2 UNITED STATES ENVIRONMEN TAL PROTECTION AGENCY WASHINGTON, D.C. 20460

OFFICE OF PREVENTION, PESTICIDES, AND TOXIC SUBSTANCES



# Problem Formulation For Propoxur Environmental Fate And Ecological Risk Assessment

2 – (1 – Methylethoxy) phenol methylcarbamate

Prepared by: Ron Parker, Ph.D. Joseph DeCant, M.S.

Reviewed by: Allen Vaughan, Senior Biologist Mah Shamim, Ph.D., Branch Chief Environmental Risk Branch V 

### United States Environmental Protection Agency Office of Pesticide Programs Environmental Fate an d Effects Division Environmental Risk Branch V 401 M Street, SW Mail Code 7507C Washington, D.C. 2046 

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CH3 CH CH3-3 of 38- Table of Contents

1. Purpose.................................................................................................................... ................... 4 2. Problem Fo rmulation ........................................................................................................ ......... 4 2.1. Nature of Regulatory Action............................................................................................... . 4 2.2. Previous Risk Assessments................................................................................................. . 4 3. Stressor Source and Distribution ........................................................................................... .... 6 3.1. Mechanism of Action....................................................................................................... .... 6 3.2. Overview of Pesticide Usage............................................................................................... 6 3.3. Environmental Fate and Transport....................................................................................... 8 3.3.1. Solubility.............................................................................................................. ......... 9 3.3.2. Mobility................................................................................................................ ......... 9 3.3.3. Degradation............................................................................................................. .... 10 4. Receptors.................................................................................................................. ................ 11 4.1. Effects to Aquatic Organisms ............................................................................................ 12 4.2. Effects to Terrestrial Organisms ........................................................................................ 13 4.3. Incident Database Review.................................................................................................. 16 4.4. Ecosystems Potentially at Risk .......................................................................................... 17 5. Assessment Endpoints ....................................................................................................... ...... 18 6. Conceptual Model........................................................................................................... ......... 18 6.1. Risk Hypothesis ........................................................................................................... ...... 18 6.2. Conceptual Diagram ........................................................................................................ .. 19 7. Analysis Plan .............................................................................................................. ............. 19 7.1. Stressors of Concern ...................................................................................................... .... 20 7.2. Measures of Exposure...................................................................................................... .. 20 7.3. Measures of Effect ........................................................................................................ ..... 21 7.4. Integration of Exposure and Effects .................................................................................. 24 7.5. Deterministic and Probabilistic Assessment Methods....................................................... 24 7.6. Endangered Species Assessments...................................................................................... 24 7.8. Preliminary Identification of Data Gaps............................................................................ 25 7.8.1. Effects ................................................................................................................. ........ 25 7.8.2 Exposure 8. References.................................................................................................................. ........... 27 8.1. Cited Studies and Documents ............................................................................................ 27 8.2. Submitted Effects Studies................................................................................................. . 30 Appendix A. The Risk Quotient Method and Levels of Concern................................................. 33 Appendix B. Data Call-In Table for Propoxur............................................................................. 35-4 of 38- 1. Purpose

The purpose of this problem formulation is to pr ovide an understanding of what is known about the environmental fate and ecological effects of the registered uses of propoxur. Propoxur is an N-methyl residual carbamate insecticide used to control ticks, fleas, and a variety of insects including crickets, ants, wasps, cockroaches and silverfish in and around industrial, commercial, and residential facilities.

This document will provide a plan for analyzing data relevant to propoxur and for conducting environmental fate, ecological risk, and endangered species assessments for its registered uses. Additionally, this problem formulation is inte nded to identify data gaps, uncertainties, and potential assumptions used to address those uncert ainties relative to characterizing the ecological risk associated with the registered uses of propoxur.

2. Problem Formulation

2.1. Nature of Regulatory Action

Under the Federal Insecticide, Fungicide, and Rodenticide Ac t (FIFRA, 1947), all pesticides distributed or sold in the United States generally must be regist ered by EPA. In determining whether a pesticide can be regist ered in the U.S., EPA evaluates its safety to non-target species based on a wide range of environmental and health effects studie s. In 1996, FIFRA was amended by the Food Quality Protection Act, and EPA was mandated to implement a new program for the periodic review of pesticides, i.e ., registration review (USEPA, 1996a). The registration review program is intended to ensure th at, as the ability to assess risk evolves and as policies and practices change, all registered pesticid es continue to meet th e statutory standard of no unreasonable adverse effects to human health and the environment. Changes in science, public policy, and pesticide use practices will occur over time. Through the new registration review program, the Agency periodically reevalua tes pesticides to make sure that as change occurs, products in the market place can be used safely.

As part of the implementation of the new Regist ration Review program pur suant to Section 3(g) of the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA, 1947), the Agency is beginning its evaluation of propoxur to determin e whether it continues to meet the FIFRA standard for registration. This problem formul ation for the environmental fate, ecological risk, and endangered species assessment ch apter in support of the registration revi ew will be posted in the initial docket opening the public phase of the review process.

2.2. Previous Risk Assessments

There are a number of previous risk assessments related to th e uses of propoxur, however many of them provide only limited information. Th e national level risk assessment in the EFED Science Chapter for the Reregistration Eligibil ity Decision (RED; USEPA, 1996) serves as the-5 of 38- basis for this problem formulation. A cumulative human health risk asse ssment was finalized in 2007 for the N-methyl carbamate class of insec ticides which includes propoxur (USEPA, 2007). All other previous risk assessments date to 1991 and earlier, and provide limited information. The risk assessments from 1991 and before are listed below.

• Section 3 New Use (S3NU) label review fo r the outdoor use of Boat Guard (USEPA 1991)

• Section 3 New Use label review for the outdoor use of Baygon (USEPA 1990)

• Ecological effects chapter of the propoxur registrati on standard (USEPA 1987)

• Section 18 Emergency Exemption for the us e of Baygon 70 WP to control mosquitoes (USEPA 1983)

• S3NU for the use of Grant’s Ant Trap and Grant’s Ant Control (USEPA 1978a)

• S3NU for the use of Grant’s Ant Control – Jel (USEPA 1978b)

• S3NU for the use of Chaucon ar ound residences (USEPA 1977a)

• S3NU for the use of Baygon 1.5 Emulsifiab le, Baygon Spray Concentrate, and Baygon 70WP for the control of houseflies and stable flies in livestock and animal barns (USEPA 1977b)

• S3NU for the use of Baygon 70WP an dBaygon MOS for the control of adult mosquitoes and the amendment of registration to the us e of Baygon 70WP for adult mosquito control on alfalfa and grass (USEPA 1977c)

• S3NU for the registration of SMCP Baygon 2% (USEPA 1977d)

• S3NU for the amendment to registration of Baygon 2% in Barns (USEPA 1977e)

• S3NU for the registration of Best Ea rwig and Sowbog Bait (USEPA 1977f)

• S3NU for the registration of Antrol Ant Trap with Baygon (USEPA 1977g)

• S3NU for the registration of Baygon 70% on alfalfa and pasture grass (USEPA 1977h)

• S3NU for the registration of Chacon Ant, Spider and Roach Dust (USEPA 1977i)

• S3NU for the registration of SMCP Ba ygon 2% Mole Cricket Bait (USEPA 1976)

• S3NU for the registration of Baygon MOS Insecticide (USEPA 1975)

The ecological risk assessment included in th e propoxur RED was based on laboratory fate and ecotoxicological data submitted by the registrant in support of reregistration, data in publicly available literature, and incident reports of adverse effect s on non-target organisms associated with the use of propoxur. The pr evious ecological risk assessm ents considered the parent chemical only. The primary environmental concer ns identified in the 1996 RED were acute risks to birds and mammals. EFED did not have the tools with which to assess chronic risk to birds or mammals based on the granular bait application. Therefore, chronic risk to either birds or mammals was not assessed.

Based on the results of the RED, a number of mitigation measures were suggested for consideration to address risks from the 2% bait application of propoxur. On ly the first of these mitigation options appear on the various labels of propoxur products (see Table 2). The options included:-6 of 38- • Add an additional avian labe l precaution, e.g. “Birds and small mammals feeding on treated bait may be killed”

• Label products for restricted-use classification

• Limit the outdoor use to crack and crevice treatment (especia lly since the registrant has previously indicated in the Phase 3 Response that this is the way the product is applied outdoors)

• Reduce the width of the band from the maxi mum allowable three feet, to a narrower band, i.e. 6 inches

3. Stressor Source and Distribution

3.1. Mechanism of Action

Propoxur is an N-methyl carbamate non-systemic inse cticide that is used to control a variety of pests including fleas, ticks, cockroaches, ants, wasps, crickets, silverfish, and other pest insects. Propoxur interferes with acetylcholinesterase, an e ssential enzyme in the transmission of signals in nerve cells. Exposure to pr opoxur results in the overexcitation of the nervous system and eventually death in fleas, ticks and other insects. There are no longer any agri culatural uses registered for propoxur, and most current uses are for indoor applications.

3.2. Overview of Pesticide Usage

Propoxur was originally introduced in the Unite d States in 1959. It has 42 active Section 3 registrations, 2 technical registrations and 3 intermediate formulations ( Table 1 ). There are currently no new uses pending, no special lo cal need registrations, and no emergency exemptions. During the propoxur product reregistration, 7 products were amended and 35 products were reregistered. It is a residual carbamate inse cticide registered for indoor institutional, industrial, and commercial applic ations with very limited outdoor applications. There are permitted uses in food handling establishments and food processing plants such as crack and crevice treatments only. The only outdoor uses include structural perimeter applications as well as liquid and aerosol spot treatments. There are no permitted agricultural uses for propoxur.

Bait stations, aerosol sprays, and liquid spot application uses will not be assessed for environmental risk because they are not expect ed to lead to significant exposure in the environment. The remaining use pattern from cu rrently registered labels , bait application, will be assessed since product labels have granular application di rections that may lead to environmental exposure. Further details of this use pattern are listed in Table 2 . The maximum single granular application ra te for propoxur is 0.005 pounds of ac tive ingredient per thousand square feet (lbs a.i./1K sq. ft) (EPA Reg. N o. 499-518 and 655-802). The labels do not specify how many applications may be applied per year.-7 of 38- Table 1. Currently labeled outdoor uses of propoxur. EPA Reg. No. Product Name Percent Active Ingredient Type of Use

422-18 BA-KIL 19.6 Spot treatment; general surface spray 506-137 TAT Ant Trap 0.25 Bait application 1663-32 Grants Kills Ants Ant Control with Baygon 0.25 Bait application

8730-49 Hercon Insectape High-Tech with Propoxur 10 Surface treatment

10807-48 Misty Wasp and Hornet Killer 0.5 Cr ack and crevice treatment; general surface
spray 45385-13 Chem-Tox Industrial Insect Spray Contains Baygon 1 General surface spray

47000-102 CT Crack and Crevi ce 0.5 General surface spray 10807-4 Misty Anti-Crawl Residual Insecticide 0.5 General surface spray

45385-1 Chem-tox Roach and Ant Spray with Baygon 0.5 Surface treatment; crack and crevice
treatment 499-501 Brand 224B Residual Insecticide 1 Crack and crevice treatment; spot treatment

6218-24 Summit Permacide Plus 1 General surface spray 10807-85 Misty Ant, Roach, and Spider Residual Insecticide 1 General surface spray

84396-12 Sungro Residual Spray 1 General surface spray; perimeter treatment 655-546 Prentox Prenbay 1% Oil Solution 1 General surface spray

655-796 Prentox Prenbay 1.5 EC 19.6 General surface spray; spot treatment 1021-1730 Pyrocide Pressurized Ant and Roach Spray 70451 0.5 Perimeter treatment

13283-26 Rainbow Insect Tag 9.4 Equipment treatment 499-518 Prentox Larva-Lur contains Propoxur 2 Bait application; crack and crevice treatment

84396-18 Sungro Residual Spray 0.5 General surface spray; spot treatment 655-802 Prentox Larva-Lur contains Propoxur 2 Bait application; crack and crevice treatment

Usage data provided to the Biolog ical and Economic Analysis Divi sion (BEAD) of the Office of Pesticide Programs for propoxur indicat es that it is a minor use chem ical in the professional pest management sector, accounting for <1% of the total chemicals applied each year (8,000 and 9,000 lbs applied in 2001 and 2003, respectively). The lack of other usage data precludes an accurate assessment of the extent of total propoxur use.-8 of 38- Table 2. Labeled maximum use patterns for granular applications. Use Pattern EPA Reg. No. App. Rate (lbs a.i./ 1K ft 2 ) No. App. per Year App. Method Restrictions

Bait application 499-518 0.005 Not Specified Granular broadcast in a 2-3 ft width band - Label language: This product is toxic to fish, birds and wildlife. Birds and other wildlife in treated in treated areas may be killed. Do not apply directly to water, to areas where surface water is present or to intertidal areas below the mean high water mark. Do not apply where runoff is likely to occur. Do not contamin ate water by cleaning of equipment or disposal of equipment washwaters. Apply this product only as specified on this label. - For outdoor use around patios, driveways, sidewalks, and foundations only Bait application 655-802 0.005 Not Specified Granular broadcast in a 2-3 ft width band -Label language: This product is toxic to wildlife and aquatic invertebrates. Birds and other small mammals feeding on treated bait may be killed. Do not apply directly to water. Do not apply where runoff is likely to occur. Do not contamin ate water by cleaning of equipment or disposal of wastes. Apply this product only as specified on this label. -Use only around patios, driveways, sidewalks, and foundations.

3.3. Environmental Fate and Transport

For the currently registered uses of propoxur, the Agency typically requires an abbreviated set of environmental fate data on hydrolysis, metabolis m, and mobility. Only supplemental data are available for propoxur. While shortcomings in th e studies preclude a comprehensive assessment of the environmental fate of propoxur , a general assessment can be made.

Based on supplemental data, propoxur is likely to be moderately pe rsistent (the metabolic halflife is on the order of several months), mobile, and may potentially leach to groundwater. It is apparently hydrolytica lly stable at acid to neutral pHs (3 to 7) but degrades ra pidly at alkaline pH values. The parent chemical appears susceptible to photolysis in water bu t not on soil. However, the intensity of light in the studies did not refl ect that of natural sun light. Aerobic and anaerobic soil metabolism half-lives are on the order of several months. Degradate characterization was incomplete in these studies. Laboratory mobility studies indicate that propoxur is very mobile (K d values less than 1). Propoxur exhi bits fate and transport charac teristics similar to chemicals that are known to leach to groundwater.

Well-designed, scientifically-val id studies could resu lt in changes in the overall assessment, particularly in relation to persis tence. For instance, photolysis may play a role in degradation of propoxur applied outdoors. However, considering the nature of the listed outdoor uses, additional-9 of 38- studies are not required at this time. The limited da ta available only support the uses discussed in this document. Any additional uses will require data to support them.

3.3.1. Solubility

CAS #: 114-26-1 H20 solubility: 2,000 mg/l at 20-25 degrees C (U.S . Environmental Protection Agency. 1984); 1,750 ppm at 20 degrees C (Berg, G. L., 1986) Solubility in other solvents: soluble in organic polar solven ts, readily soluble in acetone (American Conference of Govern mental Industrial Hygienists, Inc. 1986); soluble in methanol, acetone, and many other organic solvents but only slight ly soluble in co ld hydrocarbons (Hayes, W. J. 1982). Melting Point: 81 degrees C (Berg, G. L., 1986) Vapor pressure: 6.5 x 10 to the minus 6 mmHg at 20 degrees C (Hayes, W. J. 1982); 1 x 10 to the minus 6 mmHg at 120 degrees C (Worthing, C. R., 1983)
Bioconcentration factor: 9 (calculated from water solubi lity by regression equations) (TOXNET. 1986)
Kow: log Kow = 1.45 (U.S. Environmental Protection Agency. 1986)
Koc: 67 (calculated from water solubi lity by regression equations) (TOXNET. 1986) Partitioning Model: PCMC1 (mole fraction) 1.72 x 10 to the minus 4; PCMC2 (mg/l) 2,000; PCMC3 (mcm/l) 9,600 (U.S. Environmental Protection Agency. 1984) Chemical Class/Use: methyl carbamate insecticide

3.3.2. Mobility

Leaching & adsorption/desorption (163-1)

In soil thin-layer mobility studies on six soils, propoxur was found to be mobile, with R values of 0.70 to 0.89 (MRID 0029887).

In batch equilibrium studies, propoxur was very mobile, with Freundlich K values of 0.05 (sandy loam), 0.30 (silt loam), and 0.27 (silty clay). K oc values, calculated from the K d and organic carbon (from organic d matter) data supplied in the report , were 3.4 (sandy loam), 11.2 (silt loam), and 102.6 (silty clay) (MRID 0085770).

After 28 days of aerobic incubatio n in a silt loam soil, propoxur was found to be mobile in 12- inch soil columns. The leachate contained 69 to 74% of the applied radioactivity after 100 ml of water was applied over a 45 day period (MRID 0085769).-10 of 38- (3) Field Dissipation

Terrestrial field dissipation (164-1)

Rough data from 10 studies on the persistence of propoxur in several different soil types suggest that the chemical moves rapidly through all th e soil profiles below the 12 inch sampling depth (MRID 0085772).

Environmental fate data on aqueous and soil photo lysis, aerobic and anaerobic soil metabolism, leaching and adsorption/desorption, and terrestrial field dissipation are not required to support the current uses for propoxur. New studies may be required if other outdoor uses are considered in the future.

3.3.3. Degradation

Hydrolysis (161-1)

An open literature study of several carbamates found that propoxur was stab le to hydrolysis at pH 3.0-7.0 but degraded at alkaline pH values. The half-life for hydrol ysis was 16 days at pH 8, 1.6 days at Ph 9, and 0.17 days at pH10 (MRID 0085762).

Photodegradation in water (161-2)

Propoxur degraded in neutral, aqueous solutions (5 ppm propoxur) with a half-life of 10 days without a photosensitizer and 0.7 days with an acetone sensitizer. The degr adation half-life was 41 days in the dark control. Compensating for hydr olysis effects, the unsensitized halflife was projected at 13 days. The major degradat es were isopropoxy phenol, unidentified polar compounds, and CO. The artificial light source had an intensity less than that of natural sunlight in Kansas City, MO (800 u-watts/cm 2 vs. 3300-4400 u-watts/cm 2 at midday in summer (MRID 0085763).

Photodegradation in soil (161-3)

Propoxur photodegraded on a pH 8.2 sandy loam soil with a half-life of 77 days (extrapolated beyond the 28 day study). After 28 days, propoxur co mprised 75% of the applied radioactivity, unextracted residues 12%, and volatiles 10%. The artificial li ght source was the same as that used in the aqueous photolysis study (MRID 0085763).

Aerobic soil metabolism (162-1)

The degradation of Propoxur under aerobic conditions in silt loam and sandy loam soils followed first order kinetics for the first 112 and 180 days, respectively. The half-lif e values were 80 days for the silt loam and 210 days for the sandy loam. Propoxur was the major extractable residue found in the studies. CO (30% after 112 days; 35% after 336 days) and unextracted residues (up-11 of 38- to 40%) also comprised major portions of the applied radioactivity. The primary mode of degradation appears to be hydrolysis of the carbamate linkage (MRID 0085768).

Anaerobic soil metabolism (162-2)

Propoxur degraded in a silt loam soil under anaerobic conditions with a half life of 80 days, the same as found in the aerobic metabolism study a bove. The anaerobic half-life resulting from the flooding of a sandy loam that had been incubate d aerobically for 30 days was 108 days. The halflife in sterile soils was the same as that measured in non-sterile soils (MRID 0085768).

4. Receptors

Consistent with the process described in th e Overview Document (USEPA, 2004), the risk assessment for propoxur relies on a surrogate species approach. Toxicological data generated from surrogate test species, whic h are intended to be representa tive of broad taxonomic groups, are used to extrapolate to pot ential effects on a vari ety of species (rec eptors) included under these taxonomic groupings.

Acute toxicity data from studies submitted by pe sticide registrants along with the available open literature are used to evaluate th e potential direct and indirect effects of propoxur to terrestrial receptors. Submitted data typically include toxi city information on the technical grade active ingredient, degradates, and when av ailable, formulated products ( e.g. , “Six-Pack” studies). The open literature studies are identified th rough EPA’s ECOTOXicology (ECOTOX) database (USEPA, 2008a), which employs a literature search engine for locating chemical toxicity data for aquatic life, terrestrial plants , and wildlife. The evaluation of both sources of data may also provide insight into the direct and indirect effects of propoxur on biotic communities from loss of species that are sensitive to the chemical and from changes in structure and functional characteristics of the affected communities.

A complete search of the ECOTOX database for propoxur toxicity data was completed in June 2009 and a large number of potentially relevant open literature papers for propoxur were identified. An evaluation of the ECOTOX open lit erature studies for possi ble quantitative and/or qualitative inclusion in the ecological risk asse ssment, including identification of open literature data that may be used to fill the large number of ecological effects data gaps, is expected to be completed prior to the docket opening for pro poxur. Based on a preliminary review of the ECOTOX search, open literatu re data were identified fo r a number of taxonomic groups, including estuarine/marine fish, freshwater fi sh, mammals, invertebrates, and amphibians. Studies, though very limited in number, were al so identified for both terrestrial and aquatic plants, for which no registrant-submitted data ar e available. The extent to which the open literature data can be used to fulfill these data gaps will be determined pending its review and evaluation.

A summary of the aquatic and terrestrial toxicity data used to derive a preliminary evaluation of risk for propoxur is provided in Sections 4.1 and 4.2, respectively. In a ddition, a summary of-12 of 38- ecological incidents associated with propoxur and a desc ription of ecosystems potentially at risk are provided in Sections 4.3 and 4.4, respectively.

4.1. Effects to Aquatic Organisms

A summary of the aquatic toxicity data from registrant-submitted studies is provided in Table 3

. Propoxur was used in the aquatic testing. Propoxur is classified as m oderately toxic to freshwater fish and very highl y toxic to both freshwater and ma rine invertebrates on an acute exposure basis. Toxicity data for aquatic vascul ar and non-vascular plants are not available.

Table 3. Summary of submitted aqua tic toxicity studies for propoxur.

Species (common name) % a.i. Endpoint (ppm) Acute Toxicity Classification Citation

MRID/ Accession number Study Classification

Oncorhynchus mykiss (Rainbow Trout) 98.8 3.7 (acute LC 50 ) Moderately toxic 00149171

D. Lamb 1981 Acceptable

Oncorhynchus mykiss (Rainbow Trout) 88 8.2 (acute LC 50 ) Moderately toxic 40098001 Mayer and Ellersieck 1986 Supplemental

Lepomis macrochirus (Bluegill sunfish) 98.8 6.2 (acute LC 50 ) Moderately toxic 00149171

D. Lamb 1981 Acceptable

Lepomis macrochirus (Bluegill sunfish) 88 4.8 (acute LC 50 ) Moderately toxic 40098001 Mayer and Ellersieck 1986 Supplemental

Daphnia magna

(Water Flea) 98.8 0.011 (acute EC 50 ) Very highly toxic 00149172

D. Lamb 1981 Acceptable-13 of 38- Table 3. Summary of submitted aqua tic toxicity studies for propoxur.

Species (common name) % a.i. Endpoint (ppm) Acute Toxicity Classification Citation

MRID/ Accession number Study Classification

Daphnia magna

(Water Flea) 98.5 >0.051 (21 day LC 50 ) N/A 41425301 D. Surprenant Supplemental

Pimephales promelus (Fathead minnow) 88 25 (acute LC 50 ) Slightly toxic 40098001 Mayer and Ellersieck 1986 Supplemental

Gammarus

lacustris (Amphipod) 88 0.034 (acute LC 50 ) Very highly toxic 40098001 Mayer and Ellersieck 1986 Supplemental

Pteronarcys

(Stonefly) 88 0.18 (acute LC 50 ) Highly toxic 40098001 Mayer and Ellersieck 1986 Supplemental

Oyster 100 >1 (96-hour

EC 50 ) Moderately toxic 40228401 Mayer 1986 Supplemental

Sheepshead

minnow 100 >1 (48-hour

LC 50 ) Moderately toxic 40228401 Mayer 1986 Supplemental

Penaeus duoraum (Pink shrimp) 100 0.041 (48-hour

LC 50 ) Very highly toxic 40228401 Mayer 1986 Supplemental

Scenedesmus subspicatus (Green Algae) Technical ECx - 158414 Not yet reviewed

4.2. Effects to Terrestrial Organisms

Available data on the toxicity of propoxur to terrestrial animals are summarized in Tables 4 and 5 . Data for terrestrial plant toxi city are not available for propoxur.

Propoxur is classified as moderate ly toxic to mammals and very hi ghly toxic to bi rds on an acute oral basis and also highly toxic to birds on a sub-acute dietary exposure basis. In addition, propoxur is highly toxic to honey bees ( Apis mellifera ) on an acute contact exposure basis.-14 of 38- Table 4. Summary of endpoints from submitted terrestrial animal acut e toxicity studies for propoxur. Species (common

name) % a.i. End-point Acute Toxicity Classification Citation

MRID / Accession number Study Classification

Canada goose 87 5.95 (mg/kg bwt) Very highly toxic 00160000
Hudson et al. 1984 Supplemental 1

Mallard 98 9.44 (mg/kg bwt) Very highly toxic “ ” “ ”

Sharp-tailed
grouse 97 120 (mg/kg bwt) Moderately toxic “ ” “ ”

California quail 97 25.9 (mg/kg bwt) Highly toxic “ ” “ ”

Japanese quail 97 28.3 (mg/kg bwt) Highly toxic “ ” “ ”

Pheasant 98 20 (mg/kg bwt) Highly toxic “ ” “ ”

Chukar 98 25.8 (mg/kg bwt) Highly toxic “ ” “ ”

Sandhill crane 98 60.4 (mg/kg bwt) Moderately toxic “ ” “ ”

Rock dove 97 60.4 (mg/kg bwt) Moderately toxic “ ” “ ”

House
sparrow 97 12.8 (mg/kg bwt) Highly toxic “ ” “ ”

Mourning dove 97 4.2 (mg/kg bwt) Very highly toxic “ ” “ ”

House finch 97 3.55 (mg/kg bwt) Very highly toxic “ ” “ ”

Dark-eyed

junco 97 4.76 (mg/kg bwt) Very highly toxic “ ” “ ”

Bobwhite

quail 2 (Formulated product - bait) 23 (mg a.i./kg basis)

1005 (formulated product basis) Highly toxic 41625101 Campbell et al. 1990 Acceptable-15 of 38- Table 4. Summary of endpoints from submitted terrestrial animal acut e toxicity studies for propoxur. Species (common

name) % a.i. End-point Acute Toxicity Classification Citation

MRID / Accession number Study Classification

Northern bobwhite

quail Technical % unknown 2828 (ppm) Slightly toxic 42757101

42301201

00149015

Lamb 1981 Supplemental 2

Mallard duck 98.8 >5000 (ppm) Practically non-toxic 42757102

42301202

00149014

Lamb 1981 “ ”

Northern bobwhite

quail Technical % unknown 206 (ppm) Highly toxic 00022923

Hill et al. 1975 Supplemental 3

Japanese quail Technical % unknown >5000 (ppm) Practically non-toxic “ ” “ ”

Ring-necked

pheasant Technical % unknown Approx. 1750 (ppm) Slightly toxic “ ” “ ”

Mallard Technical % unknown <1000 (ppm) Moderately toxic “ ” “ ”

Rattus norvegicus (Laboratory rat) Technical 94 mg/kg (M) 68 mg/kg (F)

(oral LD 50 ) - 00152443 -

Rabbit Technical > 2000mg/kg (Dermal LD50) - 40836401 -

Rattus norvegicus (Laboratory rat) Technical > 0.498 mg/L (Acute Inhalation LC 50 ) - 40836402 -

Rattus norvegicus (Laboratory rat) 99.8 >80 ppm reproductive effect NOEC (2 generation reproduction) No reproductive toxicity was observed at levels up to 80

ppm in diet 42615403 -

Apis mellifera (Honey Bee) Not reported 1.35 (LD 50 ) Highly toxic 00036935

Atkins et al. 1975 Core 4-16 of 38- Table 4. Summary of endpoints from submitted terrestrial animal acut e toxicity studies for propoxur. Species (common

name) % a.i. End-point Acute Toxicity Classification Citation

MRID / Accession number Study Classification

1 These studies are classified as supplemental. The USDI data are derived from scientifically sound studies that have been used to fulfill the guideline requirements in previous assessments. 2 These studies are classified supple mental and not upgradeable (see memo s A. Maciorowski to N. Kotey dated 1/27/93 and A. Maciorowski to K. Davis dated 9/21/93). The mallard study is supplemental because only two treatment levels were employed and the age of the birds (13 days) was higher than the recommended 5-10 day age; also Miles was not able to adequately respond to a discrepancy between Hill’s mallard LC50 value of <1000ppm and Lamb’s LC50 value of >5000ppm. The bobwhite study continues to be classified supplemental because of study deficiencies listed in the DER and b ecause Miles was unable to adequately explain the large discrepancy between Hill’s LC50 value of <206ppm and Lamb’s LC50 value of 2828ppm. 3 Although the actual % ai was not reported, it is assumed it was greater than 95%. 4 This study has been classified as scientifically sound and has been used to fulfill the guideline requirements in previous assessments. Although the actual % ai was not reported, it is assumed that it was greater than 95%.

Table 5. Summary of endpoints from submitted terrestrial animal chroni c toxicity studies for propoxur.

Species (common

name) % a.i. End-point Acute Toxicity Classification Citation

MRID / Accession number Study Classification

Colinus virginianus (Northern bobwhite

quail) 98 >320 ppm, highest dose tested - 00149017

D. Lamb and M.

Carsel 1982 Supplemental 1

Anas platyrhynchos (Mallard duck) 98 80 ppm/320 ppm Reduced egg production and embryo viability 00149016 J. Carlise and M.

Carlise 1982 Supplemental 2

1 This study is reclassified supplemental because a NOEC for reproductive effects was not established. The NOEC for brain cholinesterase inhibition was 80 ppm. 2 This study is classified supplemental because the raw da ta were not provided to a llow statistical verification of the results.

4.3. Incident Database Review

A preliminary review on August 12, 2009, of the Ecological Incident Information System (EIIS, version 2.1, USEPA, 2008b), which is maintained by the Agency’s Office of Pesticide Programs, and the Avian Monitoring Information System (A IMS), which is maintained by the American-17 of 38- Bird Conservancy, indicates a total of three reported ecological incidents associated with the use of propoxur.

All of the propoxur incidents were classified as highly probabl y and a result of intentional misapplication, and they occurred between 1992 and 2000. All of the propoxur incidents involved birds. All of the in cidents involved additional ch emicals besides propoxur. The reported incidents for propoxur in volved uses in which the product was not specified. While these products do not appear to be currently registered, sim ilar granular bait products are currently registered.

In addition to the incidents recorded in EIIS, additional incidents have been reported to the Agency in aggregated incident re ports. Pesticide registrants repor t certain types of incidents to the Agency as aggregate counts of incident s occurring per product pe r quarter. Ecological incidents reported in aggregate reports include t hose categorized as “minor fish and wildlife” (W-B), “minor plant” (P-B), a nd “other nontarget” (ONT) incident s. “Other nontarget” incidents include reports of adverse effects to insects an d other terrestrial invert ebrates. For propoxur, registrants have reported 13 mi nor plant incidents but no minor fish and wildlife incidents or other nontarget incidents.

In the risk assessment, the incidents will be further evaluated to determine if the reported incidents represent current patter ns of use for propoxur. Examples of additional considerations are mitigation ( e.g ., reduced application rates), product can cellations, and changes in use patterns that have occurred since the da te of the reported incidents.

Although incident reports for pr opoxur have not been received by the Agency since 2000 and only three incidents have been re ported to the Agency, the absen ce of reported incidents should not be construed as the absence of incidents. Incident reports for non-target organisms typically provide information only on mortality events and plant damage incidents. Except for phytotoxic effects in terrestrial plants, s ublethal effects, such as reduced growth or impaired reproduction, are rarely reported. EPA’s changes in the regist rant reporting requireme nts for incidents in 1998 may account for a reduced number of reported inci dents. Registrants are now only required to submit detailed information on ‘major’ fish, wildlif e, and plant incidents. Minor fish, wildlife, and plant incidents, as well as all other nontarget incidents, ar e generally reported aggregately and are not included in EIIS. In addition, there ha ve been changes in state monitoring efforts due to lack of resources. However, the incident data that are available suggest that exposure pathways for propoxur are complete and that expos ure levels are sufficient to result in fieldobservable effects.

4.4. Ecosystems Potentially at Risk

The ecosystems 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 and based on the usag e pattern of propoxur, terrestrial ecosystems are potentially at risk and woul d include the treated area.-18 of 38- Due to the use patterns and relatively low usage of propoxur, EFED does not believe that aquatic exposure to propoxur will pose a risk to non-target organisms. The majority of propoxur uses are indoors, and usage data from the Biological and Economic Analysis Di vision (BEAD) of the Office of Pesticide Programs sugge sts that propoxur is a minor us e chemical. The majority of uses are spot treatments with no agricultural uses . The previous Science Chapter of the RED in 1996 modeled aquatic exposure from the propoxur impr egnated tape that co uld be attached to boat mooring lines. This use, however, has been cancelled and no other uses appear to be a significant route of aquatic expo sure. Therefore, based on the limited outdoor uses and relatively low usage, OPP will not be doing either an aquatic ecological assessment or a human health drinking water assessment for propoxur.

5. Assessment Endpoints

Assessment endpoints represent the ac tual environmental value that is to be protected, defined by an ecological entity (species, community, or othe r entity) and its attrib ute or characteristics (USEPA, 1998). For propoxur, the ecological ent ities may include the following: birds, mammals, terrestrial-phase amphibians, reptiles, terre strial plants, and insects. The attributes for each of these entities may include gr owth, reproduction, and survival.

6. Conceptual Model

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

The conceptual model for propoxur provides a writt en description and visual representation of the predicted relationships betw een propoxur, potential routes of exposure, and the predicted effects for the assessment endpoint. A conceptu al model consists of two major components: a risk hypothesis and a conceptual diagram, which are discussed below (USEPA, 1998).

6.1. Risk Hypothesis

A risk hypothesis describes the predicted re lationship among the stressor, exposure, and assessment endpoint response along with the rationale for thei r selection. For propoxur, the following ecological risk hypothesi s is being employed for this ecological risk assessment:

Based on the application methods and availabl e toxicity data for non-target terrestrial species, propoxur has the potential to redu ce survival, reproduction, and/or growth in non-target birds, mammals, terrestrial pha se amphibians and reptiles, and beneficial subterranean insects when used in accordan ce with the current labels. These non-target-19 of 38- organisms include federally listed threat ened and endangered species as well as nonlisted species.

6.2. Conceptual Diagram

Based on the usage patterns of propoxur, granular bait applications repres ent potential transport mechanisms of propoxur to terrestrial habitats where non-target organisms may be exposed. Other terrestrial uses (e.g. spot spray, aerosol, and bait trap applicatio ns) will not be assessed because they are not expected to be significant routes of exposure and EFED does not currently have exposure scenarios for these types of uses. The tran sport mechanisms ( i.e ., sources) of the 2% granular bait application are depict ed in the conceptual model below ( Figure 2 ) along with the receptors of concern and the potential attribute cha nges in the receptors due to exposures to
propoxur.

Figure 2. Conceptual model for propoxur effects on terrestrial or ganisms. Dashed lines represent uncertainty from a lack of effects data.
7. 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 ecol ogical effects of propoxur 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 Stressor

Sou r ce

Receptors

Attribute Change Propoxur (granular bait) applied to use site (Commercial and Residential Structures)

Direct application

Terrestrial invertebrates Terrestrial/riparian plants grasses/forbs, fruit, seeds (trees, shrubs) Exposure Media Birds / Mammals/Terrestrial phase amphibians/reptiles Soil

Ingestion/Dermal Uptake

Birds / mammals / terrestrial amphibians / reptiles/ subterranean invertebrates Juvenile Adul t Ingestion
Ingestion

Habitat integrity Reduction in primary productivity Reduced cover Community change Food chain Reduction in prey Individual organisms Reduced survival Reduced growth Reduced reproduction-20 of 38- and magnitude of adverse ecological effects, the risk quotient-based approach does not provide a quantitative estimate of likelihood an d/or magnitude of an adverse effect. However, as outlined in the Overview Document (USEPA, 2004), the li kelihood of effects to individual organisms from particular uses of propoxur is estimated us ing the probit dose-response slope and either the level of concern (discussed below) or the actual calculated risk quotient value.

This analysis plan will be revisited and may be revised depending upon the review and evaluation of data available in the open literature and the info rmation submitted by the public in response to the opening of the Registration Review docket.

7.1. Stressors of Concern

The focus of this assessment is the propoxur, and any environmental degradates will be screened for ecological risk concern using the available data.

In its ecological risk assessments, the Agency does not routinely include an evaluation of mixtures of active ingredients, either those mi xtures of multiple active ingredients in product formulations or those in the applicator’s tank. In the case of the product formulations of active ingredients (that is, a registered product containi ng more than one active ingredient), each active ingredient is subject to an i ndividual risk assessment for regul atory decision regarding the active ingredient on a particular use site. If eff ects data are available for a formulated product containing more than one active ingredient, the data may be used qualitatively or quantitatively in accordance with the Agency’s Overview Document and the Services’ Evaluation Memorandum (USEPA, 2004; U SFWS/NMFS, 1998).

Available toxicity data for environmental mixt ures of propoxur with other pesticides will be presented as part of the ecological risk assessment. It is expected that the potential toxic effect of propoxur, in combination with other pe sticides used in the environmen t, is likely to be a function of many factors including but not necessarily limited to: (1) the exposed species, (2) the cocontaminants in the mixture, (3) the ratio of propoxur and co-contaminant concentrations, and (4) differences in the pattern and duration of exposure among c ontaminants. Quantitatively predicting the combined effects of all these variables on mixture t oxicity to any given taxa with confidence is beyond the capabil ities of the available data and methodologies. However, a qualitative discussion of implications of the available pesticide mixture effects data on the confidence of risk assessment conc lusions will be addressed as pa rt of the uncerta inty analysis.

7.2. Measures of Exposure

In order to estimate risks of propoxur exposures in terrestrial enviro nments, all exposure modeling and resulting risk conclusions will be made based on maximum application rates for the 2% granular bait use patterns listed in Table 2 . Measures of exposure are based on terrestrial models that predict estimated environmental concentrations (EEC) of propoxur using maximum labeled application rates and methods, as well as any mitigation measures specifically indicated-21 of 38- on the label. The models used to pred ict terrestrial EECs on food items is the T errestrial R esidue EX posure model (T-REX) for mammals and birds and the T errestrial H erptafaunal E xposure and R esidue P rogram S imulation (T-HERPS). The model used to derive EECs relevant to terrestrial and wetland plants is TerrPlant . These models are parameteri zed using relevant reviewed registrant-submitted environmental fate data.

Exposure estimates for terrestrial an imals assumed to be in the targ et area or in an area exposed to spray drift are derived using the T-RE X model (v1.3.1; Dec. 7, 2006). This model incorporates the Kenega nomogr aph, as modified by Fletcher et al. (1994), which is based on a large set of actual field residue data. The upper limit values fr om the nomograph represent the 95 th percentile of residue values from actual fi eld measurements (Hoerger and Kenega, 1972). The Fletcher et al. (1994) modifications to the Kenega nomograph are based on measured field residues from 249 published research papers, incl uding information on 118 species of plants, 121 pesticides, and 17 chemical classes.

Exposure estimates from granular applications for birds (and, thus, terr estrial-phase amphibians and reptiles), terrestrial subterranean invertebrates, and mammals assumed to be in the target area or in an area exposed to propoxur granules are derived using the T-REX model. T-REX includes the capability to calculate the LD 50 /ft 2 risk index values. Conceptually, an LD 50 /ft 2 is the amount of a pesticide estimated to kill 50% of exposed animals in each squa re foot of applied area. Although a square foot does not have defined ecologica l relevance and any unit area could be used, risk presumably in creases as the number of LD 50 s/ft 2 increases. The LD 50 /ft 2 is used to estimate risk for granular formulations and row, banded, and in-furrow applications. For additional information on the LD 50 /ft 2 risk index, please refere nce U.S. EPA (1992). The LD 50 /ft 2 is calculated using a to xicity value (adjusted LD 50 ) and the EEC (mg a.i. ft -2 ) and is directly compared with the Agency's levels of concern (LOCs).

The weight of each granule is also necessary in formation related to risk characterization in TREX for granular applications. T-REX provides information on the LD 50 /ft 2 based on the application rate of the granular formulation. In some cases, an animal may have to ingest large quantities of the pesticide, wher eas in other cases the animal would only need to ingest a few granules to reach the adjusted LD50. The weight of each granule would therefore further refine the risk assessment by allowing the chemical re viewer to determine how many granules an animal would need to ingest to reach the ad justed LD50 and how probable the ingestion rate would be. This information should be obtained from the registrant in order to faci litate the risk assessment for terrestrial applications.

7.3. Measures of Effect

Ecological effects data are used as measures of direct a nd indirect effects to biological receptors. Data are obtained from registrant-submitted studies or from literature studies identified by ECOTOX. The ECOTOX database (USEPA, 2008a) provides more ec ological effects data in an attempt to bridge existing data gaps. ECOTOX is a source for locating single chemical toxicity data and potential chemical mixture toxicity data for aquatic life, terrestrial plants, and wildlife. ECOTOX was created and is maintained by the US EPA, Office of Research and Development,-22 of 38- and the National Health and Environmental E ffects Research Laboratory's Mid-Continent Ecology Division. A number of studies were identified in the open literature as acceptable according to OPP and EFED criteria through a sear ch of the ECOTOX data base. These studies are listed in Table 6.

Information on the potential effect s of propoxur on non-target animals is collected from the EIIS, which will also be incorporated into the assessm ent. The EIIS is a database containing adverse effect (typically mortality) reports on non-target organisms where such effects have been associated with the use of pesticides. This in formation will be used to assess the presence of toxic exposure to non-target organisms after propoxur application in th e environment and the conditions under which the exposure occurred.

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

The assessment of risk for direct effects to non-target organisms ma kes the assumption that toxicity of propoxur to birds is similar to terrestrial-phase amphi bians and reptiles. The same assumption is made for fish and aquatic-phase amphibians.

Table 6. Summary of endpoints from the open literature for propoxur.

Species (common

name) % a.i. End-point Citation

MRID/ Ecotox Reference Number Study Classification

Oncorhynch

us mykiss (Rainbow

Trout) 2 (Formulated Product - bait) 92 (ppm acute LC 50 ) 44027705

USEPA/McCann 1975 Supplemental

Lepomis macrochirus

(Bluegill sunfish) Technical (% Unknown) 6.1 (ppm acute LC 50 ) 44027704

USEPA/McCann 1977 Supplemental

Lepomis macrochirus

(Bluegill sunfish) 70 (Formulated

Product – wettable powder) 9.0 (ppm acute LC 50 ) 44027703

USEPA/McCann 1977 Supplemental

Lepomis macrochirus

(Bluegill sunfish) 2 (Formulated Product - bait) >180 (ppm acute LC 50 ) 44027702

USEPA/McCann 1975 Supplemental-23 of 38- Table 6. Summary of endpoints from the open literature for propoxur.

Species (common

name) % a.i. End-point Citation

MRID/ Ecotox Reference Number Study Classification

Lepomis macrochirus

(Bluegill sunfish) 70 (Formulated

Product – wettable powder) 3.55 (ppm acute LC 50 ) 44027701

USEPA/McCann 1977 Supplemental

Norway Rat 99.2 32.74 mg/kg (dietary LD 50 ) 110891 Not yet reviewed

House Mouse 98 0.50 mg/kg (dietary chronic NOAEL) 111332 Not yet reviewed

Apis mellifera (Honey Bee) 100 0.112 (acute contact LD 50 ) 67983 Not yet reviewed

Rana catesbeiana (Bullfrog) 97 595 mg/kg bwt (acute dietary LD 50 ) 50386 Not yet reviewed

Earthworm 10 2 lbs a.i./acre (LOEL) 67190 Not yet reviewed

Soybean 100 4 oz a.i./cwt sd 103956 Not yet reviewed

1 These studies are classified as supplemental. The USDI data are derived from scientifically sound studies that have been used to fulfill the guideline requirements in previous assessments. Although the actual % ai was not reported, it is assumed it was greater than 95%.

The acute measures of effect used for animals in this assessment are the LD 50 , LC 50 and EC 50
. LD stands for "Lethal Dose", and LD 50 is the amount of a material, given all at once, that is estimated to cause the death of 50% of the test or ganisms. LC stands for “Lethal Concentration” and LC 50 is the concentration of a chemical that is estimated to kill 50% of the test organisms. EC stands for “Effective Concentration” and the EC 50 is the concentration of a chemical that is estimated to produce a specific effect in 50% of the test organisms. Endpoints for chronic measures of exposure for listed and non-lis ted animals are the NOAEL/NOAEC and NOEC. NOAEL stands for “No Observed-Adverse-Effect-Level ” and refers to the hi ghest tested dose of a substance that has been reporte d to have no harmful (adverse) e ffects on test organisms. The NOAEC ( i.e. , “No-Observed-Adverse-Effect-Concentration” ) is the highest test concentration at which none of the observed effects were statistically different fr om the control. The NOEC is the No-Observed-Effects-Concen tration. For non-listed plants , only acute exposures are-24 of 38- assessed ( i.e. , EC 25 for terrestrial plants and EC 50 for aquatic plants); for listed plants either the NOAEC or EC 05 is used.

7.4. Integration of Exposure and Effects

Risk characterization is the in tegration of exposure and ecologi cal effects characterization to determine the potential ecological risk from the use of propoxur as a bait application and crack and crevice treatment around residential and comme rcial structures. The exposure and toxicity effects data are integrated in order to evaluate the risks ofadverse ecological effects on nontarget species. For the assessment of propoxur risk s, the risk quotient (R Q) method is used to compare exposure and measured toxicity values. EECs are divided by acute and chronic toxicity values. The resulting RQs are then compared to the Agency’s Levels of Concern (LOCs) (USEPA, 2004). These criteria are used to in dicate when propoxur’s uses, as directed on the label, have the potential to cause adverse direct or indirect effects to non- target organisms. In addition, incident data from the E IIS will be considered as part of the risk characterization.

7.5. Deterministic and Probabilistic Assessment Methods

The quantitative assessment of risk will primar ily depend on the deterministic point-estimate based approach described in the risk assessment. An effort will be made to further qualitatively describe risk using probabilistic tools that the Agency has developed. These tools have been reviewed by FIFRA Scientific Advisory Pane ls (http://www.epa.gov/sci poly/sap/index.htm) and have been deemed as appropriate means of refi ning assessments where deterministic approaches have identified risks.

7.6. Endangered Species Assessments

Consistent with the Agency’s responsibility under the Endangered Sp ecies Act (ESA), the Agency will evaluate risks to Federally-listed th reatened and/or endangere d (listed) species from registered uses of propoxur during registration review. This assessment will be conducted in accordance with the Overview Document (USE PA, 2004), provisions of the ESA, and the Services’ Endangered Species C onsultation Handbook (USFWS/NMFS, 1998).

The assessment of effects associ ated with the registra tion of propoxur is base d on an action area. The action area is considered to be the area directly or indirectly affected by the federal action, as indicated by the exceedance of Agency Levels of Concern (LOCs) used to evaluate direct or indirect effects. The Agency’s approach to de fining the action area under the provisions of the Overview Document (USEPA, 2004) considers th e results of the risk assessment process to establish boundaries for that action area with the understanding that exposures below the Agency’s defined LOCs constitute a no-effect th reshold. For the purpose s of this assessment, attention will be focused on the footprint of the action (i.e., the area where propoxur application occurs), plus all areas where offsite transport (i.e., spray drift, runoff, etc. ) may result in potential exposure that exceeds the Agency’s LOCs. Specific measures of ecological effect that define the-25 of 38- action area for listed species include any direct a nd indirect effects and/or potential modification of its critical habitat, including reduction in survival, gr owth, and reproduction as well as the full suite of sublethal effects available in the effects literature. Theref ore, the action area extends to a point where environmental exposures are below any measured lethal or subl ethal effect threshold for any biological entity at the whole organism, or gan, tissue, and cellular level of organization. In situations where it is not possible to determin e the threshold for an observed effect, the action area is not spatially limited and is assumed to be the entire United States.

7.8. Preliminary Identification of Data Gaps

7.8.1. Effects

The ecological effects data set fo r propoxur contains a number of ga ps for terrestr ial and aquatic animals and plants (Tables 5 – 7). Data gaps include the followi ng: avian acute dietary toxicity; avian reproductive toxicity, acute toxicity to saltwater fish, saltwater invertebrate acute toxicity, freshwater invertebrate life-cycle , and Tier I terrestrial and aquatic plant toxicity studies. Only terrestrial studies are being requested because EF ED assumes that aquatic exposure will not be a significant source of risk based on the use patt erns and usage of propoxur. Further information on ecological effects data required to fulfill th e Agency’s guideline requirements for propoxur is presented as the Data Call-in (DCI) table in A ppendix B. In addition to providing the guideline number and study title for required data, the DCI table provides a rationale for requiring the data, an explanation of how the data will be used, an d a brief description of the how the data could impact the Agency’s future decision-making.

Table 5. Ecological effects data for terrestrial animals exposed to pr opoxur and remaining data gaps. Guideline Description MRID/ Accession Classification Data Gap? Comments

00160000 Supplemental 850.2100 Avian oral toxicity 41625101 Acceptable No -

00149015 00149014 Supplemental

850.2200 Avian dietary toxicity 00022923 Supplemental Yes 1 Studies submitted by the registrant were classified as supplemental but do not satisfy the guideline requirements for the bobwhite quail or mallard duck. 00149017 Supplemental 850.2300 Avian reproduction 00149016 Supplemental Yes 1 According to the 40 CFR part 158, an avian reproduction study is required for a mallard

duck and a bobwhite quail.

850.3020 Honeybee acute contact toxicity 01006003 Acceptable No --26 of 38- Table 6. Available ecological effects data for aquatic animals exposed to propoxur and remaining data gaps. Guideline Description MRID/ Accession Classification Data Gap? Comments

00149171 Acceptable 40098001 Supplemental 44027705 Supplemental 44027704 Supplemental 44027703 Supplemental 04427702 Supplemental 44027701 Supplemental 850.1075 Freshwater fish – Acute toxicity

40098001 Supplemental No The registrant submitted study was classified as acceptable and provides data on both rainbow trout and bluegill fish.

850.1075 Saltwater fish – Acute toxicity 40228401 Supplemental Yes 2 The study from Mayer 1986 is classified as supplemental but does not satisfy the guideline requirements. 00149172 Acceptable 850.1010 Freshwater invertebrates – Acute toxicity 40098001 Supplemental No -

850.1025 850.1035 850.1045 850.1055 Saltwater invertebrates – Acute toxicity 40228401 Supplemental Yes 2 The study from Mayer 1986 is classified as supplemental but does not satisfy the guideline requirements.

850.1300 Freshwater invertebrate – life cycle test 41425301 Supplemental Yes 2 The reviewer classified the study as supplemental but stated that it did not meet the guideline criteria.

850.1350 Saltwater invertebrates – life cycle test N/A N/A CR Conditional data requirement based on the results of the acute

saltwater invertebrate toxicity

test. Data are generally not required for outdoor residential

uses unless data indicate that pesticide residues from the proposed uses can potentially enter waterways.

850.1400 Freshwater fish – early life stage test N/A N/A CR Data are generally not required for outdoor residential uses

unless data indicate that pesticide residues from the proposed uses can potentially enter waterways.

850.1400 Saltwater fish – early life stage test N/A N/A CR Conditional data requirement based on the results of the acute saltwater fish toxicity test

850.1500 Fish – life cycle test N/A N/A CR Conditional data requirement based on the results of the early life stage toxicity test CR = Conditionally required.-27 of 38- Table 7. Available ecological effects data for pl ants exposed to propoxur and remaining data gaps. Guideline Description MRID/ Accession Classification Data Gap? Comments

850.4100 Terrestrial plant toxicity: Tier I seedling emergence None NA Yes 1

850.4150 Terrestrial plant toxicity: Tier I vegetative vigor None NA Yes 1 Non-target terrestrial plant data are required at the Tier I level

850.4400 Aquatic plant toxicity with Lemna spp. None NA Yes 2

850.5400 Aquatic plant toxicity with algae None NA Yes 2 Non-target aquatic vascular and non-vascular plant data are required at the Tier I level
1 This study is anticipated to be required during registration review.

2 EFED assumes that aquatic exposure will not be a signifi cant source of risk based on the use patterns and usage of propoxur. Therefore, this study is not being required at this time.

7.8.1 Exposure

The environmental fate data set for propoxur cont ains a number of gaps . There is, however, no current need for environmental fate data as inpu ts to aquatic or terrestrial exposure assessment models. There is po tential ecological risk from the use of propoxur in soil, but it is unlikely that this use will cause risk to aquatic organisms from either runoff or spray drift. OPP will therefore require environmental chemistry analytical me thods for propoxur in soil but will not require them in water. New studies may be required if other outdoor uses are co nsidered in the future.

8. References

8.1. Cited Studies and Documents

American Conference of Governme ntal Industrial Hygienists, In c. 1986. Documentation of the threshold limit values and biological exposu re indices. Fifth edition. Cincinnati, OH: Publications Office, ACGIH.

Berg, G. L., ed. 1986. Farm Chemicals Handbook. Willoughby, Ohio: Meister Publishing Co.

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

Hayes, W. J. 1982. Pesticides studied in man. Baltimore, MD: Williams and Wilkins

Hoerger, F. and E. E. Kenaga, 1972. Pesticide Re sidues on Plants: Correlation of Representative Data as a Basis for Estimation of their Magnitude in the Environment. In F. Coulston and-28 of 38- F. Korte, eds., Environmental Quality and Safety: Chemistry, Toxicology, and Technology, Georg Thieme Publ., Stuttg art, West Germany, pp. 9-28.

TOXNET. 1986. National library of medicine's toxi cology data network. Hazardous Substances Databank. Public Health Service. National Institute of Health. U.S. Department of Health and Human Services. Bethesda, MD: NLM.

USEPA. 1975. Ney, Ronald E Jr . Registration – Baygon MOS Inse cticide. File No. 2075270 U.S. Environmental Protection Agency, Offi ce of Pesticide Programs, Environmental Fate and Effects Division. August 13, 1975.

USEPA. 1976. Ney, Ronald E Jr. For use on mole cricke t bait on lawn, golf courses, ornamental turfs, and pastures. U.S. E nvironmental Protection Agency, Office of Pesticide Programs, Environmental Fate and Effects Division. August 4, 1976.

USEPA. 1977a. Cook, N. Registration for Use around the house. File No. 5719-AA. U.S. Environmental Protection Agenc y, Office of Pesticide Progra ms, Environmental Fate and Effects Division. January 18, 1977.

USEPA. 1977b. Windberg, L.A. Amendmen t to Registration. File No. 3125-214, 3125-122, 3125-146. U.S. Environmental Protection Ag ency, Office of Pesticide Programs, Environmental Fate and Eff ects Division. November 23, 1977.

USEPA. 1977c. Windberg, L.A. and R.W. Holst. Amendment to Registration to Alfalfa and Pasture grass and Registra tion. File No. 3125-146 and 3125-GNA. U.S. Environmental Protection Agency, Office of Pesticide Pr ograms, Environmental Fate and Effects Division. November 22, 1977.

USEPA. 1977d. Sanders, F. Registration of SM CP Baygon 2% Mole Cricke t Bait Insecticide. File No. 6720-EAU. U.S. Environmenta l Protection Agency, Office of Pesticide Programs, Environmental Fate a nd Effects Division. January 13, 1977.

USEPA. 1977e. Windber g, Lamar A. Amendment to Registration – Barns. File No. 2075281. U.S. Environmental Protection Agency, Offi ce of Pesticide Programs, Environmental Fate and Effects Division. November 23, 1977.

USEPA. 1977f. O’Brien, Thomas F. Registra tion-Best Earwig and Sowbog Bait. File No. 2075278. U.S. Environmental Protection Ag ency, Office of Pesticide Programs, Environmental Fate and E ffects Division. August 5, 1977.

USEPA. 1977g. Ney, Ronald E Jr. Registration for control of ants, including fire ants + carpenter ants. File No. 2075277. U.S. E nvironmental Protection Agency, Office of Pesticide Programs, Environmental Fate and Effects Division. February 17, 1977.-29 of 38- USEPA. 1977h. Ney, Ronald E Jr. For use on al falfa and pasture grass to control mosquitoes. File No. 2075279. U.S. Environmental Protec tion Agency, Office of Pesticide Programs, Environmental Fate and Eff ects Division. September 21, 1977.

USEPA. 1977i. Cook, Norman J. Registration for Use aro und the house. File No. 2075274. U.S. Environmental Protection Agency, Offi ce of Pesticide Programs, Environmental Fate and Effects Division. January 18, 1977.

USEPA. 1978a. Craven, Henry T. Regi stration – Ant Trap. Acc No. 094546. U.S. Environmental Protection Agenc y, Office of Pesticide Progra ms, Environmental Fate and Effects Division. October 6, 1978.

USEPA. 1978b. Tice, John. Registration of Ne w Product – Grant’s Ant Control-Jel. Acc No. 232459. U.S. Environmental Protection Ag ency, Office of Pesticide Programs, Environmental Fate and Eff ects Division. October 27, 1978.

USEPA. 1983. Balcomb, R. Proposed Secti on 18 for use over flowing water to control mosquitoes. File No. 83-CA-76. U.S. Environmental Protection Agency, Office of Pesticide Programs, Environmental Fate and Effects Division. July 8, 1983.

USEPA. 1987. Noles, John. Propoxur Registration Standar d. Record No. 2075291 U.S. Environmental Protection Agenc y, Office of Pesticide Progra ms, Environmental Fate and Effects Division. May 5, 1987.

USEPA. 1990. Felthousen, R.W. Amendment- Label Revision-Data Re quired. DP Barcode 154393. U.S. Environmental Protection Ag ency, Office of Pesticide Programs, Environmental Fate and E ffects Division. August 15, 1990.

USEPA. 1991. Rexrode, Miachel. Label Revi ew for Registration. File No. 62451-R. U.S. Environmental Protection Agenc y, Office of Pesticide Progra ms, Environmental Fate and Effects Division. January 24, 1991.

USEPA.1996a.Food Quality Protection Act. http://www.epa.gov/oppsrrd1/registration_review/

USEPA. 1996b. Reregistration Eligibility Do cument for Propoxur, Science Chapter. U.S. Environmental Protection Agency, Office of Pesticide Programs. July 10, 1996.

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

USEPA. 2004. Overview of the Ecological Risk Assessment Proce ss in the Office of Pesticide Programs. U.S. Environmental Protection Ag ency, Office of Prevention, Pesticides and Toxic Substances, Office of Pesticide Programs, Washington DC. January 23, 2004.-30 of 38- USEPA. 2006. N-methyl Carbamate Revise d Cumulative Risk Assessment. U.S. Environmental Protection Agency, Office of Prevention, Pesticides and Toxic Substances, Office of Pesticide Prog rams, Washington DC. September 24, 2007.

USEPA. 2008a. ECOTOXicology Database. Office of Resear ch and Development National Health and Environmental Effects Research Laboratory’s (NHEER L’s) Mid-Continent Ecology Division (MED). June 30, 2008. http://cfpub.epa.gov/ecotox/

USEPA. 2008b. Ecological Incident In formation System. June 24, 2008. http://www.epa.gov/espp/consultation/ecorisk-overview.pdf

U.S. Environmental Protection Agency. 1986 (Jan). Estimating pesticide sorp tion coefficients for soils and sediments. Richard E. Green a nd Samuel W. Karickhoff. Environmental Research Laboratory. Office of Resear ch and Development. Athens, GA.

U.S. Environmental Protection Agency. 1984 (Dec.). User's manual for the pesticide root zone model (PRZM). Release 1. Athens, GA: Environmental Research Laboratory.

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

Worthing, C. R., ed. 1983. The pesticide manua l: A world compendium . Croydon, England: The British Crop Protection Council.

8.2. Submitted Effects Studies

MRID: 00022923. Hill, E.F.; Heath, R.G.; Spann, J.W.; et al. (1975) Lethal Dietary Toxicities of Environmental Pollutants to Birds: Speci al Scientific Report --Wildlife No. 191. (U.S. Dept. of the Interior, Fish and Wildlife Se rvice, Patuxent Wildlife Research Center; unpublished report).

MRID: 00036935. Atkins E.L.; E.A. Greywood, and R.L. Macdonald. 1975. Toxicity of pesticides and other agricultural chemicals to honey bees. Laboratory studies. University of California, Division of Agricu ltural Sciences. Leaflet 2287. 38p.

MRID: 00149014. Lamb, D. (1981) Acute Dietar y LC50 of Technical Propoxur (Baygon) to Mallard Ducks: Study No. 80-175-10: Mobay Report No. 69609. Unpublished study prepared by Mobay Chemical Corp. 10 p.

MRID: 00149015. Lamb, D. (1981) Acute Dietar y LC50 of Technical Propoxur (Baygon) to Bobwhite Quail: Study No. 80-175-06: M obay Report No. 80046. Unpublished study prepared by Mobay Chemical Corp. 9 p.-31 of 38- MRID: 00149016. Carlisle, J.; Carsel, M. (1982) Propoxur Reproduction Study with Mallard Duck: Study No. 81-675-06: Mobay Report No. 82265. Un- published study prepared by Mobay Chemical Corp. 55 p.

MRID: 00149017. Lamb, D.; Carsel, M. (1982) Propuxur Reproduction Study with Bob- white Quail: Study No. 81-675-04: Mobay Report No. 82269. Un- published study prepared by Mobay Chemical Corp. 58 p.

MRID: 00149171. Lamb, D. (1981) Acute Toxicity of Technical Propoxur (Baygon) to Bluegill and Rainbow Trout: Study Nos. 81-066-02 and 80-066-11. Unpublishe d study prepared by Mobay Chemical Corp. 9 p.

MRID: 00149172. Lamb, D. (1981) Acute Toxicity of Technical Propoxur (Baygon) to Daphnia magna: Study No. 81-067-01. Unpublished study pr epared by Mobay Chemical Corp. 9p.

MRID: 00152443. Flucke, W. (1980) Boe 5812315 (Pr opoxur) Acute Toxicity Studies: Report No: 9295. Unpublished study prepared by Bayer AG. 7 p.

MRID: 00158414. Heimbach, F. (1985) Growth Inhibition of Green Algae (Scenedesmus subspicatus) by Propoxur (Technical): Re port HBF/A106. Unpub- lished Mobay Report No. 89080 prepared by Bayer AG. 18 p.

MRID: 00160000. Hudson, R.H., R.K. Tucker and M.A. Haegele. (1984) Handbook of toxicity of pesticides to wildlife. USDI Resource Publication No. 153. Wa shington, DC. 92 pp.

MRID: 40228401. Mayer, F.L. (1986) Acute toxicity handbook of chemicals to estuarine organisms. USEPA, Environm ental Research Lab, Gulf Br eeze, FL. EPA/600/X-86/231. 275 pp.

MRID: 40098001. Mayer, F.L. and M.R. Ellersie ck. (1986) Manual of acute toxicity: Interpretation and data base for 410 chemi cals and 66 species of freshwater animals. USDI, FWS Publication 160, Washington, DC. 506 p.

MRID: 40836401. Sheets, L. (1988) Acute Dermal Toxicity of Technical Grade Baygon in Rabbits: Study No. 88-023-AQ. Unpublishe d study prepared by Mobay Corp. 19 p.

MRID: 40836402. Pauluhn, J. (1988) Study of the Acut e Inhalation Toxicity in Accor- dance with OECD Guideline No. 403: BOQ 5812 315 (Propoxur): Re- port No. 98291. Unpublished study prepared by Bayer AG. 83 p.

MRID: 41425301. Surprenant, D. (1988) The Chroni c Toxicity of Technical Grade Propoxur (TradeName Baygon) to Daphnia magna under Flow-through Conditions: Final Report: Final Report: Report #87-7-2474: SLS Study #274.0986.6123/130. Unpublished study prepared by Spring- born Life Sciences. 47 p.-32 of 38- MRID: 41625101. Campbell, S. (1990) An Acute Oral Toxicity Study with the Northern Bobwhite: Baygon 2% Bait (Encapsulated) : Lab Project Number: 149-159: 100240. Unpublished study prepared by Wildlife Intern- ational Ltd. 21 p.

MRID: 42615403. Dotti, A.; Kinder, J.; Bieder mann, K.; et al. (1992) Two-generation Reproduction Study in Rats: BOQ 5812315: Lab Project Number: 286997: T 5039706. Unpublished study prepared by Research & C onsulting Co. Ltd. and Biological Research Labs Ltd. 734 p.

MRID: 44027701. US EPA (1977) Biological Report of Analysis: Baygon 70% Wettable Powder: Brook Trout (Salvelinus fontinalis): Static Jar Test 1106. Unpublished study. 1p.

MRID: 44027702. US EPA (1975) Report of Analys is: Baygon 2% Bait Insecticide: Bluegill: (Lepomis macrochirus): Static Jar Test 883. Unpublished study. 1 p.

MRID: 44027703. US EPA (1977) Biological Report of Analysis: Baygon 70% Wettable Powder: Bluegill (Lepomis macrochirus): Static Jar Test 1115. Unpublished study. 1 p.

MRID: 44027704. US EPA (1977) Biological Report of Analysis: Baygon Technical: Bluegill (Lepomis macrochirus): Static Jar Test 1119. Unpublished study. 1 p.

MRID: 44027705. US EPA (1975) Report of Analys is: Baygon 2% Bait Insecticide: Rainbow Trout (Salmo gairdneri {Oncorhynchus mykiss} ): Static Jar Test 905. Unpublished study. 1 p.-33 of 38- Appendix A. The Risk Quotient Method and Levels of Concern

The Risk Quotient Method is the means used by EFED to integrate the results of exposure and ecotoxicity data. For this method, Risk Quo tients (RQs) are calculated by dividing exposure estimates by the acute and chronic ecotoxicity values (i.e., RQ = EXPOSURE/TOXICITY). These RQs are then compared to OPP's levels of concern (LOCs). These LO Cs are criteria used by OPP to indicate potential risk to non-target organisms and the need to consider regulatory action. EFED has defined LOCs for acute risk, pot ential restricted use classification, and for endangered species.

The criteria indicate that a pes ticide used as directed has the pot ential to cause adverse effects on non-target organisms. LOCs currently address the following risk presumption categories:

(1) acute - there is a potential for acute risk; regulatory action may be warranted in addition to restricted use classification;

(2) acute restricted use - the poten tial for acute risk is high, but this may be mitigated through restricted use classification;

(3) acute endangered species - the potential for acute risk to endangered species is high, regulatory action may be warranted; and

(4) chronic risk - the potential for chronic risk is high, regula tory action may be warranted.

Currently, EFED does not perform assessments fo r chronic risk to plants, acute or chronic risks to non-target insects, or chronic risk fr om granular/bait formulations to mammalian or avian species.

The ecotoxicity test values (i.e., measurement e ndpoints) used in the acute and chronic RQs are derived from required studies. Examples of eco toxicity values deri ved from short-term laboratory studies that assess acute effects are: (1) LC50 (fish and birds), (2) LD50 (birds and mammals), (3) EC50 (aquatic plants and aquatic invertebrates), and (4) EC25 (terrestrial plants). Examples of toxicity te st effect levels derived from the results of long-term laboratory studies that assess chronic effects are: (1) the Lowest Observed Adverse Effect Concentration (LOAEC) (birds, fish, and aquatic invertebrate s), and (2) the No Observed Adverse Effect Concentration (NOAEC) (birds, fish and aquati c invertebrates). The NOAEC is generally used as the ecotoxicity test value in assessing chroni c effects. Risk presumptions, along with the corresponding RQs and LOCs are summarized in Table B1.-34 of 38- Table A1. Agency risk quotient (RQ) metrics and levels of concern (LOC) per risk class.

Risk Class Risk Description RQ LOC
Aquatic Animals (fish and invertebrates)

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

60-day EEC/NOEC (fish) Chronic Potential for effects to non-listed and listed animals from chronic exposures 21-day EEC/NOEC (invertebrates) 1

Terrestrial Animals (mammals and birds)

EEC 2 /LC 50 (Dietary) Acute Potential for effects to non-listed animals from acute
exposures EEC/LD 50 (Dose) 0.5

EEC 2 /LC 50 (Dietary) Acute Restricted Use Potential for effects to an imals from acute exposures Risks may be mitigated through restricted use classification EEC/LD 50 (Dose) 0.2

EEC 2 /LC 50 (Dietary) Acute Listed Species Listed species may be potentially affected by acute
exposures EEC/LD 50 (Dose) 0.1

Chronic Potential for effects to non-listed and listed animals from chronic exposures EEC 2 /NOAEC 1

Plants
Non-Listed Potential for effects to non-target, non-listed plants from
exposures EEC/ EC 25 1

EEC/ NOEC Listed Plant Potential for effects to non-target, listed plants from
exposures EEC/ EC 05 1

1 LC 50 or EC 50 . 2 Based on upper bound Kenaga values.-35 of 38- Appendix B. Data Call-In Table for Propoxur

The following Data Call-In (DCI) tables include ra tionales for requiring the da ta requested in this problem formulation, explanations of the utility of the data, and explana tions for how the data might impact risk assessment.

Guideline Number: 835.6100 (7) Data requirement: Environmental Chem istry Analytical Met hods / independent laboratory validation -- soil Rationale for Requiring the Data

Independently validated analytic al methods for residues in soil , water, and plant material (environmental chemistry methods) submitted by the registrant are used to evaluate analyses described in submitted environmental fate and ecological effects studies. Submitted analytical methods are also used by various federal, state, tribal, and local agencies to detect and monitor residues th at are suspected to be in environmental compartments due to outdoor uses and accident al releases. Theref ore, availability of these analytical methods is necessary to ensure the safety of those in proximity to releases of propoxur residues in the environment. Independent laboratory validations for submitted analytical methods are necessary to confirm the levels of detection and quantitation reported in regi strant-prepared validations.

Practical Utility of the Data

How will the data be used? In the absence of independently validate d environmental chemistry methods, submitted environmental fate and ecological effects data may not be reviewable and entities outside the Agency may lack chemical-specific methods for analyses in environmental compartments. Independently validated envi ronmental chemistry methods will be used to evaluate the submitted environmental fate and ecological effects data and will be made available to the public to suppor t monitoring for propoxur residues.

How could the data impact the Ag ency’s future decision making? Risk assessment conclusions could be altere d if they are not supported by either study data or environmental monitoring detections that are based on i ndependently validated environmental chemistry methods. Furthermor e, while not directly related to Agency decision making, independently validated environmental chemistry methods are necessary to ensure the safety of those in proximity to releases of propoxur residues in the environment.-36 of 38- Guideline Number: 850.2200 Study Title: Avian Dietary Toxicity Test (Bobwhite and Mallard) Rationale for Requiring the Data

Studies previously submitted by the registrant in support of this guideline have either been classified as invalid or supplemental. The supplemental studies do not satisfy the guideline and are not upgradeable based on flaws in their experimental design.

These data are designed to pr ovide information on the dietary toxicity of pesticides to birds. Birds are exposed to diffe rent levels of pesticides in th eir diet for 5 days of feeding and a dose response curve is determined. The current use of propoxur that is being assessed for risk is a 2% granul ar bait application. The inform ation contained in this type of study is essential to determine the toxi city of propoxur to birds that may ingest propoxur granules. As shown by the incident re ports, this type of exposure has already resulted in bird mortality.

Practical Utility of the Data

How will the data be used? As part of registration review, the Agen cy plans to conduct a new ecological risk assessment including an endangered species a ssessment for propoxur. In the absence of this data, no dietary RQ’s can be calculated to assess the risk to birds, and the Agency would have to assume that propoxur “may aff ect” birds, and those taxa for which birds are a surrogate, directly (a nd endangered species from other taxa indirectly).

How could the data change the Agency’s d ecision or impact the Agency’s future decision-making? Open literature studies may provide additional information, but they cannot be used to fulfill guideline requirements. The data ar e required according to the 40 CFR guidelines for an upland and waterfowl species. Open literature studies classify the chemical as highly toxic to very highly toxic to birds, whereas registrant submitted studies classify propoxur as slightly to practical ly non-toxic. Given the flaw s in the experimental design of the registrant submitted studies, the da ta from new studies will provide a more accurate assessment of the toxicity of propoxur to avian species and allow the Agency to refine the risk to avian speci es and those species for whic h birds are a surrogate. In addition, the lack of these data will limit the fl exibility the Agency and registrants have in coming into compliance with the Endangered Species Act, and could result in use restrictions for propoxur, which may otherwis e be avoided or whic h are unnecessarily

severe.-37 of 38- Guideline Number: 850.2300 Study Title: Avian Reproduction (Bobwhite and Mallard) Rationale for Requiring the Data

Since the RED was signed, the Agency has work ed to finalize its update to the data requirements in 40 CFR part 158, which were promulgated in October 2007. Now two avian reproduction studies, one with a waterf owl and one with an upland game bird, are required to support all terre strial use patterns.

Propoxur is applied in granular form around residential, commercial, and industrial structures. Both listed and non-listed birds may come into contact with this granular formulation. This data is necessary to provide information on th e potential reproductive effects to both listed and non-listed species.

The registrant previously provided two studies on avia n reproduction toxicity, which were both classified as supplemental. However, the Bobwhite quail study did not establish a NOEC, which is important to asse ssing chronic risk to avian species. The mallard duck study did not satisfy the guide line requirement although it did suggest reproductive toxicity of propoxur to mallard ducks. New acceptable Bobwhite quail and mallard duck studies are needed to refine th e reproductive risk to avian species due to environmental exposure to propoxur accordi ng to the 40 CFR part 158 requirements for all outdoor uses.

Practical Utility of the Data

How will the data be used? These data are necessary to characterize the potential risks to birds, terrestrial-phase amphibians and reptiles associated with the use of propoxur. These data will be used in the national-level risk assessment to estimate th e scope of sub-lethal effects and potential chronic risks associated w ith the use of propoxur.

How could the data impact the Agency’s future decision-making? The data from the bobwhite and mallard repr oductive toxicity studi es will clarify the reproductive toxicity of propoxur, which is al ready suggested by one of the previously submitted studies, to birds, terrestrial-phase amphibians and reptiles. This information could further refine the risk assessment to th ese wildlife taxa that are both listed and nonlisted. The lack of these data will limit the flexibility the Agency and registrants have in coming into compliance with the Endangered Species Act, and could result in use restrictions for propoxur which may otherwis e be avoided, or whic h are unnecessarily

severe.-38 of 38- Guideline Number: 850.4225, 850.4250 Study Title: Terrestrial Plant Toxicity: Tier II Seedling Emergence and Vegetative Vigor Rationale for Requiring the Data

Propoxur toxicity data for non-target terrestrial and aquatic plants are not available. Based on the 40 CFR Part 158 data requirement s, Tier I level seedling emergence and vegetative vigor non-target terrest rial plant data are required for all outdoor uses. Minor incidents have been reported that suggests propoxur has phytotoxic properties. Given this evidence, Tier II seedling emergence and vegetative vigor studies are being requested.

Practical Utility of the Data

How will the data be used? Data from Tier II plant toxicity studies will be used to estimate potential risks to terrestrial plants associated with the use of propoxur. The data will reduce uncertainties associated with the current risk assessment for terrestrial plants and will improve the Agency’s understanding of the potential e ffects of propoxur on terrestrial and aquatic plants. In the absence of this data, risk for terrestrial plants will be presumed.

How could the data impact the Agency’s future decision-making? Because terrestrial plants form the basis of the food chain for terr estrial habitats and significantly contribute to overa ll habitat quality, a solid understanding of the potential risks to terrestrial plants is essential for sound environmental risk management decisionmaking. Without terrestrial plant data for propoxur, the Agency cannot determine if the current application rates of propoxur may result in direct adverse effects to terrestrial plants and/or indirect effect s resulting from reduction in th e prey base and/or loss of habitat/cover. Previous applic ations of propoxur have already resulted in minor incidents of plant damage as reported in the aggregat e minor incident reports (section 4.4), which suggests the possibility of phytotoxic effects related to propoxur exposure. If future endangered species risk assessments are perf ormed without these data, the Agency would have to assume that propoxur “may affect” terr estrial plants directly (and listed species from other taxa indirectly via reduction in prey base and/or hab itat), and use of propoxur may need to be restricted in areas where list ed species could be e xposed and/or critical habitat is present. The lack of these data will limit the flexibility the Agency and registrants have in coming into compliance with the Endangered Species Act and could result in use restrictions for propoxur which are unnecessarily severe.