MONITORING OF OCCUPATIONAL EXPOSURE TO 1-BUTANOL BY DIFFUSIVE SAMPLING AND URINALYSIS

Objectives: To investigate the possibility of applying diffusive air s ampling and urinalysis (for mother compound and metabolites) to the mo nitoring of exposure of factory workers to 1-butanol. Methods: The per formance of carbon cloth in adsorbing 1-butanol vapor in air was studi ed by experimental exposure of the cloth to 1-butanol at 50, 100, 200 or 400 ppm for up to 10 h. 1-Butanol in the exposed cloth was extracte d with carbon disulfide and this was followed by gas-chromatographic ( GC) analysis. Urine samples were collected from factory workers occupa tionally exposed to 1-butanol and from rats exposed experimentally to 1-butanol vapour (up to 200 ppm). The urine samples were analyzed by G C without any pretreatment, or after treatment with hydrochloric acid or hydrolase preparation. Results: The performance of the carbon cloth was such that it adsorbed 1-butanol in proportion to the concentratio n (up to 400 ppm) and the duration (up to 10 h) of exposure, and respo nded quantitatively to a 15-min exposure up to 400 ppm. The amount of 1-butanol (after enzymic or acid hydrolysis) in post-exposure urine sa mples from rats was proportional to the exposure intensity. The propor tion of free 1-butanol in total 1-butanol (i.e., free + conjugated) in urine was higher after 100 or 300 ppm exposure (35-40%) than after 50 ppm exposure (about 8%). There was a significant increase in total 1- butanol concentration (but not in free 1-butanol) in shift-end urine s amples of workers exposed to 1-butanol at concentrations up to 3 ppm. Conclusions: Diffusive sampling with carbon cloth as an adsorbent can be applied to ambient air monitoring of exposure to 1-butanol. Urinaly sis for 1-butanol after hydrolysis is sensitive enough to detect occup ational 1-butanol vapour exposure at 3 ppm.