Skip to main content
CosIng Checker
CosIng Checker
EU cosmetic ingredients, restrictions and safety
Login
Annex II Entry 1267 15/10/2010

2-Naphthalenesulfonic acid, 7-(benzoylamino)-4-hydroxy-3-[[4-[(4-sulfophenyl)azo]phenyl]azo]- and its salts, when used as a substance in hair dye products

2-Naphthalenesulfonic acid, 7-(benzoylamino)-4-hydroxy-3-[[4-[(4-sulfophenyl)azo]phenyl]azo]- and its salts, when used as a substance in hair dye products is listed in Annex II as a prohibited substance for cosmetic products placed on the EU market.

Search similar Back to annex Compare
Prohibited substance— Annex II, EU Regulation 1223/2009
Entry: 1267

Chemical identity and properties

PubChem 2D chemical structure for CAS 2610-11-9
CAS 2610-11-9PubChem CID 17462

C.I. Direct Red 81 disodium salt

Sirius red 4B is an organic sodium salt resulting from the formal condensation of Sirius red 4B (acid form) with two equivalents of sodium hydroxide. Used as the plasma stain in some trichrome staining methods. It has a role as a fluorochrome, a poison, a histological dye and an environmental contaminant. It contains a Sirius red 4B(2-). — ChEBI

IUPAC name
disodium;7-benzamido-4-hydroxy-3-[[4-[(4-sulfonatophenyl)diazenyl]phenyl]diazenyl]naphthalene-2-sulfonate
Molecular formula
C29H19N5Na2O8S2
Molecular weight
675.6 g/mol
Exact mass
675.04704349 Da
Topological polar surface area
230.0 Ų
Hydrogen-bond donors
2
Hydrogen-bond acceptors
12
Covalent units
3
Defined stereocentres
0

Also known as

RefChem:1080560DIRECT RED 81Chlorantine Fast Red 5BSolaminrot 4BAiredale Red KDC.I. Direct Red 81Sirius Red 4BCalcodur Red 8BL
16 more reported names
Triantine Light Red 4BNCHLORANTINEFASTRED5BDirect Fast Red 5BBordeaux EMBLSaturn Red BSolar Red BDurazol Red 2BDurazol Red 2BPFenaluz Red 4BSumilight Red 4BSuprazo Red 4BEliamina Red 8BLHelion Red 8BHispaluz Red 8BLSirius Red 4BASolius Red 4B
Open full PubChem recordPubChem annotations3D structure image
External database identifiers

Retrieved from NIH PubChem on 2026-08-31 by checksum-valid CAS matching. Chemical properties do not replace the regulatory decision on this page.

Record details

Chemical name

2-Naphthalenesulfonic acid, 7-(benzoylamino)-4-hydroxy-3-[[4-[(4-sulfophenyl)azo]phenyl]azo]- and its salts, when used as a substance in hair dye products

Regulatory information

Regulation

(EC) 2009/1223

See every entry this act set

SCCS opinions

Identified ingredients

Key data

CAS
2610-11-9
EC
220-028-9
Annex
II
Entry number
1267

Inventory links for 2-Naphthalenesulfonic acid, 7-(benzoylamino)-4-hydroxy-3-[[4-[(4-sulfophenyl)azo]phenyl]azo]- and its salts, when used as a substance in hair dye products

Inventory Restriction reference
Ref 33568

DIRECT RED 81

CAS: 2610-11-9
EC: 220-028-9

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

What Annex II means for 2-Naphthalenesulfonic acid, 7-(benzoylamino)-4-hydroxy-3-[[4-[(4-sulfophenyl)azo]phenyl]azo]- and its salts, when used as a substance in hair dye products

2-Naphthalenesulfonic acid, 7-(benzoylamino)-4-hydroxy-3-[[4-[(4-sulfophenyl)azo]phenyl]azo]- and its salts, when used as a substance in hair dye products is listed as a prohibited substance under Annex II of EU Cosmetics Regulation 1223/2009 and must not be intentionally added. Article 17 separately addresses unintended small quantities that are technically unavoidable under good manufacturing practice and compatible with the Article 3 safety requirement.

Formulators must screen their ingredients and raw materials to ensure none contain this substance. Suppliers should provide documentation confirming absence when requested.

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

  • Verify this substance is absent from all raw materials and finished formulations.
  • Request absence confirmation or CoA from raw material suppliers.
  • Document the screening result in the Product Information File (PIF).

Frequently asked questions

Yes. 2-Naphthalenesulfonic acid, 7-(benzoylamino)-4-hydroxy-3-[[4-[(4-sulfophenyl)azo]phenyl]azo]- and its salts, when used as a substance in hair dye products is listed in Annex II of EU Cosmetics Regulation 1223/2009 and is prohibited as an intentionally added cosmetic ingredient. Article 17 provides a narrow exception for unintended small quantities that are technically unavoidable under good manufacturing practice, provided the product remains safe under Article 3.

CAS 2610-11-9 is the unique numerical identifier assigned to 2-Naphthalenesulfonic acid, 7-(benzoylamino)-4-hydroxy-3-[[4-[(4-sulfophenyl)azo]phenyl]azo]- and its salts, when used as a substance in hair dye products 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.

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.
Open INCI Checker

Source note for Annex II record 2-Naphthalenesulfonic acid, 7-(benzoylamino)-4-hydroxy-3-[[4-[(4-sulfophenyl)azo]phenyl]azo]- and its salts, when used as a substance in hair dye products

This page summarizes one Annex II record for 2-Naphthalenesulfonic acid, 7-(benzoylamino)-4-hydroxy-3-[[4-[(4-sulfophenyl)azo]phenyl]azo]- and its salts, when used as a substance in hair dye products from public European Commission cosmetic materials and adds linked inventory or identifier matches when available.

Use this record page to review Annex II conditions for 2-Naphthalenesulfonic acid, 7-(benzoylamino)-4-hydroxy-3-[[4-[(4-sulfophenyl)azo]phenyl]azo]- and its salts, when used as a substance in hair dye products, but confirm any final regulatory decision against the current official annex wording and source files.

View sourcesView updates

Tools & next steps

Check your formula

Paste a full INCI list to detect 2-Naphthalenesulfonic acid, 7-(benzoylamino)-4-hydroxy-3-[[4-[(4-sulfophenyl)azo]phenyl]azo]- and its salts, when used as a substance in hair dye products and other flagged EU annex records in one pass.

INCI Checker

Compare entries

Compare 2-Naphthalenesulfonic acid, 7-(benzoylamino)-4-hydroxy-3-[[4-[(4-sulfophenyl)azo]phenyl]azo]- and its salts, when used as a substance in hair dye products side by side with another annex record to review differences in restrictions, concentrations and annex placement.

Compare

Browse the annex

See all records in Annex II and compare regulatory conditions across substances in this annex.

Open Annex II