TY - RPRT A1 - Kunath, K. A1 - Lüth, Peter A1 - Schmidt, Martin A1 - Simon, K. A1 - Uhlig, S. T1 - Evaluation of the interlaboratory test 2010-2011 on the method DIN EN15188:2007 'Determination of the spontaneous ignition behaviour of dust accumulations' N2 - For the classification and safe handling and use of the chemicals, special standardized testing proce-dures have been developed and are used world-wide. Safety experts must be able to fully rely on the precise execution of the respective laboratory tests and assessments. In this context interlaboratory tests (round robin tests, interlaboratory comparisons / intercomparisons) are a crucial element of a laboratory's quality system. Participation in interlaboratory tests is explicitly recommended by the standard ISO/IEC 17025. The present document reports on the results of the interlaboratory test 2010/2011 on the test method DIN EN 15188:2007 “Determination of the spontaneous ignition behaviour of dust accumulations” [1] which was organized by the Center for Quality Assurance for Testing of Dangerous Goods and Haz-ardous Substances. The test method DIN EN 15188:2007 is applied to characterize the self-ignition behaviour of combus-tible dusts. The experimental basis for describing the self-ignition behaviour of a given dust is the de-termination of the self-ignition temperatures (TSI) of differently-sized volumes of the dust sample by isoperibolic hot storage experiments (storage at constant oven temperatures) in commercially availa-ble ovens. The results thus measured reflect the dependence of self-ignition temperatures upon dust volume [1]. Several internal investigations and interlaboratory comparisons in the past have shown significant differences between the lab-specific results of hot storage tests. Figure 2-1 shows the Pseudo-Arrhenius plot of hot storage tests of eight different laboratories (Round Robin Test 2002, BAM). The dust under this investigation was Lycopodium powder (spores). The par-ticipants of this interlaboratory test used different laboratory ovens (size, ventilation) as well as differ-ent sample baskets (shape, mesh size, single- and double-walled). Figure 2-1 shows clearly that this test failed to produce reasonable reproducibility of the TSI between the different laboratories. As possible reasons for the deviations have been identified lab-specific dif-ferences, e.g.: - oven ventilation (enforced, natural convection), - oven size, - sample baskets, - radiation effects, - measuring precision (temperature difference between tests with ignition and no ignition), - minimum sample size. To reduce the differences between the labs it was necessary to ameliorate the testing method and to improve the execution of the method by the lab. From there, the installation of an inner chamber into the laboratory oven was suggested as experimental set-up in EN 15188:2007 to provide more repro-ducible test conditions. The aappropriateness of this set-up has not been verified yet. The current interlaboratory test 2010-2011 focuses on the use of a special mesh wire screen and spe-cial volumes of the sample baskets (cubes) to normalise/harmonise the test conditions in the different labs. In preparation for the interlaboratory test a joint program between Syngenta and BAM has been initiated in 2009. As a result of these investigations a modified set-up ( chapter 3) has been identi-fied to be probably more appropriate than the suggested set-up in DIN EN-15188:2007. Due to the time-consuming test procedure and to optimize the workflow for the laboratories this in-terlaboratory test should be performed stepwise as a multi-level test ( chapter 5.4) on one typical test sample. KW - Interlaboratory test KW - Self-ignition KW - Spontaneous ignition PY - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-282978 SN - 978-3-9815748-4-5 IS - Final Report SP - 1 EP - 113 PB - Bundesanstalt für Materialforschung und -prüfung (BAM) CY - Berlin AN - OPUS4-28297 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -