Why does CAS 6728-26-3 appear in more than one EU cosmetic annex?

A substance identified by CAS 6728-26-3 may appear in multiple EU cosmetic regulation annexes when it is subject to different conditions in different contexts — for example, restricted under Annex III with specific conditions, while also appearing in Annex IV as an approved colorant under separate entry conditions. Each entry must be reviewed individually.

How do I check if my formula contains a substance with CAS 6728-26-3?

Use the INCI Checker on CosIng Checker with INCI names, CAS numbers or EC numbers. Paste CAS 6728-26-3 to screen it directly, then review every linked annex record and supplier document.

CAS 1 record

CAS 6728-26-3

Q: How do I use CAS 6728-26-3 for compliance screening?

Cross-reference CAS 6728-26-3 against your raw material specification sheets and CoA documents. When it appears in Annex II, verify absence. When it appears in Annex III, verify that concentration limits and product type conditions are met. All annex entries sharing this CAS number are listed on this page.

CAS 6728-26-3 matches 1 EU annex record across Annex II–VI of Regulation 1223/2009.

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Chemical identity and properties

PubChem 2D chemical structure for CAS 6728-26-3

CAS 6728-26-3PubChem CID 5281168

trans-2-Hexenal

(2E)-hexenal is a 2-hexenal in which the olefinic double bond has E configuration. It occurs naturally in a wide range of fruits, vegetables, and spices. It has a role as an antibacterial agent, a flavouring agent and a plant metabolite. — ChEBI

IUPAC name: (E)-hex-2-enal

Molecular formula: C6H10O
Molecular weight: 98.14 g/mol
Exact mass: 98.073164938 Da
XLogP3: 1.5
Topological polar surface area: 17.1 Å²
Hydrogen-bond donors: 0
Hydrogen-bond acceptors: 1
Covalent units: 1
Defined stereocentres: 0

Also known as

(E)-2-HEXENAL2-trans-Hexenal2-Hexenal, (2E)-FEMA No. 256069JX3AIR1IRefChem:1100222229-778-12-HEXENAL

16 more reported names

Hex-2-enalLeaf aldehydetrans-2-Hexen-1-al505-57-7trans-Hex-2-enalbeta-Propyl acrolein2-Hexenal, (E)-Hexylenic aldehyde(2E)-2-HexenalHex-2-en-1-albeta-Propylacrolein(2E)-hex-2-enal3-propyl acrolein(2e)-hexenalalpha,beta-Hexylenaldehyde3-Propylacrolein

Open full PubChem record PubChem annotations 3D structure image

External database identifiers

ChEBI:CHEBI:19591
ChEBI:CHEBI:28913
ChEMBL:CHEMBL2228570
EPA DTXSID:DTXSID1041425
PubMed:21515296
PubMed:21329684
PubMed:21256123
PubMed:20491607
PubMed:19103229
PubMed:18845131
PubMed:17192441
PubMed:11524419
PubMed:11306073
PubMed:11306050
PubMed:10626223
PubMed:9890881

Retrieved from NIH PubChem on 2026-09-02 by checksum-valid CAS matching. Chemical properties do not replace the regulatory decision on this page.

Records for CAS 6728-26-3

1 total

Annex

III

Entry

166

TRANS-2-HEXENAL

trans-2-hexenal

(a) Oral products (b) Other products

229-778-1

Max concentration

How CAS 6728-26-3 is used on this site

CAS 6728-26-3 is the Chemical Abstracts Service identifier used to pin this page to a specific substance. In the current dataset, 1 EU annex record shares this identifier, which helps you cross-check whether the same substance appears under one regulatory context or several.

Use this page when a supplier specification, SDS or raw-material dossier gives you CAS 6728-26-3 and you need to see every linked Annex II–VI record in one place. The entry cards above are the quickest route to concentration limits, warnings, annex placement and product-type conditions.

Frequently asked questions

A substance identified by CAS 6728-26-3 may appear in multiple EU cosmetic regulation annexes when it is subject to different conditions in different contexts. For example, a substance might be restricted under Annex III with specific conditions, and the same CAS might also appear in Annex IV as an approved colorant under separate entry conditions. Each entry must be reviewed individually.

Cross-reference the CAS number against your raw material specification sheets and CoA documents. When a CAS appears in Annex II, verify absence. When it appears in Annex III, verify that concentration limits and product type conditions are met in your formulation. All annex entries sharing this CAS number are listed above.

A CAS number is assigned by the Chemical Abstracts Service (USA) and is globally recognised. An EC number is a European Commission identifier from inventories such as EINECS, ELINCS or the NLP list. Both identifiers may appear in EU cosmetic annex entries. Some substances have both, some have only one, and some older entries may have neither.

The INCI Checker accepts ingredient names, CAS numbers and EC numbers. Check this CAS number directly, then verify the result against supplier specification sheets and every linked annex condition.

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Tools & next steps

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