Air Quality Index Scale
0 - 50
Good
51 - 100
Moderate
101 - 150
Unhealthy for Sensitive Groups (USG)
151 - 200
Unhealthy
201 - 300
Very Unhealthy
301 +
Hazardous
Air Quality Index Scale
EPA will host the National Air Quality Conference (NAQC) March 18-21, 2024 at EPA’s Research Triangle Park, North Carolina, campus.
Visit the NAQC webpage to learn more about this event and how to register