Peter Lüth’s research while affiliated with Federal Institute For Materials Research and Testing and other places

Laboratory test results are of vital importance for correctly classifying and labelling chemicals as “hazardous” as defined in the UN Globally Harmonized System (GHS)/EC CLP Regulation or as “dangerous goods” as defined in the UN Recommendations on the Transport of Dangerous Goods. Interlaboratory tests play a decisive role in assessing the reliability of laboratory test results. Interlaboratory tests performed over the last 10 years have examined different laboratory test methods. After analysing the results of these interlaboratory tests, the following conclusions can be drawn: 1 There is a need for improvement and validation for all laboratory test methods examined. 2 To avoid any discrepancy concerning the classification and labelling of chemicals, the use of validated laboratory test methods should be state of the art, with the results accompanied by the measurement uncertainty and (if applicable) the probability of incorrect classification. This paper addresses the probability of correct/incorrect classification (for example, as dangerous goods) on the basis of the measurement deviation obtained from interlaboratory tests performed by the Centre for quality assurance for testing of dangerous goods and hazardous substances (CEQAT-DGHS) to validate laboratory test methods. This paper outlines typical results (e.g. so-called “Shark profiles” – the probability of incorrect classification as a function of the true value estimated from interlaboratory test data) as well as general conclusions and steps to be taken to guarantee that laboratory test results are fit for purpose and of high quality.

Various standardised test methods are used by laboratories to determine the hazardous properties and safety characteristics of chemical substances and mixtures, e.g. test methods published by the European Union (2008) and by the United Nations (2015). The test results are the basis (amongst others) for the correct classification and labelling of chemicals as hazardous according to GHS/CLP or as dangerous goods according to Transport Regulations. The REACH Regulation obliges all manufacturers and importers of chemicals to identify and manage risks associated with the substances they manufacture and market. Via the eChemPortal (www.echemportal.org) many data from the REACH registration dossiers are available. However, the quality and correctness of the information remains in the responsibility of the data submitter. Unfortunately, the quality of information on physicochemical properties is not always adequate, so the quality and adequacy of the data submitted shall be improved. This paper focusses on the quality of test results obtained by laboratories and the validation of the test methods used e.g. for classification of dangerous goods and indicates recent developments as well as steps to be taken for further improvement. In particular, the importance of interlaboratory tests and the need to validate test methods are presented in this publication. Interlaboratory tests play a decisive role in assessing the reliability of laboratory test results. Participation in interlaboratory tests is not only a crucial element of the quality assurance of laboratories; as such it is explicitly recommended in ISO/IEC 17025, ISO (2017). In addition, interlaboratory tests are also used to improve and validate test methods and can be used for the determination of the measurement uncertainty, Hässelbarth (2004), ISO (2004). This paper specially addresses interlaboratory tests for the validation of test methods performed by CEQAT-DGHS (Centre for quality assurance for testing of dangerous goods and hazardous substances, www.ceqat-dghs.bam.de) and outlines typical results and general conclusions and steps to be taken to guarantee that laboratory test results are fit for the purpose and of high quality.

The test methods UN Test L.2 / EN ISO 9038:2013 DIN EN 15188:2007 are applied to characterize the sustained combustibility of liquids i.e. the behaviour of a material under specified test conditions, whereby its vapour can be ignited by an ignition source and sufficient flammable vapour is produced to continue burning for at least 15 s after the source of ignition has been removed. The aims of this interlaboratory test (IT) are the verification and/or the improvement (if necessary) of the verification data (reference material) in Annex B of EN ISO 9038:2013, the assessment of influencing (disturbing) factors (laboratory specific factors, which possibly may have an influence on the test result) and the assessment of the performance of the participating laboratories. It could be demonstrated that the reference materials n-Dodecane, n-Decane and n-Undecane as mentioned in the standard are suitable and the verification shall continue to be valid. Sustained combustibility tests are…

For the classification, safe handling and use of the chemicals, special standardized testing procedures have been developed and are used worldwide. Safety experts must be able to fully rely on the precise execution of the respective laboratory tests and assessments. In this context, interlaboratory tests 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 the results of the interlaboratory test 2015-2016, which was performed on the test method DIN EN 15188:2007 “Determination of the spontaneous ignition behaviour of dust accumulations”. It was organized by BAM in the frame of the co-operation project CEQAT-DGHS Centre for Quality Assurance for Testing of Dangerous Goods and Hazardous Substances. The test method DIN EN 15188:2007 is applied to characterize the self-ignition behaviour of combustible dusts. The experimental basis for describing the…

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…

For the classification of chemicals, special standardized test procedures have been developed and are used world-wide. Safe handling and use of these chemicals depend on the correct classification which therefore must be based on the precise and correct execution of the tests and their evaluation. 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 2009/2010 on the test methods UN O.2 “Test for oxidizing liquids” [1] / EC A.21 “Oxidizing Properties (Liquids)” [2] which was organized by the Center for Quality Assurance for Testing of Dangerous Goods and Hazardous Substances. The test methods UN O.2 and EC A.21 are applied to characterize the oxidizing properties of liquid chemical substances or mixtures.

The classification of solid oxidizers according to the GHS (Globally Harmonized System of Classifica-tion and Labelling of Chemicals) and according to regulations on the transport of dangerous goods (based on the UN Recommendations/Model Regulations and implemented in all carrier domains as transport by road, railway, sea, air) is performed on the basis of the results of the UN test O.1 (―Test for oxidizing solids‖ described in chapter 34.4.1 in the Recommendations on the Transport of Danger-ous Goods, Manual of Tests and Criteria, Fifth revised edition, United Nations, New York and Geneva, 2009). This test was introduced into the UN Test Manual in 1995 as a replacement for a similar test from 1986. Even though the O.1 test is much better than the previous one there are still many prob-lems with this test. For this reason the IGUS-EOS working group (international group of experts on the explosion risks of unstable substances – working group: energetic and oxidizing substances)…