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Acid Orange 24 (CI 20170), when used as a substance in hair dye products

CAS 1320-07-6 · 100/100 · High conf.

Also registered as 1 other CAS number

6371-84-2

Concern score

100/100Critical concern based on regulatory listings.
High confidence

Acid Orange 24 (CI 20170), when used as a substance in hair dye products in plain language

What it is

On cosmetic ingredient lists it appears as “Acid orange 24”.

Also known as Acid orange 24 · CI 20170 · Brown 1

What it does

Used in cosmetics as a colourant and a hair dye.

  • Colorant
  • Hair dyeing
  • Colourant
Is it a concern?
Critical concern: no hazard classifications on record. It is banned in EU cosmetics.

Why it's flagged

Acid Orange 24 (CI 20170), when used as a substance in hair dye products is prohibited in cosmetic products under Annex II of the EU Cosmetics Regulation (EC) 1223/2009.

RestrictedEU EC — banned

The score describes this ingredient's chemical identity — its hazard profile from published classifications and regulatory status — not the safety of any product it appears in.

Regulation

Restrictions first, then routine listings from published regulatory sources.

  • EU Annex II — prohibited
  • EU prohibited in cosmetics

Recorded in these product areas

  • Found in consumer products
  • Industrial
  • EUEC

    Annex II of EU Cosmetics Regulation (EC) 1223/2009: substances prohibited in cosmetic products.

    banned
    View source →
  • EUCosIngActive2 entries
  • USEPAcommercial use observedEPA CPDat observed this chemical in 0 composition records across product categories including unclassified products. EPA CPDat classifies this chemical for functional uses including Dye.
    • EPA CPDat observed this chemical in 0 composition records across product categories including unclassified products. EPA CPDat classifies this chemical for functional uses including Dye.Source →
  • USFDAlisted in openFDA substanceopenFDA substance registry classifies this ingredient as chemical.
    • openFDA substance registry classifies this ingredient as chemical.Source →

Expert safety opinions

No expert opinion on file for Acid Orange 24 (CI 20170), when used as a substance in hair dye products. These are the independent scientific bodies that assess ingredients like this one; we show an opinion only when a record we hold cites it.

  • SCCS

    EU Scientific Committee on Consumer Safety

    No SCCS opinion on file.

  • CIR

    Cosmetic Ingredient Review (US expert panel)

    No CIR safety assessment on file.

Evidence & sources

No graded research studies for Acid Orange 24 (CI 20170), when used as a substance in hair dye products yet. This record is compiled from the published data sources below — registries and regulatory listings, not study findings.

6 data sources

Where this comes from

  • CosIng

    regulatory · updated 2026-09-23

    Open →
  • EU CosIng Cosmetics Regulation Annexes

    regulatory · updated 2010-10-21

    Open →
  • EPA Chemical and Products Database

    exposure · updated 2020-03-27

    Open →
  • EPA DSSTox Identifiers

    chemistry · updated 2025-12-29

    Open →
  • FDA GSRS UNII

    registry · updated 2026-02-26

    Open →
  • openFDA Substance

    registry · updated 2026-05-24

    Open →

Suitability

Context-specific fit derived from published classifications and the current ingredient evidence profile.

Fragrance avoidance

No fragrance-linked caution surfaced in the current profile.

Good fit

This ingredient does not currently read as a fragrance-linked driver in the published evidence and hazard profile.

Where it has been recorded

How often EPA CPDat has listed Acid Orange 24 (CI 20170), when used as a substance in hair dye products in a product composition. These are source records, not Greenveil catalog products.

Named organisations

1

Typical roles

ColorantHair dyeingColourant
See products using Acid Orange 24 (CI 20170), when used as a substance in hair dye products →

Catalog

Found in these products

Cosmetic and personal-care products that list Acid Orange 24 (CI 20170), when used as a substance in hair dye products are shown first. Their ingredient lists include Acid Orange 24 (CI 20170), when used as a substance in hair dye products; each product's own rating depends on its whole formula, so it is shown on the product page, not here.