To obtain an aqueous aerosol composition which shows extremely low corrosiveness to metals and permits long-term storage in metallic vessels by making the composition include a dry process silica.

This composition is made to include a dry process silica, e.g. aerosol 130 (brand name) or the like, in a proportion of 0.1-5 wt.% based on the whole weight of the objective composition. The dry process silica is silicon oxide (SiO2) and its equivalent substance usually obtained by flame process, which causes the decomposition of halogenized silicons by oxyhydrogen flame or the thermolysis of organic silicon compounds, or dry process, e.g. arc process or the like, which reducts a mixture of silicon sand and coke by arc and then oxidizes it. It is favorable that the particle size is usually about 0.1-50 μm in the second particle diameter. In addition to (A) the dry process silica, (B) water or a mixed solvent containing water, (C) an active ingredient (e.g. phenothrin or the like) and (D) an aerosol propellant (e.g. liquefied petroleum gas or the like) are preferably added to the above composition in properties of 6-90 wt.%, 0.05-3 wt.% and 5-90 wt.%, respectively.