Object Correction of urinary data by creatinine or specific gravity is required for some bio-markers to compensate the difference of urinary excretion. The literature and special health examination data on urinary 2,5-hexanedione, trichloroacetic acid and mercury were investigated to improve the significance of biological monitoring of these chemicals by modifying correction method in domestic biological exposure index.

Method The references on 2,5-hexanedione, trichloroacetic acid and mercury in urine about the limit value of each item as well as its basis were reviewed. The biological monitoring data (283,384 cases) from Korea Occupational Safety and Health Agency on these three bio-markers from 2003 to 2013 were collected and interpreted.

Result The importance for biological monitoring of hexane and trichloroethylene increased since the revision of the regulation in 2008 and 2010. The data of 2,5-hexanedione increased 400 fold since 2009, and 6 times for trichloroacetic acid since 2011. Korean exposure limit value of urinary 2,5-hexanedione is 5 mg/creatinine and 100 mg/g creatinine for trichloroacetic acid. In the UK, EU, Germany and USA, 0.4–5 mg/L of 2,5-hexanedione was applied without creatinine correction. The biological exposure limit of urinary trichloroacetic acid (TCA) of EU, Finland, the USA and Japan is 15–50 mg/L, without creatinine correction. Korean biological exposure limit is designated as 200 μg/L for urinary mercury, which is not corrected by creatinine. The biological exposure limit of urinary mercury in urine were 20–50 μg/g creatinine in most countries with creatine correction.

Conclusion For effective assessment of n-hexane, trichloroethylene, mercury, practical criteria for biological monitoring of their bio-marker should be set up to correct the analytical data by appropriate correction method.