What does Methyl thioglycolate do?

Used in cosmetics as a hair waving or straightening agent. Methyl Thioglycolate is the ester of methyl alcohol and Thioglycolic Acid.

Is Methyl thioglycolate safe?

We haven't assessed a concern score for this ingredient yet. It is listed for cosmetic use in the EU.

beauty
industrial

Methyl thioglycolate

CAS 64807-90-5

Also registered as 3 other CAS numbers

1629585-98-3 · 2787549-47-5 · 2365-48-2

Concern score

Not assessed — no hazard data yet.

Methyl thioglycolate in plain language

What it is: Also known as Acetic acid, 2-MERCAPTO-, methyl ester · Acetic acid, mercapto-, methyl ester · Methyl sulfanylacetate · methyl 2-sulfanylacetate · 2-MERCAPTOACETIC acid methyl ester · Methyl .alpha.-mercaptoacetate
Show all 18 names
Mercaptoacetic acid methyl ester · Methanethiol, methoxy- · Methyl 2-mercaptoacetate · Methyl mercaptoacetate · Methyl α-mercaptoacetate · Methylmercaptoacetate · Methylthioglycolate · Thioglycolic acid methyl ester · Thioglykolsaeure-methylester · Usaf EK-7119 · mercaptoacetate de methyle · mercaptoacetato de metilo
What it does: Used in cosmetics as a hair waving or straightening agent. Methyl Thioglycolate is the ester of methyl alcohol and Thioglycolic Acid.
Hair waving or straightening
Is it a concern?: We haven't assessed a concern score for this ingredient yet. It is listed for cosmetic use in the EU.

Regulation

No restrictions found. Methyl thioglycolate appears in these published regulatory listings.

Recorded in these product areas

Found in consumer products
Industrial

EUCosIngActiveMethyl Thioglycolate is the ester of methyl alcohol and Thioglycolic Acid. It conforms to the formula: Restriction: III/2b
- Methyl Thioglycolate is the ester of methyl alcohol and Thioglycolic Acid. It conforms to the formula: Restriction: III/2bSource →
USEPAcommercial use observedEPA CPDat observed this chemical in 0 composition records across product categories including unclassified products. EPA CPDat classifies this chemical for functional uses including Hair waving or straightening.
- EPA CPDat observed this chemical in 0 composition records across product categories including unclassified products. EPA CPDat classifies this chemical for functional uses including Hair waving or straightening.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 Methyl thioglycolate. 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 Methyl thioglycolate yet. This record is compiled from the published data sources below — registries and regulatory listings, not study findings.

6 data sources

Where this comes from

CosIng
regulatory · updated 2026-09-23
Open →
EPA Chemical and Products Database
exposure · updated 2019-12-20
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

Nothing to weigh for this context yet.

No signal in this context

We have no published hazard signal for this ingredient, so we cannot say how it behaves in this context — that is missing evidence, not a clean result.

Where it has been recorded

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

Named organisations

Typical roles

Hair waving or straightening

See products using Methyl thioglycolate →