Substance profile
Acetic Anhydride
Acetic Anhydride is a colorless liquid with a strong acetic odor.
01 · Identification
What Acetic Anhydride is
Acetic Anhydride is a colorless liquid with a strong acetic odor. Its molecular formula is C4H6O3 and its molecular weight is 102.09 g/mol. It boils at 140 °C, melts at -73.4 °C.
Under the GHS it carries the signal word Danger. It is classed as corrosives.
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 |
|---|---|
| H226 | Flammable liquid and vapour. |
| H332 | Harmful if inhaled. |
| H302 | Harmful if swallowed. |
| H314 | Causes severe skin burns and eye damage. |
Precautionary statements: P210, P233, P241, P242, P260, P270, P271, P280, P301, P304, P310, P312, P330, P331, P403
03 · Physical and chemical properties
Acetic 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 | 139.5 °C (283.1 °F) | HSDB | |
| 138.89 °C (282 °F) | NIOSH | ||
| 139.55 °C (283.2 °F) | at 760 mmHg | CAMEO | |
| Melting point | -73.4 °C (-100.1 °F) | HSDB | |
| -72.78 °C (-99 °F) | NIOSH | ||
| -73.11 °C (-99.6 °F) | CAMEO | ||
| Density | 1.08 g/cm³ | NIOSH | |
| 1.082 g/cm³ | at 20 °C | HSDB | |
| Solubility | Slowly soluble in water, forming acetic acid | HSDB | |
| In water, 120 g/L at 20 °C | at 20 °C | HSDB | |
| Soluble in cold (greater than or equal to 10mg/ml); Decomposes in hot (NTP, 1992) | decomposes | CAMEO | |
| Vapor pressure | 4 mmHg | NIOSH | |
| 3.7503 mmHg | at 20 °C | ICSC | |
| 5.1004 mmHg | at 25 °C | HSDB | |
| Flash point | 48.89 °C (120 °F) | HSDB | |
| 49.44 °C (121 °F) | CAMEO | ||
| Autoignition temperature | 316 °C (600.8 °F) | HSDB | |
| 330 °C (626 °F) | CAMEO | ||
| Lower explosive limit (LEL) | 2.7 % by volume | HSDB | |
| 2.9 % by volume | HSDB | ||
| Upper explosive limit (UEL) | 10.3 % by volume | HSDB | |
| Vapor density | 3.5 (air = 1) | HSDB | |
| 3.52 (air = 1) | CAMEO | ||
| Odor threshold | 0.13 uL/L | HSDB | |
| Odor Low: 0.56 mg/cu m; Odor High: 1.44 mg/cu m; Sharp odor, sour acid | HSDB | ||
| Odor Threshold Low: 0.12 [ppm] | Haz-Map | ||
| Critical temperature and pressure | 332.85 °C (631.1 °F) | HSDB | |
| Corrosivity | Corrosive | HSDB |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
04 · Handling and storage
Storing and handling Acetic Anhydride
Storage conditions
Store in cool, dry, well-ventilated location. Outside or detached storage is preferred. Store away from heat, oxidizers, and sunlight. Exclude moisture from vapor space in storage tanks.
Source: Hazardous Substances Data Bank (HSDB)
Incompatible materials
A violent reaction /acetic anhydride and glycerol/ occurs between these reactants in the presence of phosphorus oxychloride as a catalyst.
Source: Hazardous Substances Data Bank (HSDB)
Reactivity
ACETIC ANHYDRIDE reacts violently on contact with water, steam, methanol, ethanol, glycerol and boric acid. Reaction with water is particularly dangerous in presence with mineral acids (e.g., nitric, perchloric, chromic, sulfuric acid) [Chem. Eng. News 25, 3458]. Potentially explosive reactions with oxidizing reagents such as barium peroxide, chromium trioxide, chromic acid, hypochlorous acid, nitric acid, perchloric acid, peroxyacetic acid, potassium permanganate, hydrogen peroxide. [Sax, 9th ed., 1996, p. 15]. Reacts violently with metal nitrates used as nitrating agents [Davey W. et al., Chem. & Ind., 1948, p. 814].
Source: CAMEO Chemicals
Planning storage for a mix of chemicals? Check Acetic Anhydride in the storage compatibility matrix →