Provenance

Reference data from EU CLP Annex VI and published regulations — verify against your supplier's SDS before use.

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Substance profile

4-methylpent-3-en-2-one

4-methylpent-3-en-2-one is an oily, colorless to light-yellow liquid with a spearmint odor.

CAS 141-79-7 C6H10O 98.14 g/mol Warning

01 · Identification

What 4-methylpent-3-en-2-one is

4-methylpent-3-en-2-one is an oily, colorless to light-yellow liquid with a spearmint odor. Its molecular formula is C6H10O and its molecular weight is 98.14 g/mol. It boils at 130 °C, melts at -59 °C.

Under the GHS it carries the signal word Warning. It is classed as flammable agents - 3rd degree.

CAS number141-79-7
EC number205-502-5
Index number606-009-00-1
Molecular formulaC6H10O
Molecular weight98.14 g/mol
Chemical class Flammable agents - 3rd degree

Other names for 4-methylpent-3-en-2-one

  • mesityl oxide

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.

Signal wordWarning
Hazard statements assigned to 4-methylpent-3-en-2-one
CodeHazard statement
H226 Flammable liquid and vapour.
H332 Harmful if inhaled.
H312 Harmful in contact with skin.
H302 Harmful if swallowed.

Precautionary statements: P210, P233, P241, P242, P260, P270, P271, P280, P301, P302, P304, P312, P330, P352, P403

03 · Physical and chemical properties

4-methylpent-3-en-2-one 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 130 °C (266 °F) at 760 mmHg HSDB
130 °C (266 °F) NIOSH
Melting point -59 °C (-74.2 °F) HSDB
-41.5 °C (-42.7 °F) HSDB
-46.67 °C (-52 °F) NIOSH
Density 0.87 g/cm³ ICSC
0.8508 g/cm³ at 20 °C HSDB
0.853 g/cm³ at 20 °C CAMEO
Solubility Sol in about 30 parts water; miscible with most org liq HSDB
Miscible in ethanol, ethyl ether HSDB
SLIGHTLY SOL IN PROPYLENE GLYCOL HSDB
Vapor pressure 9 mmHg NIOSH
8.21 mmHg at 25 °C HSDB
Flash point 30.56 °C (87 °F) HSDB
22.78 °C (73 °F) CAMEO
Autoignition temperature 344.44 °C (652 °F) HSDB
340 °C (644 °F) ICSC
Lower explosive limit (LEL) 1.4 % by volume HSDB
Upper explosive limit (UEL) 7.2 % by volume HSDB
Vapor density 3.4 (air = 1) HSDB
Odor threshold Odor low: 0.068 mg/cu m; Odor high: 100 mg/cu m. HSDB
Odor threshold values: 50% detection: 12 ppm; 100% detection: 25 ppm. HSDB
The absolute perception limit has been reported to be 0.017 ppm. HSDB

Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.

04 · Handling and storage

Storing and handling 4-methylpent-3-en-2-one

Storage conditions

Fireproof. Separated from strong oxidants. Cool. Keep in the dark.

Source: Hazardous Substances Data Bank (HSDB)

Incompatible materials

Mixing mesityl oxide and 2-aminoethanol /or chlorosulfonic acid or ethylene diamine or nitric acid or oleum or sulfuric acid/ in closed container caused temp and pressure to incr.

Source: Hazardous Substances Data Bank (HSDB)

Reactivity

Mixing MESITYL OXIDE in equal molar proportions with any of the following substances in a closed container caused the temperature and pressure to increase: 2-aminoethanol, chlorosulfonic acid, ethylene diamine, nitric acid, oleum, or sulfuric acid [NFPA 1991].

Source: CAMEO Chemicals

Planning storage for a mix of chemicals? Check 4-methylpent-3-en-2-one in the storage compatibility matrix →

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