Treatment by stabilisation/solidification (S/S) with cement-based binders is an option for wastes from the chemical and metal industries that can not be prevented or reduced. This project aimed to develop process envelopes for generic S/S of the most common or problematic residual waste types and gain a better understanding of contaminant immobilisation mechanisms and longterm performance. The intention was to increase technology transparency to allow an informed choice between treatment options, guide use and marketing of S/S by industry, prevent technology failures, enable confident approval of S/S by regulators, and provide fundamental data for development of predictive models of longterm behaviour for risk assessment. The depth and breadth of the rigorous testing programme has provided data to guide future technology development and enhance competitiveness in the global market.