Varies - Oxygen has numerous uses in the following industries: *steelmaking *chemicals *pharmaceuticals *petroleum processing *glass and ceramics *pulp and paper. It is used in effluent treatment plants. For some uses, such as effluent treatment and pulp and paper bleaching, oxygen is converted to ozone (O3), an even more reactive form, for maximum oxidation of noxious compounds. Oxygen is used in many processes, including the manufacture of ethylene oxide and propylene oxide. Various compounds are created by partial oxidation of hydrocarbons, ethylene dichloride, hydrogen peroxide, nitric acid, vinyl chloride and phthalic acid. Oxygen enrichment for combustion is used with increasing frequency in open-hearth furnaces, kilns and glass smelters to enhance burning capacity and reduce energy requirements. High thermal efficiency is achieved with burners that mix fuel and oxygen, with rapid combustion occurring at approximately 2800 degrees C (5072 degrees F). New combustion systems that switch from air-fuel to oxy-fuel (with furnaces and tanks built around this technology) are resulting in finer control of heat, higher efficiencies and lower fuel consumption, and lower emissions of particulates and nitrous oxide.