
In January 2025, the SCCS accepted the European Commission’s mandate to assess the safety of Thiomersal and Phenylmercury salts as preservatives. The Scientific Committee on Consumer Safety has just published the final Opinion of its Scientific Advice.
Background
Mercury and its compounds have been prohibited from use in cosmetics products already in the Cosmetics Directive 76/768/EEC and this prohibition is still applicable via entry 221 of Annex II to the Cosmetics Regulation (EC) No.1223/2009.
Nevertheless, entries 16 and 17 of Annex V (preservatives) to the Cosmetics Regulation 1223/2009 allow the use of “Thiomersal” and “Phenylmercuric salts (including borate)”, respectively, in cosmetic products under specific conditions.
Given the severe health risks associated with mercury, the Commission requested the SCCS to provide a scientific advice on the safety of preservatives that contain mercury (and its compounds).
The SCCS adopted its preliminary Advice in October 2025.
For an exhaustive background information, see the articles
• Thimerosal, Phenylmercuric salts, Cannabidiol: requests for SCCS Opinion, CosmeticOBS, 3 February 2025
• Thiomersal, Phenylmercuric salts: preliminary Opinion of the SCCS, CosmeticOBS, 20 November 2025
This Scientific Advice has been subject to a commenting period of min eight weeks after its initial publication (from 19 November 2025 to 21 January 2026, due to holiday period).
No comment was received during this period.
The conclusions of this Advice remain but have been slightly reworded.
The SCCS’s Advice
In light …












