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Maneb - Chemical Fact Sheet 10/88

EPA Pesticide FactSheet
Name of Chemical:  MANEB
Reason for Issuance: REGISTRATION STANDARD
Date Issued:  October 3, 1988
Fact Sheet Number:  182

                         1.  DESCRIPTION OF CHEMICAL
Chemical Name:  Manganese ethylene bisdithiocarbamate
ANSI Common Name:  Maneb
Principal Trade Names:  Dithane M-22, Manzate
EPA (Shaughnessy) Code:  014505
Chemical Abstracts Service (CAS) Number:  12427-38-2
Year of Initial Registration:  Late 1940's
Pesticide Type:  Fungicide
Chemical Family:  Ethylene bisdithiocarbamate (EBDC)
U.S. and Foreign Producers:  Pennwalt

                       2.  USE PATTERNS AND FORMULATIONS

Registered uses:  Terrestrial food crop (fruits, vegetables, seed
                  crops, nuts, flax, and grains); terrestrial non-food
                  crop (ornamentals, lawns, turf); greenhouse food
                  (tomatoes, rhubarb) and non-food crop (ornamentals)

Predominant uses:  Apples, potatoes, tomatoes and sweet corn

Pests controlled:  Foliar fungal diseases of selected fruit, nut,
                   vegetable, grain, field and ornamental (including
                   turf) crops.

Types of Formulations:  Technical, formulation intermediate, dust,
                        granular, wettable powder, wettable powder/
                        dust, flowable concentrate, and ready-to-use.

Types and Method of  Foliar application to vegetable crops and
   Application:      apples by aerial equipment or ground equipment.
                     Foliar treatment of tobacco or vegetable seed
                     beds, application of sprays or dusts might
                     be by means of hand held compressed air sprayers
                     or dusting equipment.  Potato and tomato foliage
                     may be treated by means of solid set, wheel
                     move, or center pivot sprinkler irrigation
                     equipment.

Application Rates:   Terrestrial food crop:  0.01 - 8.4 lb. ai/A
                     Terrestrial nonfood crop:  0.8 - 3.2 lb. ai/A
                     Greenhouse food crop:  1.1 - 2.4 lb. ai/100 gal.
                     Greenhouse nonfood crop:  0.8 - 2.4 lb. ai/100 gal.

                             3.  SCIENCE FINDINGS

Chemical Characteristics

  Physical state:  Powder
  Color:  Yellow
  Odor:  faint
  Molecular Formula:  (C4H6MnN2S4)x)x

Toxicology Characteristics

  Acute Oral:  LD50 = 4,400 mg/kg bw (rat) (Toxicity Category III)

  Acute Dermal:  LD50 > 2 gm/kg bw (rabbit) (Toxicity Category III)

  Acute Inhalation:  LC50 > 2.22 plus or minus 0.26 mg/l (rat);
                     (Toxicity Category III)

  Primary Dermal Irritation:  Non-irritating (rabbit)(Toxicity Category
                              IV)

  Primary Eye Irritation:  Severe eye irritant (rabbit)(Toxicity
                           Category I)

  Dermal Sensitization:  Sensitizer (guinea pig)

  Major Routes of Exposure:  Oral, dermal and inhalation

  Subchronic Toxicity:  No observed effect level (NOEL) = 100 ppm,
                        LEL (increase in thyroid weight in males) = 300
                        ppm (Monkeys).

  Oncogenicity:  Studies required

  Chronic feeding:  Studies required

  Metabolism:  Studies in rats indicate that maneb is hydrolyzed,
               readily absorbed and excreted in the urine and feces.
               The major metabolite is ETU.

  Reproduction:  Study required

  Teratogenicity & Developmental Toxicity:  Studies required

  Mutagenicity:  Mutagenicity testing showed that maneb was positive
                 for inducing chromosomal damage in an in vitro SCE
                 (sister chromatid exchange) assay with metabolic
                 activation.  Evidence showed that maneb is most likely
                 not an initiating agent and the evidence on promotion
                 capability was negative.  Additional data are required
                 before the unscheduled DNA synthesis (UDS) assay can
                 be upgraded to acceptable status.  The following
                 studies were negative: Sister chromatid exchange in
                 CHO cells in the absence of a metabolic activation and
                 Host mediated assay in mice.

Physiological an Biochemical Characteristics

  Metabolism and Persistence in Plants and Animals:

  Metabolism of maneb is not completely understood.  Additional
  data are being required in plants and livestock.  ETU is a
  major metabolite of concern.

Environmental Characteristics

  Maneb degrades to ETU and other transient degradates in water and
soil.  ETU is stable in water at pH S-9 and under sunlight and the
degradation of ETU on soil is not enhanced by sunlight radiation.

  Maneb degrades very rapidly under anaerobic aquatic soil conditions
but ETU is relatively stable under these conditions.

  ETU is stable in water at pH 5-9 and under sunlight and the
degradation of ETU on soil is not enhanced by sunlight radiation.  ETU
is the degradate of major environmental concern.  There are indications
that ETU may leach and enter groundwater.  However, additional data are
required to complete the groundwater assessment.

Ecological Characteristics

  Maneb has been found to be practically nontoxic to birds and
mammals.

  Avian dietary toxicity:  LC50 > 9,000 ppm (bobwhite)

  The toxicity of a 80 product to warmwater fish is highly toxic.

                            TOLERANCE ASSESSMENT

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CHECK EBDC CHEMICAL PROFILE FOR REGULATORY AND TOLERANCE ASSESSMENT UPDATE
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  Tolerances, expressed as zinc ethylene bisdithiocarbamate, have been
established for residues of maneb in a variety of raw agricultural
commodities (40 CR 180.110).

  The toxicology data for maneb are insufficient to determine an
Acceptable Daily Intake (ADI) or whether the toxicity observed in the
studies is due to maneb or ETU.  A subchronic study has been used to
calculate a Provisional ADI (PADI).  Because a subchronic study was
used, an uncertainty factor of 1000 was employed.  The PADI for maneb is
0.0005 mg/kg/day based on the six month feeding study with a NOEL of 5
mg/kg/day.

  The theoretical maximum residue contribution (TMC), based on the
assumption that 100 percent of each crop is treated and contains
residues at the tolerance level, is 0.030 or approximately 600 percent
of the PADI.  Based on a more realistic dietary assessment, using
anticipated field residues and estimate of percent crop treated, the
estimated average consumption for the U.S. population is 0.0036
mg/kg/day or 70 perecent of the PADI.

                     4.  SUMMARY OF REGULATORY POSITIONS

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CHECK EBDC CHEMICAL PROFILE FOR REGULATORY AND TOLERANCE ASSESSMENT UPDATE
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  The Agency has initiated a Special Review for maneb along with the
other EBDC's in June 1987 because of concern about the oncogenic risk to
consumers from dietary exposure to ETU from food treated with these
pesticides, and the risks of teratogenicity and adverse thyroid effects
to applicators and mixer/loaders from exposure to ETU.

  ETU has been classified as a B2 oncogen (probable human
  carcinogen) .

  The Agency will not consider establishment of new food use tolerances
  for maneb because the current residue chemistry and toxicology data
  are not sufficient to assess existing tolerances and the toxicology
  data base is insufficient to determine an ADI and also does not
  allow a decision as to whether observed toxicity is due to maneb or
  ETU.

  The Agency will consider the need for establishment of tolerances for
  ETU and any intermediate metabolites when & data are sufficient to
  permit such decisions.

  The Agency will not establish any food|feed additive regulations
  pursuant to Section 409 of the Federal Food, Drug and Cosmetic Act
  (FFDCA) and is deferring action on previously established food|feed
  additive regulations.

  Protective clothing labeling for maneb products, as specified as a
  result of the 1982 Decision Document should be updated.

  The Agency is requiring reentry data for maneb.  In order to remain in
  compliance with FIFRA, an interim 24-hour reentry interval requirement
  must be placed on the label of all maneb end-use products registered
  for agricultural uses, until the required data are submitted and
  evaluated and any change in this reentry interval is announced.

  The Agency has screened and reviewed the environmental fate data to
  determine if maneb/ETU and/or its degradate(s) have the potential to
  leach in to ground water.  The Agency has decided that a small-scale
  retrospective groundwater monitoring study is required to further
  define the extent of the ground water problem.

  While the data gaps are being filled, currently registered
  manufacturing-use products (MP's) and end-use products (EP's)
  containing maneb as the sole active ingredient may be sold,
  distributed, formulated and used, subject to the terms and conditions
  specified in this Standard.  However, new uses will not be registered.
  Registrants must provide or agree to develop additional data, as
  specified in the Data Appendices of the Registration Standard, in
  order to maintain existing registrations.

                              LABELING REQUIREMENTS

  All maneb products must bear appropriate labeling as specified in
  40 CFR 156.10.  Appendix II of the Registration Standard contains
  information on labeling.

The following are the major labeling specification:

  Environmental hazard statement
  Protective clothing requirements
  Preharvest interval
  Worker safety rules
  Grazing restrictions for almonds, apples, beans, corn, peanuts,
  potato, sugar beets, ornamental grasses, ornamental turf.

                             5.  SUMMARY OF DATA GAPS

Product Chemistry All

Toxicology

Subchronic dermal (21-Day)
Subchronic inhalation (90-Day)
Chronic toxicity (rodent and nonrodent)
Oncogenicity (rat and mouse)
Teratology (rabbit an rat)
Reproduction (rat)
Mutagenicity (gene mutation) (other genotoxic effects)
Dermal absorption

Residue Chemistry

Nature cf the Residue in Plants and Livestock
Analytical Methods
Magnitude o Residue for Variety of Commodities

Environmental Fate

Hydrolysis
Photodegradation studies in water and soil
Aerobic soil studies
Aerobic aquatic
Leaching and absorption/desorption
Aquatic (sediment)

Dissipation Soil Studies
Small-scale retrospective monitoring study
Fish accumulation

Reentry Protection

Reentry Studies on Foliar and Soil Dissipation

Wildlife and Aquatic Organisms

Avian oral toxicity
Avian dietary toxicity
Avian reproduction
Freshwater fish toxicity
Acute freshwater invertebrates
Estuarine and marine organism toxicity
Fish early life stage and invertebrate life-cycle
Aquatic organism accumulation

ETU Data Requirements

Toxicology

Chronic (rodent and non-rodent)
Reproduction

Environmental Fate

Aerobic and anaerobic soil metabolism
Aerobic aquatic
Lab volatility
Degradation (soil)
Aquatic (sediment)
Degradation (soil long-term)
Fish accumulation

                            6.  CONTACT PERSON AT EPA

Lois A. Rossi
Product Manager (21)
Fungicide-Herbicide Branch
Registration Division (TS-767C)
Office of Pesticide Programs
Environmental Protection Agency
401 M St., SW
Washington, D.C.  20460

Office location and phone number:
Room 227, Crystal Mall #2
1921 Jefferson Davis Highway
Arlington, VA
(703) 557-1900

DISCLAIMER:  The information in this Pesticide Fact Sheet is a summary
only and may not be used to satisfy data requirements for pesticide
registration an reregistration.  The complete Registration Standard for
the pesticide may be obtained from the National Technical Information
Service.  Contact the Product Manager listed above for further
information.