11th revised edition of GHS published: key developments for the chemical industry

On 12 September 2025, the United Nations Economic Commission for Europe (UNECE) published the eleventh revised edition of the Globally Harmonised System of Classification and Labelling of Chemicals (GHS), available in English, French and Spanish. This new version introduces significant changes with direct implications for the chemical industry, particularly with regard to environmental classification, labelling and hazard communication.

Main changes in Revision 11

• Global Warming Potential (GWP): this concept is incorporated as a new classification criterion within the category ‘Hazardous to the atmospheric system’, allowing substances and mixtures that contribute to global warming to be specifically identified and communicated. This new feature introduces differentiated warning phrases and hazard codes (H421), reinforcing the alignment of the GHS with international commitments on climate change and facilitating environmental risk management.

• Aerosols and pressurised chemicals: it is clarified that both are classified independently, updating the tables and eliminating overlaps with other categories such as flammable gases or liquids. In the new revision, it is specified that aerosols are no longer included in the sections relating to pressurised chemicals, flammable gases, pressurised gases, flammable liquids or flammable solids, although they may belong to other hazard categories depending on their content. On the other hand, pressurised chemicals are no longer included in the sections on aerosols, flammable or pressurised gases, and flammable liquids or solids, but may be classified in other hazard categories if appropriate. In addition, specific criteria and tests are incorporated under aerosol standards, improving the accuracy of their assessment and classification.
• Skin and respiratory sensitisation: the classification guidelines have been expanded to include specific tests under aerosol standards, improving the accuracy of their assessment and classification.
• Simple asphyxiants: Annex 11 adds a section with specific guidance for oxygen-displacing gases such as nitrogen, carbon dioxide, and methane. Suggested phrases for labels and SDSs are included, such as ‘May displace oxygen and be deadly’ or ‘Store in a well-ventilated place.’ It is important to note that when a substance or mixture already has an acute inhalation toxicity classification, it is not necessary to additionally label it as a simple asphyxiant.
• Labelling and precautionary statements:several P statements have been simplified and new precautionary statements have been added for the acute toxicity category, including P322 and P323, which refer to the specific treatment required.
• Update of label examples: the possibility of using the UN Model Regulation pictogram on combined labels is removed and the black background frame around the product name is removed.

Relevance for businesses

The changes in Revision 11 directly affect manufacturers, distributors and users of chemical products, especially those who work with industrial gases, aerosols or substances with an impact on the climate. Companies must review their classification processes, labels and safety data sheets to ensure compliance with the new criteria.

At Siam, we keep our Chemeter software continuously updated to ensure compliance with current chemical safety regulations.

This includes both countries that have their own regulations based on the Globally Harmonised System (GHS) —and which will incorporate future updates into their national legislation— and those that do not yet have specific regulations, allowing them to directly prepare Safety Data Sheets (SDS) in accordance with the latest version of the GHS.

For further information, we recommend visiting the official source of the United Nations Economic Commission for Europe.