Hazardous Area Classification

Hazardous Area Classification is the process of identifying and defining locations where explosive atmospheres — formed by flammable gases, vapours, mists, or combustible dusts — may be present, and classifying those locations into zones based on the frequency and duration of the explosive atmosphere. The classification determines the type of electrical and non-electrical equipment that may be safely used in each zone.

In India, hazardous area classification is carried out in accordance with IS 5572 and other applicable Indian Standards — aligned with international standards such as IEC 60079. The classification process involves a systematic review of the flammable materials present, their properties and release sources, ventilation conditions, and the extent of hazardous zones — resulting in area classification drawings and equipment selection schedules. It is a fundamental requirement for facilities handling flammable liquids, gases, and dusts — including petrochemical plants, refineries, paint manufacturing, pharmaceutical facilities, flour mills, and any process where an explosive atmosphere could form — and is essential for ensuring the safety of electrical installations and preventing ignition of explosive atmospheres.