Optimum recovery rates using our 6-h hexane extraction method ranged from 87% to 112%. The inter-assay and intra-assay coefficients of variability for the analysis of parent pesticides were below 11%. Limits of detection (LOD) by empirical approach ranged from 30.50 ng g1 for propoxur, diazinon and DDT to 488.00 ng g1 hair for bioallethrin. Recovery rates of the metabolites by liquid–liquid extraction of the acid digest ranged from 80% to 120% using a spiked concentration of 46.86 mg g1 . Inter-assay and intra-assay coefficients of variability for the analysis of metabolites were o11%, and the LOD ranged from 0.18 (2-IPP, 3-PBA and DDE) to 5.88 mg g1 (for MMA).