Trimellitic acid (benzene-1,2,4-tricarboxylic acid) is a chemical compound with the molecular formula C<sub>6</sub>H<sub>3</sub>(áÃÂÃÂÃÂ)<sub>3</sub>. Like the other isomers of benzenetricarboxylic acid, trimellitic acid is a colorless solid. It is prepared by oxidation of 1,2,4-trimethylbenzene.