Discover the Benefits of Maleic Hydrazide!

maleic hydrazide 123-33-1

Maleic hydrazide, with the CAS number 123-33-1, is a compound with the molecular formula C4H4N2O2 and a molecular weight of 112.09 g/mol. It is used as a plant growth regulator and herbicide, inhibiting nucleic acids and protein synthesis. It’s typically applied to the foliage of crops like potatoes, onions, garlic, and carrots to prevent sprouting during storage.

In terms of safety, maleic hydrazide has been found to have low acute toxicity by oral, dermal, and inhalation routes of exposure. However, it can cause skin and eye irritation, and there are precautionary measures recommended for handling it, such as wearing protective gloves and ensuring proper ventilation.

Regarding environmental impact, the U.S. EPA has included maleic hydrazide in the IRIS database, indicating that it has undergone a comprehensive review of toxicity data. The oral Reference Dose (RfD) suggests that there is an assumption of thresholds for certain toxic effects, and the substance is not evaluated for carcinogenicity. Nevertheless, there have been discussions about its potential mutagenicity and carcinogenicity in cell cultures and animals, though no evidence of human carcinogenicity has been found despite population exposure in manufacturing, agriculture, and the food chain.

For medical research applications, maleic hydrazide is available for purchase with a purity of over 99.0% (T) as determined by HPLC, and it is sold in various quantities for laboratory use. It’s important to note that the latest information on storage conditions and safety data sheets should be consulted when handling this chemical.

Maleic hydrazide is a water-insoluble pyridazinone compound with diverse applications. It serves as both a herbicide and a plant growth regulator, making it valuable in agricultural practices.

Additionally, maleic hydrazide is utilized to control the unwanted sprouting or suckering of tobacco plants.

maleic hydrazide Properties

Melting point 299-301 °C (dec.)(lit.)

Boiling point 209.98°C (rough estimate)

Density 1,6 g/cm3

Refractive index 1.4610 (estimate)

Flash point 300°C

Storage conditions Inert atmosphere,Room Temperature

Solubility 510 mg/l in 4 water

Acidity coefficient(pKa) 9.01±0.20(Predicted)

Color White crystals

Odor (Odor) Odorless

Water solubility 6 g/L

Merck 14,5705

BRN 112223

Chemical Properties

Pure product is white crystalline solid. m.p.296～298℃, relative density 1.60 (25℃), flash point 300℃, non-volatile. solubility at 25℃ is: dimethylformamide 2.4%, acetone <1%, xylene <1%, ethanol <0.1%, water 0.6%. Stable nature, can be decomposed to release nitrogen when encountering strong acid, slightly corrosive to iron. Purity of the original drug>97%, m.p.>292 ℃, relative density 1.60. Its triethanolamine salt solubility in water is 70%, potassium salt 10%, sodium salt 20%.

Uses

Storage and Transportation: It is also used in the agricultural industry as a sprout inhibitor for stored potatoes to prevent premature sprouting.

Mode of Action: Maleic hydrazide disrupts the growth process in plants by inhibiting the synthesis of nucleic acids and proteins, ultimately leading to the suppression of cell division and growth.

Maleic hydrazide is a selective herbicide and temporary plant growth inhibitor.Maleic hydrazide has herbicidal properties and can be used to control weeds in turf grass and other agricultural settings.

Plant growth regulator. Inhaled through the foliage or roots, conducted by the xylem and phloem, inhibit cell division and inhibit plant growth. 0.1% ~ 0.05% solution can prevent grass and lawn, orchard and water weeds; 0.025% solution to inhibit the germination of onions and potatoes during the storage period; 0.1% ~ 0.05% solution to inhibit and delay the growth of side shoots of tobacco and to keep the citrus seedlings free from frost damage.

It enters the plant through the leaf cuticle, reduces photosynthesis, osmotic pressure and evapotranspiration, and strongly inhibits shoot growth. It is used to prevent germination of potatoes, onions, garlic and radishes during storage, and has the effect of inhibiting crop growth and prolonging flowering, and can also be used for weed control in non-cultivated land. The product’s reciprocal isomerization is 3,6-Dihydroxypyridazine (3,6-Dihydroxypyridazine). It is an intermediate of the sulfonamide drug sulfamethoxazole.

Plant growth regulator. Inhaled through the foliage or roots, conducted by xylem and phloem, inhibit cell division and inhibit plant growth.0.1%～0.05% solution can prevent grass and weeds in lawn, orchard and waterside; 0.025% solution can inhibit the germination of onion and potato during the storage period; 0.1%～0.05% solution can inhibit and delay the growth of side shoots of tobacco and keep the citrus seedling free from frost damage.

The agent can enter the plant through the leaf cuticle, reduce photosynthesis, osmotic pressure and evapotranspiration, and can strongly inhibit the growth of buds. Used to prevent sprouting during storage of potatoes, onions, garlic and radishes, and has the effect of inhibiting crop growth and prolonging flowering, and can also be used for weed control in non-cultivated areas.

Temporary plant growth inhibitor. Selective herbicide (removes matangrass). Prevents sprouting of onions, potatoes and carrots in storage. Horticultural and agricultural experiments. Maleic hydrazide is a selective herbicide and temporary plant growth inhibitor. The agent enters the plant through the leaf cuticle, reduces photosynthesis, osmotic pressure and evapotranspiration, and strongly inhibits the growth of shoots. It is used to prevent germination of potatoes, onions, garlic and radishes during storage, and has the effect of inhibiting crop growth and prolonging flowering, and can also be used for weed control in non-cultivated land. The product’s reciprocal isomerization is 3,6-Dihydroxypyridazine (3,6-Dihydroxypyridazine). It is an intermediate of the sulfonamide drug sulfamethoxazole.

Maleic hydrazide is a chemical compound that belongs to the group of hydrazides. Maleic hydrazide is used as a herbicide and plant growth regulator. Maleic hydrazide enters cells by diffusion and reacts with nucleophilic groups in the nucleus, thereby inhibiting DNA synthesis and causing mutations. Biological studies have shown that maleic hydrazide is genotoxic, meaning that it destroys genetic information within the cell, leading to mutations. Maleic hydrazide has also been shown to cause genotoxic effects in model systems. It also inhibits enzyme activities in plants, such as nitrate reductase, urease, or catalase activity.

Herbicide, plant growth regulator, fungicide: Banned in EU countries. Maleic hydrazide is a plant growth regulator (germination inhibitor) and herbicide registered for use on tobacco, potatoes, onions, non-bearing citrus, turf, utility and highway rights-of-way, airports, industrial sites, lawns, recreational areas, ornamental/shade trees and ornamentals.

Most of the use of maleic hydrazide in the U.S. is on tobacco.

Production method

It is obtained by reacting maleic anhydride with hydrazine hydrate. Put water and 40% hydrazine hydrate in the reaction pot, add 30% hydrochloric acid dropwise under stirring and cooling, the temperature is controlled below 20℃, to pH 6.2-6.4, put maleic anhydride, slowly raise the temperature to 106-110℃, reflux for 2h, reduce the temperature to 5℃, dump filtration, the filter cake is washed with iced water to pH 4.8-5.1, drying, to get maleic dihydrazide, the yield of 97%.

Produced by reacting butylene dihydrazide (or butadiene dihydrazide) with hydrazine sulfate at 35-56℃.

Produced by reacting butylene dianhydride (or butadienedioic acid) with hydrazine sulfate at 35-56°C.

Produced by reacting maleic anhydride with hydrazine hydrate. Put water and 40% hydrazine hydrate in the reaction pot, add 30% hydrochloric acid dropwise under stirring and cooling, the temperature is controlled below 20 ℃, to pH 6.2-6.4, put in maleic anhydride, slowly raise the temperature to 106-110 ℃, reflux for 2h, reduce the temperature to 5 ℃, dump filtration, the cake is washed with iced water to pH 4.8-5.1, drying, and get maleic hydrazide, the yield of 97%.

Category

Toxicity

Acute oral LD501400mg/kg in rats, 6950mg/kg for its sodium salt, 2340mg/kg for its diethanol salt. no irritation. No symptoms of poisoning were observed when rats were fed with feed containing 5% of the original drug for 2 years, and no teratogenicity, carcinogenicity or mutagenicity was observed. Low toxicity to fish, perch LC5075mg/L. Non-toxic to bees.

Poisoning

Acute toxicity

Oral – Rat LD50: 3000 mg/kg

Flammability Hazardous Characteristics

Combustion produces toxic nitrogen oxide gas

Storage and transportation characteristics

Ventilated, cold and dry; separate from foodstuffs.

Extinguishing agents

Dry powder, foam, sand

First Aid Measures for Pesticide Poisoning

First aid treatment

No specific antidote. If accidentally taken, induce vomiting first, then treat symptomatically.

Carcinogenicity

Mice fed 3 mg/kg for 320 ‘days did not show carcinogenic effects when sacrificed at 2 years of age. Mice fed 0, 1000, 3200 and 10,000 ppm in the diet for 23 months showed no carcinogenic effects. Rats were fed doses of 0, 25, 500 or 1000 mg/kg.

There was an occasional increase in tumour incidence, but since the incidence in male and female rats was not uniform and did not reach statistical significance, this was not considered to be related to maleic hydrazide.

Application of maleic hydrazide to the skin three times a week at a cumulative dose not exceeding 300 mg was not carcinogenic. Oral treatment of dogs and rats over a period of 17-28 months did not reveal excess cancer in any tissue or organ.

Subcutaneous injection of maleic hydrazide into neonatal mice resulted in a very slight increase in liver tumours, although this result is usually considered negative.

A study of subcutaneous injections of maleic hydrazide in mice (55 mg over 49 weeks) showed no evidence of a carcinogenic response.

Safety Information

Moderately toxic by ingestion. Questionable carcinogen with experimental tumorigenic data. Mutation data reported. Can cause chronic liver damage and acute central nervous system effects. Releases highly toxic nitrogen oxide fumes when heated to decomposition.

Hazardous material symbol Xi,Xn

Hazard Category Code 36/37/38-40-R40-R36/37/38-68

Safety Instructions 26-36-45-36/37/39-S45-S36/37/39-S26

Dangerous Goods Transportation Number UN 3077 9/PG 3

WGK Germany 2

RTECS No. UR5950000

Auto-ignition temperature 707 °F

TSCA Yes

Customs code 29339990

Hazardous Substances Data 123-33-1(Hazardous Substances Data)

Toxicity LD50 orally in rats: 3800-6800 mg/kg; dermally in rabbits: >4000 mg/kg (Ben-Dyke)

Reactivity Profile

3,6-Dihydroxypyridazine is decomposed by oxidising agents.3,6-Dihydroxypyridazine is also decomposed by strong acids.3,6-Dihydroxypyridazine forms water-soluble alkali metal salts and amine salts.

3,6-Dihydroxypyridazine is slightly acidic and titratable to mono acids. Mild oxidation produces compounds that react immediately with diolefins to form crystalline derivatives at temperatures up to -107° F. 3,6-Dihydroxypyridazine is slightly corrosive to iron and zinc.

3,6-Dihydroxypyridazine is incompatible with insecticides that react with strong bases. In the presence of heavy metals and iron, zinc, calcium and magnesium ions, dilute soluble salts are formed.

Environmental Fate

Soil. The half-life in soil has been 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).

Plants. Major plant metabolites include fumaric acid, succinic acid and maleic acid (Hartley and Kidd, 1987).

Photolysis. In water, maleic hydrazide shows an absorption maximum at 300 nm, indicating direct photolysis (Gore et al., 1971).

Chemical/Physical. Reacts with bases and amines to form water-soluble salts (Hartley and Kidd, 1987). Oxidising acids decompose to release nitrogen (Worthing and Hance, 1991). Decomposes at 260°C (Windholz et al., 1983), releasing toxic nitrogen oxide fumes (Sax and Lewis, 1987).

storage

Colour code – GREEN: May be used for general storage. Receive training in the proper handling and storage of this chemical prior to use. Store in refrigerator or cool dry place.

Purification Methods

Crystallise the hydrazide from water. Dry it at ~100o over P2O5. [Beilstein 24 III/IV 1186.]

Incompatibilities

Dust may form explosive mixtures with air. Incompatible with oxidising agents (chlorates, nitrates, peroxides, permanganates, perchlorates, chlorine, bromine, fluorine, etc.); contact may cause fire or explosion.

Keep away from alkalis, strong bases, strong acids, oxidising acids and epoxides. Slightly corrosive to iron and zinc. Maleic hydrazide forms water-soluble alkali metal and amine salts. It is weakly acidic and can be titrated to monobasic acids.

Mild oxidation produces a compound which reacts instantaneously with dienes at 277C/2107F to form crystalline derivatives. It is incompatible with insecticides that react with strong bases. This chemical is slightly corrosive to iron and zinc.

In the presence of heavy metals and iron, zinc, calcium and magnesium ions, dilute soluble salts are formed.

Waste Disposal

Consult the environmental regulator for acceptable disposal methods.

Waste generators containing this contaminant (≥100 kg/month) must comply with EPA regulations for storage, transport, handling, and waste disposal. Follow pesticide and pesticide container disposal recommendations per 40CFR165. Containers must be disposed of properly according to the instructions on the package label or by contacting the local or federal environmental control agency or the regional EPA office.