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The information in this profile may be out-of-date. It was last revised in 1996. EXTOXNET no longer updates this information, but it may be useful as a reference or resource.

Please visit the National Pesticide Information Center (NPIC) to find updated pesticide fact sheets. If you don't find a fact sheet related to your question, feel free to call 1-800-858-7378. NPIC is open five days a week from 8:00am to 12:00pm Pacific Time.

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E X T O X N E T

Extension Toxicology Network

Pesticide Information Profiles

A Pesticide Information Project of Cooperative Extension Offices of Cornell University, Oregon State University, the University of Idaho, and the University of California at Davis and the Institute for Environmental Toxicology, Michigan State University. Major support and funding was provided by the USDA/Extension Service/National Agricultural Pesticide Impact Assessment Program.

EXTOXNET primary files maintained and archived at Oregon State University

Revised June 1996

Mancozeb

Trade and Other Names: Trade names include Dithane, Dithane-Ultra, Fore, Green-Daisen M, Karamate, Mancofol, Mancozeb, Mancozin, Manzate 200, Manzeb, Manzin Nemispor, Nemispot, Policar, Riozeb, and Zimaneb.

Regulatory Status: Mancozeb is a practically nontoxic ethylene bisdithiocarbamate in EPA toxicity class IV - practically nontoxic. It is registered as a General Use Pesticide (GUP). Labels for products containing mancozeb must bear the Signal Word CAUTION.

Chemical Class: ethylene(bis) dithiocarbamate

Introduction: Mancozeb is used to protect many fruit, vegetable, nut and field crops against a wide spectrum of fungal diseases, including potato blight, leaf spot, scab (on apples and pears), and rust (on roses). It is also used for seed treatment of cotton, potatoes, corn, safflower, sorghum, peanuts, tomatoes, flax, and cereal grains. Mancozeb is available as dusts, liquids, water dispersible granules, as wettable powders, and as ready-to-use formulations. It may be commonly found in combination with zineb and maneb.

Formulation: Mancozeb is available as dusts, liquids, water-dispersible granules, wettable powders, and ready-to-use formulations. It is commonly found in combination with zineb and maneb.

Toxicological Effects:

• Acute toxicity: Mancozeb is practially nontoxic via the oral route with reported oral LD50 of greater than 5000 mg/kg to greater than 11,200 mg/kg in rats [1,3]. Via the dermal route it is practically nontoxic as well, with reported dermal LD50 values of greater than 10,000 mg/kg in rats, and greater than 5000 mg/kg in rabbits [4]. It is a mild skin irritant and sensitizer, and a mild to moderate eye irritant in rabbits [4,32]. Workers with occupational exposure to mancozeb have developed sensitization rashes [1].
• Chronic toxicity: No toxicological effects were apparent in rats fed dietary doses of 5 mg/kg/day in a long-term study [1]. Impaired thyroid function was observed as lower iodine uptake after 24 months in dogs fed doses of 2.5 and 25 mg/kg/day of mancozeb, but not in those dogs fed 0.625 mg/kg/day [1]. A major toxicological concern in situations of chronic exposure is the generation of ethylenethiourea (ETU) in the course of mancozeb metabolism, and as a contaminant in mancozeb production [1,33]. ETU may also be produced when EBDCs are used on stored produce, or during cooking [9]. In addition to having the potential to cause goiter, a condition in which the thyroid gland is enlarged, this metabolite has produced birth defects and cancer in experimental animals [9].
• Reproductive effects: In a three-generation rat study with mancozeb at a dietary level of 50 mg/kg/day there was reduced fertility but no indication of embryotoxic effects [1,9]. In another study in which pregnant rats were exposed to mancozeb by inhalation, toxic effects on the pups were observed only at exposure levels (55 mg/m3) that were also toxic to the dams [1]. It is unlikely that mancozeb will produce reproductive effects in humans under normal circumstances.
• Teratogenic effects: No teratogenic effects were observed in a three-generation rat study with mancozeb at a dietary level of 50 mg/kg/day [1]. Developmental abnormalities of the body wall, central nervous system, eye, ear, and musculoskeletal system were observed in experimental rats which were given a very high dose of 1320 mg/kg of mancozeb on the 11th day of pregnancy [25]. Mancozeb was not teratogenic to rats when it was inhaled by pregnant females at airborne concentrations of 0.017 mg/L [32]. In pregnant rats fed 5 mg/kg/day, the lowest dose tested, developmental toxicity was observed in the form of delayed hardening of the bones of the skull in offspring [9]. In view of the conflicting evidence, the teratogenicity of mancozeb is not known.
• Mutagenic effects: Mancozeb was found to be mutagenic in one set of tests, while in another it did not cause mutations [9]. Mancozeb is thought to be similar to maneb, which was not mutagenic in the Ames Test [32]. Data regarding the mutagenicity are inconclusive but suggest that mancozeb is either not mutagenic or weakly mutagenic.
• Carcinogenic effects: No data are available regarding the carcinogenic effects of mancozeb. While studies of other EBDCs indicate they are not carcinogenic, ETU (a mancozeb metabolite), has caused cancer in experimental animals at high doses [9,10]. Thus, the carcinogenic potential of mancozeb is not currently known.
• Organ toxicity: The main target organ of mancozeb is the thyroid gland; the effects may be due to the metabolite ETU [9,10].

• Fate in humans and animals: Mancozeb is rapidly absorbed into the body from the gastrointestinal tract, distributed to various target organs, and almost completely excreted in 96 hours. ETU is the major mancozeb metabolite of toxicologic significance, with carbon disulfide as a minor metabolite [10].

Ecological Effects:

• Effects on birds: Mancozeb is slightly toxic to birds, with reported -day dietary LC50 values in bobwhite quail and mallard ducklings of greater than 10,000 ppm [32]. The 10-day dietary LC50 values of 6400 ppm and 3200 ppm are reported for mallard ducks and Japanese quail, respectively [4].

• Effects on aquatic organisms: Mancozeb is moderately to highly toxic to fish and aquatic organisms. Reported 48-hour LC50 are 9 mg/L in goldfish, 2.2 mg/L in rainbow trout, 5.2 mg/L in catfish, and 4.0 mg/L in carp [4]. The reported 72-hour LC50 for mancozeb in crayfish is greater than 40 mg/L; the 48-hour LC50 is 3.5 mg/L in tadpoles [32].
• Effects on other organisms: Mancozeb is not toxic to honeybees [4].

Environmental Fate:

• Breakdown in soil and groundwater: Mancozeb is of low soil persistence, with a reported field half-life of 1 to 7 days [20]. Mancozeb rapidly and spontaneously degrades to ETU in the presence of water and oxygen [10]. ETU may persist for longer, on the order of 5 to 10 weeks [20]. Because mancozeb is practically insoluble in water, it is unlikely to infiltrate groundwater [3]. Studies do indicate that ETU, a metabolite of mancozeb, has the potential to be mobile in soils [9]. However, ETU has been detected (at 0.016 mg/L) in only 1 out of 1295 drinking water wells tested [10].
• Breakdown in water: Mancozeb degrades in water with a half-life of 1 to 2 days in slightly acidic to slightly alkaline conditions [32].
• Breakdown in vegetation: When used as directed, mancozeb is not poisonous to plants [4].

Physical Properties:

• Appearance: Mancozeb is a grayish-yellow powder [3].
• Chemical Name: manganese ethylenebis(dithiocarbamate) (polymeric) [3]
• CAS Number: 8018-01-7
• Molecular Weight: 266.31
• Water Solubility: 6 mg/L [3]
• Solubility in Other Solvents: Practically insoluble in most organic solvents [3]
• Melting Point: Decomposes without melting @ 192 C [3]
• Vapor Pressure: Negligible @ 20 C [3]
• Partition Coefficient: Not Available
• Adsorption Coefficient: >2000 [20]

Exposure Guidelines:

• ADI: 0.03 mg/kg/day [33]
• MCL: Not Available
• RfD: 0.003 mg/kg/day [27]
• PEL: Not Available
• HA: Not Available
• TLV: Not Available

Basic Manufacturer:

DuPont Agricultural Products
Walker's Mill, Barley Mill Plaza
P.O.Box 80038
Wilmington, DE 19880-0038

• Phone: 800-441-7515
• Emergency: 800-441-3637
  

References:

References for the information in this PIP can be found in Reference List Number 4

DISCLAIMER: The information in this profile does not in any way replace or supersede the information on the pesticide product labeling or other regulatory requirements. Please refer to the pesticide product labeling.