The CE marking is necessary on products from 25 groups before they can be traded on the European market. By affixing the CE marking, the manufacturer certifies that the product complies with EU safety, health and environmental protection requirements. For some types of products, the self-check by the manufacturer is supplemented by the intervention of an independent body. The Belgian Court of Audit notes that despite those safeguards, products which do not comply with the essential requirements circulate on the market. Belgian market surveillance authorities carry out inspections and take consumer protection measures when non-compliant products are detected or when dangerous products are reported by other EU countries. They can take measures to limit movements of non-compliant products in the EU and impose to bring the products into conformity before being placed on the European market. However, enforcement powers of those authorities are restricted by national borders. The Belgian Court of Audit recommends to improve coordination and cooperation among the European market surveillance authorities, to enhance control reporting, to apply sanctions proportional to the seriousness of the infringements observed and to take into consideration the results of previous inspections in the future control planning.