All substances which are placed on the EU market must be classified by manufacturers, importers or downstream users of chemical substances or mixtures according to Article 4.1 CLP. This obligation applies regardless of the tonnage manufactured, imported or placed on the market.

Besides the obligation to classify under the CLP Regulation, manufacturers and importers must also classify all substances subject to registration and notification obligations under the REACH Regulation (Articles 6, 7, 9, 17 and 18 REACH).

There are two types of classification:

  • Harmonised classification

This type of classification concerns substances for which a classification has been decided upon at the European level. When a harmonised classification and labelling exist, companies must apply this classification. Harmonised classifications can be found in the tables of Annex VI CLP. A harmonised classification only applies to substances and not to mixtures.

  • Self-classification

This type of classification is required when substances do not have a harmonised classification or where a harmonised classification only covers certain hazard classes. The self-classification has to be done by:

  • Manufacturers of substances;
  • Importers of substances or mixtures;
  • Producers or importers of explosive articles or articles for which REACH provides a registration or notification duty;
  • Downstream users, including formulators.

Before undertaking a self-classification, companies need to check if the substance is already classified under the harmonised classification and labelling system.

  • Step 1: Gather all available information that can help to determine the classification of substances;
  • Step 2: Check the information to ensure it is adequate and reliable;
  • Step 3: Evaluate available information against classification criteria. First, companies have to check if the information collected reveals a hazardous property and then, check if the information is directly comparable to respective hazard criteria;
  • Step 4: Decide on a appropriate classification. If the evaluation of the hazard information shows that the substance meets the criteria to be classified for a particular hazard, then the company must assign the respective classification (hazard class and category) and the appropriate labelling elements for the label and/or the safety data sheet.

For mixtures, the same hazards classification procedure applies as for substances in the first step.  Similarly to the way substances are classified, available data on the mixture as a whole should primarily be used to determine the classification (except for the CMR, biodegradation and bioaccumulation properties) where applicable. If this cannot be done, other approaches to the mixture classification may be applied.

It is important to choose the most appropriate method to determine the classification of a mixture for each hazard class, differentiation or category. The method will depend on whether the mixture is being assessed for physical, health or environmental hazards and on the type and quality of information that is available. Depending on the information you have and on the hazard under consideration, you should classify using the approaches provided below in the following sequence:

  • Classification derived using data on the mixture itself, by applying the substance criteria of Annex I to CLP;
  • For health and environmental hazards only: classification based on the application of the so-called bridging principles, which make use of data on similar mixtures which have already been tested and information on individual hazardous substances which are ingredients of the mixture;
  • For health and environmental hazards only: classification based on a calculation or on concentration limits in case substances which are classified for the particular hazard are present in the mixture.

Manufacturers, importers and downstream users need to follow new scientific or technical developments and estimate whether a re-evaluation of the classification of the substance or mixture they place on the market should be done.

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