EU publishes major revisions in nanomaterial cosmetic guide to help prepare safety dossiers

29 Jun 2023 --- The SCCS (Scientific Committee on Consumer Safety) has, for the second time, revised the guidance on the safety assessment of nanomaterials in cosmetics. The committee continues to alter the guidance as science advances. Meanwhile, the EU Commission’s (EC) Joint Research Centre (JRC) released a document on implementing the definition of nanomaterial, which is included in the guidance.

“The new EC recommendation on the definition of nanomaterial 2022/C 229/01 is the result of a review of the previous definition 2011/696/EU followed by a revision process, carried out between 2013 and 2021,” outlines the JRC report.

Meanwhile, the SCCS’s guidance applies to any nanomaterial that meets the criteria outlined in the Cosmetic Regulation (EC) No 1223/2009: “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.”

SCCS’s guidance aims to help applicants go through the procedure of preparing safety dossiers. It is also to assist risk assessors and risk managers.

Aligning nanomaterial definitions
The EC defines nanomaterials based on their nano-scale dimensions – “the only common feature” to such materials.

When evaluating materials, it will only be considered a nanomaterial if 50% or more of its constituent particles fulfill one of three conditions:“It may be mistaken to claim that materials that show partial dissolution over a long period are ‘soluble,’ and therefore not a nanomaterial,” flags SCCS.

“One or more external dimensions of the particle are in size range 1 nm to 100 nm; the particle has an elongated shape, such as a rod, fiber or tube, where two external dimensions are smaller than 1 nm and the other dimension is larger than 100 nm; the particle has a plate-like shape, where one external dimension is smaller than 1 nm and the other dimensions are larger than 100 nm.”

However, the SCCS flags that this recommendation has yet to be applied to the definition of nanomaterials in the Cosmetic Regulation.

“It is recommended that applicants keep it in mind when assessing the safety of the materials used in cosmetics that are comprised of or consist of small particles or exhibit a size-related change in properties, behavior and/or effects compared to the conventional (bulk) ingredients,” advises the committee.

This is because EC’s recommended definition of nanomaterial is “likely” to be aligned with the Cosmetic Regulation in the future.

Summary of revisions
With the new revisions, the SCCS has introduced new sections on solubility and dissolution rates, solubility in non-aqueous media, evidence for the absence of nanoparticles, dispersion, aspect ratio, uptake into blood cells, reproductive toxicity and endocrine disruption.

The EC’s recommendation for a definition of nanomaterials was published in 2022 and a text explaining when historical/existing data can be used has also been introduced.

Other additions include “key aspects triggering safety concerns over a nanomaterial based on SCCS/1618/2020.” While sections and Annex 1 have been updated with the latest literature since the last update in October 2019.

The section on read-across and grouping has also been revised.

Highlighting a potential mistake
The SCCS is contesting the word “insoluble” in the Cosmetic Regulation definition of nanomaterials based on a question of interpretation.

“For example, nanomaterials that only show a partial solubility may be regarded as ‘soluble’ in relative terms. However, it needs to be considered whether the nanomaterial is present in a cosmetic formulation in particulate form and if it is present for a specific functionality,” they flag.The EC defines nanomaterials based on their nano-scale dimensions.

“When dealing with the question of solubility, as provided in the current definition, it is important to note that any nano-specific risk may change (even diminish) when a nanomaterial is dissolved. But the time over which the dissolution happens determines the considerations for risk assessment based on either particle risk or soluble substance risk.”

Accordingly, with the current definition in the Cosmetic Regulation, “it may be mistaken to claim that materials that show partial dissolution over a long period are ‘soluble,’ and therefore not a nanomaterial.”

Developments in nanocosmetics
In related news, the SCCS deemed hydroxyapatite (nano) safe for use in oral health care products while outlining concentration limits.

The latest EU Observatory for Nanomaterials report predicted growth of the nanomaterial market within the continent from 2021 to 2025, where combined personal care and medicine sectors will lead to a “dominant segment” of 20.3%.

Meanwhile, a Slovenia-based study unveiled the “promising potential” of nanoformulations containing retinoids for topical delivery while underscoring a lack of large-scale research. However, other research flagged that the promising prospect of nanocosmetics has heightened concerns over health issues due to toxicity risks.

By Venya Patel

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