beauty
cleaning
industrial

Thioglycolic acid

CAS 7283-42-3 · 70/100 · High conf.

Also registered as 2 other CAS numbers

57755-20-1 · 68-11-1

Concern score

70/100High concern based on regulatory listings.

High confidence

Thioglycolic acid in plain language

What it is: On cosmetic ingredient lists it appears as “Ammonium thioglycolate”.
Also known as Ammonium thioglycolate · Calcium thioglycolate · Calcium thioglycolate hydroxide · Ethanolamine thioglycolate · Magnesium thioglycolate · Potassium thioglycolate
Show all 30 names
Sodium thioglycolate · Strontium thioglycolate · Mercaptoacetic acid · Thioglycollic acid · Thioglycolic acid and its salts · 2-sulfanylacetic acid · Sulfanylacetic acid · 2-Mercaptoacetic acid · 2-Mercaptoethanoic acid · 2-Thioglycolic acid · Acetic acid, 2-mercapto- · Acetic acid, mercapto- · Acide mercaptoacetique · Acide thioglycolique · Glycolic acid, 2-thio- · Glycolic acid, thio- · Kyselina merkaptooctova · Kyselina thioglykolova · Mercaptoessigsaeure · Mercaptoethanoic acid · Thiovanic acid · Usaf CB-35 · acido mercaptoacetico · alpha-Mercaptoacetic acid
What it does: Used in cosmetics as an antioxidant, a depilatory and a hair waving or straightening agent. Thioglycolic Acid is the organic acid.
Antioxidant
Depilatory
Hair waving or straightening
Reducing
Is it a concern?: High concern: no hazard classifications on record. It is restricted in EU cosmetics.

Why it's flagged

Thioglycolic acid and its salts is restricted in cosmetic products under Annex III of the EU Cosmetics Regulation (EC) 1223/2009.

RestrictedEU EC — restricted

The score describes this ingredient's chemical identity — its hazard profile from published classifications and regulatory status — not the safety of any product it appears in.

Regulation

Restrictions first, then routine listings from published regulatory sources.

EU Annex III — restricted
EU restricted in cosmetics

Recorded in these product areas

Found in consumer products
Beauty
Cleaning
Industrial

EUEC
Annex III of EU Cosmetics Regulation (EC) 1223/2009: substances which cosmetic products must not contain except subject to the restrictions laid down. Product types: (a) Hair products (b) Depilatories (c) Hair rinse-off products (d) Products intended for eyelash waving Maximum concentration: (a) (i) 8% (ii) 11% (b) 5% (c) 2% (d) 11% The abovementioned percentages are calculated as thioglycollic acid Other conditions: (a) (i) General use ready for use pH 7 to 9.5 (ii) Professional use ready for use pH 7 to 9.5 (b) ready for use pH 7 to 12.7 (c) ready for use pH 7 to 9.5 (d) ready for use pH 7 to 9,5 Conditions of use and warnings: Conditions of use: (a) (b) (c) (d) Avoid contact with eyes Rinse eyes immediately if product comes into contact with them. (a) (c) (d) Wear suitable gloves Warnings to be printed on the label: (a)(i) (b) (c) Contains thioglycolate Follow the instructions Keep out of reach of children (a)(ii) (d) For professional use only Contains thioglycolate Follow the instructions’
restricted
View source →

EUCosIngActive2 entries
- Thioglycolic Acid is the organic acid that conforms generally to the formula: Restriction: III/2aSource →
- Cosmetics Regulation annex III / ref 2a.Source →
USEPAcommercial use observedEPA CPDat observed this chemical in 42 composition records across product categories including Vehicle, Cleaning products and household care, Personal care. EPA CPDat classifies this chemical for functional uses including Antioxidant, Reducing agent, Depilatory.
- EPA CPDat observed this chemical in 42 composition records across product categories including Vehicle, Cleaning products and household care, Personal care. EPA CPDat classifies this chemical for functional uses including Antioxidant, Reducing agent, Depilatory.Source →
USFDAlisted in openFDA substanceopenFDA substance registry classifies this ingredient as chemical.
- openFDA substance registry classifies this ingredient as chemical.Source →

Expert safety opinions

No expert opinion on file for Thioglycolic acid. These are the independent scientific bodies that assess ingredients like this one; we show an opinion only when a record we hold cites it.

SCCS
EU Scientific Committee on Consumer Safety
No SCCS opinion on file.
CIR
Cosmetic Ingredient Review (US expert panel)
No CIR safety assessment on file.

Evidence & sources

No graded research studies for Thioglycolic acid yet. This record is compiled from the published data sources below — registries and regulatory listings, not study findings.

7 data sources

Where this comes from

CosIng
regulatory · updated 2026-09-23
Open →
EU CosIng Cosmetics Regulation Annexes
regulatory · updated 2020-07-27
Open →
EPA Chemical and Products Database
exposure · updated July 2016
Open →
EPA DSSTox Identifiers
chemistry · updated 2025-12-29
Open →
FDA GSRS UNII
registry · updated 2026-02-26
Open →
openFDA Substance
registry · updated 2026-05-24
Open →
PubChem Live Enrichment
chemistry · updated 2026-05-17
Open →

Suitability

Context-specific fit derived from published classifications and the current ingredient evidence profile.

Fragrance avoidance

No fragrance-linked caution surfaced in the current profile.

Good fit

This ingredient does not currently read as a fragrance-linked driver in the published evidence and hazard profile.

Where it has been recorded

How often EPA CPDat has listed Thioglycolic acid in a product composition. These are source records, not Greenveil catalog products.

Source records

Named organisations

VehicleCleaning products and household carePersonal careRaw materialsLaboratory suppliesSpecialty occupational products

Typical roles

AntioxidantDepilatoryHair waving or straighteningReducing

See products using Thioglycolic acid →

Catalog

Found in these products

Their ingredient lists include Thioglycolic acid; each product's own rating depends on its whole formula, so it is shown on the product page, not here.

See all 37 →Find products without it →

Co-occurrence

Often appears with

Ingredients that frequently appear alongside Thioglycolic acid in the catalog.