The FEhS Institute is calling for the total removal of minimum installation volumes where solid material limit values are used as an evaluation criterion. Legislators should instead focus on a strict application of the underlying principle, i.e. exclusively that the limit values for eluates must be complied with. “The important thing is what comes out of the construction materials, not what is in them,” says FEhS Director Thomas Reiche. “On this point, we agree with the Federal Ministry of the Environment. This principle now also needs to be implemented in the Replacement Building Material Ordinance in a standardised manner.” In addition, the limit values for vanadium, molybdenum and fluoride need to be adjusted, while retaining the previous fields of application. This applies in particular to the classification under the category “Steel slag 1” (SWS-1), because the market will in future only be sourcing these construction materials from the steel industry. Without jeopardising soil and groundwater protection, the SWS-1 values for vanadium can be increased to 300 µg/I, those for molybdenum can be increased to 200 µg/I, and those for fluoride can be increased to 2mg/I. Ultimately, unnecessarily strict limit values just end up sending resource-efficient construction materials to landfill. It is also important that the same investigation methods and test parameters are used throughout the installation and removal of mineral construction materials. Currently this is not case and often leads to a situation in practice that exceptionally suited construction materials made from industrial aggregates are not installed in the first place, because of totally harmless solid materials limit values that only become relevant during the eventual removal process. In this context, and viewed in terms of circular economy and resource efficiency, strict categorisation as “waste” or “by-products” is counter-productive. Dividing the construction materials into two groups (SWS-1 = by-product and SWS-2/SWS-3 = waste) will furthermore mean that materials will have to be examined numerous times using different methods, because e.g. different methods exist for determining leachability in the context of use or landfill. “We urgently need to bring about these changes to the Replacement Building Material Ordinance. Otherwise, 2 million tonnes of steel slag will be withdrawn from their current use as transport construction materials! This represents 40% of the volume previously used in transport construction! Quite apart from the shortfall in availability and the insupportable costs of dumping this high-quality construction material in landfill, serious questions must be raised about the environmental policy rationale behind this development,” says FEhS Director Reiche.