Biological Monitoring and Assessment of Occupational Exposure to n-hexane: A study in Shoe Making Workshops

Abstract

Background and Aims: n-hexane is widely used in the production of glues, lacquers, paints, plastic, and rubber products. Therefore, a significant potential for exposure to this toxic solvent exists in industrial settings. This study was carried out to assess the exposure to n-hexane and to determine the correlation between this exposure and urinary concentration of free 2,5-hexanedione (2,5-HD). Methods: Thirty-eight male workers from 7 shoe making workshops were studied. Individual exposure of workers to n-hexane and urinary concentration of 2,5-HD among them were determined. Data were analyzed using the SPSS/PC statistical package version 16.0. Results: The calculated time-weighted average (TWA) of exposure to n-hexane and the average urinary concentration of free 2,5-HD were estimated to be 78.6 mg/m3 and 0.23 mg/l, respectively. A significant correlation (r = 0.815) was found between time-weighted average of exposures to n-hexane and urinary levels of free 2,5-HD. Significantly higher urinary concentrations of 2,5-HD detected in subjects who did not wear gloves. Conclusions: Workers’ average exposure to n-hexane and the levels of 2,5-HD in their urine did not exceed the current recommended TLV-TWA and BEI for this chemical. Additionally, they provide further evidence in favor of the notion that free 2,5-HD is an appropriate indicator for biological monitoring of workers exposed to n-hexane. Finally, it is implied that dermal exposure also plays an important role in the overall absorption of n-hexane by the human body

Keywords

• shoe making
• n-hexane
• personal air monitoring
• biological monitoring
• 2
• 5-hexanedione