Synonyms: Sulfuric acid fuming;Fuming sulfuric acid;HSDB 1236;Oleum iodisum;Sulfur trioxide, mixt. with sulfuric acid;Sulfuric acid mixture with sulfur trioxide;Sulfuric acid, mixt with sulfur trioxide;Sulfuric acid, fuming;Sulfuric acid, mixt. with sulfur trioxide;Oleum (Fuming Sulfuric acid);Oleum 65% by weight or more free sulfur trioxide (SO3);Sulfuric acid (fuming);Sulfuric acid, fuming > or =30% free sulfur trioxide;Sulfuric acid, fuming > or =30% free sulfur trioxide [UN1831] [Corrosive];Sulfuric acid, mixture with sulfur trioxide;UN1831;oxosulfane dioxide - sulfuric acid (1:1)