Ozone is tri-atomic oxygen, it exists in nature within the stratosphere (from a height of 10 kms to 50 kms), small amounts of ozone is constantly being produced by the action of sun's UV radiation that splits oxygen (O2) to from single oxygen atoms. These atoms combine with the remaining oxygen molecules to form Ozone (O3) molecules, which are very effective at absorbing suns UV rays.
Ozone is also formed from the pollution from burning fossil fuel which creates smoke and carbon monoxide, and lighting creates nitrogen oxides. All of these chemicals, combined together with unstable compounds and in the presence of sunlight, form ozone as a by-product. At ground level, ozone at atmospheric conditions is very unstable, due to this unstable nature; it reduces to oxygen within a very short span of 60 min. in air and 20 mins. in water. This reduction reaction releases one atom of oxygen with act as a very powerful oxidizing agent as a very powerful disinfectant, on the principle of oxidation the garments are treated and the color, look appears on the treated garments.
Even today, many manufacturers feel that by using Ozone Gas their denim garments they would simply bleach them to lighter blue only. This is true since the Indian denim manufacturers and users are used to the brighter colour of Indigo achieved with the help of optical brighteners that sometimes it is difficult for them to accept the duller colours achieved through Ozone processing.
Though it changes the colour of the Indigo dye, Ozone eliminates tinting from the reverse of the denims as also from the sewing thread, pocket fabric, labels, zippers, buttons etc. giving the garment a cleaner look. Ozone also destroys all air borne micro-organisms including bacteria, virus, mold, fungi, spores, etc. It also oxidizes the volatile organic chemicals, including aromatic chemicals reducing them into lower molecular organics which are no more aromatic in nature; hence the hand-feel in garments is enhanced after the treatment. Furthermore, the discharge of the Ozone purifies the atmosphere by adding freshness and giving clear, pollution free-oxygen rich air.
Since ozone has the bleaching property, low ozone dosage helps in avoiding bleaching action, while enabling the washed clothes come out brighter it also sanitized them at the same time. Ozone's sanitizing property makes it very relevant to the hospitals as also the hotels. The use of ozone reduces the requirement of detergents and also the wash can be achieved at lower temperatures. Thus, a specially designed Ozone system helps in reducing the use of water as well as energy cost for heating, resulting in large savings. Besides this, the added advantage is that the waste water from the laundry has much lower detergent contents which requires very little or no waste water treatment prior to letting it out in to the sewage system.