Substance profile
Maleic Anhydride
Maleic Anhydride is orthorhombic needles from chloroform; commercial grades furnished in fused form with a pungent odor.
01 · Identification
What Maleic Anhydride is
Maleic Anhydride is orthorhombic needles from chloroform; commercial grades furnished in fused form with a pungent odor. Its molecular formula is C4H2O3 and its molecular weight is 98.06 g/mol. It boils at 202 °C, melts at 52.6 °C, is soluble in water.
Under the GHS it carries the signal word Danger. It is classed as hazardous Air Pollutants (HAPs).
02 · GHS classification
Hazards and label elements
Harmonised classification under CLP Annex VI. This is the legally binding classification in the EU; other jurisdictions may differ.
| Code | Hazard statement |
|---|---|
| H302 | Harmful if swallowed. |
| H372 | Causes damage to organs <or state all organs affected, if known> through prolonged or repeated exposure <state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard>. |
| H314 | Causes severe skin burns and eye damage. |
| H318 | Causes serious eye damage. |
| H334 | May cause allergy or asthma symptoms or breathing difficulties if inhaled. |
| H317 | May cause an allergic skin reaction. |
Supplemental EU statements: EUH071
Precautionary statements: P260, P261, P270, P272, P280, P301, P305, P310, P312, P313, P314, P330, P331, P333, P338
03 · Physical and chemical properties
Maleic Anhydride properties
Every value is shown with the conditions it was measured under and the source it came from. Where sources disagree, all values are listed rather than one being picked — the difference is usually a different form of the substance, not an error.
| Property | Value | Conditions | Source |
|---|---|---|---|
| Boiling point | 202 °C (395.6 °F) | at 760 mmHg | HSDB |
| 202.22 °C (396 °F) | NIOSH | ||
| 202 °C (395.6 °F) | ICSC | ||
| Melting point | 52.56 °C (126.6 °F) | HSDB | |
| 52.78 °C (127 °F) | NIOSH | ||
| Density | 1.48 g/cm³ | NIOSH | |
| 1.5 g/cm³ | ICSC | ||
| 0.934 g/cm³ | at 20 °C | HSDB | |
| Solubility | In water: reaction with water | HSDB | |
| Soluble in water, forming maleic acids | HSDB | ||
| Soluble; decomposes in hot solvent (NTP, 1992) | decomposes | CAMEO | |
| Vapor pressure | 0.2 mmHg | NIOSH | |
| 0.25 mmHg | at 25 °C | HSDB | |
| Flash point | 102 °C (215.6 °F) | closed cup | HSDB |
| 110 °C (230 °F) | open cup | HSDB | |
| 103.33 °C (218 °F) | NIOSH | ||
| Autoignition temperature | 477 °C (890.6 °F) | HSDB | |
| 470 °C (878 °F) | CAMEO | ||
| Lower explosive limit (LEL) | 7.1 % by volume | Upper | HSDB |
| 1.4 % by volume | HSDB | ||
| Upper explosive limit (UEL) | 7.1 % by volume | HSDB | |
| Vapor density | 3.38 (air = 1) | HSDB | |
| 3.4 (air = 1) | ICSC | ||
| Odor threshold | Odor low: 1.84 mg/mL; Odor high: 1.96 mg/mL | HSDB | |
| Odor threshold 0.3 ppm (0.001223 mg/L)... reported for off-gases in manufacture. | HSDB | ||
| Odor Threshold Low: 0.25 [mg/m3] | Haz-Map | ||
| Corrosivity | Corrosive material. | HSDB |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
04 · Handling and storage
Storing and handling Maleic Anhydride
Storage conditions
Keep container tightly closed in a dry and well-ventilated place. Moisture sensitive. Storage class (TRGS 510): Non-combustible, corrosive hazardous materials
Source: Hazardous Substances Data Bank (HSDB)
Incompatible materials
Incompatible with alkali metals, caustics, and amines at greater than 150 °F.
Source: Hazardous Substances Data Bank (HSDB)
Planning storage for a mix of chemicals? Check Maleic Anhydride in the storage compatibility matrix →