91 International conference on practical applications in environmental geotechnology ecogeo 2000, Edited by Reijo Salminen. Geological Survey of Finland, Special Paper 32, 91–98, 2001. Sorvari, Jaana & Tenhunen, Jyrki 2001. Definition of environmental criteria for industrial by-products used in earth construction. Geologi- cal Survey of Finland, Special Paper 32, 91–98, one figure and 2 ta- bles. At present in Finland, Dutch methodologies and criteria are frequently employed in the environmental assessment of by-products used in earth construction. A study was initiated in order to develop a national code of practice. A hierarchical procedure including composition and solu- bility standards was elaborated. Derivation of solubility criteria (MPEs) was based on Dutch leaching models and Finnish target values of soil. Conservative risk assumptions were used as a starting point in the defi- nition of parameter values. Different MPE alternatives were created by altering the values of the parameters defining an acceptable load to soil. A risk-benefit analysis was executed by using a decision analysis (the SMART method) in order to identify the best MPE alternative. Land use, uncertainties in analytical methods and non-uniformity of the target val- ues (soil) were considered in the definition of the final MPE values. The proposed solubility standards differ slightly from the corresponding Dutch values. On the basis of the results of previous leaching tests, wa- ter-cooled blast-furnace slag and crushed concrete can be considered as readily recyclable, whereas most of the fly ashes from coal combustion could be used only in a monolithic i.e. prefabricated form. Keywords: construction materials, by-products, earthworks, risk assess- ment, solubility, standards, Finland Jaana Sorvari and Jyrki Tenhunen Finnish Environment Institute, P.O. Box 140, 00251 Helsinki, FINLAND, Fax +358 9 40300491 E-mail: Jaana.Sorvari@vyh.fi DEFINITION OF ENVIRONMENTAL CRITERIA FOR INDUSTRIAL BY-PRODUCTS USED IN EARTH CONSTRUCTION by Jaana Sorvari and Jyrki Tenhunen