Simulation of benzene exposure during use of a mineral spirit solvent to clean elevator bearing housings

An exposure simulation was conducted to reconstruct and assess a sheet-metal worker's historical exposure to benzene associated with the degreasing and cleaning of parts and equipment during the repair of a soybean elevator head pulley. The simulation was based on an employee description of the specific activities performed in the 1980s. Bulk solvent and airborne benzene concentrations associated with the degreasing and cleaning of parts and equipment using a bucket of mineral spirits solvent and soaked shop towels were measured during the simulation. The mineral solvent was spiked with benzene to represent the historical product formulation. Benzene concentrations in personal and background air samples were below the limits of analytical detection. These data were used to estimate a worker's inhalation and dermal exposure to benzene from the cleaning and degreasing task. The total dose of approximately 0.2 mg benzene estimated based on the simulation results is approximately equivalent to that received from non-occupational sources by individuals living in urban areas. This study demonstrated the utility of an exposure simulation in reconstructing and assessing historical worker exposures in a situation where no useful exposure data were available to characterize the exposure of interest.