Due to the complexity of aerosol formation and the combustion process, fire and explosion hazards of flammable aerosols formed in the process industry are not fully understood. In this study, the flame propagation process of aerosolized industrial heat transfer fluids was investigated to understand the combustion phenomena in aerosol systems. Experimental observation shows different characteristics of flames propagation in aerosol systems, which are determined by the evaporated fuel vapor in aerosol system prior to encountering the flame and the amount of fuel vapor from droplets evaporating inside flames. Numerical modeling revealed that these factors were mainly determined by aerosol droplet size and velocity. The observed characteristics of the aerosol flames and the nature of continuous fuel evaporation that causes the reduction of droplet sizes suggest that ignition of flammable aerosols in the process plant might create more severe consequences than ignition of vapor mixtures. Results also imply that the aerosol dispersion conditions, as well as its formation conditions in scenarios of industrial fluid release, which determine the droplet size and movement velocity, need to be considered in assessment of fire hazard from the flammable aerosols.