Why does CAS 51-55-8 appear in more than one EU cosmetic annex?

A substance identified by CAS 51-55-8 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 51-55-8?

Use the INCI Checker on CosIng Checker with INCI names, CAS numbers or EC numbers. Paste CAS 51-55-8 to screen it directly, then review every linked annex record and supplier document.

CAS 1 record

CAS 51-55-8

Q: How do I use CAS 51-55-8 for compliance screening?

Cross-reference CAS 51-55-8 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 51-55-8 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 51-55-8

CAS 51-55-8PubChem CID 174174

Npc209773

Atropine is a racemate composed of equimolar concentrations of (S)- and (R)-atropine. It is obtained from deadly nightshade (Atropa belladonna) and other plants of the family Solanaceae. It has a role as an antidote to sarin poisoning, a oneirogen, a bronchodilator agent, an anti-arrhythmia drug, a muscarinic antagonist, a parasympatholytic, a mydriatic agent, an anaesthesia adjuvant and a plant metabolite. It contains a (S)-atropine and a (R)-atropine. — ChEBI

IUPAC name: [(1S,5R)-8-methyl-8-azabicyclo[3.2.1]octan-3-yl] 3-hydroxy-2-phenylpropanoate

Molecular formula: C17H23NO3
Molecular weight: 289.4 g/mol
Exact mass: 289.16779360 Da
XLogP3: 1.8
Topological polar surface area: 49.8 Å²
Hydrogen-bond donors: 1
Hydrogen-bond acceptors: 4
Covalent units: 1
Defined stereocentres: 2

Also known as

RefChem:1092872ATROPINEdl-HyoscyamineAtropenAtropinTropine tropatedl-TropyltropateAtropinol

16 more reported names

EyesulesIsopto-atropineTroyl tropateAtropinaAtropin-flexiolen(+,-)-Tropyl tropateAtropin [German]Atropina [Italian]hyoscyamine(+/-)-Atropine(+-)-hyoscyamineTropine, tropate (ester)(+-)-atropineTropic acid, ester with tropine(+/-)-HyoscyamineCCRIS 3080

Open full PubChem record PubChem annotations 3D structure image

External database identifiers

ChEBI:CHEBI:16684
ChEBI:CHEBI:78734
ChEMBL:CHEMBL254656
ChEMBL:CHEMBL475124
ChEMBL:CHEMBL517712
EPA DTXSID:DTXSID4020113
EPA DTXSID:DTXSID601141720
PubMed:29860464
PubMed:27085897
PubMed:23091500
PubMed:23088672
PubMed:23087466
PubMed:23087463
PubMed:23075712
PubMed:23057004
PubMed:23056631
PubMed:23055982
PubMed:23037131
PubMed:23029843

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

Records for CAS 51-55-8

1 total

Annex

Entry

Atropine, its salts and derivatives

200-104-8

How CAS 51-55-8 is used on this site

CAS 51-55-8 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 51-55-8 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 51-55-8 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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