Ozone Alerts


What are these and how can I help?

As a public service, the Evansville Environmental Protection Agency and the Vanderburgh County Health Department Ozone Office, in cooperation with the National Weather Service and the Indiana Department of Environmental Management, issue Ozone Alerts during times that ozone levels in Southwest Indiana may reach or exceed the level set by the U.S. EPA, of 70 parts per billion (ppb) averaged over eight (8) hours.


Per the U.S. EPA, if the eight hour average for ozone exceeds 70 ppb, air quality is unhealthy for sensitive groups, such as children and active adults, and people with respiratory disease, such as asthma. These people should limit prolonged outdoor exertion during Ozone Alerts. Especially in the afternoon, people with respiratory conditions, the elderly and children, should also try to stay indoors. 


In October 2015, the U.S. EPA revised the National Ambient Air Quality Standard for ozone from an eight – hour average of 75 parts per billion (ppb) to an eight-hour average of 70 ppb. Simultaneously, the U.S. EPA revised the Air Quality Index (AQI) used for reporting daily air quality levels and air quality forecasts. The AQI is designed to help you determine how clean or polluted the air is, and focuses on the associated health effects you may experience within a few hours or days after breathing polluted air. The table below compares the new AQI to previous AQI levels for ozone:   



Air Quality Index

Previous 2008 levels

New 2016 Levels


0-59 ppb / 8 hr. avg.

0-54 ppb / 8 hr. avg.


60-75 ppb / 8 hr. avg.

55-70 ppb / 8 hr. avg.

Unhealthy for Sensitive Groups

76-95 ppb / 8 hr. avg.

71-85 ppb / 8 hr. avg.


96-115 ppb / 8 hr. avg.

86-105 ppb / 8 hr. avg.

Very Unhealthy

116-374 ppb / 8 hr. avg.

106-200 ppb / 8 hr. avg.


Remember, NO BURNING is allowed during Ozone Alerts.  Use of gas and charcoal grills is permitted, but if you can postpone outdoor grilling, please do, because even gas and charcoal grills add to air pollution.


To do your share to protect air quality and reduce pollution levels:

  • CONSERVE ENERGY -reduce use of all types of energy:  electricity,       natural gas, gasoline and diesel fuel.  Turn off lights, reduce air conditioner use, etc.
  • Limit your driving.  Avoid unneccessary vehicle idling.
  • Park and go inside instead of using drive-through windows, especially if there are long lines.
  • Postpone fueling your vehicle until after 6 pm. Don’t ‘top-off’ your tank when filling up. 
  • Consider using manually operated lawn equipment.  If you use gasoline-powered lawn and garden equipment, stop working at 10:00 am and/or postpone work until after 6:00 pm.
  • Limit the use of solvents, parts-cleaning fluids, paint thinners and chemicals.  Replace lids when finished.
  • Postpone painting or use water-based paints instead of oil-based paints.


Real-time pollution levels, forecasts, and more information can be found at:  http://www.airnow.gov

Last updated: 6/9/2016 11:20:21 AM