How to use Process Safety Analysis to the benefit of your process plant?
What is Process Hazard Analysis (PHA)? A PHA is required for any industrial process that makes use of hazardous chemicals. Its purpose is to identify the significance of scenarios (potential causes and consequences) that could result in fires, explosions, chemical spills and the release of toxic chemicals. It focuses on factors that might affect the process (equipment, instrumentation, utilities, human actions (routine and non-routine), and external factors).
Steps in the PHA Process
Methods for Conducting the PHA:
- What-if Study – for review of an uncomplicated processes;
- Checklist – for a more complicated process using a checklist;
- Hazard and Operability Study (HAZOP) – a structured method to analyze possible deviations in design conditions;
- Failure Mode and Effects Analysis (FMEA) – a systematic study of component failures that could conceivably affect the safety of the operation;
- Fault Tree Analysis – either a qualitative or a quantitative model of all the undesirable outcomes, that could result from a specific initiating event; or
- An appropriate equivalent method.
The process hazard analysis is best performed by a team with expertise in engineering and process operations. The PHA team should include:
- Employees who have experience with and knowledge of the process being evaluated; and
- Team leader who has knowledgeable in the specific PSM analysis methodology being used in the evaluation.
It is advised that, at least every five years after the completion of the initial process hazard analysis or whenever there is a change in process, the process hazard analysis must be updated and revalidated by a qualified team to ensure that the hazard analysis is consistent with the current process.