Substance profile
Methyl ethyl ketone
Methyl ethyl ketone is a colorless liquid with an acetone-like odor.
01 · Identification
What Methyl ethyl ketone is
Methyl ethyl ketone is a colorless liquid with an acetone-like odor. Its molecular formula is C4H8O and its molecular weight is 72.11 g/mol. It boils at 79.6 °C, melts at -86.7 °C.
Under the GHS it carries the signal word Danger. It is classed as hazardous Air Pollutants (HAPs).
Other names for Methyl ethyl ketone
- MEK
- butanone
- 2-butanone
- 3-Butanone
- Ethyl Methyl Ketone
- Ketone, Ethyl Methyl
- Meetco
- Methyl Acetone
- Methyl Ethyl Ketone (Mek)
- ethyl methyl ketone
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. |
| H336 | May cause drowsiness or dizziness. |
| H319 | Causes serious eye irritation. |
Supplemental EU statements: EUH066
Precautionary statements: P210, P233, P241, P242, P264, P280, P305, P313, P337, P338, P403
03 · Physical and chemical properties
Methyl ethyl ketone 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 | 79.59 °C (175.3 °F) | HSDB | |
| 79.44 °C (175 °F) | NIOSH | ||
| 79.61 °C (175.3 °F) | at 760 mmHg | CAMEO | |
| Melting point | -86.67 °C (-124 °F) | HSDB | |
| -86.11 °C (-123 °F) | NIOSH | ||
| -86.28 °C (-123.3 °F) | CAMEO | ||
| Density | 0.81 g/cm³ | NIOSH | |
| 0.805 g/cm³ | at 20 °C | HSDB | |
| 0.804 g/cm³ | at 20 °C | HSDB | |
| Solubility | Soluble in benzene, alcohol, and ether; miscible with oils | HSDB | |
| Constant boiling mixture with water, BP 73.4 °C, contains 88.7% methyl ethyl ketone (MEK); Solubility of water in MEK is 12.5% at 25 °C | at 25 °C | HSDB | |
| In water, 2.23X10+5 mg/L at 25 °C | at 25 °C | HSDB | |
| Vapor pressure | 78 mmHg | NIOSH | |
| 77.5 mmHg | at 20 °C | CAMEO | |
| 90.6 mmHg | at 25 °C | HSDB | |
| Flash point | -8.89 °C (16 °F) | HSDB | |
| -9 °C (15.8 °F) | closed cup | HSDB | |
| Autoignition temperature | 505 °C (941 °F) | HSDB | |
| 516.11 °C (961 °F) | CAMEO | ||
| Lower explosive limit (LEL) | 1.8 % by volume | CAMEO | |
| Upper explosive limit (UEL) | 10 % by volume | CAMEO | |
| 11.5 % by volume | ICSC | ||
| 11.4 % by volume | at 93.33 °C | HSDB | |
| Vapor density | 2.41 (air = 1) | HSDB | |
| 2.42 (air = 1) | CAMEO | ||
| Odor threshold | Odor low= 0.7375 mg/cu m; Odor high= 147.5 mg/cu m. | HSDB | |
| Detection limit in water: 5.00x10+1 ppm (purity not specified) | HSDB | ||
| Recognition in air: 1.00x10+1 ppm (chemically pure) | HSDB | ||
| Critical temperature and pressure | 263.55 °C (506.4 °F) | HSDB |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
04 · Handling and storage
Storing and handling Methyl ethyl ketone
Storage conditions
Methyl ethyl ketone must be stored to avoid contact with strong oxidizers (such as chlorine, bromine, and fluorine) since violent reactions may occur. Store in tightly closed containers in a cool, well ventilated area away from sources of heat, sparks, or flame. Sources of ignition such as smoking and open flames are prohibited where methyl ethyl ketone is handled, used or stored in a manner that could create a potential fire or explosion hazard. Metal containers involving the transfer of 5 gallons or more of diethyl ketone should be grounded and bonded. Drums must be equipped with self-closing valves, pressure vacuum bungs, and flame arresters. Use only non-sparking tools and equipment, especially when opening and closing containers of methyl ethyl ketone.
Source: Hazardous Substances Data Bank (HSDB)
Incompatible materials
Reacts violently with strong oxidants and inorganic acids causing fire and explosion hazard. Attacks some plastic.
Source: Hazardous Substances Data Bank (HSDB)
Reactivity
METHYL ETHYL KETONE is explosive in the form of vapor when exposed to heat, flame or sparks. Ignition on contact with potassium tert-butoxide. Reactive with strong oxidizing materials, and will dissolve or soften some plastics. Mixture with 2-propanol will form explosive peroxides during storage. Vigorous reaction with chloroform in the presence of alkali (sodium hydroxide, potassium hydroxide), chlorosulfonic acid, fuming sulfuric acid (oleum) [Lewis, 3rd ed., 1993, p. 855]. Reaction with hydrogen peroxide in the presence of nitric acid forms heat- and shock-sensitive explosive acetone peroxides. [Bjorklund, G. H. et al., Trans. R. Soc. Can, 1950, 44, p. 25].
Source: CAMEO Chemicals
Planning storage for a mix of chemicals? Check Methyl ethyl ketone in the storage compatibility matrix →
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