Introduction to Occupational Health, Safety and Environment (HSE)
What the exam tests
This domain covers the three pillars: occupational health (work-related ill health from chronic exposures such as noise, dust, chemicals and ergonomic load), safety (acute injuries from unplanned events) and environment (releases to air, water and land). Level 1 questions ask you to define terms and apply them to short scenarios, not to recite statutes.
Core definitions
- Hazard: a source or situation with potential to cause harm (an unguarded rotating shaft, benzene vapour).
- Risk: the combination of the likelihood of the hazardous event and the severity of harm.
- Accident: an unplanned event that has caused injury, ill health, damage or loss.
- Incident: a broader term covering accidents and near misses.
- Near miss: an incident where no harm occurred but harm was possible.
- Unsafe act vs unsafe condition: behaviour vs the state of the workplace.
The classic Heinrich ratio (1 serious : 29 minor : 300 no-injury incidents) is used to argue that reducing near misses reduces serious injuries. The cost-iceberg argument says insured costs (medical, compensation) are only a fraction, widely quoted as 1:4 or more, of uninsured costs such as downtime, retraining, investigation and reputation damage.
Worked example
A worker crosses an oily floor, slips, grabs a rail and continues unhurt. Reasoning: the oily floor is the hazard; the slip and grab is a near miss, not an accident, because no injury, damage or loss occurred; risk equals high likelihood times moderate severity. The right response is to fix the leak, clean and mark the area and review housekeeping, which are engineering and administrative controls, rather than warn staff to be careful.
Traps
- Treating hazard and risk as synonyms; a hazard exists, a risk is estimated.
- Calling a near miss nothing happened and not reporting it.
- Citing the Heinrich numbers as a law of nature rather than a model.