Hazardous Location Lighting

Hazardous location lighting, sometimes called explosion proof lighting, is engineered to prevent the ignition of explosive gasses, vapors, or dust in hazardous environments. These fixtures use robust materials and sealed enclosures to contain possible sparks or flames, ensuring safety in industries such as oil and gas, chemical processing, and manufacturing.

The National Electrical Code (NEC) classifies hazardous environments based on the presence of flammable substances, defining safety standards for lighting fixtures to prevent fires or explosions.

The NEC categorizes areas using two main systems:

• Class I, Division 1: Explosive gasses/vapors are present during normal operations.
• Class I, Division 2: Such gasses/vapors may exist only under abnormal conditions.
• Class II, Division 1: Combustible dust is present during normal conditions.
• Class II, Division 2: Dust is typically absent during normal operations.
• Class III, Division 1: Nonmetal fibers/flyings are present under normal conditions.
• Class III, Division 2: These materials are stored or handled, not actively manufactured.

• Zones 0, 1, 2: For gasses/vapors ranging from continuous (Zone 0) to rare exposure (Zone 2).
• Zones 20, 21, 22: Dusts and fibers are classified similarly based on exposure frequency from continuous (Zone 20) to rare exposure (Zone 22).

Temperature classifications indicate the maximum surface temperature of equipment under standard conditions (40°C or 104°F). These classifications ensure equipment remains below the ignition point of hazardous materials. Examples include:

• T1 Class: 450°C (842°F)
• T2 Class: 300°C (572°F)
• T3 Class: 200°C (392°F)
• T4 Class: 135°C (275°F)
• T5 Class: 100°C (212°F)
• T6 Class: 85°C (185°F)

The Occupational Safety and Health Administration (OSHA) further classifies hazardous locations into groups based on the properties of substances:

• Class I Groups A-D: For gasses like acetylene (A), hydrogen (B), ethylene (C), and propane (D).
• Class II Groups E-G: For dusts including metal dusts (E), carbon dusts (F), and non-conductive dusts like wood or grain (G).

When choosing LED lighting for hazardous areas, it is crucial to look for certifications demonstrating compliance with industry standards. 

Key certifications include:

• UL (Underwriters Laboratories): Certifies products for safety and performance in hazardous locations in North America.

• CSA (Canadian Standards Association): Provides certification for safety compliance in Canadian markets.

• IECEx (International Electrotechnical Commission System for Certification to Standards Relating to Equipment for Use in Explosive Atmospheres): A global certification system for ensuring that products meet IEC standards for hazardous locations.

• ATEX (Atmosphères Explosibles): The European Union’s certification directive that indicates compliance with safety standards for equipment used in explosive atmospheres.

Explosion-proof lights must be certified to match the specific class, division, group, or zone where they will be installed, ensuring safe and compliant operation.