Technological hazard analysis: HAZOP

The HAZOP (HAZard and OPerability) review is a method which is now central to safety analyses in process industries such as the chemical or petroleum industry. It is particularly suited to the examination of systems for which control over operating conditions (settings such as flow rate, pressure, temperature, level, concentration, etc.) is particularly important for the safety of the installation.

The crux of the method is a systematic analysis of the possibility of deviations or discrepancies in the process settings, and the consequences thereof. Potential deviations are generated by the conjunction of key words which characterise a situation that differs from normal operation (such as “more”, “less”, etc.) and the operating parameters of the process.

By its very nature, this method requires a support that transposes the workings of the process. This support is the Piping and Instrumentation Diagram (P&ID or PID).

HAZOP reviews are conducted by working party led by a chairperson. It is made up of specialists capable of identifying the causes and consequences of deviations, and assessing whether the means of prevention/protection are adequate.