Hazard Identification, Risk Assessment and Risk Management
Hazard versus risk
A hazard is the source of harm (an unguarded excavation, silica dust, a suspended load). A risk is the combination of the likelihood of harm and its severity (a worker falling 3 m onto rebar and dying). Questions frequently blur the two; be precise before you answer.
Identify hazards by task analysis, job safety analysis, walk-through inspections, checklists, incident and near-miss history, plant and chemical data sheets, and consultation with the workers who do the job. Then rate risk on a matrix, typically 5 x 5: severity x likelihood gives a score that drives action (for example 1-4 low, 5-9 medium, 10-14 high, 15-25 unacceptable).
Apply the hierarchy of control: eliminate, substitute, engineering controls, administrative controls, then PPE. PPE is the last line of defence because it protects only the individual, depends on correct use and fails silently. Reassess to record the residual risk, and set controls that are specific, measurable, assigned to a named person with a due date, and verified.
Risk assessment is not once-off. It is baseline (project level), issue-based (new task, new plant, change of method) and continuous (ongoing supervision), and must be revised after an incident, a method change or a change in crew or conditions. Generic documents copied from another site fail both the law and common sense.
Traps: 'PPE first'; 'the risk is low probability so we ignore the high consequence'; a ticked checklist with no action owner; assuming a competent person's signature equals control.
Worked example
Severity 5 (fatality) x likelihood 3 = 15, high. Controls must begin at elimination or substitution (precast instead of in-situ at height). If residual risk is still 10, work only under a permit, with supervision and a verified fall protection plan.