Is TROPOLONE safe to use in EU cosmetics?

TROPOLONE is listed in the EU CosIng ingredient inventory with no direct annex restriction records linked at this time. Always verify against the current official CosIng database before formulating.

What other records share CAS 533-75-5?

CAS 533-75-5 may appear across multiple EU annex records. The CAS lookup page shows all Annex II–VI entries sharing this identifier, useful for identifying cross-annex regulatory status of the same chemical substance.

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Use the INCI Checker to screen a full ingredient list across selected markets, or use the substance market comparison to review this identity across all supported market datasets.

InventoryRef 8136315/10/2010

TROPOLONE

2-Hydroxycyclohepta-2,4,6-trienone; 2-Hydroxytropone

TROPOLONE is listed in the EU CosIng inventory, but no direct annex records are linked on this page yet.

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Regulatory evidence by market

No rule for this ingredient has been imported for any of the 13 markets tracked here.

That describes this inventory, not the law. No imported rule is not evidence that an ingredient is permitted: a rule may exist under another name or identifier, or in a dataset not yet imported here.

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Chemical identity and properties

PubChem 2D chemical structure for CAS 533-75-5

CAS 533-75-5PubChem CID 10789

Tropolone

Tropolone is a cyclic ketone that is cyclohepta-2,4,6-trien-1-one substituted by a hydroxy group at position 2. It is a toxin produced by the agricultural pathogen Burkholderia plantarii. It has a role as a fungicide, a toxin and a bacterial metabolite. It is an alpha-hydroxy ketone, an enol and a cyclic ketone. It derives from a hydride of a cyclohepta-1,3,5-triene. — ChEBI

IUPAC name: 2-hydroxycyclohepta-2,4,6-trien-1-one

Molecular formula: C7H6O2
Molecular weight: 122.12 g/mol
Exact mass: 122.036779430 Da
XLogP3: 0.5
Topological polar surface area: 37.3 Å²
Hydrogen-bond donors: 1
Hydrogen-bond acceptors: 2
Covalent units: 1
Defined stereocentres: 0

Also known as

2-Hydroxycyclohepta-2,4,6-trienonePurpurocatechol2-Hydroxytropone2,4,6-Cycloheptatrien-1-one, 2-hydroxy-7L6DL16P1TNSC-89303CHEBI:79966RefChem:389350

16 more reported names

208-577-22-Hydroxy-2,4,6-cycloheptatrien-1-one2-Hydroxy-2,4,6-cycloheptatrienoneCCRIS 66092-Hydroxy-2,4,6-cycloheptatriene-1-oneAC1614Tropolone, purum, >=98.0% (GC)2-hydroxy-2,4,6-cycloheptatrien -1-onetropolonEINECS 208-577-2NSC 89303BRN 1904978UNII-7L6DL16P1TTropomyosins0TRTropolone, 98%

Open full PubChem record PubChem annotations 3D structure image

External database identifiers

ChEBI:CHEBI:79966
ChEMBL:CHEMBL121188
EPA DTXSID:DTXSID8049416
PubMed:23032214
PubMed:23025237
PubMed:22926028
PubMed:22917559
PubMed:22885403
PubMed:22863449
PubMed:22805928
PubMed:22590003
PubMed:22507316
PubMed:22450442
PubMed:22419431
PubMed:22416696

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

Inventory details for TROPOLONE

INCI name

TROPOLONE

Description

2-Hydroxycyclohepta-2,4,6-trienone; 2-Hydroxytropone

Record provenance

Inventory reference: 81363
Imported identity: TROPOLONE
Source update: 15/10/2010

European Commission CosIng source notes

Annex records for TROPOLONE

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Key data

CAS

533-75-5

208-577-2

Restriction

—

Function

SKIN CONDITIONING: Maintaining the skin in good condition.

Official EU ingredient-name evidence

The ingredient name exactly matches the official 2025 EU glossary of common ingredient names.

#29544 · TROPOLONE

Ingredients with overlapping formulation functions

TROPAEOLUM MAJUS FLOWER/LEAF EXTRACTREFRESHING, SKIN CONDITIONING

TROPAEOLUM MAJUS FLOWER/LEAF/STEM EXTRACTSKIN CONDITIONING

TROPAEOLUM MAJUS LEAF EXTRACTSKIN CONDITIONING

TROPAEOLUM MAJUS SEED EXTRACTSKIN CONDITIONING

TROXERUTINSKIN CONDITIONING

TRYPSINHAIR CONDITIONING, SKIN CONDITIONING

TSUGA CANADENSIS BARK EXTRACTSKIN CONDITIONING

TSUGA CANADENSIS OILFRAGRANCE, SKIN CONDITIONING

Additional official and scientific sources

11 external databases to check this identity in

Each link searches that source for this identity. What each source is, and its legal weight

ECHA CHEM / Information on chemicals PubChem PUG REST EU Safety Gate cosmetic product alerts ECHA CHEM US EPA CompTox Cosmetic Ingredient Review safety assessments FDA Global Substance Registration System ILO/WHO International Chemical Safety Cards Japan NITE-CHRIP NIOSH Pocket Guide to Chemical Hazards OECD eChemPortal

How TROPOLONE appears in the CosIng inventory

The CosIng inventory lists TROPOLONE as a cosmetic ingredient and this page links it to 0 annex records. The inventory entry captures names and identifiers, while the annex records show where the substance is prohibited, restricted or positively listed in EU cosmetics law.

TROPOLONE is also tagged with 1 cosmetic function in the official data. Function labels describe intended use, but they do not replace regulatory review of linked annex records before formulation or labelling work.

Frequently asked questions

TROPOLONE is listed in the EU CosIng ingredient inventory with no direct annex restriction records linked at this time. Absence of an annex link does not guarantee unrestricted use — always verify against the current official CosIng database before formulating.

According to the EU CosIng inventory, TROPOLONE carries the following function designation(s):

SKIN CONDITIONING

CAS 533-75-5 may appear across multiple EU annex records. Viewing the CAS lookup page shows all Annex II–VI entries sharing this identifier, which is useful for identifying cross-annex regulatory status of the same chemical substance.

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Source note for TROPOLONE

This page reproduces the CosIng inventory entry for TROPOLONE from public European Commission cosmetic ingredient materials and shows linked identifiers even when no direct annex match is currently attached.

Use this inventory page to research TROPOLONE and compare linked records, but verify restrictions and legal status against the current official source text and law before making regulatory decisions.

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