Ozone is oxygen but in a different form. It contains three oxygen molecules and not two. The third molecule can detach and apply itself to other chemicals or substances. This ability to attach to other substances means the ozone is able to alter these substances. This is why ozone is generated and used for certain purposes.

Ozone is found in layers of the earth's atmosphere where it filters out harmful ultra-violet rays. When ozone is found at the ground level, it is harmful to the respiratory system. Used as an industrial gas, ozone cannot be created and then transported because it decays quickly. Instead, it must be created on site. Because it oxidizes metal, the choices for its containment are limited. Titanium, stainless steel, glass, aluminum and polymers polytetrafluorethylene and polyvinylidene fluoride are used to contain ozone.

Ozone can be generated in two ways--silent corona discharge and ultra-violet radiation. The ultra-violet generation is like the process of ozone creation in the upper atmosphere and the corona discharge is similar to the way ozone is generated in lightning. Ultra-violet generation involves the use of mercury and creates issues around proper disposal. The silent corona method produces more ozone than the other method and is a much more efficient process.

The silent corona discharge method consists of a unit with these parts--dust filters, gas dryers, a source of oxygen, a generator, a contact unit and torch destructor. Dryers and filters clean the oxygen. The ozone is generated from the cleaned oxygen by electrical discharge just like lightning. By splitting the oxygen and creating single molecules, the single molecules can attach to oxygen (O2) and create O3. The O3 is then discharged into the room.

Ozone generators are controversial. While useful in industrial (purifying water, bleaching wood pulp, detoxifying cyanide waste) and medical applications (killing bacteria, viruses, odors) where strict standards are followed for manufacturing and using the generators, the use of ozone in smaller home or personal devices could be harmful. Those used in industrial and medical settings are used in unoccupied situations.

Ozone can cause respiratory irritation so when a device is used in a confined space the device should follow Food and Drug Administration guidelines. Public health standards have been set that indicate the maximum amount of ozone that is safe for humans to interact with.

For an ozone generator to produce enough ozone to kill bacteria and viruses, it must exceed the public health standards.