Substance profile
Acetyl chloride
Acetyl chloride is a liquid with a pungent odor.
01 · Identification
What Acetyl chloride is
Acetyl chloride is a liquid with a pungent odor. Its molecular formula is C2H3ClO and its molecular weight is 78.5 g/mol. It boils at 51 °C, melts at -113 °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 |
|---|---|
| H225 | Highly flammable liquid and vapour. |
| H314 | Causes severe skin burns and eye damage. |
Supplemental EU statements: EUH014
Precautionary statements: P210, P233, P241, P242, P260, P280, P301, P310, P331, P403
03 · Physical and chemical properties
Acetyl chloride 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 | 51 °C (123.8 °F) | HSDB | |
| 50.89 °C (123.6 °F) | at 760 mmHg | CAMEO | |
| Melting point | -112.7 °C (-170.9 °F) | HSDB | |
| -112.22 °C (-170 °F) | CAMEO | ||
| -112 °C (-169.6 °F) | ICSC | ||
| Density | 1.1029 g/cm³ | at 21.11 °C | HSDB |
| 1.1039 g/cm³ | at 21 °C | CAMEO | |
| 1.1051 g/cm³ | at 20 °C | HSDB | |
| Solubility | Miscible with benzene, chloroform, ether, glacial acetic acid, petroleum ether | HSDB | |
| Miscible with ether, acetone, benzene, chloroform; soluble in carbon tetrachloride | HSDB | ||
| Decomposed violently by water or alcohol | decomposes | HSDB | |
| Vapor pressure | 240.02 mmHg | at 20 °C | ICSC |
| 287 mmHg | at 25 °C | HSDB | |
| Flash point | 5 °C (41 °F) | HSDB | |
| 4 °C (39.2 °F) | HSDB | ||
| 4.44 °C (40 °F) | CAMEO | ||
| Autoignition temperature | 390 °C (734 °F) | HSDB | |
| Lower explosive limit (LEL) | 5 % by volume | HSDB | |
| 7.3 % by volume | ICSC | ||
| Upper explosive limit (UEL) | 19 % by volume | ICSC | |
| Vapor density | 2.7 (air = 1) | HSDB | |
| 2.7 (air = 1) | at 37.78 °C | CAMEO | |
| Critical temperature and pressure | 246.11 °C (475 °F) | HSDB | |
| Corrosivity | Corrosive | HSDB | |
| Corrosive to metals and tissue | HSDB |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
04 · Handling and storage
Storing and handling Acetyl chloride
Storage conditions
Keep container tightly closed in a dry and well-ventilated place. Containers which are opened must be carefully resealed and kept upright to prevent leakage. Keep away from water. Never allow product to get in contact with water during storage. Hydrolyzes readily. Handle and store under inert gas.
Source: Hazardous Substances Data Bank (HSDB)
Incompatible materials
Incompatible materials: Water, alcohols, oxidizing agents, strong bases.
Source: Hazardous Substances Data Bank (HSDB)
Reactivity
ACETYL CHLORIDE reacts violently with water, steam, methanol or ethanol to form hydrogen chloride and acetic acid. Reacts vigorously with bases, both organic and inorganic. Incompatible with oxidizing agents and alcohols. Produces highly toxic fumes of phosgene gas and chlorine when heated to decomposition [Sax, 9th ed., 1996, p. 35]. Reaction in a confined space with even a small amount of water may cause a violent eruption of gases [Bretherick, 5th ed., 1995, p. 281]. Vapor forms an explosive mixture with air [Kirk-Othmer, 3rd ed., Vol. 1, 1978, p. 162]. Polymerization reaction with dimethyl sulfoxide is particularly violent [Buckley, A., J. Chem. Ed., 1965, 42, p. 674]. May react vigorously or explosively if mixed with diisopropyl ether or other ethers in the presence of trace amounts of metal salts [J. Haz. Mat., 1981, 4, 291].
Source: CAMEO Chemicals
Planning storage for a mix of chemicals? Check Acetyl chloride in the storage compatibility matrix →