On March 12, 2024, the Health and Safety Executive (HSE) updated the GB Mandatory Classification List (MCL) by adding 25 new chemical substances, as mandated by Article 37 of the GB Classification, Labelling and Packaging (CLP) Regulation. This update impacts substances identified as cosmetic ingredients with proposed Carcinogen, Mutagen, or Reprotoxic (CMR) classifications under Article 15 of the UK Cosmetics Regulation (UKCR). Notably, 2-ethylhexanoic acid and its zinc salt, along with Dimethyltolylamine, are among those facing potential bans and additions to the UK Cosmetics Regulation’s Annex II. These changes will come into effect on September 2, 2025.