Have you ever stepped outside after a thunderstorm rolled through and noticed that the air smelled a little fresher? Some of the responsibility can be given to the temperature drop and the rain washing the air, but as dangerous and terrifying as the lightning can be, zapping through the air it creates ozone, one of the best and safest air fresheners.
There are two simple ways to make ozone without the use of chemicals; ultra-violet light and an electrical spark discharge.
When sunshine strikes earth's atmosphere, the ultra-violet radiation converts oxygen to ozone, and in turn protects us from the harmful radiation.
Ozone kills bacteria, mold spores, and mildew. It also destroys odors, and can freshen smoke filled air under most conditions. As with most things, excessive amounts of ozone are not good; recommended guidelines call for between .01 and .05 parts per million of ozone versus air.
Excessive amounts of ozone are noticeable when a bleachy smell is in the air.
Ionization of the air can produce ozone (as an electric spark does), but ionization is more useful as an air cleaner. Electronic air cleaners give dust particles a negative charge as the air passes through the front part of the grids, then collects it on positively charged plates.
Direct ion generators flood the air with negatively charged dust particles in hopes that the dust will be attracted to the positively charged walls and furniture of a room, but excessively charged air particles are not healthy; and the dust still has to be dealt with at some time.