Among the paint workers, the median methyl hippuric acid level and median hippuric acid level were 50.75 mg/g creatinine
(range, 0.3–331.7) and 423.5 mg/g creatinine (range, 5.5–2626.9), respectively. This study found a correlation between airborne xylene and urinary methyl hippuric acid levels (p < 0.001) and found a correlation between airborne toluene and urinary hippuric acid levels (p < 0.001), respectively.