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CAS Number: 624-83-9
Sum Formula: C2H3NO
Molar Mass: 57.1 g/mol
German Synonyms: Methylisocyanat | Methylcarbimid | Isocyanatomethan
English Synonyms: Methyl isocyanate | Isocyanatomethane
EC Index Number: 615-001-00-7
EC Number: 210-866-3
Properties: Extremely toxic, Reacts with water
Temperature Class: T1
Explosion Group: IIA
Structural Formula Isocyanatomethane

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. 2: flammable liquids, category 2
  • Repr. 2: toxic to reproduction, category 2
  • Acute Tox. 2: acute toxicity by inhalation, category 2
  • Acute Tox. 3: acute dermal toxicity, category 3
  • Acute Tox. 3: acute oral toxicity, category 3
  • STOT SE 3: Specific target organ toxicity following single exposure, category 3, respiratory tract irritation or narcotic effects
  • Skin Irrit. 2: skin irritation, category 2
  • Eye Dam. 1: serious eye damage, category 1
  • Resp. Sens. 1: respiratory sensitizer, category 1
  • Skin Sens. 1: skin sensitization, category 1
GHS Pictogram:
pictogram flammable
pictogram toxic
pictogram toxic
pictogram health hazard
pictogram corrosive





GHS Signal Word: Danger
GHS Hazard Statement:
  • H225: Highly flammable liquid and vapour.
  • H361: Suspected of damaging fertility or the unborn child .
  • H330: Fatal if inhaled.
  • H311: Toxic in contact with skin.
  • H301: Toxic if swallowed.
  • H335: May cause respiratory irritation.
  • H315: Causes skin irritation.
  • H318: Causes serious eye damage. (not needed beside H314)
  • H334: May cause allergy or asthma symptoms or breathing difficulties if inhaled.
  • H317: May cause an allergic skin reaction.

Antoine parameters
1 DECHEMA 7.0902 Torr UTI: 1100-1535-23347/0-39
UTI: 1100-1535-23347/0-39;
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 < 67 °C > -43 °C 216.84 °C 1077.211 °C 7.0902 Torr
Bibliographic data
Author DECHEMA
Title Antoinekonstanten
Database PTB
Publisher Detherm
Boiling point
1 1963 Nabert, K.; Schön, G. 1013.25 hPa 38 °C UTI: 1000-1535-23342/0-39
UTI: 1000-1535-23342/0-39;
Line no Boiling temperature Pressure
  • defined value
  • at atmospheric pressure
  • property of pure substance
1 ca. 38 °C ca. 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 1963 Nabert, K.; Schön, G. 1013.25 hPa 20 °C 0.96 g/cm3 UTI: 1000-1535-23343/0-39
UTI: 1000-1535-23343/0-39;
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 0.96 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
Relative gas density
1 1963 Nabert, K.; Schön, G. 1.97 UTI: 1000-1535-23344/0-39
UTI: 1000-1535-23344/0-39;
Line no Relative gas density
  • defined value
  • property of pure substance
1 1.97
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) 20 °C 67 g/l UTI: 228-1535-23339/0-39
UTI: 228-1535-23339/0-39;
Line no Solubility in water Temperature
  • defined value
  • property of pure substance
  • property of pure substance
1 67 g/l 20 °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. 530 °C UTI: 1000-1535-23346/0-39
UTI: 1000-1535-23346/0-39;
Line no Autoignition Temperature
  • recommended value
  • international standard method
  • property of pure substance
1 530 °C [A]
[A] IEC 79-4: Method of Test for Ignition Temperature, Electrical Apparatus for Explosive G; Replaced by IEC-60079-20-1 in 1975
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
Flash point
1 1991 Physikalisch-Technische Bundesanstalt (PTB) -35 °C UTI: 4801-1535-23348/0-39
UTI: 4801-1535-23348/0-39;
Line no Flash point
  • recommended value
  • estimated
  • closed cup
  • property of pure substance
1 -35 °C
Bibliographic data
Author Physikalisch-Technische Bundesanstalt (PTB)
Year 1991
Title Empfohlene Sicherheitstechnische Kenngrößen
Database PTB
Publisher Datenbank PTB-AG 3.41/3.71
Language GERM
2 1963 Nabert, K.; Schön, G. < 0 °C UTI: 1000-1535-23345/0-39
UTI: 1000-1535-23345/0-39;
Line no Flash point
  • closed cup
  • property of pure substance
1 < 0 °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
Maximum experimental safe gap
1 2020 DIN EN ISO/IEC 1.21 mm UTI: 241-1535-23340/0-39
UTI: 241-1535-23340/0-39;
Line no Maximum experimental safe gap
  • recommended value
  • property of pure substance
1 1.21 mm
Bibliographic data
Author DIN EN ISO/IEC
Year 2020
Title DIN EN ISO/IEC 80079-20-1 :2020-09
Subtitle Explosive atmospheres - Part 20-1: Material characteristics for gas and vapour classification - Test methods and data
Publisher Beuth
Publisher City Berlin
Stoichiometric fraction of combustible substance in mixture with air
1 2005 Physikalisch-Technische Bundesanstalt (PTB) 8.5 Mol% UTI: 220-1535-23338/0-39
UTI: 220-1535-23338/0-39;
Line no Stoichiometric fraction of combustible substance in mixture with air
  • recommended value
  • property of pure substance
1 8.5 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