Disclosed are methods for treating hazardous materials, such as those which result from an unwanted spill or leak, which comprise one or more of the steps or effects of: neutralizing the dispersed material; solidifying the dispersed material; immobilizing the material; and/or reducing the evolution of harmful or unwanted gaseous forms from the spillage, preferably using a binding agent which comprises a polyacrylate-polyacrylamide cross-linked copolymer.