| Hazard index | Hazard index class | Hazard level | Color |
| 0 - 24 | 1 | No or very low | Blue |
| >24 - 48 | 2 | Low | Green |
| >48 - 72 | 3 | Moderate | Yellow |
| >72 - 96 | 4 | High | Orange |
| >96 - 120 | 5 | Very high | Red |