Properly implemented environmental protection can prove to be an economically sound and profitable approach for processing and manufacturing industry. This requires an integrated approach with a systematic consideration, and consequent reduction, of the formation of waste products and emissions. This paper proposes a system for categorisation of the starting materials of production and for classification of waste and emission flows, and an answering strategy based thereon. Avoidance and reduction of emissions can be achieved in four ways : increasing efficiency, increasing effectiveness, utilisation of by-products, and substitution of starting materials. Combination of material-flow analysis with a complete plant environmental cost calculation helps to clarify the economic benefits of production-integrated environmental protection. More than 100 case studies conducted within the framework of cleaner production programs in Austria demonstrated the soundness and feasibility of thes approach.