammals on an acute oral exposure basis. No diet ary or chronic toxicity data were available for birds. A two-generation laboratory rat study resulted in an offspring NOAEC = 500 ppm (NOAEL = 2.5 mg/kg-bw) based on LOAEC of 2000 ppm for decreased body weight in female pups and no frank reproductive effects were identified for pa rental survival, growth or reproduction ( i.e ., parental and reproductive NOAEC = 5000 ppm; NOAEL = 250 mg/kg-bw; MRID 40979001).

No DEET toxicity data were availa ble for bees, non-target insects, or terrestrial plants. Given the mode of action of DEET, it is likely that many terrestrial invertebrates would be repelled from exposures to DEET.

3.2.4. Degradate toxicity

Based on the only available submitted environm ental fate study, DEET will be stable to hydrolysis at pH levels found in the environment. Therefore no degradat es were identified in that study. The open literature id entified the possible degradates including: 3-methylbenzoate and diethylamine. Given the lack of inform ation on degradates, in cluding their toxicity, degradates will be presumed to have the same toxicity as the parent.Page 23 of 41 3.2.5. ECOTOX Open Literature

Literature identified in the search of the pub lically available ECOTOX database resulted in several additional citations ( Appendix B ). The cited aquatic toxicity data did not provide endpoints that were more sensitive than the data that was submitted to the Agency. In addition, none of the aquatic data filled existing data gaps (e.g., chronic toxicity, estuarine/marine fish and invertebrate toxicity).

The cited terrestrial toxicity data did not either provide endpoints that were more sensitive than endpoints of submitted studies or fill existing data gaps for birds, mammals, or plants. One study evaluating the toxicity of DEET to mites was identified in the publically av ailable ECOTOX database; however, no studies on non -target insects were available.

Jeong et al. (2008) (ECO TOX# 102656) evaluated the toxicity of Thymus vulgaris oil, its main components, DEET, and benzyl benzoate, to the Tryophagus putrencentiae , as stored food mite. A fabric disk bioassay (test mate rial was dissolved in acetone and applied to disks of black cotton fabric) was used. Treated fabric was placed in a petri dish (covering the bottom), mites were added, and a lid was placed on top. Treated and control mite s were held in the dark for 24 hours; mortality was then assessed. The resulting LD 50 for DEET was 13.7 μg/cm 2 with a 95% confidence interval of (13.1, 14.7). The exposure in tensity and duration e xperienced by the mites in this study is not comparable to the potential exposures based on currently registered uses of

DEET.



## 4. Risk Characterization

4.1. Risk Estimation

Toxicity data and exposure estimates are used to evaluate the potential for adverse ecological effects on non-target species. This assessment for DEET relies on the deterministic RQ method to provide a metric of potential risks. The RQ provides a comparison of exposure estimates to toxicity endpoints ( i.e. , the estimated exposure concentrations are divided by acute and chronic toxicity values). The resulting unitless RQs are compared to the Agency’s LOCs, as shown in
Table 2.3 . LOCs are used by the Agency to indicate wh en the use of a pesticide, as directed by the label, has the potential to cause a dverse effects to non-target organisms.

4.1.1. Aquatic Organisms

The screening-level aquatic EECs based on the application rates for highest concentration products for human use and the onl y product registered for horse us e. The exposure estimates, representing concentrations in surface water, a nd toxicity data were us ed to calculate RQs ( Table
4.1 ). The expected concentratio ns of DEET in the aquatic envi ronment are several orders of magnitude lower than the available aquatic LC 50 and EC 50 s determined for DEET, and thus the potential for adverse risks is low.Page 24 of 41 Table 4.1. Aquatic exposure estimates and RQs for DEET

End-use product % a.i. Total application mg a.i./L in pond RQ for fish and
invertebrates 1,2

SUPER GUARD INSECT REPELLENT (EPA Reg. No. 54287-2), pump spray 98.11 10 adults 0.005 0.00007

100 adults 0.05 0.0007 50 cans product 0.42 0.006

PIC X-100% DEET (EPA Reg.

No. 3095-27), aerosol spray 98.11 10 adults 0.008 0.0002

100 adults 0.08 0.002 50 cans product 0.42 0.006

DEET PLUS COMPOSITE INSECT SPRAY II (EPA Reg.

No. 54287-13), aerosol spray 17.5 10 treated horses 0.002 0.00003

1 LC50 for rainbow trout and EC50 for daphids = 75 mg a.i./L; therefore, calcula ted RQs will be identical.

2 Acute risk to non-listed species LOC for aquatic organisms is 0.5 Acute risk to listed species LOC for aquatic organisms is 0.05

4.1.2. Incident Database Review

A review of the following databases was completed on May 29, 2012:

 Ecological Incident Information System (EIIS),

 ‘Aggregate Incident Reports’ database,

 Avian Monitoring Information System (AIMS, http://www.abcbirds.org/abcprogra ms/policy/toxins/aims/aims)

 Contaminant Exposure and Effects – Terrestrial Vertebrate (CEE-TV, http://www.pwrc.usgs.gov/contaminants -online/pages/CEETV/CEETVintro.htm). Incident reports are attached in Appendix C . One incident was listed in the EIIS database and one incident was listed in the Aggregate Incident Report database. No additional incidents for
DEET were identified in the AI MS or the CEE-TV databases.

One wildlife incident was reported in the EIIS database (I024160-001). A juvenile, female screech owl was brought to the Wildlife Dise ase Laboratory in East Lansing, Michigan, on November 10, 2003. The necropsy report indicated the bird was in good physical condition with the exception of blood-tinged mucoid material subcutaneously on th e flank and lower back areas. The ventriculus contents (one be etle and non-descript food material ) were analyzed for toxicants and a positive result was reported for DEET. The measured DEET concentration and the level of detection were not reported based on the GC/MS sc reen, and the list of other chemicals included in the screen was not provided. The written desc ription of “blood-tinged mucoid material” may suggest hemorrhaging due to anticoagulants, but the report does not state that anticoagulants were included in the toxicity screen conduc ted on the screech owl. Chemicals, including anticoagulants, which have been detected by th is laboratory are provided at the following link ( http://www.animalhealth.msu.edu/s ections/toxicology/WEBCD.TOX.REF.001.pdf ). The necropsy report concluded with a diagnosis of “Poi soning, Deet (Possible).” The legality of the use ( i.e., registered use or misuse) is unknown. EFED believes that the toxi cological properties of the chemical and the low expos ure potential based on regi stered uses suggest that it is unlikely that legal use of DEET caused the mortality of this screech owl.

One minor wildlife incident for DEET (specific product not reported) was identified in the Aggregate Incident Report database was reported to have occurred between July 1, 2002, andPage 25 of 41 September 30, 2002, by the registrant, SC Johns on (I013475-56). No information regarding species, number of individua ls, geographic region, habitat, likelihood of exposure, etc., was included in the report. Because of the lack of information, the EPA cannot assess the likelihood that DEET was indeed the cause of the alleged adverse effect to wildlife. Based on the low toxicity and limited exposure potential of DEET, as well as the limited information provided in the aggregate report, this reported incident is not adequate to dem onstrate the potential for risk to wildlife from registered DEET use.



### 4.2. Risk Description

4.2.1 Exposure and Risk to Aquatic Organisms

The results of risk estimation indicate that re gistered uses of DEET will not result in LOC
exceedances for acute risk to fish and invertebra tes. Chronic RQs were not calculated; however, given the large margin of safety observed for acute effects based on the most conservative exposure scenario, it is unlikely that chroni c RQs would approach concern levels.

RQs were not calculated for aquati c plants as toxicity data were not available. EFED presumed
direct risks were lower than concern levels to aquatic plants given the mode of action of DEET and the large margin of safety demonstrated fo r other aquatic organism s. Also, there are no reported incidents for aquatic organisms or plants.

4.2.2 Risks to Terrestrial Organisms

Exposure in terrestrial habitats would be limited to human skin, clothing, and shoes, as well as
horse skin and hair. Products formulated as lo tions or impregnated wi pes would be applied directly to the human skin. Many other product la bels specify recommended spray distances of
less than 10 inches from the inte nded application sites (human ski n, clothing, and shoes, as well as horse skin and hair). Any m ovement away from the site of application represents potential exposure pathways for a broad range of biological receptors of concern (non-target terrestrial animals and plants) and the potential attribute changes, i.e. , effects such as reduced survival, growth and reproduction, in the receptors due to DEET exposure. The amount of DEET resulting from human or horse application in the terrestr ial environment (air, groun d, plants, or non-treated animals) is inconsequential. As there is no complete exposure pathway under the currently registered uses, EFED presumed risk was discountable to terrest rial organisms.



### 4.3. Uncertainties and Data Gaps

With only one acceptable hydrolysis study submitted to the Agency, there are many data gaps for fate and transport parameters. However, the available open literature and monitoring data suggest DEET does exist in aquatic environments (especially the wastewater streams) with low concentrations. The calculated exposures based on washoff from treated humans and horses into a pond and the monitoring data sugg est that potential aquatic expos ures are several orders of magnitude less than levels of concern.Page 26 of 41 Few ecotoxicity studies have been submitted to th e Agency, and there are many data gaps for the effects data. However, under the currently regist ered use patterns, EFED has concluded (1) low likelihood of risk to aquatic organisms (2) no complete exposure pathway for non-target terrestrial organisms.

Unless the use patterns of DEET change throu gh proposed registrations of new labels, EFED does not consider that filling any of these data gaps is necessary at this time.



## 5. Federally Threatened and Endangered (Listed) Species
Concerns

Section 7 of the Endangered Species Act, 16 U.S.C. Section 1536(a)(2), requires all federal agencies to consult with the National Marine Fisheries Service (NMFS) for marine and anadromous listed species, and/or the United States Fish and Wildlife Service (USFWS) for listed wildlife and freshwater organisms, if they are proposing an "action" that may affect listed species or their designated critical habitat. Each federal agency is required under the Act to ensure that any action they aut horize, fund, or carry out is not likely to jeopardize the continued existence of a listed species or result in the destruction or adverse modification of designated critical habitat. To jeopardize the continued exis tence of a listed species means "to engage in an action that reasonably would be expected, directly or indirec tly, to reduce appreciably the likelihood of both the survival and recovery of a listed species in th e wild by reducing the reproduction, numbers, or distribution of the species" (50 C.F.R. § 402.02).

To facilitate compliance with the requirements of the Endangered Species Act (subsection (a)(2)), the Office of Pesticide Programs has es tablished procedures to evaluate whether a proposed registration action may di rectly or indirectly apprecia bly reduce the likelihood of both the survival and recovery of a listed species in the wild by re ducing the reproduction, numbers, or distribution of any listed sp ecies. After the Agency’s scr eening level risk assessment is conducted, if any of the Agency’s listed species’ LOCs are exceeded fo r either direct or indirect effects, an analysis is conducted to determine if any listed or candidate species may co-occur in the area of the proposed pesticide use or ar eas downstream or downwind that could be
contaminated from drift or runoff/erosion. If lis ted or candidate species may be present in the proposed action area, further biological assessmen t is undertaken. The extent to which listed species may be at risk is considered, which then determines the need for the development of a more comprehensive consultation package, as required by the Enda ngered Species Act.

The federal action addressed herein is the propos ed registration renewal of DEET for human and horse use and it is expected that the use could occur nationwide.Page 27 of 41 

### 5.1. Action Area

For listed species assessment purposes, the action area is considered to be the area affected directly or indirectly by D EET use and not merely the immedi ate area where DEET is applied. At the initial baseline, the risk assessment considers broadly described taxonomic groups and conservatively assumes that listed species with in those broad groups are co-located with the pesticide treatment area. This means that listed terrestrial plants and wildlife are assumed to be located on or adjacent to the treat ed site and listed aquatic orga nisms are assumed to be located in a surface water body adjacent to the treated site. The assessmen t also assumes that the listed species are located within an assumed area, whic h has the relatively highest potential exposure to the pesticide, and that exposures are likely to decrease with dist ance from the treatment area.
Sections 2.3.2 and 3.1 of this risk assessment present the proposed pesticide use sites that are used to establish initial co-location of species w ith treatment areas. An action area is defined as the spatial extent where effects may occur; therefore, no actio n area is defined for this risk
assessment because no LOCs were exceeded. As there is no defined acti on area, a “no effect” determination is made for all listed species.



### 5.2. Taxonomic Groups Potentially at Risk

If RQs are below the listed species LOCs, a "no effect" determination c onclusion is made with respect to listed species in that taxon, and no furt her refinement of the ac tion area is necessary. Furthermore, RQs below the listed species LO Cs for a given taxonomic group indicate no concern for indirect effects on listed species that depend upon the taxonomic group for which the RQ was calculated. However, in situations wh ere the screening assumptions lead to RQs in excess of the listed sp ecies LOCs for a given taxonomic gr oup, a potential for a "may affect" conclusion exists and may be associated with di rect effects on listed sp ecies belonging to that taxonomic group or may extend to indirect e ffects upon listed species that depend upon that taxonomic group as a resource. In such cases, additional information on the biology of listed species, the locations of these species, and the lo cations of use sites are considered to determine the extent to which screening a ssumptions regarding an action area apply to a particular listed organism. These subsequent refinement steps w ill consider how this information would impact the action area for a particular listed organism an d potentially include areas of exposure that are
downwind and downstream of the pesticide use site.

Assessment endpoints, exposure pathways, and th e conceptual models addressing existing DEET uses, and the associated exposur e and effects analyses conducte d for the DEET baseline risk
assessment are in Sections 2 to 3 . The assessment endpoints used in the baseline risk assessment include those defined opera tionally as reduced survival for aquatic animal species from direct acute exposures. These assessmen t endpoints are intended to addre ss the standard se t forth in the Endangered Species Act requiring federal agencies to ensure that any action they authorize does not appreciably reduce the likelihoo d of both the survival and recove ry of a listed species in the wild by reducing the reproduction, numbers, or dist ribution of the species. Risk estimates (RQs) which, integrating exposure and e ffects, are calculated for broa d based taxonomic groups in the screening-level risk assessment presented in Section 4.Page 28 of 41 Both acute endangered species and chronic risk LOCs are considered in the baseline risk assessment to identify direct and indi rect effects to taxa of listed species. This section identifies direct effect concerns, by taxa that are triggered by exceeding endangered LOCs in the baseline risk assessment, with an evalua tion of the potential of individual effects for exposures that may occur at the established endangered species LOC. Data on exposure and effects collected under field and laboratory conditions are evaluated to make determinations on the predictive utility of the direct effect screening assessm ent findings to listed species.

For the uses of DEET, risk from acute exposure is not expected for any non-target animals or plants ( Table 5.1 ). Additionally, the Agency has determined that there will be no habitat modification of any designated critic al habitat for listed species fr om the current registered uses of DEET. Inference regarding aquatic organisms and plants are based on the risk conclusions that registered uses of DEET will not result in LOC exceedances for acute risk to fish and invertebrates. RQs were not calculated for aquatic plants as toxicity data were not available. EFED presumed direct risks were lower than con cern levels to aquatic plants given the mode of action of DEET, the large margin of safety observe d for other aquatic organisms, and the lack of any reported incidents. Similarly, no chronic data were available to allow for chronic RQ calculations. However, given the large margin of safety observed for acute effects based on the most conservative exposure scenario, chroni c RQs are unlikely to exceed concern levels. Conclusions regarding terrestrial organisms and plants are based on the lack of a complete exposure pathway. Exposure in te rrestrial habitats would be lim ited to human skin, clothing, and shoes, as well as horse skin and hair. Products formulated as lotions or impregnated wipes would be applied directly to the human skin. Many other product labels specify recommended spray
distances of less than 10 inches from the inte nded application sites (h uman skin, clothing, and shoes, as well as horse skin and hair). Exposure to listed species is not expected because they would not likely come in close contact with humans or domestic horses ( i.e., the registered use sites).

Table 5.1. Potential Effects to Federally List ed Taxa Associated with Direct or Indirect Effects from the Currently Registered Uses of DEET.

Listed Taxon Direct Effects Indirect Effects

Terrestrial and semi-aquatic plants - monocots No No

Terrestrial and semi-aquatic plants - dicots No No

Birds No No Terrestrial-phase amphibians and reptiles No No

Mammals No No

Terrestrial invertebrates No No Aquatic nonvascular plants No No

Aquatic vascular plants No No

Freshwater fish No No Aquatic-phase amphibians No No

Freshwater invertebrates No No

Marine/estuarine fish No No

Marine/estuarine invertebrates No NoPage 29 of 41 

## 6. References

Aronson D., J Weeks, B Meylan, P Guiney, a nd P H Howard. 2011. Environmental Release, Environmental Concentrations, and Ecologica l Risk of N,N-Diethyl-m-Toluamide (DEET). Integrated Environmental Assessment and Ma nagement. Volume 8, Number 1: p135-166.

Boeckh J, et al. (1996) Acylated 1,3-aminopropanols as repellents against bloodsucking arthropods. Pestic Sci 48:359–373.

Bohbot JD, Dickens JC (2010) Insect Repellen ts: Modulators of Mosquito Odorant Receptor Activity. PLoS ONE 5(8): e12138. doi:10.1371/journal.pone.0012138

Davis, E. E.; Sokolove, P. G. Lactic Acid-sen sitive Receptors on the Antennae of the Mosquito, Aedes aegypti

. J. Comp. Physiol. 1976, 105, 43-54.

Hoffmann EJ, Miller JR (2003) Reassessment of th e role and utility of wind in suppression of mosquito (Diptera: Culicidae) host finding: Stim ulus dilution supported over flight limitation. J
Med Entomol 40:607–614

Holsten JR, Neely NE. 1993. Method for dyeing ar omatic polyamide fibrous materials: N,Ndiethyl(meta-toluamide) dye carrier. Washi ngton (DC): US Patent Office. Patent 5207803. [accessed 2012 May 29]. Available from: http://www.freepatentsonline.com/5207803.html

Jeong, E.Y., J.H. Lim, H.G. Kim, and H.S. Lee. 2008. Acaricidal Activity of Thymus vulgaris Oil and Its Main Components Against Tyrophagus putrescentiae , a Stored Food Mite. J. Food Prot.71(2): 351-355 ECOTOX Ref. No. 102656

KemI. 2010. Assessment report, N,N-diethyl-m eta-toluamide (DEET), Product-type 19 (repellents and attractants). Sundbyberg (SE): KemI, Swedish Chemicals Agency, Rapporteur Member State. 11 March 2010. [cited 2011 May 25]. Available from: http://www.kemi.se/default____550.aspx

McIver, S. B. A model for the mechanism of action of the repellent DEET on the Aedes Aegypti (Diptera: Culicidae). J. Med. Entomol. 1981, 18 (5), 357-361.

Snow, W. F. The effect of a reduction in expi red carbon dioxide on the attractiveness of human subjects to mosquitoes. Bull. Ent. Res. 1970, 60, 43-48.

Syed Z, Leal WS. 2008. Mosquitoes smell and avoid the insect repellent DEET. Proc Natl Acad

Sci USA 105:13598–13603.

USEPA, 1980. Pesticide Registration Standard - DEET. Registration Division and Special Pesticide Review Division, U.S. Environmental Protection Agency. Washington, D.C. NTIS No.

PB81-207722.

USEPA. 1998a. Guidelines for Ecological Risk Assessment . United States EnvironmentalPage 30 of 41 Protection Agency (USEPA). Risk Assessment Fo rum. Office of Research and Development. Available at http://cfpub.epa.gov/ncea/cfm /recordisplay.cfm?deid=12460 (Accessed June 19, 2009).

USEPA. 1998b. EPA Reregistration Eligibility D ecision (RED). United States Environmental Protection Agency, Washington DC 20460. http://www.epa.gov/oppsrrdlIREDs/0002red.pdf

USEPA 2012. Standard Operating Procedures for Resi dential Pesticide Exposure Assessment. U.S. Environmental Protection Agency, Office of Pollution Prevention and Toxics, Office of Pesticide Programs, Health Effects Division. Washington DC. http://www.epa.gov/pesticides/sci ence/residential-exposure-sop.html

USFWS/NMFS/NOAA.2004. 50 CFR Part 402. Join t Counterpart Endangered Species Act Section 7 Consultation Regulations; Final Rule. Federal Register Volume 69. Number 20. Pages 47731-47762. August 5, 2004.

Weeks J, Guiney P, Nikiforov A. 2012. Assessment of the environmental fa te and ecotoxicity of N,N-diethyl-m-toluamide (DEET). In tegr Environ Assess Manag 8:118–132.Page 31 of 41 

## Appendix A: Environmental Fate and Ecotoxicity Data Requirement TablesPage 32 of 41 Table A-1. Available environmental fate data for DEET and remaining data gaps.

158 Guideline

(OPPTS) Description MRID Classification Data Gap? Comments

835.1230 (163-1) Leaching No data No*

835.1240 (163-1) Adsorption/desorption No data No*

835.1410

(163-2) Laboratory volatility No data No*

835.2120

(161-1) Hydrolysis MRID 40192701 No

835.2240

(161-2) Photodegradation in wa ter No data No*

835.2370 (161-4) Photodegradation in air No data No*

835.2410 (161-3) Photodegradation on soil No data No*

835.4100

(162-1) Aerobic soil metabolism No data No*

835.4200 (162-2) Anaerobic soil metabolism No data No*

835.4300

(162-4) Aerobic aquatic metabolism No data No*

835.4400

(162-3) Anaerobic aquatic

metabolism No data No*

835.6100

(164-1) Terrestrial field dissipation No data No*

835.6200 (164-2) Aquatic field dissipation No data No*

835-6300 (164-3) Forestry field dissipation No data No*

850.1730 (165-4) Fish bioconcentration factor No data No*

NGS Drinking water treatm ent No data No*

* Not identified as a data gap under currently registered uses . Proposal of new uses may change the data requirements.Page 33 of 41 Table A-2. Available ecological e ffects data for terrestrial animals expo sed to technical DEET and remaining data gaps.

158
Guideline (OPPTS) Description MRID/
Accession Classification Data Gap? Comments

850.2100

(71-1) Avian oral toxicity MRID 41159701 Acceptable No

. 850.2200

(71-2) Avian dietary toxicity No data No*

850.2300

(71-4) Avian reproduction No data No*

850.3020

(141-1) Honeybee acute contact toxicity No data No*

850.3040

(141-5) Field testing for pollinators No data No*

* Not identified as a data gap under currently registered uses . Proposal of new uses may change the data requirements.

Table A-3. Available ecological effects data for aquatic animals ex posed to technica l DEET and remaining data gaps.

Guideline Description MRID/
Accession Classification Data Gap? Comments

850.1075

(72-1) Freshwater fish – acute toxicity Acc.

00001026 Acceptable No

850.1075

(72-3) Saltwater fish – acute toxicity No data No*

850.1010

(72-2) Freshwater invertebrates – acute toxicity Acc.
00243419 Acceptable No

850.1025

s850.1035

(72-3) Saltwater invertebrates – acute toxicity No data

No*

850.1300

(72-4) Freshwater invertebrate – life cycle test No data No*

850.1350

(72-4) Saltwater invertebrates – life cycle test No data No*

850.1400

(72-4) Freshwater fish – early life stage test No data

No*

850.1400

(72-4) Saltwater fish – early life stage test No data No*

850.1500

(72-5) Fish – life cycle test No data No*

* Not identified as a data gap under currently registered uses . Proposal of new uses may change the data requirements.Page 34 of 41 Table A-4. Available ecological effects data for plants exposed to DEET and remaining data gaps.

Guideline Description MRID Classification Data Gap? Comments

850.4100

(122-1) Terrestrial plant toxicity: tier 1 seedling emergence No data No*

850.4225

(123-1) Terrestrial plant toxicity: tier 2 seedling emergence No data No*

850.4150

(122-1) Terrestrial plant toxicity: tier I vegetative vigor No data No*

850.4150

(123-1) Terrestrial plant toxicity: tier 2 vegetative vigor No data No*

850.4400

(123-2) Aquatic plant growth: al gae No data No*

850.4400

(123-2) Aquatic plant growth: vascular plants No data No*

* Not identified as a data gap under currently registered uses . Proposal of new uses may change the data requirements.Page 35 of 41 

## Appendix B: Publically Available Data Table from EPA’s
ECOTOX DatabasePage 36 of 41Table B-1. Aquatic Ecotoxicity references provided in the publically available ECOTOX database.CASNumberSpeciesScientificNameSpeciesCommonNameEndpointConc 1MeanOp(ug/L)Conc 1Mean(ug/L)Conc1Units(ug/L)ReferenceNumberAuthorTitleSourcePublicationYear134623Daphniamagna Water Flea EC50 75000 ug/L 344Office ofPesticideProgramsPesticideEcotoxicityDatabase(Formerly:EnvironmentalEffects Database(EEDB))Environmental Fateand Effects Division,U.S.EPA,Washington, D.C.: 2000134623Gammarusfasciatus Scud LC50 > 100000 ug/L 6797Mayer,F.L.,Jr.,and M.R.EllersieckManual of AcuteToxicity:Interpretationand Data Basefor 410Chemicals and66 Species ofFreshwaterAnimalsResour.Publ.No.160,U.S.Dep.Interior,Fish Wildl.Serv.,Washington, DC:505p. 1986134623Gammarusfasciatus Scud LC50 > 100000 ug/L 6797Mayer,F.L.,Jr.,and M.R.EllersieckManual of AcuteToxicity:Interpretationand Data Basefor 410Chemicals and66 Species ofFreshwaterAnimalsResour.Publ.No.160,U.S.Dep.Interior,Fish Wildl.Serv.,Washington, DC:505p. 1986134623GambusiaaffinisWesternMosquitofish LC50 235000 ug/L 944Michael,A.G.,and G.S. GrantToxicity of theRepellent DEET(N,N-DiethylMetatoluamide)to Gambusiaaffinis (Bairdand Girard)Mosq. News34(1):32-35 1974134623GambusiaaffinisWesternMosquitofish LC50 235000 ug/L 944Michael,A.G.,and G.S. GrantToxicity of theRepellent DEET(N,N-DiethylMetatoluamide)to Gambusiaaffinis (Bairdand Girard)Mosq. News34(1):32-35 1974Page 37 of 41CASNumberSpeciesScientificNameSpeciesCommonNameEndpointConc 1MeanOp(ug/L)Conc 1Mean(ug/L)Conc1Units(ug/L)ReferenceNumberAuthorTitleSourcePublicationYear134623OncorhynchusmykissRainbowTrout LC50 71250 ug/L 344Office ofPesticideProgramsPesticideEcotoxicityDatabase(Formerly:EnvironmentalEffects Database(EEDB))Environmental Fateand Effects Division,U.S.EPA,Washington, D.C.: 2000134623PimephalespromelasFatheadMinnow LC50 110000 ug/L 12448Brooke,L.T.,D.J. Call, D.L.Geiger, andC.E. NorthcottAcute Toxicitiesof OrganicChemicals toFatheadMinnows(Pimephalespromelas), Vol.1Center for LakeSuperiorEnvironmentalStudies, University ofWisconsin-Superior,Superior, WI:414 p. 1984134623OreochromismossambicusMozambiqueTilapia NR 120000 ug/L 3073Mathai,A.T.,K.S. Pillai, andP.B. DeshmukhAcute Toxicityof Deet to aFreshwater Fish,Tilapiamossambica:Effect on TissueGlutathioneLevelsJ. Environ.Biol.10(2): 87-91 1989134623OreochromismossambicusMozambiqueTilapia NR NR ug/L 3073Mathai,A.T.,K.S. Pillai, andP.B. DeshmukhAcute Toxicityof Deet to aFreshwater Fish,Tilapiamossambica:Effect on TissueGlutathioneLevelsJ. Environ.Biol.10(2): 87-91 1989Page 38 of 41Table B-2. Terrestrial Ecotoxicityreferences provided in the publically available ECOTOX database.CASNumberSpeciesGroupSpeciesScientificNameSpeciesCommonName EndpointObservedResponseMeanObservedResponseUnits EffectReferenceNumber Source Author TitlePublicationYear134623 BirdsColinusvirginianusNorthernBobwhiteQuail LD50 1375mg/kgorg MOR 344EnvironmentalFate andEffectsDivision,U.S.EPA,Washington,D.C.:Office ofPesticideProgramsPesticideEcotoxicityDatabase(Formerly:EnvironmentalEffectsDatabase(EEDB)) 2000134623 Insects/SpidersTyrophagusputrescentiaeCopraMite LD50 13.9 ug/cm2 MOR 102656J. FoodProt.71(2):351-355Jeong,E.Y.,J.H. Lim,H.G. Kim,and H.S.LeeAcaricidalActivity ofThymusvulgaris Oiland Its MainComponentsAgainstTyrophagusputrescentiae,a Stored FoodMite 2008Page 39 of 41 

## Appendix C: Ecological Incident ReportsPage 40 of 41Page 41 of 41