Lueth P., Frost K., Kurth L., Malow M., Michael-Schulz H., Schmidt M., Schulte P., Uhlig S., Zakel S., 2019, CEQAT-DGHS Interlaboratory Test Programme for Chemical Safety - Need of Test Methods Validation, Chemical Engineering Transactions, 77, 1-6.
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, Hasselbarth (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.