Substance profile
2-Butyne-1,4-diol
2-Butyne-1,4-diol is plates from benzene and ethyl acetate.
01 · Identification
What 2-Butyne-1,4-diol is
2-Butyne-1,4-diol is plates from benzene and ethyl acetate. Its molecular formula is C4H6O2 and its molecular weight is 86.09 g/mol. It boils at 238 °C, melts at 50 °C, is soluble in water.
Under the GHS it carries the signal word Danger. It is classed as reactive agents - 1st degree.
Other names for 2-Butyne-1,4-diol
- but-2-yne-1,4-diol
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 |
|---|---|
| H331 | Toxic if inhaled. |
| H301 | Toxic if swallowed. |
| H312 | Harmful in contact with skin. |
| 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>. |
| H314 | Causes severe skin burns and eye damage. |
| H317 | May cause an allergic skin reaction. |
Precautionary statements: P260, P261, P270, P271, P272, P280, P301, P302, P304, P310, P312, P313, P314, P330, P331, P333, P352
03 · Physical and chemical properties
2-Butyne-1,4-diol 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 | 238 °C (460.4 °F) | HSDB | |
| 237.78 °C (460 °F) | at 760 mmHg | CAMEO | |
| 238 °C (460.4 °F) | at 760 mmHg | DOE PAC | |
| Melting point | 50 °C (122 °F) | HSDB | |
| 58 °C (136.4 °F) | ICSC | ||
| Density | 1.1 g/cm³ | ICSC | |
| 1.115 g/cm³ | at 20 °C | HSDB | |
| 1.07 g/cm³ | at 20 °C | CAMEO | |
| Solubility | Insoluble in benzene; slightly soluble in ethyl ether, choroform; very soluble in ethanol, acetone, methanol | HSDB | |
| Soluble in aqueous acids. | HSDB | ||
| In water, 3.74X10+6 mg/L at 25 °C | at 25 °C | HSDB | |
| Vapor pressure | 0.0015 mmHg | at 20 °C | ICSC |
| 0.000556 mmHg | at 25 °C | HSDB | |
| 0.000556 mmHg | Haz-Map | ||
| Flash point | 128.33 °C (263 °F) | HSDB | |
| 152 °C (305.6 °F) | ICSC | ||
| Autoignition temperature | 335 °C (635 °F) | ICSC | |
| Lower explosive limit (LEL) | Explosive reaction with traces of alkalies, alkali earth hydroxides, halide salts, strong acids, mercury salts plus strong acids. | HSDB | |
| Vapor density | 3 (air = 1) | ICSC |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
04 · Handling and storage
Storing and handling 2-Butyne-1,4-diol
Storage conditions
The storage temperature should be kept below 40 °C and storage times longer than a few months should be avoided because the butynediol flakes tend to set up.
Source: Hazardous Substances Data Bank (HSDB)
Incompatible materials
The pure diol may be distilled unchanged, but traces of alkali or alkaline earth hydroxides or halides may cause explosive decomposition during distillation. In presence of strong acids, mercury salts may cause violent decomposition of the diol.
Source: Hazardous Substances Data Bank (HSDB)
Reactivity
Pure 1,4-BUTYNEDIOL is non-explosive. Small amounts of certain impurities-alkali hydroxides, alkaline earth hydroxides, halides-may cause explosive decomposition upon distillation. Butynediol should not be treated with basic catalysts in the absence of a solvent at room temperature, and its stability is less with elevated temperatures. In strong acids, contamination with mercury salts can also result in violent decomposition. [NFPA 491M 1991].
Source: CAMEO Chemicals
Planning storage for a mix of chemicals? Check 2-Butyne-1,4-diol in the storage compatibility matrix →