Hazardous Areas Classification - North America

Hazardous Areas Classification

Electrical equipment installation in atmosphere with flammable gases or vapors, flammable liquids, combustible dusts, ignitable fibers or flyings represents a risk for fire and explosion.

Areas with possible fire or explosion risks due to explosive atmospheres and/or mixtures - are called hazardous (or classified) locations or areas. These areas are in North America (United States and Canada) historically classified with the Class/Division system. In Europe and the rest of the world - but also more and more in North America - the Zone system is used.

The hazardous area classification system determines required protection techniques and methods for electrical installations in the location.  

Class/Division System

The Class/Division/Group system is based on Article 500 of the National Electrical Code (NEC) where

Classes - defines the general nature of the hazardous material in the surrounding atmosphere

Divisions - defines the probability of hazardous material being present the surrounding atmosphere

Groups - defines the type of the hazardous material in the surrounding atmosphere