Nano particles are increasingly used in facade coatings (easy to clean, self-cleaning coatings). The most common nano particles include nanosilver and photocatalytically active nano titanium oxide.
The washout of nanosilver from building facade colours due to precipitation and erosion may lead to the release of pollutants and their transport to creeks, rivers and lakes. The Ecotox Centre investigates the ecotoxicological effects of facade drainage on various organisms such as macroinvertebrates, algae and bacteria. The test results are interpreted in collaboration with the Eawag Department of Urban Water Management, which characterises the washout-relevant aspects and quantifies the washed-out pollutants and/or particles.
The washout of pollutants from the facade colour is analysed by comparing the drainage from building facades that are painted with commercially available colour containing nanosilver with a silver-free reference colour. The tests are performed in the field and in the laboratory with artificial sprinkling.
Applied test systems
- Luminescent bacteria test with the marine bacterium Vibrio fischeri
- Combined Algae Test with Pseudokirchneriella subcapitata
- Acute toxicity test with Gammarus fossarum
- Chronic toxicity test with Ceriodaphnia dubia