Hazard Analysis
What the exam tests
Hazard analysis questions ask you to select a method that fits the system, apply it consistently, and rank risk before choosing controls. Know the difference between a hazard (source of harm) and risk (likelihood × severity).
Core methods
- JHA/JSA: task-based; list steps, hazards, controls, residual risk. Best for routine maintenance and changing tasks.
- HAZOP: process nodes and guide words (no, more, less, reverse, as well as, part of, other than). Best for chemical/process deviations.
- FMEA: component failure modes, effects, detection; RPN = severity × occurrence × detection.
- FTA: deductive, top-down from a defined top event; uses AND/OR gates.
- ETA: inductive, forward from an initiating event.
- What-if/checklist: screening or verification against a standard.
Worked example
A crew clears jams on a conveyor. A JHA lists steps: stop conveyor, open guard, reach in, clear material, restart. The hazard is unexpected startup and stored energy. Initial risk is high. Controls: LOTO with lockout verification, block against gravity, guard interlock, training, audit. PPE is last, not first. Residual risk is re-scored; if not acceptable, the task design changes.
Traps
Calling PPE a primary control; confusing hazard with risk; using FMEA for human error without a human-reliability method; failing to analyze normal start-up, shutdown, and maintenance; and not verifying residual risk.