This is the site I found out about the Ozone issue is called the Allergy buyers club and I also found out about this Government site from them:
http://www.epa.gov/iaq/pubs/ozonegen.html
I know this site sales things but they have a lot of good information on comparing air purifiers.
This following quote came from them,
My air cleaner,
"The "air cleaner" that you describe is actually two different devices in one package. It consists of a component that generates ozone(O3) which is supposed to remove odor-producing chemicals as well as organic compounds such as formaldehyde and a variety of solvents. The ionizer part produces either positively or negatively-charged ions which become attached to dust particles and various building surfaces. The ionizing module is supposed to remove airborne dust particles from the air of your home. Such devices are widely sold and are highly controversial. Legal action has been filed by several State Attorney's General with one high profile case in trial at this moment.
There are several major issues associated with such devices. The primary one is that
O3 is a very toxic substance that poses health risks to those exposed. Should manufacturers be selling a device to consumers that may injure their health as well as other family members? The other major issue (associated with O3 generators) is that they are not effective in controlling contaminants as claimed.
Ozone is a potent respiratory irritant even at low concentrations (> 0.10 ppmv) if the exposure occurs over a period of hours. If an O3 generator/air purifier is limited to O3 production below the level that the Food and Drug Administration (FDA) requires ( 0.05 ppmv), there is no way that there would be enough O3 in your home to "remove" the chemicals that the "air cleaner" is theoretically designed to do. It is impossible from a chemistry standpoint.
So you can see, research before taking action may save you or a loved one a trip to the hospital, or maybe even worse.
God Bless
Capt AL