Exposure assessment of ETBE in gas station workers and gasoline tanker truck drivers

Objectives: In order to measure occupational exposure concentrations of ethyl tertiarybutyl ether (ETBE), we developed a diffusive sampling method for monitoring ETBE and performed an ETBE exposure assessment. Methods: The applicability of diffusive samplers was examined by exposing the samplers to ETBE vapor in test chambers. The personal exposure levels of workers and airborne concentrations were measured at 4 gas stations. Results: The ETBE sampling rate for the diffusive samplers (VOC-SD, Sigma-Aldrich Japan) was 25.04 ml/min (25°C). Compared with the active sampling method, the diffusive samplers could be used for short-term measurements and in environments containing a mixture of organic solvents. The geometric mean (GM) of TWA-8h ETBE was 0.08 ppm (0.02-0.28 ppm) in 28 gas station workers and 0.04 ppm (0.01-0.21 ppm) in 2 gasoline tanker truck drivers. With regard to ETBE airborne concentrations, the GM was 4.12 ppm (0.93-8.71 ppm) at the handles of hanging pumps but dropped to less than 0.01 ppm (less than 0.01-0.01 ppm) at the side of a public road. Conclusion: The diffusive sampling method can be used for the measurement of occupational ETBE exposure. The threshold limit of TLV-TWA 5 ppm recommended by the ACGIH was not exceeded in any of the workers in this study.