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Annex IV Entry 24 14/08/2020

Sodium 4-[(2-Hydroxy-1-naphthyl)azo]naphthalenesulphonate

CI 15620

Sodium 4-[(2-Hydroxy-1-naphthyl)azo]naphthalenesulphonate appears in Annex IV as a positive-list colorant entry for EU cosmetics. Maximum concentration in this record: Rinse-off products.

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Permitted colorant— Annex IV, EU Regulation 1223/2009
Max conc.: Rinse-off products
Entry: 24

Chemical identity and properties

PubChem 2D chemical structure for CAS 1658-56-6
CAS 1658-56-6PubChem CID 135465069

Acid red 88

IUPAC name
sodium 4-[(2-hydroxynaphthalen-1-yl)diazenyl]naphthalene-1-sulfonate
Molecular formula
C20H13N2NaO4S
Molecular weight
400.4 g/mol
Exact mass
400.04937236 Da
Topological polar surface area
111.0 Ų
Hydrogen-bond donors
1
Hydrogen-bond acceptors
6
Covalent units
2
Defined stereocentres
0

Also known as

RoccelineRoccellineFast red SACIDRED88Pontacyl Fast Red ASC.I. ACID RED 88C.I. Acid Red 88, monosodium saltCI 15620
16 more reported names
4-((2-Hydroxy-1-naphthalenyl)azo)1-naphthalenesulfonic acid sodium saltC20H13N2NaO4S1-Naphthalenesulfonic acid, 4-((2-hydroxy-1-naphthalenyl)azo)-, monosodium salt7Z2135Z4K4PeonyToyo roccellineNitto roccellineRoccelline ARoccelline KRoccelline LRoccelline SRoccelline KGRoccelline NSAcid cardinal Gsodium;4-[(2-hydroxynaphthalen-1-yl)diazenyl]naphthalene-1-sulfonateAnthrosin BRX
Open full PubChem recordPubChem annotations3D structure image
External database identifiers

Retrieved from NIH PubChem on 2026-09-02 by checksum-valid CAS matching. Chemical properties do not replace the regulatory decision on this page.

Record details

Maximum concentration

Rinse-off products

Colour index or glossary

CI 15620

Chemical name

Sodium 4-[(2-Hydroxy-1-naphthyl)azo]naphthalenesulphonate

Chemical / IUPAC name

Sodium 4-[(2-Hydroxy-1-naphthyl)azo]naphthalenesulphonate

Color

Red

Regulatory information

Regulation

(EC) 2009/1223

See every entry this act set

Identified ingredients

Key data

CAS
1658-56-6
EC
216-760-3
Annex
IV
Entry number
24

Inventory links for Sodium 4-[(2-Hydroxy-1-naphthyl)azo]naphthalenesulphonate

Inventory Restriction reference
Ref 32717

CI 15620

CAS: 1658-56-6
EC: 216-760-3

Direct matches are limited for this record, so nearby entries from Annex IV are shown as well.

Annex IV 23
Nearby record in the same annex

CI 15580

CAS: 5850-87-3
EC: 227-459-1
Annex IV 25
Nearby record in the same annex

CI 15630

CAS: 1248-18-6
EC: 214-998-2
Annex IV 22
Nearby record in the same annex

CI 15525

CAS: 5850-80-6
EC: 227-456-5
Annex IV 26
Nearby record in the same annex

CI 15800

CAS: 6371-76-2
EC: 228-899-7
Annex IV 21
Nearby record in the same annex

CI 15510

CAS: 633-96-5
EC: 211-199-0
Annex IV 27
Nearby record in the same annex

CI 15850

EC: 226-109-5
Annex IV 20
Nearby record in the same annex

CI 14815

CAS: 3257-28-1
EC: 221-856-3
Annex IV 28
Nearby record in the same annex

CI 15865

CAS: 3564-21-4; 5280-66-0
EC: 222-642-2
Annex IV 19
Nearby record in the same annex

CI 14720

CAS: 3567-69-9
EC: 222-657-4
Annex IV 29
Nearby record in the same annex

CI 15880

CAS: 6417-83-0
EC: 229-142-3
Annex IV 30
Nearby record in the same annex

CI 15980

CAS: 2347-72-0
EC: 219-073-7

What Annex IV means for Sodium 4-[(2-Hydroxy-1-naphthyl)azo]naphthalenesulphonate

Sodium 4-[(2-Hydroxy-1-naphthyl)azo]naphthalenesulphonate is an approved colorant listed in Annex IV of EU Cosmetics Regulation 1223/2009. Only colorants on this positive list may be used to colour cosmetic products on the EU market.

Some colorants in Annex IV are restricted by product type — for example, prohibited from use around the eyes or in products applied to mucous membranes. Check the product type and conditions fields above before use.

This record is linked to 1 CosIng inventory ingredient for name and identifier cross-reference. The page also surfaces 12 related annex records with overlapping identifiers, annex logic or naming patterns.

Compliance checklist

  • Confirm colorant is used only in permitted product types listed above.
  • Record the Colour Index number and CAS identifier in the ingredient declaration.

Frequently asked questions

Yes. Sodium 4-[(2-Hydroxy-1-naphthyl)azo]naphthalenesulphonate is included in Annex IV of EU Cosmetics Regulation 1223/2009 as a permitted colorant. Only colorants on this positive list may be used to colour cosmetic products in the EU. Check the product type conditions above for any use restrictions.

CAS 1658-56-6 is the unique numerical identifier assigned to Sodium 4-[(2-Hydroxy-1-naphthyl)azo]naphthalenesulphonate by the Chemical Abstracts Service. In cosmetic compliance work, the CAS number is used to cross-reference the substance across regulatory databases, raw material specifications and safety assessment reports. Multiple EU annex entries may share the same CAS number if the same substance appears under different conditions or in different annexes.

The maximum concentration of Rinse-off products applies to the concentration of the substance in the ready-to-use cosmetic product. When the substance is supplied as part of a blend or mixture, the calculation must account for the contribution of all sources in the formulation. The combined concentration must not exceed the stated limit.

Use the INCI Checker tool on this site to paste your full ingredient list (INCI) and scan it against all Annex II–VI entries. The tool highlights any ingredients that match restricted, prohibited or allergen-flagged records. This is useful for rapid compliance screening of finished product formulas or raw material declarations.
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Source note for Annex IV record Sodium 4-[(2-Hydroxy-1-naphthyl)azo]naphthalenesulphonate

This page summarizes one Annex IV record for Sodium 4-[(2-Hydroxy-1-naphthyl)azo]naphthalenesulphonate from public European Commission cosmetic materials and adds linked inventory or identifier matches when available.

Use this record page to review Annex IV conditions for Sodium 4-[(2-Hydroxy-1-naphthyl)azo]naphthalenesulphonate, but confirm any final regulatory decision against the current official annex wording and source files.

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