TY - JOUR A1 - Wilke, Olaf A1 - Horn, Wolfgang A1 - Richter, Matthias A1 - Jann, Oliver T1 - Volatile organic compounds from building products - Results from six round robin tests with emission test chambers conducted between 2008 and 2018 N2 - Emission testing of volatile organic compounds (VOC) from materials and products is commonly based on emission test chamber measurements. To ensure the comparability of results from different testing laboratories, their measurement performance must be verified. For this purpose, Bundesanstalt für Materialforschung und -prüfung (BAM) organizes an international proficiency test (round robin test, RRT) every two years using well-characterized test materials (one sealant, one furniture board, and four times a lacquer) with defined VOC emissions. The materials fulfilled the requirements of homogeneity, reproducibility, and stability. Altogether, 36 VOCs were included of which 33 gave test chamber air concentrations between 13 and 83 µg/m3. This is the typical concentration range to be expected and to be quantified when performing chamber tests. Three compounds had higher concentrations between 326 and 1105 µg/m3. In this paper, the relative standard deviations (RSD) of BAM round robin tests since 2008 are compared and the improvement of the comparability of the emission chamber testing is shown by the decrease of the mean RSD down to 28 % in 2018. In contrast, the first large European interlaboratory comparison in 1999 showed a mean RSD of 51 %. KW - Construction product KW - Emission test chamber KW - Interlaboratory comparison KW - Proficiency testing KW - Rround robin test KW - VOC emission PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-526139 DO - https://doi.org/10.1111/ina.12848 VL - 31 IS - 6 SP - 2049 EP - 2057 PB - Wiley AN - OPUS4-52613 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hofmann, Michael A1 - Richter, Matthias A1 - Jann, Oliver T1 - Use of commercial radon monitors for low level radon measurements in dynamically operated VOC emission test chambers N2 - Compared to the intended EU reference level of 300 Bq m−3 for indoor radon concentrations, the contribution of building materials appears to be low. Considering the recommended limit of 100 Bq m−3 by WHO, their contribution is supposed to be relevant, especially at low air exchange rates. This study as part of a two-part research project investigated the suitability of direct low level 222Rn measurement under simulated indoor conditions with commercial radon monitors and dynamically operated emission test chambers. Active measuring devices based on ionisation or scintillation chambers with 1-σ uncertainties below 8.6% at 20 Bq m−3 were found to be best suitable for a practical test procedure for the determination of radon exhalation rates of building materials. For the measurement of such low concentrations, the knowledge of the accurate device background level is essential. KW - Radon monitors KW - Radon exhalation KW - Building materials KW - Measurement method PY - 2017 DO - https://doi.org/10.1093/rpd/ncx137 SN - 1742-3406 SN - 0144-8420 VL - 177 IS - 1-2 SP - 16 EP - 20 PB - Oxford Academic AN - OPUS4-41952 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Grimmer, Christoph A1 - Richter, Matthias A1 - Neuhaus, T. A1 - Prinz, Carsten A1 - Strzelczyk, Rebecca Skadi A1 - Colakoglu, Irem A1 - Horn, Wolfgang T1 - Towards a multi-VOC emission reference material with temporally constant emission profile for QA/QC of materials emission testing procedures N2 - Emission reference materials (ERMs) are sought after to further control and improve indoor air quality. The impregnation of porous materials with volatile organic compounds (VOCs) is a promising approach to produce ERMs. Different VOCs were used to impregnate various porous materials (mainly zeolites, activated carbons and a metal organic framework). The influence of different methodological parameters and material properties were studied to optimize the impregnation procedure and to find the best material/VOC combination. The impregnation procedure remains quite irreproducible, nevertheless, very good ERM candidates were identified. Two materials (zeolite 4 and AC 1 impregnated with n-hexadecane) showed a very stable emission over 14 days (<10 % change). Another material (AC 1 impregnated with toluene) showed a declining emission profile but with a very good in-batch reproducibility and a storage stability of up to 12 months. KW - Emission reference material KW - Porous materials KW - Indoor air quality KW - Emission test chamber KW - CO2 assisted impregnation KW - EN 16516 PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-612238 DO - https://doi.org/10.1016/j.chemosphere.2024.143437 SN - 1879-1298 VL - 366 SP - 1 EP - 8 PB - Elsevier AN - OPUS4-61223 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Richter, Matthias A1 - Jann, Oliver A1 - Horn, Wolfgang A1 - Pyza, Lars A1 - Wilke, Olaf T1 - System to generate stable long-term VOC gas mixtures of concentrations in the ppb range for test and calibration purposes N2 - The development of a gas mixing system (GMS) that enables dynamic and retraceable production of stable long-term VOC gas mixtures within the ppb range is discussed. In this system pure liquid substances are kept separately at a constant temperature, evaporated according to their vapour pressure and removed by a small inert gas flow. A modular set-up allows flexible handling. All vapours generated are finally united in a mixing chamber. Any concentration level of the gas mixture can be produced by a suitable combination of evaporation temperature, carrier and dilution gas flows. Test results from continuous operation over six weeks are presented. The equipment was tested on seven volatile organic compounds (VOC) of different vapour pressure ranges. It was possible to establish stable operation for the equipment during the entire period and reproducible gas concentrations which were traceable to the mass as an SI unit, thus the system is suitable for long-term tests.--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Im Beitrag wird die Entwicklung eines Gasmischsystems (GMS) beschrieben, das die dynamische und rückführbare Generierung von langzeitstabilen VOC-Gasgemischen im ppb-Bereich erlaubt. Dabei werden Reinsubstanzen separat temperiert, ihrem Dampfdruck entsprechend verdampft und durch einen kleinen Inertgasstrom abgeführt. In einer Mischkammer werden sie schließlich zusammengeführt. Durch die Kombination von Verdampfungstemperatur, Träger- und Verdünnungsgasflüssen ist die Einstellung eines beliebigen Konzentrationsniveaus des Gasgemischs möglich. Aus einem Dauerbetrieb von sechs Wochen werden Untersuchungsergebnisse gezeigt. Dabei wurde die Apparatur mit insgesamt sieben flüchtigen organischen Verbindungen (VOC) unterschiedlicher Dampfdruckbereiche betrieben. Die Anlage lief über den gesamten Zeitraum stabil und lieferte reproduzierbare und auf die Masse als SI-Einheit rückführbare Gaskonzentrationen. Somit ist das Verfahren für Langzeitanwendungen geeignet. KW - Gas mixing system KW - VOC gas mixtures KW - Low gas concentrations KW - Evaporation KW - Dynamic gas generation PY - 2013 SN - 0949-8036 SN - 0039-0771 SN - 1436-4891 VL - 73 IS - 3 SP - 103 EP - 106 PB - Springer-VDI-Verl. CY - Düsseldorf AN - OPUS4-27903 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Even, Morgane A1 - Juritsch, Elevtheria A1 - Richter, Matthias T1 - Selection of gas standards, gas chromatography column and adsorbents for the measurement of very volatile organic compounds (C1–C6) in indoor air N2 - The ISO 16000-6 standard gives directions to adapt the analysis of volatile organic compounds (VOCs) in indoor and test chamber air to very volatile organic compounds (VVOCs). The same techniques with sorbent-based active sampling, thermal desorption and gas chromatography coupled with mass spectrometry (TD-GC/MS) should be used. However, VVOCs require gaseous standards, an adapted GC column and a reliable sampling adsorbent. This work presents experimental results to tackle those three experimental gaps. A stable standard gas mixture containing 47 VVOCs, 13 VOCs and an internal standard was successfully generated. It was employed to study the suitability of seven types of chromatography columns. The use of PLOT (Porous Layer Open Tubular) columns such as PoraBOND Q is well suitable for VVOC analysis. The recoveries of the 60 analytes on a total of 16 adsorbents and their combinations were determined: A combination of the graphitized carbon black Carbograph 5TD 40/60 and the carbon molecular sieve CarbosieveTM SII showed great recoveries for all analytes. Carbon molecular sieves adsorb water which can impair the analysis. A dry purge of the multi-sorbent in the sampling direction led to a complete water removal and promising recoveries of the analytes. KW - VVOC KW - VOC KW - ISO 16000-6 KW - Gas chromatography KW - Thermal desorption KW - Air sampling PY - 2023 DO - https://doi.org/10.1016/j.aca.2022.340561 SN - 0003-2670 VL - 1238 SP - 1 EP - 12 PB - Elsevier B.V. AN - OPUS4-56366 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hofmann, Michael A1 - Richter, Matthias A1 - Jann, Oliver T1 - Robustness validation of a test procedure for the determination of the radon-222 exhalation rate from construction products in VOC emission test chambers N2 - This study investigated the adaptation of the state-of-the-art test procedure for the determination of emissions of volatile organic compounds (VOC) from materials into indoor air to test for the radon exhalation from stony construction products. A complete robustness validation including all relevant parameters showed that the procedure can be well applied by testing institutes already holding available the required VOC testing infrastructure that solely needs to be complemented by calibrated commercial radon measurement instrumentation. When measurements of the radon exhalation from construction materials become mandatory by law, test capacity can easily be applied. This work can serve as a recommendation for the European standardisation that still is on hold in this point. KW - Radon exhalation KW - Construction products KW - Emission test chamber KW - Robustness validation KW - Standardisation PY - 2020 DO - https://doi.org/10.1016/j.apradiso.2020.109372 SN - 0969-8043 VL - 166 IS - 109372 SP - 1 EP - 8 PB - Elsevier CY - Amsterdam AN - OPUS4-51145 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mull, Birte A1 - Sauerwald, T. A1 - Schultealbert, C. A1 - Horn, Wolfgang A1 - Brödner, Doris A1 - Richter, Matthias T1 - Reproducibly emitting reference materials for volatile and semi-volatile organic compounds—using finite element modeling for emission predictions N2 - Recent research into emissions of (semi-)volatile organic compounds [(S)VOC] from solid materials has focused on the development of suitable reference materials for quality assurance/quality control of emission test chamber measurements, which fulfill requirements such as homogenous and reproducible (S)VOC release. The approach of this study was to find a method for preparation of a material with predictable (S)VOC emission rates. AVOC (styrene) and an SVOC (2,6-diisopropylnaphthalene, DIPN), loaded into either vacuum grease or a 1:1 mixture of paraffin/squalane, have been tested. For the prediction of the emission rates, a model using the finite element method (FEM) was created to simulate the (S)VOC emission profiles. Theoretical and experimental results obtained in a Micro-Chamber/Thermal Extractor (μ-CTE™) and in 24 L emission test chamber measurements were in good agreement. Further properties were investigated concerning the material applicability, such as shelf life and inter-laboratory comparability. The maximum relative standard deviation in the inter-laboratory study was found to be 20%. KW - Emitting reference material KW - Emission test chamber KW - Micro-chamber KW - FEM model PY - 2017 DO - https://doi.org/10.1007/s11869-017-0508-6 SN - 1873-9318 SN - 1873-9326 VL - 10 IS - 10 SP - 1237 EP - 1246 PB - Springer Science+Business Media B.V. AN - OPUS4-41951 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Richter, Matthias A1 - Mull, Birte A1 - Horn, Wolfgang A1 - Brödner, Doris A1 - Mölders, N. A1 - Renner, M. T1 - Reproducibly emitting reference material on thermoplastic polyurethane basis for quality assurance/quality control of emission test chamber measurements N2 - Volatile Organic Compounds (VOC) are ubiquitous in the indoor air since they are emitted from materials used indoors. Investigations of these materials are mostly carried out in emission test chambers under controlled climatic conditions. Reference materials are an important tool for quality assurance/Quality control of emission test chamber measurements but so far they are not commercially available. In this study, a new approach was tested to develop an appropriate reference material with homogenous and reproducible emission of the VOC with well measurable air concentrations in emission test Chambers larger than 20 L at air change rates of 0.5 - 1 /h. Thermoplastic Polyurethane (TPU) was selected as Matrix material which was impregnated with 2,2,4- trimethyl-1,3-pentanediol monoisobutyrate (texanol) as test VOC using compressed carbon dioxide. An optimization of the impregnation parameters such as temperature, pressure, time, VOC injection volume and TPU sample size was performed until the targeted area specific Emission rate (SERa) value was reached. Further aspects like process control, storage effects and correlation of the sample size to the emission rate were investigated. It was found that the SERa immediately after sample preparation were not reproducible between the batches but became unified 10 days after loading into the test chamber indicating the necessity of aging before use. SERa between 13,000 and 18,000 mg m-2 h-1 were obtained, and the impregnated materials could be well stored in aluminum-coated polyethylene foil for at least seven weeks without significant losses. Furthermore, the impregnation of styrene and the SVOC 2,6-diisopropylnaphthalene was tested. KW - Reference material KW - Emissions testing KW - Volatile organic compounds KW - Polymer material KW - CO2 assisted impregnation PY - 2017 DO - https://doi.org/10.1016/j.buildenv.2017.06.005 SN - 0360-1323 SN - 1873-684X VL - 122 SP - 230 EP - 236 PB - Elsevier AN - OPUS4-40646 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Musyanovych, A. A1 - Grimmer, Christoph A1 - Sadak, A. E. A1 - Heßling, L. A1 - Lüdicke, M. A1 - Bilsel, M. A1 - Horn, Wolfgang A1 - Richter, Matthias T1 - Polymer Capsules with Volatile Organic Compounds as Reference Materials for Controlled Emission N2 - Encapsulation of volatile organic compounds (VOCs) that could evaporate at a defined rate is of immense interest for application in emission reference materials (ERMs). Polyurethane/polyurea microcapsules with various VOC active ingredients (limonene, pinene, and toluene) were successfully produced by interfacial polymerization with Shirasu porous glass membrane emulsification in a size range between 10 and 50 μm. The effect of surfactant, VOC, monomer(s) type, and ratio has a great effect on the formulation process and morphology of capsules. The type of VOC played a significant role in the encapsulation efficiency. Due to the difference in vapor pressure and VOC/water interfacial tension, the formulation for encapsulation was optimized for each individual VOC. Furthermore, to achieve effective stability of the large droplets/capsules, a combination of ionic and nonionic surfactants was used. Optical and scanning electron microscopy, Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA), were used to characterize the optimized microcapsules. The results showed that the obtained microcapsules exhibited a spherical shape and core–shell morphology and featured characteristic urethane-urea bonds. The amount of encapsulated VOC ranges between 54 and 7 wt %. The emission tests were performed with the help of the emission test chamber procedure (EN 16516). The limonene-loaded polyurethane/polyurea microcapsules show a change in emission rate of less than 10% within 14 days and can be considered as a potential candidate for use as an ERM. KW - Polymer microcapsules KW - Membrane emulsification KW - Polyaddition KW - Volatile organic compound (VOC) KW - Emission testing PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-619227 DO - https://doi.org/10.1021/acsami.4c12826 SN - 1944-8252 VL - 16 IS - 50 SP - 69999 EP - 70009 PB - ACS AN - OPUS4-61922 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Even, Morgane A1 - Juritsch, Elevtheria A1 - Richter, Matthias T1 - On the use of Carbograph 5TD as an adsorbent for sampling VVOCs: validation of an analytical method N2 - A standardised method for the analysis of very volatile organic compounds (VVOCs) in indoor air is still missing. This study evaluates the use of Carbograph 5TD as an adsorbent for 60 compounds (47 VVOCs + 13 VOCs) by comparing their recoveries with different spiking modes. The influence of the spiking of the tubes in dry nitrogen, humidified air or along the whole flushing duration mimicking real sampling was investigated. 49 substances (36 VVOCs from C1 to C6) had recoveries over 70% on the adsorbent in humidified air and were validated. The linearity of the calibration curves was verified for every spiking mode and the limits of detection (LOD) and quantification (LOQ) were determined. The LOQs were lower than the existing indoor air guideline values. The robustness of the method was considered by studying the influence of the sampling volume, the sampling flow rate, the humidity level and the storage of the tubes. In general, the most volatile or polar substances were the less robust ones. The combined measurement uncertainty was calculated and lies below 35% for a vast majority of the substances. An example of an emission chamber test using polyurethane foam is shown: Carbograph 5TD performs much better than Tenax® TA for VVOCs and emissions from n-butane were quantified with combined measurement uncertainty. KW - VVOC KW - Gas chromatography KW - Thermal desorption KW - Air sampling PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-581113 DO - https://doi.org/10.1039/D3AY00677H VL - 15 IS - 31 SP - 3810 EP - 3821 AN - OPUS4-58111 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -