Levasil CB45 A is an alkaline, aqueous dispersion of colloidal silica that is approximately 15% solids by weight. The silica dispersion is sodium stabilized and the amorphous silica particles carry a negative surface charge. The silica particles are structured to enhance the activity of the dispersion. The particles have also been surface modified with aluminum. The physical appearance of the dispersion is a clear liquid, slightly more viscous than water. Levasil CB45 A is produced for world-wide distribution.