ECHA - Guidance of the application of CLP criteria [November 2012]

Guidance on the Application of the CLP Criteria Version 3.0 - November 2012After the available information has been assembled, a systematic evaluation of thisinformation is necessary in order to derive a classification. The information must be comparedwith the criteria for classification for each hazard class or differentiation within the hazardclass. Differentiation is a distinction depending on the route of exposure or the nature of theeffects. A decision should be made as to whether the substance meets the criteria forclassification. When this is the case; the classifier should assign one or more hazardcategories for each relevant hazard class or differentiation. The substance is then assigned theappropriate hazard communication elements.In some cases the classification decision may be straightforward, requiring only an evaluationof whether the substance gave a positive or negative result in a specific test that can bedirectly compared with the classification criteria. In other cases, scientific judgements must bemade (e.g. on dose/response relationships, equivocal results and non-standardised tests).Expert judgement may therefore be needed to decide whether the results of a particular testmeet the criteria laid down in Annex I.1.1.7.2 Influence of impurities, additives or individual constituents on theclassification of a substanceSubstances may contain impurities, additives, or other constituents while still meeting thesubstance definition in CLP. This applies to both mono-constituent, multi-constituent (e.g.reaction masses) and UVCB substances. The classification of such impurities, additives orindividual constituents may influence the classification of the substance, in addition to theother hazardous properties.1.1.8 Updating of hazard classificationsUpdating of classifications may be necessary, if new information is obtained or if the criteriain CLP are amended. When manufacturers, importers or downstream users become aware ofnew information or an amendment to CLP or when a change is introduced in a mixture, theymust reconsider the classification of the substance or mixture (but note that a downstreamuser can rely on the classification from his supplier, provided he shares the new informationwith that supplier to allow him to meet the requirements).1.1.9 The interface between hazard classification and hazard communicationIn addition to SDS, CLP provides an integrated system of hazard communication elements(hazard pictograms, signal words, hazard statements and precautionary statements) on thelabel. Provision of this information to the end user is obligatory, irrespective of conditions ofuse and risk. While the Chemical Safety Assessment (CSA) on a particular substanceperformed for the purpose of REACH may indicate "safe use", a situation resulting inunforeseen exposure may occur, such as in an accident. In such a situation, workers, managersand emergency personnel will need information on the hazard profile of the substance, whichwill be provided by the label and the SDS. These sources of information will also provideuseful information to the worker on the safe handling of the chemical.It is recognised that the hazard communication needs of the various end users may differ.Consumers are primarily dependent on the label of a substance or a mixture as a source ofhazard and precautionary information, while the requirement for provision of an SDS isprimarily applicable to professional users. Thus, the label facilitates communication of keyhazard information and additional safety advice (precautionary statements) to consumers of asubstance or a mixture.38