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InventoryRef 4152711/12/2020

BASIC ORANGE 31

2-((4-Aminophenyl)azo)-1,3-dimethyl-1H-imidazolium chloride

BASIC ORANGE 31 is linked to 1 EU annex record on this page. Inventory note: III/276.

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Regulatory evidence by market

This matrix separates verified ingredient rules from sources that are mapped but not yet imported. No imported rule does not mean the ingredient is permitted.

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MarketEvidence statusRecordsSource language
European UnionEvidence linked
Restricted entry found
Open this evidence		1English and EU languages
Great BritainEvidence linked
Restricted
Open this evidence		1English
CanadaSource mapped
Official source mapped; ingredient rule not imported
0English and French
New ZealandEvidence linked
Restricted
Open this evidence		1English
ASEANEvidence linked
Restricted
Open this evidence		1English and national languages
ChinaSource mapped
Official source mapped; ingredient rule not imported
0Chinese with selected English material
JapanSource mapped
Official source mapped; ingredient rule not imported
0Japanese; official English translation available
South KoreaEvidence linked
Restricted
Open this evidence		1Korean with some English names
United StatesSource mapped
Official source mapped; ingredient rule not imported
0English
AustraliaSource mapped
Official source mapped; ingredient rule not imported
0English
BrazilSource mapped
Official source mapped; ingredient rule not imported
0Portuguese with INCI crosswalks
IndiaEvidence linked
Restricted
Open this evidence		1English and Hindi
Saudi ArabiaEvidence linked
Restricted
Open this evidence		1Arabic and English

Chemical identity and properties

PubChem 2D chemical structure for CAS 97404-02-9
CAS 97404-02-9PubChem CID 9881454

Basic Orange 31

IUPAC name
4-[(1,3-dimethylimidazol-1-ium-2-yl)diazenyl]aniline chloride
Molecular formula
C11H14ClN5
Molecular weight
251.71 g/mol
Exact mass
251.0937732 Da
Topological polar surface area
59.6 Ų
Hydrogen-bond donors
1
Hydrogen-bond acceptors
4
Covalent units
2
Defined stereocentres
0

Also known as

2-[(4-AMINOPHENYL)AZO]-1,3-DIMETHYL-1H-IMIDAZOLIUM CHLORIDEUNII-O1JIQ710E2O1JIQ710E2COLOREX BO31EINECS 306-764-42-((4-Aminophenyl)azo)-1,3-dimethyl-1H-imidazolium chlorideVIBRACOLOR FLAME ORANGE1H-IMIDAZOLIUM, 2-(2-(4-AMINOPHENYL)DIAZENYL)-1,3-DIMETHYL-, CHLORIDE (1:1)
16 more reported names
1H-Imidazolium, 2-[2-(4-aminophenyl)diazenyl]-1,3-dimethyl-, chloride (1:1)RefChem:116619BASIC ORANGE 31 [INCI]Flame Orange4-[(1,3-dimethylimidazol-1-ium-2-yl)diazenyl]aniline;chloride2-[(4-Aminophenyl)azo]-1,3-dimethyl-1H-imidazoliumchlorideFlameOrangelaranja basico 31naranja basica 31orange de base 31arancio di base 31MIP Orange 3100COLIPA B118MSK59002-((4-Aminophenyl)diazenyl)-1,3-dimethyl-1H-imidazol-3-ium chlorideAS-94362
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.

Inventory details for BASIC ORANGE 31

INCI name

BASIC ORANGE 31

Description

2-((4-Aminophenyl)azo)-1,3-dimethyl-1H-imidazolium chloride

Record provenance

Inventory reference
41527
Imported identity
BASIC ORANGE 31
Source update
11/12/2020
European Commission CosIng source notes
Annex III Restriction reference
Entry 276

BASIC ORANGE 31

CAS: 97404-02-9
EC: 306-764-4

Key data

CAS
97404-02-9
EC
306-764-4
Restriction
III/276
Function
HAIR DYEING
Imparting color to hair. Hair dyeing preparations may be temporary, semi-permanent, or permanent, depending on the length of time the colorant remains on the hair.

Official EU ingredient-name evidence

The ingredient name exactly matches the official 2025 EU glossary of common ingredient names.

#3087 · BASIC ORANGE 31

Ingredients with overlapping formulation functions

BASIC GREEN 1HAIR DYEING
BASIC GREEN 4HAIR DYEING
BASIC ORANGE 1HAIR DYEING
BASIC ORANGE 2HAIR DYEING
BASIC ORANGE 69HAIR DYEING
BASIC RED 1HAIR DYEING
BASIC RED 118HAIR DYEING
BASIC RED 1:1HAIR DYEING

Additional official and scientific sources

11 external databases to check this identity in

Each link searches that source for this identity. What each source is, and its legal weight

ECHA CHEM / Information on chemicalsPubChem PUG RESTEU Safety Gate cosmetic product alertsECHA CHEMUS EPA CompToxCosmetic Ingredient Review safety assessmentsFDA Global Substance Registration SystemILO/WHO International Chemical Safety CardsJapan NITE-CHRIPNIOSH Pocket Guide to Chemical HazardsOECD eChemPortal

How BASIC ORANGE 31 appears in the CosIng inventory

The CosIng inventory lists BASIC ORANGE 31 as a cosmetic ingredient and this page links it to 1 annex record. The inventory entry captures names and identifiers, while the annex record shows where the substance is prohibited, restricted or positively listed in EU cosmetics law.

BASIC ORANGE 31 is also tagged with 1 cosmetic function in the official data. Function labels describe intended use, but they do not replace regulatory review of linked annex records before formulation or labelling work.

Frequently asked questions

BASIC ORANGE 31 appears in the EU CosIng inventory and has linked annex records. Check the annex records above for applicable restrictions, concentration limits and conditions of use. Annex II listing means prohibited; Annex III means restricted; Annexes IV, V and VI mean permitted under specified conditions.

The restriction field for BASIC ORANGE 31 reads: "III/276". This is the restriction note recorded in the CosIng inventory for this ingredient. For authoritative conditions and limits, always refer to the linked annex entries above.

According to the EU CosIng inventory, BASIC ORANGE 31 carries the following function designation(s):

CAS 97404-02-9 may appear across multiple EU annex records. Viewing the CAS lookup page shows all Annex II–VI entries sharing this identifier, which is useful for identifying cross-annex regulatory status of the same chemical substance.
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Source note for BASIC ORANGE 31

This page combines the CosIng inventory entry for BASIC ORANGE 31 with 1 linked Annex II–VI record from the local dataset built from public European Commission cosmetic ingredient materials.

Use this inventory page to research BASIC ORANGE 31 and compare linked records, but verify restrictions and legal status against the current official source text and law before making regulatory decisions.

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