Understanding the Air Quality Index

The purpose of the Air Quality Index or AQI is to help you understand what local air quality means to your health. To make it easier to understand, the AQI is divided into six categories. Each category corresponds to a different level of health concern. The six levels of health concern and what they mean are provided in the chart below. EPA has assigned a specific color to each AQI category to make it easier for people to understand quickly whether air pollution is reaching unhealthy levels in their communities. For example, the color orange means that conditions are “unhealthy for sensitive groups,” while red means that conditions may be “unhealthy for everyone,” and so on.
Air Quality Index
(AQI) Values
Levels of Health Concern
...as symbolized
by this color:
when the AQI
is in this range:
...air quality conditions are:
the health implications are:
0 to 50
Air quality is considered satisfactory, and air pollution poses little or no risk.
51 to 100
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.
101 to 150
Unhealthy for
Sensitive Groups
Members of sensitive groups may experience health effects. The general public is not likely to be affected.
151 to 200
Everyone may begin to experience health effects; members of sensitive groups may experience more serious health effects.
201 to 300
Very Unhealthy
Health alert: everyone may experience more serious health effects.
301 to 500
Health warnings of emergency conditions. The entire population is more likely to be affected.

For information on Baton Rouge’s air quality call: Ozone forecast 225-219-0857 or AQI hotline 225-219-3543.


Louisiana Department of Environmental Quality 602 N. Fifth Street Baton Rouge, LA 70802
Call or e-mail a hotline · Office Address/Phone listing · Locate a DEQ employee
Call 1-866-896-LDEQ or e-mail our Customer Service Center with questions or comments