Supplier Related Products Identification Chemical Properties Safety Data Questions And Answer(Q&A) Raw materials And Preparation Products Hazard Information Material Safety Data Sheet(MSDS) Spectrum Detail Well-known Reagent Company Product Information
WebSite >  CAS DataBase List  > 108-31-6


Supplier Related Products Identification Chemical Properties Safety Data Questions And Answer(Q&A) Raw materials And Preparation Products Hazard Information Material Safety Data Sheet(MSDS) Spectrum Detail Well-known Reagent Company Product Information

Product Image


Maleic anhydride
cis-Butenedioic anhydrides Maleic anhydride
Anhydrid kyseliny maleinove
Lytron 820
Molecular Formula
MDL Number
Molecular Weight
MOL File

Chemical Properties

Maleic anhydride is colorless needles, white lumps, or pellets. Irritating, choking odor.
White solid
Melting point 
51-56 °C (lit.)
51-56 °C(lit.)

Boiling point 
200 °C (lit.)
200 °C(lit.)

vapor density 
3.4 (vs air)

vapor pressure 
0.16 mm Hg ( 20 °C)

refractive index 
1.4688 (estimate)
218 °F

storage temp. 
Store at RT.

Stable. Combustible. Incompatible with water, strong oxidizing agents, alkali metals, strong bases, amines, most common metals, polymerization catalysts and accelerators.
0.8 (550g/l, H2O, 20℃)Hydrolysis
explosive limit
Water Solubility 
79 g/100 mL (25 ºC)
Moisture Sensitive
Henry's Law Constant
(atm?m3/mol): Not applicable - reacts with water
Exposure limits
NIOSH REL: TWA 1 ppm (0.25 mg/m3), IDLH 10 ppm; OSHA PEL: TWA 0.25 ppm; ACGIH TLV: TWA 0.25 ppm with an intended change of 0.1 ppm.
CAS DataBase Reference
108-31-6(CAS DataBase Reference)
NIST Chemistry Reference
EPA Substance Registry System
108-31-6(EPA Substance)

Safety Data

Hazard Codes 
Risk Statements 
R22:Harmful if swallowed.
R34:Causes burns.
R42/43:May cause sensitization by inhalation and skin contact .
Safety Statements 
S22:Do not breathe dust .
S26:In case of contact with eyes, rinse immediately with plenty of water and seek medical advice .
S36/37/39:Wear suitable protective clothing, gloves and eye/face protection .
S45:In case of accident or if you feel unwell, seek medical advice immediately (show label where possible) .
UN 2215 8/PG 3

WGK Germany 


Autoignition Temperature
870 °F
HS Code 
Safety Profile
Poison by ingestion and intraperitoneal routes. Moderately toxic by skin contact. A corrosive irritant to eyes, skin, and mucous membranes. Can cause pulmonary edema. Questionable carcinogen with experimental tumorigenic data. Mutation data reported. A pesticide. Combustible when exposed to heat or flame; can react vigorously on contact with oxidizing materials. Explosive in the form of vapor when exposed to heat or flame. Reacts with water or steam to produce heat. Violent reaction with bases (e.g., sodmm hydroxide, potassium hydroxide, calcium hydroxide), dkah metals (e.g., sodium, potassium), amines (e.g., dimethylamine, triethylamine), lithium, pyridine. To fight fire, use alcohol foam. Incompatible with cations. When heated to decomposition (above 150℃) it emits acrid smoke and irritating fumes. See also ANHYDRIDES.
Hazardous Substances Data
108-31-6(Hazardous Substances Data)
LD50 orally in Rabbit: 1090 mg/kg LD50 dermal Rabbit 2620 mg/kg

Questions And Answer(Q&A)

To a flask equipped with a Dean-Stark trap, condenser, and mechanical stirrer is added 116 gm (1.0 mole) of maleic acid and 120 ml of tetrachloroethane. The contents are heated, the water (18 ml, 1.0 mole) distilled off as the azeotrope, and the residue distilled under reduced pressure to afford 87.7 gm (89.5%) of the anhydride, b.p. 82-84°C (15 mm), m.p. 53°C. The residue remaining in the flask consists of about 10 gm of fumaric acid, m.p. 287°C.
Fumaric and maleic acids both give maleic anhydride on heating. Fumaric acid must first be heated to a higher temperature to effect its conversion to maleic acid prior to its dehydration.
Preparation of Maleic Anhydride

Raw materials And Preparation Products

Hazard Information

General Description
Colorless crystalline needles, flakes, pellets, rods, briquettes, lumps or a fused mass. Melts at 113°F. Shipped both as a solid and in the molten state. Vapors, fumes and dusts strong irritate the eyes, skin and mucous membranes. Flash point 218°F. Autoignition temperature 890°F. Used to make paints and plastics and other chemicals.
Reactivity Profile
MALEIC ANHYDRIDE(108-31-6) react vigorously on contact with oxidizing materials. Reacts exothermically with water or steam. Undergoes violent exothermic decomposition reactions, producing carbon dioxide, in the presence of strong bases (sodium hydroxide, potassium hydroxide, calcium hydroxide), alkali metals (lithium, sodium, potassium), aliphatic amines (dimethylamine, trimethylamine), aromatic amines (pyridine, quinoline) at temperatures above 150° C [Vogler, C. A. et al., J. Chem. Eng. Data, 1963, 8, p. 620]. A 0.1% solution of pyridine (or other tertiary amine) in MALEIC ANHYDRIDE(108-31-6) at 185°C gives an exothermic decomposition with rapid evolution of gas [Chem Eng. News 42(8); 41 1964]. MALEIC ANHYDRIDE(108-31-6) is known as an excellent dienophile in the Diels-Alder reaction to produce phthalate ester derivatives. These reactions can be extremely violent, as in the case of 1-methylsilacyclopentadiene [J. Organomet., Chem., 1979, 179, c19]. MALEIC ANHYDRIDE(108-31-6) undergoes a potentially explosive exothermic Diels-Alder reaction with 1-methylsilacyclopenta-2,4-diene at 150C [Barton, T. J., J. Organomet. Chem., 1979, 179, C19], and is considered an excellent dieneophile for Diels-alder reactions [Felthouse, Timothy R. et al. "MALEIC ANHYDRIDE(108-31-6), Maleic Acid, and Fumaric Acid." Kirk-Othmer Encyclopedia of Chemical Technology. John Wiley & Sons, Inc. 2005].
Air & Water Reactions
Soluble in water. Reacts slowly with water to form maleic acid and heat.
Irritant to tissue. Dermal and respiratory sensitization. Questionable carcinogen.
Health Hazard
Inhalation causes coughing, sneezing, throat irritation. Skin contact causes irritation and redness. Vapors cause severe eye irritation; photophobia and double vision may occur.
Potential Exposure
Maleic anhydride is used in unsaturated polyester resins; Agricultural chemical, and lubricating additives; in the manufacture of unsaturated polyester resins; in the manufacture of fumaric acid; in alkyd resin manufacture; in the manufacture of pesticides e.g., malathion, maleic hydrazide, and captan).
First aid
If this chemical gets into the eyes, remove any contact lenses at once and irrigate immediately for at least15 minutes, occasionally lifting upper and lower lids. Seek medical attention immediately. If this chemical contacts the skin, remove contaminated clothing and wash immediately with soap and water. Seek medical attention immediately. If this chemical has been inhaled, remove from exposure, begin rescue breathing (using universal precautions, including resuscitation mask) if breathing has stopped and CPR if heart action has stopped. Transfer promptly to a medical facility. When this chemical has been swallowed, get medical attention. If victim is conscious, administer water or milk. Do not induce vomiting. The symptoms of asthma may be delayed for several hours and are aggravated by physical effort. Rest and medical observation are highly recommended. Medical observation is recommended for 24 to 48 hours after breathing overexposure, as pulmonary edema may be delayed. As first aid for pulmonary edema, a doctor or authorized paramedic may consider administering a drug or other inhalation therapy
Fire Hazard
Behavior in Fire: When heated above 300°F in the presence of various materials may generate heat and carbon dioxide. Will explode if confined.
UN2215 Maleic anhydride, Hazard class: 8; Labels: 8-Corrosive material.
Reacts slowly with water (hydrolyzes) to form maleic acid, a medium-strong acid. Dust may form explosive mixture with air. Reacts with strong oxidizers, oil, water, alkali metals; strong acids; strong bases. Violent reaction with alkali metals and amines above 66C. Dangerous reaction with oxidizers, amines, alkali metals, and hydroxides. Compounds of the carboxyl group react with all bases, both inorganic and organic (i.e., amines) releasing substantial heat, water and a salt that may be harmful. Incompatible with arsenic compounds (releases hydrogen cyanide gas), diazo compounds, dithiocarbamates, isocyanates, mercaptans, nitrides, and sulfides (releasing heat, toxic, and possibly flammable gases), thiosulfates and dithionites (releasing hydrogen sulfate and oxides of sulfur)
Maleic Anhydride (MAN) is an organic compound with the chemical formula C4H203. It is the acid anhydride of maleic acid and in its pure state it is a colourless or white solid with an acrid odour. Maleic anhydride is truly a remarkable molecule in that it possesses two types of chemical functionality making it uniquely useful in chemical synthesis and applications.
Maleic Anhydride
Maleic Anhydride is a multifunctional chemical intermediate with applications in several fields of chemical industry. Its major end use is as feedstock in the production of unsaturated polyester resins (UPR).
These resins are used both in glass-reinforced and in unreinforced applications. The UPR end uses includes a wide range of applications in construction, marine and automobile industries.
In addition, Maleic Anhydride can also be used as raw material in the production of 1,4-butanediol (BDO), gamma- butyrolactone and tetrahydrofuran (THF). It is important to highlight that BDO is one of the world's fastest growing chemicals in the last years.
Chemical Properties
Maleic anhydride is colorless needles, white lumps, or pellets. Irritating, choking odor.
Waste Disposal
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. Controlled incineration: care must be taken that complete oxidation to nontoxic products occurs.
Physical properties
White, hydroscopic crystals (usually shipped as briquettes). Odor threshold concentration is 0.32 ppm (quoted, Amoore and Hautala, 1983).
In Diels-Alder syntheses (as a dienophile), manufacture of alkyd-type of resins, dye intermediates, pharmaceuticals, agricultural chemicals (maleic hydrazide, malathion), in copolymerization reactions.
In the manufacture of polyester resins, fumaric acid, agricultural pesticides, and alkyl resins
Maleic Anhydride is heterocyclic compound used in the manufacture of unsaturated polyester resins. Maleic Anhydride has a wide range of other applications; it is used in synthetic tensides, insecticides, herbicides and fungicides.
Production Methods
Maleic anhydride was traditionally manufactured by the oxidation of benzene or other aromatic compounds. As of 2006, only a few smaller plants continue to use benzene; due to rising benzene prices, most maleic anhydride plants now use n-butane as a feedstock.
In both cases, benzene and butane are fed into a stream of hot air, and the mixture is passed through a catalyst bed at high temperature. The ratio of air to hydrocarbon is controlled to prevent the mixture from catching on fire. Vanadium pentoxide and molybdenum trioxide are the catalysts used for the benzene route, whereas vanadium and phosphorus oxides are used for the butane route.
2 CH3CH2CH2CH3 + 7 O2 → 2 C2H2(CO)2O + 8 H2O.
ChEBI: A cyclic dicarboxylic anhydride that is the cyclic anhydride of maleic acid.
maleic anhydride: A colourlesssolid, C4H2O3, m.p. 53°C, the anhydrideof cis-butenedioic acid (maleicacid). It is a cyclic compound with aring containing four carbon atomsand one oxygen atom, made by thecatalytic oxidation of benzene or itsderivatives at high temperatures. It isused mainly in the manufacture ofalkyd and polyester resins andcopolymers.
The chemistry of maleic anhydride is very rich, reflecting its ready availability and bifunctional reactivity. It hydrolyzes, producing maleic acid, cis-HOOC–CH=CH–COOH. With alcohols, the halfester is generated, e.g., cis-HOOC–CH=CH–COOCH3.
Maleic anhydride is a potent dienophile in Diels-Alder reactions. It is also a ligand for low-valent metal complexes, examples being Pt(PPh3)2(MA) and Fe(CO)4(MA).
Maleic anhydride dimerizes in a photochemical reaction to form cyclo butane tetra carboxylic dianhydride (CBTA). This compound is used in the production of polyimides and as an alignment film for liquid crystal displays.
Synthesis Reference(s)
The Journal of Organic Chemistry, 60, p. 6676, 1995 DOI: 10.1021/jo00126a013
Environmental Fate
Chemical/Physical. Reacts with water forming maleic acid (Bunton et al., 1963). Anticipated products from the reaction of maleic anhydride with ozone or OH radicals in the atmosphere are carbon monoxide, carbon dioxide, aldehydes, and esters (Cupitt, 1980).
Solubility in organics
(wt % at 25 °C):
Acetone (227), benzene (50), carbon tetrachloride (0.60), chloroform (52.5), ethyl acetate (112), ligroin (0.25), toluene (23.4), o-xylene (19.4) (Windholz et al., 1983). Soluble in alcohol and 1,4- dioxane (Hawley, 1981).
Purification Methods
Crystallise it from *benzene, CHCl3, CH2Cl2 or CCl4. Sublime it under reduced pressure. [Skell et al. J Am Chem Soc 108 6300 1986, Beilstein 17 III/IV 5897, 17/11 V 55.]
Toxicity evaluation
Maleic anhydride was described as having anticarcinogenic properties, and some of the maleic copolymers can have biologic activity by themselves, especially antitumor activity. Information related to this compound is contradictory. Chromosomal aberrations in cultured hamster cells but no mutagenicity in in vitro tests in bacteria have been reported. No effects on cholinesterase activity have been described after exposure to maleic anhydride.

Material Safety Data Sheet(MSDS)

Spectrum Detail

Well-known Reagent Company Product Information