What does the restriction note for POTASSIUM THIOGLYCOLATE mean?

The restriction field for POTASSIUM THIOGLYCOLATE reads: III/2a. This is the restriction note from the CosIng inventory. For authoritative conditions and limits, always refer to the linked annex entries.

What other records share CAS 34452-51-2?

CAS 34452-51-2 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 POTASSIUM THIOGLYCOLATE?

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 3703515/10/2010

POTASSIUM THIOGLYCOLATE

Potassium mercaptoacetate

POTASSIUM THIOGLYCOLATE is linked to 1 EU annex record on this page. Inventory note: III/2a.

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Regulatory evidence by market

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Market	Evidence status	Records	Source language
European Union	Evidence linked Restricted entry found Open this evidence	1	English and EU languages
Great Britain	Source mapped Official source mapped; ingredient rule not imported	0	English
Canada	Source mapped Official source mapped; ingredient rule not imported	0	English and French
New Zealand	Source mapped Official source mapped; ingredient rule not imported	0	English
ASEAN	Source mapped Official source mapped; ingredient rule not imported	0	English and national languages
China	Source mapped Official source mapped; ingredient rule not imported	0	Chinese with selected English material
Japan	Source mapped Official source mapped; ingredient rule not imported	0	Japanese; official English translation available
South Korea	Source mapped Official source mapped; ingredient rule not imported	0	Korean with some English names
United States	Source mapped Official source mapped; ingredient rule not imported	0	English
Australia	Source mapped Official source mapped; ingredient rule not imported	0	English
Brazil	Source mapped Official source mapped; ingredient rule not imported	0	Portuguese with INCI crosswalks
India	Source mapped Official source mapped; ingredient rule not imported	0	English and Hindi
Saudi Arabia	Source mapped Official source mapped; ingredient rule not imported	0	Arabic and English

Chemical identity and properties

PubChem 2D chemical structure for CAS 34452-51-2

CAS 34452-51-2PubChem CID 23688957

Potassium Thioglycolate

Based on the available data, the CIR Expert Panel concluded that ... Potassium Thioglycolate is safe for use in hair straighteners, permanent waves, tonics, dressings, and so forth, wave sets, other non-coloring hair products, and hair dyes and colors, as described in this safety assessment, at concentrations up to 15.2% (as Thioglycolic Acid). Hairdressers should avoid skin contact and minimize consumer skin exposure. Potassium Thioglycolate in depilatories is safe when formulated to be non-irritating under conditions of recommended use. — Cosmetic Ingredient Review (CIR)

IUPAC name: potassium 2-sulfanylacetate

Molecular formula: C2H3KO2S
Molecular weight: 130.21 g/mol
Exact mass: 129.94908199 Da
Topological polar surface area: 41.1 Å²
Hydrogen-bond donors: 1
Hydrogen-bond acceptors: 3
Covalent units: 2
Defined stereocentres: 0

Also known as

Potassium 2-mercaptoacetateAcetic acid, mercapto-, monopotassium saltUNII-XP5WZO5W6HXP5WZO5W6HEINECS 252-038-4Acetic acid, 2-mercapto-, potassium salt (1:1)EC 252-038-4Mercaptoacetic acid, monopotassium salt

12 more reported names

RefChem:175626POTASSIUM THIOGLYCOLATE [INCI]252-038-4potassium;2-sulfanylacetatePotassium mercaptoacetatepotassium sulfanylacetatepotassium,2-sulfanylacetatePotassium2-mercaptoacetateC2H3KO2SHYTYHTSMCRDHIM-UHFFFAOYSA-MDB-371697Mercaptoacetic acid potassium, 40 to 44% aqueous solution

Open full PubChem record PubChem annotations 3D structure image

External database identifiers

EPA DTXSID:DTXSID30885589

Retrieved from NIH PubChem on 2026-09-02 by checksum-valid CAS matching. Chemical properties do not replace the regulatory decision on this page.

Inventory details for POTASSIUM THIOGLYCOLATE

INCI name

POTASSIUM THIOGLYCOLATE

Description

Potassium mercaptoacetate

Record provenance

Inventory reference: 37035
Imported identity: POTASSIUM THIOGLYCOLATE
Source update: 15/10/2010

European Commission CosIng source notes

Annex records for POTASSIUM THIOGLYCOLATE

Annex III Restriction reference

Entry 2a

THIOGLYCOLIC ACID

CAS: 68-11-1

EC: 200-677-4

Key data

CAS

34452-51-2

252-038-4

Restriction

III/2a

Function

DEPILATORY: Breaking down the mechanical strength of hair fibers so that they can be removed by mild scraping/rubbing.
HAIR WAVING OR STRAIGHTENING: Modifying the chemical structure of the hair, allowing it to be set in the style required (permanent waves or hair straightening).

Official EU ingredient-name evidence

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

#22779 · POTASSIUM THIOGLYCOLATE

Ingredients with overlapping formulation functions

PHENOL/STYRENE/METHYLSTYRENE COPOLYMERDEPILATORY

PINEAPPLE FRUIT EXTRACT BETA-GLUCANDEPILATORY, SKIN CONDITIONING

POLYTERPENEDEPILATORY

POTASSIUM SULFIDEDEPILATORY

PROPANEDIOL ROSINATESDEPILATORY, FILM FORMING

ROSIN GLYCERIDESANTIMICROBIAL; DEPILATORY; FILM FORMING

ROSIN/FORMALDEHYDE COPOLYMERDEPILATORY

SODIUM SULFIDEDEPILATORY

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 POTASSIUM THIOGLYCOLATE appears in the CosIng inventory

The CosIng inventory lists POTASSIUM THIOGLYCOLATE as a cosmetic ingredient and this page links it to 1 annex record. The inventory entry captures names and identifiers, while the annex record shows where the substance is prohibited, restricted or positively listed in EU cosmetics law.

POTASSIUM THIOGLYCOLATE is also tagged with 2 cosmetic functions 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

POTASSIUM THIOGLYCOLATE appears in the EU CosIng inventory and has linked annex records. Check the annex records above for applicable restrictions, concentration limits and conditions of use. Annex II listing means prohibited; Annex III means restricted; Annexes IV, V and VI mean permitted under specified conditions.

The restriction field for POTASSIUM THIOGLYCOLATE reads: "III/2a". This is the restriction note recorded in the CosIng inventory for this ingredient. For authoritative conditions and limits, always refer to the linked annex entries above.

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

CAS 34452-51-2 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 POTASSIUM THIOGLYCOLATE

This page combines the CosIng inventory entry for POTASSIUM THIOGLYCOLATE with 1 linked Annex II–VI record from the local dataset built from public European Commission cosmetic ingredient materials.

Use this inventory page to research POTASSIUM THIOGLYCOLATE 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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