Apparatus Groups

Gas Groups Dust Groups
IIA Propane IIIA Combustible
IIB EthyleneIIIB Non-conductive
IIC Hydrogen / Acetylene IIIC Conductive

Common flammable gases, vapours and dust types

Gas Vapour Temperature
 class
Apparatus group Typical ignition
temperature (°C)
Acetic acid
T1IIA427
AcetoneT1IIA465
Acetylene
T2IIC305
Ammonia
T1IIA651
ButaneT2IIA405
Carbon DisulphineT6IIC95
CyclohexaneT3IIA245
Di-ethyl etherT4IIB160
Ethanol (ethyl alcohol)T2IIA365
EthyleneT2IIB490
Gasoline (petrol)T3IIA280
HydrogenT1IIC500
KeroseneT3IIA295
Methane (natural gas) (non-mining)T1IIA580
Methanol (methyl alcohol)T2IIA470
Methyl ethyl ketone (MEK)T2IIB505
PropaneT1IIA470
Propan-1-ol (n-propyl alcohol)T2IIB371
Propan-2-ol (iso-propyl alcohol)
T2IIA399
TolueneT1IIA535
XyleneT1IIA463


Dusts Apparatus group
Typical ignition 
temperature
cloud (°C)

Typical ignition
temperature
layer (°C)
Aluminium
IIIC590>450
Coal dust (lignite)IIIB380225
FlourIIIB490340
Grain dustIIIB510300
Methyl celluloseIIIB420320
Phenolic resinIIIB530>450
PolytheneIIIB420(melts)
PVCIIIB700>450
SootIIIB810570
StarchIIIB460435
SugarIIIB490460