Explosion proof lighting classification

Explosion-proof lighting is specifically designed to operate safely in hazardous environments where flammable gases, vapors, dust, or fibers are present. Its classification system ensures that the correct lighting is used for various hazardous scenarios, based on the risks and regulatory standards.

Hazardous Area Classification

1. NEC Classification (USA and Canada)

Class: Identifies the type of hazardous material present:

Class I: Flammable gases, vapors, or liquids (e.g., propane, hydrogen).
Class II: Combustible dust (e.g., coal dust, grain dust).
Class III: Ignitable fibers or flyings (e.g., wood shavings, textiles).

Division: Indicates the frequency or likelihood of the hazard:

Division 1: Hazard is present during normal operation.
Division 2: Hazard is present only in abnormal conditions.

Groups: Sub-classifies materials within each Class:

Group E: Combustible metal dust (e.g., aluminum).
Group F: Combustible carbonaceous dust (e.g., coal).
Group G: Other combustible dust (e.g., flour, grain).
Group A: Acetylene
Group B: Hydrogen or gases of equivalent hazard
Group C: Ethylene or gases of equivalent hazard
Group D: Propane or gases of equivalent hazard
Class I Groups:
Class II Groups:

2. IEC/ATEX Classification (International)

Zones: Based on the likelihood of the presence of hazardous substances:

Zone 20: Continuous presence of combustible dust.
Zone 21: Likely presence during normal operation.
Zone 22: Likely presence only during abnormal conditions.
Zone 0: Continuous presence of explosive gas atmosphere.
Zone 1: Likely presence during normal operation.
Zone 2: Likely presence only during abnormal conditions.
Gas Zones:
Dust Zones:

Gas Groups: Similar to NEC Class I Groups:

IIC: Acetylene, hydrogen (most hazardous).
IIB: Ethylene, industrial gases.
IIA: Propane, butane.

Temperature Classes (T-Ratings):

T1: ≤ 450°C
T2: ≤ 300°C
T3: ≤ 200°C
T4: ≤ 135°C
T5: ≤ 100°C
T6: ≤ 85°C
Defines the maximum surface temperature of equipment:

Product category

Explosion proof lighting classification

Applications by Classification

Class I, Division 1 / Zone 0, 1:

Oil and gas rigs, chemical plants, fuel storage facilities.

Class II, Division 1 / Zone 20, 21:

Grain elevators, food processing, coal mines.

Class III, Division 1:

Textile mills, woodworking plants.

Zone 2 / Division 2:

Gas pipelines, storage areas, and maintenance zones.

Key Standards for Explosion-Proof Lighting

NEC (National Electrical Code) – North America

Defines hazardous areas using Classes, Divisions, and Groups.

IEC (International Electrotechnical Commission)

Uses a Zone system to define hazardous locations.

ATEX (Atmosphères Explosibles)

A European directive that aligns closely with the IEC Zone system.

UL (Underwriters Laboratories) and CSA (Canadian Standards Association)

Certify products for safety in hazardous areas.

Explosion-proof lighting classification ensures safety and compliance in hazardous areas. Understanding the distinctions between NEC and IEC/ATEX systems is crucial for selecting the appropriate lighting solutions for specific environments. Always prioritize certified equipment to maintain operational safety.