Maleic Hydrazide is a crystalline solid. Molecular weight= 112.10; Freezing/Melting point=292℃ (decomposes at 260℃); also reported as .300℃. Hazard Identification (based on NFPA-704 M Rating System): Health 2, Flammability 1, Reactivity 0. Slightly soluble in cold water; more soluble in hot.
Maleic hydrazide is a colorless crystalline
solid. Odorless.
Maleic hydrazide is a crystalline solid
Growth regulator used to control the sprouting of potatoes and onions and to prevent sucker development on tobacco, fruits, ornamentals, vines, field crops and in forestry. Also used to control insects in warehouses, storerooms, empty sacks and in animal and poultry houses.
Maleic Hydrazide is used in plant growth regulator formulations.
Experimentally in horticulture and agriculture. To control suckering of tobacco. In the synthesis of pyridazine.
ChEBI: Maleic hydrazide is a pyridazinone.
Maleic hydrazide is slightly acidic. It is made by treating
maleic anhydride with hydrazine hydrate in alcohol.
Odorless white solid. Sinks in water.
3,6-Dihydroxypyridazine can be decomposed by oxidizing agents. 3,6-Dihydroxypyridazine can also be decomposed by strong acids. 3,6-Dihydroxypyridazine forms water-soluble alkali-metal and amine salts. 3,6-Dihydroxypyridazine is slightly acidic and may be titrated as a monobasic acid. Mild oxidation produces a compound which reacts instantly with dienes at -107° F to form crystalline derivatives. 3,6-Dihydroxypyridazine is slightly corrosive to iron and zinc. 3,6-Dihydroxypyridazine is incompatible with pesticides that are highly alkaline in reaction. In the presence of heavy metal and iron, zinc, calcium and magnesium ions, sparingly-soluble salts are formed.
Toxic by ingestion. Questionable carcinogen.
Inhalation of dust causes irritation of nose and throat. Contact with eyes or skin causes irritation. Ingestion has been observed to cause tremors and muscle spasms in test animals.
Special Hazards of Combustion Products: Toxic nitrogen oxides are produced.
Herbicide, Plant growth regulator, Fungicide: Banned for use in EU countries. Actively registered
for use in the U.S. Maleic hydrazide is a plant growth
regulator (sprout inhibitor) and herbicide that is registered
for use on tobacco, potatoes, onions, non-bearing citrus,
turf, utility and highway rights-of-way, airports, industrial
land, lawns, recreational areas, ornamental/shade trees and
ornamental plants. Most of the use of maleic hydrazide in
the U.S. is on tobacco.
BH DOCK KILLER®; BOS MH®;
BURTOLIN®; CHEMFORM®; DE-CUT®; DESPROUT
D REXEL-SUPER P®; EC 300®; FAIR 30®; FAIR
PLUS®; FAIR PS®; MAINTAIN 3®; MALEIN 30®;
MALAZIDE®; MH 30®; MH 40®; MH 36 BAYER®;
PO-SAN® (with 9H-Fluorene-9-carboxylic acid,
2-chloro-9-hydroxy-, methyl ester)®; REGULOX®;
REGULOX W®; REGULOX 50 W®; RETARD®;
ROYAL MH 30®; ROYAL SLO-GRO®; SLO-GRO®;
SPROUT-STOP®; STUNTMAN®; SUCKER-STUFF®;
SUPER DE-SPROUT®; SUPER SPROUT STOP®;
VONDALDHYDE®; VONDRAX®
Moderately toxic by
ingestion. Questionable carcinogen with
experimental tumorigenic data. Mutation
data reported. Can cause chronic liver
damage and acute central nervous system
effects. When heated to decomposition it
emits hghly toxic fumes of NOx See also
HYDRAZINE.
Maleic hydrazide is a pyridazine/
pyridazinone herbicide, plant growth regulator, and fungicide that is registered for use on tobacco, potatoes, onions,
nonbearing citrus, turf, utility and highway rights-of-way,
airports, industrial land, lawns, recreational areas, ornamental/
shade trees and ornamental plants. Most of the use
of maleic hydrazide in the United States is on tobacco.
Banned for use in EU countries. Actively registered for use
in the United States
Skin Contact: Flood all areas of body that have contacted the substance with water. Do not wait to remove contaminated clothing; do it under the water stream. Use soap to help assure removal. Isolate contaminated clothing when removed to prevent contact by others. Eye Contact: Remove any contact lenses at once. Flush eyes well with copious quantities of water or normal saline for at least 2023 min. Seek medical attention. Inhalation: Leave contaminated area immediately; breathe fresh air. Proper respiratory protection must be supplied to any rescuers. If coughing, difficult breathing, or any other symptoms develop, seek medical attention at once, even if symptoms develop many hours after exposure. Ingestion: If convulsions are not present, give a glass or two of water or milk to dilute the substance. Assure that the person’s airway is unobstructed and contact a hospital or poison center immediately for advice on whether or not to induce vomiting.
Mice fed up to 3 mg/kg for 320 ‘days showed no carcinogenic effect when sacrificed
at 2 years of age. Mice fed 0, 1000, 3200, and
10,000 ppm in the diet in 23 months showed no oncogenic
effect. Rats were fed diets providing doses of 0, 25,
500, or 1000 mg/kg. Occasional increases in tumor incidences
were seen, but as these were not consistent between
the two sexes and did not achieve statistical significance, they
are considered not attributable to maleic hydrazide.
Application of maleic hydrazide to the skin three times a
week up to a cumulative dose of 300mg was not carcinogenic
. Oral treatment of dogs and rats for 17–28
months resulted in no excess cancer in any tissue or
organs. Subcutaneous injections of maleic
hydrazide in newborn mice produced a very slight increase
in liver tumors, although this finding is generally
considered negative. A study in which maleic hydrazide
was given subcutaneously to mice (55 mg total over
49 weeks) showed no evidence of a carcinogenic response
was seen.
Soil. The half-life in soil was reported to be 2–8 weeks (Hartley and Kidd, 1987).
When maleic hydrazide was applied to muck, sand and clay at concentrations of 0.7 and
2.7, 1.0 and 3.75 and 0.85 and 3.4 ppm, 86 and 100, 87 and 100 and 47 and 67% degradation
yields were obtained, respectively (Hoffman et al., 1962).
Plant. Major plant metabolites include fumaric, succinic and maleic acids (Hartley
and Kidd, 1987).
Photolytic. In water, maleic hydrazide showed an absorption maximum at 300 nm
indicating direct photolysis should occur (Gore et al., 1971).
Chemical/Physical. Reacts with alkalies and amines forming water-soluble salts (Hartley
and Kidd, 1987). Decomposed by oxidizing acids releasing nitrogen (Worthing and
Hance, 1991). Decomposes at 260°C (Windholz et al., 1983) releasing toxic fumes of
nitrogen oxides (Sax and Lewis, 1987).
Color Code—Green: General storage may be used. Prior to working with this chemical you should be trained on its proper handling and storage. Store in a refrigerator or a cool, dry place.
UN3082 Environmentally hazardous substances,
liquid, n.o.s., Hazard class: 9; Labels: 9-Miscellaneous
hazardous material, Technical Name Required
Crystallise the hydrazide from water. Dry it at ~100o over P2O5. [Beilstein 24 III/IV 1186.]
Dust may form explosive mixture with
air. Incompatible with oxidizers (chlorates, nitrates, peroxides, permanganates, perchlorates, chlorine, bromine, fluorine, etc.); contact may cause fires or explosions. Keep
away from alkaline materials, strong bases, strong acids,
oxoacids, epoxides. Slightly corrosive to iron and zinc.
Maleic hydrazide forms water-soluble alkali-metal and
amine salts. It is slightly acidic and may be titrated as a
monobasic acid. Mild oxidation produces a compound
which reacts instantly with dienes at 277C/ 2 107F to
form crystalline derivatives. It is incompatible with pesticides that are highly alkaline in reaction. This chemical is
slightly corrosive to iron and zinc. In the presence of heavy
metal and iron, zinc, calcium, and magnesium ions,
sparingly soluble salts are formed.
Consult with environmental
regulatory agencies for guidance on acceptable disposal
practices. Generators of waste containing this contaminant
(≥100 kg/mo) must conform to EPA regulations governing
storage, transportation, treatment, and waste disposal.
In accordance with 40CFR165, follow recommendations
for the disposal of pesticides and pesticide containers.
Containers must be disposed of properly by following
package label directions or by contacting your local or
federal environmental control agency, or by contacting your
regional EPA office.
