Ingredient Dictionary

SOLVENT RED 24

Sudan IV is a bis(azo) compound that is 2-naphthol substituted at position 1 by a {2-methyl-4-[(2-methylphenyl)diazenyl]phenyl}diazenyl group.

Definition

Sudan IV is a bis(azo) compound that is 2-naphthol substituted at position 1 by a {2-methyl-4-[(2-methylphenyl)diazenyl]phenyl}diazenyl group. A fat-soluble dye predominantly used for demonstrating triglycerides in frozen sections, but which may also stain some protein bound lipids in paraffin sections. It has a role as a carcinogenic agent, a fluorochrome and a histological dye. It is a member of azobenzenes, a member of naphthols and a bis(azo) compound. It is functionally related to a 2-naphthol.

Source: PubChem

US FDA substance register · UNII I35E9QU96C · registered name SOLVENT RED 24 · single chemical substance

Source: US FDA Unique Ingredient Identifier (UNII)

Cosmetic roles

Adds colourCOLORANT

Safety & regulatory references

Banned: Argentina · ASEAN · Brazil · Canada · China · European Union · South Korea · United Kingdom
Restricted: Japan

Source: ASEAN Cosmetic Directive · EU Cosmetics Regulation · Health Canada Cosmetic Ingredient Hotlist · MFDS (Korea) cosmetic regulatory information · UK cosmetics regulations (OPSS)

Not classified under Korea’s toxic-substance GHS list · existing chemical substance

Source: Korea toxic substances GHS register (NIER)

EU Cosmetics Regulation, Annex II (prohibited substances), entry 379

Source: EU prohibited substances (Annex II)

Health Canada Cosmetic Ingredient Hotlist · prohibited in cosmetics

Source: Health Canada Cosmetic Ingredient Hotlist

Restriction II/379

Source: EU CosIng ingredient list

More data — names, identifiers, properties, test records, literature

Names & identifiers

SOLVENT RED 24INCI솔벤트적색24호Korean label name (MFDS standard)2-Naphthalenol, 1-[[2-methyl-4-[(2-methylphenyl)azo]phenyl]azo]-Synonym

CAS No.chemical registry number: 85-83-6
EC No.EU chemical inventory number: 201-635-8
DTXSIDUS EPA chemical ID: DTXSID8041743
DTXCIDUS EPA compound ID: DTXCID30809644

IUPAC: 1-({2-Methyl-4-[(2-methylphenyl)diazenyl]phenyl}diazenyl)naphthalen-2-ol
Molecular formula: C24H20N4O
Molecular weight: 380.451 g/mol

Measured properties

Appearance: solid
pH: 9.94 (1 % w/v, 26℃, OECD Guideline 122 (Determination of pH, Acidity and Alkalinity))
Melting/freezing point: 183.5 ℃
Initial boiling point and range: &amp, gt, 238 ℃
Flash point: &amp, gt, 289 ℃
Flammability (solid, gas): not flammable
Vapour pressure: 0 ㎩ (25℃)
Water solubility: 0.023 ㎎/ℓ (25℃)
Vapour density: 1.331 g/㎤
n-Octanol/water partition coefficient (Kow): 6.66 (log Pow)

Values measured on the substance itself. The KOSHA data are a reference for writing and reviewing safety data sheets, not a specification for a commercial raw material.

Source: KOSHA safety data sheets (Korea)

What products actually use it for

What the 9 products reported to the US EPA with this ingredient use it for. Products outside cosmetics are included, so the top few rows are its main uses.

Dye9

Source: US EPA CompTox dashboard

Irritation and sensitisation studies

2 skin studies and 1 eye studies are on record.

Classed as highly irritating2Classed as moderate1

The study conclusions largely agree (67%). These tests are on the raw material itself; irritation at the amount in a finished product is a different question.

See all 3 studies

High Frequency of Sensitization
skin sensitisation: in vivo (non-LLNA) · Screening · equivalent or similar to other guideline: Patch test
Moderate or Mild Irritation
skin irritation: in vivo · Screening · OECD Guideline 404 (Acute Dermal Irritation / Corrosion) according to
Studies Indicate No Significant Irritation
eye irritation: in vitro / ex vivo · Screening · other guideline: OECD Guideline 492 (Reconstructed Human Cornea-like Epithelium (RhCE) Test Method for Identifying Chemicals Not Requiring Classification and Labelling for Eye Irritation or Serious Eye Damage) according to