CH3F Methyl fluoride (R41) CAS Number : 593-53-3 UN2454 Gas PropertiesMolecular WeightMolecular weight  : 34.03 g/molCritical pointCritical temperature  : 45 °CCritical pressure  : 58.76 barGaseous phaseSpecific gravity (air = 1) (1.013 bar and 21 °C (70 °F)) : 1.195 Specific volume (1.013 bar and 21 °C (70 °F)) : 0.709 m3/kg