Information on the environmentally dangerous properties of chemicals is of fundamental importance if the users of chemicals are to take account of the risks to the environment in their choice of chemical products, and to organize the use of chemicals and waste disposal in an environmentally safe manner. In order to assist suppliers of chemicals in setting out their product informations and to ensure its consistency, it is important to have rules on classification and labelling. Such rules must be based on ciriteria for environmental hazard classification. During th 1980s specific classification criteria for the aquate environment were developed in the Nordic countries and by the Commission of the European Communities. These criteria now form the basis for the regulations on classification and labelling of chemical substances in both the EC and EFTA countries. The regulations entered into force in the EC on 1 July 1992 and will be enforced in the EFTA countries as soon as possible.