This document specifies the requirements for chemical and physical characteristics of trass, which is used for the production of concrete or mortar. Provisions for the use of trass in concrete production, i.e. requirements for the concrete composition, the mixing process, the execution, the curing, etc. of conrete containng trass are not part of this document. Such provisions are part of other european or national standards, e. g. DIN 1045-2 for conrete.