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Annex II Entry 1258 15/10/2010

3,3'-(Sulfonylbis(2-nitro-4,1-phenylene)imino)bis(6-(phenylamino))benzenesulfonic acid and its salts, when used as a substance in hair dye products

3,3'-(Sulfonylbis(2-nitro-4,1-phenylene)imino)bis(6-(phenylamino))benzenesulfonic acid 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.

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Prohibited substance— Annex II, EU Regulation 1223/2009
Entry: 1258

Chemical identity and properties

PubChem 2D chemical structure for CAS 6373-79-1
CAS 6373-79-1PubChem CID 6454704

Benzenesulfonic acid, 3,3'-[sulfonylbis[(2-nitro-4,1-phenylene)imino]]bis[6-(phenylamino)-, sodium salt (1:2)

IUPAC name
disodium;2-anilino-5-[4-[4-(4-anilino-3-sulfonatoanilino)-3-nitrophenyl]sulfonyl-2-nitroanilino]benzenesulfonate
Molecular formula
C36H26N6Na2O12S3
Molecular weight
876.8 g/mol
Exact mass
876.05662237 Da
Topological polar surface area
313.0 Ų
Hydrogen-bond donors
4
Hydrogen-bond acceptors
16
Covalent units
3
Defined stereocentres
0

Also known as

Benzenesulfonic acid, 3,3'-(sulfonylbis((2-nitro-4,1-phenylene)imino))bis(6-(phenylamino)-, disodium saltBenzenesulfonic acid, 3,3'-(sulfonylbis((2-nitro-4,1-phenylene)imino))bis(6-(phenylamino)-, sodium salt (1:2)Benzenesulfonic acid, 3,3'-[sulfonylbis[(2-nitro-4,1-phenylene)imino]]bis[6-(phenylamino)-, disodium saltRefChem:564237ACID BROWN 13C.I. Acid Brown 13EINECS 228-922-0Disodium 3,3'-(sulphonylbis((2-nitro-p-phenylene)imino))bis(6-anilinobenzenesulphonate)
3 more reported names
UFCUKOZJEBIMQY-UHFFFAOYSA-LBenzenesulfonic acid, 3,3a(2)-[sulfonylbis[(2-nitro-4,1-phenylene)imino]]bis[6-(phenylamino)-, sodium salt (1:2)Disodium 3,3'-{sulfonylbis[(2-nitro-4,1-phenylene)azanediyl]}bis(6-anilinobenzene-1-sulfonate)
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

Chemical name

3,3'-(Sulfonylbis(2-nitro-4,1-phenylene)imino)bis(6-(phenylamino))benzenesulfonic acid 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
6373-79-1
EC
228-922-0
Annex
II
Entry number
1258

Inventory links for 3,3'-(Sulfonylbis(2-nitro-4,1-phenylene)imino)bis(6-(phenylamino))benzenesulfonic acid and its salts, when used as a substance in hair dye products

Inventory Restriction reference
Ref 31614

ACID BROWN 13

CAS: 6373-79-1
EC: 228-922-0

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

What Annex II means for 3,3'-(Sulfonylbis(2-nitro-4,1-phenylene)imino)bis(6-(phenylamino))benzenesulfonic acid and its salts, when used as a substance in hair dye products

3,3'-(Sulfonylbis(2-nitro-4,1-phenylene)imino)bis(6-(phenylamino))benzenesulfonic acid 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. 3,3'-(Sulfonylbis(2-nitro-4,1-phenylene)imino)bis(6-(phenylamino))benzenesulfonic acid 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 6373-79-1 is the unique numerical identifier assigned to 3,3'-(Sulfonylbis(2-nitro-4,1-phenylene)imino)bis(6-(phenylamino))benzenesulfonic acid 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.
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Source note for Annex II record 3,3'-(Sulfonylbis(2-nitro-4,1-phenylene)imino)bis(6-(phenylamino))benzenesulfonic acid and its salts, when used as a substance in hair dye products

This page summarizes one Annex II record for 3,3'-(Sulfonylbis(2-nitro-4,1-phenylene)imino)bis(6-(phenylamino))benzenesulfonic acid 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 3,3'-(Sulfonylbis(2-nitro-4,1-phenylene)imino)bis(6-(phenylamino))benzenesulfonic acid 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.

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