Class I, Division 1 locations are those in which ignitible concentrations of _____ can exist under normal operating conditions.
a) combustible dust
b) easily ignitible fibers or flyings
c) flammable gases or flammable liquid produced vapors
d) pyrotechnics
See answer and applicable Code reference
The correct answer is: c) flammable gases or flammable liquid produced vapors
Article 500 outlines the requirements for hazardous (classified) locations, Classes I, II, and III, Divisions 1 and 2. A Class I, Division 1 location is defined in Sec. 500.5(B)(1)(1). More specifically, it notes that a Class I, Division 1 location is a location "in which ignitible concentrations of flammable gases, flammable liquid-produced vapors, or combustible liquid-produced vapors can exist under normal operating conditions."
