California air board issues warning 
on ozone emitting air purifiers

SACRAMENTO, CA (01/24/05) -- The California Air Resources Board (ARB) has announced it has heard evidence revealing the unrecognized danger from indoor air purifiers known as ozone generators. 

"These machines are insidious," said acting ARB Chairperson Barbara Riordan. "Marketed as a strong defense against indoor air pollution, they emit ozone, the same chemical that the ARB and the USEPA (U.S. Environmental Protection Agency) have been trying to eliminate from our air for decades. More chilling is that some people susceptible to the ill effects of ozone will eagerly bring these Trojan horses home."

Recently, ARB staff reported the results from multiple studies of ozone generating machines to Board members. One study, conducted by the USEPA, ran an ozone generator in a test home at its maximum setting. When the room's air was sampled, ozone levels were found exceeding 0.3 parts per million (ppm), and an adjacent room's levels exceeded 0.2 ppm. This level is equal to a stage one smog alert when local air pollution control districts advise the public to avoid some outdoor activities. These readings far exceed the state's ambient one-hour standard for ozone of 0.09 ppm, and any recently observed outdoor peak levels in California. At the machine's medium setting, even with the home's central fan turned on, ozone levels still exceeded the state standard. 

The Board said these findings have forced it to  recommend that the public avoid using these devices.

The ARB and a handful of other state and federal agencies have taken actions in an attempt to address this health issue. However, according to the ARB, no agency has clear authority to control ozone emissions from devices, and actions to date have not been effective in addressing this problem. 

More information on air purifiers is available on the ARB website. The ARB staff presentation to the board is available online.