PHA-Process Hazard Analysis

Today, we will examine in brief what is referred to in industry parlance as PHA or Process Hazard Analysis. PHA refers to any technique that is used to identify hazards that may exist in any industrial, manufacturing or any such similar activity. More specifically it refers to the hazards that are to be identified in the process industry. As you know the "process industry" is a generic term that covers a wide range of industries such as chemicals, oil and gas, power generation, mining and the like. These industries have several hazards present due to the nature of their operations and they need to be identified, reduced to a safe enough level to minimize the risk of accidents and thus mitigate them. PHA thus refers to any technique that can reliably do so. There are several PHA techniques that are used in the process industry and they are HAZOP (Hazard and Operability Study), What-if analysis, HAZID, LOPA (Layer of Protection analysis) to name a few. Out of these HAZOP and LOPA are growing in popularity worldwide.LOPA as a PHA technique is also used as a SIL determination technique. SIL is an acronym for Safety Integrity Level and we will cover that in a separate post.

HAZOP-Hazard and Operability Study

Sep 19, 2013- HAZOP is an acronym for the popular Hazard and Operability Study. However the focus of most HAZOP studies seems to be more on the "Hazard" part rather than the "Operability" part. Did you notice it? The operability refers to how easy or how difficult would it be to operate the plant in its current form. For example, it is easy to say (and record) that in case of an upset the plant operator will close the Hand Valve HV101. However where is it located? Is it easy to close it? Is it accessible? What if it requires an effort just to reach it? Would the handle get jammed? These operability questions are very relevant in HAZOP studies and must be addressed. In recent years, almost nothing is discussed in HAZOP studies about the plant's operability. On hopes that in the coming years the operability factors will also play an important role. After all, a plant that is easy to operate and run should cause less stress amongst operating staff and thereby cause lesser dangerous incidents or accidents, is it not? One good move in recent years has been though that "human factors" are seen to be as important as the plant design factors and these would be given weightage in the new HAZOP studies. For an in-depth course on the Hazard and Operability technique, you can refer to the Abhisam training course on HAZOP.