A location in which the fire or explosion hazard exists infrequently and for short periods is designated as a Division 2 or Zone 2 location. Two of the primary protection techniques for Division 2 or Zone 2 locations are "Nonincendive equipment" or "Non-sparking equipment". This Technical Report is intended to explain these protection techniques and to clarify the associated terminology. This Technical Report also addresses field wiring for Division 2/Zone 2 locations.

This recommended practice is intended to promote the uniform installation of intrinsically safe
systems for hazardous (classified) locations. Information is provided to clarify and explain the
requirements of Articles 504 and 505 of the National Electrical Code® ANSI/NFPA 70.

This standard provides minimum requirements for the design, construction, and marking of electrical equipment or parts of such equipment for use in Class I and Class II, Division 2 and Class III, Divisions 1 and 2 hazardous (classified) locations.

This equipment, in normal operation, is not capable of causing ignition of the surrounding atmosphere under the conditions prescribed in this standard, although the equipment may contain electronic components used in an incendive circuit and may also have field wiring that is an incendive circuit.

In addition, it is the intent of this document to establish uniformity in test methods for determining the suitability of the equipment and associated circuits and components as they relate to potential ignition of a specific flammable gas or vapour-in-air mixture, combustible dust, easily ignitible fibers, or flyings.

This standard applies to both body-worn and hand-held portable electronic products for use in Class I and II, Division 2, Class I, Zone 2, and Class III, Division 1 and 2 Hazardous (Classified) Locations which are not available listed or labeled for hazardous (classified) locations.