The Difference Between Explosion-Proof Levels IIC and IIIC

These represent completely distinct concepts.

Condition Category	Gas Classification	Representative gases	Minimum Ignition Spark Energy
Under The Mine	I	Methane	0.280mJ
Factories Outside The Mine	IIA	Propane	0.180mJ
	IIB	Ethylene	0.060mJ
	IIC	Hydrogen	0.019mJ

IIC is typically associated with explosion-proof environments, characterized by substances such as hydrogen and ethyl nitrate. Conversely, IIIC, as defined by national standards, pertains to conductive dust explosions, designated as DIP A21. IIIA covers flammable fibers, and IIIB encompasses non-conductive dust.

IIC is not interchangeable with IIIC; therefore, products with dust explosion-proof ratings such as DIP A20/A21 should be chosen.