The European Commission’s (EC) Scientific Committee on Consumer Safety (SCCS) published on May 16, 2023, the 12th revision of The SCCS Notes of Guidance for the Testing of Cosmetic Ingredients and Their Safety Evaluation. The guidance contains information on the different aspects of testing and safety evaluation of cosmetic substances in Europe. The emphasis of the guidance is on cosmetic ingredients, but it notes that “some guidance is also indirectly given for the safety assessment of finished products.” The guidance includes a section on “special consideration for certain cosmetic ingredients” that addresses specific ingredients, including nanomaterials. It addresses:

• Definition of nanomaterial: Under Article 2 (1) (k) of the Cosmetic Regulation, “nanomaterial” means “an insoluble or bio-persistent and intentionally manufactured material with one or more external dimensions, or an internal structure, on the scale from 1 to 100 nm.” The guidance notes that it is likely that this definition will be aligned with the EC’s June 10, 2022, Recommendation on the definition of nanomaterial. According to the guidance, “[t]he Regulation therefore mainly covers those nanomaterials that are intentionally produced and are insoluble/poorly-soluble or biopersistent (e.g., metals, metal oxides, carbon materials, etc.), and not those that are either completely soluble or degraded and are not persistent in biological systems (e.g., liposomes, oil/water emulsions, etc.).”

• Potential safety issues of nanomaterials: According to the guidance, as a general principle, certain specific attributes should add a further degree of safety concern. SCCS notes that it has published more specific Guidance on Risk Assessment of Nanomaterials (SCCS/1611/19, under revision), which is an update of a previous guidance published in 2012 (SCCS/1484/12), a Memorandum on the Relevance, Adequacy and Quality of the Data Expected in Safety Dossiers on Nanomaterials (SCCS/1524/13), and a checklist for the applicants submitting dossiers on nanomaterials as cosmetic ingredients (SCCS/1588/17). The guidance states: “In general, a number of reviews have concluded that the existing risk assessment paradigm, in use for conventional chemicals, should in principle be also applicable to engineered nanomaterials. However, it has also been pointed out that the current testing methods may need certain adaptations to take account of the special features of nanomaterials.”

• Required information for nanomaterials: The guidance lists aspects that “deserve special attention.” According to the guidance, a full dataset “would be preferable.” The guidance states that at a minimum, in addition to safety data on the core nanomaterial, SCCS would require information/data on each material used for surface modification/coating of the nanomaterial to indicate that it is safe for use in the intended cosmetic product; data on physicochemical properties of the surface-modified/coated nanomaterial to show that they have not significantly changed compared to either the same material when uncoated, or with a different surface modification/coating that has already been assessed safe by SCCS; data on dermal penetration, stability of the surface modification/coating, and (photo)catalytic activity, where relevant; and data on interaction of nanomaterial with cells (cellular uptake).