Is TELMESTEINE safe to use in EU cosmetics?

TELMESTEINE 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 122946-43-4?

CAS 122946-43-4 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.

How do I check if my formula contains TELMESTEINE?

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 3854115/10/2010

TELMESTEINE

3,4-Thiazolidinedicarboxylic acid, 3-ethyl ester, (R)-

TELMESTEINE 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 122946-43-4

CAS 122946-43-4PubChem CID 65946

Telmesteine

Telmesteine is an organonitrogen compound and an organooxygen compound. It is functionally related to an alpha-amino acid. — ChEBI

IUPAC name: (4R)-3-ethoxycarbonyl-1,3-thiazolidine-4-carboxylic acid

Molecular formula: C7H11NO4S
Molecular weight: 205.23 g/mol
Exact mass: 205.04087901 Da
XLogP3: 0.6
Topological polar surface area: 92.1 Å²
Hydrogen-bond donors: 1
Hydrogen-bond acceptors: 5
Covalent units: 1
Defined stereocentres: 1

Also known as

TelmesteinaReolaseTelmesteinum124I3FE35TtelmesteinRefChem:1877783-ethylhydrogen-3,4-thiazolidinedicarboxylateTelmesteine [INN]

16 more reported names

(R)-3-(Ethoxycarbonyl)thiazolidine-4-carboxylic acidTelmesteine (INN)(4R)-3-(ethoxycarbonyl)-1,3-thiazolidine-4-carboxylic acidTelmesteinum [INN-Latin]Telmesteina [INN-Spanish]UNII-124I3FE35TReolase (TN)TELMESTEINE [MART.]TELMESTEINE [WHO-DD]CHEBI:134866EBC-13371DA-68031HY-125495CS-0091938EN300-881275(-)-3-Ethyl hydrogen (R)-3,4-thiazolidinedicarboxylate

Open full PubChem record PubChem annotations 3D structure image

External database identifiers

ChEBI:CHEBI:134866
ChEMBL:CHEMBL2107621
EPA DTXSID:DTXSID60153804

Evidence from additional scientific databases

NIH PubChem PUG-View

Exact identifier match65946

Attributed physical-property, hazard, environmental and use annotations.

Mapped by: Existing checksum-valid CAS to unique PubChem CID match. Retrieved: 2026-08-31. Open source record

Scientific classifications and hazard annotations provide context and do not replace the market-specific regulatory decision shown above.

Additional source coverage and match status

Source	Result	Checked
NIH PubChem PUG-View	Exact match	2026-08-31

A recorded no-match is useful evidence that the source was checked; it is not a claim that the substance does not exist elsewhere.

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 TELMESTEINE

INCI name

TELMESTEINE

Description

3,4-Thiazolidinedicarboxylic acid, 3-ethyl ester, (R)-

Record provenance

Inventory reference: 38541
Imported identity: TELMESTEINE
Source update: 15/10/2010

European Commission CosIng source notes

Annex records for TELMESTEINE

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Key data

CAS

122946-43-4

—

Restriction

—

Function

ANTIOXIDANT: Inhibiting reactions promoted by oxygen, thus avoiding oxidation and rancidity.

Official EU ingredient-name evidence

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

#28465 · TELMESTEINE

Ingredients with overlapping formulation functions

TAXUS MEDIA MERISTEM CELL CULTURE CONDITIONED MEDIAANTIMICROBIAL; ANTIOXIDANT; ANTI-SEBUM; SKIN CONDITIONING - MISCELLANEOUS

TAXUS MEDIA/TAXUS CUSPIDATA/TAXUS BREVIFOLIA/TAXUS BACCATA/TAXUS CANADENSIS MER…ANTIMICROBIAL, ANTIOXIDANT, SKIN CONDITIONING - MISCELLANEOUS

TBHQANTIOXIDANT, FRAGRANCE, PERFUMING

TELOPEA SPECIOSISSIMA FLOWER/LEAF EXTRACTANTIOXIDANT, BLEACHING, HUMECTANT, SKIN CONDITIONING, SKIN PROTECTING

TERMINALIA FERDINANDIANA FRUIT EXTRACTANTIOXIDANT, BLEACHING

TERMINALIA FERDINANDIANA FRUIT POWDERANTIOXIDANT

TERMINALIA FERDINANDIANA SEED OILANTIOXIDANT, HAIR CONDITIONING, HUMECTANT, SKIN CONDITIONING - EMOLLIENT, SKIN PROTECTING

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 TELMESTEINE appears in the CosIng inventory

The CosIng inventory lists TELMESTEINE 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.

TELMESTEINE 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

TELMESTEINE 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, TELMESTEINE carries the following function designation(s):

ANTIOXIDANT

CAS 122946-43-4 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 TELMESTEINE

This page reproduces the CosIng inventory entry for TELMESTEINE 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 TELMESTEINE 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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Tools & next steps

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