This European Standard specifies the properties of aggregates obtained by processing natural, manufactured or recycled materials and mixtures of these materials for use as armourstone. A list of the source materials that have been considered and are within the scope of this European Standard is given in Annex A (normative). Requirements for the evaluation of conformity of the products to this European Standard are given in EN 16236. It incorporates a general requirement that armourstone shall not release any dangerous substances in excess of the maximum permitted levels specified in a relevant European Standard for the material or permitted in the national regulations of the member state of destination. Armourstone used in construction should comply with all the requirements of this European Standard. The standard includes specific requirements for natural armourstone, and armourstone made of blast furnace and steel making slag armourstone. For materials from some other secondary sources, however, work is ongoing and the requirements are incomplete. In the meantime, such materials, when placed on the market as armourstone, should comply fully with this European Standard but may also be required to conform to specific relevant additional requirements at the place of use. Additional characteristics and requirements may be specified on a case by case basis depending upon experience of use of the product, and defined in specific contractual documents. Finer aggregates than specified in this European Standard are used in hydraulic structures. For such aggregates, European Standards for other end uses of aggregates should be applied. Requirements for the declaration of the potential of armourstone to release regulated dangerous substances are currently under development. Until such time as these are finalised, attention should be paid to requirements at the place of use.