The eco audit directive of the Europen Union (EEC 1836/93) requires that a company applying for certification should lay open its environmental policy, install enviromental management, and conduct an internal environmental analysis. It can be demonstrated that the investments required to eliminate weak points is often recovered within a few years owing to savings relating to energy and fresh an waste water. The same can be expected for other sectors of industry. A prerequisite is a holistic approach and integration of the measures adopted into the production line. Selective separation processes play a special role in practical application of the information acquired.