HAZOP Guidewords + Node Examples 2026 — IEC 61882 Reference

Machine-readable reference of HAZOP (Hazard and Operability Study) guidewords, their meanings applied to key process parameters, and concrete process-industry deviation examples. Follows IEC 61882:2016 methodology and CCPS HAZOP guidance.

Seven standard guidewords covered:

NO / NOT — complete negation (no flow, no reaction, no level)

MORE — quantitative increase (high flow, high temperature, high pressure, high level)

LESS — quantitative decrease (low flow, low temperature, low pressure, low level)

AS WELL AS — additional component present (contamination, two-phase flow)

PART OF — partial completion (partial flow, incomplete reaction)

REVERSE — logical opposite (backflow, reverse rotation)

OTHER THAN — complete substitution (wrong material, wrong utility, wrong operating mode)

Each row provides: guideword, meaning, parameter, example deviation, example cause, example consequence, and example safeguard/protection layer — giving ~20 worked examples spanning flow, pressure, temperature, level, composition, reaction, rotation, and operating mode.

Useful for: HAZOP team facilitation, ARIA AI assistant grounding for HAZOP queries, process safety training, HAZOP team member competency development, IEC 61882 refresher material.

Sources: IEC 61882:2016 (HAZOP studies — application guide), CCPS HAZOP guidance (AIChE), Crawley and Tyler HAZOP Study: A Practitioner's Guide (2015). Published as part of the SmartQHSE Open HSE Data collection.