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Throughout their life cycles—from production, usage, through to disposal—materials and products interact with the environment (water, soil, and air). At the same time, they are exposed to environmental influences and, through their emissions, have an impact on the environment, people, and health. Accelerated experimental testing processes can be used to predict the long-term environmental consequences of innovative products before these actually enter the environment.
We are living in a material world. Building materials, geosynthetics, wooden toys, soil, nanomaterials, composites, wastes and more are research subjects examined by the authors of this book. The interactions of materials with the environment are manifold. Therefore, it is important to assess the environmental impact of these interactions. Some answers to how this task can be achieved are given in this Special Issue.
One criterion to evaluate the odour of a sample is perceived
intensity П which is evaluated with the aid of a comparative scale. The procedure is well accepted but also time consuming and extensive. The study should help simplify the testing procedure by asking the panel members to only indicate whether a sample is perceived as less to equally intense or of greater intensity in comparison to a given acetone concentration of 7 pi on the comparative scale. In Germany a value of 7 pi is required for products to be suitable for the indoor use. The results show that the simplified test is basically suitable.
Summary: A screening test for potential emissions of volatile organic compounds (VOC) was run on different thermoplastic filaments used for 3D printing. The method of direct thermal desorption was used to simulate the high temperatures during the 3D printing process and to identify the main compounds emitted from the filaments. A large number of unexpected compounds were detected that might affect the user’s health and have an impact on indoor air chemistry.
Introduction: The use of desktop 3D printers is increasing. Compared to other devices with known emissions, e.g. laser printers, there is still a lack of information on possible emissions of VOC and ultrafine particles during operation and the effect on indoor air quality. Most of the commercially available desktop 3D printers operate with a molten polymer deposition. For this process a solid thermoplastic filament is heated in an extrusion nozzle. Most filaments for desktop 3D printers use either acrylonitrile butadiene styrene (ABS) or polylactic acid (PLA) as filament. Alternatives are polyvinyl alcohol (PVA) or polycarbonate (PC).
Method: Eight different thermoplastic filaments for 3D printers were analysed by direct thermal desorption followed by GC-MS identification of the emitted substances. Direct thermal desorption was done by desorbing 5 mg of the feedstock for 1 minute at a temperature of 210°C. This is an average temperature for 3D printing with thermoplastic filaments.
Results and conclusions: The comparison of the 4 different filament groups showed the highest overall emissions from ABS, followed by PLA, PC and PVA. Filament ABS 2 emitted mainly SVOCs and triphenyl phosphate, the latter has the highest emission for a single compound from all evaluated filaments.
Thermoplastic filaments are a new source of VOC emissions due to the high temperatures associated with 3D printing, which can reach up to 270°C. Some of the detected compounds like lactic acid, lactide and bisphenol A have never been described before in the indoor environment. Additionally some of the main substances could not be identified and some others might have the potential to affect the indoor air chemistry.
The appearance of some newly detected compounds raises concerns about potential health effects for the users of 3D printers at home.
The lecture gives information about analytical methods for the determination of volatile organic compounds (VOC) and especially the equipment at BAM division 4.2. Examples are given for chamber test measurements and thermal extraction of materials. A special focus is put on chemical and particle emissions during 3-D-printing with thermoplastic filaments.
Samples of 474 forest stands in Germany were analysed for concentrations of polycyclic aromatic hydrocarbons (PAHs) in three sampling depths. Enhanced concentrations were mainly found at spots relatively close to densely industrialized and urbanized regions and at some topographically elevated areas. Average enrichment factors between mineral soil and humic layer depend on humus type i.e. decrease from mull via moder to mor. Based on their compound-patterns, the observed samples could be assigned to three main clusters. For some parts of our study area a uniform assignment of samples to clusters over larger regions could be identified. For instance, samples taken at vicinity to brown-coal strip-mining districts are characterized by high relative abundances of low-molecular-weight PAHs. These results suggest that PAHs are more likely originated from local and regional emitters rather than from long-range transport and that specific source-regions can be identified based on PAH fingerprints.
Building products: Determining and avoiding pollutants and odours - Results from a research project
(2007)
In this study 50 construction products were tested in emission test chambers according to the requirements of the AgBB-scheme: 7 acrylic and 6 silicone sealants, 6 paste-like synthetic resin plasters, 13 wood based products, 4 adhesives, 5 lacquers, 6 wall paints and 3 further construction products. VOC and odour emissions were tested on the 1st, 3rd, 10th, and 28th day. In addition to the VOC-measurements, a test procedure was developed to evaluate odour emission of construction products.This test is planned to be implemented into the AgBB-Scheme. A direct evaluation by a sensory panel in the emission test chamber was not possible. So the odour samples were collected in 300- litre tedlar bags which were evaluated later. Odour intensity of the samples was compared with different acetone concentrations. Within this study an interlaboratory comparison was conducted using the newly developed odour test method. Additionally, VVOC emissions, detection of carcinogenic compounds, repeatability of emission test chamber tests, and other issues are presented. This project has shown that construction products can be evaluated in accordance with the AgBB scheme. A sensory evaluation is intended to be introduced in the AgBB scheme. A method for this evaluation is described in this study. The test procedure should be enhanced and validated for practical utilisation.
Drucker, Kopierer und Multifunktionsgeräte können zu einer Schadstoffbelastung der Innenraumluft beitragen. Insbesondere Staub, Ozon und flüchtige organische Verbindungen (VOC, Volatile Organic Compounds) werden beobachtet. Geräte mit besonders geringen Emissionen, die weitere umweltrelevante Anforderungen einhalten, können mit dem Umweltzeichen Blauer Engel ausgezeichnet werden. Die Vergabegrundlage für den Blauen Engel begrenzt neben den genannten Stoffen auch noch speziell die Emission von Benzol und Styrol, und sie enthält die Prüfvorschrift zur Bestimmung der Emissionen. In der vorliegenden Publikation werden Ergebnisse von Emissionsmessungen an 57 verschiedenen Geräten unterschiedlicher Hersteller aus den Jahren 2003 bis 2004 vorgestellt. Ein besonderer Schwerpunkt liegt hierbei neben der Darstellung der summarischen VOC-Emissionen (TVOC, Total Volatile Organic Compounds) auf den wichtigsten Einzel-VOC, wie z.B. Benzol, Styrol, Phenol, Xylole. Diese für Drucker und Kopierer typischen Verbindungen ließen sich mit Emissionsraten von bis zu einigen Milligramm pro Stunde feststellen. Zusätzlich traten auch Siloxane mit vergleichbaren Raten auf, die bisher als Emissionen aus Druckern und Kopierern nur wenig Beachtung fanden. In einigen Fällen waren hohe Emissionen an VOC, die sich einer ausreichenden Identifizierung entzogen, feststellbar. Aus den ermittelten Emissionsraten wurden für einen Modellraum mögliche resultierende Raumluftkonzentrationen berechnet. Diese Berechnungen setzen voraus, dass Emissionen nicht den gesamten Tag über erfolgen, sondern unter üblichen Nutzungsbedingungen über maximal 10% des Arbeitstages. Für Emissionen der druckbereiten Geräte hingegen wurde eine Belastung über den ganzen Tag zugrunde gelegt. Ergänzend werden Emissionsraten für Ozon und Staub vorgestellt.
English:
Hardcopy devices like printers, copiers and multifunctional devices contribute to indoor air pollution. Low emitting devices, that fulfil additional environment related requirements, can be labelled with the eco label "Blue Angel". It limits emissions of benzene, styrene, TVOC, dust and ozone. Results are given for 57 different devices investigated during the years 2003 and 2004. Additionally to TVOC, benzene and styrene further information is given for other emitted VOC like phenol and xylenes. These typical VOC showed emission rates up to some mg/ h but some more uncommon VOC like siloxanes were found in a comparable range, too. In some cases high emission rates were found for compounds which could not be identified. The measured emission rates were taken to calculate indoor air concentrations for a typical situation. For this purpose it was considered that printing is normally limited to less than 10 % of a working day whereas emissions from the stand by phase occur all day long. In addition emission rates for ozone and dust are presented.
Emissions from Materials
(2006)