How to Classify Explosion-Proof Levels

Explosive gas environments are categorized into three levels—A, B, and C—based on the maximum experimental safe gap or the minimum ignition current required.

Class And Level	Ignition Temperature And Group
-	T1	T2	T3	T4	T5	T6
-	T＞450	450≥T＞300	300≥T＞200	200≥T＞135	135≥T＞100	100≥T＞85
I	Methane
IIA	Ethane, Propane, Acetone, Phenethyl, Ene, Aminobenzene, Toluene, Benzene, Ammonia, Carbon Monoxide, Ethyl Acetate, Acetic Acid	Butane, Ethanol, Propylene, Butanol, Acetic Acid, Butyl Ester, Amyl Acetate Acetic Anhydride	Pentane, Hexane, Heptane, Decane, Octane, Gasoline, Hydrogen Sulfide, Cyclohexane, Gasoline, Kerosene, Diesel, Petroleum	Ether, Acetaldehyde, Trimethylamine		Ethyl Nitrite
IIB	Propylene, Acetylene, Cyclopropane, Coke Oven Gas	Epoxy Z-Alkane, Epoxy Propane, Butadiene, Ethylene	Dimethyl Ether, Isoprene, Hydrogen Sulfide	Diethylether, Dibutyl Ether
IIC	Water Gas, Hydrogen	Acetylene			Carbon Disulfide	Ethyl Nitrate

Devices are organized into six temperature classifications, ranging from T1 to T6, determined by the maximum allowable surface temperature.