MONITORING OF OCCUPATIONAL EXPOSURE TO DICHLOROMETHANE BY DIFFUSIVE VAPOR SAMPLING AND URINALYSIS

Objective: The aim of the present study was to develop valid methods f or monitoring of occupational exposure to dichloromethane (DCM). Metho ds: Carbon cloth as an adsorbent in diffusive sampling was tested for its capacity to adsorb DCM vapor and to retain adsorbed DCM after term ination of the exposure. Urine samples collected from DCM-exposed work ers were analyzed for DCM by the head-space technique. After extractio n with carbon disulfide, DCM in the cloth was analyzed on a DB-WAX cap illary column by flame-ionization detection gas chromatography (FID-GC ) and DCM in urine was analyzed by electron-capture detection (ECD)-GC . Results: The diffusive sampling with carbon cloth as an adsorbent is applicable to 4-h monitoring of exposure to up to 100 ppm DCM vapor. DCM concentrations detected in end-of-shift urine samples correlated l inearly with time-weighted average DCM concentrations measured in the breathing-zone air of the exposed workers; essentially the same exposu re-excretion relationship was obtained by vapor monitoring for the aft ernoon 4-h period as compared with a whole day (8-h) of vapor monitori ng. There was no sex difference in the exposure-excretion relation. Co nclusions: Both personal diffusive sampling (at up to 100 ppm DCM and for up to 4 h) and biological exposure monitoring by urinalysis for DC M are applicable in occupational health as reliable measures of exposu re to this chlorinated hydrocarbon solvent.