SCCS/1670/24: HC Yellow No. 16 in Hair Dye Products Assessed as Safe

The Scientific Committee on Consumer Safety (SCCS) has re-assessed the hair dye HC Yellow No. 16. In its opinion SCCS/1670/24 of 25 October 2024, the Committee concludes that the substance is safe under defined conditions. The basis is the second submission dossier (Submission II) with data on new commercial batches.

Which substance is concerned

The assessment covered HC Yellow No. 16, listed under Colipa No. B123 and CAS No. 1184721-10-5. The substance is used as a hair dye. The abbreviation CAS stands for Chemical Abstracts Service, the system of globally unique substance numbers. The Colipa number is an industry identifier for cosmetic colorants.

The SCCS is the independent scientific body of the European Commission. At the Commission's request, it examines the safety of individual substances. Its opinions form the technical basis for later amendments to the annexes of Regulation (EU) 1223/2009 on cosmetic products. An SCCS opinion is not itself law. It describes the current state of scientific knowledge, which a possible regulatory decision can then be based on.

What the SCCS decided

The Commission put two questions to the Committee. The first concerned the safety of HC Yellow No. 16 when used as an ingredient in two application forms. The second question concerned any further possible scientific concerns.

On the first question, the SCCS reaches the following conclusion: the use of HC Yellow No. 16 (B123) is safe

• at a concentration of 1% in oxidative hair dye products and
• at a concentration of 1.5% in non-oxidative hair dye products.

The Committee explicitly ties this conclusion to the specifications of the new commercial batches as described in submission dossier II (section 3.1.4 of the opinion). The assessment therefore applies to material meeting these specifications, not to any quality of the substance in general.

On the second question regarding further scientific concerns, the opinion contains no substantive answer. The SCCS does not list any additional concerns at this point.

Oxidative and non-oxidative explained briefly

Oxidative hair dye products develop colour through a chemical reaction, usually with the addition of hydrogen peroxide. Non-oxidative products apply the finished dye directly to the hair. For both applications the SCCS states different safe maximum concentrations. This must be taken into account in formulation planning.

Who is affected by the assessment

The opinion is relevant primarily for manufacturers and marketers of hair dye products who use HC Yellow No. 16 or are considering its use. For them, the document provides the current scientific reference point on the substance's safety.

The link to the batch specification is important. The SCCS bases its conclusion on the new commercial batches described in the dossier. Anyone using the substance should check whether the raw material used matches these specifications. Purity profile and impurities play a central role in the safety assessment of colorants.

Relationship to the Cosmetics Regulation

Hair dyes are regulated under Regulation (EU) 1223/2009. Substances with special restrictions are listed in Annex III, together with the respective permitted maximum concentrations and conditions of use. Whether and when the Commission will convert the opinion SCCS/1670/24 into an entry or amendment is not specified in the opinion itself. The available material does not state a timeline for any possible legal change or transition periods.

For manufacturers this means: the current legal status of a substance always follows from the applicable wording of the annexes, not from an SCCS opinion alone. The opinion shows the scientific direction but does not replace a review of the Regulation.

What manufacturers should check now

Several action points can be derived from the opinion:

• Match the application form: Check whether the product is oxidative or non-oxidative, and take into account the respective stated concentration (1% or 1.5%).
• Check raw material specification: Clarify with the supplier whether the batch used matches the specifications described in Dossier II. A current certificate of analysis and purity data should be part of the documentation.
• Monitor the legal situation: Track developments in the annexes of Regulation (EU) 1223/2009 in order to respond to a possible future entry.
• Update the safety report: New scientific findings feed into the safety assessment (CPSR, Cosmetic Product Safety Report under Annex I). For formulations containing HC Yellow No. 16, it should be checked whether an update is advisable.

This is exactly where our services come in. We review formulations, incorporate new SCCS opinions into the existing product information file (PIF), and keep the documentation up to date following formulation or legal changes. The technical review and sign-off is carried out by a qualified safety assessor.

The full opinion is available as a PDF (SCCS/1670/24) on the European Commission's website: SCCS scientific Advice on HC Yellow No. 16 (Submission II). An overview of all SCCS opinions can be found here.