On September 12, 2025, the 11th revised edition of the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) was published on the UNECE website. Currently available in English, French, and Spanish.
Compared to the 10th revised edition of UN GHS, key revisions include:
1. Addition of the concept 'Global Warming Potential (GWP)'
Global Warming Potential refers to a metric that compares the ability of a substance or mixture to trap heat in the atmosphere relative to a reference gas (typically carbon dioxide). The formal definition of GWP is the cumulative radiative forcing effect over a specified time horizon, per unit mass of gas emitted, relative to carbon dioxide (as the reference gas), including both direct and indirect effects.
2. Clarification of independent classification for aerosols and pressurized chemicals
In the chapter on 'Aerosols and Pressurized Chemicals,' it is clarified that aerosols no longer fall under Sections 2.3.2 (Pressurized Chemicals), Chapter 2.2 (Flammable Gases), Chapter 2.5 (Pressurized Gases), Chapter 2.6 (Flammable Liquids), or Chapter 2.7 (Flammable Solids). However, aerosols may still belong to other hazard categories due to their contents. Similarly, pressurized chemicals no longer fall under Sections 2.3.1 (Aerosols), Chapter 2.2 (Flammable Gases), Chapter 2.5 (Pressurized Gases), Chapter 2.6 (Flammable Liquids), or Chapter 2.7 (Flammable Solids). However, pressurized chemicals may still belong to other hazard categories due to their contents.
3. Clarification of aerosol classification criteria
Supplement and modification of Table 2.3.1: Partial test content under aerosol standards.
4. Revision of notes in 'Desensitized Explosives'
Modification or deletion of notes or footnotes related to digestible cellulose in the chapter on 'Desensitized Explosives.'
5. Revision of classification guidance in 'Respiratory or Skin Sensitization'
For substances and mixtures undergoing skin sensitization classification, information from human predictive patch tests, epidemiological studies, case studies, case reports or medical histories, diagnostic patch tests and medical examination reports, as well as poison control center data, may be used.
6. Addition of 'Hazardous by contributing to global warming'
The category of 'Hazardous to the ozone layer' in environmental hazards has been renamed to 'Hazardous to the atmospheric system,' covering substances and mixtures that are harmful to the atmospheric system due to their ozone depletion and/or global warming potential. This chapter introduces 'Hazardous by contributing to global warming,' providing classification criteria, label elements, and classification determination logic. Companies related to greenhouse gases need to pay special attention.
7. Updates to the precautionary statements for acute toxicity (P-statements)
Some precautionary statements corresponding to the 'Acute toxicity' hazard category have been adjusted. Among them, P322 and P323 are new precautionary statements.
8. Updated label examples
1) In Annex 7, examples of label elements, the description stating 'Inner packaging labels may use the flammable liquid pictogram specified in the United Nations Model Regulations instead of the Globally Harmonized System pictogram' has been removed from the combined label examples.
2) The new label examples have all removed the black background frame for the product name.
9. Addition of simple asphyxiants
New content on 'simple asphyxiants' has been added to Annex 11 (Guidance on other hazards not leading to classification). An asphyxiant is a gas or vapor that can cause a person to lose consciousness or even die due to oxygen deprivation. Asphyxiants include chemical asphyxiants and simple asphyxiants. Chemical asphyxiants refer to substances that prevent the blood from absorbing oxygen or disrupt the normal delivery of oxygen from the blood to tissues or cells, leading to asphyxiation. Specific toxic health effects related to chemical asphyxiants include acute toxicity, specific target organ toxicity—single exposure, and specific target organ toxicity—repeated exposure. Simple asphyxiants are gases or vapors that displace oxygen, thereby causing hypoxia in individuals exposed to a substance or mixture, potentially leading to unconsciousness or death. When the concentration of a simple asphyxiant is too high, it reduces the oxygen level in the air to a dangerous level, posing a health risk. If a substance or mixture has already been classified as having acute toxicity (inhalation), it does not need to be labeled as a simple asphyxiant. Common simple asphyxiants include carbon dioxide, hydrogen, nitrogen, helium, neon, argon, krypton, xenon, ethane, ethylene, acetylene, methane, propane, propylene, aliphatic alkanes, and chlorofluorocarbons.
To indicate the hazard of simple asphyxiant gases, the competent authority may require the use of the following phrases on labels, SDS, and/or operating instructions, or allow manufacturers or suppliers to choose at their own discretion:
- May displace oxygen and be fatal.
- In addition, 'Danger' and/or 'Store in well-ventilated place' may also be used.
The UN GHS is revised every two years, and the release of the new 2025 version involves updates to multiple hazard classifications. Enterprises with products related to the above hazards should take note. In the future, amendments to GHS regulations in various countries may adopt the content of the latest revised edition. Specific revisions and original text link: https://unece.org/transport/dangerous-goods/ghs-rev11-2025
