This book describes the application of major safety reviews used in the process industries (principally petroleum, petrochemical, chemical industries, nuclear installations, utility systems, and medical facilities). It provides guidance on qualitative hazard analyses, specifically for PHA (Preliminary Hazard Analysis), What-If, and HAZOP (Hazard and Operability) for review teams. OSHA and EPA as well as national governments all over the world, require industry to conduct these reviews to help prevent major catastrophic fire, explosions and oil spillages.