The book portrays with an understanding of the hazards involved in using of electrical equipments in hazardous locations like petroleum industry, petrochemical, refinery, bottling plant, petrol pump, pumping station, marketing terminal etc.This book is helpful for everyone who is engaged in maintenance, operation, design, installation, commissioning, inspection and audit etc. of hazardous industry.It is assumed that reader should not require any previous knowledge of hazardous industry. It is useful for the beginners of any discipline like civil, mechanical, electrical, chemical, instrumentation from technicians, engineers to plant managers.