Draft of UN GHS Rev.12 Released for Public Review: Major Updates to Physical Hazards and Precautionary Statements!

The 49th session of the United Nations Subcommittee of Experts on the Globally Harmonized System of Classification and Labelling of Chemicals (SCEGHS) was held in Geneva in July 2026. Annex I of the session report documents the draft amendments to the 11th Revised Version of the UN GHS (UN GHS Rev.11), which are expected to be incorporated into the 12th Revised Version (UN GHS Rev.12). The proposed revisions cover multiple hazard classes, including flammable liquids, flammable aerosols, and germ cell mutagenicity. The following highlights some noteworthy aspects of the draft.

Classification Criteria for Physical Hazards

1. The scope of explosives has been defined, distinguishing self-reactive substances and mixtures, organic peroxides, and desensitized explosives from explosives for manufacturing purposes. Substances classified as explosives may also be classified as pyrophoric liquids or pyrophoric solids.
2. The boundaries between certain physical hazard classifications have been clarified, specifying that certain physical hazards should not be classified into other categories. For instance, explosives, aerosols, chemicals under pressure, self-reactive substances and mixtures, organic peroxides, and desensitized explosives should not be classified as flammable gases or gases under pressure. The draft will add corresponding definitions and scopes for these physical hazards.
3. Several combinations of physical hazards have been added. Examples include new combinations of self-reactive substances and mixtures with pyrophoric liquids or solids, explosives with pyrophoric liquids or solids, and organic peroxides with pyrophoric liquids or solids.
4. In the section on desensitized explosives, a new requirement states that to be classified as a desensitized explosive, the desensitizing agent used to suppress the explosive properties must be thermally stable and must not possess pyrophoric, self-heating, or oxidizing properties. The phrase "for storage, supply, and use" has also been added.

In the future, if companies have products involving these hazard classifications, they may need to adjust label elements such as pictograms accordingly.

Revisions to Precautionary Statements

1. The flammable liquids hazard category has been removed from precautionary statements P303, P361, and P353, and the deleted content will be replaced by the combined statement P302+P352. The informal working group will continue to address this issue.
2. For substances and mixtures which, in contact with water, emit flammable gases (Hazard Categories 1 and 2), the entries for P302+P339 and P302+P335+P339 in the "Response" column are replaced with:
• P302+P343 IF ON SKIN: Immediately remove excess chemical by blotting and immerse in cool water (liquids only). Manufacturers or suppliers shall specify the type of absorbent material to be used for blotting (e.g., absorbent kits, cotton cloth, paper towels, etc.) in the safety data sheet or supplementary safety information provided to consumers.
• P302+P335+P339 IF ON SKIN: Immediately brush off loose particles and immerse in cool water (solids only).
3. For pyrophoric solids (Category 1), the precautionary statement P302+P335+P334 is changed to: IF ON SKIN: Immediately brush off loose particles and immerse in cool water or wrap in wet bandages.
4. New precautionary statements have been added, or conditions of use have been supplemented, as shown in the table below:

Additionally, topics such as non-animal methods for health and environmental hazard classification, classification criteria for germ cell mutagenicity, potential hazards, simple asphyxiants, acute toxicity classification, and the definition of "articles" will be further considered in the future.