Key to Risk Assessment Ratings
| Likelihood of Occurrence (LO) | Frequency of Exposure (FE) | ||
| 0.1 | Almost impossible/Possible in extreme circumstances | 0.1 | Infrequently |
| 0.5 | Highly unlikely though conceivable | 0.2 | Annually |
| 1 | Unlikely but could occur | 1 | Monthly |
| 2 | Possible but unusual | 1.5 | Weekly |
| 5 | Even chance – could happen | 2.5 | Daily |
| 8 | Probable – not surprised | 4 | Hourly |
| 10 | Likely, only to be expected | 5 | Constantly |
| 15 | Certain, no doubt | ||
| Degree of possible harm (DPH) | Number of persons at risk (NP) | ||
| 0.1 | Scratch or bruise | 1 | 1 – 2 persons |
| 0.5 | Laceration, mild ill-health | 2 | 3 – 7 persons |
| 1 | Break minor bone or illness (temporary) | 4 | 8 – 15 persons |
| 2 | Break major bone or illness (permanent) | 8 | 16 – 50 persons |
| 4 | Loss of 1 limb or eye/serious illness (temporary) | 12 | 51 or more persons |
| 8 | Loss of 2 limbs or eyes/serious illness (permanent) | ||
| 15 | Fatality | ||
Degree of Risk Evaluation
| Risk Index | Evaluation |
|---|---|
| 0 - 1 | Negligible |
| 2 - 5 | Very Low |
| 6 - 10 | Low |
| 11 - 50 | Significant |
| 51 - 100 | High |
| 101 - 500 | Very High |
| 501 - 1000 | Extreme |
| > 1001 | Unacceptable |