This revised edition provides the basics of applying hazard and operability study (Hazop) and hazard analysis (Hazan). Hazop is a creative but systematic method of identifying hazards in process plants. Hazard analysis is then used to quantify the risks from these hazards, and to assess how far to go in reducing them. This book is presented in easy-to-read style and explains: what a Hazop is, who carries it out, when, and how long it should take; points to watch during a Hazop; an example of a Hazop; Hazops on flowsheets; the stages of Hazard analysis; the Fatal Accident Rate; risks to the public; estimating how often an accident will occur, with examples; and pitfalls in Hazan.