What is a HAZOP study?

A HAZOP (Hazard and Operability) study is a team-based review method that examines a process, piece of equipment, or system section by section, asking what would happen if a parameter (flow, pressure, temperature, etc.) deviated from its intended design value. The goal is to identify hazards and operability issues before they cause an incident.

How a HAZOP study works

  1. Divide the process into nodes — discrete sections of a piping and instrumentation diagram (P&ID) or procedure
  2. Apply guide words — terms like "no," "more," "less," "reverse," and "other than" are combined with process parameters to systematically generate deviations (e.g., "more flow," "no pressure")
  3. Assess each deviation — the team identifies causes, consequences, existing safeguards, and any additional actions needed
  4. Record and track actions — findings are logged and assigned owners for follow-up

Where HAZOP is used

HAZOP studies are most common in industries with significant process safety risk: chemical plants, oil and gas facilities, refineries, and pharmaceutical manufacturing. They're typically a required part of process safety management (PSM) programs.

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