Recent severe accidents occurred among the vegetable oil refining industry evidenced the hazards connected with extracted edible oils due to high residual solvent content (RSC), typically hexane, a high flammable volatile substance. The present study provides a methodology for the analysis of hazards related to the RSC in normal and maintenance operations for crude edible oil storage tanks. A thermodynamic model allowed the analysis of possible operative conditions leading to the formation of flammable mixtures inside the vessels. A specific experimental analysis was devoted to the characterization of the bottom sludge evidencing the potential formation of flammable mixtures in maintenance operations. The analysis provided a quantitative tool for the preliminary screening of the hazards connected to the storage of crude vegetable oils.
