Silica Gel Toxic? Silica gel is non-toxic but it is a choking hazard for young children. However, in some rare instances, manufacturers coat silica gel in cobalt chloride, a toxic compound
This silica gel is a bead or granule that has been washed with a concentration of cobalt chloride (a heavy metal salt).
Blue silica gel has cobalt chloride, which allows the blue silica gel change its color to pink when it reached its maximized adsorption capacity. Once pink it can be reactivated with heat to dry out the moisture. When it turns blue again, it's ready to use.