Fundamentals and Concepts of Occupational Health, Safety and Environment
Hazard or risk?
A hazard is a source of potential harm - a wet floor, an unguarded shaft, hydrogen sulphide in a pit. Risk is the measure: how likely is harm, and how bad would it be? Candidates lose marks by calling a hazard "high risk" or describing risk as "a hazard".
The vocabulary
- Incident: any unplanned event, including near misses and accidents.
- Accident: an incident that actually caused injury, ill health or damage.
- Near miss: an incident with the potential to harm that did not.
- Unsafe act / unsafe condition: immediate causes at the sharp end; behind them sit root (system) causes.
- Occupational health deals with chronic, delayed harm (dust, noise); safety with acute injury events; environment with releases to air, water and soil.
Why it matters
Direct costs (treatment, damage) are only the tip; indirect costs - downtime, investigation, morale, legal fees, reputation - commonly run several times higher (the "iceberg"). Heinrich's 1:29:300 and Bird's 1:10:30:600 pyramids illustrate that many minor events precede a serious one. Treat them as illustrative models, not laws: the point being tested is that near misses are warning signals.
Controls and culture
Controls follow a hierarchy: eliminate, substitute, engineer, administrate, then PPE. ALARP means reducing risk as far as is reasonably practicable, leaving a residual risk. Safety culture matures from pathological → reactive → calculative → proactive → generative.
Rule of thumb
Risk = likelihood × severity, e.g. 3 × 4 = 12. Always state the scale you used, then show the score after controls.