Sulfuric acid is used as an electrolyte in lead-acid batteries, and a cleaning agent. It is used in mineral processing, fertilizer manufacturing, oil refining, wastewater processing, and chemical synthesis. It is also used in the production of detergents, synthetic resins, dyestuffs, pharmaceuticals, petroleum catalysts, insecticides, antifreeze, processes such as oil well acidizing, aluminum reduction, paper sizing, pigments, enamels, printing inks, coated fabrics and paper. It is also used in the production of explosives, cellophane, acetate and viscose textiles, lubricants, non-ferrous metals and batteries. Sulfuric acid immobilized on silica gel is used as an efficient and benign catalyst.