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CAS 2 records

CAS 3567-66-6

CAS 3567-66-6 matches 2 EU annex records across Annex II–VI of Regulation 1223/2009.

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Chemical identity and properties

PubChem 2D chemical structure for CAS 3567-66-6
CAS 3567-66-6PubChem CID 19116

Azo fuchsine

IUPAC name
disodium;5-amino-4-hydroxy-3-phenyldiazenylnaphthalene-2,7-disulfonate
Molecular formula
C16H11N3Na2O7S2
Molecular weight
467.4 g/mol
Exact mass
466.98338061 Da
Topological polar surface area
202.0 Ų
Hydrogen-bond donors
2
Hydrogen-bond acceptors
10
Covalent units
3
Defined stereocentres
0

Also known as

Acid red 33D.C. Red No. 33C.I. ACID RED 33AZOFUCHSIND&C Red 33D&C Red No. 33Azo grenadineC.I. Acid Red 33, disodium salt
16 more reported names
Acid fuchsine DRedusol ZAzo magenta GCerticol Red BFast acid magentaHexalan Red BAcetyl Red BNaphthalene Red BColacid Red 2AAcid Red BHispacid Fuchsin BBrasilan fuchsine DHexacol Red 10BAmacid fuchsine 4BEniacid fuchsine BNAcid Red 2A
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.

Records for CAS 3567-66-6

2 total
Annex
III
Entry
254

ACID RED 33

Disodium 5-amino-4-hydroxy-3-(phenylazo)naphathlene-2,7-disulphonate (see note 17); (CI 17200)

Hair dye substance in non-oxidative hair dye products

EC
222-656-9
Max concentration
Annex
IV
Entry
37

CI 17200

Disodium 5-amino-4-hydroxy-3-(phenylazo)naphthalene-2,7-disulphonate and its unsoluble barium, strontium and zirconium lakes, salts and pigments
EC
222-656-9

How CAS 3567-66-6 is used on this site

CAS 3567-66-6 is the Chemical Abstracts Service identifier used to pin this page to a specific substance. In the current dataset, 2 EU annex records share this identifier, which helps you cross-check whether the same substance appears under one regulatory context or several.

Use this page when a supplier specification, SDS or raw-material dossier gives you CAS 3567-66-6 and you need to see every linked Annex II–VI record in one place. The entry cards above are the quickest route to concentration limits, warnings, annex placement and product-type conditions.

Frequently asked questions

A substance identified by CAS 3567-66-6 may appear in multiple EU cosmetic regulation annexes when it is subject to different conditions in different contexts. For example, a substance might be restricted under Annex III with specific conditions, and the same CAS might also appear in Annex IV as an approved colorant under separate entry conditions. Each entry must be reviewed individually.

Cross-reference the CAS number against your raw material specification sheets and CoA documents. When a CAS appears in Annex II, verify absence. When it appears in Annex III, verify that concentration limits and product type conditions are met in your formulation. All annex entries sharing this CAS number are listed above.

A CAS number is assigned by the Chemical Abstracts Service (USA) and is globally recognised. An EC number is a European Commission identifier from inventories such as EINECS, ELINCS or the NLP list. Both identifiers may appear in EU cosmetic annex entries. Some substances have both, some have only one, and some older entries may have neither.

The INCI Checker accepts ingredient names, CAS numbers and EC numbers. Check this CAS number directly, then verify the result against supplier specification sheets and every linked annex condition.
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