| 0–50 |
Good
|
Air quality is considered satisfactory, and air pollution poses little or no risk.
|
| 51–100 |
Moderate
|
Air quality is acceptable. However, unusually sensitive people may experience moderate health concerns.
|
| 101–150 |
Unhealthy for Sensitive Groups
|
Members of sensitive groups may experience health effects. The general public is less likely to be affected.
|
| 151–200 |
Unhealthy
|
Everyone may begin to experience health effects. Sensitive groups may experience more serious effects.
|
| 201–300 |
Very Unhealthy
|
Health warnings of emergency conditions may be issued. The entire population is more likely to be affected.
|
| 301+ |
Hazardous
|
Health alert conditions exist. Everyone may experience serious health effects.
|