Hazard identification, risk assessment and control hierarchy
This domain tests HIRARC: Hazard Identification, Risk Assessment and Risk Control. The exam expects you to spot hazards, judge risk and choose controls in the right order, not jump straight to PPE.
Core rules
- Identify hazards from the task, plant, substances, environment and people. Consider routine and non-routine work, maintenance, cleaning and emergencies.
- Assess risk as likelihood multiplied by severity. Record who is exposed and what could happen.
- Apply the hierarchy: elimination, substitution, engineering controls, administrative controls, then PPE. PPE is last because it protects only the wearer and depends on correct use.
- Record residual risk, set review dates and reassess after changes, incidents or new information.
Worked example
Cutting concrete blocks with a petrol cut-off saw creates dust, noise, vibration and flying fragments. Elimination is not practical, so substitute by using a block splitter if suitable. Engineering controls include wet cutting or on-tool extraction and a barrier. Administrative controls include rotation and exclusion of others. PPE includes hearing protection, eye protection and suitable respiratory protection. The reasoning is that dust and noise are reduced at source before relying on the worker's PPE.
Traps
Do not put PPE first. Do not treat the risk assessment as paperwork to file and forget. Do not ignore changing conditions such as wind, rain, night work or a new crew.