The United Nations has released the 11th Revised Edition of the Globally Harmonized System of Classification and Labelling of Chemicals (GHS Rev. 11, 2025), incorporating new rules for classifying climate-related chemical hazards, non-animal test methods for skin sensitisation, and clearer labelling requirements. Endorsed in December 2024 and published in September 2025, this revision has direct implications for chemical manufacturers, downstream users, transporters, and regulatory professionals globally.
New Climate Hazard Classifications
For the first time, the GHS introduces classification criteria for chemicals hazardous to the atmospheric system. This includes substances and mixtures contributing to global warming, with dedicated guidance in Chapter 4.2. These changes align with the rising regulatory focus on climate impacts and support implementation of the 2030 UN Sustainable Development Goals.
Industry stakeholders handling fluorinated gases or high-GWP substances must now evaluate and classify based on global warming potential—a measure of a chemical’s heat-trapping effect compared to CO₂.
Advances in Animal-Free Skin Sensitisation Testing
GHS Rev. 11 adds robust guidance in Chapter 3.4 for classifying skin sensitisers using non-animal methods, in line with evolving scientific standards and animal welfare expectations. This includes defined approaches using in vitro assays, human data, and computational models.
The updated framework supports regulators and industry in meeting both ethical and regulatory objectives—particularly under regional frameworks like REACH and the OECD Test Guidelines Programme.
Clarified Aerosol and Pressure Classification
Chapter 2.3 has been amended to better distinguish between aerosols and chemicals under pressure, improving the accuracy of hazard communication. This is especially relevant for companies dealing with aerosolised formulations and pressurised gases in transport or workplace settings.
Additionally, Annex 11 now includes guidance on identifying simple asphyxiants—gases that displace oxygen but are otherwise non-toxic, a notable inclusion for occupational safety planning.
Streamlined Precautionary Statements
To ease implementation and improve label usability, precautionary statements have been further rationalised. This includes enhanced consistency and comprehensibility across languages and use sectors (e.g. workplace, consumer, transport), as outlined in Annex 3.
Labelling practitioners should review these changes to ensure compliance, especially where automation and multilingual output are involved.
