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

Chloroprene

Chloroprene is a colorless liquid with a pungent, ether-like odor.

CAS 126-99-8 Danger

01 · Identification

What Chloroprene is

Chloroprene is a colorless liquid with a pungent, ether-like odor. It boils at 59.4 °C, melts at -130 °C, is soluble in water.

Under the GHS it carries the signal word Danger. It is classed as hazardous Air Pollutants (HAPs).

CAS number126-99-8
EC number204-818-0
Index number602-036-00-8
Chemical class Hazardous Air Pollutants (HAPs)

Other names for Chloroprene

  • chloroprene (stabilised)
  • 2-chlorobuta-1,3-diene (stabilised)

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 wordDanger
Hazard statements assigned to Chloroprene
CodeHazard statement
H225 Highly flammable liquid and vapour.
H350 May cause cancer <state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard>.
H332 Harmful if inhaled.
H302 Harmful if swallowed.
H335 May cause respiratory irritation.
H373 May cause damage to organs <or state all organs affected, if known> through prolonged or repeated exposure <state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard>.
H315 Causes skin irritation.
H319 Causes serious eye irritation.

Precautionary statements: P201, P210, P233, P241, P242, P260, P264, P270, P271, P280, P301, P302, P304, P305, P308, P312, P313, P314, P330, P332, P337, P338, P352, P403

03 · Physical and chemical properties

Chloroprene 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 59.4 °C (138.9 °F) HSDB
59.44 °C (139 °F) NIOSH
59.39 °C (138.9 °F) at 760 mmHg CAMEO
Melting point -130 °C (-202 °F) HSDB
-102.78 °C (-153 °F) NIOSH
Density 0.96 g/cm³ NIOSH
0.956 g/cm³ at 20 °C HSDB
0.9583 g/cm³ at 20 °C CAMEO
Solubility Miscible in ethyl ether, acetone, and benzene; slightly soluble in water. HSDB
Soluble in alcohol, diethyl ether HSDB
Slight NIOSH
Vapor pressure 188 mmHg NIOSH
174.014 mmHg at 20 °C ICSC
215 mmHg at 25 °C HSDB
Flash point -20 °C (-4 °F) OPEN CUP HSDB
-20 °C (-4 °F) NIOSH
Autoignition temperature 440 °C (824 °F) ICSC
Lower explosive limit (LEL) 4 % by volume HSDB
1.9 % by volume NIOSH
Upper explosive limit (UEL) 20 % by volume HSDB
11.3 % by volume NIOSH
Vapor density 3 (air = 1) HSDB
3.1 (air = 1) ICSC
Odor threshold Odor Threshold Low: 0.11 [ppm] Haz-Map
Odor Threshold High: 138.0 [ppm] Haz-Map
Odor threshold from AIHA Haz-Map

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

04 · Handling and storage

Storing and handling Chloroprene

Storage conditions

/OXIDATION/...INHIBITED BY STORAGE AT LESS THAN -15 °C AND/OR BY THE ADDN OF ANTIOXIDANTS TO THE FRESH DISTILLATE.

Source: Hazardous Substances Data Bank (HSDB)

Incompatible materials

Peroxides & other oxidizers [Note: Polymerizes at room temperature unless inhibited with antioxidants].

Source: Hazardous Substances Data Bank (HSDB)

Reactivity

CHLOROPRENE emits highly toxic fumes of chlorine gas when heated to decomposition. Autooxidizes very rapidly with air and, even at 0 °C, produces unstable peroxides that catalyze exothermic polymerization [Bretherick, 5th ed., 1995, p. 507]. This reactivity is greatly slowed by presence of an inhibitor.

Source: CAMEO Chemicals

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

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