On 20 May 2026, ECHA (the European Chemicals Agency) announced the publication of the conclusions of the assessment of Butanone (INCI: MEK), carried out by Sweden as part of the Community Rolling Action Plan (CoRAP). This could result in the substance being classified as toxic to reproduction.
Butanone (CAS No.78-93-3, EC No.201-159-0, INCI: MEK) is an ingredient listed in COSING, with the following functions: Solvent, Perfuming.
The substance is not currently regulated by the European Cosmetics Regulation 1223/2009.
It is listed in Annex VI/606-002-00-3 of the European CLP Regulation 1272/2008, with the following classifications:
• Flam. Liq. 2, H225 - Highly flammable liquid and vapour.
• Eye Irrit. 2, H319 - Causes serious eye irritation.
• STOT SE 3, H336 - May cause drowsiness or dizziness.
The CoRAP evaluation
Butanone has been included in the CoRAP for several reasons of concern:
• Reproductive toxicity
• Endocrine disruption (human health)
• Wide dispersive use
• Consumer use
• Exposure of environment
• Exposure of workers
• High RCR
• High (estimated) tonnages
Sweden, the Evaluating Member State, finalised the dossier on 23 March 2026, with the following conclusions:
• developmental toxicity (neurotoxicity): concern confirmed,
• reproductive toxicity (fertility): inconclusive,
• endocrine disruption (human health): concern removed (clarification of hazard).
Sweden therefore recommends that the substance be classified as a reproductive toxicant.
Its report also states that, as the substance is widely used in the workplace and poses a high risk of exposure through inhalation …
