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Annex IV Entry 74 14/08/2020

Disodium 2-(3-oxo-6-oxidoxanthen-9-yl)benzoate

CI 45350

Disodium 2-(3-oxo-6-oxidoxanthen-9-yl)benzoate appears in Annex IV as a positive-list colorant entry for EU cosmetics.

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Permitted colorant— Annex IV, EU Regulation 1223/2009
Entry: 74

Chemical identity and properties

PubChem 2D chemical structure for CAS 518-45-6
CAS 518-45-6PubChem CID 3383

2-(6-Hydroxy-3-oxo-3H-xanthen-9-yl)benzoic acid

Fluorescein (acid form) is a xanthene dye that is highly fluorescent and commonly used as a fluorescent tracer. It has a role as a radioopaque medium and a fluorescent dye. It is a member of benzoic acids, an organic heterotricyclic compound, a member of phenols, a hydroxy monocarboxylic acid, a xanthene dye and a cyclic ketone. — ChEBI

IUPAC name
2-(3-hydroxy-6-oxoxanthen-9-yl)benzoic acid
Molecular formula
C20H12O5
Molecular weight
332.3 g/mol
Exact mass
332.06847348 Da
XLogP3
2.4
Topological polar surface area
83.8 Ų
Hydrogen-bond donors
2
Hydrogen-bond acceptors
5
Covalent units
1
Defined stereocentres
0

Also known as

flourescein1flr2-(6-HYDROXY-3-OXO-3H-XANTHEN-9-YL)-BENZOIC ACID2-(6-oxido-3-oxo-3H-xanthen-9-yl)benzoate2-(3-hydroxy-6-oxo-xanthen-9-yl)benzoic acid2-(6-hydroxy-3-oxoxanthen-9-yl)benzoic acid1n0sfluorescein (acid form)
16 more reported names
cid_3383CBDivE_002901CHEBI:172923HMS3752I07EBC-12373TG2-210NS-05493EN300-1728452-(6-Hydroxy-3-oxo-3H-xanthen-9-yl)benzoesaure2-(6-Hydroxy-3-oxo-3H-xanthen-9-yl)benzoicacid2-(3-hydroxy-6-oxo-6H-xanthen-9-yl)benzoic acid2-(6-Hydroxy-3-oxo-3H-xanthen-9-yl)benzoic acid #3H-Xanthen-3-one, 6-hydroxy-10-[2-carboxyphenyl]-3',6'-Dihydroxy-spiro[isobenzofuran-1(3H),9'-[9H]xanthen]-3-one(3H)Xanthen-3-one, 10-deshydro-6-hydroxy-10-[2-carboxyphen-1-yl]-3'',6''-dihydroxyspiro[1,3-dihydroisobenzofuran-1,9''-(9''H-xanthene)]-3-one
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.

PubChem 2D chemical structure for CAS 518-47-8
CAS 518-47-8PubChem CID 10608

Sodium Fluorescein

Fluorescein, disodium salt is an orange-red to dark red powder. Water-soluble form of fluorescein. Odorless and almost tasteless. pH (5% solution) 7.8. May be sensitive to prolonged exposure to light and to heat. — CAMEO Chemicals

IUPAC name
disodium;2-(3-oxido-6-oxoxanthen-9-yl)benzoate
Molecular formula
C20H10Na2O5
Molecular weight
376.3 g/mol
Exact mass
376.03236198 Da
Topological polar surface area
89.5 Ų
Hydrogen-bond donors
0
Hydrogen-bond acceptors
5
Covalent units
3
Defined stereocentres
0

Also known as

Fluorescein disodium saltSoluble fluoresceinUraninUranine WSSResorcinol phthalein sodiumUranine YellowAk-FluorFluorescein, soluble
16 more reported names
Ki202Sodium fluoresceinateFluoresceinum natricum93X55PE38XD&C Yellow No. 8Funduscein-25Ki202(1)Ki202(2)D & C Yellow no. 8disodium 2-(6-oxido-3-oxo-3H-xanthen-9-yl)benzoateCI 45350CI 45350 (Na salt)3',6'-Dihydroxyspiro(isobenzofuran-1(3H),9'-(9H)xanthen)-3-one, disodium saltRetinofluorGlostripsBioglo
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

Other restrictions

6%

Colour index or glossary

CI 45350

Chemical name

Disodium 2-(3-oxo-6-oxidoxanthen-9-yl)benzoate

Chemical / IUPAC name

Disodium 2-(3-oxo-6-oxidoxanthen-9-yl)benzoate

Color

Yellow

Regulatory information

Regulation

(EC) 2009/1223

See every entry this act set

Identified ingredients

Key data

CAS
518-45-6; 518-47-8
EC
-; 208-253-0
Annex
IV
Entry number
74

Inventory links for Disodium 2-(3-oxo-6-oxidoxanthen-9-yl)benzoate

Inventory Identified ingredient
Ref 54164

ACID YELLOW 73

CAS: 2321-07-5
EC: 219-031-8
Inventory Restriction reference
Ref 32767

CI 45350

CAS: 518-47-8 / 2321-07-5 / 6417-85-2
EC: 208-253-0 / 219-031-8 / 229-143-9

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

Annex IV 73
Nearby record in the same annex

CI 45220

CAS: 5873-16-5
EC: 227-528-6
Annex IV 75
Nearby record in the same annex

CI 45370

CAS: 596-03-2; 4372-02-5
EC: 209-876-0; 224-468-2
Annex IV 76
Nearby record in the same annex

CI 45380 / ACID RED 87

CAS: 17372-87-1 / 548-26-5 / 15876-39-8 / 15086-94-9 / 94021-89-3
EC: 241-409-6 / - / 240-005-7 / 239-138-3 / 301-481-2
Annex IV 77
Nearby record in the same annex

CI 45396

CAS: 24545-86-6
EC: 246-308-0
Annex IV 70
Nearby record in the same annex

CI 44090

CAS: 3087-16-9
EC: 221-409-2
Annex IV 78
Nearby record in the same annex

CI 45405

CAS: 6441-77-6
EC: 229-225-4
Annex IV 69
Nearby record in the same annex

CI 44045

CAS: 2580-56-5
EC: 219-943-6
Annex IV 79
Nearby record in the same annex

CI 45410

CAS: 18472-87-2
EC: 242-355-6
Annex IV 68
Nearby record in the same annex

CI 42735

CAS: 6505-30-2
EC: 229-390-2

What Annex IV means for Disodium 2-(3-oxo-6-oxidoxanthen-9-yl)benzoate

Disodium 2-(3-oxo-6-oxidoxanthen-9-yl)benzoate 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 3 CosIng inventory ingredients 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. Disodium 2-(3-oxo-6-oxidoxanthen-9-yl)benzoate 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 518-45-6; 518-47-8 is the unique numerical identifier assigned to Disodium 2-(3-oxo-6-oxidoxanthen-9-yl)benzoate 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 IV record Disodium 2-(3-oxo-6-oxidoxanthen-9-yl)benzoate

This page summarizes one Annex IV record for Disodium 2-(3-oxo-6-oxidoxanthen-9-yl)benzoate 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 Disodium 2-(3-oxo-6-oxidoxanthen-9-yl)benzoate, but confirm any final regulatory decision against the current official annex wording and source files.

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