Ozone (O3 ) is a highly reactive and unstable gas composed of three oxygen atoms. It is both a natural and a man-made product that occurs in the Earth's upper atmosphere (the stratosphere) and lower atmosphere (the troposphere).

Technologically, ozone is obtained by emptying electrons in the gas medium between two electrodes separated from each other by means of the dielectricum. Between the electrodes, at least 50 Hz. alternating current at frequency is applied.

The strong electrophilic structure of ozone allows ozone to react with many groups of organic and organometallic functions. Most ozone reactions are based on the breakdown of the carbon-carbon double bond.

The Inorganic chemistry of ozone is similar to other members of the periodic system. Ozone has an oxidation potential of 2.09 V. Ozone does not react with metal ions such as calcium and sodium. In addition, it reacts with all elements of the halide series except fluorine. The reason it does not react with fluorine is that fluorine is the only element whose oxidation potential is higher than ozone.

Alkali metal ions do not react with ozone. Because they have only one oxidation state. Transition elements are oxidized to the highest oxidation levels by ozone. The ability of metals in this state to melt in water is less than they are at a low oxidation level. This property of ozone is often used in industry to reduce iron and manganese in water to the lowest levels.

The reaction of ozone with various organic nitrogen compounds is generally very complex. Many essential amino acids contained in proteins are oxidized by ozone in their aqueous solutions at room temperature. (Table 1)

Although the odor threshold of ozone varies according to individuals, the amount of 100 microgram/m³ in the air is felt by many people. This ratio, when 400 microgram/m³ could be felt by everyone, but it does not bother people.

Ozonun etkilerinden sözederken kullanılan “artık ozon”, suya ilave edilen ozon miktarından, suyun tükettiği ozon miktarı çıkarıldığında bulunan miktardır. Suyun tükettiği ozon miktarı, suda ozon ile reaksiyona girecek maddelerin varlığına bağlı olarak değişmektedir. Bu hesaplamalar yapılırken, ozon gazının suda çözünürlüğü ve suda çözülemeyen ozonun bir kısmının dışarı atıldığı dikkate alınmalıdır. (Tablo 2)