Specification :

Mancozeb

Common name: mancozeb; mancozè be; manzeb
IUPAC name: manganese ethylenebis( dithiocarbamate) ( polymeric) complex with zinc salt
Chemical Abstracts name: [ [ 1, 2-ethanediylbis[ carbamodithioato] ] ( 2-) ] manganese mixture with [ [ 1, 2-ethanediylbis[ carbamodithioato] ] ( 2-) ] zinc
CAS RN: [ 8018-01-7] ( formerly [ 8065-67-6] ) ; [ 8018-01-7] is also applied to other mixed manganese and zinc ethylenebis( dithiocarbamate) complexes

PHYSICAL CHEMISTRY
Composition: The ISO definition is ' a complex of zinc and maneb containing 20% of manganese and 2.55% of zinc, the salt present being stated ( for instance mancozeb chloride) ' . Form: Greyish-yellow powder. M.p.: Decomposes at 192-204 º C. V.p.: Negligible at 20 º C. S.g./ density: 1.92. Solubility: In water 6.2 ppm ( pH 7.5, 25 ° C) . Insoluble in most organic solvents; dissolves in solutions of powerful chelating agents but cannot be recovered from them. Stability: Stable under normal, dry storage conditions. Slowly decomposed by heat and moisture. On hydrolysis ( 25 º C) , DT50 20 d ( pH 5) , 17 h ( pH 7) , 34 h ( pH 9) . Mancozeb a.i. is unstable and the tech. not isolated; the formulated product is produced in continuous process. F.p.: 137.8 º C ( Tag open cup) .

APPLICATIONS
Biochemistry: Non-specific thiol reactant, inhibiting respiration.
Mode of action: Fungicide with protective action.
Uses: Control of many fungal diseases ( e.g. blight, leaf spot, rust, downy mildew, scab, etc.) in field crops, fruit, nuts, vegetables, ornamentals, etc. Particular uses include control of early and late blights of potatoes and tomatoes ( at 1.36 kg a.i./ ha) ; Rhizoctonia solani and Streptomyces scabies on seed potatoes; leaf spot diseases on celery, cucurbits, beet, berries and currants; rusts on cereals, vegetables, roses, carnations, asparagus, beans, apples and plums ( at 1.6 kg/ ha) ; downy mildews on hops, vines, onions, leeks, lettuce, cucurbits, ornamentals and tobacco; Gloeodes pomigena, Glomerella cingulata, Microthyriella rubi and Physalospora obtusa on apples; scab on apples and pears ( at 2.4-3.6 kg/ ha) ; sigatoka disease ( Cercospora musae) in bananas; shot-hole of stone fruit; anthracnose of beans and cucurbits; damping-off diseases of vegetables; black leg of beet; needle cast in forestry; and many seed-borne diseases of cereals. Used for foliar application or as a seed treatment.
Formulation types: DP; DS; SC; WG; WP.

MAMMALIAN TOXICOLOGY
Oral: Acute oral LD50 for rats > 5000 mg/ kg.
Skin and eye: Acute percutaneous LD50 for rats > 10 000, rabbits > 5000 mg/ kg. Mild to moderate skin irritant; moderate eye irritant.
Inhalation: LC50 ( 4 h) for rats > 5.14 mg/ l.
ADI: 0.03 mg/ kg b.w. ( group ADI with maneb, metiram and zineb) ; ethylenethiourea 0.004 mg/ kg b.w.
Other: At very high levels, mancozeb has caused birth defects in test animals; ethylenethiourea, a trace contaminant and breakdown product of mancozeb, has caused thyroid effects, tumours and birth defects in laboratory animals.
Toxicity class: WHO ( a.i.) III ( Table 5) ; EPA ( formulation) IV
EC hazard: Xi; R37| R43

ECOTOXICOLOGY
Birds: In 10-day dietary studies, there were no mortalities in mallard ducks at 6400 mg/ kg daily, and in Japanese quail at 3200 mg/ kg daily.
Fish: LC50 ( 48 h) for goldfish 9.0, rainbow trout 2.2, catfish 5.2, carp 4.0 mg/ l.
Bees: LC50 0.193 mg/ bee.

ENVIRONMENTAL FATE
Plants: Extensively metabolised in plants, forming ethylenethiourea, ethylenethiuram monosulfide, ethylenethiuram disulfide, and sulfur as transitory intermediates. Terminal metabolites are natural products, especially those derived from glycine.
Soil/ Environment Rapidly degraded in the environment by hydrolysis, oxidation, photolysis, and metabolism. DT50 in soil c. 6-15 d. Koc > 2000.