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CAS Number: 123-31-9
Sum Formula: C6H6O2
Molar Mass: 110.1 g/mol
German Synonyms: p-Dioxybenzol | Hydrochinon | 1,4-Dihydroxybenzol | 1,4-Benzoldiol
English Synonyms: 1,4-Benzenediol
EC Index Number: 604-005-00-4
EC Number: 204-617-8
Temperature Class: T1
Structural Formula 1,4-Benzenediol

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:
  • Carc. 2: carcinogenicity, category 2
  • Muta. 2: germ cell mutagenicity, category 2
  • Acute Tox. 4: acute oral toxicity, category 4
  • Eye Dam. 1: serious eye damage, category 1
  • Skin Sens. 1: skin sensitization, category 1
  • Aquatic Acute 1: acute hazards to the aquatic environment, category 1
GHS Pictogram:
pictogram health hazard
pictogram corrosive
pictogram harmful
pictogram environmental hazard





GHS Signal Word: Danger
GHS Hazard Statement:
  • H351: Suspected of causing cancer .
  • H341: Suspected of causing genetic defects .
  • H302: Harmful if swallowed.
  • H318: Causes serious eye damage. (not needed beside H314)
  • H317: May cause an allergic skin reaction.
  • H400: Very toxic to aquatic life.

Boiling point
1 1941 Berger, H. 1013.25 hPa 285 °C UTI: 15-952-13200/0-39
UTI: 15-952-13200/0-39;
Line no Boiling temperature Pressure
  • defined value
  • at atmospheric pressure
  • saturated
  • property of pure substance
  • saturated
1 285 °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 285 °C UTI: 1-952-13190/0-39
UTI: 1-952-13190/0-39;
Line no Boiling temperature Pressure
  • defined value
  • at atmospheric pressure
  • saturated
  • property of pure substance
  • saturated
1 285 °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 1951 Oehley, E. 1013.25 hPa 286.2 °C UTI: 13-952-13196/0-39
UTI: 13-952-13196/0-39;
Line no Boiling temperature Pressure
  • defined value
  • at atmospheric pressure
  • saturated
  • property of pure substance
  • saturated
1 286.2 °C 1013.25 hPa
Bibliographic data
Title Stoffdaten
Author Oehley, E.
Year 1951
Publisher Farbwerke Hoechst, Techn. Abt. Farben-Gruppe
Language GERM
4 1963 Nabert, K.; Schön, G. 1013.25 hPa 286 °C UTI: 1000-952-13214/0-39
UTI: 1000-952-13214/0-39;
Line no Boiling temperature Pressure
  • defined value
  • at atmospheric pressure
  • property of pure substance
1 286 °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
Density
1 1941 Berger, H. 1013.25 hPa 20 °C 1.332 g/cm3 UTI: 15-952-13201/0-39
UTI: 15-952-13201/0-39;
Line no Density Temperature Pressure
  • defined value
  • at atmospheric pressure and room temperature
  • property of pure substance
  • at atmospheric pressure and room temperature
  • property of pure substance
  • at atmospheric pressure and room temperature
1 1.332 g/cm3 20 °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 20 °C 1.332 g/cm3 UTI: 1-952-13191/0-39
UTI: 1-952-13191/0-39;
Line no Density Temperature Pressure
  • defined value
  • at atmospheric pressure and room temperature
  • property of pure substance
  • at atmospheric pressure and room temperature
  • property of pure substance
  • at atmospheric pressure and room temperature
1 1.332 g/cm3 20 °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 1951 Oehley, E. 1013.25 hPa 20 °C 1.332 g/cm3 UTI: 13-952-13197/0-39
UTI: 13-952-13197/0-39;
Line no Density Temperature Pressure
  • defined value
  • at atmospheric pressure and room temperature
  • property of pure substance
  • at atmospheric pressure and room temperature
  • property of pure substance
  • at atmospheric pressure and room temperature
1 1.332 g/cm3 20 °C 1013.25 hPa
Bibliographic data
Title Stoffdaten
Author Oehley, E.
Year 1951
Publisher Farbwerke Hoechst, Techn. Abt. Farben-Gruppe
Language GERM
4 1963 Nabert, K.; Schön, G. 1013.25 hPa 20 °C 1.36 g/cm3 UTI: 1000-952-13215/0-39
UTI: 1000-952-13215/0-39;
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 1.36 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 1941 Berger, H. 170 °C UTI: 15-952-13199/0-39
UTI: 15-952-13199/0-39;
Line no Melting temperature
  • defined value
  • at atmospheric pressure
  • property of pure substance
1 170 °C
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 170 °C UTI: 1-952-13189/0-39
UTI: 1-952-13189/0-39;
Line no Melting temperature
  • defined value
  • at atmospheric pressure
  • property of pure substance
1 170 °C
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 1951 Oehley, E. 170 °C UTI: 13-952-13195/0-39
UTI: 13-952-13195/0-39;
Line no Melting temperature
  • defined value
  • at atmospheric pressure
  • property of pure substance
1 170 °C
Bibliographic data
Title Stoffdaten
Author Oehley, E.
Year 1951
Publisher Farbwerke Hoechst, Techn. Abt. Farben-Gruppe
Language GERM
4 1963 Nabert, K.; Schön, G. 1013.25 hPa 170 °C UTI: 1000-952-13218/0-39
UTI: 1000-952-13218/0-39;
Line no Melting temperature Pressure
  • defined value
  • at atmospheric pressure
  • saturated
  • property of pure substance
  • recommended value
  • at atmospheric pressure
  • saturated
1 170 °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. 3.81 UTI: 15-952-13202/0-39
UTI: 15-952-13202/0-39;
Line no Relative gas density
  • defined value
  • property of pure substance
1 3.81
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 3.81 UTI: 1-952-13192/0-39
UTI: 1-952-13192/0-39;
Line no Relative gas density
  • defined value
  • property of pure substance
1 3.81
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. 3.81 UTI: 1000-952-13216/0-39
UTI: 1000-952-13216/0-39;
Line no Relative gas density
  • defined value
  • property of pure substance
1 3.81
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
Solubility in water
1 2009 Physikalisch-Technische Bundesanstalt (PTB) 25 °C 70 g/l UTI: 228-952-13211/0-39
UTI: 228-952-13211/0-39;
Line no Solubility in water Temperature
  • defined value
  • property of pure substance
  • property of pure substance
1 70 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

Autoignition Temperature
1 1963 Nabert, K.; Schön, G. 515 °C UTI: 1000-952-13217/0-39
UTI: 1000-952-13217/0-39;
Line no Autoignition Temperature
  • recommended value
  • according to german standard
  • property of pure substance
1 515 °C [A]
[A] DIN 51794: Testing of mineral oil hydrocarbons - Determination of ignition temperature; measurements are technically identical to those of ISO/IEC 80079-20-1 but results are treated differently.
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 1950 516 °C UTI: 1-952-13194/0-39
UTI: 1-952-13194/0-39;
Line no Autoignition Temperature
  • methode not internationally standardized
  • property of pure substance
1 516 °C
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
Flash point
1 1963 Nabert, K.; Schön, G. 165 °C UTI: 1000-952-13212/0-39
UTI: 1000-952-13212/0-39;
Line no Flash point
  • recommended value
  • experimental
  • closed cup
  • property of pure substance
1 165 °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. 165 °C UTI: 15-952-13203/0-39
UTI: 15-952-13203/0-39;
Line no Flash point
  • closed cup
  • property of pure substance
1 165 °C
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 165 °C UTI: 1-952-13193/0-39
UTI: 1-952-13193/0-39;
Line no Flash point
  • closed cup
  • property of pure substance
1 165 °C
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 1951 Oehley, E. 165 °C UTI: 13-952-13198/0-39
UTI: 13-952-13198/0-39;
Line no Flash point
  • property of pure substance
1 165 °C
Bibliographic data
Title Stoffdaten
Author Oehley, E.
Year 1951
Publisher Farbwerke Hoechst, Techn. Abt. Farben-Gruppe
Language GERM
Stoichiometric fraction of combustible substance in mixture with air
1 2005 Physikalisch-Technische Bundesanstalt (PTB) 3.1 Mol% UTI: 220-952-13210/0-39
UTI: 220-952-13210/0-39;
Line no Stoichiometric fraction of combustible substance in mixture with air
  • recommended value
  • property of pure substance
1 3.1 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