HAZOP Study- A primer for technical professionals


Miami, Jan 29, 2011 – This article will present some information about HAZOP (acronym that stands for Hazard and Operability Study) that is used in process plants such as Oil and Gas facilities, chemical plants, power plants and similar installations,  to assess the safety aspects of the plant and related facilities.

If you would like a more detailed coverage and training related to HAZOP, you can download the HAZOP Training Course from here.

HAZOP is a technique that started out circa 1960s as “efficiency” studies in ICI (Imperial Chemical Industries) in the UK. At that time it was the rage to do efficiency and productivity studies on various operations in different kinds of industries (it was the golden era of Industrial Engineering) and some bright spark decided to try it out on a spanking new design of a phenol plant was on the design board.

Well, he opened a can of worms, as it were, because the efficiency improvement study found several holes in operational safety as well and the technique of HAZOP was born. Inititally it was confined only to ICIs internal departments, but later on it spread via conferences and papers to other companies as well and soon became an established safety technique.

The Bhopal incident that happened two decades later was a wake up call to the global chemicals and process industries and HAZOP began to be used not only for new plants at the design stage but also for older plants, modifications, shutdowns and turnarounds and so on. The process not only improved Safety but also operational ease.

In the typical HAZOP methodology, a plant or a subsystem of the plant (called a node) is chosen for study. Then all deviations are studied against the original intentions and permutations and combinations give rise to possibilities that can result in accidents. These are then assessed to modify the design or the workflow,  so that the process becomes safer. Of course there is much more to this and it requires training in the technique plus a few real life HAZOP studies to really master the technique.

Today one cannot think of not using HAZOP in a process plant, it has become ubiquitous. However being subjective, the result of the HAZOP study depends greatly on the people that comprise the team carrying it out and a bad HAZOP from a bad team results in the plant being even more unsafe than had there been no HAZOP at all! As we always say, incompetence is worse than malfeasance, because malicious people will behave in certain predictable ways, but incompetent people can be incompetent and stupid in several ways that can never be thought of by the rest of humanity. So it is very important that only trained and competent people are in charge of HAZOPs. The below video summarizes HAZOP quite nicely.