Ionic air fresheners are designed to remove dust and other pollutants from the air using a stream of negatively charged particles.
These negative ions pass their charge onto pollutants in the air which are then attracted to a positively charged plate by magnetism. There is, however, some debate over whether an ionic air freshener is actually effective in cleaning the air, and some medical professionals are concerned that the machines emit ozone, which can be dangerous.
Some experts have doubted the ability of the ionic air fresheners to improve air quality, especially in models that are not equipped with fans.
Ozone is another source of concern. Although ozone is an excellent germicide, it also is dangerous to humans if concentrations get too high. Ionic air fresheners produce only low levels of ozone, but in an enclosed space, levels of ozone can rise to dangerous levels.
Ionic air fresheners are built around this premise, generating a steady stream of negative ions into the air. As ions encounter particles floating in the air, such as dust, they pass on their negative charge. After being charged, the particles are attracted to positively charged molecules, forming clusters that become too heavy to float and fall out of the atmosphere. A positively charged plate is often installed on an ionic air freshener to attract pollutants like a magnet.
Manufacturers claim that the ionic air fresheners can remove odors, dust, smoke, allergens and other irritants from the air. Some machines are equipped with a fan to circulate air and draw in pollutants, but they are otherwise silent. Advocates also point out that the ozone generated by an ionic air freshener acts as an oxidizer and germicide, making the air cleaner and safer to breathe.