Abstract: A diphase drain cleaning composition and method wherein the composition has two liquid layers. The lower, denser layer makes up from 50 to 99 percent of the total composition weight while the upper, less-dense layer makes up from 1 to 50 percent of the total composition weight. The lower layer consists of at least 20 percent sulfuric acid solution. The upper layer consists of a halogenated aliphatic hydrocarbon polystyrene solvent and, optionally, fully saturated aliphatic hydrocarbons. The composition attacks drain blockage consisting of polystyrene and other organic and inorganic matter in two phases. First, the lower layer of sulfuric acid contacts the blockage and melts and dissolves many organic and inorganic materials. Second, loosened polystryene, which is not affected by the sulfuric acid, floats to the upper layer where it is dissolved by the solvent making up the upper layer.

Abstract: A diphase drain cleaning composition and method wherein the composition has two liquid layers. The lower denser layer makes up from 50 to 99 percent of the total composition weight while the upper less-dense layer makes up from 1 to 50 percent of the total composition weight. The lower layer consists of at least 20 percent sulphuric acid solution. The upper layer consists of an aromatic hydrocarbon solvent such as dichlorobenzene or monochlorotoluene. The composition attacks drain blockage consisting of polystyrene and other organic and inorganic matter in two phases. First, the lower layer of sulphuric acid contacts the blockage and melts and dissolves many organic and inorganic materials. Second, loosened polystyrene, which is not affected by the sulphuric acid, floats to the upper layer where it is dissolved by the solvent making up the upper layer.