What is Ozone ?
Ozone is one of the several gases that make up the earth’s atmosphere. It is the triatomic form of oxygen and makes up approximately one part in three million of all of the gases in the atmosphere. If all the ozone contained in the atmosphere from the ground level up to a height of 60 km could be assembled at the earth’s surface, it would comprise a layer of gas only about 3 millimeters thick, and weigh some 3000 million tonnes. Ozone is toxic at high concentrations because it reacts strongly with other molecules.