ABSTRACT
The safety and economic impact of unintentional ignition of explosive mixtures is something that should
never be underestimated when processing, storing, generating or transporting combustible liquids, gases or
dusts. Where hazardous atmospheres can exist, electricity should be a primary concern of every engineer and
system designer. Hazardous atmospheres can exist not only in the more common surroundings of industrial,
chemical, and environmental facilities, but also in many less obvious environs where dust is present, where gas
can accumulate, and where combustible gas-forming reactions occur. To minimize risks in such areas, it is
necessary to design specific hazard-reducing electrical systems. Most electrical equipment is built to specific
standards aimed to reduce the incidence of fires and human casualties. The majority of such incidents can be
attributed to poor or defective installations, improper use of approved equipment, deteriorated equipment,
and accidental applications. In combination with an explosive atmosphere, these factors can result in
extremely dangerous conditions. Designing an electrical system for a hazardous location requires careful
planning, research, engineering, and ingenuity in using proper protection techniques to develop better
applications and classifications that reduce hazards.
