A Hazard and Operability (HAZOP) study is a qualitative risk assessment technique used to identify potential hazards and operational problems in a system. It involves a systematic examination of a process or operation to identify deviations from the intended design or operating conditions that could lead to undesirable consequences. Other types of qualitative risk assessments include bowtie analysis and risk matrices. [1]

To determine and evaluate the hazards of a process, several methodologies can be used, including What-If, Checklist, What-If/Checklist, Hazard and Operability Study (HAZOP), Failure Mode and Effects Analysis (FMEA), and Fault Tree Analysis. [2]

A process hazard analysis should address the hazards of the process, identification of previous incidents with catastrophic potential, engineering and administrative controls, consequences of control failures, facility siting, human factors, and a qualitative evaluation of potential safety and health effects of control failures. [3]

When performing a process hazard analysis, it is important to consider the extent of process hazards, the number of potentially affected employees, the age of the process, and the process operating history to determine the priority order for conducting the analysis. [4]

A process hazard analysis should be updated and revalidated at least every five years by a team with expertise in engineering and process operations. [5]