PM2.5 USA Standard
Good: PM2.5 < 12 ug/m³
Moderate: 12 ≤ PM2.5 < 35.5 ug/m³
Unhealthy for Sensitive Groups: 35.5 ≤ PM2.5 < 55.5 ug/m³
Unhealthy: 55.5 ≤ PM2.5 < 150.5 ug/m³
Very Unhealthy: 150.5 ≤ PM2.5 < 250.5 ug/m³
Hazardous: PM2.5 ≥ 250.5 ug/m³
AQI Meaning
Good-Air quality is considered satisfactory, and air pollution poses little or no risk.
Moderate-Air quality is acceptable; however, for some pollutants there may be a moderate health concern for a very small number of people who are unusually sensitive to air pollution.
Unhealthy for Sensitive Groups-Members of sensitive groups may experience health effects. The general public is not likely to be affected.
Unhealthy-Everyone may begin to experience health effects; members of sensitive groups may experience more serious health effects.
Very Unhealthy-Health alert: everyone may experience more serious health effects.
Hazardous-Health warnings of emergency conditions. The entire population is more likely to be affected.