Risk Assessment and Control
Domain 3 tests the five-step assessment cycle, the scoring matrix, and whether your chosen controls genuinely follow the hierarchy.
The cycle
Identify hazards; decide who may be harmed and how; evaluate risk and set controls; record significant findings; review at defined triggers (change, incident, new information, periodic date).
Scoring
A 5x5 matrix multiplies likelihood by severity. A score of 20 (likely x major injury) demands action before work starts; 8 after controls may be tolerable with monitoring. Always record the residual risk after controls, not only the initial score.
Hierarchy of control
- Eliminate the task or hazard.
- Substitute a safer method or material.
- Engineering: guarding, isolation, LEV, edge protection, interlocks.
- Administrative: safe system of work, permits, rotation, signage, training.
- PPE as the last resort.
Worked example
Chasing cables with a grinder: initial likelihood 5 x severity 4 = 20. Replace chasing with surface trunking (substitution) where feasible; otherwise water suppression plus on-tool extraction, a zoned area, and fit-tested RPE. Residual 2 x 3 = 6, tolerable with monitoring and health surveillance. Reasoning: controls move up the hierarchy where practicable, and the score is recomputed rather than assumed.
Traps
Scoring only before controls; putting a hazard description in the risk column; listing controls with no owner, date or verification; generic assessments copied between sites with no site names or tasks; treating a permit as a control in itself rather than a check that controls exist.