Ozone machines, or generators, have been part of the air purification market for some time, but few know how the process actually works. A fairly simple chemical reaction removes odor-causing pathogens from the air. While ozone generators are found to be effective and are cleared for home use, there is some speculation as to the safety and validity of vendors' claims.
According to the Connecticut Department of Public Heath's "Fact Sheet" on ozone air purification, these generators work on the principle or oxidation. The air is full of O2 molecules, or two oxygen molecules bound together. In our atmosphere, exposure to UV energy creates unsound molecules of three bound oxygen atoms, or O3. This phenomenon can only sustain itself for about 30 minutes, when the chemical bounds that tie break down, creating an O2 and O1 molecule. The highly reactant single oxygen atoms will attach themselves to many particles in the air.
In order to bring the benefits of O3 into the home, ozone generators use electricity to create the molecules using the existent O2 in the air. Air Zone, one of the leading online vendors of ozone generators on the internet, claims on its website that when ozone proportions are correct, the units are safe and effective to remove odors. The O3 molecules break apart and leave behind the O1 molecules to attack odor-causing pathogens. This would create the only by-product of the generators: O2 already found in the air we breath.
While the U.S. Environmental Protection Agency has not publicly banned the use of ozone generators, there are concerns being raised. On the EPA website, the Indoor Air Quality report states that ozone generators have not been found to be effective in removing odor-causing pathogens from the air. It goes on to report that in order for the chemical process to be effective, the levels of ozone would need to "far exceed public health standards." There have been findings indicating that the ozone machines may contribute to respiratory issues and simply subdue the sense of smell. More study is needed to determine the long-term effects of ozone exposure.