HAZOP meaning

A HAZOP (Hazard and Operability study) is a structured, team-based review used in legal practice to evidence process safety and health and safety compliance for the design, modification and operation of process plant. The study systematically challenges the intended design by applying standard “guidewords” to identify credible deviations, major accident hazards and operability problems, and to document existing safeguards and required actions. HAZOP is not defined in legislation or case law; it is a descriptive engineering method widely recognised in UK regulator guidance and by international standards (for example IEC 61882). In practice, it is commonly referenced in contracts and tender specifications, and relied on by regulators and experts in COMAH/Seveso safety reports, safety cases, management of change and pre‑start‑up reviews. Its legal significance lies in demonstrating that hazards have been identified and risks reduced so far as is reasonably practicable (ALARP/SFARP), supporting due diligence, board assurance and regulatory inspections and investigations. Usage and expectations are broadly consistent across England & Wales, Scotland and Northern Ireland under the COMAH regimes, and in Ireland under the Seveso III Regulations enforced by the Health and Safety Authority.