On June 26, 2023, the European Commission’s (EC) Scientific Committee on Consumer Safety (SCCS) published the second revision of its Guidance on the Safety Assessment of Nanomaterials in Cosmetics. The Guidance covers the main elements of safety assessment, i.e., general considerations (Section 2), material characterization (Section 3), exposure assessment (Section 4), hazard identification and dose-response characterization (Section 5), and risk assessment (Section 6). SCCS states that the main changes include:

• New sections on solubility and dissolution rate, solubility in non-aqueous media, evidence for the absence of nanoparticles, dispersion, aspect ratio, uptake into blood cells, reproductive toxicity, and endocrine disruption;

• The introduction of the 2022 EC recommendation for a definition of nanomaterials;

• The introduction of key aspects triggering safety concerns over a nanomaterial based on SCCS/1618/2020;

• Updates based on literature that has been published since the last update;

• Revisions to the section on read-across and grouping; and

• The inclusion of text explaining when historical/existing data can be used.

SCCS notes that the Guidance may be subject to future changes “based on the evolution of science in the field of safety assessment of nanomaterials.”