Original source
Scientific Advice on the safety of Thiomersal (CAS No. 54-64-8, EC No. 200-210-4) and Phenylmercuric salts as preservatives in cosmetic products
- Official date
- 2026-02-10
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The SCCS scientific advice (SCCS/1686/25), adopted on 2 February 2026 and published on 10 February 2026, addresses the safety of Thiomersal and Phenylmercuric salts as preservatives in cosmetic eye products under Regulation (EC) No 1223/2009. The SCCS concludes that the use of these substances at current permitted concentrations is not safe, citing a Margin of Safety below 100 based on renal toxicity and unresolved genotoxicity concerns. The risk is aggravated by additional exposure to mercuric compounds from non-cosmetic sources. The European Commission may consider regulatory action based on this advice.
The SCCS has concluded that the use of Thiomersal and Phenylmercuric salts as preservatives in cosmetic eye products is not safe at currently permitted concentrations. This is based on a Margin of Safety less than 100 for renal toxicity and unresolved genotoxicity concerns. The risk is further increased by additional exposure to mercuric compounds from other sources. This may lead to regulatory restrictions on these ingredients in the EU.
Official text
English translation — the official-language text prevails
In light of technical and scientific progress and SCCS’ expert judgement and taking under consideration in particular the various health concerns, the SCCS is requested: (1) to identify and justify whether there are specific concerns regarding the current use of ‘Thiomersal’ and ‘Phenylmercuric salts’ as preservatives in cosmetic eye products; Considering that the Margin of Safety based on renal toxicity as the most sensitive endpoint is less than 100, and that genotoxicity evidence is unresolved, the use of ‘Thiomersal’ and ‘Phenylmercuric salts’ as preservatives in cosmetic eye products is not considered safe at the concentration levels currently permitted in cosmetic products. (2) to highlight if there is a potential risk for human health from the current use of ‘Thiomersal’ and ‘Phenylmercuric salts’ as preservatives in cosmetic eye products; The potential risk for human health from use in cosmetic eye products is aggravated by additional exposure to mercuric compounds from sources other than cosmetics.