usually includes the following locations:

(1) Where volatile flammable liquids or liquefied flam- mable gases are transferred from one container to another

(2) Interiors of spray booths and areas in the vicinity of

spraying and painting operations where volatile
flammable solvents are used

(3) Locations containing open tanks or vats of volatile

gas, flammable liquid-produced vapor, combustible-liquid
flammable liquids

(4)

partments for the evaporation

produced vapors, combustible dusts, or fibers/flyings

that may be present, and the likelihood that a flammable
or combustible concentration or quantity is present.
Where pyrophoric materials are the only materials used
or handled, these locations shall not be classified. Each
room, section, or area shall be considered individually in
determining its classification.
FPN: Through the exercise of ingenuity in the layout of electrical installations for hazardous (classified) locations, it is frequently possible to locate much of the equipment in a reduced level of classification or in an
Drying rooms or com
of flammable solvents

(5) Locations containing fat- and oil-extraction equipment using volatile flammable solvents

(6) Portions of cleaning and dyeing plants where

flammable liquids are used

(7) Gas generator rooms and other portions of gas manufacturing plants where flammable gas may escape

(8) Inadequately ventilated pump rooms for flammable gas or for volatile flammable liquids

The interiors of refrigerators and freezers in which volatile flammable materials are stored in open, lightly stoppered, or easily ruptured
containers (10) All other locations where ignitible concentrations of flammable vapors or gases are likely to occur in the course of normal operations
FPN No. 2: In some Division 1 locations, ignitible concen- trations of flammable gases or vapors may be present continuously or for long periods of time. Examples include the following:

(1) The inside of inadequately vented enclosures containing instruments normally venting flammable gases or vapors to the interior of the enclosure

(2) The inside of vented tanks containing volatile flam- mable liquids

(3) The area between the inner and outer roof sections

of a floating roof tank containing volatile flammable
fluids

(4) Inadequately ventilated areas within spraying or coating operations using volatile flammable fluids

(5) The interior of an exhaust duct that is used to vent ignitible concentrations of gases or vapors

Experience has demonstrated the prudence of avoiding the installation of instrumentation or other electrical equipment in these particular areas altogether or where it cannot be avoided because it is essential to the process and other locations are not feasible [see 500.5(A), FPN] using electrical equipment or instrumentation approved for the specific application or consisting of intrinsically safe systems as described in Article 504.

(2) Class I, Division 2. A Class I, Division 2 location is a location

(1) In which volatile flammable gases, flammable liquid- produced vapors, or combustible liquid-produced va- pors are handled, processed, or used, but in which the liquids, vapors, or gases will normally be confined within closed containers or closed systems from which they can escape only in case of accidental rupture or breakdown of such containers or systems or in case of abnormal operation of equipment, or
(2) In which ignitible concentrations