Kritische emissiewaarden voor bouwstoffen. Milieuhygienische onderbouwing en consequenties voor bouwmaterialen

This report presents alternative emission limit values for inorganic components to be used in the revision of the Building Materials Decree (1999) in the Netherlands. Three key factors determine the emission limit value: (1) the environmental compartment under consideration, with its dimensions and the accounted for, (2) the desired level of environmental protection and (3) the scenario applying to the intended use of the construction material. Emission limit values have been derived here from modelled concentrations in soil, groundwater and surface water. The desired level of protection has been elaborated as a stand-still approach (based on quality target values and a risk-based approach (based on PNECs). Two exposure models were used for taking the effects of a time-dependent exposure of the soil to leached components into account, for vertical transport through the soil profile and for retardation of components in the soil profile. The PEARL model was used for binding described by equilibrium adsorption. The ORCHESTRA model was used for binding that also takes speciation into account. For surface water, a dilution factor was computed assuming a certain mixing zone, dependent on the size of the surface water. The consequences of the proposed alternative emission limit values have been estimated on the basis of information in a database containing results of leaching tests for construction materials. The alternatives proposed form the basis for a political decision-making process, where environmental protection will be balanced with other socio-economic concerns.