What Does Explosion-Proof Level ABC Mean

Der “abc” represents gas classifications, categorized into three levels—IIA, IIB, and IIC—according to the maximum experimental safe gap (MESG) or the minimum igniting current (MIC).

Zustandskategorie	Gasklassifizierung	Repräsentative Gase	Minimale Zündfunkenenergie
Unter der Mine	ICH	Methan	0.280mJ
Fabriken außerhalb der Mine	IIA	Propan	0.180mJ
	IIB	Ethylen	0.060mJ
	IIC	Wasserstoff	0.019mJ

Of these, the IIC classification is deemed the most hazardous, with IIB and IIA following in decreasing order of risk. Gases falling under the IIC classification include hydrogen, Acetylen, carbon disulfide, ethyl nitrate, and water gas. Those in the IIB category encompass ethylene, coke oven gas, propyne, and hydrogen sulfide. The IIA classification includes gases such as methane, ethane, Benzol, and diesel.