Hazard Identification, Risk Assessment and Control
Domain 3 tests whether you can separate hazard from risk, apply a consistent scoring method, and justify controls through the hierarchy rather than by preference.
Core method
- Hazard is a potential source of harm; risk is the combination of likelihood and severity of that harm.
- Define the activity, who is exposed, the route (inhalation, skin, ingestion, impact, energy) and the duration.
- Score with the organisation's matrix, commonly 5x5: risk = likelihood x severity, producing bands such as low, medium, high and unacceptable.
- Control in hierarchy order: eliminate, substitute, engineering (guards, local exhaust ventilation), administrative (procedures, rotation, training), PPE last.
- Record residual risk after controls, set a review date, and re-assess on change: new plant, new chemical, new shift pattern, an incident.
Use task-based job safety analysis for non-routine work and HAZOP or similar for process plant; group similar exposure groups when assessing health hazards.
Worked example
Welding in a workshop bay: fume, UV radiation, hot metal and noise. Before controls, likelihood of harm 4 and severity 3 gives 12, a high band. A low-fume consumable plus local exhaust ventilation plus welding screens cut likelihood to 2 and severity to 2, giving 4, a medium band. A respirator and face shield handle only the residual - PPE alone would leave the score at 9 to 12. Review the assessment when extraction is serviced or the bay layout changes.
Traps
Starting at PPE because it is cheap; scoring severity only; ignoring exposure duration and route; reading low as no action instead of monitor; copying a previous assessment instead of assessing the actual task.