TY - JOUR A1 - Schoknecht, Ute A1 - Mathies, H. T1 - The Impact of Weather Conditions on Biocides in Paints N2 - Weather conditions affect biocides on exposed outer surfaces on constructions. Contact with water causes hydrolysis and leaching of substances. Ultraviolet radiation may induce photolysis. As a result, a mixture of biocidal active substances and transformation products can be emitted into the environment. In a semi-field study, leaching of the biocidal active substances terbutryn, diuron, octylisothiazolinone, carbendazim, and selected transformation products was observed for two paints containing either a white or a red pigment. Painted test panels were exposed to natural weathering for about 1.5 years. Runoff samples were analyzed during the course of the experiment. At the end of the study, residues of biocidal active substances and transformation products were determined in sections of the test panels. Emissions of substances were mainly observed during the first few months of the experiments. Increased emissions of transformation products were observed during periods of increased global radiation and subsequent periods with relatively high amounts of driving rain. Different patterns of transformation products were observed, especially for terbutryn, both for paints containing different pigments and in experiments that were started in different periods of the year, as well as during different periods of the experiments. KW - Substance release KW - Construction products KW - Biocides KW - Transformation KW - Weathering KW - Driving rain KW - Global radiation PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-560651 DO - https://doi.org/10.3390/ma15207368 VL - 15 IS - 20 SP - 1 EP - 16 PB - MDPI CY - Basel AN - OPUS4-56065 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Piechotta, Christian T1 - Development, Validation and Application of an Accelerated Weathering Protocol for Assessing Bisphenol A Release from Polycarbonate Materials into the environment N2 - Bisphenol A (BPA) is under continuous regulatory scrutiny and listed as substance of very high concern (SVHC). Particular concern is related to its frequent detection in surface waters, despite being readily biodegradable. Several studies have been conducted to investigate sources and pathways of BPA in the environment, concluding that its main use as monomer in polycarbonate (PC) contributes only marginally to environmental BPA releases over its life cycle. To better understand the actual releases of BPA from PC under environmental conditions, a newly developed methodology (Federal Institute for Materials Research and Testing, BAM) was applied, which comprises a novel accelerated weathering protocol for polycarbonate (PC) materials, combined with an advanced analytical setup allowing for improved detection of BPA at trace level concentrations. The weathering protocol achieves a 13.6-fold acceleration compared to Central European outdoor conditions and simulates environmental stressors (global radiation, rain, temperature variations) in a laboratory weathering chamber, with simultaneous BPA release measurements using an organic isotope dilution calibration LC-MS/MS approach. Validation was performed in parallel outdoor exposure tests, by using haze and yellowness index measurements as reference parameters. PC sample types representative of major polycarbonate applications were examined: Samples with different levels of UV-protection as used in transparent sheets used outdoor in construction or housings in Electro- and Electronic applications as well as samples with a protective coating as used in automotive applications (headlamps, glazing and construction). Results demonstrated consistently low total BPA releases of around 0.3 mg m⁻² for samples with exposed PC surfaces, while releases from coated samples were significantly reduced by around two orders of magnitude. In all cases examined, the BPA release ceased to zero after a period of four to six weeks, equivalent to approximately 1 to 1.5 years of outdoor exposure. This suggests that potential BPA releases diminish to virtually zero after that timespan. While the newly developed test method is not suitable for routine laboratory implementation, it provides crucial quantitative data on BPA release from PC materials during accelerated environmental weathering. T2 - Umwelt 2025 CY - Dessau, Germany DA - 22.09.2025 KW - Bisphenol A KW - Polycarbonate KW - Weathering PY - 2025 AN - OPUS4-64664 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Piechotta, Christian T1 - Development, Validation and Application of an Accelerated Weathering Protocol for Assessing Bisphenol A Release from Polycarbonate Materials into the environment N2 - Bisphenol A (BPA) is under continuous regulatory scrutiny and listed as substance of very high concern (SVHC). Particular concern is related to its frequent detection in surface waters, despite being readily biodegradable. Several studies have been conducted to investigate sources and pathways of BPA in the environment, concluding that its main use as monomer in polycarbonate (PC) contributes only marginally to environmental BPA releases over its life cycle. To better understand the actual releases of BPA from PC under environmental conditions, a newly developed methodology (Federal Institute for Materials Research and Testing, BAM) was applied, which comprises a novel accelerated weathering protocol for polycarbonate (PC) materials, combined with an advanced analytical setup allowing for improved detection of BPA at trace level concentrations. The weathering protocol achieves a 13.6-fold acceleration compared to Central European outdoor conditions and simulates environmental stressors (global radiation, rain, temperature variations) in a laboratory weathering chamber, with simultaneous BPA release measurements using an organic isotope dilution calibration LC-MS/MS approach. Validation was performed in parallel outdoor exposure tests, by using haze and yellowness index measurements as reference parameters. PC sample types representative of major polycarbonate applications were examined: Samples with different levels of UV-protection as used in transparent sheets used outdoor in construction or housings in Electro- and Electronic applications as well as samples with a protective coating as used in automotive applications (headlamps, glazing and construction). Results demonstrated consistently low total BPA releases of around 0.3 mg m⁻² for samples with exposed PC surfaces, while releases from coated samples were significantly reduced by around two orders of magnitude. In all cases examined, the BPA release ceased to zero after a period of four to six weeks, equivalent to approximately 1 to 1.5 years of outdoor exposure. This suggests that potential BPA releases diminish to virtually zero after that timespan. While the newly developed test method is not suitable for routine laboratory implementation, it provides crucial quantitative data on BPA release from PC materials during accelerated environmental weathering. T2 - Umwelt 2025 CY - Dessau, Germany DA - 22.09.2025 KW - Bisphenol A KW - Polycarbonate KW - Weathering PY - 2025 AN - OPUS4-64665 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gerrits, Ruben T1 - Genetic engineering of melanised fungi to study the role of melanin in mineral weathering and metal corrosion N2 - Melanins are organic, dark pigments produced by many organisms. Fungi either fix these pigments in their cell wall or secrete them into their environment to protect themselves against an array of physicochemical stresses (e.g., UV irradiation, desiccation, ...). However, melanins can also adsorb metals like iron and therefore might have a role in the fungal capacity to deteriorate iron-containing minerals and metals. To study this, we focus on the fungi Knufia petricola, a rock-inhabiting fungus with melanised cell walls which deteriorates minerals, and Amorphotheca resinae, a soil-borne fungus able to secrete melanin, degrade alkane-containing fuels, and corrode metals. The broader significance of this work lies in the mitigation of climate change via the negative emission technology enhanced rock weathering for the former to the mitigation of corrosion of biofuel infrastructure for the latter. Genes of K. petricola involved in melanin synthesis and iron uptake were deleted and down- and up- regulated to generate strains with a different melanin content and ability to take up iron. These strains and the wild type (WT) were exposed to a growth solution containing the iron-magnesium silicate olivine of which dissolution rates were obtained by measuring aqueous Mg concentrations using ICP-OES. Thus, the specific mineral deterioration mechanisms of melanised fungi were identified. Abiotically, these experiments showed that iron oxidation at the surface inhibits olivine dissolution. K. petricola was able to enhance dissolution when this abiotic inhibition is strongest (at pH 6) but prevented dissolution when this inhibition is weakest (at pH 4). The fungus therefore dissolves olivine by interacting with the oxidised iron at the olivine surface. Its iron uptake pathways do not seem to be involved as mutants deficient in iron uptake dissolved olivine at the same rate as the WT. The higher dissolution rates of a mutant which secretes a melanin precursor and the lower rates of a melanin-deficient mutant, however, indicate that the iron-adsorbing and -reducing capacities of melanin play a key role. This hypothesis is further supported by carbon steel corrosion experiments with six strains of A. resinae isolated from anthropogenic and natural environments. Their varying ability to secrete melanin correlated with their corrosion rates. We now plan to develop CRISPR/Cas9-mediated genome editing techniques for A. resinae to figure out whether this correlation is also a causation. In summary, our data show that the iron-binding capacity of melanins enables fungi to deteriorate iron-containing substrates at a higher rate. T2 - IBBS19 CY - Berlin, Germany DA - 09.09.2024 KW - Black fungi KW - Weathering KW - Corrosion PY - 2024 AN - OPUS4-61171 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - von Werder, Julia T1 - Living Concrete Walls: Engineering Bioreceptivity and Biofilms N2 - Building envelopes are a natural habitat of subaerial biofilms and can be more or less prone to be colonized (i.e. to be bioreceptive). Focusing on the added value of biofilms on manmade substrates represents new aesthetic frontiers and reduces the use of biocides. Moreover, the metabolic processes of photosynthetic biofilms can positively influence human health and life quality in densely populated cities by converting or absorbing pollutants. In the presented research the bioreceptivity of concrete claddings for building facades is engineered to sustain either natural or artificial establishment of microalgae-dominated biofilms. To be able to differentiate between the intrinsic material properties and the climatic boundary conditions, the experimental design in the first step comprised different analyses with model mono- and multi-species biofilms in sterile conditions and a high control of the environmental parameters. Growth and vitality of the algal component of the biofilms has been assessed with Pulse-amplitude modulation (PAM) fluorometry. T2 - 78th RILEM Annual Week & RILEM International Conference on Sustainable Materials & Structures: Meeting the major challenges of the 21st century - SMS 2024 CY - Toulouse, France DA - 25.08.2024 KW - Bioreceptivity KW - Biofilm KW - Weathering KW - Concrete KW - PAM fluorometry KW - Carbonation PY - 2024 AN - OPUS4-62224 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -