What is Class 1 Division 2 Lighting?
The “Class” categorization, defined by the NEC, refers to the type of fuel that is present in an environment. Class 1 covers flammable gases and liquids, Class 2 covers combustible dusts and Class 3 refers to fibers and filings as found in the textile and woodworking industries. Divisions, on the other hand, refer to the severity of the environment. Division I is the most severe environment, as the hazardous atmosphere is always or often present, or becomes present during frequent servicing /repair. With Division 2, the hazardous atmosphere is only available infrequently, for instance in the case of an accidental spill or the failure of a mechanical positive ventilation system. It includes storage/handling facilities, where the fuel is kept in sealed containers or closed systems. This division can also be found adjacent to Division I areas, where the fuel might occasionally be communicated. A Class 1 Division 2 light (C1D1 lighting), based on these definitions, would meet the requirements to be safe around flammable gases and liquids in an environment where the hazardous atmosphere is only available infrequently.
What makes Class 1 Division 2 Lighting Acceptable?
The “Class” categorization, defined by the NEC, refers to the type of fuel that is present in an environment. Class 1 covers flammable gases and Protection for Class I Div. II devices are handled differently based on the device. Acceptable devices include:
- Products listed for Class I Division I
- Nationally Recognized Testing Laboratory (NRTL)-listed devices that meet the specific features described by the NEC for Div II installations. For instance, fixtures must be designed to contain arcing and sparking. Also, other construction requirements/tests must be done to determine the maximum operating temperature of every surface of the fixture, inside and out, and then the fixtures must be labeled with the maximum operating temperature or the Temperature Range Code and the maximum ambient temperature (room temperature).
- The NEC still allows “enclosed and gasketed” or “vapor tight” fixtures, but regulatory agencies have all but eliminated this in practice.