On 22 January 2025, the SCCS (Scientific Committee on Consumer Safety) accepted mandates from the European Commission to assess the safety of three cosmetic ingredients: Thimerosal and Phenylmercury salts (preservatives) on the one hand, and Cannabidiol on the other.
Thimerosal and Phenylmercury salts
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. In particular, such mercury containing compounds are allowed only in eye products and with a maximum concentration that does not exceed 0.007% (of mercury), when used alone or in combination (i.e., if mixed with other mercurial compounds that are currently authorised, the maximum concentration of mercury remains fixed at 0.007%). In addition, cosmetic products that contain such compounds must include in their labelling the warnings “Contains Thiomersal” or “Contains Phenylmercuric compounds”.
Apart from “Thiomersal” that is a single substance, “Phenylmercuric salts” cover all salts composed of the phenylmercury cation (C6H5Hg+) paired with an anion, such as acetate, benzoate, borate, bromide, chloride, oleate, etc.
Mercury and its compounds are toxic, and exposure can lead to various adverse health effects, including but not limited to neurological and kidney damage, skin …
