Substance profile
Acetonitrile
Acetonitrile is colorless, limpid liquid with an aromatic odor.
01 · Identification
What Acetonitrile is
Acetonitrile is colorless, limpid liquid with an aromatic odor. Its molecular formula is C2H3N and its molecular weight is 41.05 g/mol. It boils at 81.6 °C, melts at -44 °C.
Under the GHS it carries the signal word Danger. It is classed as hazardous Air Pollutants (HAPs).
Other names for Acetonitrile
- ACN
- methyl cyanide
- CH3CN
- Acetonitrile Cluster
- Cyanomethane
- Ethanenitrile
- Ethyl Nitrile
- Methane, Cyano-
- Methanecarbonitrile
- Methyl Cyanide (Mecn)
- Usaf Ek-488
- cyanomethane
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. |
| H332 | Harmful if inhaled. |
| H312 | Harmful in contact with skin. |
| H302 | Harmful if swallowed. |
| H319 | Causes serious eye irritation. |
Precautionary statements: P210, P233, P241, P242, P260, P264, P270, P271, P280, P301, P302, P304, P305, P312, P313, P330, P337, P338, P352, P403
03 · Physical and chemical properties
Acetonitrile 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 | 81.6 °C (178.9 °F) | at 760 mmHg | HSDB |
| 20 °C (68 °F) | HSDB | ||
| 81.67 °C (179 °F) | NIOSH | ||
| Melting point | -44 °C (-47.2 °F) | HSDB | |
| -45 °C (-49 °F) | NIOSH | ||
| Density | 0.78 g/cm³ | NIOSH | |
| 0.8 g/cm³ | ICSC | ||
| 0.787 g/cm³ | at 20 °C | CAMEO | |
| Solubility | In water, >800 g/L at 25 °C | at 25 °C | HSDB |
| In water, infinite solubility at 25 °C | at 25 °C | HSDB | |
| Vapor pressure | 73 mmHg | NIOSH | |
| 73 mmHg | at 20 °C | CAMEO | |
| 88.8 mmHg | at 25 °C | HSDB | |
| Flash point | 5.56 °C (42 °F) | HSDB | |
| Autoignition temperature | 523.89 °C (975 °F) | HSDB | |
| 524 °C (975.2 °F) | ICSC | ||
| Lower explosive limit (LEL) | 3 % by volume | HSDB | |
| Upper explosive limit (UEL) | 16 % by volume | HSDB | |
| Vapor density | 1.42 (air = 1) | HSDB | |
| 1.4 (air = 1) | ICSC | ||
| Odor threshold | Low: 70.0 mg/cu m; High: 70.0 mg/cu m; Irritating: 875 mg/cu m | HSDB | |
| Odor Threshold Low: 40.0 [ppm] | Haz-Map | ||
| Odor Threshold High: 1161.0 [ppm] | Haz-Map | ||
| Critical temperature and pressure | 272.3 °C (522.1 °F) | HSDB | |
| Corrosivity | Liquid acetonitrile will attack some forms of plastics, rubber, and coatings. | HSDB |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
04 · Source notes
Further notes on Acetonitrile
These are descriptions rather than measured values, so they are kept out of the table above and quoted here with the source that reported them.
Solubility
Miscible with methanol, methyl acetate, ethyl acetate, ether, acetamide solutions, chloroform, carbon tetrachloride, ethylene chloride, and with many unsaturated hydrocarbons; immiscible with many saturated hydrocarbons (petroleum fractions).
Source: HSDB
05 · Handling and storage
Storing and handling Acetonitrile
Storage conditions
Protect containers against physical damage. Outdoor or detached storage is preferable. Separate from any sources of ignition and combustible materials. Storage room should be well-ventilated.
Source: Hazardous Substances Data Bank (HSDB)
Incompatible materials
Strong oxidizers such as chlorine, bromine, and fluorine; chlorosulfonic acid; oleum or sulfuric acid. May accumulate static electricial charges, and may cause ignition of its vapors.
Source: Hazardous Substances Data Bank (HSDB)
Reactivity
ACETONITRILE decomposes when heated to produce deadly toxic hydrogen cyanide gas and oxides of nitrogen. Strongly reactive [Hawley]. May react vigorously with strong oxidizing reagents, sulfuric acid, chlorosulfonic acid, sulfur trioxide, perchlorates, nitrating reagents, and nitric acid. [Sax, 9th ed., 1996, p. 20]. Potentially explosive in contact with nitrogen-fluorine compounds (e.g., tetrafluorourea) [Fraser, G. W. et al., Chem. Comm., 1966, p. 532].
Source: CAMEO Chemicals
Planning storage for a mix of chemicals? Check Acetonitrile in the storage compatibility matrix →
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