Is CROTONIC ACID safe to use in EU cosmetics?

CROTONIC ACID 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 3724-65-0?

CAS 3724-65-0 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.

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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 7539515/10/2010

CROTONIC ACID

2-Butenoic acid

CROTONIC ACID 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 3724-65-0

CAS 3724-65-0PubChem CID 637090

Crotonic Acid

Crotonic acid appears as a white crystalline solid. Shipped as either a solid or liquid. Soluble in water and less dense than water. Corrosive to metals and tissue. — CAMEO Chemicals

IUPAC name: (E)-but-2-enoic acid

Molecular formula: C4H6O2
Molecular weight: 86.09 g/mol
Exact mass: 86.036779430 Da
XLogP3: 0.7
Topological polar surface area: 37.3 Å²
Hydrogen-bond donors: 1
Hydrogen-bond acceptors: 2
Covalent units: 1
Defined stereocentres: 0

Also known as

trans-2-Butenoic acid3-Methylacrylic acid(2E)-but-2-enoic acidbeta-Methylacrylic acidalpha-Butenoic acidalpha-Crotonic acidSolid crotonic acidbeta-Methacrylic acid

16 more reported names

Kyselina krotonovaAcrylic acid, 3-methyl-2E-butenoic acidYW5WZZ4O5QNSC-8751FEMA NO. 3908CHEBI:41131NSC-206946RefChem:919215223-077-4107-93-7trans-Crotonic acid(E)-2-Butenoic acid(E)-Crotonic acidBUTENOIC ACID2-butenoic acid, (2E)-

Open full PubChem record PubChem annotations 3D structure image

External database identifiers

ChEBI:CHEBI:17217
ChEBI:CHEBI:41131
ChEMBL:CHEMBL1213528
EPA DTXSID:DTXSID30880973
PubMed:10246

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 CROTONIC ACID

INCI name

CROTONIC ACID

Description

2-Butenoic acid

Record provenance

Inventory reference: 75395
Imported identity: CROTONIC ACID
Source update: 15/10/2010

European Commission CosIng source notes

Annex records for CROTONIC ACID

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Key data

CAS

3724-65-0

223-077-4

Restriction

—

Function

FRAGRANCE: Imparting an odour or taste. Creating a perceivable pleasant smell and/or masking a bad smell.
LIGHT STABILIZER: Protecting the cosmetic product from deterioration effects of light.

Official EU ingredient-name evidence

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

#7635 · CROTONIC ACID

Ingredients with overlapping formulation functions

CHOLESTEROL/HDI/PULLULAN COPOLYMEREMULSION STABILISING, HUMECTANT, LIGHT STABILIZER, SURFACTANT - EMULSIFYING, VISCOSITY CONTROLLING

COCONUT ALCOHOLEMULSION STABILISING, LIGHT STABILIZER, SKIN CONDITIONING - EMOLLIENT, SURFACTANT - CLEANSING, SURF…

CORN STARCH/ACRYLAMIDE/SODIUM ACRYLATE COPOLYMERANTISTATIC, FILM FORMING, HAIR CONDITIONING, HAIR FIXING, LIGHT STABILIZER

CRESYL METHOXYCINNAMATELIGHT STABILIZER; UV ABSORBER

DIETHYLAMINO HYDROXYBENZOYL HEXYL BENZOATELIGHT STABILIZER, UV ABSORBER, UV FILTER

DIETHYLAMINO HYDROXYBENZOYL MALEIMIDOETHYLAMIDOETHYL BENZOATELIGHT STABILIZER

DIETHYLAMINOMETHYLCOUMARINLIGHT STABILIZER

DIETHYLENE GLYCOL/DIMER DILINOLEIC ACID COPOLYMERFILM FORMING, HAIR CONDITIONING, LIGHT STABILIZER, SKIN CONDITIONING

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 CROTONIC ACID appears in the CosIng inventory

The CosIng inventory lists CROTONIC ACID 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.

CROTONIC ACID 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

CROTONIC ACID 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, CROTONIC ACID carries the following function designation(s):

CAS 3724-65-0 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 CROTONIC ACID

This page reproduces the CosIng inventory entry for CROTONIC ACID 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 CROTONIC ACID 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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