Hippuric acid (C9H9NO3C sub 9 H sub 9 NO sub 3C9H9NO3) is a white, crystalline carboxylic acid (CAS 495-69-2) and a major metabolyte formed by the conjugation of benzoic acid and glycine, primarily in the liver. It is a natural component of mammalian urine (higher in herbivores) and acts as a biomarker for dietary phenolic compound intake and toluene exposure.