The American Lung Association® has long recognized that ozone is a potent lung irritant that is produced directly by ozone generators. We are concerned with the direct and purposeful introduction of a lung irritant into indoor air. There is no difference, despite some marketers' claims, between outdoor ozone in smog and ozone produced by these devices.

Under certain use conditions ozone generating air cleaners, ion generators and some other electronic air cleaners can produce levels of this lung irritant significantly above levels thought harmful to human health. Additionally, none of the data we have seen would indicate that ozone generators "clean" indoor air more effectively than mechanical or other electronic devices, despite the claims of their manufacturers.

The U.S. Food and Drug Administration (FDA) does not approve air cleaners in the same way it approves a new drug. However, some air cleaners that claim a health benefit may be regulated by the FDA as a medical device (air cleaners are categorized by FDA as "Class II medical devices"). For medical devices, including air cleaners, the FDA has set a limit of 0.05 parts per million of ozone. Although ozone can be useful in reducing odors and pollutants in unoccupied spaces (such as removing smoke odors from homes involved in fires) the levels needed to achieve this are above those generally thought to be safe for humans.

Last fall the Federal Trade Commission (FTC) ordered the manufacturers of two ozone generating air cleaners to stop making marketing claims that ozone is effective in cleaning indoor air , that their products do not create harmful by-products, and that they prevent or provide relief from allergies, asthma, and other specified conditions, unless the claims are supported by reliable and adequate substantiation.

Talking Points:

There is no difference, despite some marketers' claims, between outdoor ozone in smog and ozone produced by an "air cleaning" device.

Ozone is a potent lung irritant that is produced directly by ozone generators and sometimes indirectly by ion generators and some other electronic air cleaners.

Exposure to increased outdoor levels of ozone is a contributor to lung disease and is especially dangerous for persons with asthma and other chronic lung diseases, children, and the elderly. Comparable indoor levels would be expected to produce similar effects.

The FDA has set a limit of 0.05 parts per million of ozone for medical devices.

Manufacturers of certain ozone generators are prohibited by the FTC from making marketing claims that ozone is effective in cleaning indoor air, that their products do not create harmful by-products, and that they prevent or provide relief from allergies, asthma, and other specified conditions, unless the claims are supported by reliable and adequate substantiation.

Studies by the U.S. EPA and NIOSH provide no data to suggest that ozone generators "clean" indoor air more effectively than mechanical or other electronic devices, despite the claims of their manufacturers.

Consumer Reports evaluated two ozone generators in 1992 and found them "not acceptable" due to excessive ozone production.