NEPBIOS/ASPT | Class | Description | Color Code |
7.00 - 10.00 | I | Non to very slight pollution | Blue |
5.50 - 6.99 | II | moderate pollution | Green |
4.00 - 5.49 | III | Critical pollution | Yellow |
2.50 - 3.99 | IV | Heavy pollution | Orange |
1.00 - 2.49 | V | Very heavy to extreme pollution | Red |