Explosion Proof Lighting

Explosion proof lighting classifications

Explosion proof lighting classifications categorize fixtures for hazardous environments prone to explosions due to flammable gases, vapors, combustible dust, or ignitable fibers. National Electrical Code (NEC) in the United States classifications explosion proof / hazardous areas by class and divisions. In Europe and other parts of the world, explosion-proof lighting is classified according to a zone system defined by the ATEX (ATmosphères EXplosibles) directive or IECEx (International Electrotechnical Commission Explosive) standards.

These classifications guide the design and selection of explosion proof lighting fixtures to ensure safety and regulatory compliance.

NEC Division System Gas & Dust Groups

Area	Group	Representative Materials
Class I, Division 1 & 2	A	Acetylene
	B	Hydrogen, butadiene, ethylene oxide, propylene oxide and acrolein
	C	Ethylene, cyclopropane and ethyl ether
	D	Acetone, ammonia, benzene, butane, ethanol, gasoline, hexane, methane, methanol, methane, naphtha, natural gas, propane and toluene
Class II, Division 1 & 2	E (Div. 1 only)	Combustible metal dusts: aluminum, commercial alloys and magnesium
	F	Combustible carbonaceous dusts: carbon black, charcoal, coal and coke dusts
	G	Non-Conductive Dusts (flour, grain, wood, plastic, etc.)
Class III, Division 1 & 2	None	Ignitible fibers/flyings, such as cotton lint, flax & rayon

NEC & IEC Zone System Gas & Dust Groups

Area	Group	Representative Materials	Equivalent to NEC
Zone 0, 1 & 2	II C	Acetylene & Hydrogen	Class I, Groups A and B
	II B + H2	Hydrogen	Class I, Group B
	II B	Ethylene	Class I, Group C
	II A	Propane	Class I, Group D
Zone 20, 21 & 22	III C	Conductive dusts, such as magnesium	Glass II, Group E
	III B	Non-conductive dusts, such as flour, grain, wood & plastic	Class II, Groups F and G
	III A	Ignitible fibers/flyings, such as cotton lint, flax & rayon	Class III
Mines susceptible to firedamp	I (IEC only)	Methane