Skip to main content
CosIng Checker
CosIng Checker
EU cosmetic ingredients, restrictions and safety
Login
Annex II Entry 1338 07/05/2013

1-Hydroxy-2,4-diaminobenzene (2,4-Diaminophenol) and its dihydrochloride salts (2,4-Diaminophenol HCl) when used as a substance in hair dye products

1-Hydroxy-2,4-diaminobenzene (2,4-Diaminophenol) and its dihydrochloride salts (2,4-Diaminophenol HCl) when used as a substance in hair dye products is listed in Annex II as a prohibited substance for cosmetic products placed on the EU market.

Search similar Back to annex Compare
Prohibited substance— Annex II, EU Regulation 1223/2009
Entry: 1338

Chemical identity and properties

PubChem 2D chemical structure for CAS 137-09-7
CAS 137-09-7PubChem CID 8715

2,4-Diaminophenol hydrochloride

Grayish-white crystals. (NTP, 1992) — CAMEO Chemicals

IUPAC name
2,4-diaminophenol;dihydrochloride
Molecular formula
C6H10Cl2N2O
Molecular weight
197.06 g/mol
Exact mass
196.0170183 Da
Topological polar surface area
72.3 Ų
Hydrogen-bond donors
5
Hydrogen-bond acceptors
3
Covalent units
3
Defined stereocentres
0

Also known as

2,4-DIAMINOPHENOL DIHYDROCHLORIDEAcrolPhenol, 2,4-diamino-, dihydrochloride2,4-Diaminophenol HClDiamidophenol hydrochloridePhenol, 2,4-diamino-, hydrochloride (1:2)NCI-C60026T1IYY101NX
16 more reported names
RODOL 24DAPCNSC-1536RefChem:908739205-279-4Amidol2,4-Diaminophenol.2HClDianolCAS-137-09-7CCRIS 2118HSDB 4363NSC 1536EINECS 205-279-4UNII-T1IYY101NX4-Hydroxy-m-phenylenediammonium dichloride2,4-diaminophenoldihydrochloride24-Diaminophenol dihydrochloride
Open full PubChem recordPubChem annotations3D structure image
External database identifiers

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

PubChem 2D chemical structure for CAS 95-86-3
CAS 95-86-3PubChem CID 7266

2,4-Diaminophenol

On the basis of the data included in this report, the CIR Expert Panel concludes that 2,4-Diaminophenol and 2,4-Diaminophenol Dihydrochloride are safe for use in hair dyes at concentrations up to 0.2% (as the free base). 2009 RE-REVIEW - The Expert Panel noted that 2,4-Diaminophenol Dihydrochloride is now termed 2,4-Diaminophenol Hydrochloride. — Cosmetic Ingredient Review (CIR)

IUPAC name
2,4-diaminophenol
Molecular formula
C6H8N2O
Molecular weight
124.14 g/mol
Exact mass
124.063662883 Da
XLogP3
0.5
Topological polar surface area
72.3 Ų
Hydrogen-bond donors
3
Hydrogen-bond acceptors
3
Covalent units
1
Defined stereocentres
0

Also known as

Phenol, 2,4-diamino-H691WBT7OSNSC-5727RefChem:82279202-459-4NSC5727NSC 5727EINECS 202-459-4
12 more reported names
UNII-H691WBT7OSBRN 050847524-diaminophenol3-amino-4-hydroxyanilineaniline, 3-amino-4-hydroxy-XIWMTQIUUWJNRP-UHFFFAOYSA-2,4-DIAMINOPHENOL [MI]4-HYDROXY-1,3-BENZENEDIAMINEDS-2112DB-226824EN300-35023InChI=1/C6H8N2O/c7-4-1-2-6(9)5(8)3-4/h1-3,9H,7-8H2
Open full PubChem recordPubChem annotations3D structure image
External database identifiers

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

Record details

Chemical name

1-Hydroxy-2,4-diaminobenzene (2,4-Diaminophenol) and its dihydrochloride salts (2,4-Diaminophenol HCl) when used as a substance in hair dye products

Regulatory information

Regulation

(EC) 2013/344

See every entry this act set

SCCS opinions

Identified ingredients

Key data

CAS
95-86-3 -- 137-09-7
EC
202-459-4 -- 205-279-4
Annex
II
Entry number
1338

Inventory links for 1-Hydroxy-2,4-diaminobenzene (2,4-Diaminophenol) and its dihydrochloride salts (2,4-Diaminophenol HCl) when used as a substance in hair dye products

Direct matches are limited for this record, so nearby entries from Annex II are shown as well.

What Annex II means for 1-Hydroxy-2,4-diaminobenzene (2,4-Diaminophenol) and its dihydrochloride salts (2,4-Diaminophenol HCl) when used as a substance in hair dye products

1-Hydroxy-2,4-diaminobenzene (2,4-Diaminophenol) and its dihydrochloride salts (2,4-Diaminophenol HCl) when used as a substance in hair dye products is listed as a prohibited substance under Annex II of EU Cosmetics Regulation 1223/2009 and must not be intentionally added. Article 17 separately addresses unintended small quantities that are technically unavoidable under good manufacturing practice and compatible with the Article 3 safety requirement.

Formulators must screen their ingredients and raw materials to ensure none contain this substance. Suppliers should provide documentation confirming absence when requested.

This record is linked to 2 CosIng inventory ingredients for name and identifier cross-reference. The page also surfaces 12 related annex records with overlapping identifiers, annex logic or naming patterns.

Compliance checklist

  • Verify this substance is absent from all raw materials and finished formulations.
  • Request absence confirmation or CoA from raw material suppliers.
  • Document the screening result in the Product Information File (PIF).

Frequently asked questions

Yes. 1-Hydroxy-2,4-diaminobenzene (2,4-Diaminophenol) and its dihydrochloride salts (2,4-Diaminophenol HCl) when used as a substance in hair dye products is listed in Annex II of EU Cosmetics Regulation 1223/2009 and is prohibited as an intentionally added cosmetic ingredient. Article 17 provides a narrow exception for unintended small quantities that are technically unavoidable under good manufacturing practice, provided the product remains safe under Article 3.

CAS 95-86-3 -- 137-09-7 is the unique numerical identifier assigned to 1-Hydroxy-2,4-diaminobenzene (2,4-Diaminophenol) and its dihydrochloride salts (2,4-Diaminophenol HCl) when used as a substance in hair dye products by the Chemical Abstracts Service. In cosmetic compliance work, the CAS number is used to cross-reference the substance across regulatory databases, raw material specifications and safety assessment reports. Multiple EU annex entries may share the same CAS number if the same substance appears under different conditions or in different annexes.

Use the INCI Checker tool on this site to paste your full ingredient list (INCI) and scan it against all Annex II–VI entries. The tool highlights any ingredients that match restricted, prohibited or allergen-flagged records. This is useful for rapid compliance screening of finished product formulas or raw material declarations.
Open INCI Checker

Source note for Annex II record 1-Hydroxy-2,4-diaminobenzene (2,4-Diaminophenol) and its dihydrochloride salts (2,4-Diaminophenol HCl) when used as a substance in hair dye products

This page summarizes one Annex II record for 1-Hydroxy-2,4-diaminobenzene (2,4-Diaminophenol) and its dihydrochloride salts (2,4-Diaminophenol HCl) when used as a substance in hair dye products from public European Commission cosmetic materials and adds linked inventory or identifier matches when available.

Use this record page to review Annex II conditions for 1-Hydroxy-2,4-diaminobenzene (2,4-Diaminophenol) and its dihydrochloride salts (2,4-Diaminophenol HCl) when used as a substance in hair dye products, but confirm any final regulatory decision against the current official annex wording and source files.

View sourcesView updates

Tools & next steps

Check your formula

Paste a full INCI list to detect 1-Hydroxy-2,4-diaminobenzene (2,4-Diaminophenol) and its dihydrochloride salts (2,4-Diaminophenol HCl) when used as a substance in hair dye products and other flagged EU annex records in one pass.

INCI Checker

Compare entries

Compare 1-Hydroxy-2,4-diaminobenzene (2,4-Diaminophenol) and its dihydrochloride salts (2,4-Diaminophenol HCl) when used as a substance in hair dye products side by side with another annex record to review differences in restrictions, concentrations and annex placement.

Compare

Browse the annex

See all records in Annex II and compare regulatory conditions across substances in this annex.

Open Annex II