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

Cyclopentanone

Cyclopentanone is a water-white, mobile liquid with a distinctive ethereal odor, somewhat like peppermint.

CAS 120-92-3 C5H8O 84.12 g/mol Warning

01 · Identification

What Cyclopentanone is

Cyclopentanone is a water-white, mobile liquid with a distinctive ethereal odor, somewhat like peppermint. Its molecular formula is C5H8O and its molecular weight is 84.12 g/mol. It boils at 131 °C, melts at -51.3 °C.

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

CAS number120-92-3
EC number204-435-9
Index number606-025-00-9
Molecular formulaC5H8O
Molecular weight84.12 g/mol
Chemical class Flammable agents - 3rd degree

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 Cyclopentanone
CodeHazard statement
H226 Flammable liquid and vapour.
H315 Causes skin irritation.
H319 Causes serious eye irritation.

Precautionary statements: P210, P233, P241, P242, P264, P280, P302, P305, P313, P332, P337, P338, P352, P403

03 · Physical and chemical properties

Cyclopentanone 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 130.6 °C (267.1 °F) at 760 mmHg HSDB
130.65 °C (267.2 °F) at 760 mmHg CAMEO
131 °C (267.8 °F) ICSC
Melting point -51.3 °C (-60.3 °F) HSDB
-51.28 °C (-60.3 °F) CAMEO
-51 °C (-59.8 °F) ICSC
Density 0.95 g/cm³ ICSC
0.9487 g/cm³ at 20 °C HSDB
Solubility Sol in alcohol, acetone, ether HSDB
Estimated water solubility of 9175 mg/l HSDB
Solubility in water: poor ICSC
Vapor pressure 11.4 mmHg at 25 °C HSDB
11.4 mmHg Haz-Map
Flash point 30.56 °C (87 °F) HSDB
30 °C (86 °F) CAMEO
26 °C (78.8 °F) ICSC
Vapor density 2.3 (air = 1) HSDB

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

04 · Handling and storage

Storing and handling Cyclopentanone

Reactivity

CYCLOPENTANONE polymerizes easily, especially in the presence of acids. Can react with oxidizing materials, i.e. hydrogen peroxide. (NTP, 1992)

Source: CAMEO Chemicals

Planning storage for a mix of chemicals? Check Cyclopentanone in the storage compatibility matrix →

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