Likelihood scoring scale
This table explains the scoring used to determine the probability of a particular hazard occurring.
| Level |
Descriptor |
Likelihood over 5 years
(expressed as percentage) |
Likelihood over 5 years
(expressed as odds) |
| 1 |
Negligible |
> 0.005% |
> 1 in 20 000 chance |
| 2 |
Rare |
> 0.05% |
> 1 in 2 000 chance |
| 3 |
Unlikely |
> 0.5% |
> 1 in 200 chance |
| 4 |
Possible |
> 5% |
> 1 in 20 chance |
| 5 |
Probable |
> 50% |
> 1 in 2 chance |
