The Committee of Experts on the Transport of Dangerous Goods and the Globally Harmonized System of Classification and Labelling of Chemicals adapted the new classification for ammonium hydrogendifluoride (CAS: 1341-49-7 Index No. 009-009-00-4) at the sixty-third session of Transport of Dangerous Goods. Sweden proposed the amendment to the classification.
The Sub-Committee of Experts on the Transport of Dangerous Goods (SCETDG) further clarified that
In addition to the harmonised classification skin corrosion 1B – H314, acute toxicity 3 – H 301 will be added to the classification.
For the solid form it is listed as UN 1727 ammonium hydrogendifluoride and classified as Class 8 (corrosive) with no subsidiary hazards.
For the liquid form there is already a 6.1 subsidiary hazard listed under UN 2817.
The 24th edition of the Model Regulations, which will come into force in January 2027, will include the Class 6.1 (toxic) classification as a secondary hazard for UN 1727.
Further details of the classification can be found here.