Is Thiomersal safe in cosmetic eye products?
The Scientific Committee on Consumer Safety (SCCS) concluded that Thiomersal and phenylmercuric salts are not safe for use in cosmetic eye products at current EU permitted levels due to a Margin of Safety below 100 and unresolved renal toxicity and genotoxicity concerns.
What is the SCCS assessment on Thiomersal and phenylmercuric salts?
The assessment (SCCS/1686/25) was requested by the European Commission following updated scientific data and ongoing concerns regarding mercury-based compounds in cosmetics.
Are Thiomersal and phenylmercuric salts allowed in cosmetics?
Although mercury and its derivatives are generally prohibited under EU cosmetics legislation, Thiomersal and phenylmercuric salts remain permitted as preservatives in eye products at concentrations up to 0.007% (expressed as mercury).
When was the SCCS opinion published and finalised?
A preliminary opinion was published on 19 November 2025 and opened for public consultation until 21 January 2026. The Scientific Committee on Consumer Safety adopted its final opinion (CAS No. 54-64-8, EC No. 200-210-4) on 2 February 2026.
Why are Thiomersal and phenylmercuric salts considered unsafe?
The SCCS identified a Margin of Safety below the acceptable threshold of 100, indicating potential risk to consumers. Kidney toxicity was identified as the most sensitive toxicological endpoint in the assessment.
Does mercury exposure increase overall risk?
Yes. The SCCS highlighted that cumulative exposure from food, environmental sources, and other non-cosmetic routes may increase overall mercury exposure, supporting a precautionary approach to risk assessment.
What regulation applies to Thiomersal in cosmetics?
The assessment was conducted under the Cosmetics Regulation (EC) No. 1223/2009 and may lead to future amendments to Annex V, potentially restricting or prohibiting these substances in cosmetic eye products.
What regulatory follow-up actions are expected for Thiomersal in EU cosmetics?
This opinion is relevant for the cosmetics industry as it is expected to trigger regulatory follow-up by the European Commission. It may lead to amendments to Annex V of the Cosmetics Regulation (EC) No. 1223/2009, potentially affecting the permitted use of Thiomersal and phenylmercuric salts in cosmetic eye products. Such a revision could restrict or fully prohibit their use in these products.
What did the SCCS conclude about Thiomersal?
The Scientific Committee on Consumer Safety concluded that Thiomersal and phenylmercuric salts are not safe for use in cosmetic eye products at current EU permitted levels due to a Margin of Safety below 100 and unresolved toxicity concerns.
