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1,5-Naphthalenediol

Controversial0 products
CAS
83-56-7
EC
2014874
PubChem CID
6749
Molecular Formula
C10H8O2
Molecular Weight
160.1700 g/mol

Colorant in hair dyes. May cause allergic skin reactions; use is restricted.

What does it do?

Used as a colorant in hair dyes.

Details

A synthetic dye used as a colorant in hair dyes. This substance, which gives the product brown and dark tones, is known for its allergenic properties. It can cause redness and itching in dyes applied to hair with poor resistance. Those with allergies, eczema, and pregnant women are in the risk group. It may appear on labels as 'Naphthol' or '1,5-dihydroxynaphthalene'.

Hazards

Carcinogenicⓘ
Mutagenicⓘ

Benefits

None Specified

Functions

Colorant

Restrictions

Risky During Pregnancy
Not Suitable for Infants

Where is it found?

Hair dyes

Also known as

Naphthalene-1,5-diol

Function & Use

Hair Dyeing

Regulatory note

  • EU 1223/2009 Annex IIIRestricted

Industry GHS notices (PubChem)

These are industry self-reports to ECHA, not our regulatory assessment.

  • H302(77.8%)- Harmful if swallowed
  • H317(28.8%)- May cause an allergic skin reaction
  • H319(71.9%)- Causes serious eye irritation
  • H411(59.5%)- Toxic to aquatic life with long lasting effects
PubChem CID 6749 →
The verdict isn’t ours: below is what SCCS (EU Scientific Committee on Consumer Safety), ToxValDB (EPA Toxicity Value Database) said, verbatim.

What The Sources Say

SCCS (EU Scientific Committee on Consumer Safety)12
Safety assessment

EU 1223/2009 Annex III — SCCS opinion: Request for a Re-evaluation of hair dyes listed in Annex III to Directive 76/768/EEC on Cosmetic Products

Safety assessment

EU 1223/2009 Annex III — SCCS opinion: Opinion concerning Use of Permanent Hair Dyes and Bladder Cancer - Updated 2004

Safety assessment

EU 1223/2009 Annex III — SCCS opinion: Opinion on Personal Use of Hair Dyes and Cancer Risk

Safety assessment

EU 1223/2009 Annex III — SCCS opinion: Opinion on the Use of Permanent Hair Dyes and Bladder Cancer Risk

Safety assessment

EU 1223/2009 Annex III — SCCS opinion: Assessment Strategies for Hair Dyes

+7 more records.

ToxValDB (EPA Toxicity Value Database)5
Hazard claimView source →

EPA ToxValDB skin/eye data — endpoint: Skin Sensitization, classification: SkinSens1. Caveat: this is an aggregated record; dose, species and route of exposure must be considered together.

Hazard claimView source →

EPA ToxValDB skin/eye data — endpoint: Eye Irritation, classification: Category 6.4A (Category 2A). Caveat: this is an aggregated record; dose, species and route of exposure must be considered together.

Hazard claimView source →

EPA ToxValDB skin/eye data — endpoint: eye irritation: in vivo, classification: Severe Irritation, species: rabbit, study: eye irritation, guideline: OECD Guideline 405 (Acute Eye Irritation / Corrosion) according to, year: 2010. Caveat: this is an aggregated record; dose, species and route of exposure must be considered together.

Hazard claimView source →

EPA ToxValDB skin/eye data — endpoint: skin irritation: in vivo, classification: Moderate or Mild Irritation, species: rabbit, study: skin irritation, guideline: OECD Guideline 404 (Acute Dermal Irritation / Corrosion) according to, year: 2010. Caveat: this is an aggregated record; dose, species and route of exposure must be considered together.

+1 more records.

Scientific References

  • 5-DihydroxynaphthaleneSCCS — Scientific Committee on Consumer Safety
  • 5-NaphthalenediolSCCS — Scientific Committee on Consumer Safety
  • Assessment Strategies for Hair DyesSCCS — Scientific Committee on Consumer Safety
  • EPA CompTox Chemicals Dashboard — DSSTox identifiers mapped to CAS (2021r1)US EPA, Center for Computational Toxicology and Exposure
  • EU CosIng — Cosmetic Ingredient Database full exportEuropean Commission, DG GROW
  • Memorandum on Hair Dye Substances and their Skin Sensitising PropertiesSCCS — Scientific Committee on Consumer Safety
  • Opinion concerning Use of Permanent Hair Dyes and Bladder Cancer - Updated 2004SCCS — Scientific Committee on Consumer Safety
  • Opinion on 1SCCS — Scientific Committee on Consumer Safety
  • Opinion on Personal Use of Hair Dyes and Cancer RiskSCCS — Scientific Committee on Consumer Safety
  • Opinion on the Use of Permanent Hair Dyes and Bladder Cancer RiskSCCS — Scientific Committee on Consumer Safety
  • PubChem — CID-Synonym-filtered bulk + PUG REST propertiesNCBI / National Library of Medicine
  • Request for a Re-evaluation of hair dyes listed in Annex III to Directive 76/768/EEC on Cosmetic ProductsSCCS — Scientific Committee on Consumer Safety
  • ToxValDB — genotoxicityUS EPA — ToxValDB v97
  • ToxValDB — skin/eyeUS EPA — ToxValDB v97