Classification

As part of the classification procedure substances and preparations/mixtures are assessed in regard to their hazardous characteristics and assigned to pre-defined hazard classes.

Information on hazards posed by chemical products (substances and mixtures/preparations) is provided by labelling the product and in the trade and professional context also by the safety data sheet. This information has been harmonised worldwide in the globally harmonised system for the classification and labelling of chemicals (GHS) of the UNO. The EU transposed this into its law in the CLP Regulation (Regulation (EC) No 1272/2008, Classification, Labelling, Packaging). Switzerland has extensively harmonised its law with the CLP provisions in order that technical barriers to trade do not occur.

In the internet document “Swiss CLP: Guide to Classification, Labelling and Packaging of Substances and Preparations in Switzerland” the implementation in Switzerland is explained in detail and deals thoroughly with the provisions for the classification of chemicals by taking into consideration available resources for the CLP Regulation and possible data sources.

Swiss-CLP: Wegleitung zum Einstufen, Kennzeichnen und Verpacken von Stoffen und Zubereitungen in der Schweiz (PDF, 1 MB, 26.10.2017)(available in German, French and Italian)

Classification in three steps

Collect the available information. This particularly includes data that are available from ECHA (REACH dossiers, Classification and Labelling, C&L-Inventory) but also other publicly available databases and information.
Information on chemicals (ECHA)
Assess the adequacy and reliability of the data
Compare the data with the classification criteria / Decision on the classification

Methods for the classification according to GHS

Test data or experience in humans
Test results and other information need to be collected and the weight of evidence evaluated by experts. With the relevant data the substances and mixtures are classified based on the new GHS classification criteria.
Conclusion by analogy
The classification of a chemical product is derived from the classification of another chemical product having a similar composition, for which adequate information exists. A comparable procedure, known as the “Trustee-Expert Model” and the “AISE Model”, has been practiced hitherto and used principally in the washing and cleaning agent industry.
Conventional method (calculation)
The classification of a mixture can be calculated as before, based on the concentration of the hazardous ingredient. New or changed concentration limit values shall be taken into account. For day-to-day practice the use of one of the numerous commercially available classification software programs is recommended.
Annex VI of the CLP Ordinance
The classification of certain substances is specified in Annex VI of the CLP Ordinance and must be observed. Warning! For specific substances the classification in Annex VI is only available for selected hazard classes and not for all. It may also be the case that these classes are to be updated.
If no harmonised classification exists in Annex VI of the CLP Ordinance then the manufacturers themselves need to decide on the classification. This is called an autonomous or self-classification.

ATP – Adjustments in the light of technical progress

The CLP Ordinance is regularly adapted in the light of technical and scientific progress (ATP - Adaptation to Technical Progress). This often has repercussions on the classification of certain substances. Information on the ATPs can be found under ATP in the CLP Regulation.