- beauty
- industrial
Mercaptopropionic acid
CAS 803635-69-0
Also registered as 3 other CAS numbers
1629856-14-9 · 2018279-94-0 · 107-96-0
Concern score
Not assessed — no hazard data yet.
Mercaptopropionic acid in plain language
Also known as 3-MERCAPTOPROPIONIC acid · 3-Mercaptopropanoic acid · .beta.-thiopropionic acid · 3-Sulfanylpropanoic acid · Deamino cysteine · Mercaptopropionic acid, 3-
Show all 20 names
Propanoic acid, 3-MERCAPTO- · .beta.-mercaptopropanoic acid · .beta.-mercaptopropionic acid · 2-Mercaptoethanecarboxylic acid · 3-MERCAPTOPROPIONSAEURE · 3-Mercaptopropionsaure · 3-Thiopropanoic acid · 3-Thiopropionic acid · 3MPA · Acid, 3-Mercaptopropanoic · Acid, 3-Mercaptopropionic · Acide 3-mercaptopropionique · Propionic acid, 3-mercpato- · Thiohydracrylic acid
Used in cosmetics as a depilatory, a hair waving or straightening agent and a reducing agent.
- Depilatory
- Hair waving or straightening
- Reducing
- Flavouring
- We haven't assessed a concern score for this ingredient yet. It is listed for cosmetic use in the EU.
Regulation
No restrictions found. Mercaptopropionic acid appears in these published regulatory listings.
- Found in consumer products
- Beauty
- Industrial
EUCosIngActiveListed in CosIng inventory for cosmetic use.
- Listed in CosIng inventory for cosmetic use.Source →
USEPAcommercial use observedEPA CPDat observed this chemical in 7 composition records across product categories including Laboratory supplies, Construction, Personal care. EPA CPDat classifies this chemical for functional uses including Reducing agent, Depilatory, Hair waving or straightening.
- EPA CPDat observed this chemical in 7 composition records across product categories including Laboratory supplies, Construction, Personal care. EPA CPDat classifies this chemical for functional uses including Reducing agent, Depilatory, 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 Mercaptopropionic 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 Mercaptopropionic acid yet. This record is compiled from the published data sources below — registries and regulatory listings, not study findings.
Where this comes from
- Open →
CosIng
regulatory · updated 2026-09-23
- Open →
EPA Chemical and Products Database
exposure · updated September 2013
- 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
Reference links (1)
Suitability
Context-specific fit derived from published classifications and the current ingredient evidence profile.
Fragrance avoidance
Nothing to weigh for this context yet.
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 Mercaptopropionic acid in a product composition. These are source records, not Greenveil catalog products.
Source records
7
Named organisations
5
Laboratory suppliesConstructionPersonal care
Typical roles
DepilatoryHair waving or straighteningReducingFlavouring