Ozone is what it is called when three oxygen atoms bind together.

Oxygen typically likes to be in a pair, or what is referred to as O₂.

However under certain circumstances when energy is applied to oxygen it can bind together three oxygen atoms and form an ozone molecule.

Natural ozone is created from the energy of a lightning strike. The energy surge causes the oxygen atoms to bind into the three atom molecule of ozone. Ozone is the fresh smell you smell outside after a lightning storm.

This natural process of generating ozone can be replicated with certain types of light or by passing air through charged glass or ceramic plates.

Organic odors are released when organic substances are exposed to oxygen and have a chemical reaction to the oxygen called oxidation.

As the organic substances oxidize they decay, but also release odors. Ozone dramatically speeds up the oxidation process by flooding the area with ozone molecules that want to be broken up. Oxygen wants to exist in its O₂ state. When oxygen is in its O₃state the third oxygen atom is unstable and it wants to leave the molecule, so the remaining two oxygen atoms can exist in a pair. When the third atom comes in contact with organic material it oxidizes that organic material so it can leave the unstable ozone molecule.

Ozone removes odors by dramatically speeding up the natural oxidation process. But ozone can be dangerous in high amounts. Ozone can cause irritation to mucus membranes in people and can kill plants as well as bleach fabrics. 

Any time ozone is used to kill odors the area should be vacated of all people plants and pets, and ozone machines should not be placed in close proximity to fabrics or carpeting.

It is good practice to lock all areas that are being ozonated and place a sign that cautions people not to enter the area because of ozone use.

When used responsibly, and after a thorough cleaning of the area ozone is one of the best methods to remove unwanted smoke, pet, and other organic odors.