Why does CAS 97-18-7 appear in more than one EU cosmetic annex?

A substance identified by CAS 97-18-7 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 97-18-7?

Use the INCI Checker on CosIng Checker with INCI names, CAS numbers or EC numbers. Paste CAS 97-18-7 to screen it directly, then review every linked annex record and supplier document.

CAS 1 record

CAS 97-18-7

Q: How do I use CAS 97-18-7 for compliance screening?

Cross-reference CAS 97-18-7 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 97-18-7 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 97-18-7

CAS 97-18-7PubChem CID 2406

Bithionol

Bithionol is an aryl sulfide that is diphenyl sulfide in which each phenyl group is substituted at position 2 by hydroxy and at positions 3 and 5 by chlorine. A fungicide and anthelmintic, it was used in various topical drug products for the treatment of liver flukes, but withdrawn after being shown to be a potent photosensitizer with the potential to cause serious skin disorders. It has a role as an antiplatyhelmintic drug and an antifungal agrochemical. It is a dichlorobenzene, a polyphenol, an aryl sulfide, an organochlorine pesticide, a bridged diphenyl fungicide and a bridged diphenyl antifungal drug. — ChEBI

IUPAC name: 2,4-dichloro-6-(3,5-dichloro-2-hydroxyphenyl)sulfanylphenol

Molecular formula: C12H6Cl4O2S
Molecular weight: 356.0 g/mol
Exact mass: 355.881311 Da
XLogP3: 5.8
Topological polar surface area: 65.8 Å²
Hydrogen-bond donors: 2
Hydrogen-bond acceptors: 3
Covalent units: 1
Defined stereocentres: 0

Also known as

BithinLorothidol2,2'-Thiobis(4,6-dichlorophenol)ActamerBitionolBidiphenBisoxyphenLorothiodol

16 more reported names

Bithionol sulfideBithionolateNeopellisBitinVancide BLTKhsdUsaf B-222-Hydroxy-3,5-dichlorophenyl sulfideBithionolumBis(2-hydroxy-3,5-dichlorophenyl) sulfideBis(3,5-dichloro-2-hydroxyphenyl) sulfide2,2'-sulfanediylbis(4,6-dichlorophenol)2-Hydroxy-3,5-dichlorophenyl sulphide2,2'-Dihydroxy-3,3',5,5'-tetrachlorodiphenyl sulfideCP 3438NCI-C60628

Open full PubChem record PubChem annotations 3D structure image

External database identifiers

ChEBI:CHEBI:3131
ChEMBL:CHEMBL290106
EPA DTXSID:DTXSID9021342
PubMed:32284327
PubMed:22898086
PubMed:22489155
PubMed:22342964
PubMed:22335786
PubMed:22145034
PubMed:22015988
PubMed:21909440
PubMed:21897666
PubMed:21894072
PubMed:21826158
PubMed:21695247

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 97-18-7

1 total

Annex

Entry

352

Bithionol (INN)

202-565-0

How CAS 97-18-7 is used on this site

CAS 97-18-7 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 97-18-7 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 97-18-7 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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