The hazardous locations covered by Chapter 5 of the National Electrical Code (NEC) are classified in accordance with the properties of flammable liquids, gases, vapors, combustible dust, or ignitable fibers or flyings that may be present in the area where electrical equipment may be installed.
Jim Dollard has an extensive background in codes and standards. If you have a query about the National Electrical Code (NEC), Jim will help you solve it. Questions can be sent to firstname.lastname@example.org. Answers are based on the 2014 NEC. Listed luminaire?