Risk assessment of workers’ exposure to BTEX and hazardous area classification at gasoline stations

Abstract

Vaporization of benzene, toluene, ethylbenzene, and xylene (BTEX) compounds pollutes the air and causes health hazards at gasoline stations. This study revealed the risk of BTEX exposure according to the hazardous area classification at gasoline stations. The risk assessment of gasoline workers from a representative group of 47 stations, which followed the United States Environmental Protection Agency-IRIS method of assessing BTEX exposure, was expressed as the hazard index (HI). A result of matrix multipliers of the hazardous exposure index and fire possibility from flammable gas classified hazardous area-I and area-II at the fuel dispensers. BTEX concentrations were actively sampled in ambient air and a flammable gas detector was used to measure the flammability level. Results showed that the BTEX concentrations from ambient air monitoring were in the range of 0.1–136.9, 8.1–406.0, 0.8–24.1 and 0.4–105.5 ppb for benzene, toluene, ethylbenzene, and xylene, respectively, which exceeded the NIOSH exposure limit of 100 ppb of benzene concentration. The risk assessment indicated that five stations reached an unacceptable risk of worker exposure to BTEX (HI>1), which correlated with the numbers of gasoline dispensers and daily gasoline sold. The risk matrix classified hazardous area-I at 4 meters and hazardous area-II at 4–8 meters in radius around the fuel dispensers. This study revealed the hazardous areas at gasoline stations and suggests that entrepreneurs must strictly control the safety operation practice of workers, install vapor recovery systems on dispenser nozzles to control BTEX vaporization and keep the hazardous areas clear of fire ignition sources within an eight-meter radius of the dispensers.

Factors Affecting Adverse Health Effects of Gasoline Station Workers

“…The rural workers have limited working hours (8–12 h/day), they often do not work in shifts, resulting in longer exposure to benzene, and increasing the risk of benzene exposure. Other concerns of the health risks of gasoline workers and fire risk suggest serious control by using preventive and safety actions to eliminate sources of BTEX release in the hazardous area around the fuel dispenser, such as VRS (vapor recovery system) installation on nozzles [ 31 ].…”

“…It was common for the participants to take a short mealtime break by the fuelling station, especially during the busy hours. Therefore, employers should control the potentially hazardous area, including prohibiting workers from eating within 8 metres of the fuel dispenser zone [ 31 ], following the current labour regulation for a hygienic dining area. This study was limited by the lack of confirmation of health adverse effects for high- and a very-high level (level 4–5) of symptoms, which should be diagnosed by the physician or confirmed laboratory testing.…”

Exposure to benzene, toluene, ethylbenzene, and xylene (BTEX) at Nigeria's petrol stations: a review of current status, challenges and future directions

“…Most lead is emitted from motor vehicles as inorganic particles ( 200 ), and leaded gasoline causes more exposure to lead than any other known source ( 201 ). Furthermore, lead and BTEX in gasoline cause overlapping health hazards, including gastrointestinal and hematological disturbances, hepatic and renal damage, hypertension and neurological disorders ( 21 , 200 , 202 ). The acute and chronic health symptoms of lead and BTEX are indistinguishable from each other, and attribution would have to be done by specific measurements of lead and BTEX among occupationally exposed workers.…”

“…Although it was officially announced that lead had been phased out in Nigeria in 2004, the 2017 standard for Nigeria's gasoline still contains lead of 50 ppm and BTEX of 2% v/v (see text footnote 2). Most lead is emitted from motor vehicles as inorganic particles (200), and leaded gasoline causes more exposure to lead than any other known source (201). Furthermore, lead and BTEX in gasoline cause overlapping health hazards, including gastrointestinal and hematological disturbances, hepatic and renal damage, hypertension and neurological disorders (21,200,202).…”

Occupational fatigue and health of gas station workers: A review

“…Automobiles are thought to be the primary source of benzene because they are associated with gasoline fumes, gas stations, and gas emissions. Benzene is a colourless, volatile, soluble, flammable liquid with a high carcinogenic potential that poses a considerable danger to human health even at small doses [18]. Benzene is associated with gasoline and vehicle exhaust emissions, which permeate gas stations, and workers are inevitably exposed to them in the course of their work [19].…”