The present invention relates to a foam reduction agent comprising low vapor pressure dibasic esters and a method of using a liquid to contact with polystyrene foam wherein the higher boiling temperature of the low vapor pressure dibasic esters and contact with the liquid provides a volume reduction process and less evaporation loss as well as safer transportation of the chemicals and the polystyrene in its reduced state. The resulting reduced sludge is also recyclable to superior quality raw polystyrene foam beads and the reduction agents are recoverable for future use. The resulting sludge also has unexpected beneficial uses heretofore unknown as a waterproofing agent, a paint stripper, as a graffiti remover, as an extender of the life of concrete, as an adhesive remover, as a stain remover, as a scuff mark remover, and as a general degreaser.