Three Words People Use Interchangeably
Hazard, risk and harm — and why the distinction changes what you do next.
11 min
A hazard is something with the potential to cause harm. Risk is the combination of how likely that harm is and how severe it would be. Harm is the injury, ill health, damage or loss itself.
Why it matters practically
You control hazards and you evaluate risk. Confusing the two leads to a register full of entries like "working at height — high risk" with no statement of what the hazard actually is (gravity acting on a person or object above a lower level) and therefore no clear control (a physical barrier between the person and the edge).
| Hazard | Risk | Harm |
|---|---|---|
| Stored pressure in a vessel | Likelihood × severity of uncontrolled release | Blast injury, fatality |
| Noise at 95 dB(A) | Daily exposure over years | Permanent hearing loss |
| Suspended load | Frequency of lifts × exposure below | Crush injury |
Name the hazard as a thing, not an activity. "Working at height" is an activity. "A person at an unprotected edge, four metres above concrete" is a hazard you can control.