The German Environment Agency (UBA) published a study “Building and renovation as a source of pollutants in the urban environment”, focusing on potential leaching of substances from the construction materials of the building envelope. The results demonstrate that rain may contribute to leachability of biocides and inorganic substances into the environment, although the study keeps an open question on whether “leaching from new construction or redevelopment areas leads to the exceedance of environmental quality targets in urban surface waters”.
It is worth noting that in facade runoff, all of the active ingredients used for film protection in the applied plasters and facade paints were found in high concentrations. However, as underlined by UBA, commonly used in-can preservative MIT/BIT quickly degraded in the water, after being washed out.
In addition, German authorities developed guidelines and factsheets summarising measures to avoid and reduce the entry of environmentally relevant substances from building products, highlighting that “good active ingredient embedding through encapsulation and the optimized overall formulation of a building product can reduce the release”.