AQI rating | Class 1 | Class 2 | Class 3 | Class 4 | Class 5 | Class 6 |
AQI standard | 0~50 | 51~100 | 101~150 | 151~200 | 201~300 | > 300 |
Evaluation | Excellent | Good | Mild pollution | Moderate pollution | Heavy pollution | Severe pollution |
Color | Green | Yellow | Orange | Red | Purple | Brown |