TY - GEN A1 - Schröder, Volkmar T1 - Calculation of Flammability and Lower Flammability Limits of Gas Mixtures for Classification Purposes N2 - ISO 10156:2010 contains a test method and a calculation method for flammability of gases and gas mixtures for the selection of cylinder valve outlets. The calculation method is used also to classify gas mixtures according to the national and international dangerous goods and dangerous substances regulations, e.g. according to the UN Recommendations on the Transport of Dangerous Goods (UN TDG) and the Globally Harmonized System of Classification and Labelling of Chemicals (UN GHS). The calculation method for gas mixtures requires substance parameters of the single components. These are the coefficients for the fire potential (Tci) and for inerting ability, the so-called nitrogen equivalence (Kk), which have been estimated conservatively by means of flammability data. BAM checked Tci and Kk values of ISO 10156:1996 using three-component diagrams (Flammable gas-Inert-Air) of the CHEMSAFE® database. The experimental fundamentals and the principles of the calculation method are summarized in this paper. The revised data for Tci and Kk values were adopted in the tables of ISO 10156:2010. Furthermore, subcategorization of flammable gases has been proposed by a UN working group and shall be implemented in the GHS in the meantime. The subcategorization requires the lower flammability limit (LFL) as an additional indicator. Therefore, a test method and a calculation method for LFL were proposed by BAM and have been implemented in the new draft of ISO/CD 10156:2016. The calculation method for gas mixtures is based on Le Chatelier’s rule and was extended by using the Kk values for inert components in the mixture. The calculated LFLs of methane-inert gas mixtures were compared with experimental values for different types of inert gases. It could be shown that calculated LFLs are in good agreement with experimental values if the Kk values derived from three-component flammability diagrams are used. Although using the Kk values of ISO 10156:2010 leads to higher deviations, the results are still on the safe side. KW - Gas Mixtures KW - GHS Classifikation KW - Flammability KW - Flammability Limit KW - Calculation method PY - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-418306 SP - 1 EP - 17 PB - Bundesanstalt für Materialforschung und -prüfung (BAM) CY - Berlin AN - OPUS4-41830 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -