title: Release and environmental impact of silver nanoparticles and conventional organic biocides from coated wooden façades.
abstract: This study represents for the first time a comprehensive assessment of functionality and environmental impacts of metallic silver nanoparticles (Ag-NP) compared to conventional organic biocides. Four different transparent, hydrophobic coatings of wooden outdoor façades were tested during one year outdoor weathering. The total silver release from products with Ag-NP was proportional to the overall erosion of the coating. The results indicate that the Ag-NPs are likely transformed to silver complexes, which are considerably less toxic than ionic silver. The protective effect of the silver containing coatings against mold, blue stain and algae was insufficient, even in immaculate and non-weathered conditions. The release of organic biocides from conventional coatings was dependent on the weather conditions, the type of biocide and the use in the base or top coat. The conventional coating showed a good overall performance free from mold, blue stain and algae until the end of the test period.
authors.affiliation: Empa, Swiss Federal Institute for Materials Science and Technology, Überlandstrasse 129, 8600 Dübendorf, Switzerland. Electronic address: tina.kuenniger@empa.ch.
authors.forename: Tina
authors.initials: T
authors.lastname: Künniger
authors.forename: Andreas C
authors.initials: AC
authors.lastname: Gerecke
authors.forename: Andrea
authors.initials: A
authors.lastname: Ulrich
authors.forename: Anja
authors.initials: A
authors.lastname: Huch
authors.forename: Roger
authors.initials: R
authors.lastname: Vonbank
authors.forename: Markus
authors.initials: M
authors.lastname: Heeb
authors.forename: Adrian
authors.initials: A
authors.lastname: Wichser
authors.forename: Regula
authors.initials: R
authors.lastname: Haag
authors.forename: Petra
authors.initials: P
authors.lastname: Kunz
authors.forename: Markus
authors.initials: M
authors.lastname: Faller
mesh_terms: D004202:Disinfectants / Q000633:toxicity*; D004777:Environment; D007477:Ions; D053768:Metal Nanoparticles / Q000737:chemistry / Q000633:toxicity*; D008956:Models, Chemical; D018570:Risk Assessment; D012834:Silver / Q000032:analysis* / Q000737:chemistry / Q000633:toxicity; D014887:Weather; D014934:Wood
chemical_list: D004202:Disinfectants; D007477:Ions; D012834:Silver
keywords: Organic biocide; Silver nanoparticle; Storm water runoff; Wood coating