The 98% Sulphuric Acid is a viscous clear liquid, like oil, and this explains the old name of the acid ('oil of vitriol'). Commercial sulfuric acid is sold in several different purity grades. It is used for DAP production. They intend to replace existing CS piping with stainless steel either 304L or 316L due to frequent leakage problems. 98% Sulphuric Acid is a strong acid made by oxidizing solutions of sulphur dioxide and used in large quantities as an industrial and laboratory reagent.