In 1993 the Belgian Government introduced product charges on drink containers, batteries, certain industrial packaging, paper and disposable razors and cameras. Simultaneously, an expert commission was installed to follow up the implementation process and to propose new ecotaxes. Because the preparation of the law was not well done and only limited knowledge and experience existed, the implementation encountered serious difficulties. The commission revised the law in a global and systematic way in co-operation with the actors involved: industry, environmentalists and the administration. The methodology that was followed is explained and some important conclusions with respect to the interaction between business, politics and science considered. There is a great gap between textbook theory and the realities of the implementation process.