Objectives: For several organic solvents (solvents in short), biological occupational exposure limits (BOELs) have been established for un-metabolized solvents in urine, based on the solvent exposure-urinary excretion relationship. This study was initiated to investigate the possibiliy of estimating a BOEL from the P_ow (the partition coefficient between n-octyl alcohol and water), a physico-chemical parameter. Methods: Data were available in the literatures for exposure-excretion relationship with regard to 10 solvents for men and 7 solvents for women. Results: Statistical analysis revealed that the slopes (after correction for molecular weights and logarithmic conversion) of the exposure-excretion regression lines linearly correlated ( p <0.01) with the log P_ow values the respective solvents. No significant difference ( p >0.05) was observed between men and women, and it was acceptable to combine the data for the two sexes. Thus the log P_ow-log slope relation was represented by a single equation for both sexes. Based on the observations, procedures were established to estimate BOEL values from P_ow. Successful estimations of BOELs for styrene, tetrahydrofuran and m-xylene (a representative of xylene isomers) were calculated as examples. Conclusions: The present study proposed promising procedures for estimation of a BOEL from the P_ow.(J Occup Health 2015; 57: 359–364)