Ions Versus Ozone
Ionizers should not be confused with ozone generators, even though both devices operate in a similar way. Ionizers use electrostatically charged plates to produce positively or negatively charged gas ions that particulate matter sticks to (in an effect similar to static electricity). Ozone generators are optimised to attract an extra oxygen ion to an O2 molecule, using either a corona discharge tube or UV light. Even the best ionizers will produce a small amount of ozone, and ozone generators will produce gaseous ions of molecules other than ozone, because air consists of more elements than oxygen.
At high concentrations, ozone can also be toxic to air-borne bacteria, and may destroy or kill these sometimes infectious organisms. However, the needed concentrations are toxic enough to humans and animals that the FDA in the United States explicitly demands ozone therapy not be used as medical treatment, and has taken action against businesses that fail to comply with this regulation. Ozone is a highly toxic and extremely reactive gas. A higher daily average than 0.1 ppm (0.2 mg/m³) is not recommended and can damage the lungs and olfactory bulb cells directly.
Read more about this topic: Air Ioniser