UL844 Certification: Quick Guide to North American Explosion Proof Lighting Standard

1.What Is UL844 Certification?

UL844 is the core standard for luminaires used in hazardous locations in North America. Issued by Underwriters Laboratories (UL), its full name is “Luminaires for Use in Hazardous (Classified) Locations”.
This standard works closely with the National Electrical Code (NEC) in the US and the Canadian Electrical Code (CEC). It ensures that explosion proof lights can operate safely in environments containing flammable gases, vapors, combustible dust, or ignitable fibers without becoming an ignition source.
In simple terms: If you are installing lighting in petroleum, chemical, mining, grain storage, or other hazardous areas in the United States or Canada, UL844 certification is usually mandatory.

2.Where Is UL844 Mainly Applied?

UL844 is the primary certification standard for hazardous location lighting in the United States and Canada. It is widely required for industrial projects across North America.
Although it is not a global voluntary system like IECEx, UL844 (including the cUL mark for Canada) is the essential certification for entering the North American market. Many international manufacturers apply for UL844 to access US and Canadian projects, especially in oil & gas, petrochemical, and heavy industry sectors.
Note: UL844 uses the North American Class/Division/Group classification system, which is different from the Zone system used in ATEX and IECEx.

3.UL844 Hazardous Location Classification (Class/Division)

UL844 follows the NEC/CEC Class/Division classification system:
ClassMaterial TypeDivision 1 (High Risk)Division 2 (Lower Risk)Class IFlammable gases & vaporsHazard present during normal operationsHazard present only in abnormal conditionsClass IICombustible dustDust suspended during normal operationsDust accumulates but not normally airborneClass IIIIgnitable fibers & flyingsFibers present during normal operationsFibers handled/stored but not suspended
Each Class also has specific Groups (e.g., Group A, B, C, D for gases) based on the ignition properties of the substances.

4.Why Choose UL844 Certification?

North American market access: Essential requirement for projects in the US and Canada
Reliable safety performance: Rigorously tested for explosion containment, temperature rise, and durability
Project compliance: Required by project owners, insurers, and local authorities (AHJ)
Stronger competitiveness: Products with both UL844 + ATEX/IECEx are preferred by multinational companies

Summary: UL844 is the most important certification for explosion proof lighting in North America. It uses the Class/Division system to ensure safety in hazardous locations. For projects in the US or Canada, always prioritize UL844-certified explosion proof lights to meet local regulations and minimize safety risks.