Comparison of BTEX Exposure between Operative and Inoperative Vapor Recovery System during Loading Fuel into the Storage Tanks at Gasoline Stations

Abstract

BTEX (Benzene, Toluene, Ethylbenzene, and Xylene) are volatile organic compounds (VOCs) that release from vaporized fuel. This study aimed to compare BTEX exposure between operative and inoperative vapor recovery system (VRS) during fuel loading into the storage tanks. BTEX concentration was measured by an active air sampler set for area monitoring from seven gasoline stations while loading fuel into the fuel tank and the sample was analyzed by gas chromatography (GC)-FID. Health risk assessment from the inhalation scenario model on exposure to BTEX was calculated for Hazard Index (HI). The findings showed that benzene concentrations from three stations (42.9%) were exceeded the NIOSH-TWA standard in inoperative VRS cases. The average of the VRS efficiency was between 60.9%-76.5% for reducing the BTEX vapor with the average concentration from 114.4 to 16.7, 332.1 to 55.3, 35.2 to 8.2, and 120.3 to 21.7 ppb for benzene, toluene, ethylbenzene, and xylene, respectively. Comparing the VRS efficiency by hazard index and risk assessment (HI), it was found that operative VRS could reduce the operator's health risk by 100 percent, resulting in HI to be less than 1 (HI min-max= 0.05-0.70) of all stations. Therefore, the findings from this study suggest entrepreneurs be aware of the usefulness of operative VRS and should strictly implement the operative VRS in fuel truck while loading as well as promote the installation of VRS at the fuel dispenser to control the BTEX vapor in working environments and prevent the health effect of workers.