Why does CAS 96-09-3 appear in more than one EU cosmetic annex?

A substance identified by CAS 96-09-3 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 96-09-3?

Use the INCI Checker on CosIng Checker with INCI names, CAS numbers or EC numbers. Paste CAS 96-09-3 to screen it directly, then review every linked annex record and supplier document.

CAS 1 record

CAS 96-09-3

Q: How do I use CAS 96-09-3 for compliance screening?

Cross-reference CAS 96-09-3 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 96-09-3 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 96-09-3

CAS 96-09-3PubChem CID 7276

Styrene Oxide

Styrene oxide is an epoxide that is oxirane in which one of the hydrogens has been replaced by a phenyl group. It has a role as a human xenobiotic metabolite. It derives from a hydride of a styrene. — ChEBI

IUPAC name: 2-phenyloxirane

Molecular formula: C8H8O
Molecular weight: 120.15 g/mol
Exact mass: 120.057514874 Da
XLogP3: 1.6
Topological polar surface area: 12.5 Å²
Hydrogen-bond donors: 0
Hydrogen-bond acceptors: 1
Covalent units: 1
Defined stereocentres: 0

Also known as

PhenyloxiraneEpoxystyrenePhenylethylene oxide1,2-EpoxyethylbenzeneStyrene epoxideStyryl oxidePhenethylene oxide1-Phenyloxirane

16 more reported names

Styrene 7,8-oxide(Epoxyethyl)benzenePhenyl oxiraneEpoxyethylbenzene1-Phenyl-1,2-epoxyethaneBenzene, (epoxyethyl)-STYRENE-7,8-OXIDE1,2-Epoxy-1-phenylethaneoxirane, 2-phenyl-FenyloxiranEpoxyethyl benzeneNCI-C54977alpha,beta-Epoxystyrene9QH06NGT6OEthane, 1,2-epoxy-1-phenyl-NSC-637

Open full PubChem record PubChem annotations 3D structure image

External database identifiers

ChEBI:CHEBI:17907
ChEMBL:CHEMBL1605493
EPA DTXSID:DTXSID2021286
PubMed:25986970
PubMed:23013537
PubMed:22967603
PubMed:22869611
PubMed:22812696
PubMed:22723965
PubMed:22700535
PubMed:22526330
PubMed:22509344
PubMed:22507543
PubMed:22492963
PubMed:22408390

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 96-09-3

1 total

Annex

Entry

656

(Epoxyethyl)benzene (Styrene oxide)

202-476-7

CMR

How CAS 96-09-3 is used on this site

CAS 96-09-3 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 96-09-3 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 96-09-3 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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