Ozone is an allotropic form of oxygen, with three instead of two atoms. The word ozone comes from the greek “ozein” which means “that smells, that has odor”.Ozone is a gas of unstable nature, with a characteristic pungent smell and a deep blue sky color.

Ozone occurs in nature as a product of chemical electrolysis, electric storms, and crashing surf. Ozone is present in our atmosphere, where it forms a layer that protects us from UV light radiation.

Ozone has a bad reputation as an environmental pollutant, since it is also produced as a result of the interaction of industrial waste gases containing nitrogen and sulphur, in a reaction catalized by solar light. In most cities of the world, ozone concentration is used as an indicator of environmental pollution, because it is easier to measure than the concentrations of other compounds like nitrates, sulphates or benzopirenes present in smog. In fact, the presence of ozone in evironmental pollution gases protects us: ozone is such a reactive element that it is capable of inactivating most of the industrial waste or combustion gases.