Razlika med eksplozijsko varnimi stopnjami IIB in IIC

Explosion-proof equipment within Class II is categorized into: Class IIA, Class IIB, and Class IIC. The ratings follow a hierarchy: IIC > IIB > IIA.

Kategorija stanja	Razvrstitev plinov	Reprezentativni plini	Najmanjša energija vžiga
Pod rudnikom	I	Metan	0,280 mJ
Tovarne zunaj rudnika	IIA	Propan	0,180 mJ
	IIB	Etilen	0,060 mJ
	IIC	Vodik	0,019 mJ

Gas detectors rated for IIC explosion-proof conditions are suitable for all flammable gases; however, IIB detectors fail to detect H2 (hydrogen), C2H2 (acetylene), and CS2 (carbon disulfide), which are characteristic of the IIC class.