In a circular economy, building materials have a longer life cycle and are reused in innovative ways. Reusing building materials is sustainable, but can also be risky as building materials may contain contaminants such as heavy metals. To prevent negative effects on soil quality, critical emission limit values were derived in the past. These values specify the amount of a contaminant that can leach without causing adverse effects. In this report, the methodology used in the past by the RIVM is described. Additionally, a preliminary investigation into the influence of building material properties and application on critical emission limit values is presented.
Reuse of building materials
The Netherlands is working on building a circular economy by 2050. This entails a reduction in waste production and an increase in the reuse of materials. Building materials would consequently be in use for longer periods of time and reused in new ways. An example of reuse is the application of rubble as road foundation. To prevent negative effects on the quality of soil and groundwater, critical emission limit values were established.
In this report, the RIVM describes how the values were derived in the past. The RIVM has restored its knowledge on the method used to derive critical emission limit values. With this knowledge, the RIVM can advise the ministry about old and new emission limit values.
New materials and applications
The critical emission limit values were derived using a standard use case. However, the use of new materials and novel applications means that effects on the environment may be over or underestimated by current limit values. The RIVM thus conducted a preliminary investigation into the influence of different use cases on derived critical emission limit values. A more in-depth investigation will be completed in 2024.
Recommendations for further research
The RIVM presents several recommendations for further research. These include investigating how different building materials are used in practice, and deriving separate critical emission limit values for the most used building materials. A further recommendation is to consider a time frame longer than the 100 years on which the current emission limit values are based.
Foundation for the Soil Quality Decree
The critical emission limit values are the foundation for legal norms in the Soil Quality Decree. To apply a building material on soil, they need meet these legal norms.