UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON, D. C. 20460 OFFICE OF PREVENTION, PESTICIDES AND TOXIC SUBSTANCES PC Code No.: 600016 DP Barcode: D 305124 Date: June 21, 2005 SUBJECT: Environmental Fate and Ecological Risk Assessment for Ethylenethiourea ( ETU) a Common Degradate of the Ethylenebisdithiocarbamate Fungicides ( EBDCs): Metiram, Mancozeb, and Maneb. A Part of EFED Section 4 Reregistration for EBDCs for Use in Crops, Some Forestry Trees, Ornamental Plantings, Seed Treatment, and Turf; to Control a Wide Range of Fungi ( 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. ETU is a common degradate of the EBDC fungicides metiram, mancozeb and maneb. This document should be considered as an integral part of the REDs for the three EBDCs.

The following is an overview of our findings:

Risk to Terrestrial and Aquatic Organisms EFED chose mancozeb's use patterns to estimate ETU's exposure and potential risk. EFED didn't estimate ETU exposure or potential risk from metiram's or maneb's uses. EFED expects the ETU exposure and potential risk estimates from metiram's and maneb's uses would be comparable to mancozeb's since comparable applications patterns are used for all 3 EBDCs. EFED chose mancozeb's uses because the use pattern is broad ( that is, many application sites) thus providing a comprehensive view of the potential risks posed by ETU. EFED expected extra modeling and Risk 1 Lethal condition in which the skull is defective with the brain exposed or extruding.

2 Quotients ( RQs) calculations for metiram and maneb would be repetitive further confirming ETU's potential risks.

Mammalian ETU RQs exceed the chronic Level of Concern ( LOC) for all mancozeb's use patterns. ETU effects triggering this potential chronic risk were based on developmental defects of the brain ( that is, exencephaly1, dilated ventricles, and hypoplastic cerebellum) in rats. For small mammals ( 15 gram) feeding on short grass, ETU's chronic RQs range from a high of 37 from mancozeb turf applications to 2 from mancozeb citrus applications. For small mammals feeding on forage and small insects, the chronic RQs range from a high of 21 from mancozeb turf applications to 2 from mancozeb vegetable applications. The ETU potential chronic risk to small mammalian herbivoreinsectivores from mancozeb's use on citrus, only, is below chronic LOCs.

For medium sized mammals ( 35 gram) feeding on short grass, ETU's chronic RQ range from 26 for turf applications of mancozeb to 1 on citrus. For medium sized mammals feeding on forage and small insects, ETU's potential chronic risk are exceeded for all mancozeb's uses except mancozeb's uses on citrus. For medium sized mammals feeding on forage and small insects, the RQs exceeding the chronic LOC range from 14 for turf applications of mancozeb to 1 on vegetables.

For large mammals ( 1,000 gram) feeding on short grass, the RQs range from 6 on turf to 1 on bananas. There are no ETU chronic LOC exceedances to large mammals from mancozeb's use on potato & sugar beet, fennel, peanuts, forestry ( douglas fir), Christmas tree plantations, tobacco, cotton, asparagus, garlic & shallot, ornamentals, the barley crop grouping., vegetables or citrus. For large mammals feeding on forage and small insects, ETU's chronic risk are exceeded for mancozeb's uses on apples, papaya, pachysandra groundcover, and turf ( chronic RQ range 1 on apples to 3 on turf), only.

For granivore mammals ( all sizes), no ETU chronic LOC from mancozeb's uses was exceeded.

EFED does not expect acute risk to mammals from ETU exposure. Acutely, ETU is practically nontoxic ( mouse acute oral LD 50 = 2,300 mg/ kg) to mammals and EFED has not documented any adverse ETU effects from field incidents to mammals. EFED does not have any acute, subacute or chronic toxicity data to evaluate ETU's toxicity to birds.

In aquatic habitats, RQs are below LOCs for ETU's acute risk to freshwater fish, freshwater invertebrates, and nonvascular aquatic plants from mancozeb's uses. EFED has no data to evaluate ETU's acute risks to estuarine/ marine fish and invertebrates. EFED has no data to evaluate ETU's acute risks to vascular aquatic plants. EFED is reserving the need for chronic toxicity testing on freshwater and estuarine marine animals until EFED receives and reviews acute toxicity studies for all the surrogate freshwater and estuarine marine organisms. EFED does not evaluate the chronic risk to aquatic plants because EFED hasn't developed methods to assess chronic risk to plants. 2 In this document three important abbreviations are used: Parent EBDCs, EBDCs complex and Bound species. Parent EBDCs are the polymeric EBDC parents ( metiram, mancozeb and maneb) present in the active ingredients of all of the EBDCs fungicides. EBDCs Complex are suites of multi species complex resulting from degradation of the polymeric EBDC parents ( metiram, mancozeb and 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).

3 Risks to Endangered Species Based on available screening level information there is a potential concern for chronic ETU effects on listed mammals should exposure actually occur. Chronic ETU RQs exceed LOCs for endangered and threatened species of mammals. The Agency does not currently have data on which to evaluate the toxicity of ETU to endangered or threatened birds, estuarine/ marine fish, or aquatic vascular plants. Thus, risks to endangered or threatened species of birds, estuarine/ marine fish, or aquatic vascular plants from ETU exposure is uncertain. EFED is requiring the data to assess the potential risk to endangered or threatened species of birds, estuarine/ marine fish, and aquatic vascular plants through this document. EFED is reserving the terrestrial plant ETU data needs until EFED receives and completes review of the parent EBDC's toxicity to terrestrial plants.

Risk to the Water Resources The unified conceptual model for EBDCs suggests that ETU is produced in the soil system from applied parents through two main processes, namely: initial rapid hydrolysis of the applied parent EBDCs 2and the slow/ continuous aerobic soil bio degradation of the significant absorbed part of the EBDCs complex. ETU produced in the soil system is highly vulnerable to bio degradations but its high water solubility and mobility can give it, at least in part, the potential to leach to groundwater ( GW) at low concentrations. In surfacewater ( SW), the main sources of ETU are: transportation in dissolved run off, formation from the initial rapid hydrolysis of parent EBDCs deposited by drift and formation from the soil associated bound species transported on soil particles by runoff and/ or erosion. Quantities of ETU that reach or form in natural SW are expected to be stable to hydrolysis/ direct photolysis, however, it was reported that it can be removed rather quickly from these waters by indirect photolysis ( half lives of 1 4 days).

EDWCs for ETU, the EBDCs common degradate, were based on a combined monitoring and modeling approach. For surface water, an EDWC/ ETU value of 0.1 ppb was assigned to both chronic/ non cancer and the chronic/ cancer values and was based on a 2 year targeted monitoring study conducted by the EBDC Task Force ( MRID 46145401). The targeted surface water monitoring study provided the chronic values and a lower bound for the acute drinking water exposure estimate. No concentration values above the ETU limit of detection of 0.1 ppb were found in this study. Acute peak values over the 0.1 ppb could have been missed as a result of the 14 day sampling intervals. Therefore, modeling was necessary to estimate these values in order to assign a maximum over the 0.1 ppb and arrive at an acute range. This range of acute EDWCs was established with the lower limit of 0.1 ppb ( based on monitoring) and an upper limit of 25.2 ppb 4 ( based on environmental fate and transport simulation modeling using the linked EPA PRZM and EXAMS models). The highest value in this national level range can be reduced, at the regional level, to 13.9 ppb.

The assigned acute maximum value at both the national and regional levels were based on the currently approved version of PRZM which is only capable of simulating pesticide metabolites through such simplified assumption giving a relatively high uncertainty. It is noted that the assigned acute maximum values ( 25.2 and 13.9 ppb) could be as low as 2 and 1 ppb, respectively when they are corrected proportionally; based on the assumption that PRZM/ EXAMS acute estimates can be corrected so that the maximum chronic value for monitored sites is equal to 0.1 ppb.

EDWC of 0.21 ppb was assigned to ground water ( based on a the targeted monitoring study). This value of 0.21 ppb was the highest measured value in a public drinking water well located in Lee County, Florida. In rural areas, the highest value measured by the EBDC Task Force was 0.57 ppb and was for ground water from a private well near an EBDC treated field in an apple growing region of New York. ETU concentrations in the range of 0.1 to 0.25 ppb were also measured in 8 out of 125 rural wells. Therefore, exposure to higher ETU concentrations ( over the assigned 0.21 ppb) may occur in localities using ground water wells located in proximity or at areas with heavy use of the EBDC fungicides.

It is important to note that the assigned ETU/ EDWCs represent upper bound conservative estimates of the total ETU residual concentrations that might be found in drinking water derived from either surface water and groundwater sources due to the use of the EBDC fungicides. Additionally, ETU was not detected in any of the treated surface/ ground water community drinking water even when it was detected in the raw water ( this was the case for only four samples from two community ground water wells in Florida). The registrant claims that the absence of ETU in potable water from community water supplies is related to its rapid degradation resulting from aeration and chemical treatment ( i. e. chlorination). In contrast, home filters containing stages for water softening and particulate removal were reported to be ineffective at removing ETU from rural well water in at least two sites.

Uncertainties Uncertainty exists in the results of some laboratory and field studies conducted with ETU as the test substance or when it was quantified in studies conducted with parent EBDCs. With the exception of the targeted water monitoring study ( LOQ= 0.10 ppb), the analytical methods for determining unlabeled ETU concentrations were not sensitive ( LOQ= 0.01 ppm). Quantification of ETU in parent EBDCs laboratory studies was also affected by the problems identified in these studies. Relevant RED chapters for EBDCs contains details about these problems and the reader is referred to these REDs. Identification and quantification of ETU degradation products were not complete; except for EU ( ethyleneurea). Therefore, uncertainty exists on conclusions related to the assignment of degradation products to either parent EBDCs or ETU or both.

Estimated environmental concentrations ( EECs) in terrestrial and aquatic systems were calculated by 5 modeling relevant quantities of ETU. For terrestrial exposure, EFED used a conversion rate ( from parent EBDCs to ETU) of 1.6 %, 9.6% for aerobic soil systems and 23.6% for water/ sediment systems. For the terrestrial systems, the conversion rate of parent to ETU on foliage is not known, however, the day after treatment dislodgeable foliar residue data EFED received from HED showed a maximum 1.6% conversion of mancozeb to ETU ( see Table II 2) on treated plants immediately after application.. The HED studies provided mancozeb to ETU conversion information on 3 crops whereas mancozeb is used on more than 20 different crop groupings. Based on this data, though limited, EFED feels it is reasonable to use a 1.6% foliar conversion rate of mancozeb to ETU as a conservative upper bound estimate in this screening level assessment. For the soil and water/ sediment systems, the conversion rates, on concentration basis, were derived from the maximum found in the laboratory studies, higher or lower conversion rates may occur in the natural environment depending on the characteristics of the systems ( e. g. availability of moisture and biological activity). This is considered as an uncertainty along with the assumption that conversion to ETU occurs at application. In this respect, it is noted that the maximum ETU attained in the natural environment is a result of two major processes formation and degradation. This maximum is expected to occur shortly after the parent reaches the aquatic system by drift and much longer after foliar applied parent reaches the soil system.

ETU's effects on some terrestrial and aquatic organisms is uncertain. EFED was unable to assess the acute or chronic ETU risk to birds. EFED was also unable to assess the acute and chronic risks to estuarine/ marine fish and invertebrates, the chronic risks to freshwater fish, or acute risks to aquatic vascular plants. EFED was unable to assess these risks because of lack of toxicity data on these organisms.

EFED is not seeking insect testing of the degradate, ETU. EFED expects substantial ETU exposure to honeybees in flight or while foraging on the nectar or pollen producing parts of plants is unlikely. EFED is assuming a 1.6% conversion rate ( from parent EBDCs to ETU) for terrestrial exposure as a conservative estimate of exposure to ETU. This means the dominant exposure to bees would be from the parent EBDCs, not ETU. EFED expects the parent EBDCs' use patterns would result in ETU exposure to pollinating insects. However, the parent EBDCs are practically nontoxic ( metiram, maneb, and mancozeb acute contact LD 50 s = 437, > 12, and > 179 µ g/ bee , respectively) to honeybees from short term contact exposure ( Guideline 141 1) and there have been no reported adverse effects to pollinating insects resulting from the parent EBDCs' use. EFED also expects any honeybee acute contact toxicity caused by ETU would have been expressed in the acute contact LD 50 guideline testing performed on the parent compounds.

Endocrine Disruption Based on available effects data in mammals, ETU could be a potential endocrine disruptor. The mammalian feeding studies for ETU performed on rats and dogs ranged in time from 3 to 4 months. These feeding studies found the following effects: changes in thyroid hormones; changes in liver enzymes; microscopic changes in the liver and thyroids; increased thyroid weights; and increased relative liver weights. HED reviewed a one dose developmental gavage study done on pregnant laboratory rats. This study determined that treatment related developmental effects caused by ETU involved gross developmental defects, central nervous system defects, skeletal deficiencies, 6 cryptorchidism ( failure of one or more testes to descend into the scrotum), and decreased fetal weight. EFED recommends subjecting ETU to more definitive testing to better characterize effects related to its endocrine disruption when EPA develops suitable screening and testing protocols.

Data Gaps Environmental Fate Submitted fate data are adequate to characterize the environmental fate and transport of ETU. Additional fate data for ETU may be necessary pending resolution of data gaps for the its parent EBDCs. The registrant had submitted a high tier targeted monitoring study for ETU, therefore, no new terrestrial field dissipation study is required at this time. The following Table lists the status of the fate data requirements for ETU.

Status of environmental data requirements for ETU.

Guideline Number Data Requirement Is Data Needed? MRID Number Study Classification 161 1 835.2 Hydrolysis 1 No 404661 03 Acceptable 161 2 835.2 Photo Degradation in Water 1 No 404661 02 Acceptable 161 3 835.2 Photo Degradation on Soil 1 No 404661 01 Acceptable 162 1 835.4 Aerobic Soil Metabolism 2 Reserved 408387 01 Supplemental 451564 01 and 452251 01 162 2 835.4 Anaerobic Soil No Studies submitted 162 3 835.4 Anaerobic Aquatic Metabolism 3 No 001633 35 Acceptable 00088820 402582 03 Supplemental 162 4 835.4 Aerobic Aquatic Metabolism No Studies submitted 163 1 835.1230 Adsorption/ Desorption 4 No 002588 96 Acceptable 000971 58 Supplemental A 2552 29 835.1240 Leaching No 405883 01 Supplemental 163 2 Laboratory Volatility No 423015 01 Rejected 164 1 835.6 Terrestrial Field Dissipation No A 2552 29 Supplemental 000889 23 Guideline Number Data Requirement Is Data Needed? MRID Number Study Classification 7 165 4 850.2 Accumulation in Fish Waived ( Octanol/ water coefficient= 0.5)

1 Additional studies were also submitted under Accession No. 2552 29 but all were rejected. 2 MRID 408387 01 contains two separate experiments one used mancozeb as test material while the other used ETU. 3 MRID 001633 35 is a maneb study in which ETU was tracked and half life estimated. MRID 000888 20 and its supplement 402582 03 contain two separate experiments one used mancozeb as test material while the other used ETU. 4 MRID 002588 96 was also submitted under Accession No. 402229 02. Note that MRID 000971 58 is a laboratory technical report submitted by the registrant.

Ecotoxicity EFED was unable to assess the acute or chronic ETU risk to birds. EFED was unable to assess the acute risks to estuarine/ marine fish or aquatic vascular plants. EFED was unable to assess these risks because the toxicity of ETU to these organisms is unknown. EFED needs studies ( see appendices III and V) to provide this toxicity information. EFED is seeking testing on terrestrial nontarget plant species for all the parent compounds to evaluate the phytotoxicty of these compounds. Terrestrial plant testing on ETU is held in reserve pending results of the parental testing. EFED is reserving the need for chronic toxicity testing on freshwater and estuarine marine animals until EFED receives and reviews acute toxicity studies for all the surrogate freshwater and estuarine marine organisms. EFED does not evaluate the chronic risk to aquatic plants because EFED hasn't developed methods to assess chronic risk to plants. The following Table lists the status of the ecological data needs for ETU. EFED continues to receive EBDC and ETU studies for review. EFED will review and evaluate outstanding studies and include these studies in the revised chapters for the EBDCs and ETU. These outstanding studies may change the environmental risk assessment or the data needs for the EBDCs.

Status of the ecological data requirements for ETU.

Data Requirements Composition1 Use Pattern2 Does EPA Have Data To Satisfy This Need? ( Yes, No, Partially) Bibliographic Citation Study Classification 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, 4, 10, & 11 No Not applicable Not applicable Yes 71 1( b) Acute Avian Oral, Quail/ Duck ( TEP) 1, 2, 3, 4, 10, & 11 No Not applicable Not applicable No 71 2( a) Acute Avian Diet, Quail TGAI 1, 2, 3, 4, 10, & 11 No Not applicable Not applicable Yes 71 2( b) Acute Avian Diet, Duck TGAI 1, 2, 3, 4, 10, & 11 No Not applicable Not applicable Yes 71 3 Wild Mammal Toxicity 1, 2, 3, 4, 10, & 11 No Not applicable Not applicable No 71 4( a) Avian Reproduction Quail TGAI 1, 2, 3, 4, 10, & 11 No Not applicable Not applicable Yes 71 4( b) Avian Reproduction Duck TGAI 1, 2, 3, 4, 10, & 11 No Not applicable Not applicable Yes 71 5( a) Simulated Terrestrial Field Study 1, 2, 3, 4, 10, & 11 No Not applicable Not applicable No Data Requirements Composition1 Use Pattern2 Does EPA Have Data To Satisfy This Need? ( Yes, No, Partially) Bibliographic Citation Study Classification Additional Data Needed Under FIFRA 3( c)( 2)( B)?

8 71 5( b) Actual Terrestrial Field Study 1, 2, 3, 4, 10, & 11 No Not applicable Not applicable No 72 1( a) Acute Fish Toxicity Bluegill TGAI 1, 2, 3, 4, 10, & 11 No Not applicable Not applicable Yes 72 1( b) Acute Fish Toxicity Bluegill ( TEP) 1, 2, 3, 4, 10, & 11 No Not applicable Not applicable No 72 1( c) Acute Fish Toxicity Rainbow Trout TGAI 1, 2, 3, 4, 10, & 11 Yes 45910401 or 46020903 ( duplicate MRID No.) Core No 72 1( d) Acute Fish Toxicity Rainbow Trout ( TEP) 1, 2, 3, 4, 10, & 11 No Not applicable Not applicable No 72 2( a) Acute Aquatic Invertebrate Toxicity ( Freshwater) TGAI 1, 2, 3, 4, 10, & 11 Yes 45910402 or 46020901 ( duplicate MRID No.) Core No 72 2( b) Acute Aquatic Invertebrate Toxicity ( TEP) 1, 2, 3, 4, 10, & 11 No Not applicable Not applicable No 72 3( a) Acute Estu/ Mari Tox Fish TGAI 1, 2, 3, 4, 10, & 11 No Not applicable Not applicable Yes 72 3( b) Acute Estu/ Mari Tox Mollusk TGAI 1, 2, 3, 4, 10, & 11 No Not applicable Not applicable Yes 72 3( c) Acute Estu. Mari Tox Shrimp TGAI 1, 2, 3, 4, 10, & 11 No Not applicable Not applicable Yes 72 3( d) Acute Estu/ Mari Tox Fish ( TEP) 1, 2, 3, 4, 10, & 11 No Not applicable Not applicable No 72 3( e) Acute Estu/ Mari Tox Mollusk ( TEP) 1, 2, 3, 4, 10, & 11 No Not applicable Not applicable No 72 3( f) Acute Estu/ Mari Tox Shrimp ( TEP) 1, 2, 3, 4, 10, & 11 No Not applicable Not applicable No 72 4( a) Early Life Stage Fish ( Freshwater & Estuarine/ Marine) TGAI 1, 2, 3, 4, 10, & 11 No Not applicable Not applicable Reserved 72 4( b) Life Cycle Aquatic Invertebrate ( Freshwater & Estuarine/ Marine) TGAI 1, 2, 3, 4, 10, & 11 No Not applicable Not applicable Reserved 72 5 Life Cycle Fish ( Freshwater & Estuarine/ Marine) TGAI 1, 2, 3, 4, 10, & 11 No Not applicable Not applicable Reserved 72 6 Aquatic Org. Accumulation TGAI 1, 2, 3, 4, 10, & 11 No Not applicable Not applicable No 72 7( a) Simulated Aquatic Field Study ( TEP) 1, 2, 3, 4, 10, & 11 No Not applicable Not applicable No 72 7( b) Actual Aquatic Field Study 1, 2, 3, 4, 10, & 11 No Not applicable Not applicable No § 158.540 PLANT PROTECTION Data Requirements Composition1 Use Pattern2 Does EPA Have Data To Satisfy This Need? ( Yes, No, Partially) Bibliographic Citation Study Classification Additional Data Needed Under FIFRA 3( c)( 2)( B)?

122 1( a) Seed Germ./ Seedling Emerg. Tier I ( TEP) 1, 2, 3, 4, 10, & 11 No Not applicable Not applicable Reserved 122 1( b) Vegetative Vigor Tier I ( TEP) 1, 2, 3, 4, 10, & 11 No Not applicable Not applicable Reserved 122 2 Aquatic Plant Growth Tier I ( TEP) 1, 2, 3, 4, 10, & 11 No Not applicable Not applicable Yes3 123 1( a) Seed Germ./ Seedling Emerg. Tier II ( TEP) 1, 2, 3, 4, 10, & 11 No Not applicable Not applicable No 123 1( b) Vegetative Vigor Tier II ( TEP) 1, 2, 3, 4, 10, & 11 No Not applicable Not applicable No 123 2 Aquatic Plant Growth Tier II ( TEP) 1, 2, 3, 4, 10, & 11 No 45910403 or 46020902 ( duplicate MRID No.) Supplemental Yes3 124 1 Terrestrial Field Study 1, 2, 3, 4, 10, & 11 No Not applicable Not applicable No 124 2 Aquatic Field Study 1, 2, 3, 4, 10, & 11 No Not applicable Not applicable No § 158.490 INSECT TESTING 141 1 Honey Bee Acute Contact TGAI 1, 2, 3, 4, 10, & 11 No Not applicable Not applicable No 141 2 Honey Bee Residue on Foliage ( TEP) 1, 2, 3, 4, 10, & 11 No Not applicable Not applicable No 141 5 Field Test for Pollinators 1, 2, 3, 4, 10, & 11 No Not applicable Not applicable No 1. Composition: TGAI= Technical grade of the active ingredient; PAIRA= Pure active ingredient, radiolabeled; TEP= Typical end use product 2. Use Patterns: 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 Food; 14= Indoor Medical; 15= Indoor Residential 3. Tier I or Tier II aquatic plant testing is recommended.

EFED Label Recommendations There are no recommendations since ETU is degradate and not an active ingredient.

Potential areas of change to the risk assessments for the EBDCs and ETU EFED continues to receive ETU and EU studies for review. These submissions resulted from conversations between OPP and the EBDC Task Force and Dow AgroSciences' acquisition of Rohm & Haas ( see memo dated 1 27 03 from DOW's Shannon Bass). To meet deadlines for sending EFED's risk assessments to SRRD, EFED postponed further study evaluation of new studies. Now EFED will renew evaluation of outstanding studies and intends to include these studies in the revised chapters for the ETU. At a minimum EFED will include the listed studies ( see Table 1) in the next revision. These studies are not expected to change the current risk assessment for ETU. 10 Table 1 ETU and EU degradate studies not included in Section 4 Reregistration for EBDCs as of 5/ 22/ 05 Guideline MRID Number Study Status Test material § 72 4b 46462901 Ethylene Thiourea ( ETU): A Flow Through Life Cycle Toxicity Test with the Cladoceran ( Daphnia magna). Graves, W. C., M. A. Mank, and J. P. Swigert. 1995. Needs EPA Review 96.2% ETU § 72 1c 46462902 Ethylene Urea: A 96 Hour Static Acute Toxicity Test With The Rainbow Trout ( Oncorhynchus mykiss). Palmer, S. J., Kendall, T. Z. and Krueger, H. O. 2001. Needs EPA Review 90.8% EU § 72 2a 46462903 Ethylene Urea: A 48 Hour Static Acute Toxicity Test With The Cladoceran ( Daphnia magna). Palmer, S. J., Kendall, T. Z. and Krueger, H. O. 2001. Needs EPA Review 96.0% EU § 123 2 46462904 Ethylene Urea: A 96 Hour Toxicity Test with the Freshwater Alga ( Selenastrum capricornutum). Palmer, S. J., T. Z. Kendall, and H. O. Krueger 2001. Needs EPA Review 90.8% EU UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON, D. C. 20460 OFFICE OF PREVENTION, PESTICIDES, AND TOXIC SUBSTANCES Environmental Fate and Ecological Risk Assessment for Ethylenethiourea ( ETU)

A Common Degradate of the EBDC Fungicides: Metiram, Mancozeb, and Maneb 2 Imidazolidinethione 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 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 a. Sources of Environmental Contamination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 b. Approach to Risk Assessment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 III. Integrated Environmental Risk Characterization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 a. Overview of Environmental Risk Characterization . . . . . . . . . . . . . . . . . . . . . . . . . . 14 b. Key Issues of Uncertainty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 i. Environmental Fate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 ii. Ecological Effects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 c. Endangered Species Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 d. Endocrine Disruption Concerns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 IV. Environmental Fate Assessment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 a. Production from EBDCs in Laboratory and Field Studies . . . . . . . . . . . . . . . . . . . . 21 i. Aqueous Media . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 ii. Soil Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 iii. Water/ Sediment Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 b. Chemical Identity and Physicochemical Properties . . . . . . . . . . . . . . . . . . . . . . . . . . 24 c. Fate Processes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 i. Aqueous Solutions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 ii. Soil Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 iii. Sediment/ Water Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 d. Mobility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 e. Field Dissipation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 f. Bio accumulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 g. Transformation Products . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 V. Water Resource Assessment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 a. Surface Water Modeling for Aquatic Exposure . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 b. Drinking Water Assessment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 VI. Aquatic Exposure and Risk Assessment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 a. Hazard Summary ( Acute/ Chronic) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 b. Exposure and Risk Quotients . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 c. Aquatic Risk Assessment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 i. Incidents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 ii. Endocrine Disruptors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 iii. Endangered Species . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 iii VII. Terrestrial Exposure and Risk . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 a. Hazards Summary ( Acute/ Chronic) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 b. Exposure Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 c. Risk Quotients . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 d. Terrestrial Risk Assessment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 i. Incidents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 ii. Endocrine Disruptors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 iii. Endangered Species . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 APPENDIX I: Additional Fate Data & Background for Models Used . . . . . . . . . . . . . . . . . . . 51 APPENDIX II: Hoerger Kenaga Estimates & Fate v. 5.0 Model . . . . . . . . . . . . . . . . . . . . . . . 52 a. Hoerger Kenaga Estimates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 b. Fate v. 5.0 Model Terrestrial Exposure Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 c. Fate v. 5.0 Model Sample Output for ETU Residues from Mancozeb's Use . . . . . . . 53 APPENDIX III: Ecological Hazards Assessment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 a. Review . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 b. Toxicity to Terrestrial Animals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 i. Birds, Acute, Subacute and Chronic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 ii. Mammals, Acute and Chronic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 1. Acute Oral . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 2. Acute Dermal and Inhalation Toxicity Testing . . . . . . . . . . . . . . . . . . 59 3. Mammalian Subchronic Toxicity Testing . . . . . . . . . . . . . . . . . . . . . . 59 4. Mammalian Reproductive & Developmental Toxicity Testing . . . . . . 59 iii. Insect Acute Contact . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 iv. Terrestrial Field Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 c. Toxicity to Aquatic Organism. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 i. Toxicity to Freshwater Animals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 1. Freshwater Fish, Acute . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 2. Freshwater Invertebrates, Acute . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 ii. Aquatic Field Studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 d. Toxicity to Plants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 i. Terrestrial Plants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 ii. Aquatic Plants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 iii. Aquatic Plant Field Studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64 APPENDIX IV: Environmental Exposure Assessment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 a. Review of Risk Quotients ( RQs) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 b. Exposure and Risk to Terrestrial Animals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66 i. Birds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66 iv ii. Mammals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67 c. Aquatic Organisms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74 i. Review . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74 ii. Freshwater Fish . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75 iii. Freshwater Invertebrates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76 iv. Exposure and Risk to Nontarget Plants: Aquatic Plants . . . . . . . . . . . . . . . . 77 d. Endangered Species . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78 e. Ecological Incidents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78 APPENDIX V: US EPA Ecological Incident Information System . . . . . . . . . . . . . . . . . . . . . . 79 APPENDIX VI. HED Memorandum on Surface/ Ground water EDWCs . . . . . . . . . . . . . . . . . 81 REFERENCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111 a. Environmental Fate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111 b. Ecological Effects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114 1 Lethal condition in which the skull is defective with the brain exposed or extruding.

1 I. Executive Summary ETU is a common degradate of metiram, mancozeb and maneb ( EBDCs). The EBDCs are nonsystemic, contact and disease prevention fungicides belonging to a chemical group classified as ethylenebisdithiocarbamate ( EBDC) fungicides. Pesticide applicators use EBDCs on many crops, some forestry uses, ornamental plantings, seed treatment, and turf.

Mammalian ETU Risk Quotients ( RQs) exceed the chronic Level of Concern ( LOC) for all mancozeb's use patterns. ETU effects triggering this potential chronic risk were based on developmental defects of the brain ( that is, exencephaly1, dilated ventricles, and hypoplastic cerebellum) in rats. For small mammals ( 15 gram) feeding on short grass, ETU's chronic RQs range from a high of 37 from mancozeb turf applications to 2 from mancozeb citrus applications. For small mammals feeding on forage and small insects, the chronic RQs range from a high of 21 from mancozeb turf applications to 2 from mancozeb vegetable applications. The ETU potential chronic risk to small mammalian herbivore insectivores from mancozeb's use on citrus, only, is below chronic LOCs.

For medium sized mammals ( 35 gram) feeding on short grass, ETU's chronic RQ range from 26 for turf applications of mancozeb to 1 on citrus. For medium sized mammals feeding on forage and small insects, ETU's potential chronic risk are exceeded for all mancozeb's uses except mancozeb's uses on citrus. For medium sized mammals feeding on forage and small insects, the RQs exceeding the chronic LOC range from 14 for turf applications of mancozeb to 1 on vegetables. For large mammals ( 1,000 gram) feeding on short grass, the RQs range from 6 on turf to 1 on bananas. There are no ETU chronic LOC exceedances to large mammals from mancozeb's use on potato & sugar beet, fennel, peanuts, forestry ( douglas fir), Christmas tree plantations, tobacco, cotton, asparagus, garlic & shallot, ornamentals, the barley crop grouping., vegetables or citrus. For large mammals feeding on forage and small insects, ETU's chronic risk LOCs are exceeded for mancozeb's uses on apples, papaya, pachysandra groundcover, and turf ( chronic RQ range 1 on apples to 3 on turf), only. For granivore mammals ( all sizes), no ETU chronic LOC from mancozeb's uses was exceeded.

EFED does not expect acute risk to mammals from ETU exposure. Acutely, ETU is practically nontoxic ( mouse acute oral LD 50 = 2,300 mg/ kg) to mammals and EFED has not documented any adverse ETU effects from field incidents to mammals. EFED does not have any acute, subacute or chronic toxicity data to evaluate ETU's toxicity to birds.

The acute LOCs for ETU are not exceeded for freshwater fish and freshwater invertebrates. The acute LOCs were not exceeded for nonvascular aquatic plants. This was based on testing in 1 of 4 surrogate test species. Because ETU is, acutely, practically nontoxic to mammals EFED expects the acute risk to mammals will be low. Since the EBDCs are practically nontoxic to bees and substantial bee contact with ETU is unlikely, EFED expects the acute risk to terrestrial nontarget insects will be low. Because EFED lacks toxicity data, EFED is uncertain about ETU's acute risks to birds, 2 In this document three important abbreviations are used: Parent EBDCs, EBDCs complex and Bound species. Parent EBDCs are the polymeric EBDC parents ( metiram, mancozeb and maneb) present in the active ingredients of all of the EBDCs fungicides. EBDCs Complex are suites of multi species complexes resulting from degradation of the polymeric EBDC parents ( metiram, mancozeb and 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).

3 Sue XU. 2000, Environmental Fate of Ethylenethiourea. California Department of Pesticide Regulation, CA, US.

2 estuarine/ marine fish, estuarine/ marine invertebrates, and aquatic vascular plants. Because EFED lacks chronic toxicity data, EFED is uncertain about the chronic risks to birds. EFED is reserving the need for chronic toxicity testing on freshwater and estuarine marine animals until EFED receives and reviews acute toxicity studies for all the surrogate freshwater and estuarine marine organisms. EFED does not evaluate the chronic risk to aquatic plants because EFED hasn't developed methods to assess chronic risk to plants.

Applied parent EBDCs are the main source for environmental contamination with ETU as it is one of the main constituents of the EBDCs degradate complex ( EBDCs Complex) 2. When parent EBDCs are applied, major portion reaches directly targeted crop foliage and supporting soil system while much smaller portion reaches aquatic systems by drift. Parent EBDCs reaching foliage, soil and aquatic systems are expected to decompose relatively fast by hydrolytic reactions into the EBDCs Complex which contains ETU. Based on the unified conceptual model for all EBDCs, ETU is mainly produced ( as part of the EBDCs Complex) by both the initial rapid hydrolysis of parent EBDCs and the possible slow/ continuous degradation of the soil/ sediment associated complex.

ETU produced in and transported to the soil system is highly vulnerable to bio degradations but its high water solubility and mobility can give it, at least in part, the potential to leach to ground water at low concentrations. In surface water, sources of ETU are: formation from the initial rapid hydrolysis of parent EBDCs deposited by drift, transportation by runoff in dissolved form, and the possible continuous/ slow formation from bound species transported on soil particles by runoff and/ or erosion. Quantities of ETU that reach or form in natural surfacewater are expected to be stable to hydrolysis/ direct photolysis, however, it was reported that it can be removed rather quickly from these waters by indirect photolysis ( half lives of 1 4 days) 3.

ETU is expected to partition into the air from dry soil surfaces as indicated from its vapor pressure. However, its high water solubility/ relatively low Henry's law constant may render such partition unimportant because ETU forms from EBDCs only when water is present ( i. e. in wet soil or water bodies). Additionally, if ETU reaches air it is expected to partition into rain or be affected with hydroxy radicals ( half life of 8 9 days was reported for ETU in the air). ETU is likely to be not persistent in air. The hydroxy radical half life of ETU in air is calculated by the USEPA computer program EPI suite v. 3.01 ( AOPWIN) to be 0.9 hours. A low K ow value is reported for ETU, 3 therefore the chemical is not expected to be significantly bio concentrated by aquatic organisms such as fish.

ETU may be a potential endocrine disruptor based on effects in mammals. The mammalian feeding studies for ETU performed on rats and dogs ranged in time from 3 to 4 months. These feeding studies found the following effects: changes in thyroid hormones; changes in liver enzymes; microscopic changes in the liver and thyroids; increased thyroid weights; and increased relative liver weights. HED reviewed a one dose developmental gavage study done on pregnant laboratory rats. This study determined that treatment related developmental effects caused by ETU involved gross developmental defects, central nervous system defects, skeletal deficiencies, cryptorchidism ( failure of one or more testes to descend into the scrotum), and decreased fetal weight. EFED recommends subjecting ETU to more definitive testing to better characterize effects related to its potential endocrine disruption when EPA develops suitable screening and testing protocols.

Targeted surfacewater ( SW) monitoring data were used to assign a value of 0.1 ppb for both the chronic/ non cancer and chronic/ cancer ETU/ EDWCs. This decision was based on a 2 year targeted SW monitoring program in which no concentration values were measured above the ETU detection limit of 0.1 ppb in either raw or treated community water from surface water sources. Sampling was executed every 14 day during the historical EBDCs  use season; acute peak values over the 0.1 ppb could have been missed. Therefore, modeling was necessary to estimate these values in order to assign a maximum value for an acute range which was established with a lower limit of 0.1 ppb ( based on monitoring, MRID 46145401) and an upper limit of 25.2 ppb ( based on modeling using the linked EPA PRZM and EXAMS models). The highest value in this national level range can be reduced, at the regional level, to 13.9 ppb. Additionally, the assigned acute maximum values ( 25.2 and 13.9 ppb) could be as low as 2 and 1 ppb, respectively when they are corrected proportionally ( based on the assumption that PRZM/ EXAMS acute estimates can be corrected so that the maximum chronic value for monitored sites is equal to 0.1 ppb).

An EDWC of 0.21 ppb ETU was assigned to ground water based on a the targeted ground water ( GW) monitoring study. This value of 0.21 ppb was the highest measured value in a public drinking water well located in Lee County, Florida. In rural areas, the highest value measured by the EBDC Task Force was 0.57 ppb and was for ground water from a private well near an EBDC treated field in an apple growing region of New York. ETU concentrations in the range of 0.1 to 0.25 were also measured in 8 out of the monitored 125 rural wells suggesting that exposure to higher ETU concentrations ( over the assigned 0.21 ppb) may occur in localities using ground water wells located in proximity or at areas with heavy EBDCs use. Assigned ETU/ EDWCs represent upper bound conservative estimates of the total ETU residual concentrations that might be found in drinking water derived from either surface water and ground water sources due to the use of the EBDC fungicides.

It is important to note that ETU was not detected in any of the treated surface/ ground water community drinking water even when it was detected in the raw water. The registrant claims that the absence of ETU in potable water from community water supplies is related to its rapid degradation resulting from aeration and chemical treatment ( i. e. chlorination). In contrast, home filters were reported to be ineffective at removing ETU from rural well water examined at two sites. 4 II. Introduction a. Sources of Environmental Contamination ETU is a common degradate of ethylenebisdithiocarbamate ( EBDC) fungicides, mancozeb, metiram, and maneb. The EBDCs are nonsystemic, have both contact toxicity with preventive control, and control a wide range of fungi. The formulation types for EBDCs include dusts, water dispersible granules ( dry flowables), flowable concentrates, and wettable powders.

As a degradate of the EBDCs, EFED expects the presence of ETU wherever the use of these fungicides occur. The use patterns of the EBDCs include wide use on crops, forestry uses, and uses in ornamental plantings, seed treatment and turf. The reader may refer to the detailed listing of these uses in the REDs for mancozeb, metiram, and maneb. For the purpose of ecological risk assessment, EFED calculated EECs for ETU's terrestrial exposure based on mancozeb's use pattern ( Table II 1).

Table II 1. Mancozeb use patterns.

Crop Maximum Application Rate Number of Applications Minimum Application Interval ( day) Per Treatment In Total Apples, Cranapple, Pear & Quince 4.8 lbs a. i./ acre 19.2 lbs a. i./ acre/ year 4 7 Asparagus 1.6 lbs a. i./ acre 6.4 lbs a. i./ acre/ crop cycle 4 10 Bananas & Plantain 2.4 lbs a. i./ acre 24 lbs a. i./ acre/ crop cycle 10 14 Barley, Oats, Rye, Triticale & Wheat 1.6 lbs a. i./ acre 4.8 lbs a. i./ acre/ crop cycle 3 7 Caprifig 3.2 lbs a. i./ 100 gal dip treatment 1 Not applicable Citrus 0.9 lbs a. i./ acre Not specified 7 Corn ( unspecified) ( East of the Mississippi River) 1.2 lbs a. i./ acre 18 lbs a. i./ acre/ crop cycle 15 4 Corn ( unspecified) ( West of the Mississippi R.) 1.2 lbs a. i./ acre 12 lbs a. i./ acre/ crop cycle 10 4 Cotton 1.6 lbs a. i./ acre 6.4 lbs a. i./ acre/ crop cycle 4 10 Cranberry 4.8 lbs a. i./ acre 14.4 lbs a. i./ acre/ year 3 7 Cucumber 2.4 lbs a. i./ acre 19.2 lbs a. i./ acre/ year 8 7 Fennel 1.6 lbs a. i./ acre 12.8 lbs a. i./ acre/ year 8 7 Flax 0.4 lbs a. i/ 100 lbs seed ( Seed treatment) 1 Not applicable Grapes ( East of the Rocky Mountains) 3.2 lbs a. i./ acre 19.2 lbs a. i./ acre/ year 6 7 Grapes ( West of the Rocky Mountains) 2.0 lbs a. i./ acre 6.0 lbs a. i./ acre/ year 3 7 Melons & Squash 2.4 lbs a. i./ acre 19.2 lbs a. i./ acre/ crop cycle 8 7 Onion, Garlic, & Shallot 2.4 lbs a. i./ acre 24 lbs a. i./ acre/ crop cycle 10 7 Papaya 2.0 lbs a. i./ acre 28.0 lbs a. i./ acre/ year 14 5 Crop Maximum Application Rate Number of Applications Minimum Application Interval ( day) Per Treatment In Total 5 Peanuts 1.6 lbs a. i./ acre 12.8 lbs a. i./ acre/ crop cycle 8 7 Pineapple 25.6 lbs a. i/ acre ( Pre plant dip treatment) 1 Not applicable Potato & Sugar Beet 1.6 lbs a. i./ acre 11.2 lbs a. i./ acre/ year 7 5 Rice 0.2 lbs a. i/ 100 lbs seed ( Pre plant seed treatment) 1 Not applicable Safflower 0.1 lbs a. i/ 100 lbs seed ( Pre plant seed treatment) 1 Not applicable Sorghum 0.2 lbs a. i/ 100 lbs seed ( Pre plant seed treatment) 1 Not applicable Tobacco 2.0 lbs a. i./ acre Not specified 5 Tomato 2.4 lbs a. i./ acre 16.8 lbs a. i./ acre/ crop cycle 7 7 Vegetables a 1.5 lbs a. i./ acre Not specified 7 Forestry ( Douglas Fir) 3.2 lbs a. i./ acre Not specified 14 Ornamental Trees ( Christmas tree plantations) 3.2 lbs a. i./ acre Not specified 14 Ornamentals b 1.6 lbs a. i./ acre Not specified 7 Ornamentals ( pachysandra  groundcover) 13.9 lbs a. i./ acre 69.5 lbs a. i./ acre/ crop cycle 5 10 Turf ( golf course) 17.4 lbs a. i./ acre Not specified 5 Turf c 19.0 lbs a. i./ acre Not specified 5 a Beets ( unspecified), Broccoli, Brussel sprouts, Cabbage, Carrots, Cauliflower, Chard ( Swiss, Collards, Coriander, Dill, Endive, Kali, Kohlrabi, Leeks, Lettuce, Mustard, Mustard Cabbage, Parsley, Parsnip, Radish, Rape, Roquette ( Arugula), Rutabaga, Spinach & Turnip. b Trees, Herbaceous plants, Nonflowering plants & Woody shrubs and Vines. c Commercial/ Industrial, Sod farm & Residential.

In an agricultural setting, ETU is introduced into or formed in the environment in four ways following application of the EBDC fungicides. First, ETU may be added with the applied formulation as it may form in these formulations as a result of particle size reduction ( i. e. dry and wet milling), due to unfavorable storage and/ or due to dilution in the tank mix. Second, ETU is formed, as part of the EBDCs complex, in soil pore water/ water bodies from hydrolytic degradation of parent EBDCs following its application/ wash off to soils and/ or after reaching water bodies by drift. Third, ETU is produced from hydrolysis of some species of the EBDCs complex left in soil pore water or transported by run off into the water, and left unbound to the sediment, in water/ sediment systems. Fourth, ETU may be produced continuously at low concentrations from the slow degradation of the soil/ sediment associated Bound species. ETU presence in the formulations of EBDCs is difficult to establish, but is expected to be unimportant in most cases. Therefore, ETU production from EBDCs in the environment is controlled mainly by the second and to a less extent the third and fourth processes stated above, with the seconds being the most important.

ETU may also be introduced into the environment from other sources such as: EBDC manufacturing/ formulating facilities, EBDC commercial products ( other than metiram, mancozeb and maneb), use in industry ( as an accelerator in synthetic rubber production and as vulcanizing agent in 6 production of some types of poly ethers). Environmental contamination from these industrial uses are not covered by this document. 7 b. Approach to Risk Assessment The risk assessment for ETU was based on its EECs in important environmental compartments. These EECs were calculated by estimating expected quantities of ETU that would be produced from application of EBDCs. Resultant ETU quantities were then modeled to arrive at its EECs using physicochemical and fate properties determined for ETU. The latter EECs along with related ecological effects data ( i. e., available aquatic and terrestrial toxicity data), were used to evaluate and characterize ecological risk of ETU to the environment.

For terrestrial exposure, EFED calculated the EECs for ETU based on mancozeb's use pattern. EFED could have calculated RQs based on the use patterns of the other two parent compounds for ETU, metiram and maneb. EFED decided not to make these extra calculations since expected results would be the same and would only further confirm ETU's chronic risk to mammals. Also, mancozeb has the broadest use pattern ( most sites of application) and EFED expected mancozeb's uses would provide a more comprehensive view of the risks posed by ETU. The EECs modeled for ETU assumed 1.6 percent conversion of mancozeb to ETU as an estimate of exposure.

HED receives dislodgeable foliar residue ( DFR) dissipation half life data ( guideline 875.2100) to estimate exposures to individuals that occur as a result of working in an environment that has been previously treated with a pesticide ( also referred to as reentry exposure). DFR is the amount of pesticide residue on treated leaves. For mancozeb HED ( Dole and Dawson, 2003) provided the following Table ( Table II 2).

Table II 2. Day After Treatment ( DAT) Summary of Mancozeb and ETU Dislodgeable Foliar Residue ( DFR)

MRID ( Year) CROP ( Location) Application Method Lb ai/ acre ( Application Interval) Mancozeb DAT 0 DFR ( ug/ cm2) [ A] ETU DAT 0 DFR ( ug/ cm2) [ B] DAT 0 DFR Mancozeb to ETU Conversion (%) [ B/( A + B)]

449596 01( 99) 418369 01( 91) 411339 01( 86) 411339 01( 86) CA Grapes ( Poplar) CA Grapes ( Biola) CA Grapes ( Madera) CA Grapes ( Fresno) Airblast Airblast Airblast Airblast 1.9 + 2.0 ( 7 days) 1 3.2 * 3 ( 1 month) 2 3.2 * 3 3.2 * 3 4.53 13.7 or 20.13 3.4 3.7 0.0545 0.074 or 0.109 Not available Not available 1.2 0.5 or 0.5 Not available Not available 449617 01( 99) NC Green House Tomatoes Handgun 2.3 + 2.3 ( 7 days) 5.1 0.0128 0.3 449596 02( 99) 449596 02( 99) NY Apples WA Apples Airblast Airblast 5.0 + 5.0 ( 7 days) 5.0 + 5.0 ( 7 days) 15.9 16.5 0.22 0.053 1.4 0.3 418369 02( 91) 418369 02( 91) 449596 03( 99) 449596 03( 99) 425602 01( 91) CA Field Tomatoes MD Field Tomatoes CA Field Tomatoes FL Field Tomatoes FL Field Tomatoes Ground boom Airblast Ground boom Ground boom Ground boom 2.4 * 3.0 ( 10 days) 2.3 * 5 ( 7 15 days) 1.7 + 1.7 ( 6 days) 2.5 + 2.5 ( 6 days) 2.3 * 3.0 ( 7 days) 6.85 5.33 6.8 7.4 6.29 0.070 0.087 0.0092 0.0023 0.021 1.0 1.6 0.1 0.03 0.3 449585 01( NA) NC Bermuda grass PA Kentucky bluegrass CA Tall fescue Ground boom Ground boom Ground boom 16.1 * 1 10.5 * 1 11.3 * 1 0.15 0.078 0.19 Not available Not available Not available Not available Not available Not available Note 1  This means that 1.9 lb ai/ acre was applied followed by an application of 2.0 lb ai/ acre 7 days later. Note 2  This means that 3.2 lb ai/ acre was applied 3 times with an application interval of one month between each application. Note 3  This means the results were due to either 1.2 or 1.75 cm diameter leaf punches used to take the DFR samples. This difference resulted from a reporting discrepancy in the study. 8 The DAT 0 DFR data in Table II 2 is the mancozeb and ETU determined to be present on the leaves of the treated plants immediately after application. Mancozeb is used on more than 20 crop grouping ( see Table II 1) or more than 40 crops. These DFR studies provides mancozeb to ETU degradation information on 3 crops. Given this limited information EFED feels it is reasonable to use a 1.6% foliar conversion rate ( MRID 418369 02, MD Field Tomatoes) of mancozeb to ETU as a conservative upper bound estimate in this screening level assessment.

EFED calculated the exposure estimates of ETU to be a fraction of the exposure estimates for mancozeb. EFED modeled mancozeb labeled rates using FATE version 5.0 then multiplied the EECs by the 1.6% conversion rate. The FATE model 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 adjusted by Fletcher, and others ( 1994) and assumes 1st order dissipation. Appendix II provides Kenaga estimates and an explanation of the model with sample production reports.

EFED needs total foliar dissipation residue or total foliar residue ( TFR) half life information as a modeling input value to estimate 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 data chiefly from Willis and McDowell ( 1987). Since ETU TFR halflife information was not available from Willis and McDowell ( 1987), EFED sought surrogate information from HED. HED receives dislodgeable foliar residue ( DFR) dissipation half life data ( guideline 875.2100) to estimate exposures to individuals that occur from working in an environment previously treated with a pesticide ( also referred to as reentry exposure). DFR is pesticide residue on treated leaves' surface. EFED would expect the TFR half life values for ETU would be at least as long as the ETU DFR values, since the dislodgeable residue is a part of the total foliar residue. For ETU, HED ( Dole and Dawson, 2003, 2003a, and 2003b) provided the following Table ( Table II 3) with MRID Nos. The Mancozeb Task Force provided the Biswis study through a literature submission ( Ollinger, 2005). The available ETU DFR and TFR data ( Table II 3) represents 4 crops ( grapes, apples, tomatoes, and turf). Mancozeb is used on more than 20 crop grouping ( see Table II 1) or more than 40 crops.

Table II 3. Summary of ETU DFR & TFR Data for Crops.

MRID ( Year) CROP EBDC Applied Lb ai/ Acre ( Application Interval) DFR Half life ( Days) TFR Half life ( Days)

449596 01( 99) 420449 04( 90) CA Grapes CA Grapes Mancozeb Maneb 1.9 + 2.0 ( 7 days) 1 3.2 * 3.0 ( 30 days) 2 10.4 Not available Not available Not available 449596 02( 99) 451946 01( 99) NY Apples NY Apples Mancozeb Maneb 5.0 + 5.0 ( 7 days) 4.8 + 4.8 ( 7 days) 7.7 8.4 Not available Not available 449596 02( 99) 451946 01( 99) 413399 01( 88) WA Apples WA Apples CA Apples Mancozeb Maneb Metiram 5.0 + 5.0 ( 7 days) 4.8 + 4.8 ( 7 days) 4.8 * 3 ( 42 days) 28.0 17.7 41.9 Not available Not available Not available 449617 01( 99 NC Green House Tomatoes Mancozeb 2.3 + 2.3 ( 7 days) 9.1 Not available Table II 3. Summary of ETU DFR & TFR Data for Crops.

MRID ( Year) CROP EBDC Applied Lb ai/ Acre ( Application Interval) DFR Half life ( Days) TFR Half life ( Days)

9 425602 01( 91) 420449 03( 91) Biswis, et al. 2003 Biswis, et al. 2003 FL Field Tomatoes FL Field Tomatoes India Tomatoes India Tomatoes Mancozeb Maneb Mancozeb Mancozeb 2.3 * 14 ( 7 days) 1.9 * 9 ( 7 days) 1.3 * 3 ( 15 days) 2.7 * 3 ( 15 days) 19.5 Not available Not available Not available Not available Not available 4.33,4 4.73,4 449596 03( 99) 419615 01( 90) CA Field Tomatoes CA Tomatoes Mancozeb Maneb 2.5 + 2.5 ( 6 days) 2.4 * 3.0 ( 10 days) 4.3 Not available Not available Not available 449585 01( NA) NC Bermuda grass PA Kentucky bluegrass CA Tall fescue Mancozeb Mancozeb Mancozeb 16.1 * 1 10.5 * 1 11.3 * 1 Not available Not available Not available Not available Not available Not available Note 1  This means that 1.9 lb ai/ acre was applied followed by an application of 2.0 lb ai/ acre 7 days later. Note 2  This means that 3.2 lb ai/ acre was applied 3 times with an application interval of one month between each application. Note 3  Half life values calculated by EFED from the data provided in the study. Note 4  TFR was from homogenized samples of the tomato fruit, only submitted by the Mancozeb Task Force ( Ollinger, 2005).

Based on the results of the studies listed in Table II 3, EFED would expect a variation in the half life values for ETU. 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 effects of climate was a greater effect than the effects 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). HED selected these ETU DFR half life values from 8 mancozeb studies, 6 maneb studies, and 1 metiram study submitted. HED's based its selection on the best data quality to represent a crop and climate scenario ( T. Dole, per. com., 7/ 23/ 04). The ETU half life results from the 1988 metiram study on California apples ( MRID 413399 01) may have resulted from leaf degradation interference. The samples on this study were not dislodged until arriving at the laboratory following overnight shipment. Current guidelines require the samples to be dislodged within 4 hours of collection ( T. Dole, per. com., 7/ 23/ 04).

EFED reviewed ETU half life data submitted by the Mancozeb Task Force ( Ollinger, 2005., Mar. 7, 2005). Based on Biswas, et al. ( 2003), EFED estimated the mean high end ETU TFR on homogenized tomatoes was 4.7 days. It should be noted plant food items for wildlife includes leaves, fruit, pods, and seeds. The screening level half life value can't be limited to fruit, only, and must be a high end estimate across all plants for screening level assessments. There was some indication of ETU translocation to tomatoes ( Biswas et al, 2003), however the information provided was insufficient to conclude ETU is systemic.

ETU is not applied in the environment, by itself, but is a degradate of the Parent EDBC. Estimates of ETU presence on wildlife food items is dependent on the presence of the Parent EDBC. As long as the Parent EDBC is present, ETU will be produced through hydrolysis. For modeling purposes, the estimated 1.6% conversion ( see Table II 2) of Parent EDBC to ETU is the more important factor in determining the presence of ETU than the half life value of ETU. This means EFED expects ETU will be produced after each application of the Parent EDBC. The presence of ETU is directly dependent on the degradation rate of the Parent EDBC. As the Parent EDBC degrades ETU will be produced. EFED is estimating this level to be 1.6% of the Parent EDBC based on foliar 10 conversion rate. Using ETU TFR half life modeling values identical with the modeling values used for the Parent EDBC insures this 1.6% change over of Parent EDBC to ETU is included in the ETU exposure estimate and more accurately reflects ETU exposure to terrestrial wildlife.

For modeling purposes, this means the half life of the degradate, ETU, needs to be the same as the half life of the Parent EBDC. Since EFED based the terrestrial EEC modeling used in this ETU assessment on mancozeb's use pattern, EFED used a 35 day TFR half life value for ETU's terrestrial EEC modeling. This 35 day half life value matches the half life value used for mancozeb's terrestrial EEC modeling used in the mancozeb RED. This wouldn't be the case if EFED expected ETU's TFR half life was longer than the Parent EBDC. In such cases, EFED would use the high end estimated TFR half life value of ETU because EFED would expect build up of ETU beyond the TFR half life of the Parent EBDC. EFED doesn't expect DFR or TFR half life values for ETU to be longer than 35 days. Except for the questionable results from the 1988 metiram study on California apples showing a 41 day ETU DFR half life, none of the DFR or TFR half life values listed in Table II 3 are longer than 35 days.

For aquatic exposure, EFED calculated EECs for ETU in these systems using the Pesticide Root Zone Model version 3.1.2 beta ( Carsel and others, 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 ETU from EBDCs 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 2,600 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 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 resultant ETU from EBDCs turf use pattern was assessed for drinking water and aquatic environments using only one application of EBDCs parents at 17.4 lb a. i/ acre. However, ETU/ EDWCs and EECs were also calculated/ characterized for the possibility of three applications of EBDCs parents at 17.4 lb a. i/ acre at 5 and 7 days intervals.

To evaluate the potential risk to aquatic and terrestrial organisms, from ETU exposure, EFED calculated risk quotients ( RQs). RQs are the ratio of estimated environmental concentrations ( EECs) to ecotoxicity values ( see Appendix IV). EFED based the EECs for ETU on maximum application rates for the EBDCs' registered use patterns. EFED compared these RQs to the level of concern ( LOC) ( see Appendix IV for these values) to decide potential risk to nontarget organisms.

EFED is uncertain about ETU's acute risks to birds, estuarine/ marine fish, estuarine/ marine invertebrates, and aquatic vascular plants. Because EFED lacks chronic toxicity data, EFED is uncertain about the chronic risks to birds. EFED needs studies ( see appendices III) to provide this toxicity information. EFED is seeking testing on terrestrial nontarget plant species for all the parent compounds to evaluate the phytotoxicty of these compounds. EFED is reserving terrestrial plant 11 testing requests for ETU awaiting the results of the parental testing. Currently, the Agency does not perform RQ assessments for chronic risk to plants, acute or chronic risks to nontarget insects, or chronic risk from granular or bait formulations to birds or mammals. EFED also uses adverse effect incident data in evaluating a chemical's risk.

A summary of the risk assessment is presented in a diagram ( Figure II 1) which shows the single stressor, ETU in blue, and the assessment endpoints in yellow. It also shows which nontarget organisms are at potential risk and where areas of uncertainty exists. The assessment endpoints include the potential short term ( that is, acute) and long lasting ( that is, chronic) effects to these organisms that may result because of exposure to ETU. Most of the uncertainties shown in Figure II 1 result from missing data although some of the uncertainties are due to lack of methodology. For example, EFED has not developed a method for evaluating the chronic risks to plants. 12 Figure II 1. Summary of Risk Assessment for ETU. 4 The issue of Bound species is discussed in detail in the accompanied RED chapters for metiram, mancozeb and maneb.

13 III. Integrated Environmental Risk Characterization a. Overview of Environmental Risk Characterization EFED expects ETU to be a potential chronic risk to mammals ( LOCs are exceeded). No acute LOCs were exceeded for freshwater fish and freshwater invertebrates. No acute LOCs were exceeded for nonvascular aquatic plants. The nonvascular aquatic plant testing was based on testing in 1 of 4 surrogate test species. Because ETU is, acutely, practically nontoxic to mammals EFED expects the acute risk to mammals will be low. Since the EBDCs are practically nontoxic to bees and significant bee contact with ETU is unlikely, EFED expects the acute risk to terrestrial nontarget insects will be low. Because EFED lacks toxicity data, EFED is uncertain about ETU's acute risks to birds, estuarine/ marine fish, estuarine/ marine invertebrates, and aquatic vascular plants. Because EFED lacks chronic toxicity data, EFED is uncertain about the chronic risks to birds. EFED is reserving the need for chronic toxicity testing on freshwater and estuarine marine animals until EFED receives and reviews acute toxicity studies for all the surrogate freshwater and estuarine marine organisms. EFED does not evaluate the chronic risk to aquatic plants because EFED hasn't developed methods to assess chronic risk to plants.

ETU is a product of degradation of applied EBDC fungicides and is classified by the Agency as a B2 carcinogen ( US EPA ,2002). Environmental risk characterization requires estimation of expected environmental concentrations ( EECs) of ETU in various environmental compartments. These concentrations are dependent on physicochemical properties and fate and transport processes for EBDCs ( ETU parents) as well as those for ETU itself. EBDCs' properties/ processes are important in characterizing ETU production ( when, where, and quantities/ rates), while ETU's properties/ processes are important in characterizing its dissipation through degradation and/ or transportation within/ into various environmental compartments.

When EBDCs are applied, the major portion will reach the soil directly or indirectly through wash off from plant surfaces. Another much smaller amounts of EBDCs might reach water bodies by drift and/ or run off.

In terrestrial environments, EBDCs are applied to growing, rain fed and/ or irrigated crop foliage. Therefore, moisture is expected to be available in sufficient quantities to cause decomposition of these compounds, by hydrolytic reactions into EBDCs complex ( ETU included) at plant surfaces and in soil pore water. Hydrolytic reactions are expected to be variable but relatively fast. Most conservative estimation indicates that applied parent EBDCs can be converted into EBDCs complex ( ETU included), within one day, one week and two weeks from the last application of metiram, mancozeb and maneb, respectively. ETU in the EBDCs complex is expected to partition into soil pore water while most of the other constituents of the EBDCs complex appear to partition into the soil particles as bound species. Unfortunately, in submitted aerobic soil experiments, no complete characterization was conducted for these significant bound species; and claimed, by the registrant, to be dominated by ethylene diamine ( EDA) without experimental proof. In these experiments, sulfur material balance suggested that bound species are suspicious of being precursors for ETU ( possible presence of sulfur in the Bound species). This residue ( the bound species) 4 is persistent and appear to bio degrade slowly possibly into low amounts of ETU resulting in another slow but continuous 5 Blazquez, C. H. 1973. J. Agric. Food Chem. 21( 3): 330 332.

6 Lethal condition in which the skull is defective with the brain exposed or extruding.

14 source of low concentrations of ETU in the soil environment ( over that produced by initial hydrolysis).

In contrast, a small fraction of the applied parent EBDCs reaches aquatic environments by drift resulting in very low parent concentrations. At such concentrations, parent EBDCs reaching water bodies would be highly vulnerable to hydrolytic decomposition and be completely converted into EBDCs complex ( ETU included). With time, hydrolytic reactions are capable of increasing the concentration of ETU in the EBDCs complex to near dominance. However, ETU produced in these aquatic systems is expected to be susceptible to degradation by microbial activity ( in biologically active systems) and/ or by indirect photolysis.

Physicochemical and fate properties of ETU were used in the process of estimating EECs for ETU. Abiotic hydrolysis and direct photolysis laboratory studies conducted with ETU show that it is stable, although it was reported to be highly susceptible to indirect photolysis in natural waters. Short halflives were estimated for ETU in aerobic soil ( few days) while field dissipation studies suggested longer half lives (< one week). Given its high solubility and mobility ( water solubility: 20,000 ppm, K d , Freundlich: 0.51 to 1.14), ETU has the potential, at least in part, to leach to ground water. However, ETU that forms and/ or reaches natural surface waters may not persist due to reported short indirect photolysis half lives related to the presence of sensitizers. For example, ETU degraded with a half life of < 1 day ( occurred between the time of application and sampling at day 0) in a natural drainage water obtained from a field in Florida5.

The limited ecotoxicological data for ETU does not exceed the acute LOCs for freshwater fish, freshwater invertebrates, and nonvascular aquatic plants. In contrast, EBDCs complex ( suite of transient species and degradation products from the parent EBDC) do present a risk. The RQs, for the EBDCs complex, exceed LOCs for these aquatic organisms. Based on this, EFED expects an early acute exposure risk to these aquatic organisms from the uses of the EBDC fungicides. This acute risk is caused by the EBDCs complex and is expected to disappear over time as the complex degrades rather quickly into ETU by hydrolytic reactions in aquatic environments. The acute fish studies showing risk from the EBDCs complex 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. At some point beyond this 48 to 120 hour exposure period, EFED would expect a reduced acute toxicity to these organism when the conversion of the EBDCs complex to ETU is complete.

EFED does not expect a significant acute risk from ETU to mammals. ETU is practically nontoxic to mammals ( the mouse acute oral LD 50 is 2,300 mg/ kg). Based on reported incidents in Ecological Incident Information System ( EIIS), EFED has not been able to document any adverse effects to terrestrial organisms for the parent EBDCs or ETU. Because ETU is practically nontoxic to mammals on an acute basis and EFED found no documented incidents linking the parent EBDCs or ETU to adverse effects in mammals, EFED did not calculate acute RQs for mammals.

Mammalian ETU Risk Quotients ( RQs) exceed the chronic Level of Concern ( LOC) for all mancozeb's use patterns. ETU effects triggering this chronic risk were based on developmental defects of the brain ( that is, exencephaly6, dilated ventricles, and hypoplastic cerebellum) in rats. For 15 small mammals ( 15 gram) feeding on short grass, the ETU's chronic RQs range from a high of 37 from mancozeb turf applications to 2 from mancozeb citrus applications. For small mammals feeding on forage and small insects, the chronic RQs range from a high of 21 from mancozeb turf applications to 2 from mancozeb vegetable applications. There are no ETU chronic LOC exceedances to small mammalian herbivore insectivores from mancozeb's use on citrus. For medium sized mammals ( 35 gram) feeding on short grass, ETU's chronic RQ range from 26 for turf applications of mancozeb to 1 on citrus. For medium sized mammals feeding on forage and small insects, ETU's potential chronic risk are exceeded for all mancozeb's uses except mancozeb's uses on citrus. For medium sized mammals feeding on forage and small insects, the RQs, exceeding the LOC, range from 14 for turf applications of mancozeb to 1 on vegetables. For large mammals ( 1,000 gram) feeding on short grass, the RQs range from 6 on turf to 1 on bananas. There are no ETU chronic LOC exceedances to large mammals from mancozeb's use on potato & sugar beet, fennel, peanuts, forestry ( douglas fir), Christmas tree plantations, tobacco, cotton, asparagus, garlic & shallot, ornamentals, the barley crop grouping., vegetables or citrus. For large mammals feeding on forage and small insects, ETU's chronic risk are exceeded for mancozeb's uses on apples, papaya, pachysandra groundcover, and turf ( chronic RQ range 1 on apples to 3 on turf), only. For granivore mammals ( all sizes), no ETU chronic LOC from mancozeb's uses were exceeded.

EFED calculated the EECs for ETU's terrestrial exposure based on mancozeb's use pattern. EFED could also have calculated RQs based on the use patterns of the other two parent compounds for ETU, metiram and maneb. EFED decided not to make these extra calculations since expected results would be the same. Also, mancozeb has the broadest use pattern ( that is, most sites of application) and EFED expected mancozeb's uses would provide a more comprehensive view of the risks posed by ETU.

EFED presumes applications of EBDCs 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 EBDCs applications will result in degradation of parent EBDCs to ETU on plant surfaces. Based on hydrolytic reaction rates, this degradation is estimated to occur from one day to two weeks following application. The frequent applications of EBDCs in wet conditions, would provide a continuous exposure to ETU.

There are over twenty different crop groupings listed in each RED for mancozeb and maneb. The RED for metiram shows two different crop groupings. Each of these groupings represent a unique use pattern based on rates of application, number of applications allowed a crop cycle, and minimum intervals between applications. EBDCs are used throughout the US. Based on these uses, there is a high likelihood that applications will result in ETU exposure to mammals. Mammals are in and around all sites included in labels. As an example, cottontail rabbits, deer, raccoons, opossums, skunks, woodchucks, muskrats, and groundhogs all feed on parts of tomato plants. As well as feeding, some of these animals use areas where tomatoes are grown for brood rearing, cover and loafing ( Gusey and Maturdo, 1973). The applications of mancozeb to tomatoes occur from seedling emergence ( spring) until 5 days before harvest ( in late summer or early fall) which coincides with the timing of the mammal pursuits mentioned. EFED expects mammalian exposure to ETU to be continuous during this time period. Even though EFED expects a continuous exposure to mammals from ETU, the developmental study used for ETU's chronic assessment endpoint results from a short term exposure. This means that even a single application could result in a potential chronic 16 toxicity risk to mammals from ETU exposure.

As mentioned above, EFED has not been able to document any adverse effects to terrestrial wildlife for EBDCs or ETU based on reported incidents in EIIS. These incident reports mainly deal with field mortality ( that is, acute exposure) of wildlife and phytotoxicity issues. EFED contends chronic problems that affect wildlife from the use of the parent EBDCs, whether they result from short term or long term exposure, would go unnoticed in the field. Because of this, EFED would not expect incident reports, dealing with chronic adverse effects, for the EBDCs and their common degradate, ETU.

b. Key Issues of Uncertainty i. Environmental Fate Two types of fate studies were used in collecting laboratory and field fate data on ETU. The 1st type used parent EBDCs as the test substance in order to study ETU formation from these parents. The 2nd type used ETU as the test substance in order to study the fate of ETU in various experimental laboratory and field conditions.

In calculating EECs for ETU, application equivalent rates of ETU were calculated using the maximum ETU produced in the 1st type of studies ( laboratory studies were used). Uncertainty exists in the determined maximum ETU because of problems associated with parent EBDCs laboratory studies which were complicated by the introduction of artifacts before the experiments, during parent preparation, and at the end of the experiment during extraction. In these experiments, rapid degradation of the parent occurred before time zero and in most aqueous solution experiments, an EBDC complex ( suite of degradation products) rather than parent was actually observed. In addition, identification/ quantification of ETU and other degradation products were largely dependent on the TLC methods which were affected by poor separation of the degradates and the occurrence of degradation caused by solvent systems employed. The reader is referred to RED chapters of EBDCs for more information about stated problems. In modeling, complete conversion of applied parent EBDCs into ETU was assumed to occur at application resulting in another uncertainty. Fate studies have shown that complete conversion of applied parent EBDCs into ETU does not occur at application as ETU forms by more than one processes occurring at different times and in variable rates.

For the 2nd type of studies, uncertainty exists in the results of some laboratory and field experiments ( unlabeled ETU) conducted with analytical methods not sensitive enough to measure the concentration of ETU in soil and water ( LOQ = 0.01 ppm). Fortunately, new and adequate analytical methods were used in water monitoring studies ( LOQ = 0.10 ppb in water samples; MRID 448804 01). Additionally, in these ETU studies, identification and quantification of ETU degradation products were not complete; except of EU ( ethyleneurea). Therefore, uncertainty exists on conclusions related to the assignment of degradation products to either parent EBDCs or ETU or both. The list of these degradates include: HYD ( hydantoine or glycolylurea), J. B. ( Jaffe's base), Glycine, IMID ( 2 imidazoline), and EDA ( ethylenediamine). However, these degradates are considered to be " ETU degradation products" based on results of studies on maneb and ETU in 7 R. C. Rhodes 1977. Studies with manganese 14C Ethylene bis dithiocarbamate ( 14C Maneb) fungicide and 14C Ethylenethiourea ( 14C ETU) in plants, soil, and water. J. Agr. Food Chem., Vol. 25: 3, pp528 533.

17 plants, soil, and water7. 18 ii. Ecological Effects Because EFED lacks toxicity data, EFED is uncertain about ETU's acute risks to birds, estuarine/ marine fish, estuarine/ marine invertebrates, and aquatic vascular plants. Because EFED lacks chronic toxicity data, EFED is uncertain about the chronic risks to birds. EFED needs effects studies ( see appendices III and V) to provide this toxicity information. EFED is seeking testing on terrestrial nontarget plant species for all the parent compounds to evaluate the phytotoxicty of these compounds. EFED is reserving terrestrial plant testing requests for ETU awaiting the results of the parental testing. EFED is not seeking insect testing of the degradate, ETU. EFED believes substantial ETU exposure to honeybees in flight or while foraging on the nectar or pollen producing parts of plants is unlikely. EFED is assuming a 1.6% conversion rate ( from parent EBDCs to ETU on foliage) for terrestrial exposure as a conservative estimate of exposure to ETU. This means the dominant exposure to bees would be from the parent EBDCs not ETU. Although the parent EBDCs' use patterns would result in exposure to pollinating insect the parent EBDCs are practically nontoxic ( metiram, maneb, and mancozeb acute contact LD 50 s = 437, > 12, and > 179 µ g/ bee , respectively) to honeybees from short term contact exposure ( Guideline 141 1) and there have been no reported adverse effects to pollinating insects resulting from the parent EBDCs' use. Finally, EFED believes any honeybee acute contact toxicity caused by ETU would have been expressed in the acute contact LD 50 guideline testing performed on the parent compounds.

c. Endangered Species Conclusions Based on available screening level information there is a potential concern for chronic ETU effects on listed mammals should exposure actually occur. Chronic ETU RQs exceed LOCs for endangered and threatened species of mammals. The Agency does not currently have data on which to evaluate the toxicity of ETU to endangered or threatened birds, estuarine/ marine fish, or aquatic vascular plants. Thus, risks to endangered or threatened species of birds, estuarine/ marine fish, or aquatic vascular plants from ETU exposure is uncertain. EFED is requiring the data to assess the potential risk to endangered or threatened species of birds, estuarine/ marine fish, or aquatic vascular plants through this document. EFED is reserving the terrestrial plant ETU data needs until EFED receives and completes review of the parent EBDC's toxicity to terrestrial plants.

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). 19 The mammalian feeding studies for ETU performed on rats and dogs ranged in time from 3 to 4 months. These feeding studies found the following effects: changes in thyroid hormones; changes in liver enzymes; microscopic changes in the liver and thyroids; increased thyroid weights; and increased relative liver weights. HED reviewed a one dose developmental gavage study done on pregnant laboratory rats. This study determined that treatment related developmental effects caused by ETU involved gross developmental defects, central nervous system defects, skeletal deficiencies, cryptorchidism ( failure of one or more testes to descend into the scrotum), and decreased fetal weight. See Appendix III for a detailed listing of the studies and results. These toxicological effects noted in mammals could be a result of hormonal disruptions and may suggest that ETU may be an endocrine disruptor. Based on these effects in mammals, EFED recommends that when EPA develops suitable screening and testing protocols, considered under the Agency's EDSP, ETU be subjected to more definitive testing to better characterize effects related to its potential endocrine disruption. 20 IV. Environmental Fate Assessment Formation of ethylene thiourea ( ETU) is a result of EBDCs degradation. ETU formation from EBDCs has been observed in laboratory hydrolysis, and metabolism studies, as well as in field studies. Abiotic hydrolysis and photolysis laboratory studies with ETU show that ETU is stable for at least 30 days. Although it has been shown that ETU rapidly degrades in the presence of microorganisms ( half lives of few days in soil aerobic conditions), longer ETU half lives in the field have been reported (< one week).

ETU is highly soluble and mobile with potential to leach to ground water and/ or reach surface water by runoff in dissolved form. However, in natural surface waters indirect photolysis is expected to affect the possibilities for surfacewater contamination. Soil associated Bound Species, suspected producer of ETU, can also reach surface water adsorbed on soil particles and carried by erosion.

a. Production from EBDCs in Laboratory and Field Studies ETU appears to be the main transformation product of the EBDC fungicides that results from abiotic and biotic degradation processes in both field and laboratory studies. Other transient species and degradates were also identified. Qualitative and quantitative characterization of the degradates in laboratory and field experiments were complicated by the introduction of artifacts before the experiments, during parent preparation, and at the end of the experiment during extraction. In these experiments, rapid degradation of the parent occurred before time zero and in most aqueous solution experiments, EBDCs complex rather than parent was actually used. In addition, identification of transient species and degradates was largely dependent on the TLC methods which was affected by poor separation of the degradates and the occurrence of degradation caused by the solvent systems employed.

Hereunder is a summary of reported laboratory data on degradation of EBDCs and production of ETU, transient species and other transformation products. The summary covers only major processes and should be considered with the above mentioned experimental uncertainties.

i. Aqueous Media Hydrolysis is the major process for production of ETU from parent EBDCs in aqueous buffered media; parents are unstable to hydrolysis. Table IV 1 lists hydrolysis half lives and degradation products for metiram, mancozeb and maneb at pH 7. The results indicate that parent EBDCs are highly susceptible to hydrolysis in the order of maneb ( highest) then mancozeb followed by metiram ( lowest). Initial suite of degradation products included transient species, ETU and other degradation products ( i. e. the EBDCs Complex). ETU appears to increase with time to dominance ( from 18% up to 36% of ETU within 30 days) while transient species reach maximums/ disappear early. ETU has been shown to resist hydrolysis, indicating that a complete conversion of parent EBDCs into hydrolysis persistent ETU, is possible to occur in most environmentally relevant aqueous media. 21 Table IV 1. Summary of hydrolysis studies for various EBDCs at pH 7 ( Note: to arrive at % ETU, on concentration bases, the value in the table should be multiplied by 0.385%).

Test Material 1 and ( Concentration in ppm) Hallife ( days) Length of Study ( Days) Transient Species 2 ETU (% of Applied, as parent) Other Degradates 3 MRID Reference ( Analysis Procedure) Max. at ( Day) Min. at ( Day) Major Minor Metiram Complex ( 6 141) ND 40 Carbimid 93%

( 5) 87% ( 40) None EU; HYD; Polar; Unknowns 001551 89 ( TLC)

Metiram ( 16.7) 1.8 10 Degradates were not identified/ quantified 001467 64 Mancozeb ( 20) 0.7 28 In the DER for the addendum ( MRID 402582 01), data were reported only in range of values. In summary, the transient species was EBIS; ETU reached a max. of 21 37% at day 2 and declined to 1 7% at day 14; major degradates were EU, HYD and unknowns; and minor degradates were J. B and ethylene diamine ( EDA). 000971 62 402582 01 ( TLC)

Maneb ( 10) 0.1 30 EBIS 47.7% ( 30) No decline EU; Unknowns Three unknowns 453936 01 ( TLC) 1 In the case of the first metiram study, a high concentration suspension ( 2,143 ppm) was used. Only the dissolved part is considered here and is referred to as Metiram Complex. It is important to note that, during the experiment, the total concentration of this complex changed with time from < 1% of the parent applied (. 6ppm) at time zero to nearly 7% (. 141ppm) at the end of the experiment. 2 These products are considered as transient species because they form early in the process, reach maximums and decline sharply. 3 Major= when maximum is > 10%; Minor= when maximum is < 10%. ND= Not determined.

ii. Soil Systems In aerobic soil systems, initial hydrolysis of parent EBDCs appears to be the major process in their degradation and the rapid production of the EBDCs complex. EFED believes that short aerobic soil half lives reported for all EBDCs, by the registrant, are mainly related to the rapid hydrolytic conversion of parent EBDCs into EBDCs complex. Following initial hydrolysis, the major part of EBDCs complex becomes bound to the soil ( bound species) and possibly degrade slowly into ETU. Therefore, ETU is produced in the soil system partially by initial rapid hydrolysis of parent EBDCs and possibly by the slow biodegradation of the bound species ( long Bound species half lives) .

Following formation, produced ETU is subjected to rapid degradation ( short aerobic soil half lives). Final ETU concentration is therefore dependent on two competing processes: formation ( abiotic and biotic) and biotic degradation. As shown in Table IV 2, ETU forms in aerobic soils as a major degradate at the short term and end up as a minor one at the long term. Data indicates that the range of maximum conversion rates, on concentration basis, is between 0.9 and 9.3% occurring mainly within one week. 22 Table IV 2. Summary of aerobic soil studies for EBDCs ( Note: to arrive at % ETU, on concentration bases, the value in the table should be multiplied by 0.385%).

Soil Texture and ( Parent EBDCs Concentration in ppm) Hal life ( days) 1 Length of Study ( Days) Transient Species 2 ETU (% of Applied) Other Degradates 3 MRID Reference ( Analysis Procedure) Max. at ( Day) Min. at ( Day) Major Minor Metiram Loam (. 10) < 1 454 365 EBIS 12.5% ( 4) < 1% ( 30) None Unknown 001552 88 ( TLC)

Loamy Sand (. 10) < 1 388 365 EBIS 2.3% ( 1) < 1% ( 60) None Unknown Silt Loam (. 20) 7 33 390 59 EBIS 4.1% ( 7) < 1% ( 59) None EU 451452 03 ( HPLC/ MS)

Loamy Sand (. 8) 1 387 365 TDIT EBIS Carbimid 11.2% ( 2) 0.0% ( 14) None EU 459069 01 ( HPLC/ LC)

Mancozeb Sandy Loam ( 3.3) < 0.1 121 120 EBIS 22.0% ( 1) 2.2% ( 120) EU Unknowns 457445 01 ( HPLC/ TLC)

Loamy Sand ( 3.3) < 0.1 161 120 EBIS 24.8% ( 1) 1.3% ( 120) EU Unknowns Silty Clay Loam ( 3.3) < 0.1 143 120 EBIS 14.7% ( 1) < 1% ( 120) EU Unknowns Maneb Loamy Sand ( 8.78) Parent Never Detected 145 32 EBIS Carbimid 20.4% ( 7) 13% ( 32) None EU; Unknowns 405852 01 ( TLC)

Sandy Loam ( 9.12) Parent Never Detected 75 30 EBIS Carbimid 10.0% ( 30) No decline EU; Unknowns None Silt Loam ( 15 21) < 1 270 60 EBIS 7.2% ( 1) < 1% ( 30) EU; Unknowns None 451452 02 ( HPLC/ MS)

1 Top values are half lives calculated, by the registrant, for parent EBDCs ( from CS2 data). Bottom values are halflives calculated, by EFED, for EBDCs complex ( from CO2 data) 2 These products are considered as transient species because they form early in the process, reach maximums and decline sharply. 3 Major= when maximum is > 10%; Minor= when maximum is < 10%.

iii. Water/ Sediment Systems Processes occurring in water/ sediment systems appear to be similar to those in the soil systems. Initial hydrolysis of parent EBDCs appears to be a major process in the rapid production of the EBDCs complex and the short half lives reported by the registrant for all EBDCs. Following initial hydrolysis, the major part of the EBDCs complex becomes bound to the sediment as bound species 8 Nash R. G. and Beall L. M. 1980. J Agric Food Chem 28: 322.

23 and appear to degrade slowly possibly into ETU; which partitions into the water column. Unlike the soil system, data indicate that ETU remained the major degradation product in the system as a whole. The range of maximum conversion rates, on concentration basis, observed in the three aquatic studies was from 15 to 24% occurring within 3 days ( Table IV 3).

Table IV 3. Summary of aerobic soil studies for EBDCs ( Note: to arrive at % ETU, on concentration bases, the value in the table should be multiplied by 0.385%).

Water/ Sediment System and ( Parent EBDCs Concentration) Hal life ( days) 1 Length of Study ( Days) Transient Species 2 ETU (% of Applied) Other Degradates 3 MRID Reference ( Analysis Procedure) Max. at ( Day) Min. at ( Day) Major Minor Metiram ( 1: 1.4 1.5 Aerobic water: Anaerobic sediment)

Pond water/ Loamy Sand Sediment ( 0.6 ppm) 0.9 858 100 EBIS 61.4% ( 1) 47% ( 100) Unknowns EU 459334 01 ( HPLC)

Stream water/ Loamy Sand Sediment ( 0.6 ppm) 0.5 173 100 EBIS 52.2% ( 1) 20% ( 100) Unknowns EU Mancozeb ( soil slurry containing 48% moisture)

Soil Slurry ( 20 ppm) 92 ND 196 Degradates were not identified/ quantified 000888 20 402582 03 Maneb ( 8: 1 Anaerobic water: Anaerobic sediment)

Lake water/ Loamy Sand Sediment ( 9 ppm) Parent never detected ND 275 EBIS 38.6% ( 3) 7.3% ( 275) EU EU Unknowns 001633 35 ( TLC)

1 Top values are half lives calculated, by the registrant, for parent EBDCs ( from CS2 data). Bottom values are halflives calculated, by EFED, for EBDCs complex ( from CO2 data) 2 These products are considered as transient species because they form early in the process, reach maximums and decline sharply. 3 Major= when maximum is > 10%; Minor= when maximum is < 10%. ND= Not Determined ( No CO2 data)

b. Chemical Identity and Physicochemical Properties ETU is a common degradate of the EBDC fungicides mancozeb, maneb, metiram and the no longer registered zineb. It is also used industrially as a cross linking agent in the manufacturing of synthetic rubbers. The chemical structure and physical chemical characteristics of ETU are listed in Table IV 4.

Considering the highest vapor pressure value alone( Table IV 4), ETU is expected to partition into the air from dry soil surfaces. However, its high water solubility/ relatively low Henry's law constant may render such partition unimportant because ETU forms from EBDCs only when water is present ( i. e. in wet soil or water bodies). A high water solubility is reported for ETU which makes it readily available for leaching in soils. Data collected from a microagroecosystem chamber indicate that small amounts of ethylene thiourea may volatilize from soil and plant surfaces8. Also, ETU was not detected in a US ambient air monitoring study of the USEPA designated 189 Hazardous Air 9 Kelly T. J. et al. 1994. Environ Sci. Technol 28: 378 87 10 Sue Xu. 2000. Environmental Fate of Ethylenethiourea, California Department of Pesticide Regulations, CA, USA; and IUPAC. 1977. Ethylenethiourea, Pure & Appl. Chem. 49, 675 689.

24 Pollutants9( 1). [( 1) The low K ow value for ETU, suggests that it will not significantly bio concentrated by aquatic organisms such as fish. Table IV 4. Nomenclature and physical chemical identity of ETU.

CAS 2 Imidazolidinethione Structure of ETU CAS Registry No. 96 45 7 PC Code Not applicable Molecular Weight 102.2 ( C3 H6 N2 S)

K OW 0.2 ( MRID 406510 01)

Vapor Pressure 1.28x10 3 and 6.59x10 6 atm.*

Henry's Law constant1 3.4X10 7 atm. m3 mole 1**

Water Solubility 20,000 ppm @ 20 oC and 90,000 ppm @ 60 oC * The first value is converted from a value of 9.728x10 1 mm Hg or torr; the second value was reported by Neely WB, Blau GE; 1985. Environmental Exposure from Chemicals. Boca Raton, FL: CRC Press pp. 31 ( converted from reported value of 5.01x10 3 mm Hg or torr). ** Estimated by using a fragment constant estimation method by Meylan W. M, Howard P. H. 1991. Env. Tox. Chem 10: 1283 93.

c. Fate Processes ETU is mainly produced from hydrolytic degradation of parent EBDCs following its application to soils and/ or after reaching water bodies by drift as part of the resultant EBDCs complex. In these systems, un identified species of the formed EBDCs complex partitions, in significant amounts, between the solid ( bound species) and liquid phases. ETU is further produced by hydrolytic reactions for the part left in pore water/ water bodies and by bio degradation for the significant part bound to soil/ sediment particles ( bound species).

Table IV 5 contains a summary of data obtained from guideline studies conducted on ETU as a test substance. Based on this data, ETU is expected to be highly susceptible to aerobic soil degradation, but stable to water hydrolysis/ direct photolysis as well as soil photolysis. While ETU is stable to laboratory direct photolysis in sterile water, aqueous photolysis ( indirect photolysis) was considered to be a major degradation pathway for ETU in natural water systems10. In the soil system, ETU lacks stability which can limit its availability for leaching but its high solubility/ mobility can cause it to leach, at low concentrations, into ground water or be transported in solution into surfacewater.

Table IV 5. Environmental fate data summary for ETU.

Parameter Value Source ( MRID )

Hydrolysis Stable @ 25 oC and pH 5, 7, and 9 404661 03 Photolysis Stable in pH 7 sterile buffered water 404661 02 1 4 days in natural waters ( indirect photolysis) 8 Parameter Value Source ( MRID )

11 Ross, R. D., Crosby, D. G. 1973. Photolysis of Ethylenethiourea. J. Agr. Food Chem., 21( 3): 335 337.

25 Stable on soil 404661 01 Aerobic Soil 2 Metabolism t1/ 2= 1.6 days in Collamer silt loam at 70% of the WHC 1 t1/ 2= 1.4 days in Oakville sand at 70% of the WHC t1/ 2= 3.2 days in Collamer silt loam at 40% of the WHC 451564 01 Anaerobic Soil; Aerobic Aquatic Metabolism; and Bio accumulation Factor : No acceptable studies.

Anaerobic Aquatic Metabolism t1/ 2= 149 days in a 1: 8 lake sediment: water ratio. t1/ 2= 29 35 days in a 48% moisture slurry. 001633 35 000888 20& 402582 03 Adsorption Coefficients ( L Kg 1) Sand Kd = 0.73 and KOC= 150 Silty Loam Kd= 1.14 and KOC= 57 Sandy Loam Kd= 0.67 and KOC= 42 Clay Loam Kd= 0.51 and KOC= 34 Clay Loam Kd = 5 and KOC= 54 Silty Clay Loam Kd= 9 and KOC= 276 Sandy Loam Kd= 2 and KOC= 783 Silty Loam Kd= 3 and KOC= 165 Clay Kd= 2 and KOC= 855 River Silt Kd= 29 and KOC= 464 002588 96 000971 58 Field Dissipation DT50 = 1 6 days or t ½ = 4 days in a fine sand soil DT50 = < 7 days in Keyport silt loam soil Accession No. 255229 000889 23 Accumulation in Fish Waived ( Octanol/ water coefficient= 0.5)

1 WHC= water holding capacity at a bar. 2 This same study may have been also submitted under MRID 452251 01.

i. Aqueous Solutions In a 30 day hydrolysis study, no detectable degradation of 14C ETU occurred in water at pH 5, 7, and 9 ( MRID 404661 03), therefore ETU is expected to be stable to hydrolysis in the environment. No significant photo degradation was observed for 14C ETU during a 30 day experiment indicating ETU is stable to aqueous photolysis ( MRID 404661 02). Similar results were reported for photolysis in de ionized water by Ross and Crosby11. Lack of photolysis was attributed to the fact that ETU does not absorb energy in the sunlight region as maximum absorbency lies at 240 nm.

In other photolysis experiments reported by Ross and Crosby., rapid loss of ETU occurred in the presence of dissolved oxygen and sensitizers such as acetone ( loss of 95% within 4 hours) or riboflavin. Identified degradation products included EU, glycine, and glycine sulfate with the sulfate quantitatively accounting for the sulfur from decomposed ETU. Furthermore, 50 90% of ETU decomposed within 3 to 24 days when mixed with boiled drainage water and exposed to sunlight compared to no effects occurred in the dark controls. The authors suggested that natural photosensitizers present in the drainage water may have played an important role in the observed photo degradation of ETU. As cited by the registrant, the same workers demonstrated later that exposure to light resulted in the formation of stable photooxidants ( tryptophane and tyrosine), which 12 Ross, R. D. 1974. Photooxidation in Agricultural Waters. Thesis, University of California, Davis, California, USA.

13 Engst, R. 1977. Pure & Appl. Chem. 49, p. 675.

14 Cruickshank, P. A. and Jarrow, H. C. 1973. J. Agric. Food Chem. 21 ( 3): 333 335.

26 were capable of degrading ETU in a dark soil environment12. It has been postulated that these amino acids are capable of oxidizing ETU through their ability to form hydroperoxides13. Cruickshank and Jarrow14 have confirmed that there are many sensitizers capable of catalyzing the photo oxidation of ETU.

ii. Soil Systems In the most recent 7 14 day supplemental aerobic soil study, Collamer silt loam ( 10% clay, pH 6.1, 2.09% OC, and 13 meq/ 100 g CEC) and Oakville sand ( 2% clay, pH 6.8, 1.22% OC, and 6 meq/ 100 g CEC) were treated with non radiolabeled ETU at a nominal application rate of 5 ppm ( MRID 452251 01). Calculated first order half lives were 1.6 or 3.2 days in the silt loam soil moistened to 70% or 40% of the WHC, respectively and 1.4 days in the sandy soil moistened to 70% of the WHC. This study was conducted with the objective of determining the kinetics for ETU degradation in aerobic soil. Un extracted residues and CO 2 were not measured and material balance was not determined. Ethyleneurea ( EU) was the only degradate monitored declining to < 1% after reaching a maximum of only 3 3.4% of the applied ETU at < 1 2 days . Results indicate that ETU is not persistent in the aerobic soil environment and that a slight decrease in the rate of bio degradation is expected with reduction of available soil moisture.

In a previous supplemental study 14C ETU, at 10 ppm, degraded with a half life of < 2 days in silt loam soil incubated in the dark at 23 ± 0.6 oC and 23% soil moisture content ( MRID 408387 01). At day 2, 56% of the applied radioactivity was extractable and was 20% as EU and 36% un known. By the end of this 93 day study, un identified/ un extractable 14C residue comprise 88% of the applied radioactivity and 14CO 2 totaled 40%. The interpretation of the results was complicated by not specifying purity of the test substance, incomplete characterization of residue, and the extremely variable material balance ( ranged from 66 131% of the applied radioactivity during the study).

ETU degradation pattern and rates on soil for irradiated and dark control samples were almost identical indicating that photo degradation is not expected to affect the environmental fate of ETU present on soil surfaces ( MRID 404661 01).

iii. Sediment/ Water Systems In an anaerobic aquatic soil study, 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 ( MRID 001633 35). Maneb was never identified and appear to have degraded by hydrolysis into the transient EBIS, two major degradates ETU and EU, and one minor un identified degradate. ETU was more prominent in the water phase reflecting its high solubility. In the total system, ETU degraded very slowly from a maximum concentration of 39% on day 3 with an estimated half life of 149 days. Therefore, ETU is expected to be reasonably stable under anaerobic aquatic conditions. Only TLC was used for quantification of degradates and assigned R f values varied from one plate to another. This causes 27 uncertainty on conclusions drawn from the results of the study.

Additionally, in a supplemental anaerobic aquatic metabolism study, ETU ( at 0.5 ppm level) degraded with a reported half life ranging from 29 to 35 days ( MRID 000888 20 and Addendum 402582 03). The study used a sediment slurry ( from a pond in Newtown, PA) incubated in the dark at pH 7 to 7.5 and 48% moisture with anaerobic conditions established by flushing with nitrogen. Although the study didn't fully investigate the fate of ETU in the aquatic soil/ water system, the results suggest that anaerobic conditions appear to be conductive for slowing down ETU decomposition in such systems compared to aerobic soil systems.

d. Mobility A 24 hour 14C ETU batch equilibrium study ( MRID 002588 96) indicates that " ETU residue containing significant quantities of ETU" was characterized by very high mobility in clay loam and sandy loam soils and was highly mobile in silt loam and sand soils ( Table IV 6). Initially, reported data indicate extensive degradation of ETU was found in the supernatant after the 24 hour adsorption period. The radioactivity in the supernatant consisted of ETU + HYD " hydantoin" ( 29 61%); EDA " ethylenediamine" + J. B " Jaffe's base" ( 7 22%); EU " ethyleneurea" ( 17%); and unidentified radioactivity ( 22 39%). Later, the registrant, claimed that the observed degradation products might have been " TLC artifacts" as in a separate but similar experiment, the registrant found that 86 100% of the radioactivity in the supernatant was ETU. EFED reviewer noted the possibility of degradation of ETU before conducting the experiment but concluded that it is clear that " ETU residues" included significant quantities of ETU and shown to be very mobile.

Table IV 6. Soil characteristics and the adsorption parameters of the soils used in 14C ETU adsorption/ desorption study.

Source Georgia Pennsylvania Georgia Mississippi Soil Textural Class Sand Silt Loam Sandy Loam Clay Loam Clay 4% 20% 12% 28%

pH ( water) 5.7 6.4 5.9 7.4 C. E. C ( meq/ 100 g) 4 10 6 13 Organic Carbon 0.5% 2.0% 1.6% 1.5%

Kad 0.73 1.14 0.67 0.51 1/ n 0.522 0.327 0.469 0.406 Koc 150 57 42 34 Mobility Class High Very High In a supplemental study ( Accession Number 2552 29), 14C ETU mobility was investigated by the TLC method in which determined R f values ranged from 0.61 to 1.0 ( Table IV 7). These values were taken to indicate medium to high mobility. Adsorption was positively correlated to organic carbon content of the soils. In one of the soils ( Hagerstown silty clay loam), ETU residues were immobile after six days of dry incubation, however, it became slightly mobile ( R f .0.2) when the residue were subjected to a wet dry cycle. In contrast, a previous experiment conducted with the same soils ( MRID 000658 59) showed parent maneb to be characterized with immobility to medium mobility ( Table IV 7). 15 Meylan W. M. et al 1992. Environ Sci Technol 26: 1560 67 28 Table IV 7. Soil characteristics and the adsorption parameters of the soils used in 14C ETU adsorption/ desorption study1.

Soil Name Celeryville muck Lakeland SL Barnes CL Hagerstown SiCL Norfolk SL Textural Class Muck soil Sandy Loam Clay Loam Silty Clay Loam Sandy Loam Clay Content Not determined 12% 34.4% 39.5% 11%

pH ( water) 5.0 6.4 7.4 6.8 5.1 Field Capacity 113.0% 8.5% 28.5 25.8% 6.5%

Organic Carbon 52.56% 0.52% 4.01% 1.45% 0.08%

Rf for ETU 0.61 1.00 0.83 0.96 0.96 Mobility Class for ETU Medium Very high Rf for maneb 1 0.00 0.10 0.17 0.42 Mobility Class for maneb Immobile Slight Medium 1 This study is a published article by Helling, C. S. and Thompson S. M. 1974. Azide and ethylenethiourea mobility in soils. Soil Science Society of America Proc. 38: 79 85.

In a supplemental column leaching study ( MRID 405883 01), 14C ETU was applied, to four soils at 10 ppm, aged for 24 hours, and resultant residues ( un identified) were leached for 1 to 25 days with 25" de ionized water. The radioactivity leaching profiles indicated that " 14C ETU residues" were very highly mobile in the sandy loam soil and were very mobile in the clay loam and the two silt loam soils. The leachate from the sandy loam soil columns contained 91% of the applied radioactivity while it contained 22 46% of the applied radioactivity in the other three soils. After leaching, the greatest concentration of radioactivity in the soil columns was in the top and was 5% in the sandy loam column and 18 55% in the other three soils. Many problems were associated with this experiment including: inadequate separation between ETU and its degradates in the TLC system used; ETU had degraded in all four soils prior to aging and was not detected in the two silt loam soils after aging; and most degradates were not characterized at any point in the experiment. Therefore, data presented preclude any conclusions on the identity of the leached materials as it can only be referred to as " 14CETU residues" .

Structural method, estimated a K oc value of 6.5 for ETU based on molecular connectivity indices15. This estimated value supports results of studies indicating very high mobility of ETU in the soil system. Therefore, studies indicating different conclusions may have been affected by degradation of ETU prior to and/ or during the aging process.

e. Field Dissipation In a supplemental field study, ETU was applied to Immokalee fine sand soil giving an extremely high zero concentration of 220 ppm ( Accession No 255229). Following application, ETU degraded with an estimated half life of 1 6 days. EFED calculated first order half life ( t ½ ) is equal to 4 days ( R2= 0.90) using reported data from this study. Patterns of formation and decline of the degradates were not addressed. 16 R. C. Rhodes 1977. Studies with manganese 14C Ethylene bis dithiocarbamate ( 14C Maneb) fungicide and 14C Ethylenethiourea ( 14C ETU) in plants, soil, and water. J. Agr. Food Chem., Vol. 25: 3, pp528 533.

29 In another supplemental field dissipation study, 14C ETU, 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 54" of rainfall ( MRID 000889 23). Half life of 1 to 4 weeks ( DT 50 . 16 days) was estimated from the " total radioactivity" remained in the whole 12" soil column. This half life was taken to represent the overall half life for ETU and its degradation products. Although no data was reported for ETU itself, it was claimed that specific analysis showed a half life of < 1 week for intact 14C ETU. Only 58% of the applied radioactivity was extractable after 1 week. TLC analysis of this extractable radioactivity showed that 79% ( i. e 46% of the total) was EU and the rest ( i. e 12% of the total) was polar material which remained at the origin of the TLC plates. The results of this study were also reported by Rhodes elsewhere16 f. Bio accumulation A waiver for the fish bio accumulation study was granted based on the determined octanol/ water partitioning coefficient of 0.2 ( MRID 406510 01); therefore ETU is not expected to accumulate in fish.

g. Transformation Products Tables IV 8 and IV 9 summarize data reported on various transformation products of ETU in submitted fate studies and in the literature. Most of these same transformation products were also reported to be present ( along transient species and ETU) in fate studies for various EBDCs ( test material is one of the EBDCs). This suggests that EBDCs degrade to ETU, through various transient species. Formed ETU appears to then degrade into various ETU transformation products and CO 2 .

Table IV 8. Identity/ structure of ETU transformation products.

Transformation Product Name CAS Number Structure Abbr.* Common IUPAC EU Ethyleneurea 2 Imidazolidone 107 15 3 HYD Hydantoine Or Glycolylurea 2,4( 3H, 5H) Imidazoledione Molecular formula/ mass: C3H4N2O2 ( 100.08) 461 72 3 J. B Jaffe's Base 1( 4,5 Dihydro 1H imidazol 2 yl) imidazolidin 2 thion 484 92 4 Transformation Product Name CAS Number Structure Abbr.* Common IUPAC 30 GLY Glycine Amino acetic acid 56 40 6 IMID 2 Imidazoline 2 Imidazoline 504 75 6 EDA ethylenediamine Not reported ( NR) ( NR)

Others: CO2, Un identified polar materials ( Polar), Un identified Bound species ( Bound)

* Abbreviated.

In submitted fate studies, identification/ quantification of various ETU transformation products were based on TLC without confirmation with other methods; one aerobic study was an exception. The results obtained from TLC were affected mainly by poor separation of the degradates. Additionally, many problems were cited for most of these studies including: use of test material with unknown purity, un determined or variable material balance, tracking of only selected degradates, and unidentification quantification of Bound species.

Data suggest that the major transformation products of ETU in important environmental compartments are EU, un identified Bound species and CO 2 . Other transformation products such as un identified polar compounds, HYD, J. B, GLY and IMID may form only in certain uncommon environmental conditions.

Table IV 9. Reported occurrences for ETU transformation products.

Study Type Aqueous UV photolysis Plants* Aerobic soil** Field Procedure( s) TLC/ IR/ MS TLC/ IR/ MS HPLC/ MS/ MS TLC only Time of Occurrence after a rapid degradation of ETU After 14 days EU after 2 days After 7 days Reference or MRID Rhodes ( 1) Rhodes ( 1) 452251 01 Rhodes ( 1); 000889 23 EU Major Intermediate to GLY*** 40% 3.4% 46% of residue HYD Major Intermediate to GLY*** NP ND Not present J. B Maximum of 16% 56% ND Not present GLY*** Major Final product Not present ND Not present IMID Not present ( NP) Minor amounts ND Not present Polar Compounds NP NP ND 12% of residue CO2 Not determined ( ND) ND ND Not determined Study Type Aqueous UV photolysis Plants* Aerobic soil** Field Procedure( s) TLC/ IR/ MS TLC/ IR/ MS HPLC/ MS/ MS TLC only Time of Occurrence after a rapid degradation of ETU After 14 days EU after 2 days After 7 days Reference or MRID Rhodes ( 1) Rhodes ( 1) 452251 01 Rhodes ( 1); 000889 23 31 Bound species Not Present ( no solids) ND ND 58% of residue * Plants*= Applied to tomato plants; only trace amounts of radioactivity constituted plant up take. ** In a supplemental aerobic soil study ( MRID 408387 01), Extractable radioactivity was 20% as EU and 36% un known at day 2. By the end of this 93 day study, un identified/ un extractable 14C residue comprise 88% of the applied radioactivity and 14CO2 totaled 40%; Procedure used for identification/ quantification was TLC only and the material balance was extremely variable. *** GLY***= Glycine and glycine sulfate with sulfur in sulfate accounting for structural ETU. ( 1) R. C. Rhodes 1977. Studies with manganese 14C Ethylene bis dithiocarbamate ( 14C Maneb) fungicide and 14C Ethylenethiourea ( 14C ETU) in plants, soil, and water. J. Agr. Food Chem., Vol. 25: 3, pp528 533. 17 Note: Parent rate ( kg/ ha)= 5.38 arrived at by multiplying the parent rate of 4.8 ( lb/ a) by 1.121 and ETU rate ( kg/ ha)= 0.52 arrived at by multiplying the parent rate of 5.38 ( kg/ ha) by 0.096 32 V. Water Resource Assessment a. Surface Water Modeling for Aquatic Exposure ETU is a common degradate of the EBDC fungicides metiram, mancozeb and maneb. For aquatic exposure, EFED based the preliminary aquatic exposure EECs for ETU on the results of screening models. The models are the Tier II linked, Pesticide Root Zone Model version 3.1.2 beta ( Carsel and others, 1997) and Exposure Analysis Modeling System version 2.98.04 ( Burns, 1997); referred to as PRZM/ EXAMS.

In modeling, ETU rate, was calculated by assuming very rapid and complete degradation of applied EBDCs to ETU. ETU rate was not based on the molar conversion of 38.5% but rather on the maximum conversion rate of 9.6% ( observed in the laboratory aerobic soil studies on concentration basis) for parent entering soil systems upon application and 23.6% ( observed in the laboratory aerobic/ anaerobic water/ sediment systems on concentration basis) for amounts entering aquatic systems by drift. These conversion rates were arrived at as a result of examination of fate and transport data of parent EBDCs which indicate that ETU is their major transformation product resulting from abiotic and biotic degradation processes in both field and laboratory studies. Reported laboratory data on degradation of EBDCs and the maximum ETU produced are summarized in Table V 1.

Table V 1. Maximum ETU produced in fate studies for parent EBDCs.

Type of Study Parent EBDCs Used as a Test Substance ( Number of Studies) Maximum ETU Formed As % Parent Equivalent As % ETU*

Aqueous Hydrolysis Maneb ( 1); Metiram ( 1) 93.0% 35.8%

Aerobic/ Anaerobic Aquatic Metiram ( 2); Maneb ( 1) 61.4% 23.6%

Aerobic Soil Metiram ( 4); Mancozeb ( 3); Maneb ( 3) 24.8% 09.6%

* % ETU= % Parent Equivalent multiplied by Molar ratio of Parent to ETU of 38.5%. For example, the maximum for hydrolysis studies= 93% x 0.385 = 35.8%.

Examination of data indicate that the maximum observed conversion of parent to ETU is expected to be the highest in water systems ( 35.8%) followed by water/ sediment systems ( 23.6%) and the lowest in aerobic soil systems ( 9.6%). Although these values represent the maximum found in the laboratory, higher or lower conversion rates may occur in the natural environment depending on the characteristics of the systems ( e. g. availability of moisture and biological activity). This is considered as an uncertainty along with the assumption that conversion to ETU occurs at application. In this respect, it is noted that the maximum ETU attained in the natural environment is a result of two major processes formation and degradation. This maximum is expected to occur shortly after the parent reaches the aquatic system by drift and much longer after foliar applied parent reaches the soil system.

In assigning the value for ETU application rate for modeling, EFED used the parent/ ETU conversion value of 9.6% for ETU expected to form ( from applied parent) in the soil system. This value ( equal to 0.52 kg a. i./ ha for apples17) was assigned to be the parent equivalent ETU rate. PRZM/ EXAMS 33 will use this value to calculate drift by multiplying 0.52 by 0.05 ( 5% drift). This ETU rate is accurate only for the soil system and needs to be corrected for the aquatic system. Therefore, a correction factor of 2.458 was used and was affected by changing the drift from 0.05 ( the default value) to 0.123. Changing the drift fraction by the stated factor will result in an exact account for the observed 23.6% parent/ ETU conversion rate in aquatic systems.

Inputs used for modeling include the fate and transport parameters determined for the EBDC metabolite/ degradate ETU ( Table V 2). As shown in Table V 2, ETU has an aerobic soil half life of about 3 days; in the absence of data, the aquatic aerobic metabolism half life was assumed to be about 6 days, or double the soil half life. The measured anaerobic aquatic metabolism half life, however, is substantially longer ( 149 days) possibly leading to the periodic detections in groundwater. It is highly soluble in water ( 20,000 ppm); highly vulnerable to indirect photolysis ( half life= 1 day), and moderately mobile ( 288 L/ kg). It also has a relatively high vapor pressure but high solubility reduces the possibility of losses from surface water due to volatilization.

Table V 2. PRZM/ EXAMS Input Parameters for ETU.

Input Parameter Value Reference Molecular Weight ( grams) 102.2 Product chemistry submission Vapor Pressure ( torr) 9.728e 1 Registrant data Aerobic Soil Metabolism Half life ( days) 3.14 Upper confidence bound on the mean for three soils ( MRID 452251 01)

Bacterial Bio lysis in the water column ( days) ( Aerobic Aquatic metabolism half life) 6.28 Aerobic soil t ½ x2: No aerobic aquatic metabolism study/ No significant hydrolysis ( Guidance) 1 Bacterial Bio lysis in benthic sediment ( days) ( Anaerobic Aquatic metabolism half life) 447 Only one value is available= 149 days ( MRID 001633 35); use 149x3= 447 days ( Guidance) 1 Application Rate Varies by crop and calculated from parent rate as described in Table V 3 below.

Application Method Aerial Product Label Depth of Incorporation ( inches) 0 Product Label Spray Drift ( fraction) 0.123 This value is increased from the default value of 0.05 by a factor of 2.458 2 Solubility ( mg/ L or ppm) 20,000 Product chemistry submission Koc ( L Kg 1) 288 Average for ten soils ( MRIDs 002588 96& 000971 58)

pH 7 Hydrolysis Half life ( days) Stable MRID 404661 03 Photolysis Half life( days) 1 This is the indirect photolysis half life reported for ETU; ETU is stable to direct photolysis ( MRID 404661 02)

1 Guidance for Chemistry and Management Practice Input Parameters For Use in Modeling the Environmental Fate and Transport of Pesticides, Version 2/ November 7, 2000.

2 This 2.458 correction factor was arrived at by dividing 23.6% ( conversion of parent to ETU in aquatic systems) by 9.6% ( conversion of parent to ETU in the soil systems). 34 As shown in Table V 3, the PRZM/ EXAMS farm pond simulation modeling was performed for 22 crop scenarios to cover the extensive use patterns for all EBDCs.

Table V 3. PRZM/ EXAMS Additional input parameters for various scenarios.

Scenario Parent EBDC Rate ETU Rate Application Date( dd/ mm) Number of Applications Interval ( Days) ( lbs/ a) kg/ ha 1 kg/ ha 2 Apples NC, Apples PA, and Apples OR ( Metiram, Mancozeb and Maneb) 4.80 5.38 0.52 07/ 03 20/ 03 15/ 03 04 7 Tomatoes FL, Tomatoes PA, and Tomatoes CA ( Mancozeb) 2.40 2.69 0.26 11/ 02 06/ 08 06/ 07 07 7 Peppers FL ( Maneb) 2.40 2.69 0.26 09/ 10 06 7 Sweet Corn FL, and Sweet Corn OR ( Maneb) 1.20 1.35 0.13 07/ 11 03/ 07 15 05 3 3 Potatoes ME, Potatoes ID ( Maneb) 1.60 1.79 0.17 07/ 07 15/ 07 10 5 Wheat TX, Wheat ND, and Wheat OR ( Mancozeb) 1.60 1.79 0.17 02/ 04 24/ 05 16/ 04 03 7 Cabbage FL ( Maneb) 1.60 1.79 0.17 10/ 10 01/ 15 06 7 Grapes CA ( Mancozeb and Maneb) 3.2 3.59 0.34 15/ 02 06 7 Almonds CA ( Maneb) 6.4 7.17 0.69 20/ 03 04 7 Onions CA ( Mancozeb and Maneb) 2.40 2.69 0.26 15/ 03 10 7 Turf FL ( Mancozeb and Maneb) 3 17.4 19.51 1.87 15/ 03 01 None Sugar beet CA, and Sugar beet ( Mancozeb and Maneb) 1.60 1.79 0.17 01/ 03 01/ 08 07 7 Peanuts NC ( Mancozeb) 1.80 2.02 0.19 21/ 03 07 5 1 Parent rate ( kg/ ha)= parent rate ( lbs a. i./ a) x 1.121. 2 ETU rate ( kg/ ha)= parent rate ( kg a. i./ ha) x 0.096. 3 Label didn't specify the number of applications, one application was assumed at a rate of 17.4 lbs a. i/ acre. However, PRZM/ EXAMS runs were also executed for three applications, 17.4 lbs a. i/ acre each applied at 5 and 7 days intervals.