# D&C BLUE NO. 4

URL: https://app.greenveil.ai/ingredients/ingredient_dtxsid_dtxsid701021541
Categories: beauty
Functions: Hair dyeing
Identifier: DTXSID701021541

> D&C BLUE NO. 4: Used in cosmetics as a hair dye. Acid Blue 9 Ammonium Salt is classed chemically as a triphenylmethane colour. EPA DSSTox provides the canonical identifier, structure, and synonym profile for this chemical. Compiled from 4 published data sources.

## Safety assessment

- Chemical concern: not yet assessed
- Is it a concern? We haven't assessed a concern score for this ingredient yet. It is listed for cosmetic use in the EU.
- Rationale: EPA DSSTox provides the canonical identifier, structure, and synonym profile for this chemical.

## Regulatory status

- EU: Active — Acid Blue 9 Ammonium Salt is classed chemically as a triphenylmethane colour. It conforms to the formula: Restriction: III/190
- US: listed in openFDA substance — openFDA substance registry classifies this ingredient as mixture.

## Expert safety opinions

- SCCS (EU Scientific Committee on Consumer Safety): no opinion on file.
- CIR (Cosmetic Ingredient Review (US expert panel)): no opinion on file.

## Data sources

- CosIng (updated 2026-09-23): https://ec.europa.eu/growth/tools-databases/cosing/details/54158
- EPA DSSTox Identifiers (updated 2025-12-29): https://epa.figshare.com/articles/dataset/Chemistry_Dashboard_Data_DSSTox_Identifiers_Mapped_to_CAS_Numbers_and_Names/5588566
- FDA GSRS UNII (updated 2026-02-26): https://precision.fda.gov/uniisearch/
- openFDA Substance (updated 2026-05-24): https://api.fda.gov/other/substance.json?search=unii:0KSY80VYS3

_Assessed by Greenveil._