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Annex II Entry 438 20/10/2010

trans-2-Hexenal diethyl acetal, when used as a fragrance ingredient

trans-2-Hexenal diethyl acetal, when used as a fragrance ingredient is listed in Annex II as a prohibited substance for cosmetic products placed on the EU market.

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Prohibited substance— Annex II, EU Regulation 1223/2009
Entry: 438

Chemical identity and properties

PubChem 2D chemical structure for CAS 67746-30-9
CAS 67746-30-9PubChem CID 5365137

2-Hexenal diethyl acetal, (2E)-

1,1-Diethoxy-2-hexene is an acetal. — ChEBI

IUPAC name
(E)-1,1-diethoxyhex-2-ene
Molecular formula
C10H20O2
Molecular weight
172.26 g/mol
Exact mass
172.146329876 Da
XLogP3
2.6
Topological polar surface area
18.5 Ų
Hydrogen-bond donors
0
Hydrogen-bond acceptors
2
Covalent units
1
Defined stereocentres
0

Also known as

trans-2-Hexen-1-al diethyl acetaltrans-2-Hexenal diethyl acetal2-Hexene, 1,1-diethoxy-, (2E)-1,1-Diethoxy-2-hexene(E)-2-hexenal diethyl acetal1,1-Diethoxy-trans-2-hexenetrans-2-Hexenal diethylacetal2-Hexene, 1,1-diethoxy-, (E)-
16 more reported names
(E)-1,1-Diethoxy-2-hexene(2E)-1,1-DIETHOXYHEX-2-ENE1UMD1RAR3QEINECS 266-989-82-Hexene, 1,1-diethoxy-FEMA NO. 4047LEAFALDEHYDE DIETHYL ACETAL(E)-2-HEXENAL DIETHYL ACETAL [FHFI]RefChem:4728782-Hexenal diethyl acetal, predominantly transtrans-2-Hexen-1-alDiethylAcetal2-Hexenal diethyl acetal, trans(2E)-1,1-Diethoxy-2-hexeneUNII-1UMD1RAR3QLeaf Aldehyde Diethyl Acetal1,1-Diethoxy-(E)-2-Hexene
Open full PubChem recordPubChem annotations3D structure image
External database identifiers

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

Record details

Chemical name

trans-2-Hexenal diethyl acetal, when used as a fragrance ingredient

Regulatory information

Regulation

(EC) 2009/1223

See every entry this act set

SCCS opinions

Key data

CAS
67746-30-9
EC
266-989-8
Annex
II
Entry number
438

Direct matches are limited for this record, so nearby entries from Annex II are shown as well.

What Annex II means for trans-2-Hexenal diethyl acetal, when used as a fragrance ingredient

trans-2-Hexenal diethyl acetal, when used as a fragrance ingredient is listed as a prohibited substance under Annex II of EU Cosmetics Regulation 1223/2009 and must not be intentionally added. Article 17 separately addresses unintended small quantities that are technically unavoidable under good manufacturing practice and compatible with the Article 3 safety requirement.

Formulators must screen their ingredients and raw materials to ensure none contain this substance. Suppliers should provide documentation confirming absence when requested.

The page also surfaces 12 related annex records with overlapping identifiers, annex logic or naming patterns.

Compliance checklist

  • Verify this substance is absent from all raw materials and finished formulations.
  • Request absence confirmation or CoA from raw material suppliers.
  • Document the screening result in the Product Information File (PIF).

Frequently asked questions

Yes. trans-2-Hexenal diethyl acetal, when used as a fragrance ingredient is listed in Annex II of EU Cosmetics Regulation 1223/2009 and is prohibited as an intentionally added cosmetic ingredient. Article 17 provides a narrow exception for unintended small quantities that are technically unavoidable under good manufacturing practice, provided the product remains safe under Article 3.

CAS 67746-30-9 is the unique numerical identifier assigned to trans-2-Hexenal diethyl acetal, when used as a fragrance ingredient by the Chemical Abstracts Service. In cosmetic compliance work, the CAS number is used to cross-reference the substance across regulatory databases, raw material specifications and safety assessment reports. Multiple EU annex entries may share the same CAS number if the same substance appears under different conditions or in different annexes.

Use the INCI Checker tool on this site to paste your full ingredient list (INCI) and scan it against all Annex II–VI entries. The tool highlights any ingredients that match restricted, prohibited or allergen-flagged records. This is useful for rapid compliance screening of finished product formulas or raw material declarations.
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Source note for Annex II record trans-2-Hexenal diethyl acetal, when used as a fragrance ingredient

This page summarizes one Annex II record for trans-2-Hexenal diethyl acetal, when used as a fragrance ingredient from public European Commission cosmetic materials and adds linked inventory or identifier matches when available.

Use this record page to review Annex II conditions for trans-2-Hexenal diethyl acetal, when used as a fragrance ingredient, but confirm any final regulatory decision against the current official annex wording and source files.

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