Physical-chemical evaluation methods come up against their limits when the effects of photocatalytic processes have to be determined on biological systems. For this, microbiological methods are required which allow degradation reactions, inactivation processes and environmental effects to be recorded under defined conditions. Bacteria, fungi and algae are used as the biological test systems.
Evaluation of the environmental compatibility of the coatings involves carrying out tests based on the standardized methods which are used for soil, surface water and groundwater protection. These tests have been adapted for the specific needs of photocatalysis. It must be ensured that there are no negative long-term effects even when there is large-area application of a coating.
Further information can also be found on the websites of the Fraunhofer IGB.