The following is extracted from 40CFR Part 58 Air Quality Index Reporting; Final Rule (Federal Register/Vol. 64, No.149 August 4, 1999)
The AQI is a tool that simplifies reporting air quality to the general public. The AQI incorporates into a single index concentrations of 5 criteria pollutants: ozone (O3), particulate matter (PM), carbon monoxide (CO), sulfur dioxide (SO2), and nitrogen dioxide (NO2). The scale of the index is divided into general categories that are associated with health messages.
|
AQI |
Descriptor |
|
0 to 50 |
Good |
|
51 to 100. |
Moderate |
|
101 to 150 |
Unhealthy for Sensitive Groups |
|
151 to 200 |
Unhealthy |
|
201 to 300 |
Very Unhealthy |
|
301 and above |
Hazardous |