Hemimellitic acid (benzene-1,2,3-tricarboxylic acid) is an organic compound with the molecular formula C<sub>6</sub>H<sub>3</sub>(áÃÂ<sub>2</sub>ÃÂ)<sub>3</sub>. Like the other isomers of benzenetricarboxylic acid, hemimellitic acid is a colorless solid. It is prepared by oxidation of 1,2,3-trimethylbenzene.