Ozone, a lung irritant, is produced indirectly by ion generators and some other electronic air filters and directly by ozone generators. While indirect ozone production is a cause for concern, even more so is the direct and deliberate introduction of a lung irritant into indoor air. There is no difference, despite what some marketers claim, between the ozone found in outdoor contaminated fog and the ozone produced by these devices. Under certain conditions of use, ion generators and other air filters that generate ozone can produce levels of this lung irritant much higher than levels considered harmful to human health.
The FDA can regulate a small percentage of air purifiers that claim to be beneficial to health as medical devices. The Food and Drug Administration has set a limit of 0.05 parts per million of ozone for medical devices. While ozone can be used to reduce odors and contaminants in vacant spaces (for example, eliminate the smell of smoke from homes that cause fires), the levels needed to achieve this are above those generally considered safe for humans. Ionizers better remove smaller molecules, such as bacteria and viruses, so they may not benefit people with allergies or asthma.
Ionizers also do not remove particles from circulation. Instead, they charge them to stay on something else. Unless you constantly clean the hard and soft surfaces of your home, it becomes difficult to remove particles that have fallen to the floor. Before deciding whether or not to install an air purifier with ionizer in your home, it's useful to understand what ions and ionizers are and how the ionization function of a purifier works air.
The Sunpentown SH-1508 ceramic tower heater has an ionizer and an air filter to keep the air warm and breathable, the Sunpentown SF-610 evaporative air cooler has an ionizer in its oxygen bar, and the Sunpentown microcomputer fan uses an ionic air purifier to cool you down as it cools.