Monitoring of occupational exposure to 1-butanol by diffusive sampling and urinalysis

To investigate the possibility of applying diffusive air sampling and urinalysis (for mother compound and metabolites) to the monitoring of exposure of factory workers to 1-butanol.

The performance of carbon cloth in adsorbing 1-butanol vapor in air was studied 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 extracted with carbon disulfide and this was followed by gas-chromatographic (GC) analysis. Urine samples were collected from factory workers occupationally exposed to 1-butanol and from rats exposed experimentally to 1-butanol vapour (up to 200 ppm). The urine samples were analyzed by GC without any pretreatment, or after treatment with hydrochloric acid or hydrolase preparation.

The performance of the carbon cloth was such that it adsorbed 1-butanol in proportion to the concentration (up to 400 ppm) and the duration (up to 10 h) of exposure, and responded quantitatively to a 15-min exposure up to 400 ppm. The amount of 1-butanol (after enzymic or acid hydrolysis) in post-exposure urine samples from rats was proportional to the exposure intensity. The proportion of free 1-butanol in total 1-butanol (i.e., free+conjugated) in urine was higher after 100 or 200 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 samples of workers exposed to 1-butanol at concentrations up to 3 ppm.

Diffusive sampling with carbon cloth as an adsorbent can be applied to ambient air monitoring of exposure to 1-butanol. Urinalysis for 1-butanol after hydrolysis is sensitive enough to detect occupational 1-butanol vapour exposure at 3 ppm.