UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON, D. C. 20460 OFFICE OF PREVENTION, PESTICIDES AND TOXIC SUBSTANCES PC Code No.: 014505 DP Barcode: D 305863 Date: June 21, 2005 MEMORANDUM SUBJECT: Environmental Fate and Ecological Risk Assessment for Maneb, Section 4 Reregistration for Control of Fungal Diseases on Numerous Crops, Ornamental Plantings, and Turf ( Phase 3 Response).

TO: Michael Goodis, Branch Chief Tawanda Spears, Chemical Review Manager Special Review and Reregistration Division ( 7508C)

FROM: ERB V Team for EBDCs: Gabe Patrick, Biologist, Ecological Effects Reviewer M. A. Ruhman, Ph. D., Agronomist, Environmental Fate Reviewer Ronald Parker, Ph. D., Environmental Engineer, Environmental Fate Reviewer Environmental Fate and Effects Division ( 7507C)

THROUGH: Mah T. Shamim, Ph. D., Chief Environmental Risk Branch V Environmental Fate and Effects Division ( 7507C)

The EFED screening level Environmental Risk Assessment is attached. This RED document should be considered with the ETU document, the degradate of concern for metiram.

The following is an overview of our findings:

Risk Summary Based on available data, EFED expects all maneb's uses to present potential chronic risks to birds and mammals. EFED relied on a referenced total foliar dissipation half life value of 3.2 days from Willis and McDowell, 1987 to evaluate exposure to terrestrial organisms. Avian chronic LOCs are exceeded for all use patterns. RQs range from a high of 265 from the turf use to a low of 0.4 from maneb's uses on collards, turnips, and mustard ( Georgia and Tennessee, only). Mammalian chronic LOCs are exceeded for all uses patterns. RQs range from a high of 71 from the turf use to a low of 0.1 from maneb's uses on collards, turnips, and mustard ( Georgia and Tennessee, only). EFED does not calculate risk quotients to conduct risk assessments on terrestrial invertebrates. Based on the lack of acute maneb toxicity to honeybees, EFED expects a low acute risk to nontarget terrestrial 1 In this document three important abbreviations are used: Parent maneb, maneb complex and Bound species. Parent maneb is the polymeric parent maneb present in the active ingredient. Maneb complex is a suite of multi species residues resulting from degradation of the polymeric parent maneb. The suite includes the following: ( a) species reported to be present but not specifically identified: variable/ low molecular weight polymeric chains ( i. e polymer fragments), monomeric species, and EBDC ligand in association with other metal ions that might be present in the environment; ( b) species identified and quantified: Transient species, ETU and ETU degradates; and ( c) un identified species that bound to soil and sediment particles ( referred to as Bound species).

2 insects. Due to lack of data EFED did not assess risks to terrestrial plants or fully assess risks to aquatic plants. In the aquatic environment, EFED concludes maneb complex will present a potential acute risk to freshwater/ estuarine/ marine fish and invertebrates as well as nonvascular aquatic plants. EFED selected representative maneb use patterns at maximum application rates and minimum intervals between applications for aquatic modeling. Maneb is used on more than 20 different crop groupings. The representative sites selected for aquatic modeling were apples, peppers, potatoes ( Maine, only) and tomatoes. The acute RQs exceeding freshwater fish acute, acute restricted use, and acute endangered species LOCs for all maneb's modeled uses range from 1.13 to 4.71. The acute freshwater invertebrates' RQs exceeding acute restricted use, and acute endangered species LOCs for all maneb's modeled uses range from 0.40 to 1.65. The acute estuarine/ marine fish RQs exceed acute restricted use, and acute endangered species LOCs for all maneb's modeled uses with RQs ranging from 0.47 to 1.1. Estuarine/ marine invertebrate acute RQs exceed acute, acute restricted use, and acute endangered LOCs for all maneb's modeled uses with RQs ranging from 15.87 to 65.97. Based on data for one surrogate species, maneb's modeled use patterns exceed acute risk LOCs for nonvascular aquatic plants with acute RQs ranging from 3.55 to 14.77. EFED did not assess chronic risks to freshwater invertebrates, estuarine/ marine fish, or estuarine/ marine invertebrates due to lack of data.

Risk to the Water Resources Maneb is non persistent in most of the natural environments. It is expected to decompose rapidly ( to < 10% of the applied within one day) by hydrolytic reactions in the main compartments of the natural environment. Among the EBDCs, maneb is characterized by the highest vulnerability to hydrolysis while metiram is the lowest. The degradate of concern in the process of maneb decomposition is ETU, a B2 carcinogen. Therefore, risk assessment for the water resource from the common EBDCs degradate ETU was performed for the application of all EBDCs including maneb. The reader is referred to the accompanied ETU chapter for this assessment.

Uncertainties ( 1) Environmental Fate EECs for parent maneb1 were estimated for water bodies using hydrolysis half lives. The same water hydrolysis half lives were used for soils assuming sufficient moisture is available in soil pores for hydrolysis to occur at the same rate. Uncertainty exists on whether half lives used are applicable because of uncertainty related to soil moisture availability; soil moisture level is expected to impact resultant EECs. Lower EECs are expected in irrigated and/ or rain fed soils with high water holding capacity ( WHC) and higher EECs are expected in low WHC soils under dry conditions. Given the 3 fact that maneb is highly vulnerable to hydrolysis and that it is applied to growing crops, moisture is expected to be available for parent to hydrolyze at an adjusted rate near or just below that determined from aqueous hydrolysis half lives.

EECs for maneb complex were estimated using the physicochemical properties and hydrolysis halflives of parent maneb in addition to aerobic soil metabolism half lives and sorption coefficients which were assigned to this complex rather than the parent. In all aerobic soil studies two separate sets of determinations were conducted: the first was to obtain data for calculating half lives using the CS 2  method to quantify the parent while the second was to characterize the bio degradation process. EFED believes that half lives calculated from the first set of determinations represent hydrolytic decomposition of parent maneb rather than bio degradation. Rapid degradation of parent maneb produces a residue, the maneb complex, which appears to be affected by slow degradation as indicated by production of CO 2 . Part of this complex may contain precursor( s) for the degradate of concern, ETU. Therefore, EFED used the second set of determinations ( radioactivity data) for calculating half lives and assigned it to the maneb complex. Uncertainty exists in these residue halflives as they are conservative and affected by the validity of the assumption that the only biodegradation of the residue was represented by evolved CO 2 . Data obtained on degradates were not used as it were affected by impurities in the test materials, hydrolytic reactions and possible artificial degradation during extraction.

In this RED, aerobic soil half lives calculated from the CS 2  method are considered to represent hydrolysis of parent maneb into its complex as modified by soil conditions ( i. e. moisture content, pH and O 2 concentration). In contrast, half lives calculated from evolved CO 2 are considered to represent bio degradation of maneb complex left in the soil which appears to occur in parallel with hydrolytic decomposition of the parent. Likewise, calculated adsorption/ desorption characteristics ( K d and K oc ) are thought to represent maneb complex as it were approximated from column leaching; with no 1/ n value to indicate the degree of non linearity for the Freundlich constant.

In the degradation process for maneb Mn ions/ salts are expected to dissipate into the environment. Although EFED recognizes that Mn is a micronutrient, no data were presented to evaluate the risk that might be associated with this release in certain environmental settings and therefore, uncertainty exists in this aspect of risk assessment.

( 2) Ecological Effects EFED is uncertain about maneb's acute risk to nontarget terrestrial plants and needs testing performed at maneb's maximum rate of application in the environment. EFED has not received studies to evaluate the acute risk of maneb complex to vascular aquatic plants and is uncertain about this risk. EFED has received one acute study for 1 of 4 surrogate species needed to evaluate the acute risk to nonvascular aquatic plants. This one study when compared to maneb complexes' exposure showed the acute RQs exceeded LOCs. EFED needs testing performed on 3 more surrogate species to evaluate fully the acute risk to nonvascular aquatic plants. EFED has no data to evaluate the chronic risks to freshwater invertebrates or estuarine/ marine organisms and is uncertain about these risks. 4 Endocrine Disruption Maneb toxicity effects noted in both birds and mammals could be a result of hormonal disruptions. The avian reproductive studies reviewed by EFED noted reproductive effects. These effects in mallard duck were decreases in the number of hatchlings as percentages of eggs laid, eggs set, and live 3 week old embryos, and a decrease in the number of 14 day old survivors as a percentage of eggs. For mammals chronic effects were noted such as male parental toxicity resulting in significant increase in lung weight ( both generations) and liver weight ( F1 generation) with lesions noted on these organs in the F1 generation. Chronic testing in freshwater fish showed decreased hatchability, fish survival and length of fry. When the appropriate screening and or testing protocols being considered under the Agency's Endocrine Disruptor Screening Program have been developed, maneb may be subjected to additional screening and or testing to better characterize effects related to endocrine disruption.

Data Gaps Environmental Fate Complete characterization of the fate of maneb complex requires more information on the various species that constitute its complex including the soil/ sediment bound species. Information needed are for each of these constituents and include: their physicochemical properties and the nature of their association with soil/ sediment particles. Furthermore, several problems were identified in submitted fate studies for the EBDCs including maneb. These problems are presented in detail in Appendix I; the registrant is requested to address these problems.

Full characterization of the processes involved in parent maneb dissipation requires additional information on the release of Mn ions from maneb in order to evaluate possible environmental risk that might be associated with such release in specific environmental settings.

The following Table lists the status of the fate data requirements for maneb. In the Table, Hydrolysis, adsorption/ desorption and leaching studies are listed as supplemental however, no new studies are required because problems found in these studies are mostly associated with the unique characteristics of this chemical in aqueous media. Not all the requirements of these guideline studies can be met due to the high susceptibility of this chemical to hydrolysis. In contrast, aerobic soil studies are classified as supplemental mainly because of incomplete characterization of the significant bound species. Without a complete characterization of this bound species, EFED was only able to estimate conservative half lives based on complete mineralization of maneb into CO 2 . The issues of the bound species and use of CS 2 data are presented in detail elsewhere in this document ( section IV. b. iv); the registrant is requested to address these issues. A high tier targeted monitoring study was submitted for ETU, the degradate of concern for all EBDCs including maneb, therefore, no new terrestrial field dissipation study is required at this time. 5 Status of environmental data requirements for maneb Guideline Number Data Requirement Is Data Needed? MRID Number Study Classification 161 1 835.2 Hydrolysis 1 No 453936 01 Supplemental 161 2 835.2 Photo Degradation in Water 2 No 404656 02 Acceptable 161 3 835.2 Photo Degradation on Soil No 404656 03 Acceptable 162 1 835.4 Aerobic Soil Metabolism Reserved 405852 01 Supplemental 451452 02 162 2 835.4 Anaerobic Soil No 3 405852 02 Not Acceptable 162 3 835.4 Anaerobic Aquatic Metabolism No 001633 35 Acceptable 162 4 835.4 Aerobic Aquatic Metabolism No Studies submitted 163 1 835.1230 Adsorption/ Desorption 4 No 050011 90 Supplemental 835.1240 Leaching 5 No 405852 03 Supplemental 400472 01 455959 01 455959 02 163 2 Laboratory Volatility Waived; although a study was submitted ( MRID 001549 86; No DER)

164 1 835.6 Terrestrial Field Dissipation 6 No 000889 23 Supplemental 417430 01 417430 02 201 1 840.1 Droplet Size Spectrum A study was submitted ( MRID 424343 01; No DER)

165 4 850.2 Accumulation in Fish Waived 1 Two studies were rejected ( Accession No. 2552 29 and MRID 420701 01). One study was considered to contain Ancillary information ( MRID 404656 01). One article on hydrolysis was submitted under MRID 000889 17. 2 MRID 420701 02 was rejected. Two articles on photolysis were submitted under MRIDs 000889 17 and 001540 26. 3 The study was rejected but requirement was satisfied by submitting an anaerobic aquatic study ( MRID 001633 35). 4 The same study was submitted under MRID 000658 59. 5 No DER was found for one study submitted under two MRIDs 001428 87 and 001428 88. 6 No DER was found for a study submitted under MRID 001619 35. 6 Ecotoxicity EFED is uncertain about maneb's acute risk to aquatic and terrestrial plants because EFED lacks toxicity data for some or all surrogate species representing these groups. Because EFED lacks chronic maneb toxicity data, EFED is uncertain about the chronic risks to freshwater invertebrates and estuarine/ marine organisms. EFED needs studies to evaluate these uncertainties. EFED needs whole sediment acute toxicity testing on freshwater and estuarine/ marine invertebrates because maneb residue is toxic to aquatic invertebrates, binds to sediment , and may persist on sediment surfaces. In some risk evaluations EFED has used supplemental studies to make a risk determination. EFED needs core studies to confirm these findings.

The following Table lists the status of the ecological data needs for maneb.

Status of ecological data needs for Maneb.

Date: December 14, 2001 Case No: 0643 Chemical No: 014505 MANEB DATA NEEDS FOR THE ENVIRONMENTAL FATE AND EFFECTS DIVISION Data Requirement Composition1 Use Pattern1 Does EPA Have Data To Satisfy This Need? Bibliographic Citation Study Classification Must Additional Data Needed Under FIFRA 3( c)( 2)( B)?

§ 158.490 WILDLIFE AND AQUATIC ORGANISMS ( 6 Basic Studies in Bold)

71 1( a) Acute Avian Oral, Quail/ Duck TGAI 1,2,3,9,11 Yes 40657001 Core No 71 1( b) Acute Avian Oral, Quail/ Duck ( TEP) 1,2,3,9,11 No not applicable not applicable No 71 2( a) Acute Avian Diet, Quail TGAI 1,2,3,9,11 Yes 00104264 Supplemental No 71 2( b) Acute Avian Diet, Duck TGAI 1,2,3,11 Yes 40657002 00098561 Core Supplemental No 71 3 Wild Mammal Toxicity 1,2,3,9,11 No not applicable not applicable No 71 4( a) Avian Reproduction Quail TGAI 1,2,3,11 Yes 43586501 Supplemental No 71 4( b) Avian Reproduction Duck TGAI 1,2,3,11 Yes 43586502 Core No 71 5( a) Simulated Terrestrial Field Study 1,2,3,9,11 No not applicable not applicable No 71 5( b) Actual Terrestrial Field Study 1,2,3,9,11 No not applicable not applicable No 72 1( a) Acute Fish Toxicity Bluegill TGAI 1,, 2,3,11 Yes 40749401 00097240 00090291 Core Supplemental Supplemental No 72 1( b) Acute Fish Toxicity Bluegill ( TEP) 1 Yes 40749401 00052557 Core Supplemental No2 Date: December 14, 2001 Case No: 0643 Chemical No: 014505 MANEB DATA NEEDS FOR THE ENVIRONMENTAL FATE AND EFFECTS DIVISION Data Requirement Composition1 Use Pattern1 Does EPA Have Data To Satisfy This Need? Bibliographic Citation Study Classification Must Additional Data Needed Under FIFRA 3( c)( 2)( B)?

7 72 1( c) Acute Fish Toxicity Rainbow Trout TGAI 1,2,3,9,11 Supplemental 40706001 Supplemental Yes3 72 1( d) Acute Fish Toxicity Rainbow Trout ( TEP) 1 Supplemental 40706001 Supplemental Yes2,3 72 2( a) Acute Aquatic Invertebrate TGAI 1,2,3,9,11 Yes 40749402 Core No 72 2( b) Acute Aquatic Invertebrate ( TEP) 1 Yes 40749402 Core No2 850.1735 Whole Sediment Acute Toxicity Freshwater Invertebrates) TGAI 1,2,3,9,11 No Not applicable Not applicable Yes 72 3( a) Acute Est/ Mar Toxicity Fish TGAI 1,2,3,11 Yes 40943101 Core No 72 3( b) Acute Est/ Mar Toxicity Mollusk TGAI 1,2,3,11 Yes 41000001 Core No 72 3( c) Acute Est/ Mar Toxicity Shrimp TGAI 1,2,3,11 Supplemental 41000002 Supplemental Yes4 850.1740 Whole Sediment Acute Toxicity Invertebrates, Est/ Mar TGAI 1,2,3,11 No Not applicable Not applicable Yes 72 3( d) Acute Est/ Mar Toxicity Fish ( TEP) 1 Yes 40943101 Core No2 72 3( e) Acute Est/ Mar Toxicity Mollusk ( TEP) 1 Yes 41000001 Core No2 72 3( f) Acute Est/ Mar Toxicity Shrimp ( TEP) 1 Supplemental 41000002 Supplemental Yes2,4 72 4( a) Early Life Stage Fish ( Freshwater) TGAI 1,2,3,11 Yes 41346301 Core No 72 4( a) Early Life Stage Fish ( Estuarine) TGAI 1,2,3,11 No Not applicable Not applicable Yes 72 4( b) Life Cycle Invertebrate ( Freshwater) TGAI 1,2,3,11 No Not applicable Not applicable Yes 72 4( b) Life Cycle Aquatic Invertebrate ( Estuarine) TGAI 1,2,3,11 No Not applicable Not applicable Yes 72 5 Life Cycle Fish TGAI 1,2,3,11 No Not applicable Not applicable Yes freshwater Reserved Date: December 14, 2001 Case No: 0643 Chemical No: 014505 MANEB DATA NEEDS FOR THE ENVIRONMENTAL FATE AND EFFECTS DIVISION Data Requirement Composition1 Use Pattern1 Does EPA Have Data To Satisfy This Need? Bibliographic Citation Study Classification Must Additional Data Needed Under FIFRA 3( c)( 2)( B)?

8 72 6 Aquatic Organism Accumulation TGAI 72 7( 1) Simulated Aquatic Field Study 1,2,3,9,11 No not applicable not applicable No 72 7( b) Actual Aquatic Field Study 1,2,3,9,11 No not applicable not applicable No § 158.540 PLANT PROTECTION 122 1( a) Seed Germ./ Seedling Emerg. Tier I ( TEP) 1,2,3,11 No not applicable not applicable Recommended 122 1( b) Vegetative Vigor Tier I ( TEP) 1,2,3,11 No not applicable not applicable Recommended 122 2 Aquatic Plant Growth Tier I ( TEP) 1,2,3,11 No not applicable Not applicable Yes6 123 1( a) Seed Germ./ Seedling Emerg. Tier II ( TEP) 1,2,3,11 No not applicable not applicable Reserved 123 1( b) Vegetative Vigor Tier II ( TEP) 1,2,3,11 No not applicable not applicable Reserved 123 2 Aquatic Plant Growth Tier II ( TEP) 1,2,3,11 Partial 40943501 Core Yes5 124 1 Terrestrial Field Study 1,2,3,9,11 No not applicable not applicable No 124 2 Aquatic Field Study 1,2,3,9,11 No not applicable not applicable No § 158.490 NONTARGET INSECT TESTING 141 1 Honey Bee Acute Contact not reported 1,2,3,11 Yes 00036935 Core No 141 2 Honey Bee Residue on Foliage ( TEP) 1,2,3,11 No not applicable not applicable No 141 5 Fueld Test for Pollinators ( TEP) 1,2,3,11 No not applicable not applicable No FOOTNOTES:

1. 1= Terrestrial Food; 2= Terrestrial Feed; 3= Terrestrial Non Food; 4= Aquatic Food; 5= Aquatic Non Food( Outdoor); 6= Aquatic Non Food ( Industrial); 7= Aquatic Non Food ( Residential); 8= Greenhouse Food; 9= Greenhouse Non Food; 10= Forestry; 11= Residential Outdoor; 12= Indoor Food; 13= Indoor Non Fod; 14= Indoor Medicinal; 15= Indoor Residential. TGAI= Technical grade of the active ingredient; PAIRA= Pure active ingredient, radiolabeled; TEP= Typical end use product 2. TEP testing was required to support the cranberry use ( 1988 Maneb Registration Standard). The registrant requested that testing of the 80% WP formulation satisfy both TEP and TGAI testing requirements because 1) the TGAI was only 87% pure and not soluble in water; ( 2) the 80 WP formulated product was 80% pure and suspendable in water. EFED agreed to allow testing with the 80% WP to satisfy both TEP and TGAI tsting 9 requirements.

3. Study was classified supplemental because of high variability in measured test concentrations, weights of fish not given; O 2. less than recommended; study should have been conducted as a flow through. Study must be repeated.

4. Study was classified supplemental because of high variability in measured concentrations; also analytical procedures were not able to detect concentrations below 5 ppb. Study must be repeated.

5. Suplemental study. Results were based on nominal which averaged 15% of nominal at 120 hours. Five species need to be tested.

6. Tier I or Tier II aquatic plant growth testing needs to be submitted for duckweed ( Lemna gibba), marine diatom ( Skeletonema costatum), bluegreen algae ( Anabaena flos aquae), and a freshwater diatom for maneb.

Environmental Hazards Labeling Statements for Maneb Manufacturing Use Do not discharge effluent containing this product into lakes, streams, ponds, estuaries oceans or other waters unless in accordance with the requirements of a National Pollutant Discharge Elimination System ( NPDES) permit and the permitting authority has been notified in writing prior to discharge. Do not discharge effluent containing this product to sewer systems without previously notifying the local sewage treatment plant authority. For guidance contact your State Water Board or Regional Office of the EPA.

End Use Products Do not apply directly to water or to areas where surface water is present or to intertidal areas below the mean high water mark. Do not contaminate water when disposing of equipment wash water or rinsate.

This pesticide is toxic to aquatic organisms.

Label statements for spray drift management AVOIDING SPRAY DRIFT AT THE APPLICATION SITE IS THE RESPONSIBILITY OF THE APPLICATOR. The interaction of many equipment and weather related factors determine the potential for spray drift. The applicator is responsible for considering all these factors when making decisions. Where states have more stringent regulations, they should be observed. UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON, D. C. 20460 OFFICE OF PREVENTION, PESTICIDES, AND TOXIC SUBSTANCES Environmental Fate and Ecological Risk Assessment for the Reregistration of Maneb [[ 1,2 Ethanediylbis [ carbamodithioato]]( 2)] manganese Prepared by: Mohammed A. Ruhman, Ph. D. Ronald Parker, Ph. D. Gabe Patrick United States Environmental Protection Agency Office of Pesticide Programs Environmental Fate and Effects Division Environmental Risk Branch V 401 M Street, SW Mail Code 7507C Washington, D. C. 20460 Reviewed by: Mah Shamim, Ph. D. ii TABLE OF CONTENTS I. Executive Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 II. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 a. Use Characterization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 b. Approach to Risk Assessment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 III. Integrated Environmental Risk Characterization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 a. Overview of Environmental Risk . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 b. Key Issues of Uncertainty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 i. Environmental Fate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 ii. Ecological Effects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 c. Endangered Species Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 d. Endocrine Disruption Concerns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 IV. Environmental Fate Assessment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 a. Chemical Identity and Physicochemical Properties . . . . . . . . . . . . . . . . . . . . . . . . . 19 b. Fate Processes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 i. Aqueous Solutions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 ii. Soil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 iii. Sediment/ Water Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 iv. Bound Species, CS 2  data and Half life Determination for EBDCs . . . . . . . . 23 c. Mobility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 d. Field Dissipation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 e. Bio accumulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 V. Water Resource Assessment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 a. Surface Water Monitoring and Modeling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 b. Ground Water Monitoring and Modeling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 c. Drinking Water Assessment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 VI. Aquatic Exposure and Risk Assessment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 a. Hazard Summary ( Acute/ Chronic) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 b. Exposure and Risk Quotients . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 c. Aquatic Risk Assessment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 i. Incidents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 ii. Endocrine Disruptors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 iii Endangered Species . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 VII. Terrestrial Exposure and Risk . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 a. Hazards Summary ( Acute/ Chronic) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 iii b. Exposure Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 c. Risk Quotients . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 d. Terrestrial Risk Assessment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 i. Incidents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 ii. Endocrine Disruptors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 iii. Endangered Species . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 APPENDIX I: Notes on Fate Studies and Modeling & Additional Fate Data . . . . . . . . . . . . . . 51 a. Notes on Fate Studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 i. Aqueous medium studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 ii. Soil/ sediment studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 b. Notes on Modeling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 i. EECs for Parent maneb . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 ii. Background Information on the PRZM and EXAMS models & the Index Reservoir Scenario . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 iii. Background Information on SCIGROW . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 c. Additional Fate Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 APPENDIX II: Hoerger Kenaga Estimates & Fate v. 5.0 Model . . . . . . . . . . . . . . . . . . . . . . . 59 a. Hoerger Kenaga Estimates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 b. Fate v. 5.0 Model Terrestrial Exposure Values . . . . . . . . . . . . . . . . . . . . . . . . . . 60 c. Fate v. 5.0 Model Sample Outputs for Maneb . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 APPENDIX III: Ecological Hazards Assessment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 a. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 b. Toxicity to Terrestrial Animals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 i. Birds, Acute, Subacute and Chronic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 ii. Mammals, Acute and Chronic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66 1. Acute Oral Toxicity Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66 2. Acute Dermal and Inhalation Toxicity Testing . . . . . . . . . . . . . . . . . 66 3. Mammalian Feeding, Reproductive and Developmental Toxicity Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67 iii. Insect Acute Contact . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 iv. Insect Residual Contact . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 v. Terrestrial Field Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 c. Aquatic Organism Toxicity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 i. Toxicity to Freshwater Animals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 1. Freshwater Fish, Acute . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 2. Freshwater Fish, Chronic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 3. Freshwater Invertebrates, Acute . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71 4. Freshwater Invertebrate, Chronic . . . . . . . . . . . . . . . . . . . . . . . . . . . 72 5. Freshwater Field Studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72 ii. Toxicity to Estuarine and Marine Animals . . . . . . . . . . . . . . . . . . . . . . . . . . 72 iv 1. Estuarine and Marine Fish, Acute . . . . . . . . . . . . . . . . . . . . . . . . . . 72 2. Estuarine and Marine Fish, Chronic . . . . . . . . . . . . . . . . . . . . . . . . . 73 3. Estuarine and Marine Invertebrates, Acute . . . . . . . . . . . . . . . . . . . . 73 4. Estuarine and Marine Invertebrate, Chronic . . . . . . . . . . . . . . . . . . . 74 5. Estuarine and Marine Field Studies . . . . . . . . . . . . . . . . . . . . . . . . . 74 iii. Toxicity to Plants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74 1. Terrestrial Plants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74 2. Terrestrial Plant Field Studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75 3. Aquatic Plants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75 4. Aquatic Plant Field Studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76 APPENDIX IV: Environmental Exposure Assessment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77 a. Overview of Risk Quotients ( RQs) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77 b. Exposure and Risk to Terrestrial Animals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79 i. Birds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79 ii. Mammals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84 iii. Insects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89 c. Aquatic Organisms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89 i. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89 ii. Freshwater Fish . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90 iii. Freshwater Invertebrates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91 iv. Estuarine/ Marine Fish . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92 v. Estuarine/ Marine Invertebrates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93 d. Exposure and Risk to Non target Plants: Aquatic Plants . . . . . . . . . . . . . . . . . . . . . . 94 e. Endangered Species . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95 f. Ecological Incidents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95 APPENDIX V: US EPA Ecological Incident Information System . . . . . . . . . . . . . . . . . . . . . . 97 APPENDIX VI: EBDC Aquatic Studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99 APPENDIX VII: Maneb Revised Risk Quotients for Almonds & Turf Uses . . . . . . . . . . . . . 102 REFERENCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104 1 I. Executive Summary There are potential chronic risks to birds and mammals, acute risks to freshwater fish and estuarine/ marine animals, and acute risks to aquatic nonvascular plants. These potential risks occur for all or some of maneb's uses. Because EFED lacks data, EFED is uncertain about maneb's potential acute risk to terrestrial plants, chronic risks to freshwater invertebrates, chronic risks to estuarine/ marine animals and acute risks to aquatic vascular plants.

Based on available data, EFED expects all maneb's uses present potential chronic risks to birds and mammals. EFED relied on a referenced total foliar dissipation half life value of 3.2 days to evaluate exposure to terrestrial organisms ( Willis and McDowell, 1987). Avian chronic LOCs are exceeded for all use patterns. RQs range from a high of 265 from the turf use to a low of 0.4 from maneb's uses on collards, turnips, and mustard ( Georgia and Tennessee, only). Mammalian chronic LOCs are exceeded for all uses patterns. RQs range from a high of 71 from the turf use to a low of 0.1 from maneb's uses on collards, turnips, and mustard ( Georgia and Tennessee, only). EFED used a mallard duck reproductive study to calculate the RQs for this assessment. EFED based birds chronic reproductive effects on decreases in the number of hatchlings as percentages of eggs laid, eggs set, and live 3 week old embryos, and a decrease in the number of 14 day old survivors as a percentage of eggs.. EFED based mammal reproductive effects on a 2 generation study in rats. These mammal effects were male parental toxicity resulting in significant increase in lung weight ( both generations) and liver weight ( F1 generation) with lesions noted on these organs in the F1 generation. EFED does not calculate risk quotients to conduct risk assessments on terrestrial invertebrates. Based on the lack of acute maneb toxicity to honeybees, EFED expects a low acute risk to nontarget terrestrial insects. Due to lack of data EFED did not assess risks to terrestrial plants or fully assess risks to aquatic plants. In the aquatic environment, EFED concludes maneb will present a potential acute risk to freshwater/ estuarine/ marine fish and invertebrates as well as nonvascular aquatic plants. EFED selected representative maneb use patterns at maximum application rates and minimum intervals between applications for aquatic modeling. Maneb is used on more than 20 different crop groupings. The representative sites selected for aquatic modeling were apples, peppers, potatoes ( Maine, only) and tomatoes. The acute RQs exceeding freshwater fish acute, acute restricted use, and acute endangered species LOCs for all maneb's modeled uses range from 1.13 to 4.71. The acute freshwater invertebrates' RQs exceeding acute restricted use, and acute endangered species LOCs for all maneb's modeled uses range from 0.40 to 1.65. The acute estuarine/ marine fish RQs exceed acute restricted use, and acute endangered species LOCs for all maneb's modeled uses with RQs ranging from 0.47 to 1.1. Estuarine/ marine invertebrate acute RQs exceed acute, acute restricted use, and acute endangered LOCs for all maneb's modeled uses with RQs ranging from 15.87 to 65.97. Based on data for one surrogate species, maneb's modeled use patterns exceed acute risk LOCs for nonvascular aquatic plants with acute RQs ranging from 3.55 to 14.77. EFED did not assess chronic risks to freshwater invertebrates, estuarine/ marine fish, or estuarine/ marine invertebrates due to lack of data.

Maneb is a non systematic fungicide applied to foliage and as a seed treatment for the control of fungal diseases on numerous crops, ornamental plantings, and turf. The maximum application rates for the major crops are16.0, 16.8, 9.6, and 14.4 lbs a. i/ acre/ crop cycle for potatoes, tomatoes, lettuce, 2 In this document three important abbreviations are used: Parent maneb, maneb complex and Bound species. Parent maneb is the polymeric parent maneb present in the active ingredient. Maneb Complex is a suite of multi species residues resulting from degradation of the polymeric parent maneb. The suite includes the following: ( a) species reported to be present but not specifically identified: variable/ low molecular weight polymeric chains ( i. e polymer fragments), monomeric species, and EBDC ligand in association with other metal ions that might be present in the environment; ( b) species identified and quantified: Transient species, ETU and ETU degradates; and ( c) un identified species that bound to soil and sediment particles ( referred to as Bound species).

2 and peppers; and 18.0 and 25.6 lbs a. i/ acre/ year for sweet corn and almonds, respectively. Maneb is applied as a broadcast treatment using both air and ground equipment and has numerous seed treatment uses.

Maneb is a polymer or a highly coordinated salt complex, in which the EBDC ( ethylene bis dithio carbamate) ligand present in coordination with Mn+ 2. Foliar application of maneb cause it to reach plant/ soil surfaces directly and air/ water bodies by drift. In the air, maneb will eventually be deposited onto soil/ plant/ water bodies with minimal change. On plant surfaces, it is affected by physical washoff and abiotic hydrolytic decomposition given time and water availability. Fate of maneb reaching the soil and water/ sediment systems is mainly controlled by hydrolytic decomposition and soil/ sediment adsorption.

Parent maneb2 ( complete polymeric chains) is non persistent as it is expected to decompose rapidly ( reach < 10% of the applied within one day) by hydrolytic reactions in the main compartments of the natural environment. Initial hydrolytic decomposition of maneb appears to be a complex process and may involve its breakdown into variable/ low molecular weight polymeric chains ( i. e polymer fragments), monomeric species, EBDC ligand in association with metal ions, and degradates. The final product of hydrolytic decomposition of parent maneb in water/ soil pore water is a multi species residue hereinafter is refer to as the " maneb complex". Parent maneb is not expected to partition into the air from soil and water surfaces due to low vapor pressure and low Henry's Law constant. Low K ow values are reported for maneb, therefore the chemical will not be significantly bioconcentrated by aquatic organisms such as fish.

In contrast, Maneb Complex consists of transient species and degradates including the degradate of concern, ETU and its degradates. In aqueous media, transient species are short lived while ETU is persistent; unless it is subjected to rapid degradation by microbial action and/ or indirect photolysis. In soils/ sediments, a significant portion of the complex partitions into the soil/ sediment particles ( reached 70 to 90% of the applied parent within one week). In these systems, species identified in the liquid/ extractable phase were similar in identity ( differ in concentration) to those identified in aqueous media. Species bound to soil/ sediment were poorly characterized and claimed, by the registrant, to be dominated by ethylene diamine ( EDA). In the absence of experimental proof of EDA or complete characterization of these bound species, EFED is concerned about the bound species as it is persistent and could contain precursors for ETU.

Conversion of parent maneb into its complex by hydrolytic decomposition appears to be eminent and 3 rapid even at concentrations higher than those expected to reach the environment by application. Therefore, parent applied is expected to be found as residue, the maneb complex, in most natural environments. Maneb complex species in association with soil/ sediment, appear to bio degrade at a very slow rate producing maneb degradates including ETU. Residue species left in the liquid phase may continue to be affected by hydrolytic decomposition along with microbial activity ( if present) producing degradates including ETU.

Submitted fate data are adequate to characterize the environmental fate and transport of the " multi species residue" of maneb as a whole. Based on submitted fate data, most of the constituents of this complex are immobile and highly persistent in the environment, with aerobic soil metabolism being the major route of its slow dissipation. As maneb and its complex dissipate in aquatic and soil/ terrestrial environments, degradation products are produced including ETU.

EFED relied on a referenced total foliar dissipation half life value of 3.2 days ( Willis and McDowell, 1987) to evaluate exposure to terrestrial organisms. The stressor in this case is parent maneb although hydrolytic reactions on foliage may result in dominance of maneb complex over the parent. Terrestrial exposure was quantified as Estimated Environmental Concentrations ( EECs) by modeling for the maximum application rates. For the aquatic environment, the main stressor is the maneb complex and its EECs were estimated using tier 2 PRZM/ EXAMS modeling for the various crop scenarios. Drinking water assessment was performed only for ETU ( refer to the accompanied ETU document); the degradate of concern present in the complex.

EFED is uncertain about maneb's risk to non target terrestrial plants. EFED needs testing performed at maneb's maximum rate of application in the environment to evaluate this risk. EFED expects the potential chronic risks to birds and mammals from maneb's uses. RQs exceed chronic LOCs for all maneb's uses for both birds and mammals. EFED expects maneb's uses to present a low acute risk to birds, mammals, and nontarget insects because maneb is practically nontoxic to these organisms and historically there has been no incident data documenting adverse effects to these organisms.

In the aquatic environment, maneb complex presents a potential acute risk to freshwater fish, freshwater invertebrates, estuarine/ marine fish, estuarine/ marine invertebrate, and nonvascular aquatic plants with LOCs exceeded. The chronic maneb complex risk to freshwater fish is low with no LOCs exceeded. The data filed and reviewed to characterize maneb complexes' potential acute risk to aquatic animals and aquatic nonvascular plants is satisfactory. EFED has no data to evaluate maneb complexes' chronic risks to freshwater invertebrates or estuarine/ marine organisms and is seeking data to evaluate these risks. EFED has not received studies to evaluate the risk of the maneb complex to vascular aquatic plants and needs studies presented to evaluate this risk. EFED needs testing performed on more aquatic nonvascular plant taxa to evaluate fully the risk to nonvascular aquatic plants. 4 II. Introduction Maneb is a broad spectrum fungicide belonging to a chemical class of polymeric dithiocarbamate and a group classified as ethylene bisdithiocarbamate ( EBDC) fungicides. Maneb is classified as a nonsystemic contact fungicide with preventive activity. Maneb is marketed by several companies under varied names and formulations. Formulation types include dusts, water dispersible granules ( dry flowables), emulsifiable concentrates, flowable concentrates, wettable powders, and liquid ready to use.

a. Use Characterization Maneb is applied to foliage and as seed protectant for the control of fungal diseases on numerous crops, ornamental plantings ( trees, herbaceous plants, non flowering plants, woody shrubs and vines), and turf ( commercial/ industrial, golf course, sod farm, recreational, and residential). It is applied as a broadcast treatment using both air and ground equipment and has numerous seed treatment uses. There are 36 products registered containing maneb: 2 manufacturing use product, 33 end use products and 1 special local need ( 24 c) registration ( OPP REFs data August, 2000). There are both multiple and single active ingredient products. A synopsis of the use pattern for this chemical is provided below in Table II 1.

Table II 1. Maneb use patterns.

Crop Maximum Application Rate Number of Applications Minimum Application Interval ( days) Per Treatment In Total Almonds 6.4 lbs a. i/ acre 25.6 lbs a. i/ acre/ crop cycle 4 7 Apples 4.8 lbs a. i/ acre 19.2 lbs a. i/ acre/ year 4 7 Bananas 2.4 lbs a. i/ acre 24 lbs a. i/ acre/ crop cycle 10 14 Barley, Rice, Rye, Sorghum, Soybean & Wheat 0.2 lbs a. i/ 100 lbs seed ( Seed treatment) 1 NA Beans ( dried) 1.6 lbs a. i/ acre 9.6 lbs a. i/ acre/ crop cycle 6 5 Broccoli, Brussel Sprouts, Cabbage a 1.6 lbs a. i/ acre 9.6 lbs a. i/ acre/ crop cycle 6 7 Collards & Turnip ( GA & TN only) 1.2 lbs a. i/ acre 3.6 lbs a. i/ acre/ crop cycle 3 14 Corn ( field), Cotton & Oats 0.3 lbs a. i/ 100 lbs seed ( Seed treatment) 1 NA Corn ( pop & sweet), East of the Mississippi River b 1.2 lbs a. i/ acre 18.0 lbs a. i/ acre/ year 15 3 Corn ( pop & sweet), West of the Mississippi River c 1.2 lbs a. i/ acre 6.0 lbs a. i/ acre/ year 5 3 Cranberry 4.8 lbs a. i/ acre 14.4 lbs a. i/ acre/ year 3 7 Cucumber, Melons, Pumpkin & Squash 1.6 lbs a. i/ acre 12.8 lbs a. i/ acre/ crop cycle 8 7 Eggplant & Sugar Beets 1.6 lbs a. i/ acre 11.2 lbs a. i/ acre/ crop cycle 7 7 Fig 2.4 lbs a. i/ acre 2.4 lbs a. i/ acre/ year 1 NA Flax 0.4 lbs a. i/ 100 lbs seed ( Seed treatment) 1 NA Grapes ( East of the Rocky Mountains) 3.2 lbs a. i/ acre 19.2 lbs a. i/ acre/ crop cycle 6 7 Grapes ( West of the Rocky Mountains) 2.0 lbs a. i/ acre 6.0 lbs a. i/ acre/ crop cycle 3 7 Crop Maximum Application Rate Number of Applications Minimum Application Interval ( days) Per Treatment In Total 5 Kale 1.6 lbs a. i/ acre 3.2 lbs a. i/ cutting 2/ cutting 7 Mustard ( GA and TN only) 1.2 lbs a. i/ acre 2.4 lbs a. i/ acre/ crop cycle 2 14 Onion & Garlic 2.4 lbs a. i/ acre 24.0 lbs a. i/ acre/ crop cycle 10 7 Onion ( green) & Tomatoes ( East of the Mississippi R) 2.4 lbs a. i/ acre 16.8 lbs a. i/ acre/ crop cycle 7 7 Papaya 2.0 lbs a. i./ acre 28.0 lbs a. i/ acre/ crop cycle 14 14 Peanuts 0.8 lbs a. i/ 100 lbs seed ( Seed treatment) 1 NA Pepper ( East of the Mississippi River) 2.4 lbs a. i/ acre 14.4 lbs a. i/ acre/ crop cycle 6 7 Pepper ( West of the Mississippi River) 1.6 lbs a. i/ acre 9.6 lbs a. i/ acre/ crop cycle 6 7 Potatoes ( Maine only) 1.6 lbs a. i/ acre 16.0 lbs a. i/ acre/ crop cycle 10 5 Potatoes 1.6 lbs a. i/ acre 11.2 lbs a. i/ acre/ crop cycle 7 5 Safflower 0.1 lbs a. i/ 100 lbs seed ( Seed treatment) 1 NA Sunflower 0.4 lbs a. i/ 100 lbs seed ( Seed treatment) 1 NA Tomatoes ( West of the Mississippi River) 1.6 lbs a. i/ acre 6.4 lbs a. i/ acre/ crop cycle 4 7 Ornamentals d 1.2 lbs a. i/ 100 gal Not specified 7 Turf e 17.4 lbs a. i/ acre Not specified 7 NA= Not applicable; a= including Cauliflower, Endive, Kohlrabi & Lettuce b= including AR & LA; c= excluding AR & LA; d= Trees, Herbaceous plants, Nonflowering plants & Woody shrubs and Vines; e= Residential, Commercial/ Industrial, Gulf Course, Sod farm & Recreational.

Figure II 1, below, shows the general use areas for maneb across the US ( USGS data 1990  1993 and 1995).

EFED utilized OPP's Label Use Information System ( LUIS) for maneb labels registered as of 10/ 31/ 2001, OPP's Reference Files System ( REFS), the Maneb Use Closure Memo, and spot 6 checking of currently registered maneb labels to determine what maneb use patterns posed the most significant risk to the environment. EPA use data ( BEAD's Quantitative Usage Analysis for Maneb dated November 1, 2002) for the period 1992 through 2001 shows that 41% of the lettuce, 34% of the bell peppers, 34% of the sweet peppers, 39% of the pumpkins and 25% of the cabbage grown in the US are treated with maneb.

b. Approach to Risk Assessment Maneb is a polymer or a highly coordinated salt complex, with unique properties. It is expected to be introduced to the environment at application rates resulting in soil concentration levels of < 10 ppm and much lower concentrations in water bodies. When parent maneb is introduced into water bodies, by drift, at the expected low concentrations, it decomposes rapidly into the maneb complex including the degradate of concern ETU. In contrast, when parent maneb is introduced into soil or water/ sediment systems, similar rapid decomposition occurs with most of the constituents of maneb complex partitioning into soil/ sediment particles. Parent maneb terrestrial EECs were calculated using a spread sheet based on the slope of the 1st order hydrolysis half lives. However, Parameters determined from environmental fate studies and information on physicochemical properties were used in estimating aquatic EECs of the resultant maneb complex. The major degradate of concern, ETU, was considered in the fate and exposure assessment in a separate RED document with consideration to all EBDCs ( metiram, mancozeb and maneb). Normally, EFED would evaluate the risk( s) posed by a chemical's degradate( s) of concern within the risk assessment document for the chemical. However, since ethylene thiourea ( ETU) is a common degradate for all the EBDCs ( mancozeb, maneb and metiram) it was decided to address the environmental risk posed by ETU in a separate document and avoid repetitive references in the risk assessments for each of the EBDC chemicals. This approach to risk assessment was necessary because maneb decomposes very quickly, by hydrolytic reactions in water, into " multi species maneb complex". Therefore, hydrolysis is the dominant factor in controlling parent maneb concentration and calculated hydrolysis half lives are the parameter of choice for determining its fate. Measured parameters in fate studies were actually for maneb complex and were used to estimate the EECs for that complex.

To evaluate the potential risk to aquatic and terrestrial organisms from the use of maneb, risk quotients ( RQs) are calculated from the ratio of estimated environmental concentrations ( EECs) to ecotoxicity values ( see Appendix IV). EECs are based on the maximum application rate of maneb for the use patterns currently registered. These RQs are then compared to the levels of concern ( LOC) ( see Appendix IV for these values) criteria used by EFED for determining potential risk to non target organisms and the subsequent need for possible regulatory action.

When possible, sites having similar use patterns ( application rates, timings, methods, number of applications, and intervals between applications) were grouped to evaluate the risks. Although maneb has numerous seed treatment uses ( see Table 1, above) the RQs from these seed treatment uses were not calculated in this RED. Numerous seed treatment uses of mancozeb were evaluated in the mancozeb RED and no LOCs were exceeded. The avian acute LD 50 of maneb ( Bobwhite quail LD50 > 2,150 mg/ kg) is practically nontoxic to birds and was greater than the avian acute LD50 for 7 mancozeb ( English sparrow LD50 .1,500 mg/ kg). Since maneb is less toxic to birds on an acute basis than mancozeb and the exposure ( rates of application) from these seed treatment uses are similar for maneb and mancozeb, EFED expects the acute risks to birds from eating maneb treated seeds is low. Since maneb is practically nontoxic to birds on an acute dietary basis ( mallard duck LC50 > 5,000 ppm and bobwhite quail LC50 > 10,000 ppm) the acute dietary risks to birds eating food items exposed to spray applications of maneb is also expected to be low. Because of this EFED did not calculate RQs for acute dietary exposure. It should also be noted that maneb assessments for chronic risk to plants, acute/ chronic risks to non target insects, or chronic risk from granular/ bait formulations to birds and mammals have not been evaluated because scenarios for evaluating these risks have not been developed.

EFED evaluated terrestrial exposure using EECs produced from the FATE version 5.0 model that calculates the decay of a chemical applied to foliar surfaces for single or multiple applications. The model assumes initial concentrations on plant surfaces based on Kenaga predicted maximum and mean residues as modified by Fletcher et al. ( 1994) and assumes 1st order dissipation. Kenaga estimates and an explanation of the model with sample output are presented in Appendix II. EFED used a 3.2 day half life as the total foliar dissipation half life for maneb. EFED selected this half life from the highest value provided in the half life listing of Willis and McDowell, 1987 for maneb. This half life value is based on total foliar residues not dislodgeable foliar residues and was determined in a study by Rhodes, 1977 performed on tomatoes. Willis and McDowell, 1987 also showed a maneb total foliar residue half life of 2.8 days for snap beans ( Rhodes, 1977). These studies, conducted in Florida, received 16.5 mm ( 0.6 inch) of rainfall during the measurement period. EFED uses the halflife listing values provided in Willis and McDowell, 1987 for modeling purposes to estimate total foliar residues half lives.

EFED needs total foliar dissipation residue or total foliar residue ( TFR) half life information as a modeling input value to estimate terrestrial wildlife exposure. TFR is the total pesticide residue contained both on the surface and absorbed into treated leaves. EFED has no requirements for submitting such data now and relies on available half life data chiefly from Willis and McDowell ( 1987). Since maneb TFR half life information was limited from Willis and McDowell ( 1987), EFED reviewed half life information from HED. EFED was initially drawn to explore HED's information because TFR half life information was unavailable in Willis and McDowell ( 1987) for metiram, mancozeb, and ETU. HED receives dislodgeable foliar residue ( DFR) dissipation half life data ( guideline 875.2100) to estimate exposures to individuals from working in an environment that has been treated with a pesticide ( also referred to as reentry exposure). DFR is the pesticide residue on treated leaves' surface. For maneb and mancozeb HED ( Dole and Dawson, 2003 and 2003b) provided the following ( Table II 2) with MRID Nos. The Mancozeb Task Force provided the Newsome study through a literature submission ( Ollinger, 2005).

Table II 2. Summary of Maneb DFR and TFR Data for Crops MRID ( Year) CROP ( Location) Application Method lb ai/ Acre * Number of Applications DFR Half Life TFR Half Life 420449 04( 90) CA Grapes Airblast 3.2 * 3 ( 30 day intervals) 32.8 ( day) Not available Table II 2. Summary of Maneb DFR and TFR Data for Crops MRID ( Year) CROP ( Location) Application Method lb ai/ Acre * Number of Applications DFR Half Life TFR Half Life 8 415117 01( 88) 451946 01( 99) 451946 01( 99) NY Apples NY Apples WA Apples Airblast Airblast Airblast 8.0 * 10 ( 7 day intervals) 4.8 * 2 ( 7 day intervals) 4.8 * 2 ( 7 day intervals) 17.8 ( days) 7.2 ( days) 23.6 ( days) Not available Not available Not available 419615 01( 90) 420449 02( 91) 420449 03( 91) Newsome, 1976 Rhodes, 1977 CA Tomatoes FL Site 1 Tomatoes FL Site 2 Tomatoes Canada Tomatoes FL Tomatoes Ground boom Ground boom Ground boom Groundboom not available 2.4 * 3 ( 10 day intervals) 2.4 * 9 ( 7 day intervals) 1.9 * 9 ( 7 day intervals) 2.4 * 7 ( 7 days) not available 7.5 ( days) 19.1 ( days) 9.9 ( days) Not available not available Not available Not available Not available 7.31,2 3.23 Rhodes, 1977 FL Snap beans not available not available not available 2.83 Mancozeb Study With Both DFR and TFR Data 411339 01( 86) 411339 01( 86) CA Grapes ( Madera) CA Grapes ( Fresno) Airblast Airblast 3.2 * 3 3.2 * 3 15.2 ( days) 9.6 ( days) 14.9 ( days) 9.3 ( days)

Note 1  Half life values calculated by EFED from the data provided in the study. Note 2  TFR was from homogenized samples of the tomato fruit, only, submitted by the Mancozeb Task Force ( Ollinger, 2005) Note 3  Source: Willis and McDowell ( 1987)

There were eight mancozeb, one metiram and six maneb DFR studies presented. Based on a review of all the EBDC DFR studies filed, EFED would expect a variation in DFR half life values. This variation would be because of differences in application methods such as application rates, differences in crops such as morphology, and regional differences such as weather. HED's review showed the climate effect was a greater effect than the effect of crop morphology or application method. " The EBDC and ETU half lives were typically twice as long in the west as in the east..."( Dole and Dawson, 2003a).

Most DFR studies used the standard dislodging technique. The 1986 mancozeb study on grapes at Madera and Fresno, California ( MRID 411339 01) also used the total extraction method ( T. Dole, per. com., 9/ 13/ 01). Based on this mancozeb study EFED expects the EBDC's DFR half life would be comparable to the EBDC's TFR half life since the 1986 mancozeb study on grapes at Madera and Fresno, California showed similar DFR and TFR half lives. EFED might not expect such a likeness if the pesticide showed systemic activity but none of the EBDCs are systemic.

Maneb's DFR half lives range from 7.2 to 32.8 days based on the studies available from HED. Willis and McDowell ( 1987) shows 2 TFR maneb half life values for 2 crops ( that is, snap beans and tomatoes) . Given this limited information EFED feels it would be reasonable to use a 33 day TFR half life for maneb as a conservative upper bound estimate in this screening level assessment. EFED routinely uses the upper limit of TFR half life values ( that is, 35 days) provided in Willis and McDowell ( 1987) to perform screening level risk assessments. EFED expects maneb's DFR half life would be comparable to the maneb's TFR half life for most crops. The highest DFR value shown in Table II 2 is 32.8 days. It is reasonable to use this high end estimate ( that is, 33 days) in this screening level assessment. It is reasonable because it is the highest, most conservative, half life value and the data available is limited. Maneb is used on more than 20 crop grouping ( see Table II 1) or more than 40 crops. The maneb DFR studies in Table II 2 provide half life information on 4 crops ( that is, grapes, apples, tomatoes, and turf) and TFR half life information on 3 crops ( that is, grapes, 9 snap beans, and tomatoes).

EFED didn't find half life values for metiram and mancozeb in Willis and McDowell, 1987. Because of this, EFED consulted HED for DFR half life information. EFED wanted to decide if the high end half life value ( 35 days) in Willis and McDowell, 1987 was a reasonable foliar half life estimate for metiram and mancozeb. The metiram DFR data from HED was limited. One study ( MRID No. 41339901, 1988) on California apples showed a 31.4 day DFR half life. Given this limited data, EFED used a 35 day TFR half life value for metiram's terrestrial EEC modeling. The mancozeb DFR and TFR half life data were more robust. HED provided 15 DFR half life values for 4 crops and 2 TFR half life values for 1 crop. The high end value for these mancozeb DFR and TFR half lives was 35.4 days from a DFR half life study done on California grapes ( MRID No. 41836901, 1991). As a result, EFED used a 35 day TFR half life value for mancozeb's terrestrial EEC modeling.

EFED used 35 day TFR half life values for mancozeb's and metiram's terrestrial EEC modeling as high end, conservative half life values. EFED used a 3.2 day TFR half life value for maneb chiefly because this value was listed in Willis and McDowell, 1987. EFED uses Willis and McDowell, 1987 as a standard source of TFR values for risk assessments. However, in retrospect, EFED should have included a 33 day TFR half life for maneb's terrestrial EEC modeling as a conservative upper bound estimate in this screening level assessment. EFED intends to include these extra calculations in the next revision of this RED. These new calculations for terrestrial EEC modeling will also require revisions to the RQ calculations. The RQs will increase because of these new calculations, using a 33 day TFR half life value, because the exposure to wildlife will be greater. However, maneb's potential chronic risk to birds and mammals will remain unchanged. All maneb's uses exceed bird and mammal chronic LOCs using the 3.2 day TFR half life value.

EFED assumed 3 applications of maneb to ornamentals and turf per crop cycle since the labeling did not show the number of applications that could be made. If the number of applications applied to ornamental and turf sites is greater than 3 applications then the risk to nontarget organisms would increase. The assumption of 100 gallons of finished spray per acre treated was also an assumption made for maneb applications to ornamentals. If lower finished spray rates are used then the pounds of maneb applied per acre are even greater than assumed which would increase the risk to nontarget organisms.

Monitoring data from field locations are not available for maneb. Because of this, EFED based maneb aquatic EECs on screening models. EFED modeled maneb's surface water concentrations using the Pesticide Root Zone Model version 3.1.2 beta ( Carsel et al., 1997) and Exposure Analysis Modeling System version 2.98.04 ( Burns, 1997) ( PRZM/ EXAMS) for Tier II estimates.

EFED looked specifically at the impact of EBDC usage on turf. Mancozeb and Maneb both include turf on their labels, but the actual usage is small relative to other crops. Use of fungicides is generally minimal on sod farms with mancozeb applied to 2600 acres ( about 4 square miles) or about 0.9 percent of all sod grown in the United States. The average number of fungicide applications is 1.9 nationally with a maximum use rate of about 15 lbs a. i/ acre applied in situations when either severe pest pressure conditions exist, or curative applications are utilized. Typical application rates are 10 lower. Additionally, the non systematic EBDCs serve as a rotational partner for the other systemic fungicides used in the pest management program. Therefore, risk associated with turf use pattern was not assessed for aquatic environments at this screening level risk assessment.

Conclusions based on this approach to the screening level risk assessment are summarized in Figure II 2. 11 Figure II 2. Summary of the screening level risk assessment for maneb in terrestrial and aquatic systems. 12 III. Integrated Environmental Risk Characterization a. Overview of Environmental Risk Based on available data, maneb use is expected to pose potential chronic risks to terrestrial birds and mammals. In the aquatic environment, it is concluded that maneb will present potential acute risk to freshwater/ estuarine/ marine fish and invertebrates as well as nonvascular aquatic plants. These potential risks occur for all or some of maneb's uses. Because EFED lacks data, EFED is uncertain about maneb's potential acute risk to terrestrial plants, chronic risks to freshwater invertebrates, chronic risks to estuarine/ marine animals and acute risks to aquatic vascular plants.

Parent maneb is insoluble in water but is expected to decompose rather quickly, by hydrolytic reactions, into a multi species residue ( maneb complex) consisting of transient species and degradates including the degradate of concern ETU. In dry conditions and in soils with very low water holding capacity parent maneb decomposition is slow. Maneb has low octanol/ water partition coefficients ( K ow ) suggesting that it would not be significantly bio concentrated by aquatic organisms. Furthermore, maneb has a very low vapor pressure, thus indicating that volatilization is not an important dissipation pathway. Due to rapid hydrolytic decomposition, parent maneb is expected to exist in the natural environment for a short duration (< 1 day). This rate is largely dependent on moisture availability and therefore in dry conditions and in soils with very low water holding capacity parent maneb will persist.

Most of the species present in the maneb complex are expected to partition into the soil/ sediment particles; with varied strength of bonding. These soil associated materials are not largely affected by abiotic degradation but are susceptible to very slow bio degradation further producing degradates, that might include ETU, at low concentrations and very slow rate.

Based on available data, EFED expects all maneb's uses to present potential chronic risks to birds and mammals. EFED relied on a referenced total foliar dissipation half life value of 3.2 days to evaluate exposure to terrestrial organisms ( Willis and McDowell, 1987). Maneb's DFR half lives range from 7.2 to 32.8 days based on the studies available from HED. However, all maneb's uses exceeded bird and mammal chronic LOCs using the 3.2 day TFR half life value. Avian chronic LOCs are exceeded for all uses patterns. RQs range from a high of 265 from the turf use to a low of 0.4 from maneb's uses on collards, turnips, and mustard ( Georgia and Tennessee, only). Mammalian chronic LOCs are exceeded for all uses patterns. RQs range from a high of 71 from the turf use to a low of 0.1 from maneb's uses on collards, turnips, and mustard ( Georgia and Tennessee, only). EFED does not calculate risk quotients to conduct risk assessments on terrestrial invertebrates. Based on the lack of acute maneb toxicity to honeybees, EFED expects a low acute risk to nontarget terrestrial insects. Due to lack of data EFED did not assess risks to terrestrial plants or fully assess risks to aquatic plants. EFED is uncertain about maneb's risk to non target terrestrial plants and needs testing performed at maneb's maximum rate of application in the environment. In the aquatic environment, EFED concludes maneb will present potential acute risk to freshwater/ estuarine/ marine fish and invertebrates as well as nonvascular aquatic plants. EFED selected representative maneb use patterns at maximum application rates and minimum intervals 3 Marshall, W. D. 1977. J. Agri. Food Chem. 25 ( 2), 357 361 13 between applications for aquatic modeling. Maneb is used on more than 20 different crop groupings. The representative sites selected for aquatic modeling were apples, peppers, potatoes ( Maine, only) and tomatoes. The acute RQs exceeding freshwater fish acute, acute restricted use, and acute endangered species LOCs for all maneb's modeled uses range from 1.13 to 4.71. The acute freshwater invertebrates' RQs exceeding acute restricted use, and acute endangered species LOCs for all maneb's modeled uses range from 0.40 to 1.65. The acute estuarine/ marine fish RQs exceed acute restricted use, and acute endangered species LOCs for all maneb's modeled uses with RQs ranging from 0.47 to 1.1. Estuarine/ marine invertebrate acute RQs exceed acute, acute restricted use, and acute endangered LOCs for all maneb's modeled uses with RQs ranging from 15.87 to 65.97. Based on data for one surrogate species, maneb's modeled use patterns exceed acute risk LOCs for nonvascular aquatic plants with acute RQs ranging from 3.55 to 14.77. EFED has not received studies to evaluate the risk of maneb complex to vascular aquatic plants and needs testing performed on more aquatic nonvascular plants to evaluate fully the risk to aquatic plants. EFED did not assess chronic risks to freshwater invertebrates, estuarine/ marine fish, or estuarine/ marine invertebrates due to lack of data.

b. Key Issues of Uncertainty i. Environmental Fate EECs for parent maneb were estimated for water bodies using hydrolysis half lives. The same water hydrolysis half lives were used for soils assuming sufficient moisture is available in soil pores for hydrolysis to occur at the same rate. Uncertainty exists on whether half lives used are applicable because of uncertainty related to soil moisture availability as soil moisture level is expected to impact resultant EECs. Lower EECs are expected in irrigated and/ or rain fed soils with high water holding capacity ( WHC) and higher EECs are expected in low WHC soils under dry conditions. Giving the fact that maneb is applied to growing crops, moisture is expected to be available for parent to hydrolyze at an adjusted rate near or just below that determined from aqueous hydrolysis half lives. Other factors that are known to affect hydrolytic stability of maneb include: particle size; molecular weight distribution; aqueous media pH and concentrations of O 2 3; and metal ions that are capable of exchanging structural Mn. However, the very low hydrolytic stability of parent maneb render consideration of such factors un important.

EECs for maneb complex were estimated using the physicochemical properties and hydrolysis halflives of parent maneb in addition to aerobic soil metabolism half lives and sorption coefficients which were assigned to this complex rather than the parent. In all aerobic soil studies two separate sets of experiments/ determinations were conducted: the first was to obtain data for calculating half lives using the CS 2  method to quantify the parent while the second was to characterize the degradation process. EFED believes that half lives calculated from the first set of experiments/ determinations represent hydrolytic decomposition of parent maneb rather than bio degradation. Rapid degradation of parent maneb produces a complex, the maneb complex, which appears to be affected by slow 14 degradation as indicated by production of CO 2 . Part of this complex may contain precursor( s) for the degradate of concern, ETU. Therefore, EFED used the second set of experiments/ determinations ( radioactivity data) for calculating half lives and assigned it to the maneb complex. Uncertainty exists in these complex half lives as they are affected by the validity of the assumption that the only bio degradation of the complex was represented by evolved CO 2 . Data obtained on degradates were not used as it were affected by impurities in the test materials, hydrolytic reactions and possible artificial degradation during extraction.

In this RED, aerobic soil half lives calculated from the CS 2  method are considered to represent hydrolysis of parent maneb into its complex as modified by soil conditions ( i. e. moisture content, pH and O 2 concentration). In contrast, half lives calculated from evolved CO 2 are considered to represent bio degradation of maneb complex left in the soil which appears to occur in parallel with hydrolytic decomposition of the parent. Likewise, calculated adsorption/ desorption characteristics ( K d and K oc ) are thought to represent maneb complex as it were approximated from column leaching; with no 1/ n value to indicate the degree of non linearity for the Freundlich constant.

In the degradation process for maneb Mn ions/ salts are expected to dissipate into the environment. No data were presented to evaluate the risk that might be associated with this release and therefore, uncertainty exists in this aspect of risk assessment.

Complete characterization of the fate of maneb complex requires more information on the various species that constitute this complex including the soil/ sediment bound species. Information needed are for each of these constituents and includes: their physicochemical properties and the nature of their association with soil/ sediment particles.

Additional information is presented in the Appendix ( Table I B, Appendix I) detailing major problems in maneb fate studies which adds a degree of uncertainty for estimated fate parameters for parent maneb and maneb complex, resultant EECs, and surface and groundwater modeling results.

ii. Ecological Effects How does EFED expect maneb to act in the environment after it is applied? Maneb is applied to over 20 different crop groupings, with ornamental and turf uses ( see Table II 1, p. 6) to control plant diseases. Maneb has broad uses in the US and because of this EFED expects maneb to come in contact with non target organisms across many taxa. EFED presumes applications of the maneb will occur when there is heavy plant disease pressure. Heavy disease pressure to plants results when there is high moisture from rains. These rains promote conditions for the growth and propagation of fungal species. EFED expects maneb applications will result in degradation of maneb to maneb complex including ETU on plant surfaces. EFED figures the hydrolysis of the maneb will be variable but rather fast, that is, about 1 day. Except for applications to dry soils in dry environments, EFED 4 Dry conditions is one circumstance that may explain the high end (> 30 days) foliar dissipation half life values for the EBDCs in general. EFED expects differences in application methods such as application rates, differences crops such as morphology, and regional differences such as weather also affect the foliar dissipation. Another reason that may cause longer foliar dissipation half lives is sample analysis. Measurements quantifying the foliar dissipation half life routinely use measurements of the evolved CS2 in the headspace of a sealed vial. Such measurements quantify the sulfur from both the parent EBDC and the EBDC complex in the sample. This means the EBDC's foliar dissipation half lives result from the presence over time of both the parent EBDC and the EBDC complex.

15 expects a rapid change of maneb into maneb complex, including ETU. 4 What effect does EFED expect maneb to have on non target terrestrial species? From a short term or acute exposure EFED expects maneb is a low risk to mammals and birds. This expectation is supported by toxicological studies and the lack of incident data. There are no incidents for maneb listed in the Ecological Incident Information System ( EIIS) database dealing with adverse effects to terrestrial non target organisms. EFED expects maneb's long term or chronic effects on birds and mammals to be a potential concern. This belief is supported by toxicological studies. . EFED expects chronic problems that affect wildlife from the use of maneb would be largely unnoticed in the field and thus EFED would not expect incident reports, from adverse chronic exposure. Maneb's uses exceeds chronic LOCs for terrestrial animals ( birds and mammals) for all maneb use patterns for all food categories in birds and for all food categories in mammals except for some seed categories. These exceedances occur on all terrestrial bird and mammal food items ( that is, short grass, tall grass, broadleaf forage, insects, fruits, pods, and seeds). These chronic exceedances extend throughout the application periods for all uses ranging from 16 days for figs to 197 days for papayas ( see Section VII, Terrestrial Risk Assessment, subsection d. Terrestrial Risk Assessment). In other words, there are potential reproductive risks to birds and mammals from the first application through the last application and beyond for all maneb's uses.

EFED used maneb's use on potatoes as an example ( see Section VII, Terrestrial Risk Assessment, subsection d. Terrestrial Risk Assessment). Currently in Maine, up to 10 applications of maneb are allowed to be applied to potatoes every 5 days during the growing season. Pheasant, partridge, pigeon, dove, duck, geese, songbirds, antelope, and cottontail rabbits feed in potato fields. These animals feed on insects, vegetation in the treated area, or on the potato plants throughout the potato growing season ( Gusey and Maturdo, 1972) which lasts 90 140 days ( depending on the potato variety) from late Spring to early Fall. For birds feeding on short grass this potential chronic risk begins on Day1 and continues through Day 46 for a total exposure risk period of 46 days. For mammals, this same potential chronic risk from feeding on short grass also begins on Day1 and continues through Day 40 for a total potential chronic exposure risk period of 40 days ( see Section VII, Terrestrial Risk Assessment, subsection d. Terrestrial Risk Assessment, Figure VII 5). For about 31 days after the first application to potatoes, there would be potential reproductive risks to birds and mammals feeding on short grass, broadleaf or forage plants, tall grass, and small insects. EFED used a mallard duck reproductive study to calculate the RQs for this assessment. EFED based birds chronic reproductive effects on decreases in the number of hatchlings as percentages of eggs laid, eggs set, and live 3 week old embryos, and a decrease in the number of 14 day old survivors as a percentage of eggs.. EFED based mammal reproductive effects on a 2 generation study in rats. 5 Based on green algae, ( Pseudokirchneriella subcapitata) testing.

6 The highest ETU RQ is 0.00014 ( see EFED's ETU chapter).

16 These mammal effects were male parental toxicity resulting in significant increase in lung weight ( both generations) and liver weight ( F1 generation) with lesions noted on these organs in the F1 generation.

Maneb is practically nontoxic to the honeybee from acute contact exposure. EFED does not perform risk quotient assessments for terrestrial insects. Based on the lack of acute maneb toxicity to honeybees, EFED expects a low acute risk to non target terrestrial insects. EFED is uncertain about maneb's risk to non target terrestrial plants and needs testing performed at maneb's maximum rate of application in the environment.

What effect does EFED expect maneb to have on non target aquatic species? EFED expects maneb to reach aquatic environments through drift and runoff since maneb is not labeled for direct application to aquatic environments. Maneb's solubility was reported to range from range 6 to 200 ppm. EFED expects maneb to decompose rather quickly, by hydrolytic reactions, into a multispecies residue ( maneb complex) consisting of transient species and degradates including the degradate of concern ETU. Once maneb reaches the aquatic environment EFED believes the maneb complex will be the portion of maneb that is biologically available to aquatic organisms. EFED expects most of the transient species present in the maneb complex to partition into the sediment particles with varied strength of bonding. Over time ETU is an important transformation product of the maneb complex. In aqueous media, transient species do not last long while ETU is persistent; unless it is subjected to rapid degradation by microbial and/ or indirect photolysis.

Based on laboratory studies and modeled EECs, calculated RQs show that maneb complex is an acute risk to freshwater fish, freshwater invertebrates, estuarine/ marine fish, estuarine/ marine invertebrate, and nonvascular aquatic plants. EFED estimated the highest maneb complex aquatic EEC expected from drift and runoff would be 197.9 ppb. Based on this residue level and individual laboratory studies EFED estimated the likelihood of adverse maneb complex effects to individual organisms across taxa. These chance estimates show there is high likelihood ( that is, 57 to 100%) of potential adverse acute effects to individual freshwater and estuarine/ marine aquatic organisms from maneb complex ( see section VI). Aquatic Exposure and Risk Assessment, subsection c. Aquatic Risk Assessment). EFED has no data to evaluate the chronic effects to freshwater invertebrates or estuarine/ marine organisms. No chronic LOCs are exceeded for freshwater fish from maneb's uses. The study used to calculate the freshwater fish chronic RQs for this assessment are based on the following chronic effects: decreased hatchability; fish survival; and length of fry.

In the aquatic media, ETU is expected to be an important transformation product of all the EBDCs and can persist unless it is subjected to rapid degradation by microbial and/ or indirect photolysis. The ETU acute RQs for nonvascular aquatic plants5, freshwater fish and freshwater invertebrates were well below6 the lowest LOC ( endangered species LOC = 0.05) for aquatic organisms. EFED does not know how acutely toxic ETU is to estuarine/ marine fish or invertebrates because no data has been 17 reviewed for evaluating this hazard. This means the maneb complex, other than ETU, is responsible for the acute toxicity to freshwater fish, freshwater invertebrates, and nonvascular aquatic plants. EFED expects the acute toxicity to freshwater fish, freshwater invertebrates, estuarine/ marine fish and nonvascular aquatic plants, from exposure to the maneb complex, will not last long. The acute fish studies have a duration of 96 hours, while the acute invertebrate studies last 48 hours and the nonvascular aquatic plant studies are 120 hours in duration. Acceptable aquatic half life data is unavailable for most products of the maneb complex. EFED expects maneb to hydrolyze quickly ( that is, within hours) to its residues. Based on this information, EFED expects the maneb complexes' acute toxicity to these aquatic organisms will last for 120 hours but suspects this toxicity will rapidly decline after this time period as these residues degrade to ETU. However, EFED expects there will still be enough maneb complex to present an acute risk to estuarine/ marine invertebrates. EFED expects the acute risk to estuarine/ marine invertebrates will persist because maneb complexes are very highly toxic to these organisms ( mysid shrimp EC 50 = 3 ppb). Modeled maneb complex EECs for selected sites range from 2.1 to 9.2 ppb 21 days after maneb applications ( see section V. Water Resource Assessment, Table V. 2). This combination of exposure and toxicity suggests acute LOCs would still be triggered for estuarine/ marine invertebrates 21 days after maneb is applied.

EIIS reported maneb in three fish kill incidents ( see Section VI, Incidents). One incident occurred in 1973, another in June, 1994 and the latest occurred in August, 1994. In the 1973 and June, 1994 incidents, EFED classified maneb as unlikely to have been responsible for the these fish kills. The final maneb related incident, occurring in August, 1994, was reported by the Maine Department of Agriculture. In this incident roughly 10,000 newly released brook trout were killed in a pond that borders New Brunswick, Canada and Maine. Three pesticides ( maneb, esfenvalerate, and chlorothalonil) recently applied to potatoes surrounding this pond were suspected in this fish kill. Tissue samples of the fish confirmed the presence of all three pesticides ( maneb at 169 ppb, esfenvalerate at 4.2 ppb, and chlorothalonil at 20 ppb) in the fish. These fish samples were taken from both the pond and brooks feeding the pond. All three of these pesticides are very highly toxic to freshwater fish. Maneb's rainbow trout LC 50 is 42.0 ppb, esfenvalerate's rainbow trout LC 50 is 0.26 ppb ( Hicks, L. May, 1995) and chlorothalonil's rainbow trout LC 50 is 42.3 ppb ( US EPA. 1998)]. The submitter of the incident report pointed out there were severe thunderstorms in the area preceding the fish kill which suggest pesticide runoff was a cause in this kill. Based on sampling evidence, EFED believes maneb was a contributory cause in this fish kill.

c. Endangered Species Conclusions Based on available screening level information there is a concern for maneb's potential acute effects on listed freshwater and estuarine/ marine animals and potential chronic effects on listed birds and mammals should exposure actually occur. EFED expects maneb poses a low acute risk to nontarget insects because maneb is practically nontoxic to honeybees, ( acute contact LD 50 > 12 µ g/ bee). Also, there is no incident data reporting adverse effects to honeybees from maneb's use. However, EFED does not assess risk to bees using RQs because a screening level RQ assessment method for estimating the risk to bees is not available. EFED has not developed an exposure design for bees to estimate the risk using a risk quotient method. The Agency does not currently have enough data to perform a screening level assessment for maneb's effects on listed nontarget terrestrial plants or 18 vascular aquatic plants. EFED did not assess chronic risks to freshwater invertebrates, or estuarine/ marine fish due to lack of data. There are no nonvascular aquatic plants or estuarine/ marine invertebrate species on the endangered species list.

d. Endocrine Disruption Concerns The Federal Food, Drug, and Cosmetic Act ( FFDCA) requires EPA, as amended by the Food Quality Protection Act ( FQPA), to develop a screening program. This program is to decide whether certain substances ( including all pesticide active and other ingredients) " may have an effect in humans that is similar to an effect produced by a naturally occurring estrogen, or other such endocrine effects as the Administrator may designate." Following the recommendations of its Endocrine Disruptor Screening and Testing Advisory Committee ( EDSTAC), EPA determined there was scientific basis for including, as part of the program, the androgen and thyroid hormone systems, as well as the estrogen hormone system. EPA also adopted EDSTAC's recommendation including in the Program evaluations of potential effects in wildlife. For pesticide chemicals, EPA will use FIFRA and FFDCA authority to require the wildlife evaluations. EPA will use FFDCA authority to evaluate effects in wildlife from tests that Food and Drug Administration uses to discover effects in humans. As the science develops and allows, EPA may add screening of more hormone systems to the Endocrine Disruptor Screening Program ( EDSP).

When the appropriate screening and or testing protocols being considered under the Agency's Endocrine Disruptor Screening Program have been developed, maneb may be subjected to additional screening and or testing to better characterize effects related to endocrine disruption. The avian reproductive studies reviewed by EFED noted reproductive effects. These effects in mallard duck were decreases in the number of hatchlings as percentages of eggs laid, eggs set, and live 3 week old embryos, and a decrease in the number of 14 day old survivors as a percentage of eggs. For mammals chronic effects were noted such as male parental toxicity resulting in significant increase in lung weight ( both generations) and liver weight ( F1 generation) with lesions noted on these organs in the F1 generation. See Appendix III for a detailed listing of the studies and results. These effects noted in both birds and mammals could be a result of hormonal disruptions. Chronic testing in freshwater fish showed decreased hatchability, fish survival and length of fry. See Appendix III for a detailed listing of the studies and results. These effects noted in freshwater species may be a result of hormonal disruptions.

EFED recommends that when appropriate screening and/ or testing protocols being considered under the Agency's EDSP have been developed, maneb be subjected to more definitive testing to better characterize effects related to its potential endocrine disruptor activity. EFED bases this recommendation on the the potential chronic effects in freshwater fish, birds and mammals. 19 IV. Environmental Fate Assessment The fate of parent maneb was evaluated by considering data on its hydrolytic stability. Practically, parent maneb is short lived, therefore it was important to evaluate the fate and transport of resultant maneb complex by its degradation processes in aqueous phases as well as soil and field environments. Transformation products identified in fate studies were also given the required emphasis here and in the accompanied RED chapter for ETU.

a. Chemical Identity and Physicochemical Properties Maneb is a high molecular weight coordination polymer or a highly coordinated salt complex that is usually represented by one unit of the polymer; a monomeric Mn+ 2 ethylene bis dithiocarbamate ( EBDC). For maneb and related chemicals, the metal is bonded, by bridging, to the EBDC ligand through the sulfur atoms. Information pertaining to the chemical identity of maneb and its physicochemical characteristics are listed in table IV 1. Maneb water solubility was reported to range from range 6 to 200 ppm resulting in complete hydrolytic destruction of maneb into its multi species complex. Variations in reported solubilities were reported, by the registrant, to be related to uncertainties associated with each specific analytical procedure used for its determination ( e. g. efficiency of sampling, energy supplied to promote solubilization and filtration procedure).

Volatilization from water and/ or dry/ moist soil surfaces is not expected to be an important dissipation process based upon vapor pressure and calculated Henry's Law constant. Maneb has a low K ow suggesting that it will not be significantly bio concentrated by aquatic organisms such as fish or aquatic invertebrates.

Table IV 1. Nomenclature and physical chemical identity of the maneb complex and ETU.

CAS [[ 1,2 Ethanediylbis [ carbamodithioato]]( 2)] manganese Structure of Maneb and its Main Degradate ETU CAS Registry No. 12427 38 2 PC Code 014505 Molecular Weight 265.28 ( C4 H6 Mn N2 S4; monomeric unit)

Formulated Products liquid flowable; flowable suspension; wettable powder K OW 5; based on its reported log of 0.69 Vapor Pressure < 9.97x10 11 atm @ 20 0C 1 Water Solubility Rapidly decomposes in water 2 1 US Dept Agric; The Pesticide Properties Database: http:// wizard. arsusda. gov/ rsml/ textfiles/ Maneb 2 Registrant reported solubility in water to range frm 150 to 200 ppm ( Pennwalt Corporation data with no MRID number assigned); Also reported to be 200 ppm ( MRID 455959 01). In a new hydrolysis study ( MRID 453936 01), no solubility data was submitted but the authors described maneb to be " a polymer that is insoluble in a wide variety of non polar and polar solvents, including water". This contradicts with the 150 200 ppm values reported earlier by the registrant. In another reference an " estimated water solubility" was reported to equal 6 ppm ( Wauchope R. D et al. 1991. Res Environ Contam. Toxicol. 123: 1 36). 20 b. Fate Processes Table IV 2 contains a summary of data obtained from guideline studies conducted on maneb. Submitted guideline studies suggest that under typical application rates into natural environment, parent maneb is expected to decompose ( within one day) by hydrolytic reactions and resists both water/ soil photolysis or volatilization. Therefore, hydrolytic reactions are extremely important in the fate of parent maneb and its decomposition to maneb complex.

Maneb complex consists of transient species, degradates and other unidentified materials. Based on data summarized in Table IV 2, the main process involved in parent maneb dissipation is hydrolysis. In contrast, the main processes involved in the fate of resultant maneb complex is its strong affinity for adsorption to the soil/ sediment followed by limited biotic degradation. As a result of biodegradation of the residue, slow and continuous release of transient species and degradates including ETU, at low concentrations, is expected to occur over time.

Mobility of maneb complex in the natural environment is expected to be limited because of its strong affinity to adsorption. In contrast, the degradate of concern ( ETU) is predicted to be susceptible to leaching due to its high solubility and mobility. In the soil environment, ETU lacks stability which can limit its leaching, however, its slow and steady formation from maneb complex can overcome the lack of stability and make it available for leaching at low concentrations.

Table IV 2. Environmental fate data summary for maneb.

Parameter Value Source ( MRID )

Hydrolysis Half lives, for the process of decomposition by hydrolytic reactions in water, depends on the pH of the aqueous media as follows: Acidic: t1/ 2= 4 Hours @ pH 5; Neutral: t1/ 2= 3 Hours @ pH 7; Basic: t1/ 2= 3 Hours @ pH 9. 453936 01 Photo lysis Not important in water ( direct photolysis), No data for indirect photolysis 404656 02 Not important on soil 404656 03 Aerobic Soil Metabolism Half lives were calculated by EFED based on evolved CO2: t1/ 2= 145 days Speyer loamy sand soil; Germany ( 54% sand, 41% silt, 5% clay, pH 5.7, 2.11% organic carbon, and CEC of 9 meq/ 100g soil). t1/ 2= 075 days Speyer sandy loam soil; Germany ( 37% sand, 57% silt, 6% clay, pH 5.8, 0.82% organic carbon, and CEC of 7 meq/ 100g soil). t1/ 2= 270 days Collamer silt loam, a silt loam soil ( 29% sand, 61% silt, 10% clay, pH 6.1, 2.09% organic carbon, and CEC of 13 meq/ 100g soil). 405852 01 405852 01 451452 02 Parameter Value Source ( MRID )

21 Anaerobic Soil; Aerobic Aquatic Metabolism; and Bio accumulation Factor : No acceptable studies.

Anaerobic Aquatic Metabolism Complete degradation within one Hour for parent maneb; The sediment bound part of maneb complex appears to be persistent and maneb complex appears to be practically stable based on evolved CO2 ( Maximum of 2.75% at 275 days) 001633 35 Adsorption Coefficients for maneb complex* ( L Kg 1) Loamy Sand: Kd = 35.70 and KOC = 1,692 ( a. i. used)

Sand: Kd = 7.46 and KOC = 6,412 ( a. i. used) Sandy Loam: Kd = 9.10 and KOC= 978 ( a. i. used) Clay Loam: Kd = 6.97 and KOC = 428 ( a. i. used) Silt Loam: Kd = 2.23 and KOC = 400 ( a. i. used)

Sand: Kd = 3.18 and KOC = 454 ( a. i. used)

Sand: Kd = 10.21 and KOC = 1,459 ( formulation used) Loamy Sand: Kd= 25.96 and KOC = 1,133 ( formulation used) Sandy Loam: Kd= 13.72 and KOC= 1,024 ( formulation used) 405852 03 400472 01 455959 01 455959 02 * A suite of maneb degradation products and transient species.

i. Aqueous Solutions Maneb is a non homogenous or a highly coordinated salt complex, with variable molecular weight. When suspended in water it decomposes rapidly by hydrolytic reactions into transient species and degradates including ETU. The amount affected by hydrolytic reactions appears to depend on particle size distribution and molecular weight distribution of the maneb polymer as well as temperature, metal ions present, and available oxygen. Hydrolytic decomposition results from detachment of the coordinated EBDC ligand from the metal by oxidation. In turn, the water soluble free ligand reacts with water to produce predominantly transient species and ETU.

Two supplemental hydrolysis studies were submitted for maneb. In the first study, 14C maneb was used at levels of 22 40 ppm while in the second study the concentration level was 10 ppm. In the first study ( MRID 404656 01), the parent decomposes rather quickly ( preventing determination of halflives resulting in EBIS ( 5,6 Dihydro 3H imidazo[ 2,1 c] 1,2,4 dithiazole 3 thione; a transient species), un identified degradate, ETU ( 4,5 Dihydro 1H imidazol 2 thione), EU ( 2 Imidazolidinone) and low quantities of glycine ( only at pH 3). The second study consisted of two identical hydrolysis experiments: one was for identifying/ quantifying degradation products while the other was for calculating hydrolysis kinetics ( MRID 453936 01). Major identified degradates, at all pHs, included the transient EBIS and the degradates ETU, EU and one unknown compound. Minor degradates were Jaffe's base " J. B= [ 3( 2 Imidzaolin 2 yl) 2 imidazolidinethione]" and un identified others. Registrant calculated first order half lives at 25 OC were 4, 3, and 3 hours at pH 5, 7, and 9, respectively. 22 Direct photolysis studies on maneb were complicated by its rapid degradation upon suspension in water at concentration levels used ( 22 ppm in MRID 404656 02 and 10 ppm in MRID 420701 02). Identified degradation products were similar to those formed in hydrolysis studies with the exception of formation of minor amounts of ETT ( 4,5 Dihydro 1H imidazol 2 thione 1 thiocarboxamide). It appears that although the degradation of maneb suspensions in water is primarily dominated by hydrolysis, there is a small contribution of photo reactions likely to be linked to reactions related to transient chemical species.

ii. Soil A 30 day photo degradation study on a loamy sand soil showed no significant difference between samples exposed to simulated sunlight and those kept in the dark in the product pattern, the relative amounts of degradation products and their formation/ decline ( MRID 404656 03). Although maneb was never detected ( 14C maneb used was 8.6 ppm), a suite of degradates were detected in the extractable fraction ( 24 19% of the applied radioactivity by methanol and 9 14% of the applied radioactivity by water) included EU, ETU, EBIS, carbimid, and an un identified polar fraction. This indicates that photolysis appear not to be an important processes in dissipation of maneb in soils.

Two supplemental aerobic soil studies were submitted for maneb ( MRID 451452 02 and 405852 01). Many reasons were sited for the assigned classification for these studies. Some of these reasons are related to the nature of the test substance ( may not be able to control) including: impurity ( purity ~ 84.8%) and instability of the test substance ( in the rejected study parent was never detected even at time zero). However, reasons that may have controlled included: non determination of mass balance, exclusion of un extracted bound species, incomplete characterization of degradation products, insufficient duration ( for example, on day 60, 81% of the total residues remained in the soil with substantial degradation appeared to start between days 30 and 60), and inadequacy/ uncertainty of the procedures used in quantifying the parent maneb and degradates ( CS 2 and TLC methods).

One soil was used in the first study with fortification level of 15 21 ppm ( MRID 451452 02) while two soils were used in the second study with fortification level of 9 ppm of 14C maneb ( MRID 405852 01). DT 50 of < 1 day was estimated for the first soil ( MRID 451452 02) while parent was never detected in the other two soils ( MRIDs 405852 01). As shown for EBDCs, parent degradation in aerobic soils can be attributed to chemical hydrolysis rather than bio degradation. Furthermore, EFED suggests a second process to be involved in maneb degradation in aerobic soil; a very slow biodegradation occurring in parallel with the first very rapid hydrolysis. In this scheme, the first process transforms parent maneb into a multi species residue ( maneb complex) while the second process transforms maneb complex into further degradates and CO 2 . Therefore, a second set of half lives were calculated by EFED for the maneb complex as species present in this complex can be precursors for the degradate of concern, ETU. For this purpose, EFED used the mass balance data ( radioactivity data) from both studies and assumed that the only bio degradation of the complex was represented by evolved CO 2 . EFED calculated first order half lives for maneb complex are summarized in Table IV 2 and indicate that the complex is moderately persistent ( half lives in the range of 75 270 days). It is important to note that these estimated half lives are conservative as it is based on complete mineralization of the maneb complex into CO 2 . 7 Clark, D. G., Bauam, H., Stanley, E. L., and Hester, W. F. 1951. Anal. Chem. 23, 1842. Lowen, W. K. 1951. Anal. Chem. 23, 1846 1850. And in 1953. J. AOAC 36, 484 492. Pease, JL. 1957. J. AOAC 40, 1113 1118.

8 Gordon, C. F., Schuckert, R. J. and Bornal, W. E. 1967. AOAC 50 ( 5), 1102 1108. Bighi, C. J. 1961. J. Chromatog. 14, 348 354. Bighi, C. J. 1961. J. Chromatog. 17, 13 22. McLeod, H. A. and McCulley, K. A. 1969. AOAC 52 ( 5), 1226.

23 Transformation products in the supplemental aerobic soil study ( MRID 451452 02) were identified/ quantified only in the basified acetonitrile: water extract by HPLC/ MS. The list of metabolites included:

ETU ( Ethylenethiourea; 2 imidazolidinethione): was 5 6% of the applied at time 0, a maximum 7 8% at 1 day post treatment, 2 3% at 4 days, and < 1% at 30 days.

EBIS or DIDT ( 5,6 dihydro 3H imidazo[ 2,1, c] 1,2,4 dithiazole 3 thione): was 14 18% of the applied at time 0, 10 11% at 2 days, 5 6% at 4 days, and < 1 at 30 days.

EU ( Ethyleneurea; 2 imidazolidone): was a maximum of 1% of the applied at 2 days and decreased to < 1% at 30 days.

iii. Sediment/ Water Systems In an anaerobic aquatic soil study ( MRID 001633 35), the natural lake Mendota sediment ( 55% sand, 40% silt, 5% clay, 8.3% organic matter, 7.9 pH and 14 meq/ 100g CEC) and water ( pH 7.9 and dissolved oxygen 9 ppm) were fortified with ethylene labeled 14C maneb at .9 ppm level. Maneb was never identified, however, radioactivity partitioned into the water and the sediment with the latter being mainly non extractable. Total radioactivity partitioned into the soil increased steadily to reach a plateau of nearly 70% within 100 days of application with most being bound un extractable. Under the aquatic anaerobic conditions of the experiment, maneb degraded by hydrolysis into the transient EBIS, two major degradates ETU and EU, and one minor un identified degradate. Although EBIS was equally divided between the soil extractable and water phases, both ETU and EU were more prominent in the water phase reflecting their high solubility compared to EBIS. No aerobic aquatic metabolism studies have been submitted.

iv. Bound Species, CS 2  data and Half life Determination for EBDCs The registrant claims that the CS 2  method quantitatively determines sulfur containing dithiocarbamates ( parent EBDCs and EBDCs species formed by hydrolytic reactions) in aqueous media, soil and water/ sediment systems including bound species to soil/ sediment. In support, the registrant stated that CS 2 based methods were used early in the discovery of EBDCs 7 and later with improvements in safety and methods employed in CS 2 determination 8. It was also argued that 9 Marshall, W. D. 1977. J. Agri. Food Chem. 25( 2): 357 361.

10 Panel on: Determination of Dithiocarbamate Residue of the Analytical Methods for Residues of Pesticides and Veterinary Products in Foodstuffs of the Ministry of Agriculture, Fisheries, and Food ( MAFF). 1981. Analyst 106: 782 787.

11 MRID 451452 02: Aerobic Soil Metabolism of [ 14C] Mancozeb in Soil, Xenobiotic Laboratories Inc., XBL Report No. RPT006055, 06/ 09/ 00.

24 classical chemistry suggests that the dithiocarbamate functionality would not be stable under the acid hydrolytic conditions used by the CS 2  method to release CS 2 . Many literature examples were cited to indicate method reliability including: demonstration of rapid EBDCs degradation at elevated temperatures and acidic conditions in aqueous media9; recommendation, after careful review, of a similar method for analysis of dithiocarbamate residues by a Panel set up by the Committee for Analytical Methods for Residues of Pesticides and Veterinary Products in Foodstuffs of the Ministry of Agriculture, Fisheries, and Food ( MAFF) in 197710; obtaining a recovery of 98.0 ± 15.8% for mancozeb in freshly fortified control soil samples11; and the extensive use of the method for over 10 years with the greatest effort towards crop residue analysis. Therefore, the registrant argues that the appropriate method for calculating half lives of EBDCs in fate studies is the use of CS 2  method data rather than the evolved CO 2  data. Half lives obtained for parent EBDCs are expected to be conservative due to the fact that CS 2 is expected to evolve not only from parent but also from EBDC species/ degradates containing structural sulfur ( e. g EBIS and ETU).

With one exception, EFED agrees with conclusions stated above and therefore, the use of CS 2  data was acceptable for calculating conservative parent EBDCs half lives in aqueous hydrolysis studies. In addition, EFED suggests that calculated half lives, on the basis of CS 2  data, are acceptable as parent hydrolysis half lives in soil and water/ sediment systems. The exception is that EFED can not consider the significant bound species, in aerobic and aquatic studies, to be included as part of the species determined by the CS 2  method in the absence of their complete characterization. Quantitative generation of CS 2 from largely known EBDC species in aqueous media and possibly in plant residue and freshly fortified soil may not necessarily be comparable to unknown EBDCs species in aged soil/ sediment. In the absence of characterization data on the significant bound species, EFED has no other way to calculate bio degradation half lives other than the use of evolved CO 2  data. EFED recognizes that resultant bio degradation half lives would be conservative as it represents complete mineralization of the EBDCs complex as a whole. Giving the fact that parent EBDCs are short lived, it was necessary to assign these half lives to all of the hydrolytic products which were referred to as the EBDCs complex. EFED believes that it is justified to use the term EBDCs complex and to use CO 2 for calculating its half lives in soil and water/ sediment systems.

In few of the submitted fate studies, only limited data were provided on the significant bound species found in soil and water/ sediment studies. Fractionation of the bound species was performed into fulvic and humic fractions with no further determination of identity/ quantity of species present. Without presenting direct evidence, the registrant stated that consistent with current mechanistic studies, " bound EBDC' is significantly comprised of short chain polar degradates such as 12 Marshall, W. D. 1977. J. Agri. Food Chem. 25( 2): 357 361.

13 Caldwell, J., and Cotgreave, I. A. 1984. Methodol. Surv. Biocchem. Anal. 14, 47; and van Dijken, J. P. 1981. Bos. Arch. Micobiol. 128, 320.

14 Davis, J. 1993. Env. Tox. & Chem. 12: 27 35.

15 Newsome, W. H., et al. 1975. J. Agric. Food Chem. 23( 4): 756 758.

25 ethylenediamine " EDA". In support of this suggestion, the registrant stated that EBDCs may degrade via two different12, routes with both routes eventually forming EDA, which in turn transformed into glycine13. Other cited literature include: a report that the EDA has a Freundlich adsorption coefficient range of 15 238 suggesting that it binds strongly to soil14; and low levels of EDA were identified in soil samples from at least one cropped field treated with maneb, at normal commercial rates, in Ottawa, Canada15.

As stated above, the registrant is proposing two possible theories that may explain the nature of the bound species, namely: EDA and polar natural products. However, in the soil/ sediment studies, sulfur balance appears to decrease with time coinciding with the observed increase in bound species which would suggest that the bound species contain sulfur. EDA has no structural sulfur and its presence as a major part of the bound species can not explain the observed sink in sulfur balance. This sink may, however, be explained by the presence of EBDC species with high affinity to soil/ sediment and in which structural sulfur resists being evolved, as CS 2 , by reagents/ heat used in the CS 2  method. Therefore, EFED is proposing that the bound species are probably sulfur containing compounds that can be " ETU precursors". In absence of data on the identity of the significant and persistent bound species, EFED suggests that the " ETU precursor" theory has more relevance than the EDA because the former can explain the observed sink in sulfur balance. Additional reasons include: EDA was identified at low levels in only one hydrolysis study and this identification was carried out by the TLC method without confirmation; the rapid degradation predicted for EDA in water/ soils using US EPA EPI suite program v3.10; and the non detection ( possibly because they were not tracked) of any form of sulfur bearing compounds ( such as: elemental sulfur, sulfates, CS 2 , H 2 S and others) that may have formed in any of the submitted fate studies.

In order to solve the problem of the identity of bound species, EFED proposes that the registrant conduct one complete aerobic soil study. In the proposed study, greater efforts should be exercised to try to characterize bound species. In addition, EDA; and ETU, EBIS, and all types of sulfur bearing compounds should be tracked ( possibly by labeling structural sulfur in parent EBDC). A sterile soil treatment should also be included in order to determine the relative importance of the active dissipation/ degradation processes in aerobic soils ( binding to soil/ hydrolysis compared to biodegradation 26 c. Mobility Mobility in soil studies were complicated by the instability of the parent as maneb was not identified at time zero in the TLC procedure nor after aging in soil column leaching. Therefore, mobility as indicated by R f or K d / K oc values do not represents maneb but rather maneb complex formed as a result of the observed rapid hydrolysis. Five studies were submitted on mobility of maneb ( MRIDs 00658 59, 405852 03, 400472 01, 455959 01 and 455959 02) and all were classified as supplemental due to non detection of maneb ( fortification in the range of 9 to 24 ppm) and non characterization of the test substance at time zero, use of wettable powder formulations as source for radiolabeled parent, incomplete identification/ quantification of the degradates, and the use of unacceptable methods for the analysis of parent ( i. e bioassay). Most of the listed procedural deficiencies are probably related to parent instability and may not be possible to avoid, however, some may contribute to uncertainty in the results. For example, the use of formulation instead of pure active ingredient increased estimated K oc for the same sandy soil from 454 to 1,459; formulated products were used to increase stability.

In TLC plates, determined R f values ranged from 0.0 to 0.43 ( Table IV 2). These values were taken to indicate immobility to medium mobility of maneb complex in a muck soil and four soils with varied clay and organic matter content. Results from soil column leaching studies were similar as it indicated immobility to medium mobility from estimated K d / K oc with no apparent relationship between estimated mobility and clay or organic carbon contents. Furthermore, column leaching profiles indicated that most of the radioactivity remained in the top 3 4" of the soil column ( 65 93%). Leached radioactivity varied from < 5% in half of the soil column while it ranged from 10 32% in the other half with no apparent relationship to soil texture or organic matter. It is interesting to note that leached radioactivity were < 5% in soils fortified with wettable powder formulations. Leached radioactivity increased from 4% to 12% when one of these soils were fortified with the active ingredient.

In submitted studies, soil residues were not fully characterized as data were only reported for some soils. Reported data show no parent was present and that the dominant constituents of the residue were ETU, EBIS and carbimid in the soil column and ETU and EU in the leachate.

d. Field Dissipation Field dissipation for 14C parent maneb, at a rate of 2 lb a. i/ acre, was studied using in situ soil columns of Keyport silt loam soil ( Clay= 21%, O. C= 1.34%, pH= 5.4, and CEC= 9 meq/ 100g) isolated by 12" sections of 4" diameter stainless steel tubing. The study was conducted for 52 weeks and received a total of 51" of rainfall ( MRID 000889 23). Half life of 1 2 months ( DT 50 . 48 days) was estimated from the " total radioactivity" remained in the whole 12" soil column. EFED calculated first order halflife from the same data gave a t ½ of 301 days ( R2= 0.73). This terrestrial dissipation t ½ is not far from the aerobic soil t ½ of 270 days ( r2= 0.9595) determined for maneb complex based on evolved CO 2 . The study was classified as " supplemental" because it was not conducted under actual use conditions, test substance was not a typical end use product, half life was based on radioactive residues, radioactive residues were not characterized ( i. e. maneb was never identified), degradation 27 products were not addressed and field test data were not reported.

Two terrestrial field dissipation studies were conducted using maneb flowable formulation applied in seven applications of 2.4 lb a. i/ acre each in one week intervals. According to the study authors maneb dissipated with a calculated first order half life ( t 1/ 2 ) of 12 days in Hanford loamy sand plots planted with tomatoes in California ( MRID 417430 01) and 40 days in a Norfolk sandy loam plots planted with snap beans in Georgia ( MRID 417430 02). Although, problems were associated with these two studies, the results indicate that substantial amounts of maneb can be intercepted/ persist on plant surfaces. Disc incorporation of tomato plant residues into the top 6" one month after the last application returned enough maneb residue to raise/ sustain the concentration of maneb in the top 3" of the soil for more than two months. Determined levels of maneb in the top 3" of the soil increased to levels higher than any single soil concentration determined after each of the seven applications. In these studies, the only monitored degradate was ETU which was detected mainly during the application period in the top 3" of the soil and in the range of 0.01 and 0.053 ppm ( near its detection limit of 0.01 ppm which corresponds to degradation of only 1% of the applied parent). In California, ETU was detected too infrequently and at a maximum level of 0.015 ppm ( corresponds to degradation of only 1.6% of the applied parent). In contrast, ETU levels in Georgia ranged from 0.014 to 0.053 ppm corresponding to degradation of only 1.5 to 5.5% of the applied parent. Parent depth profile suggested evidence of leaching to a maximum depth of 6" following the first application in California plots and to a maximum depth of 24" following the first and second applications in Georgia plots; leaching to 24" was attributed to vegetative matter being disked under. At the analytical sensitivity of the method (). 01 ppm), ETU showed no evidence of leaching below the top 3" of the soil in either California or Georgia.

e. Bio accumulation The fish bio accumulation study was waived based on reported low Kow value of 5 for maneb. Kow value indicates low potential for bio concentration in aquatic organisms such as fish. 28 V. Water Resource Assessment Parent maneb is not expected to be present in significant amounts in the environment except for short duration because it will hydrolyze rather quickly into its complex. More details about parent maneb EECs are presented in Appendix I ( section b. i).

This water resource assessment is for maneb complex; the resultant complex from expected rapid hydrolysis of parent maneb in the natural environment. Maneb complex was determined to consist of a suite of chemical species: transient species ( EBIS, carbimid and TDIT), ETU, ETU degradates ( EU, hydantoine and others), and the significant unknown bound species ( suspected of containing persistent precursors for ETU). Among the constituents of maneb complex, ETU is the species of concern. Therefore, a complete water resource assessment was performed for ETU while only surface water modeling was necessary for maneb complex. The resultant EECs were used in the ecological risk assessment of maneb complex.

a. Surface Water Monitoring and Modeling EFED is not aware of surface water monitoring data for maneb. Monitoring data were submitted to the Agency by the EBDC Task Force only for the degradate of concern ETU, this data will be discussed separately in the accompanied RED chapter for ETU. The surface water assessment of maneb complex is therefore based upon computer modeling.

Screening assessments for maneb complex were completed using the linked PRZM and EXAMS models. PRZM/ EXAMS input values are listed in Table V 1 and the results in Table V 2. This data were used for estimating EECs necessary for the ecological risk assessment of maneb complex.

Table V 1. PRZM/ EXAMS Input Parameters for maneb complex*.

Input Parameter Value Reference Molecular Weight ( grams) 265.36 Registrant data Vapor Pressure ( torr) 7.577 e 8 Registrant data Bacterial Bio lysis in the water column ( days) 0 ( Stable) Guidance** because: No aerobic aquatic metabolism study/ significant hydrolysis Bacterial Bio lysis in benthic sediment ( days) 0 ( Stable) MRID 001633 35 Aerobic Soil Metabolism Half life ( days) 271 Upper confidence bound on the mean for three soils ( MRIDs 405852 01 and 451452 02).

Application Method Aerial Product Label Depth of Incorporation ( inches) 0 Product Label Application Efficiency ( fraction) 0.95 Guidance**

Spray Drift ( fraction) 0.05 Guidance** Input Parameter Value Reference 29 Solubility ( mg/ L or ppm) 150 Registrant data Koc ( L Kg 1) 946 Average for eight soils ( MRIDs 405852 03, 400472 01, 455959 01, and 455959 02)

pH 7 Hydrolysis Half life ( days) 0.13 MRID 453936 01 Photolysis Half life( days) 0 ( Stable) MRID 404656 02 * Parent maneb Parameters for Molecular Weight ( grams); Vapor Pressure ( torr); Solubility ( mg/ L or ppm); and pH 7 Hydrolysis Half life were used. ** Guidance for Chemistry and Management Practice Input Parameters For Use in Modeling the Environmental Fate and Transport of Pesticides, Version 2/ November 7, 2000.

Table V. 2. PRZM/ EXAMS output EECs for maneb complex*

Crop Rate ( lbs/ Acre) Number of Applications Interval Peak 96 Hour 21 Day 60 Day Annual Average Apples ( NC) 4.8 4 7 84.0 14.4 4.1 1.8 0.3 Peppers ( FL) 1.6 6 7 113.0 16.7 5.4 2.1 0.4 Potatoes ( ME) 1.6 7 5 47.6 6.7 2.1 1.0 0.2 Tomatoes ( FL) 1.6 7 7 197.9 31.6 9.2 4.0 0.7 b. Ground Water Monitoring and Modeling EFED is not aware of ground water monitoring data for maneb. Monitoring data were submitted to the Agency by the EBDC only for the degradate of concern ETU, this data will be discussed separately in the accompanied RED chapter for ETU. No ground water modeling was performed for maneb complex because the only species of concern is ETU for which modeling can be found in the accompanied ETU RED chapter.

c. Drinking Water Assessment Assessments for surface/ ground drinking water were only performed for the degradate of concern, ETU. This assessment can be found in the accompanied chapter for ETU. 30 VI. Aquatic Exposure and Risk Assessment a. Hazard Summary ( Acute/ Chronic)

Acutely, maneb is very highly toxic to cold water ( freshwater) fish ( LC 50 = 42 ppb), highly toxic to slightly toxic to warm water ( freshwater) fish ( LC 50 = 170  68,000 ppb) and highly toxic to estuarine/ marine fish ( LC 50 = 180 ppb). Early life stage chronic freshwater fish NOAEC and LOAEC values were determined to be 6.1 and 12 ppb, respectively, with reduced hatchability, fish survival and length of fry being the endpoints affected. EFED needs a freshwater fish life cycle test using the TGAI for maneb. EFED needs this testing because the end use product is expected to be transported to water from the intended use site and EECs are greater than one tenth of the NOAEC in the fish early life stage. The PRZM EXAMS modeled peak EECs for selected sites in maneb's current use patterns range from 47.6 ppb for potato applications to 197.9 ppb for tomato applications. Acute toxicity values for aquatic invertebrates suggest that maneb is highly toxic to freshwater invertebrates ( Daphnia EC 50 = 120 ppb) and highly to very highly toxic to estuarine/ marine invertebrates ( oyster EC 50 = 280 ppb and mysid shrimp EC 50 = 3 ppb). No acceptable data has been filed to assess the chronic effects of maneb to freshwater invertebrates, estuarine/ marine invertebrates, or estuarine/ marine fish. EFED needs toxicity tests to fulfill these needs ( see Appendix III). A supplemental Tier II aquatic plant growth study reviewed on maneb showed the EC 50 was 13.4 ppb and the NOAEC was 5 ppb. The endpoint affected was growth inhibition. The test species in the study was green algae ( Selenastrum capricornutum), a freshwater nonvascular plant. There was no data filed to evaluate the affects maneb has on the additional aquatic test species: duckweed ( Lemna gibba), marine diatom ( Skeletonema costatum), blue green algae ( Anabaena flos aquae), and a freshwater diatom. Also, EFED needs a core study for a freshwater green alga ( Selenastrum capricornutum). Aquatic plant growth studies at the Tier I or Tier II level ( guidelines 123 1 or 123 2, respectively) needs to be submitted for these species ( see Appendix III). Toxicological Endpoints Used to Determine Aquatic Risk Quotients ( RQs) for Maneb are presented in Table VI 1.

Table VI 1: Toxicological Endpoints Used to Determine Aquatic Risk Quotients ( RQs) for Maneb Type of Toxicity Organism Species Toxicological Endpoint Acute Freshwater fish rainbow trout ( Oncorhynchus mykiss) LC 50 = 42 ppb Chronic fathead minnow ( Pimephales promelas) NOAEC = 6.1 ppb1 Acute Freshwater invertebrate waterflea ( Daphnia magna) LC 50 = 120 ppb Chronic no data no data Acute Estuarine/ marine fish Atlantic silverside ( Menidia menidia) LC 50 = 180 ppb Chronic no data no data 1. Based on hatchability, fish survival and length of fry 2. Estimated level because of high variability in measured concentrations; analytical procedures were not able to detect maneb below 5 ppb. 31 The EDBCs ( metiram, mancozeb, and maneb), unlike most pesticide active ingredients are not welldefined monomeric substances. The EBDCs are polymeric complexes and are nearly insoluble in water with a high affinity to adsorption by soil or sediment particles. The EBDC portion that dissolves in water and breaks up into a suite of transient species and degradates, is the EBDC complex. This complex is not the parent material by itself. Over time ETU is the dominant transformation product of the EDBCs.

Studies provided estimates of the Parent EBDC material in test concentrations used for evaluating the toxicity to aquatic organisms. These studies showed low recoveries of the test substance. For example, measuring carbon disulfide ( CS 2 ) containing residues, using gas chromatography, one study found roughly a 40% ± 10% average of nominal levels of the " parent complexes". Through filtering and measuring the treatment water, the recovery of " parent complexes" was around 15% ± 10% average of nominal levels ( MRID No. 43525001). Filtering of the test solution before analytical measurement increases the accurate measurement of the test material in solution because this removes the undissolved material in the solution. This remaining, soluble portion of the chemical is more biologically available to aquatic organisms and represents a more conservative estimate of the toxicity to these organisms. These filtered and measured " parent complexes", is the portion of the parent material that is available to aquatic organisms in the environment ( see Figure VI 1).

The EPA's Rejection Rate Analysis determined that studies, testing materials having poor water solubility, were to use measured as opposed to nominal concentrations. Studies were to use measured concentrations for fixing aquatic toxicological endpoints for compounds with poor 32 solubility ( US EPA. December, 1994). EFED believes filtered and measured samples provide a more conservative estimate of the EBDCs' toxicity to aquatic organisms. Also, EFED believes the filtered and measured samples provide a more true estimate of aquatic organism exposure to the EBDC complexes in the environment.

Modeling estimates using PRZM EXAMS are also estimating EBDC complexs by predicting the EECs using the physicochemical properties of the EBDC, parent aerobic soil metabolism half lives and sorption coefficients. Appendix VI shows the toxicity to aquatic organisms found from the various EBDC aquatic toxicological studies. These endpoints are an estimate of the EBDC complex that fixes the toxicities ( that is, LC 50 s, EC 50 s, and NOAECs). The modeling EECs are also estimates. Influences such as particle size, conditions of storage, degree of decomposition, pH, and the presence of other cations ( see Figure VI 1) would always cause difficulty in providing definite aquatic toxicological endpoints for the EBDCs.

b. Exposure and Risk Quotients Tier II modeling ( PRZM/ EXAMS) was performed for selected sites for which EFED currently has modeling scenarios. EFED decided to perform Tier II modeling for maneb to remain consistent with the modeling platform used for the other EBDCs and their common degradate, ETU. Also, EFED expects Tier II modeling provides a more refined EEC estimate. Below ( Figure VI 2) are graphs representing maneb complexes' aquatic risks to non target organisms. EFED selected representative maneb use patterns at maximum application rates and minimum intervals between applications. For a more detailed listing and explanation of maneb's risk, see Appendix IV. EFED does not have a method to evaluate chronic risks to non target aquatic plants.