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CAS Number: 503-17-3
Sum Formula: C4H6
Molar Mass: 54.1 g/mol
German Synonyms: Dimethylacetylen | Crotonylen | Butin-2 | Butin-(2) | 2-Butin
English Synonyms: 2-Butyne
EC Number: 207-962-2
Structural Formula 2-Butyne

Disclaimer: The CLP/GHS classification is not regularly updated in Chemsafe. For up-to-date information, please use the ECHA database. ( https://echa.europa.eu/en/information-on-chemicals )

GHS Hazard and Category:
  • Flam. Liq. 1: flammable liquids, category 1
GHS Pictogram:
pictogram flammable





GHS Signal Word: Danger
GHS Hazard Statement:
  • H224: Extremely flammable liquid and vapour.

Antoine parameters
1 1987 Stephenson, R.M.; Malanowski, S. 6.19828 kPa UTI: 137-647-5161/0-39
UTI: 137-647-5161/0-39;
Line no Upper temperature limit of Antoine equation Lower temperature limit of Antoine equation Antoine constant C Antoine constant B Antoine constant A
  • recommended value
  • saturated
  • property of pure substance
  • recommended value
  • saturated
  • property of pure substance
  • recommended value
  • by regression
  • saturated
  • property of pure substance
  • recommended value
  • by regression
  • saturated
  • property of pure substance
  • defined value
  • by regression
  • saturated
  • property of pure substance
1 < 308 K > 240 K -37.34 K 1101.71 K 6.19828 kPa
Bibliographic data
Author Stephenson, R.M.; Malanowski, S.
Year 1987
Title Handbook of The Thermodynamics of Organic Compounds
Publisher Elsevier; New York, Amsterdam, London
Language ENGL
Boiling point
1 1941 Berger, H. 1013.25 hPa 28 °C UTI: 15-647-5155/0-39
UTI: 15-647-5155/0-39;
Line no Boiling temperature Pressure
  • defined value
  • at atmospheric pressure
  • saturated
  • property of pure substance
  • saturated
1 28 °C 1013.25 hPa
Bibliographic data
Title Brennbare Gase, Flüssigkeiten und feste Stoffe
Author Berger, H.
Year 1941
Publisher Edmund Stein u. Co.
Publisher City Potsdam
Language GERM
2 1950 1013.25 hPa 28 °C UTI: 1-647-5153/0-39
UTI: 1-647-5153/0-39;
Line no Boiling temperature Pressure
  • defined value
  • at atmospheric pressure
  • saturated
  • property of pure substance
  • saturated
1 28 °C 1013.25 hPa
Bibliographic data
Title Loss Prevention Bulletin No. 36.10: Properties of Flammable Liquids, Gases and Solids
Year 1950
Journal Title The Factory Mutual Engineering Division;Boston, Ma
Publisher The Factory Mutual Engineering Division
Publisher City Boston
Language ENGL
3 1963 Nabert, K.; Schön, G. 1013.25 hPa 27 °C UTI: 1000-647-5179/0-39
UTI: 1000-647-5179/0-39;
Line no Boiling temperature Pressure
  • defined value
  • at atmospheric pressure
  • property of pure substance
1 27 °C 1013.25 hPa
Bibliographic data
Author Nabert, K.; Schön, G.
Year 1963
Title Sicherheitstechnische Kennzahlen brennbarer Gase und Dämpfe (mit 6. Nachtrag)
Publisher Deutscher Eichverlag
Publisher City Braunschweig
Abstract English Safety values of about 1000 flammable gases and vapors: Explosion limits, ignition temperatures, flash points, explosion pressures.
Language GERM
4 1994 1013.25 hPa 28 °C UTI: 16-647-5158/0-39
UTI: 16-647-5158/0-39;
Line no Boiling temperature Pressure
  • defined value
  • at atmospheric pressure
  • saturated
  • property of pure substance
  • saturated
1 28 °C 1013.25 hPa
Bibliographic data
Year 1994
Title Fire-hazard Properties of certain Flammable Liquids, Gases and Volatile Solids
Publisher National Fire Protection Association
Publisher City Boston
Language ENGL
Density
1 1963 Nabert, K.; Schön, G. 1013.25 hPa 20 °C 0.69 g/cm3 UTI: 1000-647-5180/0-39
UTI: 1000-647-5180/0-39;
Line no Density Temperature Pressure
  • defined value
  • at atmospheric pressure and room temperature
  • property of pure substance
  • recommended value
  • at atmospheric pressure and room temperature
  • property of pure substance
  • recommended value
  • at atmospheric pressure and room temperature
1 0.69 g/cm3 20 °C 1013.25 hPa
Bibliographic data
Author Nabert, K.; Schön, G.
Year 1963
Title Sicherheitstechnische Kennzahlen brennbarer Gase und Dämpfe (mit 6. Nachtrag)
Publisher Deutscher Eichverlag
Publisher City Braunschweig
Abstract English Safety values of about 1000 flammable gases and vapors: Explosion limits, ignition temperatures, flash points, explosion pressures.
Language GERM
Melting point
1 1963 Nabert, K.; Schön, G. 1013.25 hPa -32 °C UTI: 1000-647-5182/0-39
UTI: 1000-647-5182/0-39;
Line no Melting temperature Pressure
  • defined value
  • at atmospheric pressure
  • saturated
  • property of pure substance
  • recommended value
  • at atmospheric pressure
  • saturated
1 -32 °C 1013.25 hPa
Bibliographic data
Author Nabert, K.; Schön, G.
Year 1963
Title Sicherheitstechnische Kennzahlen brennbarer Gase und Dämpfe (mit 6. Nachtrag)
Publisher Deutscher Eichverlag
Publisher City Braunschweig
Abstract English Safety values of about 1000 flammable gases and vapors: Explosion limits, ignition temperatures, flash points, explosion pressures.
Language GERM
Relative gas density
1 1941 Berger, H. 1.86 UTI: 15-647-5156/0-39
UTI: 15-647-5156/0-39;
Line no Relative gas density
  • defined value
  • property of pure substance
1 1.86
Bibliographic data
Title Brennbare Gase, Flüssigkeiten und feste Stoffe
Author Berger, H.
Year 1941
Publisher Edmund Stein u. Co.
Publisher City Potsdam
Language GERM
2 1963 Nabert, K.; Schön, G. 1.86 UTI: 1000-647-5181/0-39
UTI: 1000-647-5181/0-39;
Line no Relative gas density
  • defined value
  • property of pure substance
1 1.86
Bibliographic data
Author Nabert, K.; Schön, G.
Year 1963
Title Sicherheitstechnische Kennzahlen brennbarer Gase und Dämpfe (mit 6. Nachtrag)
Publisher Deutscher Eichverlag
Publisher City Braunschweig
Abstract English Safety values of about 1000 flammable gases and vapors: Explosion limits, ignition temperatures, flash points, explosion pressures.
Language GERM
3 1994 1.91 UTI: 16-647-5159/0-39
UTI: 16-647-5159/0-39;
Line no Relative gas density
  • defined value
  • property of pure substance
1 1.91
Bibliographic data
Year 1994
Title Fire-hazard Properties of certain Flammable Liquids, Gases and Volatile Solids
Publisher National Fire Protection Association
Publisher City Boston
Language ENGL
Solubility in water
1 2009 Physikalisch-Technische Bundesanstalt (PTB) 25 °C 3.4 g/l UTI: 228-647-5175/0-39
UTI: 228-647-5175/0-39;
Line no Solubility in water Temperature
  • defined value
  • estimated
  • property of pure substance
  • property of pure substance
1 3.4 g/l 25 °C
Bibliographic data
Author Physikalisch-Technische Bundesanstalt (PTB)
Year 2009
Title Wasserlöslichkeit
Database PTB
Publisher Datenbank PTB-Lab. 3.43
Language GERM
  • The oxidizing agent is air with an oxygen content of 20.95 % by volume. In the data base it is usually not specified as mixture component. Exceptions are highlighted.
  • Pressure values are absolute, not gauge pressures.
  • Impurities can strongly influence characteristic safety data, particulary if the properties of the impurity considerably deviate from the respective properties of the pure substance.
  • Safety characteristics are only displayed if evaluated data are available.
  • Values can be cited by using the UTI number of the table (Uniform Table Identifier).
  • Color Codes:         recommended value             no recommendation               do not use value

Flash point
1 1963 Nabert, K.; Schön, G. < -20 °C UTI: 1000-647-5177/0-39
UTI: 1000-647-5177/0-39;
Line no Flash point
  • recommended value
  • experimental
  • closed cup
  • property of pure substance
1 < -20 °C
Bibliographic data
Author Nabert, K.; Schön, G.
Year 1963
Title Sicherheitstechnische Kennzahlen brennbarer Gase und Dämpfe (mit 6. Nachtrag)
Publisher Deutscher Eichverlag
Publisher City Braunschweig
Abstract English Safety values of about 1000 flammable gases and vapors: Explosion limits, ignition temperatures, flash points, explosion pressures.
Language GERM
Limiting value for flammability (Tci)
1 2008 Physikalisch-Technische Bundesanstalt (PTB) 2 Mol% UTI: 232-647-5176/0-39
UTI: 232-647-5176/0-39;
Line no Limiting value for flammability (Tci)
  • recommended value
  • property of pure substance
1 2 Mol%
Bibliographic data
Author Physikalisch-Technische Bundesanstalt (PTB)
Year 2008
Title Draft for the revision of ISO 10156 'Gas cylinders - Gas and gas mixture - Determination of fire potential and oxidizing ability'
Database PTB
Publisher Datenbank PTB-Lab. 3.43
Language ENGL
Lower explosion limit
1 1963 Nabert, K.; Schön, G. 1.4 Vol% ± 10 % UTI: 1000-647-5183/0-39
UTI: 1000-647-5183/0-39;
Line no Lower explosion limit
  • recommended value
  • property of pure substance
1 1.4 Vol% ± 10 %
2 30 g/m3 ± 10 % ⚠
⚠ The reference for the specification in g/m3 is the molar volume at 20 °C
Bibliographic data
Author Nabert, K.; Schön, G.
Year 1963
Title Sicherheitstechnische Kennzahlen brennbarer Gase und Dämpfe (mit 6. Nachtrag)
Publisher Deutscher Eichverlag
Publisher City Braunschweig
Abstract English Safety values of about 1000 flammable gases and vapors: Explosion limits, ignition temperatures, flash points, explosion pressures.
Language GERM
2 1941 Berger, H. 1.4 Vol% UTI: 15-647-5157/0-39
UTI: 15-647-5157/0-39;
Line no Lower explosion limit
  • property of pure substance
1 1.4 Vol%
Bibliographic data
Title Brennbare Gase, Flüssigkeiten und feste Stoffe
Author Berger, H.
Year 1941
Publisher Edmund Stein u. Co.
Publisher City Potsdam
Language GERM
3 1950 1.4 Vol% UTI: 1-647-5154/0-39
UTI: 1-647-5154/0-39;
Line no Lower explosion limit
  • property of pure substance
1 1.4 Vol%
Bibliographic data
Title Loss Prevention Bulletin No. 36.10: Properties of Flammable Liquids, Gases and Solids
Year 1950
Journal Title The Factory Mutual Engineering Division;Boston, Ma
Publisher The Factory Mutual Engineering Division
Publisher City Boston
Language ENGL
4 1994 1.4 Vol% UTI: 16-647-5160/0-39
UTI: 16-647-5160/0-39;
Line no Lower explosion limit
  • property of pure substance
1 1.4 Vol%
Bibliographic data
Year 1994
Title Fire-hazard Properties of certain Flammable Liquids, Gases and Volatile Solids
Publisher National Fire Protection Association
Publisher City Boston
Language ENGL
Stoichiometric fraction of combustible substance in mixture with air
1 2005 Physikalisch-Technische Bundesanstalt (PTB) 3.7 Mol% UTI: 220-647-5174/0-39
UTI: 220-647-5174/0-39;
Line no Stoichiometric fraction of combustible substance in mixture with air
  • recommended value
  • property of pure substance
1 3.7 Mol%
Bibliographic data
Author Physikalisch-Technische Bundesanstalt (PTB)
Year 2005
Title Berechnete molare stöchiometrische Brenngasanteile in Luft (c_stoech)
Database PTB
Publisher Datenbank PTB-Lab. 3.43
Language GERM

No entry in database