Hazard and Risk Control (International Diploma)
What the exam tests
This domain tests whether you can identify hazards, evaluate risk and select controls that are technically credible and proportionate. Expect noise, vibration, hazardous substances, confined spaces, work at height, machinery, electricity, fire and ergonomics.
Core rules
- Risk assessment: hazard, persons at risk, likelihood and severity, existing controls, residual risk, further action, review. A 5×5 matrix is common but must be justified.
- Hierarchy of control (ISO 45001 8.1.2): elimination, substitution, engineering controls, administrative controls, PPE. Collective controls before individual PPE.
- ALARP: reduce risk as low as reasonably practicable; accept residual risk only when further reduction is grossly disproportionate in cost, time or effort.
- Noise: action values commonly 80 dB(A) lower and 85 dB(A) upper; reduce at source, then isolate, then hearing protection and zones.
- Hazardous substances: assess exposure routes, compare with occupational exposure limits, use enclosure or LEV, monitor, provide health surveillance.
- Permits to work: authorization, isolation, gas testing, supervision, handover and cancellation for high-risk tasks.
Worked example
A paint shop uses solvent-based paint and workers report headaches. Reasoning: do not start with RPE. Substitute water-based paint (elimination/substitution); if not feasible, enclose the process and use LEV; then administrative controls and RPE as last resort. Verify LEV with thorough examination, monitor exposure, and provide health surveillance. This follows the hierarchy and addresses the source.
Traps
Jumping to PPE; confusing hazard with risk; ignoring residual risk and control maintenance; treating training as an engineering control; forgetting vulnerable workers; not reviewing after change.