Nanomaterial: Definition and Use in Cosmetic Products

What Is a Nanomaterial?

A nanomaterial is a material with at least one external dimension, or an internal structure, in the nanoscale range. Nanomaterials can exhibit properties that differ from their conventional forms because of their small size, increased surface area and other physical and chemical characteristics.

In cosmetics, nanomaterials may be used to influence product performance, stability or sensory properties.

Nanomaterials in Cosmetics

Nanomaterials are increasingly used in cosmetic formulations because their specific properties can provide formulation benefits. Depending on the material and application, they may be used to:

• Improve the performance of cosmetic ingredients
• Increase the stability of certain ingredients
• Improve the texture, colour or other aesthetic properties of a product
• Deliver or carry other substances within a formulation

Examples of materials that may fall within the scope of the EU Cosmetics Regulation include certain metals, metal oxides and carbon-based materials.

Definition Under the EU Cosmetics Regulation

Regulation (EC) No 1223/2009 defines a nanomaterial as an insoluble or biopersistent and intentionally manufactured material with one or more external dimensions, or an internal structure, on the scale of 1–100 nm.

The regulatory assessment focuses particularly on intentionally manufactured nanomaterials that are insoluble or poorly soluble or biopersistent. Materials such as completely soluble substances or materials that readily degrade and are not persistent in biological systems may therefore be treated differently.

Safety Assessment of Nanomaterials

Nanomaterials require particular attention during cosmetic safety assessment because their physicochemical properties and biological behaviour can differ from those of the corresponding conventional material.

Factors that may be relevant to the safety assessment include:

• Particle size and size distribution
• Solubility and dissolution behaviour
• Chemical composition
• Particle shape and morphology
• Surface reactivity and surface modifications
• Potential systemic exposure
• Persistence or accumulation
• Intended route of exposure, including inhalation

Testing may also require specific consideration of particle aggregation, dispersion and the appropriate dose metrics, such as particle number or surface area, rather than relying solely on weight or volume concentration.

Nanomaterials and Cosmetic Regulation

The use of nanomaterials in cosmetic products is specifically addressed by EU Regulation (EC) No 1223/2009. Certain nanomaterials require notification to the European Commission through the Cosmetic Product Notification Portal (CPNP) before being placed on the market, and specific safety assessment requirements may apply.

The SCCS has published dedicated guidance and scientific opinions concerning the safety assessment of nanomaterials used as cosmetic ingredients. These documents provide guidance on the data and testing considerations needed for an appropriate safety dossier.

References

SCCS Notes of guidance for the testing of cosmetic ingredients and their safety evaluation.