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ProhibitedOfficial guidanceCAOriginal is EnglishOfficial-source import checked

3-Imidazol-4-ylacrylic acid and its ethyl ester

Canada Hotlist: 3-Imidazol-4-ylacrylic acid and its ethyl ester

Health Canada lists this ingredient as prohibited for use in cosmetic products.

All Canada recordsOpen ingredient profileCompare all marketsOpen official source

Regulatory decision and full conditions

Status
Prohibited
Legal role
Official guidance
Regulatory summary
Health Canada lists this ingredient as prohibited for use in cosmetic products.
Conditions and restrictions
Synonyms or related compounds: Urocanic acid; ethyl urocanate

Substance identity

Official source name
3-Imidazol-4-ylacrylic acid and its ethyl ester
CAS
104-98-3; 27538-35-8
EC
Not supplied in this source row
Identity mapping
Exact CAS: 104-98-3
Linked ingredient
UROCANIC ACID
Search this identity across the siteCAS 104-98-3CAS 27538-35-8

Linked CosIng identity data

Names and aliases

UROCANIC ACID

CosIng description: 2-Propenoic acid, 3-(1H-imidazol-4-yl)-

EU inventory restriction note: II/418

Recorded cosmetic function: UV ABSORBER

Function pages:UV ABSORBER

View the complete ingredient profile

Cross-market snapshot for this identity

Exact linked records currently present in this site. An absent market means no imported exact match, not permission to use the substance.

10 market datasets
PubChem 2D chemical structure for CAS 104-98-3
CAS 104-98-3PubChem CID 736715

Verified chemistry for CAS 104-98-3

Urocanic Acid

IUPAC name
(E)-3-(1H-imidazol-5-yl)prop-2-enoic acid
Molecular formula
C6H6N2O2
Molecular weight
138.12 g/mol
Exact mass
138.042927438 Da
Monoisotopic mass
138.042927438 Da
XLogP3
0.0
Topological polar surface area
66.0 Ų
Molecular complexity
156.0
Formal charge
0
Hydrogen-bond donors
2
Hydrogen-bond acceptors
3
Rotatable bonds
2
Heavy atoms
10
Covalent units
1

Names and synonyms reported to PubChem

Urocaninic acid(2E)-3-(1H-imidazol-4-yl)prop-2-enoic acid3-(1H-Imidazol-4-yl)-2-propenoic acid2-Propenoic acid, 3-(1H-imidazol-4-yl)-G8D26XJJ3BNSC-663572-Propenoic acid, 3-(1H-imidazol-4-yl)-, (E)-CHEBI:27248
16 more reported names
Acid, UrocanicGlyoxalinylacrylic AcidAcid, GlyoxalinylacrylicRefChem:901492203-258-43-(1H-imidazol-5-yl)prop-2-enoic acidtrans-Urocanic acid4-imidazoleacrylic acid3465-72-3urocanateimidazoleacrylic acid(E)-3-(1H-imidazol-5-yl)acrylic acid5-Imidazoleacrylic acid(2E)-3-(1H-IMIDAZOL-4-YL)ACRYLIC ACID(E)-3-(4-Imidazolyl)acrylic acid3-Imidazol-4-ylacrylic acid
Open full PubChem recordSafety and hazards at PubChemPubChem annotationsChemical classifications3D structure image
External database identifiers
Advanced structure statistics
Defined atom stereocentres
0
Undefined atom stereocentres
0
Defined bond stereocentres
1
Undefined bond stereocentres
0
3D pharmacophore features
6
3D rings
1
3D hydrophobes
0
3D acceptor features
2
3D donor features
1
3D anionic centres
1
3D cationic centres
1
3D conformers
6
Effective 3D rotors
2.0
Machine-readable structure identifiers
SMILES
C1=C(NC=N1)/C=C/C(=O)O
InChI
InChI=1S/C6H6N2O2/c9-6(10)2-1-5-3-7-4-8-5/h1-4H,(H,7,8)(H,9,10)/b2-1+
InChIKey
LOIYMIARKYCTBW-OWOJBTEDSA-N

Evidence from additional scientific databases

NIH PubChem PUG-View
Exact identifier match736715

Attributed physical-property, hazard, environmental and use annotations.

  • Cosmetic Ingredient Review Conclusion: The safety of this ingredient has not been documented and substantiated. The CIR Expert Panel cannot conclude whether Urocanic Acid is safe for use in cosmetic products until such time as the appropriate safety data have been obtained and evaluated. Source: Cosmetic Ingredient Review (CIR)
  • Cosmetic Ingredient Review Finding(s): Ingredients for which the data are insufficient and their use in cosmetics is not supported Source: Cosmetic Ingredient Review (CIR)

Mapped by: Existing checksum-valid CAS to unique PubChem CID match. Retrieved: 2026-08-31. Open source record

Scientific classifications and hazard annotations provide context and do not replace the market-specific regulatory decision shown above.

Additional source coverage and match status
SourceResultChecked
EMBL-EBI ChEBINeeds review2026-08-31
NIH PubChem PUG-ViewExact match2026-08-31

A recorded no-match is useful evidence that the source was checked; it is not a claim that the substance does not exist elsewhere.

Retrieved from NIH PubChem on 2026-08-31 by checksum-valid CAS matching. Chemical properties do not replace the regulatory decision on this page.

PubChem 2D chemical structure for CAS 27538-35-8
CAS 27538-35-8PubChem CID 6365633

Verified chemistry for CAS 27538-35-8

Ethyl urocanate

IUPAC name
ethyl (E)-3-(1H-imidazol-5-yl)prop-2-enoate
Molecular formula
C8H10N2O2
Molecular weight
166.18 g/mol
Exact mass
166.074227566 Da
Monoisotopic mass
166.074227566 Da
XLogP3
0.7
Topological polar surface area
55.0 Ų
Molecular complexity
180.0
Formal charge
0
Hydrogen-bond donors
1
Hydrogen-bond acceptors
3
Rotatable bonds
4
Heavy atoms
12
Covalent units
1

Names and synonyms reported to PubChem

Parasonarl Mark II(E)-Urocanic acid ethyl esterUNII-GS4W88OP01GS4W88OP01EINECS 248-515-1Ethyl (E)-3-(1H-imidazol-4-yl)-2-propenoate2-Propenoic acid, 3-(1H-imidazol-4-yl)-, ethyl ester, (2E)-2-Propenoic acid, 3-(1H-imidazol-4-yl)-, ethyl ester, (E)-
16 more reported names
2-Propenoic acid, 3-(1H-imidazol-5-yl)-, ethyl ester, (2E)-3-(1H-Imidazol-4-yl)-2-propenoic acid, ethyl ester2-Propenoic acid, 3-(1H-imidazol-4-yl)-, ethyl esterRefChem:139070ETHYL UROCANATE [INCI](e)-3-(1h-imidazol-4-yl)-2-propenoic acid ethyl esterEthyl (2E)-3-(1H-imidazol-4-yl)prop-2-enoateethyl (2E)-3-(1H-imidazol-5-yl)prop-2-enoateEthyl 3-(1H-imidazol-4-yl)acrylateHPMLGOFBKNGJAM-ONEGZZNKSA-NEthyl (E)-3-(4-Imidazolyl)acrylateAS-48227(E)-ethyl 3-(1H-imidazol-4-yl)acrylateethyl (E)-3-(1H-imidazol-5-yl)acrylateEN300-1455951Ethyl(2E)-3-(1H-imidazol-4-yl)prop-2-enoate
Open full PubChem recordSafety and hazards at PubChemPubChem annotationsChemical classifications3D structure image
Advanced structure statistics
Defined atom stereocentres
0
Undefined atom stereocentres
0
Defined bond stereocentres
1
Undefined bond stereocentres
0
3D pharmacophore features
4
3D rings
1
3D hydrophobes
0
3D acceptor features
1
3D donor features
1
3D anionic centres
0
3D cationic centres
1
3D conformers
10
Effective 3D rotors
4.0
Machine-readable structure identifiers
SMILES
CCOC(=O)/C=C/C1=CN=CN1
InChI
InChI=1S/C8H10N2O2/c1-2-12-8(11)4-3-7-5-9-6-10-7/h3-6H,2H2,1H3,(H,9,10)/b4-3+
InChIKey
HPMLGOFBKNGJAM-ONEGZZNKSA-N

Retrieved from NIH PubChem on 2026-08-31 by checksum-valid CAS matching. Chemical properties do not replace the regulatory decision on this page.

Official source and provenance

Registered source
Health Canada Cosmetic Ingredient Hotlist
Source reference
Hotlist prohibited entry 27
Source record ID
prohibited:27
Source version
Health Canada Hotlist 2025-08-13
Source language
English
Translation status
Original is English
Source updated
2025-08-13
Snapshot checked
2026-08-30 04:07 UTC
Validation method
strict HTML tables t1=490 and t2=90
SHA-256
8b52ff573d08373ee90121f6a701b3607e4a3d6fc748a7d56171eb53510af91a

Registered dataset notes

Dataset coverage
Administrative prohibitions, restrictions, conditions and warning requirements
Authority note
Official Health Canada compliance indicator; not a complete safety clearance
Inspect the exact official sourceRegulator guidance

How this record fits the market dataset

580
current Canada records
490
records marked Prohibited
580
records from this source version
516
market records with CAS identity

Status distribution

Prohibited: 490Restricted: 90

Condition text is present on 172 of 580 current records. An empty condition field is interpreted according to the record type above; it is never converted into an unrestricted-use claim.

Canada market context

Complete Hotlist snapshot

Coverage version: Health Canada Cosmetic Ingredient Hotlist, 13 August 2025

All prohibited and restricted Hotlist entries, including conditions and warning requirements published in the official list.

Verification checklist

  1. Search English/French names and CAS identifiers.
  2. Apply every restriction, concentration and label warning.
  3. Check Food and Drugs Act/Cosmetic Regulations requirements.
  4. Recheck the current Hotlist before notification or sale.

Official market sources

Verification workflow and record completeness

Before using this result in a compliance decision

  1. Confirm that “3-Imidazol-4-ylacrylic acid and its ethyl ester” and every CAS/EC identifier refer to the material in your supplier specification.
  2. Search English/French names and CAS identifiers.
  3. Apply every restriction, concentration and label warning.
  4. Check Food and Drugs Act/Cosmetic Regulations requirements.
  5. Recheck the current Hotlist before notification or sale.
  6. Document the source version and recheck the regulator before manufacture, notification or market placement.

Fields available in this record

  • Official substance nameAvailable
  • CASAvailable
  • ECNot supplied
  • Separate condition textAvailable
  • Effective dateNot supplied
  • Snapshot hash and methodAvailable

Questions this page answers

This official record identifies the substance as prohibited for cosmetic use in the stated market scope. Do not rely on a formulation containing this identity until the cited source, effective date and exact substance match have been verified.

A prohibition entry may contain no separate condition text because the regulatory outcome is the prohibition itself. The Hotlist is an administrative compliance tool, not an exhaustive safety approval list.

The record cites Hotlist prohibited entry 27, source version Health Canada Hotlist 2025-08-13. Open the official source.

No. CAS helps resolve identity, but jurisdictions can classify the same substance differently and can apply different product scopes, limits, warnings and transition dates.

Stable citation

3-Imidazol-4-ylacrylic acid and its ethyl ester. Hotlist prohibited entry 27. Canada. Source version Health Canada Hotlist 2025-08-13. CosIng Checker regulatory record: https://cosingchecker.com/regulations/ca/records/27/

Cite the regulator as the legal authority. This page is a structured evidence index and verification aid, not a substitute for the official text or professional legal assessment.

Interpretation and limits for Canada

This official record identifies the substance as prohibited for cosmetic use in the stated market scope.

Do not rely on a formulation containing this identity until the cited source, effective date and exact substance match have been verified.

How to interpret the legal role

The authority uses this source as compliance guidance; the underlying legislation remains controlling.

Evidence on this page

  • Recorded outcome: Prohibited
  • Legal role: Official guidance
  • Source version: Health Canada Hotlist 2025-08-13

What it does not prove

The Hotlist is an administrative compliance tool, not an exhaustive safety approval list.

Further authoritative substance research

These sources can add identity, safety, exposure or hazard context. A link is not evidence that the database contains this exact substance, and none of these sources overrides the market decision above.

Cosmetic Ingredient Review safety assessments

Expert Panel conclusions, assessed ingredient groups, use conditions, dates and report documents

Independent expert review considered by FDA; not a government approval or binding market rule

Research this identity at the source

FDA Global Substance Registration System

UNII identifiers, preferred names, substance types, codes and public substance relationships

Identity registry only; UNII availability does not imply FDA review or approval

Research this identity at the source

ILO/WHO International Chemical Safety Cards

Hazards, symptoms, first aid, storage, incompatibilities and physical properties for covered chemicals

International occupational chemical-safety reference; not cosmetic-use approval

Research this identity at the source

Japan NITE-CHRIP

Chemical identity, Japanese and foreign legal lists, GHS hazards and exposure-related information

Chemical-management evidence; cosmetic status remains governed by the applicable MHLW standard and market rules

Research this identity at the source

NIOSH Pocket Guide to Chemical Hazards

REL, PEL, IDLH, properties, exposure routes, symptoms, target organs, first aid and measurement methods for covered workplace chemicals

US occupational-health guidance and limits; not a cosmetic ingredient decision

Research this identity at the source

OECD eChemPortal

Gateway to authority-owned physical-property, fate, ecotoxicity, toxicity, exposure and GHS records

Discovery gateway; each linked authority remains responsible for its data

Research this identity at the source

US EPA CompTox CTX APIs

API key required for import

DTXSID identity, experimental and predicted properties, toxicity, bioactivity, exposure and environmental data

Scientific and computational evidence; predictions must remain labelled and do not determine cosmetic legality

Research this identity at the source