Why does CAS 155601-30-2 appear in more than one EU cosmetic annex?

A substance identified by CAS 155601-30-2 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 155601-30-2?

Use the INCI Checker on CosIng Checker with INCI names, CAS numbers or EC numbers. Paste CAS 155601-30-2 to screen it directly, then review every linked annex record and supplier document.

CAS 1 record

CAS 155601-30-2

Q: How do I use CAS 155601-30-2 for compliance screening?

Cross-reference CAS 155601-30-2 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 155601-30-2 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 155601-30-2

CAS 155601-30-2PubChem CID 11673148

4,5-Diamino-1-(2-hydroxyethyl)pyrazole sulfate

IUPAC name: 2-(4,5-diaminopyrazol-1-yl)ethanol;sulfuric acid

Molecular formula: C5H12N4O5S
Molecular weight: 240.24 g/mol
Exact mass: 240.05284067 Da
Topological polar surface area: 173.0 Å²
Hydrogen-bond donors: 5
Hydrogen-bond acceptors: 8
Covalent units: 2
Defined stereocentres: 0

Also known as

Colorex WP51H-Pyrazole-1-ethanol, 4,5-diamino-, sulfate (1:1)UNII-04N8KX12N61-(2-Hydroxyethyl)-4,5-diaminopyrazole sulfate4,5-Diamino-1-(2-hydroxyethyl)-1H-pyrazole sulfate04N8KX12N61-Hydroxyethyl 4,5-diamino pyrazole sulfate1H-Pyrazole-1-ethanol, 4,5-diamino-, sulfate (1:1) (salt)

16 more reported names

EC 429-300-3RefChem:964254,5-diamino-1-(2-hydroxyethyl)-pyrazole sulfate1-HYDROXYETHYL 4,5-DIAMINO PYRAZOLE SULFATE [INCI]605-017-24,5-DIAMINO-1-(2-HYDROXYETHYL)PYRAZOLESULPHATEC5H12N4O5S4,5-DIAMINO-1-PYRAZOLEETHANOL SULFATE4,5-Diamino-1-(2-Hydroxyethyl) pyrazole sulfate4,5-Diamino-1-(2-hydroxyethyl)pyrazolesulfate4,5-Diamino-1-(2-hydroxy)ethyl pyrazole sulfate2-(4,5-Diamino-1H-pyrazol-1-yl)ethan-1-ol sulfate1-(2-hydroxyethyl)-1H-pyrazol-4,5-diyldiammoniumsulfate2-(4,5-diamino-1H-pyrazol-1-yl)ethan-1-ol; sulfuric acidAC-8151CS-W003383

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External database identifiers

EPA DTXSID:DTXSID20165928

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 155601-30-2

1 total

Annex

III

Entry

273

1-Hydroxyethyl-4,5- Diamino Pyrazole Sulfate

4,5-Diamino-1-(2- hydroxyethyl)-1H- pyrazole

To be printed on the label: The mixing ratio. Hair colorants can cause severe allergic reactions. Read and follow instructions. This product is not intended for use on persons under the age of 16. Temporary ‘black henna…

429-300-3

How CAS 155601-30-2 is used on this site

CAS 155601-30-2 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 155601-30-2 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 155601-30-2 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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